To see the other types of publications on this topic, follow the link: Red-Ox potential.
Journal articles on the topic 'Red-Ox potential'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Red-Ox potential.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Chernomorskii, A. I. "The Correlation Between the Electronegativities and the Standard Potentials." Journal of The Electrochemical Society 168, no. 11 (2021): 116514. http://dx.doi.org/10.1149/1945-7111/ac3a26.
Full textAbstract:
The linear correlations are analyzed between the empirical electronegativities χ a of metals and non-metals and their standard potentials E o . The correlation intersection corresponds to the transfer from metals to non-metals, characterized by the intermediate electronegativity χ a,interm and the standard potential E o ∼+ 0.5 V SHE which is close to Billiter potential +0.475 V SHE. The electronegativity χ a,interm and E o ∼ +0.5 V SHE would correspond to some hypothetical substance (neither metal nor non-metal) without own chemical actiity. This would be due to the intermediate non-specific (definite coulomb) bond of its outer electrons. This bond is not enough unstable (as metallic bonds) for breaking and not enough stable (as non-metallic bonds) for accepting electrons. Spontaneous half-reactions-interactions of Red - and Ox - forms on electrodes are due to the break Red + H2O → Ox + ne interm and formation Ox + ne interm + H2O → Red of specific (chemical) electron bonds with Ox-forms, where ne interm are electrons without specific bond with Ox-forms. The instant division of electrons ne interm, ions and polarized water molecules of formed intermediate complexes leads to the appearance of double-electric layers on electrodes.
2
Kovalenko, Irina, and Pavel Kolesnichenko. "EXPERIMENTAL RATIONALE FOR THE USE OF FLUIDS WITH DIFFERENT REDOX POTENTIAL AS A BASIS FOR INFUSION THERAPY." Research Results in Pharmacology 3, no. (2) (2017): 29–37. https://doi.org/10.18413/2313-8971-2017-3-2-29-37.
Full textAbstract:
Introduction: The hypothesis is that a change in the redox potential (Red-Ox) of infusion solutions can increase their pharmacological efficacy. Objectives: To study the parameters of redox potential (ORP or Red-Ox) and pH of infusion solutions. To identify the general biological properties of ionized liquids with different ORP when administered by different methods to experimental animals and when applied to the wound surface. To study the effects of infusion therapy with solutions based on ionized fluids with various ORP in anaphylactic shock, bacterial sepsis, alcoholic hepatitis, dehydration, and skin injuries. Materials and methods: Determination of practical osmolarity of ionized liquids with different ORP was carried out by the cryoscopic method with the use of the Beckmann thermometer. The study used experimental models of anaphylactic shock, bacterial sepsis, alcoholic hepatitis, dehydration and cutaneous injuries in rats. The study of the general biological properties of ionized liquids with different ORP was carried out in 4 groups of experiments. In the first group: experiments to investigate the effect of liquids with different ORP on the action of ophthalmic drugs and eye tissue – on 75 rabbits; in the 2-nd: experiments on the level of glucose in the blood; in the 3-rd: the study of reactions of the cardiovascular system to intravenous administration of ionized liquids with various ORP in the maximum permissible volumes; in the 4-th: the research of regenerative abilities of liquids with various ORP with a cutaneous injury. Results: It was found that the ORP of infusion solutions is higher than the potential of liquid media by 100-400 mV. The cryoscopic method established the possibility of preparing isoosmolar infusion solutions with various Red-Ox potentials. In the models of anaphylactic shock and bacterial sepsis, the expediency of changing the Red-Ox potential of body fluids is shown. Addition of ionized liquids with different ORP to a 0.1% solution of adrenaline hydrochloride in a ratio of 1:1 leads to prolongation of the pharmacological effects of the drug. After instilling the ionized liquid with positive ORP in the conjunctiva a weak local anesthetic effect is observed. Electrocardiography of the experimental rabbits showed that a decrease in the Red-Ox potential of the isotonic sodium chloride solution increases its therapeutic range, reducing the load on the right atrium and ventricles. Regenerative efficiency in the treatment of wound surfaces was noted when using ionized liquid with ORP = minus 250 mV. Conclusion: The use of ionized fluids with various ORP as the basis of infusion solutions for anaphylactic shock, bacterial sepsis, alcoholic hepatitis, and dehydration has shown high efficiency. At the same time, the issues of compatibility of ionized liquids with different ORP with various pharmacological preparations remain unresolved, the issues of pharmaceutical stability of liquids with negative Red-Ox potential, etc. are not solved either, which indicates the prospects of research in this direction.
3
Chernomorskii, Alexandr I. "Diagram for the Electrochemical Stability of Water." ECS Meeting Abstracts MA2023-01, no. 44 (2023): 2447. http://dx.doi.org/10.1149/ma2023-01442447mtgabs.
Full textAbstract:
According to the electrochemical stability diagram of water (Fig. 1), Ox/Red pairs displace hydrogen and oxygen respectively, when equilibrium potentials E Ox/Red < E H+/H2 (line a ) and E Ox/Red > E O2/OH- (line b ). However, if this is theoretically possible, the fact is that only pairs with E Ox/Red > ~ +0.5 V SHE ( E o I2/I- = + 0.535 V SHE; E o NiO2/Ni(OH)2,OH- = + 0.49 V SHE) displace oxygen from alkaline solutions and only pairs with E Ox/Red < ~ +0.5 V SHE ( E o Cu/Cu2+ = +0.34 V SHE; E o Co/Co3+ = +0.4 V SHE) can displace hydrogen from acid solutions. There will be no displacement of oxygen by ions Cu2+ (Ox-form) and hydrogen by ions I- (Red-form) at the appropriate pH (Fig.1) [1,2]. The reason for this is that Red-forms (I-ions) with E Red/Ox > ~+0.5 V SHE and Ox-forms (Cu2+, Co3+ ions) with E Red/Ox < ~+0.5 V SHE is already thermodynamically stable in solutions, their transitions to conjugated forms (I2, Cu) are not spontaneous. With the theoretical possibility of H2 displacement, ions I-will form acids (HI) with H+ ions. With the theoretical possibility of O2 displacement, ions Cu2+, Co3+ will form hydroxides (Cu(OH)2) with OH- ions. These reactions are more thermodynamically probable. Accordingly, electrodes displace either hydrogen or oxygen from water. Between pairs with low oxidizing and reducing activities, there should be a pair of zero activity, in which Ox + ne and Red-forms are chemically equilibrium (line c , Fig.1) [1-3]. Its average potential is E Red/Ox ~ +0.44 V SHE between E o I2/I- = + 0.535 V SHE and E o Cu/Cu2+ = +0.34 V SHE and E Red/Ox ~ +0.47 V SHE between nearest E o NiO2/Ni(OH)2,OH- = +0.49 V SHE and E o Ru/Ru3+ = +0.45 V SHE determined opposite activities [1,2]. The intersection of line c with lines a (pH = -8; point d ) and b (pH=12.8; point e) should also correspond to zero activity of H+/H2 - and O2/OH- - electrodes (Fig.1). The difference ΔpH =12.8 – (-8) = 20.8 determines emf of H+/H2//O2/OH- element (20.8 x 0.0 59 = 1.227 V) [1]. The instability of metal ions reflects itself in the decomposition of hydroxides 2CuOH→ Cu2O + H2O; 2AuOH → Au2O +H2O. Unstable metal ions (Cu+, Te4+, Ag+, Au+) can polarize hydroxyl ions without the formation of the pair OH-/O2[2]. Indeed, the boundary at E Red/Ox ~+0.47 V SHE separates stable and unstable hydroxides (Table). Me/Men+ E o, V SHE Hydroxide/Oxide Pb/Pb2+ -0.126 Pb(OH)2 Cu/Cu 2+ +0.34 Cu(OH)2 Co/Co 3+ +0.4 (+0.46) Co(OH)3 Ru/Ru 2+ +0.45 Ru(OH)2 Cu/Cu+ +0.52 Cu2O Te/Te 4+ +0.568 TeO2 Hg/Hg2 2+ +0.789 Hg2O Ag/Ag+ +0.799 Ag2O Absolute values |-E H+/H2 | = |+E O2/OH- | = 1.227 V/ 2 = ~ 613.6 mV (10.4 x 59 mV) are equal at pH = 10.4 (line f , Fig.1), where 1.227 V is the distance between lines a and b (emf H2/H+//OH-/O2 element). Line f divides the horizontal distances (as g - i ) from pH = 0 to pH = 14 (14 x 59 mV= 826 mV) into parts 1227 mV / 2 = 613.6 mV ( g - h ) and 212.4 mV (3.6 pH x 59 mV; h - i ). Their ratio is 613.6 mV / 212.4 mV = ~ 2.89. Thus, presented 613.6 mV = (212.4 mV + 0.89 x 212.4 mV) + 212.4 mV = = 401.2 mV + 212.4 mV = 2.89 x 212.4 mV = =2.89 (ψ O2/OH-, pH=14 + ψ O2/OH-,pH=10.4) where ψ O2/OH-, pH=14 + ψ O2/OH-,pH=10.4 are the sum of external potential drops (not Galvani potentials) arising in half-reactions between oppositely charged particles in double-electrical layers on electrodes. Both sides are equal to 212.4 mV. Therefore, dividing 212.4 mV (left) / 2.89 = 73.5 mV should give the smallest actual component ψ O2/OH-,pH=14of equal 212.4 mV (right). Then, its second component ψ O2/OH-,pH=10.4 is 401.2 mV (left) / 2.89 =138.8 mV or 212.4 mV - 73.5 mV = 138.9 mV. Close ψ O2/OH-, pH=14 (14 - 12.8) x 59 mV = 70.8 mV and ψ O2/OH-, pH=10.4 - (12.8 - 10.4) x 59 mV =141.6 mV calculated relative to pH=12.8 (point e , Fig.1) [1]. The potential of pairs of zero activity (line c , Fig.1) is calculated as E O2/OH-,pH=10.4 - ψ O2/OH-,pH=10.4 = 613.6 mV SHE - 138.8 mV = + 474.8 mV SHE. The potential drops ψ H +/H2,pH=0 = - 474.5 mV; ψ O2/OH-,pH=0 = + 752.4 mV and ψ H +/H2= ψ O2/OH- at pH = 2.4 are calculated (Fig.1). Reference 1.A.I.Chernomorskii, Zh. Fiz. Khim., 51,924 (1977). 2.A.I.Chernomorskii, Dokl. Akad.Nauk Uzb.SSR, 3,37(1989). 3.A.I.Chernomorskii, Journal of The Electrochemical Society, 2021,168,116514. Figure 1
4
Petkovska, Sofija, and Rubin Gulaboski. "Diffusional Electrochemical Catalytic (EC’) Mechanism Featuring Chemical Reversibility of Regenerative Reaction-Theoretical Analysis in Cyclic Voltammetry." Croatica chemica acta 92, no. 4 (2020): 495–502. http://dx.doi.org/10.5562/cca3607.
Full textAbstract:
We consider theoretically a specific electrochemical-catalytic mechanism associated with reversible regenerative chemical reaction, under conditions of cyclic staircase voltammetry (CSV). We suppose scenario in which two electrochemically inactive substrates “S” and “Y”, together with initial electrochemically active reactant Ox are present in voltammetric cell from the beginning of the experiment. Substrate “S” selectively reacts with initial electroactive reactant Ox and creates electroactive “product” Red (+ Y) in a reversible chemical fashion. The initial chemical equilibrium determines the amounts of Ox and Red available for electrode transformation at the beginning of the electrochemical experiment. Under conditions of applied potential, the electrode reaction Ox(aq) + ne– ⇋ Red(aq) occurs, producing flow of electric current. Under such circumstances, the chemical reaction coupled to the electrochemical step causes a regeneration of initial electroactive species during the time-frame of current-measuring segment in CSV. The features of cyclic voltammograms get significantly affected by the kinetics and thermodynamics of reversible regenerative reaction. We elaborate several aspects of this specific electrode mechanism, and we focus on the role of parameters related to chemical step to the features of calculated voltammograms. While we provide a specific set of results of this particular mechanism, we propose methods to get access to relevant kinetic and thermodynamic parameters relevant to regenerative chemical reaction. The results elaborated in this work can be valuable in evaluating kinetics of many drug-drug interactions, but they can be relevant to study interactions of many enzyme-substrate systems, as well.
5
Gonzalez-Horta, Eddy E., Juan F. Burgueno, María J. Leiva, et al. "Oxidized Low-Density Lipoprotein Induces Reactive Oxygen Species-Dependent Proliferation of Intestinal Epithelial Cells." Pharmaceuticals 17, no. 11 (2024): 1466. http://dx.doi.org/10.3390/ph17111466.
Full textAbstract:
Background/Objectives: Oxidized low-density lipoprotein (ox-LDL) is a proinflammatory particle associated with various diseases and affects cell proliferation and viability in multiple cell types. However, its impact on intestinal epithelial cells remains underexplored. This study investigates the effect of ox-LDL on colonic epithelial cell proliferation and viability, as well as the underlying mechanisms involved. Methods: The expression levels of ox-LDL receptors in human colonoids were analyzed at baseline and in response to proinflammatory signals by qRT-PCR. The effect of ox-LDL on organoid proliferation was analyzed using morphometric measurements, viability assays, and the incorporation of a thymidine analog into DNA. The generation of reactive oxygen species (ROS) was determined by Amplex Red assays. Additionally, ox-LDL-induced ROS-dependent organoid proliferation was studied by exposing colonoids to an antioxidant or ROS inhibitors. Results: Colonic epithelial cells express ox-LDL receptors. Ox-LDL significantly induces the proliferation of colonic epithelial cells, which are dependent on ROS generation. Notably, ROS scavengers and NADPH inhibitors reduced ox-LDL-induced proliferation, highlighting the crucial role of oxidative stress in this process. Conclusions: This study demonstrates for the first time that ox-LDL stimulates CEC proliferation mediated by ROS production and validates that the colonic organoid model enables the analysis of potential pharmacological strategies for intestinal diseases characterized by oxidative stress and inflammation.
6
Käärik, Maike, Mati Arulepp, and Jaan Leis. "Partial Oxidation to Extend the Lifetime of Nanoporous Carbon in an Ultracapacitor with Li2SO4 Electrolyte." Molecules 28, no. 7 (2023): 2944. http://dx.doi.org/10.3390/molecules28072944.
Full textAbstract:
A TiC-derived carbon (CDC) and its partially oxidized derivative (ox-red-CDC), oxidized by a modified Hummers method, were studied as promising electrode materials for electrochemical energy storage. To evaluate the electrochemical properties of the carbon materials, cyclic voltammetry, galvanostatic cycling, and electrochemical impedance spectroscopy measurements were performed in 1 M Li2SO4 using 2- and 3-electrode cells. A partially oxidized surface was shown to improve the capacitance and electrochemical stability of a nanoporous CDC at positive potential values. The respective anodic capacitance of 80 F cm−3 reveals a 15% improvement over the non-oxidized CDC. At negative potential values, the capacitance of two carbon materials is almost equal, 97 vs. 93 F cm−3, for the non-oxidized and partially oxidized CDC materials, respectively. An asymmetric 2-electrode ultracapacitor containing ox-red-CDC as the anode and pristine CDC as the cathode demonstrated an excellent cycle life. The temporary repolarization of the 2-electrode cell after thousands of charge–discharge cycles increased the capacitance and improved the cycling characteristics, likely due to regeneration and cleaning of the electrode surface.
7
Shevnin, V. A. "IDENTIFICATION OF SELF-POTENTIAL ANOMALIES OF DIFFUSION-ADSORPTION ORIGIN." Moscow University Bulletin. Series 4. Geology, no. 2 (April 28, 2018): 93–98. http://dx.doi.org/10.33623/0579-9406-2018-2-93-98.
Full textAbstract:
Diffusion and adsorption (DA) potentials are frequently the sources of self-potential anomalies, but they not arouse such practical interest as anomalies of red-ox and filtration origin. DA anomalies can be found everywhere and geophysicists sometimes make mistakes considering DA anomalies as examples of filtration anomalies. Identification of DA anomalies is based on correlation of SP and apparent resistivity values along the same profiles. At MSU students geophysical practice in Kaluga region we obtained profiles with SP and resistivity anomalies with good correlation between them. That fact allows consider such SP anomalies as a result of DA processes.
8
Mirza, Zeenat, Dalal A. Al-Saedi, Salma Saddeek, Sanaa Almowallad, Rehab F. AlMassabi, and Etimad Huwait. "Atheroprotective Effect of Fucoidan in THP 1 Macrophages by Potential Upregulation of ABCA1." Biomedicines 11, no. 11 (2023): 2929. http://dx.doi.org/10.3390/biomedicines11112929.
Full textAbstract:
Targeting foam cells reduces the risk and pathophysiology of atherosclerosis, of which they are one of its early hallmarks. The precise mechanism of action of fucoidan, a potential anti-atherogenic drug, is still unknown. Our objective was to assess the ability of fucoidan to regulate expression of ATP-binding cassette transporter A1 (ABCA1) in ox-LDL-induced THP-1 macrophages. Molecular docking was used to predict how fucoidan interacts with anti-foam cell markers, and further in vitro experiments were performed to evaluate the protective effect of fucoidan on modulating uptake and efflux of lipids. THP-1 macrophages were protected by 50 µg/mL of fucoidan and were then induced to form foam cells with 25 µg/mL of ox-LDL. Expression levels were assessed using RT-qPCR, and an Oil Red O stain was used to observe lipid accumulation in THP-1 macrophages. In addition, ABCA1 protein was examined by Western blot, and cellular cholesterol efflux was determined using fluorescently labeled cholesterol. Under a light microscope, decreased lipid accumulation in ox-LDL-induced-THP-1 macrophages pre-treated with fucoidan showed a significant effect, although it did not affect the expression of scavenger receptors (SR-AI and CD36). It is interesting to note that fucoidan dramatically increased the gene and protein expression of ABCA1, perhaps via the liver X receptor-α (LXR-α). Moreover, fucoidan’s ability to increase and control the efflux of cholesterol from ox-LDL-induced THP-1 macrophages revealed how it may alter ABCA1’s conformation and have a major effect on how it interacts with apolipoprotein A (ApoA1). In vitro results support a rationale for predicting fucoidan and its interaction with its receptor targets’ predicted data, hence validating its anti-atherogenic properties and suggesting that fucoidan could be promising as an atheroprotective.
9
Liang, Caihong, Xiaochen Wang, Jianping Hu та ін. "PTPRO Promotes Oxidized Low-Density Lipoprotein Induced Oxidative Stress and Cell Apoptosis through Toll-Like Receptor 4/Nuclear Factor κB Pathway". Cellular Physiology and Biochemistry 42, № 2 (2017): 495–505. http://dx.doi.org/10.1159/000477596.
Full textAbstract:
Background/Aims: Critical roles of phosphatase receptor type O (PTPRO) and toll-like receptor 4 (TLR4) have been implicated in inflammation. However, little is known about their functional effects on atherosclerosis (AS). We aim to study their potential function in AS. Methods: An oxidized low-density lipoprotein (ox-LDL) induced AS model constructed with PTPRO over-expressing RAW264.7 cells and PTPRO knockout macrophages. Cell apoptosis was assayed by flow cytometry and fatty accumulation was evaluated by oil red staining. The production of ROS (reactive oxygen species), SOD (superoxide dismutase), MDA (malondialdehyde), TC (Triglyceride), and TG (total cholesterol) was evaluated. Western blot was performed to detect the expression of CD36, TLR4 and nuclear factor kB (NF-κB). Results: PTPRO expression was promoted in a dose-dependent and time-dependent manner following ox-LDL challenging. In PTPRO-over-expressing cells, CD36 expression and the level of oil-red staining, TC and TG were increased; ROS production, MDA and level of cell apoptosis were improved, but SOD was reduced. However, in PTPRO knockout cells opposite results were found. TLR4 and NF-κB/p65 phosphorylation was significantly enhanced in PTPRO over-expressing cells, while significantly down-regulated in PTPRO knockout cells. Conclusion: PTPRO plays ital roles in AS via promoting ox-LDL induced oxidative stress and cell apoptosis through TLR4/NF-κB pathway.
10
Zhang, Bu-Chun, Cong-Wei Zhang, Cheng Wang, De-Feng Pan, Tong-Da Xu, and Dong-Ye Li. "Luteolin Attenuates Foam Cell Formation and Apoptosis in Ox-LDL-Stimulated Macrophages by Enhancing Autophagy." Cellular Physiology and Biochemistry 39, no. 5 (2016): 2065–76. http://dx.doi.org/10.1159/000447902.
Full textAbstract:
Background: Our previous studies demonstrated that luteolin, which is rich in flavones, has various biological properties and can exert anti-oxidant, anti-inflammatory and anti-apoptotic activities. However, its effect on ox-LDL-induced macrophage lipid accumulation and apoptosis has not been revealed. Aims: This study aimed to explore the role of luteolin in ox-LDL-induced macrophage-derived foam cell formation and apoptosis and to delineate the underlying mechanism. Methods: Murine RAW264.7 cells were stimulated with oxidized low-density lipoprotein (ox-LDL) (50 µg/ml) for 24 h and then pretreated with 25 µM luteolin for another 24 h. The effects of luteolin on lipid accumulation in RAW264.7 cells induced by ox-LDL were assayed using Oil red O staining and high performance liquid chromatography (HPLC). Apoptosis was confirmed by acridine orange/ethidium bromide (AO/EB) staining, flow cytometric analysis and the TUNEL assay. Immunofluorescence, Western blot and monodansylcadaverine (MDC) staining analyses were then used to further investigate the molecular mechanisms by which luteolin protects macrophages from ox-LDL-induced foam cell formation and apoptosis. 3-Methyladenine (3-MA), an autophagy inhibitor, was used as a positive control. Results: Treatment with 25 µM luteolin not only significantly attenuated ox-LDL-induced macrophage lipid accumulation but also decreased the apoptotic rate of RAW264.7 cells, the number of TUNEL-positive macrophages and the expression of Bax, Bak, cleaved caspase-9 and cleaved caspase-3. In addition, luteolin pretreatment significantly increased autophagosome formation and Beclin-1 activity, thus increasing the ratio of LC3-II/LC3-I. Moreover, these effects were abolished by 3-MA. Conclusions: Taken together, these results highlight that luteolin treatment attenuates foam cell formation and macrophage apoptosis by promoting autophagy and provide new insights into the molecular mechanism of luteolin and its therapeutic potential in the treatment of atherosclerosis.
11
Zeden, Merve S., Laura A. Gallagher, Emilio Bueno та ін. "Metabolic reprogramming and altered cell envelope characteristics in a pentose phosphate pathway mutant increases MRSA resistance to β-lactam antibiotics". PLOS Pathogens 19, № 7 (2023): e1011536. http://dx.doi.org/10.1371/journal.ppat.1011536.
Full textAbstract:
Central metabolic pathways control virulence and antibiotic resistance, and constitute potential targets for antibacterial drugs. In Staphylococcus aureus the role of the pentose phosphate pathway (PPP) remains largely unexplored. Mutation of the 6-phosphogluconolactonase gene pgl, which encodes the only non-essential enzyme in the oxidative phase of the PPP, significantly increased MRSA resistance to β-lactam antibiotics, particularly in chemically defined media with physiologically-relevant concentrations of glucose, and reduced oxacillin (OX)-induced lysis. Expression of the methicillin-resistance penicillin binding protein 2a and peptidoglycan architecture were unaffected. Carbon tracing and metabolomics revealed extensive metabolic reprogramming in the pgl mutant including increased flux to glycolysis, the TCA cycle, and several cell envelope precursors, which was consistent with increased β-lactam resistance. Morphologically, pgl mutant cells were smaller than wild-type with a thicker cell wall and ruffled surface when grown in OX. The pgl mutation reduced resistance to Congo Red, sulfamethoxazole and oxidative stress, and increased resistance to targocil, fosfomycin and vancomycin. Levels of lipoteichoic acids (LTAs) were significantly reduced in pgl, which may limit cell lysis, while the surface charge of pgl cells was significantly more positive. A vraG mutation in pgl reversed the increased OX resistance phenotype, and partially restored wild-type surface charge, but not LTA levels. Mutations in vraF or graRS from the VraFG/GraRS complex that regulates DltABCD-mediated d-alanylation of teichoic acids (which in turn controls β-lactam resistance and surface charge), also restored wild-type OX susceptibility. Collectively these data show that reduced levels of LTAs and OX-induced lysis combined with a VraFG/GraRS-dependent increase in cell surface positive charge are accompanied by significantly increased OX resistance in an MRSA pgl mutant. (266 words)
12
Li, Ben, Yumeng Ji, Chenlong Yi, et al. "Rutin Inhibits Ox-LDL-Mediated Macrophage Inflammation and Foam Cell Formation by Inducing Autophagy and Modulating PI3K/ATK Signaling." Molecules 27, no. 13 (2022): 4201. http://dx.doi.org/10.3390/molecules27134201.
Full textAbstract:
Atherosclerosis (AS) is one of the leading causes of death among the elderly, and is primarily caused by foam cell generation and macrophage inflammation. Rutin is an anti-inflammatory, anti-oxidant, anti-allergic, and antiviral flavonoid molecule, known to have anti-atherosclerotic and autophagy-inducing properties, but its biological mechanism remains poorly understood. In this study, we uncovered that rutin could suppress the generation of inflammatory factors and reactive oxygen species (ROS) in ox-LDL-induced M2 macrophages and enhance their polarization. Moreover, rutin could decrease foam cell production, as shown by oil red O staining. In addition, rutin could increase the number of autophagosomes and the LC3II/I ratio, while lowering p62 expression. Furthermore, rutin could significantly inhibit the PI3K/ATK signaling pathway. In summary, rutin inhibits ox-LDL-mediated macrophage inflammation and foam cell formation by inducing autophagy and modulating PI3K/ATK signaling, showing potential in treating atherosclerosis.
13
Su, Min, Li Wei Tang, Sheng Wang, Hao Dan Liu, and Sheng Chen. "Synthesis and Electrochromic Properties of Soluble Polythiophenes." Advanced Materials Research 476-478 (February 2012): 1383–87. http://dx.doi.org/10.4028/www.scientific.net/amr.476-478.1383.
Full textAbstract:
Two kinds of 3-alkoxythiophene monomers were synthesized by the nucleophilic substitution and transetherification reactions. Soluble conjugated polymers based on 3-alkoxythiophene were synthesized by electrochemical polymerization. The process of the electrochemical polymerization, electrochemical redox behaviors and electrochromis of the polymer were investigated by the cyclic voltammetry and spectroelectrochemical measurement. The onset oxidation potentials (Eonset(ox)) of both POT and OOT were at 1040mV (vs. Ag/AgCl) in electrolyte solution system.The oxidation and reduction potential of PPOT and POOT were observed between +600 mV and +900mV (vs. Ag/AgCl). The color of POOT film on the platinum electrode was blue-green for oxidation state and was dark red for reduction state, in accordance with the UV-vis spectra behaviors.
14
Liu, Haiyun, Changpeng Zuo, Lijuan Cao, Naiquan Yang, and Tingbo Jiang. "Inhibition of miR-652-3p Regulates Lipid Metabolism and Inflammatory Cytokine Secretion of Macrophages to Alleviate Atherosclerosis by Improving TP53 Expression." Mediators of Inflammation 2022 (October 7, 2022): 1–11. http://dx.doi.org/10.1155/2022/9655097.
Full textAbstract:
Purpose. The aim was to elucidate the regulatory function of miR-652-3p on lipid metabolism and inflammatory cytokine secretion of macrophages in atherosclerosis. Methods. miR-652-3p level in atherosclerosis patients, ox-LDL-treated macrophages, and their controls were monitored by Q-PCR. After ox-LDL treatment and miR-652-3p mimic, si-TP53 and their controls transfection, ELISA, and Q-PCR assays were used to detect IL-1ß, IL-6, and TNF-α levels. oil red O staining was processed to verify cholesterol accumulation. CE/TC and lipid metabolism were also detected. The protein levels of ABCA1, ABCG1, PPARα, CRT1, ADRP, and ALBP were detected by western blot assay. Based on the TargetScan database, the TP53 3 ′ UTR region had complementary bases with miR-652-3p, which was also verified by dual-luciferase reporter gene assay. Finally, the regulation of miR-652-3p and TP53 was confirmed by rescue assay in atherosclerosis. Results. miR-652-3p is highly expressed in atherosclerosis, miR-652-3p inhibitor decreased IL-1β, IL-6, and TNF-α expression after ox-LDL treatment. Knockdown of miR-652-3p reduces foam formation in ox-LDL-treated macrophages. miR-652-3p inhibitor ameliorates cholesterol accumulation and lipid metabolism disorder. miR-652-3p negatively regulated TP53 in atherosclerosis. Si-TP53 rescued the effect of miR-652 inhibitor in atherosclerosis. Conclusion. miR-652-3p regulates the lipid metabolism of macrophages to alleviate atherosclerosis by inhibiting TP53 expression. It might be a potential target for atherosclerosis treatment.
15
Chernomorskii, Alexandr I. "(Digital Presentation) The Intermediate Electron Bond. Half-Reactions and the Electronic Structure of Atoms." ECS Meeting Abstracts MA2024-01, no. 44 (2024): 2491. http://dx.doi.org/10.1149/ma2024-01442491mtgabs.
Full textAbstract:
The transfer of electrons ne from the intermediate state (Ox1 ← ne → Ox2) is associated with formation of a chemical bond with one Ox-form. Consequently, chemical bonds of electrons with Ox - forms should be formed Ox + ne + H2O→ Red or broken Red + H2O → Ox + ne in half-reactions. Then, there should be concluded some electronic state and bond without a specific chemical component. This electronic bond was determined as a definite coulomb bond, intermediate from metallic to non-metallic specific bonds. Ionization potential of intermediately bound electrons is determined I interm. = 5.19 eV [1-4]. The chemical energy released in half-reactions-interactions is spent at once on separation of formed oppositely charged electrons and ions, polarization of water molecules of formed intermediate complexes. External potential differences appear between charged particles (double layers). Electrons and ions acquire electrochemical potentials, and electrochemical equilibriums are established. Exchange of formed electrons with electrons of electrodes stabilizes half-reactions. At that, a contact potential drop (not associated with interaction) appears in the electrode surface. However, only potential drops in double layers need to be taken into account. The rates of half-reactions-interactions change with changes in potential drops in double layers during electrical polarization. An important determination of ionization energy I interm. = 5.19 eV based on the found linear relationships between the first ionization potentials I of elements (related to the main groups) and their reversal covalent atomic radii 1/ r atom (Fig. 1). The linear relations cross when I interm. = 5.19 eV at 1/ r atom = 0.35 Ằ-1 ( r atom = 2.79 Ằ). It is concluded, that a specific electron bond formation with wave overlap begins with r atom = 2.79 Ằ at I interm. = 5.19 eV. Taking r interm. = 2.79 Ằ, ionization potential I interm. was calculated as coulomb energy of attraction between electron and polarized positive charge on Ox - form [2 - 4] I interm. =- e 2/ r interm. = - (4.8.10-10 e.s.u.)2 / 1.6.10-12 erg/eV . r interm. .10-8 cm = = - 14.4 . 10-8eV.cm/2.79.10-8cm = - 5.19 eV (1) According to linear relations (Fig.1), for similar elements, the first ionization potentials I are equal I = 5.19 eV + Δ I (2) when energies of formation of specific electronic bonds Δ I are changed by quanta. The quantum linear oscillator model is applied Δ I = (Δ n + ½) h ν o (3) where h is Plank constant, ν o is the natural frequency of electron - wave, Δ n are numbers of quantum jumps, Δ I = ½ hν o is the point zero energy [4,5]. It is concluded, that quantum jumpsΔ n = 8 - n = 1, 2, 3... should be counted from the orbital n = 8 on which electron localization and specific bonding is absent (8th period is absent in the Periodic System). However, the coulomb non-specific electronic bonding ( I interm. = 5.19 eV) must be preserved (Figh.1). Indeed, the first ionization potentials of elements of the 7th period are ~ 5 eV (5.17 eV for Ac). Therefore, Δ n = 1, Δ n = 2, Δ n = 3 ... correspond to one, two, three electron jumps necessary to reach the localization orbital related to the 7th, 6th, 5th .... (and so on) periods. First, using these Δ n , close natural frequencies ν o of electron waves were calculated for similar atoms as ν o = I - 5.19 eV / (Δ n + ½) h (4) For example, calculated ν o are for I (0.364.1015 s-1), Br (0.358.1015 s-1), Cl (0.344.1015 s-1), F (0.347 .1015 s-1). Using even the average natural frequency (0.35.1015 s-1), the first ionization potentials I (close to reference) were then calculated as the sums (Eqn.2). I = 5.19 eV + Δ I = 5.19 eV + (Δ n + ½) hν o (5) for most of elements. For example, for elements of the 7th main groups: I 10.3 eV (10.4 eV), Br 11.75 eV (11.8 eV), Cl 13.1 eV (13.0 eV), F 17.5 eV (17.4 eV). Emission wavelengths are also determined [4]. Therefore, the quantum-mechanical oscillator model can be applied to electron localization in atoms and to formation and breaking of specific chemical electron bonds with Ox - forms in half-reactions. In both cases, electron - waves pass to (or from) the intermediate state I interm. = 5.19 eV corresponding to the absence of specific bond formation. References A.I Chernomorskii, Russian Journal of Physical Chemistry, 55(2)1981. A.I. Chernomorskii, Thermodynamics of Electrodes (FAN,Tashkent,1993); A.I Chernomorskii, Journal of The Electrochemical Society, 2021, 168, 116514 A.I Chernomorskii, The intermediate electron bond and half-reactions (Scientific Resources, N-Y) (1999). P. Atkins, Julio de Paula, Physical Chemistry (W.H. Freeman and company,2006). Figure 1
16
Cao, Hui, Qingling Jia, Li Yan, Chuan Chen, Sanli Xing, and Dingzhu Shen. "Quercetin Suppresses the Progression of Atherosclerosis by Regulating MST1-Mediated Autophagy in ox-LDL-Induced RAW264.7 Macrophage Foam Cells." International Journal of Molecular Sciences 20, no. 23 (2019): 6093. http://dx.doi.org/10.3390/ijms20236093.
Full textAbstract:
Objective: To investigate the process by which quercetin suppresses atherosclerosis by upregulating MST1-mediated autophagy in RAW264.7 macrophages. Methods: An in vitro foam cell model was established by culturing RAW264.7 macrophages with oxidized low-density lipoprotein (ox-LDL). The cells were treated with quercetin alone or in combination with the autophagy inhibitor, 3-methyladenine, and autophagy agonist, rapamycin. Cell viability was detected with a CCK-8 kit. Lipid accumulation was detected by oil red O staining, senescence was detected by SA-β-gal (senescence-associated β-galactosidase) staining, reactive oxygen species were detected by ROS assay kit. Autophagosomes and mitochondria were detected by transmission electron microscope (TEM), and expression of MST1, LC3-II/I, Beclin1, Bcl-2, P21, and P16 were detected by immunofluorescence and Western blot. Results: Ox-LDL induced RAW264.7 macrophage-derived foam cell formation, reduced survival, aggravated cell lipid accumulation, and induced a senescence phenotype. This was accompanied by decreased formation of autophagosome; increased expression of P53, P21, and P16; and decreased expression of LC3-II/I and Beclin1. After intervention with quercetin, the cell survival rate was increased, and lipid accumulation and senescence phenotype were reduced. Furthermore, the expression of LC3-II/I and Beclin1 were increased, which was consistent with the ability of quercetin to promote autophagy. Ox-LDL also increased the expression of MST1, and this increase was blocked by quercetin, which provided a potential mechanism by which quercetin may protect foam cells against age-related detrimental effects. Conclusion: Quercetin can inhibit the formation of foam cells induced by ox-LDL and delay senescence. The mechanism may be related to the regulation of MST1-mediated autophagy of RAW264.7 cells.
17
Bian, Yuan, Wenqiang Cai, Hongying Lu, Shuhong Tang, Keqin Yang, and Yan Tan. "miR-150-5p affects AS plaque with ASMC proliferation and migration by STAT1." Open Medicine 16, no. 1 (2021): 1642–52. http://dx.doi.org/10.1515/med-2021-0357.
Full textAbstract:
Abstract We explore miR‐150‐5p in atherosclerosis (AS). The AS model was constructed using Apo E−/− mice with an injection of the miR-150-5p mimic or an inhibitor. Pathological characteristics were assessed using Oil red O staining and Masson staining. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and Western blot were used to analyze the expressions of microRNA-150-5p (miR-150-5p), STAT1, α-SMA (α-smooth muscle actin) and proliferating cell nuclear antigen (PCNA). Targetscan and dual-luciferase reporter assay were used to analyze the interaction between miR-150-5p and STAT1. The viability, migration, cell cycle and α-SMA and PCNA expressions in oxidized low-density lipoprotein (ox-LDL)-stimulated primary human aortic smooth muscle cells (ASMCs) were assessed using molecular experiments. miR-150-5p was reduced in both AS mice and ox-LDL-stimulated human aortic smooth muscle cells but STAT1 had the opposite effect. The miR‐150‐5p inhibitor alleviated the increase of lipid plaque and reduced collagen accumulation in the aortas during AS. Upregulation of α-SMA and PCNA was reversed by miR-150-5p upregulation. STAT1 was targeted by miR‐150‐5p, and overexpressed miR-150-5p weakened the ox-LDL-induced increase of viability and migration abilities and blocked cell cycle in ASMCs, but overexpressed STAT1 blocked the effect of the miR‐150‐5p mimic. This paper demonstrates that miR-150-5p has potential as a therapeutic target in AS, with plaque stabilization by regulating ASMC proliferation and migration via STAT1.
18
Morcuende, D., C. Vallejo-Torres, S. Ventanas, S. L. Martínez, S. C. Ruiz, and M. Estévez. "Effectiveness of Sprayed Bioactive Fruit Extracts in Counteracting Protein Oxidation in Lamb Cutlets Subjected to a High-Oxygen MAP." Foods 9, no. 11 (2020): 1715. http://dx.doi.org/10.3390/foods9111715.
Full textAbstract:
High-oxygen packaging atmosphere (High-Ox-MAP) promotes meat protein oxidation and leads to texture deterioration. This study was conceived to assess the extent to which sprayed fruit extracts could inhibit the oxidative damage to proteins in lamb cutlets subjected to High-Ox-MAP (10 days/4 °C) and subsequent roasting (10 min/180 °C). Extracts from oaknut (Quercus ilex subsp. ballota; QI), rose hips (Rosa canina L.; RC), common hawthorn (Crataegus monogyna Jacq.; CM) and strawberry tree (Arbutus unedo L.; AU) were characterized for bioactive compounds (phenolic subclasses, tocopherols and ascorbic acid) and in vitro bioactivities. While the four fruits showed relevant antioxidant potential, CM had the highest phenolics and tocopherol content and that was reflected in efficient antiradical activity. The in vitro activity of this fruit to inhibit meat protein oxidation was, however, lower than that displayed by the other fruits. Taking the results altogether, CM was also found to be most efficient in protecting lamb cutlets from lipid oxidation. All fruits were able to inhibit thiols oxidation except RC, which seemed to reduce protein thiols. Among fruits, QI was the most efficient in protecting lamb cutlets against protein carbonylation as a plausible involvement of ellagitannins. The inhibition of protein oxidation by QI was reflected in significantly lower instrumental hardness in cooked lamb cutlets. Spraying lamb cutlets with extracts from QI, RC and CM improved consumers’ purchase intention after chilled storage. This antioxidant strategy seems to be a feasible and efficient solution to the pro-oxidative effects caused by High-Ox-MAP in red meat.
19
Salman, Mustafa, Gülay Çiftçi, and Alper Çiftçi. "Influence of rumen-protected choline on blood red-ox potential and biochemical biomarkers of dairy cows during the transition period." Medycyna Weterynaryjna 73, no. 8 (2017): 483–87. http://dx.doi.org/10.21521/mw.5757.
Full textAbstract:
The aim of this study was to determine the serum oxidative status, antioxidant capacity, and oxidative stress index, as well as aspartate aminotransferase (AST), alanine aminotransferase (ALT) and creatinine profiles, of dairy cows fed rumen-protected choline during the transition period. A total of thirty dairy cows allotted to one control and two experimental groups (10 animals per group) were fattened from 3 weeks prior to the expected calving date until 3 weeks postpartum. The control group was fed a basal diet, and treatment groups 1 and 2, were fed a basal diet containing 60 g/head/day and 120 g/head/day or rumen-protected choline, respectively. Serum total antioxidant status (TAS) levels for the control group and treatment groups 1 and 2 at the time of parturition were 0.56±0.029ab, 0.45±0.028b, and 0.59±0.036a, respectively. The differences between the groups were statistically significant (P<0.05). Rumen-protected choline supplementation did not have a significant effect on TAS levels in the third week before parturition and in the first and third weeks of lactation. There were no significant differences (P>0.05) between the groups in terms of total oxidative status (TOS), oxidative stress index (OSI) or creatinine levels. Serum ALT levels were significantly different (P<0.05) between the groups at parturition and in the first week of lactation, but not significant (P>0.05) for the other periods. In addition, the serum AST level was significantly different (P<0.05) between the groups in the first and third weeks of lactation, but not significantly different (P>0.05) for the other periods. After removing the effect of groups, time-dependent changes were significant (P<0.001) for all parameters. The highest values for TAS, TOS and OSI were obtained in the third week before parturition. The values for these parameters decreased during parturition and after the postnatal period. The lowest values for serum ALT and creatinine occurred at parturition. Rumen-protected choline supplementation did not have a significant effect on serum TAS and TOS levels during the transition period. There is a need for further studies of animals with known metabolic profiles, malnourished animals, and those with high milk yields or metabolic disorders.
20
Callaghan, G. E., M. H. Anil, J. L. McKinstry, and A. V. Fisher. "Arterial blood supply to the head of red deer." Proceedings of the British Society of Animal Science 1995 (March 1995): 202. http://dx.doi.org/10.1017/s1752756200591960.
Full textAbstract:
Continuation of arterial blood supply to the head following slaughter of certain ruminant meat animal species can lead to delays in loss of sensibility and present welfare problems. This sometimes occurs in cattle due to an anastomosis linking the vertebral arteries to the carotid rete. The arterial supply to the head of the ox was found to differ from that of the sheep. In the ox the vertebral arteries can supply blood to the carotid rete via the basi-occipital plexus (Baldwin and Bell, 1963). This additional anastomosis means that there is still a potential blood supply to the head after the carotids have been severed by neck sticking Anil et al, 1995). Blood clots on the severed carotid arteries following neck sticking can occur in up to 40% of cases to varying degrees and sometimes lead to occlusions for a number of reasons. This phenomenon of carotid occlusion means the occipital-vertebral anastomosis and the vertebral-carotid rete anastomosis take on more importance when neck sticking is used. This is especially true for religious slaughter and neck sticking where electrical stunning is used. It is not clear whether such an anastomosis exists in the head of red deer. The traditional and still legal method of slaughter of farmed deer is by head shot in the field, however, there has been an increase in the number of deer being culled in abattoirs. In addition, there have been recent suggestions that religious slaughter without stunning may be initiated in the U.K. abattoirs. This possibility and and the increased number of abattoirs slaughtering deer have prompted this study to look at the arterial blood supply in the head of the deer. This increase combined with the problems of arterial supply found in cattle has prompted this study.
21
Callaghan, G. E., M. H. Anil, J. L. McKinstry, and A. V. Fisher. "Arterial blood supply to the head of red deer." Proceedings of the British Society of Animal Science 1995 (March 1995): 202. http://dx.doi.org/10.1017/s0308229600029676.
Full textAbstract:
Continuation of arterial blood supply to the head following slaughter of certain ruminant meat animal species can lead to delays in loss of sensibility and present welfare problems. This sometimes occurs in cattle due to an anastomosis linking the vertebral arteries to the carotid rete. The arterial supply to the head of the ox was found to differ from that of the sheep. In the ox the vertebral arteries can supply blood to the carotid rete via the basi-occipital plexus (Baldwin and Bell, 1963). This additional anastomosis means that there is still a potential blood supply to the head after the carotids have been severed by neck sticking Anil et al, 1995). Blood clots on the severed carotid arteries following neck sticking can occur in up to 40% of cases to varying degrees and sometimes lead to occlusions for a number of reasons. This phenomenon of carotid occlusion means the occipital-vertebral anastomosis and the vertebral-carotid rete anastomosis take on more importance when neck sticking is used. This is especially true for religious slaughter and neck sticking where electrical stunning is used. It is not clear whether such an anastomosis exists in the head of red deer. The traditional and still legal method of slaughter of farmed deer is by head shot in the field, however, there has been an increase in the number of deer being culled in abattoirs. In addition, there have been recent suggestions that religious slaughter without stunning may be initiated in the U.K. abattoirs. This possibility and and the increased number of abattoirs slaughtering deer have prompted this study to look at the arterial blood supply in the head of the deer. This increase combined with the problems of arterial supply found in cattle has prompted this study.
22
Zieba, Wojciech, Joanna Czarnecka, Tomasz Rusak, Monika Zieba, and Artur P. Terzyk. "Nitric-Acid Oxidized Single-Walled Carbon Nanohorns as a Potential Material for Bio-Applications—Toxicity and Hemocompatibility Studies." Materials 14, no. 6 (2021): 1419. http://dx.doi.org/10.3390/ma14061419.
Full textAbstract:
The results of in vitro studies of single-walled carbon nanohorn (SWCNH) oxidized materials’ cytotoxicity obtained by the cell membrane integrity (Neutral Red Uptake (NRU)) and metabolic activity (by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)) on A549 and human dermal fibroblasts (HDF) cell lines are presented. We also present hemocompatibility studies on human and porcine blood, and an erythrocyte concentrate to prove that the obtained samples will not interfere with blood components. Characterization of the materials is supplemented by ζ-potential measurements, Transmission Electron Microscope (TEM) imaging, and thermogravimetric studies (TG). The presented results show the correlation between the specific surface area of materials and the platelet aggregation, when the ID/IG ratio determined from Raman spectra correlates with hemoglobin release from the erythrocytes (in whole blood testing). A plausible mechanism explaining the observed correlations is given. The cytotoxicity and hemocompatibility studies prove that the studied materials are acceptable for use in biomedical applications, especially a sample SWCNH-ox-1.5 with the best application potential.
23
Wang, Gang, Shu-Yan Jing, Gang Liu, et al. "miR-99a-5p: A Potential New Therapy for Atherosclerosis by Targeting mTOR and Then Inhibiting NLRP3 Inflammasome Activation and Promoting Macrophage Autophagy." Disease Markers 2022 (August 5, 2022): 1–13. http://dx.doi.org/10.1155/2022/7172583.
Full textAbstract:
Objective. MicroRNAs have been revealed to be involved in the development of atherosclerosis. The present study is aimed at exploring the potential of miR-99a-5p as a therapy for atherosclerosis. We suspected that miR-99a-5p might inhibit NLRP3 inflammasome activation and promote macrophage autophagy via constraining mTOR, therefore, alleviating atherosclerosis. Methods. The cell viability in ox-LDL-induced THP-1 macrophages was assessed by CCK-8 assay. Bioinformatic analysis was used to predict the target genes of miR-99a-5p. The binding between miR-99a-5p and mTOR was confirmed by luciferase reporter assay. In vivo, a high-fat-diet-induced atherosclerosis model was established in apolipoprotein E knockout mice. Hematoxylin-eosin, oil red O, and Sirius red staining were performed for the determination of atherosclerotic lesions. MTOR and associated protein levels were detected by Western blot analysis. Results. miR-99a-5p inhibited NLRP3 inflammasome activation and promoted macrophage autophagy by targeting mTOR. Enforced miR-99a-5p significantly reduced the levels of inflammasome complex and inflammatory cytokines. Furthermore, miR-99a-5p overexpression inhibited the expression of mTOR, whereas mTOR overexpression reversed the trend of the above behaviors. In vivo, the specific overexpression of miR-99a-5p significantly reduced atherosclerotic lesions, accompanied by a significant downregulation of autophagy marker CD68 protein expression. Conclusion. We demonstrated for the first time that miR-99a-5p may be considered a therapy for atherosclerosis. The present study has revealed that miR-99a-5p might inhibit NLRP3 inflammasome activation and promote macrophage autophagy by targeting mTOR, therefore, alleviating atherosclerosis.
24
Grygoyć, Katarzyna, and Magdalena Jabłońska-Czapla. "Development of a Tellurium Speciation Study Using IC-ICP-MS on Soil Samples Taken from an Area Associated with the Storage, Processing, and Recovery of Electrowaste." Molecules 26, no. 9 (2021): 2651. http://dx.doi.org/10.3390/molecules26092651.
Full textAbstract:
The optimization and validation of a methodology for determining and extracting inorganic ionic Te(VI) and Te(IV) forms in easily-leached fractions of soil by Ion Chromatography-Inductively Coupled Plasma-Mass Spectrometry (IC-ICP-MS) were studied. In this paper, the total concentration of Te, pH, and red-ox potential were determined. Ions were successfully separated in 4 min on a Hamilton PRPX100 column with 0.002 mg/kg and 0.004 mg/kg limits of detection for Te(VI) and Te(IV), respectively. Soil samples were collected from areas subjected to the influence of an electrowaste processing and sorting plant. Sequential chemical extraction of soils showed that tellurium was bound mainly with sulphides, organic matter, and silicates. Optimization of soil extraction allowed 20% average extraction efficiency to be obtained, using 100 mM citric acid as the extractant. In the tested soil samples, both tellurium species were present. In most cases, the soils contained a reduced Te form, or the concentrations of both species were similar.
25
Jang, Minhee, Min Jung Lee, Cheon Suk Kim, and Ik-Hyun Cho. "Korean Red Ginseng Extract Attenuates 3-Nitropropionic Acid-Induced Huntington’s-Like Symptoms." Evidence-Based Complementary and Alternative Medicine 2013 (2013): 1–17. http://dx.doi.org/10.1155/2013/237207.
Full textAbstract:
Korean red ginseng (KRG) possesses neuroprotective activity. However, the potential neuroprotective value of KRG for the striatal toxicity is largely unknown. We investigated whether KRG extract (KRGE) could have a neuroprotective effect in a 3-nitropropionic acid- (3-NP) induced (i.p.) Huntington’s disease (HD) model. KRGE (50, 100, and 250 mg/kg/day, p.o.) was administrated 10 days before 3-NP injection (pre-administration), from the same time with 3-NP injection (co-administration), or from the peak point of neurological impairment by 3-NP injection (post-administration). Pre-administration of KRGE produced the greatest neuroprotective effect in this model. Pre-administration of KRGE significantly decreased 3-NP-induced neurological impairment, lethality, lesion area, and neuronal loss in the 3-NP-injected striatum. KRGE attenuated microglial activation and phosphorylation of mitogen-activated protein kinases (MAPKs) and nuclear factor-kappa B (NF-κB) signal pathway. KRGE also reduced the level of mRNA expression of tumor necrosis factor-alpha, interleukin- (IL-) 1β, IL-6, inducible nitric oxide synthase, and OX-42. Interestingly, the intrathecal administration of SB203580 (a p38 inhibitor) or PD98059 (an inhibitor of MAPK Kinase, MEK) increased the survival rate in the 3-NP-induced HD model. Pre-administration of KRGE may effectively inhibit 3-NP-induced striatal toxicity via the inhibition of the phosphorylation of MAPKs and NF-κB pathways, indicating its therapeutic potential for suppressing Huntington’s-like symptoms.
26
Cao, Xu, Ke Ma, Yuhao Tao, Deyang Xi, Fangyu Hu, and Jingjing Li. "Specific Targeting MRI of Chitosan Oligosaccharide Modified Fe3O4 Nanoprobe on Macrophage and the Inhibition of Macrophage Foaming Induced by ox-LDL." Journal of Advances in Medicine Science 4, no. 2 (2021): 20. http://dx.doi.org/10.30564/jams.v4i2.3039.
Full textAbstract:
Atherosclerosis (AS) is a primary cause of morbidity and mortality all over the world. Molecular imaging techniques can enable early localization and diagnosis of atherosclerosis plaques. Recent newly developed chitooligosaccharides (CSO) is considered to be capable of target mannose receptors on the surface of macrophages and to inhibit foam cell formation. Here we present a targeting magnetic resonance imaging (MRI) nanoprobe, which was successfully constructed with polyacrylic acid (PAA) modified nanometer iron oxide (Fe3O4) as the core, and coating with CSO molecules, possessing the abilities of targeted MRI and specifically inhibition of the formation of foamy macrophages in the atherosclerotic process. The experimental results showed that the distributions of PAA-Fe3O4 and CSO-PAA-Fe3O4 were uniform and the corresponding sizes were about 5.93 nm and 8.15 nm, respectively. The Fourier transform infrared spectra (FTIR) testified the CSO was coupled with PAA-Fe3O4 successfully. After coupled with CSO, the r1 of PAA-Fe3O4 was increased from 5.317 mM s-1 to 6.147 mM s-1, indicating their potential as MRI contrast agent. Oil Red O staining and total cholesterols (TC) determination showed that CSO-PAA-Fe3O4 could significantly inhibit the foaming process of RAW264.7 cells induced by oxidatively modified low density lipoprotein (ox-LDL). In vitro cellular MRI displayed that, compared with PAA-Fe3O4,CSO-PAA-Fe3O4 could lower the T1 relaxation time of RAW264.7 cells better. In summary, construction of CSO-PAA-Fe3O4 nanoprobe in this study could realize the targeted MRI of macrophages and inhibition of ox-LDL induced macrophage foaming process. This will provide a new avenue in the diagnosis and treatment of AS.
27
Chen, Ting, Xiaoxiao Tan, Fan Xia, Ya Hua, Richard F. Keep, and Guohua Xi. "Hydrocephalus Induced by Intraventricular Peroxiredoxin-2: The Role of Macrophages in the Choroid Plexus." Biomolecules 11, no. 5 (2021): 654. http://dx.doi.org/10.3390/biom11050654.
Full textAbstract:
The choroid plexus (CP) is the primary source of cerebrospinal fluid in the central nervous system. Recent evidence indicates that inflammatory pathways at the CP may be involved in hydrocephalus development. Peroxiredoxin 2 (Prx2) is a major component of red blood cells. Extracellular Prx2 is proinflammatory, and its release after red blood cell lysis may contribute to hydrocephalus after intraventricular hemorrhage. This study aimed to identify alterations in CP macrophages and dendritic cells following intracerebroventricular Prx2 injection and investigate the relationship between macrophages/dendritic cells and hydrocephalus. There were two parts to this study. In the first part, adult male Sprague–Dawley rats received an intracerebroventricular injection of Prx2 or saline. In the second part, Prx2 was co-injected with clodronate liposomes or control liposomes. All animals were euthanized at 24 h after magnetic resonance imaging. Immunohistochemistry was used to evaluate macrophages in CP, magnetic resonance imaging to quantify hydrocephalus, and histology to assess ventricular wall damage. The intracerebroventricular injection of Prx2 not only increased the OX-6 positive cells, but it also altered their location in the CP and immunophenotype. Co-injecting clodronate liposomes with Prx2 decreased the number of macrophages and simultaneously attenuated Prx2-induced hydrocephalus and ventricular wall damage. These results suggest that CP macrophages play an essential role in CP inflammation-induced hydrocephalus. These macrophages may be a potential therapeutic target in post-hemorrhagic hydrocephalus.
28
Colica, Carmela, Maja Milanović, Nataša Milić, Vincenzo Aiello, Antonino De Lorenzo, and Ludovico Abenavoli. "A Systematic Review on Natural Antioxidant Properties of Resveratrol." Natural Product Communications 13, no. 9 (2018): 1934578X1801300. http://dx.doi.org/10.1177/1934578x1801300923.
Full textAbstract:
Polyphenols, including anthocyanins, flavonoids and stilbenes, which constitute one of the most abundant and ubiquitous groups of plant metabolites, are an integral part of the human diet. Resveratrol (3,5,4'-trihydroxystilbene), a naturally occurring polyphenol produced by some plants as a self-defence agent, has an antifungal activity. Resveratrol has been found in some plants (such as grapevine, pine and peanuts) and is considered to have beneficial effects also on human health. The number of studies on resveratrol greatly increased in PubMed database since 1997, after the anticancer effect of this molecule was first reported. The interest in resveratrol in grape was originally sparked by epidemiological studies indicating an inverse relationship between long-standing moderate consumption of red wine and the risk of coronary heart disease; this effect has been ascribed to resveratrol, which possesses diverse biochemical and physiological properties, including antiplatelet and anti-inflammatory proprieties, and provides a wide range of health benefits ranging from chemoprevention to cardioprotection. Recently, resveratrol has been described as an anti-aging compound. The consumption of resveratrol (red wine) together with a Mediterranean diet or a fast-food meal (“McDonald'sMeal”) had a positive impact on oxidized (ox-) LDL and on the expression of oxidative and inflammatory genes. Therefore, this review summarized the most important scientific data about healing and preventive potential of resveratrol, acting as cardioprotective, neuroprotective, chemopreventive and antioxidant agent.
29
Gjorgieva Ackova, Darinka, Jelena Kotur-Stevuljevic, Chandra Bhushan Mishra, Pratibha Mehta Luthra, and Luciano Saso. "Antioxidant Properties of Synthesized Bicyclic Thiazolopyrimidine Derivatives as Possible Therapeutic Agents." Applied Sciences 9, no. 1 (2018): 113. http://dx.doi.org/10.3390/app9010113.
Full textAbstract:
Oxidant/antioxidant imbalance in the body has been implicated as one of the pathophysiological mechanisms leading to disease development. Therefore, we searched for a good antioxidant candidate that can be used as a therapeutic agent alone or in combination with other reported drugs. Earlier, we reported the A2A receptor antagonist properties of 7-Imino-3-substituted-2-thioxo-3,7-dihydro-2H-thiazolo[4,5-d]pyrimidin-6-yl)-urea derivatives (compounds 1–12) and the neuroprotective effect of compound 2. Therefore, in the present work, the antioxidant potential of compounds 1–12 was studied. Compounds 1–12 were screened using different (red/ox) tests, such as the Ferric Reducing Antioxidant Power (FRAP) assay, to determine total antioxidant activity, redox status tests (with and without prooxidants) such as Advanced Oxidation Protein Products (AOPP) and Total Oxidative Status (TOS) which measures H2O2 and lipid hydroperoxides, Paraoxonase-1 Enzyme Activity (PON1), Total SH-groups content, and Total Antioxidative Status (TAS) for antioxidant determination. The Prooxidative Score, Antioxidative Score, and Oxy Score were also calculated. From the obtained results, compounds 6 (8720 FRAP value and 39.31 Oxy Score) and 12 (7866 FRAP value and 36.41 Oxy Score) were found to possess significant antioxidant activity with reasonable potential for therapeutic activity.
30
Oraz, U., A. Bayeshova, and A. Bayeshov. "Investigation of the process of formation of a chemical current source in the «red-ox» Fe(II) – Fe(III) system in a sulfuric acid environment." Bulletin of Shakarim University. Technical Sciences 1, no. 4(12) (2023): 195–203. http://dx.doi.org/10.53360/2788-7995-2023-4(12)-24.
Full textAbstract:
Among the technologies designed to save energy, flow-through batteries deserve special attention. Their principle of operation is based on the use of systems of variably valent ions. The aim of the work is to create a chemical current source based on the use of the "red – ox" Fe(II)/Fe(III) system and to determine the patterns of formation of electromotive force (EMF) and short-circuit current (SCC) in acidic solutions depending on the concentration of ions. The experiments are carried out by measuring the EMF formed between graphite electrodes and SCC. A special installation has been assembled, consisting of an electrolyzer with separated electrode spaces, an ammeter, a voltmeter and graphite electrodes. Acidified solutions of iron (II) and iron (III) sulfates served as the electrolyte. In an electrolyzer, the electrode spaces of which are separated by an anionite membrane, when one space is filled with iron (II) sulfate and the other with iron (III) sulfate, an EMF occurs between graphite electrodes. When making contact between graphite electrodes, iron (II) oxidation occurs in the first electrode space, and iron (III) reduction occurs in the second. A chemical current source is being formed. At a concentration of iron (III) equal to 20 g/l, a change in the concentration of iron (II) in the range of 1-40 g / l contributes to a shift in the potential of the graphite electrode to negative values. At a concentration of Fe(III) equal to 1 g/l, the potential value is 509 mV, and at 40 g / l – 475 mV. At a constant concentration of iron (II), the addition of Fe(III) leads to a shift in the EMF value to the right. It was found that as a result of these changes, an increase in EMF and SCC is observed.
31
Wang, Yu, Wei Wang, Haobo Xu, et al. "Non-Lethal Sonodynamic Therapy Inhibits Atherosclerotic Plaque Progression in ApoE-/- Mice and Attenuates ox-LDL-mediated Macrophage Impairment by Inducing Heme Oxygenase-1." Cellular Physiology and Biochemistry 41, no. 6 (2017): 2432–46. http://dx.doi.org/10.1159/000475913.
Full textAbstract:
Background: Previous studies from our group showed that low-intensity sonodynamic therapy (SDT) has protective effects on atherosclerosis (AS). However, because the intensity of ultrasound passing through tissue is attenuated, the consequences of very low-intensity SDT, referred to as non-lethal SDT (NL-SDT), on atherosclerotic plaques are unclear. The aim of this study was to determine whether NL-SDT affects atherosclerotic plaques and to elucidate the possible underlying mechanisms. Methods: An AS model was established using ApoE-/- mice fed a western diet. En face Oil Red O staining was used to measure atherosclerotic plaque size. Hematoxylin and eosin staining and immunohistochemical staining were used to observe plaque morphology and assess the location of macrophages and heme oxygenase 1 (HO-1). HO-1 mRNA and protein levels in AS plaques were evaluated by real-time PCR and western blotting. Human THP-1 cells and mouse peritoneal macrophages were used in this study. Western blotting was used to investigate the expression of cellular proteins after NL-SDT. Macrophage apoptosis was evaluated by TUNEL assays and flow cytometry with Annexin V/PI double staining. Intracellular reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) were measured with 2′-7′-dichlorofluorescein diacetate (DCFH-DA) and 5,5′,6,6′-tetrachloro-1,1′,3,3′-tetraethyl benzimidazolyl carbocyanine iodide (JC-1) staining, respectively. Results: NL-SDT significantly inhibited AS progression and reduced the necrotic core area. NL-SDT induced HO-1 expression in lesional macrophages and in cultured macrophages. NL-SDT activated the protein kinase B (AKT) and extracellular signal-related protein kinase (ERK) pathways and the transcription factor NF-E2-related factor 2 (Nrf2).NL-SDT significantly reduced oxidized LDL (ox-LDL)-induced macrophage MMP collapse, ROS production and cell apoptosis. Zinc protoporphyrin (ZnPP), a HO-1-specific inhibitor, reversed the protective effects of NL-SDT. Conclusion: NL-SDT inhibits atherosclerotic plaque progression and increases plaque stability. In vitro, NL-SDT has a protective effect on ox-LDL-induced macrophage impairment via HO-1.
32
Georgieva, Ekaterina, Vasil Atanasov, Rositsa Kostandieva, et al. "Direct Application of 3-Maleimido-PROXYL for Proving Hypoalbuminemia in Cases of SARS-CoV-2 Infection: The Potential Diagnostic Method of Determining Albumin Instability and Oxidized Protein Level in Severe COVID-19." International Journal of Molecular Sciences 24, no. 6 (2023): 5807. http://dx.doi.org/10.3390/ijms24065807.
Full textAbstract:
Oxidative stress and the albumin oxidized form can lead to hypoalbuminemia, which is a predisposing factor for reduced treatment effectiveness and an increased mortality rate in severe COVID-19 patients. The aim of the study is to evaluate the application of free radical 3-Maleimido-PROXYL and SDSL-EPR spectroscopy in the in vitro determination of ox/red HSA in serum samples from patients with SARS-CoV-2 infection. Venous blood was collected from patients intubated (pO2 < 90%) with a positive PCR test for SARS-CoV-2 and controls. At the 120th minute after the incubation of the serum samples from both groups with the 3-Maleimido-PROXYL, the EPR measurement was started. The high levels of free radicals were determined through the nitroxide radical TEMPOL, which probably led to increased oxidation of HSA and hypoalbuminemia in severe COVID-19. The double-integrated spectra of 3-Maleimido-PROXYL radical showed a low degree of connectivity due to high levels of oxidized albumin in COVID-19 patients. The low concentrations of reduced albumin in serum samples partially inhibit spin-label rotation, with Amax values and ΔH0 spectral parameters comparable to those of 3-Maleimido-PROXYL/DMSO. Based on the obtained results, we suggest that the stable nitroxide radical 3-Maleimido-PROXYL can be successfully used as a marker to study oxidized albumin levels in COVID-19.
33
ŻAROWSKA, BARBARA, TOMASZ KOŹLECKI, MICHAŁ PIEGZA, KATARZYNA JAROS-KOŹLECKA, and MAŁGORZATA ROBAK. "New Look on Antifungal Activity of Silver Nanoparticles (AgNPs)." Polish Journal of Microbiology 68, no. 4 (2019): 515–25. http://dx.doi.org/10.33073/pjm-2019-051.
Full textAbstract:
The progress of research on silver nanoparticles (AgNPs) has led to their inclusion in many consumer products (chemicals, cosmetics, clothing, water filters, and medical devices) as a biocide. Despite the widespread use of AgNPs, their biocidal activity is not yet fully understood and is usually associated with various factors (size, composition, surface, red-ox potential, and concentration) and, obviously, specific features of microorganisms. There are merely a few studies concerning the interaction of molds with AgNPs. Therefore, the determination of the minimal AgNPs concentration required for effective growth suppression of five fungal species (Paecilomyces variotii, Penicillium pinophilum, Chaetomium globosum, Trichoderma virens, and Aspergillus brasiliensis), involved in the deterioration of construction materials, was particularly important. Inhibition of bacteria (Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli) and yeasts (Candida albicans and Yarrowia lipolytica) was also assessed as the control of AgNPs effectiveness. AgNPs at the concentrations of 9–10.7 ppm displayed high inhibitory activity against moulds, yeast, and bacteria. The TEM images revealed that 20 nm AgNPs migrated into bacterial, yeast, and fungal cells but aggregated in larger particles (50–100 nm) exclusively inside eukaryotic cells. The aggregation of 20 nm AgNPs and particularly their accumulation in the cell wall, observed for A. brasiliensis cells, are described here for the first time.
34
Karwowski, Boleslaw T. "A Comparison of the Electronic Properties of Selected Antioxidants Vitamin C, Uric Acid, NAC and Melatonin with Guanosine Derivatives: A Theoretical Study." Molecules 29, no. 24 (2024): 5944. https://doi.org/10.3390/molecules29245944.
Full textAbstract:
Each cell in the human body is continually exposed to harmful external and internal factors. During evolution, cells have developed various defence systems, divided into enzymatic and non-enzymatic types, to which low-weight molecule antioxidants belong. In this article, the ionisation potential and electron affinity, as well as global reactivity descriptors of Vitamin C, Melatonin, Uric Acids, and N-acetyl-L-cysteine, were theoretically investigated at the MP-2/aug-cc-pVTZ level of theory in the condensed (aqueous) phase. The vertical ionisation potential and electron affinity are discussed in terms of non-equilibrated and equilibrated solvent–solute interactions. Additionally, at the same theoretical level, the electronic properties of canonical and oxidised derivatives of guanine were analysed. The presented results indicate that the selected antioxidants for this study (Vitamin C, Uric Acid, NAC, and Melatonin) exhibit the highest adiabatic electron affinity, while guanine derivatives (Gua, OXOGua, Guo, dGuo, OXOGuo, OXOdGuo) are more prone to adiabatic radical cation formation. A red-ox balance (redox homeostasis) is crucial for intracellular signalling pathways that are reactive oxygen and nitrogen species (RO/NS)-dependent. Should this gentle balance be disrupted, either by an overload or deficit of species, physiological consequences may result, which in turn lead to pathological outcomes. On the other hand, maintaining the stability of the above balance of antioxidants/radicals may result in the improved effectiveness and safety of anticancer radiotherapy/chemotherapy or combined therapies with a subsequent increase in a patient’s quality of life.
35
Jiang, Qian, Hua Zhang, Runqiang Yang, et al. "Red-Osier Dogwood Extracts Prevent Inflammatory Responses in Caco-2 Cells and a Caco-2 BBe1/EA.hy926 Cell Co-Culture Model." Antioxidants 8, no. 10 (2019): 428. http://dx.doi.org/10.3390/antiox8100428.
Full textAbstract:
Red-osier dogwood extracts (RDE) contain high levels of phenolic compounds which have been recognized as natural antioxidants. In this study, the potential of RDE to prevent cardiovascular diseases (CVDs) was evaluated using Caco-2 cells and a co-culture model of Caco-2 BBe1/EA.hy926 cells in Transwell® plates. The results showed that RDE supplementation significantly prevented interleukin-8 (IL-8) production and suppressed the gene expression of IL-8, tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and cyclooxygenase 2 (COX-2) in the TNF-α inflamed Caco-2 cells. Meanwhile, the polyphenols (quercetin-3-glucoside, quercetin-glucuronide, rutin, quercetin-3-O-malonylglucoside, and kaempferol-glucoside) in the RDE were validated to be absorbed by Caco-2 BBe1 cells and transported to the basal chamber where EA.hy926 cells were located during 12 h incubation. The transported polyphenols were able to prevent IL-8 production and suppress the gene expression of proinflammatory mediators (TNF-α, ICAM-1, VCAM-1, and COX-2) in the TNF-α or oxidized low-density lipoprotein (ox-LDL) treated EA.hy926 cells. These novel findings demonstrated that phenolic compounds in RDE can be transported to the cardiovascular system by intestinal absorption and mitigate the inflammatory responses of vascular endothelial cells, indicating that RDE could be a natural resource of polyphenols to prevent inflammation cytokine or oxidized lipid-induced CVDs.
36
Chiu, Chih-Wei, Chih-Hao Yang, Jie-Heng Tsai, Cheng-Ying Hsieh, and Shih-Yi Huang. "Platonin, a Cyanine Photosensitizing Dye, Ameliorates Inflammatory Responses in Vascular Smooth Muscle Cells by Modulating Inflammatory Transcription Factors." Applied Sciences 11, no. 3 (2021): 1130. http://dx.doi.org/10.3390/app11031130.
Full textAbstract:
Inflammation of the arterial wall is critical to atherosclerosis pathogenesis. The switch of vascular smooth muscle cells (VSMCs) to macrophage-like cells is essential in the exacerbation of vascular inflammation. Platonin, a cyanine photosensitizing dye, exhibits protective effects in sepsis, trauma, and acute ischemic stroke through its anti-inflammatory capacity in macrophages. The present study investigated the effects and underlying mechanisms of platonin in inflammatory VSMCs. Pretreatment with platonin suppressed the expression of inducible nitric oxide synthetase and mature interleukin-1β but not that of monocyte chemoattractant protein-1 (MCP-1) in VSMCs stimulated by a combination of lipopolysaccharide and interferon-γ (LPS/IFN-γ). Furthermore, platonin inhibited LPS/IFN-γ-induced Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activation though the direct reduction of p65Ser536 phosphorylation but not the restoration of Inhibitor of nuclear factor kappa B (IκBα) degradation in VSMCs. However, platonin inhibited Oxidized low-density lipoprotein (ox-LDL)-induced MCP-1 production, possibly through the attenuation of Activator protein 1 (AP-1) binding activity and C-Jun N-terminal kinases ½ (JNK1/2) phosphorylation. Platonin also lowered lipid drop accumulation in VSMCs in Oil red O staining assay. The results collectively indicated that platonin has a vascular protective property with potent anti-inflammatory effects in VSMCs. In conclusion, platonin should be a potential for treating vascular inflammatory diseases such as atherosclerosis.
37
Jiang, Ting, Kun Ren, Qian Chen та ін. "Leonurine Prevents Atherosclerosis Via Promoting the Expression of ABCA1 and ABCG1 in a Pparγ/Lxrα Signaling Pathway-Dependent Manner". Cellular Physiology and Biochemistry 43, № 4 (2017): 1703–17. http://dx.doi.org/10.1159/000484031.
Full textAbstract:
Background/Aims: Previous studies have demonstrated that leonurine, a unique alkaloid compound of Herba leonuri, can exert anti-oxidative and anti-inflammatory effects on the development of atherosclerosis (AS). This study was designed to investigate the effects of leonurine on cholesterol efflux from THP-1 macrophage-derived foam cells and development of atherosclerotic lesions in apoE-/- mice, and further determine the potential mechanisms. Methods: Human THP-1 cells were fully differentiated into foam cells by the pre-treatment with phorbol-12-myristate-13-acetate (PMA) and oxidized density lipoproteins (ox-LDL). After cells were incubated with various concentrations of leonurine, Oil Red O staining and high-performance liquid chromatography (HPLC) assays were utilized to detect cellular lipid accumulation and cholesterol content, respectively. Cellular cholesterol efflux was determined by liquid scintillation counting. The mRNA and protein levels of ATP-binding cassette transporter A1/G1 (ABCA1/G1), peroxisome proliferator-activated receptor γ (PPARγ) and liver X receptor α (LXRα) in foam cells were assessed using real-time quantitative PCR (RT-qPCR) and western blot analyses, respectively. Plasma triglyceride (TG), total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-C) and low-density lipoprotein-cholesterol (LDL-C) levels in apoE-/- mice were evaluated using enzymatic methods. The atherosclerotic lesion sizes and collagen contents in aortic roots were determined by Oil Red O and Masson’s trichrome staining, respectively. Results: Oil Red O staining and liquid scintillation counting assays showed that leonurine significantly inhibited lipid accumulation and promoted 3H-cholesterol efflux in human THP-1 macrophage-derived foam cells in a concentration-dependent manner. Besides, both the mRNA and protein levels of ABCA1/G1, PPARγ and LXRα were enhanced by leonurine, which were attenuated by LXRα siRNA or PPARγ siRNA transfection. Finally, leonurine improved plasma lipid profile, decreased atherosclerotic lesion sizes, increased collagen contents and amplified PPARγ, LXRα and ABCA1/G1 expressions in aortic roots of apoE-/- mice. Conclusions: Leonurine can promote cholesterol efflux and alleviate cellular lipid accumulation by magnifying the expression of ABCA1/G1 in a PPARγ/LXRα signaling pathway-dependent manner in human THP-1 macrophage-derived foam cells and abate atherogenesis in apoE-/- mice, which may offer a promising therapeutic intervention of leonurine in protecting against AS.
38
Castrucci, Mauro, Mauro Tomassetti, Emanuele Dell’Aglio, Giovanni Visco, Maria Pia Sammartino, and Marco Castracane. "Chemical, Diagnostic, and Instrumental Analysis of an Ancient Roman Cippus funebris from the First Century AD." Analytica 6, no. 1 (2025): 11. https://doi.org/10.3390/analytica6010011.
Full textAbstract:
A diagnostic chemical analysis has been performed on a Roman Cippus funebris in precious white marble located close to an ancient Roman road. The Cippus was in good condition but almost completely covered by a black patina, requiring a conservative cleaning intervention. The restorer in charge of the restoration asked us to make a preliminary diagnosis, on the basis of which we could suggest the most appropriate intervention. The Cippus was dedicated to the young Quintus Cornelius Proclianus, who died at the age of 15, by his mother Valeria Calpurnia Scopele. It perfectly fits into the Roman funerary liturgy and also shows an Etruscan-type iconography that seems to confirm the Etruscan Gens of the family and its dating to the 1st century AD. Ion chromatography (IC) analyses were performed to determine anions and cations on solutions obtained from the extraction of salts from the four samples of the Cippus. pH, conductivity, and red-ox potential measures, as well as UV-visible spectra were carried out on the same solutions. A small fragment, spontaneously fallen from the Cippus’ surface, was also observed by optical microscopy (OM) and scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS). From the analyses, the dark patina that covered the surface before cleaning turned out to be made of black crusts, that is, smog particles adsorbed on sulfates, but above all, by a layer of microflora. The results allowed us to suggest some conservative interventions.
39
Zhu, Guoqi, Yan Lai, Fei Chen, et al. "Exploration of the Crucial Genes and Molecular Mechanisms Mediating Atherosclerosis and Abnormal Endothelial Shear Stress." Disease Markers 2022 (August 12, 2022): 1–22. http://dx.doi.org/10.1155/2022/6306845.
Full textAbstract:
Background. Abnormal endothelial shear stress (ESS) is a significant risk factor for atherosclerosis (AS); however, the genes and pathways between ESS and AS are poorly understood. Here, we screened hub genes and potential regulatory targets linked to the progression of AS induced by abnormal ESS. Methods. The microarray data of ESS and AS were downloaded from the Gene Expression Omnibus (GEO) database. The coexpression modules related to shear stress and AS were identified with weighted gene coexpression network analysis (WGCNA). Coexpression genes in modules obtained from GSE28829 and GSE160611 were considered as SET1. The results were validated in validation set by differential gene analysis. The limma package in R was used to identify differentially expressed genes (DEGs). The common DEGs of GSE100927 and GSE103672 were regarded as SET2. Next, Gene Ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis was conducted. Protein-protein interaction (PPI) enrichment analysis was assembled, and hub genes were identified using MCODE and ClueGO in Cytoscape. ROC curve analyses were conducted to assess the ability of common hub genes to distinguish samples of atherosclerotic plaque from normal arterial. The expression of common hub gene was verified in ox-LDL-induced foam cells and GSE41571. Results. We identified three gene modules (the blue, tan, and cyan modules) related to AS and three shear stress-related modules (the brown, red, and pink modules). A total of 129 genes in SET1 and 476 genes in SET2 were identified. CCRL2, LGALS9, and PLCB2 were identified as common hub genes and validated in the GSE100927, GSE28829, and GSE41571. ROC analysis indicates the expression of CCRL2, LGALS9, and PLCB2 could effectively distinguish the atherosclerotic plaque and normal arterial. The expression level of CCRL2, LGALS9, and PLCB2 increases with the accumulation of lipid increased. Conclusion. We identified CCRL2, LGALS9, and PLCB2 as key genes associated with abnormal ESS and AS and may provide potential prevention and treatment target of AS induced by abnormal ESS.
40
Dziedzic, Angela, Agnieszka Morel, Elzbieta Miller, et al. "Oxidative Damage of Blood Platelets Correlates with the Degree of Psychophysical Disability in Secondary Progressive Multiple Sclerosis." Oxidative Medicine and Cellular Longevity 2020 (June 17, 2020): 1–12. http://dx.doi.org/10.1155/2020/2868014.
Full textAbstract:
The results of past research studies show that platelets are one of the main sources of reactive oxygen species (ROS) and reactive nitrogen species (RNS) to be found in the course of many pathological states. The aim of this study was to determine the level of oxidative/nitrative stress biomarkers in blood platelets obtained from multiple sclerosis (MS) patients (n=110) and to verify their correlation with the clinical parameters of the psychophysical disability of patients. The mitochondrial metabolism of platelets was assessed by measuring the intracellular production of ROS using the fluorescence method with DCFH-DA dye and by identification of changes in the mitochondrial membrane potential of platelets using the JC-1 dye. Moreover, we measured the mRNA expression for the gene encoding the cytochrome c oxidase subunit I (MTCO-1) and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) in platelets and megakaryocytes using the RT-qPCR method, as well as the concentration of NADPH oxidase (NOX-1) by the ELISA method. Our results proved an increased level of oxidative/nitrative damage of proteins (carbonyl groups, 3-nitrotyrosine) (p<0.0001) and decreased level of -SH in MS (p<0.0001) and also a pronounced correlation between these biomarkers and parameters assessed by the Expanded Disability Status Scale and the Beck’s Depression Inventory. The application of fluorescence methods showed mitochondrial membrane potential disruption (p<0.001) and higher production of ROS in platelets from MS compared to control (p<0.0001). Our research has also confirmed the impairment of red-ox metabolism in MS, which was achieved by increasing the relative mRNA expression in platelets for the genes studied (2-fold increase for the MTCO-1 gene and 1.5-fold increase in GAPDH gene, p<0.05), as well as the augmented concentration of NOX-1 compared to control (p<0.0001). Our results indicate that the oxidative/nitrative damage of platelets is implicated in the pathophysiology of MS, which reflects the status of the disease.
41
BOICHYSHYN, Lidiya, Mariya LOPACHAK, Bogdan KOTUR, Oksana HERTSYK, and Tetyana BODNAR. "INVESTIGATION OF THE INTERFACE BETWEEN THE AMORPHOUS ELECTRODE Co75.5Fe4.6Si6.0B16.7 / AQUA SOLUTION NaCl BY ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY." Proceedings of the Shevchenko Scientific Society. Series Сhemical Sciences 2024, no. 75 (2024): 7–16. http://dx.doi.org/10.37827/ntsh.chem.2024.75.007.
Full textAbstract:
Amorphous metal alloys (AMА) based on cobalt are promising materials with near-zero magnetostriction. In recent years, AMА have been used as sensors and biomaterials for the internal transport of drugs, mainly for oncological diseases. Therefore, it is necessary to investigate in detail the processes of their dissolution and passivation in aggressive environments, in particular, in a 3% aqueous solution of NaCl, in which the solubility of oxygen is the greatest. It is necessary to build up a homogeneous oxide-hydroxide film on AMC, which would be a substrate for organic immobilizers of medical preparations. In aggressive environments, these alloys are subject to corrosion due to loose and defective protective layers formed on their surface. The purpose of the work was to study the phase separation boundary of amorphous electrode Co75.5Fe4.6Si6.0B16.7/NaCl aqueous solution by electrochemical impedance spectroscopy and determine the thickness of oxide/hydroxide layers. By the potentiometric and cyclic voltametry methods the corrosive processes of the amorphous metallic alloys Co75.5Fe4.6Si6.0B16.7 / 3% aqua solution NaCl interface has been investigated. It is shown that contribute appreciable passivation and 2.510–3 % KMnO4 addition to the 3% aqua solution NaCl promote the significant passivation of electrode what is marked by Еcorr. shift to anodic side and icorr. shows the about 10–7 А/cm2 value. The surface protective layers on AMA electrode, formed during polarization processes at –290 and –550 mV potentials in 3% aqua solution NaCl before and after 12 hours preimmersion in this solution as well as in this solution with 2.510–3 % KMnO4 addition were studied by means of electrochemical impedance spectroscopy method. The model equivalent electric circuits for AMA (passivity layer) / 3% aqua solution NaCl system were fitted. It is shown, that at –550 mV potential the equivalent electric circuits consist of the ox/red reaction resistance and oxide layer capacitance. The low impedance parameters at corrosive protection condition relating with multiplayer surface structure, which consists thin and compact inside layer and more porous outside one, are confirmed by SEM results.
42
Tadesse, Tesfaye, Getahun Degu, Ermias Shonga, Shiferaw Mekonen, Temesgene Addis, and Birhanu Yakob. "Current status, Potentials and challenges of Cassava production, processing, marketing and utilization: Evidence from Southern Ethiopia." Greener Journal of Agricultural Sciences 3, no. 4 (2013): 262–70. https://doi.org/10.15580/GJAS.2013.4.021313457.
Full textAbstract:
The paper provides primary information on the status, potentials and challenges of cassava production, utilization and marketing major cassava growing areas of southern Ethiopia. The study was conducted in five purposively selected sample Woredas / districts of SNNPR, Amaro, Kindokoyesha, Gofa, Arbamench Zuria and Konso based on cassava production potential and accessibility in consultation with Zonal and Woreda bureau of agriculture. A total of 200 sample respondents, 40 from each district were selected and interviewed using structured questionnaire. The study also considered information from secondary sources The data collected from the sample respondents and secondary sources were analyzed using descriptive statistic and use of statistical software package SPSS, 2011. The result indicated that cassava stands first in both production and productivity followed by sweet potato and maize in belge (short rainy season) while during Meher (long rainy season) the reverse was observed. The mean land holding (ha) of a household in the study areas were 0.93, 0.46, 1.22, 0.56 and 0.73 for Amaro, Kindo Koyisha, Demba Gofa, Konso and Arbamench respectively. The overall mean of land holding in the study area was 0.78 ha. The mean land holding of sample household allocated for cassava production in the study area was 0.20 ha. Area allocated for improved and local cultivar cassava average for the study area is 0.19 and 0.30 ha respectively. Land preparation for all crops under cassava farming system was carried out by using outdated and labor intensive tools such as hoe (66%) and ox plough (33%) of sample farmer’s average for the five districts. Income generated from cassava was by selling fresh cassava root from the farm and/or the nearby local market. In the same way, processed cassava products especially cassava chips and flours were consumed and sold in the study area. The quality of the planting material that the farmers were using had average quality as to 52% of sampled farmers and 36% using high quality planting materials. Most of the farmers obtain planting materials from their own savings but few had gotten from relatives, friends and other sources. The two improved varieties introduced to the farmers were kello (44/72 red) and Qulle (104/72 Nigerian red). The adoption rate for the improved varieties by the sampled farmers in the study area in average was only 30%. There were some constraints in cassava production areas. Among which insect pest invasion, lack of early maturing variety, shortage of land, low moisture stress and low market demand and/or price were among the most important ones. Therefore, labor saving farm implements, management of cassava scale insects and existing post harvest processing equipments needs to be improved. Development and demonstration of early maturing cassava varieties is also a pertinent area to contribute to solve the existing problems of cassava producing areas.
43
Yang, Qinqin, Yanyun Xu, Liye Shen, et al. "Guanxinning Tablet Attenuates Coronary Atherosclerosis via Regulating the Gut Microbiota and Their Metabolites in Tibetan Minipigs Induced by a High-Fat Diet." Journal of Immunology Research 2022 (July 28, 2022): 1–23. http://dx.doi.org/10.1155/2022/7128230.
Full textAbstract:
Coronary atherosclerosis (CA) is a chronic and evolving inflammatory disease characterized by the build-up of atherosclerotic plaque in the wall of coronary arteries. Guanxinning tablet (GXNT) is a novel Chinese medicine formula, which has been clinically used to treat coronary heart disease for many years. However, the potential mechanism for treating CA remains unclear. Thus, the study was aimed at investigating the therapeutic effect of GXNT on CA and further explore the underlying mechanisms from the perspective of gut microbiota. Following the establishment of a CA model in Tibetan minipigs, GXNT was orally administrated. We simultaneously detected blood lipid levels, observed ventricular function using ultrasound examination, measured platelet aggregation, and checked changes in inflammatory factors, oxidative stress factors, and vascular endothelial injury-related indexes applying ELISA assays. Histopathological changes of coronary artery tissue were subsequently evaluated using Sudan IV staining, HE staining, Oil red “O” staining, and immunohistochemistry assays. Finally, alterations of the gut microbiota and microbial metabolites were detected using metagenomic sequencing and targeted metabolomics, respectively. The results have suggested that GXNT could regulate dyslipidemia, improve heart function, and inhibit the levels of ox-LDL, CRP, TNF-α, IL-1β, SOD, MDA, vWF, and ET-1, as well as platelet aggregation. Additionally, histopathological findings revealed that GXNT could reduce lipid deposition, alleviate AS lesions, and restrain the expressions of NF-κB, TNF-α, and MMP-9. Furthermore, the composition of the gut microbiota was altered. Specifically, GXNT could upregulate the relative abundance of Prevotellaceae and Prevotella and downregulate the abundance of Proteobacteria, Enterobacteriaceae, and Escherichia. As for microbial metabolites, GXNT could increase fecal propionic acid, butyric acid, and LCA-3S and decrease fecal TMA-related metabolites, CDCA, and serum TMAO. In sum, the results showed that GXNT had a satisfactory anti-CA effect, and the mechanism was closely associated with modulating gut microbiota and related metabolites.
44
Jakubowicz, Piotr, Teresa Steliga, Dorota Kluk, and Katarzyna Wojtowicz. "Określenie możliwości zastosowania symulacji komputerowej do przewidywania kierunku przebiegu reakcji podczas zatłaczania wód złożowych." Nafta-Gaz 77, no. 4 (2021): 244–54. http://dx.doi.org/10.18668/ng.2021.04.04.
Full textAbstract:
Currently, practically the entire volume of water extracted in the process of hydrocarbon exploitation is utilized by injection into deposits. Changes in the physico-chemical parameters (pH, red-ox potential, temperature, etc.) of the water during extraction and the contact of the injected water with the native water and deposit rock may result in the precipitation of sediment particles and suspensions. It causes clogging of the near-wellbore zone and limits the amount of water that can be injected with the injection well. Due to the high complexity of the system: the injected water–reservoir rock, and a wide range of interactions between individual components, the analytical data does not always allow for the correct interpretation of the course of the processes and determination of their impact on the permeability of the near-well zone. Using the results of physico-chemical analyses of the composition of separator water samples with different properties – two samples with low mineralization S1K (575 mg/dm3) and S4K (551 mg/dm3), a sample with high S2K (306 428 mg/dm3) and medium mineralization S3K (79 858 mg/dm3) – calculations were performed using the PHREEQC program for the three databases: phreeqc.dat, wateq4f.dat and pitzer.dat. It was found that in the case of low mineralization waters, the results obtained in each of the databases are similar for the minerals present in all the databases. However, in the case of solutions with high mineralization, there are significant differences in the obtained results. The calculated solubility indices allowed to determine the direction of the precipitation/dissolution reaction of individual minerals in the deposit and to indicate the risks, mainly with the formation of iron compounds deposits, for the operation of the injection well. Laboratory tests of water mixing were also carried out. The formation of iron oxide deposits that could damage the near-well zone was observed, which confirmed the results obtained during computer simulations.
45
Bahre, Gidey, Tadele Hunde, Mekonen Tirfu, Rishi Pal, and R. C. Saini. "Fabrication of TiO2-Carbon Paste Modified Electrochemical Sensor for 4-Aminophenol in Pharmaceutical Samples." Journal of Surface Science and Technology 32, no. 1-2 (2016): 58. http://dx.doi.org/10.18311/jsst/2016/6603.
Full textAbstract:
In this study the electrochemical behavior of 4-aminophenol at titanium dioxide modified carbon paste electrode was investigated using cyclic voltammetry. The working parameters for both, cyclic- and square wave- voltametric studies have been optimized using 5.0 mM 4-aminophenol (4-APOH) in 0.1 M NaH<sub>2</sub>PO<sub>4</sub>.2H<sub>2</sub>O buffer solution. The modified rather than unmodified carbon paste sensor, in neutral medium, has exhibited strong electro-catalytic activity towards the redox characteristics of 4-aminophenol by showing two-fold peak current enhancement and 174 mV peak potential shift towards negative direction. The red-ox peak current ratio (I <sub>pa</sub>/I <sub>pc</sub> = 1.6) suggested high accumulation efficiency of 4-APOH at the modified sensor. The redox process is quasi reversible and involves the transference of 2e<sup>-</sup>s and 2H<sup>+</sup>s followed by diffusion controlled, non-adsorptive behavior of 4-APOH on the surface of sensor at the interface. Further, the electro-catalytic behavior of the modified sensor has been exploited for quantitative determination of 4-aminophenol in pharmaceutical samples using square wave voltammetry. Under optimal experimental conditions, there was a linear relationship between peak current and concentration in the range 2.5 × 10<sup>-5</sup> to 2.0 × 10<sup>-4</sup> M with a correlation coefficient of 0.998 and limit of detection 1.38 × 10<sup>-8</sup> M. The method was successfully applied for the quantitative determination of 4-aminophenol in pharmaceutical formulations against the commercial drugs <em>viz</em>., <em>PANADOL</em>, and <em>Paracetamol</em> at recovery level of 100 ± 1.7 %.
46
Kawada, Tatsuya, Satoshi Watanabe, Riyan Achmad Budiman, et al. "(High-Temperature Energy, Materials, & Processes Division Subhash Singhal Award) From Electrochemical to Mechanical Modeling of SOFCs and Their Experimental Validation." ECS Meeting Abstracts MA2023-01, no. 54 (2023): 7. http://dx.doi.org/10.1149/ma2023-01547mtgabs.
Full textAbstract:
Due to the asymmetric structure with multiple materials, SOFCs are subjected to various modes of mechanical stress, resulting in a risk of failure. Of particular importance are thermal and chemical strains, which depend on the micro- and macroscopic distribution of electrochemical reaction sites. Therefore, SOFC modeling must include electrochemistry, mass and charge transport, thermo-fluid dynamics, and structural analysis. In addition, appropriate experiments must be performed to validate the modeling results. This research group is working to develop a comprehensive environment for modeling and validation in order to evaluate the mechanical reliability of SOFCs. Electrochemical modeling of cathode was made based on the defect chemistry and mass transport of (La,Sr)CoO3 (LSC) and (La,Sr)(Co,Fe)O3 (LSCF). An empirical equation for the surface reaction of the porous electrode was determined by electrochemical analysis of a dense film electrode taking into account the difference between the dense film and porous electrodes [1]. Anode reaction rate on a unit length of triple phase boundary of Ni-YSZ-gas was determined using circular Ni model electrodes of various size [2]. Evaluation of 3D oxygen potential distribution inside the constituent oxides was made using an in-house code called SIMUDEL where mixed ionic/electronic conduction and oxygen nonstoichiometry were taken into consideration [3,4]. It was combined with commercial software to make structural analysis. Mechanical properties used for calculation were obtained from measurements by the resonance method and the small punch method or collected from the literature. Non-linear stress-strain behaviors were observed with Ni-YSZ cermet [5] and inelastic behaviors were found in most nonstoichiometric oxide materials. Large ferro-elasticity emerged in the LSC and LSCF [6] and in Sc stabilized ZrO2 electrolyte at elevated temperatures. Chemical strain in vacancy formation was formulated with a linear function of the defect concentration as an independent factor from the thermal expansion. In the structural analysis, it was treated as the additional temperature change of the local material. Volume change of Ni-YSZ cermet on red-ox operation was a difficult factor to formulate because of its complex dependence on composition, temperature, and atmosphere. As expected, Ni-YSZ showed expansion when oxidized, but under certain conditions at an intermediate temperature range, it rather contracted on oxidation [7]. In reality, the calculated stress distribution does not always match the actual behavior of the cell since there often are unconsidered factors. Thus, experimental validation is essential. For this purpose, we have developed methods for in-situ or operando measurements of cell shape and the residual stress. Long-focus laser profilometer was used to measure the warping of a planar cell during heating, operating, and cooling operations. For the change in the diameter of a tubular cell, the laser projection type dimension meter was employed. Residual stress measurements were made with a handy X-ray analyzer (μ-X360s, Pulstec Industrial. Co. Ltd.) combined with a newly developed one- or two-chamber cell holder [8,9]. Anode-supported cells from multiple sources were analyzed, showing different stress histories in red-ox operations depending on the microstructure of the anode support layer. Currently, we are developing a protocol for testing robustness of planar SOFCs. Here, temperature distribution is intentionally applied on a cell with segmented heater allays on the top and the bottom of the cell. Severe condition tests will be performed, and the results will be analyzed with the above-mentioned simulation. Acknowledgement This study was supported by the New Energy and Industrial Technology Development Organization (NEDO) . [1] T. Kawada, Current Opinion in Electrochemistry, 21, 274-282 (2020) DOI: 10.1016/j.coelec.2020.03.016 [2] M. Takeda, Master’s thesis, Graduate School of Environmental Studies, Tohoku University (2016) : M. Takeda, et al. Submitted to J. Electrochem. Soc. [3] K. Terada, et. al., ECS Trans. 35(2 part2), 923-933 DOI: 10.1149/1.3570073 [4] M. Sato, et. al., Trans. Jpn. Soc. Comp. Eng. Sci. 2017, 14 (2017) DOI: 10.11421/jsces.2017.20170004 [5] S. Watanabe et al., J. Mater. Sci. 55, 8679-8693 (2020) DOI: 10.1007/s10853-020-04624-4 [6] Y. Kimura et al., J. Electrochem. Soc. 161(11), F3079- F3083 (2014) DOI: 10.1149/2.0131411jes [7] Y. Morishita et al. , ECS Trans., 91(1) 1979-1984 (2019). DOI: 10.1149/09101.1979ecst [8] K. Yashiro et al., submitted to J. Power Sources [9] K. Oshima et al.,ECS Trans. 103(1), 1251-1260 (2021) DOI: 10.1149/10301.1251ecst
47
Tokarev, Oleg V., Vladimir A. Volkovich, Alexander A. Ryzhov, and Dmitry S. Maltsev. "(Digital Presentation) Electrode Potentials of Gallium in Fused Alkali Chlorides." ECS Transactions 109, no. 14 (2022): 197–204. http://dx.doi.org/10.1149/10914.0197ecst.
Full textAbstract:
Electrochemical properties of gallium were investigated in 3LiCl–2KCl and 6NaCl–9KCl–5CsCl eutectic based melts at 430–700 and 500–760 oC, respectively. Zero current potentiometry was employed for studying the electrochemical behavior of gallium. Gallium ions in two oxidation states, Ga(III) and Ga(I), were present in the melt in contact with the metal. Formal standard electrode and red-ox potentials of gallium, E*(Ga/Ga(III), E*Ga/Ga(I) and E*Ga(I)/Ga(III), in these molten alkali chloride mixtures were determined.
48
Şimşek, Kaan, and Sarp Kaya. "Investigating Co and Fe Single-Atom (SA) Decorated NS-Doped Reduced Graphene Oxide (Co SA/NS-rGO, Fe SA/NS-rGO) Catalysts for NOx - to NH3 Pulsed Electroreduction." ECS Meeting Abstracts MA2024-01, no. 39 (2024): 2325. http://dx.doi.org/10.1149/ma2024-01392325mtgabs.
Full textAbstract:
Electrochemical NH3 production has attracted much attention due to its potential to compensate for and supplement the Haber-Bosch process that produces hundreds of billions of kg of NH3 annually.1 One of the proposed electrochemical pathways to produce NH3 is the N2 reduction reaction. However, this reaction suffers from a high bond dissociation energy of 945 kJ mol−1, low NH3 Faradaic efficiency (F.E.) at high overpotentials, and NH3 quantification problems, limiting the extent of its applications.2,3 On the other hand, other N-containing species, NO3 - and NO2 -, that are commonly found in sewages and agricultural water, hold great potential for electrochemical NH3 production owing to their high NH3 yield rate and F.E. as well as building a self-sustaining NH3 production cycle working tandem with denitrification processes.1,4 In this study, we investigated Co and Fe single-atom (SA) decorated NS-doped reduced graphene oxide (Co SA/NS-rGO and Fe SA/NS-rGO) catalysts for nitrate reduction reaction (NO3RR) and nitrite reduction reaction (NO2RR). Both materials have defect-rich properties owing to preserving the nature of doped graphene materials even after the metal incorporation. The presence of the layered structure of graphene and homogenous distribution of Fe and Co SAs in the doped graphene basal plane is shown through High-Resolution Scanning Transmission Electron Microscopy (HR-STEM) measurements. In addition to the Co and Fe SAs on the NS-rGO planes, SEM and X-ray Photoelectron Spectroscopy (XPS) investigations demonstrated that CoS and FeS could be simultaneously formed. We performed NO3RR and NO2RR experiments in 0.1 M KOH + 0.1 M KNO3 and 0.1 M KOH + 0.1 M KNO2 electrolytes with constant Ar purging in a glass H-Cell with a Nafion proton exchange membrane. We obtained NH3 with 65% F.E. at -0.4 V and a maximum of 2 mol s-1 molM -1 yield rate using Co SA/NS-rGO catalyst while with 60% F.E. at -0.5 V and 2.3 mol s-1 molM -1 yield rate using Fe SA/NS-rGO catalyst for NO3RR. Furthermore, the ∼10% NO2 - F.E. that is obtained for NO3RR experiments at -0.3 V and a significant increase in NH3 F.E. after -0.3 V for NO2RR indicates that NO3 - to NO2 - reduction takes place at this potential and our catalysts follow a two-step electron transfer mechanism. Moreover, linear sweep voltammetry (LSV) measurements indicated an onset potential of -0.4 V and -0.5 V for Co SA/NS-rGO and Fe SA/NS-rGO, respectively, for the NO3RR which are in excellent agreement with NO3RR F.E. results. We demonstrate that after prereduction at high negative potentials and with optimizations in experimental conditions, one can obtain >80% NH3 F.E. for NO3RR. To further increase the NH3 yield, three different pulsed electroreduction studies such as applying a potential at (1) the open circuit potential (OCP), (2) NO2 - reduction potential, (3) Co2+ or Fe2+ red-ox potentials and NH3 reduction potentials for 1-5 s intervals were performed. On Co SA/NS-rGO, an increased NH3 F.E. of ∼100% at -0.4 V was obtained under pulsed conditions. Also, by modulating NO3 - to NO2 - conversion to more negative potentials by pulsed electroreduction, significantly higher NH3 F.E. values were obtained for both catalysts. The higher NH3 F.E. and lower overpotential of Co SA/NS-rGO compared to Fe SA/NS-rGO could be attributed to the CoS formation that is more stable than FeS. References: (1) Erisman, J. W.; Sutton, M. A.; Galloway, J.; Klimont, Z.; Winiwarter, W. How a Century of Ammonia Synthesis Changed the World. Nature Geosci 2008, 1 (10), 636–639. https://doi.org/10.1038/ngeo325. (2) Suryanto, B. H. R.; Du, H.-L.; Wang, D.; Chen, J.; Simonov, A. N.; MacFarlane, D. R. Challenges and Prospects in the Catalysis of Electroreduction of Nitrogen to Ammonia. Nat Catal 2019, 2 (4), 290–296. https://doi.org/10.1038/s41929-019-0252-4. (3) Andersen, S. Z.; Čolić, V.; Yang, S.; Schwalbe, J. A.; Nielander, A. C.; McEnaney, J. M.; Enemark-Rasmussen, K.; Baker, J. G.; Singh, A. R.; Rohr, B. A.; Statt, M. J.; Blair, S. J.; Mezzavilla, S.; Kibsgaard, J.; Vesborg, P. C. K.; Cargnello, M.; Bent, S. F.; Jaramillo, T. F.; Stephens, I. E. L.; Nørskov, J. K.; Chorkendorff, I. A Rigorous Electrochemical Ammonia Synthesis Protocol with Quantitative Isotope Measurements. Nature 2019, 570 (7762), 504–508. https://doi.org/10.1038/s41586-019-1260-x. (4) Duca, M.; Koper, M. T. M. Powering Denitrification: The Perspectives of Electrocatalytic Nitrate Reduction. Energy Environ. Sci. 2012, 5 (12), 9726–9742. https://doi.org/10.1039/C2EE23062C.
49
Monzón Manzano, Elena, Ihosvany Fernandez-Bello, Raul Justo Sanz, et al. "Prothrombotic State, Platelet Activation and Netosis in Systemic Lupus Erythematosus." Blood 134, Supplement_1 (2019): 1141. http://dx.doi.org/10.1182/blood-2019-127991.
Full textAbstract:
Introduction: Systemic lupus erythematosus (SLE) is a chronic autoimmune disease of unknown origin characterized by a hypercoagulable state and a high mortality rate. Mechanisms that cause the accelerated deterioration of cardiovascular health in SLE are unknown. Objectives: to characterize the prothrombotic state in SLE patients by global coagulation assays and the contribution of platelets, endothelial damage, microparticles and neutrophil extracellular traps (NETs) in their prothombotic profile. Material and methods: 72 patients and 90 healthy controls were recruited. Patients were classified according to clinical characteristics in: 32 with lupus (SLE group), 29 with SLE and antiphospholipid antibodies (aFL, SLE+aFL group) and 12 who met the criteria for SLE and antiphospholipid syndrome (APS, SLE+APS group). Experimental protocol was approved by La Paz University Hospital Ethics Committee. Venous blood collected in BD sodium citrate tubes (3.2%) was centrifuged at 150 g for 20 min at 23ºC to obtain platelet-rich plasma (PRP). PPP was obtained by centrifugation at 1500 g for 15 min at 23ºC. To obtain neutrophils, whole blood was centrifuged to 1600 rpm 25 min using a Ficoll gradient and red cells were lysed. Rotational thromboelastometry (ROTEM®) was performed in naTEM condition. Clotting time (CT, time from start of measurement until initiation of clotting [in seconds]); alpha angle (tangent to the curve at 2-mm amplitude [in degrees]), Ax (clot firmness at time x, [in mm]) and maximum clot firmness (MCF, [in mm]) were recorded. Procoagulant activity associated to microparticle's content of tissue factor was determined in PPP by Calibrated Automated Thrombogram (CAT) using MP-reagent (4 mM phospholipids, Diagnostica Stago, Spain). We evaluated the endogenous thrombin potential (ETP, the total amount of thrombin generated over time); the lag time (the time to the beginning of the explosive burst of thrombin generation); the peak height of the curve (the maximum thrombin concentration produced) and the time to the peak. Thrombin generation associated to NETs was also measured by CAT. Neutrophils from healthy controls or from LES patients were stimulated with 100 nM PMA in RPMI medium during 45 min at 37º and then cocultivated with PRP adjusted to 105 platelets/µL. NETs formation was verified by fluorescent microscopy performed with DAPI and an anti-myeloperoxidase antibody. Plasma levels of LDL-ox, E-Selectin and PAI-1 were determined by Elisa (R&D Systems, MN, USA and Affymetrix eBioscience, Vienna, Austria, respectively). Platelet activation was analysed by flow cytometry (FCM, FACScan, BD Biosciences). Fibrinogen receptor activation was evaluated through PAC1-FITC binding and release of granule's content was assessed with monoclonal antibodies (mAbs) anti-CD63 and anti P-selectin in quiescent and 100 µM TRAP and 10 µM ADP stimulated platelets. Data were analysed with Graphpad prism and p ≤0.05 was stablished as statistical significance. Results: PAI-1 plasma level was increased in all patient's groups, whereas LDL-ox and E-selectin showed no differences with control cohort (Fig.1). ROTEM demonstrated a procoagulant profile in SLE and SLE+aPL but not in SLE+APS group (Fig. 2). PAI-1 levels correlated with several ROTEM parameters (Table 1). SLE patients and SLE+aFL showed a basal platelet activation. Moreover, SLE group exposed more P-selectin and CD63 than controls (Fig.3). Regarding thrombin generation associated to tissue-factor content of microparticles, no differences were observed between SLE patients and healthy controls. On the other hand, SLE patients had an increased peak of thrombin generation related to NETs formation (control group: 170.3± 58.0, SLE patients: 230.6±39.3, p=0.019). Conclusions: ROTEM® detected a hypercoagulable state in SLE and SLE+aPL patients. The hypercoagulable state might be linked to increased PAI-1 plasma levels and basal platelet activation in SLE and SLE+aPL groups. Moreover, neutrophils from SLE patients seemed to present a basal activation that induced a NETs-related procoagulant state in these patients. SLE+APS patients did not show a hypercoagulable state perhaps because of the presence of lupus anticoagulant and/or to therapeutic treatment of these patients. This work was supported by grants from the FIS-FONDOS FEDER (PI15/01457, NB). NVB holds a Miguel Servet tenure track grant from FIS-FONDOS FEDER (CP14/00024). Disclosures Fernandez-Bello: Novartis, Pfizer, ROCHE, Stago: Speakers Bureau. Robles:ABBVIE, SANDOZ FARMACEUTICA: Speakers Bureau. Álvarez Roman:Sobi: Consultancy, Speakers Bureau; CSL Behring: Consultancy, Speakers Bureau; Roche: Consultancy, Speakers Bureau; Pfizer: Consultancy, Speakers Bureau; Bayer: Consultancy, Speakers Bureau; Novartis: Consultancy, Speakers Bureau; Amgen: Consultancy, Speakers Bureau; Takeda: Research Funding; NovoNordisk: Consultancy, Speakers Bureau. Canales:Celgene: Honoraria; Gilead: Honoraria; Novartis: Honoraria; Janssen: Honoraria, Speakers Bureau; Sandoz: Honoraria; iQone: Honoraria; Takeda: Speakers Bureau; SOBI: Research Funding; Karyopharm: Honoraria; F. Hoffmann-La Roche Ltd: Honoraria, Speakers Bureau. Jimenez-Yuste:Bayer, CSL Behring, Grifols, Novo Nordisk, Octapharma, Pfizer, Roche, Sobi, Shire: Consultancy, Honoraria, Other: reimbursement for attending symposia/congresses , Research Funding, Speakers Bureau. Butta:Novartis: Consultancy; Roche, Pfizer: Speakers Bureau.
50
Eichinger, Sabine, Paul A. Kyrle, Michael Kammer, Lisbeth Eischer, and Christoph Binder. "Naturally Occurring Autoantibodies to Oxidation-Specific Epitopes in Patients with Venous Thromboembolism." Blood 124, no. 21 (2014): 2861. http://dx.doi.org/10.1182/blood.v124.21.2861.2861.
Full textAbstract:
Abstract Background: Naturally occurring IgM autoantibodies (NAb) recognize oxidation-specific epitopes which are altered self structures on apoptotic cells, oxidized LDL, or vessel wall proteins. Oxidation-specific epitopes are proinflammatory antigens and potential markers for chronic inflammatory conditions. The risk of venous thromboembolism (VTE) is associated with (pro)inflammatory states such as dyslipoproteinemia, obesity or cancer. We hypothesize that natural antibodies may target epitopes which are also involved in the pathogenesis of VTE. In pursuing a “proof of concept”, we studied Nab in patients with a high venous thrombotic risk and evaluated their association with the risk of recurrent VTE. Methods: We determined Nab levels in 663 patients with a first unprovoked deep vein thrombosis and/or pulmonary embolism who were prospectively followed after discontinuation of anticoagulation in the Austrian Study on Recurrent Venous Thromboembolism, a multicentre cohort study. We excluded those with coagulation inhibitor deficiencies, lupus anticoagulant, cancer, pregnancy, long-term antithrombotic therapy, or homozygosity/double heterozygosity for factor V Leiden and/or the prothrombin mutation. Study end point was recurrent VTE. Nab target different oxidation-specific epitopes including phosphorylcholine-containing oxidized phospholipids which were generated by oxidation of low density lipoproteins (LDL) with CuSO4. Levels of IgM against oxidized (Ox) LDL were determined in venous blood drawn three weeks after discontinuation of anticoagulants by chemiluminescent enzyme linked immunoabsorbent assay and expressed as relative light units (RLU)/100ms. To determine the effect of anti-OxLDL IgM on the recurrence risk, models for time-to-event-data were used. Their direct effect on the recurrence risk was estimated by a cause-specific Cox proportional-hazards model, followed by a Fine-Gray model to account for competing events (death, restart of antithrombotics) and expressed by subdistribution hazard ratios (SHR). Anti-OxLDL IgM levels are given as median (25th, 75th percentiles). Results: Levels of anti-OxLDL IgM in patients with a first unprovoked VTE were 20.17 RLU/100ms (12.26, 34.72). Levels did not correlate with either age (rs=-0.16) or BMI (rs=-0.16). Levels correlated with sex [higher in women; 24.24 (14.6, 40.0) vs. 16.76 (10.46, 27.9) RLU/100ms, p<0.001]. 151 (22.8%) of 663 patients (mean age 48 years, 54% women) had recurrence during a median of 67 months. Anti-OxLDL IgM levels were higher in patients without recurrence [20.84 (12.32, 36.85) vs. 17.60 (11.97, 26.93) RLU/100ms, p=0.02]. For each doubling of anti-OxLDL IgM levels, the SHR of recurrence was 0.85 (95% CI 0.74-0.98; p = 0.02) and was 0.95 (0.82-1.1; p=0.5) after adjustment for sex. Patients with anti-OxLDL IgM levels within the second tercile (14.6 - <28.64 RLU/100ms) had a similar recurrence risk as patients with levels within the first tercile (<14.60 RLU/100ms) (SHR 0.93, 95% CI 0.65–1.33, p=0.7). The recurrence risk was significantly lower in patients with anti-OxLDL IgM levels within the third tercile (>28.64 RLU/100ms) (SHR 0.58, 95% CI 0.38–0.87, p<0.01). After adjustment for sex, the recurrence risk was still lower among patients with high anti-OxLDL IgM (SHR 0.75, 95% CI 0.49–1.14, p=0.2) but without statistical significance. We stratified patients according to an anti-OxLDL IgM level corresponding to the 60th percentile (14.6 RLU/100ms). The cumulative probability of recurrence after 5 years in patients with anti-OxLDL IGM > 60th percentile was 12.3% (8.5-16.9%) and was 20.3% (16.4-24.6%) among those with lower levels (p<0.001) (Figure). The corresponding SHR was 0.55 (0.38-0.78; p <0.001) for higher anti-OxLDL IgM and was 0.67 (95% CI 0.47-0.96; p=0.03) after adjustment for sex. Conclusions: An association exists between anti-OxLDL IgM and VTE recurrence which is consistent with a protective function of NAb via their ability to bind proinflammatory oxidation-specific epitopes. Figure: Cumulative recurrence rate in patients with VTE according to anti-OxLDL IgM levels below (blue line) or above (red line) the 60th percentile. Dotted lines are 95% CI. Figure:. Cumulative recurrence rate in patients with VTE according to anti-OxLDL IgM levels below (blue line) or above (red line) the 60th percentile. Dotted lines are 95% CI. Disclosures No relevant conflicts of interest to declare.