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1
Niu, Wei, Zhong An Jiang, and Ju Shi Chen. "Research on Optimal Formula of Dustfall Agent to Remove Blasting Smoke." Advanced Materials Research 534 (June 2012): 298–303. http://dx.doi.org/10.4028/www.scientific.net/amr.534.298.
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In order to reduce dust produced during the blasting, effective measures according to smoke components and properties are required to be taken. The experiment adopted a number of base materials and surface-active agents to reduce the dust in smoke. Besides, corresponding additives were adopted to reduce poisonous and harmful gases during the blasting. Experiments focused on wettability and surface tension, using contrast experiment to determine optimal base material and surface-active agent, and also studied the influence of additives on their performance. The experimental results suggested that： sodium chloride was the optimal base material, sodium dodecyl benzene sulfonate was the optimal surface-active agent, and copper sulphate and ammonium chloride as additives had almost no influence on performance of surface-active agent and base material. Therefore, adding this dustfall agent to the water bag during the blasting can effectively reduce the concentration of smoke.
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Cui, Wei Lin, Wu Ju Xu, and Ling Jian Song. "The Influence of Different Kinds of Surfactants on Rheology in Polymer/Surfactant Complex Flooding." Applied Mechanics and Materials 437 (October 2013): 1089–92. http://dx.doi.org/10.4028/www.scientific.net/amm.437.1089.
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Because of alkaline declining the sweep efficiency, causing scale formation problem in the reservoir and the well bottom and the tubular pipes, so polymer/surfactant compound flooding technology is the emphasis in the research of enhanced recovery. So the articles study the regulation of different kinds of surface active agents at different temperature by MARS Rheometer. The testing result showed that the variation of viscocity under the interaction between the surface active agent and association polymer according to “three stage” model .The linear viscoelastic region of stress decrease when different surface active agents are put into polymer liquor, and the higher frequency, the better elasticity of polymer liquor. The hydrophobic association between the surface active agents and polymer decrease with a higher temperature, but the ionic surfactant is aggravate. The systematic study of binary system rheology can contribute to correctly understand and apply binary system.
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Du, Bing Xin, and Kun Huang. "The Research on Comprehensive Utilization of Phosphogypsum." Advanced Materials Research 850-851 (December 2013): 1368–71. http://dx.doi.org/10.4028/www.scientific.net/amr.850-851.1368.
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Introduce several examples of surface active agents used in wet-process phosphoric acid (WPPA) to show its effect on the quality of phosphogypsum. Summarized both domestic and foreign methods of comprehensive utilization of phosphogypsum, such as being made into calcium sulfate whisker, building materials, soil improvement agent, chemical raw materials and etc. Some problems of resources utilization of phosphogypsum in China are summarized, and reasonable suggestions are put forward.
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Kupnik, Kaja, Mateja Primožič, Vanja Kokol, and Maja Leitgeb. "Nanocellulose in Drug Delivery and Antimicrobially Active Materials." Polymers 12, no. 12 (November 27, 2020): 2825. http://dx.doi.org/10.3390/polym12122825.
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In recent years, nanocellulose (NC) has also attracted a great deal of attention in drug delivery systems due to its unique physical properties, specific surface area, low risk of cytotoxicity, and excellent biological properties. This review is focused on nanocellulose based systems acting as carriers to be used in drug or antimicrobial delivery by providing different but controlled and sustained release of drugs or antimicrobial agents, respectively, thus showing potential for different routes of applications and administration. Microorganisms are increasingly resistant to antibiotics, and because, generally, the used metal or metal oxide nanoparticles at some concentration have toxic effects, more research has focused on finding biocompatible antimicrobial agents that have been obtained from natural sources. Our review contains the latest research from the last five years that tested nanocellulose-based materials in the field of drug delivery and antimicrobial activity.
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Olkowska, Ewa, Marek Ruman, Magdalena Drąg-Śmigalska, and Żaneta Polkowska. "Selected anionic and cationic surface active agents: case study on the Kłodnica sediments." Limnological Review 17, no. 1 (March 1, 2017): 11–21. http://dx.doi.org/10.1515/limre-2017-0002.
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AbstractSurface active agents (surfactants) are a group of chemical compounds, which are used as ingredients of detergents, cleaning products, cosmetics and functional products. After use, wastes containing surfactants or their degradation products are discharged to wastewater treatment plants or directly into surface waters. Due to their specific properties of SAAs, compounds are able to migrate between different environmental compartments such as soil, sediment, water or even living organisms and accumulate there. Surfactants can have a harmful effect on living organisms. They can connect with bioactive molecules and modify their function. Additionally, they have the ability to migrate into cells and cause their damage or death. For these reasons investigation of individual surfactants should be conducted. The presented research has been undertaken to obtain information about SAA contamination of sediment from the River Kłodnica catchment caused by selected anionic (linear alkylbenzene sulfonates (LAS C10-C13)) and cationic (alkylbenzyldimethylammonium (BDMA-C12-16), alkyl trimethyl ammonium (DTMA), hexadecyl piridinium chloride (HP) chlorides) surfactants. This river flows through an area of the Upper Silesia Industrial Region where various companies and other institutions (e.g. coal mining, power plants, metallurgy, hospitals) are located. To determine their concentration the following analytical tools have been applied: accelerated solvent extraction– solid phase extraction – high performance liquid chromatography – UV-Vis (anionic SAAs) and conductivity (cationic SAAs) detectors. In all sediments anionic SAAs have been detected. The concentrations of HTMA and BDMA-C16in tested samples were higher than other cationic analytes. Generally, levels of surfactants with longer alkyl chains were higher and this observation can confirm their higher susceptibility to sorption on solid surfaces.
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Kukueva, V. V. "Quantum-Chemical Research of Fluoro Containing Hydrocarbons, That Have Fire Extinguishing Effect." Фізика і хімія твердого тіла 16, no. 3 (September 15, 2015): 511–14. http://dx.doi.org/10.15330/pcss.16.3.511-514.
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Through quantum-chemical calculations, a study was conducted to find the probable products of the destruction of molecules of extinguishing agents. The formation of atomic fluorine and trifluoromethane radical has been shown to contribute to the retardation of elementary reactions in the flame. It has been shown that active inhibitory components are more easily dissociated from the silica surface than in the case of bulk molecules.
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Makarewicz, Edwin, and Krzysztof Jan´czak. "The influence of organic diluents and solvents on the stability of PVC plastisol water dispersions." Polish Journal of Chemical Technology 9, no. 1 (January 1, 2007): 43–50. http://dx.doi.org/10.2478/v10026-007-0011-1.
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The influence of organic diluents and solvents on the stability of PVC plastisol water dispersions The work presents the research, the aim of which is to specify the influence of organic diluents and solvents such as xylene, toluene, n-butyl acetate and butanol as well as cyclohexanone on the stability of water dispersions of the PVC plastisol containing various surface-active agents (SAA). The applied surfactants were characterised by a specific ethoxylation number, molecular mass, the Hildebrand parameter, hydrophilic-hydrophobic balance, surface activity, the limiting viscosity number, the Haller interaction constant, the limiting equivalent conductivity and the Kohlrausch-Onsager equation "b" constant. Basing on the molar refraction and the Hildebrand parameter, the interactions between the plastisol constituents and the constituents of water dispersions of the PVC plastisol were established. The sedimentation tests on the PVC plastisol water dispersions stabilized by various surface-active agents with an organic diluent or solvent added indicated that the addition resulted in the dispergation yield, a reduction in the PVC plastisol molecular size in water dispersion and the increased Huggins interaction constant, showing both surface lyophilisation and higher adsorption of surface-active agents.
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Farberova, Еlena A., Anastasia Yu Katysheva, Elena A. Tingaeva, Sergey A. Smirnov, and Andrey G. Starostin. "RESEARCH OF POSSIBILITY OF USING CHEMICAL METHOD OF FINE METAL PARTICLES REDUCTION FOR BACTERICIDAL SORBENTS PRODUCTION." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENII KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 63, no. 3 (March 8, 2020): 46–53. http://dx.doi.org/10.6060/ivkkt.20206303.6047.
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The present paper is concerned with a research of sorption and bactericidal properties of the fine metal particles applied on the surface of active carbon fabric by chemical sedimentation method. The ascorbic acid and natrium borane were used in the study process as metals, copper and silver reducing agents. Influence of reducer and fine metal nature onto the porous structure, as well as bactericidal and sorption characteristics of obtained fibrous sorbent samples are shown. It is determined that use of ascorbic acid for synthesis of copper and silver fine particles on the active carbon fabrics surface leads to the considerable decrease in a specific surface and volumes of meso - and micropores of the obtained sorbent in comparison with initial active carbon fabric. When using the natrium borane as reducer of fine copper particles the decrease in a specific surface and volumes of sorption pores is also observed. However, when using the natrium borane, the active carbon fabric samples modified with silver particles or with their composition with fine copper particles, had the higher values of porous structure main characteristics in comparison with the initial active carbon fabric. The nature of distribution of fine metal particles at the active carbon fabric surface was investigated by the electronic microscopy method. It was found that during the chemical reduction process the particles of fine copper attached to active carbon fabric fibers, being almost evenly distributed at all surface of fabric. Particles of silver were located as crystal congestions along fibers. Sorption and bactericidal properties of the received samples of modified active carbon fabrics are investigated. Their high sensitivity to microorganism cells which remains during a long storage period is demonstrated. Herewith, the active carbon fabric, modified with particles of fine copper and silver, keeps high sorption properties.
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Chen, Qian Lin, Yu Guo, and Na Guo. "The Research of Extracting Hippuric Acid from Breeding Wastewater." Advanced Materials Research 550-553 (July 2012): 2215–18. http://dx.doi.org/10.4028/www.scientific.net/amr.550-553.2215.
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Hippuric acid as an important raw material used to synthesize medication and coloring matter, abound in urine of much animal, especially in cattle. Hippuric acid usually is letted into river and soil with the urine. But as its chemical stability, hippuric acid couldn’t be decomposed easily and pollute the environment. This research finds effectively liquid membrane to treat with such waste water such as breeding wastewater that contains high hippuric acid. In our study, the best liquid membrane was found by searching what and how much surface active agents and carrier are suitable, pH of out-water of the liquid membrane and concentration of NaOH in the in-water of liquid membrane. As the outcome shown, the best prescription is surface active agent T-151(2% mass fraction), liquid carrier TBP( 4% mass fraction), pH of out-water 2.0, concentration of NaOH in the in-water 0.50mol/L. Under the condition, extraction rate of hippuric acid from breeding wastewater can reach more than 98% during 9min.
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He, Song, Yanmei Zhang, Wansheng Yang, Xudong Zhao, and Bin Zeng. "Fabrication and Frosting Properties Study of Surface-Active Agents Coating Based on Nanoporous Aluminum Substrate." Energies 11, no. 10 (October 17, 2018): 2797. http://dx.doi.org/10.3390/en11102797.
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In order to solve the frosting and blockage problem of an air conditioning evaporator’s fin in winter, the nanoporous aluminum plates with low surface energy has been proposed in this paper, which are fabricated by an anodizing method and then modified by lauric acid. The nanoporous aluminum plates with different nanoporous diameters ranging from 15 nm to 400 nm are obtained by changing the magnitude of the oxidation current. The surface contact angle of the nanoporous aluminum plates is an important factor influencing its surface frost and condensation. The test results show that the surface contact angle is decreased with the increasing of nanoporous diameter. When the nanoporous aluminum plates are modified by lauric acid, the contact angle is proportional to the nanoporous diameter, and the maximum contact angle can reach about 171°. A set of experimental instruments has been set up to simulate the typical winter climate in northern China, and the frosting properties of the nanoporous aluminum plate’s fin is analyzed by experiment. The results show that increasing the contact angle of aluminum plates can effectively improve its anti-frosting properties. The average frosting rate of the aluminum plate with the contact angle of 60° is about 0.33 [g/(min∙m2)], which is 1.74 times that of the aluminum plate with the contact angle of 171°, whose frosting rate is about 0.19 [g/(min∙m2)]. After taking the expanded aperture processing to the aluminum plate, the diameter with 30 nm, 100 nm, 200 nm, 300 nm, and 400 nm nanoporous aluminum plates are obtained and the polished aluminum plates are also prepared for comparing. Through the test results, the nanoporous aluminum plates are shown to have anti-frosting properties, and the nanoporous aluminum plates with diameter of 300 nm are shown to have the best anti-frosting properties. The calculation mode of frosting growth is derived on the base of experimental results. This research will be helpful in indicating the potential research area of the low-carbon-emission and energy-saving technology for the researchers all over the world.
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Gao, Shang, Ren Ke Kang, Zhu Ji Jin, and Zhi Gang Dong. "Research on the Polishing Performance of CMP Slurry for the Sapphire Crystal." Advanced Materials Research 325 (August 2011): 457–63. http://dx.doi.org/10.4028/www.scientific.net/amr.325.457.
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Aiming at the problems such as metal ionic contamination, poor dispersion property and low material removal rate (MRR) in the chemical mechanical polishing (CMP) process for sapphire crystal, a proper CMP slurry based on the organic basis was studied in this paper. Through the single-factor experiment, the effect of different abrasives, pH regulators, dispersants and active agents on the surface roughness and material removal rate (MRR) were studied and a fine CMP slurry was developed. The polishing performance of developed CMP slurry was also researched by comparing the MRR and the surface roughness of sapphire crystal with that polished using the KA-901 CMP slurry. The results show that the MRR and the surface roughness corresponding to the developed slurry were all better than KA-901 slurry, and the developed CMP slurry has a good application prospect.
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Fischer, Theresa, Susana Suttor, Salma Mansi, Markus Ahrens, and Markus Eblenkamp. "Germ-Reducing Titanium Dioxide - Silicone Rubber Composites." Materials Science Forum 976 (January 2020): 3–8. http://dx.doi.org/10.4028/www.scientific.net/msf.976.3.
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Germs are present in all areas of everyday life and can lead to dangerous infections. Surfaces with antimicrobial properties are used to reduce the risk of infection in sanitary facilities and hospitals. Apart from the addition of biocides or antibiotic agents to synthetic materials, research shows that it is possible to use the semiconductor titanium dioxide (TiO2) to generate antibacterial surfaces. Photocatalytically active TiO2 leads to the development of reactive oxygen species (ROS) that are able to kill germs. The aim of this research is to use TiO2 to generate antibacterial bulk material. Nanostructured TiO2 particles were incorporated into silicone rubber to obtain a photocatalytic active polymer surface. High temperature vulcanizing (HTV) silicone rubber was used as a matrix material, and samples with 10 wt% of TiO2 were produced. The distribution of TiO2 particles in the matrix was analyzed via light microscopy. The photocatalytic activity on the surface of the test samples was studied via microbial testing with E.coli bacteria. The samples showed different intensities of the photocatalytic effect depending on the type of additive. The effort to create a germ reducing silicone rubber surface by using TiO2 as an additive was successful.
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Otřísal, Pavel, Jiří Slabotinský, Jakub Vaněk, and Stanislav Florus. "Chemical Warfare Agents Permeation Through Layered Adsorption Materials." International conference KNOWLEDGE-BASED ORGANIZATION 25, no. 3 (June 1, 2019): 144–55. http://dx.doi.org/10.1515/kbo-2019-0130.
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AbstractThe adsorption of permeating chemical compounds on the textile materials active surface is one of many principles of personal protection against dangerous chemical compounds including chemical warfare agents. The adsorption principle is generally known. However, its effective application especially in connection with the enhancing protection efficacy follows certain significant rules. A development of new textile materials based on the application of adsorbents in the combination with nanofibrous materials is the main topic of contemporary research in this area. This contribution sums up the theoretical basis of adsorption-based protective efficacy and also brings new experimental results of sorption and permeation of live CWA agents and their simulants through different samples of layered composite materials. Results are related to the basic structural parameters of nanotextiles and applied adsorbents.
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Żwawiak, Justyna, and Lucjusz Zaprutko. "Pharmaceutical applications of graphene." Postępy Higieny i Medycyny Doświadczalnej 71, no. 1 (February 15, 2017): 0. http://dx.doi.org/10.5604/01.3001.0010.3797.
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Nowadays, dynamic development in nanotechnological sciences is observed. Nanoparticles are frequently used in medicine and pharmacy as delivery systems for different kinds of active substances. One of the latest developed substances, with an unusually wide scope of utility, is graphene. The ways of its use in different fields of industry, not only pharmaceutical and medical, have been a subject of study for many research groups since the moment of its development in 2004. Graphene in pure form is highly hydrophobic. However, the presence of defects on its surface allows chemical modifications to be made, e.g. introduction of oxygen groups by covalent bonding. Also, non-covalent modifications are extensively used, including van der Waals forces, hydrogen bonding, coordination bonds, electrostatic and π-π stacking interactions. Due to the large surface area, graphene can be used in combination therapy, consisting in simultaneous administration of two or more pharmacologically active agents. Another interesting approach is gene therapy. Application of the PEI-graphene oxide system increased the efficacy of transfection. Possibilities of graphene and graphene oxide are not limited to their use as active substance delivery systems. These compounds by themselves were also found to be bacteriostatic and antibacterial agents.
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Zarnegar, Jake. "Semantic enrichment of life sciences content: how it works and key benefits for researchers." Emerging Topics in Life Sciences 2, no. 6 (December 21, 2018): 769–73. http://dx.doi.org/10.1042/etls20180168.
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In the time it takes a human life sciences researcher to read one research article machines can process hundreds of thousands of articles. An unco-ordinated army of bots, crawlers, and other software agents are active day and night on the Internet discovering, ingesting, and analyzing research content. Many of these agents are designed to help researchers rapidly filter the ever-expanding research record and surface the articles and findings most relevant to their work. For these software agents to be most effective, they need to understand the content they are reading in a manner similar to an expert human reader. (What are the main concepts being discussed and what are the main findings asserted? What is this research article telling us that is new and what is supporting or contradicting past findings?). This is where semantic enrichment comes into play — semantic enrichment adds structured machine-readable metadata to life science articles to assist software agents in ‘reading’ the content in a manner similar to a human researcher. In the present study, I'll define the mechanism of semantic enrichment of life sciences content, examine the benefits it is bringing to researchers today, and preview promising avenues for future benefits.
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Kim, Jin Ah, Dong Youl Yoon, and Jin-Chul Kim. "Oxidation-Triggerable Liposome Incorporating Poly(Hydroxyethyl Acrylate-co-Allyl methyl sulfide) as an Anticancer Carrier of Doxorubicin." Cancers 12, no. 1 (January 10, 2020): 180. http://dx.doi.org/10.3390/cancers12010180.
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Since cancer cells are oxidative in nature, anti-cancer agents can be delivered to cancer cells specifically without causing severe normal cell toxicity if the drug carriers are designed to be sensitive to the intrinsic characteristic. Oxidation-sensitive liposomes were developed by stabilizing dioleoylphosphatidyl ethanolamine (DOPE) bilayers with folate-conjugated poly(hydroxyethyl acrylate-co-allyl methyl sulfide) (F-P(HEA-AMS)). The copolymer, synthesized by a free radical polymerization, was surface-active but lost its surface activity after AMS unit was oxidized by H2O2 treatment. The liposomes with F-P(HEA-AMS) were sensitive to H2O2 concentration (0%, 0.5%, 1.0%, and 2.0%) in terms of release, possibly because the copolymer lost its surface activity and its bilayer-stabilizing ability upon oxidation. Fluorescence-activated cell sorting (FACS) and confocal laser scanning microscopy (CLSM) revealed that doxorubicin (DOX)-loaded liposomes stabilized with folate-conjugated copolymers markedly promoted the transport of the anti-cancer drug to cancer cells. This was possible because the liposomes were readily translocated into the cancer cells via receptor-mediated endocytosis. This liposome would be applicable to the delivery carrier of anticancer drugs.
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Silva, Wander José da, Rodrigo Nunes Rached, Pedro Luis Rosalen, and Altair Antoninha Del Bel Cury. "Effects of nystatin, fluconazole and propolis on poly(methyl methacrylate) resin surface." Brazilian Dental Journal 19, no. 3 (2008): 190–96. http://dx.doi.org/10.1590/s0103-64402008000300003.
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The prevalence of candidosis in denture wearers is as well established as its treatment with antifungal agents (AAs). However, little research has been done regarding the effects of AAs on denture base surfaces. Therefore, the aim of this study was to evaluate the effects of fluconazole (FLU), nystatin (NYS) and propolis orabase gel (PRO) on poly (methyl-methacrylate) (PMMA) surfaces. Deionized water and orabase gel without any active component were used as control groups. Conventional heat-polymerized (Clássico) and microwave-polymerized (Onda Cryl) acrylic resins were used. After polymerization, the specimens were polished and had their surfaces evaluated for roughness, free energy and Knoop hardness. Subsequently, specimens were immersed in AAs and controls for 14 days at 35±2 °C and all variables were measured again. Data were analyzed statistically by 2-way ANOVA followed by Tukey's test ( α=0.05). Roughness results showed similar behavior for both PMMA resins, with PRO reaching the highest values and differing significantly from the other AAs (p<0.05). No statistically significant differences (p>0.05) were found between the two PMMA resins or between NYS and FLU as regards surface free energy. In conclusion, PRO was able to induce changes in PMMA surface properties, such as roughness, which could be related to microbial adhesion.
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Widdicombe, Jonathan H. "Early studies on the surface epithelium of mammalian airways." American Journal of Physiology-Lung Cellular and Molecular Physiology 317, no. 4 (October 1, 2019): L486—L495. http://dx.doi.org/10.1152/ajplung.00240.2019.
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This article traces the beginnings of the various areas of physiological research on airway epithelium. First mentioned in 1600, it was not until 1834 that it was found to be ciliated. Goblet and basal cells were described in 1852, to be followed by ~10 other epithelial cell types (the most recent in 2018). It also contains nerve endings and resident leukocytes. Mucociliary clearance was documented in 1835, but the first studies on the ciliary beat cycle did not appear until 1890, and a definitive description was not published until 1981. It was established in 1932 that goblet cells in the cat trachea were unresponsive to cholinergic agents; but only since 1980 or so has any significant progress been made on what does cause them to degranulate. Active transfer of salts across epithelia creates local osmotic gradients that drive transepithelial water flows. Vectorial salt transport was first described for airway epithelium in 1968, and the associated volume flows were measured in 1981. Evidence that airway epithelium releases signaling molecules first appeared in 1981. Since then, scores of molecules have been identified. The pace of research in most areas increased dramatically after the development of confluent, polarized cultures of airway epithelium in the early 1980s.
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Rakesh, Kadallipura P., Nanjudappa Darshini, Honnayakanakalli M. Manukumar, Hamse K. Vivek, Mohammed Y. H. Eissa, Doddakunche S. Prasanna, and Ningegowda Mallesha. "Xanthone Conjugated Amino Acids as Potential Anticancer and DNA Binding Agents: Molecular Docking, Cytotoxicity and SAR Studies." Anti-Cancer Agents in Medicinal Chemistry 18, no. 15 (February 28, 2019): 2169–77. http://dx.doi.org/10.2174/1871520618666180903105256.
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Background: Amino acids conjugated with heterocyclic molecules are well known for their effective bioactive properties. In search of effective anticancer agents, a series of xanthone linked amino acids 2-23 were synthesized and tested for in vitro anticancer activity. Methods: In vitro anticancer activity of the synthesized xanthone linked amino acids 2-23 are tested against three different cancer cell lines MCF-7, MDA-MB-435 and A549 by MTT assay and validated by DNA binding and molecular docking approaches. Doxorubicin and ethidium bromide used as standard and positive control respectively. Results: Compounds 7, 8 and 9 exhibited potent anticancer activity against tested cancer cell lines and DNA binding study using methyl green. In the molecular docking study, binding interactions of the most active compounds 7, 8 and 9 were confirmed to molecular surface of DNA. Conclusion: Structure-Activity Relationship (SAR) showed that the aromatic and hydrophobic amino acids (phenylalanine, tyrosine, and tryptophan) favoured the DNA binding studies and anticancer activity whereas, aliphatic amino acids showed least anticancer activity.
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Wisniewski, Michael. "Characterization of Ice Nucleation and Propagation in Bean (Phaseolus vulgaris cv. Bush Blue Lake) using Infrared Video Thermography." HortScience 32, no. 3 (June 1997): 538C—538. http://dx.doi.org/10.21273/hortsci.32.3.538c.
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Frost-sensitive plant species have a limited ability to tolerate ice formation in their tissues. Most plants can supercool below 0°C and avoid ice formation. Discrepancies exist about the role of intrinsic and extrinsic ice-nucleating agents in initiating ice formation in plants. Previous research has demonstrated the ability of infrared video thermography to directly observe and record the freezing process in plants (Wisniewski et al., 1997. Plant Physiol. 113:4378–4397). In the present study, the ability of droplets of a suspension of the ice-nucleating-active (Ice+) bacterium, Pseudomonas syringae, and droplets of deionized water, to induce ice formation in bean plants was compared. The activity of these agents were also compared to intrinsic ice formation in dry plants. Results indicated that the presence of the Ice+ bacteria in droplets ranging from 0.5–4.0 μL always induced freezing at a warmer temperature than droplets of deionized water alone (no bacteria) or intrinsic nucleators in dry plants. When droplets of Ice+ bacteria were allowed to dry, they were no longer effective but were active again upon rewetting. Droplets of water would often supercool below temperatures at which ice formation was initiated by intrinsic agents. When a silicon grease barrier was placed between the droplets of Ice+ bacteria and the leaf surface, the bacteria were no longer capable of inducing ice formation in the plant, despite the droplets being frozen on the plant surface. This indicates that ice crystals must penetrate the cuticle in order to induce freezing of the plant.
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Costagliola, Ciro, Francesco Semeraro, Roberto dell’Omo, Lucio Zeppa, Gennaro Bufalo, Michele Cardone, Mario Romano, and Luigi Ambrosone. "Some Physicochemical Remarks on Spontaneous Emulsification of Vitreal Tamponades." BioMed Research International 2014 (2014): 1–6. http://dx.doi.org/10.1155/2014/243056.
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The importance of gravitational instability in determining the emulsification of vitreal tamponades is discussed. Theoretical results and numerical simulations indicate that the spontaneous formation of water-silicon oil is a rare event and that the very low concentration of surface active agents cannot justify the systematic formation of emulsions. The gravitational instabilities seem to play the main role. Our theoretical results seem in agreement with the experimental evidences; furthermore they indicate a future research line for the improvement of endotamponades. Indeed, the use of biodegradable antifoam may avoid the formation of bubbles and delay the formation of emulsions.
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Disanto, Giulio, Antonio J. Berlanga, Adam E. Handel, Andrea E. Para, Amy M. Burrell, Anastasia Fries, Lahiru Handunnetthi, Gabriele C. De Luca, and Julia M. Morahan. "Heterogeneity in Multiple Sclerosis: Scratching the Surface of a Complex Disease." Autoimmune Diseases 2011 (2011): 1–12. http://dx.doi.org/10.4061/2011/932351.
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Multiple Sclerosis (MS) is the most common demyelinating disease of the central nervous system. Although the etiology and the pathogenesis of MS has been extensively investigated, no single pathway, reliable biomarker, diagnostic test, or specific treatment have yet been identified for all MS patients. One of the reasons behind this failure is likely to be the wide heterogeneity observed within the MS population. The clinical course of MS is highly variable and includes several subcategories and variants. Moreover, apart from the well-established association with the HLA-class II DRB1*15:01 allele, other genetic variants have been shown to vary significantly across different populations and individuals. Finally both pathological and immunological studies suggest that different pathways may be active in different MS patients. We conclude that these “MS subtypes” should still be considered as part of the same disease but hypothesize that spatiotemporal effects of genetic and environmental agents differentially influence MS course. These considerations are extremely relevant, as outcome prediction and personalised medicine represent the central aim of modern research.
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Fritt-Rasmussen, Janne, Kim Gustavson, Susse Wegeberg, Eva Friis Møller, Rasmus Dyrmose Nørregaard, Pia Lassen, Ian Buist, et al. "Ongoing Research on Herding Agents for In Situ Burning in Arctic Waters: Studies on Fate and Effects." International Oil Spill Conference Proceedings 2017, no. 1 (May 1, 2017): 2976–95. http://dx.doi.org/10.7901/2169-3358-2017.1.2976.
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ABSTRACT Research on the fate and effects of herding agents used to contain and thicken oil slicks for in situ burning in Arctic waters continues under the auspices of the International Association of Oil and Gas Producers Arctic Oil Spill Response Technology – Joint Industry Program (JIP). In 2014/2015 laboratory studies were conducted on the fate and effects of herders. The purpose of the studies was to improve the knowledge base used to evaluate the environmental risk of using herders in connection with in situ burning for oil spill response in Arctic seas. Two herding agents were studied (OP 40 and ThickSlick 6535). Laboratory-scale herding and burning experiments were carried out for investigating the physical fate of the two herders during combustion of Alaska North Slope and Grane crude oils (fresh and emulsified). The results showed that after burning, the herder was mainly found on the water surface, and only small concentrations of herders were found in the water column (0.2–22.8 mg/L). The inherent properties of herders in relation to toxicity and bioaccumulation on the high Arctic copepods (Calanus hyperboreus), as well as the biodegradability of herders were studied under arctic conditions. The results indicated that a distinct mortality was seen at the highest test concentrations of the herders. However, the concentration of herders required to produce acute toxicity in the laboratory was approximately three orders of magnitude higher than the concentrations measured in the water column when herders were used to conduct an in situ burn in the laboratory. OP-40 might bio-accumulate whereas TS6535 might not. TS6535 was mostly degraded within 7 days, whereas the degradation of OP-40 was insignificant over 28 days. Since herders are mainly considered as a surface active chemical compound, the potential impacts of herders on Arctic seabird feathers (from legally hunted Thick-Billed Murre and Common Eider) were investigated. Different dosages of herders were tested; high dosages that might be present just after the application of the herder and low dosages (approximately monolayers) likely to occur for a significant time and distance from the operations. Low dosages corresponding to approximately monolayers of OP-40 and TS6535 did not cause feathers to sink; however they did absorb more water than the controls. The high dosages caused measured damages to the feather microstructure. Finally, laboratory burning experiments were carried out to determine if there was a difference in the composition of smoke plumes from mechanically contained burns versus herded oil burns. Herder was not measured in the smoke plumes, and there were no other noticeable differences in combustion between the two methods of containment (herder vs. metal ring).
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Chen, Mingfei, Yingxue Tu, and Songhai Wu. "Preparation of UiO-66-NH2@PDA under Water System for Chemical Warfare Agents Degradation." Materials 14, no. 9 (May 6, 2021): 2419. http://dx.doi.org/10.3390/ma14092419.
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There is an urgent need to develop catalytic degradation technologies for chemical warfare agents (CWAs) that are environmentally friendly and do not require secondary treatment. UiO-66-NH2 and other metal–organic frameworks (MOFs) based on zirconium have been shown to promote the catalytic degradation of CWAs. At the same time, MOFs have been studied, and they have shown interesting properties in CWA removal because of their ultrahigh surface area, tunable structures, and periodically distributed abundant catalytic sites. However, MOFs synthesized by conventional methods are mostly powdery crystals that are difficult to process and have poor mechanical stability, which largely limit the development of MOFs in practical applications. An emerging trend in MOF research is hybridization with flexible materials. Polymers possess a variety of unique attributes, such as flexibility, thermal and chemical stability, and process ability, and these properties can be combined with MOFs to make a low-cost and versatile material that also provides convenience for the subsequent integration of such MOFs into independent substrates or textiles. In this article, we used a green and simple method to coat the surface of UiO-66-NH2 with polydopamine (PDA), PDA can promote the catalytic hydrolysis of UiO-66-NH2 to DMNP (a simulant of chemical warfare agents). Additionally, it can adsorb the toxic hydrolysis product p-nitrophenol, avoiding the trouble of secondary treatment. The half-life of UiO-66-NH2 coated with polydopamine (UiO-66-NH2@PDA) for catalytic hydrolysis is 8.9 min, and that of pure UiO-66-NH2 is 20 min. We speculate that the surface coated with PDA can improve the diffusion of DMNP to the active sites of UiO-66-NH2.
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Pacholak, Amanda, Natalia Burlaga, and Ewa Kaczorek. "Evaluating the Effect of Azole Antifungal Agents on the Stress Response and Nanomechanical Surface Properties of Ochrobactrum anthropi Aspcl2.2." Molecules 25, no. 15 (July 23, 2020): 3348. http://dx.doi.org/10.3390/molecules25153348.
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Azole antifungal molecules are broadly used as active ingredients in various products, such as pharmaceuticals and pesticides. This promotes their release into the natural environment. The detailed mechanism of their influence on the biotic components of natural ecosystems remains unexplored. Our research aimed to examine the response of Ochrobactrum anthropi AspCl2.2 to the presence of four azole antifungal agents (clotrimazole, fluconazole, climbazole, epoxiconazole). The experiments performed include analysis of the cell metabolic activity, cell membrane permeability, total glutathione level and activity of glutathione S-transferases. These studies allowed for the evaluation of the cells’ oxidative stress response to the presence of azole antifungals. Moreover, changes in the nanomechanical surface properties, including adhesive and elastic features of the cells, were investigated using atomic force microscopy (AFM) and spectrophotometric methods. The results indicate that the azoles promote bacterial oxidative stress. The strongest differences were noted for the cells cultivated with fluconazole. The least toxic effect has been attributed to climbazole. AFM observations unraveled molecular details of bacterial cell texture, structure and surface nanomechanical properties. Antifungals promote the nanoscale modification of the bacterial cell wall. The results presented provided a significant insight into the strategies used by environmental bacterial cells to survive exposures to toxic azole antifungal agents.
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Miller, Urszula, Izabela Sówka, and Waldemar Adamiak. "The application of Brij 35 in biofiltration of the air polluted with toluene vapours." E3S Web of Conferences 44 (2018): 00113. http://dx.doi.org/10.1051/e3sconf/20184400113.
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Removal of certain organic pollutants from the environment may be hindered due to their weak water solubility and high vapour pressure. In particular, these are factors that limit the application of biological methods in remediation since they have an influence on the bio-accessibility of the xenobiotics. For that reason, we carried out research on the use of surface-active agents that have impact on the increase in solubility of hydrophobic compounds. In this publication, we present the results of laboratory tests on the application of Brij 35 in purification of the air polluted with toluene vapours by the biofiltration method. Within the range of surfactant concentrations subjected to the research (200, 300, 400 mg/dm3), we observed an improvement of the removal efficiency as compared to the control series (without the surfactant).
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Taskila, Sanna, Mikko Ahokas, Juho Järvinen, Juho Toivanen, and Juha P. Tanskanen. "Concentration and Separation of Active Proteins from Potato Industry Waste Based on Low-Temperature Evaporation and Ethanol Precipitation." Scientifica 2017 (2017): 1–6. http://dx.doi.org/10.1155/2017/5120947.
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Purpose. Potato fruit juice, a residue of starch industry, contains up to 2.5% [w/w] of proteins that are potentially valuable raw-materials of food, cosmetic, and pharma industries. The recovery of protein from the potato fruit juice is limited by the lack of industrially feasible concentration and separation technologies. The present research thus aimed at development of such process for the separation of active protease inhibitors from potato fruit juice.Methods. Low temperature mechanical vapor recompression evaporation was applied for concentration of potato fruit juice followed by ethanol precipitation for recovery of active proteins. The effects of precipitation temperature and precipitative agents were investigated employing response surface modeling methodology.Results. Concentration of potato fruit juice by evaporation was successful without loss of trypsin inhibition activity. Precipitation using 6.5 M ethanol at low temperature (0–+4°C) was found suitable for the recovery of active protease inhibitors from the concentrate. Piloting at starch industry yielded 50% of total proteins, with a high quantity of active protease inhibitors and a minor inclusion of other proteins.Conclusion. Concentration by low-temperature evaporation, followed by ethanol precipitation of protease inhibitors at optimized temperature, is an attractive option for valorization of potato fruit juice.
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Croitoru, Alexa, Ovidiu Oprea, Adrian Nicoara, Roxana Trusca, Mihai Radu, Ionela Neacsu, Denisa Ficai, Anton Ficai, and Ecaterina Andronescu. "Multifunctional Platforms Based on Graphene Oxide and Natural Products." Medicina 55, no. 6 (May 30, 2019): 230. http://dx.doi.org/10.3390/medicina55060230.
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Background and objectives: In the last few years, graphene oxide has attracted much attention in biomedical applications due to its unique physico-chemical properties and can be used as a carrier for both hydrophilic and/or hydrophobic biomolecules. The purpose of this paper was to synthesize graphene oxide and to obtain multifunctional platforms based on graphene oxide as a nanocarrier loaded with few biologically active substances with anticancer, antimicrobial or anti-inflammatory properties such as gallic acid, caffeic acid, limonene and nutmeg and cembra pine essential oils. Materials and Methods: Graphene oxide was obtained according to the method developed by Hummers and further loaded with biologically active agents. The obtained platforms were characterized using FTIR, HPLC, TGA, SEM, TEM and Raman spectroscopy. Results: Gallic acid released 80% within 10 days but all the other biologically active agents did not release because their affinity for the graphene oxide support was higher than that of the phosphate buffer solution. SEM characterization showed the formation of nanosheets and a slight increase in the degree of agglomeration of the particles. The ratio I2D/IG for all samples was between 0.18 for GO-cembra pine and 0.27 for GO-limonene, indicating that the GO materials were in the form of multilayers. The individual GO sheets were found to have less than 20 µm, the thickness of GO was estimated to be ~4 nm and an interlayer spacing of about 2.12 Å. Raman spectroscopy indicated that the bioactive substances were adsorbed on the surface and no degradation occurred during loading. Conclusions: These findings encourage this research to further explore, both in vitro and in vivo, the biological activities of bioactive agents for their use in medicine.
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Jokinen, Mika, Mika Koskinen, and Sami Areva. "Rationale of Using Conventional Sol-Gel Derived SiO2 for Delivery of Biologically Active Agents." Key Engineering Materials 377 (March 2008): 195–210. http://dx.doi.org/10.4028/www.scientific.net/kem.377.195.
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Progress in the research of mesoporous materials, hierarchical pore structures, chemical modification of surfaces, nanoparticle processing and hybrid materials is important and it provides new and interesting functional properties for silica structures. However, this has also left the conventional, alkoxy-based sol-gel derived silica in the shadow, although it has a lot of non-utilized potential, especially in the delivery and/or encapsulation of sensitive biologically active agents like viral vectors, proteins, nucleic acids and cells. The potential lies in the versatile possibilities to adjust the structure by using alkoxides as precursors and in the proper use of water in different steps of the processing. The conventional, alkoxy-based sol-gel silica structure can be processed so that it results in largely variable biodegradation rates, biodegradation-controlled release of encapsulated agents and beneficial environment even for highly sensitive agents. These kinds of silica structures contain more or less water and hence, they are more or less labile from the traditional viewpoint of materials science. In extreme case they could be called “unfinished silica”. The aim of this paper is to discuss how the biodegradation rate of these kinds of silica materials can be adjusted on a large scale and how this is related to a rather narrow scale adjustment of in vitro dissolution rate of silica, how the unfinished silica structures can be controlled and their properties adjusted, how they can be utilized in the delivery of biologically active agents, and what the potential problems to be solved are.
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Call-Cummings, Meagan, Melissa Hauber-Özer, and Karen Ross. "Struggling with/against the unintentional reproduction of power structures in participatory research: Using reconstructive horizon analysis." Action Research 18, no. 2 (April 3, 2019): 171–93. http://dx.doi.org/10.1177/1476750319837324.
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Shared power and democratic decision making are core epistemological commitments of participatory action research. Scholars who engage in participatory action research with youth seek to share ownership and disrupt adult/child or knower/learner binaries traditional in the Global North, in which adults are the active agents who own and transfer knowledge to children, who remain in a passive role. Yet, we have noticed during several of our projects with youth that, despite our best efforts, these knower/learner binaries can be reproduced with younger coresearchers as we exhibit care in the form of protection and provision of security. In this article, we examine three scenes from our recent youth participatory action research projects using reconstructive horizon analysis to surface and explore backgrounded validity claims that highlight the tensions between our efforts to democratize the research process and our commitment to an ethic of care for those with whom we engage in participatory knowledge production. We suggest that explicit attention to these tensions as part of the inquiry process is important for making participatory research with youth a more equitable endeavor and to build the validity of such work.
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Ahmari, Hadi, and Mohammad Chalkesh Amiri. "On the relationship between surface tension and viscosity of fluids." Chemical Engineering Research Bulletin 18, no. 1 (January 4, 2016): 18. http://dx.doi.org/10.3329/cerb.v18i1.26217.
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<p>Relating surface tension and viscosity of liquids not only is important conceptually but it can also be used to test the validity of some measured data. Schonhorn modified Pelofsky’s equation by introducing the concept of the vapor viscosity η<sub>v</sub> in equilibrium with the liquid, i.e.γ= Aexp(-B/(η<sub>l</sub>-η<sub>v</sub>)) This empirical relation can be applied to both organic and inorganic solutions of pure and mixed components. As surface tension is a strong function of surfactant, they neglected to emphasis that mixed components must not be surface active agents. Both Pelofsky and Schonhorn indicated that A may be an indication of the surface tension of the liquid at the temperature where η=∞. They were not successful in correlating the temperature where and the surface tension at the melting point. In this work, a new empirical equation for relating surface tension and viscosity has been developed, i.e., γ((Tc – Tm)/( Tc – T)) = δ(1-β/η). This equation not only satisfies the extreme conditions but it also reveals a physical concept for δ, that is, it should equal the surface tension at the melting point of the liquid.</p><p>Chemical Engineering Research Bulletin 18(2015) 18-22</p>
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Fatehi, Leili, Susan M. Wolf, Jeffrey McCullough, Ralph Hall, Frances Lawrenz, Jeffrey P. Kahn, Cortney Jones, et al. "Recommendations for Nanomedicine Human Subjects Research Oversight: An Evolutionary Approach for an Emerging Field." Journal of Law, Medicine & Ethics 40, no. 4 (2012): 716–50. http://dx.doi.org/10.1111/j.1748-720x.2012.00703.x.
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Nanomedicine is yielding new and improved treatments and diagnostics for a range of diseases and disorders. Nanomedicine applications incorporate materials and components with nanoscale dimensions (often defined as 1-100 nm, but sometimes defined to include dimensions up to 1000 nm, as discussed further below) where novel physiochemical properties emerge as a result of size-dependent phenomena and high surface-to-mass ratio. Nanotherapeutics and in vivo nanodiagnostics are a subset of nanomedicine products that enter the human body. These include drugs, biological products (biologics), implantable medical devices, and combination products that are designed to function in the body in ways unachievable at larger scales. Nanotherapeutics and in vivo nanodiagnostics incorporate materials that are engineered at the nanoscale to express novel properties that are medicinally useful. These nanomedicine applications can also contain nanomaterials that are biologically active, producing interactions that depend on biological triggers. Examples include nanoscale formulations of insoluble drugs to improve bioavailability and pharmacokinetics, drugs encapsulated in hollow nanoparticles with the ability to target and cross cellular and tissue membranes (including the bloodbrain barrier) and to release their payload at a specific time or location, imaging agents that demonstrate novel optical properties to aid in locating micrometastases, and antimicrobial and drug-eluting components or coatings of implantable medical devices such as stents.
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Olkowska, Ewa, Marek Ruman, Anna Kowalska, and Żaneta Polkowska. "Determination of Surfactants in Environmental Samples. Part II. Anionic Compounds." Ecological Chemistry and Engineering S 20, no. 2 (June 1, 2013): 331–42. http://dx.doi.org/10.2478/eces-2013-0024.
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Abstract Surface active agents (SAA) with negative charge of polar group are named as anionic compounds. They are the main constituent of most products containing synthetic surfactants. The linear alkylbenzene sulfonates (LAS), alkyl ethoxysulfates (AES) and alkyl sulfates (AS) are typically applied from this class of compounds. Those surfactants are ingredients of household detergents and cleaners, laundry detergents, cosmetic etc. Moreover they can be applied in the paper, textile and tanning industry as optical brighteners, dispersant, wetting and suspending agents. They can be substrates in the formulation of different products like dyes, pigments, pesticides, exchange resins, plasticizers and pharmaceuticals. Anionic surfactants after use are passed into sewage-treatment plants, where they are partially degraded and adsorbed to sewage sludge (applied in agriculture fields). Finally, the anionic SAA or their degradation products are discharged into surface waters and onto bottom sediments, soils or living organisms. Therefore, it is important (widely application, bioaccumulation, toxicity for living organisms) to investigate the environmental fate of those class of compounds in more details. This research involves determination the concentration of anionic surfactants with use appropriated analytical techniques in environmental samples The official methodology for determination of anionic SAA in liquid samples is based on the ion-pair reaction of these analytes compounds with methylene blue (MB) and an extraction with toxic solvent chloroform. During isolation step of anionic compounds from solid samples are employed Soxhlet and ultrasonic-assisted extraction techniques with use of methanol or mixture of other organic solvents as extraction medium. To overcome disadvantages of those traditional techniques were applied following techniques at sample preparation step from liquid and solid matrices: solid-phase extraction (SPE) and solid-phases microextraction (SPME); accelerated solvent extraction (ASE), microwave-assisted extraction (MAE), supercritical fluid extraction (SFE), respectively. For estimate total concentration of anionic analytes in extracts the spectrophotometric technique is used (as official regulation). For determination concentration of individual analytes were applied gas (derivatization step requires) and liquid chromatography mainly with mass spectrometry technique. The presence of anionic surface active agents was confirmed in various ecosystems (liquid and solid environmental samples).
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Carregal-Romero, Susana, Sandra Plaza-García, Rafael Piñol, José Murillo, Jesús Ruiz-Cabello, Daniel Padro, Angel Millán, and Pedro Ramos-Cabrer. "MRI Study of the Influence of Surface Coating Aging on the In Vivo Biodistribution of Iron Oxide Nanoparticles." Biosensors 8, no. 4 (December 12, 2018): 127. http://dx.doi.org/10.3390/bios8040127.
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Medical imaging is an active field of research that fosters the necessity for novel multimodal imaging probes. In this line, nanoparticle-based contrast agents are of special interest, since those can host functional entities either within their interior, reducing potential toxic effects of the imaging tracers, or on their surface, providing high payloads of probes, due to their large surface-to-volume ratio. The long-term stability of the particles in solution is an aspect usually under-tackled during probe design in research laboratories, since their performance is generally tested briefly after synthesis. This may jeopardize a later translation into practical medical devices, due to stability reasons. To dig into the effects of nanoparticle aging in solution, with respect to their behavior in vivo, iron oxide stealth nanoparticles were used at two stages (3 weeks vs. 9 months in solution), analyzing their biodistribution in mice. Both sets of nanoprobes showed similar sizes, zeta potentials, and morphology, as observed by dynamic light scattering (DLS) and transmission electronic microscopy (TEM), but fresh nanoparticles accumulated in the kidneys after systemic administration, while aged ones accumulated in liver and spleen, confirming an enormous effect of particle aging on their in vivo behavior, despite barely noticeable changes perceived on a simple inspection of their structural integrity.
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Goshen-Lago, Tal, Moran Szwarcwort-Cohen, Madeleine Benguigui, Ronit Almog, Ilit Turgeman, Nelly Zaltzman, Michael Halberthal, Yuval Shaked, and Irit Ben-Aharon. "The Potential Role of Immune Alteration in the Cancer–COVID19 Equation—A Prospective Longitudinal Study." Cancers 12, no. 9 (August 26, 2020): 2421. http://dx.doi.org/10.3390/cancers12092421.
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Background: The risk of cancer patients to develop COVID19 infection is unclear. We aimed to prospectively study cancer patients and oncology healthcare workers for COVID19 serology. In IgG+ cases, immune profile was determined to portray the pattern of immune response to SARS-CoV2. Methods: Cancer patients on active treatment and healthcare workers were enrolled. During the study period (3/2020–6/2020), demographic data and blood were collected at three time points. Expression of IgG, IgM, and IgA were assessed. In SARS-CoV-2 IgG+ cases and matched negative cases, we performed mass cytometry time of flight (CyTOF) analysis on the basis of the expression of surface markers. Results: The study included 164 cancer patients on active intravenous treatment and 107 healthcare workers at the cancer center. No symptomatic cases were reported during the study period. Serology analysis revealed four IgG+ patients (2.4%) and two IgG+ healthcare workers (1.9%)—all were asymptomatic. CyTOF analysis demonstrated substantial reduction in myeloid cells in healthcare workers who were SARS-CoV-2 IgG+ compared to those who were SARS-CoV-2 IgG-, whereas in cancer patients, the reduction was relatively milder (≈50% reduction in SARS-CoV-2 IgG+ cancer patients compared with ≈90% reduction in SARS-CoV-2 IgG+ workers). Conclusion: Our results indicate a similar rate of asymptomatic COVID19 infection in cancer patients and healthcare workers in a longitudinal study throughout the pandemic time. Due to differential immune cell profiles of cancer patients who are treated with immunomodulatory agents, the host response to the SARS-COV2 may play a role in COVID19 course and representation. The immunological perspective of cancer treatments on the risk for COVID19 infection should be further explored.
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Huang, Bin, Chen Wang, Weisen Zhang, Cheng Fu, Haibo Liu, and Hongwei Wang. "Study on the Stability of Produced Water from Alkali/Surfactant/Polymer Flooding under the Synergetic Effect of Quartz Sand Particles and Oil Displacement Agents." Processes 8, no. 3 (March 9, 2020): 315. http://dx.doi.org/10.3390/pr8030315.
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With the wide application of ASP (alkali/surfactant/polymer) flooding oil recovery technology, the produced water from ASP flooding has increased greatly. The clay particles carried by crude oil in the process of flow have a synergetic effect with oil displacement agents in the produced water, which increases the treatment difficulty of produced water. The stability of produced water is decided by the stability of oil droplets in the ASP-flooding-produced water system. The oil content, Zeta potential, interfacial tension and oil droplet size are important parameters to characterize the stability of produced water. In this paper, the changes of the oil content, Zeta potential, interfacial tension and oil droplet size of ASP flooding oily wastewater under the synergetic effect of different concentrations of quartz sand particles and oil displacement agents were studied by laboratory experiments. The experimental results show that the negatively charged quartz sand particles can absorb active substances in crude oil and surfactant molecules in the water phase and migrate to the oil–water interface, which increases the repulsion between quartz sand particles, decreasing the oil–water interfacial tension. Thus, the stability of oil droplets is enhanced, and the aggregation difficulty between oil droplets and quartz sand particles is increased. With the continually increasing quartz sand concentration, quartz sand particles combine with surfactant molecules adsorbed on the oil–water interface to form an aggregate. Meanwhile, the polymer molecules crimp from the stretching state, and the number of them surrounding the surface of the flocculation structure is close to saturation, which makes the oil droplets and quartz sand particles prone to aggregation, and the carried active substances desorb from the interface, resulting in the instability of the produced water system. The research on the synergetic effect between quartz sand particles and oil displacement agents is of great significance for deepening the treatment of ASP-produced water.
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Rowinsky, Eric K., Jolene J. Windle, and Daniel D. Von Hoff. "Ras Protein Farnesyltransferase: A Strategic Target for Anticancer Therapeutic Development." Journal of Clinical Oncology 17, no. 11 (November 1999): 3631–52. http://dx.doi.org/10.1200/jco.1999.17.11.3631.
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ABSTRACT: Ras proteins are guanine nucleotide–binding proteins that play pivotal roles in the control of normal and transformed cell growth and are among the most intensively studied proteins of the past decade. After stimulation by various growth factors and cytokines, Ras activates several downstream effectors, including the Raf-1/mitogen-activated protein kinase pathway and the Rac/Rho pathway. In approximately 30% of human cancers, including a substantial proportion of pancreatic and colon adenocarcinomas, mutated ras genes produce mutated proteins that remain locked in an active state, thereby relaying uncontrolled proliferative signals. Ras undergoes several posttranslational modifications that facilitate its attachment to the inner surface of the plasma membrane. The first—and most critical—modification is the addition of a farnesyl isoprenoid moiety in a reaction catalyzed by the enzyme protein farnesyltransferase (FTase). It follows that inhibiting FTase would prevent Ras from maturing into its biologically active form, and FTase is of considerable interest as a potential therapeutic target. Different classes of FTase inhibitors have been identified that block farnesylation of Ras, reverse Ras-mediated cell transformation in human cell lines, and inhibit the growth of human tumor cells in nude mice. In transgenic mice with established tumors, FTase inhibitors cause regression in some tumors, which appears to be mediated through both apoptosis and cell cycle regulation. FTase inhibitors have been well tolerated in animal studies and do not produce the generalized cytotoxic effects in normal tissues that are a major limitation of most conventional anticancer agents. There are ongoing clinical evaluations of FTase inhibitors to determine the feasibility of administering them on dose schedules like those that portend optimal therapeutic indices in preclinical studies. Because of the unique biologic aspects of FTase, designing disease-directed phase II and III evaluations of their effectiveness presents formidable challenges.
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Zheng, Ji Yong, Cun Guo Lin, Lan Lan Di, Dong Xia Duan, Hui Ding, Li Wang, Jin Wei Zhang, Yan Lei Peng, and Juan Zhou. "Natural Antifouling Materials from Marine Plants Ulva pertusa." Advanced Materials Research 79-82 (August 2009): 1079–82. http://dx.doi.org/10.4028/www.scientific.net/amr.79-82.1079.
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Marine biofouling on the surface of ship hull causes the hydrodynamic drag, fuel increase, and higher costs. In this case antifouling paint is often used to protect the submerged surface from marine organisms. In traditional antifouling paints, toxic biocides have been banned due to their severe environmental pollution. To develop novel environmental benign antifouling agents has been our pursuit, and among them, active substances from marine organism for antifouling application are our research focus. In the paper, a natural material in halobios was isolated from a kind of algae Ulva pertusa, which is the most common green alga. The antifouling activities of their extracts were screened by bioassays with two kinds of fouling organisms, diatom and mussel. The crude extract of ethyl acetate was found to be most active against diatom. Silica gel column chromatography (SGCC) and high performance liquid chromatography (HPLC) were used to further isolate the extract of ethyl acetate. In the SGCC extraction, four elution bands were collected, and minimum inhibitory concentrations (MIC) against diatom were determined. Among the four bands, the lowest MIC is 0.7 mg/mL, related to the band YC-EA. The YC-EA band was separated into four parts, and the second part (EE2) showed an inhibitive effect on the settlement of diatom and mussel. The natural product of EE2 can be characterized by a coupled liquid chromatography-mass spectrometry (LC-MS). Results demonstrated that there are antifouling active substances among extracts of Ulva pertusa. Compounds would be a potentially natural antifouling material, resulting in higher standards of environmental safety with outstanding antifouling performance.
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Cavalu, Simona, Iulian Vasile Antoniac, Aurel Mohan, Florian Bodog, Cristian Doicin, Ileana Mates, Mihaela Ulmeanu, Roman Murzac, and Augustin Semenescu. "Nanoparticles and Nanostructured Surface Fabrication for Innovative Cranial and Maxillofacial Surgery." Materials 13, no. 23 (November 27, 2020): 5391. http://dx.doi.org/10.3390/ma13235391.
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A novel strategy to improve the success of soft and hard tissue integration of titanium implants is the use of nanoparticles coatings made from basically any type of biocompatible substance, which can advantageously enhance the properties of the material, as compared to its similar bulk material. So, most of the physical methods approaches involve the compaction of nanoparticles versus micron-level particles to yield surfaces with nanoscale grain boundaries, simultaneously preserving the chemistry of the surface among different topographies. At the same time, nanoparticles have been known as one of the most effective antibacterial agents and can be used as effective growth inhibitors of various microorganisms as an alternative to antibiotics. In this paper, based on literature research, we present a comprehensive review of the mechanical, physical, and chemical methods for creating nano-structured titanium surfaces along with the main nanoparticles used for the surface modification of titanium implants, the fabrication methods, their main features, and the purpose of use. We also present two patented solutions which involve nanoparticles to be used in cranioplasty, i.e., a cranial endoprosthesis with a sliding system to repair the traumatic defects of the skull, and a cranial implant based on titanium mesh with osteointegrating structures and functional nanoparticles. The main outcomes of the patented solutions are: (a) a novel geometry of the implant that allow both flexible adaptation of the implant to the specific anatomy of the patient and the promotion of regeneration of the bone tissue; (b) porous structure and favorable geometry for the absorption of impregnated active substances and cells proliferation; (c) the new implant model fit 100% on the structure of the cranial defect without inducing mechanical stress; (d) allows all kinds of radiological examinations and rapid osteointegration, along with the patient recover in a shorter time.
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Taba, Paulina, Russell F. Howe, and Graine Moran. "FTIR AND NMR STUDIES OF ADSORBED CETHYLTRIMETHYLAMMONIUM CHLORIDE IN MCM-41 MATERIALS." Indonesian Journal of Chemistry 8, no. 1 (June 17, 2010): 1–6. http://dx.doi.org/10.22146/ijc.21639.
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The high use of surface-active agents (surfactants) by industry and households today leads to environmental pollution, therefore treatments are required to remove such substances from the environment. One of the important and widely used methods for removal of substances from solution is adsorption. In this research, MCM-41 and its modified product of MCM41-TMCS were used to adsorb cationic surfactants, cethyltrimethylammonium chloride, CTAC. FTIR and NMR methods were used to study the interaction between the surfactants and the adsorbents. MCM-41 was synthesized hydrothermally at 100 oC and its modification was conducted by silylation of MCM-41 with trimethylchloro silane (MCM41-TMCS). Both unmodified and modified MCM-41 can adsorb the surfactant. The interaction of CTAC with MCM-41 was mostly the electrostatic interaction between the electropositive end of the surfactant and MCM-41, whereas in modified MCM-41 hydrophobic interactions become more dominant. These hydrophobic interactions appear however to involve the methyl groups on the head group of the surfactant interacting with the modified surface. Keywords: FTIR, NMR, adsorbed CTAC, MCM-41 materials
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Evans, T. R. Jeffry, Antoine Italiano, Ferry Eskens, Stefan Nicholas Symeonides, Alice Susannah Bexon, Philippa Graham, David Hinds, et al. "Phase 1-2 study of TI-061 alone and in combination with other anti-cancer agents in patients with advanced malignancies." Journal of Clinical Oncology 35, no. 15_suppl (May 20, 2017): TPS3109. http://dx.doi.org/10.1200/jco.2017.35.15_suppl.tps3109.
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TPS3109 Background: The cell surface protein CD47 is expressed or over-expressed on many tumor types. CD47 binds to signal regulatory protein alpha (SIRPα) on macrophages resulting in a “don’t eat me” signal that blocks host cell phagocytosis of the tumor cells, thus allowing them to escape removal by the innate immune system. Recent data indicate that anti-CD47 antibodies also contribute to an effective anti-tumor T cell response in immune-competent mice. Therefore, anti-CD47 antibodies are a new class of immune checkpoint inhibitors that modulate both the innate and adaptive immune systems. Ti-061 is a novel IgG4 humanized monoclonal antibody that specifically binds to CD47 with Kd values range from 100 – 500 pM. Ti-061 exhibits cross-species binding to cynomolgus monkey, mouse and rat CD47, enabling efficacy and toxicity testing across species. Ti-061 binds to CD47 on RBCs; however, it does not cause agglutination of RBCs in vitro from any of the species tested. Ti-061 exhibits anti-tumor activity in several in vivo mouse tumor models. This ongoing Phase 1-2 study will assess the safety, efficacy, pharmacokinetics (PK) and pharmacodynamics (PD) of Ti-061 alone and in combination with other anti-cancer agents in patients with advanced malignancies. Methods: Part A is an open-label, dose-escalation study of Ti-061 administered as a weekly 1-hour IV infusion at doses ranging from 1 to 20 mg/kg. Once the MTD/RP2D or “active dose” is determined, patients with specific solid tumors and high CD47 expression will be enrolled in 4 or more expansion cohorts. Up to 160 patients with histologically confirmed solid tumors, ECOG PS 0-1, adequate blood counts (Hb≥ 10 g/dL), organ function, and archival or fresh tumor tissue will be enrolled in Part A, and will be treated until disease progression, unacceptable toxicity, or withdrawal. Primary endpoint is safety, which will be assessed using NCI-CTCAE v4.03. Secondary endpoints include PK, PD, objective response rate (ORR) and progression-free survival (PFS), which will be assessed using RECIST v1.1. The results of this study will support further development of Ti-061 in combination with checkpoint inhibitors (Part B) and other anti-cancer agents.
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Johnson, F. E., Y. Wang, T. Ling, S. Chuang, S. S. Huang, and J. S. Huang. "Synthetic TGF-ß antagonist promotes healing of injured epithelial surfaces." Journal of Clinical Oncology 24, no. 18_suppl (June 20, 2006): 18586. http://dx.doi.org/10.1200/jco.2006.24.18_suppl.18586.
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18586 Background: Cancer treatment often results in injury to epithelial surfaces. These injuries are often symptomatic and can delay or prevent further treatment. Since transforming growth factor-1 (TGF-ß) mediates inflammation, fibrosis, and epithelial mitogenesis, agents modulating TGF-ß may be useful in treating such wounds. We synthesized a dodecapeptide containing the active site of human TGF-ß. It is a TGF-ß antagonist in vitro. We investigated whether application to cutaneous wounds might promote epithelialization and decrease scarring by directly blocking local TGF-ß activity. Methods: We applied synthetic TGF-ß antagonist (1.5 mM in gel carrier, topically), with gel-only and no-treatment controls, to 6 standardized thermal burn wounds in each of 4 pigs. Wounds were measured and photographed for 41 d., then excised. Wound dimensions and percent epithelialization were calculated from photographs. Scar volume was estimated as surface area (photographs) x depth (microscopy). Statistical analysis employed student’s t-test. Additional experiments utilized skin excision wounds in rabbits and pigs. Recombinant TGF-ß and platelet-derived growth factor (PDGF) were applied to identical wounds in other pigs and rabbits in parallel experiments as additional controls. Results: In TGF-ß antagonist-treated pig burn wounds, epithelialization was complete on d. 26 ± 2 (mean ± SD); control wounds were 70 ± 10% re-epithelialized by d. 26 (p < 0.001). Contraction rate, collagen and fibronectin content, and scar volume were all significantly less in treated wounds. TGF- ß and PDGF each retarded wound epithelialization. Conclusions: Treatment of standard skin wounds with a synthetic TGF-ß antagonist promotes epithelialization in a whole-animal model. This agent may be useful in human epithelial injuries due to chemotherapy or radiation. No significant financial relationships to disclose.
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Іванніков, Роман, Ірина Лагута, Оксана Ставинська, and Людмила Буюн. "DEVELOPMENT OF PROTOTYPES OF THERAPEUTIC AND PROPHYLACTIC ANTIOXIDANT AGENTS BASED ON NATURAL BIOLOGICALLY ACTIVE COMPOUNDS OF TROPICOGENIC REPRESENTATIVES OF ORCHIDACEAE JUSS." Science and Innovation 17, no. 1 (March 3, 2021): 89–95. http://dx.doi.org/10.15407/scine17.01.089.
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Introduction. Plant extracts and bioactive substances (BAS) of natural origin possess a high biological activity and a low toxicity, therefore they are widely used in cosmetic, pharmaceutical, and food industries. Problem Statement. Nowadays, about 50% of all medical drugs, dietary supplements, and herbal medicines is produced from natural sources, so the search for plants with a high content of BAS, the development of biotechnologies for BAS production, and the design of composites providing the most effective use of BAS are of great importance. Purpose. The purpose is to study tropical orchid collection for identification of plants with a high BAS content; to develop a procedure for growing promising species in vitro; to design drug prototypes on the basis of plants extracts, nanosized silica, and gelatin biopolymer. Materials and Methods. The extracts prepared from orchids leaves, silica, and gelatin have been used as auxiliary components for composites synthesis. Spectrophotometric, chromatographic, quantum-chemical, anatomo-morphological, physiological-biochemical, and biotechnological methods have been used in the research. Results. The species of orchids, which contain a significant amount of BAS with high antioxidant properties have been identified, the main components of orchids extracts have been distinguished. Sterile cultures of selected species have been obtained; protocols for their cultivation in vitro have been developed. Two types of bioactive composites have been prepared; the interaction of extracts components with silica surface and gelatin molecules has been studied. It has been shown that the materials composed of silica and orchid extracts possess a high storage stability and a prolonged desorption of several BAS, while the materials based on extracts, silica, and gelatin ensure gradual release of all the extracts components. Conclusions. The orchids are valuable sources of natural antioxidants. The designed composites are promising in terms of producing drug formulations for prolonged release of antioxidants.
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Angarita-Rodríguez, Andrea, Diego Quiroga, and Ericsson Coy-Barrera. "Indole-Containing Phytoalexin-Based Bioisosteres as Antifungals: In Vitro and In Silico Evaluation against Fusarium oxysporum." Molecules 25, no. 1 (December 21, 2019): 45. http://dx.doi.org/10.3390/molecules25010045.
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There is a continuous search for more reliable and effective alternatives to control phytopathogens through different strategies. In this context, indole-containing phytoalexins are stimuli-induced compounds implicated in plant defense against plant pathogens. However, phytoalexins’ efficacy have been limited by fungal detoxifying mechanisms, thus, the research on bioisosteres-based analogs can be a friendly alternative regarding the control of Fusarium phytopathogens, but there are currently few studies on it. Thus, as part of our research on antifungal agents, a set of 21 synthetic indole-containing phytoalexin analogs were evaluated as inhibitors against the phyopathogen Fusarium oxysporum. Results indicated that analogs of the N,N-dialkylthiourea, N,S-dialkyldithiocarbamate and substituted-1,3-thiazolidin-5-one groups exhibited the best docking scores and interaction profiles within the active site of Fusarium spp. enzymes. Vina scores exhibited correlation with experimental mycelial growth inhibition using supervised statistics, and this antifungal dataset correlated with molecular interaction fields after CoMFA. Compound 24 (tert-butyl (((3-oxo-1,3-diphenylpropyl)thio)carbonothioyl)-l-tryptophanate), a very active analog against F. oxysporum, exhibited the best interaction with lanosterol 14α-demethylase according to molecular docking, molecular dynamics and molecular mechanic/poisson-boltzmann surface area (MM/PBSA) binding energy performance. After data analyses, information on mycelial growth inhibitors, structural requirements and putative enzyme targets may be used in further antifungal development based on phytoalexin analogs for controlling phytopathogens.
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Chen, Long, Xinyu Song, Fei Xing, Yanan Wang, Yuanzheng Wang, Zhiyu He, and Li Sun. "A Review on Antimicrobial Coatings for Biomaterial Implants and Medical Devices." Journal of Biomedical Nanotechnology 16, no. 6 (June 1, 2020): 789–809. http://dx.doi.org/10.1166/jbn.2020.2942.
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Biomaterial implants and medical devices have been utilized extensively in medical treatment with the development of modern medicine, especially in orthopaedics and stomatology. Along with their applications, biomaterial-associated infections (BAIs) have grown to be one of the main postoperative complications. Antimicrobial coating strategies have been reported to effectively inhibit bacterial adhesion and proliferation on implant surface, extending their lifespan. In this review, the most topical antimicrobial coating designs have been chosen from literature studies. Their antimicrobial mechanisms and antimicrobial activity assessments in literature studies have been presented and compared. Based on their active ingredients, antimicrobial coatings are categories into (i) inorganic agents, including Ag, Cu, ZnO, MoS2 and nitride compound; (ii) organic agents including antibiotic, antimicrobial peptides, polymer, essential oils etc. The review has provided various and detailed options of antimicrobial coating designs for consulting according to their specific application. It is noted that the research of antimicrobial coatings is mostly in vitro and in vivo animal models study. It is thus in need for more preclinical or clinical studies, especially finding the direct connection between the utilization of antimicrobial coated implants and the reduction in BAIs incidence. Furthermore, future antimicrobial coating designs shall respect also biocompatibility, functionality, and durability apart from their antimicrobial activity.
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Canevari, Gerard P., and Robert J. Fiocco. "CRUDE OIL VANADIUM AND NICKEL CONTENT CAN PREDICT EMULSIFICATION TENDENCY." International Oil Spill Conference Proceedings 1997, no. 1 (April 1, 1997): 309–14. http://dx.doi.org/10.7901/2169-3358-1997-1-309.
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ABSTRACT Most crude oils in contact with water form water-in-oil emulsions. The stability of these emulsions will vary. When spilled crude oil emulsifies, it becomes viscous and expands in volume, becoming more difficult to recover, chemically disperse, or ignite. The ability to better predict the emulsion-forming behavior of a specific crude oil would greatly aid oil spill response decisions. The problem is complex because of the various stabilizing mechanisms. This study identified surface active agents, that is, porphyrins, as key compounds that contribute to the emulsification of crude oil, particularly fresh crude oil. This research not only identified these metal-porphyrin agents but also determined the mechanism for their emulsion stabilization. These porphyrin complexes are known to be associated with the metals vanadium and nickel. Because the vanadium and nickel levels of a specific crude oil are available from its published assay, they can be used to predict the emulsification of oil early in the spill. The study has also established that a concentration level of over 15 ppm of vanadium and nickel is required to form a stable emulsion for fresh crude oil. It should be stressed that the vanadium-nickel index applies to fresh crude oil. A second emulsification mechanism was also observed during this research that was related to the weathering of the crude oil. Extensive data to support this mechanism are presented and may provide a valuable tool for oil spill response.
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Dadashpour, Sakineh, Tuba T. Küçükkılınç, Ayse Ercan, Seyed J. Hosseinimehr, Nima Naderi, and Hamid Irannejad. "Synthesis and Anticancer Activity of Benzimidazole/Benzoxazole Substituted Triazolotriazines in Hepatocellular Carcinoma." Anti-Cancer Agents in Medicinal Chemistry 19, no. 17 (January 24, 2020): 2120–29. http://dx.doi.org/10.2174/1871520619666190808152051.
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Background: Receptor Tyrosine Kinases (RTK) are the main family of cell surface receptors for growth factors, hormones and cytokines which are responsible for cell growth and differentiation and are considered as an important therapeutic target in cancer. Objective: The aim of this study was to design, synthesise and conduct the biological evaluation of benzimidazole/ benzoxazole substituted triazolotriazines as new anticancer agents. Methods: A series of benzimidazolyl and benzoxazolyl-linked triazolotriazines 8a-e and 9a-e were synthesized as receptor tyrosine kinase inhibitors. Target compounds were evaluated in HGF-induced cell proliferation assay in A549, MCF-7, HepG2 and MDA-MB-231 cancer cells. Results: Hepatocellular carcinoma was the most sensitive cell line towards the tested compounds and 8e was the most potent one on HepG2 cells with an IC50 value of 5.13µM which was close to crizotinib (HepG2 IC50 = 4.35µM) as a standard c-Met kinase inhibitor. c-Met kinase assay of 8e showed that this compound is not capable of inhibiting this enzyme and subsequently molecular docking confirmed the low affinity of 8e towards c- Met active site and its possible anticancer mechanism through VEGFR-2 inhibition. Conclusion: Further in silico predictions revealed that 8e can be a drug candidate with favorable pharmacokinetic properties.
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Fernandes, Fiona, Pooja Kotharkar, Adrija Chakravorty, Meenal Kowshik, and Indrani Talukdar. "Nanocarrier Mediated siRNA Delivery Targeting Stem Cell Differentiation." Current Stem Cell Research & Therapy 15, no. 2 (March 26, 2020): 155–72. http://dx.doi.org/10.2174/1574888x14666191202095041.
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Stem cell-based regenerative medicine holds exceptional therapeutic potential and hence the development of efficient techniques to enhance control over the rate of differentiation has been the focus of active research. One of the strategies to achieve this involves delivering siRNA into stem cells and exploiting the RNA interference (RNAi) mechanism. Transport of siRNA across the cell membrane is a challenge due to its anionic property, especially in primary human cells and stem cells. Moreover, naked siRNA incites immune responses, may cause off-target effects, exhibits low stability and is easily degraded by endonucleases in the bloodstream. Although siRNA delivery using viral vectors and electroporation has been used in stem cells, these methods demonstrate low transfection efficiency, cytotoxicity, immunogenicity, events of integration and may involve laborious customization. With the advent of nanotechnology, nanocarriers which act as novel gene delivery vehicles designed to overcome the problems associated with safety and practicality are being developed. The various nanomaterials that are currently being explored and discussed in this review include liposomes, carbon nanotubes, quantum dots, protein and peptide nanocarriers, magnetic nanoparticles, polymeric nanoparticles, etc. These nanodelivery agents exhibit advantages such as low immunogenic response, biocompatibility, design flexibility allowing for surface modification and functionalization, and control over the surface topography for achieving the desired rate of siRNA delivery and improved gene knockdown efficiency. This review also includes discussion on siRNA co-delivery with imaging agents, plasmid DNA, drugs etc. to achieve combined diagnostic and enhanced therapeutic functionality, both for in vitro and in vivo applications.
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Khan, Ghouse, Swamy Sreenivasa, Shivaraja Govindaiah, and Vivek Chandramohan. "Benzyl and Sulfonyl Derivatives of N-(2,6-dimethylphenyl)-2-(piperazin-1-yl)acetamide (T2288): Biological Screening and Fingerprint applications." Oriental Journal of Chemistry 35, no. 1 (February 6, 2019): 157–66. http://dx.doi.org/10.13005/ojc/350117.
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A series of five N-(2,6-dimethylphenyl)-2-(piperazin-1-yl)acetamide (T2288) sulfonamides 6a-e and its five alkylated piperazine derivatives 8a-e have been synthesized, characterized and screened for antibacterial, antifungal and anthelmintic activity. Some of the compounds showed significant biological activities. Molecular docking to crystal structures of target proteins revealed that, active compounds show similar binding poses as that of standards, indicating good correlation of the binding energy with observed invitro data for the active compounds. Finally, the study of latent fingerprint analysis showed that the compound 6c exhibits good stickiness and finger rhythm without dense dust. The resulting compound can be used to detect fingerprints on all types of flat surfaces and hence easily accepted for detecting hidden fingerprints. This research can offer an excellent setting that can lead to the discovery of potential antibacterial, antifungal, anthelmintic and fingerprint agents.
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Costagliola di Polidoro, Angela, Agnese Grassia, Francesca De Sarno, Paolo Bevilacqua, Valentina Mollo, Eugenia Romano, Maria Donata Di Taranto, et al. "Targeting Nanostrategies for Imaging of Atherosclerosis." Contrast Media & Molecular Imaging 2021 (March 31, 2021): 1–10. http://dx.doi.org/10.1155/2021/6664471.
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Despite the progress in cardiovascular research, atherosclerosis still represents the main cause of death worldwide. Clinically, the diagnosis of Atherosclerotic Cardiovascular Disease (ASCVD) relies on imaging methodologies including X-ray angiography and computed tomography (CT), which however still fails in the identification of patients at high risk of plaque rupture, the main cause of severe clinical events as stroke and heart attack. Magnetic resonance imaging, which is characterized by very high spatial resolution, could provide a better characterization of atherosclerotic plaque (AP) anatomy and composition, aiding in the identification of “vulnerable” plaques. In this context, hydrogel matrices, which have been demonstrated able to boost relaxometric properties of Gd-based contrast agents (CAs) by the effect of Hydrodenticity, represent a valuable tool towards the precision imaging of ASCVD improving the performance of this class of CAs while reducing systemic toxicity. In particular, hydrogel nanoparticles encapsulating Gd-DTPA can further contribute to providing CA-specific accumulation in the AP by nanoparticle surface decoration triggering an active targeting of the AP with the overall effect of allowing an earlier and more accurate diagnosis. In this work, we tested crosslinked Hyaluronic Acid Nanoparticles (cHANPs) in the complex environment of human atherosclerotic plaque. In addition, the surface of cHANPs was decorated with the antibody anti-CD36 (Ab36-cHANPs) for the active targeting of AP-associated macrophages. Results demonstrate that the Hydrodenticity of cHANPs and Ab36-cHANPs is preserved in this complex system and, preliminarily, that interaction of these probes with the AP is present.