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Caspers, Patrick, Luc Bury, Bérangère Gaucher, Jutta Heim, Stuart Shapiro, Sibylle Siegrist, Anne Schmitt-Hoffmann, Laure Thenoz et Heinrich Urwyler. « In Vitro and In Vivo Properties of Dihydrophthalazine Antifolates, a Novel Family of Antibacterial Drugs ». Antimicrobial Agents and Chemotherapy 53, no 9 (22 juin 2009) : 3620–27. http://dx.doi.org/10.1128/aac.00377-09.
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ABSTRACT Racemic 2,4-diaminopyrimidine dihydrophthalazine derivatives BAL0030543, BAL0030544, and BAL0030545 exhibited low in vitro MICs toward small, selected panels of Enterococcus faecalis, Enterococcus faecium, Streptococcus pneumoniae, Moraxella catarrhalis, and Mycobacterium avium, though the compounds were less active against Haemophilus influenzae. The constellation of dihydrofolate reductases (DHFRs) present in 20 enterococci and 40 staphylococci was analyzed and correlated with the antibacterial activities of the dihydrophthalazines and trimethoprim. DHFRs encoded by dfrB, dfrA (S1 isozyme), dfrE, and folA were susceptible to the dihydrophthalazines, whereas DHFRs encoded by dfrG (S3 isozyme) and dfrF were not. Studies with the separated enantiomers of BAL0030543, BAL0030544, and BAL0030545 revealed preferential inhibition of susceptible DHFRs by the (R)-enantiomers. BAL0030543, BAL0030544, and BAL0030545 were well tolerated by mice during 5- and 10-day oral toxicity studies at doses of up to 400 mg/kg of body weight. Using a nonoptimized formulation, the dihydrophthalazines displayed acceptable oral bioavailabilities in mice, and efficacy studies with a septicemia model of mice infected with trimethoprim-resistant, methicillin-resistant Staphylococcus aureus gave 50% effective dose values in the range of 1.6 to 6.25 mg/kg.
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Hamid, Aabid, Atul Anand et Ram Kinkar Roy. « The charge transfer limit of a chemical adduct : the role of perturbation on external potential ». Physical Chemistry Chemical Physics 19, no 17 (2017) : 10905–12. http://dx.doi.org/10.1039/c7cp01208j.
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Liu, Li, et Ji Chun Tan. « Multiple Watermarks Embedding Simultaneously to Identify Image Status Based on Fractional Fourier Transform ». Advanced Materials Research 341-342 (septembre 2011) : 758–62. http://dx.doi.org/10.4028/www.scientific.net/amr.341-342.758.
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A new method of multiple watermarks embedding simultaneously to identify image status based on once and twice discrete fractional Fourier transform (DFRT) is presented. Random series watermark, chirp watermark and annotation watermark are embedded simultaneously in fractional Fourier transform domain to identify digital tamper detection, scanning detection, duplicate detection. According to the extracting situation of three kinds of watermarks from an image and the twice DFRT amplitude spectrum, we can know whether the image is tampered, scanned or duplicated. It provides a convenient way to identify the status of the image and will be an all-sided and comprehensive anti-counterfeiting technology.
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Saha, Bapan, et Pradip Kr Bhattacharyya. « Understanding reactivity, aromaticity and absorption spectra of carbon cluster mimic to graphene : a DFT study ». RSC Advances 6, no 83 (2016) : 79768–80. http://dx.doi.org/10.1039/c6ra15016k.
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Effect of doping B and/or N on the reactivity, aromaticity and absorption spectra of graphene and functionalized (–OH and –COOH) carbon cluster mimicking graphene is studied using DFT, DFRT and TD-DFT.
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Shishido, E., S. Higashijima, Y. Emori et K. Saigo. « Two FGF-receptor homologues of Drosophila : one is expressed in mesodermal primordium in early embryos ». Development 117, no 2 (1 février 1993) : 751–61. http://dx.doi.org/10.1242/dev.117.2.751.
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The fibroblast growth factor (FGF)/receptor system is thought to mediate various developmental events in vertebrates. We examined molecular structures and expression of DFR1 and DFR2, two Drosophila genes closely related to vertebrate FGF-receptor genes. DFR1 and DFR2 proteins contain two and five immunoglobulin-like domains, respectively, in the extracellular region, and a split tyrosine kinase domain in the intracellular region. In early embryos, DFR1 RNA expression, requiring both twist and snail proteins, is specific to mesodermal primordium and invaginated mesodermal cells. At later stages, putative muscle precursor cells and cells in the central nervous system (CNS) express DFR1. DFR2 expression occurs in endodermal precursor cells, CNS midline cells and certain ectodermal cells such as those of trachea and salivary duct. FGF-receptor homologues in Drosophila would thus appear essential for generation of mesodermal and endodermal layers, invaginations of various types of cells, and CNS formation.
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Choudhary, Nancy, et Boas Pucker. « Conserved amino acid residues and gene expression patterns associated with the substrate preferences of the competing enzymes FLS and DFR ». PLOS ONE 19, no 8 (28 août 2024) : e0305837. http://dx.doi.org/10.1371/journal.pone.0305837.
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Background Flavonoids, an important class of specialized metabolites, are synthesized from phenylalanine and present in almost all plant species. Different branches of flavonoid biosynthesis lead to products like flavones, flavonols, anthocyanins, and proanthocyanidins. Dihydroflavonols form the branching point towards the production of non-colored flavonols via flavonol synthase (FLS) and colored anthocyanins via dihydroflavonol 4-reductase (DFR). Despite the wealth of publicly accessible data, there remains a gap in understanding the mechanisms that mitigate competition between FLS and DFR for the shared substrate, dihydroflavonols. Results An angiosperm-wide comparison of FLS and DFR sequences revealed the amino acids at positions associated with the substrate specificity in both enzymes. A global analysis of the phylogenetic distribution of these amino acid residues revealed that monocots generally possess FLS with Y132 (FLSY) and DFR with N133 (DFRN). In contrast, dicots generally possess FLSH and DFRN, DFRD, and DFRA. DFRA, which restricts substrate preference to dihydrokaempferol, previously believed to be unique to strawberry species, is found to be more widespread in angiosperms and has evolved independently multiple times. Generally, angiosperm FLS appears to prefer dihydrokaempferol, whereas DFR appears to favor dihydroquercetin or dihydromyricetin. Moreover, in the FLS-DFR competition, the dominance of one over the other is observed, with typically only one gene being expressed at any given time. Conclusion This study illustrates how almost mutually exclusive gene expression and substrate-preference determining residues could mitigate competition between FLS and DFR, delineates the evolution of these enzymes, and provides insights into mechanisms directing the metabolic flux of the flavonoid biosynthesis, with potential implications for ornamental plants and molecular breeding strategies.
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Gibreel, Amera, et Ola Sköld. « High-Level Resistance to Trimethoprim in Clinical Isolates of Campylobacter jejuni by Acquisition of Foreign Genes (dfr1 and dfr9) Expressing Drug-Insensitive Dihydrofolate Reductases ». Antimicrobial Agents and Chemotherapy 42, no 12 (1 décembre 1998) : 3059–64. http://dx.doi.org/10.1128/aac.42.12.3059.
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ABSTRACT The pathogenic bacterium Campylobacter jejuni has been regarded as endogenously resistant to trimethoprim. The genetic basis of this resistance was characterized in two collections of clinical isolates of C. jejuni obtained from two different parts of Sweden. The majority of these isolates were found to carry foreigndfr genes coding for resistant variants of the dihydrofolate reductase enzyme, the target of trimethoprim. The resistance genes, found on the chromosome, were dfr1 anddfr9. In about 10% of the strains, the dfr1and dfr9 genes occurred simultaneously. About 10% of the examined isolates were found to be negative for these dfrgenes and showed a markedly lower trimethoprim resistance level than the other isolates. The dfr9 and dfr1 genes were located in the context of remnants of a transposon and an integron, respectively. Two different surroundings for thedfr9 gene were characterized. One was identical to the right-hand end of the transposon Tn5393, and in the other, the dfr9 gene was flanked by only a few nucleotides of a Tn5393 sequence. The insertion of the dfr9 gene into the C. jejuni chromosome could have been mediated by Tn5393. The frequent occurrence of high-level trimethoprim resistance in clinical isolates of C. jejuni could be related to the heavy exposure of food animals to antibacterial drugs, which could lead to the acquisition of foreign resistance genes in naturally transformable strains of C. jejuni.
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Hamza, Rafik, Alzubair Hassan, Teng Huang, Lishan Ke et Hongyang Yan. « An Efficient Cryptosystem for Video Surveillance in the Internet of Things Environment ». Complexity 2019 (9 décembre 2019) : 1–11. http://dx.doi.org/10.1155/2019/1625678.
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Surveillance systems paradigm envisions the pervasive interconnection and cooperation of interactive devices over the Internet infrastructure. Nevertheless, dissemination and processing of surveillance video amid the Internet of Things (IoT) applications become a susceptible issue due to the large volume and the significant information of these data. Moreover, surveillance devices on IoT have very limited resources such as memory and storage. The actual security methods are not quite appropriate for surveillance IoT systems. Thus, a particular cryptosystem technique is required for surveillance data security. In this paper, we propose an efficient cryptosystem to secure IoT-based surveillance systems. The proposed cryptosystem framework contains three parts. First, a lightweight automatic summarization technique based on a fast histogram-clustering approach is used to extract the keyframes from the surveillance video. Then, we employ a discrete cosine transform (DCT) technique to compress the extracted data size. Finally, the proposed framework performs an efficient image encryption algorithm by employing a discrete fractional random transform (DFRT). The testing results and analysis confirm the features of the proposed cryptosystem on surveillance systems. The proposed framework is fast and ensures secure and efficient real-time processing by minimizing the transmission cost and storage.
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Liu, Xifeng, Wen Yuan, Chaokang Gu, Wenhao Huang et Weixin Hu. « Nature of Sigma-Type Lithium Bonding Interaction in Nanoscale ». Nano LIFE 04, no 04 (décembre 2014) : 1441020. http://dx.doi.org/10.1142/s1793984414410207.
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Li-based rechargeable batteries are becoming popular power sources for biomedical devices and healthcare equipment. In nanoscale, lithium bonds may associate with intermolecular noncovalent interactions when Li atoms are shared by adjacent atoms inside rechargeable Li batteries. Theoretical study of lithium boding interactions thus is of paramount importance for a better understanding of the working mechanisms and designing high-efficient electrode–electrolyte interfaces from nanolevel for Li-based batteries. In this study, we used state-of-the-art theoretical methods, with inclusion of density functional theory/symmetry-adapted perturbation theory (DFT/SAPT), density functional reactivity theory (DFRT) and energy decomposition analysis (EDA), to delve into the nature of lithium bonding interactions. Our results showed that B3LYP outperforms all other functionals under consideration in the conventional supramolecular scheme, indicating that the formation of a lithium bond is not dispersion-driven. The calculated PBE0/SAPT and B3LYP/EDA data are consistent with each other, unravelling that the lithium bond is mainly of an electrostatically driven nature. Both steric hindrance and exchange-correlation potentials also make important contributions when two-variable fitting is considered. These results provide new sight in understanding lithium atom interactions for potential lithium-based batteries applications.
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Bergmann, René, Mark van der Linden, Gursharan S. Chhatwal et D. Patric Nitsche-Schmitz. « Factors That Cause Trimethoprim Resistance in Streptococcus pyogenes ». Antimicrobial Agents and Chemotherapy 58, no 4 (3 février 2014) : 2281–88. http://dx.doi.org/10.1128/aac.02282-13.
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ABSTRACTThe use of trimethoprim in treatment ofStreptococcus pyogenesinfections has long been discouraged because it has been widely believed that this pathogen is resistant to this antibiotic. To gain more insight into the extent and molecular basis of trimethoprim resistance inS. pyogenes, we tested isolates from India and Germany and sought the factors that conferred the resistance. Resistant isolates were identified in tests for trimethoprim or trimethoprim-sulfamethoxazole (SXT) susceptibility. Resistant isolates were screened for the known horizontally transferable trimethoprim-insensitive dihydrofolate reductase (dfr) genesdfrG,dfrF,dfrA,dfrD, anddfrK. The nucleotide sequence of the intrinsicdfrgene was determined for resistant isolates lacking the horizontally transferable genes. Based on tentative criteria, 69 out of 268 isolates (25.7%) from India were resistant to trimethoprim. Occurring in 42 of the 69 resistant isolates (60.9%),dfrFappeared more frequently thandfrG(23 isolates; 33.3%) in India. ThedfrFgene was also present in a collection of SXT-resistant isolates from Germany, in which it was the only detected trimethoprim resistance factor. ThedfrFgene caused resistance in 4 out of 5 trimethoprim-resistant isolates from the German collection. An amino acid substitution in the intrinsic dihydrofolate reductase known from trimethoprim-resistantStreptococcus pneumoniaeconferred resistance toS. pyogenesisolates ofemmtype 102.2, which lacked other aforementioneddfrgenes. Trimethoprim may be more useful in treatment ofS. pyogenesinfections than previously thought. However, the factors described herein may lead to the rapid development and spread of resistance ofS. pyogenesto this antibiotic agent.
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ZHAO, DONGBO, CHUNYING RONG, DULIN YIN et SHUBIN LIU. « MOLECULAR ACIDITY OF BUILDING BLOCKS OF BIOLOGICAL SYSTEMS : A DENSITY FUNCTIONAL REACTIVITY THEORY STUDY ». Journal of Theoretical and Computational Chemistry 12, no 05 (août 2013) : 1350034. http://dx.doi.org/10.1142/s021963361350034x.
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An accurate prediction of the molecular acidity by employing ab initio or density functional approaches for typical molecular systems is still challenging. Recently, we proposed to utilize two quantum descriptors, molecular electrostatic potential (MEP) and the sum of valence natural atomic orbital (NAO) energies on the nucleus of both the acidic atom and leaving proton, to quantitatively evaluate the pKa values. This new approach has been validated by a number of organic and inorganic systems and justified within the framework of density functional reactivity theory (DFRT). In this work, we apply the approach to building blocks of biological systems, namely, 20 natural α-amino acids and 5 DNA/RNA bases, together with a few other biologically relevant species. Our results show that there exists a strong linear correlation between MEP on the nucleus of the N atom and the sum of N 2p NAO energies, with the correlation coefficient R2 = 0.99. Also, we observe that both MEP on the nitrogen nucleus and the sum of N 2p NAO energies correlate well with experimental pKa values, with the correlation coefficient equal to 0.91. Using this established model, we predicted the trend of pKa changes of amino acids in proteins with different dielectric constants. We also applied the model to predict pKa values for dipeptides. Implications of these linear relationships to understand functions and reactivity of biological systems are discussed as well.
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Oz, Alon, Shany Hershkovitz, Nataly Belman, Ervin Tal-Gutelmacher et Yoed Tsur. « Analysis of impedance spectroscopy of aqueous supercapacitors by evolutionary programming : Finding DFRT from complex capacitance ». Solid State Ionics 288 (mai 2016) : 311–14. http://dx.doi.org/10.1016/j.ssi.2015.11.008.
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Boukamp, Bernard A., et Aurélie Rolle. « Use of a distribution function of relaxation times (DFRT) in impedance analysis of SOFC electrodes ». Solid State Ionics 314 (janvier 2018) : 103–11. http://dx.doi.org/10.1016/j.ssi.2017.11.021.
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Bar, Nimai, et Rajkamal Pandit. « IMPEDANCE SPECTROSCOPY GENETIC PROGRAMMING (ISGP) ANALYSES SETTING PROPER WORKING CONDITIONS OF A POLYMER ELECTROLYTE MEMBRANE FUEL CELL ». Journal of Advanced Scientific Research 14, no 07 (31 août 2023) : 01–07. http://dx.doi.org/10.55218/jasr.202314701.
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This study demonstrates application of Impedance Spectroscopy Genetic Program (ISGP) for the investigation of a polymer electrolyte membrane fuel cell (PEMFC). It further demonstrates the procedures to optimize the operating conditions of a single cell in a test station. To do that, the effects of temperature, hydrogen/air, and dew point temperature (DPT) on the cell were examined using an Arbin test station. ISGP followed a two-iteration procedure. First, find an out-of-range peak (at high frequencies) that corresponds to the ohmic (series) resistance of the system. Second, finding the models after subtracting the ohmic resistance from the real part of the measured spectrum. This two- step procedure allows solving a Fredholm equation of the second kind with a reasonable accuracy. The resulting peaks making the distribution function of relaxation time (DFRT) were partially assigned to different physical processes in the PEMFCs. ISGP seeks for a distribution of relaxation times that has the form of a peak or a sum of several peaks, assuming the Debye kernel, where each peak is represented by a known analytic function. As a part of the analysis, the peak areas, which correspond to the contribution of the relevant process to the total impedance, were calculated obtaining tendentious behavior depending on the changing environmental parameters. ISGP of PEMFC results in three peaks. The optimized conditions were found to be the ratio of gas flow fuel to air rate 1:7, fuel cell temperature 60°C and dew point temperature 50°C.
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Melo, B. M. G., Francisco J. A. Loureiro, Duncan P. Fagg, L. C. Costa et M. P. F. Graça. « DFRTtoEIS : An easy approach to verify the consistency of a DFRT generated from an impedance spectrum ». Electrochimica Acta 366 (janvier 2021) : 137429. http://dx.doi.org/10.1016/j.electacta.2020.137429.
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Belkić, Dževad, et Karen Belkić. « In vivo derivative NMR spectroscopy for simultaneous improvements of resolution and signal-to-noise-ratio : Case study, Glioma ». Journal of Mathematical Chemistry 59, no 9 (19 août 2021) : 2133–78. http://dx.doi.org/10.1007/s10910-021-01280-0.
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AbstractThe theme of this study is derivative nuclear magnetic resonance (dNMR) spectroscopy. This versatile methodology of peering into the molecular structure of general matter is common to e.g. analytical chemistry and medical diagnostics. Theoretically, the potential of dNMR is huge and the art is putting it into practice. The implementation of dNMR (be it in vitro or in vivo) is wholly dependent on the manner in which the encoded time signals are analyzed. These acquired data contain the entire information which is, however, opaque in the original time domain. Their frequency-dependent dual representation, a spectrum, can be transparent, provided that the appropriate signal processors are used. In signal processing, there are shape and parameter estimators. The former processors are qualitative as they predict only the forms of the lineshape profiles of spectra. The latter processors are quantitative because they can give the peak parameters (positions, widths, heights, phases). Both estimators can produce total shape spectra or envelopes. Additionally, parameter estimators can yield the component spectra, based on the reconstructed peak quantifiers. In principle, only parameter estimators can solve the quantification problem (harmonic inversion) to determine the structure of the time signal and, hence, the quantitative content of the investigated matter. The derivative fast Fourier transform (dFFT) and the derivative fast Padé transform (dFPT) are the two obvious candidates to employ for dNMR spectroscopy. To make fair comparisons between the dFFT and dFPT, the latter should also be applied as a shape estimator. This is what is done in the present study, using the time signals encoded from a patient with brain tumor (glioma) using a 1.5T clinical scanner. Moreover, within the dFPT itself, the shape estimations are compared to the parameter estimations. The goal of these testings is to see whether, for in vivo dNMR spectroscopy, shape estimations by the dFPT could quantify (without fitting), similarly to parameter estimations. We check this key point in two successive steps. First, we compare the envelopes from the shape and parameter estimations in the dFPT. The second comparison is between the envelopes and components from the shape and parameter estimations, respectively, in the dFPT. This plan for benchmarking shape estimations by the dFPT is challenging both on the level of data acquisition and data analysis. The data acquisition reported here provides encoded time signals of short length, only 512 as compared to 2048, which is customarily employed. Moreover, the encoding echo time was long (272 ms) at which most of resonances assigned to metabolites with shorter spin-spin relaxations are likely to be obliterated from the frequency spectra. Yet, in face of such seemingly insurmountable obstacles, we are looking into the possibility to extract diagnostically relevant information, having particularly in focus the resonances for recognized cancer biomarkers, notably lactate, choline and phosphocholine. Further, we want to see how many of the remaining resonances in the spectra could accurately be identified with clinical reliability as some of them could also be diagnostically relevant. From the mathematical stance, we are here shaking the sharp border between shape and parameter estimators. That border stood around for a long time within nonderivative estimations. However, derivative shape estimations have a chance to tear the border down. Recently, shape estimations by the dFPT have been shown to lead such a trend as this processor could quantify using the time signals encoded from a phantom (a test sample of known content). Further, the present task encounters a number of additional challenges, including a low signal-to-noise ratio (SNR) and, of course, the unknown content of the scanned tissue. Nevertheless, we are determined to find out whether the nonparametric dFPT can deliver the unique quantification-equipped shape estimation and, thus, live up to the expectation of derivative processing: a long-sought simultaneous improvement of resolution and SNR. In every facet of in vivo dNMR, we found that shape estimations by the dFPT has successfully passed the outlined most stringent tests. It begins with transforming itself to a parameter estimator (already with the 3rd and 4th derivatives). It ends with reconstructing some 54 well-isolated resonances. These include the peaks assigned to recognized cancer biomarkers. In particular, a clear separation of choline from phosphocholine is evidenced for the first time by reliance upon the dFPT with its shape estimations alone.
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Sarmah, Amrit, et Ram Kinkar Roy. « A density functional reactivity theory (DFRT) based approach to understand the interaction of cisplatin analogues with protecting agents ». Journal of Computer-Aided Molecular Design 28, no 12 (3 septembre 2014) : 1153–73. http://dx.doi.org/10.1007/s10822-014-9790-7.
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Adesoji, Tomiwa Olumide, Beverly Egyir et Adebayo Osagie Shittu. « Antibiotic-resistant staphylococci from the wastewater treatment plant and grey-water samples in Obafemi Awolowo University, Ile-Ife, Nigeria ». Journal of Water and Health 18, no 6 (27 juillet 2020) : 890–98. http://dx.doi.org/10.2166/wh.2020.019.
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Abstract This study examined the occurrence and molecular basis for antibiotic-resistant staphylococci from the wastewater treatment plant and grey-water samples in Obafemi Awolowo University, Nigeria. Standard microbiological techniques and molecular methods were utilized. The species identified (MALDI score >1.7) comprised S. saprophyticus (19), S. cohnii (8), S. sciuri (7), S. aureus (4), S. epidermidis (3), S. warneri (2), S. equorum (1), S. haemolyticus (1), S. nepalensis (1), S. condimenti (1), and S. pasteuri (1). Resistance to trimethoprim, tetracycline and cefoxitin were observed in 78.3% (47/60), 36.7% (22/60) and 25% (15/60) of the isolates, respectively. The rate of multidrug resistance was 53.3% (32/60) and observed in eight species from different sampling sites. Seven (S. sciuri; n = 5; S. aureus; n = 1; S. warneri; n = 1) of the 20 selected (representing the various staphylococcal species and antibiotypes) isolates were mecA-positive. Furthermore, the tetK gene was detected in nine isolates, six with dfrA, and four were positive for the dfrG gene. One S. aureus was mecA, tetK and dfrG gene positive. The study provides insights on antibiotic-resistant staphylococci from a non-clinical setting and highlights the need for active surveillance to understand the burden of antimicrobial resistance in Nigeria. This is key to improve synergy across the human, animal and environmental health sectors in Nigeria.
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Bardasheva, Alevtina, Artem Tikunov, Yuliya Kozlova, Elena Zhirakovskaia, Valeriya Fedorets, Natalya Fomenko, Tatyana Kalymbetova et al. « Antibiotic Resistance and Pathogenomics of Staphylococci Circulating in Novosibirsk, Russia ». Microorganisms 9, no 12 (30 novembre 2021) : 2487. http://dx.doi.org/10.3390/microorganisms9122487.
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A total of 394 strains of staphylococci found in humans and pets in Novosibirsk, Siberian Russia, were characterized in terms of antibiotic resistance and corresponding genes. Two coagulase-positive and 17 coagulase-negative species were identified. The majority of isolates, with the exception of S. haemolyticus and hospital S. epidermidis isolates, were sensitive to most of the tested antibiotics, and isolates from pets displayed the lowest level of resistance. Nevertheless, methicillin-resistant (MRS) and/or multidrug-resistant (MDR) isolates were found in all prevailed species, including coagulase-negative. A set of genes corresponding to the detected resistance was identified: mecA (beta-lactam resistance), aac(6′)-Ie-aph(2″)-Ia, aph(3′)-IIIa, ant(4′)-Ia (aminoglycoside-modifying enzymes), ermA/ermC, and msrA (macrolide resistance). Complete genome analysis for ten MDR S. epidermidis and five MDR S. haemolyticus isolates revealed additional antibiotic resistance genes mphC, qacA/qacB, norA, dfrC/dfrG, lnuA, BseSR, and fosB. NorA, dfrC, and fosB were present in all S. epidermidis genomes, whereas mphC and msrA were identified in all S. haemolyticus ones. All investigated MDR S. epidermidis and four of five S. haemolyticus strains were moderate or strong biofilm producers, whereas multiple genes responsible for this function and for virulence and pathogenicity were identified mostly in S. epidermidis, but were less frequently represented in S. haemolyticus.
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Ishioka, Shigeki, Takashi Hosokawa, Taro Ikeda, Noriyoshi Konuma, Hide Kaneda, Kensuke Ohashi, Takeshi Furuya et al. « Therapeutic potential of mature adipocyte-derived dedifferentiated fat cells for inflammatory bowel disease ». Pediatric Surgery International 36, no 7 (24 mai 2020) : 799–807. http://dx.doi.org/10.1007/s00383-020-04681-5.
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Abstract Purpose Our previous studies demonstrated that mature adipocyte-derived dedifferentiated fat (DFAT) cells possess similar multipotency as mesenchymal stem cells. Here, we examined the immunoregulatory potential of DFAT cells in vitro and the therapeutic effect of DFAT cell transplantation in a mouse inflammatory bowel disease (IBD) model. Methods The effect of DFAT cell co-culture on T cell proliferation and expression of immunosuppression-related genes in DFAT cells were evaluated. To create IBD, CD4+CD45RBhigh T cells were intraperitoneally injected into SCID mice. One week later, DFAT cells (1 × 105, DFAT group) or saline (Control group) were intraperitoneally injected. Subsequently bodyweight was measured every week and IBD clinical and histological scores were evaluated at 5 weeks after T cell administration. Results The T cell proliferation was inhibited by co-cultured DFAT cells in a cell density-dependent manner. Gene expression of TRAIL, IDO1, and NOS2 in DFAT cells was upregulated by TNFα stimulation. DFAT group improved IBD-associated weight loss, IBD clinical and histological scores compared to Control group. Conclusion DFAT cells possess immunoregulatory potential and the cell transplantation promoted recovery from colon damage and improved clinical symptoms in the IBD model. DFAT cells could play an important role in the treatment of IBD.
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Shishido, E., N. Ono, T. Kojima et K. Saigo. « Requirements of DFR1/Heartless, a mesoderm-specific Drosophila FGF-receptor, for the formation of heart, visceral and somatic muscles, and ensheathing of longitudinal axon tracts in CNS ». Development 124, no 11 (1 juin 1997) : 2119–28. http://dx.doi.org/10.1242/dev.124.11.2119.
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DFR1 encodes a mesoderm-specific fibroblast growth factor receptor in Drosophila. Here, we identified and characterized a protein-null mutant of DFR1 and examined DFR1 expression in embryos using anti-DFR1 antibody. Mutant phenotypes were completely rescued by a genomic fragment from the DFR1 locus. After invagination, mesodermal cells expressing DFR1 undergo proliferation and spread out dorsally to form a monolayer beneath the ectoderm. In mutant embryos, however, the mesoderm is not capable of extending to the normal dorsal limit and consequently mesodermal cells fail to receive ectodermal signals and thus rendered incapable of differentiating into primordia for the heart, visceral and somatic muscles. DFR1 is also required for normal development of the central nervous system. The absence of DFR1 resulted in the failure of longitudinal glia to enwrap longitudinal axon tracts. DFR1 mutant phenotypes were partially mimicked by the targeted expression of activated Yan, thus demonstrating the MAP kinase pathway to be involved in differentiation of mesoderm.
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Goriachuk, V. F., et D. F. Dukov. « INSTITUTIONAL PROVISION INVESTMENT INSTRUMENTS OF PUBLIC ADMINISTRATION REGIONAL DEVELOPMENT ». Economic innovations 19, no 3(65) (19 décembre 2017) : 47–55. http://dx.doi.org/10.31520/ei.2017.19.3(65).47-55.
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During the years of independence in Ukraine, a certain set of investment instruments of state governance for regional development has been created: state and regional target programs, regional development agreements, agreements on implementation of interregional projects, programs for overcoming the state of depression, the State Fund for Regional Development (DFRD), and others. However, their level of performance is quite low.Notwithstanding the provisions of the State Strategy for Regional Development for the period up to 2020, regional development agreements and programs to overcome the state of depression of the territory are not implemented at all. The use of the DFRR in the "manual mode" reduces the role of the fund in solving the tasks of regional policy of the state.One of the main investment instruments of state governance for regional development are regional target programs. The analysis of target programs of the Odesa Oblast, which operated in 2015, showed that most of them did not meet the priorities of the economic and social development strategy of the Odessa region and (or) have other defects.Agreements on the implementation of interregional projects, the implementation of which contributes to the improvement of socio-economic development of two or more regions, have not been used at all. The same situation with regard to programs to overcome the state of depression of the territory.The inadequate institutional support of the DFRD leads to its underfunding, non-compliance with the rules for distributing its funds between regions, and non-compliance with the priorities of regional development.The article proposes: to return the practice of using agreements on regional development as a mechanism for coordinating the interests of central executive and local self-government bodies in relation to the implementation of strategic tasks of regional development; based on the principle of subsidiarity, delegate to the regional level the authority to develop programs to overcome the state of depression of the territory; to implement methodological recommendations for the evaluation of regional target programs.
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Coque, Teresa M., Kavindra V. Singh, George M. Weinstock et Barbara E. Murray. « Characterization of Dihydrofolate Reductase Genes from Trimethoprim-Susceptible and Trimethoprim-Resistant Strains ofEnterococcus faecalis ». Antimicrobial Agents and Chemotherapy 43, no 1 (1 janvier 1999) : 141–47. http://dx.doi.org/10.1128/aac.43.1.141.
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Enterococci are usually susceptible in vitro to trimethoprim; however, high-level resistance (HLR) (MICs, >1,024 μg/ml) has been reported. We studied Enterococcus faecalis DEL, for which the trimethoprim MIC was >1,024 μg/ml. No transfer of resistance was achieved by broth or filter matings. Two different genes that conferred trimethoprim resistance when they were cloned in Escherichia coli (MICs, 128 and >1,024 μg/ml) were studied. One gene that coded for a polypeptide of 165 amino acids (MIC, 128 μg/ml forE. coli) was identical to dfr homologs that we cloned from a trimethoprim-susceptible E. faecalis strain, and it is presumed to be the intrinsic E. faecalis dfr gene (which causes resistance in E. coli when cloned in multiple copies); this gene was designated dfrE. The nucleotide sequence 5′ to this dfr gene showed similarity to thymidylate synthetase genes, suggesting that the dfr andthy genes from E. faecalis are located in tandem. The E. faecalis gene that conferred HLR to trimethoprim in E. coli, designated dfrF, codes for a predicted polypeptide of 165 amino acids with 38 to 64% similarity with other dihydrofolate reductases from gram-positive and gram-negative organisms. The nucleotide sequence 5′ to dfrFdid not show similarity to the thy sequences. A DNA probe for dfrF hybridized under high-stringency conditions only to colony lysates of enterococci for which the trimethoprim MIC was >1,024 μg/ml; there was no hybridization to plasmid DNA from the strain of origin. To confirm that this gene causes trimethoprim resistance in enterococci, we cloned it into the integrative vector pAT113 and electroporated it into RH110 (E. faecalisOG1RF::Tn916ΔEm) (trimethoprim MIC, 0.5 μg/ml), which resulted in RH110 derivatives for which the trimethoprim MIC was >1,024 μg/ml. These results indicate thatdfrF is an acquired but probably chromosomally located gene which is responsible for in vitro HLR to trimethoprim in E. faecalis.
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Paul, Tanmoy, Nimrod Yavo, Igor Lubomirsky et Yoed Tsur. « Determination of grain boundary conductivity using distribution function of relaxation times (DFRT) analysis at room temperature in 10 mol% Gd doped ceria : A non-classical electrostrictor ». Solid State Ionics 331 (mars 2019) : 18–21. http://dx.doi.org/10.1016/j.ssi.2018.12.013.
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Sarmah, Amrit, et Ram Kinkar Roy. « A density functional reactivity theory (DFRT) based approach to understand the effect of symmetry of fullerenes on the kinetic, thermodynamic and structural aspects of carbon NanoBuds ». Chemical Physics 472 (juin 2016) : 218–28. http://dx.doi.org/10.1016/j.chemphys.2016.03.006.
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Wang, Huan, Pinghua Li, Taoran Du, Guang Pu, Lijuan Fan, Chen Gao, Peipei Niu, Chengwu Wu, Wuduo Zhou et Ruihua Huang. « Effects of Increasing Levels of Defatted Rice Bran on Intestinal Physical Barrier and Bacteria in Finishing Pigs ». Animals 9, no 12 (28 novembre 2019) : 1039. http://dx.doi.org/10.3390/ani9121039.
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The aims of this study were to assess the effects of increasing levels of DFRB as a replacement for corns on intestinal physical barrier function and bacteria of finishing pigs. A total of 35 castrated finishing pigs (age: 158.5 ± 2.0 d, initial body weight: 62.9 ± 0.8 kg) were randomly divided into five dietary treatments (seven replicates/treatment) for a 28-day experimental period, i.e., a control diet with basal diet, and four experimental diets in which maize was replaced by 7%, 14%, 21%, and 28% DFRB, respectively. The results showed that serum endotoxins concentration and diamine oxidase (DAO) activity were both increased (linear, p = 0.0004, 0.001, respectively) with DFRB level. However, compared with control group, serum endotoxins concentration and DAO activity were not different in pigs fed with 7% DFRB in the diet. There was a quadratic response in serum D-lactate concentration to the increased DFRB (quadratic, p = 0.021). In the cecum, thickness of the intestinal wall significantly increased with increasing levels of DFRB in the diets (linear, p = 0.033), while crypt depth/thickness of the intestinal wall ratio significantly decreased with increasing level of DFRB in the diets (linear, p = 0.043). In the jejunum, total bacteria, Escherichia coli, and Bifidobacterium all responded quadratically to increasing levels of DFRB in the diets (quadratic, p = 0.003, 0.001, 0.006, respectively). Additionally, there was no difference in Escherichia coli in pigs fed 0%, 7%, and 14% DFRB diets. In the colon, there were quadratic responses in C. perfringens to the increased DFRB (quadratic, p = 0.023). C. perfringens reduced as the DFRB concentration increased from 0% to 14% and then increased. When D-lactate, total bacteria, Escherichia coli, Bifidobacterium, and C. perfringens were considered, the optimal substitution level of DFRB were 12.00%, 11.84%, 7.50%, 8.92%, and 15.92%, respectively. In conclusion, 7% DFRB had a beneficial effect on intestinal wall thickness, Bifidobacterium and C. perfringens, and had no adverse effect on intestinal permeability and Escherichia coli.
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Cellier-Goetghebeur, Stella, Kiana Lafontaine, Claudèle Lemay-St-Denis, Princesse Tsamo, Alexis Bonneau-Burke, Janine N. Copp et Joelle N. Pelletier. « Discovery of Highly Trimethoprim-Resistant DfrB Dihydrofolate Reductases in Diverse Environmental Settings Suggests an Evolutionary Advantage Unrelated to Antibiotic Resistance ». Antibiotics 11, no 12 (7 décembre 2022) : 1768. http://dx.doi.org/10.3390/antibiotics11121768.
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Type B dihydrofolate reductases (DfrB) are intrinsically highly resistant to the widely used antibiotic trimethoprim, posing a threat to global public health. The ten known DfrB family members have been strongly associated with genetic material related to the application of antibiotics. Several dfrB genes were associated with multidrug resistance contexts and mobile genetic elements, integrated both in chromosomes and plasmids. However, little is known regarding their presence in other environments. Here, we investigated the presence of dfrB beyond the traditional areas of enquiry by conducting metagenomic database searches from environmental settings where antibiotics are not prevalent. Thirty putative DfrB homologues that share 62 to 95% identity with characterized DfrB were identified. Expression of ten representative homologues verified trimethoprim resistance in all and dihydrofolate reductase activity in most. Contrary to samples associated with the use of antibiotics, the newly identified dfrB were rarely associated with mobile genetic elements or antibiotic resistance genes. Instead, association with metabolic enzymes was observed, suggesting an evolutionary advantage unrelated to antibiotic resistance. Our results are consistent with the hypothesis that multiple dfrB exist in diverse environments from which dfrB were mobilized into the clinically relevant resistome. Our observations reinforce the need to closely monitor their progression.
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Takabatake, Kiyofumi, Masakazu Matsubara, Eiki Yamachika, Yuki Fujita, Yuki Arimura, Kazuki Nakatsuji, Keisuke Nakano, Histoshi Nagatsuka et Seiji Iida. « Comparing the Osteogenic Potential and Bone Regeneration Capacities of Dedifferentiated Fat Cells and Adipose-Derived Stem Cells In Vitro and In Vivo : Application of DFAT Cells Isolated by a Mesh Method ». International Journal of Molecular Sciences 22, no 22 (17 novembre 2021) : 12392. http://dx.doi.org/10.3390/ijms222212392.
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Background: We investigated and compared the osteogenic potential and bone regeneration capacities of dedifferentiated fat cells (DFAT cells) and adipose-derived stem cells (ASCs). Method: We isolated DFAT cells and ASCs from GFP mice. DFAT cells were established by a new culture method using a mesh culture instead of a ceiling culture. The isolated DFAT cells and ASCs were incubated in osteogenic medium, then alizarin red staining, alkaline phosphatase (ALP) assays, and RT-PCR (for RUNX2, osteopontin, DLX5, osterix, and osteocalcin) were performed to evaluate the osteoblastic differentiation ability of both cell types in vitro. In vivo, the DFAT cells and ASCs were incubated in osteogenic medium for four weeks and seeded on collagen composite scaffolds, then implanted subcutaneously into the backs of mice. We then performed hematoxylin and eosin staining and immunostaining for GFP and osteocalcin. Results: The alizarin red-stained areas in DFAT cells showed weak calcification ability at two weeks, but high calcification ability at three weeks, similar to ASCs. The ALP levels of ASCs increased earlier than in DFAT cells and showed a significant difference (p < 0.05) at 6 and 9 days. The ALP levels of DFATs were higher than those of ASCs after 12 days. The expression levels of osteoblast marker genes (osterix and osteocalcin) of DFAT cells and ASCs were higher after osteogenic differentiation culture. Conclusion: DFAT cells are easily isolated from a small amount of adipose tissue and are readily expanded with high purity; thus, DFAT cells are applicable to many tissue-engineering strategies and cell-based therapies.
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Li, Zhi He, Wei Ming Yi, Qiao Chun Gao, Yong Jun Li, Xue Yuan Bai et De Li Zhang. « Research on Pyrolysis Reactors for Bio-Oil Production from Agricultural Residues ». Advanced Materials Research 512-515 (mai 2012) : 459–63. http://dx.doi.org/10.4028/www.scientific.net/amr.512-515.459.
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This paper provides an updated review on fast biomass pyrolysis reactors for bio-oil production in Shandong University of Technology. The technologies that were developed include horizontal entrained bed (HEB), fluidized bed (FB), down flow tuber reactor (DFTR), double concentric cylinder rotary reactor (DCCRR) and new type down flow tube reactor (N-DFTR). The patented DFTR, DCCRR and N-DFTR in China were developed based on the technology of direct heat exchange between hot solid heat carriers and biomass particles during both of the particles flowing in a mixed condition. The process and characteristics of each reactor were discussed in this topic. Contrasting to conventional reactors, the DFTR, DCCRR and N-DFTR are promising technologies due to their characteristics of high solid-liquid conversion rate, energy self-sufficient, easy operation and scaling up.
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Chen, Xiaoshuai, Haiming Yang et Zhiyue Wang. « The Effect of Different Dietary Levels of Defatted Rice Bran on Growth Performance, Slaughter Performance, Serum Biochemical Parameters, and Relative Weights of the Viscera in Geese ». Animals 9, no 12 (28 novembre 2019) : 1040. http://dx.doi.org/10.3390/ani9121040.
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This study investigated the effect of different dietary levels of defatted rice bran (DFRB) on growth performance, slaughter performance, and relative weights of the viscera in geese. A total of 300 28-day-old healthy male Yangzhou goslings with similar body weights were randomly divided into five groups, with six replicates per group and 10 geese per replicate. The geese were fed diets containing 0%, 10%, 20%, 30%, or 40% DFRB for 42 days. Over the 29-d to 70-d trial period, no significant difference was observed in the average daily feed intake in geese (p > 0.05). However, 30% and 40% DFRB reduced body weights of geese at 70 d (p < 0.01) and average daily gain from 28 d to 70 d (p < 0.05) were observed, and 20%, 30%, and 40% DFRB increased feed-to-gain ratios from 28 d to 70 d (p < 0.01). Birds in the 30% and 40% DFRB groups had reduced breast yields (p < 0.05), and birds in the 40% DFRB group had increased thigh yields (p < 0.05). Birds in the 20%, 30%, and 40% DFRB groups had increased proventriculus weights (p < 0.01). The results suggested that a high level of DFRB affected growth performance, slaughter performance, and visceral development. Under the experimental conditions, we recommend that the dietary level of DFRB should not exceed 20% to avoid negative effects on geese.
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Zhao, Yinan, Zhongqing Zhao, Fangqiu Tong, Yu Fan et Xiang Feng. « Modulus Waveform Design Based on Manifold ADMM Idea in Dual-Function Radar–Communication System ». Electronics 13, no 14 (11 juillet 2024) : 2726. http://dx.doi.org/10.3390/electronics13142726.
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In this paper, we try to design the joint waveform and passive beamforming within the context of dual-function radar–communication (DFRC) systems. Focusing on the intricate trade-off between stringent radar beampattern constraints and their desired performance, we introduce a novel manifold idea based on the alternating direction method of multipliers (ADMM) framework. Specifically, our proposed method, named DFRC-MA, could address the challenge of constant modulus waveform design in a multiple-input–multiple-output (MIMO) DFRC system. Firstly, our methodology begins by formulating the reference waveform to achieve an optimal radar beamforming pattern. Subsequently, we define the DFRC optimization problem to mitigate the multi-user interference (MUI) under the constant modulus constraint. Through a series of simulations, we evaluate the efficacy of DFRC-MA, where the integrated waveform designed by DFRC-MA exhibits superior performance over some prevalent ones.
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Huang, Bingbing, Huangwei Shi, Li Wang, Lu Wang, Zhiqian Lyu, Qile Hu, Jianjun Zang, Defa Li et Changhua Lai. « Effects of Defatted Rice Bran Inclusion Level on Nutrient Digestibility and Growth Performance of Different Body Weight Pigs ». Animals 11, no 5 (12 mai 2021) : 1374. http://dx.doi.org/10.3390/ani11051374.
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This study was conducted to determine the effects of low-protein diet prepared with different levels of defatted rice bran (DFRB) and weight stages on growth performance and nutrient digestibility of growing–finishing pigs. The animal experiment included three stages. A total of 240 growing pigs with an initial body weight of 28.06 ± 8.56 kg for stage 1 were allocated to five diets including one control group and four DFRB diets supplemented with 2.5%, 5%, 7.5% and 10% DFRB, respectively. The 192 crossbred pigs with initial body weights of 55.03 ± 7.31 kg and 74.55 ± 9.10 kg were selected for stage 2 and stage 3, respectively. Pigs were allocated to four diets including one control group and three DFRB diets supplemented with 10%, 15% and 20% DFRB, respectively. The results showed that with the increase in DFEB intake, the gain: feed was linearly increased (p < 0.05), and the average daily feed intake tended to linearly decrease (p = 0.06) in stage 1. Except for the apparent total tract digestibility (ATTD) of acid detergent fiber (ADF) in stage 3, levels of DFRB had significant effects on the ATTD of gross energy (GE), dry matter (DM), ash, neutral detergent fiber (NDF) and ADF in three weight stages. In stage 1, with the increase in levels of DFRB, the ATTD of NDF and hemicellulose were firstly increased and then decreased (p < 0.01). In stage 2, with the increasing levels of DFRB, the ATTD of DM, ash and cellulose were firstly increased and then decreased (p < 0.01). In stage 3, the ATTD of GE, DM, ash, NDF and hemicellulose decreased linearly with the increase in levels of DFRB (p < 0.01). Collectively, DFRB could be used as a replacement for corns and soybean meal, and weight stage is important to consider when adjusting the additive proportion.
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Tansriratanawong, Kallapat, Isao Tabei, Hiroshi Ishikawa, Akihiro Ohyama, Junko Toyomura et Soh Sato. « Characterization and comparative DNA methylation profiling of four adipogenic genes in adipose-derived stem cells and dedifferentiated fat cells from aging subjects ». Human Cell 33, no 4 (3 juin 2020) : 974–89. http://dx.doi.org/10.1007/s13577-020-00379-x.
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Abstract Adipose-derived stem cells (ASCs) and dedifferentiated fat (DFAT) cells are alternative cell sources in tissue engineering and regeneration because they are easily obtained and exhibit multilineage differentiation. However, aging may attenuate their regenerative potential and metabolic functions. Reports characterizing DFAT cells derived from aging donors are rare, and comparisons of DNA methylation profiles between aging ASCs and DFAT cells are poorly understood. Therefore, this study aimed to characterize DFAT cells relative to ASCs derived from aging subjects and compare the DNA methylation profiles of four adipogenic genes in these cells. ASCs and DFAT cells from aging donors exhibited characteristics similar to those of stem cells, including colony formation, proliferation, and multilineage differentiation abilities. However, compared with ASCs, DFAT cells exhibited increased proliferation, smooth muscle actin alpha (SMA-α) expression and decreased cellular senescence. DNA methylation profiling of ASCs and DFAT cells by combined bisulfite restriction analysis (COBRA) demonstrated hypermethylation patterns in three potent adipogenic genes—peroxisome proliferator-activated receptor gamma 2 (PPARγ2), fatty acid-binding protein 4 (FABP4), and lipoprotein lipase (LPL)—but hypomethylation of CCAAT/enhancer binding protein alpha (C/EBPα) in the aging group. Statistically significant differences were observed between the aging group and the young group. Epigenetic regulation maintains the stability of ASCs and DFAT cells in an age-dependent manner. Our findings suggested that although the DNA methylation patterns of three adipogenic genes correlated with hypermethylation and aging, ASCs and DFAT cells exhibited cellular stability and several stem cell characteristics, offering further opportunities for personalized regeneration and energy maintenance by adipogenesis during aging.
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Peng, Xuewu, Tongxing Song, Xiaoming Hu, Yuanfei Zhou, Hongkui Wei, Jian Peng et Siwen Jiang. « Phenotypic and Functional Properties of Porcine Dedifferentiated Fat Cells during the Long-Term CultureIn Vitro ». BioMed Research International 2015 (2015) : 1–10. http://dx.doi.org/10.1155/2015/673651.
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It has been proved that terminally differentiated mature adipocytes possess abilities to dedifferentiate into fibroblast-like progeny cells with self-renewal and multiple differentiation, termed dedifferentiated fat (DFAT) cells. However, the biological properties of DFAT cells during long-term culturein vitrohave not been elucidated. Here, we obtained fibroblast-like morphology of porcine DFAT cells by ceiling culture. During the dedifferentiation process, round mature adipocytes with single large lipid droplets changed into spindle-shaped cells accompanied by the adipogenic markersPPARγ,aP2,LPL, andAdiponectinsignificant downregulation. Flow cytometric analysis showed that porcine DFAT cells displayed similar cell-surface antigen profile to mesenchymal stem cells (MSCs). Furthermore, different passages of porcine DFAT cells during long-term culturein vitroretained high levels of cell viabilities (>97%), efficient proliferative capacity including population doubling time ranged from 20 h to 22 h and population doubling reached47.40±1.64by 58 days of culture. In addition, porcine DFAT cells maintained the multiple differentiation capabilities into adipocytes, osteoblasts, and skeletal myocytes and displayed normal chromosomal karyotypes for prolonged passaging. Therefore, porcine DFAT cells may be a novel model of stem cells for studying the functions of gene in the different biological events.
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Wang, Lian Rong, Naoki Ishiguro, Eiji Yamada, Yoshihiro Nishida, Koji Sato et Hisashi Iwata. « The Effect of Da-Fang-Feng-Tang on Treatment of Type II Collagen-induced Arthritis in DBA/1 Mice ». American Journal of Chinese Medicine 27, no 02 (janvier 1999) : 205–15. http://dx.doi.org/10.1142/s0192415x99000240.
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Da-Fang-Feng-Tang (DFFr), which is believed to be effective for treating human rheumatoid arthritis (RA), was given to DBA/1 mice at the onset of type II collagen-induced arthritis (CIA) to examine its effect. Granules of the crude DFFT extract were administered by gastric gavage at a dose of 1.6 g/kg/day for 12 weeks, starting the day CIA began. The levels of anticollagen IgG antibody were significantly decreased in the sera of the DFFT-treated group compared with the control group from weeks 2 to 7 after the onset of CIA. The severity of arthritis in the DFFT-treated group was markedly alleviated when compared with the control group. In addition, histological examination of the DFFT-treated group showed less cartilage and bone erosion. These results suggest that administration of DFFT suppressed the development of CIA in mice and support the belief that DFFT is effective in treating human RA.
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Huang, Bingbing, Li Wang, Zhiqian Lyu, Lu Wang, Jianjun Zang, Defa Li et Changhua Lai. « Evaluation on Net Energy of Defatted Rice Bran from Different Origins and Processing Technologies Fed to Growing Pigs ». Animals 11, no 4 (12 avril 2021) : 1106. http://dx.doi.org/10.3390/ani11041106.
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The study was conducted to determine and compare the net energy (NE) of defatted rice bran (DFRB) from different sources and different processing technology fed to growing pigs using indirect calorimetry. Thirty-six growing barrows (30.7 ± 3.9 kg) were randomly allotted to 1 of 6 diets with 6 replicate pigs per diet. Diets included a corn-soybean meal basal diet and 5 test diets containing 30% DFRB, respectively. These five samples come from 4 different provinces (i.e., Heilongjiang, Jiangsu, Jilin, and Liaoning province within China) and two of them with the same origin but different processing technologies (i.e., extruded or pelleted). During each period, pigs were kept individually in metabolism crates for 21 days, including 14 days to adapt to the diets. On day 15, pigs were transferred to the open-circuit respiration chambers for adaptation, and the next day were ready to determine daily total heat production (HP) and were fed 1 of the 6 diets at 2.3 MJ metabolizable energy (ME)/kg body weight (BW)0.6/day. Total feces and urine were collected for the determination of digestible energy (DE) and ME and daily total HP was measured from day 16 to day 20 and fasted on day 21 for the measurement of fasting heat production (FHP). The NE contents of extruded DFRB from different provinces were within the range of values (8.24 to 10.22 MJ/kg DM). There is a discrepancy of approximately 10.01% in the NE content between the DFRB origins. The NE contents of extruded DFRB and pelleted DFRB from the same province were 8.24 vs. 6.56 MJ/kg DM. Retained energy (RE) and FHP of diets containing extruded DFRB and pelleted DFRB were 1105 vs. 892 kJ/kg BW0.6/day and 746 vs. 726 kJ/kg BW0.6/day respectively, and those in extruded DFRB from different origins were within the range of values (947 to 1105 kJ/kg BW0.6/day and 726 to 755 kJ/kg BW0.6/day, respectively). In conclusion, NE values are affected by origin and processing technology of DFRB.
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Moon, Ji-Hoi, Cheul Kim, Hee-Su Lee, Sung-Woon Kim et Jin-Yong Lee. « Antibacterial and antibiofilm effects of iron chelators against Prevotella intermedia ». Journal of Medical Microbiology 62, no 9 (1 septembre 2013) : 1307–16. http://dx.doi.org/10.1099/jmm.0.053553-0.
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Prevotella intermedia, a major periodontopathogen, has been shown to be resistant to many antibiotics. In the present study, we examined the effect of the FDA-approved iron chelators deferoxamine (DFO) and deferasirox (DFRA) against planktonic and biofilm cells of P. intermedia in order to evaluate the possibility of using these iron chelators as alternative control agents against P. intermedia. DFRA showed strong antimicrobial activity (MIC and MBC values of 0.16 mg ml−1) against planktonic P. intermedia. At subMICs, DFRA partially inhibited the bacterial growth and considerably prolonged the bacterial doubling time. DFO was unable to completely inhibit the bacterial growth in the concentration range tested and was not bactericidal. Crystal violet binding assay for the assessment of biofilm formation by P. intermedia showed that DFRA significantly decreased the biofilm-forming activity as well as the biofilm formation, while DFO was less effective. DFRA was chosen for further study. In the ATP-bioluminescent assay, which reflects viable cell counts, subMICs of DFRA significantly decreased the bioactivity of biofilms in a concentration-dependent manner. Under the scanning electron microscope, P. intermedia cells in DFRA-treated biofilm were significantly elongated compared to those in untreated biofilm. Further experiments are necessary to show that iron chelators may be used as a therapeutic agent for periodontal disease.
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Mo, Rongli, Na Zhang, Jinxin Li, Qiang Jin, Zhixian Zhu, Zhaoxia Dong, Yong Li, Cheng Zhang et Cui Yu. « Transcriptomic Analysis Provides Insights into Anthocyanin Accumulation in Mulberry Fruits ». Horticulturae 8, no 10 (7 octobre 2022) : 920. http://dx.doi.org/10.3390/horticulturae8100920.
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Mulberry fruits are rich in anthocyanins, which are important secondary metabolites that give mulberries their bright color, favorable taste and high nutritional quality, making them a popular fruit. However, few studies have focused on the molecular mechanism underlying anthocyanin accumulation in mulberries and the gene regulatory networks of anthocyanin biosynthetic pathways remain largely unknown. In this study, we performed RNA sequencing to identify differentially expressed genes (DEGs) associated with anthocyanin accumulation between two mulberry genotypes (‘Zi Jing’, ZJ and ‘Zhen Zhu Bai’, ZZB, with purple and white fruit flesh, respectively) at 5, 18, 27 and 31 days after flower. Using transcriptome analysis, we explored several key DEGs involved in the anthocyanin biosynthetic pathway, including the structural genes: CHS, CHI, F3H, DFR1, DFR2 and ANS, known as MBW complex genes: MYB (M.alba_G0017209), MYB (M.alba_G0017689), bHLH (M.alba_G0012659), bHLH (M.alba_G0009347) and bHLH3 (M.alba_G0016257) and the ethylene response factor: ERF (M.alba_G0016603). Of these, changing trends related to expression pattern and anthocyanin content showed their most positive correlation at the post-flowering stage in both genotypes. Our results indicated that ethylene enhances anthocyanin accumulation in mulberry fruits. Furthermore, qRT-PCR was performed to confirm the above-mentioned genes’ expression (except for MYB (M.alba_G0017689) and bHLH (M.alba_G0009347) was significantly up-regulated under ethylene treatment at 300 mg/L. These findings help uncover the gene regulatory networks of the anthocyanin biosynthetic pathway and will contribute to engineering purposes in future mulberry breeding programs.
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Silva, Vanessa, Cláudia Alfarela, Manuela Caniça, Vera Manageiro, Miguel Nóvoa, Belen Leiva, Maria Kress, José Luís Capelo, Patrícia Poeta et Gilberto Igrejas. « A One Health Approach Molecular Analysis of Staphylococcus aureus Reveals Distinct Lineages in Isolates from Miranda Donkeys (Equus asinus) and Their Handlers ». Antibiotics 11, no 3 (10 mars 2022) : 374. http://dx.doi.org/10.3390/antibiotics11030374.
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Donkeys (Equus asinus) are in decline in Europe. Occupational exposure to farm animals has been associated with increased staphylococci carriage. We aimed to isolate S. aureus and coagulase-negative staphylococci (CoNS) from donkeys and handlers and characterize the antimicrobial resistance profiles and genetic lineages of S. aureus strains. Oral and nasal swab samples were collected from 49 Miranda donkeys and 23 handlers from 15 different farms. Staphylococci species were identified by MALDI-TOF MS. The presence of antimicrobial resistance genes and virulence factors was investigated by PCR. Molecular typing was performed in S. aureus isolates. From the 49 donkey samples, 4 S. aureus (8.2%) and 21 CoNS (42.9%) were isolated. Ten handlers (43.5%) were carriers of S. aureus and 4 (17.4%) carried CoNS. The CoNS isolates showed resistance to several classes of antimicrobials encoded by the mecA, aph (3′)-IIIa, ant (4′)-Ia, tetM, tetK, lnuA, ermB, ermC, dfrA and dfrG genes. S. aureus isolates were resistant to penicillin, aminoglicosides and tetracycline harboring the blaZ, aph (3′)-IIIa, tetL, tetM and tetK genes. All S. aureus isolates from donkeys belonged to ST49 and spa-type t208 while the strains isolated from the handlers were ascribed to 3 STs and 7 spa-types. However, human isolates were from different STs than the donkey isolates. Donkeys are mainly colonized by methicillin-resistant S. sciuri. S. aureus transmission between donkeys and their handlers appears not to have occurred since the isolates belonged to different genetic lineages.
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Okoh, G. R., H. M. Kazeem, G. S. N. Kia et S. Mailafia. « Evaluation of Enzyme Linked Immuno-Sorbent Assay and Rapid Immuno-Diagnostic Test for Rabies Antigen Detection in Archived Dog Brain Tissues ». Folia Veterinaria 62, no 1 (1 mars 2018) : 18–24. http://dx.doi.org/10.2478/fv-2018-0003.
Texte intégralRésumé :
Abstract Rabies urgently requires strengthening of new and existing diagnostic methodology in order to overcome the threat it poses. We evaluated the Enzyme Linked Immuno-Sorbent Assay (ELISA) and the Rapid Immunodiagnostic Test (RIDT) in detecting rabies viral antigens, comparing both tests with the Direct Fluorescent Antibody Test (DFAT) which is the gold standard in rabies diagnosis. Fifty dog brain tissues collected from the archives of the Central Diagnostic Laboratory, National Veterinary Research Institute, Vom, Nigeria, were utilized for this study. ELISA performed better than RIDT and recorded equivalent result with DFAT as compared with RIDT. There was a 96 % agreement between ELISA and DFAT for rabies antigen detection (concordance coefficient 78 % : 95 % C. I. 0.6366 to 0.8654) while there was a 54 % agreement between RIDT and DFAT (concordance coefficient 17 % : 95 % C. I. 0.05138—0.2752). Compared to DFAT, the sensitivities of ELISA and RIDT were 95.5 % and 47.6 %, respectively, and the specificities of ELISA and RIDT were 100 % and 87.5 % respectively. The simple Cohen’s kappa coefficient for ELISA related to the DFAT was found to be 0.834 (95 % C. I. 0.613—1.0). For RIDT, the Kappa value was 0.170 (95 % C. I. 0.003—0.337). The ELISA is as reliable a diagnostic method as the DFAT which is the gold standard for rabies diagnosis. It has an advantage of being able to analyse large number of samples at the same time, making it more suitable for epidemiological studies and for laboratories that cannot perform the DFAT. The unsatisfactory result of RIDT in this study reiterates the need to perform an adequate test validation before it can be used in the laboratory for rabies diagnosis.
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Schrama, Johan W., Mahmoud N. Haidar, Inge Geurden, Leon T. N. Heinsbroek et Sachi J. Kaushik. « Energy efficiency of digestible protein, fat and carbohydrate utilisation for growth in rainbow trout and Nile tilapia ». British Journal of Nutrition 119, no 7 (23 mars 2018) : 782–91. http://dx.doi.org/10.1017/s0007114518000259.
Texte intégralRésumé :
AbstractCurrently, energy evaluation of fish feeds is performed on a digestible energy basis. In contrast to net energy (NE) evaluation systems, digestible energy evaluation systems do not differentiate between the different types of digested nutrients regarding their potential for growth. The aim was to develop an NE evaluation for fish by estimating the energy efficiency of digestible nutrients (protein, fat and carbohydrates) and to assess whether these efficiencies differed between Nile tilapia and rainbow trout. Two data sets were constructed. The tilapia and rainbow data set contained, respectively, eight and nine experiments in which the digestibility of protein, fat and energy and the complete energy balances for twenty-three and forty-five diets was measured. The digestible protein (dCP), digestible fat (dFat) and digestible carbohydrate intakes (dCarb) were calculated. By multiple regression analysis, retained energy (RE) was related to dCP, dFat and dCarb. In tilapia, all digestible nutrients were linearly related to RE (P<0·001). In trout, RE was quadratically related to dCarb (P<0·01) and linearly to dCP and dFat (P<0·001). The NE formula was NE=11·5×dCP+35·8×dFAT+11·3×dCarb for tilapia and NE=13·5×dCP+33·0×dFAT+34·0×dCarb–3·64×(dCarb)2 for trout (NE in kJ/(kg0·8×d); dCP, dFat and dCarb in g/(kg0·8×d)). In tilapia, the energetic efficiency of dCP, dFat and dCarb was 49, 91 and 66 %, respectively, showing large similarity with pigs. Tilapia and trout had similar energy efficiencies of dCP (49 v. 57 %) and dFat (91 v. 84 %), but differed regarding dCarb.
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Mikrogeorgiou, Alkisti, Yoshiaki Sato, Taiki Kondo, Tetsuo Hattori, Yuichiro Sugiyama, Miharu Ito, Akiko Saito et al. « Dedifferentiated Fat Cells as a Novel Source for Cell Therapy to Target Neonatal Hypoxic-Ischemic Encephalopathy ». Developmental Neuroscience 39, no 1-4 (2017) : 273–86. http://dx.doi.org/10.1159/000455836.
Texte intégralRésumé :
Neonatal hypoxic-ischemic (HI) encephalopathy (HIE) remains a major cause of mortality and persistent neurological disabilities in affected individuals. At present, hypothermia is considered to be the only applicable treatment option, although growing evidence suggests that cell-based therapy might achieve better outcomes. Dedifferentiated fat (DFAT) cells are derived from mature adipocytes via a dedifferentiation strategy called ceiling culture. Their abundance and ready availability might make them an ideal therapeutic tool for the treatment of HIE. In the present study, we aimed to determine whether the outcome of HIE can be improved by DFAT cell treatment. HI injury was achieved by ligating the left common carotid artery in 7-day-old rat pups, followed by 1-h exposure to 8% O2. Subsequently, the severity of damage was assessed by diffusion-weighted magnetic resonance imaging to assign animals to equivalent groups. 24 h after hypoxia, DFAT cells were injected at 105 cells/pup into the right external jugular vein. To evaluate brain damage in the acute phase, a group of animals was sacrificed 48 h after the insult, and paraffin sections of the brain were stained to assess several acute injury markers. In the chronic phase, the behavioral outcome was measured by performing a series of behavioral tests. From the 24th day of age, the sensorimotor function was examined by evaluating the initial forepaw placement on a cylinder wall and the latency to falling from a rotarod treadmill. The cognitive function was tested with the novel object recognition (NOR) test. In vitro conditioned medium (CM) prepared from cultured DFAT cells was added at various concentrations to neuronal cell cultures, which were then exposed to oxygen-glucose deprivation (OGD). The number of cells that stained positive for the apoptosis marker active caspase-3 decreased by 73 and 52% in the hippocampus and temporal cortex areas of the brain, respectively, in the DFAT-treated pups. Similarly, the numbers of ED-1-positive cells (activated microglia) decreased by 66 and 44%, respectively, in the same areas in the DFAT-treated group. The number of cells positive for the oxidative stress marker 4-hydroxyl-2-nonenal decreased by 68 and 50% in the hippocampus and the parietal cortex areas, respectively, in the DFAT-treated group. The HI insult led to a motor deficit according to the rotarod treadmill and cylinder test, where it significantly affected the vehicle group, whereas no difference was confirmed between the DFAT and sham groups. However, the NOR test indicated no significant differences between any of the groups. DFAT treatment did not reduce the infarct volume, which was confirmed immunohistochemically. According to in vitro experiments, the cell death rates in the DFAT-CM-treated cells were significantly lower than those in the controls when DFAT-CM was added 48 h prior to OGD. The treatment effect of adding DFAT-CM 24 h prior to OGD was also significant. Our results indicate that intravenous injection with DFAT cells is effective for ameliorating HI brain injury, possibly via paracrine effects.
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Figiel-Dabrowska, Anna, Klaudia Radoszkiewicz, Paulina Rybkowska, Natalia Ewa Krzesniak, Dorota Sulejczak et Anna Sarnowska. « Neurogenic and Neuroprotective Potential of Stem/Stromal Cells Derived from Adipose Tissue ». Cells 10, no 6 (11 juin 2021) : 1475. http://dx.doi.org/10.3390/cells10061475.
Texte intégralRésumé :
Currently, the number of stem-cell based experimental therapies in neurological injuries and neurodegenerative disorders has been massively increasing. Despite the fact that we still have not obtained strong evidence of mesenchymal stem/stromal cells’ neurogenic effectiveness in vivo, research may need to focus on more appropriate sources that result in more therapeutically promising cell populations. In this study, we used dedifferentiated fat cells (DFAT) that are proven to demonstrate more pluripotent abilities in comparison with standard adipose stromal cells (ASCs). We used the ceiling culture method to establish DFAT cells and to optimize culture conditions with the use of a physioxic environment (5% O2). We also performed neural differentiation tests and assessed the neurogenic and neuroprotective capability of both DFAT cells and ASCs. Our results show that DFAT cells may have a better ability to differentiate into oligodendrocytes, astrocytes, and neuron-like cells, both in culture supplemented with N21 and in co-culture with oxygen–glucose-deprived (OGD) hippocampal organotypic slice culture (OHC) in comparison with ASCs. Results also show that DFAT cells have a different secretory profile than ASCs after contact with injured tissue. In conclusion, DFAT cells constitute a distinct subpopulation and may be an alternative source in cell therapy for the treatment of nervous system disorders.
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Murata, Yasutaka, Daisuke Obinata, Taro Matsumoto, Yuichiro Ikado, Koichiro Kano, Noboru Fukuda, Kenya Yamaguchi et Satoru Takahashi. « Urethral injection of dedifferentiated fat cells ameliorates sphincter damage and voiding dysfunction in a rat model of persistence stress urinary incontinence ». International Urology and Nephrology 54, no 4 (17 février 2022) : 789–97. http://dx.doi.org/10.1007/s11255-021-03083-3.
Texte intégralRésumé :
Abstract Purpose Dedifferentiated fat (DFAT) cells are mature adipocyte-derived multipotent cells that can be applicable to cell-based therapy for stress urinary incontinence (SUI). This study developed a persistence SUI model that allows long-term evaluation using a combination of vaginal distention (VD) and bilateral ovariectomy (OVX) in rats. Then, the therapeutic effects of DFAT cell transplantation in the persistence SUI model was examined. Methods In total, 48 Sprague–Dawley rats were divided into four groups and underwent VD (VD group), bilateral OVX (OVX group), VD and bilateral OVX (VD + OVX group), or sham operation (Control group). At 2, 4, and 6 weeks after injury, leak point pressure (LPP) and histological changes of the urethral sphincter were evaluated. Next, 14 rats undergoing VD and bilateral OVX were divided into two groups and administered urethral injection of DFAT cells (DFAT group) or fibroblasts (Fibroblast group). At 6 weeks after the injection, LPP and histology of the urethral sphincter were evaluated. Results The VD + OVX group retained a decrease in LPP with sphincter muscle atrophy at least until 6 weeks after injury. The LPP and urethral sphincter muscle atrophy in the DFAT group recovered better than those in the fibroblast group. Conclusions The persistence SUI model was created by a combination of VD and bilateral OVX in rats. Urethral injection of DFAT cells inhibited sphincter muscle atrophy and improved LPP in the persistence SUI model. These findings suggest that the DFAT cells may be an attractive cell source for cell-based therapy to treat SUI.
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Kra, Gitit, Jayasimha Rayalu Daddam, Hadar Gabay, Sara Yosefi et Maya Zachut. « Antioxidant Resveratrol Increases Lipolytic and Reduces Lipogenic Gene Expression under In Vitro Heat Stress Conditions in Dedifferentiated Adipocyte-Derived Progeny Cells from Dairy Cows ». Antioxidants 10, no 6 (3 juin 2021) : 905. http://dx.doi.org/10.3390/antiox10060905.
Texte intégralRésumé :
Heat stress (HS) induces oxidative stress by increasing reactive oxygen species (ROS), and the polyphenol resveratrol (RSV) has been shown to have antioxidant properties by reducing ROS. Hence, we aimed to examine the effects of RSV, HS and their interaction on bovine adipocytes. We generated bovine dedifferentiated adipocyte-derived progeny (DFAT) cells from subcutaneous adipose tissue and examined the effects of RSV (100 µM), heat conditions: isothermal (ISO-37 °C), short heat (SH-41.2 °C for 1 h) and long HS (LH-41.2 °C for 16 h), and their interaction on gene expression in DFAT-cells. In medium of DFAT-cells treated with RSV, malondialdehyde levels were reduced and oxygen-radical absorbance-capacity levels were increased compared to control. Treating DFAT-cells with RSV increased the relative mRNA expression of stress-induced-phosphoprotein-1 (STIP1) and the expression of hormone-sensitive-lipase (LIPE) and perilipin-1 (PLIN1), whereas it reduced the expressions of fatty-acid-synthase (FASN) and of pro-inflammatory chemotactic-C-C-motif-chemokine-ligand-2 (CCL2) also under HS. Moreover, reduced protein abundance of FASN was found in RSV-treated DFAT-cells compared to controls. Molecular docking of RSV with FASN confirmed its possible binding to FASN active site. This work demonstrates that RSV has an antioxidant effect on bovine DFAT cells and may induce adipose lipolysis and reduce lipogenesis also under in vitro HS conditions.
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Bui, David Pham, Kathryn Gibb, Martha Fiellin, Andrea Rodriguez, Claire Majka, Carolina Espineli, Elisabeth Gebreegziabher, Jennifer Flattery et Ximena P. Vergara. « Occupational COVID-19 Exposures and Illnesses among Workers in California—Analysis of a New Occupational COVID-19 Surveillance System ». International Journal of Environmental Research and Public Health 20, no 13 (6 juillet 2023) : 6307. http://dx.doi.org/10.3390/ijerph20136307.
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Little is known about occupational SARS-CoV-2 exposures and COVID-19 outcomes. We established a Doctor’s First Reports of Occupational Injury or Illness (DFR)-based surveillance system to study cases of work-related COVID-19 exposures and disease. The surveillance data included demographics, occupation, industry, exposure, and illness, details including hospitalization and lost work. We classified workers into ‘healthcare’, non-healthcare ‘public-facing’, or ‘other’ worker groups, and rural–urban commuting areas (RUCAs). We describe worker exposures and outcomes overall by worker group and RUCA. We analyzed 2848 COVID-19 DFRs representing workers in 22 detailed occupation groups and 19 industry groups. Most DFRs were for workers in metropolitan RUCAs (89%) and those in healthcare (42%) and public-facing (24%) worker groups. While DFRs were from 382 unique worksites, 52% were from four hospitals and one prison. Among 1063 DFRs with a suspected exposure, 73% suspected exposure to a patient or client. Few DFRs indicated hospitalization (3.9%); however, the proportion hospitalized was higher among nonmetropolitan (7.4%) and public-facing (6.7%) workers. While 56% of DFRs indicated some lost work time, the proportion was highest among public-facing (80%) workers. Healthcare and prison workers were the majority of reported occupational COVID-19 exposures and illnesses. The risk of COVID-19 hospitalization and lost work may be highest among nonmetropolitan and public-facing workers.
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SOUSA, MARGARIDA, VANESSA SILVA, ADRIANA SILVA, NUNO SILVA, JESSICA RIBEIRO, MARÍA TERESA TEJEDOR-JUNCO, ROSA CAPITA et al. « Staphylococci among Wild European Rabbits from the Azores : A Potential Zoonotic Issue ? » Journal of Food Protection 83, no 7 (22 juin 2020) : 1110–14. http://dx.doi.org/10.4315/0362-028x.jfp-19-423.
Texte intégralRésumé :
ABSTRACT The prevalence and diversity of Staphylococcus species from wild European rabbits (Oryctolagus cuniculus) in the Azores were investigated, and the antibiotic resistance phenotype and genotype of the isolates were determined. Nasal samples from 77 wild European rabbits from São Jorge and São Miguel islands in Azores were examined. Antibiotic susceptibility of the isolates was determined using the Kirby-Bauer disk diffusion method, and the presence of antimicrobial resistance genes and virulence factors was determined by PCR. The genetic lineages of S. aureus isolates were characterized by spa typing and multilocus sequence typing. A total of 49 staphylococci were obtained from 35 of the 77 wild rabbits. Both coagulase-positive (8.2%) and coagulase-negative (91.8%) staphylococci were detected: 4 S. aureus, 17 S. fleurettii, 13 S. sciuri, 7 S. xylosus, 4 S. epidermidis, and 1 each of S. simulans, S. saprophyticus, S. succinus, and S. equorum. The four S. aureus isolates showed methicillin susceptibility and were characterized as spa type t272/CC121, Panton-Valentine leukocidin negative, and hlB positive. Most of the coagulase-negative staphylococci showed resistance to fusidic acid and beta-lactams, and multidrug resistance was identified especially among S. epidermidis isolates. The mecA gene was detected in 20 isolates of the species S. fleurettii and S. epidermidis, associated with the blaZ gene in one S. epidermidis isolate. Five antimicrobial resistance genes were detected in one S. epidermidis isolate (mecA,dfrA,dfrG,aac6′-aph2′′, and ant4). Our results highlight that wild rabbits are reservoirs or “temporary hosts” of Staphylococcus species with zoonotic potential, some of them carrying relevant antimicrobial resistances. HIGHLIGHTS
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Silva, Vanessa, Jessica Ribeiro, Jaqueline Rocha, Célia M. Manaia, Adriana Silva, José Eduardo Pereira, Luís Maltez, José Luis Capelo, Gilberto Igrejas et Patrícia Poeta. « High Frequency of the EMRSA-15 Clone (ST22-MRSA-IV) in Hospital Wastewater ». Microorganisms 10, no 1 (11 janvier 2022) : 147. http://dx.doi.org/10.3390/microorganisms10010147.
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Hospital wastewaters often carry multidrug-resistant bacteria and priority pathogens, such as methicillin-resistant Staphylococcus aureus (MRSA). Pathogens and antibiotic resistance genes present in wastewaters may reach the natural environment facilitating their spread. Thus, we aimed to isolate MRSA from wastewater of 3 hospitals located in the north of Portugal and to characterize the isolates regarding the antimicrobial resistance and genetic lineages. A total of 96 wastewater samples were collected over six months. The water was filtered, and the filtration membrane was immersed in BHI broth supplemented with 6.5% of NaCl and incubated. The inoculum was streaked in ORSAB agar plates for MRSA isolation. The isolates susceptibility testing was performed against 14 antimicrobial agents. The presence of resistance and virulence genes was accessed by PCR. Molecular typing was performed in all isolates. From the 96 samples, 28 (29.2%) were MRSA-positive. Most isolates had a multidrug-resistant profile and carried the mecA, blaZ, aac(6′)-Ie-aph(2″)-Ia, aph(3′)-IIIa, ermA, ermB, ermC, tetL, tetM, dfrA dfrG and catpC221 genes. Most of the isolates were ascribed to the immune evasion cluster (IEC) type B. The isolates belonged to ST22-IV, ST8-IV and ST105-II and spa-types t747, t1302, t19963, t6966, t020, t008 and tOur study shows that MRSA can be found over time in hospital wastewater. The wastewater treatment processes can reduce the MRSA load. The great majority of the isolates belonged to ST22 and spa-type t747 which suggests the fitness of these genetic lineages in hospital effluents.
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Linsaenkart, Pichchapa, Warintorn Ruksiriwanich, Pensak Jantrawut, Chuda Chittasupho, Pornchai Rachtanapun, Kittisak Jantanasakulwong, Sarana Rose Sommano et al. « Natural Melanogenesis Inhibitor, Antioxidant, and Collagen Biosynthesis Stimulator of Phytochemicals in Rice Bran and Husk Extracts from Purple Glutinous Rice (Oryza sativa L. cv. Pieisu 1 CMU) for Cosmetic Application ». Plants 12, no 4 (20 février 2023) : 970. http://dx.doi.org/10.3390/plants12040970.
Texte intégralRésumé :
Oryza sativa L. cv. Pieisu 1 CMU (PES1CMU) has a high anthocyanin content in the colored bran and high phenolic content in the husk. Biologically active compounds in plants are available as dietary supplements and cosmetics. To expand the utilization of natural resources, PES1CMU will be a natural remedy for skin hyperpigmentation and aging. Cell-free tyrosinase inhibition and scavenging assays were used to screen all extracts, including PES1CMU-rice bran oil (RBO), PES1CMU-defatted rice bran (DFRB), and PES1CMU-husk (H). PES1CMU extracts were first examined in IBMX-stimulated B16 cells and H2O2-induced fibroblasts. The results exhibited that PES1CMU-DFRB was the most effective inhibitor of mushroom tyrosinase, intracellular melanin production (fold change of 1.11 ± 0.01), and tyrosinase activity (fold change of 1.22 ± 0.10) in IBMX-stimulated B16 cells. Particularly, PES1CMU-DFRB showed a comparable whitening effect to the standard arbutin with no significant difference (p > 0.05). Moreover, PES1CMU-DFRB and PES1CMU-H demonstrated strong scavenging activities. After accelerated cell aging caused by H2O2 exposure in fibroblasts, the levels of malondialdehyde production in all PES1CMU-treated fibroblasts were comparable with those of standard l-ascorbic acid (p > 0.05). Besides, PES1CMU-DFRB and PES1CMU-H treatment significantly inhibited collagen degradation against MMP-2 compared to l-ascorbic acid-treated cells (p > 0.05). PES1CMU rice-processing wastes (DFRB and H) could become potential natural sources for dermatocosmetic constituents in skin anti-aging and whitening products.
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Yin, Linfei, Lulin Zhao, Tao Yu et Xiaoshun Zhang. « Deep Forest Reinforcement Learning for Preventive Strategy Considering Automatic Generation Control in Large-Scale Interconnected Power Systems ». Applied Sciences 8, no 11 (7 novembre 2018) : 2185. http://dx.doi.org/10.3390/app8112185.
Texte intégralRésumé :
To reduce occurrences of emergency situations in large-scale interconnected power systems with large continuous disturbances, a preventive strategy for the automatic generation control (AGC) of power systems is proposed. To mitigate the curse of dimensionality that arises in conventional reinforcement learning algorithms, deep forest is applied to reinforcement learning. Therefore, deep forest reinforcement learning (DFRL) as a preventive strategy for AGC is proposed in this paper. The DFRL method consists of deep forest and multiple subsidiary reinforcement learning. The deep forest component of the DFRL is applied to predict the next systemic state of a power system, including emergency states and normal states. The multiple subsidiary reinforcement learning component, which includes reinforcement learning for emergency states and reinforcement learning for normal states, is applied to learn the features of the power system. The performance of the DFRL algorithm was compared to that of 10 other conventional AGC algorithms on a two-area load frequency control power system, a three-area power system, and the China Southern Power Grid. The DFRL method achieved the highest control performance. With this new method, both the occurrences of emergency situations and the curse of dimensionality can be simultaneously reduced.