74 research outputs found

    Восстановительная дегидратация биоспиртов – перспективный путь получения моторных топлив

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    The reaction of reduction dehydratation of aliphatic alcohols into the hydrocarbons is the perspective approach for receiving liquid fuel. It opens ways to the industrial method of one-study receiving linear and cyclic alkanes, being high-energy components of aviation fuel, from bioalcohols (ethanol, butanols, pentanols). It has been found that combinated systems based on hydrides of intermetallic compounds are sufficiently effective catalysts and lead to the formation mixture of hydrocarbons with considerable content of isoalkanes. It has been appeared synergetic effect in formation of alkanes in the presence of two-component composition consisting of hydride intermetallic compound and alumoplatinum catalyst.Реакция восстановительной дегидратации алифатических спиртов в углеводороды является перспективным подходом к получению жидкого топлива. Она открывает пути к промышленному методу одностадийного получения линейных и циклических алканов, являющихся высококалорийными компонентами авиационного топлива, из биоспиртов (этанола, бутанолов, пентанолов). Выявлено, что комбинированные системы на основе гидридов интерметаллических соединений являются достаточно эффективными катализаторами и приводят к образованию смеси углеводородов со значительным содержанием изоалканов. Обнаружен синергический эффект в образовании алканов при использовании двухкомпонентной композиции, состоящей из гидрида интерметаллического соединения и алюмоплатинового катализатора

    Alternative-NHEJ Is a Mechanistically Distinct Pathway of Mammalian Chromosome Break Repair

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    Characterizing the functional overlap and mutagenic potential of different pathways of chromosomal double-strand break (DSB) repair is important to understand how mutations arise during cancer development and treatment. To this end, we have compared the role of individual factors in three different pathways of mammalian DSB repair: alternative-nonhomologous end joining (alt-NHEJ), single-strand annealing (SSA), and homology directed repair (HDR/GC). Considering early steps of repair, we found that the DSB end-processing factors KU and CtIP affect all three pathways similarly, in that repair is suppressed by KU and promoted by CtIP. In contrast, both KU and CtIP appear dispensable for the absolute level of total-NHEJ between two tandem I-SceI–induced DSBs. During later steps of repair, we find that while the annealing and processing factors RAD52 and ERCC1 are important to promote SSA, both HDR/GC and alt-NHEJ are significantly less dependent upon these factors. As well, while disruption of RAD51 causes a decrease in HDR/GC and an increase in SSA, inhibition of this factor did not affect alt-NHEJ. These results suggest that the regulation of DSB end-processing via KU/CtIP is a common step during alt-NHEJ, SSA, and HDR/GC. However, at later steps of repair, alt-NHEJ is a mechanistically distinct pathway of DSB repair, and thus may play a unique role in mutagenesis during cancer development and therapy

    Anti–Neutrophil Extracellular Trap Antibodies in Antiphospholipid Antibody–Positive Patients: Results From the Antiphospholipid Syndrome Alliance for Clinical Trials and InternatiOnal Networking Clinical Database and Repository

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    OBJECTIVE: This study aimed to elucidate the presence, antigen specificities, and potential clinical associations of anti–neutrophil extracellular trap (anti-NET) antibodies in a multinational cohort of antiphospholipid (aPL) antibody–positive patients who did not have lupus. METHODS: Anti-NET IgG/IgM levels were measured in serum samples from 389 aPL-positive patients; 308 patients met the classification criteria for antiphospholipid syndrome. Multivariate logistic regression with best variable model selection was used to determine clinical associations. For a subset of the patients (n = 214), we profiled autoantibodies using an autoantigen microarray platform. RESULTS: We found elevated levels of anti-NET IgG and/or IgM in 45% of the aPL-positive patients. High anti-NET antibody levels are associated with more circulating myeloperoxidase (MPO)–DNA complexes, which are a biomarker of NETs. When considering clinical manifestations, positive anti-NET IgG was associated with lesions affecting the white matter of the brain, even after adjusting for demographic variables and aPL profiles. Anti-NET IgM tracked with complement consumption after controlling for aPL profiles; furthermore, patient serum samples containing high levels of anti-NET IgM efficiently deposited complement C3d on NETs. As determined by autoantigen microarray, positive testing for anti-NET IgG was significantly associated with several autoantibodies, including those recognizing citrullinated histones, heparan sulfate proteoglycan, laminin, MPO–DNA complexes, and nucleosomes. Anti-NET IgM positivity was associated with autoantibodies targeting single-stranded DNA, double-stranded DNA, and proliferating cell nuclear antigen. CONCLUSION: These data reveal high levels of anti-NET antibodies in 45% of aPL-positive patients, where they potentially activate the complement cascade. While anti-NET IgM may especially recognize DNA in NETs, anti-NET IgG species appear to be more likely to target NET-associated protein antigens

    Kraft Lignin Conversion into Energy Carriers under the Action of Electromagnetic Radiation

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    In this work, it was found that the deposition of iron salts (iron acetate) on kraft lignin at extremely low concentrations of 0.1 wt.% leads to a sharp increase in the absorbing capacity of microwave radiation by kraft lignin at its power of 1 kW and the conversion of kraft lignin to a hydrogen-containing gas with the degree of hydrogen extraction, reaching 90% based on the hydrogen contained in the kraft lignin. It has been established that the deposition of metals (Fe and Ni) on kraft lignin allows one to directionally change the selectivity of the process of its destruction under the influence of microwave radiation, which makes it possible to classify the process as plasmacatalytic. The results obtained make it possible to minimize the amount of catalyst used and propose an efficient way of producing hydrogen from kraft lignin waste

    Analytic binding isotherms describing competitive interactions of a protein ligand with specific and nonspecific sites on the same DNA oligomer.

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    Many studies of specific protein-nucleic acid binding use short oligonucleotides or restriction fragments, in part to minimize the potential for nonspecific binding of the protein. However, when the specificity ratio is low, multiple nonspecifically bound proteins may occupy the region of DNA corresponding to one specific site; this situation was encountered in our recent calorimetric study of binding of integration host factor (IHF) protein to its specific 34-bp H' DNA site. Here, beginning from the analytical McGhee and von Hippel infinite-lattice nonspecific binding isotherm, we derive a novel analytic isotherm for nonspecific binding of a ligand to a finite lattice. This isotherm is an excellent approximation to the exact factorial-based Epstein finite lattice isotherm even for short lattices and therefore is of great practical significance for analysis of experimental data and for analytic theory. Using this isotherm, we develop an analytic treatment of the competition between specific and nonspecific binding of a large ligand to the same finite lattice (i.e., DNA oligomer) containing one specific and multiple overlapping nonspecific binding sites. Analysis of calorimetric data for IHF-H' DNA binding using this treatment yields enthalpies and binding constants for both specific and nonspecific binding and the nonspecific site size. This novel analysis demonstrates the potential contribution of nonspecific binding to the observed thermodynamics of specific binding, even with very short DNA oligomers, and the need for reverse (constant protein) titrations or titrations with nonspecific DNA to resolve specific and nonspecific contributions. The competition treatment is useful in analyzing low-specificity systems, including those where specificity is weakened by mutations or the absence of specificity factors

    Reduction dehydratation of bioalcohols – perspective way for receiving engine fuel.

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    The reaction of reduction dehydratation of aliphatic alcohols into the hydrocarbons is the perspective approach for receiving liquid fuel. It opens ways to the industrial method of one-study receiving linear and cyclic alkanes, being high-energy components of aviation fuel, from bioalcohols (ethanol, butanols, pentanols). It has been found that combinated systems based on hydrides of intermetallic compounds are sufficiently effective catalysts and lead to the formation mixture of hydrocarbons with considerable content of isoalkanes. It has been appeared synergetic effect in formation of alkanes in the presence of two-component composition consisting of hydride intermetallic compound and alumoplatinum catalyst
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