2,526 research outputs found

    The redox transformations and nucleophilic replacements as possible metabolic reactions of the drug “Triazaverin”. The chemical modeling of the metabolic processes

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    As a model of metabolic transformations of antiviral drug “Triazaverin” and its analogues‑2-alkylthio‑6-nitro‑1,2,4-triazolo[5,1-c][1,2,4]triazine‑7-ones 1a-d examined the oxidation of alkylthio groups to the corresponding sulfoxides 2a-d and sulfones 3a-d, as well as the process of nucleophilic substitution sulfonyloxy group of cysteine and cysteamine with the formation of compounds 5 and 6

    Role of direct exchange and Dzyaloshinskii-Moriya interactions in magnetic properties of graphene derivatives: C2_2F and C2_2H

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    According to the Lieb's theorem the ferromagnetic interaction in graphene-based materials with bipartite lattice is a result of disbalance between the number of sites available for pzp_z electrons in different sublattices. Here, we report on another mechanism of the ferromagnetism in functionalized graphene that is the direct exchange interaction between spin orbitals. By the example of the single-side semihydrogenated (C2_2H) and semifluorinated (C2_2F) graphene we show that such a coupling can partially or even fully compensate antiferromagnetic character of indirect exchange interactions reported earlier [Phys. Rev. B {\bf 88}, 081405(R) (2013)]. As a result, C2_2H is found to be a two-dimensional material with the isotropic ferromagnetic interaction and negligibly small magnetic anisotropy, which prevents the formation of the long-range magnetic order at finite temperature in accordance with the Mermin-Wagner theorem. This gives a rare example of a system where direct exchange interactions play a crucial role in determining a magnetic structure. In turn, C2_2F is found to be at the threshold of the antiferromagnetic-ferromagnetic instability, which in combination with the Dzyaloshinskii-Moriya interaction can lead to a skyrmion state.Comment: 10 page

    Outpatient management of patients with peripheral artery disease by cardiologists or surgeons: influence on the prognosis and prevalence of surgical interventions

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    Highlights. The study shows for the first time that during the three-year follow-up of patients with diseases of the arteries of the lower extremities in the observation groups of a general surgeon and a cardiologist, adverse events (myocardial infarction, stroke, amputation, disability) and deaths occurred more often in a surgeon than a cardiologist. The study proves the correctness and real benefit of such an approach with the involvement of a cardiologist to the outpatient stage of management of a complex cohort of patients with atherosclerosis of the vessels of the lower extremities.Aim. To study the effect the outpatient observation of patients with peripheral arteries disease (PAD) by cardiologists and surgeons has on timing and prevalence of reconstructive surgery and the prognosis of patients. Methods We analyzed the data on 585 PAD patients who underwent outpatient observation from 2010 to 2017, dividing them into 2 groups. The first group (131 patients) managed by an surgeon; the second (454 patients) managed by a cardiologist. Since the groups were not comparable in terms of the initial parameters, the comparability of patients in the groups (observation by a surgeon or by a cardiologist) was achieved using pseudorandomization. The follow-up period was three years; we assessed the incidence of deaths, adverse events, and the prevalence of reconstructive operations.Results. During a three-year follow-up the 1st group, compared with the 2nd, had more deaths in general (p<0.001), death from cardiac causes (p = 0.045), from stroke (p><0.001), as well as the total number of adverse events (p><0.001) and disability (p = 0.065). Indications for reconstructive surgery on the lower extremities arteries (LEA), and operations frequency were comparatible in groups. Amputation history, taking diuretics, presence of rhythm disturbances, and management by a surgeon increased the risk of adverse outcomes. Management by a cardiologist, reconstructive LEA surgeries, female sex improved the prognosis of patients. Conclusion Observation of PAD patients by a cardiologist contributes to a higher frequency of optimal drug therapy by patients and can reduce the number of adverse events in patients and improve their survival without affecting the timing and frequency of reconstructive LEA surgeries. Keywords Peripheral atherosclerosis • Outpatient follow-up • Optimal drug therapy • Reconstructive surgery>˂ 0.001), death from cardiac causes (p = 0.045), from stroke (p˂ 0.001), as well as the total number of adverse events (p˂ 0.001) and disability (p = 0.065). Indications for reconstructive surgery on the lower extremities arteries (LEA), and operations frequency were comparatible in groups. Amputation history, taking diuretics, presence of rhythm disturbances, and management by a surgeon increased the risk of adverse outcomes. Management by a cardiologist, reconstructive LEA surgeries, female sex improved the prognosis of patients.Conclusion. Observation of PAD patients by a cardiologist contributes to a higher frequency of optimal drug therapy by patients and can reduce the number of adverse events in patients and improve their survival without affecting the timing and frequency of reconstructive LEA surgeries.Highlights. The study shows for the first time that during the three-year follow-up of patients with diseases of the arteries of the lower extremities in the observation groups of a general surgeon and a cardiologist, adverse events (myocardial infarction, stroke, amputation, disability) and deaths occurred more often in a surgeon than a cardiologist. The study proves the correctness and real benefit of such an approach with the involvement of a cardiologist to the outpatient stage of management of a complex cohort of patients with atherosclerosis of the vessels of the lower extremities.Aim. To study the effect the outpatient observation of patients with peripheral arteries disease (PAD) by cardiologists and surgeons has on timing and prevalence of reconstructive surgery and the prognosis of patients. Methods We analyzed the data on 585 PAD patients who underwent outpatient observation from 2010 to 2017, dividing them into 2 groups. The first group (131 patients) managed by an surgeon; the second (454 patients) managed by a cardiologist. Since the groups were not comparable in terms of the initial parameters, the comparability of patients in the groups (observation by a surgeon or by a cardiologist) was achieved using pseudorandomization. The follow-up period was three years; we assessed the incidence of deaths, adverse events, and the prevalence of reconstructive operations.Results. During a three-year follow-up the 1st group, compared with the 2nd, had more deaths in general (p<0.001), death from cardiac causes (p = 0.045), from stroke (p><0.001), as well as the total number of adverse events (p><0.001) and disability (p = 0.065). Indications for reconstructive surgery on the lower extremities arteries (LEA), and operations frequency were comparatible in groups. Amputation history, taking diuretics, presence of rhythm disturbances, and management by a surgeon increased the risk of adverse outcomes. Management by a cardiologist, reconstructive LEA surgeries, female sex improved the prognosis of patients. Conclusion Observation of PAD patients by a cardiologist contributes to a higher frequency of optimal drug therapy by patients and can reduce the number of adverse events in patients and improve their survival without affecting the timing and frequency of reconstructive LEA surgeries. Keywords Peripheral atherosclerosis • Outpatient follow-up • Optimal drug therapy • Reconstructive surgery>˂ 0.001), death from cardiac causes (p = 0.045), from stroke (p˂ 0.001), as well as the total number of adverse events (p˂ 0.001) and disability (p = 0.065). Indications for reconstructive surgery on the lower extremities arteries (LEA), and operations frequency were comparatible in groups. Amputation history, taking diuretics, presence of rhythm disturbances, and management by a surgeon increased the risk of adverse outcomes. Management by a cardiologist, reconstructive LEA surgeries, female sex improved the prognosis of patients.Conclusion. Observation of PAD patients by a cardiologist contributes to a higher frequency of optimal drug therapy by patients and can reduce the number of adverse events in patients and improve their survival without affecting the timing and frequency of reconstructive LEA surgeries

    Supply Chain Infrastructure Development in Russian Economy

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    Abstract- The article is devoted to the study of the activities of Zemstvo institutions for the development of supply chain infrastructure in the XIX-early XX centuries; identification of the role of the Zemstvo reform in the formation of supply chain infrastructure at the local level. Supply Chain infrastructure provides the means for chain economic entities and firms sharing a common interest to participate in a mutual exchange. Despite the fact that the provision of supply chain services was not among the priorities of the Zemstvos, significant results were achieved. The retrospective analysis allowed us to highlight the advantages and disadvantages of the Zemstvo self-government system. The comparative method helped to identify trends in the financial and economic support of Zemstvo bodies at various stages of the Zemstvo reform, and to analyze key indicators of supply chain infrastructure development. It is concluded that the success of the Zemstvo self-government bodies in the development of supply chain infrastructure was due to the availability of significant organizational resources, ensuring sustainable interaction of Zemstvos with the population, active support for local initiatives and the formation of a system of public control. The authors note that the experience of implementing the principle of consolidation of the main directions of management activities for the development of supply chain infrastructure, formed by local authorities, can be in demand in modern conditions and adapted to the current system of local government in Russia for economy efficiency

    Corpus Analysis as a Means of Meaning Disambiguation: Collocational Analysis of Near-Synonyms of the Verb ‘Destroy’

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    The current paper is aimed at corpus-based differentiation of near-synonymous lexemes with the meaning ‘to destroy’. The research implies a series of consecutive steps: to discuss synonymy-related problems in modern linguistics; to compile a list of near-synonymous lexemes with the meaning ‘to destroy’ by means of Corpus of Contemporary American English (COCA); to analyze and compare definitions of the chosen verbs in Merriam-Webster Dictionary (MWD); to generate lists of right-context collocates for each of the verbs in COCA; to put the collocates into semantic clusters and compare the obtained clusters. The list of lexemes under study contains such verbs as ‘destroy’, ‘ruin’, ‘break’, ‘obliterate’, ‘raze’, ‘annihilate’, ‘crush’, ‘devastate’, ‘wreck’, and ‘demolish’. As a result, semantic clusterisation of the right-context collocates helped establish that all verbs of the group collocate with the lexemes representing values and threats where destroying values evokes negative feelings and associations while destroying threats is perceived as a positive action. The verb ‘ruin’ is typically used with the clusters ‘meals and food’, ‘holidays’, ‘leisure activities’, ‘entertainment’ and ‘human relations’, meaning deprivation of enjoyment and happiness. The verb ‘break’ has a wide array of collocates resulting in a variety of conventionalized expressions. The results of the corpus-based research of lexical semantics may be helpful to those professionally engaged in second language teaching as well as in translation and lexicographic practice

    Calculation scheme based on the extended equations of DMFT

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    This work was supported of grant program of the President of Russian Federation MD-6458.2016.2

    Role of Coulomb correlation on magnetic and transport properties of doped manganites: La0.5Sr0.5MnO3 and LaSr2Mn2O7

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    Results of LSDA and LSDA+U calculations of the electronic structure and magnetic configurations of the 50% hole-doped pseudocubic perovskite La0.5Sr0.5MnO3 and double layered LaSr2Mn2O7 are presented. We demonstrate that the on-site Coulomb correlation (U) of Mn d electrons has a very different influence on the (i) band formations, (ii) magnetic ground states, (iii) interlayer exchange interactions, and (iv) anisotropy of the electrical transport in these two manganites. A possible reason why the LSDA failures in predicting observed magnetic and transport properties of the double layered compound - in contrast to the doped perovskite manganite - is considered on the basis of a p-d hybridization analysis.Comment: 11 pages, 3 figure
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