26 research outputs found

    Topological mechanochemistry of graphene

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    In view of a formal topology, two common terms, namely, connectivity and adjacency, determine the quality of C-C bonds of sp2 nanocarbons. The feature is the most sensitive point of the inherent topology of the species so that such external action as mechanical deformation should obviously change it and result in particular topological effects. The current paper describes the effects caused by uniaxial tension of a graphene molecule in due course of a mechanochemical reaction. Basing on the molecular theory of graphene, the effects are attributed to both mechanical loading and chemical modification of edge atoms of the molecule. The mechanical behavior is shown to be not only highly anisotropic with respect to the direction of the load application, but greatly dependent on the chemical modification of the molecule edge atoms thus revealing topological character of the graphene deformation.Comment: 9 pages, 10 figures, 1 table. arXiv admin note: text overlap with arXiv:1301.094

    Structure-Sensitive Mechanism of Nanographene Failure

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    The response of a nanographene sheet to external stresses is considered in terms of a mechanochemical reaction. The quantum chemical realization of the approach is based on a coordinate-of-reaction concept for the purpose of introducing a mechanochemical internal coordinate (MIC) that specifies a deformational mode. The related force of response is calculated as the energy gradient along the MIC, while the atomic configuration is optimized over all of the other coordinates under the MIC constant-pitch elongation. The approach is applied to the benzene molecule and (5, 5) nanographene. A drastic anisotropy in the microscopic behavior of both objects under elongation along a MIC has been observed when the MIC is oriented either along or normally to the C-C bonds chain. Both the anisotropy and high stiffness of the nanographene originate at the response of the benzenoid unit to stress.Comment: 19 pages, 7 figures 1 tabl

    Protective effects of combined Losartan and Nilotinib on carbon tetrachloride (CCl4)-induced liver fibrosis in rats

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    Tyrosine kinase inhibitors (TKIs) have been developed as therapeutic compounds for inhibiting the progression of liver fibrosis. In the present study, the simultaneous treatment of Nilotinib (TKIs) and Losartan was studied. Forty rats were divided into eight groups of fibrosis induced by carbon tetrachloride (CCl4) and therapeutics (Nilotinib, Losartan, and combination therapy). In the end, serum parameters of the liver and gene expression analysis of transforming growth factor-β1, its receptors (TβRII), platelet-derived growth factor, its receptors (PDGFRβ), matrix metalloproteinases (MMP-2 and MMP-9), tumor necrosis factor-α, cytochrome P450 2E1, and collagen1 type 1 were performed. The oxidant/antioxidant factors were also analyzed. Histopathology analysis along with α-SMA immunohistochemistry and hydroxyproline evaluation was also conducted for a more in-depth study. The overall results indicated a better therapeutic effect of co-treatment of Nilotinib–Losartan in comparison with the treatment of each of them alone. Interestingly, some gene and protein factors and fibrotic indices were reduced even to the normal levels of the control group. The results of this study suggest that co-administration of these two combinations, strengthens their anti-fibrotic properties and, due to the routine use of these compounds against AML and blood pressure, these compounds can be used with caution against human liver fibrosis. © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group

    First report of Taenia ovis infection in Danish sheep (Ovis aries)

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    We report Taenia ovis infection in Danish sheep for the first time. In spring 2016, the metocestode stage of T. ovis was at slaughter observed in heart muscles, diaphragm and skeletal muscles from approx. a third of all sheep from one specific farm localised in South Jutland. The diagnosis was confirmed by molecular typing of the mitochondrial cytochrome c oxidase I (cox1) gene. Three newly imported dogs were suspected but the definitive host was unidentifiable. The finding is not regulated in the meat control procedures. However, infected meat is usually condemned due to aesthetic reasons causing economic losses. Thus, finding of T. ovis is of concern to sheep meat producers in the area, as the infection could have spread further on to other farms
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