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Tasneem Gul Kazi Suraya Samejo Hassan Imran Afridi Asma Akhtar Jameel Ahmed Baig 《应用有机金属化学》2020,34(1):e5263
In the present study the cadmium (Cd) was determined in serum samples of psoriatic patients. The severity of psoriasis was evaluated according to criteria based on standard clinical diagnosis using Psoriasis Area Severity Index (PASI) score. In present study, an innovative tunable green solvent system based microextraction (TSS-ME) was applied for the enrichment of Cd in acid digested serum samples prior to determination with flame atomic absorption spectrometry. The hydrophobic complex of Cd-ammonium pyrrolidine thiocarbamate was extracted in a tunable solvent system which was prepared from a polybasic amine (N, N, N′, N′-tetramethyl-1, 4-diaminobutane), decanol and water system. The tunable green solvent system (TSS) which has zero ionic strength was converted to homogeneous monophasic polar hydrophilic phase via exposure to CO2 at different pressure and time duration. Then hydrophobic enriched Cd- ammonium pyrrolidine thiocarbamate was back extracted, using HNO3 (0.1 to 0.5 mol L−1) then the second round of TSS-ME was applied. The acidic aqueous phase enrich with analyte was separated from tunable solvent. The separated TSS was easily reused for up to 10 time for preconcentration purposes without loss of its enrichment character. The smoker and nonsmoker psoriatic patients at PASI >10, have two to three folds higher Cd levels in serum samples than healthy persons. 相似文献
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This paper considers the problem of change point in single index models. In order to obtain asymptotically valid confidence intervals for the estimation of the change point, the convergence rate and asymptotic distribution of the change point estimate is studied. Some simulation results are presented which show that the numerical performance of our estimator is satisfactory. 相似文献
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Topological indices are numerical parameters of a molecular graph, which characterize its topology and are usually graph invariant. In quantitative structure–activity relationship/quantitative structure–property relationship study, physico‐chemical properties and topological indices such as Randić, atom–bond connectivity (ABC), and geometric–arithmetic (GA) index are used to predict the bioactivity of chemical compounds. Graph theory has found a considerable use in this area of research. In this paper, we study hex‐derived networks HDN1(n) and HDN2(n), which are generated by hexagonal network of dimension n and derive analytical closed results of general Randić index Rα(G) for different values of α, for these networks of dimension n. We also compute the general first Zagreb, ABC, GA, ABC4, and GA5 indices for these hex‐derived networks for the first time and give closed formulae of these degree‐based indices for hex‐derived networks. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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Houmem Belkhechine 《Discrete Mathematics》2017,340(12):2986-2994
Given a tournament , a module of is a subset of such that for and , if and only if . The trivial modules of are ,
and . The tournament is indecomposable if all its modules are trivial; otherwise it is decomposable. The decomposability index of , denoted by , is the smallest number of arcs of that must be reversed to make indecomposable. For , let be the maximum of over the tournaments with vertices. We prove that and that the lower bound is reached by the transitive tournaments. 相似文献
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Ali Akbar Yazdan Pour 《代数通讯》2017,45(4):1483-1492
Let I be a monomial ideal in the polynomial ring S generated by elements of degree at most d. In this paper, it is shown that, if the i-th syzygy of I has no elements of degrees j,…,j+(d?1) (where j≥i+d), then (i+1)-th syzygy of I does not have any element of degree j+d. Then we give several applications of this result, including an alternative proof for Green–Lazarsfeld index of the edge ideals of graphs as well as an alternative proof for Fröberg’s theorem on classification of square-free monomial ideals generated in degree 2 with linear resolution. Among all, we deduce a partial result on subadditivity of the syzygies for monomial ideals. 相似文献
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Amal AlAli 《代数通讯》2017,45(11):4667-4678