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41.
Prerna Kalra Ritu Karwasra Yogendra Kumar Gupta Subrata Basu Ray 《Natural product research》2019,33(11):1641-1645
In the present study, we have evaluated the nephroprotective effect of hydroalcoholic extract of Terminalia chebula in cisplatin-induced nephrotoxicity model. Standardised extract was orally administered to Wistar rats for 10 days at different doses. On day 7, 8 mg/kg of cisplatin was administered intra-peritoneally to rats in all groups. T. chebula, in a dose-dependent manner significantly inhibited the elevation of serum creatinine, blood urea nitrogen and oxidant stress markers. The immunohistochemical analysis revealed the increased levels of apoptotic markers and cytokines in cisplatin group were significantly lowered by T. chebula extract. The cisplatin-treated rats kidney showed diffused tubular necrosis and infilteration of inflammatory cells which was reversed in the treatment group. Chemical characterisation of extract by HPLC revealed the presence of corilagin, chebulinic, chebulagic, chebulic, gallic and ellagic acid. The findings of this study discovered that T. chebula ameliorated oxidative and histological damage caused by cisplatin. 相似文献
42.
Dr. Kalyanashis Mandal Dr. Deepak Bansal Yogendra Kumar Rustam Dr. Jyoti Shukla Dr. Pritam Mukhopadhyay 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(46):10607-10619
Halogen-bonding interactions in electron-deficient π scaffolds have largely been underexplored. Herein, the halogen-bonding properties of arylene imide/diimide-based electron-deficient scaffolds were studied. The influence of scaffold size, from small (phthalimide) to moderately sized (pyromellitic diimide or naphthalenediimides) to large (perylenediimide), axial-group modification, and number of halo substituents on the halogen bonding and its self-assembly was probed in a set of nine compounds. The structural modification leads to tunable optical and redox properties. The first reduction potential ranges between −1.09 and −0.17 V (vs. SCE). Two of the compounds, that is, 6 and 9 , have deep-lying LUMOs with values reaching −4.2 eV. Single crystals of all nine systems were obtained, which showed Br ⋅⋅⋅ O, Br ⋅⋅⋅ Br, or Br ⋅⋅⋅ π halogen-bonding interactions, and a few systems are capable of forming all three types. These interactions lead to halogen-bonded rings (up to 12-membered), which propagate to form stacked 1D, 2D, or corrugated sheets. A few outliers were also identified, for example, molecules that prefer C−H ⋅⋅⋅ O hydrogen bonding over halogen bonding, or noncentrosymmetric rather than centrosymmetric organization. Computational studies based on Atoms in Molecules and Natural Bond Orbital analysis provided further insight into the halogen-bonding interactions. This study can lead to a predictive design tool-box to further explore related systems on surfaces reinforced by these weak directional forces. 相似文献
43.
Yogendra P. Chaubey 《Statistics & probability letters》1985,3(1):51-53
The theory of Minimum Norm Quadratic Estimators for estimating variances and covariances is applied to show that some commonly used estimators of covariances in time series models are easily derived using the above principle. In applying the theory MINQE, it is observed that no unbiased estimator exists in the class of invariant quadratics. 相似文献
44.
This investigation deals with the geometrically non-linear axisymmetric static analysis of elastic orthotropic thin annular plates subjected to uniformly distributed and ring loads. Non-linear differential equations in terms of the transverse displacement w and stress function ψ have been employed. Both w and ψ are expanded in finite power series and the orthogonal point collocation method has been used to obtain discretised algebraic equations from the governing differential equations. Results have been presented for annular plates with and without a rigid plug in the hole; simply supported, clamped and free outer edge conditions; three orthotropic parameters β; two annular ratios and two loading conditions. Results have also been presented illustrating the effect of an elastic rotational constraint at the edge and the effect of a prescribed inplane displacement of the edge. 相似文献
45.
Tripathi Alok Kumar Verma Yogendra Lal Shalu Singh Varun Kumar Balo Liton Gupta Himani Singh Shishir Kumar Singh Rajendra Kumar 《Journal of Solid State Electrochemistry》2017,21(11):3365-3371
Journal of Solid State Electrochemistry - Quasi solid-state electrolytes (QS-SEs) based on an ionic liquid ([EMIM][FSI]) immobilized in ordered mesoporous silica MCM-41 using physical imbibition... 相似文献
46.
Let {Xn,n≥1} be a sequence of stationary non-negative associated random variables with common marginal density f(x). Here we use the empirical survival function as studied in Bagai and Prakasa Rao (1991) and apply the smoothing technique proposed by Gawronski (1980) (see also Chaubey and Sen, 1996) in proposing a smooth estimator of the density function f and that of the corresponding survival function. Some asymptotic properties of the resulting estimators, similar to those obtained in Chaubey and Sen (1996) for the i.i.d. case, are derived. A simulation study has been carried out to compare the new estimator to the kernel estimator of a density function given in Bagai and Prakasa Rao (1996) and the estimator in Buch-Larsen et al. (2005). 相似文献
47.
48.
Singh Y Sharpe PC Hoang HN Lucke AJ McDowall AW Bottomley SP Fairlie DP 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(1):151-160
Transformation of proteins and peptides to fibrillar aggregates rich in β sheets underlies many diseases, but mechanistic details of these structural transitions are poorly understood. To simulate aggregation, four equivalents of a water‐soluble, α‐helical (65 %) amphipathic peptide (AEQLLQEAEQLLQEL) were assembled in parallel on an oxazole‐containing macrocyclic scaffold. The resulting 4α‐helix bundle is monomeric and even more α helical (85 %), but it is also unstable at pH 4 and undergoes concentration‐dependent conversion to β‐sheet aggregates and amyloid fibrils. Fibrils twist and grow with time, remaining flexible like rope (>1 μm long, 5–50 nm wide) with multiple strings (2 nm), before ageing to matted fibers. At pH 7 the fibrils revert back to soluble monomeric 4α‐helix bundles. During α→β folding we were able to detect soluble 310 helices in solution by using 2D‐NMR, CD and FTIR spectroscopy. This intermediate satisfies the need for peptide elongation, from the compressed α helix to the fully extended β strand/sheet, and is driven here by 310‐helix aggregation triggered in this case by template‐promoted helical bundling and by hydrogen‐bonding glutamic acid side chains. A mechanism involving α?α4?(310)4?(310)n?(β)n?m(β)n equilibria is plausible for this peptide and also for peptides lacking hydrogen‐bonding side chains, with unfavourable equilibria slowing the α→β conversion. 相似文献
49.
Yogendra Singh Ravi Kumar Gundampati Medicherla V. Jagannadham S. K. Srivastava 《Applied biochemistry and biotechnology》2013,171(7):1759-1774
An extracellular l-asparaginase produced by a protease-deficient isolate, Bacillus aryabhattai ITBHU02, was purified to homogeneity using ammonium sulfate fractionation and subsequent column chromatography on diethylaminoethyl-Sepharose fast flow and Seralose CL-6B. The enzyme was purified 68.9-fold with specific activity of 680.47 U mg?1. The molecular weight of the purified enzyme was approximately 38.8 kDa on SDS-PAGE and 155 kDa on native PAGE gel as well as gel filtration column revealing that the enzyme was a homotetramer. The optimum activity of purified l-asparaginase was achieved at pH 8.5 and temperature 40 °C. Kinetic studies depicted that the K m, V max, and k cat values of the enzyme were 0.257 mM, 1.537 U μg?1, and 993.93 s?1, respectively. Circular dichroism spectroscopy has showed that the enzyme belonged to α?+?β class of proteins with approximately 74 % α-helices and 12 % β-sheets. BLASTP analysis of N-terminal sequence K-T-I-I-E-A-V-P-E-L-K-K-I-A of purified l-asparaginase had shown maximum similarity with Bacillus megaterium DSM 319. In vitro cytotoxicity assays with HL60 and MOLT-4 cell lines indicated that the l-asparaginase has significant antineoplastic properties. 相似文献
50.
Jitender M. Khurana Bhaskar M. Kandpal Yogendra K. Chauhan 《Phosphorus, sulfur, and silicon and the related elements》2013,188(6):1369-1375
A simple and convenient procedure for the rapid oxidation of a variety of selenides, selenoxides, tellurides, and telluroxides with aqueous sodium hypochlorite to selenones and tellurones, respectively, has been reported in dimethylformamide at ambient temperature. 相似文献