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221.
Pallavi Singh Rakesh Tripathi Rajiv K. Verma Ganesh C. Nandi Ashutosh Gupta Maya S. Singh 《Phosphorus, sulfur, and silicon and the related elements》2013,188(10):2142-2151
A simple and efficient synthesis of previously unknown benzosubstituted dioxaphosphonines containing a quinoxaline subunit is described. Reasonably good yields of the products, mild reaction conditions, and convenient work-up are the advantages of this method. The procedure does not require any catalyst or activator and can be efficiently achieved via dianion cyclization. All the synthesized compounds have been characterized by satisfactory elemental analyses and spectral (IR, 1H, 13C, 31P NMR, and mass) studies. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file. 相似文献
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224.
Rahul Kumar Manviri Rani Himanshu Gupta Daeryong Park 《International journal of environmental analytical chemistry》2017,97(7):637-656
This study reports the distribution of Cr, Ni, Cu and Pb in waters, sediments, macrophytes and fish of the Yamuna River’s patch in Delhi (India). This is one of the most polluted stretches of rivers in the world. Water from this river is used fosr irrigation, industrial and domestic purposes, including drinking water. The effects of season and anthropogenic practices were identified. Almost zero dissolved oxygen and high levels of lead and phosphate indicate the polluted state of the aquatic system. The enrichment factors in sediments (with respect to reference site) vary in the range of 0.60–82.9% (Cr), 1.40–90.5% (Ni), 1.00–85.3% (Cu) and 3.80–86.6% (Pb). The toxic effects due to Ni and Pb could frequently be visible in aquatic life as their values fall above the probable effect level (36 mg Kg?1 for Ni and 91.3 mg Kg?1 for Pb). The metal contents in the macrophyte (Eichhornia crassipes) and the fish (Oreochromis niloticus) generally increase in the summer season. Cu and Pb accumulate preferentially in E. crassipes. The fish from these waters is unsuitable for human consumption as the levels of Cr, Cu and Pb are above the recommended limits. Significant spatial variations in parameters of water and sediments were confirmed via one-way analysis of variance. The Pearson’s correlation analysis suggests a common source of some of the metals. Principal component analysis highlighted domestic, and industrial waste and coal-fired thermal power plants as the metal sources. This study might act as a benchmark for other investigations focused on similarly affected surface aquatic systems due to agricultural and industrial activities. 相似文献
225.
R. K. Gupta A. K. Sinha B. N. Raja Sekhar A. K. Srivastava G. Singh S. K. Deb 《Applied Physics A: Materials Science & Processing》2011,103(1):13-19
Controllable and uniform doping of nanowires (NWs) is the ultimate challenge prior to their effective application. Si NWs
amorphize and bend toward the impinging ions under ion irradiation as a result of viscous flow. We demonstrate that thermal
annealing induces a full recovery of the crystalline phase corresponding to the unbending of the NWs. The competition between
Solid Phase Epitaxy and Random Nucleation and Growth at the nanoscale is the key parameter controlling the recovery. 相似文献
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Aarti Gupta Pragati Devi Priyanka Chaudhary Dharma Kishore 《Phosphorus, sulfur, and silicon and the related elements》2013,188(7):808-821
Abstract The synthetic potential of 2,3,4,5-tetrahydrobenzo[b] [1,5]thiazepine-1,1,4-trione-2-carbohydrazide (5) which resulted from ethyl-4-oxo-2,3,4,5-tetrahydrobenzo[b] [1,5]thiazepine-2-carboxylate (3), on its oxidation with H2O2/AcOH followed by treatment with NH2NH2.H2O, was exploited to provide an access to 2-triazolo, 2-oxadiazolo, and 2-pyrazolo substituted derivatives of 1,5-benzothiazepin-4-oxo-1,1-dioxides (6–10), respectively. 相似文献
228.
A.K. Gupta S.S. Bhunia V.M. Balaramnavar 《SAR and QSAR in environmental research》2013,24(3-4):239-263
A pharmacophore model has been developed using diverse classes of epidermal growth factor receptor (EGFR) tyrosine kinase (TK) inhibitors useful in the treatment of human tumours. Among the top 10 generated hypotheses, the second hypothesis, with one hydrogen bond acceptor, one ring aromatic and three hydrophobic features, was found to be the best on the basis of Cat Scramble validation as well as test set prediction (r training?=?0.89, r test?=?0.82). The model also maps well to the external test set molecules as well as clinically active molecules and corroborates the docking studies. Finally, 10 hits were identified as potential leads after virtual screening of ZINC database for EGFR TK inhibition. The study may facilitate the designing and discovery of novel EGFR TK inhibitors. 相似文献
229.
V. K. Vyas H. G. Bhatt P. K. Patel J. Jalu C. Chintha N. Gupta 《SAR and QSAR in environmental research》2013,24(7):519-551
SGLT2 has become a target of therapeutic interest in diabetes research. CoMFA and CoMSIA studies were performed on C-aryl glucoside SGLT2 inhibitors (180 analogues) as potential anti-diabetic agents. Three different alignment strategies were used for the compounds. The best CoMFA and CoMSIA models were obtained by means of Distill rigid body alignment of training and test sets, and found statistically significant with cross-validated coefficients (q 2) of 0.602 and 0.618, respectively, and conventional coefficients (r 2) of 0.905 and 0.902, respectively. Both models were validated by a test set of 36 compounds giving satisfactory predicted correlation coefficients (r 2 pred) of 0.622 and 0.584 for CoMFA and CoMSIA models, respectively. A comparison was made with earlier 3D QSAR study on SGLT2 inhibitors, which shows that our 3D QSAR models are better than earlier models to predict good inhibitory activity. CoMFA and CoMSIA models generated in this work can provide useful information to design new compounds and helped in prediction of activity prior to synthesis. 相似文献
230.
Amrita Jain S. K. Tripathi Ashish Gupta Manju Kumari 《Journal of Solid State Electrochemistry》2013,17(3):713-726
The present investigation deals with electrochemical double layer capacitors (EDLCs) made up of ionic liquid (IL)-based gel polymer electrolytes with chemically treated activated charcoal electrodes. The gel polymer electrolyte comprising of poly(vinylidine fluoride-co-hexafluropropylene) (PVdF-HFP)–1-ethyl-2,3-dimethyl-imidazolium-tetrafluroborate [EDiMIM][BF4]–propylene carbonate (PC)–magnesium perchlorate (Mg(ClO4)2) exhibits the highest ionic conductivity of ~8.4?×?10?3?S?cm?1 at room temperature (~20 °C), showing good mechanical and dimensional stability, suitable for their application in EDLCs. Activation of charcoal was done by impregnation method using potassium hydroxide (KOH) as activating agent. Brunauer–Emmett–Teller (BET) studies reveal that the effective surface area of treated activated charcoal powder (1,515 m2?g?1) increases by more than double-fold compared to the untreated one (721 m2?g?1). Performance of EDLCs has been tested using cyclic voltammetry, impedance spectroscopy, and charge–discharge techniques. Analysis shows that chemically treated activated charcoal electrodes have almost triple times more capacitance values as compared to the untreated one. 相似文献