排序方式: 共有110条查询结果,搜索用时 15 毫秒
71.
Sarita Roy Soumen Basak Pulak Ray Anjan Kr. Dasgupta 《Photonics and Nanostructures》2012,10(4):506-515
Surface plasmon resonance (SPR) for spherical shaped silver nanoparticles showing double maxima at ~390 nm and ~520 nm respectively is reported. Self assembly of silver nanoparticles grown on tryptophan template leads to emergence of equal intensity double plasmon resonance (EIDPR). While for rod shaped nano-forms such double plasmon is explainable but for spherical shaped forms, such double plasmon can be explained on the basis of bidirectional formation of silver cluster in which attachment of silver at two nitrogen atom locations of tryptophan molecule seems to be obligatory. The absence of double resonance in case of silver nanoclusters formed with other amino acids or N-acetyl l-tryptophanamide (NATA), where bidirectional NH2 attachment is not possible, validates the proposed EIDPR mechanism. Electron micrograph of EIDPR particle indicates a bi-periodic fringe pattern indicating unusual crystalline property. Apart from sensing tryptophan, the double plasmon peaks are sensitive to temperature. Furthermore, the particle can be used as a smart killing agent showing bactericidal activity only upon exposure to low power laser. 相似文献
72.
73.
74.
Sarita Mishra 《合成通讯》2013,43(15):2229-2244
An efficient one-pot, multicomponent synthesis of 3,5-dicyanopyridines has been developed from the reaction of malononitrile and different thiophenol or thiols with a variety of aldehydes (aromatic including hindered ones, heteroaromatic, and aliphatic) in the presence of 20 mol% of K2CO3 in refluxing 50% aqeuous ethanol. KMnO4 has been utilized as a readily available, inexpensive oxidant for the in situ transformation of the initially formed dihydropyridine intermediate. K2CO3 also mediates the one-pot formation of chromeno[2,3-b]pyridines from reaction of salicylaldehyde or its analogs with malononitrile and thiol or thiophenols. Both of these conditions also work equally well under 50-fold scale-up conditions. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file. 相似文献
75.
Shweta Mehrotra Shailendra Goel Sarita Sharma Soom Nath Raina Vijay Rani Rajpal 《Applied biochemistry and biotechnology》2013,169(4):1109-1125
Repetitive DNA sequences constitute a significant proportion of eukaryotic genomes. Knowledge about the distribution of repetitive DNA sequences is necessary in order to gain insights into the organization, evolution and behavior of eukaryotic genomes. Therefore, we used two repetitive DNA sequences pCtKpnI-I and pCtKpnI-II, earlier reported in Carthamus tinctorius L. to study the phylogeny and to revise the taxonomic status of the taxa belonging to the genus. The study unraveled two major lines within the genus Carthamus; one line included all the diploid taxa (2n?=?24) and the other line comprised the taxa with 2n?=?20 and the polyploid taxa (2n?=?44 and 64). The results of the present study will prove useful in molecular breeding for improving some targeted agronomic traits in genus Carthamus. 相似文献
76.
Pooja Varshney Sarita Afaq Ahmad Saba Beg 《Journal of Physics and Chemistry of Solids》2006,67(11):2305-2309
Electrical conductivity of ZrO2 doped with Pb3O4 has been measured at different temperatures for different molar ratios (x=0, 0.01, 0.02, 0.03, 0.04, 0.05 and 0.06). The conductivity increases due to migration of vacancies, created by doping. The conductivity increases with increase in temperature till 180 °C and thereby decreases due to collapse of the fluorite framework. A second rise in conductivity at higher temperatures beyond 500-618 °C is due to phase transition of ZrO2. DTA and X-ray powder diffraction were carried out for confirming doping effect and transition in ZrO2.The addition of Pb3O4 to ZrO2 shifted the phase transition of ZrO2 due to the interaction between Pb3O4 and ZrO2. 相似文献
77.
In this paper, sufficient optimality conditions for a multiobjective subset programming problem are established under generalized
-type-I functions. 相似文献
78.
A simple, accurate and reproducible reverse-phase HPLC method has been developed for identification and quantification of two isomeric coumarinolignoids, cleomiscosin A and B in different extracts of the seeds of Cleome viscosa using photodiode array detection at 326 nm. Cleomiscosin A and B were separated on a Waters symmetry C(18) column (250 x 4.6 mm with 5.0 microm particle size) with an isocratic elution system composed of acetonitrile-methanol (1:2, v/v) and acetic acid-water (0.5:99.5, v/v) in the ratio of 40:60 (v/v). The calibration curves were linear (r(2) > 0.997) in the concentration ranges of 20-100 microg/mL for both compounds. The limits of detection and quantification were 15 and 20 microg/mL for both cleomiscosin A and B. The intra- and inter-day precisions were 3.68 and 2.22% for cleomiscosin A and 4.22 and 5.06% for cleomiscosin B. The recoveries measured at two different concentration levels varied from 98.03 to 110.06%. The method was used to identify and quantify cleomiscosins A and B in different extracts of Cleome viscosa seeds. 相似文献
79.
P. Sarita G. J. Naga Raju S. Bhuloka Reddy 《Journal of Radioanalytical and Nuclear Chemistry》2014,302(3):1501-1506
The objective of this study was to evaluate the levels of trace elements in blood sera of uterine cervix cancer patients, analyze their alteration with respect to healthy controls and identify the best predictors amongst these for disease occurrence and progression. Particle induced X-ray emission (PIXE) technique was used in this work to identify and quantify trace elements Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Br in the blood sera of uterine cervix cancer subjects and healthy control subjects. The observed alterations are discussed with respect to the possible mechanisms by which these elements might influence the carcinogenic process. 相似文献
80.