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121.
G.?Rajasudha D.?Rajeswari B.?Lavanya R.?SaraswathiEmail author S.?Annapoorni N.?C.?Mehra 《Colloid and polymer science》2005,283(5):575-582
Polyindole dispersions consisting of 20–30-nm-sized nanoparticles are prepared by chemical oxidation with ferric chloride using sodium dodecyl sulphate, poly(vinyl alcohol) and poly(vinyl acetate) as steric stabilizers. Pure acetonitrile and acetonitrile–water mixtures are used as solvents. The particle size depended on the concentrations of monomer and the steric stabilizer. The dispersions are characterized by scanning electron microscopy, transmission electron microscopy, Fourier transform IR spectroscopy, thermal analysis and cyclic voltammetry techniques. 相似文献
122.
K. V. Vimalnath A. Rajeswari K. C. Jagadeesan C. Viju P. V. Joshi Meera Venkatesh 《Journal of Radioanalytical and Nuclear Chemistry》2012,294(1):43-47
64Cu is an useful radionuclide for both PET imaging and targeted therapy, as it decays by three different modes, namely, electron capture (41%), ??? (40%) and positron emission (19%). 64Cu is generally produced by 64Ni (p, n) reaction in a cyclotron for medical use. High specific activity ??no carrier added?? grade 64Cu by 64Zn (n, p) route is an alternative for research studies and was hence explored. 10?mg zinc foil target (48.63% in 64Zn) was irradiated in the medium flux reactor Dhruva at a thermal neutron flux of ~5.6?×?1013 n?cm?2?s?1 for 3?days. The irradiated Zn foil was dissolved in 5?mL 10?M HCl and 64Cu was separated by anion exchange chromatography (Dowex 1?×?8; 100?C200 mesh) at 3?M HCl conditions. 64Cu radioactivity content and its radionuclide purity were ascertained by ??-ray spectrometry using HPGe detector coupled to a 4?K multichannel analyser system. Radiochemical separation yielded a radionuclidic purity of 99.9% 64Cu. 相似文献
123.
Rajeswari Yogamalar Vellusamy Mahendran Ramasamy Srinivasan Dr. Ali Beitollahi R. Pradeep Kumar Dr. Arumugam Chandra Bose Dr. Ajayan Vinu 《化学:亚洲杂志》2010,5(11):2379-2385
The preparation of needle‐shaped SnO2 nanocrystals doped with different concentration of nickel by a simple sol–gel chemical precipitation method is demonstrated. By varying the Ni‐dopant concentration from 0 to 5 wt %, the phase purity and morphology of the SnO2 nanocrystals are significantly changed. Powder XRD results reveal that the SnO2 doped with a nickel concentration of up to 1 wt % shows a single crystalline tetragonal rutile phase, whereas a slight change in the crystallite structure is observed for samples with nickel above 1 wt %. High resolution scanning electron microscopy (HRSEM) results reveal the change in morphology of the materials from spherical, for SnO2, to very fine needle‐like nanocrystals, for Ni‐doped SnO2, annealed at different temperatures. The gas sensing properties of the SnO2 nanocrystals are significantly enhanced after the nickel doping. 相似文献
124.
A detailed study of point contact tunnelling into ceramic YBCO with electrochemically etched tips of Pt, Nb and W is reported.
The superconducting gap parameter (Δ) has been extracted fromI —V and dI/dV —V curves using various procedures. Our results indicate a gap value of about 20 meV. We observe that the zero bias conductance
is strongly dependent on the junction resistance. The normal state conductance varies linearly with bias voltage and the conductance
curves are asymmetric with respect to polarity of the bias voltage. With contacts of very high junction resistance, we observe
G(0)/G(100 mV) has a value as low as 1/6. This may be the lowest value reported so far. 相似文献
125.
Role of Cyanex-272 as an extractant for uranium in the determination of rare earths by ICP-AES 总被引:2,自引:0,他引:2
B. Rajeswari B. A. Dhawale T. R. Bangia J. N. Mathur A. G. Page 《Journal of Radioanalytical and Nuclear Chemistry》2002,254(3):479-483
A chemical separation procedure has been developed for the extraction of uranium from some of the crucially important rare earths using a novel extractant viz. Cyanex-272 (2,4,4-trimethyl pentyl phosphinic acid). The near total extraction of uranium and quantitative separation of rare earth elements has been validated using inductively coupled argon plasma - atomic emission spectrometry (ICP-AES). The recovery of some of the representative elements has been confirmed by radioactive tracer studies. The back extraction of uranium from the organic phase was carried out using a solution of 0.5M Na2CO3 which resulted in a near total recovery of uranium into the organic phase. These studies have enabled determination of sub ppm amounts of the analyte elements with a precision of 5% RSD utilizing prior chemical separation of rare earths from 1 g uranium samples in just three extractions with Cyanex-272. 相似文献
126.
V. Natarajan B. Rajeswari B. A. Dhawale N. S. Hon S. V. Godbole V. K. Manchanda 《Journal of Radioanalytical and Nuclear Chemistry》2009,280(1):27-31
Energy dispersive X-ray fluorescence (EDXRF) spectrometric methods have been developed for the determination of some common
metallic impurities in ThO2 matrix. A series of ThO2 standards containing the analyte impurities in the range 10–100 (or 100–500) μg/g was prepared synthetically. The spectrometer
conditions were optimized to obtain calibration plots for the various analytes. The accuracy and precision of the developed
methodology for regular assay of ThO2 was evaluated by analyzing three synthetic samples. Further three secondary ThO2 standards were analyzed by EDRXF to check the developed methods. The determined concentrations of Ca, Cr, Fe, Ni and Cu were
in good agreement with the certified values of the secondary standards. 相似文献
127.
128.
K. V. Vimalnath A. Rajeswari Viju Chirayil P. L. Sharad K. C. Jagadeesan P. V. Joshi Meera Venkatesh 《Journal of Radioanalytical and Nuclear Chemistry》2011,290(1):221-225
64Cu (t1/2 12.7 h) is a versatile radionuclide owing to its unique decay scheme and exhibits three types of decay electron capture (41%),
β− (40%), β+ (19%) that is useful in nuclear medicine applications. Different batches of natural copper oxide (CuO) and 99.9% enriched
63CuO targets were irradiated in research reactors at a neutron flux of 6.6 × 1012 n cm−2 s−1 for duration of 3 days. Irradiated samples dissolved in hydrochloric acid solution were measured in HPGe-MCA system, the
activity of 64Cu, co-produced radionuclide impurities and radionuclide purity was determined. Average specific activity of 254 GBq 64Cu per g Cu and ~348 GBq 64Cu per g Cu was recorded at the end of irradiation from natural and enriched CuO targets, respectively. 相似文献
129.
Rajeswari Gopal Geetha Sivakumar Krishnankutty Nair Chandrika Gayathri G. Saraswathy Asha Nair Sivakumari Manjula Sakuntala 《Molecules (Basel, Switzerland)》2021,26(8)
Osmotin, a plant defense protein, has functional similarity to adiponectin, an insulin sensitizingsensitising hormone secreted by adipocytes. We speculated that Piper colubrinum Osmotin (PcOSM) could have functional roles in obesity-related cancers, especially breast cancer. Immunofluorescence assays, flow cytometry, cell cycle analysis and a senescence assay were employed to delineate the activity in MDAMB231 breast cancer cell line. PcOSM pre-treated P. nigrum leaves showed significant reduction in disease symptoms correlated with high ROS production. In silico analysis predicted that PcOSM has higher binding efficiency with adiponectin receptor compared to adiponectin. PcOSM was effectively taken up by MDAMB231 cancer cells which resulted in marked increase in intracellular ROS levels leading to senescence and cell cycle arrest in G2/M stage. This study provides evidence on the ROS mediated direct inhibitory activity of the plant derived osmotin protein on the phytopathogen Phytophthora capsici, and the additional functional roles of this plant defense protein on cancer cells through inducing ROS associated senescence. The strong leads produced from this study could be pursued further to obtain more insights into the therapeutic potential of osmotin in human cancers. 相似文献