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41.
Zepf M Clark EL Beg FN Clarke RJ Dangor AE Gopal A Krushelnick K Norreys PA Tatarakis M Wagner U Wei MS 《Physical review letters》2003,90(6):064801
Measurements of energetic proton production resulting from the interaction of high-intensity laser pulses with foil targets are described. Through the use of layered foil targets and heating of the target material we are able to distinguish three distinct populations of protons. One high energy population is associated with a proton source near the front surface of the target and is observed to be emitted with a characteristic ring structure. A source of typically lower energy, lower divergence protons originates from the rear surface of the target. Finally, a qualitatively separate source of even lower energy protons and ions is observed with a large divergence. Acceleration mechanisms for these separate sources are discussed. 相似文献
42.
Karthik Arumugam Mallikarjuna Rao Chamallamudi Ravindranath Reddy Gilibili Ramesh Mullangi Subramanian Ganesan Sidhartha S Kar Ranjithkumar Averineni Gopal Shavi Nayanabhirama Udupa 《Biomedical chromatography : BMC》2011,25(3):353-361
A sensitive, specific and accurate HPLC method for the quantification of rivastigmine (RSM) in rat urine was developed and validated. The method involves the simple liquid–liquid extraction of RSM and pyridostigmine as an internal standard (IS) from rat urine with tertiary methyl butyl ether. The chromatographic separation of RSM and IS was achieved with 20 mm ammonium acetate buffer (pH 6.5) and acetonitrile (65:35, v/v) delivered at flow‐rate of 1 mL/min on a Kromasil KR‐100. The method was in linear range from 50 to 5000 ng/mL. The validation was done as per FDA guidelines and the results met the acceptance criteria. The method was successfully applied for the quantification of RSM in rat urine. Besides method validation, we have identified two metabolites of RSM in urine. Both the metabolites were characterized by HPLC‐PDA and LC‐MS/MS and it was found that one metabolite is novel. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
43.
Kuldeep Sharma Gopal V. Pawar Sanjeev Giri Sriram Rajagopal Ramesh Mullangi 《Biomedical chromatography : BMC》2012,26(12):1589-1595
A highly sensitive, rapid assay method has been developed and validated for the estimation of bicalutamide in mouse plasma using liquid chromatography coupled to tandem mass spectrometry with electrospray ionization in the negative‐ion mode. The assay procedure involves extraction of bicalutamide and tolbutamide (internal standard, IS) from mouse plasma with a simple protein precipitation method. Chromatographic separation was achieved using an isocratic mobile phase (0.2% formic acid:acetonitrile, 35:65, v/v) at a flow rate of 0.5 mL/min on an Atlantis dC18 column (maintained at 40 ± 1°C) with a total run time of 3.0 min. The MS/MS ion transitions monitored were m/z 428.9 → 254.7 for bicalutamide and m/z 269.0 → 169.6 for IS. Method validation was performed as per FDA guidelines and the results met the acceptance criteria. The lower limit of quantitation achieved was 1.04 ng/mL and the linearity range extended from 1.04 to 1877 ng/mL. The intra‐ and inter‐day precisions were in the ranges of 0.49–4.68 and 2.62–4.15, respectively. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
44.
45.
Gowravaram Sabitha Narjis Fatima Peddabuddi Gopal C. Nagendra Reddy Jhillu S. Yadav 《Tetrahedron: Asymmetry》2009,20(2):184-191
Prins and olefin cross-metathesis reactions were used as the key steps for the stereoselective total synthesis of (+)-strictifolione and (6R)-6-[(4R,6R)-4,6-dihydroxy-10-phenyldec-1-enyl]-5,6-dihydro-2H-pyran-2-one. Removal of MOM protecting groups under neutral conditions using CeCl3·7H2O is an attractive addition to the present strategy. 相似文献
46.
A method for generating aperiodic tilings with five fold symmetry is discussed here. Basic patterns formed within decagons
can be used to fill two dimensional space, by matching such suitable patterns. It appears to be possible to generate perfect
tilings without retracing already established coordinates imposing conditions at the initial stages of generating them. Various
possible ways to generate tilings, when perfectness is not required, are discussed. The calculated diffraction patterns for
some representative finite size tilings are shown. There are subtle differences in the intensities of peaks in the diffraction
patterns corresponding to different finite size tilings constructed using intersecting decagons. These effects persist for
a larger number of scatterers in weak peaks than in strong peaks. They are unaffected by an introduction of systematic disorder.
These effects could be termed as the finite size boundary effects. There are also small shifts in the peak positions owing
to the finite size effects. The possibility of formation of large approximate square cells in large tilings is shown. 相似文献
47.
Ramdas S. Pathare Shivani Sharma Kandasamy Gopal Devesh M. Sawant Ram T. Pardasani 《Tetrahedron letters》2017,58(14):1387-1389
An efficient one-pot protocol for the synthesis of multi-substituted 2-pyrone derivatives from internal alkynes and unactivated alkenes is reported. The methodology involves difunctionalization of internal alkynes by using Pd(II) as a catalyst alongwith X-Phos as ligand via 6-endo transesterification and subsequent alkenylation pathway. Notable features include simple and easily available starting materials, including a range of unactivated alkenes, reduced synthetic steps and mild reaction conditions with high efficiency. 相似文献
48.
Sanjay K. Bharti Saurabh K. Patel Gopal Nath Ragini Tilak Sushil K. Singh 《Transition Metal Chemistry》2010,35(8):917-925
Six Cu(II) complexes of Schiff base ligands of arylidene-2-(4-(4-bromo/methoxy-phenyl)thiazol-2-yl) hydrazines have been synthesized,
characterized and screened for DNA cleavage and antimicrobial activities. The chemical structures of the complexes were deduced
by physicochemical and spectroscopic methods. Elemental analyses indicated that the stoichiometry of the complexes is CuL2 (L = Schiff base ligand). The DNA cleavage activities of the complexes were evaluated by agarose gel electrophoresis in the
presence and absence of oxidant (H2O2) and free radical scavenger (DMSO). All the six complexes showed significant nuclease activity in the presence of H2O2, and two of the complexes showed moderate nuclease activity even in the absence of oxidant. The complexes did not show nuclease
activity in the presence of free radical scavenger. The compounds were tested for activity against selected bacteria and fungi. 相似文献
49.
Gowravaram Sabitha C. Nagendra Reddy Peddabuddi Gopal J.S. Yadav 《Tetrahedron letters》2010,51(43):5736-5739
A convergent stereoselective total synthesis of (+)-anamarine via cross-metathesis (CM) protocol starting from 2-butyn-1,4-diol and vinyl lactone is reported. Other key features of the strategy include the use of Sharpless asymmetric epoxidation, Sharpless dihydroxylation, and Red-Al reduction. 相似文献
50.
Murugan R Mallavarapu GR Padmashree KV Rao RR Livingstone C 《Natural product communications》2010,5(12):1961-1964
The volatile oil of the leaves of Pogostemon heyneanus Benth. (Lamiaceae) was analyzed by GC and GC-MS. Twenty-six components representing 96.0% of the oil were identified. The major components of the oil were acetophenone (51.0%), beta-pinene (5.3%), (E)-nerolidol (5.4%), and patchouli alcohol (14.0%). Comparison of the compositions of the oils of P. heyneanus and P. cablin (Blanco) Benth. (Patchouli oil) showed wide variation between them. Though 13 sesquiterpenes and oxygenated sesquiterpenes were detected in both oils, their concentrations in the oils differed widely. Acetophenone, benzoyl acetone and (E)-nerolidol present in the oil of P. heyneanus were not detected in patchouli oil. 相似文献