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21.
U. Pandey S. Banerjee A. Mukherjee H. D. Sarma M. Venkatesh 《Journal of Radioanalytical and Nuclear Chemistry》2007,273(3):719-723
Several human tumors such as neuroendocrine tumors, medullary thyroid carcinoma, etc., express somatostatin receptors which
specifically bind somatostatin and its analogues such as lanreotide, octreotide, etc. In order to prepare a therapeutic agent
for targeting such tumors, attempts were made to prepare 90Y-DOTA-Lanreotide. Lanreotide could be successfully conjugated with the macrocyclic chelating agent DOTA (1,4,7,10-tetraaza
cyclododecane tetracetic acid) which forms stable complexes with 90Y. 90Y-DOTA-Lanreotide could be prepared in >98% radiochemical purity and remained stable for 72 hours at room temperature. The
tracer showed specific binding to A431 cells. Biodistribution studies in C57BL6 mice bearing melanoma showed ∼1.3% uptake
pergram of tumor at 24-hour p.i. 相似文献
22.
Alternating copolymer(s) containing geraniol and styrene sequences have been synthesized by using benzoyl peroxide as initiator in xylene at 80 °C. The copolymerisation follows ideal kinetics. The formation of the copolymer is confirmed by the presence of peaks at 7-7.5δ due to the phenyl group and 7-7.7δ due to the alcoholic group and 2900 cm−1 due to the phenyl groups in the FTIR spectrum of the copolymer. The values of r1(Sty)=0.76 and r2(Ger)=0.03, calculated by the Kelen-Tüdos method, indicates some alternating nature of the copolymer. The glass transition temperature (Tg) found by differential scanning calorimetry, is 90 °C. The Alfrey-price Q-e parameters for geraniol are 0.221 and 0.649. 相似文献
23.
Ribeiro da Silva MD Gomes JR Gonçalves JM Sousa EA Pandey S Acree WE 《The Journal of organic chemistry》2004,69(8):2785-2792
The mean (N-O) bond dissociation enthalpies were derived for three 2-methyl-3-(R)-quinoxaline 1,4-dioxide (1) derivatives, with R = methyl (1a), ethoxycarbonyl (1b), and benzyl (1c). The standard molar enthalpies of formation in the gaseous state at T = 298.15 K for the three 1 derivatives were determined from the enthalpies of combustion of the crystalline solids and their enthalpies of sublimation. In parallel, accurate density functional theory-based calculations were carried out in order to estimate the gas-phase enthalpies of formation for the corresponding quinoxaline derivatives. Also, theoretical calculations were used to obtain the first and second N-O dissociation enthalpies. These dissociation enthalpies are in excellent agreement with the experimental results herewith reported. 相似文献
24.
A new general one-pot method for the synthesis of various metalloporphyrins has been developed from pyrrole and substituted aldehydes using transition metal salts. This method allows higher working concentrations than those previously reported. Along with the reported metalloporphyrins, some new metalloporphyrins were synthesized in good yield. 相似文献
25.
Applicability of the cetylpyridinium (CPy(+)) cation as a selective fluorescence quenching agent for discriminating between alternant versus nonalternant polycyclic aromatic hydrocarbons (PAHs) is examined for 25 representative solutes dissolved in two aqueous micellar cetylpyridinium chloride (CPC)+zwitterionic surfactant solvent media. Experimental results show that the CPy(+) cation effectively quenched fluorescence emission of all 10 alternant PAHs studied despite the presence of strong intramicellar coulombic interactions. Emission intensities of the 15 nonalternant PAHs also decreased upon addition of CPC to the zwitterionic surfactant solutions. Reduction in emission intensities for the nonalternant PAHs is rationalized in terms of changes in micellar structure caused by the coulombic interactions, rather than from loss of quenching selectivity by the CPy(+) cation. 相似文献
26.
An investigation of the properties of poly(dimethylsiloxane)-bioinspired silica hybrids 总被引:1,自引:0,他引:1
Siddharth V. Patwardhan Vijay P. Taori Nikhil R. Agashe Gregory Beaucage Stephen J. Clarson 《European Polymer Journal》2006,42(1):167-178
Elastomers typically require the incorporation of reinforcing fillers in order to improve their mechanical properties. For commercial silicone systems silica and titania are typically used as fillers. Fumed and precipitated silica are made on an industrial scale for many applications; however, we have shown recently that biological and synthetic macromolecules can generate new silica structures using a bioinspired route. Herein we have incorporated bioinspired silica fillers into poly(dimethylsiloxane) (PDMS) elastomers and investigated their mechanical, morphological and thermal properties as a function of filler loading. The equilibrium stress-strain characteristics of the PDMS-bioinspired silica hybrids were determined as a function of bioinspired filler loading and the Mooney-Rivlin constants (2C1 and 2C2) were calculated. The thermal characteristics, in particular glass transition temperatures (Tg) and melting points (Tm), of the PDMS-bioinspired silica hybrids were characterized using differential scanning calorimetry (DSC). The thermal stability of these hybrid materials were investigated using thermogravimetric analysis (TGA). The morphology of the samples was characterized using scanning electron microscopy (SEM), and the filler dispersion was characterized using ultra small angle X-ray scattering (USAXS) and scanning electron microscopy (SEM). Although spherical silica particles were used here, we have demonstrated elsewhere that this bioinspired synthetic route also enables highly asymmetric silica structures to be prepared such as fibres and sheets. This methodology therefore offers the interesting possibility of preparing new hybrid systems where the properties are highly anisotropic. 相似文献
27.
[formula: see text] A new synthetic strategy has been developed for a general approach toward the synthesis of a variety of 1-N-iminosugar-type glycosidase inhibitors utilizing precursors developed by the PET-mediated cyclization of alpha-trimethylsilylmethylamine radical cation to a tethered pi-functionality. 相似文献
28.
N. K. Sanyal A. N. Pandey H. S. Singh B. P. Singh 《Journal of Quantitative Spectroscopy & Radiative Transfer》1970,10(12):1343-1345
The generalized mean-square amplitudes of vibration and mean amplitudes of vibration have been computed for CrO3-4, Mn18O-4, MoSe2-4 and WSe2-4 ions at three temperatures, T = 0°K, T = 298°K, T = 500°K, employing Cyvin's method. The results have been discussed in the light of atomic weight and electronegativity of the atom in the ionic system. 相似文献
29.
Beker H Boggild H Boissevain J Cherney M Dodd J Esumi S Fabjan CW Fields DE Franz A Hansen KH Holzer EB Humanic TJ Jacak BV Jayanti R Kalechofsky H Kobayashi T Kvatadze R Lee YY Leltchouk M Lörstad B Maeda N Medvedev A Miake Y Miyabayashi A Murray M Nagamiya S Nishimura S Noteboom E Pandey SU Piuz F Polychronakos V Potekhin M Poulard G Sakaguchi A Sarabura M Shigaki K Simon-Gillo J Sondheim W Sugitate T Sullivan JP Sumi Y van Hecke H Willis WJ Wolf K Xu N 《Physical review letters》1995,74(17):3340-3343
30.