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811.
Background
Glioblastoma multiforme (GBM) is the most frequently encountered brain cancer. Although the existence of cancer stem cells in GBM has been previously established, there is little evidence to explain the difference between cancer stem cells and radio-resistant cells in GBM. In an effort to increase our understanding of whether cellular radio-resistance is a characteristic associated with cancer stem cells, we developed a dissociated cell system of subpopulations derived from GBM, and demonstrated radiotherapy resistance therein. 相似文献812.
813.
In this work, we evaluate the physical properties of nylon 6 nonwoven mats produced from solutions with formic acid. Nonwoven electrospun mats from various solutions with different concentration are examined regarding their morphology, pore size, surface area, and gas transport properties. Each nonwoven mat with average fiber diameters from 90 to 500 nm was prepared under controlled electrospinning process parameters. From the results, it was observed that the fiber diameter was strongly affected by the polymer concentration (polymer viscosity). In additional the results showed that the pore size, Brunauer-Emmett-Teller (BET) surface area, and gas transport property of electrospun nylon 6 nonwoven mats were affected by the fiber diameter. 相似文献
814.
Seung Uk Son Do Han Kim Il Gu Jung Young Keung Chung Sueg‐Geun Lee Sung‐Ho Chun 《Journal of polymer science. Part A, Polymer chemistry》2003,41(1):76-83
New norbornene derivatives synthesized from Pauson–Khand reaction products were homopolymerized and copolymerized with norbornene with an allyl–palladium complex as a catalyst. The ketone group was tolerated by the polymerization reaction. Monomers bearing protected alcohols were easily homopolymerized. Most of the homopolymers were soluble in tetrahydrofuran, CH2Cl2, toluene, and cyclohexane. As the steric bulkiness of the substituent increased, the chain length of the homopolymer decreased. Copolymers with a molecular weight of up to 153,800 were formed and were soluble in tetrahydrofuran, CH2Cl2, toluene, and diethyl ether. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 76–83, 2003 相似文献
815.
Jong Min Park Ok Jae Shon Hyuck-gi Hong Jong Seung Kim Yangsun Kim H.B. Lim 《Microchemical Journal》2005,80(2):139-144
A microchip metal ion sensor based on absorption of a novel 1,3-alternate calix[4]azacrown having a dinitro-azo-chromophoric pendent group, which was synthesized in this group, was manufactured and its performance was discussed. The microchip optical sensor was composed of light emitting diode (LED, 516.6 nm peak max.) as a light source, photodiode detector, and polydimethyl siloxane (PDMS) microchannel copied from a master of Si wafer. It turns out that dinitro-azocalix[4]azacrown (DAC) can make a complex with various metal ions, such as Na+, Ca2+, Cu2+, and Fe2+, based on the fundamental study of spectrochemical properties for optical sensing. The absorption signal was stable and dependent upon concentration of metal ions. Limit of detection for Na+ was obtained to be 78.4 ng/mL with relative standard deviation of 2.24%. 相似文献
816.
M. A. Lazovskaya S. N. Baranov A. K. Sheinkman A. A. Rok 《Chemistry of Heterocyclic Compounds》1971,7(5):559-560
N-Pyridylethylated derivatives were obtained by the reaction of- or-vinylpyridines with 4-azolidones and their 5-benzylidene-substituted derivatives. Their IR and UV spectra were studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 599–600, May, 1971. 相似文献
817.
818.
Masayuki Kirihara Aiko Harano Hiroyuki Tsukiji Ryu Takizawa Tomoyuki Uchiyama Akihiko Hatano 《Tetrahedron letters》2005,46(37):6377-6380
Dithioacetals can be deprotected to afford carbonyl groups using the tantalum(V) chloride catalyzed oxidation of iodide ion by hydrogen peroxide under mild conditions. 相似文献
819.
820.
Y. Byun Y. Lee J. Park J. S. Ryu 《Proceedings of the American Mathematical Society》2001,129(4):1161-1168
We show that, on an oriented Riemannian 4-manifold, existence of a non-zero parallel spinor with respect to a spin structure implies that the underlying smooth manifold admits a Kähler structure. A similar but weaker condition is obtained for the 4-manifold to admit a symplectic structure. We also show that the structure in which the non-zero parallel spinor lives is equivalent to the canonical spin structure associated to the Kähler structure.