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101.
Shun-Jen Cheng 《Communications in Mathematical Physics》1993,154(3):555-568
LetS be a simple Lie algebra of characteristic 0 and (n) be the Grassmann superalgebra inn indeterminates. We can form the Lie superalgebraS (n). The purpose of this paper is to classify all finite dimensional irreducible representations of all central extensions ofS (n). We will also give a character formula for these representations. 相似文献
102.
Feng Deng Lizhi Xiao Huabing Liu Tianlin An Mengying Wang Zongfu Zhang Wei Xu Jiajie Cheng Qingming Xie Vladimir Anferov 《Applied magnetic resonance》2013,44(9):1053-1065
Nuclear magnetic resonance (NMR) under motion has drawn significant attention in recent years. Motion of the NMR probe has serious effects on NMR measurement. For example, NMR logging normally runs at downhole condition with tool motion at a speed of 30 ft/min. We propose here methods for motion corrections of NMR data based on the quantitative analysis of motion effects on polarization and echo acquisition. We also produced a multi-functional NMR scanning system to verify the theoretical analysis. Presented experiments demonstrate that the theoretical and experimental results match very well. 相似文献
103.
Proteomic analysis of apoptosis initiation induced by all-trans retinoic acid in human acute promyelocytic leukemia cells 总被引:10,自引:0,他引:10
The irreversible destiny of apoptosis in its early stage might play a critical role in the apoptosis of human acute promyelocytic leukemia (APL) cell line induced by all-trans retinoic acid (ATRA). To characterize protein alterations during the apoptosis-initiation phase and to understand the metabolic status at that time, we investigated the protein profiles in the apoptosis-initiation phase of APL cell line HL-60 by proteomic analysis. ATRA-withdrawal was conducted to demonstrate that there was committed initiation phase of apoptosis triggered by 10(-6) M ATRA at day 3. Only after that time point, ATRA-treated cells irreversibly went to apoptosis. Also at that time point, the positive regulators of apoptosis such as STAT3 increased at protein level, whereas negative regulators (Bcl-2 and p-STAT3) decreased. In addition, caspase-3 also increased after that time. Furthermore, comparative proteomic analysis was utilized to examine the protein expression profiles during the initiation stage of apoptosis. Our results showed 12 upregulated and 7 downregulated proteins experiencing twofold alteration, including key regulators of signal transduction such as G-proteins and nucleic receptors, proteins related with metabolism, oxidation and reduction, proteins associated with the nucleus and cytoskeleton-related proteins. Some of them could be positive modulators to trigger apoptosis, whereas others could contribute to intracellular defense against apoptosis induced by exogenous triggers. The results above suggest that there is a subtle balance between apoptosis and the intracellular defense against apoptosis. Once the balance is disturbed, cells would irreversibly initiate to undergo the execution of apoptosis. 相似文献
104.
The electron‐donating unit 2,3,4,6‐tetrahydro‐1,6‐dithia‐3a‐azaphenalene (THDTAP) was introduced onto terpyridine (TPy) to give a donor‐acceptor (D‐A) type TPy‐ligand (compound 2 ). Upon selective oxidation of two sulfur atoms on the THDTAP moiety of 2 , the ligands 3 — 6 were created. The electronic structures of 2 — 6 were evaluated by theoretical, electrochemical, and spectroscopic investigations. The oxidation on the sulfur atoms brings significant influence on the electron‐donating ability of THDTAP moiety, subsequently, leads to fine modulations on intramolecular charge‐transfer (ICT) of 2 — 6 and the electronically excited states of the complexes of 2 — 6 with metal ions. Based on the optical response of 2 — 6 toward metal ions, the step‐by‐step recognition of Zn2+, Cd2+, and Ag+ ions is set up by employing 2 and 3 as combined fluorescence sensors. 相似文献
105.
Cheng CH Juttu G Mitchell SF Shantz DF 《The journal of physical chemistry. B》2006,110(43):21430-21437
The synthesis, characterization, and growth of Ge-silicalite-1 from optically clear solutions are reported. Ge-silicalite-1 is readily formed from optically clear solutions of TEOS, TPAOH, water, and a germanium source at 368 K. X-ray fluorescence (XRF) is used to determine the Si/Ge ratio and indicates that germanium inclusion is typically 30-50% of that in the actual mixture. Adsorption, power X-ray diffraction (PXRD), and 29Si NMR indicate the materials are crystalline and microporous. In situ small-angle X-ray scattering (SAXS) is applied to investigate the influences of germanium source (GeO2 and Ge(OC2H5)4) and content (Si/Ge 100:5) on the growth of Ge-silicalite-1 from clear solutions at 368 K. The in situ SAXS investigations show that for solutions with Si/Ge ratios of 100, 50, and 25 using Ge(OC2H5)4 the induction periods are approximately 6 h and the particle growth rates are 1.82 +/- 0.04, 2.52 +/- 0.13, and 2.85 +/- 0.08 nm/h, respectively, at 368 K, compared to those of pure silicalite-1 (6 h induction period, 1.93 +/- 0.1 nm/h growth rate). Further increasing the Si/Ge ratio to 15 and 5 shortens the induction period to approximately 4.5 h, and the growth rates are 3.07 +/- 0.16 and 2.05 +/- 0.10 nm/h, respectively, indicating the Si/Ge ratio that maximizes Ge-silicalite-1 growth is between 25 and 15. Similar trends are obtained with germanium oxide; however, the growth rates are all consistently larger than those for syntheses with Ge(OC2H5)4. The results indicate that Ge-silicalite-1 growth rates in the presence of germanium are increased as compared to those of pure-silica syntheses. 相似文献
106.
Resonance light scattering technique used for biochemical and pharmaceutical analysis 总被引:6,自引:0,他引:6
By coupling and scanning simultaneously excitation and the emission monochromators of a common spectrofluorometer, enhanced resonance light scattering (RLS) signals could be obtained. The enhanced RLS signals could be used for designating bio-assemblies, aggregation species, and analytical purposes. Herein, we review the reports since the year of 2000 concerning the biochemical and pharmaceutical analysis with the RLS measurements, and discuss the possible developments of this technique. 相似文献
107.
Cheng X Vellalath S Goddard R List B 《Journal of the American Chemical Society》2008,130(47):15786-15787
A highly enantioselective Br?nsted acid catalyzed direct synthesis of cyclic aminals from aldehydes has been developed. The methodology has been applied to the first asymmetric synthesis of several antihypertensive aminal drugs including (R)-Thiabutazide. 相似文献
108.
Chorng‐Shyan Chern Cheng‐Kang Lee Chia‐Che Ho 《Journal of polymer science. Part A, Polymer chemistry》1999,37(10):1489-1499
Stable chitosan‐modified polymethyl methacrylate (PMMA) latex particles were prepared by using 2,2′‐azobis(2‐amidinopropane) dihydrochloride (V‐50) as the cationic initiator. The polymerization rate (Rp) is controlled by the V‐50 concentration ([V‐50]) and Rp is less sensitive to the chitosan concentration ([C]) used in the synthesis work. The reaction system follows Smith–Ewart Case III kinetics due to the relatively large particles produced. The zeta potential data show that the isoelectric point (pI) of the latex particles is 10.7. The amounts of V‐50 (CV‐50) and chitosan (Cc) ultimately incorporated into the particles correlate reasonably well with [V‐50] and [C], respectively. At pH 7, the quantity of the negatively charged bovine serum albumin (BSA, pI = 4.8) adsorbed on the positively charged chitosan‐free particles (Q) via the electrostatic interaction increases with increasing CV‐50. However, Q is relatively insensitive to changes in Cc. This result implies that only the outermost region of the hairy chitosan‐modified particles is available for adsorption of the relatively large protein species. Colloidal stability shows a significant influence on the BSA adsorption process. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1489–1499, 1999 相似文献
109.
Zhaoyang Zhang Xinxin Xue Chuangshe Li Sijing Cheng Lei Han Haixia Chen Huaibin Zheng Yanpeng Zhang 《Optics Communications》2012,285(17):3627-3630
We demonstrate the coexisting four-wave mixing (FWM) signal and six-wave mixing (SWM) signal which can be enhanced both by electromagnetically induced transparency (EIT) and optical pumping effect in a common three-level and open four-level inverted-Y type systems of 85Rb. We also analyze the effect of optical pumping in different energy level systems by arranging laser beams and comparing the strength of the increased and reduced absorption caused by optical pumping. 相似文献
110.
A locally convex space is said to be a Gateaux differentiability space (GDS) provided every continuous convex function defined on a nonempty convex open subset D of the space is densely Gateaux differentiable in .D.This paper shows that the product of a GDS and a family of separable Prechet spaces is a GDS,and that the product of a GDS and an arbitrary locally convex space endowed with the weak topology is a GDS. 相似文献