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801.
802.
Lignans are imporant active ingredients of Schisandra sphenanthera. A micellar electrokinetic chromatography method was developed for the simultaneous determination of eight lignans--schizandrin, schisandrol B, schisantherin A, schisanhenol, anwulignan, deoxyschizandrin, schizandrin B and schizandrin C--in different parts of S. sphenanthera. The key factors for separation and determination were studied and the best analysis conditions were obtained using a background electrolyte of 10 mM phosphate-37.5 mM SDS-35% v/v acetonitrile (pH 8.0) at the separation voltage of 28 kV and detection at 214 nm, whereby the plant samples could be analyzed within 9.0 min. Analysis yielded good reproducibility (RSD between 1.19-2.28%) and good recovery (between 92.2-103.8%). The detection limits (LOD) and limit of quantification (LOQ) were within 0.4-1.2 mg/L and 1.5-4.0 mg/L. This method is promising to improve the quality control of different parts of S. sphenanthera. 相似文献
803.
Zhang Y Tan M Li H Zheng Y Gao S Zhang H Ying JY 《Chemical communications (Cambridge, England)》2011,47(26):7365-7367
Novel mesoscopic organic nanosheets were developed by functionalizing bulk 2D organic covalent framework polymers with small molecules. The water-soluble fluorescent nanosheets are promising as nanocarriers for biological applications. 相似文献
804.
805.
In this paper, we consider the heat flow for the Hsystem with constant mean curvature in higher dimensions. We give sufficient conditions on the initial data such that the heat flow develops finite time singularity. We also provide a new set of initial data to guarantee the existence of global regular solution to the heat flow, that converges to zero in W 1,n with the decay rate t 2/(2-n) as time goes to infinity. 相似文献
806.
ChangLing Tan ZhenBing Tan Li Ma FanMing Qu Fan Yang Jun Chen GuangTong Liu HaiFang Yang ChangLi Yang Li Lu 《中国科学G辑(英文版)》2009,52(9):1293-1298
We have studied the electron transport properties of a disordered graphene sample, where the disorder was intentionally strengthened
by Ga+ ion irradiation. The magneto-conductance of the sample exhibits a typical two-dimensional electron weak localization behavior,
with electron-electron interaction as the dominant dephasing mechanism. The absence of electron anti-weak localization in
the sample implies strong intersublattice and/or intervalley scattering caused by the disorders. The temperature and bias-voltage
dependencies of conductance clearly reveal the suppression of conductance at low energies, indicating opening of a Coulomb
gap due to electron-electron interaction in the disordered graphene sample.
Supported by the National Natural Science Foundation of China (Grant Nos. 10774172 and 10874220), and the National Basic Research
Program of China from the MOST (Grant No. 2006CB921304) 相似文献
807.
An efficient synthesis of 9,10-phenanthrenequinones is described. The two carbonyl groups were introduced by an orthoselective intermolecular Friedel-Crafts reaction of 3-methoxyphenol with ethyl chlorooxoacetate. The formation of a biaryl bond by Suzuki-Miyaura coupling reaction, followed by the hydrolysis of the ester, gave a biaryloxoacetic acid. Treatment of this acid with CDI gave the corresponding imidazolide. The ring closure to the desired phenanthrenequinone was accomplished by intramolecular Friedel-Crafts reaction of the imidazolide promoted by TiCl(4). 相似文献
808.
Gang Liu Yan‐Hu Li Wan‐Yi Tan Zhi‐Cai He Xiao‐Tie Wang Chi Zhang Prof. Yue‐Qi Mo Prof. Xu‐Hui Zhu Prof. Junbiao Peng Prof. Yong Cao 《化学:亚洲杂志》2012,7(9):2126-2132
A new series of monoammonium‐based organic electrolytes with the tetrafluoroborate (BF4?) counteranion have been synthesized. Replacing the pendant ethyl groups in the fluorenyl unit with 4‐ethoxyphenyl groups dramatically improves both solubility and morphological stability. The characterization of the alcohol‐processable amorphous ionic compounds as an electron‐injection layer in organic light‐emitting diodes (OLEDs) reveals that the organic electrolyte that comprises a rigid linear‐conjugated unit provides better device performance, with respect to its counterpart containing a branched bulky moiety. The capability of these compounds to facilitate electron injection from air‐stable aluminum metal is preliminarily discussed on the basis of the investigations of the electron‐only devices and photovoltaic experiments. 相似文献
809.
Da Zhang Youshi Zheng Ziguo Lin Xiaolong Liu Juan Li Huanghao Yang Weihong Tan 《Angewandte Chemie (International ed. in English)》2020,59(29):12022-12028
Herein, we propose an aptamer‐equipping strategy to generate specific, universal and permeable (SUPER) NK cells for enhanced immunotherapy in solid tumors. NK cells were chemically equipped with TLS11a aptamer targeting HepG2 cells and PDL1‐specific aptamer without genetic alteration. The dual aptamer‐equipped NK cells exhibited high specificity to tumor cells, resulting in higher cytokine secretion and apoptosis/necrosis compared to parental or single aptamer‐equipped NK cells. Interestingly, dual aptamer‐equipped NK cells induced remarkable upregulation of PDL1 expression in HepG2 cells, enhancing checkpoint blockade. Furthermore, in vivo intravital imaging demonstrated high infiltration of aptamer‐equipped NK cells into deep tumor region, leading to enhanced therapeutic efficacy in solid tumors. This work offers a straightforward chemical strategy to equip NK cells with aptamers, holding considerable potential for enhanced adoptive immunotherapy in solid tumors. 相似文献
810.
Gaussian 98在有机化学教学中的应用 总被引:4,自引:0,他引:4
Gaussian 98软件可以展示反应的途径及反应机理,能够计算反应的相关数据,尤其是该软件在有机化学教学中的应用,更能显示出在教学中的应用优势. 相似文献