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991.
Yi‐Hong Tang Guang‐Xin Xia Zhao‐Lin Sun Zhi‐Xiong Li Cheng‐Gang Huang 《Biomedical chromatography : BMC》2010,24(11):1147-1151
To profile the anti‐Coxsackie virus B3 constituents of Radix Astragali, an HPLC‐DAD‐MSn analytical method, combined with an in vivo test, has been developed to identify the constituents of the active part, which has been demonstrated to have potency to inhibit the proliferation of virus in cardiac muscle, alleviate infraction in heart and elevate the survival rate of the animal. By comparing their retention time and MS data with those obtained from the authentic compounds and the published data, a total of 19 compounds, including 11 isoflavonoids and eight saponins, were identified, among which one pterocarpane glucoside was reported for the first time. The present study provides an approach to rapidly screening bioactive constituents in traditional Chinese medicines. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
992.
AA Yan LI Kai CAO ZhongHua & HU WenRui Key Laboratory of Microgravity 《中国科学:物理学 力学 天文学(英文版)》2011,(2)
The dependency of the critical Marangoni number on the geometrical aspect ratio of the floating half zone is essential to predict the onset of oscillatory thermocapillary convection.The experimental studies in the microgravity conditions on floating half zones of several centimeters in diameter have predicted that the critical Marangoni number increases with the increasing aspect ratio,and the terrestrial experimental studies have predicted the contradictory conclusion for floating half zones of several mil... 相似文献
993.
A reusable CuSO4 · 5H2O/cationic 2,2′‐bipyridyl system catalyzed the homocoupling reaction of terminal alkynes in water using I2 as the additive in the presence or absence of tetrabutylammonium bromide, giving the 1,3‐diynes in good to high yields. After reaction, the residual aqueous solution could be reused several times. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
994.
Special crystallization event of isotactic polypropylene (iPP) in a constrained environment, a layered clay network, was followed by in situ Fourier transform infrared (FTIR) spectroscopy during the cooling process. Before occurrence of nucleation/crystallization, a conformationally ordered phase, which consists of significant amounts of long 31 helices with 14 monomeric units, has been identified for the first time. More importantly, it was found that the long‐ordering helices could play a more important role than short ones for the confined crystallization. It could be tentatively explained as due to the existence of constrained regions in the proximity of the nanoclay platelets or tactoids and the heterogeneous nucleation capability of the surface of nanoclay. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
995.
996.
CAO Ling-di FANG Yan FANG Chun-hui . Key Laboratory of Salt Resources Chemistry 《高等学校化学研究》2011,(3):490-495
Detailed time-and-space-averaged structure of MgSO4 in the concentrated aqueous solutions was investigated via X-ray diffraction with an X’pert Pro θ-θ diffractometer at 298 K, yielding structural function and radial distribution function(RDF). The developed KURVLR program was employed for the theoretical investigation in consideration of the ionic hydration and ion association. Multi-peaks Gaussian fitting method was applied to deconvolving the overlapping bands of Differential radial distribution function... 相似文献
997.
998.
Caili Fu 《Tetrahedron letters》2010,51(48):6322-6324
Oligomeric proanthocyanidins (OPCs, Ar′ = 3,4-(HO)2(C6H3) are abundant natural products found in agricultural and forestry waste such as pine bark, grape seeds, and the peels of mangosteen. We have demonstrated that the OPCs can be converted into small molecule chiral ligands by using proper nucleophiles for acid depolymerization of the OPCs. The chiral ligands may have potential for sustainable asymmetric catalysis. 相似文献
999.
给出了n次积分C半群的几个性质及其证明,讨论了它与一类抽象柯西问题存在强解的关系及强解的表示式. 相似文献
1000.
Sung Wook Kang Ok Kyun Kim Bochan Seo Sung Ho Lee Fu Shi Quan Jae Ho Shin Gi-Ja Lee Hun-Kuk Park 《Analytica chimica acta》2013
In this study, we simultaneously measured nitric oxide (NO) and oxygen (O2) dynamics in the myocardium during myocardial ischemia-reperfusion (IR) utilizing sol-gel modified electrochemical NO and O2 microsensors. In addition, we attempted to clarify the correlation between NO release in the ischemic period and O2 restoration in the myocardium after reperfusion, comparing a control heart with a remote ischemic preconditioning (RIPC)-treated heart as an attractive strategy for myocardial protection. Rat hearts were randomly divided into two groups: a control group (n = 5) and an RIPC group (n = 5, with RIPC treatment). Myocardia that underwent RIPC treatment (182 ± 70 nM, p < 0.05) released more NO during the ischemic period than those of the control group (63 ± 41 nM). The restoration value of oxygen tension (pO2) in the RIPC group significantly increased and was restored to pre-ischemic levels (92.6 ± 36.8%); however, the pO2 of the control group did not increase throughout the reperfusion period (5.7 ± 7.5%, p = 0.001). Myocardial infarct size measurements revealed a significant decrease in cell death in the myocardium region of the RIPC group (41.44 ± 6.42%, p = 0.001) compared with the control group (60.05 ± 10.91%). As a result, we showed that the cardioprotective effect of RIPC could be attributed to endogenous NO production during the ischemic period, which subsequently promoted reoxygenation in post-ischemic myocardia during early reperfusion. Our results suggest that the promotion of endogenous formation during an ischemic episode might be helpful as a therapeutic strategy for protecting the myocardium from IR injury. Additionally, our NO and O2 perm-selective microsensors could be utilized to evaluate the effect of drug or treatment. 相似文献