蔓荆子黄素对小鼠单核巨噬细胞增殖和凋亡的影响

目的通过蔓荆子黄素对小鼠腹腔巨噬细胞活性及RAW264.7细胞增殖和凋亡作用的研究,探讨蔓荆子黄素对单核巨噬细胞的影响。方法分别用含有不同浓度蔓荆子黄素作用于小鼠腹腔巨噬细胞与小鼠单核巨噬细胞RAW264.7,于24、48及72 h后采用CCK-8检测细胞活性。使用AO/EB染色观察RAW264.7细胞凋亡变化;应用流式细胞仪检测RAW264.7细胞凋亡率。通过荧光探针DCFH-DA检测RAW264.7细胞活性氧水平,使用JC-1染色标记线粒体膜电位的变化。结果 CCK-8法检测结果显示,蔓荆子黄素对小鼠腹腔巨噬细胞的细胞活性及RAW264.7细胞的增殖都有抑制作用,呈剂量与时间依赖关系,尤其对具有增殖能力的RAW264.7细胞活性抑制作用更强。AO/EB染色结果显示,RAW264.7细胞经浓度为5及10μmol/L的蔓荆子黄素处理后,细胞表现为凋亡形态;流式细胞仪检测结果显示,蔓荆子黄素诱导RAW264.7细胞Sub-G1期代表凋亡细胞的百分比增加(P<0.05)。蔓荆子黄素作用于RAW264.7细胞后,细胞内活性氧水平提高;JC-1染色结果显示,蔓荆子黄素能使RAW264.7细胞的线粒体膜电位下降。结论蔓荆子黄素能够抑制小鼠腹腔巨噬细胞与小鼠单核巨噬细胞RAW264.7活性,尤其对具有增殖能力的RAW264.7细胞活性抑制作用更强,可以促进其凋亡,其作用机制与增加细胞内活性氧水平和降低线粒体膜电位有关。

Neuroprotective mechanism of Kai Xin San: upregulation of hippocampal insulin-degrading enzyme protein expression and acceleration of amyloid-beta degradation

Kai Xin San is a Chinese herbal formula composed of Radix Ginseng, Poria, Radix Polygalae and Acorus Tatarinowii Rhizome. It has been used in China for many years for treating amnesia. Kai Xin San ameliorates amyloid-β(Aβ)-induced cognitive dysfunction and is neuroprotective in vivo, but its precise mechanism remains unclear. Expression of insulin-degrading enzyme(IDE), which degrades Aβ, is strongly correlated with cognitive function. Here, we injected rats with exogenous Aβ42(200 μM, 5 μL) into the hippocampus and subsequently administered Kai Xin San(0.54 or 1.08 g/kg/d) intragastrically for 21 consecutive days. Hematoxylin-eosin and Nissl staining revealed that Kai Xin San protected neurons against Aβ-induced damage. Furthermore, enzyme-linked immunosorbent assay, western blot and polymerase chain reaction results showed that Kai Xin San decreased Aβ42 protein levels and increased expression of IDE protein, but not m RNA, in the hippocampus. Our findings reveal that Kai Xin San facilitates hippocampal Aβ degradation and increases IDE expression, which leads, at least in part, to the alleviation of hippocampal neuron injury in rats.

Mechanism of CO_(2) enhanced oil recovery in shale reservoirs

Combined with NMR,core experiment,slim-tube tests,nano-CT and oil composition analysis,the mechanism of CO(2) enhanced oil recovery had been studied.CO_(2) flooding under supercritical state could achieve higher oil recovery.In the process of crude oil displaced by supercritical CO2,the average oil recovery was 46.98% at low displacement pressures and 73.35% at high displacement pressures.The permeability of cores after CO2 flooding was only 28%-64% of those before flooding.As to the expelled oil,the contents of asphaltenes and non-hydrocarbons decreased,and saturated hydrocarbons of above C25 were absent in some samples,indicating that they had been retained in cores as demonstrated by CT and NMR experiments.In slim-tube tests,the heavy components of oil were expelled when the pressure increased to 30 MPa.There was a reasonable bottom hole pressure(BHP) below which the heavy components driven out from the far-well zone would deposit in the near-well zone,and when the pressure was too high,the nonhydrocarbon detention may cause block.The smaller throat and worse physical properties the porous media had,the higher displacement pressure would be required to achieve a good oil displacement efficiency.The increase in displacement pressure or time of interaction between oil and CO2 could effectively enhance oil recovery.

Stereodirecting Effects of 4-O-ortho-cyanobenzyl Ether on Chemical Glycosylation with Glucopyranosyl Donor

Here we report a systematic investigation on the stereodirecting effects of a 4-O-ortho-cyanobenzyl ether(oBCN)group with a glucopyranosyi donor.Experimental studies revealed that the glycosylation reactions using this donor generally show dual-stereoselectivities depending on the acceptor nucleophilicity,that is,glycosylation of weak nucleophile acceptors generally affordsα-glycosides specifically while glycosylation of strong nucleophile acceptors affords β-glycosides preferentially.

Sweet Strain Release:Donor-Acceptor Cyclopropane Mediated Glycosylation

Chemical glycosylation methodologies for the preparation of the bioactive oligosaccharides and glycoconjugates promise reliable access to these compounds as homogeneous materials with welldefined structures in sufficient amounts.Here we report a novel activation method of thio(seleno)glycosides employing donor-acceptor cyclopropane(DAC)agents and Sc(OTf)_(3).The Lewis acid catalyst converts DAC into a formal 1,3-zwitterionic species that in turn activates thioglycosides to furnish a glycosyl 1,4-zwitterionic intermediate,interconverting with reactive glycosyl oxocarbenium in the solution with reversible leaving-group dissociation.This activation method effectively promotes glycosylation reactions between both armed and disarmed thioglycosides and structurally diverse acceptors,affording oligosaccharides with satisfactory yields.The usefulness of our activation method has been demonstrated by the mechanism-inspired 2,4-dinitrobenzenesulfonyl(DNs)group directed S_(N)2-like glycosylation and the facile preparation of both linear and branched trisaccharides in one pot via controlled sequential activation of thioglycoside donors.

RFID unreliable data filtering by integrating adaptive sliding Window and Euclidean distance

Through improving the redundant data filtering of unreliable data filter for radio frequency identification(RFID) with sliding-window,a data filter which integrates self-adaptive sliding-window and Euclidean distance is proposed.The input data required being filtered have been shunt by considering a large number of redundant data existing in the unreliable data for RFID and the redundant data in RFID are the main filtering object with utilizing the filter based on Euclidean distance.The comparison between the results from the method proposed in this paper and previous research shows that it can improve the accuracy of the RFID for unreliable data filtering and largely reduce the redundant reading rate.