Activation of proteinkinase ERK mediates induction of macrophage MMP-12 by OxLDL

The present study was undertaken to investigate the effect of oxidized low density lipoprotein (oxLDL) on the expression of maerophage matrix metalloproteinase-12 (MMP-12), and the possible mechanisms. Activation of extracellular signal-regulated kinase 1/2 (ERK1/2) was detected by Western blot analysis.Enzymatic activity of MMP-12 was determined by β-casein zymography. RT-PCR analysis was used to measure the mRNA expression level of MMP-12. OxLDL-stimulated macrophages produced increased casein-degrading activities and oxLDL also significantly increased the mRNA level of MMP-12 in a dose-dependent manner.OxLDL stimulated the phosphorylation of ERK1/2 in macrophages. The use of the specific inhibitor indicated that the ERK1/2 signaling pathway was required for the induction of MMP-12.These data demonstrated that oxLDL induced MMP-12 expression in macrophages through an ERK1/2-dependent pathway.     

Science Letters：Synergetic effects for p-nitrophenol abatement using a combined activated carbon adsorption-electrooxidation process

A novel fluidized electrochemical reactor that integrated advanced electrochemical oxidation with activated carbon (AC) fluidization in a single cell was developed to model pollutant p-nitrophenol (PNP) abatement. AC fluidization could enhance COD removal by 22%-30%. In such a combined process, synergetic effects on PNP and COD removal was found, with their removal rate being enhanced by 137.8% and 97.8%, respectively. AC could be electrochemically regenerated and reused, indicating the combined process would be promising for treatment of biorefractory organic pollutants.     

ISA-YMG粗铅冶炼新工艺

评述了铅提取技术的历史及现代铅提取技术的特点;针对我国目前粗铅冶炼现状,结合对高铅渣冶炼的多年研究,提出一种高效、节能、清洁的ISA-YMG粗铅冶炼新工艺,并提供了YMG还原熔炼工业试验结果。     

PBG光子晶体光纤中空气导光条件的研究

应用平面波法分析了带隙效应导引光子晶体光纤(Photonicbandgapguidingfibers,PBG PCFs)中实现空气通道导光必须满足的条件,计算机仿真了蜂窝和三角形两种不同结构的PBG PCFs的空气导光性能。计算结果表明,要实现空气导光,空气孔直径与周期的比值d/Λ必须大于某一特定值:对于蜂窝结构该比值为0.84,而对于三角形结构该比值为0.59;在特定的d/Λ下,空气导光的波长范围随Λ可变。     

克拉2气田石油地质特征

克拉2气田位于库车拗陷克拉苏构造带中段, 是双重构造中呈串珠状分布的一系列褶皱中的一个局部构造. 含气层系以下白垩统巴什基奇克组砂岩为主, 其次为下第三系库姆格列木群白云岩段和砂砾岩段及下白垩统巴西盖组砂岩. 天然气中甲烷含量大于97%, 属于干气, 气源为侏罗系煤系地层. 克拉2号构造圈闭形成于西域期, 成藏期晚. 下第三系厚层膏盐区域盖层形成的良好封盖条件及其成藏期晚是克拉2大气田得以很好保存的根本原因. 克拉2气田的异常高压是由于西域期来自北部的强烈构造挤压作用而形成的.     

二价铜离子对牛正常朊蛋白二级结构的影响

研究了二价铜离子对牛朊蛋白的二级结构的影响.牛朊蛋白(BoPrPc)的小分子(BoPrPcS)和大分子(BoPrPcL)经初步纯化后,在含Cu2+的碱性溶液中氧化,用反相柱进行氧化态和还原态的BoPrPcL和BoPrPcS的分离.质谱分析证明氧化态的Bo-prPcL和BoPrPcS分子质量分别为24.064,15.819ku.用远紫外圆二色谱(Far-UVCD)分析显示,BoPrPcS在208和222m处出现两个负峰,为典型的α-螺旋型结构;而Bo-PrPcL在222nm处负峰减小.与未经氧化的BoPrPcL的质谱和CD结果比较后发现,氧化后的BoPrPcL在八肽重复区结合了6个Cu2+,其β-折叠含量明显增加.而Cu2+对BoPrPcS二级结构基本无影响.BoPrPcL结合Cu2+的特性及其二级结构的相应变化可能与细胞内抗Cu2+毒性与氧化压力有关.     

热带西太平洋和东印度洋对ENSO发展的影响

分析了从1955～1998年44a热带西太平洋次表层海温距平资料,指出在这一期间共发生了11次E1 Nino事件,这些事件的初始海温正距平无一例外地都在 "暖池"次表层160 m附近生成,发展到一定强度,到西太平洋出现异常的持续西风距平后,暖的海温距平沿着气候的温跃层向东向海表传播,经过1 a左右的时间,传播到赤道东太平洋海表的E1 Nino 3或1、2海域形成通常认为的El Nino事件.进一步分析1960～1999年的850 hPa风场指出,在热带西太平洋西风距平爆发前,赤道东印度洋已经有距平西风持续维持了2 a左右(西南季风),然后距平西风快速地向东发展产生热带西太平洋的距平西风,或真正的强西风,致使西太平洋出现E1 Nino爆发不可缺少的条件之一,在这40 a中,这一过程对所有的El Nino事件无一例外.同样的分析方法也用到这44 a中的La Nina事件,冷的海温距平也都首先在"暖池"的次表层形成,然后沿着温跃层向东向表层传播,在热带西太平洋出现东风前,印度洋也早已是持续的东风.     

挑战水污染

据世界卫生组织报道,人类80％的疾病与水有关,并将不洁饮水列为人类健康的十大威胁之一     

Pt羰基簇合物途径制备的Pt/C催化剂对甲醇的电催化氧化

通过Pt羰基簇合物在N2气氛下于150℃热分解制得了无定形的碳载纳米Pt催化剂。发现甲醇在这种催化剂上氧化的起始电位和峰电位均比在传统的液相还原法制得的Pt／C催化剂上发生了,负移,峰电流也有明显的增加,且稳定性好。表明通过Pt羰基簇合物热分解制备Pt／C催化剂是一种较好的制备甲醇氧化电催化剂的方法。     

Involvement of nitric oxide in the signal transduction of salicylic acid regulating stomatal movement

The effects and the relationship between sali-cylic acid(SA)and nitric oxide(NO) on Vicia faba L.stomatal movement were studied.The results here showed that exogenous SA and NO induced stomatal closure,100μmol/L SA induced a rapid and striking NO increase in the cytosol of guard cells.This phenomenon was largely prevented by 2000μmol/L 2-phenyl-4,4,5,5-tetramethylimidazoline-l-oxyl-3-oxide(PTIO),a specific NO scavenger,and 25μmol/L N^G-nitro-L-Arg-methyl eater (L-NAME),an inhibitor of NO synthase(NOS) in mammalian cells that also inhibits plant NOS.In addition,SA-induced stomatal closure was largely prevented by PTIO and L-NAME.These results provide evidence that guard cells generate NO in response to SA via NOS-like activity,and that such NO production is required for full stomatal closure in response to SA.H-(1,2,4)-oxadiazole-[4,3-α]quinoxalin-l-one(ODQ),an inhibitor of guanylate cyclase,and nicotinamide,an antagonist of cADPR production,inhibited the effects of SA-and NO-induced stomatal closure.It suggests that both cGMP and cADPR might mediate the signal transduction of SA and NO-induced stomatal closure.