Reaction mechanism of surfactant‐sensitized chemiluminescence of bis(2,4,6‐trichlorophyenyl) oxalate and hydrogen peroxide induced by gold nanoparticles

The chemiluminescence (CL) of bis(2,4,6‐trichlorophyenyl) oxalate with hydrogen peroxide in the present of cationic surfactant and gold nanoparticles was studied. The CL emission was obviously enhanced in the presence of surfactant at a suitable concentration, with a synergetic catalysis effect exhibited. Different sizes of gold nanoparticles (15 and 50 nm) showed different effects on CL intensity. Mechanisms of the CL reaction and sensitization effect are discussed. Copyright © 2008 John Wiley & Sons, Ltd.     

Determination of immunoreactive endothelin in medium from cultured endothelial cells and human plasma

We have developed a sensitive and selective radioimmunoassay for porcine/human endothelin (ET1). The assay has a detection limit of 0.62 pg/tube and exhibits no cross-reactivity to atrial natriuretic peptide, arginine vasopressin, or angiotensin II. Procedures were developed for extraction of endothelin from human plasma samples and samples of buffer from endothelial cell incubations using C18 Sep-Pak extraction cartridges. The mean recovery following extraction was approximately 80%. Both bovine and porcine aortic endothelial cells were found to produce immunoreactive endothelin (IR-ET) with porcine cells producing 4.7 +/- 1.1 ng of IR-ET/mg cell protein after 6 hours. Human plasma samples were extracted, assayed and found to contain a mean concentration of 2.0 +/- 0.4 pg/ml of IR-ET.     

麦田冠层气孔导度的分层研究

小麦灌浆期和乳熟期冠层各层叶片上、下表面的气孔导度之间呈正相关关系;冠层不同层的叶片气孔导度从早到傍晚有平行变化的趋势,数值上存在较大的差异,一般从冠层上到下递减。经分析,这主要与冠层叶片接受的光强自上而下递减有关,且这时所对应的叶片水势自冠层上到下递增的幅度大。测算结果表明,冠层气孔导度白天亦呈明显的日变化,灌浆期的值大于乳熟期的值。     

中国紫堇属大叶紫堇组的分类与分布

本文叙述大叶紫堇组在紫堇属(Corydalis)中的系统位置以及其分布区的原始性,同时记载了隶属于5个系的23种9变种和1变型,其中有4个新系,7个新种和7个新变种。     

类脂过氧化对竹红菌甲素引起膜蛋白光敏交联的影响

本文研究了丙二醛与红细胞膜温育后所形成的交联。当丙二醛浓度在5×10~-4mol/L以上时,膜蛋白发生交联,并且在460nm处有荧光特征峰出现。而甲素光敏所致膜蛋白的交联,在460nm处没有荧光峰,光敏所产生的内源丙二醛量很少,不足以引起红细胞膜反应形成交联。我们还研究了BHT和Vit E两种抗氧化剂对甲素光敏作用的影响。BHT能抑制类脂过氧化,不能抑制膜蛋白巯基的变化和膜蛋白的交联。而Vit E仅不能抑制膜蛋白的交联。以上结果均说明甲素光敏所致膜类脂过氧化是不参与膜蛋白交联的。     

油菜饼的黄酮成分研究

从油茶饼正丁醇提取物中分离到两个黄酮甙,经UV、~1H NMR、~(13)C NMR、EI-MS、FAB-MS等仪器分析,鉴定为山奈酚-3-O-葡萄吡喃糖基(6→1)鼠李吡喃糖甙(1)和山奈酚-3-O-葡萄吡喃糖基-[(2→1)葡萄吡喃糖基](6→1)鼠李吡喃糖甙(2)。正丁醇提取物以酸水解亦分离到山奈酚(4)。油茶饼正丁醇提取物中还分离到蔗糖,得率达2.3％。     

光对尾穗苋幼苗内苋红素合成的诱导

不同苗龄的尾穗苋黄化苗对10 min,15Wm~(-2)白光的反应能力不同。光诱导的苋红素合成始于播种后第 20h,至50h合成能力最大,82h以后幼苗对短时光照的反应能力趋于消失。苋红素合成的滞后期为3h,光处理后18h色素积累达到高峰。光调节苋红素合成符合红光—远红光可逆诱导反应等两个基本模式,确证光敏色素参与调控苋红素合成.