土壤和沉积物中1,2,4-三氯苯的超声波提取

以土壤和沉积物中的1,2,4-三氯苯为研究对象,应用超声波提取并以气相色谱进行定量分析。研究结果表明：在一定的超声波处理条件下,1,2,4-三氯苯较为稳定且降解比率很小;最适宜的超声波提取条件为：超声波功率20W、提取温度35℃、提取时间60min、提取剂为石油醚-丙酮混合溶剂(体积比1：1);三种不同提取方法(索氏、振荡和超声波)相比较以超声波提取法最优;该方法的平均回收率为92．18％、变异系数0．82%、检测限0．000μg／g,可满足土壤中微量有机物定量分析要求。     

Emodin inhibits tumor cell migration through suppression of the phosphatidylinositol 3-kinase-Cdc42/Rac1 pathway

Enhanced cell migration is one of the underlying mechanisms in cancer invasion and metastasis. Therefore, inhibition of cell migration is considered to be an effective strategy for prevention of cancer metastasis. We found that emodin (3-methyl-1,6,8-trihydroxyanthraquinone), an active component from the rhizome of Rheum palmatum, significantly inhibited epidermal growth factor (EGF)- induced migration in various human cancer cell lines. In the search for the underlying molecular mechanisms, we demonstrated that phosphatidylinositol 3-kinase (PI3K) serves as the molecular target for emodin. In addition, emodin markedly suppressed EGF-induced activation of Cdc42 and Rac1 and the corresponding cytoskeleton changes. Moreover, emodin, but not LY294002, was able to block cell migration in cells transfected with constitutively active (CA)-Cdc42 and CA-Rac1 by interference with the formation of Cdc42/Rac1 and the p21-activated kinase complex. Taken together, data from this study suggest that emodin inhibits human cancer cell migration by suppressing the PI3K-Cdc42/Rac1 signaling pathway.Received 7 February 2005; received after revision 11 March 2005; accepted 18 March 2005     

A novel pattern of fast calcium oscillations points to calcium and electrical activity cross-talk in rat chromaffin cells

Slow oscillations of cytosolic calcium ion concentration – – typically originate from release by intracellular stores, but in some cell types can be triggered and sustained by Ca²⁺ influx as well. In this study we simultaneously monitored changes in and in the electrical activity of the cell membrane by combining indo-1 and patch-clamp measurements in single rat chromaffin cells. By this approach we observed a novel type of spontaneous oscillations, much faster than those previously described in these cells. These oscillations are triggered and sustained by complex electrical activity (slow action potentials and spike bursts), require Ca²⁺ influx and do not involve release from intracellular stores. The possible physiological implications of this new pathway of intracellular signalling are discussed.Received 30 July 2004; received after revision 14 October 2004; accepted 1 November 2004     

一个带羟基的C_（60）吡咯烷衍生物的合成与表征

氮气流保护下，Ｃ６０与聚甲醇和苏氨酸在干燥的甲苯中反应生成一个带羟基的Ｃ６０。吡咯烷衍生物。标题化合物用ＦＤ－ＭＳ，ＦＴ－ＩＲ，ＵＶ－ＶＩＳ和１Ｈ－ＮＭＲ进行了表征。     

Maternal influences on cardiovascular pathophysiology

Elevated blood pressure (BP) is of special clinical significance because of its association with pathophysiologies such as heart disease, renal failure, and stroke. We described the development of a protocol for use with hypertensive rats in which prepubertal exposure to a high salt (8% NaCl) diet results in a pathophysiological syndrome including rapid increase in BP, failure to maintain normal weight gain, renal damage, cerebrovascular lesions, and early mortality. These phenomena are described for the inbred spontaneously hypertensive rat (SHR), and for reciprocal F₁ hybrids of a cross between SHR and the Dahl salt-sensitive (SS/Jr) inbred strain. The study with reciprocal F₁s revealed striking effects of maternal environment on pathophysiological response to a high salt diet. F₁s nurtured by SHR mothers weighed less at 35 days of age, and after exposure to the high salt diet suffered more rapid BP increases, greater incidence of stroke, body weight loss, and mortality, than F₁s nurtured by SS/Jr dams. These results suggest that maternal mediation of the nutritional status of the animal may play an important role in determining susceptibility to elevated BP and subsequent pathophysiology associated with exposure to a high salt diet. The implication of these findings for human hypertension is briefly discussed.     

关于分离性的一点注记

本文引入CS分离性,讨论了它与T_0、T、T_1和正则空间的关系,最后给出CS空间几个重要性质.     

2＋1维U（1）格点规范理论的相图

应用单元格试探作用量变分法研究2 1维U(1)格点规范场的相图。解析地计算出序参量——平均元格能量,与MC方法所得结果符合很好。证实2 1维U(1)格点规范理论是禁闭的。消除了以往文献中用单链试探作用量变分法出现的不正确的一级相变点,还可以很方便地计算到比MC方法的β更大的深度弱耦合区。     

ZnL2Cl4的晶体结构、荧光性质及标准摩尔反应焓变

在无水乙醇中,用1-氨基-4-甲基哌嗪缩水杨醛（L）与ZnCl2合成了希夫碱配合物ZnL2Cl4,对其进行了元素分析及固体荧光袁征,并用Xn射线衍射测定了其单晶结构．结果表明,Zn^2＋与4个Cl-形成配位键,并与配体以分子间氢键形式联接成三维超分子结构．晶体属于单斜晶系,空间群为C2／c,晶胞参数α=12．0757（12）nm,b-8．9859（8）nm,c-27．435（3）nm,β=98．9450（10）°,V=2940．8（5）nm3,Z=4,F（000）=1344,Dc=1．463g／cm3,μ=1．231mm^-1．该L及ZnL2Ck均有较好的发光性质,发出蓝色荧光．298．15K下,ZnCl2和L在无水乙醇中的溶解焓及配合物液相反应生成焓分别为（7．150±0．022）,（-32．587±0．307）,（3．745±0．035）kJ／tool,热化学循环求得固相标准摩尔反应焓变为（-54．279±0．671）kJ／m01．     

Smurf2单克隆抗体的制备与鉴定

Smad泛素调节因子家族的两个E3泛素连接酶成员Smurf1和Smurf2 (Smad ubiquitin regulatory factor 1 and 2)具有至少80％的同源性.为了更好地研究它们的功能,需要获得一个能区分Smurf1和Smurf2的单克隆抗体.选取Smurf2与Smurf1蛋白序列中仅有的非同源区域序列作为抗原免疫Bal b/C小鼠,成功制备若干株能稳定分泌抗Smurf2抗体的杂交瘤细胞株.对所获得的单克隆抗体的效价和特异性等进行一系列检测,结果表明该抗体能特异性地识别过表达及细胞内源Smurf2蛋白.此外该抗体能被应用于Western blot和免疫荧光实验,从而为深入研究Smurf2的细胞生物学功能提供了良好的实验基础.     

中国工业水环境COD、NH_4-N排放变化影响因素研究

为剖析工业污染排放变化的驱动机制,选取工业废水排放中2种典型污染物COD、NH4-N,将其排放变化分解为规模、结构、技术3种效应,并进一步将技术效应分解为清洁生产和污染治理2种效应,应用LMDI1方法求得各种效应值.结果表明:2001—2009年间,工业COD排放年均变化率为-2.99%,对应几种效应值分别为14.64%、-1.39%、-16.24%、-10.71%和-5.53%;NH4-N年平均变化率为-4.03%,几种效应值分别为16.18%、-2.88%、-17.33%、-9.48%和-7.85%.规模效应是造成COD、NH4-N排放增加的主要原因,分别占总效应值的45%和44%.技术效应是COD、NH4-N排放量降低的关键因素,分别占总效应值的50%和48%.清洁生产效应占技术效应的比例分别为60%和55%,污染治理效应相对较小.结构效应对COD、NH4-N减少排放具有正贡献,但总体影响程度较小.在对主要工业行业排污特点分析基础上,从规模、结构和技术3方面提出了行业调整和发展的方向.