Temperature rising elution fractionation of a random ethene/styrene copolymer

A random ethene/styrene copolymer containing 13.8 mol-% styrene was prepared with the Ziegler-Natta catalyst system Me₂Si(Me₄Cp)(N-t-butyl)TiCl₂/methylaluminoxane and characterized by means of preparative temperature rising elution fractionation (TREF) combined with size exclusion chromatography, NMR, differential scanning calorimetry and wide-angle X-ray scattering analyses of the copolymer fractions. Efforts are made to describe the distribution of the styrene content of the copolymers using the Stockmayer-Tacx distribution function. Both, comonomer distribution and molar mass distribution strongly support the presence of a single type of catalytically active center.     

GSK-3及P70S6K在胰岛素抵抗大鼠肌肉中的表达及意义

目的:观察饮食诱导的胰岛素抵抗(IR)大鼠骨骼肌中糖原合成酶-3(GSK-3)及核糖体S6蛋白激酶(P70S6K)的表达及变化情况,并探讨GSK-3和P70S6K在IR发生中的作用及意义.方法:将40只4周龄Wistar大鼠随机分为正常对照组、高糖组、高脂组、高脂高糖饲养组,喂养8周后用高胰岛素-正葡萄糖钳夹技术(钳夹试验)对大鼠进行胰岛素敏感性的评估,采用Western blot法检测各组大鼠骨骼肌中GSK-3及P70S6K的含量,同时测定各组大鼠的附睾脂肪垫重量、血糖(BG)、胰岛素(INS)、甘油三酯(TG)、胆固醇(TC)及游离脂肪酸(FFA)水平、超敏C反应蛋白(hsCRP).结果:高脂高糖组、高脂组大鼠产生明显IR,体重增加(P＜0.01),以附睾脂肪垫的重量增加更为显著(P＜0.01),TG、TC及FFA水平、hsCRP增加(P＜0.01),GSK-3、P70S6K在IR大鼠肌肉中的表达明显升高.结论:高脂高糖饮食可诱导大鼠产生IR,IR大鼠的hsCRP、TG、TC及FFA水平明显增高,大鼠产生IR与炎症反应有关,GSK-3、P70S6K在IR大鼠中的表达明显升高,在胰岛素信号传导中起负相调节作用.     

Plasmids encoding foot-and-mouth disease virus VP1 epitopes elicited immune responses in mice and swine and protected swine against viral infection

VP1 is a capsid protein of foot-and-mouth disease virus (FMDV) and contains epitopes of the virus. Plasmids encoding two VP1 epitopes (amino acid residues 141-160 and 200-213) and a host-self immunoglobulin molecule were constructed to produce a new type of FMD DNA vaccine. Two plasmids, namely, pCEIM and pCEIS, containing mouse immunoglobulin (IgG) or swine IgG were subjected to immunogenicity testing in mice and swine, respectively. In mice administrated pCEIM in the abdomen using a genegun, both FMDV-specific T-cell proliferation and neutralizing antibodies were detected. In swine immunized with pCEIS at the back of the ear, immune responses were achieved after the second administration. Swine showed a T-cell proliferative response with a stimulation index (SI) of up to 8.1 and a neutralizing antibody response that was able to protect suckling mice from 10(2) LD(50) (lethal dose 50) FMDV challenge. To compare the immunogenicity of the DNA-based vaccine candidate, versus the protein-based vaccine candidates, a second group of swine was immunized with the protein F1-scIgG, which was encoded by the plasmid pCEIS. Injection with F1-scIgG elicited a T-cell proliferative response of SI < 1.7 and a neutralizing antibody response that protected suckling mice from up to 10(5) LD(50) FMDV challenge. In the challenge test, three of three swine immunized with pCEIS were fully protected from FMDV challenge.     

护理人员应付方式的相关因素分析

目的 探讨影响护理人员应付方式的相关因素。方法 采用应付方式问卷和艾森克个性问卷对303名护理人员进行评定。结果 护理人员的应付方式与个性心理特征相关性较大,与年龄和护龄不呈线性关系,与是否倒班和不同的科室无关。4－5年和6－8年护龄的护理人员在应用解决问题应付方式上,比其他护龄组明显减少。结论 应加强护理人员,尤其是工作4－8年的护理人员的应付方式的指导。     

脑梗死患者血浆神经肽Y、降钙素基因相关肽、神经降压素、胃动素动态变化及其临床意义

观察脑梗死(CI)患者神经肽Y(NPY)、神经降压素(NT)、胃动素(MTL)、降钙素基因 相关肽(CGRP)浓度变化及其临床意义。方法选择C162例,用放免法检测血浆NPY、NT、MTL与CGRP浓度。结果NPY、NT与MTL浓度显著高于对照组(P<0.0001);于发病后24h内显著升高,7d内达高峰,8～15d开始下降,15d后仍在较高水平。NPY浓度重型与大灶组显著高于轻型(P<0.05)与小灶组(P<0.01);发病积分≥6分组显著高于<6分组(P<0.05);高血压组显著高于正常血压组(P<0.05)。NT与MTL浓度重型组显著高于中(P<0.05)、轻型组(P<0.01);高血糖组显著高于正常血糖组(P<O.01)。CGRP浓度显著低于对照组(P<0.0001),发病24h内即显著降低,2～7d进一步降低,8～15d开始升高,15d后逐渐升至正常水平。重型与大灶组显著高于轻型(P<0.0001)、中型(P<0.01)与小灶组(P<0.01);伴发病积分≥6分组显著低于<6分组(P<0.05)。结论CI患者NPY、NT、MTL、CGRP浓度变化以7d内最显著,15d后逐渐恢复正常水平;四种浓度监测可作为判断CI患者病情严重程度、病灶大小及伴发病的实验室指标。     

热力学模型对石油低压汽液平衡计算的适用性

以Maxwell-Bonnel图拟合式、对比态Antoine方程及Pitzer-Riedel关联式分别求算饱和蒸汽压P^0,并用RoultK值（K＝P^0／P）,计算窄留分K值。根据实测的中原、孤岛和克拉玛依石油馏分低压K值,考察上述三式,结果表明：对比态Antoine式预测精度是最好的,其温度预测绝对平均偏差为7．0℃,K值预测平均相对偏差为15．6％,其他两模型偏差均较大。     

Clinical significance and assessment of cytokines in various stages of ulcerative colitis

Summary In order to study the clinical significance and change of interleukin (IL)-1β and IL-10 concentration in intestinal mucosal tissues in various stage of ulcerative colitis (UC), IL-1β and IL10 levels were measured by enzyme linked immunosorbent assays (ELISA). Our results showed that IL-β level caused by spontaneous secretion in the intestinal mucous tissues in active stage of ulcerative colitis was significantly higher than that in normal controls and in remission stage of ulcerative colitis (P <0. 01,P<0. 001). IL-10 level in various stage of UC was relatively lower in controls, but there was no significantly difference between the two groups. Our study suggested that higher IL-1β level in active might play an important role in pathogenesis of UC, and IL-10, as an anti-inflammatory cytokine, was low in active UC, suggesting that it may be a important factor contributing to the development of higher IL-1β level. This project was supported by the grant of the Scientific Research Fund of the Ministry of Health (No. 98-2-387).