Central dopaminergic neurotransmission plays an important role in thermoregulation and performance during endurance exercise

Dopamine (DA) has been widely investigated for its potential role in determining exercise performance. It was originally thought that DA's ergogenic effect was by mediating psychological responses. Recently, some studies have also suggested that DA may regulate physiological responses, such as thermoregulation. Hyperthermia has been demonstrated as an important limiting factor during endurance exercise. DA is prominent in the thermoregulatory centre, and changes in DA concentration have been shown to affect core temperature regulation during exercise. Some studies have proposed that DA or DA/noradrenaline (NA) reuptake inhibitors can improve exercise performance, despite hyperthermia during exercise in the heat. DA/NA reuptake inhibitors also increase catecholamine release in the thermoregulatory centre. Intracerebroventricularly injected DA has been shown to improve exercise performance through inhibiting hyperthermia-induced fatigue, even at normal ambient temperatures. Further, caffeine has been reported to increase DA release in the thermoregulatory centre and improves endurance exercise performance despite increased core body temperature. Taken together, DA has been shown to have ergogenic effects and increase heat storage and hyperthermia tolerance. The mechanisms underlying these effects seem to involve limiting/overriding the inhibitory signals from the central nervous system that result in cessation of exercise due to hyperthermia.     

论影视对白翻译的等值策略及其补充

影视对白翻译受到了越来越广泛的关注,我们可以在一定程度上运用等值原则来分析这类翻译。然而,鉴于等值原则的不足,本文认为出于影视对白的特殊性,应该有更多的翻译理论,如解构翻译理论和目的论,被运用到影视对白的翻译研究中,进而充实影视翻译的理论视野。     

CCR5稳定表达的CHO细胞的构建

在人体内,CCR5与许多免疫疾病有关,CCR5有望成为众多药物的作用靶点。将ccr5基因与真核表达载体pBBS242构建成重组质粒pBBS242-ccr5,转染CHO细胞,并经潮霉素B筛选。流式细胞仪检测结果表明CCR5在CHO细胞得到了稳定表达。     

Study on the effect of doxorubicin on expressions of genes encoding myocardial sarcoplasmic reticulum Ca<Superscript>2+</Superscript> transport proteins and the effect of taurine on myocardial protection in rabbits

To investigate the effect of doxorubicin(DOX) on gene expression of the myocardial sarcoplasmic reticulum (SR) Ca²⁺ transport proteins and the mechanism of taurine(Tau) protecting cardiac muscle cells, 9 rabbits were injected with DOX, 8 rabbits with DOX and Tau, and 9 rabbits with normal saline. Cardiac function, concentration of calcium in cardiomycocytes (Myo [Ca²⁺] _i ), activity of SR Ca²⁺-ATPase (SERCA2a), level of SERCA2a mRNA and Ca²⁺ released channels (RYR2) mRNA were detected. The left ventricle tissues were observed by electron microscopy. The results showed that cardiac index, left ventricular systolic pressure, activity of SR Ca²⁺-ATPase and level of SERCA2a mRNA decreased, while Myo[Ca²⁺] _i increased in DOX-treated rabbits. DOX could not affect the level of RYR2 mRNA. Tau intervention could alleviate the increase of left ventricular diastolic pressure, Myo[Ca²⁺] _i and the decrease of SERCA2a mRNA induced by doxorubicin. The results suggested that downregulation of SERCA2a gene expression was an important mechanism of DOX-induced cardiomyopathy and that Tau could partially improve the heart function by reducing calcium overload and alleviating downregulation of SERCA2a mRNA.     

植物细胞跨膜信号转导中G蛋白的研究概述

G蛋白在物种进化过程中具有高度保守性，不同的G蛋白有不同的基因编码．检测植物G蛋白多采用生化检测法和分子生物学检测法．植物G蛋白在光信号转导、激素信号转导和病原信号转导等方面有重要调控作用．     

对传播学中使用与满足理论的再探索

以现代传播学的发展为背景，以受众谱系中的发展脉络为史线，使用与满足理论具有的地位及意义是重大的：该理论使研究视角从以传播者为中心转向了以受众为中心；从功能主义的视野出发，该理论体现了媒介在微观与个人层面上的功能，以及它后期又如何试图从功能主义的框架中挣脱出来；该理论本身所具有的内在缺陷表现为其批判精神的缺席。     

Ursolic acid inhibits proliferation and induces apoptosis of HT-29 colon cancer cells by inhibiting the EGFR/MAPK pathway

rectal cancer.     

尾加压素Ⅱ受体拮抗剂对阿霉素肾病大鼠中尾加压素Ⅱ影响的对比研究

目的:观测尾加压素Ⅱ受体拮抗剂palosuran对阿霉素肾病大鼠尿中尾加压素Ⅱ(UrotensinⅡ;UⅡ)的影响,从而探究palosuran对微小病变肾病综合征(minimal change ne-phropathy syndrome;MCNS)的作用。方法:采用雄性Wistar大鼠80只,体重100±20g。随机选择其中10只做为健康组,其余70只大鼠尾静脉一次性注射阿霉素5mg/kg建立动物模型。注射后第7天检测大鼠24小时尿蛋白定量,若大鼠尿蛋白>30mg/24h者为MCNS模型成功,不合格者予以剔除。将合格的大鼠,随机分成2组,一组设为微小病变型肾病模型组,另一组在微小病变型肾病模型的基础上采用palosuran混入饲料中给药方法喂养,设为干预组。在实验第14、21、28天检测各组大鼠采用放射免疫法检测各组大鼠尿UⅡ的水平。结果:健康组大鼠尿UⅡ第14、21、28天检测值分别是1.46±0.18 ng/mL,1.52±0.12 ng/mL,1.54±0.43 ng/mL;模型组分别是2.49±0.11 ng/mL,4.48±0.19 ng/mL,6.56±0.27 ng/mL;干预组分别是1.95±0.1ng/mL,3.31±0.15 ng/mL,2.58±0.21 ng/mL。随着时间的延续,模型组大鼠尿UⅡ进行性升高(P<0.05),而palosuran对肾病大鼠尿UⅡ水平有明显影响,差异有显著统计意义(P<0.05)。结论:palosuran可能通过抑制UⅡ的作用而对微小病变肾病大鼠肾损害产生保护作用。     

高效液相色谱法分析塑料玩具中的环境雌激素双酚A

双酚A是常用的塑料添加剂,也是常见的环境雌激素,塑料玩具中的双酚A对儿童的健康具有潜在的风险.建立了5种市售儿童玩具中双酚A的溶剂提取和高效液相色谱分析方法,共有2种塑料玩具检出双酚A.对5种塑料进行加标回收试验,回收率在93.13%～112.35%之间.该分析方法快速、简便、可靠,可用于塑料玩具中双酚A的分析测定.     

Effects of insulin-like growth factor-1 on the properties of mesenchymal stem cells in vitro

Objective  

To explore the effects of insulin-like growth factor-1 (IGF-1) on migration, proliferation and differentiation of mesenchymal stem cells (MSCs).