肝细胞生长因子对主要器官/组织损伤的修复作用

肝细胞生长因子(HGF)是一种多功能的生长因子,它参与多种细胞的增殖、迁移和形态发生。HGF对多种成熟的器官／组织有营养修复作用,促进肝、肾、肺等损伤器官的再生,同时也是神经系统新的营养因子之一。本综合近年来有关献对HGF在主要器官或组织损伤中的修复作用作一概括性介绍。     

松香改性的研究进展

本文综述了近年来松香改性的研究进展情况,对其进行了分类阐述,即基于羧基的改性、基于双键的改性、基于羧基和双键的改性以及其它方面的改性,并展望了此领域的发展趋势和前景。     

沙柳灌丛植株形态与气流结构野外观测研究

通过野外观测,研究了毛乌素沙地南缘平沙地人工栽种单行沙柳灌丛的植株形态与气流结构.结果表明,沙柳灌能降低迎风侧和背风侧的近地面风速,使沙粒在植株下部沉积.积沙体积(V₂)与植株体积(V₁)相关性较高(R=0.696).单行沙柳灌丛在4 m高处风速为6 m·s^-1时的气流结构特征为:迎风侧3H处风速已降低,2 H处风速又得到加强,之后在背风侧迅速降低,1 H处达到最低值,然后逐渐恢复到旷野风速.防护距离约为17H',有效防护距离约为13 H'.沙柳灌丛对植株高度以上高度处风速影响较小.     

非小细胞肺癌的治疗方案及影响预后的重要因素

目的:回顾分析各种非小细胞肺癌(non-small cell lung cancer,NSCLC)的治疗方案及影响其治疗预后的因素,为合理制定个体化的综合治疗方案提供参考。方法:回顾分析近年来NSCLC治疗的研究报道,分析如病理分期、实验室检查结果(VEGF、WBC、Hg等)影响治疗预后的因素,建议相应的治疗对策。结果:1.Ⅰ期、Ⅱ期及部分Ⅲa期NSCLC的患者治疗措施首先以手术治疗为主,同步放化疗比单纯放、化疗及序贯放化疗更能有效改善晚期NSCLC的预后;2.个体相关因素、肿瘤相关因素和治疗相关因素影响NSCLC治疗预后。结论:同步放化疗在晚期NSCLC的治疗中有重要作用,肿瘤的病理分期、血浆VEGF浓度是影响NSCLC预后的独立因素。     

北京市11种园林植物滞留大气颗粒物能力研究

测定了北京市11种园林植物叶面颗粒物附着密度,利用环境扫描电镜观察比较了各测试树种叶表面微形态,测量统计了滞留颗粒物的粒径分布.结果表明,植物主要通过叶片上表面滞留大气颗粒物,上表面滞留的大气颗粒物数量约为下表面的5倍;叶片上表面滞留大气颗粒物能力由高到低的微形态结构依次是沟槽>叶脉＋小室 >小室>条状突起,并且结构越密集、深浅差别越大,越有利于滞留大气颗粒物;测试树种叶片上、下表面PM_2.5和PM₁₀平均百分含量分别为66.7％和98.3％与 43.4％和92.9％.     

Myostatin基因打靶载体的构建及猪胎儿成纤维细胞Myostatin基因的敲除

目的:用缺口修复等技术构建Myostatin(肌肉生长抑制素,MSTN)基因打靶载体,并对大白猪胎儿成纤维体细胞进行转染,获得基因敲除细胞。方法与结果:首先构建用于MSTN基因同源长臂(LA)的抓捕载体,然后在大肠杆菌内利用Red同源重组系统介导的缺口修复,从含大白猪MSTN基因座的细菌人工染色体上亚克隆9.9 kb的LA到抓捕载体上,经过部分序列测定,同源性为100%;通过PCR获得1.4 kb的同源短臂(SA);将LA和SA连入载体pLOXP,构建含有neo和tk正负筛选标记基因的MSTN基因打靶载体pLOXP-MSTN-KO;将线性化的pLOXP-MSTN-KO通过电转染整合到大白猪胎儿成纤维细胞基因组中,利用G418和丙氧鸟苷进行药物筛选,获得抗性细胞克隆890个,通过PCR和DNA测序鉴定获得基因敲除的细胞克隆4个。结论:构建了有效的MSTN基因打靶载体,通过转染获得基因敲除细胞,为利用体细胞核移植制备MSTN基因敲除猪奠定了基础。     

浑善达克沙地沙地榆种子雨的扩散规律

于2010年采用定点连续观测的方法,研究了浑善达克沙地不同树龄(23年生、40年生、56年生)沙地榆孤立木种子雨的数量、组成及散布过程,分析沙地榆种子雨的扩散规律及其与外界环境干扰因子的关系。结果表明:(1)孤立木种子雨的总量随其年龄增长而增加,其中56年生孤立木>40年生孤立木>23年生孤立木,其种子雨的总量分别为(7744±16.26)粒/m2、(5236±18.87)粒/m2、(2456±12.67)粒/m2;(2)40年生孤立木的种子质量较好,成熟种子的比例最高,未成熟、空粒和虫害种子的比例较低,56年生孤立木次之,23年生孤立木质量最差,56年生沙地榆和40年生沙地榆是自然更新种子的主要来源;(3)榆树种子于当年5月下旬开始成熟并于6月初开始脱落,6月中旬达到降落高峰期,落种持续到6月下旬结束,落种期持续近1个月;(4)种子雨的前扩散过程中种子集中降落在主风向的下风向50 m和树冠周围20 m的范围内;(5)在种子的后扩散过程中,种子沿下风向继续运动,散落在下风向50 m范围或更远处,后扩散对前扩散表现为"削锋"作用。     

冷却肉糜辐照脂肪氧化影响因素与抑制效果研究

研究了低剂量辐照、抗氧化剂、包装条件以及贮藏时间等影响辐照冷却肉脂肪氧化的主要因素和抑制效果.结果表明,对冷却猪肉的辐照处理会加剧其脂肪的氧化,真空包装或无氧包装可以明显的降低贮藏期间辐照冷却肉的脂肪氧化.辐照处理前在肉糜中添加抗氧化剂并采用真空包装时, 肉糜可以贮藏2周以上而不产生脂肪氧化.比较几种主要的抗氧化剂的效果表明,茶多酚在抑制辐照冷却肉糜脂肪氧化方面效果最好.     

Temperament in Rhesus,Long‐Tailed,and Pigtailed Macaques Varies by Species and Sex

Temperament differs among individuals both within and between species. Evidence suggests that differences in temperament of group members may parallel differences in social behavior among groups or between species. Here, we compared temperament between three closely related species of monkey—rhesus (Macaca mulatta), long‐tailed (M. fascicularis), and pigtailed (M. nemestrina) macaques—using cage‐front behavioral observations of individually housed monkeys at a National Primate Research Center. Frequencies of 12 behaviors in 899 subjects were analyzed using a principal components analysis to identify temperament components. The analysis identified four components, which we interpreted as Sociability toward humans, Cautiousness, Aggressiveness, and Fearfulness. Species and sexes differed in their average scores on these components, even after controlling for differences in age and early‐life experiences. Our results suggest that rhesus macaques are especially aggressive and unsociable toward humans, long‐tailed macaques are more cautious and fearful, and pigtailed macaques are more sociable toward humans and less aggressive than the other species. Pigtailed males were notably more sociable than any other group. The differences observed are consistent with reported variation in these species’ social behaviors, as rhesus macaques generally engage in more social aggression and pigtailed macaques engage in more male–male affiliative behaviors. Differences in predation risks are among the socioecological factors that might make these species‐typical behaviors adaptive. Our results suggest that adaptive species‐level social differences may be encoded in individual‐level temperaments, which are manifested even outside of a social context. Am. J. Primatol. 75:303‐313, 2013. © 2012 Wiley Periodicals, Inc.     

Differences in specificity and catalytic efficiency between allozymes of esterase-4 from Drosophila mojavensis

A more than 10-fold difference in the specificity and catalytic efficiency for 1-naphthyl esters was measured between two allozymes of esterase-4 from Drosophila mojavensis. This difference is mainly caused by a difference in the affinity for the 1-naphthyl esters. The amino acid compositions of the allozymes are not significantly different, which means that the difference in primary structure is small. Small differences in primary structure generally do not result in such a large increase in catalytic efficiency and such a large shift in substrate specificity as was found in the present study.