2种纤维素酶水解效果比较及酶蛋白组分分析

比较了自产纤维素酶和商品纤维素酶的水解效果,并采用超滤、层析、SDS-PAGE相结合的方法分析2种纤维素酶蛋白组分的差异。里氏木霉以纸浆为C源合成的自产纤维素酶的水解得率高于商品纤维素酶,自产纤维素酶水解48h的得率为66.24%,商品纤维素酶的得率为52.19%。自产纤维素酶中存在着Cel6A酶组分和XYNⅡ酶组分,而商品纤维素酶中没有检测到这2种酶组分。自产纤维素酶和商品纤维素酶的Cel1A酶组分和Cel7A酶组分间存在着分布和含量上的差异。自产纤维素酶在相对分子质量(2.5～3.5)×104范围内存在着几条蛋白条带,而商品纤维素酶则是在相对分子质量3.5×104附近存在着几条蛋白条带。     

富血小板纤维蛋白对兔骨髓间充质干细胞成软骨分化的影响*

摘要目的：观察自体富血小板纤维蛋白（platelet-rich fibrin, PRF）对体外培养的兔骨髓间充质干细胞（Bone marrow mesenchymal stemcells, BMSCs）成软骨分化的影响。方法：兔心脏采血制备PRF,电镜观察其超微结构;分离培养兔BMSCs,取第3代细胞用于 实验,分为PRF组、阳性对照组、空白对照组。诱导培养21d 后,对三组细胞分别进行形态学观察,成软骨鉴定染色（甲苯胺蓝、II 型胶原免疫组化染色）,软骨相关基因表达检测（Ⅱ型胶原、Aggrecan、SOX9）。结果：PRF 组和阳性对照组中BMSCs经诱导后,细 胞由长梭形变为三角形、多角形、圆形;甲苯胺蓝、II 型胶原免疫组化染色均为阳性;Ⅱ型胶原、Aggrecan、SOX9基因表达水平均 较高,两组比较无统计学差异,空白对照组未见相关分化现象。结论：PRF在体外可促进兔BMSCs 成软骨分化,可作为自体生物 材料,在构建组织工程软骨中发挥更好的作用。     

phbB,phbC Gene Expression in E. coli and Their Transformation and Identification in Potato

Using NADPH-dependent acetoacetyl-CoA reductase gene (phbB) and poly-β-hydroxybutyrate (PHB) synthase gene (phbC) cloned from Alcaligenes eutrophus H16 and expression vector pKK223-3, the authors constructed an E. coli expression vector pKCB containing independent phbB and phbC operators, respectively, and transfered it into E. coli JM109. The microscopy and GC analysis indicated that E. coli JM109 (containing pKCB) induced by IPTG could synthesize poly-β- hydroxybutyrate (PHB). By DNA processing, three tuber-specific plant expression vectors, pP- SAGB (containing phbB), pBIBGC ( containing phbC) and pPSAGCB ( containing both phbB and phbC), were successfully constructed. In 5 transformed potato cuhivars, the authors screened 20 positive lines.     

The developmental fate of green fluorescent mouse embryonic germ cells in chimeric embryos

Primordial germ cells (PGCs),as precursors of mammalian germ lineage,have been gaining more attention as a new resource of pluripotent stem cells,which bring a great possibility to study developmental events of germ cell in vitro and at animal level.EG4 cells derived from 10.5 days post coitum (dpc) PGCs of 129/svJ strain mouse were established and maintained in an undifferentiated state.With an attempt to study the differentiation capability of EG4 cells with a reporter protein:green fluorescence protein,and the possible application of EG4 cells in the research of germ cell development,we have generated several EG4-GFP cell lines expressing enhanced green fluorescence protein (EGFP) and still maintaining typical characteristics of pluripotent stem cells.Then,the differentiation of EG4-GFP cells in vitro as well as their developmental fate in chimeric embryos which were produced by aggregating EG4-GFP cells to 8-cell stage embryos were studied.The results showed that EG4 cells carrying green fluorescence have a potential use in the research of germ cell development and other related studies.     

高等植物春化作用研究进展

环境因子（ 低温诱导或称春化作用） 在高等植物的生长发育调控中起着重要作用。本文就近年来春化作用诱导的开花启动研究领域中的进展从春化过程中的多步骤性、成花决定过程控制的多途径性、接受春化刺激的位置与分化启动的关系、以及春化作用的分子机理等几个方面进行了简要综述。并对春化相关基因克隆方面的进展进行了分析和综述     

Ⅰ期临床试验病房规范化管理的探讨

目的:规范药物Ⅰ期临床试验病房的各项管理标准。方法:分析、总结Ⅰ期临床试验研究人员、受试者、试验药物、病房监护等方面的管理经验和体会。其中受试者管理包括受试者的招募、知情同意、筛选、入住、饮食、用药、观察及采血、出组,试验药物的管理包括试验药物的验收、存放、领用、使用和回收处理。结果:通过分析、总结Ⅰ期临床试验病房的各个管理环节中可能存在的问题,提出规范化、系统化的管理要求。Ⅰ期临床试验研究人员应经过系统化的GCP培训,严格按照试验方案执行;受试者应在全面知情同意后参加试验,并遵守病房各项规章制度;试验药物应按照要求妥善保管,在各个环节监控和记录试验药物的流向;病房监护应做到抢救设备定期维护,抢救药品定期更换,专人负责保管。结论:通过规范化流程和系统管理,能够有效地降低Ⅰ期临床试验存在的风险。     

Relationships between stream macroinvertebrates and environmental variables at multiple spatial scales

1. Aquatic communities are structured by multiple forces, and identifying the driving factors over multispatial scales is an important research issue. The East Asian monsoon region is globally one of the richest environments in terms of biodiversity, and is undergoing rapid human development, yet the river ecosystems in this region have not been well studied. We applied a hierarchical framework to incorporate regional and local environmental effects on stream macroinvertebrate communities in this region. The knowledge gained is expected to improve the understanding of the importance of spatial scale on regional and local diversity in the East Asian monsoon region. 2. A national data set of benthic macroinvertebrates and environmental variables (geographical, land‐use, hydrological, substratum and physicochemical elements) in Korean rivers was used to determine the habitat preferences of macroinvertebrates. 3. Latitude, proportion of forest coverage, riffle habitat, silt substratum and temperature were the most important determinants for the ordinations of macroinvertebrate communities in each category evaluated by canonical correspondence analysis (CCA). The optimal habitats for stream macroinvertebrates are not the same for all species, and overall community metrics and abundance of sensitive species tended to be lower in open agricultural and urban streams than in forested streams. The sensitivity of mayflies and stoneflies to anthropogenic disturbances implicated them as good indicators to assess the effects of urban and agricultural activities. 4. A partial CCA was used to evaluate the relative importance of macrohabitat and microhabitat variables on community composition at three spatial scales (whole country, the large Han River basin and two small sub‐basins in the lowlands and highlands). The majority of community variation (17–22% for each environmental element) was explained by macrohabitat variables at the regional spatial scale. In contrast, large proportions (15–18%) were explained by microhabitat variables at the local spatial scale. 5. Our findings indicate that the relative importance of habitat scales should be determined by geographical size and that comprehensive understanding of multispatial scale patterns can be important for implementing sound biodiversity conservation programmes.     

Ni^2＋ treatment causes cement gland formation in ectoderm explants of Xenopus laevis embryo

We found T-type calcium channel blocker Ni^2 can efficiently induce the formation of cement gland in Xenopus laevis animal cap explants.Nother T-typer specific calcium channel blocker Amiloride can also induce the formation of cement gland,while L-type specific calcium channel blocker Nifedipine as no inductive effect.These results may offer us an new approach to study the differentiation of cement gland through the change of intracelluar calcium concentration.     

洞庭湖区黑线姬鼠食性调查

于2009年4月至2011年6月,在洞庭湖区湖滩、滨湖农田、防洪堤坝3种生境中捕捉黑线姬鼠(Apodemus agrarius)223只,观察胃内容物,分析了洞庭湖区黑线姬鼠的食性。结果表明:洞庭湖区3种生境中黑线姬鼠的食物组成都以植物种子为主,总计达(66.55±2.37)%,其次为植物茎、叶,其比例为(19.01±2.13)%,植物根所占比例为(8.27±1.05)%,动物性食物为(6.05±0.97)%。但黑线姬鼠的食物组成会随着不同生境、季节而有一定的变化。种子资源相对较少的季节和生境,相应的黑线姬鼠的食物组成中的种子所占比例就会较低。同一生境中,幼年鼠和亚成年鼠的食物组成与成年鼠、老年鼠区别较大,孕期雌鼠与同季节、同生境的非孕期雌鼠相比也有较大差异。说明尽管黑线姬鼠以取食植物种子为主,但其食性会随着生境可获得资源的不同而有所调整。     

Geographic variation in offspring size of a widespread lizard (Takydromus septentrionalis): importance of maternal investment

Geographic variation in offspring size is widespread, but the proximate causes of this variation have not yet been explicitly determined. We compared egg size and egg contents among five populations of a lizard (Takydromus septentrionalis, Günther, 1864) along a latitudinal gradient, and incubated eggs at two temperatures to determine the influence of maternal investment and incubation temperature on offspring size. The mean values for female size and egg size were both greater in the two northern populations (Chuzhou and Anji) than in the three southern populations (Lishui, Dongtou, and Ningde). The larger eggs were entirely attributable to the body size of females in the Anji population, but their increased size also stemmed from further enlargement of egg size relative to female body size in Chuzhou, the northernmost population sampled in this study. Eggs of the Chuzhou population contained more yolk and less water than those of southern populations. Despite the lower lipid content in the yolk, eggs from the Chuzhou population had higher energy contents than those from the two southern populations, owing to the larger egg size and increased volume of yolk. Hatchling size was not affected by incubation temperature, but differed significantly among populations, with hatchlings being larger in the Chuzhou population than in the other populations. Our data provide an inference that oviparous reptiles from cold climates may produce larger offspring, not only by increasing egg size but also by investing more energy into their eggs. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 101 , 59–67.