人TRAIL基因cDNA的克隆及其在COS—7细胞中的表达

ＴＲＡＩＬ(ＴＮＦｒｅｌａｔｅｄａｐｏｐｔｏｓｉｓｉｎｄｕｃｉｎｇｌｉｇａｎｄ)是最近克隆的肿瘤坏死因子(ＴＮＦ)家族的新成员,由于它的蛋白质结构和生物学效应类似于ＦＡＳ/ＡＰＯ1Ｌ,因此,也被称为ＡＰＯ2Ｌ。在低浓度下,ＴＲＡＩＬ能迅速地诱导多种肿瘤细胞系的?..     

High throughput screening of hydrolytic enzymes from termites using a natural substrate derived from sugarcane bagasse

Background

Short rotation coppice willow is a potential lignocellulosic feedstock in the United Kingdom and elsewhere; however, research on optimising willow specifically for bioethanol production has started developing only recently. We have used the feedstock Salix viminalis × Salix schwerinii cultivar 'Olof' in a three-month pot experiment with the aim of modifying cell wall composition and structure within the stem to the benefit of bioethanol production. Trees were treated for 26 or 43 days with tension wood induction and/or with an application of the cellulose synthesis inhibitor 2,6-dichlorobenzonitrile that is specific to secondary cell walls. Reaction wood (tension and opposite wood) was isolated from material that had received the 43-day tension wood induction treatment.

Results

Glucan content, lignin content and enzymatically released glucose were assayed. All measured parameters were altered without loss of total stem biomass yield, indicating that enzymatic saccharification yield can be enhanced by both alterations to cell wall structure and alterations to absolute contents of either glucan or lignin.

Conclusions

Final glucose yields can be improved by the induction of tension wood without a detrimental impact on biomass yield. The increase in glucan accessibility to cell wall degrading enzymes could help contribute to reducing the energy and environmental impacts of the lignocellulosic bioethanol production process.     

羌活与宽叶羌活的群体遗传结构和种间分化研究

为了合理利用羌活和宽叶羌活的药用植物资源,同时保护其物种多样性,该研究利用SSR分子标记技术对羌活与宽叶羌活邻域及异域分布的23个自然种群,共计227个个体进行多样性和种间分化研究.结果显示:(1)两个物种具有中等水平的遗传多样性;羌活的平均等位基因数(Na)、有效等位基因数(Ne)和期望杂合度(He)分别为2.603...     

非酒精性脂肪肝大鼠PPARα基因表达及脂代谢和胰岛素水平的变化

目的观察非酒精性脂肪肝（NAFLD）大鼠肝组织中PPARα基因的表达,并用PPARct激动剂进行干预,探讨其与胰岛素抵抗、脂代谢紊乱的关系。方法大鼠随机分为①正常对照组、②高脂模型组、③PPARα激动剂干预组,利用高脂饮食建立大鼠非酒精性脂肪肝模型。12周后,检测大鼠血脂、肝功能、血糖、胰岛素水平及胰岛素抵抗指数;RT-PCR法分析PPARα基因的表达;观察肝脏的形态学改变。结果PPARa激动剂可降低NAFLD大鼠转氨酶、血脂水平及胰岛素抵抗指数,可促进NAFLD大鼠中PPARa基因的表达;肝脏形态学明显改善。结论PPARα激动剂能改善NAFLD大鼠脂质代谢紊乱,有明显的保肝降酶作用,具有适度的胰岛素增敏作用。PPARα及其配体在NAFLD发病机制及治疗中的进一步深入研究,将为临床防治NAFLD提供新的思路。     

蒙古高原岩黄芪属植物的分支分类学研究

以蒙古高原岩黄芪属植物为对象, 应用徐克学的最大同步法, 探讨了蒙古高原岩黄芪属(豆科)植物的系统演化, 并根据分支分类结果对蒙古高原岩黄芪属进行了系统学处理。作者首次将蒙古高原岩黄芪属分为岩黄芪亚属、半灌木岩黄芪亚属(新拟)和无刺岩黄芪组、丛枝岩黄芪组、无茎岩黄芪组、半灌木岩黄芪组等4 个组。本文对蒙古高原岩黄芪组的划分符合苏联植物志(1945)中的观点。     

Home-range Use by a Large Horde of Wild <Emphasis Type="Italic">Mandrillus sphinx</Emphasis>

The predicted relationship between home-range size and group mass in primates developed by Clutton-Brock and Harvey (1977) has proved extremely robust in describing the use of space by most primate species. However, mandrills (Mandrillus sphinx) are now known to have an extreme group mass in the wild, far larger than that of the species used originally to generate that relationship, and so it was unknown whether this relationship would be robust for this species. We investigated the home-range size and use of a wild horde of ca. 700 mandrills in Lopé National Park, Gabon, using radiotelemetry. The total area the horde used over a 6-yr period [100% minimum convex polygon (MCP)] was 182 km², including 89 km² of suitable forest habitat. Mandrills used gallery forests and isolated forest fragments with high botanical diversity far more intensively that the continuous forest and completely avoided savanna and marsh. Peeled polygons and fixed kernel contours revealed multiple centres of use, with the horde spending more than half its time in <10% of the total documented range, typical of a frugivore using a patchy environment. Home-range size and internal structure varied considerably between years, but total home range fitted the predicted relationship between group mass and home range size, despite being an outlier to the dataset. We discuss the conservation implications of the species’ space requirements, in light of current pressures on land use in their range.     

The detection and monitoring of early pregnancy in the vervet monkey (Cercopithecus aethiops) with the use of ultrasound and correlation with reproductive steroid hormones

Twenty early pregnancies were diagnosed and monitored in vervet monkeys by ultrasonography. Non-gravid uteri became increasingly echogenic from cycle days 7 to 26. The first definite sign of pregnancy was a gestational cavity of 2 mm (+/- 0.80) at 33.0 (+/- 1.48) days menstrual age, which was also used to date all subsequent features. Earlier signs, such as an endometrial line swelling or endometrial 'pregnancy' ring, as reported for other non-human primate species, could not be reliably and consistently used to diagnose pregnancy in vervet monkeys. A rapid increase of the gestational cavity size from days 37 to 49 corresponded closely to a rapid increase in plasma progesterone concentration from day 39 to 49. The first yolk sac was recognizable at 38.0 days (+/- 3.10) and measured 3.3 mm (+/- 0.40) in diameter. A heart beat could be detected at 45.5 (+/- 1.73) days and the size of the first measurable embryo at 35 days was 2 mm. The dating of most features was within the range reported for other non-human primate species.