大熊猫的生境选择特征

基于王朗国家级自然保护区1997—2009年的连续监测数据,利用分布频率法和Bai-ley法,从地形因子、森林群落结构和主食竹3个方面研究了大熊猫的生境选择特征.结果表明:王朗国家级自然保护区的大熊猫对生境具有明显的选择性.在地形上,多选择海拔在2500～3000 m的山体脊部、上部和中部的均匀坡和凸坡,坡向西南,坡度在6°～30°,与水源距离>300 m的环境;森林群落结构上,多选择起源为次生林、针阔混交林,微生境为竹林的生境,乔木平均高度在20～29 m,灌木盖度在0～24%;主食竹多选择平均高度在2～5 m,竹丛盖度>50%,混生,生长状况良好的缺苞箭竹.     

MPEG-PCL Copolymeric Micelles for Encapsulation of Azithromycin

Macrolide antibiotics are lipophilic drugs with some limitations including low solubility, limited cellular permeation, patients discomfort, etc. With amphiphilic methoxy poly(ethylene glycol)-b-poly(ε-caprolactone) (MPEG-PCL) copolymer and azithromycin (AZT) as drug carrier and model drug, AZT-loaded micelles were prepared via thin-membrane hydration method in order to overcome these limitations. Encapsulation efficiency of AZT-loaded micelles was 94.40% with good storage stability for 28 days, and AZT’s water solubility was enhanced to 944 μg/mL. Fourier transform infrared spectrum and x-ray diffraction analysis indicated that AZT was enveloped into the micelles in amorphous form due to its interaction with the copolymer. AZT’s in vitro release from the AZT-loaded micelles demonstrated a slow and continuous behavior when compared with raw AZT. The release dynamics was accorded with Weibull equation, meaning that release amount of AZT lowered with time and was proportional to remaining amount of drug in the AZT-loaded micelles. Korsmeyer-Peppas fitting result suggested that drug release process was a classical Fickian diffusion-controlled manner. With Staphylococcus aureus as bacterial strain, antibacterial activity of the AZT-loaded micelles displayed was comparable with raw AZT. In conclusion, MPEG-PCL should be a promising carrier for macrolide antibiotic delivery in treatment of bacterial infections.     

甘露寡糖对断奶仔猪肠道主要菌群的影响

选择健康的 35日龄断奶仔猪 4 8头 ,随机分为两组 ,每组 3圈 ,每圈 8头。一组为含 0 .5 %甘露寡糠 +基础日粮 ,另一组为基础日粮。试验开始第 7天 ,每组各随机选 6头仔猪 ,麻醉后剖腹取肠道内容物以测定盲肠和结肠大肠杆菌、乳酸杆菌及双歧杆菌浓度和 p H。试验结果表明 ,与对照组相比 ,甘露寡糖可以显著降低盲肠、结肠大肠杆菌浓度 (P<0 .0 5 ) ;同时显著提高盲肠乳酸杆菌和双歧杆菌浓度 (P<0 .0 5 ) ,但对结肠乳酸杆菌和双歧杆菌数影响不显著 (P>0 .0 5 )     

Medium‐Chain Oil Reduces Fat Mass and Down‐regulates Expression of Adipogenic Genes in Rats

Objective: To test the hypothesis that adipose tissue could be one of the primary targets through which medium‐chain fatty acids (MCFAs) exert their metabolic influence. Research Methods and Procedures: Sprague‐Dawley rats were fed a control high‐fat diet compared with an isocaloric diet rich in medium‐chain triglycerides (MCTs). We determined the effects of MCTs on body fat mass, plasma leptin and lipid levels, acyl chain composition of adipose triglycerides and phospholipids, adipose tissue lipoprotein lipase activity, and the expression of key adipogenic genes. Tissue triglyceride content was measured in heart and gastrocnemius muscle, and whole body insulin sensitivity and glucose tolerance were also measured. The effects of MCFAs on lipoprotein lipase activity and adipogenic gene expression were also assessed in vitro using cultured adipose tissue explants or 3T3‐L1 adipocytes. Results: MCT‐fed animals had smaller fat pads, and they contained a considerable amount of MCFAs in both triglycerides and phospholipids. A number of key adipogenic genes were down‐regulated, including peroxisome proliferator activated receptor γ and CCAAT/enhancer binding protein α and their downstream metabolic target genes. We also found reduced adipose tissue lipoprotein lipase activity and improved insulin sensitivity and glucose tolerance in MCT‐fed animals. Analogous effects of MCFAs on adipogenic genes were found in cultured rat adipose tissue explants and 3T3‐L1 adipocytes. Discussion: These results suggest that direct inhibitory effects of MCFAs on adiposity may play an important role in the regulation of body fat development.     

Laplacian normalization and bi-random walks on heterogeneous networks for predicting lncRNA-disease associations

Background

Evidences have increasingly indicated that lncRNAs (long non-coding RNAs) are deeply involved in important biological regulation processes leading to various human complex diseases. Experimental investigations of these disease associated lncRNAs are slow with high costs. Computational methods to infer potential associations between lncRNAs and diseases have become an effective prior-pinpointing approach to the experimental verification.

Results

In this study, we develop a novel method for the prediction of lncRNA-disease associations using bi-random walks on a network merging the similarities of lncRNAs and diseases. Particularly, this method applies a Laplacian technique to normalize the lncRNA similarity matrix and the disease similarity matrix before the construction of the lncRNA similarity network and disease similarity network. The two networks are then connected via existing lncRNA-disease associations. After that, bi-random walks are applied on the heterogeneous network to predict the potential associations between the lncRNAs and the diseases. Experimental results demonstrate that the performance of our method is highly comparable to or better than the state-of-the-art methods for predicting lncRNA-disease associations. Our analyses on three cancer data sets (breast cancer, lung cancer, and liver cancer) also indicate the usefulness of our method in practical applications.

Conclusions

Our proposed method, including the construction of the lncRNA similarity network and disease similarity network and the bi-random walks algorithm on the heterogeneous network, could be used for prediction of potential associations between the lncRNAs and the diseases.

     

黄腹角雉生态群养技术研究

模拟黄腹角雉野外生存环境和自然种群结构,采用较大空间散放与多个体群养相结合的方法进行饲养试验,其笼养繁殖性能比对照组传统对养方式显著提高．通过两年来的试验研究,结果表明：试验组平均产卵量为8．5枚,卵受精率为82．6％,受精卵孵化率为88．7％;对照组平均产卵量5．7枚,卵受精率50．3％,受精卵孵化率72．4％,试验组明显高于对照组．同时对两组间的卵重、卵形、产卵期进行了测定,无显著差异。     

卤虫中编码DM结构域的DNA序列的克隆和初步研究（简报）

性别决定的分子机制复杂多样,但是处于动物性别决定的基因调控网络底部的一些调控基因具有相当高的保守性。doublesex(dsx)基因和male abnomal-3(mab-3)基因分别是果蝇(Drosophila melanogaster)和线虫(Caenorhabditis elegans)性别决定调控途径末端的重要基因,对这两个基因序列的比较导致了DM结构域的发现,它是已知在性别发育过程中最为保守的DNA结合结构域。目前,已     

LIM蛋白家族的研究进展

LIM蛋白是分子结构中含有一个或多个LIM结构域的蛋白质家族,该家族中的蛋白质通过其LIM结构域与某些结构蛋白,激酶,转录调控因子等多种蛋白质相互作用,对某些基因的表达,细胞分化与发育,细胞骨架形成等发挥重要调控作用。本文介绍LIM蛋白家族的分类与功能,LIM蛋白及其与其他蛋白之间的相互作用,以及LIM蛋白在心血管系统中的作用。     

文山松毛虫质型多角体病毒（DpwCPV）NS5蛋白基因的cDNA克隆及序列分析

通过对文山松毛虫质型多角体病毒(Dendrolimus punctatus Wenshanensis cytoplasmic polyhedrosis virus, DpwCPV)的增殖、纯化,获得一株单一类型的质型多角体病毒。提纯的病毒粒子经SDS热酚法抽提得到基因组dSRNA,使用低熔点琼脂糖凝胶电泳分离并回收纯化第九片段S9。S9 RNA双链经高温变性,逆转录合成cDNA双链。根据DpwCPV与BmCPV1的同源性设计引物,将S9进行PCR扩增后,克隆到PMD18T载体上。最终获得一个977bp的序列,其中包含一个963bp的开放阅读框(ORF)。推测DpwCPV S9基因编码一个320个氨基酸的蛋白,分子量约为35560。