亚麻籽油的营养特性研究进展

亚麻籽油的营养价值已得到普遍认可,对于其功效及作用机制分别以人或动物为实验对象开展了广泛的研究.本文首先对油脂风味、脂肪酸组成、微量营养成分和氧化稳定性四个影响亚麻籽油营养价值的因素进行了阐述,在此基础上重点综述了亚麻籽油在降血脂、降血压、降血糖、改善认知功能和改善眼睛疾病等方面的最新研究进展.     

巯基化壳聚糖包裹人参纳米颗粒的制备

目的:制备巯基化壳聚糖包裹的且具有良好的荧光敏感性的人参纳米颗粒.方法:采用分子嫁接法和溶剂挥发法,合成巯基化壳聚糖.利用得到的巯基化壳聚糖包裹人参纳米颗粒,制备巯基化壳聚糖人参纳米颗粒.加入对巯基敏感的荧光试剂,利用荧光显微镜对其荧光活性进行检测.结果:巯基化壳聚搪包裹的人参纳米颗粒形状规则,具有核-壳结构,湿态下平均粒径约为300nm;同时在生理pH下具有很强的荧光活性.结论:巯基化壳聚糖包裹的人参纳米颗粒具有良好的缓释作用和荧光敏感性.     

真社会性生活方式在隧蜂亚科中的分布格局

对隧蜂的各种生活方式的涵义作了解释。基于文献资料,总结了营真社会性生活方式的种类在隧蜂亚科中的分布格局,旨在为研究昆虫真社会性的起源和进化奠定理论基础。     

汉族人群NOS3 A-922G、NOS3 T-786C与NOS3 G894T SNP的等位基因及其组合分布与高血压的相关性

为了分析汉族人群一氧化氮合酶基因NOS3 A-922G、NOS3 T-786C与NOS3 G894T单核苷酸多态性(sin-gle nucleotide polymorphism,SNP)的等位基因及其组合分布与高血压病的相关性,选取无亲缘关系的高血压病人192例(男97例,女95例)以及无亲缘关系的健康个体122例(男76例,女46例)为对照组,提取静脉血白细胞基因组DNA,采用等位基因特异性引物PCR技术检测NOS3 A-922G、NOS3 T-786C与NOS3 G894T 3个位点的基因型.其结果显示:高血压病组与对照组NOS3 G894T、NOS3A-922G及NOS3 T-786C各等位基因型及其基因单倍型频率比较无显著性差异(P＞0.05).男、女性别分层研究:无论男亚组还是女亚组均未发现NOS3 A-922G、NOS3T-786C与NOS3 G894T各个位点SNP与高血压病有相关性.等位基因组合分布研究发现NOS3 G894G A-922G T-786T组合基因型总体频率分布在高血压病组与正常对照组之间有显著性差异(P＜0.05,x2=4.5944).男、女性别分层研究:男亚组上述3个位点SNP的各个组合基因型分布频率在高血压病组与正常对照组之间无显著性差异(P＞0.05);女亚组中携带NOS3 G894G A-922G T-786C的组合基因型分布频率在高血压病组与正常对照组之间有显著性差异(P＜0.01,x2=8.502).研究发现,在中国汉族人群中NOS3A-922 G、NOS3 T-786C与NOS3G894T SNP与高血压病无明确的相关性,且无性别差异.组合分布研究发现,NOS3 G894G A-922G T-786C的组合基因型分布频率在高血压病女性亚组较健康女性亚组明显减低,提示携带该组合基因型女性人群可能不易患高血压病.     

Phenol red interacts with the protofibril-like oligomers of an amyloidogenic hexapeptide NFGAIL through both hydrophobic and aromatic contacts

Amyloid-associated diseases affect millions of people worldwide. Phenol red exhibits modest inhibition toward fibril formation of human Islet amyloid polypeptide (hIAPP) and its toxicity, which is associated with type II diabetes mellitus. However, the molecular level mechanisms of interactions remain elusive. The binding of phenol red molecules to the protofibrils of an amyloidogenic fragment (NFGAIL) of hIAPP has been investigated by molecular dynamics simulations with explicit solvent. The phenol red molecules were observed to bind primarily along either beta-sheet stacking or beta-strand directions. Through its three aromatic rings, the phenol red molecule preferentially interacted with the hydrophobic side chains of Phe, Leu, and Ile; and the polar sulfone and hydroxyl groups were mainly exposed in solvent. Thus, phenol red improves the solubility of the early protofibrils and represses further growth. Interestingly, there was no obvious preference toward the aromatic Phe residue in comparison to the hydrophobic Leu or Ile residues. The lack of binding along the hydrogen bond direction indicates that phenol red does not directly block the beta-sheet extension. Further free energy analysis suggested that a phenol red analog may potentially improve the binding affinity.     

短时低温对马铃薯甲虫种群增长的影响

[目的]马铃薯甲虫Leptinotarsa decemlineata是我国重要的检疫性害虫,对茄科植物危害严重.本研究旨在明确出现倒春寒短时低温对马铃薯甲虫种群增长的影响.[方法]马铃薯甲虫卵在8℃下分别处理1,3和5d,以27℃下饲养的卵作为对照,调查卵孵化率及孵化后幼虫的生长发育和成虫繁殖情况,用种群参数评估短时低...     

蜜蜂卵巢激活研究进展

蜜蜂Apis作为典型的社会性昆虫,最重要的特征就是生殖劳动分工。卵巢激活是蜜蜂发挥生殖能力的重要影响因素。本文对蜜蜂卵巢激活的影响因素、蜜蜂卵巢激活相关的基因表达及microRNA在蜜蜂卵巢激活过程中的可能作用进行了介绍,为研究蜜蜂级型分化和生殖劳动分工的分子机制提供依据。     

Regional species richness,hydrological characteristics and the local species richness of assemblages of North American stream fishes

1. Local assemblage structure, from a deterministic perspective, is presumably dictated by the regional species pool as well as regulated by local factors. We examined the relationships of the regional species pool and local hydrological characteristics to local species richness of North American freshwater fishes using data sets collected during the National Water Quality Assessment program conducted by the United States Geological Survey. 2. We predicted that local species richness is ultimately constrained by the composition of the regional species pool and further associated with local hydrological factors. Moreover, we predicted that variation in local species richness within major families can be explained by different combinations of hydrological characteristics that represent lineage‐specific responses to the environment. 3. Daily discharge and regional and local species richness data were assembled from 41 stream localities across the United States. Multiple stepwise regressions were conducted to predict local species richness, based on regional species richness, mean discharge and hydrological characteristics quantified by nine variables characterising flow variability. Species richness at each site was calculated for the entire assemblage as well as within the four most species‐rich families in the data set (Catostomidae, Centrarchidae, Cyprinidae and Percidae). 4. Local species richness was best predicted by a combination of regional species richness and discharge magnitude when all species were considered. Regional species richness was a significant explanatory variable of local species richness for three of four families (Catostomidae, Centrarchidae, Cyprinidae), but not for Percidae. Local richness in Centrarchidae and Cyprinidae was positively correlated with temporal flow variability as well as high and low flow duration, respectively, while richness in Catostomidae and Percidae tended to be associated with discharge volume. In addition, local species richness for three of the four major families was positively correlated with species richness of the other families in the assemblage, potentially suggesting the influence of local habitat quality and heterogeneity. 5. Results suggest the importance of the combined influences of the regional species pool and local hydrological characteristics on local richness in freshwater fishes, with variation in richness within each family predicted by different characteristics of flow regimes.     

The extremely high level expression of human serum albumin in the milk of transgenic mice

The recombinant production of human serum albumin has been challenging due to the low unit price and huge amount needed, for the commercial production of rhSA at an economically feasible level, It will be well worth the effort to exploit new method for the extremely high level expression of rhSA. To this end, here a hybrid gene locus strategy was employed, a 37?Kb mWAP-hSA hybrid gene locus was constructed and used as mammary gland specific expression vector, in which the 3?Kb genomic coding sequence in the 24?Kb mouse whey acidic protein (mWAP) gene locus was substituted by the 16?Kb genomic coding sequence of human serum albumin (hSA), exactly from the start codon to the end codon. Corresponding transgenic mice were generated and rhSA was secreted into the milk at an extremely high level of 11.9?g/L. Our transgenic mice carrying the mWAP-hSA hybrid gene locus represent a model system for the cost-effective production of human serum albumin.