Detecting positive darwinian selection in brain-expressed genes during human evolution

To understand the genetic basis that underlies the phenotypic divergence between human and non- human primates, we screened a total of 7176 protein-coding genes expressed in the human brain and compared them with the chimpanzee orthologs to identify genes that show evidence of rapid evolution in the human lineage. Our results showed that the nonsynonymous/synonymous substitution (Ka/Ks) ratio for genes expressed in the brain of human and chimpanzee is 0.3854, suggesting that the brain-expressed genes are under functional constraint. The X-linked human brain-expressed genes evolved more rapidly than autosomal ones. We further dissected the molecular evolutionary patterns of 34 candidate genes by sequencing representative primate species to identify lineage-specific adaptive evolution. Fifteen out of the 34 candidate genes showed evidence of positive Darwinian selection in human and/or chimpanzee lineages. These genes are predicted to play diverse functional roles in em- bryonic development, spermatogenesis and male fertility, signal transduction, sensory nociception, and neural function. This study together with others demonstrated the usefulness and power of phy- logenetic comparison of multiple closely related species in detecting lineage-specific adaptive evolu- tion, and the identification of the positively selected brain-expressed genes may add new knowledge to the understanding of molecular mechanism of human origin.     

长期有氧运动对肥胖大鼠血液及肝脏糖脂代谢的影响

将15月龄SD雄性大鼠分为正常对照组(CON)、高脂饮食组(HFD)和高脂饮食运动组(HFD+CE)。实验结束处死后取材,测定各组大鼠空腹血糖(PBG)、血清甘油三酯(TG)、胆固醇(TC)、高密度脂蛋白(HDL-C)、低密度脂蛋白(LDL-C)、肝脏TG、游离脂肪酸(FFA)及肝糖原(LG)浓度,空腹胰岛素水平(FINS)及胰岛素抵抗指数(HOMA-IR)。结果显示:与CON组相比,HFD组大鼠HDL-C、LG显著降低(P<0.01,P<0.05),PBG无显著性变化(P>0.05),TG、FINS、HOMA-IR均显著升高(P<0.05),血清TC、LDL-C、L-TG、L-FFA升高极显著(P<0.01);与HFD组相比,HFD+CE组大鼠HDL-C升高极显著(P<0.01),TC、PBG无显著变化(P>0.05),LG、L-TG、FINS、HOMA-IR均显著下降(P<0.05),LDL-C、L-FFA降低极显著(P<0.01)。结论:长期有氧运动对高脂诱导的肥胖大鼠具有明显降脂作用,并能降低血清胰岛素水平,改善胰岛素抵抗和肝脏糖脂代谢紊乱。     

黄芪、丹参配伍提取物调控大鼠脂质代谢的初步研究

研究黄芪、丹参配伍提取物对大鼠脂质代谢的影响,将高脂血症大鼠模型造模成功后随机分空白组、模型组、阳性药对照组(非诺贝特)、黄芪和丹参配伍提取物低、中、高剂量治疗组。4周后测定大鼠TC、TG、HDL-C、LDL-C、Apo AⅠ和Apo B等指标。黄芪、丹参配伍提取物高、中剂量组、阳性药对照组血清中TC、TG、LDL-C及Apo B水平均明显低于模型组,黄芪、丹参配伍提取物高、中剂量组HDL-C及Apo AⅠ水平明显高于模型组。说明黄芪、丹参配伍提取物高、中剂量组能明显降低高脂血症大鼠TG、TC和LDL-C水平,提高HDL-C水平,调节脂质代谢,并减少高脂血症大鼠发生动脉粥样硬化和冠心病的机率。     

葛根素对脂肪细胞糖脂代谢作用研究

探讨葛根素对脂肪细胞糖、脂代谢的影响.建立3T3-L1脂肪细胞IR模型,葡萄糖氧化酶法测定葛根素处理48 h后培养液中葡萄糖残存量、铜试剂显色法测定游离脂肪酸浓度.与模型组比较,葛根素高、低剂量组葡萄糖消耗量显著增加(P<0.05),游离脂肪酸水平呈现降低趋势.葛根素明显增加脂肪细胞的葡萄糖消耗,对TNF-α诱导的脂肪分解无明显作用.     

Prediction of sites under adaptive evolution in flavin-containing monooxygenases: Selection pattern revisited

Flavin-containing monooxygenase (FMO), like cytochrome P450 (CYP), is a monooxygenase that uses the reducing equivalents of NADPH to reduce one atom of molecular oxygen to water, while the other atom is used to oxidize the substrate. Recently, it was shown that some CYP isoforms have been subject to positive selection. However, it is unknown whether the highly conserved phase I detoxification enzyme, FMO, has undergone similar positive Darwinian selection. We used maximum-likelihood models of codon substitution, evolutionary fingerprinting, and cross species comparison to investigate the occurrence of adaptive evolution in FMO sequences. We used recent genomic data from a range of species, including vertebrates and invertebrates. We present the evidence for the occurrence of adaptive evolution in mammalian FMO 3, 4, 5, and fugu FMOs but not in mammalian FMO 1, FMO 2, frog FMOs, other fish FMOs and invertebrate FMOs. The sites under adaptive evolution were significantly associated with the insertion domain in mammalian FMO 5. We identified specific amino acid sites in FMOs 3–5 that are likely targets for selection based on the patterns of parallel amino acid change. The most likely role of adaptive evolution is the repair of mutations that permitted optimal NADP+ binding and improved catalytic efficiency. The occurrence of positive selection during the evolution of phase I detoxification enzymes such as FMOs 3–5 and fugu FMO suggests the occurrence of both high selection pressure acting on species within their unique habitats and significant changes in intensity and direction (forms of xenobiotics and drugs) resulting from changes in microhabitat and food.     

Using maximum likelihood method to detect adaptive evolution of HCV envelope protein-coding genes

The basic process of adaptive evolution by natural selection is the replacement of one allele gene by an- other with a higher fitness in a population. Detecting the adaptive evolution would be helpful for better un- derstanding of bio-evolutionary mechani…     

人参水提物对小鼠血糖及血脂代谢的影响

研究了人参水提物对正常小鼠血糖和血脂代谢的影响及其对四氧嘧啶(ALX)致糖尿病小鼠降血糖的作用.实验证实,200和400 mg/kg人参水提物极显著地降低了血糖;100 mg/kg水提物能够显著降低血清甘油三酯(P＜0.05),且随着剂量的增加,呈现上升的趋势.200 与400 mg/kg人参水提物均能显著降低正常小鼠餐后30 min的血糖值(P＜0.05).另外,人参水提物灌胃给糖尿病小鼠,均能降低血糖,其中300 mg/kg效果最显著(P＜0.01).研究结果表明:人参水提物可能是通过促进小鼠体内的葡萄糖转化成甘油三脂,调节了物质代谢中血糖与血清甘油三酯的相互转化.同时,人参水提物还具有改善正常小鼠的葡萄糖耐量,降低糖尿病小鼠血糖值的作用.     

Ethanol metabolism in calluses of several selected plant species on two typical plant-growth-regulator balanced media

For investigation on the characteristics of ethanol metabolism in tissues of different plant species, calluses from eight selected plant species were cultured on medium supplemented with ethanol in tightly sealed culture flasks. Changes of the ethanol level were detected by gas chromatography. During the culture period, the calluses of tobacco, potato and petunia were, able to catabolize exogenous ethanol, resulting in the prominent decline of the ethanol level in the medium. The calluses of melon and peanut were also able to catabolize thanol but with lower efficiency. The other three calluses of carrot, soybean and rice did not catabolize ethanol but instead produced small to large amount of ethanol, resulting in the increase of the ethanol level in the media. It was also found that changing the balance between auxin and cytokinin could influence only the ethanol metabolism efficiency but could not change the metabolism patterns on ethanol of the cultured calluses. It can be concluded that, ethanol metabolism pattern of calluses in cultures is an innate physiological characteristic of the respective plant species. Foundation item: Supported by the Natural Science Foundation of Guangdong Province (No. 950406) Biography: Yang Yue-sheng (1957-), male, Professor, research direction: plant physiology and plant cell engineering.     

跨国公司竞标条件下的外资并购甄选

为了研究外资并购的政府规制问题,建立经济学模型,分析了两家跨国公司以竞标形式并购国内企业一定股份的均衡价格和由此决定的利益分配与产业绩效．进一步比较分析了不同的跨国公司并购国内企业的社会福利效应,得到外资并购的甄选依据．     

大豆异黄酮对卵巢切除大鼠糖脂代谢和血清瘦素、抵抗素表达的影响

为探讨大豆异黄酮对卵巢切除大鼠糖脂代谢和血清瘦素、抵抗素表达的影响,将12周SD大鼠分成3组,假手术(Sham)组、卵巢切除(OVX)组和大豆异黄酮(OVX+Gen)组,每组7只,卵巢切除术后10 d,OVX组和Sham组大鼠每天腹腔注射生理盐水0.1 ml/只,OVX+Gen组每天注射大豆异黄酮0.2 mg/只,连续注射30 d后处死取血,检测子宫病理改变、血糖血脂和胰岛素水平、血清瘦素和抵抗素含量.结果发现卵巢切除后大鼠总胆固醇、HDL和LDL均增加(P<0.05),但胰岛素、血糖、甘油三酯、血清瘦素和抵抗素水平变化不明显(P>0.05);卵巢切除后补充大豆异黄酮,可促进子宫内膜上皮部分增生,但胰岛素、血糖、总胆固醇、甘油三酯、LDL和HDL、血清瘦素和抵抗素水平均无明显变化(与OVX组相比,P>0.05),结果提示大豆异黄酮对卵巢切除大鼠糖脂代谢参数和血清瘦素、抵抗素水平影响不大.     

等张运动与等长运动对高血压患者的心血管反应及脂蛋白代谢的影响

目的：比较等张运动与等长运动对高血压患者的心血管反应及脂蛋白代谢的影响，为高血压病运动处方的制定提供理论依据。方法：对45例老年高血压患者随机分成主要基线资料具有可比性的三组，A组采用等张练习，B组采用等长练习，C组采用等长练习＋等张练习。观察运动训练16周后血压及血脂的变化。结果：所有受试者运动训练后血压降低（P＜0.05）、血脂水平得以改善，其中以C组最为明显（P＜0.01）。结论：等张运动与等长运动相结合的全面的运动康复训练方案可以有效改善高血压患者的血压与血脂水平，有利于高血压病的康复，是高血压病运动处方的首选。     

荔枝核皂甙提取物对小鼠糖异生作用和血脂代谢的影响

目的研究荔枝核皂甙提取物对小鼠糖异生作用和血脂代谢的影响。方法取雄性昆明种小鼠20只,随机分为对照组和实验组,实验组每天以荔枝核皂甙提取物灌胃,对照组每天以生理盐水灌胃,连续灌胃3 w后,测定小鼠血糖、甘油三脂、胆固醇、肝糖元等生化指标。结果实验组糖异生具有明显的抑制作用,抑制率为13.19%;肝糖元含量明显升高,血清甘油三脂、胆固醇的水平明显降低(P<0.05)。结论荔枝核皂甙提取物对正常小鼠有调节血糖和血脂的作用。     

SIRT1与糖脂代谢及在运动医学领域的研究展望

SIRT1(silent mating type information regulation 2 homolog1),哺乳动物sir2同系物,一种NAD+依赖的组蛋白脱乙酰化酶。越来越多的证据表明SIRT1通过其脱乙酰化酶活性参与糖脂代谢,其对胰岛β细胞功能和胰岛素信号通路起着正性调节作用,对改善胰岛素的敏感性和维持糖脂代谢稳态具有重要作用。运动疗法是防治2型糖尿病、非酒精性脂肪肝和动脉粥样硬化等慢性疾病主要方法之一,但运动改善慢性疾病的机理还未完全阐明。已有研究表明运动训练能够诱导大鼠骨骼肌和心肌组织中SIRT1表达。运动改善慢性疾病机理是否与SIRT1有关尚不确定。在总结SIRT1与糖脂代谢关系的基础上,结合运动与SIRT1的研究现状,展望SIRT1在运动医学领域的研究前景。     

五阳煤矿矿井液压支架设备选型探讨

通过对五阳煤矿矿井液压支架设备选型以及液压支架选型原则的探讨,得出该矿井3-1煤综采工作面应选用ZY10800/28/63D型掩护式液压支架、2-1煤综采工作面应选用ZY2800/10/23型液压支架的结论。     

我国众创空间政策的特征与政策工具选择

运用文本量化研究方法,从政策工具类型和政策工具领域两个维度,对193个众创空间政策文件进行了分析。研究了各省众创空间政策工具特点,进而对东、中、西及东北4大区域政策特征加以总结。结果表明：各省以需求型和供给型工具为主,环境型和监管型工具相对较少,4大经济区域众创空间政策工具选择存在差异。政策建议：未来众创空间政策应渐进收缩,更突出政策的针对性与“精准化”;在制定众创空间政策时应关注区域间的产业协同效应,构建地区间良性的产业链竞合关系;应更多地应用环境型政策工具。本研究结果对于未来众创空间政策制定具有一定指导和启示作用。     

过度有氧运动对不同性别成年骨代谢相关激素的影响

为研究过度有氧运动对不同性别成年骨代谢相关激素的影响,选取某学院体育系的80名学生作为研究对象,其中男生40人,女生40人,随机将其划分成对照组和训练组,训练组受试者需进行大强度的健美操训练,对照组受试者在此期间不进行任何训练,针对不同性别的研究对象进行不同指标测试研究。实验发现训练组不同性别成年人实验后体重非常显著性低于实验前和对照组;脂肪百分比和瘦体重和实验前及对照组相比有显著性差异。长期过度有氧运动能够降低成年男性血睾酮含量,对骨代谢激素产生不利影响;同时,长期过度有氧运动会使女性骨代谢负平衡。因此,不建议成年人长期进行有氧过度运动。     

河曲发电厂二期工程烟囱结构选型

简述了脱硫烟气的特点及腐蚀性,根据电厂采用湿法脱硫,提出两种选择方案,并对其经济性与优缺点进行了比较。     

遗传算法中常用选择算子在MATLAB中的实现

在数学软件MATLAB中，没有遗传算法的程序，本文编写了遗传算法中常用的四种选择算子的MATLAB语言程序，并在一最优化问题上进行测试。     

引黄工程连接段备用水源方案比选及工程选址研究

阐述了项目建设区域的基本情况以及引黄工程供水系统和太原市供水状况,论证了项目建设的必要性和迫切性,分析了备用水源方案比选及项目选址的情况及其可行性。