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排序方式: 共有808条查询结果,搜索用时 15 毫秒
1.
AMPK在妊娠期糖尿病发病机制中的作用 总被引:1,自引:0,他引:1
腺苷酸活化蛋白激酶是一种重要的蛋白激酶,主要作用是协调代谢和能量平衡.腺苷酸活化蛋白激酶被激活后,在增加骨骼肌对葡萄糖摄取、增强胰岛素敏感性、增加脂肪酸氧化以及调节基因转录等方面发挥重要作用.已经证实脂联素有调节糖脂代谢的作用,但其作用机制尚不十分清楚,很可能是通过腺苷酸活化蛋白激酶介导,对脂联素信号转导通路的研究将成为进一步理解脂联素作用的关键所在.而脂联素又是妊娠期糖尿病的预测因子,所以腺苷酸活化蛋白激酶逐渐成为对妊娠期糖尿病研究中的焦点. 相似文献
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Carol A. Shively Ph.D. Stephen B. Manuck Ph.D. Jay R. Kaplan Ph.D. Donald R. Koritnik Ph.D. 《Archives of sexual behavior》1990,19(2):101-117
The effects of oral contraceptive administration on the social relationships of adult female cynomolgus monkeys (Macaca fascicularis) were examined. Ten females were administered ethinyl estradiol/ethynodiol diacetate (Demulen), 10 were administered ethinyl estradiol/norgestrel (Ovral), and 10 served as a control group. The monkeys lived in social groups of 5 females each, and patterns of social interaction and social status were recorded. Interfemale relationships were also observed when a vasectomized male was placed in each social group for 50 min, once/week. During the latter observations, preliminary data on the effects of oral contraceptive treatment on sexual interaction were also collected. In the absence of the male, interfemale agonistic interactions and time spent alone were influenced by social status but not by oral contraceptive treatment. Time spent in passive body contact, an affiliative state, was reduced by Ovral treatment. In the presence of the male, dominant females aggressively interfered with the sexual interactions of subordinates. This aggression resulted in the termination of a greater proportion of the sexual interactions of subordinates than dominants in the control group only, indicating suppression of this type of interaction by oral contraceptive treatment. Other effects included a decreased frequency of ejaculation with Ovral-treated females. These results suggest that oral contraceptives may suppress certain types of female agonistic behavior (e.g., in the context of mate competition) and some oral contraceptives may interfere with sexual activity. More broadly, these findings indicate that intrasexual competition for access to mates may occur in females as well as males.
This study was supported in part by NICHD Contract #N01-HD-32800 and by Grant #HL14164 from the National Heart, Lung and Blood Institute. 相似文献
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Although millions of hypertensive individuals receive chronic treatment with antihypertensive medication, the effect on the central nervous system by these drugs is poorly understood. Such treatment, while generally well tolerated, frequently produces symptoms of drowsiness, weakness, altered memory and impaired concentration. In addition to subjective evidence derived from patient reports, a large number of investigations have now been published which attempt to objectively assess the influence of antihypertensive medication on behavioral or cognitive performance. This paper summarizes and critically evaluates experimental studies of the effect of antihypertensive medication on subjects' performance of neuropsychological tasks and reviews the pharmacologic mechanisms by which these drugs may affect behavior. The literature is incomplete in its assessment of all domains of neuropsychological performance and all drug classes, and methodologic deficiencies are common. Nonetheless, the consensus of all studies and the findings of well-designed studies in particular do not identify any notable areas of performance impairment in patients receiving antihypertensive medication. Moreover, results suggest that, in certain instances, drug treatment may even enhance performance. In light of the limitations of the literature, however, an adequate understanding of the effects of antihypertensive therapy on behavioral functioning awaits completion of large, well-designed investigations including all major drug classes and thorough neurobehavioral assessments. 相似文献
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S R Waldstein C M Ryan S B Manuck D K Parkinson E J Bromet 《Journal of consulting and clinical psychology》1991,59(4):513-517
Learning and memory processes were compared in 20 men with untreated blood pressure elevation and 20 normotensive control subjects matched for age, education, and average alcohol consumption. Subjects were identified from a larger sample of 469 factory workers who had participated in an epidemiologic investigation. Three measures (e.g., Symbol-Digit Learning Test [Ryan & Butters, 1980] and Visual Reproductions-Immediate and Delayed Recall [Wechsler, 1945] ) from a previously administered test battery were chosen for comparison on the basis of statistical power calculations. Results indicate that relative to normotensive control subjects, men with elevated blood pressure performed more poorly on all three tests. These results are independent of other known influences on neuropsychological performance and are likely a consequence of elevated blood pressure. 相似文献
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臂丛神经根性损伤膈神经移位术对青壮年患者早期呼吸功能的影响 总被引:1,自引:1,他引:0
目的研究臂丛神经损伤膈神经移位术对青壮年患者早期呼吸功能的影响.方法对16例接受膈神经移位治疗的患者,在术前、术后(10 d)进行肺功能指标的比较,同时定期进行门诊随访,观察呼吸系统自觉症状程度.结果13例术后出现了不同程度的供氧不足症状,16例全部出现一侧膈肌抬高,术后第10天肺活量(VC)、肺活量预计值百分数(VC%)分别比术前减少37.98%和26.88%,两者差异有统计学意义(tvc=11.532、tvc%=0,P<0.01).其它项目如残气量(RV)较术前轻度下降,肺总量(TLC)下降值达到术前肺总量的36.49%,残气量/肺总量比值(RV/TLC%)较术前上升了4.75%,上述各指标的差值均有统计学意义.1 s用力呼气量/用力肺活量比值(FEV1/FVC)和术前比基本无改变,但其差值有统计学意义.膈神经移位右侧(10例)与左侧(6例)术前、术后肺活量比较差异有统计学意义.术后随访8个月~2年,所有患者均无明显呼吸困难和胸闷等症状.结论膈神经移位术后对青壮年患者肺容量有较大的丧失,肺通气功能减弱和小气道阻力增加,但其丧失程度在机体自身代偿耐受范围内,不会导致急剧发生的严重呼吸功能障碍.建议对右侧臂丛神经根性损伤的患者,术前进行严格的肺、心功能检查,避免发生较为严重的并发症. 相似文献
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WANG Qing-sheng TA Na RAO Zhu-shi 《中国生物医学工程学报(英文版)》2007,16(4):148-154
It is reported that some types of insects have a remarkable ability to detect the direction of an incident sound even though its acoustic sensory organs are in very close proximity each other. Maybe the ears are jointed by a cuticular structure with which the separated motions can be coupled mechanically and thus be magnified. In this paper, a detailed model is setup to describe the principle of this type of localization using a mechanical coupled structure. The transfer functions and the responses of the model in terms of time and frequency are analyzed to describe the mechanism of its ability of directional hearing. This analytical model provides a method to design the experimental model for the predetermined incident sound pressure, and the analysis of this model shows that this structure have the ability to determine the direction of the incident stimulus. 相似文献
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藏汉民族线粒体基因组全序列的比较研究 总被引:1,自引:0,他引:1
目的 以藏汉民族线粒体基因组全序列为基础,进行Haplogroup构建和系统发生分析,在全序列水平上比较核苷酸的变异,阐释可能的变异机制和蕴含的生物学意义.方法 采用Applied Biosystems 3730DNA自动测序仪分别对40名藏族和50名汉族的标本进行线粒体DNA序列测定,应用phredPhrap 16.0软件进行全序列拼接,并以rCRS(revised Cambridge Reference Sequence)为标准与测定序列进行比对分析;根据MTTO-MAP的标准,通过Network方法进行Haplogroup构建和系统发生的分析,并结合其它方法对产生的数据进行深入解读.结果 数据分析结果显示:在系统发生上,藏汉民族90个线粒体DNA序列归类到13个Haplogroups,除M9以外,其它各Haplogroup出现频率之间比较差异无统计学意义;通过两个民族的线粒体DNA全序列比对,发现21个分布频率有统计学意义的变异位点,其中的5个为新变异位点;另外,对D-Loop区的5个突变位点进行了单倍型构建,90个标本可分为2种Supertype,发现在藏汉民族之间Supertypel和Supertype 2的分布频率均有统计学意义.结论 藏汉民族在种族起源和系统发生上具有较近的母系遗传关系;在全序列有统计学意义的位点究竟是适应性或者中性选择,抑或是一种病理性突变尚需深入的探讨. 相似文献