首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   173篇
  免费   3篇
教育   94篇
科学研究   70篇
各国文化   1篇
文化理论   3篇
信息传播   8篇
  2022年   1篇
  2021年   3篇
  2020年   2篇
  2018年   7篇
  2017年   4篇
  2016年   8篇
  2015年   4篇
  2014年   14篇
  2013年   24篇
  2012年   4篇
  2011年   6篇
  2010年   7篇
  2009年   11篇
  2008年   7篇
  2007年   6篇
  2006年   4篇
  2005年   6篇
  2004年   5篇
  2003年   4篇
  2002年   4篇
  2001年   6篇
  2000年   7篇
  1999年   2篇
  1998年   1篇
  1997年   3篇
  1996年   4篇
  1995年   1篇
  1994年   3篇
  1993年   1篇
  1992年   1篇
  1990年   2篇
  1989年   2篇
  1986年   2篇
  1984年   4篇
  1983年   1篇
  1979年   1篇
  1976年   1篇
  1964年   2篇
  1925年   1篇
排序方式: 共有176条查询结果,搜索用时 15 毫秒
161.
162.
163.
164.
This study evaluated the extent of oxidative stress by measuring malondialdehyde and ascorbic acid in the seminal plasma of human subjects with different fertility potential. Semen samples from 148 subjects were evaluated (48 normozoospermics, 34 oligoasthenoteratozoospermics, 34 asthenoteratozoospermics and 32 azoospermics). malondialdehyde level was found to be significantly higher in the abnormal groups (oligoasthenoterato and asthenoterato-zoospermics) than normozoospermics (P < 0.01). Negative correlation was also found between malondialdehyde level, sperm concentration, sperm motility and sperm morphology. Level of ascorbic acid was found to be significantly higher in normozoospermics than other abnormal groups (P < 0.01). It was found to be correlated positively with all seminogram parameters and negatively with malondialdehyde level. The study revealed that, excess lipid peroxidation reflected by high malondialdehyde level with reduced ascorbic acid in human seminal plasma is associated with poor semen quality where as ascorbic acid content has positive correlation with fertility potential.  相似文献   
165.
High ambient temperature has been reported to increase oxidative stress by increasing lipid peroxidation and decreasing antioxidant defence in transition dairy cows. It is also known to cause an increase in plasma cortisol levels in goats, European hedgehog and human volunteers. High levels of glucocorticoids have been reported to decrease blood glutathione and erythrocyte superoxide dismutase activity in rats. Although institutional animal houses in research laboratories of developed countries maintain animals in air-conditioned rooms at constant temperature, the same is not true of animal houses in the developing countries especially those belonging to smaller institutions and this could affect the results of the experiments being conducted on these animals. The present research study was done to assess the effects of seasonal variations on the status of erythrocyte oxidative damage, antioxidant defence and plasma cortisol levels in adult female Wistar rats. Rats were kept in their home cages and were left in non-air-conditioned procedure rooms in two different seasons, Hot season (March-May) and Cool season (June to September). Erythrocyte Thiobarbituric acid reactive substances and plasma cortisol levels were significantly increased in rats exposed to high ambient temperature and humidity of the hot season as compared to the rats of the cool season. Erythrocyte reduced glutathione levels, erythrocyte glutathione peroxidase and superoxide dismutase activities were significantly decreased in the hot season group of rats. The results of our experiments showed that exposure of adult female Wistar rats to high ambient temperature and humidity of the hot season increases neuroendocrine stress, oxidative stress and decreases antioxidant defence in them.  相似文献   
166.
OBJECTIVE: This study examined the association between childhood sexual abuse (CSA) and parenting outcomes including parenting stress, feelings of competence and discipline strategies. Maternal depression and current partner violence were hypothesized to be mediators of the association between CSA and parenting. METHOD: This study is based on secondary data analysis of archived data. The participants were 263 primiparous mothers (107 with a history of CSA and 156 comparison mothers recruited from a prenatal clinic prior to the birth of their first child. Mothers were interviewed twice: once when they were between 28 and 32 weeks gestation and again when their child was between 2 and 4 years of age. During the first interview, women were asked about childhood experiences of sexual abuse. During their second interview, they were asked about current symptoms of pathology and experiences with partner violence and parenting beliefs and practices. RESULTS: Structural Equation Modeling indicated that the relationship between CSA and punitive discipline was mediated by maternal depression and current partner violence. CSA was associated with higher maternal depression and higher partner violence. CSA, maternal depression, and current partner violence were associated with more negative parental perceptions and higher punitive discipline. Once maternal depression and current partner violence were in the model, the relationship between CSA and parenting outcomes was no different from zero. CONCLUSION: These results highlight the risks associated with CSA for parenting outcomes and suggest two potential pathways for this increased risk.  相似文献   
167.
Levels of Atrial Natriuretic Peptide (ANP) were estimated in twenty four blood samples collected from the right and the left ventricles of the patients undergoing cardiac catheterization by an Enzyme Linked Immunosorbent Assay (ELISA) developed to the sensitivity of 5 pp/well and within 10% of interassay coeficient of variance. Simultaneously, levels of ANP in plasma samples from the systemic venous blood of seventy five normal subjects were also estimated which ranged between 25–60 pg/ml.  相似文献   
168.
169.
170.
Medically diagnosed alcoholics can be differentiated reliably from non-alcoholics using clinically laboratory tests. In the present study, patients with liver diseases either due to alcohol or without alcohol compared with a group of normal healthy persons. Heavy drinkers showed significantly lower body weight and percent body fat, and low BMI compared with other groups. The percentage of hemoglobin and total number of RBC were found to be significantly decreased, whereas mean corpuscular volume (MCV) significantly increased in alcoholic liver disease (ALD). Hyperbilirubinemia, hyperuricemia and hypoalbuminemia correlate with alcohol intake. Albumin/globulin ratio significantly decreased in ALD. In acute liver injury AST/ALT ratio is ≤1.0, whereas in alcoholic hepatitis it is always >1.0. Moderately elevated level of ALP and high GGT values are good discriminator of alcoholic patients. Alcohol-induced liver injury is linked to oxidative stress as observed by decreased level of reduced glutathione and ascorbic acid, and increased level of thiobarbituric acid reactive substances.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号