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   117篇
  免费   4篇
儿科学   10篇
基础医学   24篇
临床医学   1篇
内科学   10篇
神经病学   59篇
特种医学   2篇
外科学   3篇
预防医学   4篇
药学   7篇
肿瘤学   1篇
  2022年   2篇
  2021年   2篇
  2020年   1篇
  2019年   2篇
  2018年   1篇
  2017年   1篇
  2016年   3篇
  2015年   1篇
  2014年   5篇
  2013年   13篇
  2012年   10篇
  2011年   7篇
  2010年   4篇
  2009年   7篇
  2008年   8篇
  2007年   7篇
  2006年   9篇
  2005年   9篇
  2004年   9篇
  2003年   7篇
  2002年   1篇
  2001年   4篇
  2000年   2篇
  1999年   1篇
  1997年   1篇
  1992年   1篇
  1990年   1篇
  1988年   1篇
  1987年   1篇
排序方式: 共有121条查询结果,搜索用时 15 毫秒
1.
This study investigated the contribution of genetic and environmental influences on the stability of aggressive behavior from early childhood to adolescence. Two developmental models, the simplex model and the common factor model, were tested to study the underlying processes of stability and change. Measures of aggressive behavior (AGG) were obtained from maternal CBCL data as part of a large ongoing longitudinal study of the Netherlands Twin Registers (NTR) and included data from 6488 three-year-old twin pairs, 5475 seven-year-old twin pairs, 2983 ten-year-old twin pairs, and 1509 twelve-year-old twin pairs. AGG showed moderate to high stability during childhood. The stability coefficients ranged from 0.41 to 0.77 across varying intervals. Averaged across boys and girls, genetic factors accounted for approximately 65% of the total stability. Longitudinal genetic analysis indicated a simplex model for genetic effects, which suggests a dynamic development process consisting of transmission of existing genetic effects interacting with new genetic influences. This is especially true at age 7, when the influence of new genetic factors was large. Shared environmental factors accounted for approximately 25% of phenotypic stability, and it seemed that a stable set of the same shared environmental factors underlay the development of AGG. Nonshared environmental factors, when important, are age specific. Sex-specific differences for stability were identified. For boys, genetic influences were greater, whereas for girls shared environmental factors were more important. These data support the idea that both genetic and environmental influences play a role in the stability of AGG from age 3 to 12.  相似文献   
2.
Maternal and Child Health Journal - This is a pilot study of the Vermont Family Based Approach, an innovative health promotion program designed to address behavioral health prevention in primary...  相似文献   
3.
BACKGROUND: Genetic influences have been shown to play a major role in determining the risk of attention-deficit hyperactivity disorder (ADHD). In addition, prenatal exposure to nicotine and/or alcohol has also been suggested to increase risk of the disorder. Little attention, however, has been directed to investigating the roles of genetic transmission and prenatal exposure simultaneously. METHOD: Diagnostic telephone interview data from parents of Missouri adolescent female twin pairs born during 1975-1985 were analyzed. Logistic regression models were fitted to interview data from a total of 1936 twin pairs (1091 MZ and 845 DZ pairs) to determine the relative contributions of parental smoking and drinking behavior (both during and outside of pregnancy) as risk factors for DSM-IV ADHD. Structural equation models were fitted to determine the extent of residual genetic and environmental influences on ADHD risk while controlling for effects of prenatal and parental predictors on risk. RESULTS: ADHD was more likely to be diagnosed in girls whose mothers or fathers were alcohol dependent, whose mothers reported heavy alcohol use during pregnancy, and in those with low birth weight. Controlling for other risk factors, risk was not significantly increased in those whose mothers smoked during pregnancy. After allowing for effects of prenatal and childhood predictors, 86% of the residual variance in ADHD risk was attributable to genetic effects and 14% to non-shared environmental influences. CONCLUSIONS: Prenatal and parental risk factors may not be important mediators of influences on risk with much of the association between these variables and ADHD appearing to be indirect.  相似文献   
4.
Amino diacid 3, a highly selective competitive GluR5 kainate receptor antagonist, exhibited high GluR5 receptor affinity and selectivity over other glutamate receptors. Its diethyl ester prodrug 4 was orally active in two models of migraine: the neurogenic dural plasma protein extravasation model and the nucleus caudalis c-fos expression model. These data suggest that a GluR5 kainate receptor antagonist might be an efficacious antimigraine therapy with a novel mechanism of action.  相似文献   
5.
OBJECTIVE: To estimate the genetic and environmental contributions to oppositional defiant behavior (ODB) from mother, father, and teacher report using the Conners Revised Short Forms in a large twin sample. METHOD: ODB data were collected from 1,595 mothers, 1,114 fathers, and 793 teachers of 7-year-old twin pairs from the Netherlands Twin Registry in the 1990-1992 cohort with an 80% response rate. Models were fit for each informant to determine the genetic, environmental, gender, and informant influences on ODB. RESULTS: Genetic analyses of the ODB quantitative scale showed additive genetic (A) by mother (55%), by father (57%), and by teacher (21% girls, 38% boys) unique environmental (E) (mother, 22%; father, 29%; teacher, 48% girls, 39% boys) and shared environmental (C) (mother, 14%; father, 23%; teacher, 31% girls, 23% boys) influences. CONCLUSIONS: Additive genetic and unique environmental factors account for the majority of the influences on ODB for boys and girls by all informants.  相似文献   
6.
7.
A number of studies have reported associations between the serotonin transporter gene (SLC6A4) and alcohol, heroin, cocaine, or methamphetamine abuse. Other studies have yielded contrary results. There are a number of reasons for non-replication, including inadequate statistical power, population stratification, and poor phenotype definition. This study was to test the association using a meta-analytic approach across a variety of racial and ethnic populations. Using the genotype data of 55 studies (7999 cases, 8264 controls, and 676 families or parent-offspring trios) published in the past 15 years, we have conducted comprehensive meta-analyses to examine the associations of the 5-HTTLPR and STin2 polymorphisms with substance use disorder. The meta-analyses support the associations of 5-HTTLPR with alcohol, heroin, cocaine, and methamphetamine dependence and abuse (eg, the smallest P-values were 0.0058 with odds ratio (OR)=0.54 (0.35, 0.84); 0.0024 with OR=0.77 (0.66, 0.91); 0.018 with OR=1.38 (1.06, 1.81); and 0.028 with OR=0.46 (0.23, 0.92) for alcohol, heroin, cocaine, and methamphetamine dependence/abuse, respectively). When all the phenotypes are combined, the P-value was 0.0006 with OR=0.86 (0.78, 0.94) in the combined European, Asian, and Mexican populations and P-value was 0.0028 with OR=1.41 (1.13, 1.78) in the African populations. Evidence of significant associations was also identified in other subgroup analyses regarding differently combined substance and populations. The effect sizes of 5-HTTLPR were comparable among the European, Asian, and Mexican populations, however, the risk allele was more frequent in Asians than in Europeans and Mexicans. The opposite directions of risk allele in African population might be driven by the opposite directions of risk allele in cocaine dependence. This meta-analysis supports that the association of the SLC6A4 gene with substance use disorder varies depending on substances with different risk allele frequencies in the multi-cultural populations. Further studies using larger sample size are warranted.  相似文献   
8.
The HER2 gene encodes a cell-surface glycoprotein with extensive homology to the epidermal growth factor receptor. Recently it was found to be amplified in about 30% of primary human breast malignancies. In experiments designed to assess the role of the HER2 gene in oncogenesis, we found that overexpression of unaltered HER2 coding sequences in NIH 3T3 cells resulted in cellular transformation and tumorigenesis.  相似文献   
9.
High levels of expression of either the epidermal growth factor receptor or the receptor-like HER2/neu gene product p185HER2 have been observed in a variety of human malignancies. Because of the association of this high level expression with certain human tumors, we have generated a panel of monoclonal antibodies specific for either the epidermal growth factor receptor or p185HER2 to study their structure, function, and antigenic domains in the normal and neoplastic states. We used the epidermoid carcinoma line A431 to generate five monoclonal antibodies which immunoprecipitate the epidermal growth factor receptor. These monoclonal antibodies bind to the extracellular domain of the epidermal growth factor receptor and demonstrate variable effects on epidermal growth factor binding. We used a stably transfected NIH 3T3 cell line expressing the HER2/neu gene to produce and characterize 10 monoclonal antibodies which immunoprecipitate p185HER2. These monoclonal antibodies bind to the extracellular domain of p185HER2 and do not cross-react with the epidermal growth factor receptor. The characteristics and potential applications of these monoclonal antibodies will be discussed.  相似文献   
10.
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