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   2998篇
  免费   180篇
  国内免费   9篇
耳鼻咽喉   46篇
儿科学   191篇
妇产科学   69篇
基础医学   422篇
口腔科学   28篇
临床医学   211篇
内科学   578篇
皮肤病学   86篇
神经病学   126篇
特种医学   107篇
外科学   320篇
综合类   172篇
预防医学   283篇
眼科学   52篇
药学   261篇
中国医学   46篇
肿瘤学   189篇
  2023年   22篇
  2022年   51篇
  2021年   106篇
  2020年   52篇
  2019年   46篇
  2018年   76篇
  2017年   52篇
  2016年   64篇
  2015年   85篇
  2014年   112篇
  2013年   127篇
  2012年   189篇
  2011年   212篇
  2010年   134篇
  2009年   87篇
  2008年   155篇
  2007年   163篇
  2006年   163篇
  2005年   137篇
  2004年   98篇
  2003年   99篇
  2002年   85篇
  2001年   90篇
  2000年   89篇
  1999年   62篇
  1998年   17篇
  1997年   12篇
  1996年   26篇
  1995年   21篇
  1993年   17篇
  1992年   42篇
  1991年   44篇
  1990年   42篇
  1989年   47篇
  1988年   38篇
  1987年   24篇
  1986年   24篇
  1985年   27篇
  1984年   15篇
  1983年   14篇
  1979年   24篇
  1978年   15篇
  1977年   13篇
  1975年   13篇
  1974年   12篇
  1973年   21篇
  1972年   12篇
  1971年   17篇
  1970年   16篇
  1969年   16篇
排序方式: 共有3187条查询结果,搜索用时 15 毫秒
101.
102.
Loss of function variants in NOTCH1 cause left ventricular outflow tract obstructive defects (LVOTO). However, the risk conferred by rare and noncoding variants in NOTCH1 for LVOTO remains largely uncharacterized. In a cohort of 49 families affected by hypoplastic left heart syndrome, a severe form of LVOTO, we discovered predicted loss of function NOTCH1 variants in 6% of individuals. Rare or low-frequency missense variants were found in 16% of families. To make a quantitative estimate of the genetic risk posed by variants in NOTCH1 for LVOTO, we studied associations of 400 coding and noncoding variants in NOTCH1 in 1,085 cases and 332,788 controls from the UK Biobank. Two rare intronic variants in strong linkage disequilibrium displayed significant association with risk for LVOTO amongst European-ancestry individuals. This result was replicated in an independent analysis of 210 cases and 68,762 controls of non-European and mixed ancestry. In conclusion, carrying rare predicted loss of function variants in NOTCH1 confer significant risk for LVOTO. In addition, the two intronic variants seem to be associated with an increased risk for these defects. Our approach demonstrates the utility of population-based data sets in quantifying the specific risk of individual variants for disease-related phenotypes.  相似文献   
103.
104.
Minireview: malonyl CoA, AMP-activated protein kinase, and adiposity   总被引:14,自引:0,他引:14  
Ruderman NB  Saha AK  Kraegen EW 《Endocrinology》2003,144(12):5166-5171
  相似文献   
105.

Background

Although associations between personality disorders and psychiatric disorders are well established in general population studies, their association with liability dimensions for externalizing and internalizing disorders has not been fully assessed. The purpose of this study is to examine associations between personality disorders (PDs) and lifetime externalizing and internalizing Axis I disorders.

Methods

Data were obtained from the total sample of 34,653 respondents from Wave 2 of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC). Drawing on the literature, a 3-factor exploratory structural equation model was selected to simultaneously assess the measurement relations among DSM-IV Axis I substance use and mood and anxiety disorders and the structural relations between the latent internalizing–externalizing dimensions and DSM-IV PDs, adjusting for gender, age, race/ethnicity, and marital status.

Results

Antisocial, histrionic, and borderline PDs were strong predictors for the externalizing factor, while schizotypal, borderline, avoidant, and obsessive-compulsive PDs had significantly larger effects on the internalizing fear factor when compared to the internalizing misery factor. Paranoid, schizoid, narcissistic, and dependent PDs provided limited discrimination between and among the three factors. An overarching latent factor representing general personality dysfunction was significantly greater on the internalizing fear factor followed by the externalizing factor, and weakest for the internalizing misery factor.

Conclusion

Personality disorders offer important opportunities for studies on the externalizing–internalizing spectrum of common psychiatric disorders. Future studies based on panic, anxiety, and depressive symptoms may elucidate PD associations with the internalizing spectrum of disorders.  相似文献   
106.
107.

Objectives

Several studies have suggested insulin resistance related to dyslipidemia and body weight in drug treated schizophrenia patients. Although, insulin resistance or impaired glucose tolerance is also reported in antipsychotic naïve schizophrenia patients, their relationship with dyslipidemic changes and body weight is not well established. The present study was undertaken to examine insulin resistance in antipsychotic naïve schizophrenia patients of this region and to evaluate any association between lipid parameters and body weight with their insulin resistance, if any.

Method

Plasma glucose, total serum cholesterol and its LDL, HDL fractions, and serum insulin levels were measured from fasting blood samples of newly diagnosed, antipsychotic naïve schizophrenia patients (n = 30) and matched control group (n = 25) in a hospital based case control study. Homoeostatic model assessment (HOMA) was done to evaluate insulin resistance.

Results

Means of plasma glucose, total serum cholesterol and its LDL, HDL fractions did not vary significantly (p > 0.05) between cases and control. Insulin resistance was significantly increased (p < 0.05) in drug naïve cases. Multiple linear regression analyses did not show any association (p > 0.05) between insulin resistance and lipid parameters.

Conclusions

Newly diagnosed schizophrenia patients were more prone to insulin resistance in our study population. This was not associated with any dyslipidemic changes as the lipid parameters were not elevated in them compared to the healthy controls. It was not dyslipidemia, but some other common genetic or risk factors that might be responsible for the increased insulin resistance in antipsychotic naïve schizophrenia patients in our study population.  相似文献   
108.
109.
110.

Ethnopharmacological relevance

Roots of Asparagus racemosus Willd (Shatavari in vernacular) are widely used in Ayurveda as Rasayana for immunostimulation, galactogogue as also in treatment of conditions like ulcers and cancer. Various studies have indicated immunomodulatory properties of Shatavari root extracts and formulations.

Aim of the study

To study the effect of standardized Asparagus racemosus root aqueous extract (ARE) on systemic Th1/Th2 immunity of SRBC sensitized animals.

Materials and methods

We used HPTLC to quantify steroidal saponins (Shatavarin IV, Immunoside®) and flow cytometry to study effects of ARE on Th1/Th2 immunity. SRBC specific antibody titres and DTH responses were also monitored as markers of Th2 and Th1 responses, respectively. We also studied lymphocyte proliferation. Cyclosporin, cyclophosphamide and levamisole were used as controls.

Results

Treatment with ARE (100 mg/(kg b.w. p.o.)) resulted in significant increase of CD3+ and CD4/CD8+ percentages suggesting its effect on T cell activation. ARE treated animals showed significant up-regulation of Th1 (IL-2, IFN-g) and Th2 (IL-4) cytokines suggesting its mixed Th1/Th2 adjuvant activity. Consistent to this, ARE also showed higher antibody titres and DTH responses. ARE, in combination with LPS, Con A or SRBC, produced a significant proliferation suggesting effect on activated lymphocytes.

Conclusion

The study suggests mixed Th1/Th2 activity of ARE supports its immunoadjuvant potential.  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