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   195947篇
  免费   13817篇
  国内免费   1399篇
耳鼻咽喉   2829篇
儿科学   3843篇
妇产科学   4517篇
基础医学   29382篇
口腔科学   3955篇
临床医学   18777篇
内科学   37606篇
皮肤病学   5234篇
神经病学   15351篇
特种医学   9656篇
外科学   26200篇
综合类   2619篇
现状与发展   5篇
一般理论   94篇
预防医学   12498篇
眼科学   5276篇
药学   16474篇
中国医学   1786篇
肿瘤学   15061篇
  2023年   1162篇
  2022年   3133篇
  2021年   5531篇
  2020年   2882篇
  2019年   4255篇
  2018年   5176篇
  2017年   3819篇
  2016年   4968篇
  2015年   6620篇
  2014年   8129篇
  2013年   9930篇
  2012年   14887篇
  2011年   14446篇
  2010年   8579篇
  2009年   7217篇
  2008年   10947篇
  2007年   10845篇
  2006年   9937篇
  2005年   9542篇
  2004年   8473篇
  2003年   7451篇
  2002年   6567篇
  2001年   5277篇
  2000年   4916篇
  1999年   4015篇
  1998年   1636篇
  1997年   1290篇
  1996年   1208篇
  1995年   1124篇
  1994年   966篇
  1993年   879篇
  1992年   2155篇
  1991年   2166篇
  1990年   1866篇
  1989年   1807篇
  1988年   1724篇
  1987年   1591篇
  1986年   1490篇
  1985年   1370篇
  1984年   1030篇
  1983年   882篇
  1982年   637篇
  1981年   593篇
  1980年   535篇
  1979年   811篇
  1978年   658篇
  1977年   566篇
  1976年   498篇
  1974年   559篇
  1973年   545篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
93.
94.
Urinary iodine concentrations (UICs) in the US have been reported to be stable since 1988–1994, although those in selected subgroups remained low. We aimed to investigate iodine status among adults (≥20 years) by two different criteria of assessing iodine deficiency in population. Utilizing National Health and Nutrition Examination Surveys 2001–2012, we conducted linear logistic regressions adjusting for covariates. The prevalence of <50?μg/L UIC was higher in women than in men; increased from 11.6% (2001–2004) to 13.2% (2009–2012) at the national level and in young adults, non-Hispanic blacks (NHBs) and non-users of iodine-containing supplements (all, p?<0.05); the adjusted odds ratios (95%CI) in young adults (1.54 [1.11–2.15], =?0.0007) and NHBs (1.70 [1.15–2.52], =?0.0078). Median UICs confirm women and NHBs being in borderline iodine status. Recognizing the critical consequence of iodine deficiency particularly in women and NHBs, regular monitoring of iodine status is important for public health in the US.  相似文献   
95.
96.
Previous epidemiologic studies have assessed the role of the exposure to ambient air pollution in the development of cardiac birth defects, but they have provided somewhat inconsistent results. To assess the associations between exposure to ambient air pollutants and the risk of cardiac defects, a population-based case-control study was conducted using 1087 cases of cardiac defects and a random sample of 10,870 controls from 1,533,748 Taiwanese newborns in 2001 to 2007.Logistic regression was performed to calculate odds ratios for 10 ppb increases in O3 and 10 μg/m3 increases in PM10. In addition, we compared the risk of cardiac defects in 4 categories-high exposure (>75th percentile); medium exposure (75th to 50th percentile); low exposure (<50th–25th percentile); reference (<25th percentile) based on the distribution of each pollutant. The risks of ventricular septal defects (VSD), atrial septal defects (ASD), and patent ductus arteriosus (PDA) were associated with 10 ppb increases in O3 exposure during the first 3 gestational months among term and preterm babies. In comparison between high PM10 exposure and reference category, there were statistically significant elevations in the effect estimates of ASD for all and terms births. In addition, there was a negative or weak association between SO2, NO2, CO, and cardiac defects.The study proved that exposure to outdoor air O3 and PM10 during the first trimester of gestation may increase the risk of VSD, ASD, and PDA.  相似文献   
97.
98.
Abstract

Purpose: We examined underlying psychosocial processes of a behavioral treatment for urinary incontinence (UI) of prostate cancer survivors.

Design: Secondary analysis of data collected from a clinical trial.

Sample: Two hundred forty-four prostate cancer survivors who participated in a clinical trial of behavioral intervention to UI as intervention or control subjects.

Methods: The participants had a 3-month behavioral intervention or usual care and were followed up for an additional 3?months. They were assessed at baseline, 3, and 6?months. Latent growth curve models were performed to examine trajectories of each study variable and relationships among the variables.

Findings: Increasing self-efficacy and social support were significantly and independently associated with more reduction of urinary leakage frequency over time.

Implications for psychosocial oncology: Providing problem-solving skills and social support, including peer support, are essential for empowering patients to reduce UI.  相似文献   
99.
100.
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