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   171004篇
  免费   10931篇
  国内免费   1232篇
耳鼻咽喉   2325篇
儿科学   3368篇
妇产科学   3922篇
基础医学   25407篇
口腔科学   3526篇
临床医学   16751篇
内科学   32515篇
皮肤病学   4476篇
神经病学   13011篇
特种医学   8218篇
外科学   22665篇
综合类   2255篇
现状与发展   5篇
一般理论   99篇
预防医学   11034篇
眼科学   4412篇
药学   14307篇
中国医学   1632篇
肿瘤学   13239篇
  2023年   1057篇
  2022年   2838篇
  2021年   5020篇
  2020年   2607篇
  2019年   3783篇
  2018年   4652篇
  2017年   3417篇
  2016年   4374篇
  2015年   5852篇
  2014年   7230篇
  2013年   8857篇
  2012年   13268篇
  2011年   13051篇
  2010年   7697篇
  2009年   6418篇
  2008年   9945篇
  2007年   9804篇
  2006年   9069篇
  2005年   8629篇
  2004年   7727篇
  2003年   6690篇
  2002年   5889篇
  2001年   4458篇
  2000年   4083篇
  1999年   3355篇
  1998年   1439篇
  1997年   1070篇
  1996年   1029篇
  1995年   928篇
  1994年   816篇
  1993年   706篇
  1992年   1628篇
  1991年   1614篇
  1990年   1393篇
  1989年   1280篇
  1988年   1182篇
  1987年   1059篇
  1986年   1029篇
  1985年   907篇
  1984年   667篇
  1983年   592篇
  1982年   438篇
  1981年   421篇
  1980年   372篇
  1979年   546篇
  1978年   442篇
  1977年   403篇
  1976年   350篇
  1974年   367篇
  1973年   339篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
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   
52.
53.
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   
54.
55.
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   
56.
57.
58.
59.
60.
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