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   61454篇
  免费   6436篇
  国内免费   1223篇
耳鼻咽喉   778篇
儿科学   2294篇
妇产科学   823篇
基础医学   13511篇
口腔科学   933篇
临床医学   4768篇
内科学   9947篇
皮肤病学   1643篇
神经病学   10954篇
特种医学   860篇
外国民族医学   12篇
外科学   4661篇
综合类   4720篇
现状与发展   5篇
一般理论   3篇
预防医学   2976篇
眼科学   979篇
药学   3529篇
  2篇
中国医学   1412篇
肿瘤学   4303篇
  2024年   171篇
  2023年   1148篇
  2022年   1370篇
  2021年   2241篇
  2020年   2221篇
  2019年   3070篇
  2018年   2866篇
  2017年   2850篇
  2016年   2160篇
  2015年   2442篇
  2014年   3904篇
  2013年   5615篇
  2012年   2927篇
  2011年   3167篇
  2010年   2950篇
  2009年   2888篇
  2008年   2570篇
  2007年   2500篇
  2006年   2262篇
  2005年   1889篇
  2004年   1763篇
  2003年   1597篇
  2002年   1342篇
  2001年   1033篇
  2000年   849篇
  1999年   778篇
  1998年   869篇
  1997年   795篇
  1996年   710篇
  1995年   665篇
  1994年   583篇
  1993年   475篇
  1992年   313篇
  1991年   298篇
  1990年   197篇
  1989年   147篇
  1988年   129篇
  1985年   623篇
  1984年   742篇
  1983年   495篇
  1982年   559篇
  1981年   474篇
  1980年   376篇
  1979年   400篇
  1978年   333篇
  1977年   259篇
  1976年   245篇
  1975年   264篇
  1974年   209篇
  1973年   195篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Recent epidemiological studies suggested that proton pump inhibitor (PPI) use was associated with an increased risk of biliary tract cancer (BTC), however, confounders were not adequately controlled. Our study aimed to evaluate PPI use and subsequent risk of BTC and its subtypes in three well-established cohorts. We conducted a pooled analysis of the subjects free of cancers in UK Biobank (n = 463 643), Nurses' Health Study (NHS, n = 80 235) and NHS II (n = 95 869). Propensity score weighted Cox models were used to estimate marginal HRs of PPIs use on BTC risk, accounting for potential confounders. We documented 284 BTC cases in UK Biobank (median follow-up: 7.6 years), and 91 cases in NHS and NHS II cohorts (median follow-up: 15.8 years). In UK biobank, PPI users had a 96% higher risk of BTC compared to nonusers in crude model (HR 1.96, 95% CI 1.44-2.66), but the effect was attenuated to null after adjusting for potential confounders (HR 0.95, 95% CI 0.60-1.49). PPI use was not associated with risk of BTC in the pooled analysis of three cohorts (HR 0.93, 95% CI 0.60-1.43). We also observed no associations between PPI use with risk of intrahepatic (HR 1.00, 95% CI 0.49-2.04), extrahepatic bile duct (HR 1.09, 95% CI 0.52-2.27) and gallbladder cancers (HR 0.66, 95% CI 0.26-1.66) in UK Biobank. In summary, regular use of PPIs was not associated with the risk of BTC and its subtypes.  相似文献   
5.
6.
Endolymphatic hydrops features excess endolymph in the membranous labyrinth, and is a marker of Menière's disease. Between the early 1980s and late 2000s, MRI in Menière's disease aimed purely to rule out tumor or malformation as differential diagnoses for the pressure disorder. Progress in high-resolution MRI, however, now enables excess endolymph to be visualized in the membranous labyrinth, differentiating saccule and utricle in Menière's disease and in other clinical presentations such as cochleovestibular schwannoma. More recently, non-visibility of the saccule was demonstrated in a subgroup of Menière's disease patients, and utricle atelectasis in case of uni- or bilateral vestibular areflexia. Endolymph quantification remains highly controversial in terms of grading approach, but a simple semiology based on excess or deficient visualization of endolymph according to the compartment sheds light on the pathophysiological mechanisms of cochleovestibular disorder and may in future allow effective monitoring of medical and surgical treatment.  相似文献   
7.

Background

There are well-established relationships between health and homelessness, and shelters can facilitate the transmission of diseases and contribute to their prevention. Adequate environmental health conditions and hygiene behaviors in homeless shelters are fundamental to the health of their clients, a marginalized population. We report the status of environmental health conditions and hygiene behaviors in homeless shelters and associated health outcomes; interventions to improve these conditions, behaviors, and outcomes; and obstacles to improvement.

Methods

PubMed, Web of Science, Scopus, and EBSCOhost were searched for peer-reviewed studies, and additional sources for grey literature. Studies were included if they reported primary data on one or more environmental health condition or hygiene behavior in homeless shelters.

Results

Twenty-eight studies were included in the review. Insufficient ventilation systems, unhygienic bedding, and overcrowding were the most documented environmental health and hygiene deficiencies in homeless shelters, and tuberculosis infections and skin diseases were the most documented associated health outcomes among clients. Studies frequently recommended or described implementation of behavioral and administrative controls, ventilation system improvements, and ultraviolet germicidal irradiation fixtures.

Discussion

Most studies addressed airborne transmission of tuberculosis and were conducted in high-income countries, revealing an imbalance in the literature. Insufficient resources and the transience of clients are barriers to improving hygiene behaviors and environmental conditions in homeless shelters. Further investment and research into ensuring adequate hygiene and environmental health in this setting can protect and promote the health and well-being of people experiencing homelessness.  相似文献   
8.
AimsThe effect of Origanum majorana tea consumption on motor and non-motor symptoms was investigated in patients with idiopathic Parkinson's disease, measured by validated tools.MethodsSixty patients with idiopathic Parkinson's disease and under conventional medication were enrolled voluntarily in the study. All participants were randomized on double-blind to placebo or Origanum majorana. Clinical assessment with validated tools (UPDRSIII, NMSS, and BDI) was done before Origanum majorana or placebo consumption (Day 0) and at the end of the experiment (Day 30).ResultsThe treatment groups were similar at baseline on demographic and clinical variables. During the course of study, nine participants withdrew for reasons of noncompliance and inability to follow-up. Fifty-one participants completed the study. Upon completion of 30 days of treatment, Origanum majorana tea consumption did not decrease the UPDRSIII score ([UPDRSIII] D0 = 18.76 ± 8.58, D30 = 16.52 ± 7.96, p = 0.069) at the p value was 0.07. However, a statistically significant improvement was noted in NMSS and BDI scores (p < 0.0001 and p < 0.0001, respectively). Assessment of the UPDRSIII, NMSS and BDI scores of the patients did not reflect any improvement with placebo. No side effect was detected during the study.ConclusionThese findings show improvement of depressive and non-motor signs in patients with Parkinson's disease in the group that consumed Origanum majorana tea in combination with conventional therapy. Improvement of motor signs may need an extended treatment period. However, more research with a large number of participants and lasting longer than 1 month is needed to argue these findings.  相似文献   
9.
10.
ABSTRACT

Purpose

To investigate the expression of IL-11 and its receptor IL-11Rα and to quantify density of CD163+ M2 macrophages in proliferative diabetic retinopathy (PDR).  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