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   390547篇
  免费   21557篇
  国内免费   5939篇
耳鼻咽喉   4626篇
儿科学   9551篇
妇产科学   8617篇
基础医学   53743篇
口腔科学   11683篇
临床医学   30322篇
内科学   83072篇
皮肤病学   9177篇
神经病学   30653篇
特种医学   11160篇
外国民族医学   40篇
外科学   44717篇
综合类   14471篇
现状与发展   14篇
一般理论   96篇
预防医学   38939篇
眼科学   9287篇
药学   31863篇
  80篇
中国医学   5572篇
肿瘤学   20360篇
  2023年   2729篇
  2022年   4888篇
  2021年   9417篇
  2020年   6052篇
  2019年   8229篇
  2018年   13059篇
  2017年   8939篇
  2016年   8252篇
  2015年   10315篇
  2014年   12348篇
  2013年   15875篇
  2012年   26389篇
  2011年   27975篇
  2010年   14990篇
  2009年   11540篇
  2008年   22218篇
  2007年   23099篇
  2006年   21931篇
  2005年   21398篇
  2004年   19030篇
  2003年   17816篇
  2002年   16744篇
  2001年   10973篇
  2000年   12335篇
  1999年   9593篇
  1998年   2937篇
  1997年   2404篇
  1996年   2086篇
  1995年   1903篇
  1994年   1575篇
  1993年   1203篇
  1992年   4019篇
  1991年   3510篇
  1990年   3325篇
  1989年   2880篇
  1988年   2582篇
  1987年   2470篇
  1986年   2409篇
  1985年   2175篇
  1984年   1617篇
  1983年   1327篇
  1979年   1588篇
  1974年   1444篇
  1973年   1508篇
  1972年   1381篇
  1971年   1357篇
  1970年   1253篇
  1969年   1295篇
  1968年   1347篇
  1967年   1221篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Molnár  B.  Aroca  S.  Dobos  A.  Orbán  K.  Szabó  J.  Windisch  P.  Stähli  A.  Sculean  A. 《Clinical oral investigations》2022,26(12):7135-7142
Clinical Oral Investigations - To evaluate t he long-term outcomes following treatment of RT 1 multiple adjacent gingival recessions (MAGR) using the modified coronally advanced tunnel (MCAT) with...  相似文献   
3.
目的 应用可视化方法分析代谢组学在中医药领域的现状及趋势。方法 检索中国知网数据库(CNKI)和Web of Science 核心合集数据库2021年3月15日之前收录的中医药领域代谢组学研究的相关文献,应用CiteSpace软件对纳入的文献进行关键词、作者、研究机构等内容进行可视化分析。结果 共纳入中文文献247篇,英文文献350篇。文献数量在波动中迅速上升。中、英文文献作者合作网络显示,张爱华是中医药领域代谢组学研究发文量最多的作者,并形成了核心研究团队。发文机构显示,中国医学科学院是该领域的重要研究机构,机构间合作紧密。中、英文文献关键词分析显示,研究内容主要集中在核磁共振、代谢标记物、冠心病、质谱技术、代谢通路等相关领域。结论 中医药领域代谢组学研究的热点主要为中医药治疗代谢性疾病的机制研究。研究趋势为卵泡代谢组学研究及中药有效成分的研究。  相似文献   
4.
In clinical and epidemiological studies, there is a growing interest in studying the heterogeneity among patients based on longitudinal characteristics to identify subtypes of the study population. Compared to clustering a single longitudinal marker, simultaneously clustering multiple longitudinal markers allow additional information to be incorporated into the clustering process, which reveals co-existing longitudinal patterns and generates deeper biological insight. In the current study, we propose a Bayesian consensus clustering (BCC) model for multivariate longitudinal data. Instead of arriving at a single overall clustering, the proposed model allows each marker to follow marker-specific local clustering and these local clusterings are aggregated to find a global (consensus) clustering. To estimate the posterior distribution of model parameters, a Gibbs sampling algorithm is proposed. We apply our proposed model to the primary biliary cirrhosis study to identify patient subtypes that may be associated with their prognosis. We also perform simulation studies to compare the clustering performance between the proposed model and existing models under several scenarios. The results demonstrate that the proposed BCC model serves as a useful tool for clustering multivariate longitudinal data.  相似文献   
5.

The exercise pressor reflex is a feedback mechanism engaged upon stimulation of mechano- and metabosensitive skeletal muscle afferents. Activation of these afferents elicits a reflex increase in heart rate, blood pressure, and ventilation in an intensity-dependent manner. Consequently, the exercise pressor reflex has been postulated to be one of the principal mediators of the cardiorespiratory responses to exercise. In this updated review, we will discuss classical and recent advancements in our understating of the exercise pressor reflex function in both human and animal models. Particular attention will be paid to the afferent mechanisms and pathways involved during its activation, its effects on different target organs, its potential role in the abnormal cardiovascular response to exercise in diseased states, and the impact of age and biological sex on these responses. Finally, we will highlight some unanswered questions in the literature that may inspire future investigations in the field.

  相似文献   
6.
International Journal of Clinical Oncology - Immune-checkpoint inhibitors (ICIs) are standard treatments for metastatic non-small cell lung cancer (NSCLC). Patients with poor performance status...  相似文献   
7.
8.
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   
9.
Journal of Immigrant and Minority Health - COVID-19 has disproportionally affected underrepresented minorities (URM) and low-income immigrants in the United States. The aim of the study is to...  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