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   13963篇
  免费   1121篇
  国内免费   386篇
耳鼻咽喉   151篇
儿科学   227篇
妇产科学   267篇
基础医学   1959篇
口腔科学   281篇
临床医学   1471篇
内科学   2520篇
皮肤病学   198篇
神经病学   962篇
特种医学   931篇
外国民族医学   4篇
外科学   1545篇
综合类   1056篇
现状与发展   1篇
一般理论   2篇
预防医学   915篇
眼科学   209篇
药学   1228篇
  4篇
中国医学   445篇
肿瘤学   1094篇
  2023年   130篇
  2022年   184篇
  2021年   457篇
  2020年   355篇
  2019年   362篇
  2018年   369篇
  2017年   357篇
  2016年   350篇
  2015年   442篇
  2014年   556篇
  2013年   605篇
  2012年   829篇
  2011年   746篇
  2010年   507篇
  2009年   451篇
  2008年   670篇
  2007年   685篇
  2006年   664篇
  2005年   616篇
  2004年   605篇
  2003年   613篇
  2002年   543篇
  2001年   554篇
  2000年   447篇
  1999年   348篇
  1998年   149篇
  1997年   162篇
  1996年   104篇
  1995年   95篇
  1994年   82篇
  1993年   71篇
  1992年   157篇
  1991年   177篇
  1990年   160篇
  1989年   171篇
  1988年   138篇
  1987年   135篇
  1986年   111篇
  1985年   115篇
  1984年   82篇
  1983年   69篇
  1979年   90篇
  1978年   49篇
  1977年   45篇
  1976年   49篇
  1975年   46篇
  1974年   67篇
  1973年   61篇
  1972年   57篇
  1970年   54篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Zedoary tumeric (Curcumae Rhizoma, Ezhu in Chinese) has a long history of application and has great potential in the treatment of liver cancer. The anti liver cancer effect of zedoary tumeric depends on the combined action of multiple pharmacodynamic substances. In order to clarify the specific mechanism of zedoary tumeric against liver cancer, this paper first analyzes the mechanism of its single pharmacodynamic substance against liver cancer, and then verifies the joint anti liver cancer mechanism of its "pharmacodynamic group". By searching the research on the anti hepatoma effect of active components of zedoary tumeric in recent years, we found that pharmacodynamic substances, including curcumol, zedoarondiol, curcumenol, curzerenone, curdione, curcumin, germacrone, β-elemene, can act on multi-target and multi-channel to play an anti hepatoma role. For example, curcumin can regulate miR, GLO1, CD133, VEGF, YAP, LIN28B, GPR81, HCAR-1, P53 and PI3K/Akt/mTOR, HSP70/TLR4 and NF-κB. Wnt/TGF/EMT, Nrf2/Keap1, JAK/STAT and other pathways play an anti hepatoma role. Network pharmacological analysis showed that the core targets of the "pharmacodynamic group" for anti-life cancer are AKT1, EGFR, MAPK8, etc, and the core pathways are neuroactive live receiver interaction, nitrogen metabolism, HIF-1 signaling pathway, etc. At the same time, by comparing and analyzing the relationship between the specific mechanisms of pharmacodynamic substance and "pharmacodynamic group", it is found that they have great reference significance in target, pathway, biological function, determination of core pharmacodynamic components, formation of core target protein interaction, in-depth research of single pharmacodynamic substance, increasing curative effect and so on. By analyzing the internal mechanism of zedoary tumeric pharmacodynamic substance and "pharmacodynamic group" in the treatment of liver cancer, this paper intends to provide some ideas and references for the deeper pharmacological research of zedoary tumeric and the relationship between pharmacodynamic substance and "pharmacodynamic group".  相似文献   
2.
Cervical cancer is a global health challenge in women. Neoadjuvant chemotherapy (NACT) is a recent prospect for alternative cervical cancer treatments. This study investigated the efficacy of NACT against resectable cervical cancer based on the medium and long-term survival of patients with the disease. We searched through PubMed, Web of Science, EBSCO and Cochrane Library for relevant reports published by June 2020. The primary outcomes were 3-year and 5-year progression-free survival (PFS) and overall survival (OS) of patients with resectable cervical cancer. Overall, 22 publications encompassing 5627 patients fulfilled the inclusion criteria. We found NACT not to affect both 3-year PFS and OS as well as 5-year PFS of patients with resectable cervical cancer. However, NACT significantly improves the 5-year OS of patients with resectable cervical cancer (HR = 0.83, 95% CI: 0.73–0.94, p = 0.013). Subgroup analysis (RCTs, non-RCTs, NACT + surgery + AT vs. surgery + AT, NACT + surgery + AT vs. CCRT/RT/CRT) further revealed NACT had no significant effect on 5-year PFS of patients with resectable cervical cancer, converse to the 5-year OS subgroup analysis, which validated the beneficial effect of NACT in patients with resectable cervical cancer. In addition, the effect of NACT was most significant in the non-RCTs subgroup (p = 0.012). NACT may improve the long-term prognosis of patients with resectable cervical cancer. However, further large-scale multicenter studies are needed to validate this finding.  相似文献   
3.
艾灸作为中医学最古老的疗法之一,作用多样,应用广泛,疗效显著。随着科技的发展,人们对灸法的认识逐渐深入,其中艾烟的相关研究也硕果累累,其安全性广受关注。通过对艾烟作用和安全性评价研究中取得的成果进行归纳分析,以期为艾灸临床安全应用提供指导。  相似文献   
4.

Background

In the emergency department, rib fractures are a common finding in patients who sustain chest trauma. Rib fractures may be a sign of significant, underlying pathology, especially in the elderly patients where rib fractures are associated with significant morbidity and mortality. To date, no studies have evaluated the ability of ultrasound to detect rib fractures using cadaver models and subsequently use this model as a teaching tool.

Objectives

The purpose of this study was to determine if it is possible to generate rib fractures on cadaver models which could be accurately identified using ultrasound.

Methods

This was a cross-sectional study performed during one session at a cadaver lab. A single hemithorax from four adult cadavers were used as models. Single rib fractures on each of rib five through eight were created. Four subjects, blinded to the normal versus fractured ribs, were asked to identify the presence of a fracture on each rib.

Results

A total of 8 of 16 potential ribs had fractured induced by study staff. Mean accuracy was 55% for all subjects. The overall sensitivity and specificity for detecting rib fractures was 50% (CI: 31.89–68.11) and 59.38% (CI: 35.69–73.55) respectively. The overall PPV and NPV was 55.17% and 54.29% respectively.

Conclusions

In this pilot study, subjects were not able to detect induced rib fractures using ultrasound on cadaver models. The use of this model as a teaching tool in the detection of rib fractures requires further investigation.  相似文献   
5.
6.
7.
8.
目的 探讨非阻塞性冠状动脉粥样硬化患者血管内皮功能与左室舒张功能的关系。方法 选取2013.6~2015.6宣武医院心脏内科收治的因胸痛疑诊冠心病、经冠脉造影检查证实为非阻塞性冠状动脉粥样硬化症(冠状动脉狭窄<50%)患者119例,其中男性55例,女性64例,年龄31~85岁,平均年龄60岁。专业培训人员采用标准化问卷调查记录患者临床资料,行超声心动图和肱动脉血流介导内皮依赖性血管舒张功能(FMD)检测,分为FMD正常组(FMD>10%)和减低组(FMD≤10%)。结果 两组人群基本临床资料无显著性差异(P值均>0.05)。左室结构指标室间隔厚度、左室后壁厚度、左室舒张末内径、左室质量指数两组间比较无显著性差异(P值均>0.05)。左室收缩功能指标每搏输出量、心输出量、左室短轴缩短率及射血分数组间比较也无显著性差异(P值均>0.05)。FMD降低组较FMD正常组E/A比值显著减低(P<0.001)、E/e’比值显著升高(P=0.006),控制年龄等影响因素,偏相关分析显示FMD与E/A比值存在显著正相关(r=0.261,P=0.005),FMD与E/e’呈显著负相关(r=-0.203,P=0.033)。结论 在非阻塞性冠状动脉粥样硬化人群中,内皮功能与左室舒张功能密切相关,内皮功能不全患者左室舒张功能明显减退。  相似文献   
9.
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