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   4194篇
  免费   481篇
  国内免费   232篇
耳鼻咽喉   42篇
儿科学   73篇
妇产科学   61篇
基础医学   410篇
口腔科学   46篇
临床医学   484篇
内科学   749篇
皮肤病学   61篇
神经病学   242篇
特种医学   124篇
外国民族医学   2篇
外科学   491篇
综合类   732篇
预防医学   239篇
眼科学   61篇
药学   408篇
  6篇
中国医学   230篇
肿瘤学   446篇
  2024年   19篇
  2023年   79篇
  2022年   148篇
  2021年   211篇
  2020年   142篇
  2019年   156篇
  2018年   161篇
  2017年   158篇
  2016年   128篇
  2015年   149篇
  2014年   177篇
  2013年   210篇
  2012年   274篇
  2011年   284篇
  2010年   241篇
  2009年   193篇
  2008年   208篇
  2007年   220篇
  2006年   194篇
  2005年   194篇
  2004年   190篇
  2003年   268篇
  2002年   233篇
  2001年   141篇
  2000年   112篇
  1999年   81篇
  1998年   61篇
  1997年   44篇
  1996年   49篇
  1995年   26篇
  1994年   28篇
  1993年   16篇
  1992年   20篇
  1991年   15篇
  1990年   18篇
  1989年   8篇
  1988年   10篇
  1987年   5篇
  1986年   6篇
  1985年   4篇
  1984年   3篇
  1983年   6篇
  1982年   4篇
  1981年   4篇
  1978年   1篇
  1977年   2篇
  1975年   1篇
  1963年   1篇
  1962年   1篇
  1948年   2篇
排序方式: 共有4907条查询结果,搜索用时 421 毫秒
1.
目的:探讨微波配合序贯扩肛治疗陈旧性肛裂的临床疗效。方法:选取陈旧性肛裂患者78例,随机分为对照组和治疗组,每组各39例。对照组患者采用后卫内括约肌部分切断治疗,治疗组患者采用微波配合序贯扩肛治疗。结果:观察组患者术中出血量、切口愈合时间均少于对照组(P<0.05),并发症发生率低于对照组(P<0.05)。结论:采用微波配合序贯扩肛治疗陈旧性肛裂,临床疗效显著。  相似文献   
2.

Background

There were few studies assessed the postoperative sarcopenia in patients with cancers. The objective of present study was to assess whether postoperative development of sarcopenia could predict a poor prognosis in patients with adenocarcinoma of esophagogastric junction, (AEG) and upper gastric cancer (UGC).

Methods

Patients with AEG and UGC who were judged as non-sarcopenic before surgery were reassessed the presence of postoperative development of sarcopenia 6 months after surgery. Patients were divided into the development group or non-development group, and clinicopathological factors and prognosis between these two groups were analyzed.

Results

The 5-year overall survival rates were significantly poorer in the development group than non-development group (68.0% vs. 92.6%, P?=?0.0118). Multivariate analyses showed that postoperative development of sarcopenia was an independent prognostic factor for poor overall survival (P?=?0.0237).

Conclusions

Postoperative development of sarcopenia was associated with a poor prognosis in patients with AEG and UGC.  相似文献   
3.
A pathological feature in atherosclerosis is the dysfunction and death of vascular endothelial cells (EC). Oxidized low‐density lipoprotein (LDL), known to accumulate in the atherosclerotic arterial walls, impairs endothelium‐dependent relaxation and causes EC apoptosis. A major bioactive ingredient of the oxidized LDL is lysophosphatidylcholine (LPC), which at higher concentrations causes apoptosis and necrosis in various EC. There is hitherto no report on LPC‐induced cytotoxicity in brain EC. In this work, we found that LPC caused cytosolic Ca2+ overload, mitochondrial membrane potential decrease, p38 activation, caspase 3 activation and eventually apoptotic death in mouse cerebral bEND.3 EC. In contrast to reported reactive oxygen species (ROS) generation by LPC in other EC, LPC did not trigger ROS formation in bEND.3 cells. Pharmacological inhibition of p38 alleviated LPC‐inflicted cell death. We examined whether heparin could be cytoprotective: although it could not suppress LPC‐triggered Ca2+ signal, p38 activation and mitochondrial membrane potential drop, it did suppress LPC‐induced caspase 3 activation and alleviate LPC‐inflicted cytotoxicity. Our data suggest LPC apoptotic death mechanisms in bEND.3 might involve mitochondrial membrane potential decrease and p38 activation. Heparin is protective against LPC cytotoxicity and might intervene steps between mitochondrial membrane potential drop/p38 activation and caspase 3 activation.  相似文献   
4.
5.
6.
新型冠状病毒肺炎(简称新冠肺炎, COVID-19)是近期流行的一种新发传染病,已造成大量人员感染,其中包括医务人员。为预防生殖医学的医院感染,有效降低新冠肺炎在生殖专科机构传播的风险,通过查询相关文献、指南和规范等,并结合生殖医学特点,制定生殖医学有关的临床区、手术室和实验室及相关人员预防新冠肺炎的措施。  相似文献   
7.
目的 :通过观察实验犬下腔静脉内放置可扩张性内支撑后血管的形态学变化 ,确定支撑的内皮化进程 ,以期为临床减少内支撑阻塞、合理应用抗凝剂提供组织学的依据。  方法 :在 14只杂种犬下腔静脉内放置金属内支撑 ,于术后 1个月起 ,逐月取下腔静脉作光镜和电镜检查。  结果 :术后 1个月左右 ,内支撑基本内皮化 ,5个月完成血管的重构。  结论 :早期抗凝治疗是防止内支撑阻塞的关键 ,首次提出内支撑放置后血管重构的现象  相似文献   
8.
胡尚基  张京岚 《北京医学》1997,19(4):200-202
报告78例老年咯血患者纤维支气管镜检查结果,71例获得病因诊断,诊断率9产%。咯血原因中,肺癌48例,占61.5%。其它依次是:支气管扩张12例,肺炎11例,老年人肺结核发病率低。41例肺癌的病理分型显示,鳞癌30例,小细胞癌凶,为5例。  相似文献   
9.
伊克昭盟甘草群落调查报告   总被引:2,自引:0,他引:2  
徐永厚  冯全民 《中药材》1996,19(8):384-390
通过样地调查和采挖试验,内蒙古伊克昭盟的甘草群落可划分为12个类型,并对各类群落的利用作出评估。  相似文献   
10.
Objective To observe changes of hepatic hemodynamics and hepatic functional reserve after splenectomy and periesophagogastric devascularization. Methods From July 2006 to August 2007, thirty patients with portal hypertension caused by hepatitis B cirrhosis underwent splenectomy and periesophagogastric devascuiarization. The PVPG (portal venous pressure gradient) was measured by inductor continually during operation. The HAF (hepatic artery flow), PVF (portal venours flow) and hepatic arterial RI(resistant index) were measured with Doppler sonography. The EHBF(effective hepatic blood flow) and ICGR15 (indocyaninegreen retention rate at 15 minutes) were obtained respectively by indocyaninegreen clearance test before and after the operation. Results PVPG after laparotomy (19±4) mm Hg, ligating the splenic artery(14±4) mm Hg, splenectomy(14±3)mm Hg and periesophagogastric devascularization (12±4) mm Hg showed a tendency to decrease progressively. The PVF decreased [from (42±14) ml/s to (16±8) ml/s] and HAF increased in compensation after operation. The EHBF increased [from (0.48±0.10) L/min to (0.56±0.10) L/min], and the ICGR15 decreased (from 23%±8% to 18%±4%) postoperatively. Conclusion After splenectomy and periesophagogastric devascularization, the hepatic functional reserve improves at least in a short term notwithstanding the decrease of PVPG and PVF.  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