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   13546篇
  免费   1030篇
  国内免费   281篇
耳鼻咽喉   127篇
儿科学   486篇
妇产科学   249篇
基础医学   386篇
口腔科学   19篇
临床医学   3090篇
内科学   4504篇
皮肤病学   37篇
神经病学   216篇
特种医学   628篇
外国民族医学   1篇
外科学   1897篇
综合类   1628篇
预防医学   649篇
眼科学   51篇
药学   581篇
  10篇
中国医学   85篇
肿瘤学   213篇
  2024年   9篇
  2023年   230篇
  2022年   195篇
  2021年   476篇
  2020年   515篇
  2019年   486篇
  2018年   448篇
  2017年   494篇
  2016年   500篇
  2015年   539篇
  2014年   1013篇
  2013年   961篇
  2012年   897篇
  2011年   864篇
  2010年   706篇
  2009年   661篇
  2008年   593篇
  2007年   589篇
  2006年   553篇
  2005年   476篇
  2004年   469篇
  2003年   374篇
  2002年   334篇
  2001年   288篇
  2000年   242篇
  1999年   239篇
  1998年   234篇
  1997年   185篇
  1996年   137篇
  1995年   117篇
  1994年   151篇
  1993年   133篇
  1992年   113篇
  1991年   84篇
  1990年   57篇
  1989年   86篇
  1988年   71篇
  1987年   45篇
  1986年   40篇
  1985年   52篇
  1984年   39篇
  1983年   22篇
  1982年   29篇
  1981年   30篇
  1980年   19篇
  1979年   16篇
  1978年   14篇
  1977年   11篇
  1976年   11篇
  1973年   4篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
3.
4.
BackgroundOur meta-analysis from 2013 showed that inserting a catheter intrathecally after an observed accidental dural puncture can reduce the need for epidural blood patch in labouring women requesting epidural analgesia. We updated our conventional meta-analysis and added a trial-sequential analysis (TSA).MethodsA systematic literature search was conducted to identify studies that compared inserting the catheter intrathecally with an epidural catheter re-site or with no intervention. The extracted data were pooled and the risk ratio (RR) and 95% confidence interval (95%CI) for the incidence of post-dural puncture headache (PDPH) was calculated, using the random effects model. A contour-enhanced funnel plot was constructed. A TSA was performed and the cumulative Z score, monitoring and futility boundaries were constructed.ResultsOur search identified 13 studies, reporting on 1653 patients, with a low risk of bias. The RR for the incidence of PDPH was 0.82 (95%CI 0.71 to 0.95) and the RR for the need for epidural blood patch was 0.62 (95%CI 0.49 to 0.79); heterogeneity of both analyses was high. The TSA showed that the monitoring or futility boundaries were not crossed, indicating insufficient data to exclude a type I error of statistical analysis. Contour-enhanced funnel plots were symmetric, suggesting no publication bias.ConclusionsConventional meta-analyses showed for the first time that intrathecal catheterisation can reduce the incidence of PDPH. However, TSA did not corroborate this finding. Despite increasing use in clinical practice there is no firm evidence on which to base a definite conclusion.  相似文献   
5.
Purpose: To describe how central venous access devices (CVADs) are utilized for ambulatory oncology patients and to evaluate the rate of complications. Method: Single institution retrospective study of oncology patients with CVADs who received systemic treatment at the Walker Family Cancer Centre (WFCC) between 1 January and 31 December 2018. Results: A total of 480 CVADS were placed in 305 patients, of which 408 (85%) were peripherally inserted central catheters (PICCs) and 72 (15%) were implanted vascular access devices (PORTs). The incidence of early and late complications was 9% and 24%, respectively. For the entire cohort, the rate of venous thromboembolism (VTE) was 16%, of which 9% were CVAD-related thrombosis (CRTs) and 7% were distant VTE. The CRT rates were similar for PICCs and PORTs (9% vs. 7%). A total of 6% of CVADs were complicated by infection (i.e., localized infections and bacteremia), with a total infection rate of 0.43 and 0.26 per 1000 indwelling days for PICCs and PORTs, respectively. The incidence of central line associated bloodstream infections (CLABSI) was greater for PICCs than PORTs, at a rate of 0.22 compared with 0.08 per 1000 indwelling days, respectively. The premature catheter removal rate was 26% for PICCs and 18% for PORTs. PORTs required more additional hospital visits. Conclusions: PICCs were utilized more frequently than PORTs and had a higher rate of premature removal. The rates of VTE and CRT were similar for both CVAD types. PORTs had a lower rate of infection per 1000 indwelling days. However, the management of PORT related complications required more visits to the hospital and oncology clinic.  相似文献   
6.
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   
7.
S. G. Brearley  S. Varey  A. Krige 《Anaesthesia》2023,78(10):1249-1255
Adequate postoperative analgesia is a key element of enhanced recovery programmes. Thoracic epidural analgesia is associated with superior postoperative analgesia but can lead to complications. Rectus sheath catheter analgesia may provide an alternative. In a nested qualitative study (within a two-year randomised controlled trial) focussing on the acceptability, expectations and experiences of receiving the interventions, participants (n = 20) were interviewed 4 weeks post-intervention using a grounded theory approach. Constant comparative analysis, with patient and public involvement, enabled emerging findings to be pursued through subsequent data collection. We found no notable differences regarding postoperative acceptability or the experience of pain management. Pre-operatively, however, thoracic epidural analgesia was a source of anticipatory fear and anxiety. Both interventions resulted in some experienced adverse events (proportionately more with thoracic epidural analgesia). Participants had negative experiences of the insertion of thoracic epidural analgesia; others receiving the rectus sheath catheter lacked confidence in staff members' ability to manage the local anaesthetic infusion pump. The anticipation of the technique of thoracic epidural analgesia, and concerns about its impact on mobility, represented an additional, unpleasant experience for patients already managing an illness experience, anticipating a life-changing operation and dealing with concerns about the future. The anticipation of rectus sheath catheter analgesia was not associated with such anxieties. Patients' experiences start far earlier than the experience of the intervention itself through anticipatory anxieties and fears about receiving a technique and its potential implications. Complex pain packages can take on greater meaning than their actual efficacy in relieving postoperative pain. Future research into patient acceptability and experience should not focus solely on efficacy of pain relief but should include anticipatory fears, anxieties and experiences.  相似文献   
8.
9.
Patients with active cancer are at an increased risk of arterial and venous thromboembolism (VTE) and bleeding events. Historically, in patients with cancer, low molecular weight heparins have been preferred for treatment of VTE, whereas warfarin has been the standard anticoagulant for stroke prevention in patients with atrial fibrillation (AF). More recently, direct oral anticoagulants (DOACs) have been demonstrated to reduce the risk of venous and arterial thromboembolism in large randomized clinical trials of patients with VTE and AF, respectively, thus providing an attractive oral dosing option that does not require routine laboratory monitoring. In this review, we summarize available clinical trial data and guideline recommendations, and outline a practical approach to anticoagulation management of VTE and AF in cancer.  相似文献   
10.
Stellate ganglion (SG) modification has been investigated for arrhythmia treatment. In this study, transesophageal SG imaging and intervention were explored using a homemade 30F integrated focused ultrasonic catheter in healthy mongrel canines in vivo. Anatomic details of SGs were ultrasonically imaged and evaluated. SG had a heterogeneous echoic structure and characteristic profiles sketched by hyper-echoic outlines in an ultrasonogram. Left SGs in the experimental group were successfully ablated through the esophagus under ultrasonic guidance provided by the catheter itself. Two weeks after the ablation, the QT and QTc of the experimental group decreased compared with those of the sham group and at baseline (both p values < 0.001). Histologic examination revealed that left SGs were destroyed. No major complications were observed. This approach may be further explored as a method for ganglia remodeling evaluation and as a strategy of ganglia modification for arrhythmia and for other diseases.  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