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   1408697篇
  免费   105889篇
  国内免费   2448篇
耳鼻咽喉   20525篇
儿科学   47997篇
妇产科学   38163篇
基础医学   200144篇
口腔科学   38627篇
临床医学   119818篇
内科学   289933篇
皮肤病学   32366篇
神经病学   111290篇
特种医学   54132篇
外国民族医学   661篇
外科学   211959篇
综合类   27932篇
现状与发展   1篇
一般理论   413篇
预防医学   108879篇
眼科学   30750篇
药学   104254篇
  2篇
中国医学   3239篇
肿瘤学   75949篇
  2021年   11857篇
  2019年   12662篇
  2018年   17915篇
  2017年   12846篇
  2016年   13707篇
  2015年   15522篇
  2014年   21526篇
  2013年   32359篇
  2012年   45517篇
  2011年   48221篇
  2010年   28180篇
  2009年   26103篇
  2008年   44416篇
  2007年   47378篇
  2006年   47063篇
  2005年   45935篇
  2004年   44274篇
  2003年   42690篇
  2002年   41522篇
  2001年   67270篇
  2000年   70241篇
  1999年   59340篇
  1998年   15893篇
  1997年   14353篇
  1996年   14671篇
  1995年   13875篇
  1994年   13105篇
  1993年   12066篇
  1992年   45716篇
  1991年   44462篇
  1990年   43123篇
  1989年   40872篇
  1988年   37543篇
  1987年   36840篇
  1986年   34221篇
  1985年   32817篇
  1984年   24502篇
  1983年   20579篇
  1982年   11922篇
  1981年   10892篇
  1979年   21690篇
  1978年   15071篇
  1977年   12727篇
  1976年   11914篇
  1975年   12890篇
  1974年   14997篇
  1973年   14453篇
  1972年   13234篇
  1971年   12041篇
  1970年   11326篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
91.
Background Immune checkpoint blockers (ICBs) activate CD8+ T cells, eliciting both anti-cancer activity and immune-related adverse events (irAEs). The relationship of irAEs with baseline parameters and clinical outcome is unclear.Methods Retrospective evaluation of irAEs on survival was performed across primary (N = 144) and secondary (N = 211) independent cohorts of patients with metastatic melanoma receiving single agent (pembrolizumab/nivolumab—sICB) or combination (nivolumab and ipilimumab—cICB) checkpoint blockade. RNA from pre-treatment and post-treatment CD8+ T cells was sequenced and differential gene expression according to irAE development assessed.Results 58.3% of patients developed early irAEs and this was associated with longer progression-free (PFS) and overall survival (OS) across both cohorts (log-rank test, OS: P < 0.0001). Median survival for patients without irAEs was 16.6 months (95% CI: 10.9–33.4) versus not-reached (P = 2.8 × 10−6). Pre-treatment monocyte and neutrophil counts, but not BMI, were additional predictors of clinical outcome. Differential expression of numerous gene pathway members was observed in CD8+ T cells according to irAE development, and patients not developing irAEs demonstrating upregulated CXCR1 pre- and post-treatment.Conclusions Early irAE development post-ICB is associated with favourable survival in MM. Development of irAEs is coupled to expression of numerous gene pathways, suggesting irAE development in-part reflects baseline immune activation.Subject terms: Immunotherapy, Melanoma  相似文献   
92.
93.
94.
Jahn  P. 《Der Onkologe》2020,26(11):1040-1046
Die Onkologie - Die Pflegepersonaluntergrenzen als rote Linien zur Abgrenzung einer gefährlichen Pflegepraxis sind nicht geeignet, die dringend benötigte Trendwende einzuleiten und...  相似文献   
95.
96.
97.
98.
99.

Background

Arterial vascular anomalies in patients undergoing kidney transplantation (KT) are correlated with a higher incidence of early surgical complications, potentially causing graft loss. Arterial reconstruction allows patients to overcome these surgical challenges, thus minimizing the risk of poor outcomes. The aim of the present study is to retrospectively investigate the safety and effectiveness of the multiple arterial reconstruction technique with a Teflon patch in case of an unavailable aortic patch: to do so, surgical complications, graft function, and patient survival were evaluated.

Methods

During the period January 2009 to August 2016, 202 adult deceased-donor KTs were performed at our center. Group A (n = 27; reconstruction of multiple arteries) and Group B (n = 175; control group) were compared.

Results

No differences were observed between the 2 groups in terms of early postoperative course, with no vascular complication observed in Group A. No vascular patch infections were reported, nor longer cold ischemia time rates. Similarly, long-term survival rates were similar between the 2 groups.

Conclusions

The Teflon-patch arterial reconstruction technique appears to be safe and effective, with an acceptable balance of benefits and potential risks of using a prosthetic material. Studies based on larger series are needed to further validate this approach.  相似文献   
100.

Objective

Arch obstruction after the Norwood procedure is common and contributes to mortality. We determined the prevalence, associated factors, and practice variability of arch reintervention and assessed whether arch reintervention is associated with mortality.

Methods

From 2005 to 2017, 593 neonates in the Congenital Heart Surgeons' Society Critical Left Heart Obstruction cohort underwent a Norwood procedure. Median follow-up was 3.7 years. Multivariable parametric models, including a modulated renewal analysis, were performed.

Results

Of the 593 neonates, 146 (25%) underwent 218 reinterventions for arch obstruction after the Norwood procedure: catheter-based (n = 168) or surgical (n = 50) at a median age of 4.3 months (quartile 1-quartile 3, 2.6-5.7). Interdigitation of the distal aortic anastomosis was protective against arch reintervention. Development of ≥ moderate tricuspid valve regurgitation and right ventricular dysfunction at any point was associated with arch reintervention. Nonsignificant variables for arch reintervention included shunt type and preoperative aortic measurements. Surgical arch reintervention was protective against arch reintervention, but transcatheter reintervention was associated with increased reintervention. Arch reintervention was not associated with increased mortality. There was wide institutional variation in incidence of arch reintervention (range, 0-40 reinterventions per 100 years patient follow-up) and in preintervention gradient (range, 0-64 mm Hg).

Conclusions

Interdigitation of the distal aortic anastomosis during the Norwood procedure decreased the risk of arch reintervention. Surgical arch reintervention is more definitive than transcatheter. Arch reintervention after the Norwood procedure is not associated with increased mortality. Serial surveillance for arch obstruction, integrated with changes in right ventricular function and tricuspid valve regurgitation, is recommended after the Norwood procedure to improve outcomes.  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