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   30898篇
  免费   2694篇
  国内免费   1378篇
耳鼻咽喉   134篇
儿科学   388篇
妇产科学   1133篇
基础医学   2898篇
口腔科学   327篇
临床医学   3191篇
内科学   4786篇
皮肤病学   422篇
神经病学   1689篇
特种医学   1256篇
外国民族医学   11篇
外科学   4615篇
综合类   5789篇
现状与发展   7篇
预防医学   765篇
眼科学   1234篇
药学   2951篇
  18篇
中国医学   1812篇
肿瘤学   1544篇
  2024年   40篇
  2023年   479篇
  2022年   614篇
  2021年   1109篇
  2020年   1187篇
  2019年   1064篇
  2018年   1012篇
  2017年   1062篇
  2016年   1105篇
  2015年   1218篇
  2014年   1995篇
  2013年   2216篇
  2012年   1810篇
  2011年   2008篇
  2010年   1725篇
  2009年   1600篇
  2008年   1674篇
  2007年   1710篇
  2006年   1631篇
  2005年   1438篇
  2004年   1236篇
  2003年   1060篇
  2002年   906篇
  2001年   740篇
  2000年   642篇
  1999年   492篇
  1998年   415篇
  1997年   355篇
  1996年   291篇
  1995年   285篇
  1994年   223篇
  1993年   184篇
  1992年   184篇
  1991年   180篇
  1990年   119篇
  1989年   108篇
  1988年   102篇
  1987年   103篇
  1986年   81篇
  1985年   112篇
  1984年   80篇
  1983年   52篇
  1982年   59篇
  1981年   77篇
  1980年   44篇
  1979年   39篇
  1978年   31篇
  1977年   21篇
  1976年   15篇
  1975年   13篇
排序方式: 共有10000条查询结果,搜索用时 203 毫秒
1.
2.
3.
Sinus venosus atrial septal defect (SV‐ASD) usually coexists with partial anomalous pulmonary vein connection (PAPVC). It is a difficult diagnosis in transthoracic echocardiography (TTE) due to eccentric position of defects. We present a rare case of atypical anatomical variation in PAPVC, which was never described before. Two right pulmonary veins drained into superior vena cava, which overrode SV‐ASD and interatrial septum, a third pulmonary vein into the right atrium. Complete diagnosis could not be set after TTE, nor transesophageal echocardiography, whereas angio‐CT was finally conclusive. This diagnostic approach allowed the surgical planning.  相似文献   
4.
5.
Central illustration: cumulative major adverse cardiac events (MACE) and bioresorbable vascular scaffold (BVS) thrombosis rates after 1, 2, 3, 4 and 5 years.
  相似文献   
6.
7.
由于骨盆的特殊结构,其内侧的血管网损伤导致不可压迫性出血。即使创伤中心和救治体系的建设,以及损害控制技术等发展,病死率仍然高达30%~60%。损害控制性复苏、骨盆带、外固定支架、复苏性腹主动脉内球囊阻断(REBOA)、动脉栓塞和腹膜外填塞等技术不断发展,部分已经得到普及,但迄今仍没有公认的确定性止血流程。我国正在普遍建设创伤中心,亟待制订适合我国的骨盆骨折大出血患者的救治流程,以提高救治成功率。本文阐述控制骨盆骨折大出血的外科技术和流程进展供同道参考。  相似文献   
8.
9.
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   
10.
Pulmonary hypertension of the newborn (PHN) constitutes a critical condition with severe cardiovascular and neurological consequences. One of its main causes is hypoxia during gestation, and thus, it is a public health concern in populations living above 2500 m. Although some mechanisms are recognized, the pathophysiological facts that lead to PHN are not fully understood, which explains the lack of an effective treatment. Oxidative stress is one of the proposed mechanisms inducing pulmonary vascular dysfunction and PHN. Therefore, we assessed whether melatonin, a potent antioxidant, improves pulmonary vascular function. Twelve newborn sheep were gestated, born, and raised at 3600 meters. At 3 days old, lambs were catheterized and daily cardiovascular measurements were recorded. Lambs were divided into two groups, one received daily vehicle as control and another received daily melatonin (1 mg/kg/d), for 8 days. At 11 days old, lung tissue and small pulmonary arteries (SPA) were collected. Melatonin decreased pulmonary pressure and resistance for the first 3 days of treatment. Further, melatonin significantly improved the vasodilator function of SPA, enhancing the endothelial‐ and muscular‐dependent pathways. This was associated with an enhanced nitric oxide‐dependent and nitric oxide independent vasodilator components and with increased nitric oxide bioavailability in lung tissue. Further, melatonin reduced the pulmonary oxidative stress markers and increased enzymatic and nonenzymatic antioxidant capacity. Finally, these effects were associated with an increase of lumen diameter and a mild decrease in the wall of the pulmonary arteries. These outcomes support the use of melatonin as an adjuvant in the treatment for PHN.  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