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   361篇
  免费   11篇
  国内免费   7篇
儿科学   3篇
妇产科学   4篇
基础医学   36篇
口腔科学   5篇
临床医学   36篇
内科学   85篇
皮肤病学   5篇
神经病学   8篇
特种医学   122篇
外科学   31篇
综合类   2篇
预防医学   13篇
眼科学   4篇
药学   15篇
肿瘤学   10篇
  2022年   2篇
  2020年   2篇
  2019年   2篇
  2018年   6篇
  2016年   4篇
  2015年   5篇
  2014年   4篇
  2013年   10篇
  2012年   6篇
  2011年   8篇
  2010年   7篇
  2009年   7篇
  2008年   5篇
  2007年   18篇
  2006年   17篇
  2005年   5篇
  2004年   6篇
  2003年   3篇
  2002年   4篇
  2001年   5篇
  2000年   2篇
  1999年   3篇
  1998年   13篇
  1997年   18篇
  1996年   15篇
  1995年   12篇
  1994年   17篇
  1993年   8篇
  1992年   3篇
  1991年   8篇
  1990年   4篇
  1989年   19篇
  1988年   13篇
  1987年   10篇
  1986年   17篇
  1985年   9篇
  1984年   10篇
  1983年   2篇
  1982年   9篇
  1981年   4篇
  1980年   6篇
  1979年   4篇
  1978年   6篇
  1977年   7篇
  1976年   8篇
  1975年   9篇
  1974年   2篇
  1971年   4篇
  1970年   2篇
  1965年   2篇
排序方式: 共有379条查询结果,搜索用时 0 毫秒
31.
The authors demonstrate that it is possible to obtain highly T1-weighted images of the abdomen using a suspended respiration partial saturation (SRPS) method in a breath-holding interval. T2*-weighted images, which reflect tissue T2 as well as variations in the static magnetic field, can also be rapidly obtained. The authors studied five healthy subjects and 19 patients with a variety of liver abnormalities, including benign and malignant hepatic neoplasms, fatty liver infiltration, ascites, and hematoma. On T1-weighted multisection acquisitions, the entire liver can be screened for mass lesions in a single 20-second breath-holding interval. Phase-contrast SRPS images are sensitive to fatty infiltration of the liver. SRPS images are more sensitive to variations in magnetic susceptibility than spin-echo images are, which has been proved to be of value in the detection of hemorrhage. With continued pulse sequence development and clinical study, this method has the potential to become the method of choice for evaluation of the upper abdomen.  相似文献   
32.
As cardiac transplantation has become widely available, computed tomography (CT) of the chest has played a useful role in the examination of patients after heart transplantation. To determine anatomic features related to the procedure, the authors evaluated 59 scans in 46 patients who had undergone orthotopic cardiac transplantation. Aortic anastomosis (seen in 98% of scans) and altered spacing between the great vessels (83%) proved to be the most common and most reliable findings. Other features including atrial anastomosis, high main pulmonary artery segment, remnant superior vena cava, and cardiac reorientation were also seen. Accurate interpretation of adenopathy, mediastinal abscess, and pericardial effusion will be enhanced in these patients through a better understanding of the cardiovascular-pericardial complex, which is afforded by CT.  相似文献   
33.
34.
Urinary tract infections, renal abscess formation and acute renal failure (ARF) after salmonella infection are rarely reported in children. We present a previously healthy teenager who developed ARF with renal abscess formation after salmonella infection, in whom we believe that acute salmonella pyelonephritis was the main causative factor for ARF and not dehydration, shock or rhabdomyolysis, which have already been described in the literature. With prolonged antibiotic treatment and adequate hydration, the boy’s condition improved, but chronic kidney disease was unfortunately inevitable. Conclusion: Salmonella pyelonephritis has, according to our knowledge, not yet been described to be the main causative factor of ARF in previously healthy children, as was the case in our patient. Long‐term antibiotic treatment of at least 6 weeks is probably a must in such patients, even though chronic kidney disease could not have been prevented.  相似文献   
35.
目的:研究证实,在众多生长因子中,肝细胞生长因子无论在体外还是体内都可以激活静止状态的肌卫星细胞,修复受损肌肉。采用脂多糖刺激体外培养的骨骼肌卫星细胞,观察肌卫星细胞产生肝细胞生长因子以及肌卫星细胞增殖分化的变化。方法:实验于2006-07/2007-05在华中科技大学同济医学院同济医院创伤外科实验室完成。①实验材料:健康SD成年雄性大鼠,体质量150~200g,由华中科技大学同济医学院实验动物中心提供。实验过程中对动物处置符合实验动物伦理学标准。②实验方法:分离SD大鼠后肢部分股四头肌肉进行骨骼肌卫星细胞的培养。取第2代细胞爬片,待细胞增殖到80%密度时,丙酮固定细胞,常规处理后进行α-sarcometricactin细胞免疫化学染色鉴定,以成纤维细胞作为阴性对照。取第3代骨骼肌卫星细胞,应用0,5,10,20mg/L脂多糖刺激体外培养的大鼠骨骼肌卫星细胞,采用ELISA方法测细胞培养液中的肝细胞生长因子的浓度。取第4代骨骼肌卫星细胞,用含体积分数为0.10胎牛血清的培养基配制成单个细胞悬液,调整浓度为5×107L-1,分成两组,一组加入10mg/L脂多糖,另一组不加任何干预。采用噻唑蓝(MTT)法测定卫星细胞的增殖率。结果:①以未经脂多糖处理的无血清培养基培养的肌肉卫星细胞培养液为对照,将对照组和5,10,20mg/L脂多糖处理组比较,各实验组肝细胞生长因子浓度明显高于对照组(P<0.05)。②5,10,20mg/L脂多糖刺激骨骼肌卫星细胞分泌的肝细胞生长因子水平差异无显著性。③肝细胞生长因子在脂多糖刺激后36h分泌浓度最高。④脂多糖刺激肌卫星细胞的增殖分化明显高于未经刺激的肌卫星细胞。结论:①脂多糖可诱导骨骼肌卫星细胞自分泌肝细胞生长因子。②不同质量浓度脂多糖培养基中肝细胞生长因子水平差异无统计学意义。③脂多糖具有促进骨骼肌卫星细胞增殖分化的效应。  相似文献   
36.
BACKGROUND: Expensive devices have been developed for the collection and transfusion of blood salvaged after hip or knee arthroplasty. STUDY DESIGN AND METHODS: The volume of salvaged red cells was measured for the first 6 hours after operation. This volume was compared to total red cell loss during hospitalization and to the volume of allogeneic red cells transfused. RESULTS: Mean postoperative red cell loss in 31 patients following hip replacement was 55 +/− 29 mL and that in 20 patients following knee replacement was 121 +/− 50 mL. The 6-hour wound drainage represented 8.7 and 16.8 percent of overall red cell loss during hospitalization for hip and knee replacement, respectively. The transfusion of postoperatively salvaged red cells would have supplanted transfusion of less than one-third of a unit of allogenic blood after hip replacement and two-thirds of a unit after knee replacement. Only three patients (5.9%) lost red cell volume in the drainage equivalent to or in excess of 1 unit of red cells (180 mL). The volume of red cells salvaged postoperatively bore no relationship to perioperative red cell losses as a whole. CONCLUSION: The relatively small red cell loss in the postoperative period in most arthroplasty patients does not appear to justify the routine use of this technique for the recovery of autologous blood.  相似文献   
37.
38.
39.
40.
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