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   705933篇
  免费   48904篇
  国内免费   1305篇
耳鼻咽喉   9166篇
儿科学   23267篇
妇产科学   17603篇
基础医学   110391篇
口腔科学   19962篇
临床医学   63764篇
内科学   134383篇
皮肤病学   16159篇
神经病学   49436篇
特种医学   25741篇
外国民族医学   76篇
外科学   104530篇
综合类   14818篇
现状与发展   2篇
一般理论   160篇
预防医学   51386篇
眼科学   16318篇
药学   53949篇
  3篇
中国医学   2359篇
肿瘤学   42669篇
  2021年   5443篇
  2018年   7861篇
  2017年   6110篇
  2016年   6828篇
  2015年   7558篇
  2014年   10264篇
  2013年   15380篇
  2012年   20493篇
  2011年   21488篇
  2010年   12726篇
  2009年   11932篇
  2008年   19995篇
  2007年   21517篇
  2006年   21900篇
  2005年   20449篇
  2004年   19993篇
  2003年   18950篇
  2002年   18463篇
  2001年   36333篇
  2000年   36903篇
  1999年   30381篇
  1998年   7877篇
  1997年   6663篇
  1996年   6970篇
  1995年   6627篇
  1994年   6096篇
  1993年   5589篇
  1992年   22968篇
  1991年   22925篇
  1990年   22310篇
  1989年   22078篇
  1988年   20036篇
  1987年   19420篇
  1986年   18470篇
  1985年   17307篇
  1984年   12697篇
  1983年   10743篇
  1982年   5921篇
  1979年   11518篇
  1978年   8128篇
  1977年   6832篇
  1976年   6594篇
  1975年   7268篇
  1974年   8498篇
  1973年   8141篇
  1972年   7658篇
  1971年   7127篇
  1970年   6877篇
  1969年   6306篇
  1968年   5780篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
We report a 40-year-old man with rheumatic heart disease who presented with abdominal pain for three weeks and hematemesis for 24 hours. CT scan showed a large splenic artery aneurysm without evidence of pancreatitis. Mycotic aneurysm due to infective endocarditis was considered and confirmed by echocardiogram, which showed aortic and mitral valve regurgitation and vegetations. He was managed successfully with coil embolization of the aneurysm and antibiotics.  相似文献   
993.
994.
Phaeohyphomycosis is a disease caused by dematiaceous fungi. Here, the first culture-proven case of mediastinal mass due to Fonsecaea pedrosoi is reported. The patient was a 40-yr-old male who had presented with history of dyspnoea and dysphagia. Computed tomography of the chest disclosed a mediastinal mass. Cultures of a specimen from the mediastinum grew Fonsecaea pedrosoi. The patient received amphotericin B and itraconazole and showed a remarkable recovery. Repeat computed tomography revealed a reduction in the mediastinal mass. The case highlights the need for a high degree of clinical suspicion and appropriate histopathological and mycological examination of clinical specimens.  相似文献   
995.
Pulmonary diffusing capacity for carbon monoxide (DLCO) and pulmonary capillary blood flow (Qp) were measured on exercise in patients with a low DLCO with the aim of predicting, from the overall DL/Qp ratio, diffusion limitation for oxygen and relating it to the fall in arterial oxygen saturation actually observed. Five patients with cryptogenic fibrosing alveolitis (DLCO ranging from 20-54% predicted normal) exercised for 5 min at a work load equal to 60% of their maximum (45 to 90 watts). At 5 min (and previously at rest) they rebreathed rapidly for 15 sec from a 1.0 L bag containing helium (He), sulphur hexafluoride (SF6) and freon-22, 30% oxygen in argon and less than 1 ppm 11C-labelled carbon monoxide. Pulmonary capillary blood flow (Qp) and diffusing capacity (DLCO) were measured from flow-weighted breath-by-breath concentrations of freon-22 and 11CO, after correction for gas mixing delays (using He and SF6). Oxygen saturation (SaO2) (ear oximetry), MO2 and MCO2 and cardiac frequency were measured. PAO2 (ideal) was derived and mixed venous O2 saturation and content were calculated (Fick); PaO2 and PVO2 were derived from standard dissociation curves. For comparison, DLCO and Qp were measured in a similar fashion in five normal subjects exercising at 60 watts. Mean DLCO in patients with fibrosis was 9.62 (SD 2.88) ml.min-1, mm Hg-1 on exercise and mean Qp was 10.48 (SD 1.79) L.min-1 giving mean DLCO/Q ratios of 0.92 (SD 0.28). At 60 watts mean DLCO/Qp in normal subjects was 2.54 (SD 0.3), 2.76-times greater than in patients. SaO2% fell in patients by 3-15% on exercise. Predictions of alveolar-end capillary PO2 gradients from these overall DL/Q gradients showed that diffusion limitation accounted for 99% of the alveolar-arterial PO2 gradient on exercise in fibrosing alveolitis. Hughes (1991 Respir. Physiol. 83:167-178) [corrected] suggests that this simple approach overestimates the contribution of diffusion limitation by about 30%.  相似文献   
996.
Plans to send humans to Mars dictate revision of the whole crew medical support system. Autonomy of the mission will extend crew responsibilities for all dimensions of medical support. The article compares and contrasts medical support of crews on orbital and interplanetary missions, and considers the place and functionality of medical informational technologies in a mission to Mars.  相似文献   
997.
998.
Immunization of BALB/c mice with natural purified HIV antigen, fusion of spleen cells with myeloma cells and subsequent selection of hybrid clones using recombinant gag antigen of HIV gave hybridomas producing monoclonal antibodies (MCA) to HIV. The immune blotting method demonstrated that 3 clones interacted with protein p24 and 4 clones with protein p17 of HIV. Competitive EIA led to a conclusion that the resulting MCA detected at least 3 antigenic determinants in proteins, products of gag gene of HIV. The potentials of using these MCA for the detection of viral antigen in HIV-infected continuous cell lines were demonstrated.  相似文献   
999.
1000.
Improved survival rates for patients with major burn injuries and the consistent finding of significant long-term psychologic disability among survivors of burn trauma call for a redefinition of the role of the psychiatric consultant in the care of patients with burns. In addition to the traditional functions of diagnosis and treatment of discrete psychiatric disorders in patients with burns, this expanded role includes assisting the patient's normal process of psychologic adaptation after injury, assessing and managing burn pain, and facilitating communication among all members of the burn team. The functions of the psychiatrist are most effectively carried out when the psychiatrist is able to participate on a regular basis in the care of every patient as a member of the burn team.  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