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   850篇
  免费   47篇
  国内免费   35篇
耳鼻咽喉   5篇
儿科学   71篇
妇产科学   6篇
基础医学   83篇
口腔科学   28篇
临床医学   102篇
内科学   171篇
皮肤病学   24篇
神经病学   25篇
特种医学   186篇
外科学   42篇
综合类   40篇
预防医学   44篇
眼科学   17篇
药学   53篇
中国医学   1篇
肿瘤学   34篇
  2021年   8篇
  2019年   8篇
  2018年   16篇
  2017年   12篇
  2016年   10篇
  2015年   18篇
  2014年   11篇
  2013年   26篇
  2012年   14篇
  2011年   8篇
  2010年   41篇
  2009年   37篇
  2008年   11篇
  2007年   19篇
  2006年   15篇
  2005年   33篇
  2004年   11篇
  2002年   8篇
  2001年   12篇
  2000年   8篇
  1999年   17篇
  1998年   47篇
  1997年   47篇
  1996年   50篇
  1995年   35篇
  1994年   42篇
  1993年   39篇
  1992年   12篇
  1991年   16篇
  1990年   9篇
  1989年   24篇
  1988年   46篇
  1987年   21篇
  1986年   15篇
  1985年   30篇
  1984年   9篇
  1982年   7篇
  1981年   11篇
  1980年   9篇
  1979年   6篇
  1978年   5篇
  1977年   7篇
  1976年   12篇
  1975年   4篇
  1959年   5篇
  1958年   15篇
  1957年   7篇
  1956年   12篇
  1955年   10篇
  1954年   8篇
排序方式: 共有932条查询结果,搜索用时 171 毫秒
61.
引用违法传递概念设计合成了11个C-末端含氧代赖氨酸二肽,进行抗深部致病菌-白念珠菌活性试验,体外实验结果显示极强的抑菌活性,MIC在12.5~0.8μg/disk之间,较母体氧化赖氨酸大50~135倍(克分子比。  相似文献   
62.
63.
Sera from thirteen patients with tropical eosinophilia had IgE levels of 7000–56,000 μ/ml, unrelated to the level of eosinophilia or the duration of symptoms. They are the richest source of polyclonal IgE we have encountered.  相似文献   
64.
65.
66.
As an alternative to performing interventional radiology on inpatients under the care of internists and surgeons, the authors have established a cardiovascular radiology admitting service for well-screened, elective patients. The patients are admitted under the care of a cardiovascular radiology fellow and a staff physician. From April 1982 to December 1983, 133 patients were admitted to the service. Patients are cared for in a surgical ward or in an intermediate unit, as determined by the clinical situation. Advantages of this approach include a broader patient referral base, improved rapport with clinical colleagues and patients, improved follow-up data, and rapid evaluation and treatment, resulting in short hospital stays. The major disadvantages involve the commitment of time and staff necessary to provide quality care. The concept of the interventional radiologist in the role of admitting physician has important implications in terms of negotiations for additional financial compensation, commensurate with the skill and time required for performing these procedures and caring for the patient.  相似文献   
67.
68.
基因芯片技术是最近发展起来的新兴分子生物学技术,它的并行处理特点使大规模研究脑损伤后的基因改变成为切实可能。本文综述了新近用基因芯片技术在脑损伤后基因表达时序性改变及基因表达谱分析等研究中的应用。  相似文献   
69.
Kinnison  ML; Powe  NR; Steinberg  EP 《Radiology》1989,170(2):381-389
The authors reviewed 100 randomized controlled trials (RCTs) conducted in humans to compare safety or efficacy of new low-osmolality contrast media (LOM) with that of high-osmolality contrast media (HOM). Findings of the 43 RCTs judged to be of the highest quality suggest that the efficacy of LOM in imaging is equal or superior to that of HOM for all routes of administration. Heat sensation occurred less often with LOM for all routes and pain occurred less often with LOM for intraarterial routes. No differences were seen in nephrotoxicity or in frequency of nausea, vomiting, urticaria, bronchospasm, laboratory test abnormalities, or neurologic events. Greater cardiovascular changes were seen with HOM, including increased or decreased heart rate, increased left ventricular end-diastolic pressure, decreased systolic pressure, and QT prolongation, depending on route of administration. To demonstrate whether a reduction in clinically significant adverse outcomes truly occurs with LOM, trials will need to enlist larger numbers of patients and employ appropriate outcome measures. Future trials should stratify patients according to their risk of adverse reactions to provide better information about benefits of LOM in low- versus high-risk patients.  相似文献   
70.
Isthmic spondylolysis of the lumbar spine: MR imaging at 1.5 T   总被引:4,自引:0,他引:4  
The appearance on magnetic resonance (MR) images of the normal pars interarticularis in 13 patients was reviewed and contrasted with that of the pars in eight patients with spondylolysis. The pars defect usually had an intermediate signal intensity with all pulse sequences; however, this intensity was somewhat variable depending on the exact ratio of cartilage, fat, and fluid within each bone defect. The pars defect was best seen with spin-echo 600/20 (repetition time msec/echo time msec) images. In three cases, out-of-phase images showed the spondylolysis best, because of extension of fat to the borders of the defect. The sagittal view allowed one to separate spondylolysis from the joint space of posterior facets since the orientation of the defects is perpendicular to the facets; thus, a common pitfall encountered with cross-sectional axial imaging techniques is avoided. MR imaging poorly delineated bone fragments around the defect, which may produce nerve root impingement, but revealed other numerous complications that occur with spondylolysis, including spondylolisthesis and herniation of the disk above.  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