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   973篇
  免费   29篇
  国内免费   75篇
耳鼻咽喉   1篇
儿科学   46篇
妇产科学   19篇
基础医学   71篇
口腔科学   20篇
临床医学   130篇
内科学   237篇
皮肤病学   34篇
神经病学   35篇
特种医学   258篇
外科学   44篇
综合类   28篇
预防医学   45篇
眼科学   22篇
药学   44篇
中国医学   3篇
肿瘤学   40篇
  2023年   5篇
  2020年   4篇
  2019年   8篇
  2018年   7篇
  2017年   5篇
  2016年   11篇
  2015年   13篇
  2014年   15篇
  2013年   14篇
  2012年   13篇
  2011年   16篇
  2010年   31篇
  2009年   49篇
  2008年   17篇
  2007年   47篇
  2006年   24篇
  2005年   21篇
  2004年   10篇
  2003年   13篇
  2002年   12篇
  2001年   19篇
  2000年   20篇
  1999年   10篇
  1998年   82篇
  1997年   70篇
  1996年   59篇
  1995年   51篇
  1994年   43篇
  1993年   44篇
  1992年   22篇
  1991年   15篇
  1990年   25篇
  1989年   35篇
  1988年   34篇
  1987年   26篇
  1986年   24篇
  1985年   25篇
  1984年   18篇
  1983年   11篇
  1982年   17篇
  1981年   9篇
  1980年   13篇
  1979年   5篇
  1978年   6篇
  1977年   17篇
  1976年   13篇
  1975年   14篇
  1972年   2篇
  1958年   2篇
  1900年   2篇
排序方式: 共有1077条查询结果,搜索用时 702 毫秒
71.
Postembolic colonic infarction   总被引:12,自引:0,他引:12  
  相似文献   
72.
73.
74.
BACKGROUND: There may be difficulties in the use of self report measurements in patients with cognitive impairment or serious mood disturbances which interfere with reliable self assessment, as may be the case in multiple sclerosis (MS). In such cases proxies may provide valuable information. However, before using any questionnaires in a proxy sample, the questionnaire should be evaluated for proxy use. OBJECTIVE: To evaluate the psychometric properties of the 29 item Multiple Sclerosis Impact Scale (MSIS-29) when used by proxies of MS patients. METHODS: A sample of 62 partners of MS patients completed the MSIS-29. The data were evaluated for the psychometric criteria of the MSIS-29, including data quality, scaling assumptions, acceptability, reliability, validity, and responsiveness. RESULTS: Psychometric evaluation was satisfactory; data quality was high, and scaling assumptions and acceptability were good. Reliability was high (alpha>0.80). Findings were consistent with results of a psychometric evaluation in a patient sample. CONCLUSIONS: The MSIS-29 can be used reliably in proxies of patients with MS. As a next step the relation between data obtained from patients and proxies needs to be studied, focusing on factors that may affect agreement and discrepancies.  相似文献   
75.
甲硝唑葡萄糖注射液细菌内毒素检查法的研究   总被引:1,自引:0,他引:1  
目的;以细菌内毒素检查法对甲硝唑葡萄糖注射液进行试验研究。方法;采用抑制或增强试验,并将细菌内毒素检查法与家兔法检测结果作对比。结果:该注射液经一定稀释后对测定无干扰。结论:细菌内毒素检查法适用于检测该注射液。  相似文献   
76.
77.
Ocular MR imaging and spectroscopy: an ex vivo study   总被引:2,自引:0,他引:2  
Six eyes, freshly enucleated because of choroidal melanoma, were imaged on a 1.4-T superconducting magnetic resonance (MR) imaging system, and relaxation times were calculated for various parts of the eye. Unfixed fresh tissue samples were obtained for nuclear magnetic resonance spectroscopy (NMRS) on a variable-field (0.19-1.4 T) resistive unit. Detailed ocular anatomy was demonstrated. The NMRS relaxation times correlated with the MR imaging intensity patterns. The sensitivity of MR imaging to states of hydration provides an excellent window for appreciation of ocular anatomy.  相似文献   
78.
Rafii  M; Firooznia  H; Bonamo  JJ; Minkoff  J; Golimbu  C 《Radiology》1987,162(2):559-564
Forty-three professional and amateur athletes with persistent shoulder pain that interfered with their sports activities were evaluated by computed tomographic (CT) arthrography. In 19 patients, glenohumeral instability (14 anterior, two posterior, three multidirectional) was diagnosed with CT arthrography based on the simultaneous presence of labral and capsular lesions. The findings were crucial in establishing the diagnosis of instability in six patients in whom the condition was not suggested or could not be confirmed clinically. Another significant injury consisted of labral lesions not associated with glenohumeral instability. These tears often involved the anterior and parasuperior segments of this structure. Other, less frequently detected lesions included segmental labral enlargement and several labra with abnormal orientation (everted labrum). Early onset of degenerative disease was present in many athletes, especially those with a long history of sports activity. CT arthrographic findings were correlated with arthroscopic or surgical results in 19 patients.  相似文献   
79.
The possible existence of human immunodeficiency virus type 1 (HIV-1) infection in asymptomatic seronegative at-risk individuals was investigated in a prospective study of 55 seronegative high-risk individuals (42 homosexual men and 13 heterosexual individuals) and 32 seronegative hemophiliacs treated with factor VIII or IX concentrates before viral inactivation by heat treatment and systematic screening of blood donations. Tests used include the polymerase chain reaction assay with three primer pairs (one in the gag region and two in the pol region) and tests for serum p24 antigen, anti-nef serology (Western blot), and five biologic markers frequently altered by HIV infection (CD4 lymphocyte count, serum beta 2-microglobulin and neopterin concentration, and serum IgG and IgA concentration). Although 91 of 92 HIV-1-seropositive persons were positive in testing with at least one primer pair, no positive result was observed in seronegative at-risk individuals or in 117 seronegative low-risk controls. No nef antibody was found in seronegative at-risk individuals or seronegative controls, but 44 (47%) of 92 HIV-1-seropositive persons had nef antibodies. These findings do not support the existence of frequent HIV-1 infection in seronegative at-risk individuals.  相似文献   
80.
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