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   1897篇
  免费   148篇
  国内免费   11篇
耳鼻咽喉   3篇
儿科学   134篇
妇产科学   26篇
基础医学   201篇
口腔科学   54篇
临床医学   250篇
内科学   339篇
皮肤病学   35篇
神经病学   100篇
特种医学   261篇
外科学   189篇
综合类   57篇
一般理论   1篇
预防医学   179篇
眼科学   32篇
药学   132篇
  1篇
肿瘤学   62篇
  2021年   16篇
  2020年   20篇
  2019年   21篇
  2018年   23篇
  2017年   22篇
  2016年   29篇
  2015年   34篇
  2014年   42篇
  2013年   56篇
  2012年   71篇
  2011年   57篇
  2010年   67篇
  2009年   65篇
  2008年   67篇
  2007年   38篇
  2006年   34篇
  2005年   51篇
  2004年   42篇
  2003年   50篇
  2002年   50篇
  2001年   48篇
  2000年   46篇
  1999年   35篇
  1998年   91篇
  1997年   98篇
  1996年   99篇
  1995年   64篇
  1994年   55篇
  1993年   54篇
  1992年   36篇
  1991年   37篇
  1990年   27篇
  1989年   54篇
  1988年   56篇
  1987年   48篇
  1986年   27篇
  1985年   46篇
  1984年   25篇
  1983年   23篇
  1982年   20篇
  1981年   26篇
  1980年   13篇
  1979年   25篇
  1978年   16篇
  1977年   11篇
  1976年   15篇
  1975年   11篇
  1971年   9篇
  1969年   15篇
  1968年   12篇
排序方式: 共有2056条查询结果,搜索用时 15 毫秒
1.
2.
3.
Patients with cerebellar deficits made elbow flexion movements as rapidly as possible for three different angular distances. Electromyographic activity of biceps and triceps and the kinematics of the movements were analysed. Results were compared with those of normal subjects making both rapid and slow movements. In the patients, the first agonist burst of the biceps was frequently prolonged regardless of the distance or speed of the movement. The most striking kinematic abnormality was prolonged acceleration time. The pattern of acceleration time exceeding deceleration time was common in patients but uncommon in normal subjects. The best kinematic correlate of the duration of the first agonist burst was acceleration time. Altered production of appropriate acceleration may therefore be an important abnormality in cerebellar dysfunction for attempted rapid voluntary movements.  相似文献   
4.
Community pharmacists contribution to the management of drug problems is considerable. As the use of illicit drugs has increased, pharmacists have come under increasing pressure to offer services to problem drug users. However, there is concern among some pharmacists that offering such services may deter other customers. There is particular concern among some pharmacists about needle exchange services. Only 9.5% of Scottish pharmacies offer needle exchange services compared to 69% which are dispensing methadone (57% of which supervise methadone consumption). Qualitative interviews were used in a purposive sample of 10 pharmacies in Scotland. Eight customers were interviewed in each pharmacy to ascertain pharmacy customers’ views on these services. The majority of customers were supportive of these services. Customers were often unaware that the pharmacy they were interviewed in was offering services for people with drug problems. Pharmacy customers were more knowledgeable about, and more supportive, of needle exchange services than they were of methadone. This was because they believed needle exchange services helped to reduce the amount of discarded needles in public places. Pharmacy customers also recognised that needle exchange helped reduce the spread of disease. These findings should be used to encourage more pharmacists to offer needle exchange services.  相似文献   
5.

Background  

The aims of this study were to examine the extent to which higher intellectual abilities protect higher socio-economic groups from functional decline and to examine whether the contribution of intellectual abilities is independent of childhood deprivation and low birth weight and other socio-economic and developmental factors in early life.  相似文献   
6.
This study reports on the development of a model for studying skeletal muscle metabolism in humans using NMR spectroscopy. Graded exercise was simulated using electrical stimulation in 10 healthy, fit subjects (mean VO2max = 53 +/- 4 ml.kg-1.min-1). The effects of varying the stimulation parameters, namely, the stimulation frequency, the stimulation intensity, and the duty cycle, as well as the spectral interrogation volume, were compared using data acquired from the rectus femoris muscle. With stimulation, the inorganic phosphate to phosphocreatine concentration ratio ([P(i)]/[PCr]) and the intracellular pH both follow curvilinear relationships over the stimulation frequencies from 3 to 30 Hz, with the magnitude of the observed change related closely to stimulation intensity and duty cycle. Oxidative phosphorylation predominates at stimulation frequencies below 12 Hz, while anaerobic metabolism increases sharply above 12 Hz. Our findings show clearly the interdependence of the effects of the various stimulation parameters and emphasize the care that must be exercised in interpreting the physiological significance of the biochemical data obtained from electrical stimulation models used to study skeletal muscle metabolism.  相似文献   
7.
8.
Defecography in multiple sclerosis patients with severe constipation   总被引:3,自引:0,他引:3  
Gill  KP; Chia  YW; Henry  MM; Shorvon  PJ 《Radiology》1994,191(2):553
  相似文献   
9.
Previous reports in the literature have described correlation of increasing repeat length with severity of the phenotype, in Kennedy syndrome. We describe male siblings with different repeat lengths, with lack of expression of the phenotype in the sibling with the longer repeat length. The phenotype was identical to motor neurone disease. There is variability of expression in Kennedy syndrome and repeat length even in siblings cannot be taken as a conclusive indicator of severity. CAG repeat length cannot be used to predict the natural history of Kennedy disease. The diagnosis of Kennedy syndrome should be considered in male patients presenting with atypical motor neurone disease.  相似文献   
10.
SUMMARY The interferons are natural glycoproteins secreted in response to various stimuli, including viral infection. They have antiviral, antiproliferative and immunomodulatory effects on different target cell populations. Since recombinant human interferons have become available, they have been tested in a wide range of malignancies. They are well established in the treatment of hairy cell leukaemia, chronic myelogenous leukaemia and multiple myeloma. Although they have documented activity against lymphoma, melanoma, renal cell cancer and carcinoid tumours, their role in the treatment of these tumours is less clear. In the common solid tumours, such as lung cancer and colorectal cancer, the use of interferons remains experimental. Here we will summarise their practice applications in oncology, using randomised studies where available to establish their place in multi-modality treatment. We will not discuss their use as antiviral or immunomodulating agents in viral and autoimmune diseases, multiple sclerosis or after organ transplantation.  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