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   45777篇
  免费   5089篇
  国内免费   80篇
耳鼻咽喉   326篇
儿科学   1378篇
妇产科学   904篇
基础医学   6273篇
口腔科学   1242篇
临床医学   5693篇
内科学   9007篇
皮肤病学   719篇
神经病学   3632篇
特种医学   1942篇
外国民族医学   1篇
外科学   6050篇
综合类   1287篇
一般理论   26篇
预防医学   5316篇
眼科学   848篇
药学   3796篇
中国医学   116篇
肿瘤学   2390篇
  2021年   605篇
  2020年   375篇
  2019年   656篇
  2018年   749篇
  2017年   534篇
  2016年   613篇
  2015年   729篇
  2014年   976篇
  2013年   1396篇
  2012年   2028篇
  2011年   2034篇
  2010年   1185篇
  2009年   1145篇
  2008年   1921篇
  2007年   2020篇
  2006年   1999篇
  2005年   1903篇
  2004年   1747篇
  2003年   1674篇
  2002年   1625篇
  2001年   1549篇
  2000年   1476篇
  1999年   1477篇
  1998年   624篇
  1997年   515篇
  1996年   515篇
  1995年   514篇
  1994年   452篇
  1993年   496篇
  1992年   1215篇
  1991年   1130篇
  1990年   1081篇
  1989年   1061篇
  1988年   986篇
  1987年   981篇
  1986年   992篇
  1985年   905篇
  1984年   780篇
  1983年   635篇
  1982年   433篇
  1981年   356篇
  1980年   350篇
  1979年   589篇
  1978年   485篇
  1977年   375篇
  1976年   385篇
  1974年   432篇
  1973年   400篇
  1972年   386篇
  1969年   359篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
The talar beak is a well-described secondary sign of talocalcaneal coalition but is not pathognomonic of the condition and may be seen in other causes of restricted or abnormal subtalar motion. We present an unusual complication of talar beaks in two patients who sustained fractures through their beaks. One of the patients described did not have a talocalcaneal coalition but had developed a beak following a compound fracture dislocation of the ankle joint complicated by infection, a previously undescribed predisposing cause.  相似文献   
23.
A case study of multicentric reticulohistiocytosis is presented with extensive immunohistochemical studies of the infiltrate in both paraffin and cryostat sections. These studies showed that the cells are of monocyte/macrophage origin. B- and T-cell gene rearrangement analysis of multicentric reticulohistiocytosis was also performed and showed a germline configuration.  相似文献   
24.
25.
In order to ascertain the tamponade effect of air and silicone oil we examined the contact angles subtended by ex vivo human retina, Teflon and Perspex to find a suitable experimental material which would mimic the surface properties of the retina at a three-phase interface. Using the captive bubble technique to measure the contact angle, it was found that air subtended a larger contact angle (38.8°) with the retina than did silicone oil (18.2°). On coating the Perspex surface with protein (PCP), it was observed that the surface properties were modified such that PCP subtended contact angles with air (43.0°) and silicone oil (16.4°) similar to those subtended by ex vivo human retina. Using PCP as an experimental material that mimics ex vivo human retina, spherical chambers were employed in order to examine qualitatively and to quantify the arc of contact obtained with air and silicone oil. It was found that air gave a greater arc of contact for the same percentage fill than silicone oil.  相似文献   
26.
Calcium, cell signalling and cataract   总被引:5,自引:0,他引:5  
  相似文献   
27.
S D Sharp  R R Williams 《Cardiology》1992,81(4-5):207-212
The mechanism by which increased left ventricular (LV) mass leads to increased coronary heart disease morbidity and mortality is unknown. We evaluated the relation between fasting insulin and echocardiographic LV mass in hypertensives off medication and normotensive controls, controlling the analyses for blood pressure (BP) and body mass index (BMI). Fasting insulin (p = 0.0217) was the most significant predictor of LV mass in hypertensives, while BMI (p = 0.0265) and diastolic BP (p = 0.0159) were the only significant predictors of LV mass in controls. The relation between fasting insulin and LV mass was not confounded by obesity in hypertensives, but obesity and fasting insulin may interact to predict LV mass.  相似文献   
28.
A study of the angiographic findings in consecutive civilian patients with cranial gunshot wounds examined in the acute stage has not been done. Most prior clinical studies have evaluated the findings in survivors in the subacute or chronic stages and have often been of war-time casualties. We determined the clinicoradiologic features of six cases of posttraumatic intracranial aneurysm, vascular occlusion, or arteriovenous fistula caused by penetrating missiles among 12 civilian patients who were examined in the acute posttraumatic stage (within 48 hr of injury) during a 1-year period. Three internal carotid/vertebral artery aneurysms, one external carotid artery aneurysm, one combined aneurysm/arteriovenous fistula of the vertebrobasilar circulation, and one cerebral venous occlusion were identified. The 50% overall prevalence of major vascular lesions in this series of civilian patients with penetrating missile injuries examined in the acute stage suggests these injuries are more common than previously suspected. It may indicate that selective cerebral angiography should be considered in the evaluation of the cranial vascular system of such persons.  相似文献   
29.
We have produced a range of monoclonal antibodies which stain human intrahepatic bile ducts of different sizes. Amongst 26 monoclonal antibodies produced, five clones reacted specifically with bile ducts of different sizes, of which three have been maintained in culture and their viability following freezing and thawing confirmed. Staining patterns varied between normal adult liver tissue, normal fetal liver tissue and a variety of hepatobiliary diseases. The antibodies provide further evidence of the immunological heterogeneity of the human intrahepatic biliary tree and support the hypothesis that proliferating bile ductules are derived from periseptal hepatocytes. The preparation of the antibodies, their staining reactions in normal adult, normal fetal and a variety of liver diseases are described.  相似文献   
30.
The management of patients presenting with supratentorial glioma between 1978 and 1986 is reviewed. Complete follow-up in 517 cases was obtained. One hundred and fifty eight patients were not submitted to any form of surgery, 299 patients were biopsied and 60 patients underwent craniotomy and internal decompression. The no surgery group contained a higher proportion of patients with poor prognostic indicators than either the biopsy or craniotomy groups. The craniotomy group consisted of patients with better prognostic indicators than the biopsy group, in particular, younger age and more favourable site, type and grade of tumour. This was reflected in the difference in outcome between the groups. Median survival was 14 months in the craniotomy group, four months in the biopsy group and 2.2 months in the no surgery group. The outcome in patients with histologically proven malignant gliomas was best in those patients who received radiotherapy. The craniotomy group had a median survival of 18.5 months, a two year survival of 48% and a five year survival of 9%. The median survival following radiotherapy of those patients with proven malignant gliomas who had a biopsy was 9.5 months with a two year survival of 16% and a five year survival of 2%. These results compare favourably with studies which have adopted a more aggressive approach, suggesting that outcome is determined as much by patient selection using favourable prognostic indicators as by the treatment itself. The need for prospective trials of the management of unselected consecutive glioma patients randomizing them to conservative and radical treatment groups in order to define the role of both conventional therapy and radical therapy is discussed.  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