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   31790篇
  免费   1644篇
  国内免费   139篇
耳鼻咽喉   454篇
儿科学   653篇
妇产科学   392篇
基础医学   4513篇
口腔科学   796篇
临床医学   2173篇
内科学   7836篇
皮肤病学   824篇
神经病学   2248篇
特种医学   1243篇
外国民族医学   1篇
外科学   4937篇
综合类   155篇
一般理论   2篇
预防医学   939篇
眼科学   531篇
药学   2388篇
中国医学   97篇
肿瘤学   3391篇
  2023年   181篇
  2022年   387篇
  2021年   609篇
  2020年   343篇
  2019年   425篇
  2018年   576篇
  2017年   467篇
  2016年   559篇
  2015年   554篇
  2014年   823篇
  2013年   913篇
  2012年   1463篇
  2011年   1655篇
  2010年   936篇
  2009年   875篇
  2008年   1475篇
  2007年   1666篇
  2006年   1548篇
  2005年   1662篇
  2004年   1521篇
  2003年   1370篇
  2002年   1347篇
  2001年   1062篇
  2000年   985篇
  1999年   951篇
  1998年   363篇
  1997年   252篇
  1996年   274篇
  1995年   223篇
  1994年   205篇
  1993年   212篇
  1992年   645篇
  1991年   563篇
  1990年   546篇
  1989年   544篇
  1988年   528篇
  1987年   494篇
  1986年   473篇
  1985年   434篇
  1984年   321篇
  1983年   263篇
  1982年   164篇
  1979年   252篇
  1977年   189篇
  1973年   177篇
  1972年   187篇
  1971年   193篇
  1970年   172篇
  1969年   186篇
  1968年   170篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
A 52-year-old woman who developed acute transverse myelopathy following systemic lupus erythematosus (SLE) was reported. At the age of 46, she was diagnosed as having atypical psychosis. Neurological examination revealed mild depressive state, paraparesis, diffuse hyperreflexia, hypesthesia below the breasts, and urinary disturbance. Gait was slightly ataxic and Romberg sign was positive. Laboratory study disclosed lymphocytopenia, positive antinuclear antigen, false positive Venereal Disease Research Laboratories flocculation test and prolonged activated partial thromboplastin time. IgG anticardiolipin antibody (aCLA) was positive, whereas IgM aCLA was negative. Cerebrospinal fluid was normal except the elevation of %IgG. Nerve conduction studies were normal and no abnormality was detected in the brain and spinal cord by MRI and CT. We treated her by two series of steroid pulse therapy, which resulted in marked improvement of symptoms and disappearance of aCLA. Before and after the pulse therapy, symptoms were fluctuated in parallel with the levels of aCLA. These findings suggest the relation of aCLA to the transverse myelopathy in SLE. This is the first case report of a good prognosis of myelopathy in a SLE patient who was treated by steroid pulse therapy with the aim of disappearance of aCLA.  相似文献   
42.
43.
44.
45.
Repeated injections of 45 ng/kg of maitotoxin into the peritoneal cavities of male ICR mice resulted in marked atrophy of lymphoid tissues, a reduction of lymphocytes in the circulating blood, reduced immunoglobulin M in serum, and an increase of calcium content in the adrenal glands. A single injection of 200 ng/kg of maitotoxin induced a marked increase in total calcium content of the adrenal glands as well as in plasma cortisol concentration (about seven times control) within 1 hr. In contrast, mice pretreated with CoCl2, a calcium channel inhibitor, and/or adrenalectomized mice, showed no discernible changes in the lymphoid tissues after repeated injections of maitotoxin. It is thus suggested that maitotoxin first stimulates calcium influx in the adrenal glands, which then causes the release of cortisol into the blood. The excess amount of cortisol in serum produces acute involution of the thymus and other lymphoid tissues.  相似文献   
46.
Anatomical reconstruction of the thyroglossal duct   总被引:9,自引:0,他引:9  
  相似文献   
47.
48.
49.
Spinal Trabecular Bone Loss and Fracture in American and Japanese Women   总被引:7,自引:0,他引:7  
This study examined trabecular bone mineral density (BMD) in Japanese women with and without spinal fracture, and compared the results to American women with and without fracture. The quantitative computed tomography (QCT) systems used at the University of California, San Francisco (UCSF) and at Nagasaki University were cross-calibrated. Normative BMD was assessed with the K2HPO4 liquid phantom in 538 Americans aged 20–85 years, and with the B-MAS200 phantom in 577 Japanese aged 20–83 years. These BMD were adjusted for use with the Image Analysis solid phantom using the result of cross-calibration. The trabecular BMD in 111 postmenopausal American women (55 with fracture), and in 185 postmenopausal Japanese women (67 with fracture) were compared for investigation of the difference in BMD values relative to fracture status. The absolute BMD values in Japanese were lower than those in Americans, and the differences were greater with advancing age. The magnitude of the BMD difference was 8.6, 20.5, 38.1 mg/cm3 in women aged 20–24 years, 40–44 years, 60–64 years, respectively. In premenopausal women, BMD began to decrease at the age of 20 in Japanese, whereas the peak bone mass was maintained until the age of 35 in the American women. In immediate postmenopausal women, BMD significantly decreased in both populations. In later postmenopausal women, BMD significantly decreased with age in the Japanese women but decreased less rapidly in the American women. The aging decrease of BMD was 1.4% and 2.2% per year in the later postmenopausal American and Japanese women, respectively. The fracture threshold is considered to be lower in Japanese women. However, the BMD difference between American and Japanese women with fracture was similar to that without fracture. The Z-scores of fracture subjects versus controls were 2.9 in American and 1.8 in Japanese women. In conclusion, Japanese women were found to have a lower BMD and lower fracture threshold than American women. The significant decrease of spinal trabecular BMD in late postmenopause is potentially responsible for the higher prevalence of spinal fracture in Japanese women. Received: 18 December 1995 / Accepted: 23 September 1996  相似文献   
50.
A case of a bilateral pulmonary hernia of the lungs into the supraclavicular fossae is described. A man, aged 79, with severe chronic asthma and chronic bronchitis due to air pollution, complained of a cervical mass off and on for several years. The herniation was greater on the right side. It could be identified on physical examination by the presence of a soft painless supraclavicular bulge which was exaggerated by strain or cough. Radiologically this herniation could best be identified on lateral cervical roentgenogram. It is said that cervical lung hernia is a rare condition, but in our experience supraclavicular herniation of the lung is not unusual in cases of severe chronic obstructive lung disease.  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