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   206135篇
  免费   5309篇
  国内免费   1508篇
耳鼻咽喉   2810篇
儿科学   7551篇
妇产科学   5953篇
基础医学   26386篇
口腔科学   6042篇
临床医学   16815篇
内科学   36619篇
皮肤病学   4624篇
神经病学   12189篇
特种医学   11047篇
外国民族医学   102篇
外科学   30425篇
综合类   3471篇
现状与发展   4篇
一般理论   2篇
预防医学   17087篇
眼科学   4675篇
药学   14727篇
  3篇
中国医学   810篇
肿瘤学   11610篇
  2021年   788篇
  2018年   3975篇
  2017年   4243篇
  2016年   3548篇
  2015年   5434篇
  2014年   4961篇
  2013年   3920篇
  2012年   10593篇
  2011年   5614篇
  2010年   2794篇
  2009年   4292篇
  2008年   2616篇
  2007年   3306篇
  2006年   3504篇
  2005年   11656篇
  2004年   13019篇
  2003年   8589篇
  2002年   3772篇
  2001年   4688篇
  2000年   2034篇
  1999年   6181篇
  1998年   773篇
  1992年   6978篇
  1991年   7184篇
  1990年   7443篇
  1989年   7009篇
  1988年   6537篇
  1987年   6294篇
  1986年   6009篇
  1985年   5281篇
  1984年   3625篇
  1983年   2916篇
  1982年   1012篇
  1981年   778篇
  1980年   844篇
  1979年   3836篇
  1978年   2366篇
  1977年   1783篇
  1976年   1561篇
  1975年   2479篇
  1974年   3111篇
  1973年   2743篇
  1972年   2760篇
  1971年   2742篇
  1970年   2559篇
  1969年   2466篇
  1968年   2237篇
  1967年   2167篇
  1966年   1903篇
  1965年   1133篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
131.
We found that thirteen per cent of all head and neck malignomas are malignant lymphomas. In 75% of these cases the Non-Hodgkin type could be found. The major salivary glands were involved by the lymphoma in 55% out of 104 patients. Paraglandular lymph nodes of the parotid gland were affected as well as intraglandular lymph nodes and the lymphoid tissue within the gland proper. The submandibular gland normally shows an involvement only with its paraglandular lymph nodes. Two thirds of the Non-Hodgkin lymphomas located in the salivary glands were low-grade. In case of clinical suspicion of a malignant lymphoma, fine needle biopsy is required for cytological diagnosis. However, surgery is mandatory for histological diagnosis, not as a therapeutic measure.  相似文献   
132.
133.
134.
135.
Irradiation of a cytosolic fraction from vascular smooth muscle in the presence of [3H]felodipine resulted in the labelling of a protein with an apparent molecular weight of 62 kDa. The labelling was seen on UV-irradiation at 360 nm, but not at 254, 278 or at wavelengths above 410 nm. The photolabelling was enhanced in the absence of oxygen. In cytosolic fractions prepared from porcine liver, cardiac and skeletal muscle no photoaffinity labelling of proteins between 90 and 45 kDa could be demonstrated. The results suggest that felodipine is a photoaffinity ligand and that felodipine binds to a soluble protein present in vascular smooth muscle but not in the other tissues tested.  相似文献   
136.
A new technique for ultrasonic examination of the hip joint was evaluated in neonatals and infants. An anterior approach was used with the sound sector centered over the femoral head and parallel to the femoral neck. The ultrasonograms corresponded to lateral radiographs of the joint with the leg in Lorenz' first position. It was possible to evaluate the size and depth of the acetabulum and the size and position of the femoral head. The projection also permitted a dynamic examination for determination of hip instability. Thus, the technique provided a method for an objective diagnosis in congenital dislocation of the hip (CDH). In 216 hips, the results of clinical evaluation for CDH were correlated with the degree of instability demonstrated by ultrasound. The comparison showed the clinical diagnosis to be highly inaccurate.  相似文献   
137.
138.
PURPOSE: The purpose to clarify what kind of managerial challenges employees experience regarding organisational justice in hospitals. DESIGN/METHODOLOGY/APPROACH: This exploratory study of 8,971 employees working in 14 hospitals and examines the concept of organisational justice in management with qualitative and quantitative methods. FINDINGS: An inductive content analysis of the comments revealed five integrative frames describing challenges in hospital management at respondents' workplaces. These frames should be regarded as major managerial challenges in hospitals. These findings illustrate important antecedents of organisational justice and suggest that work units tend to share the same perceptions of justice. They also reveal that individually produced comments reflect collective experiences in organisational justice. Further, the results indicate that problems in management and policies are often experienced in a complex way, and people making justice judgements do not separate procedural and interactional factors. RESEARCH LIMITATIONS/IMPLICATIONS: Although the commentators producing qualitative data represented many organisational hierarchy levels, the results should not be generalised to apply to horizontal, informal social relationships. PRACTICAL IMPLICATIONS: This paper gives useful information regarding challenges in human resources management in hospitals. ORIGINALITY/VALUE: The paper suggests that people making fairness judgements do not make a distinction between procedural and interpersonal factors. Instead, they use any information available to judge the righteousness of the management events. This paper serves to guide hospital managers towards a better understanding of the importance of organisational justice and its collective nature.  相似文献   
139.
Low-trauma fractures of elderly people are a major public health burden worldwide, and as the number and mean age of older adults in the population continue to increase, the number of fractures is also likely to increase. Epidemiologically, however, an additional concern is that, for unknown reasons, the age-standardized incidence (average individual risk) of fracture has also risen in many populations during the recent decades. Possible reasons for this rise include a birth cohort effect, deterioration in the average bone strength by time, and increased average risk of (serious) falls. Literature provides evidence that the rise is not due to a birth cohort effect, whereas no study shows whether bone fragility has increased during this relatively short period of time. This osteoporosis hypothesis could, however, be tested if researchers would now repeat the population measurements of bone mass and density that were made in the late 1980s and the 1990s. If such studies proved that women's and men's age-standardized mean values of bone mass and density have declined over time, the osteoporosis hypothesis would receive scientific support. The third explanation is based on the hypothesis that the number and/or severity of falls has risen in elderly populations during the recent decades. Although no study has directly tested this hypothesis, a great deal of indirect epidemiologic evidence supports this contention. For example, the age-standardized incidence of fall-induced severe head injuries, bruises and contusions, and joint distortions and dislocations has increased among elderly people similarly to the low-trauma fractures. The fall hypothesis could also be tested in the coming years because the 1990s saw many research teams reporting age- and sex-specific incidences of falling for elderly populations, and the same could be done now to provide data comparing the current incidence rates of falls with the earlier ones.  相似文献   
140.
In 50 children, 4 months to 12 years of age, with minor head trauma non-target visual event-related potentials were performed and compared to a second registration of the potentials some months later. On following-up there was a clear tendency for a relative improvement of the latencies of the endogenous potentials. In this way non-target visual event-related potentials proved to be of value in the investigation of mental impairment in early childhood.  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