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   2460500篇
  免费   198898篇
  国内免费   4352篇
耳鼻咽喉   35694篇
儿科学   76700篇
妇产科学   65999篇
基础医学   346657篇
口腔科学   69703篇
临床医学   221675篇
内科学   484274篇
皮肤病学   50450篇
神经病学   207116篇
特种医学   99600篇
外国民族医学   918篇
外科学   374205篇
综合类   57475篇
现状与发展   1篇
一般理论   1002篇
预防医学   195037篇
眼科学   58113篇
药学   183767篇
  4篇
中国医学   4690篇
肿瘤学   130670篇
  2018年   24890篇
  2016年   21411篇
  2015年   24292篇
  2014年   34811篇
  2013年   52681篇
  2012年   71250篇
  2011年   74773篇
  2010年   44088篇
  2009年   42350篇
  2008年   71290篇
  2007年   75735篇
  2006年   76705篇
  2005年   74849篇
  2004年   72069篇
  2003年   69653篇
  2002年   68762篇
  2001年   117012篇
  2000年   120999篇
  1999年   102199篇
  1998年   28999篇
  1997年   26602篇
  1996年   26364篇
  1995年   25453篇
  1994年   23895篇
  1993年   22283篇
  1992年   81926篇
  1991年   78815篇
  1990年   76092篇
  1989年   73227篇
  1988年   67984篇
  1987年   66828篇
  1986年   63377篇
  1985年   60279篇
  1984年   45664篇
  1983年   38837篇
  1982年   23551篇
  1981年   21014篇
  1980年   19584篇
  1979年   42666篇
  1978年   30020篇
  1977年   25197篇
  1976年   23548篇
  1975年   24893篇
  1974年   30571篇
  1973年   28958篇
  1972年   27042篇
  1971年   24919篇
  1970年   23462篇
  1969年   21729篇
  1968年   19784篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Mycobacterium ulcerans infection in Ashanti region, Ghana   总被引:1,自引:0,他引:1  
We describe a series of 96 cases of Mycobacterium ulcerans infection (Buruli ulcer) from a new endemic focus in the Afram valley, north of Agogo, in Ghana. 63 cases were children under 13 years old. Active treatment by excision and skin grafting necessitates long stays in hospital and repeated procedures. Scarring and contracture are frequent. Eyes and other vital organs may be destroyed. In its endemic foci Buruli ulcer is a serious health burden on rural populations. Research is urgently needed, especially in prevention and non-surgical management.  相似文献   
992.
993.
Diabetic polyneuropathy   总被引:1,自引:0,他引:1  
  相似文献   
994.
Single parent women   总被引:1,自引:1,他引:0  
Summary While there has been considerable interest in the problems of single parent families, no study has yet determined if the problems are due to increased risk of specific psychiatric disorders in single parents as compared to their married counterparts. Data collected as part of the National Institute of Mental Health Epidemiologic Catchment Area (ECA) Project are presented to compare the psychiatric as well as economic and social functioning of single vs. married parent women ages 18–44, based on a probability sample of members of the greater New Haven community. The major finding between groups is their relative similarity in psychiatric as well as social functioning. The major difference is economic. Single parents, both Black and White, more frequently are less educated and poorer. While many are on welfare, single compared to married female parents are more likely to be working and to report insufficient income to meet their needs. There are no appreciable differences in social contacts, use of health services or six-month prevalence rates of psychiatric disorders including major depression, alcohol or drug abuse. The data suggest that the problems faced by single parent women and their children may be a reflection of poverty and stress in families and not of psychiatric disorders or poor social relations in mothers.  相似文献   
995.
The distribution of tyrosine-hydroxylase (TH)-immunoreactive cell bodies and fibers in the diencephalon has been investigated with immunohistological techniques in the pigeon. The results suggest that TH is present in a number of morphologically distinct neuronal systems. Preoptic and hypothalamic TH neurons were subdivided into a medial periventricular and a lateral group. The medial group starts with a rostral collection of small cells in the preoptic region. A significantly larger collection of TH neurons occupies the paraventricular nucleus (PVN) (stratum cellulare internum) and mainly consists of large multipolar cells. Further caudally, the main concentration of cells is in the hypothalamic posteromedial and the periventricular regions of the tuberoinfundibular (arcuate) nucleus. No TH neuron was found in the ventral and lateral parts of the tuberoinfundibular region, suggesting that the prominent tuberoinfundibular dopaminergic system described in mammals is absent in the pigeon. This further substantiated by the relative scarcity of TH immunoreactive fibers and varicosities in the neurohemal zone of the median eminence (ME). The caudalmost components of the medial group appear to be continuous with the large population of TH neurons distributed in the midline of the mesencephalon. Tyrosine-hydroxylase-immunopositive cells have not been found in the paraventricular organ. The lateral group consists of TH neurons loosely arranged in the lateral hypothalamus, including regions of the supraoptic nucleus and hypothalamic posterolateral nucleus. Tyrosine-hydroxylase containing neurons vary widely in size, shape, and dendritic arborization in each diencephalic region. However, it is possible to distinguish two main cell types. Small bipolar neurons with two simple arborizing dendrites were concentrated in the medial periventricular system. The second type of cell is large, multipolar with four to five branching dendrites. This latter cell type occurs mainly in the lateral system and in the PVN. Major fiber bundles containing TH immunoreactivity were identified in the lateral and periventricular hypothalamus. The paraventricular organ and the organum vasculosum laminae terminalis contained the densest arborization of fibers and varicosities. In the ME, dense innervation was found in the subependymal layer. Dense arborizations of TH positive fibers and varicosities were located in the septal nuclei and the paleostriatum augmentatum.  相似文献   
996.
Topographic electroencephalography was carried out to study reaction to photic stimulation in 29 normal volunteers, and 12 patients who had presented frequent clinically confirmed migraines for at least 3 years. In the group of migraineurs photic stimulation resulted in an increase in the alpha band power. The difference between the two groups was statistically significant. This reaction to photic stimulation is of help in diagnosis and suggests that a diagnosis and therapeutic orientation might be possible in patients for whom clinical diagnosis is not clear. The specificity of the migraineur's reaction to photic stimulation and its possible origin are discussed.  相似文献   
997.
998.
The role of timing of transplant nephrectomy after renal transplantation has not been well defined. This report compares the morbidity, mortality, and hospitalization costs of 37 patients undergoing transplant nephrectomy within 14 days after graft failure and return to dialysis, with 31 patients undergoing delayed transplant nephrectomy (less than 14 days after graft failure and return to dialysis). This analysis revealed that there were no significant (P greater than .05) differences in patient morbidity and mortality between these groups. There was, however, a substantial increase (P less than .05) in the cost of hospitalization in the delayed nephrectomy group. For this reason, we recommend early nephrectomy after renal transplant failure in order to minimize the cost of health care for these patients undergoing failed cadaver donor transplant nephrectomy.  相似文献   
999.
A sample consisting of 1135 edentulous patients with clinically healthy denture bearing areas, was examined radiologically. It appears that the diagnostic yield is high whereas the expected radiation induced risk is low. Patients should therefore be examined radiologically prior to full denture construction.  相似文献   
1000.
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