全文获取类型
收费全文 | 93589篇 |
免费 | 8526篇 |
国内免费 | 212篇 |
专业分类
耳鼻咽喉 | 1030篇 |
儿科学 | 2823篇 |
妇产科学 | 2334篇 |
基础医学 | 12757篇 |
口腔科学 | 1989篇 |
临床医学 | 10957篇 |
内科学 | 18533篇 |
皮肤病学 | 1383篇 |
神经病学 | 8465篇 |
特种医学 | 2997篇 |
外国民族医学 | 1篇 |
外科学 | 13569篇 |
综合类 | 1862篇 |
一般理论 | 97篇 |
预防医学 | 8823篇 |
眼科学 | 1869篇 |
药学 | 7181篇 |
1篇 | |
中国医学 | 111篇 |
肿瘤学 | 5545篇 |
出版年
2022年 | 495篇 |
2021年 | 1342篇 |
2020年 | 867篇 |
2019年 | 1456篇 |
2018年 | 1729篇 |
2017年 | 1304篇 |
2016年 | 1440篇 |
2015年 | 1691篇 |
2014年 | 2393篇 |
2013年 | 3680篇 |
2012年 | 5259篇 |
2011年 | 5550篇 |
2010年 | 3169篇 |
2009年 | 2900篇 |
2008年 | 5155篇 |
2007年 | 5482篇 |
2006年 | 5354篇 |
2005年 | 5376篇 |
2004年 | 5186篇 |
2003年 | 4790篇 |
2002年 | 4857篇 |
2001年 | 2013篇 |
2000年 | 1855篇 |
1999年 | 1850篇 |
1998年 | 1324篇 |
1997年 | 1079篇 |
1996年 | 933篇 |
1995年 | 902篇 |
1994年 | 818篇 |
1993年 | 772篇 |
1992年 | 1407篇 |
1991年 | 1305篇 |
1990年 | 1261篇 |
1989年 | 1185篇 |
1988年 | 1093篇 |
1987年 | 1074篇 |
1986年 | 1091篇 |
1985年 | 1115篇 |
1984年 | 1035篇 |
1983年 | 900篇 |
1982年 | 812篇 |
1981年 | 694篇 |
1980年 | 694篇 |
1979年 | 756篇 |
1978年 | 627篇 |
1977年 | 538篇 |
1976年 | 537篇 |
1974年 | 522篇 |
1973年 | 466篇 |
1972年 | 423篇 |
排序方式: 共有10000条查询结果,搜索用时 937 毫秒
61.
62.
Computed tomography findings in gastrointestinal involvement by opportunistic organisms in acquired immune deficiency syndrome 总被引:1,自引:0,他引:1
R T Greyson-Fleg B Jones E K Fishman S R Hamilton S S Siegelman 《The Journal of computed tomography》1986,10(2):175-181
The computed tomography findings in two cases of gastrointestinal superinfection by opportunistic organisms in acquired immune deficiency syndrome are presented. Findings included thickening of the mucosal folds and the bowel wall in the small intestine and colon associated with cytomegalovirus and cryptosporidiosis. These cases indicate that it is important to look carefully at the gastrointestinal tract when performing computed tomography in this group of patients. Unsuspected bowel pathology may be demonstrated, or disease may be confirmed in clinically suspected cases. 相似文献
63.
Stanford''s two decades of success in linking medical informatics and health services research in both training and investigational activities reflects advantageous geography and history as well as natural synergies in the two areas. Health services research and medical informatics at Stanford have long shared a quantitative, analytic orientation, along with linked administration, curriculum, and clinical activities. Both the medical informatics and the health services research curricula draw on diverse course offerings throughout the university, and both the training and research overlap in such areas as outcomes research, large database analysis, and decision analysis/decision support. The Stanford experience suggests that successful integration of programs in medical informatics and health services research requires areas of overlapping or synergistic interest and activity among the involved faculty and, hence, in time, among the students. This is enhanced by a mixture of casual and structured contact among students from both disciplines, including social interactions. The challenges to integration are how to overcome any geographic separation that may exist in a given institution; the proper management of relationships with those sub-areas of medical informatics that have less overlap with health services research; and the need to determine how best to exploit opportunities for collaboration that naturally occur.Training in medical informatics and health services research has been closely linked at Stanford University for almost two decades. Although the close linkage was deliberate, it was facilitated by historical circumstances, in particular the common academic structures in which both programs arose. In this paper, we describe some of that rationale and history, identifying the areas of overlap that we have pursued in coordinating the training opportunities for graduate students and fellows in both areas of study. As we shall note, the synergies have been great, and in some cases trainees have collaborated closely on research while also taking some of the same courses. We believe that these interactions can be a model for the design of training programs that encourage scholarly interactions between medical informatics and health services research. Although our initial charge was to describe both the successes and failures in integrating the programs, we found that we could not identify any outright failures and that it would be better to delineate the complexities and challenges that we have faced in bringing together these two disciplines. 相似文献
64.
65.
66.
67.
Ravinder K. Mittal MD Barry N. Siskind MD Michio Hongo MD M. Wayne Flye MD Richard W. McCallum MD 《Digestive diseases and sciences》1986,31(4):379-384
Three patients with dysphagia caused by compression of the distal esophagus by a tortuous nonaneurysmal atherosclerotic aorta are described. All three patients were elderly women; systemic hypertension and cardiomegaly were present in two patients. Barium studies of the esophagus showed displacement and compression of the distal esophagus by the thoracic aorta. Debilitating dysphagia was treated surgically in one patient. The other two patients had milder symptoms and were managed conservatively. Esophageal manometry in these three patients showed superimposed pulsations and elevated intraluminal pressure just proximal to the lower esophageal sphincter. To evaluate the significance of these manometric findings and their correlation with clinical symptoms, we reviewed manometric tracings in 47 normal subjects. Ten of these subjects had an elevation of baseline intraluminal esophageal pressure as a result of superimposed vascular pulsations. We conclude that (1) compression of the distal esophagus by a tortuous atherosclerotic aorta in the appropriate setting can lead to clinically significant dysphagia and (2) a manometric finding of vascular compression of the esophagus does not necessarily correlate symptomatic dysphagia. 相似文献
68.
69.
AIMS: To assess the relationship between neighbourhood deprivation and the rate of gestational diabetes mellitus (GDM) using routinely collected data from a clinical information system, in Plymouth, UK. METHODS: Between 1 January 1996 and 31 December 1997, 3933 women residing within the Plymouth Primary Care Trust (PCT) were screened for GDM using indices of neighbourhood deprivation and prevalence of GDM. Areas (n = 43) were classified according to the Townsend index, measuring material deprivation. Pregnant women with and without GDM were compared. RESULTS: The prevalence of GDM was 1.7%[95%, confidence interval (CI) 1.20, 2.11]. The prevalence of GDM ranged from 1.05% (95% CI 0.60, 1.70) in the most deprived to 2.10% (95%, CI 1.34, 3.13), in the least deprived neighbourhood. Crude rates decreased by 50%[relative prevalence (RP) (95% CI) 0.50 (0.27, 0.94); P = 0.06] amongst those living in the most-deprived compared with those living in the least-deprived areas. Using a stepwise binary logistic regression model, older age at delivery significantly increased the risk of developing GDM. [RP (95%, CI) 1.09, (1.04, 1.13)]. Townsend deprivation score had no significant independent association with GDM when other covariates were considered. CONCLUSION: These data suggest that the neighbourhood context in which women live has no impact on the risk of GDM. Diabet. 相似文献
70.
Local mucosal immunoglobulin E production: does allergy exist in non‐allergic rhinitis? 总被引:2,自引:0,他引:2
In this review, we critically evaluate the evidence for local IgE production in allergic rhinitis mucosa and the concept of local allergy in non-atopic idiopathic rhinitis. Significantly, fewer studies have focused on the disease pathways associated with non-allergic rhinitis compared with their allergic counterparts. Recently, there's been a revival of the hypothesis concerning the existence of local tissue-specific allergic disease confined to the nasal mucosa of some systemically non-atopic rhinitis subjects. Providing the evidence for local mucosal IgE production in allergic rhinitis is a pre-requisite to reviewing its existence in non-allergic rhinitis. In addition, practical and theoretical approaches useful in the detection of allergy in non-allergic rhinitis will be discussed. Furthermore, successful therapeutic regimens used in the treatment of non-allergic rhinitis will be examined as these could provide an insight into the underlying pathophysiology of this common but poorly understood disease. 相似文献