全文获取类型
收费全文 | 43619篇 |
免费 | 2510篇 |
国内免费 | 663篇 |
专业分类
耳鼻咽喉 | 203篇 |
儿科学 | 2160篇 |
妇产科学 | 3053篇 |
基础医学 | 3504篇 |
口腔科学 | 473篇 |
临床医学 | 4192篇 |
内科学 | 11027篇 |
皮肤病学 | 653篇 |
神经病学 | 2802篇 |
特种医学 | 986篇 |
外国民族医学 | 1篇 |
外科学 | 4640篇 |
综合类 | 2903篇 |
现状与发展 | 3篇 |
一般理论 | 11篇 |
预防医学 | 3669篇 |
眼科学 | 1139篇 |
药学 | 1967篇 |
4篇 | |
中国医学 | 421篇 |
肿瘤学 | 2981篇 |
出版年
2023年 | 357篇 |
2022年 | 350篇 |
2021年 | 538篇 |
2020年 | 482篇 |
2019年 | 258篇 |
2018年 | 704篇 |
2017年 | 679篇 |
2016年 | 833篇 |
2015年 | 798篇 |
2014年 | 802篇 |
2013年 | 1123篇 |
2012年 | 2711篇 |
2011年 | 3314篇 |
2010年 | 1311篇 |
2009年 | 1204篇 |
2008年 | 3050篇 |
2007年 | 2973篇 |
2006年 | 2687篇 |
2005年 | 2858篇 |
2004年 | 3260篇 |
2003年 | 3316篇 |
2002年 | 2573篇 |
2001年 | 1943篇 |
2000年 | 709篇 |
1999年 | 711篇 |
1998年 | 728篇 |
1997年 | 571篇 |
1996年 | 486篇 |
1995年 | 348篇 |
1994年 | 421篇 |
1993年 | 394篇 |
1992年 | 457篇 |
1991年 | 436篇 |
1990年 | 385篇 |
1989年 | 351篇 |
1988年 | 279篇 |
1987年 | 276篇 |
1986年 | 256篇 |
1985年 | 183篇 |
1984年 | 128篇 |
1983年 | 123篇 |
1982年 | 113篇 |
1981年 | 113篇 |
1980年 | 105篇 |
1979年 | 92篇 |
1978年 | 77篇 |
1977年 | 75篇 |
1976年 | 65篇 |
1975年 | 85篇 |
1973年 | 86篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
John McMahon RMN BA Scottish Home Health Department Nursing Research Fellow Staff Nurse Barry T Jones BSc PhD Senior Lecturer 《Journal of advanced nursing》1992,17(2):173-186
Despite being constantly cited as a critical intervening variable in the recovery from alcohol problems, there is a paucity of literature on client motivation. This paper reviews the current literature which impacts on motivation and its importance in treatment and develops in a stepwise manner the revised expectancy/motivation hypothesis, tentatively explaining both motivation and denial as a natural process in behavioural change. Because of the revised expectancy/motivation hypothesis' distinctly defined stages which closely relate to the process of nursing and the qualitative and quantitative measurement it entails which the nursing process demands, it offers a particularly appropriate model for treatment within nurse practice. 相似文献
23.
24.
25.
D G Pipelleers P A in 't Veld M A Pipeleers-Marichal W Gepts M van de Winkel 《Diabetes》1987,36(7):872-876
In the normal rat pancreas, only few islet cells express MHC-class II antigens. Their nature and function has not yet been elucidated. We report a method for the purification of Ia-positive islet cells by fluorescence-activated cell sorting. The isolated mononuclear cells appear of nonendocrine origin but contain vacuoles with partially digested secretory vesicles. Both insulin- and glucagon-immunoreactive granules were identified in these vacuoles of varying size and composition. It is suggested that at least part of the rat islet cells with class II antigen expression can exhibit phagocytotic properties leading to the uptake of fragments from damaged endocrine cells. This functional characteristic may implicate this particular islet cell type in the pathology of the endocrine pancreas in type I diabetes. 相似文献
26.
K B Ates S Boyacio?lu I Ta? A Gencer G Temu?in B Sahin 《Gastrointestinal radiology》1991,16(2):178-180
Bleeding into a pancreatic pseudocyst is a rare but life-threatening entity. Early diagnosis is crucial in its management. There are reports suggesting that computed tomography (CT), scintigraphy, endoscopic retrograde cholangiopancreatography (ERCP), and angiography could be the diagnostic maneuvers. In this report, we present a case of arterial bleeding into a pancreatic pseudocyst, which was diagnosed by the turbulent echo-currents seen in real-time ultrasonography. 相似文献
27.
28.
R. Nickel S. Lau B. Niggemann C. Sommerfeld U. Wahn the German Multicenter Allergy Study Group 《Clinical and experimental allergy》2002,32(9):1274-1277
BACKGROUND: Bronchial responsiveness (BR) to histamine or methacholin is a common finding in adult non-asthmatic patients with allergic rhinitis. OBJECTIVE: We tested whether BR is also present in children with a comparatively short history of allergic rhinitis in a paediatric cohort. METHODS: We performed pulmonary function tests and histamine challenges in a total of 654 children (age 7 years, participants of the German Multicenter Allergy Study) and compared PC20 FEV1 values in children with asthma, allergic rhinitis, asymptomatic allergic sensitization and non-atopic controls. RESULTS: Most pronounced BR to histamine was observed in allergic asthmatics (n = 28), irrespective of the presence or absence of allergic rhinitis. Furthermore, PC(20)FEV(1) values in non-asthmatic children with allergic rhinitis (n = 24) were not significantly different from those seen in asymptomatic atopic (n = 54) or non-atopic controls (n = 92). CONCLUSIONS: In contrast to adult study populations, 7-year-old non-asthmatic children with allergic rhinitis do not show a higher degree of BR than asymptomatic atopic or non-atopic controls. Therefore, secondary preventive measures in non-asthmatic children with allergic rhinitis (such as regular local anti-inflammatory therapy or specific immunotherapy) should be studied and applied more intensely to prevent bronchial hyper-responsiveness (BHR) and asthma in this high-risk group. 相似文献
29.
Andrea Frudinger Research Registrar Clive I. Bartram Consultant John A. D. Spencer Consultant Michael A. Kamm Consultant 《BJOG : an international journal of obstetrics and gynaecology》1997,104(9):1009-1013
Objective To assess the relation between perineal inspection and sphincter integrity in parous women.
Design Prospective observational study.
Setting District general hospital.
Population Fifty-seven consecutive parous women attending a gynaecology clinic for problems unrelated to the pelvic floor.
Methods A detailed history of bowel function and mode of delivery obtained; the perineum inspected to determine the presence and position of scarring, and anal endosonography performed.
Results In 19 women with an intact perineum on inspection, endosonography showed perineal scarring in five, with both perineal and sphincter scarring in three. Four had urge faecal incontinence. Three patients had a perineal tear only on inspection, but this group was too small for analysis and was discounted. Nine had an episiotomy scar only. Endosonography demonstrated perineal scarring in four, and combined perineal and sphincter scarring in two; one woman in this group had urge faecal incontinence. Twenty-six women had episiotomy and perineal tears on inspection. Endosonography revealed underlying perineal scarring in five women, with combined perineal and sphincter scarring in 14; six women in this group had urge faecal incontinence and one passive incontinence for flatus. Sonographically the scarring was anterior and circumferential rather than radial, and mostly left-sided, whereas on inspection episiotomy and perineal scarring were right sided.
Conclusions A normal perineum on clinical examination does not exclude underlying sphincter damage. The incidence of sphincter damage increases significantly when an episiotomy scar is associated with a perineal tear. 相似文献
Design Prospective observational study.
Setting District general hospital.
Population Fifty-seven consecutive parous women attending a gynaecology clinic for problems unrelated to the pelvic floor.
Methods A detailed history of bowel function and mode of delivery obtained; the perineum inspected to determine the presence and position of scarring, and anal endosonography performed.
Results In 19 women with an intact perineum on inspection, endosonography showed perineal scarring in five, with both perineal and sphincter scarring in three. Four had urge faecal incontinence. Three patients had a perineal tear only on inspection, but this group was too small for analysis and was discounted. Nine had an episiotomy scar only. Endosonography demonstrated perineal scarring in four, and combined perineal and sphincter scarring in two; one woman in this group had urge faecal incontinence. Twenty-six women had episiotomy and perineal tears on inspection. Endosonography revealed underlying perineal scarring in five women, with combined perineal and sphincter scarring in 14; six women in this group had urge faecal incontinence and one passive incontinence for flatus. Sonographically the scarring was anterior and circumferential rather than radial, and mostly left-sided, whereas on inspection episiotomy and perineal scarring were right sided.
Conclusions A normal perineum on clinical examination does not exclude underlying sphincter damage. The incidence of sphincter damage increases significantly when an episiotomy scar is associated with a perineal tear. 相似文献
30.
Coppo R; Cirina P; Amore A; Sinico R; Radice A; Rollino C; the Italian Group of Renal Immunopathology Collaborative Study on Henoch-Schonlein purpura in adults f; children i 《Nephrology, dialysis, transplantation》1997,12(11):2269-2276
Background: The presence and the pathogenetic role of
circulating IgA reacting with neutrophil cytoplasmic antigens (IgA-ANCA) in
patients with Henoch-Schonlein purpura (HSP) is still debated. This study
was aimed to investigate some characteristics of serum IgA and
macromolecular IgA in HSP patients, focusing on IgA-ANCA.
Methods: Eighty-seven HSP patients with biopsy proved
renal involvement (51 adults and 36 children) enrolled in a multicentre
study of the Italian Group of Immunopathology were investigated.
Results: Significantly high levels of IgA immune
complexes were found in both adults (P <0.05) and children (P
<0.01), while the binding of IgA to jacalin, was significantly low
in children with HSP (P <0.01) only. Two series of ELISA were done
for IgA-ANCA, in two different laboratories. Increased binding to PMN crude
extracts (P <0.01) without any modification in IgA binding to
proteinase 3 was found by either specific ELISA. Conversely, the binding of
IgA to myeloperoxidase (MPO) was found to be significantly (P <0.05)
increased with positive values in 25% of patients by one assay only. Three
of four sera with positive IgA-MPO ANCA exhibited binding in Western-blot
studies with the MPO preparation used in ELISA to a 28-kDa species.
D-galactose and N-acetyl-glucosamine decreased the binding of serum IgA to
MPO more in HSP than in controls (P <0.05).
Conclusions: The conflicting reports on IgA-ANCA may
reflect some atypical characteristics of the reaction which can be detected
only by some ELISAs. We suggest that not an antigen-antibody reaction but a
lectinic interaction due to abnormal composition of IgA carbohydrate side
chains may account for the IgA-ANCA reaction in patients with HSP
nephritis. 相似文献