全文获取类型
收费全文 | 12641篇 |
免费 | 830篇 |
国内免费 | 48篇 |
专业分类
耳鼻咽喉 | 188篇 |
儿科学 | 291篇 |
妇产科学 | 236篇 |
基础医学 | 1812篇 |
口腔科学 | 1183篇 |
临床医学 | 1021篇 |
内科学 | 2777篇 |
皮肤病学 | 350篇 |
神经病学 | 881篇 |
特种医学 | 362篇 |
外国民族医学 | 1篇 |
外科学 | 1446篇 |
综合类 | 69篇 |
一般理论 | 6篇 |
预防医学 | 1286篇 |
眼科学 | 204篇 |
药学 | 864篇 |
中国医学 | 82篇 |
肿瘤学 | 460篇 |
出版年
2023年 | 110篇 |
2022年 | 287篇 |
2021年 | 451篇 |
2020年 | 316篇 |
2019年 | 430篇 |
2018年 | 482篇 |
2017年 | 343篇 |
2016年 | 382篇 |
2015年 | 396篇 |
2014年 | 553篇 |
2013年 | 683篇 |
2012年 | 966篇 |
2011年 | 1029篇 |
2010年 | 588篇 |
2009年 | 468篇 |
2008年 | 685篇 |
2007年 | 746篇 |
2006年 | 588篇 |
2005年 | 574篇 |
2004年 | 463篇 |
2003年 | 386篇 |
2002年 | 368篇 |
2001年 | 280篇 |
2000年 | 278篇 |
1999年 | 207篇 |
1998年 | 84篇 |
1997年 | 70篇 |
1996年 | 59篇 |
1995年 | 54篇 |
1994年 | 50篇 |
1993年 | 39篇 |
1992年 | 89篇 |
1991年 | 85篇 |
1990年 | 89篇 |
1989年 | 64篇 |
1988年 | 66篇 |
1987年 | 73篇 |
1986年 | 61篇 |
1985年 | 54篇 |
1984年 | 57篇 |
1983年 | 43篇 |
1982年 | 37篇 |
1980年 | 22篇 |
1979年 | 33篇 |
1978年 | 28篇 |
1970年 | 23篇 |
1969年 | 20篇 |
1967年 | 25篇 |
1966年 | 23篇 |
1965年 | 21篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
2.
Iclea Rocha Gama Euclides Marinho Trindade-Filho Suzana Lima Oliveira Nassib Bezerra Bueno Isabelle Tenório Melo Cyro Rego Cabral-Junior Elenita M. Barros Jaqueline A. Galvão Wanessa S. Pereira Raphaela C. Ferreira Bruna R. Domingos Terezinha da Rocha Ataide 《Metabolic brain disease》2015,30(1):93-98
3.
4.
Jorge Guardado Carlos Cotrim Otília Sim?es Sofia Almeida Mário Ialá Luís Lopes Hélder Pereira Manuel Carrageta 《Revista portuguesa de cardiologia》2006,25(4):409-415
INTRODUCTION: Transesophageal echocardiography (TEE) has become increasingly useful in the study of patients with suspected pulmonary thromboembolism. OBJECTIVE: The aim of this study was to prospectively evaluate the usefulness of TEE in the study of the distal part of the left pulmonary artery (LPA) as well as the influence of this procedure on total echocardiographic exam duration. METHODOLOGY: A prospective study in two groups of consecutive patients referred for TEE with a one- year interval between evaluation of Group A: 33 patients, 17 male, mean age 54 +/- 24 years, and Group B: 42 patients, 20 male, mean age 48 +/- 27 years (p = NS). The procedure was considered long when it took more than 3 min to evaluate the distal part of the LPA. RESULTS: In group A we were able to visualize the distal part of the LPA in 24 patients (73%) without significant prolongation of total exam duration in 16 patients (48% of group A). In one of the patients with suspected pulmonary thromboembolism thrombi were only observed in the distal part of the LPA. In group B we were able to visualize the distal part of the LPA in 36 patients (86%) without significant prolongation of total exam duration in 26 patients (61% of group B). CONCLUSIONS: 1. Visualization of the distal part of the LPA was possible in more patients, and with TEE time prolongation in less patients, in group B. These differences can be accounted for by the training of the operator in this technique. 2. The importance of visualization of this part of the LPA in guiding treatment in the subset of patients with pulmonary thromboembolism confirms the usefulness of this specific procedure. 相似文献
5.
C Pereira Alves 《Phlébologie》1989,42(4):585-589
Varitest plethysmography is a non-invasive diagnostic method of venous insufficiency based on the study of the emptying of leg veins by flexion movements and their subsequent filling. The Varitest records the curves and measurements of these two stages. The physiological bases of the test and its technique are presented. Our experience, following the first few cases, enabled us to identify three main groups of patients:--Patients presenting chronic symptoms, in whom the clinical examination was negative or not obvious;--Patients presenting a problem of differential diagnosis with a deep/superficial or mixed chronic venous insufficiency. It also enabled us to specify the results of the treatments. According to our results, Varitest is a simple, easy to reproduce method, presenting a sensitivity and specificity with regard to the clinical symptoms and the Doppler, of approximately 80%. Its negative aspects are the poor collaboration of the patients or their inability to be available in order to study acute venous thromboses. 相似文献
6.
A Todo-Bom A Mota Pinto V Alves S Vale Pereira M Santos Rosa 《Journal of investigational allergology & clinical immunology》2007,17(2):107-112
BACKGROUND: Asthma is a chronic inflammatory disorder of the airways. The persistence of airway inflammation depends on a decrease in apoptosis of T lymphocytes and eosinophils and survival of these activated cells. T lymphocytes expressing gamma delta receptors can be identified in human lungs and play an important role in immune defence against pathogens and in the regulation of chronic inflammation. Aging is associated with evidence of some immune dysregulation. OBJECTIVE: The aim of this study was to analyze the apoptosis receptors of T lymphocytes in long-lasting asthma, to establish their correlation with activation markers such as CD25+ and human leukocyte antigen (HLA)-DR+, and to analyze the gama delta T cell expression in this disease. METHODS: A group of 64 individuals (group A) who had had asthma for more than 30 years (mean age [+/-SD] 72 +/- 5 years) and 61 healthy individuals acting as controls--group B with 41 individuals (mean age 79 +/- 7 years) and group C with 20 individuals (mean age 38 +/- 12 years) were included in the study. All subjects underwent clinical evaluation and spirometric testing. Peripheral blood cells were stained with monoclonal antibodies anti-CD3, anti-CD4, anti-CD8, anti-CD25, anti-TCR gamma delta, anti-HLA-DR and anti-CD95. Statistical comparisons were performed between the asthmatics and the elderly control group and between the elderly control group and the adult control group. RESULTS: The average percentage of predicted forced expiratory volume in the first second was 73.6 gamma delta 25.3. The mean values of T cell receptors for asthma group A vs elderly control group B vs adult control group C respectively, were the following: CD3, 74.9+/-7 vs. 74.8 +/- 8.8 (P=ns) vs. 76.7 +/- 4.2 (P=ns); CD4, 48.8 +/- 8.7 vs. 43.5 +/- 10.2 (P=ns) vs. 44.8 +/- 3.8 (P=ns); CD8, 23.3 +/- 7.9 vs. 25.7 +/- 10.2 (P=ns) vs. 25.6 +/- 4.5 (P=ns); CD25, 14.3 +/- 5.9 vs. 22.4 +/- 7.8 (P = .0001) vs. 5.5 +/- 2.4 (P = .0001); TCR gamma delta, 2.8 +/- 2.1 vs. 4.1 +/- 3.3 (P < .05) vs. 4.6 +/- 2.1 (P=ns); HLA-DR, 18.4 +/- 9.2 vs. 17.8 +/- 5.9 (P=ns) vs. 15.4 +/- 5.1 (P=ns) and CD95, 49.3 +/- 13.7 vs. 52.6 +/- 12.1 (P=ns) vs. 13.8 +/- 10.8 (P = .0001). CONCLUSIONS: The immunological and inflammatory changes related to ageing may cause an increase in CD95 and CD25 T cell expression. In asthma, blood cells may express increased activation and apoptosis markers but in elderly patients taking steroids, these receptors remain within normal ranges. The number of gamma delta T cells may be lower in long-lasting asthma, and have a limited modulatory effect on allergic inflammatory reactions. The evaluation of patients with long-lasting asthma should take into account the immunological and inflammatory changes present in the elderly in order to avoid results being misinterpreted. 相似文献
7.
Sérgio Carreir?o Leandro Pereira Marcelo Wilson Rocha Almeida 《Aesthetic plastic surgery》2009,33(3):445-451
Surgical procedures for the mammary region currently are assuming an important role in body-contouring surgery. Enhancement
of results is a constant challenge to the plastic surgeon. A simple and efficient maneuver for resection of the breast’s lateral
pole based on the mammoplasty technique of Professor Ivo Pitanguy is described.
This study realized at the Private Clinic Sérgio Carreir?o, Rio de Janeiro, RJ, Brazil. 相似文献
8.
9.
Rosangela Saga Kamikawa Marlene Fenyo Pereira Angela Fernandes Maria Inês Meurer 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2006,101(3):374-378
OBJECTIVE: To determine the location in soft tissues of the calcifications, similar to calcified carotid atheromas, that can be observed radiographically in the cervical region in panoramic radiographs. STUDY DESIGN: In each anatomic cadaver specimen preserved in formol, consisting of the head and neck, radiopaque spheres (made from gutta-percha) were positioned in anatomic structures of the cervical region that can be sites of calcification. For each anatomic structure marked in this way, panoramic radiography was performed, consisting of 17 radiographs. The images obtained were analyzed by 24 examiners who indicated which radiographs, in their opinion, presented the radiopaque reference projected in the region of bifurcation of the carotid artery. Analysis of 2 proportions from agreement and disagreement was used to determine radiopacities that could be confused in panoramic radiographs with calcified atheromas in the carotid artery. RESULTS: The results showed that 75% (18) of the examiners correctly indicated the reference in the bifurcation of the carotid artery and 79.2% (19) indicated a triticeous cartilage as calcified atheroma of the carotid artery. CONCLUSIONS: Calcified atheromas of the carotid artery are not the only features that can produce radiopaque images lateral to the panoramic radiograph; the presence of calcification in the triticeous cartilage also can induce an erroneous diagnosis of calcified carotid atheroma. 相似文献
10.
M. Filippi A. Campi V. Martinelli C. Pereira G. Scotti G. Comi 《Acta neurologica Scandinavica》1995,92(2):178-182
Transitional progressive multiple sclerosis (MS) is quite an unusual form of presentation and course of the disease. A case with this progressive form is presented and brain MRI and MTI findings are discussed in relation to the possible insight they may provide for understanding the mechanisms that determine progressive disability in MS. 相似文献