全文获取类型
收费全文 | 1918篇 |
免费 | 115篇 |
国内免费 | 3篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 108篇 |
妇产科学 | 22篇 |
基础医学 | 234篇 |
口腔科学 | 47篇 |
临床医学 | 160篇 |
内科学 | 506篇 |
皮肤病学 | 67篇 |
神经病学 | 60篇 |
特种医学 | 277篇 |
外科学 | 194篇 |
综合类 | 17篇 |
预防医学 | 115篇 |
眼科学 | 12篇 |
药学 | 87篇 |
中国医学 | 4篇 |
肿瘤学 | 123篇 |
出版年
2023年 | 6篇 |
2022年 | 12篇 |
2021年 | 45篇 |
2020年 | 18篇 |
2019年 | 28篇 |
2018年 | 57篇 |
2017年 | 55篇 |
2016年 | 31篇 |
2015年 | 31篇 |
2014年 | 42篇 |
2013年 | 61篇 |
2012年 | 75篇 |
2011年 | 55篇 |
2010年 | 75篇 |
2009年 | 68篇 |
2008年 | 76篇 |
2007年 | 61篇 |
2006年 | 60篇 |
2005年 | 58篇 |
2004年 | 66篇 |
2003年 | 41篇 |
2002年 | 34篇 |
2001年 | 46篇 |
2000年 | 40篇 |
1999年 | 36篇 |
1998年 | 59篇 |
1997年 | 74篇 |
1996年 | 58篇 |
1995年 | 50篇 |
1994年 | 63篇 |
1993年 | 63篇 |
1992年 | 28篇 |
1991年 | 25篇 |
1990年 | 36篇 |
1989年 | 51篇 |
1988年 | 49篇 |
1987年 | 40篇 |
1986年 | 38篇 |
1985年 | 35篇 |
1984年 | 13篇 |
1983年 | 24篇 |
1982年 | 17篇 |
1981年 | 19篇 |
1980年 | 23篇 |
1979年 | 8篇 |
1978年 | 13篇 |
1977年 | 12篇 |
1976年 | 10篇 |
1975年 | 19篇 |
1973年 | 7篇 |
排序方式: 共有2036条查询结果,搜索用时 724 毫秒
1.
2.
Preliminary evidence for a role of apolipoprotein E alleles in identifying haemodialysis patients at high vascular risk 总被引:1,自引:0,他引:1
Olmer M; Renucci JE; Planells R; Bouchouareb D; Purgus R 《Nephrology, dialysis, transplantation》1997,12(4):691-693
Conventional risk factors have very low predictive power in identifying
haemodialysis patients at high risk of vascular accidents. A role for
apolipoprotein E isotypes was looked for in a small, but rigorously
defined, cohort of longterm haemodialysis patients. In individuals with
high vascular risk, as identified by higher common carotid intima/media
thickness, we found an excess of apolipoprotein E4 alleles. This
preliminary result requires confirmation in large patient cohorts.
相似文献
3.
4.
5.
6.
M Oca?a E Del Pozo M Barrios L I Robles J M Baeyens 《European journal of pharmacology》1990,186(2-3):377-378
7.
J L Pérez Arellano N M Barrios González T Martín Domínguez M L Sánchez Benítez de Soto A Jiménez López 《Journal of investigational allergology & clinical immunology》1992,2(4):219-228
Experimental models of hypersensitivity pneumonitis are important tools for the study of the pathogenesis of this disease. In this paper we review the characteristics of the main animal models developed until now. The HP models in rats seem to be particularly appropriate for studying pigeon fancier's disease and the HP induced by chemicals, as well as for studying mediators of acute lesions induced by immunocomplexes. However, the HP models developed in rats are of less value in the evaluation of other aspects of the pathogenesis of this clinical entity in humans. The murine models of HP offer several advantages: the ease and simplicity of intranasal administration, the ability to produce acute and subacute pulmonary lesions similar to those found in humans, the possibility of reproducing lesions similar to those of nonaffected exposed subjects and the possibility of pharmacologically modulating the process. Their disadvantages lie in the different pulmonary lymphocyte response and the difficulty in reproducing a model of chronic fibrosis. The HP models in rabbits are extraordinarily useful for evaluating the immunological mechanisms through which subjects repeatedly exposed to the antigen do not develop clinical manifestations. However, the rabbit has several immunological differences when compared to humans, and the effect of some immunomodulators in this animal is different. The models of HP in guinea-pigs have as advantages the ease in handling the animals, the possibility of pharmacological manipulation, and the ability to induce an acute phase that is very similar to that observed in humans. The drawback, however, is the low lymphocyte response and the striking eosinophilic reaction that contrast with the bronchoalveolar data found in HP in humans. In conclusion, there is no ideal model to reproduce all the findings observed in humans, suggesting that the experimental animal and the method of developing HP should be selected on the basis of concrete research aims. 相似文献
8.
Hodgkin disease: CT of the thymus 总被引:2,自引:0,他引:2
The computed tomography (CT) scans in two groups of patients with Hodgkin disease were reviewed to determine the frequency of thymic enlargement. In 50 CT scans from 50 patients with evidence of thoracic disease on CT scans who were examined for primary staging, the thymus was enlarged in 15 of 50 (30%). Fifty CT scans were obtained from 44 patients at the time of 50 separate episodes of known or suspected relapse. Relapse occurred in the mediastinum in 12 episodes, lung parenchyma in five, and both sites in one. Thymic enlargement thought to be due to involvement by disease was present in seven of 18 (38%). Mediastinal disease was associated with thymic enlargement in all but one patient in whom a thymic cyst developed after radiation therapy. Differentiation of thymic enlargement from enlarged superior mediastinal lymph nodes was easily made in all but two patients. Thymic enlargement in the absence of lymph node enlargement may indicate a different disease, since isolated Hodgkin disease of the thymus is uncommon. Primary thymic tumor should be considered initially, whereas after treatment, rebound hyperplasia of the thymus may be the cause of enlargement. 相似文献
9.
Solitary bronchioloalveolar carcinoma: CT criteria 总被引:14,自引:0,他引:14
Kuhlman JE; Fishman EK; Kuhajda FP; Meziane MM; Khouri NF; Zerhouni EA; Siegelman SS 《Radiology》1988,167(2):379-382
The computed tomographic (CT) scans of 30 patients with solitary bronchioloalveolar carcinoma were reviewed. Common features at CT included the peripheral or subpleural location of a pulmonary mass (25 cases), pseudocavitation (18 cases), heterogeneous attenuation (17 cases), irregular margins forming a star pattern (22 cases), and pleural tags (21 cases). Using these CT criteria, four independent observers attempted to identify cases of bronchioloalveolar carcinoma from a larger sample of lung cancers and benign lesions by categorizing a series of test cases into four probability categories. Although the bronchioloalveolar carcinomas were correctly ranked in the two highest probability categories 75% of the time (in 45 of 60 cases), there was considerable overlap with other lung lesions, particularly with adenocarcinoma and large cell undifferentiated carcinoma. However, even though the typical features of bronchioloalveolar carcinoma are not invariable or highly specific, they are characteristic enough to suggest the diagnosis. 相似文献
10.
Carlos Villas Rodrigo Martinez-Peric Ricardo Preite Raul H. Barrios 《Acta orthopaedica》1994,65(6):620-622
With a mean follow-up of 3 (1-6) years, we report on 21 patients who underwent multiple level cervical fusion, using autologous iliac crest grafts. Dis-cectomies were performed in 14 patients and cor-pectomies in another 7. Instrumentation was used in all patients with colectomies and in 2 patients who underwent 2-level and 3-level discectomies. Non-union occurred in 1 patient at 1 level. Graft displacement requiring reoperation was observed in 2 patients with massive corpectomies, in 1 of them as a consequence of trauma. In both patients complete bony fusion was obtained after reoperation and no other complications were observed. We conclude that the success rate with multiple-level fusion is comparable to that of single-level fusion when adequate fixation is achieved. 相似文献