全文获取类型
收费全文 | 83101篇 |
免费 | 7089篇 |
国内免费 | 3933篇 |
专业分类
耳鼻咽喉 | 840篇 |
儿科学 | 890篇 |
妇产科学 | 1401篇 |
基础医学 | 11757篇 |
口腔科学 | 1883篇 |
临床医学 | 8968篇 |
内科学 | 14487篇 |
皮肤病学 | 1236篇 |
神经病学 | 5371篇 |
特种医学 | 2709篇 |
外国民族医学 | 27篇 |
外科学 | 10099篇 |
综合类 | 9242篇 |
现状与发展 | 6篇 |
一般理论 | 7篇 |
预防医学 | 4731篇 |
眼科学 | 2514篇 |
药学 | 8187篇 |
26篇 | |
中国医学 | 2629篇 |
肿瘤学 | 7113篇 |
出版年
2024年 | 123篇 |
2023年 | 756篇 |
2022年 | 1787篇 |
2021年 | 2291篇 |
2020年 | 1686篇 |
2019年 | 1807篇 |
2018年 | 2205篇 |
2017年 | 1994篇 |
2016年 | 1829篇 |
2015年 | 2516篇 |
2014年 | 3091篇 |
2013年 | 3054篇 |
2012年 | 4410篇 |
2011年 | 4559篇 |
2010年 | 2734篇 |
2009年 | 2398篇 |
2008年 | 3367篇 |
2007年 | 3457篇 |
2006年 | 3381篇 |
2005年 | 3272篇 |
2004年 | 2330篇 |
2003年 | 2167篇 |
2002年 | 2028篇 |
2001年 | 5221篇 |
2000年 | 5118篇 |
1999年 | 4604篇 |
1998年 | 1877篇 |
1997年 | 1485篇 |
1996年 | 993篇 |
1995年 | 859篇 |
1994年 | 746篇 |
1993年 | 623篇 |
1992年 | 2131篇 |
1991年 | 1864篇 |
1990年 | 1696篇 |
1989年 | 1611篇 |
1988年 | 1415篇 |
1987年 | 1276篇 |
1986年 | 1141篇 |
1985年 | 950篇 |
1984年 | 608篇 |
1983年 | 487篇 |
1982年 | 255篇 |
1981年 | 197篇 |
1980年 | 149篇 |
1979年 | 288篇 |
1978年 | 77篇 |
1974年 | 75篇 |
1973年 | 95篇 |
1972年 | 71篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
When blood flow through the internal and external carotid arteries is completely interrupted by ipsilateral common carotid artery occlusion, the arterial orbital circulation may be more compromised than the brain supply. We studied a pure and extreme example of this situation in a patient who presented with acute orbital infarction, but no cerebral ischemia on clinical, CT and single-photon emission computerized tomography (SPECT) grounds. Ipsilateral blindness corresponded to retinal, choroidal and optic nerve infarction. The pattern of ophthalmoplegia, with relative sparing of adduction, was more compatible with a muscle than a nerve dysfunction, but a reactive dilated pupil, corneal anesthesia, and orbital pain suggested that the intraorbital branches of the ocular motor nerves and ophthalmic division of the trigeminal nerve were not spared. In addition, signs of widespread ocular ischemia were present. Sequential examinations documented the evolution pattern over 1 year. The absence of an orbital collateral supply from the contralateral external carotid and muscular cervical arteries systems, which contrasted with an adequate middle cerebral artery supply via the contralateral internal carotid artery, may explain this isolated and complete form of orbital ischemia due to common carotid artery occlusion. 相似文献
32.
Delta hepatitis virus infection in China 总被引:1,自引:0,他引:1
D Q Wang H H Cheng G Y Minuk L H Liu C M Anand T C Stowe H X Wang D C Ying Y R Tu K A Buchan 《International journal of epidemiology》1987,16(1):79-83
To assess the prevalence, epidemiological features and prognostic implications of hepatitis D (Delta) in Sichuan Province, The People's Republic of China, 649 sera (515 from HBsAg positive patients and 134 from HBsAg negative subjects) were tested by radioimmunoassay (RIA) for antibody to the hepatitis D virus (anti-HD). Forty-seven sera (7.2%) showed some degree of reactivity. Serial dilutions of these sera indicated that prozoning was not responsible for the equivocal results. Thirty-four of the 47 sera were submitted under code to a second laboratory for independent analysis. According to those results anti-HD antibodies were detected in four of these sera. The overall prevalence of anti-HD in the HBsAg positive patients therefore was 0.8% (4/515). On the basis of clinical, biochemical and histological data 427 HBsAg positive sera were further divided into acute Type B hepatitis, chronic Type B hepatitis, healthy carrier state and hepatocellular carcinoma (HCC) subgroups. Two of 65 (3.1%) anti-HD positive sera belonged to the acute Type B hepatitis group; one of 104 (0.9%), the chronic Type B hepatitis group and one of 246 (0.4%), the healthy carrier group. No antibody was detected in sera from 12 HBsAg positive HCC patients. All HBsAg negative patients were negative for anti-HD antibody. The results of this study indicate that despite a high prevalence of hepatitis B virus infection, positive serology for delta virus is uncommon in Sichuan Province, The People's Republic of China. 相似文献
33.
以钒基核苷酸复合物为核酸酶抑制剂,从人胚组织中制备总RNA,所得产品几乎不含DNA和蛋白质,经过分离Poly(A)~ mRNA,证明制品有合成cDNA的完整功能,方法比较简捷,适于大量制备以满足分离mRNA 之需,并讨论了此法的优缺点。 相似文献
34.
35.
X Dong M He X Song B Lu Y Yang S Zhang N Zhao L Zhou Y Li X Zhu R Hu 《Diabetic medicine》2007,24(12):1482-1486
AIMS: Our aim was to assess performances of the Cockcroft-Gault and simplified Modification of Diet in Renal Disease (MDRD) formulae in estimating glomerular filtration rate (GFR) in Chinese diabetic populations and their association with vascular risks. METHODS: A total of 1009 patients with Type 2 diabetes were categorized into low estimated GFR groups (GFR < 60 ml/min/1.73 m(2)) and control groups by the two equations. The performances of these formulae were assessed at different stages of kidney function. Carotid artery intima-media thickness (IMT) and the prevalence of diabetic retinopathy or albuminuria were compared among the groups. The ability of these formulae to identify established vascular risk markers using sensitivity, specificity, positive and negative predictive values were also compared. RESULTS: The prevalence of low estimated GFR was 32.7% with the Cockcroft-Gault formula and 5.2% with the MDRD formula, respectively. In low estimated GFR subjects by the MDRD formula, IMT was significantly thicker than those by the Cockcroft-Gault formula (1.2 mm vs. 1.0 mm; P < 0.05), with a higher prevalence of albuminuria (78.4 vs. 52.8%, P < 0.05) and diabetic retinopathy (46.5 vs. 30.5%; P < 0.05). The Cockcroft-Gault formula gave a specificity of 71.7% and a sensitivity of 37.0%, and the MDRD formula gave a specificity of 96.6% and a sensitivity of 7.9% in estimating low GFR relevant for established vascular risks. CONCLUSIONS: These formulae performed differently in Chinese diabetic populations. The simplified MDRD formula is minimally superior to the Cockcroft-Gault formula for its high specificity and positive predictive values in estimating low GFR relevant for vascular risks. 相似文献
36.
The authors reviewed the radiographic manifestations of 17 cases of parosteal osteosarcoma, with pathologic correlation in 15. There were two types of parosteal osteosarcoma radiologically. The majority of cases were type I with uniformly dense masses which had regular borders. They often adhered to the cortex and showed no evidence of soft-tissue invasion which correlated with low-grade pathologic malignancy and a relatively benign clinical course. Type II involved the bone, soft-tissue and the medullary cavity. These lesions were poorly differentiated and frequently accompanied by metastatic lesions.
相似文献
37.
38.
吴克明教授是成都中医药大学附属医院教授、硕士研究生导师,长期从事临床、科研、教学工作,笔者随师临诊,发现导师治疗卵泡发育障碍性病症经验丰富,临床疗效确切,特择其要介绍如下. 相似文献
39.
V Pesakova P Gillery F X Maquart J P Borel M Adam 《Biomedicine & Pharmacotherapy》1991,45(10):455-459
The effects of some antirheumatics on the formation and retraction of collagen lattices seeded with fibroblasts have been studied. Among the antirheumatics, diclofenac was the most active inhibitor of lattice retraction, then tropesin and to a lesser extent indomethacin. Ibuprofen which is known as a very slight inhibitor of protein synthesis was able to significantly enhance lattice retraction when 10 micrograms/ml (48.5 microM) and 50 micrograms/ml (242 microM) were used. 相似文献
40.