全文获取类型
收费全文 | 236796篇 |
免费 | 20054篇 |
国内免费 | 5198篇 |
专业分类
耳鼻咽喉 | 3966篇 |
儿科学 | 4363篇 |
妇产科学 | 3853篇 |
基础医学 | 18711篇 |
口腔科学 | 8369篇 |
临床医学 | 21374篇 |
内科学 | 21997篇 |
皮肤病学 | 2463篇 |
神经病学 | 13558篇 |
特种医学 | 6709篇 |
外国民族医学 | 12篇 |
外科学 | 26736篇 |
综合类 | 36826篇 |
现状与发展 | 10篇 |
一般理论 | 24篇 |
预防医学 | 29488篇 |
眼科学 | 4872篇 |
药学 | 21597篇 |
363篇 | |
中国医学 | 26608篇 |
肿瘤学 | 10149篇 |
出版年
2024年 | 1057篇 |
2023年 | 4703篇 |
2022年 | 8886篇 |
2021年 | 11626篇 |
2020年 | 11320篇 |
2019年 | 12517篇 |
2018年 | 11078篇 |
2017年 | 9734篇 |
2016年 | 8740篇 |
2015年 | 8204篇 |
2014年 | 16025篇 |
2013年 | 16321篇 |
2012年 | 14187篇 |
2011年 | 15184篇 |
2010年 | 12289篇 |
2009年 | 10833篇 |
2008年 | 10027篇 |
2007年 | 10123篇 |
2006年 | 8611篇 |
2005年 | 7310篇 |
2004年 | 6016篇 |
2003年 | 5299篇 |
2002年 | 4140篇 |
2001年 | 3439篇 |
2000年 | 2995篇 |
1999年 | 2499篇 |
1998年 | 2042篇 |
1997年 | 1814篇 |
1996年 | 1493篇 |
1995年 | 1395篇 |
1994年 | 1256篇 |
1993年 | 1106篇 |
1992年 | 1010篇 |
1991年 | 932篇 |
1990年 | 802篇 |
1989年 | 773篇 |
1988年 | 715篇 |
1987年 | 632篇 |
1986年 | 608篇 |
1985年 | 1898篇 |
1984年 | 2199篇 |
1983年 | 1409篇 |
1982年 | 1818篇 |
1981年 | 1283篇 |
1980年 | 1074篇 |
1979年 | 960篇 |
1978年 | 785篇 |
1977年 | 570篇 |
1976年 | 708篇 |
1975年 | 485篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Systolic and diastolic blood pressures were measured on 254 monozygotic (MZ) and 260 dizygotic (DZ) male twin pairs, during middle age (average age 48 years) and at two later age points. Genetic and environmental components of covariation were modeled by time series. For both measures, shared environmental influences were absent and specific environmental influences were largely time-specific. Although heritability was about 0.5 at each time point, genetic variation present at middle age contributed only about 60% to that present 9 years later, the remaining 40% being new. Fifteen years later, at the third time point, no new genetic variation was evident, variation in individual differences being entirely attributable to genetic differences laid down at the two earlier ages. © 1993 Wiley-Liss, Inc. 相似文献
92.
本文报告了1990年5月以来脑干区大型、复杂占位病变15例.其中,位于脑干内3例,脚间窝2例,岩尖部4例,全岩骨区1例,全斜坡区2例,第四脑室内3例.本组采用以扩大了的岩骨入路为主的联合入路,行肿瘤全切除8例,次全切除5例.2例仅作了活检加减压术.除1例死亡外,均恢复良好.本文结合文献,对脑干区手术入路进行了讨论. 相似文献
93.
94.
J. C. Mathers 《Journal of human nutrition and dietetics》1988,1(3):155-161
Eleven healthy free-living adults (six women, five men) weighed and recorded all food and drink consumed and collected all urine for two non-consecutive 7-day periods whilst eating their usual diet (Period 1) and attempting to reduce salt intake (Period 2). Bread (including pitta bread) provided on average a quarter of total Na intake of subjects in Period 1 so that wholemeal bread made without added salt was made available in Period 2. All subjects achieved substantial reductions (mean 65%) in Na intake in Period 2 with no change in K intake so that the Na:K molar ratio fell from 1.3 to 0.5. Urinary Na output closely followed intakes and there was a large increase (mean 11.2 μg/d) in aldosterone excretion with a non-significant increase in K output. Simple linear relationships which allow prediction of Na and K intake from the more easily measured urinary output were derived. 相似文献
95.
S. Takahashi K. Ishii K. Matsumoto S. Higano T. Ishibashi M. Suzuki K. Sakamoto 《Neuroradiology》1994,36(5):337-339
We reviewed 12 cases of infarcts in the territory of the anterior choroidal artery (AChA) on CT and/or MRI. In each case vascular occlusion in the region was verified angiographically. Although the extent of the lesion on CT/MR images was variable, all were located on the axial images within an arcuate zone between the striatium anterolaterally and the thalamus posteromedially. The distribution of the lesions on mutiplanar MRI conformed well to the territory of the AChA demonstrated microangiographically. The variability of the extent of the infarcts may be explained by variations in the degree of occlusive changes in the AChA or the development of collateral circulation through anastomoses between the AChA and the posterior communicating and posterior cerebral arteries. The extent of the lesion appeared to be closely related to the degree of neurological deficit. 相似文献
96.
Mentosternal contractures still represent a surgical challenge due to their prominent position. They require early operative treatment for both function and aesthetic reasons. Careful clinical examination of scar position and traction forces, both at rest and when functioning, in addition to proper evaluation of the surrounding soft tissue are mandatory for precise preoperative planning of the required reconstruction. In general, the technically most feasible operation is favored if the functional and aesthetic results are good and postoperative risk for recurrence is low. Between 1987 and 1994, 21 patients with cervical, mentosternal, and mentothoracic contractures were operated upon. Eight patients were reconstructed with local flaps and 13 with microvascular free flaps. 相似文献
97.
98.
Background: Laparoscopic stapling was found to be a viable option for attaching epimysial electrodes onto the abdominal surface of the
diaphragm. Stapling was preferable to suturing due to its simplicity and speed.
Methods: Of the two staplers tested in this study, the Ethicon Endopath was preferred over the Autosuture Endo Hernia because the
staples did not penetrate the diaphragm when an electrode tab thickness greater than 0.75 mm was used.
Results: The thickness of the electrode tab was an important factor in determining staple penetration but large variation in penetration
depth indicated that other factors may also play a role. An electrode tab thickness of 1.0–1.25 mm was suggested to minimize
the risk of diaphragm perforation.
Conclusions: The histological reaction to staples implanted up to 14 months was unremarkable, reflecting the safety of laparoscopic staples
for permanently anchoring electrodes on the diaphragm.
Received: 2 April 1996/Accepted: 12 June 1996 相似文献
99.
I. V. Smirnov A. A. Khachatur'yan 《Bulletin of experimental biology and medicine》1991,112(5):1601-1603
All-Union Hematology Research Center, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. I. Vorob'ev.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 112, No. 11, pp. 500–501, November, 1991. 相似文献
100.