全文获取类型
收费全文 | 1009篇 |
免费 | 72篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 81篇 |
妇产科学 | 8篇 |
基础医学 | 86篇 |
口腔科学 | 29篇 |
临床医学 | 70篇 |
内科学 | 177篇 |
皮肤病学 | 27篇 |
神经病学 | 20篇 |
特种医学 | 132篇 |
外科学 | 111篇 |
综合类 | 134篇 |
预防医学 | 62篇 |
眼科学 | 4篇 |
药学 | 53篇 |
中国医学 | 39篇 |
肿瘤学 | 62篇 |
出版年
2023年 | 7篇 |
2022年 | 14篇 |
2021年 | 23篇 |
2020年 | 18篇 |
2019年 | 13篇 |
2018年 | 19篇 |
2017年 | 14篇 |
2016年 | 19篇 |
2015年 | 27篇 |
2014年 | 41篇 |
2013年 | 37篇 |
2012年 | 44篇 |
2011年 | 44篇 |
2010年 | 71篇 |
2009年 | 60篇 |
2008年 | 24篇 |
2007年 | 27篇 |
2006年 | 39篇 |
2005年 | 27篇 |
2004年 | 15篇 |
2003年 | 24篇 |
2002年 | 12篇 |
2001年 | 13篇 |
2000年 | 10篇 |
1999年 | 18篇 |
1998年 | 45篇 |
1997年 | 59篇 |
1996年 | 51篇 |
1995年 | 38篇 |
1994年 | 32篇 |
1993年 | 31篇 |
1992年 | 9篇 |
1991年 | 6篇 |
1990年 | 10篇 |
1989年 | 23篇 |
1988年 | 19篇 |
1987年 | 17篇 |
1986年 | 16篇 |
1985年 | 10篇 |
1984年 | 10篇 |
1983年 | 2篇 |
1982年 | 9篇 |
1981年 | 8篇 |
1980年 | 11篇 |
1979年 | 3篇 |
1977年 | 6篇 |
1976年 | 6篇 |
1975年 | 2篇 |
1958年 | 4篇 |
1957年 | 2篇 |
排序方式: 共有1098条查询结果,搜索用时 328 毫秒
141.
142.
143.
144.
Sclerosing cholangitis: CT findings 总被引:5,自引:0,他引:5
The value of computed tomography (CT) in the detection of primary sclerosing cholangitis (PSC) in the intrahepatic and extrahepatic biliary systems was assessed by comparing CT scans of 20 cases of PSC with cholangiographic findings. In 16 of 19 cases of extrahepatic duct disease demonstrated with cholangiography, CT demonstrated abnormalities of the common hepatic duct, or bile duct, including duct stenosis, mural nodularity, duct dilatation, wall thickening, and mural enhancement. CT demonstrated intrahepatic disease in all 20 cases, including duct dilatation, duct stenosis, pruning, and beading. CT was superior to cholangiography in characterization of the status of the intrahepatic duct system in 11 of 20 cases. In addition, CT demonstrated extrabiliary complications of PSC in 12 cases and superimposed cholangiocarcinoma in three cases. While cholangiography remains the standard for diagnosis and follow-up of PSC, CT can provide valuable information about the extent and complications of the disease. 相似文献
145.
SÁNDOR HUSZ M.D. Ph .D I. TÓTH-KÁSA M.D. Ph .D M. KISS Ph .D. A. DOBOZY M.D. D.SC Ph .D 《International journal of dermatology》1994,33(3):210-213
Background. The etiology of cold contact urticaria is unknown and the therapy is therefore usually rather disappointing. Methods. This study reports therapeutic data on 42 patients with cold urticaria treated with a combination of terbutaline (3 × 5 mg a week, later 3 × 2.5 mg) and aminophylline-containing drugs (3 × 150 mg). Results. Complete remission of the urticarial response was achieved in 37 of the 42 patients. Conclusions. The therapy was tolerated relatively well and the results are promising. 相似文献
146.
147.
A survey was undertaken to examine the impact of Medicare's Prospective Payment System (PPS) and other recent changes in the health care environment on providers' decisions regarding acquisition of high-cost technologic equipment. The survey group included 199 hospitals and freestanding imaging centers known to have acquired magnetic resonance (MR) imaging units, as well as a random sample of 400 hospitals whose acquisition decisions were unknown to the authors. Fifty-eight percent of the known adopters and 61% of the randomly selected hospitals responded to the survey. Nonadopters' decisions were dominated by economic considerations, including the high cost of MR imagers and concerns about Medicare's reimbursement policies. Competition and a desire to provide the highest quality of care are counterbalancing the retardant effects of PPS, however, and are stimulating widespread diffusion of MR imagers. 相似文献
148.
Synthesized and directly acquired spin-echo images were compared in order to assess the validity of magnetic resonance (MR) image synthesis as a method enabling retrospective formation of images by interactive manipulation of scan parameters. Synthetic images subjectively compared favorably in both accuracy and precision with acquired images when formed for the same values of echo (TE) and repetition times (TR) and for interpolated and extrapolated values of both TE and TR. Plots of synthetic and acquired signals within the same pixel sectors quantitatively showed comparable values for several regions of interest in the brain. Percent error and noise-normalized differences between acquired and synthetic images were tested as a quantitative measure of accuracy. Percent error was consistently less than 5% for brain parenchyma, and synthetic signals were accurate to within four times the noise level at acquisition. The apparent signal-to-noise ratio of synthetic images was comparable, superior, or inferior to similar acquired images, depending on the values of TE and TR. Total acquisition time required for synthetic formation of images for arbitrary values of TE and TR was equivalent to that of a single direct acquisition with a TR of 2,500 msec. 相似文献
149.
SA Koehler 《Acta paediatrica (Oslo, Norway : 1992)》1996,85(12):1514-1519