全文获取类型
收费全文 | 3921篇 |
免费 | 210篇 |
国内免费 | 27篇 |
专业分类
耳鼻咽喉 | 62篇 |
儿科学 | 129篇 |
妇产科学 | 112篇 |
基础医学 | 326篇 |
口腔科学 | 54篇 |
临床医学 | 368篇 |
内科学 | 1042篇 |
皮肤病学 | 49篇 |
神经病学 | 354篇 |
特种医学 | 126篇 |
外国民族医学 | 3篇 |
外科学 | 680篇 |
综合类 | 87篇 |
一般理论 | 1篇 |
预防医学 | 167篇 |
眼科学 | 103篇 |
药学 | 229篇 |
中国医学 | 9篇 |
肿瘤学 | 257篇 |
出版年
2024年 | 5篇 |
2023年 | 28篇 |
2022年 | 63篇 |
2021年 | 131篇 |
2020年 | 90篇 |
2019年 | 123篇 |
2018年 | 148篇 |
2017年 | 103篇 |
2016年 | 119篇 |
2015年 | 125篇 |
2014年 | 180篇 |
2013年 | 224篇 |
2012年 | 316篇 |
2011年 | 337篇 |
2010年 | 173篇 |
2009年 | 161篇 |
2008年 | 259篇 |
2007年 | 265篇 |
2006年 | 218篇 |
2005年 | 244篇 |
2004年 | 199篇 |
2003年 | 196篇 |
2002年 | 160篇 |
2001年 | 37篇 |
2000年 | 30篇 |
1999年 | 29篇 |
1998年 | 21篇 |
1997年 | 16篇 |
1996年 | 7篇 |
1995年 | 10篇 |
1994年 | 10篇 |
1993年 | 9篇 |
1992年 | 17篇 |
1991年 | 10篇 |
1990年 | 14篇 |
1989年 | 5篇 |
1988年 | 7篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1983年 | 8篇 |
1981年 | 6篇 |
1980年 | 7篇 |
1979年 | 6篇 |
1976年 | 4篇 |
1974年 | 3篇 |
1972年 | 5篇 |
1971年 | 3篇 |
1964年 | 2篇 |
排序方式: 共有4158条查询结果,搜索用时 1 毫秒
1.
2.
3.
Samet Ozlugedik Muge Ozcan Olca Basturk Orgun Deren Erkan Kaptanoglu G?khan Adanali Adnan Unal 《Skull base》2005,15(4):269-72; discussion 273
Ameloblastic carcinoma (AC) is an aggressive malignant epithelial odontogenic tumor. It may appear de novo or originate from a pre-existing ameloblastoma or odontogenic cyst. To our knowledge, an AC that originates from the anterior skull base has not been reported before in the English literature. We report a case of an AC that originated from the anterior skull base and invaded the dura of the anterior fossa and discuss its clinical course and treatment. 相似文献
4.
5.
Comparison of Asymmetry in Cerebral Blood Flow Between Brain Hemispheres Using Digital Subtraction Angiography 总被引:2,自引:0,他引:2
Afshin A. Divani PhD Adnan I. Qureshi MD Kenneth R. Hoffman PhD M. Fareed K. Suri MD Jawad F. Kirmani MD 《Journal of neuroimaging》2006,16(2):139-145
BACKGROUND AND PURPOSE: Recently, endovascular techniques have gained significant therapeutic potential for both treatment and prevention of stroke. Cerebral angiography, which is an essential component of these procedures, has been used to provide morphological information regarding condition of blood vessels. In this study, we propose to determine the possibility of acquiring information regarding cerebral blood flow (CBF) in addition to morphologic information from data routinely available during angiography. METHODS: Digital subtraction angiography sequences were obtained for eight patients having occlusive disease in internal carotid artery (ICA) territories. Two regions-of-interest (ROIs) corresponding to the two brain hemispheres on AP view were delineated. For each image, the average pixel value within each ROI was calculated and used to generate time-density curves. Indices obtained from each curve were compared with each other and with the results obtained from the single photon emission computed tomography (SPECT) studies performed a pre- or postangiography procedure. RESULTS: Comparison between ICA stenosis and cerebral perfusion measurements revealed that cerebral perfusion deficit can be independent of arterial occlusive disease. The indices obtained from the time-density curves exhibit a correlating trend with the results from SPECT studies. However, lack of sufficient sample data prevented any meaningful statistical analysis to be conducted. CONCLUSIONS: We have developed a technique for utilizing the angiographic data for the important task of routinely and easily measuring CBF. Availability of CBF measurements during cerebral angiography may favorably impact upon the appropriate use of endovascular procedures and potentially contribute to the reduction of morbidity and mortality associated with stroke. 相似文献
6.
Nazli Janjua MD Navin Verma MD Ammar Alkawi MD Jawad F. Kirmani MD Adnan I. Qureshi MD 《Journal of neuroimaging》2006,16(3):212-215
Endovascular stent-supported angioplasty is a treatment option for atherosclerotic disease of the cervical internal carotid artery in high-risk patients. The traditional transfemoral approach is not suitable for patients who suffer from common femoral artery or abdominal aorta atheropathy. We report a case of carotid stent deployment using the radial route in a 68-year-old man with type B aortic dissection, having severe right internal carotid artery origin stenosis, presenting with ipsilateral retinal ischemic events. Technical aspects of carotid stenting via the radial approach are described and the related literature is discussed. 相似文献
7.
8.
An expedient, rapid, and sensitive capillary gas chromatographic method for the analysis of l,3-bis(2-chloroethyl)-l-nitrosourea (BCNU) or l-(2-chloroethyl)-3-cyclohexyl-l-nitrosourea (CCNU) in plasma is described. Separation of the underivatized nitrosourea compounds was performed on a 0.33-mm-i.d., 25-m fused-silica, SE-30 capillary column, and detection was carried out using a thermionic N–P-specific detector. The compounds were extracted from plasma with benzene with a yield of >87%. The assay was linear in the ranges of 0.001 to 0.5 and 0.5 to 25 µg/ml for CCNU or 0.003 to 0.50 and 0.5 to 25 µg/ml for BCNU, with correlation coefficients from 0.9914 to 0.9999 and coefficients of variation (CV) of <3.3%. Other antineoplastic agents did not interfere in the assay. The method was employed to study the pharmacokinetics of BCNU in rabbits. The plasma concentration-time curves were fit to a two-compartment model with a mean (SE) , , and total-body clearance of 2.898 (0.913) hr–1, 0.1228 (0.0179) hr–1, and 7.211 (2.862) liters/hr · kg, respectively. Further, the stability of BCNU and CCNU in solution was examined at different temperatures. Both compounds were stable in benzene or acetone (4 to 37°C) but labile in plasma even if refrigerated. The apparent rate constants for degradation of BCNU and CCNU were 0.09921 and 0.02853 hr–1 at 4°C and 5.998 and 2.553 hr–1 at 37°C, respectively. 相似文献
9.
The immune response after streptococcal infections of the skin and of the joints was studied in an experimental animal model. Hamsters were challenged intradermally or intra-articularly with different streptococcal serotypes, and antibodies for streptolysin O (ASO), deoxyribonuclease B (anti-deoxyribonuclease B), and group A carbohydrate (anti-group A CHO) were determined. After a single injection at either site, 7 of 48 animals (14%) developed group A-CHO antibodies; however, none of the animals developed detectable levels of ASO or anti-deoxyribonuclease B. After repeated infections of the skin or joint, anti-deoxyribonuclease B antibodies were detectable in 13% (4 of 30) and 30% (5 of 17) of the animals, respectively. Elevations of ASO occurred after repeated joint infections in 4 of 16 animals (25%), whereas none of 30 hamsters repeatedly infected intradermally developed antibodies against streptolysin O. For all three antibodies tested, elevated levels were more frequently noted after repeated joint infections than after repeated skin infections with the same streptococcal serotype. These data, similar to ones previously noted in human impetigo, indicate that ASO responses are feeble after streptococcal skin infections and that the site of infection per se, rather than the infecting strain, appears to be responsible for this poor response. 相似文献
10.