全文获取类型
收费全文 | 60169篇 |
免费 | 3641篇 |
国内免费 | 258篇 |
专业分类
耳鼻咽喉 | 668篇 |
儿科学 | 1830篇 |
妇产科学 | 1359篇 |
基础医学 | 8920篇 |
口腔科学 | 4641篇 |
临床医学 | 5057篇 |
内科学 | 12105篇 |
皮肤病学 | 1356篇 |
神经病学 | 5041篇 |
特种医学 | 1617篇 |
外国民族医学 | 5篇 |
外科学 | 6462篇 |
综合类 | 744篇 |
一般理论 | 28篇 |
预防医学 | 5987篇 |
眼科学 | 964篇 |
药学 | 3988篇 |
4篇 | |
中国医学 | 532篇 |
肿瘤学 | 2760篇 |
出版年
2023年 | 567篇 |
2022年 | 1274篇 |
2021年 | 2177篇 |
2020年 | 1444篇 |
2019年 | 1841篇 |
2018年 | 2197篇 |
2017年 | 1591篇 |
2016年 | 1684篇 |
2015年 | 2035篇 |
2014年 | 2649篇 |
2013年 | 3148篇 |
2012年 | 4636篇 |
2011年 | 4807篇 |
2010年 | 2558篇 |
2009年 | 2124篇 |
2008年 | 3298篇 |
2007年 | 3368篇 |
2006年 | 3000篇 |
2005年 | 2648篇 |
2004年 | 2513篇 |
2003年 | 2220篇 |
2002年 | 1876篇 |
2001年 | 1193篇 |
2000年 | 1195篇 |
1999年 | 1018篇 |
1998年 | 416篇 |
1997年 | 303篇 |
1996年 | 250篇 |
1995年 | 250篇 |
1994年 | 196篇 |
1993年 | 179篇 |
1992年 | 477篇 |
1991年 | 442篇 |
1990年 | 408篇 |
1989年 | 367篇 |
1988年 | 380篇 |
1987年 | 317篇 |
1986年 | 281篇 |
1985年 | 262篇 |
1984年 | 221篇 |
1983年 | 176篇 |
1982年 | 111篇 |
1979年 | 174篇 |
1978年 | 142篇 |
1975年 | 117篇 |
1974年 | 138篇 |
1973年 | 153篇 |
1971年 | 109篇 |
1970年 | 115篇 |
1969年 | 98篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
7.
Glauber T Silva Alejandro C Frery Mostafa Fatemi 《Computerized medical imaging and graphics》2006,30(5):321-327
We study the image formation of vibro-acoustography systems based on a concave sector array transducer taking into account depth-of-field effects. The system point-spread function (PSF) is defined in terms of the acoustic emission of a point-target in response to the dynamic radiation stress of ultrasound. The PSF on the focal plane and the axis of the transducer are presented. To extend the obtained PSF to the 3D-space, we assume it is a separable function in the axial direction and the focal plane of the transducer. In this model, an image is formed through the 3D convolution of the PSF with an object function. Experimental vibro-acoustography images of a breast phantom with lesion-like inclusions were compared with simulated images. Results show that the experimental images are in good agreement with the proposed model. 相似文献
8.
Zinc sulfate addition to glass-ionomer-based cements: influence on physical and antibacterial properties, zinc and fluoride release. 总被引:5,自引:0,他引:5
Prudencio W R Osinaga Rosa Helena M Grande Rafael Y Ballester Maria Regina L Simionato Célia Regina M Delgado Rodrigues Antonio Muench 《Dental materials》2003,19(3):212-217
OBJECTIVES: The aim of this study is to evaluate the effect of ZnSO(4) addition to a conventional glass ionomer and a resin-modified glass ionomer on solubility, flexural strength, zinc and fluoride (F) release, and Streptococcus mutans growth inhibition. METHODS: 5 or 10% ZnSO(4) was added to Vitremer and Ketac-Fil powders. Solubility test was performed based on ISO 7489. Flexural strength was determined by 3-point bending test based on ISO 4049. Zn release/uptake was determined by atomic emission spectrometry; F release/uptake was measured using a F-specific electrode. Both release measurements were performed for 15 d before and 15 d after recharging. Antibacterial test was conducted according to agar plate methods against S. mutans, by measuring the inhibition halos in 1-h and 15-d specimens. Data were analyzed by ANOVA. RESULTS: Solubility increased with higher ZnSO(4) content, but remained below the ISO 7489 limit. Flexural strength was not affected by ZnSO(4) addition, and Vitremer performed better than Ketac-Fil. The control materials released no zinc. Vitremer with 10% ZnSO(4) released the highest amount of zinc. Fluoride release was similar for Ketac-Fil and Vitremer. In both cases, the highest amounts were released in the first 24 h. The growth inhibition halo of S. mutans was similar for both materials with highest content of ZnSO(4) and occurred only with 1-h specimens. SIGNIFICANCE: Zinc addition decreased microorganisms growth and improved fluoride release, without significantly affecting the materials' flexural strength and solubility. 相似文献
9.
Mariana Spitz Alexandre Aluízio Costa Machado Rodrigo do Carmo Carvalho Fernanda Martins Maia Monica Santoro Haddad Dagoberto Calegaro Milberto Scaff Egberto Reis Barbosa 《Movement disorders》2006,21(9):1520-1522
We report on 3 patients with pseudoathetosis, which are involuntary, slow, writhing movements due to loss of proprioception. 相似文献
10.
Sandeep Gohar Devendra Desai Anand Joshi Anita Bhaduri Ramesh Deshpande C Balkrishna Mukesh Chawla Camila Rodrigues V R Joshi 《Indian journal of gastroenterology》2003,22(4):140-142
INTRODUCTION: Autoimmune hepatitis (AIH) is a well-defined entity in the West but there are sparse Indian data on this disease. AIM: To study the clinical profile and response to treatment of Indian patients with AIH. METHODS: This is a part retrospective and part prospective study of 50 patients (median age 48 years, range 11-82; 43 women) seen between 1995 to 2001, diagnosed to have AIH as per the revised scoring system. Clinical and laboratory profile, response to treatment, and complications of treatment were analyzed. RESULTS: AIH accounted for 6% of all patients with liver disease seen during the period. The presenting symptoms were gastrointestinal in 43 and non-gastrointestinal in 7, with median symptom duration of 6 months (range 2 weeks to 40 years). Forty patients (80%) had chronic liver disease. Associated illnesses were present in 28 patients. Twenty-six patients were classified as definite and the rest as probable AIH. Forty-nine patients had Type 1 AIH. Five patients had overlap syndrome. Forty-five patients (90%) received immunosuppressive therapy. Twelve of 18 patients receiving only prednisolone and 21 of 27 patients receiving prednisolone and azathioprine combination responded. Thirteen (26%) patients had therapy-related complications (infectious 5, non infectious 8) with two treatment-related deaths. CONCLUSION: Type 1 AIH was the predominant type of AIH. The majority of patients with AIH presented with chronic liver disease. There was good response to immunosuppressive therapy. Therapy-related complications occurred in one-fourth of patients. 相似文献