全文获取类型
收费全文 | 4851篇 |
免费 | 356篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 21篇 |
儿科学 | 168篇 |
妇产科学 | 137篇 |
基础医学 | 746篇 |
口腔科学 | 41篇 |
临床医学 | 627篇 |
内科学 | 990篇 |
皮肤病学 | 101篇 |
神经病学 | 503篇 |
特种医学 | 120篇 |
外科学 | 437篇 |
综合类 | 22篇 |
一般理论 | 3篇 |
预防医学 | 548篇 |
眼科学 | 123篇 |
药学 | 287篇 |
1篇 | |
中国医学 | 2篇 |
肿瘤学 | 351篇 |
出版年
2024年 | 9篇 |
2023年 | 62篇 |
2022年 | 102篇 |
2021年 | 222篇 |
2020年 | 121篇 |
2019年 | 163篇 |
2018年 | 203篇 |
2017年 | 155篇 |
2016年 | 131篇 |
2015年 | 195篇 |
2014年 | 252篇 |
2013年 | 299篇 |
2012年 | 361篇 |
2011年 | 397篇 |
2010年 | 217篇 |
2009年 | 156篇 |
2008年 | 298篇 |
2007年 | 280篇 |
2006年 | 286篇 |
2005年 | 242篇 |
2004年 | 232篇 |
2003年 | 185篇 |
2002年 | 154篇 |
2001年 | 43篇 |
2000年 | 24篇 |
1999年 | 26篇 |
1998年 | 34篇 |
1997年 | 25篇 |
1996年 | 29篇 |
1995年 | 21篇 |
1994年 | 28篇 |
1993年 | 25篇 |
1992年 | 17篇 |
1991年 | 15篇 |
1990年 | 12篇 |
1989年 | 15篇 |
1988年 | 13篇 |
1987年 | 9篇 |
1986年 | 11篇 |
1985年 | 11篇 |
1984年 | 10篇 |
1983年 | 10篇 |
1982年 | 8篇 |
1980年 | 12篇 |
1975年 | 6篇 |
1974年 | 12篇 |
1973年 | 6篇 |
1971年 | 7篇 |
1970年 | 8篇 |
1969年 | 7篇 |
排序方式: 共有5228条查询结果,搜索用时 15 毫秒
31.
We aimed to develop a novel and effective technique for creating a smooth deep lamellar dissection of the cornea using a femtosecond (FS) laser for deep anterior lamellar keratoplasty (DALK), we conducted a retrospective eye bank study. Thirteen fresh human corneas were mounted on an artificial anterior chamber, and deep lamellar cuts were made with a 500-kHz VisuMax FS laser at a level of 50–80 mm anterior to the Descemet’s membrane (DM). A posterior diameter of 8 mm with a side cut angle of 110° was used for the anterior penetrating side cut. The anterior lamellar tissue was bluntly dissected. The residual posterior stromal beds and side cuts were examined with microscopy and intraoperative optical coherence tomography (OCT) and post-cut endothelial cell evaluations. All corneas revealed a smooth residual posterior stromal bed without any visible irregularities or ridges by microscopy and OCT imaging. Six corneas were suitable for post-cut endothelial cell evaluation 2 days after laser cut, with no significant endothelial cell loss post-laser and blunt dissection of the posterior stroma. FS laser deep lamellar keratoplasty utilizing an ultrafast laser to produce a smooth deep stromal dissection followed by blunt dissection and removal of the anterior stromal tissue yields a consistent and smooth residual stromal bed. The creation of a smooth lamellar dissection in the deep posterior cornea may result in more consistent DALK without the need for air bubble or manual baring of DM that has the risk for DM perforation. 相似文献
32.
33.
Constituents of beri-beri-producing diets, borderline diets, and protective diets given by Braddon and others were analysed for vitamin B1 content by Cowgill. He used a long series of assays published by numerous investigators and calculated the various units and percentage values as milligram equivalents of a yeast powder. He thus obtained approximate vitamin B1 values for these diets. He showed that these values, together with the incidence of beri-beri, justified the application to man of a formula obtained experimentally and gave an indication of man''s minimum requirement of the vitamin.In this paper the vitamin B1 value of the same diets has been obtained from direct assays against the International Standard of the constituent foods, raw or cooked, as usually eaten. These are in good agreement with the values drawn from the less direct calculation, and indicate that man''s minimum requirement may vary according to weight and food intake between 200 and 500 units daily.The desirable level of B1 intake for adults and children has been studied by analysing in the same way a series of diets recommended by public bodies or by dietitians in England and America. Adults on good diets consume 450 to 750 units daily. High vitamin diets may contain about 1,500 units.Diets recommended for children show relatively higher levels than those for adults, that of a child aged 4 years having nearly 400 units and that of a child aged 11 years having about 650. 相似文献
34.
35.
36.
37.
Audrey Laurence Dnahin H. Toffa Ke Peng Manon Robert Alain Bouthillier Dang K. Nguyen Frederic Leblond 《Biomedical optics express》2022,13(12):6245
Interictal epileptiform discharges (IEDs) are brief neuronal discharges occurring between seizures in patients with epilepsy. The characterization of the hemodynamic response function (HRF) specific to IEDs could increase the accuracy of other functional imaging techniques to localize epileptiform activity, including functional near-infrared spectroscopy and functional magnetic resonance imaging. This study evaluated the possibility of using an intraoperative multispectral imaging system combined with electrocorticography (ECoG) to measure the average HRF associated with IEDs in eight patients. Inter-patient variability of the HRF is illustrated in terms of oxygenated hemoglobin peak latency, oxygenated hemoglobin increase/decrease following IEDs, and signal-to-noise ratio. A sub-region was identified using an unsupervised clustering algorithm in three patients that corresponded to the most active area identified by ECoG. 相似文献
38.
39.
40.
Emilie Brard Christoph Rllig Sarah Bertoli Arnaud Pigneux Suzanne Tavitian Michael Kramer Hubert Serve Martin Bornhuser Uwe Platzbecker Carsten Müller-Tidow Claudia D. Baldus David Martínez-Cuadrn Josefina Serrano Pilar Martínez-Snchez Eduardo Rodríguez Arbolí Cristina Gil Juan Bergua Teresa Bernal Adolfo de la Fuente Burguera Eric Delabesse Audrey Bidet Pierre-Yves Dumas Pau Montesinos Christian Rcher 《Blood cancer journal》2022,12(7)
In a context of therapeutic revolution in older adults with AML, it is becoming increasingly important to select patients for the various treatment options by taking account of short-term efficacy and toxicity as well as long-term survival. Here, the data from three European registries for 1,199 AML patients aged 70 years or older treated with intensive chemotherapy were used to develop a prognostic scoring system. The median follow-up was 50.8 months. In the training set of 636 patients, age, performance status, secondary AML, leukocytosis, and cytogenetics, as well as NPM1 mutations (without FLT3-ITD), were all significantly associated with overall survival, albeit not to the same degree. These factors were used to develop a score that predicts long-term overall survival. Three risk-groups were identified: a lower, intermediate and higher-risk score with predicted 5-year overall survival (OS) probabilities of ≥12% (n = 283, 51%; median OS = 18 months), 3–12% (n = 226, 41%; median OS = 9 months) and <3% (n = 47, 8%; median OS = 3 months), respectively. This scoring system was also significantly associated with complete remission, early death and relapse-free survival; performed similarly in the external validation cohort (n = 563) and showed a lower false-positive rate than previously published scores. The European Scoring System ≥70, easy for routine calculation, predicts long-term survival in older AML patients considered for intensive chemotherapy.Subject terms: Acute myeloid leukaemia, Risk factors 相似文献