全文获取类型
收费全文 | 108249篇 |
免费 | 4346篇 |
国内免费 | 275篇 |
专业分类
耳鼻咽喉 | 1567篇 |
儿科学 | 3174篇 |
妇产科学 | 2647篇 |
基础医学 | 14670篇 |
口腔科学 | 3577篇 |
临床医学 | 6639篇 |
内科学 | 24826篇 |
皮肤病学 | 2992篇 |
神经病学 | 8698篇 |
特种医学 | 2318篇 |
外国民族医学 | 6篇 |
外科学 | 13580篇 |
综合类 | 501篇 |
一般理论 | 29篇 |
预防医学 | 12029篇 |
眼科学 | 2452篇 |
药学 | 8020篇 |
中国医学 | 370篇 |
肿瘤学 | 4775篇 |
出版年
2023年 | 644篇 |
2022年 | 561篇 |
2021年 | 1994篇 |
2020年 | 1061篇 |
2019年 | 2181篇 |
2018年 | 3643篇 |
2017年 | 2159篇 |
2016年 | 2105篇 |
2015年 | 2496篇 |
2014年 | 2710篇 |
2013年 | 4239篇 |
2012年 | 7093篇 |
2011年 | 7352篇 |
2010年 | 3755篇 |
2009年 | 2746篇 |
2008年 | 5995篇 |
2007年 | 6256篇 |
2006年 | 6048篇 |
2005年 | 6032篇 |
2004年 | 5524篇 |
2003年 | 5130篇 |
2002年 | 4842篇 |
2001年 | 3257篇 |
2000年 | 3467篇 |
1999年 | 2741篇 |
1998年 | 545篇 |
1997年 | 326篇 |
1996年 | 355篇 |
1992年 | 1303篇 |
1991年 | 1189篇 |
1990年 | 1123篇 |
1989年 | 1008篇 |
1988年 | 904篇 |
1987年 | 908篇 |
1986年 | 851篇 |
1985年 | 824篇 |
1984年 | 609篇 |
1983年 | 482篇 |
1979年 | 623篇 |
1978年 | 362篇 |
1976年 | 328篇 |
1975年 | 367篇 |
1974年 | 543篇 |
1973年 | 511篇 |
1972年 | 460篇 |
1971年 | 402篇 |
1970年 | 481篇 |
1969年 | 438篇 |
1968年 | 422篇 |
1967年 | 383篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
Henyse G V Silva Rosangela P Tórtora Maria Lucia F Farias 《Gynecological endocrinology》2005,21(3):174-179
To evaluate the impact of pregnancy on bone, we studied bone turnover at the first (T1) and third (T3) trimester of gestation in 58 adolescents and 28 healthy adolescents who had never been pregnant. Total body (TB) and lumbar spine (LS) bone mineral density (BMD) and body composition were evaluated by dual-energy X-ray absorptiometry in all control patients (C) and after parturition in 28 pregnant patients (G). Paired and unpaired t tests, Mann-Whitney and Pearson correlation tests were used. Bone turnover markers were above the reference range for adult women in more than 80% of the adolescents, with no difference between C and G patients at T1. Increase in urinary N-telopeptide crosslinks of type I collagen and serum bone-specific alkaline phosphatase, markers of bone turnover, was seen during pregnancy ( p < 0.0001). Body composition did not differ between groups, but LS BMD, percentage of expected LS BMD, LS Z-score, percentage of expected TB BMD and TB Z-score were lower in G than C patients ( p < 0.05). TB BMD was positively correlated with LS BMD (r2 = 0.52). The inverse correlations between bone markers and LS BMD suggest that the increased bone turnover during pregnancy probably explains the low bone density after parturition. The impact on future peak bone mass must be studied. 相似文献
32.
33.
J Vargas-Barrón A Andrade-Freire J C Ramírez E Waisser J Martínez-Sánchez 《Archivos del Instituto de Cardiología de México》1989,59(2):121-124
The purpose of this study is to determine the importance of two-dimensional echocardiography performed soon after admission to the coronary care unit to provide useful information concerning wall-motion abnormalities, and to detect and characterize left ventricular thrombi. A major goal is to identify a subgroup of patients with acute myocardial infarction who are at risk for systemic embolization; in this subgroup the benefits of anticoagulation treatment would theoretically outweigh the associated risks. We studied 7 consecutive male patients, age range from 32 to 60 years, with acute myocardial infarction. Five patients had antero-septal infarction, 1 anterolateral and another had anterior wall infarction. We performed two-dimensional echocardiography within the first week after admission. All patients had severe apical-wall-motion abnormalities (akinesis or dyskinesis) and left ventricular thrombi. All patients received anticoagulation therapy. Two-dimensional echocardiography, performed one month after the first study, showed that the thrombi had decreased in size in 6 patients and could not be visualized in 1 patient. The noninvasive nature of echocardiography allows serial evaluations of patients with known left ventricular thrombi and permits assessment of the effect of therapy. 相似文献
34.
35.
G López Casasnovas 《Gaceta sanitaria / S.E.S.P.A.S》1989,3(15):573-580
The following pages try to offer some ways of arguing against pesimism in our health administration culture. In fact, the review of a wide range of feasible reforms of our health system undertaken in this paper gives some clues for a better implementation of the a priori advantages of public health systems. These advantages are not achieved today because of some dysfunctionalities of daily management. To rationalize resources distribution, to evaluate the results, to eliminate unnecessary administrative control, to coordinate responsibility and budgeting centers, to introduce free choice as a response to public demand, and to simulate marketing by private production of public services are elements suggested in this paper to improve public health services management. 相似文献
36.
37.
M Gómez-Silva L Garza-Oca?as N Waksman V Rivas A Pi?eyro-López 《Toxicology in vitro》2005,19(1):47-53
T-514 (Peroxisomicine A(1)) from Karwinskia humboldtiana is a dimeric hydroxyanthracenone with a highly selective cytotoxic effect on tumor cells. We evaluated the metabolism of this compound in two in vitro systems (liver microsomes and hepatocytes) and assessed the cytotoxicity of its metabolites on normal and tumor cells. Microsomes (12.5, 125 and 250 microg of protein/ml) and hepatocytes (1 x 10(6) cells/ml) were incubated with the toxin (25 microM) for 0.5, 1, 3, 6, 9, 12 and 24 h and the samples were examined using chromatographic analysis and UV spectra. Two metabolites (M1 and M2) were detected in the rat microsomes and one (M1) in the monkey microsomes. The retention times and UV spectra of the peaks were very similar to those of the toxin T-514. M1 was isolated and identified as a mixture of two isomers. The cytotoxicity of the metabolites was evaluated in Chang liver and Hep G2 cells but they did not show the selective cytotoxic effect on tumor cells seen in the original compound. 相似文献
38.
39.
Antonio Gómez Mercedes Salgado Manuel Valladares-Ayerbes Mónica Jorge Ana Carballo Sonia Candamio Pilar Izquierdo Paula Peleteiro Rafael López 《Clinical & translational oncology》2010,12(12):843-848
Objective
The aim of the project was to assess the effectiveness and safety of weekly epoetin-beta (EB) in patients with gastrointestinal cancer (GIC) subjected to concomitant chemoradiotherapy (CCTRT). 相似文献40.
Carlos Ferrer Albiach Antonio Conde Moreno Marta Rodríguez Cordón Virginia Morillo Macías Ana Bouché Babiloni Inmaculada Beato Tortajada Ángel Sánchez Iglesias Alicia Francés Muñoz 《Clinical & translational oncology》2010,12(1):22-26
Hypoxia is related to poor prognosis because it is associated to chemo-and radioresistance. During recent years the evolution
of imaging methods like PET/CT and MRI has meant the appearance of new perspectives with direct implications in radiation
therapy. We discuss previous experiences in staging, planning and in the follow-up process with these techniques for measuring
tumour hypoxia. 相似文献