全文获取类型
收费全文 | 498370篇 |
免费 | 25506篇 |
国内免费 | 2884篇 |
专业分类
耳鼻咽喉 | 6086篇 |
儿科学 | 11968篇 |
妇产科学 | 11902篇 |
基础医学 | 67948篇 |
口腔科学 | 12872篇 |
临床医学 | 37618篇 |
内科学 | 102817篇 |
皮肤病学 | 9334篇 |
神经病学 | 39076篇 |
特种医学 | 19357篇 |
外国民族医学 | 82篇 |
外科学 | 80826篇 |
综合类 | 10922篇 |
现状与发展 | 1篇 |
一般理论 | 64篇 |
预防医学 | 27031篇 |
眼科学 | 10748篇 |
药学 | 37839篇 |
1篇 | |
中国医学 | 2241篇 |
肿瘤学 | 38027篇 |
出版年
2021年 | 2965篇 |
2019年 | 3027篇 |
2018年 | 16584篇 |
2017年 | 13277篇 |
2016年 | 15252篇 |
2015年 | 4761篇 |
2014年 | 6483篇 |
2013年 | 8211篇 |
2012年 | 14059篇 |
2011年 | 21647篇 |
2010年 | 14971篇 |
2009年 | 12498篇 |
2008年 | 21235篇 |
2007年 | 24695篇 |
2006年 | 11277篇 |
2005年 | 12313篇 |
2004年 | 12252篇 |
2003年 | 13269篇 |
2002年 | 11697篇 |
2001年 | 28984篇 |
2000年 | 29781篇 |
1999年 | 24280篇 |
1998年 | 5595篇 |
1997年 | 4713篇 |
1996年 | 4176篇 |
1995年 | 3782篇 |
1994年 | 3420篇 |
1993年 | 3102篇 |
1992年 | 16548篇 |
1991年 | 15284篇 |
1990年 | 14609篇 |
1989年 | 14373篇 |
1988年 | 12952篇 |
1987年 | 12456篇 |
1986年 | 11452篇 |
1985年 | 10654篇 |
1984年 | 7145篇 |
1983年 | 5811篇 |
1982年 | 2874篇 |
1979年 | 5742篇 |
1978年 | 3509篇 |
1977年 | 3076篇 |
1976年 | 2374篇 |
1975年 | 2717篇 |
1974年 | 3165篇 |
1973年 | 2937篇 |
1972年 | 2903篇 |
1971年 | 2845篇 |
1970年 | 2603篇 |
1969年 | 2651篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
N. V. Bashmakova G. N. Chistiakova I. A. Gazieva Y. M. Trapeznikova D. O. Mazurov 《Gynecological endocrinology》2015,31(10):31-33
AbstractThis study was undertaken to compare the concentrations of pro- and anti-angiogenic growth factors, nitric oxide (NO) stable metabolites in maternal serum and embryonic left ventricular (LV) isovolumic relaxation time (IRT, ms) during the first trimester in two groups of women: with pregnancy conceived by assisted reproductive technologies (ART, n?=?39) and normally conceived (control group, n?=?68) pregnancy. The concentration of vasoconstrictor endothelin 1 was 45.5 times more in ART than in control group. On the contrary, the concentrations of NO stable metabolites in ART were 1.9 times less than in control women. The assessment of angiogenic suppressors in ART women demonstrates the decrease in s-endoglin concentration was 1.6 times and in soluble receptor to vascular endothelial growth factor concentration was 2.0 times in comparison with control group. There was a significant increase in LV IRT in ART embryos in comparison to control ones. These data suggest significant changes in pro- anti-angiogenic factors balance and increase in vascular impedance in ART-conceived embryos. 相似文献
2.
Irmak Karaca Suzan Güven Yılmaz Melis Palamar Halil Ateş 《Ocular immunology and inflammation》2020,28(6):947-951
ABSTRACT
Purpose
To investigate the effect of 1% tropicamide on anterior chamber aqueous flare (ACAF) measurements acquired with laser flare meter in patients with pseudoexfoliation. 相似文献3.
Amy Y. Zhang Christopher Burant Alex Z. Fu Gerald Strauss Donald R. Bodner Lee Ponsky 《Journal of psychosocial oncology》2020,38(2):210-227
AbstractPurpose: We examined underlying psychosocial processes of a behavioral treatment for urinary incontinence (UI) of prostate cancer survivors.Design: Secondary analysis of data collected from a clinical trial.Sample: Two hundred forty-four prostate cancer survivors who participated in a clinical trial of behavioral intervention to UI as intervention or control subjects.Methods: The participants had a 3-month behavioral intervention or usual care and were followed up for an additional 3?months. They were assessed at baseline, 3, and 6?months. Latent growth curve models were performed to examine trajectories of each study variable and relationships among the variables.Findings: Increasing self-efficacy and social support were significantly and independently associated with more reduction of urinary leakage frequency over time.Implications for psychosocial oncology: Providing problem-solving skills and social support, including peer support, are essential for empowering patients to reduce UI. 相似文献
4.
Lalia Y. Ibrahim Krank P. DiFilippo Geremy E. Steed Manuel D. Cerqueira 《Journal of nuclear cardiology》2006,13(6):855-866
Conclusion Several quality-control measures take place before (patient and camera preparation) and during SPECT acquisition to achieve
high-quality images. Not uncommonly, technologists and physicians are left with suboptimal images that have to be addressed
to reach the “right answer” for patient diagnosis and hence management. In many cases patients may be reimaged, especially
if the problem is detected early, but in other cases either the patient has left the nuclear laboratory or there is an inevitable
problem that, even with reimaging, will not be resolved. In these situations the technologist and physician have to seek the
available techniques to obtain the best images possible. These resources are discussed in this issue as an aid in quality
control to obtain the best possible images. 相似文献
5.
A 27-year-old man was admitted with high fever and shivers eleven days after returning from vacation in Indonesia. Physical examination, laboratory values, abdominal ultrasound, and chest x-ray were not conclusive. All blood cultures yielded growth of Salmonella enterica serovar Typhi, and typhoid fever was diagnosed. Subsequently, the patient developed septic shock and pulmonary edema.In this case report epidemiological, clinical, and therapeutic aspects of typhoid fever are discussed with special emphasis on criteria for severe typhoid fever, which is treated with additional glucocorticoids. 相似文献
6.
7.
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.
10.