全文获取类型
收费全文 | 47712篇 |
免费 | 4438篇 |
国内免费 | 3642篇 |
专业分类
耳鼻咽喉 | 301篇 |
儿科学 | 431篇 |
妇产科学 | 483篇 |
基础医学 | 5639篇 |
口腔科学 | 745篇 |
临床医学 | 6902篇 |
内科学 | 7462篇 |
皮肤病学 | 586篇 |
神经病学 | 2603篇 |
特种医学 | 1921篇 |
外国民族医学 | 23篇 |
外科学 | 4373篇 |
综合类 | 7691篇 |
现状与发展 | 15篇 |
一般理论 | 7篇 |
预防医学 | 2920篇 |
眼科学 | 1469篇 |
药学 | 5025篇 |
81篇 | |
中国医学 | 2847篇 |
肿瘤学 | 4268篇 |
出版年
2024年 | 153篇 |
2023年 | 863篇 |
2022年 | 2043篇 |
2021年 | 2631篇 |
2020年 | 1964篇 |
2019年 | 1665篇 |
2018年 | 1757篇 |
2017年 | 1512篇 |
2016年 | 1455篇 |
2015年 | 2165篇 |
2014年 | 2637篇 |
2013年 | 2332篇 |
2012年 | 3456篇 |
2011年 | 3882篇 |
2010年 | 2360篇 |
2009年 | 1848篇 |
2008年 | 2475篇 |
2007年 | 2543篇 |
2006年 | 2471篇 |
2005年 | 2566篇 |
2004年 | 1483篇 |
2003年 | 1329篇 |
2002年 | 1108篇 |
2001年 | 1099篇 |
2000年 | 1145篇 |
1999年 | 1207篇 |
1998年 | 787篇 |
1997年 | 800篇 |
1996年 | 617篇 |
1995年 | 568篇 |
1994年 | 514篇 |
1993年 | 300篇 |
1992年 | 378篇 |
1991年 | 308篇 |
1990年 | 282篇 |
1989年 | 242篇 |
1988年 | 230篇 |
1987年 | 208篇 |
1986年 | 154篇 |
1985年 | 110篇 |
1984年 | 50篇 |
1983年 | 38篇 |
1982年 | 19篇 |
1981年 | 12篇 |
1980年 | 13篇 |
1979年 | 12篇 |
1966年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 363 毫秒
1.
Vincent Chung Liang Liu Zhaoxiang Bian Zhongzhen Zhao Wai Leuk Fong Wan Fung Kum Jing Gao Min Li 《Movement disorders》2006,21(10):1709-1715
The objective of this study is to assess the efficacy and safety of herbal medicines (HMs), as a monotherapy or adjunct therapy, compared to placebo or conventional approaches in the treatment of idiopathic Parkinson's disease (PD). We conducted a systematic review of randomized controlled trials from both conventional and alternative medicine sources. Outcome measures were overall improvement, quality of life, reduction of levodopa dose, and adverse events. Nine studies were included, each testing a different HM. Six of the trials had limited internal validity due to major flaws in design, including the lack of proper randomization; insufficient blinding; unclear inclusive criteria in terms of diagnostic criteria, baseline staging, and duration of disease; lack of proper sample size calculation; and insufficient data analysis. Imbalances in gender and ethnicity among the patients in the included trials were observed. No major adverse events emerged, and no specific pattern was detected from the trials describing such data. In addition to major methodological defects, heterogeneity in (1) HM tested, (2) control treatment, and (3) outcome measure hindered in-depth data analysis and synthesis. Current evidence is insufficient to evaluate the efficacy and safety of various HMs. Further studies with improved trial design and reporting, with assessment on cost-effectiveness, quality of life, and qualitative data are warranted. 相似文献
2.
3.
4.
We report a case of extragastrointestinal stromal tumor possibly originating from the prostate. The patient underwent radical prostatectomy because of no metastatic evidence. No recurrence and metastasis have been found during 14 months of follow up. To our knowledge, this may be the third such case published in a report in terms of pathological type. 相似文献
5.
6.
Amrik Sahota Min Yang Sujuan Gao Siu L. Hui Olusegun Baiyewu Oyewusi Gureje Steven Oluwole Adesola Ogunniyi Kathleen S. Hall Hugh C. Hendrie 《Annals of neurology》1997,42(4):659-661
As a part of our ongoing study on Alzheimer's disease (AD) in elderly African Americans, we obtained clinical assessment and apolipoprotein E (ApoE) genotype data on 288 individuals (including 60 with AD). The ApoE σ4 allele frequency was significantly increased in AD patients compared with controls. The age-adjusted odds ratio (OR) for AD in σ4 homozygotes was 4.83 (95% confidence interval [CI], 1.71–13.64) compared with the σ3/σ3 genotype, but the OR for AD with the σ3/σ4 genotype did not reach significance (1.20; 95% CI, 0.58–2.45). These findings suggest that the association between ApoE σ4 and AD is weaker in African Americans than in whites. 相似文献
7.
Fan Gao Mark L Latash Vladimir M Zatsiorsky 《Journal of hand therapy》2007,20(4):300-7; quiz 308; discussion 309
The tight coupling between load (L) and grip (G) forces during voluntary manipulation of a hand-held object is well established. The current study is to examine grip-load force coupling when motion of the hand with an object was either self-generated (voluntary) or externally generated. Subjects performed similar cyclic movements of different loads at various frequencies with three types of manipulations: 1) voluntary oscillation, 2) oscillating the right arm via the pulley system by the left leg (self-driven oscillation), and 3) oscillating the arm via the pulley system by another person (other-driven oscillation). During the self-generated movements: 1) the grip forces were larger and 2) grip-load force modulation was more pronounced than in the externally generated movements. The G-L adjustments are not completely determined by the mechanics of object motion; nonmechanical factors related to movement performance, for instance perceptual factors, may affect the G-L coupling. 相似文献
8.
9.
Alex Zacharek Jieli Chen Xu Cui Ang Li Yi Li Cynthia Roberts Yifan Feng Qi Gao Michael Chopp 《Journal of cerebral blood flow and metabolism》2007,27(10):1684-1691
Bone marrow stromal cells (MSCs) increase vascular endothelial growth factor (VEGF) expression and promote angiogenesis after stroke. Angiopoietin-1 (Ang1) and its receptor Tie2 mediate vascular integrity and angiogenesis as does VEGF and its receptors. In this study, we tested whether MSC treatment of stroke increases Ang1/Tie2 expression, and whether Ang1/Tie2 with VEGF/ vascular endothelial growth factor receptor 2 (VEGFR2) (Flk1), in combination, induced by MSCs enhances angiogenesis and vascular integrity. Male Wistar rats were subjected to middle cerebral artery occlusion (MCAo) and treated with or without MSCs. Marrow stromal cell treatment significantly decreased blood-brain barrier (BBB) leakage and increased Ang1, Tie2, and occludin (a tight junction protein) expression in the ischemic border compared with MCAo control. To further test the mechanisms of MSC-induced angiogenesis and vascular stabilization, cocultures of MSCs with mouse brain endothelial cells (MBECs) or astrocytes were performed. Supernatant derived from MSCs cocultured with MBECs significantly increased MBEC expression of Ang1/Tie2 and Flk1 compared with MBEC alone. Marrow stromal cells cocultured with astrocytes also significantly increased astrocyte VEGF and Ang1/Tie2 expression compared with astrocyte culture alone. Conditioned media from MSCs alone, and media from cocultures of MSCs with astrocytes or MBECs, all significantly increased capillary tube-like formation of MBEC compared with control Dulbecco's modified Eagle's medium media. Inhibition of Flk1 and/or Ang1 significantly decreased MSC-induced MBEC tube formation. Knockdown of Tie2 expression in MBECs significantly inhibited MSC-induced tube formation. Our data indicate MSC treatment of stroke promotes angiogenesis and vascular stabilization, which is at least partially mediated by VEGF/Flk1 and Ang1/Tie2. 相似文献
10.
表皮生长因子及其受体与流产关系的探讨 总被引:4,自引:0,他引:4
采用放射免疫竞争抑制饱和分析法,检测47例难免流产患者,65例人工流产及20例健康非孕妇女血清表皮生长因子(EGF)水平;同时采用免疫组织化学法检测流产者胚胎组织中表皮生长因子受体(EGFR)表达程度。结果:人工流产组血清EGF水平高于自然流产及非孕妇女,而自然流产与非孕妇女差异无显著性;胚胎组织中EGFR阳性表达率人工流产组明显高于自然流产组。提示:EGF通过与其受体结合对妊娠维持、胚胎及胎儿的 相似文献