全文获取类型
收费全文 | 267139篇 |
免费 | 24881篇 |
国内免费 | 20716篇 |
专业分类
耳鼻咽喉 | 2038篇 |
儿科学 | 2363篇 |
妇产科学 | 3036篇 |
基础医学 | 32846篇 |
口腔科学 | 4323篇 |
临床医学 | 38581篇 |
内科学 | 38794篇 |
皮肤病学 | 2437篇 |
神经病学 | 14966篇 |
特种医学 | 9681篇 |
外国民族医学 | 199篇 |
外科学 | 25326篇 |
综合类 | 44930篇 |
现状与发展 | 75篇 |
一般理论 | 27篇 |
预防医学 | 16136篇 |
眼科学 | 8213篇 |
药学 | 28647篇 |
312篇 | |
中国医学 | 15953篇 |
肿瘤学 | 23853篇 |
出版年
2024年 | 965篇 |
2023年 | 4444篇 |
2022年 | 11552篇 |
2021年 | 14345篇 |
2020年 | 10883篇 |
2019年 | 9414篇 |
2018年 | 9799篇 |
2017年 | 8674篇 |
2016年 | 8208篇 |
2015年 | 12393篇 |
2014年 | 15208篇 |
2013年 | 12749篇 |
2012年 | 18970篇 |
2011年 | 21812篇 |
2010年 | 13240篇 |
2009年 | 10235篇 |
2008年 | 13531篇 |
2007年 | 13579篇 |
2006年 | 13784篇 |
2005年 | 13958篇 |
2004年 | 8298篇 |
2003年 | 7684篇 |
2002年 | 6463篇 |
2001年 | 5761篇 |
2000年 | 6488篇 |
1999年 | 7236篇 |
1998年 | 4766篇 |
1997年 | 4774篇 |
1996年 | 3699篇 |
1995年 | 3528篇 |
1994年 | 2907篇 |
1993年 | 1966篇 |
1992年 | 2218篇 |
1991年 | 1843篇 |
1990年 | 1566篇 |
1989年 | 1334篇 |
1988年 | 1133篇 |
1987年 | 990篇 |
1986年 | 749篇 |
1985年 | 610篇 |
1984年 | 348篇 |
1983年 | 214篇 |
1982年 | 117篇 |
1981年 | 127篇 |
1980年 | 82篇 |
1979年 | 90篇 |
1965年 | 1篇 |
1962年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
13.
Abstract: Background: Few studies have examined in depth the labor progression of multiparas to determine if there is any additional impact of being parous beyond the first birth. The objective of this study was to determine the effect of parity on labor progression in contemporary obstetric practice. Methods: Our sample consisted of all low‐risk women who delivered a term, live‐born infant from January 2002 to March 2004 at a single institution in Delaware, United States (n = 5,589). The median duration of labor by each centimeter of cervical dilation was computed for parity = 0 (n = 2,645); parity = 1 (n = 1,839); parity = 2 (n = 750); and parity = 3 + (n = 355). Results: Multiparas had a significantly faster labor progression from 4 to 10 cm (293, 300, and 313 min, respectively, for parity = 1, parity = 2, and parity = 3 +), compared with nulliparas (383 min for parity = 0), as well as a shorter second stage of labor. However, no significant differences were found in duration of the active phase or the second stage of labor among multiparas. Conclusions: Additional childbearing appears to have no effect of on the progression of labor among multiparous subgroups. The difference in duration of the active phase between nulliparas and multiparas is substantially smaller in a contemporary population. (BIRTH 33:1 March 2006) 相似文献
14.
目的:为更清晰地显示顽固性气胸的漏气部位和性质,为不能耐受手术者摸索一种新的治疗手段。方法:选择18例患者,先用76%泛影葡胺行胸膜腔造影,而后在局部注入少量粘连剂。结果:造影后发现多发性肺大泡8例,单发性肺大泡6例,肺大泡伴粘连带4例。病变分别位于左上肺,右上肺,中下肺野及叶间裂。注射粘连剂后,15例一次成功,3例第二次成功。随防6~18个月,未见复发。结论:该方法易掌握,无明显副作用。病变显示明显,易被患者接受,具有明显的临床效果和推广价值 相似文献
15.
人体蠕形螨的生物学研究 总被引:4,自引:0,他引:4
用透明胶带法观察蠕形螨在人体面部的寄生、逸出及其在体外的存活能力。结果表明:毛囊蠕形螨(Demod-exfoliculorum,D.f.)主要以颚体朝向毛囊底部寄生,且常常有多条群居现象,而皮脂蠕形螨,(Demodexbrevis,D.b.)一般为单条独居生活。两种人体蠕形螨昼夜均可主动爬出毛囊口出现在皮肤表面,D.f.以白天1000~1800为逸出高峰;D.b.则以夜间2200~200逸出最多。此外,蠕形螨在体外有较强的活动力和存活力。透明胶带法在人体蠕形螨的流行病学调查和生物学研究方面具有较高的应用价值 相似文献
16.
本实验制作不同程度心肌缺血的动物模型,以声处理5%人血白蛋白为超声造影剂进行心肌灌注造影,探讨MCE时间-强度曲线各指标与心肌缺血程度间的关系。结果表明:心肌显影的峰值强度和曲线下面积均与缺血程度呈显著负相关(相关系数分别为r=-0.98,P值<0.005;r=-0.94,P值<0.05),且能区分轻度、中度和重度三种程度的心肌缺血;而三项时间指标与心肌缺血程度间未发现显著性差异。本实验的初步结果表明,MCE是一项活体评估局部心肌血流灌注的有效方法。 相似文献
17.
Evaluation of adhesive strength of five dental adhesive cements and two visible light-activated composite resins 总被引:2,自引:0,他引:2
C X Zhang 《中华口腔医学杂志》1987,22(5):298-300
18.
19.
Xiaoguang Chen Yi Li Lei Wang Mark Katakowski Lijie Zhang Jieli Chen Yongxian Xu Subhash C. Gautam Michael Chopp 《Neuropathology》2002,22(4):275-279
Intravenous administration of human bone marrow stromal cells (hMSCs) after middle cerebral artery occlusion (MCAo) in rats provides functional benefit. We tested the hypothesis that these functional benefits are derived in part from hMSC production of growth and trophic factors. Quantitative sandwich enzyme‐linked immunosorbent assay (ELISA) of hMSCs cultured with normal and MCAo brain extracts were performed. hMSCs cultured in supernatant derived from ischemic brain extracts increased production of brain‐derived neurotrophic factor (BDNF), nerve growth factor (NGF), vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF). These neurotrophins and angiogenic growth factors increased in a post‐ischemia time‐dependent manner. The hMSC capacity to increase expression of growth and trophic factors may be the key to the benefit provided by transplanted hMSCs in the ischemic brain. 相似文献
20.
OBJECTIVE: To investigate the characteristics of the early stage treponema pallidum infected tissue in ear, nose, oropharynx and larynx and to raise relevance ratio of syphilis in nose and oropharynx and enhance doctor's self-protection awareness. METHODS: The histopathologic characteristics were studied by using HE staining, Warthin-Starry (W-S) staining was adopted to examine the treponema pallidum(TP) in lesion issue and its exudates smear for 12 cases biopsy tissues of suspicious syphilis. The diagnosis was confirmed by venereal disease research laboratory (VDRL), rapid plasma reagin circle test(RPR), treponema pallidum hemagglutination test(TPHA) and fluorescent treponemal antibody-absorption test (FTA-ABS). Treat with curing syphilis methods which published by nation. RESULTS: In the 12 cases mucous membrane specimen, the squamous epithelium proliferated, neutrophilic granulocyte infiltrated, within inherent membrane generous plasmacyte and lymphocyte infiltrated. W-S staining: plenty of treponema pallidum were found inside mucous membrane epithelium and exudate smear. Serology examination: 11 cases VDRL(++++), 7 cases RPR (+), 11 cases TPHA(+), 1 case FTA-ABS(+). After systemic treatment, 11 cases are clinically recovered. All patients serology become negative. CONCLUSION: W-S staining method can directly demonstrate histopathologic characteristics in early syphilis, in intrinsic membrane numerous plasmacyte infiltration. Combining with specific syphilis serology examination could increase diagnosis rate of syphilis in nose and oropharynx. 相似文献