全文获取类型
收费全文 | 16355篇 |
免费 | 775篇 |
国内免费 | 18篇 |
专业分类
耳鼻咽喉 | 471篇 |
儿科学 | 513篇 |
妇产科学 | 665篇 |
基础医学 | 1482篇 |
口腔科学 | 290篇 |
临床医学 | 1456篇 |
内科学 | 3600篇 |
皮肤病学 | 382篇 |
神经病学 | 1134篇 |
特种医学 | 912篇 |
外科学 | 3092篇 |
综合类 | 147篇 |
一般理论 | 8篇 |
预防医学 | 908篇 |
眼科学 | 422篇 |
药学 | 733篇 |
中国医学 | 4篇 |
肿瘤学 | 929篇 |
出版年
2021年 | 101篇 |
2020年 | 67篇 |
2019年 | 98篇 |
2018年 | 164篇 |
2017年 | 123篇 |
2016年 | 142篇 |
2015年 | 624篇 |
2014年 | 767篇 |
2013年 | 816篇 |
2012年 | 967篇 |
2011年 | 946篇 |
2010年 | 809篇 |
2009年 | 731篇 |
2008年 | 933篇 |
2007年 | 879篇 |
2006年 | 855篇 |
2005年 | 779篇 |
2004年 | 707篇 |
2003年 | 435篇 |
2002年 | 380篇 |
2001年 | 373篇 |
2000年 | 346篇 |
1999年 | 343篇 |
1998年 | 145篇 |
1997年 | 141篇 |
1996年 | 157篇 |
1995年 | 146篇 |
1994年 | 128篇 |
1993年 | 124篇 |
1992年 | 352篇 |
1991年 | 329篇 |
1990年 | 279篇 |
1989年 | 295篇 |
1988年 | 219篇 |
1987年 | 234篇 |
1986年 | 214篇 |
1985年 | 187篇 |
1984年 | 149篇 |
1983年 | 156篇 |
1982年 | 118篇 |
1981年 | 89篇 |
1980年 | 101篇 |
1979年 | 155篇 |
1978年 | 99篇 |
1977年 | 72篇 |
1975年 | 85篇 |
1974年 | 100篇 |
1973年 | 77篇 |
1972年 | 76篇 |
1971年 | 68篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
Timo Rath Lukas Pfeifer Clemens Neufert reas Kremer Moritz Leppkes Arthur Hoffman Markus F Neurath Steffen Zopf 《World journal of gastroenterology : WJG》2020,26(16):1962-1970
BACKGROUND The adenoma detection rate(ADR) is inversely associated with the incidence of interval colorectal cancer and serves as a benchmark quality criterion during screening colonoscopy. However, adenoma miss rates reach up to 26% and studies have shown that a second inspection of the right colon in retroflected view(RFV) can increase ADR.AIM To assess whether inspection of the whole colon in RFV compared to standard forward view(SFV) can increase ADR.METHODS Patients presenting for screening or surveillance colonoscopy were invited to participate in this randomized controlled trial and randomized into two arms. In RFV arm colonoscopy was initially performed with SFV, followed by a second inspection of the whole colon in RFV. In the SFV arm first withdrawal was performed with SFV, followed by a second inspection of the whole colon again with SFV. Number, size and morphology of polyps found during first and second inspection in each colonic segment were recorded and all polyps were removed and sent for histopathology in separate containers.RESULTS Two hundred and five patients were randomly assigned to the RFV(n = 101) and SFV(n = 104) arm. In the RFV arm, both polyp detection rate(PDR) and ADR were increased under second inspection in RFV(PDR 1~(st) SFV: 39.8%, PDR 2~(nd)RFV: 46.6%; ADR 1~(st) SFV: 35.2%, ADR 2~(nd) RFV: 42%). Likewise, in the SFV arm,PDR and ADR were increased under second inspection(PDR 1~(st) SFV: 37.5%, PDR 2~(nd) SFV: 46.6%; ADR 1~(st) SFV: 34.1%, ADR 2~(nd)SFV: 44.3%) with no significant differences in ADR and PDR between the SFV and RFV arm. Mean number of adenomas per patient(APP) was increased in the RFV and SFV(APP RFV arm: 1~(st) SFV: 1.71; 2~(nd) RFV: 2.38; APP SFV arm: 1~(st) SFV: 1.83, 2~(nd)SFV:2.2). The majority of adenomas additionally found during second inspection in RFV or in SFV were located in the transverse and left-sided colon and were 5 mm in size.CONCLUSION Second inspection of the whole colon leads to increased adenoma detection with no differences between SFV and RFV. Hence, increased detection is most likely a feature of the second inspection itself but not of the inspection mode. 相似文献
2.
Well‐being,health and fitness of children who use wheelchairs: Feasibility study protocol to develop child‐centred ‘keep‐fit’ exercise interventions
下载免费PDF全文
![点击此处可从《Journal of advanced nursing》网站下载免费的PDF全文](/ch/ext_images/free.gif)
3.
4.
5.
Chronic transplant dysfunction is a complex dynamic pathogenic process. Clinically, a decrease in glomerular filtration rate (GFR) becomes apparent leading to chronic renal insufficiency and dialysis or death from cardiovascular events. Chronic transplant dysfunction can develop into a chronic alIograft nephropathy (CAN) as a specific entity with dynamic progression. CAN includes a collection of immunologic and non-immunologic factors, rejection, ischemia time, donor and recipient characteristics and toxicity of calcineurin inhibitors. Despite improvements in immunosuppression, the long-range prognosis of renal allografts has not improved. Whether modern immunosuppressive concepts with reduction or avoidance of calcineurin inhibitors and a therapy based on antimetabolites, such as mycophenolate or mTOR-inhibitors could lead to a prolongation of transplant survival, remains to be seen. 相似文献
6.
7.
8.
9.
10.
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