全文获取类型
收费全文 | 3591篇 |
免费 | 181篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 79篇 |
儿科学 | 177篇 |
妇产科学 | 227篇 |
基础医学 | 458篇 |
口腔科学 | 80篇 |
临床医学 | 211篇 |
内科学 | 664篇 |
皮肤病学 | 39篇 |
神经病学 | 202篇 |
特种医学 | 131篇 |
外科学 | 554篇 |
综合类 | 82篇 |
一般理论 | 2篇 |
预防医学 | 160篇 |
眼科学 | 116篇 |
药学 | 276篇 |
中国医学 | 19篇 |
肿瘤学 | 310篇 |
出版年
2023年 | 18篇 |
2022年 | 48篇 |
2021年 | 76篇 |
2020年 | 46篇 |
2019年 | 89篇 |
2018年 | 93篇 |
2017年 | 80篇 |
2016年 | 98篇 |
2015年 | 106篇 |
2014年 | 113篇 |
2013年 | 161篇 |
2012年 | 233篇 |
2011年 | 239篇 |
2010年 | 133篇 |
2009年 | 117篇 |
2008年 | 167篇 |
2007年 | 173篇 |
2006年 | 170篇 |
2005年 | 169篇 |
2004年 | 151篇 |
2003年 | 138篇 |
2002年 | 107篇 |
2001年 | 83篇 |
2000年 | 88篇 |
1999年 | 85篇 |
1998年 | 41篇 |
1997年 | 36篇 |
1996年 | 35篇 |
1995年 | 19篇 |
1994年 | 19篇 |
1993年 | 38篇 |
1992年 | 43篇 |
1991年 | 53篇 |
1990年 | 49篇 |
1989年 | 47篇 |
1988年 | 27篇 |
1987年 | 24篇 |
1986年 | 27篇 |
1985年 | 32篇 |
1984年 | 14篇 |
1983年 | 18篇 |
1981年 | 20篇 |
1979年 | 33篇 |
1978年 | 19篇 |
1976年 | 16篇 |
1974年 | 20篇 |
1973年 | 15篇 |
1972年 | 16篇 |
1971年 | 18篇 |
1969年 | 16篇 |
排序方式: 共有3787条查询结果,搜索用时 15 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.
Vascular anatomy of the pronator quadratus muscle-bone flap: a justification for its use with a distally based blood supply 总被引:1,自引:0,他引:1
The vascular anatomy of the pronator quadratus muscle and distal radius was studied in 24 cadaveric forearms by dissection under magnification and india ink and latex injection studies. The anterior interosseous artery divides into a muscular branch and a dorsal branch 1 cm to 3.5 cm from the proximal margin of the pronator quadratus muscle, and on its deep surface. Injection studies showed a rich periosteal plexus contributed by the anterior interosseous artery. Retrograde injection through the dorsal branch also showed good perfusion of the distal radius that was confirmed microscopically on bone sections. A muscle-bone graft from the anteromedial cortex of distal radius with an intact anterior interosseous artery has mobility of less than 2 cm. After ligating and dividing the anterior interosseous artery, blood supply to the distal radius bone flap relies on a retrograde flow and the bone flap could then be mobilized distally up to 4 to 6 cm. 相似文献
3.
The Authors discuss their experience with the use of various flaps (radial artery, groin and abdomen) in the primary or delayed cover of skin defect in the hand, in a total number of 20 cases. All the three types of flaps took up well in 3-4 weeks with minimal complications. The Authors preferred the radial artery flap to the groin and abdominal flaps, in that order. 相似文献
4.
5.
Brian F O'Reilly Ameet Kishore John A Crowther Colin Smith 《Otology & neurotology》2004,25(5):791-796
OBJECTIVE: To examine the relationship between growth rate of vestibular schwannomas and the expression of various growth factor receptors. STUDY DESIGN: Retrospective case review of clinical growth rate in conjunction with a histopathologic and immunohistochemical reexamination of archival specimens. SETTING: A tertiary referral neurotologic center. PATIENTS: Three groups: a historical group to act as controls, consisting of 30 patients with sporadic vestibular schwannomas removed before the unit adopted an initial interval scan policy; a group of 14 patients with sporadic vestibular schwannomas who had undergone an initial interval scan policy, showed radiologic evidence of growth, and therefore had their schwannoma removed; and a group of 16 schwannomas removed from 11 neurofibromatosis Type 2 patients. MAIN OUTCOME MEASURES: A comparison between the three clinical groups using immunohistochemical studies to determine the level of expression of the proliferation factor Ki-67, c-erbB-2, and c-erbB-3 receptors and fibroblastic growth factor receptors 1 and 4. RESULTS: The level of expression of the proliferation factor Ki-67 was very low and similar in all three groups. C-erbB-2 and c-erbB-3 receptors were not expressed in any of the groups. fibroblastic growth factor receptor 4 expression was not significantly different, but there was a variation in the expression of fibroblastic growth factor receptor 1 between the three groups that correlated well with the differing incidence of growth in the groups. The increase in expression of fibroblastic growth factor receptor 1 in the neurofibromatosis Type 2 group was not statistically significant, but the increase in expression of fibroblastic growth factor receptor 1 in the growing sporadic group was statistically significant when compared with the historical controls. The level of fibroblastic growth factor receptor 1 expression correlates significantly with the rate of growth as measured on interval magnetic resonance imaging. CONCLUSIONS: Overexpression of fibroblastic growth factor receptor 1 has a positive correlation with the incidence and the rate of growth of sporadic vestibular schwannomas. 相似文献
6.
7.
8.
S Bauer I Wolff N Werner P Hoffmann R Herzschuh K Oemus F W Rath R Voigt 《Toxicology and industrial health》1992,8(3):141-156
In dry etching processes--one of the sources of potential exposure to toxic wastes in the semiconductor industry--complex mixtures of inorganic and organic compounds arise from reactions between feed stock gases (BCl3/Cl2), top layers (aluminium photoresist), and the carrier gas (N2). Two different fractions of the complex mixture--one an ethanolic solution (ES) and the other an insoluble liquid residue (LR)--were examined for acute oral toxicity in rats. Analytical data showed that the ethanol soluble fraction contained mainly inorganic compounds, whereas the residue contained various halogenated hydrocarbons. Neither death nor behavioral changes occurred after oral administration and observation up to 23 days. ES caused a lower mean arterial blood pressure in both sexes, increased P-R-intervals in male rats, and caused some mild biochemical and hematological alterations and changes in relative organ weights compared to the control groups. Exposure to LR influenced food and water intake, and caused a significant decrease in body weights, signs of polyurie, as well as changes in various relative organ weights and biochemical and hematological parameters. The blood pressure of the male animals fell and the heart rates of both sexes decreased. 相似文献
9.
Exclusive expression of MHC class II proteins on CD45+ cells in pancreatic islets of NOD mice. 总被引:6,自引:0,他引:6
The expression of MHC class II molecules on beta-cells of the pancreatic islet has been proposed to play a role in the genesis of insulin-dependent diabetes mellitus in the NOD mouse. We investigated this by immunofluorescent double labeling of islet cells with anti-MHC and anti-CD45 to identify cells of hematopoietic origin. MHC class I expression increased with age on CD45- islet cells. MHC class II expression was not observed on CD45- islet cells at any age; the only cells in the islet that were MHC class II positive were also CD45+. This indicates that all MHC class II-positive cells in the islet are lymphoid cells that infiltrate the islet, whereas the islet endocrine cells express no MHC class II molecules. However, an increase in MHC class I expression occurred on beta-cells, and this may play a role in immunopathogenesis. 相似文献
10.