全文获取类型
收费全文 | 2866篇 |
免费 | 166篇 |
国内免费 | 27篇 |
专业分类
耳鼻咽喉 | 19篇 |
儿科学 | 157篇 |
妇产科学 | 222篇 |
基础医学 | 318篇 |
口腔科学 | 44篇 |
临床医学 | 191篇 |
内科学 | 522篇 |
皮肤病学 | 45篇 |
神经病学 | 101篇 |
特种医学 | 201篇 |
外科学 | 391篇 |
综合类 | 177篇 |
一般理论 | 1篇 |
预防医学 | 133篇 |
眼科学 | 72篇 |
药学 | 144篇 |
中国医学 | 42篇 |
肿瘤学 | 279篇 |
出版年
2023年 | 12篇 |
2022年 | 25篇 |
2021年 | 46篇 |
2020年 | 42篇 |
2019年 | 53篇 |
2018年 | 57篇 |
2017年 | 52篇 |
2016年 | 67篇 |
2015年 | 87篇 |
2014年 | 94篇 |
2013年 | 111篇 |
2012年 | 148篇 |
2011年 | 145篇 |
2010年 | 130篇 |
2009年 | 115篇 |
2008年 | 103篇 |
2007年 | 105篇 |
2006年 | 113篇 |
2005年 | 102篇 |
2004年 | 84篇 |
2003年 | 70篇 |
2002年 | 61篇 |
2001年 | 66篇 |
2000年 | 68篇 |
1999年 | 89篇 |
1998年 | 75篇 |
1997年 | 89篇 |
1996年 | 76篇 |
1995年 | 48篇 |
1994年 | 50篇 |
1993年 | 64篇 |
1992年 | 37篇 |
1991年 | 44篇 |
1990年 | 44篇 |
1989年 | 63篇 |
1988年 | 39篇 |
1987年 | 35篇 |
1986年 | 35篇 |
1985年 | 34篇 |
1984年 | 18篇 |
1982年 | 20篇 |
1981年 | 21篇 |
1980年 | 16篇 |
1979年 | 24篇 |
1977年 | 15篇 |
1976年 | 13篇 |
1974年 | 13篇 |
1973年 | 12篇 |
1972年 | 16篇 |
1966年 | 11篇 |
排序方式: 共有3059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.
Suppurative corneal ulceration in Bangladesh 总被引:8,自引:0,他引:8
AAS Dunlop MB BS ED Wright MRCPath † SA Howlader‡ I Nazrul‡ R Husain‡ K McClellan FRACO § FA Billson FRACO § 《Clinical & experimental ophthalmology》1994,22(2):105-110
Suppurative keratitis is an important preventable cause of blindness, particularly in the developing world. This study analyses 142 cases of suppurative keratitis referred to Chittagong Eye Infirmary, Bangladesh. Some 53.5% of cases were bacterial and 35.9% were fungal. The five most common pathogens were: Pseudomonas sp. 24%, Streptococcus pneumoniae 17%, Aspergillus sp. 13%, Fusarium sp. 7% and Curvularia sp. 6%. Gram stain and culture results were consistent in 62.6% of cases. Previous antibiotic treatment was a significant factor for failure of culture isolation and less so for Gram stain failure. On Gram stain, 55.9% of pseudomonal cases were missed, but only 2% of fungal cases were missed. Over all, Gram stain had a sensitivity of 62% and positive predictive value of 84% for bacterial cases, and 98% and 94% for fungal cases, respectively. Fungal ulcers were typically filamentous, but an antecedent history of trauma was not common. The most frequent injury was due to rice grains, but the inoculum appeared to be introduced during eye washing with contaminated water. Pseudomonal ulcers occurred most frequently in the monsoon season, and Fusarium cases were seen only in the hot, dry season. 相似文献
3.
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
4.
5.
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
6.
7.
8.
Nonheme iron in sickle erythrocyte membranes: association with phospholipids and potential role in lipid peroxidation 总被引:5,自引:0,他引:5
Previous studies documented the abnormal association of heme and heme proteins with the sickle RBC membrane. We have now examined RBC ghosts and inside-out membranes (IOM) for the presence of nonheme iron as detected by its formation of a colored complex with ferrozine. Sickle ghosts have 33.8 +/- 18.2 nmol nonheme iron/mg membrane protein, and sickle IOM have 4.3 +/- 3.0 nmol/mg. In contrast, normal RBC ghosts and IOM have no detectable nonheme iron. The combination of heme and nonheme iron in sickle IOM averages nine times the amount of membrane- associated iron in normal IOM. Kinetics of the ferrozine reaction show that some of this nonheme iron on IOM reacts slowly and is probably in the form of ferritin, but most (72% +/- 18%) reacts rapidly and is in the form of some other biologic chelate. The latter iron compartment is removed by deferoxamine and by treatment of IOM with phospholipase D, which suggests that it represents an abnormal association of iron with polar head groups of aminophospholipids. The biologic feasibility of such a chelate was demonstrated by using an admixture of iron with model liposomes. Even in the presence of tenfold excess adenosine diphosphate, iron partitions readily into phosphatidylserine liposomes; there is no detectable association with phosphatidylcholine liposomes. To examine the bioavailability of membrane iron, we admixed membranes and t-butylhydroperoxide and found that sickle membranes show a tenfold greater peroxidation response than do normal membranes. This is not due simply to a deficiency of vitamin E, and this is profoundly inhibited by deferoxamine. Thus, while thiol oxidation in sickle membranes previously was shown to correlate with heme iron, the present data suggest that lipid peroxidation is related to nonheme iron. In control studies, we did not find this pathologic association of nonferritin, nonheme iron with IOM prepared from sickle trait, high-reticulocyte, postsplenectomy, or iron-overloaded individuals. These data provide additional support for the concept that iron decompartmentalization is a characteristic of sickle RBCs. 相似文献
9.
10.