全文获取类型
收费全文 | 201篇 |
免费 | 22篇 |
国内免费 | 3篇 |
专业分类
基础医学 | 31篇 |
口腔科学 | 92篇 |
临床医学 | 5篇 |
内科学 | 36篇 |
皮肤病学 | 1篇 |
神经病学 | 3篇 |
特种医学 | 8篇 |
外科学 | 8篇 |
综合类 | 11篇 |
预防医学 | 4篇 |
药学 | 25篇 |
中国医学 | 1篇 |
肿瘤学 | 1篇 |
出版年
2023年 | 5篇 |
2022年 | 11篇 |
2021年 | 10篇 |
2020年 | 5篇 |
2019年 | 4篇 |
2018年 | 5篇 |
2017年 | 6篇 |
2016年 | 4篇 |
2015年 | 6篇 |
2014年 | 9篇 |
2013年 | 12篇 |
2012年 | 9篇 |
2011年 | 11篇 |
2010年 | 14篇 |
2009年 | 7篇 |
2008年 | 8篇 |
2007年 | 8篇 |
2006年 | 5篇 |
2005年 | 6篇 |
2004年 | 8篇 |
2003年 | 7篇 |
2002年 | 4篇 |
2001年 | 4篇 |
2000年 | 4篇 |
1999年 | 7篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1996年 | 1篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1992年 | 4篇 |
1991年 | 6篇 |
1989年 | 3篇 |
1988年 | 3篇 |
1987年 | 1篇 |
1986年 | 4篇 |
1985年 | 1篇 |
1979年 | 3篇 |
1978年 | 3篇 |
1977年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有226条查询结果,搜索用时 15 毫秒
21.
H.P.J. BENNETT N.G. SEIDAH S. BENJANNET S. SOLOMON M. CHRETIEN 《Chemical biology & drug design》1986,27(3):306-313
The cystine bridge structure of the amino-terminal fragment of human proopiomelanocortin has been reinvestigated. Highly purified amino-terminal fragment 1–76 was rapidly isolated from human pituitaries using only reverse-phase liquid chromatography (RP-HPLC). This peptide was then subjected to trypsin and V8-protease digestion and the products separated by RP-HPLC> and subjected to amino acid and microsequence analysis. The results show that disulfide bridges link Cys-2 to Cys-24 and Cys-8 to Cys-20. Amino acid analysis and amino sugar determination confirm (i) the previously proposed sequence and (ii) the suggestion of the presence of two glycosylation sites in this molecule. These are most probably located at Thr-45 (O-glycosylation) and at Asn-65 (N-glycosylation). 相似文献
22.
《Vaccine》2018,36(42):6345-6353
The broadly neutralizing antibody against HIV-1, b12, binds to the CD4 binding site (CD4bs) on the outer domain (OD) of the gp120 subunit of HIV-1 Env. We have previously reported the design of an E. coli expressed fragment of HIV-1 gp120, b122a, containing about 70% of the b12 epitope with the idea of focusing the immune response to this structure. Since the b122a structure was found to be only partially folded, as assessed by circular dichroism and protease resistance, we attempted to stabilize it by the introduction of additional disulfide bonds. One such mutant, b122a1-b showed increased stability and bound b12 with 30-fold greater affinity as compared to b122a. Various b122a and OD fragment proteins were displayed on the surface of Qβ virus-like particles. Sera raised against these particles in six-month long rabbit immunization studies could neutralize Tier1 viruses across different subtypes with the best results observed with b122a1-b displayed particles. Significantly higher amounts of antibodies directed towards the CD4bs were also elicited by particles displaying b122a1-b. This study highlights the ability of fragment immunogens to focus the antibody response to the conserved CD4bs of HIV-1. 相似文献
23.
24.
The aim of the present investigation was to find out to what extent the magnitudes of chewing and biting forces in dentitions restored with cross-arch bilateral end abutment bridges are correlated to the areas of the periodontal ligament supporting the abutment teeth. 12 subjects whose dentitions had been periodontally treated and prosthetically restored participated in the study. The chewing and biting forces were measured in various parts of as well as over the entire dentition simultaneously using 4 strain gauge transducers bilaterally placed in pontics of the posterior (first molar/second premolar) and anterior regions. Based on calculations of the periodontal ligament areas, a new periodontal support index, PSIL, is introduced. This index expresses the relation between the total remaining periodontal ligament area supporting the bridge abutments and total maximal periodontal ligament area if all teeth were preserved as abutments. It is compared with the index of Ante, PSIA, which expresses the relation between the total remaining periodontal ligament area of all abutments and the total maximal periodontal ligament area of all replaced teeth. Within the present group of subjects, PSIL varied from 10 to 44% and PSIA from 17 to 118%. Based on the results of the correlation analyses, it is suggested that in dentitions restored with cross-arch bilateral end abutment bridges, the magnitude of the chewing forces is positively correlated to the areas of the periodontal ligament supporting the bridge abutments, whereas the periodontal ligament areas have no influence on the comparatively larger biting forces. The relevance of the 2 periodontal support indices and the clinical implications of the results of the study are discussed. 相似文献
25.
Summary The objective of this report is to summarize the results on survival and complication rates of different designs of fixed dental prostheses (FDP) published in a series of systematic reviews. Moreover, the various parameters for survival and risk assessment are to be used in attempt to perform treatment planning on the basis of scientific evidence. Three electronic searches complemented by manual searching were conducted to identify prospective and retrospective cohort studies on FDP and implant-supported single crowns (SC) with a mean follow-up time of at least 5 years. Patients had to have been examined clinically at the follow-up visit. Failure and complication rates were analyzed using random-effects Poisson regression models to obtain summary estimates of 5- and 10-year survival proportions. Meta-analysis of the studies included indicated an estimated 5-year survival of conventional tooth-supported FDP of 93·8%, cantilever FDP of 91·4%, solely implant-supported FDP of 95·2%, combined tooth-implant-supported FDP of 95·5% and implant-supported SC of 94·5% as well as resin-bonded bridges 87·7%. Moreover, after 10 years of function the estimated survival decreased to 89·2% for conventional FDP, to 80·3% for cantilever FDP, to 86·7% for implant-supported FDP, to 77·8% for combined tooth-implant-supported FDP, to 89·4% for implant-supported SC and to 65% for resin-bonded bridges. When planning prosthetic rehabilitations, conventional end-abutment tooth-supported FDP, solely implant-supported FDP or implant-supported SC should be the first treatment option. Only as a second option, because of reasons such as financial aspects patient-centered preferences or anatomical structures cantilever tooth-supported FDP, combined tooth-implant-supported FDP or resin-bonded bridges should be chosen. 相似文献
26.
27.
Objectives: Appraise the feasibility of interchanging conventional components of a fixed dental prosthesis (FDP) with those of Cresco in two different early loading protocols. Material and methods: In five centers patients with an edentulous, fully healed maxilla were recruited to partake in a three‐arm blinded randomized‐controlled trial (RCT). Each patient received 5/6 implants using a single‐stage surgery approach to support a 10/12‐unit FDP. The implants used were SLA solid screw two‐part implants. In test groups 1 and 2 components from Cresco were used and the implants loaded 10 days or 6–8 weeks post‐implant placement. Group 3 received their FDP fabricated with conventional components 6–8 weeks post‐implant placement. Patients were followed up 3 years. Results: Of 36 patients, 30 remained after 3 years. The adjusted means and ranges of changes in crestal bone levels were ?0.65, ?0.5 and ?0.4 mm in groups 1, 2 and 3, respectively. The change from baseline was statistically significant in all treatment groups. Adjusting for the difference in implant depth, there was an expected additional change in bone level of ?0.29 mm by each 1 mm the implant was placed deeper. There was no significant difference between the 6‐8 weeks post‐implant placement loading Cresco group vs. the control group or between the two Cresco groups. Conclusions: The vertical placement has more effect on bone loss than the fabrication technique used for the suprastructure and whether the implants were loaded after 10 days vs. 6–8 weeks. To cite this article :Jokstad A, Ellner S, Gussgard A. Comparison of two early loading protocols in full arch reconstructions in the edentulous maxilla using the Cresco prosthetic system: a three‐arm parallel group randomized‐controlled trial.Clin. Oral Impl. Res. 22 , 2011; 455–463.doi: 10.1111/j.1600‐0501.2010.02156.x 相似文献
28.
29.
30.
两种义齿修复下颌单侧游离端缺失基牙及缺牙区牙槽嵴应力分布的比较 总被引:2,自引:1,他引:1
目的:分析两种不同结构义齿修复单侧游离端缺失时基牙及缺牙区牙槽嵴应力分布特点,为临床义齿选择提供依据。 方法:应用三维有限元方法分别测定并比较应用键槽缓冲式附着体义齿和单端固定桥义齿修复单侧游离端缺失时基牙及缺牙区牙槽嵴应力分布情况。结果: 键槽缓冲式附着体义齿基牙牙根应力峰值(1.42E+5)MPa,基牙牙周膜应力峰值(1.33E+4)MPa,缺牙区牙槽嵴应力峰值(3.49E+5)MPa。单端固定桥义齿基牙牙根应力峰值(1.45E+7)MPa,基牙牙周膜应力峰值(2.25E+6)MPa,缺牙区牙槽嵴应力峰值(1.45E+3)MPa。两种义齿基牙应力峰值均在根中、上1/3及颈部。结论:在游离端缺失修复时, 键槽缓冲式附着体义齿可减少基牙负荷,但牙槽嵴条件要好,两种义齿修复均要注意牙槽嵴健康。 相似文献