全文获取类型
收费全文 | 493篇 |
免费 | 35篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 3篇 |
妇产科学 | 3篇 |
基础医学 | 80篇 |
口腔科学 | 9篇 |
临床医学 | 21篇 |
内科学 | 164篇 |
皮肤病学 | 47篇 |
神经病学 | 6篇 |
特种医学 | 63篇 |
外科学 | 37篇 |
综合类 | 6篇 |
预防医学 | 11篇 |
眼科学 | 10篇 |
药学 | 8篇 |
肿瘤学 | 60篇 |
出版年
2023年 | 5篇 |
2021年 | 15篇 |
2020年 | 4篇 |
2019年 | 7篇 |
2018年 | 21篇 |
2017年 | 7篇 |
2016年 | 20篇 |
2015年 | 16篇 |
2014年 | 20篇 |
2013年 | 21篇 |
2012年 | 35篇 |
2011年 | 39篇 |
2010年 | 24篇 |
2009年 | 21篇 |
2008年 | 31篇 |
2007年 | 34篇 |
2006年 | 28篇 |
2005年 | 23篇 |
2004年 | 23篇 |
2003年 | 19篇 |
2002年 | 17篇 |
2001年 | 4篇 |
2000年 | 2篇 |
1999年 | 7篇 |
1998年 | 4篇 |
1997年 | 7篇 |
1996年 | 5篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 4篇 |
1991年 | 4篇 |
1990年 | 8篇 |
1989年 | 8篇 |
1988年 | 9篇 |
1987年 | 6篇 |
1986年 | 6篇 |
1985年 | 9篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1929年 | 1篇 |
1909年 | 1篇 |
排序方式: 共有529条查询结果,搜索用时 46 毫秒
1.
2.
Shear bond strength of a ceramic to Co-Cr alloys 总被引:2,自引:0,他引:2
Joias RM Tango RN Junho de Araujo JE Junho de Araujo MA Ferreira Anzaloni Saavedra Gde S Paes-Junior TJ Kimpara ET 《The Journal of prosthetic dentistry》2008,99(1):54-59
STATEMENT OF PROBLEM: Different combinations of Co-Cr alloys bonded to ceramic have been used in dentistry; however, the bond strength of ceramic to metal can vary because of different compositions of these alloys. PURPOSE: The purpose of this study was to evaluate the shear bond strength of a dental ceramic to 5 commercially available Co-Cr alloys. MATERIAL AND METHODS: Five Co-Cr alloys (IPS d.SIGN 20, IPS d.SIGN 30, Remanium 2000, Heranium P, and Wirobond C) were tested and compared to a control group of an Au-Pd alloy (Olympia). Specimen disks, 5 mm high and 4 mm in diameter, were fabricated with the lost-wax technique. Sixty specimens were prepared using opaque and dentin ceramics (VITA Omega 900), veneered, 4 mm high and 4 mm in diameter, over the metal specimens (n=10). The shear bond strength test was performed in a universal testing machine with a crosshead speed of 0.5 mm/min. After shear bond testing, fracture surfaces were evaluated in a stereomicroscope under x25 magnification. Ultimate shear bond strength (MPa) data were analyzed with 1-way ANOVA and the Tukey HSD test (alpha =.05). RESULTS: The mean (SD) bond strengths (MPa) were: 61.4 (7.8) for Olympia; 94.0 (18.9) for IPS 20; 96.8 (10.2) for IPS 30; 75.1 (12.4) for Remanium; 71.2 (14.3) for Heranium P; and 63.2 (10.9) for Wirobond C. Mean bond strengths for IPS 20 and IPS 30 were not significantly different, but were significantly (P<.001) higher than mean bond strengths for the other 4 alloys, which were not significantly different from each other. CONCLUSIONS: Bond strength of a dental ceramic to a Co-Cr alloy is dependent on the alloy composition. 相似文献
3.
Ana Paula Gumieiro Jaime Diego Klee de Vasconcellos Alfredo Mikail Melo Mesquita Estev?o Tomomitsu Kimpara Marco Antonio Bottino 《Journal of applied oral science : revista FOB》2007,15(3):169-174
Objectives:
This study assessed the effect of cast rectifiers on the marginal misfit of cast UCLA abutments compared to premachined UCLA abutments. The influence of casting and porcelain baking on the marginal misfit of these components was also investigated.Methods:
Two groups were analyzed: test group – 10 cast UCLA abutments, finished with cast rectifier and submitted to ceramic application; control group – 10 premachined UCLA abutments, cast with noble metal alloy and submitted to ceramic application. Vertical misfit measurements were performed under light microscopy. In the test group, measurements were performed before and after the use of cast rectifiers, and after ceramic application. In the control group, measurements were performed before and after casting, and after ceramic application. Data were submitted to statistical analysis by ANOVA and Tukey''s test (α= 5%).Results:
The use of cast rectifiers significantly reduced the marginal misfit of cast UCLA abutments (from 25.68μm to 14.83μm; p<0.05). After ceramic application, the rectified cylinders presented misfit values (16.18μm) similar to those of premachined components (14.3 μm). Casting of the premachined UCLA abutments altered the marginal misfit of these components (from 9.63 μm to 14.6 μm; p<0.05). There were no significant changes after porcelain baking, in both groups.Conclusion:
The use of cast rectifiers reduced the vertical misfit of cast UCLA abutments. Even with carefully performed laboratory steps, changes at the implant interface of premachined UCLA abutments occurred. Ceramic application did not alter the marginal misfit values of UCLA abutments. 相似文献4.
Takashi Yahata Kiyoshi Ando Hiroko Miyatake Tomoko Uno Tadayuki Sato Mamoru Ito Shunichi Kato Tomomitsu Hotta 《Molecular therapy》2004,10(5):882-891
In multiunit cord blood transplantation, hematopoietic stem cells from each unrelated cord blood (UCB) unit competitively reconstitute the hematopoietic system in a recipient. To evaluate the fate of the progeny of each UCB unit and to determine the effects of graft-versus-graft reaction, we established a novel competitive repopulation assay using NOD/SCID/gammac(null) mice in which human T lymphocytes develop from CD34+ cells. CD34+ cells from each UCB unit were labeled with recombinant lentivirus vectors carrying genes encoding either enhanced green fluorescent protein (EGFP) or enhanced yellow fluorescent protein (EYFP). Hematopoietic chimerism composed of both EGFP+ and EYFP+ cells was stably maintained up to 6 months after transplantation with purified CD34+ cells; the ratio of EGFP+ to EYFP+ cells in peripheral blood and bone marrow posttransplantation was equivalent to the ratio of these cells at transplantation. However, when mononuclear cells from two UCB units were cotransplanted with CD34+ cells, engraftment was highly competitive, with cells from only one or the other of the two UCB units surviving. Further subfractionations of mononuclear cells indicate that the skewed chimerism that is often observed in clinical multiunit cord blood transplantation may be mediated by the cooperation of both CD4+ and CD8+ T cells. The assay established here will be a useful tool for analyzing hematopoietic reconstitution in clinical multiunit cord blood transplantation. 相似文献
5.
6.
Possible pro‐inflammatory role of heparin‐binding epidermal growth factor‐like growth factor in the active phase of systemic sclerosis 下载免费PDF全文
Megumi Hirabayashi Yoshihide Asano Takashi Yamashita Shunsuke Miura Kouki Nakamura Takashi Taniguchi Ryosuke Saigusa Takehiro Takahashi Yohei Ichimura Takuya Miyagawa Ayumi Yoshizaki Tomomitsu Miyagaki Makoto Sugaya Shinichi Sato 《The Journal of dermatology》2018,45(2):182-188
Heparin‐binding epidermal growth factor (EGF)‐like growth factor (HB‐EGF) is a member of the EGF family growth factors, which affects multiple aspects of the wound healing process such as epithelialization, wound contraction and angiogenesis. In our study, we measured the serum HB‐EGF levels of 51 systemic sclerosis (SSc) patients, which showed a significant increase compared with those of 20 normal subjects. Further analysis revealed a positive correlation between the HB‐EGF level and pulmonary ground‐glass score but no correlation between the former and pulmonary fibrosis score. Other findings include: a significant increase of serum sialylated carbohydrate antigen KL‐6 levels and significant shortness of disease duration in the diffuse cutaneous SSc patients with elevated HB‐EGF levels; and significantly higher HB‐EGF levels in the presence of Raynaud's phenomenon, in that of telangiectasia, and in the absence of contracture of phalanges in all SSc patients. We then evaluated HB‐EGF mRNA levels of fibroblasts harvested from skin samples of the SSc patients and those of foreskin‐derived fibroblasts treated with transforming growth factor‐β, both of which were significantly higher than each control. In conclusion, we speculate that HB‐EGF plays a pro‐inflammatory role in the active skin and lung lesions of SSc. 相似文献
7.
Tomomitsu Tahara Tomoyuki Shibata Hiromi Yamashita Ichiro Hirata Tomiyasu Arisawa 《Digestive diseases and sciences》2011,56(1):103-108
Background
There is evidence that changes in MDR1 function and/or expression contribute to the pathogenesis of inflammatory disorders of the gastrointestinal tract. 相似文献8.
Kawamoto R Doi T Yamada A Okayama M Tsuruoka K Satho M Kajii E 《Nihon Ronen Igakkai zasshi. Japanese journal of geriatrics》1999,36(12):861-867
In order to maintain and improve mental health of elderly people living in the community, a cross sectional survey was conducted to elucidate their happiness and background factors. The subjects were elderly persons living in the community who were able to fill in the questionnaire themselves. The study employed the self-recording questionnaire forms used in Kahoku Longitudinal Aging Study by Matsubayashi et al. Happiness was assessed using a visual analogue scale. Out of 2,379 elderly persons who were able to fill in the questionnaire by themselves in 2,361 (99.2%) returned the questionnaire sheets. After removing inadequate responses, analysis was possible for 1,873 (78.7%) (860 men (average age 72.7 years) and 1,013 women (average age 72.8 years). Among those with greater happiness, the ratio of those living with others (p = 0.0051) was high as well as those with spouses (p = 0.0240), without a history of hypertension (p = 0.0096) and apoplexy (p = 0.0039), not receiving medication regularly (p = 0.0039), with regular habit of walking (p < 0.001), or with work (p < 0.001). As for the relationship between happiness and various scores, the higher the happiness scale became, the scores for ADL, information-related function, functional and emotional support network, healthy condition, appetite condition, sleep condition, memory condition, family relationships, friendship, economic condition became significantly higher (p < 0.001, respectively). On multiple regression analysis using the background factors for happiness as explanatory variables, factors such as functional support network (p < 0.001), emotional support network (p = 0.0254), healthy condition (p < 0.001), good memory condition (p = 0.0027), friendship (p < 0.001), good economic condition (p < 0.001) were significant independent contributing factors. As for the relation between SDS and happiness, the more serious the SDS score (higher score) became, the scores for the feeling of happiness became significantly smaller (p < 0.001). For amelioration of the happiness of elderly persons living in the community, attempts should be made to improve the background factors clarified by the present study by efficiently utilizing health, medical and welfare services. 相似文献
9.
Kawada H Takizawa S Takanashi T Morita Y Fujita J Fukuda K Takagi S Okano H Ando K Hotta T 《Circulation》2006,113(5):701-710
10.
Ando K Yahata T Sato T Miyatake H Matsuzawa H Oki M Miyoshi H Tsuji T Kato S Hotta T 《Blood》2006,107(8):3371-3377
To characterize human hematopoietic stem cells (HSCs), xenotransplantation techniques such as the severe combined immunodeficiency (SCID) mouse repopulating cell (SRC) assay have proven the most reliable methods thus far. While SRC quantification by limiting dilution analysis (LDA) is the gold standard for measuring in vitro expansion of human HSCs, LDA is a statistical method and does not directly establish that a single HSC has self-renewed in vitro. This would require a direct clonal method and has not been done. By using lentiviral gene marking and direct intra-bone marrow injection of cultured CD34+ CB cells, we demonstrate here the first direct evidence for self-renewal of individual SRC clones in vitro. Of 74 clones analyzed, 20 clones (27%) divided and repopulated in more than 2 mice after serum-free and stroma-dependent culture. Some of the clones were secondary transplantable. This indicates symmetric self-renewal divisions in vitro. On the other hand, 54 clones (73%) present in only 1 mouse may result from asymmetric divisions in vitro. Our data demonstrate that current ex vivo expansion conditions result in reliable stem cell expansion and the clonal tracking we have employed is the only reliable method that can be used in the development of clinically appropriate expansion methods. 相似文献