全文获取类型
收费全文 | 2904篇 |
免费 | 310篇 |
国内免费 | 33篇 |
专业分类
耳鼻咽喉 | 24篇 |
儿科学 | 90篇 |
妇产科学 | 56篇 |
基础医学 | 351篇 |
口腔科学 | 167篇 |
临床医学 | 440篇 |
内科学 | 502篇 |
皮肤病学 | 26篇 |
神经病学 | 174篇 |
特种医学 | 123篇 |
外国民族医学 | 1篇 |
外科学 | 284篇 |
综合类 | 76篇 |
预防医学 | 381篇 |
眼科学 | 125篇 |
药学 | 207篇 |
中国医学 | 4篇 |
肿瘤学 | 216篇 |
出版年
2019年 | 30篇 |
2018年 | 43篇 |
2016年 | 25篇 |
2015年 | 25篇 |
2014年 | 65篇 |
2013年 | 88篇 |
2012年 | 114篇 |
2011年 | 98篇 |
2010年 | 64篇 |
2009年 | 62篇 |
2008年 | 93篇 |
2007年 | 126篇 |
2006年 | 116篇 |
2005年 | 114篇 |
2004年 | 84篇 |
2003年 | 94篇 |
2002年 | 99篇 |
2001年 | 102篇 |
2000年 | 84篇 |
1999年 | 91篇 |
1998年 | 42篇 |
1997年 | 32篇 |
1996年 | 36篇 |
1995年 | 45篇 |
1994年 | 43篇 |
1993年 | 33篇 |
1992年 | 75篇 |
1991年 | 70篇 |
1990年 | 74篇 |
1989年 | 72篇 |
1988年 | 90篇 |
1987年 | 90篇 |
1986年 | 62篇 |
1985年 | 77篇 |
1984年 | 57篇 |
1983年 | 49篇 |
1982年 | 28篇 |
1981年 | 31篇 |
1979年 | 38篇 |
1978年 | 27篇 |
1977年 | 41篇 |
1976年 | 26篇 |
1975年 | 32篇 |
1974年 | 37篇 |
1973年 | 33篇 |
1972年 | 33篇 |
1971年 | 26篇 |
1970年 | 26篇 |
1969年 | 23篇 |
1967年 | 29篇 |
排序方式: 共有3247条查询结果,搜索用时 31 毫秒
61.
Janice M. Morse 《Health care for women international》2013,34(6):548-558
While much has been written about the theoretical aspects of mentoring, the actual strategies, processes, and scope of mentoring are poorly described. Much of the literature is based on a formal model of “orchestrated” mentoring, rather that the spontaneous and very effective mentoring style of academic leaders. Phyllis Noerager Stern, a mentor par excellence, describes the scope and type of established mentoring relationships. These discussions show that our present conceptualization of mentoring should be expanded to include three types of relationships: direct (traditional) mentoring, collegial mentoring, and indirect mentoring. These mentoring relationships may extend internationally and have made a profound impact on a large number of students and emerging academics. They are capable of changing over time from one type to another. In this interview, Phyllis Stern describes the positives and the negatives, and the processes, pitfalls, and outcomes of these various mentoring relationships. 相似文献
62.
Dr. Donald R. Morse D.D.S. M.A. Dr. George R. Schacterle P.M.D. Dr. M. Lawrence Furst Ph.D. M.P.H. Dr. Jordon Goldberg Dr. Brian Greenspan Dr. David Swiecinski 《Behavioral medicine (Washington, D.C.)》2013,39(4):31-39
Abstract Dentally-induced stress and relaxation-induced anxiety reduction have been correlated with salivary changes in dental patients in two recent studies. In two subsequent studies, test anxiety-induced stress and relaxation-induced anxiety reduction were correlated with salivary changes in dental students. In another study using the resazurin dye indicator, increased salivary bacterial levels were correlated with an increased dental caries incidence. As a result of these findings, it was decided to reinvestigate the effects of stress and relaxation on salivary changes and in addition to examine the effects of those conditions on salivary bacteria. The hypotheses under consideration were: (1) Salivary changes from stress to relaxation will be from opaque to translucent and from high to low protein levels; and (2) salivary bacteria will increase under the condition of stress and decrease under the condition of relaxation. The subjects were twelve dental students. Stress and relaxation were evaluated before and after meditation by verbal reports and examination of saliva for opacity, translucency, protein and bacteria (resazurin dye method). There were significant anxiety-reduction changes by the end of the meditation sessions (p < 0.001) as measured by increased salivary translucency, decreased salivary protein and reduced subjective evaluation of stress. Using the resazurin dye method, bacterial levels showed a significant decrease by the end of the meditation sessions (p < 0.001). The results support hypothesis 1 and reaffirm previous findings in regard to the effectiveness of: (1) salivary changes as measures of stress and relaxation; and (2) meditation to induce deep relaxation. The finding of high bacteria levels under stress and lower bacterial levels under relaxation supports hypothesis 2 and indicates that stress may contribute to dental caries and relaxation may have an anti-caries effect. 相似文献
63.
This is a systematic review of existing data on dietary selenium (Se) intake and status for various population groups in Europe (including the United Kingdom (UK)) and the Middle East. It includes English language systematic reviews, meta-analyses, randomised controlled trials, cohort studies, cross-sectional and case-control studies obtained through PUBMED searches from January, 2002, to November, 2014, for European data and from 1990 to November 2014, for Middle Eastern data. Reports were selected if they included data on Se intake and status. The search identified 19 European/UK studies and 15 investigations in the Middle East that reported Se intake and Se concentration in water and/or food and 48 European/UK studies and 44 investigations in the Middle East reporting Se status. Suboptimal Se status was reported to be widespread throughout Europe, the UK and the Middle East, and these results agreed with previous reports highlighting the problem. Eastern European countries had lower Se intake than Western European countries. Middle Eastern studies provided varying results, possibly due to varying food habits and imports in different regions and within differing socioeconomic groups. In conclusion, Se intake and status is suboptimal in European and Middle Eastern countries, with less consistency in the Middle East. 相似文献
64.
Maximilian Ackermann Brent A. Morse Vera Delventhal Irvith M. Carvajal Moritz A. Konerding 《Angiogenesis》2012,15(4):685-695
Increasing experimental evidence suggests that IGF-1 may modulate tumor angiogenesis via activation of the expression of VEGF in Ewing sarcomas and rhabdomyosarcomas. This study investigates the effects of the PEGylated Adnectins? CT-322, a VEGFR2-inhibitor and AT580Peg40, an IGF-1R inhibitor, as monotherapy and in combination in a murine A673 xenograft tumor model. The combination of Adnectins CT-322 and AT580Peg40 revealed a 83?% reduction in tumor growth, a nearly 5 times lower vessel density, less necrotic areas and less appearance of intussusceptive angiogenesis. Monotherapy with IGF-1R or CT-322 revealed equally a significant inhibition of tumor and vessel growth. Combinatory inhibition of IGF-1R and VEGFR2 shows a downregulation of IGF-binding protein 2 and a compensatory upregulation of VEGF levels. Immunohistological analysis showed remodeling vascular effects of CT-322-treatment or combination therapy. The vascular architecture in Adnectin-treated tumors was characterized by a strong normalization of vasculature. 3D-evaluation in microvascular corrosion casts showed significantly higher intervascular and interbranching distances in Adnectin-treated tumors. CT-322-treatment and combinatory inhibition reveal a significant reduction of intussusceptive angiogenesis. These pronounced effects on tumor vasculature suggest potential therapeutic benefit of combinatorial IGF1- and VEGF- pathways inhibition in Ewing’s sarcoma. 相似文献
65.
It doesn't take a lot of skill to play racquetball and benefit from the excellent exercise it provides. Most of the injuries can be prevented if safety precautions are observed. 相似文献
66.
67.
W. Dean Klinkenberg Robert J. Calsyn Gary A. Morse Suzanne McCudden Tracey L. Richmond Gary K. Burger 《AIDS and behavior》2002,6(4):295-307
In this paper we present data from a study of the consistency of recall of several sexual and drug-using behaviors gathered from face-to-face interviews with homeless persons who have dual diagnosis (severe mental illness plus a substance use disorder). Factors associated with inconsistent reporting are also examined. One hundred and thirty-three individuals participating in a longitudinal study of HIV risk behaviors were recruited for a retrospective recall study. Participants were completing monthly interviews that included assessments of sexual behaviors and drug use. Participants completed an additional interview using the same instruments and were randomly assigned to a 3- or 6-month recall condition; the data from the additional interview were correlated with the regular, monthly interviews. Results indicated that reports of sexual and substance-using behaviors were generally reported consistently for both 3- and 6-month recall periods; however, coefficients for the 3-month interval were generally better than those for the 6-month interval. One exception was that protected intercourse was generally not reported consistently. Inconsistent reporting of sexual and drug-using behaviors was associated with the severity of substance abuse; inconsistent reporting of sexual behaviors was also associated with African-American race. Our data suggest that a 3-month recall interval is generally superior to a 6-month interval for persons with severe mental illness. 相似文献
68.
69.
CTCF functions as a critical regulator of cell-cycle arrest and death after ligation of the B cell receptor on immature B cells
下载免费PDF全文
![点击此处可从《Proceedings of the National Academy of Sciences of the United States of America》网站下载免费的PDF全文](/ch/ext_images/free.gif)
70.
A subset of human monocyte-derived dendritic cells expresses high levels of interleukin-12 in response to combined CD40 ligand and interferon-gamma treatment 总被引:10,自引:1,他引:10
Dendritic cells (DCs) may arise from multiple lineages and progress through a series of intermediate stages until fully mature, at which time they are capable of optimal antigen presentation and T-cell activation. High cell surface expression of CD83 is presumed to correlate with full maturation of DCs, and a number of agents have been shown to increase CD83 expression on DCs. We hypothesized that interleukin 12 (IL-12) expression would be a more accurate marker of functionally mature DCs capable of activating antigen-specific T cells. We used combinations of signaling through CD40, using CD40 ligand trimer (CD40L), and interferon gamma to demonstrate that CD83 expression is necessary but not sufficient for optimal production of IL-12 by DCs. Phenotypically mature DCs could be induced to produce high levels of IL-12 p70 only when provided 2 simultaneous stimulatory signals. By intracellular cytokine detection, we determined that only a subset of cells that express high levels of CD80 and CD83 generate large amounts of IL-12. DCs matured with both signals are superior to DCs stimulated with the individual agents in activating antigen-specific T cell in vitro. These findings have important implications regarding the identification, characterization, and clinical application of functionally mature DCs. 相似文献