全文获取类型
收费全文 | 3932篇 |
免费 | 534篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 37篇 |
儿科学 | 104篇 |
妇产科学 | 299篇 |
基础医学 | 367篇 |
口腔科学 | 55篇 |
临床医学 | 1136篇 |
内科学 | 634篇 |
皮肤病学 | 76篇 |
神经病学 | 226篇 |
特种医学 | 292篇 |
外科学 | 290篇 |
综合类 | 92篇 |
预防医学 | 375篇 |
眼科学 | 28篇 |
药学 | 197篇 |
中国医学 | 8篇 |
肿瘤学 | 261篇 |
出版年
2023年 | 60篇 |
2021年 | 33篇 |
2020年 | 71篇 |
2019年 | 58篇 |
2018年 | 110篇 |
2017年 | 133篇 |
2016年 | 119篇 |
2015年 | 146篇 |
2014年 | 150篇 |
2013年 | 167篇 |
2012年 | 122篇 |
2011年 | 168篇 |
2010年 | 157篇 |
2009年 | 154篇 |
2008年 | 117篇 |
2007年 | 133篇 |
2006年 | 133篇 |
2005年 | 100篇 |
2004年 | 101篇 |
2003年 | 107篇 |
2002年 | 95篇 |
2001年 | 99篇 |
2000年 | 91篇 |
1999年 | 104篇 |
1998年 | 108篇 |
1997年 | 129篇 |
1996年 | 122篇 |
1995年 | 112篇 |
1994年 | 99篇 |
1993年 | 69篇 |
1992年 | 63篇 |
1991年 | 84篇 |
1990年 | 51篇 |
1989年 | 89篇 |
1988年 | 72篇 |
1987年 | 67篇 |
1986年 | 61篇 |
1985年 | 56篇 |
1984年 | 47篇 |
1983年 | 45篇 |
1982年 | 26篇 |
1981年 | 31篇 |
1980年 | 26篇 |
1979年 | 39篇 |
1978年 | 49篇 |
1977年 | 41篇 |
1976年 | 40篇 |
1975年 | 30篇 |
1973年 | 22篇 |
1969年 | 20篇 |
排序方式: 共有4477条查询结果,搜索用时 9 毫秒
1.
Well‐being,health and fitness of children who use wheelchairs: Feasibility study protocol to develop child‐centred ‘keep‐fit’ exercise interventions 下载免费PDF全文
2.
3.
Transplanting the Highly Sensitized Patient: The Emory Algorithm 总被引:4,自引:0,他引:4
R. A. Bray J. D. L. Nolen C. Larsen T. Pearson K. A. Newell K. Kokko A. Guasch P. Tso J. B. Mendel H. M. Gebel 《American journal of transplantation》2006,6(10):2307-2315
Renal transplant patients sensitized to HLA antigens comprise nearly one-third of the UNOS wait-list and receive 14% of deceased donor (DD) transplants, a rate half that of unsensitized patients. Between 1999 and 2003, we performed 492 adult renal transplants from DD; 120 patients (approximately 25%) had a panel reactive antibody (PRA) of >30%, with nearly half (n = 58) having a PRA of >80%. Our approach is based upon high-resolution solid-phase HLA antibody analysis to identify class I/II antibodies and a 'virtual crossmatch' to predict compatible donor/recipient combinations. Recipients are excluded from the United Network for Organ Sharing match run if donors possess unacceptable antigens. Thus, when sensitized patients appear on the match run, they have a high probability of a negative final crossmatch. Here, we describe our 5-year experience with this approach. Five-year graft survival ranged from 66% to 70% among unsensitized (n = 272), moderately sensitized (PRA < 30%, n = 100) and highly sensitized (>30% PRA; n = 120) patients, equal to the average national graft survival (65.7%). The application of this approach (the Emory Algorithm) provides a logical and systematic approach to improve the access of sensitized patients to DD organs and promote more equitable allocation to a highly disadvantaged group of patients awaiting renal transplantation. 相似文献
4.
D Van Neste† RM Trüeb‡ 《Journal of the European Academy of Dermatology and Venereology》2006,20(5):578-583
BACKGROUND: Computer-assisted image analysis has been proposed for human hair growth studies. METHODS: The performances of Trichoscan, a commercially available automated system combining epiluminiscence microscopy with digital image analysis, developed for office-based hair growth measurements, have been evaluated comparatively on the same skin sites using standardized photographic equipment and calibrated processing for contrast-enhanced phototrichogram (CE-PTG) analysis. This reference method has been validated with scalp biopsies and histological examination of serial sectioning. RESULTS: Besides edge effects, hair fibres escaped the Trichoscan analysis for various reasons including, but not limited to, thickness, pigmentation, closeness and crossing. CONCLUSION: Most of these problems have been identified in the late 1980s and remain largely unsolved by the processing software that was evaluated in 2004. Therefore claims promoting the Trichoscan method for accurate hair measurements in clinical trials on scalp and body hair are not supported by the present investigation. The speed at which the analysis is performed is outweighed by the errors in signal detection. Therefore we suggest that improvements must be clearly documented before Trichoscan is established for quantified diagnostic purposes and detailed hair cycle monitoring during hair trials. 相似文献
5.
6.
An ecologically based examination of barriers to physical activity in students from grade seven through first-year university 总被引:1,自引:0,他引:1
Nancy C. Gyurcsik Ph.D. Kevin S. Spink Ph.D. Steven R. Bray Ph.D. Karen Chad Ph.D. Matt Kwan B.Sc. 《The Journal of adolescent health》2006,38(6):704-711
PurposeThe first purpose was to identify barriers to physical activity that students in grade seven through first-year university experienced. A second purpose was to classify barriers using an ecological framework and to examine the pattern of barrier categories (i.e., intrapersonal, interpersonal, institutional, community, public policy, and physical environmental) and specific barrier types as grade increased. The use of an ecological model addressed limitations in prior research revolving around the identification of salient barriers in a manner that makes the design of effective interventions difficult.MethodsParticipants in grades 7–8 (n = 35), 9–10 (n = 67), 11–12 (n = 80), and the freshmen year of university (n = 109) listed barriers to physical activity on an open-ended measure.ResultsFindings revealed a trend for the average number of barriers reported per student to increase as grade in school increased. First-year university students reported significantly more barriers than all other grade groupings. The frequency of barriers reported within the ecological categories was dependent on the specific grade groupings. Further, within each ecological category, distinct barriers were reported across the different grade groupings.ConclusionsFindings highlight the utility of using an ecological model to categorize barriers, rather than simply classifying barriers as internal or external to an individual, as done in prior research. Understanding the pattern of ecologically based barrier categories and specific types of barriers will help to inform the content of future research and interventions designed to alleviate salient barriers to physical activity. 相似文献
7.
R Litzenberger K M Morgan S F Marden K N Jacobs-Irvine S A Bray 《The Journal of cardiovascular nursing》1991,5(2):58-66
This case study illustrates the chronic nature of hyperlipidemia type IIa and the important contribution of the nurse in helping the client adjust life style, manage complex health regimes, and cope with the uncertainty of disease progression and its associated risks. 相似文献
8.
Deborah Bray Preston Anthony R D'Augelli Cathy D Kassab Richard E Cain Frederick W Schulze Michael T Starks 《AIDS education and prevention》2004,16(4):291-303
Research investigating predictors of risky sexual behavior of rural MSM is sparse, even though the prevalence of HIV in rural areas has increased. This study explored two sets of predictors of 93 rural MSM's levels of risky sexual behavior: mental health variables and stigma emanating from men's family members, health care professionals, and people in the rural communities in which they live. Over 47% of the men were found to be at modified high to high risk. Logistic regression using a continuation logit model was used to test the relationship of the predictor variables and the four levels of risk. Findings indicate that self-esteem was predictive of the highest sexual risk behavior but not lower levels of risk. Stigma was predictive of modified high sexual risk when compared to low and no risk categories. No variables differentiated men at low risk from men at no risk. 相似文献
9.
V Schleyer† S Radakovic-Fijan‡ S Karrer† T Zwingers§ A Tanew‡ M Landthaler† RM Szeimies† 《Journal of the European Academy of Dermatology and Venereology》2006,20(7):823-828
BACKGROUND: Based on good results in the treatment of superficial skin tumours, since the early 1990s topical photodynamic therapy with aminolaevulinic acid (ALA PDT) has been used for disseminated, inflammatory dermatoses including psoriasis. However, there is still a lack of well-documented trials. OBJECTIVE: A prospective randomized, double-blind phase I/II intrapatient comparison study was conducted in 12 patients to investigate whether topical ALA PDT is an effective treatment for chronic plaque-type psoriasis. METHODS: In each patient three psoriatic plaques were randomly treated with a light dose of 20 J/cm(2) and 0.1%, 1% and 5% ALA, respectively. Treatment was conducted twice a week until complete clearance or for a maximum of 12 irradiations. Therapeutic efficacy was assessed by weekly determination of the psoriasis severity index (PSI). RESULTS: The mean percentage improvement was 37.5%, 45.6% and 51.2% in the 0.1%, 1% and 5% ALA-treated groups, respectively. Irradiation had to be interrupted several times because of severe burning and pain sensation. CONCLUSION: Topical ALA PDT did not prove to be an appropriate treatment option for plaque-type psoriasis due to disappointing clinical efficacy, the time-consuming treatment procedure and its unfavourable adverse event profile. 相似文献
10.