全文获取类型
收费全文 | 164995篇 |
免费 | 33647篇 |
国内免费 | 2438篇 |
专业分类
耳鼻咽喉 | 5259篇 |
儿科学 | 5930篇 |
妇产科学 | 2804篇 |
基础医学 | 5793篇 |
口腔科学 | 1689篇 |
临床医学 | 28515篇 |
内科学 | 49842篇 |
皮肤病学 | 7724篇 |
神经病学 | 16683篇 |
特种医学 | 6681篇 |
外科学 | 42530篇 |
综合类 | 310篇 |
现状与发展 | 72篇 |
一般理论 | 23篇 |
预防医学 | 8788篇 |
眼科学 | 3612篇 |
药学 | 1941篇 |
中国医学 | 38篇 |
肿瘤学 | 12846篇 |
出版年
2024年 | 527篇 |
2023年 | 4923篇 |
2022年 | 1428篇 |
2021年 | 3802篇 |
2020年 | 6443篇 |
2019年 | 2787篇 |
2018年 | 7983篇 |
2017年 | 7808篇 |
2016年 | 8930篇 |
2015年 | 8952篇 |
2014年 | 16180篇 |
2013年 | 16571篇 |
2012年 | 6894篇 |
2011年 | 6885篇 |
2010年 | 10971篇 |
2009年 | 14815篇 |
2008年 | 6852篇 |
2007年 | 5026篇 |
2006年 | 7383篇 |
2005年 | 4653篇 |
2004年 | 3859篇 |
2003年 | 2717篇 |
2002年 | 2689篇 |
2001年 | 3877篇 |
2000年 | 3036篇 |
1999年 | 3264篇 |
1998年 | 3746篇 |
1997年 | 3550篇 |
1996年 | 3414篇 |
1995年 | 3256篇 |
1994年 | 1984篇 |
1993年 | 1597篇 |
1992年 | 1398篇 |
1991年 | 1424篇 |
1990年 | 1069篇 |
1989年 | 1191篇 |
1988年 | 1027篇 |
1987年 | 871篇 |
1986年 | 893篇 |
1985年 | 723篇 |
1984年 | 558篇 |
1983年 | 534篇 |
1982年 | 535篇 |
1981年 | 417篇 |
1980年 | 375篇 |
1979年 | 315篇 |
1978年 | 334篇 |
1977年 | 405篇 |
1975年 | 279篇 |
1972年 | 283篇 |
排序方式: 共有10000条查询结果,搜索用时 125 毫秒
51.
52.
53.
Emma J. Walker Noni E. MacDonald Nehal Islam Nicole Le Saux Karina A. Top Deshayne B. Fell 《Vaccine》2019,37(13):1725-1735
Objective
To systematically review literature on uptake and timeliness of diphtheria-tetanus-pertussis, measles-mumps-rubella, and/or polio-containing vaccines in infants who were born preterm, with a low birth weight, and/or with chronic health conditions that were diagnosed within the first 6?months of life.Methods
Using a standardized search strategy developed by a medical librarian, records were extracted from MEDLINE, Embase, Database of Abstracts of Reviews of Effects, and CINAHL up to May 8, 2018.Results
Out of the 1997 records that were screened, we identified 21 studies that met inclusion criteria. Eleven studies assessed vaccine coverage and/or timeliness in preterm infants, 6 in low birth weight infants, and 7 in children with chronic health conditions. Estimates of coverage in these populations were highly variable, ranging from 40% to 100% across the vaccines and population groups.Conclusions
There is a lack of studies reporting coverage and timeliness of routine immunizations in special populations of children.Policy implications
Our review suggests a need for improved surveillance of immunization status in special populations of infants, as well as a need for standardization of reporting practices. 相似文献54.
55.
Alexander Real Chierika Ukogu Divya Krishnamoorthy Nicole Zubizarreta Samuel K. Cho Andrew C. Hecht James C. Iatridis 《The spine journal》2019,19(2):225-231
Background Context
Low back pain (LBP) is a common complaint in clinical practice of multifactorial origin. Although obesity has been thought to contribute to LBP primarily by altering the distribution of mechanical loads on the spine, the additional contribution of obesity-related conditions such as diabetes mellitus (DM) to LBP has not been thoroughly examined.Purpose
To determine if there is a relationship between DM and LBP that is independent of body mass index (BMI) in a large cohort of adult survey participants.Study Design
Retrospective analysis of prospectively collected National Health and Nutrition Examination Survey (NHANES) data to characterize associations between LBP, DM, and BMI in adults subdivided into 6 subpopulations: normal weight (BMI 18.5–25), overweight (BMI 25–30), and obese (BMI >30) diabetics and nondiabetics. Diabetes was defined with glycohemoglobin A1c (HbA1c) ≥6.5%.Patient Sample
11,756 participants from NHANES cohort.Outcome Measures
Percentage of LBP reported.Methods
LBP reported in the 1999-2004 miscellaneous pain NHANES questionnaire was the dependent variable examined. Covariates included HbA1c, BMI, age, and family income ratio to poverty as continuous variables as well as race, gender, and smoking as binary variables. Individuals were further subdivided by weight class and diabetes status. Regression and graphical analyses were performed on the study population as a whole and also on subpopulations.Results
Increasing HbA1c did not increase the odds of reporting LBP in the full cohort. However, multivariate logistic regression of the 6 subpopulations revealed that the odds of LBP significantly increased with increasing HbA1c levels in normal weight diabetics. No other subpopulations reported significant relationships between LBP and HbA1c. LBP was also significantly associated with BMI for normal weight diabetics and also for obese subjects regardless of their DM status.Conclusions
LBP is significantly related to DM status, but this relationship is complex and may interact with BMI. These results support the concept that LBP may be improved in normal weight diabetic subjects with improved glycemic control and weight loss, and that all obese LBP subjects may benefit from improved weight loss alone. 相似文献56.
57.
Marie V. Plaisime PhD MPH Marie Jipguep-Akhtar PhD Joseph J. Locascio PhD Harolyn M. E. Belcher MD MHS Rachel R. Hardeman PhD MPH Katherine Picho-Kiroga PhD Sylvia P. Perry PhD Sean M. Phelan PhD MPH Michelle van Ryn PhD LMFT MPH John F. Dovidio PhD 《Health services research》2023,58(Z2):229-237
Objective
To examine the experience of interracial anxiety among health professionals and how it may affect the quality of their interactions with patients from racially marginalized populations. We explored the influence of prior interracial exposure—specifically through childhood neighborhoods, college student bodies, and friend groups—on interracial anxiety among medical students and residents. We also examined whether levels of interracial anxiety change from medical school through residency.Data Source
Web-based longitudinal survey data from the Medical Student Cognitive Habits and Growth Evaluation Study.Study Design
We used a retrospective longitudinal design with four observations for each trainee. The study population consisted of non-Black US medical trainees surveyed in their 1st and 4th years of medical school and 2nd and 3rd years of residency. Mixed effects longitudinal models were used to assess predictors of interracial anxiety and assess changes in interracial anxiety scores over time.Principal Findings
In total, 3155 non-Black medical trainees were followed for 7 years. Seventy-eight percent grew up in predominantly White neighborhoods. Living in predominantly White neighborhoods and having less racially diverse friends were associated with higher levels of interracial anxiety among medical trainees. Trainees' interracial anxiety scores did not substantially change over time; interracial anxiety was highest in the 1st year of medical school, lowest in the 4th year, and increased slightly during residency.Conclusions
Neighborhood and friend group composition had independent effects on interracial anxiety, indicating that premedical racial socialization may affect medical trainees' preparedness to interact effectively with diverse patient populations. Additionally, the lack of substantial change in interracial anxiety throughout medical training suggests the importance of providing curricular tools and structure (e.g., instituting interracial cooperative learning activities) to foster the development of healthy interracial relationships. 相似文献58.
59.
60.
Katherine M. Duszynski Nicole L. Pratt John W. Lynch Jesia G. Berry Michael S. Gold 《Vaccine》2019,37(2):280-288