全文获取类型
收费全文 | 2794篇 |
免费 | 197篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 161篇 |
妇产科学 | 58篇 |
基础医学 | 314篇 |
口腔科学 | 53篇 |
临床医学 | 328篇 |
内科学 | 590篇 |
皮肤病学 | 27篇 |
神经病学 | 59篇 |
特种医学 | 737篇 |
外科学 | 240篇 |
综合类 | 70篇 |
一般理论 | 2篇 |
预防医学 | 167篇 |
眼科学 | 25篇 |
药学 | 87篇 |
中国医学 | 3篇 |
肿瘤学 | 89篇 |
出版年
2021年 | 24篇 |
2020年 | 21篇 |
2019年 | 20篇 |
2018年 | 30篇 |
2017年 | 19篇 |
2016年 | 36篇 |
2015年 | 41篇 |
2014年 | 49篇 |
2013年 | 110篇 |
2012年 | 93篇 |
2011年 | 91篇 |
2010年 | 111篇 |
2009年 | 113篇 |
2008年 | 85篇 |
2007年 | 92篇 |
2006年 | 83篇 |
2005年 | 72篇 |
2004年 | 65篇 |
2003年 | 51篇 |
2002年 | 65篇 |
2001年 | 41篇 |
2000年 | 53篇 |
1999年 | 51篇 |
1998年 | 144篇 |
1997年 | 129篇 |
1996年 | 137篇 |
1995年 | 104篇 |
1994年 | 82篇 |
1993年 | 88篇 |
1992年 | 44篇 |
1991年 | 41篇 |
1990年 | 34篇 |
1989年 | 77篇 |
1988年 | 65篇 |
1987年 | 63篇 |
1986年 | 62篇 |
1985年 | 62篇 |
1984年 | 35篇 |
1983年 | 43篇 |
1982年 | 44篇 |
1981年 | 24篇 |
1980年 | 43篇 |
1979年 | 23篇 |
1978年 | 21篇 |
1977年 | 26篇 |
1976年 | 31篇 |
1975年 | 30篇 |
1973年 | 13篇 |
1972年 | 12篇 |
1971年 | 15篇 |
排序方式: 共有3013条查询结果,搜索用时 421 毫秒
1.
2.
JA HYEON KU CHEOL KWAK SEUNG-JUNE OH EUNSIK LEE SANG EUN LEE JAE-SEUNG PAICK 《International journal of urology》2004,11(7):489-493
BACKGROUND: Our aims in the present study were to estimate the influences of pain and urinary symptoms on quality of life, and to determine which of these two variables has the most predictive power with respect to quality of life in young men with chronic prostatitis-like symptoms. METHODS: Chronic prostatitis-like symptoms were measured by the National Institutes of Health-Chronic Prostatitis Symptom Index. Of the 28,841 men aged 20 years who lived in the study community, 18,495 men (a response rate 64.1%) agreed to participate in the study. A total of 1057 men who complained of symptoms indicative of chronic prostatitis were included in the study. The influences of pain and urinary symptoms on quality of life were determined using logistic regression analysis. The receiver operating characteristic (ROC) curve was used to estimate the predictive ability of each of these variables with respect to quality of life. RESULTS: Results from multivariate analysis showed that both pain and urinary symptoms were associated with an increased likelihood of impaired quality of life, although pain contributed more to a reduced quality of life than urinary symptoms. Relative to men who experienced mild pain, men who experienced moderate pain had a 3.9-fold risk of poor quality of life (odds ratio [OR], 3.87; 95% confidence interval [CI], 2.86-5.23; P < 0.001) and those who experienced severe pain had a 15.7-fold risk of reduced quality of life (OR, 15.68; 95% CI, 6.59-37.35; P < 0.001). Moderate urinary symptoms were associated with a 1.4-fold risk of bother (OR, 1.41; 95% CI, 1.01-1.99; P < 0.001) and severe urinary symptoms were associated with 2.4-fold risk (OR, 2.39; 95% CI, 1.37-4.12; P < 0.001), relative to mild urinary symptoms. Comparison of the effects of pain and urinary symptoms showed that pain severity had the most predictive power for bother, quality of life, and quality-of-life impact. The areas under the ROC curves for bother, quality of life, and quality-of-life impact were 71.3%, 69.3% and 72.5%, respectively. CONCLUSION: Urinary symptoms and pain might be associated with an increased likelihood of impaired quality of life in young men with chronic prostatitis-like symptoms. In addition, our findings suggest that pain severity is the most influential variable for determining quality of life in this population. 相似文献
3.
4.
5.
6.
7.
Abstract: Background : In response to rising cesarean rates, it is reasonable for health care organizations to look to a managed care model as a means of controlling further rate increases. However, little conclusive evidence exists to support this solution. We undertook a study of the Department of Defense health care beneficiary population to assess the impact of enrollment in TRICARE Prime, the Department's managed care health plan, on cesarean delivery rates. Methods : Pooled hospital discharge records from 1999–2002 for live, singleton births were analyzed to calculate primary and repeat cesarean rates for TRICARE Prime and non‐Prime beneficiaries in the military and civilian hospitals that comprise the Department of Defense health care network. Stepwise logistic regression was used to calculate adjusted odds ratios for clinical indicators for each combination of health plan and hospital setting using theχ2difference(p < 0.05)to eliminate nonsignificant variables from the model. Total primary and repeat cesarean rates were compared with primary and repeat cesarean rates for women with no reported clinical complications to account for differences in case mix across subgroups. Statistical significance of the differences calculated for subgroups was assessed usingχ2. Results : Primary cesarean rates were significantly lower for TRICARE Prime enrollees relative to non‐Prime beneficiaries for all race subgroups and three of five age subgroups in military hospitals and four of five age subgroups in civilian hospitals. No significant differences in repeat cesarean rates were observed between Prime and non‐Prime beneficiaries within any race or age subgroup. Breech presentation followed by dystocia, fetal distress, and other complications were significant predictors for primary cesarean. Previous cesarean delivery was the leading predictor for repeat cesarean delivery. Primary and repeat cesarean rates observed for military hospitals were consistently lower than rates observed for civilian hospitals within each health plan type and age group. Conclusions : Enrollment in the managed care health plan was significantly associated with lower risk of primary cesarean delivery relative to membership in other health plans offered to Department of Defense health care beneficiaries. Repeat cesarean rates in this population varied independently of health plan type. Primary cesarean delivery was generally associated with clinical complications, whereas previous cesarean delivery was the strongest indictor for a repeat cesarean delivery. A clear explanation of reduced cesarean rates for Prime enrollees remains elusive, but it is likely that factors beyond individual practitioner decision‐making were at work. 相似文献
8.
Andr Mas Hassan Jaaba Franois Schu Anna M. Belu Camille M. Kassis Richard W. Linton Joseph M. Desimone 《Macromolecular chemistry and physics.》1997,198(11):3737-3752
Homogeneous and stable layers were deposited through allylamine plasma polymerization (75 W, 100 Pa, 15 min) onto poly[(3-hydroxybutyric acid)-co-(3-hydroxyvaleric acid)] (91 : 9 wt.-%) (P(HB-co-9%HV)) film surfaces, XPS analysis using take-off angles of 20° and 70° and performed 10 days and 20 days after plasma treatment gives information on the composition (in atom%) of the modified surface: C, 62.74; N, 19.60; O, 17.65. The unexpected oxygen percentage is weaker if argon plasma pretreatment (25 W, 40 Pa, 5 min) is applied. Then, a succinct mechanism is proposed. The study of changes in element ratios and binding energy values shows that the majority of incorporated functional groups seem to be amide and imine groups. 相似文献
9.
10.