首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   2159篇
  免费   124篇
  国内免费   5篇
耳鼻咽喉   25篇
儿科学   97篇
妇产科学   67篇
基础医学   251篇
口腔科学   56篇
临床医学   222篇
内科学   490篇
皮肤病学   33篇
神经病学   105篇
特种医学   451篇
外科学   191篇
综合类   50篇
一般理论   4篇
预防医学   58篇
眼科学   50篇
药学   75篇
  1篇
肿瘤学   62篇
  2021年   15篇
  2019年   16篇
  2018年   17篇
  2017年   19篇
  2016年   20篇
  2015年   17篇
  2014年   40篇
  2013年   50篇
  2012年   44篇
  2011年   40篇
  2010年   58篇
  2009年   66篇
  2008年   43篇
  2007年   66篇
  2006年   62篇
  2005年   54篇
  2004年   47篇
  2003年   50篇
  2002年   35篇
  2001年   35篇
  2000年   42篇
  1999年   38篇
  1998年   87篇
  1997年   94篇
  1996年   88篇
  1995年   71篇
  1994年   51篇
  1993年   66篇
  1992年   33篇
  1991年   46篇
  1990年   54篇
  1989年   61篇
  1988年   70篇
  1987年   61篇
  1986年   69篇
  1985年   84篇
  1984年   41篇
  1983年   44篇
  1982年   42篇
  1981年   35篇
  1980年   45篇
  1979年   16篇
  1978年   27篇
  1977年   30篇
  1976年   32篇
  1975年   29篇
  1973年   15篇
  1971年   13篇
  1970年   16篇
  1969年   14篇
排序方式: 共有2288条查询结果,搜索用时 46 毫秒
61.
Some of the girls who live in Germany and have Muslim parents are threatened by female genital mutilation. This report describes the kinds and medical consequences of female genital mutilation as well as the criminal judgement. Female genital mutilation is considered as dangerous bodily harm, not as grievous bodily harm. Consent does not justify the infringement of rights. The argument that Islam justifies the infringement of rights is irrelevant by law. The human right of bodily intactness has priority over the right of religious freedom. Finally the legal regulations about dealing with personal data are presented. A legal compulsory registration still does not exist.  相似文献   
62.
63.
64.
65.
Objective: To investigate if duration of supplemental breastfeeding is associated with a lower asthma risk and whether adverse childhood experiences (ACEs) early in life influence this relationship in children ages 3 to 5 years. Methods: Data were from the 2011–2012 National Survey of Children's Health, a nationally representative cross-sectional survey. Modified Poisson regression models were used to estimate incident risk ratios (IRR) for lifetime and current asthma in young children aged 3 to 5 years (n = 15,642). We tested for effect measure modification using stratified analyses. Results: Exclusive breastfeeding for at least 6 months or supplemental breastfeeding for children ≥12 months significantly reduced the risk of lifetime asthma prevalence compared to never breastfed children (IRR 0.64; 95% CI: 0.46–0.88, p = 0.007; and IRR 0.68; 95% CI: 0.47–0.99, p = 0.044, respectively), adjusted for covariates. In stratified analyses, breastfeeding reduced the risk of lifetime asthma for children who experienced 1 ACE but not for children who experienced 2 or more ACEs. Conclusion: Exclusive breastfeeding for at least 6 months, with and without supplementation, appears to prevent asthma or delay its onset. The protective effect of breastfeeding was attenuated among children who experienced more than 2 ACEs. The known harmful effects that ACEs have on children's health may outweigh the benefits of breastfeeding in reducing the risk of a child developing asthma. Understanding how specific time periods in a child's life may be most affected by exposure to early life adversities, along with the protective effect of breastfeeding against asthma, are important areas of further study.  相似文献   
66.
67.
Objectives: To investigate correlations between power seat functions (PSFs) usage and wheelchair discomfort.

Design: Quasi-experimental design: Time series design.

Setting: In-home trial in participants’ home/community.

Participants: Thirteen power wheelchair users who independently used power wheelchairs equipped with PSFs as their primary means of mobility.

Main Outcome Measures: PSF usage variables include the frequency of performing repositioning and using PSFs (tilt, recline, legrests and seat elevation), wheelchair occupancy, and driving distance. The Tool for Assessing Wheelchair disComfort (TAWC) were used to evaluate general discomfort and discomfort intensity.

Results: Spearman correlation coefficient showed that the frequency of using tilt, recline, and legrest is significantly correlated with discomfort intensity. Multiple regression analysis with backward stepwise indicated that these functions can explain 43.8% of the variance (R2?=?.438, F(3,33)?=?8.588, P?Conclusions: For people who used power wheelchairs equipped with PSFs, correlation analysis and regression modeling provided evidence from the quantitative data that increasing the frequency of using PSFs may decrease wheelchair discomfort. Future studies should include interventions to encourage people to use their PSFs appropriately.  相似文献   
68.
69.
OBJECTIVES: The purpose of this study was to examine the effect of exercise-induced ischemia on levels of B-type natriuretic peptide (BNP) and its inactive N-terminal fragment (NT-pro-BNP)and to determine whether measurement of these peptides can improve the diagnostic accuracy of exercise testing. BACKGROUND: The ability of exercise testing to detect coronary artery disease (CAD) is limited by modest sensitivity and specificity. B-type natriuretic peptides (NT-pro-BNP and BNP) are released by ventricular myocytes in response to wall stress. We hypothesized that exercise-induced ischemia results in increased wall stress and triggers release of NT-pro-BNP and BNP. METHODS: A total of 74 patients with known CAD, normal left ventricular function, and normal resting levels of NT-pro-BNP and BNP who were referred for exercise testing with radionuclide imaging, and 21 healthy volunteers, were enrolled. Blood was drawn before and after maximal exercise and analyzed for NT-pro-BNP and BNP. RESULTS: Of the patients with CAD, 40 had ischemia on perfusion images and 34 did not. Median post-exercise increases in NT-pro-BNP and BNP (DeltaNT-pro-BNP and DeltaBNP) were approximately four-fold higher in the ischemic group than in the nonischemic group (DeltaNT-pro-BNP 14.5 vs. 4 pg/ml, p < 0.0001; DeltaBNP 36.5 vs. 7.5 pg/ml, p < 0.0001). In volunteers, median DeltaNT-pro-BNP was almost identical to that of the nonischemic patient group. At equal specificity to the electrocardiogram (ECG) (58.8%), the sensitivities of DeltaNT-pro-BNP and DeltaBNP for detecting ischemia were 90% and 80%, respectively; in contrast, the sensitivity of the exercise ECG was 37.5%. CONCLUSIONS: Measurement of exercise-induced increases in BNPs more than doubles the sensitivity of the exercise test for detecting ischemia with no loss of specificity.  相似文献   
70.
Seventy-five patients, 13 to 49 years of age, with acute nonlymphoblastic leukemia in first remission were treated with cyclophosphamide, fractionated total body irradiation, and marrow transplantation from an HLA-identical sibling and randomized to receive either cyclosporine (CSP) (n = 36) or methotrexate (MTX) (n = 39) as prophylaxis for graft-v-host disease (GVHD). All patients engrafted, and 22 who were given CSP and 21 who were given MTX, are alive at 20 to 47 (median, 35) months (P = .5). Engraftment as assessed by granulocyte recovery (P less than .0005) and platelet transfusion requirement (P = .01) was faster in patients on CSP. Twelve patients (33%) on CSP and 22 (56%) on MTX developed acute GVHD of grades II through IV (P = .07) and 15 of 30 on CSP and 14 of 32 on MTX that were at risk developed chronic GVHD. The most frequent causes of death were interstitial pneumonitis and marrow relapse of leukemia, which occurred with similar frequency in both groups. Beneficial effects observed in patients on CSP included less severe mucositis and shorter duration of hospitalization; adverse effects included renal function impairment and hypertension. These data confirm that CSP is a useful immunosuppressant in patients undergoing marrow transplantation but fail to show a significant improvement in survival as compared with the standard regimen of MTX.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号