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   520篇
  免费   31篇
  国内免费   6篇
耳鼻咽喉   1篇
儿科学   16篇
妇产科学   15篇
基础医学   39篇
口腔科学   3篇
临床医学   76篇
内科学   161篇
皮肤病学   7篇
神经病学   13篇
特种医学   6篇
外科学   29篇
综合类   21篇
预防医学   56篇
眼科学   16篇
药学   58篇
中国医学   4篇
肿瘤学   36篇
  2023年   6篇
  2022年   1篇
  2021年   8篇
  2020年   17篇
  2019年   1篇
  2018年   6篇
  2017年   7篇
  2016年   6篇
  2015年   18篇
  2014年   6篇
  2013年   12篇
  2012年   38篇
  2011年   39篇
  2010年   13篇
  2009年   15篇
  2008年   37篇
  2007年   36篇
  2006年   33篇
  2005年   32篇
  2004年   56篇
  2003年   62篇
  2002年   44篇
  2001年   35篇
  2000年   5篇
  1999年   4篇
  1998年   2篇
  1997年   4篇
  1996年   1篇
  1995年   1篇
  1994年   1篇
  1993年   1篇
  1989年   1篇
  1987年   1篇
  1983年   1篇
  1981年   1篇
  1977年   1篇
  1976年   1篇
  1974年   3篇
  1964年   1篇
排序方式: 共有557条查询结果,搜索用时 15 毫秒
101.
102.
Objective: This review sought to determine the strength of the scientific evidence relating to the therapeutic use of hyperbaric oxygen for traumatic brain injury or stroke. In order to reduce the possibility of omitting relevant human clinical trials, parallel searches of the Medline, HealthStar and Embase databases were undertaken, and input was sought from local experts in hyperbaric medicine as well as from a widely noted proponent of this therapy. Papers retrieved were reviewed to ensure that they reported the results of comparative clinical trials and were then reviewed by a panel of scientists. Papers were scrutinized for methodological flaws, and the clinical significance of the results was examined.

Outcome: The strongest papers indicated either no effect or harm from hyperbaric oxygen when used to treat traumatic brain injuries or strokes.

Conclusion: The scientific literature up to August 2001 does not support the use of hyperbaric oxygen for traumatic brain injuries and strokes.  相似文献   
103.
104.
105.
PURPOSE: To determine the impact of visual impairment on functional vision of children in a rural population of south India. METHODS: A visual function questionnaire (LVP-VFQ) was administered to 1194 children aged 7 to 15 years identified through a systematic random sampling technique from 144 hamlets of Kariapatti in rural south India as part of a larger population-based project. Visual acuity estimations and clinical examinations for morbidity were performed in these 1194 children. A Rasch analysis was performed to validate the use of the instrument in this population. Bootstrap estimates (95% confidence intervals) of the regression coefficients were used to compare visual function scores between children with normal sight and children with uncorrected monocular and binocular visual impairment. RESULTS: The mean age of children was 10.3 +/- 2.1 years. The reliability estimates were 0.82 for person ability and 0.88 for item difficulty parameters, according to the Rasch analysis. A separation index of 2.15 was obtained for person measures and 2.74 for item measures, and the mean square infit and outfit statistics were 1.03 (Z(STD) 0.1) and 0.99 (Z(STD) -0.1), respectively. Children with monocular visual impairment (bootstrap estimate [95%CI] -0.05 [-0.08 to -0.01]) and binocular visual impairment (bootstrap estimate [95%CI] -0.09 [-0.11 to -0.07]) were more likely to have functional visual deficits than were normally sighted peers. CONCLUSIONS: Monocular or binocular visual impairment impacts on the functional vision of children in this rural population. Further studies are needed to determine the impact of treatment of visual impairment on functional vision in children of this population.  相似文献   
106.
BACKGROUND: The Kidney Early Evaluation Program (KEEP 2.0) cross-sectional, community-based study, targeted individuals at increased risk for kidney disease and measured blood glucose, creatinine, and hemoglobin. METHODS: KEEP 2.0 screening data were used to determine the prevalence of anemia by level of kidney function and diabetes status. Estimated glomerular filtration rate (EGFR) was calculated using serum creatinine values, and categorized as > or =90, 60-89, 30-59 and <30 mL/min/1.73 m(2). Anemia was defined as hemoglobin <12 g/dL in men and in women aged >50 years, and <11 g/dL in women < or =50 years. Diabetes was defined as participant-reported diagnosis, fasting glucose >125 mg/dL, or nonfasting glucose >200 mg/dL. RESULTS: Data were available on 5380 participants screened from August 2000 through December 2001. Diabetes was present in 26.9% of participants, and anemia in 7.7%; 15.9% of participants had at least moderately reduced kidney function (EGFR <60 mL/min/1.73 m(2)). In participants with diabetes, anemia prevalence at the 4 levels of descending EGFR were 8.7%, 7.5%, 22.2%, and 52.4%, compared with 6.9%, 5.0%, 7.9%, and 50.0% in persons without diabetes. In a multivariable model, participants of non-white race/ethnicity, those with diabetes and those with EGFR <30 or 30-59 mL/min/1.73 m(2) had significantly increased odds of anemia. In addition, a significant sex-diabetes interaction was identified; odds of anemia were 4-fold greater in men than women with diabetes relative to sex-matched participants without diabetes. CONCLUSION: Diabetes was independently correlated with anemia, more so in men than women, and may be linked to premature expression of anemia in persons with moderate reductions in kidney function.  相似文献   
107.
Behavioral and social issues were investigated in 363 phase I/II preventive HIV-1 vaccine trial volunteers in Thailand. These issues included risk behavior, HIV knowledge, distress, and social consequences of vaccine trial participation. Data were collected at baseline and at 4-, 8-, and 12-month follow-up visits. Volunteers reported relatively low levels of risk behaviors at baseline and at follow-up. Overtly negative reactions from family or friends were reported by 5.9%. No experiences of discrimination in employment, health care, or insurance were reported. Mean levels of distress were low throughout the trial, and HIV-related knowledge was high, although it was common to consider the possibility of HIV transmission through casual contact. Findings add to the evidence that preventive HIV vaccine trials are feasible in Thailand.  相似文献   
108.
In response to welfare reform and the Food Stamp Nutrition Education Program's (FSNEP) goal of increasing clients' self-sufficiency, a literature review and small exploratory study were conducted to gain insight into a potential approach that would go beyond current nutrition education methods. Interviews with 17 FSNEP participants showed a widespread willingness to share food-related skills that others wanted to learn, some interest in cooperating on food-related projects, and frequent cases of social and geographic isolation. Based on these preliminary findings, we suggest the development and evaluation of nutrition education programs that appreciate and build on existing abilities of participants, provide opportunities for self-directed learning and activities, and build social support, social networks, and trust among participants while linking them to the broader community.  相似文献   
109.
Vaccine-induced T-cell memory for human immunodeficiency virus type 1 (HIV-1) was assessed by measuring HIV-1 antigen-stimulated cytokine secretion in 72 HIV-1-uninfected subjects, of whom 52 received live recombinant canarypox virus vaccine expressing HIV-1 env, gag, and protease gene products (vCP205) with or without HIV-1(SF-2) recombinant gp120 (SF-2 rgp120) subunit vaccine, and 20 the control. The vCP205 vaccine induced secretion of the Th1 cytokine, interferon-gamma, by peripheral blood mononuclear cells (PBMC) after in vitro stimulation with HIV-1 p24 and envelope glycoprotein. Immunization schedules with both vCP205 and SF-2 rgp120 subunit vaccines induced secretion of Th1 and Th2 cytokines by PBMC to HIV-1 envelope glycoprotein. Hence, vCP205 and SF-2 rgp120 subunit vaccines given together and in a prime-boost sequence appeared to induce a broader cytokine response pattern than vCP205 vaccine given alone.  相似文献   
110.
OBJECTIVE: To demonstrate that individualized optimal fetal growth norms, accounting for physiologic and pathologic determinants of fetal growth, better identify normal and abnormal outcomes of pregnancy than existing methods. METHODS: In a prospective cohort of 38,033 singleton pregnancies, we identified 9,818 women with a completely normal outcome of pregnancy and characterized the physiologic factors affecting birth weight using multivariable regression. We used those physiologic factors to individually predict optimal growth trajectory and its variation, growth potential, for each fetus in the entire cohort. By comparing actual birth weight with growth potential, population, ultrasound, and customized norms, we calculated for each fetus achieved percentiles, by each norm. We then compared proportions of pregnancies classified as normally grown, between 10th and 90th percentile, or aberrantly grown, outside this interval, by growth potential and traditional norms, in 14,229 complicated pregnancies, 1,518 pregnancies with diabetes or hypertensive disorders, and 1,347 pregnancies with neonatal complications. RESULTS: Nineteen physiologic factors, associated with maternal characteristics and early placental function, were identified. Growth potential norms correctly classified significantly more pregnancies than population, ultrasound, or customized norms in complicated pregnancies (26.4% compared with 18.3%, 18.7%, 22.8%, respectively, all P<.05), pregnancies with diabetes or hypertensive disorders (37.3% compared with 23.0%, 28.0%, 34.0%, respectively, all P<.05) and neonatal complications (33.3% compared with 19.7%, 24.9%, 29.8%, respectively, all P<.05). CONCLUSION: Growth potential norms based on the physiologic determinants of birth weight are a better discriminator of aberrations of fetal growth than traditional norms. LEVEL OF EVIDENCE: II.  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