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   1644篇
  免费   260篇
  国内免费   21篇
耳鼻咽喉   10篇
儿科学   58篇
妇产科学   26篇
基础医学   84篇
口腔科学   73篇
临床医学   270篇
内科学   426篇
皮肤病学   39篇
神经病学   61篇
特种医学   299篇
外科学   123篇
综合类   24篇
预防医学   298篇
眼科学   11篇
药学   33篇
中国医学   5篇
肿瘤学   85篇
  2023年   51篇
  2022年   17篇
  2021年   15篇
  2020年   44篇
  2019年   20篇
  2018年   52篇
  2017年   35篇
  2016年   45篇
  2015年   54篇
  2014年   96篇
  2013年   121篇
  2012年   35篇
  2011年   51篇
  2010年   66篇
  2009年   82篇
  2008年   48篇
  2007年   74篇
  2006年   51篇
  2005年   36篇
  2004年   38篇
  2003年   15篇
  2002年   15篇
  2001年   24篇
  2000年   22篇
  1999年   29篇
  1998年   66篇
  1997年   90篇
  1996年   79篇
  1995年   57篇
  1994年   63篇
  1993年   52篇
  1992年   16篇
  1991年   12篇
  1990年   31篇
  1989年   42篇
  1988年   31篇
  1987年   34篇
  1986年   33篇
  1985年   32篇
  1984年   13篇
  1983年   13篇
  1982年   24篇
  1981年   30篇
  1980年   17篇
  1979年   7篇
  1978年   5篇
  1977年   14篇
  1976年   14篇
  1975年   10篇
  1969年   2篇
排序方式: 共有1925条查询结果,搜索用时 562 毫秒
131.
Childhood scoliosis: MR imaging   总被引:2,自引:0,他引:2  
The spinal cords of 28 scoliosis patients between the ages of 1 month and 17 years were examined with magnetic resonance (MR) imaging. Complete visualization was obtained in all cases. In 15 patients (53%) neuropathologic abnormalities demonstrated by MR imaging significantly affected their clinical course, including tethered cords (n = 7), syringomyelia (n = 5), Arnold-Chiari I malformation (n = 4), spinal cord tumors (n = 2), Arnold-Chiari II malformation (n = 3), and diastematomyelia (n = 1). The advantages of MR imaging in the evaluation of the scoliotic spine in children include a high sensitivity for the occult conditions associated with scoliosis, good anatomic demonstration of the cord, and absence of bone artifacts. MR imaging is recommended as a primary imaging modality in scoliosis, following conventional radiography.  相似文献   
132.
133.
An emerging role for nurses is that of expert witness for medical liability cases that involve nursing care. Medical liability cases require that the trier of evidence (judge or jury) have an understanding of the facts and the relevant standards of the case for equitable resolution. The attorney, judge, or jury member may not possess the information necessary to understand the issues. Someone with the requisite knowledge and skills to review the information, interpret facts, offer an opinion about whether or not the standard of care was met, and explain this to the appropriate people is crucial for the legal system to work. If nursing care is at issue, that expert is a nurse with the appropriate knowledge, experience, and education. This report explores the role, qualifications, and expectations for nurses who serve as expert witnesses. Personal insights from the authors will provide practical information for nurses who are interested in the role. Copyright © 2001 by W.B. Saunders Company  相似文献   
134.
OBJECTIVE: To identify predictors and outcomes associated with frequent emergency department (ED) users. METHODS: Cross-sectional intake surveys, medical chart reviews, and telephone follow-up interviews of patients presenting with selected chief complaints were performed at five urban EDs during a one-month study period in 1995. Frequent use was defined by four or more self-reported, prior ED visits. Multivariate logistic regression identified predictors of frequent ED visitors from five domains (demographics, health status, health access, health care preference, and severity of acute illness). Associations between high use and selected outcomes were assessed with logistic regression models. RESULTS: All study components were completed by 2,333 of 3,455 eligible patients (67.5%). Demographics predicting frequent use included being a single parent, single or divorced marital status, high school education or less, and income of less than $10,000 (1995). Health status predictors included hospitalization in the preceding three months, high ratings of psychological distress, and asthma. Health access predictors included identifying an ED or a hospital clinic as the primary care site, having a primary care physician (PCP), and visiting a PCP in the past month. Choosing the ED for free care was the only health preference predictive of heavy use. Illness severity measures were higher in frequent visitors, although these were not independently predictive in the multivariate model. Outcomes correlated with heavy use include increased hospital admissions, higher rates of ED return visits, and lower patient satisfaction, but not willingness to return to the ED or follow-up with a doctor. CONCLUSIONS: Frequent ED visits are associated with socioeconomic distress, chronic illness, and high use of other health resources. Efforts to reduce ED visits require addressing the unique needs of these patients in the emergency and primary care settings.  相似文献   
135.
Migraine-associated vertigo   总被引:2,自引:0,他引:2  
A retrospective analysis was performed on consecutive series of 363 patients presenting with vertigo; 32% had migraine. Of the 224 patients with no pathology other than migraine or vestibular dysfunction, migraineurs had a significantly higher prevalence of normal, central, and combined central and peripheral vestibular dysfunction compared to non-migraineurs. The combination of central and peripheral vestibular signs was a feature of migraine with aura. The results support the hypothesis that migraine-associated vertigo is a diagnostic entity.  相似文献   
136.
137.
SUMMARY The efficacy and safety of the methylprednisolone prodrugs methylprednisolone suleptanate and methylprednisolone sodium succinate were evaluated in a multicentre, randomised, double-blind, double-dummy parallel study of 88 patients hospitalised with acute asthma. Each study drug was administered as a bolus intravenous injection of 40mg methylprednisolone equivalents every 6 hours for 48 hours. Methylprednisolone 32mg was administered orally 6 hours after the last dose. Pulmonary function, medical events, and clinical laboratory values were assessed at predefined intervals before and during the 72-hour study. The primary response measure of pulmonary function was per cent predicted forced expiratory volume in one second (FEV1) at 48 hours. Secondary response measures were peak expiratory flow rate (PEFR) and FEV1/forced vital capacity (FVC) ratio. Although both drugs demonstrated within-group mean changes from baseline (starting at 6 hours) that were statistically significant for each response, there were no statistically significant differences between the two groups. The mean percent predicted FEV1 at 48 hours and mean per cent change from baseline were 64% and 13% (p<0.0001) for the methylprednisolone suleptanate group and 67% and 17% (p<0.0001) for the methylprednisolone sodium succinate group, respectively. The mean PEFR and FEV1/FVC ratio at 48 hours were 5.77 l/s and 73% for the methylprednisolone suleptanate group and 5.78 l/s and 76% for the methylprednisolone sodium succinate group, respectively. There were no clinically or statistically significant between-group differences in any of the safety parameters. In this study, methylprednisolone suleptanate and methylprednisolone sodium succinate have been shown to be therapeutically equivalent in the treatment of patients hospitalized with acute asthma.  相似文献   
138.
139.
The use of the newly dead to teach procedures is widely practiced in training institutions. This model allows a realistic opportunity both to become more familiar with lifesaving maneuvers before they are actually necessary and to maintain proficiency. Whether to notify the next of kin first has been an issue of ethical debate. Some argue a "don't ask, don't tell" policy is justified, while others mandate open consent by family members prior to the practice. Several medical studies have found that patients and families are likely to consent to the procedures but prefer to be asked permission first. Multiple legal cases have addressed the issue of usage of cadavers postmortem without expressed permission. Earlier cases emphasized the concept of "pseudo-property" rights and declared that the next of kin do not have constitutional ownership of the deceased person's body. More recent legal cases are declaring that families do, in fact, possess these rights. In this day and age of increasing recognition of personal autonomy, it is probably prudent to approach the next of kin for permission before performing procedures on the newly deceased.  相似文献   
140.
The authors report 2.5 years' experience with the use of cytomegalovirus (CMV)-seronegative blood components for the prevention of primary CMV infection after allogeneic marrow transplantation from seronegative marrow donors to 104 CMV-seronegative patients. Patients and blood donors were screened for CMV-seronegativity by a combination of passive latex agglutination, complement fixation, and indirect hemagglutination CMV antibody screening methods. Changes in blood banking procedures necessary to provide CMV-seronegative components are detailed. Providing CMV-seronegative components was a considerable undertaking; a mean, per patient, of 19 units of red cells and 105 units of platelets was required. Twenty percent of the platelet support was provided by family members and 80 percent by volunteer donors. CMV-infection was eliminated in all but one patient not considered infected at the time of transplantation. The capability to provide CMV-seronegative components depends on an adequate supply of seronegative donors, a sensitive and practical screening method for CMV antibody, a major commitment by the blood bank, and close communication between the blood bank and the patients' physicians.  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