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   1354篇
  免费   75篇
  国内免费   2篇
耳鼻咽喉   85篇
儿科学   32篇
妇产科学   51篇
基础医学   113篇
口腔科学   25篇
临床医学   209篇
内科学   205篇
皮肤病学   17篇
神经病学   153篇
特种医学   136篇
外科学   124篇
综合类   13篇
预防医学   140篇
眼科学   5篇
药学   70篇
中国医学   1篇
肿瘤学   52篇
  2021年   25篇
  2020年   8篇
  2019年   24篇
  2018年   17篇
  2017年   14篇
  2016年   14篇
  2015年   26篇
  2014年   31篇
  2013年   39篇
  2012年   64篇
  2011年   45篇
  2010年   25篇
  2009年   28篇
  2008年   55篇
  2007年   49篇
  2006年   55篇
  2005年   61篇
  2004年   54篇
  2003年   46篇
  2002年   31篇
  2001年   46篇
  2000年   53篇
  1999年   39篇
  1998年   18篇
  1997年   15篇
  1996年   16篇
  1995年   15篇
  1994年   18篇
  1993年   16篇
  1992年   19篇
  1991年   28篇
  1990年   36篇
  1989年   29篇
  1988年   28篇
  1987年   18篇
  1986年   34篇
  1985年   24篇
  1984年   23篇
  1983年   17篇
  1982年   15篇
  1980年   17篇
  1979年   19篇
  1978年   17篇
  1977年   17篇
  1976年   13篇
  1975年   12篇
  1973年   10篇
  1970年   8篇
  1969年   7篇
  1921年   8篇
排序方式: 共有1431条查询结果,搜索用时 15 毫秒
101.
In this article, the authors simulate the effects on Federal and State Medicaid expenditures of increasing Medicaid fees to Medicare fee schedule (MFS) levels. Strict adoption of the MFS by the States would increase total Medicaid spending by approximately 4 percent, $2.5 to $2.9 billion. Because Medicaid fees vary across States, so does the impact of adopting the MFS. Medicaid spending would increase significantly in some wealthy States with large Medicaid populations and in a few small, relatively poor States. Some States currently pay more than the MFS for obstetrical services. If these fees continued at higher levels for obstetrical care, total Medicaid spending would increase by $3.5 to $4.0 billion.  相似文献   
102.
ObjectiveTo evaluate the impact of a pilot comprehensive school nutrition program modeled on Social Cognitive Theory on knowledge, intentions, self-efficacy, and intake of milk and milk alternatives (MMA) in First Nations youth.MethodsA pilot school nutrition program was implemented at Peetabeck Academy in Fort Albany, Ontario in May, 2010. The Knowledge, Self-Efficacy, and Intentions Questionnaire (KSIQ) and Waterloo Web-based Eating Behavior Questionnaire (WEB-Q) were used to assess change in attitudes and behavior from pre- to postprogram.ResultsThe KSIQ preprogram (n = 26), postprogram (n = 19); WEB-Q preprogram (n = 30), postprogram (n = 10). Improved knowledge (6.0 ± 1.5 vs 6.9 ± 1.5, P = .05) and intention scores (9.6 ± 4.4 vs 11.3 ± 4.1, P = .01) were observed.Conclusions and ImplicationsA comprehensive school nutrition program can improve knowledge and intentions for intake of MMA in First Nations youth. Environmental constraints beyond the school environment need to be addressed.  相似文献   
103.
Appropriate treatment of patients with intractable seizures requires precise identification of the type (or types) of seizure the patient experiences and correlation of this information with data from electroencephalography localizing the focus of the seizure in the brain. For such patients, the technique of "intensive monitoring" has gained rapid acceptance in the past several years as the investigative method of choice.Intensive monitoring usually entails prolonged electroencephalographic recording with simultaneous videotaping of the patient. Another common technique is prolonged monitoring of the patient's electroencephalogram (EEG) by radiotelemetry, during which time the patient is closely observed by trained personnel for suspected seizures.To compare the quality of information obtained from intensive monitoring with that from careful routine electroencephalography, the authors reviewed the medical records of 100 consecutive patients who had received both kinds of study after being referred for treatment in the special Epilepsy Treatment Unit of the University of Minnesota's Comprehensive Epilepsy Program (CEP).Success of each method was defined by ability to record an actual seizure. The routine EEG examination recorded actual seizures in 7 percent of patients in the study. With video EEG, following careful withdrawal of anticonvulsant drugs, seizures were recorded in 70 percent of patients. Telemetered EEG recorded seizure activity in 50 percent of those patients for whom the other two methods had failed to detect seizures.Intensive monitoring revealed that 60 percent of patients for whom the routine EEG study had recorded only one seizure type actually suffered from two or more types. Clinical diagnosis was changed in 84 percent of the patients. In this study, intensive monitoring was found to be far superior to the routine EEG examination as an aid to precise diagnosis of intractable seizure disorders.  相似文献   
104.
Risk factors for disability among U.S. adults with arthritis.   总被引:8,自引:0,他引:8  
This article studies risk factors for physical and social disability among U.S. adults ages 55+ who have arthritis, compared to non-arthritis persons of those ages. The dependent variables refer to difficulties in walking, physical functioning (motions and strength), personal care, and household care. The data set is the Supplement on Aging (SOA) (n = 16,148) that accompanied the 1984 National Health Interview Survey. The SOA data are cross-sectional; relationships of risk factors to disability suggest causation but do not directly demonstrate it. Logistic regressions show that risk factors are similar for arthritis and non-arthritis people, with one important exception. (1) The similarities are: For both groups, odds of disability rise with age, diminish with education, and are higher for non-whites and non-married persons. Disability rises with number of chronic diseases and impairments, and it is elevated for underweight persons (Body Mass Index (BMI) less than 20; further analysis indicates this reflects incomplete control of their severe illness status). Long duration of arthritis and recent medical care for it are associated with disability. (2) The exception is: Severe overweight (BMI greater than or equal to 30) is a disability risk factor for arthritis people, but not for non-arthritis people. Previous research has shown that obesity/overweight is a risk factor for etiology of osteoarthritis; our analysis now shows its continued importance for disability when the disease is present.  相似文献   
105.
Interest in kainate receptors has increased over the past few years. Our understanding of their physiology and pharmacology has improved markedly since their original cloning and expression in the early 1990s. For example, agonist profiles at recombinant kainate receptors have been used to identify and distinguish kainate receptors in neurons. Furthermore, the development of selective antagonists for kainate receptor subtypes has increased our understanding of the functional roles of kainate receptors in neurons and synaptic transmission. In this review we described the activity of agonists and antagonists at kainate receptors and their selectivity profiles at NMDA and non-NMDA receptors.  相似文献   
106.
107.
108.
We studied 17 patients with atherosclerotic bilateral occlusion of vertebral arteries (VA) identified by angiography. Seven had vertebrobasilar TIAs, eight a brainstem stroke (severe in two), and two had only carotid symptoms. Brainstem strokes were more frequent with bilateral intracranial occlusion (60%) than with at least one extracranial occlusion (28.6%), but long-term prognosis did not differ in these two groups. In follow-up, the mortality rate was 4.5% per year, and the stroke rate was 1.8% per year. Major functional disability was seen in 16.7% of the survivors. Bilateral distal VA occlusion may sometimes have a better prognosis than previously assumed. These findings raise doubts about the value of extra-intracranial surgical bypass procedures in patients with these lesions.  相似文献   
109.
110.
Centrilobular emphysema: CT-pathologic correlation   总被引:5,自引:0,他引:5  
Over a 5-year period, 25 patients who had undergone chest computed tomography (CT) died and were autopsied. Their lungs were fixed in the inflated state and were assessed for the presence and severity of centrilobular emphysema (CLE). Three radiologists independently evaluated the CT scans for nonperipheral low-attenuation areas, peripheral low-attenuation areas, pulmonary vascular pruning, pulmonary vascular distortion, and pulmonary density gradient. The CT criterion that best correlated with the presence and severity of CLE was the nonperipheral low-attenuation area. With this CT criterion, lung destruction was correctly identified in 13 of 15 cases. The absence of this criterion resulted in correct identification of eight of ten normal lungs. These preliminary data suggest that CLE can be reliably identified and quantified with current CT scanners.  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