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   363篇
  免费   14篇
耳鼻咽喉   2篇
儿科学   4篇
妇产科学   5篇
基础医学   47篇
口腔科学   4篇
临床医学   19篇
内科学   62篇
皮肤病学   6篇
神经病学   94篇
特种医学   4篇
外科学   33篇
综合类   1篇
预防医学   23篇
眼科学   22篇
药学   26篇
中国医学   4篇
肿瘤学   21篇
  2022年   7篇
  2021年   8篇
  2020年   6篇
  2019年   9篇
  2018年   13篇
  2017年   8篇
  2016年   5篇
  2015年   3篇
  2014年   11篇
  2013年   23篇
  2012年   14篇
  2011年   24篇
  2010年   10篇
  2009年   9篇
  2008年   10篇
  2007年   21篇
  2006年   18篇
  2005年   16篇
  2004年   13篇
  2003年   12篇
  2002年   10篇
  2001年   12篇
  2000年   11篇
  1999年   11篇
  1998年   3篇
  1997年   4篇
  1995年   5篇
  1993年   2篇
  1992年   7篇
  1991年   2篇
  1990年   3篇
  1989年   3篇
  1988年   3篇
  1987年   7篇
  1986年   3篇
  1985年   5篇
  1984年   5篇
  1981年   3篇
  1979年   2篇
  1976年   4篇
  1973年   3篇
  1972年   2篇
  1968年   6篇
  1959年   2篇
  1936年   1篇
  1935年   2篇
  1934年   1篇
  1929年   1篇
  1927年   1篇
  1874年   1篇
排序方式: 共有377条查询结果,搜索用时 15 毫秒
101.
The reliability of ankle-brachial index (ABI) measurements performed by different observer groups in primary care has not yet been determined. The aims of the study were to provide precise estimates for all effects influencing the variability of the ABI (patients' individual variability, intra- and inter-observer variability), with particular focus on the performance of different observer groups. Using a partially balanced incomplete block design, 144 unselected individuals aged > or = 65 years underwent double ABI measurements by one vascular surgeon or vascular physician, one family physician and one nurse with training in Doppler sonography. Three groups comprising a total of 108 individuals were analyzed (only two with ABI < 0.90). Errors for two repeated measurements for all three observer groups did not differ (experts 8.5%, family physicians 7.7%, and nurses 7.5%, p = 0.39). There was no relevant bias among observer groups. Intra-observer variability expressed as standard deviation divided by the mean was 8%, and inter-observer variability was 9%. In conclusion, reproducibility of the ABI measurement was good in this cohort of elderly patients who almost all had values in the normal range. The mean error of 8-9% within or between observers is smaller than with established screening measures. Since there were no differences among observers with different training backgrounds, our study confirms the appropriateness of ABI assessment for screening peripheral arterial disease (PAD) and generalized atherosclerosis in the primary case setting. Given the importance of the early detection and management of PAD, this diagnostic tool should be used routinely as a standard for PAD screening. Additional studies will be required to confirm our observations in patients with PAD of various severities.  相似文献   
102.
103.
The basic aim of this study was to evaluate the current accepted standard clinical endpoint for the earliest‐studied HD participants likely to be recruited into clinical trials. As the advent of genetic testing for HD, it is possible to identify gene carriers before the diagnosis of disease, which opens up the possibility of clinical trials of disease‐modifying treatments in clinically asymptomatic persons. Current accepted standard clinical endpoints were examined as part of a multinational, 32‐site, longitudinal, observational study of 786 research participants currently in the HD prodrome (gene‐positive but not clinically diagnosed). Clinical signs and symptoms were used to prospectively predict functional loss as assessed by current accepted standard endpoints over 8 years of follow‐up. Functional capacity measures were not sensitive for HD in the prodrome; over 88% scored at ceiling. Prospective evaluation revealed that the first functional loss was in their accustomed work. In a survival analysis, motor, cognitive, and psychiatric measures were all predictors of job change. To our knowledge, this is the first prospective study ever conducted on the emergence of functional loss secondary to brain disease. We conclude that future clinical trials designed for very early disease will require the development of new and more sensitive measures of real‐life function. © 2010 Movement Disorder Society  相似文献   
104.
105.
The role and future of endoscopic imaging systems.   总被引:2,自引:0,他引:2  
M O Schurr  W Kunert  A Arezzo  G Buess 《Endoscopy》1999,31(7):557-562
Visual perception is the main sensory input from the environment in most situations of daily life. It is the only sensory input from the operating field in endoscopic surgery, and thus the qualities of the optical imaging system have a considerable impact on the course of the surgical intervention. Significant improvements have been made recently in various fields of science and engineering, influencing endoscopic imaging systems in experimental and clinical use. Among these are technologies that improve the endoscope itself in terms of providing new visual features, such as fogging prevention and plastic images, using new illumination techniques. Other developments concern the improvement of image resolution and color fidelity through new charge-coupled device (CCD) sensors or alternative techniques for image creation. Finally, the combination of endoscopic technologies with robotics provides for intuitive and more efficient direction of the line of sight.  相似文献   
106.
BACKGROUND: Although lead exposure has steadily decreased in the last few years, some lead is still used in the metal processing industry, mostly for wall paints and plumbing. Recent studies on children showed neurobehavioral effects of low-level exposure, but little is known about the neurocognitive effects of lead concentrations in the upper reference range on adults. METHODS: The neuropsychological effects of lead exposure were examined in 39 adult outpatients at the Unit of Environmental Medicine (UEM), University Hospital, Aachen, Germany. All patients underwent a comprehensive medical examination, including psychiatric. Venous blood and urine samples were collected and tested for heavy metals and selenium. Since the neuropsychological examination was not expected to reveal any severe abnormalities, only specific attentiveness functions were analyzed (alertness, working memory, flexibility, intermodal comparison) since these areas were the likeliest to show objectifiable effects. The tests were conducted using a standardized computerized battery. RESULTS: Lead blood levels ranged from 1 to 65.6 microg/l (mean 27.4 +/- 16.2 microg/l). Although the neuropsychological test results of all patients were within the normal range, there were significant correlations between blood lead levels and the speed of information processing for working memory. CONCLUSIONS: The results indicate working memory dysfunctions in adults, the severity of which correlates directly with blood lead levels, supporting the hypothesis that increased blood lead levels can also be associated with measurable neurocognitive abnormalities.  相似文献   
107.

Background

The shortage of supervised practice sites in dietetics is associated with fewer numbers of preceptors available to supervise interns, especially in the clinical setting.

Objective

To identify clinical dietitians’ perceived benefits and challenges of training dietetic interns and to determine key motivators that would entice nonpreceptors to volunteer for the role.

Design

Registered dietitian nutritionists working in clinical settings completed a semi-structured, audiotaped interview followed by a brief questionnaire.

Participants

Clinical dietitians working in hospitals, long-term care facilities, and outpatient clinics (n=100) participated: 54 preceptors and 46 nonpreceptors.

Statistical analysis

Qualitative analysis was conducted using an iterative process to identify and code common themes. T tests were used to compare mean differences between the opinions of preceptors and nonpreceptors.

Results

Preceptors had approximately 5 more years of experience (mean=14.27±12.09 years) than nonpreceptors (mean=8.83±9.72 years) (P< 0.01). Furthermore, preceptors reported twice as many benefits to mentoring interns (mean=6.7 mentions/participant) as nonpreceptors (mean=3.4 mentions/participant), including knowledge gains and staying current. Lack of time was consistently noted as a barrier in interviews and rated as the greatest barrier in the survey. Both groups rated receiving continuing professional education units (CPEUs) for precepting as the greatest potential motivator for taking on interns.

Conclusions

Incentive programs should be developed to entice nonpreceptors to take on interns. These programs should include extensive training on the preceptor role and how to alleviate the burden of time spent supervising interns and should provide a significant number of CPEUs to make the added workload worthwhile.  相似文献   
108.
The authors designed an instrument, the Health Attitude Survey, to assess somatization, and administered it to over 1,000 patients attending a general medicine clinic. Within this population, a series of somatizing patients and control patients were identified for purposes of developing and testing the instrument. The 27-item scale was rapidly administered and acceptable to the patients. Based on comparisons with other measures of somatization, the instrument appeared to be a valid measure of the attitudes and perceptions of somatizing patients, and it distinguished these patients from the control subjects. The measure showed acceptable predictive value and may prove useful in clinical settings, where rapid screening is desired.  相似文献   
109.
In borderline and antisocial personality disorder there is a close interaction between affect dysregulation and impulse control disorder. Different approaches are presented that focus on affective responses to experimental stimuli in these personality disorders. Results suggest that in borderline personality disorder intense emotional responses occur in the context of specific stressors, in particular fear of being abandoned. Evidence for a general emotional hyperreactivity was not found; on the contrary, female borderline subjects rather showed reduced emotional arousal. Regarding the psychopathic subtype of antisocial personality disorder, results provided strong support for the theory of emotional detachment, which may predispose to violence through a lack of feeling of fear or also of compassion which could counteract violent impulses. Consequences for psychotherapy in BPD are considered.  相似文献   
110.
The association of a HOPA polymorphism with major depression and phobia   总被引:4,自引:0,他引:4  
Thyroid hormone has a prominent role in the development and homeostasis of the central nervous system (CNS). Consequently, genes participating in thyroid hormone receptor (THR)-mediated signal transduction are prime candidates for neuropsychiatric illness susceptibility factors. Previously, we have associated exonic polymorphisms in a Xq13 thyroid receptor coactivator named HOPA with a modest increase in vulnerability to a broad spectrum of neuropsychiatric illness, including depression, psychosis, and hypothyroidism. In order to test and extend these findings, we have now examined the relationship between HOPA polymorphisms and neuropsychiatric illness in a cohort of Iowa adoptees. Consistent with our prior findings, HOPA polymorphisms were associated with an increased risk for major depression. There was suggestive evidence that the increased psychiatric morbidity in these subjects could represent epistasis, e.g., an interaction between the HOPA variant and a genetic diathesis for another psychiatric condition such as biologic parent antisocial behavior. Information about biologic parent behavior and the adoptive home environment was used to determine depressive symptoms attributable to gene-environment interaction. HOPA variant subjects continued to show significant differences in depressive symptoms when controlling for gene-environment interaction. Finally, because obesity is associated with hypothyroidism and HOPA polymorphisms are associated with hypothyroidism, we analyzed weight with respect to HOPA allele status. We found that that HOPA polymorphisms were associated with increased risk for obesity (P <.001). In summary, we conclude that HOPA polymorphisms may be a moderate risk factor for increased susceptibility to a broad spectrum of neuropsychiatric illness and hypothesize that the type of illness manifested might be related to a separate genetic diathesis.  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