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   308篇
  免费   36篇
  国内免费   1篇
耳鼻咽喉   19篇
儿科学   15篇
妇产科学   1篇
基础医学   46篇
口腔科学   1篇
临床医学   19篇
内科学   73篇
皮肤病学   1篇
神经病学   61篇
特种医学   10篇
外科学   22篇
综合类   16篇
预防医学   48篇
药学   3篇
肿瘤学   10篇
  2022年   3篇
  2021年   12篇
  2020年   2篇
  2019年   3篇
  2018年   8篇
  2017年   2篇
  2016年   2篇
  2015年   9篇
  2014年   8篇
  2013年   12篇
  2012年   13篇
  2011年   15篇
  2010年   28篇
  2009年   11篇
  2008年   9篇
  2007年   14篇
  2006年   13篇
  2005年   17篇
  2004年   11篇
  2003年   12篇
  2002年   12篇
  2001年   11篇
  2000年   16篇
  1999年   12篇
  1998年   3篇
  1997年   5篇
  1996年   4篇
  1995年   2篇
  1994年   5篇
  1993年   3篇
  1992年   10篇
  1991年   3篇
  1990年   8篇
  1989年   9篇
  1988年   4篇
  1987年   1篇
  1986年   4篇
  1985年   6篇
  1984年   3篇
  1982年   1篇
  1981年   8篇
  1980年   1篇
  1977年   2篇
  1976年   1篇
  1973年   1篇
  1972年   1篇
  1971年   1篇
  1969年   1篇
  1968年   2篇
  1965年   1篇
排序方式: 共有345条查询结果,搜索用时 15 毫秒
1.
To gauge the accuracy of ultrafast CT in measuring cardiac output and myocardial perfusion in humans, measurements of continuous and pulsatile flow were made in a large asymmetrical phantom. The variation in the relationship between Hounsfield number and contrast concentration was assessed in a human thorax phantom. Radiopaque contrast medium was injected during perfusion of the phantom at a range of flow rates between 1.5 and 8 L/min. The phantom was scanned in two modes (50 and 100 ms) during continuous and pulsatile flow and with the phantom surrounded by air and by water. Flow in the tubes was calculated using indicator dilution theory, and flow in the tissue-equivalent chamber was calculated by applying first-pass distribution principles. The standard deviation of the difference between calculated and measured flow varied from 0.2 to 0.6 L/min, giving 95% limits of agreement from 0.4 to 1.2 L/min. The constant (K) relating Hounsfield unit number to iodine concentration varied widely both in different locations within the phantom and under different scan conditions (17.2-27.6 HU/mg I). Within a human thorax phantom, K varied from 14.15 to 23.18 HU/mg I and was dependent on location within the thorax phantom, the scan mode, and the cross-sectional diameter of the phantom. These data suggest that though the ultrafast CT scanner can measure continuous and pulsatile flow accurately in tubes, precise measurements of cardiac output in humans will require K to be assessed for each subject. Measurements of flow in tissue should be possible.  相似文献   
2.
BACKGROUND: A randomized trial of a primary care-based intervention to prevent depression relapse resulted in improved adherence to long-term antidepressant medication and depression outcomes. We evaluated the effects of this intervention on behavioural processes and identified process predictors of improved depressive symptoms. METHOD: Patients at high risk for depression recurrence or relapse following successful acute phase treatment (N=386) were randomly assigned to receive a low intensity 12-month intervention or continued usual care. The intervention combined education about depression, shared decision-making regarding use of maintenance pharmacotherapy and cognitive-behavioural strategies to promote self-management. Baseline, 3, 6, 9 and 12-month interviews assessed patients' self-care practices, self-efficacy for managing depression and depressive symptoms. RESULTS: Intervention patients had significantly greater self-efficacy for managing depression (P<0.01) and were more likely to keep track of depressive symptoms (P<0.0001), monitor early warning signs (P<0.0001), and plan for coping with high risk situations (P<0.0001) at all time points compared to usual care control patients. Self-efficacy for managing depression (P<0.0001), keeping track of depressive symptoms (P=0.05), monitoring for early warning signs (P=0.01), engaging in pleasant activities (P<0.0001) and engaging in social activities (P<0.0001) positively predicted improvements in depression symptom scores. CONCLUSIONS: A brief intervention designed to target cognitive-behavioural factors and promote adherence to pharmacotherapy in order to prevent depression relapse was highly successful in changing several behaviours related to controlling depression. Improvements in self-efficacy and several self-management behaviours that were targets of the intervention were significantly related to improvements in depression outcome.  相似文献   
3.
We describe a mother and daughter with a distinct phenotype that is different from previous reports. This is likely to constitute a new syndrome for which we propose the mnemonic GMS for G goniodysgenesis, M mental deficiency, and S short stature. The pattern of occurrence is compatible with either autosomal dominant or X-linked inheritance.  相似文献   
4.
To increase mammography participation, the authors implemented an outreach intervention translating concepts from expectancy value theory into a motivational interviewing telephone intervention that included the opportunity to schedule a screening appointment. Process data are presented from 491 women who had not scheduled a mammogram within 2 months of receiving a mailed invitation from a managed care organization's centralized breast cancer screening program. A total of 83% of targeted women accepted the counseling calls. Counselors rated 84% of completed calls as either receptive or neutral in tone. Women with prior mammography experience were more likely to be receptive and to schedule a screening appointment during the calls than were women with no prior experience. Topics discussed during the calls also differed between women with and without prior mammography experience. Implications for dissemination of counseling interventions in health care organizations are discussed.  相似文献   
5.
OBJECTIVE: This study was undertaken to evaluate a smoking cessation intervention provided to women smokers as follow-up to cervical cancer screening. METHODS: Women who had had a Pap test in the prior month (N = 4,053) were called to complete a survey that assessed smoking status; 580 identified smokers were randomized to receive Usual care (n = 292) or a Self-help intervention (n = 288) that included a self-help booklet, a smoking and reproductive health information card, and three telephone counseling calls. Women were followed up at 6 and 15 months post-base line. RESULTS: Cessation rates in the Usual care (UC) and Self-help (SH) groups did not differ at the 6-month (UC 10.5% vs SH 10.9%, P = 0.56) or 15-month follow-up (UC 15.5% vs SH 10.6%, P = 0.17). Among women with an abnormal Pap test result there were no differences by study group in cessation rates at 6-month (UC 9.8% vs SH 11.0%, P = 0.71) or 15-month follow-up (UC 14.6% vs SH 13.4%, P = 0.96). CONCLUSION: Integrating interventions into the clinical setting and involving providers at the point of care may have greater potential for capitalizing on this "teachable moment." Copyright 1999 American Health Foundation and Academic Press.  相似文献   
6.
Objectives : To determine the 3 year safety and efficacy of crush‐stenting with paclitaxel‐eluting stents. Background : The optimum two‐stent strategy for treatment of coronary bifurcation lesions is undetermined. Crush‐stenting is advocated to minimize restenosis through complete circumferential stent coverage; long‐term follow‐up data are lacking. Methods and Results : In a single center prospective registry, 100 consecutive patients with bifurcation lesions were treated with the Crush technique. The vast majority (93%) were true bifurcations, predominantly involving the left anterior descending and diagonal arteries. Technical success was 98%. Final kissing balloon dilatation, which became standard practice during the study, was attempted in 68 patients and successful in 51. Abciximab was used in all cases. There were no peri‐procedural stent thromboses. Follow‐up was 100% at 3 years. Symptom‐driven target lesion revascularisation was 8% at 3 years. Cumulative 3‐year major adverse cardiac events was 28% (7 cardiac deaths, 15 myocardial infarctions, 11 target vessel revascularisations). Absence of a final kissing inflation predicted repeat revascularisation but not death, infarction or stent thrombosis. Three probable stent thromboses occurred, of which two were very late. Conclusion : Where a two‐stent bifurcation strategy is required, Crush‐stenting with paclitaxel‐eluting stents is safe and effective in the long‐term. Failure to perform a final kissing dilatation increases the likelihood of revascularisation but not other adverse events. © 2009 Wiley‐Liss, Inc.  相似文献   
7.

Background  

Interventions are needed which can successfully modify more than one disease risk factor at a time, but much remains to be learned about the acceptability, feasibility, and effectiveness of multiple risk factor (MRF) interventions. To address these issues and inform future intervention development, we conducted a randomized pilot trial (n = 52). This study was designed to assess the feasibility and acceptability of the Step Up program, a MRF cognitive-behavioral program designed to improve participants' mental and physical well-being by reducing depressive symptoms, promoting smoking cessation, and increasing physical activity.  相似文献   
8.
BackgroundThe Ponseti method is the preferred treatment for idiopathic clubfoot. Although popularised by orthopaedic surgeons it has expanded to physiotherapists and other health practitioners. This study reviews the results of a physiotherapist-led Ponseti service for idiopathic and non-idiopathic clubfeet and compares these results with those reported by other groups.MethodA prospective cohort of clubfeet (2005–2012) with a minimum 2-year follow-up after correction was reviewed. Physiotherapists treated 91 children—41 patients (69 feet) had non-idiopathic deformities and 50 children (77 feet) were idiopathic. Objective outcomes were evaluated and compared to results from other groups managing similar patient cohorts.ResultsThe mean follow-up was 4.6 years (range 2–8.3 years) for both groups. The non-idiopathic group required a median of 7 casts to correct the clubfoot deformity with an 83 % tenotomy rate compared to a median of 5 casts for the idiopathic group with a 63 % tenotomy rate. Initial correction was achieved in 96 % of non-idiopathic feet and in 100 % of idiopathic feet. Recurrence requiring additional treatment was higher in the non-idiopathic group with 40 % of patients (36 % of feet) sustaining a relapse as opposed to 8 % (6 % feet) in the idiopathic group. Surgery was required in 26 % of relapsed non-idiopathic feet and 6 % of idiopathic.ConclusionsAlthough Ponseti treatment was not as successful in non-idiopathic feet as in idiopathic feet, deformity correction was achieved and maintained in the mid-term for the majority of feet. These results compare favourably to other specialist orthopaedic-based services for Ponseti management of non-idiopathic clubfeet.

Level of evidence

Prognostic Level III.  相似文献   
9.
10.
The focus on recovery, not just symptom reduction, in mental health care brings a need for psychometrically sound measures of recovery. This study examined the factor structure and sensitivity to change of a common measure of mental health recovery, the Recovery Assessment Scale (RAS). We conducted a secondary data analysis from a randomized clinical trial of self-management for depression (n = 302). We tested both bifactor and the previously found five-factor model. Sensitivity to change was examined three ways: (1) between the intervention and control group; (2) across time in the intervention group; and (3) in those whose depression remitted. The previous five-factor model was supported. One subscale, no domination by symptoms, was particularly sensitive to change and showed sensitivity to change whereas the subscale reliance on others did not show change in any of the comparisons. Results suggest that the subscales of the RAS should be examined separately in future studies of recovery.  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