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   1004篇
  免费   97篇
  国内免费   46篇
耳鼻咽喉   6篇
儿科学   74篇
妇产科学   31篇
基础医学   96篇
口腔科学   37篇
临床医学   170篇
内科学   210篇
皮肤病学   27篇
神经病学   47篇
特种医学   156篇
外科学   73篇
综合类   26篇
预防医学   65篇
眼科学   12篇
药学   56篇
  1篇
中国医学   9篇
肿瘤学   51篇
  2023年   2篇
  2021年   9篇
  2020年   8篇
  2019年   6篇
  2018年   22篇
  2017年   24篇
  2016年   26篇
  2015年   28篇
  2014年   36篇
  2013年   44篇
  2012年   18篇
  2011年   30篇
  2010年   41篇
  2009年   68篇
  2008年   28篇
  2007年   47篇
  2006年   19篇
  2005年   25篇
  2004年   11篇
  2003年   16篇
  2002年   10篇
  2001年   21篇
  2000年   14篇
  1999年   23篇
  1998年   72篇
  1997年   82篇
  1996年   57篇
  1995年   51篇
  1994年   37篇
  1993年   43篇
  1992年   14篇
  1991年   9篇
  1990年   12篇
  1989年   26篇
  1988年   22篇
  1987年   27篇
  1986年   14篇
  1985年   20篇
  1984年   11篇
  1983年   14篇
  1982年   10篇
  1981年   8篇
  1980年   9篇
  1978年   5篇
  1977年   11篇
  1976年   5篇
  1975年   2篇
  1934年   1篇
  1931年   1篇
  1930年   1篇
排序方式: 共有1147条查询结果,搜索用时 531 毫秒
91.
92.
A significant recent advance that has occurred world over in the continuously evolving field of Magnetic Resonance Imaging (MRI) practice is the introduction of Cardiac applications. Cardiac MRI has moved to the centre stage of clinical management strategy by non-invasively imaging the structure as well as function of the heart. It has a wide range of specific applications such as delineation of morphological anatomy, quantification of flow and pressure across cardiac valve dysfunction, evaluation of myocardial function, assessment of infarcts, mapping coronary arteries and so on. Evaluation of congenital heart disease (CHD) is an important application of Cardiac MRI since the morphological details of chambers, septum, defects and anomalous connections are depicted accurately. Besides, flow information across valves, chambers, outflow tracts and shunts are also provided. This article describes our experience in the use of cardiac MRI in congenital heart disease.Key Words: Cardiac MRI, Congenital heart disease, Cyanotic and Acyanotic heart disease  相似文献   
93.
94.
Developing information literacy: a key to evidence-based nursing   总被引:9,自引:0,他引:9  
This report describes the evaluation of a curriculum-integrated programme designed to help students develop an awareness of the nursing literature, the skills to locate and retrieve it, and skills required in its evaluation; in other words'information literacy'. Positive changes in student performance on objective measures of information-literacy skills were revealed as well as a significant increase in the levels of confidence of the student in performing those skills. Students who had undertaken the information-literacy programme ('programme' students) performed better on a range of objective measures of information literacy, as well as reporting higher levels of confidence in these skills, than students who had not participated in the programme ('non-programme' students). Evaluation of this programme provides evidence of the potential usefulness of a curriculum-integrated approach for the development of information-literacy skills within nursing education. With these underlying skills, students will be better equipped to consolidate and extend their key information-literacy skills to include research appreciation and application. These are vital for effective lifelong learning and a prerequisite to evidence-based practice.  相似文献   
95.
Purpose.?To explore disability in women with fibromyalgia with a focus on their work situation.

Method.?Review of literature on work status of women with fibromyalgia.

Results.?Major differences exist between studies in reported disability and in the percentages of women working. Limitations caused by pain, fatigue, decreased muscle strength, and endurance influence work capacity. However, 34?–?77% of the women work. Individual adjustments in the work situation are reported. When the women find a level that matches their ability, they continue to work and find satisfaction in their work role. Many factors besides degree of impairment or disability influence whether clients with longstanding pain can remain in their work role or return to work after sickness leave.

Conclusion.?The total life situation, other commitments, type of work tasks, the ability to influence the work situation, and the physical and psychosocial work environment are important factors in determining whether a person can remain in a work role. More knowledge is needed about how to adjust work conditions for people with partial work ability to the benefit of society and the individual.  相似文献   
96.
97.
Pineal germinoma: MR imaging   总被引:6,自引:0,他引:6  
Magnetic resonance (MR) imaging characteristics of pineal germinomas are described in seven patients imaged with MR and computed tomography (CT). In patients with symptoms of an enlarging process in the quadrigeminal plate cistern, MR imaging was as sensitive as CT scanning in detecting the mass. MR imaging did not detect a normal-sized, calcified neoplastic gland. Germinoma, germinoma with embryonal cell carcinoma elements, and pineoblastoma demonstrated different MR signal characteristics. Although direct coronal and sagittal MR images were useful in defining the relationship of the tumor to the posterior third ventricle, Sylvian aqueduct, and vein of Galen, the ease, rapidity, and sensitivity of CT scanning suggest that CT should remain the modality of choice for initial evaluation and screening of the pineal region, especially in the younger pediatric population, in whom detection of calcification may provide the only clue of an abnormality.  相似文献   
98.
Twenty patients with angiographically proved occlusion of the internal carotid artery (ICA) (19 unilateral, one bilateral) were studied with magnetic resonance (MR) imaging, iodine-123 iodoamphetamine (IMP) single photon emission computed tomography (SPECT), xenon-133 SPECT, and computed tomography (CT). All patients had a history of stroke or prolonged reversible ischemic neurologic deficit for more than 4 weeks. By regions of interest, T1, T2, regional cerebral blood flow (rCBF), and the number and size of the lesions were determined. The data were expressed as interhemispheric ratios (diseased/nondiseased). The highest ratios obtained were for MR imaging (T1, 2.60 +/- 0.42; T2, 1.61 +/- 0.22 [mean +/- standard deviation]) followed by Xe-133 SPECT (0.58 +/- 0.13) and IMP SPECT (0.56 +/- 0.13). Correlation coefficients for MR imaging (1/T1, 1/T2) and IMP SPECT were below .21. The lesion size was greatest on IMP SPECT images, intermediate on MR images, and least on CT scans. However, MR imaging was superior in detection of pathologic areas (detection rates: MR, 100%; IMP SPECT, 91%; CT, 79%). Relaxation times do not correlate with rCBF.  相似文献   
99.
100.
Venous clots: evaluation with MR imaging   总被引:2,自引:0,他引:2  
In vitro and in vivo studies were performed to determine the proton relaxation and imaging characteristics of static blood and acute and organized clot in canine jugular veins. In vivo, it was found that two inversion recovery sequences using a short inversion time (100 msec) demonstrated better differentiation of signal intensity of intravascular clot from surrounding soft tissues than did standard T1- and T2-weighted sequences. In vitro, quantitative measurements showed marked reduction of both T1 and T2 relaxation time of acute clot compared with stagnant blood. In addition, the T1 relaxation time, and to a lesser extent the T2 relaxation time, shortened as the clot aged, indicating a potential role for magnetic resonance imaging in determining the age of venous thrombi.  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