全文获取类型
收费全文 | 21102篇 |
免费 | 1772篇 |
国内免费 | 39篇 |
专业分类
耳鼻咽喉 | 263篇 |
儿科学 | 650篇 |
妇产科学 | 584篇 |
基础医学 | 2780篇 |
口腔科学 | 302篇 |
临床医学 | 2840篇 |
内科学 | 3777篇 |
皮肤病学 | 326篇 |
神经病学 | 2109篇 |
特种医学 | 590篇 |
外国民族医学 | 1篇 |
外科学 | 2529篇 |
综合类 | 332篇 |
一般理论 | 15篇 |
预防医学 | 2543篇 |
眼科学 | 519篇 |
药学 | 1360篇 |
中国医学 | 23篇 |
肿瘤学 | 1370篇 |
出版年
2023年 | 135篇 |
2022年 | 243篇 |
2021年 | 500篇 |
2020年 | 338篇 |
2019年 | 419篇 |
2018年 | 566篇 |
2017年 | 432篇 |
2016年 | 438篇 |
2015年 | 481篇 |
2014年 | 695篇 |
2013年 | 995篇 |
2012年 | 1334篇 |
2011年 | 1339篇 |
2010年 | 737篇 |
2009年 | 687篇 |
2008年 | 1115篇 |
2007年 | 1085篇 |
2006年 | 1074篇 |
2005年 | 1104篇 |
2004年 | 968篇 |
2003年 | 883篇 |
2002年 | 824篇 |
2001年 | 401篇 |
2000年 | 377篇 |
1999年 | 363篇 |
1998年 | 178篇 |
1997年 | 179篇 |
1996年 | 129篇 |
1995年 | 130篇 |
1994年 | 126篇 |
1992年 | 277篇 |
1991年 | 275篇 |
1990年 | 261篇 |
1989年 | 220篇 |
1988年 | 252篇 |
1987年 | 237篇 |
1986年 | 256篇 |
1985年 | 221篇 |
1984年 | 189篇 |
1983年 | 192篇 |
1982年 | 134篇 |
1981年 | 135篇 |
1980年 | 108篇 |
1979年 | 195篇 |
1978年 | 140篇 |
1977年 | 104篇 |
1976年 | 128篇 |
1975年 | 128篇 |
1974年 | 134篇 |
1973年 | 98篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Dana R. Brock 《Early child development and care》1990,57(1):101-108
Research on children's early writing development in the past has focused primarily on product and process. In reviewing the more recent research on early writing development, however, a new focus of context emerges. Occurrences of literacy are now being observed in the home, the school, and the community. With this new emphasis, comes the task of defining context. A definition of context reflects theoretical perspectives, areas of research interests, and types of methodologies employed in conducting research. Therefore, the purpose of this article is to address the following aspects of context: #op1#cp multidiscipline perspectives and definitions of context, #op2#cp contextual shifts observed between the home and the school, #op3#cp contextual factors present when learning how to write, and #op4#cp pedagogical implications for curriculum development. 相似文献
12.
13.
Marion E. Highriter D. Sc. R.N. Irene Tessaro Dr. P.H. R.N. Elizabeth Randall-David Ph.D. R.N. Dana E. A. Quade Ph.D. 《Public health nursing (Boston, Mass.)》1995,12(5):324-334
Abstract An anonymous questionnaire was completed by 369 nurses in public health departments in a rural Southeastern state to examine the relationship between nurses' prior HIV training and their HIV-related knowledge, attitudes, concerns, and perceived training needs. The survey was conducted in three predominantly urban counties with the highest number of AIDS cases and in 38 rural counties with two or fewer reported AIDS cases. Knowledge answers were generally 70%-90% correct and attitudes more favorable than unfavorable. Attitude was more frequently associated with HIV training level than was knowledge. Concerns about working with persons with high-risk behaviors were expressed by more than half the nurses and were more prevalent in rural areas. Nurses with more training had more concerns about client care and fewer fears about HIV work. Almost all (85%) were concerned about lack of community resources. Most nurses wanted more training of the client-sensitive type provided by the state. With the increasing incidence of HIV/AIDS in rural areas, planning continuing education for staff not only on new developments and current therapies (desired by 98%) but on managing feelings about clients with high-risk behaviors seems especially important not only for the staff, but for their significant others and communities. 相似文献
14.
Hypothesis: the aging paradox and autoimmune disease. 总被引:2,自引:0,他引:2
15.
Alan G. Rose M.D. Neil G. Heselson M. Med. Richard K. Marks F.R.C.S. Dorothea Kranold F.F.RAD 《Skeletal radiology》1992,21(2):140-145
A man presented with a mass in the left first metacarpal bone. Later, his chest radiograph showed extensive, bilateral, rounded opacities in both lungs with enlarged hilar lymph nodes, and he developed expanding lesions in the left radius, ulna, and metacarpal bones. The pulmonary lesions were treated with radiotherapy and cytotoxic agents, and the tumor mass in the first metacarpal was debulked. All biopsies showed similar features of a mixed tumor (pleomorphic adenoma) with metastatic or embolic pulmonary involvement; ultrastructural and immunocytochemical investigations supported this unique diagnosis. The patient remains well 15 years after the initial diagnosis. It is possible that the myoepithelial elements in this case had been displaced intraosseously during development. We are not aware of a similar case in the literature. 相似文献
16.
The effects of beta-adrenergic blockade on cardiac transcapillary exchange were examined at rest and during sympathetic stimulation. Multiple indicator dilution experiments were carried out in closed-chest anesthetized dogs at rest and during carotid occlusion, either under basal conditions or after beta-adrenergic blockade with alprenolol. beta-Adrenergic blockade at rest had no effect on coronary flow or transcapillary exchange in comparison with the control situation, but it abolished the increase in coronary flow and in the permeability/surface area product for labeled sucrose produced by carotid occlusion. High coronary resistance values in beta-blocked animals with carotid occlusion were associated with a high degree of heterogeneity in capillary transit times, but the overall relation between coronary flow and the capillary permeability/surface area product was unchanged. The findings indicate that beta-blockade increases coronary resistance during sympathetic stimulation and, simultaneously, decreases the coronary blood flow and capillary permeability/surface area product while increasing the heterogeneity of capillary transit times. 相似文献
17.
Louise Rose MN Adult Ed Cert BN ICU Cert Dip Nurs Marie F. Gerdtz RN BN AE Cert GDAET PhD 《Australasian emergency nursing journal : AENJ》2007,10(1):26-29
The use of mechanical ventilation in the Emergency Department requires adequate resources in order to maintain patient safety and avoid potential risks. Moreover, developments in technology require increased knowledge of mechanical ventilation techniques to address the complexity of decision-making involved. Organisational issues and system factors have the potential to negatively impact on the ability of the emergency service to provide optimum care to patients receiving mechanical ventilation. These issues include staffing and skill-mix, demand on emergency services, role-delineation, scope of practice, and current mechanisms for monitoring of quality and safety. Furthermore, in response to advances in ventilator technology, current education programs for both nursing and medical staff require review to ensure that they provide comprehensive information about the types of ventilation techniques now available and the relative risks and benefits associated with their application.This article is the second in a two-part series and explores the educational and organisational factors that impact upon safety and quality of care delivered to patients receiving mechanical ventilation in the emergency department. Recommendations for future policy development, curriculum review and reporting mechanisms to support further research in the application of mechanical ventilation in the emergency department are made. 相似文献
18.
19.
J. Jarman A. Przyborowska V. Glover J. Halket P. T. G. Davies F. Clifford Rose M. Sandler 《Journal of neural transmission (Vienna, Austria : 1996)》1991,84(1-2):129-134
Summary Urinary output of endogenous monoamine oxidase (MAO) inhibitory activity, was significantly raised in serial samples collected across a migraine attack compared with collections during attack-free periods and in healthy controls, which did not differ from each other. There was a highly significant correlation in output between isatin, a major fraction of the MAO inhibitory activity, and output of the MAO inhibitory activity itself. However, although there was a tendency towards increased isatin excretion during migraine attacks, it failed to reach statistical significance. 相似文献
20.
A patient of 12 suffering from aneurysmal cyst of the ischium was studied with traditional radiology, computed tomography (CT) and magnetic resonance imaging (MRI). The advantages of MRI in the study of this pathology compared to traditional radiography and CT are assessed. It was shown that the CT and MRI techniques are superior to standard X-ray examinations in anatomic definition and in evaluating the lesions's relationships with neighbouring structures and, in particular, that MRI is superior to CT in extension. 相似文献