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   52862篇
  免费   5782篇
  国内免费   935篇
耳鼻咽喉   750篇
儿科学   1525篇
妇产科学   1030篇
基础医学   3116篇
口腔科学   1765篇
临床医学   9810篇
内科学   7461篇
皮肤病学   911篇
神经病学   5026篇
特种医学   634篇
外国民族医学   5篇
外科学   5293篇
综合类   5495篇
现状与发展   6篇
一般理论   6篇
预防医学   7615篇
眼科学   564篇
药学   2330篇
  100篇
中国医学   1622篇
肿瘤学   4515篇
  2024年   177篇
  2023年   1263篇
  2022年   2051篇
  2021年   2843篇
  2020年   3060篇
  2019年   2940篇
  2018年   2688篇
  2017年   2732篇
  2016年   2630篇
  2015年   2359篇
  2014年   4009篇
  2013年   4521篇
  2012年   3145篇
  2011年   3099篇
  2010年   2329篇
  2009年   2550篇
  2008年   2478篇
  2007年   2455篇
  2006年   2066篇
  2005年   1759篇
  2004年   1425篇
  2003年   1207篇
  2002年   914篇
  2001年   815篇
  2000年   634篇
  1999年   466篇
  1998年   446篇
  1997年   366篇
  1996年   324篇
  1995年   283篇
  1994年   225篇
  1993年   211篇
  1992年   193篇
  1991年   127篇
  1990年   114篇
  1989年   118篇
  1988年   99篇
  1987年   67篇
  1986年   55篇
  1985年   64篇
  1984年   49篇
  1983年   30篇
  1982年   30篇
  1981年   33篇
  1980年   23篇
  1979年   16篇
  1977年   14篇
  1976年   16篇
  1975年   10篇
  1968年   13篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Background/Aims: This study was designed to assess changes in: (a) neuropsychological tests, measures of memory, quality of life and scores for anxiety and depression; (b) liver function tests; and (c) the relationship between these following transjugular intrahepatic portosystemic stent-shunt.Methods: Twenty-nine patients undergoing transjugular intrahepatic portosystemic stent-shunt for recurrent variceal haemorrhage, 12 matched patients with cirrhosis and variceal haemorrhage manage with variceal band ligation and 16 normal controls were studied. Patients in any of the groups who were clinically encephalopathic were excluded from the study. Serial changes in the conventional liver function tests and Indocyanine green clearance, and psychometric function (Hospital Anxiety Depression Scale, Rivermead Behavioral Memory Test, Quality of Life and the memory and reaction sub-tests of the Cambridge Automated Neuropsychological Test Assessment Battery) were measured prior to and 1, 3, 9 and 15 months following transjugular intrahepatic portosystemic stent-shunt.Results: Over a mean follow up of 9.1 months in the transjugular intrahepatic portosystemic stent-shunt group (range 3–28), one patient (3%) developed clinically detectable encephalopathy. Sixty-seven percent of patients with cirrhosis showed evidence of subclinical encephalopathy as compared with the control population. Significant deterioration occurred in the reaction sub-tests of the Cambridge Automated neuropsychological Test Assessment Battery in patients, both in the transjugular intrahepatic portosystemic stent-shunt group and the controls with cirrhosis, during follow up. Transjugular intrahepatic portosystemic stent-shunt was followed by significant deterioration in levels of anxiety and psychological component of the quality of life. The Rivermead Behavioural Memory Test and the memory sub-test of the Cambridge Automated Neurpsychological Test Assessment Battery did, however, improve significantly at 1 and 15 months after transjugular intrahepatic portosystemic stent-shunt, respectively. Serum alanine aminotransferase, bilirubin and indocyanine green clearance deteriorated significantly following transjugular intrahepatic portosystemic stent-shunt (p<0.001, p<0.001 and p<0.0001, respectively). Significant correlation was observed between changes in the indocyanine green clearance and changes in the complex and simple reaction time subtests of the Cambridge Automated Neuropsychological Test Assessment Battery (r=0.6 and r=0.66, respectively).Conclusions: The results of this study showed that about 67% of patients with cirrhosis were subclinically encephalopathic and that temporary deterioration occurred in the Cambridge Automated Neuropsychological Test Assessment Battery during follow up, both in patients having transjugular intrahepatic portosystemic stent-shunt and in the controls with cirrhosis. These parallel the changes in the liver function tests and indocyanine green clearance. Temporary deterioration was also observed in the Quality of Life and Hospital Anxiety Depression Scale in the transjugular intrahepatic portosystemic stent-shunt group, although the measures of memory improved. Further studies should address the biochemical mechanisms of these changes and the role of prophylactic measures.  相似文献   
102.
Abstract We investigated factors correlated with abnormal behavior in the elderly residing in a special nursing home (group A) and a psychiatric hospital (group B) using the dementia behavior disturbance scale, the mini mental state examination, the Japanese version of the Philadelphia Geriatric Center morale scale, and the ADL assessment scale. The cognitive function of group B was decreased compared with that of group A, but most activities of daily living (ADL) in the latter group were disrupted compared with those in the former. Only a few categories of ADL correlated with abnormal behavior in group A, whereas cognitive function, quality of life, and most categories of ADL correlated with abnormal behavior in group B. These results suggest that factors correlated with abnormal behavior in the elderly differ within institutions of medical and social welfare systems.  相似文献   
103.
An Intrapleural Lung Prosthesis: Rationale, Design, and Testing   总被引:1,自引:0,他引:1  
Abstract: Extracorporeal life support (ECLS or ECMO) is standard treatment for severe respiratory failure but poses many contraindications to future lung transplantation. The solution to this dilemma is the implantable gas exchange device (IGED) or artificial lung. Preliminary efforts to create such an artificial lung have been made since 1970 and include designs involving single devices, intravascular devices (i. e., IVOX), and combination heart–lung devices, Stringent requirements govern the design of such a device, the most important of which are high gas exchange efficiency, low resistance to blood flow, and size. This paper describes such a device. It incorporates large diameter inflow and outflow ports in close proximity and a low resistance wound hollow fiber core encapsulated in a compliant outer shell which conserves the work of the right ventricle. In a large animal model (adult sheep) this device was connected in line with the main pulmonary artery in series with the native lungs. This configuration has the advantages of using the lungs as an embolic filter, perfusing the lungs with fully oxygenated blood, and maintaining the integrity of the anatomy necessary for transplant. Laboratory experiments have run >8 h. Preliminary data show that the animals have remained hemodynamically stable while the devices have supported the animals completely by supplying 100% O2 saturation with PO2 values ranging from 250–350 mm Hg. Additionally, this model makes possible the study of respiratory failure without introducing other variables such as extracorporeal circuits or pumps. The other metabolic, endocrine, and reticuloendothelial functions of normal and injured lungs can now be studied more precisely by excluding these variables. Further studies are needed to evaluate this device in chronic (long–term implantation) experiments before clinical application.  相似文献   
104.
Men with prostate cancer ( n = 11) were interviewed during an in-patient period at a urological clinic, about their experiences of met and unmet needs from health professionals. Their perception of quality of life and sense of coherence were also assessed. The findings were analysed from a phenemenological-hermeneutic perspective and interpreted within the concept of transition. It was interpreted that objective functional health needs were mostly met by health professionals and subjective existential needs were mostly not met. The analysis revealed patients as passive or active receivers of care. Passive receivers were explicitly and implicitly stating unmet needs, or explicitly stating satisfaction with nursing care at the same time as implicitly contradicting, referring to their needs as bagatelles, unimportant, whereas active receivers talked about their needs explicitly with the staff and did not state implicit unmet needs. This suggests that nurses need to be aware of and have sensitive ears to undertones in statements and actively seek for patients' needs. The most important nursing care areas seemed to be to provide solutions to physical problems together with staff support including information, and acting to increase confidence in staff and staff availability. This encourages patients, wives and families, in co-operation, towards a healthy exit of transition.  相似文献   
105.
106.
Early gastric cancer manifested as brain metastasis: Report of a case   总被引:1,自引:0,他引:1  
A case of early gastric cancer, limited to submucosal layer, which was manifested as cerebral metastasis is presented herein. A 47-year-old man was admitted to Nagaoka Chuo General Hospital with convulsions and a disturbance in consciousness, where a computed tomography (CT) scan revealed a cerebral tumor in the left temporal lobe. The resected tumor was identified as a metastatic adenocarcinoma. Further investigation revealed gastric cancer involving the posterior wall of the cardia. At laparotomy, multiple and small metastases of the liver and a jejunal metastasis were found, and a palliative total gastrectomy was performed. The surgical specimen revealed a protruding, poorly differentiated medullary adenocarcinoma, with invasion of the submucosal layer. The patient died 4 months after undergoing the laparotomy. This case report is presented to make clinicians aware of the possibility that early gastric cancers may present as brain metastasis.  相似文献   
107.
Hispanics are a growing ethnic minority in the United States and one at significant risk for heart failure. Health-related quality of life (HRQL) is poor in individuals with heart failure, especially during and immediately following hospitalization. No prior research into the HRQL of Hispanics with heart failure was located. A sample of 80 individuals with heart failure, evenly divided by primary language and matched on functional status using the New York Heart Association classification system and age, was studied for 6 months following hospital discharge. Data on HRQL were collected using Spanish and English versions of the Minnesota Living with Heart Failure Questionnaire. Scores improved over time in both groups but significantly more so in the Hispanics when compared to the non-Hispanics. Group differences in HRQL could not be explained by demographics, clinical characteristics, treatment received, perceived support, or instrument response characteristics. Further exploration of this naturally occurring phenomenon may provide insight into how HRQL can be improved in the general heart failure population.  相似文献   
108.
Expression of the immediate early gene zif/268 (also termed NGFI-A, Krox 24, TIS8 and Egr-1) was investigated in awake rats following various long-term potentiation (LTP) induction protocols.zif/268 mRNA (Northern blots) and protein (immunohistochemistry) levels sharply increased following LTP, and followed a time course characteristic of other immediate early genes. When measured across 3 tetanization protocols known to produce differing degrees of LTP persistence,zif/268 induction was found to be more highly correlated with LTP duration than with the magnitude of initial LTP. These data support the hypothesis that the immediate early gene zif/268 plays a role as a third messenger in the cascade of cellular and nuclear events that govern the persistence of LTP.  相似文献   
109.
The present paper critically appraises two recent overviews of the literature on rectal cancer and quality of life (QL). These reviews focus on the Anglo-American literature, largely neglect research from other countries, and provide little stimulus regarding future research directions. As an alternative perspective we propose the concept of problem-solving oriented QL research. The major theme is that the QL concept must be integrated into the clinical arena. To begin with, QL researchers must make themselves understandable. We outline several ways in which this can be achieved: (a) placing QL in a broader concept together with outcomes that are more familiar to clinicians; (b) depicting individual patients in the form of QL profiles; (c) clarifying the psychosocial/clinical correlates of particular QL scores of interest; and (d) conducting studies with a definitive practical goal in mind and integrating practitioners and patients into the study group. We illustrate the feasibility of such a research program by performance data from our Marburg-Biedenkopf field trial. Pursuing an ambitious research strategy that integrates experimental and applied research, the QL movement will have the chance to show that it is not merely l'art pour l'art, but indeed is beneficial to society. Received: 28 September 1998 / Accepted: 14 October 1998  相似文献   
110.
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