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   2905582篇
  免费   239379篇
  国内免费   12894篇
耳鼻咽喉   39755篇
儿科学   91668篇
妇产科学   72385篇
基础医学   479517篇
口腔科学   75707篇
临床医学   263482篇
内科学   494812篇
皮肤病学   82992篇
神经病学   246981篇
特种医学   114501篇
外国民族医学   79篇
外科学   458212篇
综合类   87959篇
现状与发展   23篇
一般理论   2081篇
预防医学   247264篇
眼科学   65926篇
药学   194681篇
  22篇
中国医学   8614篇
肿瘤学   131194篇
  2022年   22764篇
  2021年   54554篇
  2020年   34754篇
  2019年   57681篇
  2018年   70172篇
  2017年   53304篇
  2016年   58528篇
  2015年   73104篇
  2014年   107091篇
  2013年   172079篇
  2012年   76858篇
  2011年   75851篇
  2010年   113168篇
  2009年   117951篇
  2008年   62362篇
  2007年   64168篇
  2006年   74975篇
  2005年   70765篇
  2004年   72875篇
  2003年   64275篇
  2002年   54398篇
  2001年   72191篇
  2000年   63723篇
  1999年   69918篇
  1998年   61749篇
  1997年   60275篇
  1996年   57960篇
  1995年   53460篇
  1994年   47480篇
  1993年   44552篇
  1992年   46697篇
  1991年   45947篇
  1990年   43572篇
  1989年   43773篇
  1988年   40624篇
  1987年   39802篇
  1986年   37660篇
  1985年   38642篇
  1984年   38315篇
  1983年   35966篇
  1982年   37852篇
  1981年   36075篇
  1980年   34170篇
  1979年   30559篇
  1978年   29352篇
  1977年   27203篇
  1976年   25372篇
  1975年   24389篇
  1974年   23730篇
  1973年   22698篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
THE BASIC SCIENCE OF PSYCHOLOGY HAS IDENTIFIED specific ingrained responses that are fundamental elements of human nature, underpin common influence strategies and may apply in medical settings. People feel a sense of obligation to repay a perceived debt. A request becomes more attractive when preceded by a marginally worse request. The drive to act consistently will persist even if demands escalate. Peer pressure is intense when people face uncertainty. The image of the requester influences the attractiveness of a request. Authorities have power beyond their expertise. Opportunities appear more valuable when they appear less available. These 7 responses were discovered decades ago in psychology research and seem intuitively understood in the business world, but they are rarely discussed in medical texts. An awareness of these principles can provide a framework for physicians to help patients change their behaviour and to understand how others in society sometime alter patients' choices.  相似文献   
993.
994.
Zusammenfassung Anhand von 678 bis Ende 1979 operierten Patienten mit Lungenerkrankungen wird die technische Anwendung automatischer Nahtgeräte demonstriert. Sie eignen sich zum Bronehusverschluß, für Keilexcisionen sowie zum Verschluß von Lungenvenen. Technische Modalitäten sind zu beachten. Der Vorteil liegt bei sachgemäßem Vorgehen in der Sicherheit der Anwendung, der Effektivität und in der kürzeren Operationszeit. Die Insuffizienzquote beträgt einschl. der Anfangszeit 4,4% in der Spätphase 3,2%. Komplikationen bei Keilexcisionen treten ebensowenig auf wie beim Verschluß der Lungenvenen.  相似文献   
995.
A consecutive series of patients (1978–1981) comprising all patients with acute leukaemia from a population of 475000 inhabitants was reviewed. Thus, 94 patients were diagnosed as having acute leukaemia. No patients were lost from follow-up. The incidence figures of ALL and AML differed significantly from those of Sweden as a whole. 9 patients were < 15 years old. The median age of adult patients was 64 years, 60.8% being ≥ 60 years old. Of adult patients with AML, 20% had a preleukaemic history (chronic myeloproliferative disorders, myelodysplastic syndromes and others). None of 6 patients with leukaemia as a metamorphosis of a chronic myeloproliferative disorder achieved a complete remission. The overall remission rate of the remaining adult patients was 25%. Treated patients, 15–39 years old, with AML without any preleukaemic history, had a complete remission rate of 80% compared to 12% for patients ≥ 60 years old with the same diagnosis. Of 60 patients with ‘primary’ AML, 14 were not treated, mainly because of advanced age and complicating diseases. Most of these patients died within a week of admission.  相似文献   
996.
A rare case of an advanced primary broad ligament carcinoma is discussed, with a review of the literature regarding its incidence, presentation and management. This patient showed a complete response to adjuvant cisplatin-based chemotherapy following panhysterectomy and is presently without any evidence of disease, 15 months after completion of her treatment.  相似文献   
997.
998.
We introduce the concept of the metabolic centroid spectrum as the feature space to characterize the distribution of metabolic activity in three-dimensional brains. The method computes the metabolic centroid of a brain subvolume for each increment of metabolic activity occurring in the whole brain. The result is the metabolic spectral signature, a continuous three-dimensional curve whose shape reflects the distribution of metabolic rates in the brain. The method's sensitivity to metabolic distribution asymmetries is greatly increased over that of the metabolic centroid method, while retaining its advantages; it is almost invariant to head size, head positioning, photon scatter, and the positron emission tomography (PET) camera's full width at half-maximum. It does not require magnetic resonance, computed tomography, or x-ray images. To test the method we analyzed the metabolic PET images of 40 normal subjects and 20 schizophrenics. The results show a unification of several metabolic characteristics of schizophrenic brains, such as laterality, hypofrontality, cortical/subcortical abnormalities, and overall brain hypometabolism, which were identified by different laboratories in separate studies using differing methodologies. Here they are presented by a single automatic objective method.  相似文献   
999.
1. Postmortem neurochemical investigations revealed interhemispheric asymmetry in the mediofrontal region of human brain. Significantly higher right hemisphere serotonin metabolite (5HIAA) content as well as increased maximal imipramine binding (IB) were found in the right hemisphere than in the left side.

2. IB did not show a gender difference in the mediofrontal area. However, women had higher IB in the right orbital frontal cortex than did men.

3. In vivo pharmaco-EEG results tend to support the postmortem neurochemical data. Intravenous chlorimipramine resulted in an asymmetric topographic distribution of the P300 auditory evoked potential, peak amplitudes were shifted to the right hemisphere.  相似文献   

1000.
Amyloid P (AP) component is present in all types of systemic amyloid deposits. Recently, it has been shown to be also present in cerebral amyloid lesions of Alzheimer's disease (AD). In this study, we used immunocytochemical methods to extend these findings at the electron microscope level and characterize the spectrum of AP immunoreactivity in neurofibrillary pathology (NFP) of AD and other neurodegenerative disorders including Down's syndrome (DS), Creutzfeldt-Jakob, Parkinson's, Pick's and diffuse Lewy body diseases and progressive supranuclear palsy. In AD and DS, AP immunoreaction product was evident in all the classical amyloid lesions and NFP in a large sample of all cortical areas examined. The distribution and relative intensity of immunostaining was similar to that of thioflavin S staining in serial sections. In many cases, however, plaques and vessels stained by anti-AP serum were not apparent with thioflavin S. Serial sections immunostained with antiserum to amyloid A, C-reactive protein or to other proteins involved in systemic amyloidoses and the acute phase response showed no evidence of staining in any of the cerebral lesions. Electron microscopy confirmed that AP immunoreactivity was associated with the abnormal filaments characteristic of NFP as well as amyloid fibrils found in plaques and vessels showing congophilic amyloid angiopathy. Plaques of Creutzfeldt-Jakob disease, Pick bodies of Pick's disease, tangles and Lewy bodies in Parkinson's disease and a subpopulation of Lewy bodies in the diffuse Lewy body disease coexistent with AD were also stained. With the exception of vessels in two of the five cases, AP was not detected in age-matched controls. Our observations indicate AP to be a consistent feature of cerebral NFP and amyloid deposits.  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