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   15555篇
  免费   1081篇
  国内免费   47篇
耳鼻咽喉   159篇
儿科学   350篇
妇产科学   245篇
基础医学   2196篇
口腔科学   337篇
临床医学   2128篇
内科学   3309篇
皮肤病学   172篇
神经病学   1268篇
特种医学   617篇
外国民族医学   2篇
外科学   2024篇
综合类   125篇
一般理论   9篇
预防医学   1312篇
眼科学   240篇
药学   1136篇
中国医学   15篇
肿瘤学   1039篇
  2023年   93篇
  2022年   165篇
  2021年   276篇
  2020年   204篇
  2019年   339篇
  2018年   373篇
  2017年   285篇
  2016年   325篇
  2015年   374篇
  2014年   523篇
  2013年   764篇
  2012年   1173篇
  2011年   1185篇
  2010年   687篇
  2009年   622篇
  2008年   930篇
  2007年   1046篇
  2006年   957篇
  2005年   963篇
  2004年   810篇
  2003年   709篇
  2002年   735篇
  2001年   178篇
  2000年   158篇
  1999年   178篇
  1998年   180篇
  1997年   155篇
  1996年   137篇
  1995年   129篇
  1994年   116篇
  1993年   96篇
  1992年   117篇
  1991年   114篇
  1990年   98篇
  1989年   98篇
  1988年   94篇
  1987年   68篇
  1986年   62篇
  1985年   80篇
  1984年   85篇
  1983年   90篇
  1982年   69篇
  1981年   51篇
  1980年   67篇
  1979年   71篇
  1978年   51篇
  1977年   51篇
  1976年   52篇
  1975年   53篇
  1972年   48篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
To estimate the evolution of amyloid in tissue, we studied abdominal fat aspirates of cases with familial amyloidotic polyneuropathy (FAP) longitudinally at regular intervals between 1994 and 2006. In 22 cases (13 carriers and nine patients) not yet transplanted median follow-up was 3.3 years (range 0.4-11.3). We found a significant increase in the amyloid grade of fat tissue from 2+ to 4+ and from 0 to 4+ in two of three subjects with follow-ups of >7 years, after 7 and 11 years, respectively. All other subjects remained negative or did not show a significant change. In 11 liver transplant patients, follow-up with fat aspirate was available with a median duration of 3.1 years (range 1.0-10.1). A comparison was made with cardiac amyloid as judged by the cardiac septum diameter and the serum NT-ProBNP (N-terminal pro-B-type natriuretic peptide) level. No stable increase of amyloid in fat was seen in any patient. A stable decrease of amyloid grade was seen in one patient 5 years after transplantation. In contrast, the cardiac septum diameter increased >or=4 mm in six of the 11 transplant patients. Our study shows the diagnostic utility of a regularly repeated fat aspirate in carriers at risk for the development of ATTR amyloidosis. Evolution of amyloid deposition in fat tissue is very gradual. After liver transplantation, amyloid deposition in fat tissue seems to stabilize and may even decrease in the long term, whereas amyloid deposition in cardiac tissue appears to be progressive.  相似文献   
32.
33.
INTRODUCTION: One-third of children with epilepsy are classified as having a cryptogenic localization related epilepsy (CLRE). In cohort studies CLRE is often grouped together with either symptomatic localization related epilepsy (SLRE) or idiopathic generalized epilepsy (IGE). Therefore, this categorization is not specific enough and will not lead to prognostic or treatment information. We objectified the classification differences between these categories. METHODS: A total of 114 children admitted to our epilepsy centre underwent a standardized clinical analysis, which yielded age at onset, duration of the epilepsy, seizure frequency, seizure type, percentage of interictal epileptiform activity on EEG (IEA), type of treatment, and full scale IQ. These variables are regarded the characteristics of the epilepsy, and used in a discriminant function analysis. RESULTS: IEA was found to be the only variable to distinguish between groups of epilepsy. SLRE could easily be distinguished significantly from IGE and CLRE, while the latter two did not differ significantly. Discriminant function analysis combined the variables into two functions, applicable to classify the children. By applying this statistical analysis method, the groups clinically classified as SLRE and IGE were mostly classified as SLRE (71.4%) and IGE (57.9%). However, CLRE appeared difficult to classify (49.2%), and most children were classified as either SLRE (19%) or IGE (31.7%). CONCLUSION: The current opinion that CLRE is 'probably symptomatic' cannot be confirmed in all cases in this study. It is most likely that the current CLRE population consists of both children with eventually SLRE, as well as yet to be described syndromes to be classified as idiopathic epilepsies. We emphasize the need for separate studies regarding children with 'probably symptomatic' (cryptogenic) localization related epilepsy, as this will maximally help children, caretakers and treating physicians to achieve the best possible outcome.  相似文献   
34.
35.
36.
Introduction: Sarcoidosis is a granulomatous disorder of unknown aetiology, affecting young adults and frequently involving the lungs. Objective: The aim of the present review was to give an overview of the clinical aspects in sarcoidosis. Results: The majority of patients recover, but some develop a chronic disease that may result in fibrosis and respiratory failure. Besides the lungs, peripheral lymph nodes, the skin, the liver and the eyes are commonly affected as well. The genetic background, as well as environmental factors, is of importance for developing sarcoidosis. The incidence varies in different populations, in the Nordic countries approximately with 20/100 000 new patients yearly. Sarcoidosis is diagnosed when clinical and radiological findings are supported by histological evidence in the form of non‐caseating epithelioid cell granulomas, and when other causes of these features are excluded. Patients in need of treatment are usually treated with corticosteroids, topically or as oral steroids. A clinical effect of immunomodulatory drugs blocking tumour necrosis factor (TNF)α has been suggested from several case reports, while two controlled studies showed only minor effects; however, with a tendency to a more pronounced effect on patients with a more severe disease. The immune response in sarcoidosis, with a typical accumulation of CD4+ T‐cells to the lungs, indicate the existence of specific antigens in this disease. Recently, antigens derived from infectious agents such as Mycobacteria and Proprionibacterium acnes have come into focus. Lymphocyte populations with immunoregulatory functions have recently been investigated and seem to be dysfunctional in sarcoidosis, opening the possibility of developing new treatment strategies in this disease. Conclusion: Recent technical developments have provided better tools, enabling detailed and more thorough analyses of the inflammatory process in sarcoidosis. Please cite this paper as: Grunewald J. Clinical aspects and immune reactions in sarcoidosis. The Clinical Respiratory Journal 2007; 1:64–73.  相似文献   
37.
Assessment of autonomic dysfunction in Parkinson's disease: the SCOPA-AUT.   总被引:2,自引:0,他引:2  
We developed a questionnaire to assess autonomic symptoms in patients with Parkinson's disease (PD) and evaluated its reliability and validity. Based on the results of a postal survey in 46 PD patients, 21 multiple system atrophy patients, and 8 movement disorders specialists, items were included according to their frequency, burden, and clinical relevance. The questionnaire was evaluated in 140 PD patients and 100 controls, and test-retest reliability was established in a sample of 55 PD patients. The SCOPA-AUT consists of 25 items assessing the following regions: gastrointestinal (7), urinary (6), cardiovascular (3), thermoregulatory (4), pupillomotor (1), and sexual (2 items for men and 2 items for women) dysfunction. Test-retest reliability was good. Autonomic problems increased significantly with increasing disease severity for all autonomic regions, except sexual dysfunction. We conclude that SCOPA-AUT is a reliable and valid questionnaire that evaluates autonomic dysfunction in PD.  相似文献   
38.
This article examines recent developments in the role of general hospitals in providing treatment for alcoholism. It employs data on 5,000 U.S. short-term general hospitals and on all patients discharged from a subsample of 400 of these hospitals in the years 1980 through 1985. The article describes the growth in alcoholism treatment resources in short-term hospitals (1980-85) and examines linked hospital and patient data for the 400 hospitals in the subsample to describe patient diagnoses and resource use (1980 and 1985). Patients are classified by the stage of their alcohol problem, and hospital use is examined for patients in different stages.  相似文献   
39.
Heavy-resistance exercise utilizing very short rest periods is commonly used by body builders to prepare for competition. The purpose of this study was to compare the acute responses of this type of heavy-resistance exercise protocol in competitive body builders (BB) and power lifters (PL). Nine male BB and eight PL were matched for age, size and experience. A ten-station heavy-resistance exercise protocol was used. Each subject performed three sets of 10 repetition maximum (RM) with 10-s rest between sets and alternated 30-s and 60-s rest periods between exercises. No differences were observed in total work between the groups, but BB used a significantly (P less than 0.05) higher percentage of their 1 RM in the bench press and leg press exercises. Heart rate, ratings of perceived exertion (RPE), and lactate levels were obtained during the exercise protocol; significant (P less than 0.05) increases were observed above rest for these variables. RPE was significantly correlated with lactate levels (r = 0.84). Plasma epinephrine, norepinephrine, dopamine, cortisol, and lactate levels significantly increased from pre- to 5 min post-exercise. Mean plasma volumes were reduced -16.6 (+/- 3.64)% and -20.6 (+/- 8.32)% following the exercise protocol for BB and PL, respectively. Significant (P less than 0.05) decreases in eosinophil counts were observed following exercise. No significant differences were observed between BB and PL for any of the physiologic responses measured. PL exhibited a higher incidence (100%) of clinical symptoms of dizziness and nausea compared to BB (11.1%).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
40.
Encephalitozoon cuniculi, a microsporidian parasite of vertebrates, is considered a health risk to AIDS patients and other immunocompromised human beings. In most hosts, infection with the parasite runs a subclinical course. In some carnivore species, however, clinical disease affecting whole litters arises from intrauterine transmission of the parasite. In both blue foxes (Alopex lagpus) and dogs (Canis familiaris), outbreaks of encephalitozoonosis can be severe. Canine encephalitooonosis has been reported from various parts of the world, including South Africa and the United States. In Norway, there have been large outbreaks of the disease in blue fox farms, affecting also mink, but there have been no reports of encephalitozoonosis in dogs. Infection in dogs would represent a zoonotic problem, due to the close social relationship between dog and man. The purpose of the present study was to investigate the possible occurrence of E. cuniculi infection in Norwegian dogs by serological methods. In the study, 1,104 canine serum samples, originally submitted for biochemical analysis by veterinary practitioners throughout Norway, were screened by enzyme-linked immunosorbent assay for antibodies to E. cuniculi. Samples from 237 of the dogs were tested also by the indirect fluorescent antibody test. All samples were concluded as negative. The results indicate that the likelihood of occurrence of E. cuniculi infection in Norwegian dogs is small.  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