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   7218篇
  免费   334篇
  国内免费   28篇
耳鼻咽喉   113篇
儿科学   149篇
妇产科学   142篇
基础医学   787篇
口腔科学   259篇
临床医学   462篇
内科学   1970篇
皮肤病学   193篇
神经病学   478篇
特种医学   167篇
外科学   1280篇
综合类   29篇
预防医学   542篇
眼科学   149篇
药学   320篇
中国医学   17篇
肿瘤学   523篇
  2023年   35篇
  2022年   79篇
  2021年   213篇
  2020年   105篇
  2019年   168篇
  2018年   264篇
  2017年   132篇
  2016年   169篇
  2015年   167篇
  2014年   272篇
  2013年   307篇
  2012年   533篇
  2011年   501篇
  2010年   306篇
  2009年   310篇
  2008年   464篇
  2007年   503篇
  2006年   452篇
  2005年   462篇
  2004年   386篇
  2003年   358篇
  2002年   341篇
  2001年   114篇
  2000年   153篇
  1999年   154篇
  1998年   56篇
  1997年   41篇
  1996年   46篇
  1995年   32篇
  1994年   28篇
  1993年   23篇
  1992年   51篇
  1991年   56篇
  1990年   35篇
  1989年   34篇
  1988年   21篇
  1987年   25篇
  1986年   23篇
  1985年   16篇
  1984年   11篇
  1983年   11篇
  1982年   9篇
  1981年   20篇
  1980年   9篇
  1979年   13篇
  1977年   9篇
  1976年   11篇
  1975年   6篇
  1971年   7篇
  1944年   4篇
排序方式: 共有7580条查询结果,搜索用时 0 毫秒
71.

Introduction

Vitamin D insufficiency (VDI) has been associated with increased cardiovascular risk in the non-HIV population. This study evaluates the relationship among serum 25-hydroxyvitamin D [25(OH)D] levels, cardiovascular risk factors, adipokines, antiviral therapy (ART) and subclinical atherosclerosis in HIV-infected males.

Methods

A cross-sectional study in ambulatory care was made in non-diabetic patients living with HIV. VDI was defined as 25(OH)D serum levels <75 nmol/L. Fasting lipids, glucose, inflammatory markers (tumour necrosis factor-α, interleukin-6, high-sensitivity C-reactive protein) and endothelial markers (plasminogen activator inhibitor-1, or PAI-I) were measured. The common carotid artery intima-media thickness (C-IMT) was determined. A multivariate logistic regression analysis was made to identify factors associated with the presence of VDI, while multivariate linear regression analysis was used to identify factors associated with common C-IMT.

Results

Eighty-nine patients were included (age 42±8 years), 18.9% were in CDC (US Centers for Disease Control and Prevention) stage C and 75 were on ART. VDI was associated with ART exposure, sedentary lifestyle, higher triglycerides levels and PAI-I. In univariate analysis, VDI was associated with greater common C-IMT. The multivariate linear regression model, adjusted by confounding factors, revealed an independent association between common C-IMT and patient age, time of exposure to protease inhibitors (PIs) and impaired fasting glucose (IFG). In contrast, there were no independent associations between common C-IMT and VDI or inflammatory and endothelial markers.

Conclusions

VDI was not independently associated with subclinical atherosclerosis in non-diabetic males living with HIV. Older age, a longer exposure to PIs, and IFG were independent factors associated with common C-IMT in this population.  相似文献   
72.

Objectives

To assess the management of gallbladder cancer (GBC) in our region.

Material and methods

Data on 372 patients who underwent cholecystectomy were identified from our database (January 2003 to February 2008) and 6 patients were found to have GBC.

Results

Four patients had incidental carcinoma, one case was preoperatively suspected, and one patient presented with jaundice and locally advanced neoplasia. The incidence was 2 per 100,000 inhabitants per year; incidental carcinoma in 1.1% of cholecystecomies. The ultrasonography showed multilithiasis in 2 patients, sludge and neoplasia in 1, gallstones more than 3 cm in 2, and tumor mass only in 1 case. T stage: 1 case of T0 (in situ), 1 of T1, 2 of T2 and one T4. Incidental carcinomas were reoperated on when a T2 was established: 2 underwent lymphadenectomy and cystic stump resection, 1 segmentectomy IVb-V and lymphadenectomy. In the preoperative suspected neoplasia a cholecystectomy, lymphadenectomy, and partial hepatic gallbladder bed resection was initially performed.

Conclusions

GBC has a low incidence but it will be found in 1% of cholecystectomies. There is no adjuvant treatment and T-based surgical treatment is the is the only opportunity to reach cure in those patients. A national GBC database would be helpful in the publication of national guidelines for this disease.  相似文献   
73.
IntroductionThe treatment used after failure of at least two lines of antiretroviral treatment in HIV patients is called salvage therapy. The study aims to describe the characteristics of HIV patients subjected to such a regimen, and determine the safety and effectiveness of treatment with tipranavir (TPV), darunavir (DRV), enfuvirtide (ENF) and etravirine (ETR) combined with an optimised antiretroviral regimen.Patients and methodsHIV patients treated with ENF, TPV, DRV or ETR in a tertiary hospital infectious diseases department subjected to at least 12 weeks treatment. The patient characteristics are described and the effectiveness, durability and adherence to the treatment analysed.ResultsThere were 28 patients studied, with an average of 10 treatment regimens prior to starting salvage therapy (SD = 3.5; 95 % CI, 8.9-11.1). A total of 85.7 % patients had treatment adherence > 90 %. For ENF, 70.8 % of the treatment lines were suspended during follow-up. After salvage therapy, the percentage of patients with viral load (VL) < 400 copies/ml doubled, and cases with undetectable CV (< 50 copies/ml) almost tripled. The treatments used did not change the liver or kidney profiles; however, they changed the lipid profile and increased the percentage of patients with hyperglycaemia.ConclusionsThe salvage therapy studied was effective. Good adherence to the therapy is critical for its effectiveness.  相似文献   
74.
There are multiple causes of hepatitis. The most frequent etiologies are viral, usually hepatitis A, B and C viruses. However, other, non-hepatotropic viruses can cause this disease, including parvovirus B19. We present a case of acute hepatitis due to parvovirus B19, as well as a review of the epidemiological, clinical, diagnostic and therapeutic features of this entity.  相似文献   
75.
76.
ObjectiveTo describe the use of the Internet by primary care patients to seek health related information, understand how they are influenced by this information, and evaluate its impact on the doctor-patient relationship.DesignCross sectional study, through self-administered survey.SettingOne urban health center in Madrid.ParticipantsA total of 323 questionnaires were collected from patients between 14 and 75 years old who attended a physician's office for any reason, excluding illiterate patients and those with neurological or psychiatric problems preventing them from completing the survey.MeasurementsInternet usage, ability of the internet to clarify doubts regarding health issues, patient lifestyle changes, socio-demographic variables, and physician's receptivity to the use of internet by patients.Results61% (CI 95%: 56%-67%) of patients used the Internet as a source of health information: Internet queries were able to address health doubts in 92.4% of users, 53.5% reported that the Internet changed their thinking about their health in at least one instance, 30% made behavioral changes (of which 60.1% discussed these changes with their physician), 44.3% had more questions at the physician's office, and 80.8% believe that the doctor would be willing to talk about the information found on the internet.ConclusionsUsing the Internet to find information about health is very common, with positive influence on physician-patient relationship. This may be useful for achieving behavioral changes in patients and can be used as a tool in medical practice.  相似文献   
77.
ObjectivesTo evaluate the effects of dietary restriction on oxidative status, the HuC/D–neuronal nitric oxide synthase (nNOS) myenteric neuron population, HuC/D-S100 glial cells, and the morphometry of the small intestine in rats at various ages.MethodsFifteen Wistar rats were divided into 7-and 12-mo-old control groups and a 12-mo-old experimental group subjected to dietary restrictions (50% of normal ration) for 5 mo. At 7 and 12 mo of age, the animals were anesthetized, and blood was collected to assess the biochemical components and oxidative status. Ileum samples were subjected to double-marker (HuC/D-nNOS and HuC/D-S100) immunostaining and histologic processing to morphometrically analyze intestinal wall elements and determine the metaphase index and rate of caliciform cells. The data were subjected to analysis of variance and the Tukey post hoc test with a 5% significance level.ResultsAge affected the oxidative status by increasing lipid peroxidation, with no effect on blood components, intrinsic innervation, and intestinal wall elements. The animals subjected to dietary restriction showed improved levels of total cholesterol, triacylglycerols, and oxidative status, with no changes in the nNOS neuron population. However, the dietary restriction dramatically decreased the glial and HuC/D myenteric populations, led to atrophy of the neuronal cell body, induced glial hypertrophy, and decreased the thickness of the intestinal wall.ConclusionThe high oxidative status of the aging animals was reversed by dietary restriction, which also lowered cholesterol and triacylglycerol levels. The present dietary restriction elicited morpho-quantitative changes in the myenteric plexus and histology of the ileum, with likely effects on intestinal functions.  相似文献   
78.
This article summarizes the main developments reported during the year 2012 concerning ischemic heart disease, together with the most relevant innovations in the management of acute cardiac patients.  相似文献   
79.
During 2003–2012, 8 clusters of meningococcal disease were identified in Rio de Janeiro State, Brazil, all caused by serogroup C Neisseria meningitidis. The isolates were assigned to 3 clonal complexes (cc): cc11, cc32, and cc103. These hyperinvasive disease lineages were associated with endemic disease, outbreaks, and high case-fatality rates.  相似文献   
80.
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