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   764篇
  免费   53篇
  国内免费   1篇
耳鼻咽喉   3篇
儿科学   44篇
妇产科学   48篇
基础医学   77篇
口腔科学   18篇
临床医学   75篇
内科学   120篇
皮肤病学   31篇
神经病学   57篇
特种医学   16篇
外国民族医学   4篇
外科学   59篇
综合类   11篇
预防医学   65篇
眼科学   30篇
药学   77篇
中国医学   9篇
肿瘤学   74篇
  2024年   1篇
  2023年   9篇
  2022年   14篇
  2021年   30篇
  2020年   24篇
  2019年   38篇
  2018年   44篇
  2017年   29篇
  2016年   41篇
  2015年   36篇
  2014年   36篇
  2013年   61篇
  2012年   83篇
  2011年   78篇
  2010年   37篇
  2009年   16篇
  2008年   47篇
  2007年   30篇
  2006年   45篇
  2005年   33篇
  2004年   29篇
  2003年   21篇
  2002年   18篇
  2001年   4篇
  2000年   1篇
  1999年   3篇
  1998年   2篇
  1997年   3篇
  1996年   1篇
  1994年   1篇
  1993年   2篇
  1989年   1篇
排序方式: 共有818条查询结果,搜索用时 0 毫秒
81.
AIM: To investigate the prevalence and risk factors of gastroesophageal reflux disease (GERD) symptoms in Qashqai migrating nomads with a different life style in Fars province, southern Iran. METHODS: In summer 2006, 748 Qashqai migrating nomads aged 25 years or more were enrolled using a multiple-stage stratified cluster random sampling method. A questionnaire consisting of demographic characteristics, lifestyle and GERD symptoms (heartburn, regurgitation, chest pain, dysphagia, hoarseness and cough) as completed for each subject. RESULTS: The questionnaire was completed in 717 subjects. The prevalence rate of GERD, defined as reflux occurring at least one time per week in the preceding year, was 33% (237 subjects). The prevalence was higher in older individuals (36.0% vs 28.9%, P 〈 0.05) and in those with other gastrointestinal complaints (51.0% vs 27.8%, P 〈 0.001), but not different in obese and non-obese subjects. It was also higher in those consuming fruits and vegetables more than once a week (36.2% vs 17.3%, P 〈 0.001). GERD had a positive correlation with smoking (42.1% vs 27.8%, P 〈 0.001), but a negative relation with non-alcoholic beverages. The association between GERD and non-steroidal antiinflammatory drugs (NSAIDs) consumption was also significant (40.2% vs 25.4%, P 〈 0.001). CONCLUSION: The prevalence of GERD (33%) is very high in Qashqai migrating nomads which may be due to a lower socioeconomic and educational level of these people and difference in the life style. Older age, frequent consumption of fruits and vegetables, smoking and NSAIDs are risk factors for GERD in this population.  相似文献   
82.
A distinct set of mutations on the β-globin gene leads to dominantly inherited β-thalassemia (β-thal) that is associated with a disease phenotype in a single mutant copy. We described molecular and hematological characteristics of a novel elongated β-globin chain in combination with a known hemoglobin (Hb) variant (N-Baltimore or HBB: c.286A>G) in cis. The highly unstable Hb variant caused typical features of β-thal major (β-TM) or β-thal intermedia (β-TI) in two members of a family depending on their α-globin genotypes. The β mutant allele of the mother was transmitted in an autosomal dominant fashion to her daughter. They resemble severe forms of β-thal due to ineffective erythropoiesis. Taken together with previously published data, this result indicates that a dominant form of β-thal should be regarded as a phenotypic term of hemoglobinopathies caused by β chain variants that are highly unstable.  相似文献   
83.
OBJECTIVE: To determine the frequency and clinical characteristics of osteoarticular complications of brucellosis in an endemic region in Iran. METHODS: In a prospective study we evaluated 245 patients with brucellosis diagnosed between January 2004 and December 2005. Patients included were those older than 8 years of age and who had clinical features suggestive of brucellosis and specific antibodies at significant titers, and/or positive blood or body fluid culture for Brucella species. A bone scan was performed in those with a clinical suspicion of osteoarticular involvement. RESULTS: Seventy patients (28.6%) had osteoarticular complications. Sacroiliitis was the most common complication (75.7%), followed by spondylitis (21.4%) and peripheral arthritis (8.6%). Spondylitis was the most common osteoarticular complication in the elderly. Relapses occurred in five (2%) patients, three of them with spondylitis. CONCLUSIONS: Osteoarticular disease is the most common complication of brucellosis in Western Iran. Sacroiliitis is the most common form of osteoarticular complication. With the use of a proper treatment regimen, the prospect for recovery is good.  相似文献   
84.
Metabolic syndrome is a set of cardiovascular risk factors that increase the risk of cardiovascular disease, diabetes and mortality. Women are at risk of developing metabolic syndrome as they enter the postmenopausal period. The present systematic review and meta-analysis was conducted to estimate the prevalence of metabolic syndrome in Iranian postmenopausal women. In this systematic review and meta-analysis, 16 national articles published in Persian and English were gathered without time limit. National databases such as SIDs, IranMedex and MagIran, and international databases such as Web of Science, Google Scholar, PubMed and Scopus were used to search the relevant studies. We searched for articles using the keywords “menopause”, “postmenopausal”, “metabolic syndrome”, “MetSyn”, and their combinations. Data were analyzed using the meta-analysis method and the random effects model. Analysis of 16 selected articles with a sample size of 5893 people showed that the prevalence of metabolic syndrome in Iranian postmenopausal women was 51.6% (95% CI: 43–60). The prevalence of metabolic syndrome based on ATP III and IDF criteria was 54% (95% CI: 59–63) and 50% (95% CI: 45–56), respectively. Based on the results of univariate meta-regression analysis, the increase in the mean age of postmenopausal women (p?=?0.001) and sample size (p?=?0.029), the prevalence of metabolic syndrome increased significantly. More than half of postmenopausal women in Iran suffer from metabolic syndrome. Providing training programs for postmenopausal women to prevent and control cardiovascular disease and its complications seems to be necessary.  相似文献   
85.
The prothrombin time (PT) represents the most commonly used coagulation test in clinical laboratories. The PT is mathematically converted to the international normalized ratio (INR) for use in monitoring anticoagulant therapy with vitamin K antagonists such as warfarin in order to provide test results that are adjusted for thromboplastin and instrument used. The INR is created using two major PT ‘correction factors’, namely the mean normal PT (MNPT) and the international sensitivity index (ISI). Manufacturers of reagents and coagulometers have made some efforts to harmonizing INRs, for example, by tailoring reagents to specific coagulometers and provide associated ISI values. Thus, two types of ISIs may be generated, with one being a ‘general’ or ‘generic’ ISI and others being reagent/coagulometer-specific ISI values. Although these play a crucial role in improving INR results between laboratories, these laboratories reported INR values are known to still differ, even when laboratories use the same thromboplastin reagent and coagulometer. Moreover, ISI values for a specific thromboplastin can vary among different models of coagulometers from a manufacturer using the same method for clot identification. All these factors can be sources of error for INR reporting, which in turn can significantly affect patient management. In this narrative review, we provide some guidance to appropriate ISI verification/validation, which may help decrease the variability in cross laboratory reporting of INRs.  相似文献   
86.
In December 2019, a new type of coronavirus was detected for the first time in Wuhan, Hubei Province, China. According to the reported data, the emerging coronavirus has spread worldwide, infecting more than fifty-seven million individuals, leading to more than one million deaths. The current study aimed to review and discuss the hematological findings of COVID-19. Laboratory changes and hematologic abnormalities have been reported repeatedly in COVID-19 patients. WBC count and peripheral blood lymphocytes are normal or slightly reduced while these indicators may change with the progression of the disease. In addition, several studies demonstrated that decreased hemoglobin levels in COVID-19 patients were associated with the severity of the disease. Moreover, thrombocytopenia, which is reported in 5%-40% of patients, is known to be associated with poor prognosis of the disease. COVID-19 can present with various hematologic manifestations. In this regard, accurate evaluation of laboratory indicators at the beginning and during COVID-19 can help physicians to adjust appropriate treatment and provide special and prompt care for those in need.  相似文献   
87.
Aim: To examine the utility of the Cornell scale for depression in dementia (CSDD), following its introduction as a routine measure in nursing homes. Methods: The CSDD is administered in Australian nursing homes as section 10 of the Aged Care Funding Instrument. CSDD, cognitive and behavioural ratings, and medication use, recorded in three Sydney nursing homes in 2008–2009 were reviewed. Staff discussed what actions were taken if CSDD scores indicated depression. Results: Of 223 residents, 23% scored >12 on the CSDD, indicating probable depression. Another 21% were possibly depressed and 29% not depressed. The CSDD had not been completed for 27%, commonly because preliminary screening indicated no depression, but sometimes because severe cognitive impairment made various CSDD items impossible to rate. Second CSDD assessments had usually not been made. Conclusion: Nursing homes need to document policies that will ensure best use is made of CSDD findings.  相似文献   
88.

Background

Early recognition and accurate risk stratification are important in the management of arrhythmogenic right ventricular cardiomyopathy (ARVC). Identification of predictors of outcome by cardiovascular magnetic resonance (CMR) in patients undergoing evaluation for ARVC is limited. We investigated the predictive value of morphological abnormalities detected by CMR for major clinical events in patients with suspected ARVC.

Methods

We performed a longitudinal study on 369 consecutive patients with at least one criterion for ARVC. Abnormal CMR was defined by the presence of one of the following: increased right ventricular (RV) volumes, reduced RV ejection fraction, RV regional wall motion abnormalities, myocardial fatty infiltration, and myocardial fibrosis. The end-point was a composite of cardiac death, sustained ventricular tachycardia, ventricular fibrillation, and appropriate ICD discharge.

Results

Twenty patients met the composite end-point over a mean follow-up of 4.3 ± 1.5 years. An abnormal CMR was an independent predictor of outcomes (p < 0.001). The presence of multiple abnormalities heralded a particular high risk of events (HR 23.0, 95% CI 5.7–93.2, p < 0.001 for 2 abnormalities; HR 35.8, 95% CI 9.7–132.6, p < 0.001 for 3 or more abnormalities). The positive predictive value of an abnormal CMR study was 21.0% for an adverse event, whilst the negative predictive value of a normal CMR study was 98.8% over the follow-up period.

Conclusions

CMR provides important prognostic information in patients under evaluation for ARVC. A normal study portends a good prognosis. Conversely, the presence of multiple abnormalities identifies a high risk group of patients who may benefit from ICD implantation.  相似文献   
89.
Navid F  Mischen BT  Helman LJ 《Sarcoma》2004,8(1):25-30
Purpose. Transduction of rhabdomyosarcoma (RMS) cells with adenoviral vectors for in vivo and in vitro applications has been limited by the low to absent levels of coxackie and adenovirus receptor (CAR). This study investigates the potential use of low doses of a histone deacetylase inhibitor, depsipeptide (FR901228), currently in Phase II human trials, to enhance adenoviral uptake in six rhabdomyosarcoma cell lines.Methods. Differences in adenoviral uptake in the presence and absence of depsipeptide (FR901228) were assessed using an adenoviral construct tagged with green fluorescent protein. Changes in CAR and alpha(v) integrin expression RMS in response to pretreatment with depsipeptide (FR901128) was determined using RT-PCR.Results. Pretreatment of five of six RMS cell lines with 0.5 ng/ml of depsipeptide (FR901228) for 72 h resulted in increased viral uptake as assessed by green fluorescent protein expression. RT-PCR analysis for CAR showed that in four of these five cell lines, CAR expression was increased 2.8-8.1-fold in cells treated with depsipeptide (FR901228) as compared to control. alpha(v) integrin expression was substantially increased in the one cell line, RH5, which showed increased GFP expression in response to depsipeptide (FR901228) pretreatment but a minimal increase in CAR expression.Conclusions. Depsipeptide (FR901228) can be used as a vehicle to enhance adenoviral transduction in a majority of RMS cells. The mechanism of increased viral uptake appears to mediate via upregulation of CAR.  相似文献   
90.
INTRODUCTION: Despite long standing iodine supplementation in Iran the prevalence of goiter remains high in some areas. This may suggest that causes other than iodine deficiency, such as autoimmune thyroid diseases, should also be considered. We therefore assessed the prevalence of anti-thyroid antibodies in children living in an inland area in Iran and correlated these findings with prevalence of goiter within this region. METHODS: In a cross-sectional study, 1948 students were selected by multistage random cluster sampling from the 108 primary schools (age, 7-13 year-old) of the urban and rural areas of Semirom. After obtaining written consent from their parents, the children were examined by endocrinologists for goiter grading. Grade 2 goitrous children (108 cases) were compared with non-goitrous children (111 children as control group) for anti-thyroid antibodies. RESULTS: Overall, 36.7% of 1948 students had goiter. The mean urinary iodine excretion level was 1.49+/-0.7 micromol/L. This was within normal limits. Of 219 children studied, 4.3% presented with subclinical hypothyroidism, and 7.3% had positive anti-thyroid antibodies. There was non-significant difference of positive thyroperoxidase antibody (anti-TPO) (Odds Ratio= 3.2, p= 0.13) but significant difference of anti Tg between goitrous and non goitrous children (Odds Ratio: 5.6, 95% CI: 1.18-26.0, p: 0.015). CONCLUSION: This study suggests that autoimmunity may be one of the mechanisms responsible for goiter persistence after iodine replenishment in this iodine deficient region, but the role of other factors should also be considered.  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