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   5794篇
  免费   380篇
  国内免费   19篇
耳鼻咽喉   71篇
儿科学   136篇
妇产科学   259篇
基础医学   1033篇
口腔科学   57篇
临床医学   519篇
内科学   1349篇
皮肤病学   145篇
神经病学   678篇
特种医学   144篇
外科学   558篇
综合类   20篇
一般理论   1篇
预防医学   363篇
眼科学   110篇
药学   323篇
中国医学   13篇
肿瘤学   414篇
  2024年   8篇
  2023年   37篇
  2022年   120篇
  2021年   262篇
  2020年   123篇
  2019年   172篇
  2018年   198篇
  2017年   160篇
  2016年   164篇
  2015年   167篇
  2014年   243篇
  2013年   288篇
  2012年   430篇
  2011年   474篇
  2010年   293篇
  2009年   252篇
  2008年   402篇
  2007年   378篇
  2006年   358篇
  2005年   353篇
  2004年   309篇
  2003年   270篇
  2002年   222篇
  2001年   42篇
  2000年   48篇
  1999年   47篇
  1998年   32篇
  1997年   32篇
  1996年   20篇
  1995年   20篇
  1994年   22篇
  1993年   16篇
  1992年   16篇
  1991年   20篇
  1990年   13篇
  1989年   16篇
  1988年   13篇
  1987年   9篇
  1986年   10篇
  1985年   18篇
  1984年   14篇
  1983年   5篇
  1982年   7篇
  1980年   6篇
  1978年   9篇
  1975年   4篇
  1974年   5篇
  1970年   5篇
  1969年   6篇
  1930年   4篇
排序方式: 共有6193条查询结果,搜索用时 281 毫秒
71.
72.
73.
74.
75.
Defective clot contraction has been postulated to contribute to thrombosis. We aimed to evaluate the association of residual vein obstruction (RVO) with erythrocyte compression within the whole-blood clot. We studied 32 patients with venous thromboembolism (VTE) taking vitamin K antagonists (VKAs) for at least 3 months (median time in therapeutic range 60%), including 12 (37.5%) with RVO, and 32 age- and sex-matched controls. In all study participants we evaluated whole blood clot retraction, expressed as the erythrocyte compression index (ECI), defined as a ratio of mean polyhedrocyte area to mean native erythrocyte area, along with clot area covered by polyhedrocytes, plasma clot permeability (Ks), clot lysis time (CLT), and thrombin generation. In both groups higher ECI, indicating impaired clot contraction, increased with older age, higher body mass index, red blood cell distribution width, and lower platelet count (all p?<?0.05), but not with red blood cell count. In VTE patients ECI was 15.8% higher than in controls (median 63.6 vs. 54.9%, p?=?0.021). Subjects with RVO had 20% higher ECI and 155% lower clot area covered by polyhedrocytes. RVO patients had also prolonged CLT by 41%, but not Ks, and elevated peak thrombin generation by 33%, as compared to those without RVO (all p?<?0.05). This study is the first to show impaired compression of erythrocytes in RVO patients despite VKA anticoagulation. Altered ECI coexisted with hypolysability and increased thrombin generation. ECI might be useful in the diagnostic process of RVO or post-thrombotic syndrome and can help optimize the anticoagulant therapy.  相似文献   
76.
Bacterial and viral lower respiratory tract infections (LRTIs) are often clinically indistinguishable, leading to antibiotic overuse. We compared the diagnostic accuracy of a new assay that combines 3 host-biomarkers (TRAIL, IP-10, CRP) with parameters in routine use to distinguish bacterial from viral LRTIs. Study cohort included 184 potentially eligible pediatric and adult patients. Reference standard diagnosis was based on adjudication by an expert panel following comprehensive clinical and laboratory investigation (including respiratory PCRs). Experts were blinded to assay results and assay performers were blinded to reference standard outcomes. Evaluated cohort included 88 bacterial and 36 viral patients (23 did not fulfill inclusion criteria; 37 had indeterminate reference standard outcome). Assay distinguished bacterial from viral LRTI patients with sensitivity of 0.93 ± 0.06 and specificity of 0.91 ± 0.09, outperforming routine parameters, including WBC, CRP and chest x-ray signs. These findings support the assay's potential to help clinicians avoid missing bacterial LRTIs or overusing antibiotics.  相似文献   
77.
The duties performed by radiographers, which includes transferring patients onto and off the examination table, can increase their risk of developing back and neck pain. This study used a survey to identify the assistive transfer devices Australian radiography undergraduate students are familiar with and have had practise using in the clinical setting. It also sought to determine whether students are being encouraged by other radiographers to use these devices during clinical training and if they would conform to practicing unsafe transfers if instructed to by senior staff.Results indicated that radiography students were familiar with the majority of the surveyed assistive devices such as the Patslide and X-ray cassette slider. Many of the students were unlikely to participate in unsafe work practices and were able to provide alternative methods of transferring patients. However, some of the respondents could be coerced into participating in unsafe patient transfers. Radiographers should therefore be vigilant in refraining from practicing unsafe transfer techniques as it could lead to students believing it is acceptable and emulating these practices in the work place.  相似文献   
78.
ABSTRACT: BACKGROUND: For residents of long term care, hospitalisations can cause distress and disruption, and often result in further medical complications. Multi-disciplinary team interventions have been shown to improve the health of Residential Aged Care (RAC) residents, decreasing the need for acute hospitalisation, yet there are few randomised controlled trials of these complex interventions. This paper describes a randomised controlled trial of a structured multi-disciplinary team and gerontology nurse specialist (GNS) intervention aiming to reduce residents' avoidable hospitalisations. METHODS: This Aged Residential Care Healthcare Utilisation Study (ARCHUS) is a cluster- randomised controlled trial (n = 1700 residents) of a complex multi-disciplinary team intervention in long-term care facilities. Eligible facilities certified for residential care were selected from those identified as at moderate or higher risk of resident potentially avoidable hospitalisations by statistical modelling. The facilities were all located in the Auckland region, New Zealand and were stratified by District Health Board (DHB).InterventionThe intervention provided a structured GNS intervention including a baseline facility needs assessment, quality indicator benchmarking, a staff education programme and care coordination. Alongside this, three multi-disciplinary team (MDT) meetings were held involving a geriatrician, facility GP, pharmacist, GNS and senior nursing staff.OutcomesHospitalisations are recorded from routinely-collected acute admissions during the 9-month intervention period followed by a 5-month follow-up period. ICD diagnosis codes are used in a pre-specified definition of potentially reducible admissions. DISCUSSION: This randomised-controlled trial will evaluate a complex intervention to increase early identification and intervention to improve the health of residents of long term care. The results of this trial are expected in early 2013.Trial registrationAustralian New Zealand Clinical Trials Registry: ACTRN 12611000187943.  相似文献   
79.
Objective: The objective of this study is to investigate the clinical features of pregnancy in women with Takayasu’s arteritis managed in a tertiary medical center and review the literature in order to establish the course and recommended follow up and treatment for these pregnancies.

Materials and methods: Retrospective analysis of 20 pregnancies in 6 women with Takayasu’s arteritis. Patients were recruited from the high risk pregnancy clinics at Sheba Medical Center, where follow up included strict control of blood pressure and treatment of obstetric and disease-related complications.

Results: Mean maternal age was 29.3?±?3 years. Thirty-six patients had both supra and infradiaphragmatic arterial disease, of them two had an abdominal aorta involvement and three out of six patients had an isolated supradiaphragmatic disease. Of 20 pregnancies, six pregnancies (30%) resulted in early spontaneous miscarriages, and one pregnancy was terminated at 17 weeks due to fetal anomalies. The remaining 13 pregnancies (65%) resulted in live births. Three out of 13 (23%) neonates were small-for-gestational-age. The most common complication was maternal hypertension affecting 8/13 (61.5%) pregnancies. Preeclampsia occurred in one pregnancy. Four out of 13 (30.7%) pregnancies necessitated preterm induction of labor due to obstetric indications or uncontrolled disease.

Conclusions: Although Takayasu’s arteritis is associated with pregnancy complications, tight preconception disease control, strict follow up, and targeted treatment of high blood pressure can result in positive pregnancy outcome.  相似文献   
80.
There are no previous studies of the association between prediagnostic serum vitamin D concentration and glioma. Vitamin D has immunosuppressive properties; as does glioma. It was, therefore, our hypothesis that elevated vitamin D concentration would increase glioma risk. We conducted a nested case-control study using specimens from the Janus Serum Bank cohort in Norway. Blood donors who were subsequently diagnosed with glioma (n = 592), between 1974 and 2007, were matched to donors without glioma (n = 1112) on date and age at blood collection and sex. We measured 25-hydroxyvitamin D [25(OH)D], an indicator of vitamin D availability, using liquid chromatography coupled with mass spectrometry. Seasonally adjusted odds ratios (ORs) and 95% confidence intervals (95% CIs) were estimated for each control quintile of 25(OH)D using conditional logistic regression. Among men diagnosed with high grade glioma >56, we found a negative trend (P = .04). Men diagnosed ≤ 56 showed a borderline positive trend (P = .08). High levels (>66 nmol/L) of 25(OH)D in men >56 were inversely related to high grade glioma from ≥2 yr before diagnosis (OR = 0.59; 95% CI = 0.38, 0.91) to ≥15 yr before diagnosis (OR = 0.61; 95% CI = 0.38,0.96). Our findings are consistent long before glioma diagnosis and are therefore unlikely to reflect preclinical disease.  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