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   2652篇
  免费   200篇
  国内免费   112篇
耳鼻咽喉   14篇
儿科学   35篇
妇产科学   78篇
基础医学   237篇
口腔科学   40篇
临床医学   245篇
内科学   742篇
皮肤病学   20篇
神经病学   216篇
特种医学   24篇
外科学   337篇
综合类   104篇
预防医学   177篇
眼科学   20篇
药学   237篇
  1篇
中国医学   20篇
肿瘤学   417篇
  2024年   10篇
  2023年   102篇
  2022年   194篇
  2021年   283篇
  2020年   240篇
  2019年   207篇
  2018年   224篇
  2017年   174篇
  2016年   176篇
  2015年   126篇
  2014年   292篇
  2013年   209篇
  2012年   106篇
  2011年   140篇
  2010年   86篇
  2009年   94篇
  2008年   88篇
  2007年   73篇
  2006年   41篇
  2005年   27篇
  2004年   15篇
  2003年   14篇
  2002年   11篇
  2001年   6篇
  2000年   3篇
  1999年   8篇
  1998年   4篇
  1997年   2篇
  1996年   4篇
  1994年   1篇
  1993年   1篇
  1991年   1篇
  1989年   1篇
  1979年   1篇
排序方式: 共有2964条查询结果,搜索用时 31 毫秒
31.
Objective: To identify novel potential biomarkers and evaluate combined biomarkers for diagnosing kidney injury with considerable accuracy in preeclampsia. Methods: The level of serum and urine neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), retinol-binding protein (RBP) and interleukin-18 (IL-18) were measured by enzyme-linked immunosorbent assay. Results: The level of serum cystatin C, urine RBP, urine NGAL and urine KIM-1 in preeclampsia group were higher than that in the normal pregnancy group. When four biomarkers are combined, the sensitivity and specificity are 100%/98.20%. Conclusion: Urine KIM-1 is the most potential biomarker for renal injury in preeclampsia. The more biomarkers combined, the more sensitivity and specificity were increased.  相似文献   
32.
33.
34.
35.
Asthma is a complex, chronic respiratory disease with a wide clinical spectrum. Use of high-throughput technologies has generated a great deal of data that require validation. In this work the objective was to validate molecular biomarkers related to asthmatic disease types in peripheral blood samples and define their relationship with disease severity. With this purpose, ninety-four previously described genes were analyzed by qRT-PCR in 30 healthy control (HC) subjects, 30 patients with nonallergic asthma (NA), 30 with allergic asthma (AA), and 14 patients with allergy (rhinitis) but without asthma (AR). RNA was extracted from peripheral blood mononuclear cells (PBMCs) using the TRIzol method. After data normalization, principal component analysis (PCA) was performed, and multiple approaches were used to test for differential gene expression. Relevance was defined by RQ (relative quantification) and corrected P value (<0.05). Protein levels of IL-8 and MSR1 were determined by ELISA and Western blot, respectively.PCA showed 4 gene expression clusters that correlated with the 4 clinical phenotypes. Analysis of differential gene expression between clinical groups and HCs revealed 26 statistically relevant genes in NA and 69 in AA. Protein interaction analysis revealed IL-8 to be a central protein. Average levels of IL-8 were higher in the asthma patients’ sera (NA: 452.28 ± 357.72, AA: 327.46 ± 377 pg/ml) than in HCs (286.09 ± 179.10), but without reaching statistical significance. Nine genes, especially MSR1, were strongly associated with severe NA.In conclusion, several molecular biomarkers of asthma have been defined, some of which could be useful for the diagnosis or prognosis of disease severity.  相似文献   
36.
37.
The general aim of this study is to create a cohort of asthma patients with varying grades of severity in order to gain greater insight into the mechanisms underlying the genesis and course of this disease.The specific objectives focus on various studies, including imaging, lung function, inflammation, and bronchial hyperresponsiveness, to determine the relevant events that characterize the asthma population, the long-term parameters that can determine changes in the severity of patients, and the treatments that influence disease progression. The study will also seek to identify the causes of exacerbations and how this affects the course of the disease.Patients will be contacted via the outpatient clinics of the 8 participating institutions under the auspices of the Spanish Respiratory Diseases Networking System (CIBER). In the inclusion visit, a standardized clinical history will be obtained, a clinical examination, including blood pressure, body mass index, complete respiratory function tests, and FENO will be performed, and the Asthma Control Test (ACT), Morisky-Green test, Asthma Quality of Life Questionnaire (Mini AQLQ), the Sino-Nasal Outcome Test 22 (SNOT-22), and the Hospital Anxiety and Depression scale (HADS) will be administered. A specific electronic database has been designed for data collection. Exhaled breath condensate, urine and blood samples will also be collected. Non-specific bronchial hyperresponsiveness testing with methacholine will be performed and an induced sputum sample will be collected at the beginning of the study and every 24 months. A skin prick test for airborne allergens and a chest CT will be performed at the beginning of the study and repeated every 5 years.  相似文献   
38.
Based on the data of the First Zurich Longitudinal Growth Study we investigate how interindividual differences in adult size arise in the variables leg height, sitting height and standing height, arm length, biiliac width and bihumeral width. Specifically, we are also interested in the question of whether across sexes and variables the same growth phases and the same parameters are predictive for achieving a certain adult size. A rather complex pattern emerges, demonstrating that regulation of growth is not the same for boys and girls and moreover is not the same for the six anthropometric variables studied. Prepubertal growth is characterized by its intensity (average velocity) and by its duration. Whereas duration has by itself no appreciable influence on adult size, prepubertal intensity determines adult size to a high degree across all variables and both sexes. The intensity of prepubertal growth determines adult size to a larger degree for boys than for girls. For a given size at the end of the prepubertal period, a small duration enhances the chance of obtaining a large adult size. Compared with prepubertal growth, the amount of variance of adult size explained is small for pubertal parameters, and - with respect to linear measures - significant for girls only. A small duration of prepubertal growth is in the following mainly compensated by a stronger pubertal spurt (PS), to a varying degree across variables. The overall picture which emerges indicates that sitting height - and to a lesser extent bihumeral width - develop in a more irregular fashion than the variables biiliac width and leg height.  相似文献   
39.
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   
40.
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