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   1676篇
  免费   139篇
  国内免费   29篇
耳鼻咽喉   9篇
儿科学   25篇
妇产科学   6篇
基础医学   313篇
口腔科学   73篇
临床医学   307篇
内科学   274篇
皮肤病学   25篇
神经病学   36篇
特种医学   29篇
外科学   126篇
综合类   218篇
预防医学   115篇
眼科学   10篇
药学   52篇
  11篇
中国医学   92篇
肿瘤学   123篇
  2024年   5篇
  2023年   46篇
  2022年   89篇
  2021年   107篇
  2020年   107篇
  2019年   94篇
  2018年   97篇
  2017年   91篇
  2016年   93篇
  2015年   64篇
  2014年   155篇
  2013年   152篇
  2012年   93篇
  2011年   95篇
  2010年   82篇
  2009年   58篇
  2008年   64篇
  2007年   48篇
  2006年   54篇
  2005年   41篇
  2004年   29篇
  2003年   16篇
  2002年   17篇
  2001年   12篇
  2000年   15篇
  1999年   11篇
  1998年   16篇
  1997年   12篇
  1996年   16篇
  1995年   8篇
  1994年   9篇
  1993年   10篇
  1992年   9篇
  1991年   7篇
  1990年   4篇
  1989年   3篇
  1988年   3篇
  1987年   3篇
  1986年   2篇
  1985年   1篇
  1984年   2篇
  1981年   3篇
  1978年   1篇
排序方式: 共有1844条查询结果,搜索用时 15 毫秒
71.

Objectives

To date, very few studies have paid attention to the joint sense (proprioception) of toes other than the big toe. We evaluated the sensitivity of joint position sense at the joint of the great toe in comparison to other digits, and with that determined by the dual digit stimulation test, in a sample of healthy normal controls and patients with clinical diagnosis of the lemniscal system dysfunction.

Material and methods

Seventy-two patients with lemniscal system dysfunction (55 clinically definitive multiple sclerosis, 17 vasculitis) and 110 healthy volunteers participated in the study. All subjects underwent the joint position sense test of all digits of upper and lower extremities. The position sense resulting from the combined operation of the joints of the second and the fourth digits (simultaneous two digits position sense) was also measured and subsequently compared with the results of the great toe position sense.

Results

Upper extremities: no difference was found in recognition of the position sense in the single digits of the upper extremities between patients and healthy volunteers. There was a significant difference in the dual joint position test of the right upper extremity between patients and the case group (p < 0.05) but not in the left upper extremity. Lower extremities: there was no significant difference in proprioception of the great toe neither in the right and nor in the left side between patients and normal subjects. However, the joint position sense of other single digits was deteriorated in the patients, a difference that was significant compared to normal controls (p < 0.05). Additionally, patients and normal controls displayed a difference in dual digit position sense of the right and left lower extremities (p < 0.05).

Conclusions

We show in this paper that the proprioception of simultaneous dual digits is diminished in patients when compared to a single digit position sense. Moreover, the great toe proprioception is less sensitive than other digits. Taken together, these observations lend evidence for a new clinical method which we named as dual joint position test. We suggest this novel method offers clinical utility to demonstrate lemniscal system dysfunction.  相似文献   
72.
73.
Background: Lactase persistence is an autosomal dominant trait commonly distributed in Europe as well as some parts of east Africa and the Arabian Peninsula. Using real-time PCR to detect the ?13910C?>?T variant common in the European population is a reliable analysis although other variants in the probe-binding site may cause errors in analysis. The aim of this study was to determine the prevalence of the variants in a Danish cohort examined for lactose intolerance as well as to improve the real-time PCR analysis for detection of the different variants.

Methods: We genotyped 3395 routine samples using real-time PCR for the ?13910C?>?T-variant. All consecutive samples identified as ?13910CC were sequenced using Sanger Sequencing. Using the SDS software we examined various quality value settings to improve on the genetic analysis.

Results: Using real-time PCR resulted in 100% successful genotyping of the ?13910C?>?T variant. By using a quality value of 99% and sequencing the undetermined samples we improved the ability of the assay to identify variants other than ?13910C?>?T. This resulted in a reduction of the diagnostic error rate by a factor of 2.4 while increasing the expenses only 3%.

Conclusions: We conclude that using a quality value of 99% in the SDS software significantly improves the diagnostic efficiency of the real-time PCR assay for detecting variants associated to lactase persistence.  相似文献   
74.
Respiratory syncytial virus (RSV) is a major cause of respiratory tract infections in infants, with remarkable variability in disease severity. Factors determining severity of disease in previously healthy infants are still unclear. It was hypothesized that disease severity is correlated with viral load in primary RSV infection. Infants of a healthy birth cohort were included at signs of their first respiratory tract infection. Nasopharyngeal aspirate was obtained within 48–96 hr and disease severity was assessed with a previously published severity scoring model. PCR was applied to test the aspirates in a semi‐quantitative way for the presence of 10 respiratory pathogens. In case of multiple infection, the pathogen with the highest load was defined as the primary pathogen. The correlation between disease severity and viral load was analyzed. A total of 82 infants were included over a period of 2 years. Median age at first respiratory tract infection was 3 months. Pathogens were detected in 77 (94%) infants; more than one pathogen was detected in 35 (43%) infants. RSV was present in aspirates of 30 infants; in 16 aspirates RSV was the primary pathogen. A negative correlation between RSV CT‐value and disease severity was found in all RSV cases (ρ = ?0.52, P = 0.003) and in cases with RSV as the primary pathogen (ρ = ?0.54, P = 0.03). In conclusion, this is the first report on viral loads in previously healthy infants with RSV infection in the community. Disease severity correlated positively with viral load during primary RSV infection. J. Med. Virol. 82: 1266–1271, 2010. © 2010 Wiley‐Liss, Inc.  相似文献   
75.
Subtelomeric rearrangements are believed to be responsible for 5-7% of idiopathic mental retardation cases. Due to the relative complexity and high cost of the screening methods used till now, only preselected patient populations including mostly the more severely affected cases have been screened. Recently, multiplex ligation-dependent probe amplification (MLPA) has been adapted for use in subtelomeric screening, and we have incorporated this technique into routine diagnostics of our laboratory. Since the evaluation of MLPA as a screening method, we tested 275 unselected patients with idiopathic mental retardation and detected 12 possible subtelomeric aberrations: a der(11)t(11;20)(qter;qter), a 19pter duplication, a der(18)t(18;10)(qter; pter), a 15qter deletion, a 8pter deletion, a 6qter deletion, a der(X)t(X;1)(pter;qter), a der(X)t(X;3)(pter;pter), a 5qter duplication, a 3pter deletion, and two 3qter duplications. The patients can be subdivided into two groups: the first containing de novo rearrangements that are likely related to the clinical presentation of the patient and the second including aberrations also present in one of the parents that may or may not be causative of the mental retardation. In our patient cohort, five (1.8%) subtelomeric rearrangements were de novo, three (1.1%) rearrangements were familial and suggestively disease causing, and four (1.5%) were possible polymorphisms. This high frequency of subtelomeric abnormalities detected in an unselected population warrants further investigation about the feasibility of routine screening for subtelomeric aberrations in mentally retarded patients.  相似文献   
76.
Non-alcoholic fatty liver disease (NAFLD) comprises a spectrum of metabolic states ranging from simple steatosis o inflammation with associated fibrosis to cirrhosis. Though accumulation of hepatic fat is not associated with a ignificant increase in mortality rates, hepatic inflammation is, as this augments the risk of terminal liver disease, i.e., cirrhosis, hepatic decompensation (liver failure) and/or hepatocellular carcinoma. Disease progression is usually low, over a decade or more and, for the most part, remains asymptomatic. Recent estimates suggest that the global prevalence of NAFLD is high, about one in four. In most cases, NAFLD overlaps with overweight, obesity, cardiovascular disease and the metabolic syndrome with numerous contributing parameters including a dysregulation of adipose tissue, insulin resistance, type 2 diabetes, changes in the gut microbiome, neuronal and hormonal dysregulation and metabolic stress. NAFLD is diagnosed incidentally, despite its high prevalence. Non-invasive maging techniques have emerged, making it possible to determine degree of steatosis as well asfibrosis. Despite this, he benefit of routine diagnostics remains uncertain. A better understanding of the (molecular) pathogenesis of NAFLD is needed combined with long-term studies where benefits of treatment can be assessed to determine cost benefit ratios. This review summarizes the current state of knowledge and possible areas of treatment.  相似文献   
77.
The important insights gained over the past years in diagnosis and treatment of invasive adenoviral infections provide new paradigms for the monitoring and clinical management of these life‐threatening complications. A meeting was held to discuss and subsequently disseminate the current advances in our understanding of the aetiology/pathogenesis and future treatment options facilitating effective control or prevention of adenovirus‐related diseases in the allogeneic haematopoietic stem cell transplant setting. Invited experts in the field discussed recent progress with leading members of the Infectious Diseases Working Party of the European Society of Blood and Marrow Transplantation at the “State‐of‐the‐art” Meeting in Poznan, Poland, in October 2017. In this review article, the panel of experts presents a concise summary of the current evidence based on published data from the last 15 years and on recent achievements resulting from real‐life practice. The present position statement reflects an expert opinion on current approaches to clinical management of adenovirus infections in patients undergoing allogeneic haematopoietic stem cell transplant and provides graded recommendations of the panel for diagnostic approaches and preemptive therapy reflecting the present state of knowledge.  相似文献   
78.
79.
Accurate and detailed understanding of the effects of variants in the coding and noncoding regions of the genome is the next big challenge in the new genomic era of personalized medicine, especially to tackle newer findings of genetic and phenotypic heterogeneity of diseases. This is necessary to resolve the gene‐variant–disease relationship, the pathogenic variant spectrum of genes, pathogenic variants with variable clinical consequences, and multiloci diseases. In turn, this will facilitate patient recruitment for relevant clinical trials. In this review, we describe the trends in research at the intersection of basic and clinical genomics aiming to (a) overcome molecular diagnostic challenges and increase the clinical utility of next‐generation sequencing (NGS) platforms, (b) elucidate variants associated with disease, (c) determine overall genomic complexity including epistasis, complex inheritance patterns such as “synergistic heterozygosity,” digenic/multigenic inheritance, modifier effect, and rare variant load. We describe the newly emerging field of integrated functional genomics, in vivo or in vitro large‐scale functional approaches, statistical bioinformatics algorithms that support NGS genomics data to interpret variants for timely clinical diagnostics and disease management. Thus, facilitating the discovery of new therapeutic or biomarker options, and their roles in the future of personalized medicine.  相似文献   
80.
T cell cytokine release assays are used to diagnose infectious diseases, but not autoimmune or allergic disease. Coeliac disease (CD) is a common T cell-mediated disease diagnosed by the presence of gluten-dependent intestinal inflammation and serology. Many patients cannot be diagnosed with CD because they reduce dietary gluten before medical workup. Oral gluten challenge in CD patients treated with gluten-free diet (GFD) mobilizes gluten-reactive T cells measurable by interferon (IFN)-γ enzyme-linked immunospot (ELISPOT) or major histocompatibility complex (MHC) class II tetramers. Immunodominant peptides are quite consistent in the 90% of patients who possess HLA-DQ2·5. We aimed to develop whole blood assays to detect gluten-specific T cells. Blood was collected before and after gluten challenge from GFD donors confirmed to have CD (n = 27, all HLA-DQ2·5+), GFD donors confirmed not to have CD (n = 6 HLA-DQ2·5+, 11 HLA-DQ2·5) and donors with CD not following GFD (n = 4, all HLA-DQ2·5+). Plasma IFN-γ and IFN-γ inducible protein-10 (IP-10) were measured by enzyme-linked immunosorbent assay (ELISA) after whole blood incubation with peptides or gliadin, and correlated with IFN-γ ELISPOT. No T cell assay could distinguish between CD patients and controls prior to gluten challenge, but after gluten challenge the whole blood IFN-γ ELISA and the ELISPOT were both 85% sensitive and 100% specific for HLA-DQ2·5+ CD patients; the whole blood IP-10 ELISA was 94% sensitive and 100% specific. We conclude that whole blood cytokine release assays are sensitive and specific for detection of gluten-reactive T cells in CD; further clinical studies addressing the utility of these tests in patients with an uncertain diagnosis of CD is warranted.  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