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   9982篇
  免费   787篇
  国内免费   288篇
耳鼻咽喉   12篇
儿科学   443篇
妇产科学   66篇
基础医学   2077篇
口腔科学   30篇
临床医学   984篇
内科学   2324篇
皮肤病学   746篇
神经病学   188篇
特种医学   101篇
外科学   940篇
综合类   1737篇
预防医学   211篇
眼科学   78篇
药学   615篇
  3篇
中国医学   469篇
肿瘤学   33篇
  2024年   7篇
  2023年   166篇
  2022年   206篇
  2021年   311篇
  2020年   316篇
  2019年   357篇
  2018年   322篇
  2017年   304篇
  2016年   327篇
  2015年   324篇
  2014年   554篇
  2013年   849篇
  2012年   484篇
  2011年   543篇
  2010年   432篇
  2009年   451篇
  2008年   466篇
  2007年   513篇
  2006年   468篇
  2005年   395篇
  2004年   421篇
  2003年   329篇
  2002年   328篇
  2001年   270篇
  2000年   233篇
  1999年   210篇
  1998年   174篇
  1997年   151篇
  1996年   106篇
  1995年   122篇
  1994年   122篇
  1993年   120篇
  1992年   100篇
  1991年   84篇
  1990年   91篇
  1989年   53篇
  1988年   58篇
  1987年   43篇
  1986年   40篇
  1985年   41篇
  1984年   41篇
  1983年   22篇
  1982年   31篇
  1981年   20篇
  1980年   16篇
  1979年   12篇
  1978年   13篇
  1977年   5篇
  1976年   2篇
  1975年   2篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
BackgroundThe association between systemic lupus erythematosus (SLE) and sarcoidosis has been considered as extremely rare. Most often, sarcoidosis coexists with Sjögren's syndrome. Researching the literature, it seems that the association of SLE and sarcoidosis is much more frequent than previously thought.Aim of the workWe present a case of a Serbian woman who was diagnosed with coexisting sarcoidosis and long-standing SLE.Case presentationThe 40 years old SLE patient was in long-standing remission on oral prednisolone (10 mg/day) and hydroxychloroquine (HCQ) (400 mg/day). She presented with fatigue, chest pain, and dry cough. Chest computerized tomography (CT) showed hilar and mediastinal lymphadenopathy. The biopsy had been performed and results showed sarcoidosis. Diagnosis has been confirmed: eosinophilic granulomas without central necrosis morphologically corresponding to chronic granulomatous lymphadenitis like sarcoidosis. Thereafter, the patient was hospitalized. No new symptoms appeared, and the physical examination was unremarkable. Serum calcium was elevated (2.75 mmol/l), anti-nuclear antibody (ANA), anti-double stranded deoxyribonucleic acid (anti-dsDNA) and anti-Ro antibodies were positive. Angiotensin converting enzyme (ACE) level was high normal (51 IU/L) and QuantiFERON-TB Gold test negative. The dose of prednisolone was increased to 40 mg/day with HCQ and the patient was discharged from hospital. On follow-up the patient improved with reduction of the steroid dose.ConclusionThe association of SLE and sarcoidosis should be considered even though it is reported to be extremely rare. May be the real incidence of these combinations is underestimated. More research about genetics and pathogenesis is needed to completely understand these conditions.  相似文献   
2.
3.
4.
5.
Discoid lupus erythematosus (DLE) is the most common skin manifestation of lupus; however, the molecular mechanisms underlying DLE remain unknown. Therefore, we aimed to identify key differentially expressed genes (DEGs) in discoid lupus skin and investigate their potential pathways.To identify candidate genes involved in the occurrence and development of the disease, we downloaded the microarray datasets GSE52471 and GSE72535 from the Gene Expression Database (GEO). DEGs between discoid lupus skin and normal controls were selected using the GEO2R tool and Venn diagram software (http://bioinformatics.psb.ugent.be/webtools/Venn/). The Database for Annotation, Visualization, and Integrated Discovery (DAVID), Enrichr, and Cytoscape ClueGo were used to analyze the Kyoto Encyclopedia of Gene and Genome pathways and gene ontology. Protein-protein interactions (PPIs) of these DEGs were further assessed using the Search Tool for the Retrieval Interacting Genes version 10.0.Seventy three DEGs were co-expressed in both datasets. DEGs were predominantly upregulated in receptor signaling pathways of the immune response. In the PPI network, 69 upregulated genes were selected. Furthermore, 4 genes (CXCL10, ISG15, IFIH1, and IRF7) were found to be significantly upregulated in the RIG-I-like receptor signaling pathway, from analysis of Enrichr and Cytoscape ClueGo.The results of this study may provide new insights into the potential molecular mechanisms of DLE. However, further experimentation is required to confirm these findings.  相似文献   
6.
Neutrophils can form neutrophil extracellular traps (NETs) to capture microbes and facilitate their clearance. NETs consist of decondensed chromatin decorated with anti-microbial proteins. Here, we describe the effect of neutrophil proteases on the protein content of NETs. We show that the neutrophil serine proteases degrade several neutrophil proteins associated with NETs. Interestingly, the anti-bacterial proteins associated with NETs, such as myeloperoxidase, calgranulin B and neutrophil elastase (NE), seem to be less susceptible to proteolytic degradation than other NET proteins, such as actin and MNDA. NETs have been proposed to play a role in autoimmune reactions. Our data demonstrate that a large number of the autoepitopes of NET proteins that are recognized by autoantibodies produced by systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) patients are also removed by the proteases. In conclusion, neutrophil serine proteases have a major impact on the NET proteome and the proteolytic changes of NET-associated proteins may counteract autoimmune reactions to NET components.  相似文献   
7.
Background: Pulmonary manifestations of systemic lupus erythematosus (SLE) are appearing in 4-5% of patients involving lung in almost half of the cases during the disease course. Objective: We compared the autoimmune pulmonary inflammation in the lung tissue of mice to determine the association between decreased expression levels of Forkhead Box J1 (FOXJ1) and the activation of the NF-κB pathway in autoimmune pulmonary inflammation of MRL/Lpr mice. Methods: The female BALB/c mice (n=6) and MRL/Lpr mice (n=30) were divided into 5 groups including a control group (BALB/c), and five MRL/Lpr mice groups (8W, 12W, 16W, 24W, and 32W). The infiltration of the inflammatory cells was determined in lung tissue by performing the histological analysis. The western blotting was used to examine the expression levels of the age-related FOXJ1, and p50 and p65 proteins in the lungs of MRL/Lpr mice. The expression levels of MMP2 and MMP9 were determined via immunohistochemistry and immunofluorescence. Results: There were severe infiltrates of lung cells with high levels of tracheal damage, perivascular injury and interstitial inflammatory cell infiltration when the MRL/Lpr mice from 16w to 32w comparing to the 8w old healthy MRL/Lpr mice in the control group (p <0.05). Moreover, the reduced expression levels of FOXJ1 were associated with the activation of the NF-κB pathway in interstitial lung disease of MRL/Lpr mice via the modulation of p50 and p65. In addition, the expression levels of MMP2 and MMP9 pro-inflammation factors increased in the lungs of the MRL/Lpr mice from 16w to 32w. Conclusions: The expression level of FOXJ1 might be an indicator of the degree of lung disease in lupus-prone mice.  相似文献   
8.
9.
Immune dysregulation is a cardinal feature of autoimmune diseases and chronic microbial infections. In particular, regulatory T cells are downregulated in autoimmune diseases while upregulated in chronic microbial infections. FOXP3 is the master regulator of Treg development. Treg-specific demethylated region (TSDR) is a highly conserved locus on the FOXP3 gene that is fully demethylated in natural Tregs but methylated in effector T cells. In our study, we used high resolution melt-polymerase chain reaction (HRM-PCR) to determine the FOXP3 TSDR methylation status in autoimmune diseases and chronic microbial infections. We found that FOXP3 TSDR to have the highest mean melting temperature (highly methylated) in active SLE patients compared to all the other groups (p?<?0.001). The psoriasis group also had a significantly high mean melting temperature (78.62?±?0.20) when compared with the inactive SLE group (78.49?±?0.29, p?<?0.05) and control group (78.44?±?0.25, p?<?0.01). There was no significant difference in melting temperature between inactive SLE and healthy controls. Disease activity in SLE was directly associated with methylation of the FOXP3 TSDR. On the other hand, patients with chronic microbial infections had significantly lower FOXP3 TSDR mean melting temperature (demethylated) when compared with healthy controls (78.28?±?0.21 vs 78.44?±?0.25, p?<?0.05). Our results suggest that the use of HRM-PCR to detect FOXP3 TSDR methylation status is a reliable and easy method to predict natural regulatory T cell levels in peripheral blood in different disease conditions. Determining FOXP3 TSDR methylation status can be a useful tool in diagnosis, and monitoring the severity of autoimmune diseases and chronic microbial infections.  相似文献   
10.

Background and aims

Since accelerated atherosclerosis has been reported in systemic lupus erythematosus (SLE), predictive biomarkers of cardiovascular disease (CVD) are needed. Among non-traditional risk factors, bone mineral density (BMD) has been related to CVD. However, its role in SLE remains controversial. This study aims to analyze the associations of subclinical atherosclerosis with traditional and non-traditional CV risk factors.

Methods and results

In a cross-sectional study, atherosclerosis burden was compared between 112 female SLE patients and 31 controls. Plaque number and carotid intima-media wall thickness (cIMT) were assessed by ultrasonography. In a retrospective study, BMD determinations obtained 5-years before the ultrasonography assessment were analyzed in a subgroup of 62 patients. Plaque frequency was increased in SLE, even in patients without CV events or carotid wall thickening. cIMT was increased in patients with CVD, positively correlated with body mass index (BMI). Interestingly, a paradoxical effect of BMI on carotid parameters was observed. Whereas underweight patients (BMI < 20) showed increased prevalence of carotid plaques with low cIMT, those with BMI > 30 showed higher cIMT and plaque burden. Overweight patients (25 < BMI<30) exhibited both elevated cIMT and plaque number. BMI was an independent predictor of BMD. In our retrospective study, patients with either clinical or subclinical CVD exhibited lower BMD levels than their CV-free counterparts. A low lumbar spine BMD independently predicted CVD development after adjusting for confounders.

Conclusion

SLE was associated with a higher subclinical atherosclerosis burden, a bimodal effect being observed for BMI. Decreased BMD can be a CV risk biomarker in SLE.  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