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   1108篇
  免费   167篇
  国内免费   135篇
耳鼻咽喉   11篇
儿科学   20篇
妇产科学   35篇
基础医学   217篇
口腔科学   21篇
临床医学   76篇
内科学   310篇
皮肤病学   7篇
神经病学   62篇
特种医学   16篇
外科学   138篇
综合类   142篇
预防医学   37篇
眼科学   14篇
药学   66篇
  1篇
中国医学   8篇
肿瘤学   229篇
  2024年   1篇
  2023年   16篇
  2022年   55篇
  2021年   109篇
  2020年   76篇
  2019年   56篇
  2018年   52篇
  2017年   71篇
  2016年   104篇
  2015年   119篇
  2014年   184篇
  2013年   160篇
  2012年   127篇
  2011年   116篇
  2010年   70篇
  2009年   49篇
  2008年   26篇
  2007年   16篇
  2006年   3篇
排序方式: 共有1410条查询结果,搜索用时 46 毫秒
161.
miRNAs (MicroRNAs), known as noncoding and important endogenous factors regulating the expression protein-coding genes, are vital regulators in each biological process. Thus, this study aims to explore the key role of four microRNAs in regulating the spermatogenesis. To conduct this experiment, 55 infertile and fertile men provided the study with the sperm and testicular tissue samples. To study the spermatozoa in terms of the morphology, Diff-Quick was applied. Then, quantitative real-time polymerase chain reaction (RT-PCR) was conducted on samples. Our data indicated that in contrast to the miR-15b, significant increasing of miR-383 and miR-122 occurred in both severe oligoasthenoteratozoospermia (SOAT) and moderate oligoasthenoteratozoospermia (MOAT) compared to normal sperm group (N). In addition, it was observed that miR-15b and miR-122 increased in patients with nonobstructive azoospermia (NOA) compared with obstructive azoospermia (OA) group. Expression levels of target genes including P53, CASPASE-9 and CYCLIN D1 underwent principle changes according to miRNAs expression level. Our finding indicated that miRNAs had essential role in the regulation of spermatogenesis, and their expression altering was associated with sperm abnormalities. Thus, microRNAs can be introduced as useful biomarkers to determine male infertility reasons to choose the effective treatment.  相似文献   
162.
The clinical role and potential molecular mechanisms of microRNA-449c-5p (miR-449c-5p) in hepatocellular carcinoma (HCC) tissues remains unclear. Combining multiple bioinformatic tools, we studied the miR-449c-5p expression levels in HCC tissues and explored possible target genes and related signaling pathways. First, miR-449c-5p expression data from microarrays provided by publicly available sources were mined and analyzed using various meta-analysis methods. Next, genes that were downregulated after miR-449c-5p mimic transfection into HCC cells were identified, and in silico methods were used to predict potential target genes. Several bioinformatic assessments were also performed to evaluate the possible signaling pathways of miR-449c-5p in HCC. Five microarrays were included in the current study, including GSE98269, GSE64632, GSE74618, GSE40744 and GSE57555. The standard mean difference was 0.44 (0.07–0.80), and the area under the curve was 0.68 (0.63–0.72), as assessed by meta-analyses, which consistently indicated the upregulation of miR-449c-5p in HCC tissues. A total of 2244 genes were downregulated after miR-449c-5p mimic transfection into an HCC cell line, while 5217 target genes were predicted by in silico methods. The overlap of these two gene pools led to a final group of 428 potential target genes of miR-449c-5p. These 428 potential target genes were primarily enriched in the homologous recombination pathway, which includes DNA Polymerase Delta 3 (POLD3). Data mining with Oncomine and the Human Protein Atlas showed a decreasing trend in POLD3 mRNA and protein levels in HCC tissue samples. This evidence suggests that miR-449c-5p could play an essential role in HCC through various pathways and that POLD3 could be a potential miR-449c-5p target. However, these in silico findings should be validated with further experiments.  相似文献   
163.
《Clinical breast cancer》2020,20(5):422-430
BackgroundBreast cancer is the most commonly diagnosed cancer and the leading cause of cancer death among females. Circular RNAs (circRNAs) have been implicated in the initiation and development of cancer. Here, we explored the biological role and regulatory mechanism of circCDYL in breast cancer.Materials and MethodsThe expression and correlation of circCDYL/miR-190a-3p/TP53INP1 axis in breast cancer tissues and cells were determined by quantitative polymerase chain reaction and Western blot. Cell-counting Kit-8, colony formation, cell migration, and invasion assays were applied to investigate the biological roles of circCDYL in breast cancer development and progression.ResultsCircCDYL were down-regulated in breast cancer tissues and cells, the expression of which positively correlated with patients’ survival rate. CircCDYL worked as a “sponge,” binding to miR-190a-3p directly, which inhibited the expression of miR-190a-3p and relieved the inhibition of tumor suppressor gene TP53INP1.ConclusionCircCDYL promotes apoptosis and inhibits proliferation of the malignant phenotype of breast cancer through regulating miR-190a-3p/TP53INP1 axis, which suggests that circCDYL is a potential therapeutic target for breast cancer.  相似文献   
164.
Atherosclerosis is a chronic inflammatory disorder of the vasculature and is the primary cause of cardiovascular disease(CVD). CVD is currently the world's leading cause of death and the numbers are predicted to rise further because of a global increase in risk factors such as diabetes and obesity. Current therapies such as statins have had a major impact in reducing mortality from CVD. However, there is a marked residual CVD risk in patients on statin therapy. It is therefore important to understand the molecular basis of this disease in detail and to develop alternative novel therapeutics. Interferon-γ(IFN-γ) is a pro-inflammatory cytokine that is often regarded as a master regulator of atherosclerosis development. IFN-γ is able to influence several key steps during atherosclerosis development, including pro-inflammatory gene expression, the recruitment of monocytes from the blood to the activated arterial endothelium and plaque stability. This central role of IFN-γ makes it a promising therapeutic target. The purpose of this editorial is to describe the key role IFN-γ plays during atherosclerosis development, as well as discuss potential strategies to target it therapeutically.  相似文献   
165.
166.
167.
微小RNA(miRNA)是一类高度保守的内源性小分子RNA。miRNA主要通过选择性结合mRNA调控基因表达。目前研究结果表明,中枢神经系统存在大量miRNA,并参与神经细胞的正常生长、发育,以及组织损伤修复、肿瘤发生、神经退行性变等多种病理、生理过程。笔者拟就新生儿缺血缺氧性脑病(HIE) miRNA谱系的最新研究进展进行阐述,探讨其miRNA特异性表达,对新生儿HIE诊断和预后判断的意义,旨在为该病的相关诊治研究提供参考。  相似文献   
168.
MicroRNAs(miRNAs)是一类内源性的小分子单链非编码RNA,通过调节基因的表达在许多生命活动中起重要作用。在一些疾病(如癌症和自身免疫性疾病)发生时,miRNAs的表达谱可能发生改变,所以在药物的安全性评价中,其有望成为诊断或预后生物标志物。因此,准确测定miRNA的表达对于其应用十分重要。对传统的RNA印记(Northernblotting)、微阵列(microarray)和实时定量PCR(qRT-PCR)以及一些新的miRNAs检测方法(如基于纳米材料的miRNAs检测、核酸扩增等技术)进行概述,并阐述了这些方法的优缺点。  相似文献   
169.
170.
Infection of high-risk human papillomaviruses (HPVs) is a prerequisite for the development of cervical carcinoma. HPV infections are also implicated in the development of other types of carcinomas. Chronic or persistent infection of HPV is essential but HPV alone is inadequate, additional endogenous or exogenous cues are needed along with HPV to induce cervical carcinogenesis. The strategies that high-risk HPVs have developed in differentiating epithelial cells to reach a DNA-synthesis competent state leading to tumorigenic transformation are basically due to overexpression of the E6 and E7 oncoproteins and the activation of diverse cellular regulatory or signaling pathways that are targeted by them. Moreover, the Wnt/β-catenin/Notch and phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) pathways are deregulated in various cancers, and have also been implicated in HPV-induced cancers. These are basically related to the “cancer hallmarks,” and include sustaining proliferative signals, the evasion of growth suppression and immune destruction, replicative immortality, inflammation, invasion, metastasis and angiogenesis, as well as genome instability, resisting cell death, and deregulation of cellular energetics. These information could eventually aid in identifying or developing new diagnostic, prognostic biomarkers, and may contribute to design more effective targeted therapeutics and treatment strategies. Although surgery, chemotherapy and radiotherapy can cure more than 90% of women with early stage cervical cancer, the recurrent and metastatic disease remains a major cause of cancer mortality. Numerous efforts have been made to design new drugs and develop gene therapies to treat cervical cancer. In recent years, research on treatment strategies has proposed several options, including the role of HPV E5, E6, and E7 oncogenes, which are retained and overexpressed in most of the cervical cancers and whose respective oncoproteins are critical to the induction and maintenance of the malignant phenotype. Other efforts have been focused on antitumor immunotherapy strategies. It is known that during the development of cervical cancer, a cascade of abnormal events is induced, including disruption of cell cycle control, perturbation of antitumor immune response, alteration of gene expression, deregulation of microRNA and cancer stem cell and stemness related markers expression could serve as novel molecular targets for reliable diagnosis and treatment of HPV-positive cancers. However, the search for new proposals for disease control and prevention has brought new findings and approaches in the context of molecular biology indicating innovations and perspectives in the early detection and prevention of the disease. Thus, in this article, we discuss molecular signaling pathways activated by HPV and potential targets or biomarkers for early detection or prevention and the treatment of HPV-associated cancers.  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