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Squamous cell carcinoma (SCC) occurring in the head and neck region and the esophagus causes tremendous cancer mortality around the world. miR‐31 is among the most eminently upregulated MicroRNAs in SCC, when it occurs in the head and neck region and the esophagus. We established miR‐31 transgenic mouse lines, in which miR‐31 is under the control of the K14 promoter. 4‐nitroquinoline 1‐oxide (4NQO) is a mutagen that causes double strand breaks. The transgenic mice exhibited a higher potential for tumor induction than wild‐type (Wt) mice of the tongue and esophagus after 4NQO treatment. After 4NQO treatment or irradiation, p‐γH2AX expression in squamous epithelium of transgenic mice was increased more than in Wt mice. Exogenous expression of miR‐31 was also found to be associated with the higher p‐γH2AX expression induced by 4NQO in human oral SCC (OSCC) cell lines. The repair genes PARP1 and Ku80 were validated as new targets of miR‐31 in human OSCC cell lines, and were found to be downregulated in the squamous epithelium of the tongue in transgenic mice. However, only the downregulation of Ku80 was essential for maintaining the high level of p‐γH2AX induced by 4NQO in OSCC cells. Inverse expression profiles for miR‐31 and Ku80 were noted in human OSCC tissue. Our study identifies the high sensitivity of K14‐EGFP‐miR‐31 transgenic mice to chemical carcinogen‐induced squamous cell tumorigenesis and shows that this seems to be associated with the downregulation of Ku80 and an impairment of repair activity in squamous cells, which are mediated by miR‐31.  相似文献   
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MicroRNAs (miRNAs) regulate a wide range of cellular signaling pathways and biological processes in both physiological and pathological states such as cancer. We have previously identified miR‐135b as a direct regulator of androgen receptor (AR) protein level in prostate cancer (PCa). We wanted to further explore the relationship of miR‐135b to hormonal receptors, particularly estrogen receptor α (ERα). Here we show that miR‐135b expression is lower in ERα‐positive breast tumors as compared to ERα‐negative samples in two independent breast cancer (BCa) patient cohorts (101 and 1302 samples). Additionally, the miR‐135b expression is higher in AR‐low PCa patient samples (47 samples). We identify ERα as a novel miR‐135b target by demonstrating miR‐135b binding to the 3′UTR of the ERα and decreased ERα protein and mRNA level upon miR‐135b overexpression in BCa cells. MiR‐135b reduces proliferation of ERα‐positive BCa cells MCF‐7 and BT‐474 as well as AR‐positive PCa cells LNCaP and 22Rv1 when grown in 2D. To identify other genes regulated by miR‐135b we performed gene expression studies and found a link to the hypoxia inducible factor 1α (HIF1α) pathway. We show that miR‐135b influences the protein level of the inhibitor for hypoxia inducible factor 1α (HIF1AN) and is able to bind to HIF1AN 3′UTR. Our study demonstrates that miR‐135b regulates ERα, AR and HIF1AN protein levels through interaction with their 3′UTR regions, and proliferation in ERα‐positive BCa and AR‐positive PCa cells.  相似文献   
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Colorectal cancer (CRC) is one of the most common malignancies worldwide. The prognosis for this cancer is poor, and the development of novel biomarkers, particularly non-invasive surrogate biomarkers, is urgently needed. Recent studies have demonstrated that microRNAs (miRNAs) are stably detectable in the blood and can serve as useful biomarkers for various types of cancer. In this study, the miR-183 expression levels were found to be significantly overexpressed in plasma samples from CRC patients compared with controls, and the postoperative plasma miR-183 levels were significantly reduced compared with the preoperative levels. The value of the area under the receiver operating characteristic (ROC) curve obtained for miR-183 was 0.829, which was higher than those for carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9). High plasma miR-183 expression was significantly associated with lymph node metastasis, distant metastasis, higher pTNM stage (III-IV), and tumor recurrence. CRC patients with elevated miR-183 expression in plasma displayed shorter disease-free survival (DFS) and lower overall survival (OS). More importantly, plasma miR-183 was independently correlated with tumor recurrence and a lower OS. Collectively, our results suggested that the elevated miR-183 in the plasma could be a promising biomarker for predicting the risk of tumor recurrence and poor survival in CRC patients.  相似文献   
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目的 探讨卵巢癌患者血浆miR-205、miR-212及miR-429水平,分析3者与卵巢癌临床病理学特征的关系。方法 收集本院收治的71例上皮性卵巢癌患者未经治疗前的血浆标本(上皮性卵巢癌组),采用实时定量RT-PCR(qRT-PCR)法检测以上标本的miR-205、miR-212及miR-429水平,收集卵巢癌患者的临床病理学参数(年龄、临床分期、分化程度、组织类型及淋巴结转移情况),比较不同miR-205、miR-212及miR-429水平的临床病理参数分布差异,采用受试者工作特征曲线(ROC)评价血浆miR-205、miR-212及miR-429水平在卵巢癌诊断中的临床价值。同时选取同期的68例女性健康体检者(健康对照组)及66例良性卵巢肿瘤患者(良性卵巢肿瘤组)的血浆标本作对照。结果 上皮性卵巢癌组的血浆miR-205水平高于良性卵巢肿瘤组和健康对照组,但miR-212和miR-429水平低于良性卵巢肿瘤组和健康对照组,差异均有统计学意义(P<0.05);上皮性卵巢癌组中的miR-205水平与年龄、临床分期、分化程度及淋巴结转移有关,miR-212水平与临床分期、分化程度有关,miR-429水平与临床分期、淋巴结转移有关,以上差异均有统计学意义(P<0.05);卵巢癌患者血浆miR-205水平与miR-212及miR-429均呈负相关(r=-0.572、-0.325),miR-212与miR-429呈正相关(r=0.473),差异均有统计学意义(P<0.05);血浆miR-205、miR-212及miR-429诊断卵巢癌的AUC、灵敏度和特异度分别为0.915、92.1%和86.2%,0.944,87.3%和91.0%,0.905、88.5%和83.6%。结论 卵巢癌患者血浆中miR-205呈高表达,miR-212和miR-429呈低表达,与临床病理学参数有关,且在卵巢癌诊断中有一定的价值,可用于卵巢癌的辅助诊断和病情评估。  相似文献   
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AIM:To evaluate the biological and clinical characteristics of miR-622 in gastric cancer. METHODS:We analyzed the expression of miR-622 in 57 pair matched gastric neoplastic and adjacent non-neoplastic tissues by quantitative real-time polymerase chain reaction. Functional analysis of miR-622 expression was assessed in vitro in gastric cancer cell lines with miR-622 precursor and inhibitor. The roles of miR-622 in tumorigenesis and tumor metastasis were analyzed using a stable miR-622 expression plasmid in ...  相似文献   
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目的:探讨microRNA-340(miR-340)对施万细胞纤溶能力的调控作用及作用的靶基因。方法:采用溶圈实验来检测miR-340对施万细胞纤溶能力的影响,用荧光素酶双报告基因系统确定miR-340与组织型纤溶酶原激活剂的靶向关系,用实时定量聚合酶链反应检测坐骨神经夹伤后组织型纤溶酶原激活剂mRNA和miR-340的表达变化。结果:miR-340能够抑制施万细胞的纤溶能力,并直接靶向作用于组织型纤溶酶原激活剂的3’UTR,坐骨神经夹伤后组织型纤溶酶原激活剂mRNA与miR-340的表达呈负相关性。结论:miR-340通过直接靶向组织型纤溶酶原激活剂的3’UTR,从而下调靶基因组织型纤溶酶原激活剂的表达抑制施万细胞的纤溶能力。  相似文献   
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目的探讨miRNA-449a在肺癌组织中的表达及其临床应用价值。方法收集右江族医学院附属医院2011年1月1日~2013年6月30日收治的58例肺癌患者为研究对象,采用反转录荧光定量聚合酶链式反应(RT-PCR)检测miRNA-449a在肺癌组织和癌旁正常组织中的表达量,分析miRNA-449a与临床病理特征的关系,并采用荧光电子显微镜观察miRNA-449a模拟物对体外培养肺癌细胞株95D细胞凋亡的影响。结果鳞癌组和腺癌组miRNA-449a平均表达量均明显低于癌旁正常对照组(LSD-t=6.712,P=0.000;LSD-t=4.572,P=0.000),其相对表达量与瘤体大小(u=78.412,P=0.012)有关,与患者年龄(u=920.000,P=0.615)、性别(u=800.000,P=0.215)、病理类型(χ2=4.221,P=0.155)和临床分期(u=754.000,P=0.009)无关。与阴性对照组比较,miRNA-449a模拟物可明显促进肺癌细胞的凋亡,且呈剂量依赖性。结论 miRNA-449a在肺癌组织中呈低表达,可诱导肺癌细胞凋亡,发挥抑癌基因的作用,可能成为肺癌早期诊断与治疗的新分子靶标。  相似文献   
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Antidepressant efficacy is insufficient, unpredictable and poorly understood in major depressive episode (MDE). Gene expression studies allow for the identification of significantly dysregulated genes but can limit the exploration of biological pathways. In the present study, we proposed a gene coexpression analysis to investigate biological pathways associated with treatment response predisposition and their regulation by microRNAs (miRNAs) in peripheral blood samples of MDE and healthy control subjects. We used a discovery cohort that included 34 MDE patients that were given 12-week treatment with citalopram and 33 healthy controls. Two replication cohorts with similar design were also analyzed. Expression-based gene network was built to define clusters of highly correlated sets of genes, called modules. Association between each module’s first principal component of the expression data and clinical improvement was tested in the three cohorts. We conducted gene ontology analysis and miRNA prediction based on the module gene list. Nine of the 59 modules from the gene coexpression network were associated with clinical improvement. The association was partially replicated in other cohorts. Gene ontology analysis demonstrated that 4 modules were associated with cytokine production, acute inflammatory response or IL-8 functions. Finally, we found 414 miRNAs that may regulate one or several modules associated with clinical improvement. By contrast, only 12 miRNAs were predicted to specifically regulate modules unrelated to clinical improvement. Our gene coexpression analysis underlines the importance of inflammation-related pathways and the involvement of a large miRNA program as biological processes predisposing associated with antidepressant response.  相似文献   
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