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51.
目的探讨6个微小RNA(microRNA)多态性位点(rs11614913,microRNA-196a2;rs3746444,hsa-mir-499;rs2910164,microRNA-146a;rs2292832,microRNA-149;rs6505162,microRNA-423;rs895819,microRNA-27a)与中国女性乳腺癌发病风险及病理特征的相关性。方法采用病例对照研究,选取350例乳腺癌患者为病例组及350名正常女性为对照组,采用Massarray SNP技术检测6个多态性位点的基因型,采用免疫组化法检测乳腺癌组织中的雌激素受体及孕激素受体表达,分析各基因型与乳腺癌发生的关系及与乳腺癌病理参数的关系。结果 rs3746444GG基因型在病例组中(OR=1.71,95%CI:1.16~2.52)的频率显著高于对照组。分层分析结果显示,在绝经后的人群中,rs3746444GG基因型病例组中的频率(OR=2.19,95%CI:1.16~4.15)显著高于对照组。rs3746444GG基因型在肿瘤分期0~Ⅱ组(OR=1.92,95%CI:1.17~3.13)、淋巴结转移组(OR=2.20,95%CI:1.28~3.79)、孕激素受体阴性组中(OR=2.19,95%CI:1.25~3.82)分布频率均显著高于正常对照组。在绝经后人群中,rs2910164GG基因型在病例组中(OR=2.19,95%CI:1.16~4.15)的分布频率显著高于对照组。而在绝经前的人群中,rs2910164GG基因型在病例组中(OR=0.49,95%CI:0.25~0.98)的分布频率显著低于对照组。结论rs3746444GG基因型与乳腺癌发病风险相关,特别是在绝经后人群中风险更高。rs2910164GG基因型与乳腺癌的发病风险相关性与妇女是否绝经有关。  相似文献   
52.
[目的]通过研究甲基汞对人胚胎神经干细胞miRNA表达的影响,探讨低剂量甲基汞对神经干细胞细胞周期调控基因的调节作用. [方法]以0、10、50 nmol/L甲基汞染毒人胚胎神经干细胞24h后,用MTT法测定甲基汞对细胞活力影响,应用逆转录多聚酶链反应(RT-PCR)检测甲基汞对细胞周期调控基因(p16、p21)的mRNA的表达水平影响,利用实时荧光定量多聚酶链反应技术检测调控p16、p21的miRNA(miR-24、miR-106a)的表达情况. [结果]50 nmol/L甲基汞染毒组细胞活力降低为对照组的53.5%,差异有统计学意义(P<0.05);p16与p21基因的mRNA表达水平随着甲基汞染毒浓度的升高而升高,差异均有统计学意义(P<0.05),但10 nmol/L与50 nmol/L组的p16基因表达差异无统计学意义.miR-24、miR-106a的表达水平随着甲基汞染毒浓度的升高而降低,差异有统计学意义(P<0.05). [结论]50 nmol/L的甲基汞可以引起人胚胎神经干细胞增殖抑制,并可能通过miRNA调节细胞周期调控基因的表达.  相似文献   
53.
microRNA(miRNA)作为一类微小非编码RNA,通过RNA干扰(RNAi)信号通路来调控基因表达,在机体发育和疾病中发挥重要作用。基于此,本文一方面揭示miRNA在斑马鱼和小鼠的内耳发育过程中的表达状况和其重要作用,以此外推其在人类内耳中的功能;另一方面阐述了miRNA参与调控听力损失相关疾病表型中的最新进展,为探索如何更好地预防听力损失的发生及改善预后提供新的线索。  相似文献   
54.
55.
On activation platelets release microRNAs and extracellular vesicles (EV) into circulation. The release of EV from platelets has been shown to be dependent on the agonist; in this study, we investigated whether the microRNA profile or EV released from platelets was also agonist specific.

Washed platelets from healthy subjects were maximally stimulated with agonists specific for the receptors for collagen (Glycoprotein VI (GPVI)), thrombin (PAR1/PAR4), or ADP (P2Y1/P2Y12) with/without inhibiting secondary mediators, using aspirin to block cyclooxygenase-1 and apyrase to remove ADP. The released microRNAs were profiled using TaqMan microRNA microarray cards. Platelet-derived EV (pdEV) were characterized by size (Nanoparticle Tracking Analysis, NTA), for procoagulant activity (Annexin-V binding and support of thrombin generation), and for the EV markers CD63 and HSP70.

Platelet activation triggered the release of 57–79 different microRNAs, dependent upon agonist, with a core of 46 microRNAs observed with all agonists. There was a high level of correlation between agonists (r2 > 0.98; p < 0.0001 for all), and with the microRNA content of the parent platelets (r2 > 0.98; p < 0.0001). The 46 microRNAs seen in all samples are predicted to have significant effects on the translation of proteins involved in endocytosis, cell cycle control, and differentiation. MiR-223-3p was the most abundant in all samples and has previously been implicated in myeloid lineage development and demonstrated to have anti-inflammatory effects. Stimulation through GPVI produced a pdEV population with significantly more procoagulant activity than the other agonists. Apyrase significantly reduced microRNA and pdEV release, while aspirin had little effect.

These data suggest that all tested agonists trigger the release of a similar microRNA profile while the procoagulant activity of the pdEV was agonist dependent. ADP was shown to play an important role in the release of both microRNAs and pdEV.  相似文献   

56.
心肌梗死后容易发生心衰、恶性心律失常甚至猝死等而威胁患者生命,有效改善心梗患者心功能促进心肌再生已经成为研究的热点。目前促进心肌再生的方法可大体概括为干细胞法诱导心肌增殖,微小核糖核酸诱导心肌再生,调控心肌细胞增殖有关的通路及细胞周期因子诱导心肌增殖,调节心肌细胞微环境诱导心肌增殖。虽然这些方法的研究都取得了一定的进展,但许多机制并未明确,也有诸多问题没有解决,还需要更深入的研究,随着心脏再生的研究,这一领域必将带来振奋人心的结果。  相似文献   
57.
目的研究双酚A对小鼠睾丸间质细胞的毒性作用,及对miR-203-3p和PI3K/AKT/FOXO1信号通路的影响。方法不同浓度BPA(0、2、10、50、250μmol/L)处理小鼠睾丸间质细胞24 h,CCK8法检测细胞活力,Real time PCR检测miR-203-3p和FOXO1、AKT、PI3K的相对表达水平。结果不同浓度BPA处理细胞后,细胞活力随BPA剂量的增大而减少,50、250μmol/L组与对照组比较,差异有统计学意义(P<0.001)。各处理组miR-203-3p表达量均较对照组升高,10、250μmol/L组与对照组比较,差异有统计学意义(P<0.05)。2、10μmol/L组FOXO1表达量较对照组升高,50、250μmol/L组表达量较对照组降低,2、50、250μmol/L组FOXO1相对表达量与对照组比较差异有统计学意义(P<0.001)。各处理组AKT水平均出现下降趋势,10、50、250μmol/L组与对照组比较,差异有统计学意义(P<0.001)。各处理组PI3K水平均出现下降趋势,50、250μmol/L组与对照组比较,差异有统计学意义(P<0.001)。结论双酚A致睾丸间质细胞损伤,影响miR-203-3p和FOXO信号通路相关基因的改变。  相似文献   
58.
A subset of human breast cancer cell lines exhibits aberrant DNA hypermethylation that is characterized by hyperactivity of the DNA methyltransferase enzymes, overexpression of DNMT3b, and concurrent methylation-dependent silencing of numerous epigenetic biomarker genes. The objective of this study was to determine if this aberrant DNA hypermethylation (i) is found in primary breast cancers, (ii) is associated with specific breast cancer molecular subtypes, and (iii) influences patient outcomes. Analysis of epigenetic biomarker genes (CDH1, CEACAM6, CST6, ESR1, GNA11, MUC1, MYB, SCNN1A, and TFF3) identified a gene expression signature characterized by reduced expression levels or loss of expression among a cohort of primary breast cancers. The breast cancers that express this gene expression signature are enriched for triple-negative subtypes — basal-like and claudin-low breast cancers. Methylation analysis of primary breast cancers showed extensive promoter hypermethylation of epigenetic biomarker genes among triple-negative breast cancers, compared to other breast cancer subclasses where promoter hypermethylation events were less frequent. Furthermore, triple-negative breast cancers either did not express or expressed significantly reduced levels of protein corresponding to methylation-sensitive biomarker gene products. Together, these findings suggest strongly that loss of epigenetic biomarker gene expression is frequently associated with gene promoter hypermethylation events. We propose that aberrant DNA hypermethylation is a common characteristic of triple-negative breast cancers and may represent a fundamental biological property of basal-like and claudin-low breast cancers. Kaplan–Meier analysis of relapse-free survival revealed a survival disadvantage for patients with breast cancers that exhibit aberrant DNA hypermethylation. Identification of this distinguishing trait among triple-negative breast cancers forms the basis for development of new rational therapies that target the epigenome in patients with basal-like and claudin-low breast cancers.  相似文献   
59.
60.
《Autoimmunity》2013,46(5):327-333
Abstract

MicroRNAs (miRNAs) are important regulators of gene expression and translation. The genetic variants altering miRNA targets have been associated with many diseases. Here we systematically mapped the human genetic polymorphisms that may affect miRNA–mRNA interactions in the autoimmune thyroid disease (AITD) pathway. We also mapped the polymorphic miRNA target sites in the genes that have been linked to AITDs or other thyroid-related diseases/phenotypes in genome-wide association studies (GWAS). These genetic polymorphisms may potentially contribute to the pathogenesis of AITDs and other thyroid diseases. The polymorphic miRNA–mRNA interactions we mapped in the AITD pathway and the GWAS-informed thyroid disease loci may provide insights into the possible miRNA-mediated molecular mechanisms through which genetic variants assert their influences on thyroid diseases and phenotypes.  相似文献   
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