根据基因表达谱与基因功能模块研究大鼠抑郁症发病的分子机制

用Willner法构造大鼠抑郁症模型,由基因芯片检测8例模型和8例正常大鼠的基因表达谱,识别差异表达基因,寻找差异表达基因功能模块并构建基因表达相关网络,研究大鼠抑郁症模型的分子病理机制.在基因本体(GO)功能体系中寻找显著富集差异表达基因的疾病相关功能模块,提取疾病相关功能模块中的基因构造表达相关网络.从中选择显著多地与其它基因共表达的基因定义为HUB基因,并进一步研究其与疾病的关系.筛选得到207个差异表达基因及13个差异表达基因功能模块,主要涉及神经肽激素活性、信号传导通路、核糖体生成以及蛋白质转运与降解.在共表达相关网络中进一步识别了4个差异表达的HUB基因.利用基因功能模块和表达相关网络研究疾病机制的结果显示,抑郁症的发病可能涉及单胺递质的释放、信号传导以及神经肽激素调节等通路协同作用.     

功能化氧化石墨烯载带荧光探针检测白血病细胞(英文)

分别以细胞外实验和和细胞内实验来观察功能化氧化石墨烯(GO)对急性早幼粒细胞白血病细胞株NB4细胞的检测情况。通过比较不同探针浓度、温度、孵育时间等因素,探索最佳条件。结果表明,在室温下,GO吸附200 nmol/L单链DNA荧光探针,并淬灭其荧光;当与含靶分子(PM L/RARα融合基因)的NB4细胞共孵育1小时后,探针便脱离GO,荧光得以恢复,从而准确检测出NB4细胞。     

基于三种贝叶斯方法的结核病基因数据挖掘及生物信息学分析

确定结核病易感宿主基因对结核病的治疗与防控起着关键作用,而目前只有少数基因被证实与其相关.本文基于结核病患者外周血单核细胞基因芯片数据集GSE54992,先通过两种基于贝叶斯框架的方法:信息先验性贝叶斯检验和线性模型及经验贝叶斯方法对该数据集进行分析并筛选出正常样本与活动性结核病患者样本之间的差异表达基因,发现了319个被两种方法均识别出的差异表达基因.再利用这些基因对独立验证集GSE83456进行建模,通过朴素贝叶斯分类器验证,得出了较高的分类准确率.最后通过GO功能富集分析和KEGG通路分析,从生物学角度分析了结核病发病的分子机制.该研究突出了三种贝叶斯方法的综合应用在基因数据分析中的重要作用,为发掘结核病特异性生物标志物提出了新的综合策略,为结核病的预防、诊断和治疗提供了重要线索。     

原位聚合氧化石墨烯/聚氨酯复合材料及其性能研究

将氧化石墨烯(GO)通过超声破碎的方法分散在丙二醇甲醚醋酸酯(PMA)中,采用逐步原位聚合的方法将GO参与聚氨酯(PU)的合成反应。将GO片层状态接枝到PU链段当中,制得PU/GO复合材料,并对复合材料的结构进行了表征。实验结果表明:GO与PU进行交联反应并且在基体内分散均匀,在GO添加量为7份条件下,制得的PU/GO复合材料的断裂伸长率达到49.0%,拉伸强度达到28.0MPa,储能模量达到5.08MPa(在130℃条件下),交联密度达到5.05×10~(-4) mol/cm~3,300℃时失重率达到60%,48h吸水率仅为0.3%,具有较好的力学性能、热稳定性能和耐水性能。     

在线考试及分析系统数据库的分析与设计

设计并分析在线考试及分析系统数据库,该系统严格按照软件工程的模式来进行设计,使用ASP.net技术并采用Macromedia Dreamweaver 2004作为设计工具,后台的数据库使用SQL server 2000创建,并使用了ADO方法来访问数据库,实现教师在线出题,学生在线考试,系统自动评分、成绩分析等功能。     

高空间分辨率的出现电势谱

在PHI-590型扫描俄歇微探针上扩展了出现电势谱的测量功能,此出现电势谱具有上靶电子束流小(几个微安)、空间分辨率高(小于一个微米)的特点,并可用在线计算机控制测量过程。     

聚苯胺修饰石墨烯薄膜的制备与性能研究

采用导电高分子聚苯胺链段作为导电通路,通过添加少量苯胺单体对氧化石墨烯(GO)进行接枝、聚合,再通过氢碘酸还原的方式制备出聚苯胺修饰石墨烯薄膜材料。采用红外光谱、紫外可见吸收光谱、扫描电镜及透射电镜对复合物的官能团及结构变化属性进行表征分析,使用方块电阻仪对复合物的电学性能进行了测试与表征。结果表明:石墨原料经改进的Hummers法制得的GO含有大量的含氧官能团,以及较大的层间距。采用氢碘酸对聚苯胺修饰的GO进行还原处理,得到了具有较好导电能力的聚苯胺/石墨烯薄膜,其方块电阻只有12Ω/。     

氧化石墨烯/聚乙二醇复合材料在人工关节材料上的润滑性能

通过销盘试验分析氧化石墨烯(GO)、聚乙二醇(PEG)和不同比例的GO/PEG复合材料的摩擦学性能,考察GO增强PEG在人工关节材料UHMWPE-CoCrMo配副上的润滑效果,并利用FTIR、XRD、拉曼光谱等研究了GO/PEG复合材料的结构和性能。结果表明:混合比例为0.85wt%GO与40wt%PEG的GO/PEG复合材料在4.2 MPa加载载荷、0.024m/s的滑动速度条件下,平均摩擦系数为0.015,具有良好的润滑效果;GO均匀地分散在PEG溶液中,组分间较强的界面相互作用协同增强了GO/PEG复合材料的润滑性能。     

不同氧化程度氧化石墨烯/聚乙烯醇气凝胶对亚甲基蓝的吸附

氧化石墨烯(GO)对水中染料有着优异的吸附性能,但其氧化程度对复合材料吸附性能和机制的影响还未被充分研究。采用Hummer法,制备3种不同氧化程度的氧化石墨烯,与聚乙烯醇(PVA)复合得到三种GO/PVA气凝胶。利用红外光谱(FTIR)、元素分析(EA)和热重分析(TG)分析了3种GO的氧化程度;以亚甲基蓝(MB)为模拟污染物,通过静态吸附实验考察了GO氧化程度对GO/PVA气凝胶在不同溶液pH、吸附时间、初始浓度下对MB吸附性能的影响。通过吸附动力学模型、吸附等温线模型和吸附热力学模型探究了GO氧化程度对GO/PVA气凝胶吸附机制的影响。研究结果表明:GO/PVA气凝胶对MB的吸附行为受pH影响较小;提高GO的氧化程度可以明显提升GO/PVA气凝胶的吸附容量和吸附速度,GO氧化程度的提高增加了气凝胶上的吸附位点,有利于吸附。此外,GO氧化程度对GO/PVA气凝胶的吸附机制无明显影响。      

在线材料数据库进展与NIMS/MatWeb案例研究EI北大核心CSCD

在线材料数据库是现代信息技术背景下产生的获取信息的新模式,在新材料设计、材料选择、决策咨询等方面应用广泛。能够及时掌握在线材料数据库新动态,准确、高效利用在线材料数据库进行科学研究与工程应用研究尤为重要。本文介绍了在线材料数据库的最新进展,并以NIMS和MatWeb国际著名在线材料数据库为例,从数据服务内容、检索功能、检索结果的处理等方面进行分析与对比,以期对科研人员准确选择以及高效利用在线材料数据库提供帮助。未来在线材料数据库的发展趋势为:Web集成一站式服务,数据类型更多、数据规模更大、数据更规范,基于数据库的衍生信息服务更完善。     

Identify signature regulatory network for glioblastoma prognosis by integrative mRNA and miRNA co‐expression analysis

Glioblastoma multiforme (GBM) is the most common and aggressive type of primary brain tumor in adults. Patients with this disease have a poor prognosis. The objective of this study is to identify survival‐related individual genes (or miRNAs) and miRNA ‐mRNA pairs in GBM using a multi‐step approach. First, the weighted gene co‐expression network analysis and survival analysis are applied to identify survival‐related modules from mRNA and miRNA expression profiles, respectively. Subsequently, the role of individual genes (or miRNAs) within these modules in GBM prognosis are highlighted using survival analysis. Finally, the integration analysis of miRNA and mRNA expression as well as miRNA target prediction is used to identify survival‐related miRNA ‐mRNA regulatory network. In this study, five genes and two miRNA modules that significantly correlated to patient''s survival. In addition, many individual genes (or miRNAs) assigned to these modules were found to be closely linked with survival. For instance, increased expression of neuropilin‐1 gene (a member of module turquoise) indicated poor prognosis for patients and a group of miRNA ‐mRNA regulatory networks that comprised 38 survival‐related miRNA ‐mRNA pairs. These findings provide a new insight into the underlying molecular regulatory mechanisms of GBM.Inspec keywords: RNA, molecular biophysics, genetics, cancerOther keywords: signature regulatory network, glioblastoma prognosis, mRNA coexpression analysis, miRNA coexpression analysis, glioblastoma multiforme, brain tumour, microRNAs, pathogenesis, genome‐wide regulatory networks, miRNA‐mRNA pairs, weighted gene coexpression network analysis, survival analysis, GBM prognosis, integration analysis, neuropilin‐1 gene, module turquoise, molecular regulatory mechanisms     

Direct Quantification of MicroRNA at Low Picomolar Level in Sera of Glioma Patients Using a Competitive Hybridization Followed by Amplified Voltammetric Detection

MicroRNAs (miRNAs), acting as oncogenes or tumor suppressors in humans, play a key role in regulating gene expression and are believed to be important for developing novel therapeutic treatments and clinical prognoses. Due to their short lengths (17-25 nucleotides) and extremely low concentrations (typically < picomolar) in biological samples, quantification of miRNAs has been challenging to conventional biochemical methods, such as Northern blotting, microarray, and quantitative polymerase chain reaction (qPCR). In this work, a biotinylated miRNA (biotin-miRNA) whose sequence is the same as that of a miRNA target is introduced into samples of interest and allowed to compete with the miRNA target for the oligonucleotide (ODN) probe preimmobilized onto an electrode. Voltammetric quantification of the miRNA target was accomplished after complexation of the biotin-miRNA with ferrocene (Fc)-capped gold nanoparticle/streptavidin conjugates. The Fc oxidation current was found to be inversely proportional to the concentration of target miRNA between 10 fM and 2.0 pM. The method is highly reproducible (relative standard deviation (RSD) < 5%), regenerable (at least 8 regeneration/assay cycles without discernible signal decrease), and selective (with sequence specificity down to a single nucleotide mismatch). The low detection levels (10 fM or 0.1 attomoles of miRNA in a 10 μL solution) allow the direct quantification of miRNA-182, a marker correlated to the progression of glioma in patients, to be performed in serum samples without sample pretreatment and RNA extraction and enrichment. The concentration of miRNA-182 in glioma patients was found to be 3.1 times as high as that in healthy persons, a conclusion in excellent agreement with a separate qPCR measurement of the expression level. The obviations of the requirement of an internal reference in qPCR, simplicity, and cost-effectiveness are other additional advantages of this method for detection of nucleic acids in clinical samples.     

Constructing and characterizing a bioactive small molecule and microRNA association network for Alzheimer's disease

Alzheimer''s disease (AD) is an incurable neurodegenerative disorder. Much effort has been devoted to developing effective therapeutic agents. Recently, targeting microRNAs (miRNAs) with small molecules has become a novel therapy for human diseases. In this study, we present a systematic computational approach to construct a bioactive Small molecule and miRNA association Network in AD (SmiRN-AD), which is based on the gene expression signatures of bioactive small molecule perturbation and AD-related miRNA regulation. We also performed topological and functional analysis of the SmiRN-AD from multiple perspectives. At the significance level of p ≤ 0.01, 496 small molecule–miRNA associations, including 25 AD-related miRNAs and 275 small molecules, were recognized and used to construct the SmiRN-AD. The drugs that were connected with the same miRNA tended to share common drug targets (p = 1.72 × 10⁻⁴) and belong to the same therapeutic category (p = 4.22 × 10⁻⁸). The miRNAs that were linked to the same small molecule regulated more common miRNA targets (p = 6.07 × 10⁻³). Further analysis of the positive connections (quinostatin and miR-148b, amantadine and miR-15a) and the negative connections (melatonin and miR-30e-5p) indicated that our large-scale predictions afforded specific biological insights into AD pathogenesis and therapy. This study proposes a holistic strategy for deciphering the associations between small molecules and miRNAs in AD, which may be helpful for developing a novel effective miRNA-associated therapeutic strategy for AD. A comprehensive database for the SmiRN-AD and the differential expression patterns of the miRNA targets in AD is freely available at http://bioinfo.hrbmu.edu.cn/SmiRN-AD/.     

Cross-analysis of hazmat road accidents using multiple databases

Road selection for hazardous materials transportation relies heavily on risk analysis. With risk being generally expressed as a product of the probability of occurrence and the expected consequence, one will understand that risk analysis is data intensive. However, various authors have noticed the lack of statistical reliability of hazmat accident databases due to the systematic underreporting of such events. Also, official accident databases alone are not always providing all the information required (economical impact, road conditions, etc.). In this paper, we attempt to integrate many data sources to analyze hazmat accidents in the province of Quebec, Canada. Databases on dangerous goods accidents, road accidents and work accidents were cross-analyzed. Results show that accidents can hardly be matched and that these databases suffer from underreporting. Police records seem to have better coverage than official records maintained by hazmat authorities. Serious accidents are missing from government's official databases (some involving deaths or major spills) even though their declaration is mandatory.     

Monitoring multivariate aviation safety data by data depth: control charts and threshold systems

Aviation safety analysis is increasingly needed in regulating air traffic and safety, in light of the rapid growth in air traffic density. With the recent advances in computer technology, large amounts of multivariate aviation safety data are now routinely collected in databases. Many existing analysis methods prescribed in those databases and corresponding safety indictors are based on classical statistical analysis, and their applicability are considerably restricted by the requirement of normality. An alternative nonparametric methodology based on data depth is pursued in this paper. For a given multivariate sample, a data depth can be used to measure their depth or outlyingness with respect to the underlying distribution. The measure of depth leads to a center-outward ordering of the sample points. Derived from this ordering, Liu (1995) introduced a simple, yet effective, control chart for monitoring multivariate observations. The control chart is combined here with properly chosen false alarm rates to develop meaningful threshold systems for multivariate aviation safety data for both regulating and monitoring purposes. The developed procedure is applied to the aviation inspection results collected by the Federal Aviation Administration (FAA) inspection system. The threshold system serves as a standard for evaluating the performance of aircraft operators, and provides clear guidelines for identifying unexpected performances and for assigning appropriate corrective actions.     

Mo base superconducting materials prepared by multi-target reactive sputtering

With an aim of developing new types of superconducting materials, Mo-N films and Mo/Si multi-layered films were fabricated by reactive and two-target sputtering methods, respectively. The superconducting properties such as Tc, Hc2and Jcwere examined. The crystal structure of Mo-N films changed from bcc to fcc with increasing N2gas flow rate during sputtering and a homogeneous fcc Mo2N superconductor was obtained. On the other hand, the superconducting characteristics of the Mo/Si multi-layered film with a layer spacing 32.3 Å were confirmed to be similar to those of amorphous Mo-Si alloys except the occurrence of anisotropic vortex pinning.     

Exosomal miRNA Profiling to Identify Nanoparticle Phagocytic Mechanisms

Inhaling a dangerous amount of nanoparticles leads to pulmonary inflammatory and immune disorders, which integrates several kinds of cells. Exosomes are suggested to play a crucial role in intercellular communication via miRNA transmission. To investigate the role of exosomal miRNA in nanoparticle phagocytosis, a total of 54 pneumoconiosis patients along with 100 healthy controls are recruited, exosomes derived from their venous blood are collected, and then exosomal miRNAs are profiled with high‐throughput sequencing technology. miRNAs which are differentially expressed are used to predict target genes and conduct functional annotation. Interactions between miRNA hsa‐let‐7a‐5p, hsa‐let‐7i‐5p, and their cotarget gene WASL are found that can affect nanoparticle phagocytosis. The follow‐up analysis of gene structure, tissue specificity, and miRNA‐target gene regulatory mode supports the findings. Specially, the assumption is further confirmed via a series of cellular experiments, and the fibroblast transdifferentiate rate that is used as an indicator of nanoparticle phagocytosis decreased when elevating miRNA expression level. Thus, data in this study indicate that downregulation of miRNA hsa‐let‐7a‐5p and hsa‐let‐7i‐5p contributes to WASL elevation, promoting WASL and VASP complex formation, which is necessary for initiating Arp2/3 induced phagocytosis.     

Aging processes in thin radio-frequency sputtered zinc films

Thin zinc films with thicknesses ranging between 200 and 1100 Å were radio- frequency sputtered onto Vycor substrates at 293 K. Thermal aging induces a decrease in resistivity between 300 and 385 K. A kinetic analysis of the isothermal resistance recovery showed that the resistance decay is a first-order process and that two distinct temperature regions with different activation energies appear. At “low” temperatures the activation energy is 0.17 eV, suggesting a surface reordering. At “high” temperatures the activation energy increases from 0.4 to 0.64 eV with increasing thickness; the resistance recovery is attributed to a grain boundary diffusion process. These interpretations are in good agreement with the occurrence of Mayadas-Shatzkes conduction in these polycrystalline films with a constant average grain size.     

Scanning an individual monitoring database for multiple occurrences using bi-gram analysis

Maintaining the integrity of the databases is one of the important aspects of quality assurance at individual monitoring services and national dose registers. This paper presents a method for finding and preventing the occurrence of duplicate entries in the databases that can occur, e.g. because of a variable spelling or misspelling of the name. The method is based on bi-gram text analysis techniques. The methods can also be used for retrieving dose data in historical databases in the framework of dose reconstruction efforts of persons of whom the spelling of the name as originally entered, possibly decades ago, is uncertain.