便携式多气体检测仪设计

介绍一种便携式多气体检测仪的设计方案,使用PIC18LF6620作为核心处理器,同时连续检测O2、CO、H2S、CH4四种气体的浓度。详细介绍了气体传感器工作原理及其信号处理电路。经过实际测试,该检测仪具有体积小、重量轻、灵敏度高、响应速度快、测量精确等优点。     

H181成型磨床改进

本文介绍了活塞环H181成型磨床由液压进给改进方式为数控进给方式，包括：砂轮修整部分和磨削进给部分。     

miR-181b promotes the oncogenesis of renal cell carcinoma by targeting TIMP3

Renal cell carcinoma (RCC) has a poor prognosis due to limited diagnosis and treatment. Thus, it is necessary to find novel prognostic biomarkers and therapeutic targets. The aberrant expression of microRNAs plays an important role in RCC oncogenesis. Tissue inhibitors of metalloproteinase 3 (TIMP3) acts as a downstream target of miR-181b. The aim of this study was to understand the role and molecular mechanism of miR-181b in RCC oncogenesis. The results showed that miR-181b expression was significantly higher in RCC tumour tissues, especially in those with significant invasion or metastasis. miR-181b overexpression promoted proliferation and migration of the RCC cell line 786-O, while miR-181b knockdown had the opposite effect. In addition, miR-181b was inversely correlated with TIMP3 expression in RCC tumour tissues. miR-181b overexpression reduced TIMP3 expression in RCC cell line 786-O or OS-RC-2, while miR-181b knockdown had the inverse effect. Mechanistically, a luciferase reporter assay confirmed the binding sites of miR-181b on the 3’-UTR of TIMP3, confirming the targeting effect of miR-181b on TIMP3. Overall, miR-181b promotes the development and progression of RCC by targeting TIMP3 expression, indicating the potential use of miR-181b in the diagnosis and treatment of RCC.     

MicroRNA-181a is elevated by 10-hydroxycamptothecin and represses lung carcinoma progression by downregulating FOXP1

Tumor progression is usually characterized by proliferation, migration, and angiogenesis, which is essential for supplying both nutrients and oxygen to the tumor cells. Therefore, targeting angiogenesis has been considered a promising therapeutic strategy for cancer prevention and treatment. In the present study, we demonstrated that in addition to suppressing lung cancer cell proliferation and migration in vitro, 10-hydroxycamptothecin (10-HCPT) is also capable of inhibiting angiogenesis in vivo with a miR-181a-dependent manner. Mechanistically, by upregulating miR-181a, which in turn downregulating FOXP1, 10-HCPT can inhibit the PI3K/Akt/ERK signaling pathwaymediated angiogenesis. Furthermore, reduced levels of miR-181a have been found in both lung cancer cell lines and xenograft with concurrently elevated levels of FOXP1, VEGF, bFGF, and HDGF. Consistent with the findings from the in vitro experiments, miR-181a impairs neovascularization in our xenograft model. In summary, our findings have not only established the anti-oncogenic role of miR-181a in lung cancer angiogenesis but also suggest that 10-HCPT could be a potential therapeutic reagent for lung cancer treatment.     

MicroRNA-378 Alleviates Cerebral Ischemic Injury by Negatively Regulating Apoptosis Executioner Caspase-3

miRNAs have been linked to many human diseases, including ischemic stroke, and are being pursued as clinical diagnostics and therapeutic targets. Among the aberrantly expressed miRNAs in our previous report using large-scale microarray screening, the downregulation of miR-378 in the peri-infarct region of middle cerebral artery occluded (MCAO) mice can be reversed by hypoxic preconditioning (HPC). In this study, the role of miR-378 in the ischemic injury was further explored. We found that miR-378 levels significantly decreased in N2A cells following oxygen-glucose deprivation (OGD) treatment. Overexpression of miR-378 significantly enhanced cell viability, decreased TUNEL-positive cells and the immunoreactivity of cleaved-caspase-3. Conversely, downregulation of miR-378 aggravated OGD-induced apoptosis and ischemic injury. By using bioinformatic algorithms, we discovered that miR-378 may directly bind to the predicted 3′-untranslated region (UTR) of Caspase-3 gene. The protein level of caspase-3 increased significantly upon OGD treatment, and can be downregulated by pri-miR-378 transfection. The luciferase reporter assay confirmed the binding of miR-378 to the 3′-UTR of Caspase-3 mRNA and repressed its translation. In addition, miR-378 agomir decreased cleaved-caspase-3 ratio, reduced infarct volume and neural cell death induced by MCAO. Furthermore, caspase-3 knockdown could reverse anti-miR-378 mediated neuronal injury. Taken together, our data demonstrated that miR-378 attenuated ischemic injury by negatively regulating the apoptosis executioner, caspase-3, providing a potential therapeutic target for ischemic stroke.     

Overexpression of microRNAs miR-25-3p,miR-185-5p and miR-132-3p in Late Onset Fetal Growth Restriction,Validation of Results and Study of the Biochemical Pathways Involved

In a prospective study, 48 fetuses were evaluated with Doppler ultrasound after 34 weeks and classified, according to the cerebroplacental ratio (CPR) and estimated fetal weight (EFW), into fetuses with normal growth and fetuses with late-onset fetal growth restriction (LO-FGR). Overexpression of miRNAs from neonatal cord blood belonging to LO-FGR fetuses, was validated by real-time PCR. In addition, functional characterization of overexpressed miRNAs was performed by analyzing overrepresented pathways, gene ontologies, and prioritization of synergistically working miRNAs. Three miRNAs: miR-25-3p, miR-185-5p and miR-132-3p, were significantly overexpressed in cord blood of LO-FGR fetuses. Pathway and gene ontology analysis revealed over-representation of certain molecular pathways associated with cardiac development and neuron death. In addition, prioritization of synergistically working miRNAs highlighted the importance of miR-185-5p and miR-25-3p in cholesterol efflux and starvation responses associated with LO-FGR phenotypes. Evaluation of miR-25-3p; miR-132-3p and miR-185-5p might serve as molecular biomarkers for the diagnosis and management of LO-FGR; improving the understanding of its influence on adult disease.     

Development of µGC (micro gas chromatography) with high performance micromachined chip column

A micro gas chromatography (µGC) instrument applying a high performance chip column fabricated on a silicon wafer was developed. Experimental results of the chip column and protyping of a µGC instrument are described. Approximately 35 000 theoretical plates were generated with the chip column coated liquid phase (5% phenyl-/95% dimethyl-polysiloxane). The theoretical plates of the chip column were close to those of the capillary column. Experimental minimum height equivalent to a theoretical plate (HETP, H_min) of the chip column was 1.2 times higher than the calculated H_min. A prototype µGC applying the chip column was developed. The µGC generated approximately 35 000 theoretical plates, similar to the theoretical plates obtained by a commercial GC instrument. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

靖边气田陕181—陕400井区奥陶纪古地貌研究

靖边气田是一个与奥陶系海相碳酸盐岩有关的风化壳型气田,陕181-陕400井区是靖边气田扩边建产的重点区,由于前期钻井较少,对古地貌形态尚缺乏详细认识,制约了区块扩边建产进程。结合近年来最新钻井资料,采用残余厚度法对奥陶系古地貌进行刻画,分析了地貌单元与油气富集关系。研究表明,该区存在剥蚀区、台丘、斜坡、沟槽4类地貌单元,其分布规律呈现西部剥蚀区-中部斜坡-东部台丘的特征,台丘和斜坡区是下一步产能建设有利区。     

Evaluation of Neutron Capture Gamma-Ray Spectra in Hafnium and Tantalum

A method has been developed for evaluation of neutron capture γ-ray spectrum. It couples measured intensities of primary and secondary discrete—-ray with a γ-ray cascade model to calculate the unresolved part of the capture spectrum, and adds the discrete part and the unresolved part to obtain the whole spectrum. The cascade model uses the level density formula proposed by Gilbert & Cameron and the Brink & Axel form of El γ-ray profile function with a modification. This method was applied to thermal neutron capture spectra in six hafnium isotopes and ¹⁸¹Ta and was extended also to non-thermal capture spectra in ¹⁸¹Ta for 0.25 and 0.5 MeV neutrons with empirical assumptions. The calculated results were compared with experiments and agreement was good not only in terms of the gross structure, but also in terms of the fine structure which appears at high and low γ-ray energies.