基于ZigBee技术的温湿度监测网络设计与实现

无线传感器网络是当前信息领域中研究的热点之一,可用于特殊环境实现信号的采集、处理和发送。文中介绍了一种基于ZigBee技术的温、湿度监测网络的设计与实现,以CC2430单片机和数字式温、湿度传感器SHT10设计出了温、湿度传感器节点,以AT91R4008微控制器、AX88796以太网控制器芯片和CC2430单片机设计出了ZigBee无线网关。温湿度传感器节点通过射频收发器将数据发送到ZigBee无线网关。ZigBee无线网关通过以太网网络将数据传输给监测中心主机。该系统具有低功耗、高可靠性、易组网及稳定性好等优势,可广泛应用于工业环境温、湿度监测。     

AX.25协议在PIC16F877单片机上的实现

本文介绍了利用AX.25协议构成分组无线网的方案,给出了基于AX.25协议的终端结点控制器的硬件和软件实现方法,讨论了AX.25协议在PIC16F877单片机上的设计与实现。     

矩阵方程X^＊AX=B的反问题

本利用分块矩阵的复正定性。讨论了矩阵方程X^*AX=B的反问题有复正定矩阵解的充要条件，进而给出其解的形式。     

旋转型摇摇棒的制作

以STC89S52单片机为中心,运用C语言和汇编语言相结合的方式,运用串行E2PROMAT24C01实现外部数据储存功能,通过MAX7291数码管驱动芯片实现基于单片机的CAN通信及显示系统。     

氮肥和羊粪对内蒙古典型草原土壤多糖含量及组成的影响

采用三氟乙酸(TFA)水解、糖醇乙酸酯衍生、气相色谱法测定土壤多糖含量,研究了内蒙古羊草草原围栏封育并连续5年施用氮肥和羊粪的表层土壤的多糖含量和组成特征。结果表明:长期施用氮肥显著降低土壤多糖含量6%～19%;施用羊粪显著提高土壤多糖含量20%。施氮肥或羊粪都降低了(半乳糖 甘露糖)(/阿拉伯糖 木糖)(GM/AX)和甘露糖/木糖(M/X)的比例,表明施肥降低了微生物多糖对土壤多糖的贡献,但是施氮肥的土壤降低幅度大于施羊粪的土壤。这表明,长期施氮肥和羊粪都将改变土壤多糖含量和组成。     

β-Catenin-Specific Inhibitor,iCRT14, Promotes BoHV-1 Infection-Induced DNA Damage in Human A549 Lung Adenocarcinoma Cells by Enhancing Viral Protein Expression

Oncolytic bovine herpesvirus type 1 (BoHV-1) infection induces DNA damage in human lung adenocarcinoma cell line A549. However, the underlying mechanisms are not fully understood. We found that BoHV-1 infection decreased the steady-state protein levels of p53-binding protein 1 (53BP1), which plays a central role in dictating DNA damage repair and maintaining genomic stability. Furthermore, BoHV-1 impaired the formation of 53BP1 foci, suggesting that BoHV-1 inhibits 53BP1-mediated DNA damage repair. Interestingly, BoHV-1 infection redistributed intracellular β-catenin, and iCRT14 (5-[[2,5-Dimethyl-1-(3-pyridinyl)-1H-pyrrol-3-yl]methylene]-3-phenyl-2,4-thiazolidinedione), a β-catenin-specific inhibitor, enhanced certain viral protein expression, such as the envelope glycoproteins gC and gD, and enhanced virus infection-induced DNA damage. Therefore, for the first time, we provide evidence showing that BoHV-1 infection disrupts 53BP1-mediated DNA damage repair and suggest β-catenin as a potential host factor restricting both virus replication and DNA damage in A549 cells.     

Evaluation of the Gamma-H2AX Assay for Radiation Biodosimetry in a Swine Model

There is a paucity of large animal models to study both the extent and the health risk of ionizing radiation exposure in humans. One promising candidate for such a model is the minipig. Here, we evaluate the minipig for its potential in γ-H2AX-based biodosimetry after exposure to ionizing radiation using both Cs137 and Co60 sources. γ-H2AX foci were enumerated in blood lymphocytes and normal fibroblasts of human and porcine origin after ex vivo γ-ray irradiation. DNA double-strand break repair kinetics in minipig blood lymphocytes and fibroblasts, based on the γ-H2AX assay, were similar to those observed in their human counterparts. To substantiate the similarity observed between the human and minipig we show that minipig fibroblast radiosensitivity was similar to that observed with human fibroblasts. Finally, a strong γ-H2AX induction was observed in blood lymphocytes following minipig total body irradiation. Significant responses were detected 3 days after 1.8 Gy and 1 week after 3.8 and 5 Gy with residual γ-H2AX foci proportional to the initial radiation doses. These findings show that the Gottingen minipig provides a useful in vivo model for validation of γ-H2AX biodosimetry for dose assessment in humans.     

Unveiling the Toxicity of Fine and Nano-Sized Airborne Particles Generated from Industrial Thermal Spraying Processes in Human Alveolar Epithelial Cells

High-energy industrial processes have been associated with particle release into workplace air that can adversely affect workers’ health. The present study assessed the toxicity of incidental fine (PGFP) and nanoparticles (PGNP) emitted from atmospheric plasma (APS) and high-velocity oxy-fuel (HVOF) thermal spraying. Lactate dehydrogenase (LDH) release, 2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate (WST-1) metabolisation, intracellular reactive oxygen species (ROS) levels, cell cycle changes, histone H2AX phosphorylation (γ-H2AX) and DNA damage were evaluated in human alveolar epithelial cells at 24 h after exposure. Overall, HVOF particles were the most cytotoxic to human alveolar cells, with cell viability half-maximal inhibitory concentration (IC₅₀) values of 20.18 µg/cm² and 1.79 µg/cm² for PGFP and PGNP, respectively. Only the highest tested concentration of APS-PGFP caused a slight decrease in cell viability. Particle uptake, cell cycle arrest at S + G₂/M and γ-H2AX augmentation were observed after exposure to all tested particles. However, higher levels of γ-H2AX were found in cells exposed to APS-derived particles (~16%), while cells exposed to HVOF particles exhibited increased levels of oxidative damage (~17% tail intensity) and ROS (~184%). Accordingly, APS and HVOF particles seem to exert their genotoxic effects by different mechanisms, highlighting that the health risks of these process-generated particles at industrial settings should not be underestimated.     

125I籽源持续低剂量率照射诱导人肺癌细胞的旁效应

观察125I籽源持续低剂量率照射诱导人肺癌细胞损伤的旁效应.选择对高剂量率外照射敏感性不同的A549人肺腺癌细胞和NCI-H446人小细胞肺癌细胞,采用125I籽源离体照射细胞模式,将直接受照细胞与未受照细胞共培养24h,应用CB微核法和γH2AX荧光免疫分析法,检测2Gy和4Gy125I籽源持续低剂量率照射诱导人肺癌细胞的微核形成和DNA双链断裂水平.结果表明,125I籽源照射能显著诱导A549和NCI-H446细胞的微核形成率和γH2AX位点形成率增加的旁效应,显示增强对肿瘤细胞的杀伤作用.旁效应强弱与累积照射剂量、肿瘤细胞的辐射敏感性相关:对高剂量率外照射敏感的NCI-H446细胞对低剂量率照射及其旁效应的敏感性高于A549细胞,但与直接辐射效应相比,125I籽源照射诱导A549细胞旁效应高于NCI-H446细胞,这两种细胞的辐射旁效应均随累积照射剂量增加而降低,提示介导旁效应的信号因子水平可能随细胞损伤程度的增加而下降.