Packed-Fiber Solid Phase-Extraction Coupled with HPLC-MS/MS for Rapid Determination of Lipid Oxidative Damage Biomarker 8-Iso-Prostaglandin F2α in Urine

The 8-iso-prostaglandin F_2α (8-iso-PGF_2α) biomarker is used as the gold standard for tracing lipid oxidative stress in vivo. The analysis of urinary 8-iso-PGF_2α is challenging when dealing with trace amounts of 8-iso-PGF_2α and the complexity of urine matrixes. A packed-fiber solid-phase extraction (PFSPE)–coupled with HPLC-MS/MS–method, based on polystyrene (PS)-electrospun nanofibers, was developed for the specific determination of 8-iso-PGF_2α in urine and compared with other newly developed LC-MS/MS methods. The method, which simultaneously processed 12 samples within 5 min on a self-made semi-automatic array solid-phase extraction processor, was the first to introduce PS-electrospun nanofibers as an adsorbent for the extraction of 8-iso-PGF_2α and was successfully applied to real urine samples. After optimizing the PFSPE conditions, good linearity in the range of 0.05–5 ng/mL with R² > 0.9996 and a satisfactory limit of detection of 0.015 ng/mL were obtained, with good intraday and interday precision (RSD < 10%) and recoveries of 95.3–103.8%. This feasible method is expected to be used for the batch quantitative analysis of urinary 8-iso-PGF_2α.     

Preparation of Silica Aerogel/Resin Composites and Their Application in Dental Restorative Materials

As the most advanced aerogel material, silica aerogel has had transformative industrial impacts. However, the use of silica aerogel is currently limited to the field of thermal insulation materials, so it is urgent to expand its application into other fields. In this work, silica aerogel/resin composites were successfully prepared by combining silica aerogel with a resin matrix for dental restoration. The applications of this material in the field of dental restoration, as well as its performance, are discussed in depth. It was demonstrated that, when the ratio of the resin matrix Bis-GMA to TEGDMA was 1:1, and the content of silica aerogel with 50 μm particle size was 12.5%, the composite achieved excellent mechanical properties. The flexural strength of the silica aerogel/resin composite reached 62.9546 MPa, which was more than five times that of the pure resin. Due to the presence of the silica aerogel, the composite also demonstrated outstanding antibacterial capabilities, meeting the demand for antimicrobial properties in dental materials. This work successfully investigated the prospect of using commercially available silica aerogels in dental restorative materials; we provide an easy method for using silica aerogels as dental restorative materials, as well as a reference for their application in the field of biomedical materials.     

ErLaP_5O_（14）非晶上转换发光分析

测量了Ｅｒ０．１Ｌａ０．９Ｏ１４非晶在６４９．０ｎｍ脉冲染料激光泵浦下的上转换荧光谱线（５５２．２，５４５．７，５４２．９）ｎｍ，５２５．０ｎｍ．４６８．８ｎｍ，４５２．２ｎｍ．（４１１．２，４０７．０）ｎｍ，３８４．１ｎｍ．３８０．７ｎｍ，其中（５５２．２，５４５．７，５４２．９）ｎｍ，（４１１．２．４０７．０）ｎｍ．３８４．１ｎｍ话线是共振步进双光子吸收导致的，而４６８．８ｎｍ．４５２．２ｎｍ，３８０．７ｎｍ是三光子荧光。     

Switched-current delta-sigma A/D converters

Switched-current oversampling A/D converters are the ideal choice for mixed analog/digital design due to their complete compatibility with digital CMOS process and high tolerance to process variation. This paper presents a tutorial discussion on all the aspects of switched-current oversampling A/D converters, including structures, circuits, and practical issues. Three different modulator structures and six different types of switched-current circuits were used with an emphasis on low-voltage operation. Eight 3.3-V oversampling A/D converters were implemented and measured, and another one 1.2-V oversampling A/D converter was also implemented but yet to be measured.     

海上平台智能安防监控系统设计及研究

以埕海海域某平台为例,将智能视频监控系统、船舶自动识别系统（Automatic Identification System, AIS）、广播报警系统以及计算机监控等技术相结合,设计和研发了一套适用于海上无人驻守平台的安防监控系统。该系统实现了对平台周边海域状况和登陆平台处的昼夜实时在线监测,可以智能识别靠近平台的非法船舶和登陆平台的外来人员,并自动触发声光报警进行驱离。运行结果表明,这种系统可以对异常事件作出准确及时的响应,并能自动触发关联设备,从而提升了海上平台安防监控的智能化水平。该研究对于优化海上平台安防监控技术具有一定的实际意义。     

Pogostone Enhances the Antibacterial Activity of Colistin against MCR-1-Positive Bacteria by Inhibiting the Biological Function of MCR-1

The emergence of the plasmid-mediated colistin resistance gene mcr-1 has resulted in the loss of available treatments for certain severe infections. Here we identified a potential inhibitor of MCR-1 for the treatment of infections caused by MCR-1-positive drug-resistant bacteria, especially MCR-1-positive carbapenem-resistant Enterobacteriaceae (CRE). A checkerboard minimum inhibitory concentration (MIC) test, a killing curve test, a growth curve test, bacterial live/dead assays, scanning electron microscope (SEM) analysis, cytotoxicity tests, molecular dynamics simulation analysis, and animal studies were used to confirm the in vivo/in vitro synergistic effects of pogostone and colistin. The results showed that pogostone could restore the bactericidal activity of colistin against all tested MCR-1-positive bacterial strains or MCR-1 mutant–positive bacterial strains (FIC < 0.5). Pogostone does not inhibit the expression of MCR-1. Rather, it inhibits the binding of MCR-1 to substrates by binding to amino acids in the active region of MCR-1, thus inhibiting the biological activity of MCR-1 and its mutants (such as MCR-3). An in vivo mouse systemic infection model, pogostone in combination with colistin resulted in 80.0% (the survival rates after monotherapy with colistin or pogostone alone were 33.3% and 40.0%) survival at 72 h after infection of MCR-1-positve Escherichia coli (E. coli) ZJ487 (blaNDM-1-carrying), and pogostone in combination with colistin led to one or more order of magnitude decreases in the bacterial burdens in the liver, spleen and kidney compared with pogostone or colistin alone. Our results confirm that pogostone is a potential inhibitor of MCR-1 for use in combination with polymyxin for the treatment of severe infections caused by MCR-1-positive Enterobacteriaceae.     

神光装置φ200mm口径KDP晶体高功率倍频激光系统

报道了φ２００ｍｍ口径ＫＤＰ晶体高功率倍频激光系统的研制结果，并实现了神光装置信频激光打靶。五十枪次全口径打靶实验表明，倍频激光系统性能稳定。实验中，当入射基频激光强度大于１．５ＧＷ／ｃｍ２，倍频器的外部转换效率保持在６０％以上。最大入射基频激光能量为３５７．８Ｊ时，输出倍频激光能量为２２３．４Ｊ，倍频转换效率为６５．６％。     

CDMA移动通信中多址用户干扰抵消技术

本文简要讨论了码分多址移动通信中多址用户干扰的产生和抵消机理,并分别介绍了前向链路和反向链路的多址用户干扰抵消技术。     

原子系统中偶极-偶极相互作用对量子存储支撑熵不确定度的调控研究

本文研究了Markovian过程和non-Markovian过程两种情况下,原子系统中偶极-偶极(D-D)相互作用和失谐量对两原子系统量子存储支撑(QMA)熵不确定度的调控作用.与Markovian过程相比,在non-Markovian过程中,由于库环境的记忆效应使得具有D-D相互作用的两原子系统QMA熵不确定度的演化行为呈现出振荡上升现象,且熵不确定度的上升趋势得到减缓,从而抑制了由系统量子噪声引起的退相干效应.此外,D-D相互作用对两原子系统QMA熵不确定度具有显著的调控能力,且D-D相互作用比失谐量的调控能力更强.     

一种电流引线的热力学计算方法

从超导磁体气冷电流引线的热平衡方程出发,对电流引线进行分段,提出了一种较为精确计算电流引线长横比及由电流引线末端流入低温容器热量的计算方法;电流引线中氦气流阻是设计电流引线时一个很重要的参数,由于电流引线片形状很复杂,计算其中氦气流阻比较好的方法是采用CFD软件Fluent。氦气模型单元数很庞大,因此对氦气模型进行了简化和分段,相邻两段模型间采用流量和压力边界条件进行耦合。