Continuous Spectroscopy Characterization of Emulsions

In emulsion polymerization, the formation of particles has an important effect on the rate of reaction and on the final properties of the latex. To investigate particle nucleation mechanisms in emulsion polymerization it is necessary to establish the initial conditions of the emulsified system before the reaction takes place. This research reports on a technique to continuously monitor the droplet size distribution of liquid-liquid emulsions using spectroscopy. The on-line particle characterization methodology is based on an integrated sampling and dilution strategy combined with spectroscopy methods. It is shown that the sampling system integrated with a multiwavelength turbidity detector provides reliable estimates of droplet populations as function of the dispersed phase concentration in emulsions of saturated hydrocarbons. The results provide not only the groundwork necessary for the elucidation of particle nucleation during emulsion polymerization process but also suggests the potential of this combined technology to further our understanding of liquid-liquid emulsions.     

基于CAN总线的某型数字化战车自动测试系统设计

针对现代数字化战车电气与电子系统技术复杂、各分系统关联程度高、维修保障困难等问题,设计了一种基于CAN总线的数字化战车自动测试系统;整体设计基于模块化思想,充分利用车载备用总线,综合运用了DSP+FPGA控制处理技术、AFPN智能故障诊断技术,能够对车载电气与电子系统进行分系统独立测试和全系统联合检测,具有快速故障定位能力和拓扑适应能力;采用适配器与上位机测试软件的分体式设计,实现了平台物理资源复用。应用表明,该系统能够较好的适用于现代数字化战车的维修保障,使用方便,故障诊断快速有效。     

基于电喷雾电离质谱的人肝癌细胞HepG2与正常肝细胞L02的N-糖链的定性定量比较

以培养的原发性肝癌细胞HepG2和正常肝细胞L02为研究对象,采用细胞裂解液提取总蛋白,用PNGase F酶解释放N-糖链,以微晶纤维素柱结合石墨碳柱纯化分离N-糖链,通过电喷雾电离质谱(ESI-MS)和串联质谱(MS/MS)对N-糖链进行序列鉴定,以β-环糊精为内标对2种细胞系的N-糖链进行了定量比较分析.结果表明,在肝癌细胞系HepG2和正常细胞系L02中共检测到26种N-糖链,与L02相比,HepG2的大多数高甘露糖型糖链、唾液酸化糖链和岩藻糖基化糖链的数量都明显升高,其中有15种糖链在数量上具有极显著性差异(p0.01),1种糖链具有显著性差异(p0.05).本研究为进一步探索肝癌中各类N-糖链的表达特点及发现早期肝癌糖链标志物提供了参考.     

Determination of cysteine,homocysteine, cystine,and homocystine in biological fluids by HPLC using fluorosurfactant‐capped gold nanoparticles as postcolumn colorimetric reagents

We have demonstrated for the first time the suitability of fluorosurfactant‐capped spherical gold nanoparticles as HPLC postcolumn colorimetric reagents for the direct assay of cysteine, homocysteine, cystine, and homocystine. The success of this work was based on the use of an on‐line tris(2‐carboxyethyl)phosphine reduction column for cystine and homocystine. Several parameters affecting the separation efficiency and the postcolumn colorimetric detection were thoroughly investigated. Under the optimized conditions, cysteine, homocysteine, cystine, and homocystine in human urine and plasma samples were determined. Detection limits for cysteine, homocysteine, cystine, and homocystine ranged from 0.16–0.49 μM. The accuracy in terms of recoveries ranged between 94.0–102.1%. This proposed method was rapid, inexpensive, and simple.     

Aspects of trapping efficiency and matrix effects in the development of a restricted‐access‐media‐based trap‐and‐elute liquid chromatography with mass spectrometry method

Online restricted access media with liquid chromatography and tandem mass spectrometry for the direct analysis of small molecules in biological fluids represents an interesting alternative to time‐demanding traditional sample preparation techniques. In this study, important considerations concerning the development of a restricted access media with liquid chromatography and tandem mass spectrometry method for the analysis of dansylated estrogens in biological matrix are presented. Parameters influencing peak tailing and trapping efficiency were evaluated. The key factors included the ion strength of the mobile phase, a loading flow rate of the sample onto the trap column, and selection of a proper stationary phase of the trap column for a given set of analytes. These parameters have proven to be essential for minimizing any unwanted chromatographic peak tailing. The bulk derivatization of the analytes in the biological fluids and its relationship to the observed matrix effects was evaluated as well.     

Histone deacetylase (HDAC) inhibitor curcumin upregulates mitochondrial uncoupling protein1 (UCP1) and mitochondrial function in brown adipocytes,in-silico study and screening natural drug library

Mitochondrial dysfunction has been associated with diverse pathological conditions globally. Specifically, in adipose tissues, mitochondrial dysfunction is the primary cause of obesity and obesity-related illnesses. An existing drugs such as atorvastatin and other lipid-lowering drugs demonstrated adverse effects and initiated other diseases. Thus, we need to explore new methods to prevent and treat obesity. In this study, we used the cell screening method to identify several natural compounds that increase adipocyte UCP1 gene expression. The identified drug Curcumin was evaluated in cell models and the In-silico model. We found curcumin is an active compound of turmeric belonging to Zingiberaceae (ginger family), which activates the Nrf2 mechanism. Curcumin potentially endorses the expression of UCP1 in the brown adipocyte in vitro cellular model. Curcumin plays an important role that modulating mitochondrial function and improving mitochondrial DNA quantification, ATP production, and cell viability. We have established an efficient in vitro cell experiment system to study the metabolic regulation of UCP1. The in-silico model revealed curcumin-UCP1 interaction. Curcumin, via enhancing mitochondrial activity, could be a helpful therapeutic molecule against metabolic disorders or obesity-related diseases. Curcumin will be the subject of more research in both human and murine models, which will provide novel therapeutic pathways for the treatment of metabolic illnesses by modulating the control of mitochondrial function.     

Polarity guided extraction,HPLC based phytochemical quantification,and multimode biological evaluation of Otostegia limbata (Benth.) Boiss

Purpose of studyOtostegia limbata (Benth.) Boiss. (Family: Lamiacae) is an important underexplored ethnomedicinal plant that has been used as antinflammatory, anticancer and antibacterial herbal remedy previously. The present work was aimed to evaluate the antioxidant, antimicrobial, antileishmanial, and anticancer prospective of O. limbata stem and leaf extracts.ResultsThe highest amount of phenolic and flavonoid content was obtained in the methanol-acetone and methanol stem extracts i.e., 53.29 ± 1.33 and 28.64 ± 1.16, respectively with highest DPPH scavenging in MeH stem extract (IC₅₀ = 34.5 ± 1.34 μg/ml). Significant amount of catechin, gallic acid, apigenin and rutin was quantified. A moderate antibacterial and substantial antifungal activity was observed. Cytotoxicity against brine shrimps categorized 21% of stem (3 out of 14 extracts) and 57% (8 out of 14 extracts) of leaf extracts as potent. Substantial cytotoxicity against THP-1 cell line (IC₅₀ = 3.46 ± 0.25 μg/ml) and Leishmania (IC₅₀ = 1.50 ± 0.23 μg/ml) was exhibited by methanol-distilled water leaf extract while noteworthy antiproliferative activity against Hep-G2 (IC₅₀ = 0.44 ± 0.45 μg/ml) was manifested by n-hexane stem extract. Absence of hemolysis in normal RBCs signified plant’s selective cytotoxicity. Methanol-distilled water and chloroform stem extracts displayed prominent protein kinase inhibition and antidiabetic potential of plant.ConclusionThe results of present study recommend O. limbata as a potential source of antifungal, antileishmanial, anticancer, and α-amylase inhibitory agents.     

基于3G-ASCX的小型飞行器异常导航信号检测系统设计

传统方法在异常导航信号信噪比较低时对小型飞行器异常导航信号的检测效果不理想。设计并实现了一种基于3G-ASCX的小型飞行器异常导航信号检测系统,硬件设计时着重于ASCX传感器模块、异常导航信号检测模块、主控基站模块、3G/GPRS传输模块的研究,3G/GPRS传输模块的硬件设计中,通过功耗低体积小的CC1100完成异常导航信号的收发,传输过程中通过芯片STC12C5410AD完成电容的平衡转换,选取了MC3486进行电压的转换,最终实现异常信号数据的安全快速传输;软件设计中,系统软件流程设计及异常导航信号检测模块软件设计,最后进行仿真实验,实验结果证明,相比传统系统,所设计系统检测到的小型飞行器异常导航信号同实际测量的异常导航信号具有较高的匹配度,与实际值相比,误差小于1dB,适合推广使用。     

基于CAN总线的遥测数据处理模块软件设计

随着飞行器电子综合化技术的发展,数据总线在飞行器中得到大量应用。为满足某飞行器总线系统测量的需求,本文设计了一种基于CAN总线的遥测数据处理模块。硬件部分主要由CAN总线驱动器模块、DSP数字信号处理模块、FPGA逻辑处理模块组成。软件设计包括TMS320F28335的初始化,CAN总线数据处理和外部中断处理三部分。该模块用于某飞行器双路CAN总线数据的采集及处理,并经过了多次飞行试验验证。该模块简化了系统设计,实现了高速、可靠的CAN总线遥测数据处理。     

基于CAN总线的运动控制通讯系统设计

数字量驱动的运动控制要求通讯系统具有良好的实时性和可靠性。设计了一种基于CAN总线的多节点多通道的运动控制通讯系统,以FPGA为节点控制器,通过SJA1000收发运动控制数据,并行发送到各通道驱动器的数模转换器中。FPGA模块由Verilog HDL编写,通过参数传递和生成块的方法简化代码,提高系统的可移植性,移植时只需改变两个常量值即可适应各个节点不同的通道数和位宽。实验表明,通讯系统每帧耗时约120us,最高帧频可达8.5kHz,误码率低于10^-8,实时性和可靠性较好。