Performance of a sound card as data acquisition system and a lock-in emulated by software in capillary electrophoresis

The performance of fluorescence detectors in capillary electrophoresis is maximized when the excitation light intensity is modulated in time with optimal frequencies. This is especially true when photomultiplier tubes are used to detect the fluorescent light. The photomultiplier tube amplified raw output signal can in principle be captured directly by a personal computer sound card (PCSC) and processed by a lock-in emulated by software. This possibility is demonstrated in the present work and the performance of this new setup is compared with a traditional data acquisition system. The results obtained with this “PCSC and lock-in emulated by software” were of the same quality or even better compared to that obtained by conventional time integrators (Boxcars) and data acquisition boards. With PCSC the limits of detection (LOD) found for both naphthalene-2,3-dicarboxaldehyde-derivatized tyrosine and alanine were 3.3 and 3.5 fmol (injection of 5 nL of samples at 0.66 and 0.70 μmol/L), respectively. This is at least three times better compared to conventional systems when light emitting diodes (LEDs) are used as the excitation source in fluorescence detectors. The PCSC linear response range was also larger compared to conventional data acquisition boards. This scheme showed to be a practical and convenient alternative of data acquisition and signal processing for detection systems used in capillary electrophoresis.     

智能手机中的SIM卡密码管理

随着移动多媒体时代的到来,拥有强大娱乐商务功能的智能手机越来越受到消费者的青睐。文中简要介绍一种新的智能手机平台Qtopia、Qtopia中独特的信号与槽机制、SIM(用户识别模块)卡中密码的种类以及Qtopia如何采用AT指令来管理SIM卡密码,并阐述了实际智能手机项目中SIM卡密码管理程序的实现思路。     

基于校园网络的一卡通系统设计

从建设数字化校园。实现校园一卡通的要求出发，探讨了校园一卡通系统的总体设计方案，并对校园宽带环境下的一卡通系统的具体结构和功能进行了详细的阐述。提出了将一卡通系统建设成为信息资源数字化，通信传输网络化，用户终端智能化。管理结算自动化的数字化系统的可行方法。     

一种基于光电识别的插卡式电子开关的设计

介绍了利用光电识别原理来制作的“基于光电识别的插卡式电子开关”，是在原有宾馆客房IC卡的任一面，设定好规定的位置上，印制上反射光线的白点和吸收光线的黑点的图案，IC卡插入开关的相应位置有两只反射和接受红外线的器件，读取相应的高低电平，经过逻辑电路的处理，和原来开关一样驱动继电器而输出电压。改制后的插卡取电开关具有只能用宾馆提供的钥匙IC卡来开门并务必用它开通客房的用电开关，才能正常点灯或使用电器；改变了原来进门后用名片或其它物品来打开用电开关，出门时又不关电源带着钥匙卡就走的现状；既节省了电能又消除了安全隐患，用于宾馆的客房，真正做到一卡通。有一定的使用、推广价值和发展前景。     

针对EMVLevel1 Analog Test认证的金融支付PCD设计与调试

文章针对最新版EMV Level 1标准,对PCD的EMV Level 1 Analog test认证的检测环境及检测项目进行总结,对实际测试中可能遇到的问题进行分析,总结出其技术难点。针对这些难点提出PCD设计中需要重点关注的方面以及设计技巧,进一步给出调试中使用怎样的方法达到系统的最优配置,成功通过EMV Level1 Analog test的检测。     

裸眼3D系统SD卡FPGA读取显示研究

SD卡可为便携式裸眼3D设备提供数据来源,图像存储于SD卡中,FPGA以SPI协议方式读出,再经过FIFO和SDRAM进行数据缓存,通过接口输入显示器显示.探讨了通过FPGA器件读取SD卡图像进行显示的实现方法,得出了SD卡文件读取及显示的可行逻辑设计.系统性能经过初步验证,可行性良好.     

基于组播信号的数字电视字幕插播方案

随着数字电视整体转换的推进,电视节目的数字化播出信号源发生了变化,特别是数字前端平台IP组播的应用,字幕插播系统需要重新规划设计。介绍了基于组播信号的数字电视字幕插播系统的内涵、系统结构和工作流程,详细描述各个部分的设备功能和调试配置,整体构成基于组播信号的数字电视字幕插播系统方案。     

基于SIM卡的金融应用移动数字签名业务研究

随着智能终端和移动互联网的快速发展,在网上银行等行业应用中使用移动终端进行用户认证的方式愈发普及.传统的USB key用户认证方式逐渐被基于移动终端的用户认证方式取代.从移动运营商角度出发,研究分析了利用移动终端和SIM卡实现金融类应用用户数字签名认证的技术要求,梳理了基于智能终端和智能卡的安全技术,提出了基于电信智能卡的金融类应用用户签名和身份认证的技术架构和业务流程.     

Antioxidative and Anti-Inflammatory Phytochemicals and Related Stable Paramagnetic Species in Different Parts of Dragon Fruit

In this study, we investigated the antioxidant and anti-inflammatory phytochemicals and paramagnetic species in dragon fruit using high-performance liquid chromatography (HPLC) and electron paramagnetic resonance (EPR). HPLC analysis demonstrated that dragon fruit is enriched with bioactive phytochemicals, with significant variations between each part of the fruit. Anthocyanins namely, cyanidin 3-glucoside, delphinidin 3-glucoside, and pelargonidin 3-glucoside were detected in the dragon fruit peel and fresh red pulp. Epicatechin gallate, epigallocatechin, caffeine, and gallic acid were found in the dragon fruit seed. Additionally, 25–100 mg × L⁻¹ of dragon fruit pulp and peel extracts containing enrichment of cyanidin 3-glucoside were found to inhibit the production of reactive oxygen species (ROS), reactive nitrogen species (RNS), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) in cell-based studies without exerted cytotoxicity. EPR primarily detected two paramagnetic species in the red samples. These two different radical species were assigned as stable radicals and Mn²⁺ (paramagnetic species) based on the g-values and hyperfine components. In addition, the broad EPR line width of the white peel can be correlated to a unique moiety in dragon fruit. Our EPR and HPLC results provide new insight regarding the phytochemicals and related stable intermediates found in various parts of dragon fruit. Thus, we suggest here that there is the potential to use dragon fruit peel, which contains anthocyanins, as a natural active pharmaceutical ingredient.     

Water-in-Oil-in-Water Nanoemulsions Containing Temulawak (Curcuma xanthorriza Roxb) and Red Dragon Fruit (Hylocereus polyrhizus) Extracts

Hydrophobic curcumin in temulawak extract and hydrophilic betacyanin in red dragon fruit extract are high-value bioactive compounds with extensive applications in functional food. In this study, these extracts were encapsulated in water-in-oil-in-water (w/o/w) nanoemulsions as a delivery system using a two-step high-energy emulsification method. PGPR and Span 20 were used as lipophilic emulsifiers for the primary w/o emulsion. The most stable w/o/w formulation with the least oil phase separation of 5% v/v consisted of w/o emulsion (15% w/w) and Tween 80 (1.5% w/w) as hydrophilic emulsifier. The formulation was characterized by a 189-nm mean droplet diameter, 0.16 polydispersity index, and –32 mV zeta potential. The freeze–thaw stability may be attributed to the combination of low w/o emulsion content and high Tween 80 concentration in the outer water phase of the w/o/w nanoemulsions used in this study. The IC₅₀ values of the nanoemulsion and the red dragon fruit extract were similar. It means that the higher concentration of curcumin in the nanoemulsions and the lower IC₅₀ value of temulawak extract ensured sufficient antioxidant activities of the w/o/w nanoemulsions.