The effect of the EAAEAE insert on the property of human metallothionein-3

MT3 shows apparently different properties and function fromMT1 even though they have 70% sequence homology. Possibly thetwo inserts, Thr5 and a negatively charged hexapeptide at position-55in MT3, play important roles. A series of MT3 variants aroundthe EAAEAE hexapeptide have been prepared by site-directed mutagenesisand their properties and reactivity towards pH, EDTA and DTNBhave been studied. Our detailed studies revealed that the EAAEAEinsert is essential to the property of MT3. It is the hexapeptideinsert, to some extent, making the MT3     

On/off cycling under multiple stresses

The authors describe an experiment, a model, and an analytic method for on/off vs. continuous policy evaluation. The methodology was developed and verified through experimentation. An experimental life-test of small DC motors was designed and performed; it involved on/off cycling vs. continuous operation under multiple stresses. A stress-factor reliability model based on the two-parameter Weibull proportional-hazards life distribution was fitted to the data. The analysis provides an estimate of the model parameters for the life distribution of the DC motors under two operating policies, while under multiple stresses. The characteristic life was related to the explanatory covariates: voltage, on/off cycling, and load. Due to the proportional hazards (common Weibull shape) nature of the model, acceleration factors were calculated to relate the stress levels. The reliability model was extended to develop a simple rule to aid in a decision between on/off cycling and continuous-run policies (to achieve higher reliability). The proposed model (with covariates) allows a much broader approach to reliability modeling than the usual Weibull model (without covariates) because it predicts the reliability under various environmental combinations     

基于MVC和EF的学位与研究生教育信息管理系统设计与实现

为促进学校学位与研究生教育信息管理水平,在MVC设计模式基础上结合EF(ADO.NET Entity Framework)框架和Ajax技术,探讨学位与研究生教育信息管理系统的设计与实现。系统包括用户管理、学籍管理、课程管理、成绩管理、奖学金管理、导师管理、双盲评审管理和学位信息管理8个模块,具有较好的可用性、稳定性和可扩展性。     

针对不同平台获取MAC地址的特定方法

文章提出了在不同操作系统以及不同平台上获取MAC地址的方法。以目前比较典型的两种操作系统:UNIX操作系统和WINDOWS操作系统为例,阐述了具体方法,并给出了相应的C/C++语言读取MAC地址的实现程序。     

基于B/S结构的大学生物品交换系统的设计与实现

大学生物品交换系统的宗旨在于不求回报无偿付出,在充分利用各种资源的同时,培养学生的勤俭节约意识和"低碳"意识,加强学生之间的联系与互动,促进节约型校园的发展,并且符合近年来一直倡导的"和谐校园"与"低碳校园"的要求。系统基于B/S结构,采用ASP作为系统开发语言,使用SQL SERVER 2000数据库作为整个交易系统的数据库服务器,提供数据存储和调用,实现基于B/S结构的大学生物品交换系统。     

SPI总线扩展PLC输出点数的设计与实现

针对PLC主模块可用输出点数少的缺点,提出了采用SPI总线和移位寄存器HC595相结合扩展PLC输出点数,并设计了输出扩展电路;根据SPI总线及HC595的时序特点,确定了SPI的时钟模式,解决了时序的配合问题,并确定了输出点数的逻辑顺序;UDTY端接一下拉电阻,保证其处于高电平,SPI2CLK信号取反后输入到HC595,保证其采样到稳定的SPI输出数据,滤波电容,提高了电路抗干扰性能;编程实现对扩展输出点数的控制。实际应用表明,该设计方案经济、可靠。     

Local Epidermal Endocrine Estrogen Protects Human Melanocytes against Oxidative Stress,a Novel Insight into Vitiligo Pathology

As the outermost barrier of the body, skin is a major target of oxidative stress. In the brain, estrogen has been reported synthesized locally and protects neurons from oxidative stress. Here, we explored whether estrogen is also locally synthesized in the skin to protect from oxidative stress and whether aberrant local estrogen synthesis is involved in skin disorders. Enzymes and estrogen receptor expression in skin cells were examined first by quantitative real-time PCR and Western blot analyses. Interestingly, the estrogen synthesis enzyme was mainly localized in epidermal keratinocytes and estrogen receptors were mainly expressed in melanocytes among 13 kinds of cultured human skin cells. The most abundant estrogen synthesis enzyme expressed in the epidermis was 17β-hydroxysteroid dehydrogenase 1 (HSD17β1) localized in keratinocytes, and the most dominant estrogen receptor expressed in the epidermis was G protein-coupled estrogen receptor 1 (GPER1) in melanocytes. To investigate whether keratinocyte-derived estradiol could protect melanocytes from oxidative stress, cultured human primary epidermal melanocytes (HEMn-MPs) were treated with H₂O₂ in the presence or absence of 17β estradiol or co-cultured with HSD17β1 siRNA-transfected keratinocytes. Keratinocyte-derived estradiol exhibited protective effects against H₂O₂-induced cell death. Further, reduced expression of HSD17β1 in the epidermis of skin from vitiligo patients was observed compared to the skin from healthy donors or in the normal portions of the skin in vitiligo patients. Our results suggest a possible new target for interventions that may be used in combination with current therapies for patients with vitiligo.     

基于GWO-SVM的下肢假肢穿戴者骑行相位识别

针对下肢假肢穿戴者骑行相位识别的问题,提出基于灰狼算法优化的支持向量机(GWO-SVM)分类模型. 建立下肢多源信息系统,采集膝关节、踝关节的加速度信号以及膝关节角度信号. 应用奇异值分解,对采集到的信号进行降噪处理. 在对信号进行降噪处理之后,为了避免单一信号不确定的影响,从数据冗余角度,选取各信号的特征点,开展归一化处理,组成多维特征向量,作为SVM分类模型的输入. 为了能够进一步提高分类精度,加强全局优化能力,利用GWO算法对核参数进行优化. 通过与PSO-SVM分类模型、GA-SVM分类模型对比表明,基于GWO优化的SVM分类模型对骑行相位的识别率为94%,高于其他方法优化的SVM分类模型.     

钨酸镁催化超声降解金橙Ⅱ研究

采用水热法合成了钨酸镁(MgWO4)半导体催化剂,并使用金橙II为有机污染物模型研究了其声催化降解性能.结果表明:MgWO4具有良好的声催化活性,可显著提升超声对有机污染物的降解效果,而且MgWO4具有优秀的可重复利用性能.同时,MgWO4催化超声降解金橙Ⅱ的机理研究表明,产生的活性物质如羟自由基(·OH)、超氧阴离子自由基(·O2-)和空穴(h+)是声催化降解金橙II的主要原因.以上研究结果表明MgWO4作为声催化剂用于处理有机染料废水具有良好的应用前景.     

熔融织构YBCO块样品的磁特性研究

对MTG区熔生长法,慢冷法,粉末熔融生长法这3种方法制备的熔融织构YBCO块样品进行了交流磁化率和磁阻的测量。根据实验结果计算了样品的钉扎势,并且发现3种方法制备的样品在150 mT外磁场下均显示出基本消除弱连接的特性;粉末融熔生长法所制样品中有较纯净123相和较好织构,质量最好。