Antioxidant enzymes from the crab Scylla paramamosain: Gene cloning and gene/protein expression profiles against LPS challenge

Recent studies revealed that antioxidant enzymes play important roles in antioxidant responses caused by metabolic process or pathogen invasion. Catalase is one of these key enzymes which has been characterized and highly conserved from invertebrates to vertebrates. In the present study, a full-length cDNA sequence of catalase was cloned from the hemocyte suppression subtractive hybridization library of the crab Scylla paramamosain. The Sp-catalase (Sp-CAT) cDNA sequence contained 2551 bp with an open reading frame of 1551 bp encoding 517 amino acid residues. The conserved catalytic active residues His-71, Asn-144 and Tyr-354 were predicted in the amino acid sequence of Sp-CAT. The deduced Sp-CAT protein had a calculated molecular mass of 59 kDa with an estimated isoelectric point of 6.4. Multiple alignment analysis revealed that the deduced amino acid sequence of Sp-CAT shared high identity (75.4%) with those of other species. The Sp-CAT mRNA transcripts were demonstrated in multiple tissues of normal S. paramamosain. After LPS challenge, the expression level of Sp-CAT gene was increased significantly in hemocyte at 3 and 6 h, and in hepatopancreas at 6 h, respectively, determined by quantitative real-time PCR. Furthermore, the activities of CAT and SOD were also measured in different tissues and serum after LPS challenge. The CAT activity was significantly increased at 3, 6, 24 and 48 h in hemocyte lysate, at 3 h in serum, and at 24 and 48 h in hepatopancreas after LPS challenge. In addition, the SOD activity was significantly induced at 3 and 6 h in hemocyte lysate, 3 and 12 h in serum, 12 and 48 h in hepatopancreas post LPS stimulation, indicating a tissue and time-dependent antioxidant response in the crab. Taken together, these data demonstrated that a strong antioxidant response occurred in the LPS-challenged crab, which might be involved in the protection of host against microbial infections. (C) 2010 Elsevier Ltd. All rights reserved.National Natural Science Foundation of China (NSFC) [40676083]; National High Technology Research and Development Program of China [2007AA091406]; Minjiang Scholars Program [2009]; Natural Science Foundation of Fujian Province China (NSFC-FPC) [2009J05084

Calibration and Preliminary Application of Linear Quantitation Standard for Anti-HEV IgG Antibody

目的建立抗戊型肝炎病毒(Anti-HEV)IgG抗体的定量线性标准品,并进行初步应用。方法利用抗-HEV IgG和抗-HEV IgM ELISA检测试剂筛选出1份抗-HEV IgG阳性血清L9,经基因1型和4型的HEV ORF2C-端抗原及239抗原进行Western blot确认后,用WHO定量标准品,由3个实验室协作标定,利用量反应平行线法计算其抗-HEV IgG的含量。考察已标定的L9血清的稳定性,并用所标定的1.5倍系列稀释的血清对国内外6家抗-HEV IgG试剂的灵敏度进行检测。选择一灵敏度较高的试剂,在其线性范围内取L9的5个稀释度作为抗-HEV IgG抗体定量线性标准,对高、中、低浓度的3份临床血清重复检测5次,考察其重复性;对实验感染猴的系列血清中抗-HEV IgG含量进行定量检测,考核该定量线性标准品的应用效果;并对每次定量试验中的线性方程进行分析,确定相关系数r值和斜率k值的范围。结果经国内外试剂检测筛选出的阳性血清L9与基因1型和4型的HEV ORF2 C-端抗原及239抗原均有阳性反应。经协作标定,L9血清抗-HEV IgG含量为16.9U/ml。L9血清在-20℃下保存6、12、18个月,2～8℃保存24、48、96h后,定量结果均在95%置信区间内,且抗-HEV IgG含量均未明显下降。6家抗-HEVIgG检测试剂灵敏度差异较大,范围为0.03～5.00U/ml。确定L9血清从0.42U/ml开始的5个1.5倍系列稀释度,作为某一试剂抗-HEVIgG抗体定量线性标准品。利用该线性定量标准检测高、中、低浓度的3份临床血清,定量结果重复性较好;对实验感染猴系列血清进行定量检测,结果可有效地反映抗体水平变化趋势;94%的定量检测试验,r≥0.98,1.15≥k≥0.95。结论已建立了抗-HEVIgG抗体定量线性标准品,可用于疫苗免疫原性评价和流行病学调查。Objective To develop a linear quantitation standard for anti-hepatitis E virus (HEV) IgG antibody. Methods An anti-HEV IgG positive serum sample L9 was screened by using Anti-HEV IgM ELISA kit and Anti-HEV IgG ELISA kit and confirmed by Western blotting with HEV ORF2 C-terminal antigen of genotypes 1 and 4 and 239 antigen, then calibrated by 3 laboratories using WHO quantitation standard. Calculate the anti-HEV IgG content by dose-response parallel line assay, and evaluate the stability of calibrated serum sample. The sensitivities of 6 domestic and imported anti-HEV IgG ELISA kits were evaluated with the calibrated serum sample diluted 1. 5-fold serially. A linear quantitation standard for anti-HEV IgG antibody consisted of 5 dilutions of L9 within the linear determination range of a highly sensitive kit and evaluated for reproducibility by repeat test for 3 clinical serum samples, at high, moderate and low anti-HEV IgG contents respectively, for 5 times. The anti-HEV IgG contents in serum samples of HEV-infected monkeys were determined by the standard, and the determination curves were analyzed to define correlation coefficient r and slope k. Results Serum sample L9 showed positive reaction with HEV ORF2 C-terminal antigen of genotypes 1 and 4 and 239 antigen, and its anti-HEV IgG content was calibrated as 16. 9 U / ml. After storage at -20℃ for 6, 12 and 18 months or at 2 ～ 8℃ for 24, 48 and 96 h, all the quantitative determination results were within the 95% CI, and anti-HEV IgG content showed no significant decrease. The sensitivities of 6 kits evaluated with the L9 ranged from 0. 03 to 5. 00 U / ml. The linear quantitation standard for anti-HEV IgG antibody consisted of 5 dilutions of L9, starting from a concentration of 0. 42 U / ml. The determination results of 3 clinical serum samples showed good reproducibility of the standard. The determination results of sera of HEV-infected monkeys reflected the change of antibody level effectively. The r values of 94% of quantitative determination curves were not less than 0. 98, and the k values ranged from 1. 15 to 0. 95. Conclusion A linear quantitation standard for anti-HEV IgG antibody was established, which was suitable for the evaluation of immunogenicity and epidemical investigation of vaccine

1978～2008年中国湿地类型变化

分别基于美国陆地卫星(Landsat MSS/TM/ETM+)和中巴资源卫星(CBERS-02B)影像数据,以人工目视解译为主,完成了中国1978～2008年4期(基准年分别为1978,1990,2000和2008年)湿地遥感制图,并进行了大量的室内外验证.在此基础上,对我国湿地现状及近30年来湿地变化进行了初步分析,得到以下主要结论:(ⅰ)截止2008年,中国湿地面积约为324097km2,其中以内陆沼泽(35%)和湖泊湿地(26%)为主.(ⅱ)1978～2008年,中国湿地面积减少了约33%,而人工湿地增加了约122%.过去30年里湿地减少的速度大幅降低,由最初5523km2/a(1978～1990年)降为831km2/a(2000～2008年).(ⅲ)减少的自然湿地(包括滨海湿地和内陆湿地),其类型变化由湿地向非湿地转化的比例逐渐降低.初期(1978～1990年)几乎全部(98%)转换为非湿地;在1990～2000年间减少的自然湿地约有86%转化为非湿地,而在2000～2008年,这一比例下降为77%.(ⅳ)气候变化和农业活动是中国湿地变化的主要驱动因素,湿地变化在中国分为三大不同特征区域,即西部三省/自治区(西藏、新疆和青海)、北部两省/自治区(黑龙江和内蒙古)和其他省市区.其中西部区域尤其是青藏高原,湿地变化的驱动因子以气候增温为主;新疆湿地由于气候增温和农业活动共同作用造成变化不大.北部省/自治区的湿地变化则主要由农业活动引起;而其他省市区的湿地变化几乎完全受控于人类的农业经济活动

Solutions for wireless sensor network localization

Wireless sensor network localization opens the door to many location based applications. In this thesis, some solutions obtained from localization algorithms are investigated. There are two categories of problem on localization. Range-based methods are applied to the situation in which information on the distances between each pair of nodes is available. Algorithms are developed to estimate the location of each sensor in the network. Usually, the distance between each pair of nodes is estimated by the signal strength received between them, and this information is very noisy. Range-free methods, which are also called connectivity-based methods, assume that the distances between any two nodes are unknown but the connectivity information between them is known. If the distance between any two nodes in the network is within a communication range, connectivity between these two nodes is said to be established. In a range-based scenario, with the information of inter-sensor distance measurements as well as the absolute locations of the anchors, the objective is to obtain the location of all the unknown nodes. Two new localization methods based on gradient descent are shown in the thesis. The gradient descent methods would minimize the difference between the measured distances and the distances obtained from the estimated locations. From a comparison with other well-known localization methods, the two newly developed gradient descent algorithms can reach better accuracy at the expense of computational complexity. This is not surprising as the proposed algorithms are iterative in nature. For range-free scenario, a new model utilizing all the information derived from connectivity-based sensor network localization is introduced. Unlike other algorithms which only utilize the information on connections, this model makes use of both information on connections and disconnections between any pair of nodes. The connectivity information between any pair of nodes is modeled as convex and non-convex constraints. The localization problem is solved by an optimization algorithm to obtain a solution that would satisfy all the constraints established in the problem. The simulation has shown that better accuracy is obtained when compared with algorithms developed by other researchers. Another solution for the range-free scenario is obtained with the use of a two-objective evolutionary algorithm called Pareto Archived Evolution Strategy (PAES). In an evolutionary algorithm, the aim is to search for a solution that would satisfy all the convex and non-convex constraints of the problem. The number of wrong connections and the summation of corresponding distances are set as the two objectives. A starting point on the location of the unknown nodes is obtained using a solution from the result of all convex constraints. The final solution can reach the most suitable configuration of the unknown nodes as all the information on the constraints (convex and non-convex) related to connectivity have been used. From the simulation results, a relationship between the communication range and accuracy is obtained. In this thesis, another evolutionary algorithm has been examined to obtain a solution for our problem. The solution is based on a modified differential evolution algorithm with heuristic procedures peculiar to our domain of application. The characteristics of the sensor network localization are thoroughly investigated and utilized to produce corresponding treatment to search for the reasonable node locations. The modified differential evolution algorithm uses a new crossover step that is based on the characteristics of the problem. With the combination of some heuristics, the solution search can move the node to jump out of local minimums more easily, and give better accuracy than current algorithms. In the last part of the thesis, a novel two-level range connectivity-based sensor network localization problem is proposed, which would enrich the connectivity information. In this new problem, the information of the connectivity between any pair of nodes is either strong, weak or zero. Again, a two-objective evolutionary algorithm is used to search for a solution that would satisfy all the convex and non-convex constraints of the problem. Based on simulations on a range of situations, a suitable range value for the second range is found.published_or_final_versionElectrical and Electronic EngineeringDoctoralDoctor of Philosoph

基于ARM和DSP的CSR主环电源控制系统

介绍了基于ARM和DSP的CSR主环磁场电源控制系统的设计和开发。系统以以太网作为连接各个单元的传输介质,以ARM板卡作为以太网中的一个通信节点,由DSP板卡完成实际的电源控制。实验表明控制效果良好,超过了预期的设计目标

基于MSC1210和CPLD的电源测控模块的设计

介绍了采用MSC1210单片机,结合CPLD和DDS设计的一个电源测控模块,它通过RS-485总线实现与上位机的通信,来控制电源的开关、调节和状态获取等。实践表明,该模块具有较高的可靠性、实时性和适应性