检索结果-南通市图书馆

New insights into the role of spermine in enhancing the antioxidant capacity of rat spleen and liver under oxidative stress

在线全文

学校读者我要写书评

暂无评论

Animal Nutrition 2017年第1期3卷 85-90页

作者： Xianjian Wu Wei Cao Gang Jia Hua Zhao Xiaoling Chen Caimei wu Jiayong Tang Jing Wang Guangmang Liu Institute of Animal Nutrition Sichuan Agricultural University Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education Maize Research Institute Sichuan Agricultural University

Oxidative stress can damage cellular antioxidant defense and reduce livestock production efficiency.Spermine is a ubiquitous cellular component that plays important roles in stabilizing nucleic acids,modulating cell growth and differentiation, and regulating ion channel activities. Spermine has the potential to alleviate the effects of oxidative stress. However, to date no information is available about the effect of spermine administration on antioxidant property of the liver and spleen in any mammalian in vivo system. This study aims to investigate the protective effect of spermine on rat liver and spleen under oxidative stress. Rats received intragastric administration of either 0.4 μmol/g body weight of spermine or saline once a day for 3 days. The rats in each treatment were then injected with either diquat or sterile saline at 12 mg/kg body weight. Liver and spleen samples were collected 48 h after the last spermine ingestion.Results showed that regardless of diquat treatment, spermine administration significantly reduced the malondialdehyde(MDA) content by 23.78% in the liver and by 5.75% in the spleen, respectively(P < 0.05).Spermine administration also enhanced the catalase(CAT) activity, anti-hydroxyl radical(AHR) capacity and glutathione(GSH) content by 38.68%, 15.53% and 1.32% in the spleen, respectively(P< 0.05). There were interactions between spermine administration and diquat injection about anti-superoxide anion(ASA),AHR capacity, CAT activity, GSH content, and total antioxidant capacity(T-AOC) in the liver and about ASA capacity and T-AOC in the spleen of weaned rats(P < 0.05). Compared with the control group, spermine administration significantly increased the AHR capacity, CAT activity, GSH content, and T-AOC by 40.23%,31.15%, 30.25%, 35.37% in the liver, respectively(P < 0.05) and increased the T-AOC by 8% in the spleen of weaned rats(P < 0.05). Compared with the diquat group, spermine + diquat group significantly increased ASA capacity by 15.63% in the liver and by 73.41% in the spleen of we

关键词： Spermine Oxidative stress Antioxidant capacity Spleen Liver

Roles of dietary supplementation with arginine or N-carbamylglutamate in modulating the inflammation, antioxidant property, and m RNA expression of antioxidant-relative signaling molecules in the spleen of rats under oxidative stress

在线全文

学校读者我要写书评

暂无评论

Animal Nutrition 2018年第3期4卷 322-328页

作者： Weiwei Mo Xianjian Wu Gang Jia Hua Zhao Xiaoling Chen Jiayong Tang Caimei wu Jingyi Cai Gang Tian Jing Wang Gangmang Liu Institute of Animal Nutrition Sichuan Agricultural University Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education Maize Research Institute Sichuan Agricultural University

This study evaluated the effects of arginine(Arg) or N-carbamylglutamate(NCG) on inflammation, antioxidant property, and antioxidant-related gene expression in rat spleen under oxidative stress. A total of 52 rats were randomly distributed into 4 treatment groups with 13 replicates per group. Rats were fed a basal diet(BD) or BD supplemented with Arg or NCG for 30 days. On day 28, half of the BD-fed rats were intraperitoneally injected with sterile saline(control group), and the other half with 12 mg/kg body weight of diquat(DT; DT group). The other 2 diet groups were intraperitoneally injected with 12 mg/kg body weight of DT with either Arg(1%)(DT t Arg) or NCG(0.1%)(DT t NCG). Rat spleen samples were collected for analysis at 48 h after DT injection. Results showed that DT damaged the antioxidant defense in rats compared with the control group(P < 0.05). Compared with the DT group, the DT t Arg and DT t NCG groups manifested improved anti-hydroxyl radical, catalase, and total superoxide dismutase(T-SOD) activities, increased glutathione content(P < 0.05), and decreased malondialdehyde content(P < 0.05).Moreover, compared with the DT group, the DT t Arg and DT t NCG groups enhanced mRNA expression of superoxide dismutase(SOD), glutathione peroxidase 1(GPx1), glutathione reductase(GR), nuclear factor erythroid 2-related factor 2(Nrf2), Kelch-like ECH-associated protein 1(Keap-1), and mammalian target of rapamycin(m TOR)(P < 0.05). Both NCG and Arg significantly increased anti-inflammatory cytokine mRNA level but suppressed the pro-inflammatory cytokine mRNA expression under oxidative stress(P < 0.05). In summary, NCG and Arg effectively alleviated oxidative stress, improved the antioxidant capacity and regulated the antioxidant-related signaling molecular expression in rat spleen. N-carbamylglutamate and Arg reduced the inflammation in the spleen by mediating the gene expression of anti-inflammatory and pro-inflammatory cytokines and transforming growth factor-β(TGF-β).

关键词： Arginine N-carbamylglutamate Antioxidant property Signaling molecule Inflammation Spleen

Arginine, N-carbamylglutamate,and glutamine exert protective effects against oxidative stress in rat intestine

在线全文

学校读者我要写书评

暂无评论

Animal Nutrition 2016年第3期2卷 242-248页

作者： Liang Xiao Wei Cao Guangmang Liu Tingting Fang Xianjian Wu Gang Jia Xiaoling Chen Hua Zhao Jing Wang Caimei wu Jingyi Cai Institute of Animal Nutrition Sichuan Agicultural University Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education Maize Research Institute Sichuan Agricultural University

The objective of the current study is to evaluate the effects of dietary supplementation with arginine(ARG), N-carbamylglutamate(NCG), and glutamine(GLN) on rat intestinal morphology and antioxidant status under oxidative stress. Rats were fed for 30 d with one of the following iso-nitrogenous diets:basal diet(BD), BD plus 1% ARG, BD plus 0.1% NCG, and BD plus 1% GLN. On day 28, half of the rats fed BD were intraperitoneally injected with 12 mg/kg body weight of diquat(DT; i.e., the DT group) and the other half was intraperitoneally injected with sterile solution(i,e., the control group). The other diet groups were intraperitoneally injected with 12 mg/kg body weight of DT(i,e., DT + 1% GLN [DT + GLN],DT + 1% ARG [DT + ARG], and DT + 0.1% NCG [DT + NCG]). Rat jejunum samples obtained at 48 h after DT injection were analyzed. Results showed that DT significantly decreased catalase(CAT) activity and glutathione(GSH) content by 58.25% and 56.57%, respectively, and elevated malondialdehyde(MDA)content and crypt depth(CD) by 19.39% and 22.13%, respectively, in the jejunum(P < 0.05, relative to the control group). Compared with the DT group, the DT + GLN group exhibited significantly improved villus height(VH), villus width(VW), villus surface area(VSA), CD and total antioxidant capacity(T-AOC) activity(P < 0.05); the DT + ARG group exhibited significantly increased the ratio of VH to CD(H:D) and TAOC activity(P < 0.05); the DT + GLN, DT + ARG and DT + NCG groups exhibited significantly enhanced CAT activity and GSH content as well as decreased MDA content(P < 0.05). Moreover, VH, VW, VSA, CD and GSH content in the DT + GLN group were higher whereas MDA content was lower compared with the corresponding values observed in both the DT + ARG and the DT + NCG groups(P < 0.05). The H:D ratio in the DT + ARG group significantly increased compared with that in the DT + NCG and DT + GLN groups(P < 0.05). Collectively, this study suggested that dietary supplementation with 1% GLN, 0.1% NCG,and 1% ARG was effective in enhancing

关键词： Arginine Glutamine N-Carbamylglutamate Oxidative stress Jejunum Antioxidant status

在线全文

学校读者我要写书评

暂无评论

气相法纳米氧化铝对聚酯型粉末涂料的影响

涂料工业 2024年第6期54卷 8-14页

作者：张家宇谢楠段先健吴春蕾广州汇富研究院有限公司广州510663

为了系统讨论气相法氧化铝对粉末涂料的影响,研究了气相法氧化铝的比表面积和添加量对粉末涂料性能的影响,使用扫描电子显微镜(SEM)、能谱仪(EDS)和金相显微镜观察了氧化铝在体系中的分散状态和漆膜的表面微观形貌,测试了粉末流速、光... 详细信息

为了系统讨论气相法氧化铝对粉末涂料的影响,研究了气相法氧化铝的比表面积和添加量对粉末涂料性能的影响,使用扫描电子显微镜(SEM)、能谱仪(EDS)和金相显微镜观察了氧化铝在体系中的分散状态和漆膜的表面微观形貌,测试了粉末流速、光泽、粗糙度等性能指标,并对气相法氧化铝提升粉末涂料上粉率、耐磨性的机理进行了分析。结果表明:气相法氧化铝在粉末涂料中存在影响漆膜上粉率、机械性能的添加量阈值,该值受气相法氧化铝比表面积的影响。粉末涂料用气相法氧化铝比表面积应高于70 m^(2)/g,不同添加量对粉末涂料的影响不同,低添加量(0.1%)主要表现为提升粉末带电性能,中添加量(0.3%)主要表现为提升粉末涂料流动性,高添加量(0.6%)下氧化铝表现为减弱静电屏蔽效应,提升漆膜强度。

关键词：气相法氧化铝聚酯型粉末涂料比表面积添加量

在线全文

学校读者我要写书评

暂无评论

耐磨蚀钢BMS1400焊接性能研究

热加工工艺 2023年第1期52卷 113-118页

作者：宋凤明温东辉伍先见宝山钢铁股份有限公司研究院上海201900 上海连山金属材料有限公司技术部上海200940

采用埋弧焊方法对比了不同强度焊丝焊接耐磨蚀钢BMS1400的焊接性能。较低强度的50、60 kg焊丝焊接样板具有相近的接头拉伸强度,抗拉强度均超过了600 MPa;80 kg焊丝的接头抗拉强度则超过760 MPa。焊接样板均具有良好的冷弯性能,但在冷弯... 详细信息

采用埋弧焊方法对比了不同强度焊丝焊接耐磨蚀钢BMS1400的焊接性能。较低强度的50、60 kg焊丝焊接样板具有相近的接头拉伸强度,抗拉强度均超过了600 MPa;80 kg焊丝的接头抗拉强度则超过760 MPa。焊接样板均具有良好的冷弯性能,但在冷弯位置存在应变集中,高强度焊丝有利于降低焊接接头的应变集中。焊接接头的低温冲击韧性随着焊丝强度的提高而提高。在19.6~22.3 kJ/cm焊接热输入量条件下,50、60 kg焊丝的焊接接头均存在明显的焊接软化和硬度峰值;而80 kg焊丝焊接的接头硬度更为均匀。焊接热影响区的组织与距离焊缝的远近有关,靠近焊缝及HAZ中心均为板条状铁素体+少量马氏体组织,而靠近母材则为类似高温回火的带状铁素体+珠光体组织。采用更高强度焊丝的样板具有更好的低温冲击韧性,并且应变集中降低,从而获得更好的焊接接头性能。

关键词：耐磨蚀钢焊接性能埋弧焊

基于IPA分析延安大学杨家岭校园的绿地景观

在线全文

学校读者我要写书评

暂无评论

延安大学学报（自然科学版） 2022年第4期41卷 78-82页

作者：吴云霄袁阅刘先健延安大学生命科学学院陕西延安716000

为合理评价并积极提升校园绿地景观质量。以延安大学杨家岭校区校园绿地为研究对象,在实地调查和会聚式深度访谈的基础上,建立校园绿地景观评价体系。在问卷调查的基础上,利用IPA分析法对校园6大区域的绿地景观进行评价分析。结果显示:... 详细信息

为合理评价并积极提升校园绿地景观质量。以延安大学杨家岭校区校园绿地为研究对象,在实地调查和会聚式深度访谈的基础上,建立校园绿地景观评价体系。在问卷调查的基础上,利用IPA分析法对校园6大区域的绿地景观进行评价分析。结果显示:校园各个区域的满意度一般,特别是校园绿地中植物景观和景观小品及标志物是需要改善的重点。植物景观方面需要在植物的丰富度、常绿落叶植物的配置比例、季相变化以及疏密搭配等方面重点改善;景观小品及标志物主要从种类、美观度和建造质量方面进行重点改善。

关键词：延安大学校园绿地满意度重要度 IPA分析

Combined Estimation of Vehicle Dynamic State and Inertial Parameter for Electric Vehicles Based on Dual Central Difference Kalman Filter Method

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2023年第4期36卷 339-354页

作者： xianjian Jin Junpeng Yang Liwei Xu Chongfeng Wei Zhaoran Wang Guodong Yin School of Mechatronic Engineering and Automation Shanghai UniversityShanghai 200072China State Key Laboratory of Automotive Simulation and Control Jilin UniversityChangchun 130025China School of Mechanical Engineering Southeast UniversityNanjing 211189China Mechanical and Construction Engineering Northumbria UniversityNewcastle NE18STUK

Distributed drive electric vehicles(DDEVs)possess great advantages in the viewpoint of fuel consumption,environment protection and traffic mobility.Whereas the effects of inertial parameter variation in DDEV control system become much more pronounced due to the drastic reduction of vehicle weights and body size,and inertial parameter has seldom been tackled and systematically estimated.This paper presents a dual central difference Kalman filter(DCDKF)where two Kalman filters run in parallel to simultaneously estimate vehicle different dynamic states and inertial parameters,such as vehicle sideslip angle,vehicle mass,vehicle yaw moment of inertia,the distance from the front axle to centre of gravity.The proposed estimation method only integrates and utilizes real-time measurements of hub torque information and other in-vehicle sensors from standard DDEVs.The four-wheel nonlinear vehicle dynamics estimation model considering payload variations,Pacejka tire model,wheel and motor dynamics model is developed,the observability of the DCDKF observer is analysed and derived via Lie derivative and differential geometry theory.To address system nonlinearities in vehicle dynamics estimation,the DCDKF and dual extended Kalman filter(DEKF)are also investigated and compared.Simulation with various maneuvers are carried out to verify the effectiveness of the proposed method using Matlab/Simulink-CarsimR.The results show that the proposed DCDKF method can effectively estimate vehicle dynamic states and inertial parameters despite the existence of payload variations and variable driving conditions.This research provides a boot-strapping procedure which can performs optimal estimation to estimate simultaneously vehicle system state and inertial parameter with high accuracy and real-time ability.

关键词： Distributed drive Electric vehicle State observation Inertial parameter Dual central difference Kalman filter

行动者网络视角下贵州民族传统节庆文化品牌构建与传播研究——以雷山苗年为例

在线全文

学校读者我要写书评

暂无评论

新闻研究导刊 2022年第14期13卷 63-65页

作者：廖慧罗奥搏吴显剑贵州财经大学贵州贵阳550025

苗年是贵州雷山苗族同胞最重要的节日,2008年经国务院批准列入第二批国家级非物质文化遗产名录。几十年来,在政府的主导与支持下,苗年成为雷山县的知名品牌,成为当地文化发展、经济增长的重要助推器。文章通过田野调查发现,雷山苗年品... 详细信息

苗年是贵州雷山苗族同胞最重要的节日,2008年经国务院批准列入第二批国家级非物质文化遗产名录。几十年来,在政府的主导与支持下,苗年成为雷山县的知名品牌,成为当地文化发展、经济增长的重要助推器。文章通过田野调查发现,雷山苗年品牌的构建与传播过程不单是政府、企业等“人”的行动,而是由“人”与“物”所共同建构的。由此,从拉图尔行动者网络理论的视角,聚焦雷山苗年品牌构建与传播过程,发现整合人类行动者和非人类行动者是关键,需要改变创新环境、合作方式和优化利益分配模式来优化其发展动力机制。文章最后进一步提出苗年品牌的发展需要挖掘民族节庆文化内涵建立独特品牌识别,以及通过跨媒体整合传播来扩大民族节庆品牌知名度。

关键词：雷山苗年行动者网络品牌构建品牌传播品牌识别

基于熵权TOPSIS和耦合协调模型的四川省土地利用效益耦合协调关系及时空演变特征

在线全文

学校读者我要写书评

暂无评论

水土保持学报 2024年第1期38卷 267-277页

作者：谢贤健内江师范学院地理与资源科学学院四川内江641112

[目的]从社会、经济、生态环境3个方面评价区域土地利用效益及其耦合关系有利于实现土地资源的合理配置及优化用地结构。[方法]以四川省21个地市州为研究对象,利用熵权TOPSIS法和耦合协调度模型,构建了2010—2020年四川省土地利用效益... 详细信息

[目的]从社会、经济、生态环境3个方面评价区域土地利用效益及其耦合关系有利于实现土地资源的合理配置及优化用地结构。[方法]以四川省21个地市州为研究对象,利用熵权TOPSIS法和耦合协调度模型,构建了2010—2020年四川省土地利用效益的综合评价体系,并基于GIS技术,分析了土地利用的社会、经济、生态环境效益及其耦合协调关系的时空演变特征。[结果](1)四川省各地市州的土地利用综合效益整体上呈上升趋势,空间上具有“西北高东南低”的空间格局;土地利用的经济、生态环境效益整体上具有上升趋势,分别表现为“西高东低”和“中东部高西部低”的空间格局;土地利用社会效益整体上呈下降趋势,具有“中部高两翼低”的空间格局;三大效益在空间均具有较显著的聚集特征。(2)四川省各地市州的土地利用耦合协调等级为4个,总体协调水平不高,以勉强协调为主,其次是濒临失调,具有“中间高两翼低”的空间格局,且耦合等级相同的城市聚集度较高,土地利用效益耦合协调等级在空间分布上需进一步改善。(3)影响四川省地利用效益大小的因子依次为社会>经济>社会经济>社会生态>生态环境效益系统;土地利用效益耦合协调关系主要受社会、经济效益单一因子影响,其次是社会经济复合因素,最后是社会生态复合因素的影响。[结论]四川省各地市州的土地利用综合效益整体上呈上升趋势,区域差异显著,总体的耦合协调水平处于较低等级,且耦合等级相同的城市聚集度较高,在今后的发展中应该调控城镇化的无序扩张,注重城市基础公共服务等设施的建设,增加城市环境建设投入,促进四川省土地经济效益-社会效益-生态环境效益间的协调发展,以期为提升四川省土地利用综合效益提供参考。

关键词：四川省土地利用效益时空耦合地理信息系统