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LB100 ameliorates nonalcoholic fatty liver disease via the AMPK/Sirt1 pathway

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World Journal of Gastroenterology 2019年第45期25卷 6607-6618页

作者： Xue-Yang Chen Chang-Zhou Cai Meng-Li Yu Ze-Min Feng Yu-Wei Zhang Pei-Hao Liu hang zeng Chao-Hui Yu Department of Gastroenterology The First Affiliated HospitalCollege of MedicineZhejiang UniversityHangzhou 310003Zhejiang ProvinceChina Clinical Research Center for Hepatobiliary and Pancreatic Diseases of Zhejiang Province Hangzhou 310003Zhejiang ProvinceChina

BACKGROUND It is well known that nonalcoholic fatty liver disease(NAFLD)is associated with insulin resistance(IR).LB100,a serine/threonine protein phosphatase 2A(PP2A)inhibitor,is closely related to IR.However,there is little data regarding its direct influence on NAFLD.AIM To elucidate the effect and underlying mechanism of LB100 in NAFLD.METHODS After 10 wk of high fat diet(HFD)feeding,male C57BL/6 mice were injected intraperitoneally with vehicle or LB100 for an additional 6 wk(three times a week).The L02 cell line was treated with LB100 and free fatty acids(FFAs)for 24 h.Hematoxylin and eosin and oil red O staining were performed for histological examination.Western blot analysis was used to detect the protein expression of Sirtuin 1(Sirt1),total and phosphorylated AMP-activated protein kinaseα(AMPKα),and the proteins involved in lipogenesis and fatty acid oxidation.The mRNA levels were determined by qPCR.Pharmacological inhibition of AMPK was performed to further examine the exact mechanism of LB100 in NAFLD.RESULTS LB100 significantly ameliorated HFD-induced obesity,hepatic lipid accumulation and hepatic injury in mice.In addition,LB100 significantly downregulated the protein levels of acetyl-CoA carboxylase,sterol regulatory element-binding protein 1 and its lipogenesis target genes,including stearoyl-CoA desaturase-1 and fatty acid synthase,and upregulated the levels of proteins involved in fatty acidβ-oxidation,such as peroxisome proliferator-activated receptorα(PPARα),peroxisome proliferator-activated receptor gamma coactivator-1α(PGC-1α),carnitine palmitoyltransferase 1α,acyl-CoA oxidase 1 and uncoupling protein 2,as well as the upstream mediators Sirt1 and AMPKαin the livers of HFD-fed mice.In vitro,LB100 alleviated FFA-induced lipid accumulation in L02 cells through the AMPK/Sirt1 signaling pathway.Further studies showed that the curative effect of LB100 on lipid accumulation was abolished by inhibiting AMPKαin L02 cells.CONCLUSION PP2A inhibition by LB100 significantly ameliorates hepatic steatosis

关键词： LB100 Nonalcoholic fatty liver disease Serine/threonine-protein phosphatase 2A Lipid metabolism AMP-activated protein kinaseα Sirtuin 1

定子通风槽钢结构对提高中型高压电机散热性能分析

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工程科学与技术 2024年第4期56卷 297-306页

作者：彭德其曾航殷伟周晓辉李广艾润谭卓伟湘潭大学机械工程与力学学院湖南湘潭411105 中车株洲电机有限公司湖南株洲412000

为降低YJK450-6、400kW中型高压电机的通风散热性能,本文对该电机不同通风槽钢结构进行了散热性能研究。首先,在现有电机的直线标准型通风结构基础上,提出单列缩放型、双列直线型、双列缩放型3种轴-径向混合通风结构形式;在SpaceClaim... 详细信息

为降低YJK450-6、400kW中型高压电机的通风散热性能,本文对该电机不同通风槽钢结构进行了散热性能研究。首先,在现有电机的直线标准型通风结构基础上,提出单列缩放型、双列直线型、双列缩放型3种轴-径向混合通风结构形式;在SpaceClaim软件中建立电机3维温度场数值计算模型,根据基本假设和边界条件结合电机内部热量传递公式计算出电机仿真设置参数,并导入Fluent软件进行仿真模拟,其中,计算温度场所用热源通过AnsoftMaxwell平台计算的电机损耗值获取。其次,通过网格无关性和温升试验验证本文建立的电机3维温度场数值计算模型;通过仿真模拟对比分析3种轴-径向混合通风结构与直线标准型结构对电机流场和温度场的影响;采用正交试验法对轴-径向混合通风结构进行参数优化,得到最佳散热结构和参数方案;进一步探究冷却风速对双列缩放型槽钢的电机换热性能的影响;结合定子绕组温升和电机整体的温升均匀性系数,对最佳散热结构和参数方案电机进行散热效果评价。仿真结果表明:本文建立的计算模型是有效的;双列缩放型通风槽钢结构的各项散热性能指标均最好,是最优通风槽钢结构;径向风道高度为6mm且数量为13的双列缩放型通风槽钢结构为最佳散热结构和参数方案;双列缩放型通风槽钢结构两侧的平均对流换热系数随冷却风速增大而增大,且槽钢迎风面的平均对流换热系数明显大于背风面;径向风道高度为6mm且数量为13的双列缩放型通风槽钢结构电机的内/外层绕组温升分布均匀性系数比直线标准型电机分别提高88.13%、20.11%。因此,优化设计通风槽钢结构有利于电机内部空气流动和散热,可实现有效降低电机内部温升的目的。

关键词：中型高压电机轴-径向混合通风结构通风槽钢径向风道温升

Allyl isothiocyanate ameliorates lipid accumulation and inflammation in nonalcoholic fatty liver disease via the Sirt1/AMPK and NF-κB signaling pathways

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World Journal of Gastroenterology 2019年第34期25卷 5120-5133页

作者： Chun-Xiao Li Jian-Guo Gao Xing-Yong Wan Yi Chen Cheng-Fu Xu Ze-Min Feng hang zeng Yi-Ming Lin Han Ma Ping Xu Chao-Hui Yu You-Ming Li Department of Gastroenterology the First Affiliated HospitalCollege of MedicineZhejiang UniversityHangzhou 310003Zhejiang ProvinceChina Clinical Research Center for Hepatobiliary and Pancreatic Diseases of Zhejiang Province Hangzhou 310003Zhejiang ProvinceChina

BACKGROUND Allyl isothiocyanate(AITC),a classic anti-inflammatory and antitumorigenic agent,was recently identified as a potential treatment for obesity and insulin resistance.However,little is known about its direct impact on the liver.AIM To investigate the effect and underlying mechanism of AITC in nonalcoholic fatty liver disease(commonly referred to as NAFLD).METHODS To establish a mouse and cellular model of NAFLD,C57BL/6 mice were fed a high fat diet(HFD)for 8 wk,and AML-12 cells were treated with 200μM palmitate acid for 24 h.For AITC treatment,mice were administered AITC(100 mg/kg/d)orally and AML-12 cells were treated with AITC(20μmol/L).RESULTS AITC significantly ameliorated HFD-induced weight gain,hepatic lipid accumulation and inflammation in vivo.Furthermore,serum alanine aminotransferase and aspartate aminotransferase levels were markedly reduced in AITC-treated mice.Mechanistically,AITC significantly downregulated the protein levels of sterol regulatory elementbinding protein 1(SREBP1)and its lipogenesis target genes and upregulated the levels of proteins involved in fatty acidβ-oxidation,as well as the upstream mediators Sirtuin 1(Sirt1)and AMPactivated protein kinaseα(AMPKα),in the livers of HFD-fed mice.AITC also attenuated the nuclear factor kappa B(NF-κB)signaling pathway.Consistently,AITC relieved palmitate acid-induced lipid accumulation and inflammation in AML-12 cells in vitro through the Sirt1/AMPK and NF-κB signaling pathways.Importantly,further studies showed that the curative effect of AITC on lipid accumulation was abolished by siRNA-mediated knockdown of either Sirt1 or AMPKαin AML-12 cells.CONCLUSION AITC significantly ameliorates hepatic steatosis and inflammation by activating the Sirt1/AMPK pathway and inhibiting the NF-κB pathway.Therefore,AITC is a potential therapeutic agent for NAFLD.

关键词： Allyl isothiocyanate Nonalcoholic fatty liver disease Hepatic steatosis Liver inflammation

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基于多机构属性加密的云数据确定性删除方案

计算机技术与发展 2024年第1期34卷 91-98页

作者：江艳惠胡学先陈越郝增航郑州大学网络空间安全学院河南郑州450002 中国人民解放军战略支援部队信息工程大学河南郑州450001

云存储服务的使用越来越普遍,但是将大量数据存储在第三方云服务器中,给用户带来便利的同时也提出了更高的安全要求。由于云存储服务是半可信的,使得如何确定性删除云存储数据成为需要解决的问题。目前,云存储数据的确定性删除的相关研... 详细信息

云存储服务的使用越来越普遍,但是将大量数据存储在第三方云服务器中,给用户带来便利的同时也提出了更高的安全要求。由于云存储服务是半可信的,使得如何确定性删除云存储数据成为需要解决的问题。目前,云存储数据的确定性删除的相关研究大多基于单机构管理属性的属性基加密,该类方案虽然满足云数据的细粒度访问控制,但容易引起单点故障等问题。因此,提出一种基于多机构属性基加密的云存储数据确定性删除方案。将多机构属性基加密应用于该方案,不仅支持有多个机构管理属性时对云存储数据的安全删除,并实现了云数据的细粒度访问。此外,该方案通过利用策略隐藏保护存储在云服务器中的访问策略的隐私。最后,通过撤销属性改变密文实现云数据删除,并通过区块链存储删除证明实现删除结果公开可验证和责任可追溯。实验仿真和对比分析表明,该方案在云存储数据删除方面具有较高的安全性,为云储存数据的删除提供一种实用方案。

关键词：云存储确定性删除多机构属性基加密区块链策略隐藏

大型永磁同步电机内外双循环强化散热性能模拟

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湖南大学学报（自然科学版） 2024年第6期51卷 195-203页

作者：彭德其曾航张治坤殷伟晏才松李广谭卓伟张建平湘潭大学机械工程与力学学院湖南湘潭411105 湖南化工职业技术学院湖南株洲412000 中车株洲电力机车有限公司湖南株洲412000

针对高铁大型永磁同步牵引电机转子区域散热困难、内部温升分布不均匀的问题,在机壳水冷电机结构基础上的定子铁芯外表面处增设轴向矩形风道,并结合气隙、转子减重孔形成内外双循环散热结构,探究降低定子、绕组部位温升和提升电机内部... 详细信息

针对高铁大型永磁同步牵引电机转子区域散热困难、内部温升分布不均匀的问题,在机壳水冷电机结构基础上的定子铁芯外表面处增设轴向矩形风道,并结合气隙、转子减重孔形成内外双循环散热结构,探究降低定子、绕组部位温升和提升电机内部散热均匀性的影响规律.首先通过Ansoft Maxwell平台仿真得到双循环散热结构在额定工况下各部件损耗值,同时为了更好模拟转子旋转带动气隙中的空气流动,对气隙进行分层处理,采用流-固耦合的有限元分析法模拟研究单、双循环散热结构下电机内部空气流动特性以及温升规律.结果表明,内循环风冷结构使电机内部空气流速显著提高,表面平均换热系数也显著提升,转子区域的热量会随着空气的流动更多地传给温度相对较低的定子区域及机壳,同时减少热量向转子部位传递,从而使转子和永磁体的温升降低.在此基础上,采用正交分析法对矩形通风孔的截面积、数量、高宽比进行结构参数优化,并采用温升分布均匀性系数对电机进行温升评价,得到最优方案下电机最高温升相比单循环散热结构降低12.1K,电机整体温升分布均匀性提升16.54%.

关键词：永磁同步电机流固耦合强化散热流体场温度场风道

基于PSO的新安江模型对资水流域柘桃区间洪水预报研究

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人民珠江 2024年第S1期45卷 175-185,200页

作者：曾杭易祖新黄草刘时旺周洋长沙理工大学水利与环境工程学院湖南长沙410114 长沙理工大学洞庭湖水环境治理与生态修复湖南省重点实验室湖南长沙410114 长沙理工大学水沙科学与水灾害防治湖南省重点实验室湖南长沙410114

无资料地区的洪水预报研究是当前水文研究的热点内容。资水流域柘桃区间是湖南省三大暴雨中心之一,产生的洪水占整个资水流域近60%。柘桃区间受客观条件限制无实测洪水资料,基于区间实测降水量数据,构建基于粒子群参数优化算法(PSO)的... 详细信息

无资料地区的洪水预报研究是当前水文研究的热点内容。资水流域柘桃区间是湖南省三大暴雨中心之一,产生的洪水占整个资水流域近60%。柘桃区间受客观条件限制无实测洪水资料,基于区间实测降水量数据,构建基于粒子群参数优化算法(PSO)的新安江三水源模型进行洪水预报,提高预报精度并计算此地区设计洪水保障防洪安全。结果表明:22场实测洪水率定和10场实测洪水验证的洪水预报精度均较高,基于PSO优化算法的新安江模型模拟效果较优;随着重现期增大,考虑柘桃区间与上游柘溪水库的最不利洪水组合,得到的资水流域控制站桃江站设计洪峰大于站点实测洪水计算得到的设计洪峰。研究结果可为资水流域柘桃区间梯级电站合理调度提供方案设计依据,为资水下游防洪安全和发电效益提供技术支持。

关键词： PSO算法洪水预报设计洪水资水流域柘桃区间

Capacitor Voltage Imbalance Mechanism and Balancing Control of MMC When Riding Through PTG Fault

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 778-785页

作者： Zhen He Maozeng Lu Lijun hang Pingliang zeng Yanhua Liu hangzhou Dianzi University Hangzhou 310018China Shandong University of Technology Zibo 255000China State Grid hangzhou Power Supply Company State GridHangzhou 310000China

Modular multilevel converter (MMC) based fault ride through (FRT) control is a promising solution to deal with the pole-to-ground (PTG) fault in high voltage direct current (HVDC) system. However, when MMC switches to the FRT control, capacitor voltage imbalance between upper and lower arms will occur, resulting in the deterioration of FRT performance. This letter provides a comprehensive analysis for the imbalance issue from the perspective of fundamental frequency circulating current (FFCC). It is found the imbalance during FRT stage will not expand continuously, but converge to a certain value gradually. The specific imbalance degree is closely associated with the amplitude of FFCC. In order to solve the imbalance issue, an open-loop balancing control is proposed. By introducing a fundamental frequency feedforward item to the inherent circulating current control, the proposed method can not only balance the capacitor voltages, but also minimize the amplitude of FFCC, and consequently the power loss of MMC during FRT process can be reduced. Finally, simulation results of PSCAD/ EMTDC verify the validity of theoretical analysis.

关键词： Balancing control capacitor voltage imbalance FFCC FRT control HVDC system PTG fault

Regulation of rhizosphere microenvironment by rice husk ash for reducing the accumulation of cadmium and arsenic in rice

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Journal of Environmental Sciences 2024年第2期136卷 1-10页

作者： Yi Jiang Ya Liu Xuantao Yi Peng zeng Bohan Liao hang Zhou Jiaofeng Gu College of Environmental Science and Engineering Central South University of Forestry and TechnologyChangsha 410004China Hunan Engineering Laboratory for Control of Rice Quality and Safety Changsha 410004China

It is important to reduce Cd and As content in brown rice in contaminated paddy soils.We conducted research on the effects of rice husk ash (RHA) on the Cd and As in the rhizosphere microenvironment (soil,porewater,and iron plaque) and measured the Cd,As,and Si content in rice plants.The main elements in RHA were Si (29.64%) and O (69.17%),which had the maximum adsorption capacity for Cd was 42.49 mg/kg and for As was 18.62 mg/kg.Soil pH and available Si content increased,while soil available Cd and As decreased following application of 0.5%–2%RHA.RHA promote the transformation of Cd to insoluble fraction,while As was transformed from a poorly soluble form to a more active one.RHA reduced Cd content and increased Si content in porewater,and reduced As only at the later rice growth stages.RHA increased the amount of iron plaque,thereby decreasing the Cd content in iron plaque,while increased the As content in it.Cd and inorganic As content in brown rice were decreased,to 0.31 mg/kg and 0.18 mg/kg,respectively.The decrease of Cd in brown rice was due to the decrease of Cd mobility in soil,thereby reducing root accumulation,while the decrease of As in brown rice was affected by the transport from roots to stems.Therefore,RHA can be considered as a safe and efficient in-situ remediation amendment for Cd and As co-contaminated paddy soil.

关键词： Rice husk ash(rha) Cadmium Arsenic Silicon Rice Soil

Intelligent Predetermination of Generator Tripping Scheme: Knowledge Fusion-based Deep Reinforcement Learning Framework

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CSEE Journal of Power and Energy Systems 2024年第1期10卷 66-75页

作者： Lingkang zeng Wei Yao Ze Hu hang Shuai Zhouping Li Jinyu Wen Shijie Cheng State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronics EngineeringHuazhong University of Science and TechnologyWuhan 430074China Dispatching and Control Center Central China Branch of State Grid Corporation of ChinaWuhan 430077China. Department of Electrical Engineering and Computer Science University of TennesseeKnoxvilleTN 37996USA

Generator tripping scheme(GTS)is the most commonly used scheme to prevent power systems from losing safety and stability.Usually,GTS is composed of offline predetermination and real-time scenario match.However,it is extremely time-consuming and labor-intensive for manual predetermination for a large-scale modern power system.To improve efficiency of predetermination,this paper proposes a framework of knowledge fusion-based deep reinforcement learning(KF-DRL)for intelligent predetermination of GTS.First,the Markov Decision Process(MDP)for GTS problem is formulated based on transient instability events.Then,linear action space is developed to reduce dimensionality of action space for multiple controllable generators.Especially,KF-DRL leverages domain knowledge about GTS to mask invalid actions during the decision-making process.This can enhance the efficiency and learning process.Moreover,the graph convolutional network(GCN)is introduced to the policy network for enhanced learning ability.Numerical simulation results obtained on New England power system demonstrate superiority of the proposed KF-DRL framework for GTS over the purely data-driven DRL method.

关键词： Deep reinforcement learning generator tripping scheme graph convolutional network invalid action masking knowledgefusion