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一种基于LMI的H_-/H_∞故障检测观测器优化设计方法

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中南大学学报（自然科学版） 2004年第4期35卷 628-631页

作者：彭涛桂卫华 steven X d 吴敏李昊中南大学信息科学与工程学院 Institute for Automatic Control and Complex Systems University of Duisburg-Essen

针对线性时不变动态系统,构造一个线性全阶输出观测器,获得包括扰动、噪声、建模误差等未知输入信号和故障信号的残差动态特性,选用残差对故障信号的H-指数描述其对故障的灵敏度,用残差对未知信号的H∞范数表示其对不确定因素的鲁棒性,... 详细信息

针对线性时不变动态系统,构造一个线性全阶输出观测器,获得包括扰动、噪声、建模误差等未知输入信号和故障信号的残差动态特性,选用残差对故障信号的H-指数描述其对故障的灵敏度,用残差对未知信号的H∞范数表示其对不确定因素的鲁棒性,将故障检测观测器的设计描述为一个优化问题。研究了基于线性矩阵不等式的故障检测观测器设计,给出了求解最优观测器增益的方法,并证明了该解存在的条件。实践结果表明,应用该方法所设计的故障检测观测器灵敏度高,对干扰信号具有强鲁棒性。

关键词：故障检测观测器鲁棒性灵敏度线性矩阵不等式

Poor maternal nutrition inhibits muscle development in ovine offspring

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Journal of Animal Science and Biotechnology 2015年第1期6卷 79-89页

作者： Sarah A Reed Joseline S Raja Maria L Hoffman steven A Zinn Kristen E Govoni department of Animal Science University of ConnecticutStorrsCT 06269USA

Background： Maternal over and restricted nutrition has negative consequences on the muscle of offspring by reducing muscle fiber number and altering regulators of muscle growth. To determine if over and restricted maternal nutrition affected muscle growth and gene fed 60%, 100% or 140% of National Research Council and protein expression in offspring, 36 pregnant ewes were requirements from d 31 ＋ 1,3 of gestation until parturition. Lambs from control-fed （CON）, restricted-fed （RES） or over-fed （OVER） ewes were necropsied within 1 d of birth （n = 18） or maintained on a control diet for 3 mo （n = ] 5）. Semitendinosus muscle was collected for immunohistochemistry, and protein and gene expression analysis. Results： Compared with CON, muscle fiber cross-sectional area （CSA） increased in RES （58%） and OVER （47%） lambs at 1 d of age （P〈 0.01）; however at 3 mo, CSA decreased 15% and 17% compared with CON, respectively （P 〈 0.01）. Compared with CON, muscle lipid content was increased in OVER （212.4%） and RES （92.5%） at d 1 （P 〈 0.0001）. Muscle lipid content was increased 36.1% in OVER and decreased 23.6% in RES compared with CON at 3 mo （P 〈 0.0001）. At d 1, myostatin mRNA abundance in whole muscle tended to be greater in OVER （P = 0.07） than CON. Follistatin mRNA abundance increased in OVER （P = 0.04） and tended to increase in RES （P = 0.06） compared with CON at d 1. However, there was no difference in myostatin or follistatin protein expression （P 〉 0.3）. Phosphorylated Akt （ser473） was increased in RES at 3 mo compared with CON （P = 0.006）. Conclusions： In conclusion, maternal over and restricted nutrient intake alters muscle lipid content and growth of offspring, possibly through altered gene and protein expression.

关键词： Growth Maternal nutrition Muscle development Sheep

Nanoindentation in elastoplastic materials:insights from numerical simulations

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International Journal of Smart and Nano Materials 2010年第2期1卷 95-114页

作者： steven W.Moore Majid T.Manzari Yin-Lin Shen department of Mechanical and Aerospace Engineering The George Washington UniversityWashingtonDC 20052USA department of Civil and Environmental Engineering The George Washington UniversityWashingtonDC 20052USA

Finite element simulations of nanoindentation were performed on an elastoplastic material using Berkovich and conical indenters to investigate the effects of geometry on the load-displacement response of the *** Berkovich indenter,widely used in nanoindentation experiments,is typically simplified to a theoretically equivalent 70.3°conical indenter for numerical simulations,which allows for a less computationally intensive two-dimensional(2d)axisymmetric *** studies into the validity of this equivalence assumption for indentations in elastoplastic materials have varying *** 2d and 3d finite element simulations,the present study investigates the response of elastoplastic materials,obeying a combined isotropic and kinematic hardening,to indentation with conical and Berkovich *** show that there is a clear difference in the load-displacement response of the selected material to the two *** Berkovich geometry is found to produce a more localized pattern of contact stresses and plastic strains,leading to a smaller mobilized force for the same magnitude of *** further validate the numerical simulations,experimental results of nanoindentation into an aluminium specimen were compared to elastoplastic finite element simulation *** suggest that machining-induced residual stresses have likely affected the experimental results.

关键词： nanoindentation finite element analysis elastoplasticity tip geometry

Metabolic pathways as possible therapeutic targets for progressive multiple sclerosis

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Neural Regeneration Research 2017年第8期12卷 1262-1267页

作者： Rebecca M.Heidker Mitchell R.Emerson steven M.Le Vine department of Molecular and Integrative Physiology University of Kansas Medical Center department of Pharmaceutical Sciences College of Pharmacy-Glendale Midwestern University

Unlike relapsing remitting multiple sclerosis, there are very few therapeutic options for patients with progressive forms of multiple sclerosis. While immune mechanisms are key participants in the pathogenesis of relapsing remitting multiple sclerosis, the mechanisms underlying the development of progressive multiple sclerosis are less well understood. Putative mechanisms behind progressive multiple sclerosis have been put forth： insufficient energy production via mitochondrial dysfunction, activated microglia, iron accumulation, oxidative stress, activated astrocytes, Wallerian degeneration, apoptosis, etc. Furthermore, repair processes such as remyelination are incomplete. Experimental therapies that strive to improve metabolism within neurons and glia, e.g., oligodendrocytes, could act to counter inadequate energy supplies and/or support remyelination. Most experimental approaches have been examined as standalone interventions; however, it is apparent that the biochemical steps being targeted are part of larger pathways, which are further intertwined with other metabolic pathways. Thus, the potential benefits of a tested intervention, or of an established therapy, e.g., ocrelizumab, could be undermined by constraints on upstream and/or downstream steps. If correct, then this argues for a more comprehensive, multifaceted approach to therapy. Here we review experimental approaches to support neuronal and glial metabolism, and/or promote remyelination, which may have potential to lessen or delay progressive multiple sclerosis.

关键词： acetyl-coenzyme A carboxylase biotin estrogen iron Kynurenine pathway mitochondria thyroidhormone remyelination stem cells vitamin d

NAdPH oxidase-1 deficiency offers little protection in Salmonella typhimurium-induced typhlitis in mice

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World Journal of Gastroenterology 2016年第46期22卷 10158-10165页

作者： Fong-Fong Chu R steven Esworthy James H doroshow Binghui Shen department of Gastroenterology and Hepatology The First Affiliated Hospital and College of Clinical Medicine of Henan University of Science and Technology department of Cancer Genetics and Epigenetics Beckman Research Institute of City of Hope Center for Cancer Research and division of Cancer Treatment and diagnosis National Cancer Institute

AIM To test whether Nox1 plays a role in typhlitis induced by Salmonella enterica serovar Typhimurium(S. Tm) in a mouse *** Eight-week-old male wild-type(WT) and Nox1 knockout(KO) C57BL6/J(B6) mice were administered metronidazole water for 4 d to make them susceptible to S. Tm infection by the oral route. The mice were given plain water and administered with 4 different doses of S. Tm by oral gavage. The mice were followed for another 4 d. From the time of the metronidazole application, the mice were observed twice daily and weighed daily. The ileum, cecum and colon were removed for sampling at the fourth day post-inoculation. Portions of all three tissues were fixed for histology and placed in RNAlater for m RNA/c dNA preparation and quantitative real-time PCR. The contents of the cecum were recovered for estimation of S. Tm *** We found Nox1-knockout(Nox1-KO) mice were not more sensitive to S. Tm colonization and infection than WT B6 mice. This conclusion is based on the following observations:(1) S. Tm-infection induced similar weight loss in Nox1-KO mice compared to WT mice;(2) the same S. Tm CFU was recovered from the cecal content of Nox1-KO and WT mice regardless of the inoculation dose, except the lowest inoculation dose(2 × 106 CFU) for which the Nox1-KO had one-log lower CFU than WT mice;(3) there is no difference in cecal pathology between WT and Nox1-KO groups; and(4) there are no S. Tm infection-induced changes in gene expression levels(IL-1b, TNF-α, and duox2) between WT and Nox1-KO groups. The Alpi gene expression was more suppressed by S. Tm treatment in WT than the Nox1-KO cecum. CONCLUSION Nox1 does not protect mice from S. Tm colonization. Nox1-KO provides a very minor protective effect against S. Tm infection. Using NOX1-specific inhibitors for colitis therapy should not increase risks in bacterial infection.

关键词： Knockout mouse NAdPH Oxidase-1 Salmonella typhimurium Goblet cells Reactive oxygen species

Carbon isotope ratios of n-alkanoic acids: new organic proxies for paleo-productivity in Antarctic ponds

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Advances in Polar Science 2023年第4期34卷 304-317页

作者： CHEN Xin JIN Jing NIE Yaguang ZHANG Jifeng dONG Liang HUANG Xianyu steven dEMSLIE LIU Xiaodong Anhui Province Key Laboratory of Polar Environment and Global Change School of Earth and Space SciencesUniversity of Science and Technology of ChinaHefei 230026China School of Oceanography Shanghai Jiao Tong UniversityShanghai 200030China Key Laboratory for Polar Ecosystem and Climate Change of Ministry of Education School of OceanographyShanghai Jiao Tong UniversityShanghai 200030China Information Materials and Intelligent Sensing Laboratory of Anhui Province Institutes of Physical Science and Information TechnologyAnhui UniversityHefei 230601China Research Center for Ecology College of ScienceTibet UniversityLhasa 850000China Key Laboratory of Polar Science MNRPolar Research Institute of ChinaShanghai 200136China Hubei Key Laboratory of Critical Zone Evolution School of Geography and Information EngineeringChina University of GeosciencesWuhan 430078China department of Biology and Marine Biology University of North CarolinaWilmingtonNC 28403USA

Primary productivity in the Antarctic aquatic environment with simple ecosystems is sensitive to climate and environmental *** investigatedδ13C values for n-alkanoic acids derived from phototrophic organisms in a lacustrine sediment core(IIL3)to indicate primary productivity in ponds on Inexpressible Island in the western Ross Sea,***-chain n-alkanoic acids(C14–C18)were abundant in the IIL3 sediment *** carbon isotope ratios of short-chain n-alkanoic acids in the sediment samples and floating microbial mats were similar,indicating that the short-chain n-alkanoic acids in the IIL3 sediment profile predominantly originated from phototrophic ***δ13C values for the short-chain n-alkanoic acids varied widely through the sediment profile,and 13C-enrichment of n-alkanoic acids was most likely related to high productivity due to carbon-limited conditions caused by enhanced photosynthetic ***δ13C values for the n-alkanoic acids changed over the past 3200 years in similar ways to organic proxies for aquatic productivity(n-alkanoic acid and sterol sedimentary fluxes).C16 n-alkanoic acid was enriched in 13C in periods of high aquatic productivity~750–1650 and 3000–3200 a BP but depleted in 13C in periods of relatively low productivity~150–600 and 2500–3000 a *** results indicated that carbon isotope ratios of lipids from phototrophic organisms could be used as new proxies to reconstruct paleo-productivity in Antarctic lakes and ponds and therefore improve our understanding of past climate changes.

关键词： East Antarctica lipid biomarkers carbon isotopic ratios pond primary productivity climate change

A targetable pathway to eliminate TRA-1-60^(+)/TRA-1-81^(+)chemoresistant cancer cells

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Journal of Molecular Cell Biology 2023年第6期15卷 25-39页

作者： Lei Tan Xiaohua duan Pratyusha Mutyala Ting Zhou Sadaf Amin Tuo Zhang Brian Herbst Gokce Askan Tomer Itkin Zhaoying Xiang Fabrizio Michelassi Michael d.Lieberman Christine AIacobuzio-donahue steven dLeach Todd Evans Shuibing Chen department of Surgery Weill Cornell MedicineNew YorkNY 10065USA Center for Energy Metabolism and Reproduction Institute of Biomedicine and BiotechnologyShenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China Center for Genomic Health Weill Cornell MedicineNew YorkNY 10065USA The SKI Stem Cell Research Facility The Center for Stem Cell Biology and Developmental Biology ProgramMemorial Sloan Kettering Cancer CenterNew YorkNY 10065USA Genomic Resource Core Facility Weill Cornell Medical CollegeNew YorkNY 10065USA Rubenstein Center for Pancreatic Cancer Research Memorial Sloan Kettering Cancer CenterNew YorkNY 10065USA division of Regenerative Medicine Hartman Institute for Therapeutic Organ RegenerationAnsary Stem Cell InstituteDepartment of MedicineWeill Cornell MedicineNew YorkNY 10065USA dartmouth Cancer Center Darmouth CollegeHanoverNH 03755USA

Chemoresistance is a primary cause of treatment failure in pancreatic *** cell surface markers specifically expressed in chemoresistant cancer cells(CCCs)could facilitate targeted therapies to overcome *** performed an antibody-based screen and found that TRA-1-60 and TRA-1-81,two‘stemness’cell surface markers,are highly enriched in ***-more,TRA-1-60^(+)/TRA-1-81^(+)cells are chemoresistant compared to TRA-1-60^(-)/TRA-1-81^(-)*** profiling identified UGT1A10,shown to be both necessary and sufficient to maintain TRA-1-60/TRA-1-81 expression and *** a high-content chemical screen,we identified Cymarin,which downregulates UGT1A10,eliminates TRA-1-60/TRA-1-81 expression,and increases chemosensitivity both in vitro and in ***,TRA-1-60/TRA-1-81 expression is highly specific in primary cancer tissue and positively correlated with chemoresistance and short survival,which highlights their potentiality for targeted ***,we discovered a novel CCC surface marker regulated by a pathway that promotes chemoresistance,as well as a leading drug candidate to target this pathway.

关键词： pancreatic cancer TRA-1-60/TRA-1-81 chemoresistance UGT1A10 Cymarin

Burden of bone disease in chronic pancreatitis:A systematic review and meta-analysis

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World Journal of Gastroenterology 2023年第8期29卷 1374-1394页

作者： Ankit Chhoda Maria Jose Hernandez-Woodbine Nana Afua Akkya Addo Syed Alishan Nasir Alyssa Grimshaw Craig Gunderson Awais Ahmed steven d.Freedman Sunil G.Sheth department of Gastroenterology Beth Israel Deaconess Medical CenterBostonMA 02215United States department of Medicine Norwalk HospitalYale School of MedicineNorwalkCT 06850United States Cushing/Whitney Medical Library Yale UniversityNew HavenCT 06510United States General Internal Medicine Yale School of MedicineNew HavenCT 06510United States

BACKGROUNd Bone disease is an under-recognized cause of morbidity in chronic pancreatitis(CP).Over the past decade,publications of original studies on bone disease in CP has warranted synthesis of the evidence to ascertain the true burden of the *** To quantify the prevalence of osteopenia,osteoporosis,and fragility fractures in CP patients and investigate the associated clinical features and *** A systematic search identified studies investigating bone disease in CP patients from Cochrane Library,Embase,Google Scholar,Ovid Medline,PubMed,Scopus,and Web of Science,from inception until October *** outcomes included prevalence of osteopenia,osteoporosis,and fragility fractures,which were metaanalyzed using a random-effects model and underwent metaregression to delineate association with baseline clinical *** Twenty-one studies were included for systematic review and 18 studies were included for *** pooled prevalence of osteopenia and osteoporosis in CP patients was 41.2%(95%CI:35.2%-47.3%)and 20.9%(95%CI:14.9%-27.6%),*** pooled prevalence of fragility fractures described among CP was 5.9%(95%CI:3.9%-8.4%).Metaregression revealed significant association of pancreatic enzyme replacement therapy(PERT)use with prevalence of osteoporosis[coefficient:1.7(95%CI:0.6-2.8);Pd no associations with mean age,sex distribution,body mass index,alcohol or smoking exposure,diabetes with prevalence of osteopenia,osteoporosis or fragility *** of data on systemic inflammation,CP severity,and bone mineralization parameters precluded a formal *** This meta-analysis confirms significant bone disease in patients with *** than PERT use,we observed no patient or study-specific factor to be significantly associated with CP-related bone *** studies are needed to identify confounders,at-risk population,and to understand the mechanisms of CP-related bone disease an

关键词： Chronic pancreatitis Fractures Osteoporosis Osteopenia Bone disease

Transcriptional dynamics of the developing sweet cherry(Prunus avium L.)fruit:sequencing,annotation and expression profiling of exocarp-associated genes

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Horticulture Research 2014年第1期1卷 257-271页

作者： Merianne Alkio Uwe Jonas Myriam declercq steven Van Nocker Moritz Knoche Institute of Horticultural Production Systems Leibniz Universitat HannoverD-30419 HannoverGermany department of Horticulture Michigan State UniversityEast LansingMI 48824-1325USA.

The exocarp,or skin,of fleshy fruit is a specialized tissue that protects the fruit,attracts seed dispersing fruit eaters,and has large economical relevance for fruit *** of the exocarp involves regulated activities of many *** research analyzed global gene expression in the exocarp of developing sweet cherry(Prunus avium L.,‘Regina’),a fruit crop species with little public genomic resources.A catalog of transcript models(contigs)representing expressed genes was constructed from de novo assembled short complementary dNA(cdNA)sequences generated from developing fruit between flowering and maturity at 14 time *** levels in each sample were estimated for 34695 contigs from numbers of reads mapping to each *** were annotated functionally based on BLAST,gene ontology and InterProScan *** genes were detected using partitional clustering of expression *** results are discussed with emphasis on genes putatively involved in cuticle deposition,cell wall metabolism and sugar *** high temporal resolution of the expression patterns presented here reveals finely tuned developmental specialization of individual members of gene ***,the de novo assembled sweet cherry fruit transcriptome with 7760 full-length protein coding sequences and over 20000 other,annotated cdNA sequences together with their developmental expression patterns is expected to accelerate molecular research on this important tree fruit crop.

关键词： metabolism sweet sugar