简介:AbstractImportance:The process of brain development in children with developmental delay is not well known. Amide proton transfer-weighted (APTw) imaging is a novel molecular magnetic resonance imaging (MRI) technique that can noninvasively detect cytosolic endogenous mobile proteins and peptides involved in the myelination process, and may be useful for providing insights into brain development.Objective:To assess the contribution of amide proton transfer-weighted (APTw) imaging and magnetization transfer (MT) imaging to the evaluation of children with developmental delay (DD).Methods:Fifty-one patients with DD were recruited to this study. The patients were divided into two groups according to the state of myelination assessed on conventional magnetic resonance imaging (MRI). Thirty patients (10 girls, 20 boys; age range: 1-8 months; median age: 4 months) in group A showed delayed myelination on MRI , while 21 patients (3 girls, 18 boys; age range: 12-36months; median age: 25months) in group B showed normal myelination on MRI. Fifty-one age- and sex-matched children with normal developmental quotient (DQ) and normal MRI appearance were recruited as normal controls. Three-slice APTw/MT axial imaging was performed at the level of the centrum semiovale, the basal ganglia and the pons. Quantitative data of the MT ratio (MTR) and APTw were analyzed for multiple brain regions. Independent-sample t-tests were used to compare differences in APTw and MTR signals between the two DD groups and normal controls. Analysis of Covariance was conducted to correct the statistical results. The level of statistical significance was set to P < 0.05.Results:For group A, the MTR values were lower in all regions (P = 0.004-0.033) compared with the normal controls, while the APTw values were higher in the pons, middle cerebellar peduncle, corpus callosum, frontal white matter, occipital white matter and centrum semiovale (P = 0.004-0.040 ). For Group B, the MTR values were slightly reduced, and the APTw values were slightly increased compared with the normal controls, but the differences were not statistically significant (P > 0.05).Interpretation:For DD patients showing signs of delayed myelination on MRI, MTR and APTw imaging can help to diagnose myelination delay by quantifying semi-solid macromolecules and cytosolic endogenous mobile proteins and peptides at a molecular level, providing a new method for comprehensive evaluation of DD. For DD patients with normal myelination on MRI, the clinical values of MTR and APTw imaging remain to be explored.
简介:AbstractThe developmental origins of health and disease theory states that environmental stresses during the early stages of life influence health and risk of developing non-communicable diseases throughout the lifespan of an individual. Developmental plasticity is thought to be a possible underlying mechanism. Here, I discuss a contrasting but complementary genetic hypothesis regarding the developmental origins of health and disease theory: crosstalk between the genomes of the parents and offspring is responsible for shaping and adapting responses to environmental stresses, regulating early growth and predisposition to non-communicable diseases. Genetic variants that are beneficial in terms of responses to early life stresses may have pleiotropic detrimental effects on health later in life, which may change the allele frequencies driven by selection on a population level. Genetic studies on the cohort of children born after assisted reproduction could provide insight regarding the genetic mechanisms of the developmental origins of health and disease theory.
简介:Masterdevelopmentalpathways,suchasNotch,Wnt,andHedgehog,aresignalingsystemsthatcontrolproliferation,celldeath,motility,migration,andstemness.Thesesystemsarenotonlycommonlyactivatedinmanysolidtumors,wheretheydriveorcontributetocancerinitiation,butalsoinprimaryandmetastatictumordevelopment.Thereactivationofdevelopmentalpathwaysincancerstromafavorsthedevelopmentofcancerstemcellsandallowstheirmaintenance,indicatingthesesignalingpathwaysasparticularlyattractivetargetsforefficientanticancertherapies,especiallyinadvancedprimarytumorsandmetastaticcancers.Metastasisistheworstfeatureofcancerdevelopment.Thisfeatureresultsfromacascadeofeventsemergingfromthehijackingofepithelial-mesenchymaltransition,angiogenesis,migration,andinvasionbytransformingcellsandisassociatedwithpoorsurvival,drugresistance,andtumorrelapse.Inthepresentreview,wesummarizeanddiscussexperimentaldatasuggestingpivotalrolesfordevelopmentalpathwaysincancerdevelopmentandmetastasis,consideringthetherapeuticpotential.EmergingtargetedantimetastatictherapiesbasedonNotch,Wnt,andHedgehogpathwaysarealsodiscussed.
简介:WeclonedcDNAsforXenopusaldolasesA,BandC.Thesethreealdolasegenesarelocalizedondifferentchromosomesasasinglecopygene.Intheadult,thealdolaseAgeneisexpressedextensivelyinmuscletissues,whereasthealdolaseBgeneisexpressedstronglyinkidney,liver,stomachandintestine,whilethealdolaseCgeneisexpressedinbrain,heartandovary.InoocytesaldolaseAandCmRNAs,butnotaldolaseBmRNA,areextensivelytranscribed.Thus,aldolaseAandCmRNAs,butnotBmRNA,occurabundantlyineggsasmaternalmRNAs,andstrongexpressionofaldolaseBmRNAisseenonlyafterthelateneurulastage.WeconcludethataldolaseAandCmRNAsaremajoraldolasemRNAsinearlystagesofXenopusembryogenesiswhichproceedsutilizingyolkastheonlyenergysource,aldolaseBmRNA,ontheotherhand,isexpressedonlylaterindevelopmentintissueswhicharerequiredfordietaryfructosemetabolism.WealsoisolatedtheXenopusaldolaseCgenomicgene(ca.12kb)andfoundthatitspromoter(ca.2kb)containsregionsnecessaryfortissue-specificexpressionandalsoaGCrichregionwhichisessentialforbasaltranscriptionalactivity.
简介:Theproblemofdelay-dependentrobuststabilityforsystemswithtitne-varyingdelayhasbeenconsidered.ByusingtheS-procedureandthePark'sinequalityintherecentissue,adelay-dependentrobuststabilitycriterionwhichislessconservativethanthepreviousresultshasbeenderivedfortime-delaysystemswithtime-varyingstructureduncertainties.Thesameideahasalsobeeneasilyextendedtothesystemswithnonlinearperturbations.Numericalexamplesillustratedtheeffectivenessandtheimprovementoftheproposedapproach.
简介:Somenewlinearmatrixinequality(LMI)representationsfordeley-independentanddelay-dependentstabilityconditionsareobtainedbyintroducingadditionalmatricesandeliminatingtheproductcouplingofthesystemmatricesandtheLyapunovmatrices.Theresultsimproveconservativenessofthegivenconditionsfortheanalysisandthedesignoftime-delaysystemswithpolytopic-typeuncertainty.
简介:Itisafactthatthefeedbackdelayactuallyarieseindigitalcontrolsystems.Itisnecessarytomodifythestructureofdigitalcontrolsystemsanddevelopnewcontrolalgorithms,whichisdoneinthispaper.Agreatnumberofdigitalcomputersimulationexperimentshaveshowntheobviousadvantageofthenewalgorithms.
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简介:ThispaperinvestigatestherobuststochasticstabilityandH∞analysisforstochasticsystemswithtime-varyingdelayandMarkovianjump.Byusingthefreeweightingmatrixtechnique,i.e.,He’stechnique,andastochasticLyapunov-Krasovskiifunctional,newdelay-dependentcriteriaintermsoflinearmatrixinequalitiesarederivedforthetherobuststochasticstabilityandtheH∞disturbanceattenuation.Threenumericalexamplesaregiven.Theresultsshowthattheproposedmethodisefficientandmuchlessconservativethantheexistingresultsintheliterature.更多还原
简介:植物高度的发展遗传基于NCII设计以二个环境条件从二组三线的indica混血儿米饭被分析,用添加剂主导的发展遗传模型和统计方法。结果证明米饭遗传型和环境条件能两个都影响植物高度,并且植物高度上的环境的效果与植物开发逐渐地减少了。添加剂和主导的效果两个都管理了植物高度的表演根本发展的阶段。然而,效果的度在米饭遗传型之中变化了。而且,在环境和遗传型之间的相互作用也影响了植物高度。基因效果不同至多发展的阶段。而且,添加剂效果的表示比主导的效果的更活跃。有环境的有条件的相互作用效果也在基因开发期间影响了植物高度,特别在早阶段。中间父母的杂种优势(HMP)与植物高度的发展阶段逐渐地增加了,并且而在更好的父母(HBP)上的杂种优势在遗传型之中显示出小差别,并且在以后的阶段保持稳定,在最近的阶段最大化,与积极数字价值。至多发展的阶段,有条件的HMP是确实重要的,当有条件的HBP是否定地重要的时。所有上面的结果建议HMP和HBP在所有发展时期和层次和方向有一些新表情是相当不同的。
简介:Primordialgermcells(PGCs),asprecursorsofmammaliangermlineage,havebeengainingmoreattentionasanewresourceofpluripotentstemcells,whichbringagreatpossibilitytostudydevelopmentaleventsofgermcellinvitroandatanimallevel.EG4cellsderivedfrom10.5dayspostcoitum(dpc)PGCsof129/svJstrainmousewereestablishedandmaintainedinanundifferentiatedstate.WithanattempttostudythedifferentiationcapabilityofEG4cellswithareporterprotein:greenfluorescenceprotein,andthepossibleapplicationofEG4cellsintheresearchofgermcelldevelopment,wehavegeneratedseveralEG4-GFPcelllinesexpressingenhancedgreenfluorescenceprotein(EGFP)andstillmaintainingtypicalcharacteristicsofpluripotentstemcells.Then,thedifferentiationofEG4-GFPcellsinvitroaswellastheirdevelopmentalfateinchimericembryoswhichwereproducedbyaggregatingEG4-GFPcellsto8-cellstageembryoswerestudied.TheresultsshowedthatEG4cellscarryinggreenfluorescencehaveapotentialuseintheresearchofgermcelldevelopmentandotherrelatedstudies.
简介:Diversityandcompositionoflepidopteranmicrobiotasarepoorlyinvestigated,especiallyacrossthedifferentdevelopmentalstages.Toimprovethisknowledge,wecharacterizethemicrobiotaamongdifferentdevelopmentalstagesoftheIndianmealmoth,Plodiainterpunctella,whichisconsideredoneofthemajorpestofcommoditiesworld-wide.Usingculture-independentapproachbasedonIllumina16SrRNAgenesequencingwecharacterizedthemicrobiotaoffourdevelopmentalstages:eggs,first-,andlast-instarlarvae,andadult.Atotalof1022bacterialOTUswereobtained,showingaquitediversifiedmicrobiotaassociatedtoalltheanalyzedstages.ThemicrobiotasassociatedwithP.interpunctellaresultedalmostconstantthroughoutthedevelopmentalstages,withapproximately77%ofbacterialOTUsbelongingtothephylumofProteobacteria.ThedominantbacterialgenusisrepresentedbyBurkholderia(?64%),followedbyPropionibacterium,Delftia,Pseudomonas,andStenotrophomonas.Acorebacterialcommunity,composedof139OTUs,wasdetectedinallthedevelopmentalstages,amongwhich112OTUswereassignedtothegenusBurkholderia.Aphylogeneticreconstruction,basedonthe16SrRNA,revealedthatourBurkholderiaOTUsclusteredwithBurkholderiacepaciacomplex,inthesamegroupofthoseisolatedfromthehemipteransGossypariaspuriaandAcanthococcusaceris.Thefunctionalprofiling,predictedonthebaseofthebacterial16SrRNA,indicatesdifferencesinthemetabolicpathwaysrelatedtometabolismofaminoacidsbetweenpreimaginalandadultstages.Wecanhypothesizethatbacteriamaysupporttheinsecthostduringpreimaginalstages.
简介:Inthispaper,adiscrete-timeanalysisofthethird-ordercharge-pumpbasedphase-lockedloops(CPLLs)ispresentedinthepresenceofloopdelay.Thez-domainanalysisoftheclosed-looptransferfunctionisderivedandcomparedwiththetraditionals-domainmethod.ThesimulationresultsunderSPECTREshowthat,duetothesamplingnatureofCPLL,thetraditionals-domainanalysisisunabletopredictitsjitterpeakingaccurately,especiallywhentheloopdelayistakenintoconsideration.Theimpactofloopdelayonthestabilityofthethird-orderCPLLsystemisfurtheranalyzedbasedontheproposedway.ThestabilitylimitofthewidebandwidthCPLLwithloopdelayiscalculated.Thecircuitsimulationresultsagreewellwithmathematicalanalysis.