简介:Thepitching-downflappingisanewtypeofbionicflapping,whichwasinventedbytheauthorbasedonpreviousstudiesontheaerodynamicmechanismsoffruitfly(pitching-up)flapping.ThemotivationofthisinventionistoimprovetheaerodynamiccharacteristicsofflappingMicroAirVehicles(MAVs).Inthispaperthepitching-downflappingisbrieflyintroduced.Themajorworksinclude:(1)Computingthepowerrequirementsofpitching-downflappinginthreemodes(advanced,symmetrical,delayed),whichwerecomparedwiththoseofpitching-upflapping;(2)Investigatingtheeffectsoftranslationalaccelerationtime,Δτ_t,androtationaltime,Δτ_r,attheendofastroke,andtheangleofattack,α,inthemiddleofastrokeontheaerodynamiccharacteristicsinsymmetricalmode;(3)Investigatingtheeffectofcamberonpitching-downflapping.Fromtheaboveworks,conclusionscanbedrawnthat:(1)Comparedwiththepitching-upflapping,thepitching-downflappingcangreatlyreducethetime-averagedpowerrequirements;(2)TheincreaseinΔτtandthedecreaseinΔτ_rcanincreaseboththeliftanddragcoefficients,butthetime-averagedratiooflifttodragchangesalittle.Andαhassignificanteffectontheaerodynamiccharacteristicsofthepitching-downflapping;(3)Thepositivecambercaneffectivelyincreasetheliftcoefficientandtheratiooflifttodrag.
简介:Inourpreviousstudies,DAZAP2geneexpressionwasdown-regulatedinuntreatedpatientsofmultiplemyeloma(MM).ForbetterstudyingthestructureandfunctionofDAZAP2,afull-lengthCdnawasisolatedfrommononuclearcellsofanormalhumanbonemarrow,sequencedanddepositedtoGenbank(AY430097).ThissequencehasanidenticalORF(openreadingframe)astheNM_014764fromhumantestisandtheD31767fromhumancelllineKG-1.PhylogeneticanalysisandstructurepredictionrevealthatDAZAP2homologuesarehighlyconservedthroughoutevolutionandshareapolyprolineregionandseveralpotentialSH2/SH3bindingsites.DAZAP2occursasasingle-copygenewithafour-exonorganization.WefurthernoticedthatthefunctionalDAZAP2geneislocatedonChromosome12anditspseudogenegeneisonChromosome2withelectroniclocationofhumanchromosomeinGenbank,thoughnogeneticabnormalitiesofMMhavebeenreportedonChromosome12.TheORFofhumanDAZAP2encodesa17-kDaprotein,whichishighlysimilartomousePrtb.TheDAZAP2proteinismainlylocalizedincytoplasmwithadiscretepatternofpunctuateddistribution.DAZAP2mayassociatewithcarcinogenesisofMMandparticipateinyet-to-beidentifiedsignalingpathwaystoregulateproliferationanddifferentiationofplasmacells.