简介：Theinvestigationwasperformedon4Mullets（27～49cmlongandweighing225～1500geach）ofbothsexesfromthewatersoffTianjin.Smallpiecesofthegillswereslicedandimmersionfixedinabuffermixtureof1.5%glutaraldehyde,1.5%paraformaldehydeand0.1mol/dm3phosphateforatleast24h.Afterfixationinphosphatebuffered1%O?O4at4℃for1h,thetissueswere

简介：ThisLetterproposesabrand-newfilamentdiametermeasurementmethodbasedonwhatiscalled'dualdiffraction,'inthatagratingisaddedbehindthefilamenttomakefulluseofitssubdivisionandamplificationcharacteristics.Highermeasurementaccuracyisachievedbythismethodcomparedwiththetraditionaldiffractionmethod.Toverifyitsaccuracy,threestandardfilamentswithnominalvaluesof100.2,120.1,and140.8μmaremeasuredbythedualdiffractionmethodandtraditionaldiffractionmethodunderthesameexperimentalconditions.Therelativemeasurementerrorsofthenewmethodarelessthan0.75%,anditsaveragerelativeerrorisreducedby56%comparedwiththetraditionaldiffractionmethod.

简介：Intermediatefilamentsareoneofthekeycomponentsofthecytoskeletonineukaryoticcells,andtheirmechanicalpropertiesarefoundtobeequallyimportantforphysiologicalfunctionanddisease.Whilethemechanicalpropertiesofsinglefulllengthfilamentshavebeenstudied,howthemechanicalpropertiesofcrosslinksaffectthemechanicalpropertyoftheintermediatefilamentnetworkisnotwellunderstood.Thispaperappliesamesoscopicmodeloftheintermediatenetworkwithvariedcrosslinkstrengthstoinvestigateitsfailuremechanismundertheextrememechanicalloading.Itfindsthatrelativelyweakercrosslinksleadtoamoreflawtolerantintermediatefilamentnetworkthatisalso23%strongerthantheonewithstrongcrosslinks.Thesefindingssuggestthatthemechanicalpropertiesofinterfacialcomponentsarecriticalforbioinspireddesignswhichprovideintriguingmechanicalproperties.

简介：Amodifiedtorsionpendulumapparatusisdevelopedformeasuringtheshearmodulusofsinglefilamentswithuniformmicro-sizeddiameter.Asinglefilamentfixedatbothendsandwitharing-shapedmassattachedatthemiddleisusedasaclamped-clampedtorsionpendulum.Theshearmodulusofsinglefilamentscanbeexpressedasafunctionoftheoscillationfrequencyofthetorsionpendulum.TheoscillationmotionismeasuredwithaCCDlaserdisplacementsensor,anditsfrequencyisdeterminedbytheFastFourierTransform(FFT)method.Theshearmoduliofthreetypesoffilaments:copperwires,tungstenwiresandcarbonfibersareaccuratelymeasuredwiththistechnique.Itisfoundthatthesizeeffectinshearmoduliofbothcopperwiresandtungstenwiresisminor.Finally,theerroranalysisofourmeasurementtechniqueispresentedindetail.

简介：Theestablishmentofadivertorconfigurationisataskforadivertortokamak.Toachievethisgoal,wehavetoidentifyplasmaboundaryatfirst.So,itisimportanttofindaquickapproachtocalculateplasmaboundaryandotherglobalparameters.Variousmethods

简介：Purpose：Theaimofthisstudywastoextendcurrenthalf-sarcomeremodelsbyinvolvingarecentlyfoundforce-mediatedactivationofthethickfilamentandanalyzetheeffectofthismechanosensingregulationonthelengthstabilityofhalf-sarcomeresarrangedinseries.Methods：Weincludedasuper-relaxedstateofmyosinmotorsanditsforce-dependentactivationinaconventionalcross-bridgemodel.Wesimulatedactivestretchesofasarcomereconsistingof2non-uniformhalf-sarcomeresonthedescendinglimboftheforce-lengthrelationship.Results：Themechanosensingmodelpredictsthat,inapassivesarcomereonthedescendinglimboftheforce-lengthrelationship,thelongerhalf-sarcomerehasahigherfractionofmyosinmotorsintheon-statethantheshorterhalf-sarcomere.Thedifferenceinthenumberofmyosinmotorsintheon-stateensuresthatuponcalcium-mediatedthinfilamentactivation,theforce-dependentthickfilamentactivationkeepsdifferencesinactiveforcewithin20%duringanactivestretch.Intheclassicalcross-bridgemodel,thecorrespondingdifferenceexceeds80%,leadingtogreatlengthinstabilities.Conclusion：Oursimulationssuggestthat,incontrasttotheclassicalcross-bridgemodel,themechanosensingregulationisabletostabilizeasystemofnon-uniformhalf-sarcomeresarrangedinseriesonthedescendinglimboftheforce-lengthrelationship.