简介：Calciumhexaluminate(CA6)wassynthesizedbymixinglight-weightcalciumcarbonateandAl2O3micropowder(calcinedα-Al2O3,activatedα-Al2O3orρ-Al2O3)accordingtothestoichimetricratioofCA6,andreactionsinteringat1200,1300,1400and1500℃for3h,respectively.Effectsofthethreealuminamicropowdersonthephasecomposition,microstructureandpropertiesofCA6wereinvestigated.Theresultsshowthat:(1)forthethreeAl2O3micropowders,thereactiontogenerateCA6inspecimensbasicallycompletesatabout1500℃;CA6generatedinallspecimensisplanar,butthearraymodesareslightlydifferent;(2)thespecimenspreparedfromcalcinedα-Al2O3orρ-Al2O3shrinkalmost,whilethespecimenspreparedfromactivatedα-Al2O3expand;(3)thecoldcrushingstrengthofthespecimenpreparedfromactivatedα-Al2O3isthehighest,reaching42.5MPawhenonlyCA6exists(afterfiringat1500℃);(4)thespecimenpreparedfromρ-Al2O3hasthelowestgenerationtemperatureofCA6andthehighestapparentporosity,reaching70.1%whenonlyCA6exists(afterfiringat1500℃);(5)thespecimenpreparedfromcalcinedα-Al2O3hasthebiggestbulkdensity.

简介：

简介：Propofolcaninhibittheinflammatoryresponseandreducethesecretionandharmfuleffectsofastrocyte-derivedproinflammatorycytokines.Inthisstudy,afterpropofolwasinjectedintotheinjuredsciaticnerveofmice,nuclearfactorkappaBexpressionintheL4-6segmentsofthespinalcordintheinjuredsidewasreduced,apoptosiswasdecreased,nervemyelindefectswerealleviated,andthenerveconductionblockwaslessened.Theexperimentalfindingsindicatethatpropofolinhibitstheinflammatoryandimmuneresponses,decreasestheexpressionofnuclearfactorkappaB,andreducesapoptosis.Theseeffectsofpropofolpromoteregenerationfollowingsciaticnerveinjury.

简介：

简介：Irradiationfromdiversesourcesisubiquitousandcloselyassociatedwithhumanactivities.Radiationtherapy(RT),animportantcomponentofmultipleradiationorigins,isacommontherapeuticmodalityforcancer.Moreimportantly,RTprovidessignificantcontributiontooncotherapybykillingtumorcells.However,duringthecourseoftherapy,irradiationofnormaltissuescanresultinawiderangeofsideeffects,includingself-limitedacutetoxicities,mildchronicsymptoms,orsevereorgandysfunction.Althoughnumerouspromisingradioprotectiveagentshaveemerged,onlyafewhavesuccessfullyenteredthemarketbecauseofvariouslimitations.Atpresent,thewidelyacceptedhypothesisforprotectionagainstradiation-causedinjuryinvolvestheWntcanonicalpathway.ActivatingtheWnt/β-cateninsignalingpathwaymayprotectthesalivarygland,oralmucosa,andgastrointestinalepitheliumfromradiationdamage.Theunderlyingmechanismsincludeinhibitingapoptosisandpreservingnormaltissuefunctions.However,aberrantWntsignalingunderliesawiderangeofpathologiesinhumans,anditsvariouscomponentscontributetocancer.Moreover,studieshavesuggestedthatWnt/β-cateninsignalingmayleadtoradioresistanceofcancerstemcell.ThesefactsmarkedlycomplicateanydefinitionoftheexactfunctionoftheWntpathway.

简介：

简介：

简介：

简介：

简介：Themutualradiationimpedanceignoredinconventionalarraydirectivityformulaisintroducedintothecalculationofarrayradiationsoundfield,andamodifiedarraydirectivityformulaconsideringthemutualradiationimpedanceisgainedaccordingtothesuperpositionprinciple.Resultsofcomputersimulationandexperimentsforauniformlineararrayandauniformplanararrayshowsuperiorperformanceonthepresentofthepracticaldirectivitypatternofthemodifiedformulainthispaperincomparisontotheconventionalone.

简介：

简介：Theprocessofhighpowerlaserinteractionwiththelargescalelengthcoronaplasmaproducedbytheleadingedgeofthelaserpulsehasbeeninvestigated.Earlyexperimentalresultsarere-analyzedandconclusionsdrawn.Inparticular,studiesofthecloseconnectionofunstablefilamentationinstabilitywith–mainly–two-plasmondecayand–partly–stimulatedRamanscattering,stimulatedBrillouinscattering,andresonanceabsorptionarecarriedoutinthispaper.Thepositiveandnegativeeffectsoffilamentationinstabilityarealsodiscussed.

简介：

简介：Sincerateefectofmaterialsplaysakeyroleinimpactengineering,themicroscopicmechanismofrateeffectisinvestigatedatmolecularlevelinthispaper.Theresultsshowthatrateefectonthestrengthofatomicsystemiscloselyrelatedtothecoupledevolutionofatomicmotionsandpotentiallandscapes.Accordingly,itbecomespossibletodevelopanewalgorithmofmolecularsimulation,whichcouldproperlyandefcientlydemonstratestrainrateefectunderawiderangeofloadingratesandunveilthemechanismsunderlyingthestrainrateefects.

简介：

简介：Bonedefectisoneofthemostcommondiseasesinclinic.Existingtherapeuticapproacheshaveencounteredmanyproblems,suchaslackofautogenousallogeneicboneandimmunologicalrejectiontoallogeneicimplant.Synthetichydroxyapatite（HA）providedsolutionsforbonerepair,sincetheHAisthemaininorganiccomponentofanimals＇bone.AlthoughHAhasgoodbiocompatibility,butonlythelimitedosteogeniccapability,whichisofsignificanceformodernbonerepairmaterials.Siisanessentialtraceelementinbonetissue,andithasbeendemonstratedtobeabletopromoteboneformation.Therefore,silicate-dopedhydroxyapatite（Si-HA）mayserveasapromisingmaterialforbonerepair,andpromoteboneregenerationintherepair.ThecurrentreviewdiscussesdevelopmentofSi-HA,focusingonitspreparationandcharacterization,invitroandinvivoevaluationsofthematerial,positiveeffectofSi-HAonpromotingboneformationinclinicalapplications,andmolecularmechanisminvestigationofsuchpromotiveeffect.

简介：

简介：

简介：Objective:Toobservetheeffectofstatinsonpreventingparoxysmalatrialfibrillation(PAF)afterpacemakerimlantationinpatientswithsicksinussyndrome.MaterialsandMethods:68patientswereselectedinwhichthepacemakershadbeenimplantedduetosicksinussyndrome,andwererandomlydividedintoastatintreatmentgroupandacontrolgroup.Afterthepacemakerimplantation,onlythepatientsintreatmentgroupweregiven20mgatorvastatinoncepernight,withotherconditionsbasicallysimilartothoseinthecontrolgroup.Atthe3rd,9th,15th,and21stmonthsaftertheimplantation,thepacemakerswereprogrammed,andthePAF-relatedinformationstoredinthepacemakerwererecalledandanalyzedstatistically.Results:Aftertheadministrationofstatinsfor9monthssincetheimlantation,theoccurrenceratesofPAFinthetreatmentgroupwasrelativelylowerthanthoseinthecontrolgroup.Afterfurtheradministrationofstatinsfor15months,boththeoccurrencerateofPAFandtheburdenofatrialfibrillationinthetreatmentgrouphadsignificantlydeclined.Aftercontinuousadministrationofstatinsfor21months,boththeoccurrencerateofPAFandtheburdenofatrialfibrillationinthetreatmentgroupweresignificantlylowerthanthoseinthecontrolgroup.Conclusion:Long-termadministrationofstatinscanreducetheriskofPAFaftertheimplantationofapacemakerinpatientswithsicksinussyndrome.

简介：