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1.
DESENSITIZATION OF ACETYLCHOLINE ON THE INHIBITION EFFECTS OF BLOOD PRESSURE IN ANESTHETIZED CANINE 总被引:1,自引:0,他引:1
Desensitizationisaphenomenonthatthefirstreactiontowardsadrugdecreasedduringoraftercontinuouslyexposure[1] .Now ,theconceptioniswidelyusedtorepresentthephenomenonthatthereactionoftargettissuesorcellstowardshormone ,drugorneurotransmitterisreduced gradually[2 ] .Themechanismofdesensitizationisstillunclear .Itiswellknownthattheeffectsofheart,autonomicneuralsystem ,muscles ,arefadewhenexposuretoacetylcholine (ACh)foraperiodoftime[3] .Atpre sent,manystudiesfocusonisolatedtissuesorcells[1,5,6 ,7,8]… 相似文献
2.
Microporoussilicafilmswithspecialpropertiesareexpectedtobeusedinmanyfields,suchasopticalcoat ing[1 ] ,sensor,membrance[2 ] ,anddielectricfilm[3 ] .Itslowsoundspeedandacousticdelayorhigherratiosoundinsulatingmaybeusedasultrasounddetector[4] .Theexcellentfeaturesofinsulatingpropertyanditsnearper fectinterfaceonsiliconcouldplayakeyroleinsuccessofverylargescaleintegrated(VLSI)devices[5\〗,etc.Intheotheraspects,nanoporoussilicafilmsarebeingusedinseparationtechnology[6] ,molecularengineering,andbi… 相似文献
3.
Exceptforinaminorityofthecaseswithearlystageotitismedia (OM)orsequelae ,effusionisthemostcommoninflammatoryproductamongthevar iousOMtype .Itisnotclearwhetheruntreatedef fusionresultsinchronic ,irreversible pathologicchangesinthemiddleearcleftandmastoid[1 -4 ] .Chronicotitismedia (COM)ismainlyindicatedbytheformationofgranulationtissue .Granulationtis sueisthemostcommon [5,6] andsignificantrepresenta tivepathologictissueofCOM .Studiesonthefac tors promoting granulationtissueformation ,thepat… 相似文献
4.
11ntroductionThesliderfliesovertherotationgdiskinaverylowclearancetohousethetransducercom-pletingthereadandwriteoperationproperly.Itisdisastrousifaslidercrashesdowntherotatingdiskinworkingstate,whichmaycausediskdamagesduetotheseriousfrictionbetweenthesliderandthedisk-Recently,itisdiscoveredthattheslidercrashiscloselyrelatedwiththetapercontamination[l'2'3J.Kurokawa,TakahashiandShinohara[l]believethattheliquefactionofor-ganicgasesonthetapersectionpreventsaparti-clefrompassing,sotheparticlestays… 相似文献
5.
张江峰 《上海交通大学学报(英文版)》2002,7(1)
Introduction Let K be a field,K [X ]∶=K [x1,… ,xn]bethe polynomial ring in n variables.We know thatwhen K is a field with ch( K ) =0 ,then the Weylalgebra An( K) ,the ring of differential operatorsD( K[X]) ,and the derivative algebraΔ ( K [X])which is generated by{xi, i| i=1 ,… ,n}in End KK[X]are all isomorphic[1~ 3 ] .But if ch( K) =p>0 ,the three do not have that relation.In factΔ( K[X]) is only a quotientof An( K) [4] ;and Ref.[5 ]gives a comprehensive study to the rela… 相似文献
6.
Melatonin(Mel) ,anindoleamineprimarilyderivedfromthepinealgland ,issecretedduringthehoursofdarkness.Melactsasahormonalconduc tionof photoperiodinfluencedbytheseasonanddailyphysiologicalrhythms.Thefunctionofmelinhumansisobscure .However ,melhasattainedprominenceasatreatmentfordisturbedcircadianrhythmsandsleeppatterns ,hasenhancedthefunc tionofimmunitysystem[1] andhasinhibitedtumorgrowth[2 ] .Thepreviousstudieshaveindicatedthatmelcombinedwithotheranticancerdrugscanin creasetheefficiencyanddecre… 相似文献
7.
Leadtoxicityremainsapublicproblemintheworld ,especiallyinthedevelopingcountries.Chronicleadexposurecancauseimpairmentofcog nitivefunctionandsignificantdelaysinbehavioraldevelopment.However ,themechanismsunderly ingtheseimpairmentshavenotbeendefined .Long term potentiation (LTP)isthoughttobeavalidmodeloflearningandmemoryatthelevelofthesynapse[1] .Recently ,nitricoxidesynthase (NOS)hasbeenshowntobeanimportantfactorforforma tionandlastingofLTP[2 ,3 ] .Theremightbesomerelationsamonglead ,LTP… 相似文献
8.
Airborneinsectsbelongtovectorinsectsandmaybringonspreadingofepidemicdiseasesorleadtoallergicdisease[1] .Therelationshipbetweenair borneinsectandbronchialasthmahasbeenregardedbymoreandmoreallergistsrecently ;moreoversomepeopleconsiderthattheroleofairborneinsectsinetiologyofasthmaisnotinferiortothatofpollen ,fungusanddustmite[2 ,3] .Thisstudyistolearnaboutthevarietyofairborneallergenicin sects,toprovidenewevidenceforstudyingetiologyofasthmaandfindnewwaystopreventandcureasthma .MATERIALSANDM… 相似文献
9.
ENERGY LEVELS OF STRONG COUPLING MAGNETOPOLARON IN QUANTUM WIRE 总被引:4,自引:0,他引:4
IntroductionThe strong coupling polaron of bulk type hasbeen studied extensively[1,2 ] . Recently,people hasmuch interest of strong coupling polaron with re-duced dimensionality[3 ] ,especially the two- dimen-sional case[4,5] .T.Yildirim[6] studied the strongcoupling polaron with different dimensionality in aunifying model. S. Hameau et. al.[7] showed thatthe electrons and the longitudinal optical phononsare always in a strong coupling regime and form aneverlasting mixed electron- phonon mode… 相似文献
10.
Agingextentassessmentofgeneratorinsulationisofgreatsignificanceinplanninganeffectiveout ageandmaintenance .Inthelastdecade ,agingex tentassessmentoflargegeneratorinsulationwasasubjectresearchedintensively[1-4] .Anumberofpa pershavebeenpublishedonthetechniquesofinsu lationconditiondiagnosisandagingextentassess mentofgeneratorinsulation .Nearlyalleffortsforinsulationdiagnosisandagingassessmenthavereliedonelectricalmeasurementsandmostattentionhasbeenpaidtoanalysisofcharacteristicsofpartialdis cha… 相似文献
11.
INFLUENCE OF SURFACE MORPHOLOGY ON THE MICROHARDNESS OF ELECTROLESS Ni-B DEPOSIT REVEALED BY AFM OBSERVATION 总被引:1,自引:0,他引:1
Introduction Electroless Ni- B alloy has many advantagessuch as superior hardness,excellent wear- resis-tance and some special electrical and magneticproperties[1,2 ] . It can be prepared with eitherDimethylamineborane( DMAB) or sodium borohy-dride as reductant[3 ,4] .The deposits with lowerboron contentwhich are mainly applied to electron-ic industry[5] are prepared by DMAB.While sodi-um borohydride can bring about higher boron con-tent deposits which are chiefly used as wear- resis-… 相似文献
12.
Vascularendothelialcellsinhypoxiaandthelackofglucosecanproducealotofactiveoxygen ,whichresultsinthedamageofendothelialcells .Furthermore,dysfunctionofvascularendothelialcellsistheinitiativestepofatherosclerosisandmayleadtosomeofcardiovasculardiseases[1 ,2 ] .So ,theprotectionofendothelialcellsfromtheinjuryplaysanimportantroleinthepreventionandtreatmentofatherosclerosis,hypertension ,hyperc holesterolaemiaandsoon .Therefore,manyre searchershavebeenlookingforamedicinethatcanhelptomaintainthenorm… 相似文献
13.
14.
Studiesongermaniumcompoundsshowedthattheyhavemanybiologicaleffects ,suchasanti tu mor[1] ,improvingimmunity[2 ] ,reducingthecon centrationofbloodcholestrolandtrilycerides[3] ,in hibitingvirusreproduction ,butthesideeffectsoftoxicrestricttheirclinicaluses[4 ,5] .Therefore ,itisstillnecessarytodevelopothernewcompoundsoforganogermaniums.GeM 10 ,aneworganicgerma niumcompounds alkili metalcomplexcombinedwitheffectiveextractsofsomeChinesetraditionalherbs ,hasbeendemonstratedtobesaferandmorereliable.… 相似文献
15.
Graves diseaseisanorganspecificautoimmunediseasewhichismainlycausedbyhumoralresponse .Anti TSHreceptorantibodyisoneofthemostim portantfactorsthatcausethe physiopathologicchangeofthiskindofdisease .RecentstudiesofvariousFcreceptorgeneknockoutmice (FcRKOmice)haveprovidedstrongevidencethatFcrecep tors (FcR) playedcrucialrolesinmanyautoimmunediseases ,suchasauto antibody dependentexperi mentalhemolyticanemiaandthrombocy topenia[1- 3] .Inthepresentstudy ,wetriedtoex ploretheroleofFcγreceptoro… 相似文献
16.
Introduction Pantographic foldable structure works on theprinciple of a pantograph[1,2 ] . A structure of thistype may be referred to as“pantograph structure”,or simply“p- structure”. The basic unit for the p-structure is a componentso- called duplet[3 ] ,orpan-tograph unit[4] ,Scissor- Like Element ( SLE) [5] ,asshown in Fig.1 .A pantograph unitconsists of twocoplanar straightbars called uniplet,which are ca-pable of rotating about the intermediate pivot,re-ferred to as a scissor h… 相似文献
17.
Acuteliverfailure(ALF)isaseveresymptomcausedbykindsofreasons ,suchaschemicalandvirologicalones.Becauseofthelife threatingcom plicationsofacuteliverfailure ,75 %of patientswilldiewithinafewdaysofonset.TherewasnosatisfactorytreatmentforALFexceptlivertrans plantation .Althoughlivertransplantationissuccess ful,withasurvivalraterangingfrom 6 0 %to80 % [1] .Thereisashortageofavailabledonoror gans.Onlyalittleamountofpatientsreceivedlivertransplantation[2 ] .Sothereisagreatneedforanef fectiveliver… 相似文献
18.
The increased plasma methionine enkephalin(M- Enk) concentration in patients with liver dis-eases indicates an alteration of the immune func-tion in these patients[1] .Since the effects of opioidpeptide on modulation of immune system in humanbeing and animals under normal condition havebeen revealed,more interest has recently been fo-cused on conditions in stress as liver impairment[2 ] .An attractive trend has emerged in the pastdecadethat in stress some neuropeptides may be secretedand relea… 相似文献
19.
AngiotensinⅡ (AngⅡ ) playsanimportantroleintheregulationofbloodpressure[1 ] .Theac tionofAngⅡismediatedmainlybystimulationoftheangiotensintype 1(AT1 )receptorandinvolvesintheactivityofcatecholaminergicsystem .Im munostainingstudieshaveindicatedthattheAT1 re ceptorexistsonthecatecholaminergicneurons[2 ] .AdministrationofAngⅡintorat’sbrainincreasedtheconcentrationsofdopamine ,epinephrine ,andnorepinephrineinthebrain[3 ] .Althoughanatomicalandfunctionalevidencessupporttheinteractionbe twe… 相似文献
20.
Mifepristone (RU4 86 )hasbeenusedinclinicasaneffectiveemergencycontraception (EC)meth od .And ,areductionfrom 6 0 0mgto 10mgdidnotinfluenceefficacy[1] .However ,themechanismisnotclear .Inpractice ,unprotectedsexualintercoursecanoccuratanytimeinamenstrualcycle .AnidealECwouldbeonewhichcouldblockovulationandimplantation .Thus ,theeffectofEContherecep tivityoftheendometriumiscriticalforitseffec tiveness .Implantationofthehumanblastocystintheen dometriumisconsideredtobeinitiatedbyadia loguebet… 相似文献