首页
试卷库
试题库
当前位置：
X题卡
>
所有题目
>
题目详情
They didn't {{U}}realize{{/U}} how serious the problem was.
查看本题答案
包含此试题的试卷
卫生类《单选题》真题及答案
点击查看
你可能感兴趣的试题
HewasdrivinghomeonalonelyroaD.Thefactoryclosedhewa
Johnsohardonhisprojectthathedidntnoticehismomente
Theyagoodtimebecauseitrainedheavily. A.didnthave
阅读理解阅读下列短文从每小题所给的A.B.C.D.四个选项中选出一个能回答所提问题所给句子的最佳选项
Mybrotherdidnthavemuch ofAmericanhistorywhenhewasi
RecentlyIcameacrossashortstorysentinbyareaderDian
MrbrownquarredwithhiswifeHewasvery1＿withherforafew
8分Itisbelievedinsomewaysthatthedaughterisfather's
CouldyoutellmeyesterdayA.whybasn'thecome B.whyheha
Ifoildensityweregreaterthanwater’stheoilseparator_
did work
would work well
didnt work
wouldnt work
SaturdayOctober7thwasamarathonofsadtasksforAnnaPol
热门试题
更多
HeartAttack IntheUnitedStatesandespeciallyinbigcitiesandruralareastensofthousandsofpeoplewithheartsthatshouldbegood【51】tokeepthemalivedieeachyearforlackofadequatefirstaid.InNewYorkCityforexampleanewstudyhasshownthatonlyonepersonin100outsideofhospitals【52】aftertheheartsuddenlystopspumping.IncontrastinSeattlethesurvival【53】aftersuchheartattacksisoneinfive. Thedifferencecanbetraced【54】theeffectivenessofthechainofsurvivalDr.JosephP.Ornatosaid.Eachlinkinthe【55】mustbestrongenoughformanylivestobe【56】. Thechainbeginswithanimmediatetelephone【57】foremergencyhelpandthestartwithinfourminutesoftheprocessneededforrestartingthe【58】workingbyafamilymemberorbystander旁观者. Itcontinueswiththepromptarrival-------withineight【59】tenminutesofarescuerequippedwithaspecialinstrumentthatcanshocktheheartbacktoanormalrhythm.Anditendswiththeadministration给予实施ofadvanced先进emergencycarebynursestomaintaintheheart’’sabilitytosurviveuntilthedoctorsatthehospitalscantake【60】Whenoneormorelinksinthischainfailorfunctiontooslowlythe【61】ofavictimsurvivingheartattackfallsrapidly.Becauseofwidespreadweaknessesinthechainof【62】expertsinemergencyheartcareestimatethat20000to80000people【63】needlesslyofheartattackeachyearanumbercomparabletothe55000killedannuallyinautomobile【64】. OneexpertsaysSendinganemergencyvehicletoaheartattackvictim【65】thespecialequipmentislikehavingpolicemenwithgunsbutnobullets.Theymayputonagoodshowbuttheylacktheweaponneededtogetthejobdone.
DefectiveGenesandHumanHealth Eachofuscarriesabouthalfadozendefective有缺点的genes.Weremainblissfully快乐地unawareofthisfactunlessweoroneofourcloserelativesareamongstthemanymillionswhosufferfromageneticdisease.Aboutoneintenpeoplehasorwilldevelopatsomelaterstageaninherited遗传的geneticdisorderandapproximately2800specificconditionsareknowntobecausedbydefectsmutationsinjustoneofthepatient’’sgenes.Somesinglegenedisordersarequitecommon-—cystic胞状的fibrosis纤维化isfoundinoneoutofevery2500babiesbornintheWesternWorld—andintotaldiseasesthatcanbetracedtosinglegenedefectsaccountforabout5%ofalladmissionstochildren’’shospitals. Mostofusdonotsufferanyharmfuleffectsfromourdefectivegenesbecausewecarrytwocopiesofnearlyallgenesonederivedfromourmotherandtheotherfromourfather.Theonlyexceptionstothisrulearethegenesfoundonthemalesexchromosomes染色体MaleshaveoneXandoneYchromosometheformerfromthemotherandthelatterfromthefathersoeachcellhasonlyonecopyofthegenesonthesechromosomes.Inthemajorityofcasesonenormalgeneissufficienttoavoidallthesymptomsofdisease.Ifthepotentiallyharmfulgeneisrecessive后退的thenitsnormalcounterpart配对的willcarryoutallthetasksassignedtoboth.Onlyifweinheritfromourparentstwocopiesofthesamerecessivegenewilladiseasedevelop. Ontheotherhandifthegeneisdominant显性的italonecanproducethediseaseevenifitscounterpartisnormal.Clearlyonlythechildrenofaparentwiththediseasecanbeaffectedandthenaverageonlyhalfthechildrenwillbeaffected.Huntington’’schorea舞蹈病aseverediseaseofthenervoussystemwhichbecomesapparentonlyinadulthoodisanexampleofadominantgeneticdisease. FinallytherearetheXchromosome-linkedgeneticdiseases.Asmaleshaveonlyonecopyofthegenesfromthischromosometherearenoothersavailabletofulfillthedefectivegene’’sfunction.ExamplesofsuchdiseasesareDuchennemusculardystrophy营养不良andperhapsmostwellknownofallhemophilia血友病. QueenVictoriawasacarrierofthedefectivegeneresponsibleforhemophiliaandthroughheritwastransmittedtotheroyalfamiliesofRussiaSpainandPrussia.MinorcutsandbruiseswhichwoulddolittleharmtomostpeoplecanprovefataltohemophiliacswholacktheproteinsFactorsVIIIandIV凝血因子VIII和IVinvolvedintheclotting血凝结ofbloodwhicharecodedforbythedefectivegenes.Sadlybeforetheseproteinsweremadeavailablethroughgeneticengineeringhemophiliacsweretreatedwithproteinsisolatedfromhumanblood.Someofthisbloodwascontaminated污损withtheAIDSvirusandhasresultedintragic悲惨的consequencesformanyhemophiliacs.Useofgeneticallyengineeredproteinsintherapeuticapplicationsratherthanbloodproductswillavoidtheseproblemsinthefuture. Notalldefectivegenesnecessarilyproducedetrimental有害的effectssincetheenvironmentinwhichthegeneoperatesisalsoofimportance.Aclassicexampleofageneticdiseasehavingabeneficialeffectonsurvivalisillustratedbytherelationshipbetweensickle-cell镶形血球anemia贫血症andmalaria疟病.Onlyindividualshavingtwocopiesofthesickle-cellgeneandonenormalgeneareunaffectedandmoreimportantlyareabletoresistinfection传染bymalarialparasites寄生虫.Theclearadvantageinthiscaseofhavingonedefectivegeneexplainswhythisgeneiscommoninpopulationsinthoseareasoftheworldwheremalariaisendemic特有的. WhichofthefollowingstatementsongenesanddiseasesisNOTTRUE?
{{*HTML*}} ??1.??AIDSisthefinal life-threateningstageofinfectionwithhumanimmuno-deficiencyvirusHIV. AIDSstandsforacquiredimmuno-deficiencysyndrome.Thenamereferstothefact thatHIVseverelydamagesthepatient’sdisease-fightingimmunesystem.Casesof AIDSwerefirstidentifiedin1981intheUnitedStatesbutresearchershave tracedcasestoasearlyas1969.MillionsofAIDScaseshavebeendiagnosed worldwide.??2.??AIDSiscausedbytwovirusesthat belongtoagroupcalledretroviruses.ThefirstAIDSviruswasisolatedby researchersinFrancein1983andresearchersintheUnitedStatesin1984.This virusbecameknownasHIV-1.in1985scientistsinFranceidentifiedanother closelyrelatedvirusthatalsoproducesAIDS.ThisvirusnamedHIV-2occurs mainlyinAfrica.HIV-1occursthroughouttheworld.??3.? ?PeopleinfectedwithHIVeventuallydevelopsymptomsthatalsomaybe causedbyotherlessseriousconditions.WithHIVinfectionhoweverthese symptomsareprolongedandoftenmoresevere.Theyincludeenlargedlymph glandstirednessfeverlossofappetiteandweightdiarrheayeast infectionsofthemouthandvaginaandnightsweats.??4.? ?AnHIV-infectedpersonmaydevelopAIDSfrom2to15ormoreyearsafter becominginfected.InchildrenbornwithHIVinfectionthisintervalisusually shorter.AfewpeoplewhohavebeeninfectedwithHIVformorethan15years havenotdevelopedanysymptomsorsufferonlyminorsymptoms.Aninfected personcantransmitthevirustoanotherpersonwhetherornotsymptomsare present.InfectionwithHIVappearstobelifelonginallwhobecomeinfected. ??5.??Researchershaveidentifiedthreewaysin whichHIVistransmitted:sexualintercoursedirectcontactwithinfected bloodandtransmissionfromaninfectedwomantoherfetusorbaby.Themost commonwayofbecominginfectedisthroughintimatesexualcontactwithan HIV-infectedperson.IntheUnitedStatessexualtransmissionofHIVhas occurredmainlyamonghomosexualmenbutitisbecomingmorefrequentamong heterosexualmenandwomen.??6.??Peoplewhoinject drugsintotheirbodiescanbeexposedtoinfectedbloodbysharinghypodermic needlessyringesorequipmentusedtopreparedrugsforinjection.Health-care workerscanbecomeinfectedwithHIVbycomingintodirectcontactwith ?infectedblood.Thismayoccurthroughinjurywithaneedleorothersharp instrumentusedintreatinganHIV-infectedpatient.Afewpatientshavebecome infectedwhilereceivingtreatmentfromanHIV-infecteddentist.? ?7.??AninfectedpregnantwomancantransmittheAIDSvirusto herfetusevenifshehasnosymptoms.Transmissionmayalsooccurfroman HIV-infectedmothertoherbabythroughbreast-feeding.??8. ??StudiesindicatethatHIVisnottransmittedthroughairfoodor waterorbyinsects.NoknowncasesofAIDShaveresultedfromsharingeating utensilsbathroomslockerroomslivingspaceor classrooms.Paragraph3______.
{{*HTML*}} ??Antibioticresistancedoesn’tjust makepathogens病原体difficulttotreatItalsomakesthemhardertotrack Traditionallyepidemiologists流行病专家followingthepathsofdisease-causing microbeshaveidentifiedtheirsuspectsbyfeaturesofbacterial polysaccharide多糖coatssusceptibilitytodifferentantibioticsorother schemesButthesetrackingtechniquesarelosingtheirrelevance相关性实用性 saysAlexanderTomaszamicrobiologistatRockefellerUniversityinNewYork City.Withtheincreaseindrugresistanceavarietyofresistantmicrobescan nowwearthesamecoatorberesistanttothesamedrugsmakingitharderand hardertokeeptabsonindividualstrains菌株.?? Epidemiologiststhereforeareincreasinglyturningtomoreprecisemolecular typingtechniquessuchasDNAfingerprintingtodistinguishresistantstrains. ??DNAtypingtoolsareofcoursenotnew.Indeedsome DNA-basedmethodssuchascomparingplasmids质体smallringsofDNAoutside thechromosomes〈染色体〉havebeenusedbyepidemiologiststotrackinfections sincethe1970s.butsinceplasmidDNAistransferredeasilyandoftenbetween differentstrainsthattechniquetoohasitslimitations.?? ?Morerecenttechniquesuserestrictionenzymestocutapartentire bacterialchromosomesintostrain-specificfragmentpatternsAnothermethod usesspecificradiolabeled放射标汇的DNAprobesinatechniqueknownasSouthern hybridization杂交totestforthepresenceofaparticulardrug-resistancegene inabacterialstrain.Suchtoolsgiveepidemiologistsunprecedentedresolving powerforidentifyingreservoirsandtransitionroutesofgenesandpathogens saysTomasz.Thathashelpedresearcherstrackanumberofdrug-resistant clonesastheytravelvastdistances.???Suchtracking methodsalsohelpuslearnaboutthemechanismofresistancesays CDC疾病控制和预防中心epidemiologistRobertBreiman.Resistancegrowsheexplains eitherasoneresistantorganismspreadsfromonelocationtothenext—asinthe BrazilianMRSA耐甲氧苯青素金黄色葡萄球菌—orasdifferentstrainsandevenspeciesof microbessharethegenesresponsiblefordrugresistanceasaseriesofstudies ofvancomycin万古霉素resistancerecentlydemonstrated.??That knowledgealsohelpspublichealthofficialscombatthespread.Ifresistance spreadshorizontally’asamicrobeincreasesitsrangeBreimansaysit’s importanttofocuspreventioneffortsonminimizingperson-to-personspreadin hospitalsandday-carecenters.Ifhoweverresistancegenesarejumping betweenorganismsthatsuggeststhatoverlyaggressiveantibiotictreatmentis encouragingnonresistantbugstoacquirenewgenes.Insuchcasesthefocus needstobeoncontrollinganti-microbialusesaysBreiman.Thehoped-for result:fewerinfectionstotrack.Usingspecificradio-labeledDNAprobesprovidesepidemiologistsunprecedentedresolvingpowerforidentifyingreservoirandtransitionroutesofgenesandpathogens.
{{*HTML*}} ??Antibioticresistancedoesn’tjust makepathogens病原体difficulttotreatItalsomakesthemhardertotrack Traditionallyepidemiologists流行病专家followingthepathsofdisease-causing microbeshaveidentifiedtheirsuspectsbyfeaturesofbacterial polysaccharide多糖coatssusceptibilitytodifferentantibioticsorother schemesButthesetrackingtechniquesarelosingtheirrelevance相关性实用性 saysAlexanderTomaszamicrobiologistatRockefellerUniversityinNewYork City.Withtheincreaseindrugresistanceavarietyofresistantmicrobescan nowwearthesamecoatorberesistanttothesamedrugsmakingitharderand hardertokeeptabsonindividualstrains菌株.?? Epidemiologiststhereforeareincreasinglyturningtomoreprecisemolecular typingtechniquessuchasDNAfingerprintingtodistinguishresistantstrains. ??DNAtypingtoolsareofcoursenotnew.Indeedsome DNA-basedmethodssuchascomparingplasmids质体smallringsofDNAoutside thechromosomes〈染色体〉havebeenusedbyepidemiologiststotrackinfections sincethe1970s.butsinceplasmidDNAistransferredeasilyandoftenbetween differentstrainsthattechniquetoohasitslimitations.?? ?Morerecenttechniquesuserestrictionenzymestocutapartentire bacterialchromosomesintostrain-specificfragmentpatternsAnothermethod usesspecificradiolabeled放射标汇的DNAprobesinatechniqueknownasSouthern hybridization杂交totestforthepresenceofaparticulardrug-resistancegene inabacterialstrain.Suchtoolsgiveepidemiologistsunprecedentedresolving powerforidentifyingreservoirsandtransitionroutesofgenesandpathogens saysTomasz.Thathashelpedresearcherstrackanumberofdrug-resistant clonesastheytravelvastdistances.???Suchtracking methodsalsohelpuslearnaboutthemechanismofresistancesays CDC疾病控制和预防中心epidemiologistRobertBreiman.Resistancegrowsheexplains eitherasoneresistantorganismspreadsfromonelocationtothenext—asinthe BrazilianMRSA耐甲氧苯青素金黄色葡萄球菌—orasdifferentstrainsandevenspeciesof microbessharethegenesresponsiblefordrugresistanceasaseriesofstudies ofvancomycin万古霉素resistancerecentlydemonstrated.??That knowledgealsohelpspublichealthofficialscombatthespread.Ifresistance spreadshorizontally’asamicrobeincreasesitsrangeBreimansaysit’s importanttofocuspreventioneffortsonminimizingperson-to-personspreadin hospitalsandday-carecenters.Ifhoweverresistancegenesarejumping betweenorganismsthatsuggeststhatoverlyaggressiveantibiotictreatmentis encouragingnonresistantbugstoacquirenewgenes.Insuchcasesthefocus needstobeoncontrollinganti-microbialusesaysBreiman.Thehoped-for result:fewerinfectionstotrack.Thisenzymemanufacturesprostaglandinssubstancesthatcausepainandinflammation.
Ourinterestswerequite{{U}}distinct{{/U}}fromtheseofthemanagers.
CigarsInstead? Smokingoneortwocigarsadaydoublestheriskofcancersoftheliptonguemouthandthroataccordingtoagovernmentstudy. DailycigarsalsoincreasetheriskoflungcancerandcanceroftheesophagusandincreasetheriskofcancerofthelarynxvoiceboxsixfoldsayresearchersattheNationalCancerInstituteinBethesdaMaryland. Inadditionthereportrevealedthatsmokingthreeorfourcigarsadayincreasedtheriskoforalcancerto8.5timestheriskfornonsmokersandtheriskofesophagealcancerbyfourtimestheriskofnonsmokers. ThehealtheffectsofsmokingcigarsisoneofeightsectionsofthearticleCigars:HealthEffectsandTrends.Theresearchersreportthatcomparedwithacigarettealargecigaremitsupto90timesasmuchcarcinogenictobacco-specificnitrosamines ThisarticleprovidesclearandinvaluableinformationaboutthedisturbingincreaseincigaruseandthesignificantpublichealthconsequencesforthecountrysaidDr.RichardKlausnerdirectoroftheNationalCancerInstituteinastatement. Thedataareclear-theharmfulsubstancesandcarcinogensincigarsmokelikecigarettesareassociatedwiththeincreasedrisksofseveralkindsofcancersaswellasheartandlungdiseasesheadded.Inotherwordscigarsarenotsafealternativestocigarettesandmaybeaddictive. Tothoseindividualswhomaybethinkingaboutsmokingcigarsouradvicesis—don’’t.TothosecurrentlysmokingcigarsquittingistheonlywaytoeliminatecompletelythecancerheartandlungdiseaseriskswarnedKlausner. AccordingtoaNationalCancerInstitutepressreleasetherehaven’’tbeenanystudiesonthehealtheffectsonnonsmokersatcigarsocialeventsbut...asignificantbodyofevidenceclearlydemonstratesanincreasedlungcancerriskfromsecondhandsmoke. Whatisthedoctors’advicetothosecigar-smokers?
Manyrichmenonlydriveold{{U}}unpretentious{{/U}}cars.
HeartAttack IntheUnitedStatesandespeciallyinbigcitiesandruralareastensofthousandsofpeoplewithheartsthatshouldbegood【51】tokeepthemalivedieeachyearforlackofadequatefirstaid.InNewYorkCityforexampleanewstudyhasshownthatonlyonepersonin100outsideofhospitals【52】aftertheheartsuddenlystopspumping.IncontrastinSeattlethesurvival【53】aftersuchheartattacksisoneinfive. Thedifferencecanbetraced【54】theeffectivenessofthechainofsurvivalDr.JosephP.Ornatosaid.Eachlinkinthe【55】mustbestrongenoughformanylivestobe【56】. Thechainbeginswithanimmediatetelephone【57】foremergencyhelpandthestartwithinfourminutesoftheprocessneededforrestartingthe【58】workingbyafamilymemberorbystander旁观者. Itcontinueswiththepromptarrival-------withineight【59】tenminutesofarescuerequippedwithaspecialinstrumentthatcanshocktheheartbacktoanormalrhythm.Anditendswiththeadministration给予实施ofadvanced先进emergencycarebynursestomaintaintheheart’’sabilitytosurviveuntilthedoctorsatthehospitalscantake【60】Whenoneormorelinksinthischainfailorfunctiontooslowlythe【61】ofavictimsurvivingheartattackfallsrapidly.Becauseofwidespreadweaknessesinthechainof【62】expertsinemergencyheartcareestimatethat20000to80000people【63】needlesslyofheartattackeachyearanumbercomparabletothe55000killedannuallyinautomobile【64】. OneexpertsaysSendinganemergencyvehicletoaheartattackvictim【65】thespecialequipmentislikehavingpolicemenwithgunsbutnobullets.Theymayputonagoodshowbuttheylacktheweaponneededtogetthejobdone.
{{U}}Merge{{/U}}thefollowingtwoshortsentencesintoonenewsentence.
CigarsInstead? Smokingoneortwocigarsadaydoublestheriskofcancersoftheliptonguemouthandthroataccordingtoagovernmentstudy. DailycigarsalsoincreasetheriskoflungcancerandcanceroftheesophagusandincreasetheriskofcancerofthelarynxvoiceboxsixfoldsayresearchersattheNationalCancerInstituteinBethesdaMaryland. Inadditionthereportrevealedthatsmokingthreeorfourcigarsadayincreasedtheriskoforalcancerto8.5timestheriskfornonsmokersandtheriskofesophagealcancerbyfourtimestheriskofnonsmokers. ThehealtheffectsofsmokingcigarsisoneofeightsectionsofthearticleCigars:HealthEffectsandTrends.Theresearchersreportthatcomparedwithacigarettealargecigaremitsupto90timesasmuchcarcinogenictobacco-specificnitrosamines ThisarticleprovidesclearandinvaluableinformationaboutthedisturbingincreaseincigaruseandthesignificantpublichealthconsequencesforthecountrysaidDr.RichardKlausnerdirectoroftheNationalCancerInstituteinastatement. Thedataareclear-theharmfulsubstancesandcarcinogensincigarsmokelikecigarettesareassociatedwiththeincreasedrisksofseveralkindsofcancersaswellasheartandlungdiseasesheadded.Inotherwordscigarsarenotsafealternativestocigarettesandmaybeaddictive. Tothoseindividualswhomaybethinkingaboutsmokingcigarsouradvicesis—don’’t.TothosecurrentlysmokingcigarsquittingistheonlywaytoeliminatecompletelythecancerheartandlungdiseaseriskswarnedKlausner. AccordingtoaNationalCancerInstitutepressreleasetherehaven’’tbeenanystudiesonthehealtheffectsonnonsmokersatcigarsocialeventsbut...asignificantbodyofevidenceclearlydemonstratesanincreasedlungcancerriskfromsecondhandsmoke. Inthepassagehowmanycancersarementionedinrelationtosmokingcigarsdaily?
HeartAttack IntheUnitedStatesandespeciallyinbigcitiesandruralareastensofthousandsofpeoplewithheartsthatshouldbegood【51】tokeepthemalivedieeachyearforlackofadequatefirstaid.InNewYorkCityforexampleanewstudyhasshownthatonlyonepersonin100outsideofhospitals【52】aftertheheartsuddenlystopspumping.IncontrastinSeattlethesurvival【53】aftersuchheartattacksisoneinfive. Thedifferencecanbetraced【54】theeffectivenessofthechainofsurvivalDr.JosephP.Ornatosaid.Eachlinkinthe【55】mustbestrongenoughformanylivestobe【56】. Thechainbeginswithanimmediatetelephone【57】foremergencyhelpandthestartwithinfourminutesoftheprocessneededforrestartingthe【58】workingbyafamilymemberorbystander旁观者. Itcontinueswiththepromptarrival-------withineight【59】tenminutesofarescuerequippedwithaspecialinstrumentthatcanshocktheheartbacktoanormalrhythm.Anditendswiththeadministration给予实施ofadvanced先进emergencycarebynursestomaintaintheheart’’sabilitytosurviveuntilthedoctorsatthehospitalscantake【60】Whenoneormorelinksinthischainfailorfunctiontooslowlythe【61】ofavictimsurvivingheartattackfallsrapidly.Becauseofwidespreadweaknessesinthechainof【62】expertsinemergencyheartcareestimatethat20000to80000people【63】needlesslyofheartattackeachyearanumbercomparabletothe55000killedannuallyinautomobile【64】. OneexpertsaysSendinganemergencyvehicletoaheartattackvictim【65】thespecialequipmentislikehavingpolicemenwithgunsbutnobullets.Theymayputonagoodshowbuttheylacktheweaponneededtogetthejobdone.
HeartAttack IntheUnitedStatesandespeciallyinbigcitiesandruralareastensofthousandsofpeoplewithheartsthatshouldbegood【51】tokeepthemalivedieeachyearforlackofadequatefirstaid.InNewYorkCityforexampleanewstudyhasshownthatonlyonepersonin100outsideofhospitals【52】aftertheheartsuddenlystopspumping.IncontrastinSeattlethesurvival【53】aftersuchheartattacksisoneinfive. Thedifferencecanbetraced【54】theeffectivenessofthechainofsurvivalDr.JosephP.Ornatosaid.Eachlinkinthe【55】mustbestrongenoughformanylivestobe【56】. Thechainbeginswithanimmediatetelephone【57】foremergencyhelpandthestartwithinfourminutesoftheprocessneededforrestartingthe【58】workingbyafamilymemberorbystander旁观者. Itcontinueswiththepromptarrival-------withineight【59】tenminutesofarescuerequippedwithaspecialinstrumentthatcanshocktheheartbacktoanormalrhythm.Anditendswiththeadministration给予实施ofadvanced先进emergencycarebynursestomaintaintheheart’’sabilitytosurviveuntilthedoctorsatthehospitalscantake【60】Whenoneormorelinksinthischainfailorfunctiontooslowlythe【61】ofavictimsurvivingheartattackfallsrapidly.Becauseofwidespreadweaknessesinthechainof【62】expertsinemergencyheartcareestimatethat20000to80000people【63】needlesslyofheartattackeachyearanumbercomparabletothe55000killedannuallyinautomobile【64】. OneexpertsaysSendinganemergencyvehicletoaheartattackvictim【65】thespecialequipmentislikehavingpolicemenwithgunsbutnobullets.Theymayputonagoodshowbuttheylacktheweaponneededtogetthejobdone.
{{*HTML*}} ??Antibioticresistancedoesn’tjust makepathogens病原体difficulttotreatItalsomakesthemhardertotrack Traditionallyepidemiologists流行病专家followingthepathsofdisease-causing microbeshaveidentifiedtheirsuspectsbyfeaturesofbacterial polysaccharide多糖coatssusceptibilitytodifferentantibioticsorother schemesButthesetrackingtechniquesarelosingtheirrelevance相关性实用性 saysAlexanderTomaszamicrobiologistatRockefellerUniversityinNewYork City.Withtheincreaseindrugresistanceavarietyofresistantmicrobescan nowwearthesamecoatorberesistanttothesamedrugsmakingitharderand hardertokeeptabsonindividualstrains菌株.?? Epidemiologiststhereforeareincreasinglyturningtomoreprecisemolecular typingtechniquessuchasDNAfingerprintingtodistinguishresistantstrains. ??DNAtypingtoolsareofcoursenotnew.Indeedsome DNA-basedmethodssuchascomparingplasmids质体smallringsofDNAoutside thechromosomes〈染色体〉havebeenusedbyepidemiologiststotrackinfections sincethe1970s.butsinceplasmidDNAistransferredeasilyandoftenbetween differentstrainsthattechniquetoohasitslimitations.?? ?Morerecenttechniquesuserestrictionenzymestocutapartentire bacterialchromosomesintostrain-specificfragmentpatternsAnothermethod usesspecificradiolabeled放射标汇的DNAprobesinatechniqueknownasSouthern hybridization杂交totestforthepresenceofaparticulardrug-resistancegene inabacterialstrain.Suchtoolsgiveepidemiologistsunprecedentedresolving powerforidentifyingreservoirsandtransitionroutesofgenesandpathogens saysTomasz.Thathashelpedresearcherstrackanumberofdrug-resistant clonesastheytravelvastdistances.???Suchtracking methodsalsohelpuslearnaboutthemechanismofresistancesays CDC疾病控制和预防中心epidemiologistRobertBreiman.Resistancegrowsheexplains eitherasoneresistantorganismspreadsfromonelocationtothenext—asinthe BrazilianMRSA耐甲氧苯青素金黄色葡萄球菌—orasdifferentstrainsandevenspeciesof microbessharethegenesresponsiblefordrugresistanceasaseriesofstudies ofvancomycin万古霉素resistancerecentlydemonstrated.??That knowledgealsohelpspublichealthofficialscombatthespread.Ifresistance spreadshorizontally’asamicrobeincreasesitsrangeBreimansaysit’s importanttofocuspreventioneffortsonminimizingperson-to-personspreadin hospitalsandday-carecenters.Ifhoweverresistancegenesarejumping betweenorganismsthatsuggeststhatoverlyaggressiveantibiotictreatmentis encouragingnonresistantbugstoacquirenewgenes.Insuchcasesthefocus needstobeoncontrollinganti-microbialusesaysBreiman.Thehoped-for result:fewerinfectionstotrack.AccordingtoAlexanderTomaszthetraditionaltrackingtechniquesareturningouttobeefficient.
HeartAttack IntheUnitedStatesandespeciallyinbigcitiesandruralareastensofthousandsofpeoplewithheartsthatshouldbegood【51】tokeepthemalivedieeachyearforlackofadequatefirstaid.InNewYorkCityforexampleanewstudyhasshownthatonlyonepersonin100outsideofhospitals【52】aftertheheartsuddenlystopspumping.IncontrastinSeattlethesurvival【53】aftersuchheartattacksisoneinfive. Thedifferencecanbetraced【54】theeffectivenessofthechainofsurvivalDr.JosephP.Ornatosaid.Eachlinkinthe【55】mustbestrongenoughformanylivestobe【56】. Thechainbeginswithanimmediatetelephone【57】foremergencyhelpandthestartwithinfourminutesoftheprocessneededforrestartingthe【58】workingbyafamilymemberorbystander旁观者. Itcontinueswiththepromptarrival-------withineight【59】tenminutesofarescuerequippedwithaspecialinstrumentthatcanshocktheheartbacktoanormalrhythm.Anditendswiththeadministration给予实施ofadvanced先进emergencycarebynursestomaintaintheheart’’sabilitytosurviveuntilthedoctorsatthehospitalscantake【60】Whenoneormorelinksinthischainfailorfunctiontooslowlythe【61】ofavictimsurvivingheartattackfallsrapidly.Becauseofwidespreadweaknessesinthechainof【62】expertsinemergencyheartcareestimatethat20000to80000people【63】needlesslyofheartattackeachyearanumbercomparabletothe55000killedannuallyinautomobile【64】. OneexpertsaysSendinganemergencyvehicletoaheartattackvictim【65】thespecialequipmentislikehavingpolicemenwithgunsbutnobullets.Theymayputonagoodshowbuttheylacktheweaponneededtogetthejobdone.
TheAttitudeForComputers AsDr.SamuelJohnsonsaidinadifferenteraaboutladiespreachingthesurprisingthingaboutcomputersisnotthattheythinklesswellthanamanbutthattheythinkatall.Theearlyelectroniccomputerdidnothavemuchgoingforitexceptamarvelousmemoryandsomegoodmathskills.Buttodaythebestmodelscanbewireduptolearnbyexperiencefollowanargumentaskproperquestionsandwritepoetryandmusic.Theycanalsocarryonsomewhatpuzzlingconversations. Computersimitatelife.Ascomputersgetmorecompletetheimitationgetsbetter.Finallythelinebetweentheoriginalandthecopybecomesunclear.Inanother15yearsorsowewillseethecomputerasanewformoflife. Theopinionseemsridiculousbecauseforonethingcomputerslackthedrivesandemotionsoflivingcreatures.Butdrivescanbeprogrammedintothecomputer’’sbrainjustasnatureprogrammedthemintoourhumanbrainsasapartoftheequipmentforsurvival. Computersmatchpeopleinsomerolesandwhenfastdecisionsareneededinacrisistheyoftensurpassthem.Havingevolvedwhenthepaceoflifewasslowerthehumanbrainhasaninherentdefectthatpreventsitfromabsorbingseveralstreamsofinformationsimultaneouslyandactingonthemquickly.Throwtoomanythingsatthebrainatonetimeanditfreezesup. Wearestillincontrolbutthecapabilitiesofcomputersareincreasingatafantasticratewhilerawhumanintelligenceischangingslowlyifatall.Computerpowerhasincreasedtentimeseveryeightyearssince1946.Inthe1990swhenthesixthgenerationappearsthereasoningpowerofanintelligencebuiltoutofsiliconwillbegintomatchthatofthehumanbrain. Thatdoesnotmeantheevolutionofintelligencehasendedontheearth.Judgingbythepastwecanexpectthatanewspecieswillariseoutofmansurpassinghisachievementsashehassurpassedthoseofhispredecessor.Onlyacarbonchemistryenthusiastwouldassumethatthespeciesmustbeman’’sflesh-and-blooddescendants.Thenewkindofintelligentlifeismorelikelytobemadeofsilicon. Futuremanwillbemadeofsiliconinsteadoffleshandblood.
Shehadtolookafterahouseabiggardenandfivedogs{{U}}intothebargain{{/U}}.
BenjaminRushestablishedthefirstfree{{U}}dispensary{{/U}}intheUnitedStates.
Knitting Mymotherknewhowtoknit编织butshenevertaughtme.Sheassumedasdidmanywomenofhergenerationthatknittingwasnolongeraskillworthpassingdownfrommothertodaughter.Acombinationoffeminism女权主义andconsumerism浪费主义mademanywomenfeelthatsuchhomelyaccomplishmentswerenowoutofdate.MyGrandmotherstillknittedthoughandeveryChristmasshemadeapairofsocksformybrotherandmeofredwool.Theyweretheonesweworeunderouriceskates冰鞋whenitwasreallyimportanttohavewarmfeet. Knittingisanervoushabitthathappenstobeproductive.Ithelpedmequitsmokingbygivingmyhandssomethingelsetodo.Itiswonderfulfordepressionbecausenomatterwhatelsehappensyouarecreatingsomethingbeautiful.Timespentinfrontofthetelevisionorjustsittingisnolongertimewasted. Ilovebreathinglifeintothepatterns.It’’struemagicfindinganeglecteddog-earedoldbookwiththeperfectsnowflakedesignbuyingthesameGermantownwoolmygrandmotherusedintheexactbluetomatchmydaughter’’seyestakingitonthetrainwithmeeverydayfortwomonthsworkingenthusiasticallytogetitdonebyChristmasstayinguplateafterthestockingsarefilledtosewinthesleevesandweaveintheends. Knittinghastaughtmepatience.IknowthatifIjustkeepgoingevenifittakesmonthstherewillbeareward.WhenImakeamistakeIknowthatangerwillnotfixitthatIjusthavetogobackandtakeoutthestitches针脚betweenandstartoveragain. PeopleoftenaskifIwoulddoitformoneyandtheanswerisalwaysadefiniteno.InthefirstplaceyoucouldnotpaymeenoughforthehoursIputintoasweater.ButmoreimportantthisisanactivityIkeepseparatefromsuchconsiderations.IknittocovermychildrenandotherpeopleIloveinwarmthandcolor.Iknittogivethemsomethingearthlythatmoneycouldneverbuy. Knittinggivesmylifeanalternativerhythmtothedailydeadline.BydayIcanwriteaboutNorthernIrelandortheNewYorkCityPoliceDepartmentandgetpaidforitbutonthetrainhomesurroundedbypeoplewithlaptopsIstagemylittlerebellion.Itakeoutmyoldknittingbagandjointhecenturiesofwomenwhohaveknittedforlove. Theauthorworetheredsockshergrandmotherhadknittedforher______.
TheAttitudeForComputers AsDr.SamuelJohnsonsaidinadifferenteraaboutladiespreachingthesurprisingthingaboutcomputersisnotthattheythinklesswellthanamanbutthattheythinkatall.Theearlyelectroniccomputerdidnothavemuchgoingforitexceptamarvelousmemoryandsomegoodmathskills.Buttodaythebestmodelscanbewireduptolearnbyexperiencefollowanargumentaskproperquestionsandwritepoetryandmusic.Theycanalsocarryonsomewhatpuzzlingconversations. Computersimitatelife.Ascomputersgetmorecompletetheimitationgetsbetter.Finallythelinebetweentheoriginalandthecopybecomesunclear.Inanother15yearsorsowewillseethecomputerasanewformoflife. Theopinionseemsridiculousbecauseforonethingcomputerslackthedrivesandemotionsoflivingcreatures.Butdrivescanbeprogrammedintothecomputer’’sbrainjustasnatureprogrammedthemintoourhumanbrainsasapartoftheequipmentforsurvival. Computersmatchpeopleinsomerolesandwhenfastdecisionsareneededinacrisistheyoftensurpassthem.Havingevolvedwhenthepaceoflifewasslowerthehumanbrainhasaninherentdefectthatpreventsitfromabsorbingseveralstreamsofinformationsimultaneouslyandactingonthemquickly.Throwtoomanythingsatthebrainatonetimeanditfreezesup. Wearestillincontrolbutthecapabilitiesofcomputersareincreasingatafantasticratewhilerawhumanintelligenceischangingslowlyifatall.Computerpowerhasincreasedtentimeseveryeightyearssince1946.Inthe1990swhenthesixthgenerationappearsthereasoningpowerofanintelligencebuiltoutofsiliconwillbegintomatchthatofthehumanbrain. Thatdoesnotmeantheevolutionofintelligencehasendedontheearth.Judgingbythepastwecanexpectthatanewspecieswillariseoutofmansurpassinghisachievementsashehassurpassedthoseofhispredecessor.Onlyacarbonchemistryenthusiastwouldassumethatthespeciesmustbeman’’sflesh-and-blooddescendants.Thenewkindofintelligentlifeismorelikelytobemadeofsilicon. Somedayitwillbedifficulttotellacomputerfromaman.
Knitting Mymotherknewhowtoknit编织butshenevertaughtme.Sheassumedasdidmanywomenofhergenerationthatknittingwasnolongeraskillworthpassingdownfrommothertodaughter.Acombinationoffeminism女权主义andconsumerism浪费主义mademanywomenfeelthatsuchhomelyaccomplishmentswerenowoutofdate.MyGrandmotherstillknittedthoughandeveryChristmasshemadeapairofsocksformybrotherandmeofredwool.Theyweretheonesweworeunderouriceskates冰鞋whenitwasreallyimportanttohavewarmfeet. Knittingisanervoushabitthathappenstobeproductive.Ithelpedmequitsmokingbygivingmyhandssomethingelsetodo.Itiswonderfulfordepressionbecausenomatterwhatelsehappensyouarecreatingsomethingbeautiful.Timespentinfrontofthetelevisionorjustsittingisnolongertimewasted. Ilovebreathinglifeintothepatterns.It’’struemagicfindinganeglecteddog-earedoldbookwiththeperfectsnowflakedesignbuyingthesameGermantownwoolmygrandmotherusedintheexactbluetomatchmydaughter’’seyestakingitonthetrainwithmeeverydayfortwomonthsworkingenthusiasticallytogetitdonebyChristmasstayinguplateafterthestockingsarefilledtosewinthesleevesandweaveintheends. Knittinghastaughtmepatience.IknowthatifIjustkeepgoingevenifittakesmonthstherewillbeareward.WhenImakeamistakeIknowthatangerwillnotfixitthatIjusthavetogobackandtakeoutthestitches针脚betweenandstartoveragain. PeopleoftenaskifIwoulddoitformoneyandtheanswerisalwaysadefiniteno.InthefirstplaceyoucouldnotpaymeenoughforthehoursIputintoasweater.ButmoreimportantthisisanactivityIkeepseparatefromsuchconsiderations.IknittocovermychildrenandotherpeopleIloveinwarmthandcolor.Iknittogivethemsomethingearthlythatmoneycouldneverbuy. Knittinggivesmylifeanalternativerhythmtothedailydeadline.BydayIcanwriteaboutNorthernIrelandortheNewYorkCityPoliceDepartmentandgetpaidforitbutonthetrainhomesurroundedbypeoplewithlaptopsIstagemylittlerebellion.Itakeoutmyoldknittingbagandjointhecenturiesofwomenwhohaveknittedforlove. AccordingtothepassagewhichofthefollowingstatementsaboutknittingisNOTtrue?
HeartAttack IntheUnitedStatesandespeciallyinbigcitiesandruralareastensofthousandsofpeoplewithheartsthatshouldbegood【51】tokeepthemalivedieeachyearforlackofadequatefirstaid.InNewYorkCityforexampleanewstudyhasshownthatonlyonepersonin100outsideofhospitals【52】aftertheheartsuddenlystopspumping.IncontrastinSeattlethesurvival【53】aftersuchheartattacksisoneinfive. Thedifferencecanbetraced【54】theeffectivenessofthechainofsurvivalDr.JosephP.Ornatosaid.Eachlinkinthe【55】mustbestrongenoughformanylivestobe【56】. Thechainbeginswithanimmediatetelephone【57】foremergencyhelpandthestartwithinfourminutesoftheprocessneededforrestartingthe【58】workingbyafamilymemberorbystander旁观者. Itcontinueswiththepromptarrival-------withineight【59】tenminutesofarescuerequippedwithaspecialinstrumentthatcanshocktheheartbacktoanormalrhythm.Anditendswiththeadministration给予实施ofadvanced先进emergencycarebynursestomaintaintheheart’’sabilitytosurviveuntilthedoctorsatthehospitalscantake【60】Whenoneormorelinksinthischainfailorfunctiontooslowlythe【61】ofavictimsurvivingheartattackfallsrapidly.Becauseofwidespreadweaknessesinthechainof【62】expertsinemergencyheartcareestimatethat20000to80000people【63】needlesslyofheartattackeachyearanumbercomparabletothe55000killedannuallyinautomobile【64】. OneexpertsaysSendinganemergencyvehicletoaheartattackvictim【65】thespecialequipmentislikehavingpolicemenwithgunsbutnobullets.Theymayputonagoodshowbuttheylacktheweaponneededtogetthejobdone.
HeartAttack IntheUnitedStatesandespeciallyinbigcitiesandruralareastensofthousandsofpeoplewithheartsthatshouldbegood【51】tokeepthemalivedieeachyearforlackofadequatefirstaid.InNewYorkCityforexampleanewstudyhasshownthatonlyonepersonin100outsideofhospitals【52】aftertheheartsuddenlystopspumping.IncontrastinSeattlethesurvival【53】aftersuchheartattacksisoneinfive. Thedifferencecanbetraced【54】theeffectivenessofthechainofsurvivalDr.JosephP.Ornatosaid.Eachlinkinthe【55】mustbestrongenoughformanylivestobe【56】. Thechainbeginswithanimmediatetelephone【57】foremergencyhelpandthestartwithinfourminutesoftheprocessneededforrestartingthe【58】workingbyafamilymemberorbystander旁观者. Itcontinueswiththepromptarrival-------withineight【59】tenminutesofarescuerequippedwithaspecialinstrumentthatcanshocktheheartbacktoanormalrhythm.Anditendswiththeadministration给予实施ofadvanced先进emergencycarebynursestomaintaintheheart’’sabilitytosurviveuntilthedoctorsatthehospitalscantake【60】Whenoneormorelinksinthischainfailorfunctiontooslowlythe【61】ofavictimsurvivingheartattackfallsrapidly.Becauseofwidespreadweaknessesinthechainof【62】expertsinemergencyheartcareestimatethat20000to80000people【63】needlesslyofheartattackeachyearanumbercomparabletothe55000killedannuallyinautomobile【64】. OneexpertsaysSendinganemergencyvehicletoaheartattackvictim【65】thespecialequipmentislikehavingpolicemenwithgunsbutnobullets.Theymayputonagoodshowbuttheylacktheweaponneededtogetthejobdone.
Everyexperienceteachesthepeoplesomethingandtheeffectsare{{U}}cumulative{{/U}}.
{{*HTML*}} ??Antibioticresistancedoesn’tjust makepathogens病原体difficulttotreatItalsomakesthemhardertotrack Traditionallyepidemiologists流行病专家followingthepathsofdisease-causing microbeshaveidentifiedtheirsuspectsbyfeaturesofbacterial polysaccharide多糖coatssusceptibilitytodifferentantibioticsorother schemesButthesetrackingtechniquesarelosingtheirrelevance相关性实用性 saysAlexanderTomaszamicrobiologistatRockefellerUniversityinNewYork City.Withtheincreaseindrugresistanceavarietyofresistantmicrobescan nowwearthesamecoatorberesistanttothesamedrugsmakingitharderand hardertokeeptabsonindividualstrains菌株.?? Epidemiologiststhereforeareincreasinglyturningtomoreprecisemolecular typingtechniquessuchasDNAfingerprintingtodistinguishresistantstrains. ??DNAtypingtoolsareofcoursenotnew.Indeedsome DNA-basedmethodssuchascomparingplasmids质体smallringsofDNAoutside thechromosomes〈染色体〉havebeenusedbyepidemiologiststotrackinfections sincethe1970s.butsinceplasmidDNAistransferredeasilyandoftenbetween differentstrainsthattechniquetoohasitslimitations.?? ?Morerecenttechniquesuserestrictionenzymestocutapartentire bacterialchromosomesintostrain-specificfragmentpatternsAnothermethod usesspecificradiolabeled放射标汇的DNAprobesinatechniqueknownasSouthern hybridization杂交totestforthepresenceofaparticulardrug-resistancegene inabacterialstrain.Suchtoolsgiveepidemiologistsunprecedentedresolving powerforidentifyingreservoirsandtransitionroutesofgenesandpathogens saysTomasz.Thathashelpedresearcherstrackanumberofdrug-resistant clonesastheytravelvastdistances.???Suchtracking methodsalsohelpuslearnaboutthemechanismofresistancesays CDC疾病控制和预防中心epidemiologistRobertBreiman.Resistancegrowsheexplains eitherasoneresistantorganismspreadsfromonelocationtothenext—asinthe BrazilianMRSA耐甲氧苯青素金黄色葡萄球菌—orasdifferentstrainsandevenspeciesof microbessharethegenesresponsiblefordrugresistanceasaseriesofstudies ofvancomycin万古霉素resistancerecentlydemonstrated.??That knowledgealsohelpspublichealthofficialscombatthespread.Ifresistance spreadshorizontally’asamicrobeincreasesitsrangeBreimansaysit’s importanttofocuspreventioneffortsonminimizingperson-to-personspreadin hospitalsandday-carecenters.Ifhoweverresistancegenesarejumping betweenorganismsthatsuggeststhatoverlyaggressiveantibiotictreatmentis encouragingnonresistantbugstoacquirenewgenes.Insuchcasesthefocus needstobeoncontrollinganti-microbialusesaysBreiman.Thehoped-for result:fewerinfectionstotrack.Aspirinisoneoftheworld’soldestpainremedies.
{{*HTML*}} ??1.??AIDSisthefinal life-threateningstageofinfectionwithhumanimmuno-deficiencyvirusHIV. AIDSstandsforacquiredimmuno-deficiencysyndrome.Thenamereferstothefact thatHIVseverelydamagesthepatient’sdisease-fightingimmunesystem.Casesof AIDSwerefirstidentifiedin1981intheUnitedStatesbutresearchershave tracedcasestoasearlyas1969.MillionsofAIDScaseshavebeendiagnosed worldwide.??2.??AIDSiscausedbytwovirusesthat belongtoagroupcalledretroviruses.ThefirstAIDSviruswasisolatedby researchersinFrancein1983andresearchersintheUnitedStatesin1984.This virusbecameknownasHIV-1.in1985scientistsinFranceidentifiedanother closelyrelatedvirusthatalsoproducesAIDS.ThisvirusnamedHIV-2occurs mainlyinAfrica.HIV-1occursthroughouttheworld.??3.? ?PeopleinfectedwithHIVeventuallydevelopsymptomsthatalsomaybe causedbyotherlessseriousconditions.WithHIVinfectionhoweverthese symptomsareprolongedandoftenmoresevere.Theyincludeenlargedlymph glandstirednessfeverlossofappetiteandweightdiarrheayeast infectionsofthemouthandvaginaandnightsweats.??4.? ?AnHIV-infectedpersonmaydevelopAIDSfrom2to15ormoreyearsafter becominginfected.InchildrenbornwithHIVinfectionthisintervalisusually shorter.AfewpeoplewhohavebeeninfectedwithHIVformorethan15years havenotdevelopedanysymptomsorsufferonlyminorsymptoms.Aninfected personcantransmitthevirustoanotherpersonwhetherornotsymptomsare present.InfectionwithHIVappearstobelifelonginallwhobecomeinfected. ??5.??Researchershaveidentifiedthreewaysin whichHIVistransmitted:sexualintercoursedirectcontactwithinfected bloodandtransmissionfromaninfectedwomantoherfetusorbaby.Themost commonwayofbecominginfectedisthroughintimatesexualcontactwithan HIV-infectedperson.IntheUnitedStatessexualtransmissionofHIVhas occurredmainlyamonghomosexualmenbutitisbecomingmorefrequentamong heterosexualmenandwomen.??6.??Peoplewhoinject drugsintotheirbodiescanbeexposedtoinfectedbloodbysharinghypodermic needlessyringesorequipmentusedtopreparedrugsforinjection.Health-care workerscanbecomeinfectedwithHIVbycomingintodirectcontactwith ?infectedblood.Thismayoccurthroughinjurywithaneedleorothersharp instrumentusedintreatinganHIV-infectedpatient.Afewpatientshavebecome infectedwhilereceivingtreatmentfromanHIV-infecteddentist.? ?7.??AninfectedpregnantwomancantransmittheAIDSvirusto herfetusevenifshehasnosymptoms.Transmissionmayalsooccurfroman HIV-infectedmothertoherbabythroughbreast-feeding.??8. ??StudiesindicatethatHIVisnottransmittedthroughairfoodor waterorbyinsects.NoknowncasesofAIDShaveresultedfromsharingeating utensilsbathroomslockerroomslivingspaceor classrooms.Paragraph5______.
DefectiveGenesandHumanHealth Eachofuscarriesabouthalfadozendefective有缺点的genes.Weremainblissfully快乐地unawareofthisfactunlessweoroneofourcloserelativesareamongstthemanymillionswhosufferfromageneticdisease.Aboutoneintenpeoplehasorwilldevelopatsomelaterstageaninherited遗传的geneticdisorderandapproximately2800specificconditionsareknowntobecausedbydefectsmutationsinjustoneofthepatient’’sgenes.Somesinglegenedisordersarequitecommon-—cystic胞状的fibrosis纤维化isfoundinoneoutofevery2500babiesbornintheWesternWorld—andintotaldiseasesthatcanbetracedtosinglegenedefectsaccountforabout5%ofalladmissionstochildren’’shospitals. Mostofusdonotsufferanyharmfuleffectsfromourdefectivegenesbecausewecarrytwocopiesofnearlyallgenesonederivedfromourmotherandtheotherfromourfather.Theonlyexceptionstothisrulearethegenesfoundonthemalesexchromosomes染色体MaleshaveoneXandoneYchromosometheformerfromthemotherandthelatterfromthefathersoeachcellhasonlyonecopyofthegenesonthesechromosomes.Inthemajorityofcasesonenormalgeneissufficienttoavoidallthesymptomsofdisease.Ifthepotentiallyharmfulgeneisrecessive后退的thenitsnormalcounterpart配对的willcarryoutallthetasksassignedtoboth.Onlyifweinheritfromourparentstwocopiesofthesamerecessivegenewilladiseasedevelop. Ontheotherhandifthegeneisdominant显性的italonecanproducethediseaseevenifitscounterpartisnormal.Clearlyonlythechildrenofaparentwiththediseasecanbeaffectedandthenaverageonlyhalfthechildrenwillbeaffected.Huntington’’schorea舞蹈病aseverediseaseofthenervoussystemwhichbecomesapparentonlyinadulthoodisanexampleofadominantgeneticdisease. FinallytherearetheXchromosome-linkedgeneticdiseases.Asmaleshaveonlyonecopyofthegenesfromthischromosometherearenoothersavailabletofulfillthedefectivegene’’sfunction.ExamplesofsuchdiseasesareDuchennemusculardystrophy营养不良andperhapsmostwellknownofallhemophilia血友病. QueenVictoriawasacarrierofthedefectivegeneresponsibleforhemophiliaandthroughheritwastransmittedtotheroyalfamiliesofRussiaSpainandPrussia.MinorcutsandbruiseswhichwoulddolittleharmtomostpeoplecanprovefataltohemophiliacswholacktheproteinsFactorsVIIIandIV凝血因子VIII和IVinvolvedintheclotting血凝结ofbloodwhicharecodedforbythedefectivegenes.Sadlybeforetheseproteinsweremadeavailablethroughgeneticengineeringhemophiliacsweretreatedwithproteinsisolatedfromhumanblood.Someofthisbloodwascontaminated污损withtheAIDSvirusandhasresultedintragic悲惨的consequencesformanyhemophiliacs.Useofgeneticallyengineeredproteinsintherapeuticapplicationsratherthanbloodproductswillavoidtheseproblemsinthefuture. Notalldefectivegenesnecessarilyproducedetrimental有害的effectssincetheenvironmentinwhichthegeneoperatesisalsoofimportance.Aclassicexampleofageneticdiseasehavingabeneficialeffectonsurvivalisillustratedbytherelationshipbetweensickle-cell镶形血球anemia贫血症andmalaria疟病.Onlyindividualshavingtwocopiesofthesickle-cellgeneandonenormalgeneareunaffectedandmoreimportantlyareabletoresistinfection传染bymalarialparasites寄生虫.Theclearadvantageinthiscaseofhavingonedefectivegeneexplainswhythisgeneiscommoninpopulationsinthoseareasoftheworldwheremalariaisendemic特有的. Wecaninferfrompara.4that______.
HeartAttack IntheUnitedStatesandespeciallyinbigcitiesandruralareastensofthousandsofpeoplewithheartsthatshouldbegood【51】tokeepthemalivedieeachyearforlackofadequatefirstaid.InNewYorkCityforexampleanewstudyhasshownthatonlyonepersonin100outsideofhospitals【52】aftertheheartsuddenlystopspumping.IncontrastinSeattlethesurvival【53】aftersuchheartattacksisoneinfive. Thedifferencecanbetraced【54】theeffectivenessofthechainofsurvivalDr.JosephP.Ornatosaid.Eachlinkinthe【55】mustbestrongenoughformanylivestobe【56】. Thechainbeginswithanimmediatetelephone【57】foremergencyhelpandthestartwithinfourminutesoftheprocessneededforrestartingthe【58】workingbyafamilymemberorbystander旁观者. Itcontinueswiththepromptarrival-------withineight【59】tenminutesofarescuerequippedwithaspecialinstrumentthatcanshocktheheartbacktoanormalrhythm.Anditendswiththeadministration给予实施ofadvanced先进emergencycarebynursestomaintaintheheart’’sabilitytosurviveuntilthedoctorsatthehospitalscantake【60】Whenoneormorelinksinthischainfailorfunctiontooslowlythe【61】ofavictimsurvivingheartattackfallsrapidly.Becauseofwidespreadweaknessesinthechainof【62】expertsinemergencyheartcareestimatethat20000to80000people【63】needlesslyofheartattackeachyearanumbercomparabletothe55000killedannuallyinautomobile【64】. OneexpertsaysSendinganemergencyvehicletoaheartattackvictim【65】thespecialequipmentislikehavingpolicemenwithgunsbutnobullets.Theymayputonagoodshowbuttheylacktheweaponneededtogetthejobdone.
DefectiveGenesandHumanHealth Eachofuscarriesabouthalfadozendefective有缺点的genes.Weremainblissfully快乐地unawareofthisfactunlessweoroneofourcloserelativesareamongstthemanymillionswhosufferfromageneticdisease.Aboutoneintenpeoplehasorwilldevelopatsomelaterstageaninherited遗传的geneticdisorderandapproximately2800specificconditionsareknowntobecausedbydefectsmutationsinjustoneofthepatient’’sgenes.Somesinglegenedisordersarequitecommon-—cystic胞状的fibrosis纤维化isfoundinoneoutofevery2500babiesbornintheWesternWorld—andintotaldiseasesthatcanbetracedtosinglegenedefectsaccountforabout5%ofalladmissionstochildren’’shospitals. Mostofusdonotsufferanyharmfuleffectsfromourdefectivegenesbecausewecarrytwocopiesofnearlyallgenesonederivedfromourmotherandtheotherfromourfather.Theonlyexceptionstothisrulearethegenesfoundonthemalesexchromosomes染色体MaleshaveoneXandoneYchromosometheformerfromthemotherandthelatterfromthefathersoeachcellhasonlyonecopyofthegenesonthesechromosomes.Inthemajorityofcasesonenormalgeneissufficienttoavoidallthesymptomsofdisease.Ifthepotentiallyharmfulgeneisrecessive后退的thenitsnormalcounterpart配对的willcarryoutallthetasksassignedtoboth.Onlyifweinheritfromourparentstwocopiesofthesamerecessivegenewilladiseasedevelop. Ontheotherhandifthegeneisdominant显性的italonecanproducethediseaseevenifitscounterpartisnormal.Clearlyonlythechildrenofaparentwiththediseasecanbeaffectedandthenaverageonlyhalfthechildrenwillbeaffected.Huntington’’schorea舞蹈病aseverediseaseofthenervoussystemwhichbecomesapparentonlyinadulthoodisanexampleofadominantgeneticdisease. FinallytherearetheXchromosome-linkedgeneticdiseases.Asmaleshaveonlyonecopyofthegenesfromthischromosometherearenoothersavailabletofulfillthedefectivegene’’sfunction.ExamplesofsuchdiseasesareDuchennemusculardystrophy营养不良andperhapsmostwellknownofallhemophilia血友病. QueenVictoriawasacarrierofthedefectivegeneresponsibleforhemophiliaandthroughheritwastransmittedtotheroyalfamiliesofRussiaSpainandPrussia.MinorcutsandbruiseswhichwoulddolittleharmtomostpeoplecanprovefataltohemophiliacswholacktheproteinsFactorsVIIIandIV凝血因子VIII和IVinvolvedintheclotting血凝结ofbloodwhicharecodedforbythedefectivegenes.Sadlybeforetheseproteinsweremadeavailablethroughgeneticengineeringhemophiliacsweretreatedwithproteinsisolatedfromhumanblood.Someofthisbloodwascontaminated污损withtheAIDSvirusandhasresultedintragic悲惨的consequencesformanyhemophiliacs.Useofgeneticallyengineeredproteinsintherapeuticapplicationsratherthanbloodproductswillavoidtheseproblemsinthefuture. Notalldefectivegenesnecessarilyproducedetrimental有害的effectssincetheenvironmentinwhichthegeneoperatesisalsoofimportance.Aclassicexampleofageneticdiseasehavingabeneficialeffectonsurvivalisillustratedbytherelationshipbetweensickle-cell镶形血球anemia贫血症andmalaria疟病.Onlyindividualshavingtwocopiesofthesickle-cellgeneandonenormalgeneareunaffectedandmoreimportantlyareabletoresistinfection传染bymalarialparasites寄生虫.Theclearadvantageinthiscaseofhavingonedefectivegeneexplainswhythisgeneiscommoninpopulationsinthoseareasoftheworldwheremalariaisendemic特有的. thediseasepara.7refersto______.
Thewoman's{{U}}scowl{{/U}}showedshewasnotsatisfiedwiththeservicehere.
热门题库
更多
理工类
卫生类
综合类
国际货运代理师
报关水平测试
报检员
物流员(四级)
助理物流师(三级)
物流师(二级)
高级物流师(一级)
物流案例分析
单证员基础理论与知识
单证员缮制与操作
国际货运代理理论与实务
外贸综合业务
外贸外语
湘公网安备 43130202000226号