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? ?阅读下面这篇短文，短文后列出了7个句子，请根据短文的内容对每个句子做出判断。 ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? {{B}}Using HIV Virus to...
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NaturalMedicines Sinceearliestdayshumanshaveusedsomekindsofmedicines.Weknowthisbecausehumanshavesurvived.Ancienttreatmentsforinjuryanddiseaseweresuccessfulenoughtokeephumansfromdyingoutcompletely. Theyweresuccessfullongbeforethetimeofmodernmedicine.Beforethetimeofdoctorswithwhitecoatsandshiny发亮的instruments.Beforethetimeofbighospitalswithstrangeandwonderfulequipment. Manypartsoftheworldstilldonothaveuniversity-educateddoctors.Nordotheyhaveexpensivehospitals.Yetinjuriesaretreated.Anddiseasesareoftencured.How?Byancientmethods.Bymedicinesthatmightseemmysteriousevenmagical有魔力的.Traditionalmedicinesareneithermysteriousnormagicalhowever. Throughthecenturiestribal部落的medicinemenexperimentedwithplants.Theyfoundmanyusefulchemicalsintheplants.Andscientistsbelievemanyofthesetraditionalmedicinesmayprovidethecureforsomeoftoday’’smostseriousdiseases. Expertssayalmost80%ofthepeopleintheworlduseplantsforhealthcare.Thesenaturalmedicinesareusednotjustbecausepeoplehavenootherformoftreatment.Theyareusedbecausepeopletrustthem.Indevelopedareasfewpeoplethinkaboutthesourceofthemedicinestheybuyinastore.Yetmanywidely-usedmedicinesarefromancientsourcesespeciallyplants.Someexpertssaymorethan25%ofmodernmedicinescomeinonewayoranotherfromnature. Scientistshavelongknownthatnatureisreallyachemicalfactory.Alllivingthingscontainchemicalsthathelpthemsurvive.Soscientists’interestintraditionalmedicineisnotnew.Butithasbecomeanurgentconcern.Thisisbecausetheearth’’ssupplyofnaturalmedicinesmaybedroppingrapidly. Whatdothemajorityofthepeopleintheworlduseforhealthcare?
Istheclockinthetoweraccurate?
NewTechniquePromisesEarlierCancerDetection AnewtechniquecouldrevolutionizetheearlydetectionofcancergivingsufferersagreaterchanceofbeatingthediseaseAmericanscientistssaid.ResearchersattheMassachusettsInstituteofTechnologyhavedevisedanovelmethodof【51】changesinthenucleusofcellsintheearlieststagesofthedisease.Morethan85percentofallcancersoriginateintheepithelium上皮thatlinestheinternalsurfacesoforgans【52】thebody.Althoughthesearetreatable【53】theyarediagnosedinoneofthepreventablestagesearlybodydamagesarealmost【54】todetectsaidscientistFeld.Wepresentanewoptical-probe光学探子techniquebasedonlight-scatteringspectroscopy分光镜检查thatisable【55】detectprecancerousandearlycancerouscellsincell-richepitheliaheaddedinastatement. Thenewtechniquereliesonthefact【56】cellnucleichangeintheearlystagesofcancerandthedifferencesscatterlightinacharacteristicway.Untilnowthechangeswereonlydetectable【57】abiopsy活检wastakenthescientistssaid.Thenewtechnique【58】inthesciencejournalNaturecanbeusedinconjunctionwitharoutinecancerscreeningandsurveillancetechniquewhichusesanendoscope内窥镜—aflexibleopticalprobe【59】withcameraswhichisinsertedintoacavityinthebody—tocheck【60】cancers. Thescientistssaidthey【61】theirnewtechniqueinfourdifferentorgansduringroutineendoscopiccancerscreening.Thetipoftheopticalprobewasbroughtintocontactwiththetissuetobetestedandthescatteringoflightwasrecordedwithouttheneedforanytissuetobe【62】thescientistssaid.Ourresultsshowthatlight-scatteringspectroscopyhasthepotentialtodetectpre-cancerousbodydamagesandpreinvasivecancersthroughoutthebody.Thistechniqueshould【63】improvetheefficiencyofcancerscreeningandsurveillancethescientistssaid.Cancerisoneofthebiggest【64】inindustrializedcountries.【65】tofiguresfromtheWorldHealthOrganization10millionpeoplewerediagnosedwiththediseaseworldwidein1997andsixmilliondied.
OnAntibodies Substancesforeigntothebodysuchasdisease-causingbacteriaandvirusesandotherinfectiousagentsarerecognizedbythebodysimmunesystemasinvaders.Ournaturaldefensesagainsttheseinfectiousagentsareantibodiesproteinsthatseekouttheantigens抗原andhelpdestroythem. Antibodieshavetwoveryusefulcharacteristics.Firsttheyareextremelyspecific;thatiseachantibodybindstoandattacksoneparticularantigen.Secondsomeantibodiesonceactivatedbytheoccurrenceofadiseasecontinuetoconferresistanceagainstthatdisease.Classicexamplearetheantibodiestothechildhooddiseasesofchickenpox水痘andmeasles. Thesecondcharacteristicofantibodiesmakesitpossibletodevelopvaccines.Avaccine痘苗isapreparationofkilledorweakenedbacteriaorvirusesthatwhenintroducedintothebodystimulatestheproductionofantibodiesagainsttheantigensitcontains. Itisthefirsttraitofantibodiestheirspecificitythatmakesmonoclonalantibodytechnologysovaluable.Notonlycanantibodiesbeusedtherapeutically在治疗上toprotectagainstdisease;theycanalsohelpto.diagnoseawidevarietyofillnessesandcandetectthepresenceofdrugsviralandbacterialproductsandotherunusualorabnormalsubstancesintheblood. Givensuchadiversityofusesforthesediseased-fightingsubstancestheirproductioninpurequantitieshaslongbeenthefocusofscientificinvestigation.Theconventionalmethodwastoinjectalaboratoryanimalwithanantigenandthenafterantibodieshadbeenformedcollectthoseantibodiesfromthebloodserum血清Antibodycontainingbloodserumiscalledantiserum抗血清.Therearetwoproblemswiththismethod:Ityieldsantiserumthatcontainsundesiredsubstancesanditprovidesaverysmallamountofusableantibody. Monoclonalantibodytechnologyallowsustoproducelargeamountsofpureantibodies.inthefollowingway:wecanobtaincellsthatproduceantibodiesnaturally;wealsohaveavailableaclassofcellsthatcangrowcontinuallyincellculture培养.Ifweformahybrid混血儿thatcombinesthecharacteristicofimmortality永生withtheabilitytoproducethedesiredsubstancewewouldhaveineffectafactorytoproduceantibodiesthatworkaroundtheclock. Inmonoclonalantibodytechnologytumorcellsthatcanreplicate重复endlesslyarefusedwithmammaliancellsthatproduceanantibody.Theresultofthiscellfusionisahybridoma杂交瘤whichwillcontinuallyproduceantibodies.Theseantibodiesarecalledmonoclonalbecausetheycomefromonlyonetypeofcellthehybridomacell;antibodiesproducedbyconventionalmethodsontheotherhandarederivedfrompreparationscontainingmanykindsofcellsandhencearecalledpolyclonal.Anexampleofhowmonoclonalantibodiesarederivedisdescribedbelow. Amyelomaisatumorofthebonemarrow骨髓thatcanbeadaptedtogrowpermanendyincellculture.Whenmyelomacellswerefusedwithantibody-producingmammalianspleencellsitwasfoundthattheresultinghybridcellsorhybridomasproducedlargeamountsofmonoclonal骨髓瘤antibody.Thisproductofcellfusioncombinedthedesiredqualitiesofthetwodifferenttypesofcells:theabilitytogrowcontinuallyandtheabilitytoproducelargeamountsofpureantibody. Becauseselectedhybridcellsproduceonlyonespecificantibodytheyaremorepurethanthepolyclonalantibodiesproducedbyconventionaltechniques.Theyarepotentiallymoreeffectivethanconventionaldrugsinfightingdiseasesincedrugsattacknotonlytheforeignsubstancebutthebody’sowncellsaswellsometimesproducingundesirablesideeffectssuchasnausea恶心andallergicreactions.Monoclonalantibodiesattackthetargetmoleculeandonlythetargetmoleculewithnoorgreatlydiminishedsideeffects. Whichofthefollowingstatementsisfalse?
TheFunctionofTomatoes Howdowelovetomatoes?Let’’scounttheways:welovetheminpastaonpizzainjuiceinsaladandsoupslicedonsandwichesstuffedwithtunaevendriedandbakedinbagelsbutmostofallwelovethemrightoffvine—riperedanddelicious. Whiletomatoloversdon’’tneedanexcuseforeatingthembythebushel蒲式耳nowthere’’sevenmorereasontosavorthesedeliciousfruits.Evidenceismountingthatpeoplewhoeattomatoeshaveasubstantiallylowerriskforcancer. Inathousand-personstudyofeatinghabitsandhealthHarvardMedicalSchoolresearchersfoundthatthosewhoatetomatoeseveryweekhadthelowestchanceofdyingformcancer. Recentlyastudyof48000Americanmenshoweda21to34percentlowerriskforprostatecancer前列腺癌amongthosewhoconsumedtomatoestomatosauceorpizzamorethantwiceaweek.AndinstudyofmenandwomeninItalyeatingsevenormoreservingofrawtomatoesaweekwaslinkedtoa30to60percentreductionindigestivetractandprostatecancersdependingonthetypeofcancer. Theprotectivequalitiesofthetomatoarethoughttocomefromlycopene番茄红素apotentantioxidant抗氧化的plantchemicalthatisabundantintomatoes.Lycopeneisresponsiblefortheredcoloroftomatoes;thedarkerredthetomatoisthemorelycopeneitcontains.Greenandyellowtomatoesdonotcontainlycopene. Lycopoeneisalsofoundinwatermelonandpinkgrapefruitbuttomatoesarethemostabundantsource.Cookingenhancesthelycopenemoreavailable.Thustomatosauceandpasteisevenabettersourceforlycopenethanfreshrawtomatoes.Lycopeneisfatsolubleandmustbeconsumedwithacertainamountoffattobeabsorbedbythebody.Tomatorecipesmustcontainamoderateamountofoiltoensurethatalongwithadelicioustastetreatyouwillalsobereceivingallthehealthbenefitstomatoeshavetooffer. Inordertobeabsorbedbybody______.
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______.
Interferon Forseveralyearsscientistshavebeentestingasubstancecalledinterferon干扰素apotentialwonderdrugthatisprovingtobeeffectiveintreatingavarietyofailmentsincludingvirusinfectionsbacteriainfectionsandtumors.Todatethenewdrughasprovokednonegativereactionofsufficientsignificancetodiscourageitsuse.Butinspiteofitssuccesslastyearonlyonegramwasproducedintheentireworld. Thereasonforthescarcityliesinthestructureofinterferon.Aspeciesspecificproteintheinterferonproducedfromoneanimalspeciescannotbeusedintreatinganotheranimalspecies.Inotherwordstotreathumanbeingsonlyinterferonproducedbyhumanbeingsmaybeused.Thedrugisproducedbyinfectingwhitebloodcellswithavirus.Fortunatelyitissopotentthattheamountgiveneachpatientperinjectionisverysmall. Unlikeantibiotics抗菌素interferondoesnotattackgermsdirectly.Insteaditmakesunaffectedcellsresistanttoinfectionandpreventsthemultiplicationofviruseswithincells. Asyoumightconcludeoneofthemostdramaticusesofinterferonhasbeeninthetreatmentofcancer.Dr.HansStranderresearchphysicianatSweden’’sfamousKarolinskaInstitutehastreatedmorethanonehundredcancerpatientswiththenewdrug.Amongagroupofselectedpatientswhohadundergonesurgicalproceduresforadvancedcancerhalfweregivenconventionaltreatmentsandtheotherhalfweregiveninterferon.Thesurvivalrateoverathree-yearperiodwas70percentamongthosewhoweretreatedwithinterferonascomparedwithonly10to30percentamongthosewhohadreceivedtheconventionaltreatments. IntheUnitedStatesalarge-scaleprojectsupportedbytheAmericanCancerSocietyisnowunderway.Iftheexperimentissuccessfulinterferoncouldbecomeoneofthegreatestmedicaldiscoveriesofourtime. Interferonhasnotbeenwidelyusedbecauseitisstillverydangerous.
Thetechniciansconductedinvestigationsbeforetheyputforwardthesuggestionsatthemeeting.
Thedevelopmentofthetransistorandintegratedcircuitsrevolutionizedtheelectronicsindustrybyallowingcomponentstobepackagedmoredensely.
OnAntibodies Substancesforeigntothebodysuchasdisease-causingbacteriaandvirusesandotherinfectiousagentsarerecognizedbythebodysimmunesystemasinvaders.Ournaturaldefensesagainsttheseinfectiousagentsareantibodiesproteinsthatseekouttheantigens抗原andhelpdestroythem. Antibodieshavetwoveryusefulcharacteristics.Firsttheyareextremelyspecific;thatiseachantibodybindstoandattacksoneparticularantigen.Secondsomeantibodiesonceactivatedbytheoccurrenceofadiseasecontinuetoconferresistanceagainstthatdisease.Classicexamplearetheantibodiestothechildhooddiseasesofchickenpox水痘andmeasles. Thesecondcharacteristicofantibodiesmakesitpossibletodevelopvaccines.Avaccine痘苗isapreparationofkilledorweakenedbacteriaorvirusesthatwhenintroducedintothebodystimulatestheproductionofantibodiesagainsttheantigensitcontains. Itisthefirsttraitofantibodiestheirspecificitythatmakesmonoclonalantibodytechnologysovaluable.Notonlycanantibodiesbeusedtherapeutically在治疗上toprotectagainstdisease;theycanalsohelpto.diagnoseawidevarietyofillnessesandcandetectthepresenceofdrugsviralandbacterialproductsandotherunusualorabnormalsubstancesintheblood. Givensuchadiversityofusesforthesediseased-fightingsubstancestheirproductioninpurequantitieshaslongbeenthefocusofscientificinvestigation.Theconventionalmethodwastoinjectalaboratoryanimalwithanantigenandthenafterantibodieshadbeenformedcollectthoseantibodiesfromthebloodserum血清Antibodycontainingbloodserumiscalledantiserum抗血清.Therearetwoproblemswiththismethod:Ityieldsantiserumthatcontainsundesiredsubstancesanditprovidesaverysmallamountofusableantibody. Monoclonalantibodytechnologyallowsustoproducelargeamountsofpureantibodies.inthefollowingway:wecanobtaincellsthatproduceantibodiesnaturally;wealsohaveavailableaclassofcellsthatcangrowcontinuallyincellculture培养.Ifweformahybrid混血儿thatcombinesthecharacteristicofimmortality永生withtheabilitytoproducethedesiredsubstancewewouldhaveineffectafactorytoproduceantibodiesthatworkaroundtheclock. Inmonoclonalantibodytechnologytumorcellsthatcanreplicate重复endlesslyarefusedwithmammaliancellsthatproduceanantibody.Theresultofthiscellfusionisahybridoma杂交瘤whichwillcontinuallyproduceantibodies.Theseantibodiesarecalledmonoclonalbecausetheycomefromonlyonetypeofcellthehybridomacell;antibodiesproducedbyconventionalmethodsontheotherhandarederivedfrompreparationscontainingmanykindsofcellsandhencearecalledpolyclonal.Anexampleofhowmonoclonalantibodiesarederivedisdescribedbelow. Amyelomaisatumorofthebonemarrow骨髓thatcanbeadaptedtogrowpermanendyincellculture.Whenmyelomacellswerefusedwithantibody-producingmammalianspleencellsitwasfoundthattheresultinghybridcellsorhybridomasproducedlargeamountsofmonoclonal骨髓瘤antibody.Thisproductofcellfusioncombinedthedesiredqualitiesofthetwodifferenttypesofcells:theabilitytogrowcontinuallyandtheabilitytoproducelargeamountsofpureantibody. Becauseselectedhybridcellsproduceonlyonespecificantibodytheyaremorepurethanthepolyclonalantibodiesproducedbyconventionaltechniques.Theyarepotentiallymoreeffectivethanconventionaldrugsinfightingdiseasesincedrugsattacknotonlytheforeignsubstancebutthebody’sowncellsaswellsometimesproducingundesirablesideeffectssuchasnausea恶心andallergicreactions.Monoclonalantibodiesattackthetargetmoleculeandonlythetargetmoleculewithnoorgreatlydiminishedsideeffects. Whichofthefollowingsubstancesisnotaninvadertothebody’simmunesystem?
TheshortstoriesofKatherineMansfielddemonstrateherkeenperceptionsofhumancharacter.
NewTechniquePromisesEarlierCancerDetection AnewtechniquecouldrevolutionizetheearlydetectionofcancergivingsufferersagreaterchanceofbeatingthediseaseAmericanscientistssaid.ResearchersattheMassachusettsInstituteofTechnologyhavedevisedanovelmethodof【51】changesinthenucleusofcellsintheearlieststagesofthedisease.Morethan85percentofallcancersoriginateintheepithelium上皮thatlinestheinternalsurfacesoforgans【52】thebody.Althoughthesearetreatable【53】theyarediagnosedinoneofthepreventablestagesearlybodydamagesarealmost【54】todetectsaidscientistFeld.Wepresentanewoptical-probe光学探子techniquebasedonlight-scatteringspectroscopy分光镜检查thatisable【55】detectprecancerousandearlycancerouscellsincell-richepitheliaheaddedinastatement. Thenewtechniquereliesonthefact【56】cellnucleichangeintheearlystagesofcancerandthedifferencesscatterlightinacharacteristicway.Untilnowthechangeswereonlydetectable【57】abiopsy活检wastakenthescientistssaid.Thenewtechnique【58】inthesciencejournalNaturecanbeusedinconjunctionwitharoutinecancerscreeningandsurveillancetechniquewhichusesanendoscope内窥镜—aflexibleopticalprobe【59】withcameraswhichisinsertedintoacavityinthebody—tocheck【60】cancers. Thescientistssaidthey【61】theirnewtechniqueinfourdifferentorgansduringroutineendoscopiccancerscreening.Thetipoftheopticalprobewasbroughtintocontactwiththetissuetobetestedandthescatteringoflightwasrecordedwithouttheneedforanytissuetobe【62】thescientistssaid.Ourresultsshowthatlight-scatteringspectroscopyhasthepotentialtodetectpre-cancerousbodydamagesandpreinvasivecancersthroughoutthebody.Thistechniqueshould【63】improvetheefficiencyofcancerscreeningandsurveillancethescientistssaid.Cancerisoneofthebiggest【64】inindustrializedcountries.【65】tofiguresfromtheWorldHealthOrganization10millionpeoplewerediagnosedwiththediseaseworldwidein1997andsixmilliondied.
Thecollegeofferscoursesinavarietyoftrades.
Interferon Forseveralyearsscientistshavebeentestingasubstancecalledinterferon干扰素apotentialwonderdrugthatisprovingtobeeffectiveintreatingavarietyofailmentsincludingvirusinfectionsbacteriainfectionsandtumors.Todatethenewdrughasprovokednonegativereactionofsufficientsignificancetodiscourageitsuse.Butinspiteofitssuccesslastyearonlyonegramwasproducedintheentireworld. Thereasonforthescarcityliesinthestructureofinterferon.Aspeciesspecificproteintheinterferonproducedfromoneanimalspeciescannotbeusedintreatinganotheranimalspecies.Inotherwordstotreathumanbeingsonlyinterferonproducedbyhumanbeingsmaybeused.Thedrugisproducedbyinfectingwhitebloodcellswithavirus.Fortunatelyitissopotentthattheamountgiveneachpatientperinjectionisverysmall. Unlikeantibiotics抗菌素interferondoesnotattackgermsdirectly.Insteaditmakesunaffectedcellsresistanttoinfectionandpreventsthemultiplicationofviruseswithincells. Asyoumightconcludeoneofthemostdramaticusesofinterferonhasbeeninthetreatmentofcancer.Dr.HansStranderresearchphysicianatSweden’’sfamousKarolinskaInstitutehastreatedmorethanonehundredcancerpatientswiththenewdrug.Amongagroupofselectedpatientswhohadundergonesurgicalproceduresforadvancedcancerhalfweregivenconventionaltreatmentsandtheotherhalfweregiveninterferon.Thesurvivalrateoverathree-yearperiodwas70percentamongthosewhoweretreatedwithinterferonascomparedwithonly10to30percentamongthosewhohadreceivedtheconventionaltreatments. IntheUnitedStatesalarge-scaleprojectsupportedbytheAmericanCancerSocietyisnowunderway.Iftheexperimentissuccessfulinterferoncouldbecomeoneofthegreatestmedicaldiscoveriesofourtime. Theeffectinterferonhasoninfectionisthatitkeepshealthycellsfrombecominginfected.
Interferon Forseveralyearsscientistshavebeentestingasubstancecalledinterferon干扰素apotentialwonderdrugthatisprovingtobeeffectiveintreatingavarietyofailmentsincludingvirusinfectionsbacteriainfectionsandtumors.Todatethenewdrughasprovokednonegativereactionofsufficientsignificancetodiscourageitsuse.Butinspiteofitssuccesslastyearonlyonegramwasproducedintheentireworld. Thereasonforthescarcityliesinthestructureofinterferon.Aspeciesspecificproteintheinterferonproducedfromoneanimalspeciescannotbeusedintreatinganotheranimalspecies.Inotherwordstotreathumanbeingsonlyinterferonproducedbyhumanbeingsmaybeused.Thedrugisproducedbyinfectingwhitebloodcellswithavirus.Fortunatelyitissopotentthattheamountgiveneachpatientperinjectionisverysmall. Unlikeantibiotics抗菌素interferondoesnotattackgermsdirectly.Insteaditmakesunaffectedcellsresistanttoinfectionandpreventsthemultiplicationofviruseswithincells. Asyoumightconcludeoneofthemostdramaticusesofinterferonhasbeeninthetreatmentofcancer.Dr.HansStranderresearchphysicianatSweden’’sfamousKarolinskaInstitutehastreatedmorethanonehundredcancerpatientswiththenewdrug.Amongagroupofselectedpatientswhohadundergonesurgicalproceduresforadvancedcancerhalfweregivenconventionaltreatmentsandtheotherhalfweregiveninterferon.Thesurvivalrateoverathree-yearperiodwas70percentamongthosewhoweretreatedwithinterferonascomparedwithonly10to30percentamongthosewhohadreceivedtheconventionaltreatments. IntheUnitedStatesalarge-scaleprojectsupportedbytheAmericanCancerSocietyisnowunderway.Iftheexperimentissuccessfulinterferoncouldbecomeoneofthegreatestmedicaldiscoveriesofourtime. 21Interferoncauseshealthycellstogrow.
Themachinemustbeoperatedbyhand.Itisn’’tautomatic.
NewTechniquePromisesEarlierCancerDetection AnewtechniquecouldrevolutionizetheearlydetectionofcancergivingsufferersagreaterchanceofbeatingthediseaseAmericanscientistssaid.ResearchersattheMassachusettsInstituteofTechnologyhavedevisedanovelmethodof【51】changesinthenucleusofcellsintheearlieststagesofthedisease.Morethan85percentofallcancersoriginateintheepithelium上皮thatlinestheinternalsurfacesoforgans【52】thebody.Althoughthesearetreatable【53】theyarediagnosedinoneofthepreventablestagesearlybodydamagesarealmost【54】todetectsaidscientistFeld.Wepresentanewoptical-probe光学探子techniquebasedonlight-scatteringspectroscopy分光镜检查thatisable【55】detectprecancerousandearlycancerouscellsincell-richepitheliaheaddedinastatement. Thenewtechniquereliesonthefact【56】cellnucleichangeintheearlystagesofcancerandthedifferencesscatterlightinacharacteristicway.Untilnowthechangeswereonlydetectable【57】abiopsy活检wastakenthescientistssaid.Thenewtechnique【58】inthesciencejournalNaturecanbeusedinconjunctionwitharoutinecancerscreeningandsurveillancetechniquewhichusesanendoscope内窥镜—aflexibleopticalprobe【59】withcameraswhichisinsertedintoacavityinthebody—tocheck【60】cancers. Thescientistssaidthey【61】theirnewtechniqueinfourdifferentorgansduringroutineendoscopiccancerscreening.Thetipoftheopticalprobewasbroughtintocontactwiththetissuetobetestedandthescatteringoflightwasrecordedwithouttheneedforanytissuetobe【62】thescientistssaid.Ourresultsshowthatlight-scatteringspectroscopyhasthepotentialtodetectpre-cancerousbodydamagesandpreinvasivecancersthroughoutthebody.Thistechniqueshould【63】improvetheefficiencyofcancerscreeningandsurveillancethescientistssaid.Cancerisoneofthebiggest【64】inindustrializedcountries.【65】tofiguresfromtheWorldHealthOrganization10millionpeoplewerediagnosedwiththediseaseworldwidein1997andsixmilliondied.
NewTechniquePromisesEarlierCancerDetection AnewtechniquecouldrevolutionizetheearlydetectionofcancergivingsufferersagreaterchanceofbeatingthediseaseAmericanscientistssaid.ResearchersattheMassachusettsInstituteofTechnologyhavedevisedanovelmethodof【51】changesinthenucleusofcellsintheearlieststagesofthedisease.Morethan85percentofallcancersoriginateintheepithelium上皮thatlinestheinternalsurfacesoforgans【52】thebody.Althoughthesearetreatable【53】theyarediagnosedinoneofthepreventablestagesearlybodydamagesarealmost【54】todetectsaidscientistFeld.Wepresentanewoptical-probe光学探子techniquebasedonlight-scatteringspectroscopy分光镜检查thatisable【55】detectprecancerousandearlycancerouscellsincell-richepitheliaheaddedinastatement. Thenewtechniquereliesonthefact【56】cellnucleichangeintheearlystagesofcancerandthedifferencesscatterlightinacharacteristicway.Untilnowthechangeswereonlydetectable【57】abiopsy活检wastakenthescientistssaid.Thenewtechnique【58】inthesciencejournalNaturecanbeusedinconjunctionwitharoutinecancerscreeningandsurveillancetechniquewhichusesanendoscope内窥镜—aflexibleopticalprobe【59】withcameraswhichisinsertedintoacavityinthebody—tocheck【60】cancers. Thescientistssaidthey【61】theirnewtechniqueinfourdifferentorgansduringroutineendoscopiccancerscreening.Thetipoftheopticalprobewasbroughtintocontactwiththetissuetobetestedandthescatteringoflightwasrecordedwithouttheneedforanytissuetobe【62】thescientistssaid.Ourresultsshowthatlight-scatteringspectroscopyhasthepotentialtodetectpre-cancerousbodydamagesandpreinvasivecancersthroughoutthebody.Thistechniqueshould【63】improvetheefficiencyofcancerscreeningandsurveillancethescientistssaid.Cancerisoneofthebiggest【64】inindustrializedcountries.【65】tofiguresfromtheWorldHealthOrganization10millionpeoplewerediagnosedwiththediseaseworldwidein1997andsixmilliondied.
Thetownisfamousforitsmagnificentchurchtowers.
NewTechniquePromisesEarlierCancerDetection AnewtechniquecouldrevolutionizetheearlydetectionofcancergivingsufferersagreaterchanceofbeatingthediseaseAmericanscientistssaid.ResearchersattheMassachusettsInstituteofTechnologyhavedevisedanovelmethodof【51】changesinthenucleusofcellsintheearlieststagesofthedisease.Morethan85percentofallcancersoriginateintheepithelium上皮thatlinestheinternalsurfacesoforgans【52】thebody.Althoughthesearetreatable【53】theyarediagnosedinoneofthepreventablestagesearlybodydamagesarealmost【54】todetectsaidscientistFeld.Wepresentanewoptical-probe光学探子techniquebasedonlight-scatteringspectroscopy分光镜检查thatisable【55】detectprecancerousandearlycancerouscellsincell-richepitheliaheaddedinastatement. Thenewtechniquereliesonthefact【56】cellnucleichangeintheearlystagesofcancerandthedifferencesscatterlightinacharacteristicway.Untilnowthechangeswereonlydetectable【57】abiopsy活检wastakenthescientistssaid.Thenewtechnique【58】inthesciencejournalNaturecanbeusedinconjunctionwitharoutinecancerscreeningandsurveillancetechniquewhichusesanendoscope内窥镜—aflexibleopticalprobe【59】withcameraswhichisinsertedintoacavityinthebody—tocheck【60】cancers. Thescientistssaidthey【61】theirnewtechniqueinfourdifferentorgansduringroutineendoscopiccancerscreening.Thetipoftheopticalprobewasbroughtintocontactwiththetissuetobetestedandthescatteringoflightwasrecordedwithouttheneedforanytissuetobe【62】thescientistssaid.Ourresultsshowthatlight-scatteringspectroscopyhasthepotentialtodetectpre-cancerousbodydamagesandpreinvasivecancersthroughoutthebody.Thistechniqueshould【63】improvetheefficiencyofcancerscreeningandsurveillancethescientistssaid.Cancerisoneofthebiggest【64】inindustrializedcountries.【65】tofiguresfromtheWorldHealthOrganization10millionpeoplewerediagnosedwiththediseaseworldwidein1997andsixmilliondied.
OnAntibodies Substancesforeigntothebodysuchasdisease-causingbacteriaandvirusesandotherinfectiousagentsarerecognizedbythebodysimmunesystemasinvaders.Ournaturaldefensesagainsttheseinfectiousagentsareantibodiesproteinsthatseekouttheantigens抗原andhelpdestroythem. Antibodieshavetwoveryusefulcharacteristics.Firsttheyareextremelyspecific;thatiseachantibodybindstoandattacksoneparticularantigen.Secondsomeantibodiesonceactivatedbytheoccurrenceofadiseasecontinuetoconferresistanceagainstthatdisease.Classicexamplearetheantibodiestothechildhooddiseasesofchickenpox水痘andmeasles. Thesecondcharacteristicofantibodiesmakesitpossibletodevelopvaccines.Avaccine痘苗isapreparationofkilledorweakenedbacteriaorvirusesthatwhenintroducedintothebodystimulatestheproductionofantibodiesagainsttheantigensitcontains. Itisthefirsttraitofantibodiestheirspecificitythatmakesmonoclonalantibodytechnologysovaluable.Notonlycanantibodiesbeusedtherapeutically在治疗上toprotectagainstdisease;theycanalsohelpto.diagnoseawidevarietyofillnessesandcandetectthepresenceofdrugsviralandbacterialproductsandotherunusualorabnormalsubstancesintheblood. Givensuchadiversityofusesforthesediseased-fightingsubstancestheirproductioninpurequantitieshaslongbeenthefocusofscientificinvestigation.Theconventionalmethodwastoinjectalaboratoryanimalwithanantigenandthenafterantibodieshadbeenformedcollectthoseantibodiesfromthebloodserum血清Antibodycontainingbloodserumiscalledantiserum抗血清.Therearetwoproblemswiththismethod:Ityieldsantiserumthatcontainsundesiredsubstancesanditprovidesaverysmallamountofusableantibody. Monoclonalantibodytechnologyallowsustoproducelargeamountsofpureantibodies.inthefollowingway:wecanobtaincellsthatproduceantibodiesnaturally;wealsohaveavailableaclassofcellsthatcangrowcontinuallyincellculture培养.Ifweformahybrid混血儿thatcombinesthecharacteristicofimmortality永生withtheabilitytoproducethedesiredsubstancewewouldhaveineffectafactorytoproduceantibodiesthatworkaroundtheclock. Inmonoclonalantibodytechnologytumorcellsthatcanreplicate重复endlesslyarefusedwithmammaliancellsthatproduceanantibody.Theresultofthiscellfusionisahybridoma杂交瘤whichwillcontinuallyproduceantibodies.Theseantibodiesarecalledmonoclonalbecausetheycomefromonlyonetypeofcellthehybridomacell;antibodiesproducedbyconventionalmethodsontheotherhandarederivedfrompreparationscontainingmanykindsofcellsandhencearecalledpolyclonal.Anexampleofhowmonoclonalantibodiesarederivedisdescribedbelow. Amyelomaisatumorofthebonemarrow骨髓thatcanbeadaptedtogrowpermanendyincellculture.Whenmyelomacellswerefusedwithantibody-producingmammalianspleencellsitwasfoundthattheresultinghybridcellsorhybridomasproducedlargeamountsofmonoclonal骨髓瘤antibody.Thisproductofcellfusioncombinedthedesiredqualitiesofthetwodifferenttypesofcells:theabilitytogrowcontinuallyandtheabilitytoproducelargeamountsofpureantibody. Becauseselectedhybridcellsproduceonlyonespecificantibodytheyaremorepurethanthepolyclonalantibodiesproducedbyconventionaltechniques.Theyarepotentiallymoreeffectivethanconventionaldrugsinfightingdiseasesincedrugsattacknotonlytheforeignsubstancebutthebody’sowncellsaswellsometimesproducingundesirablesideeffectssuchasnausea恶心andallergicreactions.Monoclonalantibodiesattackthetargetmoleculeandonlythetargetmoleculewithnoorgreatlydiminishedsideeffects. WhichofthefollowingfunctionsdoneNOTbelongtoantibodies?
Itshardtoalteroneshabits.
NewTechniquePromisesEarlierCancerDetection AnewtechniquecouldrevolutionizetheearlydetectionofcancergivingsufferersagreaterchanceofbeatingthediseaseAmericanscientistssaid.ResearchersattheMassachusettsInstituteofTechnologyhavedevisedanovelmethodof【51】changesinthenucleusofcellsintheearlieststagesofthedisease.Morethan85percentofallcancersoriginateintheepithelium上皮thatlinestheinternalsurfacesoforgans【52】thebody.Althoughthesearetreatable【53】theyarediagnosedinoneofthepreventablestagesearlybodydamagesarealmost【54】todetectsaidscientistFeld.Wepresentanewoptical-probe光学探子techniquebasedonlight-scatteringspectroscopy分光镜检查thatisable【55】detectprecancerousandearlycancerouscellsincell-richepitheliaheaddedinastatement. Thenewtechniquereliesonthefact【56】cellnucleichangeintheearlystagesofcancerandthedifferencesscatterlightinacharacteristicway.Untilnowthechangeswereonlydetectable【57】abiopsy活检wastakenthescientistssaid.Thenewtechnique【58】inthesciencejournalNaturecanbeusedinconjunctionwitharoutinecancerscreeningandsurveillancetechniquewhichusesanendoscope内窥镜—aflexibleopticalprobe【59】withcameraswhichisinsertedintoacavityinthebody—tocheck【60】cancers. Thescientistssaidthey【61】theirnewtechniqueinfourdifferentorgansduringroutineendoscopiccancerscreening.Thetipoftheopticalprobewasbroughtintocontactwiththetissuetobetestedandthescatteringoflightwasrecordedwithouttheneedforanytissuetobe【62】thescientistssaid.Ourresultsshowthatlight-scatteringspectroscopyhasthepotentialtodetectpre-cancerousbodydamagesandpreinvasivecancersthroughoutthebody.Thistechniqueshould【63】improvetheefficiencyofcancerscreeningandsurveillancethescientistssaid.Cancerisoneofthebiggest【64】inindustrializedcountries.【65】tofiguresfromtheWorldHealthOrganization10millionpeoplewerediagnosedwiththediseaseworldwidein1997andsixmilliondied.
Biotechnology Biotechnologyinoneformoranotherhasflourishedsinceprehistorictimes.Whenthefirsthumanbeingsrealizedthattheycouldplanttheirowncropsandbreedtheirownanimalstheylearnedtousebiotechnology.Thediscoverythatfruitjuicesfermented发酵inwineorthatmilkcouldbeconvertedintocheeseoryogurt酸乳酶orthatbeercouldbemadebyfermentingsolutionsofmalt麦芽andhops啤酒花beganthestudyofbiotechnology.Whenthefirstbakersfoundthattheycouldmakeasoftspongy多乳的breadratherthanafirmthincrackertheywe’’reactingasfledgling缺乏经验的biotechnologists.Thefirstanimalbreedersrealizingthatdifferentphysicaltraitscouldbeeithermagnifiedorlostbymatingappropriatepairsofanimalsengagedinthemanipulationsofbiotechnology. Whatthenisbiotechnology?Thetermbringstominddifferentthings.Somethinkofdevelopingnewtypesofanimals.Othersdreamofalmostunlimitedsourcesofhumantherapeutic治疗的drugs.Stillothersenvision想象thepossibilityofgrowingcropsthataremorenutritious有养分的andnaturallypest-resistant有抵抗力的tofeedarapidlygrowingworldpopulation.Thisquestionelicits引发almostasmanyfirst-thoughtresponsesastherearepeopletowhomthequestioncanbeposed.Initspurestformthetermbiotechnologyreferstotheuseoflivingorganismsortheirproductstomodifyhumanhealthandthehumanenvironment.Prehistoricbiotechnologistsdidthisastheyusedyeastcellstoraisebreaddough生面团andtofermentalcoholicbeveragesandbacterialcellstomakecheesesandyogurtsandastheybredtheirstrongproductiveanimalstomakeevenstrongerandmoreproductiveoffspring.Throughouthumanhistorywehavelearnedagreatdealaboutthedifferentorganismsthatourancestorsusedsoeffectively.Themarkedincreaseinourunderstandingoftheseorganismsandtheircellproductsgainsustheabilitytocontrolthemanyfunctionsofvariouscellsandorganisms.Usingthetechniquesofgenesplicing叠接andrecombineDNAtechnologywecannowactuallycombinethegeneticelementsoftwoormorelivingcells.FunctioninglengthsofDNAcanbetakenfromoneorganismandplacedintothecellsofanotherorganism.Asaresultforexamplewecancausebacterialcellstoproducehumanmoleculescowscanproducemoremilkorthesameamountoffeedandwecansynthesizetherapeuticmoleculesthathaveneverbeforeexisted. AccordingtothepassagewhichofthefollowingisNOTanapplicationofbiotechnology?
TheFunctionofTomatoes Howdowelovetomatoes?Let’’scounttheways:welovetheminpastaonpizzainjuiceinsaladandsoupslicedonsandwichesstuffedwithtunaevendriedandbakedinbagelsbutmostofallwelovethemrightoffvine—riperedanddelicious. Whiletomatoloversdon’’tneedanexcuseforeatingthembythebushel蒲式耳nowthere’’sevenmorereasontosavorthesedeliciousfruits.Evidenceismountingthatpeoplewhoeattomatoeshaveasubstantiallylowerriskforcancer. Inathousand-personstudyofeatinghabitsandhealthHarvardMedicalSchoolresearchersfoundthatthosewhoatetomatoeseveryweekhadthelowestchanceofdyingformcancer. Recentlyastudyof48000Americanmenshoweda21to34percentlowerriskforprostatecancer前列腺癌amongthosewhoconsumedtomatoestomatosauceorpizzamorethantwiceaweek.AndinstudyofmenandwomeninItalyeatingsevenormoreservingofrawtomatoesaweekwaslinkedtoa30to60percentreductionindigestivetractandprostatecancersdependingonthetypeofcancer. Theprotectivequalitiesofthetomatoarethoughttocomefromlycopene番茄红素apotentantioxidant抗氧化的plantchemicalthatisabundantintomatoes.Lycopeneisresponsiblefortheredcoloroftomatoes;thedarkerredthetomatoisthemorelycopeneitcontains.Greenandyellowtomatoesdonotcontainlycopene. Lycopoeneisalsofoundinwatermelonandpinkgrapefruitbuttomatoesarethemostabundantsource.Cookingenhancesthelycopenemoreavailable.Thustomatosauceandpasteisevenabettersourceforlycopenethanfreshrawtomatoes.Lycopeneisfatsolubleandmustbeconsumedwithacertainamountoffattobeabsorbedbythebody.Tomatorecipesmustcontainamoderateamountofoiltoensurethatalongwithadelicioustastetreatyouwillalsobereceivingallthehealthbenefitstomatoeshavetooffer. Whatisthemainsubjectofthepassage?
Biotechnology Biotechnologyinoneformoranotherhasflourishedsinceprehistorictimes.Whenthefirsthumanbeingsrealizedthattheycouldplanttheirowncropsandbreedtheirownanimalstheylearnedtousebiotechnology.Thediscoverythatfruitjuicesfermented发酵inwineorthatmilkcouldbeconvertedintocheeseoryogurt酸乳酶orthatbeercouldbemadebyfermentingsolutionsofmalt麦芽andhops啤酒花beganthestudyofbiotechnology.Whenthefirstbakersfoundthattheycouldmakeasoftspongy多乳的breadratherthanafirmthincrackertheywe’’reactingasfledgling缺乏经验的biotechnologists.Thefirstanimalbreedersrealizingthatdifferentphysicaltraitscouldbeeithermagnifiedorlostbymatingappropriatepairsofanimalsengagedinthemanipulationsofbiotechnology. Whatthenisbiotechnology?Thetermbringstominddifferentthings.Somethinkofdevelopingnewtypesofanimals.Othersdreamofalmostunlimitedsourcesofhumantherapeutic治疗的drugs.Stillothersenvision想象thepossibilityofgrowingcropsthataremorenutritious有养分的andnaturallypest-resistant有抵抗力的tofeedarapidlygrowingworldpopulation.Thisquestionelicits引发almostasmanyfirst-thoughtresponsesastherearepeopletowhomthequestioncanbeposed.Initspurestformthetermbiotechnologyreferstotheuseoflivingorganismsortheirproductstomodifyhumanhealthandthehumanenvironment.Prehistoricbiotechnologistsdidthisastheyusedyeastcellstoraisebreaddough生面团andtofermentalcoholicbeveragesandbacterialcellstomakecheesesandyogurtsandastheybredtheirstrongproductiveanimalstomakeevenstrongerandmoreproductiveoffspring.Throughouthumanhistorywehavelearnedagreatdealaboutthedifferentorganismsthatourancestorsusedsoeffectively.Themarkedincreaseinourunderstandingoftheseorganismsandtheircellproductsgainsustheabilitytocontrolthemanyfunctionsofvariouscellsandorganisms.Usingthetechniquesofgenesplicing叠接andrecombineDNAtechnologywecannowactuallycombinethegeneticelementsoftwoormorelivingcells.FunctioninglengthsofDNAcanbetakenfromoneorganismandplacedintothecellsofanotherorganism.Asaresultforexamplewecancausebacterialcellstoproducehumanmoleculescowscanproducemoremilkorthesameamountoffeedandwecansynthesizetherapeuticmoleculesthathaveneverbeforeexisted. ThesentenceThisquestionelicits...para.2means______.
NaturalMedicines Sinceearliestdayshumanshaveusedsomekindsofmedicines.Weknowthisbecausehumanshavesurvived.Ancienttreatmentsforinjuryanddiseaseweresuccessfulenoughtokeephumansfromdyingoutcompletely. Theyweresuccessfullongbeforethetimeofmodernmedicine.Beforethetimeofdoctorswithwhitecoatsandshiny发亮的instruments.Beforethetimeofbighospitalswithstrangeandwonderfulequipment. Manypartsoftheworldstilldonothaveuniversity-educateddoctors.Nordotheyhaveexpensivehospitals.Yetinjuriesaretreated.Anddiseasesareoftencured.How?Byancientmethods.Bymedicinesthatmightseemmysteriousevenmagical有魔力的.Traditionalmedicinesareneithermysteriousnormagicalhowever. Throughthecenturiestribal部落的medicinemenexperimentedwithplants.Theyfoundmanyusefulchemicalsintheplants.Andscientistsbelievemanyofthesetraditionalmedicinesmayprovidethecureforsomeoftoday’’smostseriousdiseases. Expertssayalmost80%ofthepeopleintheworlduseplantsforhealthcare.Thesenaturalmedicinesareusednotjustbecausepeoplehavenootherformoftreatment.Theyareusedbecausepeopletrustthem.Indevelopedareasfewpeoplethinkaboutthesourceofthemedicinestheybuyinastore.Yetmanywidely-usedmedicinesarefromancientsourcesespeciallyplants.Someexpertssaymorethan25%ofmodernmedicinescomeinonewayoranotherfromnature. Scientistshavelongknownthatnatureisreallyachemicalfactory.Alllivingthingscontainchemicalsthathelpthemsurvive.Soscientists’interestintraditionalmedicineisnotnew.Butithasbecomeanurgentconcern.Thisisbecausetheearth’’ssupplyofnaturalmedicinesmaybedroppingrapidly. WhichofthefollowingstatementsisNOTtrue?
TheFunctionofTomatoes Howdowelovetomatoes?Let’’scounttheways:welovetheminpastaonpizzainjuiceinsaladandsoupslicedonsandwichesstuffedwithtunaevendriedandbakedinbagelsbutmostofallwelovethemrightoffvine—riperedanddelicious. Whiletomatoloversdon’’tneedanexcuseforeatingthembythebushel蒲式耳nowthere’’sevenmorereasontosavorthesedeliciousfruits.Evidenceismountingthatpeoplewhoeattomatoeshaveasubstantiallylowerriskforcancer. Inathousand-personstudyofeatinghabitsandhealthHarvardMedicalSchoolresearchersfoundthatthosewhoatetomatoeseveryweekhadthelowestchanceofdyingformcancer. Recentlyastudyof48000Americanmenshoweda21to34percentlowerriskforprostatecancer前列腺癌amongthosewhoconsumedtomatoestomatosauceorpizzamorethantwiceaweek.AndinstudyofmenandwomeninItalyeatingsevenormoreservingofrawtomatoesaweekwaslinkedtoa30to60percentreductionindigestivetractandprostatecancersdependingonthetypeofcancer. Theprotectivequalitiesofthetomatoarethoughttocomefromlycopene番茄红素apotentantioxidant抗氧化的plantchemicalthatisabundantintomatoes.Lycopeneisresponsiblefortheredcoloroftomatoes;thedarkerredthetomatoisthemorelycopeneitcontains.Greenandyellowtomatoesdonotcontainlycopene. Lycopoeneisalsofoundinwatermelonandpinkgrapefruitbuttomatoesarethemostabundantsource.Cookingenhancesthelycopenemoreavailable.Thustomatosauceandpasteisevenabettersourceforlycopenethanfreshrawtomatoes.Lycopeneisfatsolubleandmustbeconsumedwithacertainamountoffattobeabsorbedbythebody.Tomatorecipesmustcontainamoderateamountofoiltoensurethatalongwithadelicioustastetreatyouwillalsobereceivingallthehealthbenefitstomatoeshavetooffer. Accordingtothepassageitisshowed______lowerriskforprostatecanceramongthosewhoconsumedtomatoesmorethanonceaday.
NewTechniquePromisesEarlierCancerDetection AnewtechniquecouldrevolutionizetheearlydetectionofcancergivingsufferersagreaterchanceofbeatingthediseaseAmericanscientistssaid.ResearchersattheMassachusettsInstituteofTechnologyhavedevisedanovelmethodof【51】changesinthenucleusofcellsintheearlieststagesofthedisease.Morethan85percentofallcancersoriginateintheepithelium上皮thatlinestheinternalsurfacesoforgans【52】thebody.Althoughthesearetreatable【53】theyarediagnosedinoneofthepreventablestagesearlybodydamagesarealmost【54】todetectsaidscientistFeld.Wepresentanewoptical-probe光学探子techniquebasedonlight-scatteringspectroscopy分光镜检查thatisable【55】detectprecancerousandearlycancerouscellsincell-richepitheliaheaddedinastatement. Thenewtechniquereliesonthefact【56】cellnucleichangeintheearlystagesofcancerandthedifferencesscatterlightinacharacteristicway.Untilnowthechangeswereonlydetectable【57】abiopsy活检wastakenthescientistssaid.Thenewtechnique【58】inthesciencejournalNaturecanbeusedinconjunctionwitharoutinecancerscreeningandsurveillancetechniquewhichusesanendoscope内窥镜—aflexibleopticalprobe【59】withcameraswhichisinsertedintoacavityinthebody—tocheck【60】cancers. Thescientistssaidthey【61】theirnewtechniqueinfourdifferentorgansduringroutineendoscopiccancerscreening.Thetipoftheopticalprobewasbroughtintocontactwiththetissuetobetestedandthescatteringoflightwasrecordedwithouttheneedforanytissuetobe【62】thescientistssaid.Ourresultsshowthatlight-scatteringspectroscopyhasthepotentialtodetectpre-cancerousbodydamagesandpreinvasivecancersthroughoutthebody.Thistechniqueshould【63】improvetheefficiencyofcancerscreeningandsurveillancethescientistssaid.Cancerisoneofthebiggest【64】inindustrializedcountries.【65】tofiguresfromtheWorldHealthOrganization10millionpeoplewerediagnosedwiththediseaseworldwidein1997andsixmilliondied.
OntheTrain ThenighttrainfromGlasgowwassocrowdedthatDonaldwhowasonhiswaytoLondontofindatemporaryjobfortheuniversityvacationwishedthathehaddecidedtotravelbyday.Hehadneverbeensohardup. Hegotonthetrainandwalkedalongthecorridorofthesecond-classcompartments.Hecouldn’’tfindaseatanywhere.Hecouldnotaffordtotravelfirstclassandhedidnotwanttostandinthecorridor.Neitherdidhewanttositonhissuitcase.Hewassotiredthathedecidedtositdowninafirstclasscompartmentatleastforawhile.Hesoonfoundonewithasingleoccupant乘客agentlemanreadingdocumentsfromabriefcase.Withtheself-assuranceofafirstclasstravelerheopenedthedoorandwentin.Nosoonerhadhesatdownthantheticketinspectorarrived.Whatbadluck!Nowhewouldhavetopaytheexcess额外的fare.Asheturnedouthispockettofindenoughmoneyhesawthegentlemanwaswatchinghimwithamusement.Itwashumiliating令人感到羞辱的.Howeverhewassotiredthathesoonfellasleep. Presentlyhearinganoisehehalfopenedhiseyes.Notonlydidhenoticethathistravelingcompanionhadgonebuthealsosawthatarough-lookingmanwassearchingthroughthebusinessman’’sbriefcase.Donaldgrabbedthebriefcaseandwrenched猛夺itfreekickingattheman’’sleg.Themanfled. ThenthebusinessmanreturnedandfoundDonaldholdingthebriefcaseandpeeringinsideit.Donaldrealizedthathewasinquiteanawkwardsituationbutthemanwassmiling.Norwasthistheonlysurprisingthing.NotonlywasthegentlemanwhointroducedhimselfasMr.SmithsmilingbuthethankedDonaldwarmly.OnhiswaybacktothecompartmentMr.Smithhadseenthemanleavinginagreathurry.HehadsoquicklyassessedthesituationthatheknewDonaldwasinnocent. OnlyafteralongchatinwhichDonaldwasaskedmanyquestionsabouthimselfdidDonalddiscoverthatMr.SmithwasinfactmanagingdirectorofalargefactoryinLondon.DonaldhadneverimaginedthatthisstrangeincidentwouldhelphimtofindajobbutjustastheywereleavingthetrainMr.SmithofferedhimthepostoftemporaryNightSecurityOfficerforhisfactory. Mr.SmithrealizedthatDonaldwasinnocent______.
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