英語寫作：如何寫好引言

HowtoWritetheIntroductionS1020489王華斌S1010133陳方城S1010104張李巧Thispptconcludes:definitionandpurpose(定義)rulesforagoodIntrodutionandsomeexceptions(好的引言的原則和例外).reasonsfortherules(原則的解釋).tense(時態(tài)).people(人稱).citationandabbreviations(引用和縮寫).definitionandpurposeThefirstsectionofthetextSupplysufficientbackgroundinformation(背景知識)toallowthereadertounderstandandevaluatetheresultsofthepresentstudyPrevioustherationale(原理)

forthepresentstudyandyourpurpose(目的)

inwritingthepaper.RulesforagoodIntrodutionpresentfirst,withallpossibleclarity,thenatureandscopeoftheprobleminvestigated(主題).Brieflyreviewthepertinentliteraturetoorientthereader(背景).Statethemethodoftheinvestigation.ifdeemednecessary,thereasonsforthechoiceofaparticularmethodshouldbestated(方法和原因).Statetheprincipalresultsoftheinvestigation(結(jié)果).Statetheprincipalcnclusionsofsuggestedbytheresults(結(jié)論).Example

Thebloodbrainbarrier(BBB)formedbytightendothelialcelljunctionsofbraincapillarypreventsalargenumberoftherapeuticcompoundsfromcentralnervoussystem(CNS),includingantibiotics,antineoplasticagentsandCNSactivedrugs.

Methotrexate(MTX)isapromisingantitumordrug.Unfortunately,itisverydifficultforMTXtopenetrateBBBsothattheadministrationofintrathecalinjectionisemployedinclinicaltreatmentforbraintumors.However,thisroutesubjectspatientstooperationwoundsandhighrisks.介紹研究領(lǐng)域及其一般進展，提供背景資料背景：以前研究中存在的問題ExampleSeveralpharmaceuticalmethodshavebeentriedtoovercomeBBB.First,drugswithproperchemicalstructurescanbemodifiedtoenhancebrainuptakeusuallybyintroductionoflipophilicgroups.Besides,anovelchemicaldeliverysystemhasalsodeveloped(Yoshikawaetal.,1999).However,thisstrategyislargelylimitedbythechemicalstructureofcompounds.Atthesametime,alargenumberoflipophiliccompoundsthatcanpassthroughBBBarerapidlypumpedbackintobloodstreambymulti-drugresistanceproteins(MRPs)includingmultipleorganicaniontransporter(MRP2)andP-glycoprotein(Pgp).Theexistenceofsucheffluxpumpsprovestobeanotherlimitationtothismethod.Second,stericallystabilizedimmunoliposomesareusedforbothchemicaldrugsandgenesdeliverytobrain(Huwyleretal.,1996;ShiandPardridge,2000).However,humanderivedantibodyistooexpensiveandtheefficacyofsuchtechnologyisnotremarkable.文獻回顧：一直在研究的相關(guān)的藥理方法兩個However指出仍然需要研究的地方ExampleTheobjectiveofthepresentstudywastodeterminewhetherthesizeofnanoparticleshadanyinfluenceonbraintargeting.Noexperimentsconcerningthisaspecthavebeenreported.PBCAnanoparticleswithdifferentsizecouldbepreparedbyadjustingthepolymerizationconditionssuchasmediapH,concentrationofemulsifierandmonomerplusstirringrate.MTXwasusedasthemodeldrugsandinvivoexperimentswerecarriedouttoobtainsomepharmacokineticresults.介紹作者研究目的和活動：PBCA納米質(zhì)粒研究選擇特定方法和選擇的原因：用MTX做對照藥物Reasonsfortherules

ThefirstruleisthecardinaloneIftheproblemisnotstatedinareasonable,understandableway,readerwillhavenointerestinyoursolution(簡明扼要的介紹你的主題).Key:whydidyouchoosethatsubject,andwhyisitimportant?ReasonsfortherulesThesecond(literaturereview)andthird(choiceofmetheod)rulesralatetothefirst(背景和方法).Key:MakereaderunderstandwhattheproblemwasandhowyoutriedtoresolveReasonsfortherulesThestatementofprincipalresultsandconclusions——thecapstoneoftheIntroduction(介紹結(jié)果和結(jié)論很重要)AbitofredundancywiththeabstractisoftendesirableThemistaketheauthorsmaymake:Holdingbacktheirmoreimportantfindingsuntillateinthepaper.(引言中不提重要的發(fā)現(xiàn)，而放到論文最后)

“Rendingascientificarticleisn’tthesameasreadingadetectivestory.Wewanttoknowformthestart”(Ratnoff,1981).SomeexceptionInsomereseachareasandjournals,scientificpapersfollowonlythefirstthreerulesKey:lookingatpapersinyourtargetjournalasmodelsSomeexceptionSomefields,theIntroductionhasa“funnel”shape(漏斗狀結(jié)構(gòu)，先介紹大的背景，再介紹小的研究方向).

優(yōu)點：Aintroductionthusstructuredcanprovideahelpfulandhospitablewelcome(給讀者幫助性的和“好客”的態(tài)度).tense

MuchoftheIntroductionshouldbewritteninpresenttense,becauseyouwillberefferringtoyourproblemandtheestablishedknowledge(一般現(xiàn)在時為主).可以適當(dāng)用過去時描述前人已經(jīng)做過的工作，用現(xiàn)在完成時描述一直持續(xù)到現(xiàn)在的工作或研究程度。tensetensetense

Gurkovskayaetal.(2009)foundthattheneuroactivesteroiddehydroepiandrosterone(DHEA)candosedependentlydecreasevoluntaryintakeofethanolinmalerats.Inthatstudy,subjectstrainedtoconsumeethanolreceiveddosesoftheneuroactivesteroidspregnanoloneandDHEAtocomparetheireffectsonethanolconsumption.ThatstudyshowedthatDHEAdecreasedethanolintakemoreeffectivelythanpregnanolone.DHEAproducesawidearrayofphysiologicaleffects,acharacteristicthatmakesdeterminingthespecificmechanismbywhichitaltersethanolintakedifficult.Forinstance,DHEAisaprecursorforestradiolandtestosteroneinperipheraltissues(Lardyetal.,2005)andhasintrinsicandrogenicactivity(Moetal.,2006).DHEAisalsoanegativeallostericmodulatoroftheGABAAreceptorcomplex(Majewskaetal.,1990)thatcanincreasethelevelsofotherneuroactivesteroidsthatmodulatethisreceptor,suchasallopregnanolone(Bernardietal.,2005).ThefactthatDHEAcanserveasaprecursorforestradiolandtestosteroneinperipheraltissuesmaybeproblematicforitsuseinaclinicalsetting(Lardyetal.,2005).AdministrationofexogenousDHEAhasbeenfoundtocauseacne,hirsutism,andalteredmensesinwomenbecauseofitscapacityforincreasingtestosteronelevels(vanVollenhovenetal.,1999;PanjariandDavis,2007).Furthermore,alterationsinthelevelsofsexsteroidshavebeenreportedtoaffectethanolconsumption(LakozaandBarkov,1980;Juarezetal.,2002).Thepresentstudycomparedtheeffectsof3b-acetoxyandrost-5-ene-7,17-dione(7-ketoDHEA)onethanolintakewiththeeffectsofDHEAreportedpreviouslyinthesamegroupofrats(Gurkovskayaetal.,2009).7-ketoDHEAisametaboliteofDHEAthatisnotconvertedtosexhormones(Lardyetal.,1998).7-ketoDHEAistheacetylesterof7-oxoDHEA,anaturallyoccurringmetabolite

ofDHEA(seeFig.1).Invivo,widespreadtissueesteraseshydrolyze7-ketoDHEAtofree7-oxoDHEA(Lund-Peroetal.,1994).person適當(dāng)?shù)厥褂谩癐”，“We”或“Our”,“Thispaper”等詞,以明確地指示作者本人的工作;如：——Weconductedthisstudytodeterminewhether…(Thisstudywasconductedtodeterminewhether…);——Thispaperwillpresent(presents)anewapproachthatprocessthedatamoreefficiently.(Insummary,previousmethodsareallextremelyinefficient.Henceanewapproachisdevelopedtoprocessthedatamoreefficiently.)Citationandabbreviati