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

  • 标签: WNT信号通路 防护作用 癌症治疗 肠道上皮细胞 人类活动 放射治疗
  • 简介:InthearticletheauthorlooksbacktheharddevelopmentcourseandgreatprogressinearthquakescienceandtechnologyinChinaduringthelastnearahalfofcenturyandexpoundsthefollowing3aspects:(1)Thestrongdesireofthewholesocietytomitigateseismicdisastersandreducetheeffectofearthquakesonsocial-economicliveisagreatdrivingforcetopushforwardthedevelopmentofearthquakescienceandtechnologyinChina;(2)Tobetterensurepeople'slifeandproperty,sustainableeconomicdevelopment,andsocialstabilityisanessentialpurposetodrivethedevelopmentofearthquakescienceandtechnologyinChina;and(3)Toinsistonthedialecticalconnectionofsetupoftechnicalsystemforseismicmonitoringwiththescientificresearchofearthquakesandtobetterhandletherelationbetweencrucialtask,currentscientificlevel,andthefeasibilityaretheimportantprinciplestoadvancetheearthquakescienceandtechnologyinChina.Somesuccessandmanysetbacksinearthquakedisastermitigationconsistentlyenrichourknowledgeregardingthecomplexityoftheconditionsforearthquakeoccurrenceandtheprocessofearthquakepreparation,promotethereconstructionandmodernizationoftechnicalsystemforearthquakemonitoring,anddeepenthescientificresearchofearthquakes.Duringthelast5years,theimprovementandmodernizationoftechnicalsystemforearthquakemonitoringhaveclearlyprovidedthetechnicalsupporttostudyandpracticeofearthquakepredictionandprecaution,giveprominencetokeyproblemsandbroadenthefieldofscientificresearchofearthquakes.Thesehaveenabledustogetsomenewrecognitionoftheconditionsforearthquakeoccurrenceandprocessofearthquakepreparation,characteristicsofseismicdisaster,andmechanismforearthquakegenerationinChina'scontinent.Theprogresswehavemadenotonlyencouragesustoenhancetheeffectivenessofearthquakedisastermitigation,butalsoprovidesabasisforacceleratingfurtherdevelo

  • 标签: EARTHQUAKE Science and technology PROGRESS REVIEW
  • 简介:Basedontheinvestigationoftheluminescenceofaseriesofrareearthorganicchelates,somerelationshipsbetweenluminescenceandthestructureofthechelateswereproposed:theintensityofsensitizedluminescenceofcentrallanthanideions(Ln3+)inarareearthorganicchelatedependson(1)thesuitabilityoftheenergygapbetweentheexcitedtripletenergyleveloftheligandsandthelowestexcitedenergylevelofLn3+ions;(2)therigidityandplanarityofthestructureofthechelatemolecule;(3)theexistenceofasuitablesecondaryligandwhichmayincreaserigidityandthestabilityofthechelatemolecule;and(4)theexistenceofasuitableπ-conjugatedsysteminthechelatemolecule.Accordingtotheaboverelationships,25novelorganicligandsweredesignedandsynthesized,andtheirlanthanidechelateswereprepared.Investigationofthephotoluminescenceforthenewchelatesshowsthatsomeofthechelatesarestronglyluminescent,andareappliedtofluoroimmunoassayfordeterminationofhumanimmunoglobulin(IgG),topreparationoffluorescentplastics,andtodeterminationofgrowthhormoneforplants.Twonovelspectroscopy-probetechniquesforstructureofcoordinationcompoundsandbiologicalmoleculeswereproposedanddevelopedbasedonvibronicspectroscopyofTb3+complexesandfluorescenceofCe3+.

  • 标签: 稀土 螯合物 研究进展 发光
  • 简介:AbstractEtiology of adolescent idiopathic scoliosis (AIS), a complicated three-dimensional spinal deformity with early-onset, receives continuous attention but remains unclear. To gain an insight into AIS pathogenesis, this review searched PubMed database up to June 2019, using key words or medical subject headings terms including "adolescent idiopathic scoliosis," "scoliosis," "pathogenesis," "etiology," "genetics," "mesenchymal stem cells," and their combinations, summarized existing literatures and categorized the theories or hypothesis into nine aspects. These aspects include bone marrow mesenchymal stem cell studies, genetic studies, tissue analysis, spine biomechanics measurements, neurologic analysis, hormone studies, biochemical analysis, environmental factor analysis, and lifestyle explorations. These categories could be a guidance for further etiology or treatment researches to gain inspiration.

  • 标签: Scoliosis Pathogenesis Etiology Mesenchymal stem cells
  • 简介:Thispapersummarizes,fromaglobalperspective,themajorprogressintheimplementationoftheAgenda21sincetheUNConferenceonEnvironmentandDevelopment.Theresultsshowthatglobaleconomyhasachievedasubstantialgrowth,andpositiveprogresshasbeenmadeinpovertyeradication,urbanization,andconservationandintensiveuseofnaturalresources.However,relevantinternationalconventionsandcommitmentshavenotyetbeencompletelyfulfilled.Thepaperfurtheranalyzesthecurrentmajorchallengesandfuturetrendsofglobalsustainabledevelopment.Itisarguedthattherearethreemajorchallenges:1)fatalglobalenvironmentalissuesposinganincreasingthreattohumansurvival;2)moreandmoresevereglobalcompetitionfordevelopingspaces;and3)issueshighlightingglobalpeople'slivelihood.Therearefourtrendsofglobalsustainabledevelopment:1)sustainabledevelopmentwillfurtherturnfromconceptintoglobalaction;2)greenwillbethemaintrendofglobaldevelopment;3)emergingdevelopingcountrieswillbecomethemaindrivingforceofglobalsustainabledevelopment;and4)internationalrelationsinthefieldofsustainabledevelopmentwillturntocompetitiveco-operation.

  • 标签: 21世纪议程 发展趋势 全球可持续发展 环境问题 发展中国家 全球范围
  • 简介:ForewordRespectingandprotectinghumanrightsisaconstitutionalprincipleinChina.ItalsoreflectsthewillandpursuitoftheCommunistPartyofChina(CPC),theChinesegovernmentandtheChinesepeople.Thejudiciaryisthelastlineofdefensetosafeguardsocialfairnessandjustice,andjudicialprotectionofhumanrightsisanimportant

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  • 简介:Occlusaldisordercausedbysevereworndentitionisoneofthemostcommondiseasesintheocclusion.Occlusalreconstructionisanimportantrepairmethod,referringtomodifyandrebuildtheexistingocclusionstatus,thentorestoretheocclusion.Duringocclusalreconstruction,thedigitalocclusionanalysissystemcanaccuratelyacquiretheocclusionstatus,inordertoguidethereconstructionocclusionaccuratelyandrestorethenormalfunctionoftheoralmaxillarysystem.Thispaperreviewstheconceptofocclusalreconstruction,sequencetherapy,traditionalocclusionanalysismethodsandthedevelopmentstatusandprospectofdigitalocclusionanalysis.

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  • 简介:ForewordTheyear2003wasanimportantandunusualyearforChina’sdevelopment.Itwasalsoayearofgreat,landmarksignificanceforprogressinhumanrightsinthecountry.In2003,theChineseGovernmentdidagoodjobintacklingthesuddenoutbreakofSARSandcurbingitsspread,aswellasintacklingfrequentnaturaldisasters.Persistingintakingeconomicconstructionasitscentraltask,andstrivingfor

  • 标签: 山田 石山 棘器
  • 简介:Cancerisaleadingcauseofdeathworldwide.Cancertreatmentsbychemotherapeuticagents,surgery,andradiationhavenotbeenhighlyeffectiveinreducingtheincidenceofcancersandincreasingthesurvivalrateofcancerpatients.Inrecentyears,plant-derivedcompoundshaveattractedconsiderableattentionasalternativecancerremediesforenhancingcancerpreventionandtreatmentbecauseoftheirlowtoxicities,lowcosts,andlowsideeffects.Ellagicacid(EA)isanaturalphenolicconstituent.RecentinvitroandinvivoexperimentshaverevealedthatEAelicitsanticarcinogeniceffectsbyinhibitingtumorcellproliferation,inducingapoptosis,breakingDNAbindingtocarcinogens,blockingvirusinfection,anddisturbinginflammation,angiogenesis,anddrug-resistanceprocessesrequiredfortumorgrowthandmetastasis.ThisreviewenumeratestheanticarcinogenicactionsandmechanismsofEA.ItalsodiscussesfuturedirectionsontheapplicationsofEA.

  • 标签: 抗癌效果 鞣花酸 机制 癌症患者 放射治疗 DNA结合
  • 简介:Involuntaryresettlementcausedbyprojectconstructionisadifficultproblemovertheworld.Inthepast,therestorationoflivelihoodsintheeventofinvoluntaryresettlementhasbeenbasedpurelyonprovidingcompensationtothosewhoaredisplaced.Evidencehasshownthatcompensation-basedinvoluntaryresettlementcannotrealizetheobjectiveofrestoringandimprovingresettlers'livingstandard.Withaviewtoimprovethisoutcome,thecon-ceptofResettlementwithDevelopment(RwD)wasenvisagedandisnowgenerallyheraldedasthemeanstomitigatethecatastrophicfailuresofthepast.However,fewdevelopingcountrieshaveincludedtheconceptofRwDintotheirnationalpoliciesandChinaisoneofthem.TheChinesegovernmenthastakenresettlementasanopportunitytohelpresettlersrestoreandimprovetheirlivingstandardsanddevelopeconomyinreservoirareasbyimplementingRwDpolicyincludinggivingcompensationandsubsidiesatearlystageandofferingproductionassistanceatlatestage,settingupreservoirconstructionfund,initiatingpartnershipprogramsandpreferentialpolicyaswellasenhancinginfrastructureconstruction.ThepreliminaryexperiencefromtheTGPresettlementhasverifiedthatthetransformationfromcompensation-basedresettlementtoRwDisarightpolicychoice.Meanwhile,becauseofthechangingpoliticalenvironmentandthecomplexityofinvoluntaryresettlementthereisstillroomforChinatoimproveitsRwDpolicy.

  • 标签: 中国 生态经济 补偿安置 可持续发展
  • 简介:Ithasn’tbeeneasy,butalmostalloftheworkontheThreeGorgesProjectisonschedule,accordingtoacorporationoverseeingconstructionofthedam.TheChinaYangtzeThreeGorgesProjectDevelopmentCorporationhasreportedthatcontractorsandotherstaffareworkinghardtoensurethatthefloodseasondoesnotslowthedamproject.Thecompanyrecentlydetailedthemammothtasksthathavetakenplacesofar

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  • 简介:Permanentmagneticmaterialscapableofoperatingathightemperatureupto500°Chavewidepotentialapplicationsinfieldssuchasaeronautics,space,andelectroniccars.SmCoalloysarecandidatesforhightemperatureapplications,sincetheyhavelargemagnetocrystallineanisotropyfield(6–30T),highCurietemperature(720–920°C),andlargeenergyproduct([200kJám-3)atroomtemperature.However,thehighestservicetemperatureofcommercial2:17typeSmComagnetsisonly300°C,andmanyeffortshavebeendevotedtodevelopnovelhightemperaturepermanentmagnets.ThisreviewfocusesonthedevelopmentofthreekindsofSmCobasedmagnets:2:17typeSmComagnets,nanocrystallineSmComagnets,andnanocompositeSmComagnets.Theoxidationprotection,includingalloyingandsurfacemodification,ofhightemperaturepermanentmagnetsisdiscussedaswell.

  • 标签: 高温永磁材料 高温永磁体 钐钴合金 磁晶各向异性场 最高使用温度 纳米复合材料
  • 简介:Strategicenvironmentalassessment(SEA)inChinahasdevelopedrapidlysinceitwasintroducedintoChinainthe1990s.ChinesegovernmentpromulgatedtheEnvironmentalImpactAssessmentLawofChina(hereinafterreferredtoastheEIALaw)in2002.Inthislaw,itisstipulatedclearlythatregionalandsectorplansshouldbeassessed.Throughinvestigatingmaterialsandanalyzingliteratures,thisarticleanalysesthepracticalandacademicstudyachievementsofSEAinChinathathavebeenachievedsincetheEIALawwasimplemented,probesintothecurrentsituationofthemainlevelofSEAinChina-planEIA,thensummarizesthedevelopmentcharacteristics,andeventually,putsforwardthedevelopmenttrendsofSEAinChina.TheresearchconclusionscanofferthefoundationsforcomprehendingsystematicallytheprogressofSEAinChina.

  • 标签: 战略环境评价 中国海域 发展趋势 环境影响评价法 环境影响评估 海洋法
  • 简介:Inlinewiththerapidlyexpandingelectricpowerindustryinthiscountry,Chinanowownsaworkforcetotalingmorethanhalfamillionofstaffandworkersengagedintheconstructionofthermalpowerprojects;alsothetechnologyemployedintheirworkhasexperiencednotableprogress.Intheearlyfifties,constructionworkmainlyreliedonmanualmanipulation.Besidestheuseofhand-orelectric-drivenover-headcranesinsidethemachine-house,verticaltransporta-tiondependedmainlyonhoistersandpulleys;chainblockswerescarceatthattime.Horizontaltransportationwasmainlydonebymanualpulley-blocksandrollers,sometimesalsowithwinches.Electric-orgas-weldingbyhandwasthecommonprac-tice.Inaword,thetechnologywasbackwardandlabor-inten-

  • 标签: morethan EXPANDING engaged TOWER BACKWARD SOMETIMES