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500 个结果
  • 简介:在忍冬装饰用的梨树花的di-O-caffeoylquinic酸(diCQAs)的三种类型的抗菌剂活动,繁体中文药(TCM),在杆菌shigae上,生长被microcalorimetry调查并且比较。diCQAs的三种类型是3,4-di-O-caffeoylquinic酸(3,4-diCQA),3,5-di-O-caffeoylquinic酸(3,5-diCQA),并且4,5-di-O-caffeoylquinic酸(4,5-diCQA)。新陈代谢的力量时间上的三diCQAs的效果的质、量的信息弄弯的一些,生长率常数k,最大的热产量力量下午,和产生预定tG,全部的热产量Qt,和生长禁止的比率我B。shigae是计算的。根据一个thermo运动的模型,k,下午,Qt,我和c的相应量的关系被建立。另外,这些药(IC50)的一半禁止的集中被定量分析获得。基于数量活动关系和IC50价值,禁止的活动的顺序是3,5-diCQA>4,5-diCQA>3,4-diCQA。结果说明在C-5的caffeoyl酉旨组是为细菌的房间有一种更高的亲密关系的主要的组的可能性,并且二caffeoyl酉旨的intramolecular距离组织,这也在diCQAs的抗菌剂活动有重要影响。

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  • 简介:Accordingtotheconsiderationoftheadvantageofdrilling,itisusuallyakindofprac-ticethathelpsstudentstoacquirefluencyinthelanguagebytrainingthemtoproducelan-guagepatternsautomaticallyandwithoutconsciouseffort.Butinrecentyears,thereisagreatandheatedarguementaboutdrillingactivities.

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  • 简介:Thereare13papersinthisspecialissueonstressfield,crustaldeformationandseismicity.ThegreatWenchuanearthquakeisagrievousdisaster,butChinesescientistsaretryingtolearnmorefromtheeventinordertounderstandbetterthephysicsofearthquakesfor

  • 标签: 地震活动 应力场 应变 中国科学家 GPS技术 地壳形变
  • 简介:Magnetohydrodynamicsisoneofthemajordisciplinesinsolarphysics.Vigorousmagnetohydrodynamicprocessistakingplaceinthesolarconvectionzoneandatmosphere.Itcontrolsthegeneratingandstructuringofthesolarmagneticfields,causestheaccumulationofmagneticnon-potentialenergyinthesolaratmosphereandtriggerstheexplosivemagneticenergyrelease,manifestedasviolentsolarflaresandcoronalmassejections.Nowadaysdetailedobservationsinsolarastrophysicsfromspaceandonthegroundurgeagreatneedforthestudiesofmagnetohydrodynamicsandplasmaphysicstoachievebetterunderstandingofthemechanismormechanismsofsolaractivity.Ontheotherhand,thespectacularsolaractivityalwaysservesasagreatlaboratoryofmagnetohydrodynamics.Inthisarticle,wereviewedafewkeyunresolvedproblemsinsolaractivitystudiesanddiscussedtherelevantissuesinsolarmagnetohydrodynamics.

  • 标签: 太阳活动 日冕物质抛射 等离子体物理 太阳大气 太阳物理学 天体物理学
  • 简介:Tetradecyldimethylbenzylammoniumsalt(TDMBA)cationswereintercalatedintosodiummontmorillonite(Na-MMT)byanionexchangereaction.TheresultingTDMBA-MMTwascharacterizedbyFourier-transforminfraredspectroscopy(FTIR),thermogravimetricanalysis(TGA),andX-raydiffraction(XRD).Moreover,theantibacterialactivityandwater-resistanceofTDMBA-MMTwereinvestigated.TheresultsshowthatTDMBAcationsareintercalatedintotheNa-MMT.TheonsettemperatureofdecompositionofTDMBAcationsinTDMBA-MMTisraisedabout60℃higherthanthatoftetradecyldimethylbenzylammoniumchloride(TDMBACl),andthed_((001))spacingenlargedfrom1.23nmto2.10nm.0.1mg/mLTDMBA-MMTisfullyenoughtokillalltheStaphylococciaureus(S.aureus)andmorethan99.99%oftheEscherichiacoli(E.coli)inasamplesolutionwithin6.0htouch,andtheTDMBA-MMTalsoshowslongactingproperties.

  • 标签: 抗菌活性 金黄色葡萄球菌 石结构 傅立叶变换红外光谱 离子交换反应 钠蒙脱土
  • 简介:PreliminarystudyonthedurationofearthquakeactivityFu-MingHUANG(黄福明)(InstituteofCrustalDynamics,StateSeismologicalBureau,Beijin...

  • 标签: EARTHQUAKE ACTIVITY DURATION of SEISMIC ACTIVITY
  • 简介:Chronicdiseaseshavebecomeafocalpointofpublichealthworldwidewithestimatesoftrillionsofdollarsinannualhealthcarecostandcausingmorethan36milliondeathsayear.Lifestylefactorssuchasphysicalinactivityareheavilycorrelatedwiththedevelopmentofmanychronicdiseases.Newstrategiesforprimaryandsecondarydiseasepreventionaredesperatelyneededtoaidinbluntingthenegativeeconomicandsocialimpactofthesediseases.Physicalactivity(PA)andexercisearenowconsideredprincipalinterventionsforuseinprimaryandsecondarypreventionofchronicdiseases.Currently,moreemphasisinprimarypreventionofdiseaseisnecessarytoreducediseaseriskinyouthandadults;howeverwithchronicdiseaseprevalencesohigh,similaremphasisisalsonecessaryforsecondarypreventioninthosechildrenandadultsalreadyinflictedwithchronicdiseases.Conditionssuchascardiovasculardisease,type2diabetes,obesity,andcanceraredrasticallyimprovedwhenPAandexercisearepartofamedicalmanagementplan.Inaddition,thenationalPAguidelinesinconjunctionwithPApromotiontoolslikeExerciseisMedicine?areneededtopromoteincreasedPAandexerciselevelsworldwide.

  • 标签: 慢性疾病 体力 链接 心血管疾病 2型糖尿病 公众健康
  • 简介:ThispaperaimstopresentanexperimentdevelopedinatechnologydegreecollegeinS?oPaulo:thefreshmenintegrationandremedialclassesweek.Thisworkwasdevelopedduetothedropoutratethatoccurredinseveralcourses.The50%dropoutratewascollectedthroughasampleofthefirstsemesterfrom2012to2014.Thiscollegehascoursesinweldingtechnology,mechanicalmanufacturing,industrialautomationandrefrigeration,airconditioning,andventilationandheating.Itisapubliccollege.Astheyarecoursesoftheareaofmechanicalengineering,theirfirstsemestersconsistofcalculus,physics,chemistry,statistics,andotherdisciplinesthatrequiresolidknowledgebackgroundfromseniorhighschool.Thisisnottherealityfortheprofileofincomingstudents.Ninety-fivepercentofthestudentscomefrompublicschools.Remedialclassesweekiscomprisedofremedialclassesonmathematics,motivationallectures,presentationoftheacademic,andjobmarketarea,aswellasintegrationwithveteranstudents,teachers,andcoordinators.Thisworkbeganin2014andtherewas35%evasionreduction.

  • 标签: LEARNING EVASION technology DEGREE
  • 简介:Thesixmultiimidazolecopper(Ⅰ)complexesareutilizedtomimictyrosinase.Themainproductis3,5-di-t-butylcatecholfromo-hydroxylationofthesubstrate2,4-di-t-butylphenol.Thehighestyieldofcatecholisupto82.2%andselectivity94.8%by[Cu(I)_(3b)(MeCN)_2](ClO_4)_2andO_2undermildconditions,whicharefoundtobemoreefficientthanthatalreadyreported.

  • 标签: 复合物 o-羟基化作用 儿茶酚 酪氨酸酶
  • 简介:Anewmethacrylamidemonomer,hexylaminemethacrylamide(MAHA),wassynthesizedandusedinpolymerizations.ThehomopolymerofMAHAanditscopolymersweresynthesizedbyfreeradicalpolymerizationtechniqueswithN-isopropylacrylamide(NIPAAm)intwodifferentcompositions.Thequaternizationofthehomopolymerandcopolymerswerecarriedoutusing1-bromopropane.ThecopolymerswithNIPAAmandalowMAHAcontentshowedtemperature-responsivebehaviorinanaqueousenvironment.Thelowercriticalsolutiontemperatures(LCSTs)ofthesepolymersvariedbetween32℃and44℃.TheLCSTsofquaternizedcopolymerswerehigherthanthoseofneutralcopolymersbecausetheyweremorehydrophilic.TheobtainedhomopolymersandcopolymersweretestedforantibacterialactivitiesagainstS.aureusandE.coli.Thequaternizedwater-solublecopolymersshowedantibacterialactivitiesagainstS.aureus.Thequaternizationresultedinthesynthesisofbothantibacterialandtemperature-responsivecopolymers.

  • 标签: 丙烯酰胺聚合物 温度响应性 抗菌活性 水溶性共聚物 NIPAAM 异丙基丙烯酰胺