简介：AbstractBackground:Delivery room resuscitation assists preterm infants, especially extremely preterm infants (EPI) and extremely low birth weight infants (ELBWI), in breathing support, while it potentially exerts a negative impact on the lungs and outcomes of preterm infants. This study aimed to assess delivery room resuscitation and discharge outcomes of EPI and ELBWI in China.Methods:The clinical data of EPI (gestational age [GA] <28 weeks) and ELBWI (birth weight [BW] <1000 g), admitted within 72 h of birth in 33 neonatal intensive care units from five provinces and cities in North China between 2017 and 2018, were analyzed. The primary outcomes were delivery room resuscitation and risk factors for delivery room intubation (DRI). The secondary outcomes were survival rates, incidence of bronchopulmonary dysplasia (BPD), and risk factors for BPD.Results:A cohort of 952 preterm infants were enrolled. The incidence of DRI, chest compressions, and administration of epinephrine was 55.9% (532/952), 12.5% (119/952), and 7.0% (67/952), respectively. Multivariate analysis revealed that the risk factors for DRI were GA <28 weeks (odds ratio [OR], 3.147; 95% confidence interval [CI], 2.082-4.755), BW <1000 g (OR, 2.240; 95% CI, 1.606-3.125), and antepartum infection (OR, 1.429; 95% CI, 1.044-1.956). The survival rate was 65.9% (627/952) and was dependent on GA. The rate of BPD was 29.3% (181/627). Multivariate analysis showed that the risk factors for BPD were male (OR, 1.603; 95% CI, 1.061-2.424), DRI (OR, 2.094; 95% CI, 1.328-3.303), respiratory distress syndrome exposed to ≥2 doses of pulmonary surfactants (PS; OR, 2.700; 95% CI, 1.679-4.343), and mechanical ventilation ≥7 days (OR, 4.358; 95% CI, 2.777-6.837). However, a larger BW (OR, 0.998; 95% CI, 0.996-0.999), antenatal steroid (OR, 0.577; 95% CI, 0.379-0.880), and PS use in the delivery room (OR, 0.273; 95% CI, 0.160-0.467) were preventive factors for BPD (all P < 0.05).Conclusion:Improving delivery room resuscitation and management of respiratory complications are imperative during early management of the health of EPI and ELBWI.

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简介：AbstractIntroduction:Portal venous gas (PVG) is common in necrotizing enterocolitis and occasionally occurs in neonates after umbilical vein catheterization (UVC). Therefore, determining the cause of PVG requires further clinical evaluation in these cases.Case presentation:We report the case of a very-low-birth-weight infant who underwent UVC after birth. PVG was an unexpected finding on ultrasound following catheterization. The UVC was immediately removed and replaced with a peripherally inserted central catheter. The infant’s physical examination was unremarkable. Bedside X-ray revealed neither PVG nor pneumatosis intestinalis, which would indicate the onset of necrotizing enterocolitis. After full evaluation, breastfeeding was started on the same day. The infant did not develop feeding intolerance, necrotizing enterocolitis, or other disorders.Conclusion:PVG occasionally occurs in neonates who undergo UVC and is considered to be caused by exogenous gases. PVG is more easily detected with ultrasound than with X-ray and does not affect early feeding in premature infants.

简介：Theself-assembledInAs/GaAsquantumdots(QDs)withextremelylowdensityof8×10~6cm~(-1)areachievedusinghighergrowthtemperatureandlowerInAscoveragebylow-pressuremetal-organicchemicalvapourdeposition(MOVCD).Asaresultofmicro-photoluminescence(micro-PL),forextremelylowdensityof8×10~6cm~(-1)InAsQDsinthemicro-PLmeasurementsat10K,onlyoneemissionpeakhasbeenachieved.ItisbelievedthattheInAsQDshaveagoodpotentialtorealizesinglephotonsources.

简介：ObjectiveToassesstheutilityoflow-andhigh-frequencytympanometryinthediagnosisofmiddleeardysfunctioninChineseinfants.MethodsTympanogramswereobtainedwith226Hz,678Hzand1000Hzprobetonesfrominfantsaged5-25weekswithnormalauditorybrainstemresponses(ABRs)(15infants,30ears)andwithprolongedwaveIlatencies(17infants,20ears),suggestingmiddleeardysfunction,usingaGSITympstarmiddleearanalyzerVersionII.ResultsThesingle-peakedtympanogramwasthemostcharacteristictypeinbothgroupsandseenin25ears(83.3%)inthenormalABRgroupandin18ears(90%)inthedelayedwaveIgroup,respectively.Thepeakpressure,peakcompensatedstaticacousticadmittanceandgradientof226Hztympanometrywereofnosignificantdifferencesbetweenthetwogroups.The678Hztympanogramsofadmittance,susceptanceandconductancedemonstratednon-peak,single-,double-andtri-peakedpatternsinbothgroups.TheagreementbetweenABRsand678Hztympanogramsofadmittance,susceptanceandconductancewere70.0%,58.0%and64.0%(kappa=0.324,0.234and0.118)respectively.For1000Hzprobetone,admittance,susceptanceandconductancetympanogramsshowedsinglepeakedpatternsin28(93.3%),25(83.3%)and26(86.7%)ofthe30normalears.Admittance,susceptanceandconductancetympanogramsusingthe1000Hzprobetonewereflatin15(75%),17(85%)and13(65%)oftheearsininfantswithprolongedwaveIlatencies.For1000Hzadmittance,susceptanceandconductanceTympanograms,theagreementbetweentympanometryandABRresultswere90.0%,92.0%and86.0%withkappaat0.783,0.831and0.690,respectively.Conclusion1000Hzprobetonetympanometryisapromisingmiddleearfunctiontestforinfantsof1-6monthsage,while226Hzand678Hzprobetonesarelessefficientindetectingmiddleeardysfunctionininfants.

简介：Low-frequencychorusemissionshaverecentlyattractedmuchattentionduetothesuggestionthattheymayplayimportantrolesinthedynamicsoftheVanAllenBelts.However,themechanism(s)generatingtheselow-frequencychorusemissionshavenotbeenwellunderstood.Inthisletter,wereportaninterestingcaseinwhichbackgroundplasmadensityloweredthelowercutofffrequencyofchorusemissionsfromabove0.1fce(typicalordinarychorus)to0.02fce(extremelylow-frequencychorus).Thoseextremelylow-frequencychoruswaveswereobservedinaratherdenseplasma,wherethenumberdensityNewasfoundtobeseveraltimeslargerthanhasbeenassociatedwithobservationsofordinarychoruswaves.Forsuprathermalelectronswhosefreeenergyissuppliedbyanisotropictemperatures,lineargrowthrates(calculatedusingin-situplasmaparametersmeasuredbytheVanAllenProbes)showthatwhistlermodeinstabilitycanoccuratfrequenciesbelow0.1fcewhenthebackgroundplasmadensityNeincreases.EspeciallywhenNereaches90cm^-3ormore,thelowestunstablefrequencycanextendto0.02fceorevenless,whichisconsistentwithsatelliteobservations.Therefore,ourresultsdemonstratethatadensebackgroundplasmacouldplayanessentialroleintheexcitationofextremelylowfrequencychoruswavesbycontrollingthewavegrowthrates.

简介：有绗维素酶的帮助的chitosan(72.05%的DD)的降级在45的条件下面被执行，pH5.0并且1:15(chitosan/enzyme)的比率。结果证明绗维素酶能降级chitosan高效地。chitosan的粘性很快速被减少，减少释放的糖在降级期间与时间被增加。由使用膜，水解作用混合的分离被学习。蛋白质的拒绝能被到达是low-molecular-weightchitosans的99.74%.65.9%是不到2kDa。chitosan被发现比chitosan和发射度好的low-molecular-weight的溶解度能到达是在pH的全部范围的超过95%113。

简介：Adirectsynthesisofmethyllevulinatefromcellulosealcoholysisinmethanolmediumundermildcondition(180210C)catalyzedbyextremelylowconcentrationsulfuricacid(0.01mol/L)andtheproductisolationweredevelopedinthisstudy.Effectsofdifferentprocessvariablestowardsthecatalyticperformancewereperformedasafunctionofreactiontime.Theresultsindicatedthatsulfuricacidconcentration,temperatureandinitialcelluloseconcentrationhadsignificanteffectsonthesynthesisofmethyllevulinate.Anoptimizedyieldofaround50%wasachievedat210Cfor120minwithsulfuricacidconcentrationof0.01mol/Landinitialcelluloseconcentrationbelow100g/L.Theresultingproductmixturewasisolatedbyadistillationtechniquethatcombinesanatmosphericdistillationwithavacuumdistillationwheren-dodecanewasaddedtohelpdistilltheheavyfraction.Thelightfractionincludingmainlymethanolcouldbereusedasthereactionmediumwithoutanysubstantialchangeintheyieldofmethyllevulinate.ThechemicalcompositionandstructuraloflowerheavyfractionwerecharacterizedbyGC/MS,FTIR,1H-NMRand13C-NMRtechniques.Methyllevulinatewasfoundtobeamajoringredientoflowerheavyfractionwiththecontentover96%.Thispathwayisefficient,environmentallybenignandeconomicalfortheproductionofpurelevulinateestersfromcellulose.

简介：Highlevelsoflowmolecularweight(LMW)IgMincertaindiseasesareassociatedwithclinicalandlaboratoryindiceswhichreflecttheseverityofthedisease.TheseassociationssuggestthatLMWIgMmayplayanimportantroleintheimmunopathogenesisofthesediseases.TofurtherapproachthequestionconcerningthefunctionalactivityofLMWIgMindisease,apanelofLMWIgMandhighmolecularweight(HMW)IgMpreparationswithorwithoutrheumatoidfactor(RF)activitywereusedtoinvestigatetheirantibodybindingactivityandtheireffectorfunction.ItwasfoundthatLMWIgM-RFandHMWIgM-RFhadasimilarbindingcapacitytoFcfragmentastherewasnosignificantdifferenceintheaffinityindexbetweenthem.ItfurthershowedthattherateofactivationandtotalamountofutilizationofcomplementbyLMWIgMandHMWIgMwassimilar,althoughthemeanfluorescenceofC3depositionbyIgM-RFandHMWIgM-RFwasslightlyhigherthanthatofLMWIgM-RFandothercontrolRFantibodies.However,thecurrentstudydemonstratedthatLMWIgMhadstrongneutrophilactivatingpropertieswhencomparedwithHMWIgM.ThesefindingssuggestthatonemechanismofLMWIgMcontributingtotheimmunopathogenesisofRAmaybeduetotheformationofcirculatingimmunecomplex(CIC)byLMWIgMwithsubsequentactivationofneutrophils.WhetherLMWIgMhasotherfunctionalactivityindiseaseisunclearandneedsfurtherinvestigation.

简介：BACKGROUND:Exposuretolow-levelleadhasatoxiceffectonthedevelopmentofneonates,whichhasattractedwideattention.Colostrumleadlevelcanbeusedastheindicationofleadexposure.OBJECTIVE:Toobservetherelationshipofcolostrumleadlevelandtheneurobehavioraldevelopmentofinfants.DESIGN:Aprospectivecontrolobservation.SETTING:CenterforMaternalandChildHealth,ShanxiProvincialChildren'sHospital.PARTICIPANTS:Totally128neonatesoffull-termnormaldelivery,76maleand52female,fromShanxiProvincialMaternalandChildHealthCenterandJiexiuMaternalandChildHealthCenterwereinvolvedinthisstudy.Alltheinvolvedneonateshadnoperipartalischemic/hypoxichistoryorfetusintrauterinedevelopmentallag.Pregnantwomenhadnovariousacuteandchronicdiseasesinpregnancy,familyhistoryofneurologicaldiseaseoroccupationalleadexposure.128portionsofcolostrumsampleoffull-termnormaldeliverywerecollected.Informedconsentsofdetecteditemswereobtainedfromthepuerperantsandtheirrelatives.METHODS:①Experimentalgrouping:Leadlevelinthecolostrumwasdeterminedbyatomicabsorptionspectrometry.Accordingtoleadlevelinthecolostrum,theneonateswereclassifiedintotwoexposuregroupsofgreaterthanorequalto0.24μmol/Linahigh-levelleadgroupandlessthan0.24μmol/Linalow-levelleadgroup.②Experimentalevaluation:Mentaldevelopmentalindex(MDI)andpsychologicaldevelopmentalindex(PDI)of3-month-oldinfantswereevaluatedwithBayleyScalesofInfantDevelopment(BSID).TherelationshipsofMDI,PDIandcolostrumleadlevelwereperformedcorrelationregressionanalysis;Therelationshipofcolostrumleadlevelanddevelopmentwasperformedmulti-factoranalysiswithfamilyenvironmentandhealthquestionnaires.MAINOUTCOMEMEASURES:①EvaluationresultsofMDIandPDI.②Multi-factoranalysisresults.RESULTS:Totally128neonateswereinvolvedinthestudy.Tenandelevenneonateswerelostduetoemigra

简介：Low-molecular-weight(LMW)organicacidsexistwidelyinsoilsandhavebeenimplicatedinmanysoilprocesses.TheobjectiveofthepresentpaperwastoevaluateeffectoftwoLMWorganicacids,citricacidandoxalicacid,onCl-adsorptionbythreevariablechargesoils,alatosol,alateriticredsoilandaredsoil,usingabatchmethod.TheresultsshowedthatthepresenceofcitricacidandoxalicacidledtoadecreaseinCl-adsorptionwithlargerdecreasesforcitricacid.AmongthedifferentsoilsGl-adsorptioninthelateriticredsoilandtheredsoilwasmoreaffectedbyboththeLMWorganicacidsthanthatinthelatosol.

简介：Fourcoumarinderivatives(4a―4d)withdifferentalkoxychainsweresynthesized.Itwasfoundthatcompound4dshowedabettergelationabilitythantheothercompounds,forexample,itcouldself-assembleintoorganogelsinvariousorganicfluidsviaultrasoundtreatmentorheating-coolingprocess,whereascompound4ccouldonlygelinafewmixedsolventsandcompounds4a,4bcouldnotformorganogel.TheresultsfromfluorescentandFT-IRspectraindicatethatπ-πinteractionhadaneffectontheformationoftheorganogelsofcompound4dbesidesH-bondingandvanderWaalsinteraction,whichwerethedrivingforcesfortheself-assemblingofcompound4cingelstate.Thegelofcompound4dintoluenecouldemitstrongfluorescenceunderUVirradiationandthe[2+2]cyc-lo-additionwassuggestedby1HNMRandfluorescencespectroscopy.Thislight-sensitiveorganogelmightfindapplicationinopticalmaterials.

简介：Thisstudyaimsattheeffectsofanintakeoflowmolecularweightcornpeptides(LMCPs)preparedfromzeinonalcoholmetablisminrats.LMCPs(1.0g/kgbodyweight)in15%ethanol(10mL/kgbodyweight)weregiventoWisterratsbyintragastricgavage.Theassayofbloodethanolwasconductedbyusingtheenzyme-basedassaykit.Theaminoacidanalysiswasmadewithanaminoacidanalyzer.ThedataoftheanimalexperimentsshowedthatLMCPscouldacceleratethemetabolismofalcoholinrats.Inthecontrolgroup,thebloodethanolconcentrationreachedthemaximumlevelof(827.0±77.3)mg/Lafterethanolloadingfor30min,thengraduallydecreased.Incontrast,thebloodethanolconcentrationonlyreached(527.25±47.0)mg/Lafter30mininthegroupofLMCPstaken.TheseresultsindicatethatLMCPscoulddecreaseethanolconcentrationinbloodrapidly.

简介：Carbazole-basedbi-functionalphotorefractivepolyacrylateswerepreparedviafreeradicalpolymerizationandpost-azo-couplingreaction.ThestructureofpolymerswascharacterizedbyFouriertransforminfraredspectroscopy(FTIR)andprotonnuclearmagneticresonance(1H-NMR)spectroscopy.Thedifferentialscanningcalorimetry(DSC)andthethermalgravimetricanalysis(TGA)wereusedtocharacterizethethermalpropertyofpolymers.Theresultsindicatethatthoughtheglasstransitiontemperature(Tg)ofpolymersincreaseswithincreasingtheratioofNLOgroups,thepolymerswithdifferentratiosofNLOgroupsstillallshowlowglasstransitiontemperaturesaround60°C,andgoodthermalstability,whicharefavorabletothepracticalapplicationofthesepolymers.Thegelpermeationchromatographic(GPC)resultindicatesthatthesepolymersallhavehigh-molecular-weightwhichisfavorabletothelongtermstabilityofthematerial.Further,thesepolymershavegoodsolubilityinchloroformsolvent,andthesolutionscaneasilybefabricatedintoopticallytransparentfilms.Gaincoefficientsof75cm-1,185cm-1and66cm-1canbeobservedatzeroexternalelectricfieldwithoutanyadditionagentorpre-polingforpolymersP-2,P-3andP-4respectively.ThedifferentcontentsofNLOgroupsresultinthedifferentpropertiesofpolymersP-2,P-3andP-4.

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简介：Nickel-basedcatalyst[N,N]NiBr2,inwhich[N,N]standsforN-(2,6-diisopropylphenyl)pyridine-2-carboxaldimine,showshighactivityforethylenepolymerizationinthepresenceoforganoaluminumcompoundsunderhighethylenepressuretoyieldpolyethylenecharacteristicoflowmolecularweightandhighlybranchedchains.Tolueneasthesolventismoreinfavorofcatalystactivity,highermolecularweightandbranchedchainsinpolyethylenestructureascomparedtohexanesolvent.

简介：AIM:Toinvestigatetheeffectsofthefreeradicalscavengerbis(1-hydroxy-2,2,6,6-tetramethyl-4-piperidinyl)decandioate(IAC)inthedextransodiumsulphate(DSS)experimentalmodelofulcerativecolitis.METHODS:ColitiswasinducedinSpragueDawleymaleratsbyadministrationof5%DSSindrinkingwater.IAC(30mg/kg,lipophilicorhydrophilicform)wasadministereddaily(orallyorip)for6duntilsacrifice.Colonicdamagewasassessedbymeansofindirect(DiseaseActivityIndexscore)anddirectmeasures(macroscopicandmicroscopicscores)andmyeloperoxidase(MPO)activity.NeutrophilinfiltrationwithinthetissueandglutathioneS-transferaseactivitywerealsoinvestigated.RESULTS:DSS-inducedcolitisimpairedbodyweightgainandmarkedlyincreasedallinflammatoryparameters.Six-daytreatmentwithlipophilicIACsignificantlyreducedintestinaldamagecausedbyinflammation,inducedadown-regulationinMPOactivity(0.72±0.12and0.45±0.12withlipophilicIACpoandip,respectively,vs1.10±0.27inuntreatedDSScolitisanimals)andminimizedDSS-inducedneutrophilinfiltration,whilehydrophilicIACadministeredorallydidnotameliorateDSS-induceddamage.CONCLUSION:TheseresultssupportthehypothesisthatreactiveoxygenmetabolitescontributetoinflammationandthattheradicalscavengerIAChastherapeuticpotentialininflammatoryboweldisease.

简介：Insitucompatibilizationoflowdensitypolyehylene(LDPE)(30%)andnylon-6(70%)blendsthroughone-stepreactiveextrusionusingt-BuOOHasaninitiatorandlowmolec-ularweightinterfacialagentsascompatibilizerswasstudied.Thecompatibilizercontainedalongchainbydrocarbon,doublebondandtwopolarfunctionalgroupswhichwascapableofreactingwithbothLDPEandnylon-6inthepresenceofinitiatortoformacopolymerattheinterfaceofthetwopolymerphases.Theextrudedblendsexhibitedsignificanten-hancementintheircompatibilitybasedonmorphological,thermalanalysisandmechanicalstudies.Theeffectofthehydrocarbonchainlengthandstructureofthefunctionalgroupofthecompatibilizerwasalsoexamined.Itwasfoundthatblendspreparedbyusingthecompatibilizercontaininglongerhydrocarbonchainandamidegrouphadbettermechanicalproperties.

简介：ASpecializedCommitteeofREInforma-tionundertheChineseRESocietyhasbeenformedwiththepurposeofstreng-theningtheexchangeofREinformationandpromotingthedevelopmentofREsci-enceandtechnologyathomeandabroad.ThefirstmeetingofthecommitteewasheldinBeijingonDecember23-25,1989,andwasattendedbyover100representa-tivesfromuniversitiesandscientificresearchinstitutionsinvariouspartsofChina.Amongthemweresomewell-knownscholarswhohavelongbeenengagedin

简介：Theeffectofsinteringdispersedandbulk,lowmolecularweight(Mn=50,000Da),nano-emulsionpolytetrafluoroethylene(PTFE)particlesneartheirmeltingpointisdescribed.Withthenascentparticlesconsistingofca.75nmdiameter,hexagonal,singlecrystals,sinteringat,e.g.,350℃,results,initially,inmergerofneighboringparticles,followedbyindividualmolecularmotiononthesubstrateandtheformationoffoldedchain,lamellarsinglecrystalsandspherulites,andon-edgeribbons.Itissuggestedthesestructuresdevelop,withtime,inthemesomorphic'melt'.Sinteringofthebulkresinyieldsextendedchain,bandstructures,aswellasfoldedchainlamellae;end-surfacetoend-surfacemerger,possiblybyend-to-endpolymerization,occurswithincreasingtime.