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  • 简介:AbstractBackground:In recent years, norepinephrine has attracted increasing attention for the management of maternal hypotension during elective cesarean section with spinal anesthesia. Intermittent bolus is a widely used administration paradigm for vasopressors in obstetric anesthesia in China. Thus, in this randomized, double-blinded study, we compared the efficacy and safety of equivalent bolus norepinephrine and phenylephrine for rescuing maternal post-spinal hypotension.Methods:In a tertiary women’s hospital in Nanjing, China, 102 women were allocated with computer derived randomized number to receive prophylactic 8 μg norepinephrine (group N; n = 52) or 100 μg phenylephrine (group P; n = 50) immediately post-spinal anesthesia, followed by an extra bolus of the same dosage until delivery whenever maternal systolic blood pressure became lower than 80% of the baseline. Our primary outcome was standardized maternal cardiac output (CO) reading from spinal anesthesia until delivery analyzed by a two-step method. Other hemodynamic parameters related to vasopressor efficacy and safety were considered as secondary outcomes. Maternal side effects and neonatal outcomes were collected as well.Results:Compared to group P, women in group N had a higher CO (standardized CO 5.8 ± 0.9 vs. 5.3 ± 1.0 L/min, t = 2.37, P = 0.02) and stroke volume (SV, standardized SV 73.6 ± 17.2 vs. 60.0 ± 13.3 mL, t = 4.52, P < 0.001), and a lower total peripheral resistance (875 ± 174 vs. 996 ± 182 dyne·s/cm5, t = 3.44, P < 0.001). Furthermore, the incidence of bradycardia was lower in group N than in group P (2% vs. 14%, P= 0.023), along with an overall higher standardized heart rate (78.8 ± 11.6 vs. 75.0 ± 7.3 beats/min, P = 0.049). Other hemodynamics, as well as maternal side effects and neonatal outcomes, were similar in two groups (P > 0.05).Conclusions:Compared to equivalent phenylephrine, intermittent bolus norepinephrine provides a greater CO for management of maternal hypotension during elective cesarean section with spinal anesthesia; however, no obvious maternal or neonatal clinical advantages were observed for norepinephrine.

  • 标签: Norepinephrine Phenylephrine Cardiac output Cesarean section
  • 简介:PlasmonicresonancewithFanolineshapehasattractedagreatdealofrecentinterest.Herewedesignanewstructurewithadimergratinguponagoldfilmseparatedbyalayerofsilicaspacer,whichhastworesonantmodescorrespondingtothedimer’slocalizedsurfaceplasmonresonanceandthesurfaceplasmonresonanceexcitedbythedimergrating.Thisstructurehasthreeadvantagesfornear-infrareddetectioninwater.First,itprovidestworesonantmodestoenhancetheexcitationandscatteredsignalsofsurface-enhancedRamanscattering.Second,couplingofthesetwomodesresultsinaFanoresonance,providingahigherelectricfieldenhancement.Finally,thedimerprovidesmoreflexibletunabilitycomparedtoasinglediskstructure.

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  • 简介:Thispapergeneralizesthesingle-shellKidder'sself-similarsolutiontothedouble-shellonewithadiscontinuityindensityacrosstheinterface.AnisentropicimplosionmodelisconstructedtostudytheRayleigh-Taylorinstabilityfortheimplosioncompression,AGodunov-typemethodintheLagrangiancoordinatesisusedtocomputetheone-dimensionalEulerequationwiththeinitialandboundaryconditionsforthedouble-shellKidder'sself-similarsolutioninsphericalgeometry.Numericalresultsareobtainedtovalidatethedouble-shellimplosionmodel.Byprogrammingandusingthelinearperturbationcodes,alinearstabilityanalysisontheRayleigh-Taylorinstabilityforthedouble-shellisentropicimplosionmodelisperformed.Itisfoundthat,whentheinitialperturbationisconcentratedmuchclosertotheinterfaceofthetwoshells,orwhenthesphericalwavenumberbecomesmuchsmaller,themodalradiusoftheinterfacegrowsmuchfaster,i.e.,moreunstable.Inaddition,fromthespatialpointofviewforthecompressibilityeffectontheperturbationevolution,thecompressibilityoftheoutershellhasadestabilizationeffectontheRayleigh-Taylorinstability,whilethecompressibilityoftheinnershellhasastabilizationeffect.

  • 标签: 不稳定性分析 自相似解 线性扰动 双壳 Rayleigh Taylor
  • 简介:BasedonGlobalOceanDataAssimilationSystem(GODAS)andNCEPreanalysisdata,atmosphericandoceanicprocessespossiblyresponsiblefortheonsetofthe2011/12LaNiaevent,whichfollowedthe2010/11LaNiaeven—referredtoasa'doubledip'LaNia—areinvestigated.Thekeymechanismsinvolvedinactivatingthe2011/12LaNiaareillustratedbythesedatasets.ResultsshowthatneutralconditionswerealreadyevidentintheequatorialeasternPacificduringthedecayingphaseofthe2010/11LaNia.However,isothermalanalysesshowobviouslycoldwaterstillpersistingatthesurfaceandatsubsurfacedepthsinoff-equatorialregionsthroughoutearly2011,beingmostpronouncedinthetropicalSouthPacific.ThenegativeSSTanomaliesinthetropicalSouthPacificactedtostrengthenasouthernwindacrosstheequator.ThesubsurfacecoldwaterinthetropicalSouthPacificthenspreadnorthwardandbrokeintotheequatorialregionatthethermoclinedepth.Thisincursionprocessofoff-equatorialsubsurfacecoldwatersuccessfullyinterruptedtheeasternpropagationofwarmwateralongtheequator,whichhadpreviouslyaccumulatedatsubsurfacedepthsinthewarmpoolduringthe2010/11LaNiaevent.Furthermore,theincursionprocessstrengthenedasaresultoftheoff-equatorialeffects,mostlyinthetropicalSouthPacific.ThenegativeSSTanomaliesthenreappearedinthecentralbasininsummer2011,andactedtotriggerlocalcoupledair–seainteractionstoproduceatmospheric–oceanicanomaliesthatdevelopedandevolvedwiththesecondcoolinginthefallof2011.

  • 标签: 赤道东太平洋 入侵过程 LA 冷水 事件 NCEP再分析资料
  • 简介:Theconservationlawsforthe(1+2)-dimensionalZakharov–Kuznetsovmodifiedequalwidth(ZK-MEW)equationwithpowerlawnonlinearityareconstructedbyusingNoether’sapproachthroughaninterestingmethodofincreasingtheorderofthisequation.Withtheaidofanobtainedconservationlaw,thegeneralizeddoublereductiontheoremisappliedtothisequation.ItcanbeshownthatthereducedequationisasecondordernonlinearODE.Finally,someexactsolutionsforaparticularcaseofthisequationareobtainedaftersolvingthereducedequation.

  • 标签: 二阶非线性常微分方程 精确解 幂律 改性 守恒律 相等
  • 简介:Wereportonanall-fiberoscillatorfollowedbyanall-fiberamplifiertoproduceasshortas382fslaserpulseswithupto0.9Waveragepower.Theoscillatorisanall-normal-dispersionall-fiberdissipativesolitonlaseroperatingat1030nm,andoperatingindissipativesolitonmode.Theamplifierstageismainlybasedonadouble-cladding20μmradiusytterbium-dopedfiberpumpedbyanupto2.5WCWlasersource.Theoptical-to-opticalconversionamplifierefficiencyisaround40%.Toourknowledge,thisisthefirstreportofanall-fibermode-lockedfiberlaseroscillatoramplifiedbyanall-fiberamplifier.

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  • 简介:修改multiwavelength活跃地锁模式的纤维戒指激光被建议并且试验性地示威了。在这种激光,放射激光的稳定的multiwavelengths被把串联取样的纤维布拉格栅栏(SFBG)集成到激光洞完成。实现活跃地锁模式的技术,一种双戒指洞配置被用来保证为放射激光的所有波长的洞长度是相同的。因此,同时的模式锁住所有波长被使用一样的锁模式的信号成功地完成了。

  • 标签: 布拉格光栅 光纤激光器 锁定模式 多波长
  • 简介:SiliconEpitaxialWaferforXBandDoubleRead-typeDDRIMPATTDiodesbyAtmosphere/LowPressureGrowthTechniqtWangXiangwuandLuChunyi王向武,陆春...

  • 标签: Si EPITAXY Multilayer X BAND DDR
  • 简介:阴极材料李[CoxNiyMn1?x?y]为锂的O2第二等的电池被一条新线路作为一位先锋用分层的双氢氧化物(LDH)准备了。结果有-NaFeO2结构的分层的阶段在菱形的系统结晶,与有到0.47nm的夹层间距结束的空格组R-3m。X光检查光电子光谱学(XPS)被用来测量公司,Ni和Mn的氧化状态。在结构和李的电气化学的性质上改变Co/Ni/Mn比率的效果[CoxNiyMn1?x?y]O2被X光检查衍射和电气化学的测试调查了。产品表明了相当稳定的骑车行为,与为有Co/Ni/Mn=1/1/1的分层的材料的118mAh/g的一个可逆能力。

  • 标签: 层状正极材料 层状双金属氢氧化物 层状前体 O2 X射线光电子能谱 合成
  • 简介:Indouble-pulselaser-inducedbreakdownspectroscopy(DP-LIBS),thecollinearfemtoseconddouble-pulselaserconfigurationisexperimentallyinvestigatedwithdifferentinitialsampletemperaturesusingaTi:sapphirelaser.Theglasssampleisablatedtoproducetheplasmaspectroscopy.Duringtheexperiment,thedetectedspectrallinesincludetwoNa(I)lines(589.0nmand589.6nm)andoneCa(I)lineatthewavelengthof585.7nm.Theemissionlinesaremeasuredatroomtemperature(22°C)andthreehigherinitialsampletemperatures(Ts=100°C,200°C,and250°C).Theinter-pulsedelaytimerangesfrom-250psto250ps.Theinter-pulsedelaytimeandthesampletemperaturestronglyinfluencethespectralintensity,andthespectralintensitycanbesignificantlyenhancedbyincreasingthesampletemperatureandselectingtheoptimizedinter-pulsetime.Forthesameinter-pulsetimeof0ps(single-pulseLIBS),theenhancementratioisapproximately2.5atTs=200°CcomparedwiththatobtainedatTs=22°C.Forthesameinter-pulsetimeof150ps,theenhancementratiocanbeupto4atTs=200°CcomparedwiththatobtainedatTs=22°C.Thecombinedenhancementeffectsofthedifferentinitialsampletemperaturesandthedouble-pulseconfigurationinfemtosecondLIBSaremuchstrongerthanthatofthedifferentinitialsampletemperaturesorthedouble-pulseconfigurationonly.

  • 标签: LASER-INDUCED BREAKDOWN spectroscopy FEMTOSECOND laser double
  • 简介:TheenergybanddiagramandchargedistributionoftheunintentionaldopedAIGaN/GaN/AIGaN/GaNdoubleheterostructurewereobtainedbyself-consistentPoissonSchroedingercalculations.Theseverebandtiltingandhightwo-dimensionalelectrongas(2DEG)densitymainlyattributetothelargeinternalpolarizationintensity,whichisc/osetoalinearfunctionorAlcomposition.TheinfluenceorAlcompositionisinvestigated.Theresultsshowthatbandtiltingenlargesand2DEGgainswithAIcomposition,andtwo-dimensionalholegasoccurswhenAIcompositionreachesacertainextent.TheinfluenceorAlcompositionandtwo-dimensionalholegas(2DHG)ondevicesisdiscussed.

  • 标签: 能带图 电荷分布 双重异结构 自相容泊松-施荣丁格尔计算 氮化镓