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17 个结果
  • 简介:Pilotspatialdisorientationisaleadingfactorcontributingtomanyfatalflyingaccidents.Spatialorientationistheproductofintegrativeinputsfromtheproprioceptive,vestibular,andvisualsystems.Vestibularneuritis(VN)canleadtosuddenpilotincapacitationinflight.VNiscommonlydiagnosedbydemonstrationofunilateralvestibularfailure,asunilaterallossofcaloricresponse.Asthistestreflectsthefunctionofthesuperiorpartofthevestibularnerveonly,casesofpureinferiornerveneuritiswillbelost.ThispaperdescribesafighterpilotwithsymptomssuggestiveofVNbutwithnormalcalorictestresults.Furthertestshowedunilaterallossofvestibularevokedmyogenicpotential.Webelievethatthepilotsufferedfrompureinferiornervevestibularneuritis.VEMPplaysamajorroleinthediagnosisofinferiornervevestibularneuritisinpilots.Aeromedicalconcernsarealsodiscussed.

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  • 简介:Growingevidencehasbeenfoundtosuggestthatearlydevelopmentofthecentralauditorysystemisdependentonacousticstimuli.Peripheraldamagecausedbynoiseexposureandototoxicdrugscaninducefunctionalandanatomicalchangesalongtheauditorypathways.Theinferiorcolliculus(IC)isauniquestructureintheauditorysystemlocatedbetweentheprimaryauditorynucleiofthebrainstemandthethala-mus.DamagetotheICinhibitorycircuitrymayaffectcentralauditoryprocessingandsoundperception.Here,wereviewsomeofthestrikingelectrophysiologicalchangesintheICthatoccurafternoiseexposureandototoxicdrugtreatment.AcommonoccurrencethatemergesintheICafterperipheraldamageishyper-excitabilityofsound-evokedresponse.ThehyperexcitabilityoftheICislikelyrelatedwithreducedinhibi-toryresponsethatrequiresnormalperipheralinputs.Earlyagehearinglosscanresultinalonglastingin-creasedsusceptibilitytoaudiogenicseizurewhichisrelatedtohyperactivityintheICevokedbyloudsounds.OurstudiessuggestthathearinglosscancauseincreasedICneuronresponsivenesswhichmayberelatedtotinnitus,hyperacusis,andaudiogenicseizure.

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  • 简介:AbstractBackground:Renal cell carcinoma (RCC) has the propensity to lead to venous tumor thrombus (VTT). Nephrectomy with tumor thrombectomy is an effective treatment option but is a technically challenging surgical procedure that is accompanied by a high rate of complications. The aims of this study were to investigate pre-operative imaging parameters for the assessment of inferior vena cava (IVC) wall invasion due to a tumor thrombus in patients with RCC and to identify predictors from the intra-operative findings.Methods:Clinical and imaging data were collected from 110 patients who underwent nephrectomy with IVC tumor thrombectomy (levels I-IV) for RCC and IVC tumor thrombus at the Peking University Third Hospital between May 2015 and March 2018. Univariable and multivariable logistic regression and receiver operating characteristic curves were used to assess the correlations between pre-operative imaging features and intra-operative macroscopic invasions of the IVC wall by tumor thrombus.Results:Among the 110 patients, 41 underwent partial or segmental resection of IVC. There were univariate associations of pre-operative imaging parameters that could be used to predict the need for IVC resection, including those of the Mayo classification, maximum anterior-posterior (AP) diameter of the renal vein at the renal vein ostium (RVo), maximum AP diameter of the VTT at the RVo and IVC occlusion. For the multivariable analysis, the AP diameter of the VTT at the RVo and IVC occlusion were associated with a significantly increased risk of invasion of the IVC wall by tumor thrombus. The optimum imaging thresholds included an AP diameter of the VTT at the RVo larger than 17.0 mm and the presence of IVC occlusion, with which we predicted invasions of the IVC wall requiring IVC resection. The probabilities of intra-operative IVC resection for patients without both independent factors, with an AP diameter of the VTT at the RVo larger than 17.0 mm, with IVC occlusion, and with both concurrent factors were 5%, 23%, 56%, and 66%, respectively.Conclusion:An increase in the AP VTT diameter at the RVo and the presence of complete occlusion of the IVC are independent risk factors for a high probability of IVC wall invasion by tumor thrombus.

  • 标签: Renal cell carcinoma Inferior vena cava Thrombus Imaging
  • 简介:<正>Drivenbytheincreasingsupplyofheavyoilswithdeterioratingquality,ahighnickel-resistantcatalystforcatalyticcrackingofinferiorcrudeoilswasdevelopedbytheResearchInstituteofPetroleumProcessing(RIPP).Catalystperformancewasevaluatedinalaboratoryfixedfluidizedbedreactor.Thetestresultsshowedthatthehighnickelresistancecatalystexhibitedgoodbottomscrackability,goodnickelresistance,andgoodadaptabilitytochangesinoperatingparameters,whichhadnoadverseeffectontheproductdistribution,indicatingtoamostpromisingprospectforapplicationofthiscatalystincatalyticcrackingofinferiorcrudeoil.

  • 标签: CATALYTIC CRACKING CRUDE OIL EQUILIBRIUM CATALYST
  • 简介:客观:为了学习寻找鼻音上的治疗学的效率和effecacy指导oflaser途径,为canalicular撕裂在吻合打破撕碎的眼泪的小管的结束。方法:受不了创伤的劣等的canalicular撕裂的49个病人(49只眼睛)被划分成控制组和指导激光的组。在眼泪的斑点和鼻音之间的距离撕碎的眼泪的小管的破结束是超过6公里。在眼皮损伤的管理的功课期间,病人被canalicular吻合操作在分别地在撕碎的眼泪的小管的结束找打破的鼻音与传统的方法和指导激光的方法对待。1条公里直径的硅酮试管作为stent在眼泪的经过被把管子插进4~6个月。结果:Inthe指导激光的组,在在撕碎的眼泪的小管的破结束找鼻音的吝啬的时间是(5。75±1.49)纪录,操作的吝啬的时间是(49.21±3.37)纪录;两个比控制组的显著地短(P<0.01)。指导thelaser组的痊愈率是96.55%,比控制组,但是没有统计意义(P>0.05)的高。结论:指导激光的方法对比传统的途径,和病人得更少的疼痛在撕碎的眼泪的小管的结束找打破的鼻音并且在canalicular吻合操作损坏快得多、更方便。

  • 标签: 临床应用 激光治疗 吻合术 微管损伤
  • 简介:ObjectiveFortycasesofIAMIwereexaminedwithcoronaryangiographyinordertostudytherelationshipofthevesselswiththeECGofIAMI.MethodsForcoronaryangiographyJudkin’smethodwasused;IAMIwasdiagnosedbythe1979WHO’sstandardofISHDandECGwasseparatelymeasuredbytwodoctors.ResultsMostofIAMIwithpolybranchcoronaryoritscollateraldisease(32.5%and42.5%)andonly10cases(25%)withsinglebranchcoronarydisease,whoseECGswereuntypical.ConclusionIAMIwithsingle-branchcoronarydiseasemightexpressasmildsymptomsandhavenotypicalECGchange.WhiletypicalECGchangeemerges,thecoronaryarteryalwaysshowedpoly-branchdiseaseorcollateralbranchobstructionandthediseasewouldbeadvanced.ItisimportanttopaymoreattentiontothecasesofIAMIwithoutclassicECGchangesoastogivediagnosisandtreatmentthemintime.

  • 标签: Acute INFERIOR MYOCARDIAL INFARCTION RELATED VESSELS
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  • 简介:AIM:Toinvestigatechangesinfundusexcyclotorsionafterinferiorobliquemyectomyormyotomy.METHODS:Therecordsof21patientsundergoingstrabismussurgerybyasinglesurgeonbetween2009and2012wereexamined.Onlypatientswhohadundergoneaninferiorobliquemyectomyormyotomy,withorwithouthorizontalrectusmusclesurgery,wereevaluated.Digitalfundusphotographswereobtained,andtheangleformedbyahorizontallinepassingthroughtheopticdisccenterandareferencelineconnectingthefoveolaandopticdisccenterwasmeasured.Associatedclinicalfactorsexaminedincludeageatthetimeofsurgery,presenceorabsenceofaheadtilt,degreeofpreoperativeverticaldeviation,torsionalangle,inferiorobliquemuscleoveraction/superiorobliquemuscleunderaction,andsurgerylaterality.Whethertheprocedurewasperformedaloneorincombinationwithahorizontalrectusmusclesurgerywasalsoexamined.RESULTS:Meanpreoperativetorsionalanglewas12.0±6.4°,whichdecreasedto6.9±5.7°aftersurgery(P<0.001,pairedt-test).Torsionalanglealsodecreasedfrom15.1±7.0°to6.2±4.3°inthemyectomygroup(P<0.001,pairedt-test)buttherewerenosignificantchangesinthemyotomygroup(P=0.093,Wilcoxonsignedranktest).Multivariablelinearregressionanalysisshowedthatpreoperativetorsionalangle,degreeofinferiorobliqueoveraction,andageatsurgeryindependentlyandsignificantlyaffectedpostoperativetorsionalangle.CONCLUSION:Meantorsionalangledecreasedafterinferiorobliquemyectomy.Degreeofpreoperativetorsionalangle,inferiorobliqueoveraction,andageatsurgeryinfluencepostoperativetorsionalangle.

  • 标签: OCULOMOTOR muscles STRABISMUS superior OBLIQUE PALSY
  • 简介:FragileXsyndromeisthemostcommonformofinheritedmentalretardationaffectingupto1in4000individuals.ThesyndromeisinducedbyamutationintheFMR1gene,causingadeficiencyinitsgeneby-productFMRP.ImpairmentinthenormalfunctioningofFMRPleadstolearningandmemorydeficitsandheightenedsensitivitytosensorystimuli,includingsound(hyperacusis).ThemolecularbasisoffragileXsyndromeisthoroughlyunderstood;however,theneuralmechanismsunderlyinghyperacusishavenotyetbeendetermined.Astheinferiorcolliculus(IC)istheprincipalmidbrainnucleusoftheauditorypathway,thecurrentstudyaddressesthequestionsunderlyingtheneuralmechanismofhyperacusiswithintheICoffragileXmice.AcuteexperimentswereperformedinwhichelectrophysiologicalrecordingsoftheICinFMR1-KOandWTmiceweremeasured.ResultsshowedthatQ-valuesforWTweresignificantlylargerthanthatofFMR-1KOmice,indicatingthatWTmiceexhibitsharpertuningcurvesthanFMR1-KOmice.WealsofoundtheratioofthemonotonicneuronsintheKOmicewasmuchhigherthantheWTmice.TheseresultssuggestthatlackofFMRPintheauditorysystemaffectsthedevelopmentalmaturationandfunctionofstructureswithintheauditorypathway,andinthiscasespecificallytheIC.ThedysfunctionobservedwithintheauditoryneuralpathwayandinparticulartheICmayberelatedtotheincreasedsusceptibilitytosoundasseeninindividualswithfragileXsyndrome.OurstudymayhelponunderstandingthemechanismsofthefragileXsyndromeandhyperacusis.

  • 标签: 下丘神经元 基因突变 点火性能 脆性X综合征 听觉通路 神经机制
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  • 简介:Durationisasalientfeatureofacousticsignalsincludingspeech.Durationtuningwasfirstreportedinfrogsandlaterinecholocatingbats.Morerecently,durationtuninghasbeenreportedinnon-echolocatingmammalsandappearstobeafundamentalencodingmechanismthroughouttheanimalkingdom.However,thedurationtuningreportedinthesenon-echolocatingmammalsappearstobemuchweakerthanthatinthepreviousstudiesonbats.Incontrasttothisfinding,ourrecentstudyreportedthatdurationtuningintheICinguineapigsappearedtobestrongwhenitwasmeasuredusinganappropriatetemporalwindow.Withsuchatemporalwindow,durationtuningwasfoundtobecompatiblewiththatofecho-locatingbats.Inthepresentreport,wefurtherdemonstratethatdurationtuningintheICofthisspeciesisestablishedbyinteractionbetweenexcitationandGABAergicinhibition.Inadditiontooverallincreaseinresponsiveness,applicationofbicuculline(BIC),aGABA-Areceptorantagonist,wasfoundtosignificantlyreduceoreliminatedurationselectivityin44outofthe67neuronsthatshowedcleardurationtuningfromasampleof340neurons.

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  • 简介:Objective:Tostudytheeffectofnervegrowthfactor(NGF)andSchwanncellsonaxonregenerationoftheinferioralveolarnervefollowingmandibularlengtheningwithdistractionosteogenesis.Methods:Unilateralmandibularosteodistractionwasperformedin9healthyadultmalegoatswithadistractionrateof1mm/d.Every3goatswerekilledondays7,14and28aftermandibularlengthening,respectively.TheinferioralveolarnervesinthedistractioncalluswereharvestedandprocessedforultrastructuralandNGFimmunohistochemicalstudy.Theinferioralveolarnervesfromthecontralateralsidewereusedascontrols.Results:Onday7afterdistraction,axondegenerationandSchwanncellproliferationwereobserved,andverystrongstainingofNGFinthedistractednervewasdetected.Onday14afterdistraction,axonregenerationandremyelinationwereeasilyobserved,andNGFexpressionstartedtodecline.Onday28afterdistraction,thegrayscaleofNGFimmunoreactivityrecoveredtothenormalvalueandtheSchwanncellsalmostrecoveredtotheirnormalstate.Conclusions:Gradualmandibularosteodistractioncanresultinmildormoderateaxondegenerationoftheinferioralveolarnerve.NervetraumamaystimulatetheproliferationofSchwanncellsandpromotethesynthesisandsecretionofNGFintheSchwanncells.SchwanncellsandNGFmightplayimportantrolesinaxonregenerationoftheinjuredinferioralveolarnervefollowingmandibularlengthening.

  • 标签: 下腭延长术 轴突 神经再生 神经生长因子 许旺氏细胞 分散成骨
  • 简介:BackgroundAcuteinferiorandanteriormyocardialinfarctionoftenleadstorightventricular(RV)functiondecrease.EstimationofRVfunctionischallengingduetothecomplexRVgeometry.Fewstudieshavebeenconductedtoinvestiogatetheeffectsofacutemyocardialinfarction(AMI)onrightventricularfunctions(RVFs).Two-dimensionSpeckleTrackingImaging(STI)isanovelmethodthatallowsforasegmentbasedmeasurementofmyocardialdeformationandmayhavethepotentialtoquantifyRVdysfunctionmorepreciselythantheconventionalparametersofRVfunction.Therefore,inthisstudyweanalyzedtheRVfunctioninAMIpatientsbyusingthisnoveltechnique.MethodsThirty-fourpatientswithacuteinferiormyocardialinfarction(AIMI),31patientswithacuteanteriormyocardialinfarction(AAMIand30agematchedhealthyindividualswereenrolledforthestudy.2Dspeckletrackingimaging(STI)wasusedtoobtain2Dimagingattheapicalfour-chamberviewunderrestcondition.Peaksystolicstrainsandstrainratesofallsegmentsinrightventricularfreewallwereanalyzed.ResultsComparedtothenormalcontrolgroup,longitudinalpeaksystolicstrain(ε),strainrate(SRs),earlydiastolicstrainrate(SRe)andlatediastolicstrainrate(SRa)inallsegmentsofrightventricularfreewallweresignificantlylowerinAMIpatients.ε,SRs,SReandSRaofeachsegmentofRVintheAIMIgroupweredecreasedsignificantlythanthoseofthenormalcontrolgroup(P<0.05).ε,SRs,SReandSRaofeachsegmentofRVintheAAMIgroupwerelowerthantheseinthecontrolgroup.ExceptforbasalsegmentalSRa,thereweresignificantdifferencesamongotherparameters(P<0.05).ConclusionsRVFsareimpairedinAMIpatients.RVFscouldbeaccuratelyandsensitivelyassessedwithSTI.

  • 标签: 急性心肌梗死 二维成像 患者 追踪 斑点 评价
  • 简介:spinalmotionpivot,spinalmanipulation,theangleoffacetjoint,forcedirection,cylinderpivotmotiontheoryThespinaljointconsistsofadiscandposteriorfacetjoints.Itisthebiomechanicalstructurethatenablesthespinewithsix(6)freedomsofmovementsofflexion/extension,sidebendsandrotations.Weidentifiedthatthesamespinaljointsinitiate,eliminateandcontrolspinalmovement.Thesefourjointsaretheatlanto-occipitalandtheatlanto-odontoidjoints,C7/T1,T12/L1andL5/S1.Theword“pivot”iscommonlyusedtodescribeanimportantruruingporintormatterinChineselanguage.Wedefinetheabovefourjointsas“pivots”inthisarticle.Thejointsarebriefedas“Occipital-vertebralpivot”(atlanto-occipitalandatlanto-odontoidjoint),“cervicalthoracicpivot”(C7/T1),“thoracic-lumbarpivot”(T12/L1)and“lumbar-sacrumpivot”(L5/S1).Aftermeasuring20humanspinalcolumns(drybones),observingtheanglebetweenthevertebralbodyandtheinferiorarticularfaeet,reviewingthespinalanatomyandbiomechanicsandanalyzingtheChinesespinalmanipulationtechniquesandtheory,thefollowingisourreport:

  • 标签: 脊柱轴向运动 脊柱关节 测量 解剖学 生物力学
  • 简介:摘要:劣质煤具有发热量低、杂物多和高水分、高粘性、高灰分等特点。在发热量测定过程不采取一些辅助方法,测定结果的准确性和精密度难以保证。低位发热量结果又是电厂作为给供应商的结算依据,而发热量测定结果的高低准确性就成了供需双方关注的焦点。在煤炭供需日益紧张的情况下,为缓解这种压力的办法是有效消除测定中存在误差,减少与供方的煤质纠纷,在分析样中添加已知质量和热值的苯甲酸进行发热量测定,从而提高测定结果的准确度。

  • 标签: 劣质煤  发热量  准确性