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308 个结果
  • 简介:AbstractBackground:Recent studies suggest that a healthy diet helps to prevent the development of Alzheimer disease (AD). This study aimed to investigate whether spicy food consumption is associated with cognition and cerebrospinal fluid (CSF) biomarkers of AD in the Chinese population.Methods:We enrolled 55 AD patients and 55 age- and gender-matched cognitively normal (CN) subjects in a case-control study, as well as a cohort of 131 participants without subjective cognitive decline (non-AD) in a cross-sectional study. Spicy food consumption was assessed using the Food Frequency Questionnaire (FFQ). Associations of FFQ scores with cognition and CSF biomarkers of AD were analyzed.Results:In the case-control study, spicy food consumption was lower in AD patients than that in CNs (4.0 [4.0-8.0] vs. 8.0 [4.5-10.0], P < 0.001); FFQ scores were positively associated with Mini-Mental Status Examination scores in the total sample (r = 0.218, P = 0.014). In the cross-sectional study, the association between spicy food consumption and cognition levels was verified in non-AD subjects (r = 0.264, P = 0.0023). Moreover, higher FFQ scores were significantly associated with higher β-Amyloid (1-42) (Aβ42) levels and lower phospho-tau/Aβ42 and total tau/Aβ42 ratios in the CSF of non-AD subjects (P < 0.05).Conclusion:Spicy food consumption is closely related to higher cognition levels and reversed AD biomarkers in the CSF, suggesting that a capsaicin-rich diet might have the potential to modify the cognitive status and cerebral pathologies associated with AD.

  • 标签: Alzheimer disease Biomarker Capsaicin Cerebrospinal fluid Cognition Spicy food
  • 简介:AbstractObjective:To describe the procedure and results of an adapted closure and reconstruction technique for translabyrinthine surgery that focuses on identifying and managing potential pathways for CSF egress to the middle ear and Eustachian tube.Methods:Retrospective review of a cohort of translabyrinthine acoustic neuroma cases that were reconstructed using this technique.Results:In addition to meticulous packing of potential conduits using soft tissue, hydroxyapatite cement is used to seal opened air cell tracts prior to obliteration of the mastoid defect using adipose tissue. Early results of a small patient cohort using this technique are encouraging and there were no wound infections. There was a single case of CSF rhinorrhea associated with incomplete sealing of opened petrous apex cells, with no recurrence after appropriate implementation of the described protocol during revision surgery.Conclusion:Proactive management of potential conduits of CSF egress including opened air cell tracts has a high likelihood of reducing rates of rhinorrhea and need for revision surgery after the translabyrinthine approach to the posterior fossa.

  • 标签: Translabyrinthine approach Cerebrospinal fluid leak Rhinorrhea Air cell tract Petrous apex Eustachian tube Hydroxyapatite cement
  • 简介:ObjectivePorencephaliccystpresentingwithotologicinvolvementisuncommon.Onlyafewcaseshavebeenreported.Wereportararecaseofcerebrospinalfluid(CSF)otorrheacausedbyamassiveporencephaliccystencompassingthelefttemporalandoccipitallobes.TheCSFleakwasrepairedsuccessfullyusingatransmastoidapproachwithfacia,abdomenfatandfibringluetosealtheosseousdefectsinthesinoduralangle.AreviewoftheliteratureconcerningporencephaliccystandCSFotorrheaisalsopresented.

  • 标签: 文献综述 脑脊液 囊肿 病例报告 纤维蛋白胶 脑脊髓液
  • 简介:AbstractObjective:To describe and assess the repair technique and perioperative management for cerebrospinal fluid (CSF) leak resulting from extensive anterior skull base fracture via extradural anterior skull base approach.Methods:This was a retrospective review conducted at the Department of Neurosurgery of the Shanghai Tenth People's Hospital from January 2015 to April 2020. Patients with traumatic CSF rhinorrhea resulting from extensive anterior skull base fracture treated surgically via extended extradural anterior skull base approach were included in this study. The data of medical and radiological records, surgical approaches, repair techniques, peritoperative management, surgical outcome and postoperative follow-up were analyzed. Surgical repair techniques were tailored to the condition of associated injuries of the scalp, bony and dura injuries and associated intracranial lesions. Patients were followed up for the outcome of CSF leak and surgical complications. Data were presented as frequency and percent.Results:Thirty-five patients were included in this series. The patients’ mean age was 33 years (range 11-71 years). Eight patients were treated surgically within 2 weeks; while the other 27 patients, with prolonged or recurrent CSF rhinorrhea, received the repair surgery at 17 days to 10 years after the initial trauma. The mean overall length of follow-up was 23 months (range 3-65 months). All the patients suffered from frontobasal multiple fractures. The basic repair tenet was to achieve watertight seal of the dura. The frontal pericranial flap alone was used in 20 patients, combined with temporalis muscle and/or its facia in 10 patients. Free fascia lata graft was used instead in the rest 5 patients. No CSF leak was found in all the patients at discharge. There was no surgical mortality in this series. Bilateral anosmia was the most common complication. At follow-up, no recurrent CSF leak or meningitis occurred. No patients developed mucoceles, epidural abscess or osteomyelitis. One patient ultimately required ventriculoperitoneal shunt because of progressive hydrocephalus.Conclusion:Traumatic CSF rhinorrhea associated with extensive anterior skull base fractures often requires aggressive treatment via extended intracranial extradural approach. Vascularized tissue flaps are ideal grafts for cranial base reconstruction, either alone or in combination with temporalis muscle and its fascia—fascia lata sometimes can be opted as free autologous graft. The approach is usually reserved for patients with traumatic CSF rhinorrhea in complex frontobasal injuries.

  • 标签: Cerebrospinal fluid leak Anterior skull base repair Surgery
  • 简介:AbstractBackground:Cerebrospinal fluid (CSF) has been demonstrated as a better source of circulating tumor DNA (ctDNA) than plasma for brain tumors. However, it is unclear whether whole exome sequencing (WES) is qualified for detection of ctDNA in CSF. The aim of this study was to determine if assessment of ctDNA in CSF by WES is a feasible approach to detect genomic alterations of glioblastoma.Methods:CSFs of ten glioblastoma patients were collected pre-operatively at the Department of Neurosurgery, Sun Yat-sen University Cancer Center. ctDNA in CSF and genome DNA in the resected tumor were extracted and subjected to WES. The identified glioblastoma-associated mutations from ctDNA in CSF and genome DNA in the resected tumor were compared.Results:Due to the ctDNA in CSF was unqualified for exome sequencing for one patient, nine patients were included into the final analysis. More glioblastoma-associated mutations tended to be detected in CSF compared with the corresponding tumor tissue samples (3.56 ± 0.75 vs. 2.22 ± 0.32, P = 0.097), while the statistical significance was limited by the small sample size. The average mutation frequencies were similar in CSF and tumor tissue samples (74.1% ± 6.0% vs. 73.8% ± 6.0%, P = 0.924). The R132H mutation of isocitrate dehydrogenase 1 and the G34V mutation of H3 histone, family 3A (H3F3A) which had been reported in the pathological diagnoses were also detected from ctDNA in CSF by WES. Patients who received temozolomide chemotherapy previously or those whose tumor involved subventricular zone tended to harbor more mutations in their CSF.Conclusion:Assessment of ctDNA in CSF by WES is a feasible approach to detect genomic alterations of glioblastoma, which may provide useful information for the decision of treatment strategy.

  • 标签: Circulating tumor DNA Cerebrospinal fluid Glioblastoma Mutation Whole exome sequencing
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  • 简介:AbstractBackground:It is still unclear what the minimal infusion volume is to effectively predict fluid responsiveness. This study was designed to explore the minimal infusion volume to effectively predict fluid responsiveness in septic shock patients. Hemodynamic effects of fluid administration on arterial load were observed and added values of effective arterial elastance (Ea) in fluid resuscitation were assessed.Methods:Intensive care unit septic shock patients with indwelling pulmonary artery catheter (PAC) received five sequential intravenous boluses of 100 mL 4% gelatin. Cardiac output (CO) was measured with PAC before and after each bolus. Fluid responsiveness was defined as an increase in CO >10% after 500 mL fluid infusion.Results:Forty-seven patients were included and 35 (74.5%) patients were fluid responders. CO increasing >5.2% after a 200 mL fluid challenge (FC) provided an improved detection of fluid responsiveness, with a specificity of 80.0% and a sensitivity of 91.7%. The area under the ROC curve (AUC) was 0.93 (95% CI: 0.84-1.00, P < 0.001). Fluid administration induced a decrease in Ea from 2.23 (1.46-2.78) mmHg/mL to 1.83 (1.34-2.44) mmHg/mL (P = 0.002), especially for fluid responders in whom arterial pressure did not increase. Notably, the baseline Ea was able to detect the fluid responsiveness with an AUC of 0.74 (95% CI: 0.59-0.86, P < 0.001), whereas Ea failed to predict the pressure response to FC with an AUC of 0.50 (95% CI: 0.33-0.67, P = 0.086).Conclusion:In septic shock patients, a minimal volume of 200 mL 4% gelatin could reliably detect fluid responders. Fluid administration reduced Ea even when CO increased. The loss of arterial load might be the reason for patients who increased their CO without pressure responsiveness. Moreover, a high level of Ea before FC was able to predict fluid responsiveness rather than to detect the pressure responsiveness.Trial registration:ClinicalTrials.gov, NCT04515511

  • 标签: Cardiac output (CO) Fluid challenge (FC) Arterial load Effective arterial elastance (Ea) Septic shock
  • 简介:Abundantfluid-meltinclusionsarefoundintheaegirine-augite-baritepegmatiteandcarbonatiteveinsintheMianningREEdeposit,Sichuan,Theyweretrappedinearlystagefluoriteandquartzfromasalt-meltsystemattemperatureshigherthan5000℃,Meanwhile,fluidinclusionsarealsopresentinalrgeamountsinbastnaesite.Homogenizedbetween150and270℃,theseinclusionsarethoughttoberepresentativeofthephysico-chemicalconditionsofREEmineralization.TheseresultsshowthattheMianningREEdepositisoftypicalhydrothermalorigindevelopedfromasalt-meltsystem.

  • 标签: 流体熔融包裹体 稀土元素矿床 矿化作用 四川 碱性岩浆
  • 简介:Laminarheattransferproblemisanalyzedforadiskrotatingwiththeangularspeedωinaco-rotatingfluid(withtheangularspeedΩ).Thefluidisswirledinaccordancewithaforced-vortexlaw,itrotatesasasolidbodyatβ=Ω/ω=const.Radialvariationofthedisk’ssurfacetemperaturefollowsapowerlaw.Anexactnumericalsolutionoftheproblemisobtainedbasingontheself-similarprofilesofthelocaltemperatureoffluid,itsstaticpressureandvelocitycomponents.NumericalcomputationsweredoneatthePrandtlnumbersPr=1(?)0.71.Itisshownthatwithincreasingβbothradialandtangentialcomponentsofshearstressesdecrease,andtozerovalueatβ=1.Nusseltnumberispracticallyconstantatβ=0(?)0.3(andevenhasapointofamaximuminthisregion);Nudecreasenoticeablyforlargerβvalues.

  • 标签: ROTATING DISK heat transfer FLUID flow
  • 简介:Anewflowtheoryisestablishedthroughtheobjectivityrequirementonthefluiddynamics.Itwasknownthatinhomogeneousfluidmotiongaverisetoviscousforcewhiletheselectionofobserversondifferentspace-timepointswouldchangesuchaninhomogeneouscharacter.Therefore,whentheviscousforcewasconsideredasanobjectiveexistenceforeigntotheselectionofobservers,theforminvariancesofviscousforceandmomentumequationunderlocalrotationtransformationrequiredanewdynamicfield,namelythevortexfieldtobeintroduced.ThenthedynamicalequationsofallflowfieldswereobtainedthroughconstructingtheLagrangiandensityoffluidsystemandusingthevariationalapproachofenergy.

  • 标签: 流体力学 粘滞力 粘滞作用 拉格朗日密度 能量变化近似 Wortex场
  • 简介:WithoutsimplifyingtheN-SequationsofGermano’s,westudytheflowinahelicalcircularpipeemployingperturbationmethod.Athirdperturbationsolutionisfullypresented.Thefirst-second-andthird-ordereffectsofcurvatureкandtorsionтonthesecondaryflowandaxialvelocityarediscussedindetail.Thefirst-ordereffectofcurvatureistoformtwocounter-rotatingcellsofthesecondaryflowandtopushthemaximurnaxialvelocitytotheouterbend.Thetwocellsarepushedtotheouterbendbythepuresecond-ordereffectofcurvature.Thecombinedhigher-order(second-,third-)effectsofcurvatureandtorsion,arefoundtobeanenlargementofthelowervortexofthesecondaryflowatexpenseoftheupperoneandaclockwiseshiftofthecentersofthesecondaryvorticesandthelocationofmaximumaxialvelocity.Whentheaxialpressuregradientissmallenoughorthetorsionissufficientlylargerthanthecurvature,thelocationofthemaximalaxialvelocityisneartheinnerbend.Theequationofthevolumefluxisobtainedfromintegratingtheperturbationsolutionsofaxialvelocity.Fromtheequationthevalidityrangeoftheperturbationsolutionsinthispapercanbeobtainedandtheconclusionthatthethreetermsoftorsionhavenoeffectonthevolumefluxcaneasilybedrawn.Whentheaxialpressuregradientislessthan22.67,thevolumefluxinahelicalpipeislargerthanthatinastraightpipe.

  • 标签: SECONDARY FLOW HELICAL PIPE PERTURBATION method
  • 简介:Theflowcharacteristicsinaspouted-fluidbeddifferfromthoseinspoutedorfluidizedbedsbecauseoftheinjectionofthespoutinggasandtheintroductionofafluidizinggas.Theflowbehaviorofgas-solidphaseswaspredictedusingtheEulerian-Euleriantwo-fluidmodel(TFM)approachwithkinetictheoryforgranularflowtoobtaintheflowpatternsinspouted-fluidbeds.Thegasfluxandgasincidentanglehaveasignificantinfluenceontheporosityandparticleconcentrationingas-solidspouted-fluidbeds.Thefluidizinggasfluxaffectstheflowbehaviorofparticlesinthefountain.Inthespouted-fluidbed,thesolidsvolumefractionislowinthespoutandhighintheannulus.However,thesolidsvolumefractionisreducednearthewall.

  • 标签: 喷动流化床 双流体模型 气固两相流 数值模拟 气体流量 流动特性
  • 简介:Thispaperdescribesanovelsharpinterfaceapproachformodelingthecavitationphenomenainincompressibleviscousflows.Aone-fieldformulationisadoptedforthevapor-liquidtwo-phaseflowandtheinterfaceistrackedusingavolumeoffluid(VOF)method.PhasechangeattheinterfaceismodeledusingasimplificationoftheRayleigh-Plessetequation.Interfacejumpconditionsinvelocityandpressurefieldaretreatedusingalevelsetbasedghostfluidmethod.Thelevelsetfunctionisconstructedfromthevolumefractionfunction.Amarchingcubesmethodisusedtocomputetheinterfaceareaattheinterfacegridcells.Aparallelfastmarchingmethodisemployedtopropagateinterfaceinformationintothefield.Adescriptionoftheequationsandnumericalmethodsispresented.Resultsforacavitatinghydrofoilarecomparedwithexperimentaldata.

  • 标签: 接口 液体 成穴 模特儿 集合函数 粘滞流动
  • 简介:Thepaperstudiestheproblemoffluidflowandfluidshearstressincanaliculiwhentheosteonissubjecttoexternalmechanicalloadingandbloodpressureoscillation.Thesingleosteonismodeledasasaturatedporoelasticcylinder.Solidskeletonisregardedasaporoelastictransverselyisotropicmaterial.Togetnear-realisticresults,boththeinterstitialfluidandthesolidmatrixareregardedascompressible.BloodpressureoscillationintheHaveriancanalisconsidered.Usingtheporoelasticitytheory,ananalyticalsolutionoftheporefluidpressureisobtained.Assumingthefluidincanaliculiisincompressible,analyticalsolutionsoffluidflowvelocityandfluidshearstresswiththeNavier-Stokesequationsofincompressiblefluidareobtained.Theeffectofvariousparametersonthefluidflowvelocityandfluidshearstressisstudied.更多还原

  • 标签: FLUID flow FLUID shear stress transverse
  • 简介:wellposedness问题为一各向异性不可压缩粘滞在3的液体,在向量B附近旋转(t,x):=(b1(t,x),b2(t,x),b3(t,x)),被学习。在同类的案例中的全球wellposedness(B=e3)与在空间B0的足够地快的旋转,?被证明。在不同类的案例中(B=B(t,xh)),在B0的答案的全球存在和唯一,?被获得,如果起始的数据是足够的与水平粘性相比小。而且,我们在一样的函数空格获得解决方案的一致本地存在和唯一。我们也在B2,1获得整齐的繁殖吗?在另外的假设下面,那B仅仅取决于一个水平空间变量。

  • 标签: 各向异性 适定性 流体方程 旋转 不可压缩粘性流体 功能空间
  • 简介:所有液体动态方程在他们的当模特儿的规模下面是有效的,意味着免费路径例如粒子并且意味着Boltzmann方程的碰撞时间规模和NavierStokes(NS)方程的水动力学规模。当前的计算液体动力学(CFD)集中于部分微分方程(PDE)的数字答案,并且它的目的是得到这些管理方程的精确答案。在如此的一个CFD惯例下面,它是难的开发盖住流动物理从的一个统一计划对水动力学运动因为没有能用Boltzmann做光滑的转变到当模特儿的NS的如此的管理方程,连续地可伸缩。液体动力学的学习需要超出传统的数字部分微分方程。出现设计应用程序,例如为近空间的飞行和流动和热转移在的空气车辆设计微设备,确实要求煤气的动力学的概念的进一步的扩大到物理现实,而非传统的可区分的管理方程的更大的域。在当前的阶段,非平衡流动物理很好还没由于适当工具的缺乏被探索了或清楚地理解。不幸地在当前的数字PDE途径下面,它是难的由于有效PDE的缺席开发如此的一个有意义的工具。以便多尺度的构造和类似于构造管理方程的Boltzmann或NS的当模特儿的过程的multiphysics模拟方法,一个数字算法的发展应该基于物理建模的第一个原则。在这份报纸,而不是跟随传统的数字PDE路径,我们介绍为CFD算法开发的作为一个原则的直接建模。因为所有计算与有限房间分辨率在一个discretized空格被进行,要当模特儿的流动物理不得不在网孔尺寸和时间步骤规模被做。这里,CFD是差不多分离数字进化方程的直接构造,在网孔尺寸和时间步骤将玩的地方,在建模的动态角色处理。与在网孔之间的比率的变化,尺寸和本地粒子意味着免费路径,从到水动力学波浪繁殖的运动粒子运输和碰撞的计划愿望俘获流动物理。基于直接建模,流动运动的连续动力学�

  • 标签: 计算流体动力学 直接建模 流体动力学方程 非平衡流动 偏微分方程 平均自由程