学科分类
/ 1
8 个结果
  • 简介:有部分微分方程的优化问题在科学和工程的许多区域广泛地作为限制产生,特别地处于设计的问题。抑制PDE的优化问题的如此的类的解决方案通常是一项主要计算任务。因为为直接寻求抑制PDE的优化问题的答案的肤色,我们由使用Galerkin把它转变成僵绳点形式的线性方程的一个系统有限元素的discretization。为discretized线性系统,在这份报纸,我们构造一块对称并且block-lower-triangularpreconditioner,为解决抑制PDE的优化问题。两preconditioners利用系数矩阵的结构。为相应preconditioned矩阵的特征值和特徵向量的明确的表情被导出。当规则化参数是合适小的时,数字实现证明这些块preconditioners能为preconditionedGMRES方法导致令人满意的试验性的结果。[从作者抽象]

  • 标签: 约束优化问题 预条件 下三角 对称 PDE Galerkin
  • 简介:ScientistsattheUniversityofPittsburghSchoolofMedicinehavediscoveredanewbiologicalpathwayofinnateimmunitythatrampsupinflammationandthenidentifiedagentsthatcanblockit,leadingtoincreasedsurvivalandimprovedlungfunctioninanimalmodelsofpneumonia.TheyreportedtheirfindingstodayinNatureImmunology.

  • 标签: 研究人员 免疫蛋白 炎症 匹兹堡大学 爬升 代理
  • 简介:在一个二维的方形的数组的螺线波浪的开发由于部分离子隧道块(钾,钠)被调查,节点的动力学被HodgkinHuxley神经原描述,这些神经原最近被结合邻居连接。参数比率xNa(并且xK),它定义钠(钾)的工作离子隧道数字的比率到钠的全部的离子隧道数字(并且钾),被用来测量隧道块导致的移动传导力。在二参数的阶段空间(参数比率对毒害的区域)的统计可变R的分发广泛地被计算为部分离子隧道块导致的螺线波浪的转变标记参数区域,有同步R的更小的因素的区域被联系那个螺线波浪使明白毒害的隧道、柔韧的参数区域。当毒害的区域(钾或钠)和沉醉的度是小的时,螺线波浪保持活着,不同转变(死亡,几个螺线波浪共存或多手臂螺线波浪出现)发生在中等比率xNa下面(并且xK)当堵住的区域的尺寸超过某些阀值时。螺线波浪的决裂发生,螺线的多手臂飘动当隧道噪音被考虑时,被观察。

  • 标签: 诱导作用 螺旋波 子信道 神经元 Wave 死亡
  • 简介:Thewaltzingguineapigmaybeagoodmodeltoinvestigateifgeneticfactorcanchangethesensitivityinnoise-inducedhearingloss.Atotalof34waltzigguineapigswerestudiedandwefoundthatthereisnoanysignificantincreasedsensitivitytonoisetraumaiftheage-inducedhearinglosswasconsideredinwaltz-ingguineapig.

  • 标签:
  • 简介:BackgroundLeftbundlebranchblock(LBBB)resultsinanalteredpatternofleftventricular(LV)activationandsubsequentcontraction.CardiacsynchronyandcardiacfunctionaredeterioratedbyLBBB.However,theeffectofLBBBhistoryonprogressiveheartdysfunctionandclinicalefficacyofcardiacresynchronizationtherapy(CRT)insuchpatientsarenotclear.InthisstudyweexploretheclinicalefficacyandpredictorofcardiacresynchronizationtherapyinLBBBheartdysfunction.MethodsTwenty-sevenLBBBpatientswithsevereheartfailureweretreatedwithCRT.Twenty-sixLBBBpatientswithoutCRTservedascontrol.During6monthsfollow-up,ECG,plasmaNT-proBNPandechocardiogramindexesweremeasured.ResultsComparedwithbaseline,NYHAfunctionalclassof23patients(85.2%)wasimprovedinCRTgroup.Comparedwithbaselineandcontrol,QRSduration(QRSd)wassignificantlymorenarrow(P=0.023,P=0.019),NT-proBNPwassignificantlylower(P=0.011,P=0.009),ventricularseptaltoleftventricularposteriorwalldelaytimeandleftventriculardyssynchronyindex(Ts-SD)weresignificantlyworse(P<0.05);leftventricularejectionfraction,leftventricularend-systolicvolume,mitralregurgitationareaweresignificantlyimprovedinCRTgroup(P<0.05).whentheLBBBhistorywas≥2yearsandQRSd≥155ms,thesensitivityandspecificityofCRTsuper-responsewere53.4%and85.6%respectively.ConclusionsCRTcanimprovethesynchronizationandhemodynamicofLBBBpatientswithheartdysfunction,theLBBBhistory≥2yearsandQRSd≥155msareoneoftheCRTsuper-responsepredictors.

  • 标签: 心脏功能 临床疗效 预测因子 功能障碍 传导阻滞 再同步
  • 简介:Lamellarcrystalsofdiblock,triblockandfour-armpoly(ethyleneglycol)-b-poly(ε-caprolactone)(PEG-b-PCL)crystalline-crystallinecopolymersweresuccessfullyobtainedfromtheirsolution.Morphologyandstructureoflamellarcrystalsofcrystalline-crystallinecopolymerswereinvestigatedusingtapping-modeatomicforcemicroscopy(AFM)andselectedareaelectrondiffraction(SAED).Allofthesesamplesshowedthetruncated-lozengemultilayerbasalshapeswithcentralscrewdislocationorcentralstack,whichwereallobtainedsimultaneouslyfromtheoilbath.ThediffractionpatternofPEGblocklamellarcrystalisattributedtothe(120)diffractingplanesandthepatternofPCLblocklamellarcrystalisattributedtothe(110)diffractingplanesand(200)diffractingplanesaccordingtotheSAEDresults.Four(110)crystalgrowthplanesandtwo(200)crystalgrowthplanesarediscoveredforthePCLblocks,butthe(120)crystalgrowthplanesofPEGblocksarehidedinthefigureofAFM.Thecrystallinestructureofthefour-armcopolymers(FA)ismoredisorderandconfusedthanthatofthediblock(DI)copolymerandthestriatedfoldsurfacestructuresoflamellarcrystalsoffour-armcopolymers(FA)aresmootherthantheseoflinearanalogues,owingtotheconfusedcrystallizationofblockscausedbythemutualrestrictionofblocksandthehindranceofthedendriticcores.Inaddition,theaspectratioofFAisgreaterthanthatoftheothers.Itishypothesizedthattherearetworeasonsforthechangeofaspectratios.First,the(200)diffractingplanesofPCLcrystalsgrewslowlycomparedtotheir(110)diffractingplanesbecauseofdifferenceintheenergybarrier.Secondly,edgedislocationsonthe(200)diffractingplanesarealsoresponsibleforthevariationoftheaspectratio.Consequently,thecrystallinedefectsareaugmentedbythecompetingblockscrystallizedsimultaneouslyandthehindranceofthedendriticcores.

  • 标签: 嵌段共聚物 结晶行为 Ε-己内酯 乙二醇 线性 溶液