简介:为在受到飞机紧张条件的一个盘子中的一个中央裂缝的一个问题被调查。我击碎装载的模式被从裂缝在大距离使用的动态压力脉搏创造。为振幅的某个联合和使用的脉搏的持续时间,传给样品的能量有强烈显著的最小,这被发现,意味着与移动离开最佳的价值的脉搏振幅或持续时间,最小的能量为生长很快增加的快克的开始要求了。获得的结果显示优化不同工业过程的能量消费的可能性与骨折连接了。大部分能被获得在例如,钻或跳能量输入在哪儿说明这进程的最大的部分的岩石花费了。观察的效果的大概进一步的调查能使预言节省参数的最佳的能量可能,即为工业设备,例如讨厌的人,磨擦用机器制造的影响的频率和振幅,并且显著地因此减少过程费用。预言能基于折断的媒介的参数被给(材料参数,流行裂缝长度和取向,等等)。
简介:ZouYan,female,researcher,majoringinevidence-basedmedicine,graduatedfromWestChinaSchoolofMedicine,SichuanUniversityandgainedadegreeofMedicalDoctor.Shehadbeenengagedinclinicalworkofobstetricsandgynecologyfortenyears.Currently,sheworksasHeadofWomenClinicalLaboratoryintheScientificResearchInstituteofNationalHealthandFamilyPlanningCommission,andamasterinstructorofDepartmentofObstetricsandGynecologyinPekingUnionMedicalCollege.
简介:Objective:Thepurposeofthismeta-analysisistodeterminewhetherplatingorintramedullarynailing(IMN)foradultdiaphysealboth-boneforearmfractures(BBFF)providesbetterclinicaloutcomes.Methods:MEDLINE,EMBASE,GoogleScholarandTheCochraneLibrarywerecomprehensivelysearcheduntilJuly31,2016.BothretrospectivestudyandprospectivetrailsaboutcomparisonofdualIMNorhybridfixationversusdualplatingfixationinthetreatmentofadultdiaphysealBBFFwereincluded.UsingRevMan5.3software,dataoffunctionalrecovery,theuniontime,operatingtimeandcomplicationwasextractedformeta-analysis.Results:Thepooledanalysisshowedsimilarresultsintheuniontime,functionalrecoveryandtheratesofcomplications,butshowedasignificantdifferenceinoperatingtime.Conclusion:Thismeta-analysisdemonstratessimilarradiographicoutcomes,functionaloutcomesandcomplicationswithplatesorIMNusedinthetreatmentofadultdiaphysealBBFF.IMNfixationforthesefracturesseemstobeanalternativeandeffectivetreatmentwithshorteroperatingtimesandminimallyinvasive.
简介:Anationallyrepresentativesampleof1640Chineseurbanadolescents(meanage=14.5years)andtheirparentsandteachersweresurveyedtoexaminetheassociationsbetweenrelationshipswithteachersandparentsandadolescents'developmentaloutcomessuchasacademicperformance,psychologicalwell-being,altruisticbehaviors,andmisconduct.Resultsshowedthatthequalityofadolescents'relationshipswithteacherswashighlycorrelatedwithadolescentoutcomes,inmostcasesmoresothanforrelationshipswithparents.Furthermore,suchassociationswerethesameacrossbothgendersandthreegradelevels.ThesefindingssuggestthatteachersmayplayanespeciallysignificantroleinChineseadolescentdevelopment.Thisstudyaddstothesmallbutgrowingliteratureontheimportanceofteachersaswellasothernon-parentaladultsinadolescentpsychosocialdevelopment.
简介:AbstractThe Hoffa fracture is an uncommon fracture. There is a lot of confusion about its diagnosis and management with several conflicting reports in literature. We reported a 25-year-old patient with non-union of Hoffa fracture, and meanwhile tried to develop an algorithm-based treatment for Hoffa fractures. A systematic review of the available literature was performed. Medline, Embase, the Cochrane Library and PubMed were searched for relevant articles. Fifty-five articles were reviewed, and the clinical knowledge base was summarized. The understanding of the mechanism of trauma has become more nuanced. The literature has also evolved to classify the fracture with the purpose of surgical management in mind. This can be used to plan approach and fixation with preservation of blood supply. Classification can also prognosticate the outcomes in Hoffa fracture.
简介:WeusedBastianimonoarmexternalframefixatortofixopentibialfracture,acompositeflaptransfertocoverandrepairthedefectsoftheskinandanirrigationdevicetodrainthewoundareainpatientswithinfectedopentibialfracturesinducedbyinternalfixation.Satisfactoryfunctionwasobtainedandthecosmeticresultsofboththedonerandthereceptorsiteswerealsosatisfactoryafteroperation.
简介:客观:为王牌探索起作用的指示和主要全部的新潮的关节造形术的起作用的方法平坦骨折并且观察临床的药品effect.Methods:我们回顾地总结了并且分析创伤的条件,破裂类型,复杂并发症,起作用的时间,起作用的技术,和11patients的短期的药品效果(10男性和1女性,与42的吝啬的年龄。4年)与王牌平坦骨折经历了主要全部的新潮的关节造形术。结果;病人被跟随在上面为6-45月(吝啬的=28月)。他们手术后的新潮的关节的普通哈里斯分数是78。结论:指示的Understrict控制,有平坦骨折可以经历的王牌的病人主要全部的新潮的关节造形术,而是稳定的王牌平坦部件应该被做。
简介:Fracturetoughnessisoneofthecrucialmechanicalpropertiesofbrittlematerialssuchasglassesandceramicswhichdemonstratecatastrophicfailuremodes.Conventionalstandardizedtestingmethodsadoptedforfracturetoughnessdeterminationrequirelargespecimenstosatisfytheplanestraincondition.Asforsmallspecimens,indentationisapopular,sometimesexclusivetestingmodetodeterminefracturetoughnessforitcanbeperformedonasmallflatareaofthespecimensurface.Thisreviewfocusesonthedevelopmentofindentationfracturetheoriesandtherepresentativetestingmethods.Crackingpatterndependentonindentergeometryandmaterialpropertyplaysanimportantroleinmodeling,andisthemainreasonforthediversityofindentationfracturetheoriesandtestingmethods.Alongwiththesimplicityofspecimenrequirementisthecomplexityofmodelingandanalysiswhichaccountsforthesemi-empiricalfeaturesofindentationfracturetests.Someunresolvedissuesshapingthegapbetweenindentationfracturetestsandstandardizationarealsodiscussed.更多还原
简介:Objective:Toevaluatetheeffectofosteoporosisonfracturehealingthroughobservingthehistomorphologicalchanges,bonemineraldensityofcallusandexpressionanddistributionoftransforminggrowthfactorbeta1(TGF-β1),basicfibroblastgrowthfactor(bFGF)andbonemorphogeneticprotein-2(BMP-2)inovariectomizedrats.Methods:SixtyfemaleSprague-Dawleyrats(aged12weeksandweighing235gonaverage)wererandomlydividedintoanovariectomized(OVX)group(n=30)andasham-operated(SO)group(n=30).OvariectomywasperformedintheOVXratsandsameincisionwasmadeintheSOrats.Threemonthslater,fractureoffemoralshaftwasmadeonalltherats.Thentheywerekilledatdifferenttimepoints.Callusformationwasobservedwithhistologicalandimmunohistochemicalmethods.Results:AreductionincallusandbonemineraldensityinthehealingfemurandadecreaseofosteoblastsexpressingTGF-β1nearthebonetrabeculawereobservedintheOVXrats3-4weeksafterfracture.HistomorphologicalanalysisrevealedahighercontentofsoftcallusintheOVXratsthanthatintheSOrats.ImmunohistochemistryresultsshowedthatnoremarkabledifferenceinexpressionanddistributionofBMP-2andbFGFbetweentheOVXandSOgroupswasfound.Conclusions:Osteoporosisinfluencesthequantityandqualityofcallusduringtheearlyperiodoffracturehealing.TheeffectofosteoporosisonfracturehealinghasnorelationshipwiththeexpressionofBMP-2orbFGF.ThedecreasedexpressionofTGF-β1inosteoblastsmaycauseadecreaseinqualityoffacturehealingafterosteoporosis.
简介:Mechanicalandelectricaldamagesareintroducedtostudythefracturemechanicsofpiezoelectricceramicsinthispaper.Twokindsofpiezoelectricfracturecriteriaareestablishedusingthemethodofleastsquarescombinedwithadamageanalysisofthewell-knownpiezoelectricfractureexperimentsofParkandSun's.Oneisbasedonalinearcombinationofthemechanicalandelectricaldamagesandtheotherontheirnonlinearcombination.WhenthecombineddamageDisuptoitscriticalvalueDc,piezoelectricfractureoccurs.Itisfoundfromthequalitativecomparisonofthenumericalresultswiththeexperimentaldatathatthenonlinearlycombineddamagefracturecriterioncangiveabetterpredictionofpiezoelectricfracture.Anditisconcludedfromthenonlinearlycombineddamagefracturecriterionthatanegativeelectricfieldimpedesfracturewhereastheeffectofapositiveelectricfieldonfracturedependsonitsmagnitude.
简介:Thisinvestigationdiscussesfurthertheextenttowhichanewdamagetheoryrecentlyproposedbytheauthorcanserveasaunifiedtheorytocharacter-izevariousductilefailureproblems.Ageneraldamageintegralandcorrespondingcriterionforductilefracturearepresented.Anewparameterforductilefractureisemphasized,whichisexperimentallyverifiedasamaterialconstantindependentofstressstate,hasclearphysicalmeaning,andcaneasilybedetermined.Theapplica-bilityofthistheorytoevaluationoftheductilityofweldsandengineeringmaterialsundervariousconditionsisexamined.Also,itisusedtopredicttheeffectofresid-ualstressonfailureofwelds,topredictsheetforminglimits,andtocorrelatethevariabilityofelasto-plasticfracturetoughnessvaluesJ1candδcwithdifferentspec-imengeometries.Anewconstraintcorrectionmethodisproposed,andconstraintcorrectednewtoughnessparametersJdcandδdcarerecommended.Experimentshaveshownthatthetoughnessvariationwithdifferentspecimengeometriescanef-fectivelyberemovedbyuseofthemethod.Thegeneralapplicabilityofthetheorytocharacterizationofvariousductilefailuresprovidesanewdesigntoolforengineeringcomponentsorstructures.
简介:当他们被使遭到影响时,在自然鱼眼石晶体的破裂坚韧上结果被介绍。裂缝和骨折的形态学被学习了。裂缝形成不显示出任何各向异性的性质并且仍然是可以是水晶的取向的一样,这被发现。破裂坚韧K//c和易碎物的平均价值索引,从裂缝长度的大小决定了被估计是0.107g亩m**减**3**/**2和4.19亩m**减**1**/**2分别地为一(100)飞机。收益力量为一(100),P(111)和C(001)为更低的负担的鱼眼石晶体的飞机是2250,2160和1840MPa并且分别地为更高的负担是1510,1600和1430MPa。(编辑作者摘要)7个裁判员。
简介:Thispapergivesemphasisontheresearchoftheproblemoflocalheadlossofcrossfractureflowbyalotofmodelexperiments,andatheoreticalmodeloflocalheadlossofcrossfractureflowisfoundedbyuseofthemomentumlawofwaterflow.Throughthecorrelationanalysisbetweenmodelexperimentalresultsandtheoreticalmodel,thecorrectioncoefficientoftheoreticalmodelisdefinite.Theproposedcalculationformulaoflocalheadlossofcrossfractureflowcanbeusedtoanalyzetheproblemofnetworkfractureseepage.
简介:客观:为了调查与外部fixator在处理期间测量主要axials火车的不同方法并且发现,合适的压缩在一个早阶段由外部fixator装载了。方法:十八只健康大耳朵的兔子随机根据不同测量方法被划分成二个组:组织A和组B。在组A,一个紧张计量器与502胶水在外部胫骨的外皮被加,并且在组B,一个骨头cement-coatedstrain计量器在内部胫骨的外皮上被安装。组A和B被划分成二亚群A1,A2和B1,B2,分别地根据一半并且与身体重量一样的压力。Z塑造左中间柄的胫骨的截骨术被externalfixator执行并且修理。结果:组A的sealer曲线在早阶段期间戏剧性地变化了。当后者紧张价值比前者高时,内部、外部的外皮的Thetrendlines在到达稳定的阶段以后一致地去了。到达最稳定的年龄的组B的时间是短的,但是它的绝对紧张价值是不到组A的。在他们被贴在稳定的阶段以前,当亚群B1和B2的结果是一样的时,亚群A1的拒绝的速度比SubgroupA2的慢慢地是更多。在它衰退了以后,当时,组A有一个上升趋势组Bdidn“t。在他们到达了稳定的阶段,两亚群A1和A2had以后一个衰退趋势当亚群A2比亚群A1快速是更多时,当亚群B2波动时,亚群B1在明确的水平被保留。结论:在外部fixatorcan下面的轴的紧张被骨头水泥测量在vivo的涂紧张的计量器。数据可以建议身体重量负担的那一半对外部fixator合适。
简介:Inthispapertheresultsofahigh-speedtensionexperimentoftheSiC_w/Alcompositehavebeenreportedandasimplifiedtheoreticalmodelhasbeendevelopedtostudythefracturemechanismofcompositesinhigh-speedtension.Thistheoreticalmodelprovidesanewexplanationfortheincreaseofdynamicfracturestrengthofcompositesinhigh-speedtension.
简介:AbstractBackground:Although there are few studies mentioned there may be some relationship between psoriatic arthritis (PsA) and osteoporosis, clinical data in real world still need to be clarified in China. The aim of this study was to assess the areal and volumetric bone mineral density (BMD), frequency of fracture, and risk factors in patients with PsA.Methods:A total of one hundred PsA patients who visited Peking University First Hospital and one hundred age- and sex-matched healthy controls with DXA data were enrolled in the study. Patients with clinical fractures confirmed by X-ray during follow-up were also recorded. Clinical characteristics of the patients were recorded and compared between the abnormal BMD group and the normal BMD group, as well as between the fracture and non-fracture groups. Risk factors for fracture and low BMD were analyzed.Results:Mean BMD at the total hip and femoral neck was significantly lower in PsA patients than that in healthy controls (0.809 ± 0.193 vs. 0.901 ± 0.152 g/cm2, P = 0.041; 0.780 ± 0.146 vs. 0.865 ± 0.166 g/cm2, P = 0.037, respectively). Moreover, lumbar spine BMD was negatively correlated with psoriasis duration, swollen joint count and DAS28-CRP (r = -0.503, -0.580, -0.438; P < 0.05). Total hip BMD and femoral neck BMD were negatively correlated with HAQ (r = -0.521, -0.335; P < 0.05). Fractures occurred in 29 patients during the follow-up period. Logistic regression analysis showed that older age (OR 1.132 [95% CI: 1.026-1.248), P < 0.05], higher HAQ score (OR 1.493, 95%CI: 1.214-1.836, P < 0.01), higher disease activity index for psoriatic arthritis (OR 1.033, 95% CI: 1.002-1.679, P < 0.05) and hip joint involvement (OR 6.401, 95% CI: 4.012-44.180, P < 0.05) were risk factors for fracture in the multivariate model.Conclusions:Increased risks of osteoporosis and fracture were found in PsA patients compared to healthy controls. Besides age, high disease activity and hip joint involvement were risk factors for decreased BMD and fracture.