简介:Weinvestigatetheinteractionbetweenapositivemassandanegativeeffectivemassthroughathreemasschainconnectedwithelasticsprings,apairofmassesisdesignedtohaveaneffectivenegativemass,anditinteractswiththethirdpositiveoneasifanequivalenttwo-masschain.Thedynamicsoftheequivalenttwo-masschainshowsthatthetwobodiesmaybeself-acceleratedinsamedirectionwhentheeffectivemassbecomesnegative,theexperimentisalsoconductedtodemonstratethistypeofmotion.Wefurthershowthattheenergyprinciple(Hamilton’sprinciple)isapplicableiftheenergyofthenegativemassunitisproperlycharacterized.Theresultmayberelevanttocompositewithcellsofeffectivenegativemass,theirinteractionwithmatrixmayleadtomorericherunexpectedmacroscopicresponses.
简介:Purpose:Theaimofthisstudywastoanalyzeandcomparetheeffectsofdifferentsports(swimming,football,basketball,andhandball)onfatmassandleanmassinprepubertalandpubertalgirls.Methods:Twohundredgirls(10.6±1.5yearsold,TannerstagesI–III)participatedinthestudyandweredividedinto5groups:40swimmers,40footballplayers,40basketballplayers,40handballplayers,and40controls.Fatandleanmassesatwholebody,arms,trunk,andlegsweremeasuredusingdual-energyX-rayabsorptiometry(DXA).PubertalstatuswasdeterminedusingTannertest.Effectsofdifferentsportsonfatandleanmasseswereassessedthroughanalysisofcovariancewithheightascovariates.Analyseswereperformedseparatelyin2groupsdependingontheTannerstage(prepubertalandpubertal).Results:Thegirlsofthecontrolgrouphadlessleanmassandmorefatmasscomparedtothegirlswhoplaysports(p<0.05).Thereweredifferencesinbodyfatbetweensports.Theswimmersandfootballplayershadlessbodyfat(p<0.05).Ontheotherhand,handballplayersshowedthehighestvaluesinleanmass(p<0.05).Conclusion:Impactsports(football,basketball,andhandball)andlow-impactsports(swimming)provideanappropriatedevelopmentofleanmassingrowinggirls.Wecanconcludethatpeoplepracticingsportsatearlyagesensurealowerfatmassandhigherleanmasscomparedtothosewhodonotpractice.Theseresultsmaybeusefulasapreventivemethodofadultobesity.
简介:AbstractBackground:Invasive sphenoid sinus aspergillosis is a rare but life-threatening condition usually found in immunocompromised patients. When involving cavernous sinus and surrounding structures, patients are frequently misdiagnosed with a neoplasm or sellar abscess. Timely diagnosis and intervention are crucial to patients’ outcomes. The objective of this study is to review cases of invasive sphenoid sinus aspergillosis to describe disease manifestations, imaging features, treatment, and outcome.Case presentation:We describe four patients with invasive sphenoid sinus aspergillosis misdiagnosed as sellar tumors preoperatively. The mass was completely removed in three patients and partially removed in one patient microscopically. Pathological examinations confirmed Aspergillus in all cases. All four patients received anti-fungal agents postoperatively. There was no recurrence at the time of each patient’s follow-up date. One patient with complete resection was lost to follow-up while the other three patients’ neurologic function improved. Additionally, we performed a systematic review regarding invasive sphenoid sinus aspergillosis of existing English literature.Conclusion:With regard to clinical symptoms, headache, vision impairment, and ophthalmoplegia were observed in over half of the patients in the literature. A sellar mass with bone destruction on CT and involvement of cavernous sinus is highly suggestive of invasive fungal sphenoid sinusitis. Immediate surgical removal of the lesion is recommended for invasive sphenoid sinus aspergillosis to preserve nerve function and increase the likelihood of survival.
简介:AbstractBackground:Invasive sphenoid sinus aspergillosis is a rare but life-threatening condition usually found in immunocompromised patients. When involving cavernous sinus and surrounding structures, patients are frequently misdiagnosed with a neoplasm or sellar abscess. Timely diagnosis and intervention are crucial to patients’ outcomes. The objective of this study is to review cases of invasive sphenoid sinus aspergillosis to describe disease manifestations, imaging features, treatment, and outcome.Case presentation:We describe four patients with invasive sphenoid sinus aspergillosis misdiagnosed as sellar tumors preoperatively. The mass was completely removed in three patients and partially removed in one patient microscopically. Pathological examinations confirmed Aspergillus in all cases. All four patients received anti-fungal agents postoperatively. There was no recurrence at the time of each patient’s follow-up date. One patient with complete resection was lost to follow-up while the other three patients’ neurologic function improved. Additionally, we performed a systematic review regarding invasive sphenoid sinus aspergillosis of existing English literature.Conclusion:With regard to clinical symptoms, headache, vision impairment, and ophthalmoplegia were observed in over half of the patients in the literature. A sellar mass with bone destruction on CT and involvement of cavernous sinus is highly suggestive of invasive fungal sphenoid sinusitis. Immediate surgical removal of the lesion is recommended for invasive sphenoid sinus aspergillosis to preserve nerve function and increase the likelihood of survival.
简介:Splenosisistheautotransplantationofsplenictissuethatusuallyfollowstraumaticruptureofthespleen.Splenicimplantsmaybeseededwithinorbeyondtheperitonealcavity.1Themostfrequentlocationsofsplenosisinthedescendingorderaretheserosalsurfaceofthesmallintestine,thegreateromentum,parietalperitoneum,surfaceofthelargeintestine,mesentery,undersurfaceofthediaphragmandthethorax.1,2However,intrahepaticsplenosisisveryrare.Werecentlyencounteredapatientinwhomresultsofultrasonography(US)andcomputedtomography(CT)revealedanintrahepaticmassthatconsistedofectopicsplenictissue.Toourknowledge,thisisthefifthreportofectopicsplenictissueintheliverintheEnglish-languageliterature.Wepresenttheimagingfindingsofthesplenicimplantsintheliveranddiscussthediagnosisanditspracticalsignificance.
简介:本文阐释了大众消费主义在美国的兴起以及向全球,特别是中国传播的历史。论文第一部分考察了20世纪初期美国大众消费主义的特征以及随着消费主义开始重塑美国人的生活而引发的争论,认为美国消费主义的兴起实际上与美国人对丰裕社会中生产过剩问题的担心有关,同时也是不断扩大市场的需要。第二部分考察了美国大众消费品向海外的出口、美国形象的输出以及随之而来的关于美国化的争论。在第三部分,作者认为,美国的消费主义模式在输出过程中逐渐适应当地的社会与文化,到20世纪70和80年代,世界各地的消费主义实际上越来越多样化,人们不再像过去那样把消费主义的扩张等同于美国化,相反,消费主义被认为是一种支持,而不是消弱了国家和个人身份多样性的现象。实际上,正是这种多元地方消费主义的扩张在一定程度上促进了冷战的结束。作者在结论中指出,关于大众消费主义的争论在世界各地仍然在继续,但争论的焦点不再是对"美国化"或"文化帝国主义"的恐惧,而更关注环境的可持续性和财富的分配等问题。尽管大众消费主义可以在全球范围内通过适应不同地区的文化而产生强大的吸引力,但它所反映的仍然是20世纪初期美国人的观念,而这一观念越来越落后于时代,那就是:在一个资源丰裕的世界里,需要不断地刺激人们的欲望和需求。
简介:ThepresentpaperconcernsitselfwithageneralreviewandanalysisofBritishmassMedia.ThefirstpartstartswithanintroductiontothehistoryanddevelopmentofBritishmassmedia.ThesecondpartwillfocusontheanalysisofthetwomajorbranchesintherealmofBritishMassmedia-theBroadcastMediaandthePrintMedia.Thirdly,theBritishmedia’scoverageofBeijingOlympicsispresentedtohaveabetterknowledgeofthewellacceptedclassificationofUKmassmedia,especiallynewspapersandtelevisionaswellasitsinfluence.
简介:Objective:Toevaluatetheassociationbetweenobesityandtheriskofcolorectalcancer.Methods:331patientswithrectalcancerand175withcoloncancerwhoacceptedsurgicaloperationatBeijingCancerHospitalduring1995and2002wereenrolled.Datawerecollectedbyreviewingthepathologymaterialsandhospitalrecords.258healthypeoplewhoacceptedhealthexaminationatBeijingCancerHospitalduring2000and2002werealsoenrolledascontrol.Dataofheight,weightandgenderatthetimeofexaminationwerealsocollected.Obesitywasestimatedbybodymassindex(BMI),computedasweightinkilogramsdividedbyheightinmeterssquared(kg/m2).ThedegreeofobesitywascomparedbetweenthetwogroupsusingBMI(18.5,24-27.9and(28(kg/m2)asthecut-offpointsforunderweight,overweightandobesity.Associationswithobesitywereestimatedbyoddsratios(ORs)and95%confidenceintervals(CIs).AllORswereadjustedforageandsex.Results:Obesitywassignificantlyprevalentinfemalepatientswithrectalcancer.AllthepatientswithcoloncancershowedlowerlevelofBMIthancontrolsubjects.TheORsforrectalcancerrosewithincreasingBMIinwomen.Meanwhile,theORsforcoloncancerdroppedwithincreasingBMIinbothmenandwomen.Obesitywasanindependentriskfactorforrectalcancer,butnotanindependentriskfactorforcoloncancer.Conclusion:Rectalcancerandcoloncancermayhavedifferentbiologicalbehavior.Obesewomenhaverelativelyhighriskforrectalcancer.
简介:ComparisionofFABandMALDIMassSpectrometryofGinsenosides¥ZhouYu;LiuZhiqiang;SongFengrui;LiuShuying;LiXianggao;YinJiangyuan(1Cha...
简介:Thereisanincreasingnumberof'massevents'inmainlandChina.MystudyextendsthecurrentstudiestothecontextofChinaandtriestoexaminethepotentialimpactsofclimatechangesonhumanconfliasinChina.Theresultssuggestastronglinkagebetweenthedeviationofmonthlymeantemperaturefromthehistoricalmeanandthenumberofmasseventsinaprovince.Ifthecurrenttrendofwarmingpersists,inthenext6-8decades,thenumberofmasseventsinChinawillincreasebyover8.8%.