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简介：AbstractAs human life expectancy continues to increase and the birth rate continues to decline, the phenomenon of aging is becoming more prominent worldwide. Therefore, addressing the problems associated with global aging has become a current research focus. The main manifestations of human aging are structural degeneration and functional decline of aging tissues and organs, quality of life decline, decreased ability to resist diseases, and high incidence rates of a variety of senile degenerative diseases. Thus far, no ideal treatments have been found. Stem cell (SC) therapies have broad application prospects in the field of regenerative medicine due to the inherent biological characteristics of SCs, such as their plasticity, self-renewal, and multidirectional differentiation potential. Thus, SCs could delay or even reverse aging. This manuscript reviews the causes of human aging, the biological characteristics of SCs, and research progress on age reversal.

简介：and Quarterly Journal of Economics).[5] The median age of authors in the 1980s and 1990s was 36. Scholars over age 50 when their studies are published are a minute fraction of all authors in these journals. Creative economics at the highest levels is mainly for the young. That is as true in the 1990s as it was in the 1960s,The evidence in section I documents the decline in productivity at the sample means. Information on the age-productivity relationship at the extremes of the sample is interesting in its own right and might help shed some light on the possible causes of the apparent decline in productivity with age. The simplest test compares productivity losses among the top early performers with that of the entire sample of economists at elite institutions. Among the top 10% of early producers the mean values of I1,Abstract--Economists' productivity over their careers and as measured by publication in leading journals declines very sharply with age. There is no difference by age in the probability that an article submitted to a leading journal will be accepted. Rates of declining productivity are no greater among the very top publishers than among others

简介：Whereasmuchhasbeenlearnedaboutage-relatedauditorychangesintheinnerear,relativelylittleisknownabouttheagingeffectsonthevestibularpartoftheinnerear-theperipheralvestibularsystem.Herewereviewrelevantliteraturewithregardtotheprevalenceofvestibulardysfunction,vestibularfunctionalandstructuralchangesintheelderly.Theprevalenceofvestibulardysfunctionincreaseswithage.Functionally,asageincreases,VEMPamplitudesdecrease,VEMPthresholdsincrease,VORgainofHITdecreases.Duetothecomplexityofthevestibularsystem,variationsinsubjectageandmeasurementtechniques,findingsinVEMPlatencyandcalorictestsareconflicting.Toaddressthis,adirectmeasureoftheperipheralvestibularsystemshouldbeapplied.Structurally,age-relatedlossinvestibularganglionandotoconiahavebeennoted;haircellchangesarenotwelldefined;whilesubcellularchangesremaintobeexplored.Defininghowtheonsetofvestibulardysfunctioncorrelateswithstructuraldegenerationwillofferinsightsintothemechanismsunderlyingvestibularaging.

简介：and Quarterly Journal of Economics).[5 The median age of authors in the 1980s and 1990s was 36. Scholars over age 50 when their studies are published are a minute fraction of all authors in these journals. Creative economics at the highest levels is mainly for the young. That is as true in the 1990s as it was in the 1960s,The evidence in section I documents the decline in productivity at the sample means. Information on the age-productivity relationship at the extremes of the sample is interesting in its own right and might help shed some light on the possible causes of the apparent decline in productivity with age. The simplest test compares productivity losses among the top early performers with that of the entire sample of economists at elite institutions. Among the top 10%26#37,the decline appears to be quite substantial. Between years 9-10 and 14-15 elite economists as a group lose 29 to 32%26#37

简介：Agingisamultifactorialprocesscharacterizedbydeteriorationsoffunctionalcapacityofvariousorgansandthewholebodyperformance.Exogenousmechanismforagingincludesonsetandprogressofvariousdegenerativediseases,whereasintrinsicmechanismisgovernedbycellulareventswhereincatabolicprocessesexceedthecapacityforrepairandrejuvenation.1Oxygenandnitrogencenteredreactivespecies(ROS)havebeenidentifiedtoplayakeyroleinboththeintrinsicandextrinsicdevelopmentofagingprocesses,termed"freeradicaltheoryofaging".2Duringthepasthalfofcenturymajorprogresseshavebeenmadeinboththeresearchofagingmechanismandclinicalpracticesinage-relateddiseasetreatmentandelderlycare,resultingasteadyimprovementoflongevityandanimpressiveexpansionoftheelderlypopulationamongindustrializedcountryandsomedevelopingcountries.Thistrendwilllikelygrowinthecurrentcentury.

简介：and Quarterly Journal of Economics).[5 The median age of authors in the 1980s and 1990s was 36. Scholars over age 50 when their studies are published are a minute fraction of all authors in these journals. Creative economics at the highest levels is mainly for the young. That is as true in the 1990s as it was in the 1960s,The evidence in section I documents the decline in productivity at the sample means. Information on the age-productivity relationship at the extremes of the sample is interesting in its own right and might help shed some light on the possible causes of the apparent decline in productivity with age. The simplest test compares productivity losses among the top early performers with that of the entire sample of economists at elite institutions. Among the top 10%26#37,the decline appears to be quite substantial. Between years 9-10 and 14-15 elite economists as a group lose 29 to 32%26#37

简介：Theprolongationoflifeexpectancyandthedrasticreductionoffertilityratearetheprimarycauseofanagingworld.Itisprojectedthattheelderly(above65)willincreasewithinthenext25yearsby82%,whereasthenewbornonlyby3%.Despitetheenormousmedicalprogressduringthepastfewdecades,thelastyearsoflifearestillaccompaniedbyincreasingillhealthanddisability.Theabilitytomaintainactiveandindependentlivingforaslongaspossibleisacrucialfactorforaginginhealthanddignity.Therefore,thepromotionofhealthyagingandthepreventionofdisabilityinmen,mustassumeacentralroleinmedicalresearchandmedicalpracticeaswellasintheformulationofnationalhealthandsocialpolicies.Effectiveprogramspromotinghealthandagingwillensureamoreefficientuseofhealthandsocialservicesandimprovethequalityoflifeinolderpersonsbyenablingthemtoremainindependentandproductive.Themostimportantanddrasticgenderdifferencesinagingarerelatedtoorgansandorsystemsdependantorinfluencedbyreproductivehormones.Indistinctiontothecourseofreproductiveaginginwomen,withtherapiddeclineinsexhormonesandexpressedbythecessationofmenses,agingmenexperienceaslowandcontinuousdeclineofhormones.Thisdeclineinendocrinefunctioninvolves:Adecreaseoftestosterone,dehydroepiandrosterone(DHEA),oestrogens,thyroidstimulatinghormone(TSH),growthhormone(GH),insulin-likegrowthfactor-1(IGF-1),andmelatonin.ThisdecreaseisconcomitantwithanincreaseofLHandFSH.Inadditionsexhormonebindingglobulin's(SHBG)increasewithageresultinginfurtherloweringtheconcentrationsoffreebiologicallyactiveandrogens.Interventionssuchashormonereplacementtherapymayprevent,delayoralleviatethedebilitatingconditionswhichmayresultfromsecondarypartialendocrinedeficiency.Primaryandsecondarypreventivestrategiessuchasthepromotionofasafeenvironment,healthylifestyleincludingp

简介：ＴａｓｋｓｆｏｒＣｈｉｎａ’ｓＡｇｉｎｇＰｒｏｇｒａｍｍｅＴｈｅｏｂｊｅｃｔｉｖｅｓｏｆＣｈｉｎａ’ｓａｇｉｎｇｐｒｏｇｒａｍｍｅａｒｅｔｏ“ｐｒｏｖｉｄｅｅｃｏｎｏｍｉｃｓｕｐｐｏｒｔ，ｍｅｄｉｃａｌａｎｄｈｅａｌｔｈｃａｒｅｓｅｒｖｉｃｅｓａｎｄ...

简介：and Quarterly Journal of Economics).[5 The median age of authors in the 1980s and 1990s was 36. Scholars over age 50 when their studies are published are a minute fraction of all authors in these journals. Creative economics at the highest levels is mainly for the young. That is as true in the 1990s as it was in the 1960s,The evidence in section I documents the decline in productivity at the sample means. Information on the age-productivity relationship at the extremes of the sample is interesting in its own right and might help shed some light on the possible causes of the apparent decline in productivity with age. The simplest test compares productivity losses among the top early performers with that of the entire sample of economists at elite institutions. Among the top 10%26#37,the decline appears to be quite substantial. Between years 9-10 and 14-15 elite economists as a group lose 29 to 32%26#37

简介：ThereisuptonownoconstitutivemodelinthecurrenttheoriesofCDMthatcouldgiveadescriptionforthedegradationofagingconcrete.Thetwointernalstatevariablesβandωareintroducedinthispaper.βiscalledcohesionvariableasanadditionalkinematicparameter,reflectingthecohesionstateamongmaterialparticles.ωiscalleddamagefactorformicro-defectssuchasvoids.ThenadamagemodelandaseriesofconstitutiveequationsaredevelopedonContinuumMechanics.Themodelproposedcouldgiveavaliddescriptionforthewhole-course-degradationofagingconcreteduetochemicalandmechanicalactions.Finally,thevalidityofthemodelisevaluatedbyanexampleandexperimentalresults.

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简介：ＴｒｅｎｄｏｆＰｏｐｕｌａｔｉｏｎＡｇｉｎｇｉｎＣｈｉｎａａｎｄｔｈｅｓｔｒａｔｅｇｙＬｉＢａｏｋｕ，ＺｈａｎｇＷｅｎｆａｎⅠ．ＴｈｅｇｅｎｅｒａｌｓｉｔｕａｔｉｏｎａｎｄｔｒｅｎｄｏｆａｇｉｎｇＣｈｉｎａｉｓｂｅｃｏｍｉｎｇａｃｏｕｎｔｒｙｗｉｔｈ...

简介：目的：分析耳郭刺激抗衰老的疗效，寻求一种简便、安全的抗衰老的保健方法。方法：综合分析耳郭刺激与抗衰老的文献报道，从衰老与耳的关系，耳郭抗衰老的刺激方法、临床应用及机理研究等方面进行探讨。结果与结论：耳郭刺激通常选用与五脏相对应的耳穴心、肝、脾、肺、肾及内分泌、皮质下。耳郭刺激，尤其是耳穴贴压和耳郭按摩法，是简便有效的无创伤性保健、治疗方法，应当在抗衰老中起更大作用。

简介：ＰｏｐｕｌａｔｉｏｎＡｇｉｎｇａｎｄＣｏｎｔｒｏｌｏｆＰｏｐｕｌａｔｉｏｎＧｒｏｗｔｈＴｕＰｉｎｇＲａｐｉｄｐｏｐｕｌａｔｉｏｎａｇｉｎｇＷｉｔｈａｂｉｇｄｒｏｐｉｎｆｅｒｔｉｌｉｔｙａｆｔｅｒｔｈｅ１９７０ｓ，ｔｈｅｐｒｏｐｏｒｔｉｏｎｏｆｃｈｉｌ...

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简介：The21stcenturyisthecenturyofpopulationaging.Intheagingprocessofworldpopulationagestructure,populationaginginChinawillshowthecharacteristicsoffast,highlevelsandgeographicalimbalancebetweenurbanandruralarea.Thisgivesoutaproblemtoendowmentinsurancesystem.Thekeypointtosolvetheproblemistheinnovationtoendowmentinsurancesystem.Studiessuggestthatthefocusofinnovationinclude:Firstly,weshouldlocateanendowmentinsurancesystemaccuratelyanddeterminethedirectionofreformandinnovationclearly.Secondly,onthebasisofimprovinginstitutionalmechanismsregulatory,weshouldensuretoincreaseandsustainthevalueofpensions.expenditureandurbanization,whichaggravatestheimbalanceofpopulationandlandurbanization;thirdly,controllingofhouseholdregisteristheprimarycauseoftheslowdevelopmentofpopulationurbanization,however,looseningthispolicyandreformingtheinstitutionswillpromotethedevelopmentofurbanization;lastly,lengtheningtheuseperiodsoffarmlandisgoodforthecoordinativedevelopmentofurbanizationforits'guaranteeeffect',butaperfectmechanismoflandtransfershouldbetakenforthepremise.

简介：Abstract:Thechangingofriceendospermcellduringagingwasinspectedandanalyzedbytissuesectionmethodinthispaper,whichwasconsideredasthemaincausationofthedescendingoftheeatingqualityofagedrice.Aneweffectivemethodofimprovingtheeatingqualityofagedricewasalsocarriedoutthroughenzymatictreatmentwhichwasbasedonthechangingofhistologicalstructureofagedrice.

简介：非完整哀减信息下的劣化结构时变可靠度评估研宄衰减函数的概率分布对结构可靠度的影响；在非完整衰减信息下，对结构的时变可靠度进行评估。1．假定衰减函数服从5种常见的概卒分靠，讨论可靠度分析结果的差异；2．当衰减函数的概率分布（或各概率分布的杖重）未知时，提出平均可靠度的分析方法。假定承载力是允伞相关的随机过程，扯其概率分伟未知的情况下：（1）假定5种常见的概率分布，对结构可靠度进行分析和比较；（2）将时变可靠发的计算公式Taylor展开，转化为关于衰减函数一阶矩和二阶矩的函数，推导平均可靠度的计算方法（公式18）。1．不同的衰减函数概率分布对结构可靠度的影响显学；2．利用本文提出的方法，在衰减函数概率的分伟（或各概率分布的杖重）未知时，可以得出结构可靠度的合理评估。