Effect of Organophilic Montmorillonite on Thermal-oxidative Aging Behavior of SBS Modified Bitumen Crack Filling Material

Styrene-butadiene-styrene （SBS） modified bitumen crack filling material with organophilic montmorillonite （OCFM） was prepared by melt blending. X-ray diffraction analysis shows that the interlayer spacing of organophilic montmorillonite （OMMT） in OCFM is widened and an exfoliated structure may be formed. Thermal-oxidative aging behavior of OCFM and SBS modified bitumen crack filling material （SCFM） was investigated. The experimental results indicate that the rate of thermal-oxidative aging of OCFM is much slower than that of SCFM, which can be attributed to barrier of exfoliated structure of OCFM to oxygen.

Effects of thermal-oxidative aging on rheological properties of montmorillonite modified bitumen

Organic montmorillonite(OMMT) modified bitumen nanocomposites was prepared by melt blending.The effects of thin-film oven test(TFOT) and pressure ageing vessel(PAV) on rheological properties of pristine bitumen and OMMT modified bitumen were investigated by dynamic shear rheometer(DSR).The results show that complex modulus(G*) increases,phase angle(δ) decreases and rutting factor(G*/sin δ) is enhanced for the pristine bitumen after TFOT,whereas G*,δ and G*/sin δ of OMMT modified bitumen have a little change before and after TFOT.Besides,the pristine bitumen exhibits a large increase of G* and a great decrease of δ after PAV aging.However,the changes in G* and δ of OMMT modified bitumen are small before and after PAV.Compared with the pristine bitumen,OMMT modified bitumen presents a lower fatigue factor(G*sin δ) after PAV.As a consequence,resistance to thermal-oxidative aging of bitumen is remarkably improved due to the introduction of OMMT.

Thermal-oxidative aging performance and lifetime of hydrogenated nitrile rubber prepared by in situ hydrogenation at the latex stage

Hydrogenated nitrile rubber(HNBR)was prepared by selective hydrogenation of nitrile-butadiene rubber latex using hydrazine hydrate/hydrogen peroxide catalytic system,which effectively resolved the problems with environment pollution and high cost caused by noble metal catalyst via solution hydrogenation method.Because of the saturation of carbon-carbon double bonds after hydrogenation,HNBR presented excellent thermal-oxidative aging resistance.The thermaloxidative activation of HNBR prepared in situ was investigated by thermogravimetric analysis(TGA)and Flynn-Wall-Ozawa method.Meanwhile,the microstructure and mechanical properties of HNBR was studied during the thermal-oxidative aging process.The relationship between lifetime and aging temperature was evaluated as well as the thermal-oxidative aging coefficient of HNBR,which provided theoretical basis for the application of HNBR under the high temperature and in harsh environment.

Improving Thermal-oxidative Aging Resistance of Styrene-butadiene Rubber by Antioxidant Loaded Silica Aerogel

The antioxidant N-isopropyl-N'-phenyl-p-phenylenediamine(4010NA)was dissolved in ethanol and impregnated into silica aerogel(SAG)via vacuum-pressure cycles,yielding composite particles(A-N)with enhanced sustained-release and reinforcing capabilities.The effect of A-N on the mechanical properties and thermal-oxidative aging resistance of styrene-butadiene rubber(SBR)vulcanizates was investigated.TGA and BET assessments indicated that the loading efficiency of 4010NA in SAG reached 14.26%within ethanol's solu bility limit.Incorporating A-N into SBR vulcanizates significantly elevated tensile strength by 17.5%and elongation at break by 41.9%over those with fumed silica and free4010NA.Furthermore,A-N notably enhanced the thermal-oxidative aging resistance of SBR.After aging for 96 h at 100℃,the tensile strength and elongation at break of SBR with A-N sustained 70.09%and 58.61%of their initial values,respectively,with the retention rate of elongation at break being 62.8%higher than that of SBR with fumed silica and free antioxidant.The study revealed that A-N composite particles significantly inhibited the crosslinking in SBR's molecular chains,reducing hardening and embrittlement during later thermal-oxidative aging stages.

Effects of Maillard reaction and its product AGEs on aging and age-related diseases

Maillard reaction(MR)is a non-enzymatic browning reaction commonly seen in food processing,which occurs between reducing sugars and compounds with amino groups.Despite certain advantages based on Maillard reaction products(MRPs)found in some food for health and storage application have appeared,however,the MR occurring in human physiological environment can produce advanced glycation end products(AGEs)by non-enzymatic modification of macromolecules such as proteins,lipids and nucleic acid,which could change the structure and functional activity of the molecules themselves.In this review,we take AGEs as our main object,on the one hand,discuss physiologic aging,that is,age-dependent covalent cross-linking and modification of proteins such as collagen that occur in eyes and skin containing connective tissue.On the other hand,pathological aging associated with autoimmune and inflammatory diseases,neurodegenerative diseases,diabetes and diabetic nephropathy,cardiovascular diseases and bone degenerative diseases have been mainly proposed.Based on the series of adverse effects of accelerated aging and disease pathologies caused by MRPs,the possible harm caused by some MR can be slowed down or inhibited by artificial drug intervention,dietary pattern and lifestyle control.It also stimulates people's curiosity to continue to explore the potential link between the MR and human aging and health,which should be paid more attention to for the development of life sciences.

Microglial response to aging and neuroinflammation in the development of neurodegenerative diseases

Cellular senescence and chronic inflammation in response to aging are considered to be indicators of brain aging;they have a great impact on the aging process and are the main risk factors for neurodegeneration.Reviewing the microglial response to aging and neuroinflammation in neurodegenerative diseases will help understand the importance of microglia in neurodegenerative diseases.This review describes the origin and function of microglia and focuses on the role of different states of the microglial response to aging and chronic inflammation on the occurrence and development of neurodegenerative diseases,including Alzheimer's disease,Huntington's chorea,and Parkinson's disease.This review also describes the potential benefits of treating neurodegenerative diseases by modulating changes in microglial states.Therefore,inducing a shift from the neurotoxic to neuroprotective microglial state in neurodegenerative diseases induced by aging and chronic inflammation holds promise for the treatment of neurodegenerative diseases in the future.

How do neurons age?A focused review on the aging of the microtubular cytoskeleton

Aging is the leading risk factor for Alzheimer’s disease and other neurodegenerative diseases. We now understand that a breakdown in the neuronal cytoskeleton, mainly underpinned by protein modifications leading to the destabilization of microtubules, is central to the pathogenesis of Alzheimer’s disease. This is accompanied by morphological defects across the somatodendritic compartment, axon, and synapse. However, knowledge of what occurs to the microtubule cytoskeleton and morphology of the neuron during physiological aging is comparatively poor. Several recent studies have suggested that there is an age-related increase in the phosphorylation of the key microtubule stabilizing protein tau, a modification, which is known to destabilize the cytoskeleton in Alzheimer’s disease. This indicates that the cytoskeleton and potentially other neuronal structures reliant on the cytoskeleton become functionally compromised during normal physiological aging. The current literature shows age-related reductions in synaptic spine density and shifts in synaptic spine conformation which might explain age-related synaptic functional deficits. However, knowledge of what occurs to the microtubular and actin cytoskeleton, with increasing age is extremely limited. When considering the somatodendritic compartment, a regression in dendrites and loss of dendritic length and volume is reported whilst a reduction in soma volume/size is often seen. However, research into cytoskeletal change is limited to a handful of studies demonstrating reductions in and mislocalizations of microtubule-associated proteins with just one study directly exploring the integrity of the microtubules. In the axon, an increase in axonal diameter and age-related appearance of swellings is reported but like the dendrites, just one study investigates the microtubules directly with others reporting loss or mislocalization of microtubule-associated proteins. Though these are the general trends reported, there are clear disparities between model organisms and brain regions that are worthy of further investigation. Additionally, longitudinal studies of neuronal/cytoskeletal aging should also investigate whether these age-related changes contribute not just to vulnerability to disease but also to the decline in nervous system function and behavioral output that all organisms experience. This will highlight the utility, if any, of cytoskeletal fortification for the promotion of healthy neuronal aging and potential protection against age-related neurodegenerative disease. This review seeks to summarize what is currently known about the physiological aging of the neuron and microtubular cytoskeleton in the hope of uncovering mechanisms underpinning age-related risk to disease.

Single-cell transcriptomic atlas of goat ovarian aging

Background The ovaries are one of the first organs that undergo degenerative changes earlier in the aging process,and ovarian aging is shown by a decrease in the number and quality of oocytes.However,little is known about the molecular mechanisms of female age-related fertility decline in different types of ovarian cells during aging,especially in goats.Therefore,the aim of this study was to reveal the mechanisms driving ovarian aging in goats at single-cell resolution.Results For the first time,we surveyed the single-cell transcriptomic landscape of over 27,000 ovarian cells from newborn,young and aging goats,and identified nine ovarian cell types with distinct gene-expression signatures.Functional enrichment analysis showed that ovarian cell types were involved in their own unique biological processes,such as Wnt beta-catenin signalling was enriched in germ cells,whereas ovarian steroidogenesis was enriched in granulosa cells(GCs).Further analysis showed that ovarian aging was linked to GCs-specific changes in the antioxidant system,oxidative phosphorylation,and apoptosis.Subsequently,we identified a series of dynamic genes,such as AMH,CRABP2,THBS1 and TIMP1,which determined the fate of GCs.Additionally,FOXO1,SOX4,and HIF1A were identified as significant regulons that instructed the differentiation of GCs in a distinct manner during ovarian aging.Conclusions This study revealed a comprehensive aging-associated transcriptomic atlas characterizing the cell typespecific mechanisms during ovarian aging at the single-cell level and offers new diagnostic biomarkers and potential therapeutic targets for age-related goat ovarian diseases.

Hypothalamic circuits and aging:keeping the circadian clock updated

Over the past century,age-related diseases,such as cancer,type-2 diabetes,obesity,and mental illness,have shown a significant increase,negatively impacting overall quality of life.Studies on aged animal models have unveiled a progressive discoordination at multiple regulatory levels,including transcriptional,translational,and post-translational processes,resulting from cellular stress and circadian derangements.The circadian clock emerges as a key regulator,sustaining physiological homeostasis and promoting healthy aging through timely molecular coordination of pivotal cellular processes,such as stem-cell function,cellular stress responses,and inter-tissue communication,which become disrupted during aging.Given the crucial role of hypothalamic circuits in regulating organismal physiology,metabolic control,sleep homeostasis,and circadian rhythms,and their dependence on these processes,strategies aimed at enhancing hypothalamic and circadian function,including pharmacological and non-pharmacological approaches,offer systemic benefits for healthy aging.Intranasal brain-directed drug administration represents a promising avenue for effectively targeting specific brain regions,like the hypothalamus,while reducing side effects associated with systemic drug delivery,thereby presenting new therapeutic possibilities for diverse age-related conditions.

Strengthening Active Aging through Older People’s Association and Economic Activity of the Older People in Nepal

Aging is a natural lifelong process ending in death. Many older people are living in poverty. Older people are generally considered dependent on others as they grow older. The purpose of this article is to explore the entrepreneurship activities of Nepalese older adults. Data for this study were collected from the project Help Age International (HAI) implemented in Nepal. Qualitative data observations and interviews were used to collect data. The findings of this study show the formation of the Older People’s Association (OPA) has supported many older people to participate outside the home in various social activities. Moreover, regular deposits through OPAs offer little help. OPAs support older people in their need of financial support to implement minor entrepreneurship. Older people who received support were pleased and were actively involved in their activities and also regularly deposited money in them. Subsequently, older people’s participation in social activities has increased and also helped to lower elderly abuse, loneliness, and depression. Local governments should promote such activities which will help with healthy aging.

Skeletal phenotypes and molecular mechanisms in aging mice

Aging is an inevitable physiological process,often accompanied by age-related bone loss and subsequent bone-related diseases that pose serious health risks.Research on skeletal diseases caused by aging in humans is challenging due to lengthy study durations,difficulties in sampling,regional variability,and substantial investment.Consequently,mice are preferred for such studies due to their similar motor system structure and function to humans,ease of handling and care,low cost,and short generation time.In this review,we present a comprehensive overview of the characteristics,limitations,applicability,bone phenotypes,and treatment methods in naturally aging mice and prematurely aging mouse models(including SAMP6,POLG mutant,LMNA,SIRT6,ZMPSTE24,TFAM,ERCC1,WERNER,and KL/KL-deficient mice).We also summarize the molecular mechanisms of these aging mouse models,including cellular DNA damage response,senescence-related secretory phenotype,telomere shortening,oxidative stress,bone marrow mesenchymal stem cell(BMSC)abnormalities,and mitochondrial dysfunction.Overall,this review aims to enhance our understanding of the pathogenesis of aging-related bone diseases.

Homocysteinemia and Depression in Community-Dwelling Older Adults: The Cohort Longitudinal Study “InveCeAb” (Brain Aging in Abbiategrasso)

Depression is a major health problem, especially for elderly people. According to the “homocysteine hypothesis of depression”, high homocysteine levels may cause depression of mood via cerebrovascular diseases. Whilst biologically plausible, such hypothesis needs yet confirmation. We aimed at: 1) studying the relationships between homocysteinemia (HCY) and depression in a community-dwelling cohort of people aged 70 to 75 years at baseline;2) investigating plasma levels of HCY and 3) comparing these levels between males and females, in the same population. We exploited the data from four waves (2010, 2012, 2014 and 2018) of the longitudinal study “InveCeAb”, with specific regard towards mood assessment, by Geriatric Depression Scale (GDS) scoring, and diagnosis of clinically relevant or subthreshold depression. HCY plasma levels were measured in the waves 2012, 2014 and 2018. Sample attrition was due mainly to death or overall worsening. No statistically significant differences were found in plasma homocysteine levels in each wave, according to depressive symptoms. No correlations were found between plasma HCY levels in each wave with their corresponding GDS scores, even after adjustment for folate and cobalamin blood concentrations. Dichotomized levels of HCY (≤15 vs >15 μM/l) were not associated with dichotomized GDS scores (≤4 vs higher), clinically relevant and subthreshold depression diagnosis and any antidepressive use, in any wave. First (2012) HCY levels increased with participants’ increasing age, cross-sectionally. Listwise HCY concentrations decreased along the 3 waves. HCY levels were always higher in males than in females. Our results may challenge the “homocysteine hypothesis” of depression, whilst supporting the role of high homocysteinemia as a marker of overall bad health.

Novel Method for Evaluating the Aging of Aviation Turbine Engine Oils via High-Temperature Bearing Deposit Tests

Aviation turbine engine oils require excellent thermal-oxidative stability because of their high-temperature environments.High-temperature bearing deposit testing is a mandatory method for measuring the thermal-oxidative performance of aviation lubricant oils,and the relevant apparatus was improved in the present study.Two different commercial aviation turbine engine oils were tested,one with standard performance(known as the SL oil)and the other with high thermal stability,and their thermal-oxidative stability characteristics were evaluated.After 100 h of high-temperature bearing testing,the SL oil was analyzed by using various analytical techniques to investigate its thermal-oxidative process in the bearing test,with its thermal-oxidative degradation mechanism also being discussed.The results indicate that the developed high-temperature bearing apparatus easily meets the test requirements of method 3410.1 in standard FED-STD-791D.The viscosity and total acid number(TAN)of the SL oil increased with the bearing test time,and various deposits were produced in the bearing test,with the micro-particles of the carbon deposits being sphere-like,rod-like,and sheet-like in appearance.The antioxidant additives in the oil were consumed very rapidly in the first 30 h of the bearing test,with N-phenyl-1-naphthylamine being consumed faster than dioctyldiphenylamine.Overall,the oil thermal-oxidative process involves very complex physical and chemical mechanisms.

Regulation of aging by NELF-A and RNA polymerase Ⅱ elongation

Epigenetic regulation of aging:Aging is defined as the gradual decline of physiological function and cellular integrity,causing o rganismal vulnerability to age-onset diseases and morbidity.Studies in different animal models have led to the identification of twelve aging hallmarks that shared several features:its age-associated manifestation.

Astrocyte syncytium:from neonatal genesis to aging degeneration

Modern neuroscience began from all reaching and fierce conflict between“neuronismo and reticulismo”——between neuronal and reticular theories of the organization of the nervous system;the conflict culminated in December of 1906 in Stockholm where Santiago Ramon y Cajal(the proponent of the neuronal doctrine)and Camillo Golgi(who advocated the syncytial reticular organization of neural networks)delivered their Noble prize lectures(Verkhratsky,2009).

Preventing brain aging by the artificial enforcement of the unfolded protein response:future directions

As the life expectancy of the world’s population increases,age-related diseases are emerging as one of the greatest problems facing modern society.The onset of dementia and neurodegenerative diseases is strictly dependent on aging as a major risk factor and has a profound impact on various aspects of the lives of individuals and their families.

Training muscles to keep the aging brain fit

1.Aging and exercise Aging is associated with the decline of cellular,tissue,and systemic functions and is characterized by at least 7 highly interdependent molecular pillars of aging1(Fig.1).Besides compromised genetic functions(telomer shortening and epigenetic dysregulation),metabolic efficiency(impaired mitochondrial functions and nutrient sensing),and cellular stress responses deteriorate.Consequential disruption of normal protein regulation(proteostasis)in combination with impaired cellular waste clearance leads to the accumulation of macromolecular damage(and in some cases to specific protein aggregation pathologies,like in Alzheimer’s dementia brains).

Dendritic spine degeneration:a primary mechanism in the aging process

Recent reports suggest that aging is not solely a physiological process in living beings;instead, it should be considered a pathological process or disease(Amorim et al., 2022). Consequently, this process involves a wide range of factors, spanning from genetic to environmental factors, and even includes the gut microbiome(GM)(Mayer et al., 2022). All these processes coincide at some point in the inflammatory process, oxidative stress, and apoptosis, at different degrees in various organs and systems that constitute a living organism(Mayer et al., 2022;AguilarHernández et al., 2023).

Regeneration mechanisms and therapeutic strategies for neuromuscular junctions in aging and diseases

The neuromuscular junction(NMJ)is an essential synaptic structure composed of motor neurons,skeletal muscles,and glial cells that orchestrate the critical process of muscle contraction(Li et al.,2018).The typical NMJ structure is classically described as having a“pretzel-like”shape in mice(Figure 1),whereas human NMJs have a smaller,fragmented structure throughout adulthood.Degenerated NMJs exhibit smaller or fragmented endplates,partial denervation,reduced numbers of synaptic vesicles,abnormal presynaptic mitochondria,and dysfunctional perisynaptic Schwann cells(Alhindi et al.,2022).

Associations of accelerometry-measured and self-reported physical activity and sedentary behavior with skeletal muscle energetics:The Study of Muscle,Mobility and Aging(SOMMA)

Background:Skeletal muscle energetics decline with age,and physical activity(PA)has been shown to offset these declines in older adults.Yet,many studies reporting these effects were based on self-reported PA or structured exercise interventions.Therefore,we examined the associations of accelerometry-measured and self-reported PA and sedentary behavior(SB)with skeletal muscle energetics and explored the extent to which PA and sedentary behavior would attenuate the associations of age with muscle energetics.Methods:As part of the Study of Muscle,Mobility and Aging,enrolled older adults(n=879),810(age=76.4±5.0 years old,mean±SD;58%women)had maximal muscle oxidative capacity measured ex vivo via high-resolution re spirometry of permeabilized myofibers(maximal oxidative phosphorylation(maxOXPHOS))and in vivo by ^(31)phosphorus magnetic resonance spectroscopy(maximal adenosine triphosphate(ATP_(max))).Accelerometry-measured sedentary behavior,light activity,and moderate-to-vigorous PA(MVPA)were assessed using a wrist-worn ActiGraph GT9X over 7 days.Self-reported sedentary behavior,MVPA,and all PA were assessed with the Community Healthy Activities Model Program for Seniors(CHAMPS)questionnaire.Linear regression models with progressive covariate adjustments evaluated the associations of sedentary behavior and PA with muscle energetics,as well as the attenuation of the age/muscle energetics association by MVP A and sedentary behavior.As a sensitivity analysis,we also examined activPAL-measured daily step count and time spent in sedentary behavior and their associations with muscle energetics.Results:Every 30 min/day more of ActiGraph-measured MVPA was associated with 0.65 pmol/(s×mg)higher maxOXPHOS and 0.012 mM/s higher ATP_(max)after adjusting for age,site/technician,and sex(p<0.05).Light activity was not associated with maxOXPHOS or ATP_(max).Meanwhile,every 30 min/day spent in ActiGraph-measured sedentary behavior was associated with 0.39 pmol/s×mg lower maxOXPHOS and0.006 mM/s lower ATP_(max)(p<0.05).Only associations with ATP_(max)held after further adjusting for socioeconomic status,body mass index,lifestyle factors,and multimorbidity.CHAMPS MVPA and all PA yielded similar associations with maxOXPHOS and ATP_(max)(p<0.05),but sedentary behavior did not.Higher activPAL step count was associated with higher maxOXHPOS and AT_(Pmax)(p<0.05),but time spent in sedentary behavior was not.Additionally,age was significantly associated with muscle energetics for men only(p<0.05);adjusting for time spent in ActiGraph-measured MVPA attenuated the age association with ATP_(max)by 58%in men.Conclusion:More time spent in accelerometry-measured or self-reported daily PA,especially MVPA,was associated with higher skeletal muscle energetics.Interventions aimed specifically at increasing higher intensity activity might offer potential therapeutic interventions to slow age-related decline in muscle energetics.Our work also emphasizes the importance of taking PA into consideration when evaluating associations related to skeletal muscle energetics.