Aging Process Research Articles

Impacts of chronic diseases and multimorbidity on health-related quality of life among community-dwelling elderly individuals in economically developed China: evidence from cross-sectional survey across three urban centers

ObjectiveAs the ageing process in China further accelerates and the average life expectancy increases, chronic disease prevalence and multimorbidity rates are constantly rising, especially among elderly individuals. However, few previous studies have explored the impacts of chronic diseases and multimorbidity on health-related quality of life (HRQoL). This study aimed to investigate this association among community-dwelling elderly individuals in China.MethodsA cross-sectional study was conducted in communities in three cities (Suzhou, Qingdao, and Guangzhou). The basic characteristics, chronic diseases and HRQoL of participants were collected, and HRQoL was measured by the EuroQol 5-Dimensions 3-Level version (EQ-5D-3L). Logistic regression, Tobit regression and generalized linear models were used to assess the impacts of chronic diseases and multimorbidity on HRQoL.ResultsApproximately 83.2 percent of the 1,218 respondents had chronic conditions, with 30 percent having multimorbidity. After controlling for sociodemographic and health behaviour factors, patients with stroke were more likely to report problems in all five dimensions of the EQ-5D and had a lower EQ-5D utility index (UI) (b = -0.342) than patients with other chronic conditions. Patients with chronic pulmonary obstruction had a lower EuroQol Visual Analog Scale (EQ-VAS) (b = -11.169) than patients with other chronic conditions. Furthermore, patients with multimorbidity had worse HRQoL (P < 0.001).ConclusionsBoth chronic condition probability and multimorbidity rates were high among Chinese community-dwelling elderly individuals. Different disease types had varying degrees of impact on HRQoL, and patients with multimorbidity had worse HRQoL. This study proposes that the government enhance the quality of life of community-dwelling elderly individuals with multimorbidity by establishing long-term care insurance and expanding comprehensive community-based home health care services.

Consumption of a Probiotic Blend with Vitamin D Improves Immunity, Redox, and Inflammatory State, Decreasing the Rate of Aging—A Pilot Study

There is evidence of the effect of probiotic intake on the immune system. However, the effect probiotics may have on the rate of aging is unknown. The aim of this study is to determine the effect of a probiotic blend on immunity, redox state, inflammation, and the rate of aging or biological age. A group of 10 men and 14 women took, daily for 2 months, a sachet with three probiotics (Bifidobacterium animalis subsp. lactis BSO1, Lactobacillus reuteri LRE02, Lactobacillus plantarum LP14) and vitamin D. Before starting the treatment and after 2 months, peripheral blood was collected. Immune functions were assessed in isolated immune cells, and cytokine concentrations were also measured both in mononuclear cell cultures and plasma. Redox state parameters were also analyzed in whole blood cells. Finally, the Immunity Clock was applied to determine the biological age. Results show that the intake of this probiotic blend in general, in both men and women, improves immunity and decreases the oxidative and inflammatory state. In addition, it rejuvenates the biological age by 10 years on average. It can be concluded that this probiotic blend could be proposed as a good strategy to slow down the aging process, and to achieve healthy aging.

An Analysis of the Impact of Population Ageing on Inflation in China

Abstract: The relationship between demographic change and economic development is one of the most recent and important research topics. Researchers have found that aging will have a certain impact on inflation, but there is still a research gap and controversy on China's inflation problem. Therefore, this paper collects data on the aging process of China's population and inflation rate between 2004 and 2023 and applies graphical analysis and literature analysis to study the data to try to find a cleaner relationship. Through the research, it can be concluded that China's changing population structure has a relatively inhibitory effect on inflation and a negative effect on economic development. The reason may be that the decline in the labor force caused by population aging has a greater impact on aggregate demand than on aggregate supply. Overall, to reduce the impact of the deepening process of population aging, postponing the retirement age and developing the elderly care industry can be an effective way to boost aggregate supply growth to control the increased inflation rate.

Neuronal cathepsin S increases neuroinflammation and causes cognitive decline via CX3CL1-CX3CR1 axis and JAK2-STAT3 pathway in aging and Alzheimer's disease.

Aging is an intricate process involving interactions among multiple factors, which is one of the main risks for chronic diseases, including Alzheimer's disease (AD). As a member of cysteine protease, cathepsin S (CTSS) has been implicated in inflammation across various diseases. Here, we investigated the role of neuronal CTSS in aging and AD started by examining CTSS expression in hippocampus neurons of aging mice and identified a significant increase, which was negatively correlated with recognition abilities. Concurrently, we observed an elevation of CTSS concentration in the serum of elderly people. Transcriptome and fluorescence-activated cell sorting (FACS) results revealed that CTSS overexpression in neurons aggravated brain inflammatory milieu with microglia activation to M1 pro-inflammatory phenotype, activation of chemokine C-X3-C-motif ligand 1 (CX3CL1)-chemokine C-X3-C-motif receptor 1 (CX3CR1) axis and janus kinase 2 (JAK2)-signal transducer and activator of transcription 3 (STAT3) pathway. As CX3CL1 is secreted by neurons and acts on the CX3CR1 in microglia, our results revealed for the first time the role of neuron CTSS in neuron-microglia "crosstalk." Besides, we observed elevated CTSS expression in multiple brain regions of AD patients, including the hippocampus. Utilizing CTSS selective inhibitor, LY3000328, rescued AD-related pathological features in APP/PS1 mice. We further noticed that neuronal CTSS overexpression increased cathepsin B (CTSB) activity, but decreased cathepsin L (CTSL) activity in microglia. Overall, we provide evidence that CTSS can be used as an aging biomarker and plays regulatory roles through modulating neuroinflammation and recognition in aging and AD process.

Interaction between roadway and sewer/water pipes

Sewage pipes and drinking water pipes as well as all other pipes such as gas, district heating, electricity, internet, telephone, cable TV, etc. in densely populated areas are located in the road space. Over time, the traffic loads as well as the road structure can change. In addition, the materials of the pipelines are subject to ageing processes. The consequences of leaking drinking water and wastewater pipes that lie in the body of the road can have extremely negative effects. Firstly, the wastewater contains harmful substances that must not be allowed to enter the groundwater under any circumstances. Secondly, the leaking drinking water pipes, especially a water pipe burst, cause the soil mechanical changes in the subsoil and the traffic surface pavements and can cause immense damage in the road surface or in the road body itself.

Development of a Spectral Flow Cytometry Analysis Pipeline for High-dimensional Immune Cell Characterization.

Flow cytometry is used for immune cell analysis for cell composition and function. Spectral flow cytometry allows for high-dimensional analysis of immune cells, overcoming limitations of conventional flow cytometry. However, analyzing data from large Ab panels is challenging using traditional biaxial gating strategies. We present, to our knowledge, a novel analysis pipeline to improve analysis of spectral flow cytometry. We employ this method to identify rare T cell populations in aging. We isolated splenocytes from young (2-3 mo old) and aged (18-19 mo old) female C57BL/6N mice and then stained these with a panel of 20 fluorescently labeled Abs. We performed spectral flow cytometry and then data processing and analysis using Python within a Jupyter Notebook environment to perform dimensionality reduction, batch correction, unsupervised clustering, and differential expression analysis. Our analysis of 3,776,804 T cells from 11 spleens revealed 35 distinct T cell clusters identified by surface marker expression. We observed significant differences between young and aged mice, with clusters enriched in one age group over the other. Naive, effector memory, and central memory CD8+ and CD4+ T cell subsets exhibited age-associated changes in abundance and marker expression. We also demonstrate the utility of our pipeline in a human PBMC dataset that used a 50-fluorescent color panel. By leveraging high-dimensional analysis methods, we provide insights into the immune aging process. This approach offers a robust and easily implemented analysis pipeline for spectral flow cytometry data that may facilitate the discovery of novel therapeutic targets for age-related immune dysfunction.

Transparent Coating Systems Applied on Spruce Wood and Their Colour Stability on Exposure to an Accelerated Ageing Process

The objective of this study was to investigate the colour stability of spruce wood surfaces treated with coating systems (CS) and exposed to accelerated ageing. The tested CSs were transparent and three-layered; the top layer was modified with ultraviolet (UV) absorbers, while the base layer was modified with lignin stabiliser. Spruce wood surfaces treated with unmodified CSs were not colour-stable during the accelerated ageing process, with the surface exhibiting colour change after just 100 ageing hours. Adding specific UV absorbers into the top layer and lignin stabiliser into the base layer significantly improved the colour stability of the surface-treated wood. In all cases, however, the colour variation associated with ongoing ageing was significant. An additional study task was to determine whether the discolouration of surface-treated wood is caused by the discolouration of the wood substrate alone or also by the CS discolouration. Consequently, there was also the examination of discolouration of the individual coating materials or coating systems applied to glass slides. This testing proved that in the case of wood surface-treated with CS, without lignin stabiliser, the discolouration was the same as that of the substrate, and this was true throughout the whole ageing process. In the case of wood surface-treated with CS, but with lignin stabiliser, there were, in some cases, significant differences in discolouration between surface-treated wood and the wood substrate. These variations were especially evident during the initial 300 ageing hours.

The Healing Environment Approach in Elderly-Friendly Resort Design Based on Nvivo Analysis

The aging process in the elderly results in physical, psychological, and social declines that can lead to various health issues. Many elderly individuals engage in travel activities, such as visiting new places or spending time abroad, as a means of psychological satisfaction and self-actualization, improving their overall quality of life. However, a significant concern is whether resort areas provide adequate comfort and safety for elderly tourists, as many destinations are not elderly-friendly. This research aims to explore the concept of healing, the specific needs of the elderly in tourism for comfort and security, and how to design an ideal resort for the elderly. This research employs a mixed-methods approach, using both quantitative and qualitative data. Quantitative data were processed using SPSS/SmartPLS, while qualitative data were analyzed using NVivo. The research's findings highlight the importance of a "healing environment" in resort design for the elderly, with considerations for accessibility, psychological well-being, and integration with nature. The results provide insights into how a resort can be designed to meet the physical and emotional needs of elderly tourists. The research's implications suggest that applying the "healing environment" approach can significantly enhance the safety, comfort, and overall experience for elderly visitors in tourism settings.

Biologically informed machine learning modeling of immune cells to reveal physiological and pathological aging process

The immune system undergoes progressive functional remodeling from neonatal stages to old age. Therefore, understanding how aging shapes immune cell function is vital for precise treatment of patients at different life stages. Here, we constructed the first transcriptomic atlas of immune cells encompassing human lifespan, ranging from newborns to supercentenarians, and comprehensively examined gene expression signatures involving cell signaling, metabolism, differentiation, and functions in all cell types to investigate immune aging changes. By comparing immune cell composition among different age groups, HLA highly expressing NK cells and CD83 positive B cells were identified with high percentages exclusively in the teenager (Tg) group, whereas unknown_T cells were exclusively enriched in the supercentenarian (Sc) group. Notably, we found that the biological age (BA) of pediatric COVID-19 patients with multisystem inflammatory syndrome accelerated aging according to their chronological age (CA). Besides, we proved that inflammatory shift- myeloid abundance and signature correlate with the progression of complications in Kawasaki disease (KD). The shift- myeloid signature was also found to be associated with KD treatment resistance, and effective therapies improve treatment outcomes by reducing this signaling. Finally, based on those age-related immune cell compositions, we developed a novel BA prediction model PHARE (https://xiazlab.org/phare/), which can apply to both scRNA-seq and bulk RNA-seq data. Using this model, we found patients with coronary artery disease (CAD) also exhibit accelerated aging compared to healthy individuals. Overall, our study revealed changes in immune cell proportions and function associated with aging, both in health and disease, and provided a novel tool for successfully capturing features that accelerate or delay aging.

Research of Optical Properties and Biocompatibility in Different Zones of Multilayered Translucent Zirconia on Hydrothermal Aging

Objective: We assessed the changes in optical properties and biocompatibility of transition zones in multilayered translucent monolithic zirconia exposed to prolonged hydrothermal aging and compared the results to those with different yttrium oxide contents. Materials and Methods: Four types of zirconia blocks from IPS e.max ZirCAD were used: 3Y-TZP e.max ZirCAD LT (ZL), 4Y-TZP e.max ZirCAD MT (ZM), 5Y-TZP e.max ZirCAD MT Multi (ZT), and 3Y/5Y-TZP e.max ZirCAD Prime (ZP). A total of 120 specimens (15.0 mm diameter and 1.5 mm height) were fabricated and divided into three groups (n = 10). The aging process for the specimens was conducted in an autoclave set to 134 °C and 0.2 MPa, with durations of 0 h (control), 5 h (first aged), and 10 h (second aged). The optical properties and biocompatibility were analyzed, followed by a statistical analysis of the data (α = 0.05). Results: Before and after aging, ZL and ZP exhibited the lowest color changes. ZT exhibited the highest average transmittance and translucency parameter values, while ZL had the lowest. The water contact angle test showed the highest value in ZM and lowest in ZL across all the aging stages. ZL, ZM, and ZP showed a considerable decrease in the water contact angle; however, ZT did not. A cell counting kit-8 assay showed ZL had the highest value, while ZM had the lowest. A filamentous actin test exhibited the highest value in ZL and lowest in ZM. In the vinculin analysis, ZL and ZT exhibited the lowest values, whereas ZM and ZP had the highest. Conclusion: 3Y/5Y-TZP exhibited a balanced performance across critical parameters, such as color stability, translucency, and biocompatibility, aligning with 3Y-TZP. While 5Y-TZP demonstrated superior translucency, it confirmed the lowest color stability, whereas 3Y-TZP achieved the highest biocompatibility. These properties provide clinicians with a reliable material option that ensures superior esthetic outcomes and long-term prognosis, ultimately contributing to improved patient satisfaction and clinical longevity.

Late-onset caloric restriction improves cognitive performance and restores circadian patterns of neurotrophic, clock and epigenetic factors in the hippocampus of male old rats.

Aging is a complex multifactorial process that results in a general functional decline, including cognitive impairment. Caloric restriction (CR) can positively influence the aging processes and delay cognitive decline. There is a rhythmic variation in memory and learning processes throughout the day, indicating the involvement of the circadian clock in the regulation of these processes. Despite growing evidence on the efficacy of CR, it has not yet been fully determined whether starting this strategy at an advanced age is beneficial for improving quality of life and eventually, for protection against age-related diseases. Here, we investigated the effect of late-onset CR on the temporal organization of the molecular clock machinery, molecules related to cognitive processes and epigenetic regulation, in the hippocampus of male old rats maintained under constant darkness conditions. Our results evidenced the existence of a highly coordinated temporal organization of Bmal1, Clock, Bdnf, Trkb, Dnmts, Sirt1, and Pgc-1α in the hippocampus of young adult rats. We observed that aging led to cognitive deficits and loss of circadian oscillations of all the above variables. Interestingly, CR restored circadian rhythmicity in all cases and, in addition, improved the cognitive performance of the old animals. This work would highlight the importance of the circadian clock and its synchronization with feeding signals, as the basis of the beneficial effects of CR. Thus, lifestyle modifications, such as CR, might be a powerful intervention to preserve hippocampal circadian organization and cognitive health during aging.

Stachys byzantina K. Koch (Lamiaceae) as a potential ingredient for delaying skin ageing and treating hyperpigmentation disorders in pharmaceutical products.

This study aimed to investigate whether the plant species Stachys byzantina produces bioactives with the potential to delay the skin ageing process and treat hyperpigmentation conditions. The antioxidant action was assessed by 2,2-diphenyl-1-picrylhydrazylradical scavenging, Griess reaction, oxygen radical absorption capacity, and β-carotene bleaching assays. Inhibitory activities for tyrosinase, hyaluronidase, and elastase enzymes were tested. The antiglycation activity, the sun protection factor (SPF), and the toxicity to skin cells by MTT(3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide)assay were also evaluated. The ethanolic extract of S. byzantina aerial parts and all fractions obtained by solvent partition inhibited the tyrosinase enzyme at different levels. The dichloromethane fraction (DF) demonstrated the highest inhibition (IC50 = 63.5±10.9 µg/ml). DF also inhibited the hyaluronidase enzyme with IC50 = 369±11.64 μg/ml and elastase by 40% at 500 μg/ml. This fraction showed prominent antioxidant and antiglycation activities, high SPF, and no cytotoxicity at concentrations lower than 50 μg/ml. The phenolic and flavonoid contents were 116.30±6.7 (mgTAE/g) and 66.38±13.5 (mgQE/g), respectively. Chlorogenic acid (23.54±2.46mg/g) and verbascoside (203.97±19.8mg/g) were identified and quantified. Stachys byzantina is a potential source of cosmetic and therapeutic ingredients to reduce hyperpigmentation and the impacts caused by free radicals, advanced glycation end products, and sun radiation in skin ageing.

An evaluation of trends for mesothelioma mortality in American women: Addressing the content of a recent Morbidity and Mortality Weekly Report (MMWR).

Mesothelioma is a fatal disease that has historically been associated with exposure to airborne asbestos. Because occupational asbestos exposures dropped dramatically in the late 1960s and early 1970s, far fewer cases of mesothelioma today are due to these fibers but, instead, are usually a result of the aging process or genetic predisposition. In May of 2022, a Morbidity and Mortality Weekly Report (MMWR) was issued by the Centers for Disease Control and Prevention (CDC) regarding malignant mesothelioma incidence in women from 1999 to 2020. While this MMWR alerted citizens to the continued presence of the disease, after reading this article one might have thought that the CDC was suggesting that the disease was increasing in women due to asbestos exposures (which it is not). In the present analysis, we investigate several factors related to the interpretation of epidemiological data for mesothelioma, including the role of asbestos as a risk factor over time. The authors conducted a review of the scientific community's understanding of mesothelioma incidence and asbestos exposures amongst women, as well as an investigation of the methods and references in the MMWR article. Although various articles have recently discussed the incidence of both peritoneal and pleural mesothelioma in women, it is fortunate that the age-adjusted rates for mesothelioma have remained flat (neither increased nor decreased significantly) in women for the past 50 years. Incredibly few women in the U. S. have had appreciable cumulative exposures to any type of asbestos (chrysotile, amosite, or crocidolite) in the workplace or from the ambient environment, especially since about 1965-1970. In this paper, we highlight six factors that should be considered when evaluating the incidence of mesothelioma amongst American women in the current era. Without sufficient consideration of these factors, improper conclusions have been drawn over the past several years.

Microstructure evolution and mechanical behavior of 2024 aluminum alloy under electric pulse treatment

This study examined the effects of electric pulse treatment (EPT) on solution-treated 2024 alloy. We found that the combined effect of non-uniform stress field caused by thermal expansion and localized Joule heating promoted the formation of helical dislocations. During the subsequent aging process, these severely deformed helical dislocations formed a network configuration, which accelerated the coarsening of the S phase, and the S phase also retained a helical shape. Compared to conventional solution-treated samples, the yield strength of the EPT samples increased by 24 % with almost no loss of fracture elongation. The increase in strength is primarily due to the increase of volume fraction of rod-shaped S phase，enhancing the matrix's resistance to deformation. This study proposes a simple and rapid method to adjust dislocation configurations and aging precipitation through electric pulses, offering new insights for the industrial application of aluminum alloys to swiftly enhance mechanical properties.

The role of high mobility group proteins in cellular senescence mechanisms

Aging is a universal physiological phenomenon, and chronic age-related diseases have become one of the leading causes of human mortality, accounting for nearly half of all deaths. Studies have shown that reducing the incidence of these diseases can not only extend lifespan but also promote healthy aging. In recent years, the potential role of non-histone high-mobility group proteins (HMGs) in the regulation of aging and lifespan has attracted widespread attention. HMGs play critical roles in cellular senescence and associated diseases through various pathways, encompassing multi-layered mechanisms involving protein interactions, molecular regulation, and chromatin dynamics. This review provides a comprehensive analysis of the interactions between HMG family proteins and senescence-associated secretory phenotype (SASP), chromatin structure, and histone modifications, offering a deeper exploration of the pivotal functions and impacts of HMGs in the aging process. Furthermore, we summarize recent findings on the contributions of HMG proteins to aging and age-related diseases. HMG proteins not only regulate senescence-associated inflammation through modulating the SASP but also influence genomic stability and cell fate decisions via interactions with chromatin and histones. Targeting HMG proteins holds great potential in delaying the progression of aging and its associated diseases. This review aims to provide a systematic overview of HMG proteins’ roles in aging and to lay a solid foundation for future anti-aging drug development and therapeutic strategies. With the advancing understanding of the mechanisms by which HMGs regulate aging, developing therapeutic interventions targeting HMGs may emerge as a promising approach to extending lifespan and enhancing healthspan.

Internet use and cognitin among American middle-aged and older adults: The gendered moderating effect of age

The popularity of Internet use brings more potential for healthy cognitive aging among older adults. Emerging studies have examined the age and gender differences in the link between older adults&amp;rsquo; Internet use and cognition. However, few studies have investigated the gendered age difference regarding this association. The purpose of this study was to examine whether age would moderate the effect of Internet use on cognition among middle-aged and older adults and whether this relationship would be different between men and women. A total of 6,338 adults aged 50 or older were drawn on from the 2016 Wave of the Health and Retirement Study. Sequential linear regressions were conducted to examine the interactions between Internet use, age, and gender on cognition. The three-way interaction of Internet use, age, and gender was a significant predictor of cognition (&amp;beta; = 0.01, p &lt; 0.05). Specifically, the positive effect of Internet use on cognition was higher among older women of older age than those of younger age, while the positive effect remained the same for older men of different ages. The Internet offers a valuable resource for engaging middle-aged and older adults in activities that not only provide social interaction but also stimulate cognitive processes. The study suggests that the aging process does not necessarily inhibit the cognitive benefits that middle-aged and older adults can gain from using the Internet. Findings from this study indicated that future Internet/technology training to increase cognition among middle-aged and older adults should be age- and gender-tailored.

Phenomenological study: Spiritual life of older adults

Purpose: As getting older, individuals may face various physical, mental, and social challenges that are a natural part of life. In recent times, an increasing number of individuals have been exploring the potential benefits of spirituality in enhancing the overall quality of life and well-being for older adults. Spirituality can take on many forms, including religious beliefs, the pursuit of purpose and significance, and the comprehension of faith, among other areas. This research aims to thoroughly examine and uncover the spiritual practices and beliefs of older adults residing in East Java, Indonesia. Method: This study involved qualitative research using a phenomenological methodology to gather data from ten older adults (60-90 years old) living at home in Malang Raya, Jawa Timur Provinces, Indonesia. Data was gathered through in-depth interviews and observations which were analyzed using Colaizzi's phenomenological methodology. A total of 10 questions were asked in the interviews. Result: After conducting research, it was discovered that the spiritual experiences of older adult Indonesians could be categorized into eight distinct areas, which could be further grouped into two major themes and three minor themes. The two major themes were the recognition of an invisible power during the aging process and the importance of building a strong connection with God. Conclusion: The spiritual life of senior citizens is a significant source of strength and fortitude, providing them with the necessary resilience to face the physical and mental challenges that come with transcendence. It is essential to recognize the transformative nature of a strong spiritual foundation, which can uplift and empower older adults to overcome the difficulties that may arise in the later stages of life.

The environmental impact on aging: Insights from buccal mucosa and molecular biomarkers

Buccal epithelial cells serve as a primary barrier against the inhalation and ingestion of harmful substances, working alongside immune system cells such as natural killer cells to protect the body from health-damaging factors. These epithelial cells can also be used as an alternative tissue source for monitoring the genotoxic effects of external factors such as chemical exposure. This assessment can be performed using molecular biomarkers of aging, which reflect biological age and indicate cellular aging acceleration due to internal and external damage factors, such as environmental hazards. In contrast to chronological age, which merely reflects the passage of time, biological age accounts for individual variation in aging processes. Molecular biomarkers are crucial for distinguishing between normal and pathological processes in the body and for identifying the effects of external factors such as chemical exposures. The identification of specific biomarkers enhances the ability to detect and monitor adverse biological responses and accelerated aging. This review aims to highlight the routes through which environmental hazards enter the body, the application of buccal epithelial cells in assessing genetic modifications, and the introduction of potential molecular biomarkers. However, further research is necessary to elucidate the roles of these biomarkers in determining aging rates and individual variability. Understanding their implications may also help identify new therapeutic targets for preventing premature aging, treating age-related diseases, and developing potential treatments.

Multi-stage precipitation modeling for AA 7050 hole repairs in additive friction stir deposition

A multi-stage precipitation model is formulated to predict the microstructural evolution and explain the high performance of additive friction stir deposited aluminum alloy 7050 (AA 7050) for hole repair. The first stage is the heating process due to the high-temperature thermomechanical process of the stir. In this process, small η precipitates dissolve as they lose their stability with increasing temperature, and this causes the volume fraction of η precipitates to decrease and the concentration of Mg and Zn in the matrix to increase. The second stage is the cooling process at the end of the repair where material feeding ends and the tool is lifted away. Heterogeneous nucleation of η precipitates may occur and as the temperature cools below 250 °C, Guinier–Preston (GP) zones start to form. The final stage is the natural aging process, where the η′ precipitate starts to grow. The volume fraction and precipitate radius are predicted for each type of precipitate. Furthermore, the fine η′ precipitates and GP zones with a decent volume fraction improve the material strength and fatigue life.

Breadth and polyfunctionality of T cell responses to human cytomegalovirus in men who have sex with men: relationship with HIV infection and frailty.

T cell responses to chronic cytomegalovirus (CMV) infection have significant biological and clinical implications in HIV infection and aging. Here, we systematically analyzed the breadth, magnitude, and polyfunctionality of T cell responses to multiple CMV antigens in men with and without HIV in the Multicenter AIDS Cohort Study (MACS), a longstanding study of the natural and treated history of HIV-1 infection in men who have sex with men. We found that the breadth and polyfunctionality of T cell responses to CMV were different between men with chronic, treated HIV and those without HIV. The reason for these differences is unknown, but these findings suggest that people with treated HIV may have more frequent CMV reactivation than people without HIV. Differences between people with and without HIV also resembled differences reported between young and older adults without HIV, supporting a role for the immune responses to CMV in the aging process.