natural aging

自然老化
  • 文章类型: Journal Article
    简介:与老年人相关的脑损伤和肠道微生物组破坏很常见。研究证实,调节微生物群-肠-脑轴可以帮助减少与年龄相关的脑损伤。方法:人参,受人尊敬的中医,以其抗衰老能力而闻名。然而,以前的人参抗衰老研究主要集中在患病的动物模型上。为此,因此,我们努力探索补充人参的老年小鼠粪便微生物群移植(FMT)对抗生素预处理的小鼠的潜在神经保护作用。结果:结果,在自然衰老小鼠中进行特定修饰的FMT改善了动物体重增加,延长端粒长度,脑组织抗氧化应激,调节细胞因子的血清水平,平衡Treg细胞的比例.此外,FMT增加了虎尾草科有益菌的丰度,Dubosiella,拟杆菌,等。并降低了自然衰老小鼠粪便样本中潜在致病菌螺杆菌和幼虫的水平。这表明FMT显著地重塑了肠道微生物组。此外,FMT处理的老年小鼠显示熊果酸代谢物水平升高,β-胡萝卜素,S-腺苷甲硫氨酸,亚精胺,鸟苷,塞来昔布,亚油酸,等。,与上述关键有益菌呈显著正相关。此外,这些确定的关键微生物群和代谢产物主要富集在氨基酸代谢途径中,脂质代谢,核苷酸代谢,等。此外,FMT下调p53/p21/Rb信号并上调p16/p14、ATM/突触素I/突触素/PSD95、CREB/ERK/AKT信号在自然衰老后脑损伤中的作用。讨论:总的来说,这项研究表明,FMT对肠道微生物群的重编程阻碍了自然衰老过程中的脑损伤,可能是通过调节微生物群-肠-脑轴。
    Introduction: Aged-related brain damage and gut microbiome disruption are common. Research affirms that modulating the microbiota-gut-brain axis can help reduce age-related brain damage. Methods: Ginseng, esteemed in traditional Chinese medicine, is recognized for its anti-aging capabilities. However, previous Ginseng anti-aging studies have largely focused on diseased animal models. To this end, efforts were hereby made to explore the potential neuroprotective effects of fecal microbiota transplantation (FMT) from Ginseng-supplemented aged mice to those pre-treated with antibiotics. Results: As a result, FMT with specific modifications in natural aging mice improved animal weight gain, extended the telomere length, anti-oxidative stress in brain tissue, regulated the serum levels of cytokine, and balanced the proportion of Treg cells. Besides, FMT increased the abundance of beneficial bacteria of Lachnospiraceae, Dubosiella, Bacteroides, etc. and decreased the levels of potential pathogenic bacteria of Helicobacter and Lachnoclostridium in the fecal samples of natural aged mice. This revealed that FMT remarkably reshaped gut microbiome. Additionally, FMT-treated aged mice showed increased levels of metabolites of Ursolic acid, β-carotene, S-Adenosylmethionine, Spermidine, Guanosine, Celecoxib, Linoleic acid, etc., which were significantly positively correlated with critical beneficial bacteria above. Additionally, these identified critical microbiota and metabolites were mainly enriched in the pathways of Amino acid metabolism, Lipid metabolism, Nucleotide metabolism, etc. Furthermore, FMT downregulated p53/p21/Rb signaling and upregulated p16/p14, ATM/synapsin I/synaptophysin/PSD95, CREB/ERK/AKT signaling in brain damage following natural aging. Discussion: Overall, the study demonstrates that reprogramming of gut microbiota by FMT impedes brain damage in the natural aging process, possibly through the regulation of microbiota-gut-brain axis.
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  • 文章类型: Journal Article
    虽然广泛的研究集中在了解聚乙酸乙烯酯(PVAC)涂料在不同环境条件下的降解机理,对PVAC基白胶的长期稳定性关注有限,尤其是在艺术品中使用时。这项研究调查了加速降解,在模拟光老化下,以及对商业PVAC基白胶的等温处理,这些白胶被认为是当代艺术品中使用的此类材料的代表,以预测其耐久性并评估其在艺术品中的行为。通过加速老化实验,并与艺术品中观察到的自然老化进行比较,该研究揭示了发色团的形成和增塑剂的释放是关键过程;特别是,逐渐变暗被认为是退化过程的早期指标,在FTIR或NMR光谱检测到结构变化之前。增塑剂损失引起玻璃化转变温度的增加,从7°C到高于室温的温度,影响粘合剂的内聚强度,并有助于艺术品中材料的分离。研究结果强调了预防性保护措施的重要性,以减轻基于PVAC的艺术品中的退化问题。
    While extensive research has focused on understanding the degradation mechanisms of Poly(vinyl acetate) (PVAC) paint under different environmental conditions, limited attention has been paid to the long-term stability of PVAC-based white glues, especially when used in artworks. This study investigates the accelerated degradation, under simulated photoaging, and isothermal treatment of a commercial PVAC-based white glue considered representative of this class of materials used in contemporary artworks to predict its durability and assess its behavior in art objects. Through accelerated aging experiments and comparison with natural aging observed in artworks, the study reveals the formation of chromophores and the release of plasticizers as key processes; in particular, the progressive darkening was considered an early indicator of degradation processes, before structural changes could be detected by FTIR or NMR spectroscopies. The plasticizer loss induces an increase in glass transition temperature, from 7 °C to temperatures higher than room temperature, affecting the adhesive\'s cohesive strength and contributing to the detachment of materials in artworks. The findings underscore the importance of preventive conservation measures to mitigate degradation issues in PVAC-based artworks.
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  • 文章类型: Journal Article
    雪茄生产和烟草之间的显著区别在于必要的老化过程,复杂的微生物生长,代谢活动,酶催化,和化学反应相互作用。尽管它在决定雪茄的最终质量方面起着至关重要的作用,我们对这个过程中潜在的化学和生物机制的理解仍然不足。生物质和生物碱是影响雪茄风味的主要成分。因此,研究整个衰老过程可以从探索微生物和酶参与其生物降解开始。在这项研究中,手工制作的雪茄在不同的条件下老化。宏基因组测序用于鉴定负责降解源自烟草叶的生物质和生物碱的微生物和酶。结果表明,各种环境因素,包括温度,湿度,湿度持续时间,和转向频率,在雪茄中产生不同含量的总糖和生物碱。观察到微生物群落和淀粉之间存在显著的相关性,减少糖,总糖,和生物碱。涉及生物质成分分解的关键物种,如淀粉(短小芽孢杆菌,假单胞菌。286,和曲霉裂解状态),还原糖和总糖(曲霉属和荷兰硝基),已确定。此外,被发现有可能导致生物碱化合物的降解,特别是降烟碱和新烟碱。我们的工作有助于更深入地了解微生物在雪茄老化中的作用。此外,特定微生物菌株或发酵剂培养物的选择可用于控制和操纵老化过程,从而进一步改善雪茄产品的风味发展。
    A significant distinction between cigar production and tobacco lies in the necessary aging process, where intricate microbial growth, metabolic activities, enzymatic catalysis, and chemical reactions interact. Despite its crucial role in determining the final quality of cigars, our comprehension of the underlying chemical and biological mechanisms within this process remains insufficient. Biomass and alkaloids are the primary constituents that influence the flavor of cigars. Consequently, investigating the entire aging process could begin by exploring the involvement of microbes and enzymes in their biodegradation. In this study, handmade cigars were aged under different conditions. Metagenomic sequencing was employed to identify the microbes and enzymes responsible for the degradation of biomass and alkaloids derived from tobacco leaves. The results revealed that various environmental factors, including temperature, humidity, duration time, and turning frequency, yielded varying contents of total sugar and alkaloids in the cigars. Significant correlations were observed between microbial communities and starch, reducing sugars, total sugars, and alkaloids. Key species involved in the breakdown of biomass constituents, such as starch (Bacillus pumilus, Pseudomonas sp. 286, and Aspergillus cristatus), reducing sugars and total sugars (Aspergillus cristatus and Nitrolancea hollandica), were identified. Furthermore, Corynespora cassiicola and Pseudomonas fulva were found to potentially contribute to the degradation of alkaloid compounds, specifically nornicotine and neonicotinoid. Our work contributes to a deeper understanding of the microbial roles in the aging of cigars. Moreover, the selection of specific microbial strains or starter cultures can be employed to control and manipulate the aging process, thereby further refining the flavor development in cigar products.
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  • 文章类型: Journal Article
    本文综述了细胞衰老与辐射暴露之间的关系。鉴于专业和医疗领域的人们遇到的电离辐射源范围广泛,以及自然背景辐射的影响,辐射对生物过程的影响,特别是在老化过程中,仍然高度相关。自然和辐射诱导的细胞衰老之间的平行关系揭示了这些过程的共同方面。根据最近的科学数据,电离辐射对衰老相关细胞过程影响的关键点,比如基因组不稳定,线粒体功能障碍,miRNA表达改变,表观遗传概况,和衰老相关分泌表型(SASP)的表现,正在讨论。解开细胞衰老的分子机制可以为在环境暴露的背景下理解年龄相关疾病的分子遗传基础做出有价值的贡献。
    This review discusses the relationship between cellular senescence and radiation exposure. Given the wide range of ionizing radiation sources encountered by people in professional and medical spheres, as well as the influence of natural background radiation, the question of the effect of radiation on biological processes, particularly on aging processes, remains highly relevant. The parallel relationship between natural and radiation-induced cellular senescence reveals the common aspects underlying these processes. Based on recent scientific data, the key points of the effects of ionizing radiation on cellular processes associated with aging, such as genome instability, mitochondrial dysfunction, altered expression of miRNAs, epigenetic profile, and manifestation of the senescence-associated secretory phenotype (SASP), are discussed. Unraveling the molecular mechanisms of cellular senescence can make a valuable contribution to the understanding of the molecular genetic basis of age-associated diseases in the context of environmental exposure.
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  • 文章类型: Journal Article
    在这项研究中,研究了T351回火后短期自然再时效对AA2024铝合金显微组织演变和力学行为的影响。晶粒生长发生在自然再老化样品的微观结构中,大量的Al7Cu2Fe颗粒位于α晶粒内部。在1440分钟的再老化时间,由于θ\'\'的形成,XRD的峰向右强烈移动,S″,θ\',和S\'。结果表明,AA2024合金在自然时效过程中的析出率很高。随着再老化时间的增加,纹理参数几乎保持不变。硬度在最初的60分钟内缓慢增加,然后在60到2880分钟之间迅速增强,最终在2880至11520分钟之间稳定在139HV左右。当自然再老化时间从240分钟增加到2880分钟时,加强趋势加快,即,屈服强度从226.6兆帕增加到357.3兆帕,极限抗拉强度从452.2提高到535.5MPa。与收到的样品(T351回火)相比,再老化片材的极限拉伸强度从455.5MPa提高到535.5MPa,延展性保持不变,硬度从128.8HV增加到138.2HV,这是由于在自然再时效样品中的α-铝晶粒内部存在高含量的Al7Cu2Fe颗粒引起的沉淀加速。研究发现,AA2024合金的Portevin-LeChatelier不稳定性在自然再时效后被有效地推迟。随着自然再老化时间的增加,AA2024板材的应变硬化率增加。1440和2880分钟的自然再时效样品的强化是由于形成θ\'\'而产生的沉淀硬化的协同作用的结果,S″,θ\',和S'阶段,消除PortevinLe-Chatelier的不稳定性,从α-铝到Al7Cu2Fe的高效负载转移。最后,使用由1440或2880分钟自然再时效生产的A2024合金,提出了两种方法。
    In this research, the influence of short-term natural re-aging after T351 temper on the microstructural evolution and mechanical behavior of AA2024 aluminum alloy was investigated. Grain growth occurred in the microstructures of the natural re-aged sample and a large number of Al7Cu2Fe particles were located inside the alpha grains. At the re-aging time of 1440 min, the peaks of XRD were shifted strongly to the right due to the formation of θ\'\', S″, θ\', and S\'. The results revealed that the precipitation rate was high in the AA2024 alloy during natural aging. With increasing the re-aging time, texture parameters remained almost unchanged. The hardness increased slowly within the first 60 min, then enhanced rapidly between 60 and 2880 min, and finally became stable at around 139 HV between 2880 and 11520 min. When the natural re-aging time increased from 240 to 2880 min, the strengthening trended speed up, viz, the yield strength increased from 226.6 to 357.3 MPa, and the ultimate tensile strength enhanced from 452.2 to 535.5 MPa. Compared to the as-received sample (T351 temper), the ultimate tensile strength of the re-aged sheet improved from 455.5 to 535.5 MPa, the ductility remained unchanged, and the hardness increased from 128.8 to 138.2 HV, which was owing to the acceleration of the precipitation caused by the presence of high-content Al7Cu2Fe particles in the interior of the alpha-aluminum grains in the natural re-aged sample. It was found that the Portevin-Le Chatelier instability of AA2024 alloy was effectively postponed after natural re-aging. With increasing the natural re-aging time, the strain hardening rate of the AA2024 sheet increased. The strengthening of the natural re-aged sample for 1440 and 2880 min was a result of a synergistic effect of precipitation hardening due to the formation of θ\'\', S″, θ\', and S\' phases, elimination of Portevin Le-Chatelier instability, and highly efficient load transfer from alpha-aluminum to Al7Cu2Fe. Finally, to use the A2024 alloy produced by natural re-aging for 1440 or 2880 min, two methods were proposed.
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  • 文章类型: Journal Article
    在本研究中,利用拉伸试验研究了固溶处理过程中不同的加热和冷却速率对AA7050合金线材组织和性能的影响,金相显微镜,电子背散射衍射,和透射电子显微镜。发现合金的再结晶晶粒尺寸,经受快速加热的方法,与缓慢加热的方法相比,表现出更小,更均匀的分布。人工时效处理后的低密度η'强化相采用空气冷却法形成。同时,通过使用水淬方法,提供了足够的溶质原子和更多的成核位点,从而形成了大量的η\'强化相。此外,对于T6和T73状态,使用水淬火方法处理的合金显示出比使用空气冷却方法处理的合金更高的强度。此外,在基质中形成了粗糙的沉淀物,观察到了较少的团簇,而使用水淬方法时,不会形成高密度的纳米级团簇和连续沉淀。
    In the present study, the effects of varying heating and cooling rates during the solution treatment process on the microstructure and properties of AA7050 alloy wires were investigated using tensile tests, metallographic microscopy, electron backscattered diffraction, and transmission electron microscopy. It was found that the recrystallized grain size of the alloy, subjected to method of rapid heating, exhibited a smaller and more uniform distribution in comparison to method of slow heating. The low density of η\' strengthening phases after the artificial aging treatment was formed using air cooling method. Meanwhile, by using the water quenching method sufficient solute atoms and more nucleation sites were provided resulting in a large number of η\' strengthening phases being formed. In addition, the alloy processed using the water quenching method displayed higher strength than that treated using the air cooling method for the T6 and T73 states. Furthermore, coarse precipitates formed and less clusters were observed in the matrix, while high density nanoscale clusters and no continuous precipitation are formed when using the water quenching method.
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  • 文章类型: Journal Article
    纳米晶(NC)结构可导致金属和合金的显著强化。获得合适的综合力学性能始终是金属材料的目标。这里,纳米结构的Al-Zn-Mg-Cu-Zr-Sc合金成功地通过高压扭转(HPT)和自然时效处理。分析了自然时效HPT合金的显微组织和力学性能。结果表明,自然时效的HPT合金主要由纳米级晶粒(~98.8nm)组成,纳米尺寸的沉淀物(尺寸为20-28nm),和位错(1.16×1015m-2),并表现出851±6MPa的高拉伸强度和6.8±0.2%的适当伸长率。此外,根据晶粒细化强化评估了被激活并有助于合金屈服强度的多种强化模式,降水加强,和位错强化,结果表明,晶粒细化强化和析出强化是主要的强化机制。本研究结果为实现材料的最佳强度-延展性匹配和指导后续退火处理提供了有效途径。
    Nanocrystalline (NC) structure can lead to the considerable strengthening of metals and alloys. Obtaining appropriate comprehensive mechanical properties is always the goal of metallic materials. Here, a nanostructured Al-Zn-Mg-Cu-Zr-Sc alloy was successfully processed by high-pressure torsion (HPT) followed by natural aging. The microstructures and mechanical properties of the naturally aged HPT alloy were analyzed. The results show that the naturally aged HPT alloy primarily consists of nanoscale grains (~98.8 nm), nano-sized precipitates (20-28 nm in size), and dislocations (1.16 × 1015 m-2), and exhibits a high tensile strength of 851 ± 6 MPa and appropriate elongation of 6.8 ± 0.2%. In addition, the multiple strengthening modes that were activated and contributed to the yield strength of the alloy were evaluated according to grain refinement strengthening, precipitation strengthening, and dislocation strengthening, and it is shown that grain refinement strengthening and precipitation strengthening are the main strengthening mechanisms. The results of this study provide an effective pathway for achieving the optimal strength-ductility match of materials and guiding the subsequent annealing treatment.
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  • 文章类型: Journal Article
    菊花cv。Fubaiju,这项研究使用了中国南方具有高营养和保健功能的传统茶。通过Box-Behnken设计响应面实验,获得了一种新型菊花米酒(FRW)的优化生产条件。用0.68%的菊花开发了感官品质最好的FRW,0.79%的九曲和0.81:1的液固比。与米酒(RW)对照相比,总酚类和类黄酮含量,以及FRW的抗氧化活性显著增加。GC-MS分析表明,更多的风味化合物,包括醇,醛类,酸,在FRW中检测到酯。在老化过程中,发现抗氧化物质,抗氧化活性和风味物质下降,酒体趋于均质化。储存6个月后,FRW的整体感官质量更加和谐,具有特殊的花蜜味道,与传统RW相比,显着改善了风味特性和功能。
    Chrysanthemum morifolium cv. Fubaiju, a traditional tea in southern China with high nutritional and health functions was used in this study. Optimized production conditions of a novel chrysanthemum rice wine (FRW) were obtained by the Box-Behnken design response surface experiment. FRW with best sensory quality was developed with 0.68% chrysanthemum, 0.79% Jiuqu and 0.81:1 liquid-to-solid ratio. Compared with rice wine (RW) control, the total phenolic and flavonoid contents, as well as antioxidant activity of the FRW increased significantly. GC-MS analysis showed that more flavor compounds including alcohols, aldehydes, acids, and esters were detected in FRW. During the aging process, it was found that the antioxidant substances, the antioxidant activity and the flavor substances decreased, with the wine body tending to be homogenized. After 6 months of storage, overall sensory quality of FRW was more harmonious, with special nectar taste, which dramatically improved the flavor characteristics and functionality compared with traditional RW.
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  • 文章类型: Journal Article
    为了便于2219铝合金薄壁构件的制造,淬火-成形-时效(Q-F-A)工艺已越来越多地使用。然而,淬火后自然时效(NA)显著影响该合金的冷成形性能。在这项研究中,实验研究了NA时间对2219铝合金冷成形性能的影响。结果表明,NA可以削弱Portevin-LeChatelier(PLC)效应,从而降低其对合金冷成形性能的影响。当老化时间达到2年时,PLC效应变得不明显。2219铝合金的屈服强度随时效时间单调增加,而伸长率先迅速增加后下降。经过2年的老化时间,屈服强度比新淬火合金提高了28.6%。应变硬化指数和硬化系数表明,短期NA(小于4天)增加了加工硬化率,而长期NA减少了它。显微组织分析表明,NA对2219铝合金的强化作用主要是由于G.P.区的生长和θ″相的析出。NA沉淀行为也会引起溶质原子的聚集,削弱PLC效应。
    To facilitate the manufacturing of the thin-walled components of 2219 aluminum alloy, the quenching-forming-aging (Q-F-A) process has been increasingly utilized. However, natural aging (NA) after quenching significantly affects the cold forming performance of this alloy. In this study, experiments are conducted to investigate the effect of NA time on the cold forming performance of 2219 aluminum alloy. The results indicate that NA can weaken the Portevin-Le Chatelier (PLC) effect, thereby reducing its influence on the cold forming performance of the alloy. The PLC effect becomes indistinct when the aging time reaches 2 years. The yield strength of 2219 aluminum alloy increases monotonically with aging time, while the elongation first increases rapidly and then decreases. After an aging time of 2 years, the yield strength increases by 28.6% from that of newly quenched alloys. The strain hardening index and hardening coefficient indicate that short-term NA (less than 4 days) increases the work hardening rate, while long-term NA reduces it. Microstructural analysis shows that the strengthening effect of NA on 2219 aluminum alloy is mainly due to the growth of G.P. zones and the precipitation of θ″ phases. The NA precipitation behavior can also cause the aggregation of solute atoms and weaken the PLC effect.
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  • 文章类型: Journal Article
    肾功能障碍在衰老引起的全身器官损伤中尤为重要。本研究利用代谢组学通过代谢产物的鉴定和代谢途径的表征来探索衰老过程中肾功能障碍的机制。我们分析了3月龄和24月龄雄性昆明种小鼠的血清生化和肾脏组织病理学,发现老年小鼠有炎性病变,纤维化加重,和功能损害。高分辨率非靶向代谢组学分析显示,小鼠肾脏和尿液中的内源性代谢产物被25和20种代谢产物显著改变,分别。对这些差异代谢物的途径分析揭示了六个关键的信号通路,即,D-谷氨酰胺和D-谷氨酸代谢,嘌呤代谢,柠檬酸盐循环[三羧酸(TCA)循环],组氨酸代谢,丙酮酸代谢,和乙醛酸和二羧酸代谢。这些途径涉及氨基酸代谢,碳水化合物代谢,和核苷酸代谢,这些可以导致免疫调节,炎症反应,氧化应激损伤,细胞功能障碍,和生物能源失调,它们与衰老和肾功能不全密切相关。我们还筛选了尿液中的9种敏感代谢物作为衰老过程中肾功能损害的潜在生物标志物,以确定其在老年肾损害中的治疗目标,并提高老年肾损伤的风险评估水平。
    Kidney dysfunction is particularly important in systemic organ injuries caused by aging. Metabolomics are utilized in this study to explore the mechanism of kidney dysfunction during aging by the identification of metabolites and the characterization of metabolic pathways. We analyzed the serum biochemistry and kidney histopathology of male Kunming mice aged 3 months and 24 months and found that the aged mice had inflammatory lesions, aggravated fibrosis, and functional impairment. A high-resolution untargeted metabolomics analysis revealed that the endogenous metabolites in the kidneys and urine of the mice were significantly changed by 25 and 20 metabolites, respectively. A pathway analysis of these differential metabolites revealed six key signaling pathways, namely, D-glutamine and D-glutamate metabolism, purine metabolism, the citrate cycle [tricarboxylic acid (TCA) cycle], histidine metabolism, pyruvate metabolism, and glyoxylate and dicarboxylate metabolism. These pathways are involved in amino acid metabolism, carbohydrate metabolism, and nucleotide metabolism, and these can lead to immune regulation, inflammatory responses, oxidative stress damage, cellular dysfunction, and bioenergy disorders, and they are closely associated with aging and kidney insufficiency. We also screened nine types of sensitive metabolites in the urine as potential biomarkers of kidney dysfunction during the aging process to confirm their therapeutic targets in senior-induced kidney dysfunction and to improve the level of risk assessment for senile kidney injury.
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