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Ag/β-Mo_(2)C催化逆水煤气变换反应性能及其机理研究
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作者 范帅 丁巍 +5 位作者 孙振宇 戴咏川 么志伟 宋官龙 马金玉 杨生文 《石油学报(石油加工)》 北大核心 2026年第2期357-367,共11页
采用程序升温碳化法合成β-Mo_(2)C载体,再通过沉积-沉淀法制备不同Ag负载量的系列Ag/β-Mo_(2)C催化剂。借助XRD、BET、TEM和XPS等手段对Ag/β-Mo_(2)C催化剂的物化性质进行表征,采用微型加氢反应装置对催化剂的逆水煤气变换(RWGS)反... 采用程序升温碳化法合成β-Mo_(2)C载体,再通过沉积-沉淀法制备不同Ag负载量的系列Ag/β-Mo_(2)C催化剂。借助XRD、BET、TEM和XPS等手段对Ag/β-Mo_(2)C催化剂的物化性质进行表征,采用微型加氢反应装置对催化剂的逆水煤气变换(RWGS)反应的催化性能进行评价。结果表明:β-Mo_(2)C载体具有六方密堆积的晶体结构,负载Ag后催化剂的结晶度较纯相β-Mo_(2)C提升1.38百分点,其中,0.5%Ag/β-Mo_(2)C催化剂中Ag的锚定作用使低负载量的Ag纳米粒子具有高分散性且孔结构良好;在H_(2)/CO_(2)体积比3/1、质量空速24000 h^(-1)的条件下,RWGS反应在300℃低温区CO选择性为61.86%,在600℃高温区CO选择性为97.44%,同时拥有高CO_(2)转化率52.37%,说明此类催化剂在RWGS反应中具有良好的催化活性;Ag的引入优化了Mo_(2)C电子结构,调节了Mo_(2)C的电子密度,提升了CO_(2)的吸附与活化能力,在提高催化剂热稳定性的同时可替代贵金属催化剂,降低了工业应用成本。 展开更多
关键词 沉积-沉淀法 碳化钼 ag纳米粒子 逆水煤气变换反应 CO选择性
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固溶处理对Mg-9Gd-4Y-0.4Zr-0.2Ag镁合金组织和力学性能的影响
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作者 李旻昊 万步炎 +3 位作者 卢立伟 黄谦仁 金永平 刘德顺 《材料热处理学报》 北大核心 2026年第2期88-98,共11页
采用光学显微镜、扫描电镜、X射线衍射和万能实验机等研究了固溶处理温度和时间对Mg-9Gd-4Y-0.4Zr-0.2Ag镁合金显微组织与力学性能的影响。结果表明:当固溶处理工艺为520℃×22 h时,合金具有较好的力学性能,其屈服抗拉强度为154.40 ... 采用光学显微镜、扫描电镜、X射线衍射和万能实验机等研究了固溶处理温度和时间对Mg-9Gd-4Y-0.4Zr-0.2Ag镁合金显微组织与力学性能的影响。结果表明:当固溶处理工艺为520℃×22 h时,合金具有较好的力学性能,其屈服抗拉强度为154.40 MPa、极限抗拉强度为270.04 MPa、平均硬度为128.43 HV0.5,其强化主要来源于固溶强化;固溶处理促使合金的平均晶粒尺寸由13.56μm增至32.89μm,但静态再结晶程度的加深,显著改善合金的组织均匀性,晶粒有向等轴晶转变的趋势,此外,部分共晶相呈粒状弥散分布于基体,这些相的出现有利于合金强度的提升;固溶处理前,合金中的Y和Zr存在聚集区,Gd与Ag呈现弥散分布;固溶处理后,合金中的第二相占比一开始略微增多,但随着固溶温度升高及时间延长,其总量减少,种类发生变化,Gd与Ag逐渐聚集,并与Mg、Y和Zr的分布形状贴近并交叠,AgY与稳定的Mg5Gd在第二相中占比也随之增加。 展开更多
关键词 Mg-9Gd-4Y-0.4Zr-0.2ag镁合金 固溶处理 第二相 显微组织 力学性能
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基于森林火灾风险的AG600消防飞机机场选址研究
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作者 王诗琪 孙智 +2 位作者 陈涛 朱培 张剑高 《控制与决策》 北大核心 2026年第2期531-542,共12页
针对消防飞机的机场选址问题,构建基于森林火灾风险因子的多目标规划模型,旨在最小化总任务时间与经济成本.该模型综合考虑森林火灾风险、灭火资源需求、消防飞机性能参数及部署运营成本+等多种因素,为提升高风险区域的优先覆盖能力,引... 针对消防飞机的机场选址问题,构建基于森林火灾风险因子的多目标规划模型,旨在最小化总任务时间与经济成本.该模型综合考虑森林火灾风险、灭火资源需求、消防飞机性能参数及部署运营成本+等多种因素,为提升高风险区域的优先覆盖能力,引入基于风速、相对湿度和植被覆盖度的森林火灾风险因子.此外,针对所构建的高维度整数多目标优化模型,引入自适应因子和双层决策选择策略,以提升NSGA-Ⅱ算法的求解能力.以广西地区为例,利用ArcGIS进行空间数据处理,并采用改进的NSGA-Ⅱ算法对选址模型进行求解.研究结果表明:改进的NSGA-Ⅱ算法能够有效提升求解速度和求解质量;在广西地区,柳州白莲机场部署2架AG600消防飞机为最优方案,其解的相对接近度较其他方案提高39%.所提出基于森林火灾风险因子构建的机场选址模型可为我国AG600消防飞机机场选址和部署提供理论依据和参考. 展开更多
关键词 机场选址 多目标优化 航空消防 森林火灾 森林火灾风险因子 消防飞机 ag600
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Mice with postsurgical pain exhibit age-dependent spinal microglial activation and inhibitory synapse loss 被引量:1
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作者 WANG Jia-Ning SHEN Yu +2 位作者 WANG Shi-Hao LIAO Ping JIANG Ruo-Tian 《生理学报》 北大核心 2026年第1期182-194,共13页
Persistent postsurgical pain is a major clinical concern,especially in the aging population,who represent a growing proportion of surgical patients.Although age is a known pain risk factor,the mechanisms driving age-r... Persistent postsurgical pain is a major clinical concern,especially in the aging population,who represent a growing proportion of surgical patients.Although age is a known pain risk factor,the mechanisms driving age-related vulnerability to chronic postoperative pain remain poorly understood.This study aims to investigate how aging influences the resolution of postoperative pain and to elucidate the roles of microglial activation and synaptic remodeling in the spinal dorsal horn.A plantar incision model in young(3-month-old)and aged(18-month-old)male and female mice was used to mimic postoperative pain conditions.Mechanical and thermal hypersensitivity at various postoperative intervals were assessed by von Frey and Hargreaves tests.Microglial activation and inhibitory/excitatory synaptic densities in the spinal dorsal horn were evaluated using immunofluorescence and 3D reconstruction with Imaris software.On postoperative day(POD)3,both age groups exhibited reduced pain thresholds on the ipsilateral side,along with microglial activation in the dorsal horn.On POD 7,pain thresholds in young mice had returned to baseline with no significant microglial activation,while aged mice showed sustained reduction in pain thresholds,continuous microglial activation,and significant loss of inhibitory synapses without detectable changes in excitatory synapse density.These findings are consistent across both sexes,with no sex-related differences.Collectively,these results suggest that aging is associated with persistent postoperative pain,which correlates with microglial activation and inhibitory synapse loss.These insights advance our understanding of age-related pain vulnerability and may inform the development of more effective,targeted,and age-specific therapeutic strategies to prevent or alleviate persistent postoperative pain in elderly patients. 展开更多
关键词 incisional pain agING spinal dorsal horn MICROGLIA inhibitory synapses
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痘苗病毒天坛株感染AG6小鼠脑病模型的建立与初步分析
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作者 杨琳 金梦 +2 位作者 吴汗青 李顺 周晓辉 《实验动物与比较医学》 2026年第1期3-10,共8页
目的构建痘苗病毒天坛株(vaccinia virus Tiantan strain,VTT)感染AG6小鼠脑病动物模型。方法通过以0.01的感染复数(multiplicity of infection,MOI)感染Vero细胞,扩增VTT并进行浓缩和滴定,孵育72 h后,收集含病毒的细胞进行浓缩;将浓缩... 目的构建痘苗病毒天坛株(vaccinia virus Tiantan strain,VTT)感染AG6小鼠脑病动物模型。方法通过以0.01的感染复数(multiplicity of infection,MOI)感染Vero细胞,扩增VTT并进行浓缩和滴定,孵育72 h后,收集含病毒的细胞进行浓缩;将浓缩的病毒悬浮液连续稀释(10倍梯度)并加入到含有形成致密单层Vero细胞的6孔板中进行噬斑实验,计数每孔形成的空斑数目,并根据样品的稀释倍数计算病毒滴度。将14只5~6周龄的AG6小鼠(雌雄各半,并按性别分笼饲养)随机分为对照组(n=3,PBS)、低接种量组(n=6,1×10^(5)PFU)和高接种量组(n=5,5×10^(5)PFU)。将小鼠经异氟烷吸入麻醉后,进行滴鼻感染。每日观察各组小鼠精神状态,记录其体重及死亡情况,并在感染后第13天经尾静脉注射2%伊文思蓝(Evans Blue)(4 mL/kg体重)以评估各组小鼠血脑屏障(blood-brain barrier,BBB)的破损情况,然后收集小鼠脑组织样本进行星形胶质细胞和小胶质细胞活化的免疫荧光分析。结果纯化后的VTT滴度为1×10^(7)PFU/mL。与对照组相比,低接种量组小鼠的体重无明显变化,且未出现死亡;高接种量组小鼠在感染后第5天开始体重显著减轻(P<0.05),并伴有致死结果。感染后第13天,低接种量组小鼠的脑组织中未检测到伊文思蓝外渗,高接种量组小鼠的嗅球区域显示出明显的蓝色染色,提示BBB破裂。免疫荧光分析显示,感染后第13天,低接种量组小鼠嗅球区域星形胶质细胞和小胶质细胞没有明显增殖,高接种量组小鼠中可观察到明显的胶质细胞活化。结论成功建立VTT感染AG6小鼠的脑病动物模型,其特征是小鼠BBB损伤和特异性定位于嗅球区域的反应性胶质增生(表现为星形胶质细胞和小胶质细胞增生)。 展开更多
关键词 痘苗病毒天坛株 脑病动物模型 血脑屏障 胶质细胞 ag6小鼠
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纳米SiO_(2)和纳米Ag对水泥基材料力学性能和压敏性能的影响
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作者 朱玉胜 姜锦磊 +1 位作者 孙敏 方有珍 《混凝土与水泥制品》 2026年第1期24-28,36,共6页
研究了纳米SiO_(2)掺量(0、0.5%、1.0%、1.5%)对水泥基材料力学性能的影响,优选出了最佳掺量。在此基础上,进一步通过掺入纳米Ag设计制备了自感知水泥基材料,研究了其在不同应力环境(等幅值循环加载、变幅值循环加载)下的压敏性能。结... 研究了纳米SiO_(2)掺量(0、0.5%、1.0%、1.5%)对水泥基材料力学性能的影响,优选出了最佳掺量。在此基础上,进一步通过掺入纳米Ag设计制备了自感知水泥基材料,研究了其在不同应力环境(等幅值循环加载、变幅值循环加载)下的压敏性能。结果表明:随着纳米SiO_(2)掺量的增加,试件的28 d抗折、抗压强度均先增大后减小,最佳掺量为1.0%;在等幅值循环加载工况下,试件的电阻率变化率表现为稳定的周期性波动趋势,且电阻率变化率与外力之间具有高度线性相关性,说明该水泥基材料在动态应力条件下具有优异的压敏性能和长期稳定性;在变幅值循环加载工况下,试件的电阻率变化率波动范围为-50%~-10%,其中,试件在高幅值阶段的导电网络虽然发生了重组和变化,但仍保持良好的周期性和完整性。 展开更多
关键词 自感知水泥基材料 纳米SiO_(2) 纳米ag 力学性能 压敏性能 稳定性 应力环境
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构建高催化活性的BiVO_(4)@Ag复合材料
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作者 蔡旭鹏 王月荣 +4 位作者 蔡依辰 洪先健 郭少波 郭小华 季晓晖 《化学试剂》 2026年第1期28-35,共8页
针对钒酸铋(BiVO_(4))光催化剂存在的载流子复合率高、表面反应动力学迟缓等问题,以球形BiVO_(4)为基底,通过3种不同光化学还原方法(直接还原法、银氨配合物-还原法、溴化钾调控还原法)构建BiVO_(4)@Ag-6%复合材料,系统探究不同负载方... 针对钒酸铋(BiVO_(4))光催化剂存在的载流子复合率高、表面反应动力学迟缓等问题,以球形BiVO_(4)为基底,通过3种不同光化学还原方法(直接还原法、银氨配合物-还原法、溴化钾调控还原法)构建BiVO_(4)@Ag-6%复合材料,系统探究不同负载方式对材料微观结构及光催化性能的影响。利用透射电子显微镜(TEM)、X射线光电子能谱(XPS)、X射线衍射(XRD)、紫外-可见漫反射光谱(UV-Vis DRS)以及电化学测试等对复合材料的结构和性质进行了系统表征。实验结果表明,通过溴化钾调控还原法制备的目标材料具有较好催化活性。这是由于利用AgBr配合物缓释Ag^(+)机制,显著优化了Ag纳米颗粒(Ag NPs)的分散度及界面结合强度,其光催化降解Cr^(6+)和罗丹明B(RhB)的活性最佳(Cr^(6+)在20 min内完全降解,RhB降解效率较纯BiVO_(4)提升明显)。结合表征分析,其优异性能归因于Ag NPs的等离子体共振效应(SPR)和肖特基势垒的协同作用,能够有效抑制载流子复合,并加速界面电荷传输。 展开更多
关键词 BiVO_(4) 银纳米颗粒(ag NPs) 光催化降解 等离子体共振效应(SPR) 降解率
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Quantifying Global Black Carbon Aging Responses to Emission Reductions Using a Machine Learning-based Climate Model 被引量:1
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作者 Wenxiang SHEN Minghuai WANG +5 位作者 Junchang WANG Yawen LIU Xinyi DONG Xinyue SHAO Man YUE Yaman LIU 《Advances in Atmospheric Sciences》 2026年第2期361-372,I0004-I0009,共18页
Countries around the world have been making efforts to reduce pollutant emissions. However, the response of global black carbon(BC) aging to emission changes remains unclear. Using the Community Atmosphere Model versi... Countries around the world have been making efforts to reduce pollutant emissions. However, the response of global black carbon(BC) aging to emission changes remains unclear. Using the Community Atmosphere Model version 6 with a machine-learning-integrated four-mode version of the Modal Aerosol Module, we quantify global BC aging responses to emission reductions for 2011–2018 and for 2050 and 2100 under carbon neutrality. During 2011–18, global trends in BC aging degree(mass ratio of coatings to BC, R_(BC)) exhibited marked regional disparities, with a significant increase in China(5.4% yr^(-1)), which contrasts with minimal changes in the USA, Europe, and India. The divergence is attributed to opposing trends in secondary organic aerosol(SOA) and sulfate coatings, driven by regional changes in the emission ratios of corresponding coating precursors to BC(volatile organic compounds-VOCs/BC and SO_(2)/BC). Projections under carbon neutrality reveal that R_(BC) will increase globally by 47%(118%) in 2050(2100), with strong convergent increases expected across major source regions. The R_(BC) increase, primarily driven by enhanced SOA coatings due to sharper BC reductions relative to VOCs, will enhance the global BC mass absorption cross-section(MAC) by 11%(17%) in 2050(2100).Consequently, although the global BC burden will decline sharply by 60%(76%), the enhanced MAC partially offsets the magnitude of the decline in the BC direct radiative effect, resulting in the moderation of global BC DRE decreases to 88%(92%) of the BC burden reductions in 2050(2100). This study highlights the globally enhanced BC aging and light absorption capacity under carbon neutrality, thereby partly offsetting the impact of BC direct emission reductions on future changes in BC radiative effects globally. 展开更多
关键词 black carbon aging trend emission reduction carbon neutrality machine learning
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Ag/TiO_(2)微胶囊的制备及其在纺织中的应用
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作者 何奕鸣 尚润玲 堵国君 《轻纺工业与技术》 2026年第1期10-12,19,共4页
为了赋予纯棉织物持久的抗菌和防紫外线性能,文章采用光化学还原法制备了Ag/TiO_(2)纳米颗粒,进而利用乳化-交联法,将Ag/TiO_(2)纳米颗粒乳化后的分散液与壳聚糖溶液交联固化,制备了Ag/TiO_(2)微胶囊。实验中,采用Ag/TiO_(2)微胶囊对纯... 为了赋予纯棉织物持久的抗菌和防紫外线性能,文章采用光化学还原法制备了Ag/TiO_(2)纳米颗粒,进而利用乳化-交联法,将Ag/TiO_(2)纳米颗粒乳化后的分散液与壳聚糖溶液交联固化,制备了Ag/TiO_(2)微胶囊。实验中,采用Ag/TiO_(2)微胶囊对纯棉织物进行整理,对整理前后样品的抗菌和防紫外线性能分别进行测试后,结果表明:经Ag/TiO_(2)微胶囊整理后的纯棉织物具有优异且持久的抗菌性和防紫外线性能;经过80次水洗后,其对金黄色葡萄球菌和大肠杆菌的抑菌率均可以达到98%,对白色念珠菌的抑菌率可以达到70%,T(UVA)AV可达到2.4%,UPF可达到87.9。 展开更多
关键词 ag/TiO_(2) 微胶囊 棉织物 抗菌性 防紫外线性能
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Research progress in 7-ketocholesterol and age-related macular degeneration
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作者 Luo Qin Fu Changzhen Liu Qingping 《中华实验眼科杂志(中英文)》 北大核心 2026年第1期85-97,共13页
Age-related macular degeneration(AMD)is the leading cause of irreversible vision loss in older adults,with early-stage features including subretinal lipid deposits and progressing to retinal geographic atrophy and cho... Age-related macular degeneration(AMD)is the leading cause of irreversible vision loss in older adults,with early-stage features including subretinal lipid deposits and progressing to retinal geographic atrophy and choroidal neovascularization in advanced stages.The dysregulation of ocular lipid metabolism,oxidative stress,and inflammation are critical risk factors for AMD pathogenesis.7-ketocholesterol(7-KC),a hallmark of ocular lipid metabolism disorders,is a significant component of subretinal lipid deposits in AMD patients,exhibiting toxicity to retinal cells and exacerbating lipotoxic aging.This review elaborates on the biosynthesis and metabolism of 7-KC in the retina,investigates its detoxification mechanisms by examining its binding proteins,and summarizes recent progress on kinase signaling pathways induced by 7-KC through inflammatory cytokines and intracellular effectors.The aim is to pinpoint potential pharmacological targets,nutritional compounds,and synthetic molecules to explore the potential of targeting 7-KC for AMD treatment. 展开更多
关键词 age-related macular degeneration 7-ketocholesterol agING Binding protein INFLAMMATION Pharmacological targets
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AGS布置形式对前舱散热性能及空调能耗的影响研究
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作者 胡晓辉 赵梦迪 +2 位作者 郭俊江 上官郑伟 路昭 《汽车技术》 北大核心 2026年第2期56-62,共7页
采用一维-三维联合仿真的计算方法,探究了主动进气格栅(AGS)布置形式对前舱进气量、冷却模块散热量以及空调压缩机能耗的影响。研究发现:AGS叶片与格栅距离处于57~97 mm时,正对与非正对布置对散热性能及能耗的影响趋于一致,进气量衰减... 采用一维-三维联合仿真的计算方法,探究了主动进气格栅(AGS)布置形式对前舱进气量、冷却模块散热量以及空调压缩机能耗的影响。研究发现:AGS叶片与格栅距离处于57~97 mm时,正对与非正对布置对散热性能及能耗的影响趋于一致,进气量衰减幅度约为2.4%,散热量降低幅度低于1%,压缩机能耗几乎无影响;距离小于57 mm(靠近格栅)时,正对布置的方式优于错开布置,体现在相对于错开布置进气量提升3.16%,散热量提升约2%,压缩机能耗降低约2%;距离大于97 mm(靠近冷却模块)时,采用错开布置形式更有利于降低AGS叶片造成的进气量衰减。 展开更多
关键词 agS叶片布置形式 进气量 散热量 空调能耗
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Analysis of DC Aging Characteristics of Stable ZnO Varistors Based on Voronoi Network and Finite Element Simulation Model
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作者 ZHANG Ping LU Mingtai +1 位作者 LU Tiantian YUE Yinghu 《材料导报》 北大核心 2026年第2期20-28,共9页
In modern ZnO varistors,traditional aging mechanisms based on increased power consumption are no longer relevant due to reduced power consumption during DC aging.Prolonged exposure to both AC and DC voltages results i... In modern ZnO varistors,traditional aging mechanisms based on increased power consumption are no longer relevant due to reduced power consumption during DC aging.Prolonged exposure to both AC and DC voltages results in increased leakage current,decreased breakdown voltage,and lower nonlinearity,ultimately compromising their protective performance.To investigate the evolution in electrical properties during DC aging,this work developed a finite element model based on Voronoi networks and conducted accelerated aging tests on commercial varistors.Throughout the aging process,current-voltage characteristics and Schottky barrier parameters were measured and analyzed.The results indicate that when subjected to constant voltage,current flows through regions with larger grain sizes,forming discharge channels.As aging progresses,the current focus increases on these channels,leading to a decline in the varistor’s overall performance.Furthermore,analysis of the Schottky barrier parameters shows that the changes in electrical performance during aging are non-monotonic.These findings offer theoretical support for understanding the aging mechanisms and condition assessment of modern stable ZnO varistors. 展开更多
关键词 ZnO varistors Voronoi network DC aging finite element method(FEM) current distribution double Schottky barrier theory
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Melatonin and mitochondrial stress: New insights into age-related neurodegeneration
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作者 Silvia Carloni Francesca Luchetti +3 位作者 Maria Gemma Nasoni Walter Balduini Walter Manucha Russel J.Reiter 《Neural Regeneration Research》 2026年第4期1564-1565,共2页
Aging,mitochondria,and neurodegenerative diseases:Aging is often viewed as the buildup of changes that lead to the gradual transformations associated with getting older,along with a rising likelihood of disease and mo... Aging,mitochondria,and neurodegenerative diseases:Aging is often viewed as the buildup of changes that lead to the gradual transformations associated with getting older,along with a rising likelihood of disease and mortality.Although organis m-wide deterioration is observed during aging,organs with high metabolic demand,such as the brain,are more vulnerable. 展开更多
关键词 buildup changes neurodegenerative diseases aging neurodegenerative diseases MITOCHONDRIA mitochondrial stress MELATONIN age related neurodegeneration agING
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Synaptic mitochondria in aging and neurodegenerative diseases:Functional decline and vulnerability
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作者 Karina A.Cicali Angie K.Torres Cheril Tapia-Rojas 《Neural Regeneration Research》 2026年第6期2145-2152,共8页
Aging is a physiological and complex process produced by accumulative age-dependent cellular damage,which significantly impacts brain regions like the hippocampus,an essential region involved in memory and learning.A ... Aging is a physiological and complex process produced by accumulative age-dependent cellular damage,which significantly impacts brain regions like the hippocampus,an essential region involved in memory and learning.A crucial factor contributing to this decline is the dysfunction of mitochondria,particularly those located at synapses.Synaptic mitochondria are specialized organelles that produce the energy required for synaptic transmission but are also important for calcium homeostasis at these sites.In contrast,non-synaptic mitochondria primarily involve cellular metabolism and long-term energy supply.Both pools of mitochondria differ in their form,proteome,functionality,and cellular role.The proper functioning of synaptic mitochondria depends on processes such as mitochondrial dynamics,transport,and quality control.However,synaptic mitochondria are particularly vulnerable to age-associated damage,characterized by oxidative stress,impaired energy production,and calcium dysregulation.These changes compromise synaptic transmission,reducing synaptic activity and cognitive decline during aging.In the context of neurodegenerative diseases such as Alzheimer’s,Parkinson’s,and Huntington’s,the decline of synaptic mitochondrial function is even more pronounced.These diseases are marked by pathological protein accumulation,disrupted mitochondrial dynamics,and heightened oxidative stress,accelerating synaptic dysfunction and neuronal loss.Due to their specialized role and location,synaptic mitochondria are among the first organelles to exhibit dysfunction,underscoring their critical role in disease progression.This review delves into the main differences at structural and functional levels between synaptic and non-synaptic mitochondria,emphasizing the vulnerability of synaptic mitochondria to the aging process and neurodegeneration.These approaches highlight the potential of targeting synaptic mitochondria to mitigate age-associated cognitive impairment and synaptic degeneration.This review emphasizes the distinct vulnerabilities of hippocampal synaptic mitochondria,highlighting their essential role in sustaining brain function throughout life and their promise as therapeutic targets for safeguarding the cognitive capacities of people of advanced age. 展开更多
关键词 agING HIPPOCAMPUS MEMORY MITOCHONDRIA synaptic mitochondria
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Metabolite Profiling and Skin Anti-Aging Potential of Astragalus sarcocolla:Antioxidant,Enzyme Inhibitory,and Computational Insights
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作者 Shaimaa R.Ahmed Omnia M.Hendawy +2 位作者 Sumera Qasim Hanan Khojah Ambreen Malik Uttra 《Phyton-International Journal of Experimental Botany》 2026年第2期119-138,共20页
The study evaluated the skin anti-aging activity of Astragalus sarcocolla leaves extract(ASE)by assessing its antioxidant and inhibitory effect activity on matrix metalloproteinase(MMP),collagenase,elastase,hyaluronid... The study evaluated the skin anti-aging activity of Astragalus sarcocolla leaves extract(ASE)by assessing its antioxidant and inhibitory effect activity on matrix metalloproteinase(MMP),collagenase,elastase,hyaluronidase,and tyrosinase in relation to its chemical composition.Ultra Performance Liquid Chromatography-Mass Spectrometry(UPLC-MS)identified 27 metabolites(15 flavonoids,8 phenolic acids and their derivatives,and 4 coumarins).ASE showed strong antioxidant capacity in DPPH(IC_(50)value of 26.05μg/mL)and FRAP(2433μM FeSO_(4)/g extract)assays.The extract inhibited MMP-1 and MMP-9 in a concentration-dependent manner and suppressed collagenase,elastase,hyaluronidase,and tyrosinase activities(IC_(50)=35.038,40.748,61.389,and 30.980μg/mL,respectively).A network pharmacology study was conducted to uncover the mechanisms responsible for skin anti-aging effects,and molecular docking further evaluated interactions of key metabolites with hub targets.Twenty-one bioactive metabolites,selected based on oral bioavailability and drug-likeness,highlighted cinnamic acid,acacetin,luteolin,kaempferol,and apigenin as key compounds.MMP-9,ESR1,PTGS-2,and EGFR were identified as main targets.Docking studies revealed that acacetin and apigenin have stronger binding affinities to MMP-9,PTGS-2,and EGFR than other constituents.These findings suggest that ASE may serve as a natural multi-target skin anti-aging remedy with potential cosmetic applications. 展开更多
关键词 Astragalus sarcocolla metabolite profiling aging METALLOPROTEINASE network pharmacology
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Fitness and exercise effects on brain age:A randomized clinical trial
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作者 Lu Wan Cristina Molina-Hidalgo +11 位作者 Mary E.Crisafio George Grove Regina L.Leckie Thomas W.Kamarck Chaeryon Kang Mia DeCataldo Anna L.Marsland Matthew F.Muldoon Mark R.Scudder Javier Rasero Peter J.Gianaros Kirk I.Erickson 《Journal of Sport and Health Science》 2026年第2期41-51,共11页
Background:Midlife lifestyle factors,including physical activity,are associated with late-life brain health,yet the role of aerobic exercise on structural brain health in early and mid-adulthood remains poorly underst... Background:Midlife lifestyle factors,including physical activity,are associated with late-life brain health,yet the role of aerobic exercise on structural brain health in early and mid-adulthood remains poorly understood.This study aimed to examine the effect of aerobic exercise on structural brain age and to explore potential mediators.Methods:In a single-blind,12-month randomized clinical trial,130 healthy participants aged 26-58 years were randomized into a moderate-to-vigorous intensity aerobic exercise group or a usual-care control group.The exercise group attended two supervised 60-min sessions per week in a laboratory setting plus engaged in home-based exercise to achieve 150 min of exercise per week.Brain-predicted age difference(brain-PAD)and cardiorespiratory fitness(CRF)were assessed at baseline and 12 months.Both intention-to-treat(ITT)and completers analyses(including participants who completed post-intervention assessments)were performed.Results:The 130 participants(67.7%female)had an age of 41.28±9.93 years(mean±SD).At baseline,higher CRF(peak oxygen uptake,VO_(2peak))was associated with smaller brain-PAD(β=-0.309,p=0.012).After the intervention,the exercise group showed a decrease in brainPAD(estimated mean difference(EMD)=-0.60;95%confidence interval(95%CI):-1.15 to-0.04;p=0.034)compared to the control group(EMD=0.35;95%CI:-0.21 to 0.92;p=0.217);time×group interaction(between-group difference(BGD)=-0.95;95%CI:-1.72 to-0.17;p=0.019).VO2peak improved in the exercise group(EMD=1.60;95%CI:0.29-2.90;p=0.017)compared to the control group(EMD=-0.78;95%CI:-2.17 to 0.60;p=0.265);time×group interaction(BGD=2.38;95%CI:0.52-4.25;p=0.015).Body composition,blood pressure,and brain-derived neurotrophic factor levels were unaffected.None of the proposed pathways statistically mediated the effect of exercise on brain-PAD.The results from completers were similar.Conclusion:Engaging in 12 months of moderate-to-vigorous exercise reduced brain-PAD in early-to-midlife adults.The pathways by which these effects occur remain unknown. 展开更多
关键词 Aerobic exercise agING BRAIN Cardiorespiratory fitness
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Alpha-synuclein-induced upregulation of SKI family transcriptional corepressor 1: A new player in aging and Parkinson's disease?
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作者 Lauren Barrett Rebekah Bevans +2 位作者 Aideen M.Sullivan Louise M.Collins Gerard W.O’Keeffe 《Neural Regeneration Research》 2026年第1期320-321,共2页
SKI family transcriptional corepressor 1(SKOR1also known as LbxCor1, Fussel15, or CORL1), is a member of the SKI family of proteins and is transcribed from a protein-coding gene located on chromosome 15 in humans, tha... SKI family transcriptional corepressor 1(SKOR1also known as LbxCor1, Fussel15, or CORL1), is a member of the SKI family of proteins and is transcribed from a protein-coding gene located on chromosome 15 in humans, that has a molecular weight of approximately 100 kDa. Skor1 is highly expressed in neurons in the central nervous system of both humans and rodents. 展开更多
关键词 Alpha Cor agING
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Systematic review of mitochondrial dysfunction and oxidative stress in aging:A focus on neuromuscular junctions
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作者 Senlin Chai Ning Zhang +8 位作者 Can Cui Zhengyuan Bao Qianjin Wang Wujian Lin Ronald Man Yeung Wong Sheung Wai Law Rebecca Schönmehl Christoph Brochhausen Wing Hoi Cheung 《Neural Regeneration Research》 2026年第5期1947-1960,共14页
Mitochondrial dysfunction and oxidative stress are widely regarded as primary drivers of aging and are associated with several neurodegenerative diseases.The degeneration of motor neurons during aging is a critical pa... Mitochondrial dysfunction and oxidative stress are widely regarded as primary drivers of aging and are associated with several neurodegenerative diseases.The degeneration of motor neurons during aging is a critical pathological factor contributing to the progression of sarcopenia.However,the morphological and functional changes in mitochondria and their interplay in the degeneration of the neuromuscular junction during aging remain poorly understood.A defined systematic search of the Pub Med,Web of Science and Embase databases(last accessed on October 30,2024)was conducted with search terms including'mitochondria','aging'and'NMJ'.Clinical and preclinical studies of mitochondrial dysfunction and neuromuscular junction degeneration during aging.Twentyseven studies were included in this systematic review.This systematic review provides a summary of morphological,functional and biological changes in neuromuscular junction,mitochondrial morphology,biosynthesis,respiratory chain function,and mitophagy during aging.We focus on the interactions and mechanisms underlying the relationship between mitochondria and neuromuscular junctions during aging.Aging is characterized by significant reductions in mitochondrial fusion/fission cycles,biosynthesis,and mitochondrial quality control,which may lead to neuromuscular junction dysfunction,denervation and poor physical performance.Motor nerve terminals that exhibit redox sensitivity are among the first to exhibit abnormalities,ultimately leading to an early decline in muscle strength through impaired neuromuscular junction transmission function.Parg coactivator 1 alpha is a crucial molecule that regulates mitochondrial biogenesis and modulates various pathways,including the mitochondrial respiratory chain,energy deficiency,oxidative stress,and inflammation.Mitochondrial dysfunction is correlated with neuromuscular junction denervation and acetylcholine receptor fragmentation,resulting in muscle atrophy and a decrease in strength during aging.Physical therapy,pharmacotherapy,and gene therapy can alleviate the structural degeneration and functional deterioration of neuromuscular junction by restoring mitochondrial function.Therefore,mitochondria are considered potential targets for preserving neuromuscular junction morphology and function during aging to treat sarcopenia. 展开更多
关键词 agING mitochondrial dysfunction neuromuscular junction oxidative stress SARCOPENIA systematic review
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Constitutive modeling of solvent plasticization and physical aging in glassy polymers
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作者 Xu CAO Kerong WU +1 位作者 Ji LIN Rui XIAO 《Applied Mathematics and Mechanics(English Edition)》 2026年第3期535-554,共20页
Glassy polymers are widely used in biomedical applications in a solvent environment,yet their long-term performance is governed by the competing effects of physical aging and solvent-induced plasticization.Here,we dev... Glassy polymers are widely used in biomedical applications in a solvent environment,yet their long-term performance is governed by the competing effects of physical aging and solvent-induced plasticization.Here,we develop a constitutive model that explicitly couples the solvent concentration,structural relaxation,and mechanical response.This framework is built on a multiplicative decomposition of deformation and an Eyring-type flow rule,with structural evolution described by an effective temperature.A generalized shift factor is introduced to quantify how the solvent concentration and effective temperature jointly affect the relaxation time,thereby integrating physical aging and plasticization.The model is subsequently applied to methacrylate(MA)-based copolymer networks immersed in phosphate-buffered saline for up to nine months.Simulations accurately capture key experimental features,including the strong softening of highly swellable networks,the partial recovery due to aging,and the mitigating role of hydrophobic crosslinking in reducing solvent uptake.While the current single-mode description cannot reproduce the full relaxation spectrum,it establishes an efficient framework for predicting the long-term mechanical performance under coupled environmental and mechanical loading.This study provides a constitutive description of solvent-swollen glassy polymers,offering mechanistic insight into the interplay between plasticization and aging.Beyond biomedical MA networks,this framework establishes a foundation for predicting the long-term performance of polymer glasses under coupled aqueous environmental and mechanical loading. 展开更多
关键词 glassy polymer SWELLING physical aging constitutive model
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Improving Efficiency of Light Pressure Electric Generator Using Graphene Oxide Nanospacer Between Ag Nanoparticles
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作者 Ha Young Lee Sung-Hyun Kim +3 位作者 Sun-Lyeong Hwang Hyung Soo Ahn Heedae Kim Sam Nyung Yi 《Carbon Energy》 2026年第1期38-47,共10页
Improving device efficiency is fundamental for advancing energy harvesting technology,particularly in systems designed to convert light energy into electrical output.In our previous studies,we developed a basic struct... Improving device efficiency is fundamental for advancing energy harvesting technology,particularly in systems designed to convert light energy into electrical output.In our previous studies,we developed a basic structure light pressure electric generator(Basic-LPEG),which utilized a layered configuration of Ag/Pb(Zr,Ti)O_(3)(PZT)/Pt/GaAs to generate electricity based on light-induced pressure on the PZT.In this study,we sought to enhance the performance of this Basic-LPEG by introducing Ag nanoparticles/graphene oxide(AgNPs/GO)composite units(NP-LPEG),creating upgraded harvesting device.Specifically,by depositing the AgNPs/GO units twice onto the Basic-LPEG,we observed an increase in output voltage and current from 241 mV and 3.1μA to 310 mV and 9.3μA,respectively,under a solar simulator.The increase in electrical output directly correlated with the intensity of the light pressure impacting the PZT,as well as matched the Raman measurements,finite-difference time-domain simulations,and COMSOL Multiphysics Simulation.Experimental data revealed that the enhancement in electrical output was proportional to the number of hot spots generated between Ag nanoparticles,where the electric field experienced substantial amplification.These results underline the effectiveness of AgNPs/GO units in boosting the light-induced electric generation capacity,thereby providing a promising pathway for high-efficiency energy harvesting devices. 展开更多
关键词 ag nanoparticles energy harvesting graphene oxide light pressure PIEZOELECTRIC
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