期刊文献+
共找到8,301篇文章
< 1 2 250 >
每页显示 20 50 100
固化单宁纤维素基气凝胶吸附还原Ag(I)行为研究
1
作者 陈颖 林昱灵 +4 位作者 吕源财 刘以凡 林春香 叶晓霞 刘明华 《中国环境科学》 EI CAS CSCD 北大核心 2024年第4期2083-2092,共10页
以纤维素为原料,在NaOH/尿素/H_(2)O溶解体系中通过交联作用将橡椀单宁固化在纤维素基体上,制得固化橡椀单宁纤维素基气凝胶(VTCA).通过SEM-EDS、FT-IR、XRD等对VTCA进行表征,并研究其对水溶液中Ag(I)的吸附行为.结果表明,VTCA具有明显... 以纤维素为原料,在NaOH/尿素/H_(2)O溶解体系中通过交联作用将橡椀单宁固化在纤维素基体上,制得固化橡椀单宁纤维素基气凝胶(VTCA).通过SEM-EDS、FT-IR、XRD等对VTCA进行表征,并研究其对水溶液中Ag(I)的吸附行为.结果表明,VTCA具有明显的三维网格多孔结构,孔隙率达到97.95%,在较宽的pH范围内(1~8)对Ag(I)均保持较高的吸附效率(>75%).吸附过程符合拟二级动力学模型和Langmuir吸附等温线模型,温度升高有利于吸附,最高理论吸附量为147.2mg/g.吸附还原研究机理表明,VTCA主要通过静电吸引和螯合作用将Ag(I)吸附到其表面,并通过单宁结构上的酚羟基将其原位还原为Ag^(0),证明VTCA具有良好的吸附还原性能,能够实现对水体中Ag(I)的回收. 展开更多
关键词 吸附 还原 纤维素基气凝胶 橡椀单宁 ag(i)
下载PDF
Ag/Bi_(2)O_(3)纳米块自供能紫外探测器的制备及性能
2
作者 方向明 周起成 +3 位作者 孙宇 乔志铭 耿秋丹 高世勇 《光学精密工程》 EI CAS CSCD 北大核心 2024年第5期653-660,共8页
为了实现在无外部供能下对紫外光的有效探测,基于Ag修饰的Bi_(2)O_(3)纳米块(Ag/Bi_(2)O_(3))纳米块制备了自供能紫外探测器。通过煅烧法制备Bi_(2)O_(3)纳米块,随后采用室温溶液法在其表面沉积Ag纳米粒子,进而成功制备了Ag/Bi_(2)O_(3... 为了实现在无外部供能下对紫外光的有效探测,基于Ag修饰的Bi_(2)O_(3)纳米块(Ag/Bi_(2)O_(3))纳米块制备了自供能紫外探测器。通过煅烧法制备Bi_(2)O_(3)纳米块,随后采用室温溶液法在其表面沉积Ag纳米粒子,进而成功制备了Ag/Bi_(2)O_(3)纳米块,且对所制备样品的晶体结构和微观形貌等进行了表征。结果表明,Ag/Bi_(2)O_(3)纳米块的平均尺寸约为1μm,且Ag纳米粒子随机分布在Bi_(2)O_(3)纳米块表面。将涂覆Ag/Bi_(2)O_(3)纳米块的FTO作为工作电极,并进一步构建了自供能紫外探测器。在365 nm的紫外光照射下,Ag/Bi_(2)O_(3)纳米块紫外探测器能在零偏压下实现对紫外光的快速检测,这证实其具有自供能特性。相比于Bi_(2)O_(3)纳米块紫外探测器,Ag/Bi_(2)O_(3)纳米块紫外探测器的光电流得到明显提升,上升和下降时间分别缩短至29.1 ms和40.2 ms,并具有良好的循环稳定性。 展开更多
关键词 紫外探测器 Bi_(2)O_(3)纳米块 ag纳米粒子 自供能探测
下载PDF
MIL-101(Cr)-NH_(2)负载Ag催化4-硝基苯酚加氢研究
3
作者 田喜强 孙宇航 +4 位作者 叶文静 董艳萍 蒋雅然 曾庆喜 孙红梅 《黑龙江大学工程学报(中英俄文)》 2024年第2期27-33,共7页
通过水热法制备出MIL-101(Cr)-NH_(2),以MIL-101(Cr)-NH_(2)为载体采用浸渍还原法得到Ag/MIL-101(Cr)-NH_(2)催化剂。通过XRD、N_(2)-吸附脱附曲线和TEM手段对催化剂进行表征。研究了Ag/MIL-101(Cr)-NH_(2)催化4-硝基苯酚(4-NP)加氢生... 通过水热法制备出MIL-101(Cr)-NH_(2),以MIL-101(Cr)-NH_(2)为载体采用浸渍还原法得到Ag/MIL-101(Cr)-NH_(2)催化剂。通过XRD、N_(2)-吸附脱附曲线和TEM手段对催化剂进行表征。研究了Ag/MIL-101(Cr)-NH_(2)催化4-硝基苯酚(4-NP)加氢生成4-氨基苯酚(4-AP)的性能。结果表明,3wt%Ag/MIL-101(Cr)-NH_(2)样品的催化加氢性能高于其它样品,仅用4 min可将4-NP催化加氢全部转化为4-AP。因此Ag/MIL-101(Cr)-NH_(2)催化剂具有较好的催化4-NP加氢性能。 展开更多
关键词 MiL-101(Cr)-NH_(2) ag纳米粒子 4-硝基苯酚 催化加氢
下载PDF
(Ag,Cu)/TiO_(2)汽车玻璃隔热膜的制备与表征
4
作者 王宁 时方晓 《广州化工》 CAS 2024年第7期69-72,共4页
利用磁控溅射技术制备由金属(Ag,Cu)膜、介质层TiO_(2)膜组成的双层汽车玻璃隔热膜样品。利用单因素分析法考察了溅射时间、溅射功率和Ar溅射流量三个因素对(Ag,Cu)/TiO_(2)汽车玻璃隔热膜透光隔热性能的影响。实验结果表明,在在本底真... 利用磁控溅射技术制备由金属(Ag,Cu)膜、介质层TiO_(2)膜组成的双层汽车玻璃隔热膜样品。利用单因素分析法考察了溅射时间、溅射功率和Ar溅射流量三个因素对(Ag,Cu)/TiO_(2)汽车玻璃隔热膜透光隔热性能的影响。实验结果表明,在在本底真空度3×10^(-3) Pa,溅射气压2.1 Pa条件下,靶基距均为70 mm时,金属(Ag,Cu)膜溅射时间18 s,溅射功率80 W,Ar溅射流量20 sccm;介质层TiO_(2)膜溅射时间50 min,溅射功率115 W,溅射流量25 sccm时,(Ag,Cu)/TiO_(2)汽车玻璃隔热膜的透光隔热性能最佳。 展开更多
关键词 (ag Cu)/TiO_(2)膜 汽车玻璃 隔热性能 透光率
下载PDF
UE参数、S-TK1、AG490、WIP1诊断TC
5
作者 施小燕 田颖颖 《现代科学仪器》 2024年第2期108-112,共5页
目的:探究UE参数、S-TK1、AG490、WIP1对甲状腺癌(TC)的诊断价值。方法:选择我院收治TC患者102例(TC组)和同期收治甲状腺结节良性患者73例(对照组)。比较两组UE参数、S-TK1、AG490、WIP1,分析各指标对TC的诊断价值。结果:TC组的弹性评分... 目的:探究UE参数、S-TK1、AG490、WIP1对甲状腺癌(TC)的诊断价值。方法:选择我院收治TC患者102例(TC组)和同期收治甲状腺结节良性患者73例(对照组)。比较两组UE参数、S-TK1、AG490、WIP1,分析各指标对TC的诊断价值。结果:TC组的弹性评分、SR值、S-TK1、WIP1水平均高于对照组,AG490低于对照组(P<0.05);ROC曲线分析发现五项指标联合诊断TC的AUC最高(P<0.05)。结论:UE参数与S-TK1、WIP1、AG490联合检测有利于临床诊断TC。 展开更多
关键词 甲状腺癌 超声弹性成像 血清胸苷激酶1 ag490 野生型p53诱导的磷酸酶1
下载PDF
EGFR抑制剂AG1478联合奥沙利铂抑制PI3K/AKT通路促进H1975细胞自噬的作用机制 被引量:1
6
作者 黄金清 李洋 +2 位作者 韦东雪 江山 江绍锋 《中国药理学通报》 CAS CSCD 北大核心 2024年第2期272-278,共7页
目的探究奥沙利铂(oxaliplatin,OXA)联合表皮生长因子受体酪氨酸激酶抑制剂AG1478对非小细胞肺癌(non-small cell lung cancer,NSCLC)H1975细胞自噬的作用。方法采用梯度浓度的AG1478(0、5、10、15、20、25、30、35、40μmol·L^(-... 目的探究奥沙利铂(oxaliplatin,OXA)联合表皮生长因子受体酪氨酸激酶抑制剂AG1478对非小细胞肺癌(non-small cell lung cancer,NSCLC)H1975细胞自噬的作用。方法采用梯度浓度的AG1478(0、5、10、15、20、25、30、35、40μmol·L^(-1))和OXA(0、25、50、75、88、100、112、125、150μmol·L^(-1))体外培养H1975细胞,MTT法检测AG1478和OXA对H1975细胞活力的影响,MDC法检测H1975细胞自噬水平,Western blot法检测PI3K/AKT信号通路(PI3K、p-PI3K、AKT、p-AKT)以及自噬相关蛋白(Beclin^(-1)、LC3Ⅱ)的表达水平;ROS探针H2DCFDA检测H1975细胞的ROS水平。结果MTT结果显示,OXA作用于H1975细胞的半数抑制浓度IC 50为70.86μmol·L^(-1);AG1478作用于H1975细胞的IC 50为24.24μmol·L^(-1);MDC实验结果显示,与对照组比较,(OXA-25、OXA-50、OXA^(-1)00)OXA单药组、AG1478单药组及联合用药组自噬水平明显升高;与OXA单药组(OXA-25)比较,联合用药组自噬水平升高;Western blot检测结果显示,与对照组比较,(OXA-25、OXA-50、OXA^(-1)00)OXA单药组、AG1478单药组及联合用药组PI3K、p-PI3K、AKT、p-AKT蛋白表达均下调,应用N-乙酰半胱胺酸(N-acetylcysteine,NAC)预处理后,联合用药组PI3K、p-PI3K、AKT、p-AKT下调水平被抑制;与OXA单药组(OXA-25)比较,联合用药组PI3K、p-PI3K、AKT、p-AKT的蛋白表达水平均下降;Western blot检测结果显示,与对照组比较,(OXA-25、OXA-50、OXA^(-1)00)OXA单药组、AG1478单药组及联合用药组Beclin^(-1)、LC3Ⅱ的蛋白表达上调,应用NAC预处理后,联合用药组Beclin^(-1)、LC3Ⅱ的蛋白表达被抑制,应用PI3K抑制剂(LY294002)预处理后,联合用药组Beclin^(-1)、LC3Ⅱ的蛋白表达明显上调;与OXA单药组(OXA-25)比较,联合用药组Beclin^(-1)、LC3Ⅱ的蛋白表达水平升高;H2DCFDA检测发现,与对照组比较,(OXA-25、OXA-50、OXA^(-1)00)OXA单药组、AG1478单药组及联合用药组ROS水平升高;与对照组比较,联合用药组ROS水平明显升高,NAC处理组ROS水平明显降低;与联合用药组相比较,NAC预处理的联合用药组ROS水平下降。结论AG1478联合OXA诱导NSCLC H1975细胞调控ROS水平升高,抑制PI3K信号通路的激活,进而促进H1975细胞自噬。 展开更多
关键词 非小细胞肺癌 ag1478 奥沙利铂 ROS 自噬 Pi3K/AKT信号通路
下载PDF
具有增强光催化和抗菌活性的TiO_(2)@Ag-GO复合材料 被引量:1
7
作者 戴胜 刘鲁英 +1 位作者 王致钘 杨苹 《中国表面工程》 EI CAS CSCD 北大核心 2024年第1期118-125,共8页
光催化降解环境中的污染物被认为一种理想的清洁方法,其中二氧化钛(TiO_(2))是目前最有前途的光催化材料之一。但由于能带宽、光生电子与空穴快速复合等特点,限制了其利用效率和范围,开发一种高效的TiO_(2)基光催化复合材料具有重要意... 光催化降解环境中的污染物被认为一种理想的清洁方法,其中二氧化钛(TiO_(2))是目前最有前途的光催化材料之一。但由于能带宽、光生电子与空穴快速复合等特点,限制了其利用效率和范围,开发一种高效的TiO_(2)基光催化复合材料具有重要意义。通过简单的溶胶-凝胶法和一步Marangoni法,将TiO_(2)和Ag纳米颗粒(AgNPs)和氧化石墨烯(GO)有效结合,制备出显著增强光催化活性和抗菌能力的复合材料TiO_(2)@Ag-GO。氧化石墨烯(GO)具有多个催化活性中心,可以高效地进行光催化反应降解污染物。同时,还能提高电荷分离程度,抑制光生电子和空穴复合,提高TiO_(2)光催化活性。AgNPs具有存储电子和促进电荷分离的能力,同时释放的Ag+,赋予材料广谱的抗菌性能。光催化试验抑菌试验结果表明,复合材料能高效降解亚甲基蓝染料,2 h降解率达到74.5%,同时对金黄色葡萄球菌和铜绿杆菌有较强的杀灭作用。这种简易制备的高催化和杀菌功能的TiO_(2)基复合材料在光催化清洁领域有很大的应用潜力。 展开更多
关键词 二氧化钛(TiO_(2)) ag纳米颗粒(agNPs) 氧化石墨烯(GO) 光催化活性 抗菌性能
下载PDF
氨基水杨酸改性单宁基树脂的制备及其对Ag(I)的吸附
8
作者 李佳玲 黄钱兰 +1 位作者 章爱华 彭志远 《吉首大学学报(自然科学版)》 CAS 2024年第1期42-47,96,共7页
以杨梅单宁为原料,采用氯代的方法制备得到氯化单宁,再与氨基水杨酸反应得到氨基水杨酸改性单宁,然后经多聚甲醛交联得到氨基水杨酸改性单宁基树脂.采用傅里叶变换红外光谱仪对氨基水杨酸改性单宁基树脂的结构进行表征,并探究了溶液pH值... 以杨梅单宁为原料,采用氯代的方法制备得到氯化单宁,再与氨基水杨酸反应得到氨基水杨酸改性单宁,然后经多聚甲醛交联得到氨基水杨酸改性单宁基树脂.采用傅里叶变换红外光谱仪对氨基水杨酸改性单宁基树脂的结构进行表征,并探究了溶液pH值、Ag(I)初始质量浓度、温度、时间等因素对氨基水杨酸改性单宁基树脂吸附性能的影响.结果表明,在温度为318 K、pH值为5.0、吸附时间为7 h、Ag(I)初始质量浓度为260 mg/L时,氨基水杨酸改性单宁基树脂对Ag(I)的最大吸附量可达239.6 mg/g,吸附过程符合Langmuir吸附等温模型和准二级动力学模型.这说明氨基水杨酸改性单宁基树脂具有良好Ag(I)吸附性能. 展开更多
关键词 氨基水杨酸改性单宁基树脂 吸附性能 ag(i)吸附
下载PDF
Ag掺杂In_(2)O_(3)薄膜的制备及其光电性能
9
作者 韩梦瑶 孙辉 +3 位作者 周鸥翔 齐东丽 李同辉 沈龙海 《吉林大学学报(理学版)》 CAS 北大核心 2024年第4期985-991,共7页
为研究Ag的掺杂浓度对氧化铟薄膜禁带宽度、光开关比及光探测率等光电性能的影响,采用磁控溅射方法在石英(SiO_(2))衬底上制备不同浓度的Ag掺杂氧化铟(In_(2)O_(3)∶Ag)薄膜,并利用X射线衍射、 X射线光电子能谱、扫描电子显微镜、紫外-... 为研究Ag的掺杂浓度对氧化铟薄膜禁带宽度、光开关比及光探测率等光电性能的影响,采用磁控溅射方法在石英(SiO_(2))衬底上制备不同浓度的Ag掺杂氧化铟(In_(2)O_(3)∶Ag)薄膜,并利用X射线衍射、 X射线光电子能谱、扫描电子显微镜、紫外-可见分光光度计分析In_(2)O_(3)∶Ag薄膜的晶体结构、元素含量和价态、表面形貌、禁带宽度及光电性能.结果表明:随着Ag掺杂浓度的增加,In_(2)O_(3)∶Ag薄膜的透过率逐渐降低,禁带宽度由2.47 eV减小至2.08 eV,光探测率和光开关比增大;随着掺杂浓度的增加,光谱响应范围增加. 展开更多
关键词 氧化铟 ag掺杂 磁控溅射 禁带宽度 光电性能
下载PDF
Microglial response to aging and neuroinflammation in the development of neurodegenerative diseases 被引量:3
10
作者 Tingting Han Yuxiang Xu +2 位作者 Lin Sun Makoto Hashimoto Jianshe Wei 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第6期1241-1248,共8页
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.Review... 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. 展开更多
关键词 agiNG Alzheimer's disease cytokines Huntington's disease MiCROGLiA neurodegenerative diseases NEUROiNFLAMMATiON NEUROPROTECTiON NEUROTOXiCiTY Parkinson's disease
下载PDF
The burden of depression,anxiety and schizophrenia among the older population in ageing and aged countries:an analysis of the Global Burden of Disease Study 2019 被引量:2
11
作者 Ying Cheng Yu Fang +3 位作者 Jinxin Zheng shiyang Guan Meiti Wang Wu Hong 《General Psychiatry》 CSCD 2024年第1期83-93,共11页
Background Depression,anxiety and schizophrenia among older persons have become global public health challenges.However,the burden of these disorders in ageing and aged countries has not been analysed.Aims To investig... Background Depression,anxiety and schizophrenia among older persons have become global public health challenges.However,the burden of these disorders in ageing and aged countries has not been analysed.Aims To investigate the burden of depression,anxiety and schizophrenia among older adults in ageing and aged countries.Methods Using data from the Global Burden of Disease Study 2019,we calculated the estimated annual percentage change(EAPC)in the age-standardised incidence rates(ASiR)and age-standardised disability-adjusted life years(DALYs)rates(ASDR)for depression,anxiety and schizophrenia of older people in ageing countries(China,India,Indonesia)and aged countries(Japan,Italy,Portugal)between 1990 and 2019.Trends in incidence and DALYs were analysed by gender and age.Results In 2019,the highest incidence of depression,anxiety and schizophrenia in the older population in aged countries was in Japan(927271.3(752552.3-1125796.5),51498.2(37625.7-70487.3)and 126.0(61.0-223.2),respectively),while the highest incidence in ageing countries was in China(5797556.9(4599403.4-7133006.5),330256.1(246448.9-445987.4)and 1067.7(556.2-1775.9),respectively).DALYs for these disorders were similar,with the highest in Japan and China.From 1990 to 2019,the ASIR for depressive disorders decreased in aged countries but increased in ageing countries;the ASIR for anxiety disorders and schizophrenia declined in both ageing and aged countries.The ASDR for depressive disorders was consistent with the ASIR but not for anxiety disorders and schizophrenia.The ASIR for depressive disorders was higher in older women,while the opposite was observed in anxiety disorders and schizophrenia.Notably,the conditions of burden of depressive disorders,anxiety disorders and schizophrenia in the 65-70-year-old age group were the most burdensome.Conclusions The incidence and DALYs of these three mental disorders increased while exhibiting differences between ageing and aged countries.Raising awareness about formulating health policies for preventing and treating mental disorders in the older population is necessary to reduce the future burden posed by the ageing challenge. 展开更多
关键词 SCHiZOPHRENiA BURDEN ageing
下载PDF
Te含量对Ag/SnO_(2)In_(2)O_(3)电接触材料组织及电接触性能的影响
12
作者 尹恒虎 聂宝鑫 +3 位作者 周细应 张国全 王塞北 顾文秀 《材料热处理学报》 CAS CSCD 北大核心 2024年第1期42-52,共11页
采用合金内氧化法制备了不同Te含量的Ag/SnO_(2)In_(2)O_(3)电接触材料,利用X射线衍射(XRD)、X射线光电子能谱(XPS)和光学显微镜(OM)分析了Ag/SnO_(2)In_(2)O_(3)微观组织,利用JF04C触点测试系统测试了铆钉型触点的电接触性能,分析了Ag/... 采用合金内氧化法制备了不同Te含量的Ag/SnO_(2)In_(2)O_(3)电接触材料,利用X射线衍射(XRD)、X射线光电子能谱(XPS)和光学显微镜(OM)分析了Ag/SnO_(2)In_(2)O_(3)微观组织,利用JF04C触点测试系统测试了铆钉型触点的电接触性能,分析了Ag/SnO_(2)In_(2)O_(3)电接触材料的转移损耗情况,并利用扫描电镜(SEM)对电接触材料动静触点电弧侵蚀形貌进行了分析,分析Te的添加对材料性能和燃弧机制的影响。结果表明:Te的添加有助于细化晶粒,并且随着Te含量增加,Ag/SnO_(2)In_(2)O_(3)材料形成了波浪状组织,Te的加入未对Ag、SnO_(2)和In_(2)O_(3)的存在形式造成影响,材料的相组成包括Ag、SnO_(2)、In_(2)O_(3)、TeO_(2)和单质Te。随着Te含量增加,材料的接触电阻呈现先上升后下降再上升的趋势,当Te的添加量为0.75%时,接触电阻最低且最稳定,熔焊力平均值为26.6 cN,低于常规模拟继电器30.6 cN的分断力。Te的添加改变了材料转移模式,减少了电弧侵蚀表面喷溅状侵蚀形貌的出现,当Te的添加量为0.75%时,电弧侵蚀表面产生的“猪网油”状的网状结构和“桑葚”状结构,对Ag/SnO_(2)In_(2)O_(3)材料在持续高频直流场合抗材料定向转移及抗熔焊性能方面改善显著,过量添加则会恶化触点性能。 展开更多
关键词 ag/SnO_(2)in_(2)O_(3) 碲元素 电接触性能 电弧侵蚀 网状结构
下载PDF
Effects of Maillard reaction and its product AGEs on aging and age-related diseases 被引量:1
13
作者 Huan Peng Yuqi Gao +4 位作者 Chenye Zeng Rui Hua Yannan Guo Yida Wang Zhao Wang 《Food Science and Human Wellness》 SCIE CSCD 2024年第3期1118-1134,共17页
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 pro... 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. 展开更多
关键词 Maillard reaction Advanced glycation end products Physiologic aging Pathological aging Drug intervention
下载PDF
How do neurons age?A focused review on the aging of the microtubular cytoskeleton 被引量:1
14
作者 Brad Richardson Thomas Goedert +2 位作者 Shmma Quraishe Katrin Deinhardt Amritpal Mudher 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第9期1899-1907,共9页
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 t... 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. 展开更多
关键词 age-related changes agiNG CYTOSKELETON MiCROTUBULES neuronal morphology
下载PDF
Single-cell transcriptomic atlas of goat ovarian aging 被引量:1
15
作者 Dejun Xu Shuaifei Song +5 位作者 Fuguo Wang Yawen Li Ziyuan Li Hui Yao Yongju Zhao Zhongquan Zhao 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2024年第1期146-161,共16页
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 a... 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. 展开更多
关键词 GOAT Granulosa cells Ovarian aging Single-cell transcriptomic
下载PDF
Ag/ZIF-8复合材料的制备及其光降解性能
16
作者 乔丹妮 徐洁 李东祥 《青岛科技大学学报(自然科学版)》 CAS 2024年第2期29-37,共9页
在无表面活性剂微乳液中制备了ZIF-8材料,并采用光致还原法将纳米Ag负载于ZIF-8表面,制备了负载量不同的系列Ag/ZIF-8复合材料。XRD、SEM、XPS、UV-DRS以及光电性能测试表明Ag成功负载到ZIF-8中,且光电性能大幅度提高。对比考察了ZIF-8... 在无表面活性剂微乳液中制备了ZIF-8材料,并采用光致还原法将纳米Ag负载于ZIF-8表面,制备了负载量不同的系列Ag/ZIF-8复合材料。XRD、SEM、XPS、UV-DRS以及光电性能测试表明Ag成功负载到ZIF-8中,且光电性能大幅度提高。对比考察了ZIF-8和Ag/ZIF-8对有机染料的光降解效率,提出了光催化机理。由于Ag纳米粒子和ZIF-8的协同效应,其所形成的异质结构Ag/ZIF-8表现出了优异的光催化活性。 展开更多
关键词 ag/ZiF-8复合材料 无表面活性剂微乳液 光降解
下载PDF
Hypothalamic circuits and aging:keeping the circadian clock updated 被引量:1
17
作者 Rosa Vázquez-Lizarraga Lucia Mendoza-Viveros +3 位作者 Carolina Cid-Castro Sareni Ruiz-Montoya Erick Carreño-Vázquez Ricardo Orozco-Solis 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第9期1919-1928,共10页
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 un... 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. 展开更多
关键词 agiNG ASTROCYTES cellular stress responses circadian clock HYPOTHALAMUS intranasal drug administration metabolic control nutrient sensor SiRT1 sleep homeostasis
下载PDF
Activation of cerebral Ras-related C3 botulinum toxin substrate(Rac) 1 promotes post-ischemic stroke functional recovery in aged mice 被引量:1
18
作者 Fan Bu Jia-Wei Min +5 位作者 Md Abdur Razzaque Ahmad El Hamamy Anthony Patrizz Li Qi Akihiko Urayama Jun Li 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第4期881-886,共6页
Brain functional impairment after stroke is common;however,the molecular mechanisms of post-stroke recovery remain unclear.It is well-recognized that age is the most important independent predictor of poor outcomes af... Brain functional impairment after stroke is common;however,the molecular mechanisms of post-stroke recovery remain unclear.It is well-recognized that age is the most important independent predictor of poor outcomes after stroke as older patients show poorer functional outcomes following stroke.Mounting evidence suggests that axonal regeneration and angiogenesis,the major forms of brain plasticity responsible for post-stroke recovery,diminished with advanced age.Previous studies suggest that Ras-related C3 botulinum toxin substrate(Rac)1 enhances stroke recovery as activation of Rac1 improved behavior recovery in a young mice stroke model.Here,we investigated the role of Rac1 signaling in long-term functional recovery and brain plasticity in an aged(male,18 to 22 months old C57BL/6J)brain after ischemic stroke.We found that as mice aged,Rac1 expression declined in the brain.Delayed overexpression of Rac1,using lentivirus encoding Rac1 injected day 1 after ischemic stroke,promoted cognitive(assessed using novel object recognition test)and sensorimotor(assessed using adhesive removal tests)recovery on days 14–28.This was accompanied by the increase of neurite and proliferative endothelial cells in the periinfarct zone assessed by immunostaining.In a reverse approach,pharmacological inhibition of Rac1 by intraperitoneal injection of Rac1 inhibitor NSC23766 for 14 successive days after ischemic stroke worsened the outcome with the reduction of neurite and proliferative endothelial cells.Furthermore,Rac1 inhibition reduced the activation of p21-activated kinase 1,the protein level of brain-derived neurotrophic factor,and increased the protein level of glial fibrillary acidic protein in the ischemic brain on day 28 after stroke.Our work provided insight into the mechanisms behind the diminished plasticity after cerebral ischemia in aged brains and identified Rac1 as a potential therapeutic target for improving functional recovery in the older adults after stroke. 展开更多
关键词 aging angiogenesis brain-derived neurotrophic factor(BDNF) cerebral ischemia cognitive recovery NEURiTE PAK1 RAC1 sensorimotor recovery
下载PDF
Mechanistic investigation on Ag-Cu_(2)O in electrocatalytic CO_(2) to CH_(4) by in situ/operando spectroscopic and theoretical analysis 被引量:1
19
作者 Min Sun Luxiao Zhang +10 位作者 Fuli Tian Jiaxin Li Yanqiu Lei Heng Zhang Lifeng Han Zhihua Guo Yonghui Gao Fenrong Liu Yan Wang Luhui Wang Shanghong Zeng 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第1期521-531,I0012,共12页
Silver-copper electrocatalysts have demonstrated effectively catalytic performance in electroreduction CO_(2) toward CH_(4),yet a revealing insight into the reaction pathway and mechanism has remained elusive.Herein,w... Silver-copper electrocatalysts have demonstrated effectively catalytic performance in electroreduction CO_(2) toward CH_(4),yet a revealing insight into the reaction pathway and mechanism has remained elusive.Herein,we construct chemically bonded Ag-Cu_(2)O boundaries,in which the complete reduction of Cu_(2)O to Cu has been strongly impeded owing to the presence of surface Ag shell.The interfacial confinement effect helps to maintain Cu^(+)sites at the Ag-Cu_(2)O boundaries.Using in situ/operando spectroscopy and theoretical simulations,it is revealed that CO_(2) is enriched at the Ag-Cu_(2)O boundaries due to the enhanced physisorption and chemisorption to CO_(2),activating CO_(2) to form the stable intermediate^(*)CO.The boundaries between Ag shell and the Cu_(2)O mediate local^(*)CO coverage and promote^(*)CHO intermediate formation,consequently facilitating CO_(2)-to-CH_(4) conversion.This work not only reveals the structure-activity relationships but also offers insights into the reaction mechanism on Ag-Cu catalysts for efficient electrocatalytic CO_(2) reduction. 展开更多
关键词 ag shell interfacial confinement effect Cu~+ Local*CO coverage CO_(2)reduction
下载PDF
利用Ti/Ag中间层实现金刚石与GaN的室温键合
20
作者 乔冠中 李淑同 +4 位作者 王越 刘金龙 陈良贤 魏俊俊 李成明 《表面技术》 EI CAS CSCD 北大核心 2024年第18期175-182,共8页
目的为了实现金刚石与GaN的良好键合,利用Ti/Ag中间层,在室温下开展了多晶金刚石与GaN的键合技术研究。方法首先,分别在抛光自支撑多晶金刚石晶圆以及GaN晶圆表面,通过磁控溅射依次沉积Ti黏附层、Ti/Ag梯度层以及纳米Ag层,形成Ti/Ag过... 目的为了实现金刚石与GaN的良好键合,利用Ti/Ag中间层,在室温下开展了多晶金刚石与GaN的键合技术研究。方法首先,分别在抛光自支撑多晶金刚石晶圆以及GaN晶圆表面,通过磁控溅射依次沉积Ti黏附层、Ti/Ag梯度层以及纳米Ag层,形成Ti/Ag过渡层复合结构。然后通过真空键合系统成功实现了金刚石与Ga N键合。通过扫描电子显微镜(SEM)、原子力显微镜(AFM)、X射线衍射(XRD)以及X射线光电子能谱(XPS)等表征手段,对键合前后样品表面进行形貌及结构分析;通过超声扫描显微镜(SAM),以及拉伸力学测试系统,对键合后的键合率以及键合强度进行评价。结果借助Ti/Ag中间层进行键合,对晶圆表面的粗糙度具有较高容忍度,且在常温下即能实现良好键合,室温键合率达到95.5%。通过拉伸强度测试可知,键合强度达到13.7MPa。结论Ag纳米颗粒高的表面活性是实现键合界面常温融合的关键,而Ti底层良好的附着特性,Ti/Ag梯度层的引入以及Ti与Ag之间通过扩散反应形成的金属间化合物,则是提高金刚石与GaN键合强度的关键因素。 展开更多
关键词 金刚石 氮化镓 Ti/ag中间层 室温键合 金属间化合物
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部