Graphene nanoplatelets(GNPs)have attracted tremendous interest due to their unique properties and bonding capabilities.This study focuses on the effect of GNP dispersion on the mechanical,thermal,and morphological beh...Graphene nanoplatelets(GNPs)have attracted tremendous interest due to their unique properties and bonding capabilities.This study focuses on the effect of GNP dispersion on the mechanical,thermal,and morphological behavior of GNP/epoxy nanocomposites.This study aims to understand how the dispersion of GNPs affects the properties of epoxy nanocomposite and to identify the best dispersion approach for improving mechanical performance.A solvent mixing technique that includes mechanical stirring and ultrasonication was used for producing the nanocomposites.Fourier transform infrared spectroscopy was used to investigate the interaction between GNPs and the epoxy matrix.The measurements of density and moisture content were used to confirm that GNPs were successfully incorporated into the nanocomposite.The findings showed that GNPs are successfully dispersed in the epoxy matrix by combining mechanical stirring and ultrasonication in a single step,producing well-dispersed nanocomposites with improved mechanical properties.Particularly,the nanocomposites at a low GNP loading of 0.1 wt%,demonstrate superior mechanical strength,as shown by increased tensile properties,including improved Young's modulus(1.86 GPa),strength(57.31 MPa),and elongation at break(4.98).The nanocomposite with 0.25 wt%GNP loading performs better,according to the viscoelastic analysis and flexural properties(113.18 MPa).Except for the nanocomposite with a 0.5 wt%GNP loading,which has a higher thermal breakdown temperature,the thermal characteristics do not significantly alter.The effective dispersion of GNPs in the epoxy matrix and low agglomeration is confirmed by the morphological characterization.The findings help with filler selection and identifying the best dispersion approach,which improves mechanical performance.The effective integration of GNPs and their interaction with the epoxy matrix provides the doorway for additional investigation and the development of sophisticated nanocomposites.In fields like aerospace,automotive,and electronics where higher mechanical performance and functionality are required,GNPs'improved mechanical properties and successful dispersion present exciting potential.展开更多
目的:研究大鼠胃癌前病变形成过程中胃黏膜Sonic Hedgehog(Shh)信号通路的变化。方法:72只乳鼠随机分为正常组36只,造模组36只,雌雄各半。造模组灌服800 mg/L的1-甲基-3-硝基-1-亚硝基胍(MNNG)0.1 m L/d,正常组灌服生理盐水0.1 m L/d,共...目的:研究大鼠胃癌前病变形成过程中胃黏膜Sonic Hedgehog(Shh)信号通路的变化。方法:72只乳鼠随机分为正常组36只,造模组36只,雌雄各半。造模组灌服800 mg/L的1-甲基-3-硝基-1-亚硝基胍(MNNG)0.1 m L/d,正常组灌服生理盐水0.1 m L/d,共10 d。随后在实验观察第10周、22周、34周末每组分别雌雄各处死6只。HE染色检测胃黏膜组织病理学变化,q RTPCR法检测胃黏膜组织Shh、Ptch1、Smo、Gli1、Gli2、Gli3、Su Fu、Cyclin D1、Cyclin E1、c-Myc、β-actin m RNA的表达。Western blot检测胃黏膜组织Shh、Ptch1、Smo、Gli1、Su Fu、Cyclin D1、Cyclin E1、cMyc、p-c-Myc蛋白表达。结果:随造模时间的延长,模型组大鼠胃黏膜萎缩及异型增生逐渐加重,其胃黏膜内Shh、Smo、Gli1、Cyclin D1、Cyclin E1及c-Myc m RNA表达较正常组不同程度升高,而Ptch1和Su Fu m RNA不同程度降低。模型组胃黏膜内Shh、Smo、Gli1、Cyclin D1、Cyclin E1、p-c-Myc蛋白水平较正常组增加,Ptch1和Su Fu则降低,但差异无统计学意义。结论:大鼠胃癌前病变的形成过程中存在Shh信号通路的激活,提示Shh信号通路可能参与胃癌前病变的发生与发展。展开更多
Sonic hedgehog(Shh)信号转导通路是脊椎动物hedgehog信号通路家族成员之一,主要由分泌型糖蛋白Shh配体、跨膜蛋白受体Ptch和Smo以及下游转录因子Gli蛋白组成,在胚胎发育尤其是神经系统发育中起着重要的作用。近年研究发现Shh信号通路...Sonic hedgehog(Shh)信号转导通路是脊椎动物hedgehog信号通路家族成员之一,主要由分泌型糖蛋白Shh配体、跨膜蛋白受体Ptch和Smo以及下游转录因子Gli蛋白组成,在胚胎发育尤其是神经系统发育中起着重要的作用。近年研究发现Shh信号通路与多种肿瘤的形成有着密切的关系。神经胶质瘤是最常见的原发性脑肿瘤,生长迅速且多呈浸润性,易复发,是脑肿瘤中治疗效果最差的肿瘤之一,主要原因是多种信号通路的异常激活增强了胶质瘤细胞的增殖能力。此外,神经胶质瘤是由不同属性的肿瘤细胞混合构成,胶质瘤中的肿瘤干细胞具有无限增殖能力,这一特性也对胶质瘤的发生、发展和复发起着重要作用。有研究发现Shh信号通路与神经胶质瘤的发生、增殖及胶质瘤干细胞有密切关系。本文主要就Shh信号通路的组成和其在神经胶质瘤发生及胶质瘤干细胞中的相关作用作一综述。展开更多
基金the Puncak RM for the project under the grant 6733204-13069 to carry out the experiments。
文摘Graphene nanoplatelets(GNPs)have attracted tremendous interest due to their unique properties and bonding capabilities.This study focuses on the effect of GNP dispersion on the mechanical,thermal,and morphological behavior of GNP/epoxy nanocomposites.This study aims to understand how the dispersion of GNPs affects the properties of epoxy nanocomposite and to identify the best dispersion approach for improving mechanical performance.A solvent mixing technique that includes mechanical stirring and ultrasonication was used for producing the nanocomposites.Fourier transform infrared spectroscopy was used to investigate the interaction between GNPs and the epoxy matrix.The measurements of density and moisture content were used to confirm that GNPs were successfully incorporated into the nanocomposite.The findings showed that GNPs are successfully dispersed in the epoxy matrix by combining mechanical stirring and ultrasonication in a single step,producing well-dispersed nanocomposites with improved mechanical properties.Particularly,the nanocomposites at a low GNP loading of 0.1 wt%,demonstrate superior mechanical strength,as shown by increased tensile properties,including improved Young's modulus(1.86 GPa),strength(57.31 MPa),and elongation at break(4.98).The nanocomposite with 0.25 wt%GNP loading performs better,according to the viscoelastic analysis and flexural properties(113.18 MPa).Except for the nanocomposite with a 0.5 wt%GNP loading,which has a higher thermal breakdown temperature,the thermal characteristics do not significantly alter.The effective dispersion of GNPs in the epoxy matrix and low agglomeration is confirmed by the morphological characterization.The findings help with filler selection and identifying the best dispersion approach,which improves mechanical performance.The effective integration of GNPs and their interaction with the epoxy matrix provides the doorway for additional investigation and the development of sophisticated nanocomposites.In fields like aerospace,automotive,and electronics where higher mechanical performance and functionality are required,GNPs'improved mechanical properties and successful dispersion present exciting potential.
文摘目的:研究大鼠胃癌前病变形成过程中胃黏膜Sonic Hedgehog(Shh)信号通路的变化。方法:72只乳鼠随机分为正常组36只,造模组36只,雌雄各半。造模组灌服800 mg/L的1-甲基-3-硝基-1-亚硝基胍(MNNG)0.1 m L/d,正常组灌服生理盐水0.1 m L/d,共10 d。随后在实验观察第10周、22周、34周末每组分别雌雄各处死6只。HE染色检测胃黏膜组织病理学变化,q RTPCR法检测胃黏膜组织Shh、Ptch1、Smo、Gli1、Gli2、Gli3、Su Fu、Cyclin D1、Cyclin E1、c-Myc、β-actin m RNA的表达。Western blot检测胃黏膜组织Shh、Ptch1、Smo、Gli1、Su Fu、Cyclin D1、Cyclin E1、cMyc、p-c-Myc蛋白表达。结果:随造模时间的延长,模型组大鼠胃黏膜萎缩及异型增生逐渐加重,其胃黏膜内Shh、Smo、Gli1、Cyclin D1、Cyclin E1及c-Myc m RNA表达较正常组不同程度升高,而Ptch1和Su Fu m RNA不同程度降低。模型组胃黏膜内Shh、Smo、Gli1、Cyclin D1、Cyclin E1、p-c-Myc蛋白水平较正常组增加,Ptch1和Su Fu则降低,但差异无统计学意义。结论:大鼠胃癌前病变的形成过程中存在Shh信号通路的激活,提示Shh信号通路可能参与胃癌前病变的发生与发展。
