Expression profile of voltage-gated potassium channel Kv1.3 in aorta of atherosclerosis rats

目的探讨动脉粥样硬化(AS)大鼠主动脉病变局部离子通道kV1.3的表达水平及作用。方法雄性WISTAr大鼠16只,随机分为两组:正常组(8只,予普通饮食+0.9%氯化钠溶液)和AS组(8只,予高脂饮食+维生素d3负荷)。采用组织病理学检查,观察主动脉粥样硬化病变。采用实时定量反转录-聚合酶链反应(rT-PCr)和WESTErn印迹法检测主动脉病变局部kV1.3和白细胞介素(Il)-2、干扰素(Ifn)-γ的表达水平。结果组织病理学检查证实纤维增生性AS斑块。AS组的kV1.3MrnA为(31.48±8.64)x10-3,显著高于正常组的(3.28±0.79)x10-3(P=0.012)。AS组的kV1.3、Il-2、Ifn-γ蛋白表达量分别为0.691±0.067、0.611±0.055、0.759±0.050,均显著高于正常组的0.490±0.052、0.299±0.058、0.273±0.052(P值均<0.01)。结论 kV1.3在主动脉粥样硬化病变局部的表达增高。kV1.3可能在AS的发生和发展过程中发挥着重要的作用。Objective To investigate the expression of voltage-gated potassium channel Kv1.3 in the aorta of a rat model of atherosclerosis and its role in the progress of atherosclerotic plaque formation.Methods A total of 16 male Wistar rats were randomly divided into normal control(normal diet and saline)and atherosclerosis group(high lipid diet+Vitamin D3 overload),with 8 rats in each group.In 16 weeks later,all rats were killed after weighing,and their blood samples and aorta were collected.Pathological changes of the rat aortic artery were observed with HE staining.Real time RT-PCR and Western blotting analysis were used to determine the mRNA and protein expression of Kv1.3 and the protein expressions of interleukin(IL)-2 and interfereron(IFN)-γ.Results Pathological changes showed that fiber proliferative atherosclerotic plaques were found in the aorta of atherosclerosis group,with inflammatory cells infiltrating in the local lesion.Real time RT-PCR analysis showed that the expression of Kv1.3 mRNA in the aorta was increased significantly in the atherosclerosis rats than that in the controls([31.48±8.64]×10-3 vs.[3.28±0.79]×10-3,P<0.05).Western blotting analysis showed that the protein expression of Kv1.3,IL-2 and IFN-γ in the aorta were also increased significantly in the atherosclerotic rats than that in the controls(Kv1.3[0.691±0.067] vs.[0.490±0.052],IL-2 [0.611±0.055] vs.[0.299±0.058],IFN-γ [0.759±0.050] vs.[0.273±0.052],P<0.01 n=8).Conclusion The expression of Kv1.3 potassium channels is increased in the plaques of atherosclerotic rats.Kv1.3 may play an important role in the development and progression of atherosclerosis.国家自然科学基金资助项目(30871045

Dynamics Analysis of Surface Layer Thickness Growth of Hot Dip RE-Al Coating under Ultrasonic Vibration Field

用溶剂法制备了稀土铝镀层,采用金相显微镜、扫描电镜观察测定了超声场对热浸镀稀土铝表面层厚度的影响,绘制了表面层厚度变化的动力学曲线.研究得知,稀土铝镀层由表面层和过渡层组成.通过厚度测定发现,过渡层厚度遵循抛物线生长规律,而表面层的厚度变化则明显不同.随着热浸稀土铝时间的延长,表面层厚度经历了先减少至谷值,然后增加到峰值,又减少至稳定值的3个阶段.每一阶段控制厚度变化的因素不同,将其变化过程分为由凝固-重熔控制的第Ⅰ阶段,由浸润-凝固控制的第Ⅱ阶段和完全由浸润控制的第Ⅲ阶段.不管是否施加超声场,表面层厚度变化的规律相似,只不过施加超声场后表面层厚度有不同程度的减小,同时表面层的组织变得更加均匀

稀土铈对热浸镀铝层组织和性能的影响

研究了稀土铈对热浸镀铝层组织结构、耐蚀和耐热性能的影响。结果表明：稀土铈质量分数低于0．3％时，热浸镀铝层的耐蚀性能和高温抗氧化性能都得到提高，超过此含量镀层的性能下降。稀土铈使得过渡层由锯齿形结构转变为平滑结构，使镀层中FeAl3析出相在表层中呈网状分布，随其含量增加过渡层厚度减小。稀土含量超过0．3％时，稀土化合物在表层中呈条块状第二相析出并偏聚，并且随著稀土铈含量增加，表面层中稀土化合物呈块状，且偏聚程度加大

扩散处理热浸镀铝钢高温抗氧化行为的研究

对经不同扩散工艺处理的热浸镀铝层高温抗氧化性进行了研究,通过SEM、TEM、XRD分析了经扩散处理后,热浸镀铝层高温氧化过程中组织结构的变化情况,分析了热浸镀铝层高温抗氧化性能和微观结构的关系,确定了提高热浸镀铝层高温抗氧化性的适宜扩散温度。结果表明,经750℃扩散处理,热浸镀铝层结构由较厚的外表层(Fe2Al5+FeAl2)及内层(FeAl+条状:FeAl2)组成,条状FeAl2的形成为氧提供了扩散通道,其抗氧化性较差;经950℃扩散处理,镀层外表层变薄,外表层转为单一FeAl2、内层为FeAl,并出现早期内氧化裂纹,其抗氧化性较差:当扩散处理温度为850℃时,镀层外表层变薄,结构转为FeAl2+少量Fe2Al5,而内层增厚,其结构为FeAl+球状FeAl2,而内层FeAl2球化,增强了氧由内层向基体扩散的阻碍作用,使氧只能逐层形成Al2O3+Fe2O3的氧化膜,提高了镀层的高温抗氧化性

Effect of Rare Earth Element Cerium on Properties and Microstructure of Hot Dip Aluminum Coating on Q235 Steel

研究了稀土铈对热浸镀铝层组织结构、耐蚀和耐热性能的影响。结果表明：稀土铈质量分数低于0．3％时，热浸镀铝层的耐蚀性能和高温抗氧化性能都得到提高，超过此含量镀层的性能下降。稀土铈使得过渡层由锯齿形结构转变为平滑结构，使镀层中FeAl3析出相在表层中呈网状分布，随其含量增加过渡层厚度减小。稀土含量超过0．3％时，稀土化合物在表层中呈条块状第二相析出并偏聚，并且随著稀土铈含量增加，表面层中稀土化合物呈块状，且偏聚程度加大

Effect of diffusion on coating microstructure and oxidation resistance of aluminizing steel

The effect of diffuse treatment on coating microstructure and oxidation resistance at high-temperature of hot-dip aluminum were studied by means of TEM, SEM and XRD. The results show that, the diffusion temperature has significant effect on structure of coatings and its oxidation resistance. After diffusion at 750 degreesC, the coating consists of thick outer surface layer (Fe2Al5+ FeAl2), thin internal layer (FeAl + stripe FeAl2), and its oxidation resistance is poor. After diffusion at 950 degreesC, the outer surface layer is composed of single FeAl2 phase, the internal layer is composed of FeAl phase, and its oxidation resistance declines due to the occurrence of early stage internal oxidation cracks in the coating. After diffusion at 850 degreesC, the outer surface layer becomes thinner and consists of FeAl2 Fe2Al5(small amount), the internal layer becomes thicker and consists of FeAl+spherical FeAl2, and the spheroidized FeAl2 phase in the internal layer and its existing in FeAl phase steadily improve the oxidation resistance of the coating

Effect of diffusion on coating microstructure and oxidation resistance of aluminizing steel

The effect of diffuse treatment on coating microstructure and oxidation resistance at high-temperature of hot-dip aluminum were studied by means of TEM, SEM and XRD. The results show that, the diffusion temperature has significant effect on structure of coatings and its oxidation resistance. After diffusion at 750 degreesC, the coating consists of thick outer surface layer (Fe2Al5+ FeAl2), thin internal layer (FeAl + stripe FeAl2), and its oxidation resistance is poor. After diffusion at 950 degreesC, the outer surface layer is composed of single FeAl2 phase, the internal layer is composed of FeAl phase, and its oxidation resistance declines due to the occurrence of early stage internal oxidation cracks in the coating. After diffusion at 850 degreesC, the outer surface layer becomes thinner and consists of FeAl2 Fe2Al5(small amount), the internal layer becomes thicker and consists of FeAl+spherical FeAl2, and the spheroidized FeAl2 phase in the internal layer and its existing in FeAl phase steadily improve the oxidation resistance of the coating