A wear resistant (Cr,Fe)7C3/γ-Fe ceramal composite coating was fabricated on substrate of a 0.45% C carbon steel by plasma transferred arc (PTA) cladding process using the Fe-Cr-C elemental powder blends. The microst...A wear resistant (Cr,Fe)7C3/γ-Fe ceramal composite coating was fabricated on substrate of a 0.45% C carbon steel by plasma transferred arc (PTA) cladding process using the Fe-Cr-C elemental powder blends. The microstructure, microhardness and dry sliding wear resistance of the coat- ing were evaluated. Results indicate that the plasma transferred arc clad ceramal composite coat- ing has a rapidly solidified microstructure consisting of’ blocky primary (Cr,Fe)7C3 and the inter- blocky (Cr,Fe)7C3/γ-Fe eutectics and is metallurgically bonded to the 0.45%C carbon steel sub- strate. The ceramal composite coating has high hardness and excellent wear resistance under dry sliding wear test condition.展开更多
肠道病毒A71型(enterovirus A71,EV-A71)是导致手足口病(hand-foot-mouth disease,HFMD)的主要病原体之一,目前对其治疗尚无特异高效的抗病毒药物。研究表明,细胞膜转运相关分子参与病毒的入侵、复制以及感染性子代病毒颗粒的释放。为...肠道病毒A71型(enterovirus A71,EV-A71)是导致手足口病(hand-foot-mouth disease,HFMD)的主要病原体之一,目前对其治疗尚无特异高效的抗病毒药物。研究表明,细胞膜转运相关分子参与病毒的入侵、复制以及感染性子代病毒颗粒的释放。为寻找宿主中可有效抑制EV-A71感染的细胞膜转运分子,本研究以人结肠癌细胞(Caco-2)为靶细胞,采用RNA干扰技术下调细胞中14个转运相关膜蛋白的表达。结果显示,针对这14个膜蛋白目的基因设计的小干扰RNA(small interfering RNA,siRNA)均能有效抑制靶蛋白的表达,有效抑制率达50%以上(P<0.05),且各siRNA转染均未对细胞产生明显毒性。其中,转染ATP结合盒转运蛋白C3(ATP-binding cassette transport subfamily C member 3,ABCC3)siRNA(SEQ ID NO:1)和溶质载体家族7成员7(solute carrier family 7 member 7,SLC7A7)siRNA(SEQ ID NO:29)的干扰效率分别高达87.82%和88.44%。ABCC3和SLC7A7基因下调可明显抑制EV-A71的复制,抑制率分别达87.05%和81.66%。结果表明,ABCC3和SLC7A7在EV-A71感染Caco-2细胞中发挥着重要作用,可为临床EV-A71感染的预防和治疗提供潜在靶点。展开更多
文摘A wear resistant (Cr,Fe)7C3/γ-Fe ceramal composite coating was fabricated on substrate of a 0.45% C carbon steel by plasma transferred arc (PTA) cladding process using the Fe-Cr-C elemental powder blends. The microstructure, microhardness and dry sliding wear resistance of the coat- ing were evaluated. Results indicate that the plasma transferred arc clad ceramal composite coat- ing has a rapidly solidified microstructure consisting of’ blocky primary (Cr,Fe)7C3 and the inter- blocky (Cr,Fe)7C3/γ-Fe eutectics and is metallurgically bonded to the 0.45%C carbon steel sub- strate. The ceramal composite coating has high hardness and excellent wear resistance under dry sliding wear test condition.
文摘肠道病毒A71型(enterovirus A71,EV-A71)是导致手足口病(hand-foot-mouth disease,HFMD)的主要病原体之一,目前对其治疗尚无特异高效的抗病毒药物。研究表明,细胞膜转运相关分子参与病毒的入侵、复制以及感染性子代病毒颗粒的释放。为寻找宿主中可有效抑制EV-A71感染的细胞膜转运分子,本研究以人结肠癌细胞(Caco-2)为靶细胞,采用RNA干扰技术下调细胞中14个转运相关膜蛋白的表达。结果显示,针对这14个膜蛋白目的基因设计的小干扰RNA(small interfering RNA,siRNA)均能有效抑制靶蛋白的表达,有效抑制率达50%以上(P<0.05),且各siRNA转染均未对细胞产生明显毒性。其中,转染ATP结合盒转运蛋白C3(ATP-binding cassette transport subfamily C member 3,ABCC3)siRNA(SEQ ID NO:1)和溶质载体家族7成员7(solute carrier family 7 member 7,SLC7A7)siRNA(SEQ ID NO:29)的干扰效率分别高达87.82%和88.44%。ABCC3和SLC7A7基因下调可明显抑制EV-A71的复制,抑制率分别达87.05%和81.66%。结果表明,ABCC3和SLC7A7在EV-A71感染Caco-2细胞中发挥着重要作用,可为临床EV-A71感染的预防和治疗提供潜在靶点。
