As oil and gas exploration moves into deeper waters,marine risers are subjected to increasingly complex service conditions,including vessel motions,ocean currents,seabed-soil interactions,and internal flow effects.Thi...As oil and gas exploration moves into deeper waters,marine risers are subjected to increasingly complex service conditions,including vessel motions,ocean currents,seabed-soil interactions,and internal flow effects.This work establishes a dynamic behavior model of steel catenary risers(SCRs)with varying curvatures subjected to internal flow and external currents and considers the effects of pipe-soil interactions on the curvature profile.The governing equation is solved via the generalized integral transform technique(GITT),which yields a semi-analytical solution of a high-order nonlinear partial differential equation.Parametric studies are then performed to analyze the effects of varying curvature on the vibration frequency and amplitude of SCRs.The vibration frequency and amplitude increase with the touchdown angle and hang-off angle,although the effect of the hang-off angle is negligible.Additionally,as the curvature increases along the centerline axis,the position of the maximum amplitude of the SCR moves upward.展开更多
目的:从“肿瘤异质化”角度出发,通过多种基因编码蛋白(Bcl-2／Bax,Cath-D和VEGF)在肠型胃癌和弥漫型胃癌中的表达,探讨二型胃癌不同生物学特性的分子学基础．方法:采用免疫组化SP法检测Bcl-2／Bax, cathepsin-D(Cath-D)和VEGF在胃癌及...目的:从“肿瘤异质化”角度出发,通过多种基因编码蛋白(Bcl-2／Bax,Cath-D和VEGF)在肠型胃癌和弥漫型胃癌中的表达,探讨二型胃癌不同生物学特性的分子学基础．方法:采用免疫组化SP法检测Bcl-2／Bax, cathepsin-D(Cath-D)和VEGF在胃癌及正常胃组织的表达．结果:Bcl-2／Bax,Cath-D和VEGF阳性表达率在胃癌组织中与癌旁正常胃黏膜组织中比较 (分别为44．59％ vs 27.30％;58．11％ vs 71．62％; 77．00％vs 21．60％;71．62％vs 14．86％)均有显著性差异(P<0．05),弥漫型胃癌中Bcl-2和 Cath-D阳性细胞指数明显高于肠型胃癌(分别为29．14±24．70 vs 19．80±27．37和52．59± 33．76 vs 29．21±39．67),而Bax阳性细胞指数 (分别为32．56±35．55 vs 47．74±27．43)明显低于肠型胃癌,差异均有显著性(P<0．05),VEGF 阳性细胞表达指数在不同胃癌浸润深度组间比较(早期胃癌7．13±15．81 vs 肌层浸润62．77 ±44．37 vs 浆膜浸润40．82±42．70)及有无淋巴结转移组间比较(42．05±42．61 vs 34．15± 42．52)有显著性差异(P<0．05)．结论:Bcl-2／Bax,Cath-D和VEGF分别参与了胃癌的发生,浸润进展和转移．二型胃癌在组织学发生相同的基础上由于在胃癌演进过程中有不同附加基因参与(Bcl-2／Bax和Cath-D), 使弥漫型胃癌获得了与肠型胃癌有所不同的亚克隆过程,因而表现为生物学特性的异质化．展开更多
基金financially supported by the National Natural Science Foundation of China(Grant No.52201312).
文摘As oil and gas exploration moves into deeper waters,marine risers are subjected to increasingly complex service conditions,including vessel motions,ocean currents,seabed-soil interactions,and internal flow effects.This work establishes a dynamic behavior model of steel catenary risers(SCRs)with varying curvatures subjected to internal flow and external currents and considers the effects of pipe-soil interactions on the curvature profile.The governing equation is solved via the generalized integral transform technique(GITT),which yields a semi-analytical solution of a high-order nonlinear partial differential equation.Parametric studies are then performed to analyze the effects of varying curvature on the vibration frequency and amplitude of SCRs.The vibration frequency and amplitude increase with the touchdown angle and hang-off angle,although the effect of the hang-off angle is negligible.Additionally,as the curvature increases along the centerline axis,the position of the maximum amplitude of the SCR moves upward.
文摘目的:从“肿瘤异质化”角度出发,通过多种基因编码蛋白(Bcl-2／Bax,Cath-D和VEGF)在肠型胃癌和弥漫型胃癌中的表达,探讨二型胃癌不同生物学特性的分子学基础．方法:采用免疫组化SP法检测Bcl-2／Bax, cathepsin-D(Cath-D)和VEGF在胃癌及正常胃组织的表达．结果:Bcl-2／Bax,Cath-D和VEGF阳性表达率在胃癌组织中与癌旁正常胃黏膜组织中比较 (分别为44．59％ vs 27.30％;58．11％ vs 71．62％; 77．00％vs 21．60％;71．62％vs 14．86％)均有显著性差异(P<0．05),弥漫型胃癌中Bcl-2和 Cath-D阳性细胞指数明显高于肠型胃癌(分别为29．14±24．70 vs 19．80±27．37和52．59± 33．76 vs 29．21±39．67),而Bax阳性细胞指数 (分别为32．56±35．55 vs 47．74±27．43)明显低于肠型胃癌,差异均有显著性(P<0．05),VEGF 阳性细胞表达指数在不同胃癌浸润深度组间比较(早期胃癌7．13±15．81 vs 肌层浸润62．77 ±44．37 vs 浆膜浸润40．82±42．70)及有无淋巴结转移组间比较(42．05±42．61 vs 34．15± 42．52)有显著性差异(P<0．05)．结论:Bcl-2／Bax,Cath-D和VEGF分别参与了胃癌的发生,浸润进展和转移．二型胃癌在组织学发生相同的基础上由于在胃癌演进过程中有不同附加基因参与(Bcl-2／Bax和Cath-D), 使弥漫型胃癌获得了与肠型胃癌有所不同的亚克隆过程,因而表现为生物学特性的异质化．
