目的探讨血清铁蛋白及相关临床特征对弥漫性大B细胞淋巴瘤(diffuse large B cell lymphoma,DLBCL)患者的预后影响。方法收集2015年3月—2020年11月7家医疗中心确诊的202例初诊DLBCL且具有确切血清铁蛋白数值的患者的一般资料、实验室及...目的探讨血清铁蛋白及相关临床特征对弥漫性大B细胞淋巴瘤(diffuse large B cell lymphoma,DLBCL)患者的预后影响。方法收集2015年3月—2020年11月7家医疗中心确诊的202例初诊DLBCL且具有确切血清铁蛋白数值的患者的一般资料、实验室及影像学检查、免疫组化染色结果,通过Max Stat统计量计算铁蛋白、年龄和白蛋白的最佳截断值,使用Cox比例风险模型进行单因素和多因素分析以确定影响DLBCL患者生存结局的变量并进行亚组分析。结果202例初诊DLBCL患者中,男性105例(52%)、女性97例(48%),中位年龄58岁,Ann ArborⅠ-Ⅱ期74例(36.6%),中位随访时间36个月。Mann-Whitney U检验结果表明存活组与死亡组患者的血清铁蛋白、年龄及白蛋白的数值差异有统计学意义(P<0.05);血清铁蛋白、年龄和白蛋白的最佳截断值分别为246μg/L、74岁和38.5g/L;单因素、多因素分析表明铁蛋白、年龄和东部肿瘤协作组(Eastern Cooperative Oncology Group,ECOG)评分对DLBCL预后有影响;在国际预后指数(international prognostic index,IPI)低危和低中危组中,铁蛋白<246μg/L和铁蛋白≥246μg/L患者总生存期(overall survival,OS)差异显著(P<0.05),但在BCL-2^(+)组、BCL-6^(-)组、IPI高中危和高危组未发现明显差异。结论血清铁蛋白是DLBCL患者的不良预后因素,有助于区分IPI低风险患者中的预后较差者。展开更多
An improved nonsingular fast terminal sliding mode manifold based on scaled state error is proposed in this paper.It can significantly accelerate the convergence rate of the state error which is initially far from the...An improved nonsingular fast terminal sliding mode manifold based on scaled state error is proposed in this paper.It can significantly accelerate the convergence rate of the state error which is initially far from the origin and achieve the fixed-time convergence.In addition,conventional double power term based reaching law is improved to ensure the convergence of sliding state in the presence of disturbances.The proposed approach is applied to the hovering control of an unmanned underwater vehicle.The controller exhibits both fast convergence and strong robustness to model uncertainty and external disturbances.展开更多
Large unmanned underwater vehicles can carry big payloads for varied missions and it is desirable for them to possess an upright orientation during payload release.Their attitude can hardly be maintained during and af...Large unmanned underwater vehicles can carry big payloads for varied missions and it is desirable for them to possess an upright orientation during payload release.Their attitude can hardly be maintained during and after the phase of payload release.Releasing a payload from the vehicle induces uncertainties not only in rigid-body parameters,e.g,the moment of inertia tensor due to the varying distribution of the masses on board the vehicle,but also in the hydrodynamic derivatives due to the vehicle’s varying geometric profile.A nonlinear attitude stabilizer that is robust to these time-varying model uncertainties is proposed in this paper.Stability is guaranteed via Lyapunov stability theory.The simulation results verify the effectiveness of the proposed approach.展开更多
文摘An improved nonsingular fast terminal sliding mode manifold based on scaled state error is proposed in this paper.It can significantly accelerate the convergence rate of the state error which is initially far from the origin and achieve the fixed-time convergence.In addition,conventional double power term based reaching law is improved to ensure the convergence of sliding state in the presence of disturbances.The proposed approach is applied to the hovering control of an unmanned underwater vehicle.The controller exhibits both fast convergence and strong robustness to model uncertainty and external disturbances.
文摘Large unmanned underwater vehicles can carry big payloads for varied missions and it is desirable for them to possess an upright orientation during payload release.Their attitude can hardly be maintained during and after the phase of payload release.Releasing a payload from the vehicle induces uncertainties not only in rigid-body parameters,e.g,the moment of inertia tensor due to the varying distribution of the masses on board the vehicle,but also in the hydrodynamic derivatives due to the vehicle’s varying geometric profile.A nonlinear attitude stabilizer that is robust to these time-varying model uncertainties is proposed in this paper.Stability is guaranteed via Lyapunov stability theory.The simulation results verify the effectiveness of the proposed approach.
