目的观察单相抑郁障碍患者和双相抑郁障碍患者的睡眠特征以及其认知功能的差异。方法选取2015 02—2016 10茂名市第三人民医院院就诊的单相抑郁障碍患者73例(单相组)、双相抑郁障碍患者76例(双相组),以及同期的健康志愿者60例(对照组)...目的观察单相抑郁障碍患者和双相抑郁障碍患者的睡眠特征以及其认知功能的差异。方法选取2015 02—2016 10茂名市第三人民医院院就诊的单相抑郁障碍患者73例(单相组)、双相抑郁障碍患者76例(双相组),以及同期的健康志愿者60例(对照组)。采用多导睡眠监测系统对受试者的睡眠特征进行监测比较,采用改良过的韦氏成人智力量表(Wechsler Adult Intelligence Scale,WAIS)评定受试者的语言智商、操作智商和总智商;采用韦克斯勒成人记忆量表(Wechsler memory scale,WMS)评定受试者的记忆能力;采用功能失调性态度问卷(Dysfunctional attitudes scales,DAS)评估认知结构。结果 3组受试者的多导睡眠监测指标中,除第2期睡眠时间/比例和快速动眼期睡眠时间/比例外,其他指标差异均有统计学意义( P <0.05)。单相组与双相组患者在总睡眠时间、觉醒时间、觉醒次数、睡眠潜伏期、第1期时间/比例和第3期时间/比例中,差异均有统计学意义( P <0.05)。3组患者WAIS和WMS评分比较,差异有统计学意义( P <0.05)。单相组和双相组在总智商和记忆商数比较中,差异有统计学意义( P <0.05),但2组的语言智商和操作智商比较,差异无统计学意义( P >0.05)。3组受试者DAS评分差异存在统计学意义,双相组显著高于单相组( P <0.05)。其中强制性、依赖性、认知哲学方面,双相组的评分显著高于单相组( P <0.05);但2组患者的脆弱性、吸引和排斥、完美性、寻求赞许及自主性态度方面比较,差异无统计学意义( P >0.05)。结论 单相抑郁障碍和双相抑郁障碍患者均存在睡眠进程和睡眠结构紊乱的问题,认知能力也受到一定程度的损伤,其中双相抑郁患者更为严重。展开更多
BACKGROUND： According to observable behaviors, sleep and wakefulness are two fundamentally different behavioral states. Although electroencephalogram （EEG） is traditionally used to define sleep stage, it is difficu...BACKGROUND： According to observable behaviors, sleep and wakefulness are two fundamentally different behavioral states. Although electroencephalogram （EEG） is traditionally used to define sleep stage, it is difficult to detect or to quantify microarousals or disruptions during sleep. In addition initial sleep cannot be defined. It is thought that the wake-sleep transition cannot be defined by EEG patterns. OBJECTIVE： To observe the behavioral response magnitude during wake-sleep transition by EEG monitoring and to define the wake-sleep transition. DESIGN, TIME AND SETTING： A behavioral and neural network study was performed at the Key Lab of Human Being Development and Mental Health of Central China Normal University, and Lab of Brain and Cognitive Science of South Central University for Nationalities, China in July 2007. PARTICIPANTS： A total of 30 healthy volunteers, of equal gender and aged （19.7 ± 1.1 ） years, were recruited from the Central China Normal University, China for this study. None of the subjects had undergone EEG recording prior to this study or received any medication for sleep disturbances. METHODS： A novel adaptive approach was applied to detect wake-sleep transition, which avoided stimulus-induced waking. To test the difference between wake state and wake-sleep transition, the amount of self-information and mutual-information were effective parameters to analyze wake-sleep transition. MAIN OUTCOME MEASURES： The following parameters were measured： morphological changes in reaction time-magnitude, as well as correlation between phase changes and sleep, and wake and wake-sleep transition. RESULTS： There were three typical phases in morphological changes of reaction time-magnitude. With regard to the behavioral definition and criterion for sleep, the phase morphological characteristics displayed good correlation with behavioral states, such as sleep, wakefulness, and sleep onset. Entropy as an indicator of brain cognitive processes was introduced to test for differences b展开更多
Presently developed two-phase turbulence models under-predict the gas turbulent fluctuation, because their turbulence modification models cannot fully reflect the effect of particles. In this paper, a two-time-scale d...Presently developed two-phase turbulence models under-predict the gas turbulent fluctuation, because their turbulence modification models cannot fully reflect the effect of particles. In this paper, a two-time-scale dissipation model of turbulence modification, developed for the two-phase velocity correlation and for the dissipation rate of gas turbulent kinetic energy, is proposed and used to simulate sudden-expansion and swirling gas-particle flows. The proposed two-time scale model gives better results than the single-time scale model. Besides, a gas turbulence augmentation model accounting for the f＇mite-size particle wake effect in the gas Reynolds stress equation is proposed. The proposed turbulence modification models are used to simulate two-phase pipe flows. It can properly predict both turbulence reduction and turbulence enhancement for a certain size of particles observed in experiments.展开更多
In this study,the performance of a twin-screw propeller under the influence of the wake field of a fully appended ship was investigated using a coupled Reynolds-averaged Navier–Stokes(RANS)/boundary element method(BE...In this study,the performance of a twin-screw propeller under the influence of the wake field of a fully appended ship was investigated using a coupled Reynolds-averaged Navier–Stokes(RANS)/boundary element method(BEM)code.The unsteady BEM is an efficient approach to predicting propeller performance.By applying the time-stepping method in the BEM solver,the trailing vortex sheet pattern of the propeller can be accurately captured at each time step.This is the main innovation of the coupled strategy.Furthermore,to ascertain the effect of the wake field of the ship with acceptable accuracy,a RANS solver was developed.A finite volume method was used to discretize the Navier–Stokes equations on fully unstructured grids.To simulate ship motions,the volume of the fluid method was applied to the RANS solver.The validation of each solver(BEM/RANS)was separately performed,and the results were compared with experimental data.Ultimately,the BEM and RANS solvers were coupled to estimate the performance of a twin-screw propeller,which was affected by the wake field of the fully appended hull.The proposed model was applied to a twin-screw oceanography research vessel.The results demonstrated that the presented model can estimate the thrust coefficient of a propeller with good accuracy as compared to an experimental self-propulsion test.The wake sheet pattern of the propeller in open water(uniform flow)was also compared with the propeller in a real wake field.展开更多
<b>Backgrounds:</b> Sleepiness is reported to predict sleep quality, academic performance and self-regulation. This study aimed to discover determinants of sleepiness. <b>Methods:</b> On 2722 q...<b>Backgrounds:</b> Sleepiness is reported to predict sleep quality, academic performance and self-regulation. This study aimed to discover determinants of sleepiness. <b>Methods:</b> On 2722 questionnaires obtained from pupils in grades 5 - 12 in the Kanto district of Japan, lifestyle habits associated with sleepiness were analyzed using a multivariable logistic regression model. <b>Results:</b> The rate of sleepy pupils (who feel sleepy during class as often and always) increased from elementary school (6.3%) to senior high school (42.4%) via junior high school (17.1%). Higher grade (adjusted odds ratio [OR], 1.28;95% confidence interval [CI], 1.21 - 1.37;p < 0.001), later bedtime before school day (OR, 1.41;CI, 1.26 - 1.57;p < 0.001), longer non-school day screen time (OR, 1.27;CI, 1.16 - 1.40;p < 0.001), poor self-reported academic performance (OR, 1.41;CI, 1.24 - 1.60;p < 0.001), skipping breakfast (OR, 1.18;CI, 1.01 - 1.39;p = 0.041), earlier wake time on school day (OR, 0.84;CI, 0.71 - 0.98;p = 0.026), and higher after-school (OR, 1.03;CI, 1.02 - 1.04;p < 0.001) and physical activities (OR, 1.06;CL, 1.03 - 1.10;p < 0.001) were independently associated with sleepy pupils. <b>Conclusions:</b> To reduce adolescents’ sleepiness in the Kanto district of Japan, we recommend them to have adequate waking time, and to avoid late bedtime, breakfast skipping, excessive screen time, after-school activity, and physical activity. Further prospective studies are needed to confirm involvements of these recommended factors in sleepiness and both physical and mental health outcomes.展开更多
The cross-flow(CF)vortex-induced vibration(VIV)of a deepwater steep wave riser(SWR)subjected to uniform or shear flow loads is investigated numerically.The model is based on a three-dimensional(3D)nonlinear elastic ro...The cross-flow(CF)vortex-induced vibration(VIV)of a deepwater steep wave riser(SWR)subjected to uniform or shear flow loads is investigated numerically.The model is based on a three-dimensional(3D)nonlinear elastic rod theory coupled with a wake oscillator model.In this numerical simulation,the nonlinear motion equations of the riser with large deformation features are established in a global coordinate system to avoid the transformation between global and local coordinate systems,and are discretized with the time-domain finite element method(FEM).A wakeoscillator model is employed to study the vortex shedding,and the lift force generated by the wake flow is described in a van der Pol equation.A Newmark-βiterative scheme is used to solve their coupling equation for the VIV response of the SWR.The developed model is validated against the existing experimental results for the VIV response of the top-tension riser(TTR).Then,the numerical simulations are executed to determine VIV characteristics of the SWR.The effects of both flow velocity and the spanwise length of the flow field on the drag coefficient in the inline(IL)direction and the lift coefficient in the CF direction are investigated systematically.The results indicate that compared with TTR,the low frequency and multi-modal vibration are the main components of the SWR due to the large deformation and flexible characteristics.For shear flow,the multi-frequency resonance dominates the VIV response of the SWR,especially at the hang-off segment.展开更多
文摘目的分析青少年中睡眠习惯和心理行为健康之间的相关性,为预防和改善青少年群体心理健康提供参考依据。方法通过分层整群抽样的方式调查了4 966名11~20岁的青少年。青少年睡眠卫生评估量表修订版(MASHS)用来测量其睡眠状况及行为习惯。儿童长处和不足问卷(Strengths and Difficulties Questionnaire,SDQ)用来评估青少年心理行为健康状况。结果参与调查的青少年中,46.4%工作日平均每天睡眠时间少于8h,7.6%周末平均睡眠时间少于8h,47.5%工作日入睡时间晚于22:00点,39.8%周末入睡时间晚于22:30,45.2%周末觉醒时间晚于8:00,22.55%睡眠规律性差;8.7%的青少年存在心理行为问题,在控制了潜在的混杂因素后,工作日平均睡眠时间少于8h/d(OR=1.77,CI:1.13~2.76,P=0.012),周末的平均睡眠时间少于8h/d(OR=1.65,CI:1.12~2.43,P=0.011),工作日入睡时间晚于22:00点(OR=1.73,CI:1.30~2.31,P<0.001),周末入睡时间晚于22:30点(OR=1.37,CI:1.07~1.77,P=0.014),周末的觉醒时间晚于8点(OR=1.30,CI:1.02~1.66,P=0.032),睡眠不规律(OR=3.11,CI:2.41~4.01,P<0.001)等5个睡眠习惯变量与青少年心理问题显著相关。结论应加强对青少年的睡眠卫生教育,帮助其培养良好的睡眠习惯,特别是充足的睡眠时间和规律的作息习惯,以促进其心理健康。
文摘目的观察单相抑郁障碍患者和双相抑郁障碍患者的睡眠特征以及其认知功能的差异。方法选取2015 02—2016 10茂名市第三人民医院院就诊的单相抑郁障碍患者73例(单相组)、双相抑郁障碍患者76例(双相组),以及同期的健康志愿者60例(对照组)。采用多导睡眠监测系统对受试者的睡眠特征进行监测比较,采用改良过的韦氏成人智力量表(Wechsler Adult Intelligence Scale,WAIS)评定受试者的语言智商、操作智商和总智商;采用韦克斯勒成人记忆量表(Wechsler memory scale,WMS)评定受试者的记忆能力;采用功能失调性态度问卷(Dysfunctional attitudes scales,DAS)评估认知结构。结果 3组受试者的多导睡眠监测指标中,除第2期睡眠时间/比例和快速动眼期睡眠时间/比例外,其他指标差异均有统计学意义( P <0.05)。单相组与双相组患者在总睡眠时间、觉醒时间、觉醒次数、睡眠潜伏期、第1期时间/比例和第3期时间/比例中,差异均有统计学意义( P <0.05)。3组患者WAIS和WMS评分比较,差异有统计学意义( P <0.05)。单相组和双相组在总智商和记忆商数比较中,差异有统计学意义( P <0.05),但2组的语言智商和操作智商比较,差异无统计学意义( P >0.05)。3组受试者DAS评分差异存在统计学意义,双相组显著高于单相组( P <0.05)。其中强制性、依赖性、认知哲学方面,双相组的评分显著高于单相组( P <0.05);但2组患者的脆弱性、吸引和排斥、完美性、寻求赞许及自主性态度方面比较,差异无统计学意义( P >0.05)。结论 单相抑郁障碍和双相抑郁障碍患者均存在睡眠进程和睡眠结构紊乱的问题,认知能力也受到一定程度的损伤,其中双相抑郁患者更为严重。
文摘BACKGROUND： According to observable behaviors, sleep and wakefulness are two fundamentally different behavioral states. Although electroencephalogram （EEG） is traditionally used to define sleep stage, it is difficult to detect or to quantify microarousals or disruptions during sleep. In addition initial sleep cannot be defined. It is thought that the wake-sleep transition cannot be defined by EEG patterns. OBJECTIVE： To observe the behavioral response magnitude during wake-sleep transition by EEG monitoring and to define the wake-sleep transition. DESIGN, TIME AND SETTING： A behavioral and neural network study was performed at the Key Lab of Human Being Development and Mental Health of Central China Normal University, and Lab of Brain and Cognitive Science of South Central University for Nationalities, China in July 2007. PARTICIPANTS： A total of 30 healthy volunteers, of equal gender and aged （19.7 ± 1.1 ） years, were recruited from the Central China Normal University, China for this study. None of the subjects had undergone EEG recording prior to this study or received any medication for sleep disturbances. METHODS： A novel adaptive approach was applied to detect wake-sleep transition, which avoided stimulus-induced waking. To test the difference between wake state and wake-sleep transition, the amount of self-information and mutual-information were effective parameters to analyze wake-sleep transition. MAIN OUTCOME MEASURES： The following parameters were measured： morphological changes in reaction time-magnitude, as well as correlation between phase changes and sleep, and wake and wake-sleep transition. RESULTS： There were three typical phases in morphological changes of reaction time-magnitude. With regard to the behavioral definition and criterion for sleep, the phase morphological characteristics displayed good correlation with behavioral states, such as sleep, wakefulness, and sleep onset. Entropy as an indicator of brain cognitive processes was introduced to test for differences b
基金Supported by the State Key Development Program for Basic Research of China （No.2006CB200305）, the National Natural Science Foundation of China （No.50376004）, and Ph.D. Program Foundation of Ministry of Education of China （No.20030007028）.
文摘Presently developed two-phase turbulence models under-predict the gas turbulent fluctuation, because their turbulence modification models cannot fully reflect the effect of particles. In this paper, a two-time-scale dissipation model of turbulence modification, developed for the two-phase velocity correlation and for the dissipation rate of gas turbulent kinetic energy, is proposed and used to simulate sudden-expansion and swirling gas-particle flows. The proposed two-time scale model gives better results than the single-time scale model. Besides, a gas turbulence augmentation model accounting for the f＇mite-size particle wake effect in the gas Reynolds stress equation is proposed. The proposed turbulence modification models are used to simulate two-phase pipe flows. It can properly predict both turbulence reduction and turbulence enhancement for a certain size of particles observed in experiments.
基金supported by the Inner Mongolia Autonomous Region Open Major Basic Research Project(Grant No.20120905)the National Natural Science Foundation of China(Grant No.51666014)
文摘Wind tunnel experiments of the wake characteristics of a two-blade wind turbine, in the downstream region of 0
文摘In this study,the performance of a twin-screw propeller under the influence of the wake field of a fully appended ship was investigated using a coupled Reynolds-averaged Navier–Stokes(RANS)/boundary element method(BEM)code.The unsteady BEM is an efficient approach to predicting propeller performance.By applying the time-stepping method in the BEM solver,the trailing vortex sheet pattern of the propeller can be accurately captured at each time step.This is the main innovation of the coupled strategy.Furthermore,to ascertain the effect of the wake field of the ship with acceptable accuracy,a RANS solver was developed.A finite volume method was used to discretize the Navier–Stokes equations on fully unstructured grids.To simulate ship motions,the volume of the fluid method was applied to the RANS solver.The validation of each solver(BEM/RANS)was separately performed,and the results were compared with experimental data.Ultimately,the BEM and RANS solvers were coupled to estimate the performance of a twin-screw propeller,which was affected by the wake field of the fully appended hull.The proposed model was applied to a twin-screw oceanography research vessel.The results demonstrated that the presented model can estimate the thrust coefficient of a propeller with good accuracy as compared to an experimental self-propulsion test.The wake sheet pattern of the propeller in open water(uniform flow)was also compared with the propeller in a real wake field.
文摘<b>Backgrounds:</b> Sleepiness is reported to predict sleep quality, academic performance and self-regulation. This study aimed to discover determinants of sleepiness. <b>Methods:</b> On 2722 questionnaires obtained from pupils in grades 5 - 12 in the Kanto district of Japan, lifestyle habits associated with sleepiness were analyzed using a multivariable logistic regression model. <b>Results:</b> The rate of sleepy pupils (who feel sleepy during class as often and always) increased from elementary school (6.3%) to senior high school (42.4%) via junior high school (17.1%). Higher grade (adjusted odds ratio [OR], 1.28;95% confidence interval [CI], 1.21 - 1.37;p < 0.001), later bedtime before school day (OR, 1.41;CI, 1.26 - 1.57;p < 0.001), longer non-school day screen time (OR, 1.27;CI, 1.16 - 1.40;p < 0.001), poor self-reported academic performance (OR, 1.41;CI, 1.24 - 1.60;p < 0.001), skipping breakfast (OR, 1.18;CI, 1.01 - 1.39;p = 0.041), earlier wake time on school day (OR, 0.84;CI, 0.71 - 0.98;p = 0.026), and higher after-school (OR, 1.03;CI, 1.02 - 1.04;p < 0.001) and physical activities (OR, 1.06;CL, 1.03 - 1.10;p < 0.001) were independently associated with sleepy pupils. <b>Conclusions:</b> To reduce adolescents’ sleepiness in the Kanto district of Japan, we recommend them to have adequate waking time, and to avoid late bedtime, breakfast skipping, excessive screen time, after-school activity, and physical activity. Further prospective studies are needed to confirm involvements of these recommended factors in sleepiness and both physical and mental health outcomes.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.52111530137 and 52025112)the Natural Science Found of Jiangsu Province(Grant No.BK20160556)the Jiangsu Provincial Higher Education Natural Science Research Major Project(Grant No.18KJA580003)。
文摘The cross-flow(CF)vortex-induced vibration(VIV)of a deepwater steep wave riser(SWR)subjected to uniform or shear flow loads is investigated numerically.The model is based on a three-dimensional(3D)nonlinear elastic rod theory coupled with a wake oscillator model.In this numerical simulation,the nonlinear motion equations of the riser with large deformation features are established in a global coordinate system to avoid the transformation between global and local coordinate systems,and are discretized with the time-domain finite element method(FEM).A wakeoscillator model is employed to study the vortex shedding,and the lift force generated by the wake flow is described in a van der Pol equation.A Newmark-βiterative scheme is used to solve their coupling equation for the VIV response of the SWR.The developed model is validated against the existing experimental results for the VIV response of the top-tension riser(TTR).Then,the numerical simulations are executed to determine VIV characteristics of the SWR.The effects of both flow velocity and the spanwise length of the flow field on the drag coefficient in the inline(IL)direction and the lift coefficient in the CF direction are investigated systematically.The results indicate that compared with TTR,the low frequency and multi-modal vibration are the main components of the SWR due to the large deformation and flexible characteristics.For shear flow,the multi-frequency resonance dominates the VIV response of the SWR,especially at the hang-off segment.
