Self-excited longitudinal combustion instabilities were investigated in a hypergolic liquid bipropellant combustor, which applied single dual-swirl coaxial injector. Hot-fire tests were conducted for four different in...Self-excited longitudinal combustion instabilities were investigated in a hypergolic liquid bipropellant combustor, which applied single dual-swirl coaxial injector. Hot-fire tests were conducted for four different injector geometries, while extensive tests on injection conditions were carried out for each injector geometry. The synchronous measurement of the pressure and heat release rate was applied, successfully capturing the process of the pressure and heat release rate enhanced coupling and developing into in-phase oscillation. By calculating Rayleigh index at the head and middle section of the chamber, it is shown that Rayleigh index of the middle section is even higher than that of the head, indicating a long heat release zone. When the combustion instability occurs, the pressure in propellant manifolds also oscillates with the same frequency and lags behind the oscillation in the combustor. Compared to the oscillation in the outer injector manifold, the oscillation in the inner injector manifold shows a higher correlation with that in the chamber in amplitude and phase. Based on numerical simulations of the multiphase cold flow inside the injector and combustion process in the chamber, it is found that injector geometries affect longitudinal combustion instability by changing spray cone angle. The spray with small cone angle is more sensitive to the modulation of longitudinal pressure wave in combustion simulations, which is more likely to excite the longitudinal combustion instability. Meanwhile, the combustion instability may be related to the pulsating coherent structure generated by the spray fluctuation, which is determined by injection conditions. Besides, a positive feedback closed-loop system associated with the active fluctuation and passive oscillation of the spray is believed to excite and sustain the longitudinal combustion instability.展开更多
BACKGROUND Dyslipidemia was strongly linked to stroke,however the relationship between dyslipidemia and its components and ischemic stroke remained unexplained.AIM To investigate the link between longitudinal changes ...BACKGROUND Dyslipidemia was strongly linked to stroke,however the relationship between dyslipidemia and its components and ischemic stroke remained unexplained.AIM To investigate the link between longitudinal changes in lipid profiles and dyslipidemia and ischemic stroke in a hypertensive population.METHODS Between 2013 and 2014,6094 hypertension individuals were included in this,and ischemic stroke cases were documented to the end of 2018.Longitudinal changes of lipid were stratified into four groups:(1)Normal was transformed into normal group;(2)Abnormal was transformed into normal group;(3)Normal was transformed into abnormal group;and(4)Abnormal was transformed into abnormal group.To examine the link between longitudinal changes in dyslipidemia along with its components and the risk of ischemic stroke,we utilized multivariate Cox proportional hazards models with hazard ratio(HR)and 95%CI.RESULTS The average age of the participants was 62.32 years±13.00 years,with 329 women making up 54.0%of the sample.Over the course of a mean follow-up of 4.8 years,143 ischemic strokes happened.When normal was transformed into normal group was used as a reference,after full adjustments,the HR for dyslipidemia and ischemic stroke among abnormal was transformed into normal group,normal was transformed into abnormal group and abnormal was transformed into abnormal Wei CC et al.Dyslipidemia changed and ischemic stroke WJCC https://www.wjgnet.com 2 February 6,2025 Volume 13 Issue 4 group were 1.089(95%CI:0.598-1.982;P=0.779),2.369(95%CI:1.424-3.941;P<0.001)and 1.448(95%CI:1.002-2.298;P=0.047)(P for trend was 0.233),respectively.CONCLUSION In individuals with hypertension,longitudinal shifts from normal to abnormal in dyslipidemia-particularly in total and low-density lipoprotein cholesterol-were significantly associated with the risk of ischemic stroke.展开更多
BACKGROUND Peer bullying victimization(PBV)is a significant public health issue that adolescents often face,with approximately one-third having experienced PBV.Understanding its interrelationships with mental health p...BACKGROUND Peer bullying victimization(PBV)is a significant public health issue that adolescents often face,with approximately one-third having experienced PBV.Understanding its interrelationships with mental health problems is crucial for effective intervention.This study aims to examine the longitudinal relationships between internalizing problems(depression and anxiety),externalizing problems(aggression),and PBV among middle school students using cross-lagged panel network analysis.AIM To examine the longitudinal relationships between internalizing problems(depression and anxiety),externalizing problems(aggression),and PBV among middle school students using cross-lagged panel network analysis.METHODS A total of 1260 middle school students(54.6%male)participated in this study.Data were collected at two time points(time 1 and time 2)using self-report questionnaires to assess PBV,depression,anxiety,and aggression.Cross-lagged panel network analysis was applied to examine the bi-directional relationships between these variables over time.RESULTS Depression,particularly a“sad mood,”was the most significant predictor of both PBV and aggression.Cyberbullying victimization also emerged as a key factor influencing depression and anxiety.While anxiety had weaker and less consistent effects on PBV,aggression was predominantly influenced by depressive symptoms and sleep disturbances.The analysis also identified key symptoms,such as a“sad mood”and sleep disturbances,as crucial targets for intervention to mitigate the cycle of PBV,depression,anxiety,and aggression.CONCLUSION This study provides important insights for bullying victimization prevention and intervention strategies:(1)Early identification and intervention targeting depression,particularly a“sad mood,”and sleep disturbances;(2)The importance of addressing cyberbullying as a distinct factor influencing mental health;and(3)The need for comprehensive,longitudinal approaches to understanding and intervening in the interconnected mental health issues among adolescents.展开更多
Point-of-care ultrasound(POCUS) is recognized as a valuable diagnostic tool,especially in resourcelimited settings(RLS).POCUS provides rapid diagnostic information that enables health professionals to make critical de...Point-of-care ultrasound(POCUS) is recognized as a valuable diagnostic tool,especially in resourcelimited settings(RLS).POCUS provides rapid diagnostic information that enables health professionals to make critical decisions at the bedside.^([1]) Despite the welldocumented benefits of POCUS,access to longitudinal,comprehensive training programs and a lack of trainee feedback are barriers to the widespread use of this technology in such settings.^([2])展开更多
The longitudinal ventilation strategy is commonly used for road tunnels in urban environment in Sweden.This is partly due to how tunnels in urban environment was planned and designed before the EU Directive[1](2004/54...The longitudinal ventilation strategy is commonly used for road tunnels in urban environment in Sweden.This is partly due to how tunnels in urban environment was planned and designed before the EU Directive[1](2004/54/EC)came in place.Even in new tunnels both to practical and economic reasons the use of longitudinal ventilation has been an outspoken demand from the Swedish road authority,SRA.Swedish law[2]requires that a risk analysis is carried out to demonstrate that an acceptable level of risk is achieved in the tunnels with longitudinal ventilation if there is a risk of queues.Otherwise transverse or semi-transverse ventilation strategy shall be used.During recent development,or a late awakening,it is clear that dense populated areas in Sweden will experience queues.This threatens the foundation of the Swedish modern tunnel safety concept which calls for enhancement.This paper presents the risk-reducing effect of three alternative strategies,enhancements package,focusing on evacuation safety for road users.It is a combination of traffic management,fixed firefighting systems,reduced distance between escape routes and regulation of traffic with dangerous goods.In addition,it provides a comprehensive review of safety system details,combined with a longitudinal ventilation concept.展开更多
How the strong segmentation of cascade reservoir dams and the spatiotemporal changes of sediment retention volume affect the river morphology adjustment in the reservoir area is a scientific issue worthy of exploratio...How the strong segmentation of cascade reservoir dams and the spatiotemporal changes of sediment retention volume affect the river morphology adjustment in the reservoir area is a scientific issue worthy of exploration.This study aims to reveal the adjustment mechanism of the thalweg longitudinal profile of cascade reservoirs.This study focuses on the Xiangjiaba and Xiluodu reservoirs located in the lower reaches of the Jinsha River.Utilizing multi-period observational data of thalweg elevation in reservoir reaches both before and after dam construction,the research employs statistical,geomorphological,and sedimentological methodologies to analyze variation characteristics in the measured curves,trend curves,and theoretical fitting curves of the thalweg longitudinal profile.The investigation ultimately reveals two distinct adjustment patterns in the longitudinal profiles of these cascade reservoirs:the concave curve type and the convex curve type.The former is characterized by weak riverbed scouring and silting changed to rapid aggradation in the upstream section of the reservoir area after dam closure,then changed to slow aggradation in the whole reservoir area,which is the common feature of reservoirs that were built earlier and are relatively located in the downstream(such as the Xiangjiaba Reservoir).The latter is characterized by a straight line or concave curve type with weak riverbed scouring and silting before the dam closure changed to a convex curve type with strong siltation after dam closure,which is the characteristic of reservoirs that were built later and are relatively located in the upstream(such as the Xiluodu Reservoir).The adjustment of the cascade reservoir longitudinal profile is controlled by the spatiotemporal changes of the sediment deposition volume and sedimentation rate in the reservoir area,and the alternating changes of the hydrodynamic gradient and regulation mode affect the spatial heterogeneity of the sedimentation rate.The research results are helpful for understanding the adjustment mechanism of the cascade reservoir longitudinal profile in similar areas and have a guiding role in predicting the adjustment trend of the cascade reservoir longitudinal profile without observation data.展开更多
The operational and regional conditions to which the prestressed concrete sleeper(PCS)is subjected in a railway track significantly contribute to its performance and durability.Maintaining the health of PCS poses chal...The operational and regional conditions to which the prestressed concrete sleeper(PCS)is subjected in a railway track significantly contribute to its performance and durability.Maintaining the health of PCS poses challenges,and one of these issues involves the potential occurrence of longitudinal cracks in reinforcing bars,which can be caused by various constructional,functional,and environmental factors.Longitudinal cracks in PCS compromise the structural performance,resulting in a reduced capacity to withstand the loads exerted by moving vehicles.The current evaluations not only fail to yield a precise parameter for estimating the behavior and response of the PCS,but they also overlook the specific conditions of the PCS,such as prestressing,and only provide limited information regarding existing damage.Balancing the need for accurate evaluation with consideration of costs and resources,and making informed decisions about maintenance and track performance enhancement,has become a multifaceted challenge in ensuring a robust PCS assessment.This research introduces a novel methodology to improve the evaluation of mechanical and geometrical parameters of PCS over their operational lifespan.The objective is to enhance the accuracy of PCS performance estimation by concentrating on detecting longitudinal cracks.The suggested approach seamlessly integrates model updating methods and the finite element(FE)approach to achieve an accurate and timely assessment of PCS conditions.This comprehensive examination scrutinizes the methodology by applying artificial cracks to the PCS.In addition to introducing this assessment approach,a detailed examination is conducted on a laboratory-simulated PCS featuring various combinations of longitudinal cracks measuring 40,80,and 120 cm in length.This systematic and rigorous approach ensures the reliability and robustness of the methodology.Ultimately,the parameters of cross-sectional area,moment of inertia,and modulus of elasticity,which significantly impact the performance of this sleeper,are explored and demonstrated through functional methodologies.The findings suggest that assessing and addressing damage should be conducted through a comprehensive and integrated procedure,taking into account the actual conditions of the PCS.Longitudinal cracks lead to a substantial decrease in the performance of these components in railway tracks.By applying the proposed methods,it is anticipated that the evaluation error for these components will be reduced by approximately 30%compared to visual inspections,particularly in predicting the extent of damage for cracks measuring up to 120 cm.This research has the potential to significantly enhance the evaluation of PCS performance and mitigate the impact of longitudinal cracks on the safety and longevity of ballasted railway tracks in desert areas.展开更多
BACKGROUND The coronavirus disease 2019(COVID-19)pandemic has disproportionately impacted individuals with type 2 diabetes mellitus(T2DM),increasing their risk of severe illness and mortality.Vaccination has been a cr...BACKGROUND The coronavirus disease 2019(COVID-19)pandemic has disproportionately impacted individuals with type 2 diabetes mellitus(T2DM),increasing their risk of severe illness and mortality.Vaccination has been a crucial intervention in mitigating these risks.However,the metabolic effects of COVID-19 vaccination,particularly the Johnson&Johnson(J&J)vaccine,in diabetic populations remain inadequately explored.This study investigated the longitudinal effects of the J&J vaccine on lipid and eicosanoid biomarkers to assess its metabolic safety and potential cardiovascular benefits.AIM To evaluate the long-term impact of the J&J COVID-19 vaccine on lipid and eicosanoid biomarkers in Ethiopian patients with T2DM.METHODS This prospective cohort study was conducted at Adama Hospital Medical College(Oromia,Ethiopia)from May 2023 to June 2024.A total of 224 T2DM patients(57 vaccinated,167 unvaccinated)were monitored for 1 year.Biomarkers including triglycerides(TGs),high-density lipoprotein(HDL),total cholesterol(TC),pro-staglandins(PGs),and thromboxanes(TXs)were measured at baseline and at 3 months,6 months,9 months,and 1 year post-vaccination.Statistical analyses included Generalized Estimating Equations to assess longitudinal biomarker changes.RESULTS TG and PG levels remained stable across all time points.HDL levels showed a temporary decline at 3 months(mean difference[MD]=-4.33;P<0.001)and 6 months(MD=-2.62;P<0.001)but recovered by 9 months(MD=2.09;P=0.001)and 1 year(MD=2.38;P<0.001).TC exhibited a significant decrease at 3 months(MD=-16.44,P=0.001)before stabilizing.TX levels showed a consistent decline across all follow-ups(e.g.,1 year:MD=-0.08;P=0.036),suggesting a reduced thrombotic risk.Correlation analysis indicated significant interrelations among biomarkers,emphasizing their roles in metabolic and inflammatory pathways.CONCLUSION The J&J COVID-19 vaccine exhibited metabolic safety in patients with T2DM,with transient HDL and TC reductions that later stabilized and a sustained TX decline,suggesting potential cardiovascular benefits.Further studies are needed to explore long-term immunometabolic effects on high-risk populations.展开更多
To explore and evaluate the longitudinal utilization degree of marine shale gas horizontal wells in southern Sichuan Basin(hereinafter referred to as“southern Sichuan”),focusing on the shale of Wufeng formation-Long...To explore and evaluate the longitudinal utilization degree of marine shale gas horizontal wells in southern Sichuan Basin(hereinafter referred to as“southern Sichuan”),focusing on the shale of Wufeng formation-Longyi1 sub-member in the deep Z block.By using the data from core experiments,well logging,and fracture height detection,a systematic analysis from the perspectives of reservoir distribution,longitudinal utilization height of hydraulic fractures,and longitudinal utilization degree of horizontal wells was conducted.The research results show that:(1)The overall reservoir conditions of theWufeng formation-Longyi1 sub-member in the study area are relatively favorable,although the quality of Type I reservoir varies significantly among different well blocks;(2)The proppant tracer fracture height detection results show that fractures tend to extend upwards,the average total fracture height of fracture extend is 12.7 m,with the average upward extension height is 2.5 times the downward extension height;(3)The combination of fracture height and gas well productivity analysis suggests that targeting sub-layer 1 as the horizontal well target can achieve full production of the continuous thickness of Type I reservoir in Z2 well block,whereas in Z1 well block,due to the significant proportion of the Wufeng formation in the continuous thickness of Type I reservoir,in the areas where the continuous thickness of Type I reservoir in Wufeng formation to middle sub-layer 1 is greater than 4 m,horizontal wells cannot achieve full longitudinal utilization of the continuous thickness in top-quality Type I reservoir.The conclusion is that due to the limitations of longitudinal utilization height by artificial fracture networks and the variability in the distribution of continuous thickness of Type I reservoir,Z1 well block can continue to conduct horizontal well target tests and differentiated fracturing designs to further enhance the longitudinal utilization degree of the top-quality Type I reservoir.展开更多
There is no way around it.Regular physical activity(PA)and a high-quality diet are essential to promoting good health and prolonging life in middle-aged and older adults.In the November 2024 Issue of the Journal of Sp...There is no way around it.Regular physical activity(PA)and a high-quality diet are essential to promoting good health and prolonging life in middle-aged and older adults.In the November 2024 Issue of the Journal of Sport and Health Science,Ding et al.展开更多
The transverse incision with longitudinal ligation(TILL)procedure is a new method for treating circumferential prolapsed hemorrhoids.A study by Song et al found TILL to be better than the traditional Milligan-Morgan h...The transverse incision with longitudinal ligation(TILL)procedure is a new method for treating circumferential prolapsed hemorrhoids.A study by Song et al found TILL to be better than the traditional Milligan-Morgan hemorrhoidectomy for short-term results,showing less pain,quicker healing,and lower risk of anal stenosis.TILL reduces tissue tension and controls blood supply,allowing effective removal of diseased tissue while maintaining anal function and structure.However,the study's limitations,including its retrospective,single-center design,small sample size,and short follow-up,restrict the findings'generalizability and ability to assess long-term outcomes like recurrence.Larger,multicenter trials are needed for a thorough evaluation and wider clinical adoption of TILL.展开更多
This prospective study aimed to investigate the associations of untreated cholesterol levels and their longitudinal changes,especially low levels,with all-cause and cause-specific mortality in different populations.Pa...This prospective study aimed to investigate the associations of untreated cholesterol levels and their longitudinal changes,especially low levels,with all-cause and cause-specific mortality in different populations.Participants were drawn from two Chinese cohorts and the UK Biobank,excluding those with lipid-lowering medications,coronary heart disease(CHD),stroke,cancer,clinically diagnosed chronic obstructive pulmonary disease,low body mass index(<18.5 kg·m^(-2))at baseline,and deaths within the first two years to minimize reverse causality.Individual cholesterol changes were assessed in a subset who attended the resurvey after over four years.Mortality data were linked to registries,and risks were estimated using Cox proportional hazards models.A total of 163115 Chinese and 317305 UK adults were included(mean age,49-61 years),with 43%,81%,and 44%males in Dongfeng-Tongji,Kailuan,and UK Biobank cohorts,respectively.During a median follow-up of 9.7-12.9 years,9553 and 15760 deaths were documented in the Chinese cohorts and UK Biobank,respectively.After multivariate adjustments,nonlinear relationships were observed between total cholesterol(TC),low-density lipoprotein cholesterol(LDL-C),and non-high-density lipoprotein cholesterol(non-HDL-C)levels and mortality.In both populations,high cholesterol was primarily associated with CHD mortality,while low cholesterol associated with all-cause and cancer mortality(Pnonlinear≤0.0161).The optimal levels for all-cause mortality risk in Chinese adults(TC:200 mg·dL^(-1);LDL-C:130 mg·dL^(-1);non-HDL-C:155 mg·dL^(-1))were lower than those in the UK Biobank but consistent with guideline recommendation.Additionally,decreasing cholesterol levels over four years were associated with higher all-cause and cancer mortality in the Chinese cohorts(P_(nonlinear)≤0.0100).Participants with low TC,LDL-C,or non-HDL-C levels at both baseline and resurvey experienced elevated all-cause mortality risks in both populations,as did those with low/medium baseline levels and>20%reductions over time in Chinese adults.In conclusion,higher TC,LDL-C,and non-HDL-C levels are associated with elevated CHD mortality.Importantly,low and/or longitudinally decreasing cholesterol levels are robustly associated with increased all-cause and cancer mortality,potentially serving as markers of premature death.Regular cholesterol monitoring,with attention to both high and low levels,is recommended to inform guideline updates and clinical strategies.展开更多
To investigate the influence of different longitudinal constraint systems on the longitudinal displacement at the girder ends of a three-tower suspension bridge,this study takes the Cangrong Xunjiang Bridge as an engi...To investigate the influence of different longitudinal constraint systems on the longitudinal displacement at the girder ends of a three-tower suspension bridge,this study takes the Cangrong Xunjiang Bridge as an engineering case for finite element analysis.This bridge employs an unprecedented tower-girder constraintmethod,with all vertical supports placed at the transition piers at both ends.This paper aims to study the characteristics of longitudinal displacement control at the girder ends under this novel structure,relying on finite element(FE)analysis.Initially,based on the Weigh In Motion(WIM)data,a random vehicle load model is generated and applied to the finite elementmodel.Several longitudinal constraint systems are proposed,and their effects on the structural response of the bridge are compared.The most reasonable system,balancing girder-end displacement and transitional pier stress,is selected.Subsequently,the study examines the impact of different viscous damper parameters on key structural response indicators,including cumulative longitudinal displacement at the girder ends,maximum longitudinal displacement at the girder ends,cumulative longitudinal displacement at the pier tops,maximum longitudinal displacement at the pier tops,longitudinal acceleration at the pier tops,and maximum bending moment at the pier bottoms.Finally,the coefficient of variation(CV)-TOPSIS method is used to optimize the viscous damper parameters for multiple objectives.The results show that adding viscous dampers at the side towers,in addition to the existing longitudinal limit bearings at the central tower,can most effectively reduce the response of structural indicators.The changes in these indicators are not entirely consistent with variations in damping coefficient and velocity exponent.The damper parameters significantly influence cumulative longitudinal displacement at the girder ends,cumulative longitudinal displacement at the pier tops,and maximum bending moments at the pier bottoms.The optimal damper parameters are found to be a damping coefficient of 5000 kN/(m/s)0.2 and a velocity exponent of 0.2.展开更多
Background It remains unclear whether sleep duration and physical activity(PA)trajectories in middle-aged and older adults are associated with different risks of cardiovascular diseases(CVDs).This study aimed to explo...Background It remains unclear whether sleep duration and physical activity(PA)trajectories in middle-aged and older adults are associated with different risks of cardiovascular diseases(CVDs).This study aimed to explore the trajectories of total sleep duration and PA among middle-aged and older Chinese adults and their impact on CVD risk.Methods This study was based on the China Health and Retirement Longitudinal Study.12009 adults aged 45 years and older from five waves were included.CVD events were measured by self-reports of heart disease and stroke.We first used groupbased trajectory modeling to identify total sleep duration and PA trajectories from 2011 to 2020,and then employed logistic regression models to analyze their risk for CVD.Results We identified three sleep duration and PA trajectories.The risk of heart disease increased by 33%(OR=1.31,95%CI:1.12-1.53)for the short sleep duration trajectory(vs.moderate sleep duration trajectory),by 40%(OR=1.40,95%CI:1.06-1.84)for the high decreasing PA trajectory,and by 20%(OR=1.20,95%CI:1.01-1.42)for the low stable PA trajectory(vs.high stable PA trajectory),respectively.Similar results for stroke and CVD as the outcomes were also observed,but the higher risk of stroke in the high decreasing PA trajectory group was not statistically significant.The joint effects of sleep and PA showed lower risks of heart disease and stroke in trajectories with moderate or long sleep duration and high stable PA compared with short sleep duration and a low stable PA trajectory.Conclusions Short total sleep duration,high decreasing PA,and low stable PA trajectories could increase the risk of CVDs among middle-aged and older adults.Long-term moderate to long total sleep durations and high stable PA trajectories might be optimal for preventing CVDs.展开更多
Objectives Few studies have investigated longitudinal associations of loneliness with health outcomes in Africa.This study aimed to assess the longitudinal associations between loneliness and mental and physical healt...Objectives Few studies have investigated longitudinal associations of loneliness with health outcomes in Africa.This study aimed to assess the longitudinal associations between loneliness and mental and physical health among aging adults in South Africa.Methods Data from the 7-year longitudinal Health and Ageing in Africa(HAALSI)study conducted in South Africa were used in the analysis(analytic sample:n=3707,aged 40 years and older).Loneliness was measured with one question.Longitudinal relationships between loneliness and each health outcome were estimated using Generalized Estimating Equations analysis(GEE),hazard ratios(HRs)(95%CI)were used to determine the relationship between loneliness and 7-year mortality in the entire sample,and correlations between incident health outcomes and loneliness were evaluated using logistic regressions.Results The prevalence of loneliness was 12.1%in 2015,16.9%in 2019,and 16.3%in 2022.Multivariable analysis showed that loneliness was positively associated with the prevalence and/or incidence of four poor mental health indicators(e.g.,poor sleep quality,AOR=1.53,95%CI:1.30–1.80),four physical ill-health indicators(e.g.,incident kidney disease,AOR=2.50,95%CI:1.41–4.42),mortality(Hazard Ratio=1.20,95%CI=1.04–1.39),and three poor behavioral health indicators(e.g.,current tobacco use,AOR=1.21,95%CI=1.04–1.42).Conclusion The study discovered that several outcomes related to mental,physical,and behavioral health were associated with loneliness.Enhancing the detection and management of loneliness could lower mental and physical illness in aging adults in South Africa.展开更多
In the health field,longitudinal studies involve the recording of clinical observations of the same sample of pa-tients over successive periods,referred to as waves.This type of database serves as a valuable source of...In the health field,longitudinal studies involve the recording of clinical observations of the same sample of pa-tients over successive periods,referred to as waves.This type of database serves as a valuable source of infor-mation and insights,particularly when examining the temporal aspect,allowing the extraction of relevant and non-obvious knowledge.The triadic concept analysis theory has been proposed to describe the ternary re-lationships between objects,attributes,and conditions.In this study,we present a methodology for exploring longitudinal health databases using both the triadic theory and triadic rules,which are similar to association rules but incorporate temporal relations.Through four case studies,we demonstrate the potential of applying triadic analysis to longitudinal databases to identify risk patterns,enhance decision-making processes,and deepen our understanding of temporal dynamics.These findings suggest a promising approach for describing longitudinal databases and obtaining insights to improve clinical decision-support systems for disease treatment.展开更多
For the longitudinal midcourse guidance problem of a cruise-glide integrated hypersonic vehicle(CGHV),an analytical method based on optimal control theory is proposed.This method constructs a guidance dynamics model f...For the longitudinal midcourse guidance problem of a cruise-glide integrated hypersonic vehicle(CGHV),an analytical method based on optimal control theory is proposed.This method constructs a guidance dynamics model for such vehicles,using aerodynamic load as the control variable,and introduces a framework for solving the guidance laws.This framework unifies the design process of guidance laws for both the glide and cruise phases.By decomposing the longitudinal guidance task into position control and velocity control,and minimizing energy consumption as the objective function,the method provides an analytical solution for velocity control load through the calculation of costate variables.This approach requires only the current state and terminal state parameters to determine the guidance law solution.Furthermore,by transforming path constraints into aerodynamic load constraints and solving backwards to obtain the angle of attack,bank angle,and throttle setting,this method ensures a smooth transition from the glide phase to the cruise phase,guaranteeing the successful completion of the guidance task.Finally,the effectiveness and practicality of the proposed method are validated through case simulations and analysis.展开更多
This longitudinal study examined the association between parental autonomy support and school-aged children’s adjustment across four major domains of school functioning,as well as the mediating role of children’s ex...This longitudinal study examined the association between parental autonomy support and school-aged children’s adjustment across four major domains of school functioning,as well as the mediating role of children’s executive function.Participants were 476 school-aged children(girl:49.2%,M_(age)=10.49 years,SD=1.32 years),who completed the Psychological Autonomy Support Scale,the Behavior Rating Inventory of Executive Function–2,and the Primary School Students’Psychological Suzhi Scale at baseline and at two subsequent follow-up assessments.Results from unconditional latent growth curve models and structural equation modeling indicated that paternal autonomy support was a significant predictor of children’s adjustment across all four school domains.In contrast,maternal autonomy support was significantly associated only with interpersonal adjustment.Both the intercept(initial level)and slope(rate of change)of children’s executive function significantly predicted their adjustment in all four domains.Notably,the initial level of executive function fully mediated the association between paternal autonomy support and school adjustment,whereas the rate of change in executive function did not serve as a significant mediator.Thesefindings underscore the importance of promoting parental autonomy-supportive behaviors-particularly among fathers-as a means to enhance children’s executive functioning and,consequently,their school adjustment.展开更多
In engineering practice,there are many factors causing the vibration to which rods are usually subjected.Generally,the vibration of elastic rods motivated by determined vibration excitations can be controlled effectiv...In engineering practice,there are many factors causing the vibration to which rods are usually subjected.Generally,the vibration of elastic rods motivated by determined vibration excitations can be controlled effectively.However,the working frequency of vibration excitation may vary due to environmental changes,the working conditions of equipment,and other factors.Consequently,it remains a challenge to restrict the longitudinal vibration of elastic rods within a wide frequency band.In order to meet the relevant engineering requirements and address the existing limitations,the longitudinal vibration control of an elastic rod within a wide frequency band is explored in this study through an adjustable stiffness internal support.To achieve this purpose,the variable stiffness longitudinal vibration control theory of the elastic rod is validated.The model of an adjustable stiffness internal support is designed,constructed,and tested,demonstrating that the stiffness coefficients of the adjustable stiffness internal support can be effectively controlled.Through the adjustable stiffness internal support,the experiment on longitudinal vibration control of the elastic rod is designed and performed.It leads to the conclusion that the adjustable stiffness internal support within the adjustable working region is effective in restricting the longitudinal vibration within a wide frequency band of the elastic rod.Furthermore,the existence of the adjustable working region in the experiment demonstrates the effectiveness of the adjustable stiffness internal support intended for the variable stiffness longitudinal vibration control of an elastic rod.To sum up,this study provides insights into an adjustable stiffness mechanism for applying the theory of variable stiffness longitudinal vibration control on an elastic rod in engineering practice.展开更多
BACKGROUND Thoracic ossification of the posterior longitudinal ligament(T-OPLL)is caused by the ossified posterior longitudinal ligament occupying space in the spinal canal,which causes compression of the thoracic spi...BACKGROUND Thoracic ossification of the posterior longitudinal ligament(T-OPLL)is caused by the ossified posterior longitudinal ligament occupying space in the spinal canal,which causes compression of the thoracic spinal cord.Surgical treatment is difficult,risky and complicated;thus,clinical treatment is difficult at present.CASE SUMMARY A case of severe multi-segmental T-OPLL treated with thoracic anterior controllable antedisplacement fusion(TACAF)is reported,including the surgical procedures and analysis of the clinical data.The modified-Japanese Orthopaedic Association score in this patient was 4 before surgery,and it was raised to 9 after the operation.The symptoms of spinal canal compression were subsequently relieved.Three months after surgery,digital radiography showed good healing and recovery of limb sensory function.CONCLUSION This case report suggests that TACAF is feasible for the treatment of long-segment T-OPLL,and has the advantages of low risk and reduced trauma.However,this operation still needs to be verified by clinical research with a larger sample size.展开更多
基金support from the National Natural Science Foundation of China(No.12002386).
文摘Self-excited longitudinal combustion instabilities were investigated in a hypergolic liquid bipropellant combustor, which applied single dual-swirl coaxial injector. Hot-fire tests were conducted for four different injector geometries, while extensive tests on injection conditions were carried out for each injector geometry. The synchronous measurement of the pressure and heat release rate was applied, successfully capturing the process of the pressure and heat release rate enhanced coupling and developing into in-phase oscillation. By calculating Rayleigh index at the head and middle section of the chamber, it is shown that Rayleigh index of the middle section is even higher than that of the head, indicating a long heat release zone. When the combustion instability occurs, the pressure in propellant manifolds also oscillates with the same frequency and lags behind the oscillation in the combustor. Compared to the oscillation in the outer injector manifold, the oscillation in the inner injector manifold shows a higher correlation with that in the chamber in amplitude and phase. Based on numerical simulations of the multiphase cold flow inside the injector and combustion process in the chamber, it is found that injector geometries affect longitudinal combustion instability by changing spray cone angle. The spray with small cone angle is more sensitive to the modulation of longitudinal pressure wave in combustion simulations, which is more likely to excite the longitudinal combustion instability. Meanwhile, the combustion instability may be related to the pulsating coherent structure generated by the spray fluctuation, which is determined by injection conditions. Besides, a positive feedback closed-loop system associated with the active fluctuation and passive oscillation of the spray is believed to excite and sustain the longitudinal combustion instability.
文摘BACKGROUND Dyslipidemia was strongly linked to stroke,however the relationship between dyslipidemia and its components and ischemic stroke remained unexplained.AIM To investigate the link between longitudinal changes in lipid profiles and dyslipidemia and ischemic stroke in a hypertensive population.METHODS Between 2013 and 2014,6094 hypertension individuals were included in this,and ischemic stroke cases were documented to the end of 2018.Longitudinal changes of lipid were stratified into four groups:(1)Normal was transformed into normal group;(2)Abnormal was transformed into normal group;(3)Normal was transformed into abnormal group;and(4)Abnormal was transformed into abnormal group.To examine the link between longitudinal changes in dyslipidemia along with its components and the risk of ischemic stroke,we utilized multivariate Cox proportional hazards models with hazard ratio(HR)and 95%CI.RESULTS The average age of the participants was 62.32 years±13.00 years,with 329 women making up 54.0%of the sample.Over the course of a mean follow-up of 4.8 years,143 ischemic strokes happened.When normal was transformed into normal group was used as a reference,after full adjustments,the HR for dyslipidemia and ischemic stroke among abnormal was transformed into normal group,normal was transformed into abnormal group and abnormal was transformed into abnormal Wei CC et al.Dyslipidemia changed and ischemic stroke WJCC https://www.wjgnet.com 2 February 6,2025 Volume 13 Issue 4 group were 1.089(95%CI:0.598-1.982;P=0.779),2.369(95%CI:1.424-3.941;P<0.001)and 1.448(95%CI:1.002-2.298;P=0.047)(P for trend was 0.233),respectively.CONCLUSION In individuals with hypertension,longitudinal shifts from normal to abnormal in dyslipidemia-particularly in total and low-density lipoprotein cholesterol-were significantly associated with the risk of ischemic stroke.
基金Supported by the Humanities and Social Sciences Youth Foundation of Ministry of Education of China Project,No.22YJC190023.
文摘BACKGROUND Peer bullying victimization(PBV)is a significant public health issue that adolescents often face,with approximately one-third having experienced PBV.Understanding its interrelationships with mental health problems is crucial for effective intervention.This study aims to examine the longitudinal relationships between internalizing problems(depression and anxiety),externalizing problems(aggression),and PBV among middle school students using cross-lagged panel network analysis.AIM To examine the longitudinal relationships between internalizing problems(depression and anxiety),externalizing problems(aggression),and PBV among middle school students using cross-lagged panel network analysis.METHODS A total of 1260 middle school students(54.6%male)participated in this study.Data were collected at two time points(time 1 and time 2)using self-report questionnaires to assess PBV,depression,anxiety,and aggression.Cross-lagged panel network analysis was applied to examine the bi-directional relationships between these variables over time.RESULTS Depression,particularly a“sad mood,”was the most significant predictor of both PBV and aggression.Cyberbullying victimization also emerged as a key factor influencing depression and anxiety.While anxiety had weaker and less consistent effects on PBV,aggression was predominantly influenced by depressive symptoms and sleep disturbances.The analysis also identified key symptoms,such as a“sad mood”and sleep disturbances,as crucial targets for intervention to mitigate the cycle of PBV,depression,anxiety,and aggression.CONCLUSION This study provides important insights for bullying victimization prevention and intervention strategies:(1)Early identification and intervention targeting depression,particularly a“sad mood,”and sleep disturbances;(2)The importance of addressing cyberbullying as a distinct factor influencing mental health;and(3)The need for comprehensive,longitudinal approaches to understanding and intervening in the interconnected mental health issues among adolescents.
文摘Point-of-care ultrasound(POCUS) is recognized as a valuable diagnostic tool,especially in resourcelimited settings(RLS).POCUS provides rapid diagnostic information that enables health professionals to make critical decisions at the bedside.^([1]) Despite the welldocumented benefits of POCUS,access to longitudinal,comprehensive training programs and a lack of trainee feedback are barriers to the widespread use of this technology in such settings.^([2])
文摘The longitudinal ventilation strategy is commonly used for road tunnels in urban environment in Sweden.This is partly due to how tunnels in urban environment was planned and designed before the EU Directive[1](2004/54/EC)came in place.Even in new tunnels both to practical and economic reasons the use of longitudinal ventilation has been an outspoken demand from the Swedish road authority,SRA.Swedish law[2]requires that a risk analysis is carried out to demonstrate that an acceptable level of risk is achieved in the tunnels with longitudinal ventilation if there is a risk of queues.Otherwise transverse or semi-transverse ventilation strategy shall be used.During recent development,or a late awakening,it is clear that dense populated areas in Sweden will experience queues.This threatens the foundation of the Swedish modern tunnel safety concept which calls for enhancement.This paper presents the risk-reducing effect of three alternative strategies,enhancements package,focusing on evacuation safety for road users.It is a combination of traffic management,fixed firefighting systems,reduced distance between escape routes and regulation of traffic with dangerous goods.In addition,it provides a comprehensive review of safety system details,combined with a longitudinal ventilation concept.
基金National Key R&D Program of China,No.2022YFC3203903National Natural Science Foundation of China,No.42371010,No.41971004。
文摘How the strong segmentation of cascade reservoir dams and the spatiotemporal changes of sediment retention volume affect the river morphology adjustment in the reservoir area is a scientific issue worthy of exploration.This study aims to reveal the adjustment mechanism of the thalweg longitudinal profile of cascade reservoirs.This study focuses on the Xiangjiaba and Xiluodu reservoirs located in the lower reaches of the Jinsha River.Utilizing multi-period observational data of thalweg elevation in reservoir reaches both before and after dam construction,the research employs statistical,geomorphological,and sedimentological methodologies to analyze variation characteristics in the measured curves,trend curves,and theoretical fitting curves of the thalweg longitudinal profile.The investigation ultimately reveals two distinct adjustment patterns in the longitudinal profiles of these cascade reservoirs:the concave curve type and the convex curve type.The former is characterized by weak riverbed scouring and silting changed to rapid aggradation in the upstream section of the reservoir area after dam closure,then changed to slow aggradation in the whole reservoir area,which is the common feature of reservoirs that were built earlier and are relatively located in the downstream(such as the Xiangjiaba Reservoir).The latter is characterized by a straight line or concave curve type with weak riverbed scouring and silting before the dam closure changed to a convex curve type with strong siltation after dam closure,which is the characteristic of reservoirs that were built later and are relatively located in the upstream(such as the Xiluodu Reservoir).The adjustment of the cascade reservoir longitudinal profile is controlled by the spatiotemporal changes of the sediment deposition volume and sedimentation rate in the reservoir area,and the alternating changes of the hydrodynamic gradient and regulation mode affect the spatial heterogeneity of the sedimentation rate.The research results are helpful for understanding the adjustment mechanism of the cascade reservoir longitudinal profile in similar areas and have a guiding role in predicting the adjustment trend of the cascade reservoir longitudinal profile without observation data.
文摘The operational and regional conditions to which the prestressed concrete sleeper(PCS)is subjected in a railway track significantly contribute to its performance and durability.Maintaining the health of PCS poses challenges,and one of these issues involves the potential occurrence of longitudinal cracks in reinforcing bars,which can be caused by various constructional,functional,and environmental factors.Longitudinal cracks in PCS compromise the structural performance,resulting in a reduced capacity to withstand the loads exerted by moving vehicles.The current evaluations not only fail to yield a precise parameter for estimating the behavior and response of the PCS,but they also overlook the specific conditions of the PCS,such as prestressing,and only provide limited information regarding existing damage.Balancing the need for accurate evaluation with consideration of costs and resources,and making informed decisions about maintenance and track performance enhancement,has become a multifaceted challenge in ensuring a robust PCS assessment.This research introduces a novel methodology to improve the evaluation of mechanical and geometrical parameters of PCS over their operational lifespan.The objective is to enhance the accuracy of PCS performance estimation by concentrating on detecting longitudinal cracks.The suggested approach seamlessly integrates model updating methods and the finite element(FE)approach to achieve an accurate and timely assessment of PCS conditions.This comprehensive examination scrutinizes the methodology by applying artificial cracks to the PCS.In addition to introducing this assessment approach,a detailed examination is conducted on a laboratory-simulated PCS featuring various combinations of longitudinal cracks measuring 40,80,and 120 cm in length.This systematic and rigorous approach ensures the reliability and robustness of the methodology.Ultimately,the parameters of cross-sectional area,moment of inertia,and modulus of elasticity,which significantly impact the performance of this sleeper,are explored and demonstrated through functional methodologies.The findings suggest that assessing and addressing damage should be conducted through a comprehensive and integrated procedure,taking into account the actual conditions of the PCS.Longitudinal cracks lead to a substantial decrease in the performance of these components in railway tracks.By applying the proposed methods,it is anticipated that the evaluation error for these components will be reduced by approximately 30%compared to visual inspections,particularly in predicting the extent of damage for cracks measuring up to 120 cm.This research has the potential to significantly enhance the evaluation of PCS performance and mitigate the impact of longitudinal cracks on the safety and longevity of ballasted railway tracks in desert areas.
文摘BACKGROUND The coronavirus disease 2019(COVID-19)pandemic has disproportionately impacted individuals with type 2 diabetes mellitus(T2DM),increasing their risk of severe illness and mortality.Vaccination has been a crucial intervention in mitigating these risks.However,the metabolic effects of COVID-19 vaccination,particularly the Johnson&Johnson(J&J)vaccine,in diabetic populations remain inadequately explored.This study investigated the longitudinal effects of the J&J vaccine on lipid and eicosanoid biomarkers to assess its metabolic safety and potential cardiovascular benefits.AIM To evaluate the long-term impact of the J&J COVID-19 vaccine on lipid and eicosanoid biomarkers in Ethiopian patients with T2DM.METHODS This prospective cohort study was conducted at Adama Hospital Medical College(Oromia,Ethiopia)from May 2023 to June 2024.A total of 224 T2DM patients(57 vaccinated,167 unvaccinated)were monitored for 1 year.Biomarkers including triglycerides(TGs),high-density lipoprotein(HDL),total cholesterol(TC),pro-staglandins(PGs),and thromboxanes(TXs)were measured at baseline and at 3 months,6 months,9 months,and 1 year post-vaccination.Statistical analyses included Generalized Estimating Equations to assess longitudinal biomarker changes.RESULTS TG and PG levels remained stable across all time points.HDL levels showed a temporary decline at 3 months(mean difference[MD]=-4.33;P<0.001)and 6 months(MD=-2.62;P<0.001)but recovered by 9 months(MD=2.09;P=0.001)and 1 year(MD=2.38;P<0.001).TC exhibited a significant decrease at 3 months(MD=-16.44,P=0.001)before stabilizing.TX levels showed a consistent decline across all follow-ups(e.g.,1 year:MD=-0.08;P=0.036),suggesting a reduced thrombotic risk.Correlation analysis indicated significant interrelations among biomarkers,emphasizing their roles in metabolic and inflammatory pathways.CONCLUSION The J&J COVID-19 vaccine exhibited metabolic safety in patients with T2DM,with transient HDL and TC reductions that later stabilized and a sustained TX decline,suggesting potential cardiovascular benefits.Further studies are needed to explore long-term immunometabolic effects on high-risk populations.
文摘To explore and evaluate the longitudinal utilization degree of marine shale gas horizontal wells in southern Sichuan Basin(hereinafter referred to as“southern Sichuan”),focusing on the shale of Wufeng formation-Longyi1 sub-member in the deep Z block.By using the data from core experiments,well logging,and fracture height detection,a systematic analysis from the perspectives of reservoir distribution,longitudinal utilization height of hydraulic fractures,and longitudinal utilization degree of horizontal wells was conducted.The research results show that:(1)The overall reservoir conditions of theWufeng formation-Longyi1 sub-member in the study area are relatively favorable,although the quality of Type I reservoir varies significantly among different well blocks;(2)The proppant tracer fracture height detection results show that fractures tend to extend upwards,the average total fracture height of fracture extend is 12.7 m,with the average upward extension height is 2.5 times the downward extension height;(3)The combination of fracture height and gas well productivity analysis suggests that targeting sub-layer 1 as the horizontal well target can achieve full production of the continuous thickness of Type I reservoir in Z2 well block,whereas in Z1 well block,due to the significant proportion of the Wufeng formation in the continuous thickness of Type I reservoir,in the areas where the continuous thickness of Type I reservoir in Wufeng formation to middle sub-layer 1 is greater than 4 m,horizontal wells cannot achieve full longitudinal utilization of the continuous thickness in top-quality Type I reservoir.The conclusion is that due to the limitations of longitudinal utilization height by artificial fracture networks and the variability in the distribution of continuous thickness of Type I reservoir,Z1 well block can continue to conduct horizontal well target tests and differentiated fracturing designs to further enhance the longitudinal utilization degree of the top-quality Type I reservoir.
文摘There is no way around it.Regular physical activity(PA)and a high-quality diet are essential to promoting good health and prolonging life in middle-aged and older adults.In the November 2024 Issue of the Journal of Sport and Health Science,Ding et al.
文摘The transverse incision with longitudinal ligation(TILL)procedure is a new method for treating circumferential prolapsed hemorrhoids.A study by Song et al found TILL to be better than the traditional Milligan-Morgan hemorrhoidectomy for short-term results,showing less pain,quicker healing,and lower risk of anal stenosis.TILL reduces tissue tension and controls blood supply,allowing effective removal of diseased tissue while maintaining anal function and structure.However,the study's limitations,including its retrospective,single-center design,small sample size,and short follow-up,restrict the findings'generalizability and ability to assess long-term outcomes like recurrence.Larger,multicenter trials are needed for a thorough evaluation and wider clinical adoption of TILL.
基金supported by the National Natural Science Foundation of China(82021005,82192903,81930092)the Chief Scientist Research Project of Hubei Shizhen Laboratory(HSL2024SX0003)+1 种基金the Fundamental Research Funds for the Central Universities(2019kfyXMBZ015)the 111 Project and the Program for Changjiang Scholars and Innovative Research Team in University.
文摘This prospective study aimed to investigate the associations of untreated cholesterol levels and their longitudinal changes,especially low levels,with all-cause and cause-specific mortality in different populations.Participants were drawn from two Chinese cohorts and the UK Biobank,excluding those with lipid-lowering medications,coronary heart disease(CHD),stroke,cancer,clinically diagnosed chronic obstructive pulmonary disease,low body mass index(<18.5 kg·m^(-2))at baseline,and deaths within the first two years to minimize reverse causality.Individual cholesterol changes were assessed in a subset who attended the resurvey after over four years.Mortality data were linked to registries,and risks were estimated using Cox proportional hazards models.A total of 163115 Chinese and 317305 UK adults were included(mean age,49-61 years),with 43%,81%,and 44%males in Dongfeng-Tongji,Kailuan,and UK Biobank cohorts,respectively.During a median follow-up of 9.7-12.9 years,9553 and 15760 deaths were documented in the Chinese cohorts and UK Biobank,respectively.After multivariate adjustments,nonlinear relationships were observed between total cholesterol(TC),low-density lipoprotein cholesterol(LDL-C),and non-high-density lipoprotein cholesterol(non-HDL-C)levels and mortality.In both populations,high cholesterol was primarily associated with CHD mortality,while low cholesterol associated with all-cause and cancer mortality(Pnonlinear≤0.0161).The optimal levels for all-cause mortality risk in Chinese adults(TC:200 mg·dL^(-1);LDL-C:130 mg·dL^(-1);non-HDL-C:155 mg·dL^(-1))were lower than those in the UK Biobank but consistent with guideline recommendation.Additionally,decreasing cholesterol levels over four years were associated with higher all-cause and cancer mortality in the Chinese cohorts(P_(nonlinear)≤0.0100).Participants with low TC,LDL-C,or non-HDL-C levels at both baseline and resurvey experienced elevated all-cause mortality risks in both populations,as did those with low/medium baseline levels and>20%reductions over time in Chinese adults.In conclusion,higher TC,LDL-C,and non-HDL-C levels are associated with elevated CHD mortality.Importantly,low and/or longitudinally decreasing cholesterol levels are robustly associated with increased all-cause and cancer mortality,potentially serving as markers of premature death.Regular cholesterol monitoring,with attention to both high and low levels,is recommended to inform guideline updates and clinical strategies.
基金supported by the National Key Research and Development Program of China(No.2022YFB3706704)the Academician Special Science Research Project of CCCC(No.YSZX-03-2022-01-B).
文摘To investigate the influence of different longitudinal constraint systems on the longitudinal displacement at the girder ends of a three-tower suspension bridge,this study takes the Cangrong Xunjiang Bridge as an engineering case for finite element analysis.This bridge employs an unprecedented tower-girder constraintmethod,with all vertical supports placed at the transition piers at both ends.This paper aims to study the characteristics of longitudinal displacement control at the girder ends under this novel structure,relying on finite element(FE)analysis.Initially,based on the Weigh In Motion(WIM)data,a random vehicle load model is generated and applied to the finite elementmodel.Several longitudinal constraint systems are proposed,and their effects on the structural response of the bridge are compared.The most reasonable system,balancing girder-end displacement and transitional pier stress,is selected.Subsequently,the study examines the impact of different viscous damper parameters on key structural response indicators,including cumulative longitudinal displacement at the girder ends,maximum longitudinal displacement at the girder ends,cumulative longitudinal displacement at the pier tops,maximum longitudinal displacement at the pier tops,longitudinal acceleration at the pier tops,and maximum bending moment at the pier bottoms.Finally,the coefficient of variation(CV)-TOPSIS method is used to optimize the viscous damper parameters for multiple objectives.The results show that adding viscous dampers at the side towers,in addition to the existing longitudinal limit bearings at the central tower,can most effectively reduce the response of structural indicators.The changes in these indicators are not entirely consistent with variations in damping coefficient and velocity exponent.The damper parameters significantly influence cumulative longitudinal displacement at the girder ends,cumulative longitudinal displacement at the pier tops,and maximum bending moments at the pier bottoms.The optimal damper parameters are found to be a damping coefficient of 5000 kN/(m/s)0.2 and a velocity exponent of 0.2.
基金supported by Peking University,the National Natural Science Foundation of China,the National Institute on Aging and the World Bank。
文摘Background It remains unclear whether sleep duration and physical activity(PA)trajectories in middle-aged and older adults are associated with different risks of cardiovascular diseases(CVDs).This study aimed to explore the trajectories of total sleep duration and PA among middle-aged and older Chinese adults and their impact on CVD risk.Methods This study was based on the China Health and Retirement Longitudinal Study.12009 adults aged 45 years and older from five waves were included.CVD events were measured by self-reports of heart disease and stroke.We first used groupbased trajectory modeling to identify total sleep duration and PA trajectories from 2011 to 2020,and then employed logistic regression models to analyze their risk for CVD.Results We identified three sleep duration and PA trajectories.The risk of heart disease increased by 33%(OR=1.31,95%CI:1.12-1.53)for the short sleep duration trajectory(vs.moderate sleep duration trajectory),by 40%(OR=1.40,95%CI:1.06-1.84)for the high decreasing PA trajectory,and by 20%(OR=1.20,95%CI:1.01-1.42)for the low stable PA trajectory(vs.high stable PA trajectory),respectively.Similar results for stroke and CVD as the outcomes were also observed,but the higher risk of stroke in the high decreasing PA trajectory group was not statistically significant.The joint effects of sleep and PA showed lower risks of heart disease and stroke in trajectories with moderate or long sleep duration and high stable PA compared with short sleep duration and a low stable PA trajectory.Conclusions Short total sleep duration,high decreasing PA,and low stable PA trajectories could increase the risk of CVDs among middle-aged and older adults.Long-term moderate to long total sleep durations and high stable PA trajectories might be optimal for preventing CVDs.
基金HAALSI(Health and Aging in Africa:A Longitudinal Study of an INDEPTH Community in South Africa)is sponsored by the National Institute on Aging(grant number 5P01AG041710-05)and is conducted by the Harvard Center for Population and Development Studies in Partnership with Witwatersrand UniversityThe Agincourt HDSS was supported by the Wellcome Trust,UK(058893/Z/99/A,069683/Z/02/Z,085477/Z/08/Z and085477/B/08/Z),the University of the Witwatersrand and South African Medical Research Council.
文摘Objectives Few studies have investigated longitudinal associations of loneliness with health outcomes in Africa.This study aimed to assess the longitudinal associations between loneliness and mental and physical health among aging adults in South Africa.Methods Data from the 7-year longitudinal Health and Ageing in Africa(HAALSI)study conducted in South Africa were used in the analysis(analytic sample:n=3707,aged 40 years and older).Loneliness was measured with one question.Longitudinal relationships between loneliness and each health outcome were estimated using Generalized Estimating Equations analysis(GEE),hazard ratios(HRs)(95%CI)were used to determine the relationship between loneliness and 7-year mortality in the entire sample,and correlations between incident health outcomes and loneliness were evaluated using logistic regressions.Results The prevalence of loneliness was 12.1%in 2015,16.9%in 2019,and 16.3%in 2022.Multivariable analysis showed that loneliness was positively associated with the prevalence and/or incidence of four poor mental health indicators(e.g.,poor sleep quality,AOR=1.53,95%CI:1.30–1.80),four physical ill-health indicators(e.g.,incident kidney disease,AOR=2.50,95%CI:1.41–4.42),mortality(Hazard Ratio=1.20,95%CI=1.04–1.39),and three poor behavioral health indicators(e.g.,current tobacco use,AOR=1.21,95%CI=1.04–1.42).Conclusion The study discovered that several outcomes related to mental,physical,and behavioral health were associated with loneliness.Enhancing the detection and management of loneliness could lower mental and physical illness in aging adults in South Africa.
文摘In the health field,longitudinal studies involve the recording of clinical observations of the same sample of pa-tients over successive periods,referred to as waves.This type of database serves as a valuable source of infor-mation and insights,particularly when examining the temporal aspect,allowing the extraction of relevant and non-obvious knowledge.The triadic concept analysis theory has been proposed to describe the ternary re-lationships between objects,attributes,and conditions.In this study,we present a methodology for exploring longitudinal health databases using both the triadic theory and triadic rules,which are similar to association rules but incorporate temporal relations.Through four case studies,we demonstrate the potential of applying triadic analysis to longitudinal databases to identify risk patterns,enhance decision-making processes,and deepen our understanding of temporal dynamics.These findings suggest a promising approach for describing longitudinal databases and obtaining insights to improve clinical decision-support systems for disease treatment.
基金supported by the National Natural Science Foundation of China(Grant Nos.62473374,62403487 and U2441243).
文摘For the longitudinal midcourse guidance problem of a cruise-glide integrated hypersonic vehicle(CGHV),an analytical method based on optimal control theory is proposed.This method constructs a guidance dynamics model for such vehicles,using aerodynamic load as the control variable,and introduces a framework for solving the guidance laws.This framework unifies the design process of guidance laws for both the glide and cruise phases.By decomposing the longitudinal guidance task into position control and velocity control,and minimizing energy consumption as the objective function,the method provides an analytical solution for velocity control load through the calculation of costate variables.This approach requires only the current state and terminal state parameters to determine the guidance law solution.Furthermore,by transforming path constraints into aerodynamic load constraints and solving backwards to obtain the angle of attack,bank angle,and throttle setting,this method ensures a smooth transition from the glide phase to the cruise phase,guaranteeing the successful completion of the guidance task.Finally,the effectiveness and practicality of the proposed method are validated through case simulations and analysis.
基金supported by the National Natural Science Foundation of China(CN)(Grant No.32071074).
文摘This longitudinal study examined the association between parental autonomy support and school-aged children’s adjustment across four major domains of school functioning,as well as the mediating role of children’s executive function.Participants were 476 school-aged children(girl:49.2%,M_(age)=10.49 years,SD=1.32 years),who completed the Psychological Autonomy Support Scale,the Behavior Rating Inventory of Executive Function–2,and the Primary School Students’Psychological Suzhi Scale at baseline and at two subsequent follow-up assessments.Results from unconditional latent growth curve models and structural equation modeling indicated that paternal autonomy support was a significant predictor of children’s adjustment across all four school domains.In contrast,maternal autonomy support was significantly associated only with interpersonal adjustment.Both the intercept(initial level)and slope(rate of change)of children’s executive function significantly predicted their adjustment in all four domains.Notably,the initial level of executive function fully mediated the association between paternal autonomy support and school adjustment,whereas the rate of change in executive function did not serve as a significant mediator.Thesefindings underscore the importance of promoting parental autonomy-supportive behaviors-particularly among fathers-as a means to enhance children’s executive functioning and,consequently,their school adjustment.
基金Supported by the Fundamental Research Project of SIA(Grant No.2022JC1G04)National Natural Science Foundation of China(Grant Nos.52401364 and 52205091)。
文摘In engineering practice,there are many factors causing the vibration to which rods are usually subjected.Generally,the vibration of elastic rods motivated by determined vibration excitations can be controlled effectively.However,the working frequency of vibration excitation may vary due to environmental changes,the working conditions of equipment,and other factors.Consequently,it remains a challenge to restrict the longitudinal vibration of elastic rods within a wide frequency band.In order to meet the relevant engineering requirements and address the existing limitations,the longitudinal vibration control of an elastic rod within a wide frequency band is explored in this study through an adjustable stiffness internal support.To achieve this purpose,the variable stiffness longitudinal vibration control theory of the elastic rod is validated.The model of an adjustable stiffness internal support is designed,constructed,and tested,demonstrating that the stiffness coefficients of the adjustable stiffness internal support can be effectively controlled.Through the adjustable stiffness internal support,the experiment on longitudinal vibration control of the elastic rod is designed and performed.It leads to the conclusion that the adjustable stiffness internal support within the adjustable working region is effective in restricting the longitudinal vibration within a wide frequency band of the elastic rod.Furthermore,the existence of the adjustable working region in the experiment demonstrates the effectiveness of the adjustable stiffness internal support intended for the variable stiffness longitudinal vibration control of an elastic rod.To sum up,this study provides insights into an adjustable stiffness mechanism for applying the theory of variable stiffness longitudinal vibration control on an elastic rod in engineering practice.
文摘BACKGROUND Thoracic ossification of the posterior longitudinal ligament(T-OPLL)is caused by the ossified posterior longitudinal ligament occupying space in the spinal canal,which causes compression of the thoracic spinal cord.Surgical treatment is difficult,risky and complicated;thus,clinical treatment is difficult at present.CASE SUMMARY A case of severe multi-segmental T-OPLL treated with thoracic anterior controllable antedisplacement fusion(TACAF)is reported,including the surgical procedures and analysis of the clinical data.The modified-Japanese Orthopaedic Association score in this patient was 4 before surgery,and it was raised to 9 after the operation.The symptoms of spinal canal compression were subsequently relieved.Three months after surgery,digital radiography showed good healing and recovery of limb sensory function.CONCLUSION This case report suggests that TACAF is feasible for the treatment of long-segment T-OPLL,and has the advantages of low risk and reduced trauma.However,this operation still needs to be verified by clinical research with a larger sample size.
