In this study,three specific scenarios of a novel accelerator light source mechanism called steady-state microbunching(SSMB)were studied:longitudinal weak focusing,longitudinal strong focusing,and generalized longitud...In this study,three specific scenarios of a novel accelerator light source mechanism called steady-state microbunching(SSMB)were studied:longitudinal weak focusing,longitudinal strong focusing,and generalized longitudinal strong focusing(GLSF).At present,GLSF is the most promising method for realizing high-power short-wavelength coherent radiation with mild requirements on modulation laser power.Its essence is to exploit the ultrasmall natural vertical emittance of an electron beam in a planar storage ring for efficient microbunching formation,like a partial transverse-longitudinal emittance exchange in the optical laser wavelength range.Based on an in-depth investigation of related beam physics,a solution for a GLSF SSMB storage ring that can deliver 1 kW average-power EUV light is presented.The work in this paper,such as the generalized Courant–Snyder formalism,analysis of theoretical minimum emittances,transverse-longitudinal coupling dynamics,and derivation of the bunching factor and modulation strengths for laser-induced microbunching schemes,is expected to be useful not only for the development of SSMB but also for future accelerator light sources in general that demand increasingly precise electron beam phase space manipulations.展开更多
Objective:Sepsis exhibits remarkable heterogeneity in disease progression trajectories,and accurate identificationof distinct trajectory-based phenotypes is critical for implementing personalized therapeutic strategie...Objective:Sepsis exhibits remarkable heterogeneity in disease progression trajectories,and accurate identificationof distinct trajectory-based phenotypes is critical for implementing personalized therapeutic strategies and prognostic assessment.However,trajectory clustering analysis of time-series clinical data poses substantial methodological challenges for researchers.This study provides a comprehensive tutorial framework demonstrating six trajectory modeling approaches integrated with proteomic analysis to guide researchers in identifying sepsis subtypes after laparoscopic surgery.Methods:This study employs simulated longitudinal data from 300 septic patients after laparoscopic surgery to demonstrate six trajectory modeling methods(group-based trajectory modeling,latent growth mixture modeling,latent transition analysis,time-varying effect modeling,K-means for longitudinal data,agglomerative hierarchical clustering)for identifying associations between predefinedsequential organ failure assessment trajectories and 25 proteomic biomarkers.Clustering performance was evaluated via multiple metrics,and a biomarker discovery pipeline integrating principal component analysis,random forests,feature selection,and receiver operating characteristic analysis was developed.Results:The six methods demonstrated varying performance in identifying trajectory structures,with each approach exhibiting distinct analytical characteristics.The performance metrics revealed differences across methods,which may inform context-specificmethod selection and interpretation strategies.Conclusion:This study illustrates practical implementations of trajectory modeling approaches under controlled conditions,facilitating informed method selection for clinical researchers.The inclusion of complete R code and integrated proteomics workflows offers a reproducible analytical framework connecting temporal pattern recognition to biomarker discovery.Beyond sepsis,this pipeline-oriented approach may be adapted to diverse clinical scenarios requiring longitudinal disease characterization and precision medicine applications.The comparative analysis reveals that each method has distinct strengths,providing a practical guide for clinical researchers in selecting appropriate methods based on their specificstudy goals and data characteristics.展开更多
The diversion effect caused by the linked structure in a metro tunnel with cross-passage complicates the impact of longitudinal fire source location on the smoke backflow layering behavior that has not been clarified,...The diversion effect caused by the linked structure in a metro tunnel with cross-passage complicates the impact of longitudinal fire source location on the smoke backflow layering behavior that has not been clarified,despite the fact that the scenario exists in practice.A series of laboratory-scale experiments were conducted in this study to investigate the smoke back-layering length in a model tunnel with cross-passage.The heat release rate,the velocity of longitudinal air flow,and the location of the fire source were all varied.It was found that the behavior of smoke backflow for the fire source located at the upstream of bifurcation point resembles a single-hole tunnel fire.As the fire source’s position shifts downstream from the bifurcation point,the length of smoke back-layering progressively increases.A competitive interaction exists between airflow diversion and smoke diversion during smoke backflow,significantly affecting the smoke back-layering length in the main tunnel.The dimensionless smoke back-layering length model was formulated in a tunnel featuring a cross-passage,taking into account the positions of longitudinal fire sources.The dimensionless smoke back-layering length exhibits a positive correlation with the 17/18 power of total heat release rate Q and a negative correlation with the 5/2 power of longitudinal ventilation velocity V.展开更多
This study explores the core characteristics,dynamic progression of the depression-anxiety-stress network among Chinese higher vocational college freshmen and its association with life satisfaction,and identifies key ...This study explores the core characteristics,dynamic progression of the depression-anxiety-stress network among Chinese higher vocational college freshmen and its association with life satisfaction,and identifies key nodes and critical intervention points.Participants were 295 higher vocational college freshmen(male=137;M=18.52,SD=0.69)completing two follow-up surveys(5-month interval).Measures included depression-anxiety-stress symptoms and life satisfaction,analyzed via cross-sectional and binary cross-lagged panel network analysis.The results showed that“Easily agitated”was the central node(strength=1.519,EI=1.967);“Irritable”and“Mouth Dryness”were top predictors(Out-EI=1.101,1.100),with depressive symptoms as the convergence hub.“Easily agitated”had the strongest direct negative impact on life satisfaction(cross-cluster out-predictability=−0.653).This study elucidates depression-anxietystress network mechanisms in higher vocational freshmen,providing a theoretical framework and targeted intervention guidance(e.g.,focusing on somatic and emotional nodes).展开更多
Investigating the wind-sand flow response regularity in the longitudinal slope sections of desert highways provides a scientific basis for selecting the slope of desert roads.This study uses the Tengger Desert section...Investigating the wind-sand flow response regularity in the longitudinal slope sections of desert highways provides a scientific basis for selecting the slope of desert roads.This study uses the Tengger Desert section of the Wuhai-Maqin Expressway as a case study,employing CFD numerical simulation methods to calculate and analyze the wind-sand flow field distribution characteristics in different longitudinal slope sections.The results show that:(1)Along with the direction of the incoming flow,the windward and leeward slope toes of the embankment are low-wind-speed zones,with the wind speed at the leeward slope toe being even lower.The higher the embankment,the larger the low-wind-speed zone at the windward and leeward slope toes.As the longitudinal slope increases,the extent of the lowwind-speed zone at the same location along the route also increases.(2)Along the route direction,the wind speed at the windward and leeward slope toes decreases as embankment height increases.At the embankment toe,sand particles are transported from the top to the bottom of the longitudinal slope,and the greater the longitudinal slope,the stronger the transport effect.(3)Along the route direction,the sand accumulation around the embankment gradually gathers toward the bottom of the longitudinal slope as the slope increases.When the longitudinal slope is 3%and 4%,the trend of sand accumulation moving from the windward side at the end of the route to the leeward side at the start of the route is more significant.When the longitudinal slope is less than or equal to 3%,severe sand accumulation within the embankment range is reduced by 86.4%or more compared to when the slope is 4%.(4)Under the same longitudinal slope,the higher the embankment height,the smaller its transport rate.When the embankment height is the same,the greater the longitudinal slope,the greater the embankment transport rate.展开更多
Strong seismic excitation and fault dislocation are likely to occur simultaneously in high-intensity seismic zones,causing severe damage to tunnels crossing active fault zones.This paper aims to develop a novel analyt...Strong seismic excitation and fault dislocation are likely to occur simultaneously in high-intensity seismic zones,causing severe damage to tunnels crossing active fault zones.This paper aims to develop a novel analytical solution to determine the longitudinal mechanical responses of tunnels subjected to the combined effects of seismic waves and strike-slip faulting.Adopting the elastic springbeam model,the seismic waves are modelled as shear horizontal(SH)waves and the fault dislocation follows an S-shaped pattern;the superposition principle for free-fielddisplacements caused by both effects is assumed.In addition,the transmission and reflectionof seismic waves at the fault-rock geological interface and the tangential contact conditions at the tunnel-rock interface are considered.The analytical model is validated against numerical simulations,confirmingits accuracy in calculating tunnel responses.Moreover,a parametric study is conducted to evaluate the impact of key factors,including fault displacement,fault zone width,fault dip angle,earthquake frequency,rock conditions,tunnel lining stiffness,and tangential contact conditions,on tunnel responses.Compared with each effect alone,the combined effects of seismic waves and strike-slip faulting significantlychange the tunnel deformation and internal forces,leading to increased tunnel responses,especially within the fault zone and near the fault-rock interfaces.Depending on specificparameters,tunnel responses can be classifiedinto seismic-dominated,faulting-dominated,and seismic-faulting coupled responses on the basis of the relative contributions of each effect.The proposed analytical solution can be applied to quickly predict the longitudinal mechanical behaviour of tunnels under such combined effects in engineering applications.展开更多
Objective:To preliminarily construct and apply a longitudinal trajectory model for the prognosis of intracerebral hemorrhage(ICH)based on blood urea nitrogen(BUN)characteristics.Methods:Clinical data from 320 ICH pati...Objective:To preliminarily construct and apply a longitudinal trajectory model for the prognosis of intracerebral hemorrhage(ICH)based on blood urea nitrogen(BUN)characteristics.Methods:Clinical data from 320 ICH patients admitted to our hospital between 2020 and 2024 were collected,including demographic information,National Institutes of Health Stroke Scale(NIHSS)scores at admission,dynamic changes in BUN levels during treatment,and 30-day survival outcomes.A latent class growth model(LCGM)was first used for preliminary modeling,followed by a latent growth mixture modeling(GMM)approach to determine the final model.Three classes of BUN trajectories for ICH prognosis were identified,and latent classes were established.GMM modeling was then performed on these latent classes,considering linear,quadratic,and cubic polynomial forms;six GMM models were constructed and individuals were assigned to latent trajectory groups for validation.Results:LCGM analysis ultimately identified three dynamic BUN trajectory groups:Sustained low-level group(76 cases,23.8%):BUN remained stable between 3.1-9.0 mmol/L,with the highest 30-day survival rate(98.7%).Fluctuating-declining group(222 cases,69.4%):BUN initially increased and then slowly decreased(peak at day 3:15.2 mmol/L),with a 30-day mortality of 8.1%(18/222),higher than the sustained low-level group.Sustained high-level group(22 cases,6.9%):BUN mean>9.0 mmol/L,with a 30-day mortality of 41.7%(P=0.000).GMM model fitting showed that the cubic polynomial GMM model was optimal(AIC=6754.474,BIC=6852.450,Entropy=0.905).Incorporating gender,age,and BMI as covariates revealed significant effects for gender(Estimate=0.045,-0.011,P=0.000,0.000).The AUC for predicting 30-day mortality was 0.88(sensitivity 82.8%,specificity 77.9%),which increased to 0.89 when combined with admission NIHSS scores.Conclusion:The LCGM+GMM model based on dynamic BUN trajectories effectively distinguishes prognostic subgroups in ICH patients.Patients with persistently elevated or fluctuating-rising BUN levels have a significantly higher mortality risk compared to those with sustained low levels.This model provides a new quantitative tool for early identification of high-risk patients and poor prognoses.展开更多
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
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
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
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
基金supported by the National Key Research and Development Program of China(No.2022YFA1603401)National Natural Science Foundation of China(Nos.12035010 and 12342501)+1 种基金Beijing Outstanding Young Scientist Program(No.JWZQ20240101006)the Tsinghua University Dushi Program.
文摘In this study,three specific scenarios of a novel accelerator light source mechanism called steady-state microbunching(SSMB)were studied:longitudinal weak focusing,longitudinal strong focusing,and generalized longitudinal strong focusing(GLSF).At present,GLSF is the most promising method for realizing high-power short-wavelength coherent radiation with mild requirements on modulation laser power.Its essence is to exploit the ultrasmall natural vertical emittance of an electron beam in a planar storage ring for efficient microbunching formation,like a partial transverse-longitudinal emittance exchange in the optical laser wavelength range.Based on an in-depth investigation of related beam physics,a solution for a GLSF SSMB storage ring that can deliver 1 kW average-power EUV light is presented.The work in this paper,such as the generalized Courant–Snyder formalism,analysis of theoretical minimum emittances,transverse-longitudinal coupling dynamics,and derivation of the bunching factor and modulation strengths for laser-induced microbunching schemes,is expected to be useful not only for the development of SSMB but also for future accelerator light sources in general that demand increasingly precise electron beam phase space manipulations.
基金funding from the China National Key Research and Development Program(No.2023YFC3603104)the National Natural Science Foundation of China(Nos.82472243 and 82272180)+6 种基金the Fundamental Research Funds for the Central Universities(No.226-2025-00024)the Huadong Medicine Joint Funds of the Zhejiang Provincial Natural Science Foundation of China(No.LHDMD24H150001)the Key Research&Development Project of Zhejiang Province(No.2024C03240)a collaborative scientific project co-established by the Science and Technology Department of the National Administration of Traditional Chinese Medicine and the Zhejiang Provincial Administration of Traditional Chinese Medicine(No.GZY-ZJ-KJ-24082)he General Health Science and Technology Program of Zhejiang Province(No.2024KY1099)the Project of Zhejiang University Longquan Innovation Center(No.ZJDXLQCXZCJBGS2024016)Wu Jieping Medical Foundation Special Research Grant(No.320.6750.2024-23-07).
文摘Objective:Sepsis exhibits remarkable heterogeneity in disease progression trajectories,and accurate identificationof distinct trajectory-based phenotypes is critical for implementing personalized therapeutic strategies and prognostic assessment.However,trajectory clustering analysis of time-series clinical data poses substantial methodological challenges for researchers.This study provides a comprehensive tutorial framework demonstrating six trajectory modeling approaches integrated with proteomic analysis to guide researchers in identifying sepsis subtypes after laparoscopic surgery.Methods:This study employs simulated longitudinal data from 300 septic patients after laparoscopic surgery to demonstrate six trajectory modeling methods(group-based trajectory modeling,latent growth mixture modeling,latent transition analysis,time-varying effect modeling,K-means for longitudinal data,agglomerative hierarchical clustering)for identifying associations between predefinedsequential organ failure assessment trajectories and 25 proteomic biomarkers.Clustering performance was evaluated via multiple metrics,and a biomarker discovery pipeline integrating principal component analysis,random forests,feature selection,and receiver operating characteristic analysis was developed.Results:The six methods demonstrated varying performance in identifying trajectory structures,with each approach exhibiting distinct analytical characteristics.The performance metrics revealed differences across methods,which may inform context-specificmethod selection and interpretation strategies.Conclusion:This study illustrates practical implementations of trajectory modeling approaches under controlled conditions,facilitating informed method selection for clinical researchers.The inclusion of complete R code and integrated proteomics workflows offers a reproducible analytical framework connecting temporal pattern recognition to biomarker discovery.Beyond sepsis,this pipeline-oriented approach may be adapted to diverse clinical scenarios requiring longitudinal disease characterization and precision medicine applications.The comparative analysis reveals that each method has distinct strengths,providing a practical guide for clinical researchers in selecting appropriate methods based on their specificstudy goals and data characteristics.
基金funded by the National Natural Science Foundation of China(NSFC)under Grant No.52278415the National Key Research and Development Program of China under Grant No.2022YFC3801104+2 种基金Hebei Provincial Department of Education Project under Grant No.QN2025304the Innovation Fund Project of Hebei University of Engineering under Grant No.SJ2401002066the Sichuan Science and Technology Program under Grant No.2023YFS0407。
文摘The diversion effect caused by the linked structure in a metro tunnel with cross-passage complicates the impact of longitudinal fire source location on the smoke backflow layering behavior that has not been clarified,despite the fact that the scenario exists in practice.A series of laboratory-scale experiments were conducted in this study to investigate the smoke back-layering length in a model tunnel with cross-passage.The heat release rate,the velocity of longitudinal air flow,and the location of the fire source were all varied.It was found that the behavior of smoke backflow for the fire source located at the upstream of bifurcation point resembles a single-hole tunnel fire.As the fire source’s position shifts downstream from the bifurcation point,the length of smoke back-layering progressively increases.A competitive interaction exists between airflow diversion and smoke diversion during smoke backflow,significantly affecting the smoke back-layering length in the main tunnel.The dimensionless smoke back-layering length model was formulated in a tunnel featuring a cross-passage,taking into account the positions of longitudinal fire sources.The dimensionless smoke back-layering length exhibits a positive correlation with the 17/18 power of total heat release rate Q and a negative correlation with the 5/2 power of longitudinal ventilation velocity V.
基金supported by the Anhui Philosophical and Social Science Fund for University Research:The Application of Painting Psychological Analysis in College Students’Mental Health Education Courses(Grant#:2023AH052874),which has provided essential financial support for data collection.
文摘This study explores the core characteristics,dynamic progression of the depression-anxiety-stress network among Chinese higher vocational college freshmen and its association with life satisfaction,and identifies key nodes and critical intervention points.Participants were 295 higher vocational college freshmen(male=137;M=18.52,SD=0.69)completing two follow-up surveys(5-month interval).Measures included depression-anxiety-stress symptoms and life satisfaction,analyzed via cross-sectional and binary cross-lagged panel network analysis.The results showed that“Easily agitated”was the central node(strength=1.519,EI=1.967);“Irritable”and“Mouth Dryness”were top predictors(Out-EI=1.101,1.100),with depressive symptoms as the convergence hub.“Easily agitated”had the strongest direct negative impact on life satisfaction(cross-cluster out-predictability=−0.653).This study elucidates depression-anxietystress network mechanisms in higher vocational freshmen,providing a theoretical framework and targeted intervention guidance(e.g.,focusing on somatic and emotional nodes).
基金financially supported by Youth Science“Research on Failure Mechanism and Evaluation Method of Sand Control Measures for Railway Machinery in Sandy Area”(12302511)Ningxia Transportation Department Science and Technology Project(20200173)The Central Guidance on Local Science and Technology Development Funds(22ZY1QA005)。
文摘Investigating the wind-sand flow response regularity in the longitudinal slope sections of desert highways provides a scientific basis for selecting the slope of desert roads.This study uses the Tengger Desert section of the Wuhai-Maqin Expressway as a case study,employing CFD numerical simulation methods to calculate and analyze the wind-sand flow field distribution characteristics in different longitudinal slope sections.The results show that:(1)Along with the direction of the incoming flow,the windward and leeward slope toes of the embankment are low-wind-speed zones,with the wind speed at the leeward slope toe being even lower.The higher the embankment,the larger the low-wind-speed zone at the windward and leeward slope toes.As the longitudinal slope increases,the extent of the lowwind-speed zone at the same location along the route also increases.(2)Along the route direction,the wind speed at the windward and leeward slope toes decreases as embankment height increases.At the embankment toe,sand particles are transported from the top to the bottom of the longitudinal slope,and the greater the longitudinal slope,the stronger the transport effect.(3)Along the route direction,the sand accumulation around the embankment gradually gathers toward the bottom of the longitudinal slope as the slope increases.When the longitudinal slope is 3%and 4%,the trend of sand accumulation moving from the windward side at the end of the route to the leeward side at the start of the route is more significant.When the longitudinal slope is less than or equal to 3%,severe sand accumulation within the embankment range is reduced by 86.4%or more compared to when the slope is 4%.(4)Under the same longitudinal slope,the higher the embankment height,the smaller its transport rate.When the embankment height is the same,the greater the longitudinal slope,the greater the embankment transport rate.
基金supported by the National Natural Science Foundation of China(No.41941018)Shanghai Gaofeng Discipline Construction Funding.
文摘Strong seismic excitation and fault dislocation are likely to occur simultaneously in high-intensity seismic zones,causing severe damage to tunnels crossing active fault zones.This paper aims to develop a novel analytical solution to determine the longitudinal mechanical responses of tunnels subjected to the combined effects of seismic waves and strike-slip faulting.Adopting the elastic springbeam model,the seismic waves are modelled as shear horizontal(SH)waves and the fault dislocation follows an S-shaped pattern;the superposition principle for free-fielddisplacements caused by both effects is assumed.In addition,the transmission and reflectionof seismic waves at the fault-rock geological interface and the tangential contact conditions at the tunnel-rock interface are considered.The analytical model is validated against numerical simulations,confirmingits accuracy in calculating tunnel responses.Moreover,a parametric study is conducted to evaluate the impact of key factors,including fault displacement,fault zone width,fault dip angle,earthquake frequency,rock conditions,tunnel lining stiffness,and tangential contact conditions,on tunnel responses.Compared with each effect alone,the combined effects of seismic waves and strike-slip faulting significantlychange the tunnel deformation and internal forces,leading to increased tunnel responses,especially within the fault zone and near the fault-rock interfaces.Depending on specificparameters,tunnel responses can be classifiedinto seismic-dominated,faulting-dominated,and seismic-faulting coupled responses on the basis of the relative contributions of each effect.The proposed analytical solution can be applied to quickly predict the longitudinal mechanical behaviour of tunnels under such combined effects in engineering applications.
文摘Objective:To preliminarily construct and apply a longitudinal trajectory model for the prognosis of intracerebral hemorrhage(ICH)based on blood urea nitrogen(BUN)characteristics.Methods:Clinical data from 320 ICH patients admitted to our hospital between 2020 and 2024 were collected,including demographic information,National Institutes of Health Stroke Scale(NIHSS)scores at admission,dynamic changes in BUN levels during treatment,and 30-day survival outcomes.A latent class growth model(LCGM)was first used for preliminary modeling,followed by a latent growth mixture modeling(GMM)approach to determine the final model.Three classes of BUN trajectories for ICH prognosis were identified,and latent classes were established.GMM modeling was then performed on these latent classes,considering linear,quadratic,and cubic polynomial forms;six GMM models were constructed and individuals were assigned to latent trajectory groups for validation.Results:LCGM analysis ultimately identified three dynamic BUN trajectory groups:Sustained low-level group(76 cases,23.8%):BUN remained stable between 3.1-9.0 mmol/L,with the highest 30-day survival rate(98.7%).Fluctuating-declining group(222 cases,69.4%):BUN initially increased and then slowly decreased(peak at day 3:15.2 mmol/L),with a 30-day mortality of 8.1%(18/222),higher than the sustained low-level group.Sustained high-level group(22 cases,6.9%):BUN mean>9.0 mmol/L,with a 30-day mortality of 41.7%(P=0.000).GMM model fitting showed that the cubic polynomial GMM model was optimal(AIC=6754.474,BIC=6852.450,Entropy=0.905).Incorporating gender,age,and BMI as covariates revealed significant effects for gender(Estimate=0.045,-0.011,P=0.000,0.000).The AUC for predicting 30-day mortality was 0.88(sensitivity 82.8%,specificity 77.9%),which increased to 0.89 when combined with admission NIHSS scores.Conclusion:The LCGM+GMM model based on dynamic BUN trajectories effectively distinguishes prognostic subgroups in ICH patients.Patients with persistently elevated or fluctuating-rising BUN levels have a significantly higher mortality risk compared to those with sustained low levels.This model provides a new quantitative tool for early identification of high-risk patients and poor prognoses.
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.
