The Relationship Between Multiple Obesity Indices and Long-Term Prognosis in STEMI Patients:An Observational Cohort Study of 220 Cases

Objective:To investigate the association of body mass index(BMI),waist circumference(WC),and waist-to-height ratio(WHtR)with the long-term prognosis of ST-elevation myocardial infarction(STEMI)patients and to determine whether the combination of obesity indices can be used for risk stratification.Method:A multifactorial Cox regression analysis was performed using 3-year follow-up data from 220 STEMI patients to explore the relationship between obesity indicators and major adverse cardiovascular events(MACEs).The incidence of MACEs was also compared by combining BMI and WHtR.Results:WC was found to reduce the risk of MACEs within 25 months after myocardial infarction[hazard ratio(HR)=0.95,95%confidence interval(CI)=0.92-0.98,P<0.001].However,this effect was not significant beyond 25 months(HR=0.98,95%CI=0.97-1.07,P=0.49).Neither BMI nor WHtR were significantly associated with the risk of MACEs.The incidence of MACEs was highest in patients with low body weight(BMI<18.5 kg/m^(2))and WHtR>0.5,and lowest in obese patients(BMI≥28 kg/m^(2))with WHtR>0.5.Conclusions:BMI,WC,and WHtR were not significantly associated with the long-term prognosis of STEMI patients.However,the combination of BMI and WHtR can be useful for further stratifying patient risk.

Random dynamic analysis of vertical train–bridge systems under small probability by surrogate model and subset simulation with splitting

The response of the train–bridge system has an obvious random behavior.A high traffic density and a long maintenance period of a track will result in a substantial increase in the number of trains running on a bridge,and there is small likelihood that the maximum responses of the train and bridge happen in the total maintenance period of the track.Firstly,the coupling model of train–bridge systems is reviewed.Then,an ensemble method is presented,which can estimate the small probabilities of a dynamic system with stochastic excitations.The main idea of the ensemble method is to use the NARX(nonlinear autoregressive with exogenous input)model to replace the physical model and apply subset simulation with splitting to obtain the extreme distribution.Finally,the efficiency of the suggested method is compared with the direct Monte Carlo simulation method,and the probability exceedance of train responses under the vertical track irregularity is discussed.The results show that when the small probability of train responses under vertical track irregularity is estimated,the ensemble method can reduce both the calculation time of a single sample and the required number of samples.

Mechanism and effects of snow accumulations and controls by lightweight snow fences

This paper investigates the snowdrifts caused by lightweight fences along the lines on the flatland through the computational fluid dynamics method. The characteristic ambient flows around the solid fences and the porous fences with varied heights and bottom wind gaps are simulated in the numerical model, and the working mechanism of ＂interception＂ and ＂scouring＂ of the lightweight fences are analyzed. Based on the friction velocities near the ground, two sets of criteria are proposed to evaluate the deposition and erosion effects of different fences. According to flow separation and reattachment, the simplified relationships between the most likely positions for snow accumulations and fence parameters are devel- oped. The study indicates that the capabilities for snow interception by the solid fence without wind gap and the distance from which to the second snow coverage center both increase with the fence height. Furthermore, it is found that the scouring range for snow surface increases significantly with the size of wind gap, and the snow accumulation rate on the leeward side decreases with the increasing fence porosity.

A comprehensive review on coupling vibrations of train-bridge systems under external excitations

In recent years,high-speed railways in China have developed very rapidly,and the number and span of the railway bridges are keeping increasing.Meanwhile,frequent extreme disasters,such as strong winds,earthquakes and floods,pose a significant threat to the safety of the train–bridge systems.Therefore,it is of paramount importance to evaluate the safety and comfort of trains when crossing a bridge under external excitations.In these aspects,there is abundant research but lacks a literature review.Therefore,this paper provides a comprehensive state-of-the-art review of research works on train–bridge systems under external excitations,which includes crosswinds,waves,collision loads and seismic loads.The characteristics of external excitations,the models of the train–bridge systems under external excitations,and the representative research results are summarized and analyzed.Finally,some suggestions for further research of the coupling vibration of train–bridge system under external excitations are presented.

Rate Coefficients of Roaming Reaction H+MgH Using Ring Polymer Molecular Dynamics

The ring-polymer molecular dynamics(RPMD)was used to calculate the thermal rate coefficients of the multi-channel roaming reaction H+MgH→Mg+H_(2).Two reaction channels,tight and roaming,are explicitly considered.This is a pioneering attempt of exerting RPMD method to multichannel reactions.With the help of a newly developed optimization-interpolation protocol for preparing the initial structures and adaptive protocol for choosing the force constants,we have successfully obtained the thermal rate coefficients.The results are consistent with those from other theoretical methods,such as variational transition state theory and quantum dynamics.Especially,RPMD results exhibit negative temperature dependence,which is similar to the results from variational transition state theory but different from the ones from ground state quantum dynamics calculations.

Nucleation Mechanism of Iron in an External Magnetic Field

In this work,the solidification of liquid iron with or without external magnetic field was investigated by using two molecular dynamics methods,namely direct cooling and two-phase simulation.The influence of external magnetic field on the solidification is characterized by the critical temperature and radial distribution functions.Our computational results show that under external magnetic field,the solidification point tends to decrease significantly.By further analyzing the diffusion coefficients and viscosity,we attribute the effect to the stronger fluctuation of liquid iron atoms driven by the external magnetic field.

Creative development of college physical education from the perspective of humanity

Sports teaching is the focus of university sports work, is to cultivate students to master the basic knowledge of sports theory and sports practice skills, and have good health, an important way to become qualified successors of the socialist cause. However, there are many disadvantages in traditional college physical education, and it is difficult to arouse the enthusiasm and enthusiasm of students to learn sports. In this paper, the research status and development trend of university sports teaching in our country, put forward the ways and innovation of college sports teaching reform, so as to promote the college sports teaching reform and innovation effectively, and provide reference for the better development of college physical education. With the deepening of teaching reform in colleges and universities, teaching reform and innovation of college sports is also developed in the depth direction, this paper discusses the reform of college physical education problems from the perspective of humanity based on. To this end, first analyzes the concept of humanized teaching concept and characteristics, and analyzes it in the practical teaching activities in the current situation, and finally puts forward some countermeasures and suggestions for the implementation of the teaching activities of college sports, to promote the innovation and development of college physical education teaching activities.

Antithrombotic therapy and bleeding risk in the era of aggressive lipid-lowering:current evidence,clinical implications,and future perspectives

The clinical efficacy of proprotein convertase subtilisin/kexin type 9 inhibitors(PCSK9i)in reducing major cardiovascular adverse events related to atherosclerotic cardiovascular disease(ASCVD)has been well established in recent large randomized outcome trials.Although the cardiovascular and all-cause mortality benefit of PCSK9i remains inconclusive,current cholesterol management guidelines have been modified toward more aggressive goals for lowering low-density lipoprotein cholesterol(LDL-C).Consequently,the emerging concept of"the lower the better"has become the paradigm of ASCVD prevention.However,there is evidence from observational studies of a U-shaped association between baseline LDL-C levels and all-cause mortality in population-based cohorts.Among East Asian populations,low LDL-C was associated with an increased risk for hemorrhagic stroke in patients not on antithrombotic therapy.Accumulating evidence showed that low LDL-C was associated with an enhanced bleeding risk in patients on dual antiplatelet therapy following percutaneous coronary intervention.Additionally,low LDL-C was associated with a higher risk for incident atrial fibrillation and thereby,a possible increase in the risk for intracranial hemorrhage after initiation of anticoagulation therapy.The mechanism of low-LDL-C-related bleeding risk has not been fully elucidated.This review summarizes recent evidence of low-LDL-C-related bleeding risk in patients on antithrombotic therapy and discusses potential measures for reducing this risk,underscoring the importance of carefully weighing the pros and cons of aggressive LDL-C lowering in patients on antithrombotic therapy.

Mesoporous silica stabilized MOF nanoreactor for highly selective semi-hydrogenation of phenylacetylene via synergistic effect of Pd and Ru single site

Selective semi-hydrogenation of phenylacetylene to styrene is a crucial step in the polystyrene industry.Although Pd-based catalysts are widely used in this reaction due to their excellent hydrogenation activity,the selectivity for styrene remains a great challenge.Herein,we designed a mesoporous silica stabilized Pd-Ru@ZIF-8(MS Pd-Ru@ZIF-8)nanoreactor with novel Pd and Ru single site synergistic catalytical system for semi-hydrogenation of phenylacetylene.The nanoreactor exhibited a superior performance,achieving 98%conversion of phenylacetylene and 96%selectivity to styrene.Turnover frequency(TOF)of nanoreactor was up to as high as 2,188 h^(−1),which was 25 times and 5 times more than the single metal species catalysts,mesoporous silica stabilized Pd@ZIF-8 nanoreactor(MS Pd@ZIF-8),and mesoporous silica stabilized Ru@ZIF-8 nanoreactor(MS Ru@ZIF-8).This catalytic activity was attributed to the synergistic effect of Pd and Ru single site anchored strongly into the framework of ZIF-8,which reduced the desorption energy of styrene and increased the hydrogenation energy barrier of styrene.Importantly,since the ordered mesoporous silica was introduced into the nanoreactor shell to stabilize ZIF-8,MS Pd-Ru@ZIF-8 showed excellent reusability and stability.After the five cycles,the catalytical activity and selectivity still remained.This work provides insights for a synergistic catalytic system based on single-site active sites for selective hydrogenation reactions.

Bridge vibration under complex wind field and corresponding measurements: A review

Due to increased demands in transportation development,bridge construction has been extended to areas with complex wind fields.In addition to common flow features such as high wind speeds and strong turbulence intensity,in coastal areas,bridges are likely to be exposed to non-stationary and non-Gaussian high-speed wind fields during hurricane events.Bridges built in mountainous regions will experience varying wind directions,incident angles of attack(AOA),and wind speed variation due to undulating terrain.The complex wind fields are challenging to the bridge engineering community to which accurate calculation methods and suppression measures for bridge vibration are urgently required.In this paper,state-of-the-art research results are introduced through three categories:(a)the distinctive characteristics of complex wind fields in offshore and mountainous areas,(b)the categories of wind-induced vibrations for bridges,and(c)the suppression measures employed in engineering practices.Until now,the studies regarding the coupled bridge vibration in complex wind fields have made considerable progress,but a richer database of actual wind measurement results and more efficient simulation methods still need to be further established.

Aerodynamic impact of train-induced wind on a moving motor-van

The newly-built single-level rail-cum-road bridge brings the issue of the aerodynamic impact of train-induced wind on road automobiles.This research introduced a validated computational fluid dynamics(CFD)model regarding this concern.Such an aerodynamic impact mechanism was explored;a relationship between the transverse distance between train and motor-van(hereinfafter referred to as van)and the aerodynamic effects on the van was explored to help the optimization of bridge decks,and the relationship between the automobile speed and aerodynamic variations of a van was fitted to help traffic control.The fitting results are accurate enough for further research.It is noted that the relative speed of the two automobiles is not the only factor that influences the aerodynamic variations of the van,even at a confirmed relative velocity,the aerodynamic variations of the van vary a lot as the velocity proportion changes,and the most unfavorable case shows an increase of over 40%on the aerodynamic variations compared to the standard case.The decay of the aerodynamic effects shows that not all the velocity terms would enhance the aerodynamic variations;the coupled velocity term constrains the variation amplitude of moments and decreases the total amplitude by 20%–40%.