In this study,it is aimed to develop a generic model which calculates the trajectory of the ejection seat from the jet aircraft,by taking into account the parameters that will affect the seat movement such as the seat...In this study,it is aimed to develop a generic model which calculates the trajectory of the ejection seat from the jet aircraft,by taking into account the parameters that will affect the seat movement such as the seat’s launch speed,ejection direction,ejection angle,altitude of the aircraft,distance/height from the aircraft rudder and canopy,pilot and ejection seat weight.With the model algorithm proposed,the ejection seat trajectory model was developed on MATLAB.The ejection seat trajectory model is based on point mass trajectory mathematical model.In this study,an analytical study of the problem has been made for modeling the flight trajectory of the ejection seat after it has been ejected.Past studies were used as a basis for validation and simulation.By writing a generic MATLAB code,a user interface was developed and presented to the user as a module.This generic code that has been developed could be used for simulations by users in the future by revising it in accordance with their own job descriptions.展开更多
BACKGROUND There is no available data about the trajectory of heart failure(HF)with improved ejection fraction(EF)and patient clinical outcomes in Qatar.AIM To explore the difference in characteristics and outcomes be...BACKGROUND There is no available data about the trajectory of heart failure(HF)with improved ejection fraction(EF)and patient clinical outcomes in Qatar.AIM To explore the difference in characteristics and outcomes between patients with transient and sustained improvement in left ventricular ejection fraction(LVEF)and to determine the independent predictors for sustained improvement in LVEF.METHODS This is a retrospective cohort study that was conducted at the advanced HF clinic of a tertiary care hospital in Qatar between January 2017 and December 2018.This were divided into two groups:HF with transient improvement in EF(HFtimpEF)and HF with sustained improvement in EF(HFsimpEF).RESULTS A total of 175 patients with HF and improved EF were included.Among them 136(77.7%)patients showed sustained improvement in LVEF.The remaining patients with HFtimpEF were predominantly males[37(94.9%)vs 101(74.3%),P=0.005]with a higher incidence of ischemic cardiomyopathy[32(82.1%)vs 68(50.4%),P=0.002],dyslipidemia[24(61.5%)vs 54(39.7%),P=0.03],and hypertension[34(87.2%)vs 93(68.4%),P=0.03]than those with HFsimpEF.The latter experienced significantly lower rates of hospitalization[39(28.7%)vs 20(51.3%),P=0.01]and diagnosis of new cardiovascular conditions during the follow-up(e.g.,acute coronary syndrome,stroke,decompensated HF,and atrial fibrillation)[14(10.3%)vs 10(25.6%),P=0.03]without a difference in emergency department visits or in-hospital death.Sustained improvement in LVEF was positively associated with being female[adjusted odds ratio(aOR)=6.8,95%confidence interval(CI):1.4-32.3,P=0.02],having non-ischemic etiology of HF(aOR=3.1,95%CI:1.03-9.3,P=0.04),and using a mineralocorticoid receptor antagonist(aOR=7.0,95%CI:1.50-31.8,P=0.01).CONCLUSION Patients with HFsimpEF experienced significantly lower rates of hospitalization and diagnosis of new cardiova-scular conditions than patients with HFtimpEF.Sustained improvement in LVEF was positively associated with being a female,having non-ischemic etiology of HF,and using a mineralocorticoid receptor antagonist.展开更多
Heart failure(HF)with preserved ejection fraction(HFpEF)has exceeded HF with reduced ejection fraction(HFrEF),becoming the most common type of HF.Unlike HFrEF,HFpEF is primarily a chronic low-grade inflammatory proces...Heart failure(HF)with preserved ejection fraction(HFpEF)has exceeded HF with reduced ejection fraction(HFrEF),becoming the most common type of HF.Unlike HFrEF,HFpEF is primarily a chronic low-grade inflammatory process closely associated with metabolic disorders.The coexistence of HFpEF and metabolic dysfunction-associated steatotic liver disease(MASLD)presents significant clinical challenges due to shared metabolic pathophysiology and complex inter-play.Management strategies for HFpEF and MASLD remain challenging.Sodium-glucose cotransporter 2 inhibitors have shown benefits in managing both conditions.Additionally,glucagon-like peptide-1 receptor agonists are being actively investigated for their potential benefits,particularly in MASLD.A comprehensive,patient-centered approach that combines metabolic and cardiova-scular care is essential for improving outcomes in patients with HFpEF and MASLD,addressing the global metabolic health challenges.展开更多
The high-pressure mercury intrusion (HPMI) experiment is widely used to assess the pore architecture oftight sandstone reservoirs. However, the conventional analysis of the high- pressure mercury intrusionhas always f...The high-pressure mercury intrusion (HPMI) experiment is widely used to assess the pore architecture oftight sandstone reservoirs. However, the conventional analysis of the high- pressure mercury intrusionhas always focused on the mercury injection curves themselves, neglecting the important geologicalinformation conveyed by the mercury ejection curves. This paper quantitatively describes the fractalcharacteristics of ejection curves by using four fractal models, i.e.,. Menger model, Thermodynamicmodel, Sierpinski model, and multi- fractal model. In comparison with mercury injection curves, weexplore the fractal significance of mercury ejection curves and define the applicability of different fractalmodels in characterizing pore architectures. Investigated tight sandstone samples can be divided intofour types (Types A, B, C and D) based on porosity, permeability, and mercury removal efficiency. Type Dsamples are unique in that they have higher permeability (>0.6 mD) but lower mercury removal effi-ciency (<35%). Fractal studies of the mercury injection curve show that it mainly reflects the pore throatcharacteristics, while the mercury ejection curve serves to reveal the pore features, and porosity andpermeability correlate well with the fractal dimension of the injection curve, while mercury removalefficiency correlates only with the Ds' value of the ejection curve. The studies on the mercury ejectioncurves also reveal that the small pores and micropores of the Type C and Type D samples are moredeveloped, with varying pore architecture. The fractal dimension Ds' value of Type D samples is greaterthan that of Type C samples, and the dissolution of Type D samples is more intense than that of Type Csamples, which further indicates that the Type D samples are smaller in pore size, rougher in surface, andwith greater difficulty for the hydrocarbon to enter, resulting in their reservoir capacity probably lessthan that of Type C samples. In this regard, the important information characterized by the mercuryejection curve should be considered in evaluating the tight sandstone reservoirs. Finally, the Menger andThermodynamic models prove to be more suitable for describing the total pore architecture, while theSierpinski model is better for characterizing the variability of the interconnected pores.展开更多
Knowing the optimal operating parameters of Stirling engines is important for efficient combustion through adaptability to changed pressures and oxygen atmospheres. In this study, the optimum operating conditions for ...Knowing the optimal operating parameters of Stirling engines is important for efficient combustion through adaptability to changed pressures and oxygen atmospheres. In this study, the optimum operating conditions for efficient combustion in a singular Stirling engine combustor at different oxygen atmospheres were investigated and determined. Numerical simulations were performed to investigate the effects of ejection ratio and pressure on combustion performance. In an oxygen/carbon dioxide atmosphere, the results show that increasing the ejection ratio substantially alters the flame distribution in the Stirling engine combustor, increasing heat transfer and external combustion efficiency. In contrast, increasing the ejection ratio reduces the average and maximum temperatures of the Stirling engine combustor. Increased pressure affects the flame distribution in the Stirling engine combustor and impedes the flow and convective heat transfer in the combustor, reducing the overall external combustion efficiency at pressures above 6.5 MPa. In an air/carbon dioxide atmosphere, an increased ejection ratio reduces the average and maximum temperatures in the Stirling engine combustor. However, the overall flame distribution does not change substantially. The external combustion efficiency tends to increase and then decrease because of two opposing factors: the increase in the convective heat transfer coefficient and the decrease in the temperature difference. Increasing pressure inhibits forced convection heat transfer in the Stirling engine combustor, reducing external combustion efficiency, which drops from 78% to 65% when pressure increases from 0.2 MPa to 0.5 MPa.展开更多
BACKGROUND Obesity has become a serious public health issue,significantly elevating the risk of various complications.It is a well-established contributor to Heart failure with preserved ejection fraction(HFpEF).Evalu...BACKGROUND Obesity has become a serious public health issue,significantly elevating the risk of various complications.It is a well-established contributor to Heart failure with preserved ejection fraction(HFpEF).Evaluating HFpEF in obesity is crucial.Epicardial adipose tissue(EAT)has emerged as a valuable tool for validating prognostic biomarkers and guiding treatment targets.Hence,assessing EAT is of paramount importance.Cardiovascular magnetic resonance(CMR)imaging is acknowledged as the gold standard for analyzing cardiac function and mor-phology.We hope to use CMR to assess EAT as a bioimaging marker to evaluate HFpEF in obese patients.AIM To assess the diagnostic utility of CMR for evaluating heart failure with preserved ejection fraction[HFpEF;left ventricular(LV)ejection fraction≥50%]by measuring the epicardial adipose tissue(EAT)volumes and EAT mass in obese patients.METHODS Sixty-two obese patients were divided into two groups for a case-control study based on whether or not they had heart failure with HFpEF.The two groups were defined as HFpEF+and HFpEF-.LV geometry,global systolic function,EAT volumes and EAT mass of all subjects were obtained using cine magnetic resonance sequences.RESULTS Forty-five patients of HFpEF-group and seventeen patients of HFpEF+group were included.LV mass index(g/m2)of HFpEF+group was higher than HFpEF-group(P<0.05).In HFpEF+group,EAT volumes,EAT volume index,EAT mass,EAT mass index and the ratio of EAT/[left atrial(LA)left-right(LR)diameter]were higher compared to HFpEF-group(P<0.05).In multivariate analysis,Higher EAT/LA LR diameter ratio was associated with higher odds ratio of HFpEF.CONCLUSION EAT/LA LR diameter ratio is highly associated with HFpEF in obese patients.It is plausible that there may be utility in CMR for assessing obese patients for HFpEF using EAT/LA LR diameter ratio as a diagnostic biomarker.Further prospective studies,are needed to validate these proof-of-concept findings.展开更多
In heart failure with preserved ejection fraction,significant left ventricular diastolic abnormalities are present,despite a normal systolic ejection fraction.This article will consider whether this is consistent with...In heart failure with preserved ejection fraction,significant left ventricular diastolic abnormalities are present,despite a normal systolic ejection fraction.This article will consider whether this is consistent with the law of conservation of energy,also know as the first law of thermodynamics.展开更多
Heart failure (HF) is a chronic condition characterized by the heart’s inability to pump blood effectively. Hypertension is a frequent contributing factor. The reduced cardiac output leads to fluid accumulation, caus...Heart failure (HF) is a chronic condition characterized by the heart’s inability to pump blood effectively. Hypertension is a frequent contributing factor. The reduced cardiac output leads to fluid accumulation, causing respiratory distress and chest pain. Ejection fraction (EF), a measure of the left ventricle’s pumping capacity, is crucial in HF diagnosis. HF with reduced EF (HFrEF) is defined by an EF below 40%, often caused by coronary artery disease—approximately half of all HF patients present with HFrEF. The remaining cases encompass HF with mid-range EF (40% - 50%) or HF with preserved EF (HFpEF, EF ≥ 50%).展开更多
It is generally believed that coronal mass ejections(CMEs)have magnetic flux rope structures because of their helical shapes.However,only about 30%–40%of interplanetary CMEs(ICMEs)have a local magnetic flux rope stru...It is generally believed that coronal mass ejections(CMEs)have magnetic flux rope structures because of their helical shapes.However,only about 30%–40%of interplanetary CMEs(ICMEs)have a local magnetic flux rope structure.The usual explanations are that the spacecraft only crossed the flank of the ropes and failed to detect the complete magnetic flux rope structure or that some processes destroyed these magnetic flux rope structures.Several studies suggest that some ICMEs inherently possess disordered magnetic fields and consequently exhibit no magnetic flux-rope structures.We introduce a special kind of ICME which has a low magnetic field magnitude and stable magnetic field direction,relatively fast expansion speed,and lower proton temperature and density.All three of the measured magnetic field components are relatively stable.We want to know whether these ICMEs also have magnetic flux rope structures or not.We identified 20 special ICMEs and analyzed their evolution based on their observed characteristics.We took a special ICME as an example,which had an apparent rope configuration at 1 au but evolved to a special ICME at 5.4 au,to illustrate that this kind of ICME could come from magnetic clouds(MCs)whose rope structure had been being stretched due to expansion.We inferred that the missing obvious flux rope structure may be due to the expansion of MCs,not the flank crossing effect.However,more than 50%of the events were associated with the dominant x-component of the magnetic field,which indicates a leg crossing.Therefore,the detection of part of these special ICMEs may also be the result of the leg-crossing effect.展开更多
Objective:To determine factors that affect the health-related quality of life(HRQOL)of congestive heart failure(CHF)patients with preserved and reduced ejection fraction.Methods:A cross-sectional study design was used...Objective:To determine factors that affect the health-related quality of life(HRQOL)of congestive heart failure(CHF)patients with preserved and reduced ejection fraction.Methods:A cross-sectional study design was used for this study.The stratified random sampling was applied for each subgroup.HRQOL was measured with the Minnesota Living with Hear t Failure Questionnaire.The data were analyzed using chi-square,Spearman's correlation analysis,and independent t-test.Results:A number of 67 respondents participated in the recent study.The total mean scores of HRQOL were significantly different(P=0.001)between heart failure(HF)patients with reduced and preserved ejection fractions,41.07±7.54 and 54.97±4.36,respectively.It related with the physical(mean±standard deviation[SD]=10.4±2.14;t=-10.08,95%CI=-12.46 to-8.34;P-value=0.001)and psychological(mean±SD=3.5±0.5;t=-6.68,95%CI=-4.55 to-2.45;P-value=0.001)domain.Strong correlation was found between age(r=-0.898,P<0.05),NYHA functional classes(r=-0.858,P<0.01),duration of HF(r=-0.807,P<0.01),family support(r=0.927,P<0.01),and quality of life(Qo L).Conclusions:HRQOL in HF patients with reduced ejection fraction was higher than in those with preserved ejection fraction.Family suppor t is a fur ther determinant factor that has a positive correlation to the Qo L.展开更多
Background:Formononetin(FMN)has beneficial effects in cardiovascular diseases but its functions and mechanisms in heart failure with preserved ejection fraction(HFpEF)remain unclear.This study aimed at determining whe...Background:Formononetin(FMN)has beneficial effects in cardiovascular diseases but its functions and mechanisms in heart failure with preserved ejection fraction(HFpEF)remain unclear.This study aimed at determining whether FMN ameliorated HFpEF-induced cardiac dysfunction and exploring its underlying mechanisms.Methods:The mouse model of HFpEF was established through uninephrectomy surgery and d-aldosterone infusion in C57BL/6 mice.Cardiac remodeling and potential mechanisms of FMN in HFpEF were assessed by histological analysis,immunofluorescence,echocardiography,real-time PCR and western blotting sequentially.Results:FMN prevented myocardial dysfunction,fibrosis and cardiomyocyte apoptosis.The mRNA levels of left ventricular hypertrophy markers were increased in HFpEF mice but they remained unchanged in FMN-treated mice.In addition,the expression levels of PPARαand PGC-1 were increased in HFpEF mice for FMN treatment.The PPARα-PGC-1 complex affected the expression of fatty acid content and encoded enzymes in glucose metabolism.Both the hypertrophy and metabolic impairment due to FMN in HFpEF mice were alleviated after the addition of PPARαantagonist GW6471.Conclusion:In conclusion,FMN could prevent the cardiac hypertrophy in HFpEF mice by activating the PPARα/PGC-1 pathway and regulating energy metabolism,which provides a new therapeutic strategy for HFpEF patients.展开更多
Heart failure with preserved ejection fraction(HFpEF)is a clinical syndrome characterized by symptoms and sings of heart failure with elevated left ventricular filling pressures at rest or during exercise.It is the mo...Heart failure with preserved ejection fraction(HFpEF)is a clinical syndrome characterized by symptoms and sings of heart failure with elevated left ventricular filling pressures at rest or during exercise.It is the most common type of heart failure in the elderly and its prevalence increases with age and is higher in females at any given age.HFpEF is frequently accompanied of comorbid conditions such as diabetes mellitus,obesity,atrial fibrillation and renal dysfunction.The diagnosis relies in the integration of clinical information,laboratory data and interpretation of cardiac imaging and hemodynamic findings at rest and during exercise.Conditions that have a specific treatment such as coronary artery disease,valvular disease,cardiac amyloidosis and constrictive pericarditis should be considered and evaluated as appropriate.Aggressive management of comorbidities,optimization of blood pressure control and volume status using diuretics as needed are among the current treatment recommendations.There are no specific therapies that have shown to decrease mortality in HFpEF.In symptomatic patients with history of hospital admission for decompensated heart failure,the implantation of a wireless pulmonary artery pressure monitor should be considered.Finally,given the high mortality of this condition,goals of care discussion should be initiated early and involvement of palliative care medicine should be considered.展开更多
micro RNAs(mi RNAs) are powerful regulators of posttranscriptional gene expression and play an important role in pathophysiological processes. Circulating mi RNAs can be quantified in body liquids and are promising bi...micro RNAs(mi RNAs) are powerful regulators of posttranscriptional gene expression and play an important role in pathophysiological processes. Circulating mi RNAs can be quantified in body liquids and are promising biomarkers in numerous diseases. In cardiovascular disease mi RNAs have been proven to be reliable diagnostic biomarkers for different disease entities. In cardiac fibrosis(CF) and heart failure(HF) dysregulated circulating mi RNAs have been identified,indicating their promising applicability as diagnostic biomarkers. Some mi RNAs were successfully tested in risk stratification of HF implementing their potential use as prognostic biomarkers. In this respect mi RNAs might soon be implemented in diagnostic clinical routine. In the young field of mi RNA based research advances have been made in identifying mi RNAs as potential targets for the treatment of experimental CF and HF. Promising study results suggest their potential future application as therapeutic agents in treatment of cardiovascular disease. This article summarizes the current state of the various aspects of mi RNA research in the field of CF and HF with reduced ejection fraction as well as preserved ejection fraction. The review provides an overview of the application of circulating mi RNAs as biomarkers in CF and HF and current approaches to therapeutically utilize mi RNAs in this field of cardiovascular disease.展开更多
Heart failure with preserved ejection fraction(HFPEF)is common and represents a major challenge in cardiovascular medicine.Most of the current treatment of HFPEF is based on morbidity benefits and symptom reduction.Va...Heart failure with preserved ejection fraction(HFPEF)is common and represents a major challenge in cardiovascular medicine.Most of the current treatment of HFPEF is based on morbidity benefits and symptom reduction.Various pharmacological interventions available for heart failure with reduced ejection fraction have not been supported by clinical studies for HFPEF.Addressing the specific aetiology and aggressive risk factor modification remain the mainstay in the treatment of HFPEF.We present a brief overview of the currently recommended therapeutic options with available evidence.展开更多
In this study,we established a dynamic ejection coal burst model for a coalmine roadway subject to stress,and held that the stress concentration zone at the roadway side is the direct energy source of this ejection.Th...In this study,we established a dynamic ejection coal burst model for a coalmine roadway subject to stress,and held that the stress concentration zone at the roadway side is the direct energy source of this ejection.The formation and development of such burst undergoes three stages:(1)instability and propagation of the cracks in the stress concentration zone,(2)emerging of a layered energy storage structure in the zone,and(3)ejection of coal mass or coal burst due to instability.Moreover,we figured out the initial strength of periodic cracks is parallel to the maximal dominant stress direction in the stress concentration zone and derived from the damage strain energy within the finite area of the zone based on the Griffith energy theory.In addition,we analyzed the formation process of the layered energy storage structure in the zone,simplified it as a simply supported restraint sheet,and calculated the minimum critical load and the internally accumulated elastic energy at the instable state.Furthermore,we established a criterion for occurrence of the coal burst based on the variational principle,and analyzed the coal mass ejection due to instability and coal burst induced by different intensity disturbances.At last,with the stratum conditions of Junde Coalmine as the model prototype,we numerically simulated the load displacement distribution of the stress concentration zone ahead of the working face disturbed by the main roof-fracture-induced dynamic load during the mining process as well as their varying characteristics,and qualitatively verified the above model.展开更多
Heart failure(HF) is the leading cause of hospitalization among older adults and the prevalence is growing with the aging populations in the Western countries. Epidemiologic reports suggest that approximately 50% of p...Heart failure(HF) is the leading cause of hospitalization among older adults and the prevalence is growing with the aging populations in the Western countries. Epidemiologic reports suggest that approximately 50% of patients who have signs or symptoms of HF have preserved left ventricular ejection fraction. This HF type predominantly affects women and the elderly with other co-morbidities, such as diabetes, hypertension, and overt volume status. Most of the current treatment strategies are based on morbidity benefits such as quality of life and reduction of clinical HF symptoms. Treatment of patients with HF with preserved ejection fraction displayed disappointing results from several large randomized controlled trials. The heterogeneity of HF with preserved ejection fraction, understood as complex syndrome, seems to be one of the primary reasons. Here, we present an overview of the current management strategies with available evidence and new therapeutic approach from drugs currently in clinical trials, which target diastolic dysfunction, chronotropic incompetence, and risk factor management. We provide an outline and interpretation of recent clinical trials that failed to improve outcome and survival in patients with HF with preserved ejection fraction.展开更多
Left ventricular ejection fraction(LVEF)is an impor-tant predictor of cardiac outcome and helps in makingimportant diagnostic and therapeutic decisions suchas the treatment of different types of congestive heartfailur...Left ventricular ejection fraction(LVEF)is an impor-tant predictor of cardiac outcome and helps in makingimportant diagnostic and therapeutic decisions suchas the treatment of different types of congestive heartfailure or implantation of devices like cardiac resynchro-nization therapy-defibrillator.LVEF can be measuredby various techniques such as transthoracic echo-cardiography,contrast ventriculography,radionuclidetechniques,cardiac magnetic resonance imaging andcardiac computed tomographic angiography(CTA).Thedevelopment of cardiac CTA using multi-detector rowCT(MDCT)has seen a very rapid improvement in thetechnology for identifying coronary artery stenosis andcoronary artery disease in the last decade.During theacquisition,processing and analysis of data to studycoronary anatomy,MDCT provides a unique opportunityto measure left ventricular volumes and LVEF simulta-neously with the same data set without the need foradditional contrast or radiation exposure.The develop-ment of semi-automated and automated software to measure LVEF has now added uniformity,efficiency and reproducibility of practical value in clinical practice rather than just being a research tool.This article will address the feasibility,the accuracy and the limitations of MDCT in measuring LVEF.展开更多
In pulsed laser drilling, melt ejection greatly influences the keyhole shape and its quality as well, but its mechanism has not been well understood. In this paper, numerical simulation and experimental investigations...In pulsed laser drilling, melt ejection greatly influences the keyhole shape and its quality as well, but its mechanism has not been well understood. In this paper, numerical simulation and experimental investigations based on 304 stainless steel and aluminum targets are performed to study the effects of material parameters on melt ejection. The numerical method is employed to predict the temperatures, velocity fields in the solid, liquid, and vapour front, and melt pool dynamics of targets as well. The experimental methods include the shadow-graphic technique, weight method, and optical microscope imaging, which are applied to real-time observations of melt ejection phenomena, measurements of collected melt and changes of target mass, observations of surface morphology and the cross-section of the keyhole, respectively. Numerical and experimental results show that the metallic material with high thermal diffusivity like aluminum is prone to have a thick liquid zone and a large quantity of melt ejection. Additionally, to the best of our knowledge, the liquid zone is used to illustrate the relations between melt ejection and material thermal diffusivity for the first time. The research result in this paper is useful for manufacturing optimization and quality control in laser-material interaction.展开更多
Background Endogenous aldehyde damages DNA and potentiates an ageing phenotype. The aldehyde dehydrogenase 2(ALDH2) rs671 polymorphism has a prevalence of 30%–50% in Asian populations. In this study, we aimed to anal...Background Endogenous aldehyde damages DNA and potentiates an ageing phenotype. The aldehyde dehydrogenase 2(ALDH2) rs671 polymorphism has a prevalence of 30%–50% in Asian populations. In this study, we aimed to analyze risk factors contributing to the development of heart failure with preserved ejection fraction(HFpEF) along with the genetic exposure in Chinese patients hospitalized with cardiovascular diseases(CVD). Methods From July 2017 to October 2018, a total of 770 consecutive Chinese patients with normal left ventricular ejection fractions(LVEF) and established CVD(hypertension, coronary heart diseases, or diabetes) were enrolled in this prospective cross-sectional study. HFpEF was defined by the presence of at least one of symptom(dyspnoea and fatigue) or sign(rales and ankle swelling) related to heart failure;N-terminal pro-B-Type natriuretic peptide(NT pro-BNP ≥ 280 pg/mL);LVEF ≥ 50%;and at least one criterion related to elevated ventricular filling pressure or diastolic dysfunction(left atrial diameter > 40 mm, E/E’ ≥ 13, E’/A’ < 1 or concurrent atrial fibrillation). Logistic regression was performed to yield adjusted odds ratios(ORs) for HFp EF incidence associated with traditional and/or genetic exposures. Results Finally, among 770 patients with CVD, 92(11.9%) patients were classified into the HFpEF group according to the diagnostic criteria. The mean age of the participants was 67 ± 12 years, and 278(36.1%) patients were females. A total of 303(39.4%) patients were ALDH2*2 variant carriers. In the univariate analysis, eight exposures were found to be associated with HFpEF: atrial fibrillation, ALDH2*2 variants, hypertension, age, anaemia, smoking, alcohol consumption and sex. Multivariable logistic regression showed that 4 ‘A’ variables(atrial fibrillation, ALDH2*2 variants, age and anaemia) were significantly associated with an increased risk of HFpEF. Atrial fibrillation was associated with a 3.8-fold increased HFpEF risk(95% CI: 2.21–6.61, P < 0.001), and the other three exposures associated with increased HFpEF risk were the ALDH2*2 variant(OR = 2.41, 95% CI: 1.49–3.87, P < 0.001), age(OR = 2.14, 95% CI: 1.27–3.60, P = 0.004), and anaemia(OR = 1.79, 95% CI: 1.05–3.03, P = 0.032). These four variables predicted HFpEF incidence in Chinese CVD patients(C-statistic = 0.745, 95% CI: 0.691–0.800, P < 0.001). Conclusions 4 A traits(atrial fibrillation, ALDH2*2 variants, age and anaemia) were associated with an increased risk of HFpEF in Chinese CVD patients. Our results provide potential clues to the aetiology, pathophysiology and therapeutic targets of HFpEF.展开更多
The parachute container cover ejection separation is the first and foremost motion for the return capsule recovery system,which is related to the success of a recovery system.Adopting the computational fluid dynamics(...The parachute container cover ejection separation is the first and foremost motion for the return capsule recovery system,which is related to the success of a recovery system.Adopting the computational fluid dynamics(CFD)simulation and flight dynamics coupling method,the parachute container cover ejection separation is simulated.The rationality of the ejection separation speed and dynamic characteristics of the separation process is analyzed.Meanwhile,the influences of angle of attack,Mach number and ejection separation speed on the parachute container cover ejection are also investigated.Results show that the ejection separation speed design is reasonable.It has a certain design margin for parachute container cover to escape from the wake region,and to pull out the drag parachute completely.The results may provide a theoretical basis for recovery system engineering design of the lunar exploration project.展开更多
文摘In this study,it is aimed to develop a generic model which calculates the trajectory of the ejection seat from the jet aircraft,by taking into account the parameters that will affect the seat movement such as the seat’s launch speed,ejection direction,ejection angle,altitude of the aircraft,distance/height from the aircraft rudder and canopy,pilot and ejection seat weight.With the model algorithm proposed,the ejection seat trajectory model was developed on MATLAB.The ejection seat trajectory model is based on point mass trajectory mathematical model.In this study,an analytical study of the problem has been made for modeling the flight trajectory of the ejection seat after it has been ejected.Past studies were used as a basis for validation and simulation.By writing a generic MATLAB code,a user interface was developed and presented to the user as a module.This generic code that has been developed could be used for simulations by users in the future by revising it in accordance with their own job descriptions.
文摘BACKGROUND There is no available data about the trajectory of heart failure(HF)with improved ejection fraction(EF)and patient clinical outcomes in Qatar.AIM To explore the difference in characteristics and outcomes between patients with transient and sustained improvement in left ventricular ejection fraction(LVEF)and to determine the independent predictors for sustained improvement in LVEF.METHODS This is a retrospective cohort study that was conducted at the advanced HF clinic of a tertiary care hospital in Qatar between January 2017 and December 2018.This were divided into two groups:HF with transient improvement in EF(HFtimpEF)and HF with sustained improvement in EF(HFsimpEF).RESULTS A total of 175 patients with HF and improved EF were included.Among them 136(77.7%)patients showed sustained improvement in LVEF.The remaining patients with HFtimpEF were predominantly males[37(94.9%)vs 101(74.3%),P=0.005]with a higher incidence of ischemic cardiomyopathy[32(82.1%)vs 68(50.4%),P=0.002],dyslipidemia[24(61.5%)vs 54(39.7%),P=0.03],and hypertension[34(87.2%)vs 93(68.4%),P=0.03]than those with HFsimpEF.The latter experienced significantly lower rates of hospitalization[39(28.7%)vs 20(51.3%),P=0.01]and diagnosis of new cardiovascular conditions during the follow-up(e.g.,acute coronary syndrome,stroke,decompensated HF,and atrial fibrillation)[14(10.3%)vs 10(25.6%),P=0.03]without a difference in emergency department visits or in-hospital death.Sustained improvement in LVEF was positively associated with being female[adjusted odds ratio(aOR)=6.8,95%confidence interval(CI):1.4-32.3,P=0.02],having non-ischemic etiology of HF(aOR=3.1,95%CI:1.03-9.3,P=0.04),and using a mineralocorticoid receptor antagonist(aOR=7.0,95%CI:1.50-31.8,P=0.01).CONCLUSION Patients with HFsimpEF experienced significantly lower rates of hospitalization and diagnosis of new cardiova-scular conditions than patients with HFtimpEF.Sustained improvement in LVEF was positively associated with being a female,having non-ischemic etiology of HF,and using a mineralocorticoid receptor antagonist.
基金Supported by Wenzhou Science Technology Bureau Foundation,No.2022Y0726.
文摘Heart failure(HF)with preserved ejection fraction(HFpEF)has exceeded HF with reduced ejection fraction(HFrEF),becoming the most common type of HF.Unlike HFrEF,HFpEF is primarily a chronic low-grade inflammatory process closely associated with metabolic disorders.The coexistence of HFpEF and metabolic dysfunction-associated steatotic liver disease(MASLD)presents significant clinical challenges due to shared metabolic pathophysiology and complex inter-play.Management strategies for HFpEF and MASLD remain challenging.Sodium-glucose cotransporter 2 inhibitors have shown benefits in managing both conditions.Additionally,glucagon-like peptide-1 receptor agonists are being actively investigated for their potential benefits,particularly in MASLD.A comprehensive,patient-centered approach that combines metabolic and cardiova-scular care is essential for improving outcomes in patients with HFpEF and MASLD,addressing the global metabolic health challenges.
基金The research project was co-funded by the National Natural Science Foundation of China(No.42072172,No.41772120)Shandong Province Natural Science Fund for Distinguished Young Scholars(No.JQ201311)the Graduate Scientific and Technological Innovation Project Financially Supported by Shandong University of Science and Technology(No.SDKDYC190313).
文摘The high-pressure mercury intrusion (HPMI) experiment is widely used to assess the pore architecture oftight sandstone reservoirs. However, the conventional analysis of the high- pressure mercury intrusionhas always focused on the mercury injection curves themselves, neglecting the important geologicalinformation conveyed by the mercury ejection curves. This paper quantitatively describes the fractalcharacteristics of ejection curves by using four fractal models, i.e.,. Menger model, Thermodynamicmodel, Sierpinski model, and multi- fractal model. In comparison with mercury injection curves, weexplore the fractal significance of mercury ejection curves and define the applicability of different fractalmodels in characterizing pore architectures. Investigated tight sandstone samples can be divided intofour types (Types A, B, C and D) based on porosity, permeability, and mercury removal efficiency. Type Dsamples are unique in that they have higher permeability (>0.6 mD) but lower mercury removal effi-ciency (<35%). Fractal studies of the mercury injection curve show that it mainly reflects the pore throatcharacteristics, while the mercury ejection curve serves to reveal the pore features, and porosity andpermeability correlate well with the fractal dimension of the injection curve, while mercury removalefficiency correlates only with the Ds' value of the ejection curve. The studies on the mercury ejectioncurves also reveal that the small pores and micropores of the Type C and Type D samples are moredeveloped, with varying pore architecture. The fractal dimension Ds' value of Type D samples is greaterthan that of Type C samples, and the dissolution of Type D samples is more intense than that of Type Csamples, which further indicates that the Type D samples are smaller in pore size, rougher in surface, andwith greater difficulty for the hydrocarbon to enter, resulting in their reservoir capacity probably lessthan that of Type C samples. In this regard, the important information characterized by the mercuryejection curve should be considered in evaluating the tight sandstone reservoirs. Finally, the Menger andThermodynamic models prove to be more suitable for describing the total pore architecture, while theSierpinski model is better for characterizing the variability of the interconnected pores.
基金Supported by the Shanghai Rising Star Program (Grant No. 21QB1403900)the Shanghai Municipal Commission of Science and Technology (Grant No. 22170712600)。
文摘Knowing the optimal operating parameters of Stirling engines is important for efficient combustion through adaptability to changed pressures and oxygen atmospheres. In this study, the optimum operating conditions for efficient combustion in a singular Stirling engine combustor at different oxygen atmospheres were investigated and determined. Numerical simulations were performed to investigate the effects of ejection ratio and pressure on combustion performance. In an oxygen/carbon dioxide atmosphere, the results show that increasing the ejection ratio substantially alters the flame distribution in the Stirling engine combustor, increasing heat transfer and external combustion efficiency. In contrast, increasing the ejection ratio reduces the average and maximum temperatures of the Stirling engine combustor. Increased pressure affects the flame distribution in the Stirling engine combustor and impedes the flow and convective heat transfer in the combustor, reducing the overall external combustion efficiency at pressures above 6.5 MPa. In an air/carbon dioxide atmosphere, an increased ejection ratio reduces the average and maximum temperatures in the Stirling engine combustor. However, the overall flame distribution does not change substantially. The external combustion efficiency tends to increase and then decrease because of two opposing factors: the increase in the convective heat transfer coefficient and the decrease in the temperature difference. Increasing pressure inhibits forced convection heat transfer in the Stirling engine combustor, reducing external combustion efficiency, which drops from 78% to 65% when pressure increases from 0.2 MPa to 0.5 MPa.
基金National Natural Science Foundation of China,No.81873887National Natural Science Foundation of China Youth Project,No.82101981Shanghai Jiao Tong University School of Medicine Double Hundred Outstanding Person Project,No.20191904。
文摘BACKGROUND Obesity has become a serious public health issue,significantly elevating the risk of various complications.It is a well-established contributor to Heart failure with preserved ejection fraction(HFpEF).Evaluating HFpEF in obesity is crucial.Epicardial adipose tissue(EAT)has emerged as a valuable tool for validating prognostic biomarkers and guiding treatment targets.Hence,assessing EAT is of paramount importance.Cardiovascular magnetic resonance(CMR)imaging is acknowledged as the gold standard for analyzing cardiac function and mor-phology.We hope to use CMR to assess EAT as a bioimaging marker to evaluate HFpEF in obese patients.AIM To assess the diagnostic utility of CMR for evaluating heart failure with preserved ejection fraction[HFpEF;left ventricular(LV)ejection fraction≥50%]by measuring the epicardial adipose tissue(EAT)volumes and EAT mass in obese patients.METHODS Sixty-two obese patients were divided into two groups for a case-control study based on whether or not they had heart failure with HFpEF.The two groups were defined as HFpEF+and HFpEF-.LV geometry,global systolic function,EAT volumes and EAT mass of all subjects were obtained using cine magnetic resonance sequences.RESULTS Forty-five patients of HFpEF-group and seventeen patients of HFpEF+group were included.LV mass index(g/m2)of HFpEF+group was higher than HFpEF-group(P<0.05).In HFpEF+group,EAT volumes,EAT volume index,EAT mass,EAT mass index and the ratio of EAT/[left atrial(LA)left-right(LR)diameter]were higher compared to HFpEF-group(P<0.05).In multivariate analysis,Higher EAT/LA LR diameter ratio was associated with higher odds ratio of HFpEF.CONCLUSION EAT/LA LR diameter ratio is highly associated with HFpEF in obese patients.It is plausible that there may be utility in CMR for assessing obese patients for HFpEF using EAT/LA LR diameter ratio as a diagnostic biomarker.Further prospective studies,are needed to validate these proof-of-concept findings.
文摘In heart failure with preserved ejection fraction,significant left ventricular diastolic abnormalities are present,despite a normal systolic ejection fraction.This article will consider whether this is consistent with the law of conservation of energy,also know as the first law of thermodynamics.
文摘Heart failure (HF) is a chronic condition characterized by the heart’s inability to pump blood effectively. Hypertension is a frequent contributing factor. The reduced cardiac output leads to fluid accumulation, causing respiratory distress and chest pain. Ejection fraction (EF), a measure of the left ventricle’s pumping capacity, is crucial in HF diagnosis. HF with reduced EF (HFrEF) is defined by an EF below 40%, often caused by coronary artery disease—approximately half of all HF patients present with HFrEF. The remaining cases encompass HF with mid-range EF (40% - 50%) or HF with preserved EF (HFpEF, EF ≥ 50%).
基金support from the National Natural Science Foundation of China(NSFC,Grant Nos.41974197,41804162,and 42104158)supported by Central Plains Science and Technology Innovation Leading Talents of Henan Province under grant No.244200510012。
文摘It is generally believed that coronal mass ejections(CMEs)have magnetic flux rope structures because of their helical shapes.However,only about 30%–40%of interplanetary CMEs(ICMEs)have a local magnetic flux rope structure.The usual explanations are that the spacecraft only crossed the flank of the ropes and failed to detect the complete magnetic flux rope structure or that some processes destroyed these magnetic flux rope structures.Several studies suggest that some ICMEs inherently possess disordered magnetic fields and consequently exhibit no magnetic flux-rope structures.We introduce a special kind of ICME which has a low magnetic field magnitude and stable magnetic field direction,relatively fast expansion speed,and lower proton temperature and density.All three of the measured magnetic field components are relatively stable.We want to know whether these ICMEs also have magnetic flux rope structures or not.We identified 20 special ICMEs and analyzed their evolution based on their observed characteristics.We took a special ICME as an example,which had an apparent rope configuration at 1 au but evolved to a special ICME at 5.4 au,to illustrate that this kind of ICME could come from magnetic clouds(MCs)whose rope structure had been being stretched due to expansion.We inferred that the missing obvious flux rope structure may be due to the expansion of MCs,not the flank crossing effect.However,more than 50%of the events were associated with the dominant x-component of the magnetic field,which indicates a leg crossing.Therefore,the detection of part of these special ICMEs may also be the result of the leg-crossing effect.
文摘Objective:To determine factors that affect the health-related quality of life(HRQOL)of congestive heart failure(CHF)patients with preserved and reduced ejection fraction.Methods:A cross-sectional study design was used for this study.The stratified random sampling was applied for each subgroup.HRQOL was measured with the Minnesota Living with Hear t Failure Questionnaire.The data were analyzed using chi-square,Spearman's correlation analysis,and independent t-test.Results:A number of 67 respondents participated in the recent study.The total mean scores of HRQOL were significantly different(P=0.001)between heart failure(HF)patients with reduced and preserved ejection fractions,41.07±7.54 and 54.97±4.36,respectively.It related with the physical(mean±standard deviation[SD]=10.4±2.14;t=-10.08,95%CI=-12.46 to-8.34;P-value=0.001)and psychological(mean±SD=3.5±0.5;t=-6.68,95%CI=-4.55 to-2.45;P-value=0.001)domain.Strong correlation was found between age(r=-0.898,P<0.05),NYHA functional classes(r=-0.858,P<0.01),duration of HF(r=-0.807,P<0.01),family support(r=0.927,P<0.01),and quality of life(Qo L).Conclusions:HRQOL in HF patients with reduced ejection fraction was higher than in those with preserved ejection fraction.Family suppor t is a fur ther determinant factor that has a positive correlation to the Qo L.
基金supported by the National Natural Science Foundation of China(82274313)Key R&D Program of Shaanxi Province(2023GHZD43)the National Natural Science Foundation of China(81870284).
文摘Background:Formononetin(FMN)has beneficial effects in cardiovascular diseases but its functions and mechanisms in heart failure with preserved ejection fraction(HFpEF)remain unclear.This study aimed at determining whether FMN ameliorated HFpEF-induced cardiac dysfunction and exploring its underlying mechanisms.Methods:The mouse model of HFpEF was established through uninephrectomy surgery and d-aldosterone infusion in C57BL/6 mice.Cardiac remodeling and potential mechanisms of FMN in HFpEF were assessed by histological analysis,immunofluorescence,echocardiography,real-time PCR and western blotting sequentially.Results:FMN prevented myocardial dysfunction,fibrosis and cardiomyocyte apoptosis.The mRNA levels of left ventricular hypertrophy markers were increased in HFpEF mice but they remained unchanged in FMN-treated mice.In addition,the expression levels of PPARαand PGC-1 were increased in HFpEF mice for FMN treatment.The PPARα-PGC-1 complex affected the expression of fatty acid content and encoded enzymes in glucose metabolism.Both the hypertrophy and metabolic impairment due to FMN in HFpEF mice were alleviated after the addition of PPARαantagonist GW6471.Conclusion:In conclusion,FMN could prevent the cardiac hypertrophy in HFpEF mice by activating the PPARα/PGC-1 pathway and regulating energy metabolism,which provides a new therapeutic strategy for HFpEF patients.
文摘Heart failure with preserved ejection fraction(HFpEF)is a clinical syndrome characterized by symptoms and sings of heart failure with elevated left ventricular filling pressures at rest or during exercise.It is the most common type of heart failure in the elderly and its prevalence increases with age and is higher in females at any given age.HFpEF is frequently accompanied of comorbid conditions such as diabetes mellitus,obesity,atrial fibrillation and renal dysfunction.The diagnosis relies in the integration of clinical information,laboratory data and interpretation of cardiac imaging and hemodynamic findings at rest and during exercise.Conditions that have a specific treatment such as coronary artery disease,valvular disease,cardiac amyloidosis and constrictive pericarditis should be considered and evaluated as appropriate.Aggressive management of comorbidities,optimization of blood pressure control and volume status using diuretics as needed are among the current treatment recommendations.There are no specific therapies that have shown to decrease mortality in HFpEF.In symptomatic patients with history of hospital admission for decompensated heart failure,the implantation of a wireless pulmonary artery pressure monitor should be considered.Finally,given the high mortality of this condition,goals of care discussion should be initiated early and involvement of palliative care medicine should be considered.
基金Supported by The European Union,Biomar Ca RE,No.HEALTH-2011-278913
文摘micro RNAs(mi RNAs) are powerful regulators of posttranscriptional gene expression and play an important role in pathophysiological processes. Circulating mi RNAs can be quantified in body liquids and are promising biomarkers in numerous diseases. In cardiovascular disease mi RNAs have been proven to be reliable diagnostic biomarkers for different disease entities. In cardiac fibrosis(CF) and heart failure(HF) dysregulated circulating mi RNAs have been identified,indicating their promising applicability as diagnostic biomarkers. Some mi RNAs were successfully tested in risk stratification of HF implementing their potential use as prognostic biomarkers. In this respect mi RNAs might soon be implemented in diagnostic clinical routine. In the young field of mi RNA based research advances have been made in identifying mi RNAs as potential targets for the treatment of experimental CF and HF. Promising study results suggest their potential future application as therapeutic agents in treatment of cardiovascular disease. This article summarizes the current state of the various aspects of mi RNA research in the field of CF and HF with reduced ejection fraction as well as preserved ejection fraction. The review provides an overview of the application of circulating mi RNAs as biomarkers in CF and HF and current approaches to therapeutically utilize mi RNAs in this field of cardiovascular disease.
文摘Heart failure with preserved ejection fraction(HFPEF)is common and represents a major challenge in cardiovascular medicine.Most of the current treatment of HFPEF is based on morbidity benefits and symptom reduction.Various pharmacological interventions available for heart failure with reduced ejection fraction have not been supported by clinical studies for HFPEF.Addressing the specific aetiology and aggressive risk factor modification remain the mainstay in the treatment of HFPEF.We present a brief overview of the currently recommended therapeutic options with available evidence.
基金supported by the Science Foundation of the National Natural Science Foundation of China(Nos.51634001and 51774023)the Fundamental Research Funds for the Central Universities of China(No.FRF-TP-18-007C1)
文摘In this study,we established a dynamic ejection coal burst model for a coalmine roadway subject to stress,and held that the stress concentration zone at the roadway side is the direct energy source of this ejection.The formation and development of such burst undergoes three stages:(1)instability and propagation of the cracks in the stress concentration zone,(2)emerging of a layered energy storage structure in the zone,and(3)ejection of coal mass or coal burst due to instability.Moreover,we figured out the initial strength of periodic cracks is parallel to the maximal dominant stress direction in the stress concentration zone and derived from the damage strain energy within the finite area of the zone based on the Griffith energy theory.In addition,we analyzed the formation process of the layered energy storage structure in the zone,simplified it as a simply supported restraint sheet,and calculated the minimum critical load and the internally accumulated elastic energy at the instable state.Furthermore,we established a criterion for occurrence of the coal burst based on the variational principle,and analyzed the coal mass ejection due to instability and coal burst induced by different intensity disturbances.At last,with the stratum conditions of Junde Coalmine as the model prototype,we numerically simulated the load displacement distribution of the stress concentration zone ahead of the working face disturbed by the main roof-fracture-induced dynamic load during the mining process as well as their varying characteristics,and qualitatively verified the above model.
文摘Heart failure(HF) is the leading cause of hospitalization among older adults and the prevalence is growing with the aging populations in the Western countries. Epidemiologic reports suggest that approximately 50% of patients who have signs or symptoms of HF have preserved left ventricular ejection fraction. This HF type predominantly affects women and the elderly with other co-morbidities, such as diabetes, hypertension, and overt volume status. Most of the current treatment strategies are based on morbidity benefits such as quality of life and reduction of clinical HF symptoms. Treatment of patients with HF with preserved ejection fraction displayed disappointing results from several large randomized controlled trials. The heterogeneity of HF with preserved ejection fraction, understood as complex syndrome, seems to be one of the primary reasons. Here, we present an overview of the current management strategies with available evidence and new therapeutic approach from drugs currently in clinical trials, which target diastolic dysfunction, chronotropic incompetence, and risk factor management. We provide an outline and interpretation of recent clinical trials that failed to improve outcome and survival in patients with HF with preserved ejection fraction.
文摘Left ventricular ejection fraction(LVEF)is an impor-tant predictor of cardiac outcome and helps in makingimportant diagnostic and therapeutic decisions suchas the treatment of different types of congestive heartfailure or implantation of devices like cardiac resynchro-nization therapy-defibrillator.LVEF can be measuredby various techniques such as transthoracic echo-cardiography,contrast ventriculography,radionuclidetechniques,cardiac magnetic resonance imaging andcardiac computed tomographic angiography(CTA).Thedevelopment of cardiac CTA using multi-detector rowCT(MDCT)has seen a very rapid improvement in thetechnology for identifying coronary artery stenosis andcoronary artery disease in the last decade.During theacquisition,processing and analysis of data to studycoronary anatomy,MDCT provides a unique opportunityto measure left ventricular volumes and LVEF simulta-neously with the same data set without the need foradditional contrast or radiation exposure.The develop-ment of semi-automated and automated software to measure LVEF has now added uniformity,efficiency and reproducibility of practical value in clinical practice rather than just being a research tool.This article will address the feasibility,the accuracy and the limitations of MDCT in measuring LVEF.
基金Project supported by the Natural Science Foundation of Jiangsu Province,China(Grant No.KYLX 0341)the National Natural Science Foundation of China(Grant No.61405147)
文摘In pulsed laser drilling, melt ejection greatly influences the keyhole shape and its quality as well, but its mechanism has not been well understood. In this paper, numerical simulation and experimental investigations based on 304 stainless steel and aluminum targets are performed to study the effects of material parameters on melt ejection. The numerical method is employed to predict the temperatures, velocity fields in the solid, liquid, and vapour front, and melt pool dynamics of targets as well. The experimental methods include the shadow-graphic technique, weight method, and optical microscope imaging, which are applied to real-time observations of melt ejection phenomena, measurements of collected melt and changes of target mass, observations of surface morphology and the cross-section of the keyhole, respectively. Numerical and experimental results show that the metallic material with high thermal diffusivity like aluminum is prone to have a thick liquid zone and a large quantity of melt ejection. Additionally, to the best of our knowledge, the liquid zone is used to illustrate the relations between melt ejection and material thermal diffusivity for the first time. The research result in this paper is useful for manufacturing optimization and quality control in laser-material interaction.
基金supported by the he National Natural Science Foundation of China (No. 81770441, No. 81700398, No. 81970309)Nanjing Municipal Healthcare Grant YKK16127
文摘Background Endogenous aldehyde damages DNA and potentiates an ageing phenotype. The aldehyde dehydrogenase 2(ALDH2) rs671 polymorphism has a prevalence of 30%–50% in Asian populations. In this study, we aimed to analyze risk factors contributing to the development of heart failure with preserved ejection fraction(HFpEF) along with the genetic exposure in Chinese patients hospitalized with cardiovascular diseases(CVD). Methods From July 2017 to October 2018, a total of 770 consecutive Chinese patients with normal left ventricular ejection fractions(LVEF) and established CVD(hypertension, coronary heart diseases, or diabetes) were enrolled in this prospective cross-sectional study. HFpEF was defined by the presence of at least one of symptom(dyspnoea and fatigue) or sign(rales and ankle swelling) related to heart failure;N-terminal pro-B-Type natriuretic peptide(NT pro-BNP ≥ 280 pg/mL);LVEF ≥ 50%;and at least one criterion related to elevated ventricular filling pressure or diastolic dysfunction(left atrial diameter > 40 mm, E/E’ ≥ 13, E’/A’ < 1 or concurrent atrial fibrillation). Logistic regression was performed to yield adjusted odds ratios(ORs) for HFp EF incidence associated with traditional and/or genetic exposures. Results Finally, among 770 patients with CVD, 92(11.9%) patients were classified into the HFpEF group according to the diagnostic criteria. The mean age of the participants was 67 ± 12 years, and 278(36.1%) patients were females. A total of 303(39.4%) patients were ALDH2*2 variant carriers. In the univariate analysis, eight exposures were found to be associated with HFpEF: atrial fibrillation, ALDH2*2 variants, hypertension, age, anaemia, smoking, alcohol consumption and sex. Multivariable logistic regression showed that 4 ‘A’ variables(atrial fibrillation, ALDH2*2 variants, age and anaemia) were significantly associated with an increased risk of HFpEF. Atrial fibrillation was associated with a 3.8-fold increased HFpEF risk(95% CI: 2.21–6.61, P < 0.001), and the other three exposures associated with increased HFpEF risk were the ALDH2*2 variant(OR = 2.41, 95% CI: 1.49–3.87, P < 0.001), age(OR = 2.14, 95% CI: 1.27–3.60, P = 0.004), and anaemia(OR = 1.79, 95% CI: 1.05–3.03, P = 0.032). These four variables predicted HFpEF incidence in Chinese CVD patients(C-statistic = 0.745, 95% CI: 0.691–0.800, P < 0.001). Conclusions 4 A traits(atrial fibrillation, ALDH2*2 variants, age and anaemia) were associated with an increased risk of HFpEF in Chinese CVD patients. Our results provide potential clues to the aetiology, pathophysiology and therapeutic targets of HFpEF.
基金Supported by the Aeronautical Science Foundation of China(2012ZC52035)
文摘The parachute container cover ejection separation is the first and foremost motion for the return capsule recovery system,which is related to the success of a recovery system.Adopting the computational fluid dynamics(CFD)simulation and flight dynamics coupling method,the parachute container cover ejection separation is simulated.The rationality of the ejection separation speed and dynamic characteristics of the separation process is analyzed.Meanwhile,the influences of angle of attack,Mach number and ejection separation speed on the parachute container cover ejection are also investigated.Results show that the ejection separation speed design is reasonable.It has a certain design margin for parachute container cover to escape from the wake region,and to pull out the drag parachute completely.The results may provide a theoretical basis for recovery system engineering design of the lunar exploration project.
