Anew method in system design of ejecting devices of missiles is first presented.Some important points are dis-cussed,which guid the research and development of new ejecting devices of missileg,amd provid the foundatio...Anew method in system design of ejecting devices of missiles is first presented.Some important points are dis-cussed,which guid the research and development of new ejecting devices of missileg,amd provid the foundation flr thw design of mew ejecting device is provided.The system design includes the distribution of techmology specifica-tion,3-D solid modeling of ejecting devices of missiles im-ported from abroad,the design of pmeumatic device sys-tem,the design of ejecting mechanism system,the predic-tion of reliability and the experimental analysis,etc.展开更多
Spray cooling has proved its superior heat transfer performance in removing high heat flux for ground applications. However, the dissipation of vapor liquid mixture from the heat sur- face and the closed-loop circulat...Spray cooling has proved its superior heat transfer performance in removing high heat flux for ground applications. However, the dissipation of vapor liquid mixture from the heat sur- face and the closed-loop circulation of the coolant are two challenges in reduced or zero gravity space enviromnents. In this paper, an ejected spray cooling system for space closed-loop application was proposed and the negative pressure in the ejected condenser chamber was applied to sucking the two-phase mixture from the spray chamber. Its ground experimental setup was built and exper- imental investigations on the smooth circle heat surface with a diameter of 5 mm were conducted with distilled water as the coolant spraying from a nozzle of 0.51 mm orifice diameter at the inlet temperatures of 69.2 ℃ and 78.2 ℃ under the conditions of heat flux ranging from 69.76 W/cm2 to 311.45 W/cm2, volume flow through the spray nozzle varying from 11,22 L：h to 15.76 L·h. Work performance of the spray nozzle and heat transfer performance of the spray cooling system were analyzed; results show that this ejected spray cooling system has a good heat transfer performance and provides valid foundation for space closed-loop application in the near future.展开更多
BACKGROUND Left bundle branch pacing(LBBP)is a novel pacing modality of cardiac resynchronization therapy(CRT)that achieves more physiologic native ventricular activation than biventricular pacing(BiVP).AIM To explore...BACKGROUND Left bundle branch pacing(LBBP)is a novel pacing modality of cardiac resynchronization therapy(CRT)that achieves more physiologic native ventricular activation than biventricular pacing(BiVP).AIM To explore the validity of electromechanical resynchronization,clinical and echocardiographic response of LBBP-CRT.METHODS Systematic review and Meta-analysis were conducted in accordance with the standard guidelines as mentioned in detail in the methodology section.RESULTS In our analysis,the success rate of LBBP-CRT was determined to be 91.1%.LBBP CRT significantly shortened QRS duration,with significant improvement in echocardiographic parameters,including left ventricular ejection fraction,left ventricular end-diastolic diameter and left ventricular end-systolic diameter in comparison with BiVP-CRT.CONCLUSION A significant reduction in New York Heart Association class and B-type natriuretic peptide levels was also observed in the LBBP-CRT group vs BiVP-CRT group.Lastly,the LBBP-CRT cohort had a reduced pacing threshold at follow-up as compared to BiVP-CRT.展开更多
A vertical current sheet is a crucial element in many flare/coronal mass ejection （CME） models. For the first time, Liu et al. reported a vertical current sheet directly imaged during the flare rising phase with the...A vertical current sheet is a crucial element in many flare/coronal mass ejection （CME） models. For the first time, Liu et al. reported a vertical current sheet directly imaged during the flare rising phase with the EUV Imaging Telescope （EIT） onboard the Solar and Heliospheric Observatory （SOHO）. As a follow-up study, here we present the comprehensive analysis and detailed physical interpretation of the observation. The current sheet formed due to the gradual rise of a transequatorial loop system. As the loop legs approached each other, plasma flew at - 6 km s^-1 into a local area where a cusp-shaped flare loop subsequently formed and the current sheet was seen as a bright, collimated structure of global length （_〉 0.25 RQ） and macroscopic width （（5-10）× 10^3 km）, extending from 50 Mm above the flaring loop to the border of the EIT field of view （FOV）. The reconnection rate in terms of the Alfven Mach number is estimated to be only 0.005-0.009, albeit a halo CME was accelerated from - 400 km s- 1 to - 1300 km s- 1 within the coronagraph FOV. Drifting pulsating structures at metric frequencies were recorded during the impulsive phase, implying tearing of the current sheet in the high corona. A radio Type III burst occurred when the current sheet was clearly seen in EUV, indicative of accelerated electrons beam- ing upward from the upper tip of the current sheet. A cusp-shaped dimming region was observed to be located above the post-flare arcade during the decay phase in EIT; both the arcade and the dimming expanded with time. With the Coronal Diagnostic Spectrometer （CDS） aboard SOHO, a clear signature of chromospheric evaporation was seen during the decay phase, i.e., the cusp-shaped dimming region was associ- ated with plasma upflows detected with EUV hot emission lines, while the post-flare loop was associated with downflows detected with cold lines. This event provides a comprehensive view of the reconnection geometry and dynamics in the solar corona.展开更多
Objective To evaluate the effects of BQ-123 on cardiac function and ventricular remodelling after coronary microembolization (CME) in rats. Methods We created a rat model of CME by injecting a suspension of autogenic ...Objective To evaluate the effects of BQ-123 on cardiac function and ventricular remodelling after coronary microembolization (CME) in rats. Methods We created a rat model of CME by injecting a suspension of autogenic microthrombotic particles into left ventricle. Three days after the procedure, the 30 surviving rats were randomly divided into 3 groups, each consisted of 10 rats: sham-operation group(SO), CME model group(CM) and BQ-123 intervention group(BQ). Rats in the BQ group received BQ-123 (400μg/kg per day, intraperitoneally) for 4 weeks. Plasma and myocardial endothelin-1 (ET-1) were measured by radioimmunoassay. And serial echocardiography was performed to monitor alterations of left ventricular end-systolic and end-diastolic diameter (LVESD, LVEED), and left ventricular short-axis fraction shortening(LVFS) and ejection fraction (LVEF), and physiologicography to document the changes of left ventricular systolic pressure (LVSP) and end-diastolic pressure pressure(LVEDP), and left ventricular maximum positive and negative dp/dt (±LVdp/dtmax). Results Compared with sham-operated group, both LVEDD and LVESD were increased (P【0.01), whereas LVFS and LVEF were significantly decreased (P【0.01) in CME group; LVEDP was markedly increased, while LVSP and±LVdp/ dtmax markedly reduced in CME group (P【0.01); plasma and tissue ET-1 levels increased in CME group (P【0.01). BQ-123 intervention significantly decreased both the plasma and tissue ET-1 levels (P【0.01), and markedly increased LVFS and LVEF, with significant improvement of LVSP and±LVdp/ dtmax (P【0.01). Conclusions Treatment with BQ-123 prevents ventricular remodeling after CME due to suppression of the endothelin system.展开更多
A code-generation and recognition technology that uses a modified ejection system in the diecasting process is presented.To achieve the highest level of quality management,the first requirement in the manufacturing pr...A code-generation and recognition technology that uses a modified ejection system in the diecasting process is presented.To achieve the highest level of quality management,the first requirement in the manufacturing process is to establish a product management system according to the specific product unit.Thus,a method to individually identify each product,such as a barcode or QR code,is required during the production process.Products manufactured in the die-casting process always have ejector pin(EP)marks.Herein,an ejection system was modified to generate a unique code using EP marks.This ejection system has two features:an EP with a modified head to show the direction of rotation,and a function to dependently rotate EPs(five or six EPs)with a constant angle.The EPs are numbered according to the rotation angle.Thus,the EP marks can be viewed as a five-or six-digit code.A program was also developed to individually identify the products by automatically detecting and reading the EPs using deep learning-based object detection and classification technology.展开更多
BACKGROUND Gliflozins or Sodium glucose cotransporter 2 inhibitors(SGLT2i)are relatively novel antidiabetic medications that have recently been shown to represent favorable effects on patients’cardiorenal outcomes.Ho...BACKGROUND Gliflozins or Sodium glucose cotransporter 2 inhibitors(SGLT2i)are relatively novel antidiabetic medications that have recently been shown to represent favorable effects on patients’cardiorenal outcomes.However,there is shortage of data on potential disparities in this therapeutic effect across different patient subpopulations.AIM To investigate differential effects of SGLT2i on the cardiorenal outcomes of heart failure patients across left ventricular ejection fraction(LVEF)levels.METHODS Literature was searched systematically for the large randomized double-blind controlled trials with long enough follow up periods reporting cardiovascular and renal outcomes in their patients regarding heart failure status and LVEF levels.Data were then meta-analyzed after stratification of the pooled data across the LVEF strata and New York Heart Associations(NYHA)classifications for heart failure using Stata software version 17.0.RESULTS The literature search returned 13 Large clinical trials and 13 post hoc analysis reports.Meta-analysis of the effects of gliflozins on the primary composite outcome showed no significant difference in efficacy across the heart failure subtypes,but higher efficacy were detected in patient groups at lower NYHA classifications(I2=46%,P=0.02).Meta-analyses across the LVEF stratums revealed that a baseline LVEF lower than 30%was associated with enhanced improvement in the primary composite outcome compared to patients with higher LVEF levels at the borderline statistical significance(HR:0.70,95%CI:0.60 to 0.79 vs 0.81,95%CI:0.75 to 0.87;respectively,P=0.06).Composite renal outcome was improved significantly higher in patients with no heart failure than in heart failure patients with preserved ejection fraction(HFpEF)(HR:0.60,95%CI:0.49 to 0.72 vs 0.94,95%CI:0.74 to 1.13;P=0.04).Acute renal injury occurred significantly less frequently in heart failure patients with reduced ejection fraction who received gliflozins than in HFpEF(HR:0.67,95%CI:51 to 0.82 vs 0.94,95%CI:0.82 to 1.06;P=0.01).Volume depletion was consistently increased in response to SGLT2i in all the subgroups.CONCLUSION Heart failure patients with lower LVEF and lower NYHA sub-classifications were found to be generally more likely to benefit from therapy with gliflozins.Further research are required to identify patient subgroups representing the highest benefits or adverse events in response to SGLT2i.展开更多
Background:Concerns have been raised about the efficacy of intravenous immunoglobulin and corticosteroids in pediatric myocarditis;however,the relationship between the risk and efficacy of these two therapies in child...Background:Concerns have been raised about the efficacy of intravenous immunoglobulin and corticosteroids in pediatric myocarditis;however,the relationship between the risk and efficacy of these two therapies in children with myocarditis varies.Methods:A systematic review on seventeen studies was conducted in July 2020,which included 1,960 subjects at the baseline,with 788 receiving intravenous immunoglobulin and 142 receiving corticosteroids.The mean difference(MD)or odds ratio(OR)with 95%confidence intervals(Cis)was calculated to assess the prognostic role of both treatments using dichotomous and continuous methods with random or fixed-effect models.Results:The use of intravenous immunoglobulin was significantly associated with a lower mortality rate or heart transplantation in children with myocarditis(OR,0.55;95%CI,0.40-0.77,^<0.001)compared with the control group.However,corticosteroids were not significantly associated with the same parameters(OR,0.72;95% CI,0.31-1.63,p=0.43).The use of intravenous immunoglobulin was not significantly related to improving left ventricular ejection in children with myocarditis(OR,2.30;95% CI,-9.65-14.25,p=0.71)and so were corticosteroids(MD,5.17;95% CI,-0.26-10.60,p=0.06).Conclusion:The use of intravenous immunoglobulin might have an independent risk relationship with a lower mortality rate or heart transplantation and is recommended in children with myocarditis to prevent complications.展开更多
In this paper,we perform a follow-up investigation of the solar eruption originating from active region 13575 on 2024 February 9.The primary eruption of a hot channel generates an X3.4 class flare,a full-halo coronal ...In this paper,we perform a follow-up investigation of the solar eruption originating from active region 13575 on 2024 February 9.The primary eruption of a hot channel generates an X3.4 class flare,a full-halo coronal mass ejection(CME),and an extreme-ultraviolet(EUV)wave.Interaction between the wave and a quiescent prominence(QP)leads to a large-amplitude,transverse oscillation of QP.After the transverse oscillation,QP loses equilibrium and rises up.The ascending motion of the prominence is coherently detected and tracked up to∼1.68 R_(⊙)by the Solar UltraViolet Imager onboard the GOES-16 spacecraft and up to∼2.2 R_(⊙)by the Solar Corona Imager(SCI_UV)of the LyαSolar Telescope onboard the ASO-S spacecraft.The velocity increases linearly from 12.3 to 68.5 km s^(−1)at 18:30 UT.The sympathetic eruption of QP drives the second CME with a typical three-part structure.The bright core comes from the eruptive prominence,which could be further observed up to∼3.3 R_(⊙) by the Large Angle Spectroscopic Coronagraph onboard the Solar and Heliospheric Observatory mission.The leading edge of the second CME accelerates continuously from∼120 to∼277 km s^(−1).The EUV wave plays an important role in linking the primary eruption with the sympathetic eruption.展开更多
Objective:In addition to dyspnea and edema,gastrointestinal discomfort is common among patients with heart failure(HF).Reduced cardiac output can lead to inadequate perfusion of the intestinal mucosa and subsequent im...Objective:In addition to dyspnea and edema,gastrointestinal discomfort is common among patients with heart failure(HF).Reduced cardiac output can lead to inadequate perfusion of the intestinal mucosa and subsequent impairment of the intestinal barrier.Levosimendan,a novel inotropic agent,binds to cardiac troponin C to enhance calcium sensitivity,activates ATP-dependent potassium channels in cardiomyocytes and vascular smooth muscle cells,exerts positive inotropic and vasodilatory effects,and reduces free radical generation,thereby improving systemic hemodynamics including intestinal circulation.However,clinical evidence regarding its protective effects on the intestinal barrier in HF patients remains limited,and the underlying mechanisms require further clarification.This study aims to investigate whether levosimendan confers protective effects on the intestinal barrier in HF patients and to explore its potential mechanisms.Methods:Network pharmacology was first used to analyze potential mechanisms of levosimendan in treating intestinal barrier dysfunction among HF patients.A total of 62 hospitalized patients with acute exacerbation of HF with reduced ejection fraction(HFrEF)were enrolled based on echocardiographic left ventricular ejection fraction.According to clinical medication regimens,patients were assigned to a conventional treatment group(n=31)or a levosimendan treatment group(n=31).The conventional treatment group received standard anti-HF therapy,while the levosimendan treatment group received levosimendan in addition to standard therapy.Enzyme-linked immunosorbent assays were used to measure plasma levels and changes in the intestinal-barrier proteins zonulin,intestinal fatty acid binding protein(I-FABP),proinflammatory cytokines[interleukin(IL)-17,IL-6,and tumor necrosis factor(TNF)-α],anti-inflammatory cytokine IL-10,and N-terminal probrain natriuretic peptide(NT-proBNP).Improvements in cardiac function and gastrointestinal symptoms were evaluated using the Kansas City Cardiomyopathy Questionnaire(KCCQ)and the Gastrointestinal Symptom Rating Scale(GSRS).Results:Network pharmacology indicated that the effects of levosimendan on intestinal barrier dysfunction in HF patients may involve inflammation-related pathways such as IL-17 and TNF.Clinically,after treatment,zonulin decreased by 32.94 ng/mL in the levosimendan treatment group versus 15.05 ng/mL in the conventional treatment group(P<0.05).I-FABP decreased by 6.97 pg/mL in the levosimendan treatment group but increased by 35.16 pg/mL in the conventional treatment group(P<0.05).IL-6,IL-17,and TNF-αdecreased by 1.11 pg/mL,1.21 pg/mL,and 2.83 pg/mL,respectively,in the levosimendan treatment group,whereas they increased by 7.68 pg/mL,0.67 pg/mL,and 2.38 pg/mL in the conventional treatment group(all P<0.05).IL-10 decreased by 24.48 pg/mL in the conventional treatment group but increased by 24.98 pg/mL in the levosimendan treatment group(P<0.05).NT-proBNP increased by 7.35 pg/mL in the conventional treatment group but decreased by 4.73 pg/mL in the levosimendan treatment group(P<0.05).KCCQ scores increased by 0.36 in the conventional treatment group and 1.86 in the levosimendan treatment group,GSRS scores decreased by 1.00 in the conventional treatment group and 2.40 in the levosimendan treatment group,respectively,but the differences were not statistically significant(both P>0.05).Conclusion:Levosimendan not only improves HF and gastrointestinal symptoms in hospitalized patients with acute exacerbation of HFrEF but also reduces plasma intestinal barrier factor levels.These effects may be associated with decreased plasma proinflammatory cytokines and increased anti-inflammatory cytokines after treatment,potentially involving IL-17 and TNF signaling pathways.展开更多
Clinical guidelines typically classify heart failure(HF)into three categories based on left ventricular ejection fraction(LVEF):reduced(HFr EF),mildly reduced(HFmr EF),and preserved(HFp EF).[1]Sodium-glucose co-transp...Clinical guidelines typically classify heart failure(HF)into three categories based on left ventricular ejection fraction(LVEF):reduced(HFr EF),mildly reduced(HFmr EF),and preserved(HFp EF).[1]Sodium-glucose co-transporter 2(SGLT2)inhibitors have been demonstrated to lower cardiovascular mortality and HF events.The EMPEROR trials indicated similar efficacy and safety for SGLT2 inhibitors compared to placebo in outpatients with HFrEF as well as HFmrEF and HFpEF.展开更多
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
We present an analysis of the magnetic mechanism of an X6.4-class confined flare in NOAA Active Region(AR)13590 on 2024 February 22.Despite a pre-existing magnetic flux rope(MFR)embedded within a null-point topology,t...We present an analysis of the magnetic mechanism of an X6.4-class confined flare in NOAA Active Region(AR)13590 on 2024 February 22.Despite a pre-existing magnetic flux rope(MFR)embedded within a null-point topology,the flare produced only a localized jet without an associated coronal mass ejection.Using data from the Solar Dynamics Observatory and nonlinear force-free field extrapolations,we traced the formation and evolution of the MFR,which developed under photospheric shearing motions but remained weakly twisted(with twist number being lower than 1.3)and below the thresholds for kink instability.Meanwhile,the MFR is located at heights where the decay index(n≤1.0)of the overlying field was insufficient to trigger torus instability.Furthermore,we calculated two important parameters measuring the non-potentiality of the AR,one is the ratio of the free energy to the potential-field energy,and the other is the ratio of the non-potential helicity to the square of the magnetic flux.Both the two parameters were significantly lower than critical values for eruptive flares.These factors,combined with the stabilizing influence of the strong overlying field,confined the MFR and limited the eruption to a jet.Our findings highlight the importance of both local magnetic properties and global energy constraints in determining the eruptive potential of solar flares.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
Heart failure(HF)has emerged as one of the foremost global health threats due to its intricate pathophysiological mechanisms and multifactorial etiology.Adeno-sine triphosphate(ATP)-induced cell death represents a nov...Heart failure(HF)has emerged as one of the foremost global health threats due to its intricate pathophysiological mechanisms and multifactorial etiology.Adeno-sine triphosphate(ATP)-induced cell death represents a novel form of regulated cell deaths,marked by cellular energy depletion and metabolic dysregulation stemming from excessive ATP accumulation,identifying its uniqueness compared to other cell death processes modalities such as programmed cell death and necrosis.Growing evidence suggests that ATP-induced cell death(AICD)is predominantly governed by various biological pathways,including energy meta-bolism,redox homeostasis and intracellular calcium equilibrium.Recent research has shown that AICD is crucial in HF induced by pathological conditions like myocardial infarction,ischemia-reperfusion injury,and chemotherapy.Thus,it is essential to investigate the function of AICD in the pathogenesis of HF,as this may provide a foundation for the development of targeted therapies and novel treatment strategies.This review synthesizes current advancements in under-standing the link between AICD and HF,while further elucidating its invol-vement in cardiac remodeling and HF progression.展开更多
BACKGROUND Heart failure with preserved ejection fraction(HFpEF)accounts for approximately half of heart failure cases and is associated with high morbidity and mortality.Beta-blockers(BB)and calcium channel blockers(...BACKGROUND Heart failure with preserved ejection fraction(HFpEF)accounts for approximately half of heart failure cases and is associated with high morbidity and mortality.Beta-blockers(BB)and calcium channel blockers(CCB)are commonly used for symptom control and comorbidity management,but their comparative effectiveness and safety remain unclear.AIM To compare the effectiveness and safety of BB vs CCB in patients with HFpEF using simulated real-world data and propensity score-matched analyses.METHODS Simulated data for 4000 HFpEF patients(2000 BB,2000 CCB)were generated based on distributions extracted from electronic medical records spanning 2014-2023.Inclusion criteria included adults with left ventricular ejection fraction≥50%and initiation of BB or CCB.Effectiveness outcomes encompassed mortality,heart failure hospitalizations,and changes in clinical parameters.Safety outcomes included bradycardia,hypotension,and drug discontinuation.Statistical analyses used t-tests,χ2 tests,Cox proportional hazards models for hazard ratios(HR),and incidence rate ratios(IRR)in R software.Propensity score matching(PSM)was performed to balance baseline characteristics,with outcomes reassessed in the matched cohort.RESULTS Baseline characteristics were largely balanced,with minor differences in sex,chronic kidney disease,systolic blood pressure,and left atrial volume index.BB demonstrated lower all-cause mortality(crude HR 0.78,95%CI:0.70-0.87,P=0.003),heart failure hospitalization(crude HR 0.86,95%CI:0.77-0.96,P=0.031),and composite endpoint(crude HR 0.85,95%CI:0.79-0.91,P<0.001)rates compared to CCB.IRR for heart failure hospitalizations and emergency visits favored BB.Safety profiles showed higher symptomatic bradycardia(9.2%vs 4.9%,P<0.001)and drug discontinuation(11.3%vs 9.3%,P=0.043)with BB,and higher hypotension(7.2%vs 11.5%,P<0.001)with CCB.Matched analyses showed all-cause mortality rates of 0.0622 per person-year for BB vs 0.0649 for CCB(HR 0.96,95%CI:0.85-1.08),heart failure hospitalization rates of 0.0751 vs 0.0888(HR 0.84,95%CI:0.75-0.94),and IRR for number of heart failure hospitalizations of 1.65 for CCB vs BB(95%CI:1.51-1.80,P<0.001).CONCLUSION BB may offer potential advantages in reducing mortality and hospitalizations in HFpEF compared to CCB,with distinct safety considerations.PSM confirmed these trends with reduced confounding.Personalized therapy is recommended,warranting prospective trials for validation.展开更多
Major solar plasma disturbances are subjected to Lomb-Scargle periodogram and wavelet analysis to determine the occurrence frequency.These disruptions include interplanetary coronal mass ejection,sudden storm commence...Major solar plasma disturbances are subjected to Lomb-Scargle periodogram and wavelet analysis to determine the occurrence frequency.These disruptions include interplanetary coronal mass ejection,sudden storm commencement,high-speed streams,corotating interaction regions,interplanetary shocks and Forbush decreases.We included information on all of the aforementioned solar disturbances for the last six solar cycles,from 1965 to 2023,for this study.Our findings reveal some intriguing and noteworthy results that clearly distinguish between even and odd-numbered solar cycles.The study suggests that the Sun behaves differently in odd and even-numbered solar cycles as it comes from the massive solar eruptions.During even-numbered solar cycles,variations with a period of∼44 days are prominently observed in addition to solar rotation(∼27 days)and extended solar(∼36 days)rotation.However,in addition to solar rotation,prolonged solar rotation,and periods of around 44 days,we also detect a number of intermittent changes with nearly comparable amplitude during the oddnumbered solar cycles.The findings also demonstrate that,in contrast to odd-numbered solar cycles,the emissions rate of these disruptions is more distinct and predictable during even-numbered solar cycles.展开更多
文摘Anew method in system design of ejecting devices of missiles is first presented.Some important points are dis-cussed,which guid the research and development of new ejecting devices of missileg,amd provid the foundation flr thw design of mew ejecting device is provided.The system design includes the distribution of techmology specifica-tion,3-D solid modeling of ejecting devices of missiles im-ported from abroad,the design of pmeumatic device sys-tem,the design of ejecting mechanism system,the predic-tion of reliability and the experimental analysis,etc.
基金supported by the National Natural Science Foundation of China(No.50506003)
文摘Spray cooling has proved its superior heat transfer performance in removing high heat flux for ground applications. However, the dissipation of vapor liquid mixture from the heat sur- face and the closed-loop circulation of the coolant are two challenges in reduced or zero gravity space enviromnents. In this paper, an ejected spray cooling system for space closed-loop application was proposed and the negative pressure in the ejected condenser chamber was applied to sucking the two-phase mixture from the spray chamber. Its ground experimental setup was built and exper- imental investigations on the smooth circle heat surface with a diameter of 5 mm were conducted with distilled water as the coolant spraying from a nozzle of 0.51 mm orifice diameter at the inlet temperatures of 69.2 ℃ and 78.2 ℃ under the conditions of heat flux ranging from 69.76 W/cm2 to 311.45 W/cm2, volume flow through the spray nozzle varying from 11,22 L：h to 15.76 L·h. Work performance of the spray nozzle and heat transfer performance of the spray cooling system were analyzed; results show that this ejected spray cooling system has a good heat transfer performance and provides valid foundation for space closed-loop application in the near future.
文摘BACKGROUND Left bundle branch pacing(LBBP)is a novel pacing modality of cardiac resynchronization therapy(CRT)that achieves more physiologic native ventricular activation than biventricular pacing(BiVP).AIM To explore the validity of electromechanical resynchronization,clinical and echocardiographic response of LBBP-CRT.METHODS Systematic review and Meta-analysis were conducted in accordance with the standard guidelines as mentioned in detail in the methodology section.RESULTS In our analysis,the success rate of LBBP-CRT was determined to be 91.1%.LBBP CRT significantly shortened QRS duration,with significant improvement in echocardiographic parameters,including left ventricular ejection fraction,left ventricular end-diastolic diameter and left ventricular end-systolic diameter in comparison with BiVP-CRT.CONCLUSION A significant reduction in New York Heart Association class and B-type natriuretic peptide levels was also observed in the LBBP-CRT group vs BiVP-CRT group.Lastly,the LBBP-CRT cohort had a reduced pacing threshold at follow-up as compared to BiVP-CRT.
基金supported by NASA grants NNX08-AJ23G and NNX08-AQ90G.supported by NASA grants NNX08AP88G and NNX09AG10GNSF grant ATM-0849453.supported by NSF grant AST-0908344
文摘A vertical current sheet is a crucial element in many flare/coronal mass ejection （CME） models. For the first time, Liu et al. reported a vertical current sheet directly imaged during the flare rising phase with the EUV Imaging Telescope （EIT） onboard the Solar and Heliospheric Observatory （SOHO）. As a follow-up study, here we present the comprehensive analysis and detailed physical interpretation of the observation. The current sheet formed due to the gradual rise of a transequatorial loop system. As the loop legs approached each other, plasma flew at - 6 km s^-1 into a local area where a cusp-shaped flare loop subsequently formed and the current sheet was seen as a bright, collimated structure of global length （_〉 0.25 RQ） and macroscopic width （（5-10）× 10^3 km）, extending from 50 Mm above the flaring loop to the border of the EIT field of view （FOV）. The reconnection rate in terms of the Alfven Mach number is estimated to be only 0.005-0.009, albeit a halo CME was accelerated from - 400 km s- 1 to - 1300 km s- 1 within the coronagraph FOV. Drifting pulsating structures at metric frequencies were recorded during the impulsive phase, implying tearing of the current sheet in the high corona. A radio Type III burst occurred when the current sheet was clearly seen in EUV, indicative of accelerated electrons beam- ing upward from the upper tip of the current sheet. A cusp-shaped dimming region was observed to be located above the post-flare arcade during the decay phase in EIT; both the arcade and the dimming expanded with time. With the Coronal Diagnostic Spectrometer （CDS） aboard SOHO, a clear signature of chromospheric evaporation was seen during the decay phase, i.e., the cusp-shaped dimming region was associ- ated with plasma upflows detected with EUV hot emission lines, while the post-flare loop was associated with downflows detected with cold lines. This event provides a comprehensive view of the reconnection geometry and dynamics in the solar corona.
文摘Objective To evaluate the effects of BQ-123 on cardiac function and ventricular remodelling after coronary microembolization (CME) in rats. Methods We created a rat model of CME by injecting a suspension of autogenic microthrombotic particles into left ventricle. Three days after the procedure, the 30 surviving rats were randomly divided into 3 groups, each consisted of 10 rats: sham-operation group(SO), CME model group(CM) and BQ-123 intervention group(BQ). Rats in the BQ group received BQ-123 (400μg/kg per day, intraperitoneally) for 4 weeks. Plasma and myocardial endothelin-1 (ET-1) were measured by radioimmunoassay. And serial echocardiography was performed to monitor alterations of left ventricular end-systolic and end-diastolic diameter (LVESD, LVEED), and left ventricular short-axis fraction shortening(LVFS) and ejection fraction (LVEF), and physiologicography to document the changes of left ventricular systolic pressure (LVSP) and end-diastolic pressure pressure(LVEDP), and left ventricular maximum positive and negative dp/dt (±LVdp/dtmax). Results Compared with sham-operated group, both LVEDD and LVESD were increased (P【0.01), whereas LVFS and LVEF were significantly decreased (P【0.01) in CME group; LVEDP was markedly increased, while LVSP and±LVdp/ dtmax markedly reduced in CME group (P【0.01); plasma and tissue ET-1 levels increased in CME group (P【0.01). BQ-123 intervention significantly decreased both the plasma and tissue ET-1 levels (P【0.01), and markedly increased LVFS and LVEF, with significant improvement of LVSP and±LVdp/ dtmax (P【0.01). Conclusions Treatment with BQ-123 prevents ventricular remodeling after CME due to suppression of the endothelin system.
基金the development project of Industrial and Manufacturing Source Technology of the Korea Institute of Industrial Technology(KITECH)granted financial resource by the Ministry of Economy and Finance,Republic of Korea(No.EO190031).
文摘A code-generation and recognition technology that uses a modified ejection system in the diecasting process is presented.To achieve the highest level of quality management,the first requirement in the manufacturing process is to establish a product management system according to the specific product unit.Thus,a method to individually identify each product,such as a barcode or QR code,is required during the production process.Products manufactured in the die-casting process always have ejector pin(EP)marks.Herein,an ejection system was modified to generate a unique code using EP marks.This ejection system has two features:an EP with a modified head to show the direction of rotation,and a function to dependently rotate EPs(five or six EPs)with a constant angle.The EPs are numbered according to the rotation angle.Thus,the EP marks can be viewed as a five-or six-digit code.A program was also developed to individually identify the products by automatically detecting and reading the EPs using deep learning-based object detection and classification technology.
文摘BACKGROUND Gliflozins or Sodium glucose cotransporter 2 inhibitors(SGLT2i)are relatively novel antidiabetic medications that have recently been shown to represent favorable effects on patients’cardiorenal outcomes.However,there is shortage of data on potential disparities in this therapeutic effect across different patient subpopulations.AIM To investigate differential effects of SGLT2i on the cardiorenal outcomes of heart failure patients across left ventricular ejection fraction(LVEF)levels.METHODS Literature was searched systematically for the large randomized double-blind controlled trials with long enough follow up periods reporting cardiovascular and renal outcomes in their patients regarding heart failure status and LVEF levels.Data were then meta-analyzed after stratification of the pooled data across the LVEF strata and New York Heart Associations(NYHA)classifications for heart failure using Stata software version 17.0.RESULTS The literature search returned 13 Large clinical trials and 13 post hoc analysis reports.Meta-analysis of the effects of gliflozins on the primary composite outcome showed no significant difference in efficacy across the heart failure subtypes,but higher efficacy were detected in patient groups at lower NYHA classifications(I2=46%,P=0.02).Meta-analyses across the LVEF stratums revealed that a baseline LVEF lower than 30%was associated with enhanced improvement in the primary composite outcome compared to patients with higher LVEF levels at the borderline statistical significance(HR:0.70,95%CI:0.60 to 0.79 vs 0.81,95%CI:0.75 to 0.87;respectively,P=0.06).Composite renal outcome was improved significantly higher in patients with no heart failure than in heart failure patients with preserved ejection fraction(HFpEF)(HR:0.60,95%CI:0.49 to 0.72 vs 0.94,95%CI:0.74 to 1.13;P=0.04).Acute renal injury occurred significantly less frequently in heart failure patients with reduced ejection fraction who received gliflozins than in HFpEF(HR:0.67,95%CI:51 to 0.82 vs 0.94,95%CI:0.82 to 1.06;P=0.01).Volume depletion was consistently increased in response to SGLT2i in all the subgroups.CONCLUSION Heart failure patients with lower LVEF and lower NYHA sub-classifications were found to be generally more likely to benefit from therapy with gliflozins.Further research are required to identify patient subgroups representing the highest benefits or adverse events in response to SGLT2i.
文摘Background:Concerns have been raised about the efficacy of intravenous immunoglobulin and corticosteroids in pediatric myocarditis;however,the relationship between the risk and efficacy of these two therapies in children with myocarditis varies.Methods:A systematic review on seventeen studies was conducted in July 2020,which included 1,960 subjects at the baseline,with 788 receiving intravenous immunoglobulin and 142 receiving corticosteroids.The mean difference(MD)or odds ratio(OR)with 95%confidence intervals(Cis)was calculated to assess the prognostic role of both treatments using dichotomous and continuous methods with random or fixed-effect models.Results:The use of intravenous immunoglobulin was significantly associated with a lower mortality rate or heart transplantation in children with myocarditis(OR,0.55;95%CI,0.40-0.77,^<0.001)compared with the control group.However,corticosteroids were not significantly associated with the same parameters(OR,0.72;95% CI,0.31-1.63,p=0.43).The use of intravenous immunoglobulin was not significantly related to improving left ventricular ejection in children with myocarditis(OR,2.30;95% CI,-9.65-14.25,p=0.71)and so were corticosteroids(MD,5.17;95% CI,-0.26-10.60,p=0.06).Conclusion:The use of intravenous immunoglobulin might have an independent risk relationship with a lower mortality rate or heart transplantation and is recommended in children with myocarditis to prevent complications.
基金supported by the Strategic Priority Research Program on Space Science,Chinese Academy of Sciencessupported by the National Key R&D Program of China 2022YFF0503003(2022YFF0503000),2021YFA1600500 (2021YFA1600502)+3 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences,grant No.XDB0560000the National Natural Science Foundation of China (NSFC,grant Nos.12373065,12203102,12403064,and 12403068)Natural Science Foundation of Jiangsu Province (BK20231510,BK20241707)Supported by the Specialized Research Fund for State Key Laboratories,and Yunnan Key Laboratory of Solar Physics and Space Science under the grant No.YNSPCC202206
文摘In this paper,we perform a follow-up investigation of the solar eruption originating from active region 13575 on 2024 February 9.The primary eruption of a hot channel generates an X3.4 class flare,a full-halo coronal mass ejection(CME),and an extreme-ultraviolet(EUV)wave.Interaction between the wave and a quiescent prominence(QP)leads to a large-amplitude,transverse oscillation of QP.After the transverse oscillation,QP loses equilibrium and rises up.The ascending motion of the prominence is coherently detected and tracked up to∼1.68 R_(⊙)by the Solar UltraViolet Imager onboard the GOES-16 spacecraft and up to∼2.2 R_(⊙)by the Solar Corona Imager(SCI_UV)of the LyαSolar Telescope onboard the ASO-S spacecraft.The velocity increases linearly from 12.3 to 68.5 km s^(−1)at 18:30 UT.The sympathetic eruption of QP drives the second CME with a typical three-part structure.The bright core comes from the eruptive prominence,which could be further observed up to∼3.3 R_(⊙) by the Large Angle Spectroscopic Coronagraph onboard the Solar and Heliospheric Observatory mission.The leading edge of the second CME accelerates continuously from∼120 to∼277 km s^(−1).The EUV wave plays an important role in linking the primary eruption with the sympathetic eruption.
基金supported by the Hunan Provincial Science and Technology Major Special Fund(2021SK1020)the Natural Science Foundation of Hunan Province(2023JJ30948)+1 种基金the Health Commission of Hunan Province(202203014687)the International Medical Exchange Cardiovascular Multidisciplinary Integrated Thinking Research Foundation(Z-2016-23-2101-20),China.
文摘Objective:In addition to dyspnea and edema,gastrointestinal discomfort is common among patients with heart failure(HF).Reduced cardiac output can lead to inadequate perfusion of the intestinal mucosa and subsequent impairment of the intestinal barrier.Levosimendan,a novel inotropic agent,binds to cardiac troponin C to enhance calcium sensitivity,activates ATP-dependent potassium channels in cardiomyocytes and vascular smooth muscle cells,exerts positive inotropic and vasodilatory effects,and reduces free radical generation,thereby improving systemic hemodynamics including intestinal circulation.However,clinical evidence regarding its protective effects on the intestinal barrier in HF patients remains limited,and the underlying mechanisms require further clarification.This study aims to investigate whether levosimendan confers protective effects on the intestinal barrier in HF patients and to explore its potential mechanisms.Methods:Network pharmacology was first used to analyze potential mechanisms of levosimendan in treating intestinal barrier dysfunction among HF patients.A total of 62 hospitalized patients with acute exacerbation of HF with reduced ejection fraction(HFrEF)were enrolled based on echocardiographic left ventricular ejection fraction.According to clinical medication regimens,patients were assigned to a conventional treatment group(n=31)or a levosimendan treatment group(n=31).The conventional treatment group received standard anti-HF therapy,while the levosimendan treatment group received levosimendan in addition to standard therapy.Enzyme-linked immunosorbent assays were used to measure plasma levels and changes in the intestinal-barrier proteins zonulin,intestinal fatty acid binding protein(I-FABP),proinflammatory cytokines[interleukin(IL)-17,IL-6,and tumor necrosis factor(TNF)-α],anti-inflammatory cytokine IL-10,and N-terminal probrain natriuretic peptide(NT-proBNP).Improvements in cardiac function and gastrointestinal symptoms were evaluated using the Kansas City Cardiomyopathy Questionnaire(KCCQ)and the Gastrointestinal Symptom Rating Scale(GSRS).Results:Network pharmacology indicated that the effects of levosimendan on intestinal barrier dysfunction in HF patients may involve inflammation-related pathways such as IL-17 and TNF.Clinically,after treatment,zonulin decreased by 32.94 ng/mL in the levosimendan treatment group versus 15.05 ng/mL in the conventional treatment group(P<0.05).I-FABP decreased by 6.97 pg/mL in the levosimendan treatment group but increased by 35.16 pg/mL in the conventional treatment group(P<0.05).IL-6,IL-17,and TNF-αdecreased by 1.11 pg/mL,1.21 pg/mL,and 2.83 pg/mL,respectively,in the levosimendan treatment group,whereas they increased by 7.68 pg/mL,0.67 pg/mL,and 2.38 pg/mL in the conventional treatment group(all P<0.05).IL-10 decreased by 24.48 pg/mL in the conventional treatment group but increased by 24.98 pg/mL in the levosimendan treatment group(P<0.05).NT-proBNP increased by 7.35 pg/mL in the conventional treatment group but decreased by 4.73 pg/mL in the levosimendan treatment group(P<0.05).KCCQ scores increased by 0.36 in the conventional treatment group and 1.86 in the levosimendan treatment group,GSRS scores decreased by 1.00 in the conventional treatment group and 2.40 in the levosimendan treatment group,respectively,but the differences were not statistically significant(both P>0.05).Conclusion:Levosimendan not only improves HF and gastrointestinal symptoms in hospitalized patients with acute exacerbation of HFrEF but also reduces plasma intestinal barrier factor levels.These effects may be associated with decreased plasma proinflammatory cytokines and increased anti-inflammatory cytokines after treatment,potentially involving IL-17 and TNF signaling pathways.
基金the National Natural Science Foundation of China(81800250)China Postdoctoral Science Foundation(2022M711417)+3 种基金Jiangsu Province Traditional Chinese Medicine Project(MS2023-137)Yangzhou Science and Technology Plan Social Development Project(YZ2023096)Clinical Trials from the Northern Jiangsu People’s Hospital(SBLC23002)Health Project of Yangzhou Basic Research Program(2024-2-12)。
文摘Clinical guidelines typically classify heart failure(HF)into three categories based on left ventricular ejection fraction(LVEF):reduced(HFr EF),mildly reduced(HFmr EF),and preserved(HFp EF).[1]Sodium-glucose co-transporter 2(SGLT2)inhibitors have been demonstrated to lower cardiovascular mortality and HF events.The EMPEROR trials indicated similar efficacy and safety for SGLT2 inhibitors compared to placebo in outpatients with HFrEF as well as HFmrEF and HFpEF.
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 Guangdong Basic and Applied Basic Research Foundation(2025A1515011353)the Specialized Research Fund for State Key Laboratory of Solar Activity and Space Weather.
文摘We present an analysis of the magnetic mechanism of an X6.4-class confined flare in NOAA Active Region(AR)13590 on 2024 February 22.Despite a pre-existing magnetic flux rope(MFR)embedded within a null-point topology,the flare produced only a localized jet without an associated coronal mass ejection.Using data from the Solar Dynamics Observatory and nonlinear force-free field extrapolations,we traced the formation and evolution of the MFR,which developed under photospheric shearing motions but remained weakly twisted(with twist number being lower than 1.3)and below the thresholds for kink instability.Meanwhile,the MFR is located at heights where the decay index(n≤1.0)of the overlying field was insufficient to trigger torus instability.Furthermore,we calculated two important parameters measuring the non-potentiality of the AR,one is the ratio of the free energy to the potential-field energy,and the other is the ratio of the non-potential helicity to the square of the magnetic flux.Both the two parameters were significantly lower than critical values for eruptive flares.These factors,combined with the stabilizing influence of the strong overlying field,confined the MFR and limited the eruption to a jet.Our findings highlight the importance of both local magnetic properties and global energy constraints in determining the eruptive potential of solar flares.
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Supported by Science and Technology Department of Yunnan Province-Kunming Medical University,Kunming Medical Joint Special Project-Surface Project,No.202401AY070001-164Yunnan Provincial Clinical Research Center Cardiovascular Diseases-New Technology Research for Development Project for Diagnosis and Treatment Cardiovascular Diseases,No.202102AA310002the Key Technology Research and Device Development Project for Innovative Diagnosis and Treatment of Structural Heart Disease in the Southwest Plateau Region,No.202302AA310045.
文摘Heart failure(HF)has emerged as one of the foremost global health threats due to its intricate pathophysiological mechanisms and multifactorial etiology.Adeno-sine triphosphate(ATP)-induced cell death represents a novel form of regulated cell deaths,marked by cellular energy depletion and metabolic dysregulation stemming from excessive ATP accumulation,identifying its uniqueness compared to other cell death processes modalities such as programmed cell death and necrosis.Growing evidence suggests that ATP-induced cell death(AICD)is predominantly governed by various biological pathways,including energy meta-bolism,redox homeostasis and intracellular calcium equilibrium.Recent research has shown that AICD is crucial in HF induced by pathological conditions like myocardial infarction,ischemia-reperfusion injury,and chemotherapy.Thus,it is essential to investigate the function of AICD in the pathogenesis of HF,as this may provide a foundation for the development of targeted therapies and novel treatment strategies.This review synthesizes current advancements in under-standing the link between AICD and HF,while further elucidating its invol-vement in cardiac remodeling and HF progression.
文摘BACKGROUND Heart failure with preserved ejection fraction(HFpEF)accounts for approximately half of heart failure cases and is associated with high morbidity and mortality.Beta-blockers(BB)and calcium channel blockers(CCB)are commonly used for symptom control and comorbidity management,but their comparative effectiveness and safety remain unclear.AIM To compare the effectiveness and safety of BB vs CCB in patients with HFpEF using simulated real-world data and propensity score-matched analyses.METHODS Simulated data for 4000 HFpEF patients(2000 BB,2000 CCB)were generated based on distributions extracted from electronic medical records spanning 2014-2023.Inclusion criteria included adults with left ventricular ejection fraction≥50%and initiation of BB or CCB.Effectiveness outcomes encompassed mortality,heart failure hospitalizations,and changes in clinical parameters.Safety outcomes included bradycardia,hypotension,and drug discontinuation.Statistical analyses used t-tests,χ2 tests,Cox proportional hazards models for hazard ratios(HR),and incidence rate ratios(IRR)in R software.Propensity score matching(PSM)was performed to balance baseline characteristics,with outcomes reassessed in the matched cohort.RESULTS Baseline characteristics were largely balanced,with minor differences in sex,chronic kidney disease,systolic blood pressure,and left atrial volume index.BB demonstrated lower all-cause mortality(crude HR 0.78,95%CI:0.70-0.87,P=0.003),heart failure hospitalization(crude HR 0.86,95%CI:0.77-0.96,P=0.031),and composite endpoint(crude HR 0.85,95%CI:0.79-0.91,P<0.001)rates compared to CCB.IRR for heart failure hospitalizations and emergency visits favored BB.Safety profiles showed higher symptomatic bradycardia(9.2%vs 4.9%,P<0.001)and drug discontinuation(11.3%vs 9.3%,P=0.043)with BB,and higher hypotension(7.2%vs 11.5%,P<0.001)with CCB.Matched analyses showed all-cause mortality rates of 0.0622 per person-year for BB vs 0.0649 for CCB(HR 0.96,95%CI:0.85-1.08),heart failure hospitalization rates of 0.0751 vs 0.0888(HR 0.84,95%CI:0.75-0.94),and IRR for number of heart failure hospitalizations of 1.65 for CCB vs BB(95%CI:1.51-1.80,P<0.001).CONCLUSION BB may offer potential advantages in reducing mortality and hospitalizations in HFpEF compared to CCB,with distinct safety considerations.PSM confirmed these trends with reduced confounding.Personalized therapy is recommended,warranting prospective trials for validation.
文摘Major solar plasma disturbances are subjected to Lomb-Scargle periodogram and wavelet analysis to determine the occurrence frequency.These disruptions include interplanetary coronal mass ejection,sudden storm commencement,high-speed streams,corotating interaction regions,interplanetary shocks and Forbush decreases.We included information on all of the aforementioned solar disturbances for the last six solar cycles,from 1965 to 2023,for this study.Our findings reveal some intriguing and noteworthy results that clearly distinguish between even and odd-numbered solar cycles.The study suggests that the Sun behaves differently in odd and even-numbered solar cycles as it comes from the massive solar eruptions.During even-numbered solar cycles,variations with a period of∼44 days are prominently observed in addition to solar rotation(∼27 days)and extended solar(∼36 days)rotation.However,in addition to solar rotation,prolonged solar rotation,and periods of around 44 days,we also detect a number of intermittent changes with nearly comparable amplitude during the oddnumbered solar cycles.The findings also demonstrate that,in contrast to odd-numbered solar cycles,the emissions rate of these disruptions is more distinct and predictable during even-numbered solar cycles.
