The thermochemical non-equilibrium phenomena encountered by hypersonic vehicles present significant challenges in their design.To investigate the thermochemical reaction flow behind shock waves,the non-equilibrium rad...The thermochemical non-equilibrium phenomena encountered by hypersonic vehicles present significant challenges in their design.To investigate the thermochemical reaction flow behind shock waves,the non-equilibrium radiation in the visible range using a shock tube was studied.Experiments were conducted with a shock velocity of 4.7 km/s,using nitrogen at a pressure of 20 Pa.To address measurement difficulties associated with weak radiation,a special square section shock tube with a side length of 380 mm was utilized.A high-speed camera characterized the shock wave’s morphology,and a spectrograph and a monochromator captured the radiation.The spectra were analyzed,and the numerical spectra were compared with experimental results,showing a close match.Temperature changes behind the shock wave were obtained and compared with numerical predictions.The findings indicate that the vibrational temperatures are overestimated,while the vibrational relaxation time is likely underestimated,due to the oversimplified portrayals of the non-equilibrium relaxation process in the models.Additionally,both experimental and simulated time-resolved profiles of radiation intensity at specific wavelengths were analyzed.The gathered data aims to enhance computational fluid dynamics codes and radiation models,improving their predictive accuracy.展开更多
Traffic engineering such as tunnels in various altitudinal gradient zone are at risk of accidental explosion,which can damage personnel and equipment.Accurate prediction of the distribution pattern of explosive loads ...Traffic engineering such as tunnels in various altitudinal gradient zone are at risk of accidental explosion,which can damage personnel and equipment.Accurate prediction of the distribution pattern of explosive loads and shock wave propagation process in semi-enclosed structures at various altitude environment is key research focus in the fields of explosion shock and fluid dynamics.The effect of altitude on the propagation of shock waves in tunnels was investigated by conducting explosion test and numerical simulation.Based on the experimental and numerical simulation results,a prediction model for the attenuation of the peak overpressure of tunnel shock waves at different altitudes was established.The results showed that the peak overpressure decreased at the same measurement points in the tunnel entrance under the high altitude condition.In contrast,an increase in altitude accelerated the propagation speed of the shock wave in the tunnel.The average error between the peak shock wave overpressure obtained using the overpressure prediction formula and the measured test data was less than15%,the average error between the propagation velocity of shock waves predicted values and the test data is less than 10%.The method can effectively predict the overpressure attenuation of blast wave in tunnel at various altitudes.展开更多
We are intrigued by the issues of shock instability,with a particular emphasis on numerical schemes that address the carbuncle phenomenon by reducing dissipation rather than increasing it.For a specific class of plana...We are intrigued by the issues of shock instability,with a particular emphasis on numerical schemes that address the carbuncle phenomenon by reducing dissipation rather than increasing it.For a specific class of planar flow fields where the transverse direction exhibits vanishing but non-zero velocity components,such as a disturbed onedimensional(1D)steady shock wave,we conduct a formal asymptotic analysis for the Euler system and associated numerical methods.This analysis aims to illustrate the discrepancies among various low-dissipative numerical algorithms.Furthermore,a numerical stability analysis of steady shock is undertaken to identify the key factors underlying shock-stable algorithms.To verify the stability mechanism,a consistent,low-dissipation,and shock-stable HLLC-type Riemann solver is presented.展开更多
Titanium(Ti)and its alloys are frequently utilized as critical components in a variety of engineering ap-plications because of their high specific strength and excellent corrosion resistance.Compared to conven-tional ...Titanium(Ti)and its alloys are frequently utilized as critical components in a variety of engineering ap-plications because of their high specific strength and excellent corrosion resistance.Compared to conven-tional surface strengthening technologies,laser shock peening(LSP)has increasingly attracted attention from researchers and industries,since it significantly improves the surface strength,biocompatibility,fa-tigue resistance,and anti-corrosion ability of Ti and its alloys.Despite numerous studies that have been carried out to elucidate the effects of LSP on microstructural evolution and mechanical properties of Ti and its alloys in recent years,a comprehensive review of recent advancements in the field of Ti and its alloys subjected to LSP is still lacking.In this review,the standard LSP and the novel process designs of LSP assisted by thermal,cryogenic,electropulsing and magnetic fields are discussed and compared.Microstructural evolution,with focuses on the dislocation dynamics,deformation twinning,grain refine-ment and surface amorphization,during LSP processing of Ti alloys is reviewed.Furthermore,the en-hanced engineering performance of the L SP-processed(L SPed)Ti alloys,including surface hardness,wear resistance,fatigue life and corrosion resistance are summarized.Finally,this review concludes by present-ing an overview of the current challenges encountered in this field and offering insights into anticipated future trends.展开更多
BACKGROUND Various stone factors can affect the net results of shock wave lithotripsy(SWL).Recently a new factor called variation coefficient of stone density(VCSD)is being considered to have an impact on stone free r...BACKGROUND Various stone factors can affect the net results of shock wave lithotripsy(SWL).Recently a new factor called variation coefficient of stone density(VCSD)is being considered to have an impact on stone free rates.AIM To assess the role of VCSD in determining success of SWL in urinary calculi.METHODS Charts review was utilized for collection of data variables.The patients were subjected to SWL,using an electromagnetic lithotripter.Mean stone density(MSD),stone heterogeneity index(SHI),and VCSD were calculated by generating regions of interest on computed tomography(CT)images.Role of these factors were determined by applying the relevant statistical tests for continuous and categorical variables and a P value of<0.05 was gauged to be statistically significant.RESULTS There were a total of 407 patients included in the analysis.The mean age of the subjects in this study was 38.89±14.61 years.In total,165 out of the 407 patients could not achieve stone free status.The successful group had a significantly lower stone volume as compared to the unsuccessful group(P<0.0001).Skin to stone distance was not dissimilar among the two groups(P=0.47).MSD was significantly lower in the successful group(P<0.0001).SHI and VCSD were both significantly higher in the successful group(P<0.0001).CONCLUSION VCSD,a useful CT based parameter,can be utilized to gauge stone fragility and hence the prediction of SWL outcomes.展开更多
BACKGROUND Hypernatremia represents a significant electrolyte imbalance associated with numerous adverse outcomes,particularly in cases of intensive care unit(ICU)-acquired hypernatremia(IAH).Nevertheless,its relevanc...BACKGROUND Hypernatremia represents a significant electrolyte imbalance associated with numerous adverse outcomes,particularly in cases of intensive care unit(ICU)-acquired hypernatremia(IAH).Nevertheless,its relevance in patients with septic shock remains uncertain.AIM To identify independent risk factors and their predictive efficacy for IAH to improve outcomes in patients with septic shock.METHODS In the present retrospective single-center study,a cohort of 157 septic shock patients with concurrent hypernatremia in the ICU at The First Affiliated Hospital of Soochow University,between August 1,2018,and May 31,2023,were analyzed.Patients were categorized based on the timing of hypernatremia occurrence into the IAH group(n=62),the non-IAH group(n=41),and the normonatremia group(n=54).RESULTS In the present study,there was a significant association between the high serum sodium concentrations,excessive persistent inflammation,immunosuppression and catabolism syndrome and chronic critical illness,while rapid recovery had an apparent association with normonatremia.Moreover,multivariable analyses revealed the following independent risk factors for IAH:Total urinary output over the preceding three days[odds ratio(OR)=1.09;95%CI:1.02–1.17;P=0.014],enteral nutrition(EN)sodium content of 500 mg(OR=2.93;95%CI:1.13–7.60;P=0.027),and EN sodium content of 670 mg(OR=6.19;95%CI:1.75–21.98;P=0.005)were positively correlated with the development of IAH.Notably,the area under the curve for total urinary output over the preceding three days was 0.800(95%CI:0.678–0.922,P=0.001).Furthermore,maximum serum sodium levels,the duration of hypernatremia,and varying sodium correction rates were significantly associated with 28-day in-hospital mortality in septic shock patients(P<0.05).CONCLUSION The present findings illustrate that elevated serum sodium level was significantly associated with a poor prognosis in septic shock patients in the ICU.It is highly recommended that hypernatremia be considered a potentially important prognostic indicator for the outcome of septic shock.展开更多
Electrocatalytic reduction of carbon dioxide(CO_(2))to carbon monoxide(CO)is an effective strategy to achieve carbon neutrality.High selective and low-cost catalysts for the electrocatalytic reduction of CO_(2)have re...Electrocatalytic reduction of carbon dioxide(CO_(2))to carbon monoxide(CO)is an effective strategy to achieve carbon neutrality.High selective and low-cost catalysts for the electrocatalytic reduction of CO_(2)have received increasing attention.In contrast to the conventional tube furnace method,the high-temperature shock(HTS)method enables ultra-fast thermal processing,superior atomic efficiency,and a streamlined synthesis protocol,offering a simplified method for the preparation of high-performance single-atom catalysts(SACs).The reports have shown that nickel-based SACs can be synthesized quickly and conveniently using the HTS method,making their application in CO_(2)reduction reactions(CO_(2)RR)a viable and promising avenue for further exploration.In this study,the effect of heating temperature,metal loading and different nitrogen(N)sources on the catalyst morphology,coordination environment and electrocatalytic performance were investigated.Under optimal conditions,0.05Ni-DCD-C-1050 showed excellent performance in reducing CO_(2)to CO,with CO selectivity close to 100%(−0.7 to−1.0 V vs RHE)and current density as high as 130 mA/cm^(2)(−1.1 V vs RHE)in a flow cell under alkaline environment.展开更多
BACKGROUND Cytomegalovirus(CMV)infections can cause significant morbidity and mortality in immunocompromised individuals.CMV targets dysfunctional lymphocytes.Chronic rituximab(RTX)therapy can cause B-lymphocyte dysfu...BACKGROUND Cytomegalovirus(CMV)infections can cause significant morbidity and mortality in immunocompromised individuals.CMV targets dysfunctional lymphocytes.Chronic rituximab(RTX)therapy can cause B-lymphocyte dysfunction,increasing CMV risk.Rarely,CMV infections present with critical illness such as septic shock.CASE SUMMARY A 64-year-old African American woman presented with generalized weakness and non-bloody watery diarrhea of 4-6 weeks duration.She did not have nausea,vomiting or,abdominal pain.She had been on monthly RTX infusions for neuromyelitis optica.She was admitted for septic shock due to pancolitis.Blood investigations suggested pancytopenia and serology detected significantly elevated CMV DNA.Valganciclovir treatment led to disease resolution.CONCLUSION This case illustrates an extremely rare case of CMV colitis associated with RTX use presenting with septic shock.High suspicion for rare opportunistic infections is imperative in individuals with long-term RTX use.展开更多
The concept of local shock strength and a quantitative measure index str of local shock strength are proposed,derived from the oblique shock relation and the monotonic relationship between total pressure loss ratio an...The concept of local shock strength and a quantitative measure index str of local shock strength are proposed,derived from the oblique shock relation and the monotonic relationship between total pressure loss ratio and normal Mach number.Utilizing the high density gradient characteristic of shock waves and the oblique shock relation,a post-processing algorithm for two-dimensional flow field data is developed.The objective of the post-processing algorithm is to obtain specific shock wave location coordinates and calculate the corresponding str from flow filed data under the calibration of the oblique shock relation.Valida-tion of this post-processing algorithm is conducted using a standard model example that can be solved analytically.Combining the concept of local shock strength with the post-processing algorithm,a local shock strength quantitative mapping approach is established for the first time.This approach enables a quantitative measure and visualization of local shock strength at distinct locations,represented by color mapping on the shock structures.The approach can be applied to post-processing numerical sim-ulation data of two-dimensional flows.Applications to the intersection of two left-running oblique shock waves(straight shock waves),the bow shock in front of a cylinder(curved shock wave),and Mach reflection(mixed straight and curved shock waves)demonstrate the accuracy,and effectiveness of the mapping approach in investigating diverse shock wave phenomena.The quan-titative mapping approach of str may be a valuable tool in the design of supersonic/hypersonic vehicles and the exploration of shock wave evolution.展开更多
A novel porous shock absorption layer is put forward in this study, and the shock absorption performance of the porous shock absorption layer is evaluated based on three-dimensional pseudo-static analysis. The modifie...A novel porous shock absorption layer is put forward in this study, and the shock absorption performance of the porous shock absorption layer is evaluated based on three-dimensional pseudo-static analysis. The modified reaction acceleration method is adopted and validated in the three-dimensional model. Seven ground motions are selected and the peak ground acceleration is adjusted to 0.2 g, 0.4 g and 0.6 g. The impact of the void ratio and thickness of the porous shock absorption layer is studied, while the surrounding rock grade and tunnel depth are also investigated. The numerical results show that the porous shock absorption layer has good shock absorption performance and can effectively reduce the maximum internal force of the secondary lining, but it cannot reduce the maximum horizontal relative displacement of the secondary lining. The circumferential rubber strip in the porous shock absorption layer will reduce shock absorption performance. The results of parameter analysis indicate that the shock absorption performance of the porous shock absorption layer increases with the increase of the void ratio and thickness, and it has good shock absorption performance under different surrounding rock grades and tunnel depths.展开更多
An experiment was conducted to assess the impact of fused calcia-stabilized zirconia micro-powder on the thermal shock behavior of magnesia–spinel refractories.The effects of calcia-stabilized zirconia on the microst...An experiment was conducted to assess the impact of fused calcia-stabilized zirconia micro-powder on the thermal shock behavior of magnesia–spinel refractories.The effects of calcia-stabilized zirconia on the microstructure evolution and properties of magnesia–spinel refractories were characterized by the high-temperature elastic modulus,thermal shock damage resistance parameters,retainment of elastic modulus after thermal shock,and scanning electron microscopy.The results indicated that the incorporation of calcia-stabilized zirconia improved the thermomechanical properties and thermal shock behavior of magnesia–spinel specimens.The hot modulus of rupture of magnesia–spinel specimens increased by 2.5-fold due to the incorporation of calcia-stabilized zirconia micro-powder.The presence of a martensitic phase transformation in partially unstable ZrO2 and thermal mismatches among various phases contributed to a controlled formation of microcracks.And the pinning effect caused by the calcia-stabilized zirconia particles surrounding the grain boundaries played a crucial role in preventing the propagation of microcracks.This phenomenon significantly bolstered the thermal shock stability of magnesia–spinel refractories,consequently prolonging their service life.展开更多
Small heat shock proteins(sHSPs)act as molecular chaperones that can prevent the accumulation of damaged proteins during abiotic stress,especially heat shock,but the mechanism is not clear.To study the function of sHS...Small heat shock proteins(sHSPs)act as molecular chaperones that can prevent the accumulation of damaged proteins during abiotic stress,especially heat shock,but the mechanism is not clear.To study the function of sHSPs in Lenzites gibbosa,a common polypore in northern temperate forests that causes spongy white rot of broadleaf trees,under temperature stress,L.gibbosa mycelia were grown at 25℃ for 9 d,treated at 33℃ for 15,30,60,and 120 min before sequencing the transcriptomes.From among 32 heat shock protein(HSP)genes found in the screen of the transcriptome data,a highly expressed gene was cloned and named Lghsp17.4.RT-qPCR was used to analyze the expression of the gene Lghsp17.4 under heat shock and dye stress.Both treatments induced higher expression of Lghsp17.4 at the transcriptional level,indicating that Lghsp17.4 might function in the response to heat stress and dye degradation.We previously found that L.gibbosa generally had a heat shock reaction(HSR)during degradation of aromatic compounds,and HSPs were always produced with manganese peroxidases(MnPs)and other lignin-degrading enzymes.Therefore,we measured the activity of MnPs in L.gibbosa after 33℃ heat shock to analyze the relationship between MnPs expression and Lghsp17.4 expression.Heat shocks of 0–30 min increased MnPs activity,and the change in MnPs activity were closely positively correlated with the expression levels of Lghsp17.4 over time,indicating a potential connection and interaction between LgHSP17.4 and MnPs during the HSR in L.gibbosa.Thus,LgHSP17.4 might have a positive regulatory effect on the HSR in L.gibbosa and be a critical component of a stress resistance mechanism.展开更多
BACKGROUND:Resuscitative endovascular balloon occlusion of the aorta(REBOA)is a minimally invasive technique used to control non-compressible torso hemorrhage.However,the optimal degree of partial occlusion that off e...BACKGROUND:Resuscitative endovascular balloon occlusion of the aorta(REBOA)is a minimally invasive technique used to control non-compressible torso hemorrhage.However,the optimal degree of partial occlusion that off ers maximum therapeutic benefi t remains unclear.This study aimed to identify the optimal partial infl ation volume for REBOA.METHODS:In a swine model of hemorrhagic shock,nine healthy female pigs were randomly assigned to three groups based on balloon inflation volume:30%(R30),60%(R60),and 100%(R100)of the volume required to eliminate the contralateral femoral arterial waveform.Hemodynamic variables,fluid and vasopressor requirements,and biochemical markers were evaluated during balloon occlusion and resuscitation following 40%blood volume-controlled hemorrhage.RESULTS:The R30 group showed higher mean arterial pressure during resuscitation and required less fluid and norepinephrine than those of the R100 group.The mean heart rate significantly differed over time among the groups,with more gradual changes in the R30 group.Markers of ischemia-reperfusion injury(lactate,pH,blood urea nitrogen,and creatinine)similarly exhibited significant temporal differences.Post hoc analysis revealed significant pH differences between the groups.The plasma lactate and creatinine levels were significantly lower in the R30 group than those in the other two groups.CONCLUSION:In this swine hemorrhagic shock model,partial REBOA with 30%balloon inflation maintained hemodynamic stability while reducing metabolic derangement compared with higher ballon volumes of 60%and 100%inflation.A strategy involving partial inflation targeting approximately 30%,followed by monitoring the blood pressure trend while using a vasoconstrictor,if necessary,may have potential clinical utility.展开更多
Aortic stenosis(AS)is one of the most common types of valvular heart disease in older adults,with age being significantly associated with the development of AS.The transcatheter aortic valve replacement(TAVR)procedure...Aortic stenosis(AS)is one of the most common types of valvular heart disease in older adults,with age being significantly associated with the development of AS.The transcatheter aortic valve replacement(TAVR)procedure,since it was first performed in 2002,has emerged as a preferred treatment option for patients who are at intermediate to high surgical risk due to advanced age or medical comorbidities.Older adults with severe AS may present with acute decompensated heart failure leading to cardiogenic shock(CS).Among patients 65 years and older with AS presenting for TAVR,4.1%were reportedly in acute CS.Regardless of etiology,mortality from CS itself is high(30%−50%)and increases with advancing age.TAVR for these patients could provide a definite treatment for both AS and CS.There is still limited evidence regarding the safety and efficacy of TAVR in this population,but recent studies are promising,with successful procedural results and a good recovery rate after the procedure.However,particularly for older adults,there are other factors that clinicians should consider during pre-and post-procedural status,such as patient’s goals,frailty,polypharmacy,dementia,or delirium.In this article,we reviewed current studies regarding TAVR for older adults with AS and CS,the reason for comprehensive geriatric assessment,and the introduction of appropriate geriatric assessment tools based on the Age-Friendly 4Ms framework that cardiologists can adopt in real-world practice.展开更多
BACKGROUND Septic shock,the most severe form of sepsis,remains a major global health challenge with high mortality.The coronavirus disease 2019(COVID-19)pandemic has exacerbated this burden,as severe acute respiratory...BACKGROUND Septic shock,the most severe form of sepsis,remains a major global health challenge with high mortality.The coronavirus disease 2019(COVID-19)pandemic has exacerbated this burden,as severe acute respiratory syndrome coronavirus 2 infection often leads to sepsis and septic shock.Racial and ethnic differences in critical illness outcomes are well-documented,but their impact on COVID-19 associated septic shock remains unclear.AIM To examine epidemiologic data to explore racial and ethnic differences in outcomes in COVID-19 associated septic shock.METHODS Using the National Inpatient Sample(2020–2021),we conducted a retrospective cohort study to assess racial and ethnic disparities in septic shock outcomes among adults(≥18 years)with concurrent COVID-19.Primary and secondary outcomes included in-hospital mortality,acute kidney injury(AKI),AKI requiring dialysis,and mechanical ventilation.Adjusted multivariable logistic regression accounted for demographics,comorbidities,hospital characteristics,and inhospital events.RESULTS Among 396795 weighted hospitalizations,Non-Hispanic Black(NHB)(25.3%)and Hispanic(30.4%)populations were younger and had greater comorbidity burdens than Non-Hispanic White(NHW)patients.Compared to NHW,adjusted analyses showed higher in-hospital mortality[adjusted odds ratio(aOR)=1.21,95%CI:1.15-1.27],mechanical ventilation use(aOR=1.19,95%CI:1.12-1.27)and AKI requiring dialysis(aOR=1.16,95%CI:1.07-1.25,P<0.001)among Hispanic patients.NHB patients had similar mortality to NHWs but had higher risk of mechanical ventilation(aOR=1.15,95%CI:1.09-1.22)and AKI requiring dialysis(aOR=1.65,95%CI:1.54-1.76).Mean length of stay and cost were longest and highest for Hispanic patients.CONCLUSION Our study showed that there was higher mortality in Hispanic patients,and higher renal and respiratory complication in both NHB and Hispanic groups compared to NHW group.Future research identifying the causes of the observed differences in complications are required to inform targeted strategies that may mitigate modifiable risk factors and optimize early detection of organ failure to optimize outcomes in this population.展开更多
BACKGROUND Bradycardia,renal failure,atrioventricular nodal blockade,shock,and hyper-kalemia(BRASH)syndrome is an acronym used to describe a constellation of BRASH.It is an underrecognized phenomenon that can be deadl...BACKGROUND Bradycardia,renal failure,atrioventricular nodal blockade,shock,and hyper-kalemia(BRASH)syndrome is an acronym used to describe a constellation of BRASH.It is an underrecognized phenomenon that can be deadly if not appro-priately managed in a timely manner.This case highlights the importance of rapid diagnosis and reviews a multitude of treatment options in a uniquely severe case of BRASH syndrome.CASE SUMMARY We present a case of a 54-year-old male on a beta-blocker and angiotensin-con-verting enzyme inhibitor who presented with one day history of nausea,vomi-ting,and shortness of breath.Upon presentation,he was bradycardic and hypotensive,requiring transcutaneous pacing.Initial electrocardiogram showed atrial fibrillation with ventricular rate in 30’s.He was found to have acute kidney injury,hyperkalemia,and metabolic acidosis.He was successfully treated with multiple potassium lowering agents,continuous renal replacement therapy,four pressors,mechanical ventilation,and transvenous pacing with complete recovery prior to discharge.CONCLUSION Increased awareness of BRASH syndrome may improve outcomes through timely diagnosis and aggressive intervention.展开更多
This research employs micro-CT scanning technology to analyze the porosity,pore fractal dimension,and spatial variability of sandstone preheated to 600℃ and subsequently cooled in water at varying temperatures(20℃,6...This research employs micro-CT scanning technology to analyze the porosity,pore fractal dimension,and spatial variability of sandstone preheated to 600℃ and subsequently cooled in water at varying temperatures(20℃,60℃,100℃).The study investigates the mechanisms by which various factors influence thermal shock damage,focusing on the effects of cooling water temperature and the boiling phase transition.The objective is to develop a method for characterizing thermal shock damage that considers spatial variability.The findings indicate that thermal shock damage is limited to a shallow depth beneath the surface,with increased severity near the surface.The boiling phase transition significantly enhances the convective heat transfer coefficient,resulting in substantially higher thermal shock damage when cooled with 100℃ boiling water compared to 20℃ and 60℃ water.Furthermore,for the entire specimen,heating damage exceeds thermal shock damage,and the influence of thermal shock diminishes as specimen size increases.This study addresses the limitations of traditional methods for assessing thermal shock damage that disregard spatial variability and provides practical guidance for engineering projects to manage thermal shock damage more effectively.展开更多
BACKGROUND Septic shock represents one of the most severe critical illness types,characterized by significant hemodynamic disorders and neuropsychiatric symptoms.This study aimed to investigate the association mechani...BACKGROUND Septic shock represents one of the most severe critical illness types,characterized by significant hemodynamic disorders and neuropsychiatric symptoms.This study aimed to investigate the association mechanism between hemodynamic indicators and neuropsychiatric symptoms in patients with septic shock,revealing potential pathophysiological connections.AIM To investigate the link between hemodynamic parameters and neuropsychiatric symptoms in septic shock.METHODS A retrospective case-control study involving 132 patients with septic shock.Multiple assessment tools were employed,including the Confusion Assessment Method,Hospital Anxiety and Depression Scale,Posttraumatic Stress Disorder Scale,and Mini-Mental State Examination,systematically evaluating patients’neuropsychiatric symptoms and hemodynamic indicators.RESULTS Patient mean age was 52.4±12.3 years,with 68.5%males.Multivariate analysis revealed significant correlations between neuropsychiatric symptom severity and mean arterial pressure<65 mmHg[odds ratio(OR)=2.7],lactate levels>4 mmol/L(OR=3.1),and elevated interleukin-6 inflammatory factors(OR=2.4).Neuropsychiatric symptom incidence rates were:Delirium 37.1%;anxiety 28.8%;depression 24.2%;and posttraumatic stress disorder 19.7%.CONCLUSION Hemodynamic disorders in patients with septic shock are closely associated with neuropsychiatric symptoms,influencing central nervous system function through complex inflammatory and neurotransmitter pathways.展开更多
We present and explore a new shock-capturing particle hydrodynamics approach.Our starting point is a commonly used discretization of smoothed particle hydrodynamics.We enhance this discretization with Roe’s approx-im...We present and explore a new shock-capturing particle hydrodynamics approach.Our starting point is a commonly used discretization of smoothed particle hydrodynamics.We enhance this discretization with Roe’s approx-imate Riemann solver,we identify its dissipative terms,and in these terms,we use slope-limited linear reconstruction.All gradients needed for our method are calculated with linearly reproducing kernels that are constructed to enforce the two lowest-order consistency relations.We scrutinize our reproducing kernel implementation carefully on a“glass-like”particle distribution,and we find that constant and linear functions are recovered to machine precision.We probe our method in a series of challenging 3D benchmark problems ranging from shocks over instabilities to Schulz-Rinne-type vorticity-creating shocks.All of our simulations show excellent agreement with analytic/reference solutions.展开更多
BACKGROUND Sepsis and septic shock pose critical public health challenges with high mortality,particularly in critical care.While racial differences in sepsis incidence are documented,the impact of race on sepsis outc...BACKGROUND Sepsis and septic shock pose critical public health challenges with high mortality,particularly in critical care.While racial differences in sepsis incidence are documented,the impact of race on sepsis outcomes remains inconsistent.AIM To evaluate racial disparities in clinical outcomes among patients hospitalized with septic shock,focusing on in-hospital mortality,length of stay(LOS),and hospitalization costs.METHODS We conducted a retrospective cohort study using the National Inpatient Sample database from 2016 to 2021.Patients diagnosed with septic shock were identified using ICD-10 code R65.21.The primary outcome was in-hospital mortality;secondary outcomes included trends in septic shock hospitalizations,mortality,length of stay,and cost of hospitalizations.RESULTS Among 3581504 hospitalizations for septic shock,the racial distribution was 67%Non-Hispanic White(NHW),15%Non-Hispanic Black(NHB),11%Hispanic,and 7%other groups,with a mean age of 66.3 years.In-hospital mortality was 33.6%,highest among other racial groups(36.7%).Mortality was stable across racial groups from 2016-2019 but rose sharply in 2020-2021,especially among Hispanic patients.Adjusted in-hospital mortality were higher for NHB and Hispanic compared to NHW patients.NHB patients had the longest LOS,while other racial groups incurred the highest cost of hospitalizations.CONCLUSION We found higher mortality among NHB,Hispanic,and other racial groups in septic shock patients,likely driven by higher risk of in-hospital complications among these racial groups.This highlights the need for future research to identify the factors contributing to the adverse outcomes in these populations.展开更多
基金supported by the Key-Area Research and Development Program of Guangdong Province(Grant No.2021B0909060004)the National Natural Science Foundation of China(Grant Nos.12072355 and 92271117)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB0620202).
文摘The thermochemical non-equilibrium phenomena encountered by hypersonic vehicles present significant challenges in their design.To investigate the thermochemical reaction flow behind shock waves,the non-equilibrium radiation in the visible range using a shock tube was studied.Experiments were conducted with a shock velocity of 4.7 km/s,using nitrogen at a pressure of 20 Pa.To address measurement difficulties associated with weak radiation,a special square section shock tube with a side length of 380 mm was utilized.A high-speed camera characterized the shock wave’s morphology,and a spectrograph and a monochromator captured the radiation.The spectra were analyzed,and the numerical spectra were compared with experimental results,showing a close match.Temperature changes behind the shock wave were obtained and compared with numerical predictions.The findings indicate that the vibrational temperatures are overestimated,while the vibrational relaxation time is likely underestimated,due to the oversimplified portrayals of the non-equilibrium relaxation process in the models.Additionally,both experimental and simulated time-resolved profiles of radiation intensity at specific wavelengths were analyzed.The gathered data aims to enhance computational fluid dynamics codes and radiation models,improving their predictive accuracy.
基金financially supported by National Natural Science Foundation of China(Grant Nos.52378401,52278504)the Fundamental Research Funds for the Central Universities(Grant No.30922010918)。
文摘Traffic engineering such as tunnels in various altitudinal gradient zone are at risk of accidental explosion,which can damage personnel and equipment.Accurate prediction of the distribution pattern of explosive loads and shock wave propagation process in semi-enclosed structures at various altitude environment is key research focus in the fields of explosion shock and fluid dynamics.The effect of altitude on the propagation of shock waves in tunnels was investigated by conducting explosion test and numerical simulation.Based on the experimental and numerical simulation results,a prediction model for the attenuation of the peak overpressure of tunnel shock waves at different altitudes was established.The results showed that the peak overpressure decreased at the same measurement points in the tunnel entrance under the high altitude condition.In contrast,an increase in altitude accelerated the propagation speed of the shock wave in the tunnel.The average error between the peak shock wave overpressure obtained using the overpressure prediction formula and the measured test data was less than15%,the average error between the propagation velocity of shock waves predicted values and the test data is less than 10%.The method can effectively predict the overpressure attenuation of blast wave in tunnel at various altitudes.
基金Project supported by the National Natural Science Foundation of China(Nos.12471367 and12361076)the Research Program of Science and Technology at Universities of Inner Mongolia Autonomous Region(Nos.NJZY19186,NJZY22036,and NJZY23003)。
文摘We are intrigued by the issues of shock instability,with a particular emphasis on numerical schemes that address the carbuncle phenomenon by reducing dissipation rather than increasing it.For a specific class of planar flow fields where the transverse direction exhibits vanishing but non-zero velocity components,such as a disturbed onedimensional(1D)steady shock wave,we conduct a formal asymptotic analysis for the Euler system and associated numerical methods.This analysis aims to illustrate the discrepancies among various low-dissipative numerical algorithms.Furthermore,a numerical stability analysis of steady shock is undertaken to identify the key factors underlying shock-stable algorithms.To verify the stability mechanism,a consistent,low-dissipation,and shock-stable HLLC-type Riemann solver is presented.
基金supported by the National Key R&D Plan of China(No.2022YFB3705603)the National Natural Science Foundation of China(No.52101046)+1 种基金the Excellent Youth Overseas Project of National Science and Natural Foundation of China,the Baowu Special Metallurgy Cooperation Limited(No.22H010101336)the Medicine-Engineering Interdisciplinary Project of Shanghai Jiao Tong University(No.YG2022QN076).
文摘Titanium(Ti)and its alloys are frequently utilized as critical components in a variety of engineering ap-plications because of their high specific strength and excellent corrosion resistance.Compared to conven-tional surface strengthening technologies,laser shock peening(LSP)has increasingly attracted attention from researchers and industries,since it significantly improves the surface strength,biocompatibility,fa-tigue resistance,and anti-corrosion ability of Ti and its alloys.Despite numerous studies that have been carried out to elucidate the effects of LSP on microstructural evolution and mechanical properties of Ti and its alloys in recent years,a comprehensive review of recent advancements in the field of Ti and its alloys subjected to LSP is still lacking.In this review,the standard LSP and the novel process designs of LSP assisted by thermal,cryogenic,electropulsing and magnetic fields are discussed and compared.Microstructural evolution,with focuses on the dislocation dynamics,deformation twinning,grain refine-ment and surface amorphization,during LSP processing of Ti alloys is reviewed.Furthermore,the en-hanced engineering performance of the L SP-processed(L SPed)Ti alloys,including surface hardness,wear resistance,fatigue life and corrosion resistance are summarized.Finally,this review concludes by present-ing an overview of the current challenges encountered in this field and offering insights into anticipated future trends.
文摘BACKGROUND Various stone factors can affect the net results of shock wave lithotripsy(SWL).Recently a new factor called variation coefficient of stone density(VCSD)is being considered to have an impact on stone free rates.AIM To assess the role of VCSD in determining success of SWL in urinary calculi.METHODS Charts review was utilized for collection of data variables.The patients were subjected to SWL,using an electromagnetic lithotripter.Mean stone density(MSD),stone heterogeneity index(SHI),and VCSD were calculated by generating regions of interest on computed tomography(CT)images.Role of these factors were determined by applying the relevant statistical tests for continuous and categorical variables and a P value of<0.05 was gauged to be statistically significant.RESULTS There were a total of 407 patients included in the analysis.The mean age of the subjects in this study was 38.89±14.61 years.In total,165 out of the 407 patients could not achieve stone free status.The successful group had a significantly lower stone volume as compared to the unsuccessful group(P<0.0001).Skin to stone distance was not dissimilar among the two groups(P=0.47).MSD was significantly lower in the successful group(P<0.0001).SHI and VCSD were both significantly higher in the successful group(P<0.0001).CONCLUSION VCSD,a useful CT based parameter,can be utilized to gauge stone fragility and hence the prediction of SWL outcomes.
基金Supported by The National Natural Science Foundation of China,No.82072130Key Medical Research Projects in Jiangsu Province,No.ZD2022021Suzhou Clinical Medical Center for Anesthesiology,No.Szlcyxzxj202102。
文摘BACKGROUND Hypernatremia represents a significant electrolyte imbalance associated with numerous adverse outcomes,particularly in cases of intensive care unit(ICU)-acquired hypernatremia(IAH).Nevertheless,its relevance in patients with septic shock remains uncertain.AIM To identify independent risk factors and their predictive efficacy for IAH to improve outcomes in patients with septic shock.METHODS In the present retrospective single-center study,a cohort of 157 septic shock patients with concurrent hypernatremia in the ICU at The First Affiliated Hospital of Soochow University,between August 1,2018,and May 31,2023,were analyzed.Patients were categorized based on the timing of hypernatremia occurrence into the IAH group(n=62),the non-IAH group(n=41),and the normonatremia group(n=54).RESULTS In the present study,there was a significant association between the high serum sodium concentrations,excessive persistent inflammation,immunosuppression and catabolism syndrome and chronic critical illness,while rapid recovery had an apparent association with normonatremia.Moreover,multivariable analyses revealed the following independent risk factors for IAH:Total urinary output over the preceding three days[odds ratio(OR)=1.09;95%CI:1.02–1.17;P=0.014],enteral nutrition(EN)sodium content of 500 mg(OR=2.93;95%CI:1.13–7.60;P=0.027),and EN sodium content of 670 mg(OR=6.19;95%CI:1.75–21.98;P=0.005)were positively correlated with the development of IAH.Notably,the area under the curve for total urinary output over the preceding three days was 0.800(95%CI:0.678–0.922,P=0.001).Furthermore,maximum serum sodium levels,the duration of hypernatremia,and varying sodium correction rates were significantly associated with 28-day in-hospital mortality in septic shock patients(P<0.05).CONCLUSION The present findings illustrate that elevated serum sodium level was significantly associated with a poor prognosis in septic shock patients in the ICU.It is highly recommended that hypernatremia be considered a potentially important prognostic indicator for the outcome of septic shock.
基金supported by the National Key R&D Program of China(2024YFB4106400)National Natural Science Foundation of China(22209200,52302331)。
文摘Electrocatalytic reduction of carbon dioxide(CO_(2))to carbon monoxide(CO)is an effective strategy to achieve carbon neutrality.High selective and low-cost catalysts for the electrocatalytic reduction of CO_(2)have received increasing attention.In contrast to the conventional tube furnace method,the high-temperature shock(HTS)method enables ultra-fast thermal processing,superior atomic efficiency,and a streamlined synthesis protocol,offering a simplified method for the preparation of high-performance single-atom catalysts(SACs).The reports have shown that nickel-based SACs can be synthesized quickly and conveniently using the HTS method,making their application in CO_(2)reduction reactions(CO_(2)RR)a viable and promising avenue for further exploration.In this study,the effect of heating temperature,metal loading and different nitrogen(N)sources on the catalyst morphology,coordination environment and electrocatalytic performance were investigated.Under optimal conditions,0.05Ni-DCD-C-1050 showed excellent performance in reducing CO_(2)to CO,with CO selectivity close to 100%(−0.7 to−1.0 V vs RHE)and current density as high as 130 mA/cm^(2)(−1.1 V vs RHE)in a flow cell under alkaline environment.
文摘BACKGROUND Cytomegalovirus(CMV)infections can cause significant morbidity and mortality in immunocompromised individuals.CMV targets dysfunctional lymphocytes.Chronic rituximab(RTX)therapy can cause B-lymphocyte dysfunction,increasing CMV risk.Rarely,CMV infections present with critical illness such as septic shock.CASE SUMMARY A 64-year-old African American woman presented with generalized weakness and non-bloody watery diarrhea of 4-6 weeks duration.She did not have nausea,vomiting or,abdominal pain.She had been on monthly RTX infusions for neuromyelitis optica.She was admitted for septic shock due to pancolitis.Blood investigations suggested pancytopenia and serology detected significantly elevated CMV DNA.Valganciclovir treatment led to disease resolution.CONCLUSION This case illustrates an extremely rare case of CMV colitis associated with RTX use presenting with septic shock.High suspicion for rare opportunistic infections is imperative in individuals with long-term RTX use.
基金supported by the National Natural Science Foundation of China(Grant No.12372233)the Fund of NPU-Duke China Seed Program(Grant No.119003067)the“111 Project”of China(Grant No.B17037-106).
文摘The concept of local shock strength and a quantitative measure index str of local shock strength are proposed,derived from the oblique shock relation and the monotonic relationship between total pressure loss ratio and normal Mach number.Utilizing the high density gradient characteristic of shock waves and the oblique shock relation,a post-processing algorithm for two-dimensional flow field data is developed.The objective of the post-processing algorithm is to obtain specific shock wave location coordinates and calculate the corresponding str from flow filed data under the calibration of the oblique shock relation.Valida-tion of this post-processing algorithm is conducted using a standard model example that can be solved analytically.Combining the concept of local shock strength with the post-processing algorithm,a local shock strength quantitative mapping approach is established for the first time.This approach enables a quantitative measure and visualization of local shock strength at distinct locations,represented by color mapping on the shock structures.The approach can be applied to post-processing numerical sim-ulation data of two-dimensional flows.Applications to the intersection of two left-running oblique shock waves(straight shock waves),the bow shock in front of a cylinder(curved shock wave),and Mach reflection(mixed straight and curved shock waves)demonstrate the accuracy,and effectiveness of the mapping approach in investigating diverse shock wave phenomena.The quan-titative mapping approach of str may be a valuable tool in the design of supersonic/hypersonic vehicles and the exploration of shock wave evolution.
基金Science and Technology Plan Project of Xizang Autonomous Region,China under Grant No.XZ202501YD0007。
文摘A novel porous shock absorption layer is put forward in this study, and the shock absorption performance of the porous shock absorption layer is evaluated based on three-dimensional pseudo-static analysis. The modified reaction acceleration method is adopted and validated in the three-dimensional model. Seven ground motions are selected and the peak ground acceleration is adjusted to 0.2 g, 0.4 g and 0.6 g. The impact of the void ratio and thickness of the porous shock absorption layer is studied, while the surrounding rock grade and tunnel depth are also investigated. The numerical results show that the porous shock absorption layer has good shock absorption performance and can effectively reduce the maximum internal force of the secondary lining, but it cannot reduce the maximum horizontal relative displacement of the secondary lining. The circumferential rubber strip in the porous shock absorption layer will reduce shock absorption performance. The results of parameter analysis indicate that the shock absorption performance of the porous shock absorption layer increases with the increase of the void ratio and thickness, and it has good shock absorption performance under different surrounding rock grades and tunnel depths.
基金supported by the Key Project of the National Natural Science Foundation of China(Grant No.U21A2058)the Hebei Guoliang New Materials Co.,Ltd.(Grant No.22150239J).
文摘An experiment was conducted to assess the impact of fused calcia-stabilized zirconia micro-powder on the thermal shock behavior of magnesia–spinel refractories.The effects of calcia-stabilized zirconia on the microstructure evolution and properties of magnesia–spinel refractories were characterized by the high-temperature elastic modulus,thermal shock damage resistance parameters,retainment of elastic modulus after thermal shock,and scanning electron microscopy.The results indicated that the incorporation of calcia-stabilized zirconia improved the thermomechanical properties and thermal shock behavior of magnesia–spinel specimens.The hot modulus of rupture of magnesia–spinel specimens increased by 2.5-fold due to the incorporation of calcia-stabilized zirconia micro-powder.The presence of a martensitic phase transformation in partially unstable ZrO2 and thermal mismatches among various phases contributed to a controlled formation of microcracks.And the pinning effect caused by the calcia-stabilized zirconia particles surrounding the grain boundaries played a crucial role in preventing the propagation of microcracks.This phenomenon significantly bolstered the thermal shock stability of magnesia–spinel refractories,consequently prolonging their service life.
基金supported by the Fundamental Research Funds for the Central Universities(Grant No.:2572016AA04)Northeast Asia Biodiversity Research Center Double First class Funds(Grant No.:411146030416 and No.:411147021003).
文摘Small heat shock proteins(sHSPs)act as molecular chaperones that can prevent the accumulation of damaged proteins during abiotic stress,especially heat shock,but the mechanism is not clear.To study the function of sHSPs in Lenzites gibbosa,a common polypore in northern temperate forests that causes spongy white rot of broadleaf trees,under temperature stress,L.gibbosa mycelia were grown at 25℃ for 9 d,treated at 33℃ for 15,30,60,and 120 min before sequencing the transcriptomes.From among 32 heat shock protein(HSP)genes found in the screen of the transcriptome data,a highly expressed gene was cloned and named Lghsp17.4.RT-qPCR was used to analyze the expression of the gene Lghsp17.4 under heat shock and dye stress.Both treatments induced higher expression of Lghsp17.4 at the transcriptional level,indicating that Lghsp17.4 might function in the response to heat stress and dye degradation.We previously found that L.gibbosa generally had a heat shock reaction(HSR)during degradation of aromatic compounds,and HSPs were always produced with manganese peroxidases(MnPs)and other lignin-degrading enzymes.Therefore,we measured the activity of MnPs in L.gibbosa after 33℃ heat shock to analyze the relationship between MnPs expression and Lghsp17.4 expression.Heat shocks of 0–30 min increased MnPs activity,and the change in MnPs activity were closely positively correlated with the expression levels of Lghsp17.4 over time,indicating a potential connection and interaction between LgHSP17.4 and MnPs during the HSR in L.gibbosa.Thus,LgHSP17.4 might have a positive regulatory effect on the HSR in L.gibbosa and be a critical component of a stress resistance mechanism.
基金supported by Seoul National University Hospital(0420210270).
文摘BACKGROUND:Resuscitative endovascular balloon occlusion of the aorta(REBOA)is a minimally invasive technique used to control non-compressible torso hemorrhage.However,the optimal degree of partial occlusion that off ers maximum therapeutic benefi t remains unclear.This study aimed to identify the optimal partial infl ation volume for REBOA.METHODS:In a swine model of hemorrhagic shock,nine healthy female pigs were randomly assigned to three groups based on balloon inflation volume:30%(R30),60%(R60),and 100%(R100)of the volume required to eliminate the contralateral femoral arterial waveform.Hemodynamic variables,fluid and vasopressor requirements,and biochemical markers were evaluated during balloon occlusion and resuscitation following 40%blood volume-controlled hemorrhage.RESULTS:The R30 group showed higher mean arterial pressure during resuscitation and required less fluid and norepinephrine than those of the R100 group.The mean heart rate significantly differed over time among the groups,with more gradual changes in the R30 group.Markers of ischemia-reperfusion injury(lactate,pH,blood urea nitrogen,and creatinine)similarly exhibited significant temporal differences.Post hoc analysis revealed significant pH differences between the groups.The plasma lactate and creatinine levels were significantly lower in the R30 group than those in the other two groups.CONCLUSION:In this swine hemorrhagic shock model,partial REBOA with 30%balloon inflation maintained hemodynamic stability while reducing metabolic derangement compared with higher ballon volumes of 60%and 100%inflation.A strategy involving partial inflation targeting approximately 30%,followed by monitoring the blood pressure trend while using a vasoconstrictor,if necessary,may have potential clinical utility.
文摘Aortic stenosis(AS)is one of the most common types of valvular heart disease in older adults,with age being significantly associated with the development of AS.The transcatheter aortic valve replacement(TAVR)procedure,since it was first performed in 2002,has emerged as a preferred treatment option for patients who are at intermediate to high surgical risk due to advanced age or medical comorbidities.Older adults with severe AS may present with acute decompensated heart failure leading to cardiogenic shock(CS).Among patients 65 years and older with AS presenting for TAVR,4.1%were reportedly in acute CS.Regardless of etiology,mortality from CS itself is high(30%−50%)and increases with advancing age.TAVR for these patients could provide a definite treatment for both AS and CS.There is still limited evidence regarding the safety and efficacy of TAVR in this population,but recent studies are promising,with successful procedural results and a good recovery rate after the procedure.However,particularly for older adults,there are other factors that clinicians should consider during pre-and post-procedural status,such as patient’s goals,frailty,polypharmacy,dementia,or delirium.In this article,we reviewed current studies regarding TAVR for older adults with AS and CS,the reason for comprehensive geriatric assessment,and the introduction of appropriate geriatric assessment tools based on the Age-Friendly 4Ms framework that cardiologists can adopt in real-world practice.
文摘BACKGROUND Septic shock,the most severe form of sepsis,remains a major global health challenge with high mortality.The coronavirus disease 2019(COVID-19)pandemic has exacerbated this burden,as severe acute respiratory syndrome coronavirus 2 infection often leads to sepsis and septic shock.Racial and ethnic differences in critical illness outcomes are well-documented,but their impact on COVID-19 associated septic shock remains unclear.AIM To examine epidemiologic data to explore racial and ethnic differences in outcomes in COVID-19 associated septic shock.METHODS Using the National Inpatient Sample(2020–2021),we conducted a retrospective cohort study to assess racial and ethnic disparities in septic shock outcomes among adults(≥18 years)with concurrent COVID-19.Primary and secondary outcomes included in-hospital mortality,acute kidney injury(AKI),AKI requiring dialysis,and mechanical ventilation.Adjusted multivariable logistic regression accounted for demographics,comorbidities,hospital characteristics,and inhospital events.RESULTS Among 396795 weighted hospitalizations,Non-Hispanic Black(NHB)(25.3%)and Hispanic(30.4%)populations were younger and had greater comorbidity burdens than Non-Hispanic White(NHW)patients.Compared to NHW,adjusted analyses showed higher in-hospital mortality[adjusted odds ratio(aOR)=1.21,95%CI:1.15-1.27],mechanical ventilation use(aOR=1.19,95%CI:1.12-1.27)and AKI requiring dialysis(aOR=1.16,95%CI:1.07-1.25,P<0.001)among Hispanic patients.NHB patients had similar mortality to NHWs but had higher risk of mechanical ventilation(aOR=1.15,95%CI:1.09-1.22)and AKI requiring dialysis(aOR=1.65,95%CI:1.54-1.76).Mean length of stay and cost were longest and highest for Hispanic patients.CONCLUSION Our study showed that there was higher mortality in Hispanic patients,and higher renal and respiratory complication in both NHB and Hispanic groups compared to NHW group.Future research identifying the causes of the observed differences in complications are required to inform targeted strategies that may mitigate modifiable risk factors and optimize early detection of organ failure to optimize outcomes in this population.
文摘BACKGROUND Bradycardia,renal failure,atrioventricular nodal blockade,shock,and hyper-kalemia(BRASH)syndrome is an acronym used to describe a constellation of BRASH.It is an underrecognized phenomenon that can be deadly if not appro-priately managed in a timely manner.This case highlights the importance of rapid diagnosis and reviews a multitude of treatment options in a uniquely severe case of BRASH syndrome.CASE SUMMARY We present a case of a 54-year-old male on a beta-blocker and angiotensin-con-verting enzyme inhibitor who presented with one day history of nausea,vomi-ting,and shortness of breath.Upon presentation,he was bradycardic and hypotensive,requiring transcutaneous pacing.Initial electrocardiogram showed atrial fibrillation with ventricular rate in 30’s.He was found to have acute kidney injury,hyperkalemia,and metabolic acidosis.He was successfully treated with multiple potassium lowering agents,continuous renal replacement therapy,four pressors,mechanical ventilation,and transvenous pacing with complete recovery prior to discharge.CONCLUSION Increased awareness of BRASH syndrome may improve outcomes through timely diagnosis and aggressive intervention.
基金financially supported by the National Natural Science Foundation of China(Grant No.51874207)the Natural Science Foundation of Shanxi Province(Grant Nos.202303021211042 and 202303011222006).
文摘This research employs micro-CT scanning technology to analyze the porosity,pore fractal dimension,and spatial variability of sandstone preheated to 600℃ and subsequently cooled in water at varying temperatures(20℃,60℃,100℃).The study investigates the mechanisms by which various factors influence thermal shock damage,focusing on the effects of cooling water temperature and the boiling phase transition.The objective is to develop a method for characterizing thermal shock damage that considers spatial variability.The findings indicate that thermal shock damage is limited to a shallow depth beneath the surface,with increased severity near the surface.The boiling phase transition significantly enhances the convective heat transfer coefficient,resulting in substantially higher thermal shock damage when cooled with 100℃ boiling water compared to 20℃ and 60℃ water.Furthermore,for the entire specimen,heating damage exceeds thermal shock damage,and the influence of thermal shock diminishes as specimen size increases.This study addresses the limitations of traditional methods for assessing thermal shock damage that disregard spatial variability and provides practical guidance for engineering projects to manage thermal shock damage more effectively.
文摘BACKGROUND Septic shock represents one of the most severe critical illness types,characterized by significant hemodynamic disorders and neuropsychiatric symptoms.This study aimed to investigate the association mechanism between hemodynamic indicators and neuropsychiatric symptoms in patients with septic shock,revealing potential pathophysiological connections.AIM To investigate the link between hemodynamic parameters and neuropsychiatric symptoms in septic shock.METHODS A retrospective case-control study involving 132 patients with septic shock.Multiple assessment tools were employed,including the Confusion Assessment Method,Hospital Anxiety and Depression Scale,Posttraumatic Stress Disorder Scale,and Mini-Mental State Examination,systematically evaluating patients’neuropsychiatric symptoms and hemodynamic indicators.RESULTS Patient mean age was 52.4±12.3 years,with 68.5%males.Multivariate analysis revealed significant correlations between neuropsychiatric symptom severity and mean arterial pressure<65 mmHg[odds ratio(OR)=2.7],lactate levels>4 mmol/L(OR=3.1),and elevated interleukin-6 inflammatory factors(OR=2.4).Neuropsychiatric symptom incidence rates were:Delirium 37.1%;anxiety 28.8%;depression 24.2%;and posttraumatic stress disorder 19.7%.CONCLUSION Hemodynamic disorders in patients with septic shock are closely associated with neuropsychiatric symptoms,influencing central nervous system function through complex inflammatory and neurotransmitter pathways.
基金supported by the Swedish Research Council(VR)under grant number 2020-05044by the research environment grant"Gravitational Radiation and Electromagnetic Astrophysical Transients"(GREAT)funded by the Swedish Research Council(VR)under Dnr 2016-06012+2 种基金by the Knut and Alice Wallenberg Foundation under grant Dnr.KAW 2019.0112by the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)under Germany's Excellence Strategy-EXC 2121"Quantum Universe"-390833306by the European Research Council(ERC)Advanced Grant INSPIRATION under the European Union's Horizon 2020 Research and Innovation Programme(Grant agreement No.101053985).
文摘We present and explore a new shock-capturing particle hydrodynamics approach.Our starting point is a commonly used discretization of smoothed particle hydrodynamics.We enhance this discretization with Roe’s approx-imate Riemann solver,we identify its dissipative terms,and in these terms,we use slope-limited linear reconstruction.All gradients needed for our method are calculated with linearly reproducing kernels that are constructed to enforce the two lowest-order consistency relations.We scrutinize our reproducing kernel implementation carefully on a“glass-like”particle distribution,and we find that constant and linear functions are recovered to machine precision.We probe our method in a series of challenging 3D benchmark problems ranging from shocks over instabilities to Schulz-Rinne-type vorticity-creating shocks.All of our simulations show excellent agreement with analytic/reference solutions.
文摘BACKGROUND Sepsis and septic shock pose critical public health challenges with high mortality,particularly in critical care.While racial differences in sepsis incidence are documented,the impact of race on sepsis outcomes remains inconsistent.AIM To evaluate racial disparities in clinical outcomes among patients hospitalized with septic shock,focusing on in-hospital mortality,length of stay(LOS),and hospitalization costs.METHODS We conducted a retrospective cohort study using the National Inpatient Sample database from 2016 to 2021.Patients diagnosed with septic shock were identified using ICD-10 code R65.21.The primary outcome was in-hospital mortality;secondary outcomes included trends in septic shock hospitalizations,mortality,length of stay,and cost of hospitalizations.RESULTS Among 3581504 hospitalizations for septic shock,the racial distribution was 67%Non-Hispanic White(NHW),15%Non-Hispanic Black(NHB),11%Hispanic,and 7%other groups,with a mean age of 66.3 years.In-hospital mortality was 33.6%,highest among other racial groups(36.7%).Mortality was stable across racial groups from 2016-2019 but rose sharply in 2020-2021,especially among Hispanic patients.Adjusted in-hospital mortality were higher for NHB and Hispanic compared to NHW patients.NHB patients had the longest LOS,while other racial groups incurred the highest cost of hospitalizations.CONCLUSION We found higher mortality among NHB,Hispanic,and other racial groups in septic shock patients,likely driven by higher risk of in-hospital complications among these racial groups.This highlights the need for future research to identify the factors contributing to the adverse outcomes in these populations.
