This paper focuses on the instability mechanism of an isolated pillar, caused by time-dependent skin degradation and strength heterogeneity. The time-dependent skin degradation is simulated with a non-linear rheologic...This paper focuses on the instability mechanism of an isolated pillar, caused by time-dependent skin degradation and strength heterogeneity. The time-dependent skin degradation is simulated with a non-linear rheological model capable of simulating tertiary creep, whereby two different pillar failure cases are investigated. The first case is of an isolated pillar in a deep hard rock underground mine and subjected to high stresses. The results show that pillar degradation is limited to the regions near the surface or the skin until two months after ore extraction. Afterwards degradation starts to extend deeper into the pillar, eventually leaving a highly-stressed pillar core due to stress transfer from the failed skin.Rockburst potential indices show that the risk increases exponentially at the core as time goes by. It is then demonstrated that the progressive skin degradation cannot be simulated with conventional strain-softening model assuming brittle failure. The parametric study with respect to the degree of heterogeneity reveals that heterogeneity is key to the occurrence of progressive skin degradation. The second case investigated in this study is pillar failure taking place in a very long period. Such failure becomes significantly important when assessing the risk for ground subsidence caused by pillar collapse in an abandoned mine. The analysis results demonstrate that the employed non-linear rheological model can simulate gradual skin degradation taking place over several hundred years. The percentage of damage zone volume within the pillar is merely 1% after a lapse of one days and increases to 50% after one hundred years, indicating a high risk for pillar collapse in the long term. The vertical displacements within the pillar also indicate the risk of subsidence. The proposed method is suitable for evaluating the risk of ground surface subsidence above an abandoned mine.展开更多
The deformation and failure of coal walls in front of a working face cause significant difficulties during mining operations.This study reveals the nonuniform distribution of bearing pressure in front of coal walls ba...The deformation and failure of coal walls in front of a working face cause significant difficulties during mining operations.This study reveals the nonuniform distribution of bearing pressure in front of coal walls based on in situ monitoring data and numerical simulation.Therefore,an eccentric compression mechanical model was established to study the deformation and failure characteristics of a coal wall.The slenderness ratio of the compression bar is introduced to define coal walls.The results showed that instability failure occurs when λ>λ_(c) and material failure occurs when λ≤λ_(c).The instability failure-type coal wall spalling was related to the mining height,eccentricity of roof pressure,the horizontal force,and the reaction moment of the floor.The material failure-type coal wall spalling was related to the cohesion,the internal friction angle of the coal,the upper pressure,and the horizontal force of coal walls.Unstable and destructive coal wall peeling usually occurs at a height of 0.5–0.6 times the mining height,while material damage to coal wall peeling is determined to occur within the range of 0.4-0.6 times the mining depth.The findings contribute to the understanding of the deformation and failure of coal walls.展开更多
Backfill is routinely adopted as a ground support measure for underground mines.However,ground stability enhancement by backfill has received limited research attention.This is likely to be because of the conventional...Backfill is routinely adopted as a ground support measure for underground mines.However,ground stability enhancement by backfill has received limited research attention.This is likely to be because of the conventional assumption that the fill material exhibits a significantly lower stiffness than the host rocks.Significantly,a recent pioneering work revealed the time-dependent ground stability around a backfilled stope with vertical walls through numerical modeling.In practice,underground stopes typically exhibit a higher or lower degree of inclination.This alters the stress state in peripheral rocks and may induce severe instability and dilution,particularly in stope-hanging walls.Hence,it is imperative to analyze the time-dependent ground stability of inclined backfilled stopes for backfill structure design.Therefore,comprehensive numerical simulations were performed using FLAC3D to address this knowledge deficiency by incorporating a coupled analysis of the backfill consolidation behavior and long-term creep deformation in surrounding rocks.The ground stability was evaluated based on the confinement effectiveness,strength-stress ratio,stress path relative to the yield surface,and time-dependent stress redistribution in the rocks.A parametric study revealed that the inclination angle of the backfilled stope reduced the confinement effectiveness in the host rocks when the wall creep was minor.This exacerbated the rock mass sloughing potential.However,a backfilled stope with a shallower dip angle achieved superior ground stability enhancement when the creep deformation was substantial,by applying a more significant compression on the backfill and effectively mobilizing its passive support performance during consolidation.Additional simulations were conducted to analyze the effects of stope height and width,mine depth,mechanical properties of rocks,backfill compressibility,and filling gap on the time-dependent stress redistribution and stability around the inclined backfilled stope.展开更多
Reservoir-induced landslides in China's Three Gorges Reservoir area are prone to tensile cracks due to the influenceof their own weight and fluctuationsin water levels.The presence of cracks indicates that the ten...Reservoir-induced landslides in China's Three Gorges Reservoir area are prone to tensile cracks due to the influenceof their own weight and fluctuationsin water levels.The presence of cracks indicates that the tensile stress in the area has exceeded the tensile strength of the soil,leading to local instability.To explore the impact of tensile failure behavior on the stability and failure modes of reservoir landslides,the Huangtupo Riverside Slump#1 is taken as a case study.By considering local tensile failure,potential tensile cracks are incorporated into the analysis via the limit equilibrium method and reliability theory.The reliability of landslides under different tensile failure scenarios is quantified.Strain-softening characteristics of the soil are combined to further analyze the failure transmission path of the landslide.Finally,these potential failure modes were validated through physical model tests.The results show that cracks developing at rear positions reduce the stability of the slope and increase the probability of instability.During the destruction process,retrogressive failures with multiple sliding surfaces are likely to occur.However,tensile failure at the forefront reduces the likelihood of an individual slide mass descending.Progressive failure results in both regular and skip transmission patterns.Additionally,cracks and water level changes can also lead to shifts in the positions of the most dangerous blocks.Therefore,in practical landslide analysis and prevention,it is necessary to consider local tensile damage and identify potential tensile crack locations in advance to optimize prevention measures and accurately evaluate landslide risk.展开更多
In deep coal mining,surrounding rock is subjected to both high in-situ stress and intense mining disturbances,leading to significant time-dependent behavior.Accurately capturing this behavior is essential for predicti...In deep coal mining,surrounding rock is subjected to both high in-situ stress and intense mining disturbances,leading to significant time-dependent behavior.Accurately capturing this behavior is essential for predicting long-term roadway stability,necessitating the development of a reliable constitutive creep model and numerical simulation approach.In this study,creep experiments were conducted on pre-damaged rock with varying initial damage levels to investigate the time-dependent mechanical properties.Based on the experimental results,an accelerated-creep criterion was proposed,and an elastic-viscoplastic creep damage model(EVPCD)was established that simultaneously considers the effects of time-dependent damage and instantaneous damage caused by stress disturbances on rock creep behavior.Subsequently,the effectiveness of the proposed creep model was verified using experimental data,and the secondary development of the EVPCD model was completed based on the FLAC3D platform.Following this,a long-term stability analysis method of deep surrounding rock that accounts for excavation-and mining-induced disturbances was proposed.Using the main roadway of Xutuan Coal Mine as a case study,numerical simulations were carried out to investigate the time-dependent deformation and failure characteristics of the surrounding rock following excavation and mining disturbance.Combined with on-site monitoring of the surrounding rock damage areas,the results indicate that the EVPCD outperforms the CVISC and Nishihara models in predicting the time-dependent behavior of deep surrounding rock.展开更多
A multi-stage stress relaxation test was performed on a granodiorite sample to understand the deformation process prior to the macroscopic failure of brittle rocks,as well as the transient response during stress relax...A multi-stage stress relaxation test was performed on a granodiorite sample to understand the deformation process prior to the macroscopic failure of brittle rocks,as well as the transient response during stress relaxation.Distributed optical fiber sensing was used to measure strains across the sample surface by helically wrapping the single-mode fiber around the cylindrical sample.Close agreement was observed between the circumferential strains obtained from the optical fibers and the extensometer.The reconstructed full-field strain contours show strain heterogeneity from the crack closure phase,and the strains in the later deformation phase are dominantly localized within the former high-strain zone.The Gini coefficient was used to quantify the degree of strain localization and shows an initial increase during the crack closure phase,a decrease during the linear elastic phase,and a subsequent increase during the post-yielding phase.This behavior corresponds to a process of initial localization from an imperfect boundary condition,homogenization,and eventual relocalization prior to the macroscopic failure of the sample.The transient strain rate decay during the stress relaxation phase was quantified using the p-value in the“Omori-like"power law function.A higher initial stress at the onset of relaxation results in a lower p-value,indicating a slower strain rate decay.As the sample approaches macroscopic failure,the lowest p-value shifts from the most damaged zone to adjacent areas,suggesting stress redistribution or crack propagation in deformed crystalline rocks under stress relaxation conditions.展开更多
Background Frailty is common and significantly impacts prognosis in heart failure(HF). The Vulnerable Elders Survey-13(VES-13), widely used in oncogeriatrics and public health, remains unexplored as a frailty screenin...Background Frailty is common and significantly impacts prognosis in heart failure(HF). The Vulnerable Elders Survey-13(VES-13), widely used in oncogeriatrics and public health, remains unexplored as a frailty screening tool in HF outpatients. In this study, we prospectively evaluated VES-13 against a multimodal screening assessment in detecting frailty and predicting individual risk of adverse prognosis.Methods Frailty was assessed at the initial visit using both a multimodal approach, incorporating Barthel Index, Older American Resources and Services scale, Pfeiffer Test, abbreviated Geriatric Depression Scale, age > 85 years, lacking support systems,and VES-13. Patients scoring ≥ 3 on VES-13 or meeting at least one multimodal criterion were classified as frail. Endpoints included all-cause mortality, a composite of death or HF hospitalization, and recurrent HF hospitalizations.Results A total of 301 patients were evaluated. VES-13 identified 40.2% as frail and the multimodal assessment 33.2%. In Cox regression analyses, frailty identified by VES-13 showed greater prognostic significance than the multimodal assessment for allcause mortality(HR = 3.70 [2.15–6.33], P < 0.001 vs. 2.40 [1.46–4.0], P = 0.001) and the composite endpoint(HR = 3.13 [2.02–4.84], P< 0.001 vs. 1.96 [1.28–2.99], P = 0.002). Recurrent HF hospitalizations were four times more frequent in VES-13 frail patients while two times in those identified as frail by the multimodal assessment. Additionally, stratifying patients by VES-13 tertiles provided robust risk differentiation.Conclusions VES-13, a simple frailty tool, outperformed a comprehensive multimodal assessment and could be easily integrated into routine HF care, highlighting its clinical utility in identifying patients at risk for poor outcomes.展开更多
Heart failure(HF)is a complex clinical syndrome that promotes high morbidity and multi-systemic damage.Skeletal muscle can be directly affected by HF through a loss of physical capacity and various inflammatory,hormon...Heart failure(HF)is a complex clinical syndrome that promotes high morbidity and multi-systemic damage.Skeletal muscle can be directly affected by HF through a loss of physical capacity and various inflammatory,hormonal,and metabolic mechanisms observed in this cardiac condition,which collectively contribute to a high prevalence of sarcopenia in HF patients.Therefore,the aim of this review was to compile the main recent clinical and epidemiological data on muscle health in HF patients.Nine studies were selected from systematic reviews and clinical trials,which demonstrated a high prevalence of sarcopenia in patients with HF,particularly in males,hospitalized patients,the elderly,and those with HF with reduced ejection fraction.Oxidative stress markers and higher levels of natriuretic peptides were also observed in HF patients who exhibited damaged muscle parameters.Furthermore,the overall deterioration of prognosis in HF was associated with criteria defining sarcopenia,such as low muscle strength and lean mass loss.These findings reinforce the importance of evaluating skeletal muscle in HF patients,which can provide improvements in morbidity and functionality.展开更多
Wellbore drilling disturbs the equilibrium stress state in the rock mass,resulting in stress redistribution around the opening.Wellbore stability in the altered stress state is vital for engineering applications,as th...Wellbore drilling disturbs the equilibrium stress state in the rock mass,resulting in stress redistribution around the opening.Wellbore stability in the altered stress state is vital for engineering applications,as the wellbore instability results in cost overrun.Accurate estimation of rock mechanical properties,in-situ stresses,and required mud pressure is crucial for safe drilling.If the mud pressure is lower than required,the shear failure of the rock takes place,and conversely,if the mud pressure is higher than the upper limit,tensile failure occurs.A strength criterion that can accurately predict the mud pressure may help significantly reduce nonproductive time and cost in well drilling.The commonly used Mogi-Coulomb(MGC)failure criterion for estimating critical mud pressure neglects the few fundamental aspects of rock failure characteristics observed in the laboratory,such as nonlinear strength response in major-minor principal stress space and prediction of multiple failure stress values near the triaxial axial extension boundary.The present study uses the Modified Mohr-Coulomb true-triaxial failure criterion(MMC_TT),which predicts the strength of rock better than the MGC in laboratory true-triaxial tests to overcome the limitations.Moreover,based on the data from previously published five vertical wells in the Krishna-Godavari basin(K-G basin),an empirical relationship is proposed to obtain the strength parameters for the MMC_TT criterion for shaley sedimentary rocks as the existing correlations do not cater for the parameters required for MMC_TT criterion.The comparative study of the MMC_TT with MGC,Modified Mohr-Coulomb triaxial,and Mohr-Coulomb failure criteria,showed that for most of the K-G basin wells,the MMC_TT criterion predicted close to the MGC.However,for well-13,the MMC_TT criterion results are closer to the mud pressure used in actual drilling than the MGC.展开更多
With the integration of large-scale renewable energy sources(RESs),the line commutated converter(LCC)based high-voltage direct-current(HVDC)inverter side suffers from degraded grid strength and escalating commutation ...With the integration of large-scale renewable energy sources(RESs),the line commutated converter(LCC)based high-voltage direct-current(HVDC)inverter side suffers from degraded grid strength and escalating commutation failure(CF)risks.In comparison with the widely used grid-following(GFL)RESs,grid-forming(GFM)RESs exhibit the favorable characteristics of voltage sources.Therefore,the hybrid operation of GFL-/GFM-RESs holds great potential in voltage support and may help CF suppression.This paper first analyzes the impacts of RESs on the first and subsequent CFs,respectively.It reveals that GFM-RESs alleviate the deterioration of grid voltage induced by GFL-RESs,thereby suppressing the first CF.However,current fault ride-through controls of RESs cannot fulfill the reactive power dynamic demand during the CF recovery process and rarely help mitigate subsequent CFs.Moreover,the limited overcurrent capability of GFM-RES hinders its ability to ride through CF.Based on the mechanism analysis,a CF suppression strategy based on the hybrid GFL/GFM operation is proposed.The proposed strategy optimized the controls of RESs to fulfill reactive power dynamics and offer voltage support during the CF process.Case studies are undertaken on the studied system and the CIGRE benchmark,respectively.The simulation results confirm the effectiveness of the proposed strategy for suppressing CF.展开更多
Formation control of multiple spacecraft has attracted extensive research attention.However,achieving reliable performance under sensor failures remains a significant challenge.This paper develops an integrated framew...Formation control of multiple spacecraft has attracted extensive research attention.However,achieving reliable performance under sensor failures remains a significant challenge.This paper develops an integrated framework that jointly designs distributed observers and local controllers to ensure robust formation control in the presence of external disturbances and sensor malfunctions.Treating the spacecraft formation as a single interconnected system,each spacecraft constructs a distributed observer that estimates the overall system state by incorporating both its own measurements and the predicted control information shared among the spacecraft.Based on the observer estimates,a local control law is synthesized to maintain the desired formation.Rigorous theoretical analysis and numerical simulations demonstrate that the proposed integrated approach effectively guarantees formation stability and resilience against sensor failures and disturbances.展开更多
The axial load-bearing capacity of grouted anchorage systems is critical for rock reinforcement and reflects the interactions among system components.Hence,the mechanical response and failure characteristics of the an...The axial load-bearing capacity of grouted anchorage systems is critical for rock reinforcement and reflects the interactions among system components.Hence,the mechanical response and failure characteristics of the anchorage system under axial loading are of vital importance.They serve as the foundation for establishing the mechanical model of the anchorage system and provide significant guidance for the optimization design of bolts and the assessment of anchorage conditions.However,as the most widely used research method,current pullout tests have not paid sufficient attention to simulating actual rock mass stiffness,have not fully revealed the radial mechanical response during the pullout process,and have not clarified the locations and modes of pullout failure.To address these issues,a testing method simulating hard rock stiffness and strength was developed using elasticity and stiffness equivalence theories.Tests revealed three anchorage failure modes under equivalent hard rock stiffness:tooth cutting,sliding,and sliding-tooth cutting composite failure,with the composite failure being dominant.The pullout load-displacement curves exhibited bimodal patterns for composite failure and single peaks for tooth cutting and sliding failures.Post-peak softening showed up-convex curves for tooth cutting and down-concave curves for sliding failure,while bolt yielding displayed distinct plateaus.The radial stress trends at the rock-grout interface paralleled pullout load curves,with sliding failure exhibiting approximately 10 MPa lower peak radial stress compared to tooth cutting failure.Anchorage length most strongly affected peak load,while grout properties predominantly governed failure mode.展开更多
Objective:This integrative review aims to synthesize observational evidence on the prevalence,predictors,and psychosocial correlates of death anxiety in patients with hear t failure(HF).Methods:A comprehensive literat...Objective:This integrative review aims to synthesize observational evidence on the prevalence,predictors,and psychosocial correlates of death anxiety in patients with hear t failure(HF).Methods:A comprehensive literature search was conducted using 5 major databases:Scopus,Pub Med,Science Direct,Embase,and Pro Quest.Inclusion criteria were primary research studies published in English between January 2014 and March 2025 that quantitatively assessed death anxiety among patients with HF and explored its associations with demographic,clinical,or psychosocial variables.Results:A total of 12 eligible studies were identified and systematically reviewed,revealing that death anxiety is moderate to high among most samples.Key predictors of this anxiety included older age,feelings of loneliness,low socioeconomic status,and longer duration of HF.Additionally,several studies highlighted protective factors such as spiritual orientation,religious coping,and resilience.Interventions,including cognitive-behavioral therapy(CBT)and illness perception training,showed significant reductions in death anxiety.Conclusions:Death anxiety is a prevalent and impactful concern among Patients with HF,influenced by both individual and contextual factors.Routine assessment and integration of psychosocial and spiritual care—alongside evidence-based psychological interventions—are essential to address this critical aspect of HF management.展开更多
AIM:To investigate the underlying causes of surgical failure and reoperation management in patients with rhegmatogenous retinal detachment(RRD)who underwent scleral buckle surgery at our institution.METHODS:This was a...AIM:To investigate the underlying causes of surgical failure and reoperation management in patients with rhegmatogenous retinal detachment(RRD)who underwent scleral buckle surgery at our institution.METHODS:This was a single-center,retrospective,descriptive study.The clinical data of 368 patients(387 eyes)with RRD who underwent scleral buckling(SB)surgery between August 2013 and July 2023 at our institution were collected.The aim was to analyze the causes of recurrence and the rationale for selecting reoperation methods.RESULTS:Totally 368 patients(387 eyes)were included in the analysis,comprising 222 males and 146 females.The average age was 30.26±14.18 years,and the mean follow-up duration was(48.33±20.39)mo.The success rate of SB surgery was 90.2%.Recurrent retinal detachment occurred in 38 eyes.Based on surgical records,the causes of SB failure were analyzed.The recurrence causes included abnormal compression ridge position(position,height,or width)in 14 eyes(36.8%,14/38),hole omission in 11 eyes(29.0%,11/38),proliferative vitreoretinopathy(PVR)in 10 eyes(26.3%,10/38),and new holes in 3 eyes(7.9%,3/38).Among these,8 eyes(21.1%,8/38)underwent repeat SB surgery,while the remaining 30 eyes(78.9%,30/38)underwent pars plana vitrectomy(PPV).Regarding tamponade agents,silicone oil was used in 11 eyes(36.7%,11/30),C_(3)F_(8) gas in 12 eyes(40.0%,12/30),and sterile air in 7 eyes(23.3%,7/30).CONCLUSION:SB surgery demonstrates a high success rate in the treatment of RRD.However,abnormal compression ridge position,missed holes during surgery,and PVR are the primary causes of SB failure.After addressing the reasons for failure,re-SB surgery or PPV can be effective alternatives.展开更多
Objective: To conduct a scoping review of kinesiophobia among primary caregivers of patients with chronic heart failure (CHF). Methods: Following a scoping review methodological framework, PubMed, Web of Science, Emba...Objective: To conduct a scoping review of kinesiophobia among primary caregivers of patients with chronic heart failure (CHF). Methods: Following a scoping review methodological framework, PubMed, Web of Science, Embase, Cochrane Library, CINAHL, CNKI, SinoMed, Wanfang, and VIP were searched from inception to 30 June 2025. Relevant studies on kinesiophobia in primary caregivers of CHF patients were identified, summarized, and analyzed. Results: A total of 24 studies were included. Caregivers generally showed insufficient exercise-related knowledge, particularly regarding appropriate exercise intensity and risk recognition. At the cognitive-affective level, caregivers exhibited a pronounced “substitutive” kinesiophobia, characterized by excessive worry about potential adverse events induced by patients’ physical activity. At the behavioral level, this was reflected in restricting patients’ activities and avoiding assisting with exercise, which in turn reduced patients’ adherence to cardiac rehabilitation. Conclusion: Kinesiophobia among primary caregivers of CHF patients arises mainly from cognitive deficits and protective psychological mechanisms. Individualized education and professional guidance are needed to enhance caregivers’ exercise management competence and thereby optimize patients’ rehabilitation outcomes.展开更多
BACKGROUND Anxiety,depression,and other negative emotions are common among patients with chronic renal failure(CRF).Analyzing the factors related to negative emotions is necessary to provide targeted nursing care.AIM ...BACKGROUND Anxiety,depression,and other negative emotions are common among patients with chronic renal failure(CRF).Analyzing the factors related to negative emotions is necessary to provide targeted nursing care.AIM To explore the correlations among life satisfaction,pleasure levels,and negative emotions in patients with CRF.METHODS One hundred patients with CRF who received therapy at the First Affiliated Hospital of Jinzhou Medical University between December 2022 and February 2025 were included.The Depression,Anxiety,and Stress Scale(DASS-21),Satisfaction with Life Scale(SWLS),and Temporal Experience of Pleasure Scale(TEPS)were used to evaluate negative emotions,life satisfaction,and pleasure level,respectively.Pearson’s correlation coefficient analyzed the correlation between life satisfaction,pleasure level,and negative emotions.Linear regression analysis identified the factors affecting negative emotions.RESULTS The average DASS-21 score among patients with CRF was 51.90±2.30,with subscale scores of 17.90±1.50 for depression,18.53±1.18 for anxiety,and 15.47±2.36 for stress,all significantly higher than the domestic norm(P<0.05).The average SWLS score was 22.17±4.90.Correlation analysis revealed a negative correlation between the SWLS and total DASS-21 scores(P<0.05),but not with the individual depression,anxiety,or stress dimensions.The average TEPS score was 67.80±8.34.TEPS scores were negatively correlated with the DASS-21 score and the stress dimension(P<0.05),but not with depression or anxiety.Linear regression analysis showed that TEPS scores significantly influenced DASS-21 scores(P<0.05).CONCLUSION Patients with CRF experience high levels of negative emotions,which are negatively correlated with life satisfaction and pleasure.Furthermore,pleasure level had an impact on negative emotions.展开更多
BACKGROUND Congenital hypothyroidism(CH)is a common condition in both preterm and term infants characterized by either thyroid gland absence or hypofunctionality.The clinical association of refractory lactic acidosis ...BACKGROUND Congenital hypothyroidism(CH)is a common condition in both preterm and term infants characterized by either thyroid gland absence or hypofunctionality.The clinical association of refractory lactic acidosis and heart failure has rarely been observed in cases of pediatric patients with CH pathology.Here,we explored the etiological relationship between CH,heart failure,and refractory lactic acidosis to reflect the importance of thyroid function screening in neonates with heart disease.CASE SUMMARY A 33-day-old extremely premature female infant presented with tachypnea,respiratory distress,recurrent infections,and abdominal distension postnatal.On admission to our facility,she had cardiomegaly,hepatomegaly,and lactic acidosis(revealed on blood gas analysis),with lactate progressively rising to 25 mmol/L.Chest radiographs showed pulmonary congestion,while echocardiography revealed cardiac enlargement,left ventricular wall thickening,and pericardial effusion.Initial management aimed at correcting acidosis and treating heart failure proved ineffective.After reassessment,thyroid function tests showed significantly decreased triiodothyronine,free triiodothyronine,thyroxine,and free thyroxine levels,with a significantly increased thyroidstimulating hormone level,confirming a CH diagnosis.Levothyroxine was administered,resulting in rapid correction of lactic acidosis and gradual improvement of thyroid function and systemic symptoms,culminating in full recovery and discharge.We also reviewed the relevant literature on thyroid and cardiac dysfunctions in order to explore their deeper association.CONCLUSION This case links CH-induced heart failure with refractory lactic acidosis,urging prompt thyroid screening in affected neonates to reduce mortality.展开更多
Objective:Heart failure(HF)is a complex clinical syndrome that affects nearly 64 million individuals globally.Frequent hospital readmissions lead to poor health outcomes,impact quality of life(QoL),and are associated ...Objective:Heart failure(HF)is a complex clinical syndrome that affects nearly 64 million individuals globally.Frequent hospital readmissions lead to poor health outcomes,impact quality of life(QoL),and are associated with high mortality rates.This study assessed readmissions,mortality,and QoL outcomes in patients with HF in a tertiary care hospital setting.Methods:Patients aged≥18 years with HF,who visited the tertiary care hospital in Karad,India were included in the study(November2019 to October 2021).Demographics,disease characteristics,and condition at discharge were recorded using the medical records of patients.The quantitative data included readmission rates and mortality rates.The qualitative aspects describing patients'QoL were assessed using a patient-reported 21-question QoL questionnaire.Results:A total of 98 patients,predominantly male(63.3%),with a mean age of 62.9 years were included.The majority of the patients(80.6%)required<15 days of hospitalization.The 2-year readmission rate was 24.4%,while the mortality rate was 43.9%.Self-care pattern showed that patients seemed to be taking mild to average care while taking good care was rare.The QoL data showed that 22.4% were living a good quality life,44.9% average,while 32.7% were living a low-quality life.Better education and better self-care were associated with a low rate of readmission.Conclusions:We were able to assess the incidence of readmission,mortality,and QoL in patients with HF in a tertiary care hospital setting.The study showed that HF impacts patients'physical,emotional,and psychological wellbeing.展开更多
According to the dynamic interaction process between cyber flow and power flow in grid cyber-physical systems(GCPS),attackers could gradually trigger large-scale power failures through cooperative cyber-attacks,subseq...According to the dynamic interaction process between cyber flow and power flow in grid cyber-physical systems(GCPS),attackers could gradually trigger large-scale power failures through cooperative cyber-attacks,subsequently forming cross-domain cascading failures(CDCF)that cross cyber-domain and power-domain and endanger the stable running of GCPS.To reveal the evolutionary mechanism of CDCF,an optimal attack scheme evaluation method is proposed,considering the spatiotemporal synergy of multiple attack-event-chains.First,in accordance with the spatiotemporal synergy of multiple attack-event-chains,the CDCF evolutionary mechanism is analyzed from the attackers'perspective,and a CDCF mathematical model is established.Furthermore,an attack graph model of CDCF evolution and its hazard calculation method are proposed.Then,the attackers'decision-making process for the optimal attack scheme of CDCF is deduced based on the attack graph model.Finally,both the evaluation and implementation processes of the optimal attack scheme are simulated in the GCPS experimental system based on IEEE-39 bus systems.展开更多
Dynamic disturbances with various frequencies could trigger different failure modes of deep excavations.Superimposed on this static stress are dynamic disturbances due to various dynamic vibrations,e.g.excavation blas...Dynamic disturbances with various frequencies could trigger different failure modes of deep excavations.Superimposed on this static stress are dynamic disturbances due to various dynamic vibrations,e.g.excavation blasting,blasting,tunnel boring machine(TBM)vibration,rockburst wave,earthquakes.Specifically,these dynamic sources are characterized by a wide range of wave frequencies f,resulting in differences in failure modes.A series of true-triaxial compression tests were conducted on granite to simulate the excavation-induced stress path in three-dimensional(3D)stresses.Subsequently,a dynamic disturbance with various frequencies was applied to a cuboid specimen,to reveal the behavior associated with brittle failure.The dynamic disturbance with frequencies f of 5 Hz,10 Hz,and 40 Hz generates less disturbed energy components in the granite together with higher peak strength.However,dynamic disturbances with f of 20 Hz and 30 Hz resulted in a lower peak strength;the peak strength of the rock increases sp albeit it decreases at first,then increases.This U-shaped phenomenon relates to the natural frequency of the granite under such stress conditions.Different rock lithologies consisting of diverse mineral composition,respond differently to each sensitive resonance frequency.Interestingly,the weak disturbance stress with a high frequency f and low amplitude A increases the ratio of crack damage to peak strength(scd/sp)in the granite.This leads to the inhibition of the expansion of the granite during the dynamic disturbance process.Multiple penetrating tensileeshear cracks appear in the s3-direction as the disturbance frequency f increases.展开更多
基金financially supported by the Natural Science and Engineering Research Council of Canada (NSERC) in partnership with Vale Ltd–Sudbury Operations, Canada, under the Collaborative Research and Development Program
文摘This paper focuses on the instability mechanism of an isolated pillar, caused by time-dependent skin degradation and strength heterogeneity. The time-dependent skin degradation is simulated with a non-linear rheological model capable of simulating tertiary creep, whereby two different pillar failure cases are investigated. The first case is of an isolated pillar in a deep hard rock underground mine and subjected to high stresses. The results show that pillar degradation is limited to the regions near the surface or the skin until two months after ore extraction. Afterwards degradation starts to extend deeper into the pillar, eventually leaving a highly-stressed pillar core due to stress transfer from the failed skin.Rockburst potential indices show that the risk increases exponentially at the core as time goes by. It is then demonstrated that the progressive skin degradation cannot be simulated with conventional strain-softening model assuming brittle failure. The parametric study with respect to the degree of heterogeneity reveals that heterogeneity is key to the occurrence of progressive skin degradation. The second case investigated in this study is pillar failure taking place in a very long period. Such failure becomes significantly important when assessing the risk for ground subsidence caused by pillar collapse in an abandoned mine. The analysis results demonstrate that the employed non-linear rheological model can simulate gradual skin degradation taking place over several hundred years. The percentage of damage zone volume within the pillar is merely 1% after a lapse of one days and increases to 50% after one hundred years, indicating a high risk for pillar collapse in the long term. The vertical displacements within the pillar also indicate the risk of subsidence. The proposed method is suitable for evaluating the risk of ground surface subsidence above an abandoned mine.
基金Youth Innovation Team of Shandong Higher Education Institutions,Grant/Award Number:2022KJ214Shandong Postdoctoral Science Foundation,Grant/Award Number:SDCXZG‐202303031+2 种基金China Postdoctoral Science Foundation,Grant/Award Number:2023M732109National Natural Science Foundation of China,Grant/Award Number:52209141Natural Science Foundation of Shandong Province,China,Grant/Award Number:ZR2021QE069。
文摘The deformation and failure of coal walls in front of a working face cause significant difficulties during mining operations.This study reveals the nonuniform distribution of bearing pressure in front of coal walls based on in situ monitoring data and numerical simulation.Therefore,an eccentric compression mechanical model was established to study the deformation and failure characteristics of a coal wall.The slenderness ratio of the compression bar is introduced to define coal walls.The results showed that instability failure occurs when λ>λ_(c) and material failure occurs when λ≤λ_(c).The instability failure-type coal wall spalling was related to the mining height,eccentricity of roof pressure,the horizontal force,and the reaction moment of the floor.The material failure-type coal wall spalling was related to the cohesion,the internal friction angle of the coal,the upper pressure,and the horizontal force of coal walls.Unstable and destructive coal wall peeling usually occurs at a height of 0.5–0.6 times the mining height,while material damage to coal wall peeling is determined to occur within the range of 0.4-0.6 times the mining depth.The findings contribute to the understanding of the deformation and failure of coal walls.
基金funding support from the National Natural Science Foundation of China(Nos.52304101 and 52204153)the China Postdoctoral Science Foundation(No.2023MD734215)+2 种基金the Youth Talent Support Program of Xi’an Association for Science and Technology(No.959202413070)the Key Research and Development Program of Shaanxi(No.2023-LL-QY-07)the Key Research and Development Program of Zhejiang(No.2023C03182).
文摘Backfill is routinely adopted as a ground support measure for underground mines.However,ground stability enhancement by backfill has received limited research attention.This is likely to be because of the conventional assumption that the fill material exhibits a significantly lower stiffness than the host rocks.Significantly,a recent pioneering work revealed the time-dependent ground stability around a backfilled stope with vertical walls through numerical modeling.In practice,underground stopes typically exhibit a higher or lower degree of inclination.This alters the stress state in peripheral rocks and may induce severe instability and dilution,particularly in stope-hanging walls.Hence,it is imperative to analyze the time-dependent ground stability of inclined backfilled stopes for backfill structure design.Therefore,comprehensive numerical simulations were performed using FLAC3D to address this knowledge deficiency by incorporating a coupled analysis of the backfill consolidation behavior and long-term creep deformation in surrounding rocks.The ground stability was evaluated based on the confinement effectiveness,strength-stress ratio,stress path relative to the yield surface,and time-dependent stress redistribution in the rocks.A parametric study revealed that the inclination angle of the backfilled stope reduced the confinement effectiveness in the host rocks when the wall creep was minor.This exacerbated the rock mass sloughing potential.However,a backfilled stope with a shallower dip angle achieved superior ground stability enhancement when the creep deformation was substantial,by applying a more significant compression on the backfill and effectively mobilizing its passive support performance during consolidation.Additional simulations were conducted to analyze the effects of stope height and width,mine depth,mechanical properties of rocks,backfill compressibility,and filling gap on the time-dependent stress redistribution and stability around the inclined backfilled stope.
基金supported by the Major Program of National Natural Science Foundation of China(Grant No.42090055)the National Key ScientificInstruments and Equipment Development Projects of China(Grant No.41827808)the National Nature Science Foundation of China(Grant No.42207216).
文摘Reservoir-induced landslides in China's Three Gorges Reservoir area are prone to tensile cracks due to the influenceof their own weight and fluctuationsin water levels.The presence of cracks indicates that the tensile stress in the area has exceeded the tensile strength of the soil,leading to local instability.To explore the impact of tensile failure behavior on the stability and failure modes of reservoir landslides,the Huangtupo Riverside Slump#1 is taken as a case study.By considering local tensile failure,potential tensile cracks are incorporated into the analysis via the limit equilibrium method and reliability theory.The reliability of landslides under different tensile failure scenarios is quantified.Strain-softening characteristics of the soil are combined to further analyze the failure transmission path of the landslide.Finally,these potential failure modes were validated through physical model tests.The results show that cracks developing at rear positions reduce the stability of the slope and increase the probability of instability.During the destruction process,retrogressive failures with multiple sliding surfaces are likely to occur.However,tensile failure at the forefront reduces the likelihood of an individual slide mass descending.Progressive failure results in both regular and skip transmission patterns.Additionally,cracks and water level changes can also lead to shifts in the positions of the most dangerous blocks.Therefore,in practical landslide analysis and prevention,it is necessary to consider local tensile damage and identify potential tensile crack locations in advance to optimize prevention measures and accurately evaluate landslide risk.
基金funded by the National Natural Science Foundation of China(Nos.52004098,U24B2041,and 52274079)the Key Research and Development Program of Henan Province(No.251111320400)+1 种基金the Key Research Project Plan for Higher Education Institutions in Henan Province(Nos.24A570006 and 25A570002)the Scientific and Technological Research Project in Henan Province(No.242102320061).
文摘In deep coal mining,surrounding rock is subjected to both high in-situ stress and intense mining disturbances,leading to significant time-dependent behavior.Accurately capturing this behavior is essential for predicting long-term roadway stability,necessitating the development of a reliable constitutive creep model and numerical simulation approach.In this study,creep experiments were conducted on pre-damaged rock with varying initial damage levels to investigate the time-dependent mechanical properties.Based on the experimental results,an accelerated-creep criterion was proposed,and an elastic-viscoplastic creep damage model(EVPCD)was established that simultaneously considers the effects of time-dependent damage and instantaneous damage caused by stress disturbances on rock creep behavior.Subsequently,the effectiveness of the proposed creep model was verified using experimental data,and the secondary development of the EVPCD model was completed based on the FLAC3D platform.Following this,a long-term stability analysis method of deep surrounding rock that accounts for excavation-and mining-induced disturbances was proposed.Using the main roadway of Xutuan Coal Mine as a case study,numerical simulations were carried out to investigate the time-dependent deformation and failure characteristics of the surrounding rock following excavation and mining disturbance.Combined with on-site monitoring of the surrounding rock damage areas,the results indicate that the EVPCD outperforms the CVISC and Nishihara models in predicting the time-dependent behavior of deep surrounding rock.
基金support of her postdoctoral research at the GFZ Helmholtz Centre for Geosciences.P.Pan acknowledges the financial support of the National Natural Science Foundation of China(Grant No.52339001)H.Hofmann and Y.Ji acknowledge the financial support of the Helmholtz Association's Initiative and Networking Fund for the Helmholtz Young Investigator Group ARES(contract number VH-NG-1516).
文摘A multi-stage stress relaxation test was performed on a granodiorite sample to understand the deformation process prior to the macroscopic failure of brittle rocks,as well as the transient response during stress relaxation.Distributed optical fiber sensing was used to measure strains across the sample surface by helically wrapping the single-mode fiber around the cylindrical sample.Close agreement was observed between the circumferential strains obtained from the optical fibers and the extensometer.The reconstructed full-field strain contours show strain heterogeneity from the crack closure phase,and the strains in the later deformation phase are dominantly localized within the former high-strain zone.The Gini coefficient was used to quantify the degree of strain localization and shows an initial increase during the crack closure phase,a decrease during the linear elastic phase,and a subsequent increase during the post-yielding phase.This behavior corresponds to a process of initial localization from an imperfect boundary condition,homogenization,and eventual relocalization prior to the macroscopic failure of the sample.The transient strain rate decay during the stress relaxation phase was quantified using the p-value in the“Omori-like"power law function.A higher initial stress at the onset of relaxation results in a lower p-value,indicating a slower strain rate decay.As the sample approaches macroscopic failure,the lowest p-value shifts from the most damaged zone to adjacent areas,suggesting stress redistribution or crack propagation in deformed crystalline rocks under stress relaxation conditions.
文摘Background Frailty is common and significantly impacts prognosis in heart failure(HF). The Vulnerable Elders Survey-13(VES-13), widely used in oncogeriatrics and public health, remains unexplored as a frailty screening tool in HF outpatients. In this study, we prospectively evaluated VES-13 against a multimodal screening assessment in detecting frailty and predicting individual risk of adverse prognosis.Methods Frailty was assessed at the initial visit using both a multimodal approach, incorporating Barthel Index, Older American Resources and Services scale, Pfeiffer Test, abbreviated Geriatric Depression Scale, age > 85 years, lacking support systems,and VES-13. Patients scoring ≥ 3 on VES-13 or meeting at least one multimodal criterion were classified as frail. Endpoints included all-cause mortality, a composite of death or HF hospitalization, and recurrent HF hospitalizations.Results A total of 301 patients were evaluated. VES-13 identified 40.2% as frail and the multimodal assessment 33.2%. In Cox regression analyses, frailty identified by VES-13 showed greater prognostic significance than the multimodal assessment for allcause mortality(HR = 3.70 [2.15–6.33], P < 0.001 vs. 2.40 [1.46–4.0], P = 0.001) and the composite endpoint(HR = 3.13 [2.02–4.84], P< 0.001 vs. 1.96 [1.28–2.99], P = 0.002). Recurrent HF hospitalizations were four times more frequent in VES-13 frail patients while two times in those identified as frail by the multimodal assessment. Additionally, stratifying patients by VES-13 tertiles provided robust risk differentiation.Conclusions VES-13, a simple frailty tool, outperformed a comprehensive multimodal assessment and could be easily integrated into routine HF care, highlighting its clinical utility in identifying patients at risk for poor outcomes.
文摘Heart failure(HF)is a complex clinical syndrome that promotes high morbidity and multi-systemic damage.Skeletal muscle can be directly affected by HF through a loss of physical capacity and various inflammatory,hormonal,and metabolic mechanisms observed in this cardiac condition,which collectively contribute to a high prevalence of sarcopenia in HF patients.Therefore,the aim of this review was to compile the main recent clinical and epidemiological data on muscle health in HF patients.Nine studies were selected from systematic reviews and clinical trials,which demonstrated a high prevalence of sarcopenia in patients with HF,particularly in males,hospitalized patients,the elderly,and those with HF with reduced ejection fraction.Oxidative stress markers and higher levels of natriuretic peptides were also observed in HF patients who exhibited damaged muscle parameters.Furthermore,the overall deterioration of prognosis in HF was associated with criteria defining sarcopenia,such as low muscle strength and lean mass loss.These findings reinforce the importance of evaluating skeletal muscle in HF patients,which can provide improvements in morbidity and functionality.
文摘Wellbore drilling disturbs the equilibrium stress state in the rock mass,resulting in stress redistribution around the opening.Wellbore stability in the altered stress state is vital for engineering applications,as the wellbore instability results in cost overrun.Accurate estimation of rock mechanical properties,in-situ stresses,and required mud pressure is crucial for safe drilling.If the mud pressure is lower than required,the shear failure of the rock takes place,and conversely,if the mud pressure is higher than the upper limit,tensile failure occurs.A strength criterion that can accurately predict the mud pressure may help significantly reduce nonproductive time and cost in well drilling.The commonly used Mogi-Coulomb(MGC)failure criterion for estimating critical mud pressure neglects the few fundamental aspects of rock failure characteristics observed in the laboratory,such as nonlinear strength response in major-minor principal stress space and prediction of multiple failure stress values near the triaxial axial extension boundary.The present study uses the Modified Mohr-Coulomb true-triaxial failure criterion(MMC_TT),which predicts the strength of rock better than the MGC in laboratory true-triaxial tests to overcome the limitations.Moreover,based on the data from previously published five vertical wells in the Krishna-Godavari basin(K-G basin),an empirical relationship is proposed to obtain the strength parameters for the MMC_TT criterion for shaley sedimentary rocks as the existing correlations do not cater for the parameters required for MMC_TT criterion.The comparative study of the MMC_TT with MGC,Modified Mohr-Coulomb triaxial,and Mohr-Coulomb failure criteria,showed that for most of the K-G basin wells,the MMC_TT criterion predicted close to the MGC.However,for well-13,the MMC_TT criterion results are closer to the mud pressure used in actual drilling than the MGC.
基金supported by the National Natural Science Foundation of China under Grant 52225704 and Grant U23B20120.
文摘With the integration of large-scale renewable energy sources(RESs),the line commutated converter(LCC)based high-voltage direct-current(HVDC)inverter side suffers from degraded grid strength and escalating commutation failure(CF)risks.In comparison with the widely used grid-following(GFL)RESs,grid-forming(GFM)RESs exhibit the favorable characteristics of voltage sources.Therefore,the hybrid operation of GFL-/GFM-RESs holds great potential in voltage support and may help CF suppression.This paper first analyzes the impacts of RESs on the first and subsequent CFs,respectively.It reveals that GFM-RESs alleviate the deterioration of grid voltage induced by GFL-RESs,thereby suppressing the first CF.However,current fault ride-through controls of RESs cannot fulfill the reactive power dynamic demand during the CF recovery process and rarely help mitigate subsequent CFs.Moreover,the limited overcurrent capability of GFM-RES hinders its ability to ride through CF.Based on the mechanism analysis,a CF suppression strategy based on the hybrid GFL/GFM operation is proposed.The proposed strategy optimized the controls of RESs to fulfill reactive power dynamics and offer voltage support during the CF process.Case studies are undertaken on the studied system and the CIGRE benchmark,respectively.The simulation results confirm the effectiveness of the proposed strategy for suppressing CF.
基金supported by the National Natural Science Foundation of China(62088101,62522307,62273045,U2341213)Beijing Nova Program(20230484481)。
文摘Formation control of multiple spacecraft has attracted extensive research attention.However,achieving reliable performance under sensor failures remains a significant challenge.This paper develops an integrated framework that jointly designs distributed observers and local controllers to ensure robust formation control in the presence of external disturbances and sensor malfunctions.Treating the spacecraft formation as a single interconnected system,each spacecraft constructs a distributed observer that estimates the overall system state by incorporating both its own measurements and the predicted control information shared among the spacecraft.Based on the observer estimates,a local control law is synthesized to maintain the desired formation.Rigorous theoretical analysis and numerical simulations demonstrate that the proposed integrated approach effectively guarantees formation stability and resilience against sensor failures and disturbances.
基金supported by the National Natural Science Foundation of China(Grant No.52279116)the Key Projects of the Yalong River Joint Fund of the National Natural Science Foundation of China(Grant No.U1865203).
文摘The axial load-bearing capacity of grouted anchorage systems is critical for rock reinforcement and reflects the interactions among system components.Hence,the mechanical response and failure characteristics of the anchorage system under axial loading are of vital importance.They serve as the foundation for establishing the mechanical model of the anchorage system and provide significant guidance for the optimization design of bolts and the assessment of anchorage conditions.However,as the most widely used research method,current pullout tests have not paid sufficient attention to simulating actual rock mass stiffness,have not fully revealed the radial mechanical response during the pullout process,and have not clarified the locations and modes of pullout failure.To address these issues,a testing method simulating hard rock stiffness and strength was developed using elasticity and stiffness equivalence theories.Tests revealed three anchorage failure modes under equivalent hard rock stiffness:tooth cutting,sliding,and sliding-tooth cutting composite failure,with the composite failure being dominant.The pullout load-displacement curves exhibited bimodal patterns for composite failure and single peaks for tooth cutting and sliding failures.Post-peak softening showed up-convex curves for tooth cutting and down-concave curves for sliding failure,while bolt yielding displayed distinct plateaus.The radial stress trends at the rock-grout interface paralleled pullout load curves,with sliding failure exhibiting approximately 10 MPa lower peak radial stress compared to tooth cutting failure.Anchorage length most strongly affected peak load,while grout properties predominantly governed failure mode.
文摘Objective:This integrative review aims to synthesize observational evidence on the prevalence,predictors,and psychosocial correlates of death anxiety in patients with hear t failure(HF).Methods:A comprehensive literature search was conducted using 5 major databases:Scopus,Pub Med,Science Direct,Embase,and Pro Quest.Inclusion criteria were primary research studies published in English between January 2014 and March 2025 that quantitatively assessed death anxiety among patients with HF and explored its associations with demographic,clinical,or psychosocial variables.Results:A total of 12 eligible studies were identified and systematically reviewed,revealing that death anxiety is moderate to high among most samples.Key predictors of this anxiety included older age,feelings of loneliness,low socioeconomic status,and longer duration of HF.Additionally,several studies highlighted protective factors such as spiritual orientation,religious coping,and resilience.Interventions,including cognitive-behavioral therapy(CBT)and illness perception training,showed significant reductions in death anxiety.Conclusions:Death anxiety is a prevalent and impactful concern among Patients with HF,influenced by both individual and contextual factors.Routine assessment and integration of psychosocial and spiritual care—alongside evidence-based psychological interventions—are essential to address this critical aspect of HF management.
文摘AIM:To investigate the underlying causes of surgical failure and reoperation management in patients with rhegmatogenous retinal detachment(RRD)who underwent scleral buckle surgery at our institution.METHODS:This was a single-center,retrospective,descriptive study.The clinical data of 368 patients(387 eyes)with RRD who underwent scleral buckling(SB)surgery between August 2013 and July 2023 at our institution were collected.The aim was to analyze the causes of recurrence and the rationale for selecting reoperation methods.RESULTS:Totally 368 patients(387 eyes)were included in the analysis,comprising 222 males and 146 females.The average age was 30.26±14.18 years,and the mean follow-up duration was(48.33±20.39)mo.The success rate of SB surgery was 90.2%.Recurrent retinal detachment occurred in 38 eyes.Based on surgical records,the causes of SB failure were analyzed.The recurrence causes included abnormal compression ridge position(position,height,or width)in 14 eyes(36.8%,14/38),hole omission in 11 eyes(29.0%,11/38),proliferative vitreoretinopathy(PVR)in 10 eyes(26.3%,10/38),and new holes in 3 eyes(7.9%,3/38).Among these,8 eyes(21.1%,8/38)underwent repeat SB surgery,while the remaining 30 eyes(78.9%,30/38)underwent pars plana vitrectomy(PPV).Regarding tamponade agents,silicone oil was used in 11 eyes(36.7%,11/30),C_(3)F_(8) gas in 12 eyes(40.0%,12/30),and sterile air in 7 eyes(23.3%,7/30).CONCLUSION:SB surgery demonstrates a high success rate in the treatment of RRD.However,abnormal compression ridge position,missed holes during surgery,and PVR are the primary causes of SB failure.After addressing the reasons for failure,re-SB surgery or PPV can be effective alternatives.
文摘Objective: To conduct a scoping review of kinesiophobia among primary caregivers of patients with chronic heart failure (CHF). Methods: Following a scoping review methodological framework, PubMed, Web of Science, Embase, Cochrane Library, CINAHL, CNKI, SinoMed, Wanfang, and VIP were searched from inception to 30 June 2025. Relevant studies on kinesiophobia in primary caregivers of CHF patients were identified, summarized, and analyzed. Results: A total of 24 studies were included. Caregivers generally showed insufficient exercise-related knowledge, particularly regarding appropriate exercise intensity and risk recognition. At the cognitive-affective level, caregivers exhibited a pronounced “substitutive” kinesiophobia, characterized by excessive worry about potential adverse events induced by patients’ physical activity. At the behavioral level, this was reflected in restricting patients’ activities and avoiding assisting with exercise, which in turn reduced patients’ adherence to cardiac rehabilitation. Conclusion: Kinesiophobia among primary caregivers of CHF patients arises mainly from cognitive deficits and protective psychological mechanisms. Individualized education and professional guidance are needed to enhance caregivers’ exercise management competence and thereby optimize patients’ rehabilitation outcomes.
文摘BACKGROUND Anxiety,depression,and other negative emotions are common among patients with chronic renal failure(CRF).Analyzing the factors related to negative emotions is necessary to provide targeted nursing care.AIM To explore the correlations among life satisfaction,pleasure levels,and negative emotions in patients with CRF.METHODS One hundred patients with CRF who received therapy at the First Affiliated Hospital of Jinzhou Medical University between December 2022 and February 2025 were included.The Depression,Anxiety,and Stress Scale(DASS-21),Satisfaction with Life Scale(SWLS),and Temporal Experience of Pleasure Scale(TEPS)were used to evaluate negative emotions,life satisfaction,and pleasure level,respectively.Pearson’s correlation coefficient analyzed the correlation between life satisfaction,pleasure level,and negative emotions.Linear regression analysis identified the factors affecting negative emotions.RESULTS The average DASS-21 score among patients with CRF was 51.90±2.30,with subscale scores of 17.90±1.50 for depression,18.53±1.18 for anxiety,and 15.47±2.36 for stress,all significantly higher than the domestic norm(P<0.05).The average SWLS score was 22.17±4.90.Correlation analysis revealed a negative correlation between the SWLS and total DASS-21 scores(P<0.05),but not with the individual depression,anxiety,or stress dimensions.The average TEPS score was 67.80±8.34.TEPS scores were negatively correlated with the DASS-21 score and the stress dimension(P<0.05),but not with depression or anxiety.Linear regression analysis showed that TEPS scores significantly influenced DASS-21 scores(P<0.05).CONCLUSION Patients with CRF experience high levels of negative emotions,which are negatively correlated with life satisfaction and pleasure.Furthermore,pleasure level had an impact on negative emotions.
文摘BACKGROUND Congenital hypothyroidism(CH)is a common condition in both preterm and term infants characterized by either thyroid gland absence or hypofunctionality.The clinical association of refractory lactic acidosis and heart failure has rarely been observed in cases of pediatric patients with CH pathology.Here,we explored the etiological relationship between CH,heart failure,and refractory lactic acidosis to reflect the importance of thyroid function screening in neonates with heart disease.CASE SUMMARY A 33-day-old extremely premature female infant presented with tachypnea,respiratory distress,recurrent infections,and abdominal distension postnatal.On admission to our facility,she had cardiomegaly,hepatomegaly,and lactic acidosis(revealed on blood gas analysis),with lactate progressively rising to 25 mmol/L.Chest radiographs showed pulmonary congestion,while echocardiography revealed cardiac enlargement,left ventricular wall thickening,and pericardial effusion.Initial management aimed at correcting acidosis and treating heart failure proved ineffective.After reassessment,thyroid function tests showed significantly decreased triiodothyronine,free triiodothyronine,thyroxine,and free thyroxine levels,with a significantly increased thyroidstimulating hormone level,confirming a CH diagnosis.Levothyroxine was administered,resulting in rapid correction of lactic acidosis and gradual improvement of thyroid function and systemic symptoms,culminating in full recovery and discharge.We also reviewed the relevant literature on thyroid and cardiac dysfunctions in order to explore their deeper association.CONCLUSION This case links CH-induced heart failure with refractory lactic acidosis,urging prompt thyroid screening in affected neonates to reduce mortality.
文摘Objective:Heart failure(HF)is a complex clinical syndrome that affects nearly 64 million individuals globally.Frequent hospital readmissions lead to poor health outcomes,impact quality of life(QoL),and are associated with high mortality rates.This study assessed readmissions,mortality,and QoL outcomes in patients with HF in a tertiary care hospital setting.Methods:Patients aged≥18 years with HF,who visited the tertiary care hospital in Karad,India were included in the study(November2019 to October 2021).Demographics,disease characteristics,and condition at discharge were recorded using the medical records of patients.The quantitative data included readmission rates and mortality rates.The qualitative aspects describing patients'QoL were assessed using a patient-reported 21-question QoL questionnaire.Results:A total of 98 patients,predominantly male(63.3%),with a mean age of 62.9 years were included.The majority of the patients(80.6%)required<15 days of hospitalization.The 2-year readmission rate was 24.4%,while the mortality rate was 43.9%.Self-care pattern showed that patients seemed to be taking mild to average care while taking good care was rare.The QoL data showed that 22.4% were living a good quality life,44.9% average,while 32.7% were living a low-quality life.Better education and better self-care were associated with a low rate of readmission.Conclusions:We were able to assess the incidence of readmission,mortality,and QoL in patients with HF in a tertiary care hospital setting.The study showed that HF impacts patients'physical,emotional,and psychological wellbeing.
基金supported by National Natural Science Foundation of China(51977155 and 61833008).
文摘According to the dynamic interaction process between cyber flow and power flow in grid cyber-physical systems(GCPS),attackers could gradually trigger large-scale power failures through cooperative cyber-attacks,subsequently forming cross-domain cascading failures(CDCF)that cross cyber-domain and power-domain and endanger the stable running of GCPS.To reveal the evolutionary mechanism of CDCF,an optimal attack scheme evaluation method is proposed,considering the spatiotemporal synergy of multiple attack-event-chains.First,in accordance with the spatiotemporal synergy of multiple attack-event-chains,the CDCF evolutionary mechanism is analyzed from the attackers'perspective,and a CDCF mathematical model is established.Furthermore,an attack graph model of CDCF evolution and its hazard calculation method are proposed.Then,the attackers'decision-making process for the optimal attack scheme of CDCF is deduced based on the attack graph model.Finally,both the evaluation and implementation processes of the optimal attack scheme are simulated in the GCPS experimental system based on IEEE-39 bus systems.
基金supported by the National Natural Science Foundation of China(Grant Nos.52222810 and 52178383).
文摘Dynamic disturbances with various frequencies could trigger different failure modes of deep excavations.Superimposed on this static stress are dynamic disturbances due to various dynamic vibrations,e.g.excavation blasting,blasting,tunnel boring machine(TBM)vibration,rockburst wave,earthquakes.Specifically,these dynamic sources are characterized by a wide range of wave frequencies f,resulting in differences in failure modes.A series of true-triaxial compression tests were conducted on granite to simulate the excavation-induced stress path in three-dimensional(3D)stresses.Subsequently,a dynamic disturbance with various frequencies was applied to a cuboid specimen,to reveal the behavior associated with brittle failure.The dynamic disturbance with frequencies f of 5 Hz,10 Hz,and 40 Hz generates less disturbed energy components in the granite together with higher peak strength.However,dynamic disturbances with f of 20 Hz and 30 Hz resulted in a lower peak strength;the peak strength of the rock increases sp albeit it decreases at first,then increases.This U-shaped phenomenon relates to the natural frequency of the granite under such stress conditions.Different rock lithologies consisting of diverse mineral composition,respond differently to each sensitive resonance frequency.Interestingly,the weak disturbance stress with a high frequency f and low amplitude A increases the ratio of crack damage to peak strength(scd/sp)in the granite.This leads to the inhibition of the expansion of the granite during the dynamic disturbance process.Multiple penetrating tensileeshear cracks appear in the s3-direction as the disturbance frequency f increases.
