Search Results (86)

Background: The Heart Rate Recovery Index (HRRI), derived from post-exercise heart rate recovery (HRR), reflects autonomic function and cardiovascular performance. Whether HRRI reflects early myocardial dysfunction and left atrial remodelling in heart failure with preserved ejection fraction (HFpEF) has not been previously examined. The H₂FPEF score, which integrates clinical and echocardiographic parameters, is used to assess the likelihood of HFpEF. This study investigates the relationship between HRRI, H₂FPEF score, and echocardiographic markers of longitudinal systolic function, including mitral annular plane systolic excursion (MAPSE), as well as left atrial volume index (LAVI), in patients with preserved left ventricular ejection fraction. Methods: A prospective observational study included 241 patients referred for cardiac exercise testing at the Institute of Cardiovascular Diseases Timisoara and the Clinical County Hospital of Sibiu. HRRI was calculated as the ratio of heart rate acceleration time (AT) to deceleration time (DT) during exercise testing. A comprehensive echocardiographic assessment was performed on all patients. Statistical analysis involved univariate testing and multivariable logistic regression with stepwise selection. Results: HRRI was significantly lower in HFpEF patients compared with those without heart failure (1.97 ± 0.66 vs. 2.73 ± 1.08, p < 0.01). HRRI correlated significantly with exercise performance, age, H₂FPEF score, and echocardiographic markers of diastolic and longitudinal systolic dysfunction. ROC analysis identified an HRRI cut-off value of 2.25 for HFpEF detection (AUC = 0.748), while HRRI remained significantly associated with HFpEF after adjustment for the covariates included in the model. The combined HRRI–H₂FPEF score improved diagnostic discrimination compared with the H₂FPEF score alone (AUC 0.897 vs. 0.858), achieving an overall classification accuracy of 82.2%. Conclusions: In our study, HRRI is significantly reduced in HFpEF and distinguishes patients with and without heart failure. It shows associations with echocardiographic markers of diastolic and longitudinal systolic dysfunction, exercise capacity, and H₂FPEF score. Full article

Deep coalbed methane (CBM) represents a strategic successor field for unconventional oil and gas exploration and development in China, and fluid mobility is a key parameter determining CBM recovery rates. Existing NMR-based studies on coal rock pore structure and fluid mobility suffer from three deficiencies: a lack of coal rock classification based on T₂ spectral morphology, failure to incorporate fractal characteristics into pore classification, and insufficient understanding of fluid mobilization mechanisms in different pore types during gas-driven recovery. This study investigates deep coal rocks of the Taiyuan Formation in the Linxing Block, eastern Ordos Basin, using low-field nuclear magnetic resonance (LF-NMR), saturation gas displacement experiments, and fractal theory. Deep coal rocks were classified into three types based on T₂ spectral peak morphology under saturated conditions: Type I (central main peak), Type II (left-shifted main peak), and Type III (balanced bimodal peak). A fractal-based method was established to subdivide fluid-filled pores into four types: P1-1, P1-2, P1-3, and P2. Through multiple nitrogen displacement experiments, the fluid mobilization characteristics of each pore type at different displacement stages were quantitatively characterized. A fluid mobility index was proposed to comprehensively evaluate the overall fluid mobility of coal rocks. The results indicate that Type I coal rocks exhibit the highest fluid mobility (54.83% after three displacement cycles), with P1-3 pores as the primary mobile fluid reservoir, whereas Type II and Type III coal rocks show lower mobility (27.70% and 32.89%, respectively), with P1-2 pores as the dominant contributors. Pore structure complexity exhibits a significant nonlinear evolutionary relationship with fluid mobility. The fluid mobility index demonstrates a strong positive correlation with the degree of mobile fluid, validating its effectiveness in characterizing fluid mobility in deep coal rock reservoirs. These findings provide a theoretical foundation for sweet spot identification and development optimization in deep coal gas reservoirs. Full article

Under the impact of earthquakes, substation systems may experience equipment failures, prolonged functional recovery periods, and expanded power outage consequences. This paper proposes a collaborative optimization framework for enhancing the seismic performance of substation systems and deploying repair resources, aimed at pre-earthquake planning. The system function is characterized by the outage availability of feeders weighted by load and user importance, and the user outage cost is explicitly defined as an economic consequence indicator with monetary units, rather than a dimensionless resilience index. A directed graph model is constructed to simulate the post-earthquake functional recovery process, and under given seismic hazard and vulnerability parameters, Monte Carlo sampling is used to capture the randomness of equipment condition failures and repair durations. Sensitivity analysis is employed to identify critical equipment, and the elitism-preservation and adaptive evolution non-dominated sorting genetic algorithm II (ERA-NSGA-II algorithm), which integrates heuristic initialization, adaptive evolution, and diversity maintenance mechanisms, is proposed to achieve joint optimization of repair teams and equipment reinforcement plans. A typical 220 kV substation case study demonstrates that the framework is feasible under the analyzed scenarios and exhibits better empirical search performance compared to the selected benchmark algorithm. Due to the limitations of a single topology and certain fixed input parameters, the obtained results are scenario-dependent and cannot be used to infer general applicability or global convergence. Full article

To address the challenges in risk assessment of complex emergency systems, such as difficulties in closed-loop structure modeling, insufficient quantification of dynamic evolution, and poor adaptability to multiple scenarios, this study proposes a dynamic risk assessment method that integrates the System-Theoretic Accident Model and Processes (STAMP) and the Cascading Failure Propagation Model (CFPM). The novelty of this coupling lies in a bidirectional “qualitative diagnosis → quantitative prediction” logic: STAMP’s identification of Unsafe Control Actions (UCAs) provides a theory-grounded blueprint for configuring the CFPM network topology and propagation parameters, while CFPM’s dynamic simulation translates these qualitative control flaws into computable risk evolution trajectories. The proposed framework adopts a two-layer structure of “qualitative modeling–quantitative analysis”. STAMP is used to construct a hierarchical control structure, identify Unsafe Control Actions (UCAs), and analyze the nonlinear interaction mechanisms among “human–organization–technology” factors. For typical scenarios of “fault not processed” and “online fault processing”, CFPM is employed to abstract the system into a node network, quantify the time-step propagation process of node failure probability, calculate the system residual performance index, and generate real-time risk evolution curves. A case study of the Tianjin Port ‘8·12’ explosion accident demonstrates that this method effectively captures the closed-loop interaction characteristics and dynamic risk evolution patterns of emergency systems. Quantitative results reveal a distinct contrast between the two handling scenarios: in the absence of maintenance intervention, system residual performance deteriorates exponentially and rapidly approaches a critical threshold; in contrast, effective online maintenance significantly retards risk accumulation and facilitates gradual system recovery, thereby preventing further escalation of consequences. Compared to traditional methods like Bayesian Networks, it shows stronger applicability by explicitly modeling closed-loop feedback structures and enabling discrete time-step quantification of risk accumulation, and can accurately identify control flaws and quantify risk accumulation effects, thereby providing support for optimizing emergency strategies. Future research should focus on enhancing the method’s adaptability to data uncertainty and cybersecurity threats. Full article

Background/Objectives: SPINEHealthie is a smartphone-based application enabling remote patient monitoring, care delivery and standardized collection of patient-reported outcome measures (PROMs). This registry-based analysis evaluates patient satisfaction with the platform across a large, heterogeneous spine surgery cohort. Methods: A total of 1729 thoracolumbar spine surgery cases were eligible for analysis. Among these, 881 (50.9%) completed the in-app feedback survey and constituted the primary feedback cohort. The global app experience was categorized as “Very Good” or “Poor”. Clinical outcomes, i.e., the Visual Analogue Scale (VAS) for back and leg pain and the Oswestry Disability Index (ODI) were assessed at baseline and in the postoperative period; Δ denotes the change from baseline to two weeks postoperation. Results: Among feedback responders, 800 patients (90.8%) rated their app experience as “Very Good”, while 80.8% of 639 patients with surgical outcome data reported that the surgery met their expectations. However, app experience and surgical outcome expectations were assessed using different items at different postoperative time points. Among patients whose surgery did not meet expectations, 84.6% rated their app experience as “Very Good”. Patients with a “Very Good” app-experience rating demonstrated significantly greater improvement in back pain (ΔVAS Back pain 2.94 vs. 2.13, p = 0.027), leg pain (ΔVAS Leg pain 3.16 vs. 2.14, p = 0.019) and disability (ΔODI 11.00 vs. 2.41, p < 0.001). In the primary model, older age, shorter follow-up duration and smaller ODI improvement were associated with an unfavorable app experience; only the association with age remained consistent across sensitivity analyses. Conclusions: Among feedback responders, SPINEHealthie was associated with a high proportion of favorable global app-experience ratings. Favorable app-experience ratings remained high, even among patients with unmet surgical expectations or failure to achieve the exploratory two-week ODI-improvement threshold, suggesting that perceived platform value is not solely explained by surgical outcome. Older patients and those with limited functional recovery were identified as subgroups that may benefit from targeted onboarding and engagement strategies. Full article

Typhoon-eye sensing places unmanned aerial vehicle (UAV) swarms in a setting where the wind field that carries the target signal also displaces aircraft, drains energy, weakens links, and increases failure risk. A rule that improves only routing or only motion can therefore move the swarm into another failure mode. This paper proposes a risk-driven cross-layer coordination scheme for such missions. A bounded risk index, computed from isolation, connectivity loss, and wind intensity, acts as a supervisory variable for multi-hop reachability maintenance, isolated-node recovery, and layered altitude adaptation. For evaluation, graph reachability is separated from useful data return through a degraded multi-hop aggregation model that includes distance loss, wind-dependent reliability, rain-induced packet loss, relay forwarding loss, and mothership collection capacity. The simulator combines a bounded Holland-type storm field, stochastic turbulence, nonlinear propulsion energy consumption, and wind-dependent structural failure. Against three literature-inspired baselines, two AI-inspired comparators, and six ablation variants, the method keeps a balanced profile across connectivity, isolation, wind exposure, data collection, and survival. In 30-run steady-state robustness tests under heavy-rain attenuation, the full strategy showed clear gains over routing-only and multi-agent reinforcement learning (MARL)-routing comparators in connectivity and isolation, but did not uniformly dominate topology reconstruction or the multi-agent deep deterministic policy gradient–artificial potential field (MADDPG-APF) recovery comparator. The results indicate that, in storm-dominated swarm sensing, resilience comes mainly from coordinating exposure reduction with topology stabilization, rather than from optimizing a single layer. Full article

Background/Objectives. Pulmonary arterial hypertension (PAH) is a rare but severe disease which leads to right ventricular (RV) maladaptation, failure and death. Currently approved drugs have limited impact on disease progression. A multitarget strategy consisting of adenosine A₂B receptor activation and phosphodiesterase-4 (PDE4) inhibition, combined with human mesenchymal stromal cells (hMSCs) therapy, was tested in experimental PAH. The main objective was to determine whether the combination improved pulmonary hemodynamics, vascular remodeling, and RV function, given the limited disease-modifying effects of currently approved vasodilators. Methods. Vascular reactivity was assessed in isolated rat pulmonary artery rings exposed to the dual-target compound (LASSBio-1860) alone or in the presence of either ZM-241385 or MRS-1706. PAH was induced in male Wistar rats with monocrotaline (MCT, 60 mg·kg⁻¹) and confirmed by a decrease in pulmonary artery acceleration time to ejection time ratio (PAAT/TET). Animals were randomized to receive vehicle, hMSC (single i.v. dose, 1 × 10⁵ cells), LASSBio-1860 (62 mg·kg⁻¹·day⁻¹, p.o., 14 days), or their combination. Outcomes included PAAT/TET and RV cardiac output (RV-CO) by echocardiography, RV systolic pressure (RVSP) by direct puncture, Fulton index and RV wall thickness, lung histology (perivascular cell counts and wall thickness), and RV protein expression (TGF-β, CaMKII) by Western blot. Results. LASSBio-1860 produced endothelium-independent vasorelaxation of rat pulmonary arteries, consistent with A₂B agonism and PDE4 inhibition. In MCT-induced PAH, combination of LASSBio-1860 and hMSCs resulted in recovery of PAAT/TET and RV-CO, decrease in RVSP, RV hypertrophy, vascular inflammation and remodeling by downregulation of ventricular TGF-β and CaMKII. Conclusions. Combination of LASSBio-1860 with hMSC improved RV function, attenuated pulmonary hypertension, RV and vascular remodeling, and reduced inflammatory/proliferative signaling in MCT induced-PAH, supporting a promising multitarget therapeutic strategy for PAH. Full article

Gob-side roadways driven along the floor while retaining top coal in thick soft coal seams are prone to instability under strong mining-induced dynamic loading. To clarify the instability mechanism and develop an effective control method, the 1609 return airway of Jiulishan Mine was investigated using field survey, borehole imaging, FLAC3D numerical simulation, industrial testing, and field monitoring. The results show that, under the combined effects of large mining height, insufficient filling of the gob by the caved immediate roof, weak retained top coal, and low coal strength, shear failure planes tend to develop within the narrow coal pillar and extend from the gob-side roof toward the floor. Once the dominant shear plane cuts through the pillar, the overall bearing structure is destroyed, leading to shear slip, asymmetric rib deformation, roof subsidence toward the coal-pillar side, and rib–roof coupled instability. Based on a multi-index evaluation of pillar load-bearing capacity, plastic zone development, stress concentration, roadway deformation, and coal recovery, a 3 m coal pillar was determined as the rational width. A coordinated “narrow coal pillar + cross-rib anchorage” scheme was proposed, and field verification confirmed its effectiveness in controlling roof separation, roadway surface displacement, and internal surrounding-rock damage. Full article

Chronic thromboembolic pulmonary hypertension (CTEPH) is a progressive disease that occurs due to fibrotic remodeling of the pulmonary vessels. This leads to increased pressure overload onto the right ventricle, resulting in complications such as heart failure. Pulmonary endarterectomy (PEA) remains the gold standard of treatment for CTEPH, yet many patients experience life-threatening perioperative complications, including refractory right ventricular failure, reperfusion pulmonary edema, and endobronchial hemorrhage. Extracorporeal membrane oxygenation (ECMO) has been used as a form of mechanical circulatory support to aid recovery in patients with perioperative complications in the context of CTEPH. This review identifies preoperative risk factors, including pulmonary vascular resistance, high body mass index, and elevated neutrophil-to-lymphocyte ratios. It also identifies differences in ECMO configuration, with veno-arterial ECMO preferred for hemodynamic instability and veno-venous ECMO for respiratory failure. Finally, we posit that, based on contemporary literature, the implementation of early ECMO in decompensated patients may be associated with reduced hospital mortality, and in those who survive beget excellent mid-term survival. Full article

Concrete and cementitious composites exhibit brittle failure under shear stress, limiting their resilience in seismic and high-load applications; this study investigates whether crimped NiTi shape memory alloy (SMA) fibers can enhance pure shear strength and ductility of mortar specimens, with particular focus on the effect of thermal activation. Z-shaped mortar specimens were prepared with SMA fiber volume fractions of 0%, 1.0%, and 1.25%, tested under both non-heated and heated conditions using a Universal Testing Machine, with deformation monitored via LVDTs and Digital Image Correlation. SMA fiber reinforcement increased peak shear strength by 13% and 14.5% for 1.0% and 1.25% fiber volumes, respectively, under ambient conditions, reaching up to 22% enhancement after thermal activation due to recovery-stress-induced prestressing; the 1.0% fiber volume achieved the highest ductility index of 4.05 compared to 1.03 for plain mortar, while SMA fibers had negligible influence on initial shear modulus but substantially improved post-cracking response and crack bridging. These findings demonstrate that crimped SMA fibers effectively improve shear resilience of cementitious composites, with 1.0% fiber content offering the optimal balance between strength and ductility, though activation protocols require careful calibration to minimize thermal degradation of the matrix. Full article

Autonomous driving in underground mines faces significant challenges due to Global Navigation Satellite System (GNSS) denial and harsh environmental conditions. Mainstream multi-sensor fusion and Simultaneous Localization and Mapping (SLAM) schemes have achieved substantial progress in underground navigation, but their deployment in feature-sparse tunnels may still face challenges related to computational burden and perception robustness. This study explores an infrastructure-assisted navigation architecture that transforms the roadway into a structured luminous guidance channel by deploying programmable Light Emitting Diode (LED) strips along the tunnel roof. The proposed system simplifies complex three-dimensional pose estimation into a two-dimensional visual servoing task targeting optical signals. Central to this approach is a robust data fusion strategy that utilizes a topology matching algorithm to map noisy Ultra-Wide-band (UWB) coordinates onto a discrete LED index space, thereby providing a reliable global positioning reference. Furthermore, a hierarchical fault-tolerant controller based on a Finite State Machine (FSM) is designed to facilitate seamless degradation to a UWB-assisted ultrasonic wall-following mode in the event of visual degradation, supporting fault-tolerant operation under controlled laboratory conditions. Experimental results in a laboratory simulation environment demonstrate that the system achieves millimeter-level static initialization accuracy, a dynamic tracking Root Mean Square Error of approximately 4 cm, and a 100% autonomous recovery rate from visual failures in straight tunnels. These results demonstrate the feasibility of the proposed infrastructure-assisted route under controlled laboratory conditions and suggest its potential as an engineering reference for structured underground transport scenarios with acceptable infrastructure modification. Full article

Exercise adaptation depends on overload that is resolved by recovery, yet the same biology becomes maladaptive when immune, endocrine, metabolic, and muscle-centered stress signals fail to normalize. Exercise-induced maladaptation represents a systems-level failure of biological resolution, with direct relevance to disease-like dysregulation. Functional overreaching, non-functional overreaching, and overtraining syndrome remain difficult to diagnose because no single biomarker provides adequate specificity, temporal stability, or clinical portability. This narrative review synthesizes human and mechanistic evidence across proteomics, transcriptomics, metabolomics, endocrine profiling, extracellular vesicles, and mitochondrial quality-control biology to define the molecular architecture most relevant to athlete monitoring. Across these layers, the most coherent signatures cluster in immune-acute-phase activation, redox-buffering strain, endocrine drift, altered substrate availability, excitation–contraction dysfunction, integrated stress-response signaling, and defects in autophagy–mitophagy and lysosomal remodeling. Three translational elements emerge from this synthesis: a systems-convergence model of recovery failure, a staged biomarker deployment hierarchy, and a provisional recovery failure index. The practical priority is therefore not a solitary marker, but serial phenotype-anchored multimarker panels that connect circulating signals with muscle-centered biology and support decision-making before prolonged recovery failure becomes entrenched. Full article

Background: Influenza is a common cause of hospitalization in young children, particularly infants. While most infections are self-limited, severe and life-threatening complications may occur. Diffuse alveolar hemorrhage (DAH) is a rare pulmonary manifestation of influenza, predominantly reported in adults, and is exceedingly uncommon in immunocompetent infants. Case Presentation: We report the case of an 8-month-old previously healthy female infant who presented with influenza A infection and rapidly progressed to acute respiratory failure and shock despite antiviral therapy. Bleeding was noted from the nasal cavity prior to clinical deterioration, and during emergent endotracheal intubation, blood was observed flooding the bronchial tree, consistent with massive pulmonary hemorrhage. Flexible bronchoscopy showed diffusely erythematous and friable airway mucosa without an identifiable focal bleeding source, and early bronchoalveolar lavage was nondiagnostic. Nasopharyngeal testing confirmed influenza A (H3). Laboratory findings revealed severe systemic inflammation, leukopenia with neutropenia, and anemia with normal coagulation parameters. Chest imaging demonstrated bilateral pulmonary infiltrates. After exclusion of autoimmune, coagulation, immunodeficiency, and alternative infectious causes, a diagnosis of diffuse alveolar hemorrhage secondary to influenza A infection was established. The patient was successfully managed with supportive care, antiviral therapy, tranexamic acid, and empiric antibiotics, without corticosteroid treatment, and made a full recovery. Conclusions: This case emphasizes that influenza-associated DAH in infants may occur without overt hemoptysis and may not demonstrate classical BAL findings early in the disease course. Clinicians should maintain a high index of suspicion in rapidly deteriorating infants with influenza and diffuse pulmonary infiltrates. The optimal role of corticosteroids remains uncertain and should be individualized. Full article

Background: Coronary artery bypass grafting is the optimal revascularization strategy for patients with complex multivessel coronary artery disease. However, saphenous vein grafts are associated with high failure rates and donor site morbidity. Off-the-shelf tissue-engineered vascular grafts offer a potential solution for patients lacking suitable autologous vessels. Here, we report the first successful clinical implant of an acellular Tissue-Engineered Vessel (TEV) for coronary artery bypass grafting in Europe. Methods: A 73-year-old male with two-vessel disease and no suitable autologous vein underwent on-pump coronary artery bypass grafting using the left internal mammary artery to the left anterior descending artery and a 4 mm TEV to the right coronary artery. Results: Implant procedure followed standard surgical techniques, sutures and duration. The conduit handling was comparable to native vessels. Intraoperative flow measurements demonstrated excellent graft performance (TEV: 110 mL/min, Pulsatility Index 1.0). Postoperative recovery was uneventful. One-month computed tomography coronary angiography confirmed graft patency. Discussion: This case demonstrates the feasibility of using a bioengineered conduit for coronary revascularization in patients without suitable autologous grafts. If these findings are confirmed in larger trials, bioengineered vessels could expand surgical revascularization to patients without suitable autologous conduits and fundamentally alter conduit selection strategy in CABG. Conclusions: This first-in-Europe clinical implant demonstrates that an off-the-shelf acellular tissue-engineered vessel can meet the procedural, hemodynamics, and patency requirements of coronary artery bypass. These proof-of-concept results support progression to prospective multi-center evaluation. Full article

Oxidative aging drives asphalt pavement degradation, causing critical structural failures. This study evaluated hazelnut (HS) and walnut shell (WS) powders (0–3% w/w; 10–12 μm) as sustainable antioxidants, from valued residues, to mitigate thermo-oxidative aging in CA-24 binders. After evaluating the antioxidant potential (ORAC; Oxygen radical absorbance capacity, and TPC; Total phenolic content), modified binders underwent RTFO (Rolling thin film oven) and PAV (Pressure aging vessel) aging, evaluated by Fraass fragility, Relative Aging Index (RAI), dynamic shear rheometry (G*/sin δ), and Multiple Stress Creep Recovery (MSCR). WS exhibited significantly higher antioxidant capacity (6000 μmol TE g DW⁻¹) and TPC than HS. The 3% treatments demonstrated optimal antioxidant efficacy, reducing long-term RAI by 14% and improving low-temperature flexibility by 3.8 °C (Fraass point −12.3 °C). However, MSCR revealed initial plasticizing effects decreasing elastic recovery (70%) and increasing non-recoverable compliance (Jnr) compromising unaged rutting resistance. Principal component analysis confirmed progressive diversification of aging-induced properties, evidencing complex multivariate trajectories. Ultimately, while nutshell derived phenolic modifiers provide effective concentration-dependent antioxidant protection, practical application requires optimization through targeted phenolic extraction, particle engineering, or elastomeric co-modification. Balancing aging resistance with high temperature stability remains essential for advancing these sustainable biomodification strategies in road infrastructure. Full article