Search Results (101)

Objectives: Conventionally, the gold standard for aortic valve disease has been surgical aortic valve replacement (SAVR). Advances in transcatheter aortic valve replacement (TAVR) have since produced marked improvements in both outcomes and procedural volume. We sought to characterize this evolution by comparing the earliest and most recent 100 procedures of each modality at a single high-volume institution. Methods: We retrospectively compared four cohorts of 100 consecutive isolated procedures: 100 TAVRs from 2012 (the earliest period of complete and verifiable registry capture) and 100 first-time SAVRs from a contemporaneous period (2011), each versus the 100 most recent procedures of the same modality (TAVR 2024; SAVR 2024–2025). The SAVR cohorts were limited to first-time, isolated replacement; the TAVR cohorts to native-valve procedures. The primary endpoint was the 30-day composite of death or stroke. Secondary endpoints included new permanent pacemaker implantation, paravalvular leak, vascular access route, anesthetic technique, and length of stay. Results: For TAVR, the 30-day composite of death or stroke fell from 10% to 1% (p = 0.010), with fewer in-hospital deaths (6% to 0%; p = 0.029) and less new dialysis (4% to 0%; p = 0.059). A paravalvular leak of at least mild severity fell from 27% to 3% (p < 0.001), with none as moderate or greater in either era. New pacemaker implantation decreased from 15% to 6% (p = 0.056). Within the same comparison, general anesthesia decreased from 100% to 23%, non-transfemoral access from 29% to 2%, median ICU stay from 43 to 0 h, and hospital stay from 6 to 1 day (all p < 0.001). SAVR outcomes remained similar (composite 2% to 0%, p = 0.497; pacemaker 1% to 0%; and paravalvular leak 0% to 4%), while prolonged ventilation (11% to 1%; p = 0.007) and hospital stay (8 to 5 days; p < 0.001) improved. The SAVR population became younger (74 to 64 years; p < 0.001), and isolated first-time surgery was markedly less frequent, requiring 18.9 versus 5.7 months to accrue 100 consecutive cases. Conclusions: In this two-era institutional comparison, recent-era TAVR outcomes were markedly better, while SAVR outcomes remained excellent in both eras within a recent population that was younger and in whom eligible isolated first-time surgery was less frequent. Because the eras differed substantially in patient risk profile, these unadjusted within-modality comparisons describe a real-world redistribution of aortic stenosis care between two increasingly complementary treatments rather than isolating the effect of any single procedural or technological factor. Full article

Harmful algal blooms (HABs) pose a growing ecotoxicological threat to bivalve molluscs and their consumers. Current regulatory frameworks governing shellfish safety, however, rely on acute human toxicity limits that poorly capture the biological complexity of bivalve–HAB interactions. This narrative review synthesises the published literature on the effects of HAB toxins on bivalves. It assesses their physiology, immune function, and stress resilience, comparing these findings against the limits set by the EU, the United States (US) and Australia/New Zealand. Sublethal responses from immunosuppression and impaired reproduction to oxidative stress and altered valve activity frequently occur at concentrations below current action levels. Environmental variables such as marine heatwaves, salinity fluctuations and hypoxia shift toxin bioaccumulation and depuration in ways that existing safety limits fail to capture. The main toxin groups, their mechanisms of action and species-specific accumulation and elimination kinetics are examined alongside current monitoring and management strategies. The review concludes that bridging the gap between shellfish-safety regulation and bivalve ecotoxicology requires integrating physiological stress indicators into regulatory frameworks. Such integration must draw on advanced monitoring technologies and adaptive management capable of responding to a rapidly changing ocean. Full article

Efficient monitoring of pork freshness is essential to minimize spoilage-related losses in the meat industry. To address the limitations of existing detection technologies, namely high cost, poor timeliness and high environmental sensitivity, this study developed a novel electronic nose system integrating a hybrid sensor array with dynamic gas path control. By combining metal oxide semiconductor (MOS) and electrochemical sensors (e.g., MQ137, MQ136), the system exhibits high sensitivity to the key volatile organic compounds (VOCs) released during pork spoilage, achieving a detection accuracy of over 90% in identifying spoilage stages. Combined with a dual-mode gas circuit design (solenoid valve switching time: 0.85 s), the reliability of the system was further demonstrated. This technology offers an economical and efficient real-time monitoring solution for slaughterhouses and cold chain logistics, providing a new low-cost scientific approach for pork freshness assessment. Full article

Intelligent completion technologies, including Inflow Control Valves (ICVs), have become increasingly important for remotely managing zonal production in complex well architectures. However, quantifying flow rates and phase fractions in such systems remains challenging due to space constraints and the harsh downhole environment, which limit the deployment of conventional sensors. Distributed Acoustic Sensing (DAS) provides a promising solution by converting standard fiber-optic cables into dense arrays of acoustic sensors. While DAS has been successfully applied in applications such as integrity monitoring and leak detection, its use for direct two-phase flow characterization within intelligent completions remains largely unexplored. In this study, we present a DAS-based methodology to monitor and analyze oil–water two-phase flow in horizontal experiments that mimic field conditions. Acoustic data collected from DAS are transformed into time–frequency spectrograms using Short-Time Fourier Transform (STFT) to extract dynamic spectral features. These features are then correlated with pressure drop across the ICV and flow rate, revealing distinct frequency band behaviors associated with fluid changes. To quantify flow characteristics, a power-law model is trained using spectral features to predict flow rate and phase fractions. The results demonstrate strong predictive capability for pressure drop and flow rate under controlled laboratory conditions, highlighting the potential of DAS for multiphase flow diagnostics in field applications with intelligent completions, while water cut prediction remains challenging due to the complex and non-unique relationship between flow conditions and DAS response and is left for future work. This research not only provides new insights into the acoustic response of oil–water flows but also introduces a data-driven framework for leveraging DAS in real-time flow monitoring and control within ICV-equipped completions. Full article

Energy efficiency and sustainability are core issues in the modern design and management of industrial machinery and plants. These concerns are reflected and reinforced by the Sustainable Development Goal 9 of the United Nations (SDG9), “Industry, innovation and infrastructure”, which enshrines efficiency and optimized energy use as key features of sustainable production systems. As the engineering of industrial machinery reorients itself towards energy sustainability, attention is naturally shifting to actuators, since these components unavoidably waste part of the considerable amount of energy they absorb to execute their functions. Hydraulic actuation systems, while uniquely suited to heavy-duty applications, are particularly affected by poor energy conversion efficiency, in part due to their intrinsic properties but also because of outdated yet still common industrial practices. Consequently, for this actuation technology, there are wide margins for improvement in terms of energy waste reduction and increased environmental sustainability. This paper, therefore, investigates new applications for a management and control method conceived by the authors to drastically and systematically reduce the energy consumption of hydraulic actuators. The method is easily retrofittable to existing plants, being based on the unconventional and non-invasive deployment of a continuous-control electrohydraulic valve (CCEV) to control the supply pressure, whose required value is estimated according to the instantaneous load demands. Through the simulation of several industrial processes characterized by process parameters of varying orders of magnitude, this paper demonstrates that this innovative use of a CCEV for supply pressure regulation is an effective and widely applicable solution for energy savings and CO₂ footprint reduction in production systems that rely on hydraulic servo axes. Full article

Cardiac computed tomography (CT) has long evolved as a highly accurate screening tool for coronary artery disease. New technologies such as multi-detector rows and artifact reduction by a new motion correction algorithm have made it possible to evaluate coronary artery stenosis with higher diagnostic accuracy and lower radiation exposure. In addition to the anatomical evaluation of coronary arteries, the introduction of fluid dynamic analysis enables the measurement of coronary fractional flow reserve (FFR) for each stenotic lesion, which can only be achieved through invasive catheter evaluation. Myocardial ischemia can now also be detected using myocardial stress perfusion CT imaging. In addition, with the advent of dual-energy imaging or new image reconstruction technology, the addition of late contrast phase imaging enables myocardial late enhancement and left ventricular (LV) extracellular volume (ECV) analysis, which was previously possible only with cardiac magnetic resonance imaging (MRI). It has also been reported that LV ECV may be useful in predicting prognosis in cases with cardiomyopathies. In addition, retrospective imaging of the entire heart in a single cardiac cycle is now possible with lower radiation exposure, enabling not only morphological evaluation of the heart and valves but also myocardial strain analysis, which has conventionally been evaluated mainly by echocardiography and is expected to be applied in clinical practice in the future. Cardiac CT, which overcomes the weaknesses of other modalities while demonstrating greater usefulness through the latest technological development, is expected to expand its field of application to the entire heart analysis. The purpose of this review is to provide an overview of the technological development of cardiac CT, which has seen remarkable development in recent years, along with its clinical utility, with the aim of enabling clinicians to fully utilize it in daily practice. Full article

The high incidence of cardiovascular disease and the early failure of bioprosthetic valves due to calcification have driven the development of anti-calcification technologies. As a new storage technology, drying treatment is expected to delay the calcification process by reducing glutaraldehyde residues. However, the effects of drying treatment on the mechanical properties and valve functions of bovine pericardial materials are still unclear. The objective of this study is to evaluate the influence of drying and rehydration treatments on the mechanical integrity and geometric properties of bovine pericardium and the hemodynamic performance of bioprosthetic valves made with these tissues. Cross-linked bovine pericardial samples (n = 15) were divided into three groups—wet (control group progressed with normal glutaraldehyde), dehydrated (ethanol–glycerol dehydration), and rehydration (saline immersion) groups—and the geometric stability and nonlinear mechanical behaviors of the materials were analyzed via thickness measurements and uniaxial and biaxial tensile tests. Quantitative results showed that thickness remained stable across groups (wet: 0.356 ± 0.052 mm; dry: 0.361 ± 0.053 mm; rehydrated: 0.361 ± 0.053 mm, p > 0.05). Elastic modulus values were preserved (wet: 12.5 ± 1.8 MPa; dry: 13.1 ± 2.0 MPa; rehydrated: 12.7 ± 1.9 MPa, p > 0.05), and anisotropy ratio showed no significant changes (1.53 ± 0.06 vs. 1.57 ± 0.07, p > 0.05). The hemodynamic performance of bioprosthetic valves made with these materials was evaluated in vitro using a pulsating flow simulation. Hemodynamic parameters demonstrated excellent preservation: effective orifice area (wet: 2.625 ± 0.11 cm²; rehydrated: 2.585 ± 0.12 cm², Δ = 1.5%, p = 0.32) and regurgitation fraction (wet: 39.35 ± 2.9%; rehydrated: 42.78 ± 3.2%, p = 0.15) showed no statistically significant differences. The geometric properties of the material were not significantly changed by the drying treatment, and the material maintained its nonlinear viscoelastic characteristics and anisotropy. The rehydrated bioprosthetic valves did not differ significantly from those in the wet group in terms of the effective orifice area, regurgitation fraction, and transvalvular pressure difference, and the hemodynamic performance remained stable. Full article

Background: Randomized controlled trials (RCTs) are the foundation of evidence-based medicine. However, the rapid pace of technological innovation in cardiovascular surgery and interventional cardiology challenges the traditional RCT framework. Observational studies may hold renewed value in fields where device evolution outpaces the time required to validate clinical outcomes. Methods: This analysis evaluates 270 randomized and non-randomized studies in transcatheter aortic valve implantation (TAVI), one of the most rapidly evolving areas in cardiovascular medicine. The investigation follows two lines: first, mapping the timeline of major RCTs against the introduction of new prosthetic models; second, comparing the prevalence, duration, and role of randomized (R) versus non-randomized (NR) studies. Results: The timeline reveals a persistent misalignment between innovation and validation. New prosthetic models frequently enter the market while RCTs for prior generations are still ongoing. For example, the Sapien 3 valve was approved, while trials on Sapien XT were still enrolling. Similarly, newer Evolut and Acurate models were introduced during ongoing studies of earlier versions, often prompting new studies before existing ones concluded. This leapfrogging effect fragments the evidence base and delays definitive comparisons. In parallel, randomized trials have increased in number and tend to be shorter in duration, reflecting a maturing field. However, non-randomized studies remain crucial for early testing and post-market surveillance. Conclusions: In a field with rapid technological evolution a sort of Zeno’s paradox occurs: long-term validation cannot keep pace with fast innovation, resetting the evidence base with each new model. To overcome this paradox, a paradigm shift in evidence generation is desirable. Future strategies must augment adaptive trial designs, leverage real-world data and use higher-level, advanced analyses to incorporate subjective variables and phenotypic diversity, to reduce confounding factors and speed up data access. Higher-level, integrative evidence analytics could help Achilles walk alongside the tortoise. Full article

As a zero-carbon energy carrier, hydrogen is playing an increasingly vital role in the decarbonization of maritime transportation. The hydrogen pressure reducing valve (PRV) is a core component of ship-borne hydrogen storage systems, directly influencing the safety, efficiency, and reliability of hydrogen-powered vessels. However, the marine environment—characterized by persistent vibrations, salt spray corrosion, and temperature fluctuations—poses significant challenges to PRV performance, including material degradation, flow instability, and reduced operational lifespan. This review comprehensively summarizes and analyzes recent advances in the study of high-pressure hydrogen PRVs for marine applications, with a focus on transient flow dynamics, turbulence and compressible flow characteristics, multi-stage throttling strategies, and valve core geometric optimization. Through a systematic review of theoretical modeling, numerical simulations, and experimental studies, we identify key bottlenecks such as multi-physics coupling effects under extreme conditions and the lack of marine-adapted validation frameworks. Finally, we conducted a preliminary discussion on future research directions, covering aspects such as the construction of coupled multi-physics field models, the development of marine environment simulation experimental platforms, the research on new materials resistant to vibration and corrosion, and the establishment of a standardized testing system. This review aims to provide fundamental references and technical development ideas for the research and development of high-performance marine hydrogen pressure reducing valves, with the expectation of facilitating the safe and efficient application and promotion of hydrogen-powered shipping technology worldwide. Full article

The convergence of Industrial Internet of Things (IIoT) and digital twin technology offers new paradigms for process automation and control. This paper presents an integrated IIoT and digital twin framework for intelligent control of a gas–liquid separation unit with interacting flow, pressure, and differential pressure loops. A comprehensive dynamic model of the three-loop separator process is developed, linearized, and validated. Classical stability analyses using the Routh–Hurwitz criterion and Nyquist plots are employed to ensure stability of the control system. Decentralized multi-loop proportional–integral–derivative (PID) controllers are designed and optimized using the Integral Absolute Error (IAE) performance index. A digital twin of the separator is implemented to run in parallel with the physical process, synchronized via a Kalman filter to real-time sensor data for state estimation and anomaly detection. The digital twin also incorporates structured singular value ($\mu$) analysis to assess robust stability under model uncertainties. The system architecture is realized with low-cost hardware (Arduino Mega 2560, MicroMotion Coriolis flowmeter, pneumatic control valves, DAC104S085 digital-to-analog converter, and ENC28J60 Ethernet module) and software tools (Proteus VSM 8.4 for simulation, VB.Net 2022 version based human–machine interface, and ML.Net 2022 version for predictive analytics). Experimental results demonstrate improved control performance with reduced overshoot and faster settling times, confirming the effectiveness of the IIoT–digital twin integration in handling loop interactions and disturbances. The discussion includes a comparative analysis with conventional control and outlines how advanced strategies such as model predictive control (MPC) can further augment the proposed approach. This work provides a practical pathway for applying IIoT and digital twins to industrial process control, with implications for enhanced autonomy, reliability, and efficiency in oil and gas operations. Full article

To address the demands for wide-range and high-precision current measurement, this paper proposes a novel current sensor design that integrates spin sensing technology, magnetic shunt effect, and a multi-sensor data fusion algorithm. The spin valve sensors accurately detect the magnetic field generated by the signal current, while the soft magnetic shunt structure attenuates the magnetic field to a level suitable for the spin valve sensors. Consequently, the detection current range can be extended by 6.8 times. Using four spin valve sensors and data fusion with an averaging algorithm, the system can calibrate the errors caused by the displacement or tilt of the current-carrying wire. Experimental results demonstrate that the current sensor achieves a sensitivity of 61.6 mV/V/A, an excellent linearity of 0.55%, and robust measurement performance, as well as strong anti-interference capability. Our study offers a novel solution for high-precision, wide-range current measurement in applications such as those in new energy vehicle electronics and precision electric energy metering. Full article

Aortic valve diseases affect a significant percentage of the population, and with the extension of survival expectancy, they are expected to increase furthermore. Surgical treatment of aortic valve diseases mainly includes valve replacement and, rarely, its repair. The technology of both surgical and transcatheter valves is evolving, and new prosthetic valves with improved characteristics are available, e.g., longer lifespan, faster implantation, better hemodynamic performance with better effective orifice area, suitable for small aortic annuli, etc. Minimally invasive surgical techniques are constantly evolving and spreading. New access sites are used for transcatheter valve implantation. The Heart Team determines the most appropriate intervention for each patient based on their anatomical and clinical profiles, aiming to optimize long-term outcomes. Full article

Rail transit as a high-energy consumption field urgently requires the adoption of clean energy innovations to reduce energy consumption and accelerate the transition to new energy applications. As an energy-saving fluid machinery, the ejector exhibits significant application potential and academic value within this field. This paper reviewed the recent advances, technical challenges, research hotspots, and future development directions of ejector applications in rail transit, aiming to address gaps in existing reviews. (1) In waste heat recovery, exhaust heat is utilized for propulsion in vehicle ejector refrigeration air conditioning systems, resulting in energy consumption being reduced by 12~17%. (2) In vehicle pneumatic pressure reduction systems, the throttle valve is replaced with an ejector, leading to an output power increase of more than 13% and providing support for zero-emission new energy vehicle applications. (3) In hydrogen supply systems, hydrogen recirculation efficiency exceeding 68.5% is achieved in fuel cells using multi-nozzle ejector technology. (4) Ejector-based active flow control enables precise ± 20 N dynamic pantograph lift adjustment at 300 km/h. However, current research still faces challenges including the tendency toward subcritical mode in fixed geometry ejectors under variable operating conditions, scarcity of application data for global warming potential refrigerants, insufficient stability of hydrogen recycling under wide power output ranges, and thermodynamic irreversibility causing turbulence loss. To address these issues, future efforts should focus on developing dynamic intelligent control technology based on machine learning, designing adjustable nozzles and other structural innovations, optimizing multi-system efficiency through hybrid architectures, and investigating global warming potential refrigerants. These strategies will facilitate the evolution of ejector technology toward greater intelligence and efficiency, thereby supporting the green transformation and energy conservation objectives of rail transit. Full article

The introduction of transcatheter aortic valve replacement (TAVR) has revolutionized the management of aortic stenosis (AS), leading to significant improvements in patient outcomes. Over time, advancements in device technology have further optimized safety and performance of TAVR. However, as the pool of low-risk patients undergoing TAVR expands, many of whom present with concomitant coronary artery disease (CAD), new challenges have emerged. A large proportion of TAVR candidates suffer from CAD, and the clinical implications of this comorbidity remain a subject of debate. Research on the relationship between AS and CAD has yielded conflicting results, but severe CAD is generally linked to worse outcomes in AS patients. The coexistence of AS and CAD complicates diagnosis and management, requiring a comprehensive understanding of both invasive and non-invasive diagnostic techniques, along with careful revascularization strategies. This review explores the prevalence, clinical impact, and diagnostic challenges of CAD in TAVR patients, highlighting emerging methods for its assessment. Key aspects of treatment, including the timing of coronary revascularization, coronary re-access after TAVR in different settings, as well as practical tips and tricks for coronary cannulation, are also discussed. The complexity of managing AS and CAD is further intensified by the need for individualized approaches, particularly in hybrid procedures and subsequent TAVR interventions. Ongoing research and technological innovations offer promising solutions for refining the management of CAD in AS patients undergoing TAVR, with an emphasis on improving prognostic accuracy, optimizing revascularization strategies, and enhancing post-procedural care. Full article

Background/Objectives: Valve-in-valve (ViV) transcatheter aortic valve implantation (TAVI) is a key approach for treating degenerated surgical bioprosthetic valves. The ACURATE neo2 valve, with its advanced sealing technology and optimized coronary access, represents a promising solution for the challenges of ViV TAVI. This study evaluates the procedural and 30-day and 1-year follow-up outcomes of the ACURATE neo2 valve in ViV TAVI. Methods: This single-center, single-operator prospective study included patients with symptomatic bioprosthetic valve dysfunction, classified in New York Heart Association (NYHA) class III or IV, who underwent ViV TAVI with ACURATE neo2 at our center between July 2022 and February 2024. Outcomes were assessed using VARC-3 criteria. Results: Fifty-five patients (51% females, median (IQR) age 76 (8) years) were included. The technical success rate was 98.2%. No patients experienced in-hospital mortality, stroke, MI, bleeding, vascular complications, renal failure, or new pacemaker implantation. Three patients (5.5%) underwent elective chimney stenting for coronary protection. The postprocedural mean aortic gradient was 6.7 ± 1 mmHg, with a mean aortic valve area (AVA) of 2.0 ± 0.1 cm². Over a median follow-up period of 1.2 years, no deaths (0%) were observed, heart failure hospitalization rate was 3.6%, and NYHA class improved to ≤II in 100% of patients. Conclusions: ACURATE neo2 demonstrated excellent technical success, sustained hemodynamic performance, and significant clinical improvement in ViV TAVI. The absence of major adverse events reinforces its safety, efficacy, and durability as a treatment for degenerated surgical bioprostheses. Full article