Search Results (6,656)

Posterior urethral valves (PUV) cause congenital urinary tract obstruction and often lead to chronic kidney disease (CKD) despite treatment; however, DNA methylation remains underexplored in PUV. This cross-sectional study aimed to compare peripheral-blood global DNA methylation, measured as 5-methylcytosine content (5-mC%), between boys with PUV and age-matched male controls, and to assess its association with kidney function, CKD stage, and kidney scarring. The study included 45 boys with PUV and 45 age-matched boys as controls. Peripheral-blood global 5-mC% was quantified using an ELISA-based assay. Glomerular filtration rate and kidney scarring were assessed by nuclear scintigraphy, and PUV patients were categorized according to CKD stage and scarring status. Statistical comparisons were performed using the Kruskal–Wallis test followed by Dunn’s test, with exploratory trend analysis used to evaluate the association between global 5-mC% and CKD severity. Global 5-mC content was significantly higher in PUV patients than in controls (median 5-mC%: 0.4336 vs. 0.3732, p < 0.001). Within the PUV cohort, global 5-mC% increased with CKD severity (p < 0.05) and showed a logarithmic association with CKD stage (R² = 0.8012). Patients with kidney scarring also had significantly higher global 5-mC% than controls (p < 0.001), although differences across individual CKD stages and scarring subgroups were not statistically significant. These findings suggest altered systemic global 5-mC content in boys with PUV and support larger, longitudinal studies incorporating locus-specific methylation profiling. Full article

The advent of transcatheter aortic valve implantation (TAVI) has redefined the treatment of aortic stenosis over the last two decades, evolving from a therapy reserved for patients that were deemed to be of prohibitive surgical risk to the standard of care for a large group of patients presenting with symptomatic disease. With improvements in technology, operator and institutional experience and longer-term outcome data, recent guidelines have supported the broadening of indications to low-risk and asymptomatic patients in addition to other pathologies including the management of failed surgical bioprosthetic valves and aortic regurgitation. The rapid developments in the field have resulted in a rapid expansion of TAVI. The focus has moved from the technical aspects of the procedure itself that are now well established to the lifetime management of patients with aortic stenosis, particularly younger patients with regard to valve durability, planning for a further intervention after TAVI and associated considerations including future coronary access. Beyond aortic stenosis, TAVI technology is also increasingly being utilized for the management of failed surgical bioprostheses, bicuspid valve disease, aortic incompetence and mitral/tricuspid disease and these represent future areas of focus in the field. Full article

This article presents the synthesis, implementation, and experimental study of a PI-based adaptive actor–critic displacement volume controller of an axial-piston pump intended for open-loop circuit hydraulic drive systems. The proposed control structure combines a conventional PI actor with an adaptive critic that estimates the infinite-horizon cost through Bellman-error minimization. By using the tracking error and its integral as actor inputs, the controller avoids the need for an accurate plant model while retaining a compact and practically implementable structure. The adaptive laws are derived using gradient-based learning, and a Lyapunov-based analysis establishes closed-loop stability for sufficiently small adaptation gains. The controller is implemented in a fixed-step Simulink^® environment and deployed on a rapid prototyping platform with real-time communication to an industrial microcontroller and proportional valve amplifier. The experimental results obtained under four fixed loading conditions and dynamic load variations demonstrate a stable operation, bounded critic behavior, and a near-zero Bellman error during learning. Comparative tests against a classical PI controller, a Lyapunov-based model reference adaptive controller, and a generic actor–critic scheme show that the proposed PI-based actor–critic achieves the lowest performance index and the shortest settling times in most cases. Full article

Mechanical circulatory support (MCS) has transformed the management of advanced heart failure; however, device-related morbidity remains substantially driven by adverse interactions occurring at the blood–material and tissue–device interfaces. Despite progressive miniaturization and the evolution from first-generation pulsatile systems to contemporary continuous-flow devices, thrombotic, hemorrhagic, infectious, and inflammatory complications continue to limit long-term outcomes. This review examines the mechanistic contribution of material properties, surface architecture, and hemodynamic conditions to the pathogenesis of major MCS-associated complications, with particular emphasis on thrombogenicity, biomaterial-induced inflammatory activation, driveline and cannulation-associated infections, hemocompatibility disturbances, and device-related structural failure. The interplay between protein adsorption, platelet activation, complement cascade dysregulation, disturbed shear profiles, and biofilm formation is analyzed as a central determinant of adverse clinical events. Special attention is given to pediatric MCS, in which the continued reliance on extracorporeal pulsatile systems, unique anatomical constraints, and narrow therapeutic margins intensify susceptibility to both thromboembolic and infectious sequelae. Furthermore, the review addresses how material and surface modifications, and emerging biomimetic and anti-thrombogenic coatings may influence complication mitigation. By integrating clinical, engineering, and biomaterials perspectives, this work highlights that many complications traditionally regarded as secondary clinical phenomena are fundamentally rooted in device–material interactions and flow-mediated biological responses. Improved understanding of these mechanisms is essential for optimizing device design, enhancing hemocompatibility, and reducing complication burden in both adult and pediatric MCS populations. Full article

Mitral valve regurgitation is the second most common valvular heart disease in Europe, and an estimated 10% of individuals older than 75 years have severe mitral regurgitation. Mitral valve repair is the preferred strategy to treat mitral regurgitation and is associated with better outcomes than mitral valve replacement. Despite the proven efficacy of surgical repair, available data in functional aetiologies reported a non-negligible rate of echocardiographically detected severe mitral regurgitation within ten years of the index procedure, in some cases resulting in redo interventions. Data on the optimal management of patients with failed mitral repair remain limited. The aim of this review is to present the available approaches for treating failed mitral valve repair and to describe criteria for selecting the most appropriate strategy on the basis of the underlying mechanism of repair failure, with respect to possible surgical re-repair and novel transcatheter edge-to-edge repair techniques in the presence of favourable mitral valve anatomies. Full article

Background and Clinical Significance: Carcinoid heart disease (CHD) is an uncommon valvular manifestation of neuroendocrine tumours, usually affecting right-sided cardiac valves. Left-sided involvement is rare and is generally associated with bronchopulmonary carcinoid, right-to-left shunting, or markedly elevated circulating vasoactive substances. Therapeutic decision-making is particularly challenging in advanced disease when severe tricuspid regurgitation occurs in patients at prohibitive surgical risk. Case Presentation: We report the case of a 61-year-old male patient with progressive dyspnoea, abdominal distension, lower-limb oedema, facial flushing, and 15 kg of unintentional weight loss. Transthoracic and transoesophageal echocardiography demonstrated torrential tricuspid regurgitation caused by thickened, retracted, and immobile leaflets, with additional mitral and aortic valve involvement, raising strong suspicion of CHD. An agitated-saline contrast study demonstrated delayed right-to-left shunting without patent foramen ovale, suggesting an extracardiac, likely intrapulmonary, shunt. Somatostatin receptor PET/CT identified a pancreatic lesion with metastatic disease, and bone marrow biopsy confirmed neuroendocrine tumour infiltration. Owing to prohibitive surgical risk, as reflected by a Tricuspid Regurgitation Impact Score (TRI-SCORE) with an estimated in-hospital mortality of 65%, unfavourable tricuspid anatomy for repair, and refractory venous congestion, heterotopic bicaval valve implantation was performed (TricValve system -P&F). Discussion: This case highlights the role of echocardiography in recognising the characteristic phenotype of CHD, detecting occult right-to-left shunting, and supporting selection of a palliative transcatheter intervention. It also illustrates the value of a multimodality diagnostic strategy integrating echocardiography, functional oncological imaging, and histopathology in tumour-related cardiac disease. Conclusions: In selected inoperable patients with advanced carcinoid-related tricuspid regurgitation, heterotopic bicaval valve implantation may represent a feasible strategy for reducing venous congestion and improving functional status. Full article

Background: Patients with prolonged mechanical ventilation (PMV) frequently require tracheostomy due to failure to wean, yet the pathway from ventilator dependence to successful decannulation remains complex and poorly standardised. Comprehensive respiratory rehabilitation is recognised as a core strategy for improving decannulation outcomes, but no unified, evidence-based guidelines currently exist for this population. This review addresses that gap by synthesising current evidence on respiratory rehabilitation and decannulation strategies for tracheostomized PMV patients. Methods: A narrative review was conducted through a systematic search of PubMed/MEDLINE covering publications indexed from May 2019 to February 2026, supplemented by targeted searches of Embase and the Cochrane Library. The search combined free-text keywords and Medical Subject Headings (MeSH) terms across eight search string combinations. Following title and abstract screening of 830 deduplicated records, 51 studies met eligibility criteria and were included in the final narrative synthesis. Results: Six core rehabilitation intervention domains were identified: respiratory muscle training, physical rehabilitation and nutritional optimisation, sedation and delirium management, speaking valve use, airway complication management, and ventilator mode optimisation. High-intensity inspiratory muscle training at no less than 50% of maximal inspiratory pressure is currently supported by the strongest available evidence among the interventions reviewed, although this threshold derives primarily from general ICU populations and has not been specifically validated in heterogeneous tracheostomized PMV cohorts. Decannulation readiness assessment may benefit from evaluating five core domains—neurological readiness, secretion management capacity (suctioning ≤ 4 times/24 h), cough efficacy (peak cough flow > 160 L/min), safe swallowing confirmed by instrumental assessment, and upper airway patency confirmed by fiberoptic bronchoscopy—using a structured multidisciplinary framework. Conclusions: Successful decannulation in tracheostomized PMV patients requires integration of evidence-based rehabilitation interventions, structured multidisciplinary assessment, and a patient-centred outcome framework that extends beyond physiological endpoints to encompass voice restoration, psychological well-being, and social reintegration. Significant evidence gaps remain—particularly for expiratory muscle training, population-specific decannulation protocols, and adapted rehabilitation models for resource-limited settings—representing priority areas for future research. Full article

Background and Objectives: Transcatheter aortic valve implantation (TAVI) is the standard therapy for patients with severe aortic stenosis at intermediate or high surgical risk. Mitral annular calcification (MAC) is frequently observed in this population and has been linked to adverse cardiovascular outcomes. This study evaluated the association between MAC and TAVI-related complications and mortality, and identified predictors of all-cause mortality and permanent pacemaker implantation (PPI) following TAVI. Materials and Methods: Patients undergoing self-expanding TAVI between January 2010 and June 2020 were retrospectively analyzed. Outcomes included TAVI-related complications, in-hospital and long-term mortality, and predictors of all-cause mortality and PPI. Results: A total of 245 patients (98 men [40%], mean age 76.3 ± 8.3 years) were included. Mean left ventricular ejection fraction was 54.8 ± 11.4%, and aortic valve area was 0.74 ± 0.14 cm². MAC was present in 148 patients (60.4%). Pericardial effusion (26.4% vs. 12.4%, p = 0.013) and acute kidney injury (21.6% vs. 7.2%, p = 0.005) were significantly more frequent in patients with MAC. PPI was required in 42 patients (17.8%). In-hospital mortality occurred in 14 patients (5.7%), and all-cause mortality was observed in 89 patients (36.3%) during a median follow-up of 23.1 months (IQR, 11.6–44.3). MAC extension into the left ventricular outflow tract was the only independent predictor of PPI (OR: 3.32, p = 0.002). Independent predictors of all-cause mortality included use of renin–angiotensin–aldosterone system blockers (HR: 0.54, p = 0.012), hemoglobin level (HR: 0.79, p = 0.006), severe MAC (HR: 1.94, p = 0.024), and post-TAVI atrial fibrillation (HR: 2.39, p = 0.002). Conclusions: MAC is common in TAVI patients and is associated with increased procedural complications, including higher rates of pericardial effusion and acute kidney injury. Greater MAC severity independently predicts higher all-cause mortality. In addition, MAC extension into the left ventricular outflow tract is an independent predictor of PPI following self-expanding TAVI, emphasizing the importance of comprehensive pre-procedural imaging. Full article

Background: New-onset atrial fibrillation (NOAF) is a common complication after transcatheter aortic valve implantation (TAVI) and is associated with unfavorable clinical outcomes. Sodium–glucose cotransporter-2 (SGLT2) inhibitors may have antiarrhythmic effects, but their association with NOAF after TAVI remains uncertain. This study evaluated the relationship between SGLT2 inhibitor use and NOAF following TAVI. Methods: This retrospective observational study included 573 consecutive patients who underwent transfemoral TAVI between January 2020 and December 2025. Patients with prior atrial fibrillation or atrial flutter were excluded. NOAF was defined as any atrial fibrillation episode lasting ≥30 s during index hospitalization. A doubly robust inverse probability weighted logistic regression model was applied to reduce baseline imbalances and assess the association between SGLT2 inhibitor use and NOAF. Results: Overall, 169 patients received SGLT2 inhibitors, while 404 patients constituted the control group. NOAF occurred less frequently in the SGLT2 inhibitor group than in controls (11% vs. 19%, p = 0.041). In adjusted analysis, SGLT2 inhibitor use was independently associated with lower odds of NOAF (adjusted OR: 0.171, 95% CI: 0.076–0.381, p < 0.001). Older age and diabetes mellitus were associated with increased NOAF risk, whereas higher baseline left ventricular ejection fraction was associated with lower risk. Subgroup analysis indicated a possible interaction by diabetes status (P-interaction = 0.040), although this exploratory finding should be interpreted cautiously. Conclusions: SGLT2 inhibitor use was independently associated with lower odds of NOAF after TAVI. These findings should be interpreted as observational and hypothesis-generating and require confirmation in prospective randomized studies. Full article

Background: Patients undergoing open-heart surgery (OHS) are at risk of postoperative morbidity and mortality. Physical performance has been increasingly recognized as an important factor influencing postoperative outcomes. Therefore, the study aimed to investigate the associations and predictive value of physical performance on postoperative complications and duration of hospital stay. Methods: A prospective cohort study was conducted in 116 patients who were admitted to OHS. Preoperative assessment of physical performance, i.e., Short Physical Performance Battery (SPPB), Five Times Sit to Stand Test (5STS), gait speed (5 m walk test: 5MWT), Timed Up and Go (TUG), and handgrip strength. Duration of hospital stay and incidence of post-operative complications were recorded. Differences between participants with and without postoperative complications were analyzed using independent samples t-tests for continuous variables and chi-square tests for categorical variables. The associations between physical performance and postoperative outcomes were assessed using Spearman’s rank correlation coefficient. Hierarchical regression analysis was conducted to determine the predictive contribution of physical performance. Results: A total of 116 participants were submitted for OHS in two medical school hospitals; however, 108 individuals completed the pre-operative physical performance. The most common procedures were coronary artery bypass grafting and valve surgery. Fifty-one participants (47.22%) experienced postoperative complications, including five deaths, corresponding to 4.63% mortality. For the length of hospital stay analysis, five participants who died postoperatively were excluded, resulting in a final sample of 103 participants. Physical performance was significantly associated with the length of hospital stay (p < 0.05). Hierarchical regression analysis showed that the final prediction model explained 13.4% of the variance in length of hospital stay, with SPPB independently contributing an additional 6.0% to the model, followed by 5STS, 5MWT, handgrip strength, and TUG, which accounted for an additional 5.1%, 4.6%, 4.4%, and 3.7%, respectively. Conclusions: Preoperative physical performance was associated with length of hospital stay. While each measure explained a relatively small proportion of the variance in hospital stay, these assessments offer a simple, non-invasive, and clinically feasible approach to evaluating functional reserve before surgery. These findings highlight the importance of incorporating functional assessment into perioperative care to support risk stratification and guide rehabilitation strategies. Full article

As the core actuation component of intelligent precision spraying systems, the variable-rate nozzle is essential for achieving on-demand agricultural spraying; improving the use efficiency of water, fertilizers and pesticides; and reducing environmental pollution. This paper systematically reviews the development of agricultural variable-rate nozzles, from early mechanical profiling structures to modern intelligent control technologies based on Pulse Width Modulation (PWM). First, the existing variable-rate nozzles are classified into three major categories: electromagnetic-integrated type, centrifugal type, and variable-diameter type. A comparative analysis is conducted from three dimensions of working principle, performance characteristics and application scenarios, to delineate the respective advantages and limitations of each nozzle category. Second, the paper examines key technological advances in three areas: high-frequency solenoid valves, PWM control, and pressure and flow stabilization. It identifies the nonlinear response of solenoid valves, flow distortion under low duty cycles, and water hammer pressure fluctuation induced by high-speed switching as the three core technical bottlenecks at the current stage. Subsequently, the latest achievements and typical methodologies of variable-rate nozzles in structural design, simulation and experimental analysis are systematically reviewed, and their application performance in scenarios including field crops, orchards, protected agriculture and beyond are summarized. Finally, the remaining open issues in this field are put forward. It is suggested that future research should focus on key breakthroughs in the development of corrosion and wear-resistant high-frequency solenoid valves, the formation mechanism and suppression methods of pressure fluctuation, as well as adaptive algorithms based on machine learning or Model Predictive Control (MPC), to promote the leapfrog development of agricultural variable-rate nozzle technology from single variable control to multi-factor coupling optimization. All references cited in this paper are from articles published after the year 2000. Among them, the literature published in the last decade accounts for 86.6%, and literature published in the last five years accounts for 58.9%. Full article

With the expansion of ammonia energy applications, long-distance liquid ammonia pipelines are expected to support large-scale cross-regional ammonia transport. In the liquid ammonia pipeline commissioning process, gaseous ammonia purging involves ammonia–nitrogen mixing and possible liquefaction, while liquid ammonia injection may induce flashing and severe local cooling, all of which can affect commissioning safety. To characterize these thermodynamic phenomena, a transient gas–liquid two-phase flow model was established and validated using OLGA 2022.1.0 software for simulating the long-distance liquid ammonia pipeline commissioning. The model adopts the cross-sectionally averaged one-dimensional approach. A volume-corrected Soave–Redlich–Kwong (SRK) equation of state for ammonia was adapted, validated, and used to generate OLGA-compatible thermodynamic property tables. The results show that, during gaseous ammonia purging, a higher flowrate shortens the displacement time by accelerating nitrogen removal, and this effect is more pronounced at higher ambient temperatures due to enhanced molecular diffusion. Along the pipeline, pressure gradually decreases from frictional resistance, with a steeper drop near the outlet caused by gas acceleration, and temperature gradually approaches ambient through heat exchange with the pipe wall and surrounding soil. A high gaseous ammonia flowrate can cause partial liquefaction, regasification, and temperature fluctuations. During liquid ammonia injection, local condensation and slight liquid accumulation occur before the liquid front arrives, and the low-temperature region moves with the liquid front. The liquid ammonia mass flowrate has the strongest influence on the injection process, as it reduces the completion time but increases the outlet temperature, outlet pressure, and the low-temperature risk downstream of the valve. Therefore, it should be controlled within an appropriate range to balance efficiency and low-temperature safety risks. This work provides a rapid and efficient prediction model for key thermo-hydraulic parameters during liquid ammonia pipeline commissioning, and the overall analyses offer insights for on-site process design and safety control. 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

Trichosporon is a type of non-candida yeast-like fungus. At one time, it was commonly reported in immunocompromised patients, but after the introduction of fluconazole as prophylaxis and for the treatment of fungal infections, there was a decrease in the incidence of the disease. With the introduction of echinocandins as the first line of treatment for fungal infections, and the intrinsic resistance of Trichosporon to the drug, there has been a small but increased reported incidence of the disease. Trichosporon usually causes skin infections, but invasive disease can occur in vulnerable patients. Endocarditis due to Trichosporon has been reported rarely, and usually occurs in prosthetic valves. In this paper, we report a patient with dialysis-dependent chronic kidney disease who presented with fever and was found to have native aortic valve endocarditis. In view of the large vegetation, he underwent early aortic valve replacement. Both the blood and tissue cultures grew Trichosporon spp. Post-operatively, he developed fungal septic shock, deteriorated, and died. Invasive Trichosporon disease has been associated with high rates of mortality ranging from 30 to 90%. There is limited literature on endocarditis resulting from Trichosporon. Specific treatment recommendations are unavailable, and a combination of surgery and prolonged antifungal medication will generally be required. Full article

The continuous suture technique is not routinely used in surgical aortic valve replacement (SAVR), and data regarding its clinical outcomes remain limited. This retrospective observational study evaluated early and mid-term outcomes after continuous suture SAVR in a real-world cohort. Eighty-eight consecutive patients who underwent SAVR using a continuous suture technique between November 2015 and July 2024 were included. Both isolated and concomitant procedures were analyzed. The operative technique consisted of three 2-0 polypropylene sutures, one placed along each aortic cusp. Clinical outcomes, postoperative complications, and survival were assessed. The mean age was 62.22 ± 15.22 years, and 71.6% of patients were male. Bioprosthetic valves were implanted in 61.4% of cases, and the mean prosthesis size was 25.02 ± 0.93 mm. Concomitant procedures were performed in 86.4% of patients. There were no in-hospital deaths. New-onset atrial fibrillation occurred in 26.1% of patients, and permanent pacemaker implantation was required in 3.4%. The median cross-clamp time was 41.50 min. During a mean follow-up of 18.38 months, one- and three-year overall survival was 92.9%. No prosthetic valve dysfunction related to thrombus, pannus formation, or clinically significant paravalvular leak was observed. Continuous suture SAVR appears feasible and safe, with acceptable early and mid-term outcomes, although the retrospective, non-comparative design requires cautious interpretation. Full article