Search Results (2,074)

This work assesses the frictional wear of lubricated transmission chains, correlating the coefficient of friction, root mean square (RMS) acoustic emissions, and vibrations induced by friction, incorporating Industrial Internet of Things (IIoT) components. The work is divided into two phases: understanding the frictional interactions between the steel pins of commercial transmission chain and high chrome steel plate (mimicking the interaction between the pin and roller of the chain) using a reciprocating tribometer (20 N, 2.5 Hz, 15.1 stroke length) in the presence of three commercial lubricant aerosols (Grade A, Grade B, and Grade C) and analyzing the frictional wear, sound, and vibration signals generated during the tribo-tests. In the second phase, the findings from the laboratory scale are validated using a commercial transmission chain under aerosol lubrication. Results indicated that the coefficient of friction in the case of dry conditions was 41% higher than that of Grade A aerosol and Grade C aerosol and 28% higher than that of Grade B aerosol. However, the average wear scar diameter on the pin with Grade C (0.401 ± 0.129 mm) was higher than that on the pins with Grades A (0.209 ± 0.159 mm) and B (0.204 ± 0.165 mm). Grade A and Grade B aerosols exhibited similar frictional conditions, while the wear-scar diameter in Grade C was the highest among Grades A and B but still less than in dry conditions. Analyzing the sound and vibrations generated during the friction test, it can be seen that the dry condition produced approximately 60% more sound level than the Grade A and Grade B conditions, and 41% more sound than the Grade C condition. The laboratory results were validated with a real-time transmission chain using an in-house chain wear test rig. Results from the chain wear test rig indicated that the elongation of the chain with Grade B is the least amongst the aerosols and dry conditions. The surface characterizations of the steel pins also indicated intense deep grooves and surface damage in dry conditions, with Grade A exhibiting the most severe damage, followed by Grade C, and the least severe in Grade B. Additionally, dark patches were visually observed on the rollers of the lubricated commercial chains, indicating stressed areas on the rollers, while polished wear was observed on the rollers under dry conditions. Full article

Chronic insomnia is a prevalent and disabling sleep disorder with growing evidence linking it to cardiovascular and cerebrovascular morbidity. Stroke, a leading cause of mortality and a long-term disability worldwide, may be influenced by sleep disturbances through multiple physiological mechanisms. While traditional risk factors such as hypertension, atrial fibrillation, diabetes, obesity, smoking, and sedentary lifestyle remain dominant drivers of stroke burden, accumulating evidence suggests that sleep disturbances, particularly chronic insomnia, may act as both independent risk factors for incident stroke and as outcomes of cerebrovascular injury. Chronic insomnia, affecting approximately 10% of the global population, is characterized by persistent difficulties with sleep initiation, maintenance, or quality, accompanied by daytime dysfunction. Beyond its impact on quality of life and mental health, insomnia has been linked to cardiometabolic dysregulation, inflammation, and vascular dysfunction. Importantly, sleep disturbances after stroke can impair recovery and functional outcomes, underscoring a bidirectional relationship between stroke and sleep. Several recent reviews have examined the connection between insomnia and stroke. Our review differs by focusing specifically on (1) the stroke-specific epidemiological evidence for chronic insomnia as a risk factor, (2) the bidirectional interplay between insomnia and post-stroke sleep disturbances, and (3) the role of emerging technologies in monitoring and prognosis. By addressing these gaps, we aim to refine the current understanding and highlight priorities for future research and clinical translation. Full article

Ischemic stroke is a leading cause of disability worldwide, often triggered by atherothrombotic or embolic events. A growing body of evidence highlights the role of neuroinflammation as a central mechanism in post-stroke damage, influenced by modifiable systemic risk factors. Emerging evidence suggests that oxidative stress mediates the impact of several modifiable risk factors by activating redox-sensitive pathways (such as NF-κB), impairing nitric oxide bioavailability, and promoting matrix metalloproteinase activity that disrupts vascular integrity and contributes to ischemic injury. In this context, our meta-analysis examined major modifiable risk factors for ischemic stroke, with a particular focus on their shared ability to promote oxidative stress and neuroinflammatory cascades. By emphasizing these redox-dependent mechanisms, our work supports the biological plausibility of exploring antioxidant strategies as complementary approaches to mitigate stroke risk. Hypertension, diabetes, dyslipidemia, smoking, atrial fibrillation, and transient ischemic attacks all contribute to oxidative damage through mechanisms such as endothelial dysfunction, vascular inflammation, and excessive free radical exposure. We searched PubMed, PubMed Central, Web of Science, and Scopus for observational studies published within the last five years, identifying 23 studies (691,524 participants) meeting eligibility criteria. Using a random-effects model, we found significant associations between stroke risk and hypertension (OR = 1.58, 95% CI: 1.28–1.94), smoking (OR = 1.61, 95% CI: 1.13–2.28), type 2 diabetes (OR = 1.53, 95% CI: 1.29–1.81), atrial fibrillation (OR = 1.88, 95% CI: 1.28–2.75), and prior transient ischemic attack (OR = 1.62, 95% CI: 1.24–2.11). These risk factors are known to contribute to systemic inflammation, potentially exacerbating neuroinflammatory cascades post-stroke. Despite limitations such as heterogeneity and low certainty of evidence, our findings reinforce the relevance of targeting inflammation-driven risk factors in stroke prevention strategies and future research. Full article

Background: Deep vein thrombosis (DVT) is a serious thromboinflammatory complication of acute ischemic stroke (AIS). The true incidence, mechanistic risk factors, and optimal prophylactic strategies remain uncertain, particularly in the era of reperfusion therapy. Methods: This systematic review and meta-analysis (IRIS-DVT) searched PubMed, Embase, Cochrane, Scopus, and Web of Science for studies reporting DVT incidence, risk factors, or prophylaxis in AIS (2004–2025). Random-effects models were used to generate pooled prevalence and effect estimates, and the certainty of evidence was graded using the GRADE framework. Results: Forty-two studies (n = 6,051,729 patients) were included. The pooled prevalence of DVT was 7% (95% CI, 6–9%), approximately seventy-fold higher than in the general population, with wide heterogeneity influenced by screening timing and diagnostic modality. Pathophysiological risk factors included higher stroke severity (NIHSS; SMD 0.41; 95% CI, 0.38–0.43), older age (SMD 0.32; 95% CI, 0.18–0.46), elevated D-dimer (SMD 0.55; 95% CI, 0.38–0.72), female sex (OR 1.33; 95% CI, 1.19–1.50), and malignancy (OR 2.69; 95% CI, 1.56–5.22), supported by moderate-certainty evidence. Respiratory infection and admission hyperglycemia showed weaker, low-certainty associations. Traditional vascular risk factors (hypertension, diabetes, atrial fibrillation, dyslipidemia) were not significantly related to DVT risk. Evidence for prophylaxis with low-molecular-weight heparin, direct oral anticoagulants, or intermittent pneumatic compression was limited and graded very low certainty. Conclusions: DVT complicates approximately one in fourteen AIS cases, reflecting a distinct thromboinflammatory process driven more by acute neurological severity, systemic hypercoagulability, and malignancy than by conventional vascular risk factors. Early systematic screening (≤72 h) and consistent use of mechanical prophylaxis are warranted. Dedicated AIS-specific mechanistic and interventional trials are urgently needed to refine prevention strategies and improve post-stroke outcomes. Full article

Background: Coronary artery disease (CAD) is common among liver transplantation (LT) candidates, yet whether pre-transplant percutaneous coronary intervention (PCI) improves post-LT outcomes remains uncertain. Methods: We conducted a single-center, Institutional Review Board-approved cohort study of adults undergoing LT from 2005 to 2025. Asymptomatic candidates with significant stenosis on invasive angiography were included; prior coronary artery bypass grafting was excluded. The primary endpoint was major adverse cardiovascular events (MACE: myocardial infarction [MI], stroke/transient ischemic attack, new systolic dysfunction, post-LT coronary revascularization, or all-cause death). Results: Among 111 patients (median age 65 years; 84% male), 66 (59%) underwent PCI and 45 (41%) were managed medically. Over a median 32 months of follow-up, 61 patients (55%) experienced MACE. Composite MACE did not differ between PCI and non-PCI groups (52% vs. 60%, p = 0.40; log-rank p = 0.59). Fine–Gray modeling showed no association of PCI with MACE; independent predictors were prior MI (HR 1.81, 95% CI 1.01–3.24) and pre-transplant dialysis (HR 2.13, 95% CI 1.07–4.24). Major bleeding occurred in 7%. Matched and era-stratified analyses were concordant. Conclusions: In asymptomatic LT candidates with angiographically severe CAD, pre-LT PCI was not associated with a lower incidence of post-LT MACE. Full article

In recent years, advances in medicine have been evident thanks to technological growth and interdisciplinary research, which has allowed the integration of knowledge, for example, of engineering into medical fields. This integration has generated developments and new methods that can be applied in alternative situations, highlighting, for example, aspects related to post-stroke therapies, Multiple Sclerosis (MS), or Spinal Cord Injury (SCI) treatments. One of the methods that has stood out and is gaining more acceptance every day is Brain–Computer Interfaces (BCIs), through the acquisition and processing of brain electrical activity, researchers, doctors, and scientists manage to transform this activity into control signals. In turn, there are several methods for operating a BCI, this work will focus on motor imagery (MI)-based BCI and three types of acquisition paradigms (traditional arrow, picture, and video), seeking to improve the accuracy in the classification of motor imagination tasks for naive subjects, which correspond to a MI task for both the left and the right hand. A pipeline and methodology were implemented using the CAR+CSP algorithm to extract the features and simple standard and widely used models such as LDA and SVM for classification. The methodology was tested with post-stroke (PS) subject data with BCI experience, obtaining 96.25% accuracy for the best performance, and with the novel paradigm proposed for the naive subjects, 97.5% was obtained. Several statistical tests were carried out in order to find differences between paradigms within the collected data. In conclusion, it was found that the classification accuracy could be improved by using different strategies in the acquisition stage. Full article

Malignant cerebral infarction (MCI) is rare but often fatal. Early identification helps guide monitoring and decompressive surgery. This study evaluated whether serum biomarkers add predictive value beyond clinical and imaging data in severe stroke patients with anterior circulation large vessel occlusion (LVO). In this prospective study, 73 acute severe LVO stroke patients underwent whole-brain CT perfusion (CTP) with rCBV-based core measurement at admission and follow-up MRI at 24 ± 12 h for infarct and edema volume assessment. Serum biomarkers (s100b, NSE, VEGF, ICAM1) were sampled a median of 20.5 h after baseline imaging. Logistic regression models predicted MCI using baseline variables (NIHSS, ASPECTS, rCBV < 30%), adding treatment data (rtPA, mTICI, NIHSS posttreatment), and adding serum biomarkers. Performance was assessed by AUC, accuracy, F1, and cross-validated R². MCI occurred in 18/73 (24%) patients. Baseline models showed an AUC of 0.72; adding treatment improved the AUC to 0.88. Biomarkers slightly increased the AUC (0.90) but did not improve F1. Higher s100b was associated with more severe injury but did not enhance the prediction of MCI. Models with baseline imaging and treatment best explained infarct (R² ≈ 0.27) and edema (R² ≈ 0.58). In conclusion, admission severity, CTP, and early treatment response are the main predictors of MCI and aid early risk stratification of patients. Despite their pathophysiologic relevance, serum biomarkers do not add substantial predictive value. Full article

Coccidioidal meningitis (CM) is a rare but life-threatening complication of disseminated coccidioidomycosis, occurring in ~16% of cases, particularly among children in endemic regions such as the southwestern US and northern Mexico. Without timely diagnosis and antifungal therapy, pediatric CM is almost universally fatal within the first year. Hydrocephalus develops in up to 50% of cases. In 2000, Galgiani et al. established fluconazole as first-line therapy for CM. Subsequent guidelines refined management but did not specifically address pediatric patients (>1 month–≤19 years). No studies in the fluconazole era have systematically evaluated risk factors for complications in this population. We therefore conducted a systematic review and proportional synthesis of pediatric CM cases, focusing on CNS complications and outcomes. PubMed/MEDLINE, Embase (Ovid), and Web of Science were systematically searched (2000–2025). PROSPERO registration ID (1130290). Inclusion criteria encompassed epidemiological studies, case series, and case reports that described at least one pediatric case of CM or CNS involvement, confirmed by diagnostic methods. Cases in adults, neonates (<1 month), congenital infections, teratogenicity studies, reviews, or incomplete reports were excluded. Only cases with complete individual data (n = 48) were included. Methodological rigor was ensured using JBI Critical Appraisal Tools. Of 1089 studies, 31 met the inclusion criteria, representing 3874 pediatric cases. CM/CNS involvement was confirmed in 165 cases (4.25%; 95% CI: 3.6–4.9%), with hydrocephalus in 62 (37.5%). Among 48 case reports with complete data, fluconazole was first-line therapy in 65%. Serum CF titers ≥ 1:16 were associated with hydrocephalus plus stroke (p = 0.027) and independently predicted adverse outcomes (relapse/death; OR = 4.5, p = 0.037), whereas lifelong azole therapy was associated with improved outcomes (overall survival mean, 82 vs. 32 months; p = 0.002). Pediatric CM remains highly lethal, with hydrocephalus a frequent and severe complication. High serum CF titers (≥1:16) predict poor outcomes, emphasizing the urgent need for standardized, pediatric-specific diagnosis and management guidelines. Full article

Background/Objectives: The relationship between thrombus imaging features and the natural evolution of stroke remains poorly defined. We aimed to investigate the associations between thrombus characteristics on CT and perfusion parameters, as well as subsequent infarct progression, in untreated patients experiencing an anterior circulation acute ischemic stroke (AIS). Methods: This retrospective analysis enrolled 81 untreated patients with AIS who underwent baseline non-contrast CT (NCCT), CT angiography (CTA), CT perfusion (CTP), and a follow-up NCCT. We evaluated the thrombus length, location, and clot burden score (CBS). CTP parameters included the ischemic core, hypoperfused tissue, and penumbra volumes. Infarct growth was the difference between the final infarct volume on a follow-up NCCT and the initial core volume on CTP. Univariate and multivariate regression models were performed. Results: Higher CBS values and shorter thrombi are associated with a reduced ischemic core (coefficients B of −3.9 and 0.88, p < 0.01), diminished hypoperfused tissue (coefficients B of −12.2 and 2.87, p < 0.001), and smaller penumbra volume (coefficients B of −7.9 and 1.99, p < 0.001). More distal occlusions were associated with smaller perfusion deficits. Importantly, a higher CBS and more distal thrombus location were significantly associated with a smaller final infarct volume and infarct growth volume. Conclusions: In untreated AIS patients, a lower thrombus burden (higher CBS, shorter length, distal location) is associated with more favorable baseline perfusion parameters and predicts a slower, less severe natural evolution of AIS. These findings underscore the prognostic value of baseline thrombus characteristics in determining the intrinsic course of a stroke. Full article

Background/Objectives: Stroke is the second leading cause of death worldwide. There is an unmet need to manage stroke pathophysiology, including L-glutamate (L-Glu)-mediated neurotoxicity. The acai berry (Euterpe sp.) contains phytochemicals with potentially nutraceutical content. The aim of this study was to assess the ability of acai berry extracts to counter L-Glu neurotoxicity using human differentiated TE671 cells. Methods: The cytotoxicity of L-Glu and acai berry extracts was quantified using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays. Mitochondrial function was examined by a quantitation of cellular ATP levels, the maintenance of the mitochondrial membrane potential (MMP), and the production of reactive oxygen species (ROS). Whole-cell patch-clamp recordings monitored the activation of N-methyl-D-aspartate receptors (NMDARs). Candidate phytochemicals from acai berry extracts were modeled in silico for NMDAR binding. Results: L-Glu significantly reduced cell viability, ATP levels, the MMP, and increased cellular ROS. Generally, acai berry extracts alone were not cytotoxic, although high concentrations were detrimental to ATP production, maintenance of the MMP, and elevated ROS levels. Whole-cell patch-clamp recordings revealed that the combined addition of 300 µM L-Glu and 10 µM glycine activated currents in differentiated TE671 cells, consistent with triggering NMDAR activity. Acai berry extracts ameliorated the L-Glu-induced cytotoxicity, mitochondrial dysfunction, elevated ROS levels, and limited the NMDAR-mediated excitotoxicity (p < 0.001–0.0001). Several virtual ligands from acai berry extracts exhibited high-affinity NMDAR binding (arginine, 2,5-dihydroxybenzoic acid, threonine, protocatechuic acid, and histidine) as possible candidate receptor antagonists. Conclusions: Acai berry phytochemicals could be exploited to reduce the L-Glu-induced neurotoxicity often observed in stroke and other neurodegenerative diseases. Full article

Objective: The insertion of venous catheters into supra-aortic vessels is a standard procedure in the treatment of a large number of diseases. Incorrect placement of venous catheters into and accidental perforation of arterial vessels is a rare but serious complication that can lead to severe bleeding, dissections, and strokes. Materials and Methods: We present a case of iatrogenic malposition of a Broviac catheter into the right vertebral artery and its successful treatment through stenting of the perforation site using a Walrus balloon catheter to achieve a secure treatment position and eventually cover the perforation site. Additionally, we conducted a systematic literature review on endovascular rescue procedures in inadvertent injuries of the supra-aortic arteries related to venous catheter placement. Results: A balloon guide catheter was used to achieve a secure treatment position for the deployment of a stent graft covering the perforation site, ensuring no significant arterial hemorrhage occurred during the removal of the incorrectly placed Broviac catheter. The review of the literature on endovascular rescue procedures for supra-aortic arterial vessel damage caused by venous catheter placement revealed that endovascular treatment has been successful in all reported cases of catheter-related supra-aortic arterial injury. Primary stent graft placement without additional actions was the most common treatment approach. Conclusions: In the treatment of iatrogenic injuries to the supra-aortic vessels, endovascular treatment strategies represent a safe, reliable, and generally recognized option and thus are used much more frequently than surgical procedures. Key point: In rare cases of accidental malposition of venous catheters into supra-aortic arterial vessels, endovascular insertion of a stent graft covering the perforation site using a balloon guide catheter can be a safe treatment option. Full article

Background: Incarcerated patients with neurological complaints present substantial diagnostic and care-delivery challenges in emergency departments (EDs). We delineate the clinical spectrum, severity, and outcomes among incarcerated patients managed in an ED with an embedded neuro-emergency expert model. Methods: A retrospective observational study of adult ED visits for neurological symptoms was conducted from September 2018 to June 2025 at a government-designated regional emergency center serving multiple correctional facilities. Incarceration was confirmed in the electronic medical record. Extracted variables included demographics, chief complaint, comorbidities, triage and acuity scale, Glasgow Coma Scale (GCS), neuroimaging, ED diagnoses, and outcomes (hospital admission, ICU care, ED/in-hospital mortality). Results: Sixty-five patients were included (median age 57.0 years [IQR 47.0–64.5]; 95% male). Chief complaints were altered mental status (36.9%), hemiparesis (21.5%), and seizures (13.8%). On arrival, 40.0% had GCS ≤ 12, including 23.1% with severe impairment (GCS 3–8). Non-contrast head CT was obtained in 95.4% and diffusion-weighted MRI in 38.5%. Frequent diagnoses were psychiatric/functional neurological disorder (16.9%), metabolic encephalopathy (15.4%), and acute ischemic stroke (12.3%). Serious conditions (stroke, hypoxic brain injury, central nervous system infection, status epilepticus, and neuroleptic malignant syndrome) were diagnosed in 41.5%. Hospital admission occurred in 63.1% (ICU care in 47.7%); in-hospital mortality was 10.8%. Conclusions: ED visits by incarcerated individuals with neurological complaints were often linked to serious diagnoses, ICU use, and mortality, challenging assumptions of exaggeration. Over two in five had stroke, hypoxic brain injury, central nervous system infection, or status epilepticus. The findings support rapid, systematic, bias-aware evaluation with early neurological involvement, clear imaging triggers, safety protocol, and expedited transfers from correctional facilities. Full article

In the pursuit of zero-emission mobility, hydrogen represents a promising fuel for internal combustion engines. However, its low volumetric energy density poses challenges, especially for high-performance applications where compactness and lightweight design are crucial. This study investigates the feasibility of an innovative hydrogen-fueled two-stroke opposed-piston (2S-OP) engine, targeting a specific power of 130 kW/L and an indicated thermal efficiency above 40%. A detailed 3D-CFD analysis is conducted to evaluate mixture formation, combustion behavior, abnormal combustion and water injection as a mitigation strategy. Innovative ring-shaped multi-point injection systems with several designs are tested, demonstrating the impact of injector channels’ orientation on the final mixture distribution. The combustion analysis shows that a dual-spark configuration ensures faster combustion compared to a single-spark system, with a 27.5% reduction in 10% to 90% combustion duration. Pre-ignition is identified as the main limiting factor, strongly linked to mixture stratification and high temperatures. To suppress it, water injection is proposed. A 55% evaporation efficiency of the water mass injected lowers the in-cylinder temperature and delays pre-ignition onset. Overall, the study provides key design guidelines for future high-performance hydrogen-fueled 2S-OP engines. Full article

Background: End-stage renal disease (ESRD) patients on haemodialysis present a high burden of cardiovascular comorbidities and require anticoagulation, which increases bleeding risk. Methods: We performed a retrospective observational study (2021–2024) in the Haemodialysis Centre of The Clinical Emergency Hospital of Constanta County, Romania, including 50 adults with stage G5 CKD on haemodialysis for ≥3 months and receiving anticoagulant therapy. We collected from electronic medical records detailed demographic data (age, sex, place of residence), comorbidities (hypertension, atrial fibrillation, ischaemic heart disease, diabetes, deep-vein thrombosis, stroke, myocardial infarction, pulmonary embolism, cirrhosis), lifestyle factors (smoking and alcohol consumption), vascular access type (arteriovenous fistula or central venous catheter) and laboratory parameters (haemoglobin, haematocrit, creatinine, albumin, total protein, electrolytes, LDL- and HDL-cholesterol, total cholesterol, INR, APTT, D-dimer, BNP, CK-MB, troponin). All laboratory units were standardised and checked for plausibility. Results: Median age was 71 years; 48% were female. The most common comorbidities were: hypertension (100%), atrial fibrillation (100%) and ischaemic heart disease (62–81%). Patients exhibited severe anaemia (mean Hb ~9.7 g/dL), nephrotic-range proteinuria, hypoalbuminaemia, and impaired coagulation profiles (INR ~1.8–1.9; prolonged APTT in men). Female patients had higher platelet counts and D-dimer levels, suggesting a stronger prothrombotic profile, while males showed longer APTT. Cardiovascular strain was reflected by elevated BNP in men and also troponin/CK-MB. Correlations included smoking with leukocytosis, alcohol with increased urine density, diabetes with higher urea and lower protein, and subtherapeutic INR in cerebrovascular disease. Conclusions: Patients with ESRD on haemodialysis and anticoagulant therapy display a complex interplay of cardiovascular comorbidities, anemia, overlapping thrombotic and bleeding risks, with sex-specific differences. Therefore, systematic monitoring of proteinuria, haemoglobin, D-dimer, and coagulation markers is crucial to balance thrombotic and bleeding risks. Objective: To characterise the clinical and paraclinical profile and comorbidity–laboratory correlations of ESRD patients undergoing haemodialysis and anticoagulant therapy. Full article

The structural parameters of Stewart platforms play a critical role in enhancing dynamic performance, improving motion accuracy, and enabling effective control strategies. However, practical applications face several key limitations, including the metric balancing for optimization, the limited singularity-free workspace, and low computational efficiency. To overcome those shortcomings, this work proposes a multi-objective optimal design of the structural parameters for Stewart platform based on Non-dominated Sorting Genetic Algorithm III (NSGA-III) and Kolmogorov–Arnold Network (KAN). Firstly, under the stroke constraints of the Stewart platform, this work focuses on optimizing the platform’s key structural parameters. This approach enables both the optimization of existing equipment and the design of new devices. Secondly, this work employs KAN to establish a model that characterizes the relationship between the structural parameters and diverse postures within the maximum singularity-free workspace. This approach not only enhances computational efficiency but also ensures high precision. Finally, this study proposes six performance metrics and utilizes NSGA-III to optimize the structural parameters, thereby achieving a trade-off among these diverse objectives. Simulation and experimental results demonstrate that KAN significantly outperforms the Multi-Layer Perceptron (MLP) in predicting workspace postures. Compared with MLP, KAN achieves higher prediction accuracy and lower error rates across both training and test datasets. When comparing NSGA-III with NSGA-II, the proposed approach demonstrates modest improvements in most performance metrics while preserving acceptable trade-offs between the optimization objectives. Full article