Journals
2025 EN
Shao Beili · Adeyemi Oluwatobi F · Gowland Penny
+14 more
Abstract Background Post‐COVID cognitive dysfunction is a critical extrapulmonary complication of COVID‐19. A previous post‐mortem study has shown neuroinflammation and loss of hippocampal neurogenesis in COVID‐19 case. High‐resolution 7T MRI enables detailed assessment of hippocampal subfields, providing insights into disease process and early changes. This study explores hippocampal subfield volumes using 7T MRI in Alzheimer’s disease (AD) and post‐COVID‐19 conditions, examining potential similarities in brain degeneration. Method We analysed hippocampal subfield volumes in four groups: (1) AD patients with confirmed CSF‐Aβ status ( n = 32), (2) individuals recovering from mild COVID‐19 >6 months post‐infection (Cv, n = 13), (3) individuals recovering from severe COVID‐19 with ICU admission >6 months prior (ICU‐Cv, n = 9), and (4) age‐matched healthy controls (HC, n = 29). Cognitive assessments, including the Montreal Cognitive Assessment (MOCA), were performed within these groups. Result AD patients exhibited significant atrophy in multiple hippocampal subfields, including the entorhinal cortex (ERC), dentate gyrus (DG), hippocampal tail (Tail), and cornu ammonis (CA), compared to HC and Cv. In ICU‐Cv, ERC volume was significantly reduced compared to HC, while Cv showed no subfield differences from HC. AD patients had smaller ERC and DG volumes compared to ICU‐Cv. Average MOCA scores were lowest in AD (13.52), significantly lower than HC (27.58), Cv (27.24), and ICU‐Cv (24.78). ICU‐Cv showed a trend toward lower MOCA scores than HC, but differences were not significant. MOCA scores for ICU‐Cv were significantly lower than Cv. AD patients performed worse than ICU‐Cv on multiple cognitive domains, including verbal fluency (vegetable and animal naming), working memory (the longest digit span backward), visuospatial function (Benson figure copy), and episodic memory (total story recall and verbatim scoring). ICU‐Cv patients also scored lower on Benson figure copy ( p = 0.048) and vegetable naming ( p = 0.047) compared to HC. Conclusion ERC, a key gateway for neocortical input to the hippocampus, is particularly susceptible in the early stages of AD, contributing to deficits in episodic memory and spatial navigation. In ICU‐Cv patients, we found selective atrophy of the ERC. This finding suggests that severe COVID‐19 may lead to targeted neurodegeneration through mechanisms distinct from AD but potentially overlapping in terms of hypoperfusion, inflammation, and metabolic stress.
Journals
2025 EN
Bahrani Ahmed A · Jessup Michael Tyler · Ibrahim Moaz W
+4 more
Abstract Background White matter hyperintensities (WMH) are associated with cerebrovascular disease (CVD) and cognitive decline, yet their underlying microstructural integrity remains poorly understood. WMH exhibits dynamic behavior, with regions that may grow, remain stable, or regress over time. However, few techniques systematically track longitudinal WMH changes. Diffusion tensor imaging (DTI)‐based fractional anisotropy (FA) provides insights into white matter (WM) microstructure. This study investigates the WM diffusivity based on FA values within WMH growth, regression, normal‐appearing white matter (NAWM), and total WMH using a novel longitudinal WMH growth/regression pipeline, validated within the MarkVCID consortium. Method Seventy‐six 3D FLAIR and T1‐weighted images from the University of Kentucky were analyzed longitudinally using the MarkVCID WMH growth/regression pipeline, which precisely quantifies dynamic changes in WMH regions. FA masks generated from DTI sequences were registered to T1‐weighted images to extract FA values from four key regions: (1) newly developed WMH (growth), (2) regressing WMH (regression), (3) NAWM, and (4) total WMH. Statistical analyses were conducted to compare FA differences across these regions. Result Significant FA differences were observed among all regions ( p < 0.001), except between WMH growth and regression. Total WMH exhibited the lowest FA, indicating substantial white matter disruption. WMH growth and regression regions showed intermediate FA values, suggesting a partial microstructural recovery in regressing WMH and progressive damage in newly developed WMH. NAWM exhibited the highest FA, reinforcing widespread microstructural compromise in total WMH. Conclusion These findings highlight the heterogeneous nature of WM microstructural alterations. The WMH growth/regression pipeline enables a refined assessment of white matter integrity beyond traditional volumetric measures. This approach holds promise as a novel neuroimaging biomarker for cerebrovascular disease and Alzheimer’s disease, providing valuable insights into white matter damage reversibility and its implications for cognitive decline. Future studies should explore longitudinal FA trajectories to further characterize white matter pathophysiology in aging and neurodegenerative conditions.
Journals
2025 EN
Islam Md. Rezaul · AlImran Md. Ibrahim Khalil · Zehravi Mehrukh
+11 more
Abstract Background Neurodegenerative diseases (NDs), including Alzheimer‘s disease, Parkinson‘s disease, and Huntington‘s disease, are complex and challenging due to their intricate pathophysiology and limited treatment options. Methods This review systematically sourced articles related to neurodegenerative diseases, neurodegeneration, quercetin, and clinical studies from primary medical databases, including Scopus, PubMed, and Web of Science. Results Recent studies have included quercetin to impact the cellular and molecular pathways involved in neurodegeneration. Quercetin, a flavonoid abundant in vegetables and fruits, is gaining attention for its antioxidant, anti‐inflammatory, and antiapoptotic properties. It regulates signaling pathways such as nuclear factor‐κB (NF‐κB), sirtuins, and phosphatidylinositol 3‐kinase/protein kinase B (PI3K/Akt). These pathways are essential for cellular survival, inflammation regulation, and apoptosis. Preclinical and clinical studies have shown that quercetin improves symptoms and pathology in neurodegenerative models, indicating promising outcomes. Conclusions The study explores the potential of incorporating laboratory research into practical medical treatment, focusing on quercetin‘s neuroprotective effects on NDs and its optimal dosage.
Journals
2025 EN
Mohammadzadeh Mohammad · Günay Elif Elçin · Jackman John
+2 more
ABSTRACT Accurate identification of defects on metal surfaces is of great interest to many industry sectors, such as the automotive and aerospace industries. In contrast to conventional manual inspection techniques, recent automated inspection systems employ deep learning models trained to detect defects rapidly and precisely. The development of these models often requires a substantial image dataset to acquire adequate knowledge of defect features and enhance their predictive accuracy. When data is limited, augmentation techniques are often used to improve the precision and accuracy of defect detection systems. This study examined the prediction performance of two object detection models, namely Faster Region‐based Convolutional Neural Network (Faster R‐CNN) and You Only Look Once version 8 (YOLOv8), to identify dent defects in limited images of cast iron cylinder head surfaces. The original image set contains 46 images with 563 dents. To overcome limited data availability, common image augmentation techniques along with a copy‐paste method were applied. Results show that standard augmentation improved YOLOv8 accuracy by 8.00% and average precision (AP) by 3.00%. On the other hand, the copy‐paste technique achieved a 20.00% increase in accuracy and a 1% increase in AP with just 200 synthetic dents. These results provide support for using the copy‐paste augmentation strategy to enhance defect detection performance, with a limited dataset, contributing to more accurate defect identification in remanufacturing processes.
Journals
2025 EN
Genç İbrahim
Abstract The electronic transmission properties of two‐terminal graphene nanoribbon (GNR) devices, featuring ring and ladder geometries with varying sizes, are investigated to understand the influence of explicit charge doping on their electrostatic control. The results indicate that explicit charge doping affects the device behavior, from single electron transport to resonant transport for different channels. When charge doping is applied, it induces quantum dot formation electrostatically, causing the ladder‐type channel GNR with a channel length of 49.7 Å to function similarly to a quantum dot. Therefore, this smallest ladder type channel shows current oscillations which are attributed to single‐electron tunneling. As the channel length increases in ladder‐type devices, a current path develops within the channel, forming a conductive path in larger devices that results in significant current and eliminates the tunneling barrier effect. On the other hand, for the ring‐shaped GNRs, it is found that the transport behavior gradually shifts from an antiresonant to a resonant transport regime with increasing radius under explicit charge doping. These results show a strong competition between quantum‐confinement effects and quantum dot‐to‐electrode coupling for both geometries when explicit charge doping is applied.
Journals
2025 EN
Das Gobinda · Singha Roy Suprobhat · Abou Ibrahim Fayrouz
+15 more
Abstract Developing a low‐cost, robust, and high‐performance electrocatalyst capable of efficiently performing both the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER) under both basic and acidic conditions is a major challenge. This area of research has attracted much attention in recent decades due to its importance in energy storage and conversion. Herein, we report the synthesis of two imine‐linked isoindigo‐based covalent organic networks I‐TTA and I‐TG (I=Isoindigo, TTA=4,4′,4′′‐(1,3,5‐triazine‐2,4,6‐triyl)‐trianiline, TG=triamino‐guanidinium hydrochloride salt). By introducing two amine core units with different planarity, such as triazine and ionic guanidinium units, we control the morphology, crystallinity, and corresponding electrocatalytic properties of the materials. The combination of isoindigo dialdehyde with a planar triazine core, leads to the formation of thin, highly crystalline, planar two dimensional (2D) nanosheets covalent organic framework (COF), I‐TTA whereas its combination with ionic non‐planar guanidinium core leads to an amorphous covalent organic polymer (COP), I‐TG with a fibrous morphology. The sheet‐like crystalline I‐TTA COF shows better electrocatalytic activity compared to the amorphous fibrous I‐TG COP. I‐TTA exhibits a current density of 10 mA cm −2 at an overpotential of ~134 mV for HER (in 0.5 M H 2 SO 4 ) and ~283 mV for OER (in 1 M KOH). The electrocatalytic activity of the I‐TTA COF in the OER exceeds that of other metal‐free COFs. The catalytic activity is maintained even after 24 hours of chronoamperometry and 500 cycles of cyclic voltammetry (CV) at high scan rates.
Journals
2025 EN
Chen Hengyue · Ruan Pengchao · Zhang Hao
+4 more
Abstract Despite the widespread interest in electrolytic Zn‐MnO 2 batteries with excellent output voltage and high theoretical capacity, the spontaneous disproportionation reaction of free Mn 3+ along with the disorderly deposited inactive MnO 2 results in the low Mn 2+ /MnO 2 conversion reversibility, which seriously affects their cycling stability. Here, we propose a novel aqueous SiO 2 colloidal electrolyte with FeSO 4 mediator (denoted as SF electrolyte) based on a bidirectional electrochemical‐chemical model to achieve dual regulation of the MnO 2 deposition/dissolution process. During the charging process, the SiO 2 colloidal particles located at the carbon felt interface and the electrolyte bulk phase simultaneously provide sufficient disproportionation sites for the diffused Mn 3+ to guide the orderly rapid deposition of MnO 2 . Meanwhile, the introduction of Fe 2+ mediators during the discharge process can sufficiently react with MnO 2 on the SiO 2 particles in the electrolyte, thereby further enabling the efficient conversion of Mn 2+ /MnO 2 . Consequently, electrolytic Zn‐MnO 2 battery with SF electrolyte can stably run for 550 cycles at 10 mAh cm −2 and achieve superior reversibility at a high area capacity of 20 mAh cm −2 . This work demonstrates the feasibility of colloidal electrolytes in modulating electrochemical‐chemical processes to stabilize electrolytic Zn‐MnO 2 batteries.
Journals
2025 EN
Wu Jiajun · Chugh Vishal · SharpBucknall Lachlan
+3 more
A single propargylic alcohol beam enters a catalyst prism and splits into three product beams via adaptive rhodium catalysis assisted by a Lewis‐acidic secondary sphere. In their Communication ( e202515903 ), Christophe Werlé and co‐workers describe a rhodium catalyst featuring a triazine ligand with a borane arm that selectively transforms a propargylic alcohol into retained alkynes, allylic ethers, or (E)‐alkenes.
Journals
2025 EN
Wu Jiajun · Chugh Vishal · SharpBucknall Lachlan
+3 more
Abstract Achieving chemoselective transformations of multifunctional molecules under mild and sustainable conditions remains a central challenge in catalysis. Here, we show that a rhodium complex equipped with a Lewis acidic secondary coordination sphere can mediate condition‐dependent, divergent hydrogenation of propargylic alcohols. By tuning the reaction medium, the system selectively yields one of three products—retained alkynes, allylic ethers, or ( E )‐alkenes—from a single substrate–catalyst pair under hydrogen. Mechanistic studies implicate π‐allyl and rhodium hydride intermediates, with solvent polarity and nucleophilicity steering the reaction pathway. Control experiments confirm the critical roles of both molecular hydrogen and the boron Lewis acid in enabling divergent selectivity. These findings demonstrate how rational secondary‐sphere design can enable adaptive catalysis and provide a platform for programmable bond transformations in multifunctional substrates.
Journals
2025 EN
Rathmann Florian · Abdelsalam IbrahiM · Wang Shiqi
+8 more
Abstract Plasmonic‐catalytic nanostructures enable coupling light harvesting with chemical transformations, yet their performance critically depends on nanoscale architecture and metal‐support interactions. Here, we synthesize Au@Ru core–shell nanoparticles with tunable Ru coverage and immobilize them on TiO 2 to create hybrid catalysts for CO 2 methanation. By controlling Ru shell thickness, we identifyAu 60 Ru 40 /TiO 2 , featuring a thin, discontinuous shell (∼2 nm Ru nanocrystallites), as the most active composition. This catalyst combines abundant Ru active sites with preservation of the Au core's localized surface plasmon resonance (LSPR). Under 545 nm illumination, it shows a 335% rate enhancement over dark conditions at 190 °C, outperforming commercial Ru/C and remaining stable for 85 h. Optical, structural, and kinetic analysis indicate that illumination accelerates the methanation without changing the rate‐determining step, consistent with a dominant photothermal contribution. Density functional theory reveals that TiO 2 induces strong metal‐support interactions, upshifts the Ru d‐band center, strengthens CO 2 adsorption, and lowers the barrier for the first hydrogenation step, shifting the rate‐limiting step to CH 4 desorption. These results establish Au@Ru/TiO 2 as an efficient platform for visible‐light‐assisted thermocatalysis and demonstrates that nanoscale shell engineering as a generalizable strategy to optimize plasmonic catalysts for CO 2 hydrogenation and beyond.