Search Results (796)

Introduction: Contrast-induced encephalopathy (CIE) is a rare condition with a broad spectrum of neurological symptoms. With the increasing use of endovascular techniques, the disease is becoming ever more important. To date, recent studies have primarily described patients with early-onset CIE, in which symptoms appear shortly after the intervention. This case report represents one of the few reported cases of late-onset CIE. Case description: A 53-year-old woman with a re-recurrent anterior communicating artery aneurysm with coil impaction and a history of two aneurysmal subarachnoid hemorrhages underwent stent-assisted re-recoiling without incident. Some 31 h after the procedure, she experienced a generalized tonic–clonic seizure. Postprocedural magnetic resonance imaging (MRI) earlier that day had shown slight cortical swelling and mild leptomeningeal effusion in the left frontal lobe, without any other abnormalities. Computerized tomography (CT) imaging afterwards ruled out intracranial hemorrhage. Following an otherwise uneventful clinical course, the patient developed impaired vigilance, right-sided leg weakness, and fine-motor impairment of the hand on the sixth day after the intervention. Subsequent MRI demonstrated patent intracranial arteries and no evidence of ischemia. However, the imaging findings were consistent with CIE, showing characteristic cortical swelling and signal alterations in the sulcal subarachnoid space. In addition, multiple cerebral microbleeds were identified. After the initiation of dexamethasone therapy, the patient exhibited prompt neurological improvement, with full neurological recovery at the three-month follow-up. Conclusions: This case appears to be one of the rare documented occurrences of late-onset CIE, highlighting the importance of postinterventional neurological monitoring. Furthermore, it suggests the potential role for high-dose corticosteroid therapy. Full article

To overcome the limitations imposed by the natural ionosphere on high-frequency (HF) communication systems, the generation of artificial electron clouds through space-based release of ionizable materials offers a controllable means of constructing localized plasma environments. However, a systematic mapping between release parameters and radio wave propagation characteristics is still lacking, which restricts engineering applications. This paper establishes a full-chain simulation framework that links release parameters, cloud morphology, and propagation characteristics by combining a two-fluid hydrodynamic model with ray tracing. Results show that as release altitude rises from 150 km to 210 km, the cloud undergoes pronounced stretching along the magnetic field (the cloud scale grows from 17.28 km to over 80 km), resulting in a broader signal shadow zone (expands from 116 km to 170 km) and a marked increase in multipath delay spread. Increasing mass from 4 kg to 12 kg raises peak electron density from 7.416 × 10¹² to 2.154 × 10¹³ m⁻³ and widens the shadow zone from 144 km to 174 km. Raising the ionization rate from 20% to 80% broadens the enhancement zone but reduces the shadow zone. Higher altitudes favor broad shielding, larger masses enhance scattering strength and duration, while higher ionization rates accelerate cloud evolution for rapid response and lower rates provide stable coverage. These findings can provide theoretical guidance for the precise design of artificial electron clouds tailored to different application requirements. Full article

Background/Objectives: Stroke-related aphasia significantly impairs communication and quality of life (QoL). Constraint-induced aphasia therapy (CIAT) and repetitive transcranial magnetic stimulation (rTMS) are evidence-based approaches targeting language recovery. No combined protocol exists for Greek, a morphologically complex language. The present study was designed as a feasibility pilot, with the primary objective of determining if a modified CIAT (mCIAT) protocol, with or without continuous theta burst stimulation (cTBS), could be delivered safely and acceptably in a Cypriot clinical context, while also reporting the first mCIAT protocol adapted for Greek. Methods: A single-subject experimental design (SSED) was employed. Two participants (PAs) with chronic anomic aphasia underwent a 10-day treatment protocol. PA1 received sham cTBS plus mCIAT-GR; PA2 received real cTBS (to the right inferior frontal gyrus) plus mCIAT. Multiple language, cognitive, and QoL measures were administered across three baselines and two follow-up time points. Results: Both PAs completed the full protocol with 100% session adherence and no adverse effects, establishing the feasibility of delivery. Neither participant showed improvements in standardized expressive language measures following mCIAT with or without cTBS; Standard Error of Measurement (SEM) analysis confirmed that observed score fluctuations on most measures fell within expected measurement noise. PA2 showed improvement in QoL (SAQOL-39g) domains at the two-year follow-up, though this finding requires cautious interpretation given the follow-up interval and regression-to-mean considerations. Conclusions: The Greek mCIAT protocol is feasible and safe to deliver in a Cypriot clinical setting. The absence of clear language improvements may reflect several factors, including ceiling effects, limited assessment sensitivity, insufficient treatment dosage, or limited intervention effects. These findings should be interpreted cautiously and require confirmation in larger, adequately powered studies. Full article

Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) has the potential to characterize the size and composition of quantum dots (QDs). However, examples of its usage in the literature are limited. In this study, we perform an in-depth characterization of the size and composition of the CdSe QD system using a combination of MALDI MS and nuclear magnetic resonance (NMR). Using these techniques, we determine the size and composition of a series of wurtzite and zincblende CdSe QDs. The composition ranges from 176 to 1202 CdSe units per QD. With this information, we construct a sizing curve for the QDs and compare it with sizing curves from the literature obtained using other techniques such as transmission electron microscopy (TEM) and small-angle X-ray scattering (SAXS). These results will be insightful for the community developing complex multilayer QD compositions for photonic applications. Full article

Dark fermentative biohydrogen (bio-H₂) production is a promising renewable energy technology for converting organic waste and wastewater into clean fuel. However, practical application is limited by low H₂ yield, volatile fatty acid (VFA) accumulation, incomplete substrate utilization, electron diversion to competing pathways, prolonged lag phases, and inhibitory byproducts from lignocellulosic pretreatment. Magnetite nanoparticles (Fe₃O₄ NPs) have attracted attention as redox-active additives because of their electrical conductivity, reversible Fe²⁺/Fe³⁺ cycling, magnetic recoverability, biocompatibility, and microbial interaction potential. This review examines the physicochemical properties of Fe₃O₄ NPs and their proposed roles in dark fermentative bio-H₂ production. Particular emphasis is placed on Fe₃O₄-mediated extracellular electron transfer (EET) in fermentative communities, which differs from direct interspecies electron transfer (DIET) in methanogenic systems. Fe₃O₄ NPs may enhance bio-H₂ production by facilitating electron transfer, supporting hydrogenase activity, regulating redox balance, promoting acetate- and butyrate-type pathways, and enriching H₂-producing bacteria such as Clostridium spp. Hybrid systems combining Fe₃O₄ with biochar, activated carbon, reduced graphene oxide, bimetallic nanocomposites, or immobilization matrices may further improve microbial retention and process stability. Remaining challenges include aggregation, dosage-dependent toxicity, recovery, environmental fate, mechanistic uncertainty, and scale-up feasibility. Full article

Wireless power transfer (WPT) technology offers reliability, safety, and ease of use for low-power charging applications. However, output regulation is difficult when the secondary side is inaccessible, because the magnetic coupling factor $k$ and the equivalent load resistance $R_L$may both be unknown and variable. This work addresses the two unknown parameters problem using only primary-side measurements of the DC-link voltage $V_{DC}$and the primary resonant current $I_1$. An initial calibration stage temporarily connects a known resistance on the receiver side, making it possible to estimate $k$ without a secondary-to-primary communication link. Then, during the charging stage, the previously estimated coupling is used to estimate the equivalent load resistance and to indirectly regulate the charger input voltage through a primary-side pre-regulator. The proposed system is intended for low-power WPT chargers, in which the receiver side must be simple and compact. A resonant DC converter prototype was experimentally implemented using a Class-E inverter, a Series-Series compensation network, a full-bridge rectifier, primary-side voltage/current sensing, and a pre-regulator. The experimental results show a maximum coupling identification error of 3.9% and a maximum load-resistance identification error of 10.67%. The resulting output voltage is not measured directly at the load; instead, it is estimated from primary-side variables and maintained within the 4–6 V input window of the target charger around a 5 V reference, with a maximum relative voltage error of approximately 10%. The work therefore presents a primary-side identification and control proof of concept without secondary-to-primary communication, while explicitly discussing the calibration requirement, equivalent-load validation, efficiency limitations, and the conditions under which recalibration would be required. Full article

Background: In the coming decades, the agricultural system will increasingly rely on organic amendments to sustain crop production, maintain soil health and ensure long-term food security. While inorganic fertilizers remain widely used for vegetable production due to their rapid nutrient availability, their prolonged application has been shown to degrade soil quality, disrupt microbial communities and limit the nutritional quality of harvested produce. Consequently, there is a growing need to explore organic alternatives such as biochar and poultry manure that can enhance both crop productivity and functional quality. Objective: This study aimed to determine the influence of different application rates of biochar (5/T₁, 10/T₂, and 20/T₃ t/ha), poultry manure (10/T₁, 20/T₂, 30/T₃ t/ha), and NPK (2:3:4) as control on the metabolomic profile of tomato fruit. Methods: The metabolomic profile was determined using 1H-nuclear magnetic resonance (NMR). Results: Common metabolites across biochar rates included allantoin, asparagine and betaine, while rate-specific released metabolites such as inosine (T₁), epicatechin (T₂) and kynurenine (T₃) were also identified. Similarly, poultry manure showed an array of metabolites at the highest application rate, with metabolites such as cellobiose, creatinine and maltose, while histamine (T₁) and ADP (T₃) were also detected as distinct metabolites. Full article

Patients with muco-obstructive lung disease (MOLD) exhibit chronic bronchitis and inflammation, along with a progressive decline in lung function. Lung monitoring is typically performed using spirometry, especially by measuring the forced expired volume in the first second (FEV₁). However, the limitations of spirometry motivated the exploration of alternative approaches. The spin–spin relaxation time (T_2m) and the spin–lattice relaxation time (T_1m) of sputum water hydrogens were measured using low-field nuclear magnetic resonance (LF-NMR) in 38 MOLD patients and 16 controls. The levels of TNFα/IL-6, the sputum microbiome composition/amount/indices and FEV₁ were determined in parallel. We also investigated the correlation between T_2m/T_1m and the disease index (I_D); I_D, calculated relying on patient FEV₁/TNFα/IL-6/bacteria concentration C_b values, is a measure of the patient’s distance from the average healthy control. We observed the following significant correlations: T_2m/T_1m with I_D, T_2m with C_b, a potential correlation of T_2m with the bacteria genera Streptococcus and Staphylococcus, T_2m with the Shannon index, which reflects the broadness of the bacterial community in the sputum, and T_2m with TNFα. FEV₁ did not show any correlation. Our noninvasive/radiation-free/portable method of T_2m/T_1m measurement shows potential value in monitoring lung conditions in MOLD patients and may contribute to improved clinical decision-making. Full article

With the pervasive deployment of 5G communication systems and electronic devices, electromagnetic (EM) pollution has emerged as a critical environmental concern. Due to their wide availability, low cost, and ease of acquisition, biomass materials have been widely used in the preparation of electromagnetic wave absorption materials. Compared with traditional in situ impregnation methods, this study first employs chemical reagents to reduce the lignin content within balsa wood, thereby opening more pores and enhancing the loading capacity of iron salts. Subsequently, magnetic Fe₃O₄ particles are synthesized in situ, enabling the fabrication of magnetic wood-based composites. Compared with the non-impregnated pure carbonized samples, the reflection loss value of the samples with magnetic particles increased to −42.37 dB, corresponding to a matching thickness of 1.5 mm. This is much better than the −8.79 dB of the pure carbonized samples, and is attributed to multiple loss mechanisms. In addition, modern physical and chemical analysis instruments such as SEM, TEM, XRD, XPS, and Raman were used to characterize the physical and chemical changes of the materials. Finally, its applications in aerospace and thermal response were identified. Full article

In this work, resonator applications based on the magnetoelectric coupling effect in multiferroic materials are systematically investigated, with particular emphasis on mechanically driven ME antennas. A finite-element model is established to analyze the electromechanical response and coupling behavior of the device. To better describe the converse ME process, a nonlinear magnetostrictive model is introduced to evaluate the influence of material properties, structural configuration, and DC bias magnetic field on resonance characteristics and radiation performance. The simulation results show that the radiation intensity of the ME antenna is strongly dependent on the applied bias magnetic field and can be significantly enhanced under the optimal operating condition. On this basis, key parameters are optimized to reduce the resonance frequency and improve the radiation response. Prototype devices are then fabricated and experimentally characterized. The measured results verify the predicted resonance behavior and demonstrate the feasibility of the proposed devices in low-frequency wireless communication and magnetic-anomaly sensing. This study provides theoretical guidance and experimental support for the design of portable low-frequency ME antenna systems and other resonator-based magnetoelectric devices. Full article

The assessment of consciousness has been shaped largely by research on acquired disorders of consciousness after acute or chronic brain injury, but similar problems of unreliable behavioral expression increasingly arise in neurodegenerative disease. This translational overlap is especially relevant when preserved cognition, awareness, or intentionality cannot be reliably expressed because of severe motor impairment, fluctuating arousal, cognitive decline, aphasia, apraxia, or impaired cooperation. In neurodegenerative disease, degeneration of arousal systems, large-scale brain networks, cognition, and motor pathways may similarly make observable behavior an unreliable measure of awareness. The challenge is not only to determine if a patient responds, but also to ask if residual awareness, intentionality, or covert cognition can still be detected through physiological signals. This review discusses how contemporary modalities reshape this assessment. Electroencephalography has moved from a descriptive measure of background activity to a bedside tool capable of probing event-related responses, network organization, and cortical complexity. Magnetic resonance methods reveal altered connectivity within thalamocortical and default mode network systems, while functional near-infrared spectroscopy adds a portable hemodynamic approach that may be repeated at the bedside and integrated with active paradigms. Brain–computer interfaces provide a translational step by converting neural responses into evidence of command following or, in selected patients, into communication, and artificial intelligence strengthens these approaches by extracting clinically meaningful patterns from complex neural and hemodynamic data. Additionally, autonomic measures, including heart rate variability and baroreflex indices, are considered as auxiliary physiological context for arousal and engagement, and not as direct markers of awareness. Because the most mature evidence for covert awareness and cognitive-motor dissociation comes from acquired disorders of consciousness, this review treats brain injury literature as a methodological foundation instead of as directly interchangeable evidence for neurodegenerative disease. It then examines how these approaches may be adapted to neurodegenerative contexts, especially ALS, severe dementia, Lewy body disease with fluctuating cognition, and conditions in which communication or motor output becomes unreliable. Full article

To address the problem of three-dimensional (3D) localization in underwater environments, this paper proposes a 3D positioning method based on magnetic induction communication (MI in short). Dual transmitters equipped with 3D coils are used to transmit magnetic field signals, while a single receiver with 3D coils is adopted to receive signals. Three-dimensional position calculation is realized by collecting induced voltage from the receiving 3D coils, which enables any device at a known position in space to provide positioning services for other devices. To eliminate abnormal data and suppress environmental noise interference in underwater received signals and further improve positioning performance, an improved density clustering algorithm named the Density-Based Spatial Clustering Method in Magnetic Positioning is proposed to remove erroneous positioning data. In addition, Kalman filtering is introduced to jointly suppress environmental noise interference. Experimental results demonstrate that the average positioning error of the proposed localization method is 0.67 m and maximum positioning error is 0.83 m; therefore, this paper provides a novel technical solution for underwater positioning in non-line-of-sight environments. Full article

Background: Neuromodulation is a rapidly developing field with growing interest in its application in neuro-oncology, particularly since the publication of the EF-14 trial which demonstrated a survival benefit conferred by tumour treating fields (TTF) in patients with glioblastoma. In addition, the emerging field of cancer neuroscience has postulated the role of neural–tumour communication in tumour aetiology, which is theoretically targetable by neuromodulation strategies. This scoping review therefore aims to comprehensively evaluate current or future applications of neuromodulation in managing patients with brain tumours, encompassing preclinical and clinical studies. Methods: The MEDLINE database was queried for all relevant articles from inception to 1 December 2024. A synthesis of findings was performed, broadly categorised to preclinical and clinical research. Findings: The database search returned 3296 results, from which 187 full-text articles were further assessed. A total of 79 studies met the inclusion and exclusion criteria and were included. The results from preclinical studies (n = 18) were stratified according to modality which included electrical therapy, electroporation, electromagnetic field (EMF) and deep brain stimulation (DBS). Similarly, clinical studies (n = 61) were classified to preoperative modalities such as transcranial magnetic stimulation (TMS) and transcranial direct stimulation (tDCS), and postoperative modalities such as TMS, TTF, EMF and spinal cord stimulation (SCS). Interpretation: The application of neuromodulation as adjunctive therapy in the context of neuro-oncology is an emerging field, with encouraging results in various modalities across a wide range of applications from surgical planning and functional rehabilitation, to its therapeutic potential. Further research is urgently needed to harness the potential of neuromodulation in improving patient outcomes. Full article

Perovskite manganites (AMnO₃) and perovskite-like manganites (A′_1−xA_xMnO₃) are complex oxide materials that have attracted significant attention from the scientific community in recent years due to their structural flexibility, mixed-valence state, tunable electronic configuration, and multifunctional properties. This review systematically analyzes the synthesis methods, structural classification, and physicochemical characterization of perovskite manganites, as well as their magnetic, optical, electrical, dielectric, and catalytic properties. The influence of solid-state reactions, sol–gel, Pechini, hydrothermal, co-precipitation, microwave, and other mild chemical approaches on phase purity, morphology, particle size, and oxygen stoichiometry was examined. The structural diversity of perovskite and perovskite-like manganites, including simple ABO₃, double perovskites, multilayer, and low-dimensional systems, was characterized in relation to their functional properties. The review discussed the capabilities of methods for synthesizing and analyzing morphological properties, demonstrating the role of doping, cation substitution, oxygen vacancies, and Jahn–Teller distortions in controlling material properties. Prospects for the application of perovskite manganites in spintronics, magnetocaloric cooling, photocatalysis, gas-sensing devices, and energy conversion and storage systems were analyzed. This review highlights the structure–property–application relationship in perovskite manganites. Full article

With the advancement of electronics and communication technologies, there is growing interest in high-performance microwave-absorbing materials. The material composition and structural design are critical factors influencing the electromagnetic wave (EMW) absorption capabilities. X-type barium ferrite (Ba₂Co₂Fe₂₈O₄₆) exhibits advantages in enhancing high-frequency magnetic loss and interface polarization through its unique hexagonal crystal structure and morphological design, while also optimizing impedance matching to a certain extent. However, the effective absorption bandwidth (EAB) of single-phase barium ferrite is often restricted. Therefore, doping with other elements is necessary to broaden the EAB. In this study, La³⁺-substituted X-type hexagonal ferrites Ba₂Co₂Fe_28−xLa_xO₄₆ (x = 0.00, 0.05, 0.10, 0.15, and 0.20) were successfully synthesized via a high-temperature solid-state reaction method, and the effects of different La³⁺ doping concentrations on the electromagnetic parameters and wave-absorbing performance of Ba₂Co₂Fe₂₈O₄₆ were investigated. After doping, the materials demonstrated excellent electromagnetic absorption performance: when x = 0.15, RL_min = −48.36 dB; when x = 0.10, EAB = 9.03 GHz (RL ≤ −5 dB). Full article