Search Results (5,959)

We present a time-domain direct current (DC) approach to differentiate positive- (PE) and negative-electrode (NE) contributions from two-electrode full-cell signals in lithium-ion batteries, enabling electrode-resolved diagnostics without specialized instrumentation. The responses of a LiNi_0.8Co_0.1Mn_0.1O₂ (PE)/graphite (NE) cell were recorded across −20 to 20 °C during galvanostatic pulses and subsequent open-circuit relaxations, alongside electrochemical impedance spectroscopy (EIS) measurements. These responses were analyzed using an equivalent-circuit-based model to decompose them into terms with characteristic times. Their distinct temperature dependences enabled attribution of the dominant terms to PE or NE, especially at low temperatures where temporal separation is substantial. The electrode attribution and activation energies were cross-validated against three-electrode measurements and were consistent with EIS-derived time constants. Reconstructing full-cell voltage transients from the identified terms reproduced the measured electrode-specific behavior, and quantitative comparisons showed that the DC time-domain separation aligned closely with directly measured PE/NE overpotentials during the current pulse. These results demonstrate a practical pathway to extract electrode-resolved information from cell voltage alone, offering new methodological possibilities for battery diagnostics and management while complementing three-electrode and alternating current (AC) techniques that are often constrained in field applications. Full article

In this paper we present a brief review of extended general relativity in four dimensions and solve versions of the extended equations for the case of static spherical symmetry in various contexts, for a previously studied Lagrangian. The exterior vacuum yields a Schwarzschild solution with an additional scalar field potential that falls off logarithmically, the latter essentially an inverse square force. That is probably not adequate as a dark matter force, but might contribute. When a constant density field of ions holds sway in the exterior, a solution identical to the cosmological constant extension of Schwarzschild occurs, together with a scalar field potential declining as $r^{-3/2}$, however it is not asymptotically flat. An inverse square declining distribution of ionic material, according to perturbation theory, results in an additional linear gravity potential that would provide further attraction in the gravity term. A limited exact solution in the same case yields a cubic equation with a Schwarzschild solution, corresponding to $A=0$, and two MOND-like possible potentials, one vanishing at infinity, but a better solution must be found. The approximate solution is complex (one of many) and the system requires further study. Ionic matter is ubiquitous in the universe and provides a source for the scalar field, which suggests that the extended Einstein equations could be of utility in the dark matter problem, provided such an electromagnetic scalar force could be found and differentiated from the usual, far stronger electromagnetic forces. Further, it’s possible that the strong photon flux outside stars might have an influence, and is under current investigation. These calculations show that extending the concept of curvature and working in four dimensions with larger operators may bring new tools to the study of physics and unified field theories. Full article

The search for high-capacity, stable anode materials is crucial for advancing lithium-ion battery (LIB) technology. Although carbon nanotubes (CNTs) are known for their excellent electrical conductivity and mechanical strength, their practical capacity is still limited. This study presents an advanced anode design by molecular functionalizing both single-walled and multi-walled carbon nanotubes (SWCNTs and MWCNTs) with tetrabromocobalt phthalocyanine (CoPc), resulting in CoPc/SWCNT and CoPc/MWCNT hybrid materials. Metal phthalocyanines (MPcs) are recognized for their tunable and redox-active properties. In CoPc, the redox-active metal centers and π-conjugated structure are uniformly attached to the CNT surface through strong π-π interactions. This synergistic combination significantly boosts the lithium-ion (Li-ion) storage capacity by offering numerous coordination sites for Li-ions and enhancing charge transfer kinetics. Electrochemical analysis shows that the CoPc-SWCNT active anode electrode material shows an impressive reversible capacity of 1216 mAh g⁻¹ after 100 cycles at a current density of 0.1 A g⁻¹, substantially surpassing the capacities of pristine CoPc (327 mAh g⁻¹) and a CoPc/MWCNT hybrid (488 mAh g⁻¹). Furthermore, the CoPc/SWCNT anode exhibited exceptional rate capability and outstanding long-term cyclability. These results underscore the effectiveness of non-covalent functionalization with SWCNTs in enhancing the electrical conductivity, structural stability, and active site utilization of CoPc, positioning CoPc/SWCNT hybrids as a highly promising anode material for high-performance Li-ion storage. Full article

Background/Objectives: Since its emergence in late 2019, SARS-CoV-2 has demonstrated remarkable genetic diversity driven by mutations and recombination events that shaped the course of the COVID-19 pandemic. Continuous genomic monitoring is essential to track viral evolution, assess the spread of variants of concern (VOCs), and inform public health strategies. The present study aimed to characterize the molecular epidemiology of SARS-CoV-2 in northern Greece from the first national case in February 2020 through early 2025. Methods: A total of 66 respiratory samples collected from hospitalized patients across Northern Greece were subjected to whole-genome sequencing using Oxford Nanopore Technologies’ MinION Mk1C platform and the ARTIC protocol. Sequences were analyzed with PANGO, Nextclade, and GISAID nomenclature systems for lineage and clade assignment, and the WHO nomenclature for VOCs. Results: Across 66 genomes, 34 PANGO lineages were identified. Early introductions included B.1 (2/66), B.1.177 (3/66), and B.1.258 (1/66). Alpha (5/66) and Beta (5/66) circulated in February–June 2021. Delta (AY.43) was detected in early 2022 (2/66; Jan–Feb) but was rapidly displaced by Omicron and reached 100% of the sequences by May 2022. Omicron diversified into BA.1/BA.1.1 (3/66), BA.2 (6/66), BA.4/BA.5 (14/66), BF.5 (1/66), EG.5 (1/66; designated a WHO Variant of Interest in 2023), JN.1 (4/66; globally dominant lineage prompting vaccine updates in 2024–2025), KS.1 (2/66; together with KS.1.1 are recognized PANGO lineages that were tracked internationally but remained less prevalent), KP.3 (5/66; together with KP.3.1.1, prominent “FLiRT” descendants circulating in 2024), and recombinants XDK, XDD, and XEC (5/66), reported by their PANGO names in accordance with the WHO’s current framework, which reserves Greek letters only for newly designated VOCs. Conclusions: This five-year genomic analysis provides an insight into the continuous evolution of SARS-CoV-2 in northern Greece. The findings underscore the importance of sustained genomic surveillance, integrated with epidemiological data, to detect emerging variants, monitor recombination, and strengthen preparedness for future coronavirus threats. Full article

Organic field-effect transistors (OFETs) have emerged as a transformative platform for high-performance sensing technologies, yet their full potential can be realized only through coordinated performance optimization. This article provides a comprehensive review of recent strategies employed in polymer OFETs to enhance key parameters, including carrier mobility (μ), threshold voltage (Vth), on/off current ratio (I_on/I_off), and operational stability. These strategies encompass both physical and chemical approaches, such as annealing, self-assembled monolayers (SAMs), modification of main and side polymer chains, dielectric-layer engineering, buffer-layer insertion, and blending or doping techniques. The development of high-performance devices requires precise integration of physical processing and chemical design, alongside the anticipation of processing compatibility during the molecular design phase. This article further highlights the limitations of focusing solely on high mobility and advocates a balanced optimization across multiple dimensions—mobility, mechanical flexibility, environmental stability, and consistent functional performance. Adopting a multi-scale optimization framework spanning molecular, film, and device levels can substantially enhance the adaptability of OFETs for emerging applications such as flexible sensing, bioelectronic interfaces, and neuromorphic computing. Full article

Calmodulin (CaM) plays a central role in cardiac excitation–contraction coupling by regulating ion channels, including the L-type calcium (Ca²⁺) channel Ca_v1.2 and the voltage-gated potassium (K⁺) channel K_v7.1. Mutations in CaM are linked to severe arrhythmogenic disorders such as Long QT syndrome (LQTS), yet the molecular mechanisms remain incompletely understood. Here, we investigate the structural and functional consequences of the arrhythmia-associated CaM variant D133H. Biophysical analysis revealed that D133H destabilises Ca²⁺ binding at the C-terminal lobe of CaM, altering its Ca²⁺-dependent conformational changes. Electrophysiological recordings demonstrated that CaM D133H impairs Ca²⁺-dependent inactivation (CDI) of Ca_v1.2, prolonging Ca²⁺ influx, while also reducing activation of K_v7.1, thereby limiting repolarising K⁺ currents. Together, these dual defects converge to prolong action potential duration, providing a mechanistic basis for arrhythmogenesis in LQTS. Our findings establish that CaM D133H perturbs both Ca²⁺ and K⁺ channel regulation, highlighting a shared pathway by which calmodulinopathy mutations disrupt cardiac excitability. Full article

The rapid increase in retired lithium-ion batteries (LIBs) from electric vehicles (EVs) highlights the urgent need for accurate and automated end-of-life (EOL) assessment. This study proposes an AI-integrated smart grading system that combines hardware diagnostics and deep learning-based evaluation to classify the residual usability of retired batteries. The system incorporates a bidirectional charger/discharger, a CAN-enabled battery management system (BMS), and a GUI-based human–machine interface (HMI) for synchronized real-time data acquisition and control. Four diagnostic indicators—State of Health (SOH), Direct Current Internal Resistance (DCIR), temperature deviation, and voltage deviation—are processed through a deep neural network (DNN) that outputs categorical grades (A: reusable, B: repurposable, C: recyclable). Experimental validation shows that the proposed AI-assisted model improves grading accuracy by 18% and reduces total testing time by 30% compared to rule-based methods. The integration of adaptive correction models further enhances robustness under varying thermal and aging conditions. Overall, this system provides a scalable framework for automated, explainable, and sustainable battery reuse and recycling, contributing to the circular economy of energy storage. Full article

Mg-doped gallium oxide films were prepared on single crystal sapphire substrates through radio frequency magnetron sputtering technology, and then AlN films of different thicknesses were deposited on them as passivation layers. Finally, Pt interdigitated electrodes were prepared through mask plate and ion sputtering technology to make metal–insulator–semiconductor–insulator–metal (MISIM) photodetectors. The influence of the AlN passivation layer on the optical properties and photodetection performance of the device was investigated using UV-Vis (ultraviolet-visible absorption spectroscopy) spectrophotometer and a Keith 4200 semiconductor tester. The device’s performance was significantly enhanced. Among them, the MISIM-structured device achieves a responsivity of 2.17 A/W, an external quantum efficiency (EQE) of 1100%, a specific detectivity (D*) of 1.09 × 10¹² Jones, and a photo-to-dark current ratio (PDCR) of 2200. The results show that different thicknesses of AlN passivation layers have an effect on the detection performance of Mg-doped β-Ga₂O₃ films in the UV detection of the solar-blind UV region. The AlN’s thickness has little effect on the bandgap when it is 3 nm and 5 nm, and the bandgap increases at 10 nm. The transmittance of the film increases with the increase in AlN thickness and decreases when the AlN’s thickness increases to 10 nm. The photocurrent exhibits a non-monotonic dependence on AlN thickness at 10 V, and the dark current gradually decreases. The thickness of the AlN passivation layer also has a significant impact on the response characteristics of the detector, and the response characteristics of the device are best when the thickness of the AlN passivation layer is 5 nm. The responsiveness, detection rate, and external quantum efficiency of the device first increase and then decrease with the thickness of the AlN layer, and comprehensive performance is best when the thickness of the AlN passivation layer is 5 nm. The reason is that the AlN layer plays a passivating role on the surface of Ga₂O₃ films, reducing surface defects and inhibiting its capture of photogenerated carriers, while the appropriate thickness of the AlN layer increases the barrier height at the semiconductor interface, forming a built-in electric field and improving the response speed. Finally, the AlN layer inhibits the adsorption and desorption processes between the photogenerated electron–hole pair and O₂, thereby retaining more photogenerated non-equilibrium carriers, which also helps enhance photoelectric detection performance. Full article

Background/Objectives: One of the neurotoxic components from the sea trumpet polyps, Protopalythoa variabilis (Cnidaria, Anthozoa), is a 26-residue, V-shape helical peptide (PpVα). Its synthetic versions, i.e., the linear, the single-disulfide-bonded analog, and the chimeric peptide with a 6-residue stretch of the N-terminal native homologous peptide covalently linked to the linear sequence, were investigated for their activity on ion channels responsible for cellular excitability and synaptic transmission. Methods: Molecular docking analyses and dynamic simulations focused on the ability of PpVα peptides to bind ion channels selectively through interaction with critical residues at their binding sites. Results: Electrophysiological studies using the patch clamp technique with sympathetic bovine chromaffin cells from the adrenal medulla confirmed that PpVα analogs can block both sodium and calcium currents, which are responsible for initiating and propagating action potentials, respectively, and for neurotransmitter release. Additionally, the peptides displayed neuroprotective effects, attenuating cellular damage induced by veratridine, which interferes with sodium channel activity, and by oligomycin and rotenone (O/R), which affect mitochondrial function. Conclusions: The block of calcium and sodium channels and the neuroprotective effects against oxidative stress make the PpVα peptide scaffold an attractive template for developing agents that has significant clinical potential in several areas, such as the treatment of neurological diseases (epilepsy, multiple sclerosis, and neurodegenerative diseases), neuroprotection in acute events (stroke and traumatic brain or spinal cord injuries), the management of neuropathic pain, the prevention of ischemic damage, and psychiatric disorders (anxiety and bipolar disorder). Full article

Functionalized nanochannels are crucial for achieving excellent ion transport properties and enable versatile applications such as ion gating, biosensing, and energy conversion. Conical single nanochannels were fabricated in single-ion-track polyethylene terephthalate (PET) membranes using the ion-track-etching method. Leveraging the high programmability of deoxyribonucleic acid (DNA) strands, a series of DNA molecules were designed to functionalize the outer surface at the tip region (small opening) of the conical PET nanochannels. This approach enabled precise regulation of both spatial charge distribution and steric hindrance on the outer surface, enabling the investigation of ion transport properties under the dominance of outer surface charge effects across ions of different valences. In contrast to the low-valence K⁺, the high-valence cation Ru(NH₃)₆³⁺ exhibited far greater enhancement in ionic current rectification (ICR) within PET films functionalized with DNA of varying charge densities. We used COMSOL simulations to corroborate that higher-valence ions exert more pronounced effects on ion transport in conical nanochannels with greater outer surface charge density. Furthermore, it was confirmed that the tip region plays a critical role in modulating the ion transport properties of conical nanochannels, thereby validating outer surface functionalization as a rational and efficient strategy. Full article

Corrosion-induced cracking poses a significant threat to the longevity of reinforced concrete (RC) structures, yet precisely forecasting its advancement continues to be a considerable scientific obstacle. The principal shortcoming of current numerical models is their excessive simplification, frequently presuming totally saturated conditions and disregarding the dynamic interplay between environmental (hygro-thermal) variations and developing mesoscale damage. This study presents a thorough hygro-thermo-electro-chemo-mechanical (HTECM) phase-field model to fill this research need. The model uniquely combines dynamic unsaturated hygro-thermal transport with multi-ion reactive electrochemistry and meso-scale fracture mechanics. A rigorous comparison with published experimental data validates the model’s exceptional accuracy. The anticipated progression of fracture width exhibited remarkable concordance with experimental data, indicating a substantial enhancement in precision compared to uncoupled, saturated-state models. A key finding is the quantification of the damage-induced “transport-corrosion” positive feedback loop: initial corrosion-induced microcracks significantly expedite the transport of local moisture and corrosive agents, leading to nonlinear structural degradation. This work presents a high-fidelity numerical platform that enhances the understanding of linked deterioration in materials science and improves the durability design of reinforced concrete structures. Full article

Sodium-ion batteries (SIB) are gaining attention as a sustainable, cost-effective alternative to lithium-ion technology in electric vehicles (EVs), driven by concerns over lithium’s scarcity, high costs, and environmental impact. This study explores the feasibility of SIBs through a theoretical analysis of recent advancements in chemistry, materials, and electrochemical performance. It compares key factors such as energy density, charge cycles, safety, cost-effectiveness, and supply chain sustainability. While sodium-ion batteries currently offer lower energy density and shorter cycle life, they benefit from abundant raw materials and more sustainable production. Recent breakthroughs in electrode and electrolyte design show promise for improved efficiency and longevity. Sodium-ion technology is not yet a full replacement for Li-ion batteries but presents a viable option for low-cost EVs and stationary storage. Full article

Peptide drug development has emerged as a prominent area in pharmaceutical research due to its high specificity and therapeutic potential. However, their biological activity, stability, and bioavailability are significantly influenced by interactions with counter-ions, which electrostatically bind to charged residues on peptide surfaces. This review systematically examines the multifaceted roles of counter-ions in modulating peptide structure and function. Counter-ions are classified into organic/inorganic and anionic/cationic categories, with their selection critically impacting peptide solubility, conformational stability, and activity. Inorganic counter-ions could enhance structural integrity, while organic counter-ions could mitigate toxicity risks. Notably, counter-ions can induce secondary structural transitions, directly affecting biological efficacy. Furthermore, counter-ions play pivotal roles in drug delivery systems, including nanoemulsions, self-emulsifying formulations, and lipid-based nanoparticles, where hydrophobic ion pairing improves encapsulation efficiency and oral bioavailability. In chromatography, ion-pairing reagents optimize peptide separation but may compromise mass spectrometry compatibility. Emerging analytical techniques, such as capillary electrophoresis and liquid chromatography–tandem mass spectrometry (LC-MS/MS), enhance counter-ion detection precision, addressing challenges in pharmaceutical quality control. Despite advancements, gaps remain in understanding ion-specific binding mechanisms and long-term safety profiles. This review underscores the necessity of tailoring counter-ion selection to balance efficacy, stability, and biocompatibility. Future research should prioritize elucidating molecular interaction dynamics and developing safer, high-affinity counter-ions to overcome current limitations in peptide drug development. Full article

Biological recolonization after cleaning remains a major challenge for the conservation of stone cultural heritage. As recolonization can start within months to a few years following intervention, developing rapid, field-deployable diagnostic approaches is crucial to better monitor microbial reappearance and to assess treatment performance in real time. Traditional evaluation methods lack the capacity to take into consideration non-cultivable microorganisms or assess functional traits relevant to recolonization. To bypass this gap, we applied on-site direct Whole-Genome Sequencing (Oxford Nanopore^® MinION™ sequencer) coupled with colorimetric analysis to understand the microbiome, resistome, and metabolic traits of subaerial biofilms present in untreated and treated (recolonized) areas of stone statues at the “Largo da Porta Férrea” (Coimbra’s UNESCO World Heritage site). Colorimetric analysis (ΔE of 32–40 in recolonized vs. 19–43 in untreated areas) and genomic data pointed out that the applied treatment provided only a short-term effect (roughly 4–5 years), with a marked decline in fungi (1–2% vs. 7–18%), coupled with an increased recolonization mainly by Cyanobacteriota (circa 35–45%) and several stress-resistant Bacteria (globally ~95% of reads vs. 73–79% in controls). Antimicrobial resistance profiles significantly differed between sites, with treated areas showing distinct and unique resistance genes, and plasmids containing the blaTEM-116 gene, which can indicate potential adaptive shifts in the resistomes profiles after intervention. Metabolic pathways analysis revealed that untreated areas retained more complete nitrogen and sulfur cycling gene sets, whereas treated areas showed reduced biogeochemical gene contents, consistent with earlier-stage recolonization steps. Given the current recolonization detection and the ongoing biofilm formation, routine monitoring efforts (e.g., every 6 months) are recommended. Overall, this study demonstrates the first on-site genomic characterization of recolonization events on heritage stone, providing a practical prompt-warning tool for conservation monitoring and future biofilm management strategies. Full article

The development of durable and efficient catalysts capable of driving both hydrogen and oxygen evolution reactions is essential for advancing sustainable hydrogen production through overall water electrolysis. In this study, we developed a corrosion-mediated approach, where Ni ions originate from the self-corrosion of the nickel foam (NF) substrate, to construct Pt-modified NiFe layered double hydroxide (Pt-NiFeO_xH_y@NiFe-LDH) under ambient conditions. The obtained catalyst exhibits a hierarchical architecture with abundant defect sites, which favor the uniform distribution of Pt clusters and optimized electronic configuration. The Pt-NiFeO_xH_y@NiFe-LDH catalyst, constructed through the interaction between Pt sites and defective NiFe layered double hydroxide (NiFe-LDH), demonstrates remarkable hydrogen evolution reaction (HER) activity, delivering an overpotential as low as 29 mV at a current density of 10 mA·cm⁻² and exhibiting a small tafel slope of 34.23 mV·dec⁻¹ in 1 M KOH, together with excellent oxygen evolution reaction (OER) performance, requiring only 252 mV to reach 100 mA·cm⁻². Moreover, the catalyst demonstrates outstanding activity and durability in alkaline seawater, maintaining stable operation over long-term tests. The Pt-NiFeO_xH_y@NiFe-LDH electrode, when integrated into a two-electrode system, demonstrates operating voltages as low as 1.42 and 1.51 V for current densities of 10 and 100 mA·cm⁻², respectively, and retains outstanding stability under concentrated alkaline conditions (6 M KOH, 70 °C). Overall, this work establishes a scalable and economically viable pathway toward high-efficiency bifunctional electrocatalysts and deepens the understanding of Pt-LDH interfacial synergy in promoting water-splitting catalysis. Full article