Search Results (74)

Organic memristors are attractive building blocks for neuromorphic computing owing to their intrinsic synaptic functionalities and solution-processability. However, their operational instability remains a major challenge, primarily arising from poorly controlled semiconductor crystallization and stochastic conductive filament formation. Here, we report a high-performance solution-processed organic memristor based on a TIPS-pentacene/PMMA/CdSe-ZnS quantum-dot hybrid system, in which a dual-engineering strategy is employed to simultaneously regulate film crystallization and filament dynamics. Specifically, the PMMA matrix templates the molecular ordering of TIPS-pentacene to improve film uniformity and crystallinity, while CdSe/ZnS quantum dots locally modulate the electric field to direct and confine conductive filament formation. As a result, the device exhibits ultralow and highly uniform switching voltages (0.473 V for set and −0.430 V for reset), suppressed device-to-device variation, long retention exceeding 10⁴ s, and endurance over 1200 switching cycles. In addition, the memristor supports multilevel data storage and successfully emulates key synaptic functions, including long-term potentiation/depression, paired-pulse facilitation, and spike-timing-dependent plasticity. This work provides a materials-level strategy for achieving reliable and low-power organic memristors, offering a viable route toward high-density nonvolatile memory and neuromorphic computing hardware. Full article

The long-term stability of biodegradable polymer coatings deposited by matrix-assisted pulsed laser evaporation (MAPLE) remains insufficiently understood, particularly under ultraviolet irradiation conditions where photochemical effects may accompany material transfer. In this work, thin films of poly(lactide-co-caprolactone)-block-poly(ethyleneglycol)-block-poly(lactide-co-caprolactone), also known as PLCL-PEG-PLCL, are deposited from chloroform solutions by UV-MAPLE using a nanosecond Nd:YAG laser operating at 266 nm over a wide laser fluence range (0.25–0.9 J/cm²). The effect of laser fluence on the morphological, structural, and chemical evolution of the coatings is investigated by atomic force microscopy (AFM), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDS), focused ion beam scanning electron microscopy (FIB-SEM), and X-ray diffraction (XRD). At low laser fluence, relatively homogeneous coatings are obtained while largely preserving the characteristic functional groups of the triblock copolymer. Increasing the laser fluence progressively induces surface restructuring phenomena, including droplets, wrinkles, and the appearance of highly symmetric faceted structures. These entities develop preferentially in samples deposited at elevated fluence and frequently appear only after prolonged aging under ambient conditions, revealing delayed recrystallization behaviour associated with metastable species generated during the deposition process. EDS analyses reveal localized chlorine enrichment within the faceted structures, while FIB-SEM investigations show porous internal morphologies. XRD confirms that the polymer matrix remains predominantly amorphous. The combined observations suggest that UV-MAPLE deposition from chloroform involves not only physical material transfer but also photochemical processes that promote decomposition, recombination, and delayed crystallization phenomena. A phenomenological model describing the successive stages of surface evolution, aging, and recrystallization is proposed. These results provide new insight into the long-term evolution of laser-deposited biodegradable polymer coatings and highlight the importance of solvent selection and processing conditions in determining their stability. Full article

Cross-presentation of exogenous antigens by dendritic cells (DCs) relies on the cytosolic pathway, enabling proteasomal processing and subsequent loading of antigenic peptides onto major histocompatibility complex class I (MHC-I) molecules. Although this pathway is central to CD8⁺ T-cell activation, the molecular mechanisms that regulate intracellular antigen processing and redistribution during cross-presentation remain incompletely defined. In this study, we investigated the contribution of the large-pore channel Pannexin-1 (Panx1) to antigen handling during cross-presentation. Using confocal microscopy and quantitative image analysis in granulocyte–macrophage colony-stimulating factor/interleukin-4 (GM-CSF/IL-4)-derived inflammatory bone marrow-derived dendritic cell (BMDC)-like cellsexposed to ovalbumin (OVA)–Alexa Fluor 488, we observed time-dependent changes in intracellular antigen distribution that were altered upon pharmacological inhibition of Panx1 with the blocking peptide 10Panx1. In parallel, functional assays revealed that Panx1 inhibition significantly reduced SIINFEKL peptide-dependentactivation of B3Z CD8⁺ T-cell hybridomas following pulsing with full-length OVA. Similar effects were observed in the cross-presentation-competent MUTU1940 dendritic cell line. Importantly, Panx1 inhibition did not significantly affect dendritic-cell viability or LPS-induced activation under the experimental conditions tested. In contrast, pharmacological inhibition or genetic deficiency of P2X7 receptor (P2X7) did not produce comparable reductions in cross-presentation, and combined inhibition did not result in additive effects under the experimental conditions tested. Together, these findings provide functional evidence supporting a role for Panx1 in regulating intracellular antigen redistribution associated with cross-presentation. While not establishing direct genetic causality, our data identify Panx1 as a modulatory component influencing antigen-processing events that culminate in CD8⁺ T-cell activation, thereby expanding the current framework of intracellular antigen-processing mechanisms involved in dendritic-cell-mediated cross-presentation. Full article

Neuronal excitability manifests itself mainly in the form of non-linear, self-regenerative waves of electricity moving along the surface of neuronal axons. These waves are commonly known as action potentials (APs). Theoretical and experimental investigations of the physical and functional characteristics of APs have broadly followed along the lines of the ionic hypothesis and the associated mathematical model introduced by Hodgkin and Huxley (HH). In the current form of this bioelectrical framework, adopted in mainstream physiology and other biological sciences, the axonal membrane is conceptualized as an electronic circuit where electric current is generated and propelled as a result of the time-dependent opening and closure of voltage-operated ion channel proteins, allowing passive flow of specific ions across and along the membrane, powered by their respective electrochemical gradients. Although representing mainstream research, the bioelectric perspective has been criticized for its narrow focus on the electrical characteristics of APs, whilst ignoring other physical manifestations of the nerve signal, particularly mechanical and thermal changes coinciding with AP propagation. As an alternative, a macroscopic thermodynamics-based acoustic theory has been outlined, in which all electric and non-electric manifestations of the nerve signal are considered as a result of a single density pulse in the axonal membrane carried by a reversible lipid membrane phase transition and momentum conservation. Representing a minority view, however, this unified, acoustic perspective on the physical nature of neuronal excitability is largely ignored by representatives of the bioelectric perspective. Here, we draw special attention to the philosophical dimension of the communication failure between the two communities of scientists. We argue that adherents of the bioelectric perspective favor a mechanist type of explanation, whilst supporters of the acoustic perspective are committed to so-called covering-law types of explanation. We conclude that it is this thus far unrecognized philosophical rift, rather than specific scientific differences in opinion, that blocks fruitful interdisciplinary cooperation necessary for building a comprehensive, fully integrated notion of the physical nature of neuronal excitability. Suggestions of how to bridge this conceptual gap are formulated. Full article

In order to solve linear systems of Fredholm integral equations, this paper proposes a novel hybrid numerical method that combines improved block-pulse functions with Legendre polynomials. By utilizing the orthogonality and strong approximation properties of Legendre polynomials along with the computational simplicity of improved block-pulse functions, the suggested method converts the integral system into an equivalent system of algebraic equations. The approach outperforms a number of conventional numerical methods in terms of accuracy and convergence speed. The robustness, efficiency, and stability of the suggested scheme are validated by several numerical remarks, which also show how well it works for solving complex Fredholm integral systems that arise in scientific and engineering applications. Full article

Amyloid-β peptides (Aβ) are considered a main culprit of Alzheimer’s disease (AD), leading to synaptic dysfunction and memory deficits. Although studies in animal models of AD converge to show alterations of synaptic plasticity, namely of long-term potentiation (LTP), the mechanisms through which Aβ affects synaptic function remain to be unveiled. In this study, we established experimental conditions showing that the acute exposure of mouse hippocampal slices to optimized concentrations of Aβ impaired short-term (PPF-paired-pulse facilitation) and long-term (LTP-long-term potentiation) plasticity without altering basal synaptic transmission. We observed that the elimination of extracellular adenosine with adenosine deaminase abrogated the impact of Aβ on synaptic plasticity, showing a mandatory involvement of extracellular adenosine in the neurophysiological effects of Aβ. Additionally, inhibiting adenosine receptor function with caffeine, as well as selectively blocking adenosine A₁ receptors (A₁R) with DPCPX, or adenosine A_2A receptor (A_2AR) with either an antagonist SCH58261 or through knocking out A_2AR, demonstrated that acute Aβ modified mouse hippocampal PPF via A₁R and LTP through A_2AR. Furthermore, the use of slices from mice bearing forebrain-neuron A_2AR deletion, along with the application of α,β-methylene ADP, a CD73 inhibitor, confirmed that the neurophysiological actions of Aβ on hippocampal LTP occur selectively through the overfunction of neuronal A_2AR via CD73-mediated formation of extracellular adenosine. Overall, the exploitation of a neurophysiological model of early AD, based on the acute administration of Aβ to hippocampal slices, confirmed the critical involvement of adenosine signaling in the impact of Aβ on synaptic plasticity. Full article

Background/Objectives: Cervical facet joints are a common source of chronic neck pain, yet factors predicting treatment response to pulsed radiofrequency remain poorly defined. This study aimed to identify predictors of treatment success following ultrasound-guided cervical medial branch pulsed radiofrequency in patients with chronic cervical facet joint pain. Methods: This retrospective cohort study included 54 patients with chronic cervical facet joint pain who had positive response to diagnostic block. Pain intensity and functional disability were assessed at baseline and at 1-, 3-, and 6-months post-procedure, with treatment success defined as ≥50% pain reduction at 6 months. Results: The success rate was 35.2%, and multivariate logistic regression identified four independent predictors: presence of paraspinal tenderness on physical examination, shorter pain duration, lower baseline pain intensity, and lower baseline disability. Conclusions: These findings suggest that patients with localized facet joint pathology manifesting as paraspinal tenderness, shorter symptom duration, and lower baseline severity are most likely to benefit from this intervention, supporting early referral and careful clinical selection to optimize treatment outcomes. Full article

Optical synaptic transistors employing polymer dielectrics have emerged as promising building blocks for neuromorphic computing due to their low power consumption and rich photo-induced memory behaviors. While extensive experimental studies have demonstrated various synaptic functions, a unified physical understanding of the coupled charge trapping and ionic polarization processes governing device dynamics remains incomplete. In this work, we develop a unified physical model to investigate optical synaptic behaviors in polymer-based transistors with oxide interlayers. The model explicitly describes the time-dependent evolution of photo-induced charge trapping at the semiconductor–dielectric interface and ionic polarization within the polymer dielectric, which jointly modulate the effective threshold voltage of the transistor channel. Based on this framework, key synaptic functions including excitatory postsynaptic current (EPSC), paired-pulse facilitation (PPF), and pulse-dependent potentiation are quantitatively reproduced. The model further reveals how dielectric structure and trapping strength govern the transition between short-term and long-term plasticity. This study provides a physically intuitive and experimentally relevant modeling framework for understanding optical synaptic transistors, offering guidance for the rational design and optimization of polymer-based neuromorphic devices. Although simplified, the proposed model captures the essential physics governing optical synaptic behaviors and provides a general framework applicable to a wide class of ion–electronic neuromorphic devices. Experimental measurements are used as physically motivated proxies to validate the multi-timescale structure of the model rather than direct numerical fitting. Full article

Background/Objectives: Quadriceps arthrogenic muscle inhibition (AMI) represents a key impairment following anterior cruciate ligament reconstruction (ACLR), contributing to quadriceps weakness. Although transcutaneous electrical nerve stimulation (TENS) and percutaneous electrical nerve stimulation (PENS) have been primarily investigated for analgesia, their effects on quadriceps strength in the early postoperative period remain underexplored. Methods: This study describes a single-blinded, parallel-group randomized controlled trial investigating the short-term effects of a single high-frequency TENS session and a novel long-term potentiation (LTP) PENS protocol on quadriceps strength and related clinical outcomes after ACLR. Fifty-four participants will be randomly allocated using block randomization in a 1:1:1 ratio to one of three groups: a control group (conventional post-ACLR rehabilitation only), a TENS group (conventional rehabilitation plus a single high-frequency TENS session), or a PENS group (conventional rehabilitation plus a single LTP PENS session). Participants will receive neuromodulatory intervention during the sixth postoperative week. The LTP PENS protocol consists of five 5 s stimulation bursts at 100 Hz and 250 μs pulse width and has only been investigated once in patients with upper limb pathology, underscoring its novelty in a postoperative setting. Results: The primary outcome is quadriceps maximal voluntary isometric contraction, selected as a clinically relevant surrogate of quadriceps activation deficits associated with AMI. Secondary outcomes include pain intensity, pressure pain threshold, knee range of motion, thigh muscle perimeter, knee effusion and swelling, and self-reported function and knee-related quality of life. Outcomes will be assessed at baseline, immediately post-treatment, and 1 and 7 days post-intervention by a blinded assessor. Full article

The construction industry is increasingly oriented toward the development of sustainable materials aimed at reducing environmental impact while ensuring adequate mechanical and hygrothermal performance. This study investigates the effect of two distinct forms of waste tire particles—powder (UTWP) and granulate (UTWG)—separately incorporated into lime-stabilized adobe blocks at respective contents of 5–25% and 10–60%. The physical, thermal, mechanical, and microstructural properties of the blocks were evaluated through density measurements, ultrasonic pulse velocity, water absorption, thermal conductivity, mechanical strength tests, and microstructural characterization using SEM-EDX. The results show that the incorporation of powdered waste tires (UTWP) significantly enhances thermal, hygroscopic, and microstructural performance; thermal conductivity decreases by up to 21.6%, and a 40% reduction in capillary water absorption is achieved with only 5% DPUP, indicating improved insulation and increased resistance to moisture. In contrast, granular waste tires (UTWG) induce a notable increase in ductility and acoustic absorption at the expense of a more pronounced reduction in mechanical strength. The observed improvements in water resistance, microstructural stability, and ductile behavior impart a resilient character to the material, making it particularly suitable for arid environments. Overall, adobe modified with optimized fractions of waste tire particles emerges as a sustainable and multifunctional construction material that promotes waste valorization while enhancing the functional performance of earthen architecture. Full article

We present a mixed-signal front-end ASIC designed for compact Silicon Photomultiplier (SiPM) sensor interfaces, implemented in the AMS 0.35 µm CMOS technology. The chip integrates two independent analog channels, each composed of five custom second-generation current conveyors (CCII⁺), a fast zero-crossing discriminator, and a peak-and-hold stage based on a tailored operational amplifier. The CCII⁺ and discriminator blocks were designed in-house, based on literature designs and adapted to the technology to ensure low input impedance and fast current-mode signal propagation. This architecture enables precise detection of small signals with reduced pile-up, important for time-resolved photon detection. Bias and threshold control are provided by programmable current mirrors and SPI-configurable DACs, including a 10-bit current-mode DAC based on a current-splitting structure with approximately 200 nA resolution. A custom SiPM behavioral model was developed in the Cadence environment to support design and simulation, reproducing realistic pulse shapes and recovery dynamics for timing applications. Circuit-level simulations confirm correct analog functionality and stable operation across the intended dynamic range, with a per-channel consumption of about 5.9 mA at 3.3 V (19.5 mW), reflecting a tradeoff between speed and robustness. The system is compatible with external timing architectures, while internal CCII⁺ stages ensure low-impedance current reception, fast discrimination, and accurate current-to-voltage conversion for peak detection. Full article

Sesame seed oil is a bioactive-rich lipid source, notable for lignans, tocopherols, and unsaturated fatty acids that underpin its antioxidant and cardioprotective properties. This study optimized two innovative, non-thermal extraction techniques—pulsed electric field (PEF) and ultrasound bath-assisted extraction (UBAE)—to maximize yield and preserve oil quality for functional food applications. A blocked definitive screening design combined with response surface methodology modeled the effects of energy power (X₁, 60–100%), liquid-to-solid ratio (X₂, 10–20 mL/g), and extraction time (X₃, 10–30 min) on fat content, DPPH antiradical activity, and oxidative stability indices (Conjugated Dienes, CDs/Conjugated Trienes, CTs). UBAE achieved the highest fat yield—59.0% at low energy (60%), high X₂ (20 mL/g), and short X₃ (10 min)—while PEF maximized DPPH to 36.0 μmol TEAC/kg oil at high energy (100%), moderate X₂ (17 mL/g), and short X₃ (10 min). CDs were minimized to 19.78 mmol/kg (UBAE, 60%, 10 mL/g, 10 min) and CTs to 3.34 mmol/kg (UBAE, 60%, 12 mL/g, 10 min). Partial least squares analysis identified X₂ and X₃ as the most influential variables (VIP > 0.8), with energy–time interplay (X₁ × X₃) being critical for antioxidant capacity. Compared to cold-pressing and Soxhlet extraction, PEF and cold-pressing retained higher antioxidant activity (~19 μmol TEAC/kg) and oxidative stability (TBARS ≤ 0.30 mmol MDAE/kg), while Soxhlet—though yielding 55.65% fat—showed the poorest quality profile (Totox value > 560). Both non-thermal techniques can deliver bioactive-rich sesame oil with lower oxidative degradation, supporting their application in functional foods aimed at improving dietary antioxidant intake and mitigating lipid oxidation burden. PEF at high energy/short time and UBAE at low energy/short time present complementary, scalable options for producing high-value edible oils aligned with human health priorities. As a limitation, we did not directly quantify lignans or tocopherols in this study, and future work will address their measurement and bioaccessibility. Full article

Background and Objectives: Chronic migraines are a disabling neurological disorder with limited response to preventive pharmacological treatments. Greater occipital nerve (GON)-targeted radiofrequency (RF) procedures have emerged as promising interventions, yet long-term comparative data between pulsed RF (PRF) and continuous-lesion RF (LesionRF) remain scarce. This study evaluated the 12-month efficacy and safety of PRF versus LesionRF. Materials and Methods: A single-center cohort of 211 patients with chronic migraine diagnosed by ICHD-3 criteria (PRF = 107; LesionRF = 104) was analyzed. All patients had a positive diagnostic block and ≥12 months of follow-up. Interventions were performed under ultrasound guidance with standardized protocols (PRF: 42 °C, 4 min, 45 V; LesionRF: 80 °C, 90 s). The primary outcome was a change in monthly migraine days (MMD), while secondary outcomes included responder rates (≥50% MMD reduction), pain intensity (VAS), functional outcomes (HIT-6, MIDAS), quality of life (SF-36, EQ-5D), medication use, retreatment, and complications. Results: Both groups improved, but LesionRF showed greater benefit. At 12 months, LesionRF achieved a larger MMD reduction (−4.8 days vs. PRF, p < 0.001), higher responder rates (83% vs. 65%, p = 0.01), and greater VAS decreases (−1.6, p < 0.001). Functional and quality-of-life scores improved more with LesionRF, with MIDAS reductions surpassing MCID and responder rates meeting PASS. Retreatment was less frequent with LesionRF (8% vs. 19%; HR 2.15, p = 0.037), and two LesionRF patients (1.9%) developed hematomas that resolved conservatively. Conclusions: Compared with PRF, LesionRF provided more sustained and clinically meaningful benefits for chronic migraines. Both approaches appeared to be safe, though confirmation in larger randomized trials is warranted. Full article

Poplar (Populus L. species), a fast-growing temperate species, forms plantations with high productivity and biomass, with its litter sustaining key functions in nutrient cycling, microbial diversity, and carbon storage. Litter microbial communities drive decomposition, particularly in early stages, this initial phase is characterized by the leaching of water-soluble carbon and nutrients from the litter, which creates a readily available resource pulse that facilitates rapid microbial colonization and activation. This process is followed by the activation of microbial enzymes and the immobilization of nutrients, collectively initiating the breakdown of more recalcitrant litter materials. Under rising global nitrogen deposition, we conducted a field randomized block experiment in 13-year-old pure poplar (Populus deltoides L. ‘35’) stands, with three nitrogen addition treatments: N0 (0 g N·m⁻²·yr⁻¹), N2 (10 g N·m⁻²·yr⁻¹), and N4 (30 g N·m⁻²·yr⁻¹). In the initial phase of litter decomposition, we measured the soil properties and litter traits, the litter microbial community composition, and its taxonomic and phylogenetic diversity indices. The results indicate that nitrogen addition altered microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), soil NO₃⁻-N, and accelerated litter decomposition rates. The microbial community in leaf litter responded to nitrogen addition with increased phylogenetic clustering (higher OTU richness and NRI), which suggests that environmental filtering exerted a homogenizing selective pressure linked to both soil and litter properties, whereas the microbial community in branch litter responded to nitrogen addition with increased taxonomic diversity (higher OTU richness, Shannon, ACE, and Chao1), a pattern associated with litter properties that likely alleviated nitrogen limitation and created opportunities for more taxa to coexist. The observed differences in response stem from distinct substrate properties of the litter. This study elucidates microbial taxonomic and phylogenetic diversity responses to nitrogen addition during litter decomposition, offering a scientific foundation for precise microbial community regulation and sustainable litter management. Full article

Neuropathic pain presents a persistent therapeutic challenge, arising from diverse etiologies such as trigeminal neuralgia, postherpetic neuralgia, post-amputation pain, painful polyneuropathy, peripheral nerve injury pain, and painful radiculopathy. Given the limitations and side effects associated with pharmacologic treatments, interest in interventional therapies has surged. Herein, ultrasound guidance provides real-time, radiation-free visualization that enhances procedural accuracy and safety. This narrative review synthesizes current evidence on ultrasound-guided techniques—including nerve blocks, pulsed radiofrequency, hydrodissection, and peripheral nerve stimulation—in the management of neuropathic pain. These minimally invasive approaches demonstrate potential in providing significant and durable pain relief, enhancing functional outcomes, and reducing reliance on systemic medications. Notably, much of the existing literature comprises small-scale or observational studies and larger randomized controlled trials are therefore essential to confirm efficacy, define optimal treatment parameters, and inform clinical guidelines for broader adoption. Full article