Search Results (664)

Peripheral nerve injuries involving critical-sized gaps remain a major clinical challenge. Although autologous nerve grafting is considered the gold standard for peripheral nerve repair, its clinical application is limited by the availability of donor nerve tissue and the risk of donor-site morbidity, including sensory deficits and functional impairment. Therefore, nerve guidance conduits (NGCs) have emerged as a promising alternative when combined with bioactive modulation strategies. In this study, we evaluated bisvinyl sulfonemethyl (BVSM)-crosslinked gelatin conduits integrated with electrical stimulation (ES) at different frequencies (0, 2, 20, and 200 Hz) in a rat sciatic nerve defect model over a 4-week recovery period (n = 10 per group). Structural regeneration was assessed by morphometric analysis, electrophysiology, macrophage infiltration, CGRP immunoreactivity, retrograde Fluorogold tracing, quantitative PCR of growth factors and inflammatory cytokines, and behavioral testing. Among all stimulation paradigms, low-frequency ES at 2 Hz produced the most pronounced regenerative effects. The 2 Hz group demonstrated significantly greater axon number, axonal density, and regenerated nerve area compared with control and high-frequency groups (p < 0.05). Electrophysiological assessments revealed improved nerve conduction velocity, higher MAP amplitudes, and shorter latencies. Enhanced macrophage recruitment and elevated CGRP expression were observed, suggesting coordinated neuroimmune and neurochemical activation. Gene expression analysis indicated upregulation of neurotrophic factors and balanced inflammatory cytokine responses under low-frequency stimulation. In contrast, high-frequency stimulation (200 Hz) failed to enhance overall regeneration and showed reduced axonal metrics, suggesting possible overstimulation-associated suppression. Collectively, these findings demonstrate that BVSM-crosslinked conduits provide a stable and biocompatible regenerative scaffold, and that appropriately tuned low-frequency electrical stimulation (2 Hz) optimally enhances structural, molecular, and functional recovery. The integration of material engineering with bioelectrical modulation represents a promising strategy for next-generation bioelectronic interfaces in peripheral nerve repair. Full article

The residual sub-millimeter metal particles in gas-insulated metal enclosed switchgear (GIS) and gas-insulated transmission lines (GILs) are significant factors that trigger insulation failures. During actual operation, these particles not only endure the action of alternating electric fields but also are continuously stimulated by mechanical vibrations. Current research mostly focuses on the behavior of millimeter-sized particles under a single physical field, lacking in-depth understanding of the jumping characteristics of sub-millimeter-scale particles under the combined action of alternating electric fields and mechanical vibrations. This paper has built a collaborative action test platform and constructed a spherical-bowl-shaped electrode defect model. It systematically studied the jumping behavior, motion evolution, and local discharge characteristics of 20-mesh and 40-mesh irregular aluminum particles under the combined action of different voltages (0–7 kV) and mechanical vibrations (amplitude 0.01–0.1 mm, frequency 10–100 Hz). The results show that mechanical vibrations provide initial kinetic energy for the particles, significantly reducing the threshold for jumping, and are the key initiating factor in the collaborative action; in the low-voltage stage, vibration dominates the jumping behavior, while in the high-voltage stage, the electric field dominates the motion evolution; and under dual stimulation, the jumping area of the particles is wider and the motion forms are more diverse (such as flying-flying motion, vertical state, pile-up excitation, etc.), and the starting voltage of discharge is significantly reduced, the discharge repetition rate increases with the increase in vibration intensity and voltage, and is closely related to the particle size. This paper reveals the uniqueness of particle motion and discharge under the collaborative action, providing a theoretical basis for the assessment of multi-physical field states and fault prediction of GIS/GIL. Full article

Background: We synthesized evidence from randomized clinical trials (RCTs) published between 2019 and 2025 on repetitive transcranial magnetic stimulation (rTMS) in post-stroke cognitive impairment (PSCI) and compared different stimulation parameters, cortical targets, and combinations with rehabilitation interventions. Methods: A systematic review according to PRISMA guidelines examined the RCTs applying rTMS in adults with PSCI compared with control or sham groups. The primary outcome was improvement in cognitive function and functional outcomes measured with standardized scales. Results: Fifteen studies, involving a total of 732 patients, were included. The most frequently investigated were high-frequency (≥10 Hz) stimulation protocols of the left dorsolateral prefrontal cortex, with treatment cycles ranging from 2 to 6 weeks. Overall, rTMS was generally safe and well tolerated, with rare and mild adverse events. Several studies reported improvements in cognitive performance following rTMS, although effects were variable across trials and need caution in light of heterogeneity in stimulation protocols, sample sizes, outcome measures, and methodological quality. In most cases, rTMS or intermittent theta burst stimulation combined with structured cognitive training yielded greater cognitive and functional gains than stimulation or rehabilitation alone. This suggests a positive interaction between rTMS and cognitive training, although current evidence does not yet allow definitive conclusions. Conclusions: rTMS appears to be a promising strategy for post-stroke cognitive rehabilitation, particularly for attention and executive functioning. However, heterogeneity in stimulation protocols and outcome measures, along with limited sample sizes and short follow-up, reduces the certainty and comparability of current evidence. The widespread reliance on global screening tools may further underestimate domain-specific effects. Future multicentre trials with standardized protocols and more sensitive cognitive assessments are needed to clarify efficacy and guide further clinical application of rTMS in PSCI. Full article

Optogenetic modulation employs light-sensitive proteins known as opsins to regulate cellular activity. A unique therapeutic application of this technique involves modulating pain perception by selectively targeting neural pathways within the spinal cord. Multi-Characteristic Opsin (MCO) represents an innovative optogenetic actuator capable of activation across a broad spectrum of light wavelengths, exhibiting a slow depolarizing phase that resembles natural photoreceptors. This study examines the current advancements in spinal optogenetic modulation utilizing MCO for pain management. Due to its high sensitivity, MCO facilitates minimally invasive, remotely controlled optogenetic modulation of spinal neurons. This approach enables the regulation of extensive spatial regions, provided the MCO channel receives sufficient light intensity to surpass the activation threshold. Nano-enhanced optical delivery (NOD) successfully transfected spinal neurons with the GAD67-MCO2-mCherry construct, as confirmed by membrane-localized mCherry fluorescence with DAPI-labeled nuclei. Using this platform, 5 Hz spinal optogenetic stimulation produced a significant reduction in formalin-evoked pain behaviors, demonstrating frequency-specific modulation of spinal pain circuits. Neither 2 Hz nor 10 Hz stimulation yielded comparable analgesic effects, underscoring the importance of precise stimulation parameters. The therapeutic impact also depended on transfection efficiency: reducing the fGNR–plasmid concentration diminished MCO expression and weakened the analgesic response. Together, these results show that effective spinal optogenetic pain modulation requires both optimal stimulation frequency and robust gene delivery. Full article

In the present study, room temperature (RTR) and cryogenic (CR) rolling of electrolytic tough pitch copper (ETP-Cu) was performed to elucidate how deformation temperature and reduction ratio (40% and 80% thickness reductions) control dislocation storage, local stored energy (SE), and self-annealing. Correlated SEM/EDS and EBSD analyses were used to (i) locate Cu₂O particles, (ii) quantify local misorientation, and (iii) map the SE for self-annealing. Point EDS confirms that the intermetallic particles are copper oxides (Cu₂O), with apparent O content varying with particle size and EDS interaction volume. RTR80 (80% rolled) exhibits systematically higher KAM values and a larger area fraction of high SE than RTR40 (40% rolled), explaining the greater frequency and spatial density of self-annealed grains at higher reduction. Cryogenic rolling produces more severe fragmentation and a higher fraction of subgrains than RTR at equivalent reductions. CR80 shows the high KAM structures and locally highest SE regions among all conditions, and a higher fraction of self-annealed grains. Nevertheless, the mapped average SE for CR80 (2.93 × 10⁶ J/m³) was lower than for RTR80 (3.34 × 10⁶ J/m³) due to rapid post-deformation dislocation annihilation/self-annealing upon warming at RT. In all conditions, Cu₂O particles and bulged/irregular grain boundaries concentrate dislocations and SE and act as dominant particle-stimulated nucleation (PSN) sites and RT recrystallization, respectively. These results demonstrate that deformation temperature and reduction jointly determine the spatial distribution of SE and hence the propensity for self-annealing in ETP Cu. Full article

The fundamental differences between high- and low-frequency ultrasound for medical purposes were demonstrated. A model describing the effect of ultrasound on erythrocyte aggregation was developed, and the rapid movement of erythrocytes toward the nodes of a standing acoustic wave was demonstrated, with its velocity compared to the rate of erythrocyte dissociation under the influence of shear forces. The t-test was used to assess the statistical significance of differences between two blood samples and confirmed the effect of low-frequency ultrasound intensity on erythrocyte aggregation. The study employed a patented low-frequency ultrasound transducer generating a traveling acoustic wave that produces shear forces capable of disrupting erythrocyte aggregates into individual erythrocytes. Since the developed technique is intended for human therapy, it is assumed that the proposed low-frequency ultrasound parameters are safe for flowing blood. Due to deeper and more precise penetration of the acoustic signal into tissues, this ultrasound transducer may be promising for improving microcirculation and alleviating patient condition without medication, as well as for reducing blood pressure and heart rate. The developed technique also enables more effective disruption of heart valve plaques and shows therapeutic potential for tumor treatment and in vivo drug encapsulation. Since erythrocytes in diabetic patients are stiffer than those in healthy individuals, their passage through capillaries is more difficult. Therefore, the developed and patented ultrasound-based sole stimulation technique may produce a positive physiological effect by stimulating blood flow in the capillaries of patients with foot ulcers. Full article

Introduction: Caffeine is the most widely consumed psychoactive stimulant worldwide and acts primarily through antagonism of adenosine A1 and A2A receptors, thereby reducing sleep pressure and promoting wakefulness. Although its alerting and performance-enhancing effects are well established, its influence on sleep-related electroencephalography (EEG) has been investigated across diverse paradigms with substantial methodological heterogeneity. This systematic and mechanistic review aimed to synthesize human evidence on how caffeine affects sleep architecture, quantitative sleep EEG, and neurophysiological markers of sleep homeostasis, and to interpret these findings within current models of adenosine-mediated sleep–wake regulation. Materials and Methods: A systematic search of PubMed/MEDLINE, Web of Science, Scopus, Embase, PsycINFO, ResearchGate, and Google Scholar was conducted for studies published between January 1980 and January 2026, with the final search performed on 10 January 2026. Eligible studies were original human investigations examining caffeine exposure or administration and reporting sleep-related EEG outcomes, including polysomnographic sleep staging, spectral EEG analyses, or other EEG-derived sleep metrics. Two reviewers independently screened records and assessed eligibility, with disagreements resolved by consensus. Data on study design, participant characteristics, caffeine interventions, EEG methodology, and outcomes were extracted using a predefined form. Risk of bias was evaluated using the RoB 2 and ROBINS-I tools. Owing to marked heterogeneity across studies, findings were synthesized narratively within a mechanistic interpretive framework. Results: Thirty-two studies were included. Across highly heterogeneous paradigms—including acute bedtime or evening dosing, daytime or repeated caffeine use before nocturnal sleep, administration during prolonged wakefulness followed by recovery sleep, withdrawal protocols, and ambulatory/home EEG monitoring—the most consistent finding was suppression of low-frequency NREM EEG activity, particularly slow-wave activity and the lowest delta frequencies. Caffeine frequently increased faster EEG activity, including sigma/spindle and beta ranges, producing a lighter, more aroused, and more wake-like sleep EEG profile. These effects were especially prominent during early-night NREM sleep and in recovery sleep after sleep deprivation, where caffeine attenuated the expected homeostatic rebound in low-frequency power. REM-related effects were less consistent, but some studies reported delayed REM timing and subtler alterations in REM EEG. Emerging evidence further suggests that caffeine increases EEG complexity and shifts sleep dynamics toward a more excitation-dominant state. Several studies indicated that quantitative EEG measures were more sensitive than conventional sleep-stage variables in detecting caffeine-related sleep disruption. Dose, timing, habitual caffeine use, withdrawal state, age, circadian context, and adenosinergic genetic variation, particularly involving ADORA2A, moderated the magnitude of effects. We also highlighted the connection between current results and sports and sports science. Conclusions: Caffeine reliably alters the neurophysiological architecture of human sleep in a direction consistent with reduced sleep depth and weakened homeostatic recovery. The overall evidence supports a mechanistic model centered on adenosine receptor antagonism, attenuation of sleep-pressure build-up and expression, and a shift toward greater cortical arousal during sleep. Sleep EEG appears to be a sensitive marker of these effects, often revealing physiological disruption even when conventional sleep architecture changes are modest. Future research should prioritize larger and more diverse samples, pharmacokinetic and pharmacogenetic characterization, and ecologically valid high-resolution sleep monitoring to clarify the real-world and functional consequences of caffeine-induced EEG changes. Full article

Background: Restless legs syndrome (RLS) is a prevalent neurological sleep disorder that often impairs sleep maintenance. This single-arm, open-label study evaluated the efficacy, safety, and tolerability of extended-duration tonic motor activation (XD-TOMAC) in adults with RLS who experience frequent awakenings with symptoms. Methods: The study comprised three stages: Stage 1 (2 weeks of no intervention), Stage 2 (8 weeks XD-TOMAC), and Stage 3 (2 weeks of no intervention). XD-TOMAC consisted of bilateral high-frequency peroneal nerve stimulation programmed to 180 min duration and administered nightly at bedtime. Nineteen adults with moderate–severe RLS were enrolled, each reporting at least three nights per week of RLS symptoms causing increased awakenings or interfering with returning to sleep after waking. Results: The intent-to-treat analysis population included all patients who began Stage 2 (n = 15). After 8 weeks of XD-TOMAC, the mean change in International RLS Study Group Rating Scale (IRLS) score was −10.6 points (p < 0.001), and the mean change in Medical Outcomes Study Sleep Problems Index II (MOS-II) was −29.5 points (p < 0.001). The mean change in the number of nocturnal awakenings was −1.1 per night (p = 0.009), and the mean change in sleep efficiency was +8.5% (p = 0.001). The mean change in time awake with RLS symptoms after sleep onset was −28.1 min (p = 0.009). Each of these improvements was sustained at the end of Stage 3 (p < 0.01). There were no serious or severe device-related adverse events. Conclusions: Compared with prior 30 min TOMAC studies, XD-TOMAC demonstrated greater efficacy and similar tolerability, supporting its potential as a nonpharmacological therapy for RLS patients whose symptoms frequently disrupt sleep. Full article

Background and Objectives: Parkinson’s disease (PD) is a neurodegenerative disorder marked by bradykinesia, rigidity, and tremor. While deep brain stimulation (DBS) of the subthalamic nucleus (STN) and globus pallidus internus (GPi) effectively alleviates motor symptoms, the potential of targeting the substantia nigra pars reticulata (SNr) is less understood. This study investigates the effects of mid-term DBS of the SNr on motor function and neuroplasticity in a 6-hydroxydopamine (6-OHDA) rat model of PD. Methods: Adult male Sprague-Dawley rats (280–300 g) were divided into healthy control (n = 10), PD (n = 9), sham-DBS (n = 7), and SNr-DBS (n = 7) groups. Bilateral striatal 6-OHDA lesions induced PD. High-frequency (130 Hz, 60 µs) SNr-DBS was delivered for 14 days. Locomotor activity (open-field), gait (footprint method), and motor coordination (rotarod) were assessed. Tyrosine hydroxylase (TH) expression in the SN and c-Fos and BDNF expression in the cerebellum, prefrontal cortex (PFC), and ventrolateral thalamus were analyzed histologically. Results: SNr-DBS significantly improved ambulation and horizontal activity compared to the PD group (p < 0.05). Gait analysis showed significant improvements in forelimb/hindlimb stride length and stance width, while rotarod performance indicated enhanced motor coordination (p < 0.05). Histology revealed increased TH expression in the SN and elevated c-Fos and BDNF levels in the cerebellum, PFC, and thalamus in the SNr-DBS group vs. PD rats (p < 0.05). Conclusions: Mid-term SNr-DBS produced significant functional gains in motor activity and coordination in a 6-OHDA PD model, together with molecular evidence of dopaminergic enhancement and neuroplastic activation. These translational findings suggest that targeting the SNr may offer a clinically relevant alternative for patients with PD, particularly for those who may not optimally respond to conventional STN or GPi stimulation. Full article

A brain–computer interface (BCI) enables direct communication between the brain and external devices by translating neural activity into executable control commands. Among electroencephalography (EEG)-based paradigms, steady-state visual evoked potential (SSVEP) is widely adopted due to its high signal-to-noise ratio, robustness, and minimal calibration requirements. While SSVEP-based spellers have been extensively investigated, many existing systems rely on high-channel-density EEG recordings and computationally complex processing pipelines, and are primarily designed for alphabetic input structures. In this study, we present an SSVEP-based Korean speller that integrates the Cheonjiin keyboard layout to support intuitive composition of Hangul syllables. The proposed system adopts a simple configuration, employing only five visual stimulation frequencies (6.67–12 Hz) and two occipital EEG channels (O1 and O2), with real-time frequency recognition performed using canonical correlation analysis (CCA) within a 1.5 s sliding window. EEG signals were acquired at 200 Hz using an OpenBCI Ganglion board, band-pass filtered (5–45 Hz), and processed with harmonic sinusoidal reference templates for multi-frequency classification. The proposed interface generates five control commands (up, down, left, right, and select), enabling directional cursor navigation and character confirmation on a 4 × 4 virtual Cheonjiin keyboard. Experimental validation with three healthy participants demonstrated an average classification accuracy of approximately 82% and an information transfer rate (ITR) of 31.2 bits/min. Frequency-domain analysis revealed clear spectral peaks at the stimulation frequencies and their harmonics, indicating reliable SSVEP responses. The proposed system employs a simple two-channel configuration integrated with a Korean language-specific input structure, demonstrating that reliable SSVEP-based communication can be realized without computationally intensive algorithms or high-cost EEG acquisition systems. These findings demonstrate that reliable SSVEP-based communication can be achieved using a low-channel configuration without reliance on high-cost EEG equipment. Full article

Objective: The classic excitation/inhibition dichotomy may be insufficient to describe rTMS mechanisms in the aging brain. This study investigated immediate whole-brain resting-state functional connectivity effects of 10 Hz (high-frequency) and 1 Hz (low-frequency) rTMS over the left dorsolateral prefrontal cortex (DLPFC) in healthy older adults. Methods: Thirty healthy older adults (aged 60–75 years) participated in a randomized, single-blind, crossover study, and underwent 20-min 10 Hz and 1 Hz rTMS in separate visits. A 106-channel fNIRS system was used to record resting-state activity before and immediately after each intervention. Functional connectivity was analyzed at the channel, region-of-interest (ROI) and network summary levels, including graph-theoretic metrics and distance-stratified connectivity summaries. Results: At the network summary level, 10 Hz stimulation was associated with relatively more positive changes in global topology and spatially distributed connectivity summaries, whereas 1 Hz stimulation showed the opposite overall trend. In the graph-theoretic analyses, stimulation frequency × time interaction effects were observed for global efficiency, local efficiency, clustering coefficient, and mean node strength. At the edge level, only a small number of effects survived FDR correction, and the broader connection-wise patterns were therefore interpreted as exploratory. Uncorrected analyses suggested widespread enhancement after 10 Hz stimulation and widespread reduction after 1 Hz stimulation, together with localized paradoxical effects, including selective decreases after 10 Hz and selective increases after 1 Hz (e.g., bilateral primary motor cortex connectivity). Conclusions: These findings suggest that 10 Hz and 1 Hz rTMS over the left DLPFC are associated with different patterns of immediate whole-brain network reconfiguration in healthy older adults. The presence of localized paradoxical effects further suggests that rTMS responses in the aging brain may involve more complex forms of reorganization than a simple excitatory/inhibitory dichotomy would predict. Significance: The present study provides preliminary support for a network-level perspective on neuromodulation in older adults and highlights the value of whole-brain fNIRS for characterizing distributed responses to rTMS. Larger, sham-controlled, behavior-linked, and longitudinal studies are needed to determine the robustness and functional significance of these effects. Full article

Selectively modulating specific brain-rhythm bands with physical stimuli helps both to reveal neural mechanisms and to provide non-pharmacological treatment avenues for brain disorders. This study proposes and implements a multi-channel transcranial magneto-acoustic stimulation driving system based on amplitude-modulated (AM) sine waves (AM-TMAS) intended to supply a reliable hardware platform for noninvasive, focal low-frequency rhythmic electrical stimulation of deep-brain structures. The driving system implements a 64-channel AM module based on an FPGA plus high-speed DACs. Multi-channel precision is achieved via a unified high-speed clock and a global UPDATE trigger. To overcome the large separation between envelope and carrier frequencies, we developed a high-fidelity AM waveform generation method based on DDS + LUT + envelope multiplication. The algorithm first centers the carrier samples to preserve waveform symmetry, then applies LUT-based envelope coefficients and fixed-point envelope multiplication, enabling high-precision AM outputs with carrier frequencies from 100 kHz to 2 MHz and envelope frequencies from 0.1 Hz to 100 kHz. We tested the system’s rhythmic multi-channel AM output performance across frequencies and also measured magneto-acoustic-coupled rhythmic electrical signals produced by the AM-TMAS driving setup. Any single channel reliably produced high-fidelity AM waveforms with a 500 kHz carrier and 8 Hz/40 Hz envelopes; the measured carrier was 499.998 kHz with excellent frequency stability. Both envelope and carrier frequencies are flexibly tunable. At the nominal 500 kHz carrier, envelope fidelity was further quantified: the extracted envelopes achieved NRMSEs of 1.0795% (8 Hz) and 1.9212% (40 Hz), confirming high-fidelity AM synthesis. Under a 0.3 T static magnetic field, the AM-TMAS driving system generated rhythmic electrical responses in physiological saline that carried the expected 40 Hz envelope. The proposed AM-TMAS driver achieves high accuracy in AM waveform generation and robust multi-channel performance, and—when combined with an external static magnetic field—can produce rhythmically modulated magneto-acoustic electrical stimulation. This platform provides a practical technical tool for brain-function research and the development of rhythm-targeted neuromodulation therapies. Full article

Cochlear implantation (CI) effectively restores hearing across the whole lifespan but may be followed by vestibular complaints, especially in adult recipients. The aim of this narrative review is to provide a comprehensive characterization of vestibular complaints after CI in adults, collecting clinical and instrumental data, as well as discussing the risk factors for their development. From data reported in the literature, we defined five recurring clinical presentations of postoperative vestibular disturbances (phenotypes): acute postoperative vestibular syndrome, benign paroxysmal positional vertigo (BPPV), delayed Ménière-like vertigo attributable to secondary endolymphatic hydrops, chronic postoperative disequilibrium, and stimulation-linked vertigo. According to the different pathogeneses underlying each presentation, the management of postoperative vestibular complaints should be phenotype-guided, including short-course vestibular suppressants and early mobilisation for acute presentations; canalith repositioning for BPPV; empiric therapy for hydropic-like episodes; and vestibular rehabilitation when imbalance is persistent, programming changes for stimulation-linked symptoms. Alongside this phenotype-driven approach, subjective symptoms are common across cohorts but are usually transient and persistent disability is uncommon. Furthermore, instrumental data across the studies indicate that objective abnormalities cluster in otolith and low-frequency canal measures: Cervical, ocular VEMP, and caloric responses are more often impaired than high-frequency canal function on vHIT, confirming histopathological studies showing preferential saccular involvement during the insertion of the electrode array. The risk of postoperative vestibular complaints not only appears to be modulated more by patient-related factors, especially pre-existing vestibular loss, but also by the aetiology of deafness, or age, rather than by device characteristics; atraumatic surgical approaches may further reduce this risk. This review emphasizes that future research on vestibular complaints after CI should adopt standardized phenotypes when evaluating symptoms, objective vestibular function, falls, and quality of life. Additionally, it should correlate these outcomes with hypothetical risk factors and detailed surgical reports. Full article

The mixed lymphocyte reaction (MLR) is a classic functional assay that models in vitro interactions between responder T cells and allogeneic antigen-presenting cells (APCs). It quantifies the magnitude and quality of alloreactivity, integrating signals from allorecognition, co-stimulation, inflammatory context, and minor histocompatibility antigens that may not be captured by molecular matching alone. This review is narrative in nature and is intended as a practical, non-systematic synthesis of the field. To provide a modern, practice-oriented synthesis of MLR designs, readouts, and translational uses, highlighting how new technologies have expanded MLR from bulk proliferation into multidimensional immune profiling.We summarize why MLR remains valuable as a functional compatibility probe beyond HLA typing, including the high baseline frequency of alloreactive T cells that produces robust signals without priming. We then review key design options (one-way vs. two-way formats; stimulator inactivation; responder definition; APC source and maturation) and how these choices affect interpretation for rejection and graft-versus-host disease risk modeling, tolerance-focused studies, and immunomodulatory screening. Next, we outline major readouts—radiometric and flow cytometric proliferation (dye dilution, Ki-67), cytokine/chemokine profiling, cytotoxicity adaptations, and next-generation add-ons (e.g., scRNA-seq, TCR sequencing)—emphasizing complementary strengths and common pitfalls. Finally, we consolidate practical quality and reproducibility controls (donor variability, dynamic range, timing, batch effects, and acceptance criteria) to improve cross-study comparability and translational readiness. Modern MLR platforms combine controllable allogeneic stimulation with scalable, high-resolution readouts for mechanistic discovery, immune monitoring and translational immune profiling. Standardized modular design and rigorous quality control can improve reproducibility and support broader adoption across transplantation, immunotherapy, and immune-modulation research. Full article

Background: Auditory brainstem responses (ABRs) are widely used for objective hearing threshold estimation in both adults and children. Click and CE-Chirp stimuli differ substantially in cochlear activation and neural synchrony, yet their relative performance in patients with ski-sloping hearing loss remains insufficiently characterized, particularly with regard to pediatric diagnostic implications. Methods: This study compared ABRs elicited by click and CE-Chirp stimuli in adults with ski-sloping sensorineural hearing loss. The same comparison was also performed in a pediatric cohort including hearing-impaired and normal-hearing children. Adult subjects were further stratified according to audiometric configuration (DROP 1 kHz vs. DROP 2 kHz). ABR thresholds, wave V latency, amplitude, and detectability were analyzed across stimulus types and intensity levels. Associations between ABR thresholds and behavioral audiometric measures were also examined. Results: In adults with ski-sloping hearing loss, CE-Chirp stimulation yielded significantly lower ABR threshold estimates than click stimulation, particularly in the DROP 2 kHz subgroup, and showed stronger correlations with behavioral pure-tone averages across low-, mid-, and high-frequency ranges. Wave V latencies were consistently shorter with CE-Chirp stimulation, while wave V amplitudes did not differ significantly between stimuli at suprathreshold levels. In children, ABR thresholds obtained with CE-Chirp were generally equal to or lower than those obtained with clicks, although statistical significance was limited by sample size. CE-Chirp stimulation was associated with shorter wave V latencies in both hearing-impaired and normal-hearing children and produced larger wave V amplitudes at selected suprathreshold intensities in hearing-impaired children. Conclusions: Click and CE-Chirp stimuli provide complementary information in ABR assessment. While click stimulation remains essential for robust waveform identification, CE-Chirp stimulation appears to offer advantages in threshold estimation and neural synchrony, particularly in ski-sloping hearing loss and pediatric evaluations. Discrepancies between click- and CE-Chirp-derived ABR thresholds should not be attributed solely to maturational or synchrony-related factors but may warrant further frequency-specific audiological assessment to optimize diagnosis and rehabilitation strategies. Full article