Search Results (32)

Photobiomodulation (PBM) is a non-invasive therapeutic strategy that uses red and near-infrared (NIR) light in the 590–950 nm range to modulate the cellular and molecular pathways involved in retinal homeostasis. At the molecular level, PBM acts primarily through photon absorption by cytochrome c oxidase (CcO, complex IV of the mitochondrial electron transport chain), whose four metal centres—two copper (CuA and CuB) and two heme groups (heme a and heme a₃)—absorb light across approximately 600–1000 nm. Photon capture promotes photodissociation of inhibitory nitric oxide (NO) from the binuclear CuB–heme a₃ centre, accelerates electron transfer, restores the proton-motive force and increases ATP synthesis. These primary events trigger a coordinated molecular programme that includes (i) transient mitochondrial reactive oxygen species (ROS) bursts that activate the Nrf2/Keap1/ARE axis and upregulate phase II antioxidant enzymes (HO-1, NQO1, GCLC, SOD2, catalase, GPx); (ii) calcium- and cAMP-dependent secondary signalling that converges on PI3K/Akt, MAPK/ERK, AMPK and mTOR pathways; (iii) suppression of NF-κB-driven cytokine production (TNF-α, IL-1β, IL-6) and of NLRP3 inflammasome activation; (iv) downregulation of the HIF-1α/VEGF axis, particularly at 590 nm; (v) anti-apoptotic remodelling of the Bcl-2/Bax ratio with reduced cytochrome c release and caspase-3/9 activation; and (vi) PGC-1α/TFAM/NRF1-driven mitochondrial biogenesis, alongside restoration of fission/fusion homeostasis (Drp1, Mfn1/2, Opa1) and PINK1/Parkin-mediated mitophagy. Wavelength specificity has a defined molecular basis: 590 nm modulates VEGF signalling and RPE pump activity, 660 nm interacts with the CuB centre and enhances O₂ binding at CcO, and 850 nm is absorbed by CuA and supports electron entry into complex IV. A second molecular axis is the bidirectional crosstalk between PBM and the circadian system: mitochondrial respiration, ATP turnover and CcO activity oscillate over the 24 h cycle under the control of the BMAL1/CLOCK and PER/CRY core machinery, the NAD⁺/SIRT1–SIRT3 axis and REV-ERBα. Preliminary preclinical and human observations suggest that NIR-induced bioenergetic and functional gains may be coupled to this rhythm, with greater benefit reported when light is delivered in the morning window (≈08:00–11:00); this time dependence should be regarded as an emerging hypothesis rather than an established clinical principle. The clinical evidence is unevenly developed across indications. It is most robust for non-exudative age-related macular degeneration, where multiwavelength PBM (590/660/850 nm; Valeda Light Delivery System) has shown disease-modifying potential in randomized controlled trials (LIGHTSITE I–III and the LIGHTSITE IIIB extension), with sustained BCVA gains and reduced incidence of geographic atrophy over 24 months and beyond. Evidence for retinitis pigmentosa, central serous chorioretinopathy and, with red-light monotherapy, childhood myopia is at present limited to small or short-term studies and remains preliminary. This narrative review synthesizes the molecular machinery engaged by PBM, integrates clinical findings across retinal diseases and discusses how chronotherapeutic delivery of light, aligned with the molecular clock, may further optimize therapeutic efficacy. Full article

The Sugars Will Eventually be Exported Transporters (SWEET) family plays a crucial role in the carbohydrate distribution, phloem loading, and stress response of plants, yet the evolutionary characteristics and functional diversification of SWEET genes in the endangered timber species Phoebe bournei (Hemsl.) Yen C. Yang remain largely unexplored. In this study, 21 PbSWEET genes were identified and classified into four subfamilies (A–D). Subfamily A exhibited a unique lineage expansion, mainly driven by tandem and segmental duplications. The nonsynonymous-to-synonymous substitution ratio (Ka/Ks) values of all duplicate gene pairs were all less than 1, indicating a strong selective suppression effect; consistent with this evolutionary constraint, the majority of PbSWEET proteins harbor the conserved Medicago truncatula Nodulin 3/saliva (MtN3_slv) domain, with only a few exceptions lacking a complete version. Promoter and hormone response analyses revealed that under abscisic acid (ABA) stress, PbSWEET4 exhibited an immediate burst, whereas PbSWEET10 showed a delayed burst. Physiological data indicated that soluble sugars may be more dominant osmolytes than proline (Pro), a pattern that points to a potential carbon-centric regulatory strategy. PbSWEET4 showed an early burst before sugar/oxidative peaks, suggesting a possible non-canonical signaling role, whereas PbSWEET10 exhibited a late increase coinciding with sugar/malondialdehyde (MDA) peaks, suggesting potential involvement in sugar redistribution. Under methyl jasmonate (MeJA) treatment, PbSWEET10 was rapidly induced, yet sugar accumulation occurred only at 24 h, a temporal decoupling that suggests a possible transcription–metabolism decoupling. Collectively, these correlative patterns point to a possible dual-wave transcriptional mechanism and nominate PbSWEET10 as a candidate for stress response, though these inferences require functional validation. Full article

During deep anesthesia, the EEG becomes discontinuous. Burst-suppression is often an intended target during deep sedation or medically induced coma. Within this state, anesthetic depth is commonly monitored by the suppression ratio (SR), which expresses the fraction of time spent in suppression. However, accumulating evidence suggests that SR remains reactive to external stimulation. We tested whether ambient music commonly played in operating theaters alters the SR in male Wistar rats under sevoflurane, chloral hydrate, or isoflurane anesthesia. To this end, the first 60 s of the Stayin’ Alive audio track by the Bee Gees were played to examine auditory-induced burst-suppression reactivity in an experimental model previously established for intermittent photic stimulation. SR and the burst-suppression reactivity index (BSRi, derived as the decrease in SR during stimulation normalized to pre-stimulation SR) were measured in repeated trials. Auditory stimulation transiently decreased SR under all three anesthetics. This was associated with an increase in the rate of burst occurrence without increased burst duration. The BSRi changes depended on the anesthetic type, comparable to photic stimulation. Our experimental data suggest that the suppression ratio used to monitor targeted burst-suppression reflects both anesthetic depth and the level of ambient stimulation. Ambient sound in the operating theater or intensive care settings could influence EEG-based measures used for anesthesia monitoring. Full article

To enhance the aerodynamic performance of Ti6Al4V functional components, this paper systematically investigated the femtosecond laser processing technology for surface drag-reduction microstructures, aiming to fabricate high-performance microstructures. (1) V-shaped, U-shaped, and rectangular micro-grooves were designed based on the boundary layer theory, and their drag-reduction mechanisms were elucidated through CFD numerical simulations. The results indicate that the V-shaped groove achieves a peak drag-reduction rate of 13.1% at a dimensionless depth of h⁺ = 15 and an aspect ratio of 1, primarily due to the formation of a low-velocity zone and the suppression of turbulent bursts by secondary vortices. (2) Through single-factor experiments, the influence laws of femtosecond laser process parameters on the V-shaped groove were explored. (3) Regression prediction models for groove dimensions were established using the Response Surface Methodology (RSM) to optimize the processing parameters. Under the optimized conditions, high-quality V-shaped groove arrays with a width of 55.9 μm and a depth of 55.5 μm were successfully fabricated on the Ti6Al4V surface, characterized by high consistency and a minimal heat-affected zone. This research provides an effective technical solution for the precision manufacturing of high-performance drag-reduction structures on titanium alloy surfaces. Full article

Background/Objectives: Birth asphyxia is a frequent neonatal complication in humans. Its outcome is variable, and the factors underlying this variability remain incompletely understood. Maternal gut microbiome impairment has been proposed as one factor that may influence offspring neurodevelopment, especially when the immature brain is exposed to additional vulnerability such as perinatal asphyxia (PA). Building on our previous maternal microbiome disruption model and on our prior observation that electroencephalography (EEG) reactivity to photic stimulation under deep anesthesia detects functional impairment two months after PA, we assessed whether this reactivity was further impaired after prolonged gestational antibiotic administration and whether probiotics modulated this effect. Methods: Wistar dams received antibiotics, probiotics, antibiotics with probiotics, or control treatment, and offspring underwent PA. Adult EEG reactivity to photic stimulation was assessed during chloral hydrate-induced burst suppression. Burst count reactivity (BCR) was used as the primary event-based readout of stimulus-evoked burst recruitment and was compared with the suppression-ratio-based burst-suppression reactivity index (BSRi). Results: Burst suppression remained reactive to photic stimulation in all groups. BCR was lower after gestational antibiotic treatment than in controls. The magnitude of the effect was attenuated by probiotics coadministration. BSRi showed the same overall pattern. Conclusions: Prolonged gestational antibiotic exposure increased the severity of perinatal asphyxia as measured by EEG reactivity in the adult offspring. The converging BCR and BSRi results support burst-suppression reactivity as a functional neurophysiological readout in this PA model and support further methodological development of EEG reactivity measures for translational studies of hypoxic–ischemic brain injury. Full article

This article presents a low ripple, high voltage-conversion-ratio (VCR = 6), two-stage step-up converter intended for power-burst applications. The first boost stage raises the battery voltage to a maximum of 35 V, while the subsequent low dropout regulator (LDO) stage suppresses the ripple of the final output. Unlike conventional structures in which control circuits operate above a ground-referenced rail, the proposed shunt-current-reusing technique places most of the control circuits within a narrow floating dropout region (V_DROP) between the boost output (V_BST) and the LDO output (V_OUT), thereby achieving nearly 100% current efficiency through current recycling. Adaptive adjustment of V_DROP (0.5 V at light load and 0.65 V at heavy load) balances output ripple against the loss of the LDO stage. Consequently, the proposed converter achieves both high efficiency (>85%) and low ripple (<2 mV) over a load range from 200 μA to 100 mA, with a peak efficiency of 90.4% at a 20 mA load. Hysteretic control of the boost stage combined with the high bandwidth (BW = 1.2 MHz) of the LDO stage yields a fast transient response (<20 μs). The proposed techniques address the requirements of applications that demand high intermittent power bursts (>1 W) at high supply voltage (>20 V) while maintaining low quiescent current consumption under most load conditions (<10 mA), as exemplified by light detection and ranging (LiDAR), haptic sensors, and micro electromechanical system (MEMS) drivers. Full article

Background: Cardiopulmonary bypass (CPB) is an essential technique for cardiac surgery but significantly increases the risk of perioperative neurological complications. Electroencephalography (EEG) enables real-time monitoring of brain function and provides sensitive biomarkers for early detection of cerebral injury. However, a systematic synthesis of how CPB-related physiological, pharmacological, and technical factors influence EEG signals, and how these insights can be integrated into clinical decision-making, is still lacking. Objective: To systematically review the effects of temperature management, mean arterial pressure (MAP), hemodilution, anesthetic agents, embolization, and systemic inflammatory response during CPB on EEG parameters (including frequency bands, Bispectral Index (BIS), quantitative EEG metrics such as burst suppression ratio (BSR), spectral edge frequency (SEF), etc.), and to evaluate the associations between EEG changes and postoperative delirium (POD) and stroke. Methods: Following the PRISMA 2020 guidelines, we searched PubMed, Web of Science, and related databases for original English-language articles published between February 1974 and September 2025. Inclusion criteria: adult patients (≥18 years) undergoing cardiac surgery with CPB and intraoperative EEG monitoring (raw or processed). Exclusion criteria: reviews, case reports, animal studies, pediatric populations, and articles with inaccessible full texts. Two reviewers independently screened the literature and extracted data; a narrative synthesis was performed. Results: Fifty-one studies were included. Main findings: (1) Hypothermia: BIS decreases linearly with temperature (≈1.12 units/°C); electrocerebral silence occurs during deep hypothermic circulatory arrest; EEG recovery dynamics during rewarming predict POD. (2) MAP and cerebral perfusion: The rate of MAP decline (≥0.66 mmHg/s) is a stronger predictor of EEG abnormalities than the absolute MAP value; under fixed pump flow, some patients exhibit coexisting cerebral overperfusion and metabolic suppression. (3) Hemodilution: Maintaining hemoglobin ≥9.4 g/dL prevents EEG slowing; a drop below 9.2 g/dL significantly increases the risk of slowing. A ≥10% decrease in regional cerebral oxygen saturation (rSO₂) is associated with a 1.5-fold increased risk of burst suppression. (4) Anesthetic agents: Propofol maintains flow-metabolism coupling, and BSR reflects deep anesthesia better than BIS; sevoflurane and isoflurane impair autoregulation and suppress EEG. (5) Embolization and inflammation: EEG epileptiform discharges increase the risk of POD five-fold; a decrease in LIR predicts stroke (AUC 0.771) and POD (AUC 0.779); persistent EEG changes increase the risk of POD 2.65-fold. Conclusions: CPB-related factors affect EEG signals through distinct mechanisms, and specific EEG patterns (slowing, burst suppression, asymmetry, epileptiform discharges) are significantly associated with postoperative neurological complications. Multimodal monitoring (EEG + cerebral oximetry + hemodynamics) with clear intervention thresholds facilitates individualized brain protection. Future interventional studies using real-time EEG feedback are needed to confirm improvements in long-term neurological outcomes. Full article

Background/Objectives: Emergency surgical patients are at increased risk of acute postoperative delirium. Processed EEG monitoring, such as entropy indices and burst suppression ratio (BSR), may optimize anesthetic dosing, yet their role in non-elective surgery remains underexplored. This retrospective cohort study aimed to examine whether entropy monitoring and intraoperative burst suppression are associated with the incidence of early postoperative delirium during the first 72 h after emergency surgery. Methods: Adult patients undergoing emergency surgery between March 2022 and March 2024 were classified into two groups based on anesthesia records: the entropy-monitored group (EG) and the standard care group without processed EEG (SG). Demographic, intraoperative, and cognitive data (NEECHAM scores during the first 72 h) were extracted from institutional perioperative records. The primary outcome was postoperative delirium (NEECHAM ≤ 24), with secondary analyses examining anesthetic exposure, burst suppression, and intraoperative hemodynamics. Results: Entropy-monitored patients received lower sevoflurane and fentanyl doses and exhibited improved hemodynamic stability, including fewer hypotensive episodes and lower norepinephrine requirements. Early postoperative cognitive dysfunction (NEECHAM ≤ 24) was more frequent among patients with intraoperative burst suppression, with BSR > 15% or suppression duration > 6 min strongly associated with cognitive decline within the first 72 h. Conclusions: In this retrospective cohort, entropy-guided anesthesia was associated with more precise anesthetic titration and more stable hemodynamic parameters. Burst suppression characteristics may serve as indicators of neurocognitive vulnerability rather than solely reflecting direct effects of anesthetic dosing. These results support the use of processed EEG monitoring in emergency surgery, though prospective studies are needed to confirm these findings. Full article

The production of a stable and uniform spray is a primary concern in fuel atomization applications, such as in fluid catalytic cracking reactors, directly affecting the process quality and gas emissions. However, depending on nozzle geometry and operating conditions, undesired pulsed spray behavior may occur. This phenomenon originates from the internal multiphase flow interaction in Y-jet nozzles and leads to unstable sprays. Understanding the formation of spray pulsations is challenging due to limited internal flow visualization in the nozzle and the fast dynamics involved. Accordingly, this work elucidates the mechanisms of the pulsed spray formation through 3D transient numerical multiphase simulations inside a mixing chamber. The model is validated against internal pressure measurements and applied to investigate the internal mixing behavior across several operating conditions. Results show that the liquid-to-gas momentum flux ratio governs the internal flow regimes. A higher liquid momentum flux obstructs the gas flow, leading to periodic spray bursts when the gas overcomes the liquid back pressure. The simulations also reveal self-sustained oscillatory flow patterns and cyclic transitions between gas penetration and liquid accumulation, which produce periodic pressure fluctuations and nozzle discharge pulsations. The findings offer valuable guidance for optimizing nozzle operation and geometry to suppress pulsation and improve atomization performance. Full article

To sustain high-throughput extreme ultraviolet (EUV) lithography, pellicles with high transmittance are essential. As conventional methods—such as material optimization and membrane thinning—have reached their practical limits, alternative strategies are now required. In this study, we investigate an alternative hole-patterned pellicle architecture that introduces a geometric degree of freedom beyond that of continuous-film architectures. EUV transmittance measurements show that transmittance increases with open ratio (OR), following the absorption-limited trend predicted by an OR-based upper bound model, while exhibiting a measurable deviation at higher OR. To provide structural insight into this deviation, pseudo-spectral time domain (PSTD) simulations were performed under scanner-relevant numerical aperture and illumination conditions, solely to extract qualitative angular redistribution trends associated with hole geometry. Lithographic aerial-image simulations indicate that pattern distortion effects emerge only under highly coherent illumination and are suppressed as radius sigma σ_r increases. Mechanical characterization using bulge tests reveals distinct pressure–deflection behavior in hole-patterned membranes compared with continuous films, including earlier pressure saturation and modified burst-failure statistics. Although a modest reduction in mean burst pressure is observed, the hole-patterned membranes exhibit a narrower failure distribution, reflecting altered defect sensitivity. Taken together, the results demonstrate how periodic perforation influences transmittance behavior and mechanical response, providing design-relevant trends that complement existing material- and thickness-based pellicle optimization approaches. Full article

Artocarpin, a flavonoid derived from Artocarpus altilis, has been reported to exhibit anti-inflammatory and geroprotective activities. In this study, artocarpin was isolated from A. altilis heartwood via maceration followed by chromatographic purification, yielding 0.435% of dried extract with a purity of approximately 81%, as confirmed by HPLC. To enhance the physicochemical stability and biological performance of artocarpin, a chitosan-based microparticle delivery system was developed using 0.1% chitosan cross-linked with 0.5% sodium tripolyphosphate (5:1 ratio). The optimized formulation achieved an encapsulation efficiency of 0.5 µg of artocarpin per mg of particles (loading content 0.05% w/w). Physicochemical analysis revealed that the particles possessed a predominantly spherical morphology with sizes ranging from 1 to 4 µm. The hydrodynamic diameter measured by DLS was approximately 3.3 µm, with a PDI of 0.79 ± 0.18 and a zeta potential of 12.8 mV, indicating acceptable dispersity and colloidal stability for a chitosan-based microparticle system. FTIR and XRD analyses verified successful incorporation of artocarpin into the chitosan matrix. In vitro release studies showed a biphasic pattern with an initial burst within 1–12 h followed by sustained release, reaching approximately 60% cumulative release. The anti-inflammatory activity of the formulations was evident through a dose-dependent reduction in nitric oxide production in LPS-stimulated RAW 264.7 macrophages. The artocarpin-loaded particles (CSPs/AE) suppressed NO levels by 34.33 to 73.19%, with statistically significant decreases at p < 0.05. These results highlight the potential of artocarpin-loaded chitosan microparticles as an effective anti-inflammatory delivery system with promising applicability for osteoarthritis management. Full article

The present study investigates the influence of atomizing air-to-liquid mass ratio (ALR) on the near-field spray characteristics and stability of a novel twin-fluid injector that integrates bubble-bursting for primary atomization and shear-induced secondary atomization. Unlike conventional injectors, the novel design generates ultra-fine sprays at the exit with low sensitivity to liquid properties. The previous version improved secondary atomization even for highly viscous liquids, showing strong potential in hydrogel-based fire suppression. The current design improves primary atomization, leading to more stable and finer sprays. The near-field spray characteristics are quantified using a high-speed shadowgraph across ALRs ranging from 1.25 to 2.00. This study found that stable and finely atomized sprays are produced across all the tested ALRs. Increasing ALR reduces droplet size, while the spray is the widest at 1.25. Sauter Mean Diameter (SMD) contours show larger droplets at the edges and smaller ones toward the center, with ALR 2.00 yielding the most uniform size distribution. As per the atomization efficiency, ALR of 1.25 shows the best performance. Overall, an optimum ALR of 1.75 is identified, offering balanced droplet size distribution, stability, and atomization efficiency, making the injector potentially suitable for fire suppression and liquid-fueled gas turbines requiring high stability and fuel flexibility. Full article

This study employs Particle Image Velocimetry (PIV) technology to investigate the statistical properties and flow structures of the turbulent boundary layer over smooth walls and riblet walls with yaw angles of 0, ±30° in both clear water and liquid–solid two-phase flow fields. The results indicate that, compared to the smooth wall, streamwise riblet walls and 30° divergent riblet walls can reduce the boundary layer thickness, wall friction force, comprehensive turbulence intensity, and Reynolds stress, with the divergent riblet wall being more effective. In contrast, convergent riblet walls have the opposite effect. The addition of particles leads to an increase in boundary layer thickness and a reduction in wall friction resistance, primarily by reducing turbulence fluctuations and Reynolds stress in the logarithmic region of the turbulent boundary layer. Moreover, the two types of drag-reduction riblet walls can decrease the energy content ratio of near-wall streak structures and suppress their motion in the spanwise direction. Their impact on burst events is mainly characterized by a reduction in the number of ejection events and their contribution to Reynolds shear stress. In comparison, convergent riblet walls have the complete opposite effect and also enhance the intensity of burst events. The addition of particles can fragment streak structures and suppress the intensity and number of burst events, acting similarly on drag-reduction riblet walls and further strengthening their drag reduction characteristics. Full article

Objective: Clinically, patients in a coma after cardiac arrest are given the prognosis of “neurological recovery” to minimize discrepancies in opinions and reduce judgment errors. This study aimed to analyze the background patterns of electroencephalogram (EEG) signals from such patients to identify the key indicators for assessing the prognosis after coma. Approach: Standard machine learning models were applied sequentially as feature selectors and filters. CatBoost demonstrated superior performance as a classification method compared to other approaches. In addition, Shapley additive explanation (SHAP) values were utilized to rank and analyze the importance of the features. Results: Our results indicated that the three different EEG features helped achieve a fivefold cross-validation receiver-operating characteristic (ROC) of 0.87. Our evaluation revealed that functional connectivity features contribute the most to classification at 70%. Among these, low-frequency long-distance functional connectivity (45%) was associated with a poor prognosis, whereas high-frequency short-distance functional connectivity (25%) was linked with a good prognosis. Burst suppression ratio is 20%, concentrated in the left frontal–temporal and right occipital–temporal regions at high thresholds (10/15 mV), demonstrating its strong discriminative power. Significance: Our research identifies key electroencephalographic (EEG) biomarkers, including low-frequency connectivity and burst suppression thresholds, to improve early and objective prognosis assessments. By integrating machine learning (ML) algorithms, such as Gradient Boosting Models and Support Vector Machines, with SHAP-based feature visualization, robust screening methods were applied to ensure the reliability of predictions. These findings provide a clinically actionable framework for advancing neurological prognosis and optimizing patient care. Full article

This study evaluated electroencephalogram [EEG] and cardiovascular correlation of sevoflurane anesthesia in healthy beagle dogs at varying minimum alveolar concentration (MAC) multiples. Processed EEG indices (Patient State Index [PSI], burst suppression ratio [SR], and Spectral Edge Frequency [SEF95], cardiovascular parameters (mean blood pressure [MBP], heart rate [HR]), and responses to noxious (electrical) stimuli were recorded. Deep anesthesia (2.5x MAC) resulted in the lowest PSI and MBP values (13.5 ± 9.9, 42.2 ± 7.4 mmHg, respectively), the highest SR (52.7 ± 35.4%), and dominant burst suppression. Surgical anesthesia (1.5x MAC) was characterized by alpha/low beta waves and the absence of response to noxious stimuli. At 1x MAC (2.1%), PSI and MBP increased (41.9 ± 12.6, 119.9 ± 17.7, respectively) while SR decreased (7.1 ± 13%). A moderate PSI-MBP correlation (ρ = 0.48, p = 0.002) was observed. Recovery was acceptable or smooth in most dogs. These findings suggest that sevoflurane disrupts cortical communication, inducing anesthesia and antinociception and that real-time EEG monitoring may aid in titrating sevoflurane delivery in conjunction with MBP. Full article