The influence of gamma (γ)-irradiation (10 Mrad) on some physical and spectroscopic properties of phosphate glasses doped with MnO2 as 0.5, 2.0, 4.0, 6.0, and 8.0 mol % was assessed, ultimately focusing on the Mn2+ excited-state dynamics. A structural assessment by Fourier-transform infrared spectroscopy was overall consistent with the resilience of the glass structures to undergo significant alteration following γ-irradiation. However, the densities of the more heavily doped glasses (2-8 mol % MnO2) were somewhat higher after γ-irradiation, indicating a tendency toward more compact glasses. The absorption spectra of the pristine glasses exhibited a distinctive increase in the 5Eg → 5T2g transitions band characteristic of Mn3+ (3d4) ions at high manganese content, which was greatly enhanced after γ-irradiation, consistent with Mn2+ photo-oxidation. Optical band gap energies were estimated and compared showing that the γ-irradiated glasses had lower values than the pristine as expected due to electron centers being trapped in the glass matrix. Photoluminescence (PL) spectroscopy showed the red emission from Mn2+ (3d5) ions was prominent in the pristine glasses, however with indications of a quenching effect above 4 mol % MnO2. The PL was then drastically quenched following γ-irradiation. The Mn2+ excited-state lifetimes ascribed to single and interacting ions were found to be consistently shorter for the γ-irradiated glasses despite the lowering in Mn2+ concentration expected given its photo-oxidation to Mn3+. Consequently, a Mn2+ → Mn3+ resonant energy transfer was proposed as a significant emission quenching pathway, which became enhanced after γ-irradiation.
To assess the value of optical coherence tomography angiography (OCTA) peripapillary retinal vascularization in differentiating papilledema from pseudopapilledema. A cross-sectional study, prospective recruitment patients diagnosed with papilledema and pseudopapilledema between January 2021 and December 2022. Papilledema: mild-moderate acute optic disc edema due to increased intracranial pressure. Pseudopapilledema: optic nerve drusen and other causes confirmed by multimodal imaging techniques. Mean and sectoral peripapillary flux index and perfusion density were measured using commercial software. Diagnostic performance was analyzed using the area under the receiver operating characteristic curve (AUC). Sixty-five patients (mean age, 36.5 years; 63.1% women) were included: 14 with papilledema (28 eyes; mean age 37.1 years, 9 women) and 51 with pseudopapilledema (95 eyes, mean age 36.4 years, 32 women), with no significant differences in age or gender. Significant differences were found for flux index in the nasal sector (p = 0.034). Mean perfusion density was significantly higher for papilledema (44.377%) than for pseudopapilledema (42.460%) (p = 0.036), as was perfusion in the nasal sector (p = 0.005). Mean vascular flux index had an AUC of 0.683 (95% CI, 0.518-0.848), with 76.9% sensitivity and 58.8% specificity, with a cut-off of 0.461. Mean perfusion had an AUC of 0.665 (95% CI 0.492-0.838), with 53.8% sensitivity and 76.5% specificity, with a cut-off of 44.25%. OCTA displayed higher peripapillary flux index and perfusion in papilledema than pseudopapilledema in the nasal region. These parameters showed moderate diagnostic accuracy and may serve as adjunctive tools in the differential diagnosis of optic disc swelling.
Neuromorphic visual systems require optoelectronic synaptic devices capable of integrating optical sensing, memory, and processing. However, HfO2-based memristors still face challenges in simultaneously achieving stable resistive switching, efficient light-modulated synaptic plasticity, and device-level visual processing. Here, a sol-gel-derived Au/IGZO/HfO2/FTO heterojunction memristor is developed for optoelectronic synaptic emulation and neuromorphic visual applications. The IGZO/HfO2 heterointerface enables synergistic regulation of oxygen-vacancy-related defects, interfacial charge trapping/detrapping, and photogenerated carrier transport, leading to stable bipolar resistive switching and tunable optoelectronic synaptic behavior. The device emulates diverse synaptic functions, including short-term plasticity, long-term potentiation/depression, paired-pulse response, and learning-forgetting-relearning processes. Its excitatory postsynaptic current can be modulated by optical pulse width, power density, pulse number, and read voltage, with a minimum synaptic energy consumption of 11.925 nJ at 0.001 V under an optical pulse width of 0.5 s. Furthermore, a device-array-based feedback-circuit system enables adaptive image contrast enhancement, while neural network simulations achieve recognition accuracies of 97.94% for MNIST and 84.18% for Fashion-MNIST. These results demonstrate the potential of IGZO/HfO2 heterojunction memristors for low-power neuromorphic visual preprocessing and recognition.
Optically addressable solid-state spin defects are essential platforms for quantum sensing and information processing. Recently, single spin defects with combined S = 1 and S = ½ spin transitions were discovered in hexagonal boron nitride (hBN). In this work we unveil their excitation dynamics. In particular, we study the effects of the excitation wavelength on the spin-dependent fluorescence and the spin dynamics of these peculiar quantum spin defects. We find that changing the excitation wavelength leads to a threefold enhancement in both the optically detected magnetic resonance (ODMR) contrast and the corresponding magnetic field sensitivity. In addition, we find that the excitation wavelength has a strong impact on the photodynamics of spin complex emitters. Our work presents valuable insights to the mechanistic understanding of spin complex emitters in hBN and highlights the importance of excitation wavelength for optimising their performance in quantum sensing and quantum technologies.
Theory predicts that a planet with a sufficiently strong magnetic field orbiting close to its host star could induce star-planet magnetic interactions. This is potentially observable as an optical or radio stellar activity signal synchronised with the planet's orbital period. We analyze 18 years of high-resolution optical spectroscopy of GJ 436, a low mass star orbited by a Neptune-sized exoplanet on a polar eccentric orbit. Stellar activity indicators show enhancements at a period corresponding to the exoplanet orbit, modulated by stellar rotation, and the star's 8-year magnetic cycle. We interpret this as a signal of star-planet magnetic interaction. Using a geometric model, we reproduce these periods if GJ 436 b has a magnetic field strength of 6 to 110 Gauss.
High-quality, annotated datasets are fundamental to clinical research and artificial intelligence (AI) model development. Existing endoscopic databanks are predominantly retrospective, image-based, or lacking patient consent and structured prospective clinical annotations, limiting scientific reproducibility and regulatory-compliant AI validation. This study establishes a prospective endoscopy video databank with standardized annotations enabling AI development and clinical outcomes research. Since 2022, we have prospectively enrolled consecutive patients undergoing esophagogastroduodenoscopy (EGD) or colonoscopy at a tertiary center (NCT06822616). Endoscopies were recorded in full (1920×1080 resolution, 60 frames per second, 10-bit color depth), and de-identified at acquisition. Trained staff documented timestamped anatomical landmarks, lesion characteristics, optical diagnoses, interventions, and disease scores in structured case report forms during procedures. Pathology results and metadata were linked to all events observed during the endoscopies and corresponding timestamped video frames. Up to March 2026 8658 patients (mean age 59.3 years; 52.0% female) were enrolled contributing 10831 procedures (7909 colonoscopies, 2922 EGDs) performed by 55 endoscopists. Each colonoscopy and EGD captured up to 747 and 455 structured variables, respectively. Individual polyps (n=10057) and biopsies (n=11346) were annotated with 49 and 45 variables, respectively. Inflammatory bowel disease-specific documentation comprised up to 188 variables per procedure. Pathological findings were present in 83.7% of records. This prospective databank provides the infrastructure for endoscopy research requiring traceable data sourcing, whether for clinical outcomes research or AI development and validation. The integration of full-length videos, real-time procedural annotation, and histopathological correlation addresses critical gaps in optimizing clinical outcomes and AI research.
The construction of planar chiral [2.2]paracyclophanes (PCPs) is of great importance due to their intriguing photophysical and optoelectronic properties. However, catalytic asymmetric approaches to access valuable heterocyclic PCPs directly remain underexplored. Herein, we present the enantioselective synthesis of planar chiral triazole-based PCPs via a desymmetrizing copper-catalyzed alkyne-azide cycloaddition (CuAAC) reaction. A diverse range of functionalized optically enriched heterocyclic PCPs is obtained in a highly enantioselective manner under mild conditions. Moreover, this protocol showcases the versatility and efficiency of applying the desymmetric CuAAC reaction in the successful construction of planar chirality.
Space situational awareness increasingly relies on optical observations to detect and track resident space objects and to estimate spacecraft attitude. Many existing resources are synthetic or restricted, and few provide on orbit, wide field of view imagery with joint labels for space objects and stars. We present a dataset of near-infrared images acquired by the Fast Auroral Imager on the CASSIOPE spacecraft between January and August 2023. The collection comprises 1,378 frames with astrometrically calibrated stars and 4,237 manually verified resident space object instances across 160 transits, accompanied by spacecraft ephemeris, attitude, and image quality metrics. We describe the acquisition conditions, calibration and annotation pipeline, and perform technical validation of pointing stability, astrometric accuracy, annotation reliability, and background characteristics. The dataset supports tasks such as resident space object detection in dense star fields, multi-object tracking under realistic orbital motion, and attitude estimation from star tracker class imagery, and is intended as a shared resource for space situational awareness and navigation studies.
To evaluate whether real-time intraoperative navigation calibration improves pedicle screw placement accuracy in patients with neurofibromatosis type 1-associated scoliosis. This retrospective study included 63 patients with NF1-associated scoliosis who underwent posterior spinal osteotomy, deformity correction, and instrumented fixation between January 2023 and June 2025. Patients were assigned to a conventional navigation group (n = 30) or a real-time navigation calibration group (n = 33). Pedicle morphology was classified according to Yang's classification, and screw placement accuracy was assessed on postoperative CT using the Rao grading system. Grade 0 indicated no cortical breach; Grades 1, 2, and 3 indicated breaches of < 2 mm, 2-4 mm, and > 4 mm, respectively. A total of 430 pedicles were analyzed, including 230 in the conventional navigation group and 200 in the navigation calibration group. The distribution of pedicle morphology did not differ significantly between the groups. A total of 1,228 pedicle screws were inserted (584 in the conventional navigation group and 644 in the navigation calibration group). The navigation calibration group achieved significantly higher Grade 0 placement rates than the conventional navigation group in Type A, B, and C pedicles on the concave side and in Type A and B pedicles on the convex side. The overall cortical breach rate was also lower in the navigation calibration group. No significant between-group differences were observed in operative time, intraoperative blood loss, or perioperative complications. Real-time intraoperative navigation calibration improved pedicle screw placement accuracy and reduced cortical breaches in NF1-associated scoliosis, particularly in dysplastic pedicles and on the concave side of the deformity. This technique may serve as a practical adjunct to conventional optical navigation in complex spinal deformity surgery.
Photoacoustic imaging (PAI) combines the high contrast of optical absorption with the spatial resolution of ultrasound detection; however, its performance is often constrained by incomplete angular sampling and measurement noise. In this work, we introduce a model-based Kalman filtering framework for estimating virtual sensor measurements at intermediate angular positions of a circular detection array.Instead of adding new detector elements, the method generates statistically consistent virtual measurements from the existing array, effectively enriching the angular information available to the reconstruction algorithm without altering the physical hardware. The Kalman formulation exploits the directional propagation of acoustic waves and the temporal coherence of photoacoustic signals to produce noise-aware, minimum-variance estimates of the pressure field. Using extensive k-Wave simulations that incorporate finite-aperture detectors, acoustic attenuation, and heterogeneous media,we demonstrate that the proposed virtual sensing strategy substantially improves structural preservation and yields higher quantitative image quality compared with interpolation-based methods. These results establish Kalman-domain virtual sensing as a practical and physically grounded approach for augmenting PAI acquisition systems and enhancing reconstruction quality without modifying the detector hardware.
Visual inputs evoke dynamic changes in the responses of visual neurons that evolve over both space and time. All visual experiences must somehow stem from stimulus-evoked spiking patterns in visual brain regions, but determining which neurons and periods of activity causally give rise to perception is one of the grand challenges in neuroscience. Targeted manipulations of neuronal activity while subjects perform sensory tasks have been indispensable for probing computations underlying perception. However, limits on the spatiotemporal precision of neuronal perturbations have constrained the scope of inquiry. Recent advances in optogenetic stimulation approaches have opened the door to augmenting neuronal activity on the spatiotemporal scales of visual computations. Applications of patterned optogenetic stimulation in behaving subjects have revealed many important insights into how different aspects of visual neuronal responses contribute to perception and ultimately behavior. First, we survey optical tools for precise optogenetic perturbations in mice and monkeys. Next, we discuss how patterned optogenetic experiments in behaving subjects have been used to causally test the neural mechanisms underlying perception. Last, we highlight a few key areas that we believe will be important for continued progress in this emerging research area.
A retrospective evaluation of the long-term visual recovery prediction in patients with diabetic macular edema (DME) following aflibercept treatment, based on spectral-domain optical coherence tomography (SD-OCT) parameters at one and four months post-treatment. This study involved 112 eyes of 112 DME patients which received at least one injection of aflibercept. SD-OCT parameters at 1 and 4 months post-aflibercept treatment-including central subfield thickness (CST), the continuity of external limiting membrane (ELM)/ellipsoid zone (EZ) and cone outer segment tip (COST), as well as the counts of retinal hyperreflective retinal foci (HRF), along with best-corrected visual acuity (BCVA) improvement at 12 months post-treatment-were analyzed. The correlation between SD-OCT parameters and BCVA improvement was evaluated using the chi-square or Wilcoxon test, and the predicted value of SD-OCT parameters was assessed via receiver operating characteristic (ROC) curve and binary logistic regression model. Twelve months after aflibercept treatment, BCVA was improved from 0.66 ± 0.46 to 0.48 ± 0.42 logMAR (p = 0.002). The SD-OCT parameters were significantly improved: CST was decreased from 397.05 ± 199.60 to 289.08 ± 119.39 μm; the affected eyes with damaged ELM/EZ and COST decreased from 46 (41.1%) and 71 (63.4%) to 31 (27.7%) and 43 (38.4%), respectively; the number of HRF decreased from 11.00 ± 11.38 to 8.03 ± 9.58. The AUC values for predicting BCVA gain of ≥ 5 letters at 12 months based on SD-OCT parameters at 1 and 4 months post-aflibercept treatment and their combination were 0.812, 0.824, and 0.873, respectively. Multivariate logistic analysis revealed that CST, ELM/EZ, COST, and HRF at 1 and 4 months were all independent predictors of long-term visual improvement outcomes. Intravitreal injection of aflibercept can effectively improve the vision and fundus structure of DME patients. Improvements in short- and medium-term CST, ELM/EZ, COST integrity, and HRF values are key physiological indicators for visual recovery.
We report the case of a 3-year-old pediatric patient with serologically confirmed dengue infection who subsequently developed left exotropia and severe visual impairment. Ophthalmologic examination revealed diffuse retinal and optic disc pallor, alterations of the retinal pigment epithelium, and macular fibrosis. B-mode ultrasonography ruled out intraocular malignancy, and optical coherence tomography demonstrated complete macular atrophy. The clinical findings were consistent with a previous retinal vascular occlusive event. However, the absence of angiographic studies and comprehensive systemic evaluation to exclude other etiologies limits the ability to establish a definitive causal relationship with dengue infection. This case highlights the importance of early ophthalmologic assessment in pediatric patients with recent viral infection and underscores the need for further studies to accurately characterize retinal vascular events.
Bud scales (cataphylls) protect latent shoot apices and preformed organs in the majority of deciduous trees, yet these modified structures of leaf origin and their potential other functions are rarely studied in detail. Here, we investigated seasonal and developmental variations in anatomy by bright-field microscopy; plastid ultrastructure by transmission electron microscopy; optical properties, photosynthetic pigment contents and organization by various spectroscopic methods; photosystem II (PSII) activity by Imaging PAM; and gross photosynthesis by infrared gas exchange analysis in outer brownish and inner greenish bud scales of horse chestnut (Aesculus hippocastanum L.) throughout their lifespan, i.e. from their initiation end of spring until their senescence after the bud break next year. The composition of the resin secreted on the outer bud scales was characterized by HPLC-UV-HRMS following acetonic extraction, revealing methoxylated flavonols as the dominant constituents and suggesting additional roles in photoprotection and chemical defense. Both outer and inner bud scales retained structurally intact, photosynthetically competent chloroplasts throughout all seasons, despite low chlorophyll content and limited photosynthetic capacity. Outer scales exhibited strong light-filtering, photoprotective properties, and pronounced seasonal downregulation of photosynthetic performance, besides their known roles in thermal insulation, and environmental shielding. In contrast, inner scales maintained higher chlorophyll content, more stable PSII efficiency during dormancy, and rapidly recovered photosynthetic activity during bud break, indicating a metabolically poised state supporting early spring development. Our findings underscore bud scales' multifunctional roles as protective barriers and active contributors to plant physiology by photosynthesis and the maintenance of chloroplast ultrastructure throughout their lifespan.
To assess prevalence and associations of localized thinnings of the interdigitation zone ("IZT") without adjacent drusen or reticular pseudodrusen in a general population, affected by age-related macular degeneration (AMD), or free of any other retinal disease. On optical coherence tomographic images, taken from the macula of participants of the population-based Beijing Eye Study, we searched for IZTs. The study population included 1271 eyes (mean age:64.7 ± 9.8 years; range:50-91 years). IZT prevalence increased from 2/442 (0.5%;95%CI:0.0,1.0) in the normal group to 49/543 (9.0%;95%CI:7.0,11.0), 90/275 (32.7%;95%CI:27.2,38.2), and 9/11 (81.8%;95%CI:55.0,100) in eyes with early, intermediate or late AMD (geographic atrophy), respectively. IZTs were spatially associated with ellipsoid zone (EZ) defects (114/150 (76.0%) eyes), external limiting membrane (ELM) defects (92/150 (61.3%) eyes), any intraretinal hyperreflective foci (iHRF) (143/150 (95.2%) eyes), iHRFs in the outer nuclear layer or beyond (111/150 (74.0%) eyes), macular hypopigmentation (76/150 (50.7%) eyes), and RPE hypertransmission (46/150 (30.7%) eyes), in addition to a non-spatial association with a higher prevalence of outer nuclear layer thinning (48/150 (32.0%) eyes). Higher IZT prevalence correlated (multivariable analysis) with higher AMD stage (OR:1.28;95%CI:1.08,1.51;P = 0.004), and higher prevalences of EZ defects (OR:7.97;95%CI:4.20,15.1;P < 0.001), iHRFs with a smoke-like appearance in the outer nuclear layer (OR:2.52;95%CI:1.32,4.82;P = 0.005), RPE hypertransmissions (OR:12.6;95%CI:2.92,54.7;P < 0.001), and outer nuclear layer thinning (OR:27.5;95%CI:6.12,123;P < 0.001). IZTs are a common feature of AMD including the early AMD stage. Their spatial association with defects in the overlying EZ, IHRFs and macular hypopigmentations may warrant further research of a potential involvement of an intraretinal RPE cell migration in the IZT etiology.
Ca2Al2SiO7:Dy3+ phosphor was synthesized by solution combustion method. X-ray diffraction study revealed mixed phases of the phosphor annealed up to 1300 °C. Pure tetragonal phase of Ca2Al2SiO7 was obtained after annealing the synthesized phosphor at 1450 °C. Effect of different doping concentration (0.0 M% to 3.0 M%) and different annealing temperature (400 °C to 1450 °C) on the Continuous Wave Optically Stimulated Luminescence (CW-OSL), and Mechanoluminescence (ML) properties of a gamma irradiated Ca2Al2SiO7:Dy3+ phosphor was studied successfully. The optimum CW-OSL intensity was observed for the Ca2Al2SiO7:Dy3+ (0.6 M%, 1100 °C) phosphor (CASO6D-1100), which showed linear and wide CW-OSL dose response (20 Gy to 5.0 kGy), and good reusability. Moreover, the bleaching time for the complete elimination of traps was found to be only 6 min in order to get the phosphor reused. The traps were observed to get gradually vacated after taking the CW-OSL readouts of the pre-irradiated phosphor several times. The ML studies showed that the maximum ML intensity was observed for the Ca2Al2SiO7:Dy3+ (1.0 M%, 1100 °C) phosphor (CASO10D-1100) and exhibited linear and wide ML dose response (10.0 Gy to 2.0 kGy) with good reusability. Gradual decrease in the ML intensity was observed after carrying out repetitive ML readout cycles. Thus, it is found to be a good candidate for dosimetry applications using CW-OSL and ML techniques.
Metabolic Glycan Labeling (MGL) is a powerful tool to introduce diverse functional entities on cell surface by bioorthogonal labeling of abiotic sugars expressed on the glycocalyx. Akin to the plasma membrane, the luminal face of the lysosomal membrane is covered with a dense layer of glycans. To date, MGL has been mostly executed to modify cell surfaces. Herein we detail organelle-specific MGL (OMGL) by selective labeling of 9-azidosialic acid (AzSia) residues on the lysosomal inner membrane while sparing those on the cell surface. OMGL entails: (1) metabolic incorporation of AzSia into the global cell glycome; (2) staining of the AzSia-expressing cells with dibenzocyclooctyne (DBCO)-bearing lyso-probes, which can promptly accumulate in lysosomes driven by the acidotropic effect; (3) bioorthogonal ligation of lyso-probes enriched in lysosomes with AzSia on the inner membrane of lysosomes. Overcoming the liability of conventional chemical probes to dissipation from stressed lysosomes, OMGL enables optical tracking of stressed lysosomes in exocytosis and cell death.
Honey bees are commonly infected with viruses, including deformed wing virus (DWV-A and DWV-B) and sacbrood virus (SBV), which cause morphological symptoms and death in developing bees and primarily asymptomatic infections in adult bees. Co-infections occur regularly in colonies, but they have rarely been studied, especially in adult bees. In this study, we co-inoculated young adult honey bees with DWV by injection (simulating vectored transmission by Varroa) and feeding them with SBV (simulating oral transmission) before reintroducing them in colonies. Through the use of optical counters and regular sampling, we tracked their survival and behaviour, and quantified the dynamics of viral loads in treated bees as well as the expression of eight immune genes involved in honey bee anti-viral immunity. Here, we show that co-inoculations of DWV and SBV synergistically increase the virulence of DWV and conditionally promote the replication of SBV. We also show that SBV may play a role in the replication of DWV in specific contexts. Finally, our results show that immune responses in adult honey bees depend on virus genotype (i.e., DWV), their relative abundance and the pre-existing natural infections before virus injection). Together, these results confirm the existence of deleterious interactions between deformed wing virus and sacbrood virus, impacting honey bee health and colony dynamics.
The rapid development of weak magnetic sensing technologies, most notably optically pumped magnetometers (OPMs), has enabled flexible and reconfigurable magnetocardiographic source imaging (MCSI) systems. As a paradigmatic distributed sensor platform, MCSI relies critically on the spatial arrangement of sensors, which decisively determines both system-level cost and achievable source reconstruction performance. Nevertheless, principled array design strategies for MCSI remain an unmet need. This study aims to propose a novel strategy for sensor array design in MCSI systems. This study proposes, for the first time to our knowledge, a bi-objective array optimization framework (BoAOF). The framework models array design as a dual-objective optimization problem aimed at maximizing array sensitivity while minimizing the total spatial deviation. It integrates forward modeling with the non-dominated sorting genetic algorithm II (NSGA-II) to generate a Pareto front of sensor configurations, followed by a hybrid CRITIC-Entropy-VIKOR decision process to identify the optimal compromise solution. In both simulation and phantom experiments, the arrays optimized via the BoAOF consistently outperformed competing baseline methods, achieving lower mean dipole localization error, reduced mean spatial deviation, and higher mean source‑reconstruction signal‑to‑noise ratio across a range of channel counts and source strengths. This study proposes a novel strategy for sensor array design in MCSI systems. This work provides a methodological basis for the design of flexible OPM-based MCSI systems.
This study presents an incised ochre artefact from the Yanling site in the Luonan Basin, the Qinling Mountains region, central China. The specimen, recovered from a well-stratified paleosol, bears deep incisions consistent with intentional scoring. The optical stimulated luminescence dating results indicate that the artefact dates to approximately 80 ka ago. Physicochemical analyses, including X-ray fluorescence, X-ray diffraction, and scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy, reveal that the sample consists primarily of iron oxides and clay minerals, which are some of the most frequent constituents in ochre materials and thus support the artefact's identification as an ochre piece. This finding represents the earliest known incised ochre artefact from East Asia and provides new evidence for ochre use and behavioral complexity in the region.