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Significance: Intravital cellular calcium imaging has emerged as a powerful tool to investigate how different types of neurons interact at the microcircuit level to produce seizure activity, with newfound potential to understand epilepsy. Although many methods exist to measure seizure-related activity in traditional electrophysiology, few yet exist for calcium imaging. Aim: To demonstrate an automated algorithmic framework to detect seizure-related events using calcium imaging--including the detection of pre-ictal spike events, propagation of the seizure wavefront, and terminal spreading waves for both population- level activity and that of individual cells. Approach: We developed an algorithm for precise recruitment detection of population and individual cells during seizure-associated events, which broadly leverages averaged population activity and high-magnitude slope features to detect single-cell pre-ictal spike and seizure recruitment. We applied this method to data recorded using awake in vivo two-photon calcium imaging during pentylenetetrazol-induced seizures in mice. Results: We demonstrate that our detected recruitment times are concordant with visually identified labels provided by an expert reviewer and are sufficiently accurate to model the spatiotemporal progression of seizure-associated traveling waves. Conclusions: Our algorithm enables accurate cell recruitment detection and will serve as a useful tool for researchers investigating seizure dynamics using calcium imaging. [ABSTRACT FROM AUTHOR]

SignificancePerturbation and differential Monte Carlo (pMC/dMC) methods, used in conjunction with nonlinear optimization methods, have been successfully applied to solve inverse problems in diffuse optics. Application of pMC to systems over a large range of optical properties requires optimal "placement" of baseline conventional Monte Carlo (cMC) simulations to minimize the pMC variance. The inability to predict the growth in pMC solution uncertainty with perturbation size limits the application of pMC, especially for multispectral datasets where the variation of optical properties can be substantial.AimWe aim to predict the variation of pMC variance with perturbation size without explicit computation of perturbed photon weights. Our proposed method can be used to determine the range of optical properties over which pMC predictions provide sufficient accuracy. This method can be used to specify the optical properties for the reference cMC simulations that pMC utilizes to provide accurate predictions over a desired optical property range.ApproachWe utilize a conventional error propagation methodology to calculate changes in pMC relative error for Monte Carlo simulations. We demonstrate this methodology for spatially resolved diffuse reflectance measurements with ±20% scattering perturbations. We examine the performance of our method for reference simulations spanning a broad range of optical properties relevant for diffuse optical imaging of biological tissues. Our predictions are computed using the variance, covariance, and skewness of the photon weight, path length, and collision distributions generated by the reference simulation.ResultsWe find that our methodology performs best when used in conjunction with reference cMC simulations that utilize Russian Roulette (RR) method. Specifically, we demonstrate that for a proximal detector placed immediately adjacent to the source, we can estimate the pMC relative error within 5% of the true value for scattering perturbations in the range of [-15%,+20%]. For a distal detector placed at ∼3 transport mean free paths relative to the source, our method provides relative error estimates within 20% for scattering perturbations in the range of [-8%,+15%]. Moreover, reference simulations performed at lower (μs'/μa) values showed better performance for both proximal and distal detectors.ConclusionsThese findings indicate that reference simulations utilizing continuous absorption weighting (CAW) with the Russian Roulette method and executed using optical properties with a low (μs'/μa) ratio spanning the desired range of μs values, are highly advantageous for the deployment of pMC to obtain radiative transport estimates over a wide range of optical properties.

Pancreatic cancer is difficult to resect due to its unique challenges, often leading to incomplete tumor resections. Fluorescence-guided surgery (FGS), also known as intraoperative molecular imaging and optical surgical navigation, is an intraoperative tool that can aid surgeons in complete tumor resection through an increased ability to detect the tumor. To target the tumor, FGS contrast agents rely on biomarkers aberrantly expressed in malignant tissue compared to normal tissue. These biomarkers allow clinicians to identify the tumor and its stage before surgical resection and provide a contrast agent target for intraoperative imaging. Mucins, a family of glycoproteins, are upregulated in malignant tissue compared to normal tissue. Therefore, these proteins may serve as biomarkers for surgical resection. Intraoperative imaging of mucin expression in pancreatic cancer can potentially increase the number of complete resections. While some mucins have been studied for FGS, the potential ability to function as a biomarker target extends to the entire mucin family. Therefore, mucins are attractive proteins to investigate more broadly as FGS biomarkers. This review summarizes the biomarker traits of mucins and their potential use in FGS for pancreatic cancer.

BACKGROUND: Recent 3-dimensional optical (3DO) imaging advancements have provided more accessible, affordable, and self-operating opportunities for assessing body composition. 3DO is accurate and precise in clinical measures made by DXA. However, the sensitivity for monitoring body composition change over time with 3DO body shape imaging is unknown. OBJECTIVES: This study aimed to evaluate the ability of 3DO in monitoring body composition changes across multiple intervention studies. METHODS: A retrospective analysis was performed using intervention studies on healthy adults that were complimentary to the cross-sectional study, Shape Up! Adults. Each participant received a DXA (Hologic Discovery/A system) and 3DO (Fit3D ProScanner) scan at the baseline and follow-up. 3DO meshes were digitally registered and reposed using Meshcapade to standardize the vertices and pose. Using an established statistical shape model, each 3DO mesh was transformed into principal components, which were used to predict whole-body and regional body composition values using published equations. Body composition changes (follow-up minus the baseline) were compared with those of DXA using a linear regression analysis. RESULTS: The analysis included 133 participants (45 females) in 6 studies. The mean (SD) length of follow-up was 13 (5) wk (range: 3-23 wk). Agreement between 3DO and DXA (R2) for changes in total FM, total FFM, and appendicular lean mass were 0.86, 0.73, and 0.70, with root mean squared errors (RMSEs) of 1.98 kg, 1.58 kg, and 0.37 kg, in females and 0.75, 0.75, and 0.52 with RMSEs of 2.31 kg, 1.77 kg, and 0.52 kg, in males, respectively. Further adjustment with demographic descriptors improved the 3DO change agreement to changes observed with DXA. CONCLUSIONS: Compared with DXA, 3DO was highly sensitive in detecting body shape changes over time. The 3DO method was sensitive enough to detect even small changes in body composition during intervention studies. The safety and accessibility of 3DO allows users to self-monitor on a frequent basis throughout interventions. This trial was registered at clinicaltrials.gov as NCT03637855 (Shape Up! Adults; https://clinicaltrials.gov/ct2/show/NCT03637855); NCT03394664 (Macronutrients and Body Fat Accumulation: A Mechanistic Feeding Study; https://clinicaltrials.gov/ct2/show/NCT03394664); NCT03771417 (Resistance Exercise and Low-Intensity Physical Activity Breaks in Sedentary Time to Improve Muscle and Cardiometabolic Health; https://clinicaltrials.gov/ct2/show/NCT03771417); NCT03393195 (Time Restricted Eating on Weight Loss; https://clinicaltrials.gov/ct2/show/NCT03393195), and NCT04120363 (Trial of Testosterone Undecanoate for Optimizing Performance During Military Operations; https://clinicaltrials.gov/ct2/show/NCT04120363).

Summary: The ability to visualize and track multiple biological processes in vivo in real time is highly desirable. Bioluminescence imaging (BLI) has emerged as an attractive modality for non-invasive cell tracking, with various luciferase reporters enabling parallel monitoring of several processes. However, simultaneous multiplexed imaging in vivo is challenging due to suboptimal reporter intensities and the need to image one luciferase at a time. We report a multiplexed BLI approach using a single substrate that leverages bioluminescence resonance energy transfer (BRET)-based reporters with distinct spectral profiles for triple-color BLI. These luciferase-fluorophore fusion reporters address light transmission challenges and use optimized coelenterazine substrates. Comparing BRET reporters across two substrate analogs identified a green-yellow-orange combination that allows simultaneous imaging of three distinct cell populations in vitro and in vivo. These tools provide a template for imaging other biological processes in vivo during a single BLI session using a single reporter substrate.

Adaptive Optics (AO) has emerged as a revolutionary technology in ophthalmology, offering an unprecedented view into the eye's microstructures with high-resolution imaging capabilities. Originally developed for astronomy, AO technology has been adapted to correct the eye’s optical aberrations, enabling the visualization of individual cellular structures such as photoreceptors, retinal pigment epithelium cells, and capillaries within the retinal vasculature. This review provides a comprehensive overview of AO, discussing its historical background, technical principles, and incorporation into existing systems. We explore its transformative impact on ophthalmic research and clinical practice, highlighting its role in enhancing our understanding of ocular physiology, disease progression, and response to therapies. The clinical applications of AO, including early disease detection and monitoring, are examined alongside the patient experience and economic considerations. Despite its potential, AO's widespread adoption is currently limited by factors such as high costs, technical complexity, and patient cooperation challenges. We discuss these barriers and the innovative solutions emerging to overcome them, including system simplification, expanded fields of view, and advanced image analysis techniques. The article concludes by reflecting on the promising future of AO, with its evolving role in disease management, surgical planning, and systemic disease monitoring. As AO technology continues to advance, it promises to reshape the landscape of ophthalmic care, offering deeper insights into eye health and more precise patient care.

Summary: Zebrafish and organoids, crucial for complex biological studies, necessitate an imaging system with deep tissue penetration, sample protection from environmental interference, and ample operational space. Traditional three-photon microscopy is constrained by short-working-distance objectives and falls short. Our long-working-distance high-collection-efficiency three-photon microscopy (LH-3PM) addresses these challenges, achieving a 58% fluorescence collection efficiency at a 20 mm working distance. LH-3PM significantly outperforms existing three-photon systems equipped with the same long working distance objective, enhancing fluorescence collection and dramatically reducing phototoxicity and photobleaching. These improvements facilitate accurate capture of neuronal activity and an enhanced detection of activity spikes, which are vital for comprehensive, long-term imaging. LH-3PM’s imaging of epileptic zebrafish not only showed sustained neuron activity over an hour but also highlighted increased neural synchronization and spike numbers, marking a notable shift in neural coding mechanisms. This breakthrough paves the way for new explorations of biological phenomena in small model organisms.

Summary: The outcome of cell signaling depends not only on signal strength but also on temporal progression. We use Fluorescence Lifetime Imaging of Resonance Energy Transfer (FLIM/FRET) biosensors to investigate intracellular signaling dynamics. We examined the β1 receptor-Gαs-cAMP signaling axis using both widefield frequency domain FLIM (fdFLIM) and fast confocal time-correlated single photon counting (TCSPC) setups. Unexpectedly, we observed that fdFLIM revealed transient cAMP responses in HeLa and Cos7 cells, contrasting with sustained responses as detected with TCSPC. Investigation revealed no light-induced effects on cAMP generation or breakdown. Rather, folic acid present in the imaging medium appeared to be the culprit, as its excitation with blue light sensitized degradation of β1 agonists. Our findings highlight the impact of subtle phototoxicity on experimental outcomes, advocating confocal TCSPC for reliable analysis of response kinetics and stressing the need for full disclosure of chemical formulations by scientific vendors.

Pathogenic bacteria in wounds impede successful skin grafting. However, their detection relies on culture methods, which delay confirmation by several days. Real-time fluorescence imaging detects bacteria, allowing for rapid assessment and documentation. We herein report a post modified radical mastectomy, surgical site infection with multidrug-resistant Pseudomonas spp. that underwent repeated antibiotic therapy and debridement and eventually grafting. In this case, a real-time fluorescence imaging device helped prevent graft rejection.

In assessing food microbial safety, the presence of Escherichia coli is a critical indicator of fecal contamination. However, conventional detection methods require the isolation of bacterial macrocolonies for biochemical or genetic characterization, which takes a few days and is labor-intensive. In this study, we show that the real-time object detection and classification algorithm You Only Look Once version 4 (YOLOv4) can accurately identify the presence of E. coli at the microcolony stage after a 3-h cultivation. Integrating with phase-contrast microscopic imaging, YOLOv4 discriminated E. coli from seven other common foodborne bacterial species with an average precision of 94%. This approach also enabled the rapid quantification of E. coli concentrations over 3 orders of magnitude with an R2 of 0.995. For romaine lettuce spiked with E. coli (10 to 103 CFU/g), the trained YOLOv4 detector had a false-negative rate of less than 10%. This approach accelerates analysis and avoids manual result determination, which has the potential to be applied as a rapid and user-friendly bacterial sensing approach in food industries. IMPORTANCE A simple, cost-effective, and rapid method is desired to identify potential pathogen contamination in food products and thus prevent foodborne illnesses and outbreaks. This study combined artificial intelligence (AI) and optical imaging to detect bacteria at the microcolony stage within 3 h of inoculation. This approach eliminates the need for time-consuming culture-based colony isolation and resource-intensive molecular approaches for bacterial identification. The approach developed in this study is broadly applicable for the identification of diverse bacterial species. In addition, this approach can be implemented in resource-limited areas, as it does not require expensive instruments and significantly trained human resources. This AI-assisted detection not only achieves high accuracy in bacterial classification but also provides the potential for automated bacterial detection, reducing labor workloads in food industries, environmental monitoring, and clinical settings.

Cyclic adenosine 3',5'-monophosphate (cAMP) is a key second messenger in cardiomyocytes responsible for transducing autonomic signals into downstream electrophysiological responses. Previous studies have shown intracellular heterogeneity and compartmentalization of cAMP signaling. However, whether cAMP signaling occurs heterogeneously throughout the intact heart and how this drives sex-dependent functional responses are unknown. Here, we developed and validated a novel cardiac-specific fluorescence resonance energy transfer-based cAMP reporter mouse and a combined voltage-cAMP whole-heart imaging system. We showed that in male hearts, cAMP was uniformly activated in response to pharmacological β-adrenergic stimulation. In contrast, female hearts showed that cAMP levels decayed faster in apical versus basal regions, which was associated with nonuniform action potential changes and notable changes in the direction of repolarization. Apical phosphodiesterase (PDE) activity was higher in female versus male hearts, and PDE inhibition prevented repolarization changes in female hearts. Thus, our imaging approach revealed sex-dependent regional breakdown of cAMP and associated electrophysiological differences.

3D-bioprinted skin-mimicking phantoms with skin colors ranging across the Fitzpatrick scale are reported. These tools can help understand the impact of skin phototypes on biomedical optics. Synthetic melanin nanoparticles of different sizes (70-500 nm) and clusters are fabricated to mimic the optical behavior of melanosome. The absorption coefficient and reduced scattering coefficient of the phantoms are comparable to real human skin. Further the melanin content and distribution in the phantoms versus real human skins are validated via photoacoustic (PA) imaging. The PA signal of the phantom can be improved by: 1) increasing melanin size (3-450-fold), 2) increasing clustering (2-10.5-fold), and 3) increasing concentration (1.3-8-fold). Then, multiple biomedical optics tools (e.g., PA, fluorescence imaging, and photothermal therapy) are used to understand the impact of skin tone on these modalities. These well-defined 3D-bioprinted phantoms may have value in translating biomedical optics and reducing racial bias.

The retina, behind the transparent optics of the eye, is the only neural tissue whose physiology and pathology can be non-invasively probed by optical microscopy. The aberrations intrinsic to the mouse eye, however, prevent high-resolution investigation of retinal structure and function in vivo. Optimizing the design of a two-photon fluorescence microscope (2PFM) and sample preparation procedure, we found that adaptive optics (AO), by measuring and correcting ocular aberrations, is essential for resolving putative synaptic structures and achieving three-dimensional cellular resolution in the mouse retina in vivo. Applying AO-2PFM to longitudinal retinal imaging in transgenic models of retinal pathology, we characterized microvascular lesions with sub-capillary details in a proliferative vascular retinopathy model, and found Lidocaine to effectively suppress retinal ganglion cell hyperactivity in a retinal degeneration model. Tracking structural and functional changes at high-resolution longitudinally, AO-2PFM enables microscopic investigations of retinal pathology and pharmacology for disease diagnosis and treatment in vivo.

The study was aimed to evaluate the performance of a newly developed spectroscopy-based non-invasive and noncontact device (SAMIRA) for the simultaneous measurement of hemoglobin, bilirubin and oxygen saturation as an alternative to the invasive biochemical method of blood sampling. The accuracy of the device was assessed in 4318 neonates having incidences of either anemia, jaundice, or hypoxia. Transcutaneous bilirubin, hemoglobin and blood saturation values were obtained by the newly developed instrument which was corroborated with the biochemical blood tests by expert clinicians. The instrument is trained using Artificial Neural Network Analysis to increase the acceptability of the data. The artificial intelligence incorporated within the instrument determines the disease condition of the neonate. The Pearson's correlation coefficient, r was found to be 0.987 for hemoglobin estimation and 0.988 for bilirubin and blood gas saturation respectively. The bias and the limits of agreement for the measurement of all the three parameters were within the clinically acceptance limit.

Abstract Mouse auditory cortex is composed of six sub-fields: primary auditory field (AI), secondary auditory field (AII), anterior auditory field (AAF), insular auditory field (IAF), ultrasonic field (UF) and dorsoposterior field (DP). Previous studies have examined thalamo-cortical connections in the mice auditory system and learned that AI, AAF, and IAF receive inputs from the ventral division of the medial geniculate body (MGB). However, the functional and thalamo-cortical connections between nonprimary auditory cortex (AII, UF, and DP) is unclear. In this study, we examined the locations of neurons projecting to these three cortical sub-fields in the MGB, and addressed the question whether these cortical sub-fields receive inputs from different subsets of MGB neurons or common. To examine the distributions of projecting neurons in the MGB, retrograde tracers were injected into the AII, UF, DP, after identifying these areas by the method of Optical Imaging. Our results indicated that neuron cells which in ventral part of dorsal MGB (MGd) and that of ventral MGB (MGv) projecting to UF and AII with less overlap. And DP only received neuron projecting from MGd. Interestingly, these three cortical areas received input from distinct part of MGd and MGv in an independent manner. Based on our foundings these three auditory cortical sub-fields in mice may independently process auditory information.

Background: Qualitative and quantitative assessment of retinal perfusion using optical coherence tomography angiography (OCTA) has shown to be effective in the treatment and management of various retinal and optic nerve diseases. However, manual analyses of OCTA images to calculate metrics related to Foveal Avascular Zone (FAZ) morphology, and retinal vascular density and morphology are costly, time-consuming, subject to human error, and are exposed to both inter and intra operator variability.Objective: This study aimed to develop an open-source software framework for quantitative OCTA (QOCTA). Particularly, for analyzing OCTA images and measuring several indices describing microvascular morphology, vessel morphology, and FAZ morphology.Material and Methods: In this analytical study, we developed a toolbox or QOCTA using image processing algorithms provided in MATLAB. The software automatically determines FAZ and measures several parameters related to both size and shape of FAZ including area, perimeter, Feret’s diameter circularity, axial ratio, roundness, and solidity. The microvascular structure is derived from the processed image to estimate the vessel density (VD). To assess the reliability of the software, three independent operators measured the mentioned parameters for the eyes of 21 subjects. The consistency of the values was assessed using the intraclass correlation coefficient (ICC) index.Results: Excellent consistency was observed between the measurements completed for the superficial layer, ICC >0.9. For the deep layer, good reliability in the measurements was achieved, ICC >0.7. Conclusion: The developed software is reliable; hence, it can facilitate quantitative OCTA, further statistical comparison in cohort OCTA studies, and can assist with obtaining deeper insights into retinal variations in various populations.

As a noninvasive, nonradiative and high-speed imaging modality, fluorescence imaging in the second near-infrared window (NIR-II, 1,000-1,700 nm) has demonstrated great potential for biomedical research and clinical study. The NIR-II window can be further divided into two spectral regions: NIR-IIa (1,000-1,300 nm) and NIR-IIb (1,500-1,700 nm). Compared to NIR-IIa, imaging in NIR-IIb region affords high-resolution imaging at subcentimeter tissue depths due to suppressed photon scattering and diminished tissue autofluorescence at long wavelengths, but relies on probes with high toxicity. To address the problem, researchers employ deep learning networks to attain NIR-IIb images from NIR-IIa images. However, current methods require numerous paired or unpaired images (more than 2800 images) as training sets, which can hardly acquire. In this work, an innovative convolutional neural network (BRCycle-GAN) is trained based on a small training set (merely 63 images) to transform NIR-IIa images into images with NIR-IIb imaging qualities. The NIR-IIb images generated by BRCycle-GAN outperform previous network models in terms of peak signal-to-noise ratio, cosine similarity and other image evaluation indices.

Basal cell carcinoma (BCC) is a common type of skin cancer. Conventional approaches to BCC diagnosis often involve invasive histological examinations that can distort or even destroy information derived from the biomolecules in the sample. Therefore, a non-invasive, label-free examination method for the clinical diagnosis of BCC represents a critical advance. This study combined spectral- and time-resolved two-photon microscopy with a spectral phasor to extract rich biochemical information describing macroscopic tumor morphology and microscopic tumor metabolism. The proposed optical imaging technique achieved the rapid and efficient separation of tumor structures in systematic research conducted on normal and BCC human skin tissues. The results demonstrate that a combination of multidimensional data (e.g., fluorescence intensity, spectrum, and lifetime) with a spectral phasor can accurately identify tumor boundaries and achieve rapid separation. This label-free, real-time, multidimensional imaging technique serves as a complement to the conventional tumor diagnostic toolbox and demonstrates significant potential for the early diagnosis of BCC and wider applications in intraoperative auxiliary imaging.

We report on the design and construction of a laser scanning optical beam-induced current (OBIC) microscope by assembling cost-effective commercial optical and electronic hardware components and developing data acquisition and control software in LabVIEW. A preliminary OBIC image of a Si photodetector acquired by the developed microscope is presented to demonstrate its operational capability. The versatility of the design will allow for the construction of other scanning microscope modalities on the same platform.

Paroxysmal atrial fibrillation is a common arrhythmia, and its development process and prediction of the degree of atrial fibrosis are of great significance for treatment and management. Optical imaging technology provides a new means for non-invasive observation of atrial electrical activity. The aim of this study is to investigate the predictive effect of sinus node recovery time on the degree of atrial fibrosis in patients with paroxysmal atrial fibrillation, and to provide a basis for the application of optical imaging technology in the study of atrial fibrosis. The study collected clinical and optical imaging data from a group of patients with paroxysmal atrial fibrillation, and used statistical analysis methods to investigate the relationship between sinus node recovery time and the degree of atrial fibrosis. The research results indicate that there is a significant correlation between the recovery time of the sinus node and the degree of atrial fibrosis, that is, there is a positive correlation between the prolonged recovery time of the sinus node and the aggravation of atrial fibrosis. SNRT can serve as an effective indicator for evaluating atrial matrix and can be applied to predict recurrence after catheter ablation of paroxysmal atrial fibrillation. Shortening SNRT through catheter ablation can become an important predictor of effective catheter ablation.

BACKGROUND: Understanding the extent of tumor spread to local lymph nodes is critical to managing early-stage gastric cancer. Recently, fluorescence imaging with indocyanine green has been used to identify and characterize sentinel lymph nodes during gastric cancer surgery, but no published guidelines exist. We sought to identify areas of consensus among international experts in the use of fluorescence imaging with indocyanine green for mapping sentinel lymph nodes during gastric-cancer surgery. METHODS: In this 2-round, online Delphi survey, 27 international experts voted on 79 statements pertaining to patient preparation and contraindications to fluorescence imaging with indocyanine green during gastric cancer surgery; indications; technical aspects; advantages/disadvantages and limitations; and training and research. Methodological steps were adopted during survey design to minimize bias. RESULTS: Consensus was reached on 61 of 79 statements, including giving single injections of indocyanine green into each of the 4 quadrants peritumorally, administering indocyanine green on the same day as surgery, injecting a total of 1 to 5 mL of 5 mg/mL indocyanine green, injecting endoscopically into submucosa, and repeating indocyanine green injections a second time if sentinel lymph node visualization remains inadequate. Consensus also was reached that fluorescence imaging with indocyanine green is an acceptable single-agent modality for sentinel lymph node identification and that the sentinel lymph node basin method is preferred. However, sentinel lymph node dissection should be limited to T1 gastric cancer and tumors ≤4 cm in diameter, and further research is necessary to optimize the technique and render fluorescence-guided sentinel lymph nodes dissection acceptable for routine clinical use. CONCLUSION: Although considerable consensus was achieved, further research is necessary before this technology should be used in routine practice.

Genitourinary syndrome of menopause (GSM) negatively affects more than half of postmenopausal women. Energy-based therapy has been explored as a minimally invasive treatment for GSM; however, its mechanism of action and efficacy is controversial. Here, we report on a pilot imaging study conducted on a small group of menopause patients undergoing laser treatment. Intravaginal optical coherence tomography (OCT) endoscope was used to quantitatively monitor the changes in the vaginal epithelial thickness (VET) during fractional-pixel CO2 laser treatment. Eleven patients with natural menopause and one surgically induced menopause patient were recruited in this clinical study. Following the laser treatment, 6 out of 11 natural menopause patient showed increase in both proximal and distal VET, while two natural menopause patient showed increase in VET in only one side of vaginal tract. Furthermore, the patient group that showed increased VET had thinner baseline VET compared to the patients that showed decrease in VET after laser treatment. These results demonstrate the potential utility of intravaginal OCT endoscope in evaluating the vaginal tissue integrity and tailoring vaginal laser treatment on a per-person basis, with the potential to monitor other treatment procedures.

The innate immune system is critical for infection survival. Drosophila melanogaster is a key model for understanding the evolution and dynamics of innate immunity. Current toolsets for fly infection studies are limited in throughput and, because of their destructive nature, cannot generate longitudinal measurements in individual animals. We report a bioluminescent imaging strategy enabling non-invasive characterization of pathogen load. By using Escherichia coli expressing the ilux operon, we demonstrate that photon flux from autobioluminescent bacteria can be used to monitor pathogen loads in individual, living flies. Because animal sacrifice is not necessary to estimate pathogen load, stochastic responses to infection can be characterized in individuals over time. The high temporal resolution of bioluminescence imaging enables visualization of the dynamics of microbial clearance on the hours time-scale. This non-invasive imaging strategy provides a simple and scalable platform to observe changes in pathogen load in vivo over time.

The excited-state lifetime is an intrinsic property of fluorescent molecules that can be leveraged for multiplexed imaging. An advantage of fluorescence lifetime-based multiplexing is that signals from multiple probes can be gathered simultaneously, whereas traditional spectral fluorescence imaging typically requires multiple images at different excitation and emission wavelengths. Additionally, lifetime and spectra could both be utilized to expand the multiplexing capacity of fluorescence. However, resolving exogenous molecular probes based exclusively on the fluorescence lifetime has been limited by technical challenges in analyzing lifetime data. The phasor approach to lifetime analysis offers a simple, graphical solution that has increasingly been used to assess endogenous cellular autofluorescence to quantify metabolic factors. In this study, we employed the phasor analysis of FLIM to quantitatively resolve three exogenous, antibody-targeted fluorescent probes with similar spectral properties based on lifetime information alone. First, we demonstrated that three biomarkers that were spatially restricted to the cell membrane, cytosol, or nucleus could be accurately distinguished using FLIM and phasor analysis. Next, we successfully resolved and quantified three probes that were all targeted to cell surface biomarkers. Finally, we demonstrated that lifetime-based quantitation accuracy can be improved through intensity matching of various probe-biomarker combinations, which will expand the utility of this technique. Importantly, we reconstructed images for each individual probe, as well as an overlay of all three probes, from a single FLIM image. Our results demonstrate that FLIM and phasor analysis can be leveraged as a powerful tool for simultaneous detection of multiple biomarkers with high sensitivity and accuracy.

Mouse auditory cortex is composed of six sub-fields: primary auditory field (AI), secondary auditory field (AII), anterior auditory field (AAF), insular auditory field (IAF), ultrasonic field (UF) and dorsoposterior field (DP). Previous studies have examined thalamo-cortical connections in the mice auditory system and learned that AI, AAF, and IAF receive inputs from the ventral division of the medial geniculate body (MGB). However, the functional and thalamo-cortical connections between nonprimary auditory cortex (AII, UF, and DP) is unclear. In this study, we examined the locations of neurons projecting to these three cortical sub-fields in the MGB, and addressed the question whether these cortical sub-fields receive inputs from different subsets of MGB neurons or common. To examine the distributions of projecting neurons in the MGB, retrograde tracers were injected into the AII, UF, DP, after identifying these areas by the method of Optical Imaging. Our results indicated that neuron cells which in ventral part of dorsal MGB (MGd) and that of ventral MGB (MGv) projecting to UF and AII with less overlap. And DP only received neuron projecting from MGd. Interestingly, these three cortical areas received input from distinct part of MGd and MGv in an independent manner. Based on our foundings these three auditory cortical sub-fields in mice may independently process auditory information. [ABSTRACT FROM AUTHOR]

Imaging is increasingly used to capture information on the marine environment thanks to the improvements in imaging equipment, devices for carrying cameras and data storage in recent years. In that context, biologists, geologists, computer specialists and end-users must gather to discuss the methods and procedures for optimising the quality and quantity of data collected from images. The 4 Marine Imaging Workshop was organised from 3-6 October 2022 in Brest (France) in a hybrid mode. More than a hundred participants were welcomed in person and about 80 people attended the online sessions. The workshop was organised in a single plenary session of presentations followed by discussion sessions. These were based on dynamic polls and open questions that allowed recording of the imaging community's current and future ideas. In addition, a whole day was dedicated to practical sessions on image analysis, data standardisation and communication tools. The format of this edition allowed the participation of a wider community, including lowerincome countries, early career scientists, all working on laboratory, benthic and pelagic imaging. This article summarises the topics addressed during the workshop, particularly the outcomes of the discussion sessions for future reference and to make the workshop results available to the open public. [ABSTRACT FROM AUTHOR]

Metal halide perovskites are widely used in the preparation of photodetectors (PDs) due to their excellent photoelectric properties, tunable band gap, low cost, and rapid processing in solutions. Although 3D perovskite PDs exhibit exceptional performance, their practical applications are limited due to instability issues. Conversely, 2D perovskite PDs are gaining popularity due to their superior environmental stability. To produce efficient and stable perovskite‐based PDs, it is crucial to control the film formation process to achieve high‐quality perovskite films. This paper examines the impacts of perovskite film preparation process and crystallinity on the photoelectric properties of PDs and presents important observations regarding the crystallization and phase dynamics that occur during perovskite film formation. These insights have practical implications on the design and preparation of high‐performance and stable metal halide perovskite photodetectors, particularly in the domains of optical communications and imaging. They offer valuable guidance for next researchers and developers seeking to improve the functionality and marketability of photodetectors using perovskite films. [ABSTRACT FROM AUTHOR]

The method of common lines is a well-established reconstruction technique in cryogenic electron microscopy (cryo-EM), which can be used to extract the relative orientations of an object given tomographic projection images from different directions. In this paper, we deal with an analogous problem in optical diffraction tomography. Based on the Fourier diffraction theorem, we show that rigid motions of the object, i.e., rotations and translations, can be determined by detecting common circles in the Fourier-transformed data. We introduce two methods to identify common circles. The first one is motivated by the common line approach for projection images and detects the relative orientation by parameterizing the common circles in the two images. The second one assumes a smooth motion over time and calculates the angular velocity of the rotational motion via an infinitesimal version of the common circle method. Interestingly, using the stereographic projection, both methods can be reformulated as common line methods, but these lines are, in contrast to those used in cryo-EM, not confined to pass through the origin and allow for a full reconstruction of the relative orientations. Numerical proof-of-the-concept examples demonstrate the performance of our reconstruction methods. [ABSTRACT FROM AUTHOR]

Optical-based imaging has improved from early single-location research to further sophisticated imaging in 2D topography and 3D tomography. These techniques have the benefit of high specificity and non-radiative safety for brain detection and therapy. However, their performance is limited by complex tissue structures. To overcome the difficulty in successful brain imaging applications, we conducted a simulation using 16 optical source types within a brain model that is based on the Monte Carlo method. In addition, we propose an evaluation method of the optical propagating depth and resolution, specifically one based on the optical distribution for brain applications. Based on the results, the best optical source types were determined in each layer. The maximum propagating depth and corresponding source were extracted. The optical source propagating field width was acquired in different depths. The maximum and minimum widths, as well as the corresponding source, were determined. This paper provides a reference for evaluating the optical propagating depth and resolution from an optical simulation aspect, and it has the potential to optimize the performance of optical-based techniques. [ABSTRACT FROM AUTHOR]

With the continuous development of biomedical imaging technologies such as computed tomography, laser scanning confocal microscopy and ultrasonic imaging, biomedical imaging plays an increasingly obvious role in this field and becomes an important means of biological research and clinical medicine diagnosis and treatment. The purpose of the study was to analyze the application of optical imaging in the medical diagnosis of endometriosis, and to explore the effect of drug therapy on the disease. The changes in serum VEGF and MMP-9 levels in endometriosis and their potential clinical significance were also investigated. This study mainly analyzes and compares the efficacy of Sanjie Zhentong capsule combined with norethisterone tablets in the treatment of endometriosis and the effect on serum VEGF, MMP-9 and sICAM-1 levels. The total effective rate of patients in group B after this combined intervention was 91.07% (51/56), which was more significant compared with 75.0% (39/52) of patients in group A. The curative effect of the included patients in the two groups was significant. After intervention, the VEGF (193.62 ± 45.45), MMP-9 (197.34 ± 22.63), and sICAM-1 (323.58 ± 8.52) indexes of patients in group A were compared with those of patients in group B (121.45 ± 34.78), MMP-9 (128.56 ± 15.86), sICAM-1 (264.87 ± 7.62). The results show that it has high safety and fewer clinical adverse symptoms. Through optical imaging technology, patients with endometriosis are accurately diagnosed and the extent and location of their lesions are observed, helping doctors to provide accurate diagnosis and treatment recommendations. [ABSTRACT FROM AUTHOR]

A real-time 3-D spatial localization system to track an unmanned aerial vehicle (UAV) using a single off-board conventional camera and an onboard circle-shaped colored light-emitting diode (LED) marker is presented. The image from the camera is color-segmented and then morphologically closed before being sent to the ellipse detector. The location of the drone is then estimated with geometric/optical calculations using the pixel coordinates provided by the real-time ellipse detector. The location data generated by this system was validated by a motion-capture system (MCS) that was simultaneously tracking the system in real time. The average position error was of 6 cm, while the processing speed achieved 15 locations/s, which are comparable with recent research references. The usage of a low-cost camera makes this method promising for most mobile UAV tracking applications. [ABSTRACT FROM AUTHOR]

Under the fixed light source intensity (LSI), eggshell thickness difference results in excessive exposure or darkening in imaging, which affects the accuracy of crack identification. To optimize it, a solution involves the utilization of an innovative adaptive light source for optical imaging is proposed. A multi function station is adopted. Among them, one station serves as a reference workstation is utilized to obtain the average grayscale value of the eggs image. The other sub stations serve as detection workstations to acquire and detect the panoramic images of the eggshell. By using the red component average grayscale as a reference to adjust the LSI in the remaining sub stations, imaging consistency is effectively. Moreover, a dual threshold segmentation algorithm was developed to attenuate the dark spot, thereby improving crack detection. Experiments results demonstrating the proposed method significantly improving the detection accuracy of non microcracked eggs while achieving approximately 90% and 92% detection accuracy for intact and cracked eggs, respectively. Practical Applications: There are a few studies on the consistency of light for eggs, and in actual online detection, the light source is often set to a fixed light intensity value, which can lead to overexposure or over‐darkening of the egg image due to variations in the eggshell thickness, and both overexposed and over‐darkened images will result in decreased accuracy of crack recognition. This study designed and built an online detection system for eggshell cracks based on variable light intensity. Therefore, the system not only can help to improve the crack recognition rate of poultry eggs and improve their quality but also would help to promote the development of the commercialization of poultry eggs, which has a broad application prospect. [ABSTRACT FROM AUTHOR]

Medical imaging methods such as optical imaging have advanced significantly in their ability to diagnose and monitor various illnesses without any invasive procedures. Optical imaging offers a detailed view of anatomical structures and molecular processes, utilizing the unique properties of light and its interactions with biological tissues. This paper provides a comprehensive overview of optical imaging principles, including techniques like Optical Coherence Tomography (OCT), fluorescence imaging, and diffuse optical imaging. Optical imaging methods provide non-invasive, detailed views of biological tissues, enabling early disease detection and monitoring, thereby significantly advancing diagnostic capabilities and improving patient outcomes. These methods are used in the detection of diseases such as cancer, cardiovascular conditions, and neurological disorders. [ABSTRACT FROM AUTHOR]

Near‐infrared (NIR) light is well‐suited for the optical imaging and wireless phototherapy of malignant diseases because of its deep tissue penetration, low autofluorescence, weak tissue scattering, and non‐invasiveness. Rare earth nanoparticles (RENPs) are promising NIR‐responsive materials, owing to their excellent physical and chemical properties. The 4f electron subshell of lanthanides, the main group of rare earth elements, has rich energy‐level structures. This facilitates broad‐spectrum light‐to‐light conversion and the conversion of light to other forms of energy, such as thermal and chemical energies. In addition, the abundant loadable and modifiable sites on the surface offer favorable conditions for the functional expansion of RENPs. In this review, the authors systematically discuss the main processes and mechanisms underlying the response of RENPs to NIR light and summarize recent advances in their applications in optical imaging, photothermal therapy, photodynamic therapy, photoimmunotherapy, optogenetics, and light‐responsive drug release. Finally, the challenges and opportunities for the application of RENPs in optical imaging and wireless phototherapy under NIR activation are considered. [ABSTRACT FROM AUTHOR]

The advance of portable and smart near-infrared (NIR) light sources has sparked significant interest. However, achieving high-performance NIR emission at longer wavelengths remains a formidable challenge. In this study, we prepared broadband NIR phosphors by codoping pyrochlore oxide Y 2 GaSbO 7 (YGSO) with Cr3+ and Yb3+ ions using a conventional high-temperature solid-state reaction. Upon excitation by blue light, YGSO: 0.03Cr3+ exhibited a broadband NIR emission centered at 765 nm with a full width at half maximum (FWHM) of 160 nm. The purposeful incorporation of Yb3+ ions facilitated efficient energy transfer from Cr3+ to Yb3+, resulting in a newly observed NIR emission peak at 970 nm. Notably, the addition of Yb3+ improved the overall thermal quenching resistance owing to its inherent thermal stability. Furthermore, we encapsulated the as-obtained phosphors with commercial blue LED chips to create prototype phosphor-converted light-emitting diodes (pc-LEDs). The Cr3+ and Cr3+-Yb3+ codoped pc-LEDs achieved output powers of 120 mW@660 mA with a photoelectric conversion efficiency of 12.66%@30 mA, and 131.7 mW@1020 mA with a photoelectric conversion efficiency of 13.93%@30 mA, respectively. These broadband NIR pc-LEDs hold promise for optical imaging applications. [ABSTRACT FROM AUTHOR]

Fluorescence image-guided surgery(FIGS) is a new technology in modern surgical practice, which uses nearinfrared fluorescence (NIR) imaging agent to mediate the development of target tissue during surgery as a real-time, non-invasive and high -resolution diagnostic method to provide screen images for surgeons to achieve real-time intraoperative navigation. In gynecological malignant tumors, FIGS can be used to detect sentinel lymph nodes, perform lymphography, indicate tumor boundaries, detect tissue contamination and develop important blood vessels during surgery to evaluate blood supply. Due to the lack of targeting of NIR dye itself, targeted molecular probes combined with fluorescent dyes are being widely developed and used in clinical trials of gynecological malignant tumors. However, the high false positive rate is still the main problem hindering its clinical application. With the continuous development of new fluorescent dyes and imaging systems, FIGS may change the diagnosis and treatment strategy of gynecological malignant tumors and provide new treatment options for surgeons. [ABSTRACT FROM AUTHOR]

A detailed experimental study of ethanol spray swirling flames was performed in an axial bluff body stabilized burner. The characteristics of the non-reacting and reacting sprays were recorded by particle imaging velocimetry (PIV) and planar laser-induced fluorescence (PLIF) of the OH radical. A few typical flames with different structures (outer-side-flame-lifting, stable, and near-blow-off) were compared and analyzed. The parameters of the spray, including the spray half-angle (α) and droplet number density (nd), are quantified, and it has been found the flame structure and stability were strongly correlated with the droplet distribution. Several parameters of the flow field, such as velocity magnitude ( | U | vorticity (ωz), and turbulent kinetic energy (TKE), are quantitively analyzed, and it is observed that the local strain rate rose as the air flow rate increased, which is not conducive to local flame stability. Regarding the flame, quantities such as progress variable (), flame height (Lf), lift–off height (hlf), and symmetry factor (Snd and S) are calculated, and it can be observed that the flame symmetry keeps worsening when approaching blow–off, and the inner flame branch exhibits a worse stabilization than the outer one. Our comprehensive investigations offer a deeper understanding of stable combustion in such two–phase flames. [ABSTRACT FROM AUTHOR]

In this paper, we study wet-etching-assisted with picosecond laser for the fabrication of concave MLA on fused silica. Compared with the previous reports about femtosecond laser, wet-etching-assisted with picosecond laser also has the capability of fabricating high quality concave MLA on fused silica. By controlling the pulse energy of picosecond laser and the wet-etching time, the size and curvature radius of microlens can be readily controlled. The focal length of the concave MLA can be controlled from − 88.13 to − 216.96 μm by wet-etching time. Moreover, the F number can be also controlled from 3.30 to 1.47 by controlling the pulse energy. The lowest surface roughness of the microlens is 36 nm. In addition, the MLAs show good optical performance on optical imaging with uniformity up to 0.96. We believe wet-etching-assisted with picosecond laser can be also applied in the fabrication of other micro-optical elements such as Fresnel zone plate, grating, compound eyes and so on. [ABSTRACT FROM AUTHOR]

With the development of the Internet of Things and artificial intelligence, the functions of football training systems continue to expand to meet the needs of training. Optical imaging technology plays an important role in football training, which can monitor and analyze players' movements and techniques in real time. The aim of this study is to develop an intelligent football training system based on iot optical imaging and sensor data monitoring to improve the skill level of players. The optical imaging equipment and sensors are arranged on the football field, and the movement and technical data of the players are collected. The data are processed and analyzed by computer vision and data analysis algorithms. Finally, the analysis is fed back to the players and coaches. By using the Smart Football training system, players can get their own technical evaluation and feedback in real time, and coaches can better understand the training situation and progress of players. The results show that the intelligent football training system based on the Internet of Things optical imaging and sensor data monitoring is an effective tool to assist players and coaches to improve the training effect and enhance the technical level of players. [ABSTRACT FROM AUTHOR]

Oral cancer is a cancer type that is widely prevalent in low-and middle-income countries with a high mortality rate, and poor quality of life for patients after treatment. Early treatment of cancer increases patient survival, improves quality of life and results in less morbidity and a better prognosis. To reach this goal, early detection of malignancies using technologies that can be used in remote and low resource areas is desirable. Such technologies should be affordable, accurate, and easy to use and interpret. This review surveys different technologies that have the potentials of implementation in primary health and general dental practice, considering global perspectives and with a focus on the population in India, where oral cancer is highly prevalent. The technologies reviewed include both sample-based methods, such as saliva and blood analysis and brush biopsy, and more direct screening of the oral cavity including fluorescence, Raman techniques, and optical coherence tomography. Digitalisation, followed by automated artificial intelligence based analysis, are key elements in facilitating wide access to these technologies, to non-specialist personnel and in rural areas, increasing quality and objectivity of the analysis while simultaneously reducing the labour and need for highly trained specialists. [ABSTRACT FROM AUTHOR]

Spatial-structured longitudinal light beams are optical fields sculpted in three-dimensional (3D) space by diffractive optical elements. These beams have been recently suggested for use in improving several imaging capabilities, such as 3D imaging, enhancing image resolution, engineering the depth of field, and sectioning 3D scenes. All these imaging tasks are performed using coded aperture correlation holography systems. Each system designed for a specific application is characterized by a point spread function of a different spatial-structured longitudinal light beam. This article reviews the topic of applying certain structured light beams for optical imaging. [ABSTRACT FROM AUTHOR]

Significance: Skin color affects light penetration leading to differences in its absorption and scattering properties. COVID-19 highlighted the importance of understanding of the interaction of light with different skin types, e.g., pulse oximetry (PO) unreliably determined oxygen saturation levels in people from Black and ethnic minority backgrounds. Furthermore, with increased use of other medical wearables using light to provide disease information and photodynamic therapies to treat skin cancers, a thorough understanding of the effect skin color has on light is important for reducing healthcare disparities. Aim: The aim of this work is to perform a thorough review on the effect of skin color on optical properties and the implication of variation on optical medical technologies. Approach: Published in vivo optical coefficients associated with different skin colors were collated and their effects on optical penetration depth and transport mean free path (TMFP) assessed. Results: Variation among reported values is significant. We show that absorption coefficients for dark skin are ~6% to 74% greater than for light skin in the 400 to 1000 nm spectrum. Beyond 600 nm, the TMFP for light skin is greater than for dark skin. Maximum transmission for all skin types was beyond 940 nm in this spectrum. There are significant losses of light with increasing skin depth; in this spectrum, depending upon Fitzpatrick skin type (FST), on average 14% to 18% of light is lost by a depth of 0.1 mm compared with 90% to 97% of the remaining light being lost by a depth of 1.93 mm. Conclusions: Current published data suggest that at wavelengths beyond 940 nm light transmission is greatest for all FSTs. Data beyond 1000 nm are minimal and further study is required. It is possible that the amount of light transmitted through skin for all skin colors will converge with increasing wavelength enabling optical medical technologies to become independent of skin color. [ABSTRACT FROM AUTHOR]

Background/aim: The overexpression of HER2 is correlated with poorer outcomes and therapeutic resistance in breast cancer patients. While HER2-targeted therapies have shown improvement, prognosis remains poor for HER2-positive breast cancer patients, and these treatments have limitations. Therefore, it is crucial to explore effective molecular strategies for early detection and treatment of HER2-positive breast cancers. Materials and methods: In this study, we employed the cell-SELEX method to generate a selective aptamer capable of recognizing HER2 in its native conformation within breast cancer cells, for theranostic applications. Utilizing an adherent cell-SELEX approach, we developed and explored a DNA aptamer, named HMAP7, which can specifically target HER2 in the MDA-MB-453 and SK-BR-3 human breast cancer cell lines. After sequencing, the binding affinities of 10 candidate aptamers to HER2 receptors were evaluated by measuring fluorescence intensities within intact cells using near-infrared optical imaging. The dissociation constant of HMAP7 was determined to be in the nanomolar range in both cell lines. Results: The cell-SELEX-derived aptamer sequence, HMAP7 (41-mer), exhibited the highest binding affinity and specificity for HER2. HMAP7 was rapidly internalized into breast cancer cells overexpressing HER2 but showed no uptake in the HER2 receptor-deficient breast cancer cell line MDA-MB-231. Moreover, HMAP7 demonstrated remarkable selectivity for HER2, rendering it suitable for use in complex biological systems. Conclusions: Our findings suggest that the novel DNA aptamer HMAP7 holds promise for both therapeutic and diagnostic applications, enabling selective delivery of therapeutic agents or imaging of HER2-positive breast tumors. [ABSTRACT FROM AUTHOR]

Eccentric, compared to concentric exercise, is proposed to involve different neuro‐motor processing strategies and a higher level of mental demand. This study compared eccentric and concentric cycling at matched perceived effort and torque for the mental demand and related‐cortical activation patterns. Nineteen men (30 ± 6 years) performed four different 5‐min cycling conditions at 30 RPM on a semi‐recumbent isokinetic cycle ergometer: (1) concentric at a moderate perceived effort (23 on the CR100® scale) without torque feedback; (2) concentric and (3) eccentric at the same average torque produced in the first condition; and (4) eccentric at the same moderate perceived effort than the first concentric condition. The conditions two to four were randomized. After each condition, mental demand was monitored using the NASA Task Load Index scale. Changes in oxy‐(O2Hb) and deoxy‐(HHb) hemoglobin during exercise were measured over both prefrontal cortices and the right parietal lobe from a 15‐probe layout using a continuous‐wave NIRS system. Mental demand was significantly higher during eccentric compared to concentric cycling (+52%, p = 0.012) and when the exercise intensity was fixed by the torque rather than the perceived effort (+70%, p < 0.001). For both torque‐ or perceived effort‐matched exercises, O2Hb increased significantly (p < 0.001) in the left and right prefrontal cortices, and right parietal lobe, and HHb decreased in the left, and right, prefrontal cortices during eccentric compared to concentric cycling. This study supports that acute eccentric cycling, compared to concentric cycling, involves a higher mental demand, and frontoparietal network activation. [ABSTRACT FROM AUTHOR]

We present estimated images of a hypothetical satellite system in the presence of Seidel aberrations. We exemplified the effects of defocus, spherical, coma, astigmatism, field curvature, and distortion aberrations. Our analysis methods allow the investigation of aberration effects individually and in any combined form. Thereby, we introduce a potentially rich analysis dimension for the imaging chain, image processing, and image quality analyses. For a number of degrees of aberrations, we provide image estimates, show and quantify how individual (field‐dependent) aberrations would introduce degradations on the satellite images. We got correlation coefficient values for defocus, spherical, coma, astigmatism, field curvature, and distortion aberrations as 0.69, 0.71, 0.66, 0.79, 0.76, and 0.60, respectively. Thereby, we identfied the significance order of Seidel aberrations for this system by using image simulations and image similarity measures. [ABSTRACT FROM AUTHOR]