Sensitive Imaging Research Articles

An image crypt model based on enhanced two-dimensional sine-cosine chaotic map

Sensitive images are being transmitted over insecure media as network and information technology evolve at a rapid pace. As a result, people are becoming more concerned about information security, specifically digital image protection. For securing digital images, numerous image encryption algorithms have been proposed. From that, a chaotic map has been proved a perfect image protection tool as it contains efficient random behaviour. This work proposes a novel two-dimensional sine-cosine map for developing an image cryptosystem. In the developed framework, at first, two random chaotic series are generated by the developed sine-cosine map, then the given image is divided into two blocks, and each block is confused by utilizing different chaotic key series. In the diffusion process, the chaotic series is first changed into integer form, which is applicable for executing some arithmetic operation between chaotic values and image pixels. In the diffusion phase, each confused image block pixel is converted into binary form, and a bit shifting operation is executed depending on the integer form of chaotic series. In the final process, a bit-xor operation is performed between the partial diffused image and chaotic series to obtain the final encrypted image. The proposed model's security strength will be evaluated using statistical and differential attack analysis.

Optical vortex coronagraphy for high-contrast imaging of femtosecond laser filaments

A high-contrast imaging technique for phase objects based on the optical vortex coronagraph (OVC) is proposed. This method offers the unique advantage of background-free imaging due to the introduction of azimuthal phase in the Fourier plane. We employed the OVC method to detect femtosecond laser-induced air plasma and compared it with the classic diffractometry and fluorescent imaging methods. We achieved a phase sensitivity of ∼0.035 waves that surpassed the capabilities of the other two methods. The combination of this highly sensitive imaging technique with the pump–probe method holds promise for applications in ultrafast imaging of laser–material interactions.

Facile, sensitive and reagent-saving smartphone-based digital image colorimetric assay of captopril tablets enabled by long-pathlength RGB acquisition

A new assay of captopril (CTP) tablets was developed based on digital image colorimetry using Ellman’s reagent. For the first time, a facile technique of increasing the analytical path was applied in this work to enhance the sensitivity. For this purpose, the reaction solutions were photographed using a smartphone while they were contained in two 1-cm pathlength cuvettes which were placed side by side. The Red-Green-Blue (RGB) in term of [B/(R+G+B)] was used to plot a standard curve. Compared to using a single cuvette, double cuvettes resulted in more precise analytical signals and better linearity (r2 of 0.9992). Additionally, CTP could be analyzed at low concentrations (2.5–25 µM) with LOD of 0.70 µM and LOQ of 2.13 µM, thus lowering the reagent consumption. The assay was proven to be valid, and it was greener, faster, and more affordable than the pharmacopeial chromatographic method, thereby suitable for pharmaceutical quality control.

Optimization of Radiation Exposure when Examining Patients with Pathology of the Craniovertebral Region

The diagnostics are based on the principle of obtaining informative and high-quality images with minimal radiation exposure using radiation diagnostic methods: traditional radiography, multislice and cone-beam computed tomography.When conducting X-ray examinations, the main factors in reducing the risk of radiation exposure are the use of highly sensitive digital diagnostic image receivers, minimal exposure time, and a minimum number of images per examination. A lower current value and high anode voltage values, a minimum focal spot size, the placement of the tube as far as possible from the patient and the image receiver as close to the patient as possible, collimation of the radiation beam, and preference for a low radiation dose rate mode are also factors in reducing the risk of radiation exposure.Imaging of the craniovertebral region using cone beam computed tomography offers the opportunity to evaluate the bone structure of the region in detail, with an equal or less effective dose to the patient.

Methylammonium-Based Quasi-Two-Dimensional Perovskite Single Crystals for Highly Sensitive X-ray Detection and Imaging.

The strategy of introducing large organic cations into three-dimensional perovskites could reduce the dimensionality of perovskites to form quasi-two-dimensional (quasi-2D) perovskites, resulting in increased stability and reduced detection limits due to less ion migration. Herein, a quasi-2D perovskite single crystal (BDA)(MA)2Pb3Br10 (BDA = NH3C4H8NH3, MA = CH3NH3) with a layered structure was grown by the temperature-cooling solution method. The X-ray detector based on the (BDA)(MA)2Pb3Br10 single crystal has a sensitivity as high as 1984 μC Gy-1 cm-2 at 55.6 V/mm, and it could detect X-rays as low as 28.12 nGy s-1 at 22.2 V/mm. In addition, the X-ray imaging system based on the single-crystal device easily distinguishes between metals and plastics and exhibits a spatial resolution estimated as 250 μm, indicating the feasibility of (BDA)(MA)2Pb3Br10 crystals for X-ray imaging. This research offers a method for the design of quasi-2D layered perovskites and enhances photoelectronic applications in X-ray inspection and imaging.

A new digital image shifting method by considering the geometry of camera sensors

Digital image shifting occurs when the pixels needs to be moved, the algorithm behind this is interpolation. Current digital image shifting algorithm utilizing interpolation has a limitation: it treats all images as the same type of matrix and does not consider how the images are formed this could cause problems in some sensitive imaging scenarios such as microcopy and precision optical metrology. The goal of our research is to propose a new approach to implement the digital image shifting method. We based our new method off of digital camera sensors, specifically the CMOS sensor. When light (a continuous signal) hits the CMOS sensor, the sensor transforms the light into a discrete signal and its energy into electric energy. Then, this discrete signal then generates the pixels of the image. Our algorithm is similar: The signal is convoluted with the rectangular function, generating a continuous signal, and then we multiply the discrete dirac comb function to generate a discrete signal. After that, we only have to manipulate the discrete dirac comb function to obtain the desired result. Our conducted simulations on the computer proves our method correct, hopefully more experiments can be done in the industrial setting.

Chemokine Receptor 2 Targeted PET/CT Imaging Distant Metastases in Pancreatic Ductal Adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive and treatment-refractory malignancies. The lack of an effective screening tool results in the majority of patients being diagnosed at late stages, which underscores the urgent need to develop more sensitive and specific imaging modalities, particularly in detecting occult metastases, to aid clinical decision-making. The tumor microenvironment of PDAC is heavily infiltrated with myeloid-derived suppressor cells (MDSCs) that express C-C chemokine receptor type 2 (CCR2). These CCR2-expressing MDSCs accumulate at a very early stage of metastasis and greatly outnumber PDAC cells, making CCR2 a promising target for detecting early, small metastatic lesions that have scant PDAC cells. Herein, we evaluated a CCR2 targeting PET tracer (68Ga-DOTA-ECL1i) for PET imaging on PDAC metastasis in two mouse models. Positron emission tomography/computed tomography (PET/CT) imaging of 68Ga-DOTA-ECL1i was performed in a hemisplenic injection metastasis model (KI) and a genetically engineered orthotopic PDAC model (KPC), which were compared with 18F-FDG PET concurrently. Autoradiography, hematoxylin and eosin (H&E), and CCR2 immunohistochemical staining were performed to characterize the metastatic lesions. PET/CT images visualized the PDAC metastases in the liver/lung of KI mice and in the liver of KPC mice. Quantitative uptake analysis revealed increased metastasis uptake during disease progression in both models. In comparison, 18F-FDG PET failed to detect any metastases during the time course studies. H&E staining showed metastases in the liver and lung of KI mice, within which immunostaining clearly demonstrated the overexpression of CCR2 as well as CCR2+ cell infiltration into the normal liver. H&E staining, CCR2 staining, and autoradiography also confirmed the expression of CCR2 and the uptake of 68Ga-DOTA-ECL1i in the metastatic foci in KPC mice. Using our novel CCR2 targeted radiotracer 68Ga-DOTA-ECL1i and PET/CT, we demonstrated the sensitive and specific detection of CCR2 in the early PDAC metastases in two mouse models, indicating its potential in future clinical translation.

Discovery and optimization of the first‐in‐class TDP‐43 PET tracer

AbstractBackgroundIntracellular aggregation of TDP‐43 is found in most patients with amyotrophic lateral sclerosis (ALS), 45% of patients with frontotemporal dementia (FTD) and 30‐50% of patients with clinical diagnosis of Alzheimer’s disease. Sensitive fluid or imaging biomarkers of TDP‐43 pathology are currently not available. Direct detection of TDP‐43 aggregates by positron emission tomography (PET) holds promise for a more accurate diagnosis, patient stratification and assessment of therapeutic efficacy in clinical trials.MethodsUsing ACI’s Morphomer® small molecule library focused on brain penetrant and beta sheet binding compounds, initial hits were identified, and iterative medicinal chemistry applied to discover compounds with optimized properties. Radiobinding and autoradiography experiments on FTLD‐TDP brain samples were used to evaluate affinity and target engagement. These techniques were also used to assess selectivity over other aggregation‐prone proteins using brain material from Alzheimer’s (AD) and Parkinson’s disease (PD) cases. Brain pharmacokinetic (PK) profile was obtained in mice, followed by assessment of brain uptake, distribution and washout for selected 18F radiolabeled compounds in non‐human primates (NHP).ResultsSeveral chemical series showing nanomolar binding affinity to aggregated TDP‐43 from patient brain samples were identified. The specificity of binding was further confirmed by high resolution autoradiography enabling visualization of target engagement on TDP‐43 inclusions in FTLD‐TDP brain sections. In addition, the most advanced compounds differentiated FTLD‐TDP from control by classical autoradiography on patient brain sections. Selectivity over amyloid beta, alpha‐synuclein and Tau was observed. The compounds with the most favorable brain penetrantion properties demonstrated fast and substantial brain uptake and fast and complete washout in NHPs.ConclusionsFirst‐in‐class TDP‐43 PET ligands have been discovered with the potential to identify FTLD‐TDP pathology by PET. These tools may finally allow the ability to detect and follow the progression of TDP‐43 pathology in the brains of living patients with certain TDP‐43 proteinopathies.

Elevated Carotid Pulse Wave Velocity is associated with Cognitive Impairment and Cerebral Amyloid Deposition: A Phase‐Contrast MRI Study

AbstractBackgroundPrevious studies have indicated that arterial stiffness could play an important role in the AD pathology. Arterial stiffness is typically measured by pulse wave velocity (PWV) from central and peripheral arteries. Recent work has introduced a two‐minute robust MRI method to measure carotid PWV (cPWV) using a single‐slice oblique‐sagittal phase‐contrast MRI(OS PC‐MRI)[Pahlavian SH et al, JCBFM 2021]. This study aims to evaluate cPWV measured by OS PC‐MRI as a sensitive imaging marker of AD by studying the association of cPWV with cognitive performance and amyloid pathology.MethodTwenty‐three elderly volunteers (13 female, 72.6 ± 7.1 years) participated in the study and underwent cognitive and functional assessments including Clinical Dementia Rating (CDR, n = 23), Mini‐Mental State Exam (MMSE, n = 21), and Montreal Cognitive Assessment (MoCA, n = 23) and F18‐florbetaben amyloid‐PET scans (n = 14). A retrospectively gated single‐slice 2D OS PC‐MRI was performed on each participant at 3T to assess cPWV. The correlations between cPWV vs cognitive measures and cerebral amyloid were calculated across subjects using Pearson or Spearman’s correlation coefficients.ResultTable 1 lists the demographic and clinical information of participants. cPWV showed significant negative correlations with both MoCA (Figure 1a) and MMSE (Figure 1b) (cPWV vs. MoCA: r = ‐0.57, p = 0.0044; cPWV vs. MMSE: r = ‐0.74, p < 0.001;), and correlations remained significant after controlling for age, gender, years of education (cPWV vs. MoCA:r = ‐0.70, p < 0.001; cPWV vs. MMSE: r = ‐0.75, p < 0.001). Participants were further separated into two groups (CRD = 0: n = 12; CDR> = 0.5: n = 11) based on their CDR scores. cPWV values were significantly higher in the group with CDR> = 0.5 without and with correcting for age, sex, and educational level (p = 0.0019, p = 0.015) (Figure 1c). Individuals who presented with amyloid pathology had higher cPWV compared to the ones without amyloid pathology (p = 0.038) (Figure 2), which indicates cPWV may be closely linked to amyloid pathology in AD.ConclusionThis study demonstrates that elevated carotid PWV is associated with cognitive impairment and amyloid pathology in elderly adults. Longitudinal studies are necessary to determine whether cPWV contributes to accumulation of amyloid in brain parenchyma or results from deposition of amyloid in cerebral blood vessels.

Optical photon transport simulations for SiPM based PET scanner

Positrons emitted from radioisotope quickly annihilates to two collinear photons that are captured by the array of scintillator detectors to infer about the origin of radioactivity. Coincidence collection of pair of points from the detector modules makes a line of response, their large number reveals a radioactive region of interest. Most of the medical diagnostic research is conducted with position sensitive imaging device whose performance strongly depends on the optical light collection efficiency. A versatile Lutetium–Yttrium Oxyorthosilicate (LYSO) scintillator is used to mimic the optical photon production and transport processes followed by the light collection with Silicon PhotoMultiplier sensor. Charge spectrum from a 2 × 2 × 10 mm3 single LYSO bar is obtained in GEANT4, and reproduces well the scintillation characteristics of LYSO along with photons incidence angle distribution with a single SiPM pad. This excercise is followed by the simulation performance of two PET modules comprises of 12 × 12 SiPM tile coupled with mesh of LYSO bars. The preliminarly results shows the transverse position resolution (FWHM) as 7.82 mm for a point source. Objective of this study is to search for a cheaper detector solution which will have equivalent imaging performance.

Engineered Glucose Oxidase‐Carbon Nanotube Conjugates for Tissue‐Translatable Glucose Nanosensors

AbstractContinuous and non‐invasive glucose monitoring and imaging is important for disease diagnosis, treatment, and management. However, glucose monitoring remains a technical challenge owing to the dearth of tissue‐transparent glucose sensors. In this study, we present the development of near‐infrared fluorescent single‐walled carbon nanotube (SWCNT) based nanosensors directly functionalized with glucose oxidase (GOx) capable of immediate and reversible glucose imaging in biological fluids and tissues. We prepared GOx‐SWCNT nanosensors by facile sonication of SWCNT with GOx in a manner that—surprisingly—does not compromise the ability of GOx to detect glucose. Importantly, we find by using denatured GOx that the fluorescence modulation of GOx‐SWCNT is not associated with the catalytic oxidation of glucose but rather triggered by glucose‐GOx binding. Leveraging the unique response mechanism of GOx‐SWCNT nanosensors, we developed catalytically inactive apo‐GOx‐SWCNT that enables both sensitive and reversible glucose imaging, exhibiting a ΔF/F0 of up to 40 % within 1 s of exposure to glucose without consuming the glucose analyte. We finally demonstrate the potential applicability of apo‐GOx‐SWCNT in biomedical applications by glucose quantification in human plasma and glucose imaging in mouse brain slices.

Engineered Glucose Oxidase-Carbon Nanotube Conjugates for Tissue-Translatable Glucose Nanosensors.

Continuous and non-invasive glucose monitoring and imaging is important for disease diagnosis, treatment, and management. However, glucose monitoring remains a technical challenge owing to the dearth of tissue-transparent glucose sensors. In this study, we present the development of near-infrared fluorescent single-walled carbon nanotube (SWCNT) based nanosensors directly functionalized with glucose oxidase (GOx) capable of immediate and reversible glucose imaging in biological fluids and tissues. We prepared GOx-SWCNT nanosensors by facile sonication of SWCNT with GOx in a manner that-surprisingly-does not compromise the ability of GOx to detect glucose. Importantly, we find by using denatured GOx that the fluorescence modulation of GOx-SWCNT is not associated with the catalytic oxidation of glucose but rather triggered by glucose-GOx binding. Leveraging the unique response mechanism of GOx-SWCNT nanosensors, we developed catalytically inactive apo-GOx-SWCNT that enables both sensitive and reversible glucose imaging, exhibiting a ΔF/F0 of up to 40 % within 1 s of exposure to glucose without consuming the glucose analyte. We finally demonstrate the potential applicability of apo-GOx-SWCNT in biomedical applications by glucose quantification in human plasma and glucose imaging in mouse brain slices.

Probing star formation in five of the most massive spiral galaxies observed through ASTROSAT UltraViolet Imaging Telescope

ABSTRACT We present highly resolved and sensitive imaging of the five nearby massive spiral galaxies (with rotation velocities $\rm \gt 300\, km\, s^{-1}$) observed by the UltraViolet Imaging Telescope onboard India’s multiwavelength astronomy satellite ASTROSAT, along with other archival observations. These massive spirals show a far-ultraviolet star formation rate in the range of ∼ 1.4 – 13.7 ${\rm M}_{\odot } \, \mathrm{yr}^{-1}$ and fall in the ‘Green Valley’ region with a specific star formation rate within ∼ 10−11.5 – 10−10.5 yr−1. Moreover, the mean star formation rate density of the highly resolved star-forming clumps of these objects is in the range 0.011 – 0.098 ${\rm M}_{\odot }\, \mathrm{ yr}^{-1}\, \mathrm{kpc}^{-2}$, signifying localized star formation. From the spectral energy distributions, under the assumption of a delayed star formation model, we show that the star formation of these objects had peaked in the period of ∼ 0.8 – 2.8 Gyr after the ‘Big Bang’ and the object that has experienced the peak sooner after the ‘Big Bang’ show relatively less star-forming activity at z ∼ 0 and falls below the main-sequence relation for a stellar content of $\rm \gtrsim 10^{11} \, {\rm M}_{\odot }$. We also show that these objects accumulated much of their stellar mass in the early period of evolution with ∼ 31 – 42 per cent of the total stellar mass obtained in a time of (1/16) – (1/5)th the age of the Universe. We estimate that these massive objects convert their halo baryons into stars with efficiencies falling between ∼ 7 and 31 per cent.

A lightweight symmetric image encryption cryptosystem in wavelet domain based on an improved sine map

In the era of big data, the number of images transmitted over the public channel increases exponentially. As a result, it is crucial to devise the efficient and highly secure encryption method to safeguard the sensitive image. In this paper, an improved sine map (ISM) possessing a larger chaotic region, more complex chaotic behavior and greater unpredictability is proposed and extensively tested. Drawing upon the strengths of ISM, we introduce a lightweight symmetric image encryption cryptosystem in wavelet domain (WDLIC). The WDLIC employs selective encryption to strike a satisfactory balance between security and speed. Initially, only the low-frequency-low-frequency component is chosen to encrypt utilizing classic permutation and diffusion. Then leveraging the statistical properties in wavelet domain, Gaussianization operation which opens the minds of encrypting image information in wavelet domain is first proposed and employed to all sub-bands. Simulations and theoretical analysis demonstrate the high speed and the remarkable effectiveness of WDLIC.

The inherent AIE feature revealed the drug molecular state in cyclodextrin metal–organic framework for enhanced stability and absorption

The amorphous form of a drug can greatly improve the solubility and rates of dissolution for enhancing oral bioavailability. However, amorphous drugs tend to crystallize thus negating their solubility advantages. Here, we use a nanoconfinement strategy to prevent the crystallization of amorphous solids by loading the poorly soluble drug indomethacin (IMC) into a porous γ-cyclodextrin-based metal–organic framework (CD-MOF). The inherent aggregation-induced emission (AIE) property of IMC was successfully applied as a sensitive fluorescence imaging tool to visualize its molecular state in the solid form. A distinct high-energy, non-aggregated molecular state of IMC in CD-MOF was revealed by the AIE turn-off phenomenon together with other solid-state characterization methods. The IMC@CD-MOF exhibited excellent physical stability even when stored at high temperature or humidity. The high supersaturated drug solutions were immediately generated and maintained during the dissolution of IMC@CD-MOF, resulting in a great enhancement of in vivo bioavailability. The inherent AIE feature of drugs can facilitate the understanding of the structure–property relationship in complex delivery systems, which is essential for the design and optimization of drug carriers with desired stability and biopharmaceutical performance.

Azo Reductase Activated Magnetic Resonance Tuning Probe with "Switch-On" Property for Specific and Sensitive Tumor Imaging in Vivo.

Cancer remains a threat to human health. However, if tumors can be detected in the early stage, then the effectiveness of cancer treatment could be significantly improved. Therefore, it is worthwhile to develop more sensitive and accurate cancer diagnostic methods. Herein, we demonstrated an azo reductase (AzoR)-activated magnetic resonance tuning (MRET) probe with a "switch-on" property for specific and sensitive tumor imaging in vivo. Specifically, Gd-labeled DNA1 (DNA1-Gd) and cyclodextrin-coated magnetic nanoparticles (MNP-CD) were employed as enhancer and quencher of MRET, respectively, while DNA2, an azobenzene (Azo) group-modified aptamer (AS1411), served as a linker between enhancer and quencher to construct the MRET probe of MNP@DNA(1-2)-Gd. In tumor tissues with high-level AzoR, the T1-weighted magnetic resonance signal of the MRET probe could be restored by intelligently regulating the switch from "OFF" to "ON" after activation with AzoR, thus accurately indicating the location of the tumor accurately. Moreover, the tumor with a 4 times smaller size than that of the normal tumor model could be imaged based on the proposed MRET probe. The as-proposed MRET-based magnetic resonance imaging strategy not only achieves tumor imaging accurately but also shows promise for early diagnosis of tumors, which might improve patients' survival rates and provide an opportunity for image-guided biomedical applications in the future.

A novel feedback catalytic hairpin assembly strategy for sensitive mRNA imaging in living cells

Achieving specific and sensitive imaging of mRNA in living cells plays a key role in cancer diagnosis and treatment. Catalytic hairpin assembly (CHA) has been widely used for mRNA imaging. However, it has been significantly constrained by limited in-depth amplifications. Herein, a novel feedback catalytic hairpin assembly (FCHA) with exponential amplification efficiency was proposed for mRNA imaging in living cells. The FCHA system consisted of with two hairpin DNAs (H1, H2) and a double stranded DNA (H3L). After the probes enter the cell by using β-FeOOH nanoparticles (NPs) as delivery vector, the intracellular target Tk1 mRNA acted as catalyst to trigger the FCHA between H1, H2 and H3L, which achieved the exponential growth of CHA product. This FCHA system has demonstrated improved reaction kinetics and sensitivity compared to traditional CHA, which was 106 times more sensitive than conventional CHA. This strategy can be used for real-time imaging and indication of changes in the mRNA expression. This strategy slao can distinguish the expression difference of mRNA in normal and tumor cells, and can evaluate the anti-tumor drug’s efficacy. Benefiting from these outstanding advantages, we believe that this FCHA will become a powerful tool for early cancer diagnosis.

Spatially Resolved Co-Imaging of Polyhalogenated Xenobiotics and Endogenous Metabolites Reveals Xenobiotic-Induced Metabolic Alterations.

A large group of polyhalogenated compounds has been added to the list of persistent organic pollutants in a global convention endorsed by over 100 nations. Once entering the biotas, these pollutants are transported to focal sites of toxicological action and affected endogenous metabolites, which exhibited distinct tissue or organ distribution patterns. However, no study is available to achieve simultaneous mapping of the spatial distributions of xenobiotics and endogenous metabolites for clarifying the molecular mechanism of toxicities. Herein, we present a sensitive mass spectrometry imaging method─tetraphenyl phosphonium chloride-enhanced ionization coupled with air flow-assisted ionization-Orbitrap mass spectrometry─which simultaneously determined the spatial distributions of polyhalogenated xenobiotics and endogenous metabolites. The spatially resolved toxicokinetics and toxicodynamics of typical polyhalogenated compounds (chlorinated paraffins (CPs) and hexabromocyclododecane (HBCD)) were assessed in zebrafish. Co-imaging of polyhalogenated compounds and metabolites visualized the major accumulation organs and maternal transfer of HBCD and CPs, and it clarified the reproductive toxicity of HBCD. CPs were accumulated in the liver, heart, and brain and decreased the concentrations of polyamine/inosine-related metabolites and lipid molecules in these organs. HBCD accumulated in the ovary and was effectively transferred to eggs, and it also disrupted normal follicular development and impaired the production of mature eggs from the ovary by inhibiting expressions of the luteinizing hormone/choriogonadotropin receptor gene. The toxic effects of metabolic disruptions were validated by organ-specific histopathological examinations. These results highlight the necessity to assess the distributions and bioeffects of pollutants in a spatial perspective.

(Mis)Matching Metadata: Improving Accessibility in Digital Visual Archives through the EyCon Project

Discussing the current AHRC/LABEX-funded EyCon (Early Conflict Photography 1890–1918 and Visual AI) project, this article considers potentially problematic metadata and how it affects the accessibility of digital visual archives. The authors deliberate how metadata creation and enrichment could be improved through Artificial Intelligence (AI) tools and explore the practical applications of AI-reliant tools to analyze a large corpus of photographs and create or enrich metadata. The amount of visual data created by digitization efforts is not always followed by the creation of contextual metadata, which is a major problem for archival institutions and their users, as metadata directly affects the accessibility of digitized records. Moreover, the scale of digitization efforts means it is often beyond the scope of archivists and other record managers to individually assess problematic or sensitive images and their metadata. Additionally, existing metadata for photographic and visual records are presenting issues in terms of outdated descriptions or inconsistent contextual information. As more attention is given to the creation of accessible digital content within archival institutions, we argue that too little is being given to the enrichment of record data. In this article, the authors ask how new tools can address incomplete or inaccurate metadata and improve the transparency and accessibility of digital visual records.

Palladium-free chemoselective probe for in vivo fluorescence imaging of carbon monoxide

Carbon monoxide (CO) is a vital intracellular gas messenger known for its cytoprotective and homeostatic properties. It plays a pivotal role in a myriad of biological processes. Therefore, the precise detection of CO is of paramount importance in unraveling the intricacies of pathological mechanisms and advancing the development of disease diagnosis. We herein introduce NFCOP, a state-of-the-art near-infrared (NIR) turn-on fluorescence (FL) probe that has been meticulously designed for highly sensitive, swift and selective imaging of CO. The NFCOP response occurred rapidly with CO, within just 10 s, and the calculated detection limit for CO was determined to be 0.32 µmol/L. Further investigations conducted at the cellular level and in vivo demonstrated that NFCOP possesses high sensitivity and selectivity for imaging CO.