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Atomic-scale spectroscopic imaging of sputtered magnetic tunnel junction structures with a thick oxygen-rich MgO barrier reveals the diffusion of iron and cobalt into the MgO barrier from CoFeB electrodes. First principles calculations are performed to (1) confirm that Fe diffusion through Mg vacancies is energetically favorable, (2) quantify the reduction of interfacial perpendicular magnetic anisotropy due to Fe diffusion into MgO, and (3) predict that the presence of Fe impurities in MgO causes an increased leakage and a tunneling magnetoresistance decrease. Through the chemical shift of the Fe L3 edge and the peak ratio Fe L3/Fe L2 measured by electron energy loss spectroscopy, we suggest that, within MgO, iron with mixed oxidation state Fe2+ and Fe3+ or higher is found in the as-grown structure, which is reduced by annealing to Fe2+. These results indicate that the stoichiometry of as-deposited MgO barrier layers plays an important role in controlling the microstructure and optimizing the performance of magnetic tunnel junctions. [ABSTRACT FROM AUTHOR]

We present in this paper an analysis of near-infrared observations of the 0.3- |${\rm M}_{\odot }$| protostar V347 Aurigae (V347 Aur) collected with the SPIRou high-resolution spectropolarimeter and velocimeter at the 3.6-m Canada-France-Hawaii Telescope from 2019 October to 2023 April. From a set of 79 unpolarized and circularly polarized spectra of V347 Aur to which we applied Least-Squares Deconvolution (LSD), we derived radial velocities and longitudinal fields, along with their temporal variations over our monitoring campaign of 1258 d. Our data show that V347 Aur is an eccentric binary system with an orbital period of |$154.6\pm 0.7$| d, experiencing strong-to-extreme accretion events near periastron. The companion is a |$29.0\pm 1.6$| |${\rm M}_{{2\!\!_{\mathbf +}}}$| brown dwarf, a rare member of the brown dwarf desert of close companions around M dwarfs. We detect weak longitudinal fields (⁠|$\lt $| 100 G) at the surface of V347 Aur, significantly weaker than those of more evolved prototypical T Tauri stars. These fields show small-amplitude rotational modulation, indicating a mainly axisymmetric parent large-scale magnetic topology, and larger fluctuations at half the orbital period, suggesting that what we dub a 'pulsed dynamo' triggered by orbital motion and pulsed accretion operates in V347 Aur. Applying Zeeman–Doppler imaging to our circularly polarized LSD profiles, we find that the large-scale field of V347 Aur is mainly toroidal for most of our observations, with the toroidal component switching sign near periastron and apoastron. The weak large-scale dipole (⁠|$\simeq 30$| G) is not able to disrupt the disc beyond 1.3 |$R_{\star }$| even at the lowest accretion rates, implying longitudinally distributed (rather than localized) accretion at the surface of the protostar. [ABSTRACT FROM AUTHOR]

The understanding of the optical characteristics and the influence of thermally induced crystallization is vital to evaluate newly synthesized organic semiconductors for their potential applications. Variable‐angle spectroscopic ellipsometry (VASE) is employed to determine the complex dielectric function of two recently developed discrete oligomers based on naphthalene diimide (NDI) and bithiophene (T2), applying an anisotropic optical model. It is shown that the as‐cast films are optically near‐isotropic, while the annealed films exhibit pronounced anisotropies with respect to the orientation of the π−π* transition. Differences between the two distinct molecules are observed and discussed. The degree of optical anisotropy is quantified using the average molecular orientation angle φ, associated with the orientation of the π−π* transition dipole, and the related orientation order parameter S. The molecules are shown to form crystallites of several microns in size upon annealing. Imaging ellipsometry is thus additionally employed to study their optical anisotropy on a microscopic scale, and the agreement with results from macroscopic measurements is evaluated. [ABSTRACT FROM AUTHOR]

Single-molecule localization microscopy (SMLM) surpasses the diffraction limit by randomly switching fluorophores between fluorescent and dark states, precisely pinpointing the resulted isolated emission patterns, thereby reconstructing the super-resolution images based on the accumulated locations of thousands to millions of single molecules. This technique achieves a ten-fold improvement in resolution, unveiling the intricate details of molecular activities and structures in cells and tissues. Multicolor SMLM extends this capability by imaging distinct protein species labeled with various fluorescent probes, providing insights into structural intricacies and spatial relationships among different targets. This review explores recent advancements in multicolor SMLM, evaluates the strengths and limitations of each variant, and discusses the future prospects. [ABSTRACT FROM AUTHOR]

Purpose: To develop a practical method to enable 3D T1 mapping of brain metabolites. Theory and Methods: Due to the high dimensionality of the imaging problem underlying metabolite T1 mapping, measurement of metabolite T1 values has been currently limited to a single voxel or slice. This work achieved 3D metabolite T1 mapping by leveraging a recent ultrafast MRSI technique called SPICE (spectroscopic imaging by exploiting spatiospectral correlation). The Ernst‐angle FID MRSI data acquisition used in SPICE was extended to variable flip angles, with variable‐density sparse sampling for efficient encoding of metabolite T1 information. In data processing, a novel generalized series model was used to remove water and subcutaneous lipid signals; a low‐rank tensor model with prelearned subspaces was used to reconstruct the variable‐flip‐angle metabolite signals jointly from the noisy data. Results: The proposed method was evaluated using both phantom and healthy subject data. Phantom experimental results demonstrated that high‐quality 3D metabolite T1 maps could be obtained and used for correction of T1 saturation effects. In vivo experimental results showed metabolite T1 maps with a large spatial coverage of 240 × 240 × 72 mm3 and good reproducibility coefficients (< 11%) in a 14.5‐min scan. The metabolite T1 times obtained ranged from 0.99 to 1.44 s in gray matter and from 1.00 to 1.35 s in white matter. Conclusion: We successfully demonstrated the feasibility of 3D metabolite T1 mapping within a clinically acceptable scan time. The proposed method may prove useful for both T1 mapping of brain metabolites and correcting the T1‐weighting effects in quantitative metabolic imaging. [ABSTRACT FROM AUTHOR]

Purpose: To characterize the dependence of Xe‐MRI gas transfer metrics upon age, sex, and lung volume in a group of healthy volunteers. Methods: Sixty‐five subjects with no history of chronic lung disease were assessed with 129Xe‐MRI using a four‐echo 3D radial spectroscopic imaging sequence and a dose of xenon titrated according to subject height that was inhaled from a lung volume of functional residual capacity (FRC). Imaging was repeated in 34 subjects at total lung capacity (TLC). Regional maps of the fractions of dissolved xenon in red blood cells (RBC), membrane (M), and airspace (Gas) were acquired at an isotropic resolution of 2 cm, from which global averages of the ratios RBC:M, RBC:Gas, and M:Gas were computed. Results: Data from 26 males and 36 females with a median age of 43 y (range: 20–69 y) were of sufficient quality to analyze. Age (p = 0.0006) and sex (p < 0.0001) were significant predictors for RBC:M, and a linear regression showed higher values and steeper decline in males: RBC:M(Males) = −0.00362 × Age + 0.60 (p = 0.01, R2 = 0.25); RBC:M(Females) = −0.00170 × Age + 0.44 (p = 0.02, R2 = 0.15). Similarly, age and sex were significant predictors for RBC:Gas but not for M:Gas. RBC:M, M:Gas and RBC:Gas were significantly lower at TLC than at FRC (plus inhaled volume), with an average 9%, 30% and 35% decrease, respectively. Conclusion: Expected age and sex dependence of pulmonary function concurs with 129Xe RBC:M imaging results, demonstrating that these variables must be considered when reporting Xe‐MRI metrics. Xenon doses and breathing maneuvers should be controlled due to the strong dependence of Xe‐MRI metrics upon lung volume. [ABSTRACT FROM AUTHOR]

In this work, echo-planar spectroscopic imaging (EPSI) with flyback readout gradient-echo train was implemented in a preclinical MR scanner. The aim of this study is to visualize and quantify the ghost spectral lines produced by two, three and four interleaved echo trains with different amplitudes of the readout gradients, and to investigate the feasibility of the flyback data acquisition in micro-imaging of small animals. Applied multi-slice EPSI sequence utilizes asymmetric gradient-echo train that combines the shortest possible rewind gradients with readout gradients. It simplifies data processing because all echoes are acquired with the same polarity of the readout gradient. The approach with four interleaved gradient-echo trains and with four echoes in each train provides broad spectral bandwidth in combination with narrow receiver bandwidth and a good water-fat signal separation. It improves signal-to-noise ratio without the undesired consequence of water-fat shift artifacts that are eliminated during data processing. Position, number, and intensity of the ghost spectral lines can be controlled by the suitable choice of spectral bandwidth, number of echo train interleaves, and the number of echoes in each interleave. This study demonstrates that high-spatial resolution EPSI with interleaved flyback readout gradient-echo trains is feasible on standard preclinical scanners. [ABSTRACT FROM AUTHOR]

Organoid tumor models have emerged as a powerful tool in the fields of biology and medicine as such 3D structures grown from tumor cells recapitulate better tumor characteristics, making these tumoroids unique for personalized cancer research. Assessment of their functional behavior, particularly protein secretion, is of significant importance to provide comprehensive insights. Here, a label‐free spectroscopic imaging platform is presented with advanced integrated optofluidic nanoplasmonic biosensor that enables real‐time secretion analysis from single tumoroids. A novel two‐layer microwell design isolates tumoroids, preventing signal interference, and the microarray configuration allows concurrent analysis of multiple tumoroids. The dual imaging capability combining time‐lapse plasmonic spectroscopy and bright‐field microscopy facilitates simultaneous observation of secretion dynamics, motility, and morphology. The integrated biosensor is demonstrated with colorectal tumoroids derived from both cell lines and patient samples to investigate their vascular endothelial growth factor A (VEGF‐A) secretion, growth, and movement under various conditions, including normoxia, hypoxia, and drug treatment. This platform, by offering a label‐free approach with nanophotonics to monitor tumoroids, can pave the way for new applications in fundamental biological studies, drug screening, and the development of therapies. [ABSTRACT FROM AUTHOR]

Broadband Coherent Anti-Stokes Raman Scattering (BCARS) is a valuable spectroscopic imaging tool for visualizing cellular structures and lipid distributions in biomedical applications. However, the inevitable biological changes in the samples (cells/tissues/lipids) introduce spectral variations in BCARS data and make analysis challenging. In this work, we conducted a systematic study to estimate the biological variance in BCARS data of two commonly used cell lines (HEK293 and HepG2) in biomedical research. The BCARS data were acquired from two different experimental setups (Leibniz Institute of Photonics Technology (IPHT) in Jena and Politecnico di Milano (POLIMI) in Milano) to evaluate the reproducibility of results. Also, spontaneous Raman data were independently acquired at POLIMI to validate those results. First, Kramers–Kronig (KK) algorithm was utilized to retrieve Raman-like signals from the BCARS data, and a pre-processing pipeline was subsequently used to standardize the data. Principal component analysis – Linear discriminant analysis (PCA-LDA) was performed using two cross-validation (CV) methods: batch-out CV and 10-fold CV. Additionally, the analysis was repeated, considering different spectral regions of the data as input to the PCA-LDA. Finally, the classification accuracies of the two BCARS datasets were compared with the results of spontaneous Raman data. The results demonstrated that the CH band region (2770–3070 cm−1) and spectral data in the 1500–1800 cm−1 region have significantly contributed to the classification. A maximum of 100% balanced accuracies were obtained for the 10-fold CV for both BCARS setups. However, in the case of batch-out CV, it is 92.4% for the IPHT dataset and 98.8% for the POLIMI dataset. This study offers a comprehensive overview for estimating biological variance in biomedical applications. The insights gained from this analysis hold promise for improving the reliability of BCARS measurements in biomedical applications, paving the way for more accurate and meaningful spectroscopic analyses in the study of biological systems. [ABSTRACT FROM AUTHOR]

Significance: Esophageal cancer is becoming increasingly prevalent in Western countries. Early detection is crucial for effective treatment. Multimodal imaging combining optical coherence tomography (OCT) with complementary optical imaging techniques may provide enhanced diagnostic capabilities by simultaneously assessing tissue morphology and biochemical content. Aim: We aim to develop a tethered capsule endoscope (TCE) that can accommodate a variety of point-scanning techniques in addition to OCT without requiring design iterations on the optical or mechanical design. Approach: We propose a TCE utilizing exclusively reflective optics to focus and steer light from and to a double-clad fiber. Specifically, we use an ellipsoidal mirror to achieve finite conjugation between the fiber tip and the imaging plane. Results: We demonstrate a functional all-reflective TCE. We first detail the design, fabrication, and assembly steps required to obtain such a device. We then characterize its performance and demonstrate combined OCT at 1300 nm and visible spectroscopic imaging in the 500- to 700-nm range. Finally, we discuss the advantages and limitations of the proposed design. Conclusions: An all-reflective TCE is feasible and allows for achromatic highquality imaging. Such a device could be utilized as a platform for testing various combinations of modalities to identify the optimal candidates without requiring design iterations. [ABSTRACT FROM AUTHOR]

Aims This study aims to assess the potential bacterial inactivation pathway triggered by argon (Ar) cold atmospheric pressure plasma jet (CAPJ) discharge using spectroscopic and imaging techniques. Methods and results Electrical and reactive species of the Ar CAPJ discharge was characterized. The chemical composition and morphology of bacteria pre- and post-CAPJ exposure were assessed using Fourier transform infrared (FTIR), Raman micro-spectroscopy, and transmission electron microscopy (TEM). A greater than 6 log reduction of Escherichia coli and Staphylococcus aureus was achieved within 60 and 120 s of CAPJ exposure, respectively. Extremely low D- values (<20 s) were recorded for both the isolates. The alterations in the FTIR spectra and Raman micro-spectra signals of post-CAPJ exposed bacteria revealed the degree of destruction at the molecular level, such as lipid peroxidation, protein oxidation, bond breakages, etc. Further, TEM images of exposed bacteria indicated the incurred damages on cell morphology by CAPJ reactive species. Also, the inactivation process varied for both isolates, as evidenced by the correlation between the inactivation curve and FTIR spectra. It was observed that the identified gas-phase reactive species, such as Ar I, O I, OH•, NO+, OH+, NO2−, NO3−, etc. played a significant role in bacterial inactivation. Conclusions This study clearly demonstrated the effect of CAPJ exposure on bacterial cell morphology and molecular composition, illuminating potential bacterial inactivation mechanisms. [ABSTRACT FROM AUTHOR]

Sophisticated tools such as computer vision techniques in combination with 1D lineout type analyses have been used in automating the analysis of spectral data for high energy density (HED) plasmas. Standardized automation can solve the problems posed by the complexity of HED spectra and the quantity of data. We present a spectroscopic code written for automated and streamlined analysis of spatially resolved x-ray absorption data from the COAX platform on Omega-60. COAX uses radiographs and spectroscopic diagnostics to provide shock position and density information. We also obtain the more novel spectral-derived spatial profile of the supersonic radiation flow into a low-density foam. Considerable effort has been spent modernizing our previous spectroscopic analysis method, including the development of new tools characterized by a faster runtime and minimal user input to reduce bias and a testing suite for verifying the accuracy of the various functions within the code. The new code analyzes our spectroscopic images in 1–2 min, with added uncertainty and confidence. [ABSTRACT FROM AUTHOR]

Purpose: Demonstrate the feasibility and evaluate the performance of single‐shot diffusion trace‐weighted radial echo planar spectroscopic imaging (Trace DW‐REPSI) for quantifying the trace ADC in phantom and in vivo using a 3T clinical scanner. Theory and Methods: Trace DW‐REPSI datasets were acquired in 10 phantom and 10 healthy volunteers, with a maximum b‐value of 1601 s/mm2 and diffusion time of 10.75 ms. The self‐navigation properties of radial acquisitions were used for corrections of shot‐to‐shot phase and frequency shift fluctuations of the raw data. In vivo trace ADCs of total NAA (tNAA), total creatine (tCr), and total choline (tCho) extrapolated to pure gray and white matter fractions were compared, as well as trace ADCs estimated in voxels within white or gray matter‐dominant regions. Results: Trace ADCs in phantom show excellent agreement with reported values, and in vivo ADCs agree well with the expected differences between gray and white matter. For tNAA, tCr, and tCho, the trace ADCs extrapolated to pure gray and white matter ranged from 0.18–0.27 and 0.26–0.38 μm2/ms, respectively. In sets of gray and white matter‐dominant voxels, the values ranged from 0.21 to 0.27 and 0.24 to 0.31 μm2/ms, respectively. The overestimated trace ADCs from this sequence can be attributed to the short diffusion time. Conclusion: This study presents the first demonstration of the single‐shot diffusion trace‐weighted spectroscopic imaging sequence using radial echo planar trajectories. The Trace DW‐REPSI sequence could provide an estimate of the trace ADC in a much shorter scan time compared to conventional approaches that require three separate measurements. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the feasibility of downfield MR spectroscopic imaging (DF‐MRSI) in the human brain at 7T. Methods: A 7T DF‐MRSI pulse sequence was implemented based on the previously described methodology at 3T, with 3D phase‐encoding, 13‾31‾$$ 1\overline{3}3\overline{1} $$ spectral‐spatial excitation, and frequency selective refocusing. Data were pre‐processed followed by analysis using the "LCModel" software package, and metabolite maps created from the LCModel results. Total scan time, including brain MRI and a water‐reference MRSI, was 24 min. The sequence was tested in 10 normal volunteers. Estimated metabolite levels and uncertainty values (Cramer Rao lower bounds, CRLBs) for nine downfield peaks were compared between seven different brain regions, anterior cingulate cortex (ACC), centrum semiovale (CSO), corpus callosum (CC), cerebellar vermis (CV), dorsolateral prefrontal cortex (DLPFC), posterior cingulate cortex (PCC), and thalamus (Thal). Results: DF peaks were relatively uniformly distributed throughout the brain, with only a small number of peaks showing any significant regional variations. Most DF peaks had average CRLB<25% in most brain regions. Average SNR values were higher for the brain regions ACC and DLPFC (˜7 ± 0.95, mean ± SD) while in a range of 3.4–6.0 for other brain regions. Average linewidth (FWHM) values were greater than 35 Hz in the ACC, CV, and Thal, and 22 Hz in CC, CSO, DLPFC, and PCC. Conclusion: High‐field DF‐MRSI is able to spatially map exchangeable protons in the human brain at high resolution and with near whole‐brain coverage in acceptable scan times, and in the future may be used to study metabolism of brain tumors or other neuropathological disorders. [ABSTRACT FROM AUTHOR]

Societal Impact Statement Summary Pulse crops, including dry pea, lentil, and chickpea, are rich sources of protein, low digestible carbohydrates, and micronutrients. With the increasing demand for plant‐based protein with gluten‐free and allergen‐free foods, pulse crops have become of global importance for meeting the nutritional demand of growing populations. Breeding for nutritional quality is becoming a bottleneck for most breeding programs globally due to the cost of these available tools. Therefore, low‐cost, high‐throughput phenotyping tools will be a focus of interest for the selection of elite germplasm for cultivar development and gene identification for pulse cultivar development. This publication explains the emerging and future trends of phenotyping tools that are feasible for pulse breeding and improving nutritional quality.Precision agriculture tools based on spectroscopic and imaging techniques now contribute to high‐throughput phenotyping (HTP) pipelines for nutritional and agronomic traits to speed breeding and selection for cultivar development. Fourier transform mid‐infrared (FT‐MIR) spectroscopy has been a reliable HTP tool for macro nutritional traits in pulse crops. Hyperspectral, multispectral, and RGB (red‐green‐blue) imaging with unmanned aerial systems (UAVs) have been developed to measure agronomic traits for cereals, but these techniques have yet to be developed and validated for pulse crops. This review summarizes different phenotyping techniques applied to nutritional and agronomic traits for crop breeding and reviews applications of machine learning tools for optimizing HTP. [ABSTRACT FROM AUTHOR]

HXI on ASO-S and STIX onboard Solar Orbiter are the first simultaneously operating solar hard X-ray imaging spectrometers. ASO-S's low Earth orbit and Solar Orbiter's periodic displacement from the Sun–Earth line enables multi-viewpoint solar hard X-ray spectroscopic imaging analysis for the first time. Here, we demonstrate the potential of this new capability by reporting the first results of 3D triangulation of hard X-ray sources in the SOL2023-12-31T21:55 X5 flare. HXI and STIX observed the flare near the east limb with an observer separation angle of 18°. We triangulated the brightest regions within each source, which enabled us to characterise the large-scale hard X-ray geometry of the flare. The footpoints were found to be in the chromosphere within uncertainty, as expected, while the thermal looptop source was centred at an altitude of 15.1 ± 1 Mm. Given the footpoint separation, this implies a more elongated magnetic-loop structure than predicted by a semi-circular model. These results show the strong diagnostic power of joint HXI and STIX observations for understanding the 3D geometry of solar flares. We conclude by discussing the next steps required to fully exploit their potential. [ABSTRACT FROM AUTHOR]

Spaceborne spectroscopic imaging offers the potential to improve our understanding of biodiversity and ecosystem services, particularly for challenging and rich environments like mangroves. Understanding the signals present in large volumes of high-dimensional spectroscopic observations of vegetation communities requires the characterization of seasonal phenology and response to environmental conditions. This analysis leverages both spectroscopic and phenological information to characterize vegetation communities in the Sundarban riverine mangrove forest of the Ganges–Brahmaputra delta. Parallel analyses of surface reflectance spectra from NASA's EMIT imaging spectrometer and MODIS vegetation abundance time series (2000–2022) reveal the spectroscopic and phenological diversity of the Sundarban mangrove communities. A comparison of spectral and temporal feature spaces rendered with low-order principal components and 3D embeddings from Uniform Manifold Approximation and Projection (UMAP) reveals similar structures with multiple spectral and temporal endmembers and multiple internal amplitude continua for both EMIT reflectance and MODIS Enhanced Vegetation Index (EVI) phenology. The spectral and temporal feature spaces of the Sundarban represent independent observations sharing a common structure that is driven by the physical processes controlling tree canopy spectral properties and their temporal evolution. Spectral and phenological endmembers reside at the peripheries of the mangrove forest with multiple outward gradients in amplitude of reflectance and phenology within the forest. Longitudinal gradients of both phenology and reflectance amplitude coincide with LiDAR-derived gradients in tree canopy height and sub-canopy ground elevation, suggesting the influence of surface hydrology and sediment deposition. RGB composite maps of both linear (PC) and nonlinear (UMAP) 3D feature spaces reveal a strong contrast between the phenological and spectroscopic diversity of the eastern Sundarban and the less diverse western Sundarban. [ABSTRACT FROM AUTHOR]

The liver plays a central role in metabolic homeostasis, as exemplified by a variety of clinical disorders with hepatic and systemic metabolic disarrays. Of particular interest are the complex interactions between lipid and carbohydrate metabolism in highly prevalent conditions such as obesity, diabetes, and fatty liver disease. Limited accessibility and the need for invasive procedures challenge direct investigations in humans. Hence, noninvasive dynamic evaluations of glycolytic flux and steady‐state assessments of lipid levels and composition are crucial for basic understanding and may open new avenues toward novel therapeutic targets. Here, three different MR spectroscopy (MRS) techniques that have been combined in a single interleaved examination in a 7T MR scanner are evaluated. 1H‐MRS and 13C‐MRS probe endogenous metabolites, while deuterium metabolic imaging (DMI) relies on administration of deuterated tracers, currently 2H‐labelled glucose, to map the spatial and temporal evolution of their metabolic fate. All three techniques have been optimized for a robust single‐session clinical investigation and applied in a preliminary study of healthy subjects. The use of a triple‐channel 1H/2H/13C RF coil enables interleaved examinations with no need for repositioning. Short‐echo‐time STEAM spectroscopy provides well resolved spectra to quantify lipid content and composition. The relative benefits of using water saturation versus metabolite cycling and types of respiratory synchronization were evaluated. 2H‐MR spectroscopic imaging allowed for registration of time‐ and space‐resolved glucose levels following oral ingestion of 2H‐glucose, while natural abundance 13C‐MRS of glycogen provides a dynamic measure of hepatic glucose storage. For DMI and 13C‐MRS, the measurement precision of the method was estimated to be about 0.2 and about 16 mM, respectively, for 5 min scanning periods. Excellent results were shown for the determination of dynamic uptake of glucose with DMI and lipid profiles with 1H‐MRS, while the determination of changes in glycogen levels by 13C‐MRS is also feasible but somewhat more limited by signal‐to‐noise ratio. [ABSTRACT FROM AUTHOR]

Abstract Single-molecule localization microscopy (SMLM) surpasses the diffraction limit by randomly switching fluorophores between fluorescent and dark states, precisely pinpointing the resulted isolated emission patterns, thereby reconstructing the super-resolution images based on the accumulated locations of thousands to millions of single molecules. This technique achieves a ten-fold improvement in resolution, unveiling the intricate details of molecular activities and structures in cells and tissues. Multicolor SMLM extends this capability by imaging distinct protein species labeled with various fluorescent probes, providing insights into structural intricacies and spatial relationships among different targets. This review explores recent advancements in multicolor SMLM, evaluates the strengths and limitations of each variant, and discusses the future prospects.

Purpose: Serine is a major source of one‐carbon units needed for the synthesis of nucleotides and the production of intramitochondrial nicotinamide adenine dinucleotide phosphate (NADPH), and it plays an important role in cancer cell proliferation. The aim of this study was to develop a deuterium (2H) MRS imaging method for imaging tumor serine metabolism. Methods: Sequential (2H) spectra and spectroscopic images were used to monitor the metabolism of [2,3,3‐2H3]serine in patient‐derived glioblastoma cells in vitro and in tumors obtained by their orthotopic implantation in mouse brain. Results: [14,14‐2H2] 5,10‐methylene‐tetrahydrofolate, [2H]glycine, [2H]formate, and labeled water were detected in cell suspensions and water labeling in spectroscopic images of tumors. Studies in cells and tumors with variable mitochondrial content and inhibitor studies in cells demonstrated that most of the labeled serine was metabolized in the mitochondria. Water labeling in the cell suspensions was correlated with formate labeling; therefore, water labeling observed in tumors could be used to provide a surrogate measure of flux in the pathway of one‐carbon metabolism in vivo. Conclusion: The method has the potential to be used clinically to select patients for treatment with inhibitors of one‐carbon metabolism and subsequently to detect their early responses to such treatment. [ABSTRACT FROM AUTHOR]

Fluorescent flippers have been introduced as small‐molecule probes to image membrane tension in living systems. This study describes the design, synthesis, spectroscopic and imaging properties of flippers that are elongated by one and two alkynes inserted between the push and the pull dithienothiophene domains. The resulting mechanophores combine characteristics of flippers, reporting on physical compression in the ground state, and molecular rotors, reporting on torsional motion in the excited state, to take their photophysics to new level of sophistication. Intensity ratios in broadened excitation bands from differently twisted conformers of core‐alkynylated flippers thus report on mechanical compression. Lifetime boosts from ultrafast excited‐state planarization and lifetime drops from competitive intersystem crossing into triplet states report on viscosity. In standard lipid bilayer membranes, core‐alkynylated flippers are too long for one leaflet and tilt or extend into disordered interleaflet space, which preserves rotor‐like torsional disorder and thus weak, blue‐shifted fluorescence. Flipper‐like planarization occurs only in highly ordered membranes of matching leaflet thickness, where they light up and selectively report on these thick membranes with red‐shifted, sharpened excitation maxima, high intensity and long lifetime. [ABSTRACT FROM AUTHOR]

We present statistics of z ∼ 6–9 galaxy outflows indicated by spatially extended gas emission and broad lines. With a total of 61 spectroscopically confirmed galaxies at z ∼ 6–9 in the JWST CEERS, GLASS, and ERO data, we find four galaxies with [O iii ] + H β ionized gas emission significantly extended beyond the kiloparsec-scale stellar components on the basis of the emission line images constructed by the subtraction of NIRCam broadband (line on/off-band) images. By comparison with low- z galaxies, the fraction of galaxies with spatially extended gas, 4/18, at z ∼ 6–9 is an order of magnitude higher than that at z ∼ 0–1, which can be explained by events triggered by frequent major mergers at high redshift. We also investigate medium- and high-resolution NIRSpec spectra of 30 galaxies at z ∼ 6–9, and identify five galaxies with broad (140−800 km s−1) lines in the [O iii ] forbidden line emission, suggestive of galaxy outflows. One galaxy at z = 6.38 shows both spatially extended gas emission and the broad lines, while none of the galaxies with spatially extended gas emission or broad lines present a clear signature of active galactic nuclei (AGN) in either the line diagnostics or type 1 AGN line broadening (>1000 km s−1), which suggests that outflows are mainly driven by stellar feedback. The existence of galaxies with/without spatially extended gas emission or broad lines may be explained by different viewing angles toward outflows or the fact that these are galaxies in the early, late, or post phases of galaxy outflows at high redshift, where relatively large fractions of such galaxies indicate longer-duration and/or more frequent outflows at early cosmic epochs. [ABSTRACT FROM AUTHOR]

Context. Mid-infrared emission features are important probes of the properties of ionized gas and hot or warm molecular gas, which are difficult to probe at other wavelengths. The Orion Bar photodissociation region (PDR) is a bright, nearby, and frequently studied target containing large amounts of gas under these conditions. Under the "PDRs4All" Early Release Science Program for JWST, a part of the Orion Bar was observed with MIRI integral field unit (IFU) spectroscopy, and these high-sensitivity IR spectroscopic images of very high angular resolution (0.2″) provide a rich observational inventory of the mid-infrared (MIR) emission lines, while resolving the H II region, the ionization front, and multiple dissociation fronts. Aims. We list, identify, and measure the most prominent gas emission lines in the Orion Bar using the new MIRI IFU data. An initial analysis summarizes the physical conditions of the gas and demonstrates the potential of these new data and future IFU observations with JWST. Methods. The MIRI IFU mosaic spatially resolves the substructure of the PDR, its footprint cutting perpendicularly across the ionization front and three dissociation fronts. We performed an up-to-date data reduction, and extracted five spectra that represent the ionized, atomic, and molecular gas layers. We identified the observed lines through a comparison with theoretical line lists derived from atomic data and simulated PDR models. The identified species and transitions are summarized in the main table of this work, with measurements of the line intensities and central wavelengths. Results. We identified around 100 lines and report an additional 18 lines that remain unidentified. The majority consists of H I recombination lines arising from the ionized gas layer bordering the PDR. The H I line ratios are well matched by emissivity coefficients from H recombination theory, but deviate by up to 10% because of contamination by He I lines. We report the observed emission lines of various ionization stages of Ne, P, S, Cl, Ar, Fe, and Ni. We show how the Ne III/Ne II, S IV/S III, and Ar III/Ar II ratios trace the conditions in the ionized layer bordering the PDR, while Fe III/Fe II and Ni III/Ni II exhibit a different behavior, as there are significant contributions to Fe II and Ni II from the neutral PDR gas. We observe the pure-rotational H2 lines in the vibrational ground state from 0–0 S(1) to 0–0 S (8), and in the first vibrationally excited state from 1–1 S (5) to 1–1 S(9). We derive H2 excitation diagrams, and for the three observed dissociation fronts, the rotational excitation can be approximated with one thermal (~700 K) component representative of an average gas temperature, and one nonthermal component (~2700 K) probing the effect of UV pumping. We compare these results to an existing model of the Orion Bar PDR, and find that the predicted excitation matches the data qualitatively, while adjustments to the parameters of the PDR model are required to reproduce the intensity of the 0–0 S (6) to S (8) lines. [ABSTRACT FROM AUTHOR]

Background/Objectives: The aim of this study was to evaluate brain metabolism using MR spectroscopy (MRS) after recovery from Coronavirus disease (COVID-19) and to test the impact of disease severity on brain metabolites. Methods: We performed MRS on 81 individuals (45 males, 36 females, aged 40–60), who had normal MRI findings and had recovered from COVID-19, classifying them into mild (17), moderate (36), and severe (28) groups based on disease severity during the acute phase. The study employed two-dimensional spectroscopic imaging above the corpus callosum, focusing on choline (Cho), creatine (Cr), and N-acetylaspartate (NAA). We analyzed Cho/Cr and NAA/Cr ratios as well as absolute concentrations using water as an internal reference. Results: Results indicated that the Cho/Cr ratio was higher with increasing disease severity, while absolute Cho and NAA/Cr ratios showed no significant differences across the groups. Notably, absolute Cr and NAA levels were significantly lower in patients with severe disease. Conclusions: These findings suggest that the severity of COVID-19 during the acute phase is associated with significant changes in brain metabolism, marked by an increase in Cho/Cr ratios and a reduction in Cr and NAA levels, reflecting substantial metabolic alterations post-recovery. [ABSTRACT FROM AUTHOR]

The MAPK signaling pathway with BRAF mutations has been shown to drive the pathogenesis of 40–60% of melanomas. Inhibitors of this pathway's BRAF and MEK components are currently used to treat these malignancies. However, responses to these treatments are not always successful. Therefore, identifying noninvasive biomarkers to predict treatment responses is essential for personalized medicine in melanoma. Using noninvasive 1H magnetic resonance spectroscopy (1H MRS), we previously showed that BRAF inhibition reduces lactate and alanine tumor levels in the early stages of effective therapy and could be considered as metabolic imaging biomarkers for drug response. The present work demonstrates that these metabolic changes observed by 1H MRS and those assessed by 31P MRS are also found in preclinical human melanoma models treated with MEK inhibitors. Apart from 1H and 31P MRS, additional supporting in vitro biochemical analyses are described. Our results indicate significant early metabolic correlations with response levels to MEK inhibition in the melanoma models and are consistent with our previous study of BRAF inhibition. Given these results, our study supports the potential clinical utility of noninvasive MRS to objectively image metabolic biomarkers for the early prediction of melanoma's response to MEK inhibition. [ABSTRACT FROM AUTHOR]

Lithium‐ion batteries (LIBs) are increasingly encouraged to enhance their environmental friendliness and safety while maintaining optimal energy density and cost‐effectiveness. Although various electrolytes using greener and safer glyme solvents have been reported, the low charge voltage (usually lower than 4.0 V vs Li/Li+) restricts the energy density of LIBs. Herein, tetraglyme, a less‐toxic, non‐volatile, and non‐flammable ether solvent, is exploited to build safer and greener LIBs. It is demonstrated that ether electrolytes, at a standard salt concentration (1 m), can be reversibly cycled to 4.5 V vs Li/Li+. Anchored with Boron‐rich cathode‐electrolyte interphase (CEI) and mitigated current collector corrosion, the LiNi0.8Mn0.1Co0.1O2 (NMC811) cathode delivers competitive cyclability versus commercial carbonate electrolytes when charged to 4.5 V. Synchrotron spectroscopic and imaging analyses show that the tetraglyme electrolyte can sufficiently suppress the overcharge behavior associated with the high‐voltage electrolyte decomposition, which is advantageous over previously reported glyme electrolytes. The new electrolyte also enables minimal transition metal dissolution and deposition. NMC811||hard carbon full cell delivers excellent cycling stability at C/3 with a high average Coulombic efficiency of 99.77%. This work reports an oxidation‐resilient tetraglyme electrolyte with record‐high 4.5 V stability and enlightens further applications of glyme solvents for sustainable LIBs by designing Boron‐rich interphases. [ABSTRACT FROM AUTHOR]

This study explores a sustainable approach for synthesizing silver nanocomposites (AgNCs) with enhanced antimicrobial and bioactivity using safe Lactobacillus strains and a whey-based medium (WBM). WBM effectively supported the growth of Lactobacillus delbrueckii and Lactobacillus acidophilus, triggering a stress response that led to AgNCs formation. The synthesized AgNCs were characterized using advanced spectroscopic and imaging techniques such as UV‒visible, Fourier transform infrared (FT-IR) spectroscopy, transmission electron (TEM), and scanning electron microscopy with energy dispersive X-ray analysis (SEM–Edx). Lb acidophilus-synthesized AgNCs in WBM (had DLS size average 817.2–974.3 ± PDI = 0.441 nm with an average of metal core size 13.32 ± 3.55 nm) exhibited significant antimicrobial activity against a broad spectrum of pathogens, including bacteria such as Escherichia coli (16.47 ± 2.19 nm), Bacillus cereus (15.31 ± 0.43 nm), Clostridium perfringens (25.95 ± 0.03 mm), Enterococcus faecalis (32.34 ± 0.07 mm), Listeria monocytogenes (23.33 ± 0.05 mm), methicillin-resistant Staphylococcus aureus (MRSA) (13.20 ± 1.76 mm), and filamentous fungi such as Aspergillus brasiliensis (33.46 ± 0.01 mm). In addition, Lb acidophilus-synthesized AgNCs in WBM exhibit remarkable free radical scavenging abilities, suggesting their potential as bioavailable antioxidants. These findings highlight the dual functionality of these biogenic AgNCs, making them promising candidates for applications in both medicine and nutrition. [ABSTRACT FROM AUTHOR]

A novel Fe3O4@coPPy-PTH nanocomposite-based sorbent was prepared via in situ oxidative polymerization using Fe3O4 nanoparticles with spherical and flower-like morphologies of thiophene and pyrrole as the feedstocks. The synthesized nanocomposite displayed sensitive extraction and determination of metal ions Co(II), Cr(III), and Ni(II) without a chelating agent, followed by microsample injection system-flame atomic absorption spectrometry. Advanced spectroscopic and imaging techniques including scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy were used to characterize the composition and morphology of the Fe3O4@coPPy-PTH nanocomposite. SEM observations showed that the size of the Fe3O4 nanoparticles changed from 30 nm to 120 nm in diameter after copolymer (PPy-PTH) coating. The Fe3O4@coPPy-PTH nanocomposite has good dispersion properties and stability in strong acid solutions. For effective extraction of the studied analytes, the influence of sample pH, volume of sample solution and eluent, amount of adsorbent, and interference of coexisting metal ions were optimized. Under the optimum conditions, preconcentration factors were obtained as 25 for all analytes. The calibration curves were linear in the range of 0.0-10.0 µg L-1 with coefficients of determination (R²) greater than 0.9957 for all three analytes. Limits of detection (S/N = 3) were calculated in the range of 0.17-0.23 µg L-1. Precision values, expressed as relative standard deviations, were lower than 3.0%, and relative recoveries were obtained in the range of 88.6%-103.6%. The proposed method (Fe3O4@coPPy-PTH/MSPE/MIS-FAAS) was successfully applied to extract and determine the studied metal ions in beer, wine, and nonalcoholic beverage samples. [ABSTRACT FROM AUTHOR]

Subthreshold depression is an essential precursor and risk factor for major depressive disorder, and its accurate identification and timely intervention are important for reducing the prevalence of major depressive disorder. Therefore, we used functional near-infrared spectroscopic imaging (fNIRS) to explore the characteristics of the brain neural activity of college students with subthreshold depression in the verbal fluency task. A total of 72 subthreshold depressed college students (SDs) and 67 healthy college students (HCs) were recruited, and all subjects were subjected to a verbal fluency task (VFT) while a 53-channel fNIRS device was used to collect the subjects' cerebral blood oxygenation signals. The results of the independent samples t -test showed that the mean oxyhemoglobin in the right dorsolateral prefrontal (ch34, ch42, ch45) and Broca's area (ch51, ch53) of SDs was lower than that of HCs. The peak oxygenated hemoglobin of SDs was lower in the right dorsolateral prefrontal (ch34) and Broca's area (ch51, ch53).The brain functional connectivity strength was lower than that of HCs. Correlation analysis showed that the left DLPFC and Broca's area were significantly negatively correlated with the depression level. SDs showed abnormally low, inadequate levels of brain activation and weak frontotemporal brain functional connectivity. The right DLPFC has a higher sensitivity for the differentiation of depressive symptoms and is suitable as a biomarker for the presence of depressive symptoms. Dysfunction in Broca's area can be used both as a marker of depressive symptoms and as a biomarker, indicating the severity of depressive symptoms. • Hypoperfusion in right DLPFC and Broca's area is physiological mechanisms distinguishing subthreshold depression. • Higher depression is associated with lower levels of cortical activation in the left DLPFC and Broca's area. • Subthreshold depression can be associated with low strength of overall brain functional connectivity. • fNIRS may be a potential tool to improve diagnostic accuracy for subthreshold depression. [ABSTRACT FROM AUTHOR]

Anxiety is a common psychological disorder associated with other mental disorders, with depression being the most common comorbidity. Few studies have examined the neural mechanisms underlying anxiety after controlling for depression. This study aimed to explore whether there are differences in cortical activation in anxiety patients with different severities whose depression are normal. In the current study, depression levels were normal for 366 subjects—139 healthy subjects, 117 with mild anxiety, and 110 with major anxiety. Using the Hospital Anxiety and Depression Scale (HADS) and a verbal fluency task (VFT) to test subjects' anxiety and depression and cognitive function, respectively. A 53‐channel guided near‐infrared spectroscopic imaging technology (fNIRS) detected the concentration of oxyhemoglobin (oxy‐Hb). Correlation analysis between anxiety severity and oxy‐Hb concentration in the brain cortex was performed, as well as ANOVA analysis of oxy‐Hb concentration among the three anxiety severity groups. The results showed that anxiety severity was significantly and negatively correlated with oxy‐Hb concentrations in the left frontal eye field (lFEF) and in the right dorsolateral prefrontal area (rDLPFC). The oxy‐Hb concentration in the lFEF and the rDLPFC were significantly lower in the major anxiety disorder group than that in the control group. This suggests that decreased cortical activity of the lFEF and rDLPFC may be neural markers of anxiety symptoms after controlling for depression. Anxiety symptoms without depression may be result from the dysfunction of the cognitive control network (CCN) which includes the lFEF and rDLPFC. Anxiety disorders often experience an internal sense of loss of control and often be associated with depression. This study aimed to explore the neural mechanisms underlying anxiety after controlling for depress ive symptoms. We found that decreased cortical activity of the lFEF and rDLPFC may be neural markers of anxiety symptoms after control depressive symptoms. Anxiety symptoms without depressive symptoms may be result from the dysfunction of cognitive control network including lFEF and rDLPFC. [ABSTRACT FROM AUTHOR]

Introduction: Nicotinamide adenine dinucleotide (NAD) is a crucial molecule in cellular metabolism and signaling. Mapping intracellular NAD content of human brain has long been of interest. However, the sub-millimolar level of cerebral NAD concentration poses significant challenges for in vivo measurement and imaging. Methods: In this study, we demonstrated the feasibility of non-invasively mapping NAD contents in entire human brain by employing a phosphorus-31 magnetic resonance spectroscopic imaging (31P-MRSI)-based NAD assay at ultrahigh field (7 Tesla), in combination with a probabilistic subspace-based processing method. Results: The processing method achieved about a 10-fold reduction in noise over raw measurements, resulting in remarkably reduced estimation errors of NAD. Quantified NAD levels, observed at approximately 0.4 mM, exhibited good reproducibility within repeated scans on the same subject and good consistency across subjects in group data (2.3 cc nominal resolution). One set of higher-resolution data (1.0 cc nominal resolution) unveiled potential for assessing tissue metabolic heterogeneity, showing similar NAD distributions in white and gray matter. Preliminary analysis of age dependence suggested that the NAD level decreases with age. Discussion: These results illustrate favorable outcomes of our first attempt to use ultrahigh field 31P-MRSI and advanced processing techniques to generate a whole-brain map of low-concentration intracellular NAD content in the human brain. [ABSTRACT FROM AUTHOR]

In this study, the 4,9 diazafluoren-9-one ligand and [Y(Daf)2Cl3.OH2] complex were synthesized. The interaction of this complex with DNA and bovine serum albumin (BSA) was investigated by UV-vis and fluorescence spectroscopy. The molecular docking method was used to confirm the experimental results, investigate the type of interaction, and determine the binding site. The binding constant and Stern -- Volmer constant were calculated using spectroscopy techniques. The binding constant of the Y-complex with DNA and BSA obtained using the UV-vis technique was 1.61 × 105 M-1 and 0.49 × 105 M-1, while that obtained using the fluorescence method was 3.39 × 105 M-1 and 3.63 × 105 M-1, respectively. The results of experimental and theoretical data showed that the interaction between the yttrium complex and DNA and BSA is driven by the hydrogen bond and van der Waals interaction, respectively. The yttrium complex communicates with DNA via the groove interaction. This complex has high binding energy with bovine serum albumin. In addition, the molecular docking results showed that the complex binds to the IIA subdomain of BSA (site I). Finally, anticancer activity of the yttrium complex was studied on MCF-7 and A549 cell lines by using the MTT method. The IC50 values obtained showed that the yttrium complex possesses anticancer activity. [ABSTRACT FROM AUTHOR]

Maize (Zea mays) is one of the most cultivated plants in the world. Due to the large area, the scale of its production, and the demand to increase the yield, there is a need for new environmentally friendly fertilizers. One group of such candidates is bacteria-produced nodulation (or nod) factors. Limited research has explored the impact of nodulation, factors on maize within field conditions, with most studies restricted to greenhouse settings and early developmental stages. Additionally, there is a scarcity of investigations that elucidate the metabolic alterations in the maize stem due to nod-factor exposure. It was therefore the aim of this study. Maize stem's metabolites and fibers were analyzed with various imaging analytical techniques: matrix assisted laser desorption ionization–mass spectrometry imaging (MALDI-MSI), Raman spectroscopy, attenuated total reflection Fourier transform infrared spectroscopy (ATR FT-IR), and diffuse reflectance infrared Fourier transform spectroscopy. Moreover, the biochemical analyses were used to evaluate the proteins and soluble carbohydrates concentration and total phenolic content. These techniques were used to evaluate the influence of nod factor-based biofertilizer on the growth of a non-symbiotic plant, maize. The biofertilizer increased the grain yield and the stem mass. Moreover, the spectroscopic and biochemical investigation proved the appreciable biochemical changes in the stems of the maize in biofertilizer-treated plants. Noticeable changes were found in the spatial distribution and the increase in the concentration of flavonoids such as maysin, quercetin, and rutin. Moreover, the concentration of cell wall components (fibers) increased. Furthermore, it was shown that the use of untargeted analyses (such as Raman and ATR FT-IR, spectroscopic imaging, and MALDI-MSI) is useful for the investigation of the biochemical changes in plants. [ABSTRACT FROM AUTHOR]

Scanning electron microscopy (SEM) coupled with energy‐dispersive X‐ray spectroscopy (EDX) enables the determination of the composition and structure of tiny calcified remains occasionally recovered during burial excavations. To deepen the practical application of this technique, we performed SEM/EDX analysis on three different tiny mineralized, roughly rounded structures with a diameter of less than 5 mm recovered from a pre‐Hispanic collective funerary cave from El Hierro (Canary Islands) and a mineral spherulite of similar size and outer aspect. After SEM imaging and spectroscopic analysis, we conclude that the three samples represent a sesamoid bone, a kidney stone, and a possible case of sialolithiasis. In contrast, the spherulite is a mineral formation composed of calcium carbonate. Our data confirm SEM analysis's usefulness in identifying small, mineralized remains recovered during burial excavations and its contribution to studying past populations. However, we are aware that taphonomic changes may alter, at least partially, the structure, and/or elemental composition of archaeological samples, obscuring differential diagnosis. [ABSTRACT FROM AUTHOR]

Solar surges are collimated flows of plasma that occur in the periphery of active regions (ARs). The kinematics, physical properties, and triggering mechanisms of a solar surge were studied through imaging and spectroscopic diagnosis. The surge has a typical inverted Y-shape, and it moves with a speed of more than 200 km/s in the transition-region (TR) which is much higher than the sound speed of TR. The observational findings suggest that the surge was triggered due to magnetic reconnection. In addition, a hot jet formed after around 03 minutes and propagated at a speed that is comparable to the sound speed of the corona. Hence, most probably, the hot jet forms due to the chromospheric evaporation. The spectroscopic diagnosis reveals that electron densities are log10 10.82±0.90 and log10 9.93±1.27 in the base and spire of the surge, respectively. Further, it is found that the Si iv line ratio is around 1.85 in the base and 1.80 in the spire of the surge. Hence, we say that most of the Si iv profiles are forming under optically thick conditions in the surge. Most importantly, some Si iv spectral profiles from the base and spire of the surge are double peak profiles with a dip close to the central wavelength. Also, in the same region, optically thick conditions exist, therefore, most probably, the central dip in the profiles is a result of the self-absorption. This is the first-ever report of self-absorption in the solar surges. [ABSTRACT FROM AUTHOR]

Purpose: We present a novel silent echo-planar spectroscopic imaging (EPSI) readout, which uses an ultrasonic gradient insert to accelerate MRSI while producing a high spectral bandwidth (20 kHz) and a low sound level. Methods: The ultrasonic gradient insert consisted of a single-axis (z-direction) plug-and-play gradient coil, powered by an audio amplifier, and produced 40mT/m at 20 kHz. The silent EPSI readout was implemented in a phase-encodedMRSI acquisition. Here, the additional spatial encoding provided by this silent EPSI readout was used to reduce the number of phase-encoding steps. Spectroscopic acquisitions using phase-encoded MRSI, a conventional EPSI-readout, and the silent EPSI readout were performed on a phantom containing metabolites with resonance frequencies in the ppm range of brain metabolites (0-4 ppm). These acquisitions were used to determine sound levels, showcase the high spectral bandwidth of the silent EPSI readout, and determine the SNR efficiency and the scan efficiency. Results: The silent EPSI readout featured a 19-dB lower sound level than a conventional EPSI readout while featuring a high spectral bandwidth of 20 kHz without spectral ghosting artifacts. Compared with phase-encoded MRSI, the silent EPSI readout provided a 4.5-fold reduction in scan time. In addition, the scan efficiency of the silent EPSI readout was higher (82.5% vs. 51.5%) than the conventional EPSI readout. Conclusions: We have for the first time demonstrated a silent spectroscopic imaging readout with a high spectral bandwidth and low sound level. This sound reduction provided by the silent readout is expected to have applications in sound-sensitive patient groups, whereas the high spectral bandwidth could benefit ultrahigh-field MR systems. [ABSTRACT FROM AUTHOR]

Although embryo transfers have grown considerably in the cattle industry, the selection of embryos required for successful pregnancies remains a challenging task. Visual inspection of 7th-day embryos using a stereomicroscope, followed by classification based on morphological features is the most commonly practiced procedure. However, there are inaccuracies and inconsistencies in the manual grading of bovine embryos. The objective of this review was to evaluate the potential of imaging and spectroscopic techniques in the selection of bovine embryos. Digital analysis of microscopic images through extracting visual features in the embryo region, and classification using machine learning methods have yielded about 88-96% success in pregnancies. The Raman spectral pattern provides valuable information regarding developmental stages and quality of the embryo. The Raman spectroscopy approach has also been successfully used to determine various parameters of bovine oocytes. Besides, Fourier Transform Infrared (FTIR) spectroscopy has the ability to assess embryo quality through analyzing embryo composition, including nucleic acid and amides present. Hyperspectral Imaging has also been used to characterize metabolite production during embryo growth. Although the time-lapse imaging approach is beneficial for morphokinetics evaluation of embryo development, optimized protocols are required for successful implementation in bovine embryo transfers. Most imaging and spectroscopic findings are still only at an experimental stage. Further research is warranted to improve the repeatability and practicality to implement in commercial facilities. [ABSTRACT FROM AUTHOR]

We present the results of a search for extended emission-line regions (EELRs) ionized by extant or recently faded active galactic nuclei (AGNs), using [O III] narrow-band imaging and spectroscopic follow-up. The sample includes 198 galaxies in 92 strongly interacting or merging galaxy systems in the range of z  = 0.009–0.0285. Among these, three systems have EELRs extended beyond 10 kpc in projection from the nucleus detected in previous studies. We identify a single new distant emission region, projected 35 kpc from UGC 5941. Our optical spectrum does not detect He II, but its strong-line ratios put this in the same class as securely characterized EELR clouds. The nucleus of UGC 5941 is dominated by recent star formation, preventing detection of any weak ongoing AGN. Overall counts of distant EELRs in this and the previous TELPERION samples give incidence 2–5 per cent depending on galaxy and AGN selection, 20–50 times higher than the Galaxy Zoo EELR survey with its higher surface-brightness threshold and much larger input sample. AGNs in interacting and merging systems have an increased detection rate of 12 ± 6 per cent, while none are detected around non-interacting AGNs. Some of these AGNs are at luminosity low enough to require additional X-ray or far-infrared information to tell whether the EELR ionization level suggests long-term fading. [ABSTRACT FROM AUTHOR]

The conversion of electrochemical processes into mechanical deformation in organic mixed ionic‐electronic conductors (OMIECs) enables artificial muscle‐like actuators but is also critical for degradation processes affecting OMIEC‐based devices. To provide a microscopic understanding of electroactuation, the modulated electrochemical atomic force microscopy (mEC‐AFM) is introduced here as a novel in‐operando characterization method for electroactive materials. The technique enables multidimensional spectroscopic investigations of local electroactuation and charge uptake giving access to the electroactuation transfer function. For poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) based microelectrodes, the spectroscopic measurements are combined with multichannel mEC‐AFM imaging, providing maps of local electroactuation amplitude and phase as well as surface morphology. The results demonstrate that the amplitude and timescales of electroactuation are governed by the drift motion of hydrated ions. Accordingly, slower water diffusion processes are not limiting, and the results illustrate how OMIEC microactuators can operate at sub‐millisecond timescales. [ABSTRACT FROM AUTHOR]

Solar filament eruptions are often characterized by stepwise evolution due to the involvement of multiple mechanisms, such as magnetohydrodynamic instabilities and magnetic reconnection. In this article, we investigated a confined filament eruption with a distinct two-stage evolution by using the imaging and spectroscopic observations from the Interface Region Imaging Spectrograph and the Solar Dynamics Observatory. The eruption originated from a kinked filament thread that separated from an active region filament. In the first stage, the filament thread rose slowly and was obstructed due to flux pile-up in its front. This obstruction brought the filament thread into reconnection with a nearby loop-like structure, which enlarged the flux rope and changed its connectivity through the foot-point migration. The newly formed flux rope became more kink unstable and drove the rapid eruption in the second stage. It ascended into the upper atmosphere and initiated the reconnection with the overlying field. Finally, the flux rope was totally disintegrated, producing several solar jets along the overlying field. These observations demonstrate that the external reconnection between the flux rope and overlying field can destroy the flux rope, thus playing a crucial role in confining the solar eruptions. [ABSTRACT FROM AUTHOR]

The persimmon-red glazed wares, characterized by a reddish-brown appearance with high gloss, were one of the main varieties of glazes manufactured in Jian kilns (Fujian province, China) during the Song Dynasty. Densely packed dendritic ε-Fe 2 O 3 crystals in microns size composed of several branches were observed in the glazes surfaces of Jian persimmon-red wares. The branches, consisting of well-arranged rod-like crystals with offset around 110 or 220 nm, could serve as sub-micron mirrors to improve the glaze gloss. A number of Al and few Ti and Mn ions were detected to substitute Fe ions in ε-Fe 2 O 3 crystals. The Al substitution could play a dual role in ε-Fe 2 O 3 structure: (1) stabilizes the structure through increasing of cationic disorder and (2) makes the appearance less dark, which could account for the nice persimmon-red appearance of Jian wares. Besides, zircon, quartz, hematite, jacobsite and mullite were also observed in the glaze surfaces. • Dendritic ε-Fe 2 O 3 crystals in microns size composed of several branches were observed in the glazes surfaces of Jian persimmon-red wares. • The branches consisting of well-arranged rod-like crystals with offset ~110 or 220 nm could serve as sub-micron mirrors to improve glaze gloss. • Al substitutions in ε-Fe 2 O 3 crystals could play a dual role of acting as stabilizers to increase cationic disorder and making appearance less dark. • A few impurity crystals including zircon, quartz, hematite, jacobsite and mullite were detected in the glazes surfaces. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this work was to design and build a coil for quadri‐nuclear MRI of the human brain at 7 T. Methods: We built a transmit/receive triple‐tuned (45.6 MHz for 2$$ {}^2 $$H, 78.6 MHz for 23$$ {}^{23} $$Na, and 120.3 MHz for 31$$ {}^{31} $$P) quadrature four‐rod birdcage that was geometrically interleaved with a transmit/receive four‐channel dipole array (297.2 MHz for 1$$ {}^1 $$H). The birdcage rods contained passive, two‐pole resonant circuits that emulated capacitors required for single‐tuning at three frequencies. The birdcage assembly also included triple‐tuned matching networks, baluns, and transmit/receive switches. We assessed the performance of the coil with quality factor (Q) and signal‐to‐noise ratio (SNR) measurements, and performed in vivo multinuclear MRI and MR spectroscopic imaging (MRSI). Results: Q measurements showed that the triple‐tuned birdcage efficiency was within 33% of that of single‐tuned baseline birdcages at all three frequencies. The quadri‐tuned coil SNR was 78%, 59%, 44%, and 48% lower than that of single or dual‐tuned reference coils for 1$$ {}^1 $$H, 2$$ {}^2 $$H, 23$$ {}^{23} $$Na, and 31$$ {}^{31} $$P, respectively. Quadri‐nuclear MRI and MRSI was demonstrated in brain in vivo in about 30 min. Conclusion: While the SNR of the quadruple tuned coil was significantly lower than dual‐ and single‐tuned reference coils, it represents a step toward truly simultaneous quadri‐nuclear measurements. [ABSTRACT FROM AUTHOR]

Ordered hexagonal mesoporous aluminophosphate and its cobalt‐substituted analogue were successfully synthesized using ionic liquid as a structure‐directing agent. The resulting materials were systematically characterized by various analytical, spectroscopic, and imaging methods, confirming the presence of divalent cobalt in the tetrahedral framework of the matrix. Further, the high surface area, pore volume, and thicker mesopore walls of these materials impart good thermal and hydrothermal stability. The mesoporous catalysts showed excellent activity towards the oxidation of cyclohexane reactions using hydrogen peroxide as an oxidant, with 98.5 % conversion and 90.4 % selectivity towards cyclohexanol. [ABSTRACT FROM AUTHOR]

Diffractive optics devices are optical devices in which the amplitude or phase of the incident light is spatially modulated periodically by a micro-nanomaterial based structure. The study of diffractive optics devices in the field of micro and nano can change the spectroscopic behavior of micro and nano diffractive optics devices by varying the microstructure of the structure and the optical wave properties, which can effectively and reasonably modulate the optical wave signal. To study the effect of different parameter structures on the performance of micro-nano diffraction optical devices, in this paper, two three-dimensional array structures of diffractive optical devices are proposed, which are a vertex-intersecting regular tetrahedron structure and a base-intersecting regular frustum structure. Using the Finite-Difference Time-Domain method, the spectroscopic images of the diffractive optics of the constructed micro-nano diffractive devices are studied in the near-infrared band by varying the height of the constructed structures, the type of structures, the wavelength of the incident light waves, and the polarization direction of the light waves in different 3D height coordinates. The effects of different parameter changes on the performance of the micro-nano diffractive optics devices were analyzed by image comparison. The results show that the best diffraction effect is achieved at a structure height of 0.9 μm for both models with different structure types. The study of both structures at this structure height reveals that the location of diffraction occurrence and the intensity of diffraction can be tuned by varying the structure and the relevant parameters such as the polarization of the light wave. This paper has some theoretical applications for the study of high-performance diffractive optics. [ABSTRACT FROM AUTHOR]

Purpose: To demonstrate slowly varying, erroneous magnetic field gradients for oscillating readouts due to the mechanically resonant behavior of gradient systems. Methods: Projections of a static phantom were acquired using a one‐dimensional (1D) EPI sequence with varying EPI frequencies ranging from 1121 to 1580 Hz on clinical 3T systems (30 mT/m, 200 T/m/s). Phase due to static B0 inhomogeneities was eliminated by a complex division of two separate scans with different polarities of the EPI readout. The temporal evolution of phase was evaluated and related to the mechanical resonances of the gradient systems derived from the gradient modulation transfer function. Additionally, the impact of temporally varying mechanical resonance effects on EPI was evaluated using an echo‐planar spectroscopic imaging sequence. Results: A beat phenomenon resulting in a slowly varying phase was observed. Its temporal frequency was given by the difference between the EPI frequency and the mechanical resonance frequency of the activated gradient axis. The maximum erroneous, oscillating phase during phase encoding was ±0.5 rad for an EPI frequency of 1281 Hz. Echo‐planar spectroscopic imaging images showed the resulting time‐dependent stretching/compression of the FOV. Conclusion: Oscillating readouts such as those used in EPI can result in low‐frequency, erroneous phase contributions, which are explained by the beat phenomenon. Therefore, EPI phase‐correction approaches may need to include beat effects for accurate image reconstruction. [ABSTRACT FROM AUTHOR]

Purpose: Water removal is one of the computational bottlenecks in the processing of high‐resolution MRSI data. The purpose of this work is to propose an approach to reduce the computing time required for water removal in large MRS data. Methods: In this work, we describe a singular value decomposition–based approach that uses the partial position‐time separability and the time‐domain linear predictability of MRSI data to reduce the computational time required for water removal. Our approach arranges MRS signals in a Casorati matrix form, applies low‐rank approximations utilizing singular value decomposition, removes residual water from the most prominent left‐singular vectors, and finally reconstructs the water‐free matrix using the processed left‐singular vectors. Results: We have demonstrated the effectiveness of our proposed algorithm for water removal using both simulated and in vivo data. The proposed algorithm encompasses a pip‐installable tool (https://pypi.org/project/CSVD/), available on GitHub (https://github.com/amirshamaei/CSVD), empowering researchers to use it in future studies. Additionally, to further promote transparency and reproducibility, we provide comprehensive code for result replication. Conclusions: The findings of this study suggest that the proposed method is a promising alternative to existing water removal methods due to its low processing time and good performance in removing water signals. [ABSTRACT FROM AUTHOR]

Fluorine MRI is finding wider acceptance in theranostics applications where imaging of 19F hotspots of fluorinated contrast material is central. The essence of such applications is to capture ghosting‐artifact‐free images of the inherently low MR response under clinically viable conditions. To serve this purpose, this work introduces the balanced spiral spectroscopic imaging (BaSSI) sequence, which is implemented on a 3.0 T clinical scanner and is capable of generating 19F hotspot images in an efficient manner. The sequence utilizes an all‐phase‐encoded pseudo‐spiral k‐space trajectory, enabling the acquisition of broadband (80 ppm) fluorine spectra free from chemical shift ghosting. BaSSI can acquire a 64 × 64 image with 1 mm × 1 mm voxels in just 14 s, significantly outperforming typical MRSI sequences used in 1H or 31P imaging. The study employed in silico characterization to verify essential design choices such as the excitation pulse, as well as to identify the boundaries of the parameter space explored for optimization. BaSSI's performance was further benchmarked against the 3D ultrashort‐echo‐time balanced steady‐state free precession (3D UTE BSSFP) sequence, a well established method used in 19F MRI, in vitro. Both sequences underwent extensive optimization through exploration of a wide parameter space on a small phantom containing 10 μL of non‐diluted bulk perfluorooctylbromide (PFOB) prior to comparative experiments. Subsequent to optimization, BaSSI and 3D UTE BSSFP were employed to capture images of small non‐diluted bulk PFOB samples (0.10 and 0.05 μL), with variations in the number of signal averages, and thus the total scan time, in order to assess the detection sensitivities of the sequences. In these experiments, the detection sensitivity was evaluated using the Rose criterion (Rc), which provides a quantitative metric for assessing object visibility. The study further demonstrated BaSSI's utility as a (pre)clinical tool through postmortem imaging of polymer microspheres filled with PFOB in a BALB/c mouse. Anatomic localization of 19F hotspots was achieved by denoising raw data obtained with BaSSI using a filter based on the Rose criterion. These data were then successfully registered to 1H anatomical images. BaSSI demonstrated superior detection sensitivity in the benchmarking analysis, achieving Rc values approximately twice as high as those obtained with the 3D UTE BSSFP method. The technique successfully facilitated imaging and precise localization of 19F hotspots in postmortem experiments. However, it is important to highlight that imaging 10 mM PFOB in small mice postmortem, utilizing a 48 × 48 × 48 3D scan, demanded a substantial scan time of 1 h and 45 min. Further studies will explore accelerated imaging techniques, such as compressed sensing, to enhance BaSSI's clinical utility. [ABSTRACT FROM AUTHOR]

Background: Magnetic resonance (MR) imaging of deuterated glucose, termed deuterium metabolic imaging (DMI), is emerging as a biomarker of pathway-specific glucose metabolism in tumors. DMI is being studied as a useful marker of treatment response in a scan-rescan scenario. This study aims to evaluate the repeatability of brain DMI. Methods: A repeatability study was performed in healthy volunteers from December 2022 to March 2023. The participants consumed 75 g of [6,6′-2H2]glucose. The delivery of 2H-glucose to the brain and its conversion to 2H-glutamine + glutamate, 2H-lactate, and 2H-water DMI was imaged at baseline and at 30, 70, and 120 min. DMI was performed using MR spectroscopic imaging on a 3-T system equipped with a 1H/2H-tuned head coil. Coefficients of variation (CoV) were computed for estimation of repeatability and between-subject variability. In a set of exploratory analyses, the variability effects of region, processing, and normalization were estimated. Results: Six male participants were recruited, aged 34 ± 6.5 years (mean ± standard deviation). There was 42 ± 2.7 days between sessions. Whole-brain levels of glutamine + glutamate, lactate, and glucose increased to 3.22 ± 0.4 mM, 1.55 ± 0.3 mM, and 3 ± 0.7 mM, respectively. The best signal-to-noise ratio and repeatability was obtained at the 120-min timepoint. Here, the within-subject whole-brain CoVs were -10% for all metabolites, while the between-subject CoVs were -20%. Conclusions: DMI of glucose and its downstream metabolites is feasible and repeatable on a clinical 3 T system. Trial registration: ClinicalTrials.gov, NCT05402566, registered the 25th of May 2022. Relevance statement: Brain deuterium metabolic imaging of healthy volunteers is repeatable and feasible at clinical field strengths, enabling the study of shifts in tumor metabolism associated with treatment response. Key points: • Deuterium metabolic imaging is an emerging tumor biomarker with unknown repeatability. • The repeatability of deuterium metabolic imaging is on par with FDG-PET. • The study of deuterium metabolic imaging in clinical populations is feasible. [ABSTRACT FROM AUTHOR]

Oral potentially malignant disorders (OPMDs) are precursors to over 80% of oral cancers. Hematoxylin and eosin (H&E) staining, followed by pathologist interpretation of tissue and cellular morphology, is the current gold standard for diagnosis. However, this method is qualitative, can result in errors during the multi-step diagnostic process, and results may have significant inter-observer variability. Chemical imaging (CI) offers a promising alternative, wherein label-free imaging is used to record both the morphology and the composition of tissue and artificial intelligence (AI) is used to objectively assign histologic information. Here, we employ quantum cascade laser (QCL)-based discrete frequency infrared (DFIR) chemical imaging to record data from oral tissues. In this proof-of-concept study, we focused on achieving tissue segmentation into three classes (connective tissue, dysplastic epithelium, and normal epithelium) using a convolutional neural network (CNN) applied to three bands of label-free DFIR data with paired darkfield visible imaging. Using pathologist-annotated H&E images as the ground truth, we demonstrate results that are 94.5% accurate with the ground truth using combined information from IR and darkfield microscopy in a deep learning framework. This chemical-imaging-based workflow for OPMD classification has the potential to enhance the efficiency and accuracy of clinical oral precancer diagnosis. [ABSTRACT FROM AUTHOR]

• Comprehensive study of an alleged forgery of a tempera painting on tile with apparently Botticelli features. • Pigments identification – i.e., iron oxide pigments, cinnabar, carbon black, and calcite) - by combined FORS and Raman spectroscopy. • Pigments mapping by SCM algorithm application to the multispectral image cube. • Colorimetric analysis to quantitatively evaluate the cleaning method and provide support for an informed restoration process. In this work, a tempera painting of uncertain attribution from the Uffizi Galleries was studied. The painting, which portraits a man with apparently Botticellian features, was probably created by one of the most skilled forgers of the early 20th century, Umberto Giunti. He used a flat tile as a support, covered with preparatory layers emulating a wall painting. To shed light on the authorship of the painting, it was crucial to investigate its composing materials, as well as the execution technique and the state of conservation. To this end, non-invasive spectroscopic and imaging optical techniques were applied. Specifically, VIS-NIR multispectral reflectography was used to reveal the presence of possible preparatory drawings, pentimenti and overpaintings. Raman and Fibre Optics Reflectance Spectroscopies allowed identifying the pigments used by the artist. Finally, colour variations due to the cleaning procedure were documented in order to provide a support for an informed restoration process. [ABSTRACT FROM AUTHOR]