Complementary Analytical Techniques Research Articles

Abstract PO3-07-01: Multiscale Computational Analysis of Patient-Matched Multi-Modal Imaging of Breast Tissue Microenvironment

Abstract Introduction: Mammographic breast density is a strong quantitative cancer risk factor, but its link to underlying tissue and cellular level changes are weakly understood. Understanding the complex restructuring changes in the breast tumor microenvironment and its impact on breast density is integral to improving risk assessment and treatment strategies. A novel approach was developed to stratify mammographic dense breast tissue into areas of active dense tissue and passive dense tissue. Active dense tissue is structurally reorganizing and links to cancer dynamics, whereas passive dense mammographic tissue remains organized.1,2 A complementary wavelet-based analysis technique to measure the multiscale anisotropy of collagen fibers from Second-Harmonic Generation (SHG) imaging demonstrated clinical cancer diagnostic potential in mouse carcinoma and human pancreatic cancer.3,4 This tool is now leveraged for a multi-modal study in which patient-matched H&E tissue biopsies are imaged using both bright-field microscopy and SHG imaging to compare with the patient’s corresponding mammograms. Stratifying the mammographic density into active and passive dense areas, a correlation between biopsy tissue anisotropy and mammographic density subtypes can be calculated to help understand how tumor microenvironment changes affect a patient’s mammographic breast tissue composition. Methods: SHG and brightfield-imaged biopsy slides from 10 patients (five malignant, five benign) collected from Maine Medical Center (Maine, US) were analyzed using the 2D Wavelet Transform Modulus Maxima (WTMM) Anisotropy Method generating a large-scale and a small-scale anisotropy factor as well as a scale-combined anisotropy calculated from their large- and small-scale anisotropy separation. A multi-modal anisotropy score was calculated by adding the imaged area’s H&E combined anisotropy score with its respective SHG combined anisotropy score. This analysis was done on eight randomly selected ductal areas for each imaging modality on a slide and correlated with the measured areas of density subtypes from the whole mammographic view. Linear regression was used for determining correlation between H&E and SHG anisotropy factors as well as with active and passive mammographic density subtype measurements. Results: The malignant patients’ small-scale H&E anisotropy factor positively correlated with their small scale SHG anisotropy factor (R2=0.571). No correlation was found for the benign patients (R2=0.011). The strongest correlations were found between benign patients’ mammographic passive (positive correlation) and active (negative correlation) dense tissues vs the H&E anisotropy scale-combined factor (R2=0.858 and R2=0.961, respectively). The largest malignant patient correlation was a negative relationship between SHG anisotropy scale-combined factor and overall mammographic density (inclusive of both active and passive dense tissue) (R2=0.891). The multi-modal anisotropy score correlated with overall mammographic density for both benign (positive correlation, R2=0.698) and malignant patients (negative correlation, R2=0.773). Combining the multi-modal anisotropy factor from SHG and H&E with the active dense tissue measurement using K-Means clustering, 5/5 malignant and 4/5 benign patients were correctly classified. Conclusion: Density in mammograms correlates with underlying quantitative changes in a patient’s tissue and collagen anisotropy. Combining both H&E and SHG analysis on tissue biopsy with active and passive density metrics from computational mammography leads to the best predictive potential than any one method on their own.

Mortars and Renders: The Case of the Roman Villa Horta da Torre Fronteira, Portugal

The archaeological site of villa Horta da Torre in Portugal reveals distinctive architectural features within the context of Roman villae in Hispania. Notably, the triclinium was designed with an artificial cascade originating from a double apse wall, and the walls were adorned with mosaic tessellae panels and marble skirting. During the Roman era, the surrounding area belonged to the former province of Lusitania, with Augusta Emerita serving as its capital. This study examines 11 mortar samples from various contexts and functions, such as masonry, preparatory, render, and opus signinum mortars. A set of complementary analytical techniques was employed to determine the textural and mineralogical compositions of the mortars. The aim was to gain insights into the production techniques and the selection of raw materials within the geological context of this rural construction. It was observed that the processing of raw materials and production techniques did not always adhere to the rules of Vitruvius. A comparison with other villas revealed comparatively less meticulous attention to sand selection and precise layering for mural painting. Nevertheless, it was noted that in preparatory layers for the supranucleus and nucleus tesserae, ceramic pieces were intentionally added to improve the mortar. The binder used was calcitic lime, likely obtained from locally sourced limestone. The nature of aggregates is diversified but consistent with the local geological provenance within a radius of less than 3 km, in accordance with two sand exploration sites. This research aligns with the United Nations’ 2030 Agenda for Sustainable Development, contributing specifically to SDG 11 and Target 11.4, which “aims to strengthen efforts to protect and safeguard the world’s cultural and natural heritage”.

The relevance of the initial conditions in glassy carbon electrode sensing applications: the ferri/ferrocyanide redox reaction model system in aqueous solution

Carbon electrodes, especially the glassy carbon electrodes (GCE) are widely accepted as very versatile sensing platforms. However, correlating the behaviour of the ferri/ferrocyanide redox couple ([Fe(CN)6]3-/4−) with the GCE's surface modification is challenging. The surface modification can be achieved by applying a pre-conditioning electrochemical activation procedure. Hence, we report the investigation performed in order to provide further insights into the electrochemical behaviour of the commonly used redox probe in aqueous solutions. To that aim we took advantage of powerful and complementary electrochemical analytical techniques, like cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Thus, this work highlights the critical role of the GCE initial conditions for optimizing the charge transfer processes and therefore to improve the [Fe(CN)6]3-/4− performance in sensing applications. The best results were obtained in phosphate buffer saline solution with previous electrochemical activation by fast potential cycling between [-0.5 and +1.8] V (vs. Ag|AgCl (KCl sat.)). Finally, one can consider this an eco-friendly and simple procedure to be carried out in the lab, however, its use must be carefully optimized when exploring other systems, as highlighted herein.

Observational Analysis of the Educational Management of Conflicts Between Young Children in the Emmi Pikler Nursery School Using Complementarity of Data Analysis

AbstractConflicts are inevitable in interpersonal relationships. In fact, they are usual in early childhood education centers and, thus, many educators consider them readily available educational tools, particularly valuable for children’s social development if they are constructively managed. In this research, we investigate the educational management of conflicts between young children at Emmi Pikler Nursery School in Budapest. In this early childhood education center, conflict is considered vital for children’s socialization, so the educational management of these episodes aims to support children’s resolution strategies and ultimately promote healthy socialization. The study objectives were: (1) to explore the details of the educator’s behavior in the different moments the conflict goes through; (2) to unravel the temporal distribution of the educational intervention; (3) to discover which behaviors from the conflicted children ―victim and instigator― trigger the intervention; and (4) to deepen in the effect of the intervention in children’s immediate behavior. We applied a systematic observation and used three complementary data analysis techniques to meet the objectives: Lag sequential analysis, T-Pattern detection and Polar coordinate analysis. Results indicate that the educator’s relational behavior is adaptive to the phases of the conflict and that there is a structured temporal distribution within them. Regarding children, particular behaviors from victim and instigator trigger the educator’s intervention and this intervention progressively leads to more adapted behaviors in conflicted children. In conclusion, the studied educational management of conflicts between children proves to be optimal in promoting children’s good behavior and in accompanying their socialization process.

Multi-Technique Characterization of 3.45 Ga Microfossils on Earth: A Key Approach to Detect Possible Traces of Life in Returned Samples from Mars.

The NASA Mars 2020 Perseverance rover is actively exploring Jezero crater to conduct analyses on igneous and sedimentary rock targets from outcrops located on the crater floor (Máaz and Séítah formations) and from the delta deposits, respectively. The rock samples collected during this mission will be recovered during the Mars Sample Return mission, which plans to bring samples back to Earth in the 2030s to conduct in-depth studies using sophisticated laboratory instrumentation. Some of these samples may contain traces of ancient martian life that may be particularly difficult to detect and characterize because of their morphological simplicity and subtle biogeochemical expressions. Using the volcanic sediments of the 3.45 Ga Kitty's Gap Chert (Pilbara, Australia), containing putative early life forms (chemolithotrophs) and considered as astrobiological analogues for potential early Mars organisms, we document the steps required to demonstrate the syngenicity and biogenicity of such biosignatures using multiple complementary analytical techniques to provide information at different scales of observation. These include sedimentological, petrological, mineralogical, and geochemical analyses to demonstrate macro- to microscale habitability. New approaches, some unavailable at the time of the original description of these features, are used to verify the syngenicity and biogenicity of the purported fossil chemolithotrophs. The combination of elemental (proton-induced X-ray emission spectrometry) and molecular (deep-ultraviolet and Fourier transform infrared) analyses of rock slabs, thin sections, and focused ion beam sections reveals that the carbonaceous matter present in the samples is enriched in trace metals (e.g., V, Cr, Fe, Co) and is associated with aromatic and aliphatic molecules, which strongly support its biological origin. Transmission electron microscopy observations of the carbonaceous matter documented an amorphous nanostructure interpreted to correspond to the degraded remains of microorganisms and their by-products (extracellular polymeric substances, filaments…). Nevertheless, a small fraction of carbonaceous particles has signatures that are more metamorphosed. They probably represent either reworked detrital biological or abiotic fragments of mantle origin. This study serves as an example of the analytical protocol that would be needed to optimize the detection of fossil traces of life in martian rocks.

Zeolite‐Based Catalysts for Conversion of Oxygenated Polymer Waste by Positron Annihilation

AbstractPositron Annihilation Lifetime Spectroscopy (PALS) has been employed to investigate the catalysts HZSM‐5 and MESO−Y, which play a pivotal role in catalyzing and upgrading plastics, with a primary focus on oxygenated polymers, thereby transforming existing plastic materials into simpler, higher‐quality value‐added products. In this study, PALS was systematically compared with other complementary analytical techniques. The research outcomes have successfully demonstrated the efficacy of PALS in elucidating the morphology and topology of zeolites at micro/meso‐meter scales.The first experiment focuses on H‐ZSM‐5 zeolite subjected to treatments involving polyurethane and polypropylene. The second experiment delves into H‐ZSM‐5 zeolites with varying Si/Al ratios, both before and after conversion. The third experiment investigates Y zeolites that are surfactant templated to induce meso‐porosity, examining their fresh state as well as their post‐conversion condition.The PALS analysis was supplemented by BET (Brunauer‐Emmett‐Teller) analysis and NMR (Nuclear Magnetic Resonance) spectroscopies. Notably, PALS exhibits superior sensitivity, at the sub‐nanometer scale, suggesting its potential as a preferred complementary method for catalysis studies. In conclusion, the integration of PALS into the repertoire of analytical tools enhances our understanding of catalyst behavior and catalytic processes, offering valuable insights for the advancement of plastic recycling and catalysis research.

Measurements of Dioxygen Formation in Catalytic Electrochemical Water Splitting

Water oxidation is a multielectron complex reaction that produces molecular oxygen as the final product. The article addresses the lack of confirmation of oxygen product formation in electrochemical oxygen evolution reaction (OER) studies, despite the extensive research conducted on catalysts for water splitting. It critically evaluates the trend observed in many studies that solely rely on electrochemical methods for OER quantification without confirming the oxygen product via complementary analytical techniques. The omission of measuring evolved oxygen gas leaves a crucial gap in the quantification of the OER process and raises concerns about the validity and accuracy of reported results. Analytical techniques, such as gas chromatography, Rotating Ring-Disk Electrode (RRDE), fluorescence oxygen probes, Clark electrode, and volumetry are critically analyzed and described to ensure the reliability and credibility of voltammetry and bulk electrolysis to provide a more accurate assessment of the OER process.

Electrochemical Oxidation of Resorcinol: An Integrated Experimental and Theoretical Study

Resorcinol polymerization is a quite important chemical reaction, also in connection with applicative aspects related to the production of industrial resins [1].In this work, we studied the electrochemical oxidation of resorcinol on platinum, palladium and glassy carbon (GC) electrodes. We propose an oxidation-polymerisation mechanism for the resorcinol molecule, which is based on the Kane-Maguire polymerization scheme. The results of an exhaustive electrochemical characterization are integrated with the outcome of complementary chromatographic analytical techniques: LC-DAD (high performance Liquid Chromatography, equipped with Diode Array Detector) and LC-MS (mass-spectroscopy by means of Ion Trap mass analyzer). We demonstrate that upon electrochemical oxidation, resorcinol polymerizes following an efficient and facile process and an organic film is obtained on the electrode surface.We used cyclic voltammetry (CV), and a three-electrode cell to perform electrochemical oxidation. Then we used LC-DAD and LC-MS to study the intermediates involved in the electro-polymerization of resorcinol. Electrochemical experiments were performed under different condition of pH and solvent. CVs in a 0.5M H2SO4 solution shows an irreversible oxidation peak at 1.0 V that is pH dependent, consistent with a one-proton, one electron oxidation reaction. Applying potentials higher than the oxidation potential we obtained an organic film adhering to the electrode surface [2]. The polymer film was characterized by atomic force microscopy (AFM) and Scanning Electron Microscopy combined with Energy-Dispersive X-ray spectroscopy (SEM-EDS).We also perform a theoretical study on the first steps of resorcinol electro oxidation using ab-initio quantum mechanical based methods and molecular dynamics analysis (DRC algorithm) at the B3LYP/6-31G(d) and B3LYP/cc-pVTZ level of theory [3]. The resorcinol polymerization is considered to proceed via the dissociation of one (or two) hydrogen atom to form C-C and C-O dimers.The proposed mechanism for the resorcinol electrochemical oxidation is fully consistent with experimental results. Moreover, the film obtained on the electrode surface could be a potential substrate for electrodepositions or electroless deposition of metals and could be a promising candidate for the development of new materials of technological and industrial interest.[1] Formaldehyde and Phenol-Resorcinol-Formaldehyde Condensation Reactions: A Theoretical Study. Polymers 2017, 9, 426, doi:10.3390/polym9090426.[2] Bonechi, M.; Giurlani, W.; Stefani, A.; Marchetti, A.; Innocenti, M.; Fontanesi, C. Resorcinol Electropolymerization Process Obtained via Electrochemical Oxidation. Electrochimica Acta 2022, 428, 140928, doi:10.1016/j.electacta.2022.140928.[3] Bonechi, M.; Innocenti, M.; Vanossi, D.; Fontanesi, C. The Fundamental and Underrated Role of the Base Electrolyte in the Polymerization Mechanism. The Resorcinol Case Study. J. Phys. Chem. A 2021, 125, 34–42, doi:10.1021/acs.jpca.0c07702.

Assessment of the occurrence and interaction between pesticides and plastic litter from vineyard plots

In this research, aged plastic fragments collected from vineyards were characterized in terms of composition, residues of pesticides, and their potential to exchange these compounds with the aquatic media. To this end, we employed the qualitative and quantitative information provided by complementary analytical techniques, including chromatography, organic and inorganic mass spectrometry, infrared spectroscopy and electronic microscopy. Debris of weathered plastics were identified as polypropylene and polyethylene, containing different types of additives, from organic UV stabilizers to inorganic fillers, such as calcium salts. Regardless of polymer type, plastic litter collected from vineyards contained residues of pesticides, and particularly of fungicides, with total concentrations in the range of values from 114 ng g−1 to 76.4 μg g−1. Data obtained under different extraction conditions suggested that a fraction of these compounds was absorbed in aged polymers, penetrating inside the material. The parallel analysis of plastic litter and vineyard soils reflected higher pesticide residues in the former matrix. Furthermore, several fungicides, considered as labile in vineyard soils (i.e. zoxamide and folpet), were those showing the highest levels in plastic litter. Simulated sorption-desorption studies, with plastic debris in contact with surface water, demonstrated the higher affinity of aged materials by moderately polar pesticides than their new counterparts. For the first time, the manuscript highlights the presence of plastic litter in vineyards soils, reflecting the accumulation of several fungicides in this matrix, in some cases, with a different stability pattern to that observed in the soil from same vineyards.

CPO and quantitative textural analyses within sheath folds

We investigate the intra- and inter-crystalline deformation processes involved in sheath fold development combining complementary fabric analysis techniques and 3D modelling by neutron tomography. The investigated sheath fold is a multi-layered sub-metre scale single-eye structure, developed in metapsammites from the Ben Hope Nappe, overlying the Moine Thrust Zone of NW Scotland. Crystallographic Preferred Orientations (CPOs) of quartz and biotite were acquired through a Neutron Diffractometer and an SEM-EBSD system to compare the full-fabric of the main phases and the active slip systems for an “in situ” structural control. Combined with orientation maps and grain size maps, results show that, despite the different structural positions of the investigated microdomains (upper vs lower fold limbs, inner vs outer sheath closures, distance from hinge of the sheath fold), quartz and biotite deformed uniformly, suggesting a constant differential stress and orientation of the kinematic vorticity axis. Previously recognized detachment horizons within the sampled sheath fold do not affect the fabric patterns recorded by quartz and biotite. This may be interpreted in two different ways: i) detachments formed during earlier active folding and prior to passive amplification of folds associated with more uniform flow to create the sheath fold geometries; ii) the quartz c-axis patterns are coeval with a late deformation phase (loading of the orogenic wedge) that pervasively obliterated the previous fabric and therefore did not preserve the active folding component. Several pieces of evidence reported here, such as top-to-SE normal-shear sense which is opposite to the regional kinematics, are more supportive of the second hypothesis. The analysis of mineral textures provides an improved dataset for the whole sheath fold and increases our understanding of recrystallization mechanisms active in shear zones.

Application of digital image processing to mortar crack analysis

Image analysis techniques can be used to detect and interpret the degradation processes that a material undergoes and to help identify the causes and mechanisms of degradation. Structures and morphological changes are also analysed to establish hypotheses about physical changes. Together with complementary analytical techniques, chemical and mineralogical changes can be evaluated.The methodological process consists of a sequential simplification of the initial micrograph: segmentation of the image, cleaning and isolation of the crack from associated elements, and crack skeletonisation. This method allows the previous image to be processed, thus successfully isolating the microcracks. It is also valid for their quantification.

SEI growth on Lithium metal anodes in solid-state batteries quantified with coulometric titration time analysis

Lithium-metal batteries with a solid electrolyte separator are promising for advanced battery applications, however, most electrolytes show parasitic side reactions at the low potential of lithium metal. Therefore, it is essential to understand how much (and how fast) charge is consumed in these parasitic reactions. In this study, a new electrochemical method is presented for the characterization of electrolyte side reactions occurring on active metal electrode surfaces. The viability of this new method is demonstrated in a so-called anode-free stainless steel ∣ Li6PS5Cl ∣ Li cell. The method also holds promise for investigating dendritic lithium growth (and dead lithium formation), as well as for analyzing various electrolytes and current collectors. The experimental setup allows easy electrode removal for post-mortem analysis, and the SEI’s heterogeneous/layered microstructure is revealed through complementary analytical techniques. We expect this method to become a valuable tool in the future for solid-state lithium metal batteries and potentially other cell chemistries.

IRIS: A novel integrated instrument for co‐registered MA‐XRF mapping and VNIR‐SWIR hyperspectral imaging

AbstractThe combination of complementary techniques for materials analysis can play a key role in both art conservation and academic research. Nowadays, the correlation of x‐ray fluorescence (XRF) with hyperspectral reflectance imaging in the visible and infrared region has become a valuable tool for palette identification, painting techniques studies and for the diagnostic support dedicated to restoration and conservation. Moreover, both techniques enable researchers to reveal fascinating underpaintings, “pentimenti”, or even preparatory drawings offering new details on the creative process of the artist. This background has been a strong motivation for the development of a new multimodal tool for art and conservation: IRIS. IRIS is a mobile and reconfigurable scanner designed to address a wide range of demanding application, exploiting the opportunities given by simultaneous MA‐XRF and hyperspectral reflectance scanning in the visible‐near‐infrared (VNIR) and short‐wave‐infrared (SWIR) range from 400 to 2500 nm. The system has been designed for in‐situ, fast and non‐invasive scanning of the sample without compromising spectral resolution and high throughput performance. The scanner acquires co‐registered XRF/VNIR‐SWIR data, thus allowing the user to obtain the maximum profit from their possible correlated information: the two techniques can provide enhanced or complementary information on the same spot of analysis with minimum effort in terms of data processing and no need for spatial alignment. In the present work, the qualitative and quantitative performance of IRIS are explored, together with the presentation of in‐lab analysis on reference samples and a brief insight on a real case‐study.

The role of impurities in porous carbons for bioinspired iontronic devices

Ion-controlled electronics use biocompatible electrolytes to realize multiple functions, such as ionic resistors, ionic diodes, and ionic transistors, endowing them with huge biologic application potentials, ranging from sensing to information processing. Biocompatible porous carbons with exceptionally high surface areas enable high capacitance for biologic ions electric-double-layer capacitive devices. However, we find an unexpectedly high content of water-soluble ionic impurities in commercial and custom designed carbons, which affects the capacitive behavior of carbons in the pure water electrolyte and thereby affects the precise control of ions transport induced by electric polarization of porous carbon electrodes. Complementary analytical techniques are used to analyze the commercial clean activated carbon ColorSorb (AC-CS) illuminating the influence of adsorbed ionic impurities for the electrosorption mechanism in a low concentrated bioactive choline chloride (ChCl) electrolyte. Moreover, the comparison of high purity activated carbon (AC-HP) with pure AC-CS suggests the roles of ionic impurities for the capacitive behavior in ChCl and pure water electrolytes. Our work encourages to reconsider the importance of adsorbed ionic impurities for the carbon’s property and application in capacitive devices, and clarifies the influence of ionic impurity release from porous carbon for ion depletion and release processes.

Measuring the Interactions and Influence of Amphipathic Copolymers with Lipid Monolayers and Bilayers as Models of Biological Membranes

AbstractAmphipathic copolymers are useful materials for nanomedicine, owing to their ability to self‐assemble into nanoparticles, act as surfactants for inorganic materials, or for their favorable interactions with lipid membranes. Despite their widespread use, there is still a range of questions about the physicochemical properties that are necessary to drive their interactions at biological interfaces. To fully understand these interactions requires a diverse range of complementary analytical techniques. In this work, a library of neutral amphipathic methacrylate copolymers is synthesized by reversible addition‐fragmentation chain‐transfer polymerization (RAFT) polymerization, to investigate the effect of polymer composition and nature of the hydrophobic comonomer on interactions with model lipid membranes. These materials are shown to interact with Langmuir lipid monolayers, and neutron reflectometry demonstrates that hydrophobic interactions lead to the polymers intercalating with the monolayers. More complex models of lipid bilayers are studied using an in situ quartz crystal microbalance (QCM) model and shows while the composition and hydrophobic comonomer affect the stability of these interactions, there is no effect on the viscoelasticity of the lipid membranes. The in‐depth understanding of these interfacial interactions afforded by this suite of analytical tools will allow for more complex copolymers to be studied, providing a greater understanding of key processes in nanomedicine, such as cellular entry and endosomal escape.

Evolution of Morphology and Distribution of Salt Crystals on a Photothermal Layer during Solar Interfacial Evaporation.

Solar interfacial evaporation (SIE) by leveraging photothermal conversion could be a clean and sustainable solution to the scarcity of fresh water, decontamination of wastewater, and steam sterilization. However, the process of salt crystallization on photothermal materials used in SIE, especially from saltwater evaporation, has not been completely understood. We report the temporal and spatial evolution of salt crystals on the photothermal layer during SIE. By using a typical oil lamp evaporator, we found that salt crystallization always initiates from the edge of the evaporation surface of the photothermal layer due to the local fast flux of the vapor to the surroundings. Interestingly, the salt crystals exhibit either compact or loose morphology, depending on the location and evaporation duration. By employing a suite of complementary analytical techniques of Raman and infrared spectroscopy and temperature mapping, we followed the evolution and spatial distribution of salt crystals, interfacial water, and surface temperature during evaporation. Our results suggested that the compact crystal structure may emerge from the recrystallization of salt in an initially porous structure, driven by continuous water evaporation from the porous and loose crystals. The holistic view provided in this study may lay the foundation for effective strategies for mitigation of the negative impact of salt crystallization in solar evaporation.

Development of Simplified and Efficient Sample Preparation Methods for the Analysis of Problem Material within the Diesel Fuel Delivery System.

A new approach for the analysis of diesel engine fuel filters has been developed. This method involves minimal to no sample preparation, allowing rapid and unbiased analysis of diesel fuel filters. In recent years, diesel fuel filter plugging incidences have increased in parallel with changing emissions legislation. Fuel filter blockages can result in increased emissions, reduced efficiency, and engine failure. It is not fully understood why fuel filter blockages occur; as a result, there has been an international increase in research into the cause of fuel filter plugging. The method discussed in this paper utilizes a thermal desorption (TD) style sample introduction technique that can be used in conjunction with gas chromatography-mass spectrometry (GC-MS) and presents a fast, simple, and more sustainable approach to the analysis of fuel filters. When required, an efficient and straightforward sample cleanup process was developed and was used to simplify and improve confidence in the data identification and assignment; this method is up to three orders of magnitude faster than some procedures adopted in the literature. Further complementary analytical techniques, such as ultrahigh-performance supercritical fluid chromatography-mass spectrometry (UHPSFC-MS) and high-resolution GC-MS, were used to access additional sample-specific information. This new approach has been successful in the identification of problematic materials deposited on blocked fuel filters, concurrent with recent research. This information can aid in the development of mitigation strategies to combat fuel filter plugging.

2-NBDG Uptake in Gossypium hirsutum in vitro ovules: exploring tissue-specific accumulation and its impact on hexokinase-mediated glycolysis regulation.

Fluorescent glucose derivatives are valuable tools as glucose analogs in plant research to explore metabolic pathways, study enzyme activity, and investigate cellular processes related to glucose metabolism and sugar transport. They allow visualization and tracking of glucose uptake, its utilization, and distribution within plant cells and tissues. This study investigates the phenotypic and metabolic impact of the exogenously fed glucose derivative, 2-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-2-deoxyglucose) (2-NBDG) on the fibers of Gossypium hirsutum (Upland cotton) ovule in vitro cultures. The presence of 2-NBDG in the culture medium did not lead to macroscopic morphological alterations in ovule and fiber development or to the acquisition of fluorescence or yellow coloration. Confocal laser scanning microscope imaging and chromatographic analysis of cotton ovules' outer rim cross-sections showed that the 2-NBDG is transported from the extracellular space and accumulated inside some outer integument cells, epidermal cells, and fertilized epidermal cells (fibers), but is not incorporated into the cell walls. Untargeted metabolic profiling of the fibers revealed significant changes in the relative levels of metabolites involved in glycolysis and upregulation of alternative energy-related pathways. To provide biochemical and structural evidence for the observed downregulation of glycolysis pathways in the fibers containing 2-NBDG, kinetics analysis and docking simulations were performed on hexokinase from G. hirsutum (GhHxk). Notably, the catalytic activity of heterologously expressed recombinant active GhHxk exhibited a five-fold decrease in reaction rates compared to D-glucose. Furthermore, GhHxk exhibited a linear kinetic behavior in the presence of 2-NBDG instead of the Michaelis-Menten kinetics found for D-glucose. Docking simulations suggested that 2-NBDG interacts with a distinct binding site of GhHxk9, possibly inducing a conformational change. These results highlight the importance of considering fluorescent glucose derivatives as ready-to-use analogs for tracking glucose-related biological processes. However, a direct comparison between their mode of action and its extrapolation into biochemical considerations should go beyond microscopic inspection and include complementary analytical techniques.

Hydrogen-Rich Gas Production by Steam Reforming and Oxidative Steam Reforming of Methanol over La0.6Sr0.4CoO3-δ: Effects of Preparation, Operation Conditions, and Redox Cycles.

La0.6Sr0.4CoO3-δ (LSC) perovskite, as a potential catalyst precursor for hydrogen (H2)-rich production by steam reforming of methanol (SRM) and oxidative steam reforming of methanol (OSRM), was investigated. For this purpose, LSC was synthesized by the citrate sol-gel method and characterized by complementary analytical techniques. The catalytic activity was studied for the as-prepared and prereduced LSC and compared with the undoped LaCoO3-δ (LCO) at several feed gas compositions. Furthermore, the degradation and regeneration of LSC under repeated redox cycles were studied. The results evidenced that the increase in the water/methanol ratio under SRM, and the O2 addition under OSRM, increased the CO2 formation and decreased both the H2 selectivity and catalyst deactivation caused by carbon deposition. Methanol conversion of the prereduced LSC was significantly enhanced at a lower temperature than that of as-prepared LSC and undoped LCO. This was attributed to the performance of metallic cobalt nanoparticles highly dispersed under reducing atmospheres. The reoxidation program in repetitive redox cycles played a crucial role in the regeneration of catalysts, which could be regenerated to the initial perovskite structure under a specific thermal treatment, minimizing the degradation of the catalytic activity and surface.

Microcomputed tomography visualization and quantitation of the pulmonary arterial microvascular tree in mouse models of chronic lung disease.

Pulmonary vascular dysfunctionis characterized by remodeling and loss of microvessels in the lung and is a major manifestation of chronic lung diseases (CLD). In murine models of CLD, the small arterioles and capillaries are the first and most prevalent vessels that are affected by pruning and remodeling. Thus, visualization of the pulmonary arterial vasculature in three dimensions is essential to define pruning and remodeling both temporally and spatially and its role in the pathogenesis of CLD, aging, and tissue repair. To this end, we have developed a novel method to visualize and quantitate the murine pulmonary arterial circulation using microcomputed tomography(µCT) imaging. Using this perfusion technique, we can quantitate microvessels to approximately 6 µM in diameter. We hypothesize that bleomycin-induced injury would have a significant impact on the arterial vascular structure. As proof of principle, we demonstrated that as a result of bleomycin-induced injury at peak fibrosis, significant alterations in arterial vessel structure were visible in the three-dimensional models as well as quantification. Thus, we have successfully developed a perfusion methodology and complementary analysis techniques, which allows for the reconstruction, visualization, and quantitation of the mouse pulmonary arterial microvasculature in three-dimensions. This tool will further support the examination and understanding of angiogenesis during the development of CLD as well as repair following injury.