Characterization Of Composition Research Articles

Alteration of Immune Function and Gut Microbiome Composition in Carassius auratus Challenged With Rahnella aquatilis.

Rahnella aquatilis as an emerging pathogen can cause bacterial enteritis in cyprinid fish such as crucian carp Carassius auratus. Currently, the characterisation of immune function and gut microbiome composition in C. auratus orally challenged by R. aquatilis were yet unknown. In this study, we therefore investigated the changes of histopathology, white blood cells (i.e., LEU, NEU and LYM), serum biochemical indicators (e.g., CRE, CK and CHO) and digestive enzyme activity (e.g., LYS, AST, ALT, GSH-Px and AKP), as well as complements and immune-related genes (e.g., C3, F2, LysC, TLR3, MyD88, TGF-β, TNF-α and IL-15) that were significantly altered after the oral administration of R. aquatilis KCL-5. Moreover, the gut microbiome composition and diversity were analysed by using 16S rRNA gene high-throughput sequencing analysis. The correlation analysis showed that the high abundance of phylum Proteobacteria, Actinobacteria, Firmicutes and Fusobacteria was related to the pathogenesis of enteritis caused by oral infection. KEGG enrichment analysis indicated that fatty acid, carbon and pyruvate metabolism were significantly increased pathways (p < 0.05). To our best knowledge, this is a rare report of physicochemical properties and gut microbiome in C. auratus by R. aquatilis infection, which will provide a scientific reference for the clinical diagnosis and prevention of bacterial enteritis in cyprinid fish.

Hydrogeochemical Characterization and Processes Controlling Groundwater Chemistry of Complex Volcanic Rock of Jimma Area, Ethiopia

The sustainable management of groundwater in the Jimma area is complicated by a lack of comprehensive studies on its chemical makeup and the geochemical processes influencing its hydrochemistry. This research aims to fill that gap by examining 51 groundwater samples from various sources, including deep groundwaters, shallow groundwaters, hand-dug well groundwaters, surface waters, and springs within the area primarily consisting of complex volcanic rocks. The goal is to describe the hydrogeochemical characteristics and determine the key processes affecting groundwater composition in this volcanic area. The study identifies clear patterns in cation and anion concentrations. For deep groundwaters, the average cation concentration is ranked as Na+ &gt; Ca2+ &gt; Mg2+ &gt; K+, while shallow groundwaters, hand-dug well groundwaters, surface waters, and springs show a ranking of Ca2+ &gt; Na+ &gt; Mg2+ &gt; K+. The major anions are typically ordered as HCO3− &gt; NO3− &gt; Cl− &gt; SO42−. The quantitative hydrogeochemical analysis indicates that the freshwater types in the region are primarily Ca-HCO3 and Ca-Mg-HCO3, with some highly mineralized Na-HCO₃ waters also detected. The weathering of silicate minerals mainly drives the geochemical processes affecting groundwater chemistry. An increase in mineralization, suggested by saturation indices, points to a longer residence time underground, with deep groundwaters exhibiting the highest saturation levels and springs the lowest. This mineralization is especially significant for Mg-silicates and carbonates. Stability diagrams for feldspar minerals further demonstrate groundwater evolution along flow paths, revealing that shallow systems are in equilibrium with minerals like gibbsite, whereas deeper systems achieve stability with albite, Ca-montmorillonite, and microcline. Higher CO2 levels (10−1.5 to 100.5 atm), likely from mantle-magma degassing, add more HCO3− to the deeper aquifers. This study offers the first thorough characterization of the groundwater composition in the Jimma area and provides important insights into the Jimma area’s hydrogeochemical development, establishing a basis for enhanced groundwater management within this intricate volcanic aquifer system.

Novel core-layer-shell structured nano-composite precipitates formed in selective laser melted reduced activation ferritic-martensitic steel

A novel type of core-layer-shell structured nano-composite precipitates was identified for the first time in a typical reduced activation ferritic-martensitic steel fabricated via selective laser melting (SLM). Comprehensive characterization of morphology, composition and structure was achieved for them using high-resolution electron microscopy. Their formation mechanism is closely related to specific processing features of SLM: the core consists of a triclinic SiO2 nanoparticle (~10nm in diameter), resulting from the combination of Si and O in the powder melting stage; the middle layer corresponds to an MC-type carbide (~10-nm-thick) formed due to preferential nucleation at the SiO2/matrix interface during rapid cooling; the shell is an orthorhombic Cr7C3 carbide, which arises from thermally activated C and Cr diffused continuously to the MC/matrix interface due to the in-situ heat treatment during cyclic SLM scanning. This unique type of precipitate is believed to exert a significant influence on the mechanical properties of RAFM steels.

Intra-rater Reliability of B-mode Ultrasound in the Measurement of Soft Tissue Thickness and Composition over the Lateral Proximal Femur

ObjectivesComprehensive characterization of soft tissue composition and distribution over the lateral proximal femur is necessary to improve our understanding of fall-related hip fractures; however, a protocol that produces reliable data is needed. Accordingly, the aim of this study was to assess the intra-rater reliability of B-mode ultrasound measured muscle, adipose, and total soft tissue thicknesses over the lateral proximal femur in a simulated sideways fall configuration. MethodsTwenty-five young adults (12 males, 13 females, age (SD) = 20.8 (1.9) years) underwent B-mode ultrasound imaging of 12 locations over their lateral proximal femur while in a side-lying position. Side-lying was chosen to allow imaging of the tissues impacted during a lateral fall event. Muscle, adipose, and total soft tissue thicknesses were measured at each location (further grouped into posterolateral, lateral, and anterolateral locations for statistical analysis) and two-way mixed model absolute agreement intraclass correlation coefficients (ICCs) and standard error of measurement were used to assess reliability of tissue type, location, and sex. ResultsICCs were excellent (ICC > 0.9) for each tissue type, measurement location, and sex. There were interactions between tissue type, measurement location, and sex on reliability. While measures of adipose thickness were excellent across all conditions, reliability of muscle and total soft tissue thickness measurements were dependent on measurement location and sex. ConclusionsThis ultrasound imaging protocol demonstrated good-to-excellent reliability of soft tissue-specific thickness measurements over the lateral proximal femur. This protocol has implications for subject-specific hip fracture risk screening tools and biomechanical models of impact dynamics that incorporate biofidelic soft tissue morphology.

Characterization and Optimization of Dielectric Phantom Composition for Frequency-Dependent Tissue Mimicking

Dielectric phantoms are essential for testing and validating medical imaging techniques and various treatments because they can mimic and validate the electromagnetic characteristics of biological tissue. With an established dielectric phantom recipe, phantoms with desired dielectric properties can be fabricated. However, these recipes are typically designed for specific frequencies, such as 128MHz, which poses a challenge for obtaining phantoms for other frequencies. In this study, a total of 184 dielectric phantoms were fabricated to explore the relationship among dielectric properties, composition, and frequency across a range from 16MHz to 3GHz. Based on artificial neural networks, dielectric phantom recipes were derived across a broad frequency range. To ensure the accuracy of the dielectric recipe, we fabricated 16 phantoms containing blood, muscle, skin, and lung tissues at 128MHz, 298MHz, 915MHz, and 2.45GHz, and then measured their properties. The relative errors compared to the literature values were within 15%. These dielectric recipes can be utilized to fabricate phantoms with dielectric properties equivalent to biological tissues for testing and validating applications in medical imaging and various treatments.

Possible Superconductivity Transition in Nitrogen-Doped Lutetium Hydride Observed at Megabar Pressure.

The pursuit of room-temperature superconductivity at an accessible synthetic pressure has been a long-held dream for both theoretical and experimental physicists. Recently, a controversial report by Dasenbrock-Gammon et al. claims that the nitrogen-doped lutetium trihydride exhibits room-temperature superconductivity at near-ambient pressure. However, many researchers have failed to independently reproduce these results, which has sparked intense skepticism on this report. In this work, a LuH2±xNy sample is fabricated using high-pressure and high-temperature methods. The composition and structural characterization are the same as the aforementioned near-ambient superconductor. In situ X-ray diffraction investigations indicate that a high-pressure phase transition toward Fm m-LuH3±xNy occurred in the sample at 59GPa. The temperature-dependent resistance measurements reveal that two possible superconductivity transition are observed at 95GPa, with Tc1 ≈6.5 K for high-Tc phase and Tc2 ≈2.1 K for low-Tc phase, arising from the disparate phases in the sample. Resistivity measurements in the Fm m-LuH3±xNy phase under varying magnetic fields exhibited characteristics consistent with superconductivity, with an upper critical field μ0Hc2(0) of 3.3 T measured at 163GPa. This work is expected to shed some light on the controversy surrounding superconductivity in the nitrogen-doped lutetium hydride system.

Cooking pottery as indicator of resilience and change in Early Medieval Cyprus. An archaeometric approach

The early medieval times in Cyprus are signified, conventionally, by the Arab invasions of the mid-seventh century (649/650CE). Past research viewed those events as the catalyst which led to a transformation from a prosperous province to a marginal territory balancing between two antagonising empires. Recently, studies have shifted their focus on reassessing this period’s scant -yet present- material culture. In pottery studies, despite the advances in typological and distribution aspects, few have explored technological issues of early medieval ceramic production through instrumental analysis. This study focuses on the compositional and technological characterisation of cooking vessels through ceramic petrography (TL-OM), found in relevant contexts in Cyprus, representing both wheel-thrown and handmade traditions. Sherds coming from five major early-medieval sites of the island (sites of Kophinou, Kalavasos-Kopetra, Akrotiri, Yeroskipou-Ayioi Pente and Dhiorios), outlined a picture of two parallel trends transversing across sites, i.e., an inter-regional shared sense of shape uniformity smoothening the local variances and a strong regionalism in terms of raw material procurement. Wheel-thrown cookware -found in every site and strongly represented by the Dhiorios workshop- showed the survival of Late Antique shapes well into the Early Middle Ages, in fabrics related mainly to the broader area of Dhiorios. In addition, handmade vessels of a "shared repertoire" showed a variety of local clays for their manufacture. When integrated into their archaeological context in Cyprus, the results support the idea of a ceramic koine persisting through the beginning of the Byzantine Early Middle Ages on an intra and inter-regional level.

Potential influence mechanism of mineral–organic matter (OM) interactions on the mobility of toxic elements in Pb/Zn smelter contaminated soils

To date, how complex mineral–organic matter (OM) interactions affect the migration and mobility of potentially toxic elements (PTEs) in soils is highly understudied. This work mainly focused on the occurrence characteristics of PTEs and their close association with the composition characterization of mineral elements and dissolved OM (DOM) molecules. The results revealed that quartz (20.20%), albite (15.60%) and biotite (14.37%) were the dominant minerals in soils. CHO molecules were most abundant, accounting for 58.41%. The unsaturated hydrocarbons with both low and high O/C ratios were the dominant organic compounds, accounting for 21.56% and 36.73%, respectively. Sequential extraction results indicated that most Cd was hosted in carbonate minerals, while considerable amounts of As, Cu, Mn, Pb and Zn were bound to Fe/Mn oxyhydroxides. The elemental distribution characteristics displayed the coexistence of As, Cd, Cu, Mn, Pb and Zn with O, S, Al, Si, Ca and Fe. Fe oxyhydroxides might preferentially retain the unsaturated hydrocarbons with low O/C ratio and phenols. Furthermore, Fe oxide–organic composites had more significant impacts on Mn than As, Cd, Cu, Pb and Zn mobility. Overall, these findings would provide important insights into how mineral–OM interactions played the key roles on PTEs mobility in soils.

Combinatorial sputtering synthesis of TbCu7-type Sm-Fe based compounds: A study on phase, composition, and extrinsic magnetic properties

We investigated the effect of composition on the phase and extrinsic magnetic properties of TbCu7-type SmFe-based compounds using a combinatorial sputtering technique. Composition-spread thin films of SmFex (x=6.4–12.7) and SmFexN (x=6.8–12.8) were synthesized using a linear shutter-assisted combinatorial sputtering technique. A high-throughput composition, phase, and magnetic characterization were performed on 18 different locations along the film using X-ray diffraction (XRD), X-ray fluorescence (XRF), and magneto-optical Kerr effect (MOKE) magnetometry. The optimal composition with the highest fraction of the main phase was found to be in SmFe9.8 and SmFe9.5N and beyond this composition, the α-Fe secondary ferromagnetic phase emerges. The coercive field and remanence of the SmFe9.5N are estimated to be ∼0.8 T and ∼1.2 T, respectively. Further, scanning transmission electron microscopy (STEM) was performed at SmFe9.5N to correlate the microstructure with their extrinsic magnetic properties. Overall, this study demonstrates the impact of composition variation on the phase and extrinsic magnetic properties of TbCu7-type SmFe-based compounds, which can be utilized to tailor magnetic properties for targeted advanced magnet applications.

Abstract B029: Mapping the vascular walls of colorectal cancer

Abstract Introduction: Properties of tumor angiogenesis impact on tumor growth and composition of the tumor microenvironment. Tumor vessels are composed of pericytes and other mural cells. Detailed characterization of the cellular composition of the microvasculature can suggest functional vessel and case properties relevant for outcome, response to treatment and immune surveillance. Results: Based on single cell RNA-seq from three human stage II/III colon cancers and pilot in-situ multi-antibody staining of six tumors two main clusters of perivascular cells were identified; B1 (MCAM+, MYH11-) and B2 (MCAM+, MYH11+) cells. B1 cells displayed pericyte features including expression of RGS5, whereas B2 cells showed high expression of smooth muscle cell markers like ACTG2 and Desmin. Desmin-high B2 cells were predominantly located in muscular layers, whereas Desmin-low/MYH11-high B2 cells showed perivascular enrichment. An extended novel analyses workflow of digital image analysis was used to profile peri-endothelial composition in 19 intervals; 11 1-µm intervals from 0 to 10 µm and 8 5-µm intervals from 10 to 50 µm from endothelial areas. Each of these expansion areas was quantitated regarding density of PDGFRB+/- cells including B1/B2 cells, and a MYH11+/MCAM- cells. Density of macrophage subsets (CD68-positive subsets defined by CD163 and CD11c) were also quantitated. In general, B1 cells showed stronger spatial association with endothelial cells than B2 cells, and this spatial association was stronger for the PDGFRB+ B1 subset. Survival analysis indicated that prognostic relevance was strongest when PDGFRB+ (favorable prognosis) cells were closest to endothelial cells. Regarding perivascular macrophage density, M0 and transit M1/M2 macrophages were predominantly enriched in the peri-endothelial regions, whereas density of M1 and M2 increased gradually as distance from vessels increased. M2 density was overall associated with poor prognosis, whereas high density of other macrophage subsets overall was associated with good prognosis. Ongoing studies are using a clustering-based approach to identify vessel subsets, and prognosis associations are being consolidated in additional cohorts. Summary: This study provides a novel approach for high resolution profiling of perivascular status in CRC, and possibly other tumor types, that could be of specific importance to identify tumor features associated with response to angiogenesis-directed therapies. Citation Format: Linglong( 凌 龙 ) Huang( 黄 ), Mercedes Herrera, Jonas Sjölund, Vladimir Chocoloff, Simon Joost, Rasul M. Tabiev, Lina Wik Leiss, Carina Strell, Luis Nunes, Artur Mezheyeuski, David Edler, Anna Martling, Fredrik Pontén, Bengt Glimelius, Tobias Sjöblom, Maria Kasper, Kristian Pietras, Arne Östman. Mapping the vascular walls of colorectal cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr B029.

Characterisation of ginsenosides composition in processed American ginseng products using UPLC-MS coupled with chemometric analysis

American ginseng(Panax quinquefolius L.), a traditional herbal extensively utilised in China, exhibits both medicinal and food properties. Diverse processing American ginseng gain extensive utilisation in China. In this study, we used to UPLC-Q-Orbitrap-MS to identify the compositions of diverse processed products of American ginseng, resulting in the identification of a total of 49 compounds. The utilisation of 18 of these ingredients enables the discrimination among diverse processed forms of American ginseng. The application of chemometric reveals notable disparities in the chemical compositions among various processed products. The result showed that chemical composition combined with chemometric is effectively and accurately to identify diverse American ginseng prepared products.

Multispectral Imaging and Spectral Unmixing for Characterization of Relative Phase Composition of Steel Corrosion Products

Multispectral Imaging and Spectral Unmixing for Characterization of Relative Phase Composition of Steel Corrosion Products

Characterization of the Elemental Composition of Aerosols Emitted in the Dry Season of the Pantanal Wetland, Brazil

The Brazilian Pantanal region experiences intense biomass burning during the dry season, releasing large quantities of gasses and particles into the atmosphere, which have serious implications on both the climate system and public health. Understanding the dynamics of these emissions is crucial for mitigating the impact on the ecosystem, its functioning, and potential anthropogenic disturbances. This study focused on analyzing emissions in the northern Pantanal during the 2022 drought. Concentrations of fine particulate matter (PM2.5), black carbon (BC), and 25 chemical elements were measured using gravimetry, reflectance analysis, and X-Ray fluorescence, respectively, from samples collected between August and October 2022. The average concentrations of PM2.5 and BC increased approximately 4-fold and 2.5-fold, respectively, compared to averages from a decade ago. Significant increases were also observed in elements such as sulfur (S), potassium (K), iron (Fe), and silicon (Si). The maximum concentrations were comparable to values typical of the southern Amazon, a region known for high deforestation rates and land use changes. Elemental analysis revealed substantial shifts in concentrations, primarily associated with biomass burning (BB) and soil suspension. Additionally, enrichment factor (Ef) analysis showed that lead (Pb) levels, correlated with human activities, were 200 times higher than those found under clean atmospheric conditions.

Characterization of oil body microstructure, accumulation level and chemical composition in walnut fruit during growth

Oil body (OB) is composed of phospholipids, proteins and neutral lipids. However, the changes of these components in walnut OB (WOB) during walnut growth have not been studied. In this paper, CLSM, TEM and LC-MS/MS were used to observe and quantify the microstructure, accumulation level and biochemical composition of WOB during the growth of walnut (Wen 185 cultivar). The results showed that WOB accumulated near the cell wall on day 60 and then toward the center of cell until it occupied the entire cell on day 88. Afterwards, the WOB began to grow and fuse. Analysis of the chemical composition of WOB indicated that phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, and phosphatidylserine and oleosins, caleosins, and steroleosins made up the WOB membrane. The core of the WOB consisted of 22 free fatty acids and monoacylglycerol, diglyceride, triglyceride. Phosphatidylcholine, triglyceride and oleosin contents continued to increase. The contents of phosphatidylglycerol, unsaturated fatty acids, caleosins and steroleosins continued to decline. The content of phosphatidylethanolamine, phosphatidylinositol and phosphatidylserine remained basically unchanged. These findings provided a basis for understanding the dynamic pattern of WOB bioaccumulation in walnut kernel at different developmental stages.

Comparison of polysaccharides from stem barks and flowers of Magnolia officinalis: Compositional characterization, hypoglycemic and photoprotection activities.

The extraction of polysaccharides from stem barks and flowers of Magnolia officinalis were optimized using response surface methodology and the maximum yields were 4.12 ± 0.06 % and 5.5 ± 0.08 %, respectively. Three homogeneous polysaccharides including MOBP-I, MOBP-II and MOFP-I were further purified and their compositional characterization were compared. Molecular weights of MOBP-I, MOBP-II and MOFP-I were 5.9 × 103, 6.8 × 103 and 3.9 × 104 Da, respectively. Gas chromatography (GC) analysis suggested that MOBP-I, MOBP-II and MOFP-I were composed of rhamnose, arabinose, mannose, glucose and galactose at different ratios and exhibited different appearance and glycosidic linkages. MOFP-I but not MOBP-I and MOBP-II had three helix structures. MOBP-I, MOBP-II and MOFP-I showed significant hypoglycemic and photoprotection capacities with different efficacy. MOBP-I had greater hypoglycemic activity, as evidenced by the increased α-glucosidase inhibition activity and glucose consumption in insulin-resistant HepG2 cells. MOBP-II and MOFP-I were more powerful in reversing ultraviolet-B (UVB)-irradiated photoaging of HaCaT cells. The difference of polysaccharides compositions might explain for their bioactivity discrepancy.

Rapid and Green Production of Mo2C Nanoparticles with High Photo‐Thermalization via Single‐Step Femtosecond‐Laser Irradiation

Photothermal cancer therapy demands nanomaterials with specific traits, including selective absorption of biotransparent near‐infrared (NIR) light, efficient light‐to‐heat conversion, biocompatibility, dispersibility, and prolonged temporal stability. These desirable properties are achieved by synthesizing Mo2C nanoparticles via an environmentally friendly femtosecond‐laser ablation method. Mo2C flakes are dispersed in water and treated with different laser powers for different durations. This process produces Mo2C nanoparticles in a single step in 10 min with water as the only additional material, forming stable colloidal solutions with no contaminants or hazardous waste. Structural and compositional characterization indicates laser‐induced amorphization of the nanoparticles, including gradual oxidation that enhances NIR light absorption. Notably, the Mo2C nanoparticle solution prepared using a 1.6‐W laser power in 10 min demonstrates photothermal conversion efficiencies exceeding 45% and 50% and temperature increases of 21 and 22 °C when illuminated with biotransparent 800 and 1064 nm NIR light, respectively. Furthermore, the solution exhibits exceptionally stable photothermal behavior over 6 months. These Mo2C nanoparticles, prepared by a rapid and clean laser manufacturing method, hold great promise for advancing photothermal therapy to combat cancer noninvasively.

Hypoeutectic Liquid Metal Printing of 2D Indium Gallium Oxide Transistors.

2D native surface oxides formed on low melting temperature metals such as indium and gallium offer unique opportunities for fabricating high-performance flexible electronics and optoelectronics based on a new class of liquid metal printing (LMP). An inherent property of these Cabrera-Mott 2D oxides is their suboxide nature (e.g., In2O3-x), which leads high mobility LMP semiconductors to exhibit high electron concentrations (ne >1019cm-3) limiting electrostatic control. Binary alloying of the molten precursor can produce doped, ternary metal oxides such as In-X-O with enhanced electronic performance and greater bias-stress stability, though this approach demands a deeper understanding of the native oxides of alloys. This work presents an approach for hypoeutectic rapid LMP of crystalline InGaOx (IGO) at ultralow process temperatures (180°C) beyond the state of the art to fabricate transistors with 10X steeper subthreshold slope and high mobility (≈18cm2Vs-1). Detailed characterization of IGO crystallinity, composition, and morphology, as well as measurements of its electronic density of states (DOS), show the impact of Ga-doping and reveal the limits of doping induced amorphization from hypoeutectic precursors. The ultralow process temperatures and compatibility with high-k Al2O3 dielectrics shown here indicate potential for 2D IGO to drive low-power flexible transparent electronics.

Bacterial communities on giant kelp in the Magellan Strait: Geographical and intra-thallus patterns.

The giant kelp Macrocystis pyrifera is categorized as a keystone species, forming highly productive forests that provide ecosystem services and host a remarkable marine biodiversity of macro and microorganisms. The association of microorganisms with the algae is close and can be functionally interdependent. The Magellan Strait, a natural marine passage between the Atlantic and Pacific oceans, harbours extensive giant kelp forests. However, information related to the diversity of bacterial communities in this region is still scarce. In this study, 16S rRNA gene metabarcoding was used to characterize the diversity and composition of bacterial communities associated with apical blades and sporophylls of M. pyrifera from different sites (Bahía Buzo, San Gregorio, and Buque Quemado). Additionally, data from satellites and reanalysis, as well as tide data, were used to characterize the environmental variability. The findings revealed discernible local variations in bacterial taxa across sampling sites, with consistent dominance of Proteobacteria, Verrucomicrobia, Bacteroidetes, and Planctomycetes. Furthermore, a distinctive bacterial community structure was identified between apical and sporophyll blades of M. pyrifera. This research marks the inaugural characterization of bacterial community diversity and composition associated with M. pyrifera in the remote and understudied sub-Antarctic region of the Magellan Strait.

Characterization of Phytoplankton Composition in Lake Maggiore: Integrated Chemotaxonomy for Enhanced Cyanobacteria Detection.

Cyanobacterial blooms in lakes have increased in frequency and intensity over the past two decades, negatively affecting ecological and biogeochemical processes. This study focuses on the phytoplankton composition of Lake Maggiore, with a special emphasis on cyanobacteria detection through pigment composition. While microscopy is the standard method for phytoplankton identification, pigment-based methods provide broader spatiotemporal coverage. Between May and September 2023, five measurement campaigns were conducted in Lake Maggiore, collecting bio-geochemical and bio-optical data at 27 stations. The total Chlorophyll-a (TChl a) was measured, with concentrations ranging from 1.13 to 6.9 mg/m3. Phytoplankton pigment composition was analyzed using High-Performance Liquid Chromatography (HPLC) and the CHEMTAX approach was applied for phytoplankton classification. The results were cross-validated using Principal Component Analysis (PCA), Hierarchical Cluster Analysis (HCA), and microscopic counts. Cyanobacteria were identified based on unique pigment markers, such as carotenoids. The HPLC-derived pigment classification results aligned well with both PCA and HCA and microscopic counts verified the accuracy of the pigment-based chemotaxonomy. The study demonstrates that pigment-based classification methods, when combined with statistical analyses, offer a reliable alternative for identifying cyanobacteria and other phytoplankton groups, with potential applications in support of remote sensing algorithm development.

Microstructural and Oxidation Effects of Nb Additions to U3Si2

U3Si2 is a long term, accident-tolerant nuclear fuel candidate for light-water reactors because of its superior thermal conductivity and increased uranium density when compared to traditional uranium dioxide (UO2). While reducing internal thermal stresses and increasing efficiency, U3Si2 exhibits energetic oxidation during certain off-normal and accident scenarios, which include coolant or steam exposure. To mitigate this, Nb is investigated as an alloy constituent to enhance corrosion resistance and increase mechanical strength. The work presented investigates the response of Nb-alloyed U3Si2 to steam atmospheres. A thermogravimetric analysis is conducted in flowing steam to T &gt; 1000 °C to assess oxidation resistance. The phase characterization of as-melted, thermally annealed and post-oxidation compositions with up to 12 vol% Nb by powder X-ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy is reported.