Search

This study investigated the influence of carbon source on the microstructure and water–oxygen corrosion behavior of Si–Y alloy modified SiC/SiC composites. The results indicated that incorporating a small-sized and diffusely distributed carbon source within the matrix not only facilitates the preparation of a highly dense matrix, but also enables a uniform dispersion of the reaction-generated SiC. Furthermore, with the assistance of residual Si–Y alloy, the dispersed SiC enhanced the matrix strength, leading to a stepwise fracture behavior of the composites. Yttrium silicate with a gradient structure formed around the dispersed SiC could effectively exert its water–oxygen corrosion resistance. After 100 h of water–oxygen corrosion test at 1300 °C, the flexural strength of the composites with this structure reached 416 MPa, with a retention rate of 85 %. Both bending strength and retention were found to be at a high level in the current research on matrix modification. [ABSTRACT FROM AUTHOR]

Both real and synthetic materials are regularly used by providers of external quality assessment and proficiency testing schemes, and there are, in most cases, justifiable reasons for the choice made. This article focusses on the field of clinical biochemistry and discusses the different properties of a material and the benefits and limitations of using real or synthetic material. However, the overarching principles should be able to be applied to all sectors within the laboratory. Whilst genuine/real material would appear to be the preferred matrix, this is not always practicable, and synthetic material may be a suitable alternative. Synthetic material covers a wide range of material, be it that the material is 100% artificial to real material being used as a 'base' item, which is manipulated either by the addition of further real material from a different source or by the addition of exogenous analyte. A number of real-life cases are presented to demonstrate the impact of material matrix, storage conditions, volume, and interferences. [ABSTRACT FROM AUTHOR]

The security requirements of new applications such as cloud computing, big data, and the Internet of Things have promoted the development and application of security protocols such as secure multi-party computation, fully homomorphic encryption, and zero-knowledge proof. In order to meet these demands, there is a need for new symmetric ciphers that minimize multiplications in F 2 n or F p , where p is prime. One construction that addresses this demand is Partial SPN (P-SPN) construction, where the S-box layer is only applied to a portion of the state in each round. And there have been several research on the construction over the past years. The key to the design of P-SPN construction lies in the linear layers, but systematic exploration in this direction has been lacking in the existing work. In this work, we first establish a lower bound on the dimension of the maximal invariant subspace without active S-boxes for a generic P-SPN scheme. Subsequently, we concentrate on the linear layers of P-SPN construction. Through a meticulous examination of intriguing and beneficial characteristics for various matrices, we showcase that the security of a P-SPN scheme against invariant subspace attack depends on the degree of the minimal polynomial of the matrix. Inadequate choices of the matrices allow for large invariant subspaces that navigate any number of rounds without activating any S-boxes. A comprehensive proof for the Conjecture 1 proposed by Keller and Rosemarin is presented, which not only further improves the lower bound on the dimension of the maximal invariant subspace for the P-SPN rounds of STARKAD permutation, but also implies a lower bound on the dimension of the maximal invariant subspace for block matrices with special blocks. For a block circulant matrix with special blocks, a better annihilating polynomial exists and a lower bound on the dimension of the maximal invariant subspace can be identified. For circulant matrices and block circulant matrices with circulant blocks, we introduce methods to ascertain the range or exact value of the minimal polynomial degree. This determination advances the exploration of the invariant subspaces in these matrices. Especially if the number of S-Boxes in a P-SPN scheme is 1, we can attain the exact value of the dimension for the maximal invariant subspace. All the cases discussed here are invariant subspaces with inactive S-boxes. Our work intends to provide concise cryptanalytic methods for new proposals following P-SPN or HADES design principles. In addition, we derive a way to make sure that a circulant matrix C is resistant to invariant subspace attack with inactive S-boxes, thus providing design criteria for the construction of such matrices in the design of P-SPN schemes. [ABSTRACT FROM AUTHOR]

Bioassembly encompasses various techniques such as bioprinting, microfluidics, organoids, and self-assembly, enabling advances in tissue engineering and regenerative medicine. Advancements in bioassembly technologies have enabled the precise arrangement and integration of various cell types to more closely mimic the complexity functionality of the neurovascular unit (NVU) and that of other biodiverse multicellular tissue structures. In this context, bioprinting offers the ability to deposit cells in a spatially controlled manner, facilitating the construction of interconnected networks. Scaffold-based assembly strategies provide structural support and guidance cues for cell growth, enabling the formation of complex bio-constructs. Self-assembly approaches utilize the inherent properties of cells to drive the spontaneous organization and interaction of neuronal and vascular components. However, recreating the intricate microarchitecture and functional characteristics of a tissue/organ poses additional challenges. Advancements in bioassembly techniques and materials hold great promise for addressing these challenges. The further refinement of bioprinting technologies, such as improved resolution and the incorporation of multiple cell types, can enhance the accuracy and complexity of the biological constructs; however, developing bioinks that support the growth of cells, viability, and functionality while maintaining compatibility with the bioassembly process remains an unmet need in the field, and further advancements in the design of bioactive and biodegradable scaffolds will aid in controlling cell adhesion, differentiation, and vascularization within the engineered tissue. Additionally, integrating advanced imaging and analytical techniques can provide real-time monitoring and characterization of bioassembly, aiding in quality control and optimization. While challenges remain, ongoing research and technological advancements propel the field forward, paving the way for transformative developments in neurovascular research and tissue engineering. This work provides an overview of the advancements, challenges, and future perspectives in bioassembly for fabricating neurovascular constructs with an add-on focus on bioprinting technologies. [ABSTRACT FROM AUTHOR]

Chondritic components such as chondrules and matrix are the key time capsules that can help us understand the evolution and dynamics of the protoplanetary disk from which the Solar System originated. Knowledge of where and how these components formed and to what extent they were transported in the gaseous disk provides major constraints to astrophysical models that investigate planet formation. Here, we explore whether chondrules and matrix are genetically related to each other and formed from single reservoirs per chondrite group or if every chondrite represents a unique proportion of components transported from a small number of formation reservoirs in the disk. These 'static versus dynamic disk' interpretations of cosmochemical data have profound implications for the accretion history of the planets in the Solar System. To fully understand the relationship between chondrules and matrix and their potential "complementarity", we dive into the petrological nature and origin of matrix, the chemical and isotopic compositions of chondrules and matrix and evaluate these data considering the effect of secondary alteration observed in chondrites and the potential complexity of chondrule formation. Even though we, the authors, have used different datasets and arrived at differing interpretations of chondrule-matrix relationships in the past, this review provides clarity on the existing data and has given us new directions towards future research that can resolve the complementarity debate. [ABSTRACT FROM AUTHOR]

In this study, in order to determine the effect of matrices' shape on the percolation threshold values, computer simulations were performed using the Monte Carlo method for a 200 × 200 square-shaped matrix and rectangular matrices containing the same number of nodes as the square matrix. Based on the simulations, the average values of the percolation thresholds and standard deviations for the current flow along and across the matrices were determined. It was determined that for a square-shaped matrix, the average values of the percolation thresholds in both directions of the current flow were the same. Extending the rectangular matrix while reducing its height causes the average value of the percolation threshold in the direction of the current flow along the matrix to increase from 0.592740 to 0.759847, while in the transverse direction, it decreases from 0.592664 to 0.403614. The values of the classical asymmetry coefficients of the probability distributions of the percolation thresholds for both directions of the current flow were determined. Histograms of the probability distributions of the percolation threshold values for a square-shaped matrix and rectangular matrices were made and compared with the normal distributions. It was found that the occurrence of two percolation thresholds in rectangular layers should be considered when analyzing the electrical conductivity measurements of nanocomposite thin films. [ABSTRACT FROM AUTHOR]

The extracellular matrix (ECM) provides an integrated 3D environment for living cells to communicate and display collective behaviors. In bottom‐up synthetic biology, several new types of synthetic prototissues (assemblies of synthetic protocells) are developed to mimic various aspects of cellular signaling. However, the spatiotemporal interplay between supporting matrix and protocells, which is critical for mimicking macroscopic responsiveness of multicellular organisms, has remained challenging to control. Herein, a modular strategy is reported to construct macroscopic prototissues with complex structures based on hierarchical assembly of matrix and polymeric protocells prepared by using CaCO3 sacrificial microparticle templates. Mechanical coordination between protocells and matrix allows for the transformation in response to both the presence and history of multiple stimuli. Taking advantage of the multi‐responsiveness, it further demonstrated an artificial form of metabolic behaviors where a digestive prototissue prey on a substrate‐containing prototissue by two‐way communication. Overall, the methodology presents a strategy to achieve mechanical and chemical communication in matrix containing, tissue‐like materials harboring the potential to reconstitute collective behaviors for bottom‐up synthetic biology and bioinspired engineering. [ABSTRACT FROM AUTHOR]

This perspective article primarily discusses the role of water matrix for the advanced treatment of watercourses. This relies on experimental work regarding the inactivation of Escherichia coli, Enterococcus faecalis, and Vibrio parahaemolyticus by an advanced oxidation process, namely activated persulfate, in five matrices of varying complexity, (i.e., from as simple as deionized water to secondary treated effluent). For comparison purposes, respective tests were performed with ultraviolet (UVC) radiation, a conventional disinfection process, while results from recent literature are also discussed. Only in deionized water can activated persulfate (i.e., 150 mg L−1 sodium persulfate and 30 mg L−1 ferrous ions) completely inactivate all three bacteria in the course of several minutes, but the process is ineffective in other matrices (i.e., bottled, tap, or lake water, as well as wastewater), where 1–2 orders of magnitude longer times are needed for partial inactivation, which decreases in the order E. coli > E. faecalis ~ V. parahaemolyticus. Conversely, UVC (at 30 W nominal value) is highly efficient against all bacteria and in all matrices in a matter of just a few seconds. The general perception is that treatment efficiency decreases with increasing matrix complexity in terms of total concentration and/or individual components composition, irrespective of the applied treatment method and its objectives (i.e., disinfection, decontamination, or mineralization). However, there are always exceptions the rule, further highlighting how case‐specific advanced water treatment can be. The matrix itself should be given particular emphasis for the rational design of efficient water treatment processes. © 2023 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Poor vacuum stability limits the application of many matrices in matrix‐assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) that requires long‐term measurement duration in high vacuum. In this study, a new approach using conjugate polymer anchor to protect unstable matrix from volatilizing in MALDI source based on ion bond is provided. Unlike strong covalent bonds which often introduce unnecessary groups, the weaker ion bonds are more conducive to breaking under laser radiation while effectively preventing matrix volatilization in a vacuum environment. The results confirm that conjugate polymer anchor will neither introduce additional ion peaks nor affect signal intensity, yet maintains comparable quantification properties. Vacuum stability of three kinds of typical matrices is enhanced using polymer anchors, and the in situ MALDI MS imaging of mouse brain and liver cancer is improved significantly. [ABSTRACT FROM AUTHOR]

While the number of publications on wine and health is steadily increasing, ranging from a molecular level to epidemiological studies, often with contradictory results, little attention has been given to a holistic approach to research, starting from the molecular level to arrive at pharmacological and medical conclusions. In this review, some unusual concepts are considered, such as the phytocomplex, the vehicle, and the Matrix effect. The concept of the phytocomplex is discussed, specifically the biological activities of Tyrosol, Hydroxytyrosol, and Resveratrol; indeed, the interactions among different molecules in herbal matrices provide a specific response. This is often markedly different from the response evoked by single constituents in the modulation of microbial populations in the gut, in intestinal stability and bioaccessibility, and, obviously, in inducing biological responses. Among the many alcoholic beverages which contain these molecules, wine has the most peculiar Matrix effect, which can heavily influence the bioavailability of the phytocomplex obtained by the fermentation processes that produce this beverage. Wine's Matrix effect plays an instrumental role in improving the beneficial compounds' bioavailability and/or in inhibiting alcohol metabolites' carcinogenicity. Underestimation of the wine Matrix effect could lead to deceiving results, as in the case of dealcoholized wine or wine-compound-based nutritional supplements; alternatively, this can occur in the emphasis of a single component's toxic activity, in this case, alcohol, ignoring the specific molecular-level protective action of other compounds (polyphenols) that are present in the same matrix. The dark side of the Matrix effect is also discussed. This review confirms the research recommendations made by the WHO Scientific Group, which suggests it is important "to investigate the possible protective effects of ingredients other than alcohol in alcoholic beverages", considering that most recent studies seem not only relevant but also capable of directing future research towards innovative points of view that have so far been too neglected. [ABSTRACT FROM AUTHOR]

AbstractNanodiamonds have been researched as sphere-shaped carbon nano-entities having countless surface/structural properties, facile fabrication and mammoth technological value. An important utilization of nanodiamonds has been observed as nano-reinforcing agents for nanocompositing purposes. Semiconducting polymers (conjugated polymers) having π electron delocalization have been documented for worthy electrochemical/optical/thermal/mechanical features, in addition to the electron transfer through their backbone. Doping of carbonaceous nanoparticles, like nanodiamonds, with conjugated polymers have been found to further improve the valuable physical characteristics in their final nanocomposite form. Correspondingly, this overview describes the impact of nanodiamond nano-reinforcement on the specialized aspects of polyaniline/nanodiamond, polypyrrole/nanodiamond and polythiophene/nanodiamond nanocomposites. According to literature reports, these groupings of conjugated polymer/nanodiamond hybrids revealed noteworthy microstructural, conductive, optical, electrochemical, microwave absorption, specific capacitance, photovoltaic and actuation characteristics. Subsequently, several significant applications of polymer/nanodiamond nanomaterials have been explored including the solar cells, supercapacitors and actuators. [ABSTRACT FROM AUTHOR]

The insula is an integral component of sensory, motor, limbic, and executive functions, and insular dysfunction is associated with numerous human neuropsychiatric disorders. Insular efferents project widely, but insulo-striate projections are especially numerous. The targets of these insulo-striate projections are organized into tissue compartments, the striosome and matrix. These striatal compartments have distinct embryologic origins, afferent and efferent connectivity, dopamine pharmacology, and susceptibility to injury. Striosome and matrix appear to occupy separate sets of cortico-striato-thalamo-cortical loops, so a bias in insulo-striate projections toward one compartment may also embed an insular subregion in distinct regulatory and functional networks. Compartment-specific mapping of insulo-striate structural connectivity is sparse; the insular subregions are largely unmapped for compartment-specific projections. In 100 healthy adults, diffusion tractography was utilized to map and quantify structural connectivity between 19 structurally-defined insular subregions and each striatal compartment. Insulo-striate streamlines that reached striosome-like and matrix-like voxels were concentrated in distinct insular zones (striosome: rostro- and caudoventral; matrix: caudodorsal) and followed different paths to reach the striatum. Though tractography was generated independently in each hemisphere, the spatial distribution and relative bias of striosome-like and matrix-like streamlines were highly similar in the left and right insula. 16 insular subregions were significantly biased toward 1 compartment: 7 toward striosome-like voxels and 9 toward matrix-like voxels. Striosome-favoring bundles had significantly higher streamline density, especially from rostroventral insular subregions. The biases in insulo-striate structural connectivity that were identified mirrored the compartment-specific biases identified in prior studies that utilized injected tract tracers, cytoarchitecture, or functional MRI. Segregating insulo-striate structural connectivity through either striosome or matrix may be an anatomic substrate for functional specialization among the insular subregions. [ABSTRACT FROM AUTHOR]

Arthropod movement has been noticeably understudied compared to vertebrates. A crucial knowledge gap pertains to the factors influencing arthropod movement at habitat boundaries, which has direct implications for population dynamics and gene flow. While larger arthropod species generally achieve greater dispersal distances and large‐scale movements are affected by weather conditions, the applicability of these relationships at a local scale remains uncertain. Existing studies on this subject are not only scarce but often limited to a few species or laboratory conditions.To address this knowledge gap, we conducted a field study in two nature reserves in Belgium, focusing on both flying and cursorial (non‐flying) arthropods. Over 200 different arthropod species were captured and released within a circular setup placed in a resource‐poor environment, allowing quantification of movement speed and direction. By analysing the relationship between these movement variables and morphological (body size) as well as environmental factors (temperature and wind), we aimed to gain insights into the mechanisms driving arthropod movement at natural habitat boundaries.For flying species, movement speed was positively correlated with both body size and tailwind speed. In contrast, movement speed of cursorial individuals was solely positively related with temperature. Notably, movement direction was biased towards the vegetated areas where the arthropods were originally caught, suggesting an internal drive to move towards suitable habitat. This tendency was particularly strong in larger flying individuals and under tailwind conditions. Furthermore, both flying and cursorial taxa were hindered from moving towards the habitat by strong upwind.In conclusion, movement speed and direction at patch boundaries are dependent on body size and prevailing weather conditions, and reflect an active decision‐making process. [ABSTRACT FROM AUTHOR]

Summary: Phytohormones possess unique chemical structures, and their physiological effects are regulated through intricate interactions or crosstalk among multiple phytohormones. MALDI‐MSI enables the simultaneous detection and imaging of multiple hormones. However, its application for tracing phytohormones is currently restricted by low abundance of hormone in plant and suboptimal matrix selection.2,4‐Dihydroxy‐5‐nitrobenzoic acid (DHNBA) was reported as a new MALDI matrix for the enhanced detection and imaging of multiple phytohormones in plant tissues. DHNBA demonstrates remarkable sensitivity improvement when compared to the commonly used matrix, 2,5‐dihydroxybenzoic acid (DHB), in the detection of isoprenoid cytokinins (trans‐zeatin (tZ), dihy‐drozeatin (DHZ), meta‐topolin (mT), and N6‐(Δ2‐isopentenyl) adenine (iP)), jasmonic acid (JA), abscisic acid (ABA), and 1‐aminocyclo‐propane‐1‐carboxylic acid (ACC) standards.The distinctive properties of DHNBA (i.e. robust UV absorption, uniform matrix deposition, negligible background interference, and high ionization efficiency of phytohormones) make it as an ideal matrix for enhanced detection and imaging of phytohormones, including tZ, DHZ, ABA, indole‐3‐acetic acid (IAA), and ACC, by MALDI‐MSI in various plant tissues, for example germinating seeds, primary/lateral roots, and nodules.Employing DHNBA significantly enhances our capability to concurrently track complex phytohormone biosynthesis pathways while providing precise differentiation of the specific roles played by individual phytohormones within the same category. This will propel forward the comprehensive exploration of phytohormonal functions in plant science. [ABSTRACT FROM AUTHOR]

For a nilpotent group G without π -torsion, and x , y ∈ G , if x n = y n for a π -number n , then x = y ; if x m y n = y n x m for π -numbers m , n , then x y = y x. This is a well-known result in group theory. In this paper, we prove two analogous theorems on matrices, which have independence significance. Specifically, let m be a given positive integer and A a complex square matrix satisfying that (i) all eigenvalues of A are nonnegative, and (ii) rank ⁡ A 2 = rank ⁡ A ; then A has a unique m -th root X with rank ⁡ X 2 = rank ⁡ X , all eigenvalues of X are nonnegative, and moreover there is a polynomial f (λ) with X = f (A). In addition, let A and B be complex n × n matrices with all eigenvalues nonnegative, and rank ⁡ A 2 = rank ⁡ A , rank ⁡ B 2 = rank ⁡ B ; then (i) A = B when A r = B r for some positive integer r , and (ii) A B = B A when A s B t = B t A s for two positive integers s and t. [ABSTRACT FROM AUTHOR]

Background. Bacterial films are a marker of chronic recurrent infections. Biofilms on mucous membranes block the inflammatory response of the macroorganism, suppressing the activity of immunocytes, and thereby allow microorganisms to reach high concentrations. Currently, research is being conducted to find medications that can act on biofilms. Enzymes, especially their complexes, are substances that can destroy bacterial films. Objective. Еo determine in vitro the sensitivity of bacterial biofilms formed by vaginal microorganisms to the complex of enzymes included in Wobenzym. Materials and methods. The study included 72 clinical isolates of pure microorganism cultures isolated from the vaginal biotope: Gardnerella vaginalis (3), Enterococcus faecalis (9), Escherichia coli (18), Klebsiella pneumoniae (15), Klebsiella aerogenes (3), Lactobacillus crispatus (3), Streptococcus pyogenes (3), Acinetobacter baumanii (3), Staphylococcus aureus (3), Candida albicans (3), Enterococcus faecium (3), Streptococcus agalactiae (3), Lactobacillus acidophilus (3). Bacterial biofilm formation was determined in polystyrene flat-bottom plates using a modified method of Christensen et al. (1985). The tablet form of Wobenzym was used in the study. The tablet shell was washed with saline, the tablet itself was dissolved in 10 ml of 0.9% NaCl and used for in vitro studies. The result was determined using a reader on a spectrophotometer to determine the optical density (OD) of the formed biofilm. It was believed that the drug acted on the bacterial film, reducing the OD by more than three times. Results. An in vitro study revealed clinical isolates of bacteria that formed biofilms of varying severity. Of the 72 clinical bacterial isolates, 38 formed biofilms. A pronounced effect of the complex of enzymes included in Wobenzym on biofilms formed by microorganisms such as A. baumanii, S. aureus, G. vaginalis and E. faecalis was noted. Conclusion. Wobenzym has an effective destructive effect on biofilms formed by various microorganisms, including G. vaginalis, common causative agents of bacterial vaginosis, as well as staphylococci and enterococci, causative agents of aerobic (nonspecific) vaginitis. Conclusion. The drug Wobenzym has an effective destructive effect on biofilms formed by various microorganisms, including Gardnerella vaginalis, common causative agents of bacterial vaginosis, as well as staphylococci and enterococci, causative agents of aerobic (nonspecific vaginitis).

SiCf/SiC composites have emerged as one of the most promising materials for aero‐engine hot‐end structures. However, their performance is limited by their susceptibility to oxidation and corrosion reactions with oxygen and water vapor. To overcome this challenge, antioxidant‐modified phases are introduced into matrices of SiCf/SiC composites which improve their water and oxygen resistance. In this study, the resistance of SiCf/SiC composites modified by yttrium silicate matrix (SiCf/SiC‐YS composites) to air at 1000–1400°C and water‐oxygen environments at 1200°C was investigated. The diffusion paths of oxygen in SiCf/SiC‐YS composites and the antioxidant behavior of the yttrium silicate matrix were discussed. Additionally, the differences in oxygen and water‐oxygen corrosion resistance of SiCf/SiC‐YS composites at the same temperature were compared. The strength retention of SiCf/SiC‐YS composites after oxidation and water‐oxygen corrosion at 1200°C were 138.6% and 108.8%, respectively. This indicates that the addition of water vapor accelerated the degradation of SiCf/SiC‐YS composites. By comparing with SiCf/SiC composites, it can be concluded that the modification of the yttrium silicate matrix considerably improved the oxidation resistance of SiCf/SiC composites. [ABSTRACT FROM AUTHOR]

Let M 1 , 2 (F) be the algebra of 3 × 3 matrices with orthosymplectic superinvolution ⁎ over a field F of characteristic zero. We study the ⁎-identities of this algebra through the representation theory of the group H n = (Z 2 × Z 2) ∼ S n. We decompose the space of multilinear ⁎-identities of degree n into the sum of irreducibles under the H n -action in order to study the irreducible characters appearing in this decomposition with non-zero multiplicity. Moreover, by using the representation theory of the general linear group, we determine all the ⁎-polynomial identities of M 1 , 2 (F) up to degree 3. [ABSTRACT FROM AUTHOR]

We consider the tensor products of square matrices of different sizes and introduce the stretching maps, which can be viewed as a generalized matricization. Stretching maps conserve algebraic properties of the tensor product, but are not necessarily injective. Dropping the injectivity condition allows us to construct examples of stretching maps with additional symmetry properties. Furthermore, this leads to the averaging of the tensor product and possibly could be used to compress the data.

The use of natural rice straw as a filler for composite materials has not been optimally utilized; only around 7–16% of the grain is used in the industry. Various developments have been carried out, including its use as a filler or reinforcement for wood polymer composite products, but it is not effective because of poor interfacial adhesion. An alternative to increase the effectiveness of straw fibers in wood composites is by using cold plasma (atmospheric) treatment. In this research, composites consisting of straw fiber and biodegradable polyvinyl alcohol (PVA) matrix were made with and without cold plasma injection treatment. PVA is used because of its hydrophilic nature and function as a matrix. This research aims to determine the effect of cold plasma injection on straw fiber/PVA composites. The method used consists of preparation of straw fiber and composites, flexural testing with time variations of 10, 20, and 30 sec, morphological analysis using SEM to determine surface roughness, and FTIR test. The results showed that treatment with and without plasma provided significant differences in roughness. Plasma causes roughness to increase, thereby increasing the adhesion of the interface to the matrix.

In this paper we study multiplicative semigroups of $2\times 2$ matrices over a linearly ordered abelian group with an externally added bottom element. The multiplication of such a semigroup is defined by replacing addition and multiplication by join and addition in the usual formula defining matrix multiplication. We show that there are four types of idempotents in this semigroup and we determine which of them are $0$-primitive. We also prove that the poset of idempotents with respect to the natural order is a lattice. It turns out that this matrix semigroup is inverse or orthodox if and only if the abelian group is trivial.

With the encroachment of urban areas into peri-urban landscapes, the requirement for effective green infrastruc ture (GI) planning has become increasingly important for maintaining ecological integrity and human wellbeing. An expert-based matrix approach is proposed as a method for evaluating the potential of cultural ecosystem services (CES) in making informed GI planning decisions in a peri-urban landscape. Experts from various disciplines and areas of work were consulted to systematically evaluate various types of land-use and land-cover classes, as well as protection regimes characteristic of a peri-urban landscape across the CES categories. In addition to CES provision potential, experts also evaluated the possible potential to cause cultural ecosystem disservices. These scores are aggregated to generate spatially explicit maps that highlight areas with high CES provision potential and those with the potential to cause disservices. This approach was then applied to three case study areas, demonstrating its effectiveness in identifying priority areas for GI planning and management interventions. The results highlight the importance of integrating CES considerations into GI planning processes to enhance landscape resilience, social wellbeing, and cultural heritage preservation in dynamic peri-urban environments. Using scoring, validation exercises, and spatially explicit presentation on case studies, the utility and applicability of the expert-based matrix approach as a valuable tool for sustainable GI planning on a landscape scale is demonstrated.

In fiber reinforced composite materials, the interfacial strength between the fibers and the matrix plays a key role in controlling the stress transfer and damage mechanisms of the composite. In this study, CO2 laser surface treatment of the fibers was investigated as a potential sustainable substitute for conventional chemical treatments, that can be costly and have negative environmental effects. The influence of the laser treatment on basalt fiber fabric was comprehensively investigated. The fibers were subjected to different laser power levels and characterized from a morphological and mechanical point of view. From optical and scanning electron microscopy, it was observed that the treated fibers manifested increased surface roughness along with spots of fused and bonded fibers. Individual treated fibers exhibited improved tensile properties with increased values of scale parameter (by about 21%) in the case of a laser power equal to 1.04 W/mm2, and no substantial changes in Young's modulus. The treated fibers were subsequently used in the preparation of epoxy‐based microcomposites, and microdebonding tests revealed an increase in the interfacial shear strength (IFSS) up to 8%. Therefore, this work proved that a laser surface treatment of basalt fibers is a valid alternative to conventional fiber surface modification to enhance the mechanical compatibility between fibers and matrix, and therefore to improve the mechanical performances of basalt fiber composites. Highlights: Failure in composites due to weak interfacial adhesion with epoxy.CO2 laser treatment of basalt fibers to enhance interfacial adhesion.Treated fibers exhibit improved tensile properties.Treated fibers manifested improved interfacial shear strength (IFSS, +8%). [ABSTRACT FROM AUTHOR]

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

SRAM memory systems are suffering from an increase in data due to the aggressive CMOS integration density. The frequency of Multiple Cell Upsets (MCUs) on SRAM memory is increasing, which is resulting in the increasing use of ECCs.Speed is slowed down by ECCs due to their overhead, both in memory bits and decoding times. In this research, Continuous Adjacent Multiple Bit Upset Correction (CAMBUC)has been proposed to greatly reduce the redundancy and improve correction coverage.In addition, the Interleaved Counter Matrix Code (ICMC) is proposed to simplify the Encoder and decoder circuits which reduces the delay. The proposed method predicts MBU before decoding and maximum parallel 8 error bits are corrected using the proposed method. Using this method, the error correction code's parity check matrix is automatically and effectively constructed, simply stating its error detection and/or correction capabilities. Combinatorial counting operations introduce error detection and error prediction. The proposed ICMC makes use of the decimal and hamming algorithms to achieve the highest level of error detection. In comparison to the conventional decoder, which can rectify double and 8-adjacent errors, the assessment results utilizing the proposed CAMBUC approach demonstrate significant reductions in area, power, and delay. The obtained findings demonstrate that the proposed method has a comparatively long mean time to failure (MTTF) when compared to existing approaches. At the same time, the suggested scheme's delay overhead is, respectively, 20.5%, 14.6%, 11.2%, 8.5%, and 3.5% less than that of the existing Hamming, CMC, ECC for 5-bit adjacent error, eMRSC, and DICE-7-bit ECCmethods. [ABSTRACT FROM AUTHOR]

Given a set X of n x n matrices and a positive integer m, we consider the problem of estimating the cardinalities of the product sets A1 … Am, where Ai ∈ X. When X = Mn(ℤ; H), the set of n x n matrices with integer elements of size at most H, we give several bounds on the cardinalities of the product sets and solution sets of related equations such as A1 … Am = C and A1 … Am = B1 … Bm. We also consider the case where X is the subset of matrices in Mn(픽), where 픽 is a field with bounded rank k ≤ n. In this case, we completely classify the related product set. [ABSTRACT FROM AUTHOR]

One of the components of the fuel composition of dispersion nuclear fuel is a non-fissile material (matrix), which ensures its high radiation resistance. Despite the fact that dispersion nuclear fuel is used in reactors of various purposes (research, power, nuclear power plants, etc.), the operating conditions of which vary significantly, there are a number of requirements that must be taken into account when choosing the matrix material. Metals (aluminum and zirconium, as well as their alloys) have found wide application as matrix material in the production of dispersion-type fuel elements for research reactors and reactors of naval nuclear power plants (NPPs). Stainless steel matrix is used in dispersion nuclear fuel in power reactor plants. [ABSTRACT FROM AUTHOR]

In Caenorhabditis elegans , expanded families of divergent Hedgehog-related and patched-related proteins promote numerous processes ranging from epithelial and sense organ development to pathogen responses to cuticle shedding during the molt cycle. The molecular functions of these proteins have been mysterious since nematodes lack a canonical Hedgehog signaling pathway. Here we show that Hedgehog-related proteins are components of the cuticle and precuticle apical extracellular matrices that coat, shape, and protect external epithelia. Of four Hedgehog-related proteins imaged, two (GRL-2 and GRL-18) stably associated with the cuticles of specific tubes and two (GRL-7 and WRT-10) labeled precuticle substructures such as furrows or alae. We found that wrt-10 mutations disrupt cuticle alae ridges, consistent with a structural role in matrix organization. We hypothesize that most nematode Hedgehog-related proteins are apical extracellular matrix components, a model that could explain many of the reported functions for this family. These results highlight ancient connections between Hedgehog proteins and the extracellular matrix and suggest that any signaling roles of C. elegans Hedgehog-related proteins will be intimately related to their matrix association. [ABSTRACT FROM AUTHOR]

In this paper, enhancing the tribological characteristics of novel cast metallic materials—hybrid multi-component cast irons—by applying a strengthening heat treatment is described. The experimental materials were the cast alloys of a nominal composition (5 wt.% W, 5 wt.% Mo, 5 wt.% V, 10 wt.% Cr, 2.5 wt.% Ti, Fe is a balance) supplemented with 0.3–1.1 wt.% C and 1.5–2.5 wt.% B (total of nine alloys). The heat treatment was oil-quenching followed by 200 °C tempering. The quench temperature (QT) varied in the range of 900–1200 °C, with a step of 50 °C (with a 2-h holding at QT). The correlation of the QT with microstructure and properties was estimated using microstructure/worn surface characterization, differential scanning calorimetry, hardness measurement, and three-body-abrasive wear testing (using Al2O3 particles). The as-cast alloys had a multi-phase structure consisting of primary and/or eutectic borocarbide M2(B,C)5, carboborides M(C,B), M7(C,B)3, M3(C,B), and the matrix (ferrite, martensite, pearlite/bainite) in different combinations and volume fractions. Generally, the increase in the quenching temperature resulted in a gradual increase in hardness (maximally to 66–67 HRC) and a decrease in the wear rate in most alloys. This was due to the change in the phase-structure state of the alloys under quenching, namely, the secondary carboboride precipitation, and replacing ferrite and pearlite/bainite with martensite. The wear rate was found to be inversely proportional to bulk hardness. The maximum wear resistance was attributed to QT = 1150–1200 °C, when the wear rate of the alloys was lowered by three to six times as compared to the as-cast state. With the QT increase, the difference in the wear rate of the alloys decreased by three times. The highest abrasive resistance was attributed to the alloys with 1.1 wt.% C, which had a 2.36–3.20 times lower wear rate as compared with that of the reference alloy (13 wt.% Cr cast iron, hardness of 66 HRC). The effects of carbon and boron on hardness and wear behavior are analyzed using the regression models developed according to the factorial design procedure. The wear mechanisms are discussed based on worn surface characterization. [ABSTRACT FROM AUTHOR]

Over Prüfer domains, we characterize idempotent by nilpotent 2-products of 2 × 2 matrices. Nilpotents are always such products. We also provide large classes of rings over which every 2 × 2 idempotent matrix is such a product. Finally, for 2 × 2 matrices over GCD domains, idempotent–nilpotent products which are also nilpotent–idempotent products are characterized. [ABSTRACT FROM AUTHOR]

High-level waste (HLW) separation into fractions simplifies isolation in matrices and disposal. One of these fractions consists of rare earths (REE) and minor actinides (MA = Am, Cm). Among the rare earth elements there are the isotopes 144Ce, 147Pm, 151Sm, and 154,155Eu with half-lives of up to 93 years; decay of the nuclides will cause heating of the matrices with HLW. It has been shown that preliminary storage of the REE–MA matrix for ten years or more will significantly reduce the content of REE radioisotopes and their contribution to temperature increase in the geological repository. [ABSTRACT FROM AUTHOR]

Deuterium to hydrogen isotope ratios in unequilibrated ordinary chondrites (UOCs) which have undergone little-to-no thermal metamorphism pose an interesting problem when looking at water in the early Solar System. Bulk chondrite studies have shown that UOCs of the lowest subtypes have D/H ratios as high as comets from the outer Solar System, which, along with bulk UOC water abundances, decrease with thermal metamorphism. Since bulk UOC analyses represent a complex mixture of organic and hydrated phases, it is not clear what phase(s) is responsible for the high bulk D/H values. In this study, we report in situ secondary ion mass spectrometry (SIMS) measurements of the H isotope composition of the fine-grained matrix of UOCs with petrological subtypes ranging from 3.00 to 3.9. We find that for matrix areas in UOCs of petrologic subtype ≥3.2, correlations between D-rich organic material and D-poor phyllosilicates give relatively D-poor intrinsic water isotopic compositions, with δD values between −320 ± 91 ‰ and −71 ± 71 ‰, which are inherited from parent body accretion. Therefore, we conclude that OC parent bodies accreted D-poor water ice that had an H isotopic composition similar to that of CM and CV chondrite parent bodies. We find that matrix in UOCs of the lowest subtypes (Semarkona, Bishunpur, and Ngawi) show similar water and organic H isotope compositions to higher type UOCs. Our in situ analyses also show that matrix areas in these pristine UOCs contain a third, thus far unidentified, component that carries the high D/H signature, with δD values up to ∼6000 ‰. We propose that this component is pristine amorphous silicates preserved from the molecular cloud or early protoplanetary disc that is extremely sensitive to thermal and aqueous alteration on asteroidal parent bodies. [ABSTRACT FROM AUTHOR]

CI chondrites are the most significant extra-terrestrial samples for estimating the composition of primordial materials in the Solar System. However, CIs lose many primary features because of heavy parent body aqueous alteration. However, CI and CI-related Ryugu particles contain small amounts of relict anhydrous minerals, indicating primary occurrences of chondrules and refractory inclusions. In this study, we estimated the primordial abundance of chondrules in CIs from calculations of the bulk major element compositions. The constraints for the calculation were as follows: 1) CI chondrites primarily comprised chondrules, refractory inclusions, opaque minerals, and a matrix similar to other carbonaceous (C) chondrites. 2) The chemical compositions of these components were similar to those of the unaltered C chondrites. 3) The primary matrix composition of the CI was close to the mean bulk composition. 4) The alteration occurred isochemically. We used the mean major elemental compositions of chondrules and refractory inclusions in an almost unaltered chondrite, Y-81020, CO3.05. Our results were within the range of previously reported CI bulk chemical compositions in the case where chondrule abundances are ≲10 wt%. We also calculated the bulk chemical composition of Tagish Lake, ungrouped C2, which primarily contained ≲20 wt% chondrules. The CI chondrites and Tagish Lake were formed in the outer Solar System. The low primary abundance of chondrules in CIs is closely related to the formation conditions of chondrules in such regions. We suggest that dust with abundant ice and minor chondrules accreted onto the parent bodies of the CI and Tagish Lake in the outer Solar System. Primordial chondrule abundance is the key to clarifying the physical and chemical conditions and evolution of the early Solar System. [ABSTRACT FROM AUTHOR]

Metabolic dysfunction−associated liver disease (MASLD) and steatohepatitis (MASH) are becoming the most common causes of chronic liver disease in the United States and worldwide due to the obesity and diabetes epidemics. It is estimated that by 2030 close to 100 million people might be affected and patients with type 2 diabetes are especially at high risk. Twenty to 30% of patients with MASLD can progress to MASH, which is characterized by steatosis, necroinflammation, hepatocyte ballooning, and in advanced cases, fibrosis progressing to cirrhosis. Clinically, it is recognized that disease progression in diabetic patients is accelerated and the role of various genetic and epigenetic factors, as well as cell–matrix interactions in fibrosis and stromal remodeling, have recently been recognized. While there has been great progress in drug development and clinical trials for MASLD/MASH, the complexity of these pathways highlights the need to improve diagnosis/early detection and develop more successful antifibrotic therapies that not only prevent but reverse fibrosis. [ABSTRACT FROM AUTHOR]

This article provides an overview of the diverse applications of hydrogels in nutrient recovery from water and wastewater. Due to their unique properties, such as high water-retention capacity, nutrient rerelease, and tunable porosity, hydrogels have emerged as promising materials for efficient nutrient capture and recycling. It has been suggested that hydrogels, depending on their composition, can be reused in agriculture, especially in drought-prone areas. Further research paths have been identified that could expand their application in these regions. However, the main focus of the article is to highlight the current gaps in understanding how hydrogels bind nitrogen and phosphorus compounds. The study underscores the need for research that specifically examines how different components of hydrogel matrices interact with each other and with recovered nutrients. Furthermore, it is essential to assess how various nutrient-recovery parameters, such as temperature, pH, and heavy metal content, interact with each other and with specific matrix compositions. This type of research is crucial for enhancing both the recovery efficiency and selectivity of these hydrogels, which are critical for advancing nutrient-recovery technologies and agricultural applications. A comprehensive research approach involves using structured research methodologies and optimization techniques to streamline studies and identify crucial relationships. [ABSTRACT FROM AUTHOR]

Copyright of Nuclear Safety is the property of Nuclear & Radiation Safety Center and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Idiopathic subglottic stenosis (ISGS) is a rare fibrotic disease of the upper trachea with an unknown pathomechanism. It typically affects adult Caucasian female patients, leading to severe airway constrictions caused by progressive scar formation and inflammation with clinical symptoms of dyspnoea, stridor and potential changes to the voice. Endoscopic treatment frequently leads to recurrence, whereas surgical resection and reconstruction provides excellent long-term functional outcome. This study aimed to identify so far unrecognized pathologic aspects of ISGS using single cell RNA sequencing. Our scRNAseq analysis uncovered the cellular composition of the subglottic scar tissue, including the presence of a pathologic, profibrotic fibroblast subtype and the presence of Schwann cells in a profibrotic state. In addition, a pathology associated increase of plasma cells was identified. Using extended bioinformatics analyses, we decoded pathology-associated changes of factors of the extracellular matrix. Our data identified ongoing fibrotic processes in ISGS and provide novel insights on the contribution of fibroblasts, Schwann cells and plasma cells to the pathogenesis of ISGS. This knowledge could impact the development of novel approaches for diagnosis and therapy of ISGS. [ABSTRACT FROM AUTHOR]

We present a survey of the methods aimed at solving matrix linear bilateral equations (and, in particular, Sylvester-type equations) over different domains and at describing the structure of their solutions. Our main attention is focused on the extension and generalization of the results obtained by the authors earlier. On the basis of the standard form of polynomial matrices with respect to semiscalar equivalence, we develop a method aimed at solving Sylvester-type matrix polynomial equations. The structure of these solutions is investigated. We select solutions of bounded degrees and present the conditions for the uniqueness of these solutions. A method for constructing the solutions of Sylvester matrix equations over adequate rings is developed and criteria for the uniqueness of solutions of a certain type are obtained. We also establish the conditions for the existence of solution to the Sylvester-type matrix equation in rings of triangular and block-triangular matrices over the commutative domain of principal ideals. [ABSTRACT FROM AUTHOR]

Autologous platelet-rich plasma (PRP) preparations are prepared at the point of care. Centrifugation cellular density separation sequesters a fresh unit of blood into three main fractions: a platelet-poor plasma (PPP) fraction, a stratum rich in platelets (platelet concentrate), and variable leukocyte bioformulation and erythrocyte fractions. The employment of autologous platelet concentrates facilitates the biological potential to accelerate and support numerous cellular activities that can lead to tissue repair, tissue regeneration, wound healing, and, ultimately, functional and structural repair. Normally, after PRP preparation, the PPP fraction is discarded. One of the less well-known but equally important features of PPP is that particular growth factors (GFs) are not abundantly present in PRP, as they reside outside of the platelet alpha granules. Precisely, insulin-like growth factor-1 (IGF-1) and hepatocyte growth factor (HGF) are mainly present in the PPP fraction. In addition to their roles as angiogenesis activators, these plasma-based GFs are also known to inhibit inflammation and fibrosis, and they promote keratinocyte migration and support tissue repair and wound healing. Additionally, PPP is known for the presence of exosomes and other macrovesicles, exerting cell–cell communication and cell signaling. Newly developed ultrafiltration technologies incorporate PPP processing methods by eliminating, in a fast and efficient manner, plasma water, cytokines, molecules, and plasma proteins with a molecular mass (weight) less than the pore size of the fibers. Consequently, a viable and viscous protein concentrate of functional total proteins, like fibrinogen, albumin, and alpha-2-macroglobulin is created. Consolidating a small volume of high platelet concentrate with a small volume of highly concentrated protein-rich PPP creates a protein-rich, platelet-rich plasma (PR-PRP) biological preparation. After the activation of proteins, mainly fibrinogen, the PR-PRP matrix retains and facilitates interactions between invading resident cells, like macrophages, fibroblast, and mesenchymal stem cells (MSCs), as well as the embedded concentrated PRP cells and molecules. The administered PR-PRP biologic will ultimately undergo fibrinolysis, leading to a sustained release of concentrated cells and molecules that have been retained in the PR-PRP matrix until the matrix is dissolved. We will discuss the unique biological and tissue reparative and regenerative properties of the PR-PRP matrix. [ABSTRACT FROM AUTHOR]

Hydroxyapatite (HAp) is a calcium phosphate ceramic, widely used as a matrix for protein chromatography. The crystal structure of HAp is amenable to a wide range of substitutions, thus allowing for the alteration of its properties. In this study, nickel‐ion substituted HAp (NiSHAp) was synthesized using a wet‐precipitation method, followed by spray drying. This resulted in the structural incorporation of nickel ions within well‐defined microspheres, which were suitable for chromatographic applications. The chromatographic experiments were conducted with NiSHAp and compared with spray‐dried hydroxyapatite (SHAp) matrices. Protein purification experiments were conducted using refolded recombinant L‐asparaginase (L‐Asp), which was produced as inclusion bodies in Escherichia coli. The results showed that NiSHAp effectively adsorbed L‐Asp, which was selectively eluted using a phosphate buffer, surpassing the efficiency of imidazole‐based elution. In contrast, SHAp showed weaker binding and lower selectivity. The significance of this study lies in developing a scalable NiSHAp matrix for protein purification, especially for large‐scale applications. The NiSHAp matrix offers a cost‐effective alternative to commercial immobilized metal affinity chromatography (IMAC) adsorbents, especially for purifying His‐tagged proteins. This innovative approach exhibits the advantages of mixed‐mode chromatography by combining the properties of hydroxyapatite and IMAC in a single matrix, with the potential of improved industrial‐scale protein purification. [ABSTRACT FROM AUTHOR]

All‐inorganic CsPbI3 perovskite is a promising emitter for deep‐red light‐emitting diodes (LEDs). However, presently fabricated CsPbI3 polycrystalline films are composed of island‐like polycrystals, encountering the problems of serious interface current leakage and low‐efficiency carrier radiative recombination. Here, a CsPbI3‐xBrx quantum dots (QDs) matrix encapsulated CsPbI3 polycrystal film is reported to address the low‐efficiency issue of island‐like CsPbI3 polycrystalline film applied in deep‐red LEDs. The developed QDs matrix encapsulation strategy has two benefits. One is the filling of void space in the island‐like CsPbI3 polycrystal film to suppress the interface current leakage. The other more important benefit is utilizing the strong carrier confinement effect of QDs to strengthen the formation of excitons in the composite film and thus improve the electroluminescence efficiency. Moreover, interesting grain growth is found between CsPbI3‐xBrx QDs and CsPbI3 polycrystals, which further enhances the exciton transfer effect brought by the QDs matrix and optoelectronic properties of the fabricated composite films. Based on the obtained high‐quality QDs/polycrystal composite films, efficient and bright deep‐red LEDs are achieved with a peak external quantum efficiency of 15.24% and a maximum luminance of 3691 cd m−2. [ABSTRACT FROM AUTHOR]

The transdermal drug delivery system (TDDS) was created with the main goals of achieving extended pharmaceutical release, increasing bioavailability, and enhancing patient adherence. The matrix dispersion transdermal patch works by dispersing the drug and polymers in a solvent, which is then evaporated to leave a homogenous drug-polymer matrix. The goals of the present study were on designing and formulating TDDS for tirzepatide and afterwards assessing their in vitro performance characteristics. In diabetes mellitus, the pancreas either produces inadequate amounts of insulin or the body is unable to properly use the insulin that is generated. More than 415 million people worldwide have diabetes, and it is anticipated that by 2040, that number would reach 642 million. By 2030, diabetes will surpass heart disease as the seventh largest cause of death, according to the WHO. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of the L.N. Gumilyov Eurasian National University. Technical science & Technology series is the property of L.N. Gumilyov Eurasian National University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Calculation of the technological parameters of constrained extrusion of unequal channels is considered, for plane deformation, with misalignment of the punch and matrix; the extruded material may be of hardening or nonhardening type. The analytical expressions obtained permit determination of the total and specific deforming forces and the height of the walls that are formed. [ABSTRACT FROM AUTHOR]

Copyright of Duzce University Journal of Science & Technology is the property of Duzce University Journal of Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Although the eye can be subjected to therapeutic manipulation, some of its structures are highly inaccessible. Thus, conventional therapeutic administration pathways, such as topical or systemic routes, usually show significant limitations in the form of low ocular penetration or the appearance of side effects linked to physiology, among others. The critical feature of many xenobiotics is the drug gradient from the concentrated tear reservoir to the relatively barren corneal and conjunctival epithelia, which forces a passive route of absorption. The same is true in the opposite direction, towards the ocular surface (OS). With the premise that tears can be regarded as equivalent to or a substitute for plasma, researchers may determine drug concentrations in the OS fluid. Within this framework, a survey of scholarly sources on the topic was conducted. It provided an overview of current knowledge, allowing the identification of relevant theories, methods, and gaps in the existing research that can be employed in subsequent research. OS fluid (tears particularly) has enormous potential as a source of biological material for external drug screening and as a biomarker of various systemic diseases. Given the numerous alternate matrices, knowledge of their properties is very important in selecting the most appropriate specimens in toxicological analyses. [ABSTRACT FROM AUTHOR]

In this paper we study the multiplicative semigroup of 2 × 2 matrices over a linearly ordered abelian group with an externally added bottom element. The multiplication of such a semigroup is defined by replacing addition and multiplication by join and addition in the usual formula defining matrix multiplication. We show that there are four types of idempotents in such a matrix semigroup and we determine which of them are 0-primitive. We also prove that the poset of idempotents of such a matrix semigroup with respect to the natural order is a lattice. It turns out that such a matrix semigroup is inverse or orthodox if and only if the abelian group is trivial. [ABSTRACT FROM AUTHOR]

Matrix selection and application is a crucial step in obtaining meaningful results with matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI). Most instruments have a large spatial, and data with adequate spatial resolution can frequently be obtained on a benchtop instrument. The matrix application workflow has been optimized for the imaging of the earthworm (Eisenia hortensis), after exposure to various statins, a class of blood lipid-lowering agents. Lipids are nonpolar, often neutral molecules, making them difficult to ionize, and heightening the need for matrix optimization. The matrices 2,5-dihydroxybenzoic acid (DHB), a-cyano-4- hydroxycinammic acid (CHCA), 1,5-diaminonaphthalene (DAN), and 3,5- dimethoxy-4-hydroxycinnamic acid (sinapinic acid; SA) were studied. Samples were also washed in the ammonium salts of acetate, bicarbonate, formate, sulfate, or water as a control to enhance ionization and improve spatial resolution. A successful matrix for MSI is one that demonstrates homogenous tissue coverage, ionization of the analytes of interest, and does not require excessive laser power for ionization. All matrices showed sufficient tissue coverage; however, CHCA yielded unambiguous images of cholesterol and yielded sufficient signal over the lipid mass range (400-1,000m/z), indicating that it successfully ionized endogenous lipids. Following additional optimization, the application of 50 mL of 10 mg/mL CHCA following a 5 s salt ammonium sulfate salt wash proved most successful for improving lipid ionization and enhancing spatial resolution. [ABSTRACT FROM AUTHOR]