Binding Matrix Research Articles

Coupling effect of steel slag in preparation of calcium-containing geopolymers with spent fluid catalytic cracking (FCC) catalyst

Spent FCC catalyst coupling with steel slag has been used to synthesize a new calcium-containing geopolymer binding material with excellent performance. The effect of the composition of the raw materials on the performance of the obtained samples has been investigated systematically. The results indicate that the compressive strength of the prepared geopolymers was increased with the addition of steel slag. This is due to the calcium-containing components in the steel slag, which possess higher reactivity compared to the pure chemical reagent in the alkaline activation environment, which is beneficial for the generation of N(C)-A-S-H amorphous gel (where N = Na2O, A = Al2O3, C = CaO, S = SiO2, and H = H2O) in the obtained samples. Meanwhile, the other components of steel slag would embed in the cementitious material as skeleton materials, which are conducive for the improvement of the compressive strength performance. In addition, the role steel slag plays in the geopolymerization reaction has been studied by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectrometry (FT-IR). Results indicated that the catalyst-derived geopolymer gel (N-A-S-H) coexisted with slag activated gel (C-S-H/C-A-S-H) in the binding matrix, which are the main phases in the geopolymer, and the development of better compressive strength is attributed to the formation of Ca-rich gel phases. These results highlight the feasibility of using spent FCC catalyst and steel slag as raw materials for the production of geopolymer binding material with enhanced compressive strength.

Development of New Processes for the Decommissioning Decontamination and for Treatment and Disposal of the Secondary Low- and Intermediate-Level Radioactive Waste

As an example of research activities in decontamination for decommissioning, new data are presented on the options for corrosion layer dissolution during the decommissioning decontamination, or persulfate regeneration for decontamination solutions re-use. For the management of spent decontamination solutions, new method based on solvent extraction of radionuclides into ionic liquid followed by electrodeposition of the radionuclides has been developed. Fields of applications of composite inorganic-organic absorbers or solid extractants with polyacrylonitrile (PAN) binding matrix for the treatment of liquid radioactive waste are reviewed; a method for americium separation from the boric acid containing NPP evaporator concentrates based on the TODGA-PAN material is discussed in more detail. Performance of a model of radionuclide transport, developed and implemented within the GoldSim programming environment, for the safety studies of the LLW/ILW repository is demonstrated on the specific case of the Richard repository (Czech Republic). Continuation and even broadening of these activities are expected in connection with the approaching end of the lifespan of the first blocks of the Czech NPPs.

Do organic substances act as a degradable binding matrix in calcium oxalate kidney stones?

BackgroundCalcium oxalate (CaOx) stones are considered to be highly resistant to chemolysis. While significant organic matter has been identified within these stones, which is presumed to bind (inorganic) CaOx particles and aggregates, most chemolysis efforts have focused on methods to attack the CaOx components of a stone. We examine the feasibility of inducing chemolysis of CaOx kidney stones, within hours, by specifically attacking the organic matrix present in these stones.MethodsIn contrast to previous studies, we focused on the possible “brick and mortar” stone configuration. We systematically tested, via in vitro experiments, the ability of an extensive range of 26 potential chemolysis agents to induce relatively fast disintegration (and/or dissolution) of a large set of natural CaOx stone fragments, extracted during endourological procedures, without regard to immediate clinical application. Each stone fragment was monitored for reduction in weight and other changes over 72 h.ResultsWe find that agents known to attack organic material have little, if any, effect on stone chemolysis. Similarly, protein and enzymatic agents, and oral additive medical treatments, have little immediate effect.ConclusionsThese findings suggest that the organic and inorganic constituents present in CaOx stones are not structured as “brick and mortar” configurations in terms of inorganic and organic components.

Harnessing the Benefits of Neuroinflammation: Generation of Macrophages/Microglia with Prominent Remyelinating Properties.

Excessive inflammation within the CNS is injurious, but an immune response is also required for regeneration. Macrophages and microglia adopt different properties depending on their microenvironment, and exposure to IL4 and IL13 has been used to elicit repair. Unexpectedly, while LPS-exposed macrophages and microglia killed neural cells in culture, the addition of LPS to IL4/IL13-treated macrophages and microglia profoundly elevated IL10, repair metabolites, heparin binding epidermal growth factor trophic factor, antioxidants, and matrix-remodeling proteases. In C57BL/6 female mice, the generation of M(LPS/IL4/IL13) macrophages required TLR4 and MyD88 signaling, downstream activation of phosphatidylinositol-3 kinase/mTOR and MAP kinases, and convergence on phospho-CREB, STAT6, and NFE2. Following mouse spinal cord demyelination, local LPS/IL4/IL13 deposition markedly increased lesional phagocytic macrophages/microglia, lactate and heparin binding epidermal growth factor, matrix remodeling, oligodendrogenesis, and remyelination. Our data show that a prominent reparative state of macrophages/microglia is generated by the unexpected integration of pro- and anti-inflammatory activation cues. The results have translational potential, as the LPS/IL4/IL13 mixture could be locally applied to a focal CNS injury to enhance neural regeneration and recovery.SIGNIFICANCE STATEMENT The combination of LPS and regulatory IL4 and IL13 signaling in macrophages and microglia produces a previously unknown and particularly reparative phenotype devoid of pro-inflammatory neurotoxic features. The local administration of LPS/IL4/IL13 into spinal cord lesion elicits profound oligodendrogenesis and remyelination. The careful use of LPS and IL4/IL13 mixture could harness the known benefits of neuroinflammation to enable repair in neurologic insults.

Mechanical and durability-related performance of graphene/epoxy resin and epoxy resin enhanced OPC mortar

Abstract In this research, normal epoxy resin was reinforced by graphene nanosheets which was then used for improving mechanical properties and durability of ordinary Portland cement (OPC) mortars in terms of water sorptivity, resistance towards chloride penetration and freeze–thaw actions. Results showed that epoxy resin modified OPC mortar had a similar or lower compressive strength in the early curing ages whereas a higher one was obtained after 56 days of curing, especially for the mortar with the graphene addition. Flexural strength was all improved after the addition of epoxy resin, particularly for the graphene incorporated one. Besides, epoxy resin modified mortars were endowed with higher durability evidenced by lower capillary sorptivity and negligible mass loss and changes in relative dynamic modulus during freeze–thaw cycles, as compared to the normal OPC counterpart. With the addition of graphene, epoxy resin modified OPC mortar displayed an obvious lower chloride contents (especially at deeper depth) and capillary sorptivity. Microstructure analysis revealed that epoxy resin could refine the porous structure of the OPC mortar and graphene is able to enhance this benefit even further by densifying the mortar binding matrix. Considering the extremely small dosage of graphene but significant improvements in resistance against water ingress via capillary forces and chloride penetration, this novel method of combing graphene as a nanofiller with epoxy resin could be further utilised for OPC binders in practical aggressive engineering environments.

Transcriptome Analysis of Dnmt3l Knock-Out Mice Derived Multipotent Mesenchymal Stem/Stromal Cells During Osteogenic Differentiation.

Multipotent mesenchymal stem/stromal cells (MSCs) exhibit great potential for cell-based therapy. Proper epigenomic signatures in MSCs are important for the maintenance and the subsequent differentiation potential. The DNA methyltransferase 3-like (DNMT3L) that was mainly expressed in the embryonic stem (ES) cells and the developing germ cells plays an important role in shaping the epigenetic landscape. Here, we report the reduced colony forming ability and impaired in vitro osteogenesis in Dnmt3l-knockout-mice-derived MSCs (Dnmt3l KO MSCs). By comparing the transcriptome between undifferentiated Dnmt3l KO MSCs and the MSCs from the wild-type littermates, some of the differentially regulated genes (DEGs) were found to be associated with bone-morphology-related phenotypes. On the third day of osteogenic induction, differentiating Dnmt3l KO MSCs were enriched for genes associated with nucleosome structure, peptide binding and extracellular matrix modulation. Differentially expressed transposable elements in many subfamilies reflected the change of corresponding regional epigenomic signatures. Interestingly, DNMT3L protein is not expressed in cultured MSCs. Therefore, the observed defects in Dnmt3l KO MSCs are unlikely a direct effect from missing DNMT3L in this cell type; instead, we hypothesized them as an outcome of the pre-deposited epigenetic signatures from the DNMT3L-expressing progenitors. We observed that 24 out of the 107 upregulated DEGs in Dnmt3l KO MSCs were hypermethylated in their gene bodies of DNMT3L knock-down ES cells. Among these 24 genes, some were associated with skeletal development or homeostasis. However, we did not observe reduced bone development, or reduced bone density through aging in vivo. The stronger phenotype in vitro suggested the involvement of potential spreading and amplification of the pre-deposited epigenetic defects over passages, and the contribution of oxidative stress during in vitro culture. We demonstrated that transient deficiency of epigenetic co-factor in ES cells or progenitor cells caused compromised property in differentiating cells much later. In order to facilitate safer practice in cell-based therapy, we suggest more in-depth examination shall be implemented for cells before transplantation, even on the epigenetic level, to avoid long-term risk afterward.

МЕТОД ФИКТИВНЫХ РЕАКЦИЙ В МОДЕЛИРОВАНИИ КОНТАКТНОЙ ПОВЕРХНОСТИ НА ПРИМЕРЕ ФЛАНЦЕВЫХ СОЕДИНЕНИЙ

An iterative method for calculating flanged connections in the finite element formulation is proposed. The essence of the proposed method is to separate the contact problem into a separate localized process that depends only on the initial distribution of forces from the main load on the flange connection. In the initial matrix of stiffness of unrelated bodies, a binding matrix of contact with elements of high rigidity is added. The calculation is performed in two phases: the first phase determines the movement of the actual loads on the second, through a vector of dummy reactions, iterative specified voltage at the contact surfaces. The results obtained by the proposed method are compared with the experimental results and with the approximate calculation method.

A gentle acid-wash and pre-coating treatment of coral aggregate to manufacture high-strength geopolymer concrete

The coral reef fractures could be potentially used as aggregates for marine infrastructure construction, providing an alternative option to the high-cost gravel and sand aggregates. Coral aggregates are rough, porous and of low strength, which have a weak layer of minerals and microorganisms on the surface and a proportion of quartz inside pores. In the present study, using low concentration of acetic acid to pretreat coral aggregate was proposed to enhance the interface binding. When Portland cement was used as binder, the flexural and compressive strengths of cleaned coral aggregate concrete increased by 22.5% and 7.3%, respectively. Furthermore, the coral aggregate geopolymer concrete (CAGC) was prepared, given geopolymer acts as a strong binding and low porosity matrix, which is a promising material for the marine environment. To manufacture high-strength CAGC, a combined treatment method by gentle acid-wash cleaning and pre-coating of coral aggregate was proposed. The results showed that the mass loss rate of coral aggregate increased with the increase of acetic acid concentration and soaking time; the release of CO2 gas was helpful to remove the embedded sediment particles from the coral aggregates. Excessive acetic acid concentration and prolonged soaking time have adverse effects on the mechanical properties of CAGC, which was attributed to the corrosion of the internal skeleton of coral aggregate and the increase of connected pores. By using the gentle acid-wash and pre-coating method, a high-strength CAGC with compressive strength up to 60 MPa at 28-day was successfully manufactured, meeting the mechanical requirements of the most offshore construction requirements.

HIV-1 Gag release from yeast reveals ESCRT interaction with the Gag N-terminal protein region

The HIV-1 protein Gag assembles at the plasma membrane and drives virion budding, assisted by the cellular endosomal complex required for transport (ESCRT) proteins. Two ESCRT proteins, TSG101 and ALIX, bind to the Gag C-terminal p6 peptide. TSG101 binding is important for efficient HIV-1 release, but how ESCRTs contribute to the budding process and how their activity is coordinated with Gag assembly is poorly understood. Yeast, allowing genetic manipulation that is not easily available in human cells, has been used to characterize the cellular ESCRT function. Previous work reported Gag budding from yeast spheroplasts, but Gag release was ESCRT-independent. We developed a yeast model for ESCRT-dependent Gag release. We combined yeast genetics and Gag mutational analysis with Gag-ESCRT binding studies and the characterization of Gag-plasma membrane binding and Gag release. With our system, we identified a previously unknown interaction between ESCRT proteins and the Gag N-terminal protein region. Mutations in the Gag-plasma membrane–binding matrix domain that reduced Gag-ESCRT binding increased Gag-plasma membrane binding and Gag release. ESCRT knockout mutants showed that the release enhancement was an ESCRT-dependent effect. Similarly, matrix mutation enhanced Gag release from human HEK293 cells. Release enhancement partly depended on ALIX binding to p6, although binding site mutation did not impair WT Gag release. Accordingly, the relative affinity for matrix compared with p6 in GST-pulldown experiments was higher for ALIX than for TSG101. We suggest that a transient matrix-ESCRT interaction is replaced when Gag binds to the plasma membrane. This step may activate ESCRT proteins and thereby coordinate ESCRT function with virion assembly.

Lightweight Gypsum Materials with Potential Use for Thermal Insulations.

This article presents the influence of three additions i.e., hydroxyethyl methyl cellulose (HEMC), sodium bicarbonate and flue gas desulfurization (FGD) gypsum on the porosity of gypsum-based materials. The specific microstructure for a material with good thermal insulation properties i.e., numerous closed pores distributed in the binding matrix, was achieved using HEMC (0.3 wt.%) and sodium bicarbonate (0.5–2 wt.%). The addition of HEMC to the gypsum binder determines, as expected, an increase of the porosity due to its ability to stabilize entrained air. In the case of a sodium bicarbonate addition, the pores are formed in the binding matrix due to the entrapment of the gas (CO2) generated by its reaction. Sodium bicarbonate addition delays the setting of gypsum binder therefore in this study FGD gypsum (waste produced in the desulfurization process of combustion gases generated in power plants) was also added to the mixture to mitigate this negative effect. The decrease of geometrical density (up to 13%, in correlation with the additive nature and dosage) correlated with the increase of the porosity, determines, as expected, the decrease of flexural and compressive strengths (33–75%), but improves the thermal properties i.e., decreases the thermal conductivity (9–18%).

Compressed earth blocks stabilized with glass waste and fly ash activated with a recycled alkaline cleaning solution

Sustainable alternatives are increasingly demanded as a sound response, from the construction industry, to the worldwide growing concerns with the environment. Such effort is justifiable by the degree of the contribution of this human activity to the problem, and it has thus propelled the development of a major trend in terms of funded research. The study reported in this paper focused on the physical-mechanical properties of compacted earth blocks formed by a common Portuguese silty clay (as the mineral skeleton), stabilized with a sustainable alkali activated cement exclusively produced from wastes and residues, including coal fly ash and glass waste, in a 50/50 wt ratio combination, and activated with an alkaline solution from the aluminium industry, using activator/precursor weight ratios of 0.50, 0.57 and 0.75. After optimising the alkaline activated cement (AAC), the AAC/Soil blocks were fabricated, using the response surface method to define their composition based on curing periods of 28 and 180 days at controlled ambient temperature. Uniaxial compressive strength (UCS) and several durability tests were performed, and the material was characterised using FTIR and SEM. The results evidenced the effectiveness of the alkaline cementing agent in forming a binding matrix for the soil particles. An average compressive strength of 17.23 MPa, in unsaturated conditions, was obtained for the blocks. The newly formed soil-binder structure was very capable to withstand wetting and drying cycles, ice-thaw cycles and erosion. The microstructure of the material was further analysed, using scanning electron microscopy and energy dispersive spectroscopy. The results demonstrated the real possibility of using this type of cement as a viable alternative to traditional soil stabilisation binders used in earth construction.

Tungsten-chromium coatings on reduced activation ferritic/martensitic steels prepared by laser melting deposition process

Tungsten-chromium alloys are promising plasma facing materials in future fusion reactors considering the loss of coolant accident (LOCA). A laser melting deposition (LMD) additive manufacturing technique has been used in this study to deposit 90W-10Cr coatings on reduced activation ferritic/martensitic (RAFM) steels. The results show that the coatings have metallurgical bonding with the RAFM steel substrates. The W-steel joint have graded transitions of compositions, microstructures, and phases along the deposition direction due to the dilution effects of the substrates, which are beneficial to reduce thermal stresses of W-steel joints. Pores and cracks are seen in the coatings prepared using different process parameters. Low and high input energy densities can both lead to pore formations due to the combined effects of lack of fusion, residual of delivered gas, and evaporations of low melting point elements. Cracking is driven by the internal stress during LMD process and liquation of binding matrix. Fe7W6 intermetallics are mainly formed near the bonding boundaries of W-steel joint, showing a dispersed distribution either scattered in the matrix or surrounding the scattered W particles. The top and mid-top regions of coatings have unique microstructures showing W particles embedded in Cr-Fe based matrix, which are supposed to have reliable performance both during the operations of reactors and the LOCA.

Microbial Biofilms in the Proshchal’naya Karst Cave (Far East, Russia)

Effect of abiotic (composition of drip and fracture water) and biotic factors (composition and activity of microbial complexes) on biofilm formation in the Proshchal’naya karst cave (Far East, Russia) is reported. The effect of natural infiltration water on the structure of cultured microbial complexes and on the elemental composition of the moonmilk speleothem formed on the walls of the cave was studied. The highest concentrations of Fe and Mn were observed in drip water in spring. Organic compounds were shown to have an important effect on the rates of microbial processes at the water–rock interface, on the moonmilk elemental composition, and on the structure of communities involved in carbonate precipitation. The structure of moonmilk microbial communities was investigated using culture-based techniques and quantitative PCR analysis. Iron bacteria of the genera Rhodoferax and Geothrix, as well as Bacillus species, were identified in moonmilk samples. The microstructure and elemental composition of moonmilk samples from the Proshchal’naya cave were investigated by scanning electron microscopy coupled to X-ray microanalysis. SEM images of the moonmilk mass revealed diverse microstructures and high heterogeneity. Tubular microstructures contained more elements (C, O, Ca, Fe, Mn, Si, Al, and S) than claviform structures consisting of calcium carbonate (СаСО3). The moonmilk binding matrix consisted of thin nanofibers.

Tensile strength of granular aggregates: Stress chains across particle phase versus stress concentration by pores.

We use the bond-based peridynamics approach to analyze the strength and fracture of dense granular aggregates with variable amount of a solid binding matrix, distributed according to a simple protocol in the interstitial space between particles. We show the versatility of the peridynamics approach in application to crack propagation and its scaling behavior in a homogeneous medium (in the absence of particles and pores). Then we apply this method to simulate the deformation and failure of aggregates as a function of the amount of the binding matrix under tensile loading. We find that the tensile strength is a strongly nonlinear function of the matrix volume fraction. It first increases slowly and levels off as the gap space in-between touching particles is gradually filled by the binding matrix, up to nearly 90% of the total pore volume, and then a rapid increase occurs to the maximum strength as the remaining interstitial space, composed of isolated pores between four or more particles, is filled. By analyzing the probability density functions of stresses in the particle and matrix phases, we show that the adhesion of the matrix to the particles and the thickening of stress chains (i.e., stresses distributed over larger cross sections) control the strength in the first case whereas the homogenizing effect of the matrix by filling the pores (hence reducing stress concentration) is at the origin of further increase of the strength in the second case. Interestingly, these two mechanisms contribute almost equally to the total strength.

Conductive Polyacrylic Acid-Polyaniline as a Multifunctional Binder for Stable Organic Quinone Electrodes of Lithium-Ion Batteries.

High solubility in aprotic organic electrolytes and poor electrical conductivity are the main restrictions of organic electrodes in practical application. Conductive binder contributes to the high-performance electrodes as it enables both mechanical and electronic integrity of the electrode, which have been scarcely explored for organic electrodes. Herein, a conductive interpenetrating polymeric network is synthesized through in situ polymerization of polyaniline with poly(acrylic acid) (denoted PAA-PANi), which served as a novel conductive binder for organic 2-aminoanthraquinone (AAQ) materials. The conductive PANi component enhances the electrical conductivity of the electrode. Meanwhile, the PAA component serves as the binding matrix to condense with the amino groups (-NH2) of AAQ, which therefore effectively inhibits their dissolution and maintains electrode integrity during cycling. As expected, the conductive binder exhibits both excellent electrical conductivity (10-3 S cm-1) and strong mechanical adhesion. The AAQ/reduced graphene oxide (AAQ@rGO) composite electrode prepared with the as-synthesized PAA-PANi binder delivers a high specific capacity of 126.1 mAh g-1 at 0.1 A g-1, superior rate capability (71.3 mAh g -1 at 3 A g-1), and outstanding cycling stability (2000 cycles at 1 A g-1), which greatly rivals polyvinylidene fluoride and PAA binder-based electrodes. Such a strategy points the way for the design and synthesis of conductive polymeric binders for organic electrodes, whose electrical conductivity and dissolution are massive issues.

EDX/XRD-based identification of micrometer-sized domains in scanning electron micrographs of fired clay

The thermal and mechanical properties of bricks are strongly dependent on both the chemical composition and the microstructural features of the used fired clay material. Focussing on the latter, we here identify, in terms of volume fraction, shape, and orientation characteristics, one-to-several micrometer-sized subdomains (“material phases”) within the SEM-imaged microstructure of two raw clays fired at 880 and 1100 centigrades: (1) quartz grains, (2) muscovite, (3) Fe–Mg mica, (4) feldspar grains, (5) decarbonated dolomite, (6) pores, or (7) binding matrix. This identification rests on the simultaneous use of Scanning Electron Microscopy (SEM) and Energy-dispersive X-ray spectroscopy (EDX), with correspondingly obtained data entering statistical analyses based on the Otsu algorithm, and complemented by minimum grain size and grain shape requirements, as well as by logical exclusion criteria. Crystalline and amorphous phase shares were additionally confirmed by X-ray powder diffraction measurements (PXRD). As for the investigated clays, an increased firing temperature results in dehydroxylation of muscovite, and in a reduced appearance of feldspar grains.

A description of structured waves in shock compressed particulate composites

Dynamic compression of composite materials is of scientific interest because the mechanical mismatch between internal phases challenges continuum theories. Typical assumptions about steady wave propagation and quasi-instantaneous state changes require reexamination along with the need for time-dependent models. To that end, data and models are presented for the shock compression of an idealized particulate composite. To serve as a generic representative of this material class, a polymer matrix was filled with tungsten particles, ranging from 1 to 50 vol. %. This creates a simple microstructure containing randomly scattered particles with an extreme impedance mismatch to the binding matrix. These materials were parallel plate impact loaded by Al flyers traveling at 1.8–5.0 km/s. Velocimetry provided records of the equilibrium state and the compression wave structure for each case with trends quantified by an empirical fit. The same quantities were also studied as a function of the wave's propagation distance. A homogenized viscoelastic model then made it possible to progress from cataloging trends to making predictions. Starting from a Mie–Gruneisen equation of state, additional time varying terms were added to capture the transient response. After calibration, accurate predictions of the steady wave structure were possible.

Morphological study of a cubic boron nitride (CBN) cutting tool and characterization of its wear scenarios in abrasive machining process

Cubic boron nitride (CBN) composites are usually fabricated by sintering abrasive particles and binder powders under certain temperature and vacuum conditions. As a result, the inherent geometrical inhomogeneity of the abrasive grains in the binding matrix becomes an important intrinsic characteristic. In abrasive machining, the surface quality of workpieces is determined, to some extent, by the morphological characteristics of the grains extruded out of cutting surfaces. Within this regard, this work aims to characterize the morphological characteristics and to assess the wear modalities of CBN grains, at the same time to find out their eventual correlations. In doing so, a commercial CBN honing tool, namely B151/L2/10/50 (B151), is chosen as target material. A 3D model of a selected volume was reconstructed by applying cross-sectioning and digital image processing methods. Based on the grain segmentation and quantification, morphological characteristics of the grains are individually and statistically analyzed. Wear scenarios of the tool were characterized after cutting tests. Grains were found to have commonalities in shape and dimension on a microscale perspective despite their inhomogeneous distribution. Wear modalities are strongly related to the morphological characteristics of the grains. Specifically, degradation commences at spikes, with fractures initiating along the grain edges by either splitting grains and binder or intruding into the grains.

Stress transmission in cemented bidisperse granular materials.

We analyze stress distributions in a two-dimensional bidisperse cemented granular packing for a broad range of the values of particle-size ratio, the volumes of large and small particles, and the amount of cementing matrix. In such textured porous materials, the stress concentration, which controls the fracture and fragmentation of the material under tensile loading or in grinding processes, reflects not only the porosity but also the contact network of the particle phase and the resulting stress chains. By means of peridynamic simulations under tensile loading, we show how both the texture and stress distribution depend on size ratio, volume ratio, and the amount of the cementing matrix. In particular, the volume fraction of the class of small particles plays a key role in homogenizing stresses across the system by reducing porosity. Interestingly, the texture controls not only the porosity but also the distribution of pores inside the system with its statistical variability, found to be strongly correlated with the homogeneity of stresses inside the large particles. The most homogeneous stress distribution occurs for the largest size ratio and largest volume fraction of small particles, corresponding to the lowest pore size dispersion and the cushioning effect of small particles and its similar role to the binding matrix for stress redistribution across the packing. At higher porosity, the tensile stresses above the mean stress fall off exponentially in all phases with an exponent that strongly depends on the texture. The exponential part broadens with decreasing matrix volume fraction and particle-size ratio. These correlations reveal the strong interplay between size polydispersity and the cohesive action of the binding matrix for stress distribution, which is significant for the behavior of textured materials in grinding operations.

Integrated bioinformatics analysis of expression and gene regulation network of COL12A1 in colorectal cancer.

The extracellular matrix (ECM) is reported to be involved in tumorigenesis and progression. Collagen IIX is a major ECM protein. Abnormal COL12A1 expression is associated with carcinogenesis of colorectal cancer (CRC), but its clinical value and function have not yet been analyzed. Expression, methylation, and survival were analyzed by using Oncomine, UNCLA, and GEPIA, while COL12A1 alterations and related functional networks were identified using cBioPortal. The gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathways（KEGG）of COL12A1 in CRC were explored using LinkOmics. Gene set enrichment analysis (GSEA) examined target networks of kinases, miRNAs, and transcription factors. We found that COL12A1 was overexpressed in CRC and the COL12A1 gene was often amplified in CRC. Survival analysis revealed that patients with higher COL12A1 expression had a poor prognosis. Expression of COL12A1 was linked to functional networks via regulating pathways involving focal adhesion, PI3K‐Akt signaling pathway, and ECM‐receptor interaction. Functional network analysis suggested that COL12A1 regulated integrin binding, collage binding, and extracellular matrix structural constituent via pathways involving some several cancer‐related kinases, miRNAs, and transcription factor. Furthermore, other FACITs genes (COL1A2, COL3A1, COL5A1, COL5A2, and COL6A3) for ECM in correlation with COL12A1 were identified to be related with the prognosis in CRC. These results suggested that the distinct fibril‐associated collagens with interrupted triple helices (FACITs) genes may serve as prognostic and therapeutic biomarkers of CRC in the future.