Dispersion Characteristics, the Mechanical, Thermal Stability, and Durability Properties of Epoxy Nanocomposites Reinforced with Carbon Nanotubes, Graphene, or Graphene Oxide.

Carbon-based nanoparticles (CBNs) are regarded as promising nanofillers in nanocomposites to produce high-performance fiber-reinforced polymers (FRPs). To date, no systematic investigations have been carried out on the structural variations of nanofillers and their influences on dispersion characteristics, which give nanocomposites their mechanical and durability properties. Moreover, environmentally unfriendly organic solvents are used to exfoliate and disperse CBNs in a polymer matrix. This study developed a green, easy approach to preparing epoxy/CBN nanocomposites. We demonstrated graphene oxide's (GO) effective dispersion capacity, creating good interface interaction that dramatically influenced properties at loadings as low as 0.4 wt%. The tensile strength and toughness of the epoxy increased by about 49%; and 160%, respectively. Incorporating 0.4 wt% of multi-wall carbon nanotubes (MWCNTs), graphene nanoplates (GNPs), or GO into the epoxy increased the modulus storage by around 17%, 25%, and 31%, respectively. Fractography analysis of fracture surfaces indicated the primary reinforcing mechanisms (crack deflection and penning) as well as the secondary mechanism (bridging effect) enhancing the mechanical characteristics of nanocomposites. Incorporating GNPs, GO, or MWCNTs into the epoxy decreased the water absorption at saturation by about 26%, 22%, and 16%, respectively.

Rational synthesis of methylsilsesquioxane aerogels addressing thermal load and compression recovery issues in Li-ion batteries.

Li-ion batteries suffer from two key safety issues: thermal overload and compression recovery, which may lead to flammability and mechanical failure. Silica aerogels are promising solutions to both these issues owing to their excellent thermal stability and tailored mechanical properties. However, finding the optimum sol composition in sol-gel-based aerogel synthesis is needed to address these issues at industry-relevant scales. Here, we propose an innovative approach to determine the optimum sol composition for methylsilsesquioxane (MSQ) aerogel sheets, which is based on the mechanisms of the effects of molar ratios of hydrolysis water and isopropyl alcohol (IPA) to methyltrimethoxysilane (MTMS) on the physical properties of MSQ aerogel sheets and according to the ternary contour distribution of their properties. The synthesized MSQ aerogels exhibited a soft, light, and powderless texture and featured superhydrophobic properties (150.2°), low thermal conductivity of 33.6 mW/(m·K), high thermal stability temperature in nitrogen atmosphere at 479.3 °C and moderate short-term (<6 h) service temperature of 120.0 °C. Significantly, the structural stability and elasticity of the aerogels surpassed the current state-of-the-art, showing recovery to 81.3 % of the original thickness and 85.2 % of the original stress after being subjected to 400 cycles of high-speed and high-strain consecutive compression, respectively. These excellent properties make the MSQ aerogel sheets promising for applications in thermal load and compression recovery management of diverse energy storage devices, including batteries for next-generation electric vehicles.

Influence of an Engineered Notch on the Electromagnetic Radiation Performance of NiTi Shape Memory Alloy.

This work explores the influence of a pre-engineered notch on the electromagnetic radiation (EMR) parameters in NiTi shape memory alloy (SMA) during tensile tests. The test data showed that the EMR signal fluctuated between oscillatory and exponential, signifying that the specimen's viscosity damping coefficient changes during strain hardening. The EMR parameters, maximum EMR amplitude, and average EMR energy release rate remained constant initially but rose sharply with the plastic zone radius with progressive loading. It was postulated that new Frank-Read sources permit dislocation multiplication and increase the number of edge dislocations participating in EMR emissions, leading to a rise in the value of EMR parameters. The study of the correlation between EMR emission parameters and the plastic zone radius before the crack tip is a vital crack growth monitoring tool. An analysis of the interrelationship of the EMR energy release rate at fracture with the elastic strain energy release rate would help develop an innovative approach to assess fracture toughness, a critical parameter for the design and safety of metals. The microstructural analysis of tensile fractures and the interrelation between deformation behaviours concerning the EMR parameters offers a novel and real-time approach to improve the extant understanding of the behaviour of metallic materials.

Preparation and Characterization of Novel Sulfoaluminate-Cement-Based Nonautoclaved Aerated Concrete.

The production of autoclaved aerated concrete via the autoclaving process incurs substantial energy consumption, posing a challenge to sustainable economic development. Herein, a novel nonautoclaved aerated concrete (NAAC) was prepared using sulfoaluminate cement as the primary raw material and aluminum powder as the aerating agent. The physicomechanical characteristics and pore structures of the sulfoaluminate-cement-based (SAC) NAAC (SAC-NAAC) were examined through X-ray diffraction, thermogravimetry, and scanning electron microscopy. The findings revealed that the optimal mechanical attributes of the SAC-NAAC were achieved at a water-cement ratio of 0.55, with a specific content ratio of polycarboxylate superplasticizer-borax-calcium stearate-sodium hydroxide at 0.24%:0.32%:0.36%:2.90%, along with 0.40% aluminum powder. The SAC-NAAC samples, with a bulk density range of 600-750 g/m3, exhibited a compressive strength of 3.55-4.16 MPa, porosity of 45.9-63.5%, and water absorption rate of 60.2-74.4%. The weight loss in the SAC-NAAC with different aluminum powder contents ranged between 15.23% and 16.83%. The prismatic ettringite (AFt) crystals served as the main source of strength for the SAC-NAAC, and AH3 was attached to the AFt surfaces in a microcrystalline gel phase, thereby further enhancing the strength of the SAC-NAAC. Thus, the lightweight, high-strength SAC-NAAC has great potential as a nonautoclaved aerated concrete.

Investigation the effect of dissimilar laser welding parameters on temperature field, mechanical properties and fusion zone microstructure of inconel 600 and duplex 2205 stainless steel via response surface methodology.

This study focused on dissimilar welding characterization of Inconel 600 and duplex 2205 stainless steel using central composite design (CCD) of experiments the response surface methodology (RSM). This study determined the effect of laser welding parameters and the reactions of the temperature field on the melt pool, the mechanical characteristics of the weld joint, and the geometry of the melt pool. According to the ANOVA results, the power of laser and focal distance were found to be the most influential factors on the temperature of both Inconel 600 and duplex stainless steel. The weld joint's tensile strength and elongation were significantly influenced by laser power and focal distance. Increasing the laser power from 250 to 450 W raised the tensile strength from 250 to 550 MPa. The Mo rich phases formed at the inter-dendritic region according to the EDS phase analysis results in loss of ductility and the resultant tensile strength of the samples failure from the fusion zone adjacent to the duplex stainless steel. At high laser power levels, the samples fractured from fusion zone while at lower laser powers below 350 W, the samples fractured from the HAZ and the areas adjacent to the duplex steel fusion line. The micro-hardness value of the weld joint at different laser power of 525 W and 375 W was increased to the maximum values of 370 and 325 HV, respectively from the fusion line of Inconel 600 to the center of the fusion zone. Further, molten pool microstructure of the dissimilar joint zone was mainly composed of a cellular and columnar dendritic structure Variations in melt flow, temperature gradient and solidification rate from the molten scan line to the weld center clearly changed the grain growth and the resultant microstructure in different areas of the fusion zone. By transferring the laser light to the center of the Inconel 600 and duplex stainless steel joint, the molten pool depth was increased from 0.2 to 1.5 mm.

Effect of cooking on structural changes in the common black bean (Phaseolus vulgaris var. Jamapa).

The cooking process is fundamental for bean consumption and to increase the bioavailability of its nutritional components. The study aimed to determine the effect of cooking on bean seed coat through morphological analyses with different microscopy techniques and image analyses. The chemical composition and physical properties of raw black bean (RBB) and cooked black bean (CBB) seeds were determined. The surface and cross-sectional samples were studied by Optical microscopy (OM), environmental scanning electron microscopy (ESEM), atomic force microscopy (AFM) and confocal laser scanning microscopy (CLSM). The composition of samples showed significant differences after the cooking process. OM images and gray level co-occurrence matrix algorithm (GLCM) analysis indicated that cuticle-deposited minerals significantly influence texture parameters. Seed coat surface ESEM images showed cluster cracking. Texture fractal dimension and lacunarity parameters were effective in quantitatively assessing cracks on CBB. AFM results showed arithmetic average roughness (Ra) (121.67 nm) and quadratic average roughness (Rq) (149.94 nm). The cross-sectional ESEM images showed a decrease in seed coat thickness. The CLSM results showed an increased availability of lipids along the different multilayer tissues in CBB. The results generated from this research work offer a valuable potential to carry out a strict control of bean seed cooking at industrial level, since the structural changes and biochemical components (cell wall, lipids and protein bodies) that occur in the different tissues of the seed are able to migrate from the inside to the outside through the cracks generated in the multilayer structure that are evidenced by the microscopic techniques used.

Synthesis of Vinyl-Containing Polydimethylsiloxane in An Active Medium.

This research deals with the synthesis of copoly(methylvinyl)(dimethyl)siloxanes by the copolycondensation of dimethyldiethoxy- and methylvinyldimethoxysilane in an active medium, followed by thermal condensation in a vacuum. We achieved a range of copolymers exhibiting finely tuned molecular weights spanning between 1500 and 20,000 with regulated functional methylvinylsiloxane units. Analysis of the microstructure showed that the copolymerization predominantly formed products demonstrating a random distribution of units (R~1). However, an increase in the content of vinyl-containing monomers increases the R parameter, indicating an enhanced tendency towards alternating linkages within the copolymer matrix.

Dental zirconia microwave-sintering followed by rapid cooling protocol.

OBJECTIVES: This study aimed to evaluate the effect of microwave sintering temperature and cooling rate (MS) on 3Y-TZP ceramics and its influence on the ceramic microstructure and mechanical properties. Specifically, to optimize the sintering process, reducing the total sintering time compared to conventional sintering. MATERIALS AND METHODS: Eighty-four pre-sintered Y-TZP discs (Vipi block Zirconn, VIPI) (ISO 6872) were divided into seven groups (n = 12) according to the sintering conditions: conventional sintering (CS) at 1530 °C for 120 min and microwave sintering at 1400 °C (MS1400) and 1450 °C (MS1450) for 15 min followed by different cooling conditions: rapid cooling (RC), cooling at 400 °C (C400) and 25 °C (C25). The specimens were submitted to apparent density measurements, X-ray diffraction analysis (XRD), scanning electron microscopy, and biaxial flexural strength test. Data was statistically analyzed through two-way ANOVA, Tukey, Sidak, Dunnett and Weibull (α = 0.05). RESULTS: All MS1400 groups presented lower density values than the CS and MS1450 groups. Two-way ANOVA revealed that the MS temperature and cooling rate affected the biaxial flexural strength of the Y-TZP (p < 0.01). Group MS1400RC presented lower biaxial flexural strength values (681.9 MPa) than MS1450RC (824.7 MPa). The cooling rate did not statistically decrease the biaxial strength among the groups submitted to microwave sintering at 1450 °C. XRD analysis showed that the sintering and cooling temperature did not induce tetragonal to monoclinic phase transformation. CONCLUSIONS: Microwave sintering at 1450 °C for 15 min followed by rapid cooling can be a viable fast alternative protocol for Y-TZP sintering, compared with the conventional sintering, reducing the total sintering time by 75% and reducing the energy used for the sintering process without affecting the Y-TZP biaxial flexural strength and relative density compared to the conventional sintering. Moreover, the microwave technique promoted smaller grains and did not induce monoclinic phase formation.

Comparison of Additively Manufactured Polymer-Ceramic Parts Obtained via Different Technologies.

This paper aims to compare two ceramic materials available for additive manufacturing (AM) processes-vat photopolymerization (VPP) and material extrusion (MEX)-that result in fully ceramic parts after proper heat treatment. The analysis points out the most significant differences between the structural and mechanical properties and the potential application of each AM technology. The research revealed different behaviors for the specimens obtained via the two mentioned technologies. In the case of MEX, the specimens exhibited similar microstructures before and after heat treatment. The sintering process did not affect the shape of the grains, only their size. For the VPP specimens, directly after the manufacturing process, irregular grain shapes were registered, but after the sintering process, the grains fused, forming a solid structure that made it impossible to outline individual grains and measure their size. The highest compression strength was 168 MPa for the MEX specimens and 81 MPa for the VPP specimens. While the VPP specimens had half the compression strength, the results for the VPP specimens were significantly more repeatable.

Influence of Coal Gangue Powder on the Macroscopic Mechanical Properties and Microstructure of Recycled Aggregate Concrete.

The construction and coal industries generate substantial industrial waste, including coal gangue and construction and demolition (C&D) waste, leading to environmental pollution and high disposal costs. Integrating recycled aggregates (RAs) and coal gangue powder (CGP) into concrete is an effective approach for waste management. However, CGP can affect the performance of traditional recycled concrete. This study primarily aims to optimize the utilization of RAs and CGP while maintaining concrete performance. They utilized orthogonal experimental designs and microscopic characterization techniques, including scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). Orthogonal experimental analysis indicated that with a water-cement ratio (WCR) of 0.5 and replacement rates of 10% for CGP and 60% for RA, compressive and splitting tensile strengths reached 73.6% and 77.4% of ordinary C30 concrete, respectively. This mix proportion minimizes strength decline in coal gangue powder-recycled aggregate concrete (CGP-RAC) while maximizing recycled material replacement. Microscopic analysis revealed that CGP increased the Ca/Si ratio in cement paste, impeding hydration reactions, resulting in a looser internal structure and reduced concrete strength. These findings are anticipated to provide fresh theoretical insights for solid waste recycling and utilization.

Evolution of Manufacturing Defects of 3D-Printed Thermoplastic Composites with Processing Parameters: A Micro-CT Analysis.

Owing to the melting and healing properties of thermoplastic resin, additive manufacturing or 3D printing is considered one of the most promising technologies for fiber-reinforced thermoplastic composites. However, manufacturing defects are still the main concern, which significantly limits the application of 3D-printed composite structures. To gain an insight into the effects of different processing parameters on the typical manufacturing defects, a micro-scale analysis was carried out via Micro-CT technology on the 3D-printed continuous carbon fiber-reinforced polylactic acid (PLA) composite specimens. The bias distribution of the fiber in the deposited filament was found. Moreover, when the feed rate of the filament was reduced from 100% to 50%, the a/b value was closer to 3.33, but the porosity increased from 7.077% to 25.352%. When the layer thickness was 0.2 mm, the increased nozzle pressure reduced the porosity but also increased the risk of fiber bundle breakage. The research provides an effective approach for analyzing the micro-structure of 3D printed composite structures and thus offers guidance for the processing control.

Biodegradable Magnesium Alloys for Personalised Temporary Implants.

The objective of this experimental work was to examine and characterise the route for obtaining demonstrative temporary biodegradable personalised implants from the Mg alloy Mg-10Zn-0.5Zr-0.8Ca (wt.%). This studied Mg alloy was obtained in its powder state using the mechanical alloying method, with shape and size characteristics suitable for ensuing 3D additive manufacturing using the SLM (selective laser melting) procedure. The SLM procedure was applied to various processing parameters. All obtained samples were characterised microstructurally (using XRD-X-ray diffraction, and SEM-scanning electron microscopy); mechanically, by applying a compression test; and, finally, from a corrosion resistance viewpoint. Using the optimal test processing parameters, a few demonstrative temporary implants of small dimensions were made via the SLM method. Our conclusion is that mechanical alloying combined with SLM processing has good potential to manage 3D additive manufacturing for personalised temporary biodegradable implants of magnesium alloys. The compression tests show results closer to those of human bones compared to other potential metallic alloys. The applied corrosion test shows result comparable with that of the commercial magnesium alloy ZK60.

Demineralized dentin matrix technique - a comparison of different demineralizing solutions

Abstract This study aimed to evaluate the microstructure formed after the chemical treatment of teeth, for the development of autogenous grafts from the demineralized dentin matrix (DDM) technique, in order to identify the most efficient demineralizing solution. The specimens, originating from the root and coronal portion, were submitted to ultrasonic cleaning and drying in an oven for 1h at 100 ºC. Then, the density was determined by Archimedes' principle for each specimen, using distilled water as immersion liquid. The samples were separated into five groups: Control group: negative control, Distilled water;EDTA group: positive control, trisodium EDTA; NaOCl group: 2.5% sodium hypochlorite; HCl-0.6M group: 0.6M hydrochloric acid; and H2O2/H2SO4 group: hydrogen peroxide and sulfuric acid. Each specimen was immersed for 1h in the corresponding group descaling solution at 60 ºC. Subsequently, the mass loss and density of the treated specimens were determined by Archimedes' principle. Ultimately, the specimens of each group were characterized by microtomography, Scanning Electron Microscopy, and Energy Dispersive Spectrometry X-ray (SEM-EDS). The results demonstrated that the H2O2/H2SO4 solution allowed the formation of interconnected micropores, suggesting better pore structures for application in scaffolds, when compared to the other studied solutions.

Resumo Este estudo teve como objetivo avaliar a microestrutura formada após o tratamento químico em dentes, para o desenvolvimento de enxertos autógenos a partir da técnica de matriz de dentina desmineralizada (DDM), a fim de identificar a solução desmineralizante mais eficiente. Os espécimes, provenientes da raiz e porção coronal, foram submetidos à limpeza ultrassônica e secagem em estufa por 1h a 100 ºC. Em seguida, a densidade foi determinada pelo princípio de Arquimedes para cada espécime, utilizando água destilada como líquido de imersão. As amostras foram separadas em cinco grupos: Controle: controle negativo, Água destilada; EDTA: controle positivo, EDTA trissódico; NaOCl: hipoclorito de sódio 2,5%; HCl-0.6M: ácido clorídrico 0,6M; e H2O2/H2SO4: peróxido de hidrogênio e ácido sulfúrico. Cada espécime foi imerso por 1h na solução descalcificante de grupo correspondente a 60 ºC. Posteriormente, a perda de massa e a densidade dos espécimes tratados foram determinadas pelo princípio de Arquimedes. Por fim, os espécimes de cada grupo foram caracterizados por microtomografia, microscopia eletrônica de varredura e espectrometria de energia dispersiva de raios-X (SEM-EDS). Os resultados demonstraram que a solução H2O2/H2SO4 permitiu a formação de microporos interligados, sugerindo melhores estruturas de poros para aplicação em scaffolds, quando comparada às demais soluções estudadas.

Analysis of Phenomenon of Plasticity Loss of Steel Core Made by Selective Laser Melting Method in Zone of Pressure Mould Conformal Cooling Channel.

This paper presents the results of testing the mechanical properties of maraging steel 1.2709 that were obtained by the SLM method under uniaxial and triaxial states of stress. The triaxial state of stress was realised by making circumferential notches in the samples with different radii of rounding. The specimens were subjected to two types of heat treatment, which consisted of ageing at 490 °C and 540 °C for 8 h. The results of the tests that were conducted on the samples were considered as references and compared with the results of the strength tests that were conducted directly on the SLM-made core model. Differences were found between the results of these tests. Based on the experimental results, the relationship between the equivalent strain of the specimen in the bottom of notch εeq and triaxiality factor η was determined. Function εeq = f(η) was proposed as a criterion for the decrease in the plasticity of the material in the area of the pressure mould cooling channel. Using the FEM method, equivalent strain field εeq and triaxiality factor η were determined in the conformal channel cooled core model. Based on the proposed criterion of plasticity loss and the results of numerical calculations, it was shown that the values of equivalent strain εeq and triaxiality factor η in the core that was aged at 490 °C did not meet this criterion. On the other hand, the values of strain εeq and triaxiality factor η did not exceed the safety limit when ageing was carried out at 540 °C. The plasticity loss method presented in this paper assumes that the value of the triaxiality factor in the vicinity of the channel is influenced by the shape, cross-sectional dimensions and trajectory of the channel axis. Using the methodology proposed in this paper, it is possible to determine the value of allowable deformations in the cooling channel zone and to determine whether the heat treatment applied to the SLM steel does not cause an excessive reduction in the plastic properties.

El consumo de bebidas dulces incrementa diferencialmente la expresión de Oxitocina en núcleos hipotalámicos / The consumption of sweet drinks differentially increases the expression of oxytocin in hypothalamic nuclei

Resumen Se reconoce la participación de la oxitocina en el control de la alimentación, pero su mecanismo de acción no se ha establecido totalmente. Por tanto, el objetivo de esta investigación fue evaluar el efecto del acceso intermitente a una solución de sacarosa, sobre la expresión de las neuronas del núcleo paraventricular (PVN) y del núcleo supraótico (SON) que producen oxitocina (Oxt), y caracterizar la microestructura de la conducta de beber en ratas saciadas. Se tuvieron tres grupos de ratas macho Wistar saciadas, y en la primera hora al inicio del periodo de luz, el grupo Control tuvo agua, el grupo Restringido 5g de una solución de sacarosa al 20% y el grupo Ad libitum acceso libre a la solución de sacarosa. Los sujetos incrementaron el consumo de la solución de sacarosa a pesar de estar saciados; debido a la interrupción del estado de saciedad y la demora de la satisfacción. La actividad de las neuronas de Oxt se incrementó en ambos núcleos, en el grupo Restringido la mayor expresión se observó en el SON y en el grupo Ad libitum en el PVN. No se encontró correlación entre la cantidad de bebida ingerida y la actividad de las neuronas Oxt.

Abstract The role of oxytocin in feeding control is recognized, but its mechanism of action has not been fully established. Therefore, the aim of this research was to evaluate the effect of intermittent access to a sucrose solution on the expression of paraventricular nucleus (PVN) and supraotic nucleus (SON) neurons that produce oxytocin (Oxt), and to characterize the microstructure of drinking behavior in satiated rats. Three groups of male Wistar rats satiated were used, and in the first hour at the beginning of the light period, a Control group had water, a Restricted group 5g of a 20% sucrose solution and Ad libitum group with free access to sucrose solution. The experimental subjects increased the consumption of the sucrose solution despite being satiated, due to the interruption of the state of satiety and the delay of the satiation process. Oxt neurons increased their activity in both nuclei, in the Restricted group the highest expression was observed in the SON and in the Ad libitum group in the PVN. No correlation was found between the amount of drink ingested and the activity of Oxt neurons.

Surfactant gel-based method: A universal soft method for the exfoliation of 2D materials.

HYPOTHESIS: Fluidic micelles and reverse micelles have served as exfoliation mediums. However, an additional force, such as extended sonication, is required. Gelatinous cylindrical micelles that are formed once desired conditions are achieved can be an ideal medium for the quick exfoliation of 2D materials without the need for any external force. The quick formation of gelatinous cylindrical micelles can rip off layers from the 2D materials suspended in the mixture leading to the quick exfoliation of 2D materials. EXPERIMENTS: Herein, we introduce a quick universal method capable of delivering high-quality exfoliated 2D materials cost-effectively using CTAB-based gelatinous micelles as an exfoliation medium. The approach is devoid of harsh treatment, such as prolonged sonication and heating, and a quick exfoliation of 2D materials is completed using this approach. FINDINGS: We successfully exfoliated four 2D materials (MoS2, Graphene, WS2, and BN) and investigated their morphology, chemical, and crystal structure along with optical and electrochemical properties to probe the quality of the exfoliated product. Results revealed that the proposed method is highly efficient in exfoliating 2D materials in a quick time without causing any significant damage to the mechanical integrity of the exfoliated materials.

Experimental and Statistical Approach to Detect the Corrosion Rate and Influencing Profiles for Enhancing Corrosion Rate of High-Voltage Insulator Materials.

The influence of temperature, pollutant, and pH on the local corrosion rate of insulators installed in industrial, marine, and rural installation sites is investigated based on experimental and statistical investigations. The tensile load test confirms that corroded insulator specimens collected from industrial sites aged more than 10 years represent a minimum fracture load, 19,892 lbs. It was further observed that more than 91.24% and 64.62% corroded insulator specimens suffered from shell break and pin detachment, respectively. The microstructural and XRF analysis reveal that insulator specimens collected from industrial sites (age > 10 years), represented the highest wt% of O (19.2) and lowest wt% of Zn (0.34) among industrial, marine, and rural installation sites. The 3D stationery mechanical simulation reveals that insulator specimens aged > 10 years experienced maximum stress (600 MPa) in the pin-cement interface. Using full two-level factorial designs, temperature, concentration of pollutants, and pH were found significant factors for corrosion rate. The immersion test results further confirm the above-mentioned factors significant for the dissolution behavior of galvanized coating of insulator pin. Following immersion test results, the industrial region shows the highest corrosion rate (5.58-12 µm/year) among all installation sites.

Open-source pipeline for automatic segmentation and microstructural analysis of murine knee subchondral bone.

µCT images are commonly analysed to assess changes in bone density and microstructure in preclinical murine models. Several platforms provide automated analysis of bone microstructural parameters from volumetric regions of interest (ROI). However, segmentation of the regions of subchondral bone to create the volumetric ROIs remains a manual and time-consuming task. This study aimed to develop an automated end-to-end pipeline, combining segmentation and microstructural analysis, to evaluate subchondral bone in the mouse proximal knee. METHODS: A segmented dataset of µCT scans from 62 knees (healthy and arthritic) from 10-week male C57BL/6 mice was used to train a U-Net type architecture to automate segmentation of the subchondral trabecular bone. These segmentations were used in tandem with the original scans as input for microstructural analysis along with thresholded trabecular bone. Manually and U-Net segmented ROIs were fed into two available pipelines for microstructural analysis: the ITKBoneMorphometry library and CTan (SKYSCAN). Outcome parameters were compared between pipelines, including: bone volume (BV), total volume (TV), BV/TV, trabecular number (TbN), trabecular thickness (TbTh), trabecular separation (TbSp), and bone surface density (BSBV). RESULTS: There was good agreement for all bone measures comparing the manual and U-Net pipelines utilizing ITK (R = 0.88-0.98) and CTAn (R = 0.91-0.98). ITK and CTAn showed good agreement for BV, TV, BV/TV, TbTh and BSBV (R = 0.9-0.98). However, limited agreement was seen between TbN (R = 0.73) and TbSb (R = 0.59) due to methodological differences in how spacing is evaluated. Microstructural parameters generated from manual and automatic segmentations showed high correlation across all measures. Using the CTAn pipeline yielded strong R2 values (0.83-0.96) and very strong agreement based on ICC (0.90-0.98). The ITK pipeline yielded similarly high R2 values (0.91-0.96, except for TbN (0.77)), and ICC values (0.88-0.98). The automated segmentations yield lower average values for BV, TV and BV/TV (ranging from 14 % to 6.3 %), but differences were not found to be influenced by the mean ROI values. CONCLUSIONS: This integrated pipeline seamlessly automated both segmentation and quantification of the proximal tibia subchondral bone microstructure. This automated pipeline allows the analysis of large volumes of data, and its open-source nature may enable the standardization of microstructural analysis of trabecular bone across different research groups.

X-ray microtomography applied to mortars: Review of microstructural visualization and parameterization.

The objective of the present work is to review the main applications of X-ray microtomography in the microstructural study of mortars, based on a literature search related to the subject, and to enable the development of more innovative and sustainable mortar formulations. This three-dimensional non-destructive microscopy allows qualitative visualization down to micrometric scales, visualization of the spatial distribution of the interior of samples of objects relatively opaque to visible light and the measurement of quantitative microstructural parameters. Furthermore, the combination of X-ray microtomography with other microstructural and compositional techniques can result in data at different scales of observation. Particularly, in the study of mortars, there are benefits in using this technique to better characterize materials in terms of the spatial structure of pores and other voids, aiding in the formulation of new mortars and in the characterization of mortar behavior, for example, after leaching and carbonation processes. This paper intends to contribute to the discussion of the potentials and drawbacks of this advanced technique, allowing a better characterization of mortars and enabling the development of more innovative and sustainable formulations.

Microstructural evaluation of the brain with advanced magnetic resonance imaging techniques in cases of electrical status epilepticus during sleep (ESES).

Background/aim: The cause and treatment of electrical status epilepticus during sleep (ESES), one of the epileptic encephalopathies of childhood, is unclear. The aim of this study was to evaluate possible microstructural abnormalities in the brain using advanced magnetic resonance imaging (MRI) techniques in ESES patients with and without genetic mutations. Materials and methods: This research comprised 12 ESES patients without structural thalamic lesions (6 with genetic abnormalities and 6 without) and 12 healthy children. Whole-exome sequencing was used for the genetic mutation analysis. Brain MRI data were evaluated using tractus-based spatial statistics, voxel-based morphometry, a local gyrification index, subcortical shape analysis, FreeSurfer volume, and cortical thickness. The data of the groups were compared. Results: The mean age in the control group was 9.05 ± 1.85 years, whereas that in the ESES group was 9.45 ± 2.72 years. Compared to the control group, the ESES patients showed higher mean thalamus diffusivity (p < 0.05). ESES patients with genetic mutations had lower axial diffusivity in the superior longitudinal fasciculus and gray matter volume in the entorhinal region, accumbens area, caudate, putamen, cerebral white matter, and outer cerebellar areas. The superior and middle temporal cortical thickness increased in the ESES patients. Conclusion: This study is important in terms of presenting the microstructural evaluation of the brain in ESES patients with advanced MRI analysis methods as well as comparing patients with and without genetic mutations. These findings may be associated with corticostriatal transmission, ictogenesis, epileptogenesis, neuropsychiatric symptoms, cognitive impairment, and cerebellar involvement in ESES. Expanded case-group studies may help to understand the physiology of the corticothalamic circuitry in its etiopathogenesis and develop secondary therapeutic targets for ESES.