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Purpose: The purpose of this in vivo study was to determine the effects of stress-induced depression and antidepressants on depressive-like behavior, microstructure, and histomorphology of the temporomandibular joint (TMJ) using rats. Methods: Experimentally induced depression in rats was created before being treated with two antidepressants; escitalopram (selective-serotoninreuptake inhibitors) and atomoxetine (norepinephrine-reuptake inhibitors). Micro-computed tomography (Micro-CT) was performed to measure the change in bone volume and bone porosity of the condyle. Further histological evaluation of the condylar cartilage was performed. Results: Micro-CT scanning revealed a decrease in bone volume in the depression group. The bone porosity percentage significantly increased in both the escitalopram and atomoxetine groups compared with the control group and the depression group. Histopathological analysis showed increased thickness of cartilage layers in the depression group. In the atomoxetine group, there was a significant increase in the pre-hypertrophic and hypertrophic layer thickness and cell count, but a significant decrease in proteoglycans. Conclusion: The present study findings indicated the change in TMJ characteristics, especially on the superficial part of the condylar head in the depression group. Concerning the applicability of the different antidepressants, depression with the treatment of atomoxetine has the most disadvantages due to bone porosity and cartilaginous condyle changes. [ABSTRACT FROM AUTHOR]

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica 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.)

Knowledge about air-incorporating additives in concrete can favor civil construction with structures that are lighter and more economical. This study investigated the production of concretes with the addition of 1 to 3% of air-entraining additive via the Micro-CT imaging technique. From the microtomography obtained, it was possible to obtain two-dimensional and three-dimensional images of the analyzed samples. The analysis of these images, using FEI Avizo 9.0 image processing software, allowed for obtaining the volumes of concrete, mortar, voids, and porosities of concrete mortars, in addition to the quantities, shapes, and dimensions of pores (voids) present in the samples. The air contents of the concrete with incorporated air were higher than the reference concrete, directly proportional to the additive contents used, and very close to the mixes with the same additive contents. Both the standard and modified mixes showed an increase in air content as the additive content increased. The specific mass of the concretes decreased as the additive content increased in the standard and modified concretes. As for consistency, the air-incorporated concretes showed greater slumps compared to the reference concrete and increased as the additive content increased, demonstrating the action of the air-incorporating additive in improving workability. [ABSTRACT FROM AUTHOR]

To compare the shaping ability of Procodile and R6 Reziflow instruments used in reciprocating motion in severely curved root canals, assessed with micro‐computed tomography (μCT). Fourteen extracted human mandibular first molars were randomly assigned to two instrumentation techniques (n = 14 mesial root canals): Procodile or R6 Reziflow. For both groups, root canals were prepared to the working length up to a size 25,.06 taper. Molars were virtually divided into apical, middle and coronal thirds and μCT was used to scan all samples pre‐ and post‐root canal. Canal transportation, centring ability, volume, surface area and unprepared area were evaluated. Geometrical parameter changes were compared with preoperative values (one‐way analyses of variance and Tukey multiple comparison post‐hoc test) between groups and Student t‐test within groups (α = 0.05) Significantly less transportation was observed associated with the Procodile technique in the molar's coronal third compared to the R6 Reziflow technique (p <.05). No significant differences in root canal centring ability, volume, surface area and unprepared area were observed. Procodile showed a lower percentage increase of surface area compared to R6 Reziflow (p <.05). The Procodile and R6 Reziflow techniques applied to first molar root canal performed similarly except for the less transportation observed in the coronal third using Procodile. Research Highlights: MicroCT analysis of canal geometry before and after instrumentation revealed that Procodile and R6 Reziflow showed a similar shaping ability to shape curved root canals without substantially modifications of the original tooth anatomy. [ABSTRACT FROM AUTHOR]

Yarn reduction is the core technology of near-net forming conical rotating components. This paper presents the influence of yarn reduction defects on the low-velocity impact (LVI) and compression after impact (CAI) damage mechanism of 3D woven composites. Three kinds of specimens with different yarn reduction defects, no yarn reduction (NO-YR), half row-yarn reduction (HIN-YR), and all row-yarn reduction (AIN-YR), were tested using drop weight LVI and CAI equipment. X-ray micro-computed tomography (Micro-CT) and Digital Image Correlation (DIC) technique were used to identify the damage distribution and damage development of the impact of 3D woven composites. Results indicated that the yarn reduction defects can reduce the LVI and CAI mechanical characteristic values of 3D woven composites. The maximum deflection, permanent deformation, and energy absorption rate of HIN-YR and AIN-YR are about 3% and 6% lower than NO-YR, respectively. At the same impact energy, NO-YR damage was the least and AIN-YR damage was the most severe. Furthermore, compared with AIN-YR, HIN has higher CAI strength. More importantly, yarn reduction changed the damage mechanism of the specimens. The final failure of NO-YR is decided by debonded, whereas that of HIN-YR and AIN-YR are mainly influenced by yarn breakage and delamination. [ABSTRACT FROM AUTHOR]

Background: Osteoporosis is a significant co-morbidity of type 1 diabetes mellitus (DM1) leading to increased fracture risk. Exercise-induced hormone 'irisin' in low dosage has been shown to have a beneficial effect on bone metabolism by increasing osteoblast differentiation and reducing osteoclast maturation, and inhibiting apoptosis and inflammation. We investigated the role of irisin in treating diabetic osteopathy by observing its effect on trabecular bone. Methods: DM1 was induced by intraperitoneal injection of streptozotocin 60 mg/kg body weight. Irisin in low dosage (5 µg twice a week for 6 weeks I/P) was injected into half of the control and 4-week diabetic male Wistar rats. Animals were sacrificed six months after induction of diabetes. The trabecular bone in the femoral head and neck was analyzed using a micro-CT technique. Bone turnover markers were measured using ELISA, Western blot, and RT-PCR techniques. Results: It was found that DM1 deteriorates the trabecular bone microstructure by increasing trabecular separation (Tb-Sp) and decreasing trabecular thickness (Tb-Th), bone volume fraction (BV/TV), and bone mineral density (BMD). Irisin treatment positively affects bone quality by increasing trabecular number p < 0.05 and improves the BMD, Tb-Sp, and BV/TV by 21-28%. The deterioration in bone microarchitecture is mainly attributed to decreased bone formation observed as low osteocalcin and high sclerostin levels in diabetic bone samples p < 0.001. The irisin treatment significantly suppressed the serum and bone sclerostin levels p < 0.001, increased the serum CTX1 levels p < 0.05, and also showed non-significant improvement in osteocalcin levels. Conclusions: This is the first pilot study to our knowledge that shows that a low dose of irisin marginally improves the trabecular bone in DM1 and is an effective peptide in reducing sclerostin levels. [ABSTRACT FROM AUTHOR]

Laser Powder Bed Fusion (LPBF) is considered a promising technology for NiTi intermetallic components production. However, different defects such as near-surface porosity inherent to the process are limiting the standardization and widespread of the technology due to the deterioration of the mechanical properties. In this work, a comprehensive study was implemented to reduce the near-surface porosity by the laser polishing of additively manufactured samples from pre-alloyed NiTi powder by LPBF. Different laser polishing process conditions were employed for the treatment of the near-surface region. Results have shown that the most effective treatment aimed at porosity healing occurs at a laser power of 540 W, a scanning speed of 25 mm/s, a hatch spacing of 200 μm, and a laser spot of 500 μm. The phase identification and martensite-austenite transformation temperatures characterization were carried out before and after the laser polishing of the NiTi samples; the influence of the laser polishing on the functional properties of the material was demonstrated. It was shown that the application of required linear energy density for successful healing of the near-surface porosity leads to the local solutionizing effect. Additionally, electrochemical studies were carried out in Hank's solution and demonstrated that the corrosion resistance was improved after laser polishing. [ABSTRACT FROM AUTHOR]

Copyright of Natural Gas Industry is the property of Natural Gas Industry Journal Agency 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.)

Objective: The objective of this study is to evaluate the occurrence of coronal dentinal micro-cracks after access cavity refinement using high-speed burs and ultrasonic tips by means of micro-computed tomography (micro-CT) analysis. Methods: In this study, 18 mandibular cadaveric incisors were divided into two groups according to the protocol of the preparation of the conventional access cavity. The diamond bur 802 # 12 was used until the perforation of the pulp roof. Then, the Endo-Z bur was used for the group #1 and the ultrasonic tip Start-X # 1 for the group #2 to finish and refine the access cavity. The preparation time of each access cavity has been recorded. The teeth underwent a micro-CT scan before and after the preparation of the access cavity. Fisher's exact test, the Chi-square test, the Kolmogorov–Smirnov test, the Mann–Whitney test, and the Student's test were used for statistical evaluation. Results: The percentage of teeth with new micro-cracks is not significantly different between the two groups (-p-value < 0.5). The number of newly formed micro-cracks and extension size were not significantly different between the two groups. The direction of extension of the micro- cracks was occluso-apical. The average duration of the access cavity is significantly smaller with the Endo-Z system (-p- value < 0.001). The roughness of walls surfaces has no statistically difference between the two groups. Conclusion: The use of ultrasound, although slower, is considered safe in the creation of dentinal micro-cracks, in the preparation of the access cavity. [ABSTRACT FROM AUTHOR]

This study evaluated microleakage from class II cavities filled with bulk-fill composite preheated to different temperatures, applied at different thicknesses, and with different polymerization modes. A total of 60 mesio-occlusal cavity were drilled into the extracted human third molars at 2 mm and 4 mm thickness. Preheated bulk-fill composite resin (Viscalor; VOCO, Germany) was applied to the cavities at 68 °C and 37 °C after the adhesive resin was applied, and cured using standard and high-power light-curing modes of a VALO light-curing unit. An incrementally applied microhybrid composite was used as the control. The teeth were subjected to 2000 cycles of heating to 55 °C and cooling to 5 °C with a 30-s hold time. Then, they were immersed in a 50% silver nitrate solution for 24 h and scanned with micro-computed tomography. Scanned data were processed using the CTAn software. Two (2D) and three (3D) dimensional analyses of leached silver nitrate were performed. The data's normality was assessed using the Shapiro–Wilk test before comparisons using a three-way analysis of variance. In both 2D and 3D analysis, bulk-fill composite resin preheated to 68 °C and applied at 2 mm thickness showed less microleakage. In the 3D analysis, restorations applied at 37 °C and 4 mm thickness in high-power mode showed significantly higher values (p < 0.001). Preheated bulk-fill composite resin can be applied at 68 °C and effectively cured at both 2 mm and 4 mm thickness. [ABSTRACT FROM AUTHOR]

Tracking the fate of therapeutic cell types is important for assessing their safety and efficacy. Bioluminescence imaging (BLI) is an effective cell tracking technique, but poor spatial resolution means it has limited ability to precisely map cells in vivo in 3D. This can be overcome by using a bimodal imaging approach that combines BLI with a technique capable of generating high‐resolution images. Here we compared the effectiveness of combining either multispectral optoacoustic tomography (MSOT) or micro‐computed tomography (micro‐CT) with BLI for tracking the fate of luciferase+ human mesenchymal stromal cells (MSCs) labelled with gold nanorods. Following subcutaneous administration in mice, the MSCs could be readily detected with MSOT but not with micro‐CT. We conclude that MSOT is more sensitive than micro‐CT for tracking gold nanorod‐labelled cells in vivo and depending on the route of administration, can be used effectively with BLI to track MSC fate in mice. [ABSTRACT FROM AUTHOR]

The use of mass spectrometry imaging for crystallinity detection offers improved matrix selectivity and sensitivity over the techniques, such as X-ray microscopy and Raman spectrometry, that are traditionally used with this work. Crystallinity is observed in electrospray laser desorption ionization mass spectrometry imaging (ELDI-MSI) as a high-intensity agglomeration of the analyte in a spatially resolved image. As this is an indirect method of crystallinity detection, confirmation of this method's ability to detect crystallization in amorphous formulations is needed by directly correlating observations of tablet crystallinity by ELDI-MSI to those of an established detection technique. Micro-computed tomography (micro-CT) has the necessary sensitivity for this investigation and is ideal for use in evaluating the correlation with crystallinity detection by ELDI-MSI. In this work, micro-CT followed by ELDI-MSI, in the same location on tablets of amorphous formulations of miconazole spiked with trace levels of crystalline miconazole, were analyzed. Crystals detected by ELDI-MSI as an agglomeration spatially matched with the detected crystals but were chemically unidentified by micro-CT. The results of this correlation study and a conclusion about the effectiveness of ELDI-MSI as a complimentary technique to indirectly detect crystallinity in enabling formations of an amorphous API are presented. [ABSTRACT FROM AUTHOR]

We previously described X-ray histotomography, a high-resolution, non-destructive form of X-ray microtomography (micro-CT) imaging customized for three-dimensional (3D), digital histology, allowing quantitative, volumetric tissue and organismal phenotyping (Ding et al., 2019). Here, we have combined micro-CT with a novel application of ionic silver staining to characterize melanin distribution in whole zebrafish larvae. The resulting images enabled whole-body, computational analyses of regional melanin content and morphology. Normalized micro-CT reconstructions of silver-stained fish consistently reproduced pigment patterns seen by light microscopy, and further allowed direct quantitative comparisons of melanin content across wild-type and mutant samples, including subtle phenotypes not previously noticed. Silver staining of melanin for micro-CT provides proof-of-principle for whole-body, 3D computational phenomic analysis of a specific cell type at cellular resolution, with potential applications in other model organisms and melanocytic neoplasms. Advances such as this in whole-organism, high-resolution phenotyping provide superior context for studying the phenotypic effects of genetic, disease, and environmental variables.

Amniotic eggs are multifunctional structures that enabled early tetrapods to colonize the land millions of years ago, and are now the reproductive mode of over 70% of all terrestrial amniotes. Eggshell morphology is at the core of animal survival, mediating the interactions between embryos and their environment, and has evolved into a massive diversity of forms and functions in modern reptiles. These functions are critical to embryonic survival and may serve as models for new antimicrobial and/or breathable membranes. However, we still lack critical data on the basic structural and functional properties of eggs, particularly of reptiles. Here, we first characterized egg shape, shell thickness, porosity, and mineralization of eggs from 91 reptile species using optical images, scanning electron microscopy, and micro computed tomography, and collected data on nesting ecology from the literature. We then used comparative analyses to test hypotheses on the selective pressures driving their evolution. We hypothesized that eggshell morphology has evolved to protect shells from physical damage and desiccation, and, in support, found a positive relationship between thickness and precipitation, and a negative relationship between porosity and temperature. Although mineralization varied extensively, it was not correlated with nesting ecology variables. Ancestral state reconstructions show thinning and increased porosity over evolutionary time in squamates, but the opposite in turtles and crocodilians. Egg shape, size, porosity and calcification were correlated, suggesting potential structural or developmental tradeoffs. This study provides new data and insights into the morphology and evolution of reptile eggs, and raises numerous questions for additional research.

Microcomputed tomography (micro-CT) is a relatively new modality to investigate mechanical deformations. The purpose of this study was to assess the microgap at the implant-sleeve connection of a new two-piece dental implant with a replaceable sleeve. Materials and Methods: Implants were assembled with 25-degree angulated abutments. Micro-CT was used to assess implant-sleeve connection gaps under the following mechanical conditions: (1) unloading; (2) compressive 10,000 cyclic loading with 400 N; (3) static compressive load of 200 N or 400 N for 24 hours. Results: The mean gap in the unloaded sample was 2.9 ± 0.9 μm. The mean gap difference after cyclic compressive load was 0.3 ± 0.15 μm, demonstrating a negligible effect for the cyclic loading. Under static compressive load, there was no increase in microgap size at 200 N. At 400 N, a significant (P < .05) increase was noted. While the mean values increased by 1.9 μm, the most pronounced significant increase in mean microgap was noted in the direction of force application (5.1 ± 2.14 μm), while a significant decrease in mean microgap (1.2 ± 1.47 μm) was noted on the opposite side. Conclusion: The mechanical behavior of the implant-sleeve connection under static and dynamic loads was found to be within the previously reported range of implant dentistry. [ABSTRACT FROM AUTHOR]

Objectives: To develop and validate a simple approach for building cost-effective imaging phantoms for Cone Beam Computed Tomography (CBCT) using a modified Polyjet additive manufacturing technology where a single material can mimic a range of human soft-tissue radiation attenuation. Materials and Methods: Single material test phantoms using a cubic lattice were designed in 3-Matic 15.0 software . Keeping the individual cubic lattice volume constant, eight different percentage ratio (R) of air: material from 0% to 70% with a 10% increment were assigned to each sample. The phantoms were printed in three materials, namely Vero PureWhite, VeroClear and TangoPlus using Polyjet technology. The CT value analysis, non-contact profile measurement and microCT-based volumetric analysis was performed for all the samples. Results: The printed test phantoms produced a grey value spectrum equivalent to the radiation attenuation of human soft tissues in the range of −757 to +286 HU on CT. The results from dimensional comparison analysis of the printed phantoms with the digital test phantoms using non-contact profile measurement showed a mean accuracy of 99.07 % and that of micro-CT volumetric analysis showed mean volumetric accuracy of 84.80–94.91%. The material and printing costs of developing 24 test phantoms was 83.00 Euro. Conclusions: The study shows that additive manufacturing-guided macrostructure manipulation modifies successfully the radiographic visibility of a material in CBCT imaging with 1 mm3 resolution, helping customization of imaging phantoms.

X-ray computed tomography (CT) is a cardinal tool in clinical practice. It provides cross-sectional images within seconds. The recent introduction of clinical photon-counting CT allowed for an increase in spatial resolution by more than a factor of two resulting in a pixel size in the center of rotation of about 150 µm. This level of spatial resolution is in the order of dedicated preclinical micro-CT systems. However so far, the need for different dedicated clinical and preclinical systems often hinders the rapid translation of early research results to applications in men. This drawback might be overcome by ultra-high resolution (UHR) clinical photon-counting CT unifying preclinical and clinical research capabilities in a single machine. Herein, the prototype of a clinical UHR PCD CT (SOMATOM CounT, Siemens Healthineers, Forchheim, Germany) was used. The system comprises a conventional energy-integrating detector (EID) and a novel photon-counting detector (PCD). While the EID provides a pixel size of 0.6 mm in the centre of rotation, the PCD provides a pixel size of 0.25 mm. Additionally, it provides a quantification of photon energies by sorting them into up to four distinct energy bins. This acquisition of multi-energy data allows for a multitude of applications, e.g. pseudo-monochromatic imaging. In particular, we examine the relation between spatial resolution, image noise and administered radiation dose for a multitude of use-cases. These cases include ultra-high resolution and multi-energy acquisitions of mice administered with a prototype bismuth-based contrast agent (nanoPET Pharma, Berlin, Germany) as well as larger animals and actual patients. The clinical EID provides a spatial resolution of about 9 lp/cm (modulation transfer function at 10%, MTF10%) while UHR allows for the acquisition of images with up to 16 lp/cm allowing for the visualization of all relevant anatomical structures in preclinical and clinical specimen. The spectral capabilities of the system enable a variety of applications previously not available in preclinical research such as pseudo-monochromatic images. Clinical ultra-high resolution photon-counting CT has the potential to unify preclinical and clinical research on a single system enabling versatile imaging of specimens and individuals ranging from mice to man.

Abstract Background A thorough understanding of root and canal anatomy is crucial for successful root canal treatment outcomes. This systematic review aims to explore the published micro-CT studies investigated the anatomy of root and canal system in permanent mandibular first molars. Method An electronic search was performed on Web of science, PubMed, and Scopus. Micro-CT journal studies investigated the root and canal anatomy of permanent double-rooted mandibular first molars were included. Data on study characteristics, objectives of interest, specifications of the studies, and micro-CT specifications were extracted. Risk of bias assessment (ROB) of the included studies was performed using Anatomical Quality Assessment (AQUA) tool. The extracted data were presented in tables and figures to present and synthesise the results. A meta-analysis was performed for the studies related to the prevalence of Vertucci's canal configurations, middle mesial canal (MMC) configurations, and Fan's isthmus types. Results Amongst 1358 identified studies, thirty met the inclusion criteria. In terms of the objectives, the selected studies showed high anatomical variability in mandibular first molars. Twenty-two (73%), 25 (83%), and 12 (40%) of the studies reported the population/ethnicity, micro-CT specifications, and ethical approval, respectively. 28 (93%) studies did not disclose the method of sample size estimation. In only 6 (20%) of the studies, the authors had calibrated the assessment approaches. Mostly, a potential ROB was reported in domain 1 (objective(s) and subject characteristics) and domain 3 (methodology characterization). Whilst, low risk was reported in domains 2 (study design), 4 (descriptive anatomy), and 5 (reporting of results). The overall ROB was reported to be ''moderate'' in the vast majority of the studies (27/30). Meta-analysis results showed high levels of heterogeneity among the studies related to MMCs (I 2 = 86%) and Fan's isthmus (I 2 = 87%). As for the root canal configuration, pooled prevalence showed that Vertucci type IV and type I were the most prevalent in mesial and distal root canals, respectively. Conclusion Based on moderate risk of bias level of evidence, micro-CT studies have shown wide range of qualitative and quantitative data presentations of the roots and canals in mandibular first molars. Protocol and registration. The protocol of this systematic review was prospectively registered in the Open Science Framework database ( https://osf.io ) on 2022–06-20 with the registration number 10.17605/OSF.IO/EZP7K.

Permeability is a key parameter for coalbed methane development. Although the absolute permeability of coal has been extensively studied, wettability and pore structure properties continue to challenge the microscopic description of water-gas flow in coal. For this purpose, we reconstructed the microstructures of low-rank coal using micro-computed tomography (micro-CT) images. Pore geometry and pore-throat parameters are introduced to establish a relationship with absolute permeability. A dual-porosity pore network model is developed to study water-gas displacement under different wetting and pore structure properties. Results show that absolute permeability is significantly affected by pore geometry and can be described using a binary quadratic function of porosity and fractal dimension. Water-gas relative permeability varies significantly and the residual gas saturation is lower; the crossover saturation first decreased and then increased with increasing porosity under hydrophobic conditions. While the water relative permeability is lower and a certain amount of gas is trapped in complex pore-throat networks; the crossover saturation is higher under hydrophilic conditions. Models with large percolating porosity and well-developed pore networks have high displacement efficiency due to low capillary resistance and avoidance of trapping. This work provides a systematic description of absolute permeability and water-gas relative permeability in coal microstructure for enhanced gas recovery.

The properties of steel are affected by the non-metallic inclusions. It is critical to control the morphology of inclusions for producing the high-quality steel. However, due to the morphology of inclusions is complex and diverse, it is difficult to reveal the real morphology of inclusions by using the traditional two-dimensional (2D) observation method, and making it hard to quantitatively analyze the size and morphology of inclusions. In this study, the three-dimensional (3D) morphology of the alumina clusters in steel samples was observed by using the X-ray Micro-CT in the beamline of BL16U2 at Shanghai Synchrotron Radiation Facility (SSRF). Avizo software was used to reconstruct the 3D morphology of the alumina clusters, which intuitively shows the actual morphology of alumina clusters. The accuracy of 2D and 3D observation methods is discussed based on the stereological analysis of individual alumina cluster. A series of parameters were defined to characterize the morphological characteristics of the alumina clusters based the 3D observation. The fractal theory was introduced to quantitatively describe the morphological of alumina clusters. In the current study, the 2D fractal dimension of alumina clusters was determined as 1.64. The complexity of 3D morphology of alumina clusters was analyzed by 3D fractal dimension and shape factor. The current work provides an effective method for quantitative description of the morphology and spatial distribution of inclusions, which provides an important reference for effective control of alumina inclusions.

Additive manufactured light components are desirable for airspace and automobile applications where failure resistance under contact is important. To date, understanding the nature of subsurface damage in contact is still lacking. In this research, we investigated 3D-printed aluminum-silicon (Al-Si) alloys in the lattice structure under a rolling contact condition. Using the microtomography technique, we were able to construct a 3D image of the lattice structure being plastically deformed. Finite element analysis was conducted about the strain and stress on struts of different dimensions. Results showed that morphology dominated the deformation. The significant factors affecting the deformation were the strut aspect ratio, and their relative diameter. When the aspect ratio of a strut is smaller than 0.5, the plastic deformation is distributed in the subsurface region and when it is larger than 0.5, the deformation concentrates on the top layer of struts. This research indicates that the dimensional parameters of lattice structures can be designed for optimization to achieve higher resistance to deformation.

Citrus tristeza virus (CTV) is the most important viral pathogen of citrus. CTV-induced stem pitting negatively impacts grapefruit and sweet orange production. The mechanisms of stem pitting development in CTV-infected citrus remain unclear. This study evaluated the utility of high-resolution CT scanning as a tool to study stem pitting in live citrus material. CT scans were used to easily identify pits based on differences in tissue density. Stem pits were also mapped and modelled three-dimensionally along the length of the stem. Nano-CT scanning proved to be a potentially valuable, non-destructive method for stem pitting characterization in citrus.

The extraction of museum DNA from a unique collection of samples of the “Crocidura pergrisea” species complex, which comprises local endemics of Central and West Asia, allowed us to determine their inter- and intragroup relationships. The first step of this study was the re-evaluation of heavily damaged type specimens of C. armenica via a microcomputed-tomography-based cybertaxonomic approach (CTtax), which enabled a precise description of the species’ morphology; three-dimensional models of the cybertypes were made available through the MorphoBank Repository. We developed the “AProMaDesU” pipeline on the basis of five requirements for micro-CT-based cyber-datasets in relation to mammalian collections. Our second step was a combination of several meticulous approaches to morphological investigation against a background of a cytb-based phylogeny, which helped us to make a taxonomic decision about the status of species of the “pergrisea” group, e.g., C. arispa, C. armenica, and C. serezkyensis, when the morphological results were partly incongruent with the molecular phylogeny. Nevertheless, under two assumptions, our findings preserved a separate species-level status of C. serezkyensis and C. arispa. In addition, we restored the species-level status of C. armenica. This taxonomic decision is based on our morphospace analysis, which revealed unique craniomandibular shape transformations within the rocky shrews that helped them with the transition to a new area of morphospace/trophic niches and consequently separated them from the other analyzed Crocidura groups.

Aortic aneurysms, life-threatening and often undetected until they cause sudden death, occur when the aorta dilates beyond 1.5 times its normal size. This study used ultrasound scans and micro-computed tomography to monitor and measure aortic volume in preclinical settings, comparing it to the well-established measurement using ultrasound scans. The reproducibility of measurements was also examined for intra- and inter-observer variability, with both modalities used on 8-week-old C57BL6 mice. For inter-observer variability, the μCT (micro-computed tomography) measurements for the thoracic, abdominal, and whole aorta between observers were highly consistent, showing a strong positive correlation (R2 = 0.80, 0.80, 0.95, respectively) and no significant variability (p-value: 0.03, 0.03, 0.004, respectively). The intra-observer variability for thoracic, abdominal, and whole aorta scans demonstrated a significant positive correlation (R2 = 0.99, 0.96, 0.87, respectively) and low variability (p-values = 0.0004, 0.002, 0.01, respectively). The comparison between μCT and USS (ultrasound) in the suprarenal and infrarenal aorta showed no significant difference (p-value = 0.20 and 0.21, respectively). μCT provided significantly higher aortic volume measurements compared to USS. The reproducibility of USS and μCT measurements was consistent, showing minimal variance among observers. These findings suggest that μCT is a reliable alternative for comprehensive aortic phenotyping, consistent with clinical findings in human data.

Purpose: To evaluate interfacial gap and fracture resistance of endodontically treated maxillary premolars, restored with different glass-fiber reinforced materials. Materials and Methods: Eighty-four extracted intact premolars were endodontically treated and MOD cavities prepared. Specimens were divided into 7 groups (n = 12 for each) as follows: sound teeth (G1); no restoration (G2); direct composite restoration with fiber-reinforced composite (everX Posterior GC) (G3); direct composite restoration (Filtek Supreme XTE, 3M Oral Care; "FSXTE") (G4); a horizontal layer of high-viscosity flowable composite (G-ænial Flow, GC) was placed on the pulp chamber floor, 10 mm x 3 mm glass fibers (everStick NET, GC) were inserted into the cavity (G5); same procedure as in group 5 except the direct restoration was made incrementally with FSXTE (3M Oral Care) (G6); composite overlays were placed (G7). Specimens were scanned with micro-CT to evaluate 3D interfacial gaps before and after chewing simulation using Mimics software to calculate voids between restoration and tooth (dentin and enamel). These data (in mm³) were collected for statistical analysis. Thereafter, specimens were loaded to fracture using a universal testing machine. Maximum breaking loads were recorded in Newton (N). The data obtained were analyzed using two-way ANOVA and post-hoc Tukey's test (p < 0.05). Results: ANOVA showed that horizontal glass-fiber insertions statistically significantly reduced interfacial gaps after chewing simulation. No differences in fracture resistance were found between Filtek Supreme XTE and everX Posterior; moreover, glass-fiber insertion did not significantly improve fracture resistance in either case. Composite overlays achieved significantly better fracture toughness than did direct restorations. Conclusions: For the direct restoration of endodontically treated premolars, the insertion of glass fibers into direct composite restorations was unable to guarantee a significant increase in the fracture resistance or a significant change in the fracture pattern. However, it significantly reduced interfacial gap volume after cycling fatigue. [ABSTRACT FROM AUTHOR]

ABSTRACT: Eggshell translucency, an externally observable feature, can influence consumer purchase intentions. The eggshell quality often deteriorates in aging laying hens, leading to increased eggshell translucency. Eggs exchange water vapor through the pores. It is commonly believed that the moisture remaining in the mastoid space contributes to translucent egg formation. However, the precise mechanisms underlying eggshell translucency require further structural investigations. This study aimed to explore the 3-dimensional microstructure of eggshells using micro-computed tomography (micro-CT) to provide insights into the microstructural basis of eggshell translucency. The results revealed that the ratio of pore volume to mastoid space volume was significantly higher in the high-translucency (TH) group than that in the low-translucency (TL) group (P < 0.01); however, the ratio of mastoid space to eggshell volume showed no significant difference. Additionally, measurements of the individual pore morphological features showed that the roundness of the pores in the TH group was significantly higher than that in the TL group, whereas the flatness of the pores in the TH group was significantly lower (P = 0.01). Eggshell porosity directly reflects the water vapor exchange capacity of eggshells, with the TL group exhibiting significantly higher eggshell porosity compared to the TH group (P = 0.02). In conclusion, based on observations of the 3-dimensional microstructure of eggshells, this study elucidated how the volume and morphological characteristics of pores influence the water vapor exchange capacity of eggshells, resulting in eggshell translucency.

Permanent tooth avulsion is a common but extremely serious dental injury that can negatively affect both economic output and lifestyle. Even though it is not a disease, no one is ever completely safe from the possibility of suffering from these disastrous injuries. Dental implants play a vital role in the treatment of such injuries (tooth loss). This work was focused on to find the effects of two different platform switched abutment-implant assembly on hard tissues (Cortical and cancellous) bone. Materialized Mimics Medical Software was used for processing clinical imaging (CBCT) data of mandibular bone and micro-CT data of implant (5.5 × 9.5 mm), Abutments (Pt. sw. I and Pt. sw. II) and final 3D model of all parts were obtained by Fusion 360 CAD software and implanted into a right mandible bone block. Implant-Abutment with different switching assembly as platform switched-I (Pt. Sw. I) Ø5.5-mm implant and Ø3.8-mm abutment and the platform switched-II (Pt. Sw. II) Ø5.5-mm implant and Ø4.5-mm abutment were compared. Each model was subjected to 50 N, 100 N and 150 N longitudinal and lateral loads at occlusal surface of the abutment to evaluate the mechanical parameters. ANSYS 2020R1 was used to conduct the computational analysis. Mechanical characteristics such as von-Mises stresses and total deformation were measured in the hard tissues using finite element modelling. Under the application of different loads the cancellous bone experiences maximum von misses stress 4.7 MPa and 5.4 MPa for Pt. Sw. I and Pt. Sw. II respectively under longitudinal load and 7.4 MPa and 8.7 MPa for Pt. Sw. I and Pt. Sw. II respectively under lateral load. Similar trends were observed for cortical bone. While maximum total deformation of 2.1 µm (Pt. Sw. I) and 2.2 µm (Pt. Sw. II) under longitudinal load and 4.4 µm and 4.6 µm in cancellous bone and cortical bone under longitudinal load and 4.4 µm (Pt. Sw. I) and 4.6 µm (Pt. Sw. II) under lateral load in cancellous and 7.5 µm (Pt. Sw. I) and 8 µm (Pt. Sw. II) in cortical bone were recorded. The analysis may help to prevent the progression of marginal bone loss (MBL) because lower results for these variables indicated for higher platform switching in marginal bone. The findings of computational frameworks can help clinicians and other medical professionals make more informed decisions when selecting a treatment strategy from the many options available.

The underwater sound absorption material for submarines should fulfill the demand for remarkable performance in medium-low frequency sound absorption at low thicknesses. Hence, in this paper, the innovative “filled-microperforated plate-like” (F-MPPL) structure was introduced to the hollow microballoons filled underwater sound absorption composite (HBF composite) using the tailor-made 3D spacer fabric. The test results show remarkable mechanical properties with a compression strength and compression modulus of 2256 KPa and 14.6 MPa for the new type of F-MPPL composite, respectively. In addition, the peak sound absorption coefficient of the F-MPPL composite reaches 0.77 at just 7.5 mm thickness based on the resonant sound absorption characteristic introduced by the F-MPPL structure. Moreover, the study investigated the effects of seawater aging on the F-MPPL composite and found that while there was a decrease in compression strength and average sound absorption coefficient, the degradation of the F-MPPL composite was significantly smaller than the HBF composite due to the inhibitory effect of spacer yarns on pore expansion. Finally, this study proposed the method of using compression strength to predict the long-term life of the F-MPPL composite under seawater aging, and a 60% retention rate after 20 months was displayed.

Abstract Spiders evolved a distinctive sperm transfer system, with the male copulatory organs located on the tarsus of the pedipalps. In entelegyne spiders, these organs are usually very complex and consist of various sclerites that not only allow the transfer of the sperm themselves but also provide a mechanical interlock between the male and female genitalia. This interlocking can also involve elements that are not part of the copulatory organ such as the retrolateral tibial apophysis (RTA)—a characteristic of the most diverse group of spiders (RTA clade). The RTA is frequently used for primary locking i.e., the first mechanical engagement between male and female genitalia. Despite its functional importance, some diverse spider lineages have lost the RTA, but evolved an apophysis on the femur instead. It can be hypothesized that this femoral apophysis is a functional surrogate of the RTA during primary locking or possibly serves another function, such as self‐bracing, which involves mechanical interaction between male genital structures themselves to stabilize the inserted pedipalp. We tested these hypotheses using ghost spiders of the genus Josa (Anyphaenidae). Our micro‐computed tomography data of cryofixed mating pairs show that the primary locking occurs through elements of the copulatory organ itself and that the femoral apophysis does not contact the female genitalia, but hooks to a projection of the copulatory bulb, representing a newly documented self‐bracing mechanism for entelegyne spiders. Additionally, we show that the femoral self‐bracing apophysis is rather uniform within the genus Josa. This is in contrast to the male genital structures that interact with the female, indicating that the male genital structures of Josa are subject to different selective regimes.

Background Osteoporosis is a significant co-morbidity of type 1 diabetes mellitus (DM1) leading to increased fracture risk. Exercise-induced hormone ‘irisin’ in low dosage has been shown to have a beneficial effect on bone metabolism by increasing osteoblast differentiation and reducing osteoclast maturation, and inhibiting apoptosis and inflammation. We investigated the role of irisin in treating diabetic osteopathy by observing its effect on trabecular bone. Methods DM1 was induced by intraperitoneal injection of streptozotocin 60 mg/kg body weight. Irisin in low dosage (5 µg twice a week for 6 weeks I/P) was injected into half of the control and 4-week diabetic male Wistar rats. Animals were sacrificed six months after induction of diabetes. The trabecular bone in the femoral head and neck was analyzed using a micro-CT technique. Bone turnover markers were measured using ELISA, Western blot, and RT-PCR techniques. Results It was found that DM1 deteriorates the trabecular bone microstructure by increasing trabecular separation (Tb-Sp) and decreasing trabecular thickness (Tb-Th), bone volume fraction (BV/TV), and bone mineral density (BMD). Irisin treatment positively affects bone quality by increasing trabecular number p < 0.05 and improves the BMD, Tb-Sp, and BV/TV by 21–28%. The deterioration in bone microarchitecture is mainly attributed to decreased bone formation observed as low osteocalcin and high sclerostin levels in diabetic bone samples p < 0.001. The irisin treatment significantly suppressed the serum and bone sclerostin levels p < 0.001, increased the serum CTX1 levels p < 0.05, and also showed non-significant improvement in osteocalcin levels. Conclusions This is the first pilot study to our knowledge that shows that a low dose of irisin marginally improves the trabecular bone in DM1 and is an effective peptide in reducing sclerostin levels.

Abstract Leptin an adipokine with potent effects on energy balance and body weight plays an important role in defining bone architecture in growing mammals. However, major changes in body weight can also influence morphology of trabecular and cortical bone. Therefore, we examined the impact of leptin deficiency on tibia and vertebral body 3D bone architecture independent of changes in body weight. Furthermore, advances in computational 3D image analysis suggest that average morphological values may mask regional specific differences in trabecular bone thickness. The study utilized leptin‐deficient Ob/Ob mice (n = 8) weight‐paired to C57BL/6 (C57) control mice (n = 8) which were split into either lean or obese groups for 24 ± 2 weeks. Whole tibias and L3 vertebrae were fixed before high resolution microcomputed tomography (μCT) scanning was performed. Leptin deficiency independent of body weight reduced tibia cortical bone volume, trabecular bone volume/tissue volume, number, and mineral density. Mean tibia trabecular thickness showed no significant differences between all groups; however, significant changes in trabecular thickness were found when analyzed by region. This study demonstrates that leptin deficiency significantly impacts tibia and vertebral body trabecular and cortical bone 3D architecture independent of changes in body weight.

Clay-rich flocculated suspended sediments are an important constituent of estuarine and coastal systems globally. They are responsible for the host, movement and deposition of a variety of pollutants, contaminants and sediment itself. Accurate modelling of the movement of these sediments is crucial for a number of industries including fisheries, aquaculture, shipping and waste management. This requires an accurate and reliable measurements of the physical properties of flocs and their behaviour. Porosity is a key element in floc structures, and this research provides updated 3D quantified porosity and pore space morphological data in relation to influences on floc settling behaviour. We report the questionable relationship between floc size and settling velocity, and explore alternative influences such as floc composition, porosity and pore morphology. These outcomes suggest that a shift in focus from floc size to a combination of factors is necessitated to understand the complex movement behaviour of flocculated suspended sediments.

Objectives: The purpose of this study was to survey the prevalence of C-shaped root canal system in mandibular first premolar in Chinese population by reading Cone-beam computed tomography (CBCT) images and to analyze its anatomical characteristics by CBCT and Micro–computed tomography (Micro-CT). Methods and materials: The prevalence and the morphologic features of C-shaped root canal system were evaluated by observing CBCT images of 760 patients (1520 mandibular first premolars). 66 mandibular first premolars with C-shaped root canal system were scanned by Micro-CT. The morphologic features including radicular groove, C-shaped root canal categories in the cross-sections and in the 3D models, accessory and connecting canals, apical foramina and accessory foramina, were analyzed using image software. Results: C-shaped root canal system was identified in 16.9% of mandibular first premolars. The minimum mesial wall thickness most commonly occurred at the lingual site (69.7%). Regarding to the cross-sectional classification, the maximum was C2 (41.5%). In the 3D classification, the most common was S (34.8%). Accessory canals were observed in 36.4% of the samples and occurred mostly in the middle and apical regions. 42.4% samples had 1–3 variable connecting canals, and 40.9% samples had only one apical foramen. Conclusions: The incidence of C-shaped root canal system in mandibular first premolars was 16.9% in the Chinese population. The anatomy was very complex and variable, mostly distributed in the middle and apical regions of the root canal. The mesial wall of C-shaped canal was extremely thin on the lingual side. [ABSTRACT FROM AUTHOR]

Copyright of Hungarian Medical Journal / Orvosi Hetilap is the property of Akademiai Kiado 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.)

Frost weathering is a key mechanism of rock failure in periglacial environments and landscape evolution. At high alpine rockwalls, freezing regimes are a combination of diurnal and sustained seasonal freeze-thaw regimes and both influence frost cracking processes. Recent studies have tested the effectiveness of freeze-thaw cycles by measuring weathering proxies for frost damage in low-strength and grain-supported pore space rocks, but detecting frost damage in low-porosity and crackdominated alpine rocks is challenging due to small changes in these proxies that are close to the detection limit. Consequently, the assessment of frost weathering efficacy in alpine rocks may be flawed. In order to fully determine the effectiveness of both freezing regimes, freeze-thaw cycles and sustained freezing were simulated on low-porosity high-strength Dachstein limestone under temperature and moisture conditions that reflect those found in high alpine rockwalls. Frost-induced rock damage was uniquely quantified by combining X-ray computed micro-tomography (µCT), acoustic emission (AE) monitoring and frost cracking modelling. To differentiate between potential mechanisms of rock damage, thermal- and ice-induced stresses were simulated and compared with AE activity. µCT combined with AE data revealed frost damage on low-porosity alpine rocks with crack growth along pre-existing cracks with magnitudes dependent on the initial crack density. It was observed that diurnal freeze-thaw cycles have a higher frost cracking efficacy on alpine rocks compared to a seasonal sustained freezing regime. On north-facing high alpine rockfaces, the number of freeze-thaw cycles and the duration of sustained freezing conditions vary with elevation and seasonal climate. The experimental results establish a link between frost damage and elevation-dependent rockwall erosion rates, which has implications for hazard prediction in mountainous areas under a changing climate. [ABSTRACT FROM AUTHOR]

Histological and naked-eye dissections are frequently used to investigate human anatomy. However, limitations of conventional methods include tissue damage and difficulty in observing structures, rendering findings limited. Micro-computed tomography (micro-CT) allows for a three-dimensional observation with whole-mount staining for contrast enhancement. A precise anatomical understanding of the larynx is essential for both the medical and surgical fields; however, the larynx is difficult to dissect because of its minuscule and complex structures. Therefore, we aimed to clarify the detailed anatomy of the larynx using micro-CT. The study was conducted on twelve specimens of cadavers using Lugol-based-contrast micro-CT. Using Lugol-micro-CT, relevant information on human structures was obtained. Consequently, we successfully employed the Lugol-micro-CT technique in the analysis of specific human soft tissue structures that are challenging to analyze using conventional methods. [ABSTRACT FROM AUTHOR]

Osteodentin is a dominant mineralized collagenous tissue in the teeth of many fishes, with structural and histological characteristics resembling those of bone. Osteodentin, like bone, comprises osteons as basic structural building blocks, however, it lacks the osteocytes and the lacuno-canalicular network (LCN), which are known to play critical roles in controlling the mineralization of the collagenous matrix in bone. Although numerous vascular canals exist in osteodentin, their role in tooth maturation and the matrix mineralization process remain poorly understood. Here, high resolution micro-computed tomography (micro-CT) and focused ion beam-scanning electron microscopy (FIB-SEM) were used to obtain 3D structural information of osteodentin in shark teeth at multiple scales. We observed a complex 3D network of primary canals with a diameter ranging from ∼10 µm to ∼120 µm, where the canals are surrounded by osteon-like concentric layers of lamellae, with 'interosteonal' tissue intervening between neighboring osteons. In addition, numerous hierarchically branched secondary canals extended radially from the primary canals into the interosteonal tissue, decreasing in diameter from ∼10 µm to hundreds of nanometers. Interestingly, the mineralization degree increases from the periphery of primary canals into the interosteonal tissue, suggesting that mineralization begins in the interosteonal tissue. Correspondingly, the hardness and elastic modulus of the interosteonal tissue are higher than those of the osteonal tissue. These results demonstrate that the 3D hierarchical canal network is positioned to play a critical role in controlling the gradient mineralization of osteodentin, also providing valuable insight into the formation of mineralized collagenous tissue without osteocytes and LCN. Bone is a composite material with versatile mechanical properties. Osteocytes and their lacuno-canalicular network (LCN) are known to play critical roles during formation of human bone. However, the bone and osteodentin of many fishes, although lacking osteocytes and LCN, exhibit similar osteon-like structure and mechanical functions. Here, using various high resolution 3D characterization techniques, we reveal that the 3D network of primary canals and numerous hierarchically branched secondary canals correlate with the mineralization gradient and micromechanical properties of osteonal and interosteonal tissues of shark tooth osteodentin. This work significantly improves our understanding of the construction of bone-like mineralized tissue without osteocytes and LCN, and provides inspirations for the fabrication of functional materials with hierarchical structure. [Display omitted] [ABSTRACT FROM AUTHOR]

Background: Phosphine (PH3) resistance in stored grain insect pests poses a significant challenge to effective pest control strategies worldwide. This study delved into understanding PH3-resistant mechanism, with the objective of informing robust and sustainable pest management strategies that could mitigate the impacts of PH3 resistance. Results: In this regard, the transcriptomic analysis identified 23 genes associated with chitin synthesis and cuticle formation, which showed significant expression in PH3-resistant (R) strains compared to susceptible strains. Micro-computed tomography (Micro-CT) revealed an extended and tighter cuticular structure in the PH3-R Tribolium castaneum than PH3-susceptible strains but with no changes in the cuticle thickness. This altered cuticle structure may reduce PH3 penetration through cuticles rather than completely closing spiracles during fumigation. It is also hypothesized to prevent water loss from the insect body, as water production decreased in PH3-R T. castaneum due to the down-regulation of the electron transport chain function. Validation of several chitin synthesis gene expression levels revealed consistent results with those of transcriptomic analysis. Conclusion: Overall, integrating physical treatments using synthetic amorphous silicates, water absorbents, and cuticle-damaging materials during PH3 fumigation is recommended for its prolonged and controlled usage in the field. [ABSTRACT FROM AUTHOR]

Premise: Imaging technologies that capture three‐dimensional (3D) variation in floral morphology at micro‐ and nano‐resolutions are increasingly accessible. In herkogamous flowers, such as those of Theobroma cacao, structural barriers between anthers and stigmas represent bottlenecks that restrict pollinator size and access to reproductive organs. To study the unresolved pollination biology of cacao, we present a novel application of micro‐computed tomography (micro‐CT) using floral dimensions to quantify pollinator functional size limits. Methods: We generated micro‐CT data sets from field‐collected flowers and museum specimens of potential pollinators. To compare floral variation, we used 3D Slicer to place landmarks on the surface models and performed a geometric morphometric (GMM) analysis using geomorph R. We identified the petal side door (an opening between the petal hoods and filament) as the main bottleneck for pollinator access. We compared its mean dimensions with proposed pollinators to identify viable candidates. Results: We identified three levels of likelihood for putative pollinators based on the number of morphological (body) dimensions that fit through the petal side door. We also found floral reward microstructures whose presence and location were previously unclear. Discussion: Using micro‐CT and GMM to study the 3D pollination biology of cacao provides new evidence for predicting unknown pollinators. Incorporating geometry and floral rewards will strengthen plant–pollinator trait matching models for cacao and other species. [ABSTRACT FROM AUTHOR]

3D printing (3DP) technology is a groundbreaking technology that can offer valuable insight into rock characterization and theoretical model verification due to its specimen reproducibility and unprecedented flexibility in manufacturing various structural shapes. Previous studies have explored the effect of printing direction on the mechanical properties of 3D-printed rocks, but the underlying cause of macroscopic mechanical anisotropy in 3D-printed gypsum rocks remains unclear. In this study, the effect of the movement direction of the printer head and bedding plane on macroscopic mechanical behavior and failure modes of 3D printed gypsum rocks were investigated. Uniaxial compression tests were conducted to investigate the mechanical properties of 3D-printed gypsum rocks. Along with the mechanical studies, the composition change of the raw powder before and after printing was studied based on particle size diameter (PSD), x-ray diffraction (XRD), and thermogravimetric differential thermal analysis (TG–DTA) experiments. Furthermore, Micro-CT imaging was conducted to investigate the microstructural characteristics of 3D-printed rocks (e.g. pore size, pore shape, and pore anisotropy). The results indicated that 3DP gypsum specimens printed on the yoz plane, which were only affected by the bedding direction, exhibited the lowest strength and mechanical anisotropy. In contrast, specimens printed on the xoy plane, influenced solely by the movement direction of printer head, showed the highest strength. Specimens printed on the xoz plane displayed the greatest mechanical anisotropy due to the joint effect of the bedding direction and the movement direction of the printer head. In terms of strength and mechanical anisotropic properties of 3D-printed specimens, the movement of the printer head was found to be more significant than the bedding direction, whereas the bedding direction was more crucial for peak strain. As for the failure mode, most of the 3D-printed specimens failed by shear failure of which the bedding planes played an important role in the specimens with small inclined angles. Highlights: This study investigated the effect of the movement direction of the printer head and bedding planes on mechanical anisotropy and the failure mode of 3DP gypsum rocks. Three types of experiments were conducted to enhance the understanding of how material composition and microstructure impact the macroscopic mechanical response of 3DP gypsum rocks. Micro-CT scanning tests were performed to reveal the failure mode and microstructural characteristics of 3D printed gypsum rocks. [ABSTRACT FROM AUTHOR]

Articular surface irregularities are often observed in collapsed femoral heads with osteonecrosis, while the effects of the degree of collapse on the articular surface are poorly understood. We first macroscopically assessed the articular surface irregularities on 2‐mm coronal slices obtained using high‐resolution microcomputed tomography of 76 surgically resected femoral heads with osteonecrosis. These irregularities were observed in 68/76 femoral heads, mainly at the lateral boundary of the necrotic region. The mean degree of collapse was significantly larger for femoral heads with articular surface irregularities than for those without (p < 0.0001). Receiver operating characteristic analysis showed that the cutoff value for the degree of collapse in femoral heads with articular surface irregularities at the lateral boundary was 1.1 mm. Next, for femoral heads with <3‐mm collapse (n = 28), articular surface irregularities were quantitatively assessed based on the number of automatically counted negative curvature points. Quantitative evaluation showed that the degree of collapse was positively correlated with the presence of articular surface irregularities (r = 0.95, p < 0.0001). Histological examination of articular cartilage above the necrotic region (n = 8) revealed cell necrosis in the calcified layer and abnormal cellular arrangement in the deep and middle layers. In conclusion, articular surface irregularities of the necrotic femoral head depended on the degree of collapse, and articular cartilage was already altered even in the absence of macroscopically determined gross irregularities. [ABSTRACT FROM AUTHOR]

Trabecular structures in vertebral bodies are unequally distributed in the cervical, thoracic and lumbar spine, and also within individual vertebrae. Knowledge of the microstructure of these entities could influence our comprehension and treatment of osteoporotic fractures, and even surgical procedures. Appropriate investigations may clarify the pathomechanisms of various osteoporotic fractures (fish, wedge-shaped, and flat vertebrae). We obtained three cancellous bone cylinders from the centers and margins of cervical vertebra 3 to lumbar vertebra 5, and investigated these in regard of bone volume fraction, trabecular thickness, separation, trabecular number, trabecular bone pattern factor, connectivity density, and degree of anisotropy. Using a Jamshidi needle®, we obtained samples from three quadrants (QI: right-sided edge, QII: central, QIII: left-sided edge) of 242 prepared vertebrae, and investigated these on a micro-CT device. In all, 726 bone samples were taken from eleven body donors. Bone volume fraction, trabecular thickness, and the degree of anisotropy were significantly lower in QII than in QI and QIII. Trabecular pattern factor, however, was significantly higher in QII than in QI and QIII. The results helped to explain fish vertebrae. Wedge fractures and flat vertebrae are most likely caused by the complex destruction of trabecular and cortical structures. The higher bone volume fraction in the cervical spine compared to the thoracic and lumbar spine accounts for the small number of fractures in the cervical spine. The marked trabecular pattern factor in the center of thoracic and lumbar vertebrae could be a reason for the surgeon to use different screw designs for individual vertebrae. [ABSTRACT FROM AUTHOR]

This study evaluated the interfacial integrity of deep (6 mm) Class-II (OM/OD) restorations placed using different bulk-fill resin composites [Filtek™ Bulk Fill Flowable Restorative (BF) and Filtek™ Bulk Fill Posterior Restorative (BP) (3M ESPE, St. Paul, MN, USA)] of different increment thicknesses (2 or 4 mm). BP was used for capping in all cases, while Filtek™ Z250 Universal Restorative (3M ESPE) was used as the control material. Interfacial debonding was measured during curing through acoustic emission (AE), followed by image analysis using micro-computed tomography and scanning electron microscopy. Microhardness testing was also conducted to assess degree of conversion. Depth of cure was adequate in all restorations. Specimens with 4-mm thick first increment of BF, which had a higher shrinkage strain, produced most AE events and debonding. Thus, bulk filling of deep cavities using bulk-fill resin composites with a high shrinkage strain should be avoided. [ABSTRACT FROM AUTHOR]

The number of new species described of the genus Terebellides Sars, 1835 (Annelida, Trichobranchidae) in the eastern Atlantic Ocean has greatly increased in the last years. Eleven of these species, all originally described in NE Atlantic Ocean, from the Barents Sea to the Gulf of Guinea, have been studied using micro-computed tomography (micro-CT) thus revealing interspecific differences in several elements of the internal anatomy such as the proportion between stomach regions and size of nephridia, and in the number of lamellae in the digestive gland. Two stomach morphotypes have been distinguished regarding differences in relative length between regions, as well as two morphotypes of nephridia according to their size and wall thickness, and four types of the digestive gland regarding their number of lamellae. Differences in nephridia sizes is the only character apparently related to the geographic distribution of species (i.e. NE Atlantic vs. Gulf of Guinea) but examination of more taxa is needed. A third distinct region was distinguished in the stomach, named here as mid stomach, that differs from the fore and hind stomach in epithelia thickness and by lacking connective muscular sheath. The potential of the micro-CT technique in the search for internal anatomical characters with taxonomic value is discussed. [ABSTRACT FROM AUTHOR]

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica 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.)