μCT Scans Research Articles

Effects of adenovirus-mediated knockdown of IRAK4 on synovitis in the osteoarthritis rabbit model

BackgroundThe use of interleukin-1 receptor-associated kinase 4 (IRAK4) inhibitor as a treatment for the inflammatory joint disease is a promising method. However, its underlying mechanism in osteoarthritis (OA) remains unclear. The purpose of this study is to look into the effects of adenovirus-mediated knockdown of IRAK4 on synovitis in the OA rabbit model.MethodsAd-shIRAK4 was injected two weeks after anterior cruciate ligament resection. Six weeks later, the rabbits were killed. The expression of IRAK4, TNFR-associated factor 6(TRAF6), TGF-activated kinase 1(TAK1), p-IKB kinase (p-IKK), p-nuclear factor kappa-B (p-NFκB), p38, and p-p38 in the synovial membrane was detected by western blot, qRT-PCR, and immunohistochemistry analysis. Immunohistochemistry was to detect the expression of IRAK4 proteins in articular cartilage. H&E staining was to assess the pathological changes of synovium and cartilage. The levels of interleukin (IL)-1β, tumor necrosis factor-α(TNF-α), and MMP-13 in the synovial fluid were measured by ELISA. X-ray and micro-computerized tomography (μCT) scans were used to assess knee joint conditions and microstructure of subchondral bone.ResultsIRAK4 expression levels in synovial tissues of the OA model group exhibited a significant upward trend. Ad-shIRAK4 significantly reduced IRAK4 mRNA expression in synovium tissues. Notably, Ad-shIRAK4 suppressed the Toll-like receptor/interleukin-1 receptor (TLR/IL-1R) signaling. In addition, in the Ad-shIRAK4 treatment group, we can see less inflammatory cell infiltration and reduced hyperplasia and angiogenesis. The levels of IL-1β, TNF-α, and MMP-13 in the synovial fluid in the OA model group were significantly higher than that in the control group, which were reduced by Ad-shIRAK4 treatment. Finally, Results of HE stains, immunohistochemistry, and μCT showed that Ad-shIRAK4 treatment has a protective effect on cartilage damage.ConclusionsIRAK4 is significantly upregulated in the synovium from the osteoarthritis rabbit model. In addition, Ad-shIRAK4 reduced the expression of IRAK4 and suppressed TLR/IL-1R signaling in the synovium from the osteoarthritis rabbit model. Ad-shIRAK4 could alleviate synovitis and cartilage degradation in the osteoarthritis rabbit model, and thus alleviate the symptoms of OA and prevent the progression of OA.Graphical abstract

A Novel Approach to the Holistic 3D Characterization of Weld Seams-Paving the Way for Deep Learning-Based Process Monitoring.

In an industrial environment, the quality assurance of weld seams requires extensive efforts. The most commonly used methods for that are expensive and time-consuming destructive tests, since quality assurance procedures are difficult to integrate into production processes. Beyond that, available test methods allow only the assessment of a very limited set of characteristics. They are either suitable for determining selected geometric features or for locating and evaluating internal seam defects. The presented work describes an evaluation methodology based on microfocus X-ray computed tomography scans (µCT scans) which enable the 3D characterization of weld seams, including internal defects such as cracks and pores. A 3D representation of the weld contour, i.e., the complete geometry of the joint area in the component with all quality-relevant geometric criteria, is an unprecedented novelty. Both the dimensions of the weld seam and internal defects can be revealed, quantified with a resolution down to a few micrometers and precisely assigned to the welded component. On the basis of the methodology developed within the framework of this study, the results of the scans performed on the alloy AA 2219 can be transferred to other aluminum alloys. In this way, the data evaluation framework can be used to obtain extensive reference data for the calibration and validation of inline process monitoring systems employing Deep Learning-based data processing in the scope of subsequent work.

Predicting the mechanical behavior of a polypropylene-based nonwoven using 3D microstructural simulation

Based on filtration simulations, virtual filter media development is used to design new nonwoven microstructures with increased filtration performance. However, the processability in the subsequent manufacturing processes of these new designs is not guaranteed. The ability to predict the mechanical properties of the new designs is crucial to predict their processability. This paper introduces a microstructural simulation model based on micro-computed tomography scans (µCT scans) to predict the three-dimensional elastic-plastic behavior of nonwoven filter media with polypropylene fibers. A microstructural analysis is performed to investigate the requirements of a representative volume element (RVE). Digital twins of the µCT scans are modeled based on the microstructural analysis. The results of an RVE convergence study serve to corroborate the existence of RVEs for this kind of material. Microstructural simulations for the load cases of tension, compression, and shear in all three spatial directions are performed on µCT scans and digital twins. The calculations are validated using the results of an extensive 3D material testing program. The distinct deformation mechanisms under the load cases of tension, compression, and shear in the machine direction, cross direction, and z-direction are discussed. Finally, the results show the dependency of the effective elastic-plastic deformation behavior on a small number of selected microstructural parameters. This dependency enables the usage of digital twins to predict the deformation behavior of virtual microstructure designs.

Plant species and plant neighbor identity affect associations between plant assimilated C inputs and soil pores

Greater plant diversity is known to facilitate soil C gains, yet the exact mechanisms of this effect are still under intensive discussion. Whether a plant grows in monoculture or in a multi-species mixture can affect allocation of plant assimilates, belowground exudation, and microbial stimulation. The goal of this study was to examine the effects of inter-cropping on a previously overlooked aspect of plant-soil interactions, namely, on locations where plant assimilated C is allocated within the soil pore system and its subsequent fate in relation to soil pore size distributions. The soil for the study originated from a greenhouse experiment with switchgrass (Panicum virgatum L.) (var. Cave'n'Rock) (SW), big bluestem (Andropogon gerardii Vitman) (BB), and wild bergamot (Monarda fistulosa L.) (WB) grown in monocultures and in inter-cropped pairs and subjected to species specific 13C pulse labeling (Kravchenko et al., 2021). Intact soil cores (8 mm Ø) were collected from the experimental pots, subjected to a short-term (10 day) incubation, X-ray computed micro-tomography (µCT) scanning, and soil 13C micro-sampling “geo-referenced” to µCT images. Results indicated that in the plant systems with demonstrated interplant C transfer soil 13C was positively correlated with < 10 µm Ø pores immediately after plant termination and with 20–80 µm Ø pores after the incubation. In the systems without marked interplant C transfer soil, 13C was positively correlated with 20–30 µm Ø pores, however, the correlations disappeared after the incubation. Soils from the systems with demonstrated belowground C transfer displayed lower losses of root-derived C during incubation than the systems where interplant C transfer was negligible. Factors facilitating interplant C transfer appear to also lead to placement of root-derived C into smaller pores and to its greater protection there.

Design and manufacturing optimization of epoxy-based adhesive specimens for multiaxial tests

Specimen design and manufacturing quality are decisive factors in the experimental determination of material properties, because they can only be reliably determined if all undesired influences have been minimized or are precisely known. The manufacture of specimens from highly viscous, two-component and fiber-reinforced structural adhesives presents a challenge from this point of view. Therefore, a design and manufacturing optimization procedure for fiber-reinforced structural adhesives and multiaxial testing was developed. It incorporated a finite element parametric study to minimize stress concentrations in the specimen geometry. Vacuum speed mixing was combined with 3D printed mold inserts to enable the manufacture of homogeneous specimens with negligible porosity. The method was demonstrated by means of a structural adhesive used to manufacture wind turbine rotor blades, while the manufacturing quality was verified with high-resolution X-ray microscopy (μCT scanning), enabling detailed detection of pores and geometrical imperfections. The results of uniaxial and biaxial static tests show maximized strength and stiffness properties, while the scatter was minimized in comparison to that stated in international literature. A comparison of the mechanical properties and associated manufacturing techniques is given. The comparison includes a porosity analysis of a specimen from an industrial dosing machine used for rotor blade manufacture.

Ablation of Proliferating Osteoblast Lineage Cells After Fracture Leads to Atrophic Nonunion in a Mouse Model.

Nonunion is defined as the permanent failure of a fractured bone to heal, often necessitating surgical intervention. Atrophic nonunions are a subtype that are particularly difficult to treat. Animal models of atrophic nonunion are available; however, these require surgical or radiation-induced trauma to disrupt periosteal healing. These methods are invasive and not representative of many clinical nonunions where osseous regeneration has been arrested by a "failure of biology". We hypothesized that arresting osteoblast cell proliferation after fracture would lead to atrophic nonunion in mice. Using mice that express a thymidine kinase (tk) "suicide gene" driven by the 3.6Col1a1 promoter (Col1-tk), proliferating osteoblast lineage cells can be ablated upon exposure to the nucleoside analog ganciclovir (GCV). Wild-type (WT; control) and Col1-tk littermates were subjected to a full femur fracture and intramedullary fixation at 12 weeks age. We confirmed abundant tk+ cells in fracture callus of Col-tk mice dosed with water or GCV, specifically many osteoblasts, osteocytes, and chondrocytes at the cartilage-bone interface. Histologically, we observed altered callus composition in Col1-tk mice at 2 and 3 weeks postfracture, with significantly less bone and more fibrous tissue. Col1-tk mice, monitored for 12 weeks with in vivo radiographs and micro-computed tomography (μCT) scans, had delayed bone bridging and reduced callus size. After euthanasia, ex vivo μCT and histology showed failed union with residual bone fragments and fibrous tissue in Col1-tk mice. Biomechanical testing showed a failure to recover torsional strength in Col1-tk mice, in contrast to WT. Our data indicates that suppression of proliferating osteoblast-lineage cells for at least 2 weeks after fracture blunts the formation and remodeling of a mineralized callus leading to a functional nonunion. We propose this as a new murine model of atrophic nonunion. © 2021 American Society for Bone and Mineral Research (ASBMR).

Effect of captivity on the vertebral bone microstructure of xenarthran mammals.

Captive specimens in museum collections facilitate study of rare taxa, but the lifestyles, diets, and lifespans of captive animals differ from their wild counterparts. Trabecular bone architecture adapts to in vivo forces, and may reflect interspecific variation in ecology and behavior as well as intraspecific variation between captive and wild specimens. We compared trunk vertebrae bone microstructure in captive and wild xenarthran mammals to test the effects of ecology and captivity. We collected μCT scans of the last six presacral vertebrae in 13 fossorial, terrestrial, and suspensorial xenarthran species (body mass: 120 g to 35 kg). For each vertebra, we measured centrum length; bone volume fraction (BV.TV); trabecular number and mean thickness (Tb.Th); global compactness (GC); cross-sectional area; mean intercept length; star length distribution; and connectivity and connectivity density. Wild specimens have more robust trabeculae, but this varies with species, ecology, and pathology. Wild specimens of fossorial taxa (Dasypus) have more robust trabeculae than captives, but there is no clear difference in bone microstructure between wild and captive specimens of suspensorial taxa (Bradypus, Choloepus), suggesting that locomotor ecology influences the degree to which captivity affects bone microstructure. Captive Tamandua and Myrmecophaga have higher BV.TV, Tb.Th, and GC than their wild counterparts due to captivity-caused bone pathologies. Our results add to the understanding of variation in mammalian bone microstructure, suggest caution when including captive specimens in bone microstructure research, and indicate the need to better replicate the habitats, diets, and behavior of animals in captivity.

Iodine doping of a photocuring, one-component embedding medium for µCT and histology.

Objective:Evaluation of μCT scans of bone implant complexes often shows a specific problem: if an implant material has a very similar radiopacity as the embedding medium (e.g. methacrylate resin), the implant is not visible in the μCT image. Segmentation is not possible, and especially osseointegration as one of the most important parameter for biocompatibility is not evaluable.Methods:To ensure μCT visualisation and contrast enhancement of the evaluated materials, the embedding medium Technovit® VLC7200 was doped with an iodine monomer for higher radiopacity in different concentrations and tested regarding to handling, polymerisation, and histological preparation, and visualisation in µCT. Six different µCT devices were used and compared with regard to scan conditions, contrast, artefacts, image noise, and spatial resolution for the evaluation of the bone-implant blocks.Results:Visualisation and evaluation of all target structures showed very good results in all μCT scans as well as in histology and histological staining, without negative effects caused by iodine doping. Subsequent evaluation of explants of in vivo experiments without losing important information was possible with iodine doped embedding medium.Conclusion:Visualisation of implants with a similar radiopacity as the embedding medium could be considerably improved. µCT scan settings should be selected with the highest possible resolution, and different implant materials should be scanned individually for optimal segmentation. µCT devices with higher resolutions should be preferred.Advances in knowledge:Iodine doped embedding medium is a useful option to increase radiopacity for better visualisation and evaluation of special target structures in µCT.

Research on coalbed methane microscopic seepage characteristics of medium and high-rank coal

ABSTRACT In the present study, the microscopic seepage characteristics of coalbed methane (CBM) in medium and high-rank coal are investigated. Moreover, the influence of the coal pore structure on the CBM migration is studied. To this end, X-ray μCT scanning technology is utilized to construct the microscopic pore structure model of medium and high-rank coal. Then, the established model is transformed into a vectorized CAD solid model. Numerical simulation under different working conditions is carried out. The obtained results show that the pore system of coal is in a connected state. However, not all pores can penetrate the entire seepage direction. It is found that pore connectivity is the most important factor determining the CBM seepage performance. As coal metamorphism increases, the corresponding seepage pore connectivity decreases, pore throat radius decreases, seepage channels in coal seams decrease and the coal permeability decreases. Meanwhile, permeability anisotropy and the pore pressure of the coal have different changing laws along different seepage paths. It should be indicated that there is a dominant seepage direction. As the degree of coal metamorphism increases, the permeability in all directions gradually decreases.

Soil aeration and redox potential as function of pore connectivity unravelled by X‐ray microtomography imaging

AbstractPlatinum (Pt)‐tipped electrodes are frequently employed to measure the soil redox potential (EH). Thereby, the timely transition from reducing towards oxidising soil conditions is one of the most important biogeochemical changes that can occur in soil. This condition is mainly linked to the air‐filled pore volume (ε) and pore geometries. However, even when the Pt electrodes are located in close vicinity to each other, EH readings behave non‐uniformly, presumably due to the millimetre scaled heterogeneity of pore spaces controlling oxygen (O2) availability and transport. In this study, we examined the ε distribution and pore connectivity in the close vicinity of a Pt electrode during an artificial evaporation experiment using an undisturbed soil sample (Ah‐horizon, Calcaric Gleysol). We combined physio‐chemical methods with non‐destructive X‐ray computed microtomography (μCT) and 3D‐image analysis. μCT scans were conducted at three‐time points, that is, reducing conditions with EH &lt; −100 mV (CT‐1), the transition from reducing towards oxidising conditions with an EH increase &gt; 5 mV h−1 (CT‐2), and oxidising conditions with EH &gt; 300 mV (CT‐3). We observed that the shift from reducing towards oxidising conditions took place at an air‐filled porosity (εCT) of ~0.03 cm3 cm−3, which matches very with gravimetrically calculated data obtained by tensiometry of ε ~0.05 cm3 cm−3. Besides the relation of EH and ε, image analysis revealed that a connected εCT (εCT_conn) of ~0.02 cm3 cm−3 is needed to enable enhanced O2 diffusion from the soil surface towards the Pt surface and facilitate a straightforward EH response. We conclude that εCT_conn is a critical parameter to assess aeration processes in temporarily water‐saturated soils to characterise a switch in redox conditions.Highlights Usually, soil redox dynamics are related to the air‐filled porosity (εCT) but here its connected portion (εCT_conn) was found more relevant. 3D X‐ray computed microtomography imaging close to a redox electrode enabled us to understand the soil aeration process. Connected εCT (εCT_conn) of ~0.02 cm3 cm−3 facilitated oxidising soil conditions. εCT_conn is a critical parameter to assess the aeration process in temporarily water‐saturated soils.

Bone volume in the distal calcaneus correlates with body size but not leap frequency in galagids.

Primate leap performance varies with body size, where performance will be optimized in lightweight individuals due to the inverse relationship between force generation and body mass. With all other factors equal, it is less energetically costly to swing a light hindlimb than a heavier hindlimb. Previous work on the calcaneus of galagids hypothesized that bone volume in leaping galagids may be minimized to decrease overall hindlimb mass. We predict that (1) lighter taxa will exhibit relatively less calcaneal bone volume than heavier taxa, and (2) taxa that are high-frequency leapers will exhibit relatively less bone volume than lower frequency leapers. Relationships among bone volume, body size, and leap frequency (high vs. low) were examined in a sample of 51 individuals from four genera of galagids (Euoticus, Galago, Galagoides, and Otolemur) that differ in the percentage of time engaged in leaping locomotion. Using μCT scans of calcanei, we quantified relative bone volume (BV/TV) of the distal calcaneal segment and predicted that it would vary with body size and frequency of leaping locomotion. Phylogenetic generalized least squares (PGLS) regression models indicate that body size, but not leaping frequency, affects BV/TV in the distal calcaneus. Relative bone volume increases with body size, supporting our first hypothesis. These results support previous work demonstrating a positive correlation between BV/TV and body size. With some exceptions, small galagids tend to have less BV/TV than larger galagids. Leaping frequency does not relate to BV/TV in this sample; larger taxonomic and/or behavioral sampling may provide additional insights.

Quantification of noncircular stent expansion after TAVR into a pathological annulus and its impact on paravalvular leakage

Abstract Patients undergoing transcatheter aortic valve replacement (TAVR) may suffer severe clinical complications, caused by paravalvular leakage (PVL) which is defined as leakage between TAVR and aortic annulus. PVL is often facilitated by a severely calcified annulus. This limits the expansion of a self-expandable TAVR stent. To assess TAVR performance in terms of leakage, measurement of regurgitation fraction in a pathophysiological annulus is recommended according to ISO 5840. For this purpose, a configuration of a circular annulus with a calcification nodule has been proposed in the recently published ISO 5840. The impact of the proposed pathophysiological annulus model on the expansion of self-expandable TAVR stents and on the regurgitation fraction was investigated in this study. For this purpose, two commercially available selfexpandable TAVRs (Evolut R and Portico) were implanted in a calcified annulus model. Circular expansion of the TAVR stents was investigated based on μCT scans of the implanted TAVR. The calcification-induced area in which retrograde flow can occur during diastole was detected. These results were then compared with the experimentally determined regurgitation fraction obtained from pulse duplicator tests. The results of the μCT scans showed a continuous leakage area in the region of the annulus for the Evolut R compared to a locally larger leakage area of the Portico, which, however, reattaches to the annulus in the distal inflow region. The hydrodynamic measurements confirmed a smaller leakage in the pathological annulus for the Portico. In summary, it can be assumed that a continuous leakage area in the TAVR stent inflow region encourages the PVL of TAVR.

Phenotypic regionalization of the vertebral column in the thorny skate Amblyraja radiata: Stability and variation.

Regionalization of the vertebral column occurred early during vertebrate evolution and has been extensively investigated in mammals. However, less data are available on vertebral regions of crown gnathostomes. This is particularly true for batoids (skates, sawfishes, guitarfishes, and rays) whose vertebral column has long been considered to be composed of the same two regions as in teleost fishes despite the presence of a synarcual. However, the numerous vertebral units in chondrichthyans may display a more complex regionalization pattern than previously assumed and the intraspecific variation of such pattern deserves a thorough investigation. In this study, we use micro-computed tomography (µCT) scans of vertebral columns of a growth series of thorny skates Amblyraja radiata to provide the first fine-scale morphological description of vertebral units in a batoids species. We further investigate axial regionalization using a replicable clustering analysis on presence/absence of vertebral elements to decipher the regionalization of the vertebral column of A. radiata. We identify four vertebral regions in this species. The two anteriormost regions, named synarcual and thoracic, may undergo strong developmental or functional constraints because they display stable patterns of shapes and numbers of vertebral units across all growth stages. The third region, named hemal transitional, is characterized by high inter-individual morphological variation and displays a transition between the monospondylous (one centrum per somite) to diplospondylous (two centra per somite) conditions. The posteriormost region, named caudal, is subdivided into three sub-regions with shapes changing gradually along the anteroposterior axis. These regionalized patterns are discussed in light of ecological habits of skates.

Effect of Binder Coatings on the Fracture Behavior of Polymer–Crystal Composite Particles Using the Discrete Element Method

Polymer–crystal composite particles formed by crystals coated with binders are widely used in the fields of medicine, energy, the chemical industry, and civil engineering. Binder content is an important factor in determining the mechanical behavior of composite particles. Therefore, this study aimed to investigate the underlying effect of binder coatings in the fracture micromechanics of polymer–crystal composite particles using the discrete element method (DEM). To achieve this objective, realistic particle and crystal shapes were first obtained and reconstructed based on X-ray micro-computed tomography (μCT) scanning and scanning electron microscope (SEM) images. A series of single particle crushing tests and DEM simulations were conducted on real and reconstructed polymer–crystal composite particles, respectively. Based on the experimental and DEM results, the effect of binder coatings on the crushing strength and crushing patterns of polymer–crystal composite particles was measured. Moreover, the micromechanics of the development and distribution of microcracks was further investigated to reveal the mechanism by which binder coatings affect polymer–crystal composite particles.

The effect of low intensity pulsed ultrasound on mandibular condylar growth in young adult rats

There is a need for more effective methods to enhance mandibular growth in young adults with mandibular deficiency. Previous studies suggest that low intensity pulsed ultrasound (LIPUS) can enhance mandibular growth in growing individuals. This study aimed to evaluate the potential growth changes of the mandible following 4-week LIPUS application in young adult rats. Nineteen ≈120-day-old female rats were allocated to experimental (n = 10) and control (n = 9) groups. The animals in the experimental group were treated with LIPUS to their temporomandibular joints (TMJs) bilaterally, 20 min each day for 28 consecutive days. Animals were then euthanized; gross morphological evaluation was performed on 2D photographs and 3D virtual models of hemi-mandibles, and microstructural assessment was done for the mandibular condyle (MC). Evaluation of mineralization and microarchitecture properties of subchondral cancellous bone was performed by micro-computed tomography (μCT) scanning. Qualitative and histomorphometric analysis was done on condylar cartilage and subchondral bone following Alcian Blue/PAS and Goldner's Trichrome staining. Vital flourochrome (calcein green) labeling was also utilized to determine the amount of endochondral bone growth. Gross morphological evaluations showed a slight statistically non-significant increase especially in the main condylar growth direction in the LIPUS group. Moreover, 3D evaluation depicted an enhanced periosteal bone apposition at the site of LIPUS application. Microstructural analysis revealed that LIPUS stimulates both chondrogenesis and osteogenesis and enhances endochondral bone formation in young adult rat MC. Furthermore, the effect of LIPUS on osteogenic cells of subchondral cancellous bone was notable. To conclude, LIPUS can enhance young adult rats' MC residual growth potential.

Phage Targeting Streptococcus mutans In Vitro and In Vivo as a Caries-Preventive Modality.

Dental caries is a common infectious disease worldwide. Current conventional therapies lack specific antimicrobial effects against Streptococcus mutans, a key bacterium that induces caries. A promising alternative approach is bacteriophage (phage) therapy. Recently, SMHBZ8 phage targeting S. mutans was isolated and characterized. The aim of this study was to evaluate the caries-prevention efficacy of SMHBZ8 using in vitro and in vivo caries models. Hemi-mandibles dissected from euthanized healthy mice were subjected to caries-promoting conditions in vitro. Jaws treated with phage therapy in suspension and in formulation with a sustained-release delivery system showed no carious lesions, similar to control and chlorhexidine-treated jaws. Subsequently, SMHBZ8 phage suspension also prevented carious lesion development in a murine caries model in vivo. In both models, caries lesions were analyzed clinically and radiographically by µCT scans. This study shows how SMHBZ8 phage therapy targeting S. mutans can serve as an efficient caries-prevention modality, in suspension or with a sustained-release delivery system, by in vitro and in vivo mouse models.

Insights into the Development of Phototrophic Biofilms in a Bioreactor by a Combination of X-ray Microtomography and Optical Coherence Tomography.

As productive biofilms are increasingly gaining interest in research, the quantitative monitoring of biofilm formation on- or offline for the process remains a challenge. Optical coherence tomography (OCT) is a fast and often used method for scanning biofilms, but it has difficulty scanning through more dense optical materials. X-ray microtomography (μCT) can measure biofilms in most geometries but is very time-consuming. By combining both methods for the first time, the weaknesses of both methods could be compensated. The phototrophic cyanobacterium Tolypothrix distorta was cultured in a moving bed photobioreactor inside a biocarrier with a semi-enclosed geometry. An automated workflow was developed to process µCT scans of the biocarriers. This allowed quantification of biomass volume and biofilm-coverage on the biocarrier, both globally and spatially resolved. At the beginning of the cultivation, a growth limitation was detected in the outer region of the carrier, presumably due to shear stress. In the later phase, light limitations could be found inside the biocarrier. µCT data and biofilm thicknesses measured by OCT displayed good correlation. The latter could therefore be used to rapidly measure the biofilm formation in a process. The methods presented here can help gain a deeper understanding of biofilms inside a process and detect any limitations.

Psoralidin prevents caffeine-induced damage and abnormal differentiation of bone marrow mesenchymal stem cells via the classical estrogen receptor pathway.

BackgroundCaffeine is broadly present in tea, coffee, and cocoa, and is commonly consumed. The bone microenvironment might be damaged by excessive caffeine, which has been shown to exert negative effects on human health. In this study, we sought to determine whether excessive caffeine could damage the biological functions of bone marrow mesenchymal stem cells (BMSCs) and induce bone loss in mice, and further investigate effective therapeutic methods.MethodsBMSCs were treated with different concentrations of caffeine (0.01, 0.05, 0.1, 0.5, and 1.0 mM) for 48 h. Cell counting kit-8 (CCK-8) assay, colony formation assay, wound healing assay, and quantitative real-time polymerase chain reaction (qRT-PCR) analysis were performed to detect the cell viability, proliferation, migration, and pluripotency of BMSCs, respectively. Alizarin red S (ARS) staining, alkaline phosphatase (ALP) staining, oil red O (ORO) staining, and qRT-PCR assay were applied to assess the osteogenic and adipogenic differentiation of BMSCs. BMSCs were treated with caffeine and further exposed to different concentrations of psoralidin (PL) (0.01, 0.1, 1, and 10 µM) for 48 h. Micro-computed tomography (µCT) scanning was used to evaluate the bone mass of mice. 7α-(7-((4,4,5,5,5-Pentafluoropentyl)-sulfiny)nonyl)estra-1,3,5(10)-triene-3,17β-diol (ICI 182,780, ICI) was applied to examine whether the classical estrogen receptor (ER) pathway was involved.ResultsThe CCK-8 assay, colony formation assay, wound healing assay, and qRT-PCR analysis indicated that caffeine (0.01, 0.05, 0.1, 0.5, 1.0 mM) attenuated the cell viability, proliferation, migration and pluripotency of BMSCs, respectively, in a concentration-dependent manner. Caffeine treatment inhibited osteogenic differentiation but promoted adipogenic differentiation of BMSCs in a dose-dependent manner. Furthermore, ARS staining, ALP staining, ORO staining, and qRT-PCR assay showed that excessive caffeine induced bone loss and osteoporosis (OP) in mice by regulating the osteogenesis and adipogenesis of BMSCs. Also, PL treatment could reverse the caffeine-induced dysfunctions and aberrant differentiation of BMSCs via the ER pathway.ConclusionsOur results revealed a novel molecular mechanism for the therapeutic effects of PL in treating excessive caffeine-induced OP, which might shed new light on the clinical application of PL for caffeine-related OP.

Influence of µCT scanning resolution and volume on FEM-simulation of periodic 3D-printed porous ceramics

Complex cellular ceramic structures are commonly fabricated via replica technique, gel-casting, or freeze-drying. These structures exhibit a manufacturing-related heterogeneity in their microstructure associated with a large scattering range of their physical properties. This further complicates the determination of the representative volume-of-interest (VOI) for the corresponding characterization method. Periodic cellular ceramics can be systematically investigated by µCT analysis to determine the influence of the scan resolution on the results of the mechanical FEM simulation under the same boundary conditions (load, displacement). In this work, a complex 3D printed Al2O3 structure with 3×3×3 arranged cubic unit cells is scanned with three different µCT resolutions (6.87 µm, 13.56 µm and 27.11 µm). From the scans, FE models and sub-volumes are created with a gradation by a factor of 2 down to 1/8 of the initial volume to determine the representative VOI. It was demonstrated that a good agreement with the experimental data can only be achieved with the highest scanning resolution, but here a reduction of the VOI by a factor of four is possible to obtain identical results despite slight production-related deviations.

Inside the head of snakes: influence of size, phylogeny, and sensory ecology on endocranium morphology.

Environmental properties, and the behavioral habits of species impact sensory cues available for foraging, predator avoidance and inter/intraspecific communication. Consequently, relationships have been discovered between the sensory ecology and brain morphology in many groups of vertebrates. However, these types of studies have remained scare on snake. Here, we investigate the link between endocranial shape and the sensory-related ecology of snakes by comparing 36 species of snakes for which we gathered six sensory-ecology characteristics. We use µCT scanning and 3D geometric morphometrics to compare their endocranium in a phylogenetically informed context. Our results demonstrate that size is a major driver of endocranial shape, with smaller species tending to maximize endocranial volume using a more bulbous shape, while larger species share an elongate endocranial morphology. Phylogeny plays a secondary role with more derived snakes diverging the most in endocranial shape, compared to other species. The activity period influences the shape of the olfactory and optic tract, while the foraging habitat impacts the shape of the cerebellum and cranial nerve regions: structures involved in orientation, equilibrium, and sensory information. However, we found that endocranial morphology alone is not sufficient to predict the activity period of a species without prior knowledge of its phylogenetic relationship. Our results thus demonstrate the value of utilizing endocranial shape as complementary information to size and volume in neurobiological studies.