micro-CT Image Analysis Research Articles

Local mapping of root orientation traits by X-ray micro-CT and 3d image analysis: A study case on carrot seedlings grown in simulated vs real weightlessness.

Root phenotyping is particularly challenging because of complexity and inaccessibility of root apparatus. Orientation is one of the most important architectural traits of roots and its characterization is generally addressed using multiple approaches often based on overall measurements which are difficult to correlate to plant specific physiological aspects and its genetic features. Hence, a 3D image analysis approach, based on the recent method of Straumit, is proposed in this study to obtain a local mapping of root angles. Proposed method was applied here on radicles of carrot seedlings grown in real weightlessness on the International Space Station (ISS) and on Earth simulated weightlessness by clinorotation. A reference experiment in 1g static condition on Earth was also performed. Radicles were imaged by X-ray micro-CT and two novel root orientation traits were defined: the "root angle to sowing plane" (RASP) providing accurate angle distributions for each analysed radicle and the "root orientation changes" (ROC) number. The parameters of the RASP distributions and the ROC values did not exhibit any significant difference in orientation between radicles grown under clinorotation and on the ISS. Only a slight thickening in root corners was found in simulated vs real weightlessness. Such results showed that a simple uniaxial clinostat can be an affordable analog in experimental studies reckoning on weightless radicles growth. The proposed local orientation mapping approach can be extended also to different root systems providing a contribution in the challenging task of phenotyping complex and important plant structures such as roots.

REVITALIZATION OF CRITICAL-SIZED CALVARIAL DEFECTS IN RATS USING HEPARIN-CONJUGATED FIBRIN HYDROGEL WITH BMP-2 AND ADIPOSE-DERIVED PERICYTES

Massive bone defects present challenges in orthopedic surgery, requiring innovative solutions. Hydrogels offer promise due to their resemblance to the extracellular matrix. Adipose tissue-derived pericytes (ADPs) and osteoinductive proteins like BMP-2 show potential for bone tissue engineering. Combining them via heparin-conjugated fibrin hydrogel aims to enhance healing in critical-sized calvarial defects. The study investigated the use of a heparin-conjugated fibrin (HCF) hydrogel containing BMP-2 and adipose-derived pericytes for repairing critical-sized calvarial defects in rats. ADPs were cultured from rat adipose tissue, and the HCF hydrogel was prepared accordingly. In vitro experiments assessed BMP-2 release kinetics and bioactivity, while mineralization assays were conducted on cultured ADPs. In vivo experiments involved surgically creating calvarial defects in rats and implanting HCF gel alone or with BMP-2, pericytes, or both. Micro-CT imaging and histological analysis were performed post-implantation to evaluate bone formation. In our study, we prepared the HCF hydrogel by combining heparin-conjugated fibrinogen, human fibrinogen, human thrombin, aprotinin, and calcium chloride. Gelation occurred within 3 minutes at room temperature. SEM analysis revealed an open interconnected pore morphology and macroporous structure, facilitating cell attachment and proliferation. ELISA showed sustained release of BMP-2 from the HCF hydrogel over 28 days. Bioactivity assays demonstrated the ability of released BMP-2 to enhance ALP activity in rat neonatal calvarial osteoblasts. Additionally, BMP-2 induced osteogenic differentiation of rat ADPs, as evidenced by increased ALP activity, osteocalcin expression, and calcium deposition. Implantation of HCF hydrogels containing BMP-2 and/or ADPs into rat calvarial defects significantly promoted bone tissue regeneration compared to controls, with the greatest effect observed in the group receiving both BMP-2 and ADPs. Micro-CT and histological analysis confirmed substantial bone formation and defect closure after three months. In conclusion, our in vitro findings demonstrated that the HCF hydrogel provided sustained release of BMP-2, retaining its bioactivity and promoting osteogenesis in rat calvarial osteoblasts and ADPs. In vivo results showed that combining allogeneic ADPs with BMP-2 enhanced bone regeneration in critical-sized calvarial defects, indicating the potential of this approach for large bone defect restoration.

Synchrotron tomography of magnetoprimed soybean plant root system architecture grown in arsenic-polluted soil.

The present study evaluated the repercussions of magnetopriming on the root system architecture of soybean plants subjected to arsenic toxicity using synchrotron radiation source based micro-computed tomography (SR-µCT). This will be used evey where as abbreviation for the technique for three-dimensional imaging. Seeds of soybean were exposed to the static magnetic field (SMF) of strength (200 mT) for 1h prior to sowing. Magnetoprimed and non-primed seeds were grown for 1 month in a soil-sand mixture containing four different levels of sodium arsenate (0, 5, 10, and 50 mg As kg-1 soil). The results showed that arsenic adversely affects the root growth in non-primed plants by reducing their root length, root biomass, root hair, size and number of root nodules, where the damaging effect of As was observed maximum at higher concentrations (10 and 50 mg As kg-1 soil). However, a significant improvement in root morphology was detected in magnetoprimed plants where SMF pretreatment enhanced the root length, root biomass, pore diameter of cortical cells, root hair formation, lateral roots branching, and size of root nodules and girth of primary roots. Qualitative analysis of x-ray micro-CT images showed that arsenic toxicity damaged the epidermal and cortical layers of the root as well as reduced the pore diameter of the cortical cells. However, the diameter of cortical cells pores in magnetoprimed plants was observed higher as compared to plants emerged from non-primed seeds at all level of As toxicity. Thus, the study suggested that magnetopriming has the potential to attenuate the toxic effect of As and could be employed as a pre-sowing treatment to reduce the phytotoxic effects of metal ions in plants by improving root architecture and root tolerance index. This study is the very first exploration of the potential benefits of magnetopriming in mitigating the toxicity of metals (As) in plant roots utilizing the micro-CT technique.

Comparative Analysis of Water-Induced Response in 3D-Printed SCF/ABS Composites under Controlled Diffusion

Additive manufacturing (AM) or 3D-printing of fiber-reinforced composites (FRCs) has garnered significant interests for its versatility in creating intricate parts and rapid prototyping due to cost-effectiveness. Although short fiber-reinforced thermoplastic composites are challenging to manufacture, their mechanical properties can be easily tailored by adjusting fiber type, orientation, and volume fraction. However, void formation during printing is a key issue, impacting mechanical properties and facilitating water ingression, affecting long-term durability. This work studies water diffusion characteristics and the associated hydro-aging of 3D-printed short carbon fiber (SCF)/acrylonitrile butadiene styrene (ABS) composites with controlled water diffusion. Effects of material type (ABS and SCF/ABS), 3D-printing path (horizontal and vertical filament orientation), and diffusion surface (uni-directional and bi-directional diffusion) on water diffusion coefficient and maximum water absorption level are characterized to ensure the long-term durability of 3D-printed ABS and SCF/ABS composites. Baseline representative volume element-based finite element (RVE-FE) diffusion models were developed based on micro-computed tomography (micro-CT) image analysis to understand water diffusion characteristics. This work proves that the SCF/ABS composite is more resistive to hydro-aging than neat ABS due to the SCFs’ hydrophobic nature. SCF/ABS composites, while providing distinct advantages over pure ABS in terms of mechanical properties, could also be more effective against water environments.

Relative permeability evolution with thermo-poromechanical process during N2 and scCO2 injection in brine saturated Deadwood sandstone from Aquistore

This study delves into the intrinsic and multiphase flow properties, specifically steady-state drainage relative permeability, of a subsurface Deadwood sandstone from the Aquistore CO2 storage site in Canada. Consecutive core-flooding experiments were conducted utilizing N2- and scCO2-brine pairs across a broad range of temperatures (20–70 °C) and isotropic effective stress (0–30 MPa). Moreover, we monitored crack initiation and propagation of the sandstone during uniaxial loading at an elevated temperature using an integrated approach that combines microCT scanning with an in-situ heating/loading test. Our findings reveal a 54 % decrease and a 3 % increase in the absolute permeability of the sandstone through isothermal compaction followed by thermal expansion processes, respectively. Elevating the temperature from 20 °C to 70 °C results in a systematic 24 % increase in irreducible brine saturation and nearly doubles the end-point N2 mobility, indicating an increased tendency of the rock surface towards the brine phase with temperature. Substituting N2 with scCO2 demonstrates a leftward shift in relative permeability and a decrease in irreducible brine saturation (from 0.36 to 0.31), consistent with low interfacial tension and the de-wetting effect during cyclic scCO2-brine injections. Micro-CT image analysis reveals micro-crack initiation at 10 MPa stress and 70 °C temperature, suggesting that a mixed impact of induced cracks, dynamic wettability, and thermo-mechanical deformation is responsible for the substantial increase in well injectivity over time in Aquistore. This novel experimental program provides indispensable insight into thermo-poromechanical and wettability controls on multiphase flow at the Aquistore injection site in Canada, with potential applicability to similar scenarios globally.

The effect of mechanical compaction on the soil water retention curve: Insights from a rapid image analysis of micro-CT scanning

Soil hydrological and agricultural properties are highly affected by the soil water retention characteristics, which are closely related to the void size distribution and structure of the soil. Agricultural lands are often faced with the challenge of soil compaction, which alters the size, shape, connectivity, and morphology of soil voids. To determine the water retention curve and other hydrological and agricultural functions of un-compacted and compacted sandy soils, we used micro-CT techniques and image analysis procedures in both two and three dimensions. We found that these techniques were reliable, as they were validated against physical measurements and empirical physically-based models, and provided a relatively simple and fast way to characterize the key features of soil hydrological and agricultural properties. The findings highlight the impact of compaction on the soil void size distribution, resulting in increased water holding capacity, greater water availability for root uptake, and reduced hydraulic conductivity. We also discussed the differences between the two and three-dimensional analyses, highlighting the better ability to characterize soil hydrological and agricultural functions and soil water retention curve using the three-dimensional image analysis approach.

Micromechanics of multiphase geomaterials based on micro-CT image analysis: unsaturated soil, vegetated soil, and bio-cementation

Under the influence of climate change, extreme weather events such as rainstorms may induce fluctuations in soil water content above the groundwater level, thereby causing geological disasters (e.g., landslides). To mitigate these hazards, green and low-carbon engineering measures such as vegetation reinforcement and bio-cementation are proposed. This study investigates the micromechanical properties of multiphase geomaterials—unsaturated soil, vegetation-reinforced sand, and bio-cemented sand—utilizing high-resolution computed tomography (CT) scanning technology and associated image analysis techniques. The findings are presented as follows: (1) a 4D examination of the macroscopic and microscopic behaviors of unsaturated granular materials under triaxial loading conditions was conducted using self-designed in situ CT scanning equipment. (2) Triaxial loading alters the distribution of phase interfacial surfaces in unsaturated soil, affecting its overall strength. This loading also increases the anisotropy of the solid skeleton and suction stress. (3) The global saturation of the root–soil complex diminishes with root growth, with pore distribution significantly influencing local saturation. (4) In the unsaturated MICP process, low-saturation conditions are preferable for effective cementation, although the saturation levels should be restricted to 20%. After calcification, the particle contact coordination number increases, maintaining the isotropy in the contact between the soil particles.

Reconstruction of Segmental Bone Defect in Canine Tibia Model Utilizing Bi-Phasic Scaffold: Pilot Study.

The reunion and restoration of large segmental bone defects pose significant clinical challenges. Conventional strategies primarily involve the combination of bone scaffolds with seeded cells and/or growth factors to regulate osteogenesis and angiogenesis. However, these therapies face inherent issues related to immunogenicity, tumorigenesis, bioactivity, and off-the-shelf transplantation. The biogenic micro-environment created by implanted bone grafts plays a crucial role in initiating the bone regeneration cascade. To address this, a highly porous bi-phasic ceramic synthetic bone graft, composed of hydroxyapatite (HA) and alumina (Al), was developed. This graft was employed to repair critical segmental defects, involving the creation of a 2 cm segmental defect in a canine tibia. The assessment of bone regeneration within the synthetic bone graft post-healing was conducted using scintigraphy, micro-CT, histology, and dynamic histomorphometry. The technique yielded pore sizes in the range of 230-430 μm as primary pores, 40-70 μm as secondary inner microchannels, and 200-400 nm as tertiary submicron surface holes. These three components are designed to mimic trabecular bone networks and to provide body fluid adsorption, diffusion, a nutritional supply, communication around the cells, and cell anchorage. The overall porosity was measured at 82.61 ± 1.28%. Both micro-CT imaging and histological analysis provided substantial evidence of robust bone formation and the successful reunion of the critical defect. Furthermore, an histology revealed the presence of vascularization within the newly formed bone area, clearly demonstrating trabecular and cortical bone formation at the 8-week mark post-implantation.

Paeoniflorin mitigates MMP-12 inflammation in silicosis via Yang-Yin-Qing-Fei Decoction in murine models

BackgroundSilicosis presents a significant clinical challenges and economic burdens, with Traditional Chinese Medicine (TCM) emerging as a potential therapeutic avenue. However, the precise effects and mechanisms of TCM in treating silicosis remain uncertain and subject to debate. ObjectiveThe study aims to elucidate the therapeutic role and mechanisms of the Yang-Yin-Qing-Fei Decoction (YYQFD) and its key component, paeoniflorin, in silicosis using a murine model. MethodsSilicotic mice were treated with YYQFD, pirfenidone (PFD), or paeoniflorin. RAW264.7 cells and mouse lung fibroblasts (MLF) were stimulated with silica, matrix metalloproteinase-12 (MMP-12), or TGF-β1, followed by treatment with paeoniflorin, PFD, or relevant inhibitors. YYQFD constituents were characterized using High-Performance Liquid Chromatography (HPLC). Lung fibrosis severity was assessed via histopathological examination, micro-CT imaging, lung functions, and Western blot analysis. Transcriptome sequencing and bioinformatics analysis were employed to delineate the gene expression profile and target genes modulated by YYQFD in silicosis. ResultsTreatment with YYQFD ameliorated silica-induced lung fibrosis. Transcriptome sequencing identified MMP-12 as a potential common target of YYQFD and PFD. Additionally, a potential pro-inflammatory role of MMP-12, regulated by silica-induced TLR4 signaling pathways, was revealed. Paeoniflorin, one of the most distinctive compounds in YYQFD, attenuated silica-induced MMP-12 increase and its derived inflammatory factors in macrophages through a direct binding effect. Notably, paeoniflorin treatment exerted anti-fibrotic effects by inhibiting MMP-12-derived inflammatory factors and TGF-β1-induced myofibroblast differentiation in silica-exposed mice. ConclusionsThis study underscores paeoniflorin as one of the most principal bioactive compounds in YYQFD, highlighting its capacity to attenuate lung inflammation driven by macrophage-derived MMP-12 and reduce lung fibrosis both in vivo and in vitro.

Mechanoregulation analysis of bone formation in tissue engineered constructs requires a volumetric method using time-lapsed micro-computed tomography

Bone can adapt its microstructure to mechanical loads through mechanoregulation of the (re)modeling process. This process has been investigated in vivo using time-lapsed micro-computed tomography (micro-CT) and micro-finite element (FE) analysis using surface-based methods, which are highly influenced by surface curvature. Consequently, when trying to investigate mechanoregulation in tissue engineered bone constructs, their concave surfaces make the detection of mechanoregulation impossible when using surface-based methods. In this study, we aimed at developing and applying a volumetric method to non-invasively quantify mechanoregulation of bone formation in tissue engineered bone constructs using micro-CT images and FE analysis. We first investigated hydroxyapatite scaffolds seeded with human mesenchymal stem cells that were incubated over 8 weeks with one mechanically loaded and one control group. Higher mechanoregulation of bone formation was measured in loaded samples with an area under the curve for the receiver operating curve (AUCformation) of 0.633–0.637 compared to non-loaded controls (AUCformation: 0.592–0.604) during culture in osteogenic medium (p < 0.05). Furthermore, we applied the method to an in vivo mouse study investigating the effect of loading frequencies on bone adaptation. The volumetric method detected differences in mechanoregulation of bone formation between loading conditions (p < 0.05). Mechanoregulation in bone formation was more pronounced (AUCformation: 0.609–0.642) compared to the surface-based method (AUCformation: 0.565–0.569, p < 0.05). Our results show that mechanoregulation of formation in bone tissue engineered constructs takes place and its extent can be quantified with a volumetric mechanoregulation method using time-lapsed micro-CT and FE analysis. Statement of significanceMany efforts have been directed towards optimizing bone scaffolds for tissue growth. However, the impact of the scaffolds mechanical environment on bone growth is still poorly understood, requiring accurate assessment of its mechanoregulation. Existing surface-based methods were unable to detect mechanoregulation in tissue engineered constructs, due to predominantly concave surfaces in scaffolds. We present a volumetric approach to enable the precise and non-invasive quantification and analysis of mechanoregulation in bone tissue engineered constructs by leveraging time-lapsed micro-CT imaging, image registration, and finite element analysis. The implications of this research extend to diverse experimental setups, encompassing culture conditions, and material optimization, and investigations into bone diseases, enabling a significant stride towards comprehensive advancements in bone tissue engineering and regenerative medicine.

From breast cancer cell homing to the onset of early bone metastasis: The role of bone (re)modeling in early lesion formation.

Breast cancer often metastasizes to bone, causing osteolytic lesions. Structural and biophysical changes are rarely studied yet are hypothesized to influence metastasis. We developed a mouse model of early bone metastasis and multimodal imaging to quantify cancer cell homing, bone (re)modeling, and onset of metastasis. Using tissue clearing and three-dimensional (3D) light sheet fluorescence microscopy, we located enhanced green fluorescent protein-positive cancer cells and small clusters in intact bones and quantified their size and spatial distribution. We detected early bone lesions using in vivo microcomputed tomography (microCT)-based time-lapse morphometry and revealed altered bone (re)modeling in the absence of detectable lesions. With a new microCT image analysis tool, we tracked the growth of early lesions over time. We showed that cancer cells home in all bone compartments, while osteolytic lesions are only detected in the metaphysis, a region of high (re)modeling. Our study suggests that higher rates of (re)modeling act as a driver of lesion formation during early metastasis.

MicroCT and Histological Analysis of Clot Composition in Acute Ischemic Stroke : AComparative Study of MT-Retrieved Clots and Clot Analogs.

Assessing clot composition on prethrombectomy computed tomography (CT) imaging may help in stroke treatment planning. In this study we seek to use microCT imaging of fabricated blood clots to understand the relationship between CT radiographic signals and the biological makeup. Clots (n = 10) retrieved by mechanical thrombectomy (MT) were collected, and 6clot analogs of varying RBC composition were made. We performed paired microCT and histological image analysis of all 16clots using aScanCo microCT 100 (4.9 µm resolution) and standard H&E staining (imaged at 40×). From these data types, first order statistic (FOS) radiomics were computed from microCT, and percent composition of RBCs (%RBC) was computed from histology. Polynomial and linear regression (LR) were used to build statistical models based on retrieved thrombus microCT and %RBC that were evaluated for their ability to predict the %RBC of clot analogs from mean HU. Correlation analyses of microCT FOS with composition were completed for both retrieved clots and analogs. The LR model fits relating MT-retrieved clot %RBC with mean (R2 = 0.625, p = 0.006) and standard deviation (R2 = 0.564, p < 0.05) in HUs on microCT were significant. Similarly, LR models relating analog histological %RBC to analog protocol %RBC (R2 = 0.915, p = 0.003) and mean HUs on microCT (R2 = 0.872, p = 0.007) were also significant. When the LR model built using MT-retrieved clots was used to predict analog %RBC from mean HUs, significant correlation was observed between predictions and actual histological %RBC (R2 = 0.852, p = 0.009). For retrieved clots, significant correlations were observed for energy and total energy with %RBC and %FP (|R| > 0.7, q < 0.01). Analogs further demonstrated significant correlation between FOS energy, total energy, variance and %WBC (|R| > 0.9, q < 0.01). MicroCT can be used to build models that predict AIS clot composition from routine CT parameters and help us to better understand radiomic signatures associated with clot composition and first pass outcomes. In future work, such observations can be used to better infer clot composition and inform thrombectomy prognostics from pretreatment CTs.

Assessing pore network heterogeneity across multiple scales to inform CO2 injection models

Geologic heterogeneity is a key feature that must be considered when translations of scaled data are performed. This paper presents the assessment of geologic heterogeneity using a multiscale workflow that includes image analysis-based methods coupled with well log analysis to provide data in which fractals and machine learning methods estimate the carbon dioxide (CO2) storage resource potential of a reservoir. The heterogeneity of rock properties of the complex Bell Creek reservoir in Montana, USA, was explored at the pore scale (∼nm to mm), core scale (∼mm to m), and well scale (∼cm to m). The data used in this study included advanced image analysis of micro-CT (computed tomography) images (pore scale), thin sections (pore scale), plugs and core images (core scale) and well logs (well scale). The micro-CT images were segmented using a U-net segmentation approach into objects of pores and grains. The segmented images were reconstructed into subvolumes of different sizes. Physical properties (porosity and permeability) and fractal dimensions were calculated for the various subvolumes, and Lorenz coefficient (Lc) values, a single parameter to describe the degree of heterogeneity within a pay zone section, were calculated from thin-section images and well logs. Porosity and fractal dimension values were used to estimate the 188-µm threshold of representative elementary volume (REV) in this study. Both the Lc and fractal dimension values were found to be negatively correlated. When these two parameters are combined, it is possible to discern differences in the complex porous networks of the samples analyzed in this study.

Microstructure evolution law and dissolution time effect of bituminous coal under acetic acid acidification: Based on Micro-CT image analysis

Undeveloped pores and fractures in coal seams constrain coalbed methane mining and dust disaster prevention significantly. The existing hydraulic fracturing technology has achieved some effects in coal seam modification. Still, there are hidden dangers in inducing microseismicity and other aspects. Applying acidification technology for pore and fracture modification improves the efficiency of coalbed methane mining and dust suppression. In this paper, 75% concentration of acetic acid was utilized to treat columnar coal samples, and the experimental method of X-ray computed tomography was applied to study the role of dissolution time on the microcomponents and structure of samples. The experimental results showed that the porosity increased with the dissolution time; the effect of acetic acid on the pore expansion and mineral dissolution showed three periods, i.e., the beginning of the reaction period (0 ∼ 12 h), the full reaction period (12 ∼ 48 h), and the reaction slowing down period (>48 h). The mineral volume fraction showed an overall decreasing trend; before 36 h, the dissolution of acetic acid on the mineral structure within the coal was faster, making it loose, which in turn accelerated the dissolution of coal, and after 36 h, the dissolution effect of acetic acid weakened, and the mineral was gradually stabilized. Acetic acid first reacts with minerals in large quantities. With the increase of products, the solution's ionic complexity increases, so acetic acid accelerates the ionization of more H+ ions, and the solution's acidity increases. After a while of dissolution, the content of acetic acid decreases, the ionized H+ ions are not enough to continue to react with the minerals, and the rate of the mineral's crystal particle size reduction slows down gradually. In conclusion, acetic acid has the potential for pore and fracture modification of coal reservoirs. It can affect the mineral through dissolution, at the same time, improve the porosity. The research results provide an essential reference for using acidification technology to modify the pores and fractures in coal seams.

Bioactive Bone Substitute in a Rabbit Ulna Model: Preclinical Study.

Current therapies to effectively treat long-bone defects and extensive bone tissue loss remains limited. In this study, we created a new bone substitute by integrating advanced technologies such as structure patterning, controlled release of a bone growth factor and conjugation system for clinically effective bone regeneration. This novel bioactive bone substitute was evaluated for its safety and efficacy using a rabbit ulna model. A three dimensional bone patterned cylindrical structure with 1.5cm in length and 5mm in diameter was printed using poly(L-lactic acid)(PLLA) as a weight-bearing support and space-filling scaffold. And a bone morphogenetic protein 2 (BMP2) was employed to enhance bone regeneration, and coated to a 3D PLLA using alginate catechol and collagen to prolong the release kinetics. This novel bone substitute (BS)was evaluated for its physico-chemical and biological properties in vitro, and histological analysis and radiographical analysis such as X-ray, CT and micro-CT image analysis were performed to evaluate new bone formation in vivo. The BS possesses an ideal shape and mechanically suitable proeperties for clinical use, with an easy-to-grab and break-resistant design at both ends, 80 ± 10MPa of compression strength, and BMP2 release for two months. Histological analysis demonstrated the biocompability of BS with minimal inflammation and immune response, and X-ray, CT and micro-CT demonstrated effective new bone formation in rabbit ulna defect model. The preclinical study of a novel bioactive bone substitute has shown its safe and effective properties in an animal model suggesting its clinical potential.

Root Cause Analysis of An Inverse Relationship Between The Ice Nucleation Temperature, Process Efficiency And Quality of A Lyophilized Product

The aim of this study was to probe an unexpected relationship between the ice nucleation temperature (TIN), process efficiency and product attributes in a controlled ice nucleation (CIN) lyophilization process. An amorphous product was lyophilized with (CIN-5 °C, CIN-7 °C or CIN-10 °C) or without (NOCIN) control of ice nucleation. Process parameters and product attributes were monitored and compared using a series of advanced in-line and off-line process analytical technology (PAT) tools. Unexpectedly, an indirect relationship was observed between TIN and primary drying efficiency for the CIN processes. Further, the CIN-5 °C process was associated with higher product resistance to mass flow than corresponding CIN-7 °C and CIN-10 °C processes. Surprisingly, the air voids in some NOCIN products were larger than CIN-5 °C products but comparable to CIN-7 °C. Heat flux analysis revealed an indirect relationship between TIN and the minimum hold time required to complete solidification. The heat flux analysis also revealed all products underwent complete solidification prior to primary drying. The order of homogeneity in water activity of the products was CIN-5 °C ≥NOCIN>CIN-7 °C. The higher homogeneity in water activity of CIN-5 °C than corresponding CIN-7 °C processes indicated that the lower process efficiency of CIN-5 °C could not be attributed to unsuccessful induction of ice nucleation during CIN-5 °C. High resolution micro-CT imaging and Artificial Intelligence Image analysis revealed cake wall deformation in CIN-7 °C and NOCIN products but not in CIN-5 °C. In addition, NOCIN products had bimodal distribution in air voids with median size range of 4–5 µm and 151.9–309 µm, respectively, hence the lower process efficiency of NOCIN despite the higher D90. Thus, the observed relationship between TIN and process efficiency may be attributed to microstructural changes post freezing. This hypothesis was corroborated by visible macroscopic cake collapse in NOCIN products but not in CIN products after lyophilization at a higher shelf temperature. In conclusion, the advantages of controlling the ice nucleation temperature of a lyophilization process may only be attained through a robust process design that takes into consideration the primary and secondary drying process parameters. Further, combined use of advanced in-line and off-line PAT tools for process and product characterization may hasten the at scale adoption of advance techniques such as CIN.

Influence of elevated temperature and gas atmosphere on coke abrasion resistance. Part one: Pilot oven cokes

A novel approach was developed to examine coke abrasion resistance in-situ at temperatures of up to 950 °C and in a controlled gas atmosphere using rotational tribological testing. The originality of this approach lay in the ability to apply tribological testing to the porous coke surface at elevated temperatures under a controlled inert or CO2 reactive atmosphere. Coke wear characteristics were quantified via (i) the application of advanced microscopy and image analysis techniques, and (ii) analysis of the coefficient of friction (COF) during tribological testing.Two pilot oven cokes were examined in this study, which were generated from single coking coals of similar rank but different petrographic composition. The cokes tested showed a deterioration in abrasion resistance even at 400 °C, and this was accentuated at 950 °C.The COF and the severity of the wear as a function of temperature and gas atmosphere were markedly different between the two cokes. Coke C396 from a mid-to-low vol, medium vitrinite coal showed no statistically significant differences between the wear severity results recorded following room temperature testing and high temperature testing in a CO2 environment. Conversely, the more reactive coke C426 with a higher parent coal inertinite content showed clear differences in the extent of abrasive wear at room temperature and at high temperature in both inert and reactive gas atmospheres.This suggests that the reduction in abrasion resistance at elevated temperatures is accentuated in the coke with the highest coke reactivity index (CRI) and the highest content of inertinite maceral derived components (IMDC). Our research has shown that at room temperature, the IMDC show greater resistance to abrasion than the reactive maceral derived components (RMDC). This has implications for understanding the relevance of room temperature testing to the abrasion resistance of coke under practical blast furnace operation conditions. For example, a coke from a coal or blend with a comparatively high inertinite content may show lower resistance to abrasion in the blast furnace than would be expected from tumble drum indices. Larger sample numbers and cokes from a variety of single coals need to be tested in further work to verify these assertions.Finally, a novel method using micro-CT image analysis was developed to examine the wear path generated at the coke surface during tribological testing. The purpose of this was to assess the extent of the abrasive wear by comparing the rendered micro-CT images before and after tribological testing. A colour gradient scale was used to facilitate the quantitative assessment, whereby the colour of each voxel was based on the distance from the nearest voxel that is associated with solid phase.As expected, the specific surface area (SSA) calculated for the upper 1 mm of each sample decreased following tribological testing due to the generation of a wear track which is smoother than the initially rough, porous coke surface. In the C426 coke type examined, the SSA decreased the most for the sample tested in an argon atmosphere at 950 °C, matching the COF and quantified wear severity results, which showed there was a notable increase in abrasive wear to this coke as the temperature was raised from room to elevated temperature.Coupling this method of analysis with 3D visualisation techniques in further work would provide a powerful approach to examine and quantify mechanisms of coke surface breakage and the microstructural and/or microtextural features responsible for the breakage.

The strain rate and density dependence of the mechanical properties of closed-cell aluminum foam

Closed-cell aluminum foam (CCAF) is mainly employed as a load-bearing and energy-absorbing structural material due to its superior mechanical properties. However, besides the effect of microstructural and material parameters, the influence of strain rate (SR) and relative density (RD) on metallic foams (MF) on their mechanical behaviors is not fully understood. In this study, micro-computed tomography (micro-CT) imaging and finite element (FE) analysis were used to investigate the static and dynamic yield strength, energy absorption, and the effect of SR and RD on CCAFs. Micro-CT imaging was used to visualize the foam microstructure and measure its overall cell wall thickness and other structural parameters, which were then incorporated into the FE model. The results of the FE simulations were compared to experimental data to validate the constitutive relation. The findings of this study provide new insights into the mechanical behaviors of CCAFs and can be used to optimize its design and structural applications.

Effects of soybean isoflavone aglycone on osteoporosis in ovariectomized rats.

Postmenopausal osteoporosis is one of the most common metabolic diseases in old women, and supplementing estrogen through bioactive substances is one of the important ways to improve menopausal syndrome. Some studies have confirmed that soybean isoflavone has estrogenic activity, and the main active component of soybean isoflavones is isoflavone aglycones. However, few studies have investigated the improvement effect of high-purity soy isoflavone aglycones on postmenopausal osteoporosis. Thus, the effect of different doses of high-purity soybeans isoflavone aglycone on the ovariectomized female osteoporosis rat model was evaluated by oral gavage. The rats were divided into seven experimental groups including SHAM, OVX, EE, SIHP, AFDP-L, AFDP-M, and AFDP-H, which was administered for 60 days from 30 days after ovariectomy. We collected blood from the abdominal aorta of rats on the 30th, 60th, and 90th days respectively, analyzed its serum biochemistry, and took out the femur for micro-CT imaging and bone microstructure parameter analysis. Results showed that the intervention effect of AFDP-H group on osteoporosis rats at 60 and 90 days was similar to that of EE group, and superior to the OVX group, SIHP group, AFDP-L group, AFDP-M group. The AFDP-H group inhibited the decrease in serum bone markers, bone density, trabeculae quantity, trabeculae thickness, and bone volume fraction, and increased the trabecular separation caused by ovariectomy, thereby significantly improving bone microstructure. It also prevented continuous weight gain and increased cholesterol levels in female rats. This study provided theoretical to application of soybean isoflavone aglycone in the intervention of osteoporosis. and confirmed that could replace chemical synthetic estrogen drugs.

Micro-CT Imaging and Morphometric Analysis of Mouse Neonatal Brains.

Neuroimages are a valuable tool for studying brain morphology in experiments using animal models. Magnetic resonance imaging (MRI) has become the standard method for soft tissues, although its low spatial resolution poses some limits for small animals. Here, we describe a protocol for obtaining high-resolution three-dimensional (3D) information on mouse neonate brains and skulls using micro-computed tomography (micro-CT). The protocol includes those steps needed to dissect the samples, stain and scan the brain, and obtain morphometric measurements of the whole organ and regions of interest (ROIs). Image analysis includes the segmentation of structures and the digitization of point coordinates. In sum, this work shows that the combination of micro-CT and Lugol's solution as a contrast agent is a suitable alternative for imaging the perinatal brains of small animals. This imaging workflow has applications in developmental biology, biomedicine, and other sciences interested in assessing the effect of diverse genetic and environmental factors on brain development.