Changes of serum metabolomics and gut microbiota reveal specific characteristics of children with febrile seizures.

BACKGROUND AND PURPOSE: Febrile seizures (FS) pose a severe threat to the neurological development of children. Probing the abnormality of host metabolism is essential for the prevention, diagnosis, and treatment of FS. METHODS: Based on clinically collected serum and fecal samples, we used nontargeted metabolomics and 16S rDNA sequencing to explore the relationship of serum metabolite levels and gut microbiota community with the occurrence of FS. RESULTS: Metabolomic analysis revealed abnormalities in multiple metabolic pathways in serum of FS patients, such as tryptophan metabolism and steroid hormone biosynthesis. Intestinal flora analysis indicated that the α-diversity of gut microbiota in FS patients was significantly reduced. In addition, the relative abundance of a variety of bacteria at the phylum level was remarkably changed in patients with FS, including decreased Firmicutes and Verrucomicrobia. Eleven serum metabolites were identified to be biomarker candidates for FS diagnosis. With the help of a panel biomarker strategy combining four biomarkers as a cluster, four bacteria (i.e., Rothia, Coprococcus, Lactobacillus, and Oscillospira) in a defined panel displayed perfect differentiation of subtypes of FS. CONCLUSIONS: Combining metabolomic and intestinal flora analysis revealed specific characteristics of children with FS, and provided new clues for the diagnosis of FS and the classification of seizure types. In summary, these findings may provide new insights into revealing the significance of serum metabolites and gut microbiota in the pathogenesis of FS.

Quercetin, Main Active Ingredient of Moutan Cortex, Alleviates Chronic Orofacial Pain via Block of Voltage-Gated Sodium Channel.

BACKGROUND: Chronic orofacial pain (COP) therapy is challenging, as current medical treatments are extremely lacking. Moutan Cortex (MC) is a traditional Chinese medicine herb widely used for chronic inflammatory diseases. However, the mechanism behind MC in COP therapy has not been well-established. The purpose of this study was to identify the active ingredients of MC and their specific underlying mechanisms in COP treatment. METHODS: In this study, the main active ingredients and compound-target network of MC in COP therapy were identified through network pharmacology and bioinformatics analysis. Adult male Sprague-Dawley rats received oral mucosa lipopolysaccharide (LPS) injection to induce COP. Pain behaviors were evaluated by orofacial mechanical nociceptive assessment after intraganglionar injection. In vitro inflammatory cytokines in LPS-pretreated human periodontal ligament stem cells (hPDLSCs) and rat primary cultural trigeminal ganglion (TG) neurons were quantified by real-time quantitative polymerase chain reaction (RT-qPCR). Schrödinger software was used to verify the molecular docking of quercetin and critical targets. Whole-cell recording electrophysiology was used to evaluate the effect of quercetin on voltage-gated sodium (Na v ) channel in rat TG neurons. RESULTS: The assembled compound-target network consisted of 4 compounds and 46 targets. As 1 of the active components of MC correlated with most related targets, quercetin alleviated mechanical allodynia in LPS-induced rat model of COP (mechanical allodynia threshold median [interquartile range (IQR) 0.5 hours after drug administration: vehicle 1.3 [0.6-2.0] g vs quercetin 7.0 [6.0-8.5] g, P = .002). Gene ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that immune response and membrane functions play essential roles in MC-COP therapy. Five of the related targets were identified as core targets by protein-protein interaction analysis. Quercetin exerted an analgesic effect, possibly through blocking Na v channel in TG sensory neurons (peak current density median [IQR]: LPS -850.2 [-983.6 to -660.7] mV vs LPS + quercetin -589.6 [-711.0 to -147.8] mV, P = .006) while downregulating the expression level of proinflammatory cytokines-FOS (normalized messenger RNA [mRNA] level mean ± standard error of mean [SEM]: LPS [2. 22 ± 0.33] vs LPS + quercetin [1. 33 ± 0.14], P = .034) and TNF-α (normalized mRNA level mean ± SEM: LPS [8. 93 ± 0.78] vs LPS + quercetin [3. 77 ± 0.49], P < .0001). CONCLUSIONS: Identifying Na v as the molecular target of quercetin clarifies the analgesic mechanism of MC, and provides ideas for the development of novel selective and efficient chronic pain relievers.

Upregulations of high mobility group box 1 and TLR4/NF-κB signaling pathway in hippocampus and serum of rats with febrile seizure.

PURPOSE: The aim of this study was to explore the alternations regarding the HMGB1 and TLR4/NF-κB signaling pathway in juvenile rats with febrile seizure (FS). MATERIALS AND METHODS: During the animal modeling of the FS, seizures were triggered every four days by hot water (45 °C), and repeated ten times. After forty days' modeling, rats were divided into different groups according to the degree of seizure (FS (0) - FS (V)). Reverse transcription-polymerase chain reaction (RT-PCR) was used to evaluate the mRNA expressions of the HMGB1, TLR4 and NF-κB in the hippocampus, while Western-blot (WB) and immunofluorescence (IF) were employed to assess protein expressions. The enzyme-linked immunosorbent assay (ELISA) was used for analyzing the protein expressions in peripheral blood. RESULTS: The mRNA levels of the HMGB1, TLR4 and NF-κB in the hippocampus of both FS (V) and FS (IV) groups were significantly higher than WT, while there was no difference between FS (III) and WT. Concerning protein expressions, increased levels of the HMGB1, TLR4, and NF-κB in FS (V) were observed with a good consistency between the WB and IF, while no significant upregulation was shown in FS (IV). The ELISA results showed that the significance of the augmented proteins between the FS (V) and WT were smaller in the serum than the hippocampus. CONCLUSIONS: Our study shows seizure degree-related upregulations of HMGB1 and TLR4/NF-κB signaling pathway both in hippocampus and serum of juvenile rats with FS, suggesting the involvement of TLR/NF-κB pathway in inflammation promoted by HMGB1 during FS.

MiR-155 inhibition alleviates suppression of osteoblastic differentiation by high glucose and free fatty acids in human bone marrow stromal cells by upregulating SIRT1.

Diabetic osteoporosis is a severe and chronic complication of diabetes in the bone and joint system, and its pathogenesis is needed to be explored. In the present study, we examined the effect and underlying mechanism of miR-155 on osteogenic differentiation in human bone marrow-derived mesenchymal stem cells (hBMSCs) under high glucose and free fatty acids (HG-FFA) conditions. It was shown that miR-155 levels in hBMSCs increased corresponding to the time of exposure to HG-FFA treatment. MiR-155 expression was altered by transfecting miR-155 mimic or miR-155 inhibitor. HG-FFA exposure resulted in an obviously decrease in cell viability and alkaline phosphatase (ALP) activity, and downregulated the expressionof runt-related transcription factor 2 (Runx2) and osteocalcin (OCN) in hBMSCs. Transfection of miR-155 mimic further exacerbated HG-FFA-induced inhibitory effect on osteogenic differentiation, and miR-155 inhibitor neutralized this inhibitory effect. Luciferase assays confirmed that SIRT1 was a direct target of miR-155 and can be negatively modulated by miR-155. Furthermore, SIRT1 siRNA partially counteracted miR-155 inhibitor-induced upregulation of SIRT1in HG-FFA-treated hBMSCs. SIRT1 siRNA also reversed the promotional effect of the miR-155 inhibitor on ALP activity and expression of the Runx2 and OCN proteins under HG-FFA conditions. In conclusion, the results suggest that miR-155 suppression promoted osteogenic differentiation of hBMSCs under HG-FFA conditions by targeting SIRT1. Inhibition of MiR-155 may provide a new therapeutic method for the prevention and treatment of diabetic osteoporosis.

Cyclic deformation leads to defect healing and strengthening of small-volume metal crystals.

When microscopic and macroscopic specimens of metals are subjected to cyclic loading, the creation, interaction, and accumulation of defects lead to damage, cracking, and failure. Here we demonstrate that when aluminum single crystals of submicrometer dimensions are subjected to low-amplitude cyclic deformation at room temperature, the density of preexisting dislocation lines and loops can be dramatically reduced with virtually no change of the overall sample geometry and essentially no permanent plastic strain. This "cyclic healing" of the metal crystal leads to significant strengthening through dramatic reductions in dislocation density, in distinct contrast to conventional cyclic strain hardening mechanisms arising from increases in dislocation density and interactions among defects in microcrystalline and macrocrystalline metals and alloys. Our real-time, in situ transmission electron microscopy observations of tensile tests reveal that pinned dislocation lines undergo shakedown during cyclic straining, with the extent of dislocation unpinning dependent on the amplitude, sequence, and number of strain cycles. Those unpinned mobile dislocations moving close enough to the free surface of the thin specimens as a result of such repeated straining are then further attracted to the surface by image forces that facilitate their egress from the crystal. These results point to a versatile pathway for controlled mechanical annealing and defect engineering in submicrometer-sized metal crystals, thereby obviating the need for thermal annealing or significant plastic deformation that could cause change in shape and/or dimensions of the specimen.

Early amplitude-integrated EEG monitoring 6 h after birth predicts long-term neurodevelopment of asphyxiated late preterm infants.

UNLABELLED: The present study aimed to assess the prognostic value of early amplitude-integrated electroencephalogram (aEEG) in late preterm infants who were born at a gestational age between 34 0/7 and 36 6/7 weeks for the prediction of neurobehavioral development. Late preterm infants (n = 170) with normal, mild, and severe asphyxia underwent continuous recording of aEEG for 4-6 h starting 6-8 h after delivery. The recordings were analyzed for background pattern, sleep-wake cycle (SWC), and seizures. Survivors were assessed at 18 months by neurological examination and Bayley Scales of Infant Development II. The incidence of adverse neurological outcome in the asphyxia group was significantly higher than in the normal group. For late preterm infants in the asphyxia group, abnormal aEEG pattern had a predictive potential of neurological outcomes with sensitivity of 78.57% (specificity, 87.80%; positive predictive value [PPV], 68.75%; negative predictive value [NPV], 92.31%; power, 85.45%). Non-SWC and intermediate SWC significantly were increased (25.45 and 52.73%, respectively) in the asphyxia group vs. the normal group. SWC pattern had neurological prognosis value in the asphyxia group with sensitivity of 64.29% (specificity, 87.80%; PPV, 64.29%; NPV, 87.80%; power, 81.82%). CONCLUSION: Early aEEG patterns are important determinants of long-term prognosis of neurodevelopmental outcome in asphyxiated late preterm infants.

Data-Driven Based Characterization of Anisotropic Mechanical Properties for Cancellous Bone From Low-Resolution CT Images.

OBJECTIVES: Exploring the anisotropic mechanical behavior of cancellous bone is crucial for in-vivo bone biomechanical analysis. However, it is challenging to characterize anisotropic mechanical behaviors under low-resolution (LR) clinical CT images due to a lack of microstructural information. The data-driven method proposed in this article accurately characterizes the anisotropic mechanical properties of cancellous bone from LR clinical CT images. METHODS: The trabecular bone cubes of sheep are used to obtain a high-resolution (HR) micro-CT and an LR clinical CT image dataset. First, an auto-encoder model is trained using HR image data. Microstructural features are extracted by the encoder. A fast super-resolution (FSR) model is trained to map LR bone cubes to the features extracted from corresponding HR samples. The pretrained FSR model is used to convert LR clinical CT images to encoded microstructural features. The features are later used to predict target histomorphological parameters, anisotropic elastic tensors, and fabric tensors based on a fully connected neural network. RESULTS: The data-driven model accurately predicts the elastic tensor and fabric tensor of trabecular bones with LR CT images with 0.6 mm/pixel spatial resolution. It was verified that LR clinical CT images could generate microstructural information using a generative deep-learning model and an up-sampling operation. SIGNIFICANCE: This study proves that clinical medical images of cancellous bone can be used for analysis of complex mechanical properties using a data-driven method, which is useful for real-time bone defect diagnosis and personalized bone prosthesis design in clinical application.

Development of pH-freshness smart label based on gellan gum film incorporated with red cabbage anthocyanins extract and its application in postharvest mushroom.

Novel colorimetric films based on gellan gum (GG) containing red cabbage anthocyanins extract (RCAE) were prepared as pH-freshness smart labels for real-time visual detection of mushroom freshness. The GG/RCAE films had excellent pH and ammonia sensitivity. The GG/RCAE-0.2-0.3 films had the highest sensitivity to acetic acid. The SEM micrographs, AFM images, FT-IR and XRD spectra demonstrated that RCAE were successfully combined into the film-forming substrate. The incorporation of RCAE resulted in the increase of thermal stability, opacity and surface hydrophobicity of films. Meanwhile, the GG/RCAE-0.2 film exhibited stronger tensile strength and excellent color stability at 4℃. The color changes of GG/RCAE-0.2 film were visually easier to distinguish during the storage of mushroom. The results showed the GG/RCAE films could be used as pH-freshness smart labels to detect the freshness of fruits and vegetables.

Dexmedetomidine protects against sepsis-induced lung injury through autophagy and Smad2/3 signaling pathway.

Objectives: Dexmedetomidine (Dex) is a potent α2-adrenergic receptor(α2-AR) agonist that has been shown to protect against sepsis-induced lung injury, however, the underlying mechanisms of this protection are not fully understood. Autophagy and the Smad2/3 signaling pathway play important roles in sepsis-induced lung injury, but the relationship between Dex and Smad2/3 is not clear. This study aimed to investigate the role of autophagy and the Smad2/3 signaling pathway in Dex-mediated treatment of sepsis-induced lung injury. Sepsis was performed using cecal ligation and puncture (CLP) in C57BL/6J mice. Materials and Methods: Mice were randomly assigned to four groups (n=6 per group): sham, CLP, CLP-Dex, and CLP-Dex-YOH, Yohimbine hydrochloride (YOH) is an α2-AR blocker. The cecum was carefully separated to avoid blood vessel damage and was identified and punctured twice with an 18-gauge needle. The pathological changes, inflammatory factor levels, oxidative stress, autophagy, Smad2/3 signaling pathway-related protein levels in lung tissues, and the activity of superoxide dismutase (SOD) and malonaldehyde (MDA) in the serum were measured. Results: CLP-induced lung injury was reflected by increased levels of inflammatory cytokines, apoptosis, and oxidative stress, along with an increase in the expression of autophagy and Smad2/3 signaling pathway-related proteins. Dex could reverse these changes and confer a protective effect on the lung during sepsis. However, the administration of YOH significantly reduced the positive effects of Dex in mice with sepsis. Conclusion: Dex exerts its beneficial effects against sepsis-induced lung injury through the regulation of autophagy and the Smad2/3 signaling pathway.

Chitosan/zein-based sustained-release composite films: Fabrication, physicochemical properties and release kinetics of tea polyphenols from polymer matrix.

This study investigated the properties of chitosan/zein/tea polyphenols (C/Z/T) films and analyzed the release kinetics of tea polyphenols (TP) in various food simulants to enhance the sustainability and functionality of food packaging. The results revealed that TP addition enhanced the hydrophilicity, opacity and mechanical properties of film, and improved the compatibility between film matrix. 1.5 % TP film showed the lowest lightness (76.4) and the highest chroma (29.1), while 2 % TP film had the highest hue angle (1.5). However, the excessive TP (above 1 % concentration) led to a decrease in compatibility and mechanical properties of film. The TP concentration (2 %) resulted in the highest swelling degree in aqueous (750.6 %), alcoholic (451.1 %), and fatty (6.4 %) food simulants. The cumulative release of TP decreased to 16.32 %, 47.13 %, and 5.87 % with the increase of TP load in the aqueous, alcoholic, and fatty food simulants, respectively. The Peleg model best described TP release kinetics. The 2 % TP-loaded film showed the highest DPPH (97.13 %) and ABTS (97.86 %) free radical scavenging activity. The results showed TP release influenced by many factors and obeyed Fick's law of diffusion. This study offered valuable insights and theoretical support for the practical application of active films.

Multiscale engineered artificial compact bone via bidirectional freeze-driven lamellated organization of mineralized collagen microfibrils.

Bone, renowned for its elegant hierarchical structure and unique mechanical properties, serves as a constant source of inspiration for the development of synthetic materials. However, achieving accurate replication of bone features in artificial materials with remarkable structural and mechanical similarity remains a significant challenge. In this study, we employed a cascade of continuous fabrication processes, including biomimetic mineralization of collagen, bidirectional freeze-casting, and pressure-driven fusion, to successfully fabricate a macroscopic bulk material known as artificial compact bone (ACB). The ACB material closely replicates the composition, hierarchical structures, and mechanical properties of natural bone. It demonstrates a lamellated alignment of mineralized collagen (MC) microfibrils, similar to those found in natural bone. Moreover, the ACB exhibits a similar high mineral content (70.9 %) and density (2.2 g/cm3) as natural cortical bone, leading to exceptional mechanical properties such as high stiffness, hardness, and flexural strength that are comparable to those of natural bone. Importantly, the ACB also demonstrates excellent mechanical properties in wet, outstanding biocompatibility, and osteogenic properties in vivo, rendering it suitable for a broad spectrum of biomedical applications, including orthopedic, stomatological, and craniofacial surgeries.

Activates B lymphocytes and enhanced immune response: A promising adjuvant based on PLGA nanoparticle to improve the sensitivity of ZEN monoclonal antibody.

In preparing monoclonal antibodies by hybridoma cell technology, the quality of B lymphocytes used for cell fusion directly affects the sensitivity of monoclonal antibodies. To obtain B-lymphocytes producing high-quality specific antibodies for cell fusion during the immunization phase of the antigen, we prepared a TH2-Cell stimulatory delivery system as a novel adjuvant. Astragalus polysaccharide has a good ability to enhance antigenic immune response, and it was encapsulated in biocompatible materials PLGA as an immunostimulatory factor to form the delivery system (APS-PLGA). The preparation conditions of APSP were optimized using RSM to attain the highest utilization of APS. Immunization against ZEN-BSA antigen using APSP as an adjuvant to obtain B lymphocytes producing ZEN-specific antibodies for cell fusion. As results present, APSP could induce a stronger TH2 immune response through differentiating CD4 T cells and promoting IL-4 and IL-6 cytokines. Moreover, it could slow down the release efficiency of ZEN-BSA and enhance the targeting of ZEN-BSA to lymph nodes in vivo experiments. Ultimately, the sensitivity of mouse serum ZEN-specific antibodies was enhanced upon completion of immunization, indicating a significant upregulation of high-quality B lymphocyte expression. In the preparation of monoclonal antibodies, the proportion of positive wells for the first screening was 60%, and the inhibition rates of the antibodies were all similar (>50%). Then we obtained the ZEN monoclonal antibody with IC50 of 0.049 ng/mL, which was more sensitive than most antibodies prepared under conventional adjuvants. Finally, a TRFIAS strip assay was preliminarily established with a LOD value of 0.246 ng/mL.

Seasonal dynamics of the microbiota and nutritional composition in bee bread from Apis cerana and Apis mellifera colonies.

Bee bread is a product of honeybees, which collect and ferment pollen, that contains highly nutritious and easily digestible active substances. However, its nutritional composition varies significantly with fermentation strains and seasonal changes. To unveil the patterns of microbial community and nutritional component changes in bee bread across seasons, we employed high-throughput techniques to assess the diversity of bacteria and fungi in bee bread. The results indicated that the compositions of bacteria and fungi in bee bread undergo significant seasonal variation, with noticeable changes in the microbial diversity of bee bread from different bee species. Subsequently, metabolomic analysis revealed high activity of glycerophospholipid metabolism in bee bread. Furthermore, our analysis identifaied noteworthy differences in nutritional components, including pH values, sugar content, and free amino acid levels, in bee bread across different seasons.

The relationship between gut microbiota and insomnia: a bi-directional two-sample Mendelian randomization research.

Introduction: Insomnia is the second most common mental health issue, also is a social and financial burden. Insomnia affects the balance between sleep, the immune system, and the central nervous system, which may raise the risk of different systemic disorders. The gut microbiota, referred to as the "second genome," has the ability to control host homeostasis. It has been discovered that disruption of the gut-brain axis is linked to insomnia. Methods: In this study, we conducted MR analysis between large-scale GWAS data of GMs and insomnia to uncover potential associations. Results: Ten GM taxa were detected to have causal associations with insomnia. Among them, class Negativicutes, genus Clostridiuminnocuumgroup, genus Dorea, genus Lachnoclostridium, genus Prevotella7, and order Selenomonadalesare were linked to a higher risk of insomnia. In reverse MR analysis, we discovered a causal link between insomnia and six other GM taxa. Conclusion: It suggested that the relationship between insomnia and intestinal flora was convoluted. Our findings may offer beneficial biomarkers for disease development and prospective candidate treatment targets for insomnia.

Characterization of middle ear soft tissue damping and its role in sound transmission.

Damping plays an important role in the middle ear (ME) sound transmission system. However, how to mechanically characterize the damping of ME soft tissues and the role of damping in ME sound transmission have not yet reached a consensus. In this paper, a finite element (FE) model of the partial external and ME of the human ear, considering both Rayleigh damping and viscoelastic damping for different soft tissues, is developed to quantitatively investigate the damping in soft tissues effects on the wide-frequency response of the ME sound transmission system. The model-derived results can capture the high-frequency (above 2 kHz) fluctuations and obtain the 0.9 kHz resonant frequency (RF) of the stapes velocity transfer function (SVTF) response. The results show that the damping of pars tensa (PT), stapedial annular ligament (SAL) and incudostapedial joints (ISJ) can help smooth the broadband response of the umbo and stapes footplate (SFP). It is found that, between 1 and 8 kHz, the damping of the PT increases the magnitude and phase delay of the SVTF above 2 kHz while the damping of the ISJ can avoid excessive phase delay of the SVTF, which is important in maintaining the synchronization in high-frequency vibration but has not been revealed before. Below 1 kHz, the damping of the SAL plays a more important role, and it can decrease the magnitude but increases the phase delay of the SVTF. This study has implications for a better understanding of the mechanism of ME sound transmission.

Origins of brain tissue elasticity under multiple loading modes by analyzing the microstructure-based models.

Constitutive behaviors and material properties of brain tissue play an essential role in accurately modeling its mechanical responses. However, the measured mechanical behaviors of brain tissue exhibit a large variability, and the reported elastic modulus can differ by orders of magnitude. Here we develop the micromechanical models based on the actual microstructure of the longitudinally anisotropic plane of brain tissue to investigate the microstructural origins of the large variability. Specifically, axonal fiber bundles with the specified configurations are distributed in an equivalent matrix. All micromechanical models are subjected to multiple loading modes, such as tensile, compressive, and shear loading, under periodic boundary conditions. The predicted results agree well with the experimental results. Furthermore, we investigate how brain tissue elasticity varies with its microstructural features. It is revealed that the large variability in brain tissue elasticity stems from the volume fraction of axonal fiber, the aspect ratio of axonal fiber, and the distribution of axonal fiber orientation. The volume fraction has the greatest impact on the mechanical behaviors of brain tissue, followed by the distribution of axonal fiber orientation, then the aspect ratio. This study provides critical insights for understanding the microstructural origins of the large variability in brain tissue elasticity.

Mechanical mechanism and indicator of diffuse axonal injury under blast-type acceleration.

Diffuse axonal injury (DAI) caused by acceleration is one of the most prominent forms of blast-induced Traumatic Brain Injury. However, the mechanical mechanism and indicator of axonal deformation-induced injury under blast-type acceleration with high peak and short duration are unclear. This study constructed a multilayer head model that can reflect the response characteristics of translational and rotational acceleration (the peak time of which is within 0.5 ms). Based on von Mises stress, axonal strain and axonal strain rate indicators, the physical process of axonal injury is studied, and the vulnerable area under blast-type acceleration load is given. In the short term (within 1.75 ms), dominated by sagittal rotational acceleration peaks, the constraint of falx and tentorium rapidly imposes the inertial load on the brain tissue, resulting in a high-rate deformation of axons (axonal strain rate of which exceed 100 s-1). For a long term (after 1.75 ms), fixed-point rotation of the brain following the head causes excessive distortion of brain tissue (von Mises stress of which exceeds 15 kPa), resulting in a large axonal stretch strain where the main axonal orientation coincides with the principal strain direction. It is found that the axonal strain rate can better indicate the pathological axonal injury area and coincides with external inertial loading in the risk areas, which suggests that DAI under blast-type acceleration overload is mainly caused by the rapid axonal deformation instead of by the excessive axonal strain. The research in this paper helps understand and diagnose blast-induced DAI.

Preparation, characterization and application of pH-responsive smart film based on chitosan/zein and red radish anthocyanin.

This research was aimed at developing a novel pH-responsive smart film made of chitosan, zein and red radish anthocyanin (RRA). The morphology, interaction, crystallization, thermal stability, physiochemical properties and pH sensitivity of films were analyzed. The smart film was applied to monitor the freshness of mushroom (Agaricus bisporus). The results of morphology (SEM) and spectrum (FT-IR and XRD) indicated that the incorporation of RRA could enhance the interaction between polymer matrix. The addition of RRA had no significant effect on the thermal stability of films. The chitosan/zein/red radish anthocyanin (C/Z/R) films exhibited higher tensile strength, Young's modulus, hydrophobicity, antioxidant activity and lower elongation at break. The C/Z/R films had stronger water vapor and gas barrier capacity. The C/Z/R films showed a pH-sensitive color variation from red (pH 2) to green (pH 12) and good reversibility under alkaline and acidic environment. The prepared smart film could be successfully used for the quality monitoring of mushroom.

A Bayesian method with nonlinear noise model to calibrate constitutive parameters of soft tissue.

The measured mechanical responses of soft tissue exhibit large variability and errors, especially for the softest brain tissue, while calibrating its constitutive parameters in a deterministic way remains a common practice. Here we implement a Bayesian method considering the nonlinear noise model to calibrate constitutive parameters of brain tissue. A probability model is first developed based on the measured experimental data, likelihood function, and prior function, from which the posterior distributions of model parameters are formulated. The likelihood function considers the nonlinear behaviors of the constitutive response and noise distribution of the experimentally measured data. Meanwhile, the prior predictive distribution is computed to check the probability model preliminarily. Secondly, the Markov Chain Monte Carlo (MCMC) method is used to compute the posterior distributions of model parameters, enabling assessment of parameter uncertainty, correlation, and model calibration error. Finally, the posterior predictive distributions of the overall response, constitutive response, and noise response are computed to validate the probabilistic model, all of which are consistent with the corresponding data. Furthermore, the effect of the prior distribution, experimental data, and noise model on posterior distribution is studied. Our study provides a general approach to calibrating constitutive parameters of soft tissue despite errors and large variability in experimental data.

Experimentally characterizing the spatially varying anisotropic mechanical property of cancellous bone via a Bayesian calibration method.

Traditional experimental tests for characterizing bone's mechanical properties usually hypothesize a uniaxial stress condition without quantitatively evaluating the influence of spatially varying principal material orientations, which cannot accurately predict the mechanical properties distribution of bones in vivo environment. In this study, a Bayesian calibrating procedure was developed using quantified multiaxial stress to investigate cancellous bone's local anisotropic elastic performance around joints as the spatial variation of main bearing orientations. First, the bone cube specimens from the distal femur of sheep are prepared using traditional anatomical axes. The multiaxial stress state of each bone specimen is calibrated using the actual principal material orientations derived from fabric tensor at different anatomical locations. Based on the calibrated multiaxial stress state, the process of identifying mechanical properties is described as an inverse problem. Then, a Bayesian calibration procedure based on a surrogate constitutive model was developed via multiaxial stress correction to identify the anisotropic material parameters. Finally, a comparison between the experiment and simulation results is discussed by applying the optimal model parameters obtained from the Bayesian probability distribution. Compared to traditional uniaxial methods, our results prove that the calibration based on the spatial variation of the main bearing orientations can significantly improve the accuracy of characterizing regional anisotropic mechanical responses. Moreover, we determine that the actual mechanical property distribution is influenced by complicated mechanical stimulation. This study provides a novel method to evaluate the spatially varying mechanical properties of bone tissues enduring complex mechanical loading accurately and effectively. It is expected to provide more realistic mechanical design targets in vivo for a personalized artificial bone prosthesis in clinical treatment.