Matrix Content Research Articles

Analytical modeling and experimental estimation of the dynamic mechanical characteristics of green composite: Caesalpinia decapetala seed reinforcement

AbstractThe emerging need for a sustainable environment prompts the research community to develop functional materials with bio‐ and organic waste. This research advocates biodegradable waste management and its performance evaluation. The involvement of Caesalpinia decapetala (CD) as a potential reinforcement in the epoxy matrix and its analytical evaluation of thermal stability are novel ideas for disposing of bio and organic waste. Three different variants (10, 20, and 30 wt%) of CD seed particles are used to develop the epoxy composite, and further, their influence on dynamic mechanical characteristics such as damping type, loss modulus, and storage modulus has been investigated. The results corroborate that the higher CD seed content (30 wt%) in the epoxy matrix enhances the storage modulus, loss modulus, and damping on a scale of 1.14, 1.25, and 1.07 times that of the neat epoxy matrix. The reason behind the improved dynamic properties has been validated through theoretical modeling. A substantial increment in the degree of entanglement and activation energy in the band of 8.33 × 10−3 moles/m3 and 20.201 kJ/mol, respectively, in comparison with neat epoxy, is considered to be good authentication for the thermal stability of the CD 30 specimen. The analytical prediction of storage modulus is executed with five different models, whereas damping behavior is executed with two different models. The analytically estimated results are matched with the experimental ones, and we conclude that they are in fair agreement with the experimental findings.

Mixed cropping enhances the nitrogen and phosphorus purification efficiency of sewage in wetland ecosystems

Although the water purification performance of individual species and their removal mechanisms have been thoroughly documented, the potential enhancement of sewage nitrogen and phosphorus removal rates through the combined effects of different plant species has yet to be comprehensively investigated. This study opted for Canna indica and Thalia dealbata, two characteristic wetland plants from the Three Gorges Reservoir Area, as the test subjects. The impact of cropping patterns (single-cropping and mixed-cropping) on the efficiency of nitrogen and phosphorus removal from sewage at varying concentrations was explored. The findings unveiled that the mixed-cropping pattern considerably heightened the total nitrogen (TN) absorption of plants in sewage environments, though it did not appreciably affect total phosphorus absorption. Moreover, sewage concentration influenced the nitrogen and phosphorus absorption patterns of plants, potentially exhibiting a threshold phenomenon. Mixed cropping significantly augmented the removal rates of sewage nitrogen and phosphorus. Under the single cropping arrangement, C. indica displayed superior pollutant removal performance in comparison to T. dealbata. Furthermore, the wetland plants significantly diminished the TN content of the soil matrix. The results indicated that the mixed planting pattern enhanced the purification efficiency of effluent nitrogen and phosphorus in the artificial wetland, probably due to the better purification by mixed species under competition for nutrients or the dilution effect of multiple species on effluent nitrogen and phosphorus nutrient salts following mixed planting. These results should guide planting selection for efficient and sustainable wastewater purification in wetland ecosystems.

Highly efficient solid phase extraction of uranium with TOPO-menthol based eutectic solvent as stationary phase from acidic feed relevant to front-end applications

Novel methods of separation and purification are envisaged for natural uranium, containing 0.7% of fissile 235U, a precious resource that fuels nuclear power plants. The present study demonstrates Solid phase extraction (SPE) of uranium as a sustainable alternative to conventional liquid-liquid extraction, leading to minimisation of organic inventory and enhancement of ease of operation concerning usage of viscous eutectic solvent. Overcoming the issue of the low solubility of organophosphorus extractant tri-octyl phosphine oxide (TOPO) in a hydrocarbon diluent, the aqueous insoluble, non-ionic eutectic solvent could be prepared with biodegradable menthol having TOPO: menthol mole ratio of 1:2 (MT2), 1:3 (MT3) and 1:4 (MT4). Eutectic solvents were sorbed on radio chemically stable Chromosorb W resin as solid support (MTC2, MTC3, MTC4), with loading of 45% for MTC2 and 40% for both MTC3 and MTC4, confirmed by weight difference and thermogravimetry. Batch sorption studies of U(VI) from nitric acid medium revealed attainment of equilibrium at 60 min., following a pseudo-second-order rate equation, Langmuir adsorption isotherm and a static capacity of 19 mg g−1. The U(VI) uptake was found to increase with the increase in acid molarity indicating solvating mechanism of extraction (KD = 1240 ± 4, 4 M HNO3). Recyclability was established and stripping was effective with 0.5 M HNO3. Column operation was also successfully demonstrated (breakthrough capacity = 18.9 mg g−1). The U(VI) uptake of >98% was indicated for nitric acid-digested crude yellow cake matrices viz. sodium diuranate (SDU), magnesium diuranate (MDU) and heat-treated uranium peroxide (HTUP). For higher matrix content, near complete uranium uptake and suppression of extraction of representative impurities (Fe, Mn, Ni, Ce) was revealed indicating facile uranium separation and purification from matrices relevant to the front end of the nuclear fuel cycle.

The Effect of Giving Human Umbilical Cord Mesenchymal Stem Cells (HUMSC) on the Expression of Collagen I in Menopause Model Mice

Background: Patients with pelvic floor dysfunction (PFD) who fail conservative treatment will undergo surgery. In recent years, various therapeutic approaches for PFD using stem cells have been investigated in vivo. One component of stem cells is the human umbilical cord mesenchymal stem cell (HUMSC). It is hoped that HUMSC can modify the collagen and elastin content in the extracellular matrix, leading to improvements in pelvic floor strength and PFD.
 Methods: This research is an experimental study with a randomized posttest-only controlled group design with the aim of determining the effect of giving HUMSC on the expression of Collagen I in a female mouse model of menopause. There are inclusion criteria, namely female Balb/c mice, healthy, never mated, aged 8 - 12 weeks, and body weight 18 - 22 grams. The research will be carried out with statistical analysis using SPSS; a p-value <0.05 is considered significant.
 Results: The results of the analysis of the distribution of sample means show that there are significant differences between the two groups. The treatment group had a higher mean expression of type I collagen compared to the control group. In addition, variation in the control group was lower compared with the treatment group, which could be interpreted as higher consistency in the response to HUMSC treatment.
 Conclusion: Human umbilical cord (HUMSC) has a positive impact on type I collagen expression in menopausal model mice.

How to enhance the ability of mesenchymal stem cells to alleviate intervertebral disc degeneration.

Intervertebral disc (ID) degeneration (IDD) is one of the main causes of chronic low back pain, and degenerative lesions are usually caused by an imbalance between catabolic and anabolic processes in the ID. The environment in which the ID is located is harsh, with almost no vascular distribution within the disc, and the nutrient supply relies mainly on the diffusion of oxygen and nutrients from the blood vessels located under the endplate. The stability of its internal environment also plays an important role in preventing IDD. The main feature of disc degeneration is a decrease in the number of cells. Mesenchymal stem cells have been used in the treatment of disc lesions due to their ability to differentiate into nucleus pulposus cells in a nonspecific anti-inflammatory manner. The main purpose is to promote their regeneration. The current aim of stem cell therapy is to replace the aged and metamorphosed cells in the ID and to increase the content of the extracellular matrix. The treatment of disc degeneration with stem cells has achieved good efficacy, and the current challenge is how to improve this efficacy. Here, we reviewed current treatments for disc degeneration and summarize studies on stem cell vesicles, enhancement of therapeutic effects when stem cells are mixed with related substances, and improvements in the efficacy of stem cell therapy by adjuvants under adverse conditions. We reviewed the new approaches and ideas for stem cell treatment of disc degeneration in order to contribute to the development of new therapeutic approaches to meet current challenges.

Heart Failure, Female Sex, and Atrial Fibrillation Are the Main Drivers of Human Atrial Cardiomyopathy: Results From the CATCH ME Consortium.

Atrial cardiomyopathy (atCM) is an emerging prognostic factor in cardiovascular disease. Fibrotic remodeling, cardiomyocyte hypertrophy, and capillary density are hallmarks of atCM. The contribution of etiological factors and atrial fibrillation (AF) to the development of differential atCM phenotypes has not been quantified. This study aimed to evaluate the association between histological features of atCM and the clinical phenotype. We examined left atrial (LA, n=95) and right atrial (RA, n=76) appendages from a European cohort of patients undergoing cardiac surgery. Quantification of histological atCM features was performed following wheat germ agglutinin/CD31/vimentin staining. The contributions of AF, heart failure, sex, and age to histological characteristics were determined with multiple linear regression models. Persistent AF was associated with increased endomysial fibrosis (LA: +1.13±0.47 μm, P=0.038; RA: +0.94±0.38 μm, P=0.041), whereas total extracellular matrix content was not. Men had larger cardiomyocytes (LA: +1.92±0.72 μm, P<0.001), while women had more endomysial fibrosis (LA: +0.99±0.56 μm, P=0.003). Patients with heart failure showed more endomysial fibrosis (LA: +1.85±0.48 μm, P<0.001) and extracellular matrix content (LA: +3.07±1.29%, P=0.016), and a higher capillary density (LA: +0.13±0.06, P=0.007) and size (LA: +0.46±0.22 μm, P=0.044). Fuzzy k-means clustering of histological features identified 2 subtypes of atCM: 1 characterized by enhanced endomysial fibrosis (LA: +3.17 μm, P<0.001; RA: +2.86 μm, P<0.001), extracellular matrix content (LA: +3.53%, P<0.001; RA: +6.40%, P<0.001) and fibroblast density (LA: +4.38%, P<0.001), and 1 characterized by cardiomyocyte hypertrophy (LA: +1.16 μm, P=0.008; RA: +2.58 μm, P<0.001). Patients with fibrotic atCM were more frequently female (LA: odds ratio [OR], 1.33, P=0.002; RA: OR, 1.54, P=0.004), with persistent AF (LA: OR, 1.22, P=0.036) or heart failure (LA: OR, 1.62, P<0.001). Hypertrophic features were more common in men (LA: OR=1.33, P=0.002; RA: OR, 1.54, P=0.004). Fibrotic atCM is associated with female sex, persistent AF, and heart failure, while hypertrophic features are more common in men.

Sedimentary texture differences between lithofacies types and their control on the physical property in fan-delta conglomerate reservoirs: A case study from the Triassic Baikouquan Formation in Mahu Sag, Junggar Basin, Northwestern China

Conglomerate reservoir developed in fan-delta environment is characterized by the diverse lithofacies types and strong heterogeneity. Lithofacies type is the main primary factor that controls the reservoir physical properties. However, quantitative sedimentary texture parameters of lithofacies types are scarcely studied, and their influence on the reservoir physical properties are still poorly understood. In this paper, lithofacies type, sedimentary texture and pore type, porosity and permeability of the Baikouquan Formation in Mahu Sag were studied to reveal the control of sedimentary texture parameters on the reservoir physical properties.The results showed that (1) lithofacies types in Baikouquan Formation can be classified into Gcm1, Gcm2, Gcm3, Gcm4, Gc, Sm1, Sm2, MSm, SSr, SSp and Mh; (2) different sorting coefficient and matrix content are present in Gcm, Gc, Sm1, Sm2 and MSm. These two texture parameters are highest in Sm2 and MSm, below Gcm and Gc, and the lowest in Sm1; (3) intra-gravel microfracture, gravel-edge microfracture and intra-matrix microfracture develop in conglomerates, which can improve their permeability; (4) porosity in Gcm, Gc, Sm1, Sm2 and MSm and permeability in Sm1, Sm2 and MSm have negative correlations with their sorting coefficient and matrix content. However, permeability in Gcm and Gc have poor correlations with these two texture parameters due to microfractures; (5) Gc and Sm1 have relatively high porosity and permeability due to their good sorting, low matrix content and consequently strong dissolution. By contrast, Gcm, Sm2 and MSm have relatively low porosity and permeability due to their bad sorting, high matrix content and consequently weak dissolution. These results indicate that Gc and Sm1 deposited in subaqueous distributary channels and lobes should be the first target in hydrocarbon exploration of fan-delta conglomerate reservoir.

Exploring the Biomedical Potential of PLA/Dysprosium Phosphate Composites via Extrusion-Based 3D Printing: Design, Morphological, Mechanical, and Multimodal Imaging and Finite Element Modeling.

The present investigation demonstrates the feasibility of dysprosium phosphate (DyPO4) as an efficient additive in polylactide (PLA) to develop 3D printed scaffolds through the material extrusion (MEX) principle for application in bone tissue engineering. Initially, uniform sized particles of DyPO4 with tetragonal crystal setting are obtained and subsequently blended with different concentrations of PLA to extrude in the form of filaments. A maximum of 20 wt % DyPO4 in PLA matrix has been successfully drawn to yield a defect free filament. The resultant filaments were 3D printed through material extrusion methodology. The structural and morphological analysis confirmed the successful reinforcement of DyPO4 throughout the PLA matrix in all of the 3D printed components. All of the PLA/DyPO4 composites exhibited magnetic resonance imaging and computed tomography contrasting properties, which were dependent on the dysprosium content in the PLA matrix. The detailed mechanical evaluation of the 3D printed PLA/DyPO4 composites ensured good strength accomplished by the reinforcement of 5 wt % DyPO4 in PLA matrix, beyond which a gradual decline in the strength is noticed. Representative volume elements models were developed to realize the intrinsic property of the PLA/DyPO4 composite, and finite element analysis under both static and dynamic loading conditions has been performed to account for the reliability of experimental results.

Advanced glycation and glycoxidation end products in bone.

Hyperglycemia and oxidative stress, enhanced in diabetes and aging, result in excessive accumulation of advanced glycation and glycoxidation end products (AGEs/AGOEs) in bone. AGEs/AGOES are considered to be "the missing link" in explaining increased skeletal fragility with diabetes, aging, and osteoporosis where increased fracture risk cannot be solely explained by bone mass and/or fall incidences. AGEs/AGOEs disrupt bone turnover and deteriorate bone quality through alterations of organic matrix (collagen and non-collagenous proteins), mineral, and water content. AGEs and AGOEs are also associated with bone fragility in other conditions such as Alzheimer's disease, circadian rhythm disruption, and cancer. This review explains how AGEs and AGOEs accumulate in bone and impact bone quality and bone fracture, and how AGES/AGOEs are being targeted in preclinical and clinical investigations for inhibition or removal, and for prediction and management of diabetic, osteoporotic and insufficiency fractures.

Silk-hydrogel functionalized with human decellularized Wharton's jelly extracellular matrix as a minimally invasive injectable hydrogel system for potential nucleus pulposus tissue replacement therapy

Intervertebral disc degeneration is a primary cause for chronic low back pain, a common health problem with high incidence and the leading cause of disability globally. The early stages of disc degeneration in terms of functional and anatomical abnormalities start from the central nucleus pulposus tissue of the intervertebral disc; hence its regeneration has become a prime concern. A plethora of hydrogel systems have been investigated as nucleus pulposus tissue substitute over the years, with limited clinical translation. In the present study, we formulated a minimally invasive injectable cross-linker-free bioactive silk-based hybrid hydrogel system functionalized with decellularized human Wharton's jelly extracellular matrix as an ampule of bioactive cues. The centrifugation based decellularization method removed >92 % of cellular components and preserved >83 % of extracellular matrix composition. The hydrogels were investigated for secondary structure and surface properties through infrared spectroscopy and electron micrographs, respectively. Notably, the developed hydrogels were found to mimic the rheological and mechanical properties of native nucleus pulposus tissue when decellularized Wharton's jelly extracellular matrix content was 0.5 % (w/v) in the base silk hydrogel. Finally, the hydrogels were found to support cell viability, proliferation, and tissue maturation offering great potential for future applications related to nucleus pulposus tissue engineering.

Pengaruh Inklusi Karet dan Semen yang Mengandung Graphene Oxide terhadap Perilaku Sifat Fisis dan Mekanis Tanah

Improving the physical properties of problematic soil has became fundamental consideration in various constructions, especially geotechnical engineering, to avoid failures, increase stability and strength of soil. Silty sand is one of the problematic soils and often encountered in the field where the fine gradation contained in the soil allows the soil to easily deform under pressure and lateral forces. In this study, silty sand was mixed with three variations of crumb rubber content (5, 10, and 15% based on soil weight), 6% cement (based on soil weight), and 0.05% graphene oxide (based on cement weight) to measurement and analysis of physical and mechanical properties. Soil Consistency limits, compaction testing using the Proctor Apparatus, and direct shear test were carried out for each mixed variable. The test results showed that the consistency limits and dry density decreases with increasing rubber content in the soil-cement matrix containing graphene oxide. Substitution of graphene oxide into the soil-cement matrix was able to increase in the stress and shear strength of the soil at each in variation in rubber content.

Construct and criterion validity of muscle ultrasonography for assessment of skeletal muscle in patients recovering from COVID-19.

Background: The purpose was to investigate the content, construct, and criterion validity of muscle ultrasound in a mixed cohort of participants recovering from mild and critical COVID-19. Methods: A secondary analysis of a prospective cross-sectional study was conducted on data obtained from a battery of muscle and physical function assessments including a muscle biopsy and muscle ultrasonography (US). Rectus femoris (RF) muscle thickness (mT), quadricep complex (QC) mT, RF muscle cross-sectional area (CSA) using 2D freeform trace and estimated from Feret's diameter, and RF echo intensity (EI) were assessed with US. Muscle fiber CSA, fiber type, protein content in muscle fibers, extracellular matrix content (ECM; wheat-germ agglutin), and percent area of collagen in ECM (picrosirius red) were examined from vastus lateralis muscle biopsies. Spearman rho correlations (r) were performed to assess validity of ultrasound parameters. Results: Thirty-three individuals participated including 11 patients surviving critical COVID-19, 15 individuals recovering from mild-COVID, and 7 controls. There were several significant correlations between RF mT, QC mT, RF CSA, and RF EI with age, comorbid burden, body-mass index, and measures of muscle strength, muscle power, and physical function (range r = 0.35-0.83). RF Feret's CSA correlated to CSA of type II muscle fibers (r = 0.41, p = 0.022) and the average size of all muscle fibers (r = 0.39, p = 0.031). RF EI was correlated with collagen in muscle ECM (r = 0.53, p = 0.003) and protein content in muscle tissue (r = -0.52, p = 0.012). Conclusion: Muscle size and quality measured using US has moderate content and construct validity, and to lesser extent, fair to moderate criterion validity in a mixed cohort of individuals recovering from COVID. Muscle ultrasound quality (EI) appears to be sensitive at detecting muscle dysfunction as it is associated with strength, power, physical function, and collagen distribution in a mixed group of individuals recovering from COVID-19.

A thermodynamic approach for preparing oxide dispersion–strengthened Ti-6Al-4V powder by in situ gas atomization method

This study examined the feasibility of in situ fabrication of oxide dispersion–strengthened (ODS) Ti-6Al-4V (Ti64) powder through a gas atomization (GA) method. Thermodynamic calculations were performed to design the ODS Ti64 by deriving compositions of yttrium oxide (Y2O3), which is completely dissolved into the molten Ti64 and subsequently reprecipitated during cooling in the GA process. In addition, the changes in the equilibrium phase fractions based on varying the Y2O3 content and oxygen (O) concentration in the Ti64 matrix were investigated. From the thermodynamic calculations, an optimal composition for the ODS Ti64 alloy was determined, involving the addition of 1 wt% Y2O3 to Ti64 with an O concentration of 0.1 wt%. The alloy ingot was prepared via vacuum arc remelting, leading to the precipitation of coarse Y2O3 along grain boundaries because of a slow cooling rate. The ODS Ti64 powder was fabricated through an electrode induction melting GA method, and the resulting ODS Ti64 powder had spherical morphology, with uniformly distributed Y2O3 particles of several tens of nanometers in size. The hardness of a conventional Ti64 powder was 354 HV, significantly increasing to 485 HV in the ODS Ti64 powder due to the Y2O3 nanoparticles’ dispersion. This study introduces a novel methodology for fabricating high-quality ODS Ti64 powder by the in situ GA method.

Effects of maleic anhydride on the moisture crosslinking of EVM‐GMA grafted with amino silane

AbstractMoisture crosslinking would be a good substitution to cure ethylene‐vinyl acetate‐glycidyl methacrylate rubber (EVM‐GMA) due to the characteristics of low cost and environmental friendliness. Our previous study found amino silane grafted onto EVM‐GMA with low degree due to the low epoxy group content in rubber matrix. Consequently, the moisture crosslinking density of rubber compound is low. So, it is necessary to find an effective method to improve the moisture crosslinking density of EVM‐GMA. In this paper, EVM‐GMA grafted with γ‐aminopropyltriethoxysilane and maleic anhydride (EVM‐GMA‐g‐APTES/MAH) composites were prepared by melt blending, and then the moisture crosslinking of composites was achieved in a 90°C water bath with the aid of catalyst dibutyltin dilaurate (DBTL). The grafting of MAH onto the EVM‐GMA molecular chain and its reaction with amino silane were confirmed by differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FT‐IR). Furthermore, the moisture crosslinking density of the samples before and after grafting MAH was compared. The results indicated that the moisture crosslinking density of the grafted MAH was higher than that of the unmodified rubber, thus achieving better overall mechanical properties. Therefore, grafting MAH was a feasible way to improve the moisture crosslinking density of EVM‐GMA with the existence of silane.

Degradation mechanisms of polyurethane grouting materials under quasi-static and cyclic compression loading: Density and size effects

Foamed polyurethane (PU) grouting materials are widely used for road trenchless rehabilitation. However, the density and size effects on their mechanical properties and the microscopic mechanisms under quasi-static and cyclic compression are still unclear. In this paper, the degradation mechanisms of PU grouting materials with different densities and specimen sizes were studied by quasi-static compression, cyclic compression, and macro–micro morphological characterization. As the specimen diameter increased, the compressive strength decreased and the elastic modulus increased. As the diameter-to-height ratio increased, the compressive strength increased and the elastic modulus decreased. The compressive strength/elastic modulus increased as a power function with density. When the stress levels were above the fatigue threshold, cyclic failure occurred. When the stress level reached the fatigue threshold, the loading rate, elastic strain, and loss factor were concentrated at 0.25 s−1, 0.013, and 0.023, respectively. The initial dynamic stiffness increased by 55.94 % compared to the quasi-static stiffness. The fatigue threshold tended to decrease with the increasing specimen diameter and diameter-to-height ratio. For specimens with D20H20, the density effect on the fatigue threshold was not significant. For specimens with D40H80 and D40H40, the fatigue threshold decreased with increasing density. Density and size effects were due to the combined effects of relative skin thickness, cell structure, and matrix content. Moreover, the S-N curve was established.

Nanocomposites Based on Polyethylene and Nickel Ferrite: Preparation, Characterization, and Properties.

Composite materials based on NiFe2O4 nanoparticles and polyethylene matrix have been synthesized by thermal decomposition to expand the application area of high-pressure polyethylene by filling it with nanoscale particles. The synthesized compositions were obtained in the form of a dark gray powder and compressed for further study According to TEM, the average particle size in composites was 2, 3, and 4 nm in samples with a filling of 10%, 20% and 30%. The concentration dependences of the specific electrical resistivity ρV, dielectric permittivity ε, saturation magnetization MS and the parameters of reflection and attenuation of microwave power of the obtained composites were investigated. The threshold for percolation in such materials is found to be within a concentration range of 20…30%. The electronic and atomic structure of composites was studied by methods of Mössbauer spectroscopy, X-ray diffraction and X-ray absorption spectroscopy. The closest atomic environment of nickel and iron in nanoparticles is close to that of crystalline NiFe2O4. The dependence of the nanoparticles size as well as the dependence of the number of tetrahedral or octahedral iron positions in nickel ferrite nanoparticles to their content in polyethylene matrix is established. It is shown that composite materials based on NiFe2O4 nanoparticles and polyethylene matrix can be used as components of electromagnetic compatibility systems.

Effects of prenatal acetaminophen exposure at different stages, doses and courses on articular cartilage of offspring mice.

Previous studies showed that chondrodysplasia has intrauterine origin. Although prenatal acetaminophen exposure (PAcE) can cause nervous and reproductive abnormalities in offspring, its effect on cartilage is uninvestigated. Herein, mice were treated with different doses and courses of acetaminophen at various gestational stages (100 or 400mg/kg∙d on gestational days 10-12 (GD10-12), 400mg/kg∙d on GD12 or GD15-17) based on clinical administration and conversion between humans and mice. Fetal knee joints were harvested on GD18 to analyze cartilage morphology, chondrocyte proliferation and apoptosis, and matrix content, synthesis and degradation. Results showed that 400mg/kg∙d acetaminophen exposure during GD10-12 decreased chondrocyte numbers, safranin O staining, proliferation and matrix synthesis, without elevating matrix degradation and apoptosis. Low-dose, single-course, or late-pregnancy exposure had no effect on above indexes. Moreover, Tgfβ pathway was inhibited, showing a positive correlation with the expression of Col2a1, Acan, Ki67, and Pcna. Overall, clinical doses of PAcE can inhibit chondrocyte proliferation and matrix synthesis, causing fetal mice chondrodysplasia, especially after multi-course exposure of 400mg/kg∙d acetaminophen during GD10-12, the mechanism of which might involve Tgfβ pathway inhibition. This study provides an experimental basis for assessing fetal developmental toxicity and standardizing the clinical use of acetaminophen during pregnancy.

Lipid nanoparticles containing coenzyme Q10 for topical applications: An overview of their characterization.

The coenzyme Q10 is a compound widely used in pharmaceutical and cosmetic formulations because it is a potent eliminator of free radicals, giving it antioxidant and anti-aging properties. It is naturally synthesized by the human body, but its production wanes with age, leading to the formation of wrinkles. The efficacy of topical application of the coenzyme to counteract this process is subject to several difficulties, due to its instability in the presence of light, low solubility in water and high lipophilicity. Because of these drawbacks, many studies have been conducted of release systems. Lipid nanoparticles stand out in this sense due to the advantages of skin compatibility, protection of the active ingredient against degradation in the external medium, capacity to increase penetration of that ingredient in the skin, and its controlled and prolonged release. In this context, this article presents a review of the main studies of the coenzyme Q10 encapsulated in lipid nanoparticles for topical use, focusing on the analytic methods used to characterize the systems regarding morphology, zeta potential, release profile, Q10 content, encapsulation efficiency, crystalline organization and structure of the lipid matrix, rheology, antioxidant activity, skin penetration and efficacy, among other aspects. We also describe the main results of the different studies and discuss the critical aspects - the simplest, most reproducible, best, and most relevant - that characterize lipid nanoparticles with encapsulated Q10 for topical use.

Study of thermal and mechanical behavior by analyzing reinforcement effect of graphene nanoplatelets on polyamide-66 composite system developed via melt-mixing technique

In the present study, graphene nanoplatelets (GNP) reinforced polyamide 6,6 (PA-66) composite was studied to investigate the thermal and mechanical properties of PA-66/GNP composite. The composites were developed by varying wt% (1, 3, 5, and 10 wt%) of GNP loading using a co-rotating, intermeshing, twin-screw extruder via melt-mixing and injection molding process. In order to understand the thermal and mechanical behavior of PA-66/GNP composite, various thermal (TGA and DSC) and mechanical (tensile, impact, and flexural) tests were carried out. The FTIR spectral analysis was done to identify the presence of different functional groups in the PA-66/GNP composite, indicating the strong enough Vander-Waals interaction between the PA-66 matrix and GNP filler contents. The TGA result shows a significant enhancement in the thermal stability of the composite by increasing wt% of GNP. The DSC analysis exhibits a significant reduction in enthalpy of fusion (∆Hm) and a decrease in the degree of crystallinity with increasing wt% of GNP, reflecting a depressed form of α-crystalline structure. Further, the significant growth in tensile modulus and tensile strength were identified under the mechanical performance of the PA-66/GNP composite. An increasing trend in tensile modulus and tensile strength characteristics was observed, and tensile modulus exhibited an enhancement of ∼96% than pure PA-66 at 10 wt% of GNP. Also, the tensile strength is found to be ∼16% higher than that of pure PA-66 matrix. Similarly, the impact test result shows a decreasing trend in impact strength on increasing wt% of GNP reinforcements, indicating the restriction to the molecular mobility due to improved brittle behavior. Further, the flexural modulus is found to be increased by ∼28% at 10 wt%, and the flexural strength is found to have an enhancement of ∼9% at 3 wt% than pure PA-66 polymer matrix of GNP loadings, respectively. The influence of GNP filler content reinforced PA-66 composite on the thermal and mechanical properties is found to be noteworthy.

N-glycosylomic analysis provides new insight into the molecular mechanism of firmness of fish fillet.

Post-translational protein modification affects muscle physiochemistry. To understand the roles of N-glycosylation in this process, the muscle N-glycoproteomes of crisp grass carp (CGC) and ordinary grass carp (GC) were analyzed and compared. We identified 325N-glycosylated sites with the NxT motif, classified 177 proteins, and identified 10 upregulated and 19 downregulated differentially glycosylated proteins (DGPs). Gene Ontology and Kyoto Encyclopedia of Genes and Genomes annotations revealed that these DGPs participate in myogenesis, extracellular matrix content formation, and muscle function. The DGPs partially accounted for the molecular mechanisms associated with the relatively smaller fiber diameter and higher collagen content observed in CGC. Though the DGPs diverged from the identified differentially phosphorylated proteins and differentially expressed proteins detected in previous study, they all shared similar metabolic and signaling pathways. Thus, they might independently alter fish muscle texture. Overall, the present study provides novel insights into the mechanisms underlying fillet quality.