Shape memory polymers are strong competitors against shape memory alloys in many similar applications due to their inherent properties. Numerous studies have already reported shape memory properties ...of pure and blended polymer systems. However, further research is required to address property–structure interplays in nano‐reinforced shape memory composites of low programming temperature with specialty applications including wearing smart cloths, advanced medical devices and biomedical shape memory scaffolds. This research aims to evaluate the overall interplay amongst thermal, structural and viscoelastic properties of nanoclay reinforced polylactic acid (PLA)/thermoplastic polyurethane (TPU) shape memory blends whilst the use of a plasticizer is hypothesized to modify the programming temperature of the fabricated parts. To achieve this, the melt mixing method was utilized in fabrication of nanoclay filled PLA/TPU blends of 60/40 ratio as the optimized reference system. Polyethylene glycol (PEG) was used to reduce the stimulation temperature down to around 42°C. The results showed that the optimal thermal, structural and shape memory properties are obtained when 5 wt% of nanoclay and 10 wt% of PEG are incorporated into the reference blend exhibiting the targeted stimulus temperature as supported by the thermal, structural and shape memory response of the parts. The contact angles, surface energy values and transmission electron microscopy analysis further confirmed the improvement in the miscibility of PLA/TPU blends correlated to the overall shape memory response of the fabricated parts.
Abstract
Gas hydrates are crystalline inclusion compounds formed by trapping gas molecules inside water cages at high pressures and low temperatures. Hydrates are promising materials for hydrogen ...storage, but their potential depends on understanding their mechanical properties. This work integrates density functional theory (DFT) simulations with a geometry-inspired composite material model to explore the bulk moduli of structure II hydrogen hydrates subjected to pressure loads of − 0.2 to 3 GPa, representative of the hydrogen hydrate formation conditions. Our findings reveal that structure II hydrate comprises a bi-continuous composite of small and large cages with nearly equal volume fractions. The bulk modulus increases with rising pressure but decreases with increasing composition. Notably, these results align closely with the ideal laws of mixtures, especially at low pressures and compositions, where cage interactions are minimal. This integrated DFT-laws of mixtures methodology provides a key database for fast estimation of hydrate mechanical properties without costly computations.
The dynamics of tumor growth and associated events cover multiple time and spatial scales, generally including extracellular, cellular and intracellular modifications. The main goal of this study is ...to model the biological and physical behavior of tumor evolution in presence of normal healthy tissue, considering a variety of events involved in the process. These include hyper and hypoactivation of signaling pathways during tumor growth, vessels’ growth, intratumoral vascularization and competition of cancer cells with healthy host tissue. The work addresses two distinctive phases in tumor development—the avascular and vascular phases—and in each stage two cases are considered—with and without normal healthy cells. The tumor growth rate increases considerably as closed vessel loops (anastomoses) form around the tumor cells resulting from tumor induced vascularization. When taking into account the host tissue around the tumor, the results show that competition between normal cells and cancer cells leads to the formation of a hypoxic tumor core within a relatively short period of time. Moreover, a dense intratumoral vascular network is formed throughout the entire lesion as a sign of a high malignancy grade, which is consistent with reported experimental data for several types of solid carcinomas. In comparison with other mathematical models of tumor development, in this work we introduce a multiscale simulation that models the cellular interactions and cell behavior as a consequence of the activation of oncogenes and deactivation of gene signaling pathways within each cell. Simulating a therapy that blocks relevant signaling pathways results in the prevention of further tumor growth and leads to an expressive decrease in its size (82% in the simulation).
In vitro rooting as one of the most critical steps of micropropagation is affected by various extrinsic (e.g., medium composition, auxins) and intrinsic factors (e.g., species, explant). In ...Passiflora species, in vitro adventitious rooting is a difficult, complex, and non-linear process. Since in vitro rooting is a multivariable complex biological process, efficient and reliable computational approaches such as machine learning (ML) are required to model, predict, and optimize this non-linear biological process. Therefore, in the current study, a hybrid of generalized regression neural network (GRNN) and genetic algorithm (GA) was employed to predict in vitro rooting responses (rooting percentage, number of roots, and root length) of Passiflora caerulea based on the optimization of the level of auxins (indole-3-acetic acid (IAA), indolebutyric acid (IBA), and 1-naphthaleneacetic acid (NAA)) and the type of explant (microshoots derived from leaf, node, and internode). Based on the results, the GRNN model was accurate in predicting all in vitro rooting responses of P. caerulea (R2 > 0.92) in either training or testing sets. The result of the validation experiment also showed that there was a negligible difference between the predicted-optimized values and the validated results demonstrating the reliability of the developed GRNN-GA model. Generally, the results of the current study showed that GRNN-GA is a reliable and accurate model to predict and optimize in vitro rooting of P. caerulea.
Objectives
Computational modeling of biological systems is a powerful tool to clarify diverse processes contributing to cancer. The aim is to clarify the complex biochemical and mechanical ...interactions between cells, the relevance of intracellular signaling pathways in tumor progression and related events to the cancer treatments, which are largely ignored in previous studies.
Materials and Methods
A three‐dimensional multiscale cell‐based model is developed, covering multiple time and spatial scales, including intracellular, cellular, and extracellular processes. The model generates a realistic representation of the processes involved from an implementation of the signaling transduction network.
Results
Considering a benign tumor development, results are in good agreement with the experimental ones, which identify three different phases in tumor growth. Simulating tumor vascular growth, results predict a highly vascularized tumor morphology in a lobulated form, a consequence of cells' motile behavior. A novel systematic study of chemotherapy intervention, in combination with targeted therapy, is presented to address the capability of the model to evaluate typical clinical protocols. The model also performs a dose comparison study in order to optimize treatment efficacy and surveys the effect of chemotherapy initiation delays and different regimens.
Conclusions
Results not only provide detailed insights into tumor progression, but also support suggestions for clinical implementation. This is a major step toward the goal of predicting the effects of not only traditional chemotherapy but also tumor‐targeted therapies.
The model simulates the tumor development processes at intracellular, cellular, and extracellular scales. A diagram of the different events at each scale is shown. The extracellular scale describes tumor growth associated with angiogenesis, by calculating the diffusion of VEGF, nutrients, and the therapeutic drugs. The environmental conditions activate receptors' prompting signaling cascades inside cells, and, consequently, the behavior of each cell is predicted at the intracellular scale. The interaction between cells of different phenotypes is described at the cellular level.
Rheumatoid Arthritis (RA) is an autoimmune disease. The aim of this study was to investigate the effect of ginger supplementation on the expression of some immunity and inflammation intermediate ...genes in patients who suffer from RA.
In this randomized double-blind placebo-controlled clinical trial, seventy active RA patients were allocated randomly into two groups who either received 1500 mg ginger powder or placebo daily for 12 weeks. Disease activity score and gene expression of NF-κB, PPAR-γ, FoxP3, T-bet, GATA-3, and RORγt as immunity and inflammation intermediate factors were measured using quantitative real-time PCR before and after the intervention.
After the intervention, FoxP3 genes expression increased significantly within ginger group and between the two groups (P-value = 0.02). Besides, T-bet and RORγt genes expression decreased significantly between the two groups (P-value < 0.05). In ginger group, PPAR-γ genes expression increased significantly (P-value = 0.047) but the difference between the two groups wasn't statistically significant (P-value = 0.12). The reduction in disease activity score was statistically significant within ginger group and between the two groups after the intervention.
It seems that ginger can improve RA by decreasing disease manifestations via increasing FoxP3 genes expression and by decreasing RORγt and T-bet genes expression.
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•In the current study, after the intervention the FoxP3 genes expression increased significantly within ginger group and between the two groups (P-value= 0.02).•Besides, T-bet and RORγt genes expression decreased significantly between the two groups (P-value <0.05).•In ginger group, PPAR-γ genes expression increased significantly (P-value = 0.047) but the difference between the two groups was not statistically significant (P-value = 0.12).•The reduction in disease activity score was statistically significant within ginger group and between the two groups after the intervention.
Aim: The purpose of this study was to evaluate the effect of 50 and 100 mg doses of green cumin essential oil on glycemic and inflammatory indices in patients with diabetes type II. Method: In this ...randomized double-blind placebo-controlled clinical trial, subjects were divided into three groups after selecting them randomly according to the inclusion criteria: 1 - Cuminum cyminum capsule (100 mg/day,n = 33), 2 - C. cyminum capsule (50 mg/day, n = 33), and 3 - placebo (n = 33). Before and after 8 weeks of intervention, a blood sample was taken. Findings: The findings demonstrated that the mean of the FBS, glycosylated hemoglobin (HgA1c) and the serum levels of insulin were significantly decreased and insulin sensitivity (HOMA-IR) was significantly increased in the groups receiving the 100 mg supplement (P ＜ 0.001) and 50 mg supplement, but these indices were increased in the placebo group. The mean serum levels of TNF-α and hsCRP were significantly decreased, and serum levels of adiponectin was significantly increased at the end of the study in the groups receiving 100 mg (P ＜ 0.001) and 50 mg (P = 0.008) supplement as well as in the group who received the placebo. There were no significant change in HOMA-B and QUICKI as insulin resistance parameters. Discussion and conclusion: Administering C. cyminum supplement in patients with diabetes type II may decrease the serum levels of insulin, FBS, and glycosylated hemoglobin and also the inflammatory indices of TNF-α and hsCRP and increased the serum levels of adiponectin. In addition it may control the complications of diabetes type II in these patients.
Coenzyme Q10 (CoQ10) has been known as ubiquinone or ubidecarenone, which is a kind of lipid-soluble and vitamin-like antioxidant. It has a potent antioxidant effect against oxidation status via ...various mechanisms, including its ability to regenerate other antioxidants, such as vitamin E and vitamin C, and to increase antioxidant enzymes. Moreover, CoQ10 can quench free radicals and prevent lipid peroxidation. The aim of this systematic review and meta-analysis was to evaluate the effect of CoQ10 on oxidative stress variables.
A comprehensive electronic database search in Scopus, Web of Science, Embase, Cochrane Library, and Medline was performed to identify eligible randomized clinical trials. A meta-analysis of included studies was performed on selected variables using a random-effects model. Quality assessment was conducted by means of the Cochrane risk of bias assessment tool.
To evaluate the effect of CoQ10 supplementation, 17 trials and 972 participants were included for the meta-analysis. The pooled analysis of primary studies showed that CoQ10 increased serum total antioxidant capacity (standardized mean difference SMD 0.62 mmol/L, 95% CI 0.18-1.05, I2 = 76.1%, p ˂ 0.001) and superoxide dismutase (SMD 0.40 U/mg, 95% CI 0.12-0.67, I2 = 9.6%, p ˂ 0.345) levels and decreased malondialdehyde (SMD -1.02 mmol/L, 95% CI -1.60 to -0.44, I2 = 88.2%, p ˂ 0.001) level significantly compared to the placebo group. Although the effect of CoQ10 on nitric oxide (SMD 1.01 µmol/L, 95% CI -1.53 to 3.54, p ˂ 0.001, I2 = 97.8%) and glutathione peroxidase (SMD -0.01 mmol/L, 95% CI -0.86 to 0.84, p ˂ 0.001, I2 = 88.6%) was not significant, CoQ10 can be mentioned as an improvement in antioxidant defense status against reactive oxygen species.
These supplements have positive effects on antioxidant defense against oxidizing agents and elevate antioxidant enzyme levels in the body. However, due to limited research the results should be taken with caution.
In this study, we investigate the composition-dependent mechanical properties and elastic anisotropies of sII hydrogen hydrates using first-principles method. The evaluation of the elastic moduli and ...their direction dependency is achieved by computing the second-order elastic constants (SOECs) of the unit lattice. The various trends of elastic constants with the hydrogen composition of the cages introduces variations in the bonding strength, compressibility, stiffness, and shear properties of the structure which are captured by the Poisson's ratio, bulk, Young, and shear moduli, respectively. Elastic properties were found to be significantly influenced by the system's anisotropy, arising from the geometry of the cages and their unique arrangement within the lattice being affected by the increase in the hydrogen occupancy of the cages. The detailed analysis of elastic anisotropies revealed shifts in the strongest and weakest directions of the material with varying the hydrogen content of the cages. The Poisson's ratio captures the anisotropic bonding strengths within the crystal structure with the hydrogen composition of the lattice, explaining the reason behind the existence of strongest and weakest directions in terms of compression, tension, and shear forces. Taken together the established structure-property-composition relations will be useful in the design and optimization of hydrogen sII hydrates for energy storage applications.
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