Immunomodulatory effect of gelatin-coated silver nanoparticles in mice: Ultrastructural evaluation

Silver nanoparticles (SNP) are used in many pharmaceutical, cosmetic, and industrial products already available in the market. Although they are considered relatively safe, many toxic and pathological alterations in different organs including immune organs were reported after SNP administration. In this study, 10-week-old male mice (n = 20) were divided into two groups. Ten mice received greenly synthesized gelatin-coated silver nanoparticles in a dose of 10 mg/kg body weight for five consecutive days while the other 10 received 0.5 ml of distilled water daily for 5 days and kept as control. At the sixth day, all mice were sacrificed; blood and tissue samples were collected and prepared for pathological analysis. Liver and kidney lesions were in the form of degenerative and inflammatory changes. Interestingly, the immune organs were drastically affected by SNP treatment. Severe hyperplasia of the Peyer’s patches was noticed in the intestines of intoxicated animals both in gross and microscopic examination. Spleen was enlarged and showed large number of megakaryocytes. The particles were encountered in membrane-bound phagosomes inside macrophages in different organs like lungs and spleen. Blood picture complied to morphological findings with an increase in monocytes and eosinophils accompanied by drop in the platelets count in the intoxicated animals.     

Validity of Three Brief Health Literacy Screeners to Measure Functional Health Literacy – Evidence from Five Different Countries

Self-reported health literacy measures have seen increased application throughout the last years, among those are the brief health literacy screeners (BHLS) developed by Chew and colleagues (2004). There has been little systematic research on the performance of these measures across different contexts, including countries and languages, to draw conclusions about their predictive power outside of the United States.

This study aimed at replicating the original validation of the BHLS. Receiver operating characteristic (ROC) analysis was applied to data from Hungary, Italy, Lebanon, Switzerland, and Turkey. In addition, logistic regression models incorporating ROC analysis using BHLS as predictors were compared to models using socio-demographics only to identify individuals with inadequate and inadequate or marginal health literacy as measured with the Short Test of Functional Health Literacy in Adults.

Analyses showed that in all cases the BHLS were not sufficiently able to identify individuals with different health literacy levels. Logistic regression models using socio-demographics only as predictors outperformed models using the BHLS.

The findings highlight the limitations of using the BHLS outside the United States. Further, they question in how far self-reported health literacy measures are comparable across different contexts and whether thresholds for different health literacy levels are universally applicable.     

The effect of long-term supplementation with different dietary ω-6/ω-3 ratios on mineral content and ex vivo prostaglandin E2 release in bone of growing rabbits

BACKGROUND/OBJECTIVES

The aim of this research was to study the different long term effects of consumption of dietary oil sources with varying omega-6/omega-3 (ω-6/ω-3) polyunsaturated fatty acids (PUFAs) ratios on bone marrow fatty acid level, ex vivo prostaglandin E₂ (PGE₂) release, and mineral content of bone in rabbits.

MATERIALS/METHODS

For this purpose, weaning and female New Zealand white rabbits were purchased and randomly divided into five groups and offered ad libitum diets containing 70 g/kg of added oil for 100 days. The dietary lipid treatments were formulated to provide the following ratios of ω-6/ω-3 fatty acids: 8.68 soy bean oil (SBO control), 21.75 sesame oil (SO), 0.39 fish oil (FO), 0.63 algae oil (DHA), and 0.68 algae oils (DHA/ARA). DHA and ARA are two types of marine microalgae of the genus Crypthecodinium cohnii.

RESULTS

The dietary treatments had significant effects on the bone marrow fatty acids of rabbits. Rabbits fed the FO diet, containing the highest ω-3 PUFA concentration, and those fed the SBO diet showed the highest ω-6 PUFA. On the other hand, a positive correlation was observed between Ex vivo PGE₂ level and the ω-6/ω-3 dietary ratio. Significant effects of dietary treatment on femur Ca, P, Mg, and Zn contents were observed in both genders.

CONCLUSIONS

Findings of the current study clearly demonstrated that dietary PUFA, particularly ω-6/ω-3 and ARA/EPA ratios are important factors in determining bone marrow fatty acid profile, and this in turn determines the capacity of bone for synthesis of PGE₂, thereby reducing bone resorption and improving bone mass during growth.     

Unbiased spontaneous solar hydrogen production using stable TiO2–CuO composite nanofiber photocatalysts

We report on the optimization of electrospun TiO₂–CuO composite nanofibers as low-cost and stable photocatalysts for visible-light photocatalytic water splitting. The effect of different annealing atmospheres on the crystal structure of the fabricated nanofibers was investigated and correlated to the photocatalytic activity of the material. The presence of CuO resulted in narrowing the bandgap of TiO₂ and shifting the absorption edge into the visible region of the light spectrum. The effect of incorporating CuO within TiO₂ nanofibers on the crystal structure and composition was also investigated using X-ray diffraction (XRD), electron paramagnetic resonance (EPR), and X-ray photoelectron spectroscopy (XPS) techniques. The fabricated TiO₂–CuO composite nanofibers showed 117% enhancement in the amount of hydrogen evolved during the photocatalytic water splitting process compared to pure TiO₂. This enhancement was related to the created shallow defect states that facilitate charge transfer from TiO₂ to CuO and distinct characteristics of the composite nanofibers, such as the high surface area and directional charge transfer. The study showed that Cu is a promising alternative to noble metals as a catalyst in photocatalytic water splitting, with the advantage of being an Earth abundant element and a relatively cheap material.

We report on the optimization of electrospun TiO₂–CuO composite nanofibers as low-cost and stable photocatalysts for visible-light photocatalytic water splitting.     

Application of DFT-based machine learning for developing molecular electrode materials in Li-ion batteries

In this study, we utilize a density functional theory-machine learning framework to develop a high-throughput screening method for designing new molecular electrode materials. For this purpose, a density functional theory modeling approach is employed to predict basic quantum mechanical quantities such as redox potentials, and electronic properties such as electron affinity, highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO), for a selected set of organic materials. Both the electronic properties and structural information, such as the numbers of oxygen atoms, lithium atoms, boron atoms, carbon atoms, hydrogen atoms, and aromatic rings, are considered as input variables for the machine learning-based prediction of redox potentials. The large-set of input variables are further downsized using a linear correlation analysis to have six core input variables, namely electron affinity, HOMO, LUMO, HOMO–LUMO gap, the number of oxygen atoms and the number of lithium atoms. The artificial neural network trained using the quasi-Newton method demonstrates a capability for accurately estimating the redox potentials. From the contribution analysis, in which the influence of each input on the target are accessed, we highlight that the electron affinity has the highest contribution to redox potential, followed by the number of oxygen atoms, HOMO–LUMO gap, the number of lithium atoms, LUMO, and HOMO, in order.

In this study, we utilize a density functional theory-machine learning framework to develop a high-throughput screening method for designing new molecular electrode materials.