Effect of Aspergilus oryzae-fermented broken rice, brewers’ rice and rice bran on melanogenesis in highly pigmented human melanoma, MNT-1

The food and beauty sectors are developing strategies to establish a link between nutrient consumption and skin health, as nutraceuticals offer a promising treatment option for some skin disorders such as hyperpigmentation and premature ageing. As a result, the consumption of food ingredients and supplements claiming to lower the risk of developing such skin problems is increasing. In this study, anti-tyrosinase potential of Aspergillus oryzae-fermented rice by-product water extracts namely fermented broken rice (FBR), brewers’ rice (FBrR), and rice bran (FRB) was assessed through in vitro study using highly pigmented human melanoma MNT-1 cells. The fermented extracts were evaluated for cytotoxicity, anti-tyrosinase activity using intracellular tyrosinase assay as well as melanin content analysis. Their effect on the gene expression of three melanogenic enzymes: tyrosinase (TYR), tyrosinase-related protein-1 (TRP-1) and tyrosinase-related protein 2 (TRP-2) was also assessed by qPCR analysis. As a result, all extracts at tested concentrations of 50 and 100 µg/mL have a low cytotoxicity effect. Together with the positive control kojic acid, the FBR at both concentrations and the FRB at 50 µg/mL significantly decreased intracellular tyrosinase activity. However, their melanin content was not significantly reduced. The qPCR analysis indicated that FBR at 50 and 100 µg/ mL significantly reduced TYR gene expression by up to 71% and 61%, respectively. On the other hand, FBR (100 µg/mL) increased TRP-1 gene expression, whilst FRB (100 µg/ mL) elevated both TRP-1 and TRP-2 gene expression. The positive control kojic acid significantly reduced TYR, TRP-1 and TRP-2 gene expression. However, FBrR demonstrated no significant effect in any of the analyses. Based on these findings, FBR and FRB at 50 µg/mL possess anti-tyrosinase potential. However, further investigation is needed to dissect deeper mechanisms underlying their potential as functional bioingredients for nutraceutical or cosmeceutical applications.

The effect of heat treatments on the bioactive compounds, antioxidant activity, and cosmeceutical properties (anti-pigmentation and anti-ageing) of fermented broken rice

Previously, broken rice was subjected to solid-state fermentation using locally isolated Aspergillus oryzae under optimised conditions. The fermented broken rice (FBR) has shown great promise as a bioingredient in the formulation of health foods and cosmeceutical products. However, the effects of heat treatment on the bioactive compound content and biological activities of FBR are still unknown. Thus, the goal of this study was to see how different heat treatments affected the bioactive compound content, antioxidant activity, and cosmeceutical properties of FBR, such as anti-pigmentation and anti-aging. This study involved heating FBR at three different temperatures (autoclaving: 105°C, 5–15 mins; pasteurising: 80°C, 90°C, 10 mins; and oven heating: 60°C, 80°C, 24 hrs). The antioxidant activity was measured using ferric-reducing antioxidant power (FRAP), while the anti-pigmentation and anti-aging activities were measured using tyrosinase inhibition and elastase inhibition activity, respectively. High-performance liquid chromatography (HPLC) was used to determine the composition of phenolic acids. Heat treatment at 60°C or 80°C for 24 hrs increases total phenolic content, total flavonoid content, antioxidant activity, anti-pigmentation, and anti-ageing activity in FBR, but oven heating at 80°C for 24 hrs produces the best results of all treatments. Additionally, oven heating at 80 °C for 24 hrs increases the content of gallic acid and syringic acid. However, some phenolic acids, such as p-catechuic, benzoic, and vanillic acids, were reduced at the same temperature. These findings suggested that heating conditions influence FBR's antioxidant activity, cosmeceutical properties, and bioactive compound content. FBR has the potential to be used as a promising bioingredient in the health food and cosmetic industries, given all of the enhanced effects from heat treatment.

Improvement of cosmeceutical properties in rice by-products by solid state fermentation with Aspergillus oryzae and effects of different extracting conditions

Rice milling generates a lot of rice by-products and they are commonly used as an animal feed ingredient. However, they have high cosmeceutical values, attributed to their high content of bioactive compounds. In the present study, rice by-products (broken rice and rice bran) were subjected to solid state fermentation (SSF) using Aspergillus oryzae at 30° C for 12 days and their cosmeceutical potentials were then evaluated. Different extraction conditions such as the type of solvent (water, 50% ethanol) and extraction temperature (30°C, 40°C) were also optimized using a one-factor-one-time approach. Through tyrosinase inhibition assay, it was observed that SSF has improved the anti-pigmentation effect of broken rice and rice bran 7.4-fold and 11.2-fold in comparison to their unfermented substrate, respectively. SSF has also improved the anti-ageing effect of broken rice and offered 6.6-fold of improvement in fermented rice bran. In extraction optimization studies, a stronger anti-ageing effect was observed in the water extract of both fermented substrates extracted at 40°C while the anti-pigmentation effect is stronger on 50% ethanol extract in fermented rice bran. Most phenolic acids that are commonly related to cosmeceutical purposes were detected in the extracts of both fermented substrates while most of the organic acids were detected in the water extract. Our study suggests that SSF using A. oryzae could improve the cosmeceutical activities of rice byproducts, and both water and 50% ethanol extracts have high potential to be developed as cosmeceutical bio-ingredients.

Antioxidant activities, tyrosinase inhibition activity and bioactive compounds content of broken rice fermented with Amylomyces rouxii

Solid state fermentation (SSF) utilizing filamentous fungus Amylomyces rouxii was investigated as a bio-processing strategy to enhance the bioactive properties of broken rice. Fermentation was carried out for 18 days and samples were withdrawn at 2-days interval. Established methods were deployed to assess the changes in bioactive properties and compounds content in fermented broken rice. The bioactive properties studied were total phenolic content (TPC), total flavonoid content (TFC), DPPH-radical scavenging activity and ferric-reducing antioxidant power (FRAP). Additionally, tyrosinase inhibition activity, which represents anti-pigmentation/browning property, was evaluated. Free phenolic acids and organic acids content were determined through high performance liquid chromatography (HPLC). The results showed that fermentation significantly increased the total phenolic content of broken rice from 0.03 mg GAE/g sample to 3.94 mg GAE/g sample and total flavonoid content from 0.04 to 1.71 mg QE/g sample. By the end of the fermentation, DPPH-radical scavenging of fermented broken rice was enhanced to 94.22%, compared to 9.03% in the unfermented sample. It was also observed that FRAP and tyrosinase inhibition activity of fermented broken rice were improved up to 39- fold and 50-fold, respectively. Kojic acid, a potent antioxidant and tyrosinase inhibitor, was detected in fermented broken rice, along with oxalic and ascorbic acid. Gallic, protocatechuic and 4-hydroxybenzoic acids were enhanced upon fermentation. This study manifested the positive effect of broken rice after fermentation with A. rouxii and thus revealed the potential of fermented broken rice as a promising natural bio-ingredients in food, cosmetics and medicinal products.

Facile synthesis of core-shell structured Si@graphene balls as a high-performance anode for lithium-ion batteries

Encapsulating silicon (Si) nanoparticles with graphene nanosheets in a microspherical structure is proposed to increase electrical conductivity and solve stability issues when using Si as an anode material in lithium-ion batteries (LIBs). Currently the main strategies to produce high-quality Si-graphene (Si@Gra) electrodes are (1) chemical vapor deposition (CVD) of graphene grown in situ on Si by hydrocarbon precursors and (2) encapsulating Si with a graphene oxide followed by postannealing. However, both methods require a high-temperature and are costly and time-consuming procedures, which hinders their mass scalability and practical utilization. Herein, we report a Si@Gra composite with a ball-like structure that is assembled by a facile spray drying process without a postannealing treatment. The graphene sheets are synthesized by an electrochemical exfoliation method from natural graphite. The resulting Si@Gra composite exhibits a unique core-shell structure, from which the ball-like morphology and the number of graphene layers in the Si@Gra composites are found to affect both the electric conductivity and ionic conductivity. The Si@Gra composites are found to increase the capacity of the anode and provide excellent cycling stability, which is attributed to the high electrical conductivity and mechanical flexibility of the layered graphene; additionally, a void space in the core-shelled ball structure inside the Si@Gra compensates for the Si volume expansion. As a result, the Si@few-layer graphene ball anode exhibits a high initial discharge capacity of 2882.3 mA h g-1 and a high initial coulombic efficiency of 86.9% at 0.2 A g-1. The combination of few-layer graphene sheets and the spray drying process can effectively be applied for large-scale production of core-shell structured Si@Gra composites as promising anode materials for use in high-performance LIBs.

Nanocatalyst-Assisted Fine Tailoring of Pore Structure in Holey-Graphene for Enhanced Performance in Energy Storage

Nanoporous holey-graphene (HG) shows potential versatility in several technological fields, especially in biomedical, water filtration, and energy storage applications. Particularly, for ultrahigh electrochemical energy storage applications, HG has shown promise in addressing the issue of low gravimetric and volumetric energy densities by boosting of the ion-transport efficiency in a high-mass-loaded graphene electrode. However, there are no studies showing complete control over the entire pore architecture and density of HG and their effect on high-rate energy storage. Here, we report a unique and cost-effective method for obtaining well-controlled HG, where a copper nanocatalyst assists the predefined porosity tailoring of the HG and leads to an extraordinary high pore density that exceeds 1 × 10³ μm^-2. The pore architectures of the hierarchical and homogenous pores of HG were realized through a rationally designed nanocatalyst and the annealing procedure in this method. The HG electrode with a high mass loading results in improved supercapacitor performance that is at least 1 order of magnitude higher than conventional graphene flakes (reduced electrochemically exfoliated graphene (rECG)) in areal capacitance (∼100% retention of capacitance until 15 000 cycles), energy density, and power density. The diffusion coefficient of the HG electrode is 1.5-fold higher than that of rECG at a mass loading of 15 mg cm^-2, indicating excellent ion-transport efficiency. The excellent ion-transport efficiency of HG is further proved by nearly 4-fold magnitude lowering of its R_ion (the ionic resistance in the electrolyte-filled pores) value as compared with rECG when estimated for equivalent high-mass-loaded electrodes. Furthermore, the HG exhibits a packing density that is 2 orders of magnitude higher than rECG, revealing the utility of the maximum electrode mass and possessing higher volumetric capacitance. The perfect tailoring of HG with optimized porosity allows the achievement of high areal capacitance and excellent cycling stability due to the facile ion- and charge-transport at high-mass-loaded electrodes, which could open a new avenue for addressing the long-existing issue of practical application of graphene-based energy storage devices.

Controlled multimodal hierarchically porous electrode self-assembly of electrochemically exfoliated graphene for fully solid-state flexible supercapacitor

We present here, a concentration dependent freeze-dry technique to obtain 3D graphene architectures with predetermined micron sized macropores and multimodal hierarchical nanopores for electrodes in flexible energy storage devices.

Nipah virus infection in bats (order Chiroptera) in peninsular Malaysia

Nipah virus, family Paramyxoviridae, caused disease in pigs and humans in peninsular Malaysia in 1998-99. Because Nipah virus appears closely related to Hendra virus, wildlife surveillance focused primarily on pteropid bats (suborder Megachiroptera), a natural host of Hendra virus in Australia. We collected 324 bats from 14 species on peninsular Malaysia. Neutralizing antibodies to Nipah virus were demonstrated in five species, suggesting widespread infection in bat populations in peninsular Malaysia.

Repair of glass ionomer cements--methods for conditioning the surface of the cement to achieve bonding

Two chemically different glass ionomer cements (Ketac Fil and ChemFil II Caps) and three different methods of conditioning the surface for repair were evaluated. Specimens of each material were prepared, aged and sectioned. The cut surfaces were treated with either phosphoric acid, polyacrylic acid or a combination of phosphoric acid followed by polyacrylic acid. Freshly mixed glass ionomer cement was injected against the treated surface and allowed to set under simulated intra-oral conditions. The specimens were then tested to failure in flexion after 7 days storage. The flexural strength of the repaired specimens was compared with that of control specimens of the same materials. The flexural strength of the repaired specimens was less than that of the controls. Treatment of the fractured surface with polyacrylic acid produced the weakest repair, and the use of phosphoric acid as the conditioning agent produced repaired specimens approximately 80% of the strength of the controls.

Treatment with flecainide for symptomatic and refractory tachyarrhythmias in children

Nine children, aged 2.5 months to 16 years, presenting with tachyarrhythmias were treated with intravenous (i.v.) flecainide, a type 1C antiarrhythmic drug. There were four boys and five girls; seven were supraventricular and two ventricular tachycardias and three had structural cardiac abnormalities. The i.v. dose required to terminate the arrhythmias ranged from 1.0 to 2.4 mg/kg (mean 1.55 mg/kg) although a mean of 1.94 mg/kg per dose was required to maintain sustained sinus rhythm after a single i.v. dose. Eight of the patients--six supraventricular and two ventricular tachyarrhythmias, required maintenance oral flecainide. Oral dosages of 6.7-9.5 mg/kg per day (mean of 7.97 mg/kg per day in three divided doses) were required to effectively prevent the tachyarrhythmias. Intravenous and oral flecainide are safe and effective in terminating supraventricular and ventricular tachyarrhythmias. No evidence of proarrhythmia was found in the patients during follow up of between 5 and 9 months. The present limitation of performing radiofrequency ablation on infants and small children justifies the important place of medical therapy for re-entrant supraventricular tachyarrhythmias.

SEM analyses of repaired glass-ionomer cements

This study assessed the nature of the adhesion in repaired glass-ionomer restorative materials. Two chemically different glass-ionomer cements, Ketac Fil and Chemfil II Cap, and three different methods of conditioning the surface for repair were employed. Specimens of each material were prepared and the cut surfaces were then treated with either 35% phosphoric acid, 35% polyacrylic acid or a combination of phosphoric acid followed by polyacrylic acid. Freshly mixed material was injected against these treated surfaces and allowed to set under simulated intraoral conditions. The specimens were tested to failure in flexion after seven days storage. Assessment of the fractured surfaces was then carried out using the scanning electron microscope. The results showed the occurrence of both adhesive and cohesive failure.