King Saud University

About: King Saud University is a education organization based out in Riyadh, Saudi Arabia. It is known for research contribution in the topics: Population & Adsorption. The organization has 22106 authors who have published 57908 publications receiving 1042234 citations. The organization is also known as: Riyadh University.

Thymoquinone protects against carbon tetrachloride hepatotoxicity in mice via an antioxidant mechanism.

Abstract: Thymoquinone (TQ) is the major active component of the volatile oil of Nigella sativa seeds The effects of TQ on carbon tetrachloride (CCl4)-induced hepatotoxicity was investigated in male Swiss albino mice Carbon tetrachloride (20 microliters/Kg, ip) injected into mice, induced damage to liver cells and was followed by the increase in serum alanine aminotransferase (ALT) activity after 24 h Oral administration of TQ in a single dose (100 mg/Kg) resulted in significant (p < 0001) protection against the hepatotoxic effects of CCl4 TQ was tested as a substrate for mice hepatic DT-diaphorase in the presence of NADH TQ appears to undergo reduction to dihydrothymoquinone (DHTQ) Reduction rates as a function of protein (liver homogenate) and substrate (TQ) concentrations are reported An apparent K(m) of 01 mM and an apparent Vmax of 74 mumol/min/g liver were measured TQ and DHTQ inhibited the in vitro non-enzymatic lipid peroxidation in liver homogenate (induced by Fe(3+)-ascorbate) in a dose dependent manner In this in vitro model DHTQ was more potent in comparison with TQ and butylated hydroxytoluene (BHT) The IC50 for DHTQ, TQ and BHT were found to be 034, 087 and 058 microM respectively The data suggest that the in vivo protective action of TQ against CCl4-induced hepatotoxicity may be mediated through the combined antioxidant properties of TQ and its metabolite DHTQ

In situ plasmonic Ag nanoparticle anchored TiO2 nanotube arrays as visible-light-driven photocatalysts for enhanced water splitting

Abstract: An ultrasonication-assisted in situ deposition strategy was utilised to uniformly decorate plasmonic Ag nanoparticles on vertically aligned TiO2 nanotube arrays (NTAs) to construct a Ag@TiO2 NTA composite. The Ag nanoparticles act as efficient surface plasmon resonance (SPR) photosensitizers to drive photocatalytic water splitting under visible light irradiation. The Ag nanoparticles were uniformly deposited on the surface and inside the highly oriented TiO2 nanotubes. The visible-light-driven hydrogen production activities of silver nanoparticle anchored TiO2 nanotube array photocatalysts were evaluated using methanol as a sacrificial reagent in water under a 500 W Xe lamp with a UV light cutoff filter (λ ≥ 420 nm). It was found that the hydrogen production rate of the Ag@TiO2 NTAs prepared with ultrasonication-assisted deposition for 5 min was approximately 15 times higher than that of its pristine TiO2 NTAs counterpart. The highly efficient photocatalytic hydrogen evolution is attributed to the SPR effect of Ag for enhanced visible light absorption and boosting the photogenerated electron–hole separation/transfer. This strategy is promising for the design and construction of high efficiency TiO2 based photocatalysts for solar energy conversion.

Golden single-atomic-site platinum electrocatalysts

Abstract: Bimetallic nanoparticles with tailored structures constitute a desirable model system for catalysts, as crucial factors such as geometric and electronic effects can be readily controlled by tailoring the structure and alloy bonding of the catalytic site. Here we report a facile colloidal method to prepare a series of platinum–gold (PtAu) nanoparticles with tailored surface structures and particle diameters on the order of 7 nm. Samples with low Pt content, particularly Pt4Au96, exhibited unprecedented electrocatalytic activity for the oxidation of formic acid. A high forward current density of 3.77 A mgPt−1 was observed for Pt4Au96, a value two orders of magnitude greater than those observed for core–shell structured Pt78Au22 and a commercial Pt nanocatalyst. Extensive structural characterization and theoretical density functional theory simulations of the best-performing catalysts revealed densely packed single-atom Pt surface sites surrounded by Au atoms, which suggests that their superior catalytic activity and selectivity could be attributed to the unique structural and alloy-bonding properties of these single-atomic-site catalysts. Bimetallic nanoparticles with tailored structure constitute a desirable model system for catalysts. PtAu nanoparticles with Pt single-atom surface sites, prepared by a colloidal method, exhibit unprecedented electrocatalytic activity for formic acid oxidation.

Autozygome-guided exome sequencing in retinal dystrophy patients reveals pathogenetic mutations and novel candidate disease genes

Abstract: Retinal dystrophy (RD) is a heterogeneous group of hereditary diseases caused by loss of photoreceptor function and contributes significantly to the etiology of blindness globally but especially in the industrialized world. The extreme locus and allelic heterogeneity of these disorders poses a major diagnostic challenge and often impedes the ability to provide a molecular diagnosis that can inform counseling and gene-specific treatment strategies. In a large cohort of nearly 150 RD families, we used genomic approaches in the form of autozygome-guided mutation analysis and exome sequencing to identify the likely causative genetic lesion in the majority of cases. Additionally, our study revealed six novel candidate disease genes (C21orf2, EMC1, KIAA1549, GPR125, ACBD5, and DTHD1), two of which (ACBD5 and DTHD1) were observed in the context of syndromic forms of RD that are described for the first time.