Dispersive XAFS Study on the Laser-Induced Reduction of a Rh3+ Ion Complex: Presence of a Rh+ Intermediate in Direct Photoreduction

The reaction mechanism of the direct photoreduction of a Rh3+ ion complex to a Rh0 species induced by pulsed ultraviolet laser irradiation was studied using dispersive X-ray absorption fine structure (DXAFS) spectroscopy. The time-resolved X-ray absorption near edge structure (XANES) showed the absence of isosbestic points and suggested that more than two Rhn+ species contribute toward the direct photoreduction of Rh3+. Analysis of the time-resolved XANES data by singular value deposition showed that the direct photoreduction involves three Rhn+ species. Multivariate curve resolution by alternating least-squares analysis (MCR-ALS) of the time-resolved XANES data gave pure spectra and concentration profiles of the three Rhn+ species. The Rhn+ species were assigned to Rh3+, Rh+, and Rh0 species based on the features of the pure XANES spectra. The concentration profiles suggested that the direct photoreduction proceeds in the order of Rh3+ → Rh+ → Rh0. A reaction mechanism, which was proposed involving photoreductions of Rh3+ and Rh+, photoinduced autocatalytic reductions of Rh3+ and Rh+, and photooxidation of Rh+, well reproduced the concentration profiles of three Rhn+ species

In Situ Time-Resolved XAFS Study on Laser-Induced Particle Formation of Pd(II) Ion in a Solution

Previously, we showed that the irradiation of a nanosecond pulsed UV laser with high pulse energy into the Pd(II) solution forms the Pd particle with submicron size (100–500 nm), which has not been generated in the photo-induced particle formation using a UV lamp. It indicates that the laser irradiation with high pulse energy promotes the Pd particle growth, the mechanism of which is unclear. In this work, we studied the particle formation in the Pd(II) solution in the laser irradiation with high pulse energy using time-resolved X-ray absorption fine structure (XAFS) spectroscopy.6th International Conference on Advanced Nanoparticle Generation & Excitation by Lasers in Liquid

Mice with an Oncogenic HRAS Mutation are Resistant to High-Fat Diet-Induced Obesity and Exhibit Impaired Hepatic Energy Homeostasis

Costello syndrome is a “RASopathy” that is characterized by growth retardation, dysmorphic facial appearance, hypertrophic cardiomyopathy and tumor predisposition. >80% of patients with Costello syndrome harbor a heterozygous germline G12S mutation in HRAS. Altered metabolic regulation has been suspected because patients with Costello syndrome exhibit hypoketotic hypoglycemia and increased resting energy expenditure, and their growth is severely retarded. To examine the mechanisms of energy reprogramming by HRAS activation in vivo, we generated knock-in mice expressing a heterozygous Hras G12S mutation (HrasG12S/+ mice) as a mouse model of Costello syndrome. On a high-fat diet, HrasG12S/+ mice developed a lean phenotype with microvesicular hepatic steatosis, resulting in early death compared with wild-type mice. Under starvation conditions, hypoketosis and elevated blood levels of long-chain fatty acylcarnitines were observed, suggesting impaired mitochondrial fatty acid oxidation. Our findings suggest that the oncogenic Hras mutation modulates energy homeostasis in vivo

Possible mitochondrial dysfunction in a patient with deafness, dystonia, and cerebral hypomyelination (DDCH) due to BCAP31 Mutation

Abstract Background Deafness, dystonia, and cerebral hypomyelination (DDCH) is an X‐linked disorder due to hemizygous mutations of BCAP31. Methods We report an 8‐year‐old boy with DDCH who possibly accompanied mitochondrial dysfunction. Clinical evaluation, respiratory chain enzyme assay, and whole exome sequencing analysis were performed. Results Mitochondrial dysfunction was suspected by respiratory chain enzyme assay on his cultured skin fibroblasts which showed significantly decreased complex I enzyme activity. Whole exome sequencing analysis revealed a recurrent BCAP31 mutation (c.97C>T:p.Gln33*) which confirmed the diagnosis of DDCH for the patient. Conclusion We speculate that mitochondrial dysfunction may be a feature in patients with DDCH

EATV and AF Prevalence

Background: Although increasing evidence suggests that epicardial adipose tissue volume (EATV) is associated with atrial fibrillation (AF), it is controversial whether there is a dose-response relationship of increasing EATV along the continuum of AF. We evaluated the effect of the EATV on the prevalence of paroxysmal AF (PAF) and persistent AF (PeAF) and the relationships with cardiac structure and functional remodeling. Methods and Results: Subjects who underwent multidetector computed tomography (MDCT) coronary angiography because of symptoms suggestive of coronary artery disease were divided into sinus rhythm (SR) (n=112), PAF (n=133), and PeAF (n=71) groups. The EATV index (EATV/body surface area, mL/m2) was strongly associated with the prevalence of PAF and PeAF on the model adjusted for known AF risk factors. The effect of the EATV index on the prevalence of PeAF, but not on that of PAF, was modified by the left atrial (LA) dimension, suggesting that extension of the LA dimension is related to EATV expansion in PeAF. The cutoff value of the EATV index for the prevalence was higher in PeAF than in PAF (64 vs. 55 mL/m2, P<0.01). Conclusions: The EATV index is associated with the prevalence of PAF and PeAF, and its cutoff values are predictive for PAF and PeAF development independently of other AF risk factors