Reduction of water content in calcium aluminate cement with/out phosphate modification for alternative cementation technique

Cementation of the secondary aqueous wastes from TEPCO Fukushima Daiichi Nuclear Power Plant is challenging due to the significant strontium content and radioactivity, leading to a potential risk of hydrogen gas generation via radiolysis of water content. The present study investigates the reduction of water content in calcium aluminate cement (CAC) with/out phosphate modification by a heat-treatment during the solidification. The reduction of water in the CAC was found restricted by the rapid formation of crystalline hydration phases, whereas the phosphate-modified system allowed the gradual reduction of water, achieving the reduction of 60% water content at 95 °C. Curing at 60–95 °C also eliminated the significant cracks found at 35 °C in the phosphate system. The possible difference in the amorphous products, NaCaPO4∙nH2O type at 35 °C and Ca(HPO4)∙xH2O type at 60–95 °C, may have contributed to the improvement in the microstructure together with the change in the pore size distribution

ANALYTICAL STUDY ON TPD MEASUREMENTS DURING NEA ACTIVATION PROCESS

We have investigated the desorption of absorbed Cs-related species on the sample surface by temperature programed desorption (TPD). After forming the negative electron affinity (NEA) surface by alternating supply of Cs and O_2 onto the clean p-GaAs (100) surface in an ultra-high vacuum condition. It was found that Cs had several forms of adsorption states on the NEA surface from TPD measurements. The quantum efficiency under 826 nm illumination drops to zero over 300°C, while that with 367 nm drops to zero at about 500°C. It is considered that Cs desorbed about 100 to 300°C was deeply involved in the formation of the NEA surface

Influence of residual Ga_2O_3 and Cs on the increase in the maximum quantum efficiency of NEA-GaAs by a two-step thermal cleaning process

We investigated the relationship between the increase in the maximum quantum efficiency of negative electron affinity (NEA)-GaAs depending on the thermal cleaning conditions and residual species, e.g., Ga_2O_3 and Cs atoms, on the GaAs surface using temperature-programmed desorption. We found that the increase in the maximum quantum efficiency occurs during thermal cleaning at 500–600℃ for ～8.5 min. The increase in ratio was maximum when the amount of Ga_2O_3 on the GaAs surface was maximum. In the case that Cs atoms remained, when the thermal cleaning was performed in a temperature range where Ga_2O_3 was not formed, the effect facilitating an NEA surface formation was observed. However, the residual Cs atoms might not be affected at an increased maximum quantum efficiency. From the above results, we considered that the double-dipole structures of Cs-Ga_2O_3 and Cs-O are significant to the high quantum efficiency. The Cs-O dipoles are considered to form easily when Ga_2O_3 is on the GaAs surface before the NEA activation, and the amount of Cs-O dipoles required to reduce the vacuum level below the conduction band minimum increase more than usually NEA surface. As a result, the maximum quantum efficiency increases

Design and development of the ATLAS central solenoid magnet

The ATLAS central solenoid magnet is being constructed to provide a magnetic field of 2 T in the central tracking part of the ATLAS detector. As a key technology for a solenoid coil as thin as possible, a high-strength aluminum stabilized superconductor has been developed, achieving a yield strength of >100 MPa at 4.2 K. This paper describes the status of the design and development of the solenoid magnet. (14 refs)

Profiling allele-specific gene expression in brains from individuals with autism spectrum disorder reveals preferential minor allele usage.

One fundamental but understudied mechanism of gene regulation in disease is allele-specific expression (ASE), the preferential expression of one allele. We leveraged RNA-sequencing data from human brain to assess ASE in autism spectrum disorder (ASD). When ASE is observed in ASD, the allele with lower population frequency (minor allele) is preferentially more highly expressed than the major allele, opposite to the canonical pattern. Importantly, genes showing ASE in ASD are enriched in those downregulated in ASD postmortem brains and in genes harboring de novo mutations in ASD. Two regions, 14q32 and 15q11, containing all known orphan C/D box small nucleolar RNAs (snoRNAs), are particularly enriched in shifts to higher minor allele expression. We demonstrate that this allele shifting enhances snoRNA-targeted splicing changes in ASD-related target genes in idiopathic ASD and 15q11-q13 duplication syndrome. Together, these results implicate allelic imbalance and dysregulation of orphan C/D box snoRNAs in ASD pathogenesis

Common Variants in the COL4A4 Gene Confer Susceptibility to Lattice Degeneration of the Retina

Lattice degeneration of the retina is a vitreoretinal disorder characterized by a visible fundus lesion predisposing the patient to retinal tears and detachment. The etiology of this degeneration is still uncertain, but it is likely that both genetic and environmental factors play important roles in its development. To identify genetic susceptibility regions for lattice degeneration of the retina, we performed a genome-wide association study (GWAS) using a dense panel of 23,465 microsatellite markers covering the entire human genome. This GWAS in a Japanese cohort (294 patients with lattice degeneration and 294 controls) led to the identification of one microsatellite locus, D2S0276i, in the collagen type IV alpha 4 (COL4A4) gene on chromosome 2q36.3. To validate the significance of this observation, we evaluated the D2S0276i region in the GWAS cohort and in an independent Japanese cohort (280 patients and 314 controls) using D2S0276i and 47 single nucleotide polymorphisms covering the region. The strong associations were observed in D2S0276i and rs7558081 in the COL4A4 gene (Pc = 5.8×10−6, OR = 0.63 and Pc = 1.0×10−5, OR = 0.69 in a total of 574 patients and 608 controls, respectively). Our findings suggest that variants in the COL4A4 gene may contribute to the development of lattice degeneration of the retina

Characterization of an Orphan Diterpenoid Biosynthetic Operon from Salinispora arenicola

While more commonly associated with plants than microbes, diterpenoid natural products have been reported to have profound effects in marine microbe–microbe interactions. Intriguingly, the genome of the marine bacterium Salinispora arenicola CNS-205 contains a putative diterpenoid biosynthetic operon, terp1. Here recombinant expression studies are reported, indicating that this three-gene operon leads to the production of isopimara-8,15-dien-19-ol (4). Although 4 is not observed in pure cultures of S. arenicola, it is plausible that the terp1 operon is only expressed under certain physiologically relevant conditions such as in the presence of other marine organisms