Nonpolar selective emission (NPSE) of carbonyl-bridged rhodols.

Polarity-responsive luminophores (PRLs), whose emission properties change in response to the polarity of the surrounding environment, are used for the fluorescence sensing of intracellular environments and various chemical compounds. Herein, we propose a concept called nonpolar selective emission (NPSE) for the development of a new PRL family. Unlike the conventional emission of PRLs, the NPSE luminophore can switch to a completely non-emissive state upon a slight increase in solvent polarity. The NPSE concept offers a new means of distinguishing between nonpolar and low-polarity environments. Moreover, the NPSE property is little affected by the viscosity of the surrounding medium. We demonstrate that NPSE dyes can be used as emission sensors for molecular gases. Furthermore, we discovered the potential use of NPSE dyes as a time-dependent security ink triggered by the volatilization of polar molecules.

Coerulein B: a water-soluble and water-compatible near-infrared photoredox catalyst.

The recent expansion of photoredox catalysis into chemical biology has underscored the importance of photochemistry, attracting the attention of many researchers. On the other hand, as conventional photoredox catalysts were developed for organic synthesis, there is a necessity to develop biocompatible photoredox catalysts. Here, we show a water-soluble and water-compatible near-infrared (NIR) photoredox catalyst, coerulein B (CB). CB is a water-soluble molecule with a slightly twisted molecular structure, and its anionic species (CB-) exhibits NIR absorption and emission. We demonstrated that CB works as a water-compatible photoredox catalyst in the coupling reaction of pyridine hydrochloride and aryldiazonium salt. These results indicate that CB is one of the promising candidates for photocatalysts used in biological reactions.

Evaluation of Cell Responses of Saccharomyces cerevisiae under Cultivation Using Wheat Bran as a Nutrient Resource by Analyses of Growth Activities and Comprehensive Gene Transcription Levels.

Wheat bran has high nutritional values and is also cheaper than yeast nitrogen base as an important component of a medium. Although its use in microbial cultivations is expected, research and development has hardly progressed so far. In this study, with experimental Saccharomyces cerevisiae BY4741, the cell responses to wheat bran as a nutrient were evaluated by analyses of cell growth, ethanol production, and comprehensive gene transcription levels. Comparing wheat bran and yeast nitrogen base, BY4741 showed specific growth rates of 0.277 ± 0.002 and 0.407 ± 0.035 as a significant difference. Additionally, wheat bran could be used as a restricted media component like yeast nitrogen base. However, in 24 h of cultivation with wheat bran and yeast nitrogen base, although conversion ratios of ethanol productions showed no significant difference at 63.0 ± 7.2% and 62.5 ± 8.2%, the ratio of cell production displayed a significant difference at 7.31 ± 0.04% and 4.90 ± 0.16%, indicating a different cell response. In fact, the comprehensive evaluation of transcription levels strongly suggested major changes in glucose metabolism. This study indicated that BY4741 could switch transcription levels efficiently to use wheat bran.

Polymorphisms of the Dopamine D4 Receptor Gene in Stabled Horses are Related to Differences in Behavioral Response to Frustration.

In stabled horses, behavioral responses to frustration are often observed, especially around feeding time. These behavioral responses are a useful indicator of their welfare. In this study, we investigated the association between this behavioral indicator and DRD4 gene polymorphisms in stabled horses. Twenty one horses housed in two stables were used. The horses were observed for approximately 4 h around feeding over three or more days using focal-sampling and instantaneous-sampling. Horses were genotyped for the A-G substitution in the DRD4 gene. The effects of the A-G substitution (with or without the A allele in the DRD4 gene), the stables, and their interaction on the frequency of behavioral responses to frustration were analyzed using general linear models. The total time budget of behavioral responses to frustration was higher in horses without the A allele than in those with the A allele (P = 0.007). These results indicate that the A-G substitution of the DRD4 gene is related to frustration-related behavioral responses in stabled horses. Appropriate consideration should be made for the DRD4 gene polymorphism when the welfare of stabled horses is assessed, based on this behavioral indicator.