In recent years, there has been great interest in mental health disorders. It is very important for people with mental health disorders to protect themselves from the stressful conditions that can occur as part of daily life before their symptoms become worse. We attempted to identify stress markers in skin gases in order to study the stress condition non-invasively in real time. We investigated changes in the skin gas components relative to the normal skin gas components of the subjects when stress was induced in the subjects using the Trier social stress test method, and we attempted to identify stress markers from those changes. We used a statistical analysis method and identified six stress markers in skin gases released from the armpits of the subjects.

Simultaneous electrorotation enables the determination of the electrical properties of cells (membrane capacitance and cytoplasm conductivity) after a single operation of the device.

Green leaf volatiles are emitted by green plants and induce defence responses. Those with antifungal activities in plants may replace chemicals as natural post-harvest treatments. We investigated the postharvest treatment of strawberry with trans -2-hexenal and cis -3-hexenal and observed a decrease in the mould infection rate. To determine the volatiles’ functions, we conducted a component analysis of the volatiles released from trans -2-hexenal-treated strawberry and analysed gene expression. Several acetates, which were expected to be metabolites of trans -2-hexenal in fruit, were released from treated strawberry; however, these acetates did not inhibit fungal growth. The gene expression analysis suggested that postharvest strawberries were not protected by jasmonic acid-mediated signalling but by another stress-related protein. Harvested strawberries experience stress induced by harvest-related injuries and are unable to perform photosynthesis, which might result in different responses than in normal plants.

Electron capture dissociation (ECD) and electron transfer dissociation (ETD) of gas-phase ions are widely used for peptide/protein sequencing by mass spectrometry. To understand the general mechanism of ECD/ETD of peptides, we focused on the ETD fragmentation of metal-peptide complexes in the absence of remote protons. Since Zn(2+) strongly binds to neutral histidine residues in peptides, Zn(2+)-polyhistidine complexation does not generate any remote protons. However, in the absence of remote protons, electron transfer to the Zn(2+)-polyhistidine complex induced the N-Cα bond cleavage. The formation pathway for the ETD products was investigated by density functional theory calculations. The calculations showed that the charge-reduced zinc-peptide radical, [M + Zn](•+), can exist in the low-energy zwitterionic amide π* states, which underwent homolytic N-Cα bond dissociation. The homolytic cleavage resulted in the donation of an electron from the N-Cα bond to the nitrogen atom, producing an iminoenol c' anion. The counterpart z(•) radical contained a radical site on the α-carbon atom. The iminoenol c' anion then abstracted a proton to presumably form the more stable amide c' fragment. The current experimental and computational joint study strongly suggested that the N-Cα bond cleavage occurred through the aminoketyl radical-anion formation for Zn(2+)-polyhistidine complexes in ETD.