Highly Chemoselective Self-Calibrated Fluorescent Probe Monitors Glutathione Dynamics in Nucleolus in Live Cells.

The redox-regulator glutathione (GSH) maintains a specific redox potential to sustain routine cellular activity from oxidative damage. In the early stage of the cell cycle process, the glutathione levels increase in the nuclei for protecting the DNA replication process from reactive oxygen species (ROS). In the first attempt, we developed a new ratiometric fluorescent probe that has provided information about glutathione levels in the nuclei. The UV-vis. absorption of probe GScp has shown a hypsochromic shift from 410 to 350 nm in the presence of GSH. In fluorescence titration, we observed that fluorescence emission of the GScp switched from 510 to 460 nm in the presence of GSH. The self-calibrated probe GScp has shown nearly optimal reversibility in GSH redox dynamics with the dissociation constant 2.47 mM. The probe is ideal for GSH tracking in live cells, as its toxicity has within the safe zone. The probe GScp has validated GSH levels in nucleoli by providing fluorescence images in blue-channel. This finding inspires us to use for validation of GSH dynamics in the nucleoli in the cell cycle process.

[Research on controlling iron release of desalted water transmitted in existing water distribution system].

Desalted water, with strong corrosion characteristics, would possibly lead to serious "red water" when transmitted and distributed in existing municipal water distribution network. The main reason for red water phenomenon is iron release in water pipes. In order to study the methods of controlling iron release in existing drinking water distribution pipe, tubercle analysis of steel pipe and cast iron pipe, which have served the distribution system for 30-40 years, was carried out, the main construction materials were Fe3O4 and FeOOH; and immersion experiments were carried in more corrosive pipes. Through changing mixing volume of tap water and desalted water, pH, alkalinity, chloride and sulfate, the influence of different water quality indexes on iron release were mainly analyzed. Meanwhile, based on controlling iron content, water quality conditions were established to meet with the safety distribution of desalted water: volume ratio of potable water and desalted water should be higher than or equal to 2, pH was higher than 7.6, alkalinity was higher than 200 mg x L(-1).