Bis(naphthol)-based fluorescent chemoprobe for cesium cation and its immobilisation on silica nanoparticle as a high selective adsorbent

<p>A bis(naphthol)-based cation receptor <b>1</b> has been synthesised by three steps of synthetic procedure. The spectroscopic properties of <b>1</b> upon addition of various metal ions were investigated by UV–vis absorption and fluorescence spectroscopy. As a result, the absorption of <b>1</b> was linearly decreased as a function of concentration of added Cs⁺. Also, <b>1</b> exhibited dramatic fluorescence quenching effect upon exposure to caesium cation. Contrastively, no significant quenching effect was observed upon addition of other metal ions such as Na⁺, K⁺, Rb⁺, Mg²⁺, Ca²⁺, Sr²⁺, Ba²⁺, Ni²⁺ and Zn²⁺. It was found that <b>1</b> formed a 1:1 complex with Cs⁺ by Job’s plot. Furthermore, we also prepared <b>1</b>-functionalised silica nanoparticle (<b>SiO</b>_<b>2</b><b>-1</b>) as an adsorbent for Cs⁺. <b>SiO</b>_<b>2</b><b>-1</b> showed a great capacity for selective removal of caesium ion from aqueous solution as well as from tap water. Thus, it is potentially useful for the detection and removal of caesium cation from environmental and biological fluids polluted by nuclear radiation and nuclear waste.</p

Calix[4]arene-based fluorescent probe and the adsorption capacity of its electrospun nanofibrous film for the cesium cation as an adsorbent

<p>Calix[4]arene-based cation receptor 1 has been synthesised by following a multi-step synthetic procedure. The fluorescence properties of 1 upon the addition of various metal ions were investigated by fluorescence spectroscopy. As a result, it was revealed that 1 displayed dramatic quenching effect upon the exposure to Cs⁺. In contrast, no significant quenching effects were observed upon the addition of other metal ions such as Li⁺, Na⁺, K⁺, Mg²⁺, Ca²⁺, Sr²⁺, Ag⁺, Zn²⁺ and Ni²⁺. Compound 1 was also found by Job plot to form a 1:1 complex with Cs⁺. In addition, we also prepared 1-embedded electrospun nanofibrous film (NF-1) as an adsorbent for Cs⁺. NF-1 is proved to adsorb Cs⁺ effectively from an aqueous solution, indicating that it would be usefully utilised as an adsorbent to remove Cs⁺.</p

p62/SQSTM1 is required for the protection against endoplasmic reticulum stress-induced apoptotic cell death

<p>Endoplasmic reticulum (ER) stress is triggered by various cellular stresses that disturb protein folding or calcium homeostasis in the ER. To cope with these stresses, ER stress activates the unfolded protein response (UPR) pathway, but unresolved ER stress induces reactive oxygen species (ROS) accumulation leading to apoptotic cell death. However, the mechanisms that underlie protection from ER stress-induced cell death are not clearly defined. The nuclear factor erythroid 2-related factor 2 (Nrf2)-Kelch-like ECH-associated protein 1 (Keap1) pathway plays a crucial role in the protection of cells against ROS-mediated oxidative damage. Keap1 acts as a negative regulator of Nrf2 activation. In this study, we investigated the role of the Nrf2-Keap1 pathway in protection from ER stress-induced cell death using tunicamycin (TM) as an ER stress inducer. We found that Nrf2 is an essential protein for the prevention from TM-induced apoptotic cell death and its activation is driven by autophagic Keap1 degradation. Furthermore, ablation of p62, an adapter protein in the autophagy process, attenuates the Keap1 degradation and Nrf2 activation that was induced by TM treatment, and thereby increases susceptibility to apoptotic cell death. Conversely, reinforcement of p62 alleviated TM-induced cell death in p62-deficient cells. Taken together, these results demonstrate that p62 plays an important role in protecting cells from TM-induced cell death through Nrf2 activation.</p

sj-docx-1-tar-10.1177_17534666231162244 – Supplemental material for A prospective study on the long-term storage of sputum and the recovery of nontuberculous mycobacteria

Supplemental material, sj-docx-1-tar-10.1177_17534666231162244 for A prospective study on the long-term storage of sputum and the recovery of nontuberculous mycobacteria by Byoung Soo Kwon, Jeong Su Park, Jung-A Shin, Eun Sun Kim, Sung Yoon Lim, Myung Jin Song, Yeon-Wook Kim, Hyung-Jun Kim, Yeon Joo Lee, Jong Sun Park, Young-Jae Cho, Ho Yoon, Choon-Taek Lee and Jae Ho Lee in Therapeutic Advances in Respiratory Disease</p