Selective labeling of proteins on living cell membranes using fluorescent nanodiamond probes

The impeccable photostability of fluorescent nanodiamonds (FNDs) is an ideal property for use in fluorescence imaging of proteins in living cells. However, such an application requires highly specific labeling of the target proteins with FNDs. Furthermore, the surface of unmodified FNDs tends to adsorb biomolecules nonspecifically, which hinders the reliable targeting of proteins with FNDs. Here, we combined hyperbranched polyglycerol modification of FNDs with the -lactamase-tag system to develop a strategy for selective imaging of the protein of interest in cells. The combination of these techniques enabled site-specific labeling of Interleukin-18 receptor alpha chain, a membrane receptor, with FNDs, which eventually enabled tracking of the diffusion trajectory of FND-labeled proteins on the membrane surface

Thermally stable graft-type polymer electrolyte membranes consisting based on poly (ether ether ketone) and crosslinked graft-polymers for fuel cell applications

The effect of crosslinking on the thermal stability of poly (styrenesulfonic acid)-grafted poly (ether ether ketone) polymer electrolyte membranes (PEEK-PEMs) was investigated in water at 120 °C. The radiation-induced graft polymerization of an ethyl 4-styrenesulfonate (ETSS) monomer onto PEEK substrates, with divinylbenzene (DVB) (0.05, 0.1, 0.2, and 0.5wt.%) as a crosslinker, followed by hydrolysis, generated crosslinker-containing PEEK-PEMs (PEEK-×0.05, -×0.1, -×0.2, and -×0.5), because the crosslinker (up to 0.5wt.%) did not cause any destructive effect on the on grafting and hydrolysis rates. As a result, grafting degrees of 100–114% and ion exchange capacities (IECs) of 2.2–2.7 mmol/g, respectively, were achieved. Increasing the DVB amounts (from 0 to 0.5 wt.%), the conductivity, and water uptakes decreased; the PEEK-×0.5 showed a conductivity of 0.10 S/cm and water uptake of 43%. This confirms the successful incorporation of crosslinking structures on the graft-polymers. The hydrothermal test involved the immersion of PEMs in water at 120 °C for 500 hours. The no-crosslinked PEEK-PEMs with the same IEC (2.7 mmol/g) experienced a decreases in the weight and IEC to 84 and 68% levels from the initial values, respectively, while those of crosslinked PEEK-×0.05 almost maintained their initial values (100 and 96%, respectively). These results indicated that very small amounts of crosslinkers can decreases the conductivity and the water absorption tendency while increasing the hydrothermal stability at higher temperatures

Occurrence of bla(NDM-1) in a clinical isolate of Acinetobacter lwoffii in Japan: comparison of bla(NDM-1)-harboring plasmids between A. lwoffii and A. pittii originated from the hospital sink

ArticleJapanese Journal of Infectious Diseases 74(3) : 252-254(2021)journal articl