C9orf72-derived arginine-rich poly-dipeptides impede phase modifiers

Nuclear import receptors (NIRs) not only transport RNA-binding proteins (RBPs) but also modify phase transitions of RBPs by recognizing nuclear localization signals (NLSs). Toxic arginine-rich poly-dipeptides from C9orf72 interact with NIRs and cause nucleocytoplasmic transport deficit. However, the molecular basis for the toxicity of arginine-rich poly-dipeptides toward NIRs function as phase modifiers of RBPs remains unidentified. Here we show that arginine-rich poly-dipeptides impede the ability of NIRs to modify phase transitions of RBPs. Isothermal titration calorimetry and size-exclusion chromatography revealed that proline:arginine (PR) poly-dipeptides tightly bind karyopherin-β2 (Kapβ2) at 1:1 ratio. The nuclear magnetic resonances of Kapβ2 perturbed by PR poly-dipeptides partially overlapped with those perturbed by the designed NLS peptide, suggesting that PR poly-dipeptides target the NLS binding site of Kapβ2. The findings offer mechanistic insights into how phase transitions of RBPs are disabled in C9orf72-related neurodegeneration

Numerical Analysis on Gas Separator with Thermal Transpiration in Micro Channels

"28th International Symposium on Rarefied Gas Dynamics 2012"; Conference date: 9–13 July 2012; Location: Zaragoza, SpainA gas separator that can induce a large variation of mole fraction by a small temperature difference in a single membrane is proposed. The separator makes use of two effects: The first effect is the thermal transpiration through microchannels in the membrane; the second is the accumulation of the effect of micro-channels in the counter flow of gas mixture that flows around the membrane. The numerical results show that small gas separation effects of numerous micro-channels are accumulated to induce a large variation of the mole fraction along the membrane. The numerical calculation is carried out by the direct simulation Monte Carlo (DSMC) method and a fluid model based on the mass conservation which is shown to be able to simulate the DSMC result. The performance of the device is investigated for several temperature differences between the two sides of the membrane. The relation to the membrane gas separation by Knudsen diffusion is also discussed

Efficient Hydrogen Production by Direct Electrolysis of Waste Biomass at Intermediate Temperatures

Biomass has been considered as an alternative feedstock for energy and material supply. However, the lack of high-efficiency and low-cost processes for biomass utilization and conversion hinders its large-scale application. This report describes electrochemical hydrogen production from waste biomass that does not require large amounts of energy or high production costs. Hydrogen was produced by the electrolysis of bread residue, cypress sawdust, and rice chaff at an onset cell voltage of ca. 0.3 V, with high current efficiencies of approximately 100% for hydrogen production at the cathode and approximately 90% for carbon dioxide production at the anode. The hydrogen yields per 1 mg of the raw material were 0.1–0.2 mg for all tested fuels. Electrolysis proceeded continuously at plateau voltages that were proportional to the current. These characteristics were attributable to the high catalytic activity of the carbonyl-group functionalized mesoporous carbon for the anode reaction, and that the major components of biomass such as cellulose, starch, lignin, protein, and lipid were effectively utilized as fuels for hydrogen production