Order-disorder transition in the S = ½ kagome antiferromagnets claringbullite and barlowite.

The transition in the quantum magnets barlowite, Cu4(OH)6FBr, and claringbullite, Cu4(OH)6FCl is of an order-disorder type, where at ambient temperature interlayer Cu2+ ions are dynamically disordered over three equivalent positions. The disorder becomes static as the temperature is decreased, resulting in a lowering of symmetry. Ab initio density functional theory calculations explain this structural phase transition and provide insights regarding the differences between these two materials.

Two-Enzyme Pathway Links l-Arginine to Nitric Oxide in N-Nitroso Biosynthesis.

Nitric oxide (NO) has wide-ranging roles in biology, but less is known about its role in building chemical diversity. Here we report a new route to NO from the biosynthetic pathway to the N-nitroso compound streptozocin. We show that the N-nitroso group of streptozocin comes from the biosynthetic reassembly of l-arginine, with the guanidino nitrogens forming a nitrogen-nitrogen bond.

Nutrient supplements boost yeast transformation efficiency.

Efficiency of yeast transformation is determined by the rate of yeast endocytosis. The aim of this study was to investigate the effect of introducing amino acids and other nutrients (inositol, adenine, or p-aminobenzoic acid) in the transformation medium to develop a highly efficient yeast transformation protocol. The target of rapamycin complex 1 (TORC1) kinase signalling complex influences the rate of yeast endocytosis.