The unfolding process and self-assembly of a foldable oligomer (foldamer 1) at the liquid/graphite interface were investigated by scanning tunnelling microscopy. At the level of molecular conformation, we identified several molecular conformations (A(z), B, C, D, E) that represent intermediate states during unfolding, which may help to elucidate the unfolding process at the liquid/graphite interface. Adsorption at the interface traps the intermediate states of the unfolding process, and STM has proved to be a powerful technique for investigating folding and unfolding of a foldamer at the molecular level, which are not accessible by other methods. The STM observations also revealed that varying the solvent and/or concentration results in different self-assemblies of foldamer 1 as a result of variations in molecular conformations. The solvent and concentration effects were attributed to the changes in existing states (extended or folded) of foldamers in solution, which in turn affect the distribution of adsorbed molecular conformations at the interface. This mechanism is quite different from other systems in which solvent and concentration effects were also observed.
Fang L, Chen Y, Huang J, Liu L, Quan J, Li C-C, Yang Z. Formal synthesis of cortistatins. Journal of Organic Chemistry [Internet]. 2011;(8):2479-2487. 访问链接
Based on the prevalent son preference in China, this paper proposes a new measure of relative bargaining power within the household. Using data from China Health and Nutrition Survey, we show that a woman with a first-born son has a 3.9 percentage points' greater role in household decision-making than a woman with a first-born daughter Having a first-horn son improves the mother's nutrition intakes and reduces her likelihood of being underweight. While thinking of these impacts as being channeled through intrahousehold bargaining power we cannot fully rule out other possible direct effects of a first-born son on the outcomes.