Sex and Diet-Related Disparities in Low Handgrip Strength among Young and Middle-Aged Koreans: Findings Based on the Korea National Health and Nutrition Examination Survey (KNHANES) from 2014 to 2017

“Possible sarcopenia” may be defined as a low muscle strength assessed by handgrip strength (HGS) by sex. We examined the sex-specific association between low handgrip strength (LGS) and dietary factors for the prevention of sarcopenia in young and middle-aged Koreans. We used data from the 2014–2017 Korea National Health and Nutrition Examination Survey of 11,635 Korean adults with LGS and normal handgrip strength (NGS). The relationship between dietary factors, e.g., nutrients, foods, and dietary patterns, and HGS was evaluated by multivariate logistic regression analyses. In men, the LGS group had a higher proportion of energy from carbohydrates and a lower proportion of energy from proteins than the NGS group. The LGS group had lower protein, niacin, phosphorus, and iron densities in their diet than the NGS group. The odds of having LGS increased as intake of vitamin B1 (odds ratio (OR) 2.916, 95% confidence interval (CI) 1.265–6.719), niacin (OR 2.286, 95% CI 1.095–4.774), phosphorus (OR 2.731, 95% CI 1.036–7.199), and iron (OR 2.591, 95% CI 1.102–6.088) decreased. In women with LGS, the odds of insufficient protein intake (OR 1.976, 95% CI 1.248–3.127) was significantly higher. This study suggests that adequate intake of protein, vitamin B1, niacin, phosphorus, and iron is beneficial for maintaining HGS

Asymmetric polystyrene-polylactide bottlebrush random copolymers: Synthesis, self-assembly and nanoporous structures

Control of polymer architecture can be a powerful strategy to refine the structure and properties without changing the chemical structure of the monomers. Here, we exploit a highly branched bottlebrush architecture to access tailored self-assembled morphologies and nanoporous structures. To this end, a series of well-defined bottlebrush random copolymers are synthesized by macromonomer approach, where polystyrene (PS) and poly(D,L-lactide) (PLA) side chains of non-equal molecular weights are grafted to the polynorbornene backbone. These bottlebrush copolymers exhibit microphase-separated structures including lamellar, hexagonal cylinders and disordered structures with the domain sizes of 13???20 nm depending on the relative volume fraction (f) of PS and PLA side chain. Due to highly asymmetric nature, these bottlebrush copolymers exhibit cylinders at f PS = 41???50% and lamellar at f PS = 67???70%, unlike the case of linear diblock copolymers. The selective degradation of PLA from these bottlebrushes allows for nanoporous structures to be created of which size, distribution and connectivity of pores are dictated by the composition of bottlebrush precursors. The ability to exploit the bottlebrush architecture to manipulate self-assembled morphologies and nanoporous structures may be a useful way to design materials for adsorptions, separations, catalysis and gas storages