Resonant Soft X-ray Scattering Reveals the Distribution of Dopants in Semicrystalline Conjugated Polymers.

The distribution of counterions and dopants within electrically doped semicrystalline conjugated polymers, such as poly(3-hexylthiophene-2,5-diyl) (P3HT), plays a pivotal role in charge transport. The distribution of counterions in doped films of P3HT with controlled crystallinity was examined using polarized resonant soft X-ray scattering (P-RSoXS). The changes in scattering of doped P3HT films containing trifluoromethanesulfonimide (TFSI) and 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (FTCNQ) as counterions to the charge carriers revealed distinct differences in their nanostructure.

Carbosiloxane Bottlebrush Networks for Enhanced Performance and Recyclability.

Silicone bottlebrush copolymers and networks derived from cyclic carbosiloxanes are reported and shown to have enhanced properties and recyclability compared with traditional dimethylsiloxane-based materials. The preparation of these materials is enabled by the synthesis of well-defined heterotelechelic macromonomers with Si-H and norbornene chain ends via anionic ring-opening polymerization of the hybrid carbosiloxane monomer 2,2,5,5-tetramethyl-2,5-disila-1-oxacyclopentane. These novel heterotelechelic α-Si-H/ω-norbornene macromonomers undergo efficient ring-opening metathesis copolymerization to yield functional bottlebrush polymers with accurate control over molecular weight and functional-group density.

Telomere Length and Biological Aging: The Role of Strength Training in 4814 US Men and Women.

Telomere length is an index of cellular aging. Healthy lifestyles are associated with reduced oxidative stress and longer telomeres, whereas unhealthy behaviors are related to shorter telomeres and greater biological aging. This investigation was designed to determine if strength training accounted for differences in telomere length in a random sample of 4814 US adults.

Expression and Distribution of MUC1 in the Developing and Adult Kidney.

Mucin 1 (or MUC1) is a heterodimeric transmembrane glycoprotein expressed on the apical surface of polarized epithelial cells in several tissues including the kidney. Recent studies have revealed several novel roles for MUC1 in the kidney, potentially including bacterial infection, mineral balance, and genetic interstitial kidney disease, even though MUC1 levels are reduced not only in the kidney but in all tissues due to MUC1 mutations. A careful localization of MUC1 in discrete segments of the nephron is a first step in understanding the multiple functional roles of MUC1 in the kidney.

Investigating the relationship between β-carotene intake from diet and supplements, smoking, and lung cancer risk.

β-carotene is a naturally occurring and safe dietary source of vitamin A that is associated with cancer risk reductions when consumed in typical dietary amounts. However, two clinical trials reported increased incidence of lung cancer and total mortality among heavy smokers taking β-carotene supplements (20 or 30 mg/day). Based on these findings, the Joint FAO/WHO Expert Committee on Food Additives withdrew Acceptable Daily Intake values for β-carotene (0-5 mg/kg bw).