A dodecamethoxy[6]cycloparaphenylene consisting entirely of hydroquinone ethers: unveiling in-plane aromaticity through a rotaxane structure.

[n]Cycloparaphenylenes ([n]CPPs, where n is the number of phenylene groups), consisting of 1,4-linked phenylene unit, have attracted much attention due to their cyclic π-conjugated structures and physical properties. However, functionalizing of the benzene rings of smaller [n]CPPs (n < 7) has been a challenge due to ring strain and steric hindrance of the substituents that hampers their synthesis. Here we show successful synthesis of a new [6]CPP derivative with twelve methoxy groups at the 2,5-positions of all benzene rings by utilizing our developed CPP synthesis method via a macrocyclic gold complex.

Average daily intake of phosphorus in 3- to 5-year-old Japanese children as assessed by the duplicate-diet technique.

The present study aimed to determine whether there is excessive mean daily intake of phosphorus in 3- to 5-year-old Japanese children and to ascertain relationships between phosphorus intake and various food and beverage groups. Subjects comprised of 90 children, with 15 boys and 15 girls in each age group from 3 to 5 years. The duplicate-diet technique was used to ascertain total dietary intake, including snacks and beverages over a 24-h period on 3 separate days from summer 1999 to winter 2000.

Iron, zinc, manganese and copper intakes in Japanese children aged 3 to 5 years.

This study aimed to measure and evaluate the intakes for the four trace elements of Fe, Zn, Mn, and Cu in 3- to 5-y-old Japanese preschool children. The study group consisted of a total of 90 3- to 5-y-old children living in Yokkaichi, Mie, Japan. Diet samples were collected by the duplicate-portion technique on 3 d at three different seasons between summer in 1999 and winter in 2000.

Calcium, magnesium, potassium and sodium intakes in Japanese children aged 3 to 5 years.

The present study aimed to evaluate in preschool children the intakes of Ca, Mg that possibly affect health and tooth formation and the intakes of K and Na that may affect lifestyle-related diseases. Information on dietary intake was collected from 90 preschool children (15 boys and 15 girls each in the 3-, 4- and 5-year old groups) on 3 separate days in the school fiscal year 1999 (April 1999 to March 2000) by the duplicate-diet technique. The Ca, Mg, K, and Na concentrations were determined by atomic absorption spectrometry using wet-ashed samples.