title: Structural analysis of human hair single fibres by scanning microbeam SAXS.
abstract: The origin of the curliness of human hair was revealed by scanning microbeam small angle X-ray scattering (SAXS), based on the nanostructure of keratin fibre arrangement. Scanning microbeam SAXS patterns of single hair fibres have been measured across the fibres and the differences in the patterns between the inner and the outer sides of the curvature were successfully detected. The analysis of the equatorial and azimuthal scattering intensity profiles showed that the arrangement of the intermediate filaments was different between the inner and the outer sides of the curvature. From the analogy with Merino and Romny wool, it is suggested that different types of cortices exist in human hair. It is concluded that, regardless of the ethnic origins (African, Caucasian, and Asian), the macroscopic curl shape of the hair fibre originate from the inhomogeneity of the internal nanostructure, arising from inhomogeneous distribution of two types of cortices.
authors.affiliation: Hair Care Research Laboratories, Kao Corporation, 2-1-3, Bunka, Sumida-ku, Tokyo 131-8501, Japan. kajiura.yoshio@kao.co.jp
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Kajiura
authors.forename: Shunichi
authors.initials: S
authors.lastname: Watanabe
authors.forename: Takashi
authors.initials: T
authors.lastname: Itou
authors.forename: Koichi
authors.initials: K
authors.lastname: Nakamura
authors.forename: Atsuo
authors.initials: A
authors.lastname: Iida
authors.forename: Katsuaki
authors.initials: K
authors.lastname: Inoue
authors.forename: Naoto
authors.initials: N
authors.lastname: Yagi
authors.forename: Yuya
authors.initials: Y
authors.lastname: Shinohara
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Amemiya
mesh_terms: D001741:Black or African American; D044466:Asian People; D005006:Ethnicity; D006197:Hair / Q000737:chemistry*; D018859:Hair Follicle / Q000737:chemistry*; D006801:Humans; D044468:Native Hawaiian or Pacific Islander; D012372:ROC Curve; D044465:White People; D014961:X-Ray Diffraction / Q000379:methods*