Topical treatments with acylceramide dispersions restored stratum corneum lipid lamellar structures in a reconstructed human epidermis model.

Long-periodicity phase (LPP) lamellar structures in intercellular lipid matrixes of the stratum corneum (SC) are considered important for maintenance of skin permeability barriers. Acylceramides are essential components of LPP structures, and their absence influences skin barriers under physiological and pathological conditions, such as atopic dermatitis and dry skin. Although topical applications of acylceramide have been shown to facilitate maintenance of the skin barrier, it is unknown whether topically applied acylceramides are incorporated into intercellular lipids to form LPP structures.

Second-order autocorrelation of XUV FEL pulses via time resolved two-photon single ionization of He.

Second-order autocorrelation spectra of XUV free-electron laser pulses from the Spring-8 Compact SASE Source (SCSS) have been recorded by time and momentum resolved detection of two-photon single ionization of He at 20.45 eV using a split-mirror delay-stage in combination with high-resolution recoil-ion momentum spectroscopy (COLTRIMS). From the autocorrelation trace we extract a coherence time of 8 ± 2 fs and a mean pulse duration of 28 ± 5 fs, much shorter than estimations based on electron bunch-length measurements.

Ion-ion coincidence studies on multiple ionizations of N(2) and O(2) molecules irradiated by extreme ultraviolet free-electron laser pulses.

We have investigated multiple ionization of N(2) and O(2) molecules by 52 nm extreme-ultraviolet light pulses at the free-electron laser facility SCSS in Japan. Coulomb break-up of parent ions with charge states up to 5+ is found by the ion-ion coincidence technique. The charge-state dependence of kinetic energy release distributions suggests that the electrons are emitted sequentially in competition with the elongation of the bond length.

Dissociation dynamics of C(6)H(6) and C(6)H(5)F molecules following carbon 1s and fluorine 1s photoionization studied by three-dimensional momentum imaging method.

Benzene and fluorobenzene molecules were multiply ionized through Auger decay following from the C 1s or the F 1s photoionization and their subsequent dissociations were studied utilizing position-sensitive time-of-flight measurements. The angular correlation between the momenta of (H(+)-H(+)) and (H(+)-F(+)) fragment ions derived from the multiply ionized benzene or fluorobenzene clearly reflects the hexagonal structure of the parent molecules, though the dissociations are not described by the simple Coulomb explosion model. Also, analysis on the planarity between the momentum of H(+), C(+), and F(+) reveals that these three ions are emitted almost in a single plane.