Photoprotective properties of a hydrophilic extract of the fern Polypodium leucotomos on human skin cells

The effect of a hydrophilic extract of the fern Polypodium leucotomos (PLE) has been investigated in terms of photoprotection against UV-induced cell damage. PLE efficiently preserved human fibroblast survival and restored their proliferative capability when the cells were exposed to UVA light. This effect was specific and dose-dependent. Photoprotection was not restricted to fibroblasts, as demonstrated by its effect on survival and proliferation of the human keratinocyte cell line HaCat. Finally, treatment of the cells with PLE prevented UV-induced morphological changes in human fibroblasts, namely disorganisation of F-actin-based cytoskeletal structures, coalescence of the tubulin cytoskeleton and mislocalization of adhesion molecules such as cadherins and integrins. Our in vitro results demonstrate the photoprotective effect of PLE on human cells and support its use in the preventive treatment of sunburning and skin pathologies associated with UV-mediated damage.     

Study of structural and electronic transport properties of Ce-doped LaMnO3

The structural and electronic transport properties of La_1−x Ce _x MnO₃ (x=0.0–1.0) have been studied. All the samples exhibit orthorhombic crystal symmetry and the unit cell volume decreases with Ce doping. They also make a metal-insulator transition (MIT) and transition temperature increases with increase in Ce concentration up to 50% doping. The system La_0.5Ce_0.5MnO₃ also exhibits MIT instead of charge-ordered state as observed in the hole doped systems of the same composition.     

Polypodium leucotomos extract inhibits trans-urocanic acid photoisomerization and photodecomposition

In this report, we demonstrate a possible molecular mechanism by which a hydrophilic extract of the leaves of the fern Polypodium leucotomos (Fernblock, PL) blocks ultraviolet (UV)-induced skin photodamage. The extract inhibits UVA and UVB light induced photoisomerization of trans-urocanic acid (t-UCA), a common photoreceptor located in the stratum corneum, and also blocks its photodecomposition in the presence of oxidizing reagents such as H2O2, and titanium dioxide (TiO2). PL protects in vitro human fibroblasts from UV-induced death as well. These results suggest the potential of employing the PL extract as a component of sunscreen moistures in order to prevent photodecomposition of t-UCA, to inhibit UV-induced deleterious effects of TiO2 and to protect skin cells and endogenous molecules directly involved in skin immunosurveillance.     

Two connected inverse spectral transforms

We establish a transformation which connects the potentials of the one-dimensional Dirac and Klein-Gordon operators. This transformation links the solutions of the nonlinear evolution equations solvable by means of the two inverse spectral transforms which use the Dirac and Klein-Gordon direct and inverse spectral problems.