BACKGROUND Solar ultraviolet (UV) radiation causes various deleterious effects, and UV blockage is recommended for avoiding sunburn. Nanosized titanium dioxide and zinc oxide offer effective protection and enhance cosmetic appearance but entail health concerns regarding their photocatalytic activity, which generates reactive oxygen species. These concerns are absent in nanodiamonds (NDs). Among...

Xeroderma Pigmentosum (XP) is a rare autosomal recessive (AR) disease characterized by hypersensitivity of the skin to ultra violet (UV) radiation, resulting in a high frequency of UV induced skin tumors and progressive neurological complications at an early age. Through the following case report we emphasize that perioperative management of xeroderma patients entails meticulous evaluation for ...

Quasar accretion disc winds observed via broad absorption lines (BALs) in the UV produce strong continuous absorption in X-rays. The X-ray absorber is believed to serve critically as a radiative shield to keep the outflow ionizations low enough for radiative driving. However, previous studies have shown that ‘mini-BAL’ and narrow absorption line (NAL) outflows have dramatically less X-ray absor...

Based upon a novel paradigm of the galaxy formation under UV background, the evolutionary bifurcation of pregalactic clouds is confronted with observations on elliptical and spiral galaxies. The theory predicts that the dichotomy between the dissipational and dissipationless galaxy formation stems from the degree of self-shielding from the UV background radiation. This is demonstrated on a bifu...

K. T. Faber Department of Materials Science and Engineering, Northwestern University Evanston, IL 60208 There is experimental evidence that stress-induced microcracking near a macrocrack tip enhances thefraclUre toughness of brittle materials. In considering the interaction of the macrocrack with multiple microcracks using a discrete model, it is essential to use approximation methods in order ...

Dispersing nanoparticles in a polymer matrix is intrinsically challenging due to unfavorable entropic interactions between the matrix and the nanoparticle. In this research dispersion of nanoparticles in polymer matrix was studied and the effect of dispersion on properties was investigated. The properties of polymer composite depend on the type, size, shape, concentration of nanoparticles, and ...

UV-induced DNA lesions are important contributors to mutagenesis and cancer, but it is not fully understood how the chromosomal landscape influences UV lesion formation and repair. Genome-wide profiling of repair activity in UV irradiated cells has revealed significant variations in repair kinetics across the genome, not only among large chromatin domains, but also at individual transcription f...

Studies were conducted on three herbaceous plant species growing in naturally high solar UV environments in the subalpine of Mauna Kea, Hawaii, USA, to determine if diurnal changes in epidermal UV transmittance (T(UV)) occur in these species, and to test whether manipulation of the solar radiation regime could alter these diurnal patterns. Additional field studies were conducted at Logan, Utah,...

We describe a phenomenological model for molecular hydrogen formation suited for applications in galaxy formation simulations, which includes non-equilibrium formation of H2 on dust and approximate treatment of both its self-shielding and shielding by dust from the dissociating UV radiation. The model is applicable in simulations in which individual star forming regions – the giant molecular co...