Impact of Long‐Wavelength Ultraviolet A1 and Visible Light on Light‐Skinned Individuals

Solar radiation is known to be a major contributor to the development of skin cancer. Most sunscreen formulations, including those with broad spectrum, offer minimal protection in long‐wavelength ultraviolet A1 (UVA1; 370–400 nm) and visible light (VL; 400–700 nm) domain. There is limited information regarding the impact of this broad waveband (VL + UVA1, 370–700 nm) on those with light skin. In this study, ten healthy adult subjects with Fitzpatrick skin phototypes I–III were enrolled. On day 0, subjects' lower back was exposed to a VL + UVA1 dose of 480 J cm^?2. A statistically significant increase in erythema immediately after irradiation compared with subjects' baseline nonirradiated skin was observed. Clinically perceptible erythema with VL + UVA1 is a novel finding since the erythemogenic spectrum of sunlight has primarily been attributed to ultraviolet B and short‐wavelength ultraviolet A (320–340 nm). The results emphasize the need for protection against this part of the solar spectra and warrant further investigation.     

Relativistic symmetry of position-dependent mass particle in Coulomb field including tensor interaction

The spatially-dependent mass Dirac equation is solved exactly for attractive scalar and repulsive vector Coulomb potentials including a tensor interaction under the spin and pseudospin symmetric limit. Closed forms of the energy eigenvalue equation and wave functions are obtained for arbitrary spin-orbit quantum number κ. Some numerical results are given too. The effect of the tensor interaction on the bound states is presented. It is shown that the tensor interaction removes the degeneracy between two states in the spin doublets. We also investigate the effects of the spatially-dependent mass on the bound states under the conditions of the spin symmetric limit in the absence of tensor interaction.     

Diketene as an alternative substrate for a new Biginelli-like multicomponent reaction: one-pot synthesis of 5-carboxamide substituted 3,4-dihydropyrimidine-2(1H)ones

5-Carboxamide substituted 3,4-dihydropyrimidine-2(1H)one derivatives were synthesized in a simple and efficient method from the one-pot four-component reactions of an aliphatic or aromatic amine, diketene, an aromatic aldehyde and urea or thiourea in the presence of p-toluenesulfonic acid as a catalyst under mild reaction conditions at ambient temperature.     

Approximate Relativistic Bound State Solutions of the Tietz–Hua Rotating Oscillator for Any κ-State

Approximate analytical solutions of the Dirac equation with Tietz–Hua (TH) potential are obtained for arbitrary spin–orbit quantum number κ using the Pekeris approximation scheme to deal with the spin–orbit coupling terms κ(κ ± 1)r ^?2. In the presence of exact spin and pseudo-spin symmetric limitation, the bound state energy eigenvalues and associated two-component wave functions of the Dirac particle moving in the field of attractive and repulsive TH potential are obtained using the parametric generalization of the Nikiforov–Uvarov method. The cases of the Morse potential, the generalized Morse potential and non-relativistic limits are studied.     

Narrow-band UVB induces apoptosis in human keratinocytes

Narrow-band ultraviolet (NB-UVB) phototherapy emits mostly 311/312 nm light and is commonly used in the treatment of inflammatory skin disorders. As a source of UVB irradiation, NB-UVB causes apoptosis in T lymphocytes but its effects on keratinocytes are unknown. Herein, we have investigated the ability of NB-UVB to induce apoptosis in keratinocytes. Two types of human keratinocytes, primary and immortalized, were exposed to NB-UVB and broad-band UVB (BB-UVB; 315-280 nm) and tested for apoptosis. Both UVB light sources induced apoptosis in keratinocytes as determined by the presence of DNA ladders, although NB-UVB required approximately ten fold higher doses; NB-UVB (1000 mJ/cm2) and BB-UVB (125 mJ/cm2). By comparison, lower doses of NB-UVB (750 mJ/cm2) induced apoptosis in T lymphocytes, suggesting cell type specificity for NB-UVB induced apoptosis. Approximately, 50% or more of the cells underwent apoptosis when exposed to NB-UVB or BB-UVB as revealed by TUNEL assay. Electron micrographs showed that NB-UVB irradiated keratinocytes contained marked chromatin condensation, extensive cytoplasmic vacuolization and fragmentation of the nuclear envelope. Furthermore, Western blot analysis confirmed the presence of activated products of caspase 3 in keratinocytes that received apoptotic doses of NB-UVB. This study defines conditions by which NB-UVB irradiation causes apoptosis in keratinocytes.     

A novel three-component method for the synthesis of triazolo[1,2-a]indazole-triones

An efficient synthesis of triazolo[1,2-a]indazole-1,3,8-trione derivatives based on the three-component condensation of urazole, dimedone and aromatic aldehydes under solvent-free conditions is described.     

Catalyst-free rapid synthesis of benzo[4,5]imidazo[1,2-a]-pyrimidine-3-carboxamides via four-component coupling in one pot

A new class of fused tricyclic benzo[4,5]imidazo[1,2-a]-pyrimidine-3-carboxamide derivatives was synthesized via an environmentally benign one pot sequential four-component condensation reaction of an amine, 2,2,6-trimethyl-4H-1,3-dioxin-4-one, an aldehyde and 1H-benzo[d]imidazol-2-amine without using catalyst in good yields.     

The rotation‐vibration spectrum of diatomic molecules with the tietz‐hua rotating oscillator

The Tietz‐Hua (TH) potential is one of the very best analytical model potentials for the vibrational energy of diatomic molecules. By using the Nikiforov‐Uvarov method, we have obtained the exact analytical s‐wave solutions of the radial Schrödinger equation for the TH potential. The energy eigenvalues and the corresponding eigenfunctions are calculated in closed forms. Some numerical results for diatomic molecules are also presented. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011     

Visible light transmission properties of double metal thin gold films with sub-wavelength hole arrays

The transmission spectrum of linearly polarized visible light through double metal thin films perforated with nano-hole arrays is investigated and simulated by using the three dimensional finite-difference time-domain method. The results show that the transmission spectra can be controlled by changing the longitudinal interval G between films and, their lateral displacements L_x and L_y, which are parallel and perpendicular to the polarization direction of the incident light, respectively. We have two important peaks (due to guided mode and SP mode) in these spectrums. The variation in longitudinal distance results a wavelength shift in guided mode peak of transmission spectrum while the wavelength of SP mode peak remains fixed. The lateral displacement L_x leads to the higher transmission of the guided mode peak, while the lateral displacement L_y suppresses the transmission of this peak. Here we try to discuss the physical explanations of these spectral behaviours by surface plasmon waves on the metal films and by using the concepts of surface plasma (SP) and guided modes in our double metal structure.