Effects of Ultraviolet A-1 Radiation on Calcineurin Activity and Cytokine Production in (Skin) Cell Cultures†

Calcineurin (Cn) is the target of immunosuppressive drugs used for maintenance therapy of transplant patients. UV radiation is also known to be immunosuppressive and, like the Cn inhibitors, UV has been shown to positively influence various inflammatory skin diseases. Recently, Cn activity has been demonstrated in skin and skin cell cultures. In the present study we have investigated the effects of UV(A-1) irradiation on Cn activity in skin. In total skin we found a significant reduction in Cn activity after exposure to 450 kJ m⁻² of UVA-1 (340–400 nm). In repeated experiments cultures of fibroblasts and keratinocytes also showed dose-dependent and selective reduction in Cn activity after UVA-1 irradiation. UVB irradiation caused a decrease in the Cn activity of one of two fibroblast cultures and was ineffective in keratinocytes. In Jurkat cells and PBMC UVA-1 reduced Cn activity and also the production of cytokines such as interleukin (IL)-2, γ-interferon, IL-4 and IL-10 that are controlled by the Ca²⁺–Cn pathway. These results indicate that UV(A-1) irradiation may lead to inactivation of Cn in the skin and thus suppress the skin immune system in a similar fashion to the Cn inhibitors.     

Phase calibration of sonar systems using standard targets and dual-frequency transmission pulses

The phase angle component of the complex frequency response of a sonar system operating near transducer resonance is usually distorted. Interpretation and classification of the received sonar signal benefits from the preservation of waveform fidelity over the full bandwidth. A calibration process that measures the phase response in addition to the amplitude response is thus required. This paper describes an extension to the standard-target calibration method to include phase angle, without affecting the experimental apparatus, by using dual-frequency transmission pulses and frequency-domain data processing. This approach reduces the impact of unknown range and sound speed parameters upon phase calibration accuracy, as target phase is determined from the relationship of the two frequency components instead of relying on a local phase reference. Tungsten carbide spheres of various sizes were used to simultaneously calibrate the amplitude and phase response of an active sonar system in a laboratory tank. Experimental measurements of target phase spectra are in good agreement with values predicted from a theoretical model based upon full-wave analysis, over an operating frequency of 50-125 kHz.     

A generating function for the cubic interactions of higher spin fields

We present an off-shell generating function for all cubic interactions of higher spin gauge fields constructed in Manvelyan et al. (2010) [1]. It is a generalization of the on-shell generating function proposed by Sagnotti and Taronna [2], is written in a very compact way, and turns out to have a remarkable structure.     

Direct construction of a cubic selfinteraction for higher spin gauge fields

Using Noether's procedure we directly construct a complete cubic selfinteraction for the case of spin s=4$s=4$ in a flat background and discuss the cubic selfinteraction for general spin s with s derivatives in the same background. The leading term of the latter interaction together with the leading gauge transformation of first field order are presented.     

Sufficient conditions for Willmore immersions in \mathbb{R }^3 to be minimal surfaces

We provide two sharp sufficient conditions for immersed Willmore surfaces in $\mathbb{R }^3$ to be already minimal surfaces, i.e. to have vanishing mean curvature on their entire domains. These results turn out to be particularly suitable for applications to Willmore graphs. We can therefore show that Willmore graphs on bounded $C^4$ -domains $\overline{\varOmega }$ with vanishing mean curvature on the boundary $\partial \varOmega $ must already be minimal graphs, which in particular yields some Bernstein-type result for Willmore graphs on $\mathbb{R }^2$ . Our methods also prove the non-existence of Willmore graphs on bounded $C^4$ -domains $\overline{\varOmega }$ with mean curvature $H$ satisfying $H \ge c_0>0 \,{\text{ on }}\, \partial \varOmega $ if $\varOmega $ contains some closed disc of radius $\frac{1}{c_0} \in (0,\infty )$ , and they yield that any closed Willmore surface in $\mathbb{R }^3$ which can be represented as a smooth graph over $\mathbb{S }^2$ has to be a round sphere. Finally, we demonstrate that our results are sharp by means of an examination of some certain part of the Clifford torus in $\mathbb{R }^3$ .     

Electronic and magnetic properties of double perovskites (, Ca)

We have studied the magnetic and electronic properties of double perovskites A₂FeReO₆ with A=Ba and Ca using ab initio methods based on density functional theory. It has been shown that when changing Ba by Ca the system undergoes a metal–insulator transition coincidentally to a structural phase transition, even if conduction band fillings are not significantly changed. Our results suggest that only considering a quite large correlation term on the Re site could explain an insulating character for Ca₂FeReO₆. Instead, we found that small correlations could induce a bad metallic behavior as suggested in more recent experiments.     

Preparation of self-supporting mesostructured silica thin film membranes as gateable interconnects for microfluidics

A methodology for the preparation of self-standing 100–200 nm thick mesoporous silica membrane interconnects is reported. Interconnects may become an important component in future microfluidic device technology since it allows extension of microfluidic architectures into the third dimension. The silica film was mechanically supported by a perforated silicon nitride microsieve and covered a hexagonal array of 500 nm-sized holes. The potential applicability of these films as gateable interconnects for controlled dosing of ions was demonstrated. The permeability of ionic species can be controlled by the ionic strength.     

Fission neutron multiplicity versus fragment mass and kinetic energy

High spin states of ¹²⁷ Ba have been investigated by means of the OSIRIS anti-compton γ -spectrometer. Five new bands, 48levels and 77transitions were found. Spin suggestions for four bandheads could be given. On ground of these suggestions routhians and alignments were compiled for the observed bands, giving a first insight into the high spin structure of this nucleus.     

The retro-aldol mechanism in the pyrolysis kinetics of primary,secondary, and tertiary β-hydroxy ketones in the gas phase

The pyrolysis kinetics of primary, secondary, and tertiary β-hydroxy ketones have been studied in static seasoned vessels over the pressure range of 21–152 torr and the temperature range of 190°–260°C. These eliminations are homogeneous, unimolecular, and follow a first-order rate law. The rate coefficients are expressed by the following equations: for 1-hydroxy-3-butanone, log k₁(s^?1) = (12.18 ± 0.39) ? (150.0 ± 3.9) kJ mol^?1 (2.303RT)^?1; for 4-hydroxy-2-pentanone, log k₁(s^?1) = (11.64 ± 0.28) ? (142.1 ± 2.7) kJ mol^?1 (2.303RT)^?1; and for 4-hydroxy-4-methyl-2-pentanone, log k₁(s^?1) = (11.36 ± 0.52) ? (133.4 ± 4.9) kJ mol^?1 (2.303RT)^?1. The acid nature of the hydroxyl hydrogen is not determinant in rate enhancement, but important in assistance during elimination. However, methyl substitution at the hydroxyl carbon causes a small but significant increase in rates and, thus, appears to be the limiting factor in a retroaldol type of mechanism in these decompositions. © John Wiley & Sons, Inc.