Regulation of the interferon-inducible protein kinase PKR and (2''-5'')oligo(adenylate) synthetase by a catalytically inactive PKR mutant through competition for double-stranded RNA binding

This study evaluated the long-term effect of an ultrasonic toothbrush used as part of a daily oral hygiene regimen on supragingival plaque, gingivitis, and gingival bleeding. Compared with a conventional toothbrush, the ultrasonic toothbrush was significantly more effective in reducing plaque formation (p < 0.05), removing plaque (p < 0.05), and reducing gingivitis (p < 0.05) during the 6-month study period.     

Zur Frage der drucklosen Messung der elektrischen Leitfähigkeit von pulverförmigen Werkstoffen

Contribution to the Problem of Pressure-less Measurements of the Electric Conductivity of Powder Materials Two authors (1, 2) proposed to use the electric conductivity of a loosely packed powder bed as the electric characteristics of the power material. The authors got reproducible and intercomparable results applying their method on various oxide powders, e.g. reduced MnO₂ and mixed oxides. This is in contradiction to the common experience that in the range of small pressure, reliable results hardly can be obtained. Obviously, some special conditions have made the good results possible. Here below, the pressure-less method has been applied to four different powders: a species of MnO₂, copper, Cd(OH)₂ and PbO₂. As the principal result, it has to be stated that the pressure-less method delivers reliable results only in the case of such powders, whose grain core resistance doesn't have to be neglected against the contact resistance between the grains. This condition is fulfilled here only in the case of manganese dioxide. Probably, the oxide powders under study in (1, 2) also have been in the correct range. In spite of this, the pressure-less method may not be applied on metal powders or on the metal-likek PbO₂ powder. Also in the case of Cd(OH)₂ masses, severe objections exist.     

Ether lipid derivatives: Antineoplastic activity in vitro and the structure-activity relationship

The antineoplastic activity of two ether lipid derivatives, the alkyl-lysophospholipid derivative (ALP) ET-18-OCH₃ and the ether-linked lipoidal amine CP-46,665 was tested in a human tumor clonogenic assay (HTCA) in vitro. CP-46,665 suppresed the colony formation of various human tumors with a slight dose response relation after 1 hr incubation and with a clear optimum (85% response rate) after continuous exposure in the higher dose range tested (10 μg/ml). ET-18-0CH₃ did not have substantial activity after 1 hr of incubation. However, when continuous exposure to the compound was used, ET-18-OCH₃ seemed to have a modest dose response effect and yielded a response in about 60% of the tumor cell samples tested in the higher dose range (10 μg/ml). Thus, both compounds have in vitro antitumor activity in the HTCA within a dose range of 1–10 μg/ml, especially during continuous exposure. The tumor specific type activity was found in breast cancer, ovarian cancer, lung cancer and mesothelioma. Both compounds caused decreases in colony formation down to the 0%, 2% and 4% levels. In a comparison of specimens in which both compounds were used, only one of five times showed a discordance in sensitivity or resistance; therefore the compounds appear similar in their in vitro activity. In a second set of experiments we tested the structure-activity relationship among a variety of ALP in the [³H]thymidine incorporation assay after incubation with HL-60 leukemic blasts and other neoplastic cells from human origin. From these studies it can be concluded that in the ALP the alkyl linkage in the sn-1 position is a necessary prerequisite for cytotoxicity; furthermore, in the majority of tumors tested the substitution of the sn-2 position to prevent reacylation of the molecule is necessary for cytotoxicity.     

Examination of C/C flat tile mock-ups with hypervapotron cooling after high heat flux testing

Two C/C flat tile mock-ups with a hypervapotron cooling concept, have been successfully tested beyond ITER specification (3000 cycles at 15 MW/m², 300 cycles at 20 MW/m² and 800-1000 cycles at 25 MW/m²) in two electron beam testing facilities [F. Escourbiac, et al., Experimental simulation of cascade failure effect on tungsten and CFC flat tile armoured HHF components, Fusion Eng. Des., submitted for publication; F. Escourbiac, et al., A mature industrial solution for ITER divertor plasma facing components: hypervapotron cooling concept adapted to Tore Supra flat tile technology, Fusion Eng. Des. 75-79 (2005) 387-390]. Both mock-ups provide a SNECMA SEPCARB^® NS31 armour, which has been joined onto the CuCrZr heat sink by active metal casting (AMC) and electron beam welding (EBW). No tile detachment or sudden loss of single tiles has been observed; a cascade-like failure of flat tile armours was impossible to generate. At the maximum cyclic heat flux load of 25 MW/m² all tested tiles performed well except one, which revealed already a clear indication in the thermographic examination at the end of the manufacture. Visual examination and analysis of metallographic cuts of the remaining tiles demonstrated that the interface has not been altered. In addition, the shear strength of the C/C to copper joints measured after the high heat flux (HHF) test has been found to be still above the interlamellar shear strength of the used C/C material. The high resistance of the interface is explained by a modification of the C/C to copper joint interface due to silicon originating from the used C/C material.     

Coalgebraic semantics of modal logics: An overview

Coalgebras can be seen as a natural abstraction of Kripke frames. In the same sense, coalgebraic logics are generalised modal logics. In this paper, we give an overview of the basic tools, techniques and results that connect coalgebras and modal logic. We argue that coalgebras unify the semantics of a large range of different modal logics (such as probabilistic, graded, relational, conditional) and discuss unifying approaches to reasoning at this level of generality. We review languages defined in terms of the so-called cover modality, languages induced by predicate liftings as well as their common categorical abstraction, and present (abstract) results on completeness, expressiveness and complexity in these settings, both for basic languages as well as a number of extensions, such as hybrid languages and fixpoints.     

Carbonyl compounds methylglyoxal and glyoxal affect interleukin‐8 secretion in intestinal cells by superoxide anion generation and activation of MAPK p38

The carbonyl compounds methylglyoxal (MG) and glyoxal (GL) are reactive intermediates of glucose degradation pathways and capable of inducing cellular damage. Although immune‐stimulating activity has been investigated in endothelial cells, little is known about the signaling pathways of cytokine induction of these compounds in the intestine. Hence, we investigated the impact of mitogen‐activated protein kinases (MAPK) and nuclear factor kappa B (NF‐κB) on IL‐8 production by human intestinal cells (Caco‐2 and HT‐29) after stimulation by MG and GL. Both compounds induced a dose‐dependent enhancement of IL‐8 secretion in human intestinal cells. MAPK p38 and extracellular signal‐regulated kinase (ERK) were phosphorylated in these cells after having been stimulated by MG and GL. Furthermore, inhibitors of MAPK p38 (SB 203580 and 239063), ERK1/2 (PD 98059) and NF‐κB activation (SM‐7368 and SC‐514) reduced IL‐8 secretion. The most important mechanism by which MG and GL induced IL‐8 secretion was the generation of superoxide anions which was confirmed by the inhibition of the cytosolic NADPH oxidase with diphenyl iodonium (DPI) or by application of superoxide dismutase (SOD). Our data suggest that multiple pathways were simultaneously activated; however, superoxide dependent MAPK p38 activation seems to be the most dominant pathway for IL‐8 secretion in intestinal cells.     

Aeroacoustic source term computation based on radial basis functions

In low Mach number aeroacoustics, the known disparity of length scales makes it possible to apply well-suited simulation models using different meshes for flow and acoustics. The workflow of these hybrid methodologies include performing an unsteady flow simulation, computing the acoustic sources, and simulating the acoustic field. Therefore, hybrid methods seek for robust and flexible procedures, providing a conservative mesh to mesh interpolation of the sources while ensuring high computational efficiency. We propose a highly specialized radial basis function interpolation for the challenges during hybrid simulations. First, the computationally efficient local radial basis function interpolation in conjunction with a connectivity-based neighbor search technique is presented. Second, we discuss the computation of spatial derivatives based on radial basis functions. These derivatives are computed in a local-global approach, using a Gaussian kernel on local point stencils. Third, radial basis function interpolation and derivatives are used to compute complex aeroacoustic source terms. These ingredients are necessary to provide flexible source term calculations that robustly connect flow and acoustics. Finally, the capabilities of the presented approach are shown in a numerical experiment with a co-rotating vortex pair.     

Thermal Impact on the Human Oral Cavity Exposed to Radiation from Biomedical Devices Operating in the Terahertz Frequency Range

New medical applications, e.g., aiming at cancer research support, are currently extending the number of technical systems operating in the terahertz (THz) frequency range. This field of applications results in potentially exposed body areas, which have not been taken into account in earlier literature according to exposure assessments at THz frequencies. Due to the small penetration depths in the regarded frequency range, between a few 100 and some micrometers at 0.1 and 10 THz respectively, it was adequate in former analyses to consider near-surface body tissues, e.g., the human eyes or the skin while being exposed to electromagnetic fields. Now, the consideration of body internal tissues becomes necessary since small mobile medical devices can potentially expose tissues underneath the body surface, e.g., inside the oral cavity. In this paper, a multi-level approach is employed in order to estimate electric field strengths and temperature elevations in the human oral cavity by use of numerical computations. Moreover, the urgently needed dielectric properties of the considered tissues, which are not yet available in published databases, are provided here.