Technical University of Dortmund

About: Technical University of Dortmund is a education organization based out in Dortmund, Nordrhein-Westfalen, Germany. It is known for research contribution in the topics: Large Hadron Collider & Neutrino. The organization has 13028 authors who have published 27666 publications receiving 615557 citations. The organization is also known as: Dortmund University & University of Dortmund.

Selenium-mediated inhibition of transcription factor NF-kappa B and HIV-1 LTR promoter activity.

Abstract: The eukaryotic transcription factor NF-κB is involved in the inducible expression of various inflammatory genes as well as in HIV-1 replication. Activation of NF-κB is induced by prooxidants and several stimuli eliciting oxidative stress, such as cytokines, lipopolysaccharide, UV irradiation and other mediators. Various antioxidants inhibit NF-κB activation in response to these stimuli. In this study, we have investigated the effects of selenium, an integral component of glutathione peroxidase (GPX), on NF-κB activation. In selenium-deprived Jurkat and ESb-L T lymphocytes, supplementation of selenium led to a substantial increase of GPX activity. Analysis of DNA binding revealed that NF-κB activation in response to TNF was significantly inhibited under these conditions. Likewise, reporter gene assays using luciferase constructs driven by the HIV-1 long terminal repeat showed a dose-dependent inhibition of NF-κB controlled gene expression by selenium. The effects of selenium were specific for NF-κB, since the activity of the transcription factor AP-1 was not suppressed. These data suggest that selenium supplementation may be used to modulate the expression of NF-κB target genes and HIV-1.

Cloaking of Small Objects by Anomalous Localized Resonance

Abstract: We investigate solutions of ∇ · (a∇u) = 0 with various boundary conditions. The coefficient a is assumed to have a real part with changing sign and a small, non-negative imaginary part of order η. We investigate a two-dimensional ring geometry with unit inner radius and outer radius R. We use Fourier expansions in polar coordinates to analyze the qualitative behaviour of solutions when boundary conditions are imposed on a small circular inclusion, centred at x 0 . Our result is that u depends qualitatively on the position of the inclusion. If lx 0 l is larger than the cloaking radius R * = R 3/2 , then u behaves as if no ring were present. If, instead, lx 0 l < R*, then the small inclusion is invisible in the limit η→ 0.

The development of the noise sensitivity questionnaire.

Abstract: The existing questionnaires for determining the noise sensitivity of individuals provide information only about global noise sensitivity, although empirical data suggest that measuring noise sensitivity for different situations in daily life might be more logical. Therefore, the "Noise-Sensitivity-Questionnaire" (NoiSeQ) was developed to measure global noise sensitivity as well as the sensitivity of five domains of daily life, namely, leisure, work, habitation, communication, and sleep. The assessment of the measurement characteristics was based on the Generalizability (G) theory. The results of the G-study (N=66) proved that a single application of the questionnaire is sufficient for determining an individual's noise sensitivity. Furthermore, the ratings are age and gender independent. The subsequently conducted Decision (D)-study (N=288) provides information on the reliability of NoiSeQ. If the questionnaire is used for measuring global noise sensitivity, the reliability (relative and absolute G-coefficient) reaches a value above 0.90. According to ISO 10075-3, the questionnaire satisfies the precision level 1 "accurate measurement" in this case. The G-coefficients for all the subscales exceed the lower limit 0.70, with the exception of subscale leisure, which did not prove satisfactory. However, this subscale can reach a reliability of more than 0.70 if additional items are included. The validity of the instrument was proven for the subscales habitation (N=72) and work (N=72). In both the studies, the participants were asked to rate the annoyance in the presence of several rail and traffic noise scenarios. The subjects were characterized as low and high noise sensitive according to their sensitivity values obtained from NoiSeQ. In conclusion, a significant difference in annoyance rates was observed between the low and high noise sensitive groups for both the subscales habitation and work. This data support the validity of NoiSeQ.

Effects of Pressure-Induced Membrane Phase Transitions on Inactivation of HorA, an ATP-Dependent Multidrug Resistance Transporter, in Lactobacillus plantarum

Abstract: The effects of pressure on cultures of Lactobacillus plantarum were characterized by determination of the viability and activity of HorA, an ATP-binding cassette multidrug resistance transporter. Changes in the membrane composition of L. plantarum induced by different growth temperatures were determined. Furthermore, the effect of the growth temperature of a culture on pressure inactivation at 200 MPa was determined. Cells were characterized by plate counts on selective and nonselective agar after pressure treatment, and HorA activity was measured by ethidium bromide efflux. Fourier transform-infrared spectroscopy and Laurdan fluorescence spectroscopy provided information about the thermodynamic phase state of the cytoplasmic membrane during pressure treatment. A pressure-temperature diagram for cell membranes was established. Cells grown at 37°C and pressure treated at 15°C lost >99% of HorA activity and viable cell counts within 36 and 120 min, respectively. The membranes of these cells were in the gel phase region at ambient pressure. In contrast, cells grown at 15°C and pressure treated at 37°C lost >99% of HorA activity and viable cell counts within 4 and 8 min, respectively. The membranes of these cells were in the liquid crystalline phase region at ambient pressure. The kinetic analysis of inactivation of L. plantarum provided further evidence that inactivation of HorA is a crucial step during pressure-induced cell death. Comparison of the biological findings and the membrane state during pressure treatment led to the conclusion that the inactivation of cells and membrane enzymes strongly depends on the thermodynamic properties of the membrane. Pressure treatment of cells with a liquid crystalline membrane at 0.1 MPa resulted in HorA inactivation and cell death more rapid than those of cells with a gel phase membrane at 0.1 MPa.