Search results for "induction"
showing 10 items of 769 documents
Coordinated induction of drug transporters and phase I and II metabolism in human liver slices
2008
Although regulation of phase I drug metabolism in human liver is relatively well studied, the regulation of phase II enzymes and of drug transporters is incompletely characterized. Therefore, we used human liver slices to investigate the PXR, CAR and AhR-mediated induction of drug transporters and phase I and II metabolic enzymes. Precision-cut human liver slices were incubated for 5 or 24 h with prototypical inducers: phenobarbital (PB) (50 mu M) for CAR, beta-naphthoflavone (BNF) (25 mu M) for AhR, and rifampicin (RIF) (10 mu M) for PXR, and gene expression of the phase I enzymes CYP1A1, 1A2, 3A4, 3A5, 2136, 2A6, the phase II enzymes UGT1A1 and 1A6, and the transporters MRP2, MDR1, BSEP, …
Fen1 is induced p53 dependently and involved in the recovery from UV-light-induced replication inhibition.
2005
Mouse embryonic fibroblasts (MEFs) that lack p53 are hypersensitive to the cytotoxic and genotoxic effect of ultraviolet (UV-C) light. They also display a defect in the recovery from UV-C-induced DNA replication inhibition. An enzyme involved in processing stalled DNA replication forks is flap endonuclease 1 (Fen1). Gene expression profiling of UV-C-irradiated MEFs revealed fen1 to be upregulated, which was confirmed by RT-PCR and Western blot experiments. Increased Fen1 levels upon UV-C exposure are due to transcriptional activation, as revealed by inhibitor studies. Fen1 induction was dose- and time-dependent; it occurred on protein level already 3 h after irradiation. Induction of Fen1 b…
Resveratrol, a chemopreventive agent, disrupts the cell cycle control of human SW480 colorectal tumor cells
2002
Resveratrol is a natural polyphenolic compound produced by a number of plants and found in high amount in peanuts, seeds, grapes or berries as source of human nutrition. Epidemiological studies strongly suggest that resveratrol may act as a cancer chemopreventive compound. The mechanism by which resveratrol inhibits cell proliferation was studied in human colorectal tumor SW480 cell line. The results show that resveratrol strongly inhibits cell proliferation at the micromolar range in a time- and dose-dependent manner. Resveratrol appears to block the cell cycle at the transition --> G2/M since inhibition of [(3)H]-thymidine incorporation is not observed, while there is an increase of the c…
Photobiology in space: An experiment on Spacelab I
1984
The joint European/US Spacelab Mission I, scheduled for October 1983 for a 9 day lasting Earth-orbiting flight, provides a laboratory system for various disciplines of science, including exobiology. On the pallet, in the experiment ES 029 "Microorganisms and Biomolecules in Space Hard Environment" 316 dry samples of Bacillus subtilis spores will be exposed to space vacuum and/or selected wavelenghs of solar UV radiation. After recovery action spectra of inactivation, mutation induction, reparability and photochemical damage in DNA and protein will be determined. The results will contribute to the understanding of the mechanism of the increased UV sensitivity of bacterial spores in vacuo and…
Contactless magnetic excitation of acoustic cavitation in liquid metals
2015
A steady axial magnetic field is applied to a liquid metal zone heated by induction currents. The resulting alternating Lorentz force causes pressure oscillations that being strong enough lead to cavitation in the molten metal. Amplitude of the pressure oscillations is proportional to the product of the induced currents and the steady axial magnetic field induction. We follow an approach where the acoustic pressure is maximized by the induction currents. The onset of cavitation is identified by the occurrence of sub-harmonics of the drive frequency in sound recorded at the surface of the experimental cell. It is demonstrated that cavitation in a liquid metal may be excited by a superimposed…
High Performance FOC for Induction Motors with Low Cost ATSAM3X8E Microcontroller
2018
In this paper the Authors present the Arduino Due board application for an induction motor field oriented control (FOC) algorithm. The low cost Arduino Due board is equipped with a ATSAM3X8E microcontroller that performs the algorithm calculation, data processing, current signals and speed/position data acquisition. The control algorithm has been developed with the help of the open source Arduino integrated development environment, whereas a user friendly control interface, used to manage the speed or position set point, has been developed in Java language by means of an other open source software, namely, Processing. An experimental test bed has been set up in order to validate the FOC sys…
Selective, homogeneous hydrogenation of cycloheptatriene to cycloheptene catalyzed by (η4-cycloocta-1,5-diene)(η6-cyclohepta-1,3,5-triene)ruthenium(0)
1980
Abstract In the presence of small amounts of [Ru(η 4 -COD)](η 6 -C 8 H 10 )] (1), cycloheptatriene is hydrogenated to cycloheptene, under one atmosphere of hydrogen at room temperature in homogeneous phase. The formation of a small amount of cyclooctene and the existence of an induction period, which do not occur when [Ru(η 4 -COD)(η 6 -C 7 H 8 )] (2) is used as the catalyst, suggest that 2 is the real catalyst. The selectivity of this hydrogenation is 100% in n-hexane as solvent, 99.5% in THF, and low in ethanol. Conversion is quantitative in THF and ethanol, but not more than 65% in n-hexane. In the presence of 1 or 2, cycloheptene is rapidly hydrogenated to cycloheptane in THF and ethano…
Validation of a New Method for the Diagnosis of Rotor bar Failures via Wavelet Transformation in Industrial Induction Machines
2006
[EN] In this paper, the authors propose a method for the diagnosis of rotor bar failures in induction machines, based on the analysis of the stator current during the startup using the discrete wavelet transform (DWT). Unlike other approaches, the study of the high-order wavelet signals resulting from the decomposition is the core of the proposed method. After an introduction of the physical and mathematical bases of the method, a description of the proposed approach is given; for this purpose, a numerical model of induction machine is used in such a way that the effects of a bar breakage can clearly be shown, avoiding the influence of other phenomena not related with the fault. Afterward, …
First trimester biochemical screening for Down's syndrome in singleton pregnancies conceived by assisted reproduction
2005
BACKGROUND: Serum biochemical markers [free betahCG (fbetahCG); pregnancy-associated plasma protein-A (PAPP-A)] used in first trimester Down's syndrome screening have not been fully investigated in pregnancies achieved by assisted reproduction techniques. We present data on pregnancies conceived by all types of assisted reproduction techniques, including pregnancies following ovum donation (OD) and a large sample by ICSI. METHODS: First trimester Down's syndrome screening was performed in 1054 normal singleton pregnancies: natural conception (n = 498), ovulation induction (OS, n = 97), IVF (n = 47), ICSI (n = 222) and OD (n = 190). RESULTS: No differences in maternal levels of fbetahCG and …
Adjuncts for ovarian stimulation: when do we adopt “orphan indications” for approved drugs?
2009
Several drugs, shown to be safe for other uses, have proven to be highly effective adjuncts for ovarian stimulation. The authors evaluate these "orphan" indications and make recommendations so that more patients will benefit from their use.