Research Interests:
Research Interests:
Research Interests:
There is still uncertainty whether extremely low frequency electromagnetic fields (ELF-EMF) can induce health effects like immunomodulation. Despite evidence obtained in vitro, an unambiguous association has not yet been established in... more
There is still uncertainty whether extremely low frequency electromagnetic fields (ELF-EMF) can induce health effects like immunomodulation. Despite evidence obtained in vitro, an unambiguous association has not yet been established in vivo. Here, mice were exposed to ELF-EMF for 1, 4, and 24 h/day in a short-term (1 week) and long-term (15 weeks) set-up to investigate whole body effects on the level of stress regulation and immune response. ELF-EMF signal contained multiple frequencies (20-5000 Hz) and a magnetic flux density of 10 μT. After exposure, blood was analyzed for leukocyte numbers (short-term and long-term) and adrenocorticotropic hormone concentration (short-term only). Furthermore, in the short-term experiment, stress-related parameters, corticotropin-releasing hormone, proopiomelanocortin (POMC) and CYP11A1 gene-expression, respectively, were determined in the hypothalamic paraventricular nucleus, pituitary, and adrenal glands. In the short-term but not long-term expe...
Research Interests:
We are increasingly exposed to low-frequency electromagnetic fields (LF EMFs) by electrical devices and power lines, but if and how these fields interact with living cells remains a matter of debate. This study aimed to investigate the... more
We are increasingly exposed to low-frequency electromagnetic fields (LF EMFs) by electrical devices and power lines, but if and how these fields interact with living cells remains a matter of debate. This study aimed to investigate the potential effect of LF EMF exposure on calcium signalling in neutrophils. In neutrophilic granulocytes, activation of G-protein coupled receptors leads to efflux of calcium from calcium stores and influx of extracellular calcium via specialised calcium channels. The cytoplasmic rise of calcium induces cytoskeleton rearrangements, modified gene expression patterns, and cell migration. If LF EMF modulates intracellular calcium signalling, this will influence cellular behaviour and may eventually lead to health problems. We found that calcium mobilisation upon chemotactic stimulation was not altered after a short 30 min or long-term LF EMF exposure in human neutrophil-like cell lines HL-60 or PLB-985. Neither of the two investigated wave forms (Immunent and 50 Hz sine wave) at three magnetic flux densities (5 μT, 300 μT, and 500 μT) altered calcium signalling in vitro. Gene-expression patterns of calcium-signalling related genes also did not show any significant changes after exposure. Furthermore, analysis of the phenotypical appearance of microvilli by scanning electron microscopy revealed no alterations induced by LF EMF exposure. The findings above indicate that exposure to 50 Hz sinusoidal or Immunent LF EMF will not affect calcium signalling in neutrophils in vitro. Bioelectromagnetics. 2015;9999:XX-XX. © 2015 Wiley Periodicals, Inc.
Research Interests:
Electromagnetic fields (EMFs) of different types (static and time varying, continuous and pulsed), with a wide frequency range (1 Hz – 70 GHz) and with a broad intensity range (1 μT – 15 T) have been reported to interact with immune... more
Electromagnetic fields (EMFs) of different types (static and time varying, continuous and pulsed), with a wide frequency range (1 Hz – 70 GHz) and with a broad intensity range (1 μT – 15 T) have been reported to interact with immune cells. However, most of the publications lack the basic information, which would explain the choice of a particular signal.
Research Interests:
Research Interests:
Research Interests: Finite Element Methods, Biomagnetism, Electrostatics, Chitosan, Finite element method, and 15 moreElectromagnetics, DNA, Finite Element Analysis, Cell line, Animals, Electromagnetic Induction, Electromagnetic Fields, Detectors, Current Density, Electromagnetic Field, Glycosaminoglycans, Chondrocytes, Electric Field, Cell Survival, and Environmental Exposure
Research Interests: Immunology, Cytokines, Bioelectromagnetics, Biological Sciences, Cell line, and 15 moreHumans, Mycobacterium tuberculosis, Electromagnetic Fields, Candida albicans, Differentiation, Electromagnetic Field, Aspergillus fumigatus, Molecular sciences, Cytokine, Immune system, Ligands, Biochemistry and cell biology, Cytotechnology, Interleukin, and Medical and Health Sciences
Research Interests:
Research Interests:
A new method for fast magnetic resonance imaging is presented. It provides a more rapid data acquisition than two-dimensional Fourier imaging (2DFI) by a factor which may be chosen depending on the required signal-to-noise ratio of the... more
A new method for fast magnetic resonance imaging is presented. It provides a more rapid data acquisition than two-dimensional Fourier imaging (2DFI) by a factor which may be chosen depending on the required signal-to-noise ratio of the image. In addition to the readout gradient of 2DFI, the present method employs an oscillating modulation gradient. In this way, a curved alternating trajectory in k space is sampled after each spin excitation. For a p-times accelerated data acquisition, the trajectory consists of p periods, where p is of the order of 2 to 8 for low-frequency gradient modulation but can be chosen higher if certain hardware requirements are met. Adequate sampling density in k space is obtained by scanning shifted trajectories after subsequent spin excitations. The method can be combined with volume imaging (3DFI) and multiple slice 2DFI. It was implemented on a standard Philips Gyroscan system without any hardware modifications. Results obtained for an acceleration factor p = 4 are shown.
Research Interests:
Research Interests:
Research Interests:
An MR imaging technique has been developed producing head and body images of diagnostic quality in only a few seconds acquisition time. The Fourier type imaging technique uses excitation with relatively small excitation angels, echoes... more
An MR imaging technique has been developed producing head and body images of diagnostic quality in only a few seconds acquisition time. The Fourier type imaging technique uses excitation with relatively small excitation angels, echoes produced by gradient inversion, and extremely fast profile repetition. A typical result at 0.5 T is an artifact-free head image of 128 x 128 resolution, 10 mm slice thickness in an acquisition time of 2 seconds.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests: Immunology, Cytokines, Bioelectromagnetics, Biological Sciences, Cell line, and 15 moreHumans, Mycobacterium tuberculosis, Electromagnetic Fields, Candida albicans, Differentiation, Electromagnetic Field, Aspergillus fumigatus, Molecular sciences, Cytokine, Immune system, Ligands, Biochemistry and cell biology, Cytotechnology, Interleukin, and Medical and Health Sciences
Research Interests: Immunology, Cytokines, Bioelectromagnetics, Biological Sciences, Cell line, and 15 moreHumans, Mycobacterium tuberculosis, Electromagnetic Fields, Candida albicans, Differentiation, Electromagnetic Field, Aspergillus fumigatus, Molecular sciences, Cytokine, Immune system, Ligands, Biochemistry and cell biology, Cytotechnology, Interleukin, and Medical and Health Sciences
Research Interests: Engineering, Kinetics, Cytokines, Inflammation, Bioelectromagnetics, and 15 moreMacrophages, Innate immunity, Gene expression, Low Frequency, Biological Sciences, Cell line, Humans, Electromagnetic Fields, Electromagnetic Field, Human health, Biological systems, Epithelial cells, Monocytes, Health Effect, and Complex multiplication
ABSTRACT In this paper it is shown how a triangular product of Householder reflections can be updated with an arbitrary elementary orthogonal transformation. The amount of work required is 5/2n 2 multiplications for absorbing an arbitrary... more
ABSTRACT In this paper it is shown how a triangular product of Householder reflections can be updated with an arbitrary elementary orthogonal transformation. The amount of work required is 5/2n 2 multiplications for absorbing an arbitrary reflection and 3n 2 multiplications for absorbing a plane rotation on subsequent indices.