Search results for "Protein filament"
showing 10 items of 46 documents
Vimentin and desmin of a cartilaginous fish, the shark Scyliorhinus stellaris: Sequence, expression patterns and in vitro assembly
2002
In the shark Scyliorhinus stellaris we have biochemically identified and cDNA-cloned orthologs of human vimentin and desmin, SstV and SstD, as deduced from immunoblotting and sequence alignment with teleost, frog and human vimentin and desmin, respectively. This allowed us to further clarify the relationship of previously identified lower vertebrate intermediate filament proteins to mammalian vimentin and desmin. Immunofluorescence microscopy with antibodies H5 and VIM13.2 showed vimentin expression in shark eye and brain and absence in epithelia, which resembles the situation in higher vertebrates. In addition, SstV is expressed in many mesenchymal cell types which corresponds to the case …
UME6, a Novel Filament-specific Regulator ofCandida albicansHyphal Extension and Virulence
2008
The specific ability of the major human fungal pathogen Candida albicans, as well as many other pathogenic fungi, to extend initial short filaments (germ tubes) into elongated hyphal filaments is important for a variety of virulence-related processes. However, the molecular mechanisms that control hyphal extension have remained poorly understood for many years. We report the identification of a novel C. albicans transcriptional regulator, UME6, which is induced in response to multiple host environmental cues and is specifically important for hyphal extension. Although capable of forming germ tubes, the ume6Δ/ume6Δ mutant exhibits a clear defect in hyphal extension both in vitro and during i…
Filament-induced visible-to-mid-IR supercontinuum in a ZnSe crystal: Towards multi-octave supercontinuum absorption spectroscopy
2016
Abstract We report on the generation of multiple-octave supercontinuum laser source spanning from 0.5 μm to 11 μm induced by multi-filamentation in a ZnSe crystal. The generated supercontinuum is both spatially and spectrally characterized. It is then exploited in a proof-of-principle experiment for methane spectroscopy measurements by means of the supercontinuum absorption spectroscopy technique. The entire absorption spectrum is successfully recorded within the whole spectral bandwidth of the supercontinuum. Experimental results are in fairly good agreement with the HITRAN database, confirming the reliability and stability over several hours of the generated supercontinuum.
Influence of oxygen ion elementary diffusion jumps on the electron current through the conductive filament in yttria stabilized zirconia nanometer-si…
2021
Abstract The structure of the electron current through an individual filament of a nanometer-sized virtual memristor consisting of a contact of a conductive atomic force microscope probe to an yttria stabilized zirconia (YSZ) thin film deposited on a conductive substrate is investigated. Usually, such investigation is performed by the analysis of the waveform of this current with the aim to extract the random telegraph noise (RTN). Here, we suggest a new indirect method, which is based on the measurement of the spectrum of the low-frequency flicker noise in this current without extracting the RTN, taking into account the geometrical parameters of the filament. We propose that the flicker no…
Determination of lifetime probabilities of carbon fibre composite plates and pressure vessels for hydrogen storage
2011
International audience; It is shown that an analogy can be made between the failure of unidirectional carbon fibre reinforced epoxy plates and filament wound carbon fibre composite pressure vessels and that their strengths and failure probabilities can be determined. Fibres in filament wound composite structures are placed on geodesic paths around the mandrel, which becomes the liner; so that when the structure is pressurised the fibres are only subjected to tensile forces, as in a unidirectional composite. Multiscale modelling reveals that composite failure is controlled by fibre breakage and that clustering of fibre breaks determines ultimate reliability of the structure. Time dependent r…
Visual indicator for the detection of end-of-life criterion for composite high pressure vessels for hydrogen storage
2012
International audience; A model to predict the accumulation of fibre breaks in advanced composites, that takes into account all physical phenomena implicated in fibre failure (i.e. the random nature, stress transfer due to breaks, fibre debonding and viscosity of the matrix) shows clearly that the failure of a unidirectional composite structure results in the formation of random fibre breaks which at higher loads coalesce into clusters of broken fibres. This stage of development is followed almost immediately by failure. This has direct application to filament wound pressure vessels of the type used to store hydrogen under high pressure. A novel, cost effective, method of revealing developi…
Deformation of flexible ferromagnetic filaments under a rotating magnetic field
2019
Research on magnetic particles dispersed in a fluid medium, actuated by a rotating magnetic field, is becoming increasingly active for both lab-on-chip and bio-sensing applications. In this study, we experimentally investigate the behaviour of ferromagnetic filaments in a rotating field. Filaments are synthesized by linking micron-sized ferromagnetic particles with DNA strands. The experiments were conducted under different magnetic field strengths, frequencies and filament sizes, and deformation of the filaments was registered via microscope and camera. The results obtained showed that the body deformation is larger for longer filaments and higher frequencies and lower for larger magnetic …
Design and analysis of filament power supply method for increasing life time of thermal emission tubes
2017
This paper has reviewed power supply methods for thermal electron tubes and proposes a method for purpose of increasing its lifetime, with reducing complexity of circuit and, improvement in power efficiency. In this work, the filament is operated with a decreased voltage level while maintaining the output anode power at the same level as required for the filament's operation at nominal voltage. The supply circuit is designed to avoid the reduction of filament voltage below a minimum level. A power converter made of thyristors and rectification diodes is designed to supply the filament voltage. Converter is carefully monitored and controlled by an algorithm embedded in a contemporary Digital…
Fractal-related assembly of the axial filament in the demosponge Suberites domuncula: relevance to biomineralization and the formation of biogenic si…
2007
Abstract The siliceous spicules of sponges (Porifera) show great variations of sizes, shapes and forms; they constitute the chief supporting framework of these animals; these skeletal elements are synthesized enzymatically by silicatein. Each sponge species synthesizes at least two silicateins, which are termed − α and − β . In the present study, using the demosponge Suberites domuncula , we studied if the silicateins of the axial filament contribute to the shape formation of the spicules. For these experiments native silicateins have been isolated by a new Tris/glycerol extraction procedure. Silicateins isolated by this procedure are monomeric (24 kDa), but readily form dimers through non-…
Mechanism of Oligomerisation of Cyclase-associated Protein from Dictyostelium discoideum in Solution
2006
Abstract Cyclase-associated protein (CAP) is a highly conserved modular protein implicated in the regulation of actin filament dynamics and a variety of developmental and morphological processes. The protein exists as a high molecular weight complex in cell extracts and purified protein possesses a high tendency to aggregate, a major obstacle for crystallisation. Using a mutagenesis approach, we show that two structural features underlie the mechanism of oligomerisation in Dictyostelium discoideum CAP. Positively charged clusters on the surface of the N-terminal helix-barrel domain are involved in inter-molecular interactions with the N or C-terminal domains. Abolishing these interactions m…