Search results for "Filament"
showing 10 items of 405 documents
Submicrometer-Sized Roughness Suppresses Bacteria Adhesion.
2020
Biofilm formation is most commonly combatted with antibiotics or biocides. However, proven toxicity and increasing resistance of bacteria increase the need for alternative strategies to prevent adhesion of bacteria to surfaces. Chemical modification of the surfaces by tethering of functional polymer brushes or films provides a route toward antifouling coatings. Furthermore, nanorough or superhydrophobic surfaces can delay biofilm formation. Here we show that submicrometer-sized roughness can outweigh surface chemistry by testing the adhesion of E. coli to surfaces of different topography and wettability over long exposure times (>7 days). Gram-negative and positive bacterial strains are tes…
Filamentation-induced spectral broadening and pulse shortening of infrared pulses in Tellurite glass
2016
Abstract Filamentation of infrared femtosecond pulses in Tellurite glass is reported, leading to the generation of a supercontinuum generation spanning from the visible up to 4 μm. The angular distribution of the supercontinuum shows clear evidence of conical waves generation, in particular, in the visible region. Moreover, taking advantage of the spatio-temporal self-focusing effect occurring in the Tellurite glass, a twofold pulse shortening is demonstrated. Tellurite glass appears as a very convenient, versatile and promising medium for femtosecond nonlinear optics in the infrared region.
Evaluation of continuous filament mat influence on the bending behaviour of GFRP pultruded material via Electronic Speckle Pattern Interferometry
2017
Abstract Pultrusion is a process allowing the production of unidirectional (roving) fibre-reinforced polymer (FRP) structural elements with constant cross section. Recently, also civil engineers focused their attention on pultruded composite materials as alternative to traditional ones (e.g., concrete, steel). Furthermore, to improve the transverse strength and stiffness with respect to the fibres direction, continuous filament mat (CFM) is often placed within the stacking sequence. The CFM influence on the global mechanical behaviour is not considered by appropriate actual international standards. In this paper, the influence of the CFM layers on the mechanical behaviour of glass fibres pu…
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…
Cytochalasin B selectively releases ovalbumin mRNA precursors but not the mature ovalbumin mRNA from hen oviduct nuclear matrix
1987
Hen oviduct nuclear matrix-bound mature ovalbumin mRNA is released from the matrix in the presence of ATP, while the ovalbumin mRNA precursors remain bound to this structure. Detachment of the mature mRNA from the matrix by ATP as well as ATP-dependent efflux of mRNA from isolated nuclei were found to be inhibited by cytochalasin B. On the other hand, in the absence of ATP, cytochalasin B exclusively caused the release (and nucleocytoplasmic efflux) of the ovalbumin messenger precursors, but not of the mature mRNA. After cytochalasin B treatment, actin could be detected in the matrix supernatant. Phalloidin which stabilizes actin filaments did not cause RNA liberation in the absence of ATP,…
Patterns of Expression and Organization of Cytokeratin Intermediate Filaments
1985
Cytokeratins are a large multigene family comprising two polypeptide types, i.e. acidic (type I) and basic (type II) ones, which are distinguished on the basis of immunological, peptide mapping, mRNA hybridization, and primary amino acid sequence data. The acidic (type I) cytokeratins can be subdivided into at least two different subtypes on the basis of their carboxy-terminal sequences. Considerable interspecies conservation of sequences exists, even extending to the 3'-non-coding mRNA regions. Different pairs of type I and II cytokeratins show different resistance to dissociation in urea. Sequence differences of the type I cytokeratins containing functional domains may be an explanation o…
Fungal Biofilms as a Valuable Target for the Discovery of Natural Products That Cope with the Resistance of Medically Important Fungi—Latest Findings
2021
The development of new antifungal agents that target biofilms is an urgent need. Natural products, mainly from the plant kingdom, represent an invaluable source of these entities. The present review provides an update (2017–May 2021) on the available information on essential oils, propolis, extracts from plants, algae, lichens and microorganisms, compounds from different natural sources and nanosystems containing natural products with the capacity to in vitro or in vivo modulate fungal biofilms. The search yielded 42 articles; seven involved essential oils, two Brazilian propolis, six plant extracts and one of each, extracts from lichens and algae/cyanobacteria. Twenty articles deal with th…
Abnormal expansion of segmented filamentous bacteria in the gut
2011
Human intestinal microbiota create a complex polymicrobial ecology characterized by high population density, wide diversity, and complexity of interactions. Any imbalance of this complex intestinal microbiome, both qualitative and quantitative, might have serious health consequences including an increase in the number and/or alteration in the type of bacteria in the upper gastrointestinal tract, which is referred to as small intestinal bacterial overgrowth (SIBO) syndrome. SIBO is frequently found in persons fulfilling criteria for irritable bowel syndrome (IBS), and the large overlapping of symptoms of these two pathological conditions led some authors to believe that IBS is secondary to S…
Characterization of the Differential Pathogenicity of Candida auris in a Galleria mellonella Infection Model
2021
ABSTRACT Candida auris is an emergent multidrug-resistant fungal pathogen considered a severe global threat due to its capacity to cause nosocomial outbreaks and deep-seated infections with high transmissibility and mortality. However, evidence on its pathogenicity and the complex host-pathogen interactions is still limited. This study used the in vivo invertebrate model in Galleria mellonella to assess its virulence, exploring the mortality kinetics, melanization response, and morphological changes after fungal infection compared to Candida albicans and Candida parapsilosis, with known high and low pathogenicity, respectively. All C. auris isolates presented less virulence than C. albicans…
Immunogenicity and reactogenicity of a bicomponent and a tricomponent acellular pertussis-diphtheria-tetanus (DTaP) vaccine in primary immunization a…
1996
Abstract Objectives: To compare the immunogenicities and reactogenicities of bicomponent (B) (pertussis toxoid, filamentous hemagglutinin) and tricomponent (T) (pertussis toxoid, filamentous hemagglutinin, pertactin) acellular pertussis vaccines when coadministered with diphtheria and tetanus toxoids in primary (3, 4, and 5 mo) and booster (15–19 mo) vaccinations. Design and Methods: A randomized, double-blind study involving 175 children aged 12 to 18 weeks. Reactogenicity was based on diary cards, immunogenicity assessed by ELISA measurements of serum IgG antibodies. Results: There were no clinically relevant differences in local (B = 34.5; T=31.3%) and general (B = 43.9; T=41.8%) reactog…