Bockmuhl D.,Rhine-Waal University of Applied Sciences
Tenside, Surfactants, Detergents | Year: 2012
A considerable number of biosurfactants have been investigated for their antibacterial, antifungal or antiviral activity that is mostly based on the ability to destroy microbial cell membranes. In addition, some of them are also able to inhibit the adhesion of microorganisms to surfaces and tissues. Although these antimicrobial properties can be generally explained by a strong detergency effect, there are further mechanisms, such as the interaction with membrane phospholipids or the alteration of the electrical conductance of membranes, resulting in the damage of microbial cells. Typically, antimicrobially active biosurfactants are glycolipids (e.g. rhamnolipids) or cyclic lipopeptides (e.g. Polymyxin). Since most of these substances were not available in larger quantities in the past, their potential applications in cleaners and cosmetics was not studied intensely, however, their versatility and the possibility of combining different properties, such as cleaning and antimicrobial effects, suggest a further consideration of biosurfactants even for mass-market products. © Carl Hanser Publisher, Munich.
Bockmuhl D.,Rhine-Waal University of Applied Sciences
Hygiene + Medizin | Year: 2011
The laundering of textiles as one major aspect of home hygiene is considered important by the consumer not only because of its role in the prevention of infections, but mostly due to esthetic reasons. In this context, the understanding of how microorganisms colonise fabrics and how the washing process can eliminate those contaminations, is a crucial step to prevent adverse secondary microbiological effects, such as malodour or infection risks. However, the factors influencing both microbial colonisation and subsequent removal during laundering are complex, substantiating the necessity for test methods that allow a realistic evaluation of the antimicrobial efficacy of the washing process.
Fahmi A.,Rhine-Waal University of Applied Sciences
Advances in Polymer Science | Year: 2014
Nanofabrication via self-assembled hybrid building blocks into welldefined structures is a powerful tool for engineering functional materials with designed properties. This review demonstrates different concepts for fabrication of one-dimensional (1D) nanostructures based on hybrid materials via directed self-assembly. The concepts describe how different types of self-assembled organic phases drive the unidirectional assembly of the inorganic moieties. The organic matrices are used to control the size and size distribution of the generated inorganic nanoparticles. Formation of the 1D structures is dependent on many parameters, such as nature of chemical composition of the hybrid organic–inorganic materials, the pH of the wet chemistry medium and the types of interactions at the interface that drive the structure formation. The collective properties of the designed 1D structures are induced by means of the degree of anisotropy and the alignment of different types of inorganic nanoparticles within the organic matrices. This cost-effective approach could potentially be extended to fabricate varieties of hybrid low dimensional nanostructures possessing unique collective electronic and optical properties, leading to a wide range of applications such as catalysis, bionanotechnology, nanoelectronics, photonics and optoelectronics. © Springer-Verlag Berlin Heidelberg 2014.
Shirtcliffe N.J.,Rhine-Waal University of Applied Sciences |
Roach P.,Keele University
Methods in Molecular Biology | Year: 2013
Fouling of surfaces is often problematic in micro fluidic devices, particularly when using protein or enzymatic solutions. Various coating methods have been investigated to reduce the tendency for protein molecules to adsorb, mostly relying on hydrophobic surface chemistry or the antifouling ability of polyethylene glycol. Here we present the potential use of superhydrophobic surfaces to not only reduce the amount of surface contamination but also to induce self-cleaning under flow conditions. The methodology is presented in order to prepare superhydrophobic surface coatings having micro-And nanoscale feature dimensions, as well as a step-by-step guide to quantify adsorbed protein down to nanogram levels. The fabrication of these surfaces as coatings via silica sol-gel and copper nano-hair growth is presented, which can be applied within micro fluidic devices manufactured from various materials © Springer Science+Business Media, LLC 2013.
Wild-Wall N.,Rhine-Waal University of Applied Sciences |
Falkenstein M.,Leibniz Research Center for Working Environment and Human Factors o |
Gajewski P.D.,Leibniz Research Center for Working Environment and Human Factors o
Neural Plasticity | Year: 2012
This study aimed to elucidate the underlying neural sources of near transfer after a multidomain cognitive training in older participants in a visual search task. Participants were randomly assigned to a social control, a no-contact control and a training group, receiving a 4-month paper-pencil and PC-based trainer guided cognitive intervention. All participants were tested in a before and after session with a conjunction visual search task. Performance and event-related potentials (ERPs) suggest that the cognitive training improved feature processing of the stimuli which was expressed in an increased rate of target detection compared to the control groups. This was paralleled by enhanced amplitudes of the frontal P2 in the ERP and by higher activation in lingual and parahippocampal brain areas which are discussed to support visual feature processing. Enhanced N1 and N2 potentials in the ERP for nontarget stimuli after cognitive training additionally suggest improved attention and subsequent processing of arrays which were not immediately recognized as targets. Possible test repetition effects were confined to processes of stimulus categorisation as suggested by the P3b potential. The results show neurocognitive plasticity in aging after a broad cognitive training and allow pinpointing the functional loci of effects induced by cognitive training. © 2012 Nele Wild-Wall et al.