Search results for "layer"
showing 10 items of 2667 documents
Buildup of Ultrathin Multilayer Films by a Self-Assembly Process: II. Consecutive Adsorption of Anionic and Cationic Bipolar Amphiphiles and Polyelec…
1991
We have recently reported on the consecutive physisorption of anionic and cationic bipolar amphiphiles onto charged surfaces, adsorbed out of aqueous solutions [1]. Here, we extend our previous concept to multipolar compounds such as polyelectrolytes. In contrast to the bipolar amphiphile system, it is not necessary to separate single charges by a rigid unit, when the polyelectrolyte is adsorbed from sufficiently concentrated solutions. In this case the physisorbed layer does not bind with all ionic groups to the surface and exposes free ionic groups at the new film/solution interface. Therefore a polyelectrolyte layer can replace a layer of bipolar amphiphiles in the consecutive buildup of…
Mono- and Multi-Layers
2006
Thin films incorporating or consisting of calixarenes have been widely investigated. The capacity of such films to adsorb both ions and neutral species has engendered particular interest in their use in sensor devices. Semiconductors, non-linear optical and pyroelectric materials or switchable systems for data storage are further examples of their potential use [1]. Both monoand multi-layer films can be formed from calixarenes and resorcarenes, using a variety of techniques. This chapter deals with the fundamental basis of calixarene thin film applications, including film formation and characterisation as well as studies of selectivity in small molecule interactions. Real and potential appl…
Layer-by-Layer Adsorption: The Solid/Liquid-Interface as a Template for the Controlled Growth of Well-Defined Nanostructures of Polyelectrolytes, Pro…
1994
This report describes the construction of ultrathin films whose structure can be tailored on the molecular scale. The resulting supramolecular film architectures may include functional biological macromolecules such as proteins or polynucleotides. The average distances of two functional layers can be adjusted on the nanometer scale (from less than lnm to several tens of nanometers), with a precision of approximately 0.1 nm. This control is achieved by varying the number and the thickness of the polyelectrolyte interlayers and requires the capability of steering each adsorption step with high accuracy. A crucial factor is the fabrication and manipulation of the film surface at each adsorptio…
<title>Large-scale computer simulations of metal/oxide interfaces with defects</title>
2003
Ab initio slab simulations have been performed for silver adhesion to the perfect and defective MgO(001) surfaces. For 1/4 Ag monolayer (ML) coverage of perfect substrate, we observe small silver adhesion energies over both O2- and Mg2+ ions on a regular MgO(001) substrate (0.23 and 0.22 eV per Ag atom, respectively), with negligible interfacial charge transfer towards metal atoms. For larger Ag coverages (beginning with 1/2 ML), silver adsorption over regular O2- ions is much more favorable. We demonstrate that point surface defects on a magnesia surface increase markedly the metal adhesion energy and cause a redistribution of the electron density across the interface. The results for elec…
Dosage individualization of erythropoietin using a profile-dependent support vector regression
2003
The external administration of recombinant human erythropoietin is the chosen treatment for those patients with secondary anemia due to chronic renal failure in periodic hemodialysis. The objective of this paper is to carry out an individualized prediction of the EPO dosage to be administered to those patients. The high cost of this medication, its side-effects and the phenomenon of potential resistance which some individuals suffer all justify the need for a model which is capable of optimizing dosage individualization. A group of 110 patients and several patient factors were used to develop the models. The support vector regressor (SVR) is benchmarked with the classical multilayer percept…
Isocortical Pathology in Type C Niemann-Pick Disease
1983
A case of Niemann-Pick disease was examined with Golgi preparations and a transparent Golgi impregnation counterstained for intraneuronal pigment deposits. There was a specific type of storage of unmetabolized substrate restricted to certain nerve cell types. The most conspicuous changes in the isocortex were: 1) dilated axonal segments in layer IIIab pyramidal cells filled with storage material; the volume of these axonal expansions often exceeded that of the soma; 2) distension of layer IIIc, layer V, and layer VIa pyramidal cell perikarya with storage material; 3) new formation, elongation, and vertical orientation of basal dendrites in layer V pyramidal cells; 4) well-preserved pyramida…
Localized crusted scabies in the acquired immunodeficiency syndrome
1992
Summary Crusted scabies (CrS) is an uncommon occurrence among patients with AIDS. Indeed to date only five cases have been described, all with widespread lesions. A case of localized CrS appearing as a yellowish and crusted plaque on the second right toe is reported in a woman with AIDS. Scraping off the verrucous surface, as well as punch-biopsy revealed many mites within the horny layer. The infestation is related to the cutaneous immune response and thus CrS should be considered an opportunistic infestation in AIDS. The importance of the early diagnosis of CrS in order to prevent disseminated lesions and involvement of other health-care workers is underlined.
Influence of the structural components of artificial turf systems on impact attenuation in amateur football players
2019
AbstractThe purpose of this research was to evaluate the influence of the structural components of different 3rd generation artificial turf football field systems on the biomechanical response of impact attenuation in amateur football players. A total of 12 amateur football players (24.3 ± 3.7 years, 73.5 ± 5.5 kg, 178.3 ± 4.1 cm and 13.7 ± 4.3 years of sport experience) were evaluated on three third generation artificial turf systems (ATS) with different structural components. ATS were composed of asphalt sub-base and 45 mm of fibre height with (ATS1) and without (ATS2) elastic layer or compacted granular sub-base, 60 mm of fibre height without elastic layer (ATS3). Two triaxial accelerome…
Alzheimer's disease: amyloid plaques in the cerebellum
1989
Two specific silver-staining methods demonstrating either extracellular amyloid and/or precursors of amyloid or intraneuronal neurofibrillary changes were used to examine cerebellar pathology in cases of presenile and senile dementia of the Alzheimer type, cases of Down's syndrome, and non-demented controls. The sensitivity of the techniques permitted visualization of large numbers of amyloid deposits in the cerebellar cortex of demented individuals. Similarly large numbers of amyloid deposits were not found in the cerebella of non-demented individuals. Neurofibrillary changes were absent. The majority of amyloid plaques occurred in the molecular layer. Quite a number of these displayed lar…
Pharmacokinetics of triamterene after i.v. administration to man: determination of bioavailability.
1983
With a new formulation, which made intravenous infusion of triamterene (TA) possible, plasma levels and urinary excretion rates of TA and its main metabolite (OH-TA-ester) were measured in a randomized, cross-over trial in 6 healthy volunteers given triamterene 10 mg i.v. and 50 mg p.o. TA and OH-TA-ester were determined by densitometric measurement of native fluorescence after thin layer chromatography. Distribution volumes of the central compartment of TA and OH-TA-ester were 1.49 l/kg and 0.11 l/kg, respectively. Terminal half-lives were 255 min for TA and 188 min for OH-TA-ester after i.v. administration. For TA total plasma clearance was 4.5 l/min and renal plasma clearance 0.22 l/kg. …