Search results for "layer"

Surface effects on spinodal decomposition in binary mixtures and the interplay with wetting phenomena.

1994

The phase separation of binary mixtures in a semi-infinite geometry is investigated both by a phenomenological theory and by numerical calculations using a discrete equivalent of the descriptive equations. In the framework of ``model B'' (which describes solid binary mixtures), attention is paid to a proper treatment of the boundary conditions at the free surfaces. We confine ourselves to short-range surface forces and consider parameter values that correspond to both nonwet and wet surfaces in thermal equilibrium. During the initial stages of spinodal decomposition, after a quench from considering an initial condition that corresponds to a completely random concentration distribution, one …

Dust mobilization and transport in the northern Sahara during SAMUM 2006 – a meteorological overview

2009

The SAMUM field campaign in southern Morocco in May/June 2006 provides valuable data to study the emission, and the horizontal and vertical transports of mineral dust in the Northern Sahara. Radiosonde and lidar observations show differential advection of air masses with different characteristics during stable nighttime conditions and up to 5-km deep vertical mixing in the strongly convective boundary layer during the day. Lagrangian and synoptic analyses of selected dust periods point to a topographic channel from western Tunisia to central Algeria as a dust source region. Significant emission events are related to cold surges from the Mediterranean in association with eastward passing upp…

Corrigendum to “Multi-layer canard cycles and translated power functions” [J. Differential Equations 244 (2008) 1329–1358]

2008

Shear sense indicators in striped bedding-veins

2000

Striped bedding-veins are veins that lie subparallel to bedding and have an internal layering or lineation at a small angle to the veins’ long axis. They form during bedding-parallel slip and can be used as shear sense indicators. Solid inclusion trails produce the visible internal layering or lineation and track the opening direction of the veins. Elongate quartz crystals however can be oriented at an angle of up to 80° to the opening direction, are non-tracking, and contain almost no information on the shear sense. The striped bedding-veins can be separated into three types according to the geometry of their internal segmentation. Veins of type B opened parallel to jogs oriented at a low …

In favour of layered feet: A response to Golston

2021

In this response we argue that the factorial typology predicted in Martínez-Paricio & Kager (2015), which representationally relies on the existence of internally layered ternary feet, is complete and accurate. We demonstrate it does not suffer from the problematic cases of overgeneration pointed out by Golston (this issue). Additionally, we corroborate the idea that the internally layered ternary foot is a metrical representation that is typologically warranted for stress phenomena as well as for segmental and tonal metrically conditioned distributions. We suggest that Golston's claim that "no stress system requires internally layered ternary feet" appears to be too strong and is not empir…

Interactions of liposomes and hydrophobically-modified poly-(N-isopropylacrylamides): an attempt to model the cytoskeleton

1993

The interactions of small unilamellar vesicles (SUV) and water-soluble copolymers were studied by fluorescence spectroscopy, differential scanning calorimetry (DSC) and quasi-elastic light scattering (QELS). The anchoring onto liposomal bilayer membranes of copolymers of N-isopropylacrylamide, N-(2-(1-naphthyl)ethyl)-N-n-octadecylacrylamide and or N-[4-(1-pyrenyl)butyl]-N-n-octadecylacrylamide (0.5 mol% of the octadecylacrylamide comonomer) was monitored by non-radiative energy transfer between excited naphthalene and pyrene. The anchoring process occurred on zwitterionic lecithin liposomes and on negatively charged phosphatidic acid liposomes, whether the bilayer was in the crystalline or …

Spectrophotometric evidence for the solubilization site of betalain pigments in membrane biomimetic systems.

2007

The solubilization site of two betalain pigments, namely, betanin and indicaxantin, into l-alpha-dipalmitoyl-phosphatidylcholine (DPPC) and dimyristoylphosphatidylcholine (DMPC) vesicles was investigated by a spectrophotometric study. Pigment absorbance was monitored by varying phospholipid concentration, at a constant temperature that was varied in a range including the main phase transition temperature (Tm) of the relevant phospholipid bilayer. Maximum betanin absorption increased with the increase of DPPC concentration within the entire temperature range, reaching a plateau. The binding constant (Kb) of the pigment, calculated according to a pseudo-two-phase model, varied with the temper…

Quantification of the Raf-C1 Interaction With Solid-Supported Bilayers

2002

By use of the quartz crystal microbalance technique, the interaction of the Raf-Ras binding domain (RafRBD) and the cysteine-rich domain Raf-C1 with lipids was quantified by using solid-supported bilayers immobilized on gold electrodes deposited on 5 MHz quartz plates. Solid-supported lipid bilayers were composed of an initial octanethiol monolayer chemisorbed on gold and a physisorbed phospholipid monolayer varying in its lipid composition as the outermost layer. The integrity of bilayer preparation was monitored by impedance spectroscopy. For binding experiments, a protein construct comprising the RafRBD and Raf-C1 linked to the maltose binding protein and a His tag, termed MBP-Raf-C1, wa…

In situ synthesis of lipopeptides as versatile receptors for the specific binding of nanoparticles and liposomes to solid-supported membranes.

2008

A detailed study of the in situ coupling of small peptides such as CGGH6 (H6) and CGWK8 (K8) to maleimide functionalized phospholipid bilayers is presented. Individually addressable microstructured membranes are employed to unequivocally probe the conjugation. The in situ coupling of peptides via a terminal cysteine moiety to maleimide functionalized phospholipids is shown to be a convenient and versatile way to selectively fabricate peptide-modified phospholipid bilayers serving as specific receptor platforms for functionalized vesicles and nanoparticles. Specific binding of functional vesicles to the peptide-modified bilayers is achieved by either histidine complexation with Ni-NTA-DOGS c…

Reaction of melatonin with lipoperoxyl radicals in phospholipid bilayers.

1997

Melatonin, at 5 to 500 microM was incorporated in unilamellar soybean phosphatidylcholine (PC) liposomes, the peroxidation of which was induced by 2,2'-azobis (2-amidinopropane-hydrochloride) (AAPH), and measured as production of conjugated diene lipid hydroperoxides. Concentration as low as 5 and 10 microM were poorly effective in reducing lipid peroxidation. Melatonin at 30 to 500 microM caused short inhibition periods, increasing with, but not linearly related to concentration, with a concurrent net decrease of the propagation rate. The time course of melatonin oxidation, measured as loss of fluorescence, was studied during the AAPH-stimulated peroxidation of soybean PC liposomes, or whe…