Search results for "ARTICLES"

A Raft-derived, Pak1-regulated Entry Participates in α2β1 Integrin-dependent Sorting to Caveosomes

2008

We have previously shown that a human picornavirus echovirus 1 (EV1) is transported to caveosomes during 2 h together with its receptor alpha2beta1 integrin. Here, we show that the majority of early uptake does not occur through caveolae. alpha2beta1 integrin, clustered by antibodies or by EV1 binding, is initially internalized from lipid rafts into tubulovesicular structures. These vesicles accumulate fluid-phase markers but do not initially colocalize with caveolin-1 or internalized simian virus 40 (SV40). Furthermore, the internalized endosomes do not contain glycosylphosphatidylinositol (GPI)-anchored proteins or flotillin 1, suggesting that clustered alpha2beta1 integrin does not enter…

Interactions of silica nanoparticles with lung epithelial cells and the association to flotillins

2012

Amorphous silica nanoparticles (aSNPs) gain increasing popularity for industrial and therapeutic claims. The lung with its surface area of 100-140 m(2) displays an ideal target for therapeutic approaches, but it represents also a serious area of attack for harmful nanomaterials. The exact nature of the cytotoxic effects of NPs is still unknown. Furthermore, cellular pathways and the destiny of internalized NPs are still poorly understood. Therefore, we examined the cytotoxicity (MTS, LDH) and inflammatory responses (IL-8) for different-sized aSNPs (30, 70, 300 nm) on our lung epithelial cells line NCI H441 and endothelial cell line ISO-HAS-1. Additionally, colocalization studies have been c…

Tracing European Founder Lineages in the Near Eastern mtDNA Pool

2000

Founder analysis is a method for analysis of nonrecombining DNA sequence data, with the aim of identification and dating of migrations into new territory. The method picks out founder sequence types in potential source populations and dates lineage clusters deriving from them in the settlement zone of interest. Here, using mtDNA, we apply the approach to the colonization of Europe, to estimate the proportion of modern lineages whose ancestors arrived during each major phase of settlement. To estimate the Palaeolithic and Neolithic contributions to European mtDNA diversity more accurately than was previously achievable, we have now extended the Near Eastern, European, and northern-Caucasus d…

Coelomocytes and post-traumatic response in the common sea star Asterias rubens.

2008

Coelomocytes are recognized as the main cellular component of the echinoderm immune system. They are the first line of defense and their number and type can vary dramatically during infections or following injury. Sea stars have been used as a model system to study the regeneration process after autotomy or predation. In the present study we examined the cellular and biochemical responses of coelomocytes from the European sea star Asterias rubens to traumatic stress using immunochemical and biochemical approaches. In terms of trauma and post-traumatic stress period, here we consider the experimental arm amputation and the repair phase involved in the first 24 hours post-amputation, which mi…

Functional implications of the staminal lever mechanism in Salvia cyclostegia (Lamiaceae)

2011

Flower morphology and inflorescence architecture affect pollinator foraging behaviour and thereby influence the process of pollination and the reproductive success of plants. This study explored possible ecological functions of the lever-like stamens and the floral design in Salvia cyclostegia.Flower construction was experimentally manipulated by removing either the lower lever arms or the upper fertile thecae of the two stamens from a flower. The two types of manipulated individuals were intermixed with the control ones and randomly distributed in the population.Removing the sterile lower lever arms significantly reduced handling time per flower of the main pollinator, Bombus personatus. I…

Thermal photons from fluctuating initial conditions

2011

Event-by-event fluctuations of initial QCD-matter density produced in heavy-ion collisions at RHIC enhance the production of thermal photons significantly in the region $2 \le p_T \le 4$ GeV/$c$ compared to a smooth initial-state averaged profile in the ideal hydrodynamic calculation. This enhancement is a an early time effect due to the presence of hotspots or over-dense regions in the fluctuating initial state. The effect of fluctuations is found to be stronger in peripheral than in central collisions.

Thermal Evolution of Titania Nanostructured Powders Obtained from Reverse Micelle Method

2012

Micro/nanostructured thin films : synthesis by ALD of composites associating TiO2 inverse opals and gold nanoparticles for photocatalysis applications

2021

The aim of this work was to improve the photocatalytic properties of titanium dioxide (TiO2) thin films, a semiconductor that is widely used for photocatalysis applications, particularly for the treatment of polluted water. For this purpose, two complementary approaches were studied: increasing the surface area available for photocalatytic reactions and coupling between TiO2 and gold nanoparticles.. For the first approach, TiO2 thin films with different morphological structures were fabricated by Atomic Layer Deposition: dense and porous flat films, and inverse opals films.In order to evaluate photocatalytic activity of the different films, the degradation of methylene blue in aqueous solut…

Hydrothermal Synthesis of Ionic Liquid [Bmim]OH-Modified TiO2 Nanoparticles with Enhanced Photocatalytic Activity under Visible Light

2010

TiO(2) nanocomposites modified with the ionic liquid [Bmim]OH are synthesized by a hydrothermal procedure. X-ray diffraction, Zeta-potential measurement, TEM, thermogravimetric analysis, photoluminescence, UV/Vis, FTIR, and X-ray photoelectron spectroscopy are used to characterize the TiO(2) nanocomposites. The TiO(2) nanocomposites consist of pure anatase particles of about 10 nm. The modification of [Bmim]OH on the surface of the TiO(2) particles extends the TiO(2) absorption edge to the visible-light region. The electrochemical redox potentials indicated that the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of [Bmim]OH match well with the valen…

Synthesis of Mesoporous Supraparticles on Superamphiphobic Surfaces

2015

A method for mesoporous supraparticle synthesis on superamphiphobic surfaces is designed. Therefore, supraparticles assembled with nanoparticles are synthesized by the evaporation of nanoparticle dispersion drops on the superamphiphobic surface. For synthesis, no further purification is required and no organic solvents are wasted. Moreover, by changing the conditions such as drop size and concentration, supraparticles of different sizes, compositions, and architectures are fabricated.