530 research outputs found
Glycosylation pattern of brush border-associated glycoproteins in enterocyte-like cells: involvement of complex-type N-glycans in apical trafficking
We have previously reported that galectin-4, a tandem repeat-type galectin, regulates the raft-dependent delivery of glycoproteins to the apical brush border membrane of enterocyte-like HT-29 cells. N-Acetyllactosamine-containing glycans, known as galectin ligands, were found enriched in detergent-resistant membranes. Here, we analyzed the potential contribution of N-and/ or O-glycans in this mechanism. Structural studies were carried out on the brush border membrane-enriched fraction using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and nano-ESI-QTOF-MS/MS. The pattern of N-glycans was very heterogeneous, with the presence of high mannose- and hybrid-type glycans as well as a multitude of complex-type glycans. In contrast, the pattern of O-glycans was very simple with the presence of two major core type 1 O-glycans, sialylated and bisialylated T-antigen structures {[}Neu5Ac alpha 2-3Gal beta 1-3GalNAc-ol and Neu5Ac alpha 2-3Gal beta 1 -3(Neu5Ac alpha 2-6)GalNAc-ol]. Thus, N-glycans rather than O-glycans contain the N-acetyllactosamine recognition signals for the lipid raft-based galectin-4-dependent apical delivery. In the presence of 1-deoxymannojirimycin, a drug which inhibits the generation of hybrid-type or complex type N-glycans, the extensively O-glycosylated mucin-like MUC1 glycoprotein was not delivered to the apical brush border but accumulated inside the cells. Altogether, our data demonstrate the crucial role of complex N-glycans in the galectin-4-dependent delivery of glycoproteins to the apical brush border membrane of enterocytic HT-29 cells
Technical Evolution of Ceramic Tile Printing
[EN] Ceramic tile decorating techniques have evolved significantly in recent years. Digital inkjet printing technology has enabled digital systems to be used for the direct decoration of ceramic tiles, revolutionizing ceramic tile decoration and providing many advantages over traditional decoration techniques. It was the formulation of inks with soluble and vitrifiable stains that allowed inkjet printing technology to be introduced into ceramic tile decoration. The incorporation of milled inorganic pigments into the inks broadened the available color palette. However, the colloidal instability of these inks and the constraints of the printing heads themselves made it necessary to reduce pigment particle size, thus limiting color saturation and the color gamut. In order to increase color saturation and obtain a set of pigmented inks with colors more closely resembling CMYK colors, pigments with larger particle sizes need to be used. Indeed, other digital decorating techniques, such as xerography, allow larger particle sizes to be used, while also providing the advantages associated with digital decoration. However, the implementation of this technique for ceramic tile decoration requires the development of appropriate ceramic toners and adaptation of printing machines. This article reviews the technical evolution of ceramic tile printing and describes the development of a prototype, based on xerographic printing, that is able to print ceramic tiles directly and provides greater color intensity and a wider color gamut.40140756
Surface collective modes in the topological insulators BiSe and BiSbTeSe
We used low-energy, momentum-resolved inelastic electron scattering to study
surface collective modes of the three-dimensional topological insulators
BiSe and BiSbTeSe. Our goal was to
identify the "spin plasmon" predicted by Raghu and co-workers [S. Raghu, et
al., Phys. Rev. Lett. 104, 116401 (2010)]. Instead, we found that the primary
collective mode is a surface plasmon arising from the bulk, free carrers in
these materials. This excitation dominates the spectral weight in the bosonic
function of the surface, , at THz energy scales, and
is the most likely origin of a quasiparticle dispersion kink observed in
previous photoemission experiments. Our study suggests that the spin plasmon
may mix with this other surface mode, calling for a more nuanced understanding
of optical experiments in which the spin plasmon is reported to play a role.Comment: 5 pages, 4 figure
Medallero valenciano o sea catálogo de medallas referentes a personas, conmemoraciones, fiestas... y en general, sucesos de Valencia [Texto impreso]
Separata de : Archivo de Arte Valencian
High-dispersion spectroscopic monitoring of the Be/X-ray binary A0535+26/V725 Tau I: The long-term profile variability
We report on optical high-dispersion spectroscopic monitoring observations of
the Be/X-ray binary A0535+26/V725 Tau, carried out from November 2005 to March
2009. The main aim of these monitoring observations is to study spectral
variabilities in the Be disc, on both the short (a week or so) and long (more
than hundreds of days) timescales, by taking long-term frequent observations.
Our four-year spectroscopic observations indicate that the V/R ratio, i.e., the
relative intensity of the violet (V) peak to the red (R) one, of the
double-peaked H-alpha line profile varies with a period of 500 days. The H-beta
line profile also varies in phase with the H-alpha profile. With these
observations covering two full cycles of the V/R variability, we reconstruct
the 2-D structure of the Be disc by applying the Doppler tomography method to
the H-alpha and H-beta emission line profiles, using a rigidly rotating frame
with the V/R variability period. The resulting disc structure reveals
non-axisymmetric features, which can be explained by a one-armed perturbation
in the Be disc. It is the first time that an eccentric disc structure is
directly detected by using a method other than the interferometric one.Comment: (10 pages, 9 figures, accepted to MNRAS
Perpendicular magnetic anisotropy in chemically disordered FePd-FeV(100) alloy thin films
We find that the use of V(100) buffer layers on MgO(001) substrates for the epitaxy of FePd binary alloys yields to the formation at intermediate and high deposition temperatures of a FePd¿FeV mixed phase due to strong V diffusion accompanied by a loss of layer continuity and strong increase of its mosaic spread. Contrary to what is usually found in this kind of systems, these mixed phase structures exhibit perpendicular magnetic anisotropy (PMA) which is not correlated with the presence of chemical order, almost totally absent in all the fabricated structures, even at deposition temperatures where it is usually obtained with other buffer layers. Thus the observed PMA can be ascribed to the V interdiffusion and the formation of a FeV alloy, being the global sample saturation magnetization also reduced
Enhanced Thermal Conductivity of Free-Standing Double-Walled Carbon Nanotube Networks
Nanomaterials are driving advances in technology due to their oftentimes superior properties over bulk materials. In particular, their thermal properties become increasingly important as efficient heat dissipation is required to realize high-performance electronic devices, reduce energy consumption, and prevent thermal damage. One application where nanomaterials can play a crucial role is extreme ultraviolet (EUV) lithography, where pellicles that protect the photomask from particle contamination have to be transparent to EUV light, mechanically strong, and thermally conductive in order to withstand the heat associated with high-power EUV radiation. Free-standing carbon nanotube (CNT) films have emerged as candidates due to their high EUV transparency and ability to withstand heat. However, the thermal transport properties of these films are not well understood beyond bulk emissivity measurements. Here, we measure the thermal conductivity of free-standing CNT films using all-optical Raman thermometry at temperatures between 300 and 700 K. We find thermal conductivities up to 50 W m-1 K-1 for films composed of double-walled CNTs, which rises to 257 W m-1 K-1 when considering the CNT network alone. These values are remarkably high for randomly oriented CNT networks, roughly seven times that of single-walled CNT films. The enhanced thermal conduction is due to the additional wall, which likely gives rise to additional heat-carrying phonon modes and provides a certain resilience to defects. Our results demonstrate that free-standing double-walled CNT films efficiently dissipate heat, enhancing our understanding of these promising films and how they are suited to applications in EUV lithography.</p
Enhanced Thermal Conductivity of Free-Standing Double-Walled Carbon Nanotube Networks
Nanomaterials are driving advances in technology due to their oftentimes superior properties over bulk materials. In particular, their thermal properties become increasingly important as efficient heat dissipation is required to realize high-performance electronic devices, reduce energy consumption, and prevent thermal damage. One application where nanomaterials can play a crucial role is extreme ultraviolet (EUV) lithography, where pellicles that protect the photomask from particle contamination have to be transparent to EUV light, mechanically strong, and thermally conductive in order to withstand the heat associated with high-power EUV radiation. Free-standing carbon nanotube (CNT) films have emerged as candidates due to their high EUV transparency and ability to withstand heat. However, the thermal transport properties of these films are not well understood beyond bulk emissivity measurements. Here, we measure the thermal conductivity of free-standing CNT films using all-optical Raman thermometry at temperatures between 300 and 700 K. We find thermal conductivities up to 50 W m-1 K-1 for films composed of double-walled CNTs, which rises to 257 W m-1 K-1 when considering the CNT network alone. These values are remarkably high for randomly oriented CNT networks, roughly seven times that of single-walled CNT films. The enhanced thermal conduction is due to the additional wall, which likely gives rise to additional heat-carrying phonon modes and provides a certain resilience to defects. Our results demonstrate that free-standing double-walled CNT films efficiently dissipate heat, enhancing our understanding of these promising films and how they are suited to applications in EUV lithography.</p
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