Search results for "C-S"
showing 10 items of 151 documents
Comprehensive analysis of expression, subcellular localization, and cognate pairing of SNARE proteins in oligodendrocytes
2009
Oligodendrocytes form the central nervous system myelin sheath by spiral wrapping of their plasma membrane around axons, necessitating a high rate of exocytic membrane addition to the growing myelin membrane. Membrane fusion is mediated by soluble N-ethylmaleimide-sensitive factor attachment protein receptor proteins (SNAREs), which act by specific pairing of vesicle (R)- and target (Q)-SNAREs. To characterize oligodendroglial SNAREs and their trafficking pathways, we performed a detailed expression analysis of SNAREs in differentiating cultured oligodendrocytes and myelin and determined their subcellular localization. Expression of the plasma membrane Q-SNAREs syntaxin 3, syntaxin 4, SNAP2…
High efficiency of Pt2+ - CeO2 novel thin film catalyst as anode for proton exchange membrane fuel cells
2016
Abstract The elevated price of Pt limits the large-scale implementation of commercial proton exchange membrane fuel cells, which effectively convert chemical energy into electricity. In order to increase the cost-efficiency in proton-exchange membrane fuel cells, we have designed a family of novel anode catalysts consisting of thin films of ceria with low Pt loadings sputtered on a nanostructured carbon support. Remarkably, only such small amounts of Pt are necessary for achieving power density values comparable to the reference commercial catalysts, which results in excellent specific activities of our samples. By combining photoelectron spectroscopy and catalytic performance analysis, we …
Revised Atomistic Models of the Crystal Structure of C–S–H with high C/S Ratio
2016
Abstract The atomic structure of calcium-silicate-hydrate (C1.67–S–H x ) has been studied. Atomistic C–S–H models suggested in our previous study have been revised in order to perform a direct comparison of energetic stability of the different structures. An extensive set of periodic structures of C–S–H with variation of water content was created, and then optimized using molecular dynamics with reactive force field ReaxFF and quantum chemical semiempirical method PM6. All models show organization of water molecules inside the structure of C–S–H. The new geometries of C–S–H, reported in this paper, show lower relative energy with respect to the geometries from the original definition of C–S…
In situ analysis of suspensions of calcium silicate hydrate : application to the study of ionics interactions at the surface of the particules
2014
This project aims to study the interactions between calcium silicate hydrate (C-S-H) and different anions (chlorides, bromides, nitrates and sulfates) in order to build a thermodynamic model and then be predictable. The simplified system CaO-SiO2-H2O is studied by synthesizing C-S-H suspensions and mixing them with different kind of salts (calcium salt or alkali salt). The influence of the temperature and the presence of aluminum in the structure of the C-S-H is also examined.A classical way to investigate this kind of system is to separate the liquid phase from the solid phase in order to analyze them separately. Nevertheless, this step has a large influence on the system, and the experime…
Determination of cholesterol in human milk: an alternative to chromatographic methods
2015
Introduction: human milk (HM) is considered the best option for feeding healthy infants. Cholesterol (CHOL) is important for proper development of the nervous system, and for hormone and vitamin synthesis in growing infants. Breastfeeding and dietary CHOL intake during infancy have been suggested to affect blood lipid levels and the risk of cardiovascular disease in adulthood. Gas chromatography is the technique most widely used to determine CHOL in HM. Chromatographic methods are specific for the determination of CHOL and other sterols present in HM, but are extremely time consuming, and the costs and equipment requirements mean that they are not accessible to all laboratories. Aim: the pr…
Multi-residue determination of organic micro-pollutants in river sediment by stir-disc solid phase extraction based on oxidized buckypaper
2020
This paper describes a procedure for the isolation of 20 organic micro-pollutants among pesticides, drugs, recreational drugs, flame retardants from river sediments. After a solid-liquid extraction with a methanol:water (50:50, v/v) solution, the supernatant was diluted with water and cleaned up by stir-disc solid-phase extraction (SPE). The disc was made of buckypaper, a self-supporting entangled assembly of carbon nanotubes, which was used as a highly porous, two-sided, sorbent membrane. In the preliminary activation step, the membrane was oxidised for 2-hours with nitric acid to extend its extraction capability also to more polar compounds. All extracts were analysed by ultra-high-perfor…
Induced Chirality in Confined Space on Halogen Gold Complexes
2015
The solubilization of HAuCl4 in toluene within optically active reverse micelles and lamellar structures formed by (1R,2S)-Dodecyl(2-hydroxy-1-methyl-2-phenylethyl)- dimethylammonium bromide (DMEB) has allowed us to evidence the complex phenomenology accompanying the confinement of Au salt within these nanostructures. Together with a chloride/bromide exchange process occurring in the first coordination sphere of an Au ion, UV−vis and electronic circular dichroism (ECD) spectra reveal the appearance of an induced dichroic signal attributable to Au complexes entrapped in the hydrophilic domain of the DMEB chiral nanostructures. Interestingly, change of the effective oxidation state and coordi…
Complexation behaviour of hexadentate ligands possessing N2O4and N2O2S2cores: differential reactivity towards Co(ii), Ni(ii) and Zn(ii) salts and str…
2004
Reactions of divalent metal salts of Co, Ni and Zn with 1,2-di(salicylaldimino-o-phenylthio) ethane (H2L1) and 1,2-di(naphthaldimino-o-phenylthio) ethane (H2L2), having N2O2S2 cores, and 1,2-di(O-salicylaldimino-o-hydroxyphenyl) ethane (H2L3), having a N2O4 core, have been explored. Out of the three ligands and the nine products obtained from the corresponding reactions, two ligands and seven products were crystallographically characterized. However, all the ligands and the products were characterized by analytical and spectral methods. Reaction of H2L1 and H2L2 with Co(II) salts results in oxidative cleavage of the C-S bond to produce a Co(III) product bound to two dissimilar tridentate li…
Src proteins/src genes: from sponges to mammals
2004
The genome of marine sponge Suberites domuncula, a member of the most ancient and most simple metazoan phylum Porifera, encodes at least five genes for Src-type proteins, more than, i.e., Caenorhabditis elegans or Drosophila melanogaster (two in each). Three proteins, SRC1SD, SRC2SD and SRC3SD, were fully characterized. The overall homology (identity+similarity) among the three S. domuncula Srcs (68-71%) is much lower than the sequence conservation between orthologous Src proteins from freshwater sponges (82-85%). It is therefore very likely that several src genes/proteins were already present in the genome of Urmetazoa, the hypothetical metazoan ancestor. We have identified in the S. domun…
Measurement of the inelastic proton-proton cross-section at √s = 7 TeV with the ATLAS detector
2011
The dependence of the rate of proton–proton interactions on the centre-of-mass collision energy, √s, is of fundamental importance for both hadron collider physics and particle astrophysics. The dependence cannot yet be calculated from first principles; therefore, experimental measurements are needed. Here we present the first measurement of the inelastic proton–proton interaction cross-section at a centre-of-mass energy, √s, of 7 TeV using the ATLAS detector at the Large Hadron Collider. Events are selected by requiring hits on scintillation counters mounted in the forward region of the detector. An inelastic cross-section of 60.3±2.1 mb is measured for ξ>5×10[superscript −6], where ξ is ca…