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131.
New upper-rim polyphosphorylated calix[4]arenes were designed for decorporation of uranium in case of nuclear contamination. A ligand system containing four preorganized 1-hydroxymethylene-1,1-bisphosphonic acid moieties anchored onto a calix[4]arene platform has been developed. Three calix[4]arene-bisphosphonates were efficiently prepared in multi-step syntheses with a variable carbon chain length between the bisphosphonate and the calix[4]arene. Affinity constants towards uranyl ion were determined and compared with those of bis(HEDP) and tris(HEDP) phosphonates, known as efficient ligands for uranyl. 相似文献
132.
Christian Ptrier Ricardo Torres-Palma Evelyne Combet Georgios Sarantakos Stphane Baup Csar Pulgarin 《Ultrasonics sonochemistry》2010,17(1):111-115
Sonochemical elimination of organic pollutants can take place through two degradation pathways. Molecules with relatively large Henry’s law constants will be incinerated inside the cavitation bubble, while nonvolatile molecules with low Henry’s law constants will be oxidised by the OH ejected from the bubble of cavitation. Taking bisphenol-A as a model pollutant, this study points out an alternate degradation route, mediated by bicarbonate ions, which is significant for the elimination of micro-pollutants at concentrations present in natural waters. In this process, OH radicals react with bicarbonate ions to produce the carbonate radical, which, unlike the OH radical, can migrate towards the bulk of the solution and therefore induce the degradation of the micro-pollutants present in the bulk solution. As a consequence, initial degradation rate is increased by a factor 3.2 at low concentration of bisphenol-A (0.022 μmol l−1) in presence of bicarbonate in water. 相似文献
133.
The benefits and limitations of reaction cell and sector field inductively coupled plasma mass spectrometry in the detection and quantification of phosphopeptides 下载免费PDF全文
134.
Carlo Martinotti Lanie Ruiz-Perez Dr. Evelyne Deplazes Prof. Ricardo L. Mancera 《Chemphyschem》2020,21(14):1486-1514
Cell membranes protect and compartmentalise cells and their organelles. The semi-permeable nature of these membranes controls the exchange of solutes across their structure. Characterising the interaction of small molecules with biological membranes is critical to understanding of physiological processes, drug action and permeation, and many biotechnological applications. This review provides an overview of how molecular simulations are used to study the interaction of small molecules with biological membranes, with a particular focus on the interactions of water, organic compounds, drugs and short peptides with models of plasma cell membrane and stratum corneum lipid bilayers. This review will not delve on other types of membranes which might have different composition and arrangement, such as thylakoid or mitochondrial membranes. The application of unbiased molecular dynamics simulations and enhanced sampling methods such as umbrella sampling, metadynamics and replica exchange are described using key examples. This review demonstrates how state-of-the-art molecular simulations have been used successfully to describe the mechanism of binding and permeation of small molecules with biological membranes, as well as associated changes to the structure and dynamics of these membranes. The review concludes with an outlook on future directions in this field. 相似文献
135.
Refinement of the inversion‐transfer NMR experiment for faster characterization of chemical exchange 下载免费PDF全文
Evelyne Baguet 《Magnetic resonance in chemistry : MRC》2016,54(1):51-57
It is shown theoretically that the inversion‐transfer experiment used to estimate the value of unidirectional rate constants in chemical exchange systems can be performed faster via a reduction of the recovery delay. The chemical exchange rate constants can then be estimated accurately with a formula close to that of standard inversion transfer and easy to use, after a justified approximation. A function was developed to determine the optimal value of the recovery delay for an optimal inversion‐transfer sequence. The validity of these theoretical results was checked experimentally with a solution of N,N‐dimethylacetamide in which chemical exchange arises from internal hindered rotation. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
136.
Ag2S forms with GeS2 stable glasses over a wide range of compositions (0–55% Ag2S mol%). In the same system, more complex glasses obtained by dissolving silver iodide have been synthesized with up to 50 mol% AgI.Raman spectra are presented and a vibrational assignment in terms of bridging and non-bridging sulfur has been made. The electrical conductivity of these glasses has been measured over a temperature range (?50°C? + 50°C) and for various compositions by the complex impedance diagram method. At 25°C, the conductivity reached a maximum value of 6 × 10?3 Ω?1 cm?1. Whatever the glass used, the same limit value of conductivity ) and activation energy () are obtained for the highest content of silver iodide. A conduction mechanism is proposed. 相似文献
137.
Ulrich A. Handge Igor M. Sokolov Alexander Blumen Evelyne Kolb Eric Clément 《Journal of Macromolecular Science: Physics》2013,52(5-6):971-980
We investigated the fragmentation of thin coatings on substrates under uniaxial tension. Theoretical models based on linear elasticity predict a power-law dependence of the mean fragment length < L> on the strain e to which the substrate is subjected: namely, one has <L> ∞??α with α ≤ 1/2. Experimentally, such a relation is obeyed in the fragmentation of thin SiO x coatings on polyethylene terephthalate (PET) substrates. In our experiments, we used brittle paints to coat rubber substrates: the ensuing mean fragment lengths also obey power laws in ?: we found, however, α = 0.71 ± 0.03. Such values of α can be reproduced theoretically by taking into account the nonlinearity of the coupling between coating and substrate. 相似文献
138.
Catherine M Halliwell Evelyne Simon Chee Seng Toh Anthony E G Cass Philip N Bartlett 《Bioelectrochemistry (Amsterdam, Netherlands)》2002,55(1-2):21-23
The immobilization of the mutants of L-lactate dehydrogenase (LDH) on poly(aniline) (PANi) composite films has been investigated. Mutants possessing peptide tags of varying charge and nucleophilicity were created to probe the nature of the interaction between the protein and PANi. These results are significant for the development of a 'generic' approach to the immobilization of enzymes and other proteins. 相似文献
139.
A method allowing the identification of parameters that govern constitutive equations of materials is proposed in this Note. These parameters are identified from heterogeneous strain fields. The method is direct so that iterative calculations based on finite element model updating are avoided. To cite this article: M. Grédiac et al., C. R. Mecanique 330 (2002) 107–112. 相似文献
140.
Evelyne Miot 《Communications in Mathematical Physics》2016,346(2):469-482
We prove uniqueness for the Vlasov–Poisson system in two and three dimensions under the condition that the Lp norms of the macroscopic density grow at most linearly with respect to p. This allows for solutions with logarithmic singularities. We provide explicit examples of initial data that fulfill the uniqueness condition and that exhibit a logarithmic blow-up. In the gravitational two-dimensional case, such states are intimately related to radially symmetric steady solutions of the system. Our method relies on the Lagrangian formulation for the solutions, exploiting the second-order structure of the corresponding ODE. 相似文献