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271.
272.
Dérue C Gibouin D Verdus MC Lefebvre F Demarty M Ripoll C Thellier M 《Microscopy research and technique》2002,58(2):104-110
In the search for a new methodological approach applicable to the determination of the still poorly known primary role of boron in plant physiology, we have undertaken to appraise the potential of the SIMS method for the analytical imaging of the boron isotopes, (10)B and (11)B, at physiological concentrations in plants. With our own, CAMECA IMS4F SIMS ion analyser, and using O(2)(+) as primary ions for the detection of B(+) (plus (12)C(+) and (40)Ca(+)) secondary ions, we have been able to map quantitatively the two boron isotopes in control and boron-enriched plants, to evaluate boron concentrations at the level of individual cells and to determine boron isotopic ratios. This provides the opportunity to carry out the simultaneous labeling and imaging of boron, using enrichment with the stable isotopes, (10)B and (11)B. The method has also the potential for the simultaneous, quantitative detection of the boron isotopes and of the borate-binding sites in plant cells. 相似文献
273.
13C CP-MAS and DP-MAS spin-counting experiments have been carried out on an absolute basis for a specific whole soil and its humin, humic acid, and fulvic acid fractions, as well as a sample of the soil that was treated with 2% HF(aq). The results confirm previous conclusions that a substantial fraction of the carbon content indicated by classic elemental analysis is missed in some samples, especially whole soil and humin, by both CP-MAS and DP-MAS 13C NMR methods, and that the problem is more serious for CP-MAS than for DP-MAS. This study also confirms the fact that treatment of soil organic matter with 2% HF(aq) dramatically reduces this problem but may generate some structural uncertainties associated with significant structural alterations that accompany the HF(aq) treatment, as indicated by the 13C NMR data. The relationship between the "missing carbon" problem and the concentration of paramagnetic centers, especially Fe(III) centers, is explored in substantial detail. 相似文献
274.
The recent Supreme Court ruling (Jaffee v. Redmond, 1996) recognizing a psychotherapist–patient privilege under Rule 501 of the Federal Rules of Evidence is discussed. The article provides (a) background information on the issues of privileged communication and confidentiality in counseling; (b) an overview of the Jaffee case; (c) clarification for therapists and their legal counsel regarding the implications of the Supreme Court's ruling; (d) examples of therapy situations to which ruling might apply; and (e) an opinion that Jaffee provides the basis for persuasive argument that the psychotherapist–patient privilege should be recognized in all courts. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
275.
Gas permeability of pyrocarbon (PyC) coatings of Biso fuel particles for high temperature gas cooled reactors has been evaluated by various methods both physical and physical chemistry measurements. It was established that the gaseous chlorine leach method associated with ceramographic examinations of ThO2 kernels is more suitable than PyC texture tests for routine control; the flow measurement of a labelled gas (14CO2) accross the PyC coating is a technique available only in the laboratory. Moreover, it seems that the pore volume-size distribution is related to the permeability which would be rather attributed to the micropores. 相似文献
276.
High-throughput droplet digital PCR system for absolute quantitation of DNA copy number 总被引:3,自引:0,他引:3
Hindson BJ Ness KD Masquelier DA Belgrader P Heredia NJ Makarewicz AJ Bright IJ Lucero MY Hiddessen AL Legler TC Kitano TK Hodel MR Petersen JF Wyatt PW Steenblock ER Shah PH Bousse LJ Troup CB Mellen JC Wittmann DK Erndt NG Cauley TH Koehler RT So AP Dube S Rose KA Montesclaros L Wang S Stumbo DP Hodges SP Romine S Milanovich FP White HE Regan JF Karlin-Neumann GA Hindson CM Saxonov S Colston BW 《Analytical chemistry》2011,83(22):8604-8610
Digital PCR enables the absolute quantitation of nucleic acids in a sample. The lack of scalable and practical technologies for digital PCR implementation has hampered the widespread adoption of this inherently powerful technique. Here we describe a high-throughput droplet digital PCR (ddPCR) system that enables processing of ~2 million PCR reactions using conventional TaqMan assays with a 96-well plate workflow. Three applications demonstrate that the massive partitioning afforded by our ddPCR system provides orders of magnitude more precision and sensitivity than real-time PCR. First, we show the accurate measurement of germline copy number variation. Second, for rare alleles, we show sensitive detection of mutant DNA in a 100,000-fold excess of wildtype background. Third, we demonstrate absolute quantitation of circulating fetal and maternal DNA from cell-free plasma. We anticipate this ddPCR system will allow researchers to explore complex genetic landscapes, discover and validate new disease associations, and define a new era of molecular diagnostics. 相似文献
277.
Lipo‐Protein Emulsion Structure in the Diet Affects Protein Digestion Kinetics,Intestinal Mucosa Parameters and Microbiota Composition 下载免费PDF全文
Marion Oberli Véronique Douard Martin Beaumont Daphné Jaoui Fabienne Devime Sandy Laurent Catherine Chaumontet Damien Mat Steven Le Feunteun Camille Michon Anne‐Marie Davila Gilles Fromentin Daniel Tomé Isabelle Souchon Marion Leclerc Claire Gaudichon François Blachier 《Molecular nutrition & food research》2018,62(2)
278.
Nicolas Ducoulombier Camille Chateau Michel Bornert Jean-François Caron Patrick Aimedieu Timm Weitkamp Jonathan Perrin Andrew King Mario Scheel 《Strain》2020,56(6):e12347
For the last decades, new reparation or fabrication processes have been studied to replace traditional rebar by roving of different mineral or organic fibres to avoid corrosion issues. Such materials refer to the family of cementitious composite. Their tensile strength would directly depend on the proportion of reinforcement and strongly on the interfacial mechanical properties between fibres and cementitious matrix. From now, evaluation of interfacial properties was mostly limited to the use of force–displacement curves obtained from mechanical experiments. This work presents a new methodology using micromechanical tension stiffening tests combined with X-ray computed tomography (XRCT) observations, performed at the Anatomix beamline at Synchrotron SOLEIL, and specific image processing procedures. Multi-XRCT acquisitions with suitable scanning strategy are used to image the whole fibre-matrix interface along centimetric samples at four to five different levels of loading magnitude. Intensive image processing is then performed on tomographic images including digital volume correlation (DVC), image subtraction and Hessian-based filtering. This experiment allows to study damage mechanisms at small scale. The proposed methodology shows great potential to provide both qualitative and quantitative elements on interfacial mechanical behaviour such as crack growth and crack orientation. The interface between mortar and sufficiently small multi-fibre yarn used in this paper is shown to behave in certain condition as traditional rebar interface producing conical cracks in the surrounding matrix rather than debonding in mode 2, permitting a much higher energy dissipation during debonding. According to this study, conical cracks repartition and geometry are mostly influenced by the cementitious matrix. The spacing between cracks goes from 50 to 100 μm, and the angle between crack normal vector and yarn orientation goes from 35° to 50°. 相似文献
279.
Sanket Samal Heejung Roh Camille E. Cunin Geon Gug Yang Aristide Gumyusenge 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(18):2207554
Iono-electronics, that is, transducing devices able to translate ionic injection into electrical output, continue to demand a variety of mixed ionic–electronic conductors (MIECs). Though polar sidechains are widely used in designing novel polymer MIECs, it remains unclear to chemists how much balance is needed between the two antagonistic modes of transport (ion permeability and electronic charge transport) to yield high-performance materials. Here, the impact of molecularly hybridizing ion permeability and charge mobility in semiconducting polymers on their performance in electrochemical and synaptic transistors is investigated. A series of diketopyrrolopyrrole (DPP)-based copolymers are employed to demonstrate the multifunctionality attained by controlling the density of polar sidechains along the backbone. Notably, efficient electrochemical signal transduction and reliable synaptic plasticity are demonstrated via controlled ion insertion and retention. The newly designed DPP-based copolymers further demonstrate unprecedented thermal tolerance among organic mixed ionic–electronic conductors, a key property in the manufacturing of organic electronics. 相似文献
280.
Vincent Varlet Thierry Serot Camille Knockaert Josiane Cornet Mireille Cardinal Fabrice Monteau Bruno Le Bizec Carole Prost 《Journal of the science of food and agriculture》2007,87(5):847-854
Four industrial processes for smoking food were studied through their effects on the organoleptic properties of smoked salmon and on the occurrence of 20 polycyclic aromatic hydrocarbons (PAHs) known as being contaminants of smoking processes. The contamination by PAHs of the food might be measured by their corresponding toxic equivalent quantity (TEQ) expressed in µg kg?1. The results show a significant correlation between the smoking process parameters, the odour of the smoked fish and the presence of PAHs. Smouldering, thermostated plates and friction smoking processes allow smoked fish with very close odorant characteristics to be obtained. However, differences of pyrolysis temperature (between 380 and 500 °C) causes significant differences of PAHs concentration even if the contents are under the legal threshold concerning benzo(a)pyrene (5 µg kg?1). Smoked fish obtained by liquid smoke vaporisation presented the lowest level of PAHs but benzo(a)pyrene concentration is nevertheless important. The odours brought by the liquid smoke process are more ‘cold smoke’ and ‘vegetal/green’ than the other techniques, which are smokier and fishier. Copyright © 2007 Society of Chemical Industry 相似文献