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41.
Manuel Sánchez Julieta Fabienne Uicich Gustavo Francisco Arenas Exequiel Santos Rodríguez Pablo Ezequiel Montemartini Marcela Elisabeth Penoff 《应用聚合物科学杂志》2019,136(38):47979
Halloysite nanotubes (HNTs) have attracted a technologic and scientific attention as reinforcements of epoxy-based nanocomposites. However, their reported interaction with epoxy matrices is varied and the controlled dispersion of HNTs is still a challenge. In this work, we study the effect of chemical reactions taking place in the dispersion process of halloysite and their possible influence in the composite's properties. HNTs' surface was modified through an alkaline treatment and by grafting two aminosilanes with different chain lengths and functionality numbers. Evidence of homopolymerization and degradation reactions was found, depending on the surface treatment. The rheological study indicated that an interconnected network can be achieved in epoxy/HNTs blends depending on the surface chemical characteristics of the nanofillers and the blending method. The better dispersion was accomplished when ultrasonicating with the aid of a solvent. Nevertheless, the mechanical properties of the nanocomposites are not warranted by selecting a dispersion method. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47979. 相似文献
42.
43.
Fabienne Porée Amar Kachenoura Hervé Gauvrit Catherine Morvan Guy Carrault Lotfi Senhadji 《IEEE transactions on information technology in biomedicine》2006,10(2):293-301
This paper deals with the conception of a new system for sleep staging in ambulatory conditions. Sleep recording is performed by means of five electrodes: two temporal, two frontal and a reference. This configuration enables to avoid the chin area to enhance the quality of the muscular signal and the hair region for patient convenience. The electroencephalopgram (EEG), eletromyogram (EMG), and electrooculogram (EOG) signals are separated using the Independent Component Analysis approach. The system is compared to a standard sleep analysis system using polysomnographic recordings of 14 patients. The overall concordance of 67.2% is achieved between the two systems. Based on the validation results and the computational efficiency we recommend the clinical use of the proposed system in a commercial sleep analysis platform. 相似文献
44.
Claudine Gourgue Martine Champ Fabienne Guillon Jean Delort-Laval 《Journal of the science of food and agriculture》1994,64(4):493-499
Orange and lemon peels were extruded under controlled conditions of varying severity, and their physico-chemical characteristics and effect on the enzymatic hydrolysis of starch and glucose diffusion were studied. Extrusion-cooking treatment increased the soluble fraction of dietary fibre as well as solubilised pectic substances and arabino-galactomannan chains. The apparent viscosities of aqueous extracts of extruded fibre were increased slightly for orange and more markedly for lemon fibre. With both fibre sources, viscosities values were higher in Tris-maleate buffer (0.1 M) than in NaCl (154 mM). However, these modifications had no effect on starch hydrolysis and glucose diffusion in vitro. 相似文献
45.
Specificity of Pheromonal and Kairomonal Response of the Israeli Pine Bast Scale Matsucoccus josephi and Its Predator Elatophilus hebraicus 总被引:1,自引:0,他引:1
Ezra Dunkelblum Miriam Harel Fabienne Assael Kenji Mori Zvi Mendel 《Journal of chemical ecology》2000,26(7):1649-1657
It has been demonstrated previously that the sex pheromone of the Israeli pine bast scale, Matsucoccus josephi, (2E,5R,6E,8E)-5,7-dimethyl2,6,8-decatrien-4-one (1) is also a potent kairomone of the scale insect's predator Elatophilus hebraicus. Surprisingly, the sex pheromones of M. feytaudi (2) and M. matsumurae (3) also attract E. hebraicus. These results have prompted us to prepare a series of analogs of 1 with variations in the two moieties attached to the C=O group (4–9) in order to probe the structure–activity relationship of the pheromonal/kairomonal response of M. josephi and E. hebraicus. The most selective and active pheromone analog is 8, attracting only M. josephi males and the most selective and active kairomone analog is the M. feytaudi pheromone 2, attracting only adults of E. hebraicus. A dose–response field test of these analogs and the chiral and racemic M. josephi pheromone 1 indicates that the specificity is maintained at a broad range between 25 and 400 g corresponding to 1. Analog 5, which is neither a parapheromone nor a kairomone, and analog 8, which is only a parapheromone, are not inhibitory to M. josephi or to E. hebraicus. Our study indicates that alterations in the diene side chain of 1, common to all three Matsucoccus pheromones, strongly reduce the kairomonal activity while structural changes in the second side chain significantly reduce the pheromonal activity. The discovery of selective analogs of 1 has practical implications and enables specific monitoring of M. josephi or E. hebraicus. Particularly important is the possibility to mass-trap males of M. josephi without reducing the population of E. hebraicus. 相似文献
46.
The structural characterization of polyesters of citric acid (CA) with ethylene glycol and long‐chain aliphatic alcohols (ROH), prepared by the composition of the reaction mixture being adjusted slightly away from stoichiometric equivalence, was performed with 1H‐ and 13C‐NMR spectroscopy. The aliphatic alcohols employed were 1‐decanol, 1‐dodecanol, and 1‐octadecanol. The 13C‐NMR carbonyl region presented four groups of signals, two corresponding to the ester groups and two corresponding to the acid groups. However, symmetric and asymmetric groups of CA moieties were identified in the 13C‐NMR spectra. The ester yield from ROH decreased as the number of carbon atoms in the alcohols increased. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 302–306, 2003 相似文献
47.
Narjs Toumi Fabienne Kajo Didier Fournier Francis Vocanson Roger Lamartine Isabelle Dumazet-Bonnamour 《Materials science & engineering. C, Materials for biological applications》2008,28(5-6):645-652
This article describes a convenient and effective method to study the extraction properties of unsupported calixarenes used as solid extracting agents. The solid–liquid extraction properties of different functionalized calixarene derivatives were studied. This method was compared to classic liquid–liquid extractions. The reproducibility of the solid–liquid extractions was studied among with the calixarene recycling. Results obtained for Cu2+, Cd2+and Pb2+extractions using both methods have revealed the interest to use calixarenes as solid extracting agents. Moreover, a study of selective extraction has been carried out. 相似文献
48.
Jérome Roger Fabienne Audubert Yann Le Petitcorps 《Journal of Materials Science》2008,43(11):3938-3945
Solid-state reactions between SiC films and W–xRe (x = 0, 5 and 25 at%) substrates on thermal annealing between 1673 K and 1873 K for various durations have been investigated.
SiC coatings were deposited on metallic wires by hot filament chemical vapour deposition (HFCVD) from a gas mixture of tetramethylsilane
(TMS) and hydrogen at 1373 K under normal pressure. The interface zones were characterized using scanning electron and optical
microscopies, X-ray diffraction and electron microprobe microanalysis. All analyses reveal that SiC reacts with substrates.
Various metal silicides and carbides were formed in layered reaction and the presence of these phases was confirmed by electron
probe microanalysis. The effects of rhenium on the reactivity were established by the determination of growth kinetics deducted
from the thicknesses of reaction zones as a function of annealing time. It has been found that an increase in the diffusion
kinetics and activation energy with the quantity of rhenium in the tungsten wire. 相似文献
49.
Maxime Bertin Fabienne Touchard Marie-Christine Lafarie-Frenot 《International Journal of Hydrogen Energy》2010
Fast filling of hydrogen pressure tank leads to thermomechanical stresses in vessel structure. In this paper, the aim is to study the thermomechanical behaviour of the material used in the vessel structure. Flat coupons made of the same constituents as the hydrogen tank materials and with different stacking sequences have been tested under quasi-static tensile tests and fatigue. Three types of fatigue tests have been performed in order to understand damage mechanisms due to interactions between thermal and mechanical stresses: thermomechanical fatigue, 1 Hz mechanical fatigue and mechanical fatigue with a constant stress level stage. Damage development has been followed by acoustic emission and microscopic observations. Results show that, whatever the applied loading, there is a significant influence of the stacking sequence of the composite part. Moreover, the comparison of the material response to the different types of fatigue has revealed the harmful role of coupled temperature/mechanical cyclic stresses. 相似文献
50.
Fabian Hogenkamp Fabienne Hilgers Nora Lisa Bitzenhofer Vera Ophoven Mona Haase Dr. Claus Bier Dr. Dennis Binder Prof. Dr. Karl-Erich Jaeger Dr. Thomas Drepper Prof. Dr. Jörg Pietruszka 《Chembiochem : a European journal of chemical biology》2022,23(1):e202100467
Photocaged compounds are applied for implementing precise, optochemical control of gene expression in bacteria. To broaden the scope of UV-light-responsive inducer molecules, six photocaged carbohydrates were synthesized and photochemically characterized, with the absorption exhibiting a red-shift. Their differing linkage through ether, carbonate, and carbamate bonds revealed that carbonate and carbamate bonds are convenient. Subsequently, those compounds were successfully applied in vivo for controlling gene expression in E. coli via blue light illumination. Furthermore, benzoate-based expression systems were subjected to light control by establishing a novel photocaged salicylic acid derivative. Besides its synthesis and in vitro characterization, we demonstrate the challenging choice of a suitable promoter system for light-controlled gene expression in E. coli. We illustrate various bottlenecks during both photocaged inducer synthesis and in vivo application and possibilities to overcome them. These findings pave the way towards novel caged inducer-dependent systems for wavelength-selective gene expression. 相似文献