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1.
Summary. Several compounds may exist in LnCl3–MCl mixtures. Those corresponding to the M
2
LnCl5 and MLn
2Cl7 stoichiometries are formed in a few systems only, with diverse stability strongly dependent on both the corresponding lanthanide
and alkali metal. On the other hand, M
3
LnCl6 that occur in most systems have a far larger stability range and melt congruently. These latter compounds were investigated
in the present work by differential scanning calorimetry and electrical conductivity measurements. The thermodynamic and transport
properties were correlated to structural features and related to the mechanism of compound formation.
Corresponding author. E-mail: Marcelle.Gaune-Escard@polytech.univ-mrs.fr
Received October 2, 2002; accepted November 6, 2002
Published online April 24, 2003
RID="a"
ID="a" This paper is dedicated to Professor H. Gamsj?ger on the occasion of his birthday 相似文献
2.
Paulovich FV Maki RM de Oliveira MC Colhone MC Santos FR Migliaccio V Ciancaglini P Perez KR Stabeli RG Perinoto AC Oliveira ON Zucolotto V 《Analytical and bioanalytical chemistry》2011,400(4):1153-1159
Recent advances in the control of molecular engineering architectures have allowed unprecedented ability of molecular recognition in biosensing, with a promising impact for clinical diagnosis and environment control. The availability of large amounts of data from electrical, optical, or electrochemical measurements requires, however, sophisticated data treatment in order to optimize sensing performance. In this study, we show how an information visualization system based on projections, referred to as Projection Explorer (PEx), can be used to achieve high performance for biosensors made with nanostructured films containing immobilized antigens. As a proof of concept, various visualizations were obtained with impedance spectroscopy data from an array of sensors whose electrical response could be specific toward a given antibody (analyte) owing to molecular recognition processes. In addition to discussing the distinct methods for projection and normalization of the data, we demonstrate that an excellent distinction can be made between real samples tested positive for Chagas disease and Leishmaniasis, which could not be achieved with conventional statistical methods. Such high performance probably arose from the possibility of treating the data in the whole frequency range. Through a systematic analysis, it was inferred that Sammon's mapping with standardization to normalize the data gives the best results, where distinction could be made of blood serum samples containing 10(-7) mg/mL of the antibody. The method inherent in PEx and the procedures for analyzing the impedance data are entirely generic and can be extended to optimize any type of sensor or biosensor. 相似文献
3.
Blanka Kubikova Miroslav Boca Marcelle Gaune-Escard 《Monatshefte für Chemie / Chemical Monthly》2008,139(6):587-590
The phase equilibria in the K2TaF7–TaF5 binary system were determined up to x
TaF5 = 0.5 by means of differential scanning calorimetry. XRD diffraction analysis of solidified mixtures was performed. Besides
the K2TaF7 and KTaF6 phases, the presence of a third phase was observed, as well. It was suggested that the last phase melts incongruently.
Correspondence: B. Kubikova, Institute of Inorganic Chemistry SAS, Dúbravská cesta 9, Bratislava, 845 36, Slovakia. 相似文献
4.
2-(Per-O-acetyl-β-d-glycopyranosyl)-1,4-dimethoxybenzenes led to C-glycosyl-hydroquinones suitable for preparing C-glycosylated analogs of vitamin E, having the sugar moiety free or acetylated. 相似文献
5.
Marcelle Gaune-Escard A. Bogacz L. Rycerz W. Szczepaniak 《Journal of Thermal Analysis and Calorimetry》1995,45(5):1117-1124
Present work is a part of thermodynamic research program on the MX?LnX3 system (M=alkali metal,X=Cl, Br andLn=lanthanide). Molar enthalpies of mixing in the LiBr?NdBr3, NaBr?NdBr3 and KBr?NdBr3 liquid binary systems have been determined at temperature 1063 K by direct calorimetry in the whole range of composition. Investigated systems are generally characterized by negative enthalpies of mixing with minimum atX NdBr3≈0.3–0.4. These enthalpies decrease with decrease of ionic radii of alkali metals. Molar enthalpies of solid-solid and solid-liquid phase transitions of K3NdBr6 and Cs3NdBr6 have been also determined by differential scanning calorimetry (DSC). K3NdBr6 is formed at 689 K from KBr and K2NdBr5 with enthalpy of 44.0 kJ·mol?1 whereas Cs3NdBr6 is stable at ambient temperature and undergoes phase transition in the solid state at 731 K with enthalpy of 8.8 kJ·mol?1. Enthalpies of melting have been also determined. 相似文献
6.
Marcelle Hauteville Rolf Stomberg Marie-Christine Duclos 《Journal of chemical crystallography》1999,29(6):681-685
Benzylation of 3-methylphloracetophenone [1-(2,4,6-trihydroxy-3-methylphenyl)ethanone] (3) with benzyl chloride gave 4-acetyl-2,6-dibenzyl-1,5-dihydroxy-2-methylcyclohexa-4,6-dien-3-one (5). Compound 5 crystallizes in the orthorhombic space group Fdd2 with a = 17.586(2), b = 42.891(5), c = 10.279(2) Å, V = 7753(2) Å,3 and Z = 16. When crystals of 5 were dissolved in [D6]acetone the compound underwent tautomerization and a mixture of 5 and its keto form 4 was obtained (keto form/enol form ratio 1:4). 相似文献
7.
Rycerz Leszek Ingier-Stocka Ewa Gaune-Escard Marcelle 《Journal of Thermal Analysis and Calorimetry》2009,97(3):1015-1021
Journal of Thermal Analysis and Calorimetry - Phase equilibrium in the CeBr3–CsBr binary system was established from differential scanning calorimetry (DSC). This system includes three... 相似文献
8.
Marcelle de L. Ferreira Marcus V. N. de Souza Solange M. S. V. Wardell James L. Wardell Thatyana R. A. Vasconcelos Vitor F. Ferreira 《Journal of carbohydrate chemistry》2013,32(6):265-274
Five new bis-1,2,3-triazole derivatives from D-mannitol, namely 2,3,4,5-tetra-O-acetyl-1,6-dideoxy-1,6-bis-(4-substituted-1H-1,2,3-triazol-1-yl)-D-mannitol (4), have been synthesized from 2,3,4,5-tetra-O-acetyl-1,6-diazido-1,6-dideoxy-D-mannitol (3) and alkynes, employing copper (I)-catalyzed azide-alkyne cycloaddition (CuAAC) methodology. Evaluation of their in vitro antitubercular activity against Mycobacterium tuberculosis H37Rv using the Alamar Blue susceptibility test indicated poor activities. However, this study has provided information about the SAR of D-mannitol derivatives in the search for new anti-TB drugs based on this carbohydrate. 相似文献
9.
10.
Kouakou TH Kouadio YJ Kouamé P Waffo-Téguo P Décendit A Mérillon JM 《Applied biochemistry and biotechnology》2009,158(2):285-301
Polyphenol oxidases (PPOs) were isolated from cell suspensions of two cultivars of cotton (Gossypium hirsutum L.), and their biochemical characteristics were studied. PPO from Coker 312, an embryogenic cultivar, showed a highest affinity
to catechol 20 mM, and PPO from R405-2000, a nonembryogenic cultivar, showed a highest affinity to 4-methylcatechol 20 mM.
The optimal pH for PPO activity was 7.0 and 6.0 for Coker 312 and R405-2000, respectively. The enzyme had an optimal temperature
of 25 °C and was relatively stable at 20–30 °C. Reducing sodium metabisulfite, ascorbic acid, dithiothreitol, SnCl2, and FeCl3 markedly inhibited PPO activity, whereas its activity was highly enhanced by Mg2+, Ca2+, and Mn2+ and was moderately inhibited by Ba2+, Cu2+, and Zn2+. The analysis revealed a single band on the sodium dodecyl sulfate polyacrylamide gel electrophoresis which corresponded
to a molecular weight of 55 kDa for Coker 312 and 42 kDa for R405-2000. 相似文献