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421.
Guillaume Calvez Carole Daiguebonne Olivier Guillou Tanja Pott Philippe Méléard Florence Le Dret 《Comptes Rendus Chimie》2010,13(6-7):715-730
Lanthanide containing octahedral hexanuclear complexes with general chemical formula [Ln6O(OH)8(NO3)6(H2O)x].2NO3.yH2O where Ln = Ce–Lu (except Pm) or Y, x = 0, 6, 12, 14 or 16 and y = 0, 2, 4 or 5 constitute a great family of polymorphic compounds. The synthesis and the crystal structures of all these compounds are overviewed. The hydration/dehydration processes that allow the structural transitions from one compound to another are described. The crystal structure of compounds with general chemical formula [Ln6O(OH)8(NO3)6(H2O)6].2NO3 where Ln = Ce–Lu (except Pm) or Y is described. It has been solved on the basis of a powder XRD diagram. The use of such hexanuclear complexes as molecular precursors for new materials is also discussed. 相似文献
422.
Montserrat Cortina-Puig Xavier Muñoz-Berbel Carole Calas-Blanchard Jean-Louis Marty 《Talanta》2009,79(2):289-12
This paper describes the characterization and optimization of an amperometric cytochrome c (cyt c)-based sensor for the determination of the antioxidant capacity of pure substances and natural samples. The cyt c and the xanthine oxidase (XOD) enzyme were co-immobilized on the electrode using the combination of several long-chain thiols. The self-assembled monolayer (SAM) was optimized in terms of composition and ratio between thiols. The immobilization protocol for both cyt c and XOD and the SAM formation time were evaluated through electrochemical methods, such as cyclic voltammetry (CV), square wave voltammetry (SWV), chronoamperometry (CA) and impedance spectroscopy (IS). Finally, the biosensor was applied to the determination of the antioxidant capacity of pure alliin and two compounds extracted from garlic bulbs. 相似文献
423.
Sophie Romain Dr. Carole Duboc Dr. Frank Neese Prof. Eric Rivière Dr. Lyall R. Hanton Dr. Allan G. Blackman Dr. Christian Philouze Dr. Jean‐Claude Leprêtre Prof. Alain Deronzier Dr. Marie‐Noëlle Collomb Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(4):980-988
The mononuclear manganese bis‐terpyridine complex [Mn(tolyl‐terpy)2](X)3 ( 1 (X)3; X=BF4, ClO4, PF6; tolyl‐terpy=4′‐(4‐methylphenyl)‐2,2′:6′,2“‐terpyridine), containing Mn in the unusual +III oxidation state, has been isolated and characterised. The 1 3+ ion is a rare example of a mononuclear MnIII complex stabilised solely by neutral N ligands. Complex 1 3+ is obtained by electrochemical oxidation of the corresponding MnII compound 1 2+ in anhydrous acetonitrile. Under these conditions the cyclic voltammogram of 1 2+ exhibits not only the well‐known MnII/MnIII oxidation at E1/2=+0.91 V versus Ag/Ag+ (+1.21 V vs. SCE) but also a second metal‐based oxidation process corresponding to MnIII/MnIV at E1/2=+1.63 V (+1.93 V vs. SCE). Single crystals of 1 (PF6)3?2 CH3CN were obtained by an electrocrystallisation procedure. X‐ray analysis unambiguously revealed its tetragonally compressed octahedral geometry and high‐spin character. The electronic properties of 1 3+ were investigated in detail by magnetic measurements and theoretical calculations, from which a D value of +4.82 cm?1 was precisely determined. Density functional and complete active space self consistent field ab initio calculations both correctly predict a positive sign of D, in agreement with the compressed tetragonal distortion observed in the X‐ray structure of 1 (PF6)3?2 CH3CN. The different contributions to D were calculated, and the results show that 1) the spin–orbit coupling part (+2.593 cm?1) is predominant compared to the spin–spin interaction (+1.075 cm?1) and 2) the excited triplet states make the dominant contribution to the total D value. 相似文献
424.
Matrix metalloproteinase-7 facilitates immune access to the CNS in experimental autoimmune encephalomyelitis 总被引:1,自引:0,他引:1
Lillian A Buhler Ramsey Samara Esther Guzman Carole L Wilson Liljana Krizanac-Bengez Damir Janigro Douglas W Ethell 《BMC neuroscience》2009,10(1):17
Background
Metalloproteinase inhibitors can protect mice against experimental autoimmune encephalomyelitis (EAE), an animal model for multiple sclerosis (MS). Matrix metalloproteinase-9 (MMP-9) has been implicated, but it is not clear if other MMPs are also involved, including matrilysin/MMP-7 – an enzyme capable of cleaving proteins that are essential for blood brain barrier integrity and immune suppression. 相似文献425.
Cover Picture: An Experimental and Theoretical Investigation on Pentacoordinated Cobalt(III) Complexes with an Intermediate S=1 Spin State: How Halide Ligands Affect their Magnetic Anisotropy (Chem. Eur. J. 3/2016)
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426.
Ihab Dika Frédéric Diot Véronique Bardinal Jean-Pierre Malval Carole Ecoffet Aurélien Bruyant David Barat Benjamin Reig Jean-Baptiste Doucet Thierry Camps Olivier Soppera 《Journal of polymer science. Part A, Polymer chemistry》2020,58(13):1796-1809
Near infrared (NIR) activable photopolymers suitable for versatile fabrication of micro-optical elements were developed. The first main objective of this article is to show that these new photopolymers can be used for microfabrication and investigate the parameters governing the microfabrication process. The impact of photonic, physico-chemical, and chemical parameters is discussed. High quality microstructures with a good control over their size and shape are demonstrated. The second main objective is to show practical examples of microlenses and waveguides implemented on single core and multiple core optical fibers, VCSELs, and glass slides are then presented. The NIR photosensitivity of this negative tone photoresists allows using the device source itself as to start the crosslinking process, which constitutes a convenient approach for micro-optics self-positioning on NIR sources and justifies the interest of such NIR photopolymer for the fabrication micro-optical elements and optical interconnects. 相似文献
427.
428.
429.
Gilberto Siqueira Carole Fraschini Julien Bras Alain Dufresne Robert Prud’homme Marie-Pierre Laborie 《European Polymer Journal》2011,47(12):2216-2227
Polycaprolactone (PCL)/cellulose nanocomposites were prepared by mixing PCL with surface modified sisal nanowhiskers (CNW) and microfibrillated cellulose (MFC) extracted from sisal fibers. The influence of cellulosic nanoparticles on the crystallization behavior of PCL was investigated by differential scanning calorimetry. Isothermal crystallization data were modeled with Avrami’s kinetics, Lauritzen–Hoffman secondary nucleation theory and equilibrium melting points were determined with the Hoffman–Weeks method. The cellulose nanoparticles, acting as nucleating agents, drastically accelerate the crystallization of PCL while depressing its equilibrium melting by 9–10 °C. The crystallization of MFC-nanocomposites is slightly faster than that of CNW-nanocomposites, in agreement with the slightly lower bulk activation energy for crystallization and nucleation parameter in the former. The results are discussed based on the differences of specific surface area and surface chemistry of nanoparticles, as well as the confinement phenomenon. 相似文献
430.