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排序方式: 共有415条查询结果,搜索用时 15 毫秒
31.
32.
Highly Axial Magnetic Anisotropy in a N3O5 Dysprosium(III) Coordination Environment Generated by a Merocyanine Ligand 下载免费PDF全文
Pramila Selvanathan Gang Huang Thierry Guizouarn Dr. Thierry Roisnel Dr. Guglielmo Fernandez‐Garcia Dr. Federico Totti Dr. Boris Le Guennic Dr. Guillaume Calvez Dr. Kévin Bernot Dr. Lucie Norel Prof. Stéphane Rigaut 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(43):15222-15226
A spiropyran‐based switchable ligand isomerizes upon reaction with lanthanide(III) precursors to generate complexes with an unusual N3O5 coordination sphere. The air‐stable dysprosium(III) complex shows a hysteresis loop at 2 K and a very strong axial magnetic anisotropy generated by the merocyanine phenolate donor. 相似文献
33.
Toward the Rational Design of Galactosylated Glycoclusters That Target Pseudomonas aeruginosa Lectin A (LecA): Influence of Linker Arms That Lead to Low‐Nanomolar Multivalent Ligands 下载免费PDF全文
Dr. Shuai Wang Lucie Dupin Mathieu Noël Cindy J. Carroux Dr. Louis Renaud Dr. Thomas Géhin Albert Meyer Dr. Eliane Souteyrand Dr. Jean‐Jacques Vasseur Dr. Gérard Vergoten Dr. Yann Chevolot Dr. François Morvan Dr. Sébastien Vidal 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(33):11785-11794
Anti‐infectious strategies against pathogen infections can be achieved through antiadhesive strategies by using multivalent ligands of bacterial virulence factors. LecA and LecB are lectins of Pseudomonas aeruginosa implicated in biofilm formation. A series of 27 LecA‐targeting glycoclusters have been synthesized. Nine aromatic galactose aglycons were investigated with three different linker arms that connect the central mannopyranoside core. A low‐nanomolar (Kd=19 nm , microarray) ligand with a tyrosine‐based linker arm could be identified in a structure–activity relationship study. Molecular modeling of the glycoclusters bound to the lectin tetramer was also used to rationalize the binding properties observed. 相似文献
34.
Christophe O. Soulage Lucie Grand Alain Géloën Stéphane Chambert 《Tetrahedron letters》2012,53(5):480-483
A straightforward procedure leading to the flavone cirsimaritin and its 4′-O-β-d-glycosylation to afford cirsimarin, its corresponding flavone glucopyranoside, is described. The biological properties of cirsimarin, measured on human adipocytes, showed potent effects on both lipolysis and lipogenesis. Cirsimarin could therefore be considered as an efficient tool in the struggle against excessive adipose tissue deposition and as a potential candidate in the treatment of obesity. 相似文献
35.
X-ray diffraction and ultrasonic measurements have been carried out simultaneously up to 7 GPa at ambient temperature on a polycrystalline sample of Fe64Ni36 Invar alloy. The bulk modulus is found to increase linearly with pressure with an unusual low value (1.4) of dB/dP up to about 3.1(2) GPa followed by a regular slope (3.6) at higher pressure. The observation of these two distinct regimes is in qualitative agreement with previous results on the variation of the iron magnetic moment, and can be interpreted using the 2gamma-state model in terms of gradual population of low spin-small volume state at the expense of the high spin-large volume state under pressure. 相似文献
36.
Nováková L Solich P Matysová L Sícha J 《Analytical and bioanalytical chemistry》2004,379(5-6):781-787
This paper deals with the development of a novel method for simultaneous determination of estradiol, its degradation product estrone, and two preservatives, methylparaben and propylparaben, in the topical preparation Estradiol HBF. After optimization of the analytical conditions the method was validated and applied in studies of the stability of the topical preparation Estrogel HBF. Separation of all these compounds was performed on a Supelco Discovery C18 (250 mm×3.0 mm, 5 m) analytical column. A mixture of acetonitrile, methanol, and water (23:24:53 v/v) was chosen as mobile phase. UV absorbance at 225 nm was used for detection and quantitation of analytes. The total analysis time was less than 12 min at a flow rate of 0.9 mL min–1. All the compounds were isolated from the topical gel by simple extraction with an acetonitrile solution of hydrocortisone, as internal standard, and using sonication and centrifugation thereafter. The supernatant was injected directly on to the analytical column. The recovery of the procedure was from 96.9 to 100.4%. Validation of method according international guidelines was successfully performed. 相似文献
37.
Pavlína Peikertová Lenka Kulhánková Lucie Neuwirthová Jonáš Tokarský 《Chemical Papers》2017,71(2):379-385
Conducting polymer polyaniline which is nowadays in forefront of the interest was in our study prepared in a form of thin films from anilinium sulfate by its chemical oxidation using ammonium peroxydisulfate. During the oxidation process, the polyaniline was deposited on glass slides and immersed into reaction mixture. Two sets of polyaniline thin films were prepared with different oxidation times (10, 20, 30, and 40 min). The first set was kept dry in desiccator and the second one was freely exposed to air moisture. Raman spectroscopy, nondestructive technique which is very sensitive to changes in structure of polymers, was used for the characterization of the protonation state of prepared polyaniline thin films. It was found that storage conditions affect the protonation state which in case of samples kept in desiccator is maintained without significant changes for longer time. Raman spectroscopy also revealed the dependence of protonation state on the oxidation time and 10 min proved as not sufficient for the creation of the protonation form of polyaniline. 相似文献
38.
Twenty nine phenolic compounds comprising nine phenolic acids, sixteen flavonoids (including eight tea catechins, glycosides and aglycones), four coumarins plus caffeine were analysed within 20 min using ultra high performance liquid chromatography (UHPLC) with PDA detection. UHPLC system was equipped with C18 analytical column (100 mm × 2.1 mm, 1.7 μm), utilising 0.1% formic acid and methanol mobile phase in the gradient elution mode. The developed method was tested for the system suitability: resolution, asymmetry factor, peak capacity, retention time repeatability and peak area repeatability. The method was fully validated in the terms of linearity (r2 > 0.9990 for all 30 compounds), range (typically 1-100 mg L−1), LOD, LOQ, inter/intra-day precision (<3% and <9% respectively) and inter/intra-day accuracy (typically 100 ± 10%). Subsequently the method was applied to the identification (spectral information and peak purity calculations were profited) and quantification of phenolic compounds and caffeine present in tea infusions and extracts. 相似文献
39.
Lucie Strnadlová Petra Šulcová Mario Llusar 《Journal of Thermal Analysis and Calorimetry》2010,100(2):661-665
The inorganic ceramic compounds based on the CeO2 belong into the group of high-temperature pigments. The pigments have been prepared by the classical dry process (i.e. solid-state
reaction) in the temperature range from 1,300 to 1,600 °C and by the coprecipitation at the three different temperatures:
400, 600 and 1,100 °C. The principal of these pigments makes the host lattice of the CeO2, which is doped by terbium ions. This incorporation of the doped ions leads to obtaining of the interesting dark orange colour
after application into ceramic glaze. The aim of our research was to improve and optimize the synthesis conditions of these
pigments. The samples were submitted to thermal analysis (TG–DTA) for determination of the temperature interval of the pigment
formation and the thermal stability of pigments. The compounds were also measured from the point of view of their colouring,
structure and particle size distribution. 相似文献
40.
Lucie Loukotková Eva Tesařová Zuzana Bosáková Pavel Repko Daniel W. Armstrong 《Journal of separation science》2010,33(9):1244-1254
Retention and enantioseparation behavior of ten 2,2′‐disubstituted or 2,3,2′‐trisubstituted 1,1′‐binaphthyls and 8,3′‐disubstituted 1,2′‐binaphthyls, which are used as catalysts in asymmetric synthesis, was investigated on eight chiral stationary phases (CSPs) based on β‐CD, polysaccharides (tris(3,5‐dimethylphenylcarbamate) cellulose or amylose CSPs) and new synthetic polymers (trans‐1,2‐diamino‐cyclohexane, trans‐1,2‐diphenylethylenediamine and trans‐9,10‐dihydro‐9,10‐ethanoanthracene‐(11S,12S)‐11,12‐dicarboxylic acid CSPs). Normal‐, reversed‐phase and polar‐organic separation modes were employed. The effect of the mobile phase composition was examined. The enantiomeric separation of binaphthyl derivatives, which possess quite similar structures, was possible in different enantioselective environments. The substituents and their positions on the binaphthyl skeleton affect their properties and, as a consequence, the separation system suitable for their enantioseparation. In general, the presence of ionizable groups on the binaphthyl skeleton, substitution with non‐identical groups and a chiral axis in the 1,2′ position had the greatest impact on the enantiomeric discrimination. The 8,3′‐disubstituted 1,2′‐binaphthyl derivatives were the most easily separated compounds in several separation systems. From all the chiral stationary phases tested, cellulose‐based columns were shown to be the most convenient for enantioseparation of the studied analytes. However, the polymeric CSPs with their complementary behavior provided good enantioselective environments for some derivatives that could be hardly separated in any other chromatographic system. 相似文献