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101.
The reaction of 3-alkynyl-4-methoxycoumarins with molecular iodine in chlorinated solvents allows access to 3-iodofurochromones in good to excellent yields as the result of a iodocyclization-demethylation process. Competitive diiodination of the coumarin acetylene moiety could be eliminated by simply performing the reactions in refluxing 1,2-dichloroethane, owing to the thermal instability of the resulting (E)-1,2-diiodoethenylcoumarins. 相似文献
102.
Hanane Benzeid Emmanuelle Mothes El Mokhtar Essassi Peter Faller Geneviève Pratviel 《Comptes Rendus Chimie》2012,15(1):79-85
Simple and easy to prepare quinoxaline derivatives proved able to stain amyloid fibers such as aggregated lysozyme and Aβ(1-40)-peptide by a fluorescence “turn on” mechanism. Thienoquinoxaline 1 allowed the detection of lysozyme and Aβ(1-40) fibers at λ = 555 and 532 nm, respectively, with excitation at λ = 450 nm. Styryl-quinoxaline 2 stained lysozyme and Aβ(1-40) fibers with fluorescence at λ = 579 and 567 nm, respectively, upon excitation at λ = 453 nm. The apparent Kd values for Aβ(1-40) fibers were 77 and 294 nM for 1 and 2, respectively. The sensitivity of the aggregates detection assay with these new dyes was higher than that of thioflavin T. Considering their unique fluorescence properties compared to other dyes reported in the field, they can be considered as additional staining tools for the detection and studies of peptide/protein aggregation. 相似文献
103.
Geneviève Barro Benjamin Mampassi Longin Some Jean Marie Ntaganda Ousséni So 《Central European Journal of Mathematics》2006,4(2):260-269
This paper aims at the development of numerical schemes for nonlinear reaction diffusion problems with a convection that blows
up in a finite time. A full discretization of this problem that preserves the blow — up property is presented as well as a
numerical simulation. Efficiency of the method is derived via a numerical comparison with a classical scheme based on the
Runge Kutta scheme. 相似文献
104.
Lerouge F Cerveau G Corriu RJ Stern C Guilard R 《Chemical communications (Cambridge, England)》2007,(15):1553-1555
The use of a magnetic field as a controlling factor during the hydrolysis-polycondensation of porphyrin precursors substituted by Si(OR)(3) groups, induces a self-organization of porphyrin moieties due to the stacking of these units in the hybrid material and this study also confirms the effect of the magnetic field in the nano- and micrometric organization during the kinetically controlled polycondensation process. 相似文献
105.
Angelov B Angelova A Garamus VM Lebas G Lesieur S Ollivon M Funari SS Willumeit R Couvreur P 《Journal of the American Chemical Society》2007,129(44):13474-13479
The structural evolution of a diamond-type bicontinuous lipid cubic phase upon application of thermal and chemical (hydration agent) stimuli is investigated by means of small-angle neutron (SANS) and X-ray scattering (SAXS). The soft-matter cubic architecture responds by dramatic swelling (DLarge cubic structure) upon incorporation of a hydration-enhancing guest component (octyl glucoside) at low and ambient temperatures, the aqueous channel diameter increasing twice to approximately 7 nm. DLarge appears to be built up from an assembly of cubosomic domains, which may coexist with an amphiphilic lamellae domain at low temperatures. The chemical stimulus concentration can be selected as to tune the hydration of the nanochannels in the DLarge phase and its transformation into a DNormal phase at temperatures above the body temperature. Two-dimensional SANS images recorded upon heating scan reveal growth of spontaneously oriented domains of single-crystal cubic nature. Phase separation and squeezing out the guest-hydrating agent from the higher-curvature regions of the amphiphilic bilayer suggest a possible mechanism for the established transformations. The order-order structural transition, cubic DLarge-cubic DNormal, is found to be reversible upon cooling. The obtained results put forward a structure-based concept for release of encapsulated guest molecules from stimuli-responsive and self-regulated cubosomic nanocarriers. 相似文献
106.
For a smooth, bounded domain R, n 3, and a real, positive parameter, we consider the hyperbolic equationu
tt
+u
t
–u=–f(u) –g in with Dirichlet boundary conditions. Under certain conditions onf, this equation has a global attractorA
inH
0
1
() ×L
2(). For=0, the parabolic equation also has a global attractor which can be naturally embedded into a compact setA
0 inH
0
1
() ×L
2(). If all of the equilibrium points of the parabolic equation are hyperbolic, it is shown that the setsA
are lower semicontinuous at=0. Moreover, we give an estimate of the symmetric distance betweenA
0 andA
. 相似文献
107.
Dr. Artem Kovalenko Dr. Prasad Polavarapu Dr. Jean‐Louis Gallani Dr. Geneviève Pourroy Dr. Gilles Waton Dr. Marie Pierre Krafft 《Chemphyschem》2014,15(12):2440-2444
We show that water‐soluble monosodic salts of F‐alkyl phosphates CnF2n+1(CH2)2OP(O)(OH)2, with n=8 and 10 (F8H2Phos and F10H2Phos) form Gibbs films with exceptionally high dilational viscoelastic modules E that reach ~900 mN m?1 in the condensed phases. These E values are up to one order of magnitude larger than those recorded for phospholipid, protein and polymer films commonly considered as highly viscoelastic. F8H2Phos.1Na undergoes a transition between a liquid‐expanded and a liquid‐condensed phase. In the case of F10H2Phos.1Na, a transition occurs between a gas phase of surface domains, in which the molecules are densely packed, and a liquid‐condensed phase. 相似文献
108.
New Trimethoxybenzamides and Trimethoxyphenylureas Derived from Dimethylcarbazole as Cytotoxic Agents. Part I 下载免费PDF全文
Antonella Panno Maria Stefania Sinicropi Anna Caruso Hussein El‐Kashef Jean‐Charles Lancelot Geneviève Aubert Aurélien Lesnard Thierry Cresteil Sylvain Rault 《Journal of heterocyclic chemistry》2014,51(Z1):E294-E302
A convenient synthesis of novel functionalized 1,4‐dimethylcarbazole derivatives containing 3,4,5‐trimethoxybenzamido‐ureido or N‐(3,4,5‐trimethoxyphenyl)ureido group starting from their corresponding indole derivatives is reported. Three derivatives prepared ( 5g , 6c , and 6g ) were active against leukemia cell lines HL60. Both 5g and 6g showed potent antiproliferative activity against KB cell lines, likely associated with the inhibition of tubulin polymerization. 相似文献
109.
Yousoon Lee Forrest T. Sloane Dr. Geneviève Blondin Dr. Khalil A. Abboud Dr. Ricardo García‐Serres Prof. Dr. Leslie J. Murray 《Angewandte Chemie (International ed. in English)》2015,54(5):1499-1503
Reaction of a trinuclear iron(II) complex, Fe3Br3 L ( 1 ), with KC8 under N2 leads to dinitrogen activation products ( 2 ) from which Fe3(NH)3 L ( 2‐1 ; L is a cyclophane bridged by three β‐diketiminate arms) was characterized by X‐ray crystallography. 1H NMR spectra of the protonolysis product of 2 synthesized under 14N2 and 15N2 confirm atmospheric N2 reduction, and ammonia is detected by the indophenol assay (yield ~30 %). IR and Mössbauer spectroscopy, and elemental analysis on 2 and 2‐1 as well as the tri(amido)triiron(II) 3 and tri(methoxo)triiron 4 congeners support our assignment of the reduction product as containing protonated N‐atom bridges. 相似文献
110.
Delphine Gallois-Montbrun Nicolas Thiebault Vincent Moreau Geneviève Le Bas Jean-Christophe Archambault Sylviane Lesieur Florence Djedaïni-Pilard 《Journal of inclusion phenomena and macrocyclic chemistry》2007,57(1-4):131-135
A novel amphiphilic cyclodextrin derivative was obtained by controlled esterification of lauric acid chloride on the primary
face of the native β-cyclodextrin in a one step synthesis. The characterization of the substitution degree and isomer structure
was performed by mass and NMR spectroscopies. A specific purification procedure by sublimation was developed in order to eliminate
the excess of lauric acid molecules in the reaction product. The sublimation efficiency was assessed by differential scanning
calorimetry (DSC) in quantifying the remaining fatty acid. In this way the duration of the sublimation process could be optimized. 相似文献