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51.
We report the synthesis and first characterization of N-alkyldiaminoresorcinols (or 4,6-bis-dialkylaminobenzene-1,3-diols C6H2(NHR)2(OH)2) (10a, R = CH2-2-Py; 10b, R = CH2-3-Py; 10c, R = CH2-4-Py) which result from one-pot stepwise reactions: (i) air-oxidation of diaminoresorcinol 3, (ii) transamination reaction leading to the corresponding functional 6π+6π quinonemonoimine zwitterions C6H2(NHR)2(O)2 (9a, R = CH2-2-Py; 9b, R = CH2-3-Py; 9c, R = CH2-4-Py), (iii) reduction and re-aromatization in the presence of the corresponding primary amine bearing a pyridine moiety. 相似文献
52.
Philipp Wopperer Umberto De Giovannini Angel Rubio 《The European Physical Journal B - Condensed Matter and Complex Systems》2017,90(3):51
We derive and extend the time-dependent surface-flux method introduced in [L. Tao, A. Scrinzi, New J. Phys. 14, 013021 (2012)] within a time-dependent density-functional theory (TDDFT) formalism and use it to calculate photoelectron spectra and angular distributions of atoms and molecules when excited by laser pulses. We present other, existing computational TDDFT methods that are suitable for the calculation of electron emission in compact spatial regions, and compare their results. We illustrate the performance of the new method by simulating strong-field ionization of C60 fullerene and discuss final state effects in the orbital reconstruction of planar organic molecules. 相似文献
53.
Luisa Silva Thierry Coupez Hugues Digonnet 《International Journal of Computational Fluid Dynamics》2016,30(6):431-436
ABSTRACTIn this paper, a work performed to allow massively parallel finite element flow computations is presented. It includes the development and optimisation of two particular features of a finite element multiphase computational fluid dynamics software, which are mesh generation and linear system solution, using anisotropic adaptation and multigrid preconditioning. Parallel performances on supercomputers are shown, where the largest generated mesh (on 65 536 Intel Xeon or 261 144 Power PC cores) had 33.4 billions of nodes, leading to a 100 billion of unknowns linear system solution. Final applications concern, between others, image-based flow simulations. 相似文献
54.
Nostro A Filocamo A Giovannini A Catania S Costa C Marino A Bisignano G 《Natural product research》2012,26(22):2132-2136
This study reported the antimicrobial activity and phenolic content of natural site and micropropagated Limonium avei (De Not.) Brullo & Erben inflorescences. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of ethanolic extracts were determined according to the Clinical Laboratory Standards Institute guidelines. Individual phenolic acids and flavonoids were detected by a high performance liquid chromatography (HPLC-DAD) method. The samples showed a comparable antimicrobial activity, although the natural site extract possessed the lower MIC values. The best activity was detected against Gram-positive bacteria, such as Staphylococcus aureus including methicillin resistant strains (MIC and MBC values ranging from 7.81 to 62.50?μg?mL(-1) and from 500 to 2000?μg?mL(-1) respectively). In contrast, a low activity was found on Gram-negative bacteria and Candida albicans. The HPLC-DAD analysis revealed ten phenolic acids and four flavonoids with a major amount of m-coumaric acid, naringin and quercetin in the natural site extract. 相似文献
55.
Dr. Mariusz Tasior Vincent Hugues Dr. Mireille Blanchard‐Desce Prof. Daniel T. Gryko 《化学:亚洲杂志》2012,7(11):2656-2661
New, strongly fluorescent benzo[1,2‐d:4,5‐d′]bisimidazoles have been prepared by the reaction of Bandrowski′s base with various aldehydes. Their structures were carefully designed to achieve efficient excited‐state intramolecular proton transfer and good two‐photon‐absorption (2PA) cross‐sections. Functional dyes that possessed both high fluorescence quantum yields and large Stokes shifts were prepared. A π‐expanded D‐A‐D derivative that possessed Φfl=50 % and σ2=230 GM in the spectroscopic area of interest for biological imaging is an excellent candidate as a fluorescent probe. Thanks to the presence of two reactive amino groups, such compounds can be easily transformed into probes for bioconjugation. All of these benzo[1,2‐d:4,5‐d′]bisimidazoles were also strongly fluorescent in the solid state. 相似文献
56.
57.
Vronique Rouchon Hugues Badet Oulfa Belhadj Olivier Bonnerot Bertrand Lavdrine Jean‐Guy Michard Serge Miska 《Journal of Raman spectroscopy : JRS》2012,43(9):1265-1274
Fossil materials that contain iron sulfide are well known for their instability when exposed to oxygen and humidity. This term however combines a great variety of materials showing different types of damages. Most of them consist of crystal efflorescence appearing on the surface and inside the matrix. In this work, a methodology was determined for the analysis of these damages by the use of Raman and infrared spectroscopy. The infrared and Raman signatures of a large set of iron sulfates were characterized. Specific attention was paid to sideronatrite and ferrinatrite, which are two associated sodium/iron(III) sulfates, and their infrared and Raman bands were partially assigned. Analysis performed on a selection of 11 damaged fossils showed a great variety of degradation products: besides one case that appeared to be a synthetic resin close to polyvinylchloride acetate, which was applied with a brush on the fossil surface, all degradation products belong to the sulfate group. However, many iron‐free sulfates, such as gypsum, halotrichite, epsomite, or pentahydrite were found, often in association with iron sulfates. In one case, despite the presence of iron in the matrix, no iron sulfate could be detected. This shows that the term ‘pyritic fossil’, commonly used by collection managers, is not appropriate as it oversimplifies the reality. A name such as ‘sulfide‐containing fossil’ would be more suitable. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
58.
Tomographic diffractive microscopy with a wavefront sensor 总被引:1,自引:0,他引:1
Ruan Y Bon P Mudry E Maire G Chaumet PC Giovannini H Belkebir K Talneau A Wattellier B Monneret S Sentenac A 《Optics letters》2012,37(10):1631-1633
Tomographic diffractive microscopy is a recent imaging technique that reconstructs quantitatively the three-dimensional permittivity map of a sample with a resolution better than that of conventional wide-field microscopy. Its main drawbacks lie in the complexity of the setup and in the slowness of the image recording as both the amplitude and the phase of the field scattered by the sample need to be measured for hundreds of successive illumination angles. In this Letter, we show that, using a wavefront sensor, tomographic diffractive microscopy can be implemented easily on a conventional microscope. Moreover, the number of illuminations can be dramatically decreased if a constrained reconstruction algorithm is used to recover the sample map of permittivity. 相似文献
59.
Yahia Didane Rocio Ponce Ortiz Jian Zhang Keijyu Aosawa Toshinori Tanisawa Hecham Aboubakr Frédéric Fages Jörg Ackermann Noriyuki Yoshimoto Hugues Brisset Christine Videlot-Ackermann 《Tetrahedron》2012,68(24):4664-4671
Solution and solid-state properties of two new perfluoroalkyl end-substituted analogues of distyryl-bithiophene (CF3-DS2T and diCF3-DS2T) are presented. Vacuum deposited thin films were investigated by atomic force microscopy, X-ray diffraction, and implemented as active layers into organic thin film transistors. While physicochemical measurements in solution suggest a preferential hole injection and transport inside CF3-DS2T and diCF3-DS2T films, electrical measurements performed under high vacuum show that CF3-DS2T behaves as n-type semiconductor while no charge transport was measured in diCF3-DS2T. The results highlighted the importance of substituents on conjugated backbone and on the resulting fine ordering in solid state to control the charge transport. 相似文献
60.
Connell BJ Baleux F Coic YM Clayette P Bonnaffé D Lortat-Jacob H 《Chemistry & biology》2012,19(1):131-139
The HIV-1 envelope gp120, which features both the virus receptor (CD4) and coreceptor (CCR5/CXCR4) binding sites, offers multiple sites for therapeutic intervention. However, the latter becomes exposed, thus vulnerable to inhibition, only transiently when the virus has already bound cellular CD4. To pierce this defense mechanism, we engineered a series of heparan sulfate mimicking tridecapeptides and showed that one of them target the gp120 coreceptor binding site with μM affinity. Covalently linked to a CD4-mimetic that binds to gp120 and renders the coreceptor binding domain available to be targeted, the conjugated tridecapeptide now displays nanomolar affinity for its target. Using solubilized coreceptors captured on top of sensorchip we show that it inhibits gp120 binding to both CCR5 and CXCR4 and in peripheral blood mononuclear cells broadly inhibits HIV-1 replication with an IC(50) of 1 nM. 相似文献