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161.
B Gerland A Goudot G Pourceau A Meyer S Vidal E Souteyrand JJ Vasseur Y Chevolot F Morvan 《The Journal of organic chemistry》2012,77(17):7620-7626
Homo- and heterofunctionalized glycoclusters with galactose and/or fucose residues targeting both PA-IL and PA-IIL lectins of Pseudomonas aeruginosa were synthesized using "Click" chemistry and DNA chemistry. Their binding to lectins (separately or in a mixture) was studied using a DNA Directed Immobilization carbohydrate microarray. Homoglycoclusters bind selectively to their lectin while the heteroglycocluster binds simultaneously both lectins with a slight lower affinity. 相似文献
162.
Valle MS Saraiva MF Retailleau P de Almeida MV Dodd RH 《The Journal of organic chemistry》2012,77(13):5592-5599
4-Hydroxymethylbutenolide 4 was transformed into its sulfamoyl derivative 5, which upon treatment with iodosobenzene diacetate and magnesium oxide in the presence of a rhodium catalyst afforded the product of intramolecular aziridination 6. Reaction of 6 with primary or secondary amines in DMA led to regioselective opening of the aziridine ring at C2 to give the corresponding bicyclic derivatives 7a-7g in good to excellent yields. Methanolysis of the lactone ring of the N-benzyl-N-methyl derivative 7c followed by protection of the resulting secondary hydroxy group and treatment of the product with Boc anhydride provided the activated cyclic sulfamates 13 and 14. The latter then reacted with a second nucleophile (azide or thiophenol) to give the corresponding difunctionalized α,β-diamino methyl esters 15-18, 20. 相似文献
163.
The cationic halochromism of phenolate betaines was reproduced with the aid of a simple theoretical model, by calculation of the longest wavelength transition energies of supermolecules obtained by positioning a cation Mn+ at a variable distance from the oxygen atom of the dye. The theoretical results were compared with experimental data for three systems, Reichardt’s betaine 1, Brooker’s merocyanine 2 and the N-methyl-8-oxyquinolinium dye 3. The model was validated by molecular dynamics simulations of solutions of dye 3, in methanol and DMSO, in the presence of variable concentrations of Na+. 相似文献
164.
B. N. Sismanoglu K. G. Grigorov R. Caetano M. V.O. Rezende Y. D. Hoyer 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2010,60(3):505-516
This paper is dedicated to the study of the electrical and optical
characteristics of direct current microhollow cathode discharges (MHCD) in
argon flow. Experiments have been carried out in order to determine the
so-called Paschen’s curves in a static open MHCD. Current-voltage
characteristics were obtained as a function of the pressure and hole
diameter. MHCD enable stable direct current discharge operation, which could
be ignited for pressures ranging from 12 to 800 Torr, in a very wide range of
current densities and electrodes materials. Optical emission spectroscopy
and analysis of the spectral line broadening of plasma line emissions were
performed in order to measure parameters such as electron number density (2–4 × 1014 cm-3)^{-3}), gas
temperature (460–640 K), excitation
temperature (~ 7000 K) and electron temperature (~ 8500 K), for
current ranging from 7 to 15 mA. Lower gas temperature was measured compared
to the static MHCD ones. 相似文献
165.
Eliane Gonçalves de Araújo Nedja Suely Fernandes Lilian Grace da Silva Solon Cícero Flavio Soares Aragão Carlos A. Martinez‐Huitle 《Electroanalysis》2015,27(2):398-405
A simple differential pulse voltammetric method based on a graphite paste electrode (GPE) was developed for the quantitative determination of folic acid (FA) in tablets. The electrode exhibits a clear improvement of the current response. A linear response in the electroanalytical approach exists from 4.97×10?6 to 2.94×10?5 mol L?1 with a limit of detection of about 2.67×10?6 mol L?1 in KCl solutions. The developed procedure was tested by recovery studies and compared with spectrophotometric and chromatographic methods. The results are described and discussed in the light of existing literature. 相似文献
166.
Response surface methodology (RSM) as a tool for optimization in analytical chemistry 总被引:19,自引:0,他引:19
A review about the application of response surface methodology (RSM) in the optimization of analytical methods is presented. The theoretical principles of RSM and steps for its application are described to introduce readers to this multivariate statistical technique. Symmetrical experimental designs (three-level factorial, Box-Behnken, central composite, and Doehlert designs) are compared in terms of characteristics and efficiency. Furthermore, recent references of their uses in analytical chemistry are presented. Multiple response optimization applying desirability functions in RSM and the use of artificial neural networks for modeling are also discussed. 相似文献
167.
Tânia Maria Monteiro Janaína Marques Rodrigues Eliane Cristina Pires do Rego Werickson Fortunato de Carvalho Rocha Juliana Swensson de Mattos Fernanda Figueiredo Nunes Valnei Smarçaro da Cunha Marcus Henrique Campino de la Cruz Vanderléa de Souza 《Accreditation and quality assurance》2013,18(3):197-206
Cachaça is the typical and genuine denomination for the sugar cane beverage produced in Brazil. It has an alcoholic content between 38 and 48 % by volume, at 20 °C, and is obtained from the distillation of fermented sugar cane juice with the possible addition of up to 6 g/L of sugar, expressed by sucrose. This paper aims to outline the approach taken for the certification of the mass fraction of individual alcohols and their associated uncertainties in a cachaça certified reference material (CRM) produced by the Organic Analysis Laboratory of the Chemical Metrology Division of Inmetro. The requirements of ISO Guide 31, ISO Guide 34 and ISO Guide 35 were followed for the certification. This included the assessment of the degree of homogeneity of the material, the short-term stability study to determine the transport conditions, the long-term stability study to establish the shelf life and storage conditions of the CRM and the characterization process. The certified values were determined by two analytical techniques: gas chromatography coupled to mass spectrometry and gas chromatography with flame ionization detection. In order to support the routine testing of cachaça, in helping analytical laboratories validate and standardize their methods, the certified reference material (CRM 02.1/10.003b) was developed and certified for the mass fractions of methanol (9.18 mg/100 g ± 0.82 mg/100 g), 2-butanol (4.15 mg/100 g ± 0.40 mg/100 g), 1-butanol (1.30 mg/100 g ± 0.18 mg/100 g), isobutanol (24.0 mg/100 g ± 1.0 mg/100 g) and 1-propanol (29.4 mg/100 g ± 1.3 mg/100 g) in a spiked cachaça. 相似文献
168.
Puspitapallab?ChaudhuriEmail author H.?O.?Frota Cicero?Mota Angsula?Ghosh 《Journal of nanoparticle research》2018,20(6):158
We report theoretical analysis of charge transport process through a single glycine molecule utilizing graphene nanogaps. Density functional theory and non-equilibrium Green’s function method are employed to investigate the transport properties of glycine inside the gap. The projected density of states, transmittance, and the current–voltage characteristics are determined with changes in the molecular orientation inside the nanogap of c.a 0.8 nm. The current values demonstrate a high sensitivity on the orientation of the molecule. The conductance of the molecule is also dependent on the voltage. 相似文献
169.
A new dual (fluorescent and spin) probe is described, where a N-aryl-2,4,6-triphenylpyridinium fluorophore is attached to a TEMPO fragment through an amide link. The resulting sensor 4 was evaluated as a hydrogen-abstracting agent in acetonitrile and in an aqueous solution of reduced Triton-X 100, being as resistant to hydrolysis as quinoline-TEMPO 1, but more hydrophobic than this probe. 相似文献
170.
Besançon Manon Wang Yanhui Ylla Noëllie Cinquin Valentin Mutin Hubert Alauzun Johan Espuche Eliane Bounor-Legaré Véronique 《Journal of Sol-Gel Science and Technology》2021,99(1):39-54
Journal of Sol-Gel Science and Technology - An original way to synthesise polypropylene/titanium dioxide (PP/TiO2) composites combining non-hydrolytic sol–gel chemistry and reactive extrusion... 相似文献