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981.
Rinaldo M. Colombo Francesca Marcellini 《Mathematical Methods in the Applied Sciences》2015,38(7):1292-1302
We present a traffic flow model consisting of a gluing between the Lighthill–Whitham and Richards macroscopic model with a first‐order microscopic following the leader model. The basic analytical properties of this model are investigated. Existence and uniqueness are proved, as well as the basic estimates on the dependence of solutions from the initial data. Moreover, numerical integrations show some qualitative features of the model, in particular the transfer of information among regions where the different models are used. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
982.
Silvia Sternativo Benedetta BattistelliLuana Bagnoli Claudio SantiLorenzo Testaferri Francesca Marini 《Tetrahedron letters》2013
A novel, simple, and flexible approach to α,α-disubstituted γ-lactams via a domino Michael addition/cyclization process involving the phenyl vinyl selenone and β-ketoamides, malonylamides, or β-cyanoamides is reported. The reactions proceed in good to excellent yields under mild reaction conditions. 相似文献
983.
984.
Ligia Maria Moretto Francesca Montagner Renzo Ganzerla Paolo Ugo 《Analytical and bioanalytical chemistry》2013,405(11):3603-3610
Voltammetry of microparticles is applied to characterise and to identify solid analytes of interest in the field of cultural heritage. Nafion® is used for the immobilisation of solid microparticles onto the surface of a glassy carbon electrode by exploiting the deposition onto the electrode surface of a micro-volume of a suspension of the microsample in polymeric solution. Cyclic voltammetry and square wave voltammetry are applied to characterise and to identify the microparticles immobilised in the Nafion® coating. The analyte studied in this work is Prussian Blue as a typical inorganic pigment, with a relatively simple electrochemical behaviour. The proposed method is applied to a sample of Venetian marmorino plaster. The performance of Nafion® for this analysis is compared with that of the polymer Paraloid B72. Figure
From sampling the pigment in the work of art to recording the voltammetric signal with Nafion coated electrodes 相似文献
985.
Dr. Martina Torelli Prof. Francesca Terenziani Dr. Alessandro Pedrini Dr. Francesca Guagnini Dr. Ilaria Domenichelli Prof. Chiara Massera Prof. Enrico Dalcanale 《ChemistryOpen》2020,9(2):261-268
The eligibility of tetraquinoxaline cavitands (QxCav) as molecular grippers relies on their unique conformational mobility between a closed (vase) and an open (kite) form, triggered in solution by conventional stimuli like pH, temperature and ion concentration. In the present paper, the mechanochemical conformational switching of ad hoc functionalized QxCav covalently embedded in an elastomeric polydimethylsiloxane and in a more rigid polyurethane matrix is investigated. The rigid polymer matrix is more effective in converting mechanical force into a conformational switch at the molecular level, provided that all four quinoxaline wings are covalently connected to the polymer. 相似文献
986.
Francesca Munari Carlo G. Barracchia Cinzia Franchin Francesca Parolini Stefano Capaldi Alessandro Romeo Luigi Bubacco Michael Assfalg Giorgio Arrigoni Mariapina D'Onofrio 《Angewandte Chemie (International ed. in English)》2020,59(16):6607-6611
In the brain of individuals with Alzheimer's disease, the regulatory protein ubiquitin is found conjugated to different lysine residues of tau protein assembled into pathological paired helical filaments. To shed light on the hitherto unexplored ubiquitination‐linked conformational transitions of tau, the availability of in vitro ubiquitin conjugation methods is of primary importance. In our work, we focused on the four‐repeat domain of tau and assembled an enzymatic machinery formed by UBE1, Ubc13, and CHIP enzymes. The enzymatic reaction resulted in monoubiquitination at multiple sites, reminiscent of the ubiquitination pattern observed in vivo. We further exploited chemoselective disulfide coupling reactions to construct three tau regioisomers with site‐specific monoubiquitination. Protein aggregation experiments revealed that the multiple enzyme‐derived products were unable to convert into amyloid fibrils, while the semisynthetic conjugates exhibited diverse capability to form filaments. This study contributes novel insight into the effects of a key post‐translational modification on aberrant protein self‐assembly. 相似文献
987.
Novel carbon nanotube composites by grafting reaction with water-compatible redox initiator system 总被引:1,自引:0,他引:1
Giuseppe Cirillo Tommaso Caruso Silke Hampel Diana Haase Francesco Puoci Manfred Ritschel Albrecht Leonhardt Manuela Curcio Francesca Iemma Vyacheslav Khavrus Mandy Grobosch Nevio Picci 《Colloid and polymer science》2013,291(3):699-708
Multi-walled carbon nanotubes were chemically functionalized with methacrylic acid and methacrylated bovine serum albumin by free radical grafting reaction to obtain novel nanocomposites. The nanotubes were synthesized by aerosol-assisted chemical vapor deposition, and then the monomers were directly grafted by the action of hydrogen peroxide/ascorbic acid redox pair which allows operating in water-compatible and eco-friendly environment without the generation of any toxic reaction by-product. A multi-technique approach was used to evaluate the effectiveness of the grafting process employing Fourier transform infrared, Raman, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, and thermogravimetric analyses. Considering the high importance of methacrylate polymers and bovine serum albumin, the proposed nanocomposites could be of great applicability in biomedical and pharmaceutical fields. 相似文献
988.
Francesca Serra 《Liquid crystals》2016,43(13-15):1920-1936
ABSTRACTThe use of nematic liquid crystals for directed assembly of particles and for the creation of multistable systems depends on the ability to control the topological defects and the distortions of the director field. These are not only driven by topological constraints and by anchoring energies but also by the curvature field created by the bounding surfaces. This review explores the interaction between defects, topology, inclusions and curvature in nematics. I will introduce the relationship between curvature and the Frank elastic energy in nematics, and then I will give an overview of specific examples that show how this coupling can create unexpected behaviours, such as lock-and-key interactions, anchoring transitions on curved surfaces and memory effects. 相似文献
989.
Marcello Tiecco Lorenzo Testaferri Andrea Temperini Francesca Marini Luana Bagnoli Claudio Santi 《合成通讯》2013,43(10):1773-1778
A regiospecific and stereospecific conversion of cinnamyl methyl ether and cinnamyl acetate into the corresponding oxazolines can be easily effected by reaction with diphenyl diselenide and ammonium persulfate, in benzonitrile in the presence of acetic acid. 相似文献
990.
Dr. Christian M. Heckmann Prof. Francesca Paradisi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(67):16616-16620
The combination of biocatalysis and chemocatalysis can be more powerful than either technique alone. However, combining the two is challenging due to typically very different reaction conditions. Herein, chiral N-aryl amines, key features of many active pharmaceutical ingredients, are accessed in excellent enantioselectivity (typically>99.5 % ee) by combining transaminases with the Buchwald-Hartwig amination. By employing a bi-phasic buffer-toluene system as well as the ligand GPhos, the telescoped cascade proceeded with up to 89 % overall conversion in the presence of excess alanine. No coupling to alanine was observed. 相似文献