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Rita Traversi Silvia Becagli Emiliano Castellano Ombretta Largiuni Alessio Migliori Mirko Severi 《International journal of environmental analytical chemistry》2013,93(6-7):457-470
The chemical analysis of shallow firn cores sampled in coastal and plateau areas in Northern Victoria Land and along a transect from Talos Dome to Dome C (East Antarctica, Pacific Ocean sector) allowed a global view of spatial and temporal changes in chemical composition of snow depositions over the last 100 years. Variations in concentration of primary (sea spray) and secondary (biogenic emission, atmospheric inputs) source markers were observed and discussed as a function of distance from the sea and altitude. In the stations characterized by relatively high snow accumulation rates, the sub-sampling resolution was sufficient to obtain a stratigraphic dating by using the periodical variations of seasonal markers. In these stations, a subdivision in “summer” and “winter” samples was carried out in order to study the seasonal changes of the contributions of the measured compounds to the snow composition as elevation and distance from the sea increase. Some evidence of post-depositional effects which are able to change the original deposition of chloride and nitrate, was observed at stations with low accumulation rates. The reliability of the depth/concentration profile of these substances for reconstructing past deposition was also discussed. 相似文献
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A Semisynthetic Approach to New Immunoadjuvant Candidates: Site‐Selective Chemical Manipulation of Escherichia coli Monophosphoryl Lipid A 下载免费PDF全文
Dr. Daniele D'Alonzo Manuela Cipolletti Giulia Tarantino Marcello Ziaco Dr. Giuseppina Pieretti Prof. Alfonso Iadonisi Prof. Giovanni Palumbo Dr. Alberto Alfano Dr. Mariateresa Giuliano Prof. Mario De Rosa Prof. Chiara Schiraldi Dr. Marcella Cammarota Prof. Michelangelo Parrilli Dr. Emiliano Bedini Prof. Maria M. Corsaro 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(31):11053-11063
A semisynthetic approach to novel lipid A derivatives from Escherichia coli (E. coli) lipid A is reported. This methodology stands as an alternative to common approaches based exclusively on either total synthesis or extraction from bacterial sources. It relies upon the purification of the lipid A fraction from fed‐batch fermentation of E. coli, followed by its structural modification through tailored, site‐selective chemical reactions. In particular, modification of the lipid pattern and functionalization of the phosphate group as well as of the sole primary hydroxyl group were accomplished, highlighting the unusual reactivity of the molecule. Preliminary investigations of the immunostimulating activity of the new semisynthetic lipid A derivatives show that some of them stand out as promising, new immunoadjuvant candidates. 相似文献
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Mauro Panunzio Emiliano Tamanini Yves St‐Denis Fabio Maria Sabbatini Romano Di Fabio Zhining Xia 《合成通讯》2013,43(23):4239-4244
Nitrogen‐containing heterocycles bearing a halogen substituent have been converted to the corresponding amines by a synthetic protocol based on Buchwald methodology assisted by microwaves. 相似文献
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Andrea Bencini Claudia Giorgi Emiliano Romagnoli Carlos Lodeiro André Saint-Maurice 《Supramolecular chemistry》2013,25(2):277-285
Abstract The synthesis of a new cylindrical macrotricyclic ligand (L) based upon two 1,4,7,13-tetramethyl-1,4,7,10,13,16-hexaazacyclooctadecane rings connected via two azobenzene pillars is described. The ligands displays photoelastic properties: light absorption at 366 nm produces trans→cis isomerization of the azobenzene moieties with formation of trans-cis (L E-Z ) and cis-cis (L Z-Z ) isomers. Recovery of the thermodynamically more stable trans-trans (L E-E ) isomer can be obtained by thermal back-isomerization or visible light (430 nm) absorption. The isomeric composition of L solution depends upon pH: for pH < 5.5 the L E-E form is the unique species in solution, while increasing amounts of Z species are formed at increasing pH. The protonation constants of L E-E have been determined in 0.1 mol dm?3 Me4NNO3 solution at 298.1 ± 0.1 K. The protonated species of L form stable inclusion complexes with anionic species such as [Co(CN)6]3?. 相似文献
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Emiliano Manzo Giuliana D’IppolitoDario Pagano Francesco TintoAngelo Fontana 《Tetrahedron letters》2014
Fluorescent galactolipid analogues (1, 1a, and 2) have been synthesized with a pyrene group attached to the amino-terminal of a hexanoyl chain bound to an otherwise normal galactolipid structure. The synthetic lipids are obtained from peracetyl galactose by a general and versatile procedure based on the trichloroacetimidate methodology. The intense violet fluorescence (376 and 395 nm) and good photostability of pyrene make these compounds highly suitable as probes to study galactolipid metabolism. As proof of concept, we report that compound 2 is a valid tool to detect galactolipase activity in enzymatic preparations of potato tubers. 相似文献
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Emiliano Cristiani Maria Cristina Saladino 《Mathematical Methods in the Applied Sciences》2019,42(3):918-934
In this paper, we deal with the analysis of the solutions of traffic flow models at multiple scales in both cases of a single road and road networks. We are especially interested in measuring the distance between traffic states (as they result from the mathematical modeling) and investigating whether these distances are somehow preserved passing from the microscopic to the macroscopic scale. By means of both theoretical and numerical investigations, we show that, on a single road, the notion of Wasserstein distance fully catches the human perception of distance independently of the scale, while in the case of networks it partially loses its nice properties. 相似文献
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Enrico Marchetti Roland Brast Bernard Delabre Rob Donaldson Enrico Fedrigo Christoph Frank Norbert Hubin Johann Kolb Miska Le Louarn Jean-Louis Lizon Sylvain Oberti Fernando Quirs-Pacheco Roland Reiss Joana Santos Sebastien Tordo Elise Vernet Roberto Ragazzoni Carmelo Arcidiacono Paolo Bagnara Andrea Baruffolo Emiliano Diolaiti Jacopo Farinato Matteo Lombini 《Comptes Rendus Physique》2005,6(10):1118-1128
The European Southern Observatory (ESO) together with external research institutes have built a Multi-Conjugate Adaptive Optics (MCAO) Demonstrator (MAD) to perform wide field-of-view adaptive optics correction (2′ in K band). The aim of MAD is to demonstrate the on-sky feasibility of the MCAO technique and to evaluate its critical aspects in the framework of both the 2nd generation instrumentation for the Very Large Telescope (VLT) and the Overwhelmingly Large Telescope (OWL). The MAD module will be installed on the VLT to perform on-sky observations. MAD comprises two deformable mirrors and two different multi-reference wavefront sensors with natural guide stars. In this article we present the MAD design, some aspects of the MAD calibration and the first closed-loop results in the laboratory in Single Conjugated Adaptive Optics (SCAO) and Ground Layer Adaptive Optics (GLAO) configurations. To cite this article: E. Marchetti et al., C. R. Physique 6 (2005). 相似文献