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171.
Alessio Valletta Elisabetta Salvatori Anna Rita Santamaria Marcello Nicoletti Chiara Toniolo Emilia Caboni 《Natural product research》2016,30(22):2514-2522
Vitis vinifera sensitivity to tropospheric ozone (O3) has been evidenced in several studies. In this work, physiological and metabolic effects of O3 on two wine cultivars of V. vinifera (i.e. Maturano and San Giuseppe) have been studied. Moreover, chlorogenic acid (CGA) production, in consideration of its importance in the biosynthetic pathway of polyphenols and as antioxidant, has been investigated. Maturano cultivar resulted more sensitive to O3, as evidenced by the gas exchange reduction at the early stage of treatment, and by the increase in Ci/Ca and the decoupling of net photosynthesis and the stomatal conductance at the end of the treatment. Unexpectedly, O3 did not activate stilbene production. Ozone induced an early CGA decrease, significantly more consistent in cv. Maturano, and an increase after 8 days, more consistent in cv. S. Giuseppe. These results suggest that CGA could be considered a biochemical marker of O3-induced stress in V. vinifera. 相似文献
172.
Andrea Temperini Diego AnnesiLorenzo Testaferri Marcello Tiecco 《Tetrahedron letters》2011,52(25):3179-3182
A simple activation of MOM-, MEM- and SEM-phenyl selenides by iodonium or copper(I) ions in the presence of alcohols to give the corresponding alkoxymethyl ethers is described. 相似文献
173.
A Semisynthetic Approach to New Immunoadjuvant Candidates: Site‐Selective Chemical Manipulation of Escherichia coli Monophosphoryl Lipid A
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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
174.
175.
Marcello Amadeo 《ZDM》2018,50(5):907-920
The purpose of this paper is to use historical textbooks to explore the number line, a mathematical object common to our time, contextualizing its use during its initial development period in the seventeenth century until its current use as in the nineteenth century. Relevant analytic geometry textbooks are explored, mainly from France and from Germany of that time, to understand when and how this notion was used. Additionally, pertinent entries from encyclopedias of that time are used to contrast with what was not sufficiently explained in the aforementioned textbooks, until, finally, we can identify this object as it is currently characterized. I analyze how the negative numbers were used to constitute the number line and survey several number line diagrams, which were sometimes similar, but most often quite different from each other. The intention is to understand the historical contexts that configure the emergence and development of the notion of the number line. 相似文献
176.
Marcello Delitala 《Comptes Rendus Mecanique》2003,331(12):817-822
This paper deals with the design of mathematical frameworks for the modeling of traffic flow phenomena by suitable developments of classical models of the kinetic theory. Various types of evolution equations are deduced, and different mathematical structures are proposed toward conceivable applications. To cite this article: M. Delitala, C. R. Mecanique 331 (2003). 相似文献
177.
Angelo Marcello Tarantino 《Journal of Elasticity》2002,69(1-3):73-97
The homogeneous deformations provided by the equilibrium problem of nonlinear isotropic hyperelastic symmetrically loaded
membranes are analyzed. Besides the universal symmetric solutions, the problem considered, depending on the form of the stored
energy function, may admit asymmetric solutions. For general incompressible materials, the mathematical conditions governing
the global development of these asymmetric solutions are investigated. Explicit expressions for evaluating critical loads
and bifurcation points are derived. Results and basic relations obtained for general isotropic materials are then specialized
for a Valanis–Landel and an Ogden material. For this last case, which is frequently used to model rubberlike materials, a
broad numerical analysis was performed. The more qualitatively interesting branches of asymmetric equilibria are shown and
the influence of the material parameters is discussed. Finally, using the energy criterion a number of considerations are
made on stability.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
178.
The post-critical behavior of a cantilever beam with rectangular cross-section, under simultaneous action of conservative and non-conservative loads, is analyzed. An internally constrained Cosserat rod model is adopted to describe the dynamics of the beam in finite displacement regime. The bifurcation equations for simple buckling (divergence), simple flutter (Hopf) and double-zero (Takens-Bogdanova-Arnold) bifurcations are derived by means of the multiple time scales method. Due to the nilpotent eigenvalue at the double-zero critical point, the evaluation of the generalized Keldysh's eigenfunctions is required. Finally, some numerical results are shown and the bifurcation scenario of the beam is discussed. 相似文献
179.
Maria Flavia Monaco Marcello Sammarra Gregorio Sorrentino 《European Journal of Operational Research》2014
The Ship Stowage Planning Problem is the problem of determining the optimal position of containers to be stowed in a containership. In this paper we address the problem considering the objectives of the terminal management that are mainly related to the yard and transport operations. We propose a Binary Integer Program and a two-step heuristic algorithm. An extensive computational experience shows the efficiency and effectiveness of our approach. A classification scheme for stowage planning problems is also provided. 相似文献
180.
Brena B Puglia C de Simone M Coreno M Tarafder K Feyer V Banerjee R Göthelid E Sanyal B Oppeneer PM Eriksson O 《The Journal of chemical physics》2011,134(7):074312
The electronic structure of iron phthalocyanine (FePc) in the valence region was examined within a joint theoretical-experimental collaboration. Particular emphasis was placed on the determination of the energy position of the Fe 3d levels in proximity of the highest occupied molecular orbital (HOMO). Photoelectron spectroscopy (PES) measurements were performed on FePc in gas phase at several photon energies in the interval between 21 and 150 eV. Significant variations of the relative intensities were observed, indicating a different elemental and atomic orbital composition of the highest lying spectral features. The electronic structure of a single FePc molecule was first computed by quantum chemical calculations by means of density functional theory (DFT). The hybrid Becke 3-parameter, Lee, Yang and Parr (B3LYP) functional and the semilocal 1996 functional of Perdew, Burke and Ernzerhof (PBE) of the generalized gradient approximation (GGA-)type, exchange-correlation functionals were used. The DFT/B3LYP calculations find that the HOMO is a doubly occupied π-type orbital formed by the carbon 2p electrons, and the HOMO-1 is a mixing of carbon 2p and iron 3d electrons. In contrast, the DFT/PBE calculations find an iron 3d contribution in the HOMO. The experimental photoelectron spectra of the valence band taken at different energies were simulated by means of the Gelius model, taking into account the atomic subshell photoionization cross sections. Moreover, calculations of the electronic structure of FePc using the GGA+U method were performed, where the strong correlations of the Fe 3d electronic states were incorporated through the Hubbard model. Through a comparison with our quantum chemical calculations we find that the best agreement with the experimental results is obtained for a U(eff) value of 5 eV. 相似文献