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351.
Rosini G Borzatta V Boschi F Candido G Marotta E Righi P 《Chemical communications (Cambridge, England)》2007,(26):2717-2719
The occurrence of p(1),n(1) salt when accompanied by substrate self-association can have profound effects on enantiomer separation processes of non-racemic mixtures, impeding the complete recovery of the major enantiomer through formation of an inescapable racemate cage. 相似文献
352.
The problem of closing the detection loophole with asymmetric systems, such as entangled atom-photon pairs, is addressed. We show that, for the Bell inequality I3322, a minimal detection efficiency of 43% can be tolerated for one of the particles, if the other one is always detected. We also study the influence of noise and discuss the prospects of experimental implementation. 相似文献
353.
Trans (1R,2R)-diaminocyclohexane was used as a semirigid vicinal diamine to anchor two N-protected tripeptides consisting of L-D-L amino acids as carboxy terminal amides. The bis-tripeptide consisting of L-Ser (OBn)-D-Ser (OBn)-L-Ser (O-p-bromobenzyl) Boc afforded X-ray quality crystals containing benzene and chloroform solvent molecules. Analysis of the solid-state structure revealed a highly H-bonded helical open-ended tubular superstructure. The tripeptide strands intertwine like a pair of self-embracing arms, held together by a gamma-turn and a 14-membered antiparallel H-bonded macroring spanning the first and third amino acid residues within each strand. Whereas the tripeptide from the R,R anchor gave beautiful crystals from benzene and chloroform, the analogous construct from the S,S-anchored diamine gave a gel. Related bis-tripeptides with different amino acids showed extensive intramolecular H-bonding based on NMR titration and dilution experiments. 相似文献
354.
Short alpha/beta-peptides, containing conformationally restricted cis-beta-aminocyclopropylcarboxylic acid units as turn-inducing elements, have been found to be efficient catalysts for inter- and intramolecular aldol reactions. The tripeptide H-(L)-Pro-black triangle-(L)-Pro-OH was identified to perform especially well in homogeneous and heterogeneous aqueous solutions as well as in organic solvents. 相似文献
355.
Dr. Javier F. Reynes Dr. Valerio Isoni Dr. Felipe García 《Angewandte Chemie (International ed. in English)》2023,62(44):e202300819
Mechanochemistry provides an environmentally benign platform to develop more sustainable chemical processes by limiting raw materials, energy use, and waste generation while using physically smaller equipment. A continuously growing research community has steadily showcased examples of beneficial mechanochemistry applications at both the laboratory and the preparative scale. In contrast to solution-based chemistry, mechanochemical processes have not yet been standardized, and thus scaling up is still a nascent discipline. The purpose of this Minireview is to highlight similarities, differences and challenges of the various approaches that have been successfully applied for a range of chemical applications at various scales. We hope to provide a discussion starting point for those interested in further developing mechanochemical processes for commercial use and/or industrialisation. 相似文献
356.
Riccardo De Marco Valerio Giuso Dr. Thierry Achard Dr. Marzio Rancan Dr. Marco Baron Prof. Dr. Lidia Armelao Dr. Matteo Mauro Dr. Stéphane Bellemin-Laponnaz Prof. Dr. Cristina Tubaro 《欧洲无机化学杂志》2023,26(23):e202300184
Gold(I) complexes with N-heterocyclic carbene ligands functionalized with a pendant phosphonium moiety were synthesized by simple procedures. In particular, the simple addition of LiBr salt in the reaction media allows the formation of the NHC gold(I) mononuclear complexes, whilst in the absence of excess bromide ions the deprotonation of the methylene group in alpha position to the phosphonium group occurs, allowing the isolation of the dinuclear complexes with two C,C-bridging NHC-phosphonium ylide ligands. The complexes were characterized in solution with NMR spectroscopy and ESI-MS spectrometry, as well as in the solid state by means of single crystal X-ray diffraction analysis. Mononuclear gold(III) species were also isolated by Br2 oxidative addition to the mononuclear gold(I) species and fully characterized. Preliminary results of the biological effects on MCF7 cancer cells are also reported. 相似文献
357.
In this article we characterize a certain class of rational solutions of the hierarchy of master symmetries for KdV. The result
is that the generic rational potentials that decay at infinity and remain rational by all the flows of the master-symmetry
KdV hierarchy are bispectral potentials for the Schr?dinger operator. By bispectral potentials we mean that the corresponding
Schr?dinger operators possess families of eigenfunctions that are also eigenfunctions of a differential operator in the spectral
variable. This complements certain results of Airault–McKean–Moser [4], Duistermaat–Grünbaum [10], and Magri–Zubelli [40].
As a consequence of bispectrality, the rational solutions of the master symmetries turn out to be solutions of a (generalized)
string equation.
Received: 28 January 1999 / Accepted: 22 October 1999 相似文献
358.
359.
Valerio Grazioso Carlo Scalo Giuseppe de Felice & Carlo Meola 《advances in applied mathematics and mechanics.》2011,3(3):370-388
In this work we introduce PRIN-3D (PRoto-code for Internal
flows modeled by Navier-Stokes equations in 3-Dimensions),
a new high level algebraic language (Matlab$^®$) based code, by discussing some fundamental aspects regarding its basic solving kernel and by describing the design of an innovative advection scheme. The main focus was on
designing a memory and computationally efficient code that, due to the typical
conciseness of the Matlab coding language, could allow for fast and effective implementation of new models or algorithms. Innovative numerical methods are discussed in the paper. The pressure equation
is derived with a quasi-segregation technique leading to an iterative scheme obtained within the framework of a global preconditioning procedure. Different levels of parallelization are obtainable by exploiting special
pressure variable ordering patterns that lead to a block-structured Poisson-like
matrix. Moreover, the new advection scheme has the potential of a controllable artificial diffusivity. Preliminary results are shown including a fully three-dimensional internal
laminar flow evolving in a relatively complex geometry and a 3D methane-air flame simulated with the aid of libraries based on the Flamelet model. 相似文献
360.
Serum protein profiles of patients with pancreatic cancer and chronic pancreatitis: searching for a diagnostic protein pattern. 总被引:2,自引:0,他引:2
A Valerio D Basso S Mazza G Baldo A Tiengo S Pedrazzoli R Seraglia M Plebani 《Rapid communications in mass spectrometry : RCM》2001,15(24):2420-2425
In this study, 13 sera from patients with pancreatic cancer, 9 from chronic pancreatitis and 10 from healthy subjects were analyzed by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. The MALDI mass spectra revealed the presence of several low molecular weight peptides, among which some were detected only in the sera from both pathological conditions. On the other hand many peptides were observed only in control sera, and were absent in the sera from the two diseases. Therefore, MALDI analysis of the low molecular weight fraction (<10 000 Da) of sera from patients with pancreatic diseases enabled us to identify the presence of some disease-related signals and also some signals characteristic of normal subjects. 相似文献