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21.
M.J. Al-Darwich A. Plenevaux C. Lemaire G.D. Fiore L. Christiaens D. Comar A. Luxen 《Journal of fluorine chemistry》1996,80(2):117-124
(S)-4-Chloro-2-fluorophenylalanine and (S)-(α-methy)-4-chloro-2-fluorophenylalanine were synthesized and labeled with no carrier added (n.c.a.) fluorine-18 through a radiochemical synthesis relying on the highly enantioselective reaction between 4-chloro-2-[18F]fluorobenzyl iodide and the lithium enolate of (2S)-1-(tert-butyloxycarbonyl)-2-(tert-butyl)-3-methyl-1,3-imidazolidine-4-one for (S)-4-chloro-2-[18F]fluorophenylalanine and (2S,5S)-1-(tert-butyloxycarbonyl)-2-(tert-butyl)-3,5-dimethyl-1,3-imidazolidine-4-one for (S)-(α-methyl) -4-chloro-2-[18F] fluorophenylalanine. Quantities of about 20–25 mCi were obtained at the end of sy nthesi s, ready for injection after hydrolysis and high performance liquid chromatography (HPLC) purification, with a radiochemical yield of 17%–20% corrected to the end of bombardment after a total synthesis time of 90–105 min from [18F] fluoride. The enantiomeric excesses were shown to be 97% or more for both molecules without chiral separation and the radiochemical and chemical purities were 98% or better. 相似文献
22.
G. Viesti B. Fornal F. Gramegna G. Prete R. A. Ricci G. D'Erasmo L. Fiore G. Guarino A. Pantaleo I. Iori A. Moroni P. Blasi F. Lucarelli 《Zeitschrift für Physik A Hadrons and Nuclei》1986,324(2):161-171
The reactions induced by 143 MeV32S on58Ni have been studied detecting discrete γ-rays in coincidence with projectile-like fragments (PLF). Information on PLF excitation probability and sequential decay of target-like fragments (TLF) has been obtained. For the28Si+62Zn outgoing channel at small energy loss (¦Q¦<20 MeV), both PLF and TLF data indicate that thermal equilibrium is not attained. The hypothesis of an equal excitation energy partition between the two reaction fragments does not describe properly experimental TLF data. A dependence of PLF excitation probability on the outgoing channel is found for the two final channels32S+58Ni and28Si+62Zn. The values of the spin alignment parameterP zz, derived for PLF and TLF from measurements ofγ-rays anisotropy, are in disagreement with the expectations of the transport theory for dissipative collisions. 相似文献
23.
We define a general concept of pseudo algebras over theories and 2-theories. A more restrictive such a notion was introduced in [Po Hu, Igor Kriz, Conformal field theory and elliptic cohomology, Adv. Math. 189 (2) (2004) 325-412, http://www.math.lsa.umich.edu/~ikriz/], but as noticed by M. Gould, did not capture the desired examples. The approach taken in this paper corrects the mistake by introducing a more general concept, allowing more flexibility in selecting coherence diagrams for pseudo algebras. 相似文献
24.
Andrew Fiore 《Numerical Functional Analysis & Optimization》2013,34(6):679-690
Our goal is to demonstrate the utility of the calculus of moving surfaces (CMS) in boundary variation problems. We discuss the relative advantages of the CMS compared to the alternative approach of interior variations. We illustrate the technique by calculating the two leading terms of a power series for the Laplace eigenvalues on an ellipse with semi-axes 1 + a and 1 + b, where a and b are small. We compare the CMS estimates with those obtained by the conventional finite element method with Richardson extrapolation. The comparison confirms the cubic rate of convergence for the CMS estimates. 相似文献
25.
26.
Silvia Vignolini Francesca Intonti Francesco Riboli Diederik Sybolt Wiersma Laurent Balet Lianhe H. Li Marco Francardi Annamaria Gerardino Andrea Fiore Massimo Gurioli 《Photonics and Nanostructures》2012,10(3):271-275
A local tuning of the modes of photonic crystal systems both to blue and to red sides of the resonance is implemented by nano-infiltration/evaporation of water and laser micro-oxidation. This technology is used to completely control coupled photonic nanocavities (photonic crystal molecules). Beside the standard condition of zero detuning between identical modes of the two cavities (homoatomic molecule), we are also able to produce coupling between two modes of different polarization and spatial distribution (heteroatomic molecule). 相似文献
27.
The M?bius form of the BFKL kernel in the next-to-leading order (NLO) in theories containing fermions and scalars in arbitrary
representations of the colour group is presented. The ambiguity of the NLO kernels permits to get agreement between the BFKL
approach and the colour dipole model and to find the quasi-conformal representation of the BFKL kernel. 相似文献
28.
Silvia Vignolini Francesca Intonti Francesco Riboli Diederik Sybolt Wiersma Laurent Balet Lianhe H. Li Marco Francardi Annamaria Gerardino Andrea Fiore Massimo Gurioli 《Photonics and Nanostructures》2012,10(3):251-255
The insertion of a metal-coated tip on the surface of a photonic crystal microcavity is used for simultaneous near field imaging of electric and magnetic fields in photonic crystal nanocavities, via the radiative emission of embedded semiconductor quantum dots (QD). The photoluminescence intensity map directly gives the electric field distribution, to which the electric dipole of the QD is coupled. The magnetic field generates, via Faraday's law, a circular current in the apex of the metallized probe that can be schematized as a ring. The resulting magnetic perturbation of the photonic modes induces a blue shift, which can be used to map the magnetic field, within a single near-field scan. 相似文献
29.
E. Puccia C. Mansueto M. V. Cangialosi T. Fiore R. Di Stefano C. Pellerito F. Triolo L. Pellerito 《应用有机金属化学》2001,15(3):213-220
Considerable attention has been given in recent years to the possibility that xenobiotics in the environment may affect reproduction in animals. In this study, the relative impact of tributyltin(IV) (TBT) chloride, one of the most toxic environmental pollutants, was investigated using Ciona intestinalis ovary as a model system. The pleiotropic effects of TBT exposure are concentration dependent and include a decrease of ATP levels, lipid content and nucleic acid content and synthesis. In contrast, a marked increase in calcium (Ca2+) and glucose content is observed. Furthermore, TBT alters enzymatic activity, inhibiting creatine kinase and stimulating alkaline phosphatase and cholinesterase (at concentrations higher than 10?5M in sterile sea water solution). The implications of these effects on reproduction and embryonal development are discussed, along with the possibility that they reflect an extreme cellular defence mechanism triggered to avoid deleterious consequences for the survival of the species.Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
30.
G. Del Fiore J. M. Peters L. Quaglia F. Boudjelida M. C. Pardon J. L. Piette R. Cantineau Ch. De Landsheere P. Rigo 《Journal of Radioanalytical and Nuclear Chemistry》1986,104(5):301-315
An automated continuous flow process has been developed for the synthesis of11C-ethanol and11C-butanol. These alcohols were synthesized via the same route. The reaction of11CO2 with methylmagnesium bromide or with n-propylmagnesium chloride, followed by a lithium aluminum hydride reduction and hydrolysis produced respectively11C-ethanol and11C-butanol. Preparation can be completed in 25 min. In each case the radiochemical purity, as determined by high pressure liquid chromatography /HPLC/ was greater than 98%. Biological quality control shows that the products are suitable for human use. The process has been completely automated to limit radiation exposure to personnel, reduce preparation time, and increase reproducibility. 相似文献