Design, synthesis, and drug solubilising properties of the first folate-calix[4]arene conjugate

The first example of a folate-calix[4]arene conjugate was designed and synthesized via microwave-assisted click chemistry. In PBS medium at physiological pH, the conjugate formed soluble aggregates and showed the capability to improve the water-solubility of a hydrophobic drug model, such as indomethacin.     

On the relation between finite element and finite volume schemes for compressible flows with cylindrical and spherical symmetry

A complete set of equivalence conditions, connecting the node-centered finite volume and the mass-lumped finite element schemes, is derived for the first time for the one-dimensional compressible Euler equations with cylindrical and spherical symmetry. Analytical expressions for the evaluation of the equivalent cell volumes and interface normals in terms of the finite element integrals are presented. Numerical experiments for compressible unsteady flows, including expanding and converging shock problems, are carried out using the new approach and the differences with the results from a finite volume scheme violating the equivalence conditions are discussed.     

Singly bridged calix

Crowned calix[8]arenes are obtained by direct alkylation of p-tert-butylcalix[8]arene (1) with poly(ethylene glycol) ditosylates in the presence of various bases. K2CO3 promotes the preferential formation of 1,3-calix[8]crowns. Cs2CO3 mainly gives the 1,5-isomers, which are selectively obtained in high yields when shorter chains are used (1,5-crown-2, 88%; 1,5-crown-3, 78%). NaH affords the 1,4-isomers in yields up to 46%, often as the sole crown derivative, besides unreacted 1. 1,2-Calix[8]crowns are also obtained in appreciable amount in some instances. The observed regioselectivity is rationalized in terms of preferential formation of specific anions in dependence of the base strength. Dynamic NMR and modeling studies prove that the polyether chain, depending on its bridging mode, may significantly reduce the available space for the through the annulus passages leading to derivatives conformationally blocked (on the NMR time scale).     

An adaptive multiresolution semi‐intrusive scheme for UQ in compressible fluid problems

This paper deals with the introduction of a multiresolution strategy into the semi‐intrusive scheme, recently introduced by the authors, aiming to propagate uncertainties in unsteady compressible fluid applications. The mathematical framework of the multiresolution setting is presented for the cell‐average case, and the coupling with the semi‐intrusive scheme is described from both the theoretical and algorithmic point‐of‐view. Some reference test cases are performed to demonstrate the convergence properties and the efficiency of the overall scheme: the linear advection problem for both smooth and discontinuous initial conditions, the inviscid Burgers equation, and an uncertain shock tube problem obtained by modifying the well‐known Sod shock problem. For all the cases, the convergence curves are computed with respect to semi‐analytical (exact) solutions. In the case of the shock tube problem, an original technique to obtain a reference highly‐accurate numerical stochastic solution has also been developed. Copyright © 2015 John Wiley & Sons, Ltd.     

Phytochemical investigation of the needles of Abies nebrodensis (Lojac.) Mattei

Abstract

Abies nebrodensis (Lojac.) Mattei (Pinaceae) is a species living in a very small population only in a confined area of Sicily. In this study, the dichloromethane extract of the leaves was analyzed. Apart from three already known metabolites namely dehydroabietic acid; maltol; and rheosmin, previously detected in other species of Abies, a lanostane derivative was isolated. Its chemical structure was elucidated by means of extensive spectroscopic methods.     

Forward and backward electron emission cross-sections for 23 MeVu<Superscript>-1</Superscript> C,Ni and Au projectiles traversing C,Al , Ni,Ag , Au and Bi foils

A rather complete experimental study of forward and backward electron velocity spectra from thin foils bombarded with ions at constant velocity of 30 atomic units (23MeV u^-1) was performed. Three different beams ( ¹²C³⁺ , ⁵⁸Ni¹⁴⁺ and ¹⁹⁷Au³⁶⁺ and six different targets ( ¹²C , ²⁷Al , ^natNi , ^natAg , ¹⁹⁷Au and ²⁰⁹Bi of approximately 90μg cm^-2 thickness were used. This procedure allowed to study the evolution of electron emission (velocity and angular distributions) for the [projectile; target] matrix [ C , Ni , Au ; C , Al , Ni , Ag , Au , Bi ] in a wide angular range. The projectile and target dependence of absolute cross-sections for binary encounter-, Auger- and backward-emitted electrons are analyzed.     

Isospin aspects in nuclear reactions involving Ca beams at 25 MeV/nucleon

Isospin dependence of dynamical and thermodynamical properties observed in reactions ⁴⁰Ca+ ^40,48Ca and ⁴⁰Ca + ⁴⁶Ti at 25 MeV/nucleon has been studied. We used the CHIMERA multi-detector array. Strong isospin effects are seen in the isotopic distributions of light nuclei and in the competition between different reaction mechanisms in semi-central collisions. We will show also preliminary results obtained in nuclear collision ⁴⁸Ca + ⁴⁸Ca at 25MeV/nucleon, having very high N/Z value in the entrance channel (N/Z = 1.4). The enhancement of evaporation residue production confirms the strong role played by the N/Z degree of freedom in nuclear dynamics.     

Gamma-ray tracking with the MARS detector

The feasibility of the entire process of -ray tracking is demonstrated experimentally for the first time. The accuracy of the results is tested by the capability for Doppler correction of -rays emitted in flight. The resolution of the 847.8 keV ( ) transition detected with the MARS detector after Coulomb excitation of a ⁵⁶Fe beam could be improved from 15 keV to below 5 keV (FWHM).Received: 28 October 2002, Published online: 2 March 2004PACS: 29.30.Kv X- and gamma-ray spectroscopy - 29.40.Gx Tracking and position-sensitive detectors - 29.40.Wk Solid-state detectorsC.A. Ur: On leave from: NIPNE, Bucharest, Romania.     

Possibility to deduce the emission time sequence of neutrons and protons from the neutron-proton correlation function

Experimental information has been derived from the neutron-proton correlation function in order to deduce the time sequence of neutrons and protons emitted at 45 degrees in the E/A = 45 MeV 58Ni + 27Al reaction.