Semi-synthesis of three precursors of carbocyclic nucleoside analogues

The investigation of brand new compounds with potential anti-viral activity is currently in the limelight of worldwide research, in particular with regard to the will to eradicate the HIV virus. In this context, after the chemical synthesis approach, that has produced several drugs capable of slowing the course of the disease and improving the survival expectations, the latest research trends are involved in the search for anti-viral compounds from natural sources which could be active by themselves or may furnish their basic structures as useful building blocks to be employed in semisynthetic approaches

Phytochemical study of Caulerpa racemosa (Forsk.) J. Agarth, an invading alga in the habitat of La Maddalena Archipelago

Caulerpa racemosa is a marine Chlorophyta widely distributed in tropical areas, introduced into the Mediterranean Sea since 1990. It has been invading the Mediterranean Sea causing ecological problems. This invasive event can be considered as one of the most serious in the history of species introduced into the Mediterranean Sea, even if C. racemosa has not triggered as much attention as the famous 'killer alga' Caulerpa taxifolia. The aim of this work is to analyse phytochemically C. racemosa in the northern Sardinia area for secondary metabolites. Marine algae shows the molecular pattern of bis-indole alkaloids, sesquiterpenes, diterpenes and sterols. The intention is to expand phytochemical analysis in order to understand just how significant the anti-tumour, anti-inflammatory and antinociceptive actions can be

Phytochemical analysis of non–volatile fraction of Artemisia caerulescens subsp. densiflora (Viv.) (Asteraceae), an endemic species of La Maddalena Archipelago (Sardinia –Italy).

Artemisia caerulescens subsp. densiflora Viv. is a rare endemic species from Corsica and Sardinia. We studied a sample collected from Razzoli, an island of the La Maddalena Archipelago. The polar secondary metabolites content of this species was investigated for the first time in this study showing the presence of sesquiterpenoids, flavonoids, caffeoylquinic acids and a coumarin, with the presence of several compounds already recognised in this genus. The metabolites composition was analysed in two different phenological stages, post blooming and flowering. During the blooming stage, the plant showed a molecular pattern mainly represented by sesquiterpenes and sterols with a minor amount of phenolics, while in flowering stage the molecular pattern was more rich in flavonoids and phenylpropanoids

FLOvane: A new approach for high-pressure vane design

This paper presents a new unconventional philosophy for high-pressure (HP) vane design. It is proposed that the most natural design starting point for admitting and accelerating flow with minimum loss and secondary flow is a trumpet-shaped flow-path which gradually turns to the desired angle. Multiple trumpet-shaped inlets are seamlessly blended into the (annular or partitioned) combustor walls resulting in a highly lofted flow-path, rather than a traditional flow-path defined by distinct airfoil and endwall surfaces. We call this trumped-shaped inlet the fully lofted oval vane (FLOvane). The purpose of this paper is to describe the FLOvane concept and to present back-to-back CFD analyses of two current industrial gas turbines with conventional and FLOvanemodified designs. The resulting designs diverge significantly from conventional designs in terms of both process and final geometric form. Computational fluid dynamic predictions for the FLOvane-modified designs show improved aerodynamic performance characteristics, reduced heat load, improved cooling performance, improved thermal-mechanical life, and improved stage/engine efficiency. The mechanisms for improved performance include reduction of secondary flows, reduced mixing of coolant flow with the mainstream flow, reduced skin friction, and improved coolant distribution. In the two current industrial gas turbine engines, the absolute (percentage point) improvement in stage isentropic efficiency when the FLOvane design was included was estimated at 0.33% points and 0.40% points without cooling flow reduction, and 1.5% points in one case and much more is expected for the other case when cooling flow reductions were accounted for