An exceptionally mild catalytic thioester aldol reaction inspired by polyketide biosynthesis

This report details our discovery of a new catalytic ester aldol reaction using malonic acid half thioesters (MAHTs) that directly affords beta-hydroxythioesters. The reaction is catalyzed by combination of a Cu(II) salt and an amine base, and it can be performed under exceptionally mild conditions (23 degrees C, open to the air, wet solvent). Methyl malonic acid half thioesters afforded syn aldol products with distereoselectivities greater than 6:1.     

Heuristics for optimizing 3D mapping missions over swarm-powered ad-hoc clouds

Journal of Heuristics - Drones have been getting more and more popular in many economy sectors. Both scientific and industrial communities aim at making the impact of drones even more disruptive by...     

Vacuum moulding of a superplastic in two dimensions

A mathematical model is proposed for the process of vacuum superplasticforming. The model exploits the fact that in most industrialapplications the sheet aspect ratio (thickness/sheet width)is small. After an initial consideration of some of the moregeneral properties and the literature of superplastic materials,the elastic/plastic deformation of an internally-inflated thin-walledcylinder is examined. Plates of arbitrary geometry are thenconsidered. A quasisteady model in which the sheet moves througha sequence of steady states is developed. Some simplified closed-formsolutions are examined, but for general cases a system of nonlinearpartial differential equations must be solved numerically. Anefficient and accurate semi-explicit numerical scheme is proposedand a simplified stability analysis is presented; the methodis then used to compute properties of superplastic vacuum mouldedsheets in a number of practically motivated cases.     

Diagnostic analysis of stone materials from underwater excavations: the case study of the Roman archaeological site of Baia (Naples,Italy)

This work belongs to the framework of the national research project “COMAS” (Planned COnservation, “in situ”, of underwater archaeological artifacts), funded by the Italian Ministry of Education, Universities and Research (MIUR), concerning the submarine archaeological area of Baia (Naples, Italy). The site includes remains of the ancient cities of Baiae and Portus Iulius, which, since the 4th century AD, started to be submerged because of the bradyseism phenomenon. The work aims to the characterization of four different types of stone materials collected from the site, specifically marbles, limestones, ignimbrites, and bricks, in order to investigate their state of conservation. In particular, specimens were sampled from some masonry structures and pavement slabs (opus sectile) in a specific area of the submerged site, called “Villa a Protiro”. In order to characterize archaeological samples from a mineralogical-petrographic point of view, polarized optical microscopy and X-ray diffraction analyses were carried out, while to assess their conservation state, the surface colonization by biodeteriogen agents and their interaction with the substrate were studied through observations under a stereomicroscope, scanning electron microscopy and Fourier transform infrared spectroscopy. Marble and limestone samples revealed an intense bioerosion phenomena, attributable to epilithic and endolithic forms, particularly boring sponges. On the contrary, ignimbrites suffer a lower degree of biological colonization related to the activity of other species, such as serpulids and bryozoans. In bricks, biocolonisation is correlated to the type of temper used in the artifact, the quartz pastes having a greater susceptibility to biological attack than the volcanic ones.     

Total syntheses of (R)-argentilactone and (R)-goniothalamin via catalytic enantioselective allylation of aldehydes

The total syntheses of (R)-argentilactone (five steps, 25% overall yield) and (R)-goniothalamin (three steps, 61% overall yield) have been described through the enantioselective catalytic allylation of aldehydes (including a propargylic aldehyde) which provided a rapid access to these natural products that display very interesting biological activities.     

An efficient implementation of a VNS/ILS heuristic for a real-life car sequencing problem

The car sequencing problem consists in sequencing a given set of cars to be produced in a single day. We address one of the variants of this problem, in which the objective of minimizing the number of violations of assembly constraints has a stronger weight than the minimization of the number of paint color changes. We present and describe in details a VNS/ILS approach for approximately solving this problem. Computational results on real-life test instances are reported. The work presented in this paper obtained the second prize in the challenge ROADEF’2005 sponsored by Renault.     

YOYO as a Dye to Track Penetration of LK15 DNA Complexes in Spheroids: Use and Limits

To elucidate the reasons underlying the poor penetration of non-viral vectors in tissues, relating transport properties to physico-chemical parameters of vectors may be crucial. These properties can be influenced by the presence of multiples labels that are used. Therefore utilizing a vector with minimum of labels preferably not more than one is important to studying penetration in tissues. The cell impermeant bisintercalating dye YOYO-1 was found suitable to both monitor the formation of complexes between DNA and an amphipathic peptide LK15 and, to track their penetration in HCT116 spheroids by confocal microscopy. The results revealed a limited decrease of fluorescence ascribed to the high affinity of YOYO-1 to bind DNA. The residual fluorescence of complexes can be exploited to monitor penetration into spheroids, after correction for YOYO-1 attenuation, and to revealing hyaluronidase-induced reduced binding. Hence high affinity dyes such as YOYO-1 with inefficiently quenched fluorescence may be important to establish a relation between novel medicines characteristics and penetration in tissues.     

Neuropeptide delivery to the brain: a von Willebrand factor signal peptide to direct neuropeptide secretion

Background  

Multiple neuropeptides, sometimes with opposing functions, can be produced from one precursor gene. To study the roles of the different neuropeptides encoded by one large precursor we developed a method to overexpress minigenes and establish local secretion.