Highly Diastereoselective Synthesis of 2,6‐Di[1‐(2‐alkylaziridin‐1‐yl)alkyl]pyridines,Useful Ligands in Palladium‐Catalyzed Asymmetric Allylic Alkylation

C₂‐Symmetrical, enantiopure 2,6‐di[1‐(1‐aziridinyl)alkyl]pyridines (DIAZAPs) were prepared by a high‐yielding, three‐step sequence starting from 2,6‐pyridinedicarbaldehyde and (S)‐valinol or (S)‐phenylglycinol. The new compounds were tested as ligands in palladium‐catalyzed allylation of carbanions in different solvents. Almost quantitative yield and up to 99 % enantiomeric excess were obtained in the reactions of the enolates derived from malonate, phenyl‐ and benzylmalonate dimethyl esters with 1,3‐diphenyl‐2‐propenyl ethyl carbonate.     

A robust nonsmooth generalized-α$\alpha $ scheme for flexible systems with impacts

Multibody System Dynamics - The aim of this work is the development of a robust and accurate time integrator for the simulation of the dynamics of multibody systems composed of rigid and/or...     

Meeting Interactivity Requirements in Mobile E-Witness: An Experimental Study

This paper describes the design and development of a session-layer load balancing mechanism and its deployment in a mobile surveillance system named Mobile E-Witness (MEW), which we have developed (Ghini et al., Multimedia Tools and Applications, 37(3), 293–318, 2008). The load balancing mechanism proposed in this paper allows MEW to effectively meet interactivity requirements and it is based on an “early retransmission” technique that exploits the overall bandwidth provided by a number of heterogeneous (broadband and metropolitan area) wireless adapters incorporated in MEW. This technique anticipates a suspected unavailability of the adapters in order to avoid the effects of network congestion and guarantee continuity of the communication service and support for multimedia services such as IP telephony. We have carried out an experimental evaluation of the MEW prototype in order to assess its effectiveness in meeting interactivity and responsiveness requirements. This paper summarizes our design and the principal results we have obtained from the evaluation mentioned above.     

Distance-based outlier queries in data streams: the novel task and algorithms

This work proposes a method for detecting distance-based outliers in data streams under the sliding window model. The novel notion of one-time outlier query is introduced in order to detect anomalies in the current window at arbitrary points-in-time. Three algorithms are presented. The first algorithm exactly answers to outlier queries, but has larger space requirements than the other two. The second algorithm is derived from the exact one, reduces memory requirements and returns an approximate answer based on estimations with a statistical guarantee. The third algorithm is a specialization of the approximate algorithm working with strictly fixed memory requirements. Accuracy properties and memory consumption of the algorithms have been theoretically assessed. Moreover experimental results have confirmed the effectiveness of the proposed approach and the good quality of the solutions.     

Inhibition of photosystem 2 in starch-enriched Chlamydomonas reinhardtii cells prevents the efficient induction of H2 production in sulfur-depleted cultures

In sulfur-deprived Chlamydomonas reinhardtii cells the activity of photosystem 2 (PSII) has been shown to have a crucial role in the photosynthetic production of H₂, since it allows the synthesis of internal reserves such as starch. In the present investigation, the PSII inhibitor 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) was added in starch-enriched and sulfur-depleted C. reinhardtii cultures 1) at the very end of the aerobic phase, and 2) soon after the culture started to evolve H₂. In the former case, production of H₂ on a volumetric basis was completely down-regulated, although starch mobilization was enhanced. In vitro tests showed that the hydrogenase enzyme was active, although its efficiency of utilization in vivo was lowered very soon in the experiment. When an inhibitor of Rubisco such as glycolaldehyde was added under the same conditions, no substantial improvement in H₂ production rates was noted. These findings indicate that, aside starch storage, PSII plays an active role in the induction of the H₂ production process.     

Pd–Ag multi-membranes module for hydrogen production by methane auto-thermal reforming

An experimental campaign has been carried out in order to assess the performance of a two-step membrane process in terms of hydrogen production by methane auto-thermal reforming.     

Multiscale design of a dairy beverage model composed of Candida utilis single cell protein supplemented with oleic acid

One of the main challenges in the food industry is to design strategies for the successful incorporation of natural sources of bioactive compounds. Recently, yogurts and other fermented dairy beverages have been proposed as ideal carriers of such bioactive compounds such as fatty acids and antioxidants that could improve consumers' health. However, the incorporation of new ingredients causes functional and structural modifications that may affect the consumers' preferences. In this work, a dairy beverage model supplemented with oleic acid has been designed by partial substitution of milk by Candida utilis single-cell protein extract. The changes in the structural properties of this new beverage were evaluated by following the fermentation process, pH, aggregate size, microstructure, and changes in rheological properties. Furthermore, molecular dynamics simulations were carried out to analyze the interaction between its main components. Our data revealed that samples with a percentage of milk substitution of 30% showed a higher viscosity as compared with the other percentages and less viscosity than the control (no substitution). These samples were then selected for fortification by incorporating oleic acid microcapsules. A concentration of 1.5 g/100 g was shown to be the optimal quantity of microcapsules for oleic acid supplementation. Molecular dynamic simulations revealed glutathione as an important component of the micro-gel structure. The present study forms the basis for novel studies where Candida utilis single-cell protein and microencapsulated essential oils could be used to design innovative bioproducts.