Morphology Modification of Polyethylene/Clay Nanocomposite Samples under Convergent Flow

The morphology of PE/CL nanocomposite samples subjected to convergent flows is studied. Elongational flow – the typical flow involved in spinning and film‐blowing processing operations – significantly increases with the reduction of the capillary diameter. The values of the convergent extensional stress (calculated by Cogswell's formula) for the PE/CL systems, for all the adopted capillary geometries, are greater than the calculated values for pure polyethylene. The applied convergent flow, at the entrance of the capillary, is able to change the clay morphology and consequently the final material properties on the PE/CL system with limited affinity between the matrix and organo‐modified clay particles.

     

Development of a Method for the High‐Throughput Quantification of Cellular Proteins

Hunting for huntingtin : We describe a screening assay based on the inducible expression of the mutant huntingtin protein in cells and on its highly sensitive homogenous determination. Rapid, reproducible, and robust protein determination was achieved through the use of two donor–acceptor‐labeled antibodies and time‐resolved FRET. The assay was developed and validated for ultra‐throughput screening of low‐molecular‐weight compounds modulating the expression of the mutant protein.

     

An Organocatalytic Synthesis of cis‐N‐Alkyl‐ and N‐Arylaziridine Carboxylates

An extremely mild protocol that employs readily available starting materials, i.e., aldehyde, amine and alkyl diazoacetate, returns structurally diverse N‐substituted‐C‐2/3‐difunctionalised aziridines in excellent yields and stereoselectivities when pyridinium triflate is incorporated as an organocatalyst. The reaction process is environmentally benign affording water and nitrogen as the only by‐products. This racemic protocol paves the way for the development of novel asymmetric organocatalysts capable of generating optically active aziridines.     

A stochastic model to assess the variability of blood glucose time series in diabetic patients self-monitoring

Several studies have shown that patients suffering from Diabetes Mellitus can significantly delay the onset and slow down the progression of diabetes micro- and macro-angiopathic complications through intensive monitoring and treatment. In general, intensive treatments imply a careful blood glucose level (BGL) self-monitoring. The analysis of BGL measurements is one of the most important tasks in order to assess the glucose metabolic control and to revise the therapeutic protocol. Recent clinical studies have shown the correlation between the glucose variability and the long-term diabetes related complications. In this paper, we propose a stochastic model to extract the time course of such variability from the self-monitoring BGL time series. This information can be conveniently combined with other analysis to evaluate the adequacy of the therapeutic protocol and to highlight periods characterized by an increasing glucose instability. The method here proposed has been validated on two simulated data sets and tested with success in the retrospective analysis of three patients' data sets.     

Automatic temperature controller for multielement array hyperthermia systems

This paper concerns the optimization and performance analysis of an automatic control algorithm for managing power output of large multielement array hyperthermia applicators. Simulation and corresponding measurement of controller performance in a solid tissue equivalent phantom model is utilized for analysis of controller response to dynamically varying thermal load conditions that simulate clinical treatments. The analysis leads to an optimum controller which demonstrates the ability to achieve a uniform and stable temperature profile over a large surface area regardless of surrounding thermal load. This paper presents several advancements to the performance of a previously published control routine, including: 1) simplified simulation techniques for thorough characterization of controller performance; 2) an optimization procedure leading to an improved hybrid control algorithm for maintaining optimal performance during periods of both "rising" and "steady-state" temperature; 3) performance analysis of a control algorithm tailored for large area hyperthermia treatments with a mulitelement array applicator. The optimized hybrid controller is applied to the conformal microwave array (CMA) hyperthermia system previously developed for heating large area surface disease such as diffuse chestwall recurrence of breast carcinoma, and shown to produce stable, uniform temperatures under the multielement array applicator for all thermal load conditions.     

Crystals and crystallinity in polymeric materials

A new view of the concepts of crystallinity and crystals in synthetic macromolecules is discussed. In polymeric materials, crystallinity may be present with the concomitant occurrence of large amounts of structural disorder and in the absence of true three-dimensional long-range order. The structures of semicrystalline polymeric materials are discussed in terms of idealized limit models of crystals, where long-range order may be achieved for structural features that are not necessarily coincident with single atoms and are not necessarily point-centered. Typical examples of non-point-centered structural features are the straight lines corresponding to the chain axes of polymer molecules. This view explains the unusual ability of polymers to crystallize even in the presence of a high degree of structural disorder.     

Development of antiviral fusion inhibitors: short modified peptides derived from the transmembrane glycoprotein of feline immunodeficiency virus

Feline immunodeficiency virus (FIV) is a naturally occurring pathogen that causes an AIDS-like syndrome in domestic cats and is a valuable model system by which criteria for antiviral vaccines and drugs development can be tested. The cell-entry step of the lentivirus life cycle is regarded as a promising target for the development of new generation inhibitors. We have previously described potent in vitro anti-FIV activity associated with a synthetic octapeptide, termed C8 (Ac-Trp-Glu-Asp-Trp-Val-Gly-Trp-Ile-NH2), containing the Trp-rich motif of FIV transmembrane glycoprotein, which shares a common structural framework with the corresponding molecule of HIV and appears to play a similar role in cell entry. In this report, in an attempt to develop simpler potential fusion inhibitors to be tested in vivo, we describe further studies focused on synthetic peptide analogues of C8. Since C8 inhibitory activity is dependent upon the Trp motif, we systematically replaced these residues with bulky and/or aromatic natural and unnatural amino acids, in order to develop a rational structure-activity relationship. Furthermore, the amino acids located between the Trp residues, which are not crucial for inhibitory activity, were replaced by simple alkyl spacers of appropriate length. Design, NMR structural analysis, in vitro anti-FIV activity in lymphoid cell cultures, and serum stability of these new analogues are reported. The final results indicate that a simpler hexapeptide (Ac-Nal2-Ape-Nal2-Ape-Nal2-Ile-NH2; Nal2 = 3-naphthalen-2-yl-L-alanine, Ape = 5-aminopentanoic acid), almost entirely made up of unnatural amino acid residues, has markedly increased enzymatic stability, while maintaining strong antiviral potency in vitro.