On the standard K-loop structure of positive invertible elements in a C*-algebra

We investigate the algebraic properties of the operation a {ring operator} b = sqrt(a) b sqrt(a) on the set of all positive invertible elements of a C*-algebra A. We show that its commutativity, associativity and distributivity are each equivalent to the commutativity of A. We present abstract characterizations of the operation {ring operator} and a few related ones, too. © 2014 Elsevier Inc. All rights reserved

Neumark Operators and Sharp Reconstructions, the finite dimensional case

A commutative POV measure $F$ with real spectrum is characterized by the existence of a PV measure $E$ (the sharp reconstruction of $F$) with real spectrum such that $F$ can be interpreted as a randomization of $E$. This paper focuses on the relationships between this characterization of commutative POV measures and Neumark's extension theorem. In particular, we show that in the finite dimensional case there exists a relation between the Neumark operator corresponding to the extension of $F$ and the sharp reconstruction of $F$. The relevance of this result to the theory of non-ideal quantum measurement and to the definition of unsharpness is analyzed.Comment: 37 page

Towards a realistic interpretation of quantum mechanics providing a model of the physical world

It is argued that a realistic interpretation of quantum mechanics is possible and useful. Current interpretations, from Copenhagen to many worlds are critically revisited. The difficulties for intuitive models of quantum physics are pointed out and possible solutions proposed. In particular the existence of discrete states, the quantum jumps, the alleged lack of objective properties, measurement theory, the probabilistic character of quantum physics, the wave-particle du- ality and the Bell inequalities are analyzed. The sketch of a realistic picture of the quantum world is presented. It rests upon the assump- tion that quantum mechanics is a stochastic theory whose randomness derives from the existence of vacuum fields. They correspond to the vacuum fluctuations of quantum field theory, but taken as real rather than virtual.Comment: 43 pages, paper throughout revised and somewhat enlarged, sections on the Bell inequalities and on the sketch of a picture of the quantum world rewritten, new references adde

Fabry disease: perspectives of urinary proteomics.

Fabry disease (FD) is an X-linked lysosomal storage disorder caused by mutations in the gene encoding the lysosomal enzyme a-galactosidase A (a-GalA). The resulting deficiency in a-GalA activity leads to intra-lysosomal accumulation of neutral glycosphingolipids, mainly globotriaosylceramide (Gb3), in various organ systems. As a consequence, a multisystem disorder develops, culminating in strokes and progressive renal and cardiac dysfunction. Enzyme replacement therapy (ERT) offers a specific treatment for patients affected by FD, though monitoring treatment is hampered by a lack of surrogate markers of response. Furthermore, even if signs and symptoms of the disease become manifest in childhood, its diagnosis is often delayed. Biomarkers that predict disease progression and respond relatively quickly to effective therapy may be useful to follow individual patients or groups of patients. Here we report the use of 2 different mass spectrometry-based proteomic techniques to identify disease-associated compositional changes that can be used as early biomarkers of the pathology, as well as for monitoring the effectiveness of ERT. To this purpose, we compared the renal Fabry urinary proteome with normal (control) urine using, respectively, 2-dimensional gel electrophoresis and label-free quantification. Our preliminary results show that the urinary protein pattern of affected patients can be easily distinguished from that of healthy subjects both qualitatively and quantitatively, thus encouraging further studies in the search for FD-specific biomarkers using this proteomic approac

Synthesis and thermotropic properties of new green electrochromic ionic liquid crystals

Novel 1,1′-bis(4-alkylphenyl)-[4,4′-bipyridine]-1,1′-diium salts, with alkyl chains of different lengths (8, 10 and 14 carbon atoms) and with different counteranions (Cl-, NTf2-, OTf-, OTs-, PF6-, BPh4-), have been prepared and fully characterized for their thermotropic behavior by polarized optical microscopy (POM), and calorimetric measurements. Almost all the synthesized compounds showed a high thermal stability, a wide temperature range of liquid-crystalline mesophase and, for some of them, the LC transition temperatures were relatively low. These compounds also exhibited electrochromic properties, which have been studied both in solution and in the LC phase, making the new materials very interesting for different opto-electronic applications