A highly crystalline microporous hybrid organic-inorganic aluminosilicate resembling the AFI-type zeolite

ECS-14, a crystalline microporous hybrid organic-inorganic aluminosilicate, has been synthesized by using 1,4-bis-(triethoxysilyl)-benzene (BTEB) as a source of silica. Its structure contains a system of linear channels with 12-membered ring openings, running along the [001] direction, resembling the pore architecture of the AFI framework type.     

Kinetic effects of tartaric acid on the growth of chiral J-aggregates of tetrakis(4-sulfonatophenyl)porphyrin

The kinetics of growth for chiral J-aggregates of H(4)TPPS(4) porphyrin have been investigated under different experimental conditions in the presence of tartaric acid. The observed rate constants and the anisotropy factor g show a defined dependence on the enantiomer used as a chiral templating agent.     

Magnetic pH-responsive nanogels as multifunctional delivery tools for small interfering RNA (siRNA) molecules and iron oxide nanoparticles (IONPs)

We here exploit pH-responsive nanogels as carriers to deliver functional anti-GFP siRNA and superparamagnetic IONPs to HeLa-GFP cells. The siRNA release via pH-mediated endosomal escape is shown. The IONPs act first as magnetofection agents to boost cellular uptake and then as probes to track the release mechanism by electron microscopy.     

Microfluorescence analysis of nanostructuring inhomogeneity in optical fibers with embedded gallium oxide nanocrystals

A spectroscopic protocol is proposed to implement confocal microfluorescence imaging to the analysis of microinhomogeneity in the nanocrystallization of the core of fibers belonging to a new kind of broadband fiber amplifier based on glass with embedded nanocrystals. Nanocrystallization, crucial for achieving an adequate light emission efficiency of transition metal ions in these materials, has to be as homogeneous as possible in the fiber to assure optical amplification. This requirement calls for a sensitive method for monitoring nanostructuring in oxide glasses. Here we show that mapping microfluorescence excited at 633 nm by a He-Ne laser may give a useful tool in this regard, thanks to quasi-resonant excitation of coordination defects typical of germanosilicate materials, such as nonbridging oxygens and charged Ge-O-Ge sites, whose fluorescence are shown to undergo spectral modifications when nanocrystals form into the glass. The method has been positively checked on prototypes of optical fibers--preventively characterized by means of scanning electron microscopy and energy dispersive spectroscopy--fabricated from preforms of Ni-doped Li?O-Na?O-Sb?O?-Ga?O?-GeO?-SiO? glass in silica cladding and subjected to heat treatment to activate gallium oxide nanocrystal growth. The method indeed enables not only the mapping of the crystallization degree but also the identification of drawing-induced defects in the fiber cladding.     

Continuous flow synthesis and scale-up of glycine- and taurine-conjugated bile salts

A multi-gram scale protocol for the N-acyl amidation of bile acids with glycine and taurine has been successfully developed under continuous flow processing conditions. Selecting ursodeoxycholic acid (UDCA) as the model compound and N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ) as the condensing agent, a modular mesoreactor assisted flow set-up was employed to significantly speed up the optimization of the reaction conditions and the flow scale-up synthesis. The results in terms of yield, in line purification, analysis, and implemented flow set-up for the reaction optimization and large scale production are reported and discussed.     

Sparse 1D discrete Dirac operators I: Quantum transport

Some dynamical lower bounds for one-dimensional discrete Dirac operators with different classes of sparse potentials are presented, and the particular role of the particle mass is emphasized.     

Matrix completion problems over integral domains: The case with a diagonal of prescribed blocks

Let $\mathfrak{R}$ be an arbitrary integral domain, let $\wedge =\{{\lambda }_1\text{,}\dots \text{,}{\lambda }_n\}$ be a multiset of elements of $\mathfrak{R}$, let $\sigma$ be a permutation of $\{1\text{,}\dots \text{,}k\}$ let $n_1\text{,}\dots \text{,}{n}_k$ be positive integers such that $n_1+?+n_k=n$, and for $r=1\text{,}\dots \text{,}k$ let $A_r\in {\mathfrak{R}}^{n_r\times n_{\sigma (r)}}$. We are interested in the problem of finding a block matrix $Q={\left[Q_{\mathit{rs}}\right]}_{r\text{,}s=1}^k\in {\mathfrak{R}}^{n\times n}$ with spectrum $\mathrm{\Lambda }$ and such that $Q_{r\sigma (r)}=A_r$ for $r=1\text{,}\dots \text{,}k$. Cravo and Silva completely characterized the existence of such a matrix when $\mathfrak{R}$ is a field. In this work we construct a solution matrix $Q$ that solves the problem when $\mathfrak{R}$ is an integral domain with two exceptions: (i) $k=2$; (ii) $k\ge 3$, $\sigma (r)=r$ and $n_r>n/2$ for some $r$.What makes this work quite unique in this area is that we consider the problem over the more general algebraic structure of integral domains, which includes the important case of integers. Furthermore, we provide an explicit and easy to implement finite step algorithm that constructs an specific solution matrix (we point out that Cravo and Silva’s proof is not constructive).     

An extension of proximal methods for quasiconvex minimization on the nonnegative orthant

In this paper we propose an extension of proximal methods to solve minimization problems with quasiconvex objective functions on the nonnegative orthant. Assuming that the function is bounded from below and lower semicontinuous and using a general proximal distance, it is proved that the iterations given by our algorithm are well defined and stay in the positive orthant. If the objective function is quasiconvex we obtain the convergence of the iterates to a certain set which contains the set of optimal solutions and convergence to a KKT point if the function is continuously differentiable and the proximal parameters are bounded. Furthermore, we introduce a sufficient condition on the proximal distance such that the sequence converges to an optimal solution of the problem.     

Integrating on-line process control and imperfect corrective maintenance: An economical design

Existing studies of on-line process control are concerned with economic aspects, and the parameters of the processes are optimized with respect to the average cost per item produced. However, an equally important dimension is the adoption of an efficient maintenance policy. In most cases, only the frequency of the corrective adjustment is evaluated because it is assumed that the equipment becomes “as good as new” after corrective maintenance. For this condition to be met, a sophisticated and detailed corrective adjustment system needs to be employed. The aim of this paper is to propose an integrated economic model incorporating the following two dimensions: on-line process control and a corrective maintenance program. Both performances are objects of an average cost per item minimization. Adjustments are based on the location of the measurement of a quality characteristic of interest in a three decision zone. Numerical examples are illustrated in the proposal.     

Efficiency of the medical care industry: Evidence from the Italian regional system

What might be the relation between clinical research and efficiency of medical care suppliers? Is the hypothesis of a positive relation consistent? Considering efficiency as the supplier’s ability to maximize the number of patients hospitalized in a mobility process among regions (i.e. mobility balance), this work aims at highlighting the existence of a positive externality of pharmaceutical clinical research on that kind of efficiency. In other words, an externality is able to affect the patients’ perception of good/bad quality of outputs supplied by the medical care industry, leading their mobility process. Taking Italy and the mobility of patients among regions into account, an Operational Research study will be performed in order to support this assumption.The goal of this work is to show an alternative way to increase the efficiency of medical care suppliers on the market of health care, that is to say, through their competitiveness on the market of human experimentation.