Hemifacial microsomia: Case report and literature review

Hemifacial microsomia (HFM) is a sporadic congenital malformation of the craniofacial structures derived from the first and second branchial arches. The incidence of HFM has been reported to range from 1 in 3,0001 to 1 in 26,0002 live births, making HFM the second most common congenital malformation in the face after cleft lip and/or palate. An 11-year-old girl came at Galeazzi Institute (Milan) in January 2017. She presented left hemifacial microsomia with absence of the left ramus of mandible and the left temporomandibular joint (tmj), part of the zygomatic arch, hypoplasia of the lateral and inferior orbital bone and of the zygomatic bone. She also presented a medial canthal dystopia. She underwent to costochondral bone graft and calvaria bone graft for reconstruction of part of the mandible and the TMJ. An emi-Le Fort I, emi-Le Fort III, and sagittal segmental osteotomy of the right mandible were performed to improve the correct occlusion. Traditionally, the costochondral graft has been considered the gold standard for ramus-condyle reconstruction in the pediatric mandible when appropriate. Some studies cite growth unpredictability and ankylosis as concerns with rib. Further studies examining carefully the factors predicting graft growth, such as size of cartilage cap, surgical technique, and postoperative physiotherapy, are warranted

Perturbation Theory for Metastable States of the Dirac Equation with Quadratic Vector Interaction

The spectral problem of the Dirac equation in an external quadratic vector potential is considered using the methods of the perturbation theory. The problem is singular and the perturbation series is asymptotic, so that the methods for dealing with divergent series must be used. Among these, the Distributional Borel Sum appears to be the most well suited tool to give answers and to describe the spectral properties of the system. A detailed investigation is made in one and in three space dimensions with a central potential. We present numerical results for the Dirac equation in one space dimension: these are obtained by determining the perturbation expansion and using the Pad\'e approximants for calculating the distributional Borel transform. A complete agreement is found with previous non-perturbative results obtained by the numerical solution of the singular boundary value problem and the determination of the density of the states from the continuous spectrum.Comment: 10 pages, 1 figur

Seismic analysis of the Roman Temple of Évora, Portugal

The Roman temple of Évora dates back to the 1st century AD and has undergone several changes throughout history, including various additions, which have been removed. Several archaeological studies have recently been carried out, but the structural safety of the temple is unknown. Of particular concern is the temple’s seismic resistance, as it is located in a region subjected to a moderate seismic hazard. The main purpose of this paper is to ascertain the temple’s behaviour under seismic excitation through limit analysis and discrete element analysis. Both analysis techniques will use the assumption that the structure is composed of rigid blocks connected with dry joints. Geometric information has been derived from a recent laser scanning surveying, while calibration undertaken using in-situ results from GPR and dynamic identification tests. The main results are presented and discussed in detail as well as the need for possible repair works within the framework of the ICARSAH guidelines

One-Dimensional Discrete Stark Hamiltonian and Resonance Scattering by Impurities

A one-dimensional discrete Stark Hamiltonian with a continuous electric field is constructed by extension theory methods. In absence of the impurities the model is proved to be exactly solvable, the spectrum is shown to be simple, continuous, filling the real axis; the eigenfunctions, the resolvent and the spectral measure are constructed explicitly. For this (unperturbed) system the resonance spectrum is shown to be empty. The model considering impurity in a single node is also constructed using the operator extension theory methods. The spectral analysis is performed and the dispersion equation for the resolvent singularities is obtained. The resonance spectrum is shown to contain infinite discrete set of resonances. One-to-one correspondence of the constructed Hamiltonian to some Lee-Friedrichs model is established.Comment: 20 pages, Latex, no figure

Highly enantioselective “inherently chiral” electroactive materials based on a 2,2' -biindole atropisomeric scaffold

Chiral oligothiophene monomers with C2 symmetry, based on 3,30 -bithiophene atropisomeric cores with high racemization barriers, have recently been shown to provide excellent chiral starting materials with high electroactivity for the easy preparation of enantiopure electroactive films endowed with powerful chirality manifestations. We now introduce an inherently chiral monomer based on a 2,20 -biindole core, as the prototype of a new inherently chiral monomer family, whose properties could be modulable through functionalization of the pyrrolic N atoms. By fast, regular electrooligomerization the new monomer yields inherently chiral films with high, reversible electroactivity and, above all, impressive enantioselectivity towards very different chiral probes, some of pharmaceutical interest, as generalscope electrode surfaces. Such results, while opening the way to a new, attractive inherently chiral selector class, nicely confirm the general validity of the inherent chirality strategy for chiral electrochemistry. Furthermore, the enantioselectivity of the new selectors not only holds with electroactive chiral probes, but also with circularly polarized light components as well as electron spins, resulting in good chiroptical and spin filter performances, which suggests fascinating correlations between the three contexts

Helicity: a non-conventional stereogenic element for designing inherently chiral ionic liquids for electrochemical enantiodifferentiation

Configurationally stable 5-aza[6]helicene (1) was envisaged as a promising scaffold for non-conventional ionic liquids (IL)s. It was prepared, purified, and separated into enantiomers by preparative HPLC on a chiral stationary phase. Enantiomerically pure quaternary salts of 1 with appropriate counterions were prepared and fully characterized. N-octyl-5-aza[6]helicenium bis triflimidate (2) was tested in very small quantities as a selector in achiral IL media to perform preliminary electrochemical enantiodifferentiation experiments on the antipodes of two different chiral probes. The new organic salt exhibited outstanding enantioselection performance with respect to these probes, thus opening the way to applications in the enantioselective electroanalysis of relevant bioactive molecules

Bifurcation and stability for Nonlinear Schroedinger equations with double well potential in the semiclassical limit

We consider the stationary solutions for a class of Schroedinger equations with a symmetric double-well potential and a nonlinear perturbation. Here, in the semiclassical limit we prove that the reduction to a finite-mode approximation give the stationary solutions, up to an exponentially small term, and that symmetry-breaking bifurcation occurs at a given value for the strength of the nonlinear term. The kind of bifurcation picture only depends on the non-linearity power. We then discuss the stability/instability properties of each branch of the stationary solutions. Finally, we consider an explicit one-dimensional toy model where the double well potential is given by means of a couple of attractive Dirac's delta pointwise interactions.Comment: 46 pages, 4 figure

Enantioselective voltammetry in chiral ionic liquid media

Enantioselective voltammetry in chiral ionic liquid media P. R. Mussini1*, S. Arnaboldi1, M. Longhi1, I.F. Buzzi1, S. Grecchi1, F. Sannicol\uf21, Simona Rizzo2, Voichita Michali1, E. Licandro1, S. Cauteruccio1, T. Bellini3, G. Zanchetta3, A. Gennaro,4 A.A. Isse4, C. Chiappe5, L. Guazzelli5 1 Universit\ue0 degli Studi di Milano, Dip. di Chimica, Via Golgi 19, 20133 Milano, Italy 2 Istituto di Scienze e Tecnologie Molecolari, CNR, via Golgi 19, 20133 Milano, Italy 3 Universit\ue0 degli Studi di Milano, Dip. di Biotecnologie Mediche e Medicina Traslazionale, Via Fratelli Cervi 93, 20090 Segrate (MI), Italy 4 Universit\ue0 degli Studi di Padova, Dip.di Scienze Chimiche, Via Marzolo 1, 35131 Padova, Italy 5 Universit\ue0 degli Studi di Pisa, Dip. di Farmacia, via Bonanno 33, 56126 Pisa, Italy. *[email protected] Chiral media enabling enantiorecognition of chiral probes on achiral electrodes (in terms of significantly different peak potentials for the two probe enantiomers) represent an attractive target in voltammetry. Concerning possible ad hoc strategies, (a) on one hand, transmission of the chiral information should be more and more efficient with increasing structural order at the chiral medium| charged electrode interphase, and it has been recently shown that ionic liquid|electrode interphases are extremely well organized for many layers [1]; (b) on the other hand, outstanding enantioselection performances have been recently observed on electrode surfaces consisting in "inherently chiral" oligomer films, in which chirality originates from the whole main molecular backbone (also determining the material electroactivity), on account of a tailored torsion with high racemization barrier [2-6]. Combining both approaches, we recently developed two "inherently chiral" ionic liquids, consisting of dialkylated bicollidinium salts, with an atropisomeric bipyridinium cation featuring at least one octyl chain and bistrifilimidate counteranions.[7] They show high enantioselectivity in terms of wide potential differences for the enantiomers of a chiral probe when tested even as low concentration additives in commercial achiral ionic liquids. Importantly, similar ability (increasing with additive concentration) was also shown by other selectors of the same family, having shorter alkyl chains and/or different counteranions, and thus solid at room temperature but easier to synthesize [7]. Using such chiral selectors as additives in an achiral ionic liquid rather than as bulk media is even more attractive, since only a small quantity of the enantiopure selector is needed and a low melting point is no more required, but only sufficient solubility in the achiral ionic liquid. For instance, this allowed us to successfully exploit as additives for chiral voltammetry in ionic liquids other inherently chiral selectors based on different stereogenic elements, i.e., a bibenzimidazole atropisomeric scaffold [8,9] and a helicene one. The study provides further evidence of the general validity of the "inherent chirality" strategy, since large potential differences are observed on achiral electrodes for the enantiomers of chiral probes even of very different structure and electroactivity (like in our parallel research on inherently chiral electrodes), and possibly even in experiments with more than one chiral probe. Work is also in progress to better elucidate the process, including evaluation of the twisting power of our selectors as well as comparison with a family of ionic liquids and additives having cations derived from the natural pool, in which chirality originates from one or more stereocentres. References [1] Langmuir 2016, 32, 9507-9512. [2] Angew. Chem. Int. Ed. 2014, 53, 2623 [3] Chem. Eur. J. 2014, 20, 15298. [4] Chem. Sci. 2015, 6,1706. [5] Chem. Eur. J. 2016 , 22,10839. [6] Anal. Bioanal. Chem. 2016, 408, 7243. [7] Angew. Chem. Int. Ed. 2017, 56, 2079. [8] Electrochim. Acta 2015, 179, 250-262. [9] Electrochem. Comm. 2018, accepted. Acknowledgment. The support of Fondazione Cariplo/Regione Lombardia "Avviso congiunto per l\u2019incremento dell\u2019attrattivit\ue0 del sistema di ricerca lombardo e della competitivit\ue0 dei ricercatori candidati su strumenti ERC - edizione 2016\u201d (Project 2016-0923) to our chiral electrochemistry and electroanalysis research is gratefully acknowledged

How can the waste management sector contribute to overcoming barriers to the circular economy?

This paper contributes to an emerging literature stream advocating the multifaceted involvement of the waste management sector in supporting the up-scaling of the circular economy (CE). It explores the role of waste collection and recycling platforms in overcoming various barriers to CE implementation, inductively analyzing the case of postconsumer wood in Italy. Data were collected from multiple sources: interviews with 33 informants, participation in project meetings, site visits, and public and private documents. The case shows how waste collection platforms can perform different activities that can help address cultural, regulatory, market, and technological barriers. First, these platforms can contribute to stimulating demand for postconsumer wood, carrying out information and communication activities, and fostering the development of a positive image of the recovered material. Second, the platforms can contribute to defining and implementing the conditions to enable the activation of recycling processes