Seismic isolation of buildings using composite foundations based on metamaterials

Metamaterials can be engineered to interact with waves in entirely new ways, finding application on the nanoscale in various fields such as optics and acoustics. In addition, acoustic metamaterials can be used in large-scale experiments for filtering and manipulating seismic waves (seismic metamaterials). Here, we propose seismic isolation based on a device that combines some properties of seismic metamaterials (e.g., periodic mass-in-mass systems) with that of a standard foundation positioned right below the building for isolation purposes. The concepts on which this solution is based are the local resonance and a dual-stiffness structure that preserves large (small) rigidity for compression (shear) effects. In other words, this paper introduces a different approach to seismic isolation by using certain principles of seismic metamaterials. The experimental demonstrator tested on the laboratory scale exhibits a spectral bandgap that begins at 4.5 Hz. Within the bandgap, it filters more than 50% of the sei..

CCNE1 and survival of patients with tubo-ovarian high-grade serous carcinoma: An Ovarian Tumor Tissue Analysis consortium study

BACKGROUND: Cyclin E1 (CCNE1) is a potential predictive marker and therapeutic target in tubo-ovarian high-grade serous carcinoma (HGSC). Smaller studies have revealed unfavorable associations for CCNE1 amplification and CCNE1 overexpression with survival, but to date no large-scale, histotype-specific validation has been performed. The hypothesis was that high-level amplification of CCNE1 and CCNE1 overexpression, as well as a combination of the two, are linked to shorter overall survival in HGSC. METHODS: Within the Ovarian Tumor Tissue Analysis consortium, amplification status and protein level in 3029 HGSC cases and mRNA expression in 2419 samples were investigated. RESULTS: High-level amplification (>8 copies by chromogenic in situ hybridization) was found in 8.6% of HGSC and overexpression (>60% with at least 5% demonstrating strong intensity by immunohistochemistry) was found in 22.4%. CCNE1 high-level amplification and overexpression both were linked to shorter overall survival in multivariate survival analysis adjusted for age and stage, with hazard stratification by study (hazard ratio [HR], 1.26; 95% CI, 1.08-1.47, p = .034, and HR, 1.18; 95% CI, 1.05-1.32, p = .015, respectively). This was also true for cases with combined high-level amplification/overexpression (HR, 1.26; 95% CI, 1.09-1.47, p = .033). CCNE1 mRNA expression was not associated with overall survival (HR, 1.00 per 1-SD increase; 95% CI, 0.94-1.06; p = .58). CCNE1 high-level amplification is mutually exclusive with the presence of germline BRCA1/2 pathogenic variants and shows an inverse association to RB1 loss. CONCLUSION: This study provides large-scale validation that CCNE1 high-level amplification is associated with shorter survival, supporting its utility as a prognostic biomarker in HGSC

Characterizing slope regions

This paper provides a theoretical characterization of monotonically connected image surface regions, called slope regions. The characterization is given by several topological properties described in terms of critical points relative to the region.We formally prove the necessary and sufficient conditions that a region needs to satisfy to be a slope region.We also provide a prototype of slope regions which is general and contains, as particular cases, the prototypes studied and published in previous conference papers.Ministerio de Ciencia e Innovación PID2019-107339GB-I0

Counting slope regions in the surface graphs

The discrete version of a continuous surface sampled at optimum sampling rate can be well expressed in form of a neighborhood graph containing the critical points (maxima, minima, saddles) of the surface. Basic operations on the graph such as edge contraction and removal eliminate non-critical points and collapse plateau regions resulting in the formation of a graph pyramid. If the neighborhood graph is well-composed, faces in the graph pyramid are slope regions. In this paper we focus on the graph on the top of the pyramid which will contain critical points only, self-loops and multiple edges connecting the same vertices. We enumerate the different possible configurations of slope regions, forming a catalogue of different configurations when combining slope regions and studying the number of slope regions on the top

Linearity of Client/Server Systems

An important property of a client/server system is the independence of the interaction between the server and a client from the interactions that the server might have with other possible clients. In this paper we try to give a definition of such a property, that we called linearity, by means of the Process Algebra formalism. Through some examples of linear and non linear systems, we illustrate the expressiveness of our definition. Moreover, we present a sufficient condition for linearity and discuss the preservation of linearity w.r.t. process-algebraic operators applied to linear systems. 1 Introduction The growth of computer networks and distributed computing has led to the development of the client/server paradigm, which is widespread nowadays. A client/server system is a composite system which allows distributed computing, analysis and presentation [Si92]. The client is a process (program) that sends a message to a server process (program) requesting that the latter performs a ta..

La nostra esperienza sull'impiego delle protesi di Atkinson nel trattamento palliativo delle stenosi neoplastiche dell'esofago

I1 cancro dell’esofago rappresenta una delle neoplasie più temibili in quanto, nonostante la sua lenta evoluzione, provoca un grave stato di denutrizione per la disfagia che sempre, in misura più o meno rilevante, affligge i pazienti al momento della diagnosi. Per tale motivo, quando non è possibile l’exeresi radicale della neoplasia, il compito del chirurgo è quello di provvedere alla ricanalizzazione del viscere. In quest’ambito ha trovato collocazione il trattamento endoscopico che, pur essendo palliativo, consente con varie metodiche di sollevare il paziente dalla sintomatologia disfagica. Il trattamento endoscopico per la ricanalizzazione di una stenosi esofagea maligna si avvale di molteplici tecniche, come la dilatazione strumentale, la disostruzione con tecniche che provocano necrosi tumorale (infiltrazione di etanolo assoluto, diatermocoagulazione mono-bipolare, laser), il posizionamento di una protesi. In questo lavoro gli AA. riportano l’esperienza dell’Istituto di Chirurgia Toracica e Cardiovascolare dell’Università di Messina sulla ricanalizzazione dell’esofago con protesi di Atkinson, sottolineando le indicazioni, i vantaggi ed i limiti di una metodica che garantisce un ottimo risultato sotto il profilo strettamente nutrizionale

Il trattamento delle varici esofagee in emergenza

Gli Autori riportano la loro esperienza sul trattamento delle varici esofagee in fase di sanguinamento. Sono stati analizzati i risultati relativi a 107 pazienti per i quali è stato adottato un protocollo terapeutico che ha previsto la rianimazione cardiocircolatoria, l’emostasi farmacologica con Somatostatina e.v. e meccanica con sonda di Sengastaken, la sclerosi endoscopica. Tra i 38 pazienti sottoposti a scleroterapia, un definitivo arresto dell’emorragia è stato ottenuto in 33 (86.8%), con una mortalità del 5.2% (2/38) ed un basso tasso di complicanze minori. Nel gruppo di controllo l’arresto del sanguinamento è stato ottenuto nel 67,5% dei pazienti (25/37), ma la percentuale di recidive emorragiche precoci è stata significativamente maggiore rispetto al gruppo di studio (59% vs 9%). L’intervento chirurgico di deconnessione azygos-portale è stato gravato di una mortaliltà del 33,3% (1/3). Sulla base dei risultati gli Autori concludono che la sclerosi endoscopica rappresenta il trattamento di scelta nei pazienti con varici esofagee sanguinanti per la sua elevata efficacia, tollerabilità, semplicità d’esecuzione, sicurezza e basso costo