Modelli e metodi di ottimizzazione in ambito Home Care: approcci robusti

L'Home Care è una metodologia di assistenza sanitaria sempre più diffusa, grazie ai riscontri positivi sulla qualità di vita dei pazienti, che possono avvalersi delle cure presso i loro domicili, e ad un non trascurabile vantaggio economico per l'ente che rilascia il servizio. Per questo, numerosi autori hanno proposto differenti modelli e metodi deterministici di supporto alle decisioni per l'assegnazione dei pazienti agli operatori e la generazione di tour ammissibili per questi ultimi. In letteratura rimangono, tuttavia, poco trattati gli approcci robusti e questi si limitano a considerare la variazione di disponibilità degli operatori e i tempi di servizio stocastici. In questo elaborato viene proposto un modello robusto, a partire da un modello deterministico proposto in letteratura, che considera scenari caratterizzati da richieste sia certe, che incerte. Notevole importanza viene conferita ai risultati computazionali, ottenuti dalla sperimentazione di istanze reali opportunamente modificate per considerare elementi di incertezza, al variare di alcuni specifici parametri. Dai test eseguiti, risulta che il modello ILP proposto sia di buona qualità per le istanze di medio-piccole dimensioni e riesca a garantire un buon bilanciamento di carico lavorativo tra gli operatori

Synthesis and Electrochemical Studies of Rhenium(I) and Molybdenum(0) Complexes as Electrocatalysts for Reduction of Carbon Dioxide

The photochemical and electrochemical conversion of CO2 to higher-energy products has been a focus of research as a path to renewable fuels. This thermodynamically unfavorable process can be improved by employing transition-metal coordination compounds which, in the form of molecular or supramolecular organometallic catalysts, are capable of mediating CO2 reduction. Among them, we focused on Rhenium and Molybdenum. However, whereas a wide number of Rhenium(I) carbonyl-diimine complexes showed to be photo/redox active, and has already been successfully tested for the electrocatalytic CO2 reduction, to our knowledge, there are no reports about the use of tetracarbonyl polypyridyl molybdenum(0) complexes as electrocatalysts for the reduction of CO2. In this perspective, some [Mo(CO)4(L)] (L= 2,2’-bipyridine (bpy); 1,10-phenantroline (phen) and similar derivatives) were synthesized and tested for electrochemical reduction of carbon dioxide. Moreover, a series of novel Re(I)-carbonyl diimine complexes has been synthesized and tested for the same purpose. The latter class of compounds is characterized by new polypyridyl ligands, derived from PNI-phen (N-(1,10-phenantroline)-4-(1-piperidinyl)naphthalene-1,8-dicarboximide), which revealed to be able to provide a 3000-fold excited state lifetime enhancement in a Re(I) charge-transfer complex [1]. The electrochemical behavior of both the classes of compounds was compared with the activity of Re(CO)3Cl(bipy) [2]. Quite surprisingly, CV measurements (in MeCN and acetone), performed under both inert and CO2 atmosphere at room temperature, revealed that [Mo(CO)4(2,2’-bipyridyl)] shows redox activity as electrocatalyst for CO2 reduction, although the overpotential at which the process occurs is rather negative (about -1.9 V vs SCE). The catalytic activity was also confirmed by controlled-potential electrolysis at -1.80 V, coupled with gas chromatography (GC)

Coupling Solid-State NMR with GIPAW ab Initio Calculations in Metal Hydrides and Borohydrides

An integrated experimental theoretical approach for the solid-state NMR investigation of a series of hydrogen-storage materials is illustrated. Seven experimental room-temperature structures of groups I and II metal hydrides and borohydrides, namely, NaH, LiH, NaBH4, MgH2, CaH2, Ca(BH4)(2), and LiBH4, were computationally optimized. Periodic lattice calculations were performed by means of the plane-wave method adopting the density functional theory (DFT) generalized gradient approximation (GGA) with the Perdew-Burke-Ernzerhof (PBE) functional as implemented in the Quantum ESPRESSO package. Projector augmented wave (PAW), including the gauge-including projected augmented-wave (GIPAW), methods for solid-state NMR calculations were used adopting both Rappe-Rabe-Kaxiras-Joannopoulos (RRKJ) ultrasoft pseudopotentials and new developed pseudopotentials. Computed GIPAW chemical shifts were critically compared with the experimental ones. A good agreement between experimental and computed rnultinuclear chemical shifts was obtained

Laparoscopic vs. open surgery for the treatment of iatrogenic colonoscopic perforations: a systematic review and meta-analysis

Quality assessment of the included non-randomized studies based on the Newcastle-Ottawa Scale (NOS). (DOCX 57 kb

Circulating hematopoietic stem cells and putative intestinal stem cells in coeliac disease

Background: The intestinal stem cells (ISC) modulation and the role of circulating hematopoietic stem cells (HSC) in coeliac disease (CD) are poorly understood. Our aim was to investigate the longitudinal modifications in peripheral blood HSC traffic and putative ISC density induced by gluten-free diet (GFD) in CD. Methods: Thirty-one CD patients and 7 controls were enrolled. Circulating CD133+ and CD34+ HSC were measured by flow cytometry, at enrolment and after 7 days and 1, 3, 6, 12, and 24 months of GFD. Endoscopy was performed at diagnosis and repeated at 6, 12, and 24 months following GFD. We used the Marsh-Oberhuber score to evaluate the histological severity of duodenal damage; immunohistochemistry was employed to measure the intraepithelial lymphoid infiltrate (IEL, CD3+ lymphoid cells) and the putative ISC compartment (CD133+ and Lgr5+ epithelial cells). Results: At enrolment, circulating HSCs were significantly increased in CD patients and they further augmented during the first week of GFD, but progressively decreased afterwards. CD patients presented with villous atrophy, abundant IEL and rare ISC residing at the crypt base. Upon GFD, IEL progressively decreased, while ISC density increased, peaking at 12 months. After 24 months of GFD, all patients were asymptomatic and their duodenal mucosa was macroscopically and histologically normal. Conclusions: In active CD patients, the ISC niche is depleted and there is an increased traffic of circulating HSC versus non-coeliac subjects. GFD induces a precocious mobilization of circulating HSC, which is followed by the expansion of the local ISC compartment, leading to mucosal healing and clinical remission

A full-Maxwell algorithm for the field-to-multiconductor line-coupling problem

A general method to study the response of a system of multiconductors, lying above a perfectly conducting ground and excited by a HF electromagnetic field wave, is presented in this paper. The governing system of integro-differential equations is solved by means of a numerical procedure based on a Fourier series transformation. It can be proved that the series in which the unknowns of the problem, namely the currents along the conductors, are developed converge to the exact solution and only few terms are needed. The obtained results have been compared with those of a widely employed scattering code, showing faster performances for a given accuracy. Therefore, the algorithm can be seen as a more accurate alternative to the classical transmission line theory (TL) for all the situations (short transmission line, interconnects, etc.) in which the line geometrical parameters and the frequencies of interest make TL a rough approximation