1,721,069 research outputs found
Cirugía de implantes postextracción con provisionalización inmediata en rehabilitaciones unitarias
No full textMartinelli, Matteo; director de proyecto: Kobayashi García, Hikaru2022-2023Grado en OdontologíaFacultad de Odontologí
Synthesis of sp3-enriched medicinal chemistry-relevant fragments and studies towards the total synthesis of nimbolide
Full text linkHighly oxygenated cyclohexanes, including (amino)cyclitols, are featured in natural products possessing a notable range of biological activities. As such, these building blocks are valuable tools for medicinal chemistry. While de novo synthetic strategies have provided access to select compounds, challenges including stereochemical density and complexity have hindered the development of a general approach to (amino)cyclitol structures. Herein, we report the use of arenophile chemistry to access dearomatized intermediates which are amenable to diverse downstream transformations. Practical guidelines were developed for the synthesis of natural and non-natural (amino)cyclitols from simple arenes through a series of strategic functionalization events.
Sp2-sp3 fragments play a vital role in fragment-based drug design (FBDD). Strategies to chemically modify them and efficiently access libraries of these compounds have been goals of the highest priority in the last decades. In this work, a series of sp2-sp3 fragments is synthesized and validated for that purpose, based on their measured physical-chemical properties. Selective C-H cyanation and allylation of these fragments is demonstrated by simple heating in presence of an appropriate hydrogen-atom transfer reagent and a radical acceptor. These conditions enable a streamlined access to covalent fragments in a single step, by direct introduction of the desired covalent binder. Preliminary results on vinylation, as well as late-stage functionalization of a drug analogue are disclosed. Nimbolide, a natural product belonging to the limonoids family, has attracted much attention thanks to its biological properties, especially against cancer cell lines. However, clinical studies still struggle to proceed due to the not fully understood metabolism and its poor pharmacokinetic properties. A flexible total synthesis would help addressing these problems by allowing access to a variety of analogues with the desired physical-chemical characteristics. The studies towards the synthesis of the two main fragments identified in our retrosynthetic analysis are here presented
Constraining Modified Gravity Theories With Cosmology
No full textWe study and constrain the Hu and Sawicki f(R) model using CMB and weak
lensing forecasted data. We also use the same data to constrain extended theories of
gravity and the subclass of f(R) theories using a general parameterization describing
departures from General Relativity. Moreover we study and constrain also a Dark
Coupling model where Dark Energy and Dark Matter are coupled toghether
Modelling of laminar flow in the inlet section of rectangular microchannels
No full textThis paper is a study of laminar flow in rectangular microchannels. The behaviour of compressible and incompressible fluids in microchannels was simulated using CFD software. Numerical data were compared to experimental measurements to test the validity of CFD models. The velocity profile of flow developing inside the channel is described as a function of the Reynolds number Re, varying from 100 to 2000, and the aspect ratio h/w, ranging from 1 to 0.125. The fundamental importance of the entrance length of microchannels is highlighted. Numerical data were applied to define analytical formulae covering the minimum entrance length for fully developed laminar flow of compressible fluids, viscous stress and incremental pressure drop effect during flow development, and the velocity profiles of flow for compressible and incompressible fluids
Smart Digital Twins nell'Industria 4.0
No full textLe industrie sono diventate entità produttive sempre più complesse. Coinvolgono tecnologie di vario tipo, di nuova e vecchia generazione, con realtà dove le macchine non hanno sostituito l’uomo e dove la loro integrazione trasversale è sempre più complessa. Inoltre, l’evoluzione delle richieste del mercato e la velocità nei loro cambiamenti rendono necessario dotarsi di sistemi produttivi in grado di rispondere tempestivamente alle nuove richieste, rendendo ancora più elevata la complessità degli impianti. I moderni progressi dell’informatica hanno generato grandi aspettative di miglioramento nel mondo della produzione industriale. Tuttavia, la natura distribuita di questi sistemi, la loro eterogeneità e complessità intrinseca rendono critica l’applicazione di queste soluzioni moderne. In risposta alle esigenze industriali, alla loro eterogeneità e alla rapida risposta ai cambiamenti richiesti, è quindi necessario un livello di astrazione capace di “disconnettere” in modo intelligente la complessità fisica da quella digitale. In questa tesi viene indagata e descritta una possibile astrazione del mondo fisico industriale attraverso i Digital Twins e la loro interazione con le moderne tecniche di Intelligenza Artificiale, al fine di rappresentare organicamente il contesto produttivo nel mondo digitale e migliorarne i processi, non solo produttivi ma anche della gestione globale.Industries have become increasingly complex production entities. They involve technologies of various types, of new and old generations, with realities where machines have not replaced man and where their transversal integration is increasingly complex. Furthermore, the evolving market demands and the speed in their changes make it necessary to have production systems capable of responding promptly to new requests, making the complexity of the systems even higher. Modern advances in computer science have generated great expectations for improvement in the industrial production world. However, the distributed nature of these systems, their heterogeneity and inherent complexity make the application of these modern solutions critical. In response to industrial requirements, their heterogeneity and the rapid response to changes required, a level of abstraction capable of intelligently ``disconnecting'' physical complexity from digital complexity is therefore necessary. In this dissertation, a possible abstraction of the physical industrial world is investigated and described through Digital Twins and their interaction with modern Artificial Intelligence techniques, in order to organically represent the production context in the digital world and improve its processes, not only productive but also of global management
Experimental comparative mixing performance of passive micromixers with H-shaped sub-channels
No full textThis paper presents a new type of passive microfluidicmixer called the ‘‘H-micromixer''.This type of passive micromixeris based on the splitting and recombination (SAR)process, meaning that the two fluids to be mixed are split and recombined to optimized the diffusion process.The paperalso describes an experimental investigation of the mixing process in three different geometries:T-micromixer,O-micromixer and H-micromixer. The laminar flowregime(0.08<Re<4.16)was considered during tests and image-based techniques were used to evaluate mixing efficiency.At all tested flowrates, experimental data show that the H-micromixer is more efficient than the other tested microdevices.The H-micromixer's efficiency is very high due to the SAR process: specifically,efficiency up to 98%can beachieved at Re=0.08
Experimental comparative mixing performance and pressure drop simulation of three passive micromixers
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