Enantioselective Reactions Promoted by Organocatalytic Species From The Natural Chiral Pool

During the course of my Ph.D. in the laboratories directed by Prof. Alfredo Ricci at the Department of Organic Chemistry “A. Mangini” of the University of Bologna, I was involved in the study and the application of a number of organocatalytic systems, all coming from the natural chiral pool. The first part of this thesis will be devoted to new homogeneous organocatalytic reactions promoted by Cinchona alkaloid-based organocatalysts. Quinine based catalysts were found to be a very effective catalyst for Diels-Alder reactions involving 3-vinylindoles. Excellent results in terms of yields and enantioselectivities were achieved, outlining also a remarkable organocatalytic operational mode mimicking enzymatic catalysis. The same reaction with 2-vinylindoles showed a completely different behaviour resulting in an unusual resolution-type process. The asymmetric formal [3+2] cycloaddition with in situ generated N-carbamoyl nitrones using Cinchona-derived quaternary ammonium salts as versatile catalysts under phase transfer conditions, outlines another application in organocatalysis of this class of alkaloids. During the seven months stage in the Prof. Helma Wennemers’ group at the Department of Chemistry of the University of Basel (Switzerland) I have been involved in organocatalysis promoted by oligopeptides. My contribution regarded the 1,4-addition reaction of aldehydes to nitroolefins. In the work performed at the Department of Organic Chemistry “A. Mangini” of the University of Bologna, in collaboration with the ‘Institut Charles Gerhardt-Montpellier, of Montpellier (France) the possibility of performing for the first time heterogeneous organocatalysis by using a natural polysaccharide biopolymer as the source of chirality was disclosed. With chitosan, derived from deacetylation of chitin, a highly enantioselective heterogeneous organocatalytic aldol reaction could be performed. The use of an eco-friendly medium such as water, the recyclability of the catalytic specie and the renewable nature of the polysaccharide are assets of this new approach in organocatalysis and open interesting perspectives for the use of biopolymers.

La ricostruzione dell'assetto topografico della VI regio augustea di Roma dal periodo repubblicano all'età tardoantica

La VI regio augustea di Roma rappresenta uno dei settori urbani maggiormente investiti dalle modifiche radicali compiute dall’uomo nel processo di urbanizzazione della città che ne hanno modificato profondamente la situazione altimetrica e la conformazione originaria. Questi notevoli cambiamenti ebbero origine sin dall’età antica, ma si intensificarono profondamente soprattutto nel periodo rinascimentale quando a partire da Pio IV e soprattutto con Sisto V, attivo in tante altre zone della città, si svilupparono numerose opere di rinnovamento urbanistico che incisero notevolmente sul volto e sulle caratteristiche della zona in esame. A partire dal Rinascimento fino ad arrivare ai grandi scavi della fine del 1800 tutto il quartiere incominciò a “popolarsi” di numerosi edifici di grande mole che andarono ad intaccare completamente le vestigia del periodo antico: la costruzione del Palazzo del Quirinale e dei vari palazzi nobiliari ma soprattutto la costruzione dei numerosi ministeri e della prima stazione Termini alla fine dell’800 comportarono numerosi sventramenti senza la produzione di una adeguata documentazione delle indagini di scavo. Questa ricerca intende ricostruire, in un’ottica diacronica, la topografia di uno dei quartieri centrali della Roma antica attraverso l’analisi dei principali fenomeni che contraddistinguono l’evoluzione del tessuto urbano sia per quanto riguarda le strutture pubbliche che in particolar modo quelle private. Infatti, il dato principale che emerge da questa ricerca è che questa regio si configura, a partire già dal periodo tardo-repubblicano, come un quartiere a vocazione prevalentemente residenziale, abitato soprattutto dall’alta aristocrazia appartenente alle più alte cariche dello Stato romano; oltre a domus ed insulae, sul Quirinale, vennero costruiti lungo il corso di tutta l’età repubblicana alcuni tra i più antichi templi della città che con la loro mole occuparono parte dello spazio collinare fino all’età tardoantica, rappresentando così una macroscopica e costante presenza nell’ingombro dello spazio edificato.

Córdoban Discourses: A Drama of Interreligious Dialogue

SETTING: Cordoba, Spain, 1135 CE, 29th year of the reign of ‘Ali “amir al-muslimin,” second king of the Berber Almoravid dynasty, rulers of Moorish Spain from 1071 to 1147. Cordoba, the capital of Andalus and the center of the Almoravid holdings in Spain, is a bustling cosmopolitan center, a crossroads for Europe and the Middle East, and the meeting-point of three religious traditions. Most significantly, Cordoba at this time is the hub of European intellectual activity. From the square—itself impressively large and surrounded by a massive collonade, the regularity and ordered beauty of which typifies the Moorish taste for symmetry (so beloved of M.C. Escher)—can be seen the huge Cordoban mosque, erected in the 8th-century by Khalif Abd-er-Rahman I to the glory of Allah, oft forgiving, most merciful. It is the second largest building in Islam, and the bastion of the still entrenched but soon to fade Muslim presence in western Europe. SCENE: Three figures sit upon stone benches beneath the westernmost colonnade of the Cordoban mosque, involved in an animated, though friendly discussion on matters of faith and reason, knowledge and God, language and logic. The host is none other than Jehudah Halevi, and his esteemed guests Master Peter Abelard and the venerable Råmånuja, whose obviously advanced age belies his youthful voice, gleaming eye, quick hands, and general exuberance. It is autumn, early evening…

Comparison of pre-operative dGEMRIC imaging with intra-operative findings in femoroacetabular impingement: preliminary findings

To study standard MRI and dGEMRIC in patients with symptomatic FAI undergoing surgical intervention and compare them with intra-operative findings to see if they were corroborative.

Diagnosis of endometriosis with imaging: a review

Endometriosis corresponds to ectopic endometrial glands and stroma outside the uterine cavity. Clinical symptoms include dysmenorrhoea, dyspareunia, infertility, painful defecation or cyclic urinary symptoms. Pelvic ultrasound is the primary imaging modality to identify and differentiate locations to the ovary (endometriomas) and the bladder wall. Characteristic sonographic features of endometriomas are diffuse low-level internal echos, multilocularity and hyperchoic foci in the wall. Differential diagnoses include corpus luteum, teratoma, cystadenoma, fibroma, tubo-ovarian abscess and carcinoma. Repeated ultrasound is highly recommended for unilocular cysts with low-level internal echoes to differentiate functional corpus luteum from endometriomas. Posterior locations of endometriosis include utero-sacral ligaments, torus uterinus, vagina and recto-sigmoid. Sonographic and MRI features are discussed for each location. Although ultrasound is able to diagnose most locations, its limited sensitivity for posterior lesions does not allow management decision in all patients. MRI has shown high accuracies for both anterior and posterior endometriosis and enables complete lesion mapping before surgery. Posterior locations demonstrate abnormal T2-hypointense, nodules with occasional T1-hyperintense spots and are easier to identify when peristaltic inhibitors and intravenous contrast media are used. Anterior locations benefit from the possibility of MRI urography sequences within the same examination. Rare locations and possible transformation into malignancy are discussed.

Development of room temperature operating single electron transistor using FIB etching and deposition technology

The single-electron transistor (SET) is one of the best candidates for future nano electronic circuits because of its ultralow power consumption, small size and unique functionality. SET devices operate on the principle of Coulomb blockade, which is more prominent at dimensions of a few nano meters. Typically, the SET device consists of two capacitively coupled ultra-small tunnel junctions with a nano island between them. In order to observe the Coulomb blockade effects in a SET device the charging energy of the device has to be greater that the thermal energy. This condition limits the operation of most of the existing SET devices to cryogenic temperatures. Room temperature operation of SET devices requires sub-10nm nano-islands due to the inverse dependence of charging energy on the radius of the conducting nano-island. Fabrication of sub-10nm structures using lithography processes is still a technological challenge. In the present investigation, Focused Ion Beam based etch and deposition technology is used to fabricate single electron transistors devices operating at room temperature. The SET device incorporates an array of tungsten nano-islands with an average diameter of 8nm. The fabricated devices are characterized at room temperature and clear Coulomb blockade and Coulomb oscillations are observed. An improvement in the resolution limitation of the FIB etching process is demonstrated by optimizing the thickness of the active layer. SET devices with structural and topological variation are developed to explore their impact on the behavior of the device. The threshold voltage of the device was minimized to ~500mV by minimizing the source-drain gap of the device to 17nm. Vertical source and drain terminals are fabricated to realize single-dot based SET device. A unique process flow is developed to fabricate Si dot based SET devices for better gate controllability in the device characteristic. The device vi parameters of the fabricated devices are extracted by using a conductance model. Finally, characteristic of these devices are validated with the simulated data from theoretical modeling.

Electronic Communications as a Distinct and Unique Object of Regulation

The present paper is an abridged version of the first chapter to the book EC Electronic Communications and Competition Law (London: Cameron May, 2007). It is intended to pinpoint the contours of the communications sector as an object of regulation - an exercise that is essential to any thoughts on appropriate regulatory design. The communications sector is defined through its salient features of being (i) network-bound; (ii) dynamic; (iii) converging; (iv) sensitive to regulation and society’s reactions; and as one (v) with special societal role and as (vi) part of the new economy.