96 research outputs found

    Exploring the scope and utility of dynamic covalent chemistry within polymeric nanoparticles

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    Dynamic covalent chemistry encompasses reversible bond forming reactions which proceed under equilibrium control, where the position of the equilibria are sensitive to changes in environment, and which are often able to undergo component exchange. These virtues provide polymeric nanoparticles incorporating dynamic covalent bonds with the ability to reconfigure or change their structural properties in response to stimuli. In Chapter 1 we critically discuss and evaluate the current state of the art whereby polymer chemists have exploited dynamic covalent bonds within responsive and adaptive polymeric nanoparticles. Chapter 2 describes the synthesis and study of a chemoresponsive polymeric micelle. In this work, aldehyde and alkoxyamine endfunctionalized polymers are shown to link together through a single oxime bond and then self-assemble into micellar aggregates. The chemoresponsive nature of these micellar aggregates is expressed when their disassembly is triggered through the addition of a small molecule alkoxyamine. Chemoresponsive core cross-linked star and nanogel nanoparticles which contain multiple imine cross-links are presented in Chapter 3. These imine linkages are utilized to facilitate the self-assembly process of the nanoparticles, which display chemoresponsive disassembly upon the addition of a small molecule amine. Chapter 4 describes the preparation of core cross-linked star polymers which are both pH-responsive and thermoresponsive. The pH-responsive nature is imparted through the pH-responsiveness of multiple imine linkages, and their thermoresponsive nature arises on account of the thermoresponsive polymer chains contained within their cores. In Chapter 5 nanoparticles possessing pH-responsive imine and redox-responsive disulfide cross-links have been developed where the simultaneous application of both low pH and a reducing agent is required to trigger their disassembly. It is shown that the application of either low pH or a reducing agent does not trigger disassembly. The research presented throughout this dissertation confirms the great potential of dynamic covalent chemistry in the development of stimuliresponsive polymeric nanoparticles.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Critical rationalism and macrosociology of globalisation

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    This thesis employs Critical Rationalism—an inter-subjective theory of rationality originated in Karl Popper’s conjectural theory of knowledge— in order to develop a new macrosociology of globalisation. It describes contemporary globalisation as the formation of a liberal globality through which the centrality of the Hobbesian struggle for political power has been superseded with the Lockean competition for economic interests. But the thesis argues that liberal globalisation suffers from fundamental societal deficits due to a global organisation of people based on economic competition rather than rational dialogue and social cooperation. The central question of thesis therefore is that ‘how emerging utilitarian-based liberal globality can be transformed into a global society of free and equal citizens?’ The thesis argues that people’s potential access to critical rationality enables them to agree upon one set of globally shared values concerning the equality of people and people-centric global institutions, which are required for creating a global society of free and equal citizens. Through its macrosociological analysis the thesis addresses the question of how such a system of globally shared values can operate as the cultural driving force of a radical global institutional change from the Lockean logic of economic competition to the Kantian logic of dialogue and social cooperation. The thesis concludes that intellectuals can employ the ideal-type of an open global society of free and equal persons in order to persuade global social movements to work for realising such a fundamental global institutional change towards a just and free global society.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Long-term effects of the new direct antiviral agents (DAAs) therapy for HCV-related mixed cryoglobulinaemia without renal involvement: a multicentre open-label study

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    Objective. To investigate the long-term effects and safety of new direct antiviral agents (DAAs) in patients with hepatitis C virus (HCV)-related mixed cryoglobulinaemia (MC) without renal involvement.Methods. The study enrolled 22 consecutive patients, 19 received sofosbuvir-based regimen and three patients received other DAAs, individually tailored according to latest guidelines. As of December 2016, the median length of follow-up was 17 months (range 13-21).Results. Extra-hepatic manifestations at enrollment were: purpura and arthralgia (12 cases), peripheral neuropathy (10 cases) and marginal zone Blymphomas (2 cases). After a four-week DAA therapy, all patients became HCV-negative. Moreover, after 48 weeks since the beginning of DAA treatment, sustained regression of purpura and arthralgias was observed respectively in eight and in nine cases; peripheral neuropathy improved in seven cases, and cryocrit median values decreased from three (1-20) at baseline to two (1-12) after 48 weeks. Two cases with indolent marginal zone lymphomas did not show any haematological response: size and number of the involved nodes remained unchanged. In addition, the monoclonal B-cell population found in the peripheral blood in four cases did not disappear after recovery from HCV-RNA. Mild side effects occurred in nine patients, but six patients developed ribavirin-related anaemia requiring reduction of ribavirin dose.Conclusion. DAA therapy is safe and effective to eradicate HCV in MC, but seems associated with satisfactory clinical response in mild or moderate cryoglobulinaemic vasculitis and no response in B-NHL

    Le savant et son époque à travers sa correspondance Seeger A. Bonebakker (1923-2005) et quelques notes sur Ḫalīl b. Aybak al-Ṣafadī (696-764/1297-1363)

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    This article proposes a survey of two great scholars’ in Arabic literature correspondences: a European of the 20th century, Seeger Adrianus Bonebakker, who is of special interest for us because he bequeathed all of his great library, personal notes and correspondence to Università Ca’ Foscari, and a subject of study of the former, Ḫalīl b. Aybak al-Ṣafadī, great littérateur and scholar of the first century of the Mamluk period. Letters sent and received are preserved in both cases and are primary sources on their network, but also on their personal life, personality and methodology

    HIGH RESOLUTION INFRARED SPECTRA OF C2D2C_{2}D_{2}

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    This research was supported, in part, by the U. S. Atomic Energy Commission (COO-882-15), and the National Science Foundation, through contracts with The Ohio State University Research Foundation. 1^{1} S. Ghersctti and K. Narahari Rao, J. Mol. Spectry (in press).Author Institution: Laboratory of Molecular Spectroscopy and Infrared Studies, Department of PhysicsSeveral bands of C2D2C_{2}D_{2} in the PbS and Ge:Hg resions have been measured using a high resolution vacuum infrared spectrograph, and rotational analyses of these have been performed. The results obtained combined with those previously reported1reported^{1} permit a highly accurate determination of the rotational constants for the ground state as well as for other vibrational states of this molecule. A set of constants which fits about thirty experimentally determined vibrational levels will also be discussed
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