792 research outputs found

    Ethyl 4-benzyloxycarbonyl-5-[2,2-bis(benzyloxycarbonyl)vinyl]-3- methylpyrrole-2-carboxylate

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    The crystal structure of the title compound, C34H 31NO8, is stabilized by intramolecular C-H⋯O and N-H⋯O hydrogen bonds, intermolecular C-H⋯O hydrogen bonds, and C-H⋯π and π-π interactions. © 2006 International Union of Crystallography. All rights reserved

    Synthesis and Characterization of Temperature-Sensitive and Chemically Cross-Linked Poly(N-isopropylacrylamide)/Photosensitizer Hydrogels for Applications in Photodynamic Therapy

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    Copyright © 2018 American Chemical Society. A novel poly(N-isopropylacrylamide) (PNIPAM) hydrogel containing different photosensitizers (protoporphyrin IX (PpIX), pheophorbide a (Pba), and protoporphyrin IX dimethyl ester (PpIX-DME)) has been synthesized with a significant improvement in water solubility and potential for PDT applications compared to the individual photosensitizers (PSs). Conjugation of PpIX, Pba, and PpIX-DME to the poly(N-isopropylacrylamide) chain was achieved using the dispersion polymerization method. This study describes how the use of nanohydrogel structures to deliver a photosensitizer with low water solubility and high aggregation tendencies in polar solvents overcomes these limitations. FT-IR spectroscopy, UV-vis spectroscopy, 1 H NMR, fluorescence spectroscopy, SEM, and DLS analysis were used to characterize the PNIPAM-photosensitizer nanohydrogels. Spectroscopic studies indicate that the PpIX, Pba, and PpIX-DME photosensitizers are covalently conjugated to the polymer chains, which prevents aggregation and thus allows significant singlet oxygen production upon illumination. Likewise, the lower critical solution temperature was raised to ∼44 °C in the new PNIPAM-PS hydrogels. The PNIPAM hydrogels are biocompatible with > 90% cell viability even at high concentrations of the photosensitizer in vitro. Furthermore, a very sharp onset of light-dependent toxicity for the PpIX-based nanohydrogel in the nanomolar range and a more modest, but significant, photocytotoxic response for Pba-PNIPAM and PpIX-DME-PNIPAM nanohydrogels suggest that the new hydrogels have potential for applications in photodynamic therapy

    Integrity in Public Life: Reflections on a Duty of Candour

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    This article will evaluate whether a “duty of candour” on public employees including specifically health practitioners and police officers is an effective mechanism in terms for improving trust and openness. This is the context of the actions of the police in relation to the Hillsborough Stadium disaster in 1989 where 96 soccer fans died at the match due to ineffective policing. The formal identification of responsibility on the part of the police despite the attempt by the police to attribute blame elsewhere, was the starting point of a proposal for an explicit duty on officials in public bodies such as the police to tell the truth and be under a statutory “duty of candour.” The article provides an overview of the duty of candour, its subsequent development, legislatively and professionally in the context of the British health care system, where it currently exists, and the potential impact for the police. It is argued that engagement with the paradox between professional and organizational duty expressed through the language of culture and truth telling is necessary to reassert the importance of trust and integrity in a range of public bodies

    Harnessing Wicked Problems in Multi-stakeholder Partnerships

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    Despite the burgeoning literature on the governance and impact of cross-sector partnerships in the past two decades, the debate on how and when these collaborative arrangements address globally relevant problems and contribute to systemic change remains open. Building upon the notion of wicked problems and the literature on governing such wicked problems, this paper defines harnessing problems in multi-stakeholder partnerships (MSPs) as the approach of taking into account the nature of the problem and of organizing governance processes accordingly. The paper develops an innovative analytical framework that conceptualizes MSPs in terms of three governance processes (deliberation, decision-making and enforce-ment) harnessing three key dimensions of wicked problems (knowledge uncertainty, value conflict and dynamic complexity). The Roundtable on Sustainable Palm Oil provides an illustrative case study on how this analytical framework describes and explains organizational change in partnerships from a problem-based perspective. The framework can be used to better understand and predict the complex relationships between MSP governance processes, systemic change and societal problems, but also as a guiding tool in (re-)organizing governance processes to continuously re-assess the problems over time and address them accordingly
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