998 resultados para UNION CIVICA RADICAL
Resumo:
A new pathway to (+)-inthomycin C is reported that exploits an O-directed free radical hydrostannation reaction on (−)-12 and a Stille cross-coupling as key steps. Significantly, the latter process was effected on 19 where a gauche-pentane repulsive interaction could interfere. Our stereochemical studies on the alkynol (−)-12 and the enyne (+)-7 confirm that Ryu and Hatakeyama’s (3S)-stereochemical revision of (+)-inthomycin C is invalid and that Zeeck and Taylor’s original (3R)-stereostructure for (+)-inthomycin C is correct.
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Herein a new double O-directed free radical hydrostannation reaction is reported on the structurally complex dialkyldiyne 11. Through our use of a conformation-restraining acetal to help prevent stereocenter-compromising 1,5-H-atom abstraction reactions by vinyl radical intermediates, the two vinylstannanes of 10 were concurrently constructed with high stereocontrol using Ph3SnH/Et3B/O2. Distannane 10 was thereafter elaborated into the bis-vinyl iodide 9 via O-silylation and double I–Sn exchange; double Stille coupling of 9, O-desilylation, and oxidation thereafter furnished 8.
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The term “culture war” has become a generic expression for secular-catholic conflicts across nineteenth-century Europe. Yet, if measured by acts of violence, anticlericalism peaked in the years between 1927 and 1939, when thousands of Catholic priests and believers were imprisoned or executed and hundreds of churches razed in Mexico, Spain and Russia. This essay argues that not only in these three countries, but indeed across Europe a culture war raged in the interwar period. It takes, as a case study, the interaction of communist and Catholic actors located in the Vatican, the Soviet Union, and Germany in the period between the beginning of the Pontificate of Pius XI in 1922 and Hitler’s appointment as chancellor of Germany in 1933. Using correspondence and reports from the Vatican archives, this essay shows how Papal officials and communist leaders each sought to mobilize the German populace to achieve their own diplomatic ends. German Catholics and communists gladly responded to the call to arms that sounded from Rome and Moscow in 1930, but they did so also to further their own domestic goals. The case study shows how national contexts inflected the transnational dynamics of radical anti-Catholicism in interwar Europe. In the end, agitation against “godlessness” did not lead to the return of a “Christian State” desired by many conservative Christians. Instead, the culture war further destabilized the republic and added a religious dimension to a landscape well suited to National Socialist efforts to reach a Christian population otherwise mistrustful of its völkisch and anticlerical elements.
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The absolute yield of hydroxyl radicals per unit of deposited X-ray energy is determined for the first time for irradiated aqueous solutions containing metal nanoparticles based on a “reference” protocol. Measurements are made as a function of dose rate and nanoparticle concentration. Possible mechanisms for hydroxyl radical production are considered in turn: energy deposition in the nanoparticles followed by its transport into the surrounding environment is unable to account for observed yield whereas energy deposition in the water followed by a catalytic-like reaction at the water-nanoparticle interface can account for the total yield and its dependence on dose rate and nanoparticle concentration. This finding is important because current models used to account for nanoparticle enhancement to radiobiological damage only consider the primary interaction with the nanoparticle, not with the surrounding media. Nothing about the new mechanism appears to be specific to gold, the main requirements being the formation of a structured water layer in the vicinity of the nanoparticle possibly through the interaction of its charge and the water dipoles. The massive hydroxyl radical production is relevant to a number of application fields, particularly nanomedicine since the hydroxyl radical is responsible for the majority of radiation-induced DNA damage.
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For a multiplicity of socio-economic, geo-political, strategic and identity-based reasons, Turkey’s progress towards EU membership is often treated as a sui generis case. Yet although Turkey’s accession negotiations with the European Union (EU) are essentially a bilateral – and often stormy – affair, they take place within a wider and dynamic process of enlargement in which not only can the gloomy – sometimes dark – shadows of past and prospective enlargements be clearly detected, but so too can the often chill winds from ongoing, parallel negotiations with other candidates. How the EU negotiates accession and what it expects from candidates has continued to evolve since the EU began drawing up its framework for negotiations with Turkey ten years ago. This paper charts this evolution by first identifying changes in the light of Croatia’s negotiating experience, the ‘lessons learnt’ by the EU in meeting the challenges of Bulgarian and Romanian accession, the EU’s handling of Iceland’s membership bid and accession negotiations, and the revised approach to negotiating accession evident in the more recent frameworks for accession negotiations with Montenegro and Serbia. The paper then explores the extent to which these changes have impacted on the approach the EU has adopted in framing and progressing accession negotiations with Turkey. In doing so, it questions both the consistency with which the EU’s negotiates accession and the extent to which Turkey’s progress towards EU membership is conditioned by the broader dynamics of EU enlargement as opposed to simply the dynamics within EU-Turkey relations and domestic Turkish reform efforts.
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The Eurozone turmoil might have calmed, but the EU is still trying to free itself from a crisis that has had a dramatic impact on citizens’ economic and social well-being and raised serious questions about the union's future. David Phinnemore reports.
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The award of the Nobel Peace Prize to the European Union in 2012 was a reminder of the role of European integration in peacebuilding after the Second World War. For the 'Founding Fathers' of the European integration project, cross-border-cooperation was an integral element in building Europe's peace. Yet, in a Western Europe largely at peace for generations, peacebuilding as a relevant objective for European integration may be questioned. Moreover, the contribution of cross-border cooperation to conflict amelioration may be challenged on the grounds of its overwhelming economic focus. However, enlargement into Central Eastern Europe highlights once again the necessity of a peacebuilding objective for the European Union because of the multitude of real and potential conflicts encompassed within its expanded policy orbit. Drawing on evidence from selected 'borderscapes', this study examines 25 years of European Union cross-border cooperation as conflict amelioration and assesses its prospects in a political climate that emphasises borders as security barriers.