227 research outputs found

    Synthesis of spiro quasi[1]catenanes and quasi[1]rotaxanes via a templated backfolding strategy

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    Due to their well-defined three-dimensional geometry, spiro compounds are widely utilized in drug research. From the central tetrahedral carbon atom, besides the regular structure, an inverted spiro connectivity may be envisioned. Here we disclose the synthesis of this molecule class that we have coined quasi[1]catenanes. Next to their fascinating and aesthetic shape, the higher compactness as compared to regular spiro bicycles is noteworthy. To enable synthetic access to compact entangled multimacrocyclic molecules, we have developed a new strategy. The key element is a template, which is covalently connected to the linear precursors, and spatially directs the sterically congested backfolding macrocyclizations that are required to give quasi[1]catenanes. Similarly, quasi[1]rotaxanes are made

    Attempted [2]Catenane Synthesis via a Quasi[1]catenane by a Templated Backfolding Strategy

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    A templated backfolding concept to construct a [2]catenane was attempted via a quasi[1]catenane showing an inverted spiro geometry. The template is covalently connected to the ketal-connected semi-perpendicular-arranged linear precursors and spatially directs the sterically congested backfolding macrocyclizations that are required to give a quasi[1]catenane. So far, we are unable to hydrolyze the cyclic ketal to liberate the [2]catenane

    Highly parallel oligonucleotide purification and functionalization using reversible chemistry

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    We have developed a cost-effective, highly parallel method for purification and functionalization of 5ā€²-labeled oligonucleotides. The approach is based on 5ā€²-hexa-His phase tag purification, followed by exchange of the hexa-His tag for a functional group using reversible reaction chemistry. These methods are suitable for large-scale (micromole to millimole) production of oligonucleotides and are amenable to highly parallel processing of many oligonucleotides individually or in high complexity pools. Examples of the preparation of 5ā€²-biotin, 95-mer, oligonucleotide pools of >40K complexity at micromole scale are shown. These pools are prepared in up to ~16% yield and 90ā€“99% purity. Approaches for using this method in other applications are also discussed

    Brands in international and multiā€platform expansion strategies: economic and management issues

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    Powerful media branding has historically facilitated successful international expansion on the part of magazine and other content forms including film and TV formats. Multi-platform expansion is now increasingly central to the strategies of media companies and, as this chapter argues, effective use of branding in order to engage audiences effectively and to secure a prominent presence across digital platforms forms a core part of this. Drawing on original research into the experience of UK media companies, this chapter highlights some of the key economic, management and socio-cultural issues raised by the ever-increasing role of brands and branding in the strategies of international and multi-platform expansion that are increasingly common- place across media

    Urban energy consumption and CO2 emissions in Beijing: current and future

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    This paper calculates the energy consumption and CO2 emissions of Beijing over 2005ā€“2011 in light of the Beijingā€™s energy balance table and the carbon emission coefficients of IPCC. Furthermore, based on a series of energy conservation planning program issued in Beijing, the Long-range Energy Alternatives Planning System (LEAP)-BJ model is developed to study the energy consumption and CO2 emissions of Beijingā€™s six end-use sectors and the energy conversion sector over 2012ā€“2030 under the BAU scenario and POL scenario. Some results are found in this research: (1) During 2005ā€“2011, the energy consumption kept increasing, while the total CO2 emissions fluctuated obviously in 2008 and 2011. The energy structure and the industrial structure have been optimized to a certain extent. (2) If the policies are completely implemented, the POL scenario is projected to save 21.36 and 35.37 % of the total energy consumption and CO2 emissions than the BAU scenario during 2012 and 2030. (3) The POL scenario presents a more optimized energy structure compared with the BAU scenario, with the decrease of coal consumption and the increase of natural gas consumption. (4) The commerce and service sector and the energy conversion sector will become the largest contributor to energy consumption and CO2 emissions, respectively. The transport sector and the industrial sector are the two most potential sectors in energy savings and carbon reduction. In terms of subscenarios, the energy conservation in transport (TEC) is the most effective one. (5) The macroparameters, such as the GDP growth rate and the industrial structure, have great influence on the urban energy consumption and carbon emissions

    Essentially English : Sherlock Holmes at the BBC

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    Sir Arthur Conan Doyleā€™s Sherlock Holmes stories, currently enjoying renewed popularity on television via the BBCā€™s Sherlock (2010- ), have been adapted for the screen countless times around the world. Arguably best remembered are Granadaā€™s long-running strand with Jeremy Brett (1984-94), and the Universal film series of the 1940s, featuring Basil Rathbone and Nigel Bruce. Less frequently cited, however, are the two series produced by the BBC between 1965 and 1968, in which first Douglas Wilmer and later Peter Cushing took on the mantle of the Baker Street detective. Typically for the time ā€“ but against the wishes of the Conan Doyle estate - these programmes adopted a multi-camera studio model; a mode of production which made them less attractive to US networks than the single camera 35mm film output of commercial rivals such as ITC. Drawing upon material from the BBCā€™s Written Archives Centre, this article investigates the motivations underpinning the Corporationā€™s refusal to accommodate the estateā€™s exhortations to seek American co-production and utilise single camera filming, not least of which was the BBCā€™s stated desire to maintain the ā€˜essentially Englishā€™ quality of Sherlock Holmes. This decision would have significant repercussions for the seriesā€™ overseas saleability, and ā€“ despite impressive viewing figures and positive audience reaction at home in the UK ā€“ helped contribute to its ā€˜forgottenā€™ status with regard to the television canon
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