1,602 research outputs found

    Nickel-Catalyzed Mizoroki-Heck Reaction of Aryl Sulfonates and Chlorides with Electronically Unbiased Terminal Olefins: High Selectivity for Branched Products

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    Achieving high selectivity in the Heck reaction of electronically unbiased alkenes has been a longstanding challenge. Using a nickel-catalyzed cationic Heck reaction, we were able to achieve excellent selectivity for branched products (≥19:1 in all cases) over a wide range of aryl electrophiles and aliphatic olefins. A bidentate ligand with a suitable bite angle and steric profile was key to obtaining high branched/linear selectivity, whereas the appropriate base suppressed alkene isomerization of the product. Although aryl triflates are traditionally used to access the cationic Heck pathway, we have shown that, by using triethylsilyl trifluoromethanesulfonate, we can effect a counterion exchange of the catalytic nickel complex, such that cheaper and more stable aryl chlorides, mesylates, tosylates, and sulfamates can be used to yield the same branched products with high selectivity.National Institute of General Medical Sciences (U.S.) (NIGMS (GM62755))National Institutes of Health (U.S.) (NIH Postdoctoral Fellowship)National Science Foundation (U.S.) (NSF Graduate Research Fellowship

    Embedded Social Science and the British Government COVID-19 Response

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    The complex and evolving nature of the SARS-CoV-2 pandemic poses significant challenges to national and international emergency preparedness and response. Governments must navigate streams of emerging data in real time, synthesising knowledge from diverse sources to inform policy. The UK government drew on experiences from earlier pandemics to bridge perceived gaps between social science research and policy through the secondment of early-career academics as embedded scientists. In this article, we present comparative ethnographic data describing embedded social scientists’ contributions to UK COVID-19 preparedness and response. We find that the liminal position, loose identities, and high degree of autonomy of embedded scientists allowed these individuals to navigate multiple networks to strengthen and legitimise the role of social science within policy debates

    Year in review 2006: Critical Care – paediatrics

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    In 2006, paediatric intensive care-related subjects were discussed in a number of papers published in various journals, including Critical Care. Because they focused on the cardiovascular system and its support, we summarize them here. In particular, these papers highlighted the management of refractory septic shock, extracorporeal support, outcome markers in sepsis, and outcome after cardiac arrest

    Magnetism and half-metallicity at the O surfaces of ceramic oxides

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    The occurence of spin-polarization at ZrO2_{2}, Al2_{2}O3_{3} and MgO surfaces is proved by means of \textit{ab-initio} calculations within the density functional theory. Large spin moments, as high as 1.56 μB\mu_B, develop at O-ended polar terminations, transforming the non-magnetic insulator into a half-metal. The magnetic moments mainly reside in the surface oxygen atoms and their origin is related to the existence of 2p2p holes of well-defined spin polarization at the valence band of the ionic oxide. The direct relation between magnetization and local loss of donor charge makes possible to extend the magnetization mechanism beyond surface properties

    A trial of hyperglycemic control in pediatric intensive care.

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    Follow-up monitoring in a cat with leishmaniosis and coinfections with Hepatozoon felis and ‘Candidatus Mycoplasma haemominutum’

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    Case summary A 6-year-old female neutered domestic shorthair cat from Cyprus was presented with multiple ulcerated skin nodules. Cytology and histopathology of the lesions revealed granulomatous dermatitis with intracytoplasmic organisms, consistent with amastigotes of Leishmania species. Biochemistry identified a mild hyperproteinaemia. Blood extraction and PCR detected Leishmania species, Hepatozoon species and ‘Candidatus Mycoplasma haemominutum’ (CMhm) DNA. Subsequent sequencing identified Hepatozoon felis. Additionally, the rRNA internal transcribed spacer 1 locus of Leishmania infantum was partially sequenced and phylogeny showed it to cluster with species derived from dogs in Italy and Uzbekistan, and a human in France. Allopurinol treatment was administered for 6 months. Clinical signs resolved in the second month of treatment with no deterioration 8 months post-treatment cessation. Quantitative PCR and ELISA were used to monitor L infantum blood DNA and antibody levels. The cat had high L infantum DNA levels pretreatment that gradually declined during treatment but increased 8 months post-treatment cessation. Similarly, ELISA revealed high levels of antibodies pretreatment, which gradually declined during treatment and increased slightly 8 months post-treatment cessation. The cat remained PCR positive for CMhm and Hepatozoon species throughout the study. There was no clinical evidence of relapse 24 months post-treatment. Relevance and novel information To our knowledge, this is the first clinical report of a cat with leishmaniosis with H felis and CMhm coinfections. The high L infantum DNA levels post-treatment cessation might indicate that although the lesions had resolved, prolonged or an alternative treatment could have been considere
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