160 research outputs found

    Accessible heavier s-block dihydropyridines : structural elucidation and reactivity of isolable molecular hydride sources

    Get PDF
    The straightforward metathesis of 1-lithio-2-tbutyl-1,2-dihydropyridine using metal tert-butoxide (Na/K) has resulted in the first preparation and isolation of a series of heavier alkali metal dihydropyridines. By employing donors, TMEDA, PMDETA and THF, five new metallodihydropyridine compounds were isolated and fully characterised. Three distinct structural motifs have been observed; a dimer, a dimer of dimers and a novel polymeric dihydropyridylpotassium compound, and the influence of cation π-interactions therein has been discussed. Thermal volatility analysis has shown that these complexes have the potential to be used as simple isolable sodium or potassium hydride surrogates, which is confirmed in test reactions with benzophenone

    Developing lithium chemistry of 1,2-dihydropyridines : from kinetic intermediates to isolable characterized compounds

    Get PDF
    Generally considered kinetic intermediates in addition reactions of alkyllithiums to pyridine, 1-lithio-2-alkyl-1,2-dihydropyridines have been rarely isolated or characterized. This study develops their "isolated" chemistry. By a unique stoichiometric (that is 1:1, alkyllithium:pyridine ratios) synthetic approach using tridentate donors we show it is possible to stabilize and hence crystallize monomeric complexes where alkyl is tert-butyl. Theoretical calculations probing the donor-free parent tert-butyl species reveal 12 energetically similar stereoisomers in two distinct cyclotrimeric (LiN)3 conformations. NMR studies (including DOSY spectra) and thermal volatility analysis compare new sec-butyl and iso-butyl isomers showing the former is a hexane soluble efficient hydrolithiation agent converting benzophenone to lithium diphenylmethoxide. Emphasizing the criticalness of stoichiometry, reaction of nBuLi/Me6TREN with two equivalents of pyridine results in non-alkylated 1-lithio-1,4-dihydropyridine·Me6TREN and 2-n-butylpyridine, implying mechanistically the kinetic 1,2-n-butyl intermediate hydrolithiates the second pyridine

    Adding Psychological Value to Heritage Tourism Experiences

    Get PDF
    This study employed an under-utilized methodology known as the Hierarchical Value Map (HVM) technique to explore the underlying motives and needs of visitors to a heritage site. Drawing from a small sample of visitors to a preserved 18th century plantation, the analysis revealed that most respondents were looking for a satisfying leisure experience where pleasure and learning are complementary. In addition the results support the notion that there is a specialized tourist segment (e.g., heritage tourists) that as a group has unique motives and needs. Implications for both optimizing the visitors experience as well as projecting an effective image and marketing communications are discussed

    Mechanism of succinate efflux upon reperfusion of the ischaemic heart.

    Get PDF
    AIMS: Succinate accumulates several-fold in the ischaemic heart and is then rapidly oxidized upon reperfusion, contributing to reactive oxygen species production by mitochondria. In addition, a significant amount of the accumulated succinate is released from the heart into the circulation at reperfusion, potentially activating the G-protein-coupled succinate receptor (SUCNR1). However, the factors that determine the proportion of succinate oxidation or release, and the mechanism of this release, are not known. METHODS AND RESULTS: To address these questions, we assessed the fate of accumulated succinate upon reperfusion of anoxic cardiomyocytes, and of the ischaemic heart both ex vivo and in vivo. The release of accumulated succinate was selective and was enhanced by acidification of the intracellular milieu. Furthermore, pharmacological inhibition, or haploinsufficiency of the monocarboxylate transporter 1 (MCT1) significantly decreased succinate efflux from the reperfused heart. CONCLUSION: Succinate release upon reperfusion of the ischaemic heart is mediated by MCT1 and is facilitated by the acidification of the myocardium during ischaemia. These findings will allow the signalling interaction between succinate released from reperfused ischaemic myocardium and SUCNR1 to be explored

    Use of digital measurement of medication adherence and lung function to guide the management of uncontrolled asthma (INCA Sun):a multicentre, single-blinded, randomised clinical trial

    Get PDF
    BACKGROUND: The clinical value of using digital tools to assess adherence and lung function in uncontrolled asthma is not known. We aimed to compare treatment decisions guided by digitally acquired data on adherence, inhaler technique, and peak flow with existing methods.METHODS: A 32-week prospective, multicentre, single-blinded, parallel, randomly controlled trial was done in ten severe asthma clinics across Ireland, Northern Ireland, and England. Participants were 18 years or older, had uncontrolled asthma, asthma control test (ACT) score of 19 or less, despite treatment with high-dose inhaled corticosteroids, and had at least one severe exacerbation in the past year despite high-dose inhaled corticosteroids. Patients were randomly assigned in a 1:1 ratio to the active group or the control group, by means of a computer-generated randomisation sequence of permuted blocks of varying sizes (2, 4, and 6) stratified by fractional exhaled nitric oxide (FeNO) concentration and recruitment site. In the control group, participants were masked to their adherence and errors in inhaler technique data. A statistician masked to study allocation did the statistical analysis. After a 1-week run-in period, both groups attended three nurse-led education visits over 8 weeks (day 7, week 4, and week 8) and three physician-led treatment adjustment visits at weeks 8, 20, and 32. In the active group, treatment adjustments during the physician visits were informed by digital data on inhaler adherence, twice daily digital peak expiratory flow (ePEF), patient-reported asthma control, and exacerbation history. Treatment was adjusted in the control group on the basis of pharmacy refill rates (a measure of adherence), asthma control by ACT questionnaire, and history of exacerbations and visual management of inhaler technique. Both groups used a digitally enabled Inhaler Compliance Assessment (INCA) and PEF. The primary outcomes were asthma medication burden measured as proportion of patients who required a net increase in treatment at the end of 32 weeks and adherence rate measured in the last 12 weeks by area under the curve in the intention-to-treat population. The safety analyses included all patients who consented for the trial. The trial is registered with ClinicalTrials.gov, NCT02307669 and is complete.FINDINGS: Between Oct 25, 2015, and Jan 26, 2020, of 425 patients assessed for eligibility, 220 consented to participate in the study, 213 were randomly assigned (n=108 in the active group; n=105 in the control group) and 200 completed the study (n=102 in the active group; n=98 in the control group). In the intention-to-treat analysis at week 32, 14 (14%) active and 31 (32%) control patients had a net increase in treatment compared with baseline (odds ratio [OR] 0·31 [95% CI 0·15-0·64], p=0·0015) and 11 (11%) active and 21 (21%) controls required add-on biological therapy (0·42 [0·19-0·95], p=0·038) adjusted for study site, age, sex, and baseline FeNO. Three (16%) of 19 active and 11 (44%) of 25 control patients increased their medication from fluticasone propionate 500 μg daily to 1000 μg daily (500 μg twice a day; adjusted OR 0·23 [0·06-0·87], p=0·026). 26 (31%) of 83 active and 13 (18%) of 73 controls reduced their medication from fluticasone propionate 1000 μg once daily to 500 μg once daily (adjusted OR 2·43 [1·13-5·20], p=0·022. Week 20-32 actual mean adherence was 64·9% (SD 23·5) in the active group and 55·5% (26·8) in the control group (between-group difference 11·1% [95% CI 4·4-17·9], p=0·0012). A total of 29 serious adverse events were recorded (16 [55%] in the active group, and 13 [45%] in the control group), 11 of which were confirmed as respiratory. None of the adverse events reported were causally linked to the study intervention, to the use of salmeterol-fluticasone inhalers, or the use of the digital PEF or INCA.INTERPRETATION: Evidence-based care informed by digital data led to a modest improvement in medication adherence and a significantly lower treatment burden.FUNDING: Health Research Board of Ireland, Medical Research Council, INTEREG Europe, and an investigator-initiated project grant from GlaxoSmithKline.</p

    Unworking Milton: Steps to a Georgics of the Mind

    Full text link
    Traditionally read as a poem about laboring subjects who gain power through abstract and abstracting forms of bodily discipline, John Milton’s Paradise Lost (1667, 1674) more compellingly foregrounds the erotics of the Garden as a space where humans and nonhumans intra-act materially and sexually. Following Christopher Hill, who long ago pointed to not one but two revolutions in the history of seventeenth-century English radicalism—the first, ‘the one which succeeded[,] . . . the protestant ethic’; and the second, ‘the revolution which never happened,’ which sought ‘communal property, a far wider democracy[,] and rejected the protestant ethic’—I show how Milton’s Paradise Lost gives substance to ‘the revolution which never happened’ by imagining a commons, indeed a communism, in which human beings are not at the center of things, but rather constitute one part of the greater ecology of mind within Milton’s poem. In the space created by this ecological reimagining, plants assume a new agency. I call this reimagining ‘ecology to come.

    Torture and the UK’s “war on asylum”: medical power and the culture of disbelief

    Get PDF
    When the now ‘iconic’ images of shackled, humiliated and dehumanised detainees in the Abu Ghraib prison complex in Iraq were broadcast globally, in the mid-2000s, the relationship between medical power and torture in the “war on terror” was also thrust sharply into focus. Graphic images of coalition troops photographing and posing in front of hooded, naked prisoners forced into a “human pyramid”, and of people made to wear animal collars, indicated a regime in which degradation had a defining role. The photograph of a soldier gloating over the corpse of a man who had died as a result of torture was just one picture of a network of interrogation camps in which detention by coalition forces could be fatal. Yet if there were any expectations that the presence of medical personnel may have checked this violence, these were shattered by the fact that clinicians – in some cases at least – were integral to its practice. «It is now beyond doubt that Armed Forces physicians, psychologists, and medics were active and passive partners in the systematic neglect and abuse of war on terror prisoners», wrote Steven Miles in 2009 (Miles 2009, X). And as he continued, this involved providing interrogators «with medical information to use in setting the nature and degree of physical and psychological abuse during interrogations». It involved monitoring «interrogations to devise ways to break prisoners down or to keep them alive». It involved pathologists holding back death certificates and autopsy reports in order to minimise the number of fatalities or cover up torture-related deaths as deaths by natural causes (Ibid). Procedures including «cramped confinement, dietary manipulation, sleep deprivation, and waterboarding» were among the practices that were «at times (…) legally sanctioned due to medical supervision» in the context of the “war on terror”, according to Hoffman (2011, 1535). He continued to suggest that doctors are not just important to «modern torture methods», they are «irreplaceable». In this context, the “war on terror” is no aberration. As the revolutionary psychoanalyst and philosopher Frantz Fanon documented in 1959, for example, certain medical practitioners had an integral role in the military occupation of Algeria, and «There are, for instance, psychiatrists … known to numerous prisoners», he suggested, «who have given electric shock treatments to the accused and have questioned them during the waking phase, which is characterized by a certain confusion, a relaxation of resistance, a disappearance of the person's defences.» (Fanon 1959/1965, 138). Indeed, in his analysis of the Algerian revolution, he discussed how resistance to and struggles over the meanings of medical power were integral to the revolution itself. However, while the role of medical power in the practice of torture has been subjected to sustained critique in the context of the “war on terror”, what follows examines the relationship between medical power and torture in the context of what has been depicted – metaphorically – as another (although to some extents related) “war”: the “war” on asylum. According to the UNHCR (2017, 3), between 5 and 35 per cent of those asylum seekers who have been granted refugee status have survived torture. And focusing on the UK as a case study, this chapter examines the institutional and legal structures prohibiting torture and inhuman and degrading treatment, particularly as they apply to those subject to immigration control in this context. But further, it also examines the ideological and political conditions within which claims by those seeking asylum that they have been subjected to torture prior to arrival can be (and have been) ignored, downplayed and denied. It examines how medical expertise has frequently been undermined in the asylum process when this expertise is utilised to add weight to asylum seekers’ claims to have experienced torture. It examines how there have been attempts to narrow the definition of torture in ways which exclude people from the protections to which torture survivors are entitled. But it also explores the ways in which segments of the medical profession have been complicit in riding roughshod over existing safeguards to prevent further harm to those who have experienced torture, thus potentially compounding its effects. In particular, it examines claims that in certain contexts clinicians have administered dangerous “care” in order to ensure the removal of people from the UK, despite them claiming that they – or their family members – face serious harm and persecution on arrival as a result of this. In a historical discussion of medical involvement in torture, Giovanni Maio (2001, 1609) has noted that from its earliest incarnations one of the features of torture has been its use as an «oppressive instrument used in the preservation of power». Furthermore, whilst methods of torture have certainly «developed», and continue to do so, he argues, this «function» of torture is «especially relevant today». This chapter argues that the (mis)treatment of those in the UK who say they have been tortured, preserves and is bound up with a particular manifestation of state power: the aims, rationale and dictates of immigration control. Its claims are perhaps much more mundane than the forms of direct medical complicity in torture alluded to above. But they are nonetheless important. For it is argued that the acts of omission and commission documented in this chapter expose the tensions between the rights of certain “categories” of migrants to be afforded adequate clinical care on the one hand, and the goals and aims of immigration control itself on the other. This poses profound questions about the functions of clinical care and the ethical duties, responsibilities and obligations of clinicians, it is suggested. But as this chapter also crucially explores, this is a form of power that many within the medical profession have historically challenged, and continue to do so

    Models and model value in stochastic programming

    Full text link
    Finding optimal decisions often involves the consideration of certain random or unknown parameters. A standard approach is to replace the random parameters by the expectations and to solve a deterministic mathematical program. A second approach is to consider possible future scenarios and the decision that would be best under each of these scenarios. The question then becomes how to choose among these alternatives. Both approaches may produce solutions that are far from optimal in the stochastic programming model that explicitly includes the random parameters. In this paper, we illustrate this advantage of a stochastic program model through two examples that are representative of the range of problems considered in stochastic programming. The paper focuses on the relative value of the stochastic program solution over a deterministic problem solution.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44253/1/10479_2005_Article_BF02031741.pd

    In Support of a Patient-Driven Initiative and Petition to Lower the High Price of Cancer Drugs

    Get PDF
    Comment in Lowering the High Cost of Cancer Drugs--III. [Mayo Clin Proc. 2016] Lowering the High Cost of Cancer Drugs--I. [Mayo Clin Proc. 2016] Lowering the High Cost of Cancer Drugs--IV. [Mayo Clin Proc. 2016] In Reply--Lowering the High Cost of Cancer Drugs. [Mayo Clin Proc. 2016] US oncologists call for government regulation to curb drug price rises. [BMJ. 2015
    corecore