RESUMO
The design of new reductive routes to low oxidation state aluminium (Al) compounds offers the opportunity to better understand redox processes at the metal centre and develop reactivity accordingly. Here, a monomeric AlI compound acts as a stoichiometric reducing agent towards a series of AlIII dihydrides, leading to the formation of new low oxidation state species including symmetric and asymmetric dihydrodialanes, and a masked dialumene. These compounds are formed by a series of equilibrium processes involving AlI , AlII and AlIII species and product formation can be manipulated by fine-tuning the reaction conditions. The transient formation of monomeric AlI compounds is proposed: this is shown to be energetically viable by computational (DFT) investigations and reactivity studies show support for the formation of AlI species. Importantly, despite the potential for the equilibrium mixtures to lead to ill-defined reactivity, controlled reactivity of these low oxidation state species is observed.
RESUMO
The mechanism of the aluminum-mediated hydroboration of terminal alkynes was investigated using a series of novel aluminum amidinate hydride and alkyl complexes bearing symmetric and asymmetric ligands. The new aluminum complexes were fully characterized and found to facilitate the formation of the (E)-vinylboronate hydroboration product, with rates and orders of reaction linked to complex size and stability. Kinetic analysis and stoichiometric reactions were used to elucidate the mechanism, which we propose to proceed via the initial formation of an Al-borane adduct. Additionally, the most unstable complex was found to promote decomposition of the pinacolborane substrate to borane (BH3), which can then proceed to catalyze the reaction. This mechanism is in contrast to previously reported aluminum hydride-catalyzed hydroboration reactions, which are proposed to proceed via the initial formation of an aluminum acetylide, or by hydroalumination to form a vinylboronate ester as the first step in the catalytic cycle.
RESUMO
BACKGROUND: Hospital clinicians have had to rapidly develop expertise in managing the clinical manifestations of COVID-19 including symptoms common at the end of life, such as breathlessness and agitation. There is limited evidence exploring whether end-of-life symptom control in this group requires new or adapted guidance. AIM: To review whether prescribing for symptom control in patients dying with COVID-19 adhered to existing local guidance or whether there was deviation which may represent a need for revised guidance or specialist support in particular patient groups. DESIGN/SETTING: A retrospective review of the electronic patient record of 61 hospital inpatients referred to the specialist palliative care team with swab-confirmed COVID-19 who subsequently died over a 1-month period. Intubated patients were excluded. RESULTS: In all, 83% (40/48) of patients were prescribed opioids at a starting dose consistent with existing local guidelines. In seven of eight patients where higher doses were prescribed, this was on specialist palliative care team advice. Mean total opioid dose required in the last 24 h of life was 14 mg morphine subcutaneous equivalent, and mean total midazolam dose was 9.5 mg. For three patients in whom non-invasive ventilation was in place higher doses were used. CONCLUSION: Prescription of end-of-life symptom control drugs for COVID-19 fell within the existing guidance when supported by specialist palliative care advice. While some patients may require increased doses, routine prescription of higher starting opioid and benzodiazepine doses beyond existing local guidance was not observed.
Assuntos
Biofarmácia/estatística & dados numéricos , Infecções por Coronavirus/tratamento farmacológico , Delírio/tratamento farmacológico , Dispneia/tratamento farmacológico , Pneumonia Viral/tratamento farmacológico , Guias de Prática Clínica como Assunto , Assistência Terminal/métodos , Assistência Terminal/normas , Adulto , Idoso , Idoso de 80 Anos ou mais , Analgésicos Opioides/uso terapêutico , Betacoronavirus , COVID-19 , Feminino , Humanos , Hipnóticos e Sedativos/uso terapêutico , Masculino , Midazolam/uso terapêutico , Pessoa de Meia-Idade , Morfina/uso terapêutico , Pandemias , Estudos Retrospectivos , SARS-CoV-2RESUMO
The synthesis and isolation of novel low oxidation state aluminium (Al) compounds has seen relatively slow progress over the 30 years since such species were first isolated. This is largely due to the significant challenges in isolating these thermodynamically unstable compounds. Despite challenges with isolation, their reactivity has been widely explored and they have been utilized in a wide range of processes including the activation of strong chemicals bonds, as ligands to transition metals and in the formation of heterobimetallic M-M compounds. As such, attempts to isolate novel low oxidation state Al compounds have continued in earnest and in the last few years huge advances have been made. In this review we highlight the remarkable recent developments in the low oxidation state chemistry of aluminium and discuss the variety of new reactions these compounds have made possible.
RESUMO
BACKGROUND: Patients with end-stage renal disease (ESRD) experience a significant symptom burden and have complex needs. However, involvement of specialist palliative care (SPC) services with these patients has previously been shown to be limited. This study assesses the current provision of and access to SPC services for ESRD patients in the UK and considers how the provision has evolved over recent years. METHODS: A questionnaire was sent to the lead clinician for all UK adult hospital, hospice and community SPC services, identified from the Hospice and Palliative Care Directory 2008. Non-responders were mailed again after 5 weeks. Descriptive statistics and qualitative thematic analysis were performed. RESULTS: Three hundred and eighteen of 611 (52%) questionnaires were returned. Ninety-six per cent stated that SPC services have a role in caring for patients with ESRD. Two hundred and eighty-one of 318 (88%) accepted referrals, and 185 of 281 (66%) reported that 'none or few were referred'. Only 7% and 17% of respondents used specific ESRD referral and treatment guidelines, respectively; whereas 79% used the Liverpool Care Pathway for the Dying Patient. Seven per cent undertook joint renal and SPC multi-disciplinary team (MDT) meetings, and 3% held joint out-patient clinics. Forty percent of respondents proposed initiatives to improve palliative care for ESRD patients, with mutual education and collaborative working being key themes for improvement. CONCLUSIONS: The majority of SPC services accept ESRD patients, but limited numbers are referred. Respondents indicated that this barrier could be addressed by closer collaboration and better communication and education between renal and SPC services. Other initiatives to enable delivery of SPC to increased numbers of ESRD patients include the use of specific referral and clinical care guidelines and expansion of joint MDT meetings and out-patient clinics.