RESUMO
A cell-free enantioselective transformation of the carbon atom of CO2 has never been reported. In the urgent context of transforming CO2 into products of high value, the enantiocontrolled synthesis of chiral compounds from CO2 would be highly desirable. Using an original hybrid chemoenzymatic catalytic process, we report herein the reductive oligomerization of CO2 into C3 (dihydroxyacetone, DHA) and C4 (l-erythrulose) carbohydrates, with perfect enantioselectivity of the latter chiral product. This was achieved with the key intermediacy of formaldehyde. CO2 is first reduced selectively by 4e- by an iron-catalyzed hydroboration reaction, leading to the isolation and complete characterization of a new bis(boryl)acetal compound derived from dimesitylborane. In an aqueous buffer solution at 30 °C, this compound readily releases formaldehyde, which is then involved in selective enzymatic transformations, giving rise either (i) to DHA using a formolase (FLS) catalysis or (ii) to l-erythrulose with a cascade reaction combining FLS and d-fructose-6-phosphate aldolase (FSA) A129S variant. Finally, the nature of the synthesized products is noteworthy, since carbohydrates are of high interest for the chemical and pharmaceutical industries. The present results prove that the cell-free de novo synthesis of carbohydrates from CO2 as a sustainable carbon source is a possible alternative pathway in addition to the intensely studied biomass extraction and de novo syntheses from fossil resources.
RESUMO
In response to the outbreak of COVID-19, we set up a team to carry out sampling in the community. This enabled individuals to remain in self-isolation in their own homes and to prevent healthcare settings and services from being overwhelmed by admissions for sampling of suspected cases. There is evidence that this is a cost effective, safe and necessary service to complement COVID-19 testing in hospitals.
Assuntos
Técnicas de Laboratório Clínico , Infecções por Coronavirus/diagnóstico , Coronavirus/isolamento & purificação , Surtos de Doenças/prevenção & controle , Programas de Rastreamento/métodos , Pneumonia Viral/prevenção & controle , Doenças Assintomáticas , Betacoronavirus , COVID-19 , Teste para COVID-19 , Serviços de Saúde Comunitária/organização & administração , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/transmissão , Infecções por Coronavirus/virologia , Humanos , Pandemias , Isolamento de Pacientes , Pneumonia Viral/diagnóstico , Pneumonia Viral/epidemiologia , Pneumonia Viral/transmissão , Pneumonia Viral/virologia , Prática de Saúde Pública , Quarentena , SARS-CoV-2 , Escócia/epidemiologia , Fatores de TempoRESUMO
We conducted a systematic review of literature relating to videoconferencing in therapeutic interventions for chronic conditions. Two hundred articles were reviewed in detail, 35 of which were relevant to the study. Of these, eight were randomized controlled trials (RCTs) and the remainder were service evaluations, pilot studies and case studies. Two major themes emerged, relating specifically to videoconferencing: clinical outcomes and patient satisfaction. There were 14 studies which measured clinical outcomes of interventions for chronic conditions delivered by videoconferencing. A range of evidence, including four RCTs of high quality, indicates that interventions for a variety of conditions, including psychological and physical, delivered by videoconferencing produce similar outcomes to treatment delivered in-person. Evidence suggests that levels of patient satisfaction with telerehabilitation are high and that the formation of a good therapeutic alliance is possible. Several papers reported that clinical staff showed lower levels of satisfaction in using telerehabilitation than patients. It is feasible to use videoconferencing as a means of delivering therapeutic interventions for people with chronic conditions in rural communities.