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This review covers all aspects of 9-borafluorene chemistry, from the first attempted synthesis in 1960 to the present. This class of molecules consists of a tricyclic system featuring a central antiaromatic BC4 ring with two fused arene groups. The synthetic routes to all 9-borafluorenes and their adducts are presented. The Lewis acidity and photophysical properties outlined demonstrate potential utility as sensors and in electronic materials. The reactivity of borafluorenes reveals their prospects as reagents for the synthesis of other boron-containing molecules. The appealing traits of 9-borafluorenes have stimulated investigations into analogues that bear different aromatic groups fused to the central BC4 ring. Finally, we offer our views on the challenges and future of borafluorene chemistry.
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Fluorescent probes are increasingly used as reporter molecules in a wide variety of biophysical experiments, but when designing new compounds it can often be difficult to anticipate the effect that changing chemical structure can have on cellular localisation and fluorescence behaviour. To provide further chemical rationale for probe design, a series of donor-acceptor diphenylacetylene fluorophores with varying lipophilicities and structures were synthesised and analysed in human epidermal cells using a range of cellular imaging techniques. These experiments showed that, within this family, the greatest determinants of cellular localisation were overall lipophilicity and the presence of ionisable groups. Indeed, compounds with high log D values (>5) were found to localise in lipid droplets, but conversion of their ester acceptor groups to the corresponding carboxylic acids caused a pronounced shift to localisation in the endoplasmic reticulum. Mildly lipophilic compounds (log D = 2-3) with strongly basic amine groups were shown to be confined to lysosomes i.e. an acidic cellular compartment, but sequestering this positively charged motif as an amide resulted in a significant change to cytoplasmic and membrane localisation. Finally, specific organelles including the mitochondria could be targeted by incorporating groups such as a triphenylphosphonium moiety. Taken together, this account illustrates a range of guiding principles that can inform the design of other fluorescent molecules but, moreover, has demonstrated that many of these diphenylacetylenes have significant utility as probes in a range of cellular imaging studies.
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Corantes FluorescentesRESUMO
Homoallylic boronate carboxylate esters derived from unsaturated aldehydes via an imination, ß-borylation, imine hydrolysis, and Wittig trapping sequence, were subjected to a second boryl addition to give 1,3-diborylated carboxylate esters. Control of the absolute and relative stereochemistry of the two new 1,3-stereogenic centers was achieved through: (1) direct chiral catalyst controlled asymmetric borylation of the first stereocenter on the unsaturated imine with high e.e.; and (2) a double diastereoselectively controlled borylation of an unsaturated ester employing a chiral catalyst to largely overcome directing effects from the first chiral boryl center to give poor (mismatched) to good (matched) diastereocontrol. Subsequently, the two C-B functions were transformed into C-O systems to allow unambiguous stereochemical assignment of the two borylation reactions involving oxidation and acetal formation.
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In the Balearic Islands, as in other areas in southern Europe, there are a significant proportion of asymptomatic Leishmania infantum-infected blood donors. Theoretically, these donors may represent an important challenge for blood transfusion safety. However, despite an active search of multiply transfused patients, there have been, so far, no cases of transfusion-transmitted leishmaniasis (TTL) in our region. On the other hand, there is scarce evidence of the TTL in the literature. A review of asymptomatic Leishmania-infected blood donors' studies in endemic areas and TTL reports published in the English literature were performed, to ascertain the factors that determine the real risk of transfusion transmission of Leishmania.
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Transfusão de Sangue , Patógenos Transmitidos pelo Sangue , Leishmania infantum , Leishmaniose Visceral , Doadores de Sangue , Feminino , Humanos , Leishmaniose Visceral/sangue , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/transmissão , Masculino , Fatores de Risco , Espanha/epidemiologiaRESUMO
The ß-borylation reaction of α,ß-unsaturated aldehyde-derived imines, formed in situ, has been studied using a one-pot methodology, as a route to ß-boryl aldehydes. The instability of the ß-boryl aldehydes meant that derivatisation was required and routes to both acetal derivatives and homoallylic boronates were examined. ß-Boryl acetals were also found to be unstable, however, the formation of homoallylic boronate derivatives using an in situ imine hydrolysis-Wittig olefination protocol was found to be suitable, resulting in an efficient synthesis with high enantiomeric excesses.
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OBJECTIVES: To evaluate short-term mortality in people transferred from aged care homes for treatment in a hospital emergency department (ED) and to analyze factors associated with mortality. MATERIAL AND METHODS: Multicenter study of a random sample of retrospective data of patients treated in 5 EDs in Catalonia in 2017. The patients were over the age of 65 years and lived in residential care facilities. In addition to short-term mortality (in the ED or within 30 days of discharge), we analyzed sociodemographic characteristics, prior functional and cognitive status, multimorbidity, triage level on arrival, length of stay in the ED, and hospital admission. Odds ratios (ORs) for factors associated with short-term mortality were calculated by multivariate regression analysis. RESULTS: A total of 2444 ED admissions were analyzed. The patients' mean (SD) age was 85.9 (7.1) years, and 67.7% .were women. Short-term mortality (in 15.5%) was associated with age >90 years (OR, 1.50; 95% CI, 1.5-1.95 years), a Charlson index >2 (OR, 1.47; 95% CI, 1.14-1.90), and dependency assessed as moderate (OR, 1.50; 95% CI, 1.03- 2.20) or severe (OR, 2.56; 95% CI, 1.84-3.55). Other associated factors were a higher level of urgency on triage, duration of ED stay, and hospital admission. CONCLUSION: Aged residents with the characteristics associated with short-term mortality could benefit from interventions for potentially avoiding unnecessary transfers to an ED, and from the implementation of comprehensive geriatric care within the ED. This could be useful to support good quality of care at the end of life.
OBJETIVO: Evaluar la frecuencia y los factores asociados con la mortalidad a corto plazo de personas que viven en residencias tras ingreso en urgencias. METODO: Análisis retrospectivo multicéntrico de una muestra aleatoria de admisiones de personas $ 65 años que viven en residencias en cinco servicios de urgencias de Cataluña, a lo largo de 2017. Se analizaron características sociodemográficas, el estado funcional y cognitivo previo, multimorbilidad, nivel de triaje de las urgencias, duración de la estancia en urgencias, hospitalización y mortalidad a corto plazo (en urgencias o en los 30 días posteriores al alta). Se utilizó un análisis de regresión multivariante para investigar los factores asociados con la mortalidad a corto plazo. RESULTADOS: Se analizaron 2.444 admisiones en urgencias, con una edad media de 85,9 (DE 7,1) años, 67,7% mujeres. La mortalidad a corto plazo (15,5%) se asoció con una edad > 90 años (OR 1,50; IC 95%: 1,5-1,95), un índice de Charlson > 2 (OR 1,47; IC 95%: 1,14-1,90), y un grado de dependencia moderado (OR 1,50; IC 95%: 1,03-2,20) y grave (OR 2,56; IC 95%: 1,84-3,55). También se asoció con un mayor nivel de triaje de la urgencia, duración de la estancia en urgencias e ingreso en planta de hospitalización. CONCLUSIONES: Los ancianos residentes con las características descritas podrían beneficiarse especialmente de intervenciones dirigidas a la prevención de traslados potencialmente innecesarios a urgencias y a la implementación de una atención integral geriátrica dentro de los servicios de urgencias, a fin de garantizar una buena calidad de los cuidados en fases finales de la vida.
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Serviços Médicos de Emergência , Hospitalização , Humanos , Feminino , Masculino , Estudos Retrospectivos , Serviço Hospitalar de Emergência , Alta do PacienteRESUMO
BACKGROUND: In the Balearic Islands, as in other areas of the Mediterranean basin, there is a significant proportion of asymptomatic Leishmania (L.) infantum-infected blood donors, who may represent an important threat to transfusion safety. The Balearic Islands blood bank, located in an area endemic for L. infantum, carried out a study of donors and patients to investigate the impact of this infectious disease on blood safety in the region. MATERIALS AND METHODS: Twenty asymptomatic Leishmania-infected blood donors were followed-up between 2008 and 2011 to investigate the evolution of Leishmania infection in asymptomatic carriers. Their blood was periodically tested for anti-Leishmania antibodies by western blot and for Leishmania DNA by quantitative polymerase chain reaction (qPCR). Additionally, the prevalence of L. infantum infection was investigated in a group of 68 multiply transfused patients to ascertain the risk of transfusion-transmitted leishmaniasis (TTL) in the region, taking into account regular blood component production practices such as pre-storage leucodepletion and pathogen reduction technology. RESULTS: All 20 donors remained asymptomatic over the study period (2008-2011). Most donors had repeatedly positive qPCR results, either persistently or intermittently, but showed no symptoms of Leishmaniasis. Levels of parasitaemia were remarkably low in asymptomatic donors, with values ≤1 parasite/mL. Despite multiple transfusions received over 15 years, no transfused patient studied was infected with L. infantum. DISCUSSION: L. infantum-infected donors can remain asymptomatic for at least 3 years. In our region, no cases of TTL were detected, despite an active search in multiply transfused patients. This seems to be related to two independent variables: (i) a low concentration of the parasite in the peripheral blood of asymptomatic carriers and (ii) the application of methods with proven efficacy against TTL, such as leucodepletion and pathogen reduction technology.
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Bancos de Sangue , Doadores de Sangue , Transfusão de Sangue , DNA de Protozoário/sangue , Seleção do Doador , Leishmania infantum , Leishmaniose Visceral , Adulto , Doenças Endêmicas , Feminino , Humanos , Leishmaniose Visceral/sangue , Leishmaniose Visceral/transmissão , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase em Tempo Real , EspanhaRESUMO
A one-pot synthesis of chiral amino alcohols from α,ß-unsaturated aldehydes is reported which circumvents competitive 1,2- versus 1,4-boryl addition, by means of using a sterically hindered amine-derived imine. In addition to the complete chemoselectivity, modification of the Cu(I) catalyst with readily available chiral diphosphines, such as (R)-DM-BINAP, gave the 1,4-boryl addition products with high levels of asymmetric induction.