12 research outputs found
Synthesis of 2-hydroxy-3-methylbut-3-enyl substituted coumarins and xanthones as natural products. Application of the Schenck ene reaction of singlet oxygen with ortho-prenylphenol precursors
Application of our original photooxidation–reduction methodology to prenylated dihydroxycoumarin and trihydroxyxanthone compounds led to the corresponding ortho-(2-hydroxy-3-methylbut-3-enyl)phenol derivatives with yields ranging from 8 to 65%. In most of the reported experiments, the oxidation products distribution, after the photooxygenation step, was controlled by the competition between the large group effect and the stabilising phenolic assistance effect. We also showed that ortho-(3-hydroxy-3-methylbut-1-enyl)phenol derivatives could be considered as biogenetic precursors of 2,2-dimethylbenzopyranic structures
First 2-Hydroxy-3-Methylbut-3-Enyl Substituted Xanthones Isolated From Plants: Structure Elucidation, Synthesis and Antifungal Activity
Two new 2-hydroxy-3-methylbut-3-enyl substituted xanthones, ( - )-caledol 1 and ( - )-dicaledol 2 were isolated from a dichloromethane extract of the leaves of Calophyllum caledonicum (Clusiaceae). Compounds 1 and 2 are the first 2-hydroxy-3-methylbut-3-enyl substituted xanthones isolated from natural source. Their structures were elucidated by means of combined analytical methods including HRFABMS, 1D and 2D NMR spectroscopies and also confirmed by total synthesis using biomimetic ortho -prenylphenols photooxygenation ( 1 O 2 ) as a key step. The antifungal activity against Aspergillus fumigatus is reported
Controlled pinewood fractionation with supercritical ethanol: A prerequisite toward pinewood conversion into chemicals and biofuels
SSCI-VIDE+CDFA+FRA:NESInternational audienceThe objective of this work was to investigate the ability of supercritical (SC) ethanol conditions to attack preferentially the lignin fraction against the carbohydrate fraction and their effects on the product distribution among gases, light products, bio-oils, and chars. In this study, the conversion of each pinewood component was determined by the analysis of solid residues to quantify cellulose, hemicellulose, lignin, and char contents. It is shown that, by tuning the temperature, hemicellulose and lignin are already transformed in subcritical ethanol conditions, lignin being more reactive than hemicellulose. In contrast, native wood cellulose is recalcitrant to liquefaction in SC ethanol near the critical point (Tc = 241 °C and Pc = 61 bar), but 20% of native wood cellulose is converted in SC ethanol at 280 °C. Besides, the severity of the conditions, in terms of temperature and treatment time, does not significantly influence the yields of gases, light products, and bio-oils but strongly enhances char formation. Interestingly, the increase in SC ethanol density does not change the conversion of biomass components but has a marked effect on bio-oil yield and prevents char formation. The optimum fractionation conditions to convert the lignin component, while keeping unattacked the cellulose fraction with a minimum formation of char, are dense SC ethanol, at 250 °C for 1 h, in batch conditions. However, although lignin is more reactive than hemicellulose under these conditions, these fractions are converted, in a parallel way, to around 50% and 60%, respectively
Thermochemical fractionation/liquefaction of lignocellulosic biomass in supercritical ethanol: Influence of the experimental parameters
International @ CDFA+NBU:PFO:FRA:NESInternational audienceNon
Adequacy of hospitalizations in a highly complex pediatric hospital
Introducción. Para evaluar los pacientes internados sin necesidad, la herramienta de mayor utilidad para detectarlo, es el Protocolo de evaluación de la adecuación en pediatría o Pediatrics Appropriateness Evaluation Protocol (PAEP). El objetivo primario de este estudio es cuantificar los ingresos inadecuados que se producen en el área de un hospital pediátrico de la Ciudad de Buenos Aires, Argentina, el Hospital de Niños Ricardo Gutiérrez utilizando utilizando el PAEP. Población y métodos. Durante los meses de mayo y junio del año 2015 se analizaron un total de 441 niños menores de 18 años al ingreso, internados durante todos los días de la semana. Se recabaron datos filiatorios, diagnóstico, protocolo PAEP y necesidad de un hospital de alta complejidad. Resultados. La edad media de los pacientes internados fue 4,63 años (SD 4,9). Según la regla PAEP los criterios de internación fueron adecuados en 411/432 (95%), e inadecuados en 21/432 (4,8%). Esto fue inferior a la media de las series publicadas sobre criterios de internación. 151 (34%) podrían haberse internado en un hospital de baja complejidad. Los pacientes de menor complejidad según la necesidad de atención requerida, tenían una edad media de 2,3 años y los de mayor complejidad una edad media de 5.79 años. De acuerdo a la probabilidad de internación inadecuada las patologías asociadas más frecuentes fueron purpura trombótica inmune (PTI), gastroenteritis, anemia para estudio y estados convulsivos. Las patologías que tuvieron mayor probabilidad de requerir baja complejidad fueron, en orden decreciente síndromes bronquiales obstructivos agudos, patologías renales, neumonías y celulitis. Conclusiones. Se encontró una baja tasa de internación inadecuada en relación a otras series de casos con regla PAEP. Un tercio de la muestra podría haberse internado en un hospital general.Introduction. In order to evaluate the hospitalized patients without requirement the most useful tool, it is the Pediatrics Appropriateness Evaluation Protocol(PAEP). The primary objective of this study is to quantify the inadequate income that occurs in the clinical area in this Hospital using PAEP. Population and methods. Analyzed at admission, during the months of May and June of the year 2015, a total of 441 children under the age of 18 years were on all days of the week. A questionnaire with filiatory data, diagnosis, PAEP protocol and need for a hospital of high complexity was completed. Results. The mean age was 4.63 years (SD 4.9). According to the PAEP rule the adequate hospitalization criteria in 411/432 (95%), inadequate in 21/432 (4.8%). This was lower than the average of published series on admission criteria. 151 (34%) could have been hospitalized in a General Hospital. Patients of less complexity according to the need for required care had a mean age of 2.3 years and those of greater complexity had an average age of 5.79 years. According to the probability of inadequate hospitalization, the most frequent associated pathologies were immune thrombotic purpura (ITP), gastroenteritis, anemia for study and seizures. The pathologies that were most likely to require low complexity were, in descending order SBOA, renal pathologies, pneumonias and cellulitis. Conclusions. We found low rate of inadequate hospitalization with compare to other cases records with PAEP rules. A third of the sample may have been admitted to a general hospital.Fil: Bilkis, M.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; ArgentinaFil: Molise, C. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; ArgentinaFil: Stacha, P. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; ArgentinaFil: García Bournissen, Facundo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; ArgentinaFil: Camberosa, M.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; ArgentinaFil: Rodriguez, A.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; ArgentinaFil: Martin, G.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; ArgentinaFil: Dartiguelongue, Josefina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; ArgentinaFil: Candido, G.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; ArgentinaFil: Mavrakis, P.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; ArgentinaFil: Sagradini, S.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; ArgentinaFil: Fiorentino, J.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; Argentin
Spatial distribution of meteorological parameters around 900 hPa level over the Arabian Sea and Indian Ocean regions during the Intensive Field Phase - 99 of the INDOEX programme
During the IFP-99 of the INDOEX programme, an Indo-French joint scientific team conducted 17 constant
balloon flights from Goa mainly to study the various features of the continental air mass flow from
the Indian subcontinent towards the ITCZ induced by the NE winter circulation and thereby to derive the
transportation of the continental aerosols and trace gases to the Indian Ocean regions. Out of the 17
flights, 15 were successful. Data obtained from the Constant Altitude Balloon Experiment are analysed
to study the features of the wind fields and thermodynamic parameters of the marine boundary layer at
~ 900 hPa level over the oceanic regions adjoining west-coast of Peninsular India. From the balloon
co-ordinates, the instantaneous vector wind as well as its zonal and meridional components are estimated.
Also estimated are the ambient air temperature and relative humidity at 30 min interval. These data are examined for the spatial features. Mean wind showed presence of three broad flow channels, from India, Africa and West Asia, that are important in influencing the Arabian Sea environment and provide potential pathways for transport of continental pollutants. Variations associated with the M.) oscillations
are present in the zonal wind, close to the equator. On several occasions wind showed occurrence of eddies with anticyclonic circulation having temporal scales of one to five days. Temperature and humidity structure showed large dry areas over the Arabian Sea associated with the flow channels. Rather humid regions occur over coastal India and near the ITCZ
Optimization of uranium separation using silica gel impregnated tri-n-butyl phosphate for alpha spectrometry analysis of soil samples
An unexpected host for the endangered giant freshwater pearl mussel Margaritifera auricularia (Spengler, 1793) as a conservation tool
International audienc