122 research outputs found

    Characterization of extracts from the bark of the Gabon hazel tree (Coula edulis baill) for antioxidant, antifungal and anti-termite products

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    Chemical composition of the bark extracts ofCoula eduliswas inves-tigated tofind potential antioxidant, anti-termite and antifungal compounds whichcanfind useful applications in thefields of food, nutraceuticals, cosmetics or agro-chemical. Phytochemical screening revealed the presence of several groups ofactive molecules such as alkaloids, polyphenols,flavonoids, saponins and sterolsand/or terpenes in the different extracts. Total phenols, condensed tannins andfla-vonoids contents corroborated phytochemical screening. Gas chromatography-mass spectrometry (GC-MS) analysis revealed compounds in dichloromethaneextract different from those obtained with all the other solvents. Hexadecanoicand trans-9-octadecenoic acids, as well as stigmasterol andÎČ-sitosterol have beenidentified as the major compounds in the dichloromethane extract. Extractsobtained with acetone and toluene/ethanol mixture (2/1, v/v) indicated the pre-sence of few amounts of fatty acids and sugars, catechin in small amount andhuge amounts of phenolic acids like gallic and ellagic acids. The radical 2,2-diphenyl-1-picrylhydrazyle (DPPH) and the cationic radical 2,2'-azinobis(3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS+) were used for evaluation of antioxidantproperties of the different extracts. The dichloromethane extracts had a very lowantioxidant activity, while acetone and toluene/ethanol extracts presented EC50values similar to those of catechin and BHT used as reference antioxidant com-pounds. Effect of the different extracts of the bark ofC. edulison fungal growthinhibition indicated better inhibition of the mycelium growth of brown rot fungicompared to white rot fungi. Low anti-termite activities were recorded with theaqueous extracts, while stronger activities were recorded with dichloromethane,acetone and toluene/ethanol extracts

    Phenomenology, socio-demographic factors and outcome upon discharge of manic and mixed episodes in hospitalized adolescents

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    Background: The existence of bipolar disorder type I (BD-I) during adolescence is now clearly established whereas there are still some controversies on BD-II and BD-NOS diagnosis, mainly in Europe (O'Dowd in Br Med J 29, 2006). Little is known on the phenomenology and potential short-term prognosis factors of bipolar episodes in this age population. In particular, very few studies examine this issue on inpatients in the European context of free access to care. Objective: To describe the phenomenology of acute manic and mixed episodes in hospitalized adolescents and to analyse potential predictive factors associated with clinical improvement at discharge and length of hospitalization. Methods: A total of 80 subjects, aged 12–20 years, consecutively hospitalized for a manic or mixed episode. Socio-demographic and clinical data were extracted by reviewing patients' charts. We used a multivariate analysis to evaluate short-term outcome predictors. Results: The sample was characterized by severe impairment, high rates of psychotic features (N = 50, 62.5%), a long duration of stay (mean 80.4 days), and an overall good improvement (86% very much or much improved). Thirty-three (41.3 %) patients had a history of depressive episodes, 13 (16.3%) had manic or brief psychotic episodes but only 3 (3.7%) had a history of attention deficit/ hyperactivity disorders. More manic episodes than mixed episodes were identified in subjects with mental retardation (MR) and in subjects from migrant and/or low socio-economic families. Overall severity and female gender predicted better improvement in GAF scores. Poor insight and the existence of psychotic features predicted longer duration of stay. Conclusion: These results suggest that severe manic and mixed episodes in adolescents with BD-I need prolonged inpatient care to improve and that socio-cultural factors and MR should be examined more closely in youth with BD

    Anti-fungal and anti-termite activity of extractives compounds from thermally modified ash woods

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    Thermal modification of wood is a promising alternative to chemical and biocidal modification processes, increasing the biological durability and dimensional stability of wood. However, the wood-decay resistance properties of heat-treated wood are still not well known. The main objective of this study was to determine the biological resistance of heat-treated ash wood, and assess the antifungal and anti-termite activity of extractive compounds from heat-treated ash woods, depending on the intensity of the modification process (2 hours at 170, 200, 215, 228 (°C) - steam pressure). Untreated and heat-treated wood samples were extracted with water or acetone. The extracts were then used to determine inhibition effectiveness against white-rot (Trametes versicolor) and brown-rot (Rhodonia placenta) fungi. Whatman papers impregnated with extractives were used to evaluate the inhibition of termite feeding. Lastly, the extractives were analyzed by Gas Chromatography - Mass Spectrometry (GC-MS) and compared for their level of anti‑termite and antifungal activity. The results showed that the degree of antifungal activity of these extracts depended on the solvent used during the extraction process and varied depending on heat treatment intensity. The extracts were more effective against brown-rot than white-rot fungi. However, the anti-termite activity of heat-treated ash wood extracts was not really significant. A GC-MS analysis showed that the main share of the extractives in untreated wood was removed. In addition, new chemical elements were generated by the thermal degradation of wood polymers (lignin and hemicelluloses), including aliphatic acids, monosaccharides and other products resulting from their dehydration reaction. The most abundant element was syringaldehyde, from lignin derived compounds, which might explain the antifungal activities of thermally treated ash wood extracts

    Improvement of the durability of heat-treated wood against termites

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    Thermal modification is an attractive alternative to improve the decay durability and dimensional stability of wood. However, thermally modified wood is generally not resistant to termite attacks, limiting the field of application of such materials. One way to overcome this drawback is to combine thermal modification treatment with an additional treatment. One such treatment is the impregnation of a boron derivative associated with appropriate vinylic monomers, which takes advantage of the thermal treatment to polymerise these monomers for boron fixation. Using this strategy, we recently showed that an impregnation of borax (2 or 4% boric acid equivalent) dissolved in a 10% aqueous solution of polyglycerolmethacrylate followed by thermal treatment under nitrogen at 220°C protects wood from both termite and decay degradations, even after leaching. Additionally, wood samples treated with a 10% polyglycerolmethacrylate aqueous solution and subjected to thermal treatment at 220°C presented improved resistance to termites while avoiding boron utilization. Based on these results, we investigate the effect of impregnation with two types of vinylic monomers, which are already used in the presence of boron, followed by thermal treatments at different temperatures. We evaluate termite and decay durability of wood to evaluate if thermal modification associated with light chemical modification could be a solution for utilization of thermally modified materials in termite-infested areas

    Diagnostic performance of the WHO definition of probable dengue within the first 5 days of symptoms on Reunion Island.

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    The relevance of the World Health Organization (WHO) criteria for defining probable dengue had not yet been evaluated in the context of dengue endemicity on Reunion Island. The objective of this retrospective diagnostic study was to evaluate the diagnostic performance of the 2009 WHO definition of probable dengue and to propose an improvement thereof. From the medical database, we retrieved the data of subjects admitted to the emergency department of the University Hospital of Reunion Island in 2019 with suspected dengue fever (DF) within a maximum of 5 days post symptom onset, and whose diagnosis was confirmed by a Reverse Transcriptase Polymerase Chain Reaction (RT-PCR). The intrinsic characteristics of probable dengue definitions were reported in terms of sensitivity, specificity, positive and negative likelihood ratios (LR+ and LR-), using RT-PCR as the gold standard. Of the 1,181 subjects who exhibited a positive RT-PCR, 652 (55%) were classified as probable dengue. The WHO definition of probable dengue yielded a sensitivity of 64% (95%CI 60-67%), a specificity of 57% (95%CI 52-61%), a LR+ of 1.49 (95%CI 1.33-1.67), and a LR- of 0.63 (95%CI 0.56-0.72). The sensitivity and LR- for diagnosing and ruling out probable dengue could be improved by the addition of lymphopenia on admission (74% [95%CI: 71-78%] and 0.54 [95%CI: 0.46-0.63] respectively), at the cost of slight reductions of specificity and LR+ (48% [95%CI: 44-53%] and 1.42 [95%CI: 1.29-1.57], respectively). In the absence of, or when rapid diagnostic testing is unreliable, the use of the improved 2009 WHO definition of probable dengue could facilitate the identification of subjects who require further RT-PCR testing, which should encourage the development of patient management, while also optimizing the count and quarantine of cases, and guiding disease control

    Pandemic Influenza Due to pH1N1/2009 Virus: Estimation of Infection Burden in Reunion Island through a Prospective Serosurvey, Austral Winter 2009

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    International audienceBACKGROUND: To date, there is little information that reflects the true extent of spread of the pH1N1/2009v influenza pandemic at the community level as infection often results in mild or no clinical symptoms. This study aimed at assessing through a prospective study, the attack rate of pH1N1/2009 virus in Reunion Island and risk factors of infection, during the 2009 season.METHODOLOGY/PRINCIPAL FINDINGS: A serosurvey was conducted during the 2009 austral winter, in the frame of a prospective population study. Pairs of sera were collected from 1687 individuals belonging to 772 households, during and after passage of the pandemic wave. Antibodies to pH1N1/2009v were titered using the hemagglutination inhibition assay (HIA) with titers ≄ 1/40 being considered positive. Seroprevalence during the first two weeks of detection of pH1N1/2009v in Reunion Island was 29.8% in people under 20 years of age, 35.6% in adults (20-59 years) and 73.3% in the elderly (≄ 60 years) (P<0.0001). Baseline corrected cumulative incidence rates, were 42.9%, 13.9% and 0% in these age groups respectively (P<0.0001). A significant decline in antibody titers occurred soon after the passage of the epidemic wave. Seroconversion rates to pH1N1/2009 correlated negatively with age: 63.2%, 39.4% and 16.7%, in each age group respectively (P<0.0001). Seroconversion occurred in 65.2% of individuals who were seronegative at inclusion compared to 6.8% in those who were initially seropositive.CONCLUSIONS: Seroincidence of pH1N1/2009v infection was three times that estimated from clinical surveillance, indicating that almost two thirds of infections occurring at the community level have escaped medical detection. People under 20 years of age were the most affected group. Pre-epidemic titers ≄ 1/40 prevented seroconversion and are likely protective against infection. A concern was raised about the long term stability of the antibody responses
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