57 research outputs found

    Crop Level and Harvest Date Impact on Four Ontario Wine Grape Cultivars. II. Wine Aroma Compounds and Sensory Analysis

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    Pinot gris, Riesling, Cabernet franc and Cabernet Sauvignon from a vineyard in Virgil, Ontario, Canada were subjected by cluster thinning to two crop-level treatments (full crop, half crop), combined with threeharvest dates (commercial harvest (T0), three weeks after T0 (T1), six weeks after T0 (T2)) in a randomised experiment in 2011 and 2012, with wines produced from all treatment replicates. We hypothesised that afull crop with substantially delayed harvest date might have a greater impact on wine aroma than reducing crop level. Wine aroma volatile analysis was carried out by GC-MS, with quantification by calibration withanalytical standards prepared in model wine. Delayed harvest overcame the effects of crop reduction for almost all volatiles. Pinot gris and Riesling displayed increases in varietal aromas in the T1 and T2 wines, e.g. monoterpenes and norisoprenoids, and in esters, aldehydes and alcohols. Reduced concentrations of volatile acids and green odour compounds (e.g. 1-hexanol) with delayed harvest were also evident.  Increases in ethanol were related to increased berry sugars, but higher alcohols did not necessarily increase with harvest date. Crop level had little impact on the sensory properties of these cultivars in both seasons.  However, delayed harvest resulted in substantial sensorial changes. Due to these chemical and sensorial effects, delayed harvest is recommended, rather than crop-level reduction, to enhance wine quality in these cultivars. Extended harvest, e.g. T2 treatments, was associated with the production of benzaldehyde, diethyl acetal, and higher concentrations of higher alcohols, e.g. isoamyl alcohol and nonanol, which could be linked to pre-harvest desiccation

    Population pharmacokinetics of colistin and the relation to survival in critically ill patients infected with colistin susceptible and carbapenem-resistant bacteria

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    Objectives: The aim was to analyse the population pharmacokinetics of colistin and to explore the relationship between colistin exposure and time to death. Methods: Patients included in the AIDA randomized controlled trial were treated with colistin for severe infections caused by carbapenem-resistant Gram-negative bacteria. All subjects received a 9 million units (MU) loading dose, followed by a 4.5 MU twice daily maintenance dose, with dose reduction if creatinine clearance (CrCL) 2 mg/L in 94% (195/208) and 44% (38/87) of patients with CrCL ≤120 mL/min, and >120 mL/min, respectively. Colistin methanesulfonate sodium (CMS) and colistin clearances were strongly dependent on CrCL. High colistin exposure to MIC ratio was associated with increased hazard of death in the multivariate analysis (adjusted hazard ratio (95% CI): 1.07 (1.03–1.12)). Other significant predictors included SOFA score at baseline (HR 1.24 (1.19–1.30) per score increase), age and Acinetobacter or Pseudomonas as index pathogen. Discussion: The population pharmacokinetic model predicted that >90% of the patients had colistin concentrations

    Detrimental effect of apoptosis of lymphocytes at an early time point of experimental abdominal sepsis

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    <p>Abstract</p> <p>Background</p> <p>Apoptosis of lymphocytes is considered a late sequelum in the sepsis cascade. The role of apoptosis of lymphocytes as a driver of final outcome was investigated.</p> <p>Methods</p> <p>Abdominal sepsis was induced after cecal ligation and puncture (CLP) in 31 rabbits. Blood was sampled at serial time intervals and peripheral blood mononuclear cells (PBMCs) were isolated. Apoptosis of lymphocytes and monocytes was measured through flow cytometric analysis. PBMCs were stimulated with LPS and Pam3Cys for the release of tumor necrosis factor-alpha (TNFα). Tissue bacterial growth was quantitatively measured. In a second set of experiments, CLP was performed in another 40 rabbits; 20 received single intravenous infusions of ciprofloxacin and of metronidazole 4 hours after surgery.</p> <p>Results</p> <p>Animals were divided into two groups based on the percentage of lymphocyte apoptosis at 4 hours after surgery; less than or equal to 32% and more than 32%. Survival of the former was shorter than the latter (p: 0.017). Tissue growth was similar between groups. Apoptosis of lymphocytes and of monocytes was lower in the former group over follow-up. Release of ΤNFα did not differ. The above findings on survival were repeated in the second set of experiments. Administration of antimicrobials prolonged survival of the former group (p: 0.039) but not of the latter group (pNS).</p> <p>Conclusions</p> <p>Lymphocyte apoptosis at an early time point of experimental peritonitis is a major driver for death. A lower percentage of apoptosis leads earlier to death. Antimicrobials were beneficial even at that disease state.</p

    Synthesis of magnetocaloric Mn5-xFexSi3 (2.5≤x≤4.0) compounds and the influence of various sintering atmospheres on the magnetic and electrical properties

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    Polycrystalline powders of Mn5-xFexSi3 (x ​= ​2.5, 3.0, 3.5, 4.0) compounds (Mn5Si3-type, space group P63/mcm, No. 193) were prepared by solid state reaction of pure Mn, Fe and Si powders under High Vacuum (HV) conditions at T ​= ​1000 ​°C. Samples were sintered at T ​= ​1100 ​°C under HV as well as under Ar-4%H2 conditions. X-ray Diffraction (XRD) analysis revealed that the compounds crystallize with hexagonal symmetry in accordance with previous reports. The χac susceptibility measurements for the samples sintered under HV conditions show systematic strengthening of the ferromagnetic (FM) state upon increasing x. The electrical resistivity, ρ, remains metallic for all x, with a very weak temperature dependence at T ​&amp;gt; ​300 ​K. At T ​&amp;lt; ​300 ​K, ρ(T) shows a linear temperature dependence with a change of slope observed upon approaching the corresponding magnetic ordering temperature. For the samples sintered under flowing Ar-4%H2 atmosphere, the electrical properties are similar to those of the samples sintered under HV, while a strong enhancement of χac was observed. © 2021 Elsevier Inc

    A prognostic score for the resolution of bacteremia by Gram-negative bacteria resistant to carbapenems

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    The management of bacteremia by carbapenem-resistant Gram-negative bacteria (CRGNB) necessitates a surrogate marker for response to treatment. We developed a prognostic score of bacteremia resolution using a test and a validation cohort. In the test cohort, five protein biomarkers were measured in serial daily serum samples from 39 patients with ventilator-associated pneumonia (VAP) and CRGNB bacteremia. Receiver operator characteristic curves were designed to identify cut-off of over-time changes that were associated with more than 80% specificity for resolution of bacteremia. The developed score was validated in a cohort of 24 patients mostly with primary bacteremia by carbapenem-resistant enterobacteria (CRE). Among the five tested biomarkers, only procalcitonin (PCT) was associated with resolution of bacteremia. More precisely, resolved bacteremia was considered if at least one of three situations occurred: (a) PCT on day 2 was decreased more than 30% and PCT on day 4 was below 0.5&nbsp;ng/ml; (b) PCT on day 4 was decreased more than 40% and PCT on day 4 was below 0.5&nbsp;ng/ml; and (c) PCT on day 2 was decreased more than 30% and PCT on day 4 was decreased more than 40%. Sensitivity, specificity, and positive and negative predictive values of the score were 66.7%, 83.3%, 90.0%, and 52.6% respectively. This score was fully validated (p values of comparison between the cohorts 0.623). The developed score is highly predictive of resolution of bacteremia by CRGNB. A prospective clinical study is mandatory to validate the results

    PM2.5-bound organosulfates in two Eastern Mediterranean cities: The dominance of isoprene organosulfates

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    PM2.5 samples were collected during 2017–2018 at two Eastern Mediterranean urban sites in Greece, Athens and Patra, in order to study the abundances, the seasonal trends, the sources and the possible impact of gas phase pollutants on organosulfate formation. Each of the studied groups, except that of aromatic organosulfates, presented higher concentrations in Patra compared to those measured in Athens, from 1.1 (nitro-oxy organosulfates) to 3.6 times (isoprene organosulfates). At both sites, isoprene organosulfates was the dominant group which accounted on average for more than 50% of the total measured organosulfates, with the contribution being more than 80% during summer. Strong seasonality was observed at both sites, regarding the isoprene organosulfates, with an almost 21-fold increase from winter to summer. The same pattern, but to a lesser extent, was also observed for monoterpenes organosulfates at both sites. Alkyl organosulfates followed an identical seasonal trend with the highest mean concentrations observed during spring followed by autumn. The seasonality of anthropogenic organosulfates, multisource organosulfates and nitro-oxy organosulfates differed among the two sites or presented a more compound-specific variation. The isoprene-epoxydiol pathway appeared to be the dominant pathway of isoprene transformation, with the compounds iOS211, iOS213 and iOS215 being the major isoprene organosulfate compounds at both sites. Organosulfate contribution to the concentration of particulate matter presented common variation at both sites, ranging from 0.20 ± 0.14% (winter) to 2.5 ± 1.2% (summer) and from 0.21 ± 0.13% (winter) to 5.0 ± 2.5% (summer) for Athens and Patra, respectively. The increased NOx levels in Athens, appeared to affect isoprene organosulfate formation as well as the formation of monoterpene and decalin nitro-oxy organosulfates. Principal component analysis followed by multiple linear regression analysis highlighted the dominance of isoprene organosulfates. In Athens, the possible impact of transportation emissions on the formation of monoterpene nitro-oxy organosulfates is indicated while the correlation of naphthalene organosulfates with low molecular weight polycyclic aromatic hydrocarbons suggests that vehicle emissions may be a significant source. In Patra, the possible contribution of sea on methyl sulfate levels is denoted. © 2022 Elsevier Lt

    A prognostic score for the resolution of bacteremia by Gram-negative bacteria resistant to carbapenems

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    The management of bacteremia by carbapenem-resistant Gram-negative bacteria (CRGNB) necessitates a surrogate marker for response to treatment. We developed a prognostic score of bacteremia resolution using a test and a validation cohort. In the test cohort, five protein biomarkers were measured in serial daily serum samples from 39 patients with ventilator-associated pneumonia (VAP) and CRGNB bacteremia. Receiver operator characteristic curves were designed to identify cut-off of over-time changes that were associated with more than 80% specificity for resolution of bacteremia. The developed score was validated in a cohort of 24 patients mostly with primary bacteremia by carbapenem-resistant enterobacteria (CRE). Among the five tested biomarkers, only procalcitonin (PCT) was associated with resolution of bacteremia. More precisely, resolved bacteremia was considered if at least one of three situations occurred: (a) PCT on day 2 was decreased more than 30% and PCT on day 4 was below 0.5 ng/ml; (b) PCT on day 4 was decreased more than 40% and PCT on day 4 was below 0.5 ng/ml; and (c) PCT on day 2 was decreased more than 30% and PCT on day 4 was decreased more than 40%. Sensitivity, specificity, and positive and negative predictive values of the score were 66.7%, 83.3%, 90.0%, and 52.6% respectively. This score was fully validated (p values of comparison between the cohorts 0.623). The developed score is highly predictive of resolution of bacteremia by CRGNB. A prospective clinical study is mandatory to validate the results. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature
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