Epidemiology of intra-abdominal infection and sepsis in critically ill patients: “AbSeS”, a multinational observational cohort study and ESICM Trials Group Project

Purpose: To describe the epidemiology of intra-abdominal infection in an international cohort of ICU patients according to a new system that classifies cases according to setting of infection acquisition (community-acquired, early onset hospital-acquired, and late-onset hospital-acquired), anatomical disruption (absent or present with localized or diffuse peritonitis), and severity of disease expression (infection, sepsis, and septic shock). Methods: We performed a multicenter (n = 309), observational, epidemiological study including adult ICU patients diagnosed with intra-abdominal infection. Risk factors for mortality were assessed by logistic regression analysis. Results: The cohort included 2621 patients. Setting of infection acquisition was community-acquired in 31.6%, early onset hospital-acquired in 25%, and late-onset hospital-acquired in 43.4% of patients. Overall prevalence of antimicrobial resistance was 26.3% and difficult-to-treat resistant Gram-negative bacteria 4.3%, with great variation according to geographic region. No difference in prevalence of antimicrobial resistance was observed according to setting of infection acquisition. Overall mortality was 29.1%. Independent risk factors for mortality included late-onset hospital-acquired infection, diffuse peritonitis, sepsis, septic shock, older age, malnutrition, liver failure, congestive heart failure, antimicrobial resistance (either methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, extended-spectrum beta-lactamase-producing Gram-negative bacteria, or carbapenem-resistant Gram-negative bacteria) and source control failure evidenced by either the need for surgical revision or persistent inflammation. Conclusion: This multinational, heterogeneous cohort of ICU patients with intra-abdominal infection revealed that setting of infection acquisition, anatomical disruption, and severity of disease expression are disease-specific phenotypic characteristics associated with outcome, irrespective of the type of infection. Antimicrobial resistance is equally common in community-acquired as in hospital-acquired infection

Complex electrical conductivity measurements of a KTB amphibolite sample at elevated temperatures

In the present work, complex electrical conductivity measurements in the frequency range of 10 mHz–1 MHz and at elevated temperatures (423 K–1373 K) were carried out in amphibolite sample, originating from the KTB drilling. Impedance Cole–Cole plots were used to discriminate the contributions of grain interior, grain boundaries and electrode polarization effects to the measured conductivity spectra. At frequencies above 10 Hz where the electrode effects are negligible, ac-conductivity exhibits frequency dispersion according to a two-term power law behaviour, in most cases of the isothermal spectra. A conductivity relaxation step is observed during heating of the sample up to 773 K, which is attributed to strongly bound water, either in the form of hydroxyls in the crystal lattice of grains, or in the form of molecules trapped between the grain boundaries. The hysteresis plot of dc-conductivity shows an anomalous behaviour at around 1000 K during the heating procedure, due to the dehydroxylation of the sample. The electric modulus M* representation provides additional information over the low temperature range and the conductivity relaxation times were estimated for a limited temperature range. Thermal activation energies of Arrhenius type vary from 0.58 eV up to 1.50 eV, and they are ascribed to proton conduction at low temperature and hopping conduction of small polarons at higher temperatures

Discovery of two novel laccase-like multicopper oxidases from Pleurotus citrinopileatus and their application in phenolic oligomer synthesis

Background: Laccases and laccase-like multicopper oxidases (LMCOs) oxidize a vast array of phenolic compounds and amines, releasing water as a byproduct. Their low substrate specificity is responsible for their tremendous biotechnological interest, since they have been used for numerous applications. However, the laccases characterized so far correspond to only a small fraction of the laccase genes identified in fungal genomes. Therefore, the knowledge regarding the biochemistry and physiological role of minor laccase-like isoforms is still limited. Results: In the present work, we describe the isolation, purification and characterization of two novel LMCOs, PcLac1 and PcLac2, from Pleurotus citrinopileatus. Both LMCOs were purified with ion-exchange chromatographic methods. PcLac2 was found to oxidize a broader substrate range than PcLac1, but both LMCOs showed similar formal potentials, lower than those reported previously for laccases from white-rot fungi. Proteomic analysis of both proteins revealed their similarity with other well-characterized laccases from Pleurotus strains. Both LMCOs were applied to the oxidation of ferulic and sinapic acid, yielding oligomers with possible antioxidant activity. Conclusions: Overall, the findings of the present work can offer new insights regarding the biochemistry and variability of low-redox potential laccases of fungal origin. Low-redox potential biocatalysts could offer higher substrate selectivity than their high-redox counterparts, and thus, they could be of applied value in the field of biocatalysis

Discovery of two novel laccase-like multicopper oxidases from Pleurotus citrinopileatus and their application in phenolic oligomer synthesis

Background Laccases and laccase-like multicopper oxidases (LMCOs) oxidize a vast array of phenolic compounds and amines, releasing water as a byproduct. Their low substrate specificity is responsible for their tremendous biotechnological interest, since they have been used for numerous applications. However, the laccases characterized so far correspond to only a small fraction of the laccase genes identified in fungal genomes. Therefore, the knowledge regarding the biochemistry and physiological role of minor laccase-like isoforms is still limited. Results In the present work, we describe the isolation, purification and characterization of two novel LMCOs, PcLac1 and PcLac2, from Pleurotus citrinopileatus. Both LMCOs were purified with ion-exchange chromatographic methods. PcLac2 was found to oxidize a broader substrate range than PcLac1, but both LMCOs showed similar formal potentials, lower than those reported previously for laccases from white-rot fungi. Proteomic analysis of both proteins revealed their similarity with other well-characterized laccases from Pleurotus strains. Both LMCOs were applied to the oxidation of ferulic and sinapic acid, yielding oligomers with possible antioxidant activity. Conclusions Overall, the findings of the present work can offer new insights regarding the biochemistry and variability of low-redox potential laccases of fungal origin. Low-redox potential biocatalysts could offer higher substrate selectivity than their high-redox counterparts, and thus, they could be of applied value in the field of biocatalysis

Physico-chemical characteristics of particulate matter in the Eastern Mediterranean

Summarization: Particulate matter (PM10, PM2.5) measurements were performed during the period 2003–2009 at the Akrotiri monitoring station (suburban/rural) on the island of Crete, Greece. Concurrent measurements of PM10 size distribution/chemical composition were also performed at selected time intervals to determine the PM sources in the region and the factors controlling their levels. Using a beta radiation attenuation monitor, the mean PM10 concentration during the measuring period (15.04.2003–31.12.2009) was equal to 36.1 ± 9.5 μg/m3, whereas the PM2.5 concentration was equal to 23.6 ± 5.8 μg/m3. Back trajectories showed that the dominant air mass origin was from North and Northwest Europe but the intrusion of southern air masses lead to elevated PM concentrations due to Saharan dust events. The 24-h EU limit value of 50 μg/m3 (PM10) was exceeded approximately 13.5% during the measured period. Furthermore, the PM10 mass size distribution of metals, ions and organic carbon/elemental carbon (OC/EC) was characterized using a 9-stage Andersen non-viable impactor and a gravimetric sequential PM10 sampler during two selected periods. The mean PM10 concentration during the first sampling period was equal to 28.3 ± 12.4 μg/m3 (10.08.2007–28.08.2007), whereas during the second sampling period (09.07.2008–19.07.2008) was 41.6 ± 14.0 μg/m3. The measurements showed a bimodal size distribution for the aerosol mass concentration. PM2.1 accounted for 41.0% and 37.2% for PM10 during the two periods respectively. Over the measurement campaigns ions dominated the PM10 mass (50–80%) with the organic mass and metals comprising the major part of the rest. The OC concentration was equal to 2.3 ± 1.2 μg/m3, whereas the EC concentration was equal to 0.8 ± 0.2 μg/m3. Finally, black carbon concentrations were measured in August 2007 with an aethalometer. The mean daily value of black carbon was 0.69 ± 0.22 μg/m3. The measurements showed that the PM values measured at the station correspond to a background/rural station in the region and are in agreement with other measurements in the Eastern Mediterranean region.Παρουσιάστηκε στο: Atmospheric Researc

Particulate matter measurements at Akrotiri research station, Crete, Greece

Summarization: Particulate matter measurements were performed at the Akrotiri research station on the island of Crete (Greece) using an 8-stages Andersen non-viable impactor. The main purpose of this work was to measure the ambient levels of PM10 particulate matter and their concentrations of metals and ions in 9 different size bins. The mean PM10 concentration during the first measurement period was equal to 28.3 ± 12.4 μg/m3 , whereas during the period of July 2008 was 41.6 ± 14.0 μg/m3 . Moreover, mean concentrations of PM3.3 particulate matter were measured on the average equal to a 49 % and 45 % of PM10, respectively. The measurements showed high concentration of nanoparticles (with aerodynamic diameter less than 0.9 μm), whereas the mass concentration peak was located at an aerodynamic diameter of 4 - 5 μm. Back trajectory analysis showed that during the measurement period winds were mainly originated from North-West direction.Παρουσιάστηκε στο: 11th International Conference on Environmental Science and Technolog