Deciphering the molecular adaptation of the king scallop (Pecten maximus) to heat stress using transcriptomics and proteomics

Background The capacity of marine species to survive chronic heat stress underpins their ability to survive warming oceans as a result of climate change. In this study RNA-Seq and 2-DE proteomics were employed to decipher the molecular response of the sub-tidal bivalve Pecten maximus, to elevated temperatures. Results Individuals were maintained at three different temperatures (15, 21 and 25 °C) for 56 days, representing control conditions, maximum environmental temperature and extreme warming, with individuals sampled at seven time points. The scallops thrived at 21 °C, but suffered a reduction in condition at 25 °C. RNA-Seq analyses produced 26,064 assembled contigs, of which 531 were differentially expressed, with putative annotation assigned to 177 transcripts. The proteomic approach identified 24 differentially expressed proteins, with nine identified by mass spectrometry. Network analysis of these results indicated a pivotal role for GAPDH and AP-1 signalling pathways. Data also suggested a remodelling of the cell structure, as revealed by the differential expression of genes involved in the cytoskeleton and cell membrane and a reduction in DNA repair. They also indicated the diversion of energetic metabolism towards the mobilization of lipid energy reserves to fuel the increased metabolic rate at the higher temperature. Conclusions This work provides preliminary insights into the response of P. maximus to chronic heat stress and provides a basis for future studies examining the tipping points and energetic trade-offs of scallop culture in warming oceans

Procédé de préparation d'un matériau solide de stockage de l'ozone, ledit matériau et ses utilisations

La présente invention concerne un procédé et une installation pour la préparation d’un matériau solide de stockage de l’ozone, ce procédé comprenant la mise en contact de cyclodextrines et/ou de dérivés de cyclodextrines se présentant sous forme solide avec un gaz comprenant de l’ozone moyennant quoi un matériau solide de stockage de l’ozone est obtenu. La présente invention concerne également le matériau ainsi préparé et ses utilisations

Hydrogen sulphide quantification by SIFT/MS: highlighting the influence of gas moisture

The quantification of hydrogen sulphide (H2S) by Selected Ion Flow Tube coupled with Mass Spectrometry (SIFT/MS) was investigated for application in industrial emission context, usually faced with concentrations of water vapour higher than the saturation at room condition. H2S concentrations measured by SIFT/MS (using nitrogen as carrier gas and flow tube temperature at 119°C) were affected by water content, reducing the sensibility for H2S measurements. Accurate concentrations were obtained when the influence of water was considered on SIFT/MS analysis, requiring although the information about water content in the sample. In addition, the association of low concentration of H2S (around 50 ppbv) and high humidity level (4.0 %vol of water) was highlighted as a critical point for measuring H2S by SIFT/MS, due to the sensibility reduction as function of water content and the measurement uncertainty enhancement at low signal intensity

Aldehydes gas ozonation monitoring: Interest of SIFT/MS versus GC/FID

Two analytical techniques e online Gas Chromatography coupled with Flame Ionization Detector (often used method for VOCs monitoring) versus Selected Ion Flow Tube coupled with Mass Spectrometry (a more recent technique based on direct mass spectrometry) e were compared in association to an ozonebased gas treatment. Selecting aldehydes as the representative VOCs, their concentrations were monitored during ozonation experiments by both techniques in parallel. Contradictory results were obtained in the presence of ozone. Aldehydes were up to 90% removed due to a reaction with ozone according to GC/FID analysis, whereas with SIFT/MS, aldehydes concentration remained at the same level during the experiments regardless of the ozone presence. In addition, it was demonstrated that the apparent aldehydes removal was affected by GC injector temperature, varying from 90% (when it was at 250 °C) to 60% (at 100 °C). Meanwhile, even when the ozonation reactor was heated to 100 °C, no aldehydes conversion was evidenced by SIFT/MS, suggesting that the GC injector temperature was not the only interference-causing parameter. The ozone-aldehyde reaction is probably catalyzed by some material of GC injector and/or column. An ozone-GC interference was therefore confirmed, making unsuitable the use of GC/FID with silicone stationary phase to monitor aldehydes in presence of high concentrations of ozone (at least 50 ppmv). On the other hand, SIFT/MS was validated as a reliable technique, which can be employed in order to measure VOCs concentrations in ozonation processes

A catalyst-free process for gas ozonation of reduced sulfur compounds

The feasibility of homogenous gas ozonation process was investigated in order to reduce the negative environmental impact caused by reduced sulfur compounds (RSCs). Emitted from a variety of industrial plants, this class of compounds are known by their odor properties. Selecting hydrogen sulfide (H2S), methyl ethyl sulfide (MES) and dimethyl disulfide (DMDS) as representative odorous RSCs, the influence of four gas ozonation process parameters (ozone concentration, humidity level, reactor temperature and residence time) on their removal efficiencies was evaluated using a Doehlert experimental design in an experimental domain compatible with industrial constraints. Ozone concentration was the only process parameter that has resulted in a positive – but limited – effect on the removal efficiency of the mix of RSCs. However, even if ozone was present in large excess (20 times the RSCs concentration), MES and DMDS were slightly consumed (around 30%). Only H2S has shown interesting removal efficiencies (up to 80%). In addition to the measurement of reagent concentrations, Selected Ion Flow Tube coupled with Mass Spectrometry (SIFT/MS) was applied to identify and quantify the potential products of RSCs-ozone reaction. Methyl ethyl sulfone (MESO2) was found to be the primary product of MES, whereas methyl methanethiosulfinate (DMSOS) and sulfur dioxide (SO2) for DMDS, suggesting that the organic monosulfide and disulfides would not follow the same reaction mechanism with ozone in gas phase. In addition, SO2 and H2O may not be the only end products for H2S ozonation, since additional peaks were detected in SIFT/MS spectr

Space-Time Plasma-Steering Source: Control of Microwave Plasmas in Overmoded Cavities

Recently, space-time plasma-steering source has been proposed as an innovative microwave plasma source to meet the challenge of controlling plasmas in overmoded cavities. This concept has been successfully demonstrated experimentally, allowing the space-time control of nanosecond microwave plasmas on initiators. This paper gives insights into the path that shall be taken to reach full space-time control of plasmas in overmoded cavities. To that end, a key criterion, namely the “plasma-steering criterion,” is introduced and verified with a numerical model. This criterion must be respected for an accurate space-time control of plasmas in overmoded cavities. The usefulness of the plasma density (depending on its value with respect to the critical plasma density) on the plasma-control capabilities is also highlighted

Ozone Quantification by Selected Ion Flow Tube Mass Spectrometry: Influence of Humidity and Manufacturing Gas of Ozone Generator

The quantification of ozone by SIFT-MS was investigated in conditions suitable with an industrial emission context (high ozone demand, dry air/oxygen as the manufacturing gas of the ozone generator, and high humidity levels beyond saturation at room conditions). Ozone reacts with four negative precursor ions available in the SIFT-MS device (NO2–, O2–, HO–, and O–), each precursor ion having its specific domain of linearity. For a high ozone concentration range, only NO2– and O2– have resulted in a linear behavior (between 1 and 100 ppmv of O3 for NO2–, between 1 and 50 ppmv of O3 for O2–). No water interference was identified during ozone measurements by SIFT-MS using NO2– and O2– precursor ions, even with extreme humidity levels. The presence of nitrogen oxide contaminants (due to the use of dry air as the manufacturing gas of the ozone generator) affected the ozone quantification by SIFT-MS. It is critical for NO2– precursor ions, whose rate constant varied as a function of NO2 concentrations. With O2– precursor ion, ozone was successfully measured in the presence of nitrogen oxides; however, the secondary chemistry must be taken into account

Impact of Emergent Cervical Carotid Stenting in Tandem Occlusion Strokes Treated by Thrombectomy: A Review of the TITAN Collaboration

Introduction: Endovascular therapy has been shown to be an effective and safe treatment for tandem occlusion. The endovascular therapeutic strategies for tandem occlusions strokes have not been adequately evaluated and the best approach is still controversial. The TITAN (Thrombectomy in TANdem occlusions) registry was a result of a collaborative effort to identify the best therapeutic approach for acute ischemic stroke due to tandem lesion. In this review, we aim to summarize the main findings of the TITAN study and discuss the challenges of treatment for tandem occlusion in the era of endovascular thrombectomy.Methods: A review of the data from the multicenter international observational and non-randomized TITAN registry was performed. The TITAN registry included acute ischemic stroke patients with tandem lesions (proximal intracranial occlusion and cervical carotid artery occlusion or stenosis>90%) who were treated with thrombectomy with or without carotid artery stenting.Results: Prior intravenous thrombolysis and emergent cervical carotid stenting were associated with higher reperfusion (mTICI 2b-3 and mTICI 3) rates at the end of the intervention. Poor outcome did not occur more frequently after stenting than after conservative treatment of the cervical carotid lesion. Emergent carotid stenting with antithrombotic agents and intracranial thrombectomy yielded higher reperfusion rate and good outcome (90 day mRS 0–2) compared to other strategies (carotid artery stenting and thrombectomy without antithrombotic, angioplasty and thrombectomy, or thrombectomy alone). Pretreatment intravenous thrombolysis was not associated with increased risk of hemorrhagic complications. Likewise, periprocedural unfractionated heparin did not modify the efficacy and safety results. Etiology of carotid artery lesion (atherosclerosis vs. dissection) did not emerge as predictor of outcome or recanalization.Conclusion: Emergent stenting of the cervical carotid lesion with antithrombotic agents in conjunction to thrombectomy appears to be the best treatment strategy for acute ischemic strokes with tandem lesions. These findings will be further investigated in the ongoing randomized controlled TITAN trial

Sulphadoxine/pyrimethamine versus amodiaquine for treating uncomplicated childhood malaria in Gabon: A randomized trial to guide national policy

<p>Abstract</p> <p>Background</p> <p>In Gabon, following the adoption of amodiaquine/artesunate combination (AQ/AS) as first-line treatment of malaria and of sulphadoxine/pyrimethamine (SP) for preventive intermittent treatment of pregnant women, a clinical trial of SP versus AQ was conducted in a sub-urban area. This is the first study carried out in Gabon following the WHO guidelines.</p> <p>Methods</p> <p>A random comparison of the efficacy of AQ (10 mg/kg/day × 3 d) and a single dose of SP (25 mg/kg of sulphadoxine/1.25 mg/kg of pyrimethamine) was performed in children under five years of age, with uncomplicated falciparum malaria, using the 28-day WHO therapeutic efficacy test. In addition, molecular genotyping was performed to distinguish recrudescence from reinfection and to determine the frequency of the <it>dhps </it>K540E mutation, as a molecular marker to predict SP-treatment failure.</p> <p>Results</p> <p>The day-28 PCR-adjusted treatment failures for SP and AQ were 11.6% (8/69; 95% IC: 5.5–22.1) and 28.2% (20/71; 95% CI: 17.7–38.7), respectively This indicated that SP was significantly superior to AQ (<it>P </it>= 0.019) in the treatment of uncomplicated childhood malaria and for preventing recurrent infections. Both treatments were safe and well-tolerated, with no serious adverse reactions recorded. The <it>dhps </it>K540E mutation was not found among the 76 parasite isolates tested.</p> <p>Conclusion</p> <p>The level of AQ-resistance observed in the present study may compromise efficacy and duration of use of the AQ/AS combination, the new first-line malaria treatment. Gabonese policy-makers need to plan country-wide and close surveillance of AQ/AS efficacy to determine whether, and for how long, these new recommendations for the treatment of uncomplicated malaria remain valid.</p