GaMin’11 – an International Inter-laboratory Comparison for Geochemical CO2 - Saline Fluid - Mineral Interaction Experiments

Due to the strong interest in geochemical CO2-fluid-rock interaction in the context of geological storage of CO2 a growing number of research groups have used a variety of different experimental ways to identify important geochemical dissolution or precipitation reactions and – if possible – quantify the rates and extent of mineral or rock alteration. In this inter-laboratory comparison the gas-fluid-mineral reactions of three samples of rock-forming minerals have been investigated by 11 experimental labs. The reported results point to robust identification of the major processes in the experiments by most groups. The dissolution rates derived from the changes in composition of the aqueous phase are consistent overall, but the variation could be reduced by using similar corrections for changing parameters in the reaction cells over time. The comparison of experimental setups and procedures as well as of data corrections identified potential improvements for future gas-fluid-rock studies

Colloid/nanoparticle formation and mobility in the context of deep geological nuclear waste disposal (Project KOLLORADO-2) ; final report (KIT Scientific Reports ; 7645)

To assess the relevance of colloidal influences on radionuclide transport for the long-term safety of a radioactive waste repository, the KOLLORADO-2 project integrates the results of geochemical and hydrogeological studies. The results may serve as a basis for an appraisal of the implications of colloid presence in the vicinity of radioactive waste repositories in different deep geological host-rock formations

Natural hydrogen migration along thrust faults in foothill basins: The North Pyrenean Frontal Thrust case study

International audienceThe existence of geological fluids rich in natural hydrogen (H2) raises the question about the energy potential of this carbon-free resource. However, to date there is no exploration strategy based on robust methodologies and pathfinders. Therefore, it is important to develop an exploration guide that is not only focused on surface gas monitoring, but that also considers the local deep geological setting integrating the entire hydrogen system from source to trap or leakage into the atmosphere.The northwestern Pyrenees, and particularly the Mauléon Basin, represent a promising geological environment for natural H2 exploration for at least four reasons. First, an ultramafic mantle body is emplaced at shallow depth below the basin under pressure-temperature conditions favorable to serpentinization. Second, major faults such as the North Pyrenean Frontal Thrust constitute large-scale fluid flow convergence and drainage. Third, hydraulic gradients imposed by sharp reliefs and combined with temperature and pressure gradients trigger fluid migration. Fourth, impermeable sedimentary formations or caprocks such as evaporites or claystones overly porous reservoir rocks that could constitute traps for accumulating H2.To investigate H2 migration at the fault scale, we present new geochemical and geophysical data recorded along the North Pyrenean Frontal Thrust. Based on both soil gas and electromagnetic transects, we reveal the presence of a gas-draining fault. Soil gas concentration (H2, CO2, CH4 and 222Rn) recorded at 1 m depth increases when approaching the North Pyrenean Frontal Thrust. The maximum H2, CO2 and 222Rn concentrations recorded in the fault zone are 822 ppmv, 10.3 vol% and 57 kBq.m−3, respectively - whereas their local background concentrations are by 1–2 orders of magnitude lower: 10 ppmv, 0.2 vol% and 0.3 kBq.m−3 respectively. Our geochemical and geophysical data support the concept of a deep-fluid migration along the detected fault plane. In addition, the study of historical well data combined with the most recent geological and geophysical surveys carried out in the region, highlights zones where H2 could accumulate at depth. The Triassic salt formations, located at 2800 to 4000 m deep beneath the Mauléon Basin, represent the most promising trap for H2 in the northwestern Pyrenees

Fabrication, structural and electrical properties of compressively strained Ge-on-insulator substrates.

International audienc

ICU survival and need of renal replacement therapy with respect to AKI duration in critically ill patients

Abstract Background Transient and persistent acute kidney injury (AKI) could share similar physiopathological mechanisms. The objective of our study was to assess prognostic impact of AKI duration on ICU mortality. Design Retrospective analysis of a prospective database via cause-specific model, with 28-day ICU mortality as primary end point, considering discharge alive as a competing event and taking into account time-dependent nature of renal recovery. Renal recovery was defined as a decrease of at least one KDIGO class compared to the previous day. Setting 23 French ICUs. Patients Patients of a French multicentric observational cohort were included if they suffered from AKI at ICU admission between 1996 and 2015. Intervention None. Results A total of 5242 patients were included. Initial severity according to KDIGO creatinine definition was AKI stage 1 for 2458 patients (46.89%), AKI stage 2 for 1181 (22.53%) and AKI stage 3 for 1603 (30.58%). Crude 28-day ICU mortality according to AKI severity was 22.74% (n = 559), 27.69% (n = 327) and 26.26% (n = 421), respectively. Renal recovery was experienced by 3085 patients (58.85%), and its rate was significantly different between AKI severity stages (P < 0.01). Twenty-eight-day ICU mortality was independently lower in patients experiencing renal recovery [CSHR 0.54 (95% CI 0.46–0.63), P < 0.01]. Lastly, RRT requirement was strongly associated with persistent AKI whichever threshold was chosen between day 2 and 7 to delineate transient from persistent AKI. Conclusions Short-term renal recovery, according to several definitions, was independently associated with higher mortality and RRT requirement. Moreover, distinction between transient and persistent AKI is consequently a clinically relevant surrogate outcome variable for diagnostic testing in critically ill patients

Continuous renal replacement therapy versus intermittent hemodialysis in intensive care patients: impact on mortality and renal recovery.

PURPOSE: The best renal replacement therapy (RRT) modality remains controversial. We compared mortality and short- and long-term renal recovery between patients treated with continuous RRT and intermittent hemodialysis. METHODS: Patients of the prospective observational multicenter cohort database OUTCOMEREA were included if they underwent at least one RRT session between 2004 and 2014. Differences in patients' baseline and daily characteristics between treatment groups were taken into account by using a marginal structural Cox model, allowing one to substantially reduce the bias resulting from confounding factors in observational longitudinal data analysis. The composite primary endpoint was 30-day mortality and dialysis dependency. RESULTS: Among 1360 included patients with RRT, 544 (40.0 %) and 816 (60.0 %) were initially treated by continuous RRT and intermittent hemodialysis, respectively. At day 30, 39.6 % patients were dead. Among survivors, 23.8 % still required RRT. There was no difference between groups for the primary endpoint in global population (HR 1.00, 95 % CI 0.77-1.29; p = 0.97). In patients with higher weight gain at RRT initiation, mortality and dialysis dependency were significantly lower with continuous RRT (HR 0.54, 95 % CI 0.29-0.99; p = 0.05). Conversely, this technique appeared to be deleterious in patients without shock (HR 2.24, 95 % CI 1.24-4.04; p = 0.01). Six-month mortality and persistent renal dysfunction were not influenced by the RRT modality in patients with dialysis dependence at ICU discharge. CONCLUSION: Continuous RRT did not appear to improve 30-day and 6-month patient outcomes. It seems beneficial for patients with fluid overload, but might be deleterious in the absence of hemodynamic failure

Direct metal gate 40nm planar double gate CMOS by bonding for multipurpose applications,

International audienc