Mineralogical and geochemical analysis of Fe-phases in drill-cores from the Triassic Stuttgart Formation at Ketzin CO₂ storage site before CO₂ arrival

Reactive iron (Fe) oxides and sheet silicate-bound Fe in reservoir rocks may affect the subsurface storage of CO2 through several processes by changing the capacity to buffer the acidification by CO2 and the permeability of the reservoir rock: (1) the reduction of three-valent Fe in anoxic environments can lead to an increase in pH, (2) under sulphidic conditions, Fe may drive sulphur cycling and lead to the formation of pyrite, and (3) the leaching of Fe from sheet silicates may affect silicate diagenesis. In order to evaluate the importance of Fe-reduction on the CO2 reservoir, we analysed the Fe geochemistry in drill-cores from the Triassic Stuttgart Formation (Schilfsandstein) recovered from the monitoring well at the CO2 test injection site near Ketzin, Germany. The reservoir rock is a porous, poorly to moderately cohesive fluvial sandstone containing up to 2–4 wt% reactive Fe. Based on a sequential extraction, most Fe falls into the dithionite-extractable Fe-fraction and Fe bound to sheet silicates, whereby some Fe in the dithionite-extractable Fe-fraction may have been leached from illite and smectite. Illite and smectite were detected in core samples by X-ray diffraction and confirmed as the main Fe-containing mineral phases by X-ray absorption spectroscopy. Chlorite is also present, but likely does not contribute much to the high amount of Fe in the silicate-bound fraction. The organic carbon content of the reservoir rock is extremely low (<0.3 wt%), thus likely limiting microbial Fe-reduction or sulphate reduction despite relatively high concentrations of reactive Fe-mineral phases in the reservoir rock and sulphate in the reservoir fluid. Both processes could, however, be fuelled by organic matter that is mobilized by the flow of supercritical CO2 or introduced with the drilling fluid. Over long time periods, a potential way of liberating additional reactive Fe could occur through weathering of silicates due to acidification by CO2

GPAW: open Python package for electronic-structure calculations

We review the GPAW open-source Python package for electronic structure calculations. GPAW is based on the projector-augmented wave method and can solve the self-consistent density functional theory (DFT) equations using three different wave-function representations, namely real-space grids, plane waves, and numerical atomic orbitals. The three representations are complementary and mutually independent and can be connected by transformations via the real-space grid. This multi-basis feature renders GPAW highly versatile and unique among similar codes. By virtue of its modular structure, the GPAW code constitutes an ideal platform for implementation of new features and methodologies. Moreover, it is well integrated with the Atomic Simulation Environment (ASE) providing a flexible and dynamic user interface. In addition to ground-state DFT calculations, GPAW supports many-body GW band structures, optical excitations from the Bethe-Salpeter Equation (BSE), variational calculations of excited states in molecules and solids via direct optimization, and real-time propagation of the Kohn-Sham equations within time-dependent DFT. A range of more advanced methods to describe magnetic excitations and non-collinear magnetism in solids are also now available. In addition, GPAW can calculate non-linear optical tensors of solids, charged crystal point defects, and much more. Recently, support of GPU acceleration has been achieved with minor modifications of the GPAW code thanks to the CuPy library. We end the review with an outlook describing some future plans for GPAW

Gut microbiome composition is linked to whole grain-induced immunological improvements

The involvement of the gut microbiota in metabolic disorders, and the ability of whole grains to affect both host metabolism and gut microbial ecology, suggest that some benefits of whole grains are mediated through their effects on the gut microbiome. Nutritional studies that assess the effect of whole grains on both the gut microbiome and human physiology are needed. We conducted a randomized cross-over trial with four-week treatments in which 28 healthy humans consumed a daily dose of 60 g of whole-grain barley (WGB), brown rice (BR), or an equal mixture of the two (BR+WGB), and characterized their impact on fecal microbial ecology and blood markers of inflammation, glucose and lipid metabolism. All treatments increased microbial diversity, the Firmicutes/Bacteroidetes ratio, and the abundance of the genus Blautia in fecal samples. The inclusion of WGB enriched the genera Roseburia, Bifidobacterium and Dialister, and the species Eubacterium rectale, Roseburia faecis and Roseburia intestinalis. Whole grains, and especially the BR+WGB treatment, reduced plasma interleukin-6 (IL-6) and peak postprandial glucose. Shifts in the abundance of Eubacterium rectale were associated with changes in the glucose and insulin postprandial response. Interestingly, subjects with greater improvements in IL-6 levels harbored significantly higher proportions of Dialister and lower abundance of Coriobacteriaceae. In conclusion, this study revealed that a short-term intake of whole grains induced compositional alterations of the gut microbiota that coincided with improvements in host physiological measures related to metabolic dysfunctions in humans

Evaluation of gene expression analysis using RNA-targeted partial genome arrays

Highly parallel cDNA targeting microarrays have been established over the last years as the quasi-standard for genome wide expression profiling in pro- and eukaryotes. Protocols for the direct detection of RNA or aRNA (amplified RNA) are currently emerging. This allows to circumvent the bias introduced by enzymatic target molecule preparation. To systematically evaluate the extent of non-specific target binding on oligonucleotide microarrays designed for total RNA expression profiling, a model system of 70-mer probes targeting genes involved in magnetosome formation (mam genes) of the bacterium Magnetospirillum gryphiswaldense was established utilizing wild-type strain MSR-1 and an isogenic deletion mutant MSR-1B that lacks all mam genes. An optimized protocol for the direct chemical labelling of total cellular RNAs was used. A linear correlation between the amount of applied RNA and the mean global background intensity was found which enables a simple and unbiased way of normalizing the data. The results obtained with the mam deletion mutant MSR-1B revealed a significant number of false positive signals, even under optimal hybridization conditions. This indicates a high degree of non-specific binding in microarray experiments when using longer oligo- or polynucleotides and RNA as target molecule. Comparative microarray analysis of an MSR-1B culture and two MSR-1 wild-type cultures grown under different conditions was done via a three-colour hybridization assay. The additional information provided by the MSR-1B transcriptome revealed differential gene expression in the two MSR-1 cultures, which was otherwise undetectable

Differentiation in an inclusive trauma system : Allocation of lower extremity fractures

Background: Implementation of an inclusive trauma system leads to reduced mortality rates, specifically in polytrauma patients. Field triage is essential in this mortality reduction. Triage systems are developed to identify patients with life-threatening injuries, and trauma mechanisms are important for triaging. Although complex extremity fractures are mostly non-lethal, these injuries are frequently the result of a high-energy trauma mechanism. The aim of this study is to compare injury and patient characteristics, as well as resource demands, of lower extremity fractures between a level (L)1 and level (L)2 trauma centre in a mature inclusive trauma system. Methods: This is a retrospective cohort study. Patients with below-the-knee joint fractures diagnosed in a L1 or L2 trauma centre between July 2013 and June 2015 were included. Main outcome parameters were patient demographics, trauma mechanism, fracture pattern, and resource demands. Results: One thousand two hundred sixty-seven patients with 1517 lower extremity fractures were included. Most patients were treated in the L2 centre (L1=417; L2=859). Complex fractures were more frequently triaged to the L1 centre. Patients in the L1 centre had more concomitant injuries to other body regions and ipsi- or contralateral lower extremity. Patients in the L1 centre were more resource demanding: more surgeries (>1 surgery; 24.9% L1 vs 1.4% L2), higher immediate admission rates (70.1% L1 vs 37.6% L2), and longer length of stay (mean 13.4 days L1 vs 3.1 days L2). Conclusion: The majority of patients were treated in the L2 trauma centre, whereas complex lower extremity injuries were mostly treated in the L1 centre, which placed higher demand on resources and labour per patient. This change in allocation is the next step in centralization of low-volume high complex care and high-volume low complex care