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The CCQM-K78.b key comparison was coordinated by the Bureau International des Poids et Mesures (BIPM) on behalf of the CCQM Organic Analysis Working Group (OAWG) of the 'Comité Consultatif pour la Quantité de Matière' (CCQM), for National Measurement Institutes (NMIs) and Designated Institutes (DIs) providing measurement services in organic analysis under the 'Comité International des Poids et Mesures' (CIPM) Mutual Recognition Arrangement (MRA). This key comparison was conducted as a 'Track A' comparison within the OAWG's 10-year strategic plan. The goal of CCQM-K78.b was to underpin capabilities for the value assignment of calibration solutions containing low polarity/non-polar organic analytes in organic solvents. The selected model system consisted of a two-component pesticide solution in acetonitrile, comprising methoxychlor and trifluralin. Participants were tasked with assigning the mass fractions, in units of μg/g, of methoxychlor and trifluralin in acetonitrile solution. The mass fraction levels and analytical challenges of the selected analytes were representative of those encountered for calibration solutions of non-polar organic analytes. Participation in CCQM-K78.b allowed for the benchmarking of capabilities for assigning the mass fraction of non-polar organic compounds (pKow < -2) in solution, at mass fractions above 5 μg/g, in an organic solvent. Additionally, the comparison assessed the capabilities for the quantitative assignment of thermally labile compounds. Participants were provided by the BIPM with ampoules containing methoxychlor and trifluralin in acetonitrile. Each participant reported the mass fraction content of each analyte in μg/g. All participants ensured the metrological traceability of their results through the use of a Primary Reference Material (PRM), which was used to prepare a primary calibrator solution for each analyte using a gravimetric procedure. The twenty participating institutes primarily used analysis procedures based on GC-MS, -IDMS, -MS/MS, -ECD, and -FID, with some participants also using LC-UV for the value assignment. The analysis of methoxychlor and trifluralin in acetonitrile solution presented several challenges, including the thermal stability of the analytes under selected analytical techniques, control of solvent volatility, and considerable variation in some results using MS-based quantification methods. The mass fraction assignments for methoxychlor and trifluralin, consistent with the key comparison reference values (KCRVs), were achieved with associated relative standard uncertainties of (0.38 - 2.9) % for methoxychlor and (0.35 - 2.5) % for trifluralin. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Rice is staple food of nearly half the world’s population. Rice yields must therefore increase to feed ever larger populations. By colonising rice and other plants, Herbaspirillum spp. stimulate plant growthand productivity. However the molecular factors involved are largely unknown. To further explore this interaction, the transcription profiles of Nipponbare rice roots inoculated with Herbaspirillum seropedicae were determined by RNA-seq. Mapping the 104 million reads against the Oryza sativa cv. Nipponbare genome produced 65 million unique mapped reads that represented 13,840 transcripts each with at least two-times coverage. About 7.4% (1,014) genes were differentially regulated and of these 255 changed expression levels more than two times. Several of the repressed genes encoded proteins related to plant defence (e.g. a putative probenazole inducible protein), plant disease resistance as well as enzymes involved in flavonoid and isoprenoid synthesis. Genes related to the synthesis and efflux of phytosiderophores (PS) and transport of PS-iron complexes were induced by the bacteria. These data suggest that the bacterium represses the rice defence system while concomitantly activating iron uptake. Transcripts of H. seropedicae were also detected amongst which transcripts of genes involved in nitrogen fixation, cell motility and cell wall synthesis were the most expressed.

The paper presents a comparison between two different numerical modelling approaches aimed to simulate the in-plain behaviour of rammed earth walls, namely under axial, diagonal and cyclic shearcompression loading. In the first part of the study the mechanical characterisation of wallets tested under uniaxial compression and diagonal compression and walls tested under in-plane cyclic shear-compression loading is presented. The results were used to implement and validate the finite element simulations. The numerical modelling of the rammed earth samples tested is then discussed in the second part. A non-linear constitutive law based on the total strain rotating crack model (TSRCM) was employed as implemented in the DIANA® software. The aim of the numerical analyses presented here is to simulate the behaviour of rammed earth under different inplane loading conditions. For the wallets, tests under static loading both macro- and micro-modelling approaches were considered for the simulation of the experimental tests. For the walls subjected to cyclic loading only the micro-modelling approach was applied for the simulation of the experimental tests. The respective FEM model was calibrated with the experimental results. The rammed earth layers were represented by continuum elements, the contact surfaces between layers by interface elements. This approach allowed assessing the influence of the apparent weakness of the interfaces between layers on the shear behaviour of rammed earth. The goal of the numerical simulation of the cyclic tests was to establish the adequacy of common analytical methods (e. g. used for masonry) applied to the analysis of rammed earth. Rammed earth exhibits brittle characteristics similar to masonry materials and is used in geometrical typologies, such as walls, common in masonry construction.

Objectives: Using a murine model of multiple sclerosis, we previously showed that repeated administration of gadopentetate dimeglumine led to retention of gadolinium (Gd) within cerebellar structures and that this process was enhanced with inflammation. This study aimed to compare the kinetics and retention profiles of Gd in inflamed and healthy brains after application of the macrocyclic Gd-based contrast agent (GBCA) gadobutrol or the linear GBCA gadopentetate. Moreover, potential Gd-induced neurotoxicity was investigated in living hippocampal slices ex vivo. Materials and Methods: Mice at peak of experimental autoimmune encephalomyelitis (EAE; n = 29) and healthy control mice (HC; n = 24) were exposed to a cumulative dose of 20 mmol/kg bodyweight of either gadopentetate dimeglumine or gadobutrol (8 injections of 2.5 mmol/kg over 10 days). Magnetic resonance imaging (7 T) was performed at baseline as well as at day 1, 10, and 40 post final injection (pfi) of GBCAs. Mice were sacrificed after magnetic resonance imaging and brain and blood Gd content was assessed by laser ablation-inductively coupled plasma (ICP)-mass spectrometry (MS) and ICP-MS, respectively. In addition, using chronic organotypic hippocampal slice cultures, Gd-induced neurotoxicity was addressed in living brain tissue ex vivo, both under control or inflammatory (tumor necrosis factor α [TNF-α] at 50 ng/μL) conditions. Results: Neuroinflammation promoted a significant decrease in T1 relaxation times after multiple injections of both GBCAs as shown by quantitative T1 mapping of EAE brains compared with HC. This corresponded to higher Gd retention within the EAE brains at 1, 10, and 40 days pfi as determined by laser ablation-ICP-MS. In inflamed cerebellum, in particular in the deep cerebellar nuclei (CN), elevated Gd retention was observed until day 40 after last gadopentetate application (CN: EAE vs HC, 55.06 ± 0.16 μM vs 30.44 ± 4.43 μM). In contrast, gadobutrol application led to a rather diffuse Gd content in the inflamed brains, which strongly diminished until day 40 (CN: EAE vs HC, 0.38 ± 0.08 μM vs 0.17 ± 0.03 μM). The analysis of cytotoxic effects of both GBCAs using living brain tissue revealed an elevated cell death rate after incubation with gadopentetate but not gadobutrol at 50 mM. The cytotoxic effect due to gadopentetate increased in the presence of the inflammatory mediator TNF-α (with vs without TNF-α, 3.15% ± 1.18% vs 2.17% ± 1.14%; P = 0.0345). Conclusions: In the EAE model, neuroinflammation promoted increased Gd retention in the brain for both GBCAs. Whereas in the inflamed brains, efficient clearance of macrocyclic gadobutrol during the investigated time period was observed, the Gd retention after application of linear gadopentetate persisted over the entire observational period. Gadopentetate but not gadubutrol appeared to be neurotoxic in an ex vivo paradigm of neuronal inflammation.

Carbidic Austempered Ductile Iron (CADI) microstructures containing eutectic carbides can be produced by the addition of carbide stabilizing elements, such as chromium. Carbides formed from the addition of Cr are eutectic of M3C type. The presence of such hard phases can enhance the abrasion wear resistance of ductile iron. A new CADI can be produced by the addition of Nb. Niobium carbide particles are formed in the beginning of solidification and remain stable once they are insoluble in solid iron matrix. The dry sand abrasive wear resistance of ductile irons alloyed with 1.0, 1.8, and 2.4 wt% Nb were tested in both “as-cast” and “heat treated” conditions using standard ASTM G65. Results were compared to abrasive wear data obtained on ductile iron alloyed with 1 wt% Cr, CADI (1 wt% Cr), and the basic composition of iron without carbide stabilizing elements. In the “ascast” condition, the addition of Nb did not lead to a reduction in wear, while CADI with Nb is a promising substitute for CADI with Cr addition, because both materials showed very similar values of abrasion resistance. Micro-ploughing and micro-cutting mechanisms were observed on the worn surfaces of ductile irons. Abrasive wear resistance of these alloys was correlated with the volume fraction of carbides.