Suchergebnisse

Recent developments in in situ nuclear magnetic resonance (NMR) spectroscopy under extreme conditions have led to the observation of a wide variety of physical phenomena that are not accessible with standard high-pressure experimental probes. However, inherent di- or quadrupolar line broadening in diamond anvil cell (DAC)-based NMR experiments often limits detailed investigation of local atomic structures, especially if different phases or local environments coexist. Here, we describe our progress in the development of high-resolution NMR experiments in DACs using one- and two-dimensional homonuclear decoupling experiments at pressures up to the megabar regime. Using this technique, spectral resolutions of the order of 1 ppm and below have been achieved, enabling high-pressure structural analysis. Several examples are presented that demonstrate the wide applicability of this method for extreme conditions research. ; Funding: German Research Foundation (Deutsche Forschungsgemeinschaft, DFG)German Research Foundation (DFG) [DU 954/11-1, DU 393/13-1, DU 393/9-2]; Federal Ministry of Education and Research, Germany (BMBF)Federal Ministry of Education & Research (BMBF) [05K19WC1]; Center for High Pressure Science and Technology Advanced Research; Swedish Research Council (VR)Swedish Research Council [2019-05600]; Alexander von Humboldt FoundationAlexander von Humboldt Foundation; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [2009 00971]; [ME 5206/3-1]

Funding This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 668119 (project "IDentIFY"). ; Peer reviewed ; Publisher PDF

Este artículo contiene 16 páginas, 5 figuras, 1 tabla. ; In pigs, ejaculate is expelled in fractions, mainly the sperm-rich fraction (SRF) and the post-SRF (PSRF), which differ in both sperm content and origin. In addition, intra-ejaculate variability between fractions in terms of sperm reproductive characteristics has been previously reported, the highest sperm quality being observed in the first 10 mL of the SRF (SRF-P1). As seminal plasma (SP) composition has been purported to influence sperm physiology, the aim of this study was to profile pig SP metabolite composition and to find putative differences between the ejaculate portions (SRF-P1, the rest of SRF [SRF-P2], PSRF) and entire ejaculate (EE). To this end, ejaculates (n = 8, one per boar) were collected in fractions and SP was analyzed using 1H Nuclear Magnetic Resonance spectroscopy. We identified 19 metabolites present in all ejaculate portions and the EE, and reported correlations between the metabolites. Additionally, and for the first time in mammals, we found intra-ejaculate variability in the SP metabolites, observing different relative abundances in choline, glycerophosphocholine and glycine. Regarding their influence in sperm physiology, we hypothesize that these metabolites may explain the specific reproductive characteristics of each ejaculate portion. Finally, the reported SP metabolites could serve as a first steppingstone in the study of quality, functionality, and fertility biomarkers ; The present study has been funded by the Ministry of Science and Innovation, Spain (Grants: RYC-2014-15581, AGL2017-88329-R and FJCI-2017-31689) and the Regional Government of Catalonia (Grants: 2019-SGR-1229 and 2020-FI-B-00412). ; Peer reviewed

Wasser ist nicht nur die Quelle des Lebens, der Zugang zu Trinkwasser ist auch ein anerkanntes Menschenrecht. Die Methode der Kernspinresonanz (NMR) erlaubt es detaillierte Informationen über Ausdehnung und hydraulischen Eigenschaften von Aquiferen zu sammeln. Dies stellt eine wesentliche Voraussetzung für deren nachhaltige Nutzung dar. Die wichtigsten Ziele dieser Arbeit sind (i) die verbesserte Ableitung der hydraulischen Leitfähigkeit aus NMR-Messungen, insbesondere an groben Lockermaterial, und (ii) die Entwicklung eines Inversionsansatzes für Oberflächen-NMR-Messungen zur Ableitung der 2D-Verteilung von Wassergehalt und NMR-Relaxationszeit im Untergrund. Das Kozeny-Godefroy-Modell erlaubt eine verbesserte Ableitung der hydraulischen Leitfähigkeit aus NMR-Messungen. Es ersetzt die empirischen Faktoren in bekannten Gleichungen mit physikalischen, strukturellen und NMR-spezifischen Parametern und berücksichtigt den Relaxationsprozess von Protonen in freiem Wasser und in diffusionskontrollierten Porenräumen. Der neue Inversionsansatz zur Auswertung von 2D Oberflächen-NMRMessungen berücksichtigt den kompletten Datensatz in einem Arbeitsschritt und bestimmt daraus die 2D-Verteilung von Wassergehalt und NMRRelaxationszeit im Untergrund. Herausragenden Eigenschaften des Inversionsansatzes sind dessen 2D-Fähigkeit und erhöhte Widerstandsfähigkeit gegenüber verrauschten Daten. Zudem ermöglicht die NMR-Relaxationszeit die Unterscheidung verschiedener Lithologien. Die Ergebnisse einer umfangreichen hydrogeophysikalischen Untersuchung am Teststandort Schillerslage, bestehend aus Oberflächen-, Erdfeld-, Bohrloch- und Labor-NMR-Messungen, werden vorgestellt, verglichen und diskutiert. Aus den gewonnenen NMR-Parametern werden die 1D- und 2D-Verteilungen der hydraulischen Leitfähigkeit im Untergrund abgeleitet. Als Fazit der Arbeit kann gesagt werden, dass das Kozeny-Godefroy-Modell die Ableitung der hydraulischen Leitfähigkeiten in Aquiferen aus NMR-Messungen verbessert und der neue Inversionsansatz den Anwendungsbereich von Oberflächen-NMR auf 2D-Ziele vergrößert. In Kombination erlauben beide Neuerungen die Abbildung der 2D-Verteilung der hydraulischen Leitfähigkeit im Untergrund. ; Not only is water the source of life, but access to clean drinking water is acknowledged to be a human right. Nuclear magnetic resonance (NMR) can help to gather detailed information about the extent and hydraulic properties of an aquifer which are essential information for a sustainable use. The main objectives of this thesis are (i) to revise the prediction of hydraulic conductivities including coarse-grained unconsolidated sediments using NMR and (ii) to develop a robust inversion approach for surface NMR to estimate the 2D distribution of water content and NMR relaxation time in the subsurface. The Kozeny-Godefroy model is introduced which allows for an advanced prediction of hydraulic conductivity from NMR measurements. The model replaces the empirical factors in known relations with physical, structural and NMR intrinsic parameters. It additionally accounts for the relaxation of protons in the bulk water and in pores which are controlled by diffusion limited conditions. A new sophisticated inversion approach for 2D surface NMR surveys is presented. It considers the entire recorded data set at once allowing to determine the 2D distribution of water content and NMR relaxation time in the subsurface. The outstanding features of this new inversion approach are its 2D capability, robustness in spite of noisy data and the potential to distinguish aquifers of different lithology due to their NMR relaxation times. Finally, the results of an extensive hydrogeophysical study at the Schillerslage test site, including surface, Earth's field, borehole and laboratory NMR measurements, are presented, compared and discussed. The obtained NMR parameters are used for the prediction of 1D and 2D distributions of the hydraulic conductivity in the subsurface. In conclusion, this thesis demonstrates that the estimation of hydraulic conductivities in aquifers using NMR can be improved using the Kozeny-Godefroy model. The presented new inversion approach increases the range of application for surface NMR to 2D targets. This allows obtaining 2D images of the hydraulic conductivity distribution in the subsurface.

In pigs, ejaculate is expelled in fractions, mainly the sperm-rich fraction (SRF) and the post-SRF (PSRF), which differ in both sperm content and origin. In addition, intra-ejaculate variability between fractions in terms of sperm reproductive characteristics has been previously reported, the highest sperm quality being observed in the first 10 mL of the SRF (SRF-P1). As seminal plasma (SP) composition has been purported to influence sperm physiology, the aim of this study was to profile pig SP metabolite composition and to find putative differences between the ejaculate portions (SRF-P1, the rest of SRF [SRF-P2], PSRF) and entire ejaculate (EE). To this end, ejaculates (n = 8, one per boar) were collected in fractions and SP was analyzed using 1H Nuclear Magnetic Resonance spectroscopy. We identified 19 metabolites present in all ejaculate portions and the EE, and reported correlations between the metabolites. Additionally, and for the first time in mammals, we found intra-ejaculate variability in the SP metabolites, observing different relative abundances in choline, glycerophosphocholine and glycine. Regarding their influence in sperm physiology, we hypothesize that these metabolites may explain the specific reproductive characteristics of each ejaculate portion. Finally, the reported SP metabolites could serve as a first steppingstone in the study of quality, functionality, and fertility biomarkers ; The present study has been funded by the Ministry of Science and Innovation, Spain (Grants:RYC-2014-15581, AGL2017-88329-R and FJCI-2017-31689) and the Regional Government of Catalonia (Grants: 2019-SGR-1229 and 2020-FI-B-00412)

Acknowledgement This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 668119 (project "IDentIFY"). ; Peer reviewed ; Publisher PDF

This project has received funding from the European Union's Horizon 2020 research and innovation programme under project "IDentIFY", grant agreement No 668119. ; Peer reviewed ; Publisher PDF

The results of experimental studies are presented, determining the internal defects of potato tubers using nuclear magnetic resonance (NMR) method, which provide access to information about the state and distribution of water at the cellular and tissue levels. In order to carry out internal defect detection studies, three groups of potato tubers were prepared, comprising conditioned and unconditioned samples. The total sampling of potato tubers amounted to 38 samples. To create hidden defects in the form of darkening of tuber pulp, the method of controlled impact on a hard surface was used. Methodology for conducting experimental studies and time parameters of NMR are described. The studied potato tubers were placed in a strong magnetic field with intensity of 1.5 Tesla. Analysis of T2 images was chosen as the main method for analyzing the obtained results, since this method allows to trace one of the most important indicators of detecting internal damage of potato tubers – lack of water in the damaged areas of the pulp. The damaged areas in the images of tubers have a dark color, while the healthy tissue is light. A comparative analysis of images obtained using NMR and full-scale images of tubers' section was carried out, allowing to determine with high accuracy the coincidence of location of defects detected by non-invasive method with their actual location in the tuber. The study showed the value of NMR for a detailed non-invasive method for determining hidden defects in potato tubers on automatic grading machines.

ACKNOWLEDGEMENTS We acknowledge ARUK (Versus Arthritis) for funding this study (grant number 19869) and the NHS Grampian Biorepository for the access to cartilage samples. BWCK received a Foulkes Foundation Fellowship. This project has also received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 668119 (project "IDentIFY") and NHS Grampian endowments. This work received support from the EURELAX COST Action CA15209, supported by COST (European Cooperation in Science and Technology). ; Peer reviewed ; Publisher PDF