8 research outputs found

    Development of non-destructive analytical strategies based on Raman spectroscopy and complementary techniques for Mars Sample Return tested on Northwest Africa 1950 Martian meteorite

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    The Mars Sample Return (MSR) is a near future mission to return samples from the surface of Mars to the Earth. The field operations to carry out data collection, selection of the samples, and sampling procedure, mainly related to the CanMars MSR analog mission, are well-studied and published. In contrast, studies related to the methodology implemented to characterize the mineralogy of the returned samples are scarcer and focused on biosignature detection. This work presents a non-destructive analytical methodology based on Raman microscopy (single point and imaging), micro-energy dispersive X-ray fluorescence imaging analysis, and scanning electron microscopy coupled to energy dispersive spectroscopy that could be used as a first analytical characterization for the Martian samples that will be returned to the Earth in the upcoming MSR mission, before any destructive analysis. The analytical methodology has been tested on a fragment of the Northwest Africa 1950 Martian meteorite, which gives us a mineralogical characterization of the meteorite. This methodology also allowed to define several chemical reactions taking place in some of the mineral phases (olivines and ilmenite) of the meteorite. In addition to the geochemical characterization of the samples, the fact that this methodology allows to assess the chemical transformations in several minerals gives important clues for describing mineral processes and geological evolution that took place on Mars. This work also shows the advantages and disadvantages that each of the techniques employed has when performing a mineralogical characterization, the information that each one can provide and the importance of combining them.This work has been financially supported through the RamOnMars project: “Contribution of the Raman spectroscopy to the exploration of Mars and Martian Moons: ExoMars, Mars 2020, and MMX missions” (Grant ESP2017-87690-C3-1-R), funded by the Spanish Ministry of Science and Innovation (MICINN) and the European Regional Development Fund (FEDER) and by the Spanish Agency for Research (AEI-MINECO/FEDER) through the Project Science and Instrumentation for the Study of (bio)geochemical processes in Mars (Sigue-Mars), Grant no. RED2018-102600-T. C. García-Florentino is grateful to the Basque Government for her Postdoctoral Grant. J. Huidobro is grateful to the Basque Government for her Predoctoral contract. I. Torre-Fdez acknowledges his predoctoral contract from the University of the Basque Country (UPV/EHU). J. Aramendia is grateful to the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 754513 and The Aarhus University Research Foundation for her fellowship. The authors thank the General Service of Electron Microscopy and Materials Microanalysis Laboratory from the SGIker (UPV/EHU, MICINN, GV/EJ, ERDF and ESF) of the University of the Basque Country for their collaboration in the analyses

    Bounds on new physics with data of the Dresden-II reactor experiment and COHERENT

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    Coherent elastic neutrino-nucleus scattering was first experimentally established five years ago by the COHERENT experiment using neutrinos from the spallation neutron source at Oak Ridge National Laboratory. The first evidence of observation of coherent elastic neutrino-nucleus scattering with reactor antineutrinos has now been reported by the Dresden-II reactor experiment, using a germanium detector. In this paper, we present constraints on a variety of beyond the Standard Model scenarios using the new Dresden-II data. In particular, we explore the constraints imposed on neutrino non-standard interactions, neutrino magnetic moments, and several models with light scalar or light vector mediators. We also quantify the impact of their combination with COHERENT (CsI and Ar) data. In doing so, we highlight the synergies between spallation neutron source and nuclear reactor experiments regarding beyond the Standard Model searches, as well as the advantages of combining data obtained with different nuclear targets. We also study the possible signal from beyond the Standard Model scenarios due to elastic scattering off electrons (which would pass selection cuts of the COHERENT CsI and the Dresden-II experiments) and find more stringent constraints in certain parts of the parameter space than those obtained considering coherent elastic neutrino-nucleus scattering

    Weathering alteration in the Antarctic environment as seen in the Miller Range (MIL) 090030 Martian meteorite

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    The analysis of Martian meteorites is a key research to understand the mineralogical composition of Mars. However, they suffer different types of alteration due to the environment where they fall on Earth. These differences should be identified in order to characterize correctly the original Martian compounds. Most of the meteorites found on Earth are collected in Antarctica where the environmental conditions are such that, in general and based on many previous investigations, produce fewer alterations compared with other terrestrial environments such as hot deserts. In this study, the weathering alterations of minerals from the MIL 090030 Martian Nakhlite found in Antarctica were analyzed to determine which minerals are formed by Antarctic environmental conditions. It was confirmed that the south-polar region environment can contaminate Martian meteorites and, in this study, several minerals like halite, nitratine and niter, were detected as weathering alteration products that have not been referenced in the literature before.This study has been supported through the PAMMAT project ‘Alteration processes in Mars and Moon Meteorites, and Terrestrial Analogues at different environments: Mars2020, Rosalind Franklin and Returned Samples from Mars and Moon’ (Grant No. PID2022-142750OB-I00), funded by the Spanish Agency for Research (through the Spanish Ministry of Science and Innovation, MCIN, and the European Regional Development Fund, FEDER), and the Strategic Project ‘Study of Alteration Processes in Terrestrial and Planetary Materials’ (Grant No. UPV/EHU PES21/88), funded by the UPV/EHU. J. Aramendia is grateful to the University of the Basque Country and the Ministry of Universities for her post-doctoral Maria Zambrano position. Open Access funding by University of Basque Country

    The SuperCam Instrument onboard Perseverance: Overview of efforts compiled for Mars X conference

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    International audienceThe Perseverance rover landed at Jezero crater on February 18th, 2021. The choice of this landing site for the Mars2020 mission was motivated by its geological significance and the potential insights into Mars’ past habitability and search for past life. Indeed, Jezero crater once contained a lake, with a very well preserved delta on the west, making it an ideal location to search for signs of ancient microbial life. The Perseverance rover has four main objectives: 1. Search for traces of past microbial life 2. Characterize Mars’s climate and geology in the landing site 3. Collect samples for later return to Earth 4.Test technologies for future missions. Perseverance is equipped with seven scientific instruments, including the SuperCam suite [1,2]. SuperCam combines several remote-sensing techniques in order tostudy both the Martian surface and its atmosphere: 1. the LIBS (Laser-Induced Breakdown Spectroscopy) technique gives access to the chemical composition of the targets (up to 15m). All major elements are quantified (Si, Ti, Al, Fe, Mg, Ca, Na, K [3]) and the quantification of some minor elements is under progress [4]; 2. The Raman spectroscopy enables the identification of major mineral phases via the use of a 532nm pulsed laser, for Raman shifts between 150 and >4000cm-1; 3. The VISIR spectroscopy gives access to the mineralogy, via the reflection of sunlight to access the frequency of molecule bond vibrations of the targets. The VIS range covers the 379-464nm and 535-855nm range, and the IRS part is comprised in the 1.3-2.6 microns range using an Acousto-Optic Tunable Filter spectrometer [5]; 4. The Remote Micro Imager (RMI) uses a CMOS camera of 2048x2048 pixels, with an angular size of 10 microradians and a resolution of 50 microradians; 5. The microphone records air pressure fluctuations from 20 Hz to 12.5 or 50 KHz, at sampling rates of 25 or 100 KHz, respectively

    Prognostic Role of TAPSE to PASP Ratio in Patients Undergoing MitraClip Procedure.

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    Transcatheter mitral valve repair (TMVR) is an effective therapy for high-risk patients with severe mitral regurgitation (MR) but heart failure (HF) readmissions and death remain substantial on mid-term follow-up. Recently, right ventricular (RV) to pulmonary arterial (PA) coupling has emerged as a relevant prognostic predictor in HF. In this study, we aimed to assess the prognostic value of tricuspid annular plane systolic excursion (TAPSE) to PA systolic pressure (PASP) ratio as a non-invasive measure of RV-to-PA coupling in patients undergoing TMVR with MitraClip (Abbott, CA, USA). Multicentre registry including 228 consecutive patients that underwent successful TMVR with MitraClip. The sample was divided in two groups according to TAPSE/PASP median value: 0.35. The primary combined endpoint encompassed HF readmissions and all-cause mortality. Mean age was 72.5 ± 11.5 years and 154 (67.5%) patients were male. HF readmissions and all-cause mortality were more frequent in patients with TAPSE/PASP ≤ 0.35: Log-Rank 8.844, p = 0.003. On Cox regression, TAPSE/PASP emerged as a prognostic predictor of the primary combined endpoint, together with STS-Score. TAPSE/PASP was a better prognostic predictor than either TAPSE or PASP separately. TAPSE/PASP ratio appears as a novel prognostic predictor in patients undergoing MitraClip implantation that might improve risk stratification and candidate selection

    Transcatheter mitral repair according to the cause of mitral regurgitation: real-life data from the Spanish MitraClip registry.

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    Transcatheter mitral valve repair (TMVR) with MitraClip is a therapeutic option for high surgical risk patients with severe mitral regurgitation (MR). The main objective of this study was to analyze differences in outcomes in patients with severe MR according to the cause of MR. Observational, multicenter, and prospective study with consecutive patient inclusion. The primary endpoint was the combination of all-cause mortality and new readmissions due to heart failure after 1 year. We compared clinical and procedural characteristics and the event rate for each MR group. We performed a multivariate analysis to identify predictive variables for the primary endpoint. A total of 558 patients were included: 364 (65.2%) with functional etiology, 111 (19.9%) degenerative and 83 (14.9%) mixed. The mean age was 72.8±11.1 years and 70.3% of the sample were men. There were 95 (17%) events in the overall sample. No significant differences were found in the 3 groups in the number of primary outcome events: 11 (11.3%) in degenerative MR, 71 (21.3%) in functional MR, and 13 (18.1%) in mixed MR (P=.101). Independent predictors were functional class (P=.029), previous surgical revascularization (P=.031), EuroSCORE II (P=.003), diabetes mellitus (P=.037), and left ventricular ejection fraction (P=.015). This study confirms the safety and efficacy of TMVR with MitraClip irrespective of MR etiology in real-life data and shows the main factors related to prognosis during the first year of follow up

    Transcatheter Mitral Repair for Functional Mitral Regurgitation According to Left Ventricular Function: A Real-Life Propensity-Score Matched Study

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    Background: Transcatheter mitral valve repair (TMVR) could improve survival in functional mitral regurgitation (FMR), but it is necessary to consider the influence of left ventricular ejection fraction (LVEF). Therefore, we compare the outcomes after TMVR with Mitraclip® between two groups according to LVEF. Methods: In an observational registry study, we compared the outcomes in patients with FMR who underwent TMVR with and without LVEF <30%. The primary endpoint was the combined one-year all-cause mortality and unplanned hospital readmissions due to HF. The secondary end-points were New York Heart Association (NYHA) functional class and mitral regurgitation (MR) severity. Propensity-score matching was used to create two groups with the same baseline characteristics, except for baseline LVEF. Results: Among 535 FMR eligible patients, 144 patients with LVEF <30% (group 1) and 144 with LVEF >30% (group 2) had similar propensity scores and were included in the analyses. The primary study endpoint was significantlly higher in group 1 (33.3% vs. 9.4%, p = 0.002). There was a maintained improvement in secondary endpoints without significant differences among groups. Conclusion: FMR patients with LVEF <30% treated with MitraClip® had higher mortality and readmissions than patients with LVEF ≥30% treated with the same device. However, both groups improved the NYHA functional class and MR severity

    Radiation-induced alteration of apatite on the surface of Mars: first in situ observations with SuperCam Raman onboard Perseverance

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    International audiencePlanetary exploration relies considerably on mineral characterization to advance our understanding of the solar system, the planets and their evolution. Thus, we must understand past and present processes that can alter materials exposed on the surface, affecting space mission data. Here, we analyze the first dataset monitoring the evolution of a known mineral target in situ on the Martian surface, brought there as a SuperCam calibration target onboard the Perseverance rover. We used Raman spectroscopy to monitor the crystalline state of a synthetic apatite sample over the first 950 Martian days (sols) of the Mars2020 mission. We note significant variations in the Raman spectra acquired on this target, specifically a decrease in the relative contribution of the Raman signal to the total signal. These observations are consistent with the results of a UV‑irradiation test performed in the laboratory under conditions mimicking ambient Martian conditions. We conclude that theobserved evolution reflects an alteration of the material, specifically the creation of electronic defects, due to its exposure to the Martian environment and, in particular, UV irradiation. This ongoing process of alteration of the Martian surface needs to be taken into account for mineralogical space mission data analysis
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