Raman spectroscopy is among the top analytical techniques for ultra-low-dense organic matter, crucial to the search for life and analysis of celestial body surfaces in space exploration missions. Achieving the ultimate sensitivity of in-situ Raman spectroscopy necessitates a breakthrough in detecting inelastically scattered light. Single-photon detectors (SPDs) operating in photon counting mode, which can differentiate between Raman and luminescence responses, are promising candidates for the challenging scientific requirements.
View Article and Find Full Text PDFXanthoria parietina survivability in Mars-like conditions was supported by water-lysis efficiency recovery and antioxidant content balancing with ROS production after 30 days of exposure. Xanthoria parietina (L.) Th.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
December 2023
The main objective of the ongoing and future space exploration missions is the search for traces of extant or extinct life (biomarkers) on Mars. One of the main limiting factors on the survival of Earth-like life is the presence of harmful space radiation, that could damage or modify also biomolecules, therefore understanding the effects of radiation on terrestrial biomolecules stability and detectability is of utmost importance. Which terrestrial molecules could be preserved in a Martian radiation scenario? Here, we investigated the potential endurance of fungal biomolecules, by exposing de-hydrated colonies of the Antarctic cryptoendolithic black fungus Cryomyces antarcticus mixed with Antarctic sandstone and with two Martian regolith analogues to increasing doses (0, 250 and 1000 Gy) of accelerated ions, namely iron (Fe), argon (Ar) and helium (He) ions.
View Article and Find Full Text PDFThe effect of a Mars-like UV flux and γ-radiation on the detectability of biomarkers in dried cells of sp. CCMEE 029 was investigated using a fluorescence sandwich microarray immunoassay. The production of anti- antibodies allowed the immunoidentification of a reduced, though still detectable, signal in dried cells mixed with phyllosilicatic and sulfatic Mars regolith simulants after exposure to 6.
View Article and Find Full Text PDFTwo rover missions to Mars aim to detect biomolecules as a sign of extinct or extant life with, among other instruments, Raman spectrometers. However, there are many unknowns about the stability of Raman-detectable biomolecules in the martian environment, clouding the interpretation of the results. To quantify Raman-detectable biomolecule stability, we exposed seven biomolecules for 469 days to a simulated martian environment outside the International Space Station.
View Article and Find Full Text PDFUnderstanding the impact of long-term exposure of microorganisms to space is critical in understanding how these exposures impact the evolution and adaptation of microbial life under space conditions. In this work we subjected Nostoc sp. CCCryo 231-06, a cyanobacterium capable of living under many different ecological conditions, and also surviving in extreme ones, to a 23-month stay at the International Space Station (the Biology and Mars Experiment, BIOMEX, on the EXPOSE-R2 platform) and returned it to Earth for single-cell genome analysis.
View Article and Find Full Text PDFThe Nostoc sp. strain CCCryo 231-06 is a cyanobacterial strain capable of surviving under extreme conditions and thus is of great interest for the astrobiology community. The knowledge of its complete genome sequence would serve as a guide for further studies.
View Article and Find Full Text PDFThe Moon is characterized by extremely harsh conditions due to ultraviolet irradiation, wide temperature extremes, vacuum resulting from the absence of an atmosphere and high ionizing radiation. Therefore, its surface may provide a unique platform to investigate the effects of such conditions. For lunar exploration with the Lunar Gateway platform, exposure experiments in Low Earth Orbit are useful testbeds to prepare for lunar space experiments and to understand how and if potential biomarkers are influenced by extra-terrestrial conditions.
View Article and Find Full Text PDFBackground: Few data are available on the prognosis of older patients who received corticosteroids for COVID-19. We aimed to compare the in-hospital mortality of geriatric patients hospitalized for COVID-19 who received corticosteroids or not.
Methods: We conducted a multicentric retrospective cohort study in 15 acute COVID-19 geriatric wards in the Paris area from March to April 2020 and November 2020 to May 2021.
Organic molecules are prime targets in the search for life on other planetary bodies in the Solar System. Understanding their preservation potential and detectability after ionic irradiation, with fluences potentially representing those received for several millions to billions of years at Mars or in interplanetary space, is a crucial goal for astrobiology research. In order to be able to perform in situ characterization of such organic molecules under ionic irradiation in the near future, a feasibility experiment was performed with polymer test samples to validate the optical configuration and the irradiation chamber geometry.
View Article and Find Full Text PDFBackground: Advanced age is accompanied by a decline of immune functions, which may play a role in increased vulnerability to emerging pathogens and low efficacy of primary vaccinations in elderly people. The capacity to mount immune responses against new antigens is particularly affected in this population. However, its precise determinants are not fully understood.
View Article and Find Full Text PDFThe success of an astrobiological search for life campaign on Mars, or other planetary bodies in the Solar System, relies on the detectability of past or present microbial life traces, namely, biosignatures. Spectroscopic methods require little or no sample preparation, can be repeated almost endlessly, and can be performed in contact or even remotely. Such methods are therefore ideally suited to use for the detection of biosignatures, which can be confirmed with supporting instrumentation.
View Article and Find Full Text PDFThe discovery of life on other planets and moons in our solar system is one of the most important challenges of this era. The second ExoMars mission will look for traces of extant or extinct life on Mars. The instruments on board the rover will be able to reach samples with eventual biomarkers until 2 m of depth under the planet's surface.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
November 2021
The extremophile lichen Circinaria gyrosa (C. gyrosa) is one of the selected species within the BIOMEX (Biology and Mars Experiment) experiment. Here we present the Raman study of a biohint found in this lichen, called whewellite (calcium oxalate monohydrate), and other organic compounds and mineral products of the biological activity of the astrobiologically relevant model system C.
View Article and Find Full Text PDFThe existence of microbial activity hotspots in temperate regions of Earth is driven by soil heterogeneities, especially the temporal and spatial availability of nutrients. Here we investigate whether microbial activity hotspots also exist in lithic microhabitats in one of the most arid regions of the world, the Atacama Desert in Chile. While previous studies evaluated the total DNA fraction to elucidate the microbial communities, we here for the first time use a DNA separation approach on lithic microhabitats, together with metagenomics and other analysis methods (i.
View Article and Find Full Text PDFBackground: Subtraction CT angiography (sCTA) is a technique used to evaluate pulmonary perfusion based on iodine distribution maps. The aim of this study is to assess lung perfusion changes with sCTA seen in patients with COVID-19 pneumonia and correlate them with clinical outcomes.
Material And Methods: A prospective cohort study was carried out with 45 RT-PCR-confirmed COVID-19 patients that required hospitalization at three different hospitals, between April and May 2020.
Digital Health is one of the three pillars for the effective implementation of Universal Health Coverage in Argentina. The Ministry of Health published the National Digital Health Strategy 2018-2024 in order to establish the conceptual guidelines for the design and development of interoperable health information systems as a state policy. The World Health Organization "National eHealth Strategy Toolkit", "Global Strategy on Digital Health" and other international and local evidence and expert recommendations were taken into account.
View Article and Find Full Text PDFCarotenoids are promising targets in our quest to search for life on Mars due to their biogenic origin and easy detection by Raman spectroscopy, especially with a 532 nm excitation thanks to resonance effects. Ionizing radiations reaching the surface and subsurface of Mars are however detrimental for the long-term preservation of biomolecules. We show here that desiccation can protect carotenoid Raman signatures in the desert cyanobacterium sp.
View Article and Find Full Text PDFLong-term monitoring of organic pollutants in the soil is a major environmental challenge. We propose to meet this issue by the development of a polymer dedicated to selectively react with HS, coating surface acoustic wave transducers designed as passive cooperative targets with the compound, and probing their response using Ground Penetrating RADAR, thus providing the capability to monitor the presence of HS in the subsurface environment. The selectivity is brought by including lead(II) cation in a reticulated polymer matrix which can be deposited as a thin layer on a surface acoustic wave sensor.
View Article and Find Full Text PDFBackground: Rare diseases are defined by a prevalence of less than one out of 2000 persons. In clinical practice, their management is difficult, due to their diversity, their complexity and a lack of adapted physician training.
Objective: The aims of this study were to identify rare skin diseases in a reference center, to describe the difficulties encountered by general practitioners (GPs) in management of these uncommon cases, and to pinpoint the characteristics of the GPs having the most problems.