Results 81 to 90 of about 8,849 (202)

Ratiometric glucose sensing based on fluorescent oxygen films and glucose oxidase

Sensing and Bio-Sensing Research, 2017
A new two-layer sensor film was constructed for sensing glucose based on glucose oxidase and oxygen sensing material. The first layer of film containing the oxygen sensor and intra-reference material was polymerized, then the second layer of glucose ...
Fengyu Su, Liqiang Zhang, Xiangxing Kong, Fred Lee, Yanqing Tian, Deirdre R. Meldrum   +5 more
doaj  

Detecting Biosignatures in Nearby Rocky Exoplanets Using High-contrast Imaging and Medium-resolution Spectroscopy with the Extremely Large Telescope

The Astronomical Journal, 2023
In the upcoming decades, one of the primary objectives in exoplanet science is to search for habitable planets and signs of extraterrestrial life in the Universe.
Huihao Zhang, Ji Wang, Michael K. Plummer   +2 more
doaj   +1 more source

Diagnostic biosignature transformation under simulated martian radiation in organic-rich sedimentary rocks

Frontiers in Astronomy and Space Sciences, 2022
As we look for traces of ancient life on Mars, we need to consider the impact of ionizing radiation in the biosignature preservation process. Here, we irradiated two organic rich terrestrial samples (Enspel and Messel shales) that have Martian analog ...
A. Roussel, A. C. McAdam, H. V. Graham, A. A. Pavlov, C. N. Achilles, C. N. Achilles, C. N. Achilles, C. A. Knudson, C. A. Knudson, C. A. Knudson, A. Steele, D. I. Foustoukos, S. S. Johnson, S. S. Johnson   +13 more
doaj   +1 more source

Cretaceous Chert‐Hosted Microfossils Visualized With Synchrotron Ptychographic X‐Ray Computed Tomography (PXCT)

Geobiology, Volume 23, Issue 3, May/June 2025.
ABSTRACT Silicification of microfossils is an important taphonomic process that provides a record of microbial life across a range of environments throughout Earth history. However, questions remain regarding the mechanism(s) by which silica precipitated and preserved delicate organic material and detailed cellular morphologies.
Kelsey R. Moore, Theodore M. Present, Antoine Crémière, Manuel Guizar‐Sicairos, Mirko Holler, Andrew Barnett, Kristin Bergmann, Joachim Amthor, John Grotzinger   +8 more
wiley   +1 more source

Biosignatures of Exposure/Transmission and Immunity [PDF]

The American Journal of Tropical Medicine and Hygiene, 2015
A blood test that captures cumulative exposure over time and assesses levels of naturally acquired immunity (NAI) would provide a critical tool to monitor the impact of interventions to reduce malaria transmission and broaden our understanding of how NAI develops around the world as a function of age and exposure. This article describes a collaborative
King, Christopher L, Davies, D Huw, Felgner, Phil, Baum, Elizabeth, Jain, Aarti, Randall, Arlo, Tetteh, Kevin, Drakeley, Christopher J, Greenhouse, Bryan   +8 more
openaire   +6 more sources

Ecosystem-bedrock interaction changes nutrient compartmentalization during early oxidative weathering

, 2019
Ecosystem-bedrock interactions power the biogeochemical cycles of Earth's shallow crust, supporting life, stimulating substrate transformation, and spurring evolutionary innovation.
Amistadi, Mary K., Burghelea, Carmen I., Castrejón-Martinez, Ricardo, Chorover, Jon, Domanik, Kenneth J., Dontsova, Katerina, Gaddis, Emily E., Galey, Miranda, Hunt, Edward A., Li, Kexin, Maier, Raina M., Munoz, Elise, Palacios-Menendez, Maria A., Presler, Jennifer K., Reinhard, Christopher T., Roldan-Nicolau, Estefania, Sandhaus, Shana, Vaquera-Ibarra, Maria O., Zaharescu, Dragos G.   +18 more
core   +1 more source

Raman Spectroscopic Analysis of Geological and Biogeological Specimens of Relevance to the ExoMars Mission [PDF]

, 2013
H.G.M.E., I.H., and R.I. acknowledge the support of the STFC Research Council in the UK ExoMars programme. J.J. and P.V. acknowledge the support of the Grant Agency of the Czech Republic (210/10/0467) and of the Ministry of Education of the Czech ...
Edwards H.G.M., Edwards H.G.M., Howell G.M. Edwards, Ian B. Hutchinson, Jan Jehlička, John Parnell, Lewis I.R., Petr Vítek, Richard Ingley, Rull F.   +9 more
core   +1 more source

Troubles With Tubules: How Do Iron‐Mineral Chemical Gardens Differ From Iron‐Mineralized Sheaths of Iron Oxidizing Bacteria?

Geobiology, Volume 23, Issue 3, May/June 2025.
ABSTRACT Microscopic tubules and filaments composed of iron minerals occur in various rock types of all ages. Although typically lacking carbonaceous matter, many are reasonably interpreted as the remains of filamentous microorganisms coated with crystalline iron oxyhydroxides. Iron‐oxidizing bacteria (IOB) acquire such a coating naturally during life.
Melanie Podbielski, Pamela Knoll, Georgia Brown, Sigrid Huld, Anna Neubeck, Julyan H. E. Cartwright, C. Ignacio Sainz‐Díaz, Carlos Pimentel, Sean McMahon   +8 more
wiley   +1 more source

Evaluating Biogenicity on the Geological Record With Synchrotron-Based Techniques

Frontiers in Microbiology, 2019
The biogenicity problem of geological materials is one of the most challenging ones in the field of paleo and astrobiology. As one goes deeper in time, the traces of life become feeble and ambiguous, blending with the surrounding geology.
Flavia Callefo, Lara Maldanis, Lara Maldanis, Verônica C. Teixeira, Rodrigo Adrián de Oliveira Abans, Rodrigo Adrián de Oliveira Abans, Thiago Monfredini, Fabio Rodrigues, Douglas Galante   +8 more
doaj   +1 more source

Production of carbon-containing pyrite spherules induced by hyperthermophilic Thermococcales: a biosignature?

Frontiers in Microbiology, 2023
Thermococcales, a major order of hyperthermophilic archaea inhabiting iron- and sulfur-rich anaerobic parts of hydrothermal deep-sea vents, are known to induce the formation of iron phosphates, greigite (Fe3S4) and abundant quantities of pyrite (FeS2 ...
Chloé Truong, Sylvain Bernard, Pierre Le Pape, Guillaume Morin, Camille Baya, Pauline Merrot, Aurore Gorlas, François Guyot, François Guyot   +8 more
doaj   +1 more source