Abiotic formation of RNA was important for the emergence of terrestrial life, but the acknowledged difficulties of generating and stabilizing ribose have often raised questions regarding how the first RNA might have formed. Previous researchers have proposed that borate could have stabilized ribose; however, the availability of borate on the early Earth has been the subject of intense debate. In order to examine whether borate was available on the early Earth, this study examined metasedimentary rocks from the Isua Supracrustal Belt. Garnet, biotite, and quartz comprise the major constituents of the examined rocks. Field relationships and the chemical compositions of the examined rocks suggest sedimentary origin. The present study found that garnet crystals contain a number of inclusions of tourmaline (a type of borosilicate mineral). All tourmaline crystals are Fe-rich and categorized as schorl. Both garnet and tourmaline often contain graphite inclusions and this close association of tourmaline with garnet and graphite has not been recognized previously. Garnet-biotite and graphite geothermometers suggest that the tourmaline in garnet experienced peak metamorphic conditions (~500 °C and 5 kbar). The mineralogical characteristics of the tourmaline and the whole rock composition indicate that the tourmaline formed authigenically in the sediment during diagenesis and/or early metamorphism. Clay minerals in modern sediments have the capability to adsorb and concentrate borate, which could lead to boron enrichment during diagenesis, followed by tourmaline formation under metamorphic conditions. Clay minerals, deposited on the early Archean seafloor, were the precursors of the garnet and biotite in the examined samples. The studied tourmaline crystals were most likely formed in the same way as modern tourmaline in marine sediments. Therefore, boron enrichment by clays must have been possible even during the early Archean. Thus, similar enrichment could have been possible during the Hadean, providing a stabilization agent for ribose.
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http://dx.doi.org/10.1007/s11084-015-9474-x | DOI Listing |
Commun Biol
January 2025
Institute for Stroke and Dementia Research (ISD), LMU University Hospital, LMU Munich, Munich, Germany.
Circulating cytokines orchestrate immune reactions and are promising drug targets for immune-mediated and inflammatory diseases. Exploring the genetic architecture of circulating cytokine levels could yield key insights into causal mediators of human disease. Here, we performed genome-wide association studies (GWAS) for 40 circulating cytokines in meta-analyses of 74,783 individuals.
View Article and Find Full Text PDFSmall
December 2024
Fiber and Particle Engineering Research Unit, Faculty of Technology, University of Oulu, P.O. Box 4300, Oulu, 90014, Finland.
Here, hybrid stimuli-responsive (exhibiting pyroelectricity and piezoelectricity) porous cryogels are engineered by embedding tourmaline nanoparticles (TNs) in a cellulose nanofiber (CNF) skeleton to generate high-performance CNF-TN-based airborne particulate matter (PM) filters. First, single-layer hybrid cryogels with varying TN contents (0-5% w v) are assembled, and the design principles for multilayered filters are established based on a novel sequential pre-freezing and freeze-drying technique. As observed, the embedded TNs transformed the CNF network into a more homogeneous, isotropic, and firm structure, thus improving the structural integrity and thermal stability of the assembled cryogels while maintaining their ultrahigh porosity and low density.
View Article and Find Full Text PDFInt J Cardiol
February 2025
Brigham and Women's Hospital Heart and Vascular Center, Boston, MA, USA; Baim Institute for Clinical Research, Boston, MA, USA. Electronic address:
Background: Patients with a history of coronary revascularization are at a higher risk for subsequent cardiovascular events and all-cause mortality. Lowering LDL-cholesterol (LDL-C) levels post-revascularization significantly reduces these risks.
Methods: This analysis compared LDL-C-lowering therapies at baseline and over time among patients with and without prior coronary revascularization in the GOULD registry (a prospective multicenter cohort study).
Ophthalmic Plast Reconstr Surg
December 2024
Department of Oculofacial Plastic Surgery, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida.
Purpose: To compare regression rates, characteristics, and surgical outcomes of thyroid eye disease patients who underwent orbit, strabismus, or eyelid surgery at various times during or after teprotumumab treatment.
Design: Multicenter, retrospective, observational cohort study.
Participants: Adult patients (age >18) with a minimum of 4 infusions of teprotumumab treatment for thyroid eye disease who had had eye surgery during or after treatment.
Bioresour Technol
December 2024
School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China; Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control, Shenzhen 518055, China; State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China; Joint Laboratory of Urban High Strength Wastewater Treatment and Resource Utilization, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China. Electronic address:
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