AI Article Synopsis
Article Abstract
Recent high precision (142)Nd isotope measurements showed that global silicate differentiation may have occurred as early as 30-75 Myr after the Solar System formation [Bennett V, et al. (2007) Science 318:1907-1910]. This time scale is almost contemporaneous with Earth's core formation at approximately 30 Myr [Yin Q, et al. (2002) Nature 418:949-952]. The (182)Hf-(182)W system provides a powerful complement to the (142)Nd results for early silicate differentiation, because both core formation and silicate differentiation fractionate Hf from W. Here we show that eleven terrestrial samples from diverse tectonic settings, including five early Archean samples from Isua, Greenland, of which three have been previously shown with (142)Nd anomalies, all have a homogeneous W isotopic composition, which is approximately 2epsilon-unit more radiogenic than the chondritic value. By using a 3-stage model calculation that describes the isotopic evolution in chondritic reservoir and core segregation, as well as silicate differentiation, we show that the W isotopic composition of terrestrial samples provides the most stringent time constraint for early core formation (27.5-38 Myr) followed by early terrestrial silicate differentiation (38-75 Myr) that is consistent with the terrestrial (142)Nd anomalies.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2890712 | PMC |
| http://dx.doi.org/10.1073/pnas.0913605107 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Silicate-substituted bovine-derived hydroxyapatite as a bone substitute in regenerative dentistry.
J Appl Biomater Funct Mater
January 2025
Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.
Hydroxyapatite, renowned for its biocompatibility and osteoconductive properties, plays a fundamental role in bone regeneration owing to its resemblance to natural bone mineral, thus offering considerable potential for advancing tissue engineering strategies. In this article, the innovative integration of silicon ions into biogenic (bovine-derived) hydroxyapatite (SiBHA) via a tailored sol-gel process is reported. The resultant SiBHA scaffolds exhibited an interconnected microporous structure with a total porosity of 70% and pore dimensions ranging from 120 to 650 µm.
View Article and Find Full Text PDFNon-invasive in vitro NAM for the detection of reversible and irreversible eye damage after chemical exposure for GHS classification purposes (ImAi).
Arch Toxicol
January 2025
Translational Center Regenerative Therapies (TLC-RT), Fraunhofer Institute for Silicate Research (ISC), Röntgenring 12, 97070, Würzburg, Germany.
The potential risk of chemicals to the human eye is assessed by adopted test guidelines (TGs) for regulatory purposes to ensure consumer safety. Over the past decade, the Organization for Economic Co-operation and Development (OECD) has approved new approach methodologies (NAMs) to predict chemical eye damage. However, existing NAMs remain associated with limitations: First, no full replacement of the in vivo Draize eye test due to limited predictability of severe/mild damage was reached.
View Article and Find Full Text PDFThe initial solar system abundance of Fe and early core formation of the first asteroids.
Sci Adv
January 2025
Université de Lorraine, CNRS, CRPG, UMR7358, F-54000 Nancy, France.
High-precision Ni isotope analyses of the differentiated andesitic meteorite Erg Chech 002 (EC 002), the oldest known crustal fragment of a planetesimal, show that short-lived Fe was present in the early solar system with an initial Fe/Fe ratio of (7.71 ± 0.47) × 10, which is five times more precise than previous estimates and is proposed to be the reference value for further studies.
View Article and Find Full Text PDFLithium-doped calcium silicate cement regulates the immune microenvironment and promotes M2 macrophage polarization for enhancing bone regeneration.
J Biol Eng
January 2025
Department of Biomedical Engineering, China Medical University, Taichung, 406040, Taiwan.
Bone defects present a significant challenge in orthopedics and trauma surgery, necessitating innovative approaches to stimulate effective bone regeneration. This study investigated the potential of lithium-doped calcium silicate (LiCS) cement to enhance bone regeneration and modulate the immune microenvironment to promote tissue repair. We synthesized a LiCS ceramic powder and performed comprehensive analyses of its physicochemical properties, including phase composition, morphology, setting time, and mechanical strength.
View Article and Find Full Text PDFDecellularized cartilage tissue bioink formulation for osteochondral graft development.
Biomed Mater
January 2025
Department of Biomedical Engineering, University of Connecticut, Storrs, CT 06269, United States of America.
Articular cartilage and osteochondral defect repair and regeneration presents significant challenges to the field of tissue engineering (TE). TE and regenerative medicine strategies utilizing natural and synthetic-based engineered scaffolds have shown potential for repair, however, they face limitations in replicating the intricate native microenvironment and structure to achieve optimal regenerative capacity and functional recovery. Herein, we report the development of a cartilage extracellular matrix (ECM) as a printable biomaterial for tissue regeneration.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!