Results 41 to 50 of about 85,610 (304)

An Idea to Explore: From How to Why: Using Evolutionary Biochemistry to Inspire Biochemistry Education

open access: yesBiochemistry and Molecular Biology Education, EarlyView.
ABSTRACT Traditional biochemistry instruction often emphasizes mechanistic detail, that is, how molecules and pathways function, without equally addressing why they have their present forms. This fact‐centered approach can leave students overwhelmed and disconnected from the broader scientific narrative.
Alberto Vázquez‐Salazar
wiley   +1 more source

Extraterrestrial hexamethylenetetramine in meteorites—a precursor of prebiotic chemistry in the inner solar system

open access: yesNature Communications, 2020
This manuscript tackles the origin of organic molecules in carbonaceous meteorites. Identifying hexamethylenetetramine in three carbonaceous meteorites, the authors propose formation from ammonia and formaldehyde by photochemical and thermal reactions in
Yasuhiro Oba   +6 more
doaj   +1 more source

Shock-Induced Degradation of Guanosine and Uridine Promoted by Nickel and Carbonate: Potential Applications

open access: yesMolecules, 2023
Experimental studies of the degradation of two ribonucleosides (guanosine and uridine) were carried out by making use of mechanochemistry. Mechanochemical experiments reveal the decomposition of guanosine and uridine, promoted by nickel(II) and carbonate
Gustavo P. Maia   +3 more
doaj   +1 more source

Previously unknown class of metalorganic compounds revealed in meteorites

open access: yesProceedings of the National Academy of Sciences of the United States of America, 2017
Significance In this study we report the discovery of a previously unrecognized chemical class, dihydroxymagnesium carboxylates, [(HO)2MgO2CR]−, gained from nonterrestrial meteoritic analyses.
A. Ruf   +21 more
semanticscholar   +1 more source

Charge State Influence on Stability and Isomerism in Dehydrogenated PAHs: Insights from Anthracene, Acridine, and Phenazine

open access: yesChemPhysChem, Volume 26, Issue 6, March 15, 2025.
The ionization of anthracene, acridine, and phenazine has been explored, along with the removal of one and two hydrogen atoms, to provide valuable information for astrochemists and to understand the behavior of the resulting structures and their electronic reorganization. Abstract In this study, we systematically explored the stability and isomerism of
Khaldia Zghida   +3 more
wiley   +1 more source

Molybdenum isotopic evidence for the origin of chondrules and a distinct genetic heritage of carbonaceous and non-carbonaceous meteorites

open access: yes, 2016
Nucleosynthetic isotope anomalies are powerful tracers to determine the provenance of meteorites and their components, and to identify genetic links between these materials. Here we show that chondrules and matrix separated from the Allende CV3 chondrite
G. Budde   +5 more
semanticscholar   +1 more source

Analytical Characterization of Quantum Dot Enhancement Films in Commercial Displays

open access: yesHelvetica Chimica Acta, EarlyView.
Colloidal quantum dots (QDs) are increasingly used in displays, yet many compositions are regulated due to hazardous metal content. Their accurate identification and assessment are therefore essential. Here, a multimodal analytical workflow centered on LA‐ICP‐MS enables spatially resolved identification and classification of QDs in commercial quantum ...
Dylan Käser   +10 more
wiley   +1 more source

Study of Iron and Stony Meteorite Ablation Based on Simulation Experiments in an Arc Heater

open access: yesThe Astrophysical Journal
To observe meteorite ablation, simulation experiments were conducted on the L5 ordinary chondrite and IAB-MG iron meteorites in an arc-heated facility and three flight conditions were reproduced.
Lei Wang   +7 more
doaj   +1 more source

Evolution of water reservoirs on Mars: Constraints from hydrogen isotopes in martian meteorites [PDF]

open access: yes, 2014
Martian surface morphology implies that Mars was once warm enough to maintain persistent liquid water on its surface. While the high D/H ratios (∼6 times the Earth's ocean water) of the current martian atmosphere suggest that significant water has been ...
H. Kurokawa   +6 more
semanticscholar   +1 more source

A Nonlinear Quantitative Model for Measuring Concentration Ratios From Raman Intensities

open access: yesJournal of Raman Spectroscopy, EarlyView.
Estimating concentration from Raman intensity ratios is complicated by cross‐contributions from overlapping peaks, causing measured ratios to deviate from the linear behavior assumed in conventional quantitative models. This nonlinear method fully accounts for cross‐contributions, allowing estimation of concentration over several orders of magnitude ...
Joseph Razzell Hollis
wiley   +1 more source

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