Results 1 to 10 of about 1,283,979 (117)

Modelling the chemical evolution [PDF]

Proceedings of the International Astronomical Union, 2010
Advanced observational facilities allow to trace back the chemical evolution of the Universe, on the one hand, from local objects of different ages and, secondly, by direct observations of redshifted objects.
Argast, Cescutti, Chiappini, Colavitti, Gerhard Hensler, Harfst, Hensler, Hensler, Hensler, Hensler, Hirschi, Ikuta, Koch, Koeppen, Koeppen, Kroeger, Maciel, Maeder, Matteucci, Meynet, Meynet, Meynet, Momany, Nordstroem, Pagel, Pagel, Portinari, Portinari, Prantzos, Prantzos, Recchi, Recchi, Recchi, Recchi, Revaz, Samland, Schaller, Simone Recchi, Spitoni, Theis, Tinsley   +40 more
core   +3 more sources

Chemical Evolution in VeLLOs [PDF]

Journal of The Korean Astronomical Society, 2007
A new type of object called "Very Low Luminosity Objects (VeLLOs)" has been discovered by the Spitzer Space Telescope. VeLLOs might be substellar objects forming by accretion.
Lee, Jeong-Eun
core   +4 more sources

Cosmic Chemical Evolution [PDF]

The Astrophysical Journal, 1999
Numerical simulations of standard cosmological scenarios have now reached the degree of sophistication required to provide tentative answers to the fundamental question: Where and when were the heavy elements formed? Averaging globally, these simulations
Dave R., Jeremiah P. Ostriker, Renyue Cen, Tamura T., Tripp T. M.   +4 more
core   +4 more sources

Differential Oligomerization of Alpha versus Beta Amino Acids and Hydroxy Acids in Abiotic Proto-Peptide Synthesis Reactions

Life, 2022
The origin of biopolymers is a central question in origins of life research. In extant life, proteins are coded linear polymers made of a fixed set of twenty alpha-L-amino acids.
Moran Frenkel-Pinter, Kaitlin C. Jacobson, Jonathan Eskew-Martin, Jay G. Forsythe, Martha A. Grover, Loren Dean Williams, Nicholas V. Hud   +6 more
doaj   +1 more source

Thioesters provide a plausible prebiotic path to proto-peptides

Nature Communications, 2022
One of the early processes enabling the origins of life is thought to be the condensation of building blocks into oligomers and polymers. In this article, the authors report the synthesis of thiodepsipeptides and HS-peptides under mild temperatures and ...
Moran Frenkel-Pinter, Marcos Bouza, Facundo M. Fernández, Luke J. Leman, Loren Dean Williams, Nicholas V. Hud, Aikomari Guzman-Martinez   +6 more
doaj   +1 more source

Stability of DL-Glyceraldehyde under Simulated Hydrothermal Conditions: Synthesis of Sugar-like Compounds in an Iron(III)-Oxide-Hydroxide-Rich Environment under Acidic Conditions

Life, 2022
Researchers have suggested that the condensation of low-molecular-weight aldehydes under basic conditions (e.g., pH > 11) is the prebiotic reaction responsible for the abiotic formation of carbohydrates.
Claudio Alejandro Fuentes-Carreón, Jorge Armando Cruz-Castañeda, Eva Mateo-Martí, Alicia Negrón-Mendoza   +3 more
doaj   +1 more source

Geochemical evolution of saline formation water of the Mozduran gas reservoir [PDF]

Journal of Stratigraphy and Sedimentology Researches, 2018
The Mozduran gas reservoir in the Khangiran gas-field is formed in the Kopet-Dagh sedimentary basin in the form of sequential sequences of clastic and carbonate sediments of the old sea water.
mahdi miri, Rahim Bagheri, Mohammad Reza Akhlaghi, Farzad Sotohian   +3 more
doaj   +1 more source

Mutually stabilizing interactions between proto-peptides and RNA

Nature Communications, 2020
Cooperative relationships are widespread among different classes of biopolymers and are predicted to have existed during emergence of life. This study shows that proto-peptides engage in mutually stabilizing interactions with RNA, providing support for ...
Moran Frenkel-Pinter, Jay W. Haynes, Ahmad M. Mohyeldin, Martin C, Alyssa B. Sargon, Anton S. Petrov, Ramanarayanan Krishnamurthy, Nicholas V. Hud, Loren Dean Williams, Luke J. Leman   +9 more
doaj   +1 more source

A High-Pressure, High-Temperature Flow Reactor Simulating the Hadean Earth Environment, with Application to the Pressure Dependence of the Cleavage of Avocado Viroid Hammerhead Ribozyme

Life, 2022
The RNA world hypothesis suggests that chemical networks consisting of functional RNA molecules could have constructed a primitive life-like system leading a first living system.
Kunio Kawamura, Mari Ogawa, Noriko Konagaya, Yoshimi Maruoka, Jean-François Lambert, Louis M. P. Ter-Ovanessian, Jacques Vergne, Guy Hervé, Marie-Christine Maurel   +8 more
doaj   +1 more source

Reactions of Graphene Nano-Flakes in Materials Chemistry and Astrophysics

Physchem, 2022
The elucidation of the mechanism of the chemical evolution of the universe is one of the most important themes in astrophysics. Polycyclic aromatic hydrocarbons (PAHs) provide a two-dimensional reaction field in a three-dimensional interstellar space ...
Hiroto Tachikawa, Tetsuji Iyama
doaj   +1 more source