Results 61 to 70 of about 5,445,983 (296)

The 17O/18O Ratio of Post-AGB Sources: Canonical and Non-Canonical Populations

open access: yesGalaxies
Stellar evolution models serve as tools to derive stellar parameters from elemental and isotopic abundance ratios. For low-to-intermediate mass evolved stars, C/O, 12C/13C, and 17O/18O ratios are proxies of the initial mass, a largely unknown parameter ...
Javier Alcolea   +9 more
doaj   +1 more source

Bernhardt-2018-abundances-time-series

open access: yes, 2018
Time series of population abundances in experimental populations of Tetraselmis tetrahele grown over a temperature ...
Bernhardt, Joey R   +5 more
core   +1 more source

Microbiome‐blood–brain barrier interactions in aging — mechanisms and therapeutic potential

open access: yesFEBS Letters, EarlyView.
Aging reshapes the gut microbiome (↓SCFA‐producing commensals; ↑pro‐inflammatory outputs), shifting circulating metabolites (↓SCFAs; ↑LPS, ↑TMAO, ↑PAA) that act at the BBB to increase nonspecific transcytosis, alter transport, and promote astrocyte reactivity, heightening brain vulnerability.
Daniel Cuervo‐Zanatta   +3 more
wiley   +1 more source

A Systematic NLTE Study of Very Metal-poor Stars with Metallicity down to −4.3 dex. VI. Light Neutron-capture Elements and the Sr–Na Correlation as a Signature of Spinstar Nucleosynthesis in the Early Galaxy

open access: yesThe Astrophysical Journal
We present a non–local thermodynamic equilibrium (NLTE) abundance analysis of the light neutron-capture elements Sr, Y, and Zr in a sample of 103 very metal-poor stars spanning −4.3 ≲ [Fe/H] ≲ −1.7, based on high-resolution Subaru/HDS spectra and ...
Sofya Alexeeva   +13 more
doaj   +1 more source

Optical Spectroscopy and Photoionization Model of Planetary Nebula NGC 6572

open access: yesJournal of Mathematical and Fundamental Sciences
We investigated NGC 6572 through optical spectroscopy to determine its kinematical and chemical properties. Two intermediate dispersion spectra (R~5000) centered around Hα and Hβ were used to derive the nebular expansion velocity from emission lines ...
Muhammad Fajrin   +2 more
doaj   +1 more source

The nature of long-GRB host galaxies from chemical abundances

open access: yes, 2010
Context. Gamma-ray bursts (GRBs) were the most energetic events after the Big Bang and they have been observed up to very high redshift. Measurements of the chemical abundances are now available for the galaxies hosting such events, which are assumed to ...
X. L. Fan   +5 more
core   +1 more source

An epithelial GPR35 isoform supports tumor‐associated transcriptional and metabolic phenotypes

open access: yesFEBS Letters, EarlyView.
GPR35 generates two functionally distinct isoforms with previously unresolved roles. GPR35‐short mediates immune‐cell chemotaxis, while GPR35‐long is enriched in colorectal cancer epithelium, where it supports increased metabolism, proliferation, and tumor‐associated transcriptional programs.
Jørgen D. Rønneberg   +14 more
wiley   +1 more source

Chemical Cartography with APOGEE: Two-process Parameters and Residual Abundances for 288,789 Stars from Data Release 17

open access: yesThe Astrophysical Journal
Stellar abundance measurements are subject to systematic errors that induce extra scatter and artificial correlations in elemental abundance patterns. We derive empirical calibration offsets to remove systematic trends with surface gravity $\mathrm{log ...
Tawny Sit   +6 more
doaj   +1 more source

Core to Cosmic Edge: SIMBA-C’s New Take on Abundance Profiles in the Intragroup Medium at z = 0

open access: yesUniverse
We employ the simba-c cosmological simulation to study the impact of its upgraded chemical enrichment model (Chem5) on the distribution of metals in the intragroup medium (IGrM).
Aviv Padawer-Blatt   +11 more
doaj   +1 more source

Analysis of chemical abundances in planetary nebulae with [WC] central stars [PDF]

open access: yesAstronomy & Astrophysics, 2013
Accepted for publication in A&A. 15 Tables and 18 Figures.
García Rojas, Jorge   +5 more
openaire   +3 more sources

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