Results 21 to 30 of about 67,280 (303)

Short-lived Nuclei in the Early Solar System: Possible AGB Sources [PDF]

open access: yes, 2005
(Abridged) We review abundances of short-lived nuclides in the early solar system (ESS) and the methods used to determine them. We compare them to the inventory for a uniform galactic production model.
Abia   +288 more
core   +3 more sources

Carbon-rich presolar grains from massive stars : subsolar ¹²C/¹³C and ¹⁴N/¹⁵N ratios and the mystery of ¹⁵N [PDF]

open access: yes, 2015
Carbon-rich grains with isotopic anomalies compared to the Sun are found in primitive meteorites. They were made by stars, and carry the original stellar nucleosynthesis signature.
Fryer, C.   +9 more
core   +3 more sources

Aproveitamento de nitrogênio pelo milho, em razão da adubação verde, nitrogenada e fosfatada Nitrogen utilization by corn as affected by green manures and nitrogen and phosphorus fertilizers

open access: yesPesquisa Agropecuária Brasileira, 2009
O objetivo deste trabalho foi avaliar o aproveitamento, pelo milho (Zea mays L.), do nitrogênio (N) proveniente da ureia, de restos culturais da crotalária (Crotalaria juncea) e do milheto (Pennisetum glaucum), e do solo, em função da adubação ...
Edson Cabral da Silva   +3 more
doaj   +1 more source

Antagonistic Interaction of Selenium and Cadmium in Human Hepatic Cells Through Selenoproteins

open access: yesFrontiers in Chemistry, 2022
Cadmium (Cd) is a highly toxic heavy metal for humans and animals, which is associated with acute hepatotoxicity. Selenium (Se) confers protection against Cd-induced toxicity in cells, diminishing the levels of ROS and increasing the activity of ...
S. Ramírez-Acosta   +4 more
doaj   +1 more source

On the Origin of the Early Solar System Radioactivities. Problems with the AGB and Massive Star Scenarios [PDF]

open access: yes, 2018
Recent improvements in stellar models for intermediate-mass and massive stars are recalled, together with their expectations for the synthesis of radioactive nuclei of lifetime $\tau \lesssim 25$ Myr, in order to re-examine the origins of now extinct ...
Busso, M.   +9 more
core   +2 more sources

Timing carbon turnover (δ13C) in weaned piglet’s brain by IRMS

open access: yesAnais da Academia Brasileira de Ciências, 2018
Isotope-ratio mass spectrometry (IRMS) is a potential tool that provides time-integrated estimate of assimilated and not just ingested nutrients. This feature turned possible its application to evaluate the effects of dietary nucleotides and glutamate on
MAYRA A.D. SALEH   +5 more
doaj   +1 more source

The temperature and chronology of heavy-element synthesis in low-mass stars [PDF]

open access: yes, 2015
Roughly half of the heavy elements (atomic mass greater than that of iron) are believed to be synthesized in the late evolutionary stages of stars with masses between 0.8 and 8 solar masses. Deep inside the star, nuclei (mainly iron) capture neutrons and
A Jorissen   +39 more
core   +1 more source

Incorporation of Labeled Methionine as a Tissue Tracer in Broiler Chickens

open access: yesBrazilian Journal of Poultry Science
The objective of this study was to evaluate the process of L-methionine incorporation in the blood plasma, liver, breast muscle, and abdominal fat of 35- to 59-d-old broiler chickens using the carbon stable isotope (12C and 13C) technique for the ...
AC Stradiotti   +7 more
doaj   +1 more source

The Potential of Isotopic Tracers for Precise and Environmentally Clean Stream Discharge Measurements

open access: yesHydrology, 2023
Accurate discharge measurement is mandatory for any hydrological study. While the “velocity” measurement method is adapted to laminar flows, the “dilution” method is more appropriate for turbulent streams.
Antoine Picard   +8 more
doaj   +1 more source

Diagnóstico da deficiência de fósforo em ovinos pela técnica de incorporação de fósforo radioativo nos eritrócitos Phosphorus deficiency diagnosis in sheep using labeled phosphorus uptake by erythrocytes

open access: yesPesquisa Agropecuária Brasileira, 2006
Este trabalho teve como objetivo avaliar a técnica de incorporação de 32P pelos eritrócitos de ovinos jovens, mantidos em pastejo de Andropogon gayanus, como método de diagnóstico da deficiência de fósforo.
Dalton Araujo Antunes   +7 more
doaj   +1 more source

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