Oxygen-18 (18 O, Ω [1]) is a natural, stable isotope of oxygen and one of the environmental isotopes. 18 O is an important precursor for the production of fluorodeoxyglucose (FDG) used in positron emission tomography (PET). Generally, in the …

In geochemistry, paleoclimatology and paleoceanography δ18O or delta-O-18 is a measure of the deviation in ratio of stable isotopes oxygen-18 (18 O) and oxygen-16 (16 O).

It is called "light" because a small fraction of oxygen atoms have 2 extra neutrons and a resulting atomic weight of 18 (18 O), which is then known as "heavy" oxygen. 18 O is a rare form and is found in only about 1 in 500 atoms of oxygen.

Oxygen-18 is a stable isotope of the chemical element oxygen, which has 10 neutrons in its atomic nucleus in addition to the element-specific 8 protons; the sum of the number of these atomic nucleus building blocks results in a mass number of 18. According to a report from 1929, 18 O was identified as a distinct oxygen isotope based on the ...

2018年10月5日 · Global Seawater Oxygen-18 Database. This database is a collection of over 26,000 seawater O-18 values made since about 1950. We hope that other researchers can benefit from the not-inconsiderable pain it took to collect, …

Oxygen-18 in the water or gaseous form serves as a source for short-lived positron-emitting isotope fluorine-18, which allows tracking the processes of cerebral blood flow, glucose metabolism in the central nervous and cardiovascular systems, evaluating the impact of drugs on neuroreceptors. 18F is also used in brain imaging.

2020年6月1日 · Results showed microbes used less than 8.3% glucose-oxygen and more than 91.7% water-oxygen for their DNA synthesis. The 18 O-labelled water method for estimation of CUE has proven to be reliable under low enrichment of 18O in soil water.

In plant ecological physiology the stable oxygen isotope composition refers to the relative abundance of 18 O to 16 O. The oxygen isotope composition of leaf water is determined by the composition of plant water sources and leaf evaporative conditions.

2024年5月25日 · Oxygen-18 (O 18 or 18 O) is a stable isotope of oxygen that differs from the more common oxygen-16 due to the presence of two additional neutrons in its nucleus. Naturally occurring in the Earth’s atmosphere and hydrosphere, Oxygen-18 is a vital tracer used in many scientific applications, particularly in paleoclimatology to understand past ...

Oxygen 18 (18 O), an isotope of oxygen with atomic mass number 18 (8 protons + 10 neutrons) 2019 Catalan general strike (18-O) 18º, a way to write the ordinal number 18th (eighteenth)