Lutetium half-life

The last of the lanthanides, this metal is also the hardest and the densest of them. It is a component of cerium mischmetal. Lutetium has some applications in optoelectronics. Shows great similarities to ytterbium. Its discoverer, Georges Urbain, carried out 15 000 fractional crystallizations to isolate pure lutetium (record ). The element has special catalytic properties (oil industry). 176Lu is generated artificially and is a good beta emitter (research purposes). 177Lu has a half-life of six days and is used in nuclear medicine. 

ISOTOPES There are a total of 59 isotopes of Lutetium. Only two of these are stable Lu-175, which makes up 97.41% of all the natural abundance found on Earth. The other is a long-lived radioisotope (Lu-176) with such a long half-life (4.00x10+ ° years) that it is considered stable Lu-176 contributes 2.59% to the natural abundance of lutetium. 

Lutetium-177 is increasingly being viewed as a potential radionuclide for use in in vivo therapy because of its favourable decay characteristics. Lutetium-177 decays with a half-life of 6.73 d by emission of beta particles with maximum energies of 497 keV (78.6%), 384 keV (9.1%) and 176 keV (12.2%) to stable Hf. The emission of gamma photons of 113 keV (6.4%) and 208 keV (11%) with relatively low abundances provides advantages that allow simultaneous... 

The emitted gamma photons produced by positron-electron annihilation can be detected using scintillation crystal detectors such as sodiiun iodide (Nal), bismuth germaniiun oxide (BGO) and cerium doped lutetium oxyorthosili-cate (LSO). The short half-life of most positron emitters leads to high specific activity. Only a very small quantity of radio-labeled molecules is thus required, making positron annihilation detection techniques very non-invasive. In fact, practical catalyst studies can be carried out using less than 37 kBq... 

Natural lutetium consists of two isotopes Lu and Lu (Tables 3.11 and 3.12). The latter is actually radioactive, but has an extremely long half-life of 3.78 x 10 years. In total, 34 radioisotopes have been identified, of which, besides Lu, the... 

Lutetium-176 is radioactive and subject to branched decay by P emission, mostly to Hf, though approximately 3 1% decays to Yb. However, the latter can be disregarded because of the long half-life of Lu. Thus, the decay scheme of interest is... 

Two approaches were used to determine the half-life of lutetium-176. These were analysis of lutetium-bearing minerals with known ages and direct counting. Variable results range from 2 to 7 X 10 ° years and a calculation from the slope of a Lu/Hf isochron formed by ten achondrites (eucrites) with an age of 4.55 x 10 years gave a value of (3.53 0.14) x 10 years. This value accords with a recent estimate of 3.8 x 10 years. 

Zirconium. The long half life (78.4 h) of Zr, a positron emitter, is of particular interest to immuno-PET since it can enable the longer reaction times required for radioimmunodiagnostic applications and has been explored for its potential to act as a theranostic pair with and Lu. In 2005 van Dongen et al. chelated Zr to cetuximab via succinylated desferrioxamine B (A-sucDf) with p-benzyl isothiocyanate-l,4,7,10-tetra-azacyclododecane-l,4,7,10-tetraacetic acid (p-SCN-Bz-DOTA) and p-iso-thiocyanatobenzyl diethylenetriaminepentaacetic acid (p-SCN-Bz-DTPA) for comparisons with Lu and (was used in the place of Y). The data showed that the zirconium complexes could accurately predict the lutetium and yttrium biodistribution. Subsequently, van Dongen et al. 

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