Practical Applications of Radioactivity and Nuclear Radiations

Lowenthal, Gerhart; Airey, Peter

doi:10.1017/cbo9780511535376

Cited by 31 publications

(17 citation statements)

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“…To measure the absorption in a shield material, narrow beam method (Lowenthal and Airey, 2001) was used, where slices of the studied material were stacked in different numbers above a lead collimator placed on the cap of the detector, Fig. 1.…”

Section: Methodsmentioning

confidence: 99%

Experimental investigation of γ-ray attenuation in Jordanian building materials using HPGe-spectrometer

Awadallah

Imran

2007

Journal of Environmental Radioactivity

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Section: Methodsmentioning

confidence: 99%

Experimental investigation of γ-ray attenuation in Jordanian building materials using HPGe-spectrometer

Awadallah

Imran

2007

Journal of Environmental Radioactivity

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“…Considering that the half-life of 64 Cu is 12.7 h, we used a completely decayed solution of 64 CuCl 2 in water (> 12 half-lives), which ensured that the solution contained 61% 64 Ni 2+ and 39% 64 Zn 2+ in addition to any other incipient metals5. The remaining amount of 64 Cu 2+ was virtually zero.…”

mentioning

confidence: 99%

Radioactivity-Synchronized Fluorescence Enhancement Using a Radionuclide Fluorescence-Quenched Dye

et al. 2009

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Metal-sensitive fluorescent probes have been shown to accurately and rapidly report metal complexation through a change in the fluorophore's spectral properties [1][2][3] . Previous studies have focused on quasi-static metal-fluorophore complexes, where a single metal of interest complexes with the fluorophore, altering its emission in some discernable fashion. The resultant emission could be further modified by changing the ligands attached to metals or altering the metal oxidation states. Neither experimental nor theoretical studies have been conducted regarding dynamic metal-fluorophore complexes in which the nature of the bound metal itself is variable. Such changes, for example, may transform a non-fluorescent complex into a fluorescent system if a quencher metal could convert into a non-quencher metal. The difficulty in achieving this transformation arises from the high stability of metals. However, a select group of metals such as radionuclides, is ideally suited for this application because spontaneous radioactivity decay of an unstable parent metal could transform it to a different, more stable metal.Herein we propose the first molecular system that demonstrates the feasibility of altering the fluorescence properties of an organic dye as a function of radionuclide decay. Previous studies have shown that 64 Cu decays to 64 Zn and 64 Ni through two pathways, as shown in the following equation:We found a clear differentiation in fluorescence between Cu 2+ and its decay products, with Cu 2+ acting as a strong quencher, Zn 2+ as an enhancer, and Ni 2+ having no net effect on the dye fluorescence. Correlation of the radionuclide decay with the dye fluorescence enhancement validates the hypothesized metal effect and suggests a realm of possible applications for complementing fluorescence with radioactivity. To study the influence of inter-metal conversion through radioactive decay on the fluorescence properties of organic dyes, we prepared LS479, a novel near-infrared fluorescent dye with a covalently linked metal chelating group (Scheme 1). LS479 is structurally similar to a known dye 1,1′,3,3,3′,3′-hexamethylindotricarbocyanine (HITC), which is widely used in analytical chemistry and biological optical imaging studies 4 . The chelating group is derived from diethylenetriamine pentaacetic acid (DTPA). The synthesis of LS479 (Scheme 1) involves the methylation of 5-nitro-2,3,3-trimethylindolenine to provide the indole analog 2 in a 60% yield. Reduction of the nitro group, followed by N-alkylation using N,N-bis [(tert-butyloxycarbonyl) methyl]-2-bromoethylamine 1 afforded the indole derivative 4 in an overall yield of 65%. Treatment of 1,2,3,3-tetramethylindolinium iodide with glutacondialdehyde dianil, acetyl chloride, and acetic anhydride produced the hemicyanine intermediate 5 in an 87% yield. Reaction of 5 with the indole derivative 4 under reflux in anhydrous ethanol with anhydrous sodium acetate afforded Boc-protected intermediate 6, which was isolated in good yield (74.5%). The hydrolysis of 6 to affor...

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“…Compare this to the International Commission on Radiological Protection's annual dose limit of x-ray shoe fitter 100-1,160 500 mSv to the feet for radiation workers. 7 Table I 8 shows a comparison of exposures. It is sobering to consider that at the lower limit, the x-ray shoe fitters gave exposures similar to 1,000 modern dental x-rays and at the upper limit, something like 1,400 hip xrays.…”

Section: Radiation Exposurementioning

confidence: 99%