High resolution γ-spectrometry by HPGe detector and β-spectrometry by liquid scintillation counting, hyphenated to elemental analysis techniques: applications of high specific activity radio-nuclides for ultra-trace metallo-toxicological and environmental studies

2002 ◽  
Vol 73 (1-2) ◽  
pp. 203-211 ◽  
Author(s):  
Flavia Groppi ◽  
Claudio Birattari ◽  
Mauro Bonardi ◽  
Luigi Gini
Keyword(s):  
High Resolution ◽  
Elemental Analysis ◽  
Hpge Detector ◽  
Liquid Scintillation ◽  
Specific Activity ◽  
High Specific Activity ◽  
Scintillation Counting ◽  
Analysis Techniques ◽  
Γ Spectrometry ◽  
Ultra Trace

The permeability to cytochalasin B of the new unpigmented surface in the first cleavage furrow of the newt's egg

Development ◽  
1976 ◽  
Vol 36 (2) ◽  
pp. 321-341
Author(s):  
G. G. Selman ◽  
J. Jacob ◽  
M. M. Perry
Keyword(s):  
Osmium Tetroxide ◽  
Cytochalasin B ◽  
Specific Activity ◽  
High Specific Activity ◽  
Scintillation Counting ◽  
Cleavage Furrow ◽  
Limited Extent ◽  
Normal Medium ◽  
Cleavage Initiation ◽  
Whole Egg

Two to 10 µg/ml cytochalasin B (CB) caused retraction of the first cleavage furrow in Triturus eggs, a spreading of the unpigmented surface from the furrow region and a flattening of the whole egg. CB appears to act against the contractility of the microfilamentous band at mid-cleavage so as to relax the furrow and also to weaken unpigmented surface to allow the egg to flatten. Uncleaved eggs and the initial formation of the cleavage groove were unaffected by CB. A fully-retracted first cleavage furrow reformed itself on transfer of the egg to normal medium but only at the time of second cleavage. Initiation of second cleavage depended upon there being sufficient of the original pigmented surface on the animal hemisphere. Tritium-labelled CB of high specific activity was prepared and used to study its ability to penetrate the surface of newt eggs during cleavage. Scintillation counting of whole eggs showed that CB was not taken into the newt egg until mid-cleavage (about 17 min after the double stripe stage) when new surface began to spread in the cleavage furrow. Fixation in glutaraldehyde and osmium tetroxide retained radioactivity in the egg, but more CB was retained after fixation in osmium tetroxide alone than after double fixation. Most of the retained radioactivity was in yolk platelets. Autoradiographs were prepared of sectioned eggs whichad been fixed at late cleavage after [3H]CB had flattened the furrow. These showed that CBentered the egg through the unpigmented surface which formed in the furrow but it could not enter through the pigmented surface. The impermeability of the pigmented surface explains the observations that CB does not prevent initial furrowing at cleavage. Once inside the egg CB is transported slowly. CB penetrates to a limited extent beneath the pigmented surface from its border with the unpigmented surface in the first cleavage furrow and this seems insufficient in some circumstances to suppress the contractile phase of second cleavage.

Radioassay of Chromic Phosphate 32P Suspension by Cerenkov Counting

1975 ◽  
Vol 58 (5) ◽  
pp. 995-997
Author(s):  
Martin W Heitzman ◽  
Leonard A Ford
Keyword(s):  
Standard Deviation ◽  
Liquid Scintillation ◽  
Specific Activity ◽  
Scintillation Counter ◽  
High Specific Activity ◽  
Internal Standard ◽  
Standard Technique ◽  
Liquid Scintillation Counter ◽  
Cerenkov Counting ◽  
Precise Method

Abstract A simple and precise method is presented for the radioassay of chromic phosphate 32P suspension by Cerenkov counting. An aliquot is weighed, dissolved, diluted, and then counted directly in a conventional liquid scintillation counter. The internal standard technique is used to provide color quench correction. This method is particularly useful for high specific activity samples. The standard deviation for the analysis of 3 aliquots, each determined in triplicate, was 1.9%.

A revisit to quantitative PET with 18F-FDOPA of high specific activity using a high-resolution condition in view of application to regenerative therapy

2016 ◽  
Vol 31 (2) ◽  
pp. 163-171 ◽  
Author(s):  
Go Akamatsu ◽  
Akihito Ohnishi ◽  
Kazuki Aita ◽  
Hiroyuki Nishida ◽  
Yasuhiko Ikari ◽  
...  
Keyword(s):  
High Resolution ◽  
Specific Activity ◽  
High Specific Activity ◽  
Regenerative Therapy ◽  
Quantitative Pet

Uranium Radioactivity Measurement for Low-Level Wastewater Based on Ultra-Low Level Liquid Scintillation Analyzer

2020 ◽  
Author(s):  
Jinxu Lv ◽  
Ning Lv ◽  
Huiping Guo ◽  
Zeting Hu ◽  
Geng Song ◽  
...  
Keyword(s):  
Mass Concentration ◽  
Liquid Scintillation ◽  
Activity Concentration ◽  
Specific Activity ◽  
Limit Of Detection ◽  
High Specific Activity ◽  
Uranium Isotope ◽  
Low Level ◽  
Radioactivity Level ◽  
Scintillation Method

Abstract In this paper, a method based on ultra-low level liquid scintillation analyzer for measuring uranium radioactivity in low-level radioactive wastewater is proposed. It can easily and quickly measure the radioactivity level of uranium in samples, and even distinguish the main isotopes of uranium. In low-level wastewater samples, if the uranium isotope has the same or similar composition and ratio to the natural uranium isotope, Comparing to the results in units of mass concentration given by laser-fluoremetry method, the liquid scintillation method can give the results in units of activity concentration, and these two results with different units can interconvert to each other. However, interconversion of results on above two measurement methods cannot be applied in low-level wastewater after uranium enrichment, because the proportion of isotopes with high specific activity in above wastewater, such as 234U and 235U, is significantly higher than that without enrichment. The measurement results in units of mass concentration will underestimate the uranium radioactivity level of the sample. The liquid scintillation method directly gives the results in units of radioactivity activity concentration, and it is more convenient to compare with relevant national standards to determine whether the emission standards are met. The lowest limit of detection of this method is 0.014 Bq L−1 within 600 min.

SELECTIVE UPTAKE OF RADIOACTIVITY IN RAT VENTRAL PROSTATE FOLLOWING ADMINISTRATION OF TESTOSTERONE-1,2-3H

1968 ◽  
Vol 59 (2) ◽  
pp. 218-226 ◽  
Author(s):  
Kjell J. Tveter ◽  
Arne Attramadal
Keyword(s):  
Liquid Scintillation Counting ◽  
Liquid Scintillation ◽  
Specific Activity ◽  
Specific Radioactivity ◽  
Scintillation Counting ◽  
Ventral Prostate ◽  
Simultaneous Administration ◽  
Selective Uptake ◽  
Rat Ventral Prostate ◽  
Intact Rats

ABSTRACT Testosterone- 1,2-3H with a specific activity of 46.5 c/mm was injected intramuscularly into 3–4 months old, randomly selected rats castrated 3 days prior to injection. The radioactivity in liver, muscle, blood and the ventral prostate was measured by liquid scintillation counting. A selective uptake of radioactivity was demonstrated in the prostate, with a maximum concentration 1–2 hours following injection. Animals with ureterocolostomy showed the same values, thus eliminating urinary contamination as an explanation for the registered uptake. Simultaneous administration of 20 μg per rat of unlabelled testosterone diminished the uptake in the prostate by an average of 38 % in intact rats, while 500 μg of unlabelled hormone per rat reduced the uptake to background levels in animals castrated 1 day previously. It is suggested that the main reason for earlier failure to demonstrate a selective uptake in the prostate might be the administration of greater amounts of a hormone with too low a specific radioactivity.

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