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Takács MP, Kossert K, Nähle O. Activity standardization of 99mTc by digitizer-based 4πce(LS)-γ and 4πce(PC)-γ coincidence counting. Appl Radiat Isot 2023; 200:110962. [PMID: 37540990 DOI: 10.1016/j.apradiso.2023.110962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 07/19/2023] [Accepted: 07/26/2023] [Indexed: 08/06/2023]
Abstract
An aqueous solution of 99mTc was standardized by means of 4πce(LS)-γ and 4πce(PC)-γ coincidence counting. The activity concentration was obtained by efficiency extrapolation relying on four different variation techniques. In both setups, fast digitizers were used for data acquisition. Detected events were recorded in list mode format, and their coincidence relationship was analyzed in the subsequent offline analysis. The combined result was used to participate in an international comparison using the Transfer Instrument of the International Reference System.
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Affiliation(s)
- Marcell P Takács
- Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116, Braunschweig, Germany.
| | - Karsten Kossert
- Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116, Braunschweig, Germany
| | - Ole Nähle
- Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116, Braunschweig, Germany
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van Rooy MW, van Staden MJ, Simpson BRS, Lubbe J. Activity determination of 18F using liquid scintillation beta-efficiency extrapolation and non-extrapolation methods. Appl Radiat Isot 2020; 160:109070. [PMID: 32351212 DOI: 10.1016/j.apradiso.2020.109070] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 12/06/2019] [Accepted: 01/31/2020] [Indexed: 11/29/2022]
Abstract
The absolute activity of 18F was determined using 4πβ-γ liquid scintillation coincidence counting using beta-efficiency extrapolation. An ionization chamber factor was determined for use during a SIRTI comparison, for which results are presented. A non-extrapolation method based on a detection efficiency analysis was also employed using an adaptation of the double-phototube coincidence efficiency for a threshold above the second monopeak. Results and uncertainty budgets for the two methods are presented and discussed.
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Affiliation(s)
- M W van Rooy
- Radioactivity Standards Section, NMISA, 15 Lower Hope Road, Rosebank, 7700, Cape Town, South Africa.
| | - M J van Staden
- Radioactivity Standards Section, NMISA, 15 Lower Hope Road, Rosebank, 7700, Cape Town, South Africa
| | - B R S Simpson
- Radioactivity Standards Section, NMISA, 15 Lower Hope Road, Rosebank, 7700, Cape Town, South Africa
| | - J Lubbe
- Radioactivity Standards Section, NMISA, 15 Lower Hope Road, Rosebank, 7700, Cape Town, South Africa
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Galea R, Michotte C, Nonis M, Moore K, Gamal IE, Keightley J, Fenwick A. The first official measurement of 11C in the SIRTI. Appl Radiat Isot 2019; 154:108834. [PMID: 31536910 DOI: 10.1016/j.apradiso.2019.108834] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 05/06/2019] [Accepted: 08/01/2019] [Indexed: 11/24/2022]
Abstract
In the summer of 2017, the Système International de Référence Transfer Instrument (SIRTI) of the Bureau International des Poids et Mesures (BIPM) was hosted by the National Research Council of Canada (NRC) in Ottawa, Canada. This SIRTI visit was unique in many aspects. It was the first visit of the SIRTI to Canada. NRC was the first National Metrological Institute (NMI) to perform comparisons of four isotopes (99mTc, 18F, 64Cu and 11C) during a single two-week period. Finally, this was the first official measurement of 11C in the SIRTI. The NRC had performed a primary standardization of 11C in February of 2017 and calibrated its Secondary Standard Ionizing Radiation Chamber System (SSIRCS) in preparation for the SIRTI comparison. Two primary Liquid Scintillation methods (CIEMAT/NIST and TDCR) were employed and the results agreed. The stock material was received from a local cyclotron in the form of a 11C-labelled sodium acetate (NaC2H3O2). Three ampoules were prepared for the purposes of comparison; one concentrated from the bulk material and two derived from a single dilution. Some inconsistency was evident due to a weighing problem for one of the ampoules containing the diluted solution, whose measurements were excluded from the analysis. The other two ampoules' results were consistent within their respective uncertainties. The SIRTI was very stable and the final BIPM report will detail the stability checks, performance and behaviour of the SIRTI during its measurement campaign in Canada. There is still no Key Comparison Reference Value (KCRV) for 11C as NRC is the first participant. However, during a test of the SIRTI at NPL in 2014, an equivalent SIRTI activity was measured as 9.87(5) kBq which was consistent with MonteCarlo predictions for 11C in the SIRTI of 9.867(15) kBq. The NRC SIRTI equivalent activity for 11C agrees within uncertainty with these results. This offers encouragement to other NMIs to request a 11C comparison given the consistency of experimental results from NRC and test results from the National Physical Laboratory, UK (NPL) and the BIPM. Finally a half-life measurement was determined from the NRC measurement of multiple half-lives of a 11C ampoule and was found to be 20.332(40)min. From the SIRTI measurements at NRC, the half-life was derived as 20.328(13) min. This is smaller but consistent with the DDEP recommended value of 20.361(23)min.
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Rooy MWV, Staden MJV, Simpson BRS, Lubbe J. Absolute standardizations of 99mTc and 57Co by 4π electron-gamma liquid scintillation coincidence counting for SIRTI and SIR comparisons. Appl Radiat Isot 2018; 134:245-251. [PMID: 28780201 DOI: 10.1016/j.apradiso.2017.07.042] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 07/24/2017] [Accepted: 07/24/2017] [Indexed: 10/19/2022]
Abstract
The radionuclides 99mTc and 57Co were standardized via absolute liquid scintillation counting techniques. We provide the first technical report on the absolute standardization of 99mTc using 4π(LS)e-γ coincidence counting. The low detection efficiency of low-energy conversion electrons translates into a large efficiency extrapolation range. A simulation indicated that the γ-ray interacting with the liquid scintillator introduces curvature to the count rate vs. efficiency relationship, the approximation of the functional form used for extrapolation providing the main measurement uncertainty for 99mTc. A detection efficiency analysis for both radionuclides is presented. Results from the standardizations, and SIRTI and SIR comparison exercises are reported.
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Affiliation(s)
- M W van Rooy
- Radioactivity Standards Section, NMISA, 15 Lower Hope Road, Rosebank, 7700 Cape Town, South Africa.
| | - M J van Staden
- Radioactivity Standards Section, NMISA, 15 Lower Hope Road, Rosebank, 7700 Cape Town, South Africa
| | - B R S Simpson
- Radioactivity Standards Section, NMISA, 15 Lower Hope Road, Rosebank, 7700 Cape Town, South Africa
| | - J Lubbe
- Radioactivity Standards Section, NMISA, 15 Lower Hope Road, Rosebank, 7700 Cape Town, South Africa
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Zeng K, Feng QG, Lin BT, Ma DH, Liu CM. Effects of microRNA-211 on proliferation and apoptosis of lens epithelial cells by targeting SIRT1 gene in diabetic cataract mice. Biosci Rep 2017; 37:BSR20170695. [PMID: 28679650 DOI: 10.1042/BSR20170695] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 06/14/2017] [Accepted: 07/04/2017] [Indexed: 12/11/2022] Open
Abstract
Our study aimed at exploring the effects of miR-211 on the proliferation and apoptosis of lens epithelial cells in diabetic cataract mice by targetting NAD+-dependent histone deacetylase sirtulin 1 (SIRT1). Healthy male mice were assigned into normal and diabetic cataract groups. Blood glucose, lens turbidity, and apoptosis were measured. Lens epithelial cells were classified into the normal, blank, negative control (NC), miR-211 mimics, miR-211 inhibitors, siRNA-SIRT1, and miR-211 inhibitors + siRNA-SIRT1 groups. MiR-211, Bcl-2, Bax, p53, and SIRT1 expressions of each group were detected. Cell proliferation, cycle and apoptosis were tested by MTT assay and flow cytometry. MiR-211 can specifically bind to SIRT1 according to the luciferase system. SIRT1 protein concentration was strongly positive in normal mice and weakly positive in diabetic cataract mice. Apoptosis index of diabetic cataract mice was higher than the normal mice. Compared with normal mice, the expressions of miR-211, Bax, and p53 increased in diabetic cataract mice, while the Bcl-2 and SIRT1 expressions decreased. In comparison with the blank and NC groups, the expressions of miR-211, Bax, and p53 increased, while Bcl-2 and SIRT1 expressions decreased, and the proliferation decreased and apoptosis rate increased in the miR-211 mimics and siRNA-SIRT1 groups; the results were contradicting for the miR-211 inhibitor group. MiR-211 could promote apoptosis and inhibit proliferation of lens epithelial cells in diabetic cataract mice by targetting SIRT1.
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Capogni M, Carconi P, De Felice P, Fazio A. (18)F primary standard at ENEA-INMRI by three absolute techniques and calibration of a well-type IG11 ionization chamber. Appl Radiat Isot 2016; 109:410-413. [PMID: 26774395 DOI: 10.1016/j.apradiso.2015.12.055] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Accepted: 12/28/2015] [Indexed: 10/22/2022]
Abstract
A new (18)F primary standardization carried out at ENEA-INMRI by three different absolute techniques, i.e. 4πγNaI(Tl)γ high-efficiency counting, TDCR and 4πβ(LS)-γ[NaI(Tl)] coincidence counting method, allowed the calibration of a fixed well-reentrant IG11 ionization chamber (IC), with an uncertainty lower than 1%, and to check the calibration factor of a portable well-type IC NPL-CRC model, previously calibrated. By the new standard the ENEA-INMRI was linked to the BIPM International Reference System (SIR) through the BIPM SIR Transfer Instrument (SIRTI).
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Affiliation(s)
- Marco Capogni
- ENEA, Istituto Nazionale di Metrologia delle Radiazioni Ionizzanti (INMRI), C.R. Casaccia, Via Anguillarese, 301, I-00123 Rome, Italy.
| | - Pierluigi Carconi
- ENEA, Istituto Nazionale di Metrologia delle Radiazioni Ionizzanti (INMRI), C.R. Casaccia, Via Anguillarese, 301, I-00123 Rome, Italy
| | - Pierino De Felice
- ENEA, Istituto Nazionale di Metrologia delle Radiazioni Ionizzanti (INMRI), C.R. Casaccia, Via Anguillarese, 301, I-00123 Rome, Italy
| | - Aldo Fazio
- ENEA, Istituto Nazionale di Metrologia delle Radiazioni Ionizzanti (INMRI), C.R. Casaccia, Via Anguillarese, 301, I-00123 Rome, Italy
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Michotte C, Nonis M, Alekseev IV, Kharitonov IA, Tereshchenko EE, Zanevskiy AV, Keightley JD, Fenwick A, Ferreira K, Johansson L, Capogni M, Carconi P, Fazio A, De Felice P. Comparison of (18)F activity measurements at the VNIIM, NPL and the ENEA-INMRI using the SIRTI of the BIPM. Appl Radiat Isot 2015; 109:17-23. [PMID: 26682894 DOI: 10.1016/j.apradiso.2015.11.087] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 11/25/2015] [Indexed: 10/22/2022]
Abstract
In 2014, the first three comparisons of activity measurements of (18)F were carried out at the VNIIM, NPL and the ENEA-INMRI using the BIPM's Transfer Instrument of the International Reference System. The transfer instrument and the NMIs primary measurement methods are briefly described. The degrees of equivalence with the key comparison reference value defined in the frame of the corresponding SIR comparison have been evaluated. World-wide consistency of activity measurements of (18)F is demonstrated.
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Affiliation(s)
- C Michotte
- Bureau International des Poids et Mesures (BIPM), Sèvres, France.
| | - M Nonis
- Bureau International des Poids et Mesures (BIPM), Sèvres, France
| | - I V Alekseev
- D.I. Mendeleyev Institute for Metrology (VNIIM), Russian Federation
| | - I A Kharitonov
- D.I. Mendeleyev Institute for Metrology (VNIIM), Russian Federation
| | - E E Tereshchenko
- D.I. Mendeleyev Institute for Metrology (VNIIM), Russian Federation
| | - A V Zanevskiy
- D.I. Mendeleyev Institute for Metrology (VNIIM), Russian Federation
| | | | - A Fenwick
- National Physical Laboratory (NPL), United Kingdom
| | - K Ferreira
- National Physical Laboratory (NPL), United Kingdom
| | - L Johansson
- National Physical Laboratory (NPL), United Kingdom
| | - M Capogni
- Agenzia nazionale per le nuove tecnologie, l'energia e lo sviluppo economico sostenibile-Istituto Nazionale di Metrologia delle Radiazioni Ionizzanti (ENEA-INMRI), Italy
| | - P Carconi
- Agenzia nazionale per le nuove tecnologie, l'energia e lo sviluppo economico sostenibile-Istituto Nazionale di Metrologia delle Radiazioni Ionizzanti (ENEA-INMRI), Italy
| | - A Fazio
- Agenzia nazionale per le nuove tecnologie, l'energia e lo sviluppo economico sostenibile-Istituto Nazionale di Metrologia delle Radiazioni Ionizzanti (ENEA-INMRI), Italy
| | - P De Felice
- Agenzia nazionale per le nuove tecnologie, l'energia e lo sviluppo economico sostenibile-Istituto Nazionale di Metrologia delle Radiazioni Ionizzanti (ENEA-INMRI), Italy
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