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- Silberzahn, Raphael, et al.
(författare)
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Many analysts, one dataset : Making transparent how variations in analytical choices affect results
- 2018
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Ingår i: Advances in Methods and Practices in Psychological Science. - : Sage Publications. - 2515-2459 .- 2515-2467. ; 1:3, s. 337-356
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Tidskriftsartikel (refereegranskat)abstract
- Twenty-nine teams involving 61 analysts used the same dataset to address the same research question: whether soccer referees are more likely to give red cards to dark skin toned players than light skin toned players. Analytic approaches varied widely across teams, and estimated effect sizes ranged from 0.89 to 2.93 in odds ratio units, with a median of 1.31. Twenty teams (69%) found a statistically significant positive effect and nine teams (31%) observed a non-significant relationship. Overall 29 differentanalyses used 21 unique combinations of covariates. We found that neither analysts' prior beliefs about the effect, nor their level of expertise, nor peer-reviewed quality of analysis readily explained variation in analysis outcomes. This suggests that significant variation in the results of analyses of complex data may be difficult to avoid, even by experts with honest intentions. Crowdsourcing data analysis, a strategy by which numerous research teams are recruited to simultaneously investigate the same research question, makes transparent how defensible, yet subjective analytic choices influence research results.
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- Stepanov, Vladimir, et al.
(författare)
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Development of [C-11]/[H-3-1]THK-5351-A potential novel carbon-11 tau imaging PET radioligand
- 2017
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Ingår i: Nuclear Medicine and Biology. - : Elsevier BV. - 0969-8051 .- 1872-9614. ; 46, s. 50-53
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Due to the rise in the number of patients with dementia the imperative for finding new diagnostic and treatment options becomes ever more pressing. While significant progress has been made in PET imaging of A beta aggregates both in vitro and in vivo, options for imaging tau protein aggregates selectively are still limited. Based on the work previously published by researchers from the Tohoku University, Japan, that resulted in the development of [F-18]THK-5351, we have undertaken an effort to develop a carbon-11 version of the identical structure - [C-11]THK-5351. In parallel, THK-5351 was also labeled with tritium ([H-3]THK-5351) for use in in vitro autoradiography (ARG). Methods: The carbon -11 labeling was performed starting with di-protected enantiomeric pure precursor-tertbutyl 5-(6-( (2S)-3-fluoro-2-(tetrahydro-2H-Pyran-2-yloxy)proPoxy)quinolin-2-yl)pyridin-2-yl carbamate, which was reacted with [C-11]MeI, using DMF as the solvent and NaH as base, followed by deprotection with trifluoroacetic acid/water mixture, resulting in enantiomerically pure carbon-11 radioligand,[C-11]THK-5351 (S)-1-fluoro-3-(2-(6-([C-11]methylamino)pyridin-3-yl)quinolin-6-yloxy)propan-2-ol. Tritium labeling and purification of [H-3]THK-5351 were undertaken using similar approach, resulting in [H-3]THK-5351 with RCP >99.8% and specific radioactivity of 13 GB q/mu mol. Results: [C-11]THK-5351 was produced in good yield (1900 +/- 355 MBq), specific radioactivity (SRA) (361 +/- 119 GBq/mu rnol at EOS + 20 min) and radiochemical purity (RCP) (>99.8%), with enantiomeric purity of 98.7%. [H-3]TM-5351 was evaluated for ARG of tau binding in post-mortem human brain tissue using cortical sections from one AD patient and one control subject. [H-3]THK-5351 binding density was higher in the AD patient compared to the control subject, the binding was displaced by unlabeled THK-5351 confirming specific [H-3] THK-5351 binding. (C) 2016 Elsevier Inc. All rights reserved.
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