1,724,661 research outputs found
Comparative evaluation of serotonin transporter radioligands 11C-DASB and 11C-McN 5652 in healthy humans
No full textAlterations of serotonin transporters (SERT) are implicated in a large number of psychiatric conditions. 11C-(+)-6β-(4- Methylthiophenyl)-1,2,3,5,6α,10β-hexahydropyrrolo[2,1-a]isoquinoline (11C-McN 5652) was the first PET radiotracer successfully developed as a SERT imaging agent. Recently, 11C-3-amino-4-(2- dimethylaminomethylphenylthio)benzonitrile (11C-DASB) was introduced as an alternative to 11C-McN 5652. Comparative evaluation of 11C-DASB and 11C-McN 5652 in baboons indicates that 11C-DASB is associated with (a) lower nonspecific binding in the brain, (b) higher plasma free fraction, and (c) faster plasma clearance and brain uptake kinetics, enabling measurement of SERT parameters in a shorter scanning time. The purpose of this study was to compare these 2 agents in healthy humans. Methods: Six healthy volunteers underwent 2 PET scans on the same day, one with 11C-DASB and one with 11C-McN 5652, in counterbalanced order. Regional distribution volumes (VT) were derived for 16 brain regions by kinetic analysis using the arterial input function. Results: Both 11C-DASB and 11C-McN 5652 displayed similar patterns of accumulation: highest levels in the midbrain, thalamus and striatum; intermediate in the limbic regions; low in the neocortex; and lowest in the cerebellum. 11C-DASB cerebellar VT (10.1 ± 2.0 mL g-1) was lower than that of 11C-McN 5652 (20.8 ± 3.6 mL g-1), indicating lower nonspecific binding. As a result, regional specific-to-non-specific equilibrium partition coefficients (V3″) of 11C-DASB were higher compared with those of 11C-McN 5652 (for example, midbrain V 3″ of 11C-DASB and 11C-McN 5652 were 2.04 ± 0.44 and 1.20 ± 0.34, respectively). The plasma free fraction was 8.9% ± 1.6% for 11C-DASB and was not measurable for 11C-McN 5652. In contrast to the situation observed in baboons, plasma clearances of both compounds were similar in humans, and the minimal scanning times required to derive time-invariant distribution volumes in all regions were comparable for both tracers (95 min). Conclusion: With the exception of the scanning time, predictions from baboon studies were confirmed in humans. The higher specific-to-nonspecific ratios of 11C-DASB are a critical advantage. This property will be especially important for the measurement of SERT in regions with moderate density, such as the limbic regions, where alterations of serotonin transmission might be associated with anxiety and depression
Comparative evaluation of serotonin transporter radioligands 11C-DASB and 11C-McN 5652 in healthy humans
No full textAlterations of serotonin transporters (SERT) are implicated in a large number of psychiatric conditions. 11C-(+)-6β-(4- Methylthiophenyl)-1,2,3,5,6α,10β-hexahydropyrrolo[2,1-a]isoquinoline (11C-McN 5652) was the first PET radiotracer successfully developed as a SERT imaging agent. Recently, 11C-3-amino-4-(2- dimethylaminomethylphenylthio)benzonitrile (11C-DASB) was introduced as an alternative to 11C-McN 5652. Comparative evaluation of 11C-DASB and 11C-McN 5652 in baboons indicates that 11C-DASB is associated with (a) lower nonspecific binding in the brain, (b) higher plasma free fraction, and (c) faster plasma clearance and brain uptake kinetics, enabling measurement of SERT parameters in a shorter scanning time. The purpose of this study was to compare these 2 agents in healthy humans. Methods: Six healthy volunteers underwent 2 PET scans on the same day, one with 11C-DASB and one with 11C-McN 5652, in counterbalanced order. Regional distribution volumes (VT) were derived for 16 brain regions by kinetic analysis using the arterial input function. Results: Both 11C-DASB and 11C-McN 5652 displayed similar patterns of accumulation: highest levels in the midbrain, thalamus and striatum; intermediate in the limbic regions; low in the neocortex; and lowest in the cerebellum. 11C-DASB cerebellar VT (10.1 ± 2.0 mL g-1) was lower than that of 11C-McN 5652 (20.8 ± 3.6 mL g-1), indicating lower nonspecific binding. As a result, regional specific-to-non-specific equilibrium partition coefficients (V3″) of 11C-DASB were higher compared with those of 11C-McN 5652 (for example, midbrain V 3″ of 11C-DASB and 11C-McN 5652 were 2.04 ± 0.44 and 1.20 ± 0.34, respectively). The plasma free fraction was 8.9% ± 1.6% for 11C-DASB and was not measurable for 11C-McN 5652. In contrast to the situation observed in baboons, plasma clearances of both compounds were similar in humans, and the minimal scanning times required to derive time-invariant distribution volumes in all regions were comparable for both tracers (95 min). Conclusion: With the exception of the scanning time, predictions from baboon studies were confirmed in humans. The higher specific-to-nonspecific ratios of 11C-DASB are a critical advantage. This property will be especially important for the measurement of SERT in regions with moderate density, such as the limbic regions, where alterations of serotonin transmission might be associated with anxiety and depression
Comparative evaluation of serotonin transporter radioligands 11C-DASB and 11C-McN 5652 in healthy humans
No full textAlterations of serotonin transporters (SERT) are implicated in a large number of psychiatric conditions. 11C-(+)-6β-(4- Methylthiophenyl)-1,2,3,5,6α,10β-hexahydropyrrolo[2,1-a]isoquinoline (11C-McN 5652) was the first PET radiotracer successfully developed as a SERT imaging agent. Recently, 11C-3-amino-4-(2- dimethylaminomethylphenylthio)benzonitrile (11C-DASB) was introduced as an alternative to 11C-McN 5652. Comparative evaluation of 11C-DASB and 11C-McN 5652 in baboons indicates that 11C-DASB is associated with (a) lower nonspecific binding in the brain, (b) higher plasma free fraction, and (c) faster plasma clearance and brain uptake kinetics, enabling measurement of SERT parameters in a shorter scanning time. The purpose of this study was to compare these 2 agents in healthy humans. Methods: Six healthy volunteers underwent 2 PET scans on the same day, one with 11C-DASB and one with 11C-McN 5652, in counterbalanced order. Regional distribution volumes (VT) were derived for 16 brain regions by kinetic analysis using the arterial input function. Results: Both 11C-DASB and 11C-McN 5652 displayed similar patterns of accumulation: highest levels in the midbrain, thalamus and striatum; intermediate in the limbic regions; low in the neocortex; and lowest in the cerebellum. 11C-DASB cerebellar VT (10.1 ± 2.0 mL g-1) was lower than that of 11C-McN 5652 (20.8 ± 3.6 mL g-1), indicating lower nonspecific binding. As a result, regional specific-to-non-specific equilibrium partition coefficients (V3″) of 11C-DASB were higher compared with those of 11C-McN 5652 (for example, midbrain V 3″ of 11C-DASB and 11C-McN 5652 were 2.04 ± 0.44 and 1.20 ± 0.34, respectively). The plasma free fraction was 8.9% ± 1.6% for 11C-DASB and was not measurable for 11C-McN 5652. In contrast to the situation observed in baboons, plasma clearances of both compounds were similar in humans, and the minimal scanning times required to derive time-invariant distribution volumes in all regions were comparable for both tracers (95 min). Conclusion: With the exception of the scanning time, predictions from baboon studies were confirmed in humans. The higher specific-to-nonspecific ratios of 11C-DASB are a critical advantage. This property will be especially important for the measurement of SERT in regions with moderate density, such as the limbic regions, where alterations of serotonin transmission might be associated with anxiety and depression
Herdenking van Joseph Maria Franciscus Jaspars (16 maart 1934 - 31 juli 1985)
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5652.pdf (Publisher’s version ) (Open Access
[Atlantic Coast Line, Locomotive 910, Erecting Card Drawing No. 5652]
No full textErecting card drawing for Atlantic Coast Line.This erecting drawing was created for Atlantic Coast Line Locomotive 910, Class 10-32 D 801. Erecting Card 5652. Index Number: 467A-52. For more technical details on this drawing, see Baldwin Erecting Drawings by Road Name: http://www.smu.edu/~/media/Site/libraries/degolyer/pdfs/BLW-EDWG-RoadName.pdf and/or Baldwin Erecting Drawings by Class Number: https://www.smu.edu/~/media/Site/libraries/degolyer/pdfs/BLW-EDWG-Class.pdf (Note: Search by Index Number or Erecting Card Number)
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
nota a Tar Lazio, sez. I bis, 12 maggio 2016, n. 5652
No full textLa nota esamina la sentenza Tar Lazio, sez. I bis, 12 maggio 2016, n. 5652 che non attribuisce efficacia 'ultra partes' all'ordinanza del giudice amministrativo che sospende un regolamento o un atto amministrativo general
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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