7 research outputs found

    Clinical performance and radiation dosimetry of no-carrier-added vs carrier-added 123I-metaiodobenzylguanidine (MIBG) for the assessment of cardiac sympathetic nerve activity

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    Purpose We hypothesized that assessment of myocardial sympathetic activity with no-carrier-added (nca) I-123-metaiodobenzylguanidine (MIBG) compared to carrier-added (ca) I-123-MIBG would lead to an improvement of clinical performance without major differences in radiation dosimetry. Methods In nine healthy volunteers, 15 min and 4 h planar thoracic scintigrams and conjugate whole-body scans were performed up to 48 h following intravenous injection of 185 MBq I-123-MIBG. The subjects were given both nca and ca I-123-MIBG. Early heart/mediastinal ratios (H/M), late H/M ratios and myocardial washout were calculated. The fraction of administered activity in ten source organs was quantified from the attenuation-corrected geometric mean counts in conjugate views. Radiation-absorbed doses were estimated with OLINDA/EXM software. Results Both early and late H/M were higher for nca I-123-MIBG (ca I-123-MIBG early H/M 2.46 +/- 0.15 vs nca I-123-MIBG 2.84 +/- 0.15, p = 0.001 and ca I-123-MIBG late H/M 2.69 +/- 0.14 vs nca I-123-MIBG 3.34 +/- 0.18, p = 0.002). Myocardial washout showed a longer retention time for nca I-123-MIBG (p <0.001). The effective dose equivalent (adult male model) for nca I-123-MIBG was similar to that for ca I-123-MIBG (0.025 +/- 0.002 mSv/MBq vs 0.026 +/- 0.002 mSv/MBq, p = 0.055, respectively). Conclusion No-carrier-added I-123-MIBG yields a higher relative myocardial uptake and is associated with a higher myocardial retention. This difference between nca I-123-MIBG and ca I-123-MIBG in myocardial uptake did not result in major differences in estimated absorbed doses. Therefore, nca I-123-MIBG is to be preferred over ca I-123-MIBG for the assessment of cardiac sympathetic activit

    A History of Universalism: Conceptions of the Internationality of Science from the Enlightenment to the Cold War

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    That science is fundamentally universal has been proclaimed innumerable times. But the precise geographical meaning of this universality has changed historically. This article examines conceptions of scientific internationalism from the Enlightenment to the Cold War, and their varying relations to cosmopolitanism, nationalism, socialism, and 'the West'. These views are confronted with recent tendencies to cast science as a uniquely European product

    The young J. H. van't Hoff: The background to the publication of his 1874 pamphlet on the tetrahedral carbon atom, together with a new English translation

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    J. H. van't Hoffs 1874 Dutch pamphlet, in which he proposed the spatial arrangement of atoms in a molecule, is one of the most significant documents in the history of chemistry. This essay presents a new narrative of Van 't Hoffs early life and places the appearance of the pamphlet within the context of the 'second golden age' of Dutch science. We argue that the combination of the reformed educational system in The Netherlands, the emergence of graphical molecular modelling within the theoretical and practical culture of chemistry during the 1860s and 1870s, as well as Van 't Hoffs own personal research trajectory, formed the background to his unprecedented attribution of spatial meaning to the traditional concept of atomic 'arrangement'. We also present a new English translation of the pamphlet, for we have found that the existing translation, published by G. M. Richardson in 1901, contains many errors, changes and omissions. The new Version offers a more accurate rendition in English of Van 't Hoffs style and argument
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