450 research outputs found
In Vivo Radionuclide Generators for Diagnostics and Therapy
In vivo radionuclide generators make complex combinations of physical and chemical properties available for medical diagnostics and therapy. Perhaps the best-known in vivo generator is 212Pb/212Bi, which takes advantage of the extended half-life of 212Pb to execute a targeted delivery of the therapeutic short-lived α-emitter 212Bi. Often, as in the case of 81Rb/81Kr, chemical changes resulting from the transmutation of the parent are relied upon for diagnostic value. In other instances such as with extended alpha decay chains, chemical changes may lead to unwanted consequences. This article reviews some common and not-so-common in vivo generators with the purpose of understanding their value in medicine and medical research. This is currently relevant in light of a recent push for alpha emitters in targeted therapies, which often come with extended decay chains
Physiological Aspects of Genetics
A considerable amount of evidence indicates that desoxyribonucleic acid is capable of duplicating itself, a property also possessed by genes. (By a self-duplicating material, we mean one which plays some essential role in its own production.) Watson & Crick (1) have proposed a new structure for desoxyribonucleic acid which not only takes into account the existing analytical and x-ray diffraction data but also seems capable of explaining the mechanism of duplication. Their model consists of two helical chains coiled around the same axis, the purine and pyrimidine bases on the inside, the phosphate groups on the outside. The chains are held together by hydrogen bonds between the bases, the adenine residues of either chain being bonded specifically to thymine in the other, and similarly guanine to cytosine. The sequence of bases along one chain is not restricted, but once fixed the sequence along the other chain is determined. This complementarity, which is the most novel feature of the structure, suggests that duplication takes place by separation of the two chains, followed by the synthesis of its complement alongside each chain. The model is supported by recent x-ray diffraction studies (2, 3)
High specific radioactivites of cobalt, platinum, and iridium from photonuclear reactions
The attainment of high specific activities is an important requirement for the detect i on and utilization of radioactivities produced by photonuclear reactions. If an element different from the target element is produced suitable chemical procedures for the separation of the radioactive atoms from the target atoms can usually be found. However, finding rapid and efficient methods for separating isotopes of the target element formed by the (y,n) reaction presents a more difficult problem. To facilitate the study of the properties of cobalt and platinum actiities produced in the synchrotron by (y,n) reactions, an attempt was made to find complexes of these elements which would undergo Szilard-Chalmers type reactions. A portion of the study was also devoted to the investigation of the activities formed by photonuclear reactions in platinum when PtCl-4.xH-2O is irradiated in the x-ray beam of the synchrotron
Development of Physics Applied to Medicine in the UK, 1945–90
Annotated and edited transcript of a Witness Seminar held on 5 July 2005. Introduction by Dr Jeff Hughes.First published by the Wellcome Trust Centre for the History of Medicine at UCL, 2006.©The Trustee of the Wellcome Trust, London, 2006.All volumes are freely available online at: www.history.qmul.ac.uk/research/modbiomed/wellcome_witnesses/Annotated and edited transcript of a Witness Seminar held on 5 July 2005. Introduction by Dr Jeff Hughes.Annotated and edited transcript of a Witness Seminar held on 5 July 2005. Introduction by Dr Jeff Hughes.Annotated and edited transcript of a Witness Seminar held on 5 July 2005. Introduction by Dr Jeff Hughes.Annotated and edited transcript of a Witness Seminar held on 5 July 2005. Introduction by Dr Jeff Hughes.Annotated and edited transcript of a Witness Seminar held on 5 July 2005. Introduction by Dr Jeff Hughes.Annotated and edited transcript of a Witness Seminar held on 5 July 2005. Introduction by Dr Jeff Hughes.Organized with the assistance of Professor John Clifton (UCL) and chaired by Professor Peter Williams (Manchester), this seminar examined the early developments of medical physics in the UK between 1945 and 1990. Participants discussed a range of themes including medical physics before and during the war, the role of the King's Fund and the formation of the Hospital Physicists' Association (HPA), expansion of medical physics outside radiotherapy and to non-radiation physics (ultrasound, medical instrumentation, bioengineering, use of digital computers), developing regional services and links with industry. The seminar finished with a discussion on the changing scene in the 1980s, covering topics such as funding, academic and undergraduate medical physics, imaging, CT, NMR and others. Participants included Mr Tom Ashton, Dr Barry Barber, Professors Roland Blackwell and Terence Burlin, Dr Joseph Blau, Mr Bob (John) Burns, Professors John Clifton, David Delpy, Philip Dendy and Jack Fowler, Dr Jean Guy, Mr John Haggith, Drs John Haybittle, Alan Jennings and John Law, Professors John Mallard and Joe McKie, Mr David Murnaghan, Professor Angela Newing, Dr Sydney Osborn, Professor Rodney Smallwood, Dr Adrian Thomas, Dr Peter Tothill, Mr Theodore Tulley, Professors Peter Wells and John West, and Mr John Wilkinson. Christie D A, Tansey E M. (eds) (2006) Development of physics applied to medicine in the UK, 1945–90, Wellcome Witnesses to Twentieth Century Medicine, vol. 28. London: The Wellcome Trust Centre for the History of Medicine at UCL.The Wellcome Trust Centre for the History of Medicine at UCL is funded by the Wellcome Trust, which is a registered charity, no. 210183
High specific radioactivities of osmium from photonuclear reactions
The investigation described in this thesis has included a study of the activities in iridium, osmium, and rhenium which were produced by photonuclear reactions in osmium and iridium. Osmium activities produced by slow neutron bombardment on osmium metal have also been investigated. During the course of these experiments a method of concentrating osmium activities by the Szilard-Chaimers process was discovered and was further developed
Some aspects of the hot atom chemistry of liquid aromatic halogen compounds
The chemical reactions following nuclear reactions have been studied
for some liquid aromatic halogen compounds with and without I2 present
as radical scavenger as well as in highly diluted mixtures with a
variety of organic solvents, such as simple aliphatic hydrocarbons
and aromatic hydrocarbons. [Continues.
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