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Hovi, V. (ed.); Turku Univ. (Finland). Wihuri Physical Lab; p. 346-349; ISBN 0720402735; ; 1973; North-Holland Publishing Company; Amsterdam; 17. Congress AMPERE on magnetic resonance and related phenomena; Turku, Finland; 21 Aug 1972
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Book
Literature Type
Conference
Country of publication
ALKALINE EARTH METAL COMPOUNDS, BETA DECAY RADIOISOTOPES, CHALCOGENIDES, ELECTRIC MOMENTS, ELECTRON CAPTURE RADIOISOTOPES, EVEN-ODD NUCLEI, HOURS LIVING RADIOISOTOPES, INTERMEDIATE MASS NUCLEI, ISOMERIC TRANSITION ISOTOPES, ISOTOPES, MAGNETIC RESONANCE, NUCLEAR PROPERTIES, NUCLEI, OXIDES, OXYGEN COMPOUNDS, PHASE TRANSFORMATIONS, RADIOISOTOPES, RELAXATION, RESONANCE, STABLE ISOTOPES, STRONTIUM COMPOUNDS, STRONTIUM ISOTOPES, TITANIUM COMPOUNDS, TRANSITION ELEMENT COMPOUNDS
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AbstractAbstract
[en] F-18 labeled α,α,α-trifluorotoluenes (2) are the important intermediates for the syntheses of F-18 labeled radiopharmaceuticals. Compounds (2) (Y=H, O-NH/sub 2/, m-NH/sub 2/, m-OH, p-OH, O-CN, p-CN) have been synthesized by the reactions of benzotrifluoride with K/sup 18/F/18-crown-6 ether in 0-14% yield. The authors report here the syntheses of compounds (2) by the reactions of substituted toluenes with H/sup 18/F/SB/sub 2/O/sub 3/ to give compounds (2) in 0-70% radio-chemical yield depending on the substituents on the aromatic ring and the reaction conditions. This method thus provides a new route to F-18 labeled radiopharmaceuticals which contain α,α,α-trifluorotoluene component. For example, 1-(α,α,α-tri[/sup 18/F]fluoro-m-tolyl)piperazine (3), a serotonin agonist has been synthesized in a 2-step synthesis from m-nitro-α,α,α-tri[/sup 18/F]fluorotoluene in 20-30% radiochemical yield
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Secondary Subject
Source
32. annual meeting of the Society of Nuclear Medicine; Houston, TX (USA); 2-5 Jun 1985; CONF-850611--
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Journal Article
Literature Type
Conference
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ANTIMONY COMPOUNDS, AZINES, BETA DECAY RADIOISOTOPES, BETA-PLUS DECAY RADIOISOTOPES, CHALCOGENIDES, CHEMISTRY, DRUGS, FLUORINE ISOTOPES, HETEROCYCLIC COMPOUNDS, HOURS LIVING RADIOISOTOPES, HYDROCARBONS, ISOTOPES, LABELLED COMPOUNDS, LIGHT NUCLEI, MATERIALS, NUCLEI, ODD-ODD NUCLEI, ORGANIC COMPOUNDS, ORGANIC HALOGEN COMPOUNDS, ORGANIC NITROGEN COMPOUNDS, ORGANIC OXYGEN COMPOUNDS, OXIDES, OXYGEN COMPOUNDS, PYRAZINES, RADIOACTIVE MATERIALS, RADIOISOTOPES, SYNTHESIS
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AbstractAbstract
[en] A previous radiolytic study on the gas-phase methylation of pyrrole and N-methylpyrrole by CH3XCH3+ (X = F or Cl) ions, from the ß radiolysis of CH3X, is extended to furan (3) and thiophene (4). The mechanism of the substitution and of the subsequent isomerization occurring via intramolecular 1,2 methyl-group shifts is discussed and the substrate and positional selectivity of the selected electrophilic species evaluated. As for pyrroles, gas-phase CH3FCH3+ methylation of furan and thiophene is characterized by a scarce substrate discrimination (kSkB = 1.2 (3), 0.8 (4)), accompanied by an appreciable positional selectivity toward those substrate positions with the highest negative net charge (O:α:ß = 36%:35%:29% for 3; S:α:ß = 19%:43%:38% for 4). On the contrary, CH3ClCH3+ confirms its inherent affinity toward n-type nucleophilic centers by attacking preferentially the heteroatom of 3 and 4. In light of the previous results concerning CH3XCH3+ methylation of pyrroles, it is concluded that gas-phase attack of CH3XCH3+ on simple five-membered heteroaromatics is essentially regulated by the electrostatic interaction established within the encounter pair. A close correspondence does exist between this rationalization of the present gas-phase results and recent theoretical predictions
Secondary Subject
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Journal Article
Literature Type
Numerical Data
Journal
Journal of the American Chemical Society; ISSN 0002-7863; ; v. 104(25); p. 7091-7098
Country of publication
CHEMICAL RADIATION EFFECTS, CHEMICAL REACTIONS, DATA, DECOMPOSITION, ELECTROMAGNETIC RADIATION, HETEROCYCLIC COMPOUNDS, INFORMATION, IONIZING RADIATIONS, KINETICS, NUMERICAL DATA, ORGANIC CHLORINE COMPOUNDS, ORGANIC COMPOUNDS, ORGANIC FLUORINE COMPOUNDS, ORGANIC HALOGEN COMPOUNDS, ORGANIC OXYGEN COMPOUNDS, ORGANIC SULFUR COMPOUNDS, RADIATION EFFECTS, RADIATIONS, REACTION KINETICS
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AbstractAbstract
[en] Nuclear decay of C3H4 in the presence of gaseous furan represents a simple and convenient synthetic route to carrier-free multitritiated 3-methyl- and 2-methyl-furan. Their application for biological studies appears particularly promising, on account of the favourable characteristics of the followed synthetic approach. (author)
Record Type
Journal Article
Journal
Journal of Labelled Compounds and Radiopharmaceuticals; v. 19(1); p. 39-46
Country of publication
ALKANES, BETA DECAY RADIOISOTOPES, BETA-MINUS DECAY RADIOISOTOPES, CHEMICAL REACTIONS, CHROMATOGRAPHY, DECAY, HETEROCYCLIC COMPOUNDS, HYDROCARBONS, HYDROGEN COMPOUNDS, HYDROGEN ISOTOPES, ISOTOPES, LIGHT NUCLEI, NUCLEAR DECAY, NUCLEI, ODD-EVEN NUCLEI, ORGANIC COMPOUNDS, ORGANIC OXYGEN COMPOUNDS, POLLUTION, RADIOISOTOPES, SEPARATION PROCESSES, SYNTHESIS, YEARS LIVING RADIOISOTOPES
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AbstractAbstract
[en] Triazines are a class of molecules which have been found in meteorites such as Orgueil meteorite. Despite their poor resistance to UV radiation, these molecules survived millions of years inside a meteorite. The present work is dedicated to the examination of the radiation resistance of the simplest sym-triazine: 1,3,5-triazine. The crystals of this molecule have been irradiated with γ-radiation at 50 and 350 kGy and were studied by electronic absorption spectroscopy, liquid chromatography, FT-IR spectroscopy and differential scanning calorimetry (DSC). All the data suggest the relatively low stability of this molecule to high energy radiation. The resulting products from radiolysis are formamidine together with triazine dimers and oligomers. Other radiolysis products are H2, CH4, HCN and other gases
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Source
17 refs.
Record Type
Journal Article
Journal
Journal of Radioanalytical and Nuclear Chemistry; ISSN 0236-5731; ; CODEN JRNCDM; v. 277(2); p. 297-302
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AbstractAbstract
[en] Tritiated napththylium ions, generated by spontaneous β-decay of [1,4-3H] naphthalene, have been allowed to react with benzene molecules in gaseous and liquid phase. The isomeric phenylnaphthalenes and fluoranthene have been found among the reaction products. The differences between the reactivity pattern of naphthylium ion in the two phases can be explained by the different efficiency of collisional stabilization of the excited reaction intermediates. (orig.)
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Journal Article
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AbstractAbstract
[en] The measurement of cerebral blood flow (CBF) by the extracranial detection of the radioactivity of 133Xe injected into an internal carotid artery has proved to be of considerable value for the investigation of cerebral circulation in conscious rabbits. Methods are described for calculating CBF from the curves of clearance of 133Xe, and include exponential analysis (two-component model), initial slope, and stochastic method. The different methods of curve analysis were compared in order to evaluate the fitness with the theoretical model. The initial slope and stochastic methods, compared with the biexponential model, underestimate the CBF by 35% and 46% respectively. Furthermore, the validity of recording the clearance curve for 10 min was tested by comparing these CBF values with those obtained from the whole curve. CBF values calculated with the shortened procedure are overestimated by 17%. A correlation exists between the ''10 min'' CBF values and the CBF calculated from the whole curve; in spite of that, the values are not accurate for limited animal populations or for single animals. The extent of the two main compartments into which the CBF is divided was also measured. There is no correlation between CBF values and the extent of the relative compartment. This fact suggests that these two parameters correspond to different biological entities
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Record Type
Journal Article
Journal
Journal of Pharmacological Methods; ISSN 0160-5402; ; v. 9(3); p. 165-173
Country of publication
ANIMALS, BETA DECAY RADIOISOTOPES, BETA-MINUS DECAY RADIOISOTOPES, BODY, CENTRAL NERVOUS SYSTEM, COUNTING TECHNIQUES, DAYS LIVING RADIOISOTOPES, EVEN-ODD NUCLEI, INTERMEDIATE MASS NUCLEI, ISOMERIC TRANSITION ISOTOPES, ISOTOPES, MAMMALS, NERVOUS SYSTEM, NUCLEI, ORGANS, RADIOISOTOPES, RODENTS, VERTEBRATES, XENON ISOTOPES
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AbstractAbstract
[en] C60 fullerene was radiolyzed in toluene solution both in presence of air and in vacuum at four different radiation doses 12, 24, 36, 48 and 96 kGy. Clear evidences of the addition of benzyl radicals to the fullerene cage derive from FT-IR and C13-NMR spectra of the reaction product. In presence of air the interference of oxygen is evident in the FT-IR spectra and from the elemental analysis. A detailed analysis of the kinetics of the multiple addition of benzyl radicals to the fullerene cage was made spectrophotometrically with the determination of the addition rate constants at the each addition step and the average number of benzyl groups added to the fullerene cage as function of the radiation dose. (author)
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Secondary Subject
Source
13 refs.
Record Type
Journal Article
Journal
Journal of Radioanalytical and Nuclear Chemistry; ISSN 0236-5731; ; CODEN JRNCDM; v. 279(1); p. 31-41
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AbstractAbstract
[en] A single step synthesis of the [14C-ring]N-tert-butyl-α-phenylnitrone (1) starting from the [14C-ring] benzaldehyde is described. The product is obtained in high yield (90%) with a good level of purity. (Author)
Record Type
Journal Article
Journal
Journal of Labelled Compounds and Radiopharmaceuticals; ISSN 0362-4803; ; CODEN JLCRD4; v. 31(4); p. 289-296
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AbstractAbstract
[en] The complete reaction pathway (five steps) for the syntheses of tritiated [CBZ-Pro-*Leu-TrpOH] 7 (POL-443) and [Pyr-*Leu-TrpOMe] 5 (POL-509) starting from tritiated *Leu-[3, 4, 5-3H(N)] is described. The products 5 and 7 are obtained with high level of chemical and radiochemical purity and in good total yield (70% for 5 and 60% for 7) (1). The use of the ''Solid Phase Extraction'' procedure made the purification and recovery steps very simple and effective with no isotopic exchange. (author)
Source
GRANT NIH HD-05797
Record Type
Journal Article
Journal
Journal of Labelled Compounds and Radiopharmaceuticals; ISSN 0362-4803; ; CODEN JLCRD4; v. 31(10); p. 739-757
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