[en] Two 1,2,3-triazole anticonvulsants, 1-(4-methylsulfone-phenyl)-5-(4-fluoro-phenyl)-5-[¹⁴C]-1,2,3-triazole and 1-(4-sulfonamide-phenyl)-5-(4- fluoro-phenyl)-5-[¹⁴C]-1,2,3-triazole, both labeled with carbon-14 in the 5-position were prepared from para-fluoro-benzonitrile-[cyano-¹⁴C]. (author)

[en] Several new syntheses of δ aminolevulic acid (δ A.L.A.) have been studied. ¹⁴C-4 δ - aminolevulic acid has been obtained from ¹⁴C allylacetic carboxylic acid with a yield of 30 per cent with respect to barium carbonate and with a specific activity of 32 mCi/mM. The ¹⁴C-1 or ¹⁴C-2 δ-A.L.A. has been prepared from the ¹⁴C-1 or ¹⁴C-2 acetate with a yield of 55 per cent with respect to the acetate. Finally the tritiated δ-A.L.A. has been obtained for the first time by tritiation of ethyl phthalimidodehydrolevulate. (author)

[en] Our aim was to examine the control of gastric emptying of the oil phase of a mixed solid and liquid meal. Previous studies had shown that liquid dietary fats normally leave the stomach at a slower rate than does water. We wished to determine whether the slower emptying of fats was due to the physical characteristics of food (lower density and greater viscosity than water), to retardation by duodenal feedback mechanisms, or whether both factors contributed. Thus, we quantified the emptying rates of water and sucrose polyester (a nonabsorbable analog of dietary fat) ingested by healthy volunteers as a mixed solid and liquid meal. Gastric emptying was quantified by an intubation-perfusion method incorporating an occlusive jejunal balloon to facilitate recovery. Four phase-specific, nonabsorbable markers were used. [14C[Sucrose octaoleate and polyethylene glycol were incorporated in the meal and traced the lipid and water phases, respectively; [3H]glycerol triether and phenolsulfonphthalein were used as duodenal recovery markers. Sucrose polyester (substituting for dietary fat) was emptied very rapidly, and at about the same rate as was water, in contrast to natural fat, which empties very slowly. Emptying of water was rapid and comparable to that observed after mixed meals containing natural fat. These results imply that gastric emptying of the oil phase is controlled by receptors sensitive to the hydrolytic products of fat digestion and that the slow emptying of dietary fat is not simply due to its lower density

[en] E1- and M2-form factors of ¹⁴C nucleus electroexcitation were obtained in particle-finite nucleus state version of multiparticle shell model

[en] In this second edition of the book, which was published almost three years after the first edition, the authors reiterate and substantiate their doubts as to the basic theories underlying the radiocarbon dating method and the applicability of dendrochronology. (orig/CB)

[en] The usefulness of ¹⁴CO₂ production from (U-¹⁴C) glucose, (U-¹⁴C) glutamate and (¹⁴C) formate as an index of raw milk quality was investigated. Development work showed that the volume of milk sample influenced the detection of radioactivity. The regression coefficient between Log₁₀ of the inital bacterial count and the detection time (the time to reach 2000 cpm) in the presence of 0.13 μCi (U-¹⁴C) glucose/ml was -0.55 (n=119 samples) and the relationship was y=-0.11x+-0.46. The addition of 0.5 μCi (U-¹⁴C) glutamate and 0.5 μCi of (¹⁴C) formate decreased the detection times but did not result in greater predictability. Further study is required before the method could be used to determine the bacteriological quality of milk

[en] [1-¹⁴C]Glycolate metabolism was examined in leafy shoots of soybean plants (Glycine max (L.) Merr., var. Adepta). Only small amounts of ¹⁴C were incorporated into evolved carbon dioxide and glucidic compounds. Free and protein glycine was labelled but higher levels of radioactivity were found in free serine. Changes in the distribution of ¹⁴C with time showed that metabolic conversion glycollate → glycine → serine occurred very early and serine biosynthesis was more important in the shoot than in the leaves. Carbon dioxide labelling was always slight compared to serine labelling. These data suggest strong relations between glycollate and nitrogen metabolism

[en] N-Nitrosobis(2-oxopropyl)amine (BOP), a potent and selective pancreatic carcinogen in the Syrian golden hamster was synthesized with a ¹⁴C label in the alpha carbon. Oxidation of 2-hydroxypropyl-2-hydroxypropyl-1-¹⁴C-amine followed by nitrosation with sodium nitrite and hydrochloric acid gave radio-labeled BOP in 60% yield. (author)

[en] The direct CO₂ absorption method is a fast and economical sample preparation compared to benzene synthesis for ¹⁴C dating in hydrological study. This paper explains sequentially the CO₂ extraction and absorption process using the setup line unit that was recently assembled in the Environmental Tracer Application Group (e-TAG) laboratory. The setup line unit comprises of two main sections, the CO₂ extraction unit and the CO₂ absorption unit. The CO₂ extraction unit comprises of three sub-sections, reaction unit, moisture trap unit and CO₂ storage unit. The CO₂ absorption unit includes three sub-sections, CO₂ storage, flow control and the absorption units. A vacuum pump unit is directly attached to the setup line to generate the required vacuum condition for the process (author)

[en] The effect of initial lactose concentration on lactose uptake rate by kefir free cells, during the lactose fermentation, was studied in this work. For the investigation ¹⁴C-labelled lactose was used due to the fact that labeled and unlabeled molecules are fermented in the same way. The results illustrated lactose uptake rates are about up to two fold higher at lower initial (convolution sign)Be densities as compared with higher initial (convolution sign)Be densities