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  • Author or Editor: J. Környei x
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Abstract  

A simple potentiometric method for determination of specific activity of carrier-free125I (NaI) has been elaborated. The method is based on the measurement of tracer amounts of iodide present in the125I preparate, by using an ion-selective membrane electrode. The method presented is suitable in practice for rapid estimation of specific activity of carrier-free125I preparation in cases where the knowledge of its numerical value is necessary.

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Abstract  

Mercaptoacetyltriglycine and its related compounds were synthesized and labeled with99mTc-radionuclide in order to study the effect of substituents and labeling conditions upon the formation of radioactive by-products. Direct labeling and ligand exchange reactions were followed by radio-TLC separation. The direct labeling in alkaline media at elevated temperature provides high radiochemical yields and gives opportunity for a new kit formulation because the neutralization to physiological pH does not cause any change in the chemical identity of the complexes. Compounds with the strongly polar sulfonyl groups show significantly lower protein binding compared with mercaptoacetyltriglycine and may be considered as potential renal agents.

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Abstract  

The intercalation behaviour of some organic derivatives of -zirconium phosphate was investigated. Prepared organic derivatives of -zirconium phosphate can be described by the general formula Zr(RPO3)X(R'PO3)2–X. It was found that only the compound with acidic P–OH groups is able to intercalate different species while the benzene derivatives with phosphite groups do not show any intercalation properties.

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Abstract  

A direct curve simulation treatment has been worked out for the evaluation of the kinetic curves of heterogeneous isotope exchange. Based on the data obtained by a personal computer some considerations have been made on the transport processes in the fully and half exchanged sodium forms of crystalline zirconium phosphate.

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Abstract  

Layered crystalline zirconium phosphates (-, and - modes) and cerium arsenate as well as some of Li or Na-forms were investigated in several polar organic media. Under such conditions dehydration or intercalation processes take place. The X-ray diffraction and the thermoanalytical data refer to the structure and composition of the dehydrated materials or intercalation complexes respectively.

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Abstract  

Model experiments for Ga/Zn separation were carried out using Dowex 1 anion exchanger. Some chemical forms of Ga were identified by radio-paperchromatography and the Rf values have been determined.

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Abstract  

Cephalosporanic acids (CEPHAs) such as dihydro-1,4-thiazine derivatives and 2-hydroxyalkyl-1,3-thiazolidine-4-carboxylic-acids, (HOTCAs) are both important biologically active molecules and complexing agents for several metals such as Fe, Zn, Pb, etc. The simplest way for the study of the effect of complex formation upon the biochemistry of these compounds requires radiolabeled complexes. As99mTc radioisotope gives the best opportunity for imaging the in vivo process,99mTc-CEPHAs and HOTCAs were prepared and investigated. It was found that biologically active molecules like CEPHAs and HOTCAs can be labeled with99mTc with good radiochemical yields. In case of one CEPHA compound, low but definite myocardial uptake was observed, while 3 of the HOTCAs showed characteristic renal uptake and wash-out without visualization of any other organs than the urinary tract.

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