摘要:

Kinetic isotope effects on enzyme catalyzed reactions are indicative for the first irreversible in a sequence of individual steps. Hints on the relative velocities of other steps can only be obtained from the partitioning factor R and its dependence on external reaction conditions. In general, the experimental data needed are obtained from isotope abundance measurements in a defined position of the substrate or product as a function of turnover. This method does not reveal events dealing with neighbour atoms or preceeding the main isotope sensitive step.

ISSN:0021-1915    

DOI:10.1080/10256019108622450

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

With the experimental detection of high temperature superconduction (HTSC) a lot of different new concepts for the explanation of this phenomenon have been developed. After a short reminiscence of the conventional theory of superconduction these new approaches are outlined and discussed.

ISSN:0021-1915    

DOI:10.1080/10256019108622451

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The paper presents a terrestrial food chains model for computing potential human intake of radionuclides released into the atmosphere during normal NPP operation. Attention is paid to the choice of model parameter values. Results obtained by our approach are compared to those applied in current methodology.

ISSN:0021-1915    

DOI:10.1080/10256019108622452

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The derived limits in imported foodstuffs are established to correspond an annual dose about 2.5 mSv. About 12640 food samples during the year 1987 were measured for radiocesium contamination. The distribution of contamination level is reported. The resultant annual dose as well as collective dose up to age 70 years were estimated to infants children and adults. The results are discussed with respect to possible risks to the population from imported foodstuffs.

ISSN:0021-1915    

DOI:10.1080/10256019108622453

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

ISSN:0021-1915    

DOI:10.1080/10256019108622454

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Lower land mosses uptake water and minerals from the atmosphere. They can collect metals polluting the air and radioactive fallout elements so they can be suitable for monitoring of these substances. Cesium ion uptake by Hypnum cupressiforme is studied by a radioactive tracer,134Cs. The quantity of cesium ion in different cellular locations and the capacity of ion uptake is determined. The total capacity is found to be several times 10−3mol g−1and is therefore of the same order of magnitude as the cation exchange capacity of ion exchangers. The kinetics and reversibility of the process is studied as well.

ISSN:0021-1915    

DOI:10.1080/10256019108622455

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Data on intakes of137Cs from various foodstuffs are given. It has been shown that since 1988 the critical pathway of internal exposure for individual members of population is the consumption of wild mushrooms.

ISSN:0021-1915    

DOI:10.1080/10256019108622456

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Two experiments each with 12 growing rats as model-animals were conducted for studying the diminution of the137Cs-absorption from radiocesiwn-contaminatedfoods as well as the enhanced excretion of incorporatedl37Cs by food-supple mentation with 400 ppm Ammoniumferrihexacyanoferrat (so called GIESE-salt). Thel37Cs excretion via faeces was in creased due to this GIESE-sall, forming an insoluble Cs-complex.

ISSN:0021-1915    

DOI:10.1080/10256019108622457

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The experiment was performed on 115 Wistar rats divided into 3 groups: I – the controls, which were administered i.g. with 14 kBq per rat with Cs-137 and the radioactivities of internal organs and muscles 16 samples were measured on days 1, 3 and 7; II – treated with ferric ferrocyanide FF or ammonium-ferric-cyano-ferrate AFCF on day 1 after the Cs-137 administration and thereafter they followed the same procedure as the controls; III – treated with FF or AFCF 2-fold/day for 5 days and the organ radioactivities were measured on day 7. The results indicated that FF and AFCF increased the biological elimination of Cs-137, especially on days 1–3. The decontamination effectiveness of AFCF was higher than that of FF. The repeated treatment increased the decontamination effectiveness.

ISSN:0021-1915    

DOI:10.1080/10256019108622458

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The validity of radioimmunoassays of each of luteinizing hormone, follecile stimulating hormone, prolactin, thyroid stimulating hormone and insulin was assessed from the point of view of iodinated tracer purity of one type of commercial clinical radioimmunoassay kits. The use of high resolution gel filtration made it possible to purify further the standard iodinated tracers. Comparative radioimmunoassays using the unpurified preparations and the purified fractions enabled the detection of overestimations as well as underestimations of standards and unknowns in all the investigated hormones, together with non-specific binding effect noticed with the use of the unpurified iodinated preparations.

ISSN:0021-1915    

DOI:10.1080/10256019108622459

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor