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Abstract  

The calculating the probability of the cell killing per hit, from radon progeny, requires the development of morphometric model of the human airway system. This study is focused on the different modeling concept. For example, several morphometric lung models have been published which differ in terms of airway structure and lung volume, there by affecting the particle deposition efficiencies. The present variety of modeling concepts suggests that the choice of specific modeling assumptions is as important for dose risk estimates as the choice of proper parameter values. The model of human lung analysed in the present study differ from those employed in the ICRP66 model, dose estimates will consequently differ from ICRP66 predictions, because its included the area of the branching the cylinders (airways tube) in the human lung. A analytical model cylinder bifurcation was created to simulate the geometry of human lung with the geometric distribution of cell nuclei in the airway wall of the tracheobronchial tree. Reported probabilities are calculated for various targets and alpha particle energies in order to show dependence of the probability of cell killing per hit from alpha particle energies and the geometry of tracheobronchial tree for the human lung, created in this study.

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Neurochemical lateralization has been demonstrated in the rat brain suggesting that such lateralization might contribute to behavior. Thus, the aim of the present study was to examine neurochemical asymmetry in the hippocampus, molecular basis of neurochemical lateralization and its impact on spatial learning and memory. Changes in noradrenaline content, tyrosine hydroxylase (TH) were studied in the right and left hippocampus of naive control and chronically isolated rats, by applying TaqMan RT-PCR and Western blot analysis. Hippocampal-based spatial learning and memory were evaluated using the Barnes maze. In control rats an asymmetrical right-left distribution of noradrenaline content and gene expression of catecholamine synthesizing enzyme was found. Chronic psychosocial stress further emphasized asymmetry. Isolation stress reduced noradrenaline content only in the right hippocampus. No changes were observed in gene expression and protein levels of TH in the right hippocampus, whereas expression of catecholamine synthesizing enzyme was elevated in the left hippocampus. Reduced noradrenaline content in the right hippocampus did not cause impairment in spatial learning and memory. Our findings suggest that chronic psychosocial stress reduces noradrenaline stores in the right hippocampus which may be caused by molecular asymmetry, but it does not affect spatial learning and memory.

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Abstract  

The results obtained for radiochemical purity of ITLC (SA) and (SG) using different solvent systems and low voltage electrophoresis are presented in the paper. Radiochemical purities obtained for99mTc-dimethyl IDA (99mTc-HIDA) and99mTc-diethyl IDA (99mTc-EHIDA) are 98.1±0.6% and 98.7±0.5%, respectively. Variable99mTc hydrolyzate contents, depending on the ionic strength of the eluents and on the time interval between labelling and analysis, have been obtained by Sephadex chromatography. The eluent containing Sn-EHIDA inhibits dissociation of99mTc-EHIDA due to dilution of the preparation during elution of the column and yielding only a small percent of Sephadex bound fraction, as compared to other investigated eluents. The range of normal99mTc-IDA biodistribution values in the organs of experimental animals and statistical significance of the difference between these two preparations have also been determined. The results obtained for99mTc-HIDA and99mTc-EHIDA in the liver are 33.9±5% and 25.7±4.7%, respectively p<0.01.

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Abstract  

The results of radiochemical purity measurements for99mTc–S colloid, 90.7±1.4, and99mTc–Sn colloid, 98.9±1.2 obtained by ITLC (SG) with 80% methanol are given. The range of biodistribution normal values for99mTc colloid preparations for animal organs is determined. The results of99mTc–S and99mTc–Sn colloid distribution in liver are 95.4±6.1% and 100,0±5.4%, respectively.

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Abstract  

A broadly applicable, flexible and user-friendly PC-code (ANGLE) for calculations of semiconductor detector full energy peak efficiencies (
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. Written in Pascal, and operating in windows and menus data manipulation mode, ANGLE yields the efficiencies for: (1) HPGe true- and closed-end coaxial (bothn- andp-types), (2) Ge(Li) open- and closed-end, (3) planar LEPD and (4) well-type detectors. Supposing coaxial positioning, cylindrical or Marinelli sources can be treated, regardless of their dimensions (this includes point, disk and ring sources, bulky samples and infinite geometrics). Possible displacement between source and detector axes is treated in our another work, relative to this one. ANGLE input parameters are: (1) reference efficiency curve for the detector used (i.e., efficiency vs. -energy for calibrated point sources at a reference distance), (2) detector type and configuration (active body and inactive layers, end cap, windows, housing, shielding, (3) source data (dimension and composition of both container and active material), (4) source-detector geometry (distance, intercepting layers and their composition) and (5) some computational data (Gauss integration coefficients). Gamma-attenuation is calculated upon an extensive (per element and per energy) data file. In the output, efficiency vs. -energy is found, both in forms of tables and graphs. In routine applications accuracies of 3–4% are achieved (not worse than 7% for the most unfavourable geometries). Computation times when using recent PC models are of the order of minutes. ANGLE frame is also easily adjustable to other semiempirical or Monte Carlo models for efficiency calculations.
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Journal of Radioanalytical and Nuclear Chemistry
Authors:
M. Jovanović
,
B. Zmbova
,
T. Maksin
,
V. Jovanović
,
M. Odavić
,
M. Rastovac
, and
N. Simova

Abstract  

A procedure for obtaining a stable99mTc(V)-DMSA kit and methods for its radiochemical and biological control are described. The effect of pH on radiopharmaceutical stability of the complex was studied. The kinetic parameters of99mTc(V)-DMSA were determined on rats and compared to the corresponding values for renal99mTC-DMSA. Clinical tests showed that99mTc(V)-DMSA is suitable agent for detecting the primary medullar carcinoma of thyroid, as well as for detection of thyroid metastasis.

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Journal of Thermal Analysis and Calorimetry
Authors:
M. Komljenović
,
Lj. Petrašinović-Stojkanović
,
Z. Baščarević
,
N. Jovanović
, and
A. Rosić

Abstract  

This paper presents the results of investigation of properties of fly ash from four major thermal power plants in Serbia. Chemical, mineralogical and thermal characterization of fly ash has been performed in order to determine the possibility of its use as the raw material for the construction material industry, primarily the cement industry. Thermal properties of the raw mixtures for Portland cement clinker production based on fly ash were also investigated. The conclusion was reached that the use of fly ash as a component of the raw mixture components for the production of cement clinker not only enables substitution of natural raw materials, but could also have a positive influence on reduction of the sintering temperature of Portland cement clinker.

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Abstract  

We known activities of two large cylindrical
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, in order to analyse the feasibility and the accuracy of the method. It is applied here under conditions not favourable to the method itself, which are however quite common in practice: (1) HPGe detector supplied only with standard detector specification and performance data, and (2) large source just above the detector end-cap. The impact of the probable range of uncertainties in knowledge of the detector and source geometrical parameters on the calculated efficiencies is considered. The fact that the crystal of the detector used is not coaxial with the end-cap, discovered by making X-ray radiographs, is of a special concern with respect to the applicability of the method under such conditions. Therefore, the method for the calculations of is extended to cases of parallel but not coincident axes of the cylindrical sources and detectors. True coincidence effects, which introduce typically 5% errors for the counting geometry used, are not dealt with.
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Abstract  

The nonideality of the epithermal neutron flux distribution at a reactor site can be described by a 1/E1+ spectrum representation, with parameter being a measure of the nonideality. -values were determined in 3 typical irradiation positions of the TRIGA MARK II reactor of the Jozef Stefan Institute, Ljubljana, Yugoslavia, using the Cd-ratio for multi-monitor method. The simpler Cd-ratio for dual monitor method (monitors:197Au–94Zr) also yielded reliable results. This characterisation is of use in the k0-method of NAA, which is recently introduced at the Institute.

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Abstract  

The computer program SOLANG, originally developed by MOENS et al. for the efficiency conversion via effective solid angles (
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(bulky source counted at the top of detector), discrepancies were below 7% in the whole range of gamma-energies considered (88–1115 keV), with an average of 3–4%. EXTSANGLE is extensive and flexible with respect to the data input, storage and output, thus contributing to the automation of a gamma-spectrometry laboratory dealing, for instance, with the k0-NAA and/or environmental radioactivity monitoring.
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