Tafel-analysis of the AP-CITROX decontamination technology of Inconel alloy 690

Safe, effective, cost-effective, easy feasible and low-waste decontamination technologies are fundamental importance from environmental and radiation protection aspects. In this study the effectiveness of AP-CITROX decontamination technology of Inconel alloy 690 was investigated. Non-radioactive representative metal samples were formed to test of decontamination technology and the clear-, the corroded-, the decontaminated layer were analysed electrochemically. The results indicate that the passivation step of the technology was not completed.

Enhancing properties of PC/PA blends via compatibilization of olefin-maleic-anhydride copolymer based additives in masterbatch form

Polymer blending has been a simple and efficient way for designing and controlling the performance of polymeric materials using easily available types. Both polycarbonate and polyamide have excellent mechanical properties and thermal stability but their disadvantages such as limited chemical or water resistance can be eliminate by tailoring them. Main difficulties in processing of PC/PA blends are the poor compatibility and high moisture adsorption capacity of the two raw materials complicating processing and also deteriorating mechanical properties of the products. Compatibilizing additives such as olefin-maleic-anhydride copolymer based compounds used in the experimental work can help to overcome the abovementioned difficulties. To determine the processing conditions of the raw materials several drying temperatures have been tested and thermal degradation has been examined by FT-IR spectroscopy. Experimental compatibilizing additives based on an olefin-maleic-anhydride copolymer have been investigated to enhance mechanical properties of the blends prepared by extrusion moulding. Mechanical, rheological, SEM and FT-IR measurements have been performed and at least one additive has been found to be efficient in improving selected properties.

Radiological impact assessment of different building material additives

In this study, samples of building material additives were analyzed for naturally occurring radioisotope activity such as uranium, radium, and radon. The radon exhalation and the annual effective doses, were also calculated. The activities of the samples, were determined using HPGe gamma spectrometry and ionization detector. The results were used to calculate dose values by using RESRAD BUILD code. The activity concentration of the samples ranges between 9–494 Bq/kg Ra-226, 1–119 Bq/kg Th-232 and 24–730 Bq/kg K-40. In conclusion the investigated samples can be used safely as building material additives as they do not pose a major risk to humans.

Intercomparison on the measurement of the thoron exhalation rate from building materials

Thoron (²²⁰Rn) exhalation from building materials has become increasingly recognized as a potential source for radiation exposure in dwellings. However, contrary to radon (²²²Rn), limited information on thoron exposure is available. As a result no harmonized test procedures for determining thoron exhalation from building materials are available at present. This study is a first interlaboratory comparison of different test methods to determine the thoron exhalation and a pre-step to a harmonized standard. The purpose of this study is to compare the experimental findings from a set of three building materials that are tested, and to identify future challenges in the development of a harmonized standard.

Comparison of analytical methods for measuring chloride content in crude oil

Although chloride compounds are the main cause of corrosion damage in distillation unit, standard methods to determine them do not guarantee good results. In this study, the chloride concentration of different crude oils was measured using different techniques and the results were compared. ASTM D3230, D4929 as standard methods, XRF as alternative technique and Neutron Activation Analysis as reference method, were applied. It is concluded that XRF method is an effective technique for measuring the chloride concentration of oils.

How can contemporary climate research help understand epidemic dynamics? Ensemble approach and snapshot attractors

Standard epidemic models based on compartmental differential equations are investigated under continuous parameter change as external forcing. We show that seasonal modulation of the contact parameter superimposed upon a monotonic decay needs a different description from that of the standard chaotic dynamics. The concept of snapshot attractors and their natural distribution has been adopted from the field of the latest climate change research. This shows the importance of the finite-time chaotic effect and ensemble interpretation while investigating the spread of a disease. By defining statistical measures over the ensemble, we can interpret the internal variability of the epidemic as the onset of complex dynamics-even for those values of contact parameters where originally regular behaviour is expected. We argue that anomalous outbreaks of the infectious class cannot die out until transient chaos is presented in the system. Nevertheless, this fact becomes apparent by using an ensemble approach rather than a single trajectory representation. These findings are applicable generally in explicitly time-dependent epidemic systems regardless of parameter values and time scales.

Synaptic organization of cortico-cortical communication in primates

In cortical circuitry, synaptic communication across areas is based on two types of axon terminals, small and large, with modulatory and driving roles, respectively. In contrast, it is not known whether similar synaptic specializations exist for intra-areal projections. Using anterograde tracing and three-dimensional reconstruction by electron microscopy (3D-EM), we asked whether large boutons form synapses in the circuit of somatosensory cortical areas 3b and 1. In contrast to observations in macaque visual cortex, light microscopy showed both small and large boutons not only in inter-areal pathways, but also in long-distance intrinsic connections. 3D-EM showed that correlation of surface and volume provides a powerful tool for classifying cortical endings. Principal component analysis supported this observation and highlighted the significance of the size of mitochondria as a distinguishing feature of bouton type. The larger mitochondrion and higher degree of perforated postsynaptic density associated with large rather than to small boutons support the driver-like function of large boutons. In contrast to bouton size and complexity, the size of the postsynaptic density appeared invariant across the bouton types. Comparative studies in human supported that size is a major distinguishing factor of bouton type in the cerebral cortex. In conclusion, the driver-like function of the large endings could facilitate fast dissemination of tactile information within the intrinsic and inter-areal circuitry of areas 3b and 1.

Diffusion and escape times in the open-leaky standard map

We study the connection between transport phenomenon and escape rate statistics in two-dimensional standard map. For the purpose of having an open phase space, we let the momentum coordinate vary freely and restrict only angle with periodic boundary condition. We also define a pair of artificial holes placed symmetrically along the momentum axis where the particles might leave the system. As a consequence of the leaks the diffusion can be analyzed making use of only the ensemble of survived particles. We present how the diffusion coefficient depends on the size and position of the escape regions. Since the accelerator modes and, thus, the diffusion are strongly related to the system's control parameter, we also investigate effects of the perturbation strength. Numerical simulations show that the short-time escape statistics do not follow the well-known exponential decay especially for large values of perturbation parameters. The analysis of the escape direction also supports this picture as a significant amount of particles skip the leaks and leave the system just after a longtime excursion in the remote zones of the phase space.

Fecal expression of Escherichia coli lysine decarboxylase (LdcC) is downregulated in E-cadherin negative lobular breast carcinoma

Breast cancer is characterized by oncobiosis, the abnormal composition of the microbiome in neoplastic diseases. The biosynthetic capacity of the oncobiotic flora in breast cancer is suppressed, as suggested by metagenomic studies. The microbiome synthesizes a set of cytostatic and antimetastatic metabolites that are downregulated in breast cancer, including cadaverine, a microbiome metabolite with cytostatic properties. We set out to assess how the protein expression of constitutive lysine decarboxylase (LdcC), a key enzyme for cadaverine production, changes in the feces of human breast cancer patients (n = 35). We found that the fecal expression of Escherichia coli LdcC is downregulated in lobular cases as compared to invasive carcinoma of no special type (NST) cases. Lobular breast carcinoma is characterized by low or absent expression of E-cadherin. Fecal E. coli LdcC protein expression is downregulated in E-cadherin negative breast cancer cases as compared to positive ones. Receiver operating characteristic (ROC) analysis of LdcC expression in lobular and NST cases revealed that fecal E. coli LdcC protein expression might have predictive values. These data suggest that the oncobiotic transformation of the microbiome indeed leads to the downregulation of the production of cytostatic and antimetastatic metabolites. In E-cadherin negative lobular carcinoma that has a higher potential for metastasis formation, the protein levels of enzymes producing antimetastatic metabolites are downregulated. This finding represents a new route that renders lobular cases permissive for metastasis formation. Furthermore, our findings underline the role of oncobiosis in regulating metastasis formation in breast cancer.

The transfer of 241Am and 137Cs to the tissues of broilers' organs

Data on the transfer of artificial radionuclides from the environment to the food supply is necessary for internal dose assessment. There is a necessity for expanding and improving the available information on these factors in order to make better dose models for specific scenarios. This paper describes the results of a field experiment with broiler chickens on the transfer factor (Ff) and concentration ratio (CR) for the long-term intake of 241Am and 137Cs with grass meal and soil. The broilers were divided into two groups, each group had nine subgroups and each subgroup had three broilers. The radionuclide concentrations in the feed and the thigh muscle, thigh bone, and liver of 54 broilers divided between the grass meal and soil groups were evaluated by gamma spectrometry for 241Am and 137Cs. The duration of feeding with "contaminated" sources ranged between 1-70 days. The equilibrium stage of 241Am in muscle and bone occurs on the 1st and 40th day, respectively; for 137Cs in muscle- 30th days of intake and for liver and bone- 7th days. For 241Am, the liver did not reach equilibrium stage during the 70 days of intake. Ff of 137Cs in the "forage-muscle" and "soil-muscle" systems were determined as 1.9±0.3 and 0.18±0.05; Ff of 241Am in the "soil-muscle" system was-7.5×10-5.

A brief review on the rising incidence of chronic kidney diseases and non-alcoholic fatty liver disease

Chronic kidney diseases (CKDs) are the most common forms of kidney disease all around the world. The incidence of CKD is rising, which is mainly driven by population aging as well as by a global rise in hypertension, metabolic syndrome, and metabolic risk factors, particularly obesity and type-2 diabetes. The high mortality, morbidity of CKD, and the health care costs of the renal replacement therapy have led investigators to seek recent and potentially modifiable risk factors such as non-alcoholic fatty liver disease (NAFLD). NAFLD is the hepatic manifestation of metabolic syndrome and the most common cause of chronic liver disease. It incorporates a spectrum of liver diseases ranging from simple steatosis to steatohepatitis, liver cirrhosis, and hepatocellular carcinoma. On the basis of recent publications, the prevalence of CKD is significantly increased among patients with NAFLD, and the prevalence of NAFLD is also higher in CKD patients than in patients without NAFLD. These findings suggest that patients with NAFLD should be screened for CKD and patients with CKD and metabolic syndrome should be screened for NAFLD. Patients with NAFLD and CKD should be treated and followed up by a multidisciplinary team that involves specialists in hepatology, nephrology, diabetes, and cardiology.

A brief review on the rising incidence of chronic kidney diseases and non-alcoholic fatty liver disease

Chronic kidney diseases (CKDs) are the most common forms of kidney disease all around the world. The incidence of CKD is rising, which is mainly driven by population aging as well as by a global rise in hypertension, metabolic syndrome, and metabolic risk factors, particularly obesity and type-2 diabetes. The high mortality, morbidity of CKD, and the health care costs of the renal replacement therapy have led investigators to seek recent and potentially modifiable risk factors such as non-alcoholic fatty liver disease (NAFLD). NAFLD is the hepatic manifestation of metabolic syndrome and the most common cause of chronic liver disease. It incorporates a spectrum of liver diseases ranging from simple steatosis to steatohepatitis, liver cirrhosis, and hepatocellular carcinoma. On the basis of recent publications, the prevalence of CKD is significantly increased among patients with NAFLD, and the prevalence of NAFLD is also higher in CKD patients than in patients without NAFLD. These findings suggest that patients with NAFLD should be screened for CKD and patients with CKD and metabolic syndrome should be screened for NAFLD. Patients with NAFLD and CKD should be treated and followed up by a multidisciplinary team that involves specialists in hepatology, nephrology, diabetes, and cardiology.

A feasibility study on the determination of 90Sr food-chain transfer using stable strontium as a surrogate and neutron activation analysis

We evaluated the applicability of neutron activation analysis for investigating the potential mobility of ⁹⁰Sr in a pasture area in Hungary. To measure strontium concentrations, we made use of the ⁸⁴Sr(n,γ)⁸⁵Sr radiative capture reaction using neutron activation analysis and performed gamma spectroscopy using Compton-suppression techniques on the resulting 514.0 keV gamma ray. Our values for soil-to-plant transfer factors value of 1.6 (2.2) kg kg^-1 were in agreement with recommended values from the ICRP and IAEA, as well as similar studies performed by independent researchers. Our values for plant-to-animal transfer coefficients and concentration ratios varied from suggested values by several orders of magnitude to agreement with other values. Based on our results the utilized transfer of stable strontium could not be regarded as a convenient substitute to help clarify the long-term transfer of radioactive strontium in the environment, because short term dosing was applied. Neutron activation analysis provides a unique niche as a technique with very little chemical processing and short sample analysis times.

TRITIUM, HYDROGEN AND OXYGEN ISOTOPE COMPOSITIONS IN MONTHLY PRECIPITATION SAMPLES COLLECTED AT TOKI, JAPAN

Monthly precipitation samples have been collected at Toki, Japan, from November 2013 to March 2017. In this report, selected data were analysed to identify the regional hydrogen and oxygen isotope compositions. Tritium (3H) concentration in the precipitation ranged from 0.10 to 0.61 Bq L-1 and higher 3H concentrations were observed in spring rather than in other seasons. This range was similar to values reported in Chiba City, Japan. 3H concentration and the ratio d-excess, and δD values were roughly clustered according to each separate season. These regional hydrogen and oxygen isotope compositions will be used for environmental assessments of effects of the deuterium plasma experiments of the large fusion test device.

ROLE OF METEOROLOGY AND LITHOLOGY IN THE TEMPORAL VARIATION OF THE OUTDOOR RADON LEVEL

The outdoor radon concentration was monitored together with the meteorological parameters at two contrasting complex topographies: sub-Alpine basin (SA) and sub-Mediterranean valley (SM) in winter (December 2017-February 2018) and summer (June-August 2018). The time series for each site and each season are evaluated in three different ways: (i) clear-sky and cloudy condition together, (ii) clear-sky conditions only (cloud cover <20%) and (iii) cloudy condition only (cloud cover >20%), and compared to the expected atmospheric boundary layer (ABL) 'mixing volume' caused by meteorological changes. The results have confirmed the sensitivity of diurnal and seasonal radon concentration to the expected ABL 'mixing volume' at the two selected sites. The relationship is more pronounced in calm clear-sky conditions. Cloudy conditions are associated with fast weather changes, when the ABL is well mixed and hourly mean radon concentrations do not follow the typical diurnal trend.

Stress Response and Virulence Potential Modulating Effect of Peppermint Essential Oil in Campylobacter jejuni

Campylobacter jejuni is one of the most common food-borne bacteria that causes gastrointestinal symptoms. In the present study we have investigated the molecular basis of the anti-Campylobacter effect of peppermint essential oil (PEO), one of the oldest EO used to treat gastrointestinal diseases. Transcriptomic, quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and proteomic, two-dimensional polyacryl amid gel electrophoresis (2D-PAGE) methods have revealed that, in the presence of a sublethal concentration of PEO, the expression of several virulence-associated genes was decreased (cheY 0.84x; flhB 0.79x; flgE 0.205x; cadF 0.08x; wlaB 0.89x; porA 0.25x; cbf2 4.3x) while impaired motility was revealed with a functional analysis. Scanning electron micrographs of the exposed cells showed that, unlike in the presence of other stresses, the originally curved C. jejuni cells straightened upon PEO exposure. Gaining insight into the molecular background of this stress response, we have revealed that in the presence of PEO C. jejuni dominantly exerts a general stress response that elevates the expression of general stress genes like dnaK, groEL, groES (10.41x, 3.63x, and 4.77x). The most important genes dps, sodB, and katA involved in oxidative stress responses showed however moderate transcriptional elevations (1,58x, 1,55x, and 1,85x).

Arterial stiffness may predict renal and cardiovascular prognosis in autosomal-dominant polycystic kidney disease

Background and aims

Autosomal-dominant polycystic kidney disease (ADPKD) is one of the most common causes of end-stage renal disease (ESRD). The most important cause of death among ADPKD patients is cardiovascular (CV). The aim of this study was to examine the prognostic significance of arterial stiffness on CV and renal outcomes in ADPKD.

Methods

A total of 55 patients with ADPKD were examined. Pulse wave velocity was determined and stiffness index (SIDVP) was calculated. Combined primary endpoints (CV and renal) were major CV events (myocardial infarction, stroke, and CV intervention) as CV endpoints, and attaining of ESRD or start of renal replacement therapy as renal endpoints. Secondary endpoints were CV or renal endpoints separately.

Results

The mean age of those 55 ADPKD patients was 45 ± 12 years, 21 patients were male. The average value of the SIDVP was 11.11 ± 2.22 m/s. The patients were divided into two groups by the cutoff value of 11 m/s of SIDVP and then outcomes were analyzed. In the higher arterial stiffness group (SIDVP > 11 m/s), occurrence of combined primary endpoint (CV and renal) was significantly higher than in the group with more elastic arteries (p = 0.033). A statistically significant difference was found in the renal endpoints (p = 0.018), but not in the CV endpoints (p = 0.952) between the two groups.

Conclusions

Increased arterial stiffness predicts the onset of ESRD in ADPDK. Assessment of SIDVP appears to be a useful method for estimating the renal and CV prognosis in ADPKD.

Determination of cesium transfer factors by instrumental neutron activation analysis

Food-chain models are used to predict radionuclide ingestion after fallout deposition. These models include those transfer processes (soil-to-plant transfer factor(s) [TF], plant-to-animal transfer coefficient(s) [TC] and concentration ratio [CR]) that are likely to be important for radiological assessment. The range of variability for transfer factors for the same plant groups is great, about 4-5 orders of magnitude, which limits their applicability. A better way to determine the best estimate the factors for radiocaesium and other important radionuclides is if the site-specific data are available. Soil, plant and animal samples were collected from a pasture area in Hungary during the vegetation period in 2016. Stable ¹³³Cs concentration was analysed by comparative method with neutron activation analysis (NAA). The comparator and the samples were irradiated in thermal neutron flux 2.55 × 10¹² ncm^-2s^-1 for 2 h (soil) and 6 h (vegetation, animal samples) in the TRIGA Mark II research reactor at the Nuclear Engineering Teaching Laboratory. After an appropriate decay time (12 days) the samples were measured by gamma-spectrometry and analysed. The observed stable caesium TC_pm (0.48-0.53) and CR_pm (0.41-0.45) were very close to ¹³⁷Cs factors in the IAEA 2009 Report of 0.49 and 0.54, respectively. This methodology is particularly suitable for the simultaneous study of natural caesium in ecosystem compartments. Consequently, the transfer of stable caesium in a pasture field may be regarded as a useful analogy in predicting the long-term changes of ¹³⁷Cs affected by site-specific environmental factors.

Advantages of the Microwave Tool in Organophosphorus Syntheses

The microwave (MW) technique has become an important tool also in the organophosphorus field of organic chemistry. On the one hand, otherwise reluctant reactions, such as the esterification of P-acids, may be enhanced by the effect of MW, while on the other hand, catalysts may be omitted, or catalyst systems may be simplified on MW irradiation. This later group includes the Kabachnik–Fields reactions, alkylation of active methylene-containing compounds, O-alkylations, deoxygenations, as well as the Hirao reaction. It is also the purpose of this review to elucidate the scope and limitations of the MW tool, to interpret the MW effects, and to model the distribution of local overheatings and their beneficial effect.

1 Introduction

2 The Esterification of Phosphinic Acids

2.1 Synthetic Results

2.2 Scope and Limitation of the Application of MWs

2.3 Modelling the Distribution of the Local Overheatings and Predicting­ Their Effect

3 The Simplification of Catalytic Systems

3.1 Replacement of the Catalyst by MW Irradiation

3.1.1 The Kabachnik–Fields Reaction

3.1.2 Solid–Liquid Phase Alkylation of Active Methylene-Containing Compounds

3.1.3 Solid–Liquid Phase Alkylation of Phosphinic Acids

3.1.4 The Deoxygenation of Phosphine Oxides

3.2 The Hirao Reaction without Added P-Ligands

4 Conclusions

Radiological and material characterization of high volume fly ash concrete

The main goal of research presented in this paper was the material and radiological characterization of high volume fly ash concrete (HVFAC) in terms of determination of natural radionuclide content and radon emanation and exhalation coefficients. All concrete samples were made with a fly ash content between 50% and 70% of the total amount of cementitious materials from one coal burning power plant in Serbia. Physical (fresh and hardened concrete density) and mechanical properties (compressive strength, splitting tensile strength and modulus of elasticity) of concrete were tested. The radionuclide content (²²⁶Ra, ²³²Th and ⁴⁰K) and radon massic exhalation of HVFAC samples were determined using gamma spectrometry. Determination of massic exhalation rates of HVFAC and its components using radon accumulation chamber techniques combined with a radon monitor was performed. The results show a beneficial effect of pozzolanic activity since the increase in fly ash content resulted in an increase in compressive strength of HVFAC by approximately 20% for the same mass of cement used in the mixtures. On the basis of the obtained radionuclide content of concrete components the I -indices of different HVFAC samples were calculated and compared with measured values (0.27-0.32), which were significantly below the recommended 1.0 index value. The prediction was relatively close to the measured values as the ratio between the calculated and measured I-index ranged between 0.89 and 1.14. Collected results of mechanical and radiological properties and performed calculations clearly prove that all 10 designed concretes with a certain type of fly ash are suitable for structural and non-structural applications both from a material and radiological point of view.

Objective decision making between conventional and oncoplastic breast-conserving surgery or mastectomy: An aesthetic and functional prospective cohort study

BACKGROUND

Breast-conserving surgery (BCS) is considered the standard treatment for early-stage breast cancer. However, fair to poor cosmetic outcomes following conventional BCS have been observed in as many as one-third of cases. The aim of this study was to determine the critical tumor-to-breast volume ratio for each quadrant of the breast beyond which conventional BCS would no longer offer acceptable cosmetic and functional results or satisfactory quality of life for the patient.

METHODS

A prospective cohort study was performed between December 2011 and December 2013 involving 350 patients younger than 70 years with early-stage unifocal (T ≤ 30 mm) breast cancer who underwent wide excision and axillary sentinel lymph node biopsy followed by whole-breast irradiation. Using validated panels and software (the Breast Cancer Treatment Outcome Scale [BCTOS], EORTC Cancer Quality of Life Questionnaire number C30-BR23, and Breast Cancer Conservative Treatment - cosmetic results [BCCT.core] software), quality of life and aesthetic and functional parameters and their changes in correlation to the percentage of breast volume excised were statistically analyzed.

RESULTS

The maximum percentages of breast volume that were resectable by conventional BCS without resulting in unacceptable aesthetic and functional outcomes or decreased quality of life were 18-19% in the upper-outer quadrant (p < 0.0001), 14-15% in the lower-outer quadrant (p < 0.0001), 8-9% in the upper-inner quadrant (p < 0.0001), and 9-10% in the lower-inner quadrant (p < 0.0001).

CONCLUSION

Aided by the calculated cut-off values for each breast quadrant, breast surgeons might render more objective decisions regarding performing conventional BCS, using oncoplastic techniques or choosing mastectomy with immediate reconstruction.

Does breast screening offer a survival benefit? A retrospective comparative study of oncological outcomes of screen-detected and symptomatic early stage breast cancer cases

INTRODUCTION

Mammography screening reduces breast cancer mortality by up to 32%. However, some recent studies have questioned the impact of non-palpable breast cancer detection on mortality reduction. The aim of this study was to analyse the clinicopathological and long-term follow-up data of early stage screened and symptomatic breast cancer patients.

PATIENTS AND METHOD

The institutional prospectively led database was systematically analysed for breast cancer cases diagnosed via the mammography screening program from 2002 to 2009. As a control group, symptomatic early stage breast cancer patients were collected randomly from the same database and matched for age and follow-up period. All medical records were reviewed retrospectively.

RESULTS

Data from 298 breast cancer patients were collected from 47,718 mammography screenings. In addition, 331 symptomatic breast cancer patients were randomly selected. The screened group presented a significantly lower median tumour size (P < 0.00001). The incidence of negative regional lymph nodes was significantly higher in the screened group (P < 0.0006). The incidence of chemotherapy was 17% higher in the symptomatic group (P = 4*10^-5). At the median follow-up of 65 and 80 months, the screened group did not exhibit better overall (P = 0.717) or disease-free survival (P = 0.081) compared to the symptomatic group.

CONCLUSION

Our results do not suggest that mammography screening does not reduce breast cancer mortality but the mammography screening did not bring any significant improvement in patient overall or disease-free survival for the early stage breast cancer patients compared to the symptomatic group. The drawback of symptomatic early stage tumours compared to non-palpable tumours could be equalized by modern multimodality oncology treatments.

New study on the correlation between carbon dioxide concentration in the environment and radon monitor devices

The influence of high geogenic carbon dioxide concentrations on monitoring devices might present a significant challenge to the measurement of radon concentrations in environments with a high level of carbon dioxide concentration such as volcano sites, mofettes, caves, etc. In this study, the influence of carbon dioxide concentration on several different types of radon monitor devices - including Alpha Spectrometry (Sarad RTM 2200, EQF 3220, RAD7), Ionizing Chamber (AlphaGUARD PQ2000 PRO) and Active Cell (Active scintillation cell, Pylon 300A) - was examined to represent new aspects of radon measuring in environments with carbon dioxide. In light of the results, all measuring devices were exposed to variable conditions affected by carbon dioxide concentration, except for the AlphaGUARD, which was kept in a steady state throughout the experiment. It was observed that alpha spectroscopy devices were affected by carbon dioxide, since measured radon concentrations decreased in the presence of 70% and 90% carbon dioxide concentrations by 26.5 ± 2% and 14.5 ± 2.5% for EQF 3220, and 32 ± 2% and 35.5 ± 2% for RTM 2200. However, the ionizing chamber instrument was unaffected by changes in carbon dioxide concentration. It was determined that the RAD7 performed relatively inefficiently in the presence of carbon dioxide concentrations higher than 67% by an overall efficiency factor of approximately 0.52, confirming that it is not an admissible radon monitor instrument in environments with high carbon dioxide concentrations.

Preliminary study of the applicability of the thin gap method on alpha emitters

The thin gap method as an in-situ radiotracer technique is widely used. This study investigated the applicability of alpha emitters. PIPS and CsI alpha spectrometers were applied in a thin gap cell. A suitable (210)Po source was prepared by spontaneous deposition, Mylar foil was used to simulate water. A maximum intensity decrement of 7% within 25 μm was observed. Even though this method is suitable for the study of surface phenomena, further investigation is necessary e.g. into water and heat sensitivity.

Preparation and characterisation of ceramic-based thoron sources for thoron calibration chamber

The aim of this study is to explore the correlations between the properties of the source's material and the thoron flux produced. This means a complex procedure that involves morphological characterisation (the determination of specific surface area and pore size distribution) and thoron emanation and exhalation measurements as well. In this work, the preparation of 27 thoron sources has been carried out. Three types of ceramics with different morphological properties were used as a matrix material with three different thorium contents. Spheres were formed from the dollop, and they were fired at different temperatures (200, 600 and 900°C). The phase analysis of the samples was performed by powder X-ray diffraction. The pore size distribution was determined by mercury penetration. The thoron emanation was measured using an accumulation chamber; the measured thoron emanation coefficients were from 0.34 ± 0.03 to 7.69 ± 0.13 %. Based on the results, the preparation parameters of the thoron source optimised for the calibration procedure have been given.

Radionuclide content of NORM by-products originating from the coal-fired power plant in Oroszlány (Hungary)

At the Thermal Power Plant in Oroszlány (Hungary), a huge amount of by-products have been produced since 1961. In this survey, coal and other by-products were examined (fly ash, bottom ash, fluidised bed bottom ash, gypsum and slurry-type ash). The natural isotopes were determined using an HPGe detector. It was found that the radionuclide content of coal was significantly lower ((226)Ra = 45.3±6.3, (232)Th = 26.3±5.7 and (40)K = 210±21 Bq kg(-1)) than that in the case of ashes other than the fluidised type. The average values of the bottom ash-deposited in the largest quantities-were three times higher than those for coal ((226)Ra = 144±18, (232)Th = 84.3±14 and (40)K = 260±25 Bq kg(-1)). In the case of fractionised bottom ash, the radionuclide content of <0.1 mm was 45 % higher than that of >1.6 mm and the massic radon exhalation of <0.1 mm was approximately four times higher than that above this range.

Elevated vascular level of ortho-tyrosine contributes to the impairment of insulin-induced arterial relaxation

Previous studies have shown that in diabetes mellitus, insulin-induced relaxation of arteries is impaired and the level of ortho-tyrosine (o-Tyr), an oxidized amino acid is increased. Thus, we hypothesized that elevated vascular level of o-Tyr contributes to the impairment of insulin-induced vascular relaxation. Rats were fed with o-Tyr for 4 weeks. Insulin-induced vasomotor responses of isolated femoral artery were studied using wire myography. Vascular o-Tyr content was measured by HPLC, whereas immunoblot analyses were preformed to detect eNOS phosphorylation. Sustained oral supplementation of rats with o-Tyr increased the content of o-Tyr in the arterial wall and significantly reduced the relaxations to insulin. Sustained supplementation of cultured endothelial cells with o-Tyr increased the incorporation of o-Tyr and mitigated eNOS Ser (1 177) phosphorylation to insulin. Increasing arterial wall o-Tyr level attenuates insulin-induced relaxation - at least in part - by decreasing eNOS activation. Elevated level of o-Tyr could be an underlying mechanism for vasomotor dysfunction in diabetes mellitus.

Preliminary results of indoor radon survey in V4 countries

The measurements of radon activity concentration carried out in residential houses of V4 countries (Hungary, Poland and Slovakia) show that radon levels in these countries considerably exceed the world average. Therefore, the new radon data and statistical analysis are required from these four countries. Each partner chose a region in their own country, where radon concentration in residential buildings was expected to be higher. The results of the survey carried out in the period from March 2012 to May 2012 show that radon concentrations are <200 Bq m(-3) in ∼87% of cases. However, dwellings with radon concentration ∼800 Bq m(-3) were found in Poland and Slovakia. It was also found that the distribution of radon frequency follows that of houses according to the year of their construction.

Calibration of CR-39-based thoron progeny device

Radon isotopes and their progenies have proven significant role in respiratory tumour formation. In most cases, the radiological effect of one of the radon isotopes (thoron) and its progenies has been neglected together with its measurement technique; however, latest surveys proved that thoron's existence is expectable in flats and in workplace in Europe. Detectors based on different track detector measurement technologies have recently spread for measuring thoron progenies; however, the calibration is not yet completely elaborated. This study deals with the calibration of the track detector measurement method suitable for measuring thoron progenies using different devices with measurement techniques capable of measuring several progenies (Pylon AB5 and WLx, Sarad EQF 3220). The calibration factor values related to the thoron progeny monitors, the measurement uncertainty, reproducibility and other parameters were found using the calibration chamber. In the future, the effects of the different parameters (aerosol distribution, etc.) will be determined.