[On integration of the iodine deficiency elimination and salt reduction programs].

Excessive salt intake is a risk factor for noncommunicable diseases, but salt iodization is the most effective method of population-based prevention of iodine deficiency. Therefore, an assessment of dietary iodine intake from the use of iodized salt in the food industry and potential reductions in salt intake is needed. Objective. To assess the feasibility of integrating iodine deficiency prevention and salt reduction programmes among the adult population in the Republic of Belarus. Material and methods. Using the thiocyanate-nitrite method, the determination of iodine in various types of foods was carried out. Taking into account the actual dietary intake, estimated using the frequency method among 583 respondents over 18 years old, living in Minsk, from various socioeconomic groups, alimentary iodine intake was assessed at different levels of salt use in households. The level of iodine sufficiency was additionally estimated on the base of urinary excretion data obtained by the cerium-arsenite spectrophotometric method in 100 healthy adults over the age of 18 living in Minsk (65 women and 35 men). Results. As part of the legal framework for the use of iodized salt in food production, there has been a steady increase in iodine levels in the target products (bakery and meat products to 42.0 and 133.3 µg/100 g respectively). The content of the discussed micronutrient in the diet of the adult population has raised at least 1.9-fold in recent decades, to 237.3 µg/day in the most realistic consumption model. The main source of iodine among this subpopulation is commercially produced foods with iodized salt, which forms 30-58% of the alimentary iodine exposure. Consumption of salt in Belarus averages 10.6 g per day, which poses a risk of developing noncommunicable diseases and necessitates programmes to reduce the level of salt in the diet. Modeling of scenarios with reduction of salt use in households in accordance with the recommendations of the World Health Organization (WHO) shows that the main contribution to dietary iodine exposure will be made by bread products (38%), about 1/3 will be formed by table salt, the value of non-target fortified products (milk and eggs) will increase (up to 21%). The contribution of table iodized salt to the dietary iodine exposure reaches 43% at actual consumption levels and will decrease to 18% if it is reduced to the WHO recommended values. The median of ioduria among those surveyed is 136.8 µg/l, indicating adequate iodine supply. Conclusion. In implementing joint programs on prevention of iodine deficiency and cardiovascular diseases associated with excessive salt intake, it is necessary to consider national conditions - mandatory use of iodized salt in food industry, its level of fortification, content of this micronutrient in foodstuffs and structure of their consumption among certain population groups.

DYNAMICS OF INDICES OF OXIDATIVE STRESS IN PATIENTS WITH THYROID GLAND SURGERY DEPENDING ON ITS FUNCTIONAL ACTIVITY.

Hormonal dysfunction of the thyroid gland causes disorder of all kinds of metabolism. Both hypothyroidism, and hyperthyroidism are the causes of imbalance in prooxidant-antioxidant system with the development of pathological process named "oxidative stress". Objective - study of oxidative stress in patients who underwent thyroid gland operation depending on its functional activity and the presence of autoimmune thyroiditis. The intensity of lipid peroxidation was examined by concentration of diene conjugates and malondialdehyde, and the activity of antioxidant system by the level of catalase, superoxide dismutase, glutathione peroxidase, glutathione reductase of red blood cells. It was established that the activity level of the lipid peroxidation system and the activity of antioxidant defense enzymes have their specific characteristics depending on the various functional states of the thyroid gland, as well as on the presence or absence of autoimmune component in the structure of thyroid pathology. All changes occurring in patients with this pathology accompanied by hormonal imbalance and autoimmune thyroiditis, lead to development of chronic nonspecific metabolic endogenous intoxication.

First experiments with the negative ion source NIO1.

Neutral Beam Injectors (NBIs), which need to be strongly optimized in the perspective of DEMO reactor, request a thorough understanding of the negative ion source used and of the multi-beamlet optics. A relatively compact radio frequency (rf) ion source, named NIO1 (Negative Ion Optimization 1), with 9 beam apertures for a total H(-) current of 130 mA, 60 kV acceleration voltage, was installed at Consorzio RFX, including a high voltage deck and an X-ray shield, to provide a test bench for source optimizations for activities in support to the ITER NBI test facility. NIO1 status and plasma experiments both with air and with hydrogen as filling gas are described. Transition from a weak plasma to an inductively coupled plasma is clearly evident for the former gas and may be triggered by rising the rf power (over 0.5 kW) at low pressure (equal or below 2 Pa). Transition in hydrogen plasma requires more rf power (over 1.5 kW).

[The problem of iodine deficiency and its solution in the republic of Belarus].

The problem of iodine deficiency is relevant to the Republic of Belarus. It's confirmed by virtually commonly found geophysical iodine deficiency in soils and waters. Data on iodine deficiency initiated the development of a state strategy for the elimination of iodine deficiency in the population. This strategy determined the mandatory use of iodized salt only in the country in the food industry and catering as the main event for the elimination of iodine deficiency. The aim of this work was a comprehensive evaluation of the results of the implementation of the strategy for elimination of iodine deficiency among the population of the Republic of Belarus. Medical monitoring of the assessment of the efficacy showed the decrease in the incidence of simple non-toxic goiter in adolescents from 1215,23 per 100,000 population in 1998 to 341,25 in 2013 (3.6 times), and indices ofprimary morbidity rate in children fell by 2.9 times. Over the period from 1998 primary morbidity rate of simple nontoxic goiter decreased significantly in adults from 379.9 to 31,71 people per 100,000 of the population in 2013 respectively (almost 12 times). Data of the assessment of ioduria in Belarus indicate that 89.2% of children enrolled in the study have iodine excretion of more than 100 pg/L. Thus, in the Republic of Belarus there was achieved the level of an adequate intake of iodine with foodstuffs. This model ofprevention of iodine deficiency, as well as the traditional approach based on the adoption of the law, is a versatile and cost-effective mode.

Installation of a versatile multiaperture negative ion source.

Neutral Beam Injectors (NBI), which need to be strongly optimized in the perspective of DEMO reactor, request a thorough understanding of the negative ion source used and of the multi-beamlet optics. A relatively compact RF ion source, named NIO1 (Negative Ion Optimization 1), with 9 beam apertures for a total H(-) current of 130 mA, 60 kV acceleration voltage, is being installed at Padua, in Consorzio RFX, to provide a test bench for source optimizations in the framework of the accompanying activities in support to the ITER NBI test facility. NIO1 construction and status of the overall installation, including a high voltage deck and an optical cavity ring down spectrometer are here summarized and reported. Plasma and low voltage beam operations are discussed. Development of a sampling beam calorimeter (with small sampling holes, and a segmented cooling circuit) is also discussed.

Development of a versatile multiaperture negative ion source.

A 60 kV ion source (9 beamlets of 15 mA each of H(-)) and plasma generators are being developed at Consorzio RFX and INFN-LNL, for their versatility in experimental campaigns and for training. Unlike most experimental sources, the design aimed at continuous operation. Magnetic configuration can achieve a minimum ∣B∣ trap, smoothly merged with the extraction filter. Modular design allows for quick substitution and upgrading of parts such as the extraction and postacceleration grids or the electrodes in contact with plasma. Experiments with a radio frequency plasma generator and Faraday cage inside the plasma are also described.

Models of radiofrequency coupling for negative ion sources.

Radiofrequency heating for ICP (inductively coupled plasma) ion sources depends on the source operating pressure, the presence or absence of a Faraday shield, the driver coil geometry, the frequency used, and the magnetic field configuration: in negative ion source a magnetic filter seems necessary for H(-) survival. The result of single particle simulations showing the possibility of electron acceleration in the preglow regime and for reasonable driver chamber radius (15 cm) is reported, also as a function of the static external magnetic field. An effective plasma conductivity, depending not only from electron density, temperature, and rf field but also on static magnetic field is here presented and compared to previous models. Use of this conductivity and of multiphysics tools for a plasma transport and heating model is shown and discussed for a small source.

Design of a versatile multiaperture negative ion source.

Negative ion sources are a key component of the neutral beam injector to be installed in the International Thermonuclear Experimental Reactor. At present research and development activities address several important issues related to beam extraction, optics, and optimization. Together with the design of real size devices and the accumulation of atomic cross section databases, a relatively small negative ion source [130 mA of H(-) at 60 kV, named Negative Ion Optimization phase 1 (NIO1)] is under construction at Consorzio RFX to contribute to benchmark numerical simulation tools and to test components, such as emittance scanners, beam dumps, and cesium ovens. NIO1 design, magnet configuration, and rf coupling simulations are described.

ITEP MEVVA ion beam for rhenium silicide production.

The rhenium silicides are very attractive materials for semiconductor industry. In the Institute for Theoretical and Experimental Physics (ITEP) at the ion source test bench the research program of rhenium silicide production by ion beam implantation are going on. The investigation of silicon wafer after implantation of rhenium ion beam with different energy and with different total dose were carried out by secondary ions mass spectrometry, energy-dispersive x-ray microanalysis, and x-ray diffraction analysis. The first promising results of rhenium silicide film production by high intensity ion beam implantation are presented.

New measurement of the K+-->pi+ nunu branching ratio.

Three events for the decay K+-->pi+ nunu have been observed in the pion momentum region below the K+-->pi+pi0 peak, 140 < Ppi < 199 MeV/c, with an estimated background of 0.93+/-0.17(stat.) -0.24+0.32(syst.) events. Combining this observation with previously reported results yields a branching ratio of B(K+-->pi+ nunu) = (1.73(-1.05)+1.15) x 10(-10) consistent with the standard model prediction.

Refractory rf ovens and sputter probes for electron cyclotron resonance ion source.

Beams from electron cyclotron resonance ion source (ECRIS) with radio frequency ovens for refractory material (using a Mo coil) were recently demonstrated; results for Ti and V are here discussed, with temperature T(s) > or = 2300 K stably maintained and extracted current of about 1000 nA for V(8+) and V(9+). The status of sputter probes is also reported, and the reason why trapping efficiency may be lower than in the oven case are investigated. The simple tubular probe concept show typical currents of Sn(18+) about 250 nA, for the most abundant isotopes, but an operating pressure of about 300 microPa may be required. Some preliminary experiments were performed with Penning probes, showing that transmission of Sn or Pr from Penning cathode to ECRIS plasma is limited. Placement of tin onto anticathode and use of collimator between Penning and ECRIS are also discussed.

Bernas ion source discharge simulation.

As the technology and applications continue to grow up, the development of plasma and ion sources with clearly specified characteristic is required. Therefore comprehensive numerical studies at the project stage are the key point for ion implantation source manufacturing (especially for low energy implantation). Recently the most commonly encountered numerical approach is the Monte Carlo particle-in-cell (MCPIC) method also known as particle-in-cell method with Monte Carlo collisions. In ITEP the 2D3V numerical code PICSIS-2D realizing MCPIC method was developed in the framework of the joint research program. We present first results of the simulation for several materials interested in semiconductors. These results are compared with experimental data obtained at the ITEP ion source test bench.

Status of ITEP decaborane ion source program.

The joint research and development program is continued to develop steady-state ion source of decaborane beam for ion implantation industry. Both Freeman and Bernas ion sources for decaborane ion beam generation were investigated. Decaborane negative ion beam as well as positive ion beam were generated and delivered to the output of mass separator. Experimental results obtained in ITEP are presented.

Ion sources for energy extremes of ion implantation.

For the past four years a joint research and development effort designed to develop steady state, intense ion sources has been in progress with the ultimate goal to develop ion sources and techniques that meet the two energy extreme range needs of meV and hundreads of eV ion implanters. This endeavor has already resulted in record steady state output currents of high charge state of antimony and phosphorus ions: P(2+) [8.6 pmA (particle milliampere)], P(3+) (1.9 pmA), and P(4+) (0.12 pmA) and 16.2, 7.6, 3.3, and 2.2 pmA of Sb(3+)Sb(4+), Sb(5+), and Sb(6+) respectively. For low energy ion implantation, our efforts involve molecular ions and a novel plasmaless/gasless deceleration method. To date, 1 emA (electrical milliampere) of positive decaborane ions was extracted at 10 keV and smaller currents of negative decaborane ions were also extracted. Additionally, boron current fraction of over 70% was extracted from a Bernas-Calutron ion source, which represents a factor of 3.5 improvement over currently employed ion sources.

Improved measurement of the K+-->pi+nunu; branching ratio.

An additional event near the upper kinematic limit for K+-->pi(+)nunu; has been observed by experiment E949 at Brookhaven National Laboratory. Combining previously reported and new data, the branching ratio is B(K+-->pi(+)nunu;)=(1.47(+1.30)(-0.89))x10(-10) based on three events observed in the pion momentum region 211

Iodine nutrition and the risk from radioactive iodine: a workshop report in the chernobyl long-term follow-up study.

The major fallout of radionuclides from the nuclear power station accident at Chernobyl on 26 April, 1986, occurred in regions of Ukraine and Belarus that are believed to be moderately deficient in dietary iodine. On 17 November, 2000, in conjunction with the Ukraine-Belarus-USA study of developing thyroid disease in a cohort of individuals exposed as children, a workshop was held to review what is known about iodine nutrition in the region, how this might influence the risk of thyroid tumor formation from radioiodine, and whether and how iodine nutrition should be monitored in this long-term project. This report is a summary of the workshop proceedings. Although no precise information about iodine intake in 1986 was found, the prevalence of mild goiter in the region's children suggested iodine deficiency and urinary iodine measurements begun in 1990 indicated that mild to moderate deficiency existed. Increased thyroid iodine uptake and increased thyroid size in 1986 resulting from iodine deficiency would have had counteracting influence on the thyroid radiation dose and knowledge of these parameters is required for dose reconstruction. More problematic is the possible role of iodine deficiency in the years following the accident. Theoretically, the resulting increase in thyroid cellular activity might increase the risk of tumorigenesis but experimental or clinical evidence supporting this hypothesis is meager or absent. Despite this limitation it was considered important to monitor iodine nutrition in the cohort subjects in relation to their place of residence and over time. Methods to accomplish this were discussed.

Effects of nitric oxide donors on Ca2+-dependent [14C]GABA release from brain synaptosomes: the role of SH-groups.

Nitric oxide (NO) modulates processes of synaptic transmission at pre- and postsynaptic levels. In the present work we studied the mechanisms of action of NO on [gamma-14C]amino-n-butyric acid ([14C]GABA) release in rat cortical synaptosomes. NO donors--S-nitroso-L-cysteine and hydroxylamine (but not sodium nitroprusside)--inhibited the neurotransmitter efflux in a concentration range from 10 microM to 1 mM. Nitrosocysteine completely and selectively suppressed the Ca2+-dependent (vesicular) [14C]GABA release, while not affecting the Ca2+-independent component of the [14C]GABA transport. The influence of NO donors was not related to activation of guanylyl cyclase, since the membrane-permeable cGMP analog dibutyryl-cGMP did not mimic and the guanylyl cyclase inhibitor methylene blue did not change the NO effects. In contrast, the membrane-permeable SH-reagent N-ethylmaleimide (NEM) resembled the effects of NO donors on the Ca2+-dependent [14C]GABA release. The degree of inhibition of the release by nitrosocysteine, hydroxylamine, and NEM correlated with their ability to oxidize intra-synaptosomal SH-groups. These data suggest that synaptosomal sulfhydryl groups are the target for NO action at the presynaptic level. The NO-induced oxidation of thiols may be involved in physiological and, especially, pathological effects of nitric oxide in the central nervous system.

Iodine deficiency in Belarusian children as a possible factor stimulating the irradiation of the thyroid gland during the Chernobyl catastrophe.

Ten years after the Chernobyl nuclear plant catastrophe more than 500 children in Belarus are suffering from thyroid cancer. The major cause of the high incidence of thyroid cancer in children under 15 years of age appears to be contamination resulting from that catastrophe, mainly with isotopes of radioactive iodine. Another important factor may be iodine deficiency in the environment. A countrywide program for investigation of goiter prevalence and iodine deficiency has been established in the Republic of Belarus with the assistance of the European World Health Organization office. The program will oversee the examination of 11,000 children and adolescents 6 to 18 years of age from 30 schools in urban and rural areas. The results obtained in a group of 824 children and adolescents (the pilot phase) are typical for significant iodine deficiency and moderate goiter endemism. It is clear that the present situation does not completely reflect the situation that existed at the time of the Chernobyl catastrophe. However, data from epidemiologic studies conducted many years before the accident showed high goiter prevalence in the contaminated areas, indicating that the prevalence of iodine deficiency at the time of the catastrophe was similar to the present one or even greater. Such an assumption could lead to a better understanding of the thyroid pathologies that have been observed.

Early experimental studies on hemoperfusion as a treatment modality for acute radiation disease.

First results of the studies on hemoperfusion therapy of acute radiation disease that were conducted in Kiev in 1976 are presented. In these studies, 69 mongrel dogs were exposed to irradiation at a dose of 525 rad (5.25 Gy). It was proved that hemoperfusion through uncoated synthetic activated carbons led to a noticeable increase in their survival rate, from 3.2% in the control group (n = 31) to 68.4% and 62.4% for the dogs that received extracorporeal treatment at 2 h (n = 19) and 24 h (n = 19) after irradiation, respectively.

Chromosome aberrations in human lymphocytes apparently induced by Chernobyl fallout.

Sixteen people (15 from Byelorussia, one from Kiev) possibly exposed to radioactivity released by the Chernobyl accident were investigated for chromosome aberrations induced in lymphocytes. Statistically significant increases of the yield of dicentric chromosomes were observed in five people.