Development of X-ray fluorescence technique for the uranium determination in Mongolian coal, coal ash, and phosphate ore

The results of the determination of uranium in Mongolian brown coal, coal ash, phosphate rock, and technological samples by X-ray fluorescence (XRF) spectrometry are presented. Technological samples were produced from phosphates by chemical treatment. Powder geological samples and Certified Reference Materials (CRMs) were pressed as tablets. For chosen conditions of the sample preparation procedure analytical figures of merit were carefully studied, as exemplified by the rock and uranium ore Reference Materials. The variance of the total uncertainty is 2 % for uranium in the analyzed samples, and one is 7 % in the rock CRMs. The estimated values of the uranium detection limit for the CRMs are within the interval from 1 to 3 ppm. For the correction of the matrix effects the background standard method was used. Values of the uranium contents in the studied samples vary within the interval from 3.0 to 35.0 ppm. The comparison of the wavelength dispersive (WD) XRF results with the energy dispersive (ED) XRF results and the neutron activation analysis (NAA) was performed. It is demonstrated that the WDXRF have satisfactorily agreed with the EDXRF results and the NAA within the limits of the uncertainty. It is shown that the values of the relative discrepancies between the WDXRF and EDXRF results are in the range of 2.0-18.0 %, and between the WDXRF and the NAA results are in the range of 2.0-20.0 %. These values are less than 30 %, yielding the third category of the precision of the mineral raw material analysis

PHYLOGENETIC DIVERSITY OF SOME SMALL MAMMALS FROM SCIURUDAE FAMILY IN MONGOLIA

The squirrel family, Sciuridae, is one of the largest and widespread, ecologically common families of mammals. Due to the conspicuousness of this small mammal group with a big population, insufficient knowledge exists about its phylogenetic relationships. In this study, we identified 14 DNA sequences of mitochondrial cytochrome oxidase I gene in 6 species of Sciuridae and these sequences were compared with corresponding published COI gene sequences of the same species in Eurasia and determined their phylogenetic relationships by Neighbor-joining method

PHYLOGENETIC DIVERSITY OF SOME SMALL MAMMALS FROM <em>SCIURUDAE</em> FAMILY IN MONGOLIA

The squirrel family, Sciuridae, is one of the largest and widespread, ecologically common families of mammals. Due to the conspicuousness of this small mammal group with a big population, insufficient knowledge exists about its phylogenetic relationships. In this study, we identified 14 DNA sequences of mitochondrial cytochrome oxidase I gene in 6 species of Sciuridae and these sequences were compared with corresponding published COI gene sequences of the same species in Eurasia and determined their phylogenetic relationships by Neighbor-joining method

The study of correlation between Intellectual Impairment and Blood Lead Level among 6 to 8 years old Children in Ulaanbaatar

Background Lead poisoning is one of the major public health problem in developing countries. Lead is neurotoxic and young children are at particular high risk for exposure. According to previous research done in Mongolia in 2009, the average blood lead level (BLL) among children in Ulaanbaatar was 16.54±9.50 ug/dl, which is higher than the WHO's recommended level (&gt;=10 mg/dl).   Material and Methods We measured BLL in 300 children at 6 to 8 years old of age and administered the IQ test which standartized by the Mongolian Ministry of Health. We used LeadCare II Analyzer Kit apparatus to measure BLL in children from 8 selected primary schools in Ulaanbaatar. The relation between IQ and BLL estimated with the use multivariable linear and nonlinear mixed models, with quality of the home environment, and other potential confounders. SPSS 19.0 is used for statistical analysis.   Results The BLL is associated with IQ scores in children living in UB. BLL in children is increased from last parameter (mentioned above). We identified some potential confounders in UB such as air pollution and petrol station. They are significantly associated with BLL in Children.   Conclusion Due to high exposure of lead in Ulaanbaatar the LeadCare II analyzer kit can be used for screen purpose. Our government has to make strategy to reduce lead sources and medical students need to promote and educate environmental health education to citizens. Source of the lead exposure needs to be identified

Vitamin D supplements and prevention of tuberculosis infection and disease

BACKGROUND: Vitamin D metabolites support innate immune responses to Mycobacterium tuberculosis. METHODS: We randomly assigned children who had negative results for Mycobacterium tuberculosis infection, using the QuantiFERON-TB Gold In-tube assay (QFT), to receive a weekly oral dose of 14,000 IU vitamin D3 or placebo over 3 years. The primary outcome was the proportion of children having a positive QFT result at 3 years. Secondary outcomes included end-study vitamin D status and incidence of tuberculosis disease, acute respiratory infections and adverse events. RESULTS: 8851 participants underwent randomization (4418 to vitamin D, 4433 to placebo), of whom 95.6% had baseline serum 25-hydroxyvitamin D concentrations <20 ng/mL. Mean end-study 25-hydroxyvitamin D concentration in participants randomized to vitamin D vs. placebo was 31.0 vs. 10.7 ng/mL (95% CI for difference, 19.9 to 20.6 ng/mL), and 147 participants in the vitamin D group vs. 134 participants in the placebo group tested positive by QFT (adjusted risk ratio [aRR] 1.10, 95% CI 0.87 to 1.38, P=0.42). Tuberculosis disease was diagnosed in 21 children in the vitamin D group and 25 children in the placebo group (aRR 0.87, 95% CI 0.49 to 1.55). 29 participants randomized to vitamin D and 34 randomized to placebo were hospitalized for treatment of acute respiratory infections (aRR 0.86, 95% CI 0.52 to 1.40). Incidence of adverse events did not differ significantly between study arms. CONCLUSIONS: Vitamin D supplementation did not reduce risk of tuberculosis infection, tuberculosis disease or acute respiratory infections among vitamin D-deficient schoolchildren in Mongolia