Litsa uranium ore occurrence (Arctic zone of the Fennoscandian Shield): new results of petrophysical and geochemical studies

Mineralogical, petrophysical and geochemical studies have been carried out to determine the sequence and formation conditions of uranium mineralization within the Litsa ore occurrence (Kola Region). Mineralogical studies show the following formation sequence of ore minerals: uraninite – sulfides – uranophane, coffinite, pitchblende. Two stages of uranium mineralization are distinguished: Th-U (1.85-1.75 Ga) and U (400-300 Ma). The distribution of physical properties of rocks in the area is consistent with the presence of two temporal stages in the formation of mineralization with different distribution and form of uranium occurrence in rocks. The factors that reduce rock anisotropy are the processes of migmatization and hydrothermal ore mineralization, which heal pores and cracks. Fluid inclusions in quartz studied by microthermometry and Raman spectroscopy contain gas, gas-liquid and aqueous inclusions of different salinity (1.7-18.4 wt.% NaCl-eq.). According to homogenization temperatures of inclusions in liquid phase, the temperature of the Paleoproterozoic and Paleozoic stages of uranium mineralization at the Litsa ore occurrence is ~ 300 and 200 °С, respectively. Correlations of the spatial distribution of elastic anisotropy index with an elevated radioactive background allow using this petrophysical feature as one of the prognostic criteria for uranium and complex uranium mineralization when carrying out uranium predictive work

U-Pb (SHRIMP-RG) age of zircon from rare-metal (Li, Cs) pegmatites of the Okhmylk deposit of the Kolmozero-Voron’ya greenstone belt (northeast of the Fennoscandian shield)

The results of isotopic and geochronological study of zircon from rare-metal pegmatites of the Okhmylk deposit are presented. There were no reliable data on the age of lepidolite-spodumene-pollucite pegmatites of this and the other deposits spatially located within the Archean Kolmozero-Voron’ya greenstone belt. The earlier estimates of the pegmatite age indicate a broad time range from 2.7 to 1.8 Ga. Zircon in the studied pegmatites is characterized by inner heterogeneity, where core and rim zones are distinguished. Minor changes are observed in the core zones, they have a spotted structure and contain numerous uranium oxide inclusions. According to X-ray diffraction analysis, zircon crystallinity is preserved completely in these areas. Complete recrystallization with modification of the original U-Pb isotopic system occurred in the zircon rims. New U-Pb (zircon) isotopic and geochronological data of 2607±9 Ma reflect the time of crystallization of pegmatite veins in the Okhmylk deposit. Isotopic data with ages of ~1.7-1.6 Ga indicate later hydrothermal alteration. The obtained results testify to the Neo-Archean age of the formation of the Okhmylk deposit 2.65-2.60 Ga, reflecting the global age of pegmatite formation and associated the world's largest rare-metal pegmatite deposits

Cost-Effectiveness of Quadrivalent Human Papillomavirus Vaccination in Adolescent Girls in Russian Federation

The human papillomavirus (HPV) infection is one of the major risk factor of development of genital warts, a cervical dysplasia, a cervical cancer, and also some other oncologic diseases. The usage  of quadrivalent HPV vaccine in girls reduces the corresponding case  rate and the mortality significantly.The objective of this study is to analyze the cost-effectiveness of quadrivalent HPV vaccination cases of 12-year-old girls in Russian Federation.Methods. A Markov model is used on the basis of epidemiological data in Russian Federation. In base case the cost-effectiveness was  estimated from societal perspective. We assumed that the effect of  vaccination remains throughout all life. The analysis is performed for survival of 12-year-old girls. We considered only effect in the  vaccinated population. Costs for therapy of the diseases associated  with HPV infection corresponded to compulsory health insurance  rates across St. Petersburg for 2017. Costs and life expectancy have been discounted for 3.5% a year.Results. Quadrivalent HPV vaccination of 12-year-old girls in Russian Federation will allow to prevent counting on 100 000 the  vaccinated persons 2918 cases of genital warts, 5095 cases of  cervical dysplasia, 893 cases of invasive cervical cancer, 56 cases of  vulvar cancer, 18 cases of vaginal cancer, 13 cases of anal cancer, 7  cases of oropharyngeal cancer. The vaccination will provide cost  reduction, caused by HPV-associated diseases, for 453.9 million  rubles on 100 000 vaccinated, and 86.5% of the predicted prevented costs will be caused by decrease in incidence of cervical cancer, 9%  — cervical dysplasia, 2.9% — genital warts. The quadrivalent HPV vaccination is associated with an incremental cost-effectiveness ratio (ICER) of 247 560 rubles per quality adjusted life-year (QALY) and  334 200 rubles per life-year gained (LYG). Thus, in both cases, cost  effectiveness of rotavirus vaccination per 1 QALY will not exceed the  generally accepted threshold willingness-to-pay equal to three times  the gross domestic product in Russia (2016 — 1.76 million RUB).Conclusions. Quadrivalent HPV vaccination of girls prior to the beginning of sex life could be considered in Russian Federation as an economically effective technology for preventing HPV-associated diseases

Shkatulkalite, a Rare Mineral from the Lovozero Massif, Kola Peninsula: A Re-Investigation

The crystal structure of shkatulkalite has been solved from the crystal from the Lovozero alkaline massif, Kola Peninsula, Russia. The mineral is monoclinic, P2/m, a = 5.4638(19), b = 7.161(3), c = 15.573(6) Å, β = 95.750(9)°, V = 606.3(4) Å3, R1 = 0.080 for 1551 unique observed reflections. The crystal structure is based upon the HOH blocks consisting of one octahedral (O) sheet sandwiched between two heteropolyhedral (H) sheets. The blocks are parallel to the (001) plane and are separated from each other by the interlayer space occupied by Na1 atoms and H2O groups. The Na2, Na3, and Ti sites are located within the O sheet. The general formula of shkatulkalite can be written as Na5(Nb1−xTix)2(Ti1−yMn2+y)[Si2O7]2O2(OH)2·nH2O, where x + y = 0.5 and x ≈ y ≈ 0.25 for the sample studied. Shkatulkalite belongs to the seidozerite supergroup and is a member of the lamprophyllite group. The species most closely related to shkatulkalite are vuonnemite and epistolite. The close structural relations and the reported observations of pseudomorphs of shkatulkalite after vuonnemite suggest that, at least in some environments, shkatulkalite may form as a transformation mineral species

Distribution of SARS-CоV-2 seroprevalence among residents of the Tyumen Region during the COVID-19 epidemic period. Journal of microbiology, epidemiology and immunobiology

Introduction. In late 2019 - early 2020, an outbreak of infection caused by a novel strain of beta coronavirus SARS-CoV-2 was reported. The World Health Organization defined the disease as coronavirus disease 2019 (COVID-19). In the Tyumen Region, the first case of COVID-19 was diagnosed on 31/1/2020. The source of infection was a female student who came from Jinan, Shandong province (China). The number and rate of cases were steadily increasing from the 16th week through 28th week in 2020. The highest rate was 36.87 cases per 100 thousand people. Afterwards, the cumulative incidence kept increasing gradually, but not as quickly.The purpose of the seroepidemiological study was to measure the level and to identify the structure of herd immunity against the SARS-CoV-2 virus among the population of the Tyumen Region during the rapid spread of the COVID-19 outbreak.Materials and methods. Volunteers for participation in the study were selected through questionnaire surveys and random sampling. The exclusion criterion was an active COVID-19 infection at the time of the survey. A total of 2,758 individuals were tested for SARS-CoV-2 specific antibodies. The age of the surveyed volunteers ranged from 1 year to 70 years and older.Results of the study. During the active phase of the COVID-19 incidence, the population of the Tyumen Region showed moderate (24.5%) seroprevalence of SARS-CoV-2. At the same time, the tests revealed a high (97.8%) rate of asymptomatic infection cases in seropositive individuals who had never been diagnosed with COVID-19 and did not have history of positive PCR test results or acute respiratory infection symptoms on the day of testing. The maximum level of herd immunity was identified in children aged 1-6 years (34.7%), which was significantly higher compared to the average level of seroprevalence in the entire cohort. In recovered COVID-19 patients, antibodies were detected in 68.2%. In individuals with positive PCR test results, antibodies were detected in 64%. Conclusion. The results of the assessment of the level of herd immunity against the SARS-CoV-2 virus are crucial for prediction of the development trend of the epidemic and for planning specific and non-specific COVID-19 prevention measures