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BackgroundKrasnoyarsk region is a territory with the widespread risk factors for chronic obstructive pulmonary disease (COPD) such as tobacco smoke, air pollution, and occupational exposure. An assessment of COPD prevalence based on medical diagnosis statistics underestimates the true COPD prevalence. This study aims to evaluate how medical examinations may increase the accuracy of estimates of COPD prevalence.MethodsTrue COPD prevalence was estimated as a number of patients with the established disease diagnosis supplemented by the additional disease cases detected during medical examinations per 1,000 inhabitants of the region. Official medical statistics data and the data collected from the Global Alliance against Chronic Respiratory Diseases program 2011 among 15,000 inhabitants of the region aged 18 years and older were analyzed.ResultsThis study revealed the COPD cases without official medical diagnosis. The true prevalence of COPD is estimated to be two times higher than the prevalence estimates based on medical diagnosis statistics.ConclusionUndiagnosed and untreated cases of COPD result in severe COPD forms as well as addition of severe comorbidities. Because of this, there is an increase in the index of potential years of life lost. Conducting special medical examinations may increase the number of COPD cases detected at the early stages of the disease. This, in turn, may reduce the overall burden of the disease for the population of the region.

Abstract. Spectroscopic investigation and specific heat and magnetic susceptibility measurements of SmCr3(BO3)4 crystals were performed. The spectra of the Sm 3+ and Cr 3+ ions in samarium chromium borate were calculated and parameters of the exchange interactions between the nearest chromium ions, chromium and samarium ions were determined. Three phase transitions were observed at the temperatures T1= 7.8 ± 0.5 К, T2 = 6.7 ± 0.5 К, and T3 = 4.3 ± 0.2 К, their nature is discussed. The crystal structures with different space symmetry groups R32 and C2/c were found to coexist in а SmCr3(BO3)4 single crystal.Samarium chromium borate SmCr3(BO3)4 is a member of a large family of rare-earth (RE) borates with structural type of the natural mineral huntite. These compounds are described by a general formula RM3(BO3)4, where R is Y or La-Lu and М is Al, Ga, Fe, Cr, or Sc. The compounds are actively investigated due to their interesting physical properties and a promising application potential. However, RE chromium borates are not so well studied. It is known that NdCr3(BO3)4 is an easy-plane antiferromagnet below the temperature 8.0K [1] and that EuCr3(BO3)4 undergoes an antiferromagnetic phase transition at TN ≈ 9 К [2]. A phase transition at 5 К was supposed to occur in SmCr3(BO3)4 [3].We succeeded to prepare a big oriented single crystal of SmCr3(BO3)4 and to perform magnetic measurements on it. It follows from the temperature dependences of the magnetic susceptibility that the magnetic moments of chromium and samarium ions (samarium ions are polarized by the exchange field) are ordered in the ab-plane. However, as this sample was not preserved, heat capacity and optical spectra measurements were carried out on other samples. Crystal characterization by X-ray diffraction and infrared (IR) spectroscopy revealed a polytypic nature of SmCr3(BO3)4. The crystals can be rhombohedral (space group R32) or monoclinic (C2/c), depending on growth conditions. Moreover, domains of both structural phases can coexist in one single crystal. For measurements we chose the crystals with a predominant content of the R32 phase. The temperature dependence of the

A crystal fiber of yttrium scandate YScO 3 doped with Nd 3+ , with a cubic bixbyite-type crystal structure, has been synthesized through laser-heated pedestal growth for the first time. Its crystal structure has been determined using low-temperature (150 K) single-crystal X-ray diffraction: space group Ia3̅ , a = 10.2166(1) Å, R = 0.0177. A new phase was characterized with micro-Raman scattering and fluorescence. Fluorescence excitation measurements show two complex local positions of Nd 3+ in the crystal structure with lifetimes τ 1 = 290 and τ 2 = 250 μs ( 4 F 3/2 multifold) at a temperature T = 77 K.

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