15 research outputs found
The use of short-acting bronchodilators in patients with chronic bronchoobstructive pathology at the present stage
Inhaled short-acting bronchodilators (beta-agonists and M-anticholinergics) have been used for a long time in patients with bronchoobstructive diseases, the main representatives of which are chronic obstructive pulmonary disease (COPD) and bronchial asthma (BA). Given the fact that most patients with COPD and BA are treated with long-acting bronchodilators, the question arises about the place of short-acting drugs in modern treatment algorithms for bronchoobstructive pathology. The data on how many patients take short-acting beta-agonists and M- anticholinergics in real-life clinical practice, and how appropriate it is to use these drugs on top of prolonged drugs are provided. The Russian part of the international POPE-study analyzed the characteristics of outpatients with COPD. It was found that the vast majority of patients have short-acting bronchodilators as part of their therapy, and more than 50% of patients receive a combination of SABA and SAAC, and in most cases this is represented by a combination of fenoterol + ipratropium. Taking into account that the majority of patients with COPD and asthma receive prolonged bronchodilators, important from a practical point of view is the question of the effectiveness of short-acting drugs on the background of prolonged ones. The article discusses these aspects of therapy and provides evidence that the use of SABA and SAAC provides an opportunity to achieve additional bronchodilatation when used against the background of prolonged bronchodilators. Thus, symptomatic use of SABA and SAAC on demand in bronchoobstructive pathology have sufficient justification even in the presence of a combination of prolonged bronchodilators in patient therapy. At the same time, it is necessary to take into account the increased probability of side effects with such drug regimen. The article also discusses the issues of different types of inhalation devices for short-acting bronchodilators (nebulizers and metered-dose aerosol inhalers), provides data on their comparative effectiveness and safety
The substitution mechanism of Au in In-, Fe-and In-Fe-bearing synthetic crystals of sphalerite, based on the data from EPMA and LA-ICP-MS study
Research subject. Sphalerite (ZnS) is a widespread mineral that can be found in various depositional environments. During formation, this mineral can accumulate minor and trace impurities, with gold being one of the most valuable component. The issue of the chemical state of Au in sphalerite has been much discussed recently. Methods. Samples of In-, Fe-and In-Fe-bearing sphalerite with a composition ranging from 0 to 2.5 mol.% In2S3 and 0 ā 40 mol.% FeS were synthesized in an Au-saturated system using gas transport and salt flux techniques. The resulting products were subsequently investigated using EPMA and LA-ICP-MS. Results. All the elements under investigation are found to be homogeneously distributed within the sphalerite matrix. After quenching, sphalerite is shown to retain Au. Our data indicates that the observed increase in Au concentration is caused by the presence of In (up to 1.02 wt % Au) and, to a lesser extent, by that of Fe (up to ā600 ppm Au). These elements substitute Zn in the crystal structure of sphalerite following the scheme Au+ + In3+(Fe3+) ā 2Zn2+, which is in good agreement with previous data obtained using the XAS method. Conclusions.A higher sulphur fugacity in the system leads to a more significant accumulation of Au in sphalerite. The concentration of Au in pure sphalerite does not exceed 10 ppm under our experimental conditions and does not depend on the activity of sulphur in the system. Ā© 2019, AN Zavaritsky Institute of Geology and Geochemistry. All rights reserved.14-17-00693-P; Russian Foundation for Basic Research, Š Š¤Š¤Š: 18-05-70041The study was performed with financial support of RGNF grant No. 14-17-00693-P, in a final stage ā of the grant RFBR No. 18-05-70041
New data on mineralogy of volcanic-hosted massive sulfide deposits in the Urals
The study of mode of occurrence of Au, Ag, Bi, Se and Te covers a row of giant VMS deposits of the Urals (Uralian or Cu-Zn-pyritic type): nondeformed Safyanovsk, altered by late hydrothermal processes Uzelginsk, intensively deformed Gay and Uchaly and a few small polymetallic and Cu-Co deposits
Mineralogical features of ore of copper-pyritic deposit Yubileinoye (S. Urals)
Mineralogical composition features of large copper-pyritic Yubileinoye deposit (slightly metamorphized and now exploited by open pit) are studied. Major ore structures include impregnated, spotted, banded, stringer structures. Two generations of chalcopyrite, sphalerite and quartz, and 3 generation of pyrite were found. Proper gold minerals occur as tiny isolations of native gold (fineness 631-662) in veinlets accompanied by tennantite-tetrahedrite and galena; the connection of native gold with these minerals is supported by close correlation Au with Pb, As and Sb in ore composition
Contrasting fluids in the svetlinsk gold-telluride hydrothermal system, south urals
The large gold-telluride Svetlinsk deposit (~135 t Au) is considered to be a nontraditional one in the Urals and its origin is debated. A specific feature of the deposit is the abundance of various tellurides, such as tellurides of Fe, Ni, Pb, Sb, Bi, Ag, and Au. The new data of microthermometry, Raman spectroscopy, LA-ICP-MS, and crush-leach analysis (gas and ion chromatography, ICP-MS) for fluid inclusions as well as O-isotope data for quartz were obtained for the construction of PTX parameters of ore-formation and fluid sources in the deposit. Mineralisation was formed at a wide range of temperature and pressure (200ā400 Ā°C, 1ā4 kbar) and from contrasting fluids with multiple sources. At the early stages, the magmatic fluid evolved during its ascent and phase separation and the fluid derived from the host rock decarbonation and dehydration were involved in the hydrothermal system. In addition, mantle-derived fluid might be involved in the ore-forming process during gold-telluride precipitation as well as heated meteoric waters during the late stages. Early fluids were rich in H2S, S0, and CH4, while the Au-Te mineralisation was formed from N2-rich fluid. Ā© 2019 by the authors. Licensee MDPI, Basel, Switzerland
Noble metal speciations in hydrothermal sulphides
A significant part of the primary gold reserves in the world is contained in sulphide ores, many types of which are refractory in gold processing. The deposits of refractory sulphide ores will be the main potential source of gold production in the future. The refractory gold and silver in sulphide ores can be associated with micro-and nano-sized inclusions of Au and Ag minerals as well as isomorphous, adsorbed and other species of noble metals (NM) not thoroughly investigated. For gold and gold-bearing deposits of the Urals, distribution and forms of NM were studied in base metal sulphides by laser ablation-inductively coupled plasma mass spectrometry and by neutron activation analysis. Composition of arsenopyrite and As-pyrite, proper Au and Ag minerals were identified using electron probe microanalysis. The ratio of various forms of invisible goldāwhich includes nanoparticles and chemically bound goldāin sulphides is discussed. Observations were also performed on about 120 synthetic crystals of NM-doped sphalerite and greenockite. In VMS ores with increasing metamorphism, CAu and CAg in the major sulphides (sphalerite, chalcopyrite, pyrite) generally decrease. A portion of invisible gold also decreases āfrom ~65ā85% to ~35ā60% of the total Au. As a result of recrystallisation of ores, the invisible gold is enlarged and passes into the visible state as native gold, Au-Ag tellurides and sulphides. In the gold deposits of the Urals, the portion of invisible gold is usually <30% of the bulk Au. Ā© 2021 by the authors. Licensee MDPI, Basel, Switzerland