N.V. Sobolev1,2, V.Yu. Fridovsky3 1V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, pr. Akademika Koptyuga 3, Novosibirsk, 630090, Russia 2Novosibirsk State University, ul. Pirogova 2, Novosibirsk, 630090, Russia 3Diamond and Precious Metal Geology Institute, Siberian Branch of the Russian Academy of Sciences, pr. Lenina 39, Yakutsk, 677980, Russia
M.D. Tomshin1, A.G. Kopylova1, K.M. Konstantinov2,3, S.S. Gogoleva1
a:2:{s:4:"TYPE";s:4:"HTML";s:4:"TEXT";s:395:"1Diamond and Precious Metals Geology Institute, Siberian Branch of the Russian Academy of Sciences, pr. Lenina 39, Yakutsk, 677980, Russia 2Research Geological Enterprise ALROSA, Chernyshevskoe Shosse 16, Mirnyi, 678174, Russia 3Institute of the Earth’s Crust, Siberian Branch of the Russian Academy of Sciences, ul. Lermontova 128, Irkutsk, 664033, Russia";}
Keywords: Средний палеозой, Ar/Ar геохронология
, палеомагнитные исследования, дайковые пояса, долериты, Middle Paleozoic, 40Ar/39Ar geochronology, paleomagnetic studies, dike swarms, dolerites
We present results of study of the basites of the Vilyui paleorift. The 40Ar/39Ar isotopic ages were used to establish the sequence of their intrusion, which lasted ~18 Myr. Dolerite sills of the Kontai-Dzherba zone were the first crystallizing phase (378.0-380.7 Ma), which was followed by the intrusion of dikes of the Vilyui-Markha zone (372-373 Ma). Dikes of the Chara-Sinsk zone were the last crystalizing phase (362-364 Ma). The prolonged plume-lithosphere interaction resulted in the successive enrichment of basaltic melt with titanium, phosphorus, REE, HSFE, and LILE. Accumulation of the melt and formation of a magmatic lens at the crust-mantle boundary led to early crystallization of the melt at a depth of 35-40 km from the paleosurface under reducing conditions at a temperature of 1450-1470 °C. We assume that the inception and sequent opening of the Vilyui paleorift were associated with the relative rotation of 22° of the Angara-Anabar block with respect to the Aldan block in Early Famennian time. The Euler pole of rotation was located in the southern part of the paleorift, and a melting zone was directly beneath it.
O.P. Polyansky1, A.V. Prokopiev2, O.V. Koroleva2, M.D. Tomshin2, V.V. Reverdatto1, A.V. Babichev1, V.G. Sverdlova1, D.A. Vasiliev2 1V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, pr. Akademika Koptyuga 3, Novosibirsk, 630090, Russia 2Diamond and Precious Metal Geology Institute, Siberian Branch of the Russian Academy of Sciences, pr. Lenina 39, Yakutsk, 677980, Russia
Keywords: Дайка, рифтогенез, численное моделирование, Сибирская платформа, Якутско-Вилюйская крупная изверженная провинция, Dike, rifting, numerical modeling, Siberian Platform, Yakutsk-Vilyui Large Igneous Province
Possible mechanisms of rifting and the thermal regime of the lithosphere beneath the rift zone of the Vilyui sedimentary basin are considered based on the available isotopic ages of dike swarms, rates of sedimentation, and results of numerical modeling. Temporal correlations between the intrusion of mafic magma and a sharp increase in the rate of subsidence and sedimentation in the rift basin prove the contribution of both plate-tectonic and magmatic factors to the formation of the Vilyui rift. The results show a relationship between the rapid extension of the lithosphere and the formation of mafic dike swarms in the Yakutsk-Vilyui Large Igneous Province of the Siberian Platform at the Frasnian-Famennian boundary, with a peak at ~374.1 Ma, and at the end of the Late Devonian, with a peak at ~363.4 Ma. There were two pulses of dike formation during the rapid subsidence of the basin basement in the period 380-360 Ma, with a sedimentation rate of 100-130 m/Myr, at a background rate of 10-20 m/Myr. Analysis of numerical thermomechanical models revealed that the best-fit model is that combining the mechanisms of intraplate extension (passive rifting) and the ascent of a mantle magmatic diapir (active rifting). A conclusion about the nature of the heat source of trap magmatism has been drawn: The plume-driven regime of the lithosphere can better explain the dynamics of extension during rifting than the decompression melting mechanism.
a:2:{s:4:"TYPE";s:4:"HTML";s:4:"TEXT";s:362:"A.V. Prokopiev1, A.S. Borisenko2,3, G.N. Gamyanin1, V.Yu. Fridovsky1, L.A. Kondrat’eva1, G.S. Anisimova1, V.A. Trunilina1, E.A. Vasyukova2, A.I. Ivanov1, A.V. Travin2, O.V. Koroleva1, D.A. Vasiliev1, A.V. Ponomarchuk2,3";} 1Diamond and Precious Metal Geology Institute, Siberian Branch of the Russian Academy of Sciences, pr. Lenina 39, Yakutsk, 677980, Russia 2V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, pr. Akademika Koptyuga 3, Novosibirsk, 630090, Russia 3Novosibirsk State University, ul. Pirogova 2, Novosibirsk, 630090, Russia
Keywords: Металлогения, месторождения, золото, серебро, олово, Ar/Ar и U-Pb геохронология
, Верхояно-Колымская складчатая область, Metallogeny, mineral deposit, gold, silver, tin, 40Ar/39Ar and U-Pb geochronology, Verkhoyansk-Kolyma folded area
The paper presents new isotope geochronological data for several mineral deposits, ore occurrences, and related igneous bodies (plutons and dikes) in the Verkhoyansk-Kolyma folded area, eastern Yakutia. Twenty-one 40Ar/39Ar mica and four U-Pb zircon dates provide the first age constraints on key metallogenic units in the area. The dating results allow correlation between tectonic, magmatic, and metallogenic events. The sampled mineral deposits within the Adycha-Taryn fault zone in the southeastern Verkhoyansk-Chersky orogen apparently formed at the Jurassic-Cretaceous boundary during the final phase of the collision between the Siberian (North Asian) craton and the Kolyma-Omolon microcontinent (Kupol’noe deposit and the early metallogenic pulse of the Malotarynskoe deposit, ~143-144 Ma) and in the latest Early Cretaceous, in the beginning of the orogen collapse (Tallalakh and Dora-Pil’ deposits and the Malotarynskoe late metallogenic pulse, ~126 Ma). According to the suggested new classification of metallogenic units, these deposits belong to the Late Jurassic-Early Cretaceous Yana-Kolyma metallogenic belt. The Kyuchus deposit (~106 Ma), the Deputatsky ore cluster (~106-113 Ma), and the Khotoidokh deposit (~116 Ma) in the northern Verkhoyansk-Kolyma folded area belong to the North Verkhoyansk metallogenic belt. Their origin was associated with accretional and collisional processes that produced the Novosibirsk-Chukchi orogen in the middle Cretaceous. The Mangazeya ore cluster (~100 Ma, Early-Late Cretaceous boundary) in the southwestern end of the North Tirekhtyakh magmatic transverse belt belongs to the West Verkhoyansk metallogenic belt. The Nezhdaninskoe, Zaderzhnoe, Kurum, and Kuta deposits of the South Verkhoyansk area (~125-120 and ~100-95 Ma) can be joined into a single Verkhoyansk-Okhotsk metallogenic belt. The belt resulted from accretion and collision along the East Asian active continental margin and the related formation of the South Verkhoyansk orogen in the Early Cretaceous.
Several thousand clinopyroxene, garnet, and phlogopite inclusions of mantle rocks from Jurassic and Triassic kimberlites in the northeastern Siberian craton have been analyzed and compared with their counterparts from Paleozoic kimberlites, including those rich in diamond. The new and published mineral chemistry data make a basis for an updated classification of kimberlite-hosted clinopyroxenes according to peridotitic and mafic (eclogite and pyroxenite) parageneses. The obtained results place constraints on the stability field of high-Na lherzolitic clinopyroxenes, which affect the coexisting garnet and decrease its Ca contents. As follows from analyses of the mantle minerals from Mesozoic kimberlites, the cratonic lithosphere contained more pyroxenite and eclogite in the Mesozoic than in the Paleozoic. It virtually lacked ultradepleted harzburgite-dunite lithologies and contained scarce eclogitic diamonds. On the other hand, both inclusions in diamond and individual eclogitic minerals from Mesozoic kimberlites differ from eclogitic inclusions in diamond from Triassic sediments in the northeastern Siberian craton. Xenocrystic phlogopites from the D’yanga pipe have 40Ar/39Ar ages of 384.6, 432.4, and 563.4 Ma, which record several stages of metasomatic impact on the lithosphere. These phlogopites are younger than most of Paleozoic phlogopites from the central part of the craton (Udachnaya kimberlite). Therefore, hydrous mantle metasomatism acted much later on the craton periphery than in the center. Monomineral clinopyroxene thermobarometry shows that Jurassic kimberlites from the northeastern craton part trapped lithospheric material from different maximum depths (170 km in the D’yanga pipe and mostly ≤130 km in other pipes). The inferred thermal thickness of cratonic lithosphere decreased progressively from ~260 km in the Devonian-Carboniferous to ~225 km in the Triassic and to ~200 km in the Jurassic, while the heat flux (Hasterok-Chapman model) was 34.9, 36.7, and 39.0 mW/m2, respectively. Dissimilar PT patterns of samples from closely spaced coeval kimberlites suggest different emplacement scenarios, which influenced both the PT variations across the lithosphere and the diamond potential of kimberlites.
a:2:{s:4:"TYPE";s:4:"HTML";s:4:"TEXT";s:85:"G.N. Gamyanin1,2, V.Yu. Fridovsky2, O.V. Vikent’eva1";} 1Institute of Geology of Ore Deposits, Petrography, Mineralogy, and Geochemistry, Russian Academy of Sciences, Staromonetnyi per. 35, Moscow, 119017, Russia 2Diamond and Precious Metal Geology Institute, Siberian Branch of the Russian Academy of Sciences, pr. Lenina 39, Yakutsk, 677980, Russia
Keywords: Адыча-Тарынская металлогеническая зона, благороднометалльная минерализация, стабильные изотопы, флюидные включения, генезис месторождений, Adycha-Taryn metallogenic zone, noble-metal mineralization, stable isotopes, fluid inclusions, genesis of deposits
The regional geologic setting of the Adycha-Taryn metallogenic zone, one of the areas most productive for noble-metal mineralization in northeastern Russia, is discussed. The intricate metallogenic history of the zone and the prolonged geodynamic activity of its ore-hosting structures are documented. Different types of mineralization, such as hydrothermal-metamorphogenic, gold-bismuth, gold-quartz, gold-antimony, and silver-antimony, are described. New data on the isotopic compositions of oxygen in quartz, sulfur in sulfides, and oxygen and carbon in carbonates from different mineralization types are presented. The early metamorphogenic quartz beyond the ore zones has δ18O = +20.1 ± 2.0 ‰. At the gold-bismuth deposits, the δ18O values of quartz are within the narrow range of +12.5 ± 0.4 ‰. Quartz from the gold-quartz mineralization shows much wider variation in δ18O values, from +14.2 to +19.5 ‰. A similar range (δ18O = +16.5 to +19.8 ‰) is observed for the gold-antimony mineralization. Cryptograined quartz from the gold-antimony mineralization is enriched in light oxygen isotopes (δ18O = -3.2 to +4.7 ‰). The following δ34S values have been established in sulfides of mineralization of different types ( ‰): gold-bismuth, -3.7 to -2.2 (Apy) and -6.7 to -6.8 (Py); gold-quartz, -2.1 to +2.4 (Apy), -6.6 to +5.4 (Py), and -6.1 to +4.2) (Ant); gold-antimony - -2.0 to +1.6 (Apy), -3.5 to +2.1 (Py), and -5.3 to +0.2 (Ant); and silver-antimony, -2.0 to -1.9 (Apy), -2.2 ± 0.1 (Py), and -5.7 to -5.6 (Ant). The δ13C and δ18O values are contrasting in the studied types of mineralization, varying respectively from -6.9 to -5.9 ‰ and from +2.1 to +5.7 ‰, (gold-bismuth), from -9.1 to -6.1 ‰ and from +12.4 to 18.7 ‰ (gold-quartz), from -12.1 to -9.5 ‰ and from +15.0 to +16.3 ‰ (gold-antimony), and from -11.6 to -11.1 ‰ and from +1.5 to +4.7 ‰ (silver-antimony). Metamorphogenic calcites are rich in both heavy C (-1.1 to -1.7 ‰) and heavy O (+20.3 to +20.5 ‰) isotopes. Microthermometric study and crush-leach analysis of fluid inclusions have revealed differences in the composition of ore-forming fluids and formation conditions for different types of mineralization. The isotopic compositions of O, C, and S of mineral-forming fluids suggest a significant input of magmatic fluids to the formation of gold-bismuth and gold-antimony deposits, the contribution of metamorphic fluids increases at gold-quartz deposits, and meteoric water is involved in the formation of silver-antimony deposits.
a:2:{s:4:"TYPE";s:4:"TEXT";s:4:"TEXT";s:46:"L.A. Kondrat’eva, G.S. Anisimova, A.I. Zaitsev";}
Diamond and Precious Metal Geology Institute, Siberian Branch of the Russian Academy of Sciences, pr. Lenina 39, Yakutsk, 677980, Russia
Keywords: Гранитоидный магматизм, метаморфизм, Au-Bi (Te), Au-Ag (Sb) оруденение, флюидные включения, Ar/Ar, Rb/Sr возраст, месторождение Задержнинское, Южное Верхоянье, Granitoid magmatism, metamorphism, Au-Bi (Te) and Au-Ag (Sb) mineralization, fluid inclusions, Ar/Ar and Rb-Sr ages, Zaderzhnoe deposit, South Verkhoyansk region
Based on results of study of the regional position, chemical composition of ores, fluid inclusions, and age relationships between mineralization and igneous rocks, we propose a geological and genetic model for the formation of gold mineralization of the Zaderzhninskoe deposit. Mineralization is located in the tectonic node of the intersection of two regional structures in the supraintrusive zone of a latent granitoid pluton among the terrigenous rocks of the Verkhoyansk complex, which are regionally metamorphosed to the greenschist facies. The sequential deposition of three types of mineralization - Au-quartz (including early low-gold Au-As and late productive Au-Pb-Zn types), Au-rare-metal, and Au-silver - has been established. The Au-Bi (Te) assemblage contains native bismuth, bismuthine, hedleyite, Bi sulfotellurides, gustavite group minerals, and secondary minerals - Bi oxides and Bi tellurites with low-grade gold. Hg-containing electrum and kustelite, Ag-Sb and Ag-Pb-Sb sulfosalts, stutzite, Te-Pb-containing canfieldite, freibergite, and Au and Ag sulfides are indicator minerals of the Au-Ag (Sb) assemblage. Ore formation occurred at temperatures from 90 to 340 ºC, with the participation of lowly and moderately concentrated solutions with CO2 ± CH4 ± N2 gas phase. A decrease in temperature from Au-quartz mineralization (200-220 ºC) to the late epithermal one (160 ºC) and a slight increase in the concentration of solutions (up to 10 wt.% NaCl equiv.) have been established. The deposit resulted from the intricate multistage geodynamic evolution of the South Verkhoyansk region. Ore-forming processes are associated with the evolution of magmatic objects. Dating of igneous rocks yields the following ages: diorites - 130-137 Ma (Rb-Sr), spessartites - 126 ± 3 Ma (Rb-Sr), and kersantites - 115 ± 1.7 Ma (Ar/Ar). Early concordant Au-quartz (Au-As) mineralization of the deposit is comparable with metamorphic-related Au-quartz veins of the Yur-Bular type, and its age is taken as >137 Ma. The time of formation of Au-quartz (Au-Pb-Zn) mineralization is estimated at 123.5 ± 1.6 Ma (Ar/Ar) and is coeval with the time of intrusion of the Early Cretaceous granitoids of the South Verkhoyansk region. The imposed low-temperature mineralization undoubtedly has a younger age. Its formation was followed by the successive deposition of Au-rare-metal mineralization at the final stage of formation of granitoid plutons (~120 Ma) and Au-Ag mineralization in the period 100 ± 5 Ma, i.e., the time of formation of late-stage granodiorite-granite intrusions.
A.V. Okrugin1, A.S. Borisenko2,3, I.R. Prokopiev2, A.I. Zhuravlev1 1Diamond and Precious Metal Geology Institute, Siberian Branch of the Russian Academy of Sciences, pr. Lenina 39, Yakutsk, 677980, Russia 2V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, pr. Akademika Koptyuga 3, Novosibirsk, 630090, Russia 3Novosibirsk State University, ul. Pirogova 2, Novosibirsk, 630090, Russia
Keywords: Дуниты, шонкиниты, хромиты, диопсиды, платина, дифференциация магмы, Инаглинский массив, Dunites, shonkinites, chromites, diopsides, platinum, magma differentiation, Inagli massif
We consider the mineralogical and geochemical features of the rocks of the Inagli dunite-clinopyroxenite-shonkinite massif with platinum-chromite and unique jewelry Cr-diopside mineralization, which is a reference object of concentric zonal complexes. The massif rocks, from dunites to pulaskites, including peridotites, clinopyroxenites, shonkinites, and melanocratic alkali syenites, form a single continuous comagmatic series. This is confirmed by a clear dependence of the compositions of olivine, pyroxene, phlogopites, and Cr-spinels on the MgO content of the rocks and on the behavior of trace elements in them. The similar compositions of pyroxenes and trace-element patterns of clinopyroxenite rocks and Cr-diopsidite veins indicate a genetic similarity of these rocks. The age and mineralogical and geochemical compositions of the rocks and the geologic and morphological features of the intrusion prove that the Inagli massif formed from high-K picritoid melts, which underwent gradual decompression solidification during the ascent and formed a cylindrical diapir-like body at the subsurface level in the Early Cretaceous. The new portions of differentiates supplied from the lower horizons of the magma column determined the complex composition of the massif: It has a concentric zonal structure cut by numerous radial-circular vein bodies of pegmatites and pure anchimonomineral rocks (Cr-diopsidites), in places, of jewelry quality.
Z.S. Nikiforova, B.B. Gerasimov, E.G. Glushkova, A.G. Kazhenkina
Diamond and Precious Metal Geology Institute, Siberian Branch of the Russian Academy of Sciences, pr. Lenina 39, Yakutsk, 677980, Russia
Keywords: Индикаторные признаки золота, россыпное золото, формационные типы месторождений, прогнозирование, Indicative features of gold, placer gold, formation types of deposits, prediction
Prediction and search for gold deposits in the east of the Siberian Platform are problematic because the study area is overlain by a thick cover of MZ-KZ deposits. Search for gold deposits by the largest geological institutions using conventional methods have not yielded positive results, because the main attention was focused on the discovery of ancient gold-bearing conglomerates of the Witwatersrand type and on the evaluation of the gold ore potential of basic magmatism. Typomorphism of placer gold bears huge information about the genesis of native gold, both its primary endogenous origin and its exogenous transformation, which makes it possible to identify the formation type of mineralization, increases the reliability of the prediction of gold deposits, and ensures their purposeful search in the platform areas. The revealed indicative features of placer gold made it possible to substantiate the formation of the gold ore sources of Precambrian low-sulfide gold-quartz, gold-iron-quartzite, porphyry gold-copper, and gold-PGE mineralization and Mesozoic gold-silver, gold-rare-metal, and gold-sulfide-quartz mineralization in the east of the Siberian Platform. We have established that high-fineness placer gold with microinclusions of pyrite, arsenopyrite, quartz, and carbonates with recrystallized structures and lines of plastic deformation is specific to the ore sources of low-sulfide gold-quartz mineralization. A high content of Cu (up to 4 %) in flaky high-fineness gold is one of indicators of porphyry gold-copper mineralization. The angular shape of gold grains, the fine fraction and high fineness of gold, its completely recrystallized and regrown internal structure, and the permanent presence of Fe, Bi, and Cu microimpurities and hematite, ilmenite, and corundum microinclusions are typical of gold-iron-quartzite mineralization. Flaky and laminated high-fineness gold particles with steady Pt, Pd, and Ni impurities and Pt-mineral phases and Au-Pt intergrowths in them testify to the ore sources of gold-PGE mineralization. Laminated and cloddy gold fractions of > 0.25-2.0 mm, the medium and low fineness of gold, its single-crystal or, sometimes, porous internal structure, the wide range of microimpurities (Pb, Zn, As, Sb, Cu, Te, etc.), and microinclusions of native Ag, adularia, Sr-barite, and calcite are indicators of gold-silver mineralization. Laminated, dendritic, and cloddy-angular gold grains, wide variation in gold fineness (307-950 ‰), and the presence of microinclusions of native bismuth, maldonite, arsenopyrite, and silver tellurides are indicative of gold-rare-metal mineralization. Laminated and cloddy gold grains, their size varying from dust to >0.25 mm, their mono- and coarse-grained internal structure, wide variation in gold fineness (600-900 ‰), and the presence of Hg microimpurities (up to 6 % and more) and microinclusions of quartz, calcite, pyrite, arsenopyrite, tellurides, selenides, and REE phosphates point to gold-sulfide-quartz mineralization. The established placer gold indicators of the particular formation types of ore sources in the east of the Siberian Platform made it possible to predict Precambrian gold deposits with low-sulfide-gold-quartz mineralization similar to the Kirkland Lake and Porcupine mines and gold deposits with Mesozoic gold-silver mineralization similar to the Cripple Creek mine. The developed criteria for determining the types of mineralization by indicative features of placer gold give an insight into the ore genesis and can be successfully applied to prediction and search for gold deposits and to evaluation of their gold resources.
E.V. Lazareva1, S.M. Zhmodik1,2, A.V. Prokopiev3, N.S. Karmanov1, A.I. Sergeenko3 1V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, pr. Akademika Koptyuga 3, Novosibirsk, 630090, Russia 2Novosibirsk State University, ul. Pirogova 2, Novosibirsk, 630090, Russia 3Diamond and Precious Metal Geology Institute, Siberian Branch of the Russian Academy of Sciences, pr. Lenina 39, Yakutsk, 677980, Russia
Keywords: Нодулярный монацит (куларит), редкоземельные элементы, Куларский кряж, Nodular monazite (kularite), rare-earth elements, Kular Ridge
Nodular monazite occurs in metamorphic rocks worldwide and has zonal REE patterns. This paper focuses on the composition of nodular monazite hosted by Permian black shales of the Kular Ridge in the Kular-Nera terrane. This monazite variety (called kularite in the Russian literature) reaches commercial amounts in placers of the area. The contents of Ce, Nd, and La in the analyzed monazite nodules show correlations at Ce/Nd = 14.39La ± 0.0919 (in apfu) and Ce/Nd = 0.2318La ± 0.1135 (in wt.%) and vary regularly from core to rim. All monazite compositions fall on this trend, but specific grains may plot in its different parts. Thermodynamic calculations indicate that monazite forms via an intermediate precursor (LnPO4 · 2H2O). The Ce:La:Nd changes in different grains record Eh-pH variations during nucleation and a gradual temperature increase during subsequent growth. The Ce:La:Nd ratio changes partly in grain rims as a result of oxidative dissolution. Judging by the tectonic setting, REE came to the Kular-Nera rocks from the weathered Tomtor Nb-REE deposit, being transported by the Paleo-Khatanga River with monazite nanoparticles bound to the surface of clay minerals.
a:2:{s:4:"TYPE";s:4:"HTML";s:4:"TEXT";s:164:"E.I. Nikolenko1, A.M. Logvinova1,2, A.E. Izokh1,2, V.P. Afanas’ev1, O.B. Oleynikov3, A.Ya. Biller3";} 1V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, pr. Akademika Koptyuga 3, Novosibirsk, 630090, Russia 2Novosibirsk State University, ul. Pirogova 2, Novosibirsk, 630090, Russia 3Diamond and Precious Metal Geology Institute, Siberian Branch of the Russian Academy of Sciences, pr. Lenina 39, Yakutsk, 677980, Russia
Keywords: Шпинель, карнийский ярус, алмаз, щелочной магматизм, осадочный коллектор, триас, Сибирская платформа, Spinel, Carnian Stage, diamond, alkaline magmatism, sedimentary reservoir, Triassic, Siberian Platform
An assemblage of Cr-spinels widespread in Carnian (Upper Triassic) diamondiferous deposits in the northeastern Siberian Platform is studied. Analysis of their morphology and chemical composition has revealed two dominant varieties of Cr-spinels and has demonstrated certain regularities in their distribution in the study area. Correlations have been established between the areal distribution of the recognized types of Cr-spinels and diamond varieties typical of kimberlite sources and between the distribution of Cr-spinels and rounded diamond dodecahedrons. The phase and chemical compositions of polyphase inclusions in the Cr-spinels are studied. The spatial arrangement of inclusions along the crystal growth zones indicates their primary genesis and trapping from the melt during crystallization. Compositional features of some minerals in the inclusions-SiO2 impurity in apatite and high CaO contents (0.2-0.8 wt.%) in olivines-point to a nonkimberlite source of these Cr-spinels. The presence of K- and Na-containing phases and calcite in the inclusions indicates saturation of the initial melt with alkalies, Ca, and CO2. The data obtained suggest that the numerous Late Vendian diatremes in K-rich alkaline basites of the Olenek Uplift area are the source of the dominant Cr-spinel variety.
a:2:{s:4:"TYPE";s:4:"HTML";s:4:"TEXT";s:416:"N.V. Sobolev1,2, A.V. Sobolev3, A.A. Tomilenko1, D.V. Kuz’min1,2, S.A. Grakhanov4, V.G. Batanova3, A.M. Logvinova1,2, T.A. Bul’bak1, S.I. Kostrovitskii5, D.A. Yakovlev5, E.N. Fedorova1, G.F. Anastasenko6, E.I. Nikolenko1, A.V. Tolstov7, V.N. Reutskii1";} 1V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, pr. Akademika Koptyuga 3, Novosibirsk, 630090, Russia 2Novosibirsk State University, ul. Pirogova 2, Novosibirsk, 630090, Russia 3V.I. Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, ul. Kosygina 19, Moscow, 119991, Russia 4Diamond and Precious Metal Geology Institute, Siberian Branch of the Russian Academy of Sciences, pr. Lenina 39, Yakutsk, 677980, Russia 5A.P. Vinogradov Institute of Geochemistry, Siberian Branch of the Russian Academy of Sciences, ul. Favorskogo 1a, Irkutsk, 664033, Russia 6St. Petersburg State University, Universitetskaya nab. 7/9, St. Petersburg, 199034, Russia 7AK ALROSA Scientific Research and Geological Exploration Enterprise, ul. Lenina 6, Mirnyi, 678170, Republic of Sakha (Yakutia), Russia
Keywords: Литосферная мантия, гипабиссальный кимберлит, оливин, алмаз, мезозой, U/Pb изотопное датирование, циркон, перовскит, рутил, Сибирская платформа, Литосферная мантия, гипабиссальный кимберлит, оливин, алмаз, мезозой, U/Pb изотопное датирование, циркон, перовскит, рутил, Сибирская платформа, Lithospheric mantle, hypabyssal kimberlite, olivine, diamond, Mesozoic, U/Pb isotope dating, zircon, perovskite, rutile, Siberian Platform
The objects of study are Triassic hypabyssal diamondiferous kimberlites with an age of 220-245 Ma, containing macrocrysts of unaltered olivine. The latter are close in the time of formation to the main stage of intrusion of the Siberian Trap Province (252 Ma), which lasted less than 1 Myr. A comparative high-precision analytical study of the Ti, Ca, Cr, and Al impurity patterns of about 1000 olivine macrocryst samples with a forsterite content Fo = [100Mg/(Mg + Fe)] of 78 to 93 has demonstrated the effect of traps on the lithospheric composition. A comprehensive comparative study of diamonds from northern placers and Triassic kimberlites, including determination of their carbon isotope composition, was performed. Chromatography-mass-spectroscopic analysis of submicron fluid inclusions in diamonds from northern placers and kimberlites has shown prevailing hydrocarbons of a wide range of compositions and subordinate contents of N2, H2O, and CO2. These findings, together with the results of previous studies of subcalcic Cr-pyropes and diamonds found in the Lower Carboniferous gritstones of the Kyutyungde graben, lead to the conclusion that the Toluopka kimberlite field is promising for Paleozoic kimberlites. The results of comprehensive studies of diamonds and indicator minerals and U/Pb isotope dating of numerous detrital zircon samples from the basal horizon of the Carnian Stage (Upper Triassic) of the Bulkur site in the lower reaches of the Lena River suggest the presence of diamondiferous kimberlites within the northeastern Siberian Platform. The age of the probable primary diamond sources in the study area can be evaluated by an integrated U/Pb isotope dating of zircons, perovskites, and rutiles from the developed diamond placers and from the basal horizon of the Carnian Stage.
V.A. Kashirtsev1,2, T.M. Parfenova1,2, A.K. Golovko1, B.L. Nikitenko1,2, I.N. Zueva3, O.N. Chalaya3
a:2:{s:4:"TYPE";s:4:"HTML";s:4:"TEXT";s:362:"1A.A. Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch of the Russian Academy of Sciences, pr. Akademika Koptyuga 3, Novosibirsk, 630090, Russia 2Novosibirsk State University, ul. Pirogova 2, Novosibirsk, 630090, Russia 3Institute of Oil and Gas Problems, ul. Oktyabr’skaya 1, Yakutsk, 677890, Russia";}
Keywords: Органическая геохимия, фенантрены, биомаркеры, битумоид, осадочные породы, нефть, Сибирская платформа, Organic geochemistry, phenanthrenes, biomarkers, bitumen, sedimentary rocks, oil, Siberian Platform
The composition and distribution of phenanthrenes (polyaromatic compounds) have been studied in chloroform extracts from dispersed organic matter (OM) of clayey, siliceous, carbonate, and terrigenous rocks of different ages and facies and from some oils of the Siberian Platform. Phenanthrenes have been analyzed by gas chromatography-mass spectrometry. High contents of 1,7,8-trimethylphenanthrene and 1,1,7,8-tetramethyl-1,2,3,4-tetrahydrophenanthrene are present in the OM of Vendian and Cambrian carbonate-shale deposits and in ancient oils of the Nepa-Botuobiya and Anabar anteclises. The OM of Permian continental deposits and oils of the Vilyui syneclise is dominated by 1-methyl-7-isopropylphenanthrene (retene). A triangular diagram for identification of the types of original OM of rocks and classification of genetically related oils has been constructed based on the assessment of phenanthrene biomarker distribution. Putative pathways of the formation of phenanthrene biomarkers are discussed.
In this paper, a history of the development, current state, and specifications of the first automated site established for atmospheric composition observations on the base of the Siberian Lidar Station of the IAO SB RAS in December 1992 are presented. The results of the analysis of long-term changes in air quality observed in the vicinity of the Tomsk Scientific Centre have revealed its noticeable deterioration occurred during the past 10 years.
A.V. Kashkovsky1, P.V. Vashchenkov1, A.N. Krylov2, and L.V. Mishina2
a:2:{s:4:"TEXT";s:268:"1Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russia
2RSC “Energia”, Korolev, Russia
E-mail: sasa@itam.nsc.ru">sasa@itam.nsc.ru";s:4:"TYPE";s:4:"html";}
Keywords: molecular shield, vacuum, test particle method, method of direct statistical modeling
Pages: 643–658
Here, we present the results of computational studies of gas parameters in the high rarefaction zone formed behind a molecular shield mounted on the OKA-T spacecraft. The method of accounting for the effect of solar cell rotation on the rarefaction zone is described. The influence of jets of on-site engines and gas emission of the apparatus on the rarefaction zone has been estimated.
Yu.G. Ermolaev1, A.D. Kosinov1,2, A.N. Semenov1,3, N.V. Semionov1, and A.A.Yatskikh1,2 1Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russia 2Novosibirsk State University, Novosibirsk, Russia 3Sobolev Institute of Geology and Mineralogy SB RAS, Novosibirsk, Russia
E-mail: semion@itam.nsc.ru
Keywords: supersonic boundary layer, swept wing, laminar-turbulent transition, unit Reynolds number
Pages: 659–665
An experimental study of the influence of unit Reynolds number on the position of laminar-turbulent transition in swept-wing boundary layer at supersonic flow velocities was carried out. In the experiments, a swept-wing model with 3-% circular arc airfoil and 45-deg gliding angle of wing edges was used. The position of the transition was identified using a hot-wire anemometer. It was found that at М = 2 and 2.5, an increase in the unit Reynolds number (Re1) leads to a transition delay. It was shown that an increase in freestream Mach number and in the level of flow pulsations in the wind-tunnel test section leads to a less pronounced influence of Re1 on the transition position. At a high noise level due to the growth of Mach number or due to the introduction of vortical disturbances, no effect due to unit Reynolds number on the transition position was observed.
A.V. Boiko1, 2, A.V. Dovgal1, and A.M. Sorokin1 1Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russia 2Tyumen State University, Tyumen, Russia
E-mail: boiko@itam.nsc.ru, dovgal@itam.nsc.ru
Keywords: hydrodynamic stability, boundary-layer separation, flow past a backward-facing step, unsteady flow
Pages: 667–673
The influence of the low-frequency modulation of flow behind a rectangular backward-facing step on the amplitude characteristics of disturbances in the separated laminar boundary layer has been studied. The experimental data were obtained by the method of hot-wire anemometry in a wind tunnel at a low subsonic velocity. Response of the separated flow to the long-wave oscillations generated by a local source of disturbances on the surface of the experimental model was clarified. The low-frequency nonstationarity of the separation region leads to a growth of velocity fluctuations in the separated boundary layer, which dominate the laminar-turbulent transition and the state of the flow in the near-wall region.
The
promising method of drag reduction with the use of micro-blowing through
the streamlined surface has been proposed for its use to the external
surface of high-speed train. The advantages of high-speed train as an object of
micro-blowing application are introduced. The corresponding RANS-based
mathematical model is elaborated, and the computations of the external
flow around a long train body are performed. Predictions of the turbulent
boundary layer over penetrable surface with different modes of micro-blowing
have been presented and analyzed. The developed modifications of mathematical
model of turbulence have been used to take into account the micro-blowing
influence in the inner region of turbulent boundary layer. The obtained results
of parametric analysis of drag reduction depending on the area of permeable sections, intensity of micro-blowing, and
high-speed train length have been analyzed. In particular, the
dependence between drag reduction effect and length of train body with realized
micro-blowing as well as its intensity is established. Realization of
micro-blowing with blowing velocity just 0.25 % of train speed (V = 100 m/s) on the
70 % of the streamlined surface area for just one train carriage (L = 25 m) allows one to
reduce the aerodynamic drag (including the most actual friction and
head-tail pressure components) of the whole train (L = 200 m) by about 5.25 %, so in case of
micro-blowing realization on all its 8 carriages, the train’s aerodynamic drag
can be reduced approximately by 42 %.
Under
the experimental studies carried out to reduce the sonic boom intensity created
by the aircraft by means of active action, the problem of measuring the shock
wave parameters in nonuniform flow is considered. Comparison of the pressure
profiles behind the shock wave obtained by means of a drained measuring plate
and a comb of brake pressure probes is given. It is shown that the technique
using brake pressure probes provides an acceptable reliability of pressure
distributions measurements in the near zone of the model. The use of the
drained plate leads to significant errors in measuring under nonuniform flow
conditions. Analysis of the causes of signal distortion is carried out.
The procedure for experimental data processing is presented.
The
article presents the results of experimental studies of the influence of
different designs of mixing spacer grids on the coolant flow in FA-KVADRAT PWR.
The investigations were carried out by simulating the coolant flow in the core
on the experimental air stand being an aerodynamic open loop through which air
is pumped. To measure the local hydrodynamic characteristics of the
coolant flow, special pneumometric sensors were used for measuring
the total velocity vector and the flow rate value. During the
investigations of the local hydrodynamics of the coolant, transverse flow
velocity, as well as the coolant flow rates in the cells of the experimental
model FA-KVADRAT, was measured. The analysis of spatial distribution of
projections of absolute flow velocity allowed studying and detailing the
coolant flow pattern behind the mixing spacer grids with different designs of
deflectors as well as selecting the op-timal design of the deflector. The
accumulated database on the coolant flow in FA-KVADRAT has formed
the basis for engineering assessment of active zones’ structures of PWR.
The results of experimental studies are used to verify CFD codes (in both
foreign and domestic development) as well as programs for detailed cell-by-cell
calculation of active zones in order to reduce conservatism when assessing heat
engineering reliability.
The
heat transfer at superposition of high-frequency oscillations on a laminar flow
of a liquid in flat and rectangular channels at a distance from an inlet of a
heated site is investigated under boundary conditions on channel walls of the
first and second kind. For the flat channel, the obtained analytical
expressions for the amplitude and phase profiles of the longitudinal velocity oscillations
are used as a function of the dimensionless oscillation frequency in the form
of functions of a real variable. It is shown that the mean value taken for the
perimeter of the channel and also the period of oscillations, the Nusselt
number for large amplitudes of mean velocity oscillations over the cross
section can significantly exceed its stationary value. The limiting value of
the ratio of Nusselt numbers for a pulsating and steady flow in the region
of high pulsation frequencies is found.
A.K. Shukla and A. Dewan Indian Institute of Technology Delhi, New Delhi, India
E-mail: adewan@am.iitd.ac.in
Keywords: jet impingement, ribs, heat transfer, turbulence modeling, Nusselt number, RANS
Pages: 717–734
A
computational study is carried out to assess the suitability of various RANS
based turbulence models for slot jet impingement on flat and ribbed surfaces
with various values of Reynolds number and jet to plate
spacing. The computed results are compared with the reported experimental data.
It was observed that none of the turbulence models considered predicted the
heat transfer data accurately. However, some models predicted the experimental
data with good trends, e.g., secondary peak and several spikes in Nusselt
number for ribbed surface, with a precise computation of the stagnation point
Nusselt number. Further, the effects of slot width, rib pitch and jet to ribbed
surface spacing were investigated for jet impingement on a ribbed surface. It
was observed that the local Nusselt number increased with slot width and rib to
plate spacing. It was also observed that increasing Reynolds number had a
positive effect on the local heat transfer. With increasing rib pitch the local
Nusselt number increased near the stagnation zone but decreased downstream. The
observed flow pattern was different for jet impingement on a ribbed surface
than that on a flat surface.
Valeriy Vyacheslavovich CHERNYKH1, Olga Viktorovna ERMAKOVA1, Nikolay Borisovich ORLOV2, Olga Olegovna OBUKHOVA3, Olga Mikhaylovna GORBENKO3, Alya Petrovna SHVAYUK3, Alena Viktorovna EREMINA1,3, Aleksandr Nikolaevich TRUNOV1 1S. Fyodorov Eye Microsurgery Federal State Institution of Minzdrav of Russia, Novosibirsk Branch 2Research Institute for Clinical and Experimental Lymphology - a Branch of Federal Research Center of the Institute of Cytology and Genetics of SB RAS 3Research Institute for Experimental and Clinical Medicine of Federal Research Center for Fundamental and Translational Medicine
Keywords: первичная открытоугольная глаукома, провоспалительные цитокины, внутриглазная жидкость, слезная жидкость, primary open-angle glaucoma, pro-inflammatory cytokines, intraocular fluid, lacrimal fluid
Purpose: to study the content of proinflammatory cytokines IL-6, IL-8 and IL-17 in lacrimal and intraocular fluid in patients with advanced stage of primary open-angle glaucoma. Material and methods. The study included 56 patients with advanced stage diagnosis of primary open-angle glaucoma (POAG). The diagnosis was determined by ophthalmological examination, including visual acuity, binocular ophthalmoscopy, spheroperimetry, echoophthalmography, optical coherence tomography, intraocular pressure measurement. The number of men was 21 (37.5 %), women - 35 (62.5 %), the average age of patients was 62.8 ± 4.3 years. Exclusion criteria were acute and exacerbation of chronic inflammatory diseases of the organ of vision, diabetic retinopathy, neovascular glaucoma, uveitis, hemophthalmia, autoimmune and tumor processes of any localization, as well as acute and exacerbations of chronic inflammatory diseases of any organs and systems. Patients who took drugs containing prostaglandins analogues for intraocular pressure normalization, that could activate the inflammatory process, were excluded from the study. A comparison group was composed of 30 patients with the uncomplicated cataract diagnosis. All patients underwent the determination of IL-6, IL-8, IL-17 in the lacrimal and intraocular fluid. Results. It has been established that the significant increase in the concentrations of IL-6, IL-8 and IL-17A in the lacrimal and intraocular fluid was revealed in patients with advanced stage of POAG in comparison with those obtained in patients with uncomplicated cataracts. The obtained data testify to the presence of local destructive-inflammatory process in the mechanisms of the development of primary open-angle glaucoma. The revealed unidirectional change in the concentrations of IL-6 (2.8 times the lacrimal fluid and 5.2 times in the intraocular fluid), IL-8 (1.5 times in the lacrimal fluid and 4 times in the aqueous humor), IL-17 (1.75 times in lacrimal fluid and 1.95 times in the intraocular fluid) allows us to conclude that lacrimal fluid can be used to assess changes in cytokine content in the pathogenesis of ophthalmic diseases.
Anzhella Zhanovna FURSOVA1,2, Nadezhda Viktorovna CHUBAR1, Mikhail Sergeevich TARASOV1, Mariya Andreevna VASILYEVA1, Sarafroz Aftondilkizi ERKINOVA3,4, Aleksandra Sergeevna SHADRINA2,4, Ekaterina Alekseevna SOKOLOVA3,4, Maksim Leonidovich FILIPENKO3,4 1Novosibirsk State Region Hospital 2Novosibirsk State Medical University of Minzdrav of Russia 3Institute of Chemical Biology and Fundamental Medicine of SB RAS 4Novosibirsk State University
Keywords: диффузный макулярный отек, оптическая когерентная томография, фовеолярная толщина сетчатки, ранибизумаб, diffuse macular edema, optical coherence tomography, foveolar thickness of retina, ranibizumab
Apart from already established clinical factors, the polymorphic loci of the VEGF gene and its VEGFR2 receptor can have a significant effect on the response to anti-VEGF therapy of diabetic macular edema. The aim was to study the association of single nucleotide polymorphic loci of VEGF and VEGFR2 genes, as well as functional and anatomical parameters with response to ranibizumab therapy in patients with diabetic macular edema. Material and methods. The study includes 145 patients (145 eyes) with diabetic macular edema. All the patients are divided into 2 groups: a positive response (A) and no response to angiogenic therapy (B). The positive response (group A) was the presence of a reduction of at least 10 % of the foveolar thickness (FT) from the baseline according to the OST data. In addition, the response category was assessed: a good response (A1): a reduction in FT by more than 25 %, and an increase in MCHO by more than 5 letters of ETDRS and a poor response (group A2): a reduction in FT of 10-25 % and an increase in MCRI by less than 5 letters ETDRS. Genomic DNA was selected from leukocytes in venous blood, genotyping was performed by real-time PCR using probes of hydrolysing samples. Results. 45 (33.6 %) patients demonstrated a good response (group A1) to therapy and 89 (66.4 %) had a «bad» response (group A2). In group A1, the decrease in FT occurred on average by 25.61 %, the increase in MHC was 0.21 ± 0.07, while in group A2, the visual acuity increased by 0.05, with the thickness of the retina reduction by 74.1 μm (19, 5 %). Rs3025039 of the VEGFA gene is associated with the change in PTC ( p = 0.02). The decrease in the volume of the macula is associated with the allele C rs2010963 of the VEGFA gene ( p = 0.03). For the carriers of the T allele, the locus rs3025039 of the VEGFA gene, on the contrary, shows a lower value of the decrease in the volume of the macula ( p = 0.03). The patients with the T / T genotype of the polymorphic locus rs3025039 of the VEGFA gene statistically respond to anti-VEGF therapy significantly worse.
a:2:{s:4:"TEXT";s:267:"Andrey Gennad’yevich SHCHUKO1,2,3, Olesya Valer’yevna PISAREVSKAYA1, Tat’yana Nikolaevna YUR’YEVA1,2, Erzhena Munko-Zhargalovna BAL’ZHIROVA3, Tat’yana Nikolaevna FROLOVA1, Larisa Sergeevna KHLEBNIKOVA1";s:4:"TYPE";s:4:"html";} 1S. Fyodorov Eye Microsurgery Federal State Institution of Minzdrav of Russia, Irkutsk Branch 2Irkutsk State Medical Academy - Branch of Russian Medical Academy of Continuing Vocational Education of Minzdrav of Russia 3Irkutsk State Medical University of Minzdrav of Russia
Keywords: фемтосекундная хирургия, Smile, миопия высокой степени, femtosecond surgery, Smile, high degree of myopia
Purpose: to modify the calculated parameters of the refractive operation - extraction of the lenticle through small access (Smile), evaluate its safety and clinical effectiveness in correcting high-grade myopia. Material and methods. 34 patients (68 eyes) were operated by the modified Smile technology under local anesthesia. In all cases, patients had a high degree of myopia, in 37 % - in combination with astigmatism. Uncorrected visual acuity before surgery was on average 0.05 ± 0.11, Best corrected visual acuity was 0.94 ± 0.1, preoperative spherical refractive component -7.23 ± 0.75, cylindrical component -0.48 ± 0.59. During the surgery, in order to obtain the maximum possible refractive result according to the proposed method (patent No. 2018113414 of April 13, 2013), the standard parameters of the operation were changed: the thickness of the corneal flap was reduced to 100 μm, the neutral optical layer was 5 μm, the diameter of the optical zone depended on the residual thickness of the cornea, which should exceed 290 microns. The increase in corneal access was 15-20 degrees. Results. During the surgical intervention and in the postoperative period there were no complications. The next day after surgery, monocular uncorrected visual acuity in the distance in 73 % of patients was 0.8 and above, and in 41 % of cases it was equal to or exceeded 1.0. The spherical equivalent in the first day after the operation had a small hypermetropic shift, which was completely leveled by the year of observation. Conclusion. Using the proposed algorithm for calculating the refractive effect of the SMILE operation in high degree myopia allows obtaining a high refractive effect and avoiding possible complications.
Purpose: to study the etiological structure and incidence rate of various genesis optical neuropathies (ON) according to the own observation data. Material and methods. The study is based on the data analysis from a survey of 658 patients (982 eyes) with ON. The results of routine physical examination of all patients were analyzed to determine the genesis of ON. Results. The most common cases of ON were ischemic ON (31.2 % of all cases), as well as optic neuritis (18.3 % of cases). The anterior optic pathway tumor or infiltrative lesions were detected in 9.9 %, dysthyroid ON was found in 7.2 %. Acute and chronic ON with the optic nerve drusen accounted for 12.4 % of all cases of ON, was found in 60.5 % of all patients with the optic nerve drusen. Hereditary ON was found in 10 % of all cases of ON, toxic - in 4,3 % as a result of acute and chronic alcohol intoxication, chronic narcotic poisoning, drug poisoning. Traumatic ON was found in 6.7 % of all cases of ON. Conclusions. The causes of ON are diverse, vary from innate changes to diseases of the optic nerve as a result of serious therapeutic and neurosurgical pathology, which threaten not only the ophthalmologic, but also the life prediction. The patient thorough clinical study is required to determine the disease genesis at the time of ON symptoms identifying.
a:2:{s:4:"TEXT";s:226:"Anastasiya Konstantinovna LAZAREVA1, Ekaterina Arkad’yevna TASHLYKOVA1, Svetlana Vladimirovna AYDAGULOVA2, Ol’ga Nikolaevna KULESHOVA1,2, Valeriy Vyacheslavovich CHERNYKH1";s:4:"TYPE";s:4:"html";} 1S. Fyodorov Eye Microsurgery Federal State Institution of Minzdrav of Russia, Novosibirsk Branch 2Novosibirsk State Medical University of Minzdrav of Russia
Keywords: глаукома, склеральный лоскут, дренажная система глаза, световая микроскопия, электронная микроскопия, glaucoma, scleral sample, eye drainage system, light microscopy, electron microscopy
The study aim was to investigate structural peculiarities of sclera in different types of glaucoma, with an accent on changes of the eye drainage system. Materials and methods. Comparative descriptive case-control study of 103 patients (206 eyes) with different glaucoma types has been carried out: primary congenital glaucoma - 8 people, juvenile open-angle glaucoma - 10, primary open-angle glaucoma - 24, pseudoexfoliative - 35, pigmentary - 4, angle-closure -22. A pathomorphological study of 103 surgical scleral specimens has been conducted. Results. Distinctive changes of eye drainage system connective tissue were revealed according to the glaucoma type. Congenital glaucoma is characterized by an abundance of collector channels, a quantity of matrix-producing cells and explicit hydrophilic fiber compartment of sclera. Angle-closure glaucoma is defined by aseptic inflammation with polymorphic perivascular cell infiltrate and edema of eye drainage system endothelium as well. Structural equivalents of a long-lasting dystrophic process with a gradual destruction and reduction of cell elements are distinguishing features of primary open-angle glaucoma. Different glaucoma types vary in the explicitly and location of pigment imbibition of the drainage system components. Conclusion. Stereotypical and specific changes of eye drainage system were revealed in pathomorphogenesis of different types of glaucoma. These features determine the universal character and polymorphism of clinical aspects of glaucoma.
a:2:{s:4:"TEXT";s:164:"Svetlana Ivanovna ZHUKOVA1, Tat’yana Nikolaevna YURYEVA1,2, Irina Viktorovna POMKINA1, Anastasiya Sergeevna GRISHCHUK1,2";s:4:"TYPE";s:4:"html";} 1S. Fyodorov Eye Microsurgery Federal State Institution, Irkutsk Branch 2Irkutsk State Medical Academy of Postgraduate Education, Branch of the Russian Medical Academy of Continuing Vocational Education of Minzdrav of Russia
Keywords: ОКТ-диагностика глаукомы, ОКТ-ангиография, слой нервных волокон сетчатки, ганглиозный комплекс сетчатки, ретинальный кровоток, OCT-diagnosis of glaucoma, OCT-angiography, retinal nerve fiber layer, retinal ganglion cell complex, retinal blood flow
The purpose of the study was to evaluate the features of hemodynamics in patients with intraocular pressure (IOP) fluctuations, to reveal differential diagnostic criteria for adequate monitoring of glaucoma course according to optical coherence tomography (OCT) with the function of angiography. Material and methods. 25 patients (25 eyes) with hypertensive POAG were examined. The study included OCT of the retina and optic disk with the function of angiography. Patients of the clinical group underwent a non-penetrating fistulizing operation followed by laser goniopuncture. The examination was performed before the operation, in the early postoperative period, 1 and 3 months after the surgical intervention. The control group was 12 people (24 eyes) without ophthalmic pathology of the corresponding age and sex. Results and discussion. The obtained results testify to the role of regional hemodynamics in the formation of glaucoma neuroopticopathy. The revealed hemodynamic disturbances in the form of the decrease in the thickness of the choroid, decrease in the density of the radial peripapillary, superficial vascular plexus, and the corresponding glaucomatous changes in the optic disk, the layer of nerve fibers and the ganglionic retina complex, allow speaking about hypoperfusion caused by the decrease in the metabolic needs of atrophied tissue. Surgical interventions used in the treatment of patients with glaucoma lead to an improvement in blood flow parameters. Retinal and choroidal vessels respond differently to intraocular pressure fluctuations, which indicate different mechanism of adaptation of the eye’s vascular system in response to the change in the ophthalmotonus. In this connection, the question arises of the need to determine the individual intraocular pressure.
Elena Vladilenovna EGOROVA
S. Fyodorov Eye Microsurgery Federal State Institution of Minzdrav of Russia, Novosibirsk Branch
Keywords: катаракта, псевдоэксфолиативный синдром, факоэмульсификация, зонулопатия, cataract, pseudoexfoliation syndrome, phacoemulsification, zonulopathy
Traditional surgery of cataract in pseudoexfoliation syndrome (PEX) can be excessively aggressive and increase zonular instability. The main technological target of this surgery is reducing of a zonular stress at all stages and especially when removing the lens nucleus. Purpose was to develop an effective and safe technique for nucleus removal without rotating crystalline lens during phacoemulsification in PEX. Material and methods. 765 eyes with PEX were treated by phacoemulsification without nuclear rotation using original technique. The left paracentral oblique groove was made after capsulotomy and hydrodissection. Nucleus was divided by phaco tip and chopper. In right heminucleus a lateral deep groove was performed such way to create a big asymmetric wedge including central part of nucleus. This wedge was removed without rude manipulation and rotation. The remaining two peripheral segments were easily gripped and pull into pupil area for safe phacoemulsification. Results. In all cases this technique allowed for safe removing of the nucleus. Cataract surgery was finished without serious intraoperative complications. Conclusion. This method allows reducing intraoperative zonular stress and removing all nucleus fragments in the conditions of limited mydriasis at the maximum distance from the corneal endothelium. The rotationless technology of nucleous removal is effective and safe at cataract in PEX.
Research objective was to study the changes of intraocular pressure (IOP) in the postoperative period after a fistulizing antiglaucomatous operation by measurement with the method of a bidirectional cornea pneumoapplanation. Material and methods. Clinical trial was performed on the sampling from 50 patients (50 eyes) underwent antiglaucomatous operation - a trabeculectomy with basal iridectomy. The research by means of the biomechanical Ocular Response Analyzer was carried out before operation, in 1-2 months and in 6-12 months. The control group was made of 100 patients (100 eyes) with glaucoma against the background of hypotensive therapy. Results and discussion. The surgical glaucoma treatment led to IOP depression and normalization in all cases of research group. Level of the corneal compensated IOP before operation was in the range from 19.3 to 34.3 mmHg. The glaucoma surgical treatment led to the corneal compensated IOP expressed depression on average on 8.5 mmHg (34 % of initial). The augmentation of this indicator on average on 1,4 mmHg was revealed in the remote period. The corneal compensated IOP in this situation is more important indicator from the prognostic point of view. The revealed difference of IOP is similar to a tonometry according to Goldman emphasizes high probability of mistakes in this group of patients. Important feature of cornea bidirectional application is the possibility of the corneogram analysis and estimating the quality of IOP measurement.
Elina Eduardovna KAZARYAN, Darya Maksimovna SAFONOVA, Anna Georgievna MATYUSHCHENKO
Scientific Research Institute of Eye Diseases
Keywords: индивидуальная норма ВГД, переднезадняя ось глаза, внутриглазной кровоток, флоуметрия, глаукома, individual normal range of intraocular pressure, axial length of the eye, intraocular bloodflow, flowmetry, glaucoma
Aim: to demonstrate the benefit of individual normal range of intraocular pressure (inIOP) in early glaucoma diagnostics. Material and methods. The study included 40 patients (40 eyes) without established glaucoma diagnosis, no hypotensive regimen and average IOP level corresponding with the typical norm of ≤ 21 mm Hg, but at the same time exceeding inIOP level of ≤ 13.4 ± 4.1 mm Hg. All patients underwent visometry, biomicroscopy, tonometry, inIOP calculation, standard automated perimetry, retinal tomography. Follow-up period was 12 months. Results and discussion. At the baseline examination we revealed glaucomatous changes of morphofunctional parameters. After IOP level reduction to correspond with the individual normal range, all parameters were stabilized and showed no progression during the follow-up period. Conclusion. The method of individual normal range of intraocular pressure calculation may prove to be beneficial for early glaucoma diagnostics, as well as treatment tactics assessment.
The effectiveness of topical application of various drugs in ophthalmology is no more than 3 % due to the presence of anatomical and physiological barriers. The therapeutic effect accomplishment is possible with increasing concentration or multiplicity of drug use. The article presents the results of the development of a new type of therapeutic contact lens for the deposition of medications in order to shorten the periods of treatment and to obtain a result without repeated manipulation. The quantitative evaluation of the drug content in the lens is given. The dynamics of the release of the drug substance from the lens was determined by the method of spectrometry. Practically complete elimination of the drug from the soft contact lens (SCL) depot (both on the outer and inner surfaces of the lens) is observed on the 13-14 day. With the help of the chromatography method, the absence of drug diffusion from saturated SCL during storage in buffer solutions was proved. The design features of the lens: a depot with a drug on the external and / or internal surface of the therapeutic SCL allow for a dosed and directed effect on various structural components of the oculer surface. The presence of a transparent optical center allows maintaining high visual functions. If it is necessary to prolong therapy, it is possible to re-saturate the same SCL with a drug substance.
Purpose of the study was to assess the spectrum of molecular genetic disorders and the variety of clinical forms in patients with Stargardt disease. Material and methods. 56 patients aged 15-44 years who had been diagnosed with Stargardt disease in a history or at the time of the examination were included in the study. All patients underwent standard complete ophthalmic examination, as well as high-performance parallel sequencing of the coding sequences and adjacent areas of the introns of the ABCA4, ELOVL4, PROM1 and CNGB3 genes, as well as of the minor exons of the ABCA4 gene. Results. Mutations in one of 4 genes ( ABCA4, ELOVL4, PROM1 and CNGB3 ) were detected in 46 of 56 patients (82.1 %). An inverse correlation was found between the duration of the disease and the loss of visual acuity per year for the three groups ( k = -0.86, k = -0.93, k = -0.63, p < 0.05, respectively, with the debut of the Stargardt disease at 10 year, 11-30 year and > 31 year). A frequent mutation of the ABCA4 gene, p.G1961E was detected in 18 patients and in 83 % of cases (15 patients) is associated with a mild course of Stargardt disease. Complex mutation [p.L541P, p.A1038V] was detected in 17 patients, in 53 % (9 people) of cases was associated with more severe phenotype. However, in the compound heterozygous state with the missense mutation p.G1961E, a relatively mild course of the disease was observed. Conclusions. The loss of visual functions in Stargardt disease depends on the severity of the genetic defect in each case and on the disease’s duration in general.
Irina Gennadevna OLESHCHENKO1, Dmitriy Vladislavovich ZABOLOTSKIY2, Tatyana Nikolaevna YUREVA1,3, Marina Aleksandrovna GASPARYAN1, Yuliya Vladimirovna KURSAKOVA1
a:2:{s:4:"TEXT";s:388:"1Irkutsk Branch of Federal State Institution «Eye Microsurgery» n.a. S. Fyodorov of Minzdrav of Russia 2St. Petersburg State Pediatric Medical University of Minzdrav of Russia 3Irkustk State Medical Academy of Postgraduate Education - Affiliated Branch of Russian State Medical Academy of Continuous Postgraduate Education of Minzdrav of Russia";s:4:"TYPE";s:4:"html";}
Keywords: окислительно-восстановительный коэффициент, крылонебная блокада, вариабельность сердечного ритма, redox coefficient, spheropalatine blockade, heart rate variability
Purpose of the study was to evaluate the influence of the spheropalatine blockade on the state of redox potential in the surgical treatment of congenital cataract in children. Materials and methods. A prospective, nonrandomized study included 52 patients who underwent planned surgery. The first group ( n = 26) included patients underwent anesthesia based on sevorane in combination with spheropalatine blockade as a regional component; a distinctive feature of 2nd group ( n = 28) was the implementation of a retrobulbar blockade as a regional component. The integral index in the form of the redox coefficient (FORD / FORT) before and after operation was estimated. The characteristic of heart rate variability in the frequency domain with the analysis of low frequency / high frequency parameters and the stress index of autonomic system was studied. Results and discussion. The obtained results convincingly show that the use of the spheropalatine blockade is accompanied by adequate antinociceptive protection of the body at the stage of the operative intervention and in the early postoperative period. The positive effect of prolonged regional analgesia is due to blockade not only of nociceptive pathways, but also of sympathetic innervation due to the effect on the periarterial sympathetic plexus of the internal carotid artery. The antioxidative and antinociceptive efficacy of the spheropalatine blockade is consistent with the positive dynamics of clinical indices. Thus, spheropalatine blockade in the surgery of congenital cataract in children is not only a method of postoperative analgesia, but also a therapeutic factor that has a significant positive effect on the outcome of surgical treatment in general.
The problem of development and course of retinal venous occlusions (RVO) is relevant for today. The etiology of development of the RVO is multifaceted, and has not been fully studied. One of the main reasons for the decline in vision is the development of macular edema. The main problem in the treatment of macular edema is the difficulty in predicting increased visual acuity when disease is combined with retinal ischemia. One of the risk factors for the development of ischemia is endothelial dysfunction, whose important markers are endothelin-1 and hypoxia-inducible factors (HIF1α, HIF2α). Aim of the study was to evaluate the effect of the systemic level of endothelin-1 and hypoxia factors on the course of retinal venous occlusions. Material and methods. Content of the main markers of endothelial dysfunction (endothelin-1, HIF1α, HIF2α) was measured in 137 patients with RVO, among them 59 patients with central retinal vein occlusion and 78 - with central retinal vein branch occlusion. The average age of the patients was 73.35 ± 7.6 years. The level of markers of endothelial dysfunction was determined in serum by ELISA. Results and discussion. A statistically significant increase in endothelin-1 content in patients with optic nerve edema ( p = 0.018) was found. There were no statistically significant data on the effect on the course of the RVO of hypoxia factors HIF1 α and HIF2 α. Conclusion. Assessment of main markers indices of endothelial dysfunction can be used for understanding the etiology of RVO development and the correct tactics of the patients’ treatment forming.
Anzhella Zhanovna FURSOVA1,2, Olga Gennadyevna GUSAREVICH2, Mihail Sergeevich TARASOV1, Mariya Andreevna VASILYEVA1, Nadezhda Viktorovna CHUBAR1, Nelli Vasilyevna LITVINOVA1 1State Novosibirsk Regional Clinical Hospital 2Novosibirsk State Medical University of Minzdrav of Russia
Keywords: возрастная макулярная дегенерация, первичная открытоугольная глаукома, географическая атрофия, age-related macular degeneration, open-angle glaucoma, geographic atrophy
Nowadays age-related macular degeneration (AMD) and glaucoma are the main causes of the irreversible loss of sight in the developed countries. The analysis of 5000 of out-patient records of senior patients (over 50 years) has revealed glaucoma in 30.3 %, AMD in 37.94 %, and their combination in 20.3 % cases. In AMD, the structure signs of the dry form of the disease are diagnosed in 74 % of the cases, the geographical atrophy in 12 % and the wet atrophy - in 14 %. Primary open-angle glaucoma reduces risk of the wet AMD development while the tendency of early formation of the geographical atrophy of the retina increases and the share of the patients with the wet form goes down to 7 %. The article is intended to scrutinize the main pathogenetic mechanisms of the development of the diseases. Distinctions in the quantitative and qualitative components of biomarkers of the oxidative stress, endothelial dysfunction and inflammation are analysed as predictors of the start and development of comorbid pathology. This allows to identify the risk groups and therapy prospects. The vascular theory of pathogenesis related to the reduction of the perfusion of the head of the optic nerve, retina and chorioidea defines the diagnostic importance of the layer thickness parameters of the peripapillar nervous fibers and ganglion cell in differential diagnostics of this pathology. Application of anti-VEGF to patients with AMD and glaucoma is harmless and does not significantly influence the level of intraocular pressure and intraocular blood circulation. However, it requires careful monitoring of dynamics of the visual-functional and structural changes of the retina and optic nerve, as well as timely therapy correction. A combined course of the diseases with neurodegenerative nature of lesion leads to decrease of not only visual, but also cognitive functions, significantly influences of the senior age group patients’ quality of life and their adaptation in society.
Research purpose was to study the presence and local levels of inflammation markers (cytokines) in the anterior chamber and blood in patients with penetrating corneal wound. Material and methods. Thirty patients aged 24-55 years (mean age 31.2 ± 0.34 years) with penetrating corneal wound for 1-2 days from the moment of trauma were examined. The control group consisted of 30 patients aged 38-55 years (mean age 43.9 ± 0.21 years) hospitalized for surgical treatment - phacoemulsification of cataract without concomitant pathology. Anterior chamber aqueous humor sampling was made in all patients: in the experimental group during the primary surgical debridement of cornea penetrating wound, in the control group - during the phacoemulsification of cataract. Peripheral blood sampling also was made just before the operation. IL-1β, IL-1Ra, IL-4, IL-6, IFN-α, TNF-α levels, measured by EIA, and the expression of the herpes viruses (cytomegalovirus and herpes simplex virus I and II), measured by PCR, were studied. Results and discussion. The study showed that all the investigated cytokines were in the blood and in the AC aqueous humor of examined patients. High concentration of IL-1Ra, IL-1β, TNF-a и IL-4 was in the experimental group, as compared to control group. Systemic innate immunity was activated in the experimental group and was significantly higher in the C-reactive protein index in patients of the experimental group as compared to control group. Conclusion. An acute period of eye injury is accompanied by a local and systemic increase in proinflammatory and anti-inflammatory cytokines, which indicates an imbalance in the regulation of immune inflammation, as the basis for the implementation of immuno-inflammatory complications.
Polina Mikhaylovna BALASHOVA, Elena Vladimirovna KOZINA, Vladimir Trofimovich GOLOLOBOV, Merine Khachikovna ANTONYAN, Irina Andreevna KOKH
Krasnoyarsk State Medical University n.a. prof. V.F. Voino-Yasenetsky of Minzdrav of Russia
Keywords: первичная энуклеация, эвисцерация, посттравматическая энуклеация глаза, глазной травматизм, офтальмотравматология, анофтальм, primary enucleation, evisceration, posttraumatic enucleation of the eye, eye traumatism, ophthalmotravmatology, anophthalmus
The purpose of the work is to evaluate the characteristics of primary posttraumatic eyeball removal in the adult population of the Krasnoyarsk Territory. Material and methods. The analysis of 87 patients’ medical documents from the Krasnoyarsk Regional Ophthalmologic Clinical Hospital has been carried out since 2003 till 2016; the primary posttraumatic eyeball removal was performed. Gender, age, place of residence, social and labor status of patients, the type and nature of the injuries that caused the eyeball removal as a primary surgical intervention have been taken into account. Results and discussion. Between 2003-2016 the proportion of primary posttraumatic removal of the eyeball was ranged from 9 % to 42.9 % of all eye removal procedures due to trauma., Their were 73 (83.9 %) men and 14 (16.1 %) women among 87 patients aged 18-88 years. Distribution by social status came up to unemployed citizens (48.3 %), officially employed - 28.8 % and pensioners - 22.9 %. Home accident trauma was more common (68.9 % of cases), criminal (24.1 %) and industrial (6.9 %) injuries were less often. The period from the eye injury moment till its removal was 0-90 days. The main causes of primary posttraumatic eye removal were eyeball destruction in 65.5 % of cases, panophthalmia was in 19.6 %, eye painful subatrophy - in 14.9 % of cases. Conclusion. Primary posttraumatic eyeball removal can be considered as a model of the entire population of post-traumatic enucleations. Specific gravity (23.9 %), increase in the frequency of primary post-traumatic eyeball removal can influence on the waiting time for traumatic enucleation in general. In the overwhelming number of injured patients, the primary removal of the eyeball is the consequence of the injury severity, in 34.5 % of cases it is due to the imperfection of medical care at various stages of its delivery.
In recent years, the approaches to assessing results have been changed in both clinical and real life trials with the introduction of Aflibercept to clinical practice. In most countries, ranibizumab and aflibercept are licensed for the treatment of neovascular age-related macular degeneration (AMD). The assessment of the treatment effectiveness and economic cost was carried out within the frame of different clinical trials with existing strict limitations. The article reviews the results of studies conducted in various clinical trials. Data on long-term follow-up after anti-VEGF therapy for neovascular AMD form, especially in real-life studies, are limited. In the framework of the HORIZON study, representing an extended four-year follow-up of ANCHOR and MARINA patients, the gradual reduction in visual acuity has been revealed in the first 2 years of follow-up period. The re-examination of 10 % of patients from the initial ANCHOR and MARINA studies has been described in the SEVEN-UP study; herewith the decrement in visual activity has been detected after 7 years on the beginning of the clinical studies examination (loss of 8.6 letters against initial letter). The data obtained can not be directly transmitted into routine clinical practice, due to the patients’ inclusion and exclusion Criterion presence, protocols for the introduction of drugs, etc. A study of the therapy’s effectiveness and economic cost in real time allows optimizing the treatment of patients with neovascular AMD.
