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Physicochemical aspects of allanite flotation

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Journal of Rare earths 2014年第5期32卷 476-486页

作者： Adam Jordens Chris Marion olga Kuzmina Kristian e.Waters Department of Mining and Materials engineering McGill University

This paper investigated the physicochemical properties of allanite, a Re-silicate, by measuring zeta potential in the absence and presence of three different flotation collectors （benzohydroxamic acid, sodium oleate and dodecylamine）. This data was then verified by microflotation experiments and with bubble-particle attachment pictures. The investigated properties of allanite were com- pared to those of quartz, a common gangue mineral in many Re deposits. The results of this work indicated that only dodecylamine was able to achieve a selective separation of allanite and quartz. This was accomplished by lowering the dodecylamine dosage so that only quartz was recovered by microflotation.

关键词： allanite flotation surface chemistry zeta potential bubble-particle attachment rare earths

NeCAB family of neuronal calcium-binding proteins in health and disease

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Neural Regeneration Research 2025年第5期20卷 1236-1243页

作者： Diones Bueno Michael K.e.Schafer Sudena Wang Michael J.Schmeisser Axel Methner Institute for Molecular Medicine University Medical Center of the Johannes Gutenberg-UniversityMainzGermany Department of Anesthesiology University Medical Center of the Johannes Gutenberg-UniversityMainzGermany Institute of Anatomy University Medical Center of the Johannes Gutenberg-UniversityMainzGermany

The N-terminal eF-hand calcium-binding proteins 1–3(NeCAB1–3) constitute a family of predominantly neuronal proteins characterized by the presence of at least one eF-hand calcium-binding domain and a functionally less well characterized C-terminal antibiotic biosynthesis monooxygenase domain. All three family members were initially discovered due to their interactions with other proteins. NeCAB1 associates with synaptotagmin-1, a critical neuronal protein involved in membrane trafficking and synaptic vesicle exocytosis. NeCAB2 interacts with predominantly striatal G-protein-coupled receptors, while NeCAB3 partners with amyloid-β A4 precursor protein-binding family A members 2 and 3, key regulators of amyloid-β production. This demonstrates the capacity of the family for interactions with various classes of proteins. NeCAB proteins exhibit distinct subcellular localizations: NeCAB1 is found in the nucleus and cytosol, NeCAB2 resides in endosomes and the plasma membrane, and NeCAB3 is present in the endoplasmic reticulum and Golgi apparatus. The antibiotic biosynthesis monooxygenase domain, an evolutionarily ancient component, is akin to atypical heme oxygenases in prokaryotes but is not wellcharacterized in vertebrates. Prokaryotic antibiotic biosynthesis monooxygenase domains typically form dimers, suggesting that calcium-mediated conformational changes in NeCAB proteins may induce antibiotic biosynthesis monooxygenase domain dimerization, potentially activating some enzymatic properties. However, the substrate for this enzymatic activity remains uncertain. Alternatively, calcium-mediated conformational changes might influence protein interactions or the subcellular localization of NeCAB proteins by controlling the availability of protein–protein interaction domains situated between the eF hands and the antibiotic biosynthesis monooxygenase domain. This review summarizes what is known about genomic organization, tissue expression, intracellular localization, interac

关键词： calcium eF hand mitochondria nervous system signal transduction

Nonconservative mechanical systems with nonholonomic constraints

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Science China(Physics,Mechanics & Astronomy) 2012年第8期55卷 1475-1484页

作者： KRUPKOV olga Department of Mathematics Faculty of Science The University of Ostrava 30. dubna 22 701 03 Ostrava Czech Republic Department of Mathematics and Statistics La Trobe University Melbourne Victoria 3086 Australia

A geometric setting for generally nonconservative mechanical systems on fibred manifolds is proposed. emphasis is put on an explicit formulation of nonholonomic mechanics when an unconstrained Lagrangian system moves in a generally non-potential force field depending on time, positions and velocities, and the constraints are nonholonomic, not necessarily linear in velocities. equations of motion, and the corresponding Harniltonian equations in intrinsic form are given. Regularity conditions are found and a nonholonomic Legendre transformation is proposed, leading to a canonical form of the nonholonomic Hamiltonian equations for nonconservative systems.

关键词： nonconservative mechanical systems equations of motion Hamiltonian equations nonholonomic constraints Chetaevequations Hamiltonian equations for nonconservative nonholonomic systems

Paleoclimate Study of Mountain ecosystems by Multiple Group Biological Analysis

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Journal of Mountain Science 2011年第1期8卷 24-36页

作者： Marina SKRYPNIKOVA olga USPeNSKAYA olga KHOKHLOVA Dokuchaev Soil Science Institute of Russian Academy of Agricultural Sciences Pyzhevsky Lane7Moscow109017Russia Vegetable Institute of Russian Academy of Agricultural Sciences h.500v.VereaRamenskii distMoscow region140153Russia Institute of Physical Chemical and Biological Problems in Soil Science of RASUlitsa Institutskaya2PushchinoMoscow region142290Russia

Methodological problems of climatic reconstruction for different periods of Holocene are discussed on the basis of a multiple group biological analysis on peat-sapropel sediments. The possibility of biological analysis is exemplified by the paleoclimatic reconstruction for Carpathian and Altai Mountain ranges. For the ＂Skolevsky Beskidy＂ national park of Carpaty the paleoclimatic scenarios have been drown up aiming at the more precise definition of climatic conditions for the period of mass mountain slope terracing. The stability of terrace systems of various designs in the current climatic conditions has been assessed. It is shown that during periods of humid climate the terraces, whose designs have been focused on drainage, were built. In periods of dry and warm climate the terrace systems capable of accumulating water were built. Both these types of terrace systems are destroyed in nowadays. Only those terrace systems are stable which were adjusted by their builders to contrast variations of precipitation. For Western Altais the paleoclimatic scenario has been done to forecast the safety of the Bronze Age kurgans （burial earth mounds） with permafrost inside the construction. In the Altay region during the Holocene it has revealed two periods of sharp cooling, the peaks of which occurred in the intervals 4500- 4300 and 2500-2300 years pronounced climatic drying ago, and two periods of 4900-4700 and 130-70 years ago. Depletion of the algae composition in the layer corresponding to the last period of drying climate indicates a very sharp change in the parameters of moisture and turning the lake into a dry swamp. Periods of cold weather may have contributed to the formation of special ritual traditions of the Sakan tribes that require the frozen ground to bury the dead. The later climate fluctuations identified have not affected the safety of permafrost in burial mounds constructed in the V-III cc BC.

关键词： Climatic reconstruction Complex group biological analysis of peat-sapropel sediments Paleopedology Soil evolution Holocene

Deciphering tau-related dementia using human iPSC lines: electrophysiological perspectives of future studies

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Neural Regeneration Research 2022年第12期17卷 2672-2674页

作者： olga Kopach Queen Square Institute of Neurology University College LondonLondonUK

To date,no disease-modifying treatment or cure is available for *** disorder is becoming more common as the global population *** has been over several decades of extensive research focusing on how the pathology develops and progresses causing memory loss,brain damage,and eventually death-it provides the field with a deep understanding of what proteins,peptides,and signaling molecules contribute to neurodegeneration at the molecular,genetic,and cellular *** problem is,however,that there is a wide range of dementia types.A given disease can span heterogeneous clinical syndromes with diverse symptomatology,no matter whether it is“senile dementia”or an early-onset form;moreover,it encompasses the mixed features of many syndromes in later stages of the disease.

关键词： senile pathology eventually

Searching for the brightest stars in galaxies outside the Local Group

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Research in Astronomy and Astrophysics 2021年第4期21卷 264-270页

作者： Nikolay Tikhonov olga Galazutdinova olga Sholukhova Antoniya Valcheva Petko Nedialkov olga Merkulova Special Astrophysical Observatory Nizhnij ArkhyzKarachai-Cherkessian RepublicRussia 369167 Department of Astronomy Sofia University1504 Sofia15 Tsar Osvoboditel Blvd.SofiaBulgaria Astronomical Institute St.Petersburg State UniversityUniversitetskii pr.28St.Petersburg198504 Russia

This paper introduces a technique for searching for bright massive stars in galaxies beyond the Local *** search for massive stars,we processed the results of stellar photometry from the Hubble Space Telescope(HST)images using the DAOPHOT and DOLPHOT *** results of such searches are demonstrated with examples of the galaxies DDO 68,M94 and NGC *** the galaxy DDO 68,the LBV star changes its brightness,and massive stars in M94 can be identified by excess in the Ha *** the galaxy NGC 1672,we measure the distance for the first time by the TRGB method,which enabled determining the luminosities of the brightest stars,likely hypergiants,in the young star formation *** far,we have performed stellar photometry on HST images of 320 northern sky galaxies located at a distance less than 12 *** allowed us to identify 53 galaxies with probable *** photometric and spectral observations of these galaxies are planned to search for massive stars.

关键词： stars:massive stars:variables:LBV galaxies:individual:M94 DDO 68 NGC 1672

U-Blacks Mineralization in Sandstone Uranium Deposits

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Journal of earth Science 2022年第2期33卷 308-316页

作者： olga A.Doynikova Institute of Ore Deposits Geology PetrographyMineralogy and Geochemistry Russian Academy of ScienceMoscow 119017Russia

Ores of infiltration sandstone-hosted uranium deposits in the sedimentary cover are ubiquitous composed of dispersed soot powder mineralization of black,brownish-black *** studies of such loose U-ores by analytical transmission electron microscopy(ATeM)proved their polymineral *** blacks are composed by at least three different U-mineral forms:oxide(uraninite),silicate(coffinite)and phosphate(ningyoite)which are present in various proportions of ore *** high dispersed friable uranium formations are difficult to diagnose by traditional mineralogical methods(optical,XRD,IR and X-ray spectroscopy,etc.)which analyze total sample composition(phases mixture);their results characterize the dominant sample phase,omitting both sharply subordinate and X-ray amorphous *** research results are based on ATeM methods(SAeD+eDS),which are optimal for crystallochemical diagnostics in the mineralogical study of such uranium *** article presents the diagnostic characteristics under electron microscope(eM)of uranous minerals from different sandstone deposits with their origin being discussed.

关键词： uranous minerals uraninite coffinite ningyoite biogenic nature U-deposit ore deposit geology

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The forecast of fire impact on Pinus sylvestris renewal in southwestern Siberia

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Journal of Forestry Research 2021年第5期32卷 1911-1919页

作者： Stanislav NSannikov Nelly SSannikova Irina VPetrova olga e.Cherepanova Botanical Garden of the Ural Branch of Russian Academy of Science 202a8 Marta St.Yekaterinburg 620144Russia

Simulation of fire impact on forest floor renewal in pine forests was based on predictions for 2100 by the Canadian Climate Centre for increase in temperatures of by4.5℃and total precipitation by 14%in the West Siberian pre-forest-steppes and empirical regression relationships between them and the degree of burnt forest floor,as well as amount of Pinus sylvestris *** was predicted that by 2100,pine regeneration on fire prone sites under the canopy of the dominant forest type will increase by 29-54%compared to the 1980 s but on adjacent open sites,regeneration will decrease twice as *** means that the regeneration potential and pine population stability in pre-forest-steppes will become as poor as it is today.

关键词： Fire Forecast Stability Population Mathematical model Seeds Imitation model Undergrowth

Chemical geothermometry:application to mud volcanic waters of the Caucasus region

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Frontiers of earth Science 2020年第4期14卷 738-757页

作者： olga e.Kikvadze Vasilii Yu.Lavrushin Boris G.Polyak Geological Institute Russian Academy of SciencesMoscow119017Russia Siberian Branch of the RAS V.S.Sobolev Institute of Geology and MineralogyNovosibirsk630090Russia

The generation temperatures of gas-water fluids released from mud volcanoes in different provinces of the Caucasian region have been constrained using Mg/Li(T_(Mg/Li))chemical *** volcanic fluids in the Taman Peninsula(Kerch-Taman mud volcanic province)were generated at temperatures(T_(Mg/Li))from 41℃ to 137℃.The depths of the respective mud reservoirs estimated from T_(Mg/Li) values and local geothermal gradient are in a range of 1.0 to 3.4 km which spans the Maykop Formation of marine *** the South Caspian province,the T_(Mg/Li) values of waters vary from 18℃ to 137℃ and the respective root depths HMg/Li of mud volcanoes range from∼0.85 to 6.5 *** obtained T_(Mg/Li) values for the analyzed mud volcanic waters from Caucasian provinces are in positive correlation with HCO3^(−)contents and water oxygen isotope compositions(δ^(18)OH_(2)O andΔδ^(18)OH_(2)O)and in high negative correlation with Cl^(−).The increase of T_(Mg/Li) toward the Greater Caucasus Range,as well as the lateral T_(Mg/Li) patterns in the Taman and South Caspian mud volcanic provinces,support the idea that mud volcanic fluids generate at temperatures increasing progressively toward the Alpine orogenic belt.

关键词： mud volcano fluid chemical geothermometry stable isotopes Caucasus region