The paper is devoted to a complete characterization of proper closed invariant subspaces of the generalized backward shift operator (Pommiez operator) in the Fréchet space of all holomorphic ...functions in a simply connected domain \Omega \ni 0 in the complex plane. In the case when the function that generates this operator does not have zeros in \Omega, all such subspaces are finite-dimensional. If in addition \Omega coincides with the entire complex plane, then the generalized backward shift operator under consideration is unicellular. If this function has zeros in \Omega, then the above family of invariant subspaces splits into two classes: the first consists of finite-dimensional subspaces, and the second of infinite-dimensional ones.
Rare sugars attract more and more attention as safe low-calorie sweeteners and functional compounds in the food, pharmaceutical and medical industries. D-Allulose, first discovered in wheat over 70 ...years ago, has significant application potential but its widespread use is limited by high production costs. The epimerization reactions of available sugars resulting in D-allulose production are catalyzed by enzymes of the epimerase group, ketose-3-epimerases. The key tasks of the study of the ketose-3-epimerases family enzymes are defining the exact mechanisms of their action, the improvement of enzymatic activity and stability in order to achieve a higher efficiency of D-allulose production. The review summarizes the latest innovations in the use of ketose-3-epimerases and optimization of D-allulose manufacturing processes. The structural features of the main enzymes explored in the production of the rare sugar, molecular modifications of biocatalysts, and prospects for the practical use of discussed in this work enzyme pathways are also considered.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Physicochemical properties and vertical distribution patterns of clay minerals in the weakly differentiated permafrost-affected soils of the Kolyma Lowland have been studied. These soils are ...developed under conditions of cold ultracontinental climate within a broad range of landscapes: coastal marsh, alas meadows on the plain composed of the ice complex deposits, and typical northern taiga. Despite the fact that weathering processes are weakly developed at high latitudes, certain features of pedogenic transformation of the initial chlorite–illite association have been identified. These are the presence of (i) vermiculite in the acidic soil horizons of the alas meadow and zonal northern taiga landscapes and (ii) iron hydroxide (lepidocrocite) in the profile of the marsh meadow soil. The soils of zonal taiga woodland are classified as cryozems according to the new Russian profile-genetic soil classification system; their classification position does not cause doubt. Oppositely, the classification of weakly differentiated and differently gleyed soils of intrazonal landscapes (alases and marsh meadows) is open to argument and should be further clarified.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The review is compiled on the basis of the results of operation of the total ozone (TO) monitoring system in Russia and neighboring countries which functions in the operational mode at Central ...Aerological Observatory. The monitoring system uses data from the national network equipped with M-124 filter ozonometers being under the methodological supervision of Main Geophysical Observatory. The quality of the entire system functioning is operationally controlled using the OMI satellite equipment observations (NASA, USA). Basic TO observation data are generalized for each month of the fourth quarter of 2022, for the fourth quarter, and for the whole year. Data of routine observations of surface ozone in the Moscow region are also presented.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Planctomycetes are common inhabitants of northern wetlands. In the present work, a novel representative of the genus
Gemmata
, strain G18
T
, was isolated from a fen of northwestern Russia. The cells ...were spherical, occurring singly or in small groups, motile in the exponential growth phase. Strain G18
T
was a chemoorganotrophic, psychrotolerant microorganism, with growth optima at pH 7.0 and 15‒20°C. The preferred growth substrates were polysaccharides pectin, xylan, lichenan, xanthan gum, and PhytaGel. Among the taxonomically characterized representatives of this order, highest levels of 16S rRNA gene sequence similarity (95.7–98.9%) were observed with the freshwater planctomycete
Gemmata obscuriglobus
DSM 5831
T
and “
Gemmata massiliana
” IIL30. The genome of strain G18
T
consisted of a 9.23-Mb chromosome, containing 7631 protein-coding genes and 3 copies of the rRNA operon (the 5S, 16S, and 23S rRNA genes). The G + C content of the chromosomal DNA was 65 mol %. According to ANI, the values of similarity between strain G18
T
and other
Gemmata
strains were 86.0% (“
G. massiliana
” IIL10) and 79.7% (
G. obscuriglobus
DSM 5831). Based on the results of comparative phenotypic, physiological, and phylogenomic analyses, we propose to classify strain G18
T
(=KCTC 82682 = VKM B-3541
T
) as belonging to a novel species of the genus
Gemmata
,
Gemmata palustris
sp. nov.
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A new Vasilinovskoe Pt–Au–Pd occurrence found near the settlement of Kharp (Yamal-Nenets Autonomous Okrug) is described for the first time. The occurrence is related to amphibolized gabbroids and ...subordinate pyroxenites of the mostly Late Ordovician Kershor complex. These rocks host mineralization zones with a visible thickness of 0.5–50 m and 3–5 vol % (rarely more) of sulfides. The feldspar–quartz, epidote, and other veinlets are often present in areas with dispersed or small-pocket sulfide dissemination. According to the fire assay analysis, the Pd, Au, and Pt contents of sulfide-rich samples weighing 0.5–1.0 kg from low-sulfide zones reach 1.4, 0.8, and 0.2 g/t, respectively. The PGE minerals include abundant micron-sized Pd tellurides: merenskite PdTe
2
, temagamite Pd
3
HgTe
3
, kotulskite PdTe, and other noble metal compounds: sadberiite PdSb, arsenopalladinite Pd
8
(As,Sb)
3
, and others. In addition to these Pd minerals, the magnetite–chalcopyrite–pyrite assemblage contains microinclusions of native silver, native bismuth, and native tin. The late polysulfide–feldspar–carbonate–quartz assemblage hosts Au and Ag tellurides, native gold (including mercurious), Se-bearing argentite, and greenockite. The formation of noble metal assemblages is related to late magmatic processes, as well as the redistribution of ore matter by later magmatic hydrothermal fluids down to a temperature of ~250°С; the pressure decreased from ~0.9‒1.3 to ~0.4‒0.5 kbar.
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Physicochemical properties and vertical distribution patterns of clay minerals were studied in the permafrost-affected soils from the tundra and sub-tundra larch open woodland of Tit-Ary Island. This ...unique complex is located in the Lena River Delta, Republic of Sakha (Yakutia). Despite the small size of the island and the fact that permafrost is close to the surface, several variants of pedogenesis determine the soil diversity in this area. The soils are characterized by various degrees of gleyic and stagnic properties due to sandy or loamy texture and location in the landscapes (top of the hills and steep or gentle slope). Mineral associations in the studied profiles are similar and are characterized by the predominance of two components: chlorite and illite. Iron hydroxide—lepidocrocite—occurs at the boundary of permanently frozen ground in the profile with pronounced spodic features. Smectitic clay identified in both horizons of this permafrost affected soil, as well as lepidocrocite, can be attributed to the result of modern pedogenesis.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Herein we provide information on the integrated geological, geophysical, sedimentological, and hydrophysical investigations and passing meteorological and biological observations, as well as on the ...surface hydrobiological sampling in the Tropical Atlantic during cruise 60 (leg 2) of the R/V
Akademik Ioffe
in December 2021 to February 2022. The preliminary scientific results are discussed.
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Experimental syntheses of two iron polyhydrides FeH
x
(I) and FeH
x
(II) have been carried out in diamond anvil cells by laser heating of metallic iron to temperatures of about 700 and 2000 K at ...pressures of 178 and 195 GPa, respectively. The initial sample is an iron plate enriched in the Fe-57 Mössbauer isotope placed in ammonia borane (BH
3
NH
3
). The electronic properties of FeH
x
compounds have been studied by measuring the electrical resistance
R
(
T
) at high pressures (180–216 GPa) in the temperature range of ~8–300 K. Based on the obtained
R
(
T
) data, two superconducting phases of FeH
x
compounds with the maximum critical transition temperatures
T
c
≈ 25.0 and 27.7 K have been identified. It has been found that with increasing pressure, the temperature
T
c
in both hydrides increases linearly with the coefficients
dT
c
/
dP
~ 0.063 ± 0.001 K/GPa and 0.056 ± 0.003 K/GPa for the FeH
x
(I) and FeH
x
(II) phases, respectively. Superconductivity in iron hydrides revealed by the measured resistance
R
(
T
) has been confirmed by a number of additional methods.
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Hepatitis C virus (HCV) is a highly pathogenic human virus associated with liver fibrosis, steatosis, and cancer. In infected cells HCV induces oxidative stress. Here, we show that HCV proteins core, ...E1, E2, NS4B, and NS5A activate antioxidant defense Nrf2/ARE pathway via several independent mechanisms. This was demonstrated by the analysis of transient co-expression in Huh7 cells of HCV proteins and luciferase reporters. Expression, controlled by the promoters of stress-response genes or their minimal Nrf2-responsive elements, was studied using luminescence assay, RT-qPCR and/or Western-blot analysis. All five proteins induced Nrf2 activation by protein kinase C in response to accumulation of reactive oxygen species (ROS). In addition, expression of core, E1, E2, NS4B, and NS5A proteins resulted in the activation of Nrf2 in a ROS-independent manner. The effect of core and NS5A was mediated through casein kinase 2 and phosphoinositide-3 kinase, whereas those of NS4B, E1, and E2, were not mediated by either PKC, CK2, PI3K, p38, or ERK. Altogether, on the earliest stage of expression HCV proteins induced a strong up-regulation of the antioxidant defense system. These events may underlie the harmful effects of HCV-induced oxidative stress during acute stage of hepatitis C.
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