68 research outputs found

    Weedy plants at Ugolnye Kopi Village, Anadyrsky District, Chukotka Autonomous Area

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    The village of Ugolnye Kopi (Anadyrsky District, Chukotka Autonomous Area, Russia) is located in the left-bank estuary part of the Anadyr River, on the shore of the Anadyr Firth, overlooking the Bering Sea. Despite a relatively low latitude (64°44’N), more suitable for the development of boreal vegetation, the effect of cold-sea air masses on the environments of this locality forms vegetation more typical of the Subarctic tundra subzone. Penetration of adventive plant species, human satellites, into this area is very limited. There has been no previous information about the composition of the synanthropic flora at Ugolnye Kopi Village. Some data concerning adventive plants in the vicinity of the town of Anadyr were available in the review published by N. A. Sekretareva and A. A. Korobkov from the Komarov Botanical Institute. A survey conducted in August 2021 resulted in identifying an adventive component of the flora in the vicinity of Ugolnye Kopi, consisting of 44 vascular plant species. A key role in the village’s spontaneous landscaping has been played by 18 species of apophytes that arrived and settled there from the surrounding vegetation. Seven more apophytic species came to the village from more distant places of Chukotka. The usual synanthropic component, long ago acclimatized in Chukotka, is represented by 7 species: Hordeum jubatum, Chenopodium prostratum, Descurainia sophioides, Erysimum boreale, E. cheiranthoides, Taraxacum ceratophorum, and T. officinale s.l. Invasive species alien to this area are Elytrigia repens, Puccinellia borealis, Oberna behen, Stellaria media, Boechera pendula, Capsella bursa-pastoris, Trifolium repens, Lappula anisacantha, L. heteracantha, Lepidotheca suaveolens, Senecio dubitabilis, and S. vulgaris

    <i>N,N</i>-bis-(dimethylfluorosilylmethyl)amides of <i>N</i>-organosulfonylproline and sarcosine: synthesis, structure, stereodynamic behaviour and <i>in silico</i> studies

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    (O→Si)-Chelate difluorides R3R2NCH(R1)C(O)N(CH2SiMe2F)2 (9a–c, R1R2 = (CH2)3, R3 = Ms (a), Ts (b); R1 = H, R2 = Me, R3 = Ms (c)), containing one penta- and one tetracoordinate silicon atoms were synthesized by silylmethylation of amides R3R2NCH(R1)C(O)NH2, subsequent hydrolysis of unstable intermediates R3R2NCH(R1)C(O)N(CH2SiMe2Cl)2 (7a–c) into 4-acyl-2,6-disilamorpholines R3R2NCH(R1)C(O)N(CH2SiMe2O)2 (8a–c) and the reaction of the latter compounds with BF3·Et2O. The structures of disilamorpholines 8a,c and difluoride 9a were confirmed by an X-ray diffraction study. According to the IR and NMR data, the O→Si coordination in solutions of these compounds was weaker than that in the solid state due to effective solvation of the Si–F bond. A permutational isomerisation involving an exchange of equatorial Me groups at the pentacoordinate Si atom in complexes 9a–c was detected, and its activational parameters were determined by 1H DNMR. In silico estimation of possible pharmacological effects and acute rat toxicity by PASS Online and GUSAR Online services showed a potential for their further pharmacological study

    Characteristic of the active substance of the Saccharomyces cerevisiae preparation having radioprotective properties

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    The paper describes some biological features of the radioprotective effect of double-stranded RNA preparation. It was found that yeast RNA preparation has a prolonged radioprotective effect after irradiation by a lethal dose of 9.4 Gy. 100 % of animals survive on the 70th day of observation when irradiated 1 hour or 4 days after 7 mg RNA preparation injection, 60 % animals survive when irradiated on day 8 or 12. Time parameters of repair of double-stranded breaks induced by gamma rays were estimated. It was found that the injection of the RNA preparation at the time of maximum number of double-stranded breaks, 1 hour after irradiation, reduces the efficacy of radioprotective action compared with the injection 1 hour before irradiation and 4 hours after irradiation. A comparison of the radioprotective effect of the standard radioprotector B-190 and the RNA preparation was made in one experiment. It has been established that the total RNA preparation is more efficacious than B-190. Survival on the 40th day after irradiation was 78 % for the group of mice treated with the RNA preparation and 67 % for those treated with B-190. In the course of analytical studies of the total yeast RNA preparation, it was found that the preparation is a mixture of single-stranded and double-stranded RNA. It was shown that only double-stranded RNA has radioprotective properties. Injection of 160 μg double-stranded RNA protects 100 % of the experimental animals from an absolutely lethal dose of gamma radiation, 9.4 Gy. It was established that the radioprotective effect of double-stranded RNA does not depend on sequence, but depends on its double-stranded form and the presence of “open” ends of the molecule. It is supposed that the radioprotective effect of double-stranded RNA is associated with the participation of RNA molecules in the correct repair of radiation-damaged chromatin in blood stem cells. The hematopoietic pluripotent cells that have survived migrate to the periphery, reach the spleen and actively proliferate. The newly formed cell population restores the hematopoietic and immune systems, which determines the survival of lethally irradiated animals

    International longitudinal registry of patients with atrial fibrillation and treated with rivaroxaban: RIVaroxaban Evaluation in Real life setting (RIVER)

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    Background Real-world data on non-vitamin K oral anticoagulants (NOACs) are essential in determining whether evidence from randomised controlled clinical trials translate into meaningful clinical benefits for patients in everyday practice. RIVER (RIVaroxaban Evaluation in Real life setting) is an ongoing international, prospective registry of patients with newly diagnosed non-valvular atrial fibrillation (NVAF) and at least one investigator-determined risk factor for stroke who received rivaroxaban as an initial treatment for the prevention of thromboembolic stroke. The aim of this paper is to describe the design of the RIVER registry and baseline characteristics of patients with newly diagnosed NVAF who received rivaroxaban as an initial treatment. Methods and results Between January 2014 and June 2017, RIVER investigators recruited 5072 patients at 309 centres in 17 countries. The aim was to enroll consecutive patients at sites where rivaroxaban was already routinely prescribed for stroke prevention. Each patient is being followed up prospectively for a minimum of 2-years. The registry will capture data on the rate and nature of all thromboembolic events (stroke / systemic embolism), bleeding complications, all-cause mortality and other major cardiovascular events as they occur. Data quality is assured through a combination of remote electronic monitoring and onsite monitoring (including source data verification in 10% of cases). Patients were mostly enrolled by cardiologists (n = 3776, 74.6%), by internal medicine specialists 14.2% (n = 718) and by primary care/general practice physicians 8.2% (n = 417). The mean (SD) age of the population was 69.5 (11.0) years, 44.3% were women. Mean (SD) CHADS2 score was 1.9 (1.2) and CHA2DS2-VASc scores was 3.2 (1.6). Almost all patients (98.5%) were prescribed with once daily dose of rivaroxaban, most commonly 20 mg (76.5%) and 15 mg (20.0%) as their initial treatment; 17.9% of patients received concomitant antiplatelet therapy. Most patients enrolled in RIVER met the recommended threshold for AC therapy (86.6% for 2012 ESC Guidelines, and 79.8% of patients according to 2016 ESC Guidelines). Conclusions The RIVER prospective registry will expand our knowledge of how rivaroxaban is prescribed in everyday practice and whether evidence from clinical trials can be translated to the broader cross-section of patients in the real world

    Poa lanata Scribn. & Merr.

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    4. Poa lanata Scribn. & Merr. In Contributions from the United States National Herbarium 13 (3): 72, table 16 (1910). — Tzvelev, Arctic Flora of the USSR 2: 126 (1964); Grasses of the USSR: 453 (1976). TYPUS. — " Aleuten Islands, Dutch Harbor, spent a few hours ascending the mountain (about 1800 ft high) near the wharf, 17 Jul 1899, F.V. Coville et T.H. Kearney, No 2191" (US-376421) (Soreng et al. 2003: 543). — Sandy and pebble banks of rivers and streams: Kol. GENERAL DISTRIBUTION. — Rus. Far East, N Amer.Published as part of Olovona, Marina V. & Nikolin, E. G., 2018, Bluegrasses (Poa L., Poaceae) of Sakha (Yakutia) Republic, an annotated checklist, pp. 89-102 in Adansonia (3) (3) 40 (7) on page 91, DOI: 10.5252/adansonia2018v40a7, http://zenodo.org/record/460208

    Distribution of some woody species at the northern boundary in Ust’-Lenskiy nature reserve (Yakutia). Communication I. Kayander larch Larix cajanderi Mayr

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    The distribution of the Cayander larch Larix cajanderi Mayr within the northern boundary, on the right bank of the Lena river in Ust’-Lenskiy nature reserve in Yakutia is discussed in the article. In the studied area, normal, curved, curtain, semi-shelter and elfin forms of growth of the Cajander larch were recorded, and the geographical coordinates of their locations are given. Larch communities are distributed over 6 ecological-topological areas of the terrain: along the banks of the Lena river, between the Tit-Ary island and the mouth of the Chinke river; in the interfluve of the Chinke and Sobol’-Yuryage rivers; below the mouth of the Sobol’-Yuryage river; on the left bank of the Chinke river valley; on the right bank of the valleys of the Chinke and Chinke Salata rivers. On the right bank of the Lena river between the Tit-Ary island and upstream from the mouth of the Chinke river, larch forests are common with small gaps. Their last locations are found in the mouth part of the Chinke river. In the interfluve between the Chinke and Sobol’-Yuryage rivers there is a small number of semi-elfin forest growth forms of larch trees. The last reliably registered larch communities were found at a distance of 2.1 km below the mouth of the Sobol’-Yuryage river. On the left bank of the Chinke river valley, on the slopes of the northern exposure, 5 locations of larch were found. All of them are located below the confluence of the Chinke-Yuryage and the Chinke-Salata rivers, at a distance from the Lena river up to 1.4 km. On the right side of the valley of the Chinke and the Chinke-Yuryage rivers, on the slopes of the southern exposition, larch communities are more common and were observed at a distance of 3 km from the Lena river to (thirteen locations). In the valley of the Chinke-Salata river larch is found only in one place, on the slope of the southern exposure, at a distance of 0.5 km from the confluence with the Chinke-Yuryage river. The conservation regime of the territory eliminates the anthropogenic impact on the natural process of larch moving to the north, which makes it possible to organize and conduct long-term monitoring observations of the dynamics of forest vegetation in the far north

    Effect of stress reversal frequency on the corrosion-fatigue strength of notched carbon steel specimens

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    Poa L.

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    Genus Poa L. This genus contains about 500species,distributed mostly in extratropical regions of both hemispheres (Clayton& Renvoize1986). TYPUS. — Poa pratensis L.Published as part of Olovona, Marina V. & Nikolin, E. G., 2018, Bluegrasses (Poa L., Poaceae) of Sakha (Yakutia) Republic, an annotated checklist, pp. 89-102 in Adansonia (3) (3) 40 (7) on page 91, DOI: 10.5252/adansonia2018v40a7, http://zenodo.org/record/460208
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