排序方式: 共有37条查询结果,搜索用时 62 毫秒
21.
Konuspayeva Gaukhar Faye Bernard Loiseau Gérard Narmuratova Meiramkul Ivashchenko Anatoly Meldebekova Aliya Davletov Sydyk 《Tropical animal health and production》2010,42(3):495-499
The change in the composition of camel milk in four dromedaries was studied by including the common measured parameters: protein,
total fat, lactose, main minerals (calcium, phosphorus, and iron), and vitamin C. The fat matter varied from 4.34% to 7.81%
with a slight decrease all along the lactation and a minimal value at the 14th week corresponding to the lactation peak. Those
variations were less important for protein content (from 2.58% to 3.64%), but the minimal value was observed at the 14th week
also. The lactose varied slightly around its mean of 3.46%. The vitamin C concentration varied from 48 to 256 mg/l with a
tendency of increasing all along the lactation. Calcium and phosphorus concentrations were quite parallel and their ratio
Ca/P was constant. The minimal values (1.43 g/l for calcium and 1.16 g/l for phosphorus) were observed at the beginning of
the lactation. The iron concentrations varied around the mean of 1.73 mg/l. 相似文献
22.
23.
24.
Alexandra S. Silchenko Anatoly I. Kalinovsky Sergey A. Avilov Pelageya V. Andrijaschenko Roman S. Popov Ekaterina A. Chingizova Vladimir I. Kalinin Pavel S. Dmitrenok 《Marine drugs》2021,19(12)
Four new triterpene disulfated glycosides, chitonoidosides E1 (1), F (2), G (3), and H (4), were isolated from the Far-Eastern sea cucumber Psolus chitonoides and collected near Bering Island (Commander Islands) at depths of 100–150 m. Among them there are two hexaosides (1 and 3), differing from each other by the terminal (sixth) sugar residue, one pentaoside (4) and one tetraoside (2), characterized by a glycoside architecture of oligosaccharide chains with shortened bottom semi-chains, which is uncommon for sea cucumbers. Some additional distinctive structural features inherent in 1–4 were also found: the aglycone of a recently discovered new type, with 18(20)-ether bond and lacking a lactone in chitonoidoside G (3), glycoside 3-O-methylxylose residue in chitonoidoside E1 (1), which is rarely detected in sea cucumbers, and sulfated by uncommon position 4 terminal 3-O-methylglucose in chitonoidosides F (2) and H (4). The hemolytic activities of compounds 1–4 and chitonoidoside E against human erythrocytes and their cytotoxic action against the human cancer cell lines, adenocarcinoma HeLa, colorectal adenocarcinoma DLD-1, and monocytes THP-1, were studied. The glycoside with hexasaccharide chains (1, 3 and chitonoidoside E) were the most active against erythrocytes. A similar tendency was observed for the cytotoxicity against adenocarcinoma HeLa cells, but the demonstrated effects were moderate. The monocyte THP-1 cell line and erythrocytes were comparably sensitive to the action of the glycosides, but the activity of chitonoidosides E and E1 (1) significantly differed from that of 3 in relation to THP-1 cells. A tetraoside with a shortened bottom semi-chain, chitonoidoside F (2), displayed the weakest membranolytic effect in the series. 相似文献
25.
Global climate changes can lead to the destruction of the permafrost zone and contribute to the active transfer of pollutants to natural waters. This can be especially pronounced in the areas of oil and gas production in the Arctic. This study aimed to define the landscape components (i.e., groundwater, soil water, soil, and indicator plant species) of chemical pollution with metals, oil hydrocarbons, and polycyclic aromatic hydrocarbons, from the discharge of drill cuttings. Studies at two sites in the forest-tundra zone of Western Siberia (Russia) were carried out within two years of pollution. Pollutant migration was found in peaty-gley heavy loamy soils and iron-illuvial clayey podburs, but lateral migration of different pollutants did not exceed 200 m. Additionally, radial migration was practically absent owing to the high buffering capacity of the soil organic horizon and the upward flow of matter in the seasonal melt layer. The main indicators of drilling waste pollution were high concentrations of Sr, Ba, petroleum hydrocarbons, and Cl- ions. At the waste disposal sites, the concentration of Ba and Sr in the soil water were 1 150 and 1 410 μg L-1, respectively; in groundwater, they reached 721 and 2 360 μg L-1, respectively. In the soil, Ba and Sr accumulated in the peaty horizon (798 and 706 mg kg-1, respectively). The concentration of Cl- ions in the soil water at the site of waste discharge was 1 912 mg L-1, and at a distance of 200 m, it decreased to 77.4 mg L-1. The Cl- concentration in the groundwater was lower, and at a distance of 200 m, it was 38.9 mg L-1. The highest concentration of petroleum hydrocarbons in the surface layer was found in the peaty-gley soils (up to 2 400 mg kg-1). In glandular-illuvial podburs, it was 420 mg kg-1. In horizons BH and BC, it was close to the background values (27 and 33 mg kg-1, respectively). Alkalinization of soils and water under the influence of drill cuttings led to the death of oligotrophic and acidophilic vegetation at a distance of up to 50 m, and to the restructuring of the species and spatial structure of plant communities up to 100 m. 相似文献
26.
Belonoshko AB Skorodumova NV Rosengren A Johansson B 《Science (New York, N.Y.)》2008,319(5864):797-800
Earth's solid-iron inner core is elastically anisotropic. Sound waves propagate faster along Earth's spin axis than in the equatorial plane. This anisotropy has previously been explained by a preferred orientation of the iron alloy hexagonal crystals. However, hexagonal iron becomes increasingly isotropic on increasing temperature at pressures of the inner core and is therefore unlikely to cause the anisotropy. An alternative explanation, supported by diamond anvil cell experiments, is that iron adopts a body-centered cubic form in the inner core. We show, by molecular dynamics simulations, that the body-centered cubic iron phase is extremely anisotropic to sound waves despite its high symmetry. Direct simulations of seismic wave propagation reveal an anisotropy of 12%, a value adequate to explain the anisotropy of the inner core. 相似文献
27.
Joni Kujansuu Koh Yasue Takayoshi Koike Anatoly P. Abaimov Takuya Kajimoto Takashi Takeda Morihiko Tokumoto Yojiro Matsuura 《Journal of Wood Science》2007,53(2):87-93
An analysis was performed on the climatic responses of the radial growth of Larix gmelinii (Rupr.) Rupr. on contrasting north-facing and south-facing slopes in Tura, central Siberia. We developed chronologies of
tree-ring width for four plots, designated as north-upper, northlower, south-upper, and south-lower. Both residual and standard
chronologies of tree-ring widths exhibited a significant positive correlation with temperature from the end of May until early
June in all four plots. The chronologies of ring width did not reveal any major difference in the response to temperature
among the four plots. The standard chronologies of ring widths on the north-facing slope were negatively correlated with precipitation
during the winter (October–April) and in early and mid-May, whereas the residual chronologies did not reveal clear relationships
with precipitation during the winter and May. The significant correlation between ring width and temperature from the end
of May until early June indicates that temperatures in springtime play a significant role in the radial growth of L. gmelinii. The negative correlations between standard chronologies of tree-ring width and precipitation in the winter and in May on
the north-facing slope indicate that lowfrequency fluctuations in snowfall have negative effects on the radial growth. However,
these effects vary and depend on the microscale topography.
Part of this report was presented at the 55th Annual Meeting of the Japan Wood Society, March 2005, Kyoto 相似文献
28.
Effect of fire on solute release from organic horizons under larch forest in Central Siberian permafrost terrain 总被引:1,自引:0,他引:1
To evaluate the effects of forest fire and post-fire stand recovery on the organic layer chemistry and solute release within mound and trough microrelief elements (termed earth hummock microtopography) that mainly distribute permafrost affected area, we chose five fire plots (larch forests burned in 1951, 1981, 1990, 1994 and 2005) paired with adjacent control plots in mature larch forests in Central Siberian permafrost terrain. We determined total carbon, nitrogen and ash content in solid organic soils, and analyzed total carbon, nitrogen, bases and major anions in water extracts. There was a significant correlation between water-extracted organic carbon (WEOC) and total carbon (kg m−2) in area basis, implying that the quantity of total carbon was a major factor in WEOC production. WEOC correlated negatively with pH, indicating strong control by organic horizons (organic solute leaching) on soil acidity and base cation dynamics. The sum of water extractable base cations was also correlated significantly to total carbon, indicating that cations can be released through organic matter decomposition. Organic horizons in troughs in burned plots released greater amounts of Ca, Mg and K than those in mounds, probably due to greater content of organic matter as a cation source. Anions including nitrate and phosphate and WEOC also accumulated in trough depressions, due probably to organic matter degradation. The contrasting distribution of solutes between mounds and troughs in burned plots seems to be controlled by organic horizon development via changes in microtopography after forest fires. 相似文献
29.
Krassimir D. Naydenov Michel K. Naydenov Alexander Alexandrov Kole Vasilevski Georgi Hinkov Vlado Matevski Biljana Nikolic Venceslas Goudiaby Dave Riegert Despina Paitaridou Andreas Christou Irina Goia Christopher Carcaillet Adrian Escudero Alcantara Cengiz Ture Suleyman Gulcu Veselka Gyuleva Srdjan Bojovic Lorenzo Peruzzi Salim Kamary Anatoly Tsarev Faruk Bogunic 《European Journal of Forest Research》2017,136(5-6):767-786
The historical changes in European Black Pine population size across the whole natural distribution in Europe and Asia Minor were analyzed facing the Plio-Pleistocene climatic fluctuations. Thirteen chloroplast SSRs and SNPs markers have been studied under the assumptions of “neutral evolution.” Populations and meta-populations had different histories of migration routes, and they were strongly affected by complex patterns of isolation, fragmentation, speciation, expansion (1.88–4.28 Ma), purification selection (2.09–21.41 Ma) and bottleneck (1.85–21.76 Ma). A significant number of populations (min. 29–41%) were in equilibrium for very long periods. Generally, the bottleneck revealed by chloroplast DNA is weaker than the bottleneck revealed by nuclear DNA. The N e immediately after the bottleneck reaches between 1820 and 3640 individuals. Generally, the historical effective population sizes shrink significantly for the Tertiary period from 10–15 up to 2.5 Ma in Western Europe (by 82%), followed by Asia Minor (69%) and the Balkan Peninsula (28%), likely resulting from important climatic changes. The rates and frequencies of stepwise westwards migration waves have been not sufficient to prevent isolation between the meta-populations and to suppress “sympatric speciation.” The migration was weak for the Pliocene, but was maximal for the Pleistocene, and finally silent for the present interglacial period, namely the Holocene. 相似文献
30.
Alexandra V. Amosova Lyudmila V. Zemtsova Olga Yu. Yurkevich Elena N. Zhidkova Tomasz Książczyk Natalia G. Shostak Anatoly A. Muravlev Anna M. Artemyeva Tatiana E. Samatadze Svyatoslav A. Zoshchuk Olga V. Muravenko 《Euphytica》2017,213(9):217
Resynthesized Brassica napus L. is an important source for broadening genetic diversity and producing lines with desired characteristics. It is also a fine model to study the processes of genomic reorganizations in recently formed polyploids. We firstly performed molecular cytogenetic characterization of newly resynthesized rapeseed (B. rapa ssp. narinosa × B. oleracea ssp. capitata) and its parental species, and also examined genomic changes in hybrids of the succeeding generations grown under pressure of selection of yellow-seeded progeny. For karyotype studies, FISH/GISH with 45S, 5S rDNA, C genome specific BoB014O06 BAC clone and genomic DNA of parental B. rapa was performed. Synthetic S0–S2 hybrids had common rapeseed karyotypes (2n = 38) including 14 loci of 45S rDNA sites and 10 loci of 5S rDNA. Progeny selection led to gradual deletion of C genome chromosomes in hybrid karyotypes. So, in karyotypes of S6 and S7 hybrids, the chromosome number was reduced to 2n = 20–22, and only chromosomes of A genome bearing 10–13 loci of 45S rDNA and 8–10 loci of 5S rDNA, variations in chromosome number, chromosome rearrangements as well as examples of trisomy and monosomy were revealed. Our findings indicate an enhanced genome instability in resynthesized rapeseed lines developed under the pressure of selection which might lead to chromosome rearrangements or/and deletions and even elimination of the whole parental genome in hybrids in succeeding generations. The approach can be useful for the development of rapeseed lines with trisomy, chromosome addition/substitution lines important for genetics and plant breeding. 相似文献