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排序方式: 共有69条查询结果,搜索用时 31 毫秒
41.
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
42.
V. N. Krasilnikov G. A. Batalova V. S. Popov S. S. Sergeyeva 《Russian Agricultural Sciences》2018,44(5):406-408
Naked oat lines 1h07, 766h05, 857h05, 41h04, 37h12о, 74h12, and 8h12 have been studied to characterize the fatty acid composition of acyl lipids, which represent one of the basic groups of macronutrients providing energy and plastic material for metabolic processes. Crude lipid content in the grain of these lines is 6.9 ± 098% on average and varies from 5.91 to 7.87%. Fatty acids dominating in the lipid composition of the grain include palmitic (15.3–17.8%), oleic (33.5–36.7%), and linoleic (36.2–38.7%) acids. According to the content of oleic and linoleic acide and their ratio (1: 1), lipids of naked oat belong to the oleic-linoleic group of vegetable oils. 相似文献
43.
Kellie M. Whipple James F. Wellehan Albert B. Jeon Bethany R. Sabatino Salvatore Frasca Jr Vsevolod L. Popov Robert Ossiboff Mary K. Leissinger 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2020,49(2):326-332
An adult dog was presented for chronic cough and a recent development of ulcerated, erythematous nares with nasal discharge. Cytology of enlarged peripheral lymph nodes revealed many intracellular and extracellular organisms. These round or rarely oval organisms measured approximately 5-9 µm in diameter and frequently contained several globular structures, ranging from deeply basophilic to magenta. A thin, clear halo was present. Smaller 1-2 µm, magenta forms were also observed. Fungal culture yielded small, wet, raised, irregularly shaped, white to pale tan colonies. Microbiologic staining of cultured material revealed features suggestive of algae. Histopathology of the lymph nodes revealed marked granulomatous inflammation with intralesional algal organisms suggestive of Prototheca. Electron microscopic findings were also consistent with protothecosis. Polymerase chain reaction, followed by direct DNA sequencing, identified the organism as Prototheca wickerhamii. A brief literature review discussing protothecosis in veterinary medicine is included. 相似文献
44.
We show the anisotropic selective growth of gold tips onto semiconductor (cadmium selenide) nanorods and tetrapods by a simple reaction. The size of the gold tips can be controlled by the concentration of the starting materials. The new nanostructures display modified optical properties caused by the strong coupling between the gold and semiconductor parts. The gold tips show increased conductivity as well as selective chemical affinity for forming self-assembled chains of rods. Such gold-tipped nanostructures provide natural contact points for self-assembly and for electrical devices and can solve the difficult problem of contacting colloidal nanorods and tetrapods to the external world. 相似文献
45.
Anikovich MV Sinitsyn AA Hoffecker JF Holliday VT Popov VV Lisitsyn SN Forman SL Levkovskaya GM Pospelova GA Kuz'mina IE Burova ND Goldberg P Macphail RI Giaccio B Praslov ND 《Science (New York, N.Y.)》2007,315(5809):223-226
Radiocarbon and optically stimulated luminescence dating and magnetic stratigraphy indicate Upper Paleolithic occupation-probably representing modern humans-at archaeological sites on the Don River in Russia 45,000 to 42,000 years ago. The oldest levels at Kostenki underlie a volcanic ash horizon identified as the Campanian Ignimbrite Y5 tephra that is dated elsewhere to about 40,000 years ago. The occupation layers contain bone and ivory artifacts, including possible figurative art, and fossil shells imported more than 500 kilometers. Thus, modern humans appeared on the central plain of Eastern Europe as early as anywhere else in northern Eurasia. 相似文献
46.
S. N. Drozdov E. G. Popov E. S. Kholoptseva A. F. Titov 《Russian Agricultural Sciences》2008,34(2):91-92
The effect of soil temperature on CO2 exchange of intact narrowleaf lupine variety Siderat 38 plants depending on illumination level and air temperature is studied in a multifactorial experiment under controlled environmental conditions. It is shown that the strength of influence of soil temperature on net photosynthesis of plants depends to a considerable extent on air temperature and to a lesser degree on illumination. 相似文献
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49.
LTK Do Z Namula VV Luu Y Sato M Taniguchi T Isobe K Kikuchi T Otoi 《Reproduction in domestic animals》2014,49(2):e17-e20
This study aimed to examine the effects of sericin supplementation during in vitro oocyte maturation on the nuclear maturation, fertilization and development of porcine oocytes. Cumulus‐oocyte complexes (COCs) were cultured in maturation medium supplemented with 0 (control), 0.1, 0.5, 1.0, 2.5 or 5.0% sericin and were then subjected to in vitro fertilization and embryo culture. More COCs matured with 1.0% sericin underwent germinal vesicle breakdown and reached metaphase II compared with the control COCs matured without sericin (p < 0.01). The proportions of oocytes with DNA‐fragmented nuclei did not differ between the groups, regardless of the sericin level. The total fertilization rate of oocytes matured with 1.0% sericin was higher (p < 0.05) than that of oocytes matured with 0.1%, 2.5% and 5.0% sericin. Supplementation with more than 1.0% sericin decreased the DNA fragmentation index of the blastocysts compared with the control group (p < 0.05). However, the supplementation of the maturation medium with sericin had no beneficial effects on the cleavage, development to the blastocyst stage and the total cell number of the embryos. Our findings indicate that supplementation with 1.0% sericin during maturation culture may improve the nuclear maturation and the quality of the embryos but does not affect blastocyst formation. 相似文献
50.