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The chemical speciation of sulfur in geological fluids is a controlling factor in a number of processes on Earth. The two major chemical forms of sulfur in crustal fluids over a wide range of temperature and pressure are believed to be sulfate and sulfide; however, we use in situ Raman spectroscopy to show that the dominant stable form of sulfur in aqueous solution above 250°C and 0.5 gigapascal is the trisulfur ion S(3)(-). The large stability range of S(3)(-) enables efficient transport and concentration of sulfur and gold by geological fluids in deep metamorphic and subduction-zone settings. Furthermore, the formation of S(3)(-) requires a revision of sulfur isotope-fractionation models between sulfides and sulfates in natural fluids. 相似文献
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This paper comparatively analyzes the density of nucleotide sequences potentially predisposed to the formation of noncanonical DNA structures (G4 quadruplexes) on the hemagglutinin (HA) and neuraminidase (NA) genes of the avian influenza A virus (H5N1) and the env and pol genes of the bovine leucosis virus. The higher genetic heterogeneity of the HA gene in comparison with the NA gene coincided with the high frequency of the nucleotide sequences predisposed to the formation of G4 quadruplexes. The same tendency was observed when comparing the distribution of potential G4 quadruplexes in the env and pol genes of the bovine leucosis virus. We discuss a possible relation between the increased density of the noncanonical DNA structures in the genes whose products interact with the receptor system of target cells of a retrovirus infection and their genetic heterogeneity maintained in the host-pathogen system. 相似文献
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Impact of mash and crumble diets on intestinal amino acids transporters,intestinal morphology and pancreatic enzyme activity of broilers 下载免费PDF全文
Reza Mahdavi Artyom Karlovich Osmanyan Vladimir Ivanovich Fisinin Shahab Ghazi Harsini Anna Leonidovna Arkhipova Alexander Nikolayevich Shevyakov Svetlana Nikolaevna Kovalchuk Gleb Yurievich Kosovsky 《Journal of animal physiology and animal nutrition》2018,102(5):1266-1273
The objective of this study was to evaluate effects of mash and crumble pre‐starter diets on pancreatic enzyme activity, intestinal morphology, gene expression of intestinal peptide and amino acid (AA) transporters of broilers. Broilers in battery cages were assigned to different feed forms of pre‐starter diet from 1 to 10 days of age. Significantly increased body weight gain (BWG), feed intake (FI) and lowered FCR were observed in birds fed crumble pre‐starter diet (CPD, p < 0.05). Feed forms had no effect on whole and small intestine length, but relative intestinal length and relative small intestinal length significantly increased in the broilers fed a mash pre‐starter diet (MPD, p < 0.05). Feeding CPD increased the weight of pancreas (p < 0.05), but relative weight of the pancreas was not influenced by treatments. Pancreatic protease and amylase activities significantly increased in the broilers fed CPD (p < 0.05) but the activity of lipase was not influenced. Crypt depth (CD) and villus height (VH) were higher in broilers fed CPD (p < 0.05) but villus width (VW), villus surface area (VSA) and villus height‐to‐crypt depth ratio (VCR) were not influenced by treatments. mRNA levels for peptide transporter 1 (PepT1), Na+‐independent cationic AA transporter1 (CAT1), Na+‐independent cationic and Na+‐dependent neutral AA transporter 1 (y+LAT1) and Na+‐dependent neutral AA transporter (B0AT) were lower in birds fed CPD (p < 0.05). There were no differences in mRNA abundance of Na+‐independent cationic and zwitterionic AA transporter (b0,+AT) among treatments. Overall, the present data showed that feeding crumble diet during first 10 days of age, through higher FI, enhanced intestinal histomorphology, increased digestive enzyme activity is beneficial to growth performance of broilers. Indeed, dietary form can be an important factor in the expression of jejunal transporters. 相似文献
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Slimak L Svendsen JI Mangerud J Plisson H Heggen HP Brugère A Pavlov PY 《Science (New York, N.Y.)》2011,332(6031):841-845
Palaeolithic sites in Russian high latitudes have been considered as Upper Palaeolithic and thus representing an Arctic expansion of modern humans. Here we show that at Byzovaya, in the western foothills of the Polar Urals, the technological structure of the lithic assemblage makes it directly comparable with Mousterian Middle Palaeolithic industries that so far have been exclusively attributed to the Neandertal populations in Europe. Radiocarbon and optical-stimulated luminescence dates on bones and sand grains indicate that the site was occupied during a short period around 28,500 carbon-14 years before the present (about 31,000 to 34,000 calendar years ago), at the time when only Upper Palaeolithic cultures occupied lower latitudes of Eurasia. Byzovaya may thus represent a late northern refuge for Neandertals, about 1000 km north of earlier known Mousterian sites. 相似文献
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D'Agostino EM Rossetti D Atkins D Ferdinando D Yakubov GE 《Journal of agricultural and food chemistry》2012,60(12):3318-3328
The luminal surface of the gastrointestinal tract is covered by a mucus gel layer that acts to protect gut epithelial cells from the harsh luminal environment. This study investigated the use of two human colonic adenocarcinoma cell lines, HT29-MTX-E12 and HT29, as a model to mimic gut epithelium with and without a mucus gel layer. The effect of adding the tea polyphenols epigallocatechin gallate (EGCG) and epicatechin (EC) to the cells with subsequent examination of cell morphology and viability was assessed. EGCG, at the concentrations tested, was very toxic to the HT29 cells, but less toxic to the HT29-MTX-E12 cells, suggesting that the mucus gel layer on the HT29-MTX-E12 cells can protect the cells against EGCG toxicity. In contrast, EC had no effect on the viability of either the HT29 or HT29-MTX-E12 cells, suggesting that proteins within the mucus gel layer on the apical surface of gut epithelial cells may bind to the galloyl ring of EGCG. The effect of adding food-related ingredients with the ability to complex with EGCG, β-casein and maltodextrin, on cell viability was also examined. The presence of β-casein was very effective in protecting the cells against the toxicity effect of EGCG, but maltodextrin, at the concentration tested, was less effective in protecting against this toxicity. In conclusion, the results demonstrate that the mucus gel layer on HT29 human colonic adenocarcinoma cells may protect these cells against EGCG toxicity. In addition, the data showing reduced toxicity of EC compared to that of EGCG suggest that the cytotoxic effects of high polyphenol levels may be associated with the ability of polyphenols to interact with cellular proteins and mucins. 相似文献
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A DNA nanostructure consisting of four four-arm junctions oriented with a square aspect ratio was designed and constructed. Programmable self-assembly of 4 x 4 tiles resulted in two distinct lattice morphologies: uniform-width nanoribbons and two-dimensional nanogrids, which both display periodic square cavities. Periodic protein arrays were achieved by templated self-assembly of streptavidin onto the DNA nanogrids containing biotinylated oligonucleotides. On the basis of a two-step metallization procedure, the 4 x 4 nanoribbons acted as an excellent scaffold for the production of highly conductive, uniform-width, silver nanowires. 相似文献
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Kovalenko I Zdyrko B Magasinski A Hertzberg B Milicev Z Burtovyy R Luzinov I Yushin G 《Science (New York, N.Y.)》2011,334(6052):75-79
The identification of similarities in the material requirements for applications of interest and those of living organisms provides opportunities to use renewable natural resources to develop better materials and design better devices. In our work, we harness this strategy to build high-capacity silicon (Si) nanopowder-based lithium (Li)-ion batteries with improved performance characteristics. Si offers more than one order of magnitude higher capacity than graphite, but it exhibits dramatic volume changes during electrochemical alloying and de-alloying with Li, which typically leads to rapid anode degradation. We show that mixing Si nanopowder with alginate, a natural polysaccharide extracted from brown algae, yields a stable battery anode possessing reversible capacity eight times higher than that of the state-of-the-art graphitic anodes. 相似文献
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V. I. Glazko I. N. Andreichenko S. N. Kovalchuk T. T. Glazko G. Yu. Kosovsky 《Russian Agricultural Sciences》2016,42(6):458-464
The analysis of the frequencies of occurrence of alleles and genoypes by the genes encoding the milk proteins (kappa-casein, casein alpha 1S, and beta-lactoglobulin) and two key enzymes of the lipid synthesis (acil-CoA diacilglicerol aciltransferaza-1 and stearoyl-CoA desaturase-1) in dairy (Black-and-White Holsteinized and Ayrshire breeds) and beef (Aberdeen-Angus and Kalmyk breeds) cattle has been performed. According to the literature and our own data sets, it was ascertained that the allelic variants of candidate genes participating in the metabolic processes and defining their functional specificity to control the important economic traits, including the milk production, are not reliable bioindicators required for the early prediction in this case. However, the allelic variants of the genes, such as kappa-casein and stearoyl-CoA desaturase-1, may be used to predict the quality but not the quantity of milk, for instance, the size of micellae in milk, the suitability of milk for firm cheese production, and the enrichment of products with unsaturated fatty acids. 相似文献
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Small intestinal adenocarcinoma in cats: 32 cases (1978-1985) 总被引:2,自引:0,他引:2
J E Kosovsky D T Matthiesen A K Patnaik 《Journal of the American Veterinary Medical Association》1988,192(2):233-235
The medical records of 32 cats with small intestinal adenocarcinoma were reviewed. Common clinical signs included vomiting, dehydration, weight loss, cachexia, anorexia, and lethargy. In 50% of the cats, an abdominal mass was palpated, and in 38%, a mass was seen on radiographs. Biopsy of the tumor without resection was performed in 9 cats; 8 cats were euthanatized at the time of surgery, 7 because of metastases, and 1 cat died 1 day after surgery. In 23 cats, resection was performed. Eleven of these died within 2 weeks after surgery (mean survival time, 2.6 days); 8 had lymph node metastasis. Twelve cats survived greater than 2 weeks after surgery. The mean survival of 11 of these cats was 15 months. Six cats were euthanatized because of recurrent signs; 5 of the 6 had a recurrent abdominal mass. One cat was alive 2 years after surgery. Results of this study indicated that cats with adenocarcinoma, even those cats with advanced disease, can have long-term survival after surgery. 相似文献
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