75 research outputs found

    The effect of supplementing of sodium butyrate containing feed with glutamine and/or glucose on the structure of the piglet digestive tract and selected blood indices

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    The effect of supplementing the standard piglet diet containing sodium butyrate with glutamine and/or glucose on the structure of the piglet digestive tract and the small intestine epithelium, acidity and volatile fatty acid content of its digesta was investigated. The free amino acids level, insulin and insulin-like growth factor-1 (IGF-1) concentration in the blood were also analysed. The experiment was performed on 156 piglets (15 litters) allocated to 5 experimental groups, 3 litters in each. Group I (C, negative control) received a basal mixture with no supplement. Group II (SB, positive control) was fed the same basal diet containing additionally 3 g of sodium butyrate per kg. Group III and IV, besides sodium butyrate, received additionally 10 g of glutamine (GT) or glucose (GC), respectively. The last group V received all these supplements, i.e. SB+GT+GC (3, 10, 10 g per kg, respectively). At 60 days of age, the piglets (6 animals from each group) were slaughtered and their intestines were measured and weighed. The piglets in group SB+GT+GC receiving all the supplements grew slightly faster than the others, and at the end of the experiment the differences in body weight were significant. The total intestinal mass of the piglets fed with glucose or all the supplements was significantly higher than that of the piglets receiving glutamine but there was no significant difference in the total length of intestines. There was also no significant difference in acidity of chyme along the entire length of the gastrointestinal tract. Digesta in the jejunum of both control groups (C, SB) contained significantly more SCFA than the remaining groups. In the caecum their content in the negative control and the group fed with all supplements was significantly higher when compared to the butyrate and glucose group. In the duodenum villus height was similar in all the groups but in the jejunum it was significantly higher in the group receiving all supplements than in other groups. Free amino acids level was lowest in the piglets receiving glucose but there was no difference between the remaining groups. The lowest level of IGF-1 was found in the same group and this difference was significant when compared with remaining groups, except C. It is concluded that glutamine and glucose, when given together with sodium butyrate, improve the structure of piglet jejunum epithelium and average body weight gains. A supplement of glucose significantly lowers free amino acid content and IGF-1 level in piglet blood

    The Doping Effect of Fluorinated Aromatic Solvent on the Rate of Ruthenium Catalysed Olefin Metathesis

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    A study concerning the effect of using a fluorinated aromatic solvent as the medium for olefin metathesis reactions catalysed by ruthenium complexes bearing N-heterocyclic carbene ligands is presented. The use of fluorinated aromatic hydrocarbons (FAH) as solvents for olefin metathesis reactions catalysed by standard commercially available ruthenium pre-catalysts allows substantially higher yields of the desired products to be obtained,especially in the case of demanding polyfunctional molecules, including natural and biologically active compounds. Interactions between the FAH and the second-generation ruthenium catalysts, which apparently improve the efficiency of the olefin metathesis transformation, have been studied by X-ray structure analysis and computations, as well as by carrying out a number of metathesis experiments. The optimisation of reaction conditions by using an FAH can be regarded as a complementary approach for the design of new improved ruthenium catalysts. Fluorinated aromatic solvents are an attractive alternative medium for promoting challenging olefin metathesis reactions

    Ruthenium Complex Bearing a Hydroxy Group Functionalised N-Heterocyclic Carbene Ligand – A Universal Platform for Synthesis of Tagged and Immobilised Catalysts for Olefin Metathesis

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    Six olefin metathesis catalysts, based on a common ruthenium precursor featuring a hydroxy-substituted N-heterocyclic carbene ligand, were successfully prepared and fully characterised. As proof-of-concept, two of them ([Ru]isonico and [Ru]dmab) were directly immobilised on a solid support. These non-covalently heterogenised catalysts are efficient in different metathesis reactions and sufficiently stable to be used for repeated runs under batch and continuous flow conditions. In nonpolar media such as n-hexane, the catalytic character of the metathesis reactions is truly heterogeneous, and the contamination of the products with ruthenium is very low. © 2021 The Authors. European Journal of Organic Chemistry published by Wiley-VCH Gmb

    Progress in metathesis chemistry

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