Search results for "composition"

2020

Biomolecules, and particularly proteins, bind on nanoparticle (NP) surfaces to form the so-called protein corona. It is accepted that the corona drives the biological distribution and toxicity of NPs. Here, the corona composition and structure were studied using silica nanoparticles (SiNPs) of different sizes interacting with soluble yeast protein extracts. Adsorption isotherms showed that the amount of adsorbed proteins varied greatly upon NP size with large NPs having more adsorbed proteins per surface unit. The protein corona composition was studied using a large-scale label-free proteomic approach, combined with statistical and regression analyses. Most of the proteins adsorbed on the N…

Study of the factors influencing the bioaccessibility of 10 elements from chocolate drink powder

2016

Abstract A risk/benefit assessment of chocolate drink powder has been conducted by evaluating the total contents and the bioaccessibilities of Al, Ba, Cd, Cr, Cu, Fe, Mg, Mn, P and Zn. The bioaccessibility was studied considering the type of sample (traditional, light, diet and organic) and the different factors that may affect it, including physical-chemical parameters of the human digestive process (gastric pH, concentration of bile salts and presence of lipase) and the presence of dietary components (phytate, pectin, cellulose and tannin). The bioaccessibility varied greatly according to the sample type, being greater in the diet and organic samples, and on the element being considered (…

Formation and Changes of Humic Acid Properties during Peat Humification Process within Ombrotrophic Bogs

2012

Studies of the living organic matter humification process are essential for understanding the carbon biogeochemical cycle. The aim of this study is to analyze relations between the properties of peat, peat humic acids and peat humification degree. The analysis has been done on samples of humic substances extracted from peat profiles in two ombrotrophic bogs and relations between peat age, decomposition and humification degree, botanical composition and properties of peat humic acids (elemental, functional composition) were studied. The found variability of peat properties is less significant than differences in the properties of peat-forming living matter, thus revealing the dominant impact…

Genesis of Peat Humic Acid Structure and Properties Within Bog Profiles

2012

Studies of living organic matter humification process are essential for understanding of carbon biogeochemical cycle, and considering this, the aim of this study is to analyse relations between properties of the peat, peat humic acids (HAs) and humification degree on example of analysis of two bog profiles in ombrotrophic bogs to identify the links between peat age, decomposition and humification degree, botanical composition and properties of peat humic acids (elemental, functional composition). The found variability of peat properties is much less than the significant differences in properties of peat-forming living matter, thus stressing the dominant impact of humification process on pea…

Peat humic acid properties and factors influencing their variability in a temperate bog ecosystem

2013

Studies of the properties of soil organic matter are essential for understanding the humification reactions and soil diagenesis processes. The aim of this study is to analyse properties of peat and peat humic acids as well as factors influencing their variability. Humic acids isolated from an ombrotrophic bog peat profile were used as study objects. Relations among peat age, decomposition and humification degree, botanical composition, and properties of peat humic acids (elemental, functional composition, spectral characteristics) were studied. The variability of peat properties was found to be less significant than the differences in the properties of peat-forming living matter, which indi…

MCM-41 silica monoliths with independent control of meso- and macroporosity

2007

Centimetre sized macroporous silica monoliths consisting of MCM-41 have been prepared by a two-step procedure allowing an independent control of the meso- and macro-porosity. In the first step a monolith with a macroporosity tailored between 2 and 20 μm is prepared under acidic medium by a phase separation, named spinodal decomposition, leading to a bicontinuous structure of a silica/polymer phase and a water phase. The monolith is then reacted in an alkaline solution of cetyltrimethyl ammonium to transform the silica skeleton into MCM-41 under conditions which preserve the original morphology and macroporosity of the material. The combination of spinodal decomposition and pseudomorphic tra…

Characterization of Humic Acids from Raised Bog Peat

2014

Abstract Humic substances form most of the organic component of soil, peat and natural waters, but their structure and properties are very much dependent on the source. The aim of this study was to characterize humic acids from raised bog peat to evaluate the homogeneity of humic acids isolated from the bog bodies and to study peat humification impact on the properties of humic acids. Peat humic acids (HA) have an intermediate position between the living organic matter and coal organic matter, with their structure formed in a process where the relatively labile moieties (carbohydrates, amino acids, etc.) are destroyed, and thermodynamically more stable aromatic and polycyclic structures eme…

Changes in ewe milk fatty acids following turning out to pasture

2008

Abstract Ten Comisana dairy ewes were selected to observe time of changing in milk fatty acids as a result of switching from stall to pasture feeding. At first, ewes were subjected to a stall-feeding period of 30 days (pre-experimental phase). After which, ewes were abruptly turned out to a vetch and oats pasture as their sole feed (experimental phase). Individual milk samples were collected on experimental days 0 (the last day of stall feeding), 1–4, 8, 11, 17 and 23. Milk and feeds fatty acid composition was determined by gas chromatography. The sudden passage from a stall to a pasture diet significantly modified the fatty acid profile of ewe milk. Medium- and long-chain fatty acids were …

α-Hydroxy-Isocaproic Acid (HICA)—Effects on Body Composition, Muscle Soreness and Athletic Performance

2013

Alfa-hydroxy-isocaproic acid (HICA) is an end product of leucine metabolism in human tissues such as muscle and connective tissue. Clinical and experimental studies indicate that HICA may be considered as an anti-catabolic substance. Intensive exercise leads not only to anabolism but also to catabolism in the muscle. The latter is associated with breakdown of muscle proteins and delayed-onset muscle soreness (DOMS). Several studies indicate that free branched-chain amino acids (BCAAs), especially leucine, and their transaminated metabolites, such as α-ketoisocaproic acid (KIC), may alleviate symptoms associated with exercise-induced catabolism. Recent findings suggest that HICA effectively …

Acides gras des phospholipides plaquettaires et des lipides plasmatiques chez le rat obése Zucker

1988

AbstractThe purpose of this work was to see whether hyperlipaemia observed in genetically obese Zucker rats (fa/fa) was associated with differences in fatty-acid composition of plasma triacylglycerols, plasma phospholipids and of platelet phospholipids, in comparison with the control lean rats (Fa/-).Results showed that plasma triacylglycerols and phospholipids were increased in obese rats. In triacylglycerols, the amount of saturated and monounsaturated fatty acids was highly increased whereas the amount of the n-6 and n-3 polyunsaturated fatty acids was little modified. In plasma phospholipids, saturated and monounsaturated fatty acids were also increased, as were the n-3 fatty acids (exc…