Search results for "LIPIDS"
showing 10 items of 2228 documents
The influence of Span®20 on stratum corneum lipids in Langmuir monolayers: comparison with Azone®
2000
Recently we have proved that Span 20 has the same enhancer effect as Azone on in vitro percutaneous penetration of lipophilic compounds (logP(oct) from 1.34 to 2.33). The purpose of this work is to study the interactions of Span 20 with stratum corneum lipids monolayers and to compare them with Azone. The surface pressure-area characteristics of Span 20 in mixed monolayers with different model lipids (ceramides, cholesterol, free fatty acids and two mixtures of ceramides+cholesterol, and ceramides+cholesterol+free fatty acids) in similar proportions to that which exists in human stratum corneum lipids were recorded as compression isotherms at 25 degrees C. Azone was also investigated on mon…
Low-density-lipoproteins size and cardiovascular prevention
2005
Low-density lipoprotein (LDL) size appears to be an important predictor of cardiovascular events and progression of coronary artery disease, and the predominance of small, dense LDL has been accepted as an emerging cardiovascular risk factor by the National Cholesterol Education Program Adult Treatment Panel III. Yet, other authors have suggested that LDL subclass measurement does not add independent information to that conferred generically by LDL concentration and other standard risk factors. Therefore, the debate continues as to whether to measure LDL particle size for cardiovascular prevention and, if so, in which categories of patients. Since the therapeutic modulation of distinct LDL …
Self-Efficacy, Planning, or a Combination of Both? A Longitudinal Experimental Study Comparing Effects of Three Interventions on Adolescents’ Body Fat
2016
Author(s): Luszczynska, Aleksandra; Hagger, Martin S; Banik, Anna; Horodyska, Karolina; Knoll, Nina; Scholz, Urte | Abstract: BackgroundThe superiority of an intervention combining two sets of theory-based behavior change techniques targeting planning and self-efficacy over an intervention targeting planning only or self-efficacy only has rarely been investigated.PurposeWe compared the influence of self-efficacy, planning, and self-efficacy+planning interventions with an education-based control condition on adolescents' body fat, assuming mediating effects of respective social cognitive variables and moderate-to-vigorous physical activity (MVPA). The moderating role of the built environment…
Production of vegetable oil-based biofuels—Thermochemical behavior of fatty acid sodium salts during pyrolysis
2009
Abstract To develop an advanced pyrolysis process for various biomass-derived feedstocks and improve product quality and yield, in-depth investigations into the reaction mechanisms are needed. This paper reports on pyrolysis experiments (Py-GC/MSD and FID) with model compounds including the sodium salts of stearic (C18), oleic (C18:1), and linoleic (C18:2) acids principally obtained from alkaline hydrolysis of vegetable oils. Of the parameters studied – temperature (450–750 °C), time (20 s and 80 s), and the degree of unsaturation (i.e., saturated and mono- and dienoic C18-hydrocarbon chains) – the latter had the most significant effect on the formation of volatile compounds detected in pyr…
Changes in soil microbial community structure influenced by agricultural management practices in a mediterranean agro-ecosystem.
2013
Agricultural practices have proven to be unsuitable in many cases, causing considerable reductions in soil quality. Land management practices can provide solutions to this problem and contribute to get a sustainable agriculture model. The main objective of this work was to assess the effect of different agricultural management practices on soil microbial community structure (evaluated as abundance of phospholipid fatty acids, PLFA). Five different treatments were selected, based on the most common practices used by farmers in the study area (eastern Spain): residual herbicides, tillage, tillage with oats and oats straw mulching; these agricultural practices were evaluated against an abandon…
Phosphatidylcholine-Gramicidin a Interaction Study in Non-Aqueous Solvent with a new HPLC-SEC Column
1985
Abstract A new HPLC-SEC column, Ultrastyragel 500 A, has been assayed in order to check the separation between gramicidin A and phosphatidylcholine in tetrahydrofuran. The good resolution of both compounds has allowed the quantitation of lipid-polypeptide interaction in terms of the binding ratio parameter, BR. A BR value of 3.6 moles of phosphatidylcholine per mole of gramicidin A has been obtained for a 0.1 % (w/v) phosphatidylcholine solution as eluent. The suitability of this support for studies on lipid-polypeptide interactions in non-aqueous solvents is demonstrated.
Polymer-based materials modified with magnetite nanoparticles for enrichment of phospholipids
2018
[EN] A polymeric material modified with magnetic nanoparticles (MNPs) has been synthesized and evaluated as sorbent both for solid-phase extraction (SPE) and dispersive magnetic solid-phase extraction (MSPE) of phospholipids (PLs) in human milk samples. The synthesized sorbent was characterized by scanning electron microscopy and its iron content was also determined. Several experimental variables that affect the extraction performance (e.g. loading solvent, breakthrough volume and loading capacity) were investigated and a comparison between conventional SPE and MSPE modalities was done. The proposed method was satisfactorily applied to the analysis of PLs in human milk fat extracts in diff…
Impact of obesity on the oro-sensory detection of dietary lipids in mice and humans
2013
Gustation is an essential parameter in the oro-sensory detection of dietary lipids. In mice and most likely in humans, the binding of long-chain fatty acids to the CD36 receptor plays a major role in this oral fat detection. Gustation is involved in the food choice (fat sensitivity) as well as in the preparation of the body to the fat inflow. This oral lipid sensing is highly regulated. As obesity seems to be responsible for an alteration of the basic tastes detection, the aim of this thesis was to investigate whether obesity can impair the oral lipid detection in both mice and humans. In humans, our data show that there is an alteration of the oral fat detection in some obese subjects who …
Identification and quantification of phosphatidylcholines containing very-long-chain polyunsaturated fatty acid in bovine and human retina using liqu…
2010
The retina is one of the vertebrate tissues with the highest content in polyunsaturated fatty acids (PUFA). A large proportion of retinal phospholipids, especially those found in photoreceptor membranes, are dipolyunsaturated molecular species. Among them, dipolyunsaturated phosphatidylcholine (PC) molecular species are known to contain very-long-chain polyunsaturated fatty acids (VLC-PUFA) from the n-3 and n-6 series having 24-36 carbon atoms (C24-C36) and four to six double bonds. Recent interest in the role played by VLC-PUFA arose from the findings that a protein called elongation of very-long-chain fatty acids 4 (ELOVL4) is involved in their biosynthesis and that mutations in the ELOVL…
Chemoenzymatic Synthesis of Functional Sialyl LewisX Mimetics with a Heteroaromatic Core
2014
Functional mimetics of the sialyl Lewis(X) tetrasaccharide were prepared by the enzymatic sialylation of a 1,3-diglycosylated indole and a glycosyl azide, which was subsequently transformed into a 1,4-diglycosylated 1,2,3-triazole, by using the trans-sialidase of Trypanosoma cruzi. These compounds inhibited the binding of E-, L-, and P-selectin-coated nanoparticles to polyacrylamide-bound sialyl-Lewis(X) -containing neighboring sulfated tyrosine residues (sTyr/sLe(X) -PAA) at low or sub-millimolar concentrations. Except for E-selectin, the mimetics showed higher activities than the natural tetrasaccharide.