Search results for "Esteri"

Trans – taukskābju noteikšana pārtikas produktos izmantojot gāzu hromatogrāfiju

2016

Trans- taukskābju noteikšana pārtikas produktos izmantojot gāzu gromotogrāfiju. Vītols A. Zinātniskais vadītājs Dr. ķīm. Mekšs P., Maģistra darbs , 69 lappuses, 42 attēli, 12 tabulas, 39 literatūras avoti, 6 pielikumi. Latviešu valodā. Darba literatūras apskatā apkopota informācija par trans- taukskābju iegūšanu un izmantošanu pārtikas produktos. Apkopota informācija par trans- tauku ietekmi uz veselību. Literatūras apskatā apskatītas šobrīd visplašāk izmantotās trans- tauku analīžu metodes Darba praktiskajā daļā veikta metodes izstrāde un validācija trans- taukskābju noteikšanai, izmantojot gāzu hromotogrāfiju- masspektrometriju. Praktiski veikta 47 Latvijā nopērkamu pārtikas produktu tauk…

A Simple Fusion Method for Image Time Series Based on the Estimation of Image Temporal Validity

2015

High-spatial-resolution satellites usually have the constraint of a low temporal frequency, which leads to long periods without information in cloudy areas. Furthermore, low-spatial-resolution satellites have higher revisit cycles. Combining information from high- and low- spatial-resolution satellites is thought a key factor for studies that require dense time series of high-resolution images, e.g., crop monitoring. There are several fusion methods in the bibliography, but they are time-consuming and complicated to implement. Moreover, the local evaluation of the fused images is rarely analyzed. In this paper, we present a simple and fast fusion method based on a weighted average of two in…

Fabrication, characterization, thermal stability and nanoassemblies of novel pullulan-aspirin conjugates

2017

Abstract Present study deals with homogeneous and one-pot synthesis of novel macromolecular prodrugs (MPDs) of aspirin onto naturally occurring hydrophilic biopolymer pullulan. Pullulan-aspirin conjugates were synthesized by using green carboxylic acid activating reagent 1,1′-carbonyldiimidazole (CDI). The aspirin was first reacted with CDI to prepare aspirin-imidazolide at RT for 24 h which in situ reacted with pre-dissolved pullulan and the reaction preceded further for 24 h at 80 °C under nitrogen. Degree of substitution (DS 0.32–0.40) of aspirin onto pullulan was calculated from 1H NMR spectroscopy. Spectroscopic techniques confirmed the high covalent drug loading and purity. Thermal an…

Nanocomposites based on esterified colophony and halloysite clay nanotubes as consolidants for waterlogged archaeological woods

2017

We have designed an innovative protocol for the consolidation of waterlogged archaeological woods by using acetone mixtures of halloysite clay nanotubes and a chemically modified colophony (Rosin). Firstly, we have investigated the thermal properties of HNTs/Rosin nanocomposites, which have been prepared by means of the casting method from acetone. The HNTs content have been systematically changed in order to study the influence of the inorganic filler on the thermal stability and glass transition process of Rosin. We have observed that the thermal properties of the hybrids are affected by the specific HNTs/Rosin interactions. Then, acetone dispersions of HNTs/Rosin composites at variable f…

Enzymatically hydrolyzed low-density lipoprotein modulates inflammatory responses in endothelial cells

2009

SummaryThere is evidence that low-density lipoprotein (LDL) is modified by hydrolytic enzymes,and that the product (E-LDL) induces selective production of interleukin 8 (IL-8) in endothelial cells. Since nuclear factor-kappaB (NF-κB) is a major regulator of IL-8 transcription, we studied its activation in endothelial cells treated with E-LDL. Unexpectedly,the modified lipoprotein not only failed to activate NF-κB, but completely blocked its activation by tumour necrosis factor-alpha (TNF-α) in EA.hy926-cells, as assessed by electrophoretic mobility shift assays and immunofluorescence. Inhibition occurred upstream of NF-κB translocation, as inhibitor of NF-κB- (IκB)-phosphorylation was suppr…

Predicción de desarrollo a Blastocisto e implantación durante el proceso rutinario de incubación mediante time-lapse

2017

Objetivo: Describir los eventos morfocinéticos asociados con la formación de blastocistos e implantación, de los embriones cultivados a D5 utilizando un sistema time-lapse. Estudio observacional, retrospectivo, unicéntrico. Un total de 7,483 cigotos obtenidos de 990 pacientes en su primer ciclo de inyección intracitoplasmática de espermatozoides (ICSI), de los cuales 627 ciclos fueron de donante de ovocitos y 363 ciclos fueron de ovocitos autólogos. Se transfirieron un total de 832 blastocistos.MATERIALES Y MÉTODOS: Los embriones se cultivaron en un sistema de monitorización time-lapse, y fueron transferidos en día 5 de desarrollo. La selección de los embriones a transferir se basó en el mo…

Tuneable multicoloured patterns from photonic cross-communication between cholesteric liquid crystal droplets

2014

Monodisperse droplets of planar-aligned cholesteric (N*) liquid crystal exhibit an intriguing capacity for photonic cross-communication, giving rise to colourful patterns that depend sensitively on the N* pitch, droplet positions and illuminated area. The phenomenon results from a combination of omnidirectional selective reflection of N* droplets—which thus act as spherically symmetric self-assembled photonic crystals—and total internal reflection at the continuous phase surface. We outline how the unique optical properties can be employed in numerous applications.

THERMO-CATALYTIC PROCESSES FOR BIOFUEL PRODUCTION

2017

Capillary Electrophoresis of Free Fatty Acids by Indirect Ultraviolet Detection: Application to the Classification of Vegetable Oils According to The…

2011

A method for the determination of fatty acids in vegetable oils by capillary electrophoresis with indirect UV–vis detection has been developed. The separation of fatty acids was optimized in terms of Brij surfactant nature and concentration and organic modifier (2-propanol) percentage. The optimal background electrolyte consisted of 10 mM p-hydroxybenzoate, 5 mM Tris at pH 8.8, 80 mM Brij 98, 40% acetonitrile, and 10% 2-propanol. Under these conditions, vegetable oils from five botanical origins (avocado, corn, extra virgin olive, hazelnut, and soybean) were analyzed and the fatty acid contents established. Linear discriminant analysis (LDA) models were constructed using fatty acid peak are…

The impact of the cultivation practices on arbuscular mycorrhizal symbiosis mechanism in a walnut tree - corn agroforestry system

2021

The English walnut (Juglans regia L.) is the main species cultivated for the production of edible nuts. Owing to a sparse canopy and a deep rooting system, walnut is an ideal species for alley cropping, an agroforestry practice able to enhance productivity through interplant facilitative mechanisms. Walnut agroforestry requires the large scale production of seedling rootstocks selected to provide the best anchorage, vigour, and tolerance of pathogens. Due to the heterozygosity of walnut, the characteristics of agronomical interest of the chosen cultivar are not inherited via seed propagation. In vitro plant tissue culture thus plays a key role in mass propagation of high-quality walnut root…