Log in

Relevant bibliographies by topics / Polar lipids

Contents

Journal articles
Dissertations / Theses
Books
Book chapters
Conference papers

Academic literature on the topic 'Polar lipids'

Author: Grafiati

Published: 4 June 2021

Last updated: 25 April 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Polar lipids.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Polar lipids"

1

Anto, Liya, Sarah Wen Warykas, Moises Torres-Gonzalez, and Christopher N. Blesso. "Milk Polar Lipids: Underappreciated Lipids with Emerging Health Benefits." Nutrients 12, no. 4 (2020): 1001. http://dx.doi.org/10.3390/nu12041001.

Full text

Abstract:

Milk fat is encased in a polar lipid-containing tri-layer milk fat globule membrane (MFGM), composed of phospholipids (PLs) and sphingolipids (SLs). Milk PLs and SLs comprise about 1% of total milk lipids. The surfactant properties of PLs are important for dairy products; however, dairy products vary considerably in their polar lipid to total lipid content due to the existence of dairy foods with different fat content. Recent basic science and clinical research examining food sources and health effects of milk polar lipids suggest they may beneficially influence dysfunctional lipid metabolism, gut dysbiosis, inflammation, cardiovascular disease, gut health, and neurodevelopment. However, more research is warranted in clinical studies to confirm these effects in humans. Overall, there are a number of potential effects of consuming milk polar lipids, and they should be considered as food matrix factors that may directly confer health benefits and/or impact effects of other dietary lipids, with implications for full-fat vs. reduced-fat dairy.

APA, Harvard, Vancouver, ISO, and other styles

2

Warren, Charles R. "Altitudinal transects reveal large differences in intact lipid composition among soils." Soil Research 59, no. 6 (2021): 644. http://dx.doi.org/10.1071/sr20055.

Full text

Abstract:

Fatty acid-based lipids comprise a small but important component of soil organic matter. Lipids are indispensable components of soil microbes due to their function as components of membranes and as stores of energy and C. Hence, lipid composition is likely under strong selection pressure and there ought to be strong associations between lipid composition of microbial communities and environmental conditions. Associations between microbial lipids and environment likely involve an integrated combination of differences in lipid headgroups (classes) and fatty acyl chains. However, past studies examining associations between soil lipid composition and environmental conditions have focussed on fatty acids hydrolysed from polar lipids and less is known about headgroups (classes) of polar lipids. The aim of this study was to examine associations between environmental conditions changing with altitude and the intact polar and non-polar lipids of soil microbial communities. We used two altitudinal transects, both spanning from forest through to above the alpine treeline, but separated from one another by ~700 km. Liquid chromatography-mass spectrometry identified 174 intact lipids to the level of class and sum composition. Approximately half of the pool of fatty acid-based lipids was accounted for by two classes of non-polar lipids (diacylglycerol and triacylglycerols), while the other half was dominated by three classes of polar lipids (phosphatidylethanolamine, phosphatidylcholine and diacylglyceryl-N,N,N-trimethylhomoserine). There were large differences among sites in the relative amounts of lipid classes. For example, diacylglyceryl-N,N,N-trimethylhomoserine varied among sites from 5 to 41% of the polar lipid pool, phosphatidylcholine from 31 to 60% of the polar lipid pool, and diacylglycerols from 9 to 53% of the total non-polar pool. Relationships of lipid composition with altitude were weak or differed between transects, and pH was the variable most strongly associated with lipid composition. Variation among sites in the relative abundance of phosphatidylcholine were positively associated with pH, while relative and absolute abundance of diacylglycerol was negatively related to pH. We suggest that the accumulation of diacylglycerol at low pH represents slowed hydrolysis and/or microbial utilisation. A large fraction of variance among sites in lipid composition remained unexplained, which highlights the need for additional research on processes leading to production and consumption of fatty acid-based lipids.

APA, Harvard, Vancouver, ISO, and other styles

3

Zheng, Lu, Mathilde Fleith, Francesca Giuffrida, Barry V. O'Neill, and Nora Schneider. "Dietary Polar Lipids and Cognitive Development: A Narrative Review." Advances in Nutrition 10, no. 6 (2019): 1163–76. http://dx.doi.org/10.1093/advances/nmz051.

Full text

Abstract:

ABSTRACTPolar lipids are amphiphilic lipids with a hydrophilic head and a hydrophobic tail. Polar lipids mainly include phospholipids and sphingolipids. They are structural components of neural tissues, with the peak rate of accretion overlapping with neurodevelopmental milestones. The critical role of polar lipids in cognitive development is thought to be mediated through the regulation of signal transduction, myelination, and synaptic plasticity. Animal products (egg, meat, and dairy) are the major dietary sources of polar lipids for children and adults, whereas human milk and infant formula provide polar lipids to infants. Due to the differences observed in both concentration and proportion of polar lipids in human milk, the estimated daily intake in infants encompasses a wide range. In addition, health authorities define neither intake recommendations nor guidelines for polar lipid intake. However, adequate intake is defined for 2 nutrients that are elements of these polar lipids, namely choline and DHA. To date, limited studies exist on the brain bioavailability of dietary polar lipids via either placental transfer or the blood–brain barrier. Nevertheless, due to their role in pre- and postnatal development of the brain, there is a growing interest for the use of gangliosides, which are sphingolipids, as a dietary supplement for pregnant/lactating mothers or infants. In line with this, supplementing gangliosides and phospholipids in wild-type animals and healthy infants does suggest some positive effects on cognitive performance. Whether there is indeed added benefit of supplementing polar lipids in pregnant/lactating mothers or infants requires more clinical research. In this article, we report findings of a review of the state-of-the-art evidence on polar lipid supplementation and cognitive development. Dietary sources, recommended intake, and brain bioavailability of polar lipids are also discussed.

APA, Harvard, Vancouver, ISO, and other styles

4

Phan, T. T. Q., T. T. Le, and K. Dewettinck. "Adsorption behavior at interface of oil-in-water emulsions prepared with mixtures of milk fat globule membrane proteins and polar lipids." Food Research 4, no. 5 (2020): 1744–52. http://dx.doi.org/10.26656/fr.2017.4(5).167.

Full text

Abstract:

The milk fat globule membrane (MFGM) contains proteins and polar lipids making this complex mixture a good emulsifier. In this study, MFGM material was isolated from reconstituted buttermilk using microfiltration and further separated into MFGM protein concentrate and polar lipid concentrate using solvent fractionation. The emulsifying properties of those two emulsifier fractions, separately or in combination, at various concentrations of proteins (0.3; 1.3 and 2.3 w%) and polar lipids (0.3; 1.3 and 2.3 w%), were investigated. The results showed that at low emulsifier concentrations (< 2.3%), the combination of both proteins and polar lipids resulting in the formation of emulsions with a small droplets size and low apparent viscosity. The addition of polar lipids did not replace the adsorbed proteins. Between the two emulsifier fractions, MFGM protein concentrate had greater emulsifying properties compared to the polar lipid concentrate.

APA, Harvard, Vancouver, ISO, and other styles

5

Sprott, G. D., C. J. Dicaire, and G. B. Patel. "The ether lipids of Methanosarcina mazei and other Methanosarcina species, compared by fast atom bombardment mass spectrometry." Canadian Journal of Microbiology 40, no. 10 (1994): 837–43. http://dx.doi.org/10.1139/m94-133.

Full text

Abstract:

The total lipids of Methanosarcina mazei accounted for 4.0% of the cell dry mass, and 90% of these were polar lipids. Nearly all of the polar fraction consisted of diether (2,3-di-O-phytanyl-sn-glycerol) and 3-hydroxydiether analogs of phosphatidylglycerol, phosphatidylinositol, phosphatidylserine, and phosphatidylethanolamine. Several highly fluorescent trace components in the lipid extracts were purified and partially characterized by mass spectrometry. Fast atom bombardment mass spectrometry of total lipid extracts provided data to establish a close relationship among the polar lipids present in Methanosarcina mazei, Methanosarcina thermophila, Methanosarcina acetivorans, Methanosarcina barkeri Fusaro, and Methanosarcina barkeri MS.Key words: diether lipids, hydroxydiether lipids, fast atom bombardment mass spectrometry, Methanosarcina, archaeobacteria.

APA, Harvard, Vancouver, ISO, and other styles

6

Medina, Jessica, Vera van der Velpen, Tony Teav, Yann Guitton, Hector Gallart-Ayala, and Julijana Ivanisevic. "Single-Step Extraction Coupled with Targeted HILIC-MS/MS Approach for Comprehensive Analysis of Human Plasma Lipidome and Polar Metabolome." Metabolites 10, no. 12 (2020): 495. http://dx.doi.org/10.3390/metabo10120495.

Full text

Abstract:

Expanding metabolome coverage to include complex lipids and polar metabolites is essential in the generation of well-founded hypotheses in biological assays. Traditionally, lipid extraction is performed by liquid-liquid extraction using either methyl-tert-butyl ether (MTBE) or chloroform, and polar metabolite extraction using methanol. Here, we evaluated the performance of single-step sample preparation methods for simultaneous extraction of the complex lipidome and polar metabolome from human plasma. The method performance was evaluated using high-coverage Hydrophilic Interaction Liquid Chromatography-ESI coupled to tandem mass spectrometry (HILIC-ESI-MS/MS) methodology targeting a panel of 1159 lipids and 374 polar metabolites. The criteria used for method evaluation comprised protein precipitation efficiency, and relative MS signal abundance and repeatability of detectable lipid and polar metabolites in human plasma. Among the tested methods, the isopropanol (IPA) and 1-butanol:methanol (BUME) mixtures were selected as the best compromises for the simultaneous extraction of complex lipids and polar metabolites, allowing for the detection of 584 lipid species and 116 polar metabolites. The extraction with IPA showed the greatest reproducibility with the highest number of lipid species detected with the coefficient of variation (CV) < 30%. Besides this difference, both IPA and BUME allowed for the high-throughput extraction and reproducible measurement of a large panel of complex lipids and polar metabolites, thus warranting their application in large-scale human population studies.

APA, Harvard, Vancouver, ISO, and other styles

7

Bruna, M., and C. J. W. Breward. "The influence of non-polar lipids on tear film dynamics." Journal of Fluid Mechanics 746 (April 4, 2014): 565–605. http://dx.doi.org/10.1017/jfm.2014.106.

Full text

Abstract:

AbstractIn this paper we examine the effect that physiological non-polar lipids, residing on the surface of an aqueous tear film, have on the film evolution. In our model we track the evolution of the thickness of the non-polar lipid layer, the thickness of the aqueous layer and the concentration of polar lipids which reside at the interface between the two. We also utilise a force balance in the non-polar lipid layer in order to determine its velocity. We show how to obtain previous models in the literature from our model by making particular choices of the parameters. We see the formation of boundary layers in some of these submodels, across which the concentration of polar lipid and the non-polar lipid velocity and film thickness vary. We solve our model numerically for physically realistic parameter values, and we find that the evolution of the aqueous layer and the polar lipid layer are similar to that described by previous authors. However, there are interesting dynamics for the non-polar lipid layer. The effects of altering the key parameters are highlighted and discussed. In particular, we see that the Marangoni number plays a key role in determining how far over the eye the non-polar lipid spreads.

APA, Harvard, Vancouver, ISO, and other styles

8

Lordan, Ronan, Eoin O’Keeffe, Alexandros Tsoupras, and Ioannis Zabetakis. "Total, Neutral, and Polar Lipids of Brewing Ingredients, By-Products and Beer: Evaluation of Antithrombotic Activities." Foods 8, no. 5 (2019): 171. http://dx.doi.org/10.3390/foods8050171.

Full text

Abstract:

The in vitro antithrombotic properties of polar lipid constituents of malted grain (MG), pelleted hops (PH), brewer’s spent grain (BSG), spent hops (SH), wort, and bottled beer from the same production line were assessed in human platelets. The total lipids (TL) were extracted according to the Bligh and Dyer method and further separated into the total neutral lipids (TNL) and total polar lipids (TPL) extracts by counter-current distribution. The TL, TNL, and TPL extracts of all samples were assessed for their ability to inhibit platelet-activating factor (PAF) and thrombin-induced human platelet aggregation. The raw materials, by-products, wort, and beer lipid extracts all exhibited antithrombotic properties against PAF and thrombin. However, the beer TPL exhibited the lowest IC50 values against PAF-induced (7.8 ± 3.9 µg) and thrombin-induced (4.3 ± 3.0 µg) platelet aggregation indicating that these polar lipids were the most antithrombotic. The lipid extracts tended to be more bioactive against the thrombin pathway. The fatty acid content of all the TPL extracts were assessed using GC-MS. The fatty acid composition of the most bioactive TPL extracts, the wort and the beer, shared similar fatty acid profiles. Indeed, it was noted that fermentation seems to play a role in increasing the antithrombotic properties of polar lipids against PAF and thrombin by moderately altering the polar lipid fatty acid composition. Furthermore, the use of brewing by-products as a source of functional cardioprotective lipids warrants further investigation and valorisation.

APA, Harvard, Vancouver, ISO, and other styles

9

Somerharju, Pentti. "Is Spontaneous Translocation of Polar Lipids between Cellular Organelles Negligible?" Lipid Insights 8s1 (January 2015): LPI.S31616. http://dx.doi.org/10.4137/lpi.s31616.

Full text

Abstract:

In most reviews addressing intracellular lipid trafficking, spontaneous diffusion of lipid monomers between the cellular organelles is considered biologically irrelevant because it is thought to be far too slow to significantly contribute to organelle biogenesis. This view is based on intervesicle transfer experiments carried out in vitro with few lipids as well as on the view that lipids are highly hydrophobic and thus cannot undergo spontaneous intermembrane diffusion at a significant rate. However, besides that single-chain lipids can translocate between vesicles in seconds, it has been demonstrated that the rate of spontaneous transfer of two-chain polar lipids can vary even 1000-fold, depending on the number of carbons and double bonds in the acyl chains. In addition, the rate of spontaneous lipid transfer can strongly depend on the experimental conditions such as vesicle composition and concentration. This review examines the studies suggesting that spontaneous lipid transfer is probably more relevant to intracellular trafficking of amphipathic lipids than commonly thought.

APA, Harvard, Vancouver, ISO, and other styles

10

Lopes, Melo, Meneses, et al. "A New Look for the Red Macroalga Palmaria palmata: A Seafood with Polar Lipids Rich in EPA and with Antioxidant Properties." Marine Drugs 17, no. 9 (2019): 533. http://dx.doi.org/10.3390/md17090533.

Full text

Abstract:

Palmaria palmata is an edible red macroalga widely used for human consumption and valued for its high protein value. Despite its low total lipid content, it is rich in eicosapentaenoic acid (EPA). This seaweed has been scarcely explored with regard to its lipid composition. The polar lipids of seaweeds are nowadays recognized as important phytochemicals contributing to their add value valorization and providing support for claims of potential health benefits. The present study aimed to disclose the polar lipid profile of P. palmata, farmed in an integrated multi-trophic aquaculture (IMTA) through modern lipidomic approaches using high-resolution LC-MS and MS/MS and to screen for the antioxidant properties of this red macroalga. A total of 143 molecular species of lipids were identified, belonging to several classes of polar lipids, such as glycolipids, phospholipids, and betaine lipids. It is noteworthy that the most abundant lipid species in each class were esterified with eicosapentaenoic acid (EPA), accounting for more than 50% of the lipid content. The polar lipid extract rich in EPA showed antioxidant activity with an inhibition concentration (IC) of IC30 = 171 ± 19.8 µg/mL for α,α-diphenyl-β-picrylhydrazyl radical (DPPH●) and IC50 = 26.2 ± 0.1 µg/mL for 2,20-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid radical cation (ABTS●+). Overall, this study highlights that P. palmata farmed in an IMTA framework can be a sustainable source of beneficial lipids with antioxidant activity. Moreover, this red macroalga can be exploited for future applications as a source of lipids rich in EPA for food and feed, nutraceuticals, and cosmetics.

APA, Harvard, Vancouver, ISO, and other styles

Dissertations / Theses on the topic "Polar lipids"

1

Zhou, Ying. "Characterization of polar lipids using mass spectrometry." Thesis, Boston University, 2013. https://hdl.handle.net/2144/11095.

Full text

Abstract:

Thesis (Ph.D.)--Boston University<br>A sensitive, efficient one-step method to separate and define the individual structures of the components in complex mixtures of polar lipids, based on gradient reversed phase high performance liquid chromatography coupled to electrospray ionization (ESI) mass spectrometry (MS), was developed. This online system was applied to both standards and biological samples, including the polar lipids that are apparently tightly bound and therefore extracted with the prion protein. The system generated highly resolved spectra and enabled definitive lipid characterization by ESI-MS/MS. Coupling thin-layer chromatography (TLC) with ESI-MS allowed the acquisition of high resolution mass spectra of acidic glycosphingolipids with high sensitivity and mass accuracy, without the loss of sialic acid residues that frequently occurs during low-pressure matrix-assisted laser desorption/ionization MS. Based on observations of oxidation under ambient conditions made during development of the on-line TLC-ESI-MS method, a simple approach was established to elucidate carbon-carbon double bond positions in unsaturated lipids. Lipids were deposited onto various surfaces and the products resulting from their oxidation under standard laboratory conditions were observed by unmodified ESI-MS. It is shown that singlet oxygen acts in parallel with ozone to carry out the oxidation of unsaturated lipids. Direct sampling by TLC-ESI-MS provided a powerful approach to elucidate detailed structural information for biological samples; e.g., for a bovine brain total lipid extract, it was possible to distinguish among the isomers of phosphatidylserine and N,N-dimethyl phosphatidylethanolamine based on their double bond positions. A modified sulfatide extraction method and workflow were designed, using nanoESI in combination with tandem MS methods performed on the L TQ-Orbitrap TM MS, and were employed for identification and comprehensive structural characterization of sulfatides. In addition to 20 sulfatides, more than 100 other lipids were identified in a human milk fraction that showed activity against the human immunodeficiency virus and is thus of interest in the search for agents to protect infants and immunocompromised individuals. In summary, the research on the analysis of polar lipids presented here demonstrates several very effective new methods that facilitated chromatographic separation, improved the effectiveness of on-line MS characterization, and provide a new tool for locating sites of unsaturation in biological lipids.

APA, Harvard, Vancouver, ISO, and other styles

2

Zhou, Albert Lihong. "Bioactivities of Milk Polar Lipids in Influencing Intestinal Barrier Integrity, Systemic Inflammation, and Lipid Metabolism." DigitalCommons@USU, 2013. http://digitalcommons.usu.edu/etd/1517.

Full text

Abstract:

The purpose of lactation is for nutrient provision and also importantly for protection from various environmental stressors. Milk polar lipids reduce cholesterol, protect against bacterial infection, reduce inflammation and help maintain gut integrity. Dynamic interactions within dietary fat, lipid metabolism, gut permeability and inflammatory cytokines remain unclear in the context of obesity and systemic inflammation. A rat model and three mouse models were developed to test the hypotheses that dietary milk polar lipids may affect lipid metabolism and intestinal integrity and may protect against systemic inflammation in the context of stressful diet, systemic inflammation, and obesity. The milk polar lipids isolates had complex effects on lipid metabolism and associated gene expression in the rat model. There were complex dynamics in lipid metabolism, gut permeability and systemic inflammation at different time points in all mouse models. The milk phospholipids increased gut permeability in genetic and diet-induced obesity and during the lipopolysaccharide (LPS) -induced inflammation. The phospholipids increased the plasma LPS level in genetic obesity and during the LPS stress. The phospholipids reduced liver mass and liver lipids in genetic obesity and during the LPS-induced inflammation. The phospholipids increased the body fat in the diet-induced obesity model. The milk gangliosides did not significantly affect gut permeability, systemic inflammation, and lipid metabolism in all three mouse models. Current estimate by the Centers for Disease Control is that about 1/3 Americans are obese (body mass index, BMI ≥ 30) and 1/3 Americans are overweight (25 ≤ BMI < 30). More than 25% of Americans today have a fatty liver which could lead to further health problems. The data from this dissertation shed light on the complicated interrelationships between gut permeability, systemic inflammation, and lipid metabolism in obesity. The results contribute to our understanding of the bioactivities of milk polar lipids and provide scientific evidence for the role of milk polar lipids rich materials in affecting biological functions. The study of the influence of milk polar lipids on gut barrier integrity adds new information on understanding the mechanisms of gut leakiness and recovery. The investigation of the impact of milk polar lipids on lipid metabolism reveals new perspectives for the development of diet-induced obesity.

APA, Harvard, Vancouver, ISO, and other styles

3

Cox, Andrew David. "Pseudomonas cepacia : lipopolysaccharides and polar lipids of the cell wall." Thesis, University of Hull, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.306158.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Burnham, Kikue S. ""Effect of aeration on the biosynthesis of highly polar acidic lipids in saccharomyces cerevisiae"." Thesis, Georgia Institute of Technology, 1991. http://hdl.handle.net/1853/25405.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Wang, Weijie. "Tuna oil degumming and analysis of polar lipids by capillary electrophoresis." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ39705.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Finnie, Sean McIlwain. "Wheat polar lipids : sources of variation among near-isogenic wheat lines with different endosperm hardness." Diss., Manhattan, Kan. : Kansas State University, 2009. http://hdl.handle.net/2097/1384.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Costa, Elisabete Valente da. "High value-added products from macroalgae: lipids as bioactive compounds." Doctoral thesis, Universidade de Aveiro, 2018. http://hdl.handle.net/10773/22884.

Full text

Abstract:

Doutoramento em Química Sustentável<br>Marine macroalgae are considered to be interesting for food in Western countries and an important supply of novel natural bioactive compounds. Among these are polar lipids such as glycolipids, betaine lipids and phospholipids recognized as high valued lipids for nutrition and as functional ingredient with recognized health benefits. Its biosynthesis depends on several environmental factors such as seasonality, nutrition and habitat, increasing the structural complexity of macroalga lipidome, so that its identification is a current challenge. Mass spectrometry (MS) is a promising tool successfully applied in the study of lipidomic signature of distinct organisms, which can be extended to identify the hundreds of species in the lipidome of macroalgae, and allow them to finally be explored as potential source of lipids. In this work we aim to identify the lipidome of macroalgae representative of Chlorophyta (Codium tomentosum), Rhodophyta (Gracilaria sp. and Porphyra dioica) and Ochrophyta (Fucus vesiculosus). These algae thrive in the Portuguese coast but are recently being cultivated on an integrated multitrophic aquaculture system (IMTA). The characterization of the lipidome will be performed by using mass spectrometry analysis tools coupled to chromatographic methods. We aim to evaluate the bioactive properties of the polar lipids from macroalgae fostering the potential application of these compounds in function of its biological properties as anti-inflammatory and antiproliferative/antitumor agents. The main goals of this project were achieved after the characterization by using HILIC–MS and MS/MS approaches of the lipid extracts carrying on different extraction protocols. The results of this study allowed to identify about 238 molecular species distributed by twelve classes in the macroalgae Codium tomentosum, 147 molecular species in fourteen classes in Gracilaria sp., 110 molecular species in fourteen classes in Porphyra dioica and 181 molecular species distributed by seventeen classes in Fucus vesiculosus. Overall, the lipidome of these macroalgae included GLs monogalactosyl diacylglycerol (MGDG), digalactosyl diacylglycerol (DGDG), sulfoquinovosyl diacylglycerol (SQDG) and its lyso-form (SQMG); phosphatidylcholine (PC) and lyso-PC, phosphatidylglycerol (PG), lyso-PG (LPG), phosphatidic acid (PA), phosphatidylinositol (PI) and betaines (diacylglyceryl trimethyl-homoserine, DGTS). Green macroalgae may be differentiated by the predominance of molecular species including C16 – C20, polyunsaturated fatty acids (PUFA) such as 16:3, 18:3 and 20:5 from n-3 FA family. It contains several molecular species belonging to GLs and betaines including monoacylglyceryl trimethylhomoserine (MGTS), never reported before in the lipidome of macroalga. Red macroalgae are differentiated by molecular species that incorporate C20 FA chains of n-3 and n-6 families, mainly reflected on the composition of GLs.<br>As macroalgas vermelhas diferenciam-se pelo elevado número de espécies moleculares que incluem cadeias de ácidos gordos C20 da família n-3 e n-6, principalmente na composição dos GLs, e pela presença das classes fosfatidiletanolamina (PE) e inositolfosfoceramida (IPC), apenas identificada nestas algas, pelo que podem ser consideradas um biomarcador deste filo. Neste trabalho, foi avaliada a variação na assinatura lipidómica em duas fases do ciclo de vida (gametófita e esporófita) tomando como alga de estudo a Porphyra dioica. Os resultados obtidos indicaram variações a nível molecular nas classes PC, PA, PE e PG. Em ambas as fases não se observam variações na assinatura dos GLs. O estudo do perfil em ácidos gordos desta alga mostrou que ambas as fases contêm ácidos gordos do tipo 20:4(n-6) e 20:5(n- 3), pelo que apresentam elevado valor nutricional. Na composição da macroalga castanha Fucus vesiculosus, as espécies moleculares combinam diversos ácidos gordos polinsaturados com 18 e 20 átomos de carbono da família n-3 (18:3, 18:4 e 20:5), e 20:4 da família n-6. As algas castanhas apresentam várias espécies moleculares na categoria das betaínas nomeadamente a classe diacilglicerol trimetil-β-alanina (DGTA) e a sua forma liso MGTA, identificada pela primeira vez no lipidoma de macroalgas, ambas não detetadas no lipidoma dos restantes filo. O efeito da sazonalidade na variação da assinatura lipidómica foi estudado para a Fucus vesiculosus colhida em duas estações do ano: inverno e primavera. Os resultados obtidos mostram que o lipidoma desta macroalga mantém o mesmo número de espécies moleculares em todas as classes de lípidos polares, observando-se um aumento da abundância relativa das espécies moleculares que combinam ácidos gordos polinsaturados C18 e C20 (18:3, 18:4, 20:4 e 20:5), em especial nas categorias GLs e betaínas na macroalga de inverno. Assim, podemos concluir que a sazonalidade tem efeito no lipidoma, manifestado pelo aumento de ácidos gordos incorporados nos lípidos polares na macroalga de inverno, muito benéfico em termos nutricionais. Quanto à bioprospecção, avaliaram-se as atividades antiinflamatória e antiproliferativa do extrato lipídico total da macroalga Gracilaria sp.. A atividade anti-inflamatória foi avaliada pela capacidade de inibição dos extratos na produção de NO em macrófagos RAW 264.7 estimulados com o lipopolissacarídeo bacteriano e a atividade anti proliferativa foi testada quanto à capacidade inibitória na proliferação de células T-47D, originadas a partir de um carcinoma ductal humano (cancro da mama) e de células 5637 originadas a partir do carcinoma humano da bexiga. Os extratos totais demonstraram atividade anti-inflamatória e antiproliferativa, pelo que se avaliou o efeito do extrato rico em glicolípidos e a capacidade inibitória na proliferação de células T-47D, verificando-se uma capacidade inibitória da mesma ordem obtida para o extrato total, pelo que poderão ter particular interesse como fitoquímicos. Assim, os resultados obtidos podem contribuir para a valorização das macroalgas como fonte natural e renovável de alimentos, tendo em consideração o valor nutricional como fonte de ácidos gordos n-3 e n-6, e de compostos bioativos a ser utilizados como ingredientes funcionais, fitoquímicos e noutras potenciais aplicações na indústria alimentar e farmacêutica.

APA, Harvard, Vancouver, ISO, and other styles

8

Hauff, Simone [Verfasser]. "Methyl-Branched Fatty Acids and Chiral Anteiso-Fatty Acids in Neutral and Polar Lipids of Biological Samples / Simone Hauff." Aachen : Shaker, 2010. http://d-nb.info/108188570X/34.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Azevedo, Vítor Manuel Madureira. "Lipidomic study of the red marine macroalgae as source of bioactive compounds." Master's thesis, Universidade de Aveiro, 2016. http://hdl.handle.net/10773/17513.

Full text

Abstract:

Mestrado em Mestre em Bioquímica, ramo da Bioquímica Clínica<br>Marine macroalgae, or seaweeds, have gained an increased interest in recent times for the use in various biotechnological applications, due to the added-value of their chemical constituents. Among them, glycolipids and phospholipids display several commercial applications in a wide spectrum of industries, such as food, pharmaceutical and cosmetic. In an effort to further understand the lipid composition of macroalgae, the present work reports, for the first time, the isolation and characterization of the polar lipid profile of the red macroalgae Porphyra dioica cultivated on a land-based integrated multi-trophic aquaculture (IMTA) system, using a lipidomic-based approach employing hydrophilic interaction liquid chromatography-eletrospray ionization mass spectrometry (HILIC-ESI-MS). The fatty acid profile of this species of seaweed was also determined, accounting for season variability and its life cycle. The polar lipid profile of P. dioica revealed the presence of over 69 molecular species, corresponding to glycolipids (sulfoquinovolsyldiacylglycerols, sulfoquinovosylmonoacylglycerols, digalactosyldiacylglycerols) and glycerophospholipids (lyso- and phosphatidylglycerols), lyso- and phosphatidylcholines), as well as phytyl derivatives. Some of these polar lipids contain polyunsaturated fatty acids (PUFAs), namely arachidonic acid (C20:4) and eicosapentaenoic acid (C20:5), thus revealing the ability of P. dioica to biosynthesize this long chain PUFAs. P.dioica from the winter season revealed to be richer in PUFA content, accounting for 37.0% of total fatty acid (TFA) content, as opposed to P. dioica from the summer season (25.0% of TFA content). Eicosapentaenoic acid (EPA) content was revealed to be being significantly higher in the winter season (25.2% of TFA content). The diploid sporophyte conchocelis phase of P. dioica showed to possess the highest amount of PUFAs (47.0% of TFA content), with arachidonic acid being the most abundant fatty acid (21.2% of TFA content). Several of the lipids identified have been reported to possess nutritional and health benefits, thus allowing the valorisation of P. dioica from IMTA as a source of bioactive compounds, adequate for the use in a wide range of different applications and as a functional food, rich in omega-3 fatty acids.<br>As macroalgas têm vindo a ganhar um interesse cada vez maior para o uso em diversas aplicações biotecnológicas, devido ao valor acrescentado dos seus diferentes constituintes. Entre estes, os glicolípidos e os fosfolípidos podem ser usados comercialmente em diferentes indústrias, tais como as indústrias alimentar, farmacêutica e cosmética. Com o objetivo de compreender melhor a composição lipídica das macroalgas, o presente trabalho relata, pela primeira vez, a caracterização do perfil de lípidos polares da macroalga vermelha Porphyra dioica, cultivada num sistema de aquacultura multi-trófica integrada (IMTA), utilizando para esse fim uma abordagem lipidómica baseada na espectrometria de massa (HILIC-ESI-MS). Foi também determinado o perfil de ácidos gordos da referida espécie de alga, tendo em consideração a variabilidade sazonal e o seu ciclo de vida. O perfil de lípidos polares da alga P. dioica revelou a presença de mais de 69 espécies moleculares diferentes, correspondendo a classes de glicolípidos (sulfoquinovosildiacilgliceróis, sulfoquinovosilmonoacilgliceróis e digalactosildiacilgliceróis), fosfolípidos (liso- e fosfatidilglicerol, liso- e fosfatidilcolinas) e derivados fitil. Alguns destes lípidos polares contêm ácidos gordos polinsaturados (PUFAs) na sua composição, nomeadamente o ácido araquidónico (C20:4) e ácido eicosapentaenóico (C20:5), revelando, assim, a capacidade da alga P. dioica em biossintetizar este tipo de ácidos gordos polinsaturados de cadeia longa. Considerando a variação sazonal do conteúdo em ácidos gordos, a P. dioica cultivada no inverno revelou ser mais rica em PUFAs, correspondendo a 37.0% do conteúdo total de ácidos gordos, contrariamente à P. dioica cultivada no verão (25.0%). O conteúdo em ácido eicosapentaenóico (EPA) é significativamente maior na estação de inverno (25.2%). O perfil em ácidos gordos também variou com o ciclo de vida P. dioica, sendo que na fase de conchocelis a quantidade de PUFA é significativamente mais elevada (47.0% de conteúdo de ácidos gordos), sendo o ácido araquidónico o ácido gordo mais abundante (21.2% de conteúdo de ácidos gordos).Várias classes de lípidos polares foram identificados como possuindo benefícios nutricionais e para a saúde, permitindo assim a valorização da alga vermelha P. dioica produzida em IMTA como uma fonte de compostos bioativos, adequados para o uso numa grande variedade de aplicações como um alimento funcional, rica em ácidos gordos polinsaturados ómega-3.

APA, Harvard, Vancouver, ISO, and other styles

10

Huang, Bing. "Réponses physiologiques et biochimiques à une limitation nutritive en phosphore ou en azote sur la réorientation métabolique des lipides polaires chez différentes espèces de microalgues marines." Thesis, Le Mans, 2018. http://www.theses.fr/2018LEMA1021/document.

Full text

Abstract:

Les bétaïne lipides (BL) sont des lipides polaires qui se distinguent des phospholipides (PL)par l’absence de phosphore (P). La réorientation métabolique induite par une limitation en P chez des microalgues produisant des BL (Tisochrysis lutea et Diacronema lutheri, Haptophytes) ou en produisant peu (Phaeodactylum tricornutum, Bacillariophyte) a été comparée à celle induite par une limitation en azote (N). Le devenir et le flux de carbone dans différentes voies de biosynthèse ont été étudiés par une approche pluridisciplinaire.La limitation nutritive en P ou en N affecte différemment le métabolisme du carbone selon les espèces microalgales. La limitation en P réduit fortement l’activité photosynthétique et la respiration chez P. tricornutum et T. lutea. Par conséquent, l’accumulation de carbone est plus élevée que sous limitation en N chez ces deux espèces. Les deux limitations stimulent en particulier la synthèse des lipides neutres et / ou des glucides. Le remplacement des PL par les BL a été observé chez P. tricornutum en condition de limitation en P. Ce résultat est en accord avec une augmentation de la transcription du gène codant la bétaïne lipide synthase. En revanche, cette limitation ne modifie pas les teneurs en BL rapportées au carbone chez T. lutea et D. lutheri. La composition en acides gras des différentes classes lipidiques est modifiée selon l’espèce microalgale et l’élément nutritif limitant. Une attention particulière a été portée aux acides gras de la série oméga-3, notamment l’acide eicosapentaénoïque (EPA, 20:5 ω3) et l’acide docosahexaénoïque (DHA, 22:6 ω3) dont les proportions varient en fonction de l’élément limitant,de l’espèce et de la classe lipidique. L’augmentation de la production des lipides neutres et / ou des lipides polaires, notamment des bétaïne lipides, riches en DHA et/ou EPA induite par un stress nutritif laisse envisager une valorisation de ces molécules d’intérêt dans différents domaines dont la nutrition et la santé<br>Betaine lipids (BL) are P-free polar lipids, conversely to phospholipids (PL). The metabolic reorientation induced by phosphorus (P) limitation in microalgae producing BL (Tisochrysis lutea and Diacronema lutheri, Haptophyta) or producing low levels of BL (Phaeodactylum tricornutum, Bacillariophyta) was compared to that induced by nitrogen (N) limitation. The carbon destiny and flow in different biosynthetic pathways were studied with a multidisciplinary approach. P or N limitation differently affected carbon metabolism according to microalgal species. P limitation highly decreased photosynthetic activity and respiration of P. tricornutum and T. lutea. Consequently, carbon accumulation was higher than under N limitation in these two species. Both limitations stimulated the synthesis of neutral lipids and / or carbohydrates. Replacement of PL by BL was observed in P. tricornutum under P limitation. This result is in agreement with a transcription increase of the gene encoding BL synthase. On the other hand, this limitation did not modify BL contents in reference with carbon in T. lutea or D. lutheri. Fatty acid composition of the different lipid classes was modified according to the microalgal species and the limiting nutrient. Particular attention was paid to the fatty acids of the omega-3 series, notably eicosapentaenoic acid (EPA, 20:5 ω3) and docosahexaenoic acid (DHA, 22:6 ω3), the proportions of which vary according to the limiting element, species and lipid class. The increase in the production of neutral lipids and / or polar lipids, especially betaine lipids, rich in DHA and / or EPA induced by nutritive stress suggests a valorization of these molecules of interest in various areas including nutrition and health

APA, Harvard, Vancouver, ISO, and other styles

Books on the topic "Polar lipids"

1

Polar lipids: Biology, chemistry, and technology. AOCS Press, 2015.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

2

Mohammed, Fathi Sadek. Analysis of polar lipids of fusobacterium spp. by FAB-MS. University ofManchester, 1997.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

3

Polar Lipids. Elsevier, 2015. http://dx.doi.org/10.1016/c2015-0-02381-4.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Clarke, Andrew. Temperature, growth and size. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780199551668.003.0013.

Full text

Abstract:

Growth involves two flows of energy. The first is chemical potential energy in the monomers used to construct the proteins, lipids, polysaccharides and nucleic acids forming the new tissue. The second is the metabolic energy (ATP or GTP) used to construct the new tissue; this is the metabolic cost of growth and can be expressed as a dimensionless fraction of the energy retained in the new tissue. Its value is ~0.33. Typical temperature sensitivities for growth in the wild lie in the range Q10 1.5 – 3. Within species there may be evolutionary adjustments to growth rate to offset the effects of temperature, though these involve trade-offs with other physiological factors affecting fitness. Outside the tropics, many mammals and birds exhibit a cline in size, with larger species at higher latitudes (Bergmann’s rule). Carl Bergmann predicted such a cline from biophysical arguments based on endotherm thermoregulatory costs; Bergmann’s rule thus applies only to mammals and birds. Many ectotherms grow more slowly but attain a larger adult size when grown at lower temperatures (the temperature-size rule). The large size of some aquatic invertebrates at lower temperatures (notably in the polar regions and the deep sea) is associated with a higher oxygen content of the water.

APA, Harvard, Vancouver, ISO, and other styles

5

Rifat, Raisa, Habib Abdurahman Izzudin, Fajar Ajie Setiawan, et al. Indonesia Emas Berkelanjutan 2045: Kumpulan Pemikiran Pelajar Indonesia Sedunia Seri 7 Lingkungan. Edited by Radityo Pangestu, Raisa Rifat, Desy Ayu Prihardini, and Februriyana Pirade. LIPI Press, 2021. http://dx.doi.org/10.14203/press.359.

Full text

Abstract:

LIPI Press berkolaborasi dengan Perhimpunan Pelajar Indonesia (PPI) Dunia menerbitkan rangkaian buku seri Indonesia Emas Berkelanjutan 2045: Kumpulan Pemikiran Pelajar Indonesia Sedunia. Rangkaian bunga rampai ini terdiri dari 12 buku dengan sejumlah topik yang mendukung Tujuan Pembangunan Berkelanjutan atau Sustainable Development Goals (SDGs) untuk mencapai tujuan Indonesia Emas 2045. Buku ini merupakan seri ketujuh dari rangkaian tersebut. Seri Lingkungan ini ditulis berangkat dari kekhawatiran bahwa kebijakan lingkungan yang telah ada selama ini keliru. Buku ini mendukung empat target dari SDGs, yaitu manajemen sanitasi dan air bersih (poin 6), pola konsumsi dan produksi yang berkelanjutan (poin 12), penanganan perubahan iklim (poin 13), dan ekosistem daratan (poin 15). Isu lingkungan menjadi sentral dan sangat menarik untuk dibahas karena besar pengaruhnya terhadap isu-isu lain, seperti ekonomi, politik, dan budaya. Buku ini diharapkan dapat menjadi bacaan yang bermanfaat bagi masyarakat Indonesia, khususnya para pembuat kebijakan dan pemangku kepentingan di bidang lingkungan. Temukan sumbangsih pemikiran, saran, solusi, dan analisis dari perwakilan pelajar Indonesia di seluruh dunia terkait pengelolaan dan peningkatan kualitas lingkungan hidup Indonesia.

APA, Harvard, Vancouver, ISO, and other styles

Book chapters on the topic "Polar lipids"

1

Bourlieu, Claire, Nathalie Barouh, Jeanne Kergomard, et al. "Polar Lipids." In Handbook of Dairy Foods Analysis, 2nd ed. CRC Press, 2021. http://dx.doi.org/10.1201/9780429342967-10.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Gounaris, Kleoniki. "Thylakoid Membrane Polar Lipids." In Techniques and New Developments in Photosynthesis Research. Springer US, 1989. http://dx.doi.org/10.1007/978-1-4684-8571-4_21.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Lordan, Ronan, Constantina Nasopoulou, Alexandros Tsoupras, and Ioannis Zabetakis. "The Anti-inflammatory Properties of Food Polar Lipids." In Bioactive Molecules in Food. Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-319-78030-6_95.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Barry, Kate M., Timothy G. Dinan, and Philip M. Kelly. "Preparation and Applications of Milk Polar Lipids/MFGM." In Dairy Fat Products and Functionality. Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-41661-4_4.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Lordan, Ronan, Constantina Nasopoulou, Alexandros Tsoupras, and Ioannis Zabetakis. "The Anti-inflammatory Properties of Food Polar Lipids." In Bioactive Molecules in Food. Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-54528-8_95-1.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Pham Thi, A. T., L. El-Hafid, Y. Zully-Fodil, and J. Vieira da Silva. "Enzymatic Breakdown of Polar Lipids in Cotton Leaves Under Water Stress." In Biological Role of Plant Lipids. Springer US, 1989. http://dx.doi.org/10.1007/978-1-4684-1303-8_116.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Pham Thi, A. T., F. Monteiro de Paula, G. Herbert, A. M. Justin, C. Demandre, and P. Mazliak. "Effects of Water Stress on Molecular Species Composition of Polar Lipids from Vigna Unguiculata Leaves." In Biological Role of Plant Lipids. Springer US, 1989. http://dx.doi.org/10.1007/978-1-4684-1303-8_117.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Montero, Olimpio, Javier Fontecha, M. Pillar Castro-Gómez, and Luis Miguel Rodríguez-Alcalá. "Lipidomic Characterization of the Milk Fat Globule Membrane Polar Lipids." In Dairy Fat Products and Functionality. Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-41661-4_5.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Banas, A., Ingemar Johansson, G. Stenlid, and S. Stymne. "Influence of Haloxyfop-Ethoxyethyl (Grass Herbicide) on Polar Lipids in Tolerant (Pea) and Sensitive (Oat, Wheat) Plants." In Biological Role of Plant Lipids. Springer US, 1989. http://dx.doi.org/10.1007/978-1-4684-1303-8_93.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Rilfors, Leif, Åke Wieslander, and Göran Lindblom. "Regulation and Physicochemical Properties of the Polar Lipids in Acholeplasma laidlawii." In Subcellular Biochemistry. Springer US, 1993. http://dx.doi.org/10.1007/978-1-4615-2924-8_4.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Polar lipids"

1

Чадова, Оксана Андреевна, and Петр Владимирович Веланский. "FATTY ACID COMPOSITION OF ENDOPHYTIC MICROALGAE LAMINARIOCOLAX AECIDIOIDES, STREBLONEMA CORYMBIFERUM AND STREBLONEMA SP. (ECTOCARPALES, PHAEOPHYCEAE)." In Наука. Исследования. Практика: сборник избранных статей по материалам Международной научной конференции (Санкт-Петербург, Апрель 2021). Crossref, 2021. http://dx.doi.org/10.37539/srp296.2021.41.36.008.

Full text

Abstract:

Впервые исследован жирнокислотный состав полярных и нейтральных липидов бурых эндофитных микроводорослей Laminariocolax aecidioides, Streblonema corymbiferum и Streblonema sp. Показано, что в состав полярных липидов входят главным образом полиненасыщенные жирные кислоты, такие как 18:3ω-3, 18:4ω-3 и 20:5ω-3. Во фракциях нейтральных липидов всех образцов доминировали насыщенные жирные кислоты 14:0 и 16:0, мононенасыщенная 18:1ω-9 и полиненасыщенная 18:2ω6. Отмечена высокая концентрация 16:1ω-7 в нейтральной фракции Streblonema sp. Во всех липидных фракциях эндофитов, кроме нейтральных липидов S. corymbiferum, обнаружены гидроксилированные жирные кислоты 22:0Δ2-OH и 24:0Δ2-OH. The fatty acid composition of polar and neutral lipids of brown endophytic microalgae Laminariocolax aecidioides , Streblonema corymbiferum and Streblonema sp. was investigated for the first time. It was shown that the composition of polar lipids of endophytes includes mainly polyunsaturated fatty acids, such as 18:3ω-3, 18:4ω-3 and 20: 5ω-3. Saturated 14:0 and 16:0, monounsaturated 18:1ω-9 and polyunsaturated 18:2ω6 dominated the neutral lipids of all samples. A high concentration of 16:1ω-7 was observed in the neutral fraction of Streblonema sp. Hydroxylated fatty acids 22:0Δ2-OH and 24:0Δ2-OH were found in all lipid fractions, except for neutral lipids of S. corymbiferum .

APA, Harvard, Vancouver, ISO, and other styles

2

Wei, Wei, and Xingguo Wang. "Polar Lipids in Human Milk and Its Potential Functions." In Virtual 2021 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2021. http://dx.doi.org/10.21748/am21.209.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Blesso, Christopher. "Milk Polar Lipids: Potential for Management of Dysfunctional Lipid Metabolism, Gut Dysbiosis, and Chronic Inflammation." In Virtual 2021 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2021. http://dx.doi.org/10.21748/am21.208.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Renthal, Robert. "Analysis of polar cuticular lipids and their roles in semiochemical signaling." In 2016 International Congress of Entomology. Entomological Society of America, 2016. http://dx.doi.org/10.1603/ice.2016.114175.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Peters, C. A., G. T. Ventura, J. Bentley, et al. "Can Intact Polar Lipids from Shallow Marine Sediments be Used to Help De-Risk Petroleum Exploration?" In 29th International Meeting on Organic Geochemistry. European Association of Geoscientists & Engineers, 2019. http://dx.doi.org/10.3997/2214-4609.201902852.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Hadady, Hanieh, Sage R. Hiibel, Doug Redelman, and Emil J. Geiger. "Use of a Separability Parameter for the Design of a High Frequency Dielectrophoresis Cell Sorter Device." In ASME 2015 13th International Conference on Nanochannels, Microchannels, and Minichannels collocated with the ASME 2015 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/icnmm2015-48528.

Full text

Abstract:

We present a method to quantify and enhance separation of binary cells mixture in the microfluidic device using high frequency dielectrophoresis (>20 MHz). At these frequencies, the DEP response depends primarily on the dielectric properties of the cytoplasm. In order to achieve efficient separation, there must be a difference in the intrinsic dielectric properties of the populations to be sorted. For algae cells, the shift in high frequency dielectrophoresis response during lipid accumulation can be used as a basis of separation. We defined a separability parameter based on the expected difference in the dielectrophoresis responses of the algae cells. Chlamydomonas reinhardtii cells were cultured in regular media and then the same cells were cultured under nitrogenfree conditions to accumulate neutral (non-polar) lipids. Separability of microalgae cells with different lipid content via high frequency dielectrophoresis were investigated by a thin needle shaped electrodes patterned by standard photolithographic and wet etching procedures. Experimental separability factors were measured by estimation of relative lipid content with BODIPY 505/515 fluorescence dye and calculating the area-weighted intensity average of fluorescent images. Theoretical separability parameter was calculated using analytical analysis of single shell model by MATLAB. Theoretical and experimental separability parameters, as tools to determine the optimal separation method, were calculated for microalgae cells with different lipid content. This objective function was maximized in the range of 35–45 MHz for C. reinhardtii cells after 21 days of lipid accumulation in a static separation. In order to design a continuous cell sorter device, the theoretical separation factor was maximized based on differences in the magnitude or the direction of the DEP force.

APA, Harvard, Vancouver, ISO, and other styles

7

Hadady, Hanieh, Johnson J. Wong, Sage R. Hiibel, and Emil J. Geiger. "Effect of Media Conductivity on High Frequency Dielectrophoretic Response." In ASME 2014 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/imece2014-38423.

Full text

Abstract:

A method was developed for analyzing the high frequency dielectrophoresis (>20 MHz) response of microalgal cells with different lipid content on the basis of media conductivities. At these frequencies, the DEP response is expected to depend primarily on the dielectric properties of the cytoplasm. The medium used to perform DEP experiments has an important influence on their outcome since all properties are measured in relation to the medium, therefore its properties must be tightly controlled. This method is label free and only uses electric fields, and thus it is suitable for many other applications in the medical field. Chlamydomonas reinhardtii cells were cultured in regular medium and then the same cells were cultured under nitrogen-free conditions to accumulate neutral (non-polar) lipids. To measure the upper crossover frequency, two thin, needle shaped electrodes (100 nm thick) were patterned onto a glass slide using standard micro-technology processes and the motion of the cells was observed as an AC signal was swept from 20–80 MHz at ∼30Vpp (Volt peak to peak). Cells were injected to the microelectrode array in different medium conductivities that were adjusted by sodium chloride. The upper crossover frequencies of N-free cells in different media conductivities were measured. It was found that when the solution conductivity was between 4 ± 2 μs/cm and 106 ± 1 μS/cm and the operating frequency was between 20 and 80 MHz, the upper crossover frequency of the microalgae increased as the medium conductivity increased. The lipid content was verified via fluorescence microscopy and MATLAB image processing.

APA, Harvard, Vancouver, ISO, and other styles

8

Gunawan, Setiyo, Bo-Ren Jeng, and Yi-Hsu Ju. "Optimization of operating conditions for separation of non polar lipids fraction from soybean oil deodorizer distillate by regenerated silica gel." In 5TH NANOSCIENCE AND NANOTECHNOLOGY SYMPOSIUM (NNS2013). AIP Publishing LLC, 2014. http://dx.doi.org/10.1063/1.4866756.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Evans, T. W., F. J. Elling, Y. Li, A. Pearson, and R. E. Summons. "Realizing the Full Potential of Lipidomics: A New Protool for an Improved Extraction of the Intact Polar Lipids of Archaea." In 30th International Meeting on Organic Geochemistry (IMOG 2021). European Association of Geoscientists & Engineers, 2021. http://dx.doi.org/10.3997/2214-4609.202134147.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Michalski, Marie-Caroline, Cécile Vors, Laurie Joumard-Cubizolles, et al. "Milk Polar Lipid Supplementation Improves Cholesterol Metabolism in Postmenopausal Women: Gut-Related Mechanisms." In Virtual 2020 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2020. http://dx.doi.org/10.21748/am20.114.

Full text

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!