WorldWideScience

Sample records for polar lipids comprised

  1. Integrated optical circuit comprising a polarization convertor

    NARCIS (Netherlands)

    1998-01-01

    An integrated optical circuit includes a first device and a second device, which devices are connected by a polarization convertor. The polarization convertor includes a curved section of a waveguide, integrated in the optical circuit. The curved section may have several differently curved

  2. Polar lipid composition of mammalian hair.

    Science.gov (United States)

    Wix, M A; Wertz, P W; Downing, D T

    1987-01-01

    The types and amounts of polar lipids from the hair of monkey (Macacca fascicularis), dog (Canis familiaris), pig (Sus scrofa) and porcupine (Erethizon dorsatum) have been determined by quantitative thin-layer chromatography. The polar lipid content of the hair samples ranged from 0.6 to 1.6 wt%. Lipid compositions included ceramides (57-63% of the polar lipid by weight), glycosphingolipids (7-9%) and cholesteryl sulfate (22-29%). Several minor components (4-7%) remain unidentified. The results suggest that cholesteryl sulfate may be an important determinant of the cohesiveness of hair.

  3. Alcohol dose dumping: The influence of ethanol on hot-melt extruded pellets comprising solid lipids.

    Science.gov (United States)

    Jedinger, N; Schrank, S; Mohr, S; Feichtinger, A; Khinast, J; Roblegg, E

    2015-05-01

    The objective of the present study was to investigate interactions between alcohol and hot-melt extruded pellets and the resulting drug release behavior. The pellets were composed of vegetable calcium stearate as matrix carrier and paracetamol or codeine phosphate as model drugs. Two solid lipids (Compritol® and Precirol®) were incorporated into the matrix to form robust/compact pellets. The drug release characteristics were a strong function of the API solubility, the addition of solid lipids, the dissolution media composition (i.e., alcohol concentration) and correspondingly, the pellet wettability. Pellets comprising paracetamol, which is highly soluble in ethanol, showed alcohol dose dumping regardless of the matrix composition. The wettability increased with increasing ethanol concentrations due to higher paracetamol solubilities yielding increased dissolution rates. For pellets containing codeine phosphate, which has a lower solubility in ethanol than in acidic media, the wettability was a function of the matrix composition. Dose dumping occurred for formulations comprising solid lipids as they showed increased wettabilities with increasing ethanol concentrations. In contrast, pellets comprising calcium stearate as single matrix component showed robustness in alcoholic media due to wettabilities that were not affected by the addition of ethanol. The results clearly indicate that the physico-chemical properties of the drug and the matrix systems are crucial for the design of ethanol-resistant dosage forms. Moreover, hydrophobic calcium stearate can be considered a suitable matrix system that minimizes the risk of ethanol-induced dose dumping for certain API's. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Research progress on polar lipids of deinococcus radiodurans

    International Nuclear Information System (INIS)

    Feng Qiong; Tian Bing; Hua Yuejin

    2013-01-01

    Deinococcus radiodurans is extremely resistant to radiation, desiccation, oxidizing agents and other extreme conditions. One of the unique lipids in Deinococcus radiodurans is the polar lipid phosphoglycolipid with alkylamine as the main component. Alkylamine derived from fatty acids. The composition characteristic of lipids is one of the classification criterias of Deinococcus. This article provided an overview of the main features of the Deinococcus radiodurans and introduced special polar lipids that have been found as well as the taxonomy significances of such lipids. The research progress of the relationship between lipids and their resistance mechanisms and the prospects of special lipids in Deinococcus radidurans have also been discussed. (authors)

  5. Structural and physicochemical properties of polar lipids from thermophilic archaea.

    Science.gov (United States)

    Ulrih, Natasa Poklar; Gmajner, Dejan; Raspor, Peter

    2009-08-01

    The essential general features required for lipid membranes of extremophilic archaea to fulfill biological functions are that they are in the liquid crystalline phase and have extremely low permeability of solutes that is much less temperature sensitive due to a lack of lipid-phase transition and highly branched isoprenoid chains. Many accumulated data indicate that the organism's response to extremely low pH is the opposite of that to high temperature. The high temperature adaptation does not require the tetraether lipids, while the adaptation of thermophiles to acidic environment requires the tetraether polar lipids. The presence of cyclopentane rings and the role of polar heads are not so straightforward regarding the correlations between fluidity and permeability of the lipid membrane. Due to the unique lipid structures and properties of archaeal lipids, they are a valuable resource in the development of novel biotechnological processes. This microreview focuses primarily on structural and physicochemical properties of polar lipids of (hyper)thermophilic archaea.

  6. Polar lipids of Burkholderia pseudomallei induce different host immune responses.

    Directory of Open Access Journals (Sweden)

    Mercedes Gonzalez-Juarrero

    Full Text Available Melioidosis is a disease in tropical and subtropical regions of the world that is caused by Burkholderia pseudomallei. In endemic regions the disease occurs primarily in humans and goats. In the present study, we used the goat as a model to dissect the polar lipids of B. pseudomallei to identify lipid molecules that could be used for adjuvants/vaccines or as diagnostic tools. We showed that the lipidome of B. pseudomallei and its fractions contain several polar lipids with the capacity to elicit different immune responses in goats, namely rhamnolipids and ornithine lipids which induced IFN-γ, whereas phospholipids and an undefined polar lipid induced strong IL-10 secretion in CD4(+ T cells. Autologous T cells co-cultured with caprine dendritic cells (cDCs and polar lipids of B. pseudomallei proliferated and up-regulated the expression of CD25 (IL-2 receptor molecules. Furthermore, we demonstrated that polar lipids were able to up-regulate CD1w2 antigen expression in cDCs derived from peripheral blood monocytes. Interestingly, the same polar lipids had only little effect on the expression of MHC class II DR antigens in the same caprine dendritic cells. Finally, antibody blocking of the CD1w2 molecules on cDCs resulted in decreased expression for IFN-γ by CD4(+ T cells. Altogether, these results showed that polar lipids of B. pseudomallei are recognized by the caprine immune system and that their recognition is primarily mediated by the CD1 antigen cluster.

  7. Polar Lipids of Burkholderia pseudomallei Induce Different Host Immune Responses

    Science.gov (United States)

    Gonzalez-Juarrero, Mercedes; Mima, Naoko; Trunck, Lily A.; Schweizer, Herbert P.; Bowen, Richard A.; Dascher, Kyle; Mwangi, Waithaka; Eckstein, Torsten M.

    2013-01-01

    Melioidosis is a disease in tropical and subtropical regions of the world that is caused by Burkholderia pseudomallei. In endemic regions the disease occurs primarily in humans and goats. In the present study, we used the goat as a model to dissect the polar lipids of B. pseudomallei to identify lipid molecules that could be used for adjuvants/vaccines or as diagnostic tools. We showed that the lipidome of B. pseudomallei and its fractions contain several polar lipids with the capacity to elicit different immune responses in goats, namely rhamnolipids and ornithine lipids which induced IFN-γ, whereas phospholipids and an undefined polar lipid induced strong IL-10 secretion in CD4+ T cells. Autologous T cells co-cultured with caprine dendritic cells (cDCs) and polar lipids of B. pseudomallei proliferated and up-regulated the expression of CD25 (IL-2 receptor) molecules. Furthermore, we demonstrated that polar lipids were able to up-regulate CD1w2 antigen expression in cDCs derived from peripheral blood monocytes. Interestingly, the same polar lipids had only little effect on the expression of MHC class II DR antigens in the same caprine dendritic cells. Finally, antibody blocking of the CD1w2 molecules on cDCs resulted in decreased expression for IFN-γ by CD4+ T cells. Altogether, these results showed that polar lipids of B. pseudomallei are recognized by the caprine immune system and that their recognition is primarily mediated by the CD1 antigen cluster. PMID:24260378

  8. The Effect of Polar Lipids on Tear Film Dynamics

    KAUST Repository

    Aydemir, E.

    2010-06-17

    In this paper, we present a mathematical model describing the effect of polar lipids, excreted by glands in the eyelid and present on the surface of the tear film, on the evolution of a pre-corneal tear film. We aim to explain the interesting experimentally observed phenomenon that the tear film continues to move upward even after the upper eyelid has become stationary. The polar lipid is an insoluble surface species that locally alters the surface tension of the tear film. In the lubrication limit, the model reduces to two coupled non-linear partial differential equations for the film thickness and the concentration of lipid. We solve the system numerically and observe that increasing the concentration of the lipid increases the flow of liquid up the eye. We further exploit the size of the parameters in the problem to explain the initial evolution of the system. © 2010 Society for Mathematical Biology.

  9. The Effect of Polar Lipids on Tear Film Dynamics

    KAUST Repository

    Aydemir, E.; Breward, C. J. W.; Witelski, T. P.

    2010-01-01

    In this paper, we present a mathematical model describing the effect of polar lipids, excreted by glands in the eyelid and present on the surface of the tear film, on the evolution of a pre-corneal tear film. We aim to explain the interesting

  10. Affinity of four polar neurotransmitters for lipid bilayer membranes

    DEFF Research Database (Denmark)

    Wang, Chunhua; Ye, Fengbin; Valardez, Gustavo F.

    2011-01-01

    . The simulations suggest that this attraction mainly relies on electrostatic interactions of the amino group of the neurotransmitter and the lipid phosphate. We conclude that moderate attraction to lipid membranes occurs for some polar neurotransmitters and hence that one premise for a theory of bilayer-mediated......Weak interactions of neurotransmitters and the lipid matrix in the synaptic membrane have been hypothesized to play a role in synaptic transmission of nerve signals, particularly with respect to receptor desensitization (Cantor, R. S. Biochemistry 2003, 42, 11891). The strength of such interactions......, however, was not measured, and this is an obvious impediment for further evaluation and understanding of a possible role for desensitization. We have used dialysis equilibrium to directly measure the net affinity of selected neurotransmitters for lipid membranes and analyzed this affinity data...

  11. Bioactivities of Milk Polar Lipids in Influencing Intestinal Barrier Integrity, Systemic Inflammation, and Lipid Metabolism

    OpenAIRE

    Zhou, Albert Lihong

    2013-01-01

    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 ...

  12. Extraction of microalgal lipids and the influence of polar lipids on biodiesel production by lipase-catalyzed transesterification.

    Science.gov (United States)

    Navarro López, Elvira; Robles Medina, Alfonso; González Moreno, Pedro Antonio; Esteban Cerdán, Luis; Molina Grima, Emilio

    2016-09-01

    In order to obtain microalgal saponifiable lipids (SLs) fractions containing different polar lipid (glycolipids and phospholipids) contents, SLs were extracted from wet Nannochloropsis gaditana microalgal biomass using seven extraction systems, and the polar lipid contents of some fractions were reduced by low temperature acetone crystallization. We observed that the polar lipid content in the extracted lipids depended on the polarity of the first solvent used in the extraction system. Lipid fractions with polar lipid contents between 75.1% and 15.3% were obtained. Some of these fractions were transformed into fatty acid methyl esters (FAMEs, biodiesel) by methanolysis, catalyzed by the lipases Novozym 435 and Rhizopus oryzae in tert-butanol medium. We observed that the reaction velocity was higher the lower the polar lipid content, and that the final FAME conversions achieved after using the same lipase batch to catalyze consecutive reactions decreased in relation to an increase in the polar lipid content. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. The influence of non-polar lipids on tear film dynamics

    KAUST Repository

    Bruna, M.

    2014-04-04

    © 2014 Cambridge University Press. In 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.

  14. Differential effects of Mycobacterium bovis - derived polar and apolar lipid fractions on bovine innate immune cells

    Directory of Open Access Journals (Sweden)

    Pirson Chris

    2012-06-01

    Full Text Available Abstract Mycobacterial lipids have long been known to modulate the function of a variety of cells of the innate immune system. Here, we report the extraction and characterisation of polar and apolar free lipids from Mycobacterium bovis AF 2122/97 and identify the major lipids present in these fractions. Lipids found included trehalose dimycolate (TDM and trehalose monomycolate (TMM, the apolar phthiocerol dimycocersates (PDIMs, triacyl glycerol (TAG, pentacyl trehalose (PAT, phenolic glycolipid (PGL, and mono-mycolyl glycerol (MMG. Polar lipids identified included glucose monomycolate (GMM, diphosphatidyl glycerol (DPG, phenylethanolamine (PE and a range of mono- and di-acylated phosphatidyl inositol mannosides (PIMs. These lipid fractions are capable of altering the cytokine profile produced by fresh and cultured bovine monocytes as well as monocyte derived dendritic cells. Significant increases in the production of IL-10, IL-12, MIP-1β, TNFα and IL-6 were seen after exposure of antigen presenting cells to the polar lipid fraction. Phenotypic characterisation of the cells was performed by flow cytometry and significant decreases in the expression of MHCII, CD86 and CD1b were found after exposure to the polar lipid fraction. Polar lipids also significantly increased the levels of CD40 expressed by monocytes and cultured monocytes but no effect was seen on the constitutively high expression of CD40 on MDDC or on the levels of CD80 expressed by any of the cells. Finally, the capacity of polar fraction treated cells to stimulate alloreactive lymphocytes was assessed. Significant reduction in proliferative activity was seen after stimulation of PBMC by polar fraction treated cultured monocytes whilst no effect was seen after lipid treatment of MDDC. These data demonstrate that pathogenic mycobacterial polar lipids may significantly hamper the ability of the host APCs to induce an appropriate immune response to an invading pathogen.

  15. A Molecular Probe for the Detection of Polar Lipids in Live Cells.

    Science.gov (United States)

    Bader, Christie A; Shandala, Tetyana; Carter, Elizabeth A; Ivask, Angela; Guinan, Taryn; Hickey, Shane M; Werrett, Melissa V; Wright, Phillip J; Simpson, Peter V; Stagni, Stefano; Voelcker, Nicolas H; Lay, Peter A; Massi, Massimiliano; Plush, Sally E; Brooks, Douglas A

    2016-01-01

    Lipids have an important role in many aspects of cell biology, including membrane architecture/compartment formation, intracellular traffic, signalling, hormone regulation, inflammation, energy storage and metabolism. Lipid biology is therefore integrally involved in major human diseases, including metabolic disorders, neurodegenerative diseases, obesity, heart disease, immune disorders and cancers, which commonly display altered lipid transport and metabolism. However, the investigation of these important cellular processes has been limited by the availability of specific tools to visualise lipids in live cells. Here we describe the potential for ReZolve-L1™ to localise to intracellular compartments containing polar lipids, such as for example sphingomyelin and phosphatidylethanolamine. In live Drosophila fat body tissue from third instar larvae, ReZolve-L1™ interacted mainly with lipid droplets, including the core region of these organelles. The presence of polar lipids in the core of these lipid droplets was confirmed by Raman mapping and while this was consistent with the distribution of ReZolve-L1™ it did not exclude that the molecular probe might be detecting other lipid species. In response to complete starvation conditions, ReZolve-L1™ was detected mainly in Atg8-GFP autophagic compartments, and showed reduced staining in the lipid droplets of fat body cells. The induction of autophagy by Tor inhibition also increased ReZolve-L1™ detection in autophagic compartments, whereas Atg9 knock down impaired autophagosome formation and altered the distribution of ReZolve-L1™. Finally, during Drosophila metamorphosis fat body tissues showed increased ReZolve-L1™ staining in autophagic compartments at two hours post puparium formation, when compared to earlier developmental time points. We concluded that ReZolve-L1™ is a new live cell imaging tool, which can be used as an imaging reagent for the detection of polar lipids in different intracellular

  16. Polar snow algae as a valuable source of lipids?

    NARCIS (Netherlands)

    Hulatt, Chris J.; Berecz, Orsolya; Egeland, Einar Skarstad; Wijffels, René H.; Kiron, Viswanath

    2017-01-01

    Microalgae offer excellent opportunities for producing food and fuel commodities, but in colder climates the low growth rates of many varieties may hamper production. In this work, extremophilic Arctic microalgae were tested to establish whether satisfactory growth and lipid production could be

  17. Non-Polar Lipid Components of Human Cerumen

    Czech Academy of Sciences Publication Activity Database

    Stránský, Karel; Valterová, Irena; Kofroňová, Edita; Urbanová, Klára; Zarevúcka, Marie; Wimmer, Zdeněk

    2011-01-01

    Roč. 46, č. 8 (2011), s. 781-788 ISSN 0024-4201 R&D Projects: GA ČR GAP502/10/1734; GA MŠk 2B06024; GA MŠk 2B06007; GA MŠk(CZ) OC10001 Institutional research plan: CEZ:AV0Z40550506; CEZ:AV0Z50380511 Keywords : cerumen * ear wax * lipids * ECL values * ACL values Subject RIV: CC - Organic Chemistry Impact factor: 2.129, year: 2011

  18. Fatty acids of polar lipids in heart tissue are good taxonomic markers ...

    African Journals Online (AJOL)

    The fatty acid profiles in total, neutral and polar lipids in the heart tissues of five freshwater fish species (Nile perch Lates niloticus, Nile tilapia Oreochromis niloticus, marbled lungfish Protopterus aethiopicus, Bagrus docmak and African catfish Clarias gariepinus) from Lakes Victoria and Kyoga were determined ...

  19. The influence of non-polar lipids on tear film dynamics

    KAUST Repository

    Bruna, M.; Breward, C.  J.  W.

    2014-01-01

    © 2014 Cambridge University Press. In 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

  20. Intact polar lipids of ammonia-oxidizing Archaea: Structural diversity anapplication inmolecular ecology

    NARCIS (Netherlands)

    Pitcher, A.

    2011-01-01

    Non-extremophilic Crenarchaeota are ubiquitous, and comprise a major component of the microbial assemblages in many modern-day systems. Several studies have analyzed glycerol dialkyl glycerol tetraether (GDGT) membrane lipids synthesized by Crenarchaeota to interpret the presence, distribution, and

  1. Validation of adipose lipid content as a body condition index for polar bears

    Science.gov (United States)

    McKinney, Melissa A.; Atwood, Todd C.; Dietz, Rune; Sonne, Christian; Iverson, Sara J.; Peacock, Elizabeth

    2014-01-01

    Body condition is a key indicator of individual and population health. Yet, there is little consensus as to the most appropriate condition index (CI), and most of the currently used CIs have not been thoroughly validated and are logistically challenging. Adipose samples from large datasets of capture biopsied, remote biopsied, and harvested polar bears were used to validate adipose lipid content as a CI via tests of accuracy, precision, sensitivity, biopsy depth, and storage conditions and comparisons to established CIs, to measures of health and to demographic and ecological parameters. The lipid content analyses of even very small biopsy samples were highly accurate and precise, but results were influenced by tissue depth at which the sample was taken. Lipid content of capture biopsies and samples from harvested adult females was correlated with established CIs and/or conformed to expected biological variation and ecological changes. However, lipid content of remote biopsies was lower than capture biopsies and harvested samples, possibly due to lipid loss during dart retrieval. Lipid content CI is a biologically relevant, relatively inexpensive and rapidly assessed CI and can be determined routinely for individuals and populations in order to infer large-scale spatial and long-term temporal trends. As it is possible to collect samples during routine harvesting or remotely using biopsy darts, monitoring and assessment of body condition can be accomplished without capture and handling procedures or noninvasively, which are methods that are preferred by local communities. However, further work is needed to apply the method to remote biopsies.

  2. Long term effects on human plasma lipoproteins of a formulation enriched in butter milk polar lipid

    Directory of Open Access Journals (Sweden)

    Nilsson Åke

    2009-10-01

    Full Text Available Abstract Background Sphingolipids (SL, in particular sphingomyelin (SM are important components of milk fat polar lipids. Dietary SM inhibits cholesterol absorption in rats (Nyberg et al. J Nutr Biochem. 2000 and SLs decrease both cholesterol and TG concentrations in lipid- and cholesterol fed APOE*3Leiden mice (Duivenvoorden et al. Am J Clin Nutr. 2006. This human study examines effects of a butter milk formulation enriched in milk fat globule membrane material, and thereby in SLs, on blood lipids in healthy volunteers. In a four week parallel group study with 33 men and 15 women we examined the effects of an SL-enriched butter milk formulation (A and an equivalent control formulation (B on plasma lipid levels. Plasma concentrations of HDL and LDL cholesterol, triacylglycerols (TG, apolipoproteins AI and B, and lipoprotein (a were measured. The daily dose of SL in A was 975 mg of which 700 mg was SM. The participants registered food and drink intake four days before introducing the test formula and the last four days of the test period. Results A daily increase of SL intake did not significantly influence fasting plasma lipids or lipoproteins. In group B TG, cholesterol, LDL, HDL and apolipoprotein B concentrations increased, however, but not in group A after four weeks. The difference in LDL cholesterol was seen primarily in women and difference in TG primarily in men. No significant side effects were observed. Conclusion The study did not show any significant decrease on plasma lipids or lipoprotein levels of an SL-enriched formulation containing 2-3 times more SL than the normal dietary intake on cholesterol, other plasma lipids or on energy intake. The formulation A may, however, have counteracted the trend towards increased blood lipid concentrations caused by increased energy intake that was seen with the B formulation.

  3. Influence of carbon and lipid sources on variation of mercury and other trace elements in polar bears (Ursus maritimus).

    Science.gov (United States)

    Routti, Heli; Letcher, Robert J; Born, Erik W; Branigan, Marsha; Dietz, Rune; Evans, Thomas J; McKinney, Melissa A; Peacock, Elizabeth; Sonne, Christian

    2012-12-01

    In the present study, the authors investigated the influence of carbon and lipid sources on regional differences in liver trace element (As, Cd, Cu, total Hg, Mn, Pb, Rb, Se, and Zn) concentrations measured in polar bears (Ursus maritimus) (n = 121) from 10 Alaskan, Canadian Arctic, and East Greenland subpopulations. Carbon and lipid sources were assessed using δ(13) C in muscle tissue and fatty acid (FA) profiles in subcutaneous adipose tissue as chemical tracers. A negative relationship between total Hg and δ(13) C suggested that polar bears feeding in areas with higher riverine inputs of terrestrial carbon accumulate more Hg than bears feeding in areas with lower freshwater input. Mercury concentrations were also positively related to the FA 20:1n-9, which is biosynthesized in large amounts in Calanus copepods. This result raises the hypothesis that Calanus glacialis are an important link in the uptake of Hg in the marine food web and ultimately in polar bears. Unadjusted total Hg, Se, and As concentrations showed greater geographical variation among polar bear subpopulations compared with concentrations adjusted for carbon and lipid sources. The Hg concentrations adjusted for carbon and lipid sources in Bering-Chukchi Sea polar bear liver tissue remained the lowest among subpopulations. Based on these findings, the authors suggest that carbon and lipid sources for polar bears should be taken into account when one is assessing spatial and temporal trends of long-range transported trace elements. Copyright © 2012 SETAC.

  4. A study of archaeal enzymes involved in polar lipid synthesis linking amino acid sequence information, genomic contexts and lipid composition

    Directory of Open Access Journals (Sweden)

    Hiromi Daiyasu

    2005-01-01

    Full Text Available Cellular membrane lipids, of which phospholipids are the major constituents, form one of the characteristic features that distinguish Archaea from other organisms. In this study, we focused on the steps in archaeal phospholipid synthetic pathways that generate polar lipids such as archaetidylserine, archaetidylglycerol, and archaetidylinositol. Only archaetidylserine synthase (ASS, from Methanothermobacter thermautotrophicus, has been experimentally identified. Other enzymes have not been fully examined. Through database searching, we detected many archaeal hypothetical proteins that show sequence similarity to members of the CDP alcohol phosphatidyltransferase family, such as phosphatidylserine synthase (PSS, phosphatidylglycerol synthase (PGS and phosphatidylinositol synthase (PIS derived from Bacteria and Eukarya. The archaeal hypothetical proteins were classified into two groups, based on the sequence similarity. Members of the first group, including ASS from M. thermautotrophicus, were closely related to PSS. The rough agreement between PSS homologue distribution within Archaea and the experimentally identified distribution of archaetidylserine suggested that the hypothetical proteins are ASSs. We found that an open reading frame (ORF tends to be adjacent to that of ASS in the genome, and that the order of the two ORFs is conserved. The sequence similarity of phosphatidylserine decarboxylase to the product of the ORF next to the ASS gene, together with the genomic context conservation, suggests that the ORF encodes archaetidylserine decarboxylase, which may transform archaetidylserine to archaetidylethanolamine. The second group of archaeal hypothetical proteins was related to PGS and PIS. The members of this group were subjected to molecular phylogenetic analysis, together with PGSs and PISs and it was found that they formed two distinct clusters in the molecular phylogenetic tree. The distribution of members of each cluster within Archaea

  5. Development of a stratum corneum substitute for in vitro percutaneous penetration studies : a skin barrier model comprising synthetic stratum corneum lipids

    NARCIS (Netherlands)

    Jager, Miranda Wilhelmina de

    2006-01-01

    The research outlined in this thesis was focused on the development of a skin barrier model, which can substitute for stratum corneum in diffusion studies. This so-called stratum corneum substitute (SCS) was prepared with reconstituted SC lipids (cholesterol, free fatty acids and ceramides) on a

  6. Development and characterization of controlled release polar lipid microparticles of candesartan cilexetil by solid dispersion

    Science.gov (United States)

    Kamalakkannan, V; Puratchikody, A; Ramanathan, L

    2013-01-01

    Candesartan cilexetil (CC) is a newer class of angiotensin II receptor antagonist used for the treatment of hypertension. The solubility of the CC is very poor and its oral bioavailability is only 15%. The controlledrelease polar lipid microparticles of CC (formulations F1, F2, F3 and F4) were prepared using variable erodible lipophilic excipients like hydrogenated castor oil, stearic acid, cetostearyl alcohol and carnauba wax by fusion method. The particle sizes of polar lipid microparticles were less than 50 microns and they were irregular in shape. Drug content ranged between 98.96 ± 2.1 and 101.9 ± 1.6% were present in all the formulations. The formulation F3 showed better drug release throughout the study period in a controlled release manner. Moreover, the in vitro release showed that all the formulations were best fitted to Higuchi model. Accelerated stability studies indicated that there was no significant changes in the chemical and physical characteristics of the formulated drug product during initial and at the end of the study period. The FTIR and DSC studies showed that there was no interaction between the drug and lipophilic excipients and no polymorphic transitions in all formulations. The X-ray diffraction peak of solid dispersion indicated that the crystalline nature of CC disappeared and no new peaks could be observed, suggesting the absence of interaction between drug and excipients. PMID:24019822

  7. Solubilization and localization of weakly polar lipids in unsonicated egg phosphatidylcholine: A 13C MAS NMR study

    International Nuclear Information System (INIS)

    Hamilton, J.A.; Fujito, D.T.; Hammer, C.F.

    1991-01-01

    The weakly polar lipids cholesteryl ester, triacylglycerol, and diacylglycerol incorporate to a limited extent into the lamellar structure of small unilamellar vesicles. The localization of the carbonyl group(s) at the aqueous interface was detected by [ 13 C]carbonyl chemical shift changes relative to the neat unhydrated lipid. This study uses 13 C NMR to investigate the interactions of thes lipids with unsonicated (multilamellar) phosphatidylcholine, a model system for cellular membranes and surfaces of emulsion particles with low curvature. Magic angle spinning reduced the broad lines of the unsonicated dispersions to narrow lines comparable to those from sonicated dispersions. [ 13 C]Carbonyl chemical shifts revealed incorporation of the three lipids into the lamellar structure of the unsonicated phospholipids and a partial hydration of the carbonyl groups similar to that observed in small vesicles. Other properties of interfacial weakly polar lipids in multilayers were similar to those in small unilamellar bilayers. There is thus a general tendency of weakly polar lipids to incorparate at least to a small extent into the lamellar structure of phospholipids and take on interfacial properties that are distinct from their bulk-phase properties. This pool of surface-located lipid is likely to be directly involved in enzymatyic transformations and protein-mediated transport. The 13 C magic angle spinning NMR method may be generally useful for determining the orientation of molecules in model membranes

  8. Determination of hydrophobic coenzyme a esters and other lipids using a biosensor comprising a modified coenzyme a- and acyl-coa binding protein (acbp)

    DEFF Research Database (Denmark)

    2002-01-01

    , food and feed preparations, tissue extracts, acyl-CoA synthetase reaction media and various laboratory conditions using a modified Coenzyme A- and acyl-CoA binding protein (ACBP) is provided. Furthermore the invention relates to a construct comprising a peptide and a signal moiety for performing...

  9. Thermococcus kodakarensis modulates its polar membrane lipids and elemental composition according to growth stage and phosphate availability

    Directory of Open Access Journals (Sweden)

    Travis B. Meador

    2014-01-01

    Full Text Available We observed significant changes in the elemental and intact polar lipid (IPL composition of the archaeon Thermococcus kodakarensis (KOD1 in response to growth stage and phosphorus supply. Reducing the amount of organic supplements and phosphate in growth media resulted in significant decreases in cell size and cellular quotas of carbon (C, nitrogen (N, and phosphorus (P, which coincided with significant increases in cellular IPL quota and IPLs comprising multiple P atoms and hexose moieties. Relatively more cellular P was stored as IPLs in P-limited cells (2-8% compared to control cells (< 0.8%. We also identified a specific IPL biomarker containing a phosphatidyl-N-acetylhexoseamine headgroup that was relatively enriched during rapid cell division. These observations serve as empirical evidence of IPL adaptations in Archaea that will help to interpret the distribution of these biomarkers in natural systems. The reported cell quotas of C, N, and P represent the first such data for a specific archaeon and suggest that thermophiles are C-rich compared to the cell carbon-to-volume relationship reported for planktonic bacteria.

  10. Conversion of polar and non-polar algae oil lipids to fatty acid methyl esters with solid acid catalysts--A model compound study.

    Science.gov (United States)

    Asikainen, Martta; Munter, Tony; Linnekoski, Juha

    2015-09-01

    Bio-based fuels are becoming more and more important due to the depleting fossil resources. The production of biodiesel from algae oil is challenging compared to terrestrial vegetable oils, as algae oil consists of polar fatty acids, such as phospholipids and glycolipids, as well as non-polar triglycerides and free fatty acids common in vegetable oils. It is shown that a single sulphonated solid acid catalyst can perform the esterification and transesterification reactions of both polar and non-polar lipids. In mild reaction conditions (60-70 °C) Nafion NR50 catalyst produces methyl palmitate (FAME) from the palmitic acid derivatives of di-, and tri-glyceride, free fatty acid, and phospholipid with over 80% yields, with the glycolipid derivative giving nearly 40% yields of FAME. These results demonstrate how the polar and non-polar lipid derivatives of algal oil can be utilised as feedstocks for biodiesel production with a single catalyst in one reaction step. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Analysis by Mass Spectrometry of the Polar Lipids from the Cellular Membrane of Thermophilic Lactic Acid Bacteria

    Directory of Open Access Journals (Sweden)

    A. M. Seldes

    2000-03-01

    Full Text Available Fast atom bombardment (FAB technique was employed to determine the structure of polar lipids from the cellular membrane of Lactobacillus delbruekii ssp. bulgaricus and Streptococcus salivarius ssp. thermophilus. Analysis of spectra provided useful information about the molecular species and aminoacids constituents of the samples.

  12. Comparison of extraction and work up techniques for analysis of core and intact polar tetraether lipids from sedimentary environments

    NARCIS (Netherlands)

    Lengger, S.K.; Hopmans, E.C.; Sinninghe Damsté, J.S.; Schouten, S.

    2012-01-01

    Glycerol dibiphytanyl glycerol tetraether-based intact polar lipids (IPL GDGTs) are used as biomarkers for living Archaea and are analyzed utilizing a variety of extraction and quantification techniques. Most IPL GDGT studies have used a modified Bligh-Dyer extraction method, but it has been

  13. A single step reversed-phase high performance liquid chromatography separation of polar and non-polar lipids.

    Science.gov (United States)

    Olsson, Petter; Holmbäck, Jan; Herslöf, Bengt

    2014-11-21

    This paper reports a simple chromatographic system to separate lipids classes as well as their molecular species. By the use of phenyl coated silica as stationary phase in combination with a simple mobile phase consisting of methanol and water, all tested lipid classes elute within 30 min. Furthermore, a method to accurately predict retention times of specific lipid components for this type of chromatography is presented. Common detection systems were used, namely evaporative light scattering detection (ELSD), charged aerosol detection (CAD), electrospray mass spectrometry (ESI-MS), and UV detection. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Total milk fat extraction and quantification of polar and neutral lipids of cow, goat, and ewe milk by using a pressurized liquid system and chromatographic techniques.

    Science.gov (United States)

    Castro-Gómez, M P; Rodriguez-Alcalá, L M; Calvo, M V; Romero, J; Mendiola, J A; Ibañez, E; Fontecha, J

    2014-11-01

    Although milk polar lipids such as phospholipids and sphingolipids located in the milk fat globule membrane constitute 0.1 to 1% of the total milk fat, those lipid fractions are gaining increasing interest because of their potential beneficial effects on human health and technological properties. In this context, the accurate quantification of the milk polar lipids is crucial for comparison of different milk species, products, or dairy treatments. Although the official International Organization for Standardization-International Dairy Federation method for milk lipid extraction gives satisfactory results for neutral lipids, it has important disadvantages in terms of polar lipid losses. Other methods using mixtures of solvents such as chloroform:methanol are highly efficient for extracting polar lipids but are also associated with low sample throughput, long time, and large solvent consumption. As an alternative, we have optimized the milk fat extraction yield by using a pressurized liquid extraction (PLE) method at different temperatures and times in comparison with those traditional lipid extraction procedures using 2:1 chloroform:methanol as a mixture of solvents. Comparison of classical extraction methods with the developed PLE procedure were carried out using raw whole milk from different species (cows, ewes, and goats) and considering fat yield, fatty acid methyl ester composition, triacylglyceride species, cholesterol content, and lipid class compositions, with special attention to polar lipids such as phospholipids and sphingolipids. The developed PLE procedure was validated for milk fat extraction and the results show that this method performs a complete or close to complete extraction of all lipid classes and in less time than the official and Folch methods. In conclusion, the PLE method optimized in this study could be an alternative to carry out milk fat extraction as a routine method. Copyright © 2014 American Dairy Science Association. Published by

  15. Fossilized intact polar lipids of photosynthetic organisms in ancient subsurface sediments

    Science.gov (United States)

    Bauersachs, T.; Schouten, S.; Hopmans, E. C.; Sinninghe Damsté, J. S.

    2009-12-01

    In recent years, the idea of a rich microbial biosphere in the marine sea floor has been widely accepted. This so-called “deep biosphere” is estimated to contain ca. 50 % of Earth’s total prokaryotic biomass with the overall order of magnitude of microbial cells in the sea floor being the same as the biomass of all surface plant life (Whitman et al. 1998). Evidence for the existence of a deep biosphere comes, among others, from the analysis of intact polar lipids (IPLs). This approach presumes that IPLs almost instantaneously lose their polar head group after cell death and thus do not preserve on geological timescales. Consequently, IPLs in the subsurface should derive from in situ production and hence indicate the presence of living prokaryotic cells. For example, in various oceanic subsurface sediments archaeal IPLs have been found, suggesting that Archaea constitute a major fraction of the deep biosphere biomass (Lipp et al. 2008). In this study, we found IPLs of heterocystous cyanobacteria in a number of ancient and deeply buried sediments. Heterocystous cyanobacteria are strictly photoautotrophic organisms that are a common constituent of the phytoplankton community in many freshwater and brackish environments but are also encountered in the marine realm as endosymbionts of diatom species. Under nitrogen-depleted conditions, these organisms carry out nitrogen fixation in specialized cells, known as heterocysts. These cells contain a suite of heterocyst glycolipids (HGs) that have not been identified in any other organism and are thus unique biological markers for nitrogen-fixing heterocystous cyanobacteria. Using high performance liquid chromatography coupled to electrospray ionisation tandem mass spectrometry (HPLC/ESI-MS/MS), we detected HGs in Pleistocene and Pliocene Mediterranean sapropels buried up to 60 m below the seafloor. In addition, these HGs were also found in lacustrine deposits of the Oligocene Lake Enspel (35 Ma), the Eocene Lake Messel

  16. The influence of non polar and polar molecules in mouse motile cells membranes and pure lipid bilayers.

    Directory of Open Access Journals (Sweden)

    Francisco J Sierra-Valdez

    Full Text Available We report an experimental study of mouse sperm motility that shows chief aspects characteristic of neurons: the anesthetic (produced by tetracaine and excitatory (produced by either caffeine or calcium effects and their antagonic action. While tetracaine inhibits sperm motility and caffeine has an excitatory action, the combination of these two substances balance the effects, producing a motility quite similar to that of control cells. We also study the effects of these agents (anesthetic and excitatory on the melting points of pure lipid liposomes constituted by 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC and dipalmitoyl phosphatidic acid (DPPA. Tetracaine induces a large fluidization of the membrane, shifting the liposomes melting transition temperature to much lower values. The effect of caffeine is null, but its addition to tetracaine-doped liposomes greatly screen the fluidization effect. A high calcium concentration stiffens pure lipid membranes and strongly reduces the effect of tetracaine. Molecular Dynamics Simulations are performed to further understand our experimental findings at the molecular level. We find a strong correlation between the effect of antagonic molecules that could explain how the mechanical properties suitable for normal cell functioning are affected and recovered.

  17. Fatty acid composition of polar and neutral meat lipids of goats browsing in native pasture of Brazilian Semiarid.

    Science.gov (United States)

    Fonteles, Natália L O; Alves, Susana P; Madruga, Marta Suely; Queiroga, Rita R E; Andrade, Albericio P; Silva, Divan S; Leal, Amanda P; Bessa, Rui J B; Medeiros, Ariosvaldo N

    2018-05-01

    Thirty six male goats grazing Caatinga native pasture were randomly assigned to 4 concentrate supplementation levels (0, 5, 10 and 15g/kg of body weight) and slaughtered after 120days. Longissimus muscle meat lipids were extracted and fractionated into neutral (NL) and polar (PL) lipids. Supplementation of grazing goats increased linearly (Pmeat) and NL (0.3 to 1% of meat) but decreased linearly (P=0.044) the PL (0.66 to 0.50% of meat). On NL, supplementation increased linearly (P=0.047) the proportion of c9-18:1 (31 to 40% of FA) with supplementation. On PL, supplementation reduced linearly (Pmeat FA, supplementation led to an increase of the saturated and monounsaturated FA contents and a decrease of the long chain n-6 and n-3 PUFA contents. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Structure of Lipid Nanoparticles Containing siRNA or mRNA by Dynamic Nuclear Polarization-Enhanced NMR Spectroscopy.

    Science.gov (United States)

    Viger-Gravel, Jasmine; Schantz, Anna; Pinon, Arthur C; Rossini, Aaron J; Schantz, Staffan; Emsley, Lyndon

    2018-02-22

    Here, we show how dynamic nuclear polarization (DNP) NMR spectroscopy experiments permit the atomic level structural characterization of loaded and empty lipid nanoparticles (LNPs). The LNPs used here were synthesized by the microfluidic mixing technique and are composed of ionizable cationic lipid (DLin-MC3-DMA), a phospholipid (distearoylphosphatidylcholine, DSPC), cholesterol, and poly(ethylene glycol) (PEG) (dimyristoyl phosphatidyl ethanolamine (DMPE)-PEG 2000), as well as encapsulated cargoes that are either phosphorothioated siRNA (50 or 100%) or mRNA. We show that LNPs form physically stable complexes with bioactive drug siRNA for a period of 94 days. Relayed DNP experiments are performed to study 1 H- 1 H spin diffusion and to determine the spatial location of the various components of the LNP by studying the average enhancement factors as a function of polarization time. We observe a striking feature of LNPs in the presence and in the absence of encapsulating siRNA or mRNA by comparing our experimental results to numerical spin-diffusion modeling. We observe that LNPs form a layered structure, and we detect that DSPC and DMPE-PEG 2000 lipids form a surface rich layer in the presence (or absence) of the cargoes and that the cholesterol and ionizable cationic lipid are embedded in the core. Furthermore, relayed DNP 31 P solid-state NMR experiments allow the location of the cargo encapsulated in the LNPs to be determined. On the basis of the results, we propose a new structural model for the LNPs that features a homogeneous core with a tendency for layering of DSPC and DMPE-PEG at the surface.

  19. Lateral mobility of plasma membrane lipids in a molluscan egg: Evidence for an animal/vegetal polarity

    OpenAIRE

    Laat, S.W. de; Speksnijder, J.E.; Dohmen, M.R.; Zoelen, E. van; Tertoolen, L.G.J.; Bluemink, J.G.

    1984-01-01

    The lateral diffusion of the lipid analog C₁₄-diI (3', 3'-dihexadecylindocarbocyanine iodide) was measured in the plasma membrane of early embryos of the mollusc Nassarius reticulatus using the FPR-(Fluorescence Photobleaching Recovery) method. At almost all stages measured (from fertilized egg up to 8-cell stage) the diffusion coefficient (D) of the mobile fraction (MF) of C₁₄-diI is significantly higher in the plasma membrane of the polar lobe as compared to the plasma membrane of the anima...

  20. The efficacy of compounds with different polarities as antioxidant in emulsions with omega-3 lipids

    DEFF Research Database (Denmark)

    Sørensen, Ann-Dorit Moltke; Nielsen, Nina Skall; Decker, Eric A.

    2011-01-01

    According to the so-called polar paradox hypothesis, the efficacy of an antioxidant in emulsions is highly affected by its polarity and thereby location in the different phases. However, other factors also affect the efficacy of antioxidants in multiphase systems. The aim of this study was to eva...

  1. pH sensing by lipids in membranes: The fundamentals of pH-driven migration, polarization and deformations of lipid bilayer assemblies.

    Science.gov (United States)

    Angelova, Miglena I; Bitbol, Anne-Florence; Seigneuret, Michel; Staneva, Galya; Kodama, Atsuji; Sakuma, Yuka; Kawakatsu, Toshihiro; Imai, Masayuki; Puff, Nicolas

    2018-03-06

    Most biological molecules contain acido-basic groups that modulate their structure and interactions. A consequence is that pH gradients, local heterogeneities and dynamic variations are used by cells and organisms to drive or regulate specific biological functions including energetic metabolism, vesicular traffic, migration and spatial patterning of tissues in development. While the direct or regulatory role of pH in protein function is well documented, the role of hydrogen and hydroxyl ions in modulating the properties of lipid assemblies such as bilayer membranes is only beginning to be understood. Here, we review approaches using artificial lipid vesicles that have been instrumental in providing an understanding of the influence of pH gradients and local variations on membrane vectorial motional processes: migration, membrane curvature effects promoting global or local deformations, crowding generation by segregative polarization processes. In the case of pH induced local deformations, an extensive theoretical framework is given and an application to a specific biological issue, namely the structure and stability of mitochondrial cristae, is described. This article is part of a Special Issue entitled: Emergence of Complex Behavior in Biomembranes edited by Marjorie Longo. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. Comparative plasma lipidome between human and cynomolgus monkey: are plasma polar lipids good biomarkers for diabetic monkeys?

    Directory of Open Access Journals (Sweden)

    Guanghou Shui

    Full Text Available BACKGROUND: Non-human primates (NHP are now being considered as models for investigating human metabolic diseases including diabetes. Analyses of cholesterol and triglycerides in plasma derived from NHPs can easily be achieved using methods employed in humans. Information pertaining to other lipid species in monkey plasma, however, is lacking and requires comprehensive experimental analysis. METHODOLOGIES/PRINCIPAL FINDINGS: We examined the plasma lipidome from 16 cynomolgus monkey, Macaca fascicularis, using liquid chromatography coupled with mass spectrometry (LC/MS. We established novel analytical approaches, which are based on a simple gradient elution, to quantify polar lipids in plasma including (i glycerophospholipids (phosphatidylcholine, PC; phosphatidylethanolamine, PE; phosphatidylinositol, PI; phosphatidylglycerol, PG; phosphatidylserine, PS; phosphatidic acid, PA; (ii sphingolipids (sphingomyelin, SM; ceramide, Cer; Glucocyl-ceramide, GluCer; ganglioside mannoside 3, GM3. Lipidomic analysis had revealed that the plasma of human and cynomolgus monkey were of similar compositions, with PC, SM, PE, LPC and PI constituting the major polar lipid species present. Human plasma contained significantly higher levels of plasmalogen PE species (p<0.005 and plasmalogen PC species (p<0.0005, while cynomolgus monkey had higher levels of polyunsaturated fatty acyls (PUFA in PC, PE, PS and PI. Notably, cynomolgus monkey had significantly lower levels of glycosphingolipids, including GluCer (p<0.0005 and GM(3 (p<0.0005, but higher level of Cer (p<0.0005 in plasma than human. We next investigated the biochemical alterations in blood lipids of 8 naturally occurring diabetic cynomolgus monkeys when compared with 8 healthy controls. CONCLUSIONS: For the first time, we demonstrated that the plasma of human and cynomolgus monkey were of similar compositions, but contained different mol distribution of individual molecular species. Diabetic monkeys

  3. Effect of slaughter age and feeding system on the neutral and polar lipid composition of horse meat.

    Science.gov (United States)

    Belaunzaran, X; Lavín, P; Mantecón, A R; Kramer, J K G; Aldai, N

    2018-02-01

    This study was undertaken to provide a thorough analysis of the neutral lipid (NL) and polar lipid (PL) fractions of horse meat that included the content and distribution of acyl and alkenyl moieties in foals under different rearing conditions. Two groups of crossbred horses were studied; the first group was selected from suckling foals produced under grazing conditions and slaughtered at 4 months of age (n=8), and the second group was selected from concentrate-finished foals and slaughtered at 12 months of age (n=7). There were significant differences related to the age and feeding practices of foals which affected the intramuscular (IM) fat content and the fatty acid (FA) composition of NL and PL fractions. Samples from suckling foals were leaner and provided the highest content of methylation products from the plasmalogenic lipids, and total and n-3 polyunsaturated fatty acid (PUFA). By contrast, the meat from concentrate-finished foals had a higher IM fat level resulting in a greater accumulation of 16:0 and total monounsaturated FAs in the NL fraction, whereas the muscle PL fraction retained a similar FA composition between both groups. Linolenic acid was preferentially deposited in the NL fraction, but linoleic acid and the long-chain n-3 and n-6 PUFAs were incorporated into the PL fraction where they served as cell membrane constituents and in eicosanoid formation.

  4. Sorptive capacities of lipids determined by passive dosing of non-polar organic chemicals

    DEFF Research Database (Denmark)

    Jahnke, Annika; Kierkegaard, Amelie; Bolinius, Damien

    VMS), chlorobenzenes and polychlorinated biphenyls via a common headspace over an olive oil donor phase to transfer the same chemical activity into the samples; iii) sampling of EOM and olive oil controls at different time points; iv) purge-and-trap extraction of the model chemicals onto ENV+ SPE cartridges, elution...... and GC/MS analysis; v) characterization of the lipid composition in all samples via NMR. Our experiments demonstrate that the sorptive capacities of the EOM samples do not differ significantly from the olive oil controls if the EOM consists of neutral lipids only. However, the EOM samples show small...

  5. Lateral mobility of plasma membrane lipids in Xenopus eggs: Regional differences related to animal/vegetal polarity

    NARCIS (Netherlands)

    Laat, S.W. de; Bluemink, J.G.; Dictus, W.J.A.G.; Zoelen, E.J.J. van; Tetteroo, P.A.T.; Tertoolen, L.G.J.

    1984-01-01

    Regional differences in the lateral mobility properties of plasma membrane lipids were studied in unfertilized and fertilized Xenopus eggs by fluorescence photobleaching recovery (FPR) measurements. Out of a variety of commonly used lipid probes only the aminofluorescein- -1abelled fatty

  6. The Reorientation of T-Cell Polarity and Inhibition of Immunological Synapse Formation by CD46 Involves Its Recruitment to Lipid Rafts

    Directory of Open Access Journals (Sweden)

    Mandy J. Ludford-Menting

    2011-01-01

    Full Text Available Many infectious agents utilize CD46 for infection of human cells, and therapeutic applications of CD46-binding viruses are now being explored. Besides mediating internalization to enable infection, binding to CD46 can directly alter immune function. In particular, ligation of CD46 by antibodies or by measles virus can prevent activation of T cells by altering T-cell polarity and consequently preventing the formation of an immunological synapse. Here, we define a mechanism by which CD46 reorients T-cell polarity to prevent T-cell receptor signaling in response to antigen presentation. We show that CD46 associates with lipid rafts upon ligation, and that this reduces recruitment of both lipid rafts and the microtubule organizing centre to the site of receptor cross-linking. These data combined indicate that polarization of T cells towards the site of CD46 ligation prevents formation of an immunological synapse, and this is associated with the ability of CD46 to recruit lipid rafts away from the site of TCR ligation.

  7. Combined thin layer chromatography and gas chromatography with mass spectrometric analysis of lipid classes and fatty acids in malnourished polar bears (Ursus maritimus) which swam to Iceland.

    Science.gov (United States)

    Eibler, Dorothee; Krüger, Sabine; Skírnisson, Karl; Vetter, Walter

    2017-03-01

    Between 2008 and 2011, four polar bears (Ursus maritimus) from the Greenland population swam and/or drifted on ice to Iceland where they arrived in very poor body condition. Body fat resources in these animals were only between 0% and 10% of the body weight (usually 25%). Here we studied the lipid composition in different tissues (adipose tissue if available, liver, kidney and muscle). Lipid classes were determined by thin layer chromatography (TLC) and on-column gas chromatography with mass spectrometry (GC/MS). The fatty acid pattern of total lipids and free fatty acids was analyzed by GC/MS in selected ion monitoring (SIM) mode. Additionally, cholesteryl esters and native fatty acid methyl esters, initially detected as zones in thin layer chromatograms, were enriched by solid phase extraction and quantified by GC/MS. The ratio of free fatty acids to native fatty acid methyl esters could be correlated with the remained body lipids in the polar bears and thus may also serve as a marker for other starving animals or even for humans. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Lateral mobility of plasma membrane lipids in Xenopus eggs: regional differences related to animal/vegetal polarity become extreme upon fertilization.

    Science.gov (United States)

    Dictus, W J; van Zoelen, E J; Tetteroo, P A; Tertoolen, L G; de Laat, S W; Bluemink, J G

    1984-01-01

    Regional differences in the lateral mobility properties of plasma membrane lipids have been studied in unfertilized and fertilized Xenopus eggs by fluorescence photobleaching recovery (FPR) measurements. Out of a variety of commonly used lipid probes only the aminofluorescein-labeled fatty acids HEDAF (5-(N-hexadecanoyl)-aminofluorescein) and TEDAF (5-(N-tetradecanoyl)-aminofluorescein) appear to partition into the plasma membrane. Under all experimental conditions used these molecules show partial recovery upon photobleaching indicating the existence of lipidic microdomains. In the unfertilized egg the mobile fraction of plasma membrane lipids (approximately 50%) has a fivefold smaller lateral diffusion coefficient (D = 1.5 X 10(-8) cm2/sec) in the animal than in the vegetal plasma membrane (D = 7.6 X 10(-8) cm2/sec). This demonstrates the presence of an animal/vegetal polarity within the Xenopus egg plasma membrane. Upon fertilization this polarity is strongly (greater than 100X) enhanced leading to the formation of two distinct macrodomains within the plasma membrane. At the animal side of the egg lipids are completely immobilized on the time scale of FPR measurements (D less than 10(-10) cm2/sec), whereas at the vegetal side D is only slightly reduced (D = 4.4 X 10(-8) cm2/sec). The immobilization of animal plasma membrane lipids, which could play a role in the polyspermy block, probably arises by the fusion of cortical granules which are more numerous here. The transition between the animal and the vegetal domain is sharp and coincides with the boundary between the presumptive ecto- and endoderm. The role of regional differences in the plasma membrane is discussed in relation to cell diversification in early development.

  9. Profiling of Polar Lipids in Marine Oleaginous Diatom Fistulifera solaris JPCC DA0580: Prediction of the Potential Mechanism for Eicosapentaenoic Acid-Incorporation into Triacylglycerol

    Directory of Open Access Journals (Sweden)

    Yue Liang

    2014-05-01

    Full Text Available The marine oleaginous diatom Fistulifera solaris JPCC DA0580 is a candidate for biodiesel production because of its high lipid productivity. However, the substantial eicosapentaenoic acid (EPA content in this strain would affect the biodiesel quality. On the other hand, EPA is also known as the essential health supplement for humans. EPAs are mainly incorporated into glycerolipids in the microalgal cell instead of the presence as free fatty acids. Therefore, the understanding of the EPA biosynthesis including the incorporation of the EPA into glycerolipids especially triacylglycerol (TAG is fundamental for regulating EPA content for different purposes. In this study, in order to identify the biosynthesis pathway for the EPA-containing TAG species, a lipidomic characterization of the EPA-enriched polar lipids was performed by using direct infusion electrospray ionization (ESI-Q-TRAP-MS and MS/MS analyses. The determination of the fatty acid positional distribution showed that the sn-2 position of all the chloroplast lipids and part of phosphatidylcholine (PC species was occupied by C16 fatty acids. This result suggested the critical role of the chloroplast on the lipid synthesis in F. solaris. Furthermore, the exclusive presence of C18 fatty acids in PC highly indicated the biosynthesis of EPA on PC. Finally, the PC-based acyl-editing and head group exchange processes were proposed to be essential for the incorporation of EPA into TAG and chloroplast lipids.

  10. Comparing identified and statistically significant lipids and polar metabolites in 15-year old serum and dried blood spot samples for longitudinal studies: Comparing lipids and metabolites in serum and DBS samples

    Energy Technology Data Exchange (ETDEWEB)

    Kyle, Jennifer E. [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland WA USA; Casey, Cameron P. [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland WA USA; Stratton, Kelly G. [National Security Directorate, Pacific Northwest National Laboratory, Richland WA USA; Zink, Erika M. [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland WA USA; Kim, Young-Mo [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland WA USA; Zheng, Xueyun [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland WA USA; Monroe, Matthew E. [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland WA USA; Weitz, Karl K. [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland WA USA; Bloodsworth, Kent J. [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland WA USA; Orton, Daniel J. [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland WA USA; Ibrahim, Yehia M. [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland WA USA; Moore, Ronald J. [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland WA USA; Lee, Christine G. [Department of Medicine, Bone and Mineral Unit, Oregon Health and Science University, Portland OR USA; Research Service, Portland Veterans Affairs Medical Center, Portland OR USA; Pedersen, Catherine [Department of Medicine, Bone and Mineral Unit, Oregon Health and Science University, Portland OR USA; Orwoll, Eric [Department of Medicine, Bone and Mineral Unit, Oregon Health and Science University, Portland OR USA; Smith, Richard D. [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland WA USA; Burnum-Johnson, Kristin E. [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland WA USA; Baker, Erin S. [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland WA USA

    2017-02-05

    The use of dried blood spots (DBS) has many advantages over traditional plasma and serum samples such as smaller blood volume required, storage at room temperature, and ability for sampling in remote locations. However, understanding the robustness of different analytes in DBS samples is essential, especially in older samples collected for longitudinal studies. Here we analyzed DBS samples collected in 2000-2001 and stored at room temperature and compared them to matched serum samples stored at -80°C to determine if they could be effectively used as specific time points in a longitudinal study following metabolic disease. Four hundred small molecules were identified in both the serum and DBS samples using gas chromatograph-mass spectrometry (GC-MS), liquid chromatography-MS (LC-MS) and LC-ion mobility spectrometry-MS (LC-IMS-MS). The identified polar metabolites overlapped well between the sample types, though only one statistically significant polar metabolite in a case-control study was conserved, indicating degradation occurs in the DBS samples affecting quantitation. Differences in the lipid identifications indicated that some oxidation occurs in the DBS samples. However, thirty-six statistically significant lipids correlated in both sample types indicating that lipid quantitation was more stable across the sample types.

  11. Lipid somersaults

    DEFF Research Database (Denmark)

    Günther-Pomorski, Thomas; Menon, Anant K.

    2016-01-01

    Membrane lipids diffuse rapidly in the plane of the membrane but their ability to flip spontaneously across a membrane bilayer is hampered by a significant energy barrier. Thus spontaneous flip-flop of polar lipids across membranes is very slow, even though it must occur rapidly to support diverse...... aspects of cellular life. Here we discuss the mechanisms by which rapid flip-flop occurs, and what role lipid flipping plays in membrane homeostasis and cell growth. We focus on conceptual aspects, highlighting mechanistic insights from biochemical and in silico experiments, and the recent, ground......-breaking identification of a number of lipid scramblases....

  12. Levels of Arabidopsis thaliana leaf phosphatidic acids, phosphatidylserines, and most trienoate-containing polar lipid molecular species increase during the dark period of the diurnal cycle

    Directory of Open Access Journals (Sweden)

    Sara eMaatta

    2012-03-01

    Full Text Available Previous work has demonstrated that plant leaf polar lipid fatty acid composition varies during the diurnal (dark-light cycle. Fatty acid synthesis occurs primarily during the light, but fatty acid desaturation continues in the absence of light, resulting in polyunsaturated fatty acids reaching their highest levels toward the end of the dark period. In this work, Arabidopsis thaliana were grown at constant (21°C temperature with 12-h light and 12-h dark periods. Collision induced dissociation time-of-flight mass spectrometry demonstrated that 16:3 and 18:3 fatty acid content in membrane lipids of leaves are higher at the end of the dark than at the end of the light period, while 16:1, 16:2, 18:0, and 18:1 content are higher at the end of the light period. Lipid profiling of membrane galactolipids, phospholipids, and lysophospholipids by electrospray ionization triple quadrupole mass spectrometry indicated that the monogalactosyldiacylglycerol, phosphatidylglycerol, and phosphatidylcholine classes include molecular species whose levels are highest at end of the light period and others that are highest at the end of the dark period. The levels of phosphatidic acid and phosphatidylserine classes were higher at the end of the dark period, and molecular species within these classes either followed the class pattern or were not significantly changed in the diurnal cycle. Phospholipase D (PLD is a family of enzymes that hydrolyzes phospholipids to produce phosphatidic acid. Analysis of several PLD mutant lines suggests that PLDζ2 and possibly PLDα1 may contribute to diurnal cycling of phosphatidic acid. The polar lipid compositional changes are considered in relation to recent data that demonstrate phosphatidylcholine acyl editing.

  13. Soybean polar lipids differently impact adipose tissue inflammation and the endotoxin transporters LBP and sCD14 in flaxseed vs. palm oil-rich diets.

    Science.gov (United States)

    Lecomte, Manon; Couëdelo, Leslie; Meugnier, Emmanuelle; Loizon, Emmanuelle; Plaisancié, Pascale; Durand, Annie; Géloën, Alain; Joffre, Florent; Vaysse, Carole; Michalski, Marie-Caroline; Laugerette, Fabienne

    2017-05-01

    Obesity and type 2 diabetes are nutritional pathologies, characterized by a subclinical inflammatory state. Endotoxins are now well recognized as an important factor implicated in the onset and maintain of this inflammatory state during fat digestion in high-fat diet. As a preventive strategy, lipid formulation could be optimized to limit these phenomena, notably regarding fatty acid profile and PL emulsifier content. Little is known about soybean polar lipid (SPL) consumption associated to oils rich in saturated FA vs. anti-inflammatory omega-3 FA such as α-linolenic acid on inflammation and metabolic endotoxemia. We then investigated in mice the effect of different synthetic diets enriched with two different oils, palm oil or flaxseed oil and containing or devoid of SPL on adipose tissue inflammation and endotoxin receptors. In both groups containing SPL, adipose tissue (WAT) increased compared with groups devoid of SPL and an induction of MCP-1 and LBP was observed in WAT. However, only the high-fat diet in which flaxseed oil was associated with SPL resulted in both higher WAT inflammation and higher circulating sCD14 in plasma. In conclusion, we have demonstrated that LPS transporters LBP and sCD14 and adipose tissue inflammation can be modulated by SPL in high fat diets differing in oil composition. Notably high-flaxseed oil diet exerts a beneficial metabolic impact, however blunted by PL addition. Our study suggests that nutritional strategies can be envisaged by optimizing dietary lipid sources in manufactured products, including fats/oils and polar lipid emulsifiers, in order to limit the inflammatory impact of palatable foods. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. The song of lipids and proteins: dynamic lipid-protein interfaces in the regulation of plant cell polarity at different scales

    Czech Academy of Sciences Publication Activity Database

    Sekereš, J.; Pleskot, Roman; Pejchar, P.; Žárský, V.; Potocký, M.

    2015-01-01

    Roč. 66, č. 6 (2015), s. 1587-1598 ISSN 0022-0957 Institutional support: RVO:61388963 Keywords : cell polarity * endocytosis * exocytosis * membrane trafficking * membrane domain Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 5.677, year: 2015

  15. The song of lipids and proteins: dynamic lipid-protein interfaces in the regulation of plant cell polarity at different scales

    Czech Academy of Sciences Publication Activity Database

    Sekereš, Juraj; Pleskot, Roman; Pejchar, Přemysl; Žárský, Viktor; Potocký, Martin

    2015-01-01

    Roč. 66, č. 6 (2015), s. 1587-1598 ISSN 0022-0957 R&D Projects: GA ČR GA13-19073S Grant - others:GA MŠk(CZ) LO1417 Institutional support: RVO:61389030 Keywords : Cell polarity * endocytosis * exocytosis Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.677, year: 2015

  16. BALLISTIC RESISTANT ARTICLES COMPRISING TAPES

    NARCIS (Netherlands)

    VAN DER EEM, JORIS; HARINGS, JULES; JANSE, GERARDUS; TJADEN, HENDRIK

    2015-01-01

    The invention pertains to a ballistic-resistant moulded article comprising a compressed stack of sheets comprising reinforcing tapes having a tensile strength of at least 1.0 GPa, a tensile modulus of at least 40 GPa, and a tensile energy-to-break of at least 15 J/g, the direction of the tapes

  17. Lipid composition of phytoplankton from the Barents Sea and environmental influences on the distribution pattern of carbon among photosynthetic end products

    OpenAIRE

    Henderson, R. James; Olsen, Rolf E.; Eilertsen, Hans C.

    1991-01-01

    The colonial algae Phaeocystis pouchetii and Dinobryon pellucidum dominated the phytoplankton crop at three stations in the Polar Front area of the Barents Sea. Lipid extracted from the seawater containing the phytoplankton was dominated by neutral lipid classes, particularly triacylglycerols, and phospholipids were more abundant than galactolipids at all stations. Polyunsaturated fatty acids comprised between 15 and 26% of fatty acids of total lipid. Of the carbon assimilated into lipid over...

  18. Lateral mobility of plasma membrane lipids in Xenopus eggs: Regional differences related to animal/vegetal polarity

    OpenAIRE

    Laat, S.W. de; Bluemink, J.G.; Dictus, W.J.A.G.; Zoelen, E.J.J. van; Tetteroo, P.A.T.; Tertoolen, L.G.J.

    1984-01-01

    Regional differences in the lateral mobility properties of plasma membrane lipids were studied in unfertilized and fertilized Xenopus eggs by fluorescence photobleaching recovery (FPR) measurements. Out of a variety of commonly used lipid probes only the aminofluorescein- -1abelled fatty acids HEDAF (5-(N-hexadecanoyl)- aminofluorescein) and TEDAF (5-(N-tetradecanoyl)-aminofluorescein) appear to distribute itself in the plasma membrane. Under all experimental conditions used these molecules s...

  19. Lateral mobility of plasma membrane lipids in a molluscan egg: Evidence for an animal/vegetal polarity

    NARCIS (Netherlands)

    Laat, S.W. de; Speksnijder, J.E.; Dohmen, M.R.; Zoelen, E. van; Tertoolen, L.G.J.; Bluemink, J.G.

    1984-01-01

    The lateral diffusion of the lipid analog C₁₄-diI (3', 3'-dihexadecylindocarbocyanine iodide) was measured in the plasma membrane of early embryos of the mollusc Nassarius reticulatus using the FPR-(Fluorescence Photobleaching Recovery) method. At almost all stages measured (from

  20. Ionic liquids comprising heteraromatic anions

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, William F.; Brennecke, Joan F.; Maginn, Edward J.; Mindrup, Elaine; Gurkan, Burcu; Price, Erica; Goodrich, Brett

    2018-04-24

    Some embodiments described herein relate to ionic liquids comprising an anion of a heteraromatic compound such as optionally substituted pyrrolide, optionally substituted pyrazolide, optionally substituted indolide, optionally substituted phospholide, or optionally substituted imidazolide. Methods and devices for gas separation or gas absorption related to these ionic liquids are also described herein.

  1. The dinoflagellate Lingulodinium polyedrum responds to N depletion by a polarized deposition of starch and lipid bodies.

    Directory of Open Access Journals (Sweden)

    Steve Dagenais Bellefeuille

    Full Text Available Dinoflagellates are important contributors to the marine phytoplankton and global carbon fixation, but are also infamous for their ability to form the spectacular harmful algal blooms called red tides. While blooms are often associated with high available nitrogen, there are instances where they are observed in oligotrophic environments. In order to maintain their massive population in conditions of nitrogen limitation, dinoflagellates must have evolved efficient adaptive mechanisms. Here we report the physiological responses to nitrogen deprivation in Lingulodinium polyedrum. We find that this species reacts to nitrogen stress, as do most plants and microalgae, by stopping cell growth and diminishing levels of internal nitrogen, in particular in the form of protein and chlorophyll. Photosynthesis is maintained at high levels for roughly a week following nitrate depletion, resulting in accumulated photosynthetic products in the form of starch. During the second week, photosynthesis rates decrease due to a reduction in the number of chloroplasts and the accumulation of neutral lipid droplets. Surprisingly, the starch granules and lipid droplets are seen to accumulate at opposite poles of the cell. Lastly, we observe that cells acclimated to nitrogen-depleted conditions resume normal growth after addition of inorganic nitrogen, but are able to maintain high cell densities far longer than cells grown continuously in nitrogen-replete conditions.

  2. Polar Quassinoids in Standardized Eurycoma longifolia Extract Formulated into a Lipid-Based Solid Dispersion to Improve Rat Sperm Count.

    Science.gov (United States)

    Ma, Hai-Qiu; Ebrahimi, Forough; Low, Bin-Seng; Khan, Nurzalina Abdul Karim; Chan, Kit-Lam

    2017-12-01

    Eurycoma longifolia Jack is popularly sought in Southeast Asian countries for traditional remedies to improve sexual performance and fertility. 13α(21)-Epoxyeurycomanone and eurycomanone, two major quassinoids in a root extract (TAF2) were reported to improve rat spermatogenesis and fertility. Unfortunately, these quassinoids possess low bioavailability because of high aqueous solubility and low lipid membrane permeability. Often, other possible barriers may be P-glycoprotein (P-gp) efflux in the gut and presystemic hepatic metabolism. The present study attempted to solve these problems by formulating a lipid-based solid dispersion (TAF2-SD) of optimized mixture of TAF2 and emulsifiers, which was then orally administered to rats prior to sperm count analysis. The TAF2-SD-treated rats showed significantly twofold (p < 0.001) and fourfold (p < 0.001) higher sperm count than did TAF2-treated and vehicle-treated (control) rats, respectively. The study also demonstrated no significant in vitro ileal absorption changes of the quassinoids by P-gp efflux inhibitors and concentration change or secondary metabolite formation upon in vitro incubation with rat liver homogenates, suggesting that P-gp-mediated efflux and presystemic metabolism were not limiting their bioavailability. Further study on orally TAF2-treated rats confirmed that the area under the curve and bioavailability curve of each quassinoid in the absence and presence of ketoconazole were unchanged. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  3. Versatile lipid profiling by liquid chromatography–high resolution mass spectrometry using all ion fragmentation and polarity switching. Preliminary application for serum samples phenotyping related to canine mammary cancer

    Energy Technology Data Exchange (ETDEWEB)

    Gallart-Ayala, H., E-mail: laberca@oniris-nantes.fr [LUNAM, Ecole Nationale Vétérinaire, Agroalimentaire et de l’Alimentation Nantes Atlantique (Oniris), USC 1329 INRA Laboratoire d’Etude des résidus et Contaminants dans les Aliments (LABERCA), Site de la Chantrerie – CS50707, 44307 Nantes cedex 3 (France); Courant, F.; Severe, S.; Antignac, J.-P. [LUNAM, Ecole Nationale Vétérinaire, Agroalimentaire et de l’Alimentation Nantes Atlantique (Oniris), USC 1329 INRA Laboratoire d’Etude des résidus et Contaminants dans les Aliments (LABERCA), Site de la Chantrerie – CS50707, 44307 Nantes cedex 3 (France); Morio, F.; Abadie, J. [LUNAM, Ecole Nationale Vétérinaire, Agroalimentaire et de l’Alimentation Nantes Atlantique (Oniris), Cancers Animaux, Modèles pour la Recherche en Oncologie Comparée (AMaROC), Site de la Chantrerie–CS50707, 44307 Nantes cedex 3 (France); Le Bizec, B. [LUNAM, Ecole Nationale Vétérinaire, Agroalimentaire et de l’Alimentation Nantes Atlantique (Oniris), USC 1329 INRA Laboratoire d’Etude des résidus et Contaminants dans les Aliments (LABERCA), Site de la Chantrerie – CS50707, 44307 Nantes cedex 3 (France)

    2013-09-24

    Graphical abstract: -- Highlights: •Lipidomics, high resolution mass spectrometry, polarity switching, serum, canine mammary cancer. -- Abstract: Lipids represent an extended class of substances characterized by such high variety and complexity that makes their unified analyses by liquid chromatography coupled to either high resolution or tandem mass spectrometry (LC–HRMS or LC–MS/MS) a real challenge. In the present study, a new versatile methodology associating ultra high performance liquid chromatography coupled to high resolution tandem mass spectrometry (UHPLC–HRMS/MS) have been developed for a comprehensive analysis of lipids. The use of polarity switching and “all ion fragmentation” (AIF) have been two action levels particularly exploited to finally permit the detection and identification of a multi-class and multi-analyte extended range of lipids in a single run. For identification purposes, both higher energy collision dissociation (HCD) and in-source CID (collision induced dissociation) fragmentation were evaluated in order to obtain information about the precursor and product ions in the same spectra. This approach provides both class-specific and lipid-specific fragments, enhancing lipid identification. Finally, the developed method was applied for differential phenotyping of serum samples collected from pet dogs developing spontaneous malignant mammary tumors and health controls. A biological signature associated with the presence of cancer was then successfully revealed from this lipidome analysis, which required to be further investigated and confirmed at larger scale.

  4. Versatile lipid profiling by liquid chromatography–high resolution mass spectrometry using all ion fragmentation and polarity switching. Preliminary application for serum samples phenotyping related to canine mammary cancer

    International Nuclear Information System (INIS)

    Gallart-Ayala, H.; Courant, F.; Severe, S.; Antignac, J.-P.; Morio, F.; Abadie, J.; Le Bizec, B.

    2013-01-01

    Graphical abstract: -- Highlights: •Lipidomics, high resolution mass spectrometry, polarity switching, serum, canine mammary cancer. -- Abstract: Lipids represent an extended class of substances characterized by such high variety and complexity that makes their unified analyses by liquid chromatography coupled to either high resolution or tandem mass spectrometry (LC–HRMS or LC–MS/MS) a real challenge. In the present study, a new versatile methodology associating ultra high performance liquid chromatography coupled to high resolution tandem mass spectrometry (UHPLC–HRMS/MS) have been developed for a comprehensive analysis of lipids. The use of polarity switching and “all ion fragmentation” (AIF) have been two action levels particularly exploited to finally permit the detection and identification of a multi-class and multi-analyte extended range of lipids in a single run. For identification purposes, both higher energy collision dissociation (HCD) and in-source CID (collision induced dissociation) fragmentation were evaluated in order to obtain information about the precursor and product ions in the same spectra. This approach provides both class-specific and lipid-specific fragments, enhancing lipid identification. Finally, the developed method was applied for differential phenotyping of serum samples collected from pet dogs developing spontaneous malignant mammary tumors and health controls. A biological signature associated with the presence of cancer was then successfully revealed from this lipidome analysis, which required to be further investigated and confirmed at larger scale

  5. Determination of structural topology of a membrane protein in lipid bilayers using polarization optimized experiments (POE) for static and MAS solid state NMR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Mote, Kaustubh R. [University of Minnesota, Department of Chemistry (United States); Gopinath, T. [University of Minnesota, Department of Biochemistry, Molecular Biology and Biophysics (United States); Veglia, Gianluigi, E-mail: vegli001@umn.edu [University of Minnesota, Department of Chemistry (United States)

    2013-10-15

    The low sensitivity inherent to both the static and magic angle spinning techniques of solid-state NMR (ssNMR) spectroscopy has thus far limited the routine application of multidimensional experiments to determine the structure of membrane proteins in lipid bilayers. Here, we demonstrate the advantage of using a recently developed class of experiments, polarization optimized experiments, for both static and MAS spectroscopy to achieve higher sensitivity and substantial time-savings for 2D and 3D experiments. We used sarcolipin, a single pass membrane protein, reconstituted in oriented bicelles (for oriented ssNMR) and multilamellar vesicles (for MAS ssNMR) as a benchmark. The restraints derived by these experiments are then combined into a hybrid energy function to allow simultaneous determination of structure and topology. The resulting structural ensemble converged to a helical conformation with a backbone RMSD {approx}0.44 A, a tilt angle of 24 Degree-Sign {+-} 1 Degree-Sign , and an azimuthal angle of 55 Degree-Sign {+-} 6 Degree-Sign . This work represents a crucial first step toward obtaining high-resolution structures of large membrane proteins using combined multidimensional oriented solid-state NMR and magic angle spinning solid-state NMR.

  6. Versatile lipid profiling by liquid chromatography-high resolution mass spectrometry using all ion fragmentation and polarity switching. Preliminary application for serum samples phenotyping related to canine mammary cancer.

    Science.gov (United States)

    Gallart-Ayala, H; Courant, F; Severe, S; Antignac, J-P; Morio, F; Abadie, J; Le Bizec, B

    2013-09-24

    Lipids represent an extended class of substances characterized by such high variety and complexity that makes their unified analyses by liquid chromatography coupled to either high resolution or tandem mass spectrometry (LC-HRMS or LC-MS/MS) a real challenge. In the present study, a new versatile methodology associating ultra high performance liquid chromatography coupled to high resolution tandem mass spectrometry (UHPLC-HRMS/MS) have been developed for a comprehensive analysis of lipids. The use of polarity switching and "all ion fragmentation" (AIF) have been two action levels particularly exploited to finally permit the detection and identification of a multi-class and multi-analyte extended range of lipids in a single run. For identification purposes, both higher energy collision dissociation (HCD) and in-source CID (collision induced dissociation) fragmentation were evaluated in order to obtain information about the precursor and product ions in the same spectra. This approach provides both class-specific and lipid-specific fragments, enhancing lipid identification. Finally, the developed method was applied for differential phenotyping of serum samples collected from pet dogs developing spontaneous malignant mammary tumors and health controls. A biological signature associated with the presence of cancer was then successfully revealed from this lipidome analysis, which required to be further investigated and confirmed at larger scale. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Thermal emitter comprising near-zero permittivity materials

    Science.gov (United States)

    Luk, Ting S.; Campione, Salvatore; Sinclair, Michael B.

    2017-10-25

    A novel thermal source comprising a semiconductor hyperbolic metamaterial provides control of the emission spectrum and the angular emission pattern. These properties arise because of epsilon-near-zero conditions in the semiconductor hyperbolic metamaterial. In particular, the thermal emission is dominated by the epsilon-near-zero effect in the doped quantum wells composing the semiconductor hyperbolic metamaterial. Furthermore, different properties are observed for s and p polarizations, following the characteristics of the strong anisotropy of hyperbolic metamaterials.

  8. Lateral mobility of plasma membrane lipids in Xenopus eggs: Regional differences related to animal/vegetal polarity become extreme upon fertilization

    NARCIS (Netherlands)

    Bluemink, J.G.; Dictus, W.J.A.G.; Zoelen, E.J.J. van; Tetteroo, P.A.T.; Tertoolen, L.G.J.; Laat, S.W. de

    1984-01-01

    Regional differences in the lateral mobility properties of plasma membrane lipids have been studied in unfertilized and fertilizedxaqpus eggs by fluorescence photobleaching recovery (FPR) measurements. Out of a variety of commonly used lipid probes only the aminofluorescein-labeled fatty acids

  9. GAS SEPARATION MEMBRANES COMPRISING PERMEABILITY ENHANCING ADDITIVES

    NARCIS (Netherlands)

    Wessling, Matthias; Sterescu, D.M.; Stamatialis, Dimitrios

    2007-01-01

    The present invention relates to polymer compositions comprising a (co)polymer comprising (a) an arylene oxide moiety and (b) a dendritic (co)polymer, a hyperbranched (co)polymer or a mixture thereof, and the use of these polymer compositions as membrane materials for the separation of gases. The

  10. Cationic electrodepositable coating composition comprising lignin

    Science.gov (United States)

    Fenn, David; Bowman, Mark P; Zawacky, Steven R; Van Buskirk, Ellor J; Kamarchik, Peter

    2013-07-30

    A cationic electrodepositable coating composition is disclosed. The present invention in directed to a cationic electrodepositable coating composition comprising a lignin-containing cationic salt resin, that comprises (A) the reaction product of: lignin, an amine, and a carbonyl compound; (B) the reaction product of lignin, epichlorohydrin, and an amine; or (C) combinations thereof.

  11. Semiconductor device comprising a pn-heterojunction

    NARCIS (Netherlands)

    2007-01-01

    An electric device is disclosed comprising a pn-heterojunction ( 4 ) formed by a nanowire ( 3 ) of 111 -V semiconductor material and a semiconductor body ( 1 ) comprising a group IV semiconductor material. The nanowire ( 3 ) is positioned in direct contact with the surface ( 2 ) of the semiconductor

  12. Texture of lipid bilayer domains

    DEFF Research Database (Denmark)

    Jensen, Uffe Bernchou; Brewer, Jonathan R.; Midtiby, Henrik Skov

    2009-01-01

    We investigate the texture of gel (g) domains in binary lipid membranes composed of the phospholipids DPPC and DOPC. Lateral organization of lipid bilayer membranes is a topic of fundamental and biological importance. Whereas questions related to size and composition of fluid membrane domain...... are well studied, the possibility of texture in gel domains has so far not been examined. When using polarized light for two-photon excitation of the fluorescent lipid probe Laurdan, the emission intensity is highly sensitive to the angle between the polarization and the tilt orientation of lipid acyl...... chains. By imaging the intensity variations as a function of the polarization angle, we map the lateral variations of the lipid tilt within domains. Results reveal that gel domains are composed of subdomains with different lipid tilt directions. We have applied a Fourier decomposition method...

  13. Lateral mobility of plasma membrane lipids in Xenopus eggs: Regional differences related to animal/vegetal polarity become extreme upon fertilization

    OpenAIRE

    Bluemink, J.G.; Dictus, W.J.A.G.; Zoelen, E.J.J. van; Tetteroo, P.A.T.; Tertoolen, L.G.J.; Laat, S.W. de

    1984-01-01

    Regional differences in the lateral mobility properties of plasma membrane lipids have been studied in unfertilized and fertilizedxaqpus eggs by fluorescence photobleaching recovery (FPR) measurements. Out of a variety of commonly used lipid probes only the aminofluorescein-labeled fatty acids HEDAF (5-(N-hexadecanoyl)-aminofluorescein) and TEDAF (5-(N-tetradecanoyl)-aminofluorescein) appear to partition into the plasma membrane. Under all experimental conditions used these molecules show par...

  14. Composition comprising lignin and antidi arrheal component

    DEFF Research Database (Denmark)

    2008-01-01

    The present invention relates to a composition comprising lignin and at least one compound selected from the group consisting of bromelain, papain, tannin, carvacrol, thymol, alliin, allicin, fenugreek seed, egg, poppy, poppy seeds, humic acid, roots, kaolin, catechu, cellulase, flavonoid...

  15. Effects of frying oils' fatty acids profile on the formation of polar lipids components and their retention in French fries over deep-frying process.

    Science.gov (United States)

    Li, Xiaodan; Li, Jinwei; Wang, Yong; Cao, Peirang; Liu, Yuanfa

    2017-12-15

    The effects of frying oils' fatty acids profile on the formation of polar components and their retention in French fries and corresponding deep-fried oils were investigated in the present study, using oils with different fatty acids composition. Our analysis showed that the total polar compounds (TPCs) content in French fries was only slightly lower than that in deep-fried oils, indicating that there was no significant difference considering the amounts of TPCs in French fries and deep-fried oils. Our further analysis showed that different polar components in TPCs distributed differently in deep-fried oils and oils extracted from French fries. Specifically, the level of oligomeric and dimeric triacylglycerols was higher in French fries while oxidized triacylglycerols and diacylglycerols content was higher in deep-fried oils. The different retention of TPCs components in French fries may be explained by their interactions with carbohydrates, which are shown to enhance with the increase of hydrophobic property. Chemometric analysis showed that no correlation between the polar compounds level and saturated fatty acids profile was observed. Meanwhile, the polar compounds content was highly correlated with the formation of trans-C18:1, and a highly positive association between polar compounds and C18:2 content was also observed in palm oil. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Specific Binding of Adamantane Drugs and Direction of their Polar Amines in the Pore of the Influenza M2 Transmembrane Domain in Lipid Bilayers and Dodecylphosphocholine Micelles Determined by NMR Spectroscopy

    Science.gov (United States)

    Cady, Sarah D.; Wang, Jun; Wu, Yibing; DeGrado, William F.; Hong, Mei

    2011-01-01

    The transmembrane domain of the influenza M2 protein (M2TM) forms a tetrameric proton channel important for the virus lifecycle. The proton-channel activity is inhibited by amine-containing adamantyl drugs amantadine and rimantadine, which have been shown to bind specifically to the pore of M2TM near Ser31. However, whether the polar amine points to the N- or C-terminus of the channel has not yet been determined. Elucidating the polar group direction will shed light on the mechanism by which drug binding inhibits this proton channel and will facilitate rational design of new inhibitors. In this study, we determine the polar amine direction using M2TM reconstituted in lipid bilayers as well as DPC micelles. 13C-2H rotational-echo double-resonance NMR experiments of 13C-labeled M2TM and methyl-deuterated rimantadine in lipid bilayers showed that the polar amine pointed to the C-terminus of the channel, with the methyl group close to Gly34. Solution NMR experiments of M2TM in dodecylphosphocholine (DPC) micelles indicate that drug binding causes significant chemical shift perturbations of the protein that are very similar to those seen for M2TM and M2(18–60) bound to lipid bilayers. Specific 2H-labeling of the drugs permitted the assignment of drug-protein cross peaks, which indicate that amantadine and rimantadine bind to the pore in the same fashion as for bilayer-bound M2TM. These results strongly suggest that adamantyl inhibition of M2TM is achieved not only by direct physical occlusion of the pore but also by perturbing the equilibrium constant of the proton-sensing residue His37. The reproduction of the pharmacologically relevant specific pore-binding site in DPC micelles, which was not observed with a different detergent, DHPC, underscores the significant influence of the detergent environment on the functional structure of membrane proteins. PMID:21381693

  17. EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA); Scientific Opinion on the substantiation of a health claim related to Wheat Polar Lipid Extract and protection of the skin against dehydration pursuant to Article 13(5) of Regulation (EC) No 1924/2006

    DEFF Research Database (Denmark)

    Tetens, Inge

    Following an application from Extraction Purification Innovation France, submitted pursuant to Article 13(5) of Regulation (EC) No 1924/2006 via the Competent Authority of France, the Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver an opinion on the scientific...... substantiation of a health claim related to Wheat Polar Lipid Extract and protection of the skin against dehydration. The Panel considers that Wheat Polar Lipid Extract is sufficiently characterised. The claimed effect is “contributes to improve skin hydration”. The target population proposed by the applicant...... can be drawn from one uncontrolled pilot study, nor from one study which was not carried out with the food which is the subject of the claim. In weighing the evidence, the Panel took into account that one human intervention study reported an effect of consumption of Wheat Polar Lipid Extract...

  18. Coating compositions comprising bismuth-alloyed zinc

    DEFF Research Database (Denmark)

    2008-01-01

    The present application discloses (i) a coating composition comprising a particulate zinc-based alloyed material, said material comprising 0.05-0.7% by weight of bismuth (Bi), the D50 of the particulate material being in the range of 2.5-30 µm; (ii) a coated structure comprising a metal structure...... having a first coating of the zinc-containing coating composition applied onto at least a part of the metal structure in a dry film thickness of 5-100 µm; and an outer coating applied onto said zinc-containing coating in a dry film thickness of 30-200 µm; (iii) a particulate zinc-based alloyed material......, wherein the material comprises 0.05-0.7%(w/w) of bismuth (Bi), and wherein the D50 of the particulate material is in the range of 2.5-30 µm; (iv) a composite powder consisting of at least 25%(w/w) of the particulate zinc-based alloyed material, the rest being a particulate material consisting of zinc...

  19. Biocatalytic material comprising multilayer enzyme coated fiber

    Science.gov (United States)

    Kim, Jungbae [Richland, WA; Kwak, Ja Hun [Richland, WA; Grate, Jay W [West Richland, WA

    2009-11-03

    The present invention relates generally to high stability, high activity biocatalytic materials and processes for using the same. The materials comprise enzyme aggregate coatings having high biocatalytic activity and stability useful in heterogeneous environment. These new materials provide a new biocatalytic immobilized enzyme system with applications in bioconversion, bioremediation, biosensors, and biofuel cells.

  20. Experimental study and thermodynamic modeling for determining the effect of non-polar solvent (hexane)/polar solvent (methanol) ratio and moisture content on the lipid extraction efficiency from Chlorella vulgaris.

    Science.gov (United States)

    Malekzadeh, Mohammad; Abedini Najafabadi, Hamed; Hakim, Maziar; Feilizadeh, Mehrzad; Vossoughi, Manouchehr; Rashtchian, Davood

    2016-02-01

    In this research, organic solvent composed of hexane and methanol was used for lipid extraction from dry and wet biomass of Chlorella vulgaris. The results indicated that lipid and fatty acid extraction yield was decreased by increasing the moisture content of biomass. However, the maximum extraction efficiency was attained by applying equivolume mixture of hexane and methanol for both dry and wet biomass. Thermodynamic modeling was employed to estimate the effect of hexane/methanol ratio and moisture content on fatty acid extraction yield. Hansen solubility parameter was used in adjusting the interaction parameters of the model, which led to decrease the number of tuning parameters from 6 to 2. The results indicated that the model can accurately estimate the fatty acid recovery with average absolute deviation percentage (AAD%) of 13.90% and 15.00% for the two cases of using 6 and 2 adjustable parameters, respectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Raft-mediated trafficking of apical resident proteins occurs in both direct and transcytotic pathways in polarized hepatic cells : Role of distinct lipid microdomains

    NARCIS (Netherlands)

    Slimane, TA; Trugnan, G; van Ijzendoorn, SCD; Hoekstra, D

    In polarized hepatic cells, pathways and molecular principles mediating the flow of resident apical bile canalicular proteins have not yet been resolved. Herein, we have investigated apical trafficking of a glycosylphosphatidylinositol-linked and two single transmembrane domain proteins on the one

  2. Downhole transmission system comprising a coaxial capacitor

    Science.gov (United States)

    Hall, David R [Provo, UT; Pixton, David S [Lehi, UT; Johnson, Monte L [Orem, UT; Bartholomew, David B [Springville, UT; Hall, Jr., H. Tracy; Rawle, Michael [Springville, UT

    2011-05-24

    A transmission system in a downhole component comprises a plurality of data transmission elements. A coaxial cable having an inner conductor and an outer conductor is disposed within a passage in the downhole component such that at least one capacitor is disposed in the passage and having a first terminal coupled to the inner conductor and a second terminal coupled to the outer conductor. Preferably the transmission element comprises an electrically conducting coil. Preferably, within the passage a connector is adapted to electrically connect the inner conductor of the coaxial cable and the lead wire. The coaxial capacitor may be disposed between and in electrically communication with the connector and the passage. In another embodiment a connector is adapted to electrical connect a first and a second portion of the inner conductor of the coaxial cable and a coaxial capacitor is in electrical communication with the connector and the passage.

  3. Nanophosphor composite scintillators comprising a polymer matrix

    Science.gov (United States)

    Muenchausen, Ross Edward; Mckigney, Edward Allen; Gilbertson, Robert David

    2010-11-16

    An improved nanophosphor composite comprises surface modified nanophosphor particles in a solid matrix. The nanophosphor particle surface is modified with an organic ligand, or by covalently bonding a polymeric or polymeric precursor material. The surface modified nanophosphor particle is essentially charge neutral, thereby preventing agglomeration of the nanophosphor particles during formation of the composite material. The improved nanophosphor composite may be used in any conventional scintillator application, including in a radiation detector.

  4. Atg6/UVRAG/Vps34-Containing Lipid Kinase Complex Is Required for Receptor Downregulation through Endolysosomal Degradation and Epithelial Polarity during Drosophila Wing Development

    Directory of Open Access Journals (Sweden)

    Péter Lőrincz

    2014-01-01

    Full Text Available Atg6 (Beclin 1 in mammals is a core component of the Vps34 PI3K (III complex, which promotes multiple vesicle trafficking pathways. Atg6 and Vps34 form two distinct PI3K (III complexes in yeast and mammalian cells, either with Atg14 or with UVRAG. The functions of these two complexes are not entirely clear, as both Atg14 and UVRAG have been suggested to regulate both endocytosis and autophagy. In this study, we performed a microscopic analysis of UVRAG, Atg14, or Atg6 loss-of-function cells in the developing Drosophila wing. Both autophagy and endocytosis are seriously impaired and defective endolysosomes accumulate upon loss of Atg6. We show that Atg6 is required for the downregulation of Notch and Wingless signaling pathways; thus it is essential for normal wing development. Moreover, the loss of Atg6 impairs cell polarity. Atg14 depletion results in autophagy defects with no effect on endocytosis or cell polarity, while the silencing of UVRAG phenocopies all but the autophagy defect of Atg6 depleted cells. Thus, our results indicate that the UVRAG-containing PI3K (III complex is required for receptor downregulation through endolysosomal degradation and for the establishment of proper cell polarity in the developing wing, while the Atg14-containing complex is involved in autophagosome formation.

  5. Fibrous composites comprising carbon nanotubes and silica

    Science.gov (United States)

    Peng, Huisheng [Shanghai, CN; Zhu, Yuntian Theodore [Cary, NC; Peterson, Dean E [Los Alamos, NM; Jia, Quanxi [Los Alamos, NM

    2011-10-11

    Fibrous composite comprising a plurality of carbon nanotubes; and a silica-containing moiety having one of the structures: (SiO).sub.3Si--(CH.sub.2).sub.n--NR.sub.1R.sub.2) or (SiO).sub.3Si--(CH.sub.2).sub.n--NCO; where n is from 1 to 6, and R.sub.1 and R.sub.2 are each independently H, CH.sub.3, or C.sub.2H.sub.5.

  6. Method of forming a nanocluster comprising dielectric layer and device comprising such a layer

    NARCIS (Netherlands)

    2009-01-01

    A method of forming a dielectric layer (330) on a further layer (114, 320) of a semiconductor device (300) is disclosed. The method comprises depositing a dielectric precursor compound and a further precursor compound over the further layer (114, 320), the dielectric precursor compound comprising a

  7. New Lipids From Cultured Archaea and Environmental Samples

    Science.gov (United States)

    Summons, R. E.; Meyer-Dombard, D. R.; Bradley, A. S.; Hebting, Y.; Jahnke, L. L.; Embaye, T.; Orphan, V. J.

    2006-12-01

    The intact polar lipids of Archaea comprise cores with isoprenoid hydrocarbon chains with 20, 25 or 40 carbon atoms linked through ether bonds to glycerol. These cores can take the form of diethers or membrane- spanning tetraethers. Together with their wide array of polar head groups, these compounds are structurally diverse and potentially very useful as taxonomic markers for making assessments of microbial diversity independently of genomic approaches. Furthermore, the recalcitrant hydrocarbon chains of these lipids are the only really effective means to identify the presence of Archaea in ancient sedimentary environments. The advent of new LC-MS methods has enabled ready identification and quantification of intact polar lipids in cultures and environmental samples based on comparisons with appropriate standard compounds [1, 2]. However, these LC-MS analyses of intact lipids have also revealed the presence of additional compounds and it is likely that many of these represent chemical structures that are new to science. Elucidating these structures is a major analytical challenge because, generally, only minute amounts of material available for chemical characterization. In order to study these potentially new structures, one layer of information can be obtained by chemical degradation to remove and identify the polar head groups [2]. Cleavage of the ether bonds releases the hydrocarbon chains for their further characterization. One class of core lipids, the 3-hydroxyarchaeols, escaped detection for many years because strong acid treatments in the analysis protocols had destroyed hydroxyl-containing isoprenoid chains. We have now re-examined the lipids of a thermophilic methanogen, M. thermolithotrophicus, using mild procedures and avoiding strong acids. As well as the known compounds archaeol, sn-2-hydroxyarchaeol and sn-3-hydroxyarchaeol, we encountered dihydroxyarchaeol. Moreover, the hydroxylated archaeols were found to exist as a very complex mixture of

  8. Irregular bilayer structure in vesicles prepared from Halobacterium cutirubrum lipids

    Science.gov (United States)

    Lanyi, J. K.

    1974-01-01

    Fluorescent probes were used to study the structure of the cell envelope of Halobacterium cutirubrum, and, in particular, to explore the effect of the heterogeneity of the lipids in this organism on the structure of the bilayers. The fluorescence polarization of perylene was followed in vesicles of unfractionated lipids and polar lipids as a function of temperature in 3.4 M solutions of NaCl, NaNO3, and KSCN, and it was found that vesicles of unfractionated lipids were more perturbed by chaotropic agents than polar lipids. The dependence of the relaxation times of perylene on temperature was studied in cell envelopes and in vesicles prepared from polar lipids, unfractionated lipids, and mixtures of polar and neutral lipids.

  9. Lipid composition of human meibum

    Directory of Open Access Journals (Sweden)

    R. Schnetler

    2013-12-01

    Full Text Available The structure and function of meibomian gland lipids in the tear film are highly complex. Evidence shows that the precorneal tear film consists of discrete layers: the inner mucin layer, the middle aqueous layer and the outer lipid layer. In this review we focus on the outer, biphasic lipid layer of the tear film which consists of a ‘thick’ outer, non-polar layer  and a ‘thin’ inner, polar layer. We discuss the main composition of the polar and non-polar lipids within meibum (wax esters, cholesteryl esters, mono-, di- and tri-acylglycerols, ceramides, phospholipids  et cetera. We address the composition of meibomian lipids in subjects suffering from various ocular diseases in comparison with the composition in healthy individuals. Further analysis is needed to determine whether a correlation exists between the etiology of various ocular diseases and the fluctuation on the lipids as well as to establish whether or not tear lipid analysis can be used as a diagnostic tool.

  10. Electromagnetic radiation absorbers and modulators comprising polyaniline

    Science.gov (United States)

    Epstein, Arthur J.; Ginder, John M.; Roe, Mitchell G.; Hajiseyedjavadi, Hamid

    1992-01-01

    A composition for absorbing electromagnetic radiation, wherein said electromagnetic radiation possesses a wavelength generally in the range of from about 1000 Angstroms to about 50 meters, wherein said composition comprises a polyaniline composition of the formula ##STR1## where y can be equal to or greater than zero, and R.sup.1 and R.sup.2 are independently selected from the group containing of H, --OCH.sub.3, --CH.sub.3, --F, --Cl, --Br, --I, NR.sup.3 .sub.2, --NHCOR.sup.3, --OH, --O.sup.-, SR.sup.3, --OCOR.sup.3, --NO.sub.2, --COOH, --COOR.sup.3, --COR.sup.3, --CHO, and --CN, where R.sup.3 is a C.sub.1 to C.sub.8 alkyl, aryl or aralkyl group.

  11. Modeling superhydrophobic surfaces comprised of random roughness

    Science.gov (United States)

    Samaha, M. A.; Tafreshi, H. Vahedi; Gad-El-Hak, M.

    2011-11-01

    We model the performance of superhydrophobic surfaces comprised of randomly distributed roughness that resembles natural surfaces, or those produced via random deposition of hydrophobic particles. Such a fabrication method is far less expensive than ordered-microstructured fabrication. The present numerical simulations are aimed at improving our understanding of the drag reduction effect and the stability of the air-water interface in terms of the microstructure parameters. For comparison and validation, we have also simulated the flow over superhydrophobic surfaces made up of aligned or staggered microposts for channel flows as well as streamwise or spanwise ridge configurations for pipe flows. The present results are compared with other theoretical and experimental studies. The numerical simulations indicate that the random distribution of surface roughness has a favorable effect on drag reduction, as long as the gas fraction is kept the same. The stability of the meniscus, however, is strongly influenced by the average spacing between the roughness peaks, which needs to be carefully examined before a surface can be recommended for fabrication. Financial support from DARPA, contract number W91CRB-10-1-0003, is acknowledged.

  12. Polarized neutrons

    International Nuclear Information System (INIS)

    Williams, W.G.

    1988-01-01

    The book on 'polarized neutrons' is intended to inform researchers in condensed matter physics and chemistry of the diversity of scientific problems that can be investigated using polarized neutron beams. The contents include chapters on:- neutron polarizers and instrumentation, polarized neutron scattering, neutron polarization analysis experiments and precessing neutron polarization. (U.K.)

  13. Archaeal lipids in oral delivery of therapeutic peptides

    DEFF Research Database (Denmark)

    Jacobsen, Ann-Christin; Jensen, Sara M; Fricker, Gert

    2017-01-01

    Archaea contain membrane lipids that differ from those found in the other domains of life (Eukarya and Bacteria). These lipids consist of isoprenoid chains attached via ether bonds to the glycerol carbons at the sn-2,3 positions. Two types of ether lipids are known, polar diether lipids and bipolar...

  14. Structure and dynamics of H{sub 2}O vis-á-vis phenylalanine recognition at a DPPC lipid membrane via interfacial H-bond types: Insights from polarized FT-IRRAS and ADMP simulations

    Energy Technology Data Exchange (ETDEWEB)

    Sarangi, Nirod Kumar; Ramesh, Nivarthi; Patnaik, Archita [Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036 (India)

    2015-01-14

    Preferential and enantioselective interactions of L-/D-Phenylalanine (L-Phe and D-Phe) and butoxycarbonyl-protected L-/D-Phenylalanine (LPA and DPA) as guest with 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (L-DPPC) as host were tapped by using real time Fourier transform infrared reflection absorption spectroscopy (FT-IRRAS). Polarization-modulated FT-IRRAS of DPPC monolayers above the phenylalanine modified subphases depicted fine structure/conformation differences under considerations of controlled 2D surface pressure. Selective molecular recognition of D-enantiomer over L-enantiomer driven by the DPPC head group via H-bonding and electrostatic interactions was evident spectroscopically. Accordingly, binding constants (K) of 145, 346, 28, and 56 M{sup −1} for LPA, DPA, L-Phe, and D-Phe, respectively, were estimated. The real time FT-IRRAS water bands were strictly conformation sensitive. The effect of micro-solvation on the structure and stability of the 1:1 diastereomeric L-lipid⋯, LPA/DPA and L-lipid⋯, (L/D)-Phe adducts was investigated with the aid of Atom-centered Density Matrix Propagation (ADMP), a first principle quantum mechanical molecular dynamics approach. The phosphodiester fragment was the primary site of hydration where specific solvent interactions were simulated through single- and triple- “water-phosphate” interactions, as water cluster’s “tetrahedral dice” to a “trimeric motif” transformation as a partial de-clusterization was evident. Under all the hydration patterns considered in both static and dynamic descriptions of density functional theory, L-lipid/D-amino acid enantiomer adducts continued to be stable structures while in dynamic systems, water rearranged without getting “squeezed-out” in the process of recognition. In spite of the challenging computational realm of this multiscale problem, the ADMP simulated molecular interactions complying with polarized vibrational spectroscopy unraveled a novel route to chiral

  15. GUIDE FOR POLARIZED NEUTRONS

    Science.gov (United States)

    Sailor, V.L.; Aichroth, R.W.

    1962-12-01

    The plane of polarization of a beam of polarized neutrons is changed by this invention, and the plane can be flipped back and forth quicitly in two directions in a trouble-free manner. The invention comprises a guide having a plurality of oppositely directed magnets forming a gap for the neutron beam and the gaps are spaced longitudinally in a spiral along the beam at small stepped angles. When it is desired to flip the plane of polarization the magnets are suitably rotated to change the direction of the spiral of the gaps. (AEC)

  16. Lipid markers of diet history and their retention during experimental starvation in the Bering Sea euphausiid Thysanoessa raschii

    Science.gov (United States)

    Pleuthner, Rachel L.; Shaw, C. Tracy; Schatz, Megan J.; Lessard, Evelyn J.; Harvey, H. Rodger

    2016-12-01

    Two extended pulsed feeding experiments, following the spring bloom period, investigated lipid retention in the prominent Bering Sea euphausiid (krill) Thysanoessa raschii. These experiments occurred during late spring and early summer of 2010. Concurrent taxonomic analysis of the natural algal community allowed prey type to be linked to lipid composition of the natural communities. In late spring, experimental periods of feeding followed by starvation showed an overall decrease in total lipid for T. raschii. In early summer, no consistent trend was observed for total lipid with the visible presence of storage lipid in some animals. Polar lipids, as phospholipids, were the dominant krill lipid class in both experiments constituting ≥88% of total lipid, and triacylglycerols reached a maximum of 5% of total lipid. The sterols cholesterol and brassicasterol+desmosterol comprised 98-99% of total sterol abundances in T. raschii throughout both experiments, even after feeding periods when alternative sterols (i.e. the algal sterol 24-methylenecholesterol) accounted for up to 39% of sterols in potential food particles. Cholesterol abundance and concentration increased during both incubations, likely due to the metabolism of dietary sterols. Major fatty acids observed in krill included C14:0n, C16:0n, C16:1(n-7), C18:1(n-7), C18:1(n-9), C20:5(n-3), and C22:6(n-3) with the diatom-attributed C16:1(n-7) decreasing in abundance and concentration during starvation. Low concentrations of the dinoflagellate-derived sterol and a novel C28:8 PUFA, typically found in dinoflagellates and prymnesiophytes, indicated predation on protozooplankton in early summer when diatom abundances were low. The stability of lipid distributions over periods of starvation and intermittent feeding suggest that fatty acid and sterol biomarkers present in this polar euphausiid principally reflect long-term diet history rather than short-term feeding episodes.

  17. Sulfurisation of lipids in a marine-influenced lignite

    Energy Technology Data Exchange (ETDEWEB)

    Sandison, C.M.; Alexander, R.; Kagi, R.I.; Boreham, C.J. [Curtin University of Technology, Perth, WA (Australia)

    2002-07-01

    Compelling evidence is presented for the process of lipid sulfurisation in humic coal-forming environments. The production of reduced inorganic sulfides by sulfate-reducing bacteria during a marine transgression, which occurred during early diagenesis, enabled the selective sequestration of functionalised lipids in the polar and asphaltene fractions from the Eocene, marine-influenced Heartbreak Ridge lignite deposit in southeast Western Australia. Nickel boride desulfurisation experiments conducted on these fractions released small but significant quantities of sulfur-bound hydrocarbons. These comprised mostly higher plant triterpanes, C-29 steranes and extended 17beta(H),21beta(H)-hopanes, linked by one sulfur atom at, or close to, functionalised sites in the original natural product precursors. These sulfurised lipids come from the same carbon sources as the free hydrocarbon lipids, except for the sulfurised extended hopanoids, which may be partially derived from a different bacterial source. These results indicate that the selectivity and nature of steroid and hopanoid vulcanisation in coal-forming mires is similar to that observed in other sedimentary environments. However, the diversity of higher plant triterpanes that can be sulfurised in marine transgressed coals is greater than that reported in immature terrestrial coals. This preservation mechanism explains the formation of the structurally related biomarkers in more mature sulfur-rich humic coals.

  18. Nutritional quality in terms of lipid content and fatty acid composition of neutral and polar lipids in the adductor muscle of the oyster Crassostrea gigas (Thunberg, 1794 farmed in the Bizert lagoon (Tunisia in relation with sexual cycle and environmental settings

    Directory of Open Access Journals (Sweden)

    Salwa Dridi

    2017-12-01

    Full Text Available Monthly variations of fatty acid composition of the two fractions polar lipids (PL and neutral lipids (NL in the adductor muscle of cupped oyster Crassostrea gigas, were studied from May 2005 until June 2006 in the Bizert lagoon, related to environmental parameters and reproductive events. C. gigas showed a clear cycle of energy storage and utilization in the site of study. Total PL and NL content varied significantly during the year and showed a negative and significant correlation with the gametogenic condition index which can be explained by transfer of fatty acids from the adductor muscle to gonads to support the gametogenic cycle. Nevertheless, PL and NL have no significant correlations either with temperature or chlorophyll a registered in the site of study. The adductor muscle proved to be less influenced by chlorophyll a richness of the farming environment. The dominance of total polyunsaturated fatty acids (PUFAs over the saturated fatty acids (SFAs and monounsaturated fatty acids (MUFAs in both PL and NL fractions was established throughout the period of study. Oysters analyzed were characterized by high levels of PUFAs n−3 and high n−3/n−6 PUFAs ratio in both PL and NL fractions. PUFAs n−3 and SFAs of PL and PUFAs and SFAs of NL, showed a negative and significant correlation between them. In fact, low temperature values produce generally an increase in the PUFAs percentages in order to maintain the fluidity of cell membranes. We deduce that annual variations of fatty acids content in PL and NL fractions of the adductor muscle of C. gigas seem to be in relation with the reproductive events. According to our results, the adductor muscle tissues were relatively poor in fatty acids (maximum values (% of dry weight of PL and NL respectively were 2.04 ± 0.33 and 1.75 ± 0.9. Lipids fluctuations were not pronounced all over the period of study in the site of sampling due to low effects of the environment richness and phases of

  19. Compositions comprising free-standing two-dimensional nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Barsoum, Michel W.; Gogotsi, Yury; Abdelmalak, Michael Naguib; Mashtalir, Olha

    2017-12-05

    The present invention is directed to methods of transferring urea from an aqueous solution comprising urea to a MXene composition, the method comprising contacting the aqueous solution comprising urea with the MXene composition for a time sufficient to form an intercalated MXene composition comprising urea.

  20. Artificial skin and patient simulator comprising the artificial skin

    NARCIS (Netherlands)

    2011-01-01

    The invention relates to an artificial skin (10, 12, 14), and relates to a patient simulator (100) comprising the artificial skin. The artificial skin is a layered structure comprising a translucent cover layer (20) configured for imitating human or animal skin, and comprising a light emitting layer

  1. Coated silicon comprising material for protection against environmental corrosion

    Science.gov (United States)

    Hazel, Brian Thomas (Inventor)

    2009-01-01

    In accordance with an embodiment of the invention, an article is disclosed. The article comprises a gas turbine engine component substrate comprising a silicon material; and an environmental barrier coating overlying the substrate, wherein the environmental barrier coating comprises cerium oxide, and the cerium oxide reduces formation of silicate glass on the substrate upon exposure to corrodant sulfates.

  2. Membrane Transport across Polarized Epithelia.

    Science.gov (United States)

    Garcia-Castillo, Maria Daniela; Chinnapen, Daniel J-F; Lencer, Wayne I

    2017-09-01

    Polarized epithelial cells line diverse surfaces throughout the body forming selective barriers between the external environment and the internal milieu. To cross these epithelial barriers, large solutes and other cargoes must undergo transcytosis, an endocytic pathway unique to polarized cell types, and significant for the development of cell polarity, uptake of viral and bacterial pathogens, transepithelial signaling, and immunoglobulin transport. Here, we review recent advances in our knowledge of the transcytotic pathway for proteins and lipids. We also discuss briefly the promise of harnessing the molecules that undergo transcytosis as vehicles for clinical applications in drug delivery. Copyright © 2017 Cold Spring Harbor Laboratory Press; all rights reserved.

  3. Towards helium-3 neutron polarizers

    International Nuclear Information System (INIS)

    Tasset, F.

    1995-01-01

    With a large absorption cross-section entirely due to antiparallel spin capture, polarized helium-3 is presently the most promising broad-band polarizer for thermal and epithermal neutrons. Immediate interest was raised amongst the neutron community when a dense gaseous 3 He polarizer was used for the first time in 1988, on a pulsed neutron beam at Los Alamos. With 20 W of laser power on a 30 cm long, 8.6 atm target, 40% 3 He polarization was achieved in a recent polarized electron scattering experiment at SLAC. In this technique the 3 He nuclei are polarized directly at an appropriate high pressure through spin-exchange collisions with a thick, optically pumped rubidium vapor. A different and competitive approach is being presently developed at Mainz University in collaboration with ENS Paris and now the ILL. A discharge is established in pure 3 He at low pressure producing excited metastable atoms which can be optically pumped with infra-red light. Highly effective exchange collision with the atoms remaining in the ground state quickly produces 75% polarization at 1.5 mbar. A truly non-magnetic system then compresses the polarized gas up to several bars as required. The most recent machine comprises a two-stage glass-titanium compressor. In less than 1 h it can inflate a 100 cm 3 target cell with three bars of polarized gas. The very long relaxation times (several days) now being obtained at high pressure with a special metallic coating on the glass walls, the polarized cell can be detached and inserted in the neutron beam as polarizer. We expect 50% 3 He-polarization to be reached soon, allowing such filters to compete favorably with existing Heusler-crystal polarizers at thermal and short neutron wavelengths. It must be stressed that such a system based on a 3 He polarization factory able to feed several passive, transportable, polarizers is well matched to neutron scattering needs. (orig.)

  4. Compositions comprising enhanced graphene oxide structures and related methods

    Science.gov (United States)

    Kumar, Priyank Vijaya; Bardhan, Neelkanth M.; Belcher, Angela; Grossman, Jeffrey

    2016-12-27

    Embodiments described herein generally relate to compositions comprising a graphene oxide species. In some embodiments, the compositions advantageously have relatively high oxygen content, even after annealing.

  5. A comparative study of lipids in Sphagnum species

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Baas, M.; Pancost, R.D.; Geel, B. van

    2000-01-01

    The free lipid compositions of twelve species of Sphagnum were determined by capillary gas chromatography/mass spectrometry as part of a study to identify characteristic lipids for Sphagnum in peat bogs. Complex mixtures of lipids, comprised of C28 C29 sterols, C30 triterpenoids, C16 C30 fatty

  6. Organization of lipids in the tear film: a molecular-level view.

    Directory of Open Access Journals (Sweden)

    Alicja Wizert

    Full Text Available Biophysical properties of the tear film lipid layer are studied at the molecular level employing coarse grain molecular dynamics (MD simulations with a realistic model of the human tear film. In this model, polar lipids are chosen to reflect the current knowledge on the lipidome of the tear film whereas typical Meibomian-origin lipids are included in the thick non-polar lipids subphase. Simulation conditions mimic those experienced by the real human tear film during blinks. Namely, thermodynamic equilibrium simulations at different lateral compressions are performed to model varying surface pressure, and the dynamics of the system during a blink is studied by non-equilibrium MD simulations. Polar lipids separate their non-polar counterparts from water by forming a monomolecular layer whereas the non-polar molecules establish a thick outermost lipid layer. Under lateral compression, the polar layer undulates and a sorting of polar lipids occurs. Moreover, formation of three-dimensional aggregates of polar lipids in both non-polar and water subphases is observed. We suggest that these three-dimensional structures are abundant under dynamic conditions caused by the action of eye lids and that they act as reservoirs of polar lipids, thus increasing stability of the tear film.

  7. Zinc comprising coordination compounds as growth stimulants of cotton seeds

    International Nuclear Information System (INIS)

    Yusupov, Z.N.; Nurmatov, T.M.; Rakhimova, M.M.; Dzhafarov, M.I.; Nikolaeva, T.B.

    1991-01-01

    Present article is devoted to zinc comprising coordination compounds as growth stimulants of cotton seeds. The influence of zinc coordination compounds with physiologically active ligands on germinative energy and seed germination of cotton was studied. The biogical activity and effectiveness of zinc comprising coordination compounds at application them for humidification of cotton seeds was studied as well.

  8. Electrochemical energy storage devices comprising self-compensating polymers

    Science.gov (United States)

    Johnson, Paul; Bautista-Martinez, Jose Antonio; Friesen, Cody; Switzer, Elise

    2018-01-30

    The disclosed technology relates generally to devices comprising conductive polymers and more particularly to electrochemical devices comprising self-compensating conductive polymers. In one aspect, electrochemical energy storage device comprises a negative electrode comprising an active material including a redox-active polymer. The device additionally comprises a positive electrode comprising an active material including a redox-active polymer. The device further comprises an electrolyte material interposed between the negative electrode and positive electrode and configured to conduct mobile counterions therethrough between the negative electrode and positive electrode. At least one of the negative electrode redox-active polymer and the positive electrode redox-active polymer comprises a zwitterionic polymer unit configured to reversibly switch between a zwitterionic state in which the zwitterionic polymer unit has first and second charge centers having opposite charge states that compensate each other, and a non-zwitterionic state in which the zwitterionic polymer unit has one of the first and second charge centers whose charge state is compensated by mobile counterions.

  9. Printhead and inkjet printer comprising such a printhead

    NARCIS (Netherlands)

    2007-01-01

    The invention relates to a printhead comprising multiple substantially closed ink chambers (13), the ink chambers being mutually separated by at least one wall (12), wherein each of the chambers comprises an electro-mechanical converter (15), where actuation of the converter leads to a volume change

  10. Polarization developments

    International Nuclear Information System (INIS)

    Prescott, C.Y.

    1993-07-01

    Recent developments in laser-driven photoemission sources of polarized electrons have made prospects for highly polarized electron beams in a future linear collider very promising. This talk discusses the experiences with the SLC polarized electron source, the recent progress with research into gallium arsenide and strained gallium arsenide as a photocathode material, and the suitability of these cathode materials for a future linear collider based on the parameters of the several linear collider designs that exist

  11. Lipid Nanotechnology

    Directory of Open Access Journals (Sweden)

    Gijsje Koenderink

    2013-02-01

    Full Text Available Nanotechnology is a multidisciplinary field that covers a vast and diverse array of devices and machines derived from engineering, physics, materials science, chemistry and biology. These devices have found applications in biomedical sciences, such as targeted drug delivery, bio-imaging, sensing and diagnosis of pathologies at early stages. In these applications, nano-devices typically interface with the plasma membrane of cells. On the other hand, naturally occurring nanostructures in biology have been a source of inspiration for new nanotechnological designs and hybrid nanostructures made of biological and non-biological, organic and inorganic building blocks. Lipids, with their amphiphilicity, diversity of head and tail chemistry, and antifouling properties that block nonspecific binding to lipid-coated surfaces, provide a powerful toolbox for nanotechnology. This review discusses the progress in the emerging field of lipid nanotechnology.

  12. Neutron polarization

    International Nuclear Information System (INIS)

    Firk, F.W.K.

    1976-01-01

    Some recent experiments involving polarized neutrons are discussed; they demonstrate how polarization studies provide information on fundamental aspects of nuclear structure that cannot be obtained from more traditional neutron studies. Until recently, neutron polarization studies tended to be limited either to very low energies or to restricted regions at higher energies, determined by the kinematics of favorable (p, vector n) and (d, vector n) reactions. With the advent of high intensity pulsed electron and proton accelerators and of beams of vector polarized deuterons, this is no longer the case. One has entered an era in which neutron polarization experiments are now being carried out, in a routine way, throughout the entire range from thermal energies to tens-of-MeV. The significance of neutron polarization studies is illustrated in discussions of a wide variety of experiments that include the measurement of T-invariance in the β-decay of polarized neutrons, a search for the effects of meson exchange currents in the photo-disintegration of the deuteron, the determination of quantum numbers of states in the fission of aligned 235 U and 237 Np induced by polarized neutrons, and the double- and triple-scattering of fast neutrons by light nuclei

  13. Lipid Panel

    Science.gov (United States)

    ... A routine cardiac risk assessment typically includes a fasting lipid panel. Beyond that, research continues into the usefulness of other non-traditional markers of cardiac risk, such as Lp-PLA 2 . A health practitioner may choose to evaluate one or more ...

  14. Polarization holography

    DEFF Research Database (Denmark)

    Nikolova, L.; Ramanujam, P.S.

    Current research into holography is concerned with applications in optically storing, retrieving, and processing information. Polarization holography has many unique properties compared to conventional holography. It gives results in high efficiency, achromaticity, and special polarization...... properties. This books reviews the research carried out in this field over the last 15 years. The authors provide basic concepts in polarization and the propagation of light through anisotropic materials, before presenting a sound theoretical basis for polarization holography. The fabrication...... and characterization of azobenzene based materials, which remain the most efficient for the purpose, is described in detail. This is followed by a description of other materials that are used in polarization holography. An in-depth description of various applications, including display holography and optical storage...

  15. LipidPedia: a comprehensive lipid knowledgebase.

    Science.gov (United States)

    Kuo, Tien-Chueh; Tseng, Yufeng Jane

    2018-04-10

    Lipids are divided into fatty acyls, glycerolipids, glycerophospholipids, sphingolipids, saccharolipids, sterols, prenol lipids and polyketides. Fatty acyls and glycerolipids are commonly used as energy storage, whereas glycerophospholipids, sphingolipids, sterols and saccharolipids are common used as components of cell membranes. Lipids in fatty acyls, glycerophospholipids, sphingolipids and sterols classes play important roles in signaling. Although more than 36 million lipids can be identified or computationally generated, no single lipid database provides comprehensive information on lipids. Furthermore, the complex systematic or common names of lipids make the discovery of related information challenging. Here, we present LipidPedia, a comprehensive lipid knowledgebase. The content of this database is derived from integrating annotation data with full-text mining of 3,923 lipids and more than 400,000 annotations of associated diseases, pathways, functions, and locations that are essential for interpreting lipid functions and mechanisms from over 1,400,000 scientific publications. Each lipid in LipidPedia also has its own entry containing a text summary curated from the most frequently cited diseases, pathways, genes, locations, functions, lipids and experimental models in the biomedical literature. LipidPedia aims to provide an overall synopsis of lipids to summarize lipid annotations and provide a detailed listing of references for understanding complex lipid functions and mechanisms. LipidPedia is available at http://lipidpedia.cmdm.tw. yjtseng@csie.ntu.edu.tw. Supplementary data are available at Bioinformatics online.

  16. Medical preparation container comprising microwave powered sensor assembly

    DEFF Research Database (Denmark)

    2016-01-01

    The present invention relates to a medical preparation container which comprises a microwave powered sensor assembly. The microwave powered sensor assembly comprises a sensor configured to measure a physical property or chemical property of a medical preparation during its heating in a microwave ...... oven. The microwave powered sensor assembly is configured for harvesting energy from microwave radiation emitted by the microwave oven and energize the sensor by the harvested microwave energy.......The present invention relates to a medical preparation container which comprises a microwave powered sensor assembly. The microwave powered sensor assembly comprises a sensor configured to measure a physical property or chemical property of a medical preparation during its heating in a microwave...

  17. Metal-polymer composites comprising nanostructures and applications thereof

    Science.gov (United States)

    Wang, Hsing-Lin [Los Alamos, NM; Jeon, Sea Ho [Dracut, MA; Mack, Nathan H [Los Alamos, NM

    2011-08-02

    Metal-polymer composites, and methods of making and use thereof, said composites comprising a thermally-cured dense polyaniline substrate; an acid dopant; and, metal nanostructure deposits wherein the deposits have a morphology dependent upon the acid dopant.

  18. Immunogenic compositions comprising human immunodeficiency virus (HIV) mosaic Nef proteins

    Science.gov (United States)

    Korber, Bette T [Los Alamos, NM; Perkins, Simon [Los Alamos, NM; Bhattacharya, Tanmoy [Los Alamos, NM; Fischer, William M [Los Alamos, NM; Theiler, James [Los Alamos, NM; Letvin, Norman [Boston, MA; Haynes, Barton F [Durham, NC; Hahn, Beatrice H [Birmingham, AL; Yusim, Karina [Los Alamos, NM; Kuiken, Carla [Los Alamos, NM

    2012-02-21

    The present invention relates to mosaic clade M HIV-1 Nef polypeptides and to compositions comprising same. The polypeptides of the invention are suitable for use in inducing an immune response to HIV-1 in a human.

  19. Dielectric electroactive polymers comprising an ionic supramolecular structure

    DEFF Research Database (Denmark)

    2014-01-01

    The present invention relates to an ionic interpenetrating polymer network comprising at least one elastomer and an ionic supramolecular structure comprising the reaction product of at least two chemical compounds wherein each of said compounds has at least two functional groups and wherein said ...... compounds are able to undergo Lewis acid-base reactions. The interpenetrating polymer network may be used as dielectric electroactive polymers (DEAPs) having a high dielectric permittivity....

  20. Polarized proton target-IV. Operations manual

    International Nuclear Information System (INIS)

    Hill, D.; Fletcher, O.; Moretti, A.; Onesto, F.

    1976-01-01

    Standard operating procedures are presented for the vacuum, cryogenic, and electronic systems of a polarized proton target. The systems are comprised of (1) a target cryostat; (2) a 4 He pumping system; (3) a 3 He pumping system; (4) a microwave system; (5) a magnet and power supply; (6) a computerized polarization monitor; and (7) miscellaneous auxiliary equipment

  1. Ionic polarization

    International Nuclear Information System (INIS)

    Mahan, G.D.

    1992-01-01

    Ferroelectricity occurs in many different kinds of materials. Many of the technologically important solids, which are ferroelectric, can be classified as ionic. Any microscopic theory of ferroelectricity must contain a description of local polarization forces. We have collaborated in the development of a theory of ionic polarization which is quite successful. Its basic assumption is that the polarization is derived from the properties of the individual ions. We have applied this theory successfully to diverse subjects as linear and nonlinear optical response, phonon dispersion, and piezoelectricity. We have developed numerical methods using the local Density approximation to calculate the multipole polarizabilities of ions when subject to various fields. We have also developed methods of calculating the nonlinear hyperpolarizability, and showed that it can be used to explain light scattering experiments. This paper elaborates on this polarization theory

  2. Polarization experiments

    International Nuclear Information System (INIS)

    Halzen, F.

    1977-02-01

    In a theoretical review of polarization experiments two important points are emphasized: (a) their versatility and their relevance to a large variety of aspects of hadron physics (tests of basic symmetries; a probe of strong interaction dynamics; a tool for hadron spectroscopy); (b) the wealth of experimental data on polarization parameters in pp and np scattering in the Regge language and in the diffraction language. (author)

  3. Compositions, methods, and systems comprising fluorous-soluble polymers

    Science.gov (United States)

    Swager, Timothy M.; Lim, Jeewoo; Takeda, Yohei

    2015-10-13

    The present invention generally relates to compositions, methods, and systems comprising polymers that are fluorous-soluble and/or organize at interfaces between a fluorous phase and a non-fluorous phase. In some embodiments, emulsions or films are provided comprising a polymer. The polymers, emulsions, and films can be used in many applications, including for determining, treating, and/or imaging a condition and/or disease in a subject. The polymer may also be incorporated into various optoelectronic device such as photovoltaic cells, organic light-emitting diodes, organic field effect transistors, or the like. In some embodiments, the polymers comprise pi-conjugated backbones, and in some cases, are highly emissive.

  4. The ELBA force field for coarse-grain modeling of lipid membranes.

    Directory of Open Access Journals (Sweden)

    Mario Orsi

    Full Text Available A new coarse-grain model for molecular dynamics simulation of lipid membranes is presented. Following a simple and conventional approach, lipid molecules are modeled by spherical sites, each representing a group of several atoms. In contrast to common coarse-grain methods, two original (interdependent features are here adopted. First, the main electrostatics are modeled explicitly by charges and dipoles, which interact realistically through a relative dielectric constant of unity (ε(r = 1. Second, water molecules are represented individually through a new parametrization of the simple Stockmayer potential for polar fluids; each water molecule is therefore described by a single spherical site embedded with a point dipole. The force field is shown to accurately reproduce the main physical properties of single-species phospholipid bilayers comprising dioleoylphosphatidylcholine (DOPC and dioleoylphosphatidylethanolamine (DOPE in the liquid crystal phase, as well as distearoylphosphatidylcholine (DSPC in the liquid crystal and gel phases. Insights are presented into fundamental properties and phenomena that can be difficult or impossible to study with alternative computational or experimental methods. For example, we investigate the internal pressure distribution, dipole potential, lipid diffusion, and spontaneous self-assembly. Simulations lasting up to 1.5 microseconds were conducted for systems of different sizes (128, 512 and 1058 lipids; this also allowed us to identify size-dependent artifacts that are expected to affect membrane simulations in general. Future extensions and applications are discussed, particularly in relation to the methodology's inherent multiscale capabilities.

  5. Thermoacoustic refrigerators and engines comprising cascading stirling thermodynamic units

    Science.gov (United States)

    Backhaus, Scott; Swift, Greg

    2013-06-25

    The present invention includes a thermoacoustic assembly and method for improved efficiency. The assembly has a first stage Stirling thermal unit comprising a main ambient heat exchanger, a regenerator and at least one additional heat exchanger. The first stage Stirling thermal unit is serially coupled to a first end of a quarter wavelength long coupling tube. A second stage Stirling thermal unit comprising a main ambient heat exchanger, a regenerator, and at least one additional heat exchanger, is serially coupled to a second end of the quarter wavelength long coupling tube.

  6. Polarization measurement for internal polarized gaseous targets

    International Nuclear Information System (INIS)

    Ye Zhenyu; Ye Yunxiu; Lv Haijiang; Mao Yajun

    2004-01-01

    The authors present an introduction to internal polarized gaseous targets, polarization method, polarization measurement method and procedure. To get the total nuclear polarization of hydrogen atoms (including the polarization of the recombined hydrogen molecules) in the target cell, authors have measured the parameters relating to atomic polarization and polarized hydrogen atoms and molecules. The total polarization of the target during our measurement is P T =0.853 ± 0.036. (authors)

  7. DC-to-DC converter comprising a reconfigurable capacitor unit

    NARCIS (Netherlands)

    2008-01-01

    The present invention relates to a configurable trench multi-capacitor device comprising a trench in a semiconductor substrate. The trench has a lateral extension exceeding 10 micrometer and a trench filling includes a number of at least four electrically conductive capacitor-electrode layers. A

  8. Hot gas handling device and motorized vehicle comprising the device

    NARCIS (Netherlands)

    Klein Geltink, J.; Beukers, A.; Van Tooren, M.J.L.; Koussios, S.

    2012-01-01

    The invention relates to a device for handling hot exhaust gasses discharged from an internal combustion engine. The device comprises a housing (2), enclosing a space (3) for transporting the exhaust gasses. The housing (2) is provided with an entrance - opening (4) for the exhaust gasses discharged

  9. Non-cementitious compositions comprising vaterite and methods thereof

    Science.gov (United States)

    Devenney, Martin; Fernandez, Miguel; Morgan, Samuel O.

    2015-09-15

    Non-cementitious compositions and products are provided. The compositions of the invention include a carbonate additive comprising vaterite such as reactive vaterite. Additional aspects of the invention include methods of making and using the non-cementitious compositions and products.

  10. DC-to-DC converter comprising a reconfigurable capacitor unit

    NARCIS (Netherlands)

    Klootwijk, J.H.; Bergveld, H.J.; Roozeboom, F.; Reefman, D.; Ruigrok, J.

    2013-01-01

    The present invention relates to a configurable trench multi-capacitor device comprising a trench in a semiconductor substrate. The trench has a lateral extension exceeding 10 micrometer and a trench filling includes a number of at least four electrically conductive capacitor-electrode layers. A

  11. Sources of polarized neutrons

    International Nuclear Information System (INIS)

    Walter, L.

    1983-01-01

    Various sources of polarized neutrons are reviewed. Monoenergetic source produced with unpolarized or polarized beams, white sources of polarized neutrons, production by transmissions through polarized hydrogen targets and polarized thermal neutronsare discussed, with appropriate applications included. (U.K.)

  12. Mean energy polarized neutron source

    International Nuclear Information System (INIS)

    Aleshin, V.A.; Zaika, N.I.; Kolotyj, V.V.; Prokopenko, V.S.; Semenov, V.S.

    1988-01-01

    Physical bases and realization scheme of a pulsed source of polarized neutrons with the energy of up to 75 MeV are described. The source comprises polarized deuteron source, transport line, low-energy ion and axial injector to the accelerator, U-240 isochronous cyclotron, targets for polarized neutron production, accelerated deuteron transport line and flight bases. The pulsed source of fast neutrons with the energy of up to 75 MeV can provide for highly polarized neutron beams with the intensity by 2-3 orders higher than in the most perfect source of this range which allows one to perform various experiments with high efficiency and energy resolution. 9 refs.; 1 fig

  13. Extraction of lipid components from hibiscus seeds by supercritical carbon dioxide and ethanol mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Holser, Ronald A.; King, J. W. (Jerry W.); Bost, G.

    2002-01-01

    . Phosphatidylcholine and lysophosphatidylcholine were the predominate phospholipids comprising between 50 and 95% of the total phospholipids present. Pressurized extraction techniques provide a rapid method to separate both polar and nonpolar lipids from Hibiscus seeds using carbon dioxide and ethanol mixtures. The seeds require a minimum of processing prior to extraction and the extracts obtained are solvent free and suitable for edible products.

  14. Versatile spin-polarized electron source

    Science.gov (United States)

    Jozwiak, Chris; Park, Cheol -Hwan; Gotlieb, Kenneth; Louie, Steven G.; Hussain, Zahid; Lanzara, Alessandra

    2015-09-22

    One or more embodiments relate generally to the field of photoelectron spin and, more specifically, to a method and system for creating a controllable spin-polarized electron source. One preferred embodiment of the invention generally comprises: method for creating a controllable spin-polarized electron source comprising the following steps: providing one or more materials, the one or more materials having at least one surface and a material layer adjacent to said surface, wherein said surface comprises highly spin-polarized surface electrons, wherein the direction and spin of the surface electrons are locked together; providing at least one incident light capable of stimulating photoemission of said surface electrons; wherein the photon polarization of said incident light is tunable; and inducing photoemission of the surface electron states.

  15. Characterization of Oilseed Lipids from “DHA-Producing Camelina sativa”: A New Transformed Land Plant Containing Long-Chain Omega-3 Oils

    Directory of Open Access Journals (Sweden)

    Maged P. Mansour

    2014-02-01

    Full Text Available New and sustainable sources of long-chain (LC, ≥C20 omega-3 oils containing DHA (docosahexaenoic acid, 22:6ω3 are required to meet increasing demands. The lipid content of the oilseed of a novel transgenic, DHA-producing land plant, Camelina sativa, containing microalgal genes able to produce LC omega-3 oils, contained 36% lipid by weight with triacylglycerols (TAG as the major lipid class in hexane extracts (96% of total lipid. Subsequent chloroform-methanol (CM extraction recovered further lipid (~50% polar lipid, comprising glycolipids and phospholipids and residual TAG. The main phospholipid species were phosphatidyl choline and phosphatidyl ethanolamine. The % DHA was: 6.8% (of total fatty acids in the TAG-rich hexane extract and 4.2% in the polar lipid-rich CM extract. The relative level of ALA (α-linolenic acid, 18:3ω3 in DHA-camelina seed was higher than the control. Major sterols in both DHA- and control camelina seeds were: sitosterol, campesterol, cholesterol, brassicasterol and isofucosterol. C16–C22 fatty alcohols, including iso-branched and odd-chain alcohols were present, including high levels of iso-17:0, 17:0 and 19:0. Other alcohols present were: 16:0, iso-18:0, 18:0 and 18:1 and the proportions varied between the hexane and CM extracts. These iso-branched odd-chain fatty alcohols, to our knowledge, have not been previously reported. These components may be derived from wax esters, or free fatty alcohols.

  16. Recyclable organic solar cells on substrates comprising cellulose nanocrystals (CNC)

    Science.gov (United States)

    Kippelen, Bernard; Fuentes-Hernandez, Canek; Zhou, Yinhua; Moon, Robert; Youngblood, Jeffrey P

    2015-12-01

    Recyclable organic solar cells are disclosed herein. Systems and methods are further disclosed for producing, improving performance, and for recycling the solar cells. In certain example embodiments, the recyclable organic solar cells disclosed herein include: a first electrode; a second electrode; a photoactive layer disposed between the first electrode and the second electrode; an interlayer comprising a Lewis basic oligomer or polymer disposed between the photoactive layer and at least a portion of the first electrode or the second electrode; and a substrate disposed adjacent to the first electrode or the second electrode. The interlayer reduces the work function associated with the first or second electrode. In certain example embodiments, the substrate comprises cellulose nanocrystals that can be recycled. In certain example embodiments, one or more of the first electrode, the photoactive layer, and the second electrode may be applied by a film transfer lamination method.

  17. Resonant power converter comprising adaptive dead-time control

    DEFF Research Database (Denmark)

    2017-01-01

    The invention relates in a first aspect to a resonant power converter comprising: a first power supply rail for receipt of a positive DC supply voltage and a second power supply rail for receipt of a negative DC supply voltage. The resonant power converter comprises a resonant network with an input...... terminal for receipt of a resonant input voltage from a driver circuit. The driver circuit is configured for alternatingly pulling the resonant input voltage towards the positive and negative DC supply voltages via first and second semiconductor switches, respectively, separated by intervening dead......-time periods in accordance with one or more driver control signals. A dead-time controller is configured to adaptively adjusting the dead-time periods based on the resonant input voltage....

  18. Polarization study

    International Nuclear Information System (INIS)

    Nurushev, S.B.

    1989-01-01

    Brief review is presented of the high energy polarization study including experimental data and the theoretical descriptions. The mostimportant proposals at the biggest accelerators and the crucial technical developments are also listed which may become a main-line of spin physics. 35 refs.; 10 figs.; 4 tabs

  19. Polar Stratigraphy

    Science.gov (United States)

    1999-01-01

    These three images were taken on three different orbits over the north polar cap in April 1999. Each shows a different part of the same ice-free trough. The left and right images are separated by a distance of more than 100 kilometers (62 miles). Note the similar layers in each image.

  20. Ortho-Babinet polarization-interrogating filter: an interferometric approach to polarization measurement.

    Science.gov (United States)

    Van Delden, Jay S

    2003-07-15

    A novel, interferometric, polarization-interrogating filter assembly and method for the simultaneous measurement of all four Stokes parameters across a partially polarized irradiance image in a no-moving-parts, instantaneous, highly sensitive manner is described. In the reported embodiment of the filter, two spatially varying linear retarders and a linear polarizer comprise an ortho-Babinet, polarization-interrogating (OBPI) filter. The OBPI filter uniquely encodes the incident ensemble of electromagnetic wave fronts comprising a partially polarized irradiance image in a controlled, deterministic, spatially varying manner to map the complete state of polarization across the image to local variations in a superposed interference pattern. Experimental interferograms are reported along with a numerical simulation of the method.

  1. Multilayer Electroactive Polymer Composite Material Comprising Carbon Nanotubes

    Science.gov (United States)

    Ounaies, Zoubeida (Inventor); Park, Cheol (Inventor); Harrison, Joycelyn S. (Inventor); Holloway, Nancy M. (Inventor); Draughon, Gregory K. (Inventor)

    2009-01-01

    An electroactive material comprises multiple layers of electroactive composite with each layer having unique dielectric, electrical and mechanical properties that define an electromechanical operation thereof when affected by an external stimulus. For example, each layer can be (i) a 2-phase composite made from a polymer with polarizable moieties and an effective amount of carbon nanotubes incorporated in the polymer for a predetermined electromechanical operation, or (ii) a 3-phase composite having the elements of the 2-phase composite and further including a third component of micro-sized to nano-sized particles of an electroactive ceramic incorporated in the polymer matrix.

  2. Characterisation of the Native Lipid Moiety of Echinococcus granulosus Antigen B

    Science.gov (United States)

    Obal, Gonzalo; Ramos, Ana Lía; Silva, Valeria; Lima, Analía; Batthyany, Carlos; Bessio, María Inés; Ferreira, Fernando; Salinas, Gustavo; Ferreira, Ana María

    2012-01-01

    Antigen B (EgAgB) is the most abundant and immunogenic antigen produced by the larval stage (metacestode) of Echinococcus granulosus. It is a lipoprotein, the structure and function of which have not been completely elucidated. EgAgB apolipoprotein components have been well characterised; they share homology with a group of hydrophobic ligand binding proteins (HLBPs) present exclusively in cestode organisms, and consist of different isoforms of 8-kDa proteins encoded by a polymorphic multigene family comprising five subfamilies (EgAgB1 to EgAgB5). In vitro studies have shown that EgAgB apolipoproteins are capable of binding fatty acids. However, the identity of the native lipid components of EgAgB remains unknown. The present work was aimed at characterising the lipid ligands bound to EgAgB in vivo. EgAgB was purified to homogeneity from hydatid cyst fluid and its lipid fraction was extracted using chloroform∶methanol mixtures. This fraction constituted approximately 40–50% of EgAgB total mass. High-performance thin layer chromatography revealed that the native lipid moiety of EgAgB consists of a variety of neutral (mainly triacylglycerides, sterols and sterol esters) and polar (mainly phosphatidylcholine) lipids. Gas-liquid chromatography analysis showed that 16∶0, 18∶0 and 18∶1(n-9) are the most abundant fatty acids in EgAgB. Furthermore, size exclusion chromatography coupled to light scattering demonstrated that EgAgB comprises a population of particles heterogeneous in size, with an average molecular mass of 229 kDa. Our results provide the first direct evidence of the nature of the hydrophobic ligands bound to EgAgB in vivo and indicate that the structure and composition of EgAgB lipoprotein particles are more complex than previously thought, resembling high density plasma lipoproteins. Results are discussed considering what is known on lipid metabolism in cestodes, and taken into account the Echinococcus spp. genomic information regarding both lipid

  3. Characterisation of the native lipid moiety of Echinococcus granulosus antigen B.

    Directory of Open Access Journals (Sweden)

    Gonzalo Obal

    Full Text Available Antigen B (EgAgB is the most abundant and immunogenic antigen produced by the larval stage (metacestode of Echinococcus granulosus. It is a lipoprotein, the structure and function of which have not been completely elucidated. EgAgB apolipoprotein components have been well characterised; they share homology with a group of hydrophobic ligand binding proteins (HLBPs present exclusively in cestode organisms, and consist of different isoforms of 8-kDa proteins encoded by a polymorphic multigene family comprising five subfamilies (EgAgB1 to EgAgB5. In vitro studies have shown that EgAgB apolipoproteins are capable of binding fatty acids. However, the identity of the native lipid components of EgAgB remains unknown. The present work was aimed at characterising the lipid ligands bound to EgAgB in vivo. EgAgB was purified to homogeneity from hydatid cyst fluid and its lipid fraction was extracted using chloroform∶methanol mixtures. This fraction constituted approximately 40-50% of EgAgB total mass. High-performance thin layer chromatography revealed that the native lipid moiety of EgAgB consists of a variety of neutral (mainly triacylglycerides, sterols and sterol esters and polar (mainly phosphatidylcholine lipids. Gas-liquid chromatography analysis showed that 16∶0, 18∶0 and 18∶1(n-9 are the most abundant fatty acids in EgAgB. Furthermore, size exclusion chromatography coupled to light scattering demonstrated that EgAgB comprises a population of particles heterogeneous in size, with an average molecular mass of 229 kDa. Our results provide the first direct evidence of the nature of the hydrophobic ligands bound to EgAgB in vivo and indicate that the structure and composition of EgAgB lipoprotein particles are more complex than previously thought, resembling high density plasma lipoproteins. Results are discussed considering what is known on lipid metabolism in cestodes, and taken into account the Echinococcus spp. genomic information regarding

  4. Nanoscale Cross-Point Resistive Switching Memory Comprising p-Type SnO Bilayers

    KAUST Repository

    Hota, Mrinal Kanti

    2015-02-23

    Reproducible low-voltage bipolar resistive switching is reported in bilayer structures of p-type SnO films. Specifically, a bilayer homojunction comprising SnOx (oxygen-rich) and SnOy (oxygen-deficient) in nanoscale cross-point (300 × 300 nm2) architecture with self-compliance effect is demonstrated. By using two layers of SnO film, a good memory performance is obtained as compared to the individual oxide films. The memory devices show resistance ratio of 103 between the high resistance and low resistance states, and this difference can be maintained for up to 180 cycles. The devices also show good retention characteristics, where no significant degradation is observed for more than 103 s. Different charge transport mechanisms are found in both resistance states, depending on the applied voltage range and its polarity. The resistive switching is shown to originate from the oxygen ion migration and subsequent formation/rupture of conducting filaments.

  5. Photovoltaic device comprising compositionally graded intrinsic photoactive layer

    Science.gov (United States)

    Hoffbauer, Mark A; Williamson, Todd L

    2013-04-30

    Photovoltaic devices and methods of making photovoltaic devices comprising at least one compositionally graded photoactive layer, said method comprising providing a substrate; growing onto the substrate a uniform intrinsic photoactive layer having one surface disposed upon the substrate and an opposing second surface, said intrinsic photoactive layer consisting essentially of In.sub.1-xA.sub.xN,; wherein: i. 0.ltoreq.x.ltoreq.1; ii. A is gallium, aluminum, or combinations thereof; and iii. x is at least 0 on one surface of the intrinsic photoactive layer and is compositionally graded throughout the layer to reach a value of 1 or less on the opposing second surface of the layer; wherein said intrinsic photoactive layer is isothermally grown by means of energetic neutral atom beam lithography and epitaxy at a temperature of 600.degree. C. or less using neutral nitrogen atoms having a kinetic energy of from about 1.0 eV to about 5.0 eV, and wherein the intrinsic photoactive layer is grown at a rate of from about 5 nm/min to about 100 nm/min.

  6. Classifying lipoproteins based on their polar profiles.

    Science.gov (United States)

    Polanco, Carlos; Castañón-González, Jorge Alberto; Buhse, Thomas; Uversky, Vladimir N; Amkie, Rafael Zonana

    2016-01-01

    The lipoproteins are an important group of cargo proteins known for their unique capability to transport lipids. By applying the Polarity index algorithm, which has a metric that only considers the polar profile of the linear sequences of the lipoprotein group, we obtained an analytical and structural differentiation of all the lipoproteins found in UniProt Database. Also, the functional groups of lipoproteins, and particularly of the set of lipoproteins relevant to atherosclerosis, were analyzed with the same method to reveal their structural preference, and the results of Polarity index analysis were verified by an alternate test, the Cumulative Distribution Function algorithm, applied to the same groups of lipoproteins.

  7. Symptomatic lipid storage in carriers for the PNPLA2 gene

    NARCIS (Netherlands)

    Janssen, M.C.H.; Engelen, B.G.M. van; Kapusta, L.; Lammens, M.M.; Dijk, M.; Fischer, J.; Graaf, M. van der; Wevers, R.A.; Fahrleitner, M.; Zimmermann, R.; Morava, E.

    2013-01-01

    Neutral lipid storage disease comprises a heterogeneous group of inherited disorders characterized by severe accumulation of cytoplasmic triglyceride droplets in several tissues and neutrophils. A novel type of autosomal recessive lipid myopathy due to PNPLA2 mutations was recently described with

  8. Membrane domains and polarized trafficking of sphingolipids

    NARCIS (Netherlands)

    Maier, O; Slimane, TA; Hoekstra, D

    The plasma membrane of polarized cells consists of distinct domains, the apical and basolateral membrane that are characterized by a distinct lipid and protein content. Apical protein transport is largely mediated by (glyco)sphingolipid-cholesterol enriched membrane microdomains, so called rafts. In

  9. DUAL POLARIZATION ANTENNA ARRAY WITH VERY LOW CROSS POLARIZATION AND LOW SIDE LOBES

    DEFF Research Database (Denmark)

    1997-01-01

    The present invention relates to an antenna array adapted to radiate or receive electromagnetic waves of one or two polarizations with very low cross polarization and low side lobes. An antenna array comprising many antenna elements, e.g. more than ten antenna elements, is provided in which...... formation of grating lobes are inhibited in selected directions of the radiation and cross polarization within the main lobe is suppressed at least 30 dB below the main lobe peak value. According to a preferred embodiment of the invention, the antenna elements of the antenna array comprise probe-fed patches...

  10. Polythiophenes Comprising Conjugated Pendants for Polymer Solar Cells: A Review

    Directory of Open Access Journals (Sweden)

    Hsing-Ju Wang

    2014-03-01

    Full Text Available Polythiophene (PT is one of the widely used donor materials for solution-processable polymer solar cells (PSCs. Much progress in PT-based PSCs can be attributed to the design of novel PTs exhibiting intense and broad visible absorption with high charge carrier mobility to increase short-circuit current density (Jsc, along with low-lying highest occupied molecular orbital (HOMO levels to achieve large open circuit voltage (Voc values. A promising strategy to tailor the photophysical properties and energy levels via covalently attaching electron donor and acceptor pendants on PTs backbone has attracted much attention recently. The geometry, electron-donating capacity, and composition of conjugated pendants are supposed to be the crucial factors in adjusting the conformation, energy levels, and photovoltaic performance of PTs. This review will go over the most recent approaches that enable researchers to obtain in-depth information in the development of PTs comprising conjugated pendants for PSCs.

  11. Antimalarial activity of compounds comprising a primary benzene sulfonamide fragment.

    Science.gov (United States)

    Andrews, Katherine T; Fisher, Gillian M; Sumanadasa, Subathdrage D M; Skinner-Adams, Tina; Moeker, Janina; Lopez, Marie; Poulsen, Sally-Ann

    2013-11-15

    Despite the urgent need for effective antimalarial drugs with novel modes of action no new chemical class of antimalarial drug has been approved for use since 1996. To address this, we have used a rational approach to investigate compounds comprising the primary benzene sulfonamide fragment as a potential new antimalarial chemotype. We report the in vitro activity against Plasmodium falciparum drug sensitive (3D7) and resistant (Dd2) parasites for a panel of fourteen primary benzene sulfonamide compounds. Our findings provide a platform to support the further evaluation of primary benzene sulfonamides as a new antimalarial chemotype, including the identification of the target of these compounds in the parasite. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Solid polymer electrolyte composite membrane comprising laser micromachined porous support

    Science.gov (United States)

    Liu, Han [Waltham, MA; LaConti, Anthony B [Lynnfield, MA; Mittelsteadt, Cortney K [Natick, MA; McCallum, Thomas J [Ashland, MA

    2011-01-11

    A solid polymer electrolyte composite membrane and method of manufacturing the same. According to one embodiment, the composite membrane comprises a rigid, non-electrically-conducting support, the support preferably being a sheet of polyimide having a thickness of about 7.5 to 15 microns. The support has a plurality of cylindrical pores extending perpendicularly between opposing top and bottom surfaces of the support. The pores, which preferably have a diameter of about 5 microns, are made by laser micromachining and preferably are arranged in a defined pattern, for example, with fewer pores located in areas of high membrane stress and more pores located in areas of low membrane stress. The pores are filled with a first solid polymer electrolyte, such as a perfluorosulfonic acid (PFSA) polymer. A second solid polymer electrolyte, which may be the same as or different than the first solid polymer electrolyte, may be deposited over the top and/or bottom of the first solid polymer electrolyte.

  13. Spontaneous charged lipid transfer between lipid vesicles.

    Science.gov (United States)

    Richens, Joanna L; Tyler, Arwen I I; Barriga, Hanna M G; Bramble, Jonathan P; Law, Robert V; Brooks, Nicholas J; Seddon, John M; Ces, Oscar; O'Shea, Paul

    2017-10-03

    An assay to study the spontaneous charged lipid transfer between lipid vesicles is described. A donor/acceptor vesicle system is employed, where neutrally charged acceptor vesicles are fluorescently labelled with the electrostatic membrane probe Fluoresceinphosphatidylethanolamine (FPE). Upon addition of charged donor vesicles, transfer of negatively charged lipid occurs, resulting in a fluorescently detectable change in the membrane potential of the acceptor vesicles. Using this approach we have studied the transfer properties of a range of lipids, varying both the headgroup and the chain length. At the low vesicle concentrations chosen, the transfer follows a first-order process where lipid monomers are transferred presumably through the aqueous solution phase from donor to acceptor vesicle. The rate of transfer decreases with increasing chain length which is consistent with energy models previously reported for lipid monomer vesicle interactions. Our assay improves on existing methods allowing the study of a range of unmodified lipids, continuous monitoring of transfer and simplified experimental procedures.

  14. Polar Polygons

    Science.gov (United States)

    2005-01-01

    18 August 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows dark-outlined polygons on a frost-covered surface in the south polar region of Mars. In summer, this surface would not be bright and the polygons would not have dark outlines--these are a product of the presence of seasonal frost. Location near: 77.2oS, 204.8oW Image width: width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Spring

  15. Single-component solid lipid nanocarriers prepared with ultra-long chain amphiphilic lipids

    DEFF Research Database (Denmark)

    Wei, Wei; Lu, Xiaonan; Wang, Zegao

    2017-01-01

    HYPOTHESIS: Synthetic sugar alcohol mono-behenates with high melting points, surface activity and resistance to enzymatic lipolysis, are expected to form stable single-component solid lipid nanocarriers (SC-SLNs). The preparation methods and the polar head group of the molecules should affect the......-probe sonication method had a micelle structure with fenofibrate incorporated into a lipid monolayer. This study provides an insight into the systematic development of novel amphiphilic lipids for solid lipid-based drug delivery system.......HYPOTHESIS: Synthetic sugar alcohol mono-behenates with high melting points, surface activity and resistance to enzymatic lipolysis, are expected to form stable single-component solid lipid nanocarriers (SC-SLNs). The preparation methods and the polar head group of the molecules should affect...... using the lipolysis model. The structure and drug distribution of the nanocarriers were studied using AFM and TEM. FINDINGS: Both the polar head group of the molecules and the preparation methods affect the particle size and size distribution. Nanocarriers prepared with sorbitol mono-behenates showed...

  16. Solid polymer electrolyte composite membrane comprising plasma etched porous support

    Science.gov (United States)

    Liu, Han; LaConti, Anthony B.

    2010-10-05

    A solid polymer electrolyte composite membrane and method of manufacturing the same. According to one embodiment, the composite membrane comprises a rigid, non-electrically-conducting support, the support preferably being a sheet of polyimide having a thickness of about 7.5 to 15 microns. The support has a plurality of cylindrical pores extending perpendicularly between opposing top and bottom surfaces of the support. The pores, which preferably have a diameter of about 0.1 to 5 microns, are made by plasma etching and preferably are arranged in a defined pattern, for example, with fewer pores located in areas of high membrane stress and more pores located in areas of low membrane stress. The pores are filled with a first solid polymer electrolyte, such as a perfluorosulfonic acid (PFSA) polymer. A second solid polymer electrolyte, which may be the same as or different than the first solid polymer electrolyte, may be deposited over the top and/or bottom of the first solid polymer electrolyte.

  17. Asteroseismology of KIC 7107778: a binary comprising almost identical subgiants

    Science.gov (United States)

    Li, Yaguang; Bedding, Timothy R.; Li, Tanda; Bi, Shaolan; Murphy, Simon J.; Corsaro, Enrico; Chen, Li; Tian, Zhijia

    2018-05-01

    We analyse an asteroseismic binary system: KIC 7107778, a non-eclipsing, unresolved target, with solar-like oscillations in both components. We used Kepler short cadence time series spanning nearly 2 yr to obtain the power spectrum. Oscillation mode parameters were determined using Bayesian inference and a nested sampling Monte Carlo algorithm with the DIAMONDS package. The power profiles of the two components fully overlap, indicating their close similarity. We modelled the two stars with MESA and calculated oscillation frequencies with GYRE. Stellar fundamental parameters (mass, radius, and age) were estimated by grid modelling with atmospheric parameters and the oscillation frequencies of l = 0, 2 modes as constraints. Most l = 1 mixed modes were identified with models searched using a bisection method. Stellar parameters for the two sub-giant stars are MA = 1.42 ± 0.06 M⊙, MB = 1.39 ± 0.03 M⊙, RA = 2.93 ± 0.05 R⊙, RB = 2.76 ± 0.04 R⊙, tA = 3.32 ± 0.54 Gyr and tB = 3.51 ± 0.33 Gyr. The mass difference of the system is ˜1 per cent. The results confirm their simultaneous birth and evolution, as is expected from binary formation. KIC 7107778 comprises almost identical twins, and is the first asteroseismic sub-giant binary to be detected.

  18. Strategic Polarization.

    Science.gov (United States)

    Kalai, Adam; Kalai, Ehud

    2001-08-01

    In joint decision making, similarly minded people may take opposite positions. Consider the example of a marriage in which one spouse gives generously to charity while the other donates nothing. Such "polarization" may misrepresent what is, in actuality, a small discrepancy in preferences. It may be that the donating spouse would like to see 10% of their combined income go to charity each year, while the apparently frugal spouse would like to see 8% donated. A simple game-theoretic analysis suggests that the spouses will end up donating 10% and 0%, respectively. By generalizing this argument to a larger class of games, we provide strategic justification for polarization in many situations such as debates, shared living accommodations, and disciplining children. In some of these examples, an arbitrarily small disagreement in preferences leads to an arbitrarily large loss in utility for all participants. Such small disagreements may also destabilize what, from game-theoretic point of view, is a very stable equilibrium. Copyright 2001 Academic Press.

  19. Membrane-spanning lipids for an uncompromised monitoring of membrane fusion and intermembrane lipid transfer

    Science.gov (United States)

    Schwarzmann, Günter; Breiden, Bernadette; Sandhoff, Konrad

    2015-01-01

    A Förster resonance energy transfer-based fusion and transfer assay was developed to study, in model membranes, protein-mediated membrane fusion and intermembrane lipid transfer of fluorescent sphingolipid analogs. For this assay, it became necessary to apply labeled reporter molecules that are resistant to spontaneous as well as protein-mediated intermembrane transfer. The novelty of this assay is the use of nonextractable fluorescent membrane-spanning bipolar lipids. Starting from the tetraether lipid caldarchaeol, we synthesized fluorescent analogs with fluorophores at both polar ends. In addition, we synthesized radioactive glycosylated caldarchaeols. These labeled lipids were shown to stretch through bilayer membranes rather than to loop within a single lipid layer of liposomes. More important, the membrane-spanning lipids (MSLs) in contrast to phosphoglycerides proved to be nonextractable by proteins. We could show that the GM2 activator protein (GM2AP) is promiscuous with respect to glycero- and sphingolipid transfer. Saposin (Sap) B also transferred sphingolipids albeit with kinetics different from GM2AP. In addition, we could unambiguously show that the recombinant activator protein Sap C x His6 induced membrane fusion rather than intermembrane lipid transfer. These findings showed that these novel MSLs, in contrast with fluorescent phosphoglycerolipids, are well suited for an uncompromised monitoring of membrane fusion and intermembrane lipid transfer. PMID:26269359

  20. Membrane-spanning lipids for an uncompromised monitoring of membrane fusion and intermembrane lipid transfer.

    Science.gov (United States)

    Schwarzmann, Günter; Breiden, Bernadette; Sandhoff, Konrad

    2015-10-01

    A Förster resonance energy transfer-based fusion and transfer assay was developed to study, in model membranes, protein-mediated membrane fusion and intermembrane lipid transfer of fluorescent sphingolipid analogs. For this assay, it became necessary to apply labeled reporter molecules that are resistant to spontaneous as well as protein-mediated intermembrane transfer. The novelty of this assay is the use of nonextractable fluorescent membrane-spanning bipolar lipids. Starting from the tetraether lipid caldarchaeol, we synthesized fluorescent analogs with fluorophores at both polar ends. In addition, we synthesized radioactive glycosylated caldarchaeols. These labeled lipids were shown to stretch through bilayer membranes rather than to loop within a single lipid layer of liposomes. More important, the membrane-spanning lipids (MSLs) in contrast to phosphoglycerides proved to be nonextractable by proteins. We could show that the GM2 activator protein (GM2AP) is promiscuous with respect to glycero- and sphingolipid transfer. Saposin (Sap) B also transferred sphingolipids albeit with kinetics different from GM2AP. In addition, we could unambiguously show that the recombinant activator protein Sap C x His6 induced membrane fusion rather than intermembrane lipid transfer. These findings showed that these novel MSLs, in contrast with fluorescent phosphoglycerolipids, are well suited for an uncompromised monitoring of membrane fusion and intermembrane lipid transfer. Copyright © 2015 by the American Society for Biochemistry and Molecular Biology, Inc.

  1. Polarized secondary radioactive beams

    International Nuclear Information System (INIS)

    Zaika, N.I.

    1992-01-01

    Three methods of polarized radioactive nuclei beam production: a) a method nuclear interaction of the non-polarized or polarized charged projectiles with target nuclei; b) a method of polarization of stopped reaction radioactive products in a special polarized ion source with than following acceleration; c) a polarization of radioactive nuclei circulating in a storage ring are considered. Possible life times of the radioactive ions for these methods are determined. General schemes of the polarization method realizations and depolarization problems are discussed

  2. Polar crane

    International Nuclear Information System (INIS)

    Makosinski, S.

    1981-01-01

    In many applications polar cranes have to be repeatedly positioned with high accuracy. A guidance system is disclosed which has two pairs of guides. Each guide consists of two rollers carried by a sheave rotatable mounted on the crane bridge, the rollers being locatable one on each side of a guideway, e.g. the circular track on which the bridge runs. The pairs of guides are interconnected by respective rope loops which pass around and are locked to the respective pairs of sheaves in such a manner that movement of one guide results in equal movement of the other guide in a sense to maintain the repeatability of positioning of the centre of the bridge. A hydraulically-linked guide system is also described. (author)

  3. Lipid packing drives the segregation of transmembrane helices into disordered lipid domains in model membranes

    NARCIS (Netherlands)

    Schaefer, Lars V.; de Jong, Djurre H.; Holt, Andrea; Rzepiela, Andrzej J.; de Vries, Alex H.; Poolman, Bert; Killian, J. Antoinette; Marrink, Siewert J.

    2011-01-01

    Cell membranes are comprised of multicomponent lipid and protein mixtures that exhibit a complex partitioning behavior. Regions of structural and compositional heterogeneity play a major role in the sorting and self-assembly of proteins, and their clustering into higher-order oligomers. Here, we use

  4. Adsorption of human tear lipocalin to human meibomian lipid films.

    Science.gov (United States)

    Millar, Thomas J; Mudgil, Poonam; Butovich, Igor A; Palaniappan, Chendur K

    2009-01-01

    Tear lipocalin (Tlc) is a major lipid binding protein in tears and is thought to have an important role in stabilizing the Meibomian lipid layer by transferring lipids to it from the aqueous layer or ocular surface, or by adsorbing to it directly. These possible roles have been investigated in vitro using human Tlc. Tlc was purified from human tears by size exclusion chromatography followed by ion exchange chromatography. Three additional samples of the Tlc were prepared by lipidation, delipidation, and relipidation. The lipids extracted from the purified Tlc were analyzed by HPLC-MS followed by fragmentation. Adsorption of these different forms of Tlc to a human Meibomian lipid film spread on the surface of an artificial tear buffer in a Langmuir trough were observed by recording changes in the pressure with time (Pi-T profile) and monitoring the appearance of the film microscopically. These results were compared with similar experiments using a bovine Meibomian lipid film. The results indicated that Tlc binds slowly to a human Meibomian lipid film compared with lysozyme or lactoferrin, even at 37 degrees C. The adsorption of Tlc to a human Meibomian lipid film was very different from its adsorption to a bovine Meibomian lipid film, indicating the nature of the lipids in the film is critical to the adsorption process. Similarly, the different forms of Tlc had quite distinct adsorption patterns, as indicated both by changes in Pi-T profiles and the microscopic appearance of the films. It was concluded that human Tlc was capable of adsorbing to and penetrating into a Meibomian lipid layer, but this process is very complex and depends on both the types of lipids bound to Tlc and the lipid complement comprising the Meibomian lipid film.

  5. Adsorption of Human Tear Lipocalin to Human Meibomian Lipid Films

    Science.gov (United States)

    Millar, Thomas J.; Mudgil, Poonam; Butovich, Igor A.; Palaniappan, Chendur K.

    2009-01-01

    Purpose Tear lipocalin (Tlc) is a major lipid binding protein in tears and is thought to have an important role in stabilizing the Meibomian lipid layer by transferring lipids to it from the aqueous layer or ocular surface, or by adsorbing to it directly. These possible roles have been investigated in vitro using human Tlc. Methods Tlc was purified from human tears by size exclusion chromatography followed by ion exchange chromatography. Three additional samples of the Tlc were prepared by lipidation, delipidation, and relipidation. The lipids extracted from the purified Tlc were analyzed by HPLC-MS followed by fragmentation. Adsorption of these different forms of Tlc to a human Meibomian lipid film spread on the surface of an artificial tear buffer in a Langmuir trough were observed by recording changes in the pressure with time (∏-T profile) and monitoring the appearance of the film microscopically. These results were compared with similar experiments using a bovine Meibomian lipid film. Results The results indicated that Tlc binds slowly to a human Meibomian lipid film compared with lysozyme or lactoferrin, even at 37°C. The adsorption of Tlc to a human Meibomian lipid film was very different from its adsorption to a bovine Meibomian lipid film, indicating the nature of the lipids in the film is critical to the adsorption process. Similarly, the different forms of Tlc had quite distinct adsorption patterns, as indicated both by changes in ∏-T profiles and the microscopic appearance of the films. Conclusions It was concluded that human Tlc was capable of adsorbing to and penetrating into a Meibomian lipid layer, but this process is very complex and depends on both the types of lipids bound to Tlc and the lipid complement comprising the Meibomian lipid film. PMID:18757516

  6. Nuclear polarization and neutrons

    International Nuclear Information System (INIS)

    Glaettli, H.

    1985-01-01

    Different possibilities for the use of polarized nuclei in thermal neutron scattering on condensed matter are reviewed. Highly polarized nuclei are the starting point for studying dipolar magnetic order. Systematic measurement of spin-dependent scattering lengths is possible on samples with polarized nuclei. Highly polarized hydrogen should help to unravel complicated structures in chemistry and biology. The use of polarized proton targets as an energy-independent neutron polarizer in the thermal and epithermal region should be considered afresh. (author)

  7. A comparative study: the impact of different lipid extraction methods on current microalgal lipid research

    Science.gov (United States)

    2014-01-01

    Microalgae cells have the potential to rapidly accumulate lipids, such as triacylglycerides that contain fatty acids important for high value fatty acids (e.g., EPA and DHA) and/or biodiesel production. However, lipid extraction methods for microalgae cells are not well established, and there is currently no standard extraction method for the determination of the fatty acid content of microalgae. This has caused a few problems in microlagal biofuel research due to the bias derived from different extraction methods. Therefore, this study used several extraction methods for fatty acid analysis on marine microalga Tetraselmis sp. M8, aiming to assess the potential impact of different extractions on current microalgal lipid research. These methods included classical Bligh & Dyer lipid extraction, two other chemical extractions using different solvents and sonication, direct saponification and supercritical CO2 extraction. Soxhlet-based extraction was used to weigh out the importance of solvent polarity in the algal oil extraction. Coupled with GC/MS, a Thermogravimetric Analyser was used to improve the quantification of microalgal lipid extractions. Among these extractions, significant differences were observed in both, extract yield and fatty acid composition. The supercritical extraction technique stood out most for effective extraction of microalgal lipids, especially for long chain unsaturated fatty acids. The results highlight the necessity for comparative analyses of microalgae fatty acids and careful choice and validation of analytical methodology in microalgal lipid research. PMID:24456581

  8. Lipid lateral organization on giant unilamellar vesicles containing lipopolysaccharides

    DEFF Research Database (Denmark)

    Kubiak, Jakub; Brewer, Jonathan R.; Hansen, Søren

    2011-01-01

    15 mol % for LPS-smooth and LPS-Ra, and up to 25 mol % for LPS-Rc and LPS-Rd (with respect to total lipids). We used the GUVs to evaluate the impact of different LPS species on the lateral structure of the host membrane (i.e., E. coli polar lipid extract). Rhodamine-DPPE-labeled GUVs show...... model membranes, and that the size of these domains depends on the chemical structure and concentration of the LPSs....

  9. Localization and Orientation of Xanthophylls in a Lipid Bilayer

    OpenAIRE

    Grudzinski, Wojciech; Nierzwicki, Lukasz; Welc, Renata; Reszczynska, Emilia; Luchowski, Rafal; Czub, Jacek; Gruszecki, Wieslaw I.

    2017-01-01

    Xanthophylls (polar carotenoids) play diverse biological roles, among which are modulation of the physical properties of lipid membranes and protection of biomembranes against oxidative damage. Molecular mechanisms underlying these functions are intimately related to the localization and orientation of xanthophyll molecules in lipid membranes. In the present work, we address the problem of localization and orientation of two xanthophylls present in the photosynthetic apparatus of plants and i...

  10. Magnetoresistance in single-electron transistors comprising a superconducting island with ferromagnetic leads

    Science.gov (United States)

    Mizugaki, Yoshinao; Takiguchi, Masashi; Tamura, Nobuyuki; Shimada, Hiroshi

    2018-03-01

    We report electric and magnetic field responses of single-electron transistors (SETs) comprising a superconducting island with ferromagnetic (FM) leads. We fabricated two SETs, one of which had relatively high resistance and the other had relatively low resistance. The SETs had two states for the gate charge: SET-ON or SET-OFF. They also had two states for the FM lead magnetization: parallel (P) or anti-parallel (AP) configuration. Current-voltage characteristics of four SET states (“P & SET-ON,” “P & SET-OFF,” “AP & SET-ON,” and “AP & SET-OFF”) were measured at approximately 0.1 K in a compact dilution refrigerator. Magnetoresistance ratio (MRR) values were obtained for the SET-ON and SET-OFF states, respectively. The higher-resistance SET1 exhibited positive MRR values for all measured bias voltages. The MRR enhancement was confirmed for the SET-OFF state, which agreed well with the co-tunneling model. The lower-resistance SET2, on the other hand, exhibited negative and positive MRR values for higher and lower bias voltage conditions, respectively. The bias voltage for the MRR polarity reversal was changed by the gate voltage. It was also confirmed that the co-tunneling model was partially valid for negative MRR values.

  11. Biosynthesis of archaeal membrane ether lipids

    Directory of Open Access Journals (Sweden)

    Samta eJain

    2014-11-01

    Full Text Available A vital function of the cell membrane in all living organism is to maintain the membrane permeability barrier and fluidity. The composition of the phospholipid bilayer is distinct in archaea when compared to bacteria and eukarya. In archaea, isoprenoid hydrocarbon side chains are linked via an ether bond to the sn-glycerol-1-phosphate backbone. In bacteria and eukarya on the other hand, fatty acid side chains are linked via an ester bond to the sn-glycerol-3-phosphate backbone. The polar head groups are globally shared in the three domains of life. The unique membrane lipids of archaea have been implicated not only in the survival and adaptation of the organisms to extreme environments but also to form the basis of the membrane composition of the last universal common ancestor (LUCA. In nature, a diverse range of archaeal lipids is found, the most common are the diether (or archaeol and the tetraether (or caldarchaeol lipids that form a monolayer. Variations in chain length, cyclization and other modifications lead to diversification of these lipids. The biosynthesis of these lipids is not yet well understood however progress in the last decade has led to a comprehensive understanding of the biosynthesis of archaeol. This review describes the current knowledge of the biosynthetic pathway of archaeal ether lipids; insights on the stability and robustness of archaeal lipid membranes; and evolutionary aspects of the lipid divide and the last universal common ancestor LUCA. It examines recent advances made in the field of pathway reconstruction in bacteria.

  12. Lipids of Parasitic and Saprophytic Leptospires

    Science.gov (United States)

    Johnson, R. C.; Livermore, B. P.; Walby, Judith K.; Jenkin, H. M.

    1970-01-01

    The lipid composition of five parasitic and six saprophytic leptospires was compared. Lipids comprise 18 to 26% of the dry weight of the cells after chloroform-methanol extraction. No residual (bound) lipid was found after acid or alkaline hydrolysis of the extracted residue. The total lipid was composed of 60 to 70% phospholipid, and the remaining lipid was free fatty acids. The phospholipid fraction contained phosphatidylethanolamine as the major component, and phosphatidylglycerol and diphosphatidylglycerol were minor components with traces of lysophatidylethanolamine sometimes found. The major fatty acids of leptospires were hexadecanoic, hexadecenoic, and octadecenoic acids. Both the unusual cis-11-hexadecenoic acid and the more common cis-9-hexadecenoic acid were synthesized by the leptospires. Neither the parasitic nor the saprophytic leptospires can chain elongate fatty acids. However, they were capable of β-oxidation of fatty acids. Both groups of leptospires desaturate fatty acids by an aerobic pathway. When the parasite canicola was cultivated on octadecanoic acid, 87% of the hexadecenoic acid was the 11 isomer, whereas the saprophyte semeranga consisted of 10% of this isomer. In addition, the saprophytic leptospires contained more tetradecanoic acid than the parasites. No differences were observed in the lipid composition of virulent and avirulent strains of canicola. PMID:16557833

  13. Lipid exchange by ultracentrifugation

    DEFF Research Database (Denmark)

    Drachmann, Nikolaj Düring; Olesen, Claus

    2014-01-01

    , and the complex interplay between the lipids and the P-type ATPases are still not well understood. We here describe a robust method to exchange the majority of the lipids surrounding the ATPase after solubilisation and/or purification with a target lipid of interest. The method is based on an ultracentrifugation...... step, where the protein sample is spun through a dense buffer containing large excess of the target lipid, which results in an approximately 80-85 % lipid exchange. The method is a very gently technique that maintains protein folding during the process, hence allowing further characterization...

  14. Neutron polarization in polarized 3He targets

    International Nuclear Information System (INIS)

    Friar, J.L.; Gibson, B.F.; Payne, G.L.; Bernstein, A.M.; Chupp, T.E.

    1990-01-01

    Simple formulas for the neutron and proton polarizations in polarized 3 He targets are derived assuming (1) quasielastic final states; (2) no final-state interactions; (3) no meson-exchange currents; (4) large momentum transfers; (5) factorizability of 3 He SU(4) response-function components. Numerical results from a wide variety of bound-state solutions of the Faddeev equations are presented. It is found that this simple model predicts the polarization of neutrons in a fully polarized 3 He target to be 87%, while protons should have a slight residual polarization of -2.7%. Numerical studies show that this model works very well for quasielastic electron scattering

  15. Lipid composition of positively buoyant eggs of reef building corals

    Science.gov (United States)

    Arai, Iakayuki; Kato, Misako; Heyward, Andrew; Ikeda, Yutaka; Iizuka, Tokio; Maruyama, Tadashi

    1993-07-01

    Lipid composition of the eggs of three reef building corals, Acropora millepora, A. tenuis and Montipora digitata, were determined. Sixty to 70% of the egg dry weight was lipid, which consisted of wax esters (69.5 81.8%), triacylglycerols (1.1 8.4%) and polar lipids c/mainly phospholipids (11.9 13.2%). Montipora digitata also contained some polar lipids typical of the thylakoid membrane in chloroplasts, probably due to the presence of symbiotic zooxanthellae in the eggs. The wax esters appeared to be the major contributor to positive buoyancy of the eggs, and specific gravity of wax esters in A. millepora was estimated to be 0.92. Among the fatty acids of the wax esters, 34.9 51.3% was hexadecanoic acid (16:0) while the major fatty acids in polar lipids were octadecenoic acid (18:1), hexadecanoic acid (16:0), eicosapentaenoic acid (20:5) and eicosatetraenoic acid (20:4). The wax ester appears to be the main component of the 4.5 6.0 μm diameter lipid droplets which fill most of the central mass of the coral eggs.

  16. Lipid Structure in Triolein Lipid Droplets

    DEFF Research Database (Denmark)

    Chaban, Vitaly V; Khandelia, Himanshu

    2014-01-01

    of a mass of hydrophobic lipid esters coved by phospholipid monolayer. The small size and unique architecture of LDs makes it complicated to study LD structure by modern experimental methods. We discuss coarse-grained molecular dynamics (MD) simulations of LD formation in systems containing 1-palmitoyl-2...... to coarse-grained simulations, the presence of PE lipids at the interface has a little impact on distribution of components and on the overall LD structure. (4) The thickness of the lipid monolayer at the surface of the droplet is similar to the thickness of one leaflet of a bilayer. Computer simulations......Lipid droplets (LDs) are primary repositories of esterified fatty acids and sterols in animal cells. These organelles originate on the lumenal or cytoplasmic side of endoplasmic reticulum (ER) membrane and are released to the cytosol. In contrast to other intracellular organelles, LDs are composed...

  17. On the interaction between fluoxetine and lipid membranes: Effect of the lipid composition

    Science.gov (United States)

    Pham, Vy T.; Nguyen, Trinh Q.; Dao, Uyen P. N.; Nguyen, Trang T.

    2018-02-01

    Molecular interaction between the antidepressant fluoxetine and lipid bilayers was investigated in order to provide insights into the drug's incorporation to lipid membranes. In particular, the effects of lipid's unsaturation degree and cholesterol content on the partitioning of fluoxetine into large unilamellar vesicles (LUVs) comprised of unsaturated 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and saturated 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) were evaluated using second derivative spectrophotometry and Attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR). It was found that fluoxetine partitioned to a greater extent into the liquid-crystalline DOPC LUVs than into the solid-gel DPPC LUVs. The lipid physical state dependence of drug partitioning was verified by increasing the temperature in which the partition coefficient of fluoxetine significantly increased upon the change of the lipid phase from solid-gel to liquid-crystalline. The incorporation of 28 mol% cholesterol into the LUVs exerted a significant influence on the drug partitioning into both DOPC and DPPC LUVs. The ATR-FTIR study revealed that fluoxetine perturbed the conformation of DOPC more strongly than that of DPPC due to the cis-double bonds in the lipid acyl chains. Fluoxetine possibly bound to the carbonyl moiety of the lipids through the hydrogen bonding formation while displaced some water molecules surrounding the PO2- regions of the lipid head groups. Cholesterol, however, could lessen the interaction between fluoxetine and the carbonyl groups of both DOPC and DPPC LUVs. These findings provided a better understanding of the role of lipid structure and cholesterol on the interaction between fluoxetine and lipid membranes, shedding more light into the drug's therapeutic action.

  18. Optical properties of polarization-dependent geometrical phase elements with partially polarized light

    International Nuclear Information System (INIS)

    Gorodetski, Y.; Biener, G.; Niv, A.; Kleiner, V.; Hasman, E.

    2005-01-01

    Full Text:The behavior of geometrical phase elements illuminated with partially polarized monochromatic beams is being theoretically as well as experimentally investigated. The element discussed in this paper is composed of wave plates with retardation and space-variant orientation angle. We found that a beam emerging from such an element comprises two polarization orders of right and left-handed circularly polarized states with conjugate geometrical phase modification. This phase equals twice the orientation angle of the space-variant wave plate comprising the element. Apart from the two polarization orders, the emerging beam coherence polarization matrix comprises a matrix termed as the vectorial interference matrix. This matrix contains the information concerning the correlation between the two orthogonal circularly polarized portions of the incident beam. In this paper we measure this correlation by a simple interference experiment. Furthermore, we found that the equivalent mutual intensity of the emerging beam is being modulated according to the geometrical phase induced by the element. Other interesting phenomena along propagation will be discussed theoretically and experimentally demonstrated. We demonstrate experimentally our analysis by using a spherical geometrical phase element, which is realized by use of space-variant sub wavelength grating and illuminated with a CO 2 laser radiation of 10.6μm wavelength

  19. Fatty acid methyl ester profiles of bat wing surface lipids.

    Science.gov (United States)

    Pannkuk, Evan L; Fuller, Nathan W; Moore, Patrick R; Gilmore, David F; Savary, Brett J; Risch, Thomas S

    2014-11-01

    Sebocytes are specialized epithelial cells that rupture to secrete sebaceous lipids (sebum) across the mammalian integument. Sebum protects the integument from UV radiation, and maintains host microbial communities among other functions. Native glandular sebum is composed primarily of triacylglycerides (TAG) and wax esters (WE). Upon secretion (mature sebum), these lipids combine with minor cellular membrane components comprising total surface lipids. TAG and WE are further cleaved to smaller molecules through oxidation or host enzymatic digestion, resulting in a complex mixture of glycerolipids (e.g., TAG), sterols, unesterified fatty acids (FFA), WE, cholesteryl esters, and squalene comprising surface lipid. We are interested if fatty acid methyl ester (FAME) profiling of bat surface lipid could predict species specificity to the cutaneous fungal disease, white nose syndrome (WNS). We collected sebaceous secretions from 13 bat spp. using Sebutape(®) and converted them to FAME with an acid catalyzed transesterification. We found that Sebutape(®) adhesive patches removed ~6× more total lipid than Sebutape(®) indicator strips. Juvenile eastern red bats (Lasiurus borealis) had significantly higher 18:1 than adults, but 14:0, 16:1, and 20:0 were higher in adults. FAME profiles among several bat species were similar. We concluded that bat surface lipid FAME profiling does not provide a robust model predicting species susceptibility to WNS. However, these results provide baseline data that can be used for lipid roles in future ecological studies, such as life history, diet, or migration.

  20. Biosynthesis and function of plant lipids

    International Nuclear Information System (INIS)

    Thomson, W.W.; Mudd, J.B.; Gibbs, M.

    1983-01-01

    The Sixth Annual Symposium in Botany and Plant Physiology was held January 13-15, 1983, at the University of California, Riverside. This volume comprises the papers that were presented. Subjects discussed at the symposium covered a wide range in the field of plant lipids. Biosynthesis of lipids occupied an important fraction of the presentations at the symposium. Subjects included detailed studies of the enzymes of fatty acid synthesis, several discussions of the incorporation of fatty acids into glycerolipids and the further modification of the fatty acids, and the synthesis of glycerolipids and desaturation of fatty acids in both maturing oilseeds and chloroplasts. The physicochemical studies of glycerolipids and sterols in artificial membranes have led to distinct conclusions about their behaviour which must be relevant in the biological membrane. Results on the functional consequences of modifying the galactolipid composition in the chloroplast were an encouraging sign of progress in the attempts to relate membrane lipid composition to physiological function

  1. Polarized electron sources

    International Nuclear Information System (INIS)

    Prepost, R.

    1994-01-01

    The fundamentals of polarized electron sources are described with particular application to the Stanford Linear Accelerator Center. The SLAC polarized electron source is based on the principle of polarized photoemission from Gallium Arsenide. Recent developments using epitaxially grown, strained Gallium Arsenide cathodes have made it possible to obtain electron polarization significantly in excess of the conventional 50% polarization limit. The basic principles for Gallium and Arsenide polarized photoemitters are reviewed, and the extension of the basic technique to strained cathode structures is described. Results from laboratory measurements of strained photocathodes as well as operational results from the SLAC polarized source are presented

  2. Polarized electron sources

    Energy Technology Data Exchange (ETDEWEB)

    Prepost, R. [Univ. of Wisconsin, Madison, WI (United States)

    1994-12-01

    The fundamentals of polarized electron sources are described with particular application to the Stanford Linear Accelerator Center. The SLAC polarized electron source is based on the principle of polarized photoemission from Gallium Arsenide. Recent developments using epitaxially grown, strained Gallium Arsenide cathodes have made it possible to obtain electron polarization significantly in excess of the conventional 50% polarization limit. The basic principles for Gallium and Arsenide polarized photoemitters are reviewed, and the extension of the basic technique to strained cathode structures is described. Results from laboratory measurements of strained photocathodes as well as operational results from the SLAC polarized source are presented.

  3. Influence of Meibomian Gland Expression Methods on Human Lipid Analysis Results.

    Science.gov (United States)

    Kunnen, Carolina M E; Brown, Simon H J; Lazon de la Jara, Percy; Holden, Brien A; Blanksby, Stephen J; Mitchell, Todd W; Papas, Eric B

    2016-01-01

    To compare the lipid composition of human meibum across three different meibum expression techniques. Meibum was collected from five healthy non-contact lens wearers (aged 20-35 years) after cleaning the eyelid margin using three meibum expression methods: cotton buds (CB), meibomian gland evaluator (MGE) and meibomian gland forceps (MGF). Meibum was also collected using cotton buds without cleaning the eyelid margin (CBn). Lipids were analyzed by chip-based, nano-electrospray mass spectrometry (ESI-MS). Comparisons were made using linear mixed models. Tandem MS enabled identification and quantification of over 200 lipid species across ten lipid classes. There were significant differences between collection techniques in the relative quantities of polar lipids obtained (P<.05). The MGE method returned smaller polar lipid quantities than the CB approaches. No significant differences were found between techniques for nonpolar lipids. No significant differences were found between cleaned and non-cleaned eyelids for polar or nonpolar lipids. Meibum expression technique influences the relative amount of phospholipids in the resulting sample. The highest amounts of phospholipids were detected with the CB approaches and the lowest with the MGE technique. Cleaning the eyelid margin prior to expression was not found to affect the lipid composition of the sample. This may be a consequence of the more forceful expression resulting in cell membrane contamination or higher risk of tear lipid contamination as a result of reflex tearing. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Do Lipids Retard the Evaporation of the Tear Fluid?

    DEFF Research Database (Denmark)

    Rantamaki, A. H.; Javanainen, M.; Vattulainen, I.

    2012-01-01

    phosphatidylcholine (PC), nonpolar cholesteryl ester, triglycerides, and wax ester (WE). Brewster angle microscopy (BAM) and interfacial shear rheometry (ISR) were used to assess the lateral structure and shear stress response of the lipid layers, respectively. RESULTS. Olive oil and long-chain alcohol decreased......PURPOSE. We examined in vitro the potential evaporation-retarding effect of the tear film lipid layer (TFLL). The artificial TFLL compositions used here were based on the present knowledge of TFLL composition. METHODS. A custom-built system was developed to measure evaporation rates at 35 degrees C....... Lipids were applied to an air-water interface, and the evaporation rate through the lipid layer was defined as water loss from the interface. A thick layer of olive oil and a monolayer of long-chain alcohol were used as controls. The artificial TFLLs were composed of 1 to 4 lipid species: polar...

  5. Polarized neutron spectrometer

    International Nuclear Information System (INIS)

    Abov, Yu.G.; Novitskij, V.V.; Alfimenkov, V.P.; Galinskij, E.M.; Mareev, Yu.D.; Pikel'ner, L.B.; Chernikov, A.N.; Lason', L.; Tsulaya, V.M.; Tsulaya, M.I.

    2000-01-01

    The polarized neutron spectrometer, intended for studying the interaction of polarized neutrons with nuclei and condensed media in the area of energies from thermal up to several electron-volt, is developed at the IBR-2 reactor (JINR, Dubna). Diffraction on the Co(92%)-Fe(8%) magnetized monocrystals is used for the neutron polarization and polarization analysis. The neutron polarization within the whole energy range equals ∼ 95% [ru

  6. Interaction of lysozyme with a tear film lipid layer model: A molecular dynamics simulation study.

    Science.gov (United States)

    Wizert, Alicja; Iskander, D Robert; Cwiklik, Lukasz

    2017-12-01

    The tear film is a thin multilayered structure covering the cornea. Its outermost layer is a lipid film underneath of which resides on an aqueous layer. This tear film lipid layer (TFLL) is itself a complex structure, formed by both polar and nonpolar lipids. It was recently suggested that due to tear film dynamics, TFLL contains inhomogeneities in the form of polar lipid aggregates. The aqueous phase of tear film contains lachrymal-origin proteins, whereby lysozyme is the most abundant. These proteins can alter TFLL properties, mainly by reducing its surface tension. However, a detailed nature of protein-lipid interactions in tear film is not known. We investigate the interactions of lysozyme with TFLL in molecular details by employing coarse-grained molecular dynamics simulations. We demonstrate that lysozyme, due to lateral restructuring of TFLL, is able to penetrate the tear lipid film embedded in inverse micellar aggregates. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Differential distribution of lipids in epidermis, gastrodermis and hosted Symbiodinium in the sea anemone Anemonia viridis.

    Science.gov (United States)

    Revel, Johana; Massi, Lionel; Mehiri, Mohamed; Boutoute, Marc; Mayzaud, Patrick; Capron, Laure; Sabourault, Cécile

    2016-01-01

    Cnidarian-dinoflagellate symbiosis mainly relies on nutrient recycling, thus providing both partners with a competitive advantage in nutrient-poor waters. Essential processes related to lipid metabolism can be influenced by various factors, including hyperthermal stress. This can affect the lipid content and distribution in both partners, while contributing to symbiosis disruption and bleaching. In order to gain further insight into the role and distribution of lipids in the cnidarian metabolism, we investigated the lipid composition of the sea anemone Anemonia viridis and its photosynthetic dinoflagellate endosymbionts (Symbiodinium). We compared the lipid content and fatty acid profiles of the host cellular layers, non-symbiotic epidermal and symbiont-containing gastrodermal cells, and those of Symbiodinium, in a mass spectrometry-based assessment. Lipids were more concentrated in Symbiodinium cells, and the lipid class distribution was dominated by polar lipids in all tissues. The fatty acid distribution between host cell layers and Symbiodinium cells suggested potential lipid transfers between the partners. The lipid composition and distribution was modified during short-term hyperthermal stress, mainly in Symbiodinium cells and gastrodermis. Exposure to elevated temperature rapidly caused a decrease in polar lipid C18 unsaturated fatty acids and a strong and rapid decrease in the abundance of polar lipid fatty acids relative to sterols. These lipid indicators could therefore be used as sensitive biomarkers to assess the physiology of symbiotic cnidarians, especially the effect of thermal stress at the onset of cnidarian bleaching. Overall, the findings of this study provide some insight on key lipids that may regulate maintenance of the symbiotic interaction. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Synthesis of novel cationic lipids with fully or partially non-scissile ...

    Indian Academy of Sciences (India)

    Unknown

    Cationic lipids are attracting a lot of current attention owing to their applications in gene therapy 1,2. The functional group that links the backbone bearing the polar head group with the hydrocarbon chains of these lipid molecules plays an important role in their utilization in gene transfer events. For instance, DOTMA, which ...

  9. Are lipid rafts involved in ABC transporter-mediated drug resistance of tumor cells?

    NARCIS (Netherlands)

    Kok, Jan Willem; Klappe, Karin; Hummel, Ina; Kroesen, Bart-Jan; Sietsma, Hannie; Meszaros, Peter

    2008-01-01

    Since their discovery, lipid rafts have been implicated in several cellular functions, including protein transport in polarized cells and signal transduction. Also in multidrug resistance lipid rafts may be important with regard to the localization of ATP-binding cassette (ABC) transporters in these

  10. Differentiation of strains of varicella-zoster virus by changes in neutral lipid metabolism in infected cells

    International Nuclear Information System (INIS)

    Jerkofsky, M.; De Siervo, A.J.

    1986-01-01

    Eleven isolates of varicella-zoster virus were tested for their effects on the incorporation of [ 14 C]acetate into lipids in infected human embryonic lung cells. By relative percent, all virus isolates demonstrated a shift from polar lipid synthesis to neutral lipid, especially triglyceride, synthesis. By data expressed as counts per minute per microgram of protein, the VZV strains could be separated into two groups: those strains which depressed lipid synthesis and those strains which did not depress, and may even have stimulated, lipid, especially triglyceride, synthesis. These results may be useful in understanding the development of lipid changes seen in children affected with Reye's syndrome following chickenpox

  11. Polarized targets and beams

    International Nuclear Information System (INIS)

    Meyer, W.

    1985-01-01

    First the experimental situation of the single-pion photoproduction and the photodisintegration of the deuteron is briefly discussed. Then a description of the Bonn polarization facilities is given. The point of main effort is put on the polarized target which plays a vital role in the program. A facility for photon induced double polarization experiments at ELSA will be presented in section 4. Properties of a tensor polarized deuteron target are discussed in section 5. The development in the field of polarized targets, especially on new target materials, enables a new generation of polarized target experiments with (polarized) electrons. Some comments on the use of a polarized target in combination with electron beams will be discussed in section 6. Electron deuteron scattering from a tensor polarized deuteron target is considered and compared with other experimental possibilities. (orig./HSI)

  12. Properties of An Oral Nanoformulation of A Molecularly Dispersed Amphotericin B Comprising A Composite Matrix of Theobroma Oil and Bee’S Wax

    Directory of Open Access Journals (Sweden)

    Chloe See Wei Tan

    2014-12-01

    Full Text Available An amphotericin B-containing (AmB solid lipid nanoparticulate drug delivery system intended for oral administration, comprised of bee’s wax and theobroma oil as lipid components was formulated with the aim to ascertain the location of AmB within the lipid matrix: (a a homogenous matrix; (b a drug-enriched shell; or (c a drug enriched core. Both the drug-loaded and drug-free nanoparticles were spherical with AmB contributing to an increase in both the z-average diameter (169 ± 1 to 222 ± 2 nm and zeta potential (40.8 ± 0.9 to 50.3 ± 1.0 mV of the nanoparticles. A maximum encapsulation efficiency of 21.4% ± 3.0%, corresponding to 10.7 ± 0.4 mg encapsulated AmB within the lipid matrix was observed. Surface analysis and electron microscopic imaging indicated that AmB was dispersed uniformly within the lipid matrix (option (a above and, therefore, this is the most suitable of the three models with regard to modeling the propensity for uptake by epithelia and release of AmB in lymph.

  13. Polyene-lipids: a new tool to image lipids

    DEFF Research Database (Denmark)

    Kuerschner, Lars; Ejsing, Christer S.; Ekroos, Kim

    2005-01-01

    conjugated double bonds as a new type of lipid tag. Polyene-lipids exhibit a unique structural similarity to natural lipids, which results in minimal effects on the lipid properties. Analyzing membrane phase partitioning, an important biophysical and biological property of lipids, we demonstrated......Microscopy of lipids in living cells is currently hampered by a lack of adequate fluorescent tags. The most frequently used tags, NBD and BODIPY, strongly influence the properties of lipids, yielding analogs with quite different characteristics. Here, we introduce polyene-lipids containing five...... the superiority of polyene-lipids to both NBD- and BODIPY-tagged lipids. Cells readily take up various polyene-lipid precursors and generate the expected end products with no apparent disturbance by the tag. Applying two-photon excitation microscopy, we imaged the distribution of polyene-lipids in living...

  14. The evolution of lipids

    Science.gov (United States)

    Itoh, Y. H.; Sugai, A.; Uda, I.; Itoh, T.

    2001-01-01

    Living organisms on the Earth which are divided into three major domains - Archaea, Bacteria, and Eucarya, probably came from a common ancestral cell. Because there are many thermophilic microorganisms near the root of the universal phylogenetic tree, the common ancestral cell should be considered to be a thermophilic microorganism. The existence of a cell is necessary for the living organisms; the cell membrane is the essential structural component of a cell, so its amphiphilic property is vital for the molecule of lipids for cell membranes. Tetraether type glycerophospholipids with C 40 isoprenoid chains are major membrane lipids widely distributed in archaeal cells. Cyclization number of C 40 isoprenoid chains in thermophilic archaea influences the fluidity of lipids whereas the number of carbons and degree of unsaturation in fatty acids do so in bacteria and eucarya. In addition to the cyclization of the tetraether lipids, covalent bonding of two C 40 isoprenoid chains was found in hyperthermophiles. These characteristic structures of the lipids seem to contribute to their fundamental physiological roles in hyperthermophiles. Stereochemical differences between G-1-P archaeal lipids and G-3-P bacterial and eucaryal lipids might have occured by the function of some proteins long after the first cell was developed by the reactions of small organic molecules. We propose that the structure of lipids of the common ancestral cell may have been similar to those of hyperthermophilic archaea.

  15. Lysosomal lipid storage diseases.

    Science.gov (United States)

    Schulze, Heike; Sandhoff, Konrad

    2011-06-01

    Lysosomal lipid storage diseases, or lipidoses, are inherited metabolic disorders in which typically lipids accumulate in cells and tissues. Complex lipids, such as glycosphingolipids, are constitutively degraded within the endolysosomal system by soluble hydrolytic enzymes with the help of lipid binding proteins in a sequential manner. Because of a functionally impaired hydrolase or auxiliary protein, their lipid substrates cannot be degraded, accumulate in the lysosome, and slowly spread to other intracellular membranes. In Niemann-Pick type C disease, cholesterol transport is impaired and unesterified cholesterol accumulates in the late endosome. In most lysosomal lipid storage diseases, the accumulation of one or few lipids leads to the coprecipitation of other hydrophobic substances in the endolysosomal system, such as lipids and proteins, causing a "traffic jam." This can impair lysosomal function, such as delivery of nutrients through the endolysosomal system, leading to a state of cellular starvation. Therapeutic approaches are currently restricted to mild forms of diseases with significant residual catabolic activities and without brain involvement.

  16. Lipid bilayers and interfaces

    NARCIS (Netherlands)

    Kik, R.A.

    2007-01-01

    In biological systems lipid bilayers are subject to many different interactions with other entities. These can range from proteins that are attached to the hydrophilic region of the bilayer or transmembrane proteins that interact with the hydrophobic region of the lipid bilayer. Interaction between

  17. The obtaining of iron acetate from processed iron comprising catalyst of ammonia synthesis

    International Nuclear Information System (INIS)

    Mansurov, M.M.; Lugovenko, A.N.; Mirzoeva, M.M.

    1993-01-01

    Present article is devoted to obtaining of iron acetate from processed iron comprising catalyst of ammonia synthesis. The method of synthesis of iron acetate from processed iron comprising catalyst of ammonia synthesis was elaborated. The structure of complex was determined.

  18. Production of lipids in 10 strains of Chlorella and Parachlorella, and enhanced lipid productivity in Chlorella vulgaris

    Energy Technology Data Exchange (ETDEWEB)

    Pribyl, Pavel; Cepak, Vladislav [Academy of Sciences of the Czech Republic, Trebon (Czech Republic). Algological Centre and Centre for Bioindication and Revitalization; Zachleder, Vilem [Academy of Sciences of the Czech Republic, Trebon (Czech Republic). Lab. of the Cell Cycles of Algae

    2012-04-15

    We tested 10 different Chlorella and Parachlorella strains under lipid induction growth conditions in autotrophic laboratory cultures. Between tested strains, substantial differences in both biomass and lipid productivity as well as in the final content of lipids were found. The most productive strain (Chlorella vulgaris CCALA 256) was subsequently studied in detail. The availability of nitrates and/or phosphates strongly influenced growth and accumulation of lipids in cells by affecting cell division. Nutrient limitation substantially enhanced lipid productivity up to a maximal value of 1.5 g l{sup -1} day{sup -1}. We also demonstrated the production of lipids through large-scale cultivation of C. vulgaris in a thin layer photobioreactor, even under suboptimal conditions. After 8 days of cultivation, maximal lipid productivity was 0.33 g l{sup -1} day{sup -1}, biomass density was 5.7 g l{sup -1} dry weight and total lipid content was more than 30% dry weight. C. vulgaris lipids comprise fatty acids with a relatively high degree of saturation compared with canola oil offering a possible alternative to the use of higher plant oils. (orig.)

  19. Scattering with polarized neutrons

    International Nuclear Information System (INIS)

    Schweizer, J.

    2007-01-01

    In the history of neutron scattering, it was shown very soon that the use of polarized neutron beams brings much more information than usual scattering with unpolarized neutrons. We shall develop here the different scattering methods that imply polarized neutrons: 1) polarized beams without polarization analysis, the flipping ratio method; 2) polarized beams with a uniaxial polarization analysis; 3) polarized beams with a spherical polarization analysis. For all these scattering methods, we shall give examples of the physical problems which can been solved by these methods, particularly in the field of magnetism: investigation of complex magnetic structures, investigation of spin or magnetization densities in metals, insulators and molecular compounds, separation of magnetic and nuclear scattering, investigation of magnetic properties of liquids and amorphous materials and even, for non magnetic material, separation between coherent and incoherent scattering. (author)

  20. Polarized Light Corridor Demonstrations.

    Science.gov (United States)

    Davies, G. R.

    1990-01-01

    Eleven demonstrations of light polarization are presented. Each includes a brief description of the apparatus and the effect demonstrated. Illustrated are strain patterns, reflection, scattering, the Faraday Effect, interference, double refraction, the polarizing microscope, and optical activity. (CW)

  1. Pneumatic stepper motor and device comprising at least one such pneumatic stepper motor

    NARCIS (Netherlands)

    Groenhuis, Vincent; Siepel, Françoise Jeanette; Stramigioli, Stefano

    2018-01-01

    The invention relates to a pneumatic stepper motor, comprising: - a housing, said housing accommodating at least part of: - a rack or geared axle comprising a plurality of gear elements; and - two pistons, each comprising at least two teeth, said pistons being arranged to cooperate with said rack or

  2. Effects of cadmium on lipids of almond seedlings (Prunus dulcis).

    Science.gov (United States)

    Elloumi, Nada; Zouari, Mohamed; Chaari, Leila; Jomni, Chiraz; Marzouk, Brahim; Ben Abdallah, Ferjani

    2014-12-01

    Cadmium uptake and distribution, as well as its effects on lipid composition was investigated in almond seedlings (Prunus dulcis) grown in culture solution supplied with two concentrations of Cd (50 and 150 μM). The accumulation of Cd increased with external metal concentrations, and was considerably higher in roots than in leaves. Fourteen days after Cd treatment, the membrane lipids were extracted and separated on silica-gel thin layer chromatography (TLC). Fatty acid methyl esters were analyzed by FID-GC on a capillary column. Our results showed that Cd stress decreased the quantities of all lipids classes (phospholipids, galactolipids and neutral lipids). Galactolipid, phospholipid and neutral lipid concentrations decreased more in roots than in leaves by Cd-treatment. In almost all lipid classes the proportion of palmitic acid (16:0), linoleic (18: 2) and that of linolenic (18: 3) acid decreased, suggesting that heavy metal treatment induced an alteration in the fatty acid synthesis processes. In conclusion, our results show that the changes found in total fatty acids, in the quantities of all lipids classes, and in the in the profiles of individual polar lipids suggest that membrane structure and function might be altered by Cd stress.

  3. Techniques in polarization physics

    International Nuclear Information System (INIS)

    Clausnitzer, G.

    1974-01-01

    A review of the current status of the technical tools necessary to perform different kinds of polarization experiments is presented, and the absolute and relative accuracy with which data can be obtained is discussed. A description of polarized targets and sources of polarized fast neutrons is included. Applications of polarization techniques to other fields is mentioned briefly. (14 figures, 3 tables, 110 references) (U.S.)

  4. High frequency nonlinear scattering from a micrometer to submicrometer sized lipid encapsulated contrast agent

    NARCIS (Netherlands)

    Goertz, David E.; Frijlink, Martijn E.; de Jong, N.; van der Steen, A.F.W.

    2006-01-01

    An experimental lipid encapsulated contrast agent comprised substantially of micrometer to submicrometer diameter bubbles was evaluated for its capacity to produce nonlinear scattering in response to high transmit frequencies. Agent characterization experiments were conducted at transmit frequencies

  5. Regional differences in the lateral mobility of plasma membrane lipids in a molluscan embryo

    OpenAIRE

    Speksnijder, J.E.; Dohmen, M.R.; Tertoolen, L.G.J.; Laat, S.W. de

    1985-01-01

    Regional and temporal differences in plasma membrane lipid mobility have been analyzed during the first three cleavage cycles of the embryo of the polar-lobe-forming mollusc Nassarius reticulatus by the fluorescence photobleaching recovery (FPR) method, using 1,1′-ditetradecyl 3,3,3′,3′-tetramethylindocarbocyanine iodide (C14diI) as a fluorescent lipid probe. During this period of development the lateral diffusion coefficient of membrane lipids is consistently greater in the vegetal polar lob...

  6. Polarized Moessbauer transitions

    International Nuclear Information System (INIS)

    Barb, D.

    1975-01-01

    Theoretical aspects of the emission, absorption and scattering of polarized gamma rays are reviewed for a general case of combined magnetic and electric hyperfine interactions; various possibilities of obtaining polarized gamma sources are described and examples are given of the applications of Moessbauer spectroscopy with polarized gamma rays in solving problems of solid state physics. (A.K.)

  7. Geographical Income Polarization

    DEFF Research Database (Denmark)

    Azhar, Hussain; Jonassen, Anders Bruun

    inter municipal income inequality. Counter factual simulations show that rising property prices to a large part explain the rise in polarization. One side-effect of polarization is tendencies towards a parallel polarization of residence location patterns, where low skilled individuals tend to live...

  8. Calculation of polarization effects

    International Nuclear Information System (INIS)

    Chao, A.W.

    1983-09-01

    Basically there are two areas of accelerator applications that involve beam polarization. One is the acceleration of a polarized beam (most likely a proton beam) in a synchrotron. Another concerns polarized beams in an electron storage ring. In both areas, numerical techniques have been very useful

  9. Avanti lipid tools: connecting lipids, technology, and cell biology.

    Science.gov (United States)

    Sims, Kacee H; Tytler, Ewan M; Tipton, John; Hill, Kasey L; Burgess, Stephen W; Shaw, Walter A

    2014-08-01

    Lipid research is challenging owing to the complexity and diversity of the lipidome. Here we review a set of experimental tools developed for the seasoned lipid researcher, as well as, those who are new to the field of lipid research. Novel tools for probing protein-lipid interactions, applications for lipid binding antibodies, enhanced systems for the cellular delivery of lipids, improved visualization of lipid membranes using gold-labeled lipids, and advances in mass spectrometric analysis techniques will be discussed. Because lipid mediators are known to participate in a host of signal transduction and trafficking pathways within the cell, a comprehensive lipid toolbox that aids the science of lipidomics research is essential to better understand the molecular mechanisms of interactions between cellular components. This article is part of a Special Issue entitled Tools to study lipid functions. Copyright © 2014. Published by Elsevier B.V.

  10. Molecularly oriented surface relief formation in polymethacrylates comprising N-benzylideneaniline derivative side groups

    Science.gov (United States)

    Kawatsuki, Nobuhiro; Hosoda, Risa; Kondo, Mizuho; Sasaki, Tomoyuki; Ono, Hiroshi

    2014-12-01

    Molecularly oriented surface relief (SR) formation in polymethacrylates with N-benzylideneaniline (NBA) derivative side groups is investigated by holographic exposure using a 325 nm He-Cd laser. Because the NBA moieties show a photoinduced orientation perpendicular to the polarization of light, polarization holography successfully forms a molecularly oriented SR structure in accordance with the polarization distribution that includes p-polarized components. Although intensity holography induces molecular orientation, it does not generate a satisfactory SR structure. In all the holographic modes, the SR depth depends on the direction of the C=N bonds in the NBA moieties and the photoproducts affect the SR formation ability.

  11. Synthesis of Lipidated Proteins.

    Science.gov (United States)

    Mejuch, Tom; Waldmann, Herbert

    2016-08-17

    Protein lipidation is one of the major post-translational modifications (PTM) of proteins. The attachment of the lipid moiety frequently determines the localization and the function of the lipoproteins. Lipidated proteins participate in many essential biological processes in eukaryotic cells, including vesicular trafficking, signal transduction, and regulation of the immune response. Malfunction of these cellular processes usually leads to various diseases such as cancer. Understanding the mechanism of cellular signaling and identifying the protein-protein and protein-lipid interactions in which the lipoproteins are involved is a crucial task. To achieve these goals, fully functional lipidated proteins are required. However, access to lipoproteins by means of standard expression is often rather limited. Therefore, semisynthetic methods, involving the synthesis of lipidated peptides and their subsequent chemoselective ligation to yield full-length lipoproteins, were developed. In this Review we summarize the commonly used methods for lipoprotein synthesis and the development of the corresponding chemoselective ligation techniques. Several key studies involving full-length semisynthetic lipidated Ras, Rheb, and LC3 proteins are presented.

  12. Spin Coulomb Dragging Inhibition of Spin-Polarized Electric Current Injecting into Organic Semiconductors

    International Nuclear Information System (INIS)

    Jun-Qing, Zhao; Shi-Zhu, Qiao; Zhen-Feng, Jia; Ning-Yu, Zhang; Yan-Ju, Ji; Yan-Tao, Pang; Ying, Chen; Gang, Fu

    2008-01-01

    We introduce a one-dimensional spin injection structure comprising a ferromagnetic metal and a nondegenerate organic semiconductor to model electric current polarizations. With this model we analyse spin Coulomb dragging (SCD) effects on the polarization under various electric fields, interface and conductivity conditions. The results show that the SCD inhibits the current polarization. Thus the SCD inhibition should be well considered for accurate evaluation of current polarization in the design of organic spin devices

  13. Lipid vesicle-mediated affinity chromatography using magnetic activated cell sorting (LIMACS): a novel method to analyze protein-lipid interaction.

    Science.gov (United States)

    Bieberich, Erhard

    2011-04-26

    The analysis of lipid protein interaction is difficult because lipids are embedded in cell membranes and therefore, inaccessible to most purification procedures. As an alternative, lipids can be coated on flat surfaces as used for lipid ELISA and Plasmon resonance spectroscopy. However, surface coating lipids do not form microdomain structures, which may be important for the lipid binding properties. Further, these methods do not allow for the purification of larger amounts of proteins binding to their target lipids. To overcome these limitations of testing lipid protein interaction and to purify lipid binding proteins we developed a novel method termed lipid vesicle-mediated affinity chromatography using magnetic-activated cell sorting (LIMACS). In this method, lipid vesicles are prepared with the target lipid and phosphatidylserine as the anchor lipid for Annexin V MACS. Phosphatidylserine is a ubiquitous cell membrane phospholipid that shows high affinity to the protein Annexin V. Using magnetic beads conjugated to Annexin V the phosphatidylserine-containing lipid vesicles will bind to the magnetic beads. When the lipid vesicles are incubated with a cell lysate the protein binding to the target lipid will also be bound to the beads and can be co-purified using MACS. This method can also be used to test if recombinant proteins reconstitute a protein complex binding to the target lipid. We have used this method to show the interaction of atypical PKC (aPKC) with the sphingolipid ceramide and to co-purify prostate apoptosis response 4 (PAR-4), a protein binding to ceramide-associated aPKC. We have also used this method for the reconstitution of a ceramide-associated complex of recombinant aPKC with the cell polarity-related proteins Par6 and Cdc42. Since lipid vesicles can be prepared with a variety of sphingo- or phospholipids, LIMACS offers a versatile test for lipid-protein interaction in a lipid environment that resembles closely that of the cell membrane

  14. Acceleration of polarized particles

    International Nuclear Information System (INIS)

    Buon, J.

    1992-05-01

    The spin kinetics of polarized beams in circular accelerators is reviewed in the case of spin-1/2 particles (electrons and protons) with emphasis on the depolarization phenomena. The acceleration of polarized proton beams in synchrotrons is described together with the cures applied to reduce depolarization, including the use of 'Siberian Snakes'. The in-situ polarization of electrons in storage rings due to synchrotron radiation is studied as well as depolarization in presence of ring imperfections. The applications of electron polarization to accurately calibrate the rings in energy and to use polarized beams in colliding-beam experiments are reviewed. (author) 76 refs., 19 figs., 1 tab

  15. Adiabatic/diabatic polarization beam splitter

    Energy Technology Data Exchange (ETDEWEB)

    DeRose, Christopher; Cai, Hong

    2017-09-12

    The various presented herein relate to an on-chip polarization beam splitter (PBS), which is adiabatic for the transverse magnetic (TM) mode and diabatic for the transverse electric (TE) mode. The PBS comprises a through waveguide and a cross waveguide, wherein an electromagnetic beam comprising TE mode and TM mode components is applied to an input port of the through waveguide. The PBS can be utilized to separate the TE mode component from the TM mode component, wherein the TE mode component exits the PBS via an output port of the through waveguide, and the TM mode component exits the PBS via an output port of the cross waveguide. The PBS has a structure that is tolerant to manufacturing variations and exhibits high polarization extinction ratios over a wide bandwidth.

  16. Perspectives on marine zooplankton lipids

    DEFF Research Database (Denmark)

    Kattner, G.; Hagen, W.; Lee, R.F.

    2007-01-01

    We developed new perspectives to identify important questions and to propose approaches for future research on marine food web lipids. They were related to (i) structure and function of lipids, (ii) lipid changes during critical life phases, (iii) trophic marker lipids, and (iv) potential impact...... of climate change. The first addresses the role of lipids in membranes, storage lipids, and buoyancy with the following key question: How are the properties of membranes and deposits affected by the various types of lipids? The second deals with the importance of various types of lipids during reproduction......, development, and resting phases and addresses the role of the different storage lipids during growth and dormancy. The third relates to trophic marker lipids, which are an important tool to follow lipid and energy transfer through the food web. The central question is how can fatty acids be used to identify...

  17. Polarization effects. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Courant, E.

    1981-01-01

    The use of polarized proton beams in ISABELLE is important for several general reasons: (1) With a single longitudinally polarized proton beam, effects involving parity violation can be identified and hence processes involving weak interactions can be separated from those involving strong and electromagnetic interactions. (2) Spin effects are important in the strong interactions and can be useful for testing QCD. The technique for obtaining polarized proton beams in ISABELLE appears promising, particularly in view of the present development of a polarized proton beam for the AGS. Projections for the luminosity in ISABELLE for collisions of polarized protons - one or both beams polarized with longitudinal or transverse polarization - range from 1/100 to 1 times the luminosity for unpolarized protons.

  18. The Physics of Polarization

    Science.gov (United States)

    Landi Degl'Innocenti, Egidio

    2015-10-01

    The introductory lecture that has been delivered at this Symposium is a condensed version of an extended course held by the author at the XII Canary Island Winter School from November 13 to November 21, 2000. The full series of lectures can be found in Landi Degl'Innocenti (2002). The original reference is organized in 20 Sections that are here itemized: 1. Introduction, 2. Description of polarized radiation, 3. Polarization and optical devices: Jones calculus and Muller matrices, 4. The Fresnel equations, 5. Dichroism and anomalous dispersion, 6. Polarization in everyday life, 7. Polarization due to radiating charges, 8. The linear antenna, 9. Thomson scattering, 10. Rayleigh scattering, 11. A digression on Mie scattering, 12. Bremsstrahlung radiation, 13. Cyclotron radiation, 14. Synchrotron radiation, 15. Polarization in spectral lines, 16. Density matrix and atomic polarization, 17. Radiative transfer and statistical equilibrium equations, 18. The amplification condition in polarized radiative transfer, and 19. Coupling radiative transfer and statistical equilibrium equations.

  19. Changes in blood glucose and plasma lipids during gestation in ...

    African Journals Online (AJOL)

    Ten female Chinchilla rabbits with mean weight (1.9±0.1kg) were randomly assigned into two groups comprising of five each, to evaluate the changes in blood glucose and lipid profile during pregnancy. Control Group A was mated without prior synchronization, while rabbits in group B were synchronized with 0.15mg/kg ...

  20. Exploring ancient microbial community assemblages by creating complex lipid biomarker profiles for stromatolites and microbial mats in Hamelin Pool, Shark Bay, Australia

    Science.gov (United States)

    Myers, E.; Summons, R. E.; Schubotz, F.; Matys, E. D.

    2015-12-01

    Stromatolites that are biogenic in origin, a characteristic that can be determined by the coexistence of microbial mats (active microbial communities) and stromatolites (lithified structures) like in Hamelin Pool, comprise one of the best modern analogs to ancient microbial community assemblages. Comprehensive lipid biomarker profiles that include lipids of varying persistence in the rock record can help determine how previously living microbial communities are represented in lithified stromatolites. To create these profiles, the samples analyzed included non-lithified smooth, pustular, and colloform microbial mats, as well as smooth and colloform stromatolites. Select samples were separated into upper and lower layers of 5cm depth each. Intact polar lipids, glycerol dialkyl glycerol tetraethers, and bacteriohopanepolyols were analyzed via liquid chromatography-mass spectrometry (LC-MS) coupled to a Quadropole Time-of-Flight (QTOF) mass spectrometer; additionally, fatty acids from each sample were analyzed using gas chromatography-mass spectrometry (GC-MS) to prove consistent signatures with those determined by Allen et al. in 2010 for similar microbial mat samples. In accordance with those findings, 2-methylhopanoids were detected, as well as limited signals from higher (vascular) plants, the latter of which suggests terrestrial inputs, potentially from runoff. The rarely detected presence of 3-methylhopanoids appears in a significant portion of the samples, though further isolations of the molecule are needed to confirm. While all lipid profiles were relatively similar, certain differences in relative composition are likely attributable to morphological differences of the mats, some of which allow deeper oxygen and/or sunlight penetration, which influence the microbial community. However, overall similarities of transient and persistent lipids suggest that the microbial communities of both the non-lithified microbial mats and stromatolites are similar.

  1. Symbiodinium genotypic and environmental controls on lipids in reef building corals.

    Directory of Open Access Journals (Sweden)

    Timothy F Cooper

    Full Text Available BACKGROUND: Lipids in reef building corals can be divided into two classes; non-polar storage lipids, e.g. wax esters and triglycerides, and polar structural lipids, e.g. phospholipids and cholesterol. Differences among algal endosymbiont types are known to have important influences on processes including growth and the photobiology of scleractinian corals yet very little is known about the role of symbiont types on lipid energy reserves. METHODOLOGY/PRINCIPAL FINDINGS: The ratio of storage lipid and structural lipid fractions of Scott Reef corals were determined by thin layer chromatography. The lipid fraction ratio varied with depth and depended on symbiont type harboured by two corals (Seriatopora hystrix and Pachyseris speciosa. S. hystrix colonies associated with Symbiodinium C1 or C1/C# at deep depths (>23 m had lower lipid fraction ratios (i.e. approximately equal parts of storage and structural lipids than those with Symbiodinium D1 in shallow depths (<23 m, which had higher lipid fraction ratios (i.e. approximately double amounts of storage relative to structural lipid. Further, there was a non-linear relationship between the lipid fraction ratio and depth for S. hystrix with a modal peak at ∼23 m coinciding with the same depth as the shift from clade D to C types. In contrast, the proportional relationship between the lipid fraction ratio and depth for P. speciosa, which exhibited high specificity for Symbiodinium C3 like across the depth gradient, was indicative of greater amounts of storage lipids contained in the deep colonies. CONCLUSIONS/SIGNIFICANCE: This study has demonstrated that Symbiodinium exert significant controls over the quality of coral energy reserves over a large-scale depth gradient. We conclude that the competitive advantages and metabolic costs that arise from flexible associations with divergent symbiont types are offset by energetic trade-offs for the coral host.

  2. Acyl-Lipid Metabolism

    Science.gov (United States)

    Li-Beisson, Yonghua; Shorrosh, Basil; Beisson, Fred; Andersson, Mats X.; Arondel, Vincent; Bates, Philip D.; Baud, Sébastien; Bird, David; DeBono, Allan; Durrett, Timothy P.; Franke, Rochus B.; Graham, Ian A.; Katayama, Kenta; Kelly, Amélie A.; Larson, Tony; Markham, Jonathan E.; Miquel, Martine; Molina, Isabel; Nishida, Ikuo; Rowland, Owen; Samuels, Lacey; Schmid, Katherine M.; Wada, Hajime; Welti, Ruth; Xu, Changcheng; Zallot, Rémi; Ohlrogge, John

    2013-01-01

    Acyl lipids in Arabidopsis and all other plants have a myriad of diverse functions. These include providing the core diffusion barrier of the membranes that separates cells and subcellular organelles. This function alone involves more than 10 membrane lipid classes, including the phospholipids, galactolipids, and sphingolipids, and within each class the variations in acyl chain composition expand the number of structures to several hundred possible molecular species. Acyl lipids in the form of triacylglycerol account for 35% of the weight of Arabidopsis seeds and represent their major form of carbon and energy storage. A layer of cutin and cuticular waxes that restricts the loss of water and provides protection from invasions by pathogens and other stresses covers the entire aerial surface of Arabidopsis. Similar functions are provided by suberin and its associated waxes that are localized in roots, seed coats, and abscission zones and are produced in response to wounding. This chapter focuses on the metabolic pathways that are associated with the biosynthesis and degradation of the acyl lipids mentioned above. These pathways, enzymes, and genes are also presented in detail in an associated website (ARALIP: http://aralip.plantbiology.msu.edu/). Protocols and methods used for analysis of Arabidopsis lipids are provided. Finally, a detailed summary of the composition of Arabidopsis lipids is provided in three figures and 15 tables. PMID:23505340

  3. Workshop on polarized neutron filters and polarized pulsed neutron experiments

    International Nuclear Information System (INIS)

    Itoh, Shinichi

    2004-07-01

    The workshop was held in KEK by thirty-three participants on April 26, 2004. The polarized neutron filter method was only discussed. It consists of three parts; the first part was discussed on the polarized neutron methods, the second part on the polarized neutron experiments and the third on the pulse neutron spectrometer and polarized neutron experiments. The six papers were presented such as the polarized 3 He neutron spin filter, neutron polarization by proton polarized filter, soft master and neutron scattering, polarized neutron in solid physics, polarization experiments by chopper spectroscope and neutron polarization system in superHRPD. (S.Y.)

  4. Design and Synthesis of Archaea-Inspired Tetraether Lipids

    Science.gov (United States)

    Koyanagi, Takaoki

    Maintaining the correct ion homeostasis across membranes is a major challenge in both nature and artificial systems. Archaea, have evolved to solve membrane permeability problems to survive in extreme environments by incorporating unique structural features found in their lipid. Specifically, inclusion of phytanyl side chains, ether glycerol linkages, tethering of lipids, cycloalkanes, and different polar lipid headgroups into their lipid membrane are believed to contribute to membrane stability. We sought to gain a better understanding of the functional benefits attributed to these structural features to membrane stability to design a new class of synthetic Archaea inspired lipid membranes that can be used to overcome limitations (i.e. unstable in serum environment, high background leakage, and prone to hydrolysis) found in current lipid based technologies. Leakage experiments revealed liposomes made from GMGTPC (glycerol monoalkyl glycerol tetraether lipid with phosphatidylcholine headgroup) demonstrated a two order magnitude reduction in membrane leakage to small ions when compared with liposomes made from EggPC. Additionally, liposomes composed of GMGTPC-CH (cyclohexane integrated) lipid displayed an additional 40% decrease in membrane leakage to small ions when compared with liposomes made from GMGTPC lipids. Furthermore, leakage experiments revealed a higher degree of tolerance to headgroup modifications to membrane leakage for liposomes made from GMGT lipid analogs when compared with liposomes made from POPC. After designing an optimal tetraether lipid scaffold that incorporates key Archaeal structural features for membrane leakage, we explored to integrate strategies employed by eukaryotes to improve membrane properties (i.e. addition of cholesterol). Liposomes made from the hybrid lipid, GcGTPC-CH, displayed a five-fold decrease in membrane leakage when compared with liposomes made from GMGTPC-CH, while maintaining functional membrane properties similar to

  5. Instrumentation with polarized neutrons

    International Nuclear Information System (INIS)

    Boeni, P.; Muenzer, W.; Ostermann, A.

    2009-01-01

    Neutron scattering with polarization analysis is an indispensable tool for the investigation of novel materials exhibiting electronic, magnetic, and orbital degrees of freedom. In addition, polarized neutrons are necessary for neutron spin precession techniques that path the way to obtain extremely high resolution in space and time. Last but not least, polarized neutrons are being used for fundamental studies as well as very recently for neutron imaging. Many years ago, neutron beam lines were simply adapted for polarized beam applications by adding polarizing elements leading usually to unacceptable losses in neutron intensity. Recently, an increasing number of beam lines are designed such that an optimum use of polarized neutrons is facilitated. In addition, marked progress has been obtained in the technology of 3 He polarizers and the reflectivity of large-m supermirrors. Therefore, if properly designed, only factors of approximately 2-3 in neutron intensity are lost. It is shown that S-benders provide neutron beams with an almost wavelength independent polarization. Using twin cavities, polarized beams with a homogeneous phase space and P>0.99 can be produced without significantly sacrificing intensity. It is argued that elliptic guides, which are coated with large m polarizing supermirrors, provide the highest flux.

  6. Lipid rafts and B cell signaling.

    Science.gov (United States)

    Gupta, Neetu; DeFranco, Anthony L

    2007-10-01

    B cells comprise an essential component of the humoral immune system. They are equipped with the unique ability to synthesize and secrete pathogen-neutralizing antibodies, and share with professional antigen presenting cells the ability to internalize foreign antigens, and process them for presentation to helper T cells. Recent evidence indicates that specialized cholesterol- and glycosphingolipid-rich microdomains in the plasma membrane commonly referred to as lipid rafts, serve to compartmentalize key signaling molecules during the different stages of B cell activation including B cell antigen receptor (BCR)-initiated signal transduction, endocytosis of BCR-antigen complexes, loading of antigenic peptides onto MHC class II molecules, MHC-II associated antigen presentation to helper T cells, and receipt of helper signals via the CD40 receptor. Here we review the recent literature arguing for a role of lipid rafts in the spatial organization of B cell function.

  7. Lipid class and fatty acid composition of a little-known and rarely collected alga Exophyllum wentii Weber-van Bosse from Bali Island, Indonesia.

    Science.gov (United States)

    Illijas, Muhammad I; Indy, Jeane R; Yasui, Hajime; Itabashi, Yutaka

    2009-01-01

    The lipid class and fatty acid composition of a little-known and rarely collected alga Exophyllum wentii from Bali Island, Indonesia were determined for fresh and frozen-thawed samples using thin-layer chromatography, gas-liquid chromatography, and high-performance liquid chromatography. Glycoglycerolipids, which mainly consisted of mongalactosyldiacylglycerols (MGDG) and digalactosyldiacylglycerols (DGDG), were the predominant lipid components, accounting for 67% and 56% of the total polar lipid content in the fresh and frozen-thawed samples, respectively. Phospholipids, including phosphatidylcholines (PC) and phosphatidylglycerols (PG), were detected with lesser amounts in both samples (16-17% of the total polar lipid content). Free fatty acids (FFA), sterols and triacylglycerols (TAG) were also detected in minor quantities; however, the FFA content in the frozen-thawed sample increased to up to 20% of the total lipid content, suggesting that hydrolysis of the membrane lipids had occurred. A crude enzyme preparation from the alga showed activities for hydrolyzing the acyl groups of the phospholipids and glycoglycerolipids. Palmitic acid (16:0) and arachidonic acid (20:4n-6) were the major fatty acids in both the total lipid and in individual polar lipid classes as well as the dominant fatty acids released from the membrane lipids by enzymatic hydrolysis. The high level of 20:4n-6 (29%) in the total lipid and the presence of considerable amounts of PC (11% of the total polar lipid) and PG (6.2%) support classification of E. wentii into the Division Rhodophyta.

  8. Evaluation of Extraction Protocols for Simultaneous Polar and Non-Polar Yeast Metabolite Analysis Using Multivariate Projection Methods

    Directory of Open Access Journals (Sweden)

    Nicolas P. Tambellini

    2013-07-01

    Full Text Available Metabolomic and lipidomic approaches aim to measure metabolites or lipids in the cell. Metabolite extraction is a key step in obtaining useful and reliable data for successful metabolite studies. Significant efforts have been made to identify the optimal extraction protocol for various platforms and biological systems, for both polar and non-polar metabolites. Here we report an approach utilizing chemoinformatics for systematic comparison of protocols to extract both from a single sample of the model yeast organism Saccharomyces cerevisiae. Three chloroform/methanol/water partitioning based extraction protocols found in literature were evaluated for their effectiveness at reproducibly extracting both polar and non-polar metabolites. Fatty acid methyl esters and methoxyamine/trimethylsilyl derivatized aqueous compounds were analyzed by gas chromatography mass spectrometry to evaluate non-polar or polar metabolite analysis. The comparative breadth and amount of recovered metabolites was evaluated using multivariate projection methods. This approach identified an optimal protocol consisting of 64 identified polar metabolites from 105 ion hits and 12 fatty acids recovered, and will potentially attenuate the error and variation associated with combining metabolite profiles from different samples for untargeted analysis with both polar and non-polar analytes. It also confirmed the value of using multivariate projection methods to compare established extraction protocols.

  9. Multiphoton polarization Bremsstrahlung effect

    International Nuclear Information System (INIS)

    Golovinskij, P.A.

    2001-01-01

    A general approach to induced polarization effects was formulated on the basis of theory of many particles in a strong periodic field. Correlation with the perturbation theory is shown and the types of effective polarization potentials both for isolated atoms and ions, and for ions in plasma, are provided. State of art in the theory of forced polarization Bremsstrahlung effect is analyzed and some outlooks for further experimental and theoretical studies are outlined [ru

  10. Factors influencing particulate lipid production in the East Atlantic Ocean

    Science.gov (United States)

    Gašparović, B.; Frka, S.; Koch, B. P.; Zhu, Z. Y.; Bracher, A.; Lechtenfeld, O. J.; Neogi, S. B.; Lara, R. J.; Kattner, G.

    2014-07-01

    Extensive analyses of particulate lipids and lipid classes were conducted to gain insight into lipid production and related factors along the biogeochemical provinces of the Eastern Atlantic Ocean. Data are supported by particulate organic carbon (POC), chlorophyll a (Chl a), phaeopigments, Chl a concentrations and carbon content of eukaryotic micro-, nano- and picophytoplankton, including cell abundances for the latter two and for cyanobacteria and prokaryotic heterotrophs. We focused on the productive ocean surface (2 m depth and deep Chl a maximum (DCM). Samples from the deep ocean provided information about the relative reactivity and preservation potential of particular lipid classes. Surface and DCM particulate lipid concentrations (3.5-29.4 μg L-1) were higher than in samples from deep waters (3.2-9.3 μg L-1) where an increased contribution to the POC pool was observed. The highest lipid concentrations were measured in high latitude temperate waters and in the North Atlantic Tropical Gyral Province (13-25°N). Factors responsible for the enhanced lipid synthesis in the eastern Atlantic appeared to be phytoplankton size (micro, nano, pico) and the low nutrient status with microphytoplankton having the most expressed influence in the surface and eukaryotic nano- and picophytoplankton in the DCM layer. Higher lipid to Chl a ratios suggest enhanced lipid biosynthesis in the nutrient poorer regions. The various lipid classes pointed to possible mechanisms of phytoplankton adaptation to the nutritional conditions. Thus, it is likely that adaptation comprises the replacement of membrane phospholipids by non-phosphorus containing glycolipids under low phosphorus conditions. The qualitative and quantitative lipid compositions revealed that phospholipids were the most degradable lipids, and their occurrence decreased with increasing depth. In contrast, wax esters, possibly originating from zooplankton, survived downward transport probably due to the fast sinking

  11. Lipid Cell Biology: A Focus on Lipids in Cell Division.

    Science.gov (United States)

    Storck, Elisabeth M; Özbalci, Cagakan; Eggert, Ulrike S

    2018-06-20

    Cells depend on hugely diverse lipidomes for many functions. The actions and structural integrity of the plasma membrane and most organelles also critically depend on membranes and their lipid components. Despite the biological importance of lipids, our understanding of lipid engagement, especially the roles of lipid hydrophobic alkyl side chains, in key cellular processes is still developing. Emerging research has begun to dissect the importance of lipids in intricate events such as cell division. This review discusses how these structurally diverse biomolecules are spatially and temporally regulated during cell division, with a focus on cytokinesis. We analyze how lipids facilitate changes in cellular morphology during division and how they participate in key signaling events. We identify which cytokinesis proteins are associated with membranes, suggesting lipid interactions. More broadly, we highlight key unaddressed questions in lipid cell biology and techniques, including mass spectrometry, advanced imaging, and chemical biology, which will help us gain insights into the functional roles of lipids.

  12. Airborne Laser Polarization Sensor

    Science.gov (United States)

    Kalshoven, James, Jr.; Dabney, Philip

    1991-01-01

    Instrument measures polarization characteristics of Earth at three wavelengths. Airborne Laser Polarization Sensor (ALPS) measures optical polarization characteristics of land surface. Designed to be flown at altitudes of approximately 300 m to minimize any polarizing or depolarizing effects of intervening atmosphere and to look along nadir to minimize any effects depending on look angle. Data from measurements used in conjunction with data from ground surveys and aircraft-mounted video recorders to refine mathematical models used in interpretation of higher-altitude polarimetric measurements of reflected sunlight.

  13. Polarization of Be stars

    International Nuclear Information System (INIS)

    Johns, M.W.

    1975-01-01

    Linear polarization of starlight may be produced by electron scattering in the extended atmospheres of early type stars. Techniques are investigated for the measurement and interpretation of this polarization. Polarimetric observations were made of twelve visual double star systems in which at least one member was a B type star as a means of separating the intrinsic stellar polarization from the polarization produced in the interstellar medium. Four of the double stars contained a Be star. Evidence for intrinsic polarization was found in five systems including two of the Be systems, one double star with a short period eclipsing binary, and two systems containing only normal early type stars for which emission lines have not been previously reported. The interpretation of these observations in terms of individual stellar polarizations and their wavelength dependence is discussed. The theoretical basis for the intrinsic polarization of early type stars is explored with a model for the disk-like extended atmospheres of Be stars. Details of a polarimeter for the measurement of the linear polarization of astronomical point sources are also presented with narrow band (Δ lambda = 100A) measurements of the polarization of γ Cas from lambda 4000 to lambda 5800

  14. Polarization at SLC

    International Nuclear Information System (INIS)

    Swartz, M.L.

    1988-07-01

    The SLAC Linear Collider has been designed to readily accommodate polarized electron beams. Considerable effort has been made to implement a polarized source, a spin rotation system, and a system to monitor the beam polarization. Nearly all major components have been fabricated. At the current time, several source and polarimeter components have been installed. The installation and commissioning of the entire system will take place during available machine shutdown periods as the commissioning of SLC progresses. It is expected that a beam polarization of 45% will be achieved with no loss in luminosity. 13 refs., 15 figs

  15. Adjusting membrane lipids under salt stress: the case of the moderate halophilic organism Halobacillus halophilus.

    Science.gov (United States)

    Lopalco, Patrizia; Angelini, Roberto; Lobasso, Simona; Köcher, Saskia; Thompson, Melanie; Müller, Volker; Corcelli, Angela

    2013-04-01

    The lipid composition of Halobacillus halophilus was investigated by combined thin-layer chromatography and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analyses of the total lipid extract. Main polar lipids were found to be sulfoquinovosyldiacylglycerol and phosphatidylglycerol, while cardiolipin was a minor lipid together with phosphatidic acid, alanyl-phosphatidylglycerol and two not yet fully identified lipid components. In addition the analyses of residual lipids, associated with denatured proteins after the lipid extraction, revealed the presence of significant amounts of cardiolipin, indicating that it is a not readily extractable phospholipid. Post decay source mass spectrometry analyses allowed the determination of acyl chains of main lipid components. On increasing the culture medium salinity, an increase in the shorter chains and the presence of chain unsaturations were observed. These changes in the lipid core structures might compensate for the increase in packing and rigidity of phospholipid and sulfoglycolipid polar heads in high-salt medium, therefore contributing to the homeostasis of membrane fluidity and permeability in salt stress conditions. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

  16. Electrode material comprising graphene-composite materials in a graphite network

    Science.gov (United States)

    Kung, Harold H.; Lee, Jung K.

    2017-08-08

    A durable electrode material suitable for use in Li ion batteries is provided. The material is comprised of a continuous network of graphite regions integrated with, and in good electrical contact with a composite comprising graphene sheets and an electrically active material, such as silicon, wherein the electrically active material is dispersed between, and supported by, the graphene sheets.

  17. Polymer coating comprising 2-methoxyethyl acrylate units synthesized by surface-initiated atom transfer radical polymerization

    DEFF Research Database (Denmark)

    2011-01-01

    Source: US2012184029A The present invention relates to preparation of a polymer coating comprising or consisting of polymer chains comprising or consisting of units of 2-methoxyethyl acrylate synthesized by Surface-Initiated Atom Transfer Radical Polymerization (SI ATRP) such as ARGET SI ATRP...

  18. Method for recovering aroma concentrate from a caffeine- or theobromine-comprising food base material

    NARCIS (Netherlands)

    Kattenberg, H.R.; Willemsen, J.H.A.; Starmans, D.A.J.; Hoving, H.D.; Winters, M.G.M.

    2002-01-01

    Described is a method for recovering aroma concentrate from a caffeine- or theobromine-comprising food base material, such as coffee or tea, and in particular cocoa, at least comprising the steps of: introducing the food base material into an aqueous extractant and incubating the food base material

  19. Molecular sleds comprising a positively -charged amino acid sequence and a molecular cargo and uses thereof

    NARCIS (Netherlands)

    Mangel, F Walter; Blainey, Paul C; Graziano, Vito; Herrmann, Andreas; McGrath, William J; van Oijen, Antonius Martinus; Xie, Xiaoliang Sunney

    2014-01-01

    The present invention relates to compositions which may comprise a molecular sled linked to cargo and uses thereof. In particular, the present invention relates to a non-naturally occurring or engineered composition which may comprise a molecular sled, linkers and a molecular cargo connected to the

  20. Ball bearings comprising nickel-titanium and methods of manufacture thereof

    Science.gov (United States)

    DellaCorte, Christopher (Inventor); Glennon, Glenn N. (Inventor)

    2012-01-01

    Disclosed herein is a friction reducing nickel-titanium composition. The nickel-titanium composition includes a first phase that comprises nickel and titanium in an atomic ratio of about 0.45:0.55 to about 0.55:0.45; a second phase that comprises nickel and titanium in an atomic ratio of about 0.70:0.30 to about 0.80:0.20; and a third phase that comprises nickel and titanium in an atomic ratio of about 0.52:0.48 to about 0.62:0.38. A bearing for reducing friction comprising a nickel-titanium composition comprising a first phase that comprises nickel and titanium in an atomic ratio of about 0.45:0.55 to about 0.55:0.45; a second phase that comprises nickel and titanium in an atomic ratio of about 0.70:0.30 to about 0.80:0.20; and a third phase that comprises nickel and titanium in an atomic ratio of about 0.52:0.48 to about 0.62:0.38; where the bearing is free from voids and pinholes.

  1. Pharmacogenetics of lipid diseases

    Directory of Open Access Journals (Sweden)

    Ordovas Jose M

    2004-01-01

    Full Text Available Abstract The genetic basis for most of the rare lipid monogenic disorders have been elucidated, but the challenge remains in determining the combination of genes that contribute to the genetic variability in lipid levels in the general population; this has been estimated to be in the range of 40-60 per cent of the total variability. Therefore, the effect of common polymorphisms on lipid phenotypes will be greatly modulated by gene-gene and gene-environment interactions. This approach can also be used to characterise the individuality of the response to lipid-lowering therapies, whether using drugs (pharmacogenetics or dietary interventions (nutrigenetics. In this regard, multiple studies have already described significant interactions between candidate genes for lipid and drug metabolism that modulate therapeutic response--although the outcomes of these studies have been controversial and call for more rigorous experimental design and analytical approaches. Once solid evidence about the predictive value of genetic panels is obtained, risk and therapeutic algorithms can begin to be generated that should provide an accurate measure of genetic predisposition, as well as targeted behavioural modifications or drugs of choice and personalised dosages of these drugs.

  2. Native and enzymatically modified wheat (Triticum aestivum L.) endogenous lipids in bread making: a focus on gas cell stabilization mechanisms.

    Science.gov (United States)

    Gerits, Lien R; Pareyt, Bram; Masure, Hanne G; Delcour, Jan A

    2015-04-01

    Lipopan F and Lecitase Ultra lipases were used in straight dough bread making to study how wheat lipids affect bread loaf volume (LV) and crumb structure setting. Lipase effects on LV were dose and dough piece weight dependent. The bread quality improving mechanisms exerted by endogenous lipids were studied in terms of gluten network strengthening, which indirectly stabilizes gas cells, and in terms of direct interfacial gas cell stabilization. Unlike diacetyl tartaric esters of mono- and diacylglycerols (DATEM, used as control), lipase use did not impact dough extensibility. The effect on dough extensibility was therefore related to its lipid composition at the start of mixing. Both lipases and DATEM strongly increase the levels of polar lipids in dough liquor and their availability for and potential accumulation at gas cell interfaces. Lipases form lysolipids that emulsify other lipids. We speculate that DATEM competes with (endogenous) polar lipids for interacting with gluten proteins. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Lipids, lipid bilayers and vesicles as seen by neutrons

    International Nuclear Information System (INIS)

    Seto, Hideki

    2011-01-01

    Lipid molecules self-assemble into bilayers in water with their hydrocarbon chains facing inward due to their amphiphilic nature. The structural and dynamical properties of lipids and lipid bilayers have been studied by neutron scattering intensively. In this article, 3 topics are shown as typical examples. 1) a time-resolved small-angle neutron scattering on uni-lamellar vesicles composed of deuterated and protonated lipids to determine lipid kinetics, 2) small-angle neutron scattering to investigate spontaneous formation of nanopores on uni-lamellar vesicles, and 3) neutron spin echo study to determine bending modulus of lipid bilayers. (author)

  4. How can lipid nanocarriers improve transdermal delivery of olanzapine?

    Science.gov (United States)

    Iqbal, Nimra; Vitorino, Carla; Taylor, Kevin M G

    2017-06-01

    The development of a transdermal nanocarrier drug delivery system with potential for the treatment of psychiatric disorders, such as schizophrenia and bipolar disorder, is described. Lipid nanocarriers (LN), encompassing various solid:liquid lipid compositions were formulated and assessed as potential nanosystems for transdermal delivery of olanzapine. A previously optimized method of hot high pressure homogenization (HPH) was adopted for the production of the LN, which comprised solid lipid nanoparticles (SLN), nanostructured lipid carriers (NLC) and nanoemulsions (NE). Precirol  ® was selected as the solid lipid for progression of studies. SLN exhibited the best performance for transdermal delivery of olanzapine, based on in vitro release and permeation studies, coupled with results from physicochemical characterization of several solid:liquid lipid formulations. Stability tests, performed to give an indication of long-term storage behavior of the formulations, were in good agreement with previous studies for the best choice of solid:liquid lipid ratio. Overall, these findings highlight the SLN-based formulation as promising for the further inclusion in and production of transdermal patches, representing an innovative therapeutic approach.

  5. Lipid management in ramadan.

    Science.gov (United States)

    Slim, Ines; Ach, Koussay; Chaieb, Larbi

    2015-05-01

    During Ramadan fast, Muslims must refrain from smoking, eating, drinking, having sexual activity, and consuming oral medications from sunrise to sunset. It has been previously shown that Ramadan fasting induces favourable changes on metabolic parameters, reduces oxidative stress and inflammation and promotes cardiovascular benefits. Although ill people are exempted from fasting, most patients with chronic diseases are keen on performing this Islamic-ritual. During recent years, Risk stratification and treatment adjustment during Ramadan are well known and structured in several guidelines for patients with diabetes mellitus. Data related to the effect of Ramadan fast on lipid profiles are less known and several controversies have been reported. Here, we focus on lipid profile and lipid management during Ramadan taking into account comorbidities and cardiovascular risk.

  6. Heart, lipids and hormones

    Directory of Open Access Journals (Sweden)

    Peter Wolf

    2017-05-01

    Full Text Available Cardiovascular disease is the leading cause of death in general population. Besides well-known risk factors such as hypertension, impaired glucose tolerance and dyslipidemia, growing evidence suggests that hormonal changes in various endocrine diseases also impact the cardiac morphology and function. Recent studies highlight the importance of ectopic intracellular myocardial and pericardial lipid deposition, since even slight changes of these fat depots are associated with alterations in cardiac performance. In this review, we overview the effects of hormones, including insulin, thyroid hormones, growth hormone and cortisol, on heart function, focusing on their impact on myocardial lipid metabolism, cardiac substrate utilization and ectopic lipid deposition, in order to highlight the important role of even subtle hormonal changes for heart function in various endocrine and metabolic diseases.

  7. TRANSVERSELY POLARIZED Λ PRODUCTION

    International Nuclear Information System (INIS)

    BORER, D.

    2000-01-01

    Transversely polarized Λ production in hard scattering processes is discussed in terms of a leading twist T-odd fragmentation function which describes the fragmentation of an unpolarized quark into a transversely polarized Λ. We focus on the properties of this function and its relevance for the RHIC and HERMES experiments

  8. Our Polar Past

    Science.gov (United States)

    Clary, Renee; Wandersee, James

    2009-01-01

    The study of polar exploration is fascinating and offers students insights into the history, culture, and politics that affect the developing sciences at the farthest ends of Earth. Therefore, the authors think there is value in incorporating polar exploration accounts within modern science classrooms, and so they conducted research to test their…

  9. Marine polar steroids

    International Nuclear Information System (INIS)

    Stonik, Valentin A

    2001-01-01

    Structures, taxonomic distribution and biological activities of polar steroids isolated from various marine organisms over the last 8-10 years are considered. The peculiarities of steroid biogenesis in the marine biota and their possible biological functions are discussed. Syntheses of some highly active marine polar steroids are described. The bibliography includes 254 references.

  10. Polarized proton beams

    International Nuclear Information System (INIS)

    Roser, T.

    1995-01-01

    The acceleration of polarized proton beams in circular accelerators is complicated by the presence of numerous depolarizing spin resonances. Careful and tedious minimization of polarization loss at each of these resonances allowed acceleration of polarized proton beams up to 22 GeV. It has been the hope that Siberian Snakes, which are local spin rotators inserted into ring accelerators, would eliminate these resonances and allow acceleration of polarized beams with the same ease and efficiency that is now routine for unpolarized beams. First tests at IUCF with a full Siberian Snake showed that the spin dynamics with a Snake can be understood in detail. The author now has results of the first tests of a partial Siberian Snake at the AGS, accelerating polarized protons to an energy of about 25 GeV. These successful tests of storage and acceleration of polarized proton beams open up new possibilities such as stored polarized beams for internal target experiments and high energy polarized proton colliders

  11. Lipid Bilayer Formation on Organic Electronic Materials

    KAUST Repository

    Zhang, Yi

    2018-04-23

    The lipid bilayer is the elemental structure of cell membrane, forming a stable barrier between the interior and exterior of the cell while hosting membrane proteins that enable selective transport of biologically important compounds and cellular recognition. Monitoring the quality and function of lipid bilayers is thus essential and can be performed using electrically active substrates that allow for transduction of signals. Such a promising electronic transducer material is the conducting polymer poly(3,4-ethylenedioxythiophene) doped with poly(styrene sulfonate) (PEDOT:PSS) which has provided a plethora of novel bio transducing architectures. The challenge is however in assembling a bilayer on the conducting polymer surface, which is defect-free and has high mobility. Herein, we investigate the fusion of zwitterionic vesicles on a variety of PEDOT:PSS films, but also on an electron transporting, negatively charged organic semiconductor, in order to understand the surface properties that trigger vesicle fusion. The PEDOT:PSS films are prepared from dispersions containing different concentrations of ethylene glycol included as a formulation additive, which gives a handle to modulate surface physicochemical properties without a compromise on the chemical composition. The strong correlation between the polarity of the surface, the fusion of vesicles and the mobility of the resulting bilayer aides extracting design principles for the development of future conducting polymers that will enable the formation of lipid bilayers.

  12. Polarization Optics in Telecommunications

    CERN Document Server

    Damask, Jay N

    2005-01-01

    The strong investments into optical telecommunications in the late 1990s resulted in a wealth of new research, techniques, component designs, and understanding of polarization effects in fiber. Polarization Optics in Telecommunications brings together recent advances in the field to create a standard, practical reference for component designers and optical fiber communication engineers. Beginning with a sound foundation in electromagnetism, the author offers a dissertation of the spin-vector formalism of polarization and the interaction of light with media. Applications discussed include optical isolators, optical circulators, fiber collimators, and a variety of applied waveplate and prism combinations. Also included in an extended discussion of polarization-mode dispersion (PMD) and polarization-dependent loss (PDL), their representation, behavior, statistical properties, and measurement. This book draws extensively from the technical and patent literature and is an up-to-date reference for researchers and c...

  13. Parallel Polarization State Generation.

    Science.gov (United States)

    She, Alan; Capasso, Federico

    2016-05-17

    The control of polarization, an essential property of light, is of wide scientific and technological interest. The general problem of generating arbitrary time-varying states of polarization (SOP) has always been mathematically formulated by a series of linear transformations, i.e. a product of matrices, imposing a serial architecture. Here we show a parallel architecture described by a sum of matrices. The theory is experimentally demonstrated by modulating spatially-separated polarization components of a laser using a digital micromirror device that are subsequently beam combined. This method greatly expands the parameter space for engineering devices that control polarization. Consequently, performance characteristics, such as speed, stability, and spectral range, are entirely dictated by the technologies of optical intensity modulation, including absorption, reflection, emission, and scattering. This opens up important prospects for polarization state generation (PSG) with unique performance characteristics with applications in spectroscopic ellipsometry, spectropolarimetry, communications, imaging, and security.

  14. Structural characterization of suppressor lipids by high-resolution mass spectrometry

    DEFF Research Database (Denmark)

    Rovillos, Mary Joy; Pauling, Josch Konstantin; Hannibal-Bach, Hans Kristian

    2016-01-01

    RATIONALE: Suppressor lipids were originally identified in 1993 and reported to encompass six lipid classes that enable Saccharomyces cerevisiae to live without sphingolipids. Structural characterization, using non-mass spectrometric approaches, revealed that these suppressor lipids are very long...... chain fatty acid (VLCFA)-containing glycerophospholipids with polar head groups that are typically incorporated into sphingolipids. Here we report, for the first time, the structural characterization of the yeast suppressor lipids using high-resolution mass spectrometry. METHODS: Suppressor lipids were...... isolated by preparative chromatography and subjected to structural characterization using hybrid quadrupole time-of-flight and ion trap-orbitrap mass spectrometry. RESULTS: Our investigation recapitulates the overall structural features of the suppressor lipids and provides an in-depth characterization...

  15. NOAA Climate Data Record (CDR) of AVHRR Polar Pathfinder (APP) Cryosphere

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This NOAA Climate Data Record (CDR) contains the AVHRR Polar Pathfinder (APP) product. APP is a fundamental CDR comprised of calibrated and navigated AVHRR channel...

  16. Lipid storage myopathies.

    Science.gov (United States)

    Bruno, Claudio; Dimauro, Salvatore

    2008-10-01

    The aim of this review is to provide an update on disorders of lipid metabolism affecting skeletal muscle exclusively or predominantly and to summarize recent clinical, genetic, and therapeutic studies in this field. Over the past 5 years, new clinical phenotypes and genetic loci have been described, unusual pathogenic mechanisms have been elucidated, and novel pharmacological approaches have been developed. At least one genetic defect responsible for the myopathic form of CoQ10 deficiency has been identified, causing a disorder that is allelic with the late-onset riboflavine-responsive form of multiple acyl-coenzyme A dehydrogenation deficiency. Novel mechanisms involved in the lipolytic breakdown of cellular lipid depots have been described and have led to the identification of genes and mutations responsible for multisystemic neutral lipid storage disorders, characterized by accumulation of triglyceride in multiple tissues, including muscle. Defects in lipid metabolism can affect either the mitochondrial transport and oxidation of exogenous fatty acid or the catabolism of endogenous triglycerides. These disorders impair energy production and almost invariably involve skeletal muscle, causing progressive myopathy with muscle weakness, or recurrent acute episodes of rhabdomyolysis triggered by exercise, fasting, or infections. Clinical and genetic characterization of these disorders has important implications both for accurate diagnostic approach and for development of therapeutic strategies.

  17. Lipids in airway secretions

    International Nuclear Information System (INIS)

    Bhaskar, K.R.; DeFeudis O'Sullivan, D.; Opaskar-Hincman, H.; Reid, L.M.

    1987-01-01

    Lipids form a significant portion of airway mucus yet they have not received the same attention that epithelial glycoproteins have. We have analysed, by thin layer chromatography, lipids present in airway mucus under 'normal' and hypersecretory (pathological) conditions.The 'normals' included (1) bronchial lavage obtained from healthy human volunteers and from dogs and (2) secretions produced ''in vitro'' by human (bronchial) and canine (tracheal) explants. Hypersecretory mucus samples included (1) lavage from dogs made bronchitic by exposure to SO 2 , (2) bronchial aspirates from acute and chronic tracheostomy patients, (3) sputum from patients with cystic fibrosis and chronic bronchitis and (4) postmortem secretions from patients who died from sudden infant death syndrome (SIDS) or from status asthmaticus. Cholesterol was found to be the predominant lipid in 'normal' mucus with lesser amounts of phospholipids. No glycolipids were detected. In the hypersecretory mucus, in addition to neutral and phospholipids, glycolipids were present in appreciable amounts, often the predominant species, suggesting that these may be useful as markers of disease. Radioactive precursors 14 C acetate and 14 C palmitate were incorporated into lipids secreted ''in vitro'' by canine tracheal explants indicating that they are synthesised by the airway. (author)

  18. Exogenous lipid pneumonia

    International Nuclear Information System (INIS)

    Bernasconi, A.; Gavelli, G.; Zompatori, M.; Galleri, C.; Zanasi, A.; Fabbri, M.; Bazzocchi, F.

    1988-01-01

    Exogenous lipid pneumonia (ELP) is caused by the aspiration of animal, vegetal or, more often, mineral oils. Even though it may also be acute, ELP is most frequently a chronic disease, affecting people with predisposing factors, such as neuromuscular disorders, structural abnormalities and so on; very often exogenous lipid pneumonia is found in tracheotomized patients. The pathology of lipid pneumonia is a chronic inflammatory process evolving in foreign-body-like reaction, and eventually in ''end-stage lung'' condition. Clinically, most patients are asymptomatic; few cases only present with cough, dyspnea and chest pain. Eight cases of ELP, studied over the past 3 years, are described in this paper. All the patients were examined by chest radiographs and standard tomograms; 3 patients underwent CT. X-ray features were mono/bilateral consolidation of the lower zones, with air bronchogram and variable reduction in volume. CT density was not specific for fat tissue. In all cases the diagnosis was confirmed at biopsy. In 5 patients, followed for at least one year, clinical-radiological features showed no change. Thus, complications of ELP (especially malignant evolution) could be excluded. The authors conclude that lipid pneumonia must be considered in differential diagnosis of patients with history of usage of oils and compatible X-ray findings. The usefulness of an accurate follow-up is stressed

  19. Lipid Therapy for Intoxications

    NARCIS (Netherlands)

    Robben, Joris Henricus; Dijkman, Marieke Annet

    This review discusses the use of intravenous lipid emulsion (ILE) in the treatment of intoxications with lipophilic agents in veterinary medicine. Despite growing scientific evidence that ILE has merit in the treatment of certain poisonings, there is still uncertainty on the optimal composition of

  20. Lipid Therapy for Intoxications

    NARCIS (Netherlands)

    Robben, Joris Henricus; Dijkman, Marieke Annet

    2017-01-01

    This review discusses the use of intravenous lipid emulsion (ILE) in the treatment of intoxications with lipophilic agents in veterinary medicine. Despite growing scientific evidence that ILE has merit in the treatment of certain poisonings, there is still uncertainty on the optimal composition of

  1. Solvent Extraction and Characterization of Neutral Lipids in Oocystis sp

    Energy Technology Data Exchange (ETDEWEB)

    Anthony, Renil [Department of Mechanical Engineering, Ohio University, Athens, OH (United States); Stuart, Ben, E-mail: stuart@ohio.edu [Department of Civil Engineering, Ohio University, Athens, OH (United States)

    2015-01-20

    Microalgae are a favorable feedstock for bioproducts and biofuels due to their high oil content, fast growth rates, and low resource demands. Solvent lipid extraction efficiency from microalgae is dependent on algal strain and the extraction solvent. Four non-polar extraction solvents were evaluated for the recovery of neutral cellular lipids from microalgae Oocystis sp. (University of Texas at Austin LB2396). Methylene chloride, hexane, diethyl ether, and cyclohexane were selected as the extraction solvents. The lipid extracts were derivatized and analyzed using gas chromatography–mass spectroscopy. All solvent extracts contained hexadecanoic acid, linoleic acid, and linolenic acid; accounting for 70% of total lipid content with a proportional wt% composition of the three fatty acids, except for the hexane extracts that showed only hexadecanoic acid and linoleic acid. While not statistically differentiated, methylene chloride proved to be the most effective solvent for Oocystis sp. among the four solvents tested with a total average neutral lipid recovery of 0.25% of dry weight followed by diethyl ether (0.18%), cyclohexane (0.14%), and hexane (0.11%). This research presents a simple methodology to optimize the selection of lipid specific extraction solvents for the microalgal strain selected.

  2. Solvent Extraction and Characterization of Neutral Lipids in Oocystis sp

    International Nuclear Information System (INIS)

    Anthony, Renil; Stuart, Ben

    2015-01-01

    Microalgae are a favorable feedstock for bioproducts and biofuels due to their high oil content, fast growth rates, and low resource demands. Solvent lipid extraction efficiency from microalgae is dependent on algal strain and the extraction solvent. Four non-polar extraction solvents were evaluated for the recovery of neutral cellular lipids from microalgae Oocystis sp. (University of Texas at Austin LB2396). Methylene chloride, hexane, diethyl ether, and cyclohexane were selected as the extraction solvents. The lipid extracts were derivatized and analyzed using gas chromatography–mass spectroscopy. All solvent extracts contained hexadecanoic acid, linoleic acid, and linolenic acid; accounting for 70% of total lipid content with a proportional wt% composition of the three fatty acids, except for the hexane extracts that showed only hexadecanoic acid and linoleic acid. While not statistically differentiated, methylene chloride proved to be the most effective solvent for Oocystis sp. among the four solvents tested with a total average neutral lipid recovery of 0.25% of dry weight followed by diethyl ether (0.18%), cyclohexane (0.14%), and hexane (0.11%). This research presents a simple methodology to optimize the selection of lipid specific extraction solvents for the microalgal strain selected.

  3. Age and seasonal variability of polybrominated diphenyl ethers in free-ranging East Greenland polar bears (Ursus maritimus)

    International Nuclear Information System (INIS)

    Dietz, Rune; Riget, Frank F.; Sonne, Christian; Letcher, Robert J.; Backus, Sean; Born, Erik W.; Kirkegaard, Maja; Muir, Derek C.G.

    2007-01-01

    Polybrominated diphenyl ethers (PBDEs) were analysed in adipose tissue from 92 East Greenland polar bears (Ursus maritimus) sampled during 1999-2001. Mean ΣPBDE concentrations were 70 ng/g lipid weight (lw) (range: 22-192 ng/g lw) and showed no relationship with age or sex. Of the 32 analysed PBDE congeners; BDE47, BDE153, BDE99 and BDE100 dominated, and comprised 99.6% of the ΣPBDE concentration. The ΣPBDE concentration had a highly significant correlation with ΣPCB, ΣCHL, dieldrin, HCB and ΣHCH concentrations. We found a seasonal pattern of median ΣPBDE concentration with 1.2 to 1.8 times higher concentrations in March to July than the rest of the year. The seasonal variation also provides a clue to the seasonal exposure, bio-availability, toxic exposure and degradation. We suggest that future geographical PBDE data comparisons may not need corrections for sex or age, but such data sets should be corrected for seasonal variability, using the presented correctional trigonometric regression. - Mean ΣPBDE concentrations of East Greenland polar bears (Ursus maritimus) were 69.5 ng/g lw (range: 21.7-192 ng/g lw) and showed a seasonal pattern with no relationship with age and sex

  4. Alignment of Carbon Nanotubes Comprising Magnetically Sensitive Metal Oxides in Nanofluids

    Science.gov (United States)

    Hong, Haiping (Inventor); Peterson, G. P. " Bud" (Inventor)

    2016-01-01

    The present invention is a nanoparticle mixture or suspension or nanofluid comprising nonmagnetically sensitive nanoparticles, magnetically sensitive nanoparticles, and surfactant(s). The present invention also relates to methods of preparing and using the same.

  5. Combination Comprising Parthenolide For Use In The Treatment Of Alzheimer's Disease And Other Neurodegenerative Disorders

    KAUST Repository

    Bajic, Vladimir B.; Essack, Magbubah

    2015-01-01

    The present invention generally concerns particular methods and compositions for treatment of a neurodegenerative disease, such as Alzheimer's Disease. In particular embodiments, there is a composition comprising Parthenolide and a second agent

  6. Polar bears at risk

    Energy Technology Data Exchange (ETDEWEB)

    Norris, S.; Rosentrater, L.; Eid, P.M. [WWF International Arctic Programme, Oslo (Norway)

    2002-05-01

    Polar bears, the world's largest terrestrial carnivore, spend much of their lives on the arctic sea ice. This is where they hunt and move between feeding, denning, and resting areas. The world population, estimated at 22,000 bears, is made up of 20 relatively distinct populations varying in size from a few hundred to a few thousand animals. About 60 per cent of all polar bears are found in Canada. In general, the status of this species is stable, although there are pronounced differences between populations. Reductions in the extent and thickness of sea ice has lead the IUCN Polar Bear Specialist Group to describe climate change as one of the major threats facing polar bears today. Though the long-term effects of climate change will vary in different areas of the Arctic, impacts on the condition and reproductive success of polar bears and their prey are likely to be negative. Longer ice-free periods resulting from earlier break-up of sea ice in the spring and later formation in the fall is already impacting polar bears in the southern portions of their range. In Canada's Hudson Bay, for example, bears hunt on the ice through the winter and into early summer, after which the ice melts completely, forcing bears ashore to fast on stored fat until freeze-up in the fall. The time bears have on the ice to hunt and build up their body condition is cut short when the ice melts early. Studies from Hudson Bay show that for every week earlier that ice break-up occurs, bears will come ashore 10 kg lighter and in poorer condition. It is likely that populations of polar bears dividing their time between land and sea will be severely reduced and local extinctions may occur as greenhouse gas emissions continue to rise and sea ice melts. Expected changes in regional weather patterns will also impact polar bears. Rain in the late winter can cause maternity dens to collapse before females and cubs have departed, thus exposing occupants to the elements and to predators. Such

  7. Big, Fat World of Lipids

    Science.gov (United States)

    ... offered a more quantitative and systematic approach to lipids research. Much of the effort has been led by a research consortium called LIPID MAPS. With funding from the National Institutes of ...

  8. Amphotericin B Lipid Complex Injection

    Science.gov (United States)

    Amphotericin B lipid complex injection is used to treat serious, possibly life-threatening fungal infections in people who did ... respond or are unable to tolerate conventional amphotericin B therapy. Amphotericin B lipid complex injection is in ...

  9. Photodetection, photon event localization and position tomography device comprising a gammagraphy camera equipped wit such devices

    International Nuclear Information System (INIS)

    Jatteau, M.R.

    1984-01-01

    This device of photodetection and photon event (and noticeably scintillations) localization comprises at least a photomultiplier tube with unique photomultiplying structure and in front of this tube, a net of juxtaposed conduction metal wires excited by voltage pulses. This net comprises only 2n metallic wires to assure the localization of 2sup(2n) possible positions, and that is one of its characteristics [fr

  10. Tritium incorporation in lipid preparations by catalytic methods

    International Nuclear Information System (INIS)

    Shevchenko, V.P.; Bezuglov, V.V.; Myasoedov, N.F.

    1983-01-01

    A series of polar and nonpolar lipids labelled with tritium, which are the most important components of biological membranes, has been prepared. Possible ways to increase the yield and molar radioactivity of biologically active preparations are considered. A supposition is made, that all the factors promoting dissociative adsorption of substrates during heterogeneous catalysis, should promote the increase in product yield of the initial structure and preparation of labelled preparations with molar radioactivity sufficient for carrying out the major part of biological studies

  11. Polarized atomic beams for targets

    International Nuclear Information System (INIS)

    Grueebler, W.

    1984-01-01

    The basic principle of the production of polarized atomic hydrogen and deuterium beams are reviewed. The status of the present available polarization, density and intensity are presented. The improvement of atomic beam density by cooling the hydrogen atoms to low velocity is discussed. The possible use of polarized atomic beams as targets in storage rings is shown. It is proposed that polarized atomic beams can be used to produce polarized gas targets with high polarization and greatly improved density

  12. Heidelberg polarized alkali source

    International Nuclear Information System (INIS)

    Kraemer, D.; Steffens, E.; Jaensch, H.; Philipps Universitaet, Marburg, Germany)

    1984-01-01

    A new atomic beam type polarized alkali ion source has been installed at Heidelberg. In order to improve the beam polarization considerably optical pumping is applied in combination with an adiabatic medium field transition which results in beams in single hyperfine sublevels. The m state population is determined by laser-induced fluorescence spectroscopy. Highly polarized beams (P/sub s/ > 0.9, s = z, zz) with intensities of 30 to 130 μA can be extracted for Li + and Na + , respectively

  13. Metabolic incorporation of unsaturated fatty acids into boar spermatozoa lipids and de novo formation of diacylglycerols

    DEFF Research Database (Denmark)

    Svetlichnyy, V.; Müller, P.; Günther-Pomorski, Thomas

    2014-01-01

    Lipids play an important role in the maturation, viability and function of sperm cells. In this study, we examined the neutral and polar lipid composition of boar spermatozoa by thin-layer chromatography/mass spectrometry. Main representatives of the neutral lipid classes were diacylglycerols...... containing saturated (myristoyl, palmitoyl and stearoyl) fatty acyl residues. Glycerophosphatidylcholine and glycerophosphatidylethanolamine with alk(en)yl ether residues in the sn-1 position and unsaturated long chained fatty acyl residues in sn-2 position were identified as the most prominent polar lipids....... The only glycoglycerolipid was sulfogalactosylglycerolipid carrying 16:0-alkyl- and 16:0-acyl chains. Using stable isotope-labelling, the metabolic incorporation of exogenously supplied fatty acids was analysed. Boar spermatozoa incorporated hexadecenoic (16:1), octadecenoic (18:1), octadecadienoic (18...

  14. Modulating p56Lck in T-Cells by a Chimeric Peptide Comprising Two Functionally Different Motifs of Tip from Herpesvirus saimiri

    Directory of Open Access Journals (Sweden)

    Jean-Paul Vernot

    2015-01-01

    Full Text Available The Lck interacting protein Tip of Herpesvirus saimiri is responsible for T-cell transformation both in vitro and in vivo. Here we designed the chimeric peptide hTip-CSKH, comprising the Lck specific interacting motif CSKH of Tip and its hydrophobic transmembrane sequence (hTip, the latter as a vector targeting lipid rafts. We found that hTip-CSKH can induce a fivefold increase in proliferation of human and Aotus sp. T-cells. Costimulation with PMA did not enhance this proliferation rate, suggesting that hTip-CSKH is sufficient and independent of further PKC stimulation. We also found that human Lck phosphorylation was increased earlier after stimulation when T-cells were incubated previously with hTip-CSKH, supporting a strong signalling and proliferative effect of the chimeric peptide. Additionally, Lck downstream signalling was evident with hTip-CSKH but not with control peptides. Importantly, hTip-CSKH could be identified in heavy lipid rafts membrane fractions, a compartment where important T-cell signalling molecules (LAT, Ras, and Lck are present during T-cell activation. Interestingly, hTip-CSKH was inhibitory to Jurkat cells, in total agreement with the different signalling pathways and activation requirements of this leukemic cell line. These results provide the basis for the development of new compounds capable of modulating therapeutic targets present in lipid rafts.

  15. Modulating p56Lck in T-Cells by a Chimeric Peptide Comprising Two Functionally Different Motifs of Tip from Herpesvirus saimiri.

    Science.gov (United States)

    Vernot, Jean-Paul; Perdomo-Arciniegas, Ana María; Pérez-Quintero, Luis Alberto; Martínez, Diego Fernando

    2015-01-01

    The Lck interacting protein Tip of Herpesvirus saimiri is responsible for T-cell transformation both in vitro and in vivo. Here we designed the chimeric peptide hTip-CSKH, comprising the Lck specific interacting motif CSKH of Tip and its hydrophobic transmembrane sequence (hTip), the latter as a vector targeting lipid rafts. We found that hTip-CSKH can induce a fivefold increase in proliferation of human and Aotus sp. T-cells. Costimulation with PMA did not enhance this proliferation rate, suggesting that hTip-CSKH is sufficient and independent of further PKC stimulation. We also found that human Lck phosphorylation was increased earlier after stimulation when T-cells were incubated previously with hTip-CSKH, supporting a strong signalling and proliferative effect of the chimeric peptide. Additionally, Lck downstream signalling was evident with hTip-CSKH but not with control peptides. Importantly, hTip-CSKH could be identified in heavy lipid rafts membrane fractions, a compartment where important T-cell signalling molecules (LAT, Ras, and Lck) are present during T-cell activation. Interestingly, hTip-CSKH was inhibitory to Jurkat cells, in total agreement with the different signalling pathways and activation requirements of this leukemic cell line. These results provide the basis for the development of new compounds capable of modulating therapeutic targets present in lipid rafts.

  16. The representation of neutron polarization

    International Nuclear Information System (INIS)

    Byrne, J.

    1979-01-01

    Neutron beam polarization representation is discussed under the headings; transfer matrices, coherent parity violation for neutrons, neutron spin rotation in helical magnetic fields, polarization and interference. (UK)

  17. Inkjet printed circularly polarized antennas for GPS applications

    KAUST Repository

    Farooqui, Muhammad Fahad; Shamim, Atif

    2014-01-01

    gain of 0.2 dBi at 1.575 GHz with 3-dB axial ratio bandwidth of 3.8%. The second antenna design comprises a modified monopole in the form of an inverted L and has been termed as circularly polarized inverted L antenna (CILA). The antenna shows a gain

  18. Interferometric polarization control

    International Nuclear Information System (INIS)

    Chuss, David T.; Wollack, Edward J.; Moseley, S. Harvey; Novak, Giles

    2006-01-01

    We develop the Jones and Mueller matrices for structures that allow control of the path length difference between two linear orthogonal polarizations and consider the effect of placing multiple devices in series. Specifically, we find that full polarization modulation (measurement of Stokes Q, U, and V) can be achieved by placing two such modulators in series if the relative angles of the beam-splitting grids with respect to the analyzer orientation are appropriately chosen. Such a device has several potential advantages over a spinning wave plate modulator for measuring astronomical polarization in the far infrared through millimeter: (i) The use of small, linear motions eliminates the need for cryogenic rotational bearings; (ii) the phase flexibility allows measurement of circular as well as linear polarization; and (iii) this architecture allows for both multiwavelength and broadband modulation. We also present initial laboratory results

  19. Dynamic nuclear spin polarization

    Energy Technology Data Exchange (ETDEWEB)

    Stuhrmann, H B [GKSS-Forschungszentrum Geesthacht GmbH (Germany)

    1996-11-01

    Polarized neutron scattering from dynamic polarized targets has been applied to various hydrogenous materials at different laboratories. In situ structures of macromolecular components have been determined by nuclear spin contrast variation with an unprecedented precision. The experiments of selective nuclear spin depolarisation not only opened a new dimension to structural studies but also revealed phenomena related to propagation of nuclear spin polarization and the interplay of nuclear polarisation with the electronic spin system. The observation of electron spin label dependent nuclear spin polarisation domains by NMR and polarized neutron scattering opens a way to generalize the method of nuclear spin contrast variation and most importantly it avoids precontrasting by specific deuteration. It also likely might tell us more about the mechanism of dynamic nuclear spin polarisation. (author) 4 figs., refs.

  20. Polarized proton colliders

    International Nuclear Information System (INIS)

    Roser, T.

    1995-01-01

    High energy polarized beam collisions will open up the unique physics opportunities of studying spin effects in hard processes. This will allow the study of the spin structure of the proton and also the verification of the many well documented expectations of spin effects in perturbative QCD and parity violation in W and Z production. Proposals for polarized proton acceleration for several high energy colliders have been developed. A partial Siberian Snake in the AGS has recently been successfully tested and full Siberian Snakes, spin rotators, and polarimeters for RHIC are being developed to make the acceleration of polarized beams to 250 GeV possible. This allows for the unique possibility of colliding two 250 GeV polarized proton beams at luminosities of up to 2 x 10 32 cm -2 s -1

  1. Plasma polarization spectroscopy

    International Nuclear Information System (INIS)

    Iwamae, Atsushi; Horimoto, Yasuhiro; Fujimoto, Takashi; Hasegawa, Noboru; Sukegawa, Kouta; Kawachi, Tetsuya

    2005-01-01

    The electron velocity distribution function (EVDF) in plasma can be anisotropic in laser-produced plasmas. We have developed a new technique to evaluate the polarization degree of the emission lines in the extreme vacuum ultra violet wavelength region. The polarization of the emission lines and the continuums from the lithium-like nitrogen and from helium- and hydrogen-like carbon in recombining plasma is evaluated. Particle simulation in the velocity space gives the time scale for relaxation of anisotropic EVDFs. (author)

  2. No More Polarization, Please!

    OpenAIRE

    Reinholt, Mia

    2006-01-01

    The organizational science literature on motivation has for long been polarized into two main positions; the organizational economic position focusing on extrinsic motivation and the organizational behavior position emphasizing intrinsic motivation. With the rise of the knowledge economy and the increasing levels of complexities it entails, such polarization is not fruitful in the attempt to explain motivation of organizational members. This paper claims that a more nuanced perspective on mot...

  3. Inertial polarization of dielectrics

    OpenAIRE

    Zavodovsky, A. G.

    2011-01-01

    It was proved that accelerated motion of a linear dielectric causes its polarization. Accelerated translational motion of a dielectric's plate leads to the positive charge of the surface facing the direction of motion. Metal plates of a capacitor were used to register polarized charges on a dielectric's surface. Potential difference between the capacitor plates is proportional to acceleration, when acceleration is constant potential difference grows with the increase of a dielectric's area, o...

  4. Semisynthetic Lipopeptides Derived from Nisin Display Antibacterial Activity and Lipid II Binding on Par with That of the Parent Compound

    NARCIS (Netherlands)

    Koopmans, Timo; Wood, Thomas M.; 't Hart, Peter; Kleijn, Laurens H. J.; Hendrickx, Antoni P. A.; Willems, Rob J. L.; Breukink, Eefjan; Martin, Nathaniel I.

    2015-01-01

    The lipid II-binding N-terminus of nisin, comprising the so-called A/B ring system, was synthetically modified to provide antibacterially active and proteolytically stable derivatives. A variety of lipids were coupled to the C-terminus of the nisin A/B ring system to generate semisynthetic

  5. Symptomatic lipid storage in carriers for the PNPLA2 gene.

    Science.gov (United States)

    Janssen, Mirian C H; van Engelen, Baziel; Kapusta, Livia; Lammens, Martin; van Dijk, Martin; Fischer, Judith; van der Graaf, Marinette; Wevers, Ron A; Fahrleitner, Manuela; Zimmermann, Robert; Morava, Eva

    2013-08-01

    Neutral lipid storage disease comprises a heterogeneous group of inherited disorders characterized by severe accumulation of cytoplasmic triglyceride droplets in several tissues and neutrophils. A novel type of autosomal recessive lipid myopathy due to PNPLA2 mutations was recently described with associated cardiac disease, myopathy and frequent infections, but without ichthyosis. Here we describe the clinical and biochemical characteristics of a long surviving patient and report on four carrier family members with diverse clinical involvement. Interestingly, heterozygous patients show neutral lipid storage in muscle and in the keratocytes of the skin, Jordans' bodies, mild myopathy and frequent infections. Biochemical analysis of fibroblasts obtained from patients revealed increased triglyceride storage and reduced lipid droplet-associated triglyceride hydrolase activity. Together, our data implicate that the wild-type allele cannot fully compensate for the mutated dysfunctional allele of PNPLA2 leading to triglyceride accumulation in muscle and mild myopathy in PNPLA2 mutation carriers. The presence of neutral lipid droplets in the skin in PNPLA2 mutation carriers strengthens the link between NLSD and other neutral lipid storage diseases with ichthyosis.

  6. The Polarization of Achernar

    Science.gov (United States)

    McDavid, D.

    2005-11-01

    Recent near-infrared measurements of the angular diameter of Achernar (the bright Be star alpha Eridani) with the ESO VLT interferometer have been interpreted as the detection of an extremely oblate photosphere, with a ratio of equatorial to polar radius of at least 1.56 ± 0.05 and a minor axis orientation of 39° ± 1° (from North to East). The optical linear polarization of this star during an emission phase in 1995 September was 0.12 ± 0.02% at position angle 37° ± 8° (in equatorial coordinates), which is the direction of the projection of the rotation axis on the plane of the sky according to the theory of polarization by electron scattering in an equatorially flattened circumstellar disk. These two independent determinations of the orientation of the rotation axis are therefore in agreement. The observational history of correlations between Hα emission and polarization as found in the literature is that of a typical Be star, with the exception of an interesting question raised by the contrast between Schröder's measurement of a small polarization perpendicular to the projected rotation axis in 1969--70 and Tinbergen's measurement of zero polarization in 1974.5, both at times when emission was reportedly absent.

  7. Inkjet printed circularly polarized antennas for GPS applications

    KAUST Repository

    Farooqui, Muhammad Fahad

    2014-07-01

    Two novel, inkjet printed circularly polarized antenna designs are presented for GPS applications. First antenna design comprises a planar monopole which has been made circularly polarized by the introduction of an L-shaped slit. The antenna shows a gain of 0.2 dBi at 1.575 GHz with 3-dB axial ratio bandwidth of 3.8%. The second antenna design comprises a modified monopole in the form of an inverted L and has been termed as circularly polarized inverted L antenna (CILA). The antenna shows a gain of -2 dBi at 1.575 GHz with 3-dB axial ratio bandwidth of 4.1%. Both the antenna designs are attractive for mobile applications.

  8. Fusion of a polarized projectile with a polarized target

    International Nuclear Information System (INIS)

    Christley, J.A.; Johnson, R.C.; Thompson, I.J.

    1995-01-01

    The fusion cross sections for a polarized target with both unpolarized and polarized projectiles are studied. Expressions for the observables are given for the case when both nuclei are polarized. Calculations for fusion of an aligned 165 Ho target with 16 O and polarized 7 Li beams are presented

  9. The small molecule fenpropimorph rapidly converts chloroplast membrane lipids to triacylglycerols in Chlamydomonas reinhardtii

    Directory of Open Access Journals (Sweden)

    Hanul eKim

    2015-02-01

    Full Text Available Concern about global warming has prompted an intense interest in developing economical methods of producing biofuels. Microalgae provide a promising platform for biofuel production, because they accumulate high levels of lipids, and do not compete with food or feed sources. However, current methods of producing algal oil involve subjecting the microalgae to stress conditions, such as nitrogen deprivation, and are prohibitively expensive. Here, we report that the fungicide fenpropimorph rapidly causes high levels of neutral lipids to accumulate in Chlamydomonas reinhardtii cells. When treated with fenpropimorph (10 μg mL–1 for 1 h, Chlamydomonas cells accumulated at least four-fold the amount of triacylglycerols (TAGs present in the untreated control cells. Furthermore, the quantity of TAGs present after 1 h of fenpropimorph treatment was over two-fold higher than that formed after 9 days of nitrogen starvation in medium with no acetate supplement. Biochemical analysis of lipids revealed that the accumulated TAGs were derived mainly from chloroplast polar membrane lipids. Such a conversion of chloroplast polar lipids to TAGs is desirable for biodiesel production, because polar lipids are usually removed during the biodiesel production process. Thus, our data exemplified that a cost and time effective method of producing TAGs is possible using fenpropimorph or similar drugs.

  10. Polarized Light Microscopy

    Science.gov (United States)

    Frandsen, Athela F.

    2016-01-01

    Polarized light microscopy (PLM) is a technique which employs the use of polarizing filters to obtain substantial optical property information about the material which is being observed. This information can be combined with other microscopy techniques to confirm or elucidate the identity of an unknown material, determine whether a particular contaminant is present (as with asbestos analysis), or to provide important information that can be used to refine a manufacturing or chemical process. PLM was the major microscopy technique in use for identification of materials for nearly a century since its introduction in 1834 by William Fox Talbot, as other techniques such as SEM (Scanning Electron Microscopy), FTIR (Fourier Transform Infrared spectroscopy), XPD (X-ray Powder Diffraction), and TEM (Transmission Electron Microscopy) had not yet been developed. Today, it is still the only technique approved by the Environmental Protection Agency (EPA) for asbestos analysis, and is often the technique first applied for identification of unknown materials. PLM uses different configurations in order to determine different material properties. With each configuration additional clues can be gathered, leading to a conclusion of material identity. With no polarizing filter, the microscope can be used just as a stereo optical microscope, and view qualities such as morphology, size, and number of phases. With a single polarizing filter (single polars), additional properties can be established, such as pleochroism, individual refractive indices, and dispersion staining. With two polarizing filters (crossed polars), even more can be deduced: isotropy vs. anisotropy, extinction angle, birefringence/degree of birefringence, sign of elongation, and anomalous polarization colors, among others. With the use of PLM many of these properties can be determined in a matter of seconds, even for those who are not highly trained. McCrone, a leader in the field of polarized light microscopy, often

  11. Electric circuit breaker comprising a plurality of vacuum interrupters simultaneously operated by a common operator

    Science.gov (United States)

    Barkan, Philip; Imam, Imdad

    1980-01-01

    This circuit breaker comprises a plurality of a vacuum-type circuit interrupters, each having a movable contact rod. A common operating device for the interrupters comprises a linearly-movable operating member. The interrupters are mounted at one side of the operating member with their movable contact rods extending in a direction generally toward the operating member. Means is provided for mechanically coupling the operating member to the contact rods, and this means comprises a plurality of insulating operating rods, each connected at one end to the operating member and at its opposite end to one of the movable contact rods. The operating rods are of substantially equal length and have longitudinal axes that converge and intersect at substantially a common point.

  12. Spastin binds to lipid droplets and affects lipid metabolism.

    Directory of Open Access Journals (Sweden)

    Chrisovalantis Papadopoulos

    2015-04-01

    Full Text Available Mutations in SPAST, encoding spastin, are the most common cause of autosomal dominant hereditary spastic paraplegia (HSP. HSP is characterized by weakness and spasticity of the lower limbs, owing to progressive retrograde degeneration of the long corticospinal axons. Spastin is a conserved microtubule (MT-severing protein, involved in processes requiring rearrangement of the cytoskeleton in concert to membrane remodeling, such as neurite branching, axonal growth, midbody abscission, and endosome tubulation. Two isoforms of spastin are synthesized from alternative initiation codons (M1 and M87. We now show that spastin-M1 can sort from the endoplasmic reticulum (ER to pre- and mature lipid droplets (LDs. A hydrophobic motif comprised of amino acids 57 through 86 of spastin was sufficient to direct a reporter protein to LDs, while mutation of arginine 65 to glycine abolished LD targeting. Increased levels of spastin-M1 expression reduced the number but increased the size of LDs. Expression of a mutant unable to bind and sever MTs caused clustering of LDs. Consistent with these findings, ubiquitous overexpression of Dspastin in Drosophila led to bigger and less numerous LDs in the fat bodies and increased triacylglycerol levels. In contrast, Dspastin overexpression increased LD number when expressed specifically in skeletal muscles or nerves. Downregulation of Dspastin and expression of a dominant-negative variant decreased LD number in Drosophila nerves, skeletal muscle and fat bodies, and reduced triacylglycerol levels in the larvae. Moreover, we found reduced amount of fat stores in intestinal cells of worms in which the spas-1 homologue was either depleted by RNA interference or deleted. Taken together, our data uncovers an evolutionarily conserved role of spastin as a positive regulator of LD metabolism and open up the possibility that dysfunction of LDs in axons may contribute to the pathogenesis of HSP.

  13. When measured spin polarization is not spin polarization

    International Nuclear Information System (INIS)

    Dowben, P A; Wu Ning; Binek, Christian

    2011-01-01

    Spin polarization is an unusually ambiguous scientific idiom and, as such, is rarely well defined. A given experimental methodology may allow one to quantify a spin polarization but only in its particular context. As one might expect, these ambiguities sometimes give rise to inappropriate interpretations when comparing the spin polarizations determined through different methods. The spin polarization of CrO 2 and Cr 2 O 3 illustrate some of the complications which hinders comparisons of spin polarization values. (viewpoint)

  14. Semipermeable thin-film membranes comprising siloxane, alkoxysilyl and aryloxysilyl oligomers and copolymers

    Science.gov (United States)

    Babcock, Walter C.; Friesen, Dwayne T.

    1988-01-01

    Novel semiperimeable membranes and thin film composite (TFC) gas separation membranes useful in the separation of oxygen, nitrogen, hydrogen, water vapor, methane, carbon dioxide, hydrogen sulfide, lower hydrocarbons, and other gases are disclosed. The novel semipermeable membranes comprise the polycondensation reaction product of two complementary polyfunctional compounds, each having at least two functional groups that are mutually reactive in a condensation polymerization reaction, and at least one of which is selected from siloxanes, alkoxsilyls and aryloxysilyls. The TFC membrane comprises a microporous polymeric support, the surface of which has the novel semipermeable film formed thereon, preferably by interfacial polymerization.

  15. The evolution of tensor polarization

    International Nuclear Information System (INIS)

    Huang, H.; Lee, S.Y.; Ratner, L.

    1993-01-01

    By using the equation of motion for the vector polarization, the spin transfer matrix for spin tensor polarization, the spin transfer matrix for spin tensor polarization is derived. The evolution equation for the tensor polarization is studied in the presence of an isolate spin resonance and in the presence of a spin rotor, or snake

  16. The polarization of fast neutrons

    International Nuclear Information System (INIS)

    Talov, V.V.

    2000-01-01

    The present work is the review of polarization of fast neutrons and methods of polarization analysis. This also includes information about polarization of fast neutrons from first papers, which described polarization in the D(d,n) 3 He, 7 Li(p,n) 7 Be, and T(p,n) 3 He reactions. (authors)

  17. Polarized particles in storage rings

    International Nuclear Information System (INIS)

    Derbenev, Ya.S.; Kondratenko, A.M.; Serednyakov, S.I.; Skrinskij, A.N.; Tumajkin, G.M.; Shatunov, Yu.M.

    1977-01-01

    Experiments with polarized beams on the VEPP-2M and SPEAK storage rings are described. Possible methods of producing polarized particle beams in storage rings as well as method of polarization monitoring are counted. Considered are the processes of radiation polarization of electrons and positrons. It is shown, that to preserve radiation polarization the introduction of regions with a strong sign-variable magnetic field is recommended. Methods of polarization measurement are counted. It is suggested for high energies to use dependence of synchrotron radiation power on transverse polarization of electrons and positrons. Examples of using polarizability of colliding beams in storage rings are presented

  18. Polarized electrons at Jefferson laboratory

    International Nuclear Information System (INIS)

    Sinclair, C.K.

    1998-01-01

    The CEBAF accelerator at Jefferson laboratory can deliver CW electron beams to three experimental halls simultaneously. A large fraction of the approved scientific program at the lab requires polarized electron beams. Many of these experiments, both polarized and unpolarized, require high average beam current as well. Since all electrons delivered to the experimental halls originate from the same cathode, delivery of polarized beam to a single hall requires using the polarized source to deliver beam to all experiments in simultaneous operation. The polarized source effort at Jefferson Lab is directed at obtaining very long polarized source operational lifetimes at high average current and beam polarization; at developing the capability to deliver all electrons leaving the polarized source to the experimental halls; and at delivering polarized beam to multiple experimental halls simultaneously. Initial operational experience with the polarized source will be presented. copyright 1998 American Institute of Physics

  19. Polarized Electrons at Jefferson Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Sinclair, C.K.

    1997-12-31

    The CEBAF accelerator at Jefferson laboratory can deliver CW electron beams to three experimental halls simultaneously. A large fraction of the approved scientific program at the lab requires polarized electron beams. Many of these experiments, both polarized and unpolarized, require high average beam current as well. Since all electrons delivered to the experimental halls originate from the same cathode, delivery of polarized beam to a single hall requires using the polarized source to deliver beam to all experiments in simultaneous operation. The polarized source effort at Jefferson Lab is directed at obtaining very long polarized source operational lifetimes at high average current and beam polarization; at developing the capability to deliver all electrons leaving the polarized source to the experimental halls; and at delivering polarized beam to multiple experimental halls simultaneously.initial operational experience with the polarized source will be presented.

  20. Polarization: A Must for Fusion

    Directory of Open Access Journals (Sweden)

    Guidal M.

    2012-10-01

    Full Text Available Recent realistic simulations confirm that the polarization of the fuel would improve significantly the DT fusion efficiency. We have proposed an experiment to test the persistence of the polarization in a fusion process, using a terawatt laser hitting a polarized HD target. The polarized deuterons heated in the plasma induced by the laser can fuse producing a 3He and a neutron in the final state. The angular distribution of the neutrons and the change in the corresponding total cross section are related to the polarization persistence. The experimental polarization of DT fuel is a technological challenge. Possible paths for Magnetic Confinement Fusion (MCF and for Inertial Confinement Fusion (ICF are reviewed. For MCF, polarized gas can be used. For ICF, cryogenic targets are required. We consider both, the polarization of gas and the polarization of solid DT, emphasizing the Dynamic Nuclear polarization (DNP of HD and DT molecules.

  1. Process for the separation of contaminant or mixture of contaminants from a Ch4-comprising gaseous feed streem

    NARCIS (Netherlands)

    2012-01-01

    The invention provides a process for the separation of a contaminant or mixture of contaminants from a CH4-comprising gaseous feed streem, comprising the subsequent steps of: a) passing a CH4-comprising gaseous feed streem comprising the contaminant or the mixture of contaminants in to and through a

  2. Current lipid extraction methods are significantly enhanced adding a water treatment step in Chlorella protothecoides.

    Science.gov (United States)

    Ren, Xiaojie; Zhao, Xinhe; Turcotte, François; Deschênes, Jean-Sébastien; Tremblay, Réjean; Jolicoeur, Mario

    2017-02-11

    Microalgae have the potential to rapidly accumulate lipids of high interest for the food, cosmetics, pharmaceutical and energy (e.g. biodiesel) industries. However, current lipid extraction methods show efficiency limitation and until now, extraction protocols have not been fully optimized for specific lipid compounds. The present study thus presents a novel lipid extraction method, consisting in the addition of a water treatment of biomass between the two-stage solvent extraction steps of current extraction methods. The resulting modified method not only enhances lipid extraction efficiency, but also yields a higher triacylglycerols (TAG) ratio, which is highly desirable for biodiesel production. Modification of four existing methods using acetone, chloroform/methanol (Chl/Met), chloroform/methanol/H 2 O (Chl/Met/H 2 O) and dichloromethane/methanol (Dic/Met) showed respective lipid extraction yield enhancement of 72.3, 35.8, 60.3 and 60.9%. The modified acetone method resulted in the highest extraction yield, with 68.9 ± 0.2% DW total lipids. Extraction of TAG was particularly improved with the water treatment, especially for the Chl/Met/H 2 O and Dic/Met methods. The acetone method with the water treatment led to the highest extraction level of TAG with 73.7 ± 7.3 µg/mg DW, which is 130.8 ± 10.6% higher than the maximum value obtained for the four classical methods (31.9 ± 4.6 µg/mg DW). Interestingly, the water treatment preferentially improved the extraction of intracellular fractions, i.e. TAG, sterols, and free fatty acids, compared to the lipid fractions of the cell membranes, which are constituted of phospholipids (PL), acetone mobile polar lipids and hydrocarbons. Finally, from the 32 fatty acids analyzed for both neutral lipids (NL) and polar lipids (PL) fractions, it is clear that the water treatment greatly improves NL-to-PL ratio for the four standard methods assessed. Water treatment of biomass after the first solvent extraction step

  3. Ion dynamics in cationic lipid bilayer systems in saline solutions

    DEFF Research Database (Denmark)

    Miettinen, Markus S; Gurtovenko, Andrey A; Vattulainen, Ilpo

    2009-01-01

    Positively charged lipid bilayer systems are a promising class of nonviral vectors for safe and efficient gene and drug delivery. Detailed understanding of these systems is therefore not only of fundamental but also of practical biomedical interest. Here, we study bilayers comprising a binary...... are concluded to be interesting for the physics of the whole membrane, especially considering its interaction dynamics with charged macromolecular surfaces....

  4. Study by polarized muon

    International Nuclear Information System (INIS)

    Yamazaki, Toshimitsu

    1977-01-01

    Experiments by using polarized muon beam are reported. The experiments were performed at Berkeley, U.S.A., and at Vancouver, Canada. The muon spin rotation is a useful method for the study of the spin polarization of conductive electrons in paramagnetic Pd metal. The muon Larmor frequency and the relaxation time can be obtained by measuring the time distribution of decay electrons of muon-electron process. The anomalous depolarization of negative muon spin rotation in the transitional metal was seen. The circular polarization of the negative muon X-ray was measured to make clear this phenomena. The experimental results show that the anomalous depolarization is caused at the 1-S-1/2 state. For the purpose to obtain the strong polarization of negative muon, a method of artificial polarization is proposed, and the test experiments are in progress. The study of the hyperfine structure of mu-mesic atoms is proposed. The muon capture rate was studied systematically. (Kato, T.)

  5. Polarized protons at RHIC

    International Nuclear Information System (INIS)

    Tannenbaum, M.J.

    1990-12-01

    The Physics case is presented for the use of polarized protons at RHIC for one or two months each year. This would provide a facility with polarizations of approx-gt 50% high luminosity ∼2.0 x 10 32 cm -2 s -1 , the possibility of both longitudinal and transverse polarization at the interaction regions, and frequent polarization reversal for control of systematic errors. The annual integrated luminosity for such running (∼10 6 sec per year) would be ∫ Ldt = 2 x 10 38 cm -2 -- roughly 20 times the total luminosity integrated in ∼ 10 years of operation of the CERN Collider (∼10 inverse picobarns, 10 37 cm -2 ). This facility would be unique in the ability to perform parity-violating measurements and polarization test of QCD. Also, the existence of p-p collisions in a new energy range would permit the study of ''classical'' reactions like the total cross section and elastic scattering, etc., and serve as a complement to measurements from p-bar p colliders. 11 refs

  6. The Bochum Polarized Target

    International Nuclear Information System (INIS)

    Reicherz, G.; Goertz, S.; Harmsen, J.; Heckmann, J.; Meier, A.; Meyer, W.; Radtke, E.

    2001-01-01

    The Bochum 'Polarized Target' group develops the target material 6 LiD for the COMPASS experiment at CERN. Several different materials like alcohols, alcanes and ammonia are under investigation. Solid State Targets are polarized in magnetic fields higher than B=2.5T and at temperatures below T=1K. For the Dynamic Nuclear Polarization process, paramagnetic centers are induced chemically or by irradiation with ionizing beams. The radical density is a critical factor for optimization of polarization and relaxation times at adequate magnetic fields and temperatures. In a high sensitive EPR--apparatus, an evaporator and a dilution cryostat with a continuous wave NMR--system, the materials are investigated and optimized. To improve the polarization measurement, the Liverpool NMR-box is modified by exchanging the fixed capacitor for a varicap diode which not only makes the tuning very easy but also provides a continuously tuned circuit. The dependence of the signal area upon the circuit current is measured and it is shown that it follows a linear function

  7. Instrument comprising a cable or tube provided provided with a propulsion device

    NARCIS (Netherlands)

    Breedveld, P.

    2006-01-01

    The invention relates to an instrument (1) comprising a cable or tube (3), at a distal end of which a propulsion device (4) is provided for moving the cable or tube in a hollow space, the propulsion device being shaped like a donut lying in a plane at right angles to the longitudinal direction of

  8. Optical device comprising a cantilever and method of fabrication and use thereof

    NARCIS (Netherlands)

    Iannuzzi, Davide; Deladi, S.; Elwenspoek, Michael Curt

    2008-01-01

    The present invention provides an optical device, comprising an optical fiber and a cantilever that is arranged on an end of the optical fiber; The cantilever may be an integral part of the optical fiber, and may have a length that is substantially equal to a diameter of the optical fiber.

  9. Optical device comprising a cantilever and method of fabrication and use thereof

    NARCIS (Netherlands)

    Iannuzzi, Davide; Deladi, S.; Elwenspoek, Michael Curt

    2011-01-01

    The present invention provides an optical device, comprising an optical fiber and a cantilever that is arranged on an end of the optical fiber; The cantilever may be an integral part of the optical fiber, and may have a length that is substantially equal to a diameter of the optical fiber.

  10. Photomlxer for terahertz electromagnetic wave emission comprising quantum dots in a laser cavity

    DEFF Research Database (Denmark)

    2013-01-01

    The present invention relates to a photomixer for generating terahertz electromagnetic radiation in response to illumination by a time-modulated optical signal. The photomixer (300) comprises a carrier substrate (310) with a plurality of quantum dots arranged in an emission region (308) thereof...

  11. Light source comprising a common substrate, a first led device and a second led device

    Science.gov (United States)

    Choong, Vi-En

    2010-02-23

    At least one stacked organic or polymeric light emitting diode (PLEDs) devices to comprise a light source is disclosed. At least one of the PLEDs includes a patterned cathode which has regions which transmit light. The patterned cathodes enable light emission from the PLEDs to combine together. The light source may be top or bottom emitting or both.

  12. Hydroformylation catalyst comprising a complex with ligands having a structure derived from bisphenol A

    NARCIS (Netherlands)

    2002-01-01

    Ethylenically unsaturated compounds are hydroformylated in the presence of a hydroformylation catalyst comprising at least one complex of a metal of transition group VIII with at least one phosphorus-containing compound as ligand, where this compound contains two groups which contain P atoms and are

  13. Structural and biophysical characterization of an antimicrobial peptide chimera comprised of lactoferricin and lactoferrampin

    NARCIS (Netherlands)

    Haney, E.F.; Nazmi, K.; Bolscher, J.G.M.; Vogel, H.J.

    2012-01-01

    Lactoferricin and lactoferrampin are two antimicrobial peptides found in the N-terminal lobe of bovine lactoferrin with broad spectrum antimicrobial activity against a range of Gram-positive and Gram-negative bacteria as well as Candida albicans. A heterodimer comprised of lactoferrampin joined to a

  14. Compositions and methods comprising cellulase variants with reduced affinity to non-cellulosic materials

    Energy Technology Data Exchange (ETDEWEB)

    Cascao-Pereira, Luis; Kaper, Thijs; Kelemen, Bradley R.; Liu, Amy D.

    2017-07-04

    The present disclosure relates to cellulase variants. In particular the present disclosure relates to cellulase variants having reduced binding to non-cellulosic materials. Also described are nucleic acids encoding the cellulase, compositions comprising said cellulase, methods of identifying cellulose variants and methods of using the compositions.

  15. Compositions and methods comprising cellulase variants with reduced affinity to non-cellulosic materials

    Science.gov (United States)

    Cascao-Pereira, Luis G.; Kaper, Thijs; Kelemen, Bradley R; Liu, Amy D.

    2012-08-07

    The present disclosure relates to cellulase variants. In particular the present disclosure relates to cellulase variants having reduced binding to non-cellulosic materials. Also described are nucleic acids encoding the cellulase, compositions comprising said cellulase, methods of identifying cellulose variants and methods of using the compositions.

  16. Compositions and methods comprising cellulase variants with reduced affinity to non-cellulosic materials

    Energy Technology Data Exchange (ETDEWEB)

    Cascao-Pereira, Luis G; Kaper, Thijs; Kelemen, Bradley R; Liu, Amy D

    2015-04-07

    The present disclosure relates to cellulase variants. In particular the present disclosure relates to cellulase variants having reduced binding to non-cellulosic materials. Also described are nucleic acids encoding the cellulase, compositions comprising said cellulase, methods of identifying cellulose variants and methods of using the compositions.

  17. Semiconductor sensor device, diagnostic instrument comprising such a device and method of manufacturing such a device

    NARCIS (Netherlands)

    2010-01-01

    The invention relates to a semiconductor sensor device (10) for sensing a substance comprising at least one mesa- shaped semiconductor region (11) which is formed on a surface of a semiconductor body (12) and which is connected at a first end to a first electrically conducting connection region (13)

  18. Nanoscale Cross-Point Resistive Switching Memory Comprising p-Type SnO Bilayers

    KAUST Repository

    Hota, Mrinal Kanti; Hedhili, Mohamed N.; Wang, Qingxiao; Melnikov, Vasily; Mohammed, Omar F.; Alshareef, Husam N.

    2015-01-01

    Reproducible low-voltage bipolar resistive switching is reported in bilayer structures of p-type SnO films. Specifically, a bilayer homojunction comprising SnOx (oxygen-rich) and SnOy (oxygen-deficient) in nanoscale cross-point (300 × 300 nm2

  19. X-ray diffraction device comprising cooling medium connections provided on the x-ray tube

    NARCIS (Netherlands)

    1996-01-01

    An X-ray diffraction device comprises a water-cooled X-ray tube which exhibits a line focus as well as, after rotation through 90 DEG , a point focus. Contrary to customary X-ray tubes, the cooling water is not supplied via the housing (12) in which the X-ray tube is mounted, but the cooling water

  20. Coordinated operation of a neighborhood of smart households comprising electric vehicles, energy storage and distributed generation

    NARCIS (Netherlands)

    Paterakis, N.G.; Erdinc, O.; Pappi, I.N.; Bakirtzis, A.G.; Catalao, J.P.S.

    2016-01-01

    In this paper, the optimal operation of a neighborhood of smart households in terms of minimizing the total energy procurement cost is analyzed. Each household may comprise several assets such as electric vehicles, controllable appliances, energy storage and distributed generation. Bi-directional

  1. Polymer foam comprising a polymer and nanoparticles, and nanoparticles for the manufacture of such foam.

    NARCIS (Netherlands)

    Vancso, Gyula J.; Duvigneau, Joost; Nederkoorn, P.H.J.; Wassing, T.

    2014-01-01

    A polymer foam is produced comprising a polymer and nanoparticles having a maximum dimensionof 750 nm, which foam has cells with an average cell size of at most 1 µm and a cell density of at least 1012 cells/ml, wherein polymeric grafts have been attached to the nanoparticles. The nanoparticles may

  2. Combination Comprising Parthenolide For Use In The Treatment Of Alzheimer's Disease And Other Neurodegenerative Disorders

    KAUST Repository

    Bajic, Vladimir B.

    2015-06-18

    The present invention generally concerns particular methods and compositions for treatment of a neurodegenerative disease, such as Alzheimer\\'s Disease. In particular embodiments, there is a composition comprising Parthenolide and a second agent, including an inhibitor of TLR4/MD-2/CD14, nAChR agonist, Resatorvid, Curcumin, Tilorone or a Tilorone analog, or a combination thereof.

  3. Unraveling lipid metabolism in lipid-dependent pathogenic Malassezia yeasts

    OpenAIRE

    Celis Ramirez, A.M.

    2017-01-01

    Malassezia yeasts are lipid-dependent fungal species that are common members of the human and animal skin microbiota. The lipid-dependency is a crucial trait in the adaptation process to grow on the skin but also plays a role in their pathogenic life style. Malassezia species can cause several skin infections like dandruff or seborrheic dermatitis but also bloodstream infections. Understanding the lipid metabolism in Malassezia is essential to understand its life style as skin commensal and p...

  4. Solvent Extraction and Characterization of Neutral Lipids in Oocystis sp.

    Directory of Open Access Journals (Sweden)

    Renil eAnthony

    2015-01-01

    Full Text Available Microalgae are a favorable feedstock for bioproducts and biofuels due to their high oil content, fast growth rates and low resource demands. Solvent lipid extraction efficiency from microalgae is dependent on algal strain and the extraction solvent. Four non-polar extraction solvents were evaluated for the recovery of neutral cellular lipids from microalgae Oocystis sp. (UTEX LB2396. Methylene chloride, hexane, diethyl ether, and cyclohexane were selected as the extraction solvents. All solvent extracts contained hexadecanoic acid, linoleic acid and linolenic acid; accounting for 70% of total lipid content with a proportional wt% composition of the three fatty acids, except for the hexane extracts that showed only hexadecanoic acid and linoleic acid. While not statistically differentiated, methylene chloride proved to be the most effective solvent for Oocystis sp. among the four solvents tested with a total average neutral lipid recovery of 0.25% of dry weight followed by diethyl ether (0.18%, cyclohexane (0.14% and hexane (0.11%. This research presents a simple methodology to optimize the selection of lipid specific extraction solvents for the microalgal strain selected.

  5. A layer model of ethanol partitioning into lipid membranes.

    Science.gov (United States)

    Nizza, David T; Gawrisch, Klaus

    2009-06-01

    The effect of membrane composition on ethanol partitioning into lipid bilayers was assessed by headspace gas chromatography. A series of model membranes with different compositions have been investigated. Membranes were exposed to a physiological ethanol concentration of 20 mmol/l. The concentration of membranes was 20 wt% which roughly corresponds to values found in tissue. Partitioning depended on the chemical nature of polar groups at the lipid/water interface. Compared to phosphatidylcholine, lipids with headgroups containing phosphatidylglycerol, phosphatidylserine, and sphingomyelin showed enhanced partitioning while headgroups containing phosphatidylethanolamine resulted in a lower partition coefficient. The molar partition coefficient was independent of a membrane's hydrophobic volume. This observation is in agreement with our previously published NMR results which showed that ethanol resides almost exclusively within the membrane/water interface. At an ethanol concentration of 20 mmol/l in water, ethanol concentrations at the lipid/water interface are in the range from 30-15 mmol/l, corresponding to one ethanol molecule per 100-200 lipids.

  6. Lipids of the ultra-thin square halophilic archaeon Haloquadratum walsbyi

    Directory of Open Access Journals (Sweden)

    Simona LoBasso

    2008-01-01

    Full Text Available The lipid composition of the extremely halophilic archaeon Haloquadratum walsbyi was investigated by thin-layer chromatography and electrospray ionization-mass spectrometry. The analysis of neutral lipids showed the presence of vitamin MK-8, squalene, carotene, bacterioruberin and several retinal isomers. The major polar lipids were phosphatidylglycerophosphate methyl ester, phosphatidylglycerosulfate, phosphatidylglycerol and sulfated diglycosyl diether lipid. Among cardiolipins, the tetra-phytanyl or dimeric phospholipids, only traces of bisphosphatidylglycerol were detected. When the cells were exposed to hypotonic medium, no changes in the membrane lipid composition occurred. Distinguishing it from other extreme halophiles of the Halobacteriaceae family, the osmotic stress did not induce the neo-synthesis of cardiolipins in H. walsbyi. The difference may depend on the three-laminar structure of the cell wall, which differs significantly from that of other Haloarchaea.

  7. Lipids and Fatty Acids in Algae: Extraction, Fractionation into Lipid Classes, and Analysis by Gas Chromatography Coupled with Flame Ionization Detector (GC-FID).

    Science.gov (United States)

    Guihéneuf, Freddy; Schmid, Matthias; Stengel, Dagmar B

    2015-01-01

    Despite the number of biochemical studies exploring algal lipids and fatty acid biosynthesis pathways and profiles, analytical methods used by phycologists for this purpose are often diverse and incompletely described. Potential confusion and potential variability of the results between studies can therefore occur due to change of protocols for lipid extraction and fractionation, as well as fatty acid methyl esters (FAME) preparation before gas chromatography (GC) analyses. Here, we describe a step-by-step procedure for the profiling of neutral and polar lipids using techniques such as solid-liquid extraction (SLE), thin-layer chromatography (TLC), and gas chromatography coupled with flame ionization detector (GC-FID). As an example, in this protocol chapter, analyses of neutral and polar lipids from the marine microalga Pavlova lutheri (an EPA/DHA-rich haptophyte) will be outlined to describe the distribution of fatty acid residues within its major lipid classes. This method has been proven to be a reliable technique to assess changes in lipid and fatty acid profiles in several other microalgal species and seaweeds.

  8. Polarized source upgrading

    International Nuclear Information System (INIS)

    Clegg, T.B.; Rummel, R.L.; Carter, E.P.; Westerfeldt, C.R.; Lovette, A.W.; Edwards, S.E.

    1985-01-01

    The decision was made this past year to move the Lamb-shift polarized ion source which was first installed in the laboratory in 1970. The motivation was the need to improve the flexibility of spin-axis orientation by installing the ion source with a new Wien-filter spin precessor which is capable of rotating physically about the beam axis. The move of the polarized source was accomplished in approximately two months, with the accelerator being turned off for experiments during approximately four weeks of this time. The occasion of the move provided the opportunity to rewire completely the entire polarized ion source frame and to rebuild approximately half of the electronic chassis on the source. The result is an ion source which is now logically wired and carefully documented. Beams obtained from the source are much more stable than those previously available

  9. Spin polarized deuterium

    International Nuclear Information System (INIS)

    Glyde, H.R.; Hernadi, S.I.

    1986-01-01

    Several ground state properties of (electron) spin-polarized deuterium (D) such as the energy, single quasiparticle energies and lifetimes, Landau parameters and sound velocities are evaluated. The calculations begin with the Kolos-Wolneiwicz potential and use the Galitskii-FeynmanHartree-Fock (GFHF) approximation. The deuteron nucleas has spin I = 1, and spin states I/sub z/ = 1,0,-1. We explore D 1 , D 2 and D 3 in which, respectively, one spin state only is populated, two states are equally populated, and three states are equally populated. We find the GFHF describes D 1 well, but D 2 and D 3 less well. The Landau parameters, F/sub L/, are small compared to liquid 3 He and very small for doubly polarized D 1 (i.e. the F/sub L/ decrease with nuclear polarization)

  10. Polarized electron sources

    International Nuclear Information System (INIS)

    Clendenin, J.E.

    1995-05-01

    Polarized electron sources for high energy accelerators took a significant step forward with the introduction of a new laser-driven photocathode source for the SLC in 1992. With an electron beam polarization of >80% and with ∼99% uptime during continuous operation, this source is a key factor in the success of the current SLC high-energy physics program. The SLC source performance is used to illustrate both the capabilities and the limitations of solid-state sources. The beam requirements for future colliders are similar to that of the SLC with the addition in most cases of multiple-bunch operation. A design for the next generation accelerator source that can improve the operational characteristics and at least minimize some of the inherent limitations of present sources is presented. Finally, the possibilities for producing highly polarized electron beams for high-duty-factor accelerators are discussed

  11. Time Domain Induced Polarization

    DEFF Research Database (Denmark)

    Fiandaca, Gianluca; Auken, Esben; Christiansen, Anders Vest

    2012-01-01

    Time-domain-induced polarization has significantly broadened its field of reference during the last decade, from mineral exploration to environmental geophysics, e.g., for clay and peat identification and landfill characterization. Though, insufficient modeling tools have hitherto limited the use...... of time-domaininduced polarization for wider purposes. For these reasons, a new forward code and inversion algorithm have been developed using the full-time decay of the induced polarization response, together with an accurate description of the transmitter waveform and of the receiver transfer function......, to reconstruct the distribution of the Cole-Cole parameters of the earth. The accurate modeling of the transmitter waveform had a strong influence on the forward response, and we showed that the difference between a solution using a step response and a solution using the accurate modeling often is above 100...

  12. A lunar polar expedition

    Science.gov (United States)

    Dowling, Richard; Staehle, Robert L.; Svitek, Tomas

    1992-09-01

    Advanced exploration and development in harsh environments require mastery of basic human survival skill. Expeditions into the lethal climates of Earth's polar regions offer useful lessons for tommorrow's lunar pioneers. In Arctic and Antarctic exploration, 'wintering over' was a crucial milestone. The ability to establish a supply base and survive months of polar cold and darkness made extensive travel and exploration possible. Because of the possibility of near-constant solar illumination, the lunar polar regions, unlike Earth's may offer the most hospitable site for habitation. The World Space Foundation is examining a scenario for establishing a five-person expeditionary team on the lunar north pole for one year. This paper is a status report on a point design addressing site selection, transportation, power, and life support requirements.

  13. Probing lipid membrane electrostatics

    Science.gov (United States)

    Yang, Yi

    The electrostatic properties of lipid bilayer membranes play a significant role in many biological processes. Atomic force microscopy (AFM) is highly sensitive to membrane surface potential in electrolyte solutions. With fully characterized probe tips, AFM can perform quantitative electrostatic analysis of lipid membranes. Electrostatic interactions between Silicon nitride probes and supported zwitterionic dioleoylphosphatidylcholine (DOPC) bilayer with a variable fraction of anionic dioleoylphosphatidylserine (DOPS) were measured by AFM. Classical Gouy-Chapman theory was used to model the membrane electrostatics. The nonlinear Poisson-Boltzmann equation was numerically solved with finite element method to provide the potential distribution around the AFM tips. Theoretical tip-sample electrostatic interactions were calculated with the surface integral of both Maxwell and osmotic stress tensors on tip surface. The measured forces were interpreted with theoretical forces and the resulting surface charge densities of the membrane surfaces were in quantitative agreement with the Gouy-Chapman-Stern model of membrane charge regulation. It was demonstrated that the AFM can quantitatively detect membrane surface potential at a separation of several screening lengths, and that the AFM probe only perturbs the membrane surface potential by external field created by the internai membrane dipole moment. The analysis yields a dipole moment of 1.5 Debye per lipid with a dipole potential of +275 mV for supported DOPC membranes. This new ability to quantitatively measure the membrane dipole density in a noninvasive manner will be useful in identifying the biological effects of the dipole potential. Finally, heterogeneous model membranes were studied with fluid electric force microscopy (FEFM). Electrostatic mapping was demonstrated with 50 nm resolution. The capabilities of quantitative electrostatic measurement and lateral charge density mapping make AFM a unique and powerful

  14. Non-polar lipids characterization of Quinoa (Chenopodium quinoa) seed by comprehensive two-dimensional gas chromatography with flame ionization/mass spectrometry detection and non-aqueous reversed-phase liquid chromatography with atmospheric pressure chemical ionization mass spectrometry detection.

    Science.gov (United States)

    Fanali, Chiara; Beccaria, Marco; Salivo, Simona; Tranchida, Peter; Tripodo, Giusy; Farnetti, Sara; Dugo, Laura; Dugo, Paola; Mondello, Luigi

    2015-07-08

    A chemical characterization of major lipid components, namely, triacylglycerols, fatty acids and the unsaponifiable fraction, in a Quinoa seed lipids sample is reported. To tackle such a task, non-aqueous reversed-phase high-performance liquid chromatography with mass spectrometry detection was employed. The latter was interfaced with atmospheric pressure chemical ionization for the analysis of triacylglycerols. The main triacylglycerols (>10%) were represented by OLP, OOL and OLL (P = palmitoyl, O = oleoyl, L = linoleoyl); the latter was present in the oil sample at the highest percentage (18.1%). Furthermore, fatty acid methyl esters were evaluated by gas chromatography with flame ionization detection. 89% of the total fatty acids was represented by unsaturated fatty acid methyl esters with the greatest percentage represented by linoleic and oleic acids accounting for approximately 48 and 28%, respectively. An extensive characterization of the unsaponifiable fraction of Quinoa seed lipids was performed for the first time, by using comprehensive two-dimensional gas chromatography with dual mass spectrometry/flame ionization detection. Overall, 66 compounds of the unsaponifiable fraction were tentatively identified, many constituents of which (particularly sterols) were confirmed by using gas chromatography with high-resolution time-of-flight mass spectrometry. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Subcellular localization of secondary lipid metabolites including fragrance volatiles in carnation petals

    International Nuclear Information System (INIS)

    Hudak, K.A.; Thompson, J.E.

    1997-01-01

    Pulse-chase labeling of carnation (Dianthus caryophyllus L. cv Improved White Sim) petals with [14C]acetate has provided evidence for a hydrophobic subcompartment of lipid-protein particles within the cytosol that resemble oil bodies, are formed by blebbing from membranes, and are enriched in lipid metabolites (including fragrance volatiles) derived from membrane fatty acids. Fractionation of the petals during pulse-chase labeling revealed that radiolabeled fatty acids appear first in microsomal membranes and subsequently in cytosolic lipid-protein particles, indicating that the particles originate from membranes. This interpretation is supported by the finding that the cytosolic lipid-protein particles contain phospholipid as well as the same fatty acids found in microsomal membranes. Radiolabeled polar lipid metabolites (methanol/ water-soluble) were detectable in both in situ lipid-protein particles isolated from the cytosol and those generated in vitro from isolated radiolabeled microsomal membranes. The lipid-protein particles were also enriched in hexanal, trans-2-hexenal, 1-hexanol, 3-hexen-1-ol, and 2-hexanol, volatiles of carnation flower fragrance that are derived from membrane fatty acids through the lipoxygenase pathway. Therefore, secondary lipid metabolites, including components of fragrance, appear to be formed within membranes of petal tissue and are subsequently released from the membrane bilayers into the cytosol by blebbing of lipid-protein particles

  16. Lipoproteins in Drosophila melanogaster—Assembly, Function, and Influence on Tissue Lipid Composition

    Science.gov (United States)

    Palm, Wilhelm; Sampaio, Julio L.; Brankatschk, Marko; Carvalho, Maria; Mahmoud, Ali; Shevchenko, Andrej; Eaton, Suzanne

    2012-01-01

    Interorgan lipid transport occurs via lipoproteins, and altered lipoprotein levels correlate with metabolic disease. However, precisely how lipoproteins affect tissue lipid composition has not been comprehensively analyzed. Here, we identify the major lipoproteins of Drosophila melanogaster and use genetics and mass spectrometry to study their assembly, interorgan trafficking, and influence on tissue lipids. The apoB-family lipoprotein Lipophorin (Lpp) is the major hemolymph lipid carrier. It is produced as a phospholipid-rich particle by the fat body, and its secretion requires Microsomal Triglyceride Transfer Protein (MTP). Lpp acquires sterols and most diacylglycerol (DAG) at the gut via Lipid Transfer Particle (LTP), another fat body-derived apoB-family lipoprotein. The gut, like the fat body, is a lipogenic organ, incorporating both de novo–synthesized and dietary fatty acids into DAG for export. We identify distinct requirements for LTP and Lpp-dependent lipid mobilization in contributing to the neutral and polar lipid composition of the brain and wing imaginal disc. These studies define major routes of interorgan lipid transport in Drosophila and uncover surprising tissue-specific differences in lipoprotein lipid utilization. PMID:22844248

  17. Modelling Polar Self Assembly

    Science.gov (United States)

    Olvera de La Cruz, Monica; Sayar, Mehmet; Solis, Francisco J.; Stupp, Samuel I.

    2001-03-01

    Recent experimental studies in our group have shown that self assembled thin films of noncentrosymmetric supramolecular objects composed of triblock rodcoil molecules exhibit finite polar order. These aggregates have both long range dipolar and short range Ising-like interactions. We study the ground state of a simple model with these competing interactions. We find that the competition between Ising-like and dipolar forces yield a periodic domain structure, which can be controlled by adjusting the force constants and film thickness. When the surface forces are included in the potential, the system exhibits a finite macroscopic polar order.

  18. AGS polarized H- source

    International Nuclear Information System (INIS)

    Kponou, A.; Alessi, J.G.; Sluyters, T.

    1985-01-01

    The AGS polarized H - source is now operational. During a month-long experimental physics run in July 1984, pulses equivalent to 15 μA x 300 μs (approx. 3 x 10 10 protons) were injected into the RFQ preaccelerator. Beam polarization, measured at 200 MeV, was approx. 75%. After the run, a program to increase the H - yield of the source was begun and significant progress has been made. The H - current is now frequently 20 to 30 μA. A description of the source and some details of our operating experience are given. We also briefly describe the improvement program

  19. The polar mesosphere

    International Nuclear Information System (INIS)

    Morris, Ray; Murphy, Damian

    2008-01-01

    The mesosphere region, which lies at the edge of space, contains the coldest layer of the Earth's atmosphere, with summer temperatures as low as minus 130 °C. In this extreme environment ice aerosol layers have appeared since the dawn of industrialization—whose existence may arguably be linked to human influence—on yet another layer of the Earth's fragile atmosphere. Ground-based and space-based experiments conducted in the Arctic and Antarctic during the International Polar Year (IPY) aim to address limitations in our knowledge and to advance our understanding of thermal and dynamical processes at play in the polar mesosphere

  20. Imaging with Polarized Neutrons

    Directory of Open Access Journals (Sweden)

    Nikolay Kardjilov

    2018-01-01

    Full Text Available Owing to their zero charge, neutrons are able to pass through thick layers of matter (typically several centimeters while being sensitive to magnetic fields due to their intrinsic magnetic moment. Therefore, in addition to the conventional attenuation contrast image, the magnetic field inside and around a sample can be visualized by detecting changes of polarization in a transmitted beam. The method is based on the spatially resolved measurement of the cumulative precession angles of a collimated, polarized, monochromatic neutron beam that traverses a magnetic field or sample.

  1. Polarization splitter and polarization rotator designs based on transformation optics.

    Science.gov (United States)

    Kwon, Do-Hoon; Werner, Douglas H

    2008-11-10

    The transformation optics technique is employed in this paper to design two optical devices - a two-dimensional polarization splitter and a three-dimensional polarization rotator for propagating beams. The polarization splitter translates the TM- and the TE-polarized components of an incident beam in opposite directions (i.e., shifted up or shifted down). The polarization rotator rotates the polarization state of an incoming beam by an arbitrary angle. Both optical devices are reflectionless at the entry and exit interfaces. Design details and full-wave simulation results are provided.

  2. Thermodynamic and fluorescence studies of the underlying factors in benzyl alcohol-induced lipid interdigitated phase.

    Science.gov (United States)

    Chen, C H; Hoye, K; Roth, L G

    1996-09-15

    To further investigate factors contributing to the action of alcohol in the solute-induced lipid interdigitation phase, thermodynamic and fluorescence polarization measurements were carried out to study the interaction of benzyl alcohol with dipalmitoyl phosphatidylcholine bilayer vesicles. The obtained results were compared with those previously reported for ethanol and cyclohexanol (L. G. Roth and C-H. Chen, Arch. Biochem. Biophys. 296, 207, 1992). Similar to ethanol, benzyl alcohol was found to exhibit a biphasic effect on the enthalpy (delta Hm) and the temperature (tm) of the lipid-phase transition and the steady-state fluorescence polarization (P) monitored by 1,6-diphenyl-1,3,5-hexatriene. At a total concentration of benzyl alcohol delta Hm and P, which were correlated with the formation of a lipid interdigitated phase, as evidenced by reported X-ray diffraction data. Combining the results with benzyl alcohol and ethanol suggested that simultaneously large changes in delta Hm and P can be used as an indication of the occurrence of a solute-induced lipid interdigitated phase. The overall interacting force in the formation of this lipid phase, as derived from the interactions of the hydroxyl portion of an alcohol with the lipid phosphate head group and the hydrophobic portion of an alcohol with the lipid hydrocarbon chains, may or may not be dominated by hydrophobic interaction. Although lipid/water partition coefficients and the contribution of hydrophobic interaction to the overall interacting force were comparable between benzyl alcohol and cyclohexanol, benzyl alcohol induced lipid interdigitated phase, but not for cyclohexanol. This was due to the ability of benzyl alcohol to be more effective than cyclohexanol in simultaneously interacting with the phosphate head group and the hydrocarbon chains of lipid.

  3. Membrane interaction of antimicrobial peptides using E. coli lipid extract as model bacterial cell membranes and SFG spectroscopy.

    Science.gov (United States)

    Soblosky, Lauren; Ramamoorthy, Ayyalusamy; Chen, Zhan

    2015-04-01

    Supported lipid bilayers are used as a convenient model cell membrane system to study biologically important molecule-lipid interactions in situ. However, the lipid bilayer models are often simple and the acquired results with these models may not provide all pertinent information related to a real cell membrane. In this work, we use sum frequency generation (SFG) vibrational spectroscopy to study molecular-level interactions between the antimicrobial peptides (AMPs) MSI-594, ovispirin-1 G18, magainin 2 and a simple 1,2-dipalmitoyl-d62-sn-glycero-3-phosphoglycerol (dDPPG)/1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol (POPG) bilayer. We compared such interactions to those between the AMPs and a more complex dDPPG/Escherichia coli (E. coli) polar lipid extract bilayer. We show that to fully understand more complex aspects of peptide-bilayer interaction, such as interaction kinetics, a heterogeneous lipid composition is required, such as the E. coli polar lipid extract. The discrepancy in peptide-bilayer interaction is likely due in part to the difference in bilayer charge between the two systems since highly negative charged lipids can promote more favorable electrostatic interactions between the peptide and lipid bilayer. Results presented in this paper indicate that more complex model bilayers are needed to accurately analyze peptide-cell membrane interactions and demonstrates the importance of using an appropriate lipid composition to study AMP interaction properties. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  4. Lipids and membrane lateral organization

    Directory of Open Access Journals (Sweden)

    Sandro eSonnino

    2010-11-01

    Full Text Available Shortly after the elucidation of the very basic structure and properties of cellular membranes, it became evident that cellular membranes are highly organized structures with multiple and multi-dimensional levels of order. Very early observations suggested that the lipid components of biological membranes might be active players in the creations of these levels of order. In the late 80’s, several different and diverse experimental pieces of evidence coalesced together giving rise to the lipid raft hypothesis. Lipid rafts became enormously (and, in the opinion of these authors, sometimes acritically popular, surprisingly not just within the lipidologist community (who is supposed to be naturally sensitive to the fascination of lipid rafts. Today, a PubMed search using the key word lipid rafts returned a list of 3767 papers, including 690 reviews (as a term of comparison, searching over the same time span for a very hot lipid-related key word, ceramide returned 6187 hits with 799 reviews, and a tremendous number of different cellular functions have been described as lipid raft-dependent. However, a clear consensus definition of lipid raft has been proposed only in recent times, and the basic properties, the ruling forces, and even the existence of lipid rafts in living cells have been recently matter of intense debate. The scenario that is gradually emerging from the controversies elicited by the lipid raft hypothesis emphasize multiple roles for membrane lipids in determining membrane order, that encompasses their tendency to phase separation but are clearly not limited to this. In this review, we would like to re-focus the attention of the readers on the importance of lipids in organizing the fine structure of cellular membranes.

  5. Remote biopsy darting and marking of polar bears

    Science.gov (United States)

    Pagano, Anthony M.; Peacock, Elizabeth; McKinney, Melissa A.

    2014-01-01

    Remote biopsy darting of polar bears (Ursus maritimus) is less invasive and time intensive than physical capture and is therefore useful when capture is challenging or unsafe. We worked with two manufacturers to develop a combination biopsy and marking dart for use on polar bears. We had an 80% success rate of collecting a tissue sample with a single biopsy dart and collected tissue samples from 143 polar bears on land, in water, and on sea ice. Dye marks ensured that 96% of the bears were not resampled during the same sampling period, and we recovered 96% of the darts fired. Biopsy heads with 5 mm diameters collected an average of 0.12 g of fur, tissue, and subcutaneous adipose tissue, while biopsy heads with 7 mm diameters collected an average of 0.32 g. Tissue samples were 99.3% successful (142 of 143 samples) in providing a genetic and sex identification of individuals. We had a 64% success rate collecting adipose tissue and we successfully examined fatty acid signatures in all adipose samples. Adipose lipid content values were lower compared to values from immobilized or harvested polar bears, indicating that our method was not suitable for quantifying adipose lipid content.

  6. Polarized Proton Collisions at RHIC

    CERN Document Server

    Bai, Mei; Alekseev, Igor G; Alessi, James; Beebe-Wang, Joanne; Blaskiewicz, Michael; Bravar, Alessandro; Brennan, Joseph M; Bruno, Donald; Bunce, Gerry; Butler, John J; Cameron, Peter; Connolly, Roger; De Long, Joseph; Drees, Angelika; Fischer, Wolfram; Ganetis, George; Gardner, Chris J; Glenn, Joseph; Hayes, Thomas; Hseuh Hsiao Chaun; Huang, Haixin; Ingrassia, Peter; Iriso, Ubaldo; Laster, Jonathan S; Lee, Roger C; Luccio, Alfredo U; Luo, Yun; MacKay, William W; Makdisi, Yousef; Marr, Gregory J; Marusic, Al; McIntyre, Gary; Michnoff, Robert; Montag, Christoph; Morris, John; Nicoletti, Tony; Oddo, Peter; Oerter, Brian; Osamu, Jinnouchi; Pilat, Fulvia Caterina; Ptitsyn, Vadim; Roser, Thomas; Satogata, Todd; Smith, Kevin T; Svirida, Dima; Tepikian, Steven; Tomas, Rogelio; Trbojevic, Dejan; Tsoupas, Nicholaos; Tuozzolo, Joseph; Vetter, Kurt; Wilinski, Michelle; Zaltsman, Alex; Zelenski, Anatoli; Zeno, Keith; Zhang, S Y

    2005-01-01

    The Relativistic Heavy Ion Collider~(RHIC) provides not only collisions of ions but also collisions of polarized protons. In a circular accelerator, the polarization of polarized proton beam can be partially or fully lost when a spin depolarizing resonance is encountered. To preserve the beam polarization during acceleration, two full Siberian snakes were employed in RHIC to avoid depolarizing resonances. In 2003, polarized proton beams were accelerated to 100~GeV and collided in RHIC. Beams were brought into collisions with longitudinal polarization at the experiments STAR and PHENIX by using spin rotators. RHIC polarized proton run experience demonstrates that optimizing polarization transmission efficiency and improving luminosity performance are significant challenges. Currently, the luminosity lifetime in RHIC is limited by the beam-beam effect. The current state of RHIC polarized proton program, including its dedicated physics run in 2005 and efforts to optimize luminosity production in beam-beam limite...

  7. Method and device for fabricating dispersion fuel comprising fission product collection spaces

    Science.gov (United States)

    Shaber, Eric L; Fielding, Randall S

    2015-05-05

    A method of fabricating a nuclear fuel comprising a fissile material, one or more hollow microballoons, a phenolic resin, and metal matrix. The fissile material, phenolic resin and the one or more hollow microballoons are combined. The combined fissile material, phenolic resin and the hollow microballoons are heated sufficiently to form at least some fissile material carbides creating a nuclear fuel particle. The resulting nuclear fuel particle comprises one or more fission product collection spaces. In a preferred embodiment, the fissile material, phenolic resin and the one or more hollow microballoons are combined by forming the fissile material into microspheres. The fissile material microspheres are then overcoated with the phenolic resin and microballoon. In another preferred embodiment, the fissile material, phenolic resin and the one or more hollow microballoons are combined by overcoating the microballoon with the fissile material, and phenolic resin.

  8. Energy storage systems having an electrode comprising Li.sub.xS.sub.y

    Science.gov (United States)

    Xiao, Jie; Zhang, Jiguang; Graff, Gordon L.; Liu, Jun; Wang, Wei; Zheng, Jianming; Xu, Wu; Shao, Yuyan; Yang, Zhenguo

    2016-08-02

    Improved lithium-sulfur energy storage systems can utilizes Li.sub.xS.sub.y as a component in an electrode of the system. For example, the energy storage system can include a first electrode current collector, a second electrode current collector, and an ion-permeable separator separating the first and second electrode current collectors. A second electrode is arranged between the second electrode current collector and the separator. A first electrode is arranged between the first electrode current collector and the separator and comprises a first condensed-phase fluid comprising Li.sub.xS.sub.y. The energy storage system can be arranged such that the first electrode functions as a positive or a negative electrode.

  9. Lateral acoustic wave resonator comprising a suspended membrane of low damping resonator material

    Science.gov (United States)

    Olsson, Roy H.; El-Kady; , Ihab F.; Ziaei-Moayyed, Maryam; Branch; , Darren W.; Su; Mehmet F.,; Reinke; Charles M.,

    2013-09-03

    A very high-Q, low insertion loss resonator can be achieved by storing many overtone cycles of a lateral acoustic wave (i.e., Lamb wave) in a lithographically defined suspended membrane comprising a low damping resonator material, such as silicon carbide. The high-Q resonator can sets up a Fabry-Perot cavity in a low-damping resonator material using high-reflectivity acoustic end mirrors, which can comprise phononic crystals. The lateral overtone acoustic wave resonator can be electrically transduced by piezoelectric couplers. The resonator Q can be increased without increasing the impedance or insertion loss by storing many cycles or wavelengths in the high-Q resonator material, with much lower damping than the piezoelectric transducer material.

  10. Bacterial Artificial Chromosome Clones of Viruses Comprising the Towne Cytomegalovirus Vaccine

    Directory of Open Access Journals (Sweden)

    Xiaohong Cui

    2012-01-01

    Full Text Available Bacterial artificial chromosome (BAC clones have proven invaluable for genetic manipulation of herpesvirus genomes. BAC cloning can also be useful for capturing representative genomes that comprise a viral stock or mixture. The Towne live attenuated cytomegalovirus vaccine was developed in the 1970s by serial passage in cultured fibroblasts. Although its safety, immunogenicity, and efficacy have been evaluated in nearly a thousand human subjects, the vaccine itself has been little studied. Instead, genetic composition and in vitro growth properties have been inferred from studies of laboratory stocks that may not always accurately represent the viruses that comprise the vaccine. Here we describe the use of BAC cloning to define the genotypic and phenotypic properties of viruses from the Towne vaccine. Given the extensive safety history of the Towne vaccine, these BACs provide a logical starting point for the development of next-generation rationally engineered cytomegalovirus vaccines.

  11. Bacterial artificial chromosome clones of viruses comprising the towne cytomegalovirus vaccine.

    Science.gov (United States)

    Cui, Xiaohong; Adler, Stuart P; Davison, Andrew J; Smith, Larry; Habib, El-Sayed E; McVoy, Michael A

    2012-01-01

    Bacterial artificial chromosome (BAC) clones have proven invaluable for genetic manipulation of herpesvirus genomes. BAC cloning can also be useful for capturing representative genomes that comprise a viral stock or mixture. The Towne live attenuated cytomegalovirus vaccine was developed in the 1970s by serial passage in cultured fibroblasts. Although its safety, immunogenicity, and efficacy have been evaluated in nearly a thousand human subjects, the vaccine itself has been little studied. Instead, genetic composition and in vitro growth properties have been inferred from studies of laboratory stocks that may not always accurately represent the viruses that comprise the vaccine. Here we describe the use of BAC cloning to define the genotypic and phenotypic properties of viruses from the Towne vaccine. Given the extensive safety history of the Towne vaccine, these BACs provide a logical starting point for the development of next-generation rationally engineered cytomegalovirus vaccines.

  12. Polarized coincidence electroproduction

    International Nuclear Information System (INIS)

    Heimann, R.L.

    1975-03-01

    A study is made of the inclusive electroproduction of single hadrons off a polarized target. Bjorken scaling laws and the hadron azimuthal distribution are derived from the quark parton model. The polarization asymmetries scale when the target spin is along the direction of the virtual photon, and (apart from significant exception) vanish for transverse spin. These results have a simple explanation; emphasis is given both to the general mathematical formalism and to intuitive physical reasoning. Through this framework other cases are considered: quarks with anomalous magnetic moment; renormalization group effects and asymptotic freedom; production of vector mesons (whose spin state is analysed by their decay); relation to large transverse momentum hadron production; and a covariant parton model calculation. Spin 0 partons and Regge singularities are also considered. All of these cases (apart from the last two) modify the pattern of conclusions. Vector meson production shows polarization enhancements in the density matrix element rhosub(0+); the renormalization group approach does not lead to any significant suppressions. They are also less severe in parton models for large Psub(T) hadrons, and are not supported by the covariantly formulated calculation. The origins of these differences are isolated and used to exemplify the sensitivity polarized hadron electroproduction has to delicate detail that is otherwise concealed. (author)

  13. Fluorescence confocal polarizing microscopy

    Indian Academy of Sciences (India)

    Much of the modern understanding of orientational order in liquid crystals (LCs) is based on polarizing microscopy (PM). A PM image bears only two-dimensional (2D) information, integrating the 3D pattern of optical birefringence over the path of light. Recently, we proposed a technique to image 3D director patterns by ...

  14. Optical neutron polarizers

    International Nuclear Information System (INIS)

    Hayter, J.B.

    1990-01-01

    A neutron wave will be refracted by an appropriately varying potential. Optical neutron polarizers use spatially varying, spin- dependent potentials to refract neutrons of opposite spin states into different directions, so that an unpolarized beam will be split into two beams of complementary polarization by such a device. This paper will concentrate on two methods of producing spin-dependent potentials which are particularly well-suited to polarizing cold neutron beams, namely thin-film structures and field-gradient techniques. Thin-film optical devices, such as supermirror multilayer structures, are usually designed to deviate only one spin-state, so that they offer the possibility of making insertion (transmission) polarizers. Very good supermirrors may now be designed and fabricated, but it is not always straightforward to design mirror-based devices which are useful in real (divergent beam) applications, and some practical configurations will be discussed. Field-gradient devices, which are usually based on multipolar magnets, have tended to be too expensive for general use, but this may change with new developments in superconductivity. Dipolar and hexapolar configurations will be considered, with emphasis on the focusing characteristics of the latter. 21 refs., 7 figs

  15. Titan Polar Landscape Evolution

    Science.gov (United States)

    Moore, Jeffrey M.

    2016-01-01

    With the ongoing Cassini-era observations and studies of Titan it is clear that the intensity and distribution of surface processes (particularly fluvial erosion by methane and Aeolian transport) has changed through time. Currently however, alternate hypotheses substantially differ among specific scenarios with respect to the effects of atmospheric evolution, seasonal changes, and endogenic processes. We have studied the evolution of Titan's polar region through a combination of analysis of imaging, elevation data, and geomorphic mapping, spatially explicit simulations of landform evolution, and quantitative comparison of the simulated landscapes with corresponding Titan morphology. We have quantitatively evaluated alternate scenarios for the landform evolution of Titan's polar terrain. The investigations have been guided by recent geomorphic mapping and topographic characterization of the polar regions that are used to frame hypotheses of process interactions, which have been evaluated using simulation modeling. Topographic information about Titan's polar region is be based on SAR-Topography and altimetry archived on PDS, SAR-based stereo radar-grammetry, radar-sounding lake depth measurements, and superposition relationships between geomorphologic map units, which we will use to create a generalized topographic map.

  16. The polarized EMC effect

    Energy Technology Data Exchange (ETDEWEB)

    W. Bentz; I. C. Cloet; A. W. Thomas

    2007-02-01

    We calculate both the spin independent and spin dependent nuclear structure functions in an effective quark theory. The nucleon is described as a composite quark-diquark state, and the nucleus is treated in the mean field approximation. We predict a sizable polarized EMC effect, which could be confirmed in future experiments.

  17. Polarizer reflectivity variations

    International Nuclear Information System (INIS)

    Ozarski, R.G.; Prior, J.

    1980-01-01

    On Shiva the beam energy along the chain is monitored using available reflections and/or transmission through beam steering, splitting, and polarizing optics without the intrusion of any additional glass for diagnostics. On the preamp table the diagnostic signal is obtained from the signal transmitted through turning mirrors. At the input of each chain the signal is obtained from the transmission through one of the mirrors used for the chain input alignment sensor (CHIP). At the chain output the transmission through the final turning mirror is used. These diagnostics have proved stable and reliable. However, one of the prime diagnostic locations is at the output of the beta rod. The energy at this location is measured by collecting small reflections from the last polarizer surface of the beta Pockels cell polarizer package. Unfortunately, calibration of this diagnostic has varied randomly, seldom remaining stable for a week or more. The cause of this fluctuation has been investigated for the past year and'it has been discovered that polarizer reflectivity varies with humidity. This report will deal with the possible causes that were investigated, the evidence that humidity is causing the variation, and the associated mechanism

  18. Spin-polarized photoemission

    International Nuclear Information System (INIS)

    Johnson, Peter D.

    1997-01-01

    Spin-polarized photoemission has developed into a versatile tool for the study of surface and thin film magnetism. In this review, we examine the methodology of the technique and its application to a number of different problems, including both valence band and core level studies. After a detailed review of spin-polarization measurement techniques and the related experimental requirements we consider in detail studies of the bulk properties both above and below the Curie temperature. This section also includes a discussion of observations relating to unique metastable phases obtained via epitaxial growth. The application of the technique to the study of surfaces, both clean and adsorbate covered, is reviewed. The report then examines, in detail, studies of the spin-polarized electronic structure of thin films and the related interfacial magnetism. Finally, observations of spin-polarized quantum well states in non-magnetic thin films are discussed with particular reference to their mediation of the oscillatory exchange coupling in related magnetic multilayers. (author)

  19. Polarization of Bremsstrahlung

    International Nuclear Information System (INIS)

    Miller, J.

    1957-01-01

    The numerical results for the polarization of Bremsstrahlung are presented. The multiple scattering of electrons in the target is taken into account. The angular-and photon energy dependences are seen on the curves for an incident 25 MeV electron energy. (Author) [fr

  20. No More Polarization, Please!

    DEFF Research Database (Denmark)

    Hansen, Mia Reinholt

    and the increasing levels of complexities it entails, such polarization is not fruitful in the attempt to explain motivation of organizational members. This paper claims that a more nuanced perspective on motivation, acknowledging the co-existence of intrinsic and extrinsic motivation, the possible interaction...

  1. DESY: HERA polarization

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    The new HERA electron-proton collider at DESY in Hamburg achieved the first luminosity for electron-proton collisions on 19 October last year. Only one month later, on 20 November, HERA passed another important milestone with the observation of transverse electron polarization

  2. Polarized Neutron Scattering

    OpenAIRE

    Roessli, B.; Böni, P.

    2000-01-01

    The technique of polarized neutron scattering is reviewed with emphasis on applications. Many examples of the usefulness of the method in various fields of physics are given like the determination of spin density maps, measurement of complex magnetic structures with spherical neutron polarimetry, inelastic neutron scattering and separation of coherent and incoherent scattering with help of the generalized XYZ method.

  3. DESY: HERA polarization

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1992-03-15

    The new HERA electron-proton collider at DESY in Hamburg achieved the first luminosity for electron-proton collisions on 19 October last year. Only one month later, on 20 November, HERA passed another important milestone with the observation of transverse electron polarization.

  4. Graphics of polar figure

    International Nuclear Information System (INIS)

    Macias B, L.R.

    1991-11-01

    The objective of this work, is that starting from a data file coming from a spectra that has been softened, and of the one that have been generated its coordinates to project it in stereographic form, to create the corresponding polar figure making use of the Cyber computer of the ININ by means of the GRAPHOS package. This work only requires a Beta, Fi and Intensity (I) enter data file. It starts of the existence of a softened spectra of which have been generated already with these data, making use of some language that in this case was FORTRAN for the Cyber computer, a program is generated supported in the Graphos package that allows starting of a reading of the Beta, Fi, I file, to generate the points in a stereographic projection and that it culminates with the graph of the corresponding polar figure. The program will request the pertinent information that is wanted to capture in the polar figure just as: date, name of the enter file, indexes of the polar figure, number of levels, radio of the stereographic projection (cms.), crystalline system to which belongs the sample, name the neuter graph file by create and to add the own general data. (Author)

  5. Polarized light and optical measurement

    CERN Document Server

    Clarke, D N; Ter Haar, D

    2013-01-01

    Polarized Light and Optical Measurement is a five-chapter book that begins with a self-consistent conceptual picture of the phenomenon of polarization. Chapter 2 describes a number of interactions of light and matter used in devising optical elements in polarization studies. Specific optical elements are given in Chapter 3. The last two chapters explore the measurement of the state of polarization and the various roles played in optical instrumentation by polarization and polarization-sensitive elements. This book will provide useful information in this field of interest for research workers,

  6. Ionizing device comprising a microchannel electron multiplier with secondary electron emission

    International Nuclear Information System (INIS)

    Chalmeton, Vincent.

    1974-01-01

    The present invention relates to a ionizing device comprising a microchannel electron multiplier involving secondary electron emission as a means of ionization. A system of electrodes is used to accelerate said electrons, ionize the gas and extract the ions from thus created plasma. Said ionizer is suitable for bombarding the target in neutron sources (target of the type of nickel molybdenum coated with tritiated titanium or with a tritium deuterium mixture) [fr

  7. Article comprising a garment or other textile structure for use in controlling body temperature

    Science.gov (United States)

    Butzer, Melissa J.

    2000-01-01

    There is disclosed an article for use in cooling body temperature which comprises a garment having a coat and pant, with each having a body section adapted to receive a portion of the torso of the wearer and extensions from the body section to receive the wearer's limbs. The garment includes a system for circulating temperature controlling fluid from a suitable source through patches removably received in pockets in each of body section and extensions.

  8. Unraveling lipid metabolism in lipid-dependent pathogenic Malassezia yeasts

    NARCIS (Netherlands)

    Celis Ramirez, A.M.

    2017-01-01

    Malassezia yeasts are lipid-dependent fungal species that are common members of the human and animal skin microbiota. The lipid-dependency is a crucial trait in the adaptation process to grow on the skin but also plays a role in their pathogenic life style. Malassezia species can cause several skin

  9. Update of the LIPID MAPS comprehensive classification system for lipids

    NARCIS (Netherlands)

    Fahy, E.; Subramaniam, S.; Murphy, R.C.; Nishijima, M.; Raetz, C.R.H.; Shimizu, T.; Spener, F.; van Meer, G.|info:eu-repo/dai/nl/068570368; Wakelam, M.J.O.; Dennis, E.A.

    2009-01-01

    In 2005, the International Lipid Classification and Nomenclature Committee under the sponsorship of the LIPID MAPS Consortium developed and established a “Comprehensive Classification System for Lipids” based on well-defined chemical and biochemical principles and using an ontology that is

  10. Drug loading to lipid-based cationic nanoparticles

    International Nuclear Information System (INIS)

    Cavalcanti, Leide P.; Konovalov, Oleg; Torriani, Iris L.; Haas, Heinrich

    2005-01-01

    Lipid-based cationic nanoparticles are a new promising option for tumor therapy, because they display enhanced binding and uptake at the neo-angiogenic endothelial cells, which a tumor needs for its nutrition and growth. By loading suitable cytotoxic compounds to the cationic carrier, the tumor endothelial and consequently also the tumor itself can be destroyed. For the development of such novel anti-tumor agents, the control of drug loading and drug release from the carrier matrix is essential. We have studied the incorporation of the hydrophobic anti-cancer agent Paclitaxel (PXL) into a variety of lipid matrices by X-Ray reflectivity measurements. Liposome suspensions from cationic and zwitterionic lipids, comprising different molar fractions of Paclitaxel, were deposited on planar glass substrates. After drying at controlled humidity, well ordered, oriented multilayer stacks were obtained, as proven by the presence of bilayer Bragg peaks to several orders in the reflectivity curves. The presence of the drug induced a decrease of the lipid bilayer spacing, and with an excess of drug, also Bragg peaks of drug crystals could be observed. From the results, insight into the solubility of Paclitaxel in the model membranes was obtained and a structural model of the organization of the drug in the membrane was derived. Results from subsequent pressure/area-isotherm and grazing incidence diffraction (GID) measurements performed with drug/lipid Langmuir monolayers were in accordance with these conjectures

  11. A reconfigurable on-line learning spiking neuromorphic processor comprising 256 neurons and 128K synapses.

    Science.gov (United States)

    Qiao, Ning; Mostafa, Hesham; Corradi, Federico; Osswald, Marc; Stefanini, Fabio; Sumislawska, Dora; Indiveri, Giacomo

    2015-01-01

    Implementing compact, low-power artificial neural processing systems with real-time on-line learning abilities is still an open challenge. In this paper we present a full-custom mixed-signal VLSI device with neuromorphic learning circuits that emulate the biophysics of real spiking neurons and dynamic synapses for exploring the properties of computational neuroscience models and for building brain-inspired computing systems. The proposed architecture allows the on-chip configuration of a wide range of network connectivities, including recurrent and deep networks, with short-term and long-term plasticity. The device comprises 128 K analog synapse and 256 neuron circuits with biologically plausible dynamics and bi-stable spike-based plasticity mechanisms that endow it with on-line learning abilities. In addition to the analog circuits, the device comprises also asynchronous digital logic circuits for setting different synapse and neuron properties as well as different network configurations. This prototype device, fabricated using a 180 nm 1P6M CMOS process, occupies an area of 51.4 mm(2), and consumes approximately 4 mW for typical experiments, for example involving attractor networks. Here we describe the details of the overall architecture and of the individual circuits and present experimental results that showcase its potential. By supporting a wide range of cortical-like computational modules comprising plasticity mechanisms, this device will enable the realization of intelligent autonomous systems with on-line learning capabilities.

  12. Neurosensory and vascular function after 14 months of military training comprising cold winter conditions.

    Science.gov (United States)

    Carlsson, Daniel; Pettersson, Hans; Burström, Lage; Nilsson, Tohr; Wahlström, Jens

    2016-01-01

    This study aimed to examine the effects of 14 months of military training comprising cold winter conditions on neurosensory and vascular function in the hands and feet. Military conscripts (N=54) were assessed with quantitative sensory testing comprising touch, temperature, and vibration perception thresholds and finger systolic blood pressure (FSBP) after local cooling and a questionnaire on neurosensory and vascular symptoms at both baseline and follow-up. Ambient air temperature was recorded with body worn temperature loggers. The subjects showed reduced sensitivity to perception of touch, warmth, cold and vibrations in both the hands and feet except from vibrotactile perception in digit two of the right hand (right dig 2). Cold sensations, white fingers, and pain/discomfort when exposed to cold as well as pain increased in both prevalence and severity. There were no statistically significant changes in FSBP after local cooling. Fourteen months of winter military training comprising cold winter conditions reduced sensation from touch, warmth, cold, and vibrotactile stimulus in both hands and feet and increased the severity and prevalence of symptoms and pain. The vascular function in the hands, measured by FSBP after local cooling, was not affected.

  13. Effects of vanadium pentoxide on the incorporation of (2-/sup 14/C)-acetate into fungal lipids. [/sup 14/C tracer

    Energy Technology Data Exchange (ETDEWEB)

    Anekwe, G.E.

    1976-12-15

    Mycelia of Glomerella cingulata grown in the presence of vanadium pentoxide (V/sub 2/O/sub 5/), incorporated many times less (2-/sup 14/C)-acetate into their lipids than mycelia of the same organism grown in the absence of V/sub 2/O/sub 5/. All neutral and polar lipid fractions investigated were affected. These data suggested that V/sub 2/O/sub 5/ depressed lipid biosynthesis in G. cingulata.

  14. Biosynthesis of membrane lipids of thermophilic archaebacteria and its implication to early evolution of life

    International Nuclear Information System (INIS)

    Oshima, Tairo

    1995-01-01

    The unit lipid of cell membranes of archaebacteria is unique ether lipids, O-dialkylated glycerol with a polar head group at sn-1 position. The chirality of glycerol moiety of the lipids is opposite to that of other kingdoms. The hydrophobic potion consists of saturated C 20 isoprenoid hydrocarbon backbone and is connected to glycerol by an ether linkage. In addition, cell membrane of some of thermophilic archaebacteria are monolayer (in stead of bilayer) of tetraether lipids in which both tails of hydrocarbon chains of two diether lipids are covalently connected in a tail-to-tail fashion. Although the host cell from which contemporary eukaryotes have been derived by endosymbiosis, is speculated to be an archaebacterium, the unique ether lipids raised a serious question to the idea of archabacterial origin of eukaryote cells; why the unique ether lipids are not used to construct cytoplasmic membranes of eukaryotes? The author and his colleagues have studied biosynthesis of membrane liquids of two thermo-acidophilic archaebacteria, Thermoplasma and Sulfolobus. It was found that origins of stereospecificity of glycerol moiety of archaebacterial ether lipids differs form species to species. In Sulfolobus sn-glycerol-1-phosphate (the abnormal isomer of glycerol phosphate) seems to be directly synthesized from glycerol, whereas in Halobacterium stereospecificity of glycerol phosphate is inverted during the lipid synthesis. Recently we found that specific inhibitors for eukaryotes squalene epoxidase inhibit the condensation of diether lipids to tetraether lipids in cell-free extracts of these thermophilic archaebacteria. The results suggest evolutionary implication of archaebacterial tetraether condensing enzyme to eukaryote sterol biosynthesis. Relationships between chemical structures of membrane lipids and early evolution of life will be discussed. (author). Abstract only

  15. Cell-based lipid flippase assay employing fluorescent lipid derivatives

    DEFF Research Database (Denmark)

    Jensen, Maria Stumph; Costa, Sara; Günther-Pomorski, Thomas

    2016-01-01

    P-type ATPases in the P4 subfamily (P4-ATPases) are transmembrane proteins unique for eukaryotes that act as lipid flippases, i.e., to translocate phospholipids from the exofacial to the cytofacial monolayer of cellular membranes. While initially characterized as aminophospholipid translocases, s...... flippase activities in the plasma membrane of cells, using yeast as an example.......P-type ATPases in the P4 subfamily (P4-ATPases) are transmembrane proteins unique for eukaryotes that act as lipid flippases, i.e., to translocate phospholipids from the exofacial to the cytofacial monolayer of cellular membranes. While initially characterized as aminophospholipid translocases......, studies of individual P4-ATPase family members from fungi, plants, and animals show that P4-ATPases differ in their substrate specificities and mediate transport of a broader range of lipid substrates. Here, we describe an assay based on fluorescent lipid derivatives to monitor and characterize lipid...

  16. Polarization-induced hole doping in N-polar III-nitride LED grown by metalorganic chemical vapor deposition

    KAUST Repository

    Yan, Long

    2018-05-03

    Polarization-induced doping has been shown to be effective for wide-bandgap III-nitrides. In this work, we demonstrated a significantly enhanced hole concentration via linearly grading an N-polar AlxGa1-xN (x = 0–0.3) layer grown by metal-organic chemical vapor deposition. The hole concentration increased by ∼17 times compared to that of N-polar p-GaN at 300 K. The fitting results of temperature-dependent hole concentration indicated that the holes in the graded p-AlGaN layer comprised both polarization-induced and thermally activated ones. By optimizing the growth conditions, the hole concentration was further increased to 9.0 × 1017 cm−3 in the graded AlGaN layer. The N-polar blue-violet light-emitting device with the graded p-AlGaN shows stronger electroluminescence than the one with the conventional p-GaN. The study indicates the potential of the polarization doping technique in high-performance N-polar light-emitting devices.

  17. Polarization-induced hole doping in N-polar III-nitride LED grown by metalorganic chemical vapor deposition

    KAUST Repository

    Yan, Long; Zhang, Yuantao; Han, Xu; Deng, Gaoqiang; Li, Pengchong; Yu, Ye; Chen, Liang; Li, Xiaohang; Song, Junfeng

    2018-01-01

    Polarization-induced doping has been shown to be effective for wide-bandgap III-nitrides. In this work, we demonstrated a significantly enhanced hole concentration via linearly grading an N-polar AlxGa1-xN (x = 0–0.3) layer grown by metal-organic chemical vapor deposition. The hole concentration increased by ∼17 times compared to that of N-polar p-GaN at 300 K. The fitting results of temperature-dependent hole concentration indicated that the holes in the graded p-AlGaN layer comprised both polarization-induced and thermally activated ones. By optimizing the growth conditions, the hole concentration was further increased to 9.0 × 1017 cm−3 in the graded AlGaN layer. The N-polar blue-violet light-emitting device with the graded p-AlGaN shows stronger electroluminescence than the one with the conventional p-GaN. The study indicates the potential of the polarization doping technique in high-performance N-polar light-emitting devices.

  18. Polarized nuclear target based on parahydrogen induced polarization

    OpenAIRE

    Budker, D.; Ledbetter, M. P.; Appelt, S.; Bouchard, L. S.; Wojtsekhowski, B.

    2012-01-01

    We discuss a novel concept of a polarized nuclear target for accelerator fixed-target scattering experiments, which is based on parahydrogen induced polarization (PHIP). One may be able to reach a 33% free-proton polarization in the ethane molecule. The potential advantages of such a target include operation at zero magnetic field, fast ($\\sim$100 Hz) polarization reversal, and operation with large intensity of an electron beam.

  19. Solid lipid nanoparticles for parenteral drug delivery

    NARCIS (Netherlands)

    Wissing, S.A.; Kayser, Oliver; Muller, R.H.

    2004-01-01

    This review describes the use of nanoparticles based on solid lipids for the parenteral application of drugs. Firstly, different types of nanoparticles based on solid lipids such as "solid lipid nanoparticles" (SLN), "nanostructured lipid carriers" (NLC) and "lipid drug conjugate" (LDC)

  20. Regional differences in the lateral mobility of plasma membrane lipids in a molluscan embryo

    NARCIS (Netherlands)

    Speksnijder, J.E.; Dohmen, M.R.; Tertoolen, L.G.J.; Laat, S.W. de

    1985-01-01

    Regional and temporal differences in plasma membrane lipid mobility have been analyzed during the first three cleavage cycles of the embryo of the polar-lobe-forming mollusc Nassarius reticulatus by the fluorescence photobleaching recovery (FPR) method, using 1,1′-ditetradecyl

  1. Atomistic simulations of anionic Au-144(SR)(60) nanoparticles interacting with asymmetric model lipid membranes

    DEFF Research Database (Denmark)

    Heikkila, E.; Martinez-Seara, H.; Gurtovenko, A. A.

    2014-01-01

    whose lipid composition and transmembrane distribution are to a large extent consistent with real plasma membranes of eukaryotic cells. To this end, we use a model system which comprises two cellular compartments, extracellular and cytosolic, divided by two asymmetric lipid bilayers. The simulations...... clearly show that AuNP- attaches to the extracellular membrane surface within a few tens of nanoseconds, while it avoids contact with the membrane on the cytosolic side. This behavior stems from several factors. In essence, when the nanoparticle interacts with lipids in the extracellular compartment...

  2. Development, in vitro and in vivo evaluations of novel lipid drug delivery system of (P. Beauv.

    Directory of Open Access Journals (Sweden)

    Chukwuebuka Umeyor

    2016-11-01

    Full Text Available Newbouldia laevis (P. Beauv. is a tropical rainforest plant used in traditional folk medicine for the treatment of malaria, cough, joint pains, stomach ache, oedema and inflammation. The main thrust of this research work was to study the analgesic/anti-nociceptive properties of N. laevis -loaded solid lipid microdispersions. N. laevis leaves were extracted using ethanol, and the extract was formulated into solid lipid microdispersions using lipid matrix comprising a rational blend of Precirol ® ATO 5 and Softisan ® 154. Characterization of the solid lipid microdispersions include determination of morphology, particle size, pH, thermal property, encapsulation efficiency percentage and analgesic/anti-nociceptive property. The results obtained showed that the particles were spherical with sizes ranging from 40 µm to 125 µm. The solid lipid microdispersions maintained a stable pH within the acidic region of 5–6 with insignificant variations ( p > 0.05 over a period of 90 days. Thermal analysis showed that N. laevis was entrapped in the lipid matrix used for the formulations. Solid lipid microdispersions recorded a maximum encapsulation efficiency up to 88.1%. N. laevis -loaded solid lipid microdispersions also produced good analgesic/anti-nociceptive property comparable with the standard diclofenac potassium. N. laevis -loaded solid lipid microdispersions showed good analgesic/anti-nociceptive effect and could be used in the treatment and management of pain.

  3. Role of lipids in the formation and maintenance of the cutaneous permeability barrier.

    Science.gov (United States)

    Feingold, Kenneth R; Elias, Peter M

    2014-03-01

    The major function of the skin is to form a barrier between the internal milieu and the hostile external environment. A permeability barrier that prevents the loss of water and electrolytes is essential for life on land. The permeability barrier is mediated primarily by lipid enriched lamellar membranes that are localized to the extracellular spaces of the stratum corneum. These lipid enriched membranes have a unique structure and contain approximately 50% ceramides, 25% cholesterol, and 15% free fatty acids with very little phospholipid. Lamellar bodies, which are formed during the differentiation of keratinocytes, play a key role in delivering the lipids from the stratum granulosum cells into the extracellular spaces of the stratum corneum. Lamellar bodies contain predominantly glucosylceramides, phospholipids, and cholesterol and following the exocytosis of lamellar lipids into the extracellular space of the stratum corneum these precursor lipids are converted by beta glucocerebrosidase and phospholipases into the ceramides and fatty acids, which comprise the lamellar membranes. The lipids required for lamellar body formation are derived from de novo synthesis by keratinocytes and from extra-cutaneous sources. The lipid synthetic pathways and the regulation of these pathways are described in this review. In addition, the pathways for the uptake of extra-cutaneous lipids into keratinocytes are discussed. This article is part of a Special Issue entitled The Important Role of Lipids in the Epidermis and their Role in the Formation and Maintenance of the Cutaneous Barrier. Guest Editors: Kenneth R. Feingold and Peter Elias. Published by Elsevier B.V.

  4. Ultrastructural study on dynamics of lipid bodies and plastids during ripening of chili pepper fruits.

    Science.gov (United States)

    Liu, Lin

    2013-03-01

    Dynamics of lipid bodies and plastids in chili pepper fruits during ripening were investigated by means of transmission electron microscopy. Mesocarp of chili pepper fruits consists of collenchyma, normal parenchyma, and huge celled parenchyma. In mature green fruits, plastids contain numerous thylakoids that are well organized into grana in collenchyma, a strikingly huge amount of starch and irregularly organized thylakoids in normal parenchyma, and simple tubes rather than thylakoids in huge celled parenchyma. These morphological features suggest that plastids are chloroplasts in collenchyma, chloroamyloplasts in normal parenchyma, proplastids in huge celled parenchyma. As fruits ripen to red, plastids in all cell types convert to chromoplasts and, concomitantly, lipid bodies accumulate in both cytoplasm and chromoplasts. Cytosolic lipid bodies are lined up in a regular layer adjacent to plasma membrane. The cytosolic lipid body consists of a core surrounded by a membrane. The core is comprised of a more electron-dense central part enclosed by a slightly less electron-dense peripheral layer. Plastidial lipid bodies in collenchyma, normal parenchyma, and endodermis initiate as plastoglobuli, which in turn convert to rod-like structures. Therefore, plastidial lipid bodies are more dynamic than cytosolic lipid bodies. Both cytosolic and plastidial lipid bodies contain rich unsaturated lipids. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Analysis of lipid profile in lipid storage myopathy.

    Science.gov (United States)

    Aguennouz, M'hammed; Beccaria, Marco; Purcaro, Giorgia; Oteri, Marianna; Micalizzi, Giuseppe; Musumesci, Olimpia; Ciranni, Annmaria; Di Giorgio, Rosa Maria; Toscano, Antonio; Dugo, Paola; Mondello, Luigi

    2016-09-01

    Lipid dysmetabolism disease is a condition in which lipids are stored abnormally in organs and tissues throughout the body, causing muscle weakness (myopathy). Usually, the diagnosis of this disease and its characterization goes through dosage of Acyl CoA in plasma accompanied with evidence of droplets of intra-fibrils lipids in the patient muscle biopsy. However, to understand the pathophysiological mechanisms of lipid storage diseases, it is useful to identify the nature of lipids deposited in muscle fiber. In this work fatty acids and triglycerides profile of lipid accumulated in the muscle of people suffering from myopathies syndromes was characterized. In particular, the analyses were carried out on the muscle biopsy of people afflicted by lipid storage myopathy, such as multiple acyl-coenzyme A dehydrogenase deficiency, and neutral lipid storage disease with myopathy, and by the intramitochondrial lipid storage dysfunctions, such as deficiencies of carnitine palmitoyltransferase II enzyme. A single step extraction and derivatization procedure was applied to analyze fatty acids from muscle tissues by gas chromatography with a flame ionization detector and with an electronic impact mass spectrometer. Triglycerides, extracted by using n-hexane, were analyzed by high performance liquid chromatography coupled to mass spectrometer equipped with an atmospheric pressure chemical ionization interface. The most representative fatty acids in all samples were: C16:0 in the 13-24% range, C18:1n9 in the 20-52% range, and C18:2n6 in the 10-25% range. These fatty acids were part of the most representative triglycerides in all samples. The data obtained was statistically elaborated performing a principal component analysis. A satisfactory discrimination was obtained among the different diseases. Using component 1 vs component 3 a 43.3% of total variance was explained. Such results suggest the important role that lipid profile characterization can have in supporting a correct

  6. Lipidomic analysis of epidermal lipids: a tool to predict progression of inflammatory skin disease in humans.

    Science.gov (United States)

    Li, Shan; Ganguli-Indra, Gitali; Indra, Arup K

    2016-05-01

    Lipidomics is the large-scale profiling and characterization of lipid species in a biological system using mass spectrometry. The skin barrier is mainly comprised of corneocytes and a lipid-enriched extracellular matrix. The major skin lipids are ceramides, cholesterol and free fatty acids (FFA). Lipid compositions are altered in inflammatory skin disorders with disrupted skin barrier such as atopic dermatitis (AD). Here we discuss some of the recent applications of lipidomics in human skin biology and in inflammatory skin diseases such as AD, psoriasis and Netherton syndrome. We also review applications of lipidomics in human skin equivalent and in pre-clinical animal models of skin diseases to gain insight into the pathogenesis of the skin disease. Expert commentary: Skin lipidomics analysis could be a fast, reliable and noninvasive tool to characterize the skin lipid profile and to monitor the progression of inflammatory skin diseases such as AD.

  7. Interfacial Tension and Surface Pressure of High Density Lipoprotein, Low Density Lipoprotein, and Related Lipid Droplets

    DEFF Research Database (Denmark)

    Ollila, O. H. S.; Lamberg, A.; Lehtivaara, M.

    2012-01-01

    ) are essentially lipid droplets surrounded by specific proteins, their main function being to transport cholesterol. Interfacial tension and surface pressure of these particles are of great interest because they are related to the shape and the stability of the droplets and to protein adsorption at the interface....... Here we use coarse-grained molecular-dynamics simulations to consider a number of related issues by calculating the interfacial tension in protein-free lipid droplets, and in HDL and LDL particles mimicking physiological conditions. First, our results suggest that the curvature dependence......Lipid droplets play a central role in energy storage and metabolism on a cellular scale. Their core is comprised of hydrophobic lipids covered by a surface region consisting of amphiphilic lipids and proteins. For example, high and low density lipoproteins (HDL and LDL, respectively...

  8. Can lipid nanoparticles improve intestinal absorption?

    Science.gov (United States)

    Mendes, M; Soares, H T; Arnaut, L G; Sousa, J J; Pais, A A C C; Vitorino, C

    2016-12-30

    Lipid nanoparticles and their multiple designs have been considered appealing nanocarrier systems. Bringing the benefits of these nanosystems together with conventional coating technology clearly results in product differentiation. This work aimed at developing an innovative solid dosage form for oral administration based on tableting nanostructured lipid carriers (NLC), coated with conventional polymer agents. NLC dispersions co-encapsulating olanzapine and simvastatin (Combo-NLC) were produced by high pressure homogenization, and evaluated in terms of scalability, drying procedure, tableting and performance from in vitro release, cytotoxicity and intestinal permeability stand points. Factorial design indicated that the scaling-up of the NLC production is clearly feasible. Spray-drying was the method selected to obtain dry particles, not only because it consists of a single step procedure, but also because it facilitates the coating process of NLC with different polymers. Modified NLC formulations with the polymers allowed obtaining distinct release mechanisms, comprising immediate, delayed and prolonged release. Sureteric:Combo-NLC provided a low cytotoxicity profile, along with a ca. 12-fold OL/3-fold SV higher intestinal permeability, compared to those obtained with commercial tablets. Such findings can be ascribed to drug protection and control over release promoted by NLC, supporting them as a versatile platform able to be modified according to the intended needs. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Experiments with Fermilab polarized proton and polarized antiproton beams

    International Nuclear Information System (INIS)

    Yokosawa, A.

    1990-01-01

    We summarize activities concerning the Fermilab polarized beams. They include a brief description of the polarized-beam facility, measurements of beam polarization by polarimeters, asymmetry measurements in the π degree production at high p perpendicular and in the Λ (Σ degree), π ± , π degree production at large x F , and Δσ L (pp, bar pp) measurements. 18 refs

  10. NUCLEON POLARIZATION IN 3-BODY MODELS OF POLARIZED LI-6

    NARCIS (Netherlands)

    SCHELLINGERHOUT, NW; KOK, LP; COON, SA; ADAM, RM

    1993-01-01

    Just as He-3 --> can be approximately characterized as a polarized neutron target, polarized Li-6D has been advocated as a good isoscalar nuclear target for the extraction of the polarized gluon content of the nucleon. The original argument rests upon a presumed ''alpha + deuteron'' picture of Li-6,

  11. Dermal extracellular lipid in birds.

    Science.gov (United States)

    Stromberg, M W; Hinsman, E J; Hullinger, R L

    1990-01-01

    A light and electron microscopic study of the skin of domestic chickens, seagulls, and antarctic penguins revealed abundant extracellular dermal lipid and intracellular epidermal lipid. Dermal lipid appeared ultrastructurally as extracellular droplets varying from less than 1 micron to more than 25 microns in diameter. The droplets were often irregularly contoured, sometimes round, and of relatively low electron density. Processes of fibrocytes were often seen in contact with extracellular lipid droplets. Sometimes a portion of such a droplet was missing, and this missing part appeared to have been "digested away" by the cell process. In places where cells or cell processes are in contact with fact droplets, there are sometimes extracellular membranous whorls or fragments which have been associated with the presence of fatty acids. Occasionally (in the comb) free fat particles were seen in intimate contact with extravasated erythrocytes. Fat droplets were seen in the lumen of small dermal blood and lymph vessels. We suggest that the dermal extracellular lipid originates in the adipocyte layer and following hydrolysis the free fatty acids diffuse into the epidermis. Here they become the raw material for forming the abundant neutral lipid contained in many of the epidermal cells of both birds and dolphins. The heretofore unreported presence and apparently normal utilization of abundant extracellular lipid in birds, as well as the presence of relatively large droplets of neutral lipid in dermal vessels, pose questions which require a thorough reappraisal of present concepts of the ways in which fat is distributed and utilized in the body.

  12. The Flexibility of Ectopic Lipids

    Directory of Open Access Journals (Sweden)

    Hannah Loher

    2016-09-01

    Full Text Available In addition to the subcutaneous and the visceral fat tissue, lipids can also be stored in non-adipose tissue such as in hepatocytes (intrahepatocellular lipids; IHCL, skeletal (intramyocellular lipids; IMCL or cardiac muscle cells (intracardiomyocellular lipids; ICCL. Ectopic lipids are flexible fuel stores that can be depleted by physical exercise and repleted by diet. They are related to obesity and insulin resistance. Quantification of IMCL was initially performed invasively, using muscle biopsies with biochemical and/or histological analysis. 1H-magnetic resonance spectroscopy (1H-MRS is now a validated method that allows for not only quantifying IMCL non-invasively and repeatedly, but also assessing IHCL and ICCL. This review summarizes the current available knowledge on the flexibility of ectopic lipids. The available evidence suggests a complex interplay between quantitative and qualitative diet, fat availability (fat mass, insulin action, and physical exercise, all important factors that influence the flexibility of ectopic lipids. Furthermore, the time frame of the intervention on these parameters (short-term vs. long-term appears to be critical. Consequently, standardization of physical activity and diet are critical when assessing ectopic lipids in predefined clinical situations.

  13. Neuroimaging of Lipid Storage Disorders

    Science.gov (United States)

    Rieger, Deborah; Auerbach, Sarah; Robinson, Paul; Gropman, Andrea

    2013-01-01

    Lipid storage diseases, also known as the lipidoses, are a group of inherited metabolic disorders in which there is lipid accumulation in various cell types, including the central nervous system, because of the deficiency of a variety of enzymes. Over time, excessive storage can cause permanent cellular and tissue damage. The brain is particularly…

  14. Fasting and nonfasting lipid levels

    DEFF Research Database (Denmark)

    Langsted, Anne; Freiberg, Jacob J; Nordestgaard, Børge G

    2008-01-01

    Lipid profiles are usually measured after fasting. We tested the hypotheses that these levels change only minimally in response to normal food intake and that nonfasting levels predict cardiovascular events.......Lipid profiles are usually measured after fasting. We tested the hypotheses that these levels change only minimally in response to normal food intake and that nonfasting levels predict cardiovascular events....

  15. Lipid and bile acid analysis

    NARCIS (Netherlands)

    Argmann, Carmen A.; Houten, Sander M.; Champy, Marie-France; Auwerx, Johan

    2006-01-01

    Lipids are important body constituents that are vital for cellular, tissue, and whole-body homeostasis. Lipids serve as crucial membrane components, constitute the body's main energy reservoir, and are important signaling molecules. As a consequence of these pleiotropic functions, many common

  16. Source of spin polarized electrons

    International Nuclear Information System (INIS)

    Pierce, D.T.; Meier, F.A.; Siegmann, H.C.

    1976-01-01

    A method is described of producing intense beams of polarized free electrons in which a semiconductor with a spin orbit split valence band and negative electron affinity is used as a photocathode and irradiated with circularly polarized light

  17. Linearly polarized photons at ELSA

    Energy Technology Data Exchange (ETDEWEB)

    Eberhardt, Holger [Physikalisches Institut, Universitaet Bonn (Germany)

    2009-07-01

    To investigate the nucleon resonance regime in meson photoproduction, double polarization experiments are currently performed at the electron accelerator ELSA in Bonn. The experiments make use of a polarized target and circularly or linearly polarized photon beams. Linearly polarized photons are produced by coherent bremsstrahlung from an accurately aligned diamond crystal. The orientation of the crystal with respect to the electron beam is measured using the Stonehenge-Technique. Both, the energy of maximum polarization and the plane of polarization, can be deliberately chosen for the experiment. The linearly polarized beam provides the basis for the measurement of azimuthal beam asymmetries, such as {sigma} (unpolarized target) and G (polarized target). These observables are extracted in various single and multiple meson photoproduction channels.

  18. Axon initial segment cytoskeleton comprises a multiprotein submembranous coat containing sparse actin filaments

    Science.gov (United States)

    Jones, Steven L.; Korobova, Farida

    2014-01-01

    The axon initial segment (AIS) of differentiated neurons regulates action potential initiation and axon–dendritic polarity. The latter function depends on actin dynamics, but actin structure and functions at the AIS remain unclear. Using platinum replica electron microscopy (PREM), we have characterized the architecture of the AIS cytoskeleton in mature and developing hippocampal neurons. The AIS cytoskeleton assembly begins with bundling of microtubules and culminates in formation of a dense, fibrillar–globular coat over microtubule bundles. Immunogold PREM revealed that the coat contains a network of known AIS proteins, including ankyrin G, spectrin βIV, neurofascin, neuronal cell adhesion molecule, voltage-gated sodium channels, and actin filaments. Contrary to existing models, we find neither polarized actin arrays, nor dense actin meshworks in the AIS. Instead, the AIS contains two populations of sparse actin filaments: short, stable filaments and slightly longer dynamic filaments. We propose that stable actin filaments play a structural role for formation of the AIS diffusion barrier, whereas dynamic actin may promote AIS coat remodeling. PMID:24711503

  19. An adhesome comprising laminin, dystroglycan and myosin IIA is required during notochord development in Xenopus laevis.

    Science.gov (United States)

    Buisson, Nicolas; Sirour, Cathy; Moreau, Nicole; Denker, Elsa; Le Bouffant, Ronan; Goullancourt, Aline; Darribère, Thierry; Bello, Valérie

    2014-12-01

    Dystroglycan (Dg) is a transmembrane receptor for laminin that must be expressed at the right time and place in order to be involved in notochord morphogenesis. The function of Dg was examined in Xenopus laevis embryos by knockdown of Dg and overexpression and replacement of the endogenous Dg with a mutated form of the protein. This analysis revealed that Dg is required for correct laminin assembly, for cell polarization during mediolateral intercalation and for proper differentiation of vacuoles. Using mutations in the cytoplasmic domain, we identified two sites that are involved in cell polarization and are required for mediolateral cell intercalation, and a site that is required for vacuolation. Furthermore, using a proteomic analysis, the cytoskeletal non-muscle myosin IIA has been identified for the first time as a molecular link between the Dg-cytoplasmic domain and cortical actin. The data allowed us to identify the adhesome laminin-Dg-myosin IIA as being required to maintain the cortical actin cytoskeleton network during vacuolation, which is crucial to maintain the shape of notochordal cells. © 2014. Published by The Company of Biologists Ltd.

  20. North Polar Cap

    Science.gov (United States)

    2004-01-01

    [figure removed for brevity, see original site] This week we will be looking at five examples of laminar wind flow on the north polar cap. On Earth, gravity-driven south polar cap winds are termed 'catabatic' winds. Catabatic winds begin over the smooth expanse of the cap interior due to temperature differences between the atmosphere and the surface. Once begun, the winds sweep outward along the surface of the polar cap toward the sea. As the polar surface slopes down toward sealevel, the wind speeds increase. Catabatic wind speeds in the Antartic can reach several hundreds of miles per hour. In the images of the Martian north polar cap we can see these same type of winds. Notice the streamers of dust moving downslope over the darker trough sides, these streamers show the laminar flow regime coming off the cap. Within the trough we see turbulent clouds of dust, kicked up at the trough base as the winds slow down and enter a chaotic flow regime. The horizontal lines in these images are due to framelet overlap and lighting conditions over the bright polar cap. Image information: VIS instrument. Latitude 86.5, Longitude 64.5 East (295.5 West). 40 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen

  1. Lysosomal degradation of membrane lipids.

    Science.gov (United States)

    Kolter, Thomas; Sandhoff, Konrad

    2010-05-03

    The constitutive degradation of membrane components takes place in the acidic compartments of a cell, the endosomes and lysosomes. Sites of lipid degradation are intralysosomal membranes that are formed in endosomes, where the lipid composition is adjusted for degradation. Cholesterol is sorted out of the inner membranes, their content in bis(monoacylglycero)phosphate increases, and, most likely, sphingomyelin is degraded to ceramide. Together with endosomal and lysosomal lipid-binding proteins, the Niemann-Pick disease, type C2-protein, the GM2-activator, and the saposins sap-A, -B, -C, and -D, a suitable membrane lipid composition is required for degradation of complex lipids by hydrolytic enzymes. Copyright 2009 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  2. Stanford polarized atomic beam target

    International Nuclear Information System (INIS)

    Mavis, D.G.; Dunham, J.S.; Hugg, J.W.; Glavish, H.F.

    1976-01-01

    A polarized atomic beam source was used to produce an atomic hydrogen beam which was in turn used as a polarized proton target. A target density of 2 x 10'' atoms/cm 3 and a target polarization of 0.37 without the use of rf transitions were measured. These measurements indicate that a number of experiments are currently feasible with a variety of polarized target beams

  3. Lipid profiling in sewage sludge.

    Science.gov (United States)

    Zhu, Fenfen; Wu, Xuemin; Zhao, Luyao; Liu, Xiaohui; Qi, Juanjuan; Wang, Xueying; Wang, Jiawei

    2017-06-01

    High value-added reutilization of sewage sludge from wastewater treatment plants (WWTPs) is essential in sustainable development in WWTPs. However, despite the advantage of high value reutilization, this process must be based on a detailed study of organics in sludge. We used the methods employed in life sciences to determine the profile of lipids (cellular lipids, free fatty acids (FFAs), and wax/gum) in five sludge samples obtained from three typical WWTPs in Beijing; these samples include one sludge sample from a primary sedimentation tank, two activated sludge samples from two Anaerobic-Anoxic-Oxic (A2/O) tanks, and two activated sludge samples from two membrane bioreactor tanks. The percentage of total raw lipids varied from 2.90% to 12.3%. Sludge from the primary sedimentation tank showed the highest concentrations of lipid, FFA, and wax/gum and the second highest concentration of cellular lipids. All activated sludge contained an abundance of cellular lipids (>54%). Cells in sludge can from plants, animals, microbes and so on in wastewater. Approximately 14 species of cellular lipids were identified, including considerable high value-potential ceramide (9567-38774 mg/kg), coenzyme (937-3897 mg/kg), and some phosphatidylcholine (75-548 mg/kg). The presence of those lipid constituents would thus require a wider range of recovery methods for sludge. Both cellular lipids and FFAs contain an abundance of C16-C18 lipids at high saturation level, and they serve as good resources for biodiesel production. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Three-photon polarization ququarts: polarization, entanglement and Schmidt decompositions

    International Nuclear Information System (INIS)

    Fedorov, M V; Miklin, N I

    2015-01-01

    We consider polarization states of three photons, propagating collinearly and having equal given frequencies but with arbitrary distributed horizontal or vertical polarizations of photons. A general form of such states is a superposition of four basic three-photon polarization modes, to be referred to as the three-photon polarization ququarts (TPPQ). All such states can be considered as consisting of one- and two-photon parts, which can be entangled with each other. The degrees of entanglement and polarization, as well as the Schmidt decomposition and Stokes vectors of TPPQ are found and discussed. (paper)

  5. The Role of Tetraether Lipid Composition in the Adaptation of Thermophilic Archaea to Acidity

    Directory of Open Access Journals (Sweden)

    Eric eBoyd

    2013-04-01

    Full Text Available Diether and tetraether lipids are fundamental components of the archaeal cell membrane. Archaea adjust the degree of tetraether lipid cyclization in order to maintain functional membranes and cellular homeostasis when confronted with pH and/or thermal stress. Thus, the ability to adjust tetraether lipid composition likely represents a critical phenotypic trait that enabled archaeal diversification into environments characterized by extremes in pH and/or temperature. Here we assess the relationship between geochemical variation, core- and polar-isoprenoid glycerol dibiphytanyl glycerol tetraether (C-iGDGT and P-iGDGT, respectively lipid composition, and archaeal 16S rRNA gene diversity and abundance in 27 geothermal springs in Yellowstone National Park (YNP, Wyoming. The composition and abundance of C-iGDGT and P-iGDGT lipids recovered from geothermal ecosystems were distinct from surrounding soils, indicating that they are synthesized endogenously. With the exception of GDGT-0 (no cyclopentyl rings, the abundances of individual C-iGDGT and P-iGDGT lipids were significantly correlated. The abundance of a number of individual tetraether lipids varied positively with the relative abundance of individual 16S rRNA gene sequences, most notably crenarchaeol in both the core and polar GDGT fraction and sequences closely affiliated with Candidatus Nitrosocaldus yellowstonii. This finding supports the proposal that crenarchaeol is a biomarker for nitrifying archaea. Variation in the degree of cyclization of C- and P-iGDGT lipids recovered from geothermal mats and sediments could best be explained by variation in spring pH, with lipids from acidic environments tending to have, on average, more internal cyclic rings than those from higher pH ecosystems. Likewise, variation in the phylogenetic composition of archaeal 16S rRNA genes could best be explained by spring pH. In turn, the phylogenetic similarity of archaeal 16S rRNA genes was significantly

  6. Polarization effects in hadron fragmentation

    International Nuclear Information System (INIS)

    Lednicky, R.

    1984-01-01

    Hadron polarization (spin alignment) and polarization asymmetry are discussed in terms of the quark recombination model with the spin-orbit interaction taken into account. It is shown that predictions of this model are at least in qualitative agreement with experimental data. Various polarization mechanisms in terms of this model and the possibility of their checking are also discussed

  7. Composites comprising novel RTIL-based polymers, and methods of making and using same

    Science.gov (United States)

    Gin, Douglas; Carlisle, Trevor; Noble, Richard; Nicodemus, Garret; McDanel, William; Cowan, Matthew

    2017-06-27

    The invention includes compositions comprising curable imidazolium-functionalized poly(room-temperature ionic liquid) copolymers and homopolymers. The invention further includes methods of preparing and using the compositions of the invention. The invention further includes novel methods of preparing thin, supported, room-temperature ionic liquid-containing polymeric films on a porous support. In certain embodiments, the methods of the invention avoid the use of a gutter layer, which greatly reduces the overall gas permeance and selectivity of the composite membrane. In other embodiments, the films of the invention have increased gas selectivity and permeance over films prepared using methods described in the prior art.

  8. Palladium catalyst system comprising zwitterion and/or acid-​functionalized ionic liquid

    DEFF Research Database (Denmark)

    2011-01-01

    The present invention concerns a catalyst system in particular a catalyst system comprising Palladium (Pd), a zwitterion and/or an acid-functionalized ionic liquid, and one or more phosphine ligands, wherein the Pd catalyst can be provided by a complex precursor, such as Pd(CH3COO)2, PdCI2, Pd(CH3...... methyl methacrylate and/or methacrylic acid. Catalyst systems according to the invention are suitable for reactions forming separable product and catalyst phases and supported ionic liquid phase SILP applications....

  9. Possibility of sorption purification of chromium comprising waste waters of galvanic production by inorganic ion exchangers

    International Nuclear Information System (INIS)

    Khaynakov, S.A.; Likov, E.P.; Bortun, A.I.; Belyukov, V.N.

    1986-01-01

    Present work is devoted to possibilities of sorption purification of chromium comprising waste waters of galvanic production by inorganic ion exchangers. Thus, the comparative study of sorption of chromium ions on anion exchanger A B-17 and on inorganic ion exchangers on the basis of hydrated titanium and zirconium dioxides in static and dynamic conditions is conducted. The influence of chromium ions concentration, solutions acidity (ph=1÷12) and presence of base electrolyte on sorption is studied. The state of chromium ions sorbed by inorganic ion exchangers is studied by means of infrared spectroscopy and spectroscopy. It is defined that inorganic sorbents could be used for chromium extraction from different solutions.

  10. HVDC Solution for Offshore Wind Park Comprising Turbines Equipped with Full-Range Converters

    DEFF Research Database (Denmark)

    Sharma, Ranjan; Rasmussen, Tonny Wederberg; Jensen, Kim Høj

    2010-01-01

    a voltage drop is created at the collection grid, the wind turbines go into fault-ride-through mode. The power output from each of the wind turbines is thus reduced to balance the system power. The detailed explanation of the strategy is presented in the paper. Matlab simulation model was prepared and some...... of a HVDC transmission system. The power system under study includes an offshore wind farm comprising turbines equipped with full range converters. The collection network is a local AC grid. Power transmission is done through HVDC system. The grid side VSC (voltage source converter) controls the DC voltage...

  11. IDIOMS THAT COMPRISE THE PRESENCE OF TURKISH WORDS IN GREEK CYPRIOT LANGUAGE

    OpenAIRE

    Şevket ÖZNUR; Mahmut İSLÂMOĞLU

    2010-01-01

    In this communiqué again we preferred to present some examples from the effects of Turkish Cypriot Culture. For a few years, we have concentrated on our culture’s effect on other cultures in Cyprus. Bearing in mind that we have lived together for hundreds of years with other societies, we have seen fit to give examples of the cultural interaction between other cultures and Turkish Cypriot culture. Our communiqué mostly comprises the effects of Turkish Culture. We have found it convenient to p...

  12. Electrical characterization of MIM capacitor comprises an adamantane film at room temperature

    Energy Technology Data Exchange (ETDEWEB)

    Tiwari, Rajanish N., E-mail: rajanisht@gmail.com [Department of Physics and Astronomical Sciences, Central University of Himachal Pradesh, Dharmshala 176206 Kangra, H.P. India (India); Toyota Technological Institute, 2-12-1Hisakata, Tempaku-Ku, Nagoya 468-8511 (Japan); Yoshimura, Masamichi [Department of Physics and Astronomical Sciences, Central University of Himachal Pradesh, Dharmshala 176206 Kangra, H.P. India (India)

    2016-06-15

    We fabricated a new metal-insulator-metal capacitor at room temperature, comprising a ∼90 nm thin low–k adamantane film on a Si substrate. The surface morphology of deposited organic film was investigated by using scanning electron microscopy and Raman spectroscopy, which is confirmed that the adamantane thin film was uniformly distributed on the Si surface. The adamantane film exhibits a low leakage current density of 7.4 x 10{sup −7} A/cm{sup 2} at 13.5 V, better capacitance density of 2.14 fF/μm{sup 2} at 100 KHz.

  13. Anticonvection device for a narrow space comprised between two parallel walls

    International Nuclear Information System (INIS)

    Costes, Didier.

    1975-01-01

    The invention relates to an anticonvection device providing strong limitations against the convection currents inside a space submitted to a vertical thermal gradient and more especially the space enclosed between the inner wall of a vessel generally cyclindrical in shape and of vertical axis, intended for a nuclear reactor, and the outer wall of a plug fitted together with said vessel. To this effect, said device is characterized in that it comprises a packing of a material of open porosity and thickness-wise elasticity, in the form of threads, fibers, knitted-cloths or sheets separated by distances shorter than the thickness of stagnancy under the temperature conditions inside said space [fr

  14. Detection matrix of an electromagnetic radiation and radiological image intensifier comprising such a matrix

    International Nuclear Information System (INIS)

    Fraleux, Jean.

    1982-01-01

    This invention concerns a detection matrix comprising, in an electrode lattice of lines and columns, addressing means constituted of thin film technology MOS transistors and photoconductances which enable the number of unit module crossings to be halved and to bring about an increase in the effective detection area. This detection matrix is employed in radiological image intensifiers where it ensures the conversion of incident X photons into reading electric signals or only the detection of a visible radiation in the case where the incident X photons are converted into lesser energy photons by a scintillator. The scintillator is then formed of a panel brought into contact with the detector mosaic [fr

  15. Detection of polar vapours

    International Nuclear Information System (INIS)

    Blyth, D.A.

    1980-01-01

    Apparatus for monitoring for polar vapours in a gas consists of (i) a body member defining a passage through which a continuous stream of the gas passes; (ii) an ionising source associated with a region of the passage such that ionization of the gas stream takes place substantially only within the region and also any polar vapour molecules present therein will react with the gas formed to generate ion clusters; and (iii) an electrode for collecting ions carried by the gas stream, the electrode being positioned in the passage downstream of the region and separated from the region by a sufficient distance to ensure that no substantial number of the gas ions formed in said region remains in the gas stream at the collector electrode whilst ensuring that a substantial proportion of the ion clusters formed in the region does remain in the gas stream at the collector electrode. (author)

  16. Perspectives for polarized antiprotons

    International Nuclear Information System (INIS)

    Lenisa, Paolo

    2012-01-01

    Polarized antiprotons would open a new window in hadron physics providing access to a wealth of single and double spin observables in proton-antiproton interactions. The PAX Collaboration aims to perform the first ever measurement of the spin-dependence of the proton-antiproton cross section at the AD ring at CERN. The spin-dependence of the cross section could in principle be exploited by the spin-filtering technique for the production of a polarized antiproton beam. As a preparatory phase to the experimentation at AD, the PAX Collaboration has initiated a series of dedicated studies with protons at the COSY-ring in Juelich (Germany), aimed at the commissioning of the experimental apparatus and confirmation of the predictions for spin-filtering with protons.

  17. The Polar Cusp

    International Nuclear Information System (INIS)

    Holtet, J.A.; Egeland, A.

    1985-01-01

    The upper atmosphere at high latitudes is often called the ''earth's window to outer space.'' Through various electrodynamic coupling processes, as well as direct transfer of particles, many of the geophysical effects displayed are direct manifestations of phenomena occurring in deep space. The high latitude ionosphere also exerts a feedback on the regions of the magnetosphere and atmosphere to which it is coupled. Of particular interest are the sections of the near space known as the Polar Cusp. A vast portion of the Earth's magnetic field envelope is electrically connected to these regions. This geometry results in a spatial mapping of the magnetospheric processes and a focusing on the ionosphere. In the Polar Cusps, the solar wind plasma also has direct access to the upper atmosphere

  18. Polarized electrogowdy spacetimes censored

    International Nuclear Information System (INIS)

    Nungesser, Ernesto

    2010-01-01

    A sketch of the proof of strong cosmic censorship is presented for a class of solutions of the Einstein-Maxwell equations, those with polarized Gowdy symmetry. A key element of the argument is the observation that by means of a suitable choice of variables the central equations in this problem can be written in a form where they are identical to the central equations for general (i.e. non-polarized) vacuum Gowdy spacetimes. Using this it is seen that the results of Ringstroem on strong cosmic censorship in the vacuum case have implications for the Einstein-Maxwell case. Working out the geometrical meaning of these analytical results leads to the main conclusion.

  19. Polarized electrogowdy spacetimes censored

    Energy Technology Data Exchange (ETDEWEB)

    Nungesser, Ernesto, E-mail: ernesto.nungesser@aei.mpg.d [Max-Planck-Institut fuer Gravitationsphysik, Albert-Einstein-Institut, Am Muehlenberg 1, 14476 Potsdam (Germany)

    2010-05-01

    A sketch of the proof of strong cosmic censorship is presented for a class of solutions of the Einstein-Maxwell equations, those with polarized Gowdy symmetry. A key element of the argument is the observation that by means of a suitable choice of variables the central equations in this problem can be written in a form where they are identical to the central equations for general (i.e. non-polarized) vacuum Gowdy spacetimes. Using this it is seen that the results of Ringstroem on strong cosmic censorship in the vacuum case have implications for the Einstein-Maxwell case. Working out the geometrical meaning of these analytical results leads to the main conclusion.

  20. Polarization of lanthanum nucleus by dynamic polarization method

    International Nuclear Information System (INIS)

    Adachi, Toshikazu; Ishimoto, Shigeru; Masuda, Yasuhiro; Morimoto, Kimio

    1989-01-01

    Preliminary studies have been carried out concerning the application of a dynamic polarization method to polarizing lanthanum fluoride single crystal to be employed as target in experiments with time reversal invariance. The present report briefly outlines the dynamic polarization method and describes some preliminary studies carried out so far. Dynamic polarization is of particular importance because no techniques are currently available that can produce highly polarized static nucleus. Spin interaction between electrons and protons (nuclei) plays a major role in the dynamic polarization method. In a thermal equilibrium state, electrons are polarized almost completely while most protons are not polarized. Positively polarized proton spin is produced by applying microwave to this system. The most hopeful candidate target material is single crystal of LaF 3 containing neodymium because the crystal is chemically stable and easy to handle. The spin direction is of great importance in experiments with time reversal invariance. The spin of neutrons in the target can be cancelled by adjusting the external magnetic field applied to a frozen polarized target. In a frozen spin state, the polarity decreases slowly with a relaxation time that depends on the external magnetic field and temperature. (N.K.)

  1. Polar bears, Ursus maritimus

    Science.gov (United States)

    Rode, Karyn D.; Stirling, Ian

    2017-01-01

    Polar bears are the largest of the eight species of bears found worldwide and are covered in a pigment-free fur giving them the appearance of being white. They are the most carnivorous of bear species consuming a high-fat diet, primarily of ice-associated seals and other marine mammals. They range throughout the circumpolar Arctic to the southernmost extent of seasonal pack ice.

  2. Polarized advanced fuel reactors

    International Nuclear Information System (INIS)

    Kulsrud, R.M.

    1987-07-01

    The d- 3 He reaction has the same spin dependence as the d-t reaction. It produces no neutrons, so that if the d-d reactivity could be reduced, it would lead to a neutron-lean reactor. The current understanding of the possible suppression of the d-d reactivity by spin polarization is discussed. The question as to whether a suppression is possible is still unresolved. Other advanced fuel reactions are briefly discussed. 11 refs

  3. Polish polar research (outline

    Directory of Open Access Journals (Sweden)

    Krzysztof Ludwik Birkenmajer

    2017-12-01

    Full Text Available The article describes Polish research and discoveries in the Arctic and the Antarctic since the 19th century. The author is a geologist and since 1956 has been engaged in scientific field research on Spitsbergen, Greenland and Antarctica (23 expeditions. For many years chairman of the Committee on Polar Research of the Polish Academy of Sciences, he is now its Honorary Chairman.

  4. South Polar Polygons

    Science.gov (United States)

    2005-01-01

    4 July 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a polgyon-cracked surface, into which deep, somewhat kidney-bean-shaped pits have formed. These are landscapes of the martian south polar residual cap. This view was captured during May 2005. Location near: 86.9oS, 5.1oW Image width: 1.5 km (0.9 mi) Illumination from: upper left Season Southern Spring

  5. Novel polar sedimentary porphyrins

    Science.gov (United States)

    Prowse, W. G.; Maxwell, J. R.

    1989-11-01

    Two polar nickel porphyrins in Messel oil shale are shown to be the C 32 and C 30 components IIIa,b. In the sample examined, component IIIa is by far the major porphyrin alcohol and is present in an abundance similar to that of the major nickel alkyl porphyrin. These primary alcohols, which do not appear to be artifacts, are structurally related to alkyl porphyrins reported previously in Serpiano oil shale.

  6. Polarization properties of linearly polarized parabolic scaling Bessel beams

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Mengwen; Zhao, Daomu, E-mail: zhaodaomu@yahoo.com

    2016-10-07

    The intensity profiles for the dominant polarization, cross polarization, and longitudinal components of modified parabolic scaling Bessel beams with linear polarization are investigated theoretically. The transverse intensity distributions of the three electric components are intimately connected to the topological charge. In particular, the intensity patterns of the cross polarization and longitudinal components near the apodization plane reflect the sign of the topological charge. - Highlights: • We investigated the polarization properties of modified parabolic scaling Bessel beams with linear polarization. • We studied the evolution of transverse intensity profiles for the three components of these beams. • The intensity patterns of the cross polarization and longitudinal components can reflect the sign of the topological charge.

  7. Applications of polarized neutrons

    International Nuclear Information System (INIS)

    Mezei, F.

    1993-01-01

    The additional spin degree of freedom of the neutron can be made use of in neutron scattering work in two fundamental ways: (a) directly for the identification of magnetic scattering effects and (b) indirectly as a spectroscopic tool for modulating and analysing beams. Although strong magnetic scattering contributions can often be studied by unpolarized neutrons, a fully unambiguous separation of nuclear and magnetic phenomena can only be achieved by the additional information provided by polarized neutrons, especially if one of the two kinds of contributions is weak compared to the other. In the most general case a sample with both magnetic and nuclear features can be characterized by as many as 16 independent dynamic correlation functions instead of the single well known S(q, ω) for non-magnetic nuclear scattering only. Polarization analysis in principle allows one to determine all these 16 functions. The indirect applications of polarized neutrons are also steadily gaining importance. The most widely used method of this kind, the application of Larmor precessions for high resolution energy analysis in Neutron Spin Echo spectroscopy opened up a whole new domain in inelastic neutron scattering which was not accessible to any other spectroscopic method with or without neutrons before. (author)

  8. Pliocene geomagnetic polarity epochs

    Science.gov (United States)

    Dalrymple, G.B.; Cox, A.; Doell, Richard R.; Gromme, C.S.

    1967-01-01

    A paleomagnetic and K-Ar dating study of 44 upper Miocene and Pliocene volcanic units from the western United States suggests that the frequency of reversals of the earth's magnetic field during Pliocene time may have been comparable with that of the last 3.6 m.y. Although the data are too limited to permit the formal naming of any new polarity epochs or events, four polarity transitions have been identified: the W10 R/N boundary at 3.7 ?? 0.1 m.y., the A12 N/R boundary at 4.9 ?? 0.1 m.y., the W32 N/R boundary at 9.0 ?? 0.2m.y., and the W36 R/N boundary at 10.8 ?? 0.3 - 1.0 m.y. The loss of absolute resolution of K-Ar dating in older rocks indicates that the use of well defined stratigraphic successions to identify and date polarity transitions will be important in the study of Pliocene and older reversals. ?? 1967.

  9. Covalentely Attached Multilayer Films Comprising Phthalocyanine and Their Photoelectron Conversion Properties

    Institute of Scientific and Technical Information of China (English)

    ZANG Mao-feng; YAO Qiao-hong; YANG Zhao-hui; HUANG Chun-hui; CAO Wei-xiao

    2004-01-01

    The photosensitive multilayer films from sulfonated metal-free, sulfonated copper-, and sulfonated nickel-phthalocyanines were fabricated with diazoresin layer by layer on a substrate via electrostatic interaction by the self-assembly technique. Under UV irradiation, the linkage nature between the layers of the film is converted from the electrostatic bonding to covalent bonding. The covalently attached multilayer films are very stable towards polar solvents and salt aqueous solutions. The photovoltaic properties of the covalently attached film can be determined by means of a traditional three-electrode photoelectrochemical cell in aqueous solutions with KCl as the supporting electrolyte. The photocurrent determination has shown that the sulfonated copper-containing phthalocyanine films possess a higher photocurrent value than sulfonated metalfree and sulfonated nickel-containing phthalocyanine films.

  10. Localization and Orientation of Xanthophylls in a Lipid Bilayer.

    Science.gov (United States)

    Grudzinski, Wojciech; Nierzwicki, Lukasz; Welc, Renata; Reszczynska, Emilia; Luchowski, Rafal; Czub, Jacek; Gruszecki, Wieslaw I

    2017-08-29

    Xanthophylls (polar carotenoids) play diverse biological roles, among which are modulation of the physical properties of lipid membranes and protection of biomembranes against oxidative damage. Molecular mechanisms underlying these functions are intimately related to the localization and orientation of xanthophyll molecules in lipid membranes. In the present work, we address the problem of localization and orientation of two xanthophylls present in the photosynthetic apparatus of plants and in the retina of the human eye, zeaxanthin and lutein, in a single lipid bilayer membrane formed with dimyristoylphosphatidylcholine. By using fluorescence microscopic analysis and Raman imaging of giant unilamellar vesicles, as well as molecular dynamics simulations, we show that lutein and zeaxanthin adopt a very similar transmembrane orientation within a lipid membrane. In experimental and computational approach, the average tilt angle of xanthophylls relative to the membrane normal is independently found to be ~40 deg, and results from hydrophobic mismatch between the membrane thickness and the distance between the terminal hydroxyl groups of the xanthophylls. Consequences of such a localization and orientation for biological activity of xanthophylls are discussed.

  11. Coral lipids and environmental stress.

    Science.gov (United States)

    Harriott, V J

    1993-04-01

    Environmental monitoring of coral reefs is presently limited by difficulties in recognising coral stress, other than by monitoring coral mortality over time. A recent report described an experiment demonstrating that a measured lipid index declined in shaded corals. The technique described might have application in monitoring coral health, with a decline in coral lipid index as an indicator of coral stress. The application of the technique as a practical monitoring tool was tested for two coral species from the Great Barrier Reef. Consistent with the previous results, lipid index for Pocillopora damicornis initially declined over a period of three weeks in corals maintained in filtered seawater in the dark, indicating possible utilization of lipid stored as energy reserves. However, lipid index subsequently rose to near normal levels. In contrast, lipid index of Acropora formosa increased after four weeks in the dark in filtered seawater. The results showed considerable variability in lipid content between samples from the same colony. Results were also found to be dependent on fixation times and sample weight, introducing potential error into the practical application of the technique. The method as described would be unsuitable for monitoring environmental stress in corals, but the search for a practical method to monitor coral health should continue, given its importance in coral reef management.

  12. Spin dynamics in polarized neutron interferometry

    International Nuclear Information System (INIS)

    Buchelt, R.J.

    2000-05-01

    Since its first implementation in 1974, perfect crystal neutron interferometry has become an extremely successful method applicable to a variety of research fields. Moreover, it proved as an illustrative and didactically valuable experiment for the demonstration of the fundamental principles of quantum mechanics, the neutron being an almost ideal probe for the detection of various effects, as it interacts by all four forces of nature. For instance, the first experimental verification of the 4-pi-periodicity of spinor wave functions was performed with perfect crystal neutron interferometry, and it remains the only method known which demonstrates the quantum mechanical wave-particle-duality of massive particles at a macroscopic separation of the coherent matter waves of several centimeters. A particular position is taken herein by polarized neutron interferometry, which as a collective term comprises all techniques and experiments which not only aim at the coherent splitting and macroscopic separation of neutron beams in the interferometer with the purpose of their separate treatment, but which aim to do so with explicit employment of the spin-magnetic properties of the neutron as a fermion. Remarkable aspects may arise, for example, if nuclear and magnetic potentials are concurrently applied to a partial beam of the interferometer: among other results, it is found that - in perfect agreement to the theoretical predictions - the neutron beam leaving the interferometer features non-zero polarization, even if the incident neutron beam, and hence either of the partial beams, is unpolarized. The main emphasis of the present work lies on the development of an appropriate formalism that describes the effect of simultaneous occurrence of nuclear and magnetic interaction on the emerging intensity and polarization for an arbitrary number of sequential magnetic regions, so-called domains. The confrontation with subtle theoretical problems was inevitable during the experimental

  13. Dietary biomagnification of organochlorine contaminants in Alaskan polar bears

    Science.gov (United States)

    Bentzen, T.W.; Follmann, Erich H.; Amstrup, Steven C.; York, G.S.; Wooller, M.J.; Muir, D.C.G.; O'Hara, T. M.

    2008-01-01

    Concentrations of organochlorine contaminants in the adipose tissue of polar bears (Ursus maritimus Phipps, 1774) vary throughout the Arctic. The range in concentrations has not been explained fully by bear age, sex, condition, location, or reproductive status. Dietary pathways expose polar bears to a variety of contaminant profiles and concentrations. Prey range from lower trophic level bowhead whales (Balaena mysticetus L., 1758), one of the least contaminated marine mammals, to highly contaminated upper trophic level ringed seals (Phoca hispida (Schreber, 1775)). We used ??15N and ??13C signatures to estimate the trophic status of 42 polar bears sampled along Alaska's Beaufort Sea coast to determine the relationship between organochlorine concentration and trophic level. The ?? 15N values in the cellular portions of blood ranged from 18.2% to 20.7%. We found strong positive relationships between concentrations of the most recalcitrant polychlorinated biphenyls (PCBs) and ??15N values in models incorporating age, lipid content, and ??13C value. Specifically these models accounted for 67% and 76% of the variation in PCB153 and oxychlordane concentration in male polar bears and 85% and 93% in females, respectively. These results are strong indicators of variation in diet and biomagnification of organochlorines among polar bears related to their sex, age, and trophic position. ?? 2008 NRC.

  14. Review of polarized ammonium target

    International Nuclear Information System (INIS)

    Matsuda, Tatsuo

    1987-01-01

    Recently, ammonia (NH 3 ) and deutron ammonia (ND 3 ), instead of conventional alcohol substances, have been used more frequently as a polarized target substance for experiments of polarization at high energy regions. This article reviews major features of the polarized (deutron) ammonia targets. The dynamic nuclear polarization (DNT) method is widely used in high energy polarization experiments. While only a low polarization degree of hydrogen nucleus of 1.7 percent can be obtained by the Brute force method, DNP can produce polarization as high as ∼ 90 percent (2.5 T, ∼ 200 mK). In 1979, ammonia was irradiated with radiations to form NH 2 free radicals, resulting in the achievement of a high polarization degree of greater than 90 percent (hydrogen). Since then, ammonia and deutron ammonia have increasingly been replacing alcohols including butanol. Irradiation of a target substance with radiations destroys the structure of the substance, leading to a decrease in polarization degree. However, ammonia produces unpaired electrons as a result of irradiation, allowing it to be highly resistant to radiation. This report also present some study results, including observations on effects of radiation on the polarization degree of a target, effects of annealing, and polarization of 14 N. A process for producing an ammonia target is also described. (Nogami, K.)

  15. A Si nanocube array polarizer

    Science.gov (United States)

    Chen, Linghua; Jiang, Yingjie; Xing, Li; Yao, Jun

    2017-10-01

    We have proposed a full dielectric (silicon) nanocube array polarizer based on a silicon dioxide substrate. Each polarization unit column includes a plurality of equal spaced polarization units. By optimizing the length, the width, the height of the polarization units and the center distance of adjacent polarization unit (x direction and y direction), an extinction ratio (ER) of higher than 25dB was obtained theoretically when the incident light wavelength is 1550nm. while for applications of most polarization optical elements, ER above 10dB is enough. With this condition, the polarizer we designed can work in a wide wavelength range from 1509.31nm to 1611.51nm. Compared with the previous polarizer, we have introduced a polarizer which is a full dielectric device, which solves the problems of low efficiency caused by Ohmic loss and weak coupling. Furthermore, compared with the existing optical polarizers, our polarizer has the advantages of thin thickness, small size, light weight, and low processing difficulty, which is in line with the future development trend of optical elements.

  16. Polarization: A must for fusion

    Directory of Open Access Journals (Sweden)

    Didelez J.-P.

    2013-11-01

    Full Text Available The complete polarization of DT fuel would increase the fusion reactivity by 50% in magnetic as well as in inertial confinements. The persistence of polarization in a fusion process could be tested, using a terawatt laser hitting a polarized HD target. The polarized deuterons heated in the plasma induced by the laser can fuse producing a 3He and a neutron in the final state. The angular distribution of the emitted neutrons and the change in the corresponding total Cross Section (CS can sign the polarization persistence. The polarization of solid H2, D2 or T2 Hydrogen isotopes is very difficult. However, it has been possible to polarize HD, a hetero-molecular form of Hydrogen, by static polarization, at very low temperature and very high field. The radioactivity of DT molecules forbids there high polarization by the static method, therefore one has to develop the Dynamic Nuclear Polarization (DNP by RF transitions. The DNP of HD has been investigated in the past. The magnetic properties of HD and DT molecules are very similar, it is therefore expected that any polarization result obtained with HD could be extrapolated to DT.

  17. Natural lipid extracts and biomembrane-mimicking lipid compositions are disposed to form nonlamellar phases, and they release DNA from lipoplexes most efficiently

    Energy Technology Data Exchange (ETDEWEB)

    Koynova, Rumiana; MacDonald, Robert C. (NWU)

    2010-01-18

    A viewpoint now emerging is that a critical factor in lipid-mediated transfection (lipofection) is the structural evolution of lipoplexes upon interacting and mixing with cellular lipids. Here we report our finding that lipid mixtures mimicking biomembrane lipid compositions are superior to pure anionic liposomes in their ability to release DNA from lipoplexes (cationic lipid/DNA complexes), even though they have a much lower negative charge density (and thus lower capacity to neutralize the positive charge of the lipoplex lipids). Flow fluorometry revealed that the portion of DNA released after a 30-min incubation of the cationic O-ethylphosphatidylcholine lipoplexes with the anionic phosphatidylserine or phosphatidylglycerol was 19% and 37%, respectively, whereas a mixture mimicking biomembranes (MM: phosphatidylcholine/phosphatidylethanolamine/phosphatidylserine /cholesterol 45:20:20:15 w/w) and polar lipid extract from bovine liver released 62% and 74%, respectively, of the DNA content. A possible reason for this superior power in releasing DNA by the natural lipid mixtures was suggested by structural experiments: while pure anionic lipids typically form lamellae, the natural lipid mixtures exhibited a surprising predilection to form nonlamellar phases. Thus, the MM mixture arranged into lamellar arrays at physiological temperature, but began to convert to the hexagonal phase at a slightly higher temperature, {approx} 40-45 C. A propensity to form nonlamellar phases (hexagonal, cubic, micellar) at close to physiological temperatures was also found with the lipid extracts from natural tissues (from bovine liver, brain, and heart). This result reveals that electrostatic interactions are only one of the factors involved in lipid-mediated DNA delivery. The tendency of lipid bilayers to form nonlamellar phases has been described in terms of bilayer 'frustration' which imposes a nonzero intrinsic curvature of the two opposing monolayers. Because the stored

  18. Elite Polarization and Public Opinion

    DEFF Research Database (Denmark)

    Robison, Joshua; Mullinix, Kevin

    2016-01-01

    Elite polarization has reshaped American politics and is an increasingly salient aspect of news coverage within the United States. As a consequence, a burgeoning body of research attempts to unravel the effects of elite polarization on the mass public. However, we know very little about how...... polarization is communicated to the public by news media. We report the results of one of the first content analyses to delve into the nature of news coverage of elite polarization. We show that such coverage is predominantly critical of polarization. Moreover, we show that unlike coverage of politics focused...... on individual politicians, coverage of elite polarization principally frames partisan divisions as rooted in the values of the parties rather than strategic concerns. We build on these novel findings with two survey experiments exploring the influence of these features of polarization news coverage on public...

  19. The polarization of fast neutrons

    International Nuclear Information System (INIS)

    Talov, V.V.

    2001-01-01

    It is insufficient to know coordinates and momentum to describe a state of a neutron. It is necessary to define a spin orientation. As far as it is known from quantum mechanics, a half spin has a projection in the positive direction or in the negative direction. The probability of both projections in an unpolarized beam is equal. If a direction exists, in which the projection is more probably then beam is called polarized in this direction. It is essential to know polarization of neutrons for characteristics of a neutron source, which is emitting it. The question of polarization of fast neutrons came up in 50's. The present work is the review of polarization of fast neutrons and methods of polarization analysis. This also includes information about polarization of fast neutrons from first papers, which described polarization in the D(d,n) 3 He, 7 Li (p,n) 7 Be, T(p,n) 3 He reactions. (authors)

  20. Lipid metabolism in cancer cachexia.

    OpenAIRE

    Mulligan, H. D.; Beck, S. A.; Tisdale, M. J.

    1992-01-01

    The effect of cancer cachexia on the oxidative metabolism of lipids has been studied in mice transplanted either with the MAC16 adenocarcinoma, which induces profound loss of body weight and depletion of lipid stores, or the MAC13 adenocarcinoma, which is the same histological type, but which grows without an effect on host body weight or lipid stores. While oxidation of D-[U-14C]glucose did not differ between animals bearing tumours of either type and non-tumour bearing controls, oxidation o...

  1. A lung cancer risk classifier comprising genome maintenance genes measured in normal bronchial epithelial cells.

    Science.gov (United States)

    Yeo, Jiyoun; Crawford, Erin L; Zhang, Xiaolu; Khuder, Sadik; Chen, Tian; Levin, Albert; Blomquist, Thomas M; Willey, James C

    2017-05-02

    Annual low dose CT (LDCT) screening of individuals at high demographic risk reduces lung cancer mortality by more than 20%. However, subjects selected for screening based on demographic criteria typically have less than a 10% lifetime risk for lung cancer. Thus, there is need for a biomarker that better stratifies subjects for LDCT screening. Toward this goal, we previously reported a lung cancer risk test (LCRT) biomarker comprising 14 genome-maintenance (GM) pathway genes measured in normal bronchial epithelial cells (NBEC) that accurately classified cancer (CA) from non-cancer (NC) subjects. The primary goal of the studies reported here was to optimize the LCRT biomarker for high specificity and ease of clinical implementation. Targeted competitive multiplex PCR amplicon libraries were prepared for next generation sequencing (NGS) analysis of transcript abundance at 68 sites among 33 GM target genes in NBEC specimens collected from a retrospective cohort of 120 subjects, including 61 CA cases and 59 NC controls. Genes were selected for analysis based on contribution to the previously reported LCRT biomarker and/or prior evidence for association with lung cancer risk. Linear discriminant analysis was used to identify the most accurate classifier suitable to stratify subjects for screening. After cross-validation, a model comprising expression values from 12 genes (CDKN1A, E2F1, ERCC1, ERCC4, ERCC5, GPX1, GSTP1, KEAP1, RB1, TP53, TP63, and XRCC1) and demographic factors age, gender, and pack-years smoking, had Receiver Operator Characteristic area under the curve (ROC AUC) of 0.975 (95% CI: 0.96-0.99). The overall classification accuracy was 93% (95% CI 88%-98%) with sensitivity 93.1%, specificity 92.9%, positive predictive value 93.1% and negative predictive value 93%. The ROC AUC for this classifier was significantly better (p < 0.0001) than the best model comprising demographic features alone. The LCRT biomarker reported here displayed high accuracy and ease

  2. Polarized proton target-III. Operations manual, revision B

    International Nuclear Information System (INIS)

    Hill, D.; Moretti, A.; Onesto, F.; Rynes, P.

    1978-01-01

    The manual presented contains certain standard operating procedures for the vacuum, cryogenic, and electronic systems of PPT-III. In total, these systems comprise the following major divisions: (1) the target cryostat; (2) the 4 He pumping system; (3) the 3 He pumping system; (4) the remote monitors and controls; (5) the microwave system; (6) the magnet and power supply; (7) the computerized polarization monitor; (8) the 4 He liquefier and gas recovery system; and (9) miscellaneous auxiliary equipment

  3. Molecular dynamics study of structure and vibrational spectra at zwitterionoic lipid/aqueous KCl, NaCl, and CaCl2 solution interfaces

    Science.gov (United States)

    Ishiyama, Tatsuya; Shirai, Shinnosuke; Okumura, Tomoaki; Morita, Akihiro

    2018-06-01

    Molecular dynamics (MD) simulations of KCl, NaCl, and CaCl2 solution/dipalmytoylphosphatidylcholine lipid interfaces were performed to analyze heterodyne-detected vibrational sum frequency generation (HD-VSFG) spectra in relation to the interfacial water structure. The present MD simulation well reproduces the experimental spectra and elucidates a specific cation effect on the interfacial structure. The K+, Na+, and Ca2+ cation species penetrate in the lipid layer more than the anions in this order, due to the electrostatic interaction with negative polar groups of lipid, and the electric double layer between the cations and anions cancels the intrinsic orientation of water at the water/lipid interface. These mechanisms explain the HD-VSFG spectrum of the water/lipid interface and its spectral perturbation by adding the ions. The lipid monolayer reverses the order of surface preference of the cations at the solution/lipid interface from that at the solution/air interface.

  4. Muscle Lipid Metabolism: Role of Lipid Droplets and Perilipins

    Directory of Open Access Journals (Sweden)

    Pablo Esteban Morales

    2017-01-01

    Full Text Available Skeletal muscle is one of the main regulators of carbohydrate and lipid metabolism in our organism, and therefore, it is highly susceptible to changes in glucose and fatty acid (FA availability. Skeletal muscle is an extremely complex tissue: its metabolic capacity depends on the type of fibers it is made up of and the level of stimulation it undergoes, such as acute or chronic contraction. Obesity is often associated with increased FA levels, which leads to the accumulation of toxic lipid intermediates, oxidative stress, and autophagy in skeletal fibers. This lipotoxicity is one of the most common causes of insulin resistance (IR. In this scenario, the “isolation” of certain lipids in specific cell compartments, through the action of the specific lipid droplet, perilipin (PLIN family of proteins, is conceived as a lifeguard compensatory strategy. In this review, we summarize the cellular mechanism underlying lipid mobilization and metabolism inside skeletal muscle, focusing on the function of lipid droplets, the PLIN family of proteins, and how these entities are modified in exercise, obesity, and IR conditions.

  5. Nucleic acids encoding phloem small RNA-binding proteins and transgenic plants comprising them

    Science.gov (United States)

    Lucas, William J.; Yoo, Byung-Chun; Lough, Tony J.; Varkonyi-Gasic, Erika

    2007-03-13

    The present invention provides a polynucleotide sequence encoding a component of the protein machinery involved in small RNA trafficking, Cucurbita maxima phloem small RNA-binding protein (CmPSRB 1), and the corresponding polypeptide sequence. The invention also provides genetic constructs and transgenic plants comprising the polynucleotide sequence encoding a phloem small RNA-binding protein to alter (e.g., prevent, reduce or elevate) non-cell autonomous signaling events in the plants involving small RNA metabolism. These signaling events are involved in a broad spectrum of plant physiological and biochemical processes, including, for example, systemic resistance to pathogens, responses to environmental stresses, e.g., heat, drought, salinity, and systemic gene silencing (e.g., viral infections).

  6. Palladium catalyst system comprising zwitterion and/or acid-functionalized ionic liquid

    DEFF Research Database (Denmark)

    2011-01-01

    The present invention concerns a catalyst system in particular a catalyst system comprising Palladium (Pd), a zwitterion and/or an acid-functionalized ionic liquid, and one or more phosphine ligands, wherein the Pd catalyst can be provided by a complex precursor, such as Pd(CH3COO)2, PdCI2, Pd(CH3......COCHCOCH3), Pd (CF3COO)2, Pd(PPh3)4 or Pd2(dibenzylideneacetone)3. Such catalyst systems can be used for e.g. alkoxycarbonylation reactions, carboxylation reactions, and/or in a co-polymerization reaction, e.g. in the production of methyl propionate and/or propanoic acid, optionally in processes forming...... methyl methacrylate and/or methacrylic acid. Catalyst systems according to the invention are suitable for reactions forming separable product and catalyst phases and supported ionic liquid phase SILP applications....

  7. PREPARATION AND CHARACTERIZATION OF COMPOSITES COMPRISING MODIFIED HARDWOOD AND WOOD POLYMERS/POLY(VINYL CHLORIDE

    Directory of Open Access Journals (Sweden)

    Ruxanda Bodîrlău

    Full Text Available Chemical modification of hardwood sawdust from ash-tree species was carried out with a solution of maleic anhydride in acetone. Wood polymers, lignin, and cellulose were isolated from the wood sawdust and modified by the same method. Samples were characterized by Fourier transform infrared spectroscopy (FTIR, providing evidence that maleic anhydride esterifies the free hydroxyl groups of the wood polymer components. Composites comprising chemically modified wood sawdust and wood polymers (cellulose, lignin-as variable weight percentages-, and poly (vinyl chloride were obtained and further characterized by using FTIR spectroscopy and scanning electron microscopy (SEM. The thermal behavior of composites was investigated by using the thermogravimetric analysis (TGA. In all cases, thermal properties were affected by fillers addition.

  8. Mycobacterium tuberculosis Lineage 4 comprises globally distributed and geographically restricted sublineages

    Science.gov (United States)

    Coscolla, Mireia; Liu, Qingyun; Trauner, Andrej; Fenner, Lukas; Rutaihwa, Liliana; Borrell, Sonia; Luo, Tao; Gao, Qian; Kato-Maeda, Midori; Ballif, Marie; Egger, Matthias; Macedo, Rita; Mardassi, Helmi; Moreno, Milagros; Tudo Vilanova, Griselda; Fyfe, Janet; Globan, Maria; Thomas, Jackson; Jamieson, Frances; Guthrie, Jennifer L.; Asante-Poku, Adwoa; Yeboah-Manu, Dorothy; Wampande, Eddie; Ssengooba, Willy; Joloba, Moses; Henry Boom, W.; Basu, Indira; Bower, James; Saraiva, Margarida; Vaconcellos, Sidra E. G.; Suffys, Philip; Koch, Anastasia; Wilkinson, Robert; Gail-Bekker, Linda; Malla, Bijaya; Ley, Serej D.; Beck, Hans-Peter; de Jong, Bouke C.; Toit, Kadri; Sanchez-Padilla, Elisabeth; Bonnet, Maryline; Gil-Brusola, Ana; Frank, Matthias; Penlap Beng, Veronique N.; Eisenach, Kathleen; Alani, Issam; Wangui Ndung’u, Perpetual; Revathi, Gunturu; Gehre, Florian; Akter, Suriya; Ntoumi, Francine; Stewart-Isherwood, Lynsey; Ntinginya, Nyanda E.; Rachow, Andrea; Hoelscher, Michael; Cirillo, Daniela Maria; Skenders, Girts; Hoffner, Sven; Bakonyte, Daiva; Stakenas, Petras; Diel, Roland; Crudu, Valeriu; Moldovan, Olga; Al-Hajoj, Sahal; Otero, Larissa; Barletta, Francesca; Jane Carter, E.; Diero, Lameck; Supply, Philip; Comas, Iñaki; Niemann, Stefan; Gagneux, Sebastien

    2016-01-01

    Generalist and specialist species differ in the breadth of their ecological niche. Little is known about the niche width of obligate human pathogens. Here we analyzed a global collection of Mycobacterium tuberculosis Lineage 4 clinical isolates, the most geographically widespread cause of human tuberculosis. We show that Lineage 4 comprises globally distributed and geographically restricted sublineages, suggesting a distinction between generalists and specialists. Population genomic analyses showed that while the majority of human T cell epitopes were conserved in all sublineages, the proportion of variable epitopes was higher in generalists. Our data further support a European origin for the most common generalist sublineage. Hence, the global success of Lineage 4 reflects distinct strategies adopted by different sublineages and the influence of human migration. PMID:27798628

  9. Apparatus comprising trace element dosage and method for treating raw water in biofilter

    DEFF Research Database (Denmark)

    2015-01-01

    the inlet (2) to the outlet (3) or in the reverse direction, - the trace element dosage device (13) is positioned upstream of the porous filter material and microbial biomass and is configured to dose trace element(s) to the water flowing through the filter. A method for treating raw water by microbial......Apparatus for treating raw water in a biofilter The present invention relates to an apparatus in which raw water is treated through microbial activity where microbial activity is controlled by nutrients and other parameters. Some of the nutrients controlling the microbial activity are trace...... elements such as certain metals (Cu, Co, Cr, Mo, Ni, W, Zn or a mixture thereof). The apparatus comprising - a volume provided with an inlet (2) for raw water and an outlet (3) for water having been subjected to microbial activity, a filter and a trace element dosage device (13) are placed in this volume...

  10. Functional Analysis of Genes Comprising the Locus of Heat Resistance in Escherichia coli.

    Science.gov (United States)

    Mercer, Ryan; Nguyen, Oanh; Ou, Qixing; McMullen, Lynn; Gänzle, Michael G

    2017-10-15

    The locus of heat resistance (LHR) is a 15- to 19-kb genomic island conferring exceptional heat resistance to organisms in the family Enterobacteriaceae , including pathogenic strains of Salmonella enterica and Escherichia coli The complement of LHR-comprising genes that is necessary for heat resistance and the stress-induced or growth-phase-induced expression of LHR-comprising genes are unknown. This study determined the contribution of the seven LHR-comprising genes yfdX1 GI , yfdX2 , hdeD GI , orf11 , trx GI , kefB , and psiE GI by comparing the heat resistances of E. coli strains harboring plasmid-encoded derivatives of the different LHRs in these genes. (Genes carry a subscript "GI" [genomic island] if an ortholog of the same gene is present in genomes of E. coli ) LHR-encoded heat shock proteins sHSP20, ClpK GI , and sHSP GI are not sufficient for the heat resistance phenotype; YfdX1, YfdX2, and HdeD are necessary to complement the LHR heat shock proteins and to impart a high level of resistance. Deletion of trx GI , kefB , and psiE GI from plasmid-encoded copies of the LHR did not significantly affect heat resistance. The effect of the growth phase and the NaCl concentration on expression from the putative LHR promoter p2 was determined by quantitative reverse transcription-PCR and by a plasmid-encoded p2:GFP promoter fusion. The expression levels of exponential- and stationary-phase E. coli cells were not significantly different, but the addition of 1% NaCl significantly increased LHR expression. Remarkably, LHR expression in E. coli was dependent on a chromosomal copy of evgA In conclusion, this study improved our understanding of the genes required for exceptional heat resistance in E. coli and factors that increase their expression in food. IMPORTANCE The locus of heat resistance (LHR) is a genomic island conferring exceptional heat resistance to several foodborne pathogens. The exceptional level of heat resistance provided by the LHR questions the

  11. Ion source using a hollow cathode discharge system and especially, particle accelerator comprising said source

    International Nuclear Information System (INIS)

    Mourier, Georges.

    1975-01-01

    An ion source provided with a hollow cathode discharge system is presented. The ion extraction system is designed in view of generating a beam directed towards a point of use located far from the point of ion production. Said source essentially comprises two cathodes facing each other, an anode at a continuous voltage with respect to the cathodes, a heated filament beyond the cathode on the path of the extracted beam, and a grid between said filament and cathode. The ion extraction is limited to a certain portion of the ions present inside the plasma, so as the discharge to continue to be sustained by itself. For that purpose pierced cathodes are used, with a transparency (the ratio of the hole area to the whole cathode area) not much higher than 50% [fr

  12. Position sensitive detector with semiconductor and image electron tube comprising such a detector

    International Nuclear Information System (INIS)

    Roziere, Guy.

    1977-01-01

    This invention concerns a position sensitive detector comprising a semiconducting substrate. It also concerns the electron tubes in which the detector may be incorporated in order to obtain an image formed at the tube input by an incident flux of particles or radiation. When a charged particle or group of such particles, electrons in particular, enter the space charge region of an inversely biased semiconductor diode, the energy supplied by these particles releases in the diode a certain number of electron-hole pairs which move in the field existing in the area towards the diode contacts. A corresponding current arises in the connections of this diode which constitutes the signal corresponding to the incident energy. Such a tube or chain of tubes is employed in nuclear medicine for observing parts of the human body, particularly by gamma radiation [fr

  13. INFLUENCE OF BIOPREPARATIONS FROM DRY SOYBEAN AND SUNFLOWER LECITHINS ON SERUM LIPIDS COMPOSITION

    Directory of Open Access Journals (Sweden)

    H. V. Dziak

    2014-04-01

    Full Text Available Dry lecithin, which is a mixture of polar phospholipids, neutral lipids, free fatty acids, glycolipids, carbohydrates, and small amounts of moisture, is a promising object for biologic-hepatoprotectors creation. One of its pharmacological activity displays is its influence on serum lipids, in particular transport forms of these lipids. The influence of dry soy lecithin and sunflower on hyperlipoproteinemia ratio and other lipid disorders is studied. It is shown that low-fat dry soybean lecithin showed hypocholesterolemic activity against all studied forms of serum cholesterol. Nonfat dry sunflower lecithin had similar but somewhat less prominent effect. However reduced concentration of high density lipoprotein cholesterol under sunflower lecithin developed right before soya lecithin. Both lecithin prevented the development of dyslipidemia induced carbon tetrachloride.

  14. Kinetic analysis of overlapping multistep thermal decomposition comprising exothermic and endothermic processes: thermolysis of ammonium dinitramide.

    Science.gov (United States)

    Muravyev, Nikita V; Koga, Nobuyoshi; Meerov, Dmitry B; Pivkina, Alla N

    2017-01-25

    This study focused on kinetic modeling of a specific type of multistep heterogeneous reaction comprising exothermic and endothermic reaction steps, as exemplified by the practical kinetic analysis of the experimental kinetic curves for the thermal decomposition of molten ammonium dinitramide (ADN). It is known that the thermal decomposition of ADN occurs as a consecutive two step mass-loss process comprising the decomposition of ADN and subsequent evaporation/decomposition of in situ generated ammonium nitrate. These reaction steps provide exothermic and endothermic contributions, respectively, to the overall thermal effect. The overall reaction process was deconvoluted into two reaction steps using simultaneously recorded thermogravimetry and differential scanning calorimetry (TG-DSC) curves by considering the different physical meanings of the kinetic data derived from TG and DSC by P value analysis. The kinetic data thus separated into exothermic and endothermic reaction steps were kinetically characterized using kinetic computation methods including isoconversional method, combined kinetic analysis, and master plot method. The overall kinetic behavior was reproduced as the sum of the kinetic equations for each reaction step considering the contributions to the rate data derived from TG and DSC. During reproduction of the kinetic behavior, the kinetic parameters and contributions of each reaction step were optimized using kinetic deconvolution analysis. As a result, the thermal decomposition of ADN was successfully modeled as partially overlapping exothermic and endothermic reaction steps. The logic of the kinetic modeling was critically examined, and the practical usefulness of phenomenological modeling for the thermal decomposition of ADN was illustrated to demonstrate the validity of the methodology and its applicability to similar complex reaction processes.

  15. Dynamics, Surface Electrostatics and Phase Properties of Nanoscale Curved Lipid Bilayers

    Science.gov (United States)

    Koolivand, Amir

    Surface electrostatic potential of a lipid bilayer governs many vital functions of living cells. Several classes of proteins are known of exhibiting strong binding preferences to curved lipid bilayer surfaces. In this project we employed electron paramagnetic resonance (EPR) of a recently introduced phospholipid (IMTSL-PTE) bearing a pH-sensitive nitroxide covalently attached to the lipid head group to measure the surface electrostatics of the lipid membrane and nanopore-confined lipid bilayers as a function of the bilayer curvature. The pKa of the ionizable group of this lipid-based spin probe is reporting on the bilayer surface electrostatics potential by changes in the EPR spectra. Specifically, both rotational dynamics and magnetic parameters of the nitroxide are affected by the probe protonation. Effect of curvature on the surface electrostatic potential and dynamics of lipid bilayer was studied for POPG and DMPG unilamellar vesicles (ULVs). It was found that the magnitude of the negative surface electrostatic potential increased upon decrease in the vesicle diameter for the bilayers in the fluid phase; however, no significant changes were observed for DMPG ULVs in a gel phase. We speculate that biologically relevant fluid bilayer phase allows for a larger variability in the lipid packing density in the lipid polar head group region than a more ordered gel phase and it is likely that the lipid flip-flop is responsible for pH equilibration of IMTSL-PTE. The kinetic EPR study of nitroxide reduction showed that the rate of flip-flop is in the order of 10-5 s-1. The flip-flop rate constant increases when vesicle size deceases. Oxygen permeability measured by X-ban EPR decreases in higher curved vesicles---an observation that is consistent with a tighter packing in smaller vesicles. Partitioning of a small nitroxide molecule TEMPO into ULVs was measured by X-band (9 GHz) and W-band (95 GHz) EPR spectroscopy. The partitioning coefficient of this probe in the lipid

  16. Blood lipids and prostate cancer

    DEFF Research Database (Denmark)

    Bull, Caroline J; Bonilla, Carolina; Holly, Jeff M P

    2016-01-01

    Genetic risk scores were used as unconfounded instruments for specific lipid traits (Mendelian randomization) to assess whether circulating lipids causally influence prostate cancer risk. Data from 22,249 prostate cancer cases and 22,133 controls from 22 studies within the international PRACTICAL...... into logistic regression models to estimate the presence (and direction) of any causal effect of each lipid trait on prostate cancer risk. There was weak evidence for an association between the LDL genetic score and cancer grade: the odds ratio (OR) per genetically instrumented standard deviation (SD) in LDL.......95, 3.00; P = 0.08). The rs12916-T variant in 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) was inversely associated with prostate cancer (OR: 0.97; 95% CI: 0.94, 1.00; P = 0.03). In conclusion, circulating lipids, instrumented by our genetic risk scores, did not appear to alter prostate cancer risk...

  17. Coronal Polarization of Pseudostreamers and the Solar Polar Field Reversal

    Science.gov (United States)

    Rachmeler, L. A.; Guennou, C.; Seaton, D. B.; Gibson, S. E.; Auchere, F.

    2016-01-01

    The reversal of the solar polar magnetic field is notoriously hard to pin down due to the extreme viewing angle of the pole. In Cycle 24, the southern polar field reversal can be pinpointed with high accuracy due to a large-scale pseudostreamer that formed over the pole and persisted for approximately a year. We tracked the size and shape of this structure with multiple observations and analysis techniques including PROBA2/SWAP EUV images, AIA EUV images, CoMP polarization data, and 3D tomographic reconstructions. We find that the heliospheric field reversed polarity in February 2014, whereas in the photosphere, the last vestiges of the previous polar field polarity remained until March 2015. We present here the evolution of the structure and describe its identification in the Fe XII 1074nm coronal emission line, sensitive to the Hanle effect in the corona.

  18. System for measuring the proton polarization in a polarized target

    International Nuclear Information System (INIS)

    Karnaukhov, I.M.; Lukhanin, A.A.; Telegin, Yu.N.; Trotsenko, V.I.; Chechetenko, V.F.

    1984-01-01

    The system for measuring the proton polarization in a polarized target representing the high-sensitivity nuclear magnetic resonance (NMR) is described Q-meter with series connection and a circuit for measuring system resonance characteristic is used for NMR-absorption signal recording. Measuring coil is produced of a strip conductor in order to obtain uniform system sensitivity to polarization state in all target volume and improve signal-to-noise ratio. Polarization measuring system operates ion-line with the M-6000 computer. The total measuring error for the value of free proton polarization in target taking into account the error caused by local depolarization of working substance under irradiation by high-intense photon beam is <= 6%. Long-term application of the described system for measuring the proton polarization in the LUEh-20000 accelerator target used in the pion photoproduction experiments has demonstrated its high reliability

  19. Circularly polarized antennas

    CERN Document Server

    Gao, Steven; Zhu, Fuguo

    2013-01-01

    This book presents a comprehensive insight into the design techniques for different types of CP antenna elements and arrays In this book, the authors address a broad range of topics on circularly polarized (CP) antennas. Firstly, it introduces to the reader basic principles, design techniques and characteristics of various types of CP antennas, such as CP patch antennas, CP helix antennas, quadrifilar helix antennas (QHA), printed quadrifilar helix antennas (PQHA), spiral antenna, CP slot antennas, CP dielectric resonator antennas, loop antennas, crossed dipoles, monopoles and CP horns. Adva

  20. Spin-polarized SEM

    International Nuclear Information System (INIS)

    Konoto, Makoto

    2007-01-01

    Development of highly effective evaluation technology of magnetic structures on a nanometric scale is a key to understanding spintronics and related phenomena. A high-resolution spin-polarized scanning electron microscope (spin SEM) developed recently is quite suitable for probing such nanostructures because of the capability of analyzing local magnetization vectors in three dimensions. Utilizing the spin SEM, a layered antiferromagnetic structure with the 1nm-alternation of bilayer-sheet magnetization has been successfully resolved. The real-space imaging with full analysis of the temperature-dependent magnetization vectors will be demonstrated. (author)

  1. Polarization recovery through scattering media.

    Science.gov (United States)

    de Aguiar, Hilton B; Gigan, Sylvain; Brasselet, Sophie

    2017-09-01

    The control and use of light polarization in optical sciences and engineering are widespread. Despite remarkable developments in polarization-resolved imaging for life sciences, their transposition to strongly scattering media is currently not possible, because of the inherent depolarization effects arising from multiple scattering. We show an unprecedented phenomenon that opens new possibilities for polarization-resolved microscopy in strongly scattering media: polarization recovery via broadband wavefront shaping. We demonstrate focusing and recovery of the original injected polarization state without using any polarizing optics at the detection. To enable molecular-level structural imaging, an arbitrary rotation of the input polarization does not degrade the quality of the focus. We further exploit the robustness of polarization recovery for structural imaging of biological tissues through scattering media. We retrieve molecular-level organization information of collagen fibers by polarization-resolved second harmonic generation, a topic of wide interest for diagnosis in biomedical optics. Ultimately, the observation of this new phenomenon paves the way for extending current polarization-based methods to strongly scattering environments.

  2. The TULIP superfamily of eukaryotic lipid-binding proteins as a mediator of lipid sensing and transport.

    Science.gov (United States)

    Alva, Vikram; Lupas, Andrei N

    2016-08-01

    The tubular lipid-binding (TULIP) superfamily has emerged in recent years as a major mediator of lipid sensing and transport in eukaryotes. It currently encompasses three protein families, SMP-like, BPI-like, and Takeout-like, which share a common fold. This fold consists of a long helix wrapped in a highly curved anti-parallel β-sheet, enclosing a central, lipophilic cavity. The SMP-like proteins, which include subunits of the ERMES complex and the extended synaptotagmins (E-Syts), appear to be mainly located at membrane contacts sites (MCSs) between organelles, mediating inter-organelle lipid exchange. The BPI-like proteins, which include the bactericidal/permeability-increasing protein (BPI), the LPS (lipopolysaccharide)-binding protein (LBP), the cholesteryl ester transfer protein (CETP), and the phospholipid transfer protein (PLTP), are either involved in innate immunity against bacteria through their ability to sense lipopolysaccharides, as is the case for BPI and LBP, or in lipid exchange between lipoprotein particles, as is the case for CETP and PLTP. The Takeout-like proteins, which are comprised of insect juvenile hormone-binding proteins and arthropod allergens, transport, where known, lipid hormones to target tissues during insect development. In all cases, the activity of these proteins is underpinned by their ability to bind large, hydrophobic ligands in their central cavity and segregate them away from the aqueous environment. Furthermore, where they are involved in lipid exchange, recent structural studies have highlighted their ability to establish lipophilic, tubular channels, either between organelles in the case of SMP domains or between lipoprotein particles in the case of CETP. Here, we review the current knowledge on the structure, versatile functions, and evolution of the TULIP superfamily. We propose a deep evolutionary split in this superfamily, predating the Last Eukaryotic Common Ancestor, between the SMP-like proteins, which act on

  3. Bioactive Lipids in Dairy Fat

    DEFF Research Database (Denmark)

    Hellgren, Lars; Nordby, Pernille

    2017-01-01

    Milk fat is the most important energy source for the newborn infant beside its important role as energy source, milk fat also contain a range of bioactive lipids, that potentially can modulate the immune response and metabolic regulation in the child. In this chapter we review the literature on b...... on bioactive dairy fatty acids: conjugated linoleic acid, branched chained and odd chained fatty acids, as well as bioactive complex lipids such as sphingomyelin and gangliosides....

  4. Peculiarities of annihilation of polarized positronium in polarized media

    International Nuclear Information System (INIS)

    Silenko, A.Ya.

    2005-01-01

    Features of positronium annihilation (PA) in polarized media are investigated. Strong exchange interaction with nonpaired electrons of paramagnetic atoms essentially accelerates the PA in comparison with annihilation of free positrons. The value of the spin projection on the direction of polarized nonpaired electrons has essential effect on the orthopositronium lifetime and on the width of the gamma spectrum annihilation line. It is shown that these features of PA permit to use it for studying the paramagnetic polarization [ru

  5. Antitumor Lipids--Structure, Functions, and Medical Applications.

    Science.gov (United States)

    Kostadinova, Aneliya; Topouzova-Hristova, Tanya; Momchilova, Albena; Tzoneva, Rumiana; Berger, Martin R

    2015-01-01

    Cell proliferation and metastasis are considered hallmarks of tumor progression. Therefore, efforts have been made to develop novel anticancer drugs that inhibit both the proliferation and the motility of tumor cells. Synthetic antitumor lipids (ATLs), which are chemically divided into two main classes, comprise (i) alkylphospholipids (APLs) and (ii) alkylphosphocholines (APCs). They represent a new entity of drugs with distinct antiproliferative properties in tumor cells. These compounds do not interfere with the DNA or mitotic spindle apparatus of the cell, instead, they incorporate into cell membranes, where they accumulate and interfere with lipid metabolism and lipid-dependent signaling pathways. Recently, it has been shown that the most commonly studied APLs inhibit proliferation by inducing apoptosis in malignant cells while leaving normal cells unaffected and are potent sensitizers of conventional chemo- and radiotherapy, as well as of electrical field therapy. APLs resist catabolic degradation to a large extent, therefore accumulate in the cell and interfere with lipid-dependent survival signaling pathways, notably PI3K-Akt and Raf-Erk1/2, and de novo phospholipid biosynthesis. They are internalized in the cell membrane via raft domains and cause downstream reactions as inhibition of cell growth and migration, cell cycle arrest, actin stress fibers collapse, and apoptosis. This review summarizes the in vitro, in vivo, and clinical trials of most common ATLs and their mode of action at molecular and biochemical levels. © 2015 Elsevier Inc. All rights reserved.

  6. [Lipids of Aureobasidium (Pullularia) pullulans].

    Science.gov (United States)

    Elinov, N P; Iurlova, N A; Efimova, T P

    1975-01-01

    Fractional composition of free and bound lipids was studied in Aureobasidium (Pullularia) pullulans 8 by preparative TLC on Silufol. Bound lipids contained a fraction (27.76 +/- 0.5%) of dark brown colour, similar to melanin. The composition of fatty acids was studied by GLC. The following fatty acids were identified and determined quantitatively: C12:0, C14:0, C15:0, C16:0, C18:0, C18:1+C15:2. The following fatty acids predominated in free and bound lipids: C16:0, C18:1+C18:2. The ratio between unsaturated and saturated fatty acids in all fractions of free and bound lipids was more than unity. The following parameters were determined for lipids; ester number (173.89 and 178.53); iodine number (44.1 and 33.10), and saponification number (181.17 and 206.03) (the values are given for free and bound lipids, respectively).

  7. Piezoelectric antibacterial fabric comprised of poly(l-lactic acid) yarn

    Science.gov (United States)

    Ando, Masamichi; Takeshima, Satoshi; Ishiura, Yutaka; Ando, Kanako; Onishi, Osamu

    2017-10-01

    A lactic acid monomer has an asymmetric carbon in the molecule, so there are optical isomer l- and d-type. The most widely used poly(lactic acid) (PLA) for commercial applications is poly(l-lactic acid) (PLLA). PLLA is the polymerization product of l-lactide. Certain treatments of PLLA can yield a film that exhibits shear piezoelectricity. Thus, piezoelectric PLLA fiber can be generated by micro slitting piezoelectric PLLA films or by a melt spinning method. We prepared left-handed helical multi fiber yarn (S-yarn) and right-handed helical yarn (Z-yarn) using piezoelectric PLLA fiber. PLLA exhibited shear mode piezoelectricity, causing the electric polarity of the yarn surface to be reversed on the S-yarn and Z-yarn when tension was applied. An SZ-yarn was produced by combining the S-yarn and Z-yarn, and fabric was prepared using the SZ-yarn. This study demonstrated that the fabric has a strong antibacterial effect, which is thought to be due to the strong electric field between the yarns. The field is generated by a piezoelectric effect when the fabric was extended and contracted.

  8. "Lipid raft aging" in the human frontal cortex during nonpathological aging: gender influences and potential implications in Alzheimer's disease.

    Science.gov (United States)

    Díaz, Mario; Fabelo, Noemí; Ferrer, Isidre; Marín, Raquel

    2018-07-01

    Lipid rafts are highly dynamic membrane domains featured by distinctive biochemical composition and physicochemical properties compared with the surrounding plasma membrane. These microstructures are associated not only with cellular signaling and communication in normal nerve cells but also with pathological processing of amyloid precursor protein in Alzheimer's disease. Using lipid rafts isolated from human frontal cortex in nondemented subjects aging 24 to 85 years, we demonstrate here that lipid structure of lipid rafts undergo significant alterations of specific lipid classes and phospholipid-bound fatty acids as brain cortex correlating with aging. Main changes affect levels of plasmalogens, polyunsaturated fatty acids (especially docosahexaenoic acid and arachidonic acid), total polar lipids (mainly phosphatidylinositol, sphingomyelin, sulfatides, and cerebrosides), and total neutral lipids (particularly cholesterol and sterol esters). Besides, relevant relationships between main fatty acids and/or lipid classes were altered in an age-related manner. This "lipid raft aging" exhibits clear gender differences and appear to be more pronounced in women than in men, especially in older (postmenopausal) women. The outcomes led us to conclude that human cortical lipid rafts are modified by aging in a gender-dependent fashion. Given the central role of bilayer lipid matrix in lipid rafts functionality and neuronal signaling, we hypothesize that these findings might underlie the higher prevalence of cognitive decline evolving toward Alzheimer's disease in postmenopausal women. Copyright © 2018 Elsevier Inc. All rights reserved.

  9. Defining Lipid Transport Pathways in Animal Cells

    Science.gov (United States)

    Pagano, Richard E.; Sleight, Richard G.

    1985-09-01

    A new technique for studying the metabolism and intracellular transport of lipid molecules in living cells based on the use of fluorescent lipid analogs is described. The cellular processing of various intermediates (phosphatidic acid and ceramide) and end products (phosphatidylcholine and phosphatidylethanolamine) in lipid biosynthesis is reviewed and a working model for compartmentalization during lipid biosynthesis is presented.

  10. Polarized tagged photons

    International Nuclear Information System (INIS)

    Maximon, L.C.; Ganz, Eric; Aniel, Thierry; Miniac, Arlette de.

    1982-03-01

    We consider in detail the differential cross section for polarized bremsstrahlung for angles and energies in the range of interest for a tagging system and derive a high energy, small angle approximation for this cross section. We use these approximations to determine the maxima and minima of the cross sections for these two polarization states, dσperpendicular and dσparallel, and to evaluate these cross sections at the extrema. It is shown that both dσperpendicular and dσparallel have a very sharp dip in the region of small momentum transfers. However, their behavior in the region of the dip, as a function of the azimuthal angle phi, is quite different over most of the photon spectrum. The cross section dσperpendicular behaves similarly to the cross section for unpolarized photons in that as phi increases, the sharp dip vanishes, the minimum fuses with the second maximum, and the cross section then has only a single maximum. In contrast, the sharp dip in the cross section dσparallel remains as phi increases. Coulomb corrections to the Born approximation are considered, and do not fill in these dips

  11. Lipidomics Unravels the Role of Leaf Lipids in Thyme Plant Response to Drought Stress

    Directory of Open Access Journals (Sweden)

    Parviz Moradi

    2017-09-01

    Full Text Available Thymus is one of the best known genera within the Labiatae (Lamiaceae family, with more than 200 species and many medicinal and culinary uses. The effects of prolonged drought on lipid profile were investigated in tolerant and sensitive thyme plants (Thymus serpyllum L. and Thymus vulgaris L., respectively. Non-targeted non-polar metabolite profiling was carried out using Fourier transform ion cyclotron resonance (FT-ICR mass spectrometry with one-month-old plants exposed to drought stress, and their morpho-physiological parameters were also evaluated. Tolerant and sensitive plants exhibited clearly different responses at a physiological level. In addition, different trends for a number of non-polar metabolites were observed when comparing stressed and control samples, for both sensitive and tolerant plants. Sensitive plants showed the highest decrease (55% in main lipid components such as galactolipids and phospholipids. In tolerant plants, the level of lipids involved in signaling increased, while intensities of those induced by stress (e.g., oxylipins dramatically decreased (50–60%, in particular with respect to metabolites with m/z values of 519.3331, 521.3488, and 581.3709. Partial least square discriminant analysis separated all the samples into four groups: tolerant watered, tolerant stressed, sensitive watered and sensitive stressed. The combination of lipid profiling and physiological parameters represented a promising tool for investigating the mechanisms of plant response to drought stress at non-polar metabolome level.

  12. Regulation of Lipid and Glucose Metabolism by Phosphatidylcholine Transfer Protein

    Science.gov (United States)

    Kang, Hye Won; Wei, Jie; Cohen, David E.

    2010-01-01

    Phosphatidylcholine transfer protein (PC-TP, a.k.a. StARD2) binds phosphatidylcholines and catalyzes their intermembrane transfer and exchange in vitro. The structure of PC-TP comprises a hydrophobic pocket and a well-defined head-group binding site, and its gene expression is regulated by peroxisome proliferator activated receptor α. Recent studies have revealed key regulatory roles for PC-TP in lipid and glucose metabolism. Notably, Pctp−/− mice are sensitized to insulin action and exhibit more efficient brown fat-mediated thermogenesis. PC-TP appears to limit access of fatty acids to mitochondria by stimulating the activity of thioesterase superfamily member 2, a newly characterized long-chain fatty acyl-CoA thioesterase. Because PC-TP discriminates among phosphatidylcholines within lipid bilayers, it may function as a sensor that links metabolic regulation to membrane composition. PMID:20338778

  13. Cholesterol Protects the Oxidized Lipid Bilayer from Water Injury

    DEFF Research Database (Denmark)

    Owen, Michael C; Kulig, Waldemar; Rog, Tomasz

    2018-01-01

    In an effort to delineate how cholesterol protects membrane structure under oxidative stress conditions, we monitored the changes to the structure of lipid bilayers comprising 30 mol% cholesterol and an increasing concentration of Class B oxidized 1-palmitoyl-2-oleoylphosphatidylcholine (POPC...... in a characteristic reduction in bilayer thickness and increase in area per lipid, thereby increasing the exposure of the membrane hydrophobic region to water. However, cholesterol was observed to help reduce water injury by moving into the bilayer core and forming more hydrogen bonds with the oxPLs. Cholesterol also...... resists altering its tilt angle, helping to maintain membrane integrity. Water that enters the 1-nm-thick core region remains part of the bulk water on either side of the bilayer, with relatively few water molecules able to traverse through the bilayer. In cholesterol-rich membranes, the bilayer does...

  14. Nonalcoholic Fatty Liver Disease: Focus on Lipoprotein and Lipid Deregulation

    Directory of Open Access Journals (Sweden)

    Klementina Fon Tacer

    2011-01-01

    Full Text Available Obesity with associated comorbidities is currently a worldwide epidemic and among the most challenging health conditions in the 21st century. A major metabolic consequence of obesity is insulin resistance which underlies the pathogenesis of the metabolic syndrome. Nonalcoholic fatty liver disease (NAFLD is the hepatic manifestation of obesity and metabolic syndrome. It comprises a disease spectrum ranging from simple steatosis (fatty liver, through nonalcoholic steatohepatitis (NASH to fibrosis, and ultimately liver cirrhosis. Abnormality in lipid and lipoprotein metabolism accompanied by chronic inflammation is the central pathway for the development of metabolic syndrome-related diseases, such as atherosclerosis, cardiovascular disease (CVD, and NAFLD. This paper focuses on pathogenic aspect of lipid and lipoprotein metabolism in NAFLD and the relevant mouse models of this complex multifactorial disease.

  15. Spin exchange in polarized deuterium

    International Nuclear Information System (INIS)

    Przewoski, B. von; Meyer, H.O.; Balewski, J.; Doskow, J.; Ibald, R.; Pollock, R.E.; Rinckel, T.; Wellinghausen, A.; Whitaker, T.J.; Daehnick, W.W.; Haeberli, W.; Schwartz, B.; Wise, T.; Lorentz, B.; Rathmann, F.; Pancella, P.V.; Saha, Swapan K.; Thoerngren-Engblom, P.

    2003-01-01

    We have measured the vector and tensor polarization of an atomic deuterium target as a function of the target density. The polarized deuterium was produced in an atomic beam source and injected into a storage cell. For this experiment, the atomic beam source was operated without rf transitions, in order to avoid complications from the unknown efficiency of these transitions. In this mode, the atomic beam is vector and tensor polarized and both polarizations can be measured simultaneously. We used a 1.2-cm-diam and 27-cm-long storage cell, which yielded an average target density between 3 and 9x10 11 at/cm 3 . We find that the tensor polarization decreases with increasing target density while the vector polarization remains constant. The data are in quantitative agreement with the calculated effect of spin exchange between deuterium atoms at low field

  16. High energy polarized electron beams

    International Nuclear Information System (INIS)

    Rossmanith, R.

    1987-01-01

    In nearly all high energy electron storage rings the effect of beam polarization by synchrotron radiation has been measured. The buildup time for polarization in storage rings is of the order of 10 6 to 10 7 revolutions; the spins must remain aligned over this time in order to avoid depolarization. Even extremely small spin deviations per revolution can add up and cause depolarization. The injection and the acceleration of polarized electrons in linacs is much easier. Although some improvements are still necessary, reliable polarized electron sources with sufficiently high intensity and polarization are available. With the linac-type machines SLC at Stanford and CEBAF in Virginia, experiments with polarized electrons will be possible

  17. Polarized proton collider at RHIC

    International Nuclear Information System (INIS)

    Alekseev, I.; Allgower, C.; Bai, M.; Batygin, Y.; Bozano, L.; Brown, K.; Bunce, G.; Cameron, P.; Courant, E.; Erin, S.; Escallier, J.; Fischer, W.; Gupta, R.; Hatanaka, K.; Huang, H.; Imai, K.; Ishihara, M.; Jain, A.; Lehrach, A.; Kanavets, V.; Katayama, T.; Kawaguchi, T.; Kelly, E.; Kurita, K.; Lee, S.Y.; Luccio, A.; MacKay, W.W.; Mahler, G.; Makdisi, Y.; Mariam, F.; McGahern, W.; Morgan, G.; Muratore, J.; Okamura, M.; Peggs, S.; Pilat, F.; Ptitsin, V.; Ratner, L.; Roser, T.; Saito, N.; Satoh, H.; Shatunov, Y.; Spinka, H.; Syphers, M.; Tepikian, S.; Tominaka, T.; Tsoupas, N.; Underwood, D.; Vasiliev, A.; Wanderer, P.; Willen, E.; Wu, H.; Yokosawa, A.; Zelenski, A.N.

    2003-01-01

    In addition to heavy ion collisions (RHIC Design Manual, Brookhaven National Laboratory), RHIC will also collide intense beams of polarized protons (I. Alekseev, et al., Design Manual Polarized Proton Collider at RHIC, Brookhaven National Laboratory, 1998, reaching transverse energies where the protons scatter as beams of polarized quarks and gluons. The study of high energy polarized protons beams has been a long term part of the program at BNL with the development of polarized beams in the Booster and AGS rings for fixed target experiments. We have extended this capability to the RHIC machine. In this paper we describe the design and methods for achieving collisions of both longitudinal and transverse polarized protons in RHIC at energies up to √s=500 GeV

  18. Role of lipids for the reproductive success of the Arctic copepod Calanus glacialis

    Science.gov (United States)

    Hatlebakk, M. K.; Graeve, M.; Niehoff, B.; Johnsen, G.; Søreide, J.

    2016-02-01

    Extensive energy storage is common among polar animals, and a range of reproductive strategies have evolved from pure capital breeders, relying on stored energy only, to 100% income breeders where freshly ingested food fuel reproduction. The Arctic calanoid copepod Calanus glacialis is primarily a grazer that accumulates large lipid stores during spring and summer. The breeding strategy to this relatively large and lipid-rich copepod is somewhere on the continuum from pure capital to 100% income breeder. To investigate the importance of stored lipids versus freshly ingested food for the reproductive success of this key copepod we conducted a combined laboratory and field study on a high-Arctic population of C. glacialis in Svalbard from January to May. Total lipids, lipid composition, gonad maturation, egg production and egg hatching success were carefully followed for starved and algal fed females in the laboratory and for females in situ. Lipid stores decreased significantly over time even when food was available, both in laboratory and in field, suggesting that the females largely depended on stored resources for reproduction no matter of the food availability. Lipid reduction was most rapid during gonad maturation prior to first egg production. Almost all fed females spawned compared to only half of the starved ones, and number of eggs and the egg hatching success were significantly improved for fed females. When food was scarce, females produced fewer but more lipid-rich eggs as opposed to more eggs with less lipids when food was abundant - a strategy not previously described for C. glacialis. The fatty acid composition appeared to be more important than the total lipid content for ensuring high egg hatching success, and the polyunsaturated fatty acids 20:5(n-3) and 22:6(n-3), as well as the saturated fatty acids 16:0 and 18:0 seemed to be particularly important. We conclude that C. glacialis is capable of capital breeding, but primarily rely on fresh food for

  19. [STUDY OF LIPIDS SEED'S OIL OF VITEX AGNUS CASTUS GROWING IN GEORGIA].

    Science.gov (United States)

    Kikalishvili, B; Zurabashvili, D; Sulakvelidze, Ts; Malania, M; Turabelidze, D

    2016-07-01

    There was established the lipid composition of the seeds of Vitex agnus castus L. by the qualitative and quantitative methods of analyses. There were received neutral lipids from the seeds by extraction with hexane in the yield 10%, counted on dry material. For the divide of neutral lipids there was used silica gel plates LS 5/40 in the systems of solvents: 1. petroleum ether-diethylether-acidum aceticum (85:14:1), 2. hexane-diethylether (1:1). After obtaining neutral lipids from the residual plant shrot pollar lipids was extracted with the mixture of chloroform-methanol (2:1) and was divided on silica gel plates LS 5/40, mobile phase: 1. chloroform-methanol-25% ammonium hydrate 2. chloroform-methanol icy acetic acid-water (170:25:25:6). In the sum of polar lipids qualitatively were established phospholipids: lisophosphatidylcholine, phosphatidylinosit, phospatidylethanolamine and N-acylphosphatidylethanolamine, in neutral lipids, hydrocarbons, triglycerids, free fatty acids and sterines. By the method of high performance liquid chromatography analyses there were identified following free fatty acids: lauric, myristic, palmitic, stearic, linolic, linolenic, arachidic and begenic, unsaturated oleic and polyunsaturated linolic and linolenic acids. obtained oil with unique composition from the seeds of Vitex agnus-castus indicates to its high biological activity and importance for usage in medicine.

  20. A novel endogenous betaretrovirus group characterized from polar bears (Ursus maritimus) and giant pandas (Ailuropoda melanoleuca)

    OpenAIRE

    Mayer, Jens; Tsangaras, Kyriakos; Heeger, Felix; Ávila-Arcos, Maria; Stenglein, Mark D.; Chen, Wei; Sun, Wei; Mazzoni, Camila; Osterrieder, Nikolaus; Greenwood, Alex D.

    2013-01-01

    Transcriptome analysis of polar bears (Ursus maritimus) yielded sequences with highest similarity to the human endogenous retrovirus group HERV-K(HML-2). Further analysis of the polar bear draft genome identified an endogenous betaretrovirus group comprising 26 proviral copies and 231 solo LTRs. Molecular dating indicates the group originated before the divergence of bears from a common ancestor but is not present in all carnivores. Closely related sequences were identified in the giant panda...

  1. Linear polarization of BY Draconis

    International Nuclear Information System (INIS)

    Koch, R.H.; Pfeiffer, R.J.

    1976-01-01

    Linear polarization measurements are reported in four bandpasses for the flare star BY Dra. The red polarization is intrinsically variable at a confidence level greater than 99 percent. On a time scale of many months, the variability is not phase-locked to either a rotational or a Keplerian ephemeris. The observations of the three other bandpasses are useful principally to indicate a polarization spectrum rising toward shorter wavelengths

  2. Polarity in Mammalian Epithelial Morphogenesis

    OpenAIRE

    Roignot, Julie; Peng, Xiao; Mostov, Keith

    2013-01-01

    Cell polarity is fundamental for the architecture and function of epithelial tissues. Epithelial polarization requires the intervention of several fundamental cell processes, whose integration in space and time is only starting to be elucidated. To understand what governs the building of epithelial tissues during development, it is essential to consider the polarization process in the context of the whole tissue. To this end, the development of three-dimensional organotypic cell culture model...

  3. The sensitivity of income polarization

    DEFF Research Database (Denmark)

    Hussain, Azhar

    2009-01-01

    This study looks at polarization and its components' sensitivity to assumptions about equivalence scales, income definition, ethical income distribution parameters, and the income accounting period. A representative sample of Danish individual incomes from 1984 to 2002 is utilised. Results show....... Increasing the accounting period confirms the reduction in inequality found for shorter periods, but polarization is virtually unchanged, because income group identification increases. Applying different equivalence scales does not change polarization ranking for different years, but identification ranks...

  4. Polarized Electrons for Linear Colliders

    International Nuclear Information System (INIS)

    Clendenin, J.

    2004-01-01

    Future electron-positron linear colliders require a highly polarized electron beam with a pulse structure that depends primarily on whether the acceleration utilizes warm or superconducting rf structures. The International Linear Collider (ILC) will use cold structures for the main linac. It is shown that a dc-biased polarized photoelectron source such as successfully used for the SLC can meet the charge requirements for the ILC micropulse with a polarization approaching 90%

  5. Modeling growth, lipid accumulation and lipid turnover in submerged batch cultures of Umbelopsis isabellina

    NARCIS (Netherlands)

    Meeuwse, P.; Akbari, P.; Tramper, J.; Rinzema, A.

    2012-01-01

    The production of lipids by oleaginous yeast and fungi becomes more important because these lipids can be used for biodiesel production. To understand the process of lipid production better, we developed a model for growth, lipid production and lipid turnover in submerged batch fermentation. This

  6. Lipid nanoparticle interactions and assemblies

    Science.gov (United States)

    Preiss, Matthew Ryan

    Novel liposome-nanoparticle assemblies (LNAs) provide a biologically inspired route for designing multifunctional bionanotheranostics. LNAs combine the benefits of lipids and liposomes to encapsulate, transport, and protect hydrophilic and hydrophobic therapeutics with functional nanoparticles. Functional nanoparticles endow LNAs with additional capabilities, including the ability to target diseases, triggered drug release, controlled therapeutic output, and diagnostic capabilities to produce a drug delivery system that can effectively and efficiently deliver therapeutics while reducing side effects. Not only could LNAs make existing drugs better, they could also provide an avenue to allow once promising non-approved drugs (rejected due to harmful side effects, inadequate pharmacokinetics, and poor efficacy) to be safely used through targeted and controlled delivery directly to the diseased site. LNAs have the potential to be stimuli responsive, delivering drugs on command by external (ultrasound, RF heating, etc.) or internal (pH, blood sugar, heart rate, etc.) stimuli. Individually, lipids and nanoparticles have been clinically approved for therapy, such as Doxil (a liposomal doxorubicin for cancer treatment), and diagnosis, such as Feridex (an iron oxide nanoparticle an MRI contrast enhancement agent for liver tumors). In order to engineer these multifunctional LNAs for theranostic applications, the interactions between nanoparticles and lipids must be better understood. This research sought to explore the formation, design, structures, characteristics, and functions of LNAs. To achieve this goal, different types of LNAs were formed, specifically magnetoliposomes, bilayer decorated LNAs (DLNAs), and lipid-coated magnetic nanoparticles (LMNPs). A fluorescent probe was embedded in the lipid bilayer of magnetoliposomes allowing the local temperature and membrane fluidity to be observed. When subjected to an electromagnetic field that heated the encapsulated iron

  7. Guided wave propagation and scattering in pipeworks comprising elbows: Theoretical and experimental results

    International Nuclear Information System (INIS)

    Bakkali, M El; Lhémery, A; Baronian, V; Chapuis, B

    2015-01-01

    Elastic guided waves (GW) are used to inspect pipeworks in various industries. Modelling tools for simulating GW inspection are necessary to understand complex scattering phenomena occurring at specific features (welds, elbows, junctions...). In pipeworks, straight pipes coexist with elbows. GW propagation in the former cases is well-known, but is less documented in the latter. Their scattering at junction of straight and curved pipes constitutes a complex phenomenon. When a curved part is joined to two straight parts, these phenomena couple and give rise to even more complex wave structures. In a previous work, the SemiAnalytic Finite Element method extended to curvilinear coordinates was used to handle GW propagation in elbows, combined with a mode matching method to predict their scattering at the junction with a straight pipe. Here, a pipework comprising an arbitrary number of elbows of finite length and of different curvature linking straight pipes is considered. A modal scattering matrix is built by cascading local scattering and propagation matrices. The overall formulation only requires meshing the pipe section to compute both the modal solutions and the integrals resulting from the mode-matching method for computing local scattering matrices. Numerical predictions using this approach are studied and compared to experiments

  8. Stability Assessment of a System Comprising a Single Machine and Inverter with Scalable Ratings

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Brian B [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Lin, Yashen [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Gevorgian, Vahan [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Purba, Victor [University of Minnesota; Dhople, Sairaj [University of Minnesota

    2017-09-28

    From the inception of power systems, synchronous machines have acted as the foundation of large-scale electrical infrastructures and their physical properties have formed the cornerstone of system operations. However, power electronics interfaces are playing a growing role as they are the primary interface for several types of renewable energy sources and storage technologies. As the role of power electronics in systems continues to grow, it is crucial to investigate the properties of bulk power systems in low inertia settings. In this paper, we assess the properties of coupled machine-inverter systems by studying an elementary system comprised of a synchronous generator, three-phase inverter, and a load. Furthermore, the inverter model is formulated such that its power rating can be scaled continuously across power levels while preserving its closed-loop response. Accordingly, the properties of the machine-inverter system can be assessed for varying ratios of machine-to-inverter power ratings and, hence, differing levels of inertia. After linearizing the model and assessing its eigenvalues, we show that system stability is highly dependent on the interaction between the inverter current controller and machine exciter, thus uncovering a key concern with mixed machine-inverter systems and motivating the need for next-generation grid-stabilizing inverter controls.

  9. Composite materials comprising two jonal functions and methods for making the same

    Science.gov (United States)

    Fareed, Ali Syed; Garnier, John Edward; Schiroky, Gerhard Hans; Kennedy, Christopher Robin; Sonuparlak, Birol

    2001-01-01

    The present invention generally relates to mechanisms for preventing undesirable oxidation (i.e., oxidation protection mechanisms) in composite bodies. The oxidation protection mechanisms include getterer materials which are added to the composite body which gather or scavenge undesirable oxidants which may enter the composite body. The getterer materials may be placed into at least a portion of the composite body such that any undesirable oxidant approaching, for example, a fiber reinforcement, would be scavenged by (e.g., reacted with) the getterer. The getterer materials) may form at least one compound which acts as a passivation layer, and/or is able to move by bulk transport (e.g., by viscous flow as a glassy material) to a crack, and sealing the crack, thereby further enhancing the oxidation protection of the composite body. One or more ceramic filler materials which serve as reinforcements may have a plurality of super-imposed coatings thereon, at least one of which coatings may function as or contain an oxidation protection mechanism. Specifically, a coating comprising boron nitride which has been engineered or modified to contain some silicon exhibits improved corrosion resistance, specifically to oxygen and moisture. The coated materials may be useful as reinforcing materials in high performance composites to provide improved mechanical properties such as fracture toughness. The present invention also relates to improved composites which incorporate these materials, and to their methods of manufacture.

  10. Strain gauge sensors comprised of carbon nanotube yarn: parametric numerical analysis of their piezoresistive response

    International Nuclear Information System (INIS)

    Abot, Jandro L; Kiyono, César Y; Thomas, Gilles P; Silva, Emílio C N

    2015-01-01

    Carbon nanotube (CNT) yarns are micron-size fibers that contain thousands of intertwined CNTs in their cross sections and exhibit piezoresistance characteristics that can be tapped for sensing purposes. Sensor yarns can be integrated into polymeric and composite materials to measure strain through resistance measurements without adding weight or altering the integrity of the host material. This paper includes the details of novel strain gauge sensor configurations comprised of CNT yarn, the numerical modeling of their piezoresistive response, and the parametric analysis schemes that determines the highest sensor sensitivity to mechanical loading. The effect of several sensor configuration parameters are discussed including the inclination and separation of the CNT yarns within the sensor, the mechanical properties of the CNT yarn, the direction and magnitude of the applied mechanical load, and the dimensions and shape of the sensor. The sensor configurations that yield the highest sensitivity are presented and discussed in terms of the mechanical and electrical properties of the CNT yarn. It is shown that strain gauge sensors consisting of CNT yarn are sensitive enough to measure strain, and could exhibit even higher gauge factors than those of metallic foil strain gauges. (paper)

  11. Implementation of a documentation model comprising nursing terminologies--theoretical and methodological issues.

    Science.gov (United States)

    von Krogh, Gunn; Nåden, Dagfinn

    2008-04-01

    To describe and discuss theoretical and methodological issues of implementation of a nursing services documentation model comprising NANDA nursing diagnoses, Nursing Intervention Classification and Nursing Outcome Classification terminologies. The model is developed for electronic patient record and was implemented in a psychiatric hospital on an organizational level and on five test wards in 2001-2005. The theory of Rogers guided the process of innovation, whereas the implementation procedure of McCloskey and Bulecheck combined with adult learning principals guided the test site implementation. The test wards managed in different degrees to adopt the model. Two wards succeeded fully, including a ward with high percentage of staff with interdisciplinary background. Better planning regarding the impact of the organization's innovative aptitude, the innovation strategies and the use of differentiated methods regarding the clinician's individual premises for learning nursing terminologies might have enhanced the adoption to the model. To better understand the nature of barriers and the importance of careful planning regarding the implementation of electronic patient record elements in nursing care services, focusing on nursing terminologies. Further to indicate how a theory and specific procedure can be used to guide the process of implementation throughout the different levels of management.

  12. Structural analysis and taste evaluation of γ-glutamyl peptides comprising sulfur-containing amino acids.

    Science.gov (United States)

    Amino, Yusuke; Wakabayashi, Hidehiko; Akashi, Satoko; Ishiwatari, Yutaka

    2018-03-01

    The structures, flavor-modifying effects, and CaSR activities of γ-glutamyl peptides comprising sulfur-containing amino acids were investigated. The chemical structures, including the linkage mode of the N-terminal glutamic acid, of γ-L-glutamyl-S-(2-propenyl)-L-cysteine (γ-L-glutamyl-S-allyl-L-cysteine) and its sulfoxide isolated from garlic were established by comparing their NMR spectra with those of authentic peptides prepared using chemical methods. Mass spectrometric analysis also enabled determination of the linkage modes in the glutamyl dipeptides by their characteristic fragmentation. In sensory evaluation, these peptides exhibited flavor-modifying effects (continuity) in umami solutions less pronounced but similar to that of glutathione. Furthermore, the peptides exhibited intrinsic flavor due to the sulfur-containing structure, which may be partially responsible for their flavor-modifying effects. In CaSR assays, γ-L-glutamyl-S-methyl-L-cysteinylglycine was most active, which indicates that the presence of a medium-sized aliphatic substituent at the second amino acid residue in γ-glutamyl peptides enhances CaSR activity.

  13. High-performance organic light-emitting diodes comprising ultrastable glass layers

    Science.gov (United States)

    Rodríguez-Viejo, Javier

    2018-01-01

    Organic light-emitting diodes (OLEDs) are one of the key solid-state light sources for various applications including small and large displays, automotive lighting, solid-state lighting, and signage. For any given commercial application, OLEDs need to perform at their best, which is judged by their device efficiency and operational stability. We present OLEDs that comprise functional layers fabricated as ultrastable glasses, which represent the thermodynamically most favorable and, thus, stable molecular conformation achievable nowadays in disordered solids. For both external quantum efficiencies and LT70 lifetimes, OLEDs with four different phosphorescent emitters show >15% enhancements over their respective reference devices. The only difference to the latter is the growth condition used for ultrastable glass layers that is optimal at about 85% of the materials’ glass transition temperature. These improvements are achieved through neither material refinements nor device architecture optimization, suggesting a general applicability of this concept to maximize the OLED performance, no matter which specific materials are used. PMID:29806029

  14. Novel Metabolic Attributes of the Genus Cyanothece, Comprising a Group of Unicellular Nitrogen-Fixing Cyanobacteria

    Science.gov (United States)

    Bandyopadhyay, Anindita; Elvitigala, Thanura; Welsh, Eric; Stöckel, Jana; Liberton, Michelle; Min, Hongtao; Sherman, Louis A.; Pakrasi, Himadri B.

    2011-01-01

    ABSTRACT The genus Cyanothece comprises unicellular cyanobacteria that are morphologically diverse and ecologically versatile. Studies over the last decade have established members of this genus to be important components of the marine ecosystem, contributing significantly to the nitrogen and carbon cycle. System-level studies of Cyanothece sp. ATCC 51142, a prototypic member of this group, revealed many interesting metabolic attributes. To identify the metabolic traits that define this class of cyanobacteria, five additional Cyanothece strains were sequenced to completion. The presence of a large, contiguous nitrogenase gene cluster and the ability to carry out aerobic nitrogen fixation distinguish Cyanothece as a genus of unicellular, aerobic nitrogen-fixing cyanobacteria. Cyanothece cells can create an anoxic intracellular environment at night, allowing oxygen-sensitive processes to take place in these oxygenic organisms. Large carbohydrate reserves accumulate in the cells during the day, ensuring sufficient energy for the processes that require the anoxic phase of the cells. Our study indicates that this genus maintains a plastic genome, incorporating new metabolic capabilities while simultaneously retaining archaic metabolic traits, a unique combination which provides the flexibility to adapt to various ecological and environmental conditions. Rearrangement of the nitrogenase cluster in Cyanothece sp. strain 7425 and the concomitant loss of its aerobic nitrogen-fixing ability suggest that a similar mechanism might have been at play in cyanobacterial strains that eventually lost their nitrogen-fixing ability. PMID:21972240

  15. Solvent exchange-induced in situ forming gel comprising ethyl cellulose-antimicrobial drugs.

    Science.gov (United States)

    Phaechamud, Thawatchai; Mahadlek, Jongjan

    2015-10-15

    Solvent-exchanged in situ forming gel is a drug delivery system which is in sol form before administration. When it contacts with the body fluid, then the water miscible organic solvent dissipates and water penetrates into the system, leading the polymer precipitation as in situ gel at the site of injection. The aim of this research was to study the parameters affecting the gel properties, drug release and antimicrobial activities of the in situ forming gels prepared from ethyl cellulose (EC) dissolved in N-methyl pyrrolidone (NMP) to deliver the antimicrobial agents (doxycycline hyclate, metronidazole and benzyl peroxide) for periodontitis treatment. The gel appearance, pH, viscosity, rheology, syringeability, gel formation, rate of water diffusion into the gels, in vitro degradation, drug release behavior and antimicrobial activities against Staphylococcus aureus, Escherichia coli, Candida albicans, Streptococcus mutans and Porphyrommonas gingivalis were determined. Increasing the amount of EC increased the viscosity of system while still exhibiting Newtonian flow and increased the work of syringeability whereas decreased the releasing of drug. The system transformed into the rigid gel formation after being injected into the simulated gingival crevicular fluid. The developed systems containing 5% w/w antimicrobial agent showed the antimicrobial activities against all test bacteria. Thus the developed solvent exchange-induced in situ forming gels comprising EC-antimicrobial drugs exhibited potential use for periodontitis treatment. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Characterization of the proteins comprising the integral matrix of Strongylocentrotus purpuratus embryonic spicules

    Science.gov (United States)

    Killian, C. E.; Wilt, F. H.

    1996-01-01

    In the present study, we enumerate and characterize the proteins that comprise the integral spicule matrix of the Strongylocentrotus purpuratus embryo. Two-dimensional gel electrophoresis of [35S]methionine radiolabeled spicule matrix proteins reveals that there are 12 strongly radiolabeled spicule matrix proteins and approximately three dozen less strongly radiolabeled spicule matrix proteins. The majority of the proteins have acidic isoelectric points; however, there are several spicule matrix proteins that have more alkaline isoelectric points. Western blotting analysis indicates that SM50 is the spicule matrix protein with the most alkaline isoelectric point. In addition, two distinct SM30 proteins are identified in embryonic spicules, and they have apparent molecular masses of approximately 43 and 46 kDa. Comparisons between embryonic spicule matrix proteins and adult spine integral matrix proteins suggest that the embryonic 43-kDa SM30 protein is an embryonic isoform of SM30. An adult 49-kDa spine matrix protein is also identified as a possible adult isoform of SM30. Analysis of the SM30 amino acid sequences indicates that a portion of SM30 proteins is very similar to the carbohydrate recognition domain of C-type lectin proteins.

  17. Saccharification of sunflower stalks using lignocellulases from a fungal consortium comprising Pholiota adiposa and Armillaria gemina.

    Science.gov (United States)

    Ramachandran, Priyadharshini; Kim, Tae-Su; Dhiman, Saurabh Sudha; Li, Jinglin; Park, Ji-Hyun; Choi, Joon-Ho; Kim, Jae Young; Kim, Dongwook; Lee, Jung-Kul

    2015-09-01

    Lignocellulases from Armillaria gemina and Pholiota adiposa are efficient in hydrolyzing aspen and poplar biomass, respectively. In the present study, lignocellulosic enzymes obtained from a fungal consortium comprising P. adiposa and A. gemina were used for the saccharification of sunflower stalks. Sunflower stalks were thermochemically pretreated using 2 % NaOH at 50 °C for 24 h. The saccharification process parameters including substrate concentration, enzyme loading, pH, and temperature were optimized using response surface methodology to improve the saccharification yield. The highest enzymatic hydrolysis (84.3 %) was obtained using the following conditions: enzyme loading 10 FPU/g-substrate, substrate 5.5 %, temperature 50 °C, and pH 4.5. The hydrolysis yield obtained using the enzymes from the fungal consortium was equivalent to that obtained using a mixture of commercial enzymes Celluclast and Novozyme β-glucosidase. Addition of up to 500 ppm of heavy metal ions (As, Cu, Fe, Mn, Ni, Pb, and Zn) during saccharification did not significantly affect the saccharification yield. Thus, the biomass grown for phytoremediation of heavy metals can be used for the production of reducing sugars followed by ethanol fermentation.

  18. A polarized alkali ion source

    International Nuclear Information System (INIS)

    Boettger, R.; Tungate, G.; Bauer, B.; Egelhof, P.; Moebius, K.H.; Steffens, E.

    1978-01-01

    The beam foil technique has been applied to detect nuclear vector polarization of a 10 keV 23 Na + beam. The result was about 70% of the atomic beam polarization thus limiting the depolarization by the surface ionizer to at most 30%. In a Coulomb excitation experiment with a tensor polarized 42 MeV 23 Na 7+ beam an effect of 0.011 +- 0.003 was measured yielding a value of t 20 approx. 0.04 for the beam polarization. The depolarization during the acceleration process can be estimated to be about 0.8. (orig.) [de

  19. Polarization preservation in the AGS

    International Nuclear Information System (INIS)

    Ratner, L.G.

    1983-01-01

    The successful operation of a high energy polarized beam at the Argonne Zero Gradient Synchrotron (ZGS) with the concommitant development of depolarizing resonance correction techniques has led to the present project of commissioning such a beam at the Brookhaven Alternating Gradient Synchrotron (AGS). A description of the project was presented at the 1981 National Accelerator Conference. I would like to now present a more detailed description of how we plan to preserve the polarization during acceleration, and to present our game plan for tuning through some 50 resonances and reaching our goal of a 26 GeV polarized proton beam with greater than 60% polarization

  20. Polarization-preserving holey fibers

    DEFF Research Database (Denmark)

    Broeng, Jes; Mogilevtsev, Dmitri; Libori, Stig E. Barkou

    2001-01-01

    In this work we suggest and discuss a microstructure of air capillaries with elliptical cross-section in a tread of glass that gives opportunity for Creation of polarization-preserving fiber with very small beat length between the fundamental modes of different polarization......In this work we suggest and discuss a microstructure of air capillaries with elliptical cross-section in a tread of glass that gives opportunity for Creation of polarization-preserving fiber with very small beat length between the fundamental modes of different polarization...