WorldWideScience

Sample records for assembly lipid capacity

  1. Apolipoprotein B-containing lipoprotein particle assembly: Lipid capacity of the nascent lipoprotein particle

    Energy Technology Data Exchange (ETDEWEB)

    Manchekar, Medha; Forte, Trudy M.; Datta, Geeta; Richardson, Paul E.; Segrest, Jere P.; Dashti, Nassrin

    2003-12-01

    '' without a structural requirement for MTP; (2) amino acids between 931 to 1000 of apoB-100 are critical for the formation of a nascent lipoprotein particle, and (3) the ''lipid pocket'' created by the first 1000 amino acid residues of apoB-100 is PL-rich, suggesting a small bilayer type organization and has a maximum capacity on the order of 70 molecules of lipid. This model is supported by the allatom molecular model of the {beta}{alpha}{sub 1} lipid pocket presented in the accompanying paper.

  2. 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

  3. Polymorphism of lipid self-assembly systems

    International Nuclear Information System (INIS)

    Takahashi, Hiroshi

    2002-01-01

    When lipid molecules are dispersed into an aqueous medium, various self-organized structures are formed, depending on conditions (temperature, concentration, etc), in consequence of the amphipathic nature of the molecules. In addition, lipid self-assembly systems exhibit polymorphic phase transition behavior. Since lipids are one of main components of biomembranes, studies on the structure and thermodynamic properties of lipid self-assembly systems are fundamentally important for the consideration of the stability of biomembranes. (author)

  4. Self-assembled tethered bimolecular lipid membranes.

    Science.gov (United States)

    Sinner, Eva-Kathrin; Ritz, Sandra; Naumann, Renate; Schiller, Stefan; Knoll, Wolfgang

    2009-01-01

    This chapter describes some of the strategies developed in our group for designing, constructing and structurally and functionally characterizing tethered bimolecular lipid membranes (tBLM). We introduce this platform as a novel model membrane system that complements the existing ones, for example, Langmuir monolayers, vesicular liposomal dispersions and bimolecular ("black") lipid membranes. Moreover, it offers the additional advantage of allowing for studies of the influence of membrane structure and order on the function of integral proteins, for example, on how the composition and organization of lipids in a mixed membrane influence the ion translocation activity of integral channel proteins. The first strategy that we introduce concerns the preparation of tethered monolayers by the self-assembly of telechelics. Their molecular architecture with a headgroup, a spacer unit (the "tether") and the amphiphile that mimics the lipid molecule allows them to bind specifically to the solid support thus forming the proximal layer of the final architecture. After fusion of vesicles that could contain reconstituted proteins from a liposomal dispersion in contact to this monolayer the tethered bimolecular lipid membrane is obtained. This can then be characterized by a broad range of surface analytical techniques, including surface plasmon spectroscopies, the quartz crystal microbalance, fluorescence and IR spectroscopies, and electrochemical techniques, to mention a few. It is shown that this concept allows for the construction of tethered lipid bilayers with outstanding electrical properties including resistivities in excess of 10 MOmega cm2. A modified strategy uses the assembly of peptides as spacers that couple covalently via their engineered sulfhydryl or lipoic acid groups at the N-terminus to the employed gold substrate, while their C-terminus is being activated afterward for the coupling of, for example, dimyristoylphosphatidylethanol amine (DMPE) lipid molecules

  5. Lipid dip-pen nanolithography on self-assembled monolayers

    International Nuclear Information System (INIS)

    Gavutis, Martynas; Navikas, Vytautas; Rakickas, Tomas; Vaitekonis, Šarūnas; Valiokas, Ramūnas

    2016-01-01

    Dip-pen nanolithography (DPN) with lipids as an ink enables functional micro/nanopatterning on different substrates at high process speeds. However, only a few studies have addressed the influence of the physicochemical properties of the surface on the structure and phase behavior of DPN-printed lipid assemblies. Therefore, by combining the scanning probe and optical imaging techniques in this work we have analyzed lipid microdomain formation on the self-assembled monolayers (SAMs) on gold as well-defined model surfaces that displayed hydrophilic (protein-repellent) or hydrophobic (protein-adhesive) characteristics. We have found that on the tri(ethylene glycol)-terminated SAM the lipid ink transfer was fast (∼10 –1 μm 3 s −1 ), quasi-linear and it yielded unstable, sparsely packed lipid microspots. Contrary to this, on the methyl-terminated SAM the lipid transfer was ∼20 times slower, nonlinear, and the obtained stable dots of ∼1 μm in diameter consisted of lipid multilayers. Our comparative analysis indicated that the measured lipid transfer was consistent with the previously reported so-called polymer transfer model (Felts et al 2012, Nanotechnology 23 215301). Further on, by employing the observed distinct contrast in the DPN ink behavior we constructed confined lipid microdomains on pre-patterned SAMs, in which the lipids assembled either into monolayer or multilamellar phases. Such microdomains can be further utilized for lipid membrane mimetics in microarray and lab-on-a-chip device formats. (paper)

  6. Functional self-assembled lipidic systems derived from renewable resources.

    Science.gov (United States)

    Silverman, Julian R; Samateh, Malick; John, George

    2016-01-01

    Self-assembled lipidic amphiphile systems can create a variety of multi-functional soft materials with value-added properties. When employing natural reagents and following biocatalytic syntheses, self-assembling monomers may be inherently designed for degradation, making them potential alternatives to conventional and persistent polymers. By using non-covalent forces, self-assembled amphiphiles can form nanotubes, fibers, and other stimuli responsive architectures prime for further applied research and incorporation into commercial products. By viewing these lipid derivatives under a lens of green principles, there is the hope that in developing a structure-function relationship and functional smart materials that research may remain safe, economic, and efficient.

  7. Prediction of Liquid Specific Heat Capacity of Food Lipids.

    Science.gov (United States)

    Zhu, Xiaoyi; Phinney, David M; Paluri, Sravanti; Heldman, Dennis R

    2018-04-01

    Specific heat capacity (c p ) is a temperature dependent physical property of foods. Lipid-being a macromolecular component of food-provides some fraction of the food's overall heat capacity. Fats/oils are complex chemicals that are generally defined by carbon length and degree of unsaturation. The objective of this investigation was to use advanced specific heat capacity measurement to determine the effect of fatty acid chemical structure on specific heat capacity of food lipids. In this investigation, the specific heat capacity of a series of triacylglycerols were measured to quantify the influence of fatty acid composition on specific heat capacity based on two parameters; the -average carbon number (C) and the average number of double bonds (U). A prediction model for specific heat capacity of food lipids as a function of C, U and temperature (T) has been developed. A multiple linear regression to the three-parameter model (R 2 = 0.87) provided a good fit to the experimental data. The prediction model was evaluated by comparison with previously published specific heat capacity values of vegetable oils. It was found that the model provided a 0.53% error, while three other models from the literature predicted c p values with 0.85% to 1.83% average relative deviation from experimental data. The outcomes from this research confirm that the thermophysical properties of fat present in foods are directly related to the physical chemical properties. The specific heat capacity of food products is widely used in process design. Improvements of current models to predict specific heat capacity of food products will assist in the development of efficient processes and in the control of food quality and safety. Furthermore, the understanding of how changes in chemical structure of macromolecular components of foods effect thermophysical properties may begin to allude to models that are not just empirical, but represent portions of the differences in chemistry. © 2018

  8. Pressure effects on lipids and bio-membrane assemblies

    Directory of Open Access Journals (Sweden)

    Nicholas J. Brooks

    2014-11-01

    Full Text Available Membranes are amongst the most important biological structures; they maintain the fundamental integrity of cells, compartmentalize regions within them and play an active role in a wide range of cellular processes. Pressure can play a key role in probing the structure and dynamics of membrane assemblies, and is also critical to the biology and adaptation of deep-sea organisms. This article presents an overview of the effect of pressure on the mesostructure of lipid membranes, bilayer organization and lipid–protein assemblies. It also summarizes recent developments in high-pressure structural instrumentation suitable for experiments on membranes.

  9. Improved insulin loading in poly(lactic-co-glycolic) acid (PLGA) nanoparticles upon self-assembly with lipids.

    Science.gov (United States)

    García-Díaz, María; Foged, Camilla; Nielsen, Hanne Mørck

    2015-03-30

    Polymeric nanoparticles are widely investigated as drug delivery systems for oral administration. However, the hydrophobic nature of many polymers hampers effective loading of the particles with hydrophilic macromolecules such as insulin. Thus, the aim of this work was to improve the loading of insulin into poly(lactic-co-glycolic) acid (PLGA) nanoparticles by pre-assembly with amphiphilic lipids. Insulin was complexed with soybean phosphatidylcholine or sodium caprate by self-assembly and subsequently loaded into PLGA nanoparticles by using the double emulsion-solvent evaporation technique. The nanoparticles were characterized in terms of size, zeta potential, insulin encapsulation efficiency and loading capacity. Upon pre-assembly with lipids, there was an increased distribution of insulin into the organic phase of the emulsion, eventually resulting in significantly enhanced encapsulation efficiencies (90% as compared to 24% in the absence of lipids). Importantly, the insulin loading capacity was increased up to 20% by using the lipid-insulin complexes. The results further showed that a main fraction of the lipid was incorporated into the nanoparticles and remained associated to the polymer during release studies in buffers, whereas insulin was released in a non-complexed form as a burst of approximately 80% of the loaded insulin. In conclusion, the protein load in PLGA nanoparticles can be significantly increased by employing self-assembled protein-lipid complexes. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. How relevant are assembled equilibrium samples in understanding structure formation during lipid digestion?

    Science.gov (United States)

    Phan, Stephanie; Salentinig, Stefan; Hawley, Adrian; Boyd, Ben J

    2015-10-01

    Lipid-based formulations are gaining interest for use as drug delivery systems for poorly water-soluble drug compounds. During digestion, the lipolysis products self-assemble with endogenous surfactants in the gastrointestinal tract to form colloidal structures, enabling enhanced drug solubilisation. Although earlier studies in the literature focus on assembled equilibrium systems, little is known about structure formation under dynamic lipolysis conditions. The purpose of this study was to investigate the likely colloidal structure formation in the small intestine after the ingestion of lipids, under equilibrium and dynamic conditions. The structural aspects were studied using small angle X-ray scattering and dynamic light scattering, and were found to depend on lipid composition, lipid chain length, prandial state and emulsification. Incorporation of phospholipids and lipolysis products into bile salt micelles resulted in swelling of the structure. At insufficient bile salt concentrations, a co-existing lamellar phase was observed, due to a reduction in the solubilisation capacity for lipolysis products. Emulsification accelerated the rate of lipolysis and structure formation. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Capacity analysis of automatic transport systems in an assembly factory

    NARCIS (Netherlands)

    Zijm, W.H.M.; Lenstra, J.K.; Tijms, H.C.; Volgenant, A.

    1989-01-01

    We describe a case study concerning the capacity analysis of a completely automated transport system in a flexible assembly environment. Basically, the system is modelled as a network of queues, however, due to its complex nature, product-form network theory is not applicable. Instead, we present an

  12. Improved insulin loading in poly (lactic-co-glycolic) acid (PLGA) nanoparticles upon self-assembly with lipids

    DEFF Research Database (Denmark)

    Garcia Diaz, Maria; Foged, Camilla; Nielsen, Hanne Mørck

    2015-01-01

    Polymeric nanoparticles are widely investigated as drug delivery systems for oral administration. However, the hydrophobic nature of many polymers hampers effective loading of the particles with hydrophilic macromolecules such as insulin. Thus, the aim of this work was to improve the loading...... of insulin into poly(lactic-co-glycolic) acid (PLGA) nanoparticles by pre-assembly with amphiphilic lipids. Insulin was complexed with soybean phosphatidylcholine or sodium caprate by self-assembly and subsequently loaded into PLGA nanoparticles by using the double emulsion-solvent evaporation technique...... efficiencies (90% as compared to 24% in the absence of lipids). Importantly, the insulin loading capacity was increased up to 20% by using the lipid–insulin complexes. The results further showed that a main fraction of the lipid was incorporated into the nanoparticles and remained associated to the polymer...

  13. Lenalidomide induces lipid raft assembly to enhance erythropoietin receptor signaling in myelodysplastic syndrome progenitors.

    Science.gov (United States)

    McGraw, Kathy L; Basiorka, Ashley A; Johnson, Joseph O; Clark, Justine; Caceres, Gisela; Padron, Eric; Heaton, Ruth; Ozawa, Yukiyasu; Wei, Sheng; Sokol, Lubomir; List, Alan F

    2014-01-01

    Anemia remains the principal management challenge for patients with lower risk Myelodysplastic Syndromes (MDS). Despite appropriate cytokine production and cellular receptor display, erythropoietin receptor (EpoR) signaling is impaired. We reported that EpoR signaling is dependent upon receptor localization within lipid raft microdomains, and that disruption of raft integrity abolishes signaling capacity. Here, we show that MDS erythroid progenitors display markedly diminished raft assembly and smaller raft aggregates compared to normal controls (p = 0.005, raft number; p = 0.023, raft size). Because lenalidomide triggers raft coalescence in T-lymphocytes promoting immune synapse formation, we assessed effects of lenalidomide on raft assembly in MDS erythroid precursors and UT7 cells. Lenalidomide treatment rapidly induced lipid raft formation accompanied by EpoR recruitment into raft fractions together with STAT5, JAK2, and Lyn kinase. The JAK2 phosphatase, CD45, a key negative regulator of EpoR signaling, was displaced from raft fractions. Lenalidomide treatment prior to Epo stimulation enhanced both JAK2 and STAT5 phosphorylation in UT7 and primary MDS erythroid progenitors, accompanied by increased STAT5 DNA binding in UT7 cells, and increased erythroid colony forming capacity in both UT7 and primary cells. Raft induction was associated with F-actin polymerization, which was blocked by Rho kinase inhibition. These data indicate that deficient raft integrity impairs EpoR signaling, and provides a novel strategy to enhance EpoR signal fidelity in non-del(5q) MDS.

  14. Self-assembly of core-polyethylene glycol-lipid shell (CPLS) nanoparticles and their potential as drug delivery vehicles

    Science.gov (United States)

    Shen, Zhiqiang; Loe, David T.; Awino, Joseph K.; Kröger, Martin; Rouge, Jessica L.; Li, Ying

    2016-08-01

    Herein a new multifunctional formulation, referred to as a core-polyethylene glycol-lipid shell (CPLS) nanoparticle, has been proposed and studied in silico via large scale coarse-grained molecular dynamics simulations. A PEGylated core with surface tethered polyethylene glycol (PEG) chains is used as the starting configuration, where the free ends of the PEG chains are covalently bonded with lipid molecules (lipid heads). A complete lipid bilayer is formed at the surface of the PEGylated particle core upon addition of free lipids, driven by the hydrophobic properties of the lipid tails, leading to the formation of a CPLS nanoparticle. The self-assembly process is found to be sensitive to the grafting density and molecular weight of the tethered PEG chains, as well as the amount of free lipids added. At low grafting densities the assembly of CPLS nanoparticles cannot be accomplished. As demonstrated by simulations, a lipid bud/vesicle can be formed on the surface when an excess amount of free lipids is added at high grafting density. Therefore, the CPLS nanoparticles can only be formed under appropriate conditions of both PEG and free lipids. The CPLS nanoparticle has been recognized to be able to store a large quantity of water molecules, particularly with high molecular weight of PEG chains, indicating its capacity for carrying hydrophilic molecules such as therapeutic biomolecules or imaging agents. Under identical size and surface chemistry conditions of a liposome, it has been observed that the CPLS particle can be more efficiently wrapped by the lipid membrane, indicating its potential for a greater efficiency in delivering its hydrophilic cargo. As a proof-of-concept, the experimental realization of CPLS nanoparticles is explicitly demonstrated in this study. To test the capacity of the CPLS to store small molecule cargo a hydrophilic dye was successfully encapsulated in the particles' water soluble layer. The results of this study show the power and

  15. Modelling phagosomal lipid networks that regulate actin assembly

    Directory of Open Access Journals (Sweden)

    Schwarz Roland

    2008-12-01

    Full Text Available Abstract Background When purified phagosomes are incubated in the presence of actin under appropriate conditions, microfilaments start growing from the membrane in a process that is affected by ATP and the lipid composition of the membrane. Isolated phagosomes are metabolically active organelles that contain enzymes and metabolites necessary for lipid interconversion. Hence, addition of ATP, lipids, and actin to the system alter the steady-state composition of the phagosomal membrane at the same time that the actin nucleation is initiated. Our aim was to model all these processes in parallel. Results We compiled detailed experimental data on the effects of different lipids and ATP on actin nucleation and we investigated experimentally lipid interconversion and ATP metabolism in phagosomes by using suitable radioactive compounds. In a first step, a complex lipid network interconnected by chemical reactions catalyzed by known enzymes was modelled in COPASI (Complex Pathway Simulator. However, several lines of experimental evidence indicated that only the phosphatidylinositol branch of the network was active, an observation that dramatically reduced the number of parameters in the model. The results also indicated that a lipid network-independent ATP-consuming activity should be included in the model. When this activity was introduced, the set of differential equations satisfactorily reproduced the experimental data. On the other hand, a molecular mechanism connecting membrane lipids, ATP, and the actin nucleation process is still missing. We therefore adopted a phenomenological (black-box approach to represent the empirical observations. We proposed that lipids and ATP influence the dynamic interconversion between active and inactive actin nucleation sites. With this simple model, all the experimental data were satisfactorily fitted with a single positive parameter per lipid and ATP. Conclusion By establishing an active 'dialogue' between an

  16. Lipid-bilayer-assisted two-dimensional self-assembly of DNA origami nanostructures

    Science.gov (United States)

    Suzuki, Yuki; Endo, Masayuki; Sugiyama, Hiroshi

    2015-08-01

    Self-assembly is a ubiquitous approach to the design and fabrication of novel supermolecular architectures. Here we report a strategy termed `lipid-bilayer-assisted self-assembly' that is used to assemble DNA origami nanostructures into two-dimensional lattices. DNA origami structures are electrostatically adsorbed onto a mica-supported zwitterionic lipid bilayer in the presence of divalent cations. We demonstrate that the bilayer-adsorbed origami units are mobile on the surface and self-assembled into large micrometre-sized lattices in their lateral dimensions. Using high-speed atomic force microscopy imaging, a variety of dynamic processes involved in the formation of the lattice, such as fusion, reorganization and defect filling, are successfully visualized. The surface modifiability of the assembled lattice is also demonstrated by in situ decoration with streptavidin molecules. Our approach provides a new strategy for preparing versatile scaffolds for nanofabrication and paves the way for organizing functional nanodevices in a micrometer space.

  17. Hepatic trans-Golgi action coordinated by the GTPase ARFRP1 is crucial for lipoprotein lipidation and assembly[S

    Science.gov (United States)

    Hesse, Deike; Radloff, Katrin; Jaschke, Alexander; Lagerpusch, Merit; Chung, Bomee; Tailleux, Anne; Staels, Bart; Schürmann, Annette

    2014-01-01

    The liver is a major organ in whole body lipid metabolism and malfunctioning can lead to various diseases including dyslipidemia, fatty liver disease, and type 2 diabetes. Triglycerides and cholesteryl esters are packed in the liver as very low density lipoproteins (VLDLs). Generation of these lipoproteins is initiated in the endoplasmic reticulum and further maturation likely occurs in the Golgi. ADP-ribosylation factor-related protein 1 (ARFRP1) is a small trans-Golgi-associated guanosine triphosphatase (GTPase) that regulates protein sorting and is required for chylomicron lipidation and assembly in the intestine. Here we show that the hepatocyte-specific deletion of Arfrp1 (Arfrp1liv−/−) results in impaired VLDL lipidation leading to reduced plasma triglyceride levels in the fasted state as well as after inhibition of lipoprotein lipase activity by Triton WR-1339. In addition, the concentration of ApoC3 that comprises 40% of protein mass of secreted VLDLs is markedly reduced in the plasma of Arfrp1liv−/− mice but accumulates in the liver accompanied by elevated triglycerides. Fractionation of Arfrp1liv−/− liver homogenates reveals more ApoB48 and a lower concentration of triglycerides in the Golgi compartments than in the corresponding fractions from control livers. In conclusion, ARFRP1 and the Golgi apparatus play an important role in lipoprotein maturation in the liver by influencing lipidation and assembly of proteins to the lipid particles. PMID:24186947

  18. Lipids in the Assembly of Membrane Proteins and Organization of Protein Supercomplexes: Implications for Lipid-Linked Disorders

    OpenAIRE

    Bogdanov, Mikhail; Mileykovskaya, Eugenia; Dowhan, William

    2008-01-01

    Lipids play important roles in cellular dysfunction leading to disease. Although a major role for phospholipids is in defining the membrane permeability barrier, phospholipids play a central role in a diverse range of cellular processes and therefore are important factors in cellular dysfunction and disease. This review is focused on the role of phospholipids in normal assembly and organization of the membrane proteins, multimeric protein complexes, and higher order supercomplexes. Since lipi...

  19. Effects of High Pressure on Internally Self-Assembled Lipid Nanoparticles

    DEFF Research Database (Denmark)

    Kulkarni, Chandrashekhar V; Yaghmur, Anan; Steinhart, Milos

    2016-01-01

    We present the first report on the effects of hydrostatic pressure on colloidally stabilized lipid nanoparticles enveloping inverse nonlamellar self-assemblies in their interiors. These internal self-assemblies were systematically tuned into bicontinuous cubic (Pn3m and Im3m), micellar cubic (Fd3...... the tolerance of lipid nanoparticles [cubosomes, hexosomes, micellar cubosomes, and emulsified microemulsions (EMEs)] for high pressures, confirming their robustness for various technological applications.......We present the first report on the effects of hydrostatic pressure on colloidally stabilized lipid nanoparticles enveloping inverse nonlamellar self-assemblies in their interiors. These internal self-assemblies were systematically tuned into bicontinuous cubic (Pn3m and Im3m), micellar cubic (Fd3m......), hexagonal (H2), and inverse micellar (L2) phases by regulating the lipid/oil ratio as the hydrostatic pressure was varied from atmospheric pressure to 1200 bar and back to atmospheric pressure. The effects of pressure on these lipid nanoparticles were compared with those on their equilibrium bulk...

  20. DNA mediated assembly of lipid particles and uses therefor

    DEFF Research Database (Denmark)

    2007-01-01

    The present invention relates to detection of target nucleic acids by targetnucleic acid induced liposome assembly. The invention provides oligonucleotides for use in detection and a method of detecting target nucleic acids.Other aspects of the invention are use of the oligonucleotide of the inve...

  1. 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

  2. Lipid self-assembly and lectin-induced reorganization of the plasma membrane.

    Science.gov (United States)

    Sych, Taras; Mély, Yves; Römer, Winfried

    2018-05-26

    The plasma membrane represents an outstanding example of self-organization in biology. It plays a vital role in protecting the integrity of the cell interior and regulates meticulously the import and export of diverse substances. Its major building blocks are proteins and lipids, which self-assemble to a fluid lipid bilayer driven mainly by hydrophobic forces. Even if the plasma membrane appears-globally speaking-homogeneous at physiological temperatures, the existence of specialized nano- to micrometre-sized domains of raft-type character within cellular and synthetic membrane systems has been reported. It is hypothesized that these domains are the origin of a plethora of cellular processes, such as signalling or vesicular trafficking. This review intends to highlight the driving forces of lipid self-assembly into a bilayer membrane and the formation of small, transient domains within the plasma membrane. The mechanisms of self-assembly depend on several factors, such as the lipid composition of the membrane and the geometry of lipids. Moreover, the dynamics and organization of glycosphingolipids into nanometre-sized clusters will be discussed, also in the context of multivalent lectins, which cluster several glycosphingolipid receptor molecules and thus create an asymmetric stress between the two membrane leaflets, leading to tubular plasma membrane invaginations.This article is part of the theme issue 'Self-organization in cell biology'. © 2018 The Author(s).

  3. Structure formation in binary mixtures of lipids and detergents: self-assembly and vesicle division.

    Science.gov (United States)

    Noguchi, Hiroshi

    2013-01-14

    Self-assembly dynamics in binary surfactant mixtures and structure changes of lipid vesicles induced by detergent solution are studied using coarse-grained molecular simulations. Disk-shaped micelles, the bicelles, are stabilized by detergents surrounding the rim of a bilayer disk of lipids. The self-assembled bicelles are considerably smaller than bicelles formed from vesicle rupture, and their size is determined by the concentrations of lipids and detergents and the interactions between the two species. The detergent-adsorption induces spontaneous curvature of the vesicle bilayer and results in vesicle division into two vesicles or vesicle rupture into worm-like micelles. The division occurs mainly via the inverse pathway of the modified stalk model. For large spontaneous curvature of the monolayers of the detergents, a pore is often opened, thereby leading to vesicle division or worm-like micelle formation.

  4. Blooming reduces the antioxidant capacity of dark chocolate in rats without lowering its capacity to improve lipid profiles.

    Science.gov (United States)

    Shadwell, Naomi; Villalobos, Fatima; Kern, Mark; Hong, Mee Young

    2013-05-01

    Dark chocolate contains high levels of antioxidants which are linked to a reduced risk of cardiovascular disease. Chocolate blooming occurs after exposure to high temperatures. Although bloomed chocolate is safe for human consumption, it is not known whether or not the biological function of bloomed chocolate is affected. We hypothesized that bloomed chocolate would reduce the antioxidant potential and lipid-lowering properties of chocolate through altered expression of related genes. Thirty Sprague-Dawley rats were divided into 3 groups and fed either the control (CON), regular dark chocolate (RDC), or bloomed dark chocolate (BDC) diet. After 3 weeks, serum lipid levels and antioxidant capacity were measured. Hepatic expression of key genes was determined by real time polymerase chain reaction (PCR). Sensory characteristics of bloomed versus regular chocolate were assessed in 28 semi-trained panelists. Rats fed RDC exhibited greater serum antioxidant capacities compared to the CON (P chocolate compared to bloomed chocolate (P chocolate, these results suggest that bloomed dark chocolate yields similarly beneficial effects on most blood lipid parameters or biomarkers. However, regular dark chocolate may be more beneficial for the improvement of antioxidant status and modulation of gene expression involved in lipid metabolism and promoted greater sensory ratings. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. Synthesis, self-assembly and lipoplex formulation of two novel cyclic phosphonate lipids

    Directory of Open Access Journals (Sweden)

    JenniferYeh

    2013-05-01

    Full Text Available Background: Synthetic cationic lipids hold much potential as gene packaging and delivery agents for the treatment of inherited and acquired life threatening diseases, such as cancer, AIDS, cardiovascular diseases, and certain autoimmune disorders. Methods: We report the synthesis, self-assembly as characterized by critical micelle concentrations and plasmid DNA gel retardation using two novel cyclic, phosphonate cationic lipids 2a and 2b, which were synthesized by derivatizing two diastereomeric macrocyclic phosphonates 1a and 1b with a 2-carbon hydroxylamine linker, N, N-dimethylethanolamine (3. Results: The production of cyclic phosphonate lipids 2a and 2b in 73% and 60% yields, respectively, was achieved using classical synthetic methods involving nucleophilic substitution at the phosphorus centre. Conclusions: The synthesis, aggregation and DNA binding properties of these novel cyclic phosphonate lipids suggest that they may have utility serving as gene packaging and delivery agents.

  6. Two sides of the coin. Part 1. Lipid and surfactant self-assembly revisited.

    Science.gov (United States)

    Ninham, Barry W; Larsson, Kåre; Lo Nostro, Pierandrea

    2017-04-01

    Hofmeister, specific ion effects, hydration and van der Waals forces at and between interfaces are factors that determine curvature and microstructure in self assembled aggregates of surfactants and lipids; and in microemulsions. Lipid and surfactant head group interactions and between aggregates vary enormously and are highly specific. They act on the hydrophilic side of a bilayer, micelle or other self assembled aggregate. It is only over the last three decades that the origin of Hofmeister effects has become generally understood. Knowledge of their systematics now provides much flexibility in designing nanostructured fluids. The other side of the coin involves equally specific forces. These (opposing) forces work on the hydrophobic side of amphiphilic interfaces. They are due to the interaction of hydrocarbons and other "oils" with hydrophobic tails of surfactants and lipids. The specificity of oleophilic solutes in microemulsions and lipid membranes provides a counterpoint to Hofmeister effects and hydration. Together with global packing constraints these effects determine microstructure. Another factor that has hardly been recognised is the role of dissolved gas. This introduces further, qualitative changes in forces that prescribe microstructure. The systematics of these effects and their interplay are elucidated. Awareness of these competing factors facilitates formulation of self assembled nanostructured fluids. New and predictable geometries that emerge naturally provide insights into a variety of biological phenomena like anaesthetic and pheromone action and transmission of the nervous impulse (see Part 2). Copyright © 2017 Elsevier B.V. All rights reserved.

  7. A study of the enhanced sensitizing capacity of a contact allergen in lipid vesicle formulations

    DEFF Research Database (Denmark)

    Simonsson, Carl; Madsen, Jakob Torp; Graneli, Annette

    2011-01-01

    , an indicator of a compounds sensitizing capacity, increased when RBITC was applied in lipid vesicles as compared to an ethanol:water (Et:W) solution. Micro-scale vesicles showed a slightly higher cell proliferative response compared to nano-scale vesicles. TPM imaging revealed that the vesicle formulations...... improved the skin penetration of RBITC compared to the Et:W solution. A strong fluorescent region in the stratum corneum and upper epidermis implies elevated association of RBITC to these skin layers when formulated in lipid vesicles. In conclusion, the results indicate that there could be an elevated risk...... of sensitization when haptens are delivered in vehicles containing lipid vesicles. Although the size of the vesicles seems to be of minor importance, further studies are needed before a more generalized conclusion can be drawn. It is likely that the enhanced sensitizing capacity is a consequence of the improved...

  8. Dietary manipulation of the sow milk does not influence the lipid absorption capacity of the progeny

    DEFF Research Database (Denmark)

    Lauridsen, Charlotte; Hedemann, Mette Skou; Pierzynowski, Stefan

    2007-01-01

    A control diet without supplemental fat and four diets containing 8% of coconut oil, rapeseed oil, fish oil or sunflower oil were fed to lactating sows in order to investigate the lipid absorption capacity of their progeny in terms of pancreatic enzyme activity, hormonal regulation, and bile salt...

  9. Lipid-bilayer-assisted two-dimensional self-assembly of DNA origami nanostructures

    Science.gov (United States)

    Endo, Masayuki; Sugiyama, Hiroshi

    2015-01-01

    Self-assembly is a ubiquitous approach to the design and fabrication of novel supermolecular architectures. Here we report a strategy termed ‘lipid-bilayer-assisted self-assembly' that is used to assemble DNA origami nanostructures into two-dimensional lattices. DNA origami structures are electrostatically adsorbed onto a mica-supported zwitterionic lipid bilayer in the presence of divalent cations. We demonstrate that the bilayer-adsorbed origami units are mobile on the surface and self-assembled into large micrometre-sized lattices in their lateral dimensions. Using high-speed atomic force microscopy imaging, a variety of dynamic processes involved in the formation of the lattice, such as fusion, reorganization and defect filling, are successfully visualized. The surface modifiability of the assembled lattice is also demonstrated by in situ decoration with streptavidin molecules. Our approach provides a new strategy for preparing versatile scaffolds for nanofabrication and paves the way for organizing functional nanodevices in a micrometer space. PMID:26310995

  10. Model for Assembly Line Re-Balancing Considering Additional Capacity and Outsourcing to Face Demand Fluctuations

    Science.gov (United States)

    Samadhi, TMAA; Sumihartati, Atin

    2016-02-01

    The most critical stage in a garment industry is sewing process, because generally, it consists of a number of operations and a large number of sewing machines for each operation. Therefore, it requires a balancing method that can assign task to work station with balance workloads. Many studies on assembly line balancing assume a new assembly line, but in reality, due to demand fluctuation and demand increased a re-balancing is needed. To cope with those fluctuating demand changes, additional capacity can be carried out by investing in spare sewing machine and paying for sewing service through outsourcing. This study develops an assembly line balancing (ALB) model on existing line to cope with fluctuating demand change. Capacity redesign is decided if the fluctuation demand exceeds the available capacity through a combination of making investment on new machines and outsourcing while considering for minimizing the cost of idle capacity in the future. The objective of the model is to minimize the total cost of the line assembly that consists of operating costs, machine cost, adding capacity cost, losses cost due to idle capacity and outsourcing costs. The model develop is based on an integer programming model. The model is tested for a set of data of one year demand with the existing number of sewing machines of 41 units. The result shows that additional maximum capacity up to 76 units of machine required when there is an increase of 60% of the average demand, at the equal cost parameters..

  11. Effect of the microfiltration process on antioxidant activity and lipid peroxidation protection capacity of blackberry juice

    Directory of Open Access Journals (Sweden)

    Gabriela Azofeifa

    2011-08-01

    Full Text Available Phytochemicals are highly concentrated in berries, especially polyphenols as anthocyanins and ellagitannins. These compounds have been associated with antioxidant capacity, lipid peroxidation protection, anti-inflammatory activity, anti-carcinogenic activity, obesity prevention and others. Blackberries are commonly grown and consumed as juice in Latin-American countries. However, blackberry juice is easily fermented and different industrial techniques are being applied to enable the juice to be stored for longer periods. One important issue required for these techniques is to preserve the health-promoting capacities of blackberries. This study compared the antioxidant activity and the lipid peroxidation protector effect between a fresh blackberry juice (FJ and a microfiltrated blackberry juice (MJ. Chemical analysis of both juices show less polyphenols concentration in the MJ. Despite this difference, values for biological activities, such as protection of lipid peroxidation, was not significantly different between FJ and MJ. These results suggest that the compounds responsible for the antioxidant activity are maintained even after microfiltration and the free radical scavenging capacity of these compounds could protect the initiation of lipid peroxidation. Microfiltration could be used as an industrial technique to produce blackberry juice that maintains biological activities of polyphenols.

  12. 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...

  13. Antioxidant capacity of meagre (Argyrossomus regius fed different lipid content and source, with and without selenium

    Directory of Open Access Journals (Sweden)

    Sthelio Braga Fonseca

    2014-06-01

    Meagre (600 animals were kept in 24 tanks (80 L with constant renovation and aeration and maintained at 20.7 ± 0.7ºC and oxygen 8.8 ± 1.7 mg L-1. Fish were fed twice per day, six days per week, with eight different experimental diets for 60 days. Diets were formulated to have two different oil sources (fish or vegetable blend oils with 45% of linseed, 35% of rapeseed and 20% of soybean oil, two lipid levels (12 and 17% and two selenium supplementation (0 and 1 mg/kg diet. Lipid peroxidation (LPO, glutathione reductase (GR, glutathione peroxidase (GPx, total glutathione (TG and catalase (CAT were analyzed in liver of fish. CAT, GPx and GR activities were not significantly altered in fish fed with diets with different oil sources. However, TG in fish fed with fish oil diet was higher than the levels observed in fish fed with vegetable blend oil. Furthermore, fish fed with fish oil diet showed lower lipid peroxidation when compared with fish fed vegetable blend oil diet (Table 1. Concerning the oil level in diet, it was observed that fish fed with a diet of 17% lipids had a higher level of total glutathione when compared to fish fed with a diet of 12% lipids. On the other hand, the fish fed with a diet with 12% lipids showed lower levels of lipid peroxidation when compared to fish fed with a diet of 17% lipids. Fish fed with diets supplemented with selenium showed a significantly increased activity of GPx when compared with fish fed without selenium. Three-way ANOVA analysis showed that dietary lipid level and the presence of selenium have a significant interaction on the activities of CAT and GR, as well as, levels of TG and LPO. A significant interaction between the source of oil and the presence of selenium on GR activities was observed. Interaction on source and level was observed to CAT. In conclusion, the antioxidant capacity of meagre is influenced by the source of oil, the level of lipids and the presence of selenium in their diet.

  14. Role of Gag and lipids during HIV-1 assembly in CD4 T cells and Macrophages

    Directory of Open Access Journals (Sweden)

    Charlotte eMariani

    2014-06-01

    Full Text Available HIV-1 is an RNA enveloped virus that preferentiallyinfects CD4+ T lymphocytes andalso macrophages. In CD4+ T cells, HIV-1mainly buds from the host cell plasma membrane.The viral Gag polyprotein targets theplasma membrane and is the orchestrator ofthe HIV assembly as its expression is sufficientto promote the formation of virus-likeparticles particles carrying a lipidic envelopederiving from the host cell membrane. Certainlipids are enriched in the viral membraneand are thought to play a key role in theassembly process and the envelop composition.A large body of work performed oninfected CD4+ T cells has provided importantknowledge about the assembly process andthe membrane virus lipid composition. WhileHIV assembly and budding in macrophages isthought to follow the same general Gag-drivenmechanism as in T-lymphocytes, the HIV cyclein macrophage exhibits specific features.In these cells, new virions bud from the limitingmembrane of seemingly intracellular compartments,where they accumulate while remaininginfectious. These structures are now oftenreferred to as Virus Containing Compartments(VCCs. Recent studies suggest that VCCsrepresent intracellularly sequestered regionsof the plasma membrane, but their precisenature remains elusive. The proteomic andlipidomic characterization of virions producedby T cells or macrophages has highlightedthe similarity between their composition andthat of the plasma membrane of producercells, as well as their enrichment in acidiclipids, some components of raft lipids andin tetraspanin-enriched microdomains. Greatchances are that Gag promotes the coalescenceof these components into an assemblyplatform from which viral budding takesplace. How Gag exactly interacts with membranelipids and what are the mechanisms involvedin the interaction between the differentmembrane nanodomains within the assemblyplatform remains unclear. Here we review recentliterature regarding the role of Gag andlipids

  15. A study of the enhanced sensitizing capacity of a contact allergen in lipid vesicle formulations

    International Nuclear Information System (INIS)

    Simonsson, Carl; Madsen, Jakob Torp; Graneli, Annette; Andersen, Klaus E.; Karlberg, Ann-Therese; Jonsson, Charlotte A.; Ericson, Marica B.

    2011-01-01

    The growing focus on nanotechnology and the increased use of nano-sized structures, e.g. vesicles, in topical formulations has led to safety concerns. We have investigated the sensitizing capacity and penetration properties of a fluorescent model compound, rhodamine B isothiocyanate (RBITC), when administered in micro- and nano-scale vesicle formulations. The sensitizing capacity of RBITC was studied using the murine local lymph node assay (LLNA) and the skin penetration properties were compared using diffusion cells in combination with two-photon microscopy (TPM). The lymph node cell proliferation, an indicator of a compounds sensitizing capacity, increased when RBITC was applied in lipid vesicles as compared to an ethanol:water (Et:W) solution. Micro-scale vesicles showed a slightly higher cell proliferative response compared to nano-scale vesicles. TPM imaging revealed that the vesicle formulations improved the skin penetration of RBITC compared to the Et:W solution. A strong fluorescent region in the stratum corneum and upper epidermis implies elevated association of RBITC to these skin layers when formulated in lipid vesicles. In conclusion, the results indicate that there could be an elevated risk of sensitization when haptens are delivered in vehicles containing lipid vesicles. Although the size of the vesicles seems to be of minor importance, further studies are needed before a more generalized conclusion can be drawn. It is likely that the enhanced sensitizing capacity is a consequence of the improved penetration and increased formation of hapten-protein complexes in epidermis when RBITC is delivered in ethosomal formulations. - Graphical Abstract: Display Omitted

  16. Comparison of lipid emulsions on antioxidant capacity in preterm infants receiving parenteral nutrition.

    Science.gov (United States)

    Köksal, Nilgün; Kavurt, Ahmet V; Cetinkaya, Merih; Ozarda, Yesim; Ozkan, Hilal

    2011-08-01

    Although a variety of different lipid emulsions with varying fatty acid contents have been developed, there are some concerns about the administration of these lipid emulsions because of potential adverse effects, including oxidative stress-related morbidity. The aim of the present study was to evaluate and compare the effects of the standard soybean oil-based and olive oil-based i.v. lipid emulsions (ILE) on oxidative stress, determined by total antioxidant capacity (TAC), and to investigate the safety of the use of these two emulsions in terms of biochemical indices. In this prospective study, premature infants were randomly assigned to two groups, each group consisting of 32 patients who received parenteral ILE of either 20% olive oil or 20% soybean oil. They were given ILE for 7 days and then were evaluated with regard to TAC. No statistically significant difference was observed between the groups in terms of routine biochemical parameters. TAC for both groups on day 7 was significantly lower compared with that on day 0. Although the decrease in TAC within 7 days of ILE administration was greater in the soybean group compared with that in the olive oil group, it was not statistically significant. Olive oil-based ILE exhibit similar antioxidant activity and can be used as an alternative to soybean oil-based ILE. TAC significantly decreased in infants following administration of either lipid emulsion, and premature infants tolerated either ILE well, both biochemically and clinically. © 2011 The Authors. Pediatrics International © 2011 Japan Pediatric Society.

  17. Lipid peroxidation, detoxification capacity, and genome damage in mice after transplacental exposure to pharmaceutical drugs

    Directory of Open Access Journals (Sweden)

    D. Markovic

    2013-12-01

    Full Text Available Data on genome damage, lipid peroxidation, and levels of glutathione peroxidase (GPX in newborns after transplacental exposure to xenobiotics are rare and insufficient for risk assessment. The aim of the current study was to analyze, in an animal model, transplacental genotoxicity, lipid peroxidation, and detoxification disturbances caused by the following drugs commonly prescribed to pregnant women: paracetamol, fluconazole, 5-nitrofurantoin, and sodium valproate. Genome damage in dams and their newborn pups transplacentally exposed to these drugs was investigated using the in vivo micronucleus (MN assay. The drugs were administered to dams intraperitoneally in three consecutive daily doses between days 12 and 14 of pregnancy. The results were correlated, with detoxification capacity of the newborn pups measured by the levels of GPX in blood and lipid peroxidation in liver measured by malondialdehyde (HPLC-MDA levels. Sodium valproate and 5-nitrofurantoin significantly increased MN frequency in pregnant dams. A significant increase in the MN frequency of newborn pups was detected for all drugs tested. This paper also provides reference levels of MDA in newborn pups, according to which all drugs tested significantly lowered MDA levels of newborn pups, while blood GPX activity dropped significantly only after exposure to paracetamol. The GPX reduction reflected systemic oxidative stress, which is known to occur with paracetamol treatment. The reduction of MDA in the liver is suggested to be an unspecific metabolic reaction to the drugs that express cytotoxic, in particular hepatotoxic, effects associated with oxidative stress and lipid peroxidation.

  18. Supplementation of xanthophylls increased antioxidant capacity and decreased lipid peroxidation in hens and chicks.

    Science.gov (United States)

    Gao, Yu-Yun; Xie, Qing-Mei; Ma, Jing-Yun; Zhang, Xiang-Bin; Zhu, Ji-Mei; Shu, Ding-Ming; Sun, Bao-Li; Jin, Ling; Bi, Ying-Zuo

    2013-03-28

    The present study investigated the effects of xanthophyll supplementation on production performance, antioxidant capacity (measured by glutathione peroxidase, superoxide dismutase (SOD), catalase, total antioxidant capacity (T-AOC), and reduced glutathione:oxidised glutathione ratio (GSH:GSSG)) and lipid peroxidation (measured by malondialdehyde (MDA)) in breeding hens and chicks. In Expt 1, 432 hens were fed diets supplemented with 0 (control group), 20 or 40 mg xanthophyll/kg diet. Blood samples were taken at 7, 14, 21, 28 and 35 d of the trial. Liver and jejunal mucosa were sampled at 35 d. Both xanthophyll groups improved serum SOD at 21 and 28 d, serum T-AOC at 21 d and liver T-AOC, and serum GSH:GSSG at 21, 28 and 35 d and liver GSH:GSSG. Xanthophylls also decreased serum MDA at 21 d in hens. Expt 2 was a 2 × 2 factorial design. Male chicks hatched from 0 or 40 mg in ovo xanthophyll/kg diet of hens were fed a diet containing either 0 or 40 mg xanthophyll/kg diet. Liver samples were collected at 0, 7, 14 and 21 d after hatching. Blood samples were also collected at 21 d. In ovo-deposited xanthophylls increased antioxidant capacity and decreased MDA in the liver mainly within 1 week after hatching. Maternal effects gradually vanished during 1-2 weeks after hatching. Dietary xanthophylls increased antioxidant capacity and decreased MDA in the liver and serum mainly from 2 weeks onwards. Data suggested that xanthophyll supplementation enhanced antioxidant capacity and reduced lipid peroxidation in different tissues of hens and chicks.

  19. Bypassing multidrug resistance in human breast cancer cells with lipid/polymer particle assemblies

    Directory of Open Access Journals (Sweden)

    Li B

    2012-01-01

    Full Text Available Bo Li1, Hui Xu2, Zhen Li1, Mingfei Yao1, Meng Xie1, Haijun Shen1, Song Shen1, Xinshi Wang1, Yi Jin11College of Pharmaceutical sciences, Zhejiang University, Hangzhou, 2No. 202 Hospital of People's Liberation Army, Shenyang, ChinaBackground: Multidrug resistance (MDR mediated by the overexpression of adenosine triphosphate (ATP-binding cassette (ABC transporters, such as P-glycoprotein (P-gp, remains one of the major obstacles to effective cancer chemotherapy. In this study, lipid/particle assemblies named LipoParticles (LNPs, consisting of a dimethyldidodecylammonium bromide (DMAB-modified poly(lactic-co-glycolic acid (PLGA nanoparticle core surrounded by a 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC shell, were specially designed for anticancer drugs to bypass MDR in human breast cancer cells that overexpress P-gp.Methods: Doxorubicin (DOX, a chemotherapy drug that is a P-gp substrate, was conjugated to PLGA and encapsulated in the self-assembled LNP structure. Physiochemical properties of the DOX-loaded LNPs were characterized in vitro. Cellular uptake, intracellular accumulation, and cytotoxicity were compared in parental Michigan Cancer Foundation (MCF-7 cells and P-gp-overexpressing, resistant MCF-7/adriamycin (MCF-7/ADR cells.Results: This study found that the DOX formulated in LNPs showed a significantly increased accumulation in the nuclei of drug-resistant cells relative to the free drug, indicating that LNPs could alter intracellular traffic and bypass drug efflux. The cytotoxicity of DOX loaded-LNPs had a 30-fold lower half maximal inhibitory concentration (IC50 value than free DOX in MCF-7/ADR, measured by the colorimetric cell viability (MTT assay, correlated with the strong nuclear retention of the drug.Conclusion: The results show that this core-shell lipid/particle structure could be a promising strategy to bypass MDR.Keywords: chemotherapy, drug delivery, polymeric nanoparticles, multidrug resistance

  20. Pectin-lipid self-assembly: influence on the formation of polyhydroxy fatty acids nanoparticles.

    Directory of Open Access Journals (Sweden)

    Susana Guzman-Puyol

    Full Text Available Nanoparticles, named cutinsomes, have been prepared from aleuritic (9,10,16-trihidroxipalmitic acid and tomato fruit cutin monomers (a mixture of mainly 9(10,16-dihydroxypalmitic acid (85%, w/w and 16-hydroxyhexadecanoic acid (7.5%, w/w with pectin in aqueous solution. The process of formation of the nanoparticles of aleuritic acid plus pectin has been monitored by UV-Vis spectrophotometry, while their chemical and morphological characterization was analyzed by ATR-FTIR, TEM, and non-contact AFM. The structure of these nanoparticles can be described as a lipid core with a pectin shell. Pectin facilitated the formation of nanoparticles, by inducing their aggregation in branched chains and favoring the condensation between lipid monomers. Also, pectin determined the self-assembly of cutinsomes on highly ordered pyrolytic graphite (HOPG surfaces, causing their opening and forming interconnected structures. In the case of cutin monomers, the nanoparticles are fused, and the condensation of the hydroxy fatty acids is strongly affected by the presence of the polysaccharide. The interaction of pectin with polyhydroxylated fatty acids could be related to an initial step in the formation of the plant biopolyester cutin.

  1. Pectin-lipid self-assembly: influence on the formation of polyhydroxy fatty acids nanoparticles.

    Science.gov (United States)

    Guzman-Puyol, Susana; Benítez, José Jesús; Domínguez, Eva; Bayer, Ilker Sefik; Cingolani, Roberto; Athanassiou, Athanassia; Heredia, Antonio; Heredia-Guerrero, José Alejandro

    2015-01-01

    Nanoparticles, named cutinsomes, have been prepared from aleuritic (9,10,16-trihidroxipalmitic) acid and tomato fruit cutin monomers (a mixture of mainly 9(10),16-dihydroxypalmitic acid (85%, w/w) and 16-hydroxyhexadecanoic acid (7.5%, w/w)) with pectin in aqueous solution. The process of formation of the nanoparticles of aleuritic acid plus pectin has been monitored by UV-Vis spectrophotometry, while their chemical and morphological characterization was analyzed by ATR-FTIR, TEM, and non-contact AFM. The structure of these nanoparticles can be described as a lipid core with a pectin shell. Pectin facilitated the formation of nanoparticles, by inducing their aggregation in branched chains and favoring the condensation between lipid monomers. Also, pectin determined the self-assembly of cutinsomes on highly ordered pyrolytic graphite (HOPG) surfaces, causing their opening and forming interconnected structures. In the case of cutin monomers, the nanoparticles are fused, and the condensation of the hydroxy fatty acids is strongly affected by the presence of the polysaccharide. The interaction of pectin with polyhydroxylated fatty acids could be related to an initial step in the formation of the plant biopolyester cutin.

  2. Changes in non-enzymatic antioxidant capacity and lipid peroxidation during germination of white, yellow and purple maize seeds

    International Nuclear Information System (INIS)

    Deng, B.; Zhang, Y.; Yang, K.

    2016-01-01

    In this study, the changes in non-enzymatic antioxidant capacity and lipid peroxidation during the germination process of purple, yellow and white maize seeds were compared, under favorable conditions. Results showed that germination can increase non-enzymatic antioxidant capacity (evaluated with ferric reducing power and 2, 2-diphenyl-1-picryl-hydrazyl-hydrate radical scavenging capacity) and lipid peroxidation levels for all these seeds. In addition, non-enzymatic antioxidant capacity observed in the germinating seeds were in the order of purple > yellow > white. However, the highest and lowest levels of lipid peroxidation could be seen during the germination processes of the white and purple seeds, respectively. In addition, the germination rates of the seeds followed the order of white > yellow > purple. Further studies showed that H/sub 2/O/sub 2/ treatment can significantly promote seed germination, especially for purple seeds. In addition, DMTU (dimethylthiourea), a specific scavenger for H/sub 2/O/sub 2/, could slightly but significantly arrest dormancy release. Data analysis showed that a high negative correlation (R/sup 2/ = -0.955) existed between non-enzymatic antioxidant capacity and germination rates. However, a high positive correlation (R/sup 2/ = 0.860) could be detected between lipid peroxidation and germination rates. Finally, lipid peroxidation as a possible novel signaling mechanism for seed germination has been discussed under stress-free conditions. (author)

  3. Nanostructured nanoparticles of self-assembled lipid pro-drugs as a route to improved chemotherapeutic agents

    Energy Technology Data Exchange (ETDEWEB)

    Sagnella, Sharon M.; Gong, Xiaojuan; Moghaddam, Minoo J.; Conn, Charlotte E.; Kimpton, Kathleen; Waddington, Lynne J.; Krodkiewska, Irena; Drummond, Calum J. (CSIRO/MSE); (CSIRO/LW)

    2014-09-24

    We demonstrate that oral delivery of self-assembled nanostructured nanoparticles consisting of 5-fluorouracil (5-FU) lipid prodrugs results in a highly effective, target-activated, chemotherapeutic agent, and offers significantly enhanced efficacy over a commercially available alternative that does not self-assemble. The lipid prodrug nanoparticles have been found to significantly slow the growth of a highly aggressive mouse 4T1 breast tumour, and essentially halt the growth of a human MDA-MB-231 breast tumour in mouse xenografts. Systemic toxicity is avoided as prodrug activation requires a three-step, enzymatic conversion to 5-FU, with the third step occurring preferentially at the tumour site. Additionally, differences in the lipid prodrug chemical structure and internal nanostructure of the nanoparticle dictate the enzymatic conversion rate and can be used to control sustained release profiles. Thus, we have developed novel oral nanomedicines that combine sustained release properties with target-selective activation.

  4. Structure formation of lipid membranes: Membrane self-assembly and vesicle opening-up to octopus-like micelles

    Science.gov (United States)

    Noguchi, Hiroshi

    2013-02-01

    We briefly review our recent studies on self-assembly and vesicle rupture of lipid membranes using coarse-grained molecular simulations. For single component membranes, lipid molecules self-assemble from random gas states to vesicles via disk-shaped clusters. Clusters aggregate into larger clusters, and subsequently the large disks close into vesicles. The size of vesicles are determined by kinetics than by thermodynamics. When a vesicle composed of lipid and detergent types of molecules is ruptured, a disk-shaped micelle called bicelle can be formed. When both surfactants have negligibly low critical micelle concentration, it is found that bicelles connected with worm-like micelles are also formed depending on the surfactant ratio and spontaneous curvature of the membrane monolayer.

  5. Evaluation of free radical scavenging capacity and antioxidative damage effect of resveratrol-nanostructured lipid carriers

    Science.gov (United States)

    Jin, Ju; Shi, Fan; Li, Qiu-wen; Li, Pei-shan; Chen, Tong-sheng; Wang, Yi-fei; Wang, Zhi-ping

    2016-03-01

    Cellular damage induced by free-radicals like reactive oxygen species has been implicated in several diseases. 2, 2-azobis(2-amidino-propane) dihydrochloride(AAPH) generates two potent ROS capable of inducing lipid peroxidation: alkoxy radical(RO-) and peroxy radical(ROO-). These radicals are similar to those that are physiologically active and thus might initiate a cascade of intracellular toxic events leading to oxidation, lipid peroxidation, DNA damage and subsequent cell death. Hence naturally anti-oxidant play a vital role in combating these conditions. In this study, resveratrol loaded nanostructured lipid carriers (Res-NLC) was prepared by hot melting and then high pressure homogenization technique. The effects of Res-NLC on free radical scavenging capacity and antioxidative damage is investigated. The particle size and zeta potential of Res-NLC were 139.3 ± 1.7 nm and -11.21 ± 0.41 mV, respectively. By free radical scavenging assays, the IC50 value of Res-NLC were 19.25, 5.29 μg/mL with DPPH, ABTS assay respectively, and 0.161 mg ferrous sulfate/1 mg Res-NLC with FRAP assay; and by AAPH-induced oxidative injury cell model assay, Res-NLC showed the strong protective effect against the human liver tumor HepG2 cell oxidative stress damage. These results indicated that the antioxidant properties of Res-NLC hold great potential used as an alternative to more toxic synthetic antioxidants as an additive in food, cosmetic and pharmaceutical preparations for the oxidative diseases treatment.

  6. Effect of the nanoformulation of siRNA-lipid assemblies on their cellular uptake and immune stimulation

    Science.gov (United States)

    Kubota, Kohei; Onishi, Kohei; Sawaki, Kazuaki; Li, Tianshu; Mitsuoka, Kaoru; Sato, Takaaki; Takeoka, Shinji

    2017-01-01

    Two lipid-based nanoformulations have been used to date in clinical studies: lipoplexes and lipid nanoparticles (LNPs). In this study, we prepared small interfering RNA (siRNA)-loaded carriers using lipid components of the same composition to form molecular assemblies of differing structures, and evaluated the impact of structure on cellular uptake and immune stimulation. Lipoplexes are electrostatic complexes formed by mixing preformed cationic lipid liposomes with anionic siRNA in an aqueous environment, whereas LNPs are nanoparticles embedding siRNA prepared by mixing an alcoholic lipid solution with an aqueous siRNA solution in one step. Although the physicochemical properties of lipoplexes and LNPs were similar except for small increases in apparent size of lipoplexes and zeta potential of LNPs, siRNA uptake efficiency of LNPs was significantly higher than that of lipoplexes. Furthermore, in the case of LNPs, both siRNA and lipid were effectively incorporated into cells in a co-assembled state; however, in the case of lipoplexes, the amount of siRNA internalized into cells was small in comparison with lipid. siRNAs in lipoplexes were thought to be more likely to localize on the particle surface and thereby undergo dissociation into the medium. Inflammatory cytokine responses also appeared to differ between lipoplexes and LNPs. For tumor necrosis factor-α, release was mainly caused by siRNA. On the other hand, the release of interleukin-1β was mainly due to the cationic nature of particles. LNPs released lower amounts of tumor necrosis factor-α and interleukin-1β than lipoplexes and were thus considered to be better tolerated with respect to cytokine release. In conclusion, siRNA-loaded nanoformulations effect their cellular uptake and immune stimulation in a manner that depends on the structure of the molecular assembly; therefore, nanoformulations should be optimized before extending studies into the in vivo environment. PMID:28790820

  7. A lignan complex isolated from flaxseed does not affect plasma lipid concentrations or antioxidant capacity in healthy postmenopausal women

    DEFF Research Database (Denmark)

    Hallund, Jesper; Ravn-Haren, Gitte; Bügel, S.

    2006-01-01

    A lignan complex rich in the plant lignan secoisolariciresinol diglucoside (SDG) was isolated from flaxseed. SDG is metabolized by the colonic microflora to the mammalian lignans enterodiol (END) and enterolactone (ENL), and was hypothesized to reduce plasma lipid concentrations and improve...... antioxidant capacity, The aim of this study was to investigate the effects of a lignan complex, providing 500 mg/d of SDG, on serum concentration and urinary excretion of ENL, plasma lipids, serum lipoprotein oxidation resistance, and markers of antioxidant capacity. Healthy postmenopausal women (n=22...

  8. Genetically encoded lipid-polypeptide hybrid biomaterials that exhibit temperature-triggered hierarchical self-assembly

    Science.gov (United States)

    Mozhdehi, Davoud; Luginbuhl, Kelli M.; Simon, Joseph R.; Dzuricky, Michael; Berger, Rüdiger; Varol, H. Samet; Huang, Fred C.; Buehne, Kristen L.; Mayne, Nicholas R.; Weitzhandler, Isaac; Bonn, Mischa; Parekh, Sapun H.; Chilkoti, Ashutosh

    2018-05-01

    Post-translational modification of proteins is a strategy widely used in biological systems. It expands the diversity of the proteome and allows for tailoring of both the function and localization of proteins within cells as well as the material properties of structural proteins and matrices. Despite their ubiquity in biology, with a few exceptions, the potential of post-translational modifications in biomaterials synthesis has remained largely untapped. As a proof of concept to demonstrate the feasibility of creating a genetically encoded biohybrid material through post-translational modification, we report here the generation of a family of three stimulus-responsive hybrid materials—fatty-acid-modified elastin-like polypeptides—using a one-pot recombinant expression and post-translational lipidation methodology. These hybrid biomaterials contain an amphiphilic domain, composed of a β-sheet-forming peptide that is post-translationally functionalized with a C14 alkyl chain, fused to a thermally responsive elastin-like polypeptide. They exhibit temperature-triggered hierarchical self-assembly across multiple length scales with varied structure and material properties that can be controlled at the sequence level.

  9. Effect of pomegranate supplementation and aerobic training on total antioxidant capacity and lipid peroxidation in overweight men

    Directory of Open Access Journals (Sweden)

    Soheila Rahimifardin

    2014-11-01

    Results: It was found that MDA index decreased in the pomegranate supplementation group compared to placebo group (P=0.016. But, total antioxidant capacity (TAC index in neither of the groups was significant (P=0.72. Conclusion: Results of the study indicate that pomegranate supplementation can reduce MDA derived from lipid peroxidation after 8 week running training in the obese. .

  10. Haemozoin (B-haematin) biomineralization occurs by self-assembly near the lipid/water interface

    CSIR Research Space (South Africa)

    Egan, TJ

    2006-09-01

    Full Text Available remained unknown, although lipids or proteins have been suggested to catalyse its formation. We have found that B-haematin (synthetic haemozoin) forms rapidly under physiologically realistic conditions near octanol/water, pentanol/water and lipid...

  11. Short-term oleoyl-estrone treatment affects capacity to manage lipids in rat adipose tissue

    Directory of Open Access Journals (Sweden)

    Remesar Xavier

    2007-08-01

    Full Text Available Abstract Background Short-term OE (oleoyl-estrone treatment causes significant decreases in rat weight mainly due to adipose tissue loss. The aim of this work was to determine if OE treatment affects the expression of genes that regulate lipid metabolism in white adipose tissue. Results Gene expression in adipose tissue from female treated rats (48 hours was analysed by hybridization to cDNA arrays and levels of specific mRNAs were determined by real-time PCR. Treatment with OE decreased the expression of 232 genes and up-regulated 75 other genes in mesenteric white adipose tissue. The use of real-time PCR validate that, in mesenteric white adipose tissue, mRNA levels for Lipoprotein Lipase (LPL were decreased by 52%, those of Fatty Acid Synthase (FAS by 95%, those of Hormone Sensible Lipase (HSL by 32%, those of Acetyl CoA Carboxylase (ACC by 92%, those of Carnitine Palmitoyltransferase 1b (CPT1b by 45%, and those of Fatty Acid Transport Protein 1 (FATP1 and Adipocyte Fatty Acid Binding Protein (FABP4 by 52% and 49%, respectively. Conversely, Tumour Necrosis Factor (TNFα values showed overexpression (198%. Conclusion Short-term treatment with OE affects adipose tissue capacity to extract fatty acids from lipoproteins and to deal with fatty acid transport and metabolism.

  12. Short-term oleoyl-estrone treatment affects capacity to manage lipids in rat adipose tissue.

    Science.gov (United States)

    Salas, Anna; Noé, Véronique; Ciudad, Carlos J; Romero, M Mar; Remesar, Xavier; Esteve, Montserrat

    2007-08-28

    Short-term OE (oleoyl-estrone) treatment causes significant decreases in rat weight mainly due to adipose tissue loss. The aim of this work was to determine if OE treatment affects the expression of genes that regulate lipid metabolism in white adipose tissue. Gene expression in adipose tissue from female treated rats (48 hours) was analysed by hybridization to cDNA arrays and levels of specific mRNAs were determined by real-time PCR. Treatment with OE decreased the expression of 232 genes and up-regulated 75 other genes in mesenteric white adipose tissue. The use of real-time PCR validate that, in mesenteric white adipose tissue, mRNA levels for Lipoprotein Lipase (LPL) were decreased by 52%, those of Fatty Acid Synthase (FAS) by 95%, those of Hormone Sensible Lipase (HSL) by 32%, those of Acetyl CoA Carboxylase (ACC) by 92%, those of Carnitine Palmitoyltransferase 1b (CPT1b) by 45%, and those of Fatty Acid Transport Protein 1 (FATP1) and Adipocyte Fatty Acid Binding Protein (FABP4) by 52% and 49%, respectively. Conversely, Tumour Necrosis Factor (TNFalpha) values showed overexpression (198%). Short-term treatment with OE affects adipose tissue capacity to extract fatty acids from lipoproteins and to deal with fatty acid transport and metabolism.

  13. AREVA modeling and predictive capacities to support PWR fuel assembly upgrading

    International Nuclear Information System (INIS)

    Canat, J. N.; Mollard, P.; Gentet, G.; Uyeda, G.

    2008-01-01

    The first goal of the fuel designer is to closely address the customers' expectations, with the aim of providing them in the shortest possible time a flawless product fully addressing their needs. However, the designer knows from experience that designing a new fuel assembly is a task which always lasts a long time. Depending on the extent and innovative dimension of the performed changes, development and qualification of new products have lasted from a few years to as much as roughly 15 years. Experience feedback proves that developing and qualifying a cladding material is the longest-term process, requiring the determination of its behavior laws under irradiation and also under accident conditions. Regarding fuel assembly structure, new development generally requires the irradiation of Lead Test Assemblies during a period of time representative of the fuel operating conditions. This explains the critical importance of high powered, top quality modeling to adequately support the fuel assembly design development and the behavior assessment. Advanced calculation codes and methods, improved modeling tools and test facilities, are key contributors to reinforced reliability, robustness, thermal hydraulic performance and maneuverability of nuclear fuel under ever more demanding operational conditions. Sophisticated, high powered modeling tools and representative test capacities are cutting the time necessary for AREVA to develop a new product, license it and load it in the core of a reactor. This trend towards greater modeling capability has been backed up by the upgrading of computing means over the last few years, allowing the consideration of a large number of factors and a higher accuracy in the representation of the modeled phenomena. This article details how predictive tools currently play a more and more important role in the design developments engaged by AREVA. They have led to a more physical approach to finding technical solutions and allowed their analytical

  14. Synthesis and characterization of tethered lipid assemblies for membrane protein reconstitution (Review).

    Science.gov (United States)

    Veneziano, Rémi; Rossi, Claire; Chenal, Alexandre; Brenner, Catherine; Ladant, Daniel; Chopineau, Joël

    2017-09-28

    Biological membranes and their related molecular mechanisms are essential for all living organisms. Membranes host numerous proteins and are responsible for the exchange of molecules and ions, cell signaling, and cell compartmentation. Indeed, the plasma membrane delimits the intracellular compartment from the extracellular environment and intracellular membranes. Biological membranes also play a major role in metabolism regulation and cellular physiology (e.g., mitochondrial membranes). The elaboration of membrane based biomimetic systems allows us to reconstitute and investigate, in controlled conditions, biological events occurring at the membrane interface. A whole variety of model membrane systems have been developed in the last few decades. Among these models, supported membranes were developed on various hydrophilic supports. The use of solid supports enables the direct use of surface sensitive techniques (e.g., surface plasmon resonance, quartz crystal microbalance, and atomic force microscopy) to monitor and quantify events occurring at the membrane surface. Tethered bilayer membranes (tBLMs) could be considered as an achievement of the first solid supported membranes described by the McConnell group. Tethered bilayers on solid supports were designed to delimit an inside compartment from an outside one. They were used for measuring interactions with ligands or incorporating large membrane proteins or complexes without interference with the support. In this context, the authors developed an easy concept of versatile tBLMs assembled on amino coated substrates that are formed upon the vesicle fusion rupture process applicable to protein-free vesicles as well as proteoliposomes. The phospholipid bilayer (natural or synthetic lipids) incorporated 5% of 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-poly ethylene glycol-N-hydroxy succinimide to ensure the anchorage of the bilayer to the amino coated surface. The conditions for the formation of tBLMs on amino

  15. Self-Assembled Core-Shell-Type Lipid-Polymer Hybrid Nanoparticles: Intracellular Trafficking and Relevance for Oral Absorption.

    Science.gov (United States)

    Li, Qiuxia; Xia, Dengning; Tao, Jinsong; Shen, Aijun; He, Yuan; Gan, Yong; Wang, Chi

    2017-10-01

    Lipid-polymer hybrid nanoparticles (NPs) are advantageous for drug delivery. However, their intracellular trafficking mechanism and relevance for oral drug absorption are poorly understood. In this study, self-assembled core-shell lipid-polymer hybrid NPs made of poly(lactic-co-glycolic acid) (PLGA) and various lipids were developed to study their differing intracellular trafficking in intestinal epithelial cells and their relevance for oral absorption of a model drug saquinavir (SQV). Our results demonstrated that the endocytosis and exocytosis of hybrid NPs could be changed by varying the kind of lipid. A glyceride mixture (hybrid NPs-1) decreased endocytosis but increased exocytosis in Caco-2 cells, whereas the phospholipid (E200) (hybrid NPs-2) decreased endocytosis but exocytosis was unaffected as compared with PLGA nanoparticles. The transport of hybrid NPs-1 in cells involved various pathways, including caveolae/lipid raft-dependent endocytosis, and clathrin-mediated endocytosis and macropinocytosis, which was different from the other groups of NPs that involved only caveolae/lipid raft-dependent endocytosis. Compared with that of the reference formulation (nanoemulsion), the oral absorption of SQV-loaded hybrid NPs in rats was poor, probably due to the limited drug release and transcytosis of NPs across the intestinal epithelium. In conclusion, the intracellular processing of hybrid NPs in intestinal epithelia can be altered by adding lipids to the NP. However, it appears unfavorable to use PLGA-based NPs to improve oral absorption of SQV compared with nanoemulsion. Our findings will be essential in the development of polymer-based NPs for the oral delivery of drugs with the purpose of improving their oral absorption. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  16. Salivary Total Antioxidant Capacity and Lipid Peroxidation in Patients with Erosive Oral Lichen Planus

    Directory of Open Access Journals (Sweden)

    Atena Shirzad

    2014-03-01

    Full Text Available Background and aims. Oral lichen planus is a common chronic inflammatory disease of the oral mucosa with malignant potential, pathogenesis of which is not still well known. Free radicals and reactive oxygen species can play an important role in the pathogenesis of oral lichen planus. The aim of this study was to investigate salivary oxidative stress and antioxidant systems in patients with oral lichen planus. Materials and methods. In this case-control study, 30 patients with oral lichen planus (case group and 30 age- and gender-matched healthy subjects (control group, referring to Dental School of Babol University of Medical Sciences, were selected using simple sampling method. Unstimulated saliva of the two groups was collected. Salivary total antioxidant capacity (TAC and lipid peroxidation products were investigated and compared, using ferric reducing antioxidant power (FRAP and thiobarbituric acid reactive substance (TBARS methods, respectively. Data were analyzed using Student’s ttest. Results. The mean and standard deviation of salivary TAC in patients with oral lichen planus (297.23 ± 149.72 μM was significantly lower than that in the controls (791.43±183.95 μM; P < 0.0001, and mean and standard deviation of salivary malondialdehyde (MDA (0.49 ± 0.30 μM was remarkably higher in oral lichen planus patients compared to the control group (0.15 ± 0.11 μM (P < 0.0001. TAC was also reduced in both groups in line with an increase in the level of MDA (P < 0.0001, r = −0.48. Conclusion. The results of this study suggested that an increase in oxidative stress and an imbalance in antioxidant defense system in the saliva of oral lichen planus patients may be involved in the pathogenesis of oral lichen planus.

  17. Salivary total antioxidant capacity and lipid peroxidation in patients with erosive oral lichen planus.

    Science.gov (United States)

    Shirzad, Atena; Pouramir, Mahdi; Seyedmajidi, Maryam; Jenabian, Niloofar; Bijani, Ali; Motallebnejad, Mina

    2014-01-01

    Background and aims. Oral lichen planus is a common chronic inflammatory disease of the oral mucosa with malignant potential, pathogenesis of which is not still well known. Free radicals and reactive oxygen species can play an important role in the pathogenesis of oral lichen planus. The aim of this study was to investigate salivary oxidative stress and antioxidant systems in patients with oral lichen planus. Materials and methods. In this case-control study, 30 patients with oral lichen planus (case group) and 30 age-and gender-matched healthy subjects (control group), referring to Dental School of Babol University of Medical Sciences, were selected using simple sampling method. Unstimulated saliva of the two groups was collected. Salivary total antioxidant capacity (TAC) and lipid peroxidation products were investigated and compared, using ferric reducing antioxidant power (FRAP) and thiobarbituric acid reactive substance (TBARS) methods, respectively. Data were analyzed using Student' t-test. Results. The mean and standard deviation of salivary TAC in patients with oral lichen planus (297.23 ± 149.72 μM) was significantly lower than that in the controls (791.43 ± 183.95 μM; P & 0.0001), and mean and standard deviation of salivary malondialdehyde (MDA) (0.49 ± 0.30 μM) was remarkably higher in oral lichen planus patients compared to the control group (0.15 ± 0.11 μM) (P & 0.0001). TAC was also reduced in both groups in line with an increase in the level of MDA (P & 0.0001, r = -0.48). Conclusion. The results of this study suggested that an increase in oxidative stress and an imbalance in antioxidant defense system in the saliva of oral lichen planus patients may be involved in the pathogenesis of oral lichen planus.

  18. Effect of gamma radiation on total antioxidant capacity, total lipid concentration and shelf life of finger millet flour

    International Nuclear Information System (INIS)

    Lathika; Manupriya, B.R.; Shenoy, K.B.; Patil, S.L.; Somashekarappa, H.M.

    2016-01-01

    The present study is an attempt to study the impact of gamma radiation on the shelf life, total antioxidant capacity and total lipid concentration of finger millet (Eleusine coracana L.) flour. Finger millet flour was procured from market. Flour samples of 50 g were taken in triplicates in a polyethylene pouch, air sealed and subjected to gamma irradiation doses ranging from 0.25 to 10 kGy and stored in polyethylene bags and plastic containers for a period of 1 year. Within 24 hours of irradiation, the samples were tested for moisture (2 ± 0.2%), total antioxidant capacity (0.12 ± 0.010 mg) and lipid concentration (15 ± 0.4 mg)

  19. Structurally modified pectin for targeted lipid antioxidant capacity in linseed/sunflower oil-in-water emulsions.

    Science.gov (United States)

    Celus, Miete; Salvia-Trujillo, Laura; Kyomugasho, Clare; Maes, Ine; Van Loey, Ann M; Grauwet, Tara; Hendrickx, Marc E

    2018-02-15

    The present work explored the lipid antioxidant capacity of citrus pectin addition to 5%(w/v) linseed/sunflower oil emulsions stabilized with 0.5%(w/v) Tween 80, as affected by pectin molecular characteristics. The peroxide formation in the emulsions, containing tailored pectin structures, was studied during two weeks of storage at 35°C. Low demethylesterified pectin (≤33%) exhibited a higher antioxidant capacity than high demethylesterified pectin (≥58%), probably due to its higher chelating capacity of pro-oxidative metal ions (Fe 2+ ), whereas the distribution pattern of methylesters along the pectin chain only slightly affected the antioxidant capacity. Nevertheless, pectin addition to the emulsions caused emulsion destabilization probably due to depletion or bridging effect, independent of the pectin structural characteristics. These results evidence the potential of structurally modified citrus pectin as a natural antioxidant in emulsions. However, optimal conditions for emulsion stability should be carefully selected. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Effects of different rearing and feeding systems on lipid oxidation and antioxidant capacity of freeze-dried egg yolks.

    Science.gov (United States)

    Pignoli, Giovanni; Rodriguez-Estrada, Maria Teresa; Mandrioli, Mara; Barbanti, Lorenzo; Rizzi, Laura; Lercker, Giovanni

    2009-12-23

    Lipid oxidation and antioxidant capacity of freeze-dried egg yolks produced with two rearing systems (battery cages and free-range) and two types of feedings (conventional and organic) were studied. Nine fresh egg yolks of each crossed treatment were pooled, frozen for a month, freeze-dried, vacuum-packed, and kept at -18 degrees C until analysis. No significant differences were observed in the lipid (58.0-62.1%) and total sterol contents (33.0-35.5 g/kg of lipids) of the freeze-dried egg yolks. Free rearing and conventional feeding systems resulted in significantly higher total tocopherol, alpha-tocopherol, and lutein contents, as compared to the battery cage and the organic feed, respectively. However, no significant differences were found in lipid oxidation (peroxide value = 0.7-0.9 mequiv of O(2)/kg of fat; thiobarbituric reactive substances = 1.0-1.3 mg of malonylaldehyde/kg of sample) and cholesterol oxidation (28.8-43.5 mg of cholesterol oxidation products/kg of lipids; 0.08-0.12% oxidized cholesterol) of freeze-dried egg yolks except for 7alpha-hydroxycholesterol, which was significantly lower in samples obtained with organic feed.

  1. The effects of different lipid emulsions on the lipid profile, fatty acid composition, and antioxidant capacity of preterm infants: A double-blind, randomized clinical trial.

    Science.gov (United States)

    Wang, Ying; Feng, Yi; Lu, Li-Na; Wang, Wei-Ping; He, Zhen-Juan; Xie, Li-Juan; Hong, Li; Tang, Qing-Ya; Cai, Wei

    2016-10-01

    Olive oil (OO), medium-chain triglycerides (MCT)/long-chain triglycerides (LCT) mixture and soybean oil (SO) lipid emulsions are currently used for preterm infants in China. The aim of our study was to compare the lipid profile, fatty acid composition, and antioxidant capacity of preterm infants administered OO, MCT/LCT, or SO lipid emulsions. In this study, 156 preterm infants (birth weight emulsions for a minimum of 14 d. On days 0, 7, and 14, the lipid profile, fatty acid composition and antioxidant capacity were analyzed. On day 7, HDL levels in the MCT/LCT group were significantly lower than in the OO (1.06 ± 0.40 mmol/L) or SO groups. LDL levels were higher in the OO group than in the MCT/LCT or SO groups on day 7. A-I/B was higher in MCT/LCT than in OO or SO groups. Myristic acid (C14:0) levels on days 7 and 14 increased in MCT/LCT compared to the OO and SO groups. The OO group had higher oleic acid (C18:1n9) levels than the two other groups. Linoleic acid (C18:2n6), linolenic acid (C18:3n3), and eicosapentaenoic acid (20:5n3) were significantly lower in the OO group than in MCT/LCT or SO groups. Monounsaturated fatty acid levels decreased, and ω-6 polyunsaturated fatty acid and essential fatty acids levels increased in MCT/LCT and SO groups. No significant differences were obtained in SOD, MDA, GSH-Px, and T-AOC among the groups. The three lipid emulsions were safe and well tolerated in preterm infants. Oleic acid (C18:1n9) levels increased and LA (C18:2n6), ALA (C18:3n3), and EPA (C20:5n23) levels decreased in OO compared to MCT/LCT or SO. NCT01683162, https://register.clinicaltrials.gov/. Copyright © 2015 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  2. Chiral hierarchical self-assembly in Langmuir monolayers of diacetylenic lipids

    KAUST Repository

    Basnet, Prem B.; Mandal, Pritam; Malcolm, Dominic W.; Mann, Elizabeth; Chaieb, Saharoui

    2013-01-01

    When compressed in the intermediate temperature range below the chain-melting transition yet in the low-pressure liquid phase, Langmuir monolayers made of chiral lipid molecules form hierarchical structures. Using Brewster angle microscopy to reveal

  3. Changes in the lipid composition of blood under the influence of a single submaximal exercise capacity (experimental research.

    Directory of Open Access Journals (Sweden)

    Ermolaeva E.N.

    2015-06-01

    Full Text Available In acute physical exercise, there is a change in oxygen delivery working tissues, blood gas transport function and efficiency of the use of oxygen by cells in the process of metabolism, which is the basis for compensation for physical activities. Lipid metabolism plays an important role in the energy supply of muscle activity. The aim of our research is to study the effect of a single submaximal exercise capacity by changing the lipid profile of peripheral blood. Materials and Methods. The study was performed on 18 white rats. Model of acute exercise: animals swam 4 minutes with a load weighing 20% of body weight. Blood sampling was performed by intracardiac way, right after exercise. The blood lipid profile was determined. Results. In the experiment reported an increase in triglycerides, total cholesterol, very low-density lipoproteins, but the atherogenic ratio is maintained at the control values, due to a significant increase in the level of high-density lipoprotein. Conclusion. Acute submaximal exercise capacity by untrained body has an atherogenic effect. Working muscles during physical activity is a major consumer of free fatty acids, which are the source of atherogenic lipoprotein form of the very low and low density.

  4. 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.

  5. Effect of the nanoformulation of siRNA-lipid assemblies on their cellular uptake and immune stimulation

    Directory of Open Access Journals (Sweden)

    Kubota K

    2017-07-01

    Full Text Available Kohei Kubota,1,2 Kohei Onishi,3 Kazuaki Sawaki,3 Tianshu Li,4 Kaoru Mitsuoka,5 Takaaki Sato,6 Shinji Takeoka1,3,4 1Cooperative Major in Advanced Biomedical Sciences, Graduate School of Advanced Sciences and Engineering, Waseda University (TWIns, Tokyo, Japan; 2Formulation Research and Phramaceutical Process Group, CMC R&D Center, Kyowa Hakko Kirin Co., Ltd, Shizuoka, Japan; 3Department of Life Science and Medical Bioscience, Graduate School of Advanced Science and Engineering,Waseda University (TWIns, Tokyo, Japan; 4Research Organization for Nano and Life Innovation, Waseda University (TWIns, Tokyo, Japan; 5Research Center for Ultra-High Voltage Electron Microscopy, Osaka University, Osaka, Japan; 6Department of Chemistry and Materials, Faculty of Textile Science and Technology, Shinshu University, Nagano, Japan Abstract: Two lipid-based nanoformulations have been used to date in clinical studies: lipoplexes and lipid nanoparticles (LNPs. In this study, we prepared small interfering RNA (siRNA-loaded carriers using lipid components of the same composition to form molecular assemblies of differing structures, and evaluated the impact of structure on cellular uptake and immune stimulation. Lipoplexes are electrostatic complexes formed by mixing preformed cationic lipid liposomes with anionic siRNA in an aqueous environment, whereas LNPs are nanoparticles embedding siRNA prepared by mixing an alcoholic lipid solution with an aqueous siRNA solution in one step. Although the physicochemical properties of lipoplexes and LNPs were similar except for small increases in apparent size of lipoplexes and zeta potential of LNPs, siRNA uptake efficiency of LNPs was significantly higher than that of lipoplexes. Furthermore, in the case of LNPs, both siRNA and lipid were effectively incorporated into cells in a co-assembled state; however, in the case of lipoplexes, the amount of siRNA internalized into cells was small in comparison with lipid. siRNAs in

  6. Distinct populations of hepatic stellate cells in the mouse liver have different capacities for retinoid and lipid storage.

    Directory of Open Access Journals (Sweden)

    Diana N D'Ambrosio

    Full Text Available Hepatic stellate cell (HSC lipid droplets are specialized organelles for the storage of retinoid, accounting for 50-60% of all retinoid present in the body. When HSCs activate, retinyl ester levels progressively decrease and the lipid droplets are lost. The objective of this study was to determine if the HSC population in a healthy, uninjured liver demonstrates heterogeneity in its capacity for retinoid and lipid storage in lipid droplets. To this end, we utilized two methods of HSC isolation, which leverage distinct properties of these cells, including their vitamin A content and collagen expression. HSCs were isolated either from wild type (WT mice in the C57BL/6 genetic background by flotation in a Nycodenz density gradient, followed by fluorescence activated cell sorting (FACS based on vitamin A autofluorescence, or from collagen-green fluorescent protein (GFP mice by FACS based on GFP expression from a GFP transgene driven by the collagen I promoter. We show that GFP-HSCs have: (i increased expression of typical markers of HSC activation; (ii decreased retinyl ester levels, accompanied by reduced expression of the enzyme needed for hepatic retinyl ester synthesis (LRAT; (iii decreased triglyceride levels; (iv increased expression of genes associated with lipid catabolism; and (v an increase in expression of the retinoid-catabolizing cytochrome, CYP2S1.Our observations suggest that the HSC population in a healthy, uninjured liver is heterogeneous. One subset of the total HSC population, which expresses early markers of HSC activation, may be "primed" and ready for rapid response to acute liver injury.

  7. Effect of floorball training on blood lipids, body composition, muscle strength, and functional capacity of elderly men

    DEFF Research Database (Denmark)

    Vorup Petersen, Jacob; Pedersen, Mogens Theisen; Melcher, Pia Grethe Sandfeld

    2017-01-01

    Floorball training consists of intense repeated exercise and may offer a motivating and social stimulating team activity in elderly individuals. However, the effect of floorball training in elderly adults on physiological adaptations important for health is not known. Thus, this study examined...... the effect of floorball training on blood lipids, muscle strength, body composition, and functional capacity of men aged 65-76 years. Thirty-nine recreational active men were randomized into a floorball group (FG; n = 22) or petanque group (PG; n = 17), in which training was performed 1 h twice a week for 12......-IR) was reduced (P performance in four different...

  8. Improved lipid profile and increased serum antioxidant capacity in healthy volunteers after Sambucus ebulus L. fruit infusion consumption.

    Science.gov (United States)

    Ivanova, Diana; Tasinov, Oskan; Kiselova-Kaneva, Yoana

    2014-09-01

    This study aimed to establish the effect of Sambucus ebulus L. (SE) ripe fruit infusion on body weight, blood pressure, glucose levels, lipid profile and antioxidant markers in healthy volunteers in respect of its possible protective activity against cardiovascular diseases and other oxidative stress-related diseases. The study involved 21 healthy volunteers, aged between 20 and 59, BMI 23.12 ± 1.31, who consumed 200 ml SE infusion/day for a period of 30 d. Blood samples were collected before and at the end of the intervention. Significant decrease in triglycerides (14.92%), total cholesterol (15.04%) and LDL-C (24.67%) was established at the end of the study. In addition, HDL-C/LDL-C ratio increased by 42.77%. Improved serum antioxidant capacity and total thiol levels were also established. The results presented in this first human intervention study with SE fruit infusion indicate the potential of the plant to improve lipid profile and serum antioxidant capacity in humans.

  9. Vehicles of inverted hexagonal liquid crystalline lipid phases self-assembled at room temperature

    Czech Academy of Sciences Publication Activity Database

    Angelov, Borislav; Angelova, A.; Garamus, V. M.; Lesieur, S.

    2013-01-01

    Roč. 15, 3/4 (2013), s. 211-215 ISSN 1454-4164 R&D Projects: GA ČR GAP208/10/1600 Institutional support: RVO:61389013 Keywords : liquid crystalline lipid nanoparticles * small angle X-ray scattering * cross-polarised light optical microscopy Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.563, year: 2013 http://joam.inoe.ro/index.php?option=magazine&op=view&idu=3179&catid=76

  10. Interaction of Ionic Liquids with Lipid Biomembrane: Implication from Supramolecular Assembly to Cytotoxicity

    Science.gov (United States)

    Jing, Benxin; Lan, Nan; Zhu, Y. Elaine

    2013-03-01

    An explosion in the research activities using ionic liquids (ILs) as new ``green'' chemicals in several chemical and biomedical processes has resulted in the urgent need to understand their impact in term of their transport and toxicity towards aquatic organisms. Though a few experimental toxicology studies have reported that some ionic liquids are toxic with increased hydrophobicity of ILs while others are not, our understanding of the molecular level mechanism of IL toxicity remains poorly understood. In this talk, we will discuss our recent study of the interaction of ionic liquids with model cell membranes. We have found that the ILs could induce morphological change of lipid bilayers when a critical concentration is exceeded, leading to the swelling and tube-like formation of lipid bilayers. The critical concentration shows a strong dependence on the length of hydrocarbon tails and hydrophobic counterions. By SAXS, Langmuir-Blodgett (LB) and fluorescence microscopic measurement, we have confirmed that tube-like lipid complexes result from the insertion of ILs with long hydrocarbon chains to minimize the hydrophobic interaction with aqueous media. This finding could give insight to the modification and adoption of ILs for the engineering of micro-organisms.

  11. Mismatch discrimination of lipidated DNA and LNA-probes (LiNAs) in hybridization-controlled liposome assembly

    DEFF Research Database (Denmark)

    Jakobsen, Ulla; Vogel, Stefan

    2016-01-01

    Assays for mismatch discrimination and detection of single nucleotide variations by hybridization-controlled assembly of liposomes, which do not require tedious surface chemistry, are versatile for both DNA and RNA targets. We report herein a comprehensive study on different DNA and LNA (locked...... assay in the context of mismatch discrimination and SNP detection are presented. The advantages of membrane-anchored LiNA-probes compared to chemically attached probes on solid nanoparticles (e.g. gold nanoparticles) are described. Key functionalities such as non-covalent attachment of LiNA probes...... without the need for long spacers and the inherent mobility of membrane-anchored probes in lipid-bilayer membranes will be described for several different probe designs....

  12. Self-Assembled Lipid Nanoparticles for Oral Delivery of Heparin-Coated Iron Oxide Nanoparticles for Theranostic Purposes.

    Science.gov (United States)

    Truzzi, Eleonora; Bongio, Chiara; Sacchetti, Francesca; Maretti, Eleonora; Montanari, Monica; Iannuccelli, Valentina; Vismara, Elena; Leo, Eliana

    2017-06-09

    Recently, solid lipid nanoparticles (SLNs) have attracted increasing attention owing to their potential as an oral delivery system, promoting intestinal absorption in the lymphatic circulation which plays a role in disseminating metastatic cancer cells and infectious agents throughout the body. SLN features can be exploited for the oral delivery of theranostics. Therefore, the aim of this work was to design and characterise self-assembled lipid nanoparticles (SALNs) to encapsulate and stabilise iron oxide nanoparticles non-covalently coated with heparin (Fe@hepa) as a model of a theranostic tool. SALNs were characterised for physico-chemical properties (particle size, surface charge, encapsulation efficiency, in vitro stability, and heparin leakage), as well as in vitro cytotoxicity by methyl thiazole tetrazolium (MTT) assay and cell internalisation in CaCo-2, a cell line model used as an indirect indication of intestinal lymphatic absorption. SALNs of about 180 nm, which are stable in suspension and have a high encapsulation efficiency (>90%) were obtained. SALNs were able to stabilise the heparin coating of Fe@hepa, which are typically unstable in physiological environments. Moreover, SALNs-Fe@hepa showed no cytotoxicity, although their ability to be internalised into CaCo-2 cells was highlighted by confocal microscopy analysis. Therefore, the results indicated that SALNs can be considered as a promising tool to orally deliver theranostic Fe@hepa into the lymphatic circulation, although further in vivo studies are needed to comprehend further potential applications.

  13. Effect of floorball training on blood lipids, body composition, muscle strength, and functional capacity of elderly men.

    Science.gov (United States)

    Vorup, J; Pedersen, M T; Melcher, P S; Dreier, R; Bangsbo, J

    2017-11-01

    Floorball training consists of intense repeated exercise and may offer a motivating and social stimulating team activity in elderly individuals. However, the effect of floorball training in elderly adults on physiological adaptations important for health is not known. Thus, this study examined the effect of floorball training on blood lipids, muscle strength, body composition, and functional capacity of men aged 65-76 years. Thirty-nine recreational active men were randomized into a floorball group (FG; n = 22) or petanque group (PG; n = 17), in which training was performed 1 h twice a week for 12 weeks. In FG and PG, average heart rate (HR) during training was 80% and 57%, respectively, of maximal HR. In FG, plasma low-density lipoprotein (LDL) cholesterol and triglycerides were 11% and 8% lower (P functional capacity tests were better (P training period. No changes were observed in PG. In conclusion, 12 weeks of floorball training resulted in a number of favorable effects important for health and functional capacity, suggesting that floorball training can be used as a health-promoting activity in elderly men. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  14. Effects of a high-intensity intermittent training program on aerobic capacity and lipid profile in trained subjects

    Directory of Open Access Journals (Sweden)

    Ouerghi N

    2014-10-01

    Full Text Available Nejmeddine Ouerghi,1,2 Marwa Khammassi,1 Sami Boukorraa,1 Moncef Feki,2 Naziha Kaabachi,2 Anissa Bouassida,1,3 1Research Unit, Sportive Performance and Physical Rehabilitation, High Institute of Sports and Physical Education of Kef, University of Jendouba, Kef, Tunisia, 2Laboratory of Biochemistry, Rabta Hospital, Faculty of Medicine of Tunis, El Manar University, Tunis, 3Physiology Laboratory, Faculty of Medicine Ibn el Jazzar, Sousse, Tunisia Background: Data regarding the effect of training on plasma lipids are controversial. Most studies have addressed continuous or long intermittent training programs. The present study evaluated the effect of short-short high-intensity intermittent training (HIIT on aerobic capacity and plasma lipids in soccer players. Methods: The study included 24 male subjects aged 21–26 years, divided into three groups: experimental group 1 (EG1, n=8 comprising soccer players who exercised in addition to regular short-short HIIT twice a week for 12 weeks; experimental group 2 (EG2, n=8 comprising soccer players who exercised in a regular football training program; and a control group (CG, n=8 comprising untrained subjects who did not practice regular physical activity. Maximal aerobic velocity and maximal oxygen uptake along with plasma lipids were measured before and after 6 weeks and 12 weeks of the respective training program. Results: Compared with basal values, maximal oxygen uptake had significantly increased in EG1 (from 53.3±4.0 mL/min/kg to 54.8±3.0 mL/min/kg at 6 weeks [P<0.05] and to 57.0±3.2 mL/min/kg at 12 weeks [P<0.001]. Maximal oxygen uptake was increased only after 12 weeks in EG2 (from 52.8±2.7 mL/min/kg to 54.2±2.6 mL/min/kg, [P<0.05], but remain unchanged in CG. After 12 weeks of training, maximal oxygen uptake was significantly higher in EG1 than in EG2 (P<0.05. During training, no significant changes in plasma lipids occurred. However, after 12 weeks, total and low-density lipoprotein

  15. Chiral hierarchical self-assembly in Langmuir monolayers of diacetylenic lipids

    KAUST Repository

    Basnet, Prem B.

    2013-01-01

    When compressed in the intermediate temperature range below the chain-melting transition yet in the low-pressure liquid phase, Langmuir monolayers made of chiral lipid molecules form hierarchical structures. Using Brewster angle microscopy to reveal this structure, we found that as the liquid monolayer is compressed, an optically anisotropic condensed phase nucleates in the form of long, thin claws. These claws pack closely to form stripes. This appears to be a new mechanism for forming stripes in Langmuir monolayers. In the lower temperature range, these stripes arrange into spirals within overall circular domains, while near the chain-melting transition, the stripes arrange into target patterns. We attributed this transition to a change in boundary conditions at the core of the largest-scale circular domains. © 2013 The Royal Society of Chemistry.

  16. Gag induces the coalescence of clustered lipid rafts and tetraspanin-enriched microdomains at HIV-1 assembly sites on the plasma membrane.

    Science.gov (United States)

    Hogue, Ian B; Grover, Jonathan R; Soheilian, Ferri; Nagashima, Kunio; Ono, Akira

    2011-10-01

    The HIV-1 structural protein Gag associates with two types of plasma membrane microdomains, lipid rafts and tetraspanin-enriched microdomains (TEMs), both of which have been proposed to be platforms for HIV-1 assembly. However, a variety of studies have demonstrated that lipid rafts and TEMs are distinct microdomains in the absence of HIV-1 infection. To measure the impact of Gag on microdomain behaviors, we took advantage of two assays: an antibody-mediated copatching assay and a Förster resonance energy transfer (FRET) assay that measures the clustering of microdomain markers in live cells without antibody-mediated patching. We found that lipid rafts and TEMs copatched and clustered to a greater extent in the presence of membrane-bound Gag in both assays, suggesting that Gag induces the coalescence of lipid rafts and TEMs. Substitutions in membrane binding motifs of Gag revealed that, while Gag membrane binding is necessary to induce coalescence of lipid rafts and TEMs, either acylation of Gag or binding of phosphatidylinositol-(4,5)-bisphosphate is sufficient. Finally, a Gag derivative that is defective in inducing membrane curvature appeared less able to induce lipid raft and TEM coalescence. A higher-resolution analysis of assembly sites by correlative fluorescence and scanning electron microscopy showed that coalescence of clustered lipid rafts and TEMs occurs predominantly at completed cell surface virus-like particles, whereas a transmembrane raft marker protein appeared to associate with punctate Gag fluorescence even in the absence of cell surface particles. Together, these results suggest that different membrane microdomain components are recruited in a stepwise manner during assembly.

  17. Gag Induces the Coalescence of Clustered Lipid Rafts and Tetraspanin-Enriched Microdomains at HIV-1 Assembly Sites on the Plasma Membrane ▿

    Science.gov (United States)

    Hogue, Ian B.; Grover, Jonathan R.; Soheilian, Ferri; Nagashima, Kunio; Ono, Akira

    2011-01-01

    The HIV-1 structural protein Gag associates with two types of plasma membrane microdomains, lipid rafts and tetraspanin-enriched microdomains (TEMs), both of which have been proposed to be platforms for HIV-1 assembly. However, a variety of studies have demonstrated that lipid rafts and TEMs are distinct microdomains in the absence of HIV-1 infection. To measure the impact of Gag on microdomain behaviors, we took advantage of two assays: an antibody-mediated copatching assay and a Förster resonance energy transfer (FRET) assay that measures the clustering of microdomain markers in live cells without antibody-mediated patching. We found that lipid rafts and TEMs copatched and clustered to a greater extent in the presence of membrane-bound Gag in both assays, suggesting that Gag induces the coalescence of lipid rafts and TEMs. Substitutions in membrane binding motifs of Gag revealed that, while Gag membrane binding is necessary to induce coalescence of lipid rafts and TEMs, either acylation of Gag or binding of phosphatidylinositol-(4,5)-bisphosphate is sufficient. Finally, a Gag derivative that is defective in inducing membrane curvature appeared less able to induce lipid raft and TEM coalescence. A higher-resolution analysis of assembly sites by correlative fluorescence and scanning electron microscopy showed that coalescence of clustered lipid rafts and TEMs occurs predominately at completed cell surface virus-like particles, whereas a transmembrane raft marker protein appeared to associate with punctate Gag fluorescence even in the absence of cell surface particles. Together, these results suggest that different membrane microdomain components are recruited in a stepwise manner during assembly. PMID:21813604

  18. Motor adaptation capacity as a function of age in carrying out a repetitive assembly task at imposed work paces.

    Science.gov (United States)

    Gilles, Martine Annie; Guélin, Jean-Charles; Desbrosses, Kévin; Wild, Pascal

    2017-10-01

    The working population is getting older. Workers must adapt to changing conditions to respond to the efforts required by the tasks they have to perform. In this laboratory-based study, we investigated the capacities of motor adaptation as a function of age and work pace. Two phases were identified in the task performed: a collection phase, involving dominant use of the lower limbs; and an assembly phase, involving bi-manual motor skills. Results showed that senior workers were mainly limited during the collection phase, whereas they had less difficulty completing the assembly phase. However, senior workers did increase the vertical force applied while assembling parts, whatever the work pace. In younger and middle-aged subjects, vertical force was increased only for the faster pace. Older workers could adapt to perform repetitive tasks under different time constraints, but adaptation required greater effort than for younger workers. These results point towards a higher risk of developing musculoskeletal disorders among seniors. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Calcium-binding capacity of centrin2 is required for linear POC5 assembly but not for nucleotide excision repair.

    Directory of Open Access Journals (Sweden)

    Tiago J Dantas

    Full Text Available Centrosomes, the principal microtubule-organising centres in animal cells, contain centrins, small, conserved calcium-binding proteins unique to eukaryotes. Centrin2 binds to xeroderma pigmentosum group C protein (XPC, stabilising it, and its presence slightly increases nucleotide excision repair (NER activity in vitro. In previous work, we deleted all three centrin isoforms present in chicken DT40 cells and observed delayed repair of UV-induced DNA lesions, but no centrosome abnormalities. Here, we explore how centrin2 controls NER. In the centrin null cells, we expressed centrin2 mutants that cannot bind calcium or that lack sites for phosphorylation by regulatory kinases. Expression of any of these mutants restored the UV sensitivity of centrin null cells to normal as effectively as expression of wild-type centrin. However, calcium-binding-deficient and T118A mutants showed greatly compromised localisation to centrosomes. XPC recruitment to laser-induced UV-like lesions was only slightly slower in centrin-deficient cells than in controls, and levels of XPC and its partner HRAD23B were unaffected by centrin deficiency. Interestingly, we found that overexpression of the centrin interactor POC5 leads to the assembly of linear, centrin-dependent structures that recruit other centrosomal proteins such as PCM-1 and NEDD1. Together, these observations suggest that assembly of centrins into complex structures requires calcium binding capacity, but that such assembly is not required for centrin activity in NER.

  20. Effect of radiation therapy on lipid peroxidation and total antioxidant capacity of blood and saliva in oral cancer patients

    International Nuclear Information System (INIS)

    Lobo, Aswin D.A.

    2012-01-01

    Radiation therapy is reported to induce oxidative stress in oral cancer patients. Saliva as a diagnostic tool has received increasing attention in recent years. Saliva analysis is proposed to be a noninvasive, sensitive tool for the evaluation of biological effects of radiation therapy in oral cancer. We aimed to assess the effect of radiation therapy on malondialdehyde, the marker of lipid peroxidation, and total antioxidant capacity in blood and saliva of oral cancer patients. We also aimed to assess the correlation between blood and saliva with respect to malonaldehyde (MDA) level and total antioxidant capacity (TAC). Thirty, clinically diagnosed oral cancer patients visiting the Oncology Department were the subjects. Thirty age- and sex-matched normal, healthy controls were included. Blood and saliva samples were collected from controls, and from oral cancer patients before and after radiation therapy. The samples were analyzed for MDA and TAC by standard spectrophotometric methods. Oral cancer patients showed significantly higher MDA level and lower TAC in blood and saliva when compared to controls. One week after radiation therapy, there was significant increase in MDA and decrease in TAC in oral cancer patients. After the completion of radiation therapy of six weeks, MDA level decreased and TAC increased, restoring the values near-to-controls. The pattern of change in MDA and TAC was similar between blood and saliva. There was significant correlation between blood and saliva with respect to MDA and TAC in oral cancer patients. Oral cancer patients showed increased oxidative stress and impaired antioxidant capacity. After radiation therapy of one week, oxidative stress increased further, and after six weeks of radiation therapy there was amelioration of antioxidant status. Saliva could be a sensitive and convenient laboratory tool for diagnosis of oral cancer and evaluation of biological effects of radiation therapy. (author)

  1. Influenza A Virus Hemagglutinin is Required for the Assembly of Viral Components Including Bundled vRNPs at the Lipid Raft

    Directory of Open Access Journals (Sweden)

    Naoki Takizawa

    2016-09-01

    Full Text Available The influenza glycoproteins, hemagglutinin (HA and neuraminidase (NA, which are associated with the lipid raft, have the potential to initiate virion budding. However, the role of these viral proteins in infectious virion assembly is still unclear. In addition, it is not known how the viral ribonucleoprotein complex (vRNP is tethered to the budding site. Here, we show that HA is necessary for the efficient progeny virion production and vRNP packaging in the virion. We also found that the level of HA does not affect the bundling of the eight vRNP segments, despite reduced virion production. Detergent solubilization and a subsequent membrane flotation analysis indicated that the accumulation of nucleoprotein, viral polymerases, NA, and matrix protein 1 (M1 in the lipid raft fraction was delayed without HA. Based on our results, we inferred that HA plays a role in the accumulation of viral components, including bundled vRNPs, at the lipid raft.

  2. Influenza A Virus Hemagglutinin is Required for the Assembly of Viral Components Including Bundled vRNPs at the Lipid Raft.

    Science.gov (United States)

    Takizawa, Naoki; Momose, Fumitaka; Morikawa, Yuko; Nomoto, Akio

    2016-09-10

    The influenza glycoproteins, hemagglutinin (HA) and neuraminidase (NA), which are associated with the lipid raft, have the potential to initiate virion budding. However, the role of these viral proteins in infectious virion assembly is still unclear. In addition, it is not known how the viral ribonucleoprotein complex (vRNP) is tethered to the budding site. Here, we show that HA is necessary for the efficient progeny virion production and vRNP packaging in the virion. We also found that the level of HA does not affect the bundling of the eight vRNP segments, despite reduced virion production. Detergent solubilization and a subsequent membrane flotation analysis indicated that the accumulation of nucleoprotein, viral polymerases, NA, and matrix protein 1 (M1) in the lipid raft fraction was delayed without HA. Based on our results, we inferred that HA plays a role in the accumulation of viral components, including bundled vRNPs, at the lipid raft.

  3. The amino terminal end determines the stability and assembling capacity of eukaryotic ribosomal stalk proteins P1 and P2.

    Science.gov (United States)

    Camargo, Hendricka; Nusspaumer, Gretel; Abia, David; Briceño, Verónica; Remacha, Miguel; Ballesta, Juan P G

    2011-05-01

    The eukaryotic ribosomal proteins P1 and P2 bind to protein P0 through their N-terminal domain to form the essential ribosomal stalk. A mutational analysis points to amino acids at positions 2 and 3 as determinants for the drastic difference of Saccharomyces cerevisiae P1 and P2 half-life, and suggest different degradation mechanisms for each protein type. Moreover, the capacity to form P1/P2 heterodimers is drastically affected by mutations in the P2β four initial amino acids, while these mutations have no effect on P1β. Binding of P2β and, to a lesser extent, P1β to the ribosome is also seriously affected showing the high relevance of the amino acids in the first turn of the NTD α-helix 1 for the stalk assembly. The negative effect of some mutations on ribosome binding can be reversed by the presence of the second P1/P2 couple in the ribosome, indicating a stabilizing structural influence between the two heterodimers. Unexpectedly, some mutations totally abolish heterodimer formation but allow significant ribosome binding and, therefore, a previous P1 and P2 association seems not to be an absolute requirement for stalk assembly. Homology modeling of the protein complexes suggests that the mutated residues can affect the overall protein conformation. © The Author(s) 2011. Published by Oxford University Press.

  4. Effect of Solvent System on Extractability of Lipidic Components of Scenedesmus obliquus (M2-1) and Gloeothece sp. on Antioxidant Scavenging Capacity Thereof

    Science.gov (United States)

    Amaro, Helena M.; Fernandes, Fátima; Valentão, Patrícia; Andrade, Paula B.; Sousa-Pinto, I.; Malcata, F. Xavier; Guedes, A. Catarina

    2015-01-01

    Microalgae are well known for their biotechnological potential, namely with regard to bioactive lipidic components—especially carotenoids and polyunsaturated fatty acids (PUFA), well-known for therapeutic applications based on their antioxidant capacity. The aim of this work was to evaluate the influence of four distinct food-grade solvents upon extractability of specific lipidic components, and on the antioxidant capacity exhibited against both synthetic (2,2-diphenyl-1-picrylhydrazyl (DPPH•) and 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS+•)) and biological reactive species (O2•− and •NO−). A eukaryotic microalga (Scenedesmus obliquus (M2-1)) and a prokaryotic one (Gloeothece sp.) were used as case studies. Concerning total antioxidant capacity, the hexane:isopropanol (3:2) and acetone extracts of Sc. obliquus (M2-1) were the most effective against DPPH• and ABTS+•, respectively. Gloeothece sp. ethanol extracts were the most interesting scavengers of O2•−, probably due the high content of linolenic acid. On the other hand, acetone and hexane:isopropanol (3:2) extracts were the most interesting ones in •NO− assay. Acetone extract exhibited the best results for the ABTS assay, likely associated to its content of carotenoids, in both microalgae. Otherwise, ethanol stood out in PUFA extraction. Therefore, profiles of lipidic components extracted are critical for evaluating the antioxidant performance—which appears to hinge, in particular, on the balance between carotenoids and PUFAs. PMID:26492257

  5. Effect of Solvent System on Extractability of Lipidic Components of Scenedesmus obliquus (M2-1 and Gloeothece sp. on Antioxidant Scavenging Capacity Thereof

    Directory of Open Access Journals (Sweden)

    Helena M. Amaro

    2015-10-01

    Full Text Available Microalgae are well known for their biotechnological potential, namely with regard to bioactive lipidic components—especially carotenoids and polyunsaturated fatty acids (PUFA, well-known for therapeutic applications based on their antioxidant capacity. The aim of this work was to evaluate the influence of four distinct food-grade solvents upon extractability of specific lipidic components, and on the antioxidant capacity exhibited against both synthetic (2,2-diphenyl-1-picrylhydrazyl (DPPH• and 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS+• and biological reactive species (O2•- and •NO-. A eukaryotic microalga (Scenedesmus obliquus (M2-1 and a prokaryotic one (Gloeothece sp. were used as case studies. Concerning total antioxidant capacity, the hexane:isopropanol (3:2 and acetone extracts of Sc. obliquus (M2-1 were the most effective against DPPH• and ABTS+•, respectively. Gloeothece sp. ethanol extracts were the most interesting scavengers of O2•-, probably due the high content of linolenic acid. On the other hand, acetone and hexane:isopropanol (3:2 extracts were the most interesting ones in •NO- assay. Acetone extract exhibited the best results for the ABTS assay, likely associated to its content of carotenoids, in both microalgae. Otherwise, ethanol stood out in PUFA extraction. Therefore, profiles of lipidic components extracted are critical for evaluating the antioxidant performance—which appears to hinge, in particular, on the balance between carotenoids and PUFAs.

  6. Amphiphilic lipid derivatives of 3'-hydroxyurea-deoxythymidine: preparation, properties, molecular self-assembly, simulation and in vitro anticancer activity.

    Science.gov (United States)

    Li, Miao; Qi, Shuo; Jin, Yiguang; Yao, Weishang; Zhang, Sa; Zhao, Jingyu

    2014-11-01

    Lipid derivatives of nucleoside analogs and their nanoassemblies have become the research hotspot due to their unique function in cancer therapy. Six lipid derivatives of 3'-hydroxyurea-deoxythymidine were prepared with zidovudine as the raw material. The 5'-substituted lipid chains in the derivatives were from the various fatty acids including octanoic acid, decanoic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid and octadecanoic acid corresponding to the derivatives OHT, DHT, DDHT, TDHT, HDHT and ODHT. The amphiphilic derivatives formed Langmuir monolayers at the air/water interface with different surface pressure-molecular area isotherms depending on the length of lipid chains. The nanoassemblies of OHT, DHT, DDHT, TDHT and HDHT and the nanoscale precipitates of ODHT were obtained after we injected their tetrahydrofuran solutions doped with hydrophilic long chained polymers into water. Electron microscopy showed that the morphology of nanoassemblies may be vesicles or nanotubes depending on the length of lipid chains. The shorter the lipid chains were, the softer the nanoassemblies. Computer simulation supported the experimental results. The nanoassemblies and the nanoscale precipitates showed much higher anticancer effects on SW620 cells than the parent drug hydroxyurea. The nanostructures of the derivatives are promising anticancer nanomedicines. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Contemporary and prospective fuel cycles for WWER-440 based on new assemblies with higher uranium capacity and higher average fuel enrichment

    International Nuclear Information System (INIS)

    Gagarinskiy, A.A.; Saprykin, V.V.

    2009-01-01

    RRC 'Kurchatov Institute' has performed an extensive cycle of calculations intended to validate the opportunities of improving different fuel cycles for WWER-440 reactors. Works were performed to upgrade and improve WWER-440 fuel cycles on the basis of second-generation fuel assemblies allowing core thermal power to be uprated to 107 108 % of its nominal value (1375 MW), while maintaining the same fuel operation lifetime. Currently intensive work is underway to develop fuel cycles based on second-generation assemblies with higher fuel capacity and average fuel enrichment per assembly increased up to 4.87 % of U-235. Fuel capacity of second-generation assemblies was increased by means of eliminated central apertures of fuel pellets, and pellet diameter extended due to reduced fuel cladding thickness. This paper intends to summarize the results of works performed in the field of WWER-440 fuel cycle modernization, and to present yet unemployed opportunities and prospects of further improvement of WWER-440 neutronic and operating parameters by means of additional optimization of fuel assembly designs and fuel element arrangements applied. (Authors)

  8. Effect of Pistacia Atlantica Extract on Glutathione Peroxidase Tissue Levels and Total Oxidative Capacity of Liver and Plasma Lipid Profile of Rats

    Directory of Open Access Journals (Sweden)

    Parvin Farzanegi

    2013-11-01

    Full Text Available Background: Exercise causes increased oxygen consumption, leaving cells exposed to oxidative stress. Antioxidants may have a protective effect by inhibiting lipid peroxidation. Thus, this study aims to examine the effect of Pistacia atlantica extract on glutathione peroxidase levels and total oxidative capacity of liver and plasma lipid profile of rats. Materials and Methods: In this experimental study, 28 female rats’ weight 155.8±2.7 grams were randomly and equally divided into 4 groups of exercise-saline, control-saline, exercise-mastic, and control-mastic. The exercise groups exercised for 8 weeks (5 days per week, 60 minutes daily, 25 meters per minute, on a zero degree slope. The rats received equal volumes of mastic and saline orally for 4 weeks. Blood and tissue samples were taken 72 hours after the last exercise session. Data were analyzed using one-way variance analysis (ANOVA.Results: Consumption of Pistacia atlantica extract together with endurance exercising for 8 weeks did not significantly affect glutathione peroxidase concentration, total oxidative capacity, LDL, triglyceride, or cholesterol, but significantly reduced HDL (p=0.002.Conclusion: Results showed that antioxidant and lipid profile levels were not affected by consumption of supplements and endurance exercising. However, further studies are required to assess the long term effects of this herbal extract.

  9. The effect of melanin-free extract from Sepia esculenta ink on lipid peroxidation, protein oxidation and water-holding capacity of tilapia fillet during cold storage.

    Science.gov (United States)

    Duan, Zhen-Hua; Liu, Hua-Zhong; Luo, Ping; Gu, Yi-Peng; Li, Yan-Qun

    2018-03-14

    Preservative effect of melanin-free extract of Sepia esculenta ink (MFESI) on Sparus latus fillet has been verified in our previous work. This study aims to further approach the mechanism of MFESI for extending the shelf-life of fish fillet during cold storage. Tilapia fillets were treated with different dosage of MFESI (0, 15, 25 and 35 mg/ml) and packed with preservative film for succedent cold-storage at 4 °C for scheduled time. Contents of total volatile basic nitrogen and sulfydryl and carbanyl groups were measured for evaluating protein oxidation. Malondialdehyde contents were measured for estimating lipid peroxidation and loss of water was used to determine water-holding capacity of fillet. The data indicated that MFESI not only possessed certain degree of antioxidant capacity in vitro, also lengthened shelf-life of tilapia fillet in cold-storage condition. Apart from 15 mg/ml, both 25 and 35 mg/ml of MFESI obviously prevented lipid and protein from oxidation and reduced loss of water from tilapia fillets, and the latter was more effective than the former. MFESI can repress lipid peroxidation and protein oxidation and reduce water loss, maintain the tilapia fillets quality and, thus, it could be an effective and natural preservative for extending the shelf-life of tilapia fillets during cold storage.

  10. Sodium phenylbutyrate, a drug with known capacity to reduce endoplasmic reticulum stress, partially alleviates lipid-induced insulin resistance and beta-cell dysfunction in humans.

    Science.gov (United States)

    Xiao, Changting; Giacca, Adria; Lewis, Gary F

    2011-03-01

    Chronically elevated free fatty acids contribute to insulin resistance and pancreatic β-cell failure. Among numerous potential factors, the involvement of endoplasmic reticulum (ER) stress has been postulated to play a mechanistic role. Here we examined the efficacy of the chemical chaperone, sodium phenylbutyrate (PBA), a drug with known capacity to reduce ER stress in animal models and in vitro, on lipid-induced insulin resistance and β-cell dysfunction in humans. Eight overweight or obese nondiabetic men underwent four studies each, in random order, 4 to 6 weeks apart. Two studies were preceded by 2 weeks of oral PBA (7.5 g/day), followed by a 48-h i.v. infusion of intralipid/heparin or saline, and two studies were preceded by placebo treatment, followed by similar infusions. Insulin secretion rates (ISRs) and sensitivity (S(I)) were assessed after the 48-h infusions by hyperglycemic and hyperinsulinemic-euglycemic clamps, respectively. Lipid infusion reduced S(I), which was significantly ameliorated by pretreatment with PBA. Absolute ISR was not affected by any treatment; however, PBA partially ameliorated the lipid-induced reduction in the disposition index (DI = ISR × S(I)), indicating that PBA prevented lipid-induced β-cell dysfunction. These results suggest that PBA may provide benefits in humans by ameliorating the insulin resistance and β-cell dysfunction induced by prolonged elevation of free fatty acids.

  11. Equation of State for Phospholipid Self-Assembly

    DEFF Research Database (Denmark)

    Marsh, Derek

    2016-01-01

    Phospholipid self-assembly is the basis of biomembrane stability. The entropy of transfer from water to self-assembled micelles of lysophosphatidylcholines and diacyl phosphatidylcholines with different chain lengths converges to a common value at a temperature of 44°C. The corresponding enthalpies...... of transfer converge at ∼-18°C. An equation of state for the free energy of self-assembly formulated from this thermodynamic data depends on the heat capacity of transfer as the sole parameter needed to specify a particular lipid. For lipids lacking calorimetric data, measurement of the critical micelle...

  12. Core hydrophobicity tuning of a self-assembled particle results in efficient lipid reduction and favorable organ distribution.

    Science.gov (United States)

    Banik, Bhabatosh; Wen, Ru; Marrache, Sean; Kumar, Anil; Kolishetti, Nagesh; Howerth, Elizabeth W; Dhar, Shanta

    2017-12-21

    Atherosclerosis, the deadliest disease in the United States, arises due to the build up of plaques in the arteries as a result of excessive cholesterol deposition and an impaired cholesterol removal process. High density lipoproteins (HDL), popularly known as "good cholesterol", are naturally occurring nano-sized particles that, along with apolipoproteins, are deployed to maintain cholesterol homeostasis in the body. Both cholesterol efflux, from the fat-laden macrophages in the arteries, and intracellular lipid transport, to deliver cholesterol to the mitochondria of liver cells for metabolism, hold key responsibilities to maintain healthy lipid levels inside the body. We designed a library of nine mitochondria targeted polymer-lipid hybrid nanoparticles (NPs), comprised of completely synthetic yet biodegradable components, that are capable of performing HDL-like functions. Using this library, we optimized a superior mitochondria targeted NP candidate, which can show favourable organ distribution, therapeutic potential, and non-toxic properties. Two targeted NP formulations with optimum NP size, zeta potential, and cholesterol binding and release properties were identified. Lipid reduction and anti-oxidative properties of these two NPs demonstrated cholesterol removal ability. In vivo therapeutic evaluation of the targeted-NP formulations in apolipoprotein E knockout (apoE - / - ) mice indicated lipid reduction and anti-inflammatory properties compared to non-targeted NPs. This synthetic targeted NP with potential abilities to participate in both extra- and intracellular cholesterol transport might potentiate therapeutic interventions for heart diseases.

  13. Surface coating of siRNA-peptidomimetic nano-self-assemblies with anionic lipid bilayers: enhanced gene silencing and reduced adverse effects in vitro

    Science.gov (United States)

    Zeng, Xianghui; de Groot, Anne Marit; Sijts, Alice J. A. M.; Broere, Femke; Oude Blenke, Erik; Colombo, Stefano; van Eden, Willem; Franzyk, Henrik; Nielsen, Hanne Mørck; Foged, Camilla

    2015-11-01

    Cationic vectors have demonstrated the potential to facilitate intracellular delivery of therapeutic oligonucleotides. However, enhanced transfection efficiency is usually associated with adverse effects, which also proves to be a challenge for vectors based on cationic peptides. In this study a series of proteolytically stable palmitoylated α-peptide/β-peptoid peptidomimetics with a systematically varied number of repeating lysine and homoarginine residues was shown to self-assemble with small interfering RNA (siRNA). The resulting well-defined nanocomplexes were coated with anionic lipids giving rise to net anionic liposomes. These complexes and the corresponding liposomes were optimized towards efficient gene silencing and low adverse effects. The optimal anionic liposomes mediated a high silencing effect, which was comparable to that of the control (cationic Lipofectamine 2000), and did not display any noticeable cytotoxicity and immunogenicity in vitro. In contrast, the corresponding nanocomplexes mediated a reduced silencing effect with a more narrow safety window. The surface coating with anionic lipid bilayers led to partial decomplexation of the siRNA-peptidomimetic nanocomplex core of the liposomes, which facilitated siRNA release. Additionally, the optimal anionic liposomes showed efficient intracellular uptake and endosomal escape. Therefore, these findings suggest that a more efficacious and safe formulation can be achieved by surface coating of the siRNA-peptidomimetic nano-self-assemblies with anionic lipid bilayers.Cationic vectors have demonstrated the potential to facilitate intracellular delivery of therapeutic oligonucleotides. However, enhanced transfection efficiency is usually associated with adverse effects, which also proves to be a challenge for vectors based on cationic peptides. In this study a series of proteolytically stable palmitoylated α-peptide/β-peptoid peptidomimetics with a systematically varied number of repeating lysine

  14. Dietary exposure to shiitake mushroom confers reductions in serum glucose, lipids, leptin and antioxidant capacity in rats

    Science.gov (United States)

    Previously, we showed that dietary intake of shiitake mushroom (Lentinus edodes) decreased serum levels of polar lipids in rats. This study evaluated the effects of lifelong consumption of shiitake on body composition and serum cholesterol-related- and anti-oxidant indices in rats. Rat dams and th...

  15. Convenient synthesis and application of versatile nucleic acid lipid membrane anchors in the assembly and fusion of liposomes

    DEFF Research Database (Denmark)

    Ries, Oliver; Löffler, Philipp M. G.; Vogel, Stefan

    2015-01-01

    or the construction of DNA origami structures. We herein present the synthesis and applications of versatile lipid membrane anchor building blocks suitable for solid phase oligonucleotide synthesis. These are readily synthesized in bulk in five to seven steps from commercially available precursors and can...

  16. On the lipid head group hydration of floating surface monolayers bound to self-assembled molecular protein layers

    DEFF Research Database (Denmark)

    Lösche, M.; Erdelen, C.; Rump, E.

    1994-01-01

    kept at low surface pressure before protein adsorption. The introduction of dipole moments at the interface by the admixture of phospholipids or the application of lateral pressure on the lipid monolayer before protein adsorption were found to impose an extension of the spacer moieties. The biotin...

  17. Electrostatic Self-Assembly of Fe3O4 Nanoparticles on Graphene Oxides for High Capacity Lithium-Ion Battery Anodes

    Directory of Open Access Journals (Sweden)

    Jung Kyoo Lee

    2013-09-01

    Full Text Available Magnetite, Fe3O4, is a promising anode material for lithium ion batteries due to its high theoretical capacity (924 mA h g−1, high density, low cost and low toxicity. However, its application as high capacity anodes is still hampered by poor cycling performance. To stabilize the cycling performance of Fe3O4 nanoparticles, composites comprising Fe3O4 nanoparticles and graphene sheets (GS were fabricated. The Fe3O4/GS composite disks of mm dimensions were prepared by electrostatic self-assembly between negatively charged graphene oxide (GO sheets and positively charged Fe3O4-APTMS [Fe3O4 grafted with (3-aminopropyltrimethoxysilane (APTMS] in an acidic solution (pH = 2 followed by in situ chemical reduction. Thus prepared Fe3O4/GS composite showed an excellent rate capability as well as much enhanced cycling stability compared with Fe3O4 electrode. The superior electrochemical responses of Fe3O4/GS composite disks assure the advantages of: (1 electrostatic self-assembly between high storage-capacity materials with GO; and (2 incorporation of GS in the Fe3O4/GS composite for high capacity lithium-ion battery application.

  18. Co-assembly of Peptide Amphiphiles and Lipids into Supramolecular Nanostructures Driven by Anion-π Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Zhilin; Erbas, Aykut; Tantakitti, Faifan; Palmer, Liam C.; Jackman, Joshua A.; Olvera de la Cruz, Monica; Cho, Nam-Joon; Stupp, Samuel I. (Nanyang); (NWU)

    2017-06-01

    Co-assembly of binary systems driven by specific non-covalent interactions can greatly expand the structural and functional space of supramolecular nanostructures. We report here on the self-assembly of peptide amphiphiles and fatty acids driven primarily by anion-π interactions. The peptide sequences investigated were functionalized with a perfluorinated phenylalanine residue to promote anion-π interactions with carboxylate headgroups in fatty acids. These interactions were verified here by NMR and circular dichroism experiments as well as investigated using atomistic simulations. Positioning the aromatic units close to the N-terminus of the peptide backbone near the hydrophobic core of cylindrical nanofibers leads to strong anion-π interactions between both components. With a low content of dodecanoic acid in this position, the cylindrical morphology is preserved. However, as the aromatic units are moved along the peptide backbone away from the hydrophobic core, the interactions with dodecanoic acid transform the cylindrical supramolecular morphology into ribbon-like structures. Increasing the ratio of dodecanoic acid to PA leads to either the formation of large vesicles in the binary systems where the anion-π interactions are strong, or a heterogeneous mixture of assemblies when the peptide amphiphiles associate weakly with dodecanoic acid. Our findings reveal how co-assembly involving designed specific interactions can drastically change supramolecular morphology and even cross from nano to micro scales.

  19. Impact of vitamin E and selenium on antioxidant capacity and lipid oxidation of cheddar cheese in accelerated ripening.

    Science.gov (United States)

    Batool, Maryam; Nadeem, Muhammad; Imran, Muhammad; Gulzar, Nabila; Shahid, Muhammad Qamar; Shahbaz, Muhammad; Ajmal, Muhammad; Khan, Imran Taj

    2018-04-11

    Ripening of cheddar cheese is a time taking process, duration of the ripening may be as long as one year. Long ripening time is a big hindrance in the popularity of cheese in developing countries. Further, energy resources in these countries are either insufficient or very expensive. Therefore, those methods of cheese ripening should be discovered which can significantly reduce the ripening time without compromising the quality characteristics of cheddar cheese. In accelerated ripening, cheese is usually ripened at higher temperature than traditional ripening temperatures. Ripening of cheddar cheese at high temperature with the addition of vitamin E and selenium is not previously studied. This investigation aimed to study the antioxidant activity of selenium and vitamin E in accelerated ripening using cheddar cheese as an oxidation substrate. The ripening of cheddar cheese was performed at 18 °C and to prevent lipid oxidation, vitamin E and selenium were used alone and in combination. The treatments were as: cheddar cheese without any addition of vitamin E and selenium (T1), cheddar cheese added with 100 mg/kg vitamin E (T 2 ), 200 mg/kg vitamin E (T 3 ), 800 μg/kg selenium (T 4 ), 1200 μg/kg selenium (T 5 ), vitamin E 100 mg/kg + 800 μg/kg selenium (T 6 ) and vitamin E 200 mg/kg + 1200 μg/kg selenium (T 7 ). Traditional cheddar cheese ripne ripened at 4-6 °C for 9 months was used as positive control. Cheese samples were ripened at 18 °C for a period of 12 weeks and analyzed for chemical and oxidative stability characteristics at 0, 6 and 12 weeks of storage. All these treatments were compared with a cheddar cheese without vitamin E, selenium and ripened at 4 °C or 12 weeks. Vacuum packaged cheddar cheese was ripened 18 °C for a period of 12 weeks and analyzed for chemical and oxidative stability characteristics at 0, 4 and 8 weeks of storage period. Addition of Vitamin E and selenium did not have any effect on moisture, fat and

  20. Effects of aerobic interval training versus continuous moderate exercise programme on aerobic and anaerobic capacity, somatic features and blood lipid profile in collegate females

    Directory of Open Access Journals (Sweden)

    Krzystof Mazurek

    2014-11-01

    Full Text Available introduction. Regular physical activity has many positive health benefits, including reducing the risk of cardiovascular diseases, metabolic diseases and some cancers, as well as improving the quality of life. objectives. The aim of the study was to examine the effects of 8-week aerobic interval cycle exercise training (AIT compared to continuous cycle exercises of moderate intensity (CME on the aerobic and anaerobic capacity, somatic features and lipid profile. material and methods. The research was conducted in 88 volunteers aged 19.5±0.6 years, who were randomized to three groups of organized physical activity (OPA, who exercised 3 times per week in 47 min sessions: (I AIT (n=24 comprising 2 series of 6x10 s sprinting with maximal pedalling cadence and active rest pedalling with intensity 65%–75% HRmax, (II CME (n=22 corresponding to 65%-75% HRmax, (III regular collegiate physical education classes of programmed exercises (CON; n=42. Before and after OPA anthropometrics, aero- and anaerobic capacity and lipid profile indices were measured. results. In AIT, a significantly greater decrease of waist circumference and WHR was noted when compared to CON, and a significantly greater reduction of sum of skinfolds than in CON and CME. Improvement in relative and absolute VO2max (L/min and ml/kg/min was significantly higher in AIT than CON. Work output and peak power output in the anaerobic test improved significantly in AIT, CME and CON, but independently of training type. OPA was effective only in reducing triglyceride concentrations in CME and CON groups, without interaction effects in relation to training type. conclusion. It was found that 8 weeks of OPA was beneficial in improving somatic and aerobic capacity indices, but AIT resulted in the greatest improvement in somatic indices (waist circumference, WHR, sum of skinfolds and in VO[sub]2[/sub]max, compared to CME and CON programmes.

  1. Dry powder inhaler formulation of lipid-polymer hybrid nanoparticles via electrostatically-driven nanoparticle assembly onto microscale carrier particles.

    Science.gov (United States)

    Yang, Yue; Cheow, Wean Sin; Hadinoto, Kunn

    2012-09-15

    Lipid-polymer hybrid nanoparticles have emerged as promising nanoscale carriers of therapeutics as they combine the attractive characteristics of liposomes and polymers. Herein we develop dry powder inhaler (DPI) formulation of hybrid nanoparticles composed of poly(lactic-co-glycolic acid) and soybean lecithin as the polymer and lipid constituents, respectively. The hybrid nanoparticles are transformed into inhalable microscale nanocomposite structures by a novel technique based on electrostatically-driven adsorption of nanoparticles onto polysaccharide carrier particles, which eliminates the drawbacks of conventional techniques based on controlled drying (e.g. nanoparticle-specific formulation, low yield). First, we engineer polysaccharide carrier particles made up of chitosan cross-linked with tripolyphosphate and dextran sulphate to exhibit the desired aerosolization characteristics and physical robustness. Second, we investigate the effects of nanoparticle to carrier mass ratio and salt inclusion on the adsorption efficiency, in terms of the nanoparticle loading and yield, from which the optimal formulation is determined. Desorption of the nanoparticles from the carrier particles in phosphate buffer saline is also examined. Lastly, we characterize aerosolization efficiency of the nanocomposite product in vitro, where the emitted dose and respirable fraction are found to be comparable to the values of conventional DPI formulations. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Dual-layered nanogel-coated hollow lipid/polypeptide conjugate assemblies for potential pH-triggered intracellular drug release.

    Directory of Open Access Journals (Sweden)

    Wen-Hsuan Chiang

    Full Text Available To achieve effective intracellular anticancer drug delivery, the polymeric vesicles supplemented with the pH-responsive outlayered gels as a delivery system of doxorubicin (DOX were developed from self-assembly of the lipid/polypeptide adduct, distearin grafted poly(γ-glutamic acid (poly(γ-GA, followed by sequential deposition of chitosan and poly(γ-GA-co-γ-glutamyl oxysuccinimide-g-monomethoxy poly(ethylene glycol in combination with in situ covalent cross-linking on assembly surfaces. The resultant gel-caged polymeric vesicles (GCPVs showed superior performance in regulating drug release in response to the external pH change. Under typical physiological conditions (pH 7.4 and 37 °C at which the γ-GA/DOX ionic pairings remained mostly undisturbed, the dense outlayered gels of GCPVs significantly reduced the premature leakage of the uncomplexed payload. With the environmental pH being reduced from pH 7.4 to 4.7, the drug liberation was appreciably promoted by the massive disruption of the ionic γ-GA/DOX complexes along with the significant swelling of nanogel layers upon the increased protonation of chitosan chain segments. After being internalized by HeLa cells via endocytosis, GCPVs exhibited cytotoxic effect comparable to free DOX achieved by rapidly releasing the payload in intracellular acidic endosomes and lysosomes. This strongly implies the great promise of such unique GCPVs as an intracellular drug delivery carrier for potential anticancer treatment.

  3. Characterization of lipids and antioxidant capacity of novel nutraceutical egg products developed with omega-3-rich oils.

    Science.gov (United States)

    Kassis, Nissan M; Gigliotti, Joseph C; Beamer, Sarah K; Tou, Janet C; Jaczynski, Jacek

    2012-01-15

    Cardiovascular disease has had an unquestioned status of the number one cause of death in the US since 1921. Omega-3 polyunsaturated fatty acids (ω-3 PUFAs) have cardio-protective benefits. However, egg is typically a poor source of ω-3 PUFAs and, in general, the American diet is low in these cardio-protective fatty acids. Novel, nutritionally enhanced egg products were developed by substituting yolk with ω-3 PUFA-rich flaxseed, menhaden, algae, or krill oil. Experimental egg products matched composition of hen egg (whole egg). The experimental egg products, mixed whole egg, and a liquid egg product (Egg Beaters) were microwave-cooked and compared. Although fat, protein, and moisture contents of experimental egg products matched (P > 0.05) mixed whole egg, experimental egg products had more (P egg. Triglycerides were the main lipid class in all experimental egg products except those developed with krill oil, which had even more phospholipids than mixed whole egg. Analysis of thiobarbituric acid reactive substances showed that lipid oxidation of experimental egg products was lower (P 0.05) to mixed whole egg, except for experimental egg products with krill oil. However, peroxide value showed that all egg samples had minimal oxidation. Experimental egg products developed with menhaden or flaxseed oil had the highest (P egg samples. However, experimental egg products with krill oil likely contained a natural antioxidant, astaxanthin. This study demonstrated an alternative approach to developing novel, nutraceutical egg products. Instead of dietary modification of chicken feed, yolk substitution with ω-3 PUFAs oils resulted in enhancement of ω-3 PUFAs beyond levels possible to achieve by modifying chicken feed. Copyright © 2011 Society of Chemical Industry.

  4. Effect of thyme extract supplementation on lipid peroxidation, antioxidant capacity, PGC-1α content and endurance exercise performance in rats.

    Science.gov (United States)

    Khani, Mostafa; Motamedi, Pezhman; Dehkhoda, Mohammad Reza; Dabagh Nikukheslat, Saeed; Karimi, Pouran

    2017-01-01

    Athletes have a large extent of oxidant agent production. In the current study, we aimed to determine the influence of thyme extract on the endurance exercise performance, mitochondrial biogenesis, and antioxidant status in rats. Twenty male Wistar rats were randomly divided into two groups receiving either normal drinking water (non-supplemented group, n  = 10) or thyme extract, 400 mg/kg, (supplemented group, n  = 10). Rats in both groups were subjected to endurance treadmill training (27 m/min, 10% grade, 60 min, and 5 days/week for 8 weeks). Finally, to determine the endurance capacity, time to exhaustion treadmill running at 36 m/min speed was assessed. At the end of the endurance capacity test, serum and soleus muscle samples were collected and their superoxide dismutase (SOD) and glutathione peroxidase (GPx) activity, as well as malondialdehyde (MDA) concentration were measured. Protein expression of PGC-1α, as a marker of mitochondrial biogenesis, was also determined in the soleus muscle tissue by immunoblotting assay. Findings revealed that the exhaustive running time in the treatment group was significantly ( p  extract supplemented group (t 18  = 8.11, p  antioxidant capacity between groups. Furthermore, thyme supplementation significantly ( p  extract supplementation increased endurance exercise tolerance in intact animals, although decrease of oxidative stress and regulation of the PGC-1α protein expression are not considered as underlying molecular mechanisms.

  5. Effects of supplementation with acai ( Euterpe oleracea Mart. berry-based juice blend on the blood antioxidant defence capacity and lipid profile in junior hurdlers. A pilot study

    Directory of Open Access Journals (Sweden)

    E Sadowska-Krępa

    2015-05-01

    Full Text Available The purpose of this pilot study was to examine whether regular consumption of an acai berry-based juice blend would affect sprint performance and improve blood antioxidant status and lipid profile in junior athletes. Seven junior hurdlers (17.5±1.2 years taking part in a pre-season conditioning camp were supplemented once a day, for six weeks, with 100 ml of the juice blend. At the start and the end of the camp the athletes performed a 300-m sprint running test on an outdoor track. Blood samples were taken before and immediately after the test and after 1 h of recovery. Blood antioxidant status was evaluated based on activities of antioxidant enzymes (superoxide dismutase [SOD], catalase [CAT], glutathione peroxidase [GSH-Px], glutathione reductase [GR], concentrations of non-enzymatic antioxidants (reduced glutathione [GSH], uric acid, total plasma polyphenols, ferric reducing ability of plasma (FRAP, thiobarbituric acid reactive substances (TBARS and activities of creatine kinase (CK and lactate dehydrogenase (LDH as muscle damage markers. In order to evaluate potential health benefits of the acai berry, the post-treatment changes in lipid profile parameters (triglycerides, cholesterol and its fractions were analysed. Six weeks’ consumption of acai berry-based juice blend had no effect on sprint performance, but it led to a marked increase in the total antioxidant capacity of plasma, attenuation of the exercise-induced muscle damage, and a substantial improvement of serum lipid profile. These findings strongly support the view of the health benefits of supplementation with the acai berry-based juice blend, mainly attributed to its high total polyphenol content and the related high in vivo antioxidant and hypocholesterolaemic activities of this supplement.

  6. The Effect of Colostrum along with Aerobic and Anaerobic Exercise on Lipid Peroxidation and Total Antioxidant Capacity of Male Wistar Rats

    Directory of Open Access Journals (Sweden)

    M Mogharnasi

    2016-06-01

    Full Text Available Background & aim: The consumption of food supplements in order to eliminate oxidative damages induced by exercise are common among athletes. Previous studies have shown that bovine colostrum has antioxidant properties, but no study has ever been done to evaluate its effectiveness on Oxidative stress and antioxidant capacity. The aim of study was to investigate the effects of bovine colostrum along with aerobic and anaerobic exercise on Lipid peroxidation and antioxidant capacity in male Wistar rats.   Methods: In the present experimental study, 48 male Wistar rats were randomly divided into six groups (control, colostrum supplement, aerobic exercise, anaerobic exercise, colostrum supplements and aerobic exercise, colostrum supplements and anaerobic exercise. Colostrum group received daily for ten weeks dosing 300 mg /kg bovine colostrum powder orally. Exercising groups worked out three times a week for a period of 10 weeks on a custom-made treadmill for rodents. Blood samples were taken before and 24 hours after the last exercise session on an empty stomach. Data were analyzed using Kolmogorov-Smirnov tests, One Way ANOVA and post hoc Tukey at α<0.05.   Results: The plasma levels of oxidative stress index (MDA in all groups except colostrum supplement and anaerobic exercise compared with the control group was significantly reduced (p<0.05. The antioxidant capacity in all groups except anaerobic exercise group compared with the control group was significant increased (p<0.05.   Conclusions: The results indicated that colostrum supplementation with ten weeks of aerobic exercise had better effect on the control of oxidative stress and antioxidant capacity compared to anaerobic exercise.    

  7. Surface-enhanced Raman scattering of self-assembled thiol monolayers and supported lipid membranes on thin anodic porous alumina

    Directory of Open Access Journals (Sweden)

    Marco Salerno

    2017-01-01

    Full Text Available Thin anodic porous alumina (tAPA was fabricated from a 500 nm thick aluminum (Al layer coated on silicon wafers, through single-step anodization performed in a Teflon electrochemical cell in 0.4 M aqueous phosphoric acid at 110 V. Post-fabrication etching in the same acid allowed obtaining tAPA surfaces with ≈160 nm pore diameter and ≈80 nm corresponding wall thickness to be prepared. The tAPA surfaces were made SERS-active by coating with a thin (≈25 nm gold (Au layer. The as obtained tAPA–Au substrates were incubated first with different thiols, namely mercaptobenzoic acid (MbA and aminothiol (AT, and then with phospholipid vesicles of different composition to form a supported lipid bilayer (SLB. At each step, the SERS substrate functionality was assessed, demonstrating acceptable enhancement (≥100×. The chemisorption of thiols during the first step and the formation of SLB from the vesicles during the second step, were independently monitored by using a quartz crystal microbalance with dissipation monitoring (QCM-D technique. The SLB membranes represent a simplified model system of the living cells membranes, which makes the successful observation of SERS on these films promising in view of the use of tAPA–Au substrates as a platform for the development of surface-enhanced Raman spectroscopy (SERS biosensors on living cells. In the future, these tAPA–Au-SLB substrates will be investigated also for drug delivery of bioactive agents from the APA pores.

  8. Self-assembly synthesis of 3D graphene-encapsulated hierarchical Fe3O4 nano-flower architecture with high lithium storage capacity and excellent rate capability

    Science.gov (United States)

    Ma, Yating; Huang, Jian; Lin, Liang; Xie, Qingshui; Yan, Mengyu; Qu, Baihua; Wang, Laisen; Mai, Liqiang; Peng, Dong-Liang

    2017-10-01

    Graphene-encapsulated hierarchical metal oxides architectures can efficiently combine the merits of graphene and hierarchical metal oxides, which are deemed as the potential anode material candidates for the next-generation lithium-ion batteries due to the synergistic effect between them. Herein, a cationic surfactant induced self-assembly method is developed to construct 3D Fe3O4@reduction graphene oxide (H-Fe3O4@RGO) hybrid architecture in which hierarchical Fe3O4 nano-flowers (H-Fe3O4) are intimately encapsulated by 3D graphene network. Each H-Fe3O4 particle is constituted of rod-shaped skeletons surrounded by petal-like nano-flakes that are made up of enormous nanoparticles. When tested as the anode material in lithium-ion batteries, a high reversible capacity of 2270 mA h g-1 after 460 cycles is achieved under a current density of 0.5 A g-1. More impressively, even tested at a large current density of 10 A g-1, a decent reversible capacity of 490 mA h g-1 can be retained, which is still higher than the theoretical capacity of traditional graphite anode, demonstrating the remarkable lithium storage properties. The reasons for the excellent electrochemical performance of H-Fe3O4@RGO electrode have been discussed in detail.

  9. Coffee Consumption Increases the Antioxidant Capacity of Plasma and Has No Effect on the Lipid Profile or Vascular Function in Healthy Adults in a Randomized Controlled Trial.

    Science.gov (United States)

    Agudelo-Ochoa, Gloria M; Pulgarín-Zapata, Isabel C; Velásquez-Rodriguez, Claudia M; Duque-Ramírez, Mauricio; Naranjo-Cano, Mauricio; Quintero-Ortiz, Mónica M; Lara-Guzmán, Oscar J; Muñoz-Durango, Katalina

    2016-03-01

    Coffee, a source of antioxidants, has controversial effects on cardiovascular health. We evaluated the bioavailability of chlorogenic acids (CGAs) in 2 coffees and the effects of their consumption on the plasma antioxidant capacity (AC), the serum lipid profile, and the vascular function in healthy adults. Thirty-eight men and 37 women with a mean ± SD age of 38.5 ± 9 y and body mass index of 24.1 ± 2.6 kg/m(2) were randomly assigned to 3 groups: a control group that did not consume coffee or a placebo and 2 groups that consumed 400 mL coffee/d for 8 wk containing a medium (MCCGA; 420 mg) or high (HCCGA; 780 mg) CGA content. Both were low in diterpenes (0.83 mg/d) and caffeine (193 mg/d). Plasma caffeic and ferulic acid concentrations were measured by GC, and the plasma AC was evaluated with use of the ferric-reducing antioxidant power method. The serum lipid profile, nitric oxide (NO) plasma metabolites, vascular endothelial function (flow-mediated dilation; FMD), and blood pressure (BP) were evaluated. After coffee consumption (1 h and 8 wk), caffeic and ferulic acid concentrations increased in the coffee-drinking groups, although the values of the 2 groups were significantly different (P consumption, the plasma AC in the control group was significantly lower than the baseline value (-2%) and significantly increased in the MCCGA (6%) and HCCGA (5%) groups (P profile, FMD, BP, or NO plasma metabolites. This trial was registered at registroclinico.sld.cu as RPCEC00000168. © 2016 American Society for Nutrition.

  10. Effects of cultivated wild ginseng pharmacopuncture on lowering lipid and oxidative capacity in biochemical and molecular biological study in obese rats

    Directory of Open Access Journals (Sweden)

    Eun Ju Choi

    2006-02-01

    Full Text Available Objectives : This study was carried out to identified the effects of distilled cultivated wild ginseng pharmacopuncture to the obesity. Methods : Cultivated wild ginseng pharmacopuncture was administered on the points of chung-wan(CV12, Ch'ŏnch'u(ST25, and Chok-samni(ST36 on lowering lipid and oxidative capacity in biochemical and molecular biological aspects were investigated in obese rats fed with high fat diet. Results : 1. The contents of plasma β-lipoprotein showed a tendency to decrease in the pharmacopuncture groups compared to the control group. In the pharmacopuncture groups, the values of ST25 and ST36 pharmacopuncture groups showed lower value. 2. The contents of plasma free fatty acids showed a tendency to decrease in pharmacopuncture groups compared to the control group. However, in the pharmacopuncture groups, the values were not significantly different. 3. Plasma triglyceride and glucose showed lower value in the ST25 pharmacopuncture groups compared with the other groups. 4. The activity of AST showed a tendency to decrease in the pharmacopuncture groups. However, the activity of ALT was not significantly different in all the treatment groups. 5. Plasma total cholesterol and LDL-cholesterol showed lower value in the ST25 and ST36 pharmacopuncture groups and HDL-cholesterol showed higher value in the CV12 pharmacopuncture groups than that of the other treatment groups. 6. Liver total cholesterol values didn't show significant difference in all the treatment groups, and triglyceride showed lower value in the pharmacopuncture groups. 7. The contents of plasma TBARS showed lower value in the ST25 pharmacopuncture group and contents of liver TBARS showed a tendency to decrease in the pharmacopuncture groups. However these values didn't show significant difference in the pharmaco puncture groups. 8. Liver super oxide dismutase activity showed higher value in the ST25 and ST36 pharmacopuncture groups, and the value of liver

  11. Effect of sulfite treatment on total antioxidant capacity, total oxidant status, lipid hydroperoxide, and total free sulfydryl groups contents in normal and sulfite oxidase-deficient rat plasma.

    Science.gov (United States)

    Herken, Emine Nur; Kocamaz, Erdogan; Erel, Ozcan; Celik, Hakim; Kucukatay, Vural

    2009-08-01

    Sulfites, which are commonly used as preservatives, are continuously formed in the body during the metabolism of sulfur-containing amino acids. Sulfite oxidase (SOX) is an essential enzyme in the pathway of the oxidative degradation of sulfite to sulfate protecting cells from sulfite toxicity. This article investigated the effect of sulfite on total antioxidant capacity (TAC), total oxidant status, lipid hydroperoxide (LOOH), and total free sulfydryl groups (-SH) levels in normal and SOX-deficient male albino rat plasma. For this purpose, rats were divided into four groups: control, sulfite-treated, SOX-deficient, and sulfite-treated SOX-deficient groups. SOX deficiency was established by feeding rats a low molybdenum diet and adding to their drinking water 200 ppm tungsten. Sulfite (70 mg/kg) was administered to the animals via their drinking water. SOX deficiency together with sulfite treatment caused a significant increase in the plasma LOOH and total oxidant status levels. -SH content of rat plasma significantly decreased by both sulfite treatment and SOX deficiency compared to the control. There was also a significant decrease in plasma TAC level by sulfite treatment. In conclusion, sulfite treatment affects the antioxidant/oxidant balance of the plasma cells of the rats toward oxidants in SOX-deficient groups.

  12. Structure-property relationships in a series of diglycerol tetraether model lipids and their lyotropic assemblies: the effect of branching topology and chirality.

    Science.gov (United States)

    Markowski, Thomas; Drescher, Simon; Meister, Annette; Blume, Alfred; Dobner, Bodo

    2014-06-14

    Three novel diglycerol tetraether lipids with one membrane-spanning chain have been synthesized. These lipids contain only two or four racemic methyl branches at selected positions of the hydrophobic chains in contrast to natural lipids from archaebacterial membranes with an isoprenoid substitution pattern. The insertion of the methyl moieties was realized starting from either (RS)-citronellyl bromide or the inexpensive methyl malonic acid ethyl ester. For chain elongation the Cu-catalysed Grignard coupling reaction was used. The preparation of diglycerol tetraethers was either performed by condensing suitable blocked monoglycerol diethers by Grubbs metathesis or by reaction of the transmembrane C32-chain with blocked glycerols followed by further alkylation steps. Finally, we could show that the resulting lipids can form closed lipid vesicles comparable to the optically pure counterparts. Therefore, these much simpler lipids compared to the natural lipids from archaebacterial membranes are also suitable for preparation of stable tailored liposomes.

  13. [Methodological aspects of evaluation of potential lipid capacity for peroxidation from the serum levels of TBA-active products during iron ion stimulation].

    Science.gov (United States)

    Kulikova, A I; Tugusheva, F A; Zubina, I M; Shepilova, I N

    2008-05-01

    The authors propose a simple and reproducible procedure for using iron ions to stimulate serum lipid peroxidation, with TBA-active products being further determined. The procedure determines the reserve of lipids that can be oxidized during oxidative stress. A combination of direct studies and correlation analysis suggests that low-density lipoproteins and very low-density lipoproteins are the major substrates for lipid peroxidation while high-density lipoproteins show a high resistance to this process. The presented procedure may be used to monitor lipid peroxidation in various conditions and upon various exposures in common laboratory practice.

  14. Supramolecular Langmuir monolayers and multilayered vesicles of self-assembling DNA–lipid surface structures and their further implications in polyelectrolyte-based cell transfections

    Energy Technology Data Exchange (ETDEWEB)

    Demirsoy, Fatma Funda Kaya [Ankara University, The Central Laboratory of The Institute of Biotechnology (Turkey); Eruygur, Nuraniye [Gazi University, Department of Pharmacognosy, Faculty of Pharmacy (Turkey); Süleymanoğlu, Erhan, E-mail: erhans@mail.ru [Gazi University, Department of Pharmaceutical Chemistry, Faculty of Pharmacy (Turkey)

    2015-01-15

    The basic interfacial characteristics of DNA–lipid recognitions have been studied. The complex structures of individual unbound DNA molecules and their binary and ternary complexes with zwitterionic lipids and divalent cations were followed by employing lipid monolayers at the air–liquid interfaces, as well as by performing various microscopic, spectroscopic, and thermodynamic measurements with multilayered vesicles. The pressure-area isotherms depicted that Mg{sup 2+}-ions increase the surface pressure of lipid films and thus give rise to electrostatic and hydrophobic lipid–DNA interactions in terms of DNA adsorption, adhesion, and compaction. These features were further approached by using multilamellar vesicles with a mean diameter of 850 nm, where a metal ion-directed nucleic acid compaction and condensation effects were shown. The data obtained show the effectiveness of Langmuir monolayers and lipid multilayers in studying nucleic acid–lipid recognitions. The data provide with further details and support previous reports on mainly structural features of these recognitions. Biomolecular surface recognition events were presented in direct link with spectral and thermodynamic features of lipid vesicle–polynucleotide complex formations. The results serve to build a theoretical model considering the use of neutral lipids in lipoplex designs as a polyelectrolyte alternatives to the currently employed cytotoxic cationic liposomes. The supramolecular structures formed and their possible roles in interfacial electrostatic and hydrophobic mechanisms of endosomal escape in relevant cell transfection assays are particularly emphasized.

  15. Supramolecular Langmuir monolayers and multilayered vesicles of self-assembling DNA–lipid surface structures and their further implications in polyelectrolyte-based cell transfections

    International Nuclear Information System (INIS)

    Demirsoy, Fatma Funda Kaya; Eruygur, Nuraniye; Süleymanoğlu, Erhan

    2015-01-01

    The basic interfacial characteristics of DNA–lipid recognitions have been studied. The complex structures of individual unbound DNA molecules and their binary and ternary complexes with zwitterionic lipids and divalent cations were followed by employing lipid monolayers at the air–liquid interfaces, as well as by performing various microscopic, spectroscopic, and thermodynamic measurements with multilayered vesicles. The pressure-area isotherms depicted that Mg 2+ -ions increase the surface pressure of lipid films and thus give rise to electrostatic and hydrophobic lipid–DNA interactions in terms of DNA adsorption, adhesion, and compaction. These features were further approached by using multilamellar vesicles with a mean diameter of 850 nm, where a metal ion-directed nucleic acid compaction and condensation effects were shown. The data obtained show the effectiveness of Langmuir monolayers and lipid multilayers in studying nucleic acid–lipid recognitions. The data provide with further details and support previous reports on mainly structural features of these recognitions. Biomolecular surface recognition events were presented in direct link with spectral and thermodynamic features of lipid vesicle–polynucleotide complex formations. The results serve to build a theoretical model considering the use of neutral lipids in lipoplex designs as a polyelectrolyte alternatives to the currently employed cytotoxic cationic liposomes. The supramolecular structures formed and their possible roles in interfacial electrostatic and hydrophobic mechanisms of endosomal escape in relevant cell transfection assays are particularly emphasized

  16. One pot synthesis of GDP-mannose by a multi-enzyme cascade for enzymatic assembly of lipid-linked oligosaccharides.

    Science.gov (United States)

    Rexer, Thomas F T; Schildbach, Anna; Klapproth, Jan; Schierhorn, Angelika; Mahour, Reza; Pietzsch, Markus; Rapp, Erdmann; Reichl, Udo

    2018-01-01

    Glycosylation of proteins is a key function of the biosynthetic-secretory pathway in the endoplasmic reticulum (ER) and Golgi apparatus. Glycosylated proteins play a crucial role in cell trafficking and signaling, cell-cell adhesion, blood-group antigenicity, and immune response. In addition, the glycosylation of proteins is an important parameter in the optimization of many glycoprotein-based drugs such as monoclonal antibodies. In vitro glycoengineering of proteins requires glycosyltransferases as well as expensive nucleotide sugars. Here, we present a designed pathway consisting of five enzymes, glucokinase (Glk), phosphomannomutase (ManB), mannose-1-phosphate-guanyltransferase (ManC), inorganic pyrophosphatase (PmPpA), and 1-domain polyphosphate kinase 2 (1D-Ppk2) expressed in E. coli for the cell-free production and regeneration of GDP-mannose from mannose and polyphosphate with catalytic amounts of GDP and ADP. It was shown that GDP-mannose is produced at various conditions, that is pH 7-8, temperature 25-35°C and co-factor concentrations of 5-20 mM MgCl 2 . The maximum reaction rate of GDP-mannose achieved was 2.7 μM/min at 30°C and 10 mM MgCl 2 producing 566 nmol GDP-mannose after a reaction time of 240 min. With respect to the initial GDP concentration (0.8 mM) this is equivalent to a yield of 71%. Additionally, the cascade was coupled to purified, transmembrane-deleted Alg1 (ALG1ΔTM), the first mannosyltransferase in the ER-associated lipid-linked oligosaccharide (LLO) assembly. Thereby, in a one-pot reaction, phytanyl-PP-(GlcNAc) 2 -Man 1 was produced with efficient nucleotide sugar regeneration for the first time. Phytanyl-PP-(GlcNAc) 2 -Man 1 can serve as a substrate for the synthesis of LLO for the cell-free in vitro glycosylation of proteins. A high-performance anion exchange chromatography method with UV and conductivity detection (HPAEC-UV/CD) assay was optimized and validated to determine the enzyme kinetics. The established

  17. Lamellar crystalline self-assembly behaviour and solid lipid nanoparticles of a palmityl prodrug analogue of Capecitabine—A chemotherapy agent

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Xiaojuan; Moghaddam, Minoo J.; Sagnella, Sharon M.; Conn, Charlotte E.; Danon, Stephen J.; Waddington, Lynne J.; Drummond, Calum J. [CSIRO/MSE

    2014-09-24

    An amphiphile prodrug, 5'-deoxy-5-fluoro-N4-(palmityloxycarbonyl) cytidine or 5'-deoxy-5-fluoro-N4-(hexadecanaloxycarbonyl) cytidine (5-FCPal), consisting of the same head group as the commercially available chemotherapeutic agent Capecitabine, linked to a palmityl hydrocarbon chain via a carbamate bond is reported. Thermal analysis of this prodrug indicates that it melts at ~115 °C followed quickly by degradation beginning at ~120 °C. The neat solid 5-FCPal amphiphile acquires a lamellar crystalline arrangement with a d-spacing of 28.6 ± 0.3 Å, indicating interdigitation of the hydrocarbon chains. Under aqueous conditions, solid 5-FCPal is non-swelling and no lyotropic liquid crystalline phase formation is observed. In order to assess the in vitro toxicity and in vivo efficacy in colloidal form, solid lipid nanoparticles (SLNs) with an average size of ~700 nm were produced via high pressure homogenization. The in vitro toxicity of the 5-FCPal SLNs against several different cancer and normal cell types was assessed over a 48 h period, and IC50 values were comparable to those observed for Capecitabine. The in vivo efficacy of the 5-FCPal SLNs was then assessed against the highly aggressive mouse 4T1 breast cancer model. To do so, the prodrug SLNs were administered orally at 3 different dosages (0.1, 0.25, 0.5 mmol/mouse/day) and compared to Capecitabine delivered at the same dosages. After 21 days of receiving the treatments, the 0.5 mmol dose of 5-FCPal exhibited the smallest average tumour volume. Since 5-FCPal is activated in a similar manner to Capecitabine via a 3 step enzymatic pathway with the final step occurring preferentially at the tumour site, formulation of the prodrug into SLNs combines the advantage of selective, localized activation with the sustained release properties of nanostructured amphiphile self-assembly and multiple payload materials thereby potentially creating a more effective anticancer agent.

  18. Solid phase microbial fuel cell (SMFC) for harnessing bioelectricity from composite food waste fermentation: influence of electrode assembly and buffering capacity.

    Science.gov (United States)

    Mohan, S Venkata; Chandrasekhar, K

    2011-07-01

    Solid phase microbial fuel cells (SMFC; graphite electrodes; open-air cathode) were designed to evaluate the potential of bioelectricity production by stabilizing composite canteen based food waste. The performance was evaluated with three variable electrode-membrane assemblies. Experimental data depicted feasibility of bioelectricity generation from solid state fermentation of food waste. Distance between the electrodes and presence of proton exchange membrane (PEM) showed significant influence on the power yields. SMFC-B (anode placed 5 cm from cathode-PEM) depicted good power output (463 mV; 170.81 mW/m(2)) followed by SMFC-C (anode placed 5 cm from cathode; without PEM; 398 mV; 53.41 mW/m(2)). SMFC-A (PEM sandwiched between electrodes) recorded lowest performance (258 mV; 41.8 mW/m(2)). Sodium carbonate amendment documented marked improvement in power yields due to improvement in the system buffering capacity. SMFCs operation also documented good substrate degradation (COD, 76%) along with bio-ethanol production. The operation of SMFC mimicked solid-sate fermentation which might lead to sustainable solid waste management practices. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. 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)

  20. Anchoring of self-assembled plasmid DNA/ anti-DNA antibody/cationic lipid micelles on bisphosphonate-modified stent for cardiovascular gene delivery

    Directory of Open Access Journals (Sweden)

    Ma G

    2013-03-01

    Full Text Available Guilei Ma,1,# Yong Wang,1,# Ilia Fishbein,2 Mei Yu,1 Linhua Zhang,1 Ivan S Alferiev,2 Jing Yang,1 Cunxian Song,1 Robert J Levy2 1Institute of Biomedical Engineering, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, People's Republic of China; 2Children's Hospital of Philadelphia, Abramson Research Building, Philadelphia, PA, USA #These authors contributed equally to this work Purpose: To investigate the anchoring of plasmid DNA/anti-DNA antibody/cationic lipid tri-complex (DAC micelles onto bisphosphonate-modified 316 L coronary stents for cardiovascular site-specific gene delivery. Methods: Stents were first modified with polyallylamine bisphosphonate (PAA-BP, thereby enabling the retention of a PAA-BP molecular monolayer that permits the anchoring (via vector-binding molecules of DAC micelles. DAC micelles were then chemically linked onto the PAA-BP-modified stents by using N-succinimidyl-3-(2-pyridyldithiol-propionate (SPDP as a crosslinker. Rhodamine-labeled DNA was used to assess the anchoring of DAC micelles, and radioactive-labeled antibody was used to evaluate binding capacity and stability. DAC micelles (encoding green fluorescent protein were tethered onto the PAA-BP-modified stents, which were assessed in cell culture. The presence of a PAA-BP molecular monolayer on the steel surface was confirmed by X-ray photoelectron spectroscopy and atomic force microscope analysis. Results: The anchoring of DAC micelles was generally uniform and devoid of large-scale patches of defects. Isotopic quantification confirmed that the amount of antibody chemically linked on the stents was 17-fold higher than that of the physical adsorbed control stents and its retention time was also significantly longer. In cell culture, numerous green fluorescent protein-positive cells were found on the PAA-BP modified stents, which demonstrated high localization and efficiency of gene delivery. Conclusion: The DAC micelle

  1. Effects of high pressure on internally self-assembled lipid nanoparticles: a synchrotron small-angle X-ray scattering (SAXS) study

    Czech Academy of Sciences Publication Activity Database

    Kulkarni, C. V.; Yaghmur, A.; Steinhart, Miloš; Kriechbaum, M.; Rappolt, M.

    2016-01-01

    Roč. 32, č. 45 (2016), s. 11907-11917 ISSN 0743-7463 Institutional support: RVO:61389013 Keywords : self-assebled lipid nanoparticles * synchrotron * SAXS Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.833, year: 2016

  2. A close collaboration of chitosan with lipid colloidal carriers for drug delivery applications.

    Science.gov (United States)

    Bugnicourt, Loïc; Ladavière, Catherine

    2017-06-28

    Chitosan and lipid colloids have separately shown a growing interest in the field of drug delivery applications. Their success is mainly due to their interesting physicochemical behaviors, as well as their biological properties such as bioactivity and biocompatibility. While chitosan is a well-known cationic polysaccharide with the ability to strongly interact with drugs and biological matrices through mainly electrostatic interactions, lipid colloids are carriers particularly recognized for the drug vectorization. In recent years, the combination of both entities has been considered because it offers new systems which gather the advantages of each of them to efficiently deliver various types of bioactive species. The purpose of this review is to describe these associations between chemically-unmodified chitosan chains (solubilized or dispersed) and lipid colloids (as nanoparticles or organized in lipid layers), as well as their potential in the drug delivery area so far. Three assemblies have mainly been reported in the literature: i) lipid nanoparticles (solid lipid nanoparticles or nanostructured lipid carriers) coated with chitosan chains, ii) lipid vesicles covered with chitosan chains, and iii) chitosan chains structured in nanoparticles with a lipid coating. Their elaboration processes, their physicochemical characterization, and their biological studies are detailed and discussed herein. The different bioactive species (drugs and bio(macro)molecules) incorporated in these assemblies, their maximal incorporation efficiency, and their loading capacity are also presented. This review reveals the versatility of these assemblies. Depending on the organization of lipids (i.e., nanoparticles or vesicles) and the state of polymer chains (i.e., solubilized or dispersed under the form of nanoparticles), a large variety of drugs can be successfully incorporated, and various routes of administration can be considered. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. The effects of synbiotic supplementation on insulin resistance/sensitivity, lipid profile and total antioxidant capacity in women with gestational diabetes mellitus: A randomized double blind placebo controlled clinical trial.

    Science.gov (United States)

    Nabhani, Zohoor; Hezaveh, Seyed Jamal Ghaemmaghami; Razmpoosh, Elham; Asghari-Jafarabadi, Mohammad; Gargari, Bahram Pourghassem

    2018-04-01

    The role of gut microbiota in the management of diabetes is shown. In this randomized clinical trial we assessed the effects of synbiotic supplementation on insulin, lipid profile and antioxidative status among women with gestational diabetes mellitus (GDM). Ninety pregnant women with GDM were randomly assigned into two groups to receive either a daily synbiotic capsule - consisting of L. acidophilus, L. plantarum, L. fermentum, L. gasseri (1.5-7.0 × 10 9-10  CFU/g) - with fructooligosaccharide (38.5 mg), or placebo for 6 weeks. Fasting plasma glucose (FPG), insulin, homeostasis model assessment-insulin resistance (HOMA-IR), quantitative insulin sensitivity check index (QUICKI), high- and low density lipoprotein cholesterol (HDL-C, LDL-C), total cholesterol (TC), triglycerides (TG), total antioxidant capacity (TAC), and systolic and diastolic blood pressure (SBP, DSP) were assessed before and after the intervention. No significant changes in FPG, insulin resistance/sensitivity, lipid profile and TAC indices were seen in synbiotic group compared to the placebo one (p > 0.05). Significant within group increases for HDL-C and TAC levels in synbiotic group were observed (p insulin resistance/sensitivity indices. Lipid profile and TAC status may be affected by synbiotic supplementation. Synbiotic is effective in reducing of blood pressure in women with GDM. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. Computational Models of the Gastrointestinal Environment. 2. Phase Behavior and Drug Solubilization Capacity of a Type I Lipid-Based Drug Formulation after Digestion.

    Science.gov (United States)

    Birru, Woldeamanuel A; Warren, Dallas B; Han, Sifei; Benameur, Hassan; Porter, Christopher J H; Pouton, Colin W; Chalmers, David K

    2017-03-06

    Lipid-based drug formulations can greatly enhance the bioavailability of poorly water-soluble drugs. Following the oral administration of formulations containing tri- or diglycerides, the digestive processes occurring within the gastrointestinal (GI) tract hydrolyze the glycerides to mixtures of free fatty acids and monoglycerides that are, in turn, solubilized by bile. The behavior of drugs within the resulting colloidal mixtures is currently not well characterized. This work presents matched in vitro experimental and molecular dynamics (MD) theoretical models of the GI microenvironment containing a digested triglyceride-based (Type I) drug formulation. Both the experimental and theoretical models consist of molecular species representing bile (glycodeoxycholic acid), digested triglyceride (1:2 glyceryl-1-monooleate and oleic acid), and water. We have characterized the phase behavior of the physical system using nephelometry, dynamic light scattering, and polarizing light microscopy and compared these measurements to phase behavior observed in multiple MD simulations. Using this model microenvironment, we have investigated the dissolution of the poorly water-soluble drug danazol experimentally using LC-MS and theoretically by MD simulation. The results show how the formulation lipids alter the environment of the GI tract and improve the solubility of danazol. The MD simulations successfully reproduce the experimental results showing the utility of MD in modeling the fate of drugs after digestion of lipid-based formulations within the intestinal lumen.

  5. Dietary DHA/EPA ratio affected tissue fatty acid profiles, antioxidant capacity, hematological characteristics and expression of lipid-related genes but not growth in juvenile black seabream (Acanthopagrus schlegelii).

    Science.gov (United States)

    Jin, Min; Monroig, Óscar; Lu, You; Yuan, Ye; Li, Yi; Ding, Liyun; Tocher, Douglas R; Zhou, Qicun

    2017-01-01

    An 8-week feeding trial was conducted to investigate the effects of dietary docosahexaenoic to eicosapentaenoic acid ratio (DHA/EPA) on growth performance, fatty acid profiles, antioxidant capacity, hematological characteristics and expression of some lipid metabolism related genes of juvenile black seabream (Acanthopagrus schlegelii) of initial weight 9.47 ± 0.03 g. Five isonitrogenous and isolipidic diets (45% crude protein and 14% crude lipid) were formulated to contain graded DHA/EPA ratios of 0.65, 1.16, 1.60, 2.03 and 2.67. There were no differences in growth performance and feed utilization among treatments. Fish fed higher DHA/EPA ratios had higher malondialdehyde (MDA) contents in serum than lower ratios. Serum triacylglycerol (TAG) content was significantly higher in fish fed the lowest DHA/EPA ratio. Tissue fatty acid profiles reflected the diets despite down-regulation of LC-PUFA biosynthesis genes, fatty acyl desaturase 2 (fads2) and elongase of very long-chain fatty acids 5 (elovl5), by high DHA/EPA ratios. Expression of acetyl-CoA carboxylase alpha (accα) and carnitine palmitoyl transferase 1A (cpt1a) were up-regulated by high DHA/EPA ratio, whereas sterol regulatory element-binding protein-1 (srebp-1) and hormone-sensitive lipase (hsl) were down-regulated. Fatty acid synthase (fas), 6-phosphogluconate dehydrogenase (6pgd) and peroxisome proliferator-activated receptor alpha (pparα) showed highest expression in fish fed intermediate (1.16) DHA/EPA ratio. Overall, this study indicated that dietary DHA/EPA ratio affected fatty acid profiles and significantly influenced lipid metabolism including LC-PUFA biosynthesis and other anabolic and catabolic pathways, and also had impacts on antioxidant capacity and hematological characteristics.

  6. Effects of supplementation with acai (Euterpe oleracea Mart.) berry-based juice blend on the blood antioxidant defence capacity and lipid profile in junior hurdlers. A pilot study

    OpenAIRE

    Sadowska-Kr?pa, E; K?apci?ska, B; Podg?rski, T; Szade, B; Tyl, K; Hadzik, A

    2015-01-01

    The purpose of this pilot study was to examine whether regular consumption of an acai berry-based juice blend would affect sprint performance and improve blood antioxidant status and lipid profile in junior athletes. Seven junior hurdlers (17.5±1.2 years) taking part in a pre-season conditioning camp were supplemented once a day, for six weeks, with 100 ml of the juice blend. At the start and the end of the camp the athletes performed a 300-m sprint running test on an outdoor track. Blood sam...

  7. Early LC3 lipidation induced by d-limonene does not rely on mTOR inhibition, ERK activation and ROS production and it is associated with reduced clonogenic capacity of SH-SY5Y neuroblastoma cells.

    Science.gov (United States)

    Berliocchi, Laura; Chiappini, Carlotta; Adornetto, Annagrazia; Gentile, Debora; Cerri, Silvia; Russo, Rossella; Bagetta, Giacinto; Corasaniti, Maria Tiziana

    2018-02-01

    stimulates ROS generation, yet none of these events is implicated in lipidation of LC3, which was only partly reduced by chelation of intracellular calcium. The early LC3 lipidation induced by d-limonene is associated with inhibition of clonogenic capacity which is reverted by the autophagy inhibitor chloroquine. d-Limonene rapidly stimulates the autophagic flux in cultured cancer cells, which could be usefully exploited for therapeutic purposes. Copyright © 2018 Elsevier GmbH. All rights reserved.

  8. Effects of Lateral and Terminal Chains of X-Shaped Bolapolyphiles with Oligo(phenylene ethynylene Cores on Self-Assembly Behavior. Part 2: Domain Formation by Self-Assembly in Lipid Bilayer Membranes

    Directory of Open Access Journals (Sweden)

    Stefan Werner

    2017-09-01

    Full Text Available Supramolecular self-assembly of membrane constituents within a phospholipid bilayer creates complex functional platforms in biological cells that operate in intracellular signaling, trafficking and membrane remodeling. Synthetic polyphilic compounds of macromolecular or small size can be incorporated into artificial phospholipid bilayers. Featuring three or four moieties of different philicities, they reach beyond ordinary amphiphilicity and open up avenues to new functions and interaction concepts. Here, we have incorporated a series of X-shaped bolapolyphiles into DPPC (1,2-dipalmitoyl-sn-glycero-3-phosphocholine bilayers of giant unilamellar vesicles. The bolapolyphiles consist of a rod-like oligo(phenylene ethynylene (OPE core, hydrophilic glycerol-based headgroups with or without oligo(ethylene oxide expansions at both ends and two lateral alkyl chains attached near the center of the OPE core. In the absence of DPPC and water, the compounds showed thermotropic liquid-crystalline behavior with a transition between polyphilic and amphiphilic assembly (see part 1 in this issue. In DPPC membranes, various trends in the domain morphologies were observed upon structure variations, which entailed branched alkyl chains of various sizes, alkyl chain semiperfluorination and size expansion of the headgroups. Observed effects on domain morphology are interpreted in the context of the bulk behavior (part 1 and of a model that was previously developed based on spectroscopic and physicochemical data.

  9. Efficient molecular mechanics simulations of the folding, orientation, and assembly of peptides in lipid bilayers using an implicit atomic solvation model

    Science.gov (United States)

    Bordner, Andrew J.; Zorman, Barry; Abagyan, Ruben

    2011-10-01

    Membrane proteins comprise a significant fraction of the proteomes of sequenced organisms and are the targets of approximately half of marketed drugs. However, in spite of their prevalence and biomedical importance, relatively few experimental structures are available due to technical challenges. Computational simulations can potentially address this deficit by providing structural models of membrane proteins. Solvation within the spatially heterogeneous membrane/solvent environment provides a major component of the energetics driving protein folding and association within the membrane. We have developed an implicit solvation model for membranes that is both computationally efficient and accurate enough to enable molecular mechanics predictions for the folding and association of peptides within the membrane. We derived the new atomic solvation model parameters using an unbiased fitting procedure to experimental data and have applied it to diverse problems in order to test its accuracy and to gain insight into membrane protein folding. First, we predicted the positions and orientations of peptides and complexes within the lipid bilayer and compared the simulation results with solid-state NMR structures. Additionally, we performed folding simulations for a series of host-guest peptides with varying propensities to form alpha helices in a hydrophobic environment and compared the structures with experimental measurements. We were also able to successfully predict the structures of amphipathic peptides as well as the structures for dimeric complexes of short hexapeptides that have experimentally characterized propensities to form beta sheets within the membrane. Finally, we compared calculated relative transfer energies with data from experiments measuring the effects of mutations on the free energies of translocon-mediated insertion of proteins into lipid bilayers and of combined folding and membrane insertion of a beta barrel protein.

  10. [Impact of plasma pro-B-type natriuretic peptide amino-terminal and galectin-3 levels on the predictive capacity of the LIPID Clinical Risk Scale in stable coronary disease].

    Science.gov (United States)

    Higueras, Javier; Martín-Ventura, José Luis; Blanco-Colio, Luis; Cristóbal, Carmen; Tarín, Nieves; Huelmos, Ana; Alonso, Joaquín; Pello, Ana; Aceña, Álvaro; Carda, Rocío; Lorenzo, Óscar; Mahíllo-Fernández, Ignacio; Asensio, Dolores; Almeida, Pedro; Rodríguez-Artalejo, Fernando; Farré, Jerónimo; López Bescós, Lorenzo; Egido, Jesús; Tuñón, José

    2015-01-01

    At present, there is no tool validated by scientific societies for risk stratification of patients with stable coronary artery disease (SCAD). It has been shown that plasma levels of monocyte chemoattractant protein-1 (MCP-1), galectin-3 and pro-B-type natriuretic peptide amino-terminal (NT-proBNP) have prognostic value in this population. To analyze the prognostic value of a clinical risk scale published in Long-term Intervention with Pravastatin in Ischemic Disease (LIPID) study and determining its predictive capacity when combined with plasma levels of MCP-1, galectin-3 and NT-proBNP in patients with SCAD. A total of 706 patients with SCAD and a history of acute coronary syndrome (ACS) were analyzed over a follow up period of 2.2 ± 0.99 years. The primary endpoint was the occurrence of an ischemic event (any SCA, stroke or transient ischemic attack), heart failure, or death. A clinical risk scale derived from the LIPID study significantly predicted the development of the primary endpoint, with an area under the ROC curve (Receiver Operating Characteristic) of 0.642 (0.579 to 0.705); Pvalue improved with an area under the curve of 0.744 (0.684 to 0.805); P<0.001 (P=0.022 for comparison). A score greater than 21.5 had a sensitivity of 74% and a specificity of 61% for the development of the primary endpoint (P<0.001, log -rank test). Plasma levels of MCP-1, galectin -3 and NT-proBNP improve the ability of the LIPID clinical scale to predict the prognosis of patients with SCAD. Copyright © 2014 Sociedad Española de Arteriosclerosis. Published by Elsevier España. All rights reserved.

  11. Body Composition, Lipid Profile, Adipokine Concentration, and Antioxidant Capacity Changes during Interventions to Treat Overweight with Exercise Programme and Whole-Body Cryostimulation

    Directory of Open Access Journals (Sweden)

    Anna Lubkowska

    2015-01-01

    Full Text Available The aim of this study was to determine the effect of six-month-long physical exercise programme with a two-time exposure to whole-body cryostimulation (WBC in 20 sessions on antioxidant enzyme activities, lipid profile, and body composition changes in obese people (30 adult subjects; BMI = 30.39 ± 4.31 kg/m2. Blood samples were taken before the programme, one month following the exercise programme, before and after the first WBC treatment, six months following the exercise programme, after the second WBC treatment, and finally one month after the intervention. Six months of moderate aerobic activity combined with WBC did not change body mass or fat and lean body mass percentages, or circulating adiponectin, leptin, and resistin concentrations. In response to intervention a significant decrease in the level of low-density lipoprotein and triglycerides was observed, with a slight increase in high-density lipoprotein concentration. The nature of changes in the activity of respective antioxidant enzymes was not identical. After one month of increased physical activity, a significant decrease in superoxide dismutase, catalase, and glutathione reductase activities was observed (13%, 8%, and 70%, resp.. The SOD activity increased significantly after successive whole-body cryostimulation sessions. As regards catalase, a significant progressive decrease in its activity was observed.

  12. Pharmaceutical optimization of lipid-based dosage forms for the improvement of taste-masking, chemical stability and solubilizing capacity of phenobarbital.

    Science.gov (United States)

    Monteagudo, Ezequiel; Langenheim, Mariana; Salerno, Claudia; Buontempo, Fabián; Bregni, Carlos; Carlucci, Adriana

    2014-06-01

    Microemulsions (MEs) and self-emulsifying drug delivery systems (SEEDS) containing phenobarbital (Phe) were developed to improve its chemical stability, solubilizing capacity and taste-masking in oral liquid dosage forms. Cremophor® RH40 and Labrasol® were used as surfactants for the screening of ME regions, Capmul® MCM L, Captex® 355, Imwitor® 408, Myglyol® 840 and Isopropyl myristate were the oil phases assayed; Transcutol® P, Polyethylene-glycol 400, glycerol, Propylene-glycol and ethanol the cosurfactants. Phe stability assay was carried out (20:4:20:56% and 20:4:35:41% (w/w); surfactant:oily phase:cosurfactant:water) for both surfactants; only one containing ethanol showed significant dismissing in its drug content. Solubility capacity for these selected formulations were also evaluated, an amount between 17 and 58 mg/mL of Phe could be loaded. At last, an optimized ME formulation with Cremophor® RH40 20%, Capmul® MCM L 4%, PEG 400 35% and sucralose 2% (w/w) was chosen in order to optimize taste-masking using an electronic tongue. Strawberry along with banana and tutti-frutti flavors plus mint flavor proved to be the best ones. Labrasol-based pre-concentrates were tested for (micro)emulsifying properties; all of them resulted to behave as SEDDS. In summary, a rationale experimental design conducted to an optimized ME for Phe oral pediatric administration which was able to load 5-fold times the currently used dose (4 mg/mL), with no sign of physical or chemical instability and with improved taste; SEDDS for capsule filling were also obtained. The biopharmaceutical advantages described for these dosage forms encourage furthering in vivo evaluation.

  13. Tandem fusion of hepatitis B core antigen allows assembly of virus-like particles in bacteria and plants with enhanced capacity to accommodate foreign proteins.

    Directory of Open Access Journals (Sweden)

    Hadrien Peyret

    Full Text Available The core protein of the hepatitis B virus, HBcAg, assembles into highly immunogenic virus-like particles (HBc VLPs when expressed in a variety of heterologous systems. Specifically, the major insertion region (MIR on the HBcAg protein allows the insertion of foreign sequences, which are then exposed on the tips of surface spike structures on the outside of the assembled particle. Here, we present a novel strategy which aids the display of whole proteins on the surface of HBc particles. This strategy, named tandem core, is based on the production of the HBcAg dimer as a single polypeptide chain by tandem fusion of two HBcAg open reading frames. This allows the insertion of large heterologous sequences in only one of the two MIRs in each spike, without compromising VLP formation. We present the use of tandem core technology in both plant and bacterial expression systems. The results show that tandem core particles can be produced with unmodified MIRs, or with one MIR in each tandem dimer modified to contain the entire sequence of GFP or of a camelid nanobody. Both inserted proteins are correctly folded and the nanobody fused to the surface of the tandem core particle (which we name tandibody retains the ability to bind to its cognate antigen. This technology paves the way for the display of natively folded proteins on the surface of HBc particles either through direct fusion or through non-covalent attachment via a nanobody.

  14. Low-crystallinity molybdenum sulfide nanosheets assembled on carbon nanotubes for long-life lithium storage: Unusual electrochemical behaviors and ascending capacities

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiaodan, E-mail: xiaodan_li@yeah.net [State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China ElectricPower University, Beijing, 102206 (China); Wu, Gaoxiang, E-mail: wgxjimmy@126.com [State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China ElectricPower University, Beijing, 102206 (China); Chen, Jiewei, E-mail: kzscjw@126.com [State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China ElectricPower University, Beijing, 102206 (China); Li, Meicheng, E-mail: mcli@ncepu.edu.cn [State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China ElectricPower University, Beijing, 102206 (China); Chongqing Materials Research Institute, Chongqing 400707 (China); Li, Wei, E-mail: wei.li@inl.int [International Iberian Nanotechnology Laboratory (INL), Braga 4715-330 (Portugal); Wang, Tianyue, E-mail: 1355796015@qq.com [State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China ElectricPower University, Beijing, 102206 (China); Jiang, Bing, E-mail: BingJiang@ncepu.edu.cn [State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China ElectricPower University, Beijing, 102206 (China); He, Yue, E-mail: 947667748@qq.com [State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China ElectricPower University, Beijing, 102206 (China); Mai, Liqiang, E-mail: mlq518@whut.edu.cn [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China)

    2017-01-15

    Highlights: • Low-crystallinity molybdenum sulfide coated on carbon nanotubes were synthesized. • This anode material has unusual electrochemical behaviors compared to typical MoS{sub 2}. • It exhibits noticable ascending trends in capacity and superior rate performance. • The ascending performance can effectively extend the circulation life of batteries. - Abstract: Low-crystallinity molybdenum sulfide (LCMS, Mo:S = 1:2.75) nanosheets synthesized by a facile and low temperature solvothermal method is now reported. The as-prepared LCMS anode material is composited of MoS{sub 2} layers mixed with amorphous MoS{sub 3}, which leads to an unusual electrochemical process for lithium storage compared to typical MoS{sub 2} anode. The existence of MoS{sub 3} and Mo (VI) provide strong adsorption and binding sites for polar polysulphides, which compels abundant sulfur to turn into new-formed MoS{sub 3} rather than diffuse into electrolyte. To fully utilize this novel electrochemical process, LCMS is decorated on carbon nanotubes, obtaining well-dispersed CNTs@LCMS. As electrode material for lithium storage, CNTs@LCMS exhibits a noticable ascending trend in capacity from 820 mA h g{sup −1} to 1350 mA h g{sup −1} at 100 mA g{sup −1} during 130 cycles. The persistent ascending capacity is ascribed to the increasing lithium storage caused by new-formed MoS{sub 3}, combined with the reduced volume change benifiting from well-dispersed CNTs@LCMS. Furthermore, the ascending performance is proved to be able to effectively extend the circulation life (up to 200%) for lithium-ion batteries by mathematical modeling and calculation. Accordingly, the CNTs@LCMS composite is a promising anode material for long-life lithium-ion batteries.

  15. Electric moulding of dispersed lipid nanotubes into a nanofluidic device.

    Science.gov (United States)

    Frusawa, Hiroshi; Manabe, Tatsuhiko; Kagiyama, Eri; Hirano, Ken; Kameta, Naohiro; Masuda, Mitsutoshi; Shimizu, Toshimi

    2013-01-01

    Hydrophilic nanotubes formed by lipid molecules have potential applications as platforms for chemical or biological events occurring in an attolitre volume inside a hollow cylinder. Here, we have integrated the lipid nanotubes (LNTs) by applying an AC electric field via plug-in electrode needles placed above a substrate. The off-chip assembly method has the on-demand adjustability of an electrode configuration, enabling the dispersed LNT to be electrically moulded into a separate film of parallel LNT arrays in one-step. The fluorescence resonance energy transfer technique as well as the digital microscopy visualised the overall filling of gold nanoparticles up to the inner capacity of an LNT film by capillary action, thereby showing the potential of this flexible film for use as a high-throughput nanofluidic device where not only is the endo-signalling and product in each LNT multiplied but also the encapsulated objects are efficiently transported and reacted.

  16. Self-assembled 3D ZnSnO3 hollow cubes@reduced graphene oxide aerogels as high capacity anode materials for lithium-ion batteries

    International Nuclear Information System (INIS)

    Wang, Yankun; Li, Dan; Liu, Yushan; Zhang, Jianmin

    2016-01-01

    Highlights: • 3D ZnSnO 3 hollow cubes@reducedgrapheneoxideaerogels(ZGAs) were fabricated. • The electrochemical properties of ZGAs were investigated for LIBs. • ZGAs demonstrated superior lithium storage performance. - Abstract: 3D ZnSnO 3 hollow cubes@reduced graphene oxide aerogels (ZGAs) were fabricated via a colloid electrostatic self-assembly method between the graphene oxide (GO) nanosheets and poly(diallyldimethylammonium chloride) (PDDA) modified ZnSnO 3 hollow cubes colloid, followed by hydrothermal and freeze-drying treatments. The unique porous architecture of ZnSnO 3 hollow cubes encapsulated by flexible reduced graphene oxide (rGO) sheets not only effectively retarded the huge volume expansion during repeated charge-discharge cycles, but also facilitated fast lithium ion and electron transport through 3D networks. The ZGAs exhibited significantly enhanced cycling stability (745.4 mAh g −1 after 100 cycles at a current of 100 mA g −1 ) and superior rate capability (as high as 552.6 mAh g −1 at 1200 mA g −1 ). The results indicate that the ZGAs are promising anode materials for high-performance lithium-ion batteries.

  17. Formation of milk lipids: a molecular perspective

    OpenAIRE

    McManaman, James L

    2009-01-01

    Lipids, primarily triglycerides, are major milk constituents of most mammals, providing a large percentage of calories, essential fatty acids and bioactive lipids required for neonatal growth and development. To meet the caloric and nutritional demands of newborns, the mammary glands of most species have evolved an enormous capacity to synthesize and secrete large quantities of lipids during lactation. Significant information exists regarding the physiological regulation of lipid metabolism i...

  18. 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....

  19. Atomistic Monte Carlo simulation of lipid membranes

    DEFF Research Database (Denmark)

    Wüstner, Daniel; Sklenar, Heinz

    2014-01-01

    Biological membranes are complex assemblies of many different molecules of which analysis demands a variety of experimental and computational approaches. In this article, we explain challenges and advantages of atomistic Monte Carlo (MC) simulation of lipid membranes. We provide an introduction...... of local-move MC methods in combination with molecular dynamics simulations, for example, for studying multi-component lipid membranes containing cholesterol....

  20. Bacteriophage Assembly

    Directory of Open Access Journals (Sweden)

    Anastasia A. Aksyuk

    2011-02-01

    Full Text Available Bacteriophages have been a model system to study assembly processes for over half a century. Formation of infectious phage particles involves specific protein-protein and protein-nucleic acid interactions, as well as large conformational changes of assembly precursors. The sequence and molecular mechanisms of phage assembly have been elucidated by a variety of methods. Differences and similarities of assembly processes in several different groups of bacteriophages are discussed in this review. The general principles of phage assembly are applicable to many macromolecular complexes.

  1. Fuel assemblies

    International Nuclear Information System (INIS)

    Nakatsuka, Masafumi.

    1979-01-01

    Purpose: To prevent scattering of gaseous fission products released from fuel assemblies stored in an fbr type reactor. Constitution; A cap provided with means capable of storing gas is adapted to amount to the assembly handling head, for example, by way of threading in a storage rack of spent fuel assemblies consisting of a bottom plate, a top plate and an assembly support mechanism. By previously eliminating the gas inside of the assembly and the cap in the storage rack, gaseous fission products upon loading, if released from fuel rods during storage, are stored in the cap and do not scatter in the storage rack. (Horiuchi, T.)

  2. Sequence assembly

    DEFF Research Database (Denmark)

    Scheibye-Alsing, Karsten; Hoffmann, S.; Frankel, Annett Maria

    2009-01-01

    Despite the rapidly increasing number of sequenced and re-sequenced genomes, many issues regarding the computational assembly of large-scale sequencing data have remain unresolved. Computational assembly is crucial in large genome projects as well for the evolving high-throughput technologies and...... in genomic DNA, highly expressed genes and alternative transcripts in EST sequences. We summarize existing comparisons of different assemblers and provide a detailed descriptions and directions for download of assembly programs at: http://genome.ku.dk/resources/assembly/methods.html....

  3. 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.

  4. Lipid measures and cardiovascular disease prediction

    NARCIS (Netherlands)

    van Wijk, D.F.; Stroes, E.S.G.; Kastelein, J.J.P.

    2009-01-01

    Traditional lipid measures are the cornerstone of risk assessment and treatment goals in cardiovascular prevention. Whereas the association between total, LDL-, HDL-cholesterol and cardiovascular disease risk has been generally acknowledged, the rather poor capacity to distinguish between patients

  5. Biologic activity of porphyromonas endodontalis complex lipids.

    Science.gov (United States)

    Mirucki, Christopher S; Abedi, Mehran; Jiang, Jin; Zhu, Qiang; Wang, Yu-Hsiung; Safavi, Kamran E; Clark, Robert B; Nichols, Frank C

    2014-09-01

    Periapical infections secondary to pulpal necrosis are associated with bacterial contamination of the pulp. Porphyromonas endodontalis, a gram-negative organism, is considered to be a pulpal pathogen. P. gingivalis is phylogenetically related to P. endodontalis and synthesizes several classes of novel complex lipids that possess biological activity, including the capacity to promote osteoclastogenesis and osteoclast activation. The purpose of this study was to extract and characterize constituent lipids of P. endodontalis and evaluate their capacity to promote proinflammatory secretory responses in the macrophage cell line, RAW 264.7, as well as their capacity to promote osteoclastogenesis and inhibit osteoblast activity. Constituent lipids of both organisms were fractionated by high-performance liquid chromatography and were structurally characterized using electrospray mass spectrometry or electrospray-mass spectrometry/mass spectrometry. The virulence potential of P. endodontalis lipids was then compared with known biologically active lipids isolated from P. gingivalis. P. endodontalis total lipids were shown to promote tumor necrosis factor alpha secretion from RAW 264.7 cells, and the serine lipid fraction appeared to account for the majority of this effect. P. endodontalis lipid preparations also increased osteoclast formation from RAW 264.7 cells, but osteoblast differentiation in culture was inhibited and appeared to be dependent on Toll-like receptor 2 expression. These effects underscore the importance of P. endodontalis lipids in promoting inflammatory and bone cell activation processes that could lead to periapical pathology. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  6. 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 ...

  7. 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.

  8. Storage method for spent fuel assembly

    International Nuclear Information System (INIS)

    Tajiri, Hiroshi.

    1992-01-01

    In the present invention, spent fuel assemblies are arranged at a dense pitch in a storage rack by suppressing the reactivity of the assemblies, to increase storage capacity for the spent fuel assemblies. That is, neutron absorbers are filled in the cladding tube of an absorbing rod, and the diameter thereof is substantially equal with that of a fuel rod. A great amount of the absorbing rods are arranged at the outer circumference of the fuel assembly. Then, they are fixed integrally to the fuel assembly and stored in a storage rack. In this case, the storage rack may be constituted only with angle materials which are inexpensive and installed simply. With such a constitution, in the fuel assembly having absorbing rods wound therearound, neutrons are absorbed by absorbing rods and the reactivity is lowered. Accordingly, the assembly arrangement pitch in the storage rack can be made dense. As a result, the storage capacity for the assemblies is increased. (I.S.)

  9. Seismic capacity of switchgear

    International Nuclear Information System (INIS)

    Bandyopadhyay, K.; Hofmayer, C.; Kassir, M.; Pepper, S.

    1989-01-01

    As part of a component fragility program sponsored by the USNRC, BNL has collected existing information on the seismic capacity of switchgear assemblies from major manufacturers. Existing seismic test data for both low and medium voltage switchgear assemblies have been evaluated and the generic results are presented in this paper. The failure modes are identified and the corresponding generic lower bound capacity levels are established. The test response spectra have been used as a measure of the test vibration input. The results indicate that relays chatter at a very low input level at the base of the switchgear cabinet. This change of state of devices including relays have been observed. Breaker tripping occurs at a higher vibration level. Although the structural failure of internal elements have been noticed, the overall switchgear cabinet structure withstands a high vibration level. 5 refs., 2 figs., 2 tabs

  10. Synthetic Self-Assembled Materials in Biological Environments

    NARCIS (Netherlands)

    Versluis, F.; van Esch, J.H.; Eelkema, R.

    2016-01-01

    Synthetic self-assembly has long been recognized as an excellent approach for the formation of ordered structures on the nanoscale. Although the development of synthetic self-assembling materials has often been inspired by principles observed in nature (e.g., the assembly of lipids, DNA,

  11. Computer Simulations of Lipid Nanoparticles

    Directory of Open Access Journals (Sweden)

    Xavier F. Fernandez-Luengo

    2017-12-01

    Full Text Available Lipid nanoparticles (LNP are promising soft matter nanomaterials for drug delivery applications. In spite of their interest, little is known about the supramolecular organization of the components of these self-assembled nanoparticles. Here, we present a molecular dynamics simulation study, employing the Martini coarse-grain forcefield, of self-assembled LNPs made by tripalmitin lipid in water. We also study the adsorption of Tween 20 surfactant as a protective layer on top of the LNP. We show that, at 310 K (the temperature of interest in biological applications, the structure of the lipid nanoparticles is similar to that of a liquid droplet, in which the lipids show no nanostructuration and have high mobility. We show that, for large enough nanoparticles, the hydrophilic headgroups develop an interior surface in the NP core that stores liquid water. The surfactant is shown to organize in an inhomogeneous way at the LNP surface, with patches with high surfactant concentrations and surface patches not covered by surfactant.

  12. 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.

  13. Proteomic analysis of lipid droplets from Caco-2/TC7 enterocytes identifies novel modulators of lipid secretion.

    Directory of Open Access Journals (Sweden)

    Frauke Beilstein

    Full Text Available In enterocytes, the dynamic accumulation and depletion of triacylglycerol (TAG in lipid droplets (LD during fat absorption suggests that cytosolic LD-associated TAG contribute to TAG-rich lipoprotein (TRL production. To get insight into the mechanisms controlling the storage/secretion balance of TAG, we used as a tool hepatitis C virus core protein, which localizes onto LDs, and thus may modify their protein coat and decrease TRL secretion. We compared the proteome of LD fractions isolated from Caco-2/TC7 enterocytes expressing or not hepatitis C virus core protein by a differential proteomic approach (isobaric tag for relative and absolute quantitation (iTRAQ labeling coupled with liquid chromatography and tandem mass spectrometry. We identified 42 proteins, 21 being involved in lipid metabolism. Perilipin-2/ADRP, which is suggested to stabilize long term-stored TAG, was enriched in LD fractions isolated from Caco-2/TC7 expressing core protein while perilipin-3/TIP47, which is involved in LD synthesis from newly synthesized TAG, was decreased. Endoplasmic reticulum-associated proteins were strongly decreased, suggesting reduced interactions between LD and endoplasmic reticulum, where TRL assembly occurs. For the first time, we show that 17β-hydroxysteroid dehydrogenase 2 (DHB2, which catalyzes the conversion of 17-keto to 17 β-hydroxysteroids and which was the most highly enriched protein in core expressing cells, is localized to LD and interferes with TAG secretion, probably through its capacity to inactivate testosterone. Overall, we identified potential new players of lipid droplet dynamics, which may be involved in the balance between lipid storage and secretion, and may be altered in enterocytes in pathological conditions such as insulin resistance, type II diabetes and obesity.

  14. Station Capacity

    DEFF Research Database (Denmark)

    Landex, Alex

    2011-01-01

    the probability of conflicts and the minimum headway times into account. The last method analyzes how optimal platform tracks are used by examining the arrival and departure pattern of the trains. The developed methods can either be used separately to analyze specific characteristics of the capacity of a station......Stations are often limiting the capacity of railway networks. This is due to extra need of tracks when trains stand still, trains turning around, and conflicting train routes. Although stations are often the capacity bottlenecks, most capacity analysis methods focus on open line capacity. Therefore...... for platform tracks and the probability that arriving trains will not get a platform track immediately at arrival. The third method is a scalable method that analyzes the conflicts in the switch zone(s). In its simplest stage, the method just analyzes the track layout while the more advanced stages also take...

  15. Fuel assembly

    International Nuclear Information System (INIS)

    Abe, Hideaki; Sakai, Takao; Ishida, Tomio; Yokota, Norikatsu.

    1992-01-01

    The lower ends of a plurality of plate-like shape memory alloys are secured at the periphery of the upper inside of the handling head of a fuel assembly. As the shape memory alloy, a Cu-Zn alloy, a Ti-Pd alloy or a Fe-Ni alloy is used. When high temperature coolants flow out to the handling head, the shape memory alloy deforms by warping to the outer side more greatly toward the upper portion thereof with the temperature increase of the coolants. As the result, the shape of the flow channel of the coolants is changed so as to enlarge at the exit of the upper end of the fuel assembly. Then, the pressure loss of the coolants in the fuel assembly is decreased by the enlargement. Accordingly, the flow rate of the coolants in the fuel assembly is increased to lower the temperature of the coolants. Further, high temperature coolants and low temperature coolants are mixed sufficiently just above the fuel assembly. This can suppress the temperature fluctuation of the mixed coolants in the upper portion of the reactor core, thereby enabling to decrease a fatigue and failures of the structural components in the upper portion of the reactor core. (I.N.)

  16. Layer-by-layer cell membrane assembly

    Science.gov (United States)

    Matosevic, Sandro; Paegel, Brian M.

    2013-11-01

    Eukaryotic subcellular membrane systems, such as the nuclear envelope or endoplasmic reticulum, present a rich array of architecturally and compositionally complex supramolecular targets that are as yet inaccessible. Here we describe layer-by-layer phospholipid membrane assembly on microfluidic droplets, a route to structures with defined compositional asymmetry and lamellarity. Starting with phospholipid-stabilized water-in-oil droplets trapped in a static droplet array, lipid monolayer deposition proceeds as oil/water-phase boundaries pass over the droplets. Unilamellar vesicles assembled layer-by-layer support functional insertion both of purified and of in situ expressed membrane proteins. Synthesis and chemical probing of asymmetric unilamellar and double-bilayer vesicles demonstrate the programmability of both membrane lamellarity and lipid-leaflet composition during assembly. The immobilized vesicle arrays are a pragmatic experimental platform for biophysical studies of membranes and their associated proteins, particularly complexes that assemble and function in multilamellar contexts in vivo.

  17. Fuel assembly

    International Nuclear Information System (INIS)

    Nakatsuka, Masafumi; Matsuzuka, Ryuji.

    1976-01-01

    Object: To provide a fuel assembly which can decrease pressure loss of coolant to uniform temperature. Structure: A sectional area of a flow passage in the vicinity of an inner peripheral surface of a wrapper tube is limited over the entire length to prevent the temperature of a fuel element in the outermost peripheral portion from being excessively decreased to thereby flatten temperature distribution. To this end, a plurality of pincture-frame-like sheet metals constituting a spacer for supporting a fuel assembly, which has a plurality of fuel elements planted lengthwise and in given spaced relation within the wrapper tube, is disposed in longitudinal grooves and in stacked fashion to form a substantially honeycomb-like space in cross section. The fuel elements are inserted and supported in the space to form a fuel assembly. (Kamimura, M.)

  18. Fuel assemblies

    International Nuclear Information System (INIS)

    Nagano, Mamoru; Yoshioka, Ritsuo

    1983-01-01

    Purpose: To effectively utilize nuclear fuels by increasing the reactivity of a fuel assembly and reduce the concentration at the central region thereof upon completion of the burning. Constitution: A fuel assembly is bisected into a central region and a peripheral region by disposing an inner channel box within a channel box. The flow rate of coolants passing through the central region is made greater than that in the peripheral region. The concentration of uranium 235 of the fuel rods in the central region is made higher. In such a structure, since the moderating effect in the central region is improved, the reactivity of the fuel assembly is increased and the uranium concentration in the central region upon completion of the burning can be reduced, fuel economy and effective utilization of uranium can be attained. (Kamimura, M.)

  19. Bis-polymer lipid-peptide conjugates and nanoparticles thereof

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Ting; Dong, He; Shu, Jessica; Dube, Nikhil

    2018-04-24

    The present invention provides bis-polymer lipid-peptide conjugates containing a hydrophobic block and headgroup containing a helical peptide and two polymer blocks. The conjugates can self-assemble to form helix bundle subunits, which in turn assemble to provide micellar nanocarriers for drug cargos and other agents. Particles containing the conjugates and methods for forming the particles are also disclosed.

  20. Hepatitis C Virus Life Cycle and Lipid Metabolism

    Directory of Open Access Journals (Sweden)

    Costin-Ioan Popescu

    2014-12-01

    Full Text Available Hepatitis C Virus (HCV infects over 150 million people worldwide. In most cases HCV infection becomes chronic, causing liver disease ranging from fibrosis to cirrhosis and hepatocellular carcinoma. HCV affects the cholesterol homeostasis and at the molecular level, every step of the virus life cycle is intimately connected to lipid metabolism. In this review, we present an update on the lipids and apolipoproteins that are involved in the HCV infectious cycle steps: entry, replication and assembly. Moreover, the result of the assembly process is a lipoviroparticle, which represents a peculiarity of hepatitis C virion. This review illustrates an example of an intricate virus-host interaction governed by lipid metabolism.

  1. Valve assembly

    International Nuclear Information System (INIS)

    Sandling, M.

    1981-01-01

    An improved valve assembly, used for controlling the flow of radioactive slurry, is described. Radioactive contamination of the air during removal or replacement of the valve is prevented by sucking air from the atmosphere through a portion of the structure above the valve housing. (U.K.)

  2. Fuel assembly

    International Nuclear Information System (INIS)

    Gjertsen, R.K.; Bassler, E.A.; Huckestein, E.A.; Salton, R.B.; Tower, S.N.

    1988-01-01

    A fuel assembly adapted for use with a pressurized water nuclear reactor having capabilities for fluid moderator spectral shift control is described comprising: parallel arranged elongated nuclear fuel elements; means for providing for axial support of the fuel elements and for arranging the fuel elements in a spaced array; thimbles interspersed among the fuel elements adapted for insertion of a rod control cluster therewithin; means for structurally joining the fuel elements and the guide thimbles; fluid moderator control means for providing a volume of low neutron absorbing fluid within the fuel assembly and for removing a substantially equivalent volume of reactor coolant water therefrom, a first flow manifold at one end of the fuel assembly sealingly connected to a first end of the moderator control tubes whereby the first ends are commonly flow connected; and a second flow manifold, having an inlet passage and an outlet passage therein, sealingly connected to a second end of the moderator control tubes at a second end of the fuel assembly

  3. 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.

  4. The role of the kidney in lipid metabolism

    DEFF Research Database (Denmark)

    Moestrup, Søren K; Nielsen, Lars Bo

    2005-01-01

    PURPOSE OF REVIEW: Cellular uptake of plasma lipids is to a large extent mediated by specific membrane-associated proteins that recognize lipid-protein complexes. In the kidney, the apical surface of proximal tubules has a high capacity for receptor-mediated uptake of filtered lipid-binding plasma...... proteins. We describe the renal receptor system and its role in lipid metabolism in health and disease, and discuss the general effect of the diseased kidney on lipid metabolism. RECENT FINDINGS: Megalin and cubilin are receptors in the proximal tubules. An accumulating number of lipid......-binding and regulating proteins (e.g. albumin, apolipoprotein A-I and leptin) have been identified as ligands, suggesting that their receptors may directly take up lipids in the proximal tubules and indirectly affect plasma and tissue lipid metabolism. Recently, the amnionless protein was shown to be essential...

  5. DNA release from lipoplexes by anionic lipids: correlation with lipid mesomorphism, interfacial curvature, and membrane fusion

    Energy Technology Data Exchange (ETDEWEB)

    Tarahovsky, Yury S.; Koynova, Rumiana; MacDonald, Robert C. (Northwestern)

    2010-01-18

    DNA release from lipoplexes is an essential step during lipofection and is probably a result of charge neutralization by cellular anionic lipids. As a model system to test this possibility, fluorescence resonance energy transfer between DNA and lipid covalently labeled with Cy3 and BODIPY, respectively, was used to monitor the release of DNA from lipid surfaces induced by anionic liposomes. The separation of DNA from lipid measured this way was considerably slower and less complete than that estimated with noncovalently labeled DNA, and depends on the lipid composition of both lipoplexes and anionic liposomes. This result was confirmed by centrifugal separation of released DNA and lipid. X-ray diffraction revealed a clear correlation of the DNA release capacity of the anionic lipids with the interfacial curvature of the mesomorphic structures developed when the anionic and cationic liposomes were mixed. DNA release also correlated with the rate of fusion of anionic liposomes with lipoplexes. It is concluded that the tendency to fuse and the phase preference of the mixed lipid membranes are key factors for the rate and extent of DNA release. The approach presented emphasizes the importance of the lipid composition of both lipoplexes and target membranes and suggests optimal transfection may be obtained by tailoring lipoplex composition to the lipid composition of target cells.

  6. Carrying Capacity

    DEFF Research Database (Denmark)

    Schroll, Henning; Andersen, Jan; Kjærgård, Bente

    2012-01-01

    A spatial planning act was introduced inIndonesia 1992 and renewed in 2008. It emphasised the planning role of decentralised authorities. The spatial planning act covers both spatial and environmental issues. It defines the concept of carrying capacity and includes definitions of supportive....../cities. Four different sectors (water, food production, waste, and forests) were selected as core areas for decentralised spatial planning. Indicators for SCC and ACC were identified and assessed with regard to relevance and quantifiability. For each of the indicators selected, a legal threshold or guiding...... was introduced inIndonesia 1992 and renewed in 2008. It emphasised the planning role of decentralised authorities. The spatial planning act covers both spatial and environmental issues. It defines the concept of carrying capacity and includes definitions of supportive carrying capacity (SCC) and assimilative...

  7. Fuel assembly

    International Nuclear Information System (INIS)

    Yokota, Tokunobu.

    1990-01-01

    A fuel assembly used in a FBR type nuclear reactor comprises a plurality of fuel rods and a moderator guide member (water rod). A moderator exit opening/closing mechanism is formed at the upper portion of the moderator guide member for opening and closing a moderator exit. In the initial fuel charging operation cycle to the reactor, the moderator exit is closed by the moderator exit opening/closing mechanism. Then, voids are accumulated at the inner upper portion of the moderator guide member to harden spectrum and a great amount of plutonium is generated and accumulated in the fuel assembly. Further, in the fuel re-charging operation cycle, the moderator guide member is used having the moderator exit opened. In this case, voids are discharged from the moderator guide member to decrease the ratio, and the plutonium accumulated in the initial charging operation cycle is burnt. In this way, the fuel economy can be improved. (I.N.)

  8. Fuel assemblies

    International Nuclear Information System (INIS)

    Echigoya, Hironori; Nomata, Terumitsu.

    1983-01-01

    Purpose: To render the axial distribution relatively flat. Constitution: First nuclear element comprises a fuel can made of zircalloy i.e., the metal with less neutron absorption, which is filled with a plurality of UO 2 pellets and sealed by using a lower end plug, a plenum spring and an upper end plug by means of welding. Second fuel element is formed by substituting a part of the UO 2 pellets with a water tube which is sealed with water and has a space for allowing the heat expansion. The nuclear fuel assembly is constituted by using the first and second fuel elements together. In such a structure, since water reflects neutrons and decrease their leakage to increase the temperature, reactivity is added at the upper portion of the fuel assembly to thereby flatten the axial power distribution. Accordingly, stable operation is possible only by means of deep control rods while requiring no shallow control rods. (Sekiya, K.)

  9. Fuel assembly

    International Nuclear Information System (INIS)

    Kawai, Mitsuo.

    1988-01-01

    Purpose: To reduce the corrosion rate and suppress the increase of radioactive corrosion products in reactor water of nuclear fuel assemblies for use in BWR type reactors having spacer springs made of nickel based deposition reinforced type alloys. Constitution: Spacer rings made of nickel based deposition reinforced type alloy are incorporated and used as fuel assemblies after applying treatment of dipping and maintaining at high temperature water followed by heating in steams. Since this can remove the nickel leaching into reactor water at the initial stage, Co-58 as the radioactive corrosion products in the reactor water can be reduced, and the operation at in-service inspection or repairement can be facilitated to improve the working efficiency of the nuclear power plant. The dipping time is desirably more than 10 hours and more desirably more than 30 hours. (Horiuchi, T. )

  10. Fuel assembly

    International Nuclear Information System (INIS)

    Watanabe, Shoichi; Hirano, Yasushi.

    1998-01-01

    A one-half or more of entire fuel rods in a fuel assembly comprises MOX fuel rods containing less than 1wt% of burnable poisons, and at least a portion of the burnable poisons comprises gadolinium. Then, surplus reactivity at an initial stage of operation cycle is controlled to eliminate burnable poisons remained unburnt at a final stage, as well as increase thermal reactivity. In addition, the content of fission plutonium is determined to greater than the content of uranium 235, and fuel rods at corner portions are made not to incorporate burnable poisons. Fuel rods not containing burnable poisons are disposed at positions in adjacent with fuel rods facing to a water rod at one or two directions. Local power at radial center of the fuel assembly is increased to flatten the distortion of radial power distribution. (N.H.)

  11. General Assembly

    CERN Multimedia

    Staff Association

    2016-01-01

    5th April, 2016 – Ordinary General Assembly of the Staff Association! In the first semester of each year, the Staff Association (SA) invites its members to attend and participate in the Ordinary General Assembly (OGA). This year the OGA will be held on Tuesday, April 5th 2016 from 11:00 to 12:00 in BE Auditorium, Meyrin (6-2-024). During the Ordinary General Assembly, the activity and financial reports of the SA are presented and submitted for approval to the members. This is the occasion to get a global view on the activities of the SA, its financial management, and an opportunity to express one’s opinion, including taking part in the votes. Other points are listed on the agenda, as proposed by the Staff Council. Who can vote? Only “ordinary” members (MPE) of the SA can vote. Associated members (MPA) of the SA and/or affiliated pensioners have a right to vote on those topics that are of direct interest to them. Who can give his/her opinion? The Ordinary General Asse...

  12. Fuel assembly

    International Nuclear Information System (INIS)

    Ueda, Sei; Ando, Ryohei; Mitsutake, Toru.

    1995-01-01

    The present invention concerns a fuel assembly suitable to a BWR-type reactor and improved especially with the nuclear characteristic, heat performance, hydraulic performance, dismantling or assembling performance and economical property. A part of poison rods are formed as a large-diameter/multi-region poison rods having a larger diameter than a fuel rod. A large number of fuel rods are disposed surrounding a large diameter water rod and a group of the large-diameter/multi-region poison rods in adjacent with the water rod. The large-diameter water rod has a burnable poison at the tube wall portion. At least a portion of the large-diameter poison rods has a coolant circulation portion allowing coolants to circulate therethrough. Since the large-diameter poison rods are disposed at a position of high neutron fluxes, a large neutron multiplication factor suppression effect can be provided, thereby enabling to reduce the number of burnable poison rods relative to fuels. As a result, power peaking in the fuel assembly is moderated and a greater amount of plutonium can be loaded. In addition the flow of cooling water which tends to gather around the large diameter water rod can be controlled to improve cooling performance of fuels. (N.H.)

  13. 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

  14. Differences between Lipids Extracted from Five Species Are Not Sufficient To Explain Biomagnification of Nonpolar Organic Chemicals

    DEFF Research Database (Denmark)

    Jahnke, Annika; Holmbäck, Jan; Andersson, Rina Argelia

    2015-01-01

    headspace from spiked olive oil to determine their sorptive capacities. Lipids from seal blubber and pork bacon solely composed of triglycerides had capacities similar to that of olive oil; lipids from mussels, herring, and guillemot egg had quantifiable fractions of phospholipids and cholesterol and showed...... capacities reduced by factors of up to 2.3-fold. Generally, the sorptive capacities of the lipids were not elevated relative to the olive oil controls and are unlikely to explain a substantial part of biomagnification....

  15. A one-step in-situ assembly strategy to construct PEG@MOG-100-Fe shape-stabilized composite phase change material with enhanced storage capacity for thermal energy storage

    Science.gov (United States)

    Wang, Junyong; Andriamitantsoa, Radoelizo S.; Atinafu, Dimberu G.; Gao, Hongyi; Dong, Wenjun; Wang, Ge

    2018-03-01

    A novel in-situ assembly strategy has been developed to synthesis polyethylene glycol (PEG)@iron-benzenetricarboxylate metal-organic gel (MOG-100-Fe) shape-stabilized composite phase change materials by regulating metal-to-ligand ratio. The PEG@MOG-100-Fe was prepared by an ingenious introduction of PEG into the traditional sol-gel prepared MOG-100-Fe. The composite exhibited high heat storage density and thermal stability. The PEG loading content reached up to 92% without any leakage above its melting point. The heat storage density reaches to 152.88

  16. Atomistic Monte Carlo simulation of lipid membranes

    DEFF Research Database (Denmark)

    Wüstner, Daniel; Sklenar, Heinz

    2014-01-01

    Biological membranes are complex assemblies of many different molecules of which analysis demands a variety of experimental and computational approaches. In this article, we explain challenges and advantages of atomistic Monte Carlo (MC) simulation of lipid membranes. We provide an introduction...... into the various move sets that are implemented in current MC methods for efficient conformational sampling of lipids and other molecules. In the second part, we demonstrate for a concrete example, how an atomistic local-move set can be implemented for MC simulations of phospholipid monomers and bilayer patches...

  17. Fuel assembly

    International Nuclear Information System (INIS)

    Fujibayashi, Toru.

    1970-01-01

    Herein disclosed is a fuel assembly in which a fuel rod bundle is easily detachable by rotating a fuel rod fastener rotatably mounted to the upper surface of an upper tie-plate supporting a fuel bundle therebelow. A locking portion at the leading end of each fuel rod protrudes through the upper tie-plate and is engaged with or separated from the tie-plate by the rotation of the fastener. The removal of a desired fuel rod can therefore be remotely accomplished without the necessity of handling pawls, locking washers and nuts. (Owens, K.J.)

  18. Assembling consumption

    DEFF Research Database (Denmark)

    Assembling Consumption marks a definitive step in the institutionalisation of qualitative business research. By gathering leading scholars and educators who study markets, marketing and consumption through the lenses of philosophy, sociology and anthropology, this book clarifies and applies...... the investigative tools offered by assemblage theory, actor-network theory and non-representational theory. Clear theoretical explanation and methodological innovation, alongside empirical applications of these emerging frameworks will offer readers new and refreshing perspectives on consumer culture and market...... societies. This is an essential reading for both seasoned scholars and advanced students of markets, economies and social forms of consumption....

  19. Exerting Capacity.

    Science.gov (United States)

    Leger, J Michael; Phillips, Carolyn A

    2017-05-01

    Patient safety has been at the forefront of nursing research since the release of the Institute of Medicine's report estimating the number of preventable adverse events in hospital settings; yet no research to date has incorporated the perspectives of bedside nurses using classical grounded theory (CGT) methodology. This CGT study explored the perceptions of bedside registered nurses regarding patient safety in adult acute care hospitals. Data analysis used three techniques unique to CGT-the constant comparative method, coding, and memoing-to explore the values, realities, and beliefs of bedside nurses about patient safety. The analysis resulted in a substantive theory, Exerting Capacity, which explained how bedside nurses balance the demands of keeping their patients safe. Exerting Capacity has implications for health care organization leaders, nursing leaders, and bedside nurses; it also has indications for future research into the concept of patient safety.

  20. Formation of supported lipid bilayers of charged E. coli lipids on modified gold by vesicle fusion

    Directory of Open Access Journals (Sweden)

    Ileana F. Márquez

    2017-01-01

    Full Text Available We describe a simple way of fusing E. coli lipid vesicles onto a gold surface. Supported lipid bilayers on metal surfaces are interesting for several reasons: transducing a biological signal to an electric readout, using surface analytical tools such as Surface Plasmon Resonance (SPR, Infrared Reflection Absorption Spectroscopy, Neutron Reflectivity or Electrochemistry. The most widely used method to prepare supported lipid membranes is fusion of preexisting liposomes. It is quite efficient on hydrophilic surfaces such as glass, mica or SiO2, but vesicle fusion on metals and metal oxide surfaces (as gold, titanium oxide or indium tin oxide, remains a challenge, particularly for vesicles containing charged lipids, as is the case of bacterial lipids. We describe a simple method based on modifying the gold surface with a charged mercaptopropionic acid self-assembled monolayer and liposomes partially solubilized with detergent. The formed bilayers were characterized using a Quartz Crystal Microbalance with dissipation (QCM-D and Atomic Force Microscopy (AFM. Some advantages of this protocol are that the stability of the self-assembled monolayer allows for repeated use of the substrate after detergent removal of the bilayer and that the amount of detergent required for optimal fusion can be determined previously using the lipid-detergent solubility curve.

  1. Effects of self-carbon dioxide-generation material for active packaging on pH, water-holding capacity, meat color, lipid oxidation and microbial growth in beef during cold storage.

    Science.gov (United States)

    Lee, Seung-Jae; Lee, Seung Yun; Kim, Gap-Don; Kim, Geun-Bae; Jin, Sang Keun; Hur, Sun Jin

    2017-08-01

    Active packaging refers to the mixing of additive agents into packaging materials with the purpose of maintaining or extending food product quality and shelf life. The aim of this study was to develop an easy and cheap active packaging for beef. Beef loin samples were divided into three packaging groups (C, ziplock bag packaging; T1, vacuum packaging; T2, active packaging) and stored at 4 °C for 21 days. The water-holding capacity was significantly (P packaging using self-CO 2 -generation materials can extend the shelf life similarly to that observed with vacuum packaging, and that the active packaging method can improve the quality characteristics of beef during cold storage. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  2. Fuel assembly

    International Nuclear Information System (INIS)

    Kurihara, Kunitoshi; Azekura, Kazuo.

    1992-01-01

    In a reactor core of a heavy water moderated light water cooled pressure tube type reactor, no sufficient effects have been obtained for the transfer width to a negative side of void reactivity change in a region of a great void coefficient. Then, a moderation region divided into upper and lower two regions is disposed at the central portion of a fuel assembly. Coolants flown into the lower region can be discharged to the cooling region from an opening disposed at the upper end portion of the lower region. Light water flows from the lower region of the moderator region to the cooling region of the reactor core upper portion, to lower the void coefficient. As a result, the reactivity performance at low void coefficient, i.e., a void reaction rate is transferred to the negative side. Thus, this flattens the power distribution in the fuel assembly, increases the thermal margin and enables rapid operaiton and control of the reactor core, as well as contributes to the increase of fuel burnup ratio and reduction of the fuel cycle cost. (N.H.)

  3. Fuel assembly

    International Nuclear Information System (INIS)

    Chaki, Masao; Nishida, Koji; Karasawa, Hidetoshi; Kanazawa, Toru; Orii, Akihito; Nagayoshi, Takuji; Kashiwai, Shin-ichi; Masuhara, Yasuhiro

    1998-01-01

    The present invention concerns a fuel assembly, for a BWR type nuclear reactor, comprising fuel rods in 9 x 9 matrix. The inner width of the channel box is about 132mm and the length of the fuel rods which are not short fuel rods is about 4m. Two water rods having a circular cross section are arranged on a diagonal line in a portion of 3 x 3 matrix at the center of the fuel assembly, and two fuel rods are disposed at vacant spaces, and the number of fuel rods is 74. Eight fuel rods are determined as short fuel rods among 74 fuel rods. Assuming the fuel inventory in the short fuel rod as X(kg), and the fuel inventory in the fuel rods other than the short fuel rods as Y(kg), X and Y satisfy the relation: X + Y ≥ 173m, Y ≤ - 9.7X + 292, Y ≤ - 0.3X + 203 and X > 0. Then, even when the short fuel rods are used, the fuel inventory is increased and fuel economy can be improved. (I.N.)

  4. Fuel assembly

    International Nuclear Information System (INIS)

    Fushimi, Atsushi; Shimada, Hidemitsu; Aoyama, Motoo; Nakajima, Junjiro

    1998-01-01

    In a fuel assembly for an n x n lattice-like BWR type reactor, n is determined to 9 or greater, and the enrichment degree of plutonium is determined to 4.4% by weight or less. Alternatively, n is determined to 10 or greater, and the enrichment degree of plutonium is determined to 5.2% by weight or less. An average take-out burnup degree is determined to 39GWd/t or less, and the matrix is determined to 9 x 9 or more, or the average take-out burnup degree is determined to 51GWd/t, and the matrix is determined to 10 x 10 or more and the increase of the margin of the maximum power density obtained thereby is utilized for the compensation of the increase of distortion of power distribution due to decrease of the kinds of plutonium enrichment degree, thereby enabling to reduce the kind of the enrichment degree of MOX fuel rods to one. As a result, the manufacturing step for fuel pellets can be simplified to reduce the manufacturing cost for MOX fuel assemblies. (N.H.)

  5. General Assembly

    CERN Multimedia

    Staff Association

    2015-01-01

    Mardi 5 mai à 11 h 00 Salle 13-2-005 Conformément aux statuts de l’Association du personnel, une Assemblée générale ordinaire est organisée une fois par année (article IV.2.1). Projet d’ordre du jour : 1- Adoption de l’ordre du jour. 2- Approbation du procès-verbal de l’Assemblée générale ordinaire du 22 mai 2014. 3- Présentation et approbation du rapport d’activités 2014. 4- Présentation et approbation du rapport financier 2014. 5- Présentation et approbation du rapport des vérificateurs aux comptes pour 2014. 6- Programme 2015. 7- Présentation et approbation du projet de budget 2015 et taux de cotisation pour 2015. 8- Pas de modifications aux Statuts de l'Association du personnel proposée. 9- Élections des membres de la Commission é...

  6. General Assembly

    CERN Multimedia

    Staff Association

    2017-01-01

    Conformément aux statuts de l’Association du personnel, une Assemblée générale ordinaire est organisée une fois par année (article IV.2.1). Projet d’ordre du jour : Adoption de l’ordre du jour. Approbation du procès-verbal de l’Assemblée générale ordinaire du 5 avril 2016. Présentation et approbation du rapport d’activités 2016. Présentation et approbation du rapport financier 2016. Présentation et approbation du rapport des vérificateurs aux comptes pour 2016. Programme de travail 2017. Présentation et approbation du projet de budget 2017 Approbation du taux de cotisation pour 2018. Modifications aux Statuts de l'Association du personnel proposées. Élections des membres de la Commission électorale. Élections des vérifica...

  7. General Assembly

    CERN Multimedia

    Staff Association

    2016-01-01

    Mardi 5 avril à 11 h 00 BE Auditorium Meyrin (6-2-024) Conformément aux statuts de l’Association du personnel, une Assemblée générale ordinaire est organisée une fois par année (article IV.2.1). Projet d’ordre du jour : Adoption de l’ordre du jour. Approbation du procès-verbal de l’Assemblée générale ordinaire du 5 mai 2015. Présentation et approbation du rapport d’activités 2015. Présentation et approbation du rapport financier 2015. Présentation et approbation du rapport des vérificateurs aux comptes pour 2015. Programme de travail 2016. Présentation et approbation du projet de budget 2016 Approbation du taux de cotisation pour 2017. Modifications aux Statuts de l'Association du personnel proposée. Élections des membres de la Commissio...

  8. General assembly

    CERN Multimedia

    Staff Association

    2015-01-01

    Mardi 5 mai à 11 h 00 Salle 13-2-005 Conformément aux statuts de l’Association du personnel, une Assemblée générale ordinaire est organisée une fois par année (article IV.2.1). Projet d’ordre du jour : Adoption de l’ordre du jour. Approbation du procès-verbal de l’Assemblée générale ordinaire du 22 mai 2014. Présentation et approbation du rapport d’activités 2014. Présentation et approbation du rapport financier 2014. Présentation et approbation du rapport des vérificateurs aux comptes pour 2014. Programme 2015. Présentation et approbation du projet de budget 2015 et taux de cotisation pour 2015. Pas de modifications aux Statuts de l'Association du personnel proposée. Élections des membres de la Commission électorale. &am...

  9. Fuel assembly

    International Nuclear Information System (INIS)

    Nomata, Terumitsu.

    1993-01-01

    Among fuel pellets to be loaded to fuel cans of a fuel assembly, fuel pellets having a small thermal power are charged in a region from the end of each of spacers up to about 50mm on the upstream of coolants that flow vertically at the periphery of fuel rods. Coolants at the periphery of fuel rods are heated by the heat generation, to result in voids. However, since cooling effect on the upstream of the spacers is low due to influences of the spacers. Further, since the fuel pellets disposed in the upstream region have small thermal power, a void coefficient is not increased. Even if a thermal power exceeding cooling performance should be generated, there is no worry of causing burnout in the upstream region. Even if burnout should be caused, safety margin and reliability relative to burnout are improved, to increase an allowable thermal power, thereby enabling to improve integrity and reliability of fuel rods and fuel assemblies. (N.H.)

  10. Nanostructured self-assembly materials from neat and aqueous solutions of C18 lipid pro-drug analogues of Capecitabine—a chemotherapy agent. Focus on nanoparticulate cubosomes™ of the oleyl analogue

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Xiaojuan; Moghaddam, Minoo J.; Sagnella, Sharon M.; Conn, Charlotte E.; Mulet, Xavier; Danon, Stephen J.; Waddington, Lynne J.; Drummond, Calum J.

    2014-09-24

    A series of prodrug analogues based on the established chemotherapy agent, 5-fluorouracil, have been prepared and characterized. C18 alkyl and alkenyl chains with increasing degree of unsaturation were attached to the N4 position of the 5-fluorocytosine (5-FC) base via a carbamate bond. Physicochemical characterization of the prodrug analogues was carried out using a combination of differential scanning calorimetry, cross-polarized optical microscopy, X-ray diffraction and small-angle X-ray scattering. The presence of a monounsaturated oleyl chain was found to promote lyotropic liquid crystalline phase formation in excess water with a fluid lamellar phase observed at room temperature and one or more bicontinuous cubic phases at 37 °C. The bulk phase was successfully dispersed into liposomes or cubosomes at room and physiological temperature respectively. In vitro toxicity of the nanoparticulate 5-FCOle dispersions was evaluated against several normal and cancer cell types over a 48 h period and exhibited an IC50 of -100 μM against all cell types. The in vivo efficacy of 5-FCOle cubosomes was assessed against the highly aggressive mouse 4T1 breast cancer model and compared to Capecitabine (a water-soluble commercially available 5-FU prodrug) delivered at the same dosages. After 21 days of treatment, the 0.5 mmol 5-FCOle treatment group exhibited a significantly smaller average tumour volume than all other treatment groups including Capecitabine at similar dosage. These results exemplify the potential of self-assembled amphiphile prodrugs for delivery of bioactives in vivo.

  11. Capacity Building

    International Nuclear Information System (INIS)

    Molloy, Brian; Mallick, Shahid

    2014-01-01

    Outcomes & Recommendations: • Significant increase needed in the nuclear workforce both to replace soon-to-retire current generation and to staff large numbers of new units planned • Key message, was the importance of an integrated approach to workforce development. • IAEA and other International Organisations were asked to continue to work on Knowledge Management, Networks and E&T activities • IAEA requested to conduct Global Survey of HR needs – survey initiated but only 50% of operating countries (30% of capacity) took part, so results inconclusive

  12. Lipid Raft, Regulator of Plasmodesmal Callose Homeostasis

    Directory of Open Access Journals (Sweden)

    Arya Bagus Boedi Iswanto

    2017-04-01

    Full Text Available Abstract: The specialized plasma membrane microdomains known as lipid rafts are enriched by sterols and sphingolipids. Lipid rafts facilitate cellular signal transduction by controlling the assembly of signaling molecules and membrane protein trafficking. Another specialized compartment of plant cells, the plasmodesmata (PD, which regulates the symplasmic intercellular movement of certain molecules between adjacent cells, also contains a phospholipid bilayer membrane. The dynamic permeability of plasmodesmata (PDs is highly controlled by plasmodesmata callose (PDC, which is synthesized by callose synthases (CalS and degraded by β-1,3-glucanases (BGs. In recent studies, remarkable observations regarding the correlation between lipid raft formation and symplasmic intracellular trafficking have been reported, and the PDC has been suggested to be the regulator of the size exclusion limit of PDs. It has been suggested that the alteration of lipid raft substances impairs PDC homeostasis, subsequently affecting PD functions. In this review, we discuss the substantial role of membrane lipid rafts in PDC homeostasis and provide avenues for understanding the fundamental behavior of the lipid raft–processed PDC.

  13. Lipid Raft, Regulator of Plasmodesmal Callose Homeostasis.

    Science.gov (United States)

    Iswanto, Arya Bagus Boedi; Kim, Jae-Yean

    2017-04-03

    A bstract: The specialized plasma membrane microdomains known as lipid rafts are enriched by sterols and sphingolipids. Lipid rafts facilitate cellular signal transduction by controlling the assembly of signaling molecules and membrane protein trafficking. Another specialized compartment of plant cells, the plasmodesmata (PD), which regulates the symplasmic intercellular movement of certain molecules between adjacent cells, also contains a phospholipid bilayer membrane. The dynamic permeability of plasmodesmata (PDs) is highly controlled by plasmodesmata callose (PDC), which is synthesized by callose synthases (CalS) and degraded by β-1,3-glucanases (BGs). In recent studies, remarkable observations regarding the correlation between lipid raft formation and symplasmic intracellular trafficking have been reported, and the PDC has been suggested to be the regulator of the size exclusion limit of PDs. It has been suggested that the alteration of lipid raft substances impairs PDC homeostasis, subsequently affecting PD functions. In this review, we discuss the substantial role of membrane lipid rafts in PDC homeostasis and provide avenues for understanding the fundamental behavior of the lipid raft-processed PDC.

  14. Fuel assembly

    International Nuclear Information System (INIS)

    Ueda, Makoto; Ogiya, Shunsuke.

    1989-01-01

    For improving the economy of a BWR type reactor by making the operation cycle longer, the fuel enrichment degree has to be increased further. However, this makes the subcriticality shallower in the upper portion of the reactor core, to bring about a possibility that the reactor shutdown becomes impossible. In the present invention, a portion of fuel rod is constituted as partial length fuel rods (P-fuel rods) in which the entire stack length in the effective portion is made shorter by reducing the concentration of fissionable materials in the axial portion. A plurality of moderator rods are disposed at least on one diagonal line of a fuel assembly and P-fuel rods are arranged at a position put between the moderator rods. This makes it possible to reactor shutdown and makes the axial power distribution satisfactory even if the fuel enrichment degree is increased. (T.M.)

  15. Fuel assembly

    International Nuclear Information System (INIS)

    Bando, Masaru.

    1993-01-01

    As neutron irradiation progresses on a fuel assembly of an FBR type reactor, a strong force is exerted to cause ruptures if the arrangement of fuel elements is not displaced, whereas the fuel elements may be brought into direct contact with each other not by way of spacers to cause burning damages if the arrangement is displaced. In the present invention, the circumference of fuel elements arranged in a normal triangle lattice is surrounded by a wrapper tube having a hexagonal cross section, wire spacers are wound therearound, and deformable spacers are distributed to optional positions for fuel elements in the wrapper tube. Interaction between the fuel elements caused by irradiation is effectively absorbed, thereby enabling to delay the occurrence of the rupture and burning damages of the elements. (N.H.)

  16. Fuel assembly

    International Nuclear Information System (INIS)

    Ueda, Makoto.

    1991-01-01

    In a fuel assembly in which spectral shift type moderator guide members are arranged, the moderator guide member has a flow channel resistance member, that provides flow resistance against the moderators, in the upstream of a moderator flowing channel, by which the ratio of removing coolants is set greater at the upstream than downstream. With such a constitution, the void distribution increasing upward in the channel box except for the portion of the moderator guide member is moderated by the increase of the area of the void region that expands downward in the guide member. Accordingly, the axial power distribution is flattened throughout the operation cycle and excess distortion is eliminated to improve the fuel integrity. (T.M.)

  17. Fuel assembly

    International Nuclear Information System (INIS)

    Wataumi, Kazutoshi; Tajiri, Hiroshi.

    1992-01-01

    In a fuel assembly of a BWR type reactor, a pellet to be loaded comprises an external layer of fissile materials containing burnable poisons and an internal layer of fissile materials not containing burnable poison. For example, there is provided a dual type pellet comprising an external layer made of UO 2 incorporated with Gd 2 O 3 at a predetermined concentration as the burnable poisons and an internal layer made of UO 2 not containing Gd 2 O 3 . The amount of the burnable poisons required for predetermined places is controlled by the thickness of the ring of the external layer. This can dissipate an unnecessary poisoning effect at the final stage of the combustion cycle. Further, since only one or a few kinds of powder mixture of the burnable poisons and the fissile materials is necessary, production and product control can be facilitated. (I.N.)

  18. Fuel assembly

    International Nuclear Information System (INIS)

    Ishibashi, Yoko; Aoyama, Motoo; Oyama, Jun-ichi.

    1995-01-01

    Burnable poison-incorporating fuel rods of a first group are disposed in a region in adjacent with a water rod having a large diameter (neutron moderator rod) disposed to the central portion of a fuel assembly. Burnable poison-incorporating fuel rods of a second group are disposed to a region other than peripheral zone in adjacent with a channel box and corners positioned at an inner zone, in adjacent with the channel box. The average concentration of burnable poisons of the burnable poison-incorporating fuel rods of the first group is made greater than that of the second group. With such a constitution, when the burnable poisons of the first group are burnt out, the burnable poisons of the second group are also burnt out at the same time. Accordingly, an amount of burnable poisons left unburnt at the final stage of the operation cycle is reduced, to improve the reactivity. This can improve the economical property. (I.N.)

  19. Fuel assemblies

    International Nuclear Information System (INIS)

    Yoshioka, Ritsuo.

    1983-01-01

    Purpose: To improve the operation performance of a BWR type reactor by improving the distribution of the uranium enrichment and the incorporation amount of burnable poisons in fuel assemblies. Constitution: The average enrichment of uranium 235 is increased in the upper portion as compared with that in the lower portion, while the incorporation amount of burnable poisons is increased in an upper portion as compared with that in the lower portion. The difference in the incorporation amount of the burnable poisons between the upper and lower portions is attained by charging two kinds of fuel rods; the ones incorporated with the burnable poisons over the entire length and the others incorporated with the burnable poisons only in the upper portions. (Seki, T.)

  20. Characterization of the Lateral Distribution of Fluorescent Lipid in Binary-Constituent Lipid Monolayers by Principal Component Analysis

    Directory of Open Access Journals (Sweden)

    István P. Sugár

    2010-01-01

    Full Text Available Lipid lateral organization in binary-constituent monolayers consisting of fluorescent and nonfluorescent lipids has been investigated by acquiring multiple emission spectra during measurement of each force-area isotherm. The emission spectra reflect BODIPY-labeled lipid surface concentration and lateral mixing with different nonfluorescent lipid species. Using principal component analysis (PCA each spectrum could be approximated as the linear combination of only two principal vectors. One point on a plane could be associated with each spectrum, where the coordinates of the point are the coefficients of the linear combination. Points belonging to the same lipid constituents and experimental conditions form a curve on the plane, where each point belongs to a different mole fraction. The location and shape of the curve reflects the lateral organization of the fluorescent lipid mixed with a specific nonfluorescent lipid. The method provides massive data compression that preserves and emphasizes key information pertaining to lipid distribution in different lipid monolayer phases. Collectively, the capacity of PCA for handling large spectral data sets, the nanoscale resolution afforded by the fluorescence signal, and the inherent versatility of monolayers for characterization of lipid lateral interactions enable significantly enhanced resolution of lipid lateral organizational changes induced by different lipid compositions.

  1. Homeoviscous adaptation and the regulation of membrane lipids

    DEFF Research Database (Denmark)

    Ernst, Robert; Ejsing, Christer S; Antonny, Bruno

    2016-01-01

    Biological membranes are complex and dynamic assemblies of lipids and proteins. Poikilothermic organisms including bacteria, fungi, reptiles, and fish do not control their body temperature and must adapt their membrane lipid composition in order to maintain membrane fluidity in the cold. This ada......Biological membranes are complex and dynamic assemblies of lipids and proteins. Poikilothermic organisms including bacteria, fungi, reptiles, and fish do not control their body temperature and must adapt their membrane lipid composition in order to maintain membrane fluidity in the cold....... This adaptive response was termed homeoviscous adaptation and has been frequently studied with a specific focus on the acyl chain composition of membrane lipids. Massspectrometry-based lipidomics can nowadays provide more comprehensive insights into the complexity of lipid remodeling during adaptive responses...... such as neurons maintain unique lipid compositions with specific physicochemical properties. To date little is known about the sensory mechanisms regulating the acyl chain profile in such specialized cells or during adaptive responses. Here we summarize our current understanding of lipid metabolic networks...

  2. Capacity Ten-Seven

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-05-04

    The study was initiated to assemble UK solar experts who would define the parameters for the design of solar cell process plant with a capacity of about 10MWp per annum and establish the optimum substrate size, cell configuration and junction structure and show that these characteristics are suited to high volume low cost production. The study focused on proven materials and techniques rather than on innovative materials and processes. Peak production should deliver panels at a cost of less than $1 per peak watt. The study was reported under the headings of fundamental studies, front contact deposition, semiconductor deposition, rear contact deposition, cell isolation and initial design study. Since much of the work is commercially sensitive, not all findings are divulged in the report. The work, which achieved all its targets, was carried out by ICP Solar Technologies UK Ltd under contract to the DTI.

  3. Single Lipid Molecule Dynamics on Supported Lipid Bilayers with Membrane Curvature

    Directory of Open Access Journals (Sweden)

    Philip P. Cheney

    2017-03-01

    Full Text Available The plasma membrane is a highly compartmentalized, dynamic material and this organization is essential for a wide variety of cellular processes. Nanoscale domains allow proteins to organize for cell signaling, endo- and exocytosis, and other essential processes. Even in the absence of proteins, lipids have the ability to organize into domains as a result of a variety of chemical and physical interactions. One feature of membranes that affects lipid domain formation is membrane curvature. To directly test the role of curvature in lipid sorting, we measured the accumulation of two similar lipids, 1,2-Dihexadecanoyl-sn-glycero-3-phosphoethanolamine (DHPE and hexadecanoic acid (HDA, using a supported lipid bilayer that was assembled over a nanopatterned surface to obtain regions of membrane curvature. Both lipids studied contain 16 carbon, saturated tails and a head group tag for fluorescence microscopy measurements. The accumulation of lipids at curvatures ranging from 28 nm to 55 nm radii was measured and fluorescein labeled DHPE accumulated more than fluorescein labeled HDA at regions of membrane curvature. We then tested whether single biotinylated DHPE molecules sense curvature using single particle tracking methods. Similar to groups of fluorescein labeled DHPE accumulating at curvature, the dynamics of single molecules of biotinylated DHPE was also affected by membrane curvature and highly confined motion was observed.

  4. Influences of the Structure of Lipids on Thermal Stability of Lipid Membranes

    International Nuclear Information System (INIS)

    Hai Nan-Nan; Zhou Xin; Li Ming

    2015-01-01

    The binding free energy (BFE) of lipid to lipid bilayer is a critical factor to determine the thermal or mechanical stability of the bilayer. Although the molecular structure of lipids has significant impacts on BFE of the lipid, there lacks a systematic study on this issue. In this paper we use coarse-grained molecular dynamics simulation to investigate this problem for several typical phospholipids. We find that both the tail length and tail unsaturation can significantly affect the BFE of lipids but in opposite way, namely, BFE decreases linearly with increasing length, but increases linearly with addition of unsaturated bonds. Inspired by the specific structure of cholesterol which is a crucial component of biomembrane, we also find that introduction of carbo-ring-like structures to the lipid tail or to the bilayer may greatly enhance the stability of the bilayer. Our simulation also shows that temperature can influence the bilayer stability and this effect can be significant when the bilayer undergoes phase transition. These results may be helpful to the design of liposome or other self-assembled lipid systems. (paper)

  5. 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...

  6. Incorporation of liquid lipid in lipid nanoparticles for ocular drug delivery enhancement

    International Nuclear Information System (INIS)

    Shen Jie; Sun Minjie; Ping Qineng; Ying Zhi; Liu Wen

    2010-01-01

    The present work investigates the effect of liquid lipid incorporation on the physicochemical properties and ocular drug delivery enhancement of nanostructured lipid carriers (NLCs) and attempts to elucidate in vitro and in vivo the potential of NLCs for ocular drug delivery. The CyA-loaded or fluorescein-marked nanocarriers composed of Precifac ATO 5 and Miglyol 840 (as liquid lipid) were prepared by melting-emulsion technology, and the physicochemical properties of nanocarriers were determined. The uptake of nanocarriers by human corneal epithelia cell lines (SDHCEC) and rabbit cornea was examined. Ex vivo fluorescence imaging was used to investigate the ocular distribution of nanocarriers. The in vitro cytotoxicity and in vivo acute tolerance were evaluated. The higher drug loading capacity and improved in vitro sustained drug release behavior of lipid nanoparticles was found with the incorporation of liquid lipid in lipid nanoparticles. The uptake of nanocarriers by the SDHCEC was increased with the increase in liquid lipid loading. The ex vivo fluorescence imaging of the ocular tissues indicated that the liquid lipid incorporation could improve the ocular retention and penetration of ocular therapeutics. No alternation was macroscopically observed in vivo after ocular surface exposure to nanocarriers. These results indicated that NLC was a biocompatible and potential nanocarrier for ocular drug delivery enhancement.

  7. Incorporation of liquid lipid in lipid nanoparticles for ocular drug delivery enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Shen Jie; Sun Minjie; Ping Qineng; Ying Zhi; Liu Wen, E-mail: Pingqn2004@yahoo.com.cn [School of Pharmacy, China Pharmaceutical University, 24 Tongjia Xiang, Nanjing (China)

    2010-01-15

    The present work investigates the effect of liquid lipid incorporation on the physicochemical properties and ocular drug delivery enhancement of nanostructured lipid carriers (NLCs) and attempts to elucidate in vitro and in vivo the potential of NLCs for ocular drug delivery. The CyA-loaded or fluorescein-marked nanocarriers composed of Precifac ATO 5 and Miglyol 840 (as liquid lipid) were prepared by melting-emulsion technology, and the physicochemical properties of nanocarriers were determined. The uptake of nanocarriers by human corneal epithelia cell lines (SDHCEC) and rabbit cornea was examined. Ex vivo fluorescence imaging was used to investigate the ocular distribution of nanocarriers. The in vitro cytotoxicity and in vivo acute tolerance were evaluated. The higher drug loading capacity and improved in vitro sustained drug release behavior of lipid nanoparticles was found with the incorporation of liquid lipid in lipid nanoparticles. The uptake of nanocarriers by the SDHCEC was increased with the increase in liquid lipid loading. The ex vivo fluorescence imaging of the ocular tissues indicated that the liquid lipid incorporation could improve the ocular retention and penetration of ocular therapeutics. No alternation was macroscopically observed in vivo after ocular surface exposure to nanocarriers. These results indicated that NLC was a biocompatible and potential nanocarrier for ocular drug delivery enhancement.

  8. Fuel assembly

    International Nuclear Information System (INIS)

    Hirukawa, Koji; Sakurada, Koichi.

    1992-01-01

    In a fuel assembly for a BWR type reactor, water rods or water crosses are disposed between fuel rods, and a value with a spring is disposed at the top of the coolant flow channel thereof, which opens a discharge port when pressure is increased to greater than a predetermined value. Further, a control element for the amount of coolant flow rate is inserted retractable to a control element guide tube formed at the lower portion of the water rod or the water cross. When the amount of control elements inserted to the control element guide tube is small and the inflown coolant flow rate is great, the void coefficient at the inside of the water rod is less than 5%. On the other hand, when the control elements are inserted, the flow resistance is increased, so that the void coefficient in the water rod is greater than 80%. When the pressure in the water rod is increased, the valve with the spring is raised to escape water or steams. Then, since the variation range of the change of the void coefficient can be controlled reliably by the amount of the control elements inserted, and nuclear fuel materials can be utilized effectively. (N.H.)

  9. Fuel assembly

    International Nuclear Information System (INIS)

    Hiraiwa, Koji; Ueda, Makoto

    1989-01-01

    In a fuel assembly used for a light water cooled reactor such as a BWR type reactor, a water rod is divided axially into an upper outer tube and a lower outer tube by means of a plug disposed from the lower end of a water rod to a position 1/4 - 1/2 of the entire length for the water rod. Inlet apertures and exit apertures for moderators are respectively perforated for the divided outer tube and upper and lower portions. Further, an upper inner tube with less neutron irradiation growing amount than the outer tube is perforated on the plug in the outer tube, while a lower inner tube with greater neutron irradiation growing amount than the outer tube is suspended from the lower surface of the plug in the outer tube. Then, the opening area for the exit apertures disposed to the upper outer tube and the lower outer tube is controlled depending on the difference of the neutron irradiation growing amount between the upper inner tube and the upper outer tube, and the difference of the neutron irradiation growing amount between the lower inner tube and the lower outer tube. This enables effective spectral shift operation and improve the fuel economy. (T.M.)

  10. Fuel assembly

    International Nuclear Information System (INIS)

    Yamazaki, Hajime.

    1995-01-01

    In a fuel assembly having fuel rods of different length, fuel pellets of mixed oxides of uranium and plutonium are loaded to a short fuel rod. The volume ratio of a pellet-loaded portion to a plenum portion of the short fuel rod is made greater than the volume ratio of a fuel rod to which uranium fuel pellets are loaded. In addition, the volume of the plenum portion of the short fuel rod is set greater depending on the plutonium content in the loaded fuel pellets. MOX fuel pellets are loaded on the short fuel rods having a greater degree of freedom relevant to the setting for the volume of the plenum portion compared with that of a long rod fuel, and the volume of the plenum portion is ensured greater depending on the plutonium content. Even if a large amount of FP gas and He gas are discharged from the MOX fuels compared with that from the uranium fuels, the internal pressure of the MOX fuel rod during operation is maintained substantially identical with that of the uranium fuel rod, so that a risk of generating excess stresses applied to the fuel cladding tubes and rupture of fuels are greatly reduced. (N.H.)

  11. Fuel assembly

    International Nuclear Information System (INIS)

    Nakajima, Akiyoshi; Bessho, Yasunori; Aoyama, Motoo; Koyama, Jun-ichi; Hirakawa, Hiromasa; Yamashita, Jun-ichi; Hayashi, Tatsuo

    1998-01-01

    In a fuel assembly of a BWR type reactor in which a water rod of a large diameter is disposed at the central portion, the cross sectional area perpendicular to the axial direction comprises a region a of a fuel rod group facing to a wide gap water region to which a control rod is inserted, a region b of a fuel rod group disposed on the side of the wide gap water region other than the region a, a region d of a fuel rod group facing to a narrow gap water region and a region c of a fuel rod group disposed on the side of the narrow gap water region other than the region d. When comparing an amount of fission products contained in the four regions relative to that in the entire regions and average enrichment degrees of fuel rods for the four regions, the relative amount and the average enrichment degree of the fuel rod group of the region a is minimized, and the relative amount and the average enrichment degree of the fuel rod group in the region b is maximized. Then, reactor shut down margin during cold operation can be improved while flattening the power in the cross section perpendicular to the axial direction. (N.H.)

  12. The collaborative work of droplet assembly.

    Science.gov (United States)

    Chen, Xiao; Goodman, Joel M

    2017-10-01

    Three proteins have been implicated in the assembly of cytoplasmic lipid droplets: seipin, FIT2, and perilipin. This review examines the current theories of seipin function as well as the evidence for the involvement of all three proteins in droplet biogenesis, and ends with a proposal of how they collaborate to regulate the formation of droplets. This article is part of a Special Issue entitled: Recent Advances in Lipid Droplet Biology edited by Rosalind Coleman and Matthijs Hesselink. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. 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...

  14. Mobius Assembly: A versatile Golden-Gate framework towards universal DNA assembly.

    Directory of Open Access Journals (Sweden)

    Andreas I Andreou

    Full Text Available Synthetic biology builds upon the foundation of engineering principles, prompting innovation and improvement in biotechnology via a design-build-test-learn cycle. A community-wide standard in DNA assembly would enable bio-molecular engineering at the levels of predictivity and universality in design and construction that are comparable to other engineering fields. Golden Gate Assembly technology, with its robust capability to unidirectionally assemble numerous DNA fragments in a one-tube reaction, has the potential to deliver a universal standard framework for DNA assembly. While current Golden Gate Assembly frameworks (e.g. MoClo and Golden Braid render either high cloning capacity or vector toolkit simplicity, the technology can be made more versatile-simple, streamlined, and cost/labor-efficient, without compromising capacity. Here we report the development of a new Golden Gate Assembly framework named Mobius Assembly, which combines vector toolkit simplicity with high cloning capacity. It is based on a two-level, hierarchical approach and utilizes a low-frequency cutter to reduce domestication requirements. Mobius Assembly embraces the standard overhang designs designated by MoClo, Golden Braid, and Phytobricks and is largely compatible with already available Golden Gate part libraries. In addition, dropout cassettes encoding chromogenic proteins were implemented for cost-free visible cloning screening that color-code different cloning levels. As proofs of concept, we have successfully assembled up to 16 transcriptional units of various pigmentation genes in both operon and multigene arrangements. Taken together, Mobius Assembly delivers enhanced versatility and efficiency in DNA assembly, facilitating improved standardization and automation.

  15. Atomistic Monte Carlo Simulation of Lipid Membranes

    Directory of Open Access Journals (Sweden)

    Daniel Wüstner

    2014-01-01

    Full Text Available Biological membranes are complex assemblies of many different molecules of which analysis demands a variety of experimental and computational approaches. In this article, we explain challenges and advantages of atomistic Monte Carlo (MC simulation of lipid membranes. We provide an introduction into the various move sets that are implemented in current MC methods for efficient conformational sampling of lipids and other molecules. In the second part, we demonstrate for a concrete example, how an atomistic local-move set can be implemented for MC simulations of phospholipid monomers and bilayer patches. We use our recently devised chain breakage/closure (CBC local move set in the bond-/torsion angle space with the constant-bond-length approximation (CBLA for the phospholipid dipalmitoylphosphatidylcholine (DPPC. We demonstrate rapid conformational equilibration for a single DPPC molecule, as assessed by calculation of molecular energies and entropies. We also show transition from a crystalline-like to a fluid DPPC bilayer by the CBC local-move MC method, as indicated by the electron density profile, head group orientation, area per lipid, and whole-lipid displacements. We discuss the potential of local-move MC methods in combination with molecular dynamics simulations, for example, for studying multi-component lipid membranes containing cholesterol.

  16. SAXS Study of Sterically Stabilized Lipid Nanocarriers Functionalized by DNA

    Science.gov (United States)

    Angelov, Borislav; Angelova, Angelina; Filippov, Sergey; Karlsson, Göran; Terrill, Nick; Lesieur, Sylviane; Štěpánek, Petr

    2012-03-01

    The structure of novel spontaneously self-assembled plasmid DNA/lipid complexes is investigated by means of synchrotron radiation small-angle X-ray scattering (SAXS) and Cryo-TEM imaging. Liquid crystalline (LC) hydrated lipid systems are prepared using the non-ionic lipids monoolein and DOPE-PEG2000 and the cationic amphiphile CTAB. The employed plasmid DNA (pDNA) is encoding for the human protein brain-derived neurotrophic factor (BDNF). A coexistence of nanoparticulate objects with different LC inner organizations is established. A transition from bicontinuous membrane sponges, cubosome intermediates and unilamelar liposomes to multilamellar vesicles, functionalized by pDNA, is favoured upon binding and compaction of pBDNF onto the cationic PEGylated lipid nanocarriers. The obtained sterically stabilized multicompartment nanoobjects, with confined supercoiled plasmid DNA (pBDNF), are important in the context of multicompartment lipid nanocarriers of interest for gene therapy of neurodegenerative diseases.

  17. SAXS Study of Sterically Stabilized Lipid Nanocarriers Functionalized by DNA

    International Nuclear Information System (INIS)

    Angelov, Borislav; Filippov, Sergey; Štepánek, Petr; Angelova, Angelina; Lesieur, Sylviane; Karlsson, Göran; Terrill, Nick

    2012-01-01

    The structure of novel spontaneously self-assembled plasmid DNA/lipid complexes is investigated by means of synchrotron radiation small-angle X-ray scattering (SAXS) and Cryo-TEM imaging. Liquid crystalline (LC) hydrated lipid systems are prepared using the non-ionic lipids monoolein and DOPE-PEG 2000 and the cationic amphiphile CTAB. The employed plasmid DNA (pDNA) is encoding for the human protein brain-derived neurotrophic factor (BDNF). A coexistence of nanoparticulate objects with different LC inner organizations is established. A transition from bicontinuous membrane sponges, cubosome intermediates and unilamelar liposomes to multilamellar vesicles, functionalized by pDNA, is favoured upon binding and compaction of pBDNF onto the cationic PEGylated lipid nanocarriers. The obtained sterically stabilized multicompartment nanoobjects, with confined supercoiled plasmid DNA (pBDNF), are important in the context of multicompartment lipid nanocarriers of interest for gene therapy of neurodegenerative diseases.

  18. A new look at lipid-membrane structure in relation to drug research

    DEFF Research Database (Denmark)

    Mouritsen, Ole G.; Jørgensen, Kent

    1998-01-01

    Lipid-bilayer membranes are key objects in drug research in relation to (i) interaction of drugs with membrane-bound receptors, (ii) drug targeting, penetration, and permeation of cell membranes, and (iii) use of liposomes in micro-encapsulation technologies for drug delivery. Rational design...... of new drugs and drug-delivery systems therefore requries insight into the physical properties of lipid-bilayer membranes. This mini-review provides a perspective on the current view of lipid-bilayer structure and dynamics based on information obtained from a variety of recent experimental...... and theoretical studies. Special attention is paid to trans-bilayer structure, lateral molecular organization of the lipid bilayer, lipid-mediated protein assembly, and lipid-bilayer permeability. It is argued that lipids play a major role in lipid membrane-organization and functionality....

  19. Probing Lipid Coating Dynamics of Quantum Dot Core Micelles via Forster Resonance Energy Transfer

    NARCIS (Netherlands)

    Zhao, Yiming; Schapotschnikow, Philipp; Skajaa, Torjus; Vlugt, Thijs J. H.; Mulder, Willem J. M.; de Mello Donegá, Celso; Meijerink, Andries

    2014-01-01

    Lipid coated nanocrystal assemblies are among the most extensively investigated nanoparticle platforms for biomedical imaging and therapeutic purposes. However, very few efforts have been addressed to the lipid coating exchange dynamics in such systems, which is key to our understanding of the

  20. 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...

  1. Newnes electronics assembly handbook

    CERN Document Server

    Brindley, Keith

    2013-01-01

    Newnes Electronics Assembly Handbook: Techniques, Standards and Quality Assurance focuses on the aspects of electronic assembling. The handbook first looks at the printed circuit board (PCB). Base materials, basic mechanical properties, cleaning of assemblies, design, and PCB manufacturing processes are then explained. The text also discusses surface mounted assemblies and packaging of electromechanical assemblies, as well as the soldering process. Requirements for the soldering process; solderability and protective coatings; cleaning of PCBs; and mass solder/component reflow soldering are des

  2. 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.

  3. 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.

  4. 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

  5. Guiding nanocrystal organization within mesoscale lipid thin-film templates

    Science.gov (United States)

    Steer, Dylan; Zhai, You; Oh, Nuri; Shim, Moonsub; Leal, Cecilia

    Recently a great deal of interest has been established in the cooperative intermolecular interactions in hard and soft meso-structured composite materials. Much of this research has focused on the effects of nanoparticle incorporation into block copolymers that otherwise self-assemble into periodic mesostructures through microphase separation. Through careful selection of the polymer components the nanoparticles can be directed to also microphase separate and therefore exhibit symmetry induced by the block copolymers. Such systems are promising for enabling the organization of nanoparticle superstructures. Although this is useful in many applications such as in bottom-up assembly of opti-electronic materials, most of these applications would benefit from interplay between structure and dynamics. Much like block-copolymers, lipids can self-assembly into a variety of structures with 1D lamellar, 2D Hexagonal, and 3D cubic symmetry. However, unlike block-copolymers phase stabilization and conversion from one geometry to another happens under a minute. We will show our recent efforts into using lipid thin films to guide the assembly of nanoparticle superstructures resembling those displayed by lipid polymorphs and how they distort lipid equilibrium phase behavior. Funding from the Office of Naval Research.

  6. Baxalpha5 at lipid membranes: structure, assembly and pore formation

    OpenAIRE

    Fuertes Vives, Gustavo

    2011-01-01

    Las proteínas de la familia Bcl-2 controlan la liberación de citocromo c, y otros factores apotogénicos, desde la mitocondria hacia el citosol. Los miembros proapoptóticos de la familia, como Bax, facilitan dicha liberación probablemente a través de la formación de poros proteolipídicos a nivel de la membrana mitocondrial externa. Por el contrario, los miembros antiapoptóticos, como Bcl-xL, bloquean la acción de Bax. Con el objetivo de mejorar nuestro conocimiento sobre la estructura y formac...

  7. Transient Self-assembly of Edible Lipids During Crystallization

    Science.gov (United States)

    Mazzanti, Gianfranco; Marangoni, Alejandro; Idziak, Stefan

    2002-03-01

    The effects of cooling rate and shear on the structure and crystallization behavior of two natural triglyceride melts were studied using rheology and light scattering. A transparent Couette Cell with 1 mm gap was used to perform light scattering measurements. A rheometer with concentric cylinders with 1 mm gap was used for the rheological tests. Experiments were carried out at cooling rates of 3 and 0.5 C/min from the 45 C melt down to temperatures between 17.5 C and 30 C. The shear rates imposed were 90 and 1440 s-1. Results show that the effect of shear on the onset of crystallization is especially evident at slow cooling rates. The effect of shear on crystalline phase growth is more pronounced at higher temperatures and slow cooling rates. Quasi-stationary studies were carried out in the rheometer operated in a controlled stress oscillatory mode, and strain amplitudes were less than 2experiments were performed in a petroleum analyzer and in a glass capillary. The onset of light scattering coincides with an unexpected transient increase in the amplitude of the oscillatory response.

  8. DNA/Fusogenic lipid nanocarrier assembly: millisecond structural dynamics

    Czech Academy of Sciences Publication Activity Database

    Angelov, Borislav; Angelova, A.; Filippov, Sergey K.; Narayanan, T.; Drechsler, M.; Štěpánek, Petr; Couvreur, P.; Lesieur, S.

    2013-01-01

    Roč. 4, č. 11 (2013), s. 1959-1964 ISSN 1948-7185 R&D Projects: GA ČR GAP208/10/1600 Institutional support: RVO:61389013 Keywords : lipoplex * SAXS * cryo-TEM Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 6.687, year: 2013

  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. Mesoscale organization of domains in the plasma membrane - beyond the lipid raft.

    Science.gov (United States)

    Lu, Stella M; Fairn, Gregory D

    2018-04-01

    The plasma membrane is compartmentalized into several distinct regions or domains, which show a broad diversity in both size and lifetime. The segregation of lipids and membrane proteins is thought to be driven by the lipid composition itself, lipid-protein interactions and diffusional barriers. With regards to the lipid composition, the immiscibility of certain classes of lipids underlies the "lipid raft" concept of plasmalemmal compartmentalization. Historically, lipid rafts have been described as cholesterol and (glyco)sphingolipid-rich regions of the plasma membrane that exist as a liquid-ordered phase that are resistant to extraction with non-ionic detergents. Over the years the interest in lipid rafts grew as did the challenges with studying these nanodomains. The term lipid raft has fallen out of favor with many scientists and instead the terms "membrane raft" or "membrane nanodomain" are preferred as they connote the heterogeneity and dynamic nature of the lipid-protein assemblies. In this article, we will discuss the classical lipid raft hypothesis and its limitations. This review will also discuss alternative models of lipid-protein interactions, annular lipid shells, and larger membrane clusters. We will also discuss the mesoscale organization of plasmalemmal domains including visible structures such as clathrin-coated pits and caveolae.

  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. Monitoring Growth and Lipid Production of Some Egyptian Microalgae

    International Nuclear Information System (INIS)

    El-Baghdady, K.Z.; Zakaria, A.E.; Mousa, L.A.; Sadek, H.N.; Abd El Fatah, H.M.

    2016-01-01

    Microalgae bio diesel is a green and renewable energy resource. This study aims to examine growth and lipid production by various isolates of icroalgae using different growth media and lipid extraction techniques. Ten microalgae isolates were isolated from different samples collected from Egypt. The purified isolates were identified microscopically as: Lyngbya confervoides, Phormidium bohneri, Oscillatoria pseudogeminata, Amorphonostoc sp., Nostoc paludosum, Anabaena sphaerica related to cyanobacteria (blue green algae) and Chlorella vulgaris, Chlorella ellipsoidea, Scened esmusacutus acutus, Chlamydomonas globose related to green algae. These organisms were cultivated on two media: Bold's Basal Medium(BBM medium) and Blue Green Medium (BG-11 medium) to examine the favorite medium which supports the growth of each isolate In order to examine lipid production potentials by cyanobacterial isolates and green microalgae, two solvent systems were applied for lipid extraction, the first was (Chloroform - methanol 1:1 ) and the second was (Hexane-ethanol 1:1). Chlorella vulgaris and Anabaena sphaerica were selected as models of green microalgae and cyanobacteria espectively. Hexane-ethanol solvent system revealed higher lipid extraction capacity as compared to Chloroform- methanol system. A comparison between ten organisms for lipid production was carried out by the selected solvent mixture. The percentages of lipid to dry weight produced by Oscillatoria pseudogeminata and Chlamydomonas globose were 19.8% and14 .6% respectively recording the highest lipid to dry weight percentage. They can be considered as a promising lipid producing microalgae

  13. Lipid nanotechnologies for structural studies of membrane-associated proteins.

    Science.gov (United States)

    Stoilova-McPhie, Svetla; Grushin, Kirill; Dalm, Daniela; Miller, Jaimy

    2014-11-01

    We present a methodology of lipid nanotubes (LNT) and nanodisks technologies optimized in our laboratory for structural studies of membrane-associated proteins at close to physiological conditions. The application of these lipid nanotechnologies for structure determination by cryo-electron microscopy (cryo-EM) is fundamental for understanding and modulating their function. The LNTs in our studies are single bilayer galactosylceramide based nanotubes of ∼20 nm inner diameter and a few microns in length, that self-assemble in aqueous solutions. The lipid nanodisks (NDs) are self-assembled discoid lipid bilayers of ∼10 nm diameter, which are stabilized in aqueous solutions by a belt of amphipathic helical scaffold proteins. By combining LNT and ND technologies, we can examine structurally how the membrane curvature and lipid composition modulates the function of the membrane-associated proteins. As proof of principle, we have engineered these lipid nanotechnologies to mimic the activated platelet's phosphtaidylserine rich membrane and have successfully assembled functional membrane-bound coagulation factor VIII in vitro for structure determination by cryo-EM. The macromolecular organization of the proteins bound to ND and LNT are further defined by fitting the known atomic structures within the calculated three-dimensional maps. The combination of LNT and ND technologies offers a means to control the design and assembly of a wide range of functional membrane-associated proteins and complexes for structural studies by cryo-EM. The presented results confirm the suitability of the developed methodology for studying the functional structure of membrane-associated proteins, such as the coagulation factors, at a close to physiological environment. © 2014 Wiley Periodicals, Inc.

  14. Analysis of reconfigurable assembly system framing systems in automotive industry

    Directory of Open Access Journals (Sweden)

    Md Zain Mohamad Zamri

    2017-01-01

    Full Text Available Current trend in automotive industry shows increasing demand for multiple models with lean production. Prior to that, automotive manufacturing systems evolved from mass production to flexible automation. Material handling systems and equipment in a single assembly line with multiple models require high investment but with low throughput thus making production cost relatively high. Current assembly process of side structure and undercarriage with downtime occurrence during assembly process affecting production performance (quality, cost and delivery. Manufacturing facilities should allow more flexibility and increase intelligence evolving toward novel reconfigurable assembly systems (RAS. RAS is envisaged capable of increasing factor flexibility and responsiveness by incorporating assembly jig, robot and framing, which could be next generation of world class automotive assembly systems. This project research proposes a new methodology of framework reconfigurable assembly systems principles in automotive framing systems i.e. enhance assembly process between side structure assembly and undercarriage assembly which a new RAS is capable to reconfigure the assembly processes of multiple model on a single assembly line. Simulation software (Witness will be used to simulate and validate current and proposed assembly process. RAS is expected to be a solution for rapid change in structure and for a responsively adjustable production capacity. Quality, cost and delivery are production key parameters that can be achieved by implementing RAS.

  15. Light-activated control of protein channel assembly mediated by membrane mechanics

    Science.gov (United States)

    Miller, David M.; Findlay, Heather E.; Ces, Oscar; Templer, Richard H.; Booth, Paula J.

    2016-12-01

    Photochemical processes provide versatile triggers of chemical reactions. Here, we use a photoactivated lipid switch to modulate the folding and assembly of a protein channel within a model biological membrane. In contrast to the information rich field of water-soluble protein folding, there is only a limited understanding of the assembly of proteins that are integral to biological membranes. It is however possible to exploit the foreboding hydrophobic lipid environment and control membrane protein folding via lipid bilayer mechanics. Mechanical properties such as lipid chain lateral pressure influence the insertion and folding of proteins in membranes, with different stages of folding having contrasting sensitivities to the bilayer properties. Studies to date have relied on altering bilayer properties through lipid compositional changes made at equilibrium, and thus can only be made before or after folding. We show that light-activation of photoisomerisable di-(5-[[4-(4-butylphenyl)azo]phenoxy]pentyl)phosphate (4-Azo-5P) lipids influences the folding and assembly of the pentameric bacterial mechanosensitive channel MscL. The use of a photochemical reaction enables the bilayer properties to be altered during folding, which is unprecedented. This mechanical manipulation during folding, allows for optimisation of different stages of the component insertion, folding and assembly steps within the same lipid system. The photochemical approach offers the potential to control channel assembly when generating synthetic devices that exploit the mechanosensitive protein as a nanovalve.

  16. Wrinkled1 accelerates flowering and regulates lipid homeostasis between oil accumulation and membrane lipid anabolism in Brassica napus

    Directory of Open Access Journals (Sweden)

    Qing eLi

    2015-11-01

    Full Text Available Wrinkled1 (WRI1 belongs to the APETALA2 transcription factor family; it is unique to plants and is a central regulator of oil synthesis in Arabidopsis. The effects of WRI1 on comprehensive lipid metabolism and plant development were unknown, especially in crop plants. This study found that BnWRI1 in Brassica napus accelerated flowering and enhanced oil accumulation in both seeds and leaves without leading to a visible growth inhibition. BnWRI1 decreased storage carbohydrates and increased soluble sugars to facilitate the carbon flux to lipid anabolism. BnWRI1 is localized to the nucleus and directly binds to the AW-box at proximal upstream regions of genes involved in fatty acid synthesis and lipid assembly. The overexpression (OE of BnWRI1 resulted in the up-regulation of genes involved in glycolysis, fatty acid synthesis, lipid assembly, and flowering. Lipid profiling revealed increased galactolipid monogalactosyldiacylglycerol (MGDG, digalactosyldiacylglycerol (DGDG, and phosphatidylcholine (PC in the leaves of OE plants, whereas it exhibited a reduced level of the galactolipids DGDG and MGDG and increased levels of PC, phosphatidylethanolamide (PE, and oil (triacylglycerol, TAG in the siliques of OE plants during the early seed development stage. These results suggest that BnWRI1 is important for homeostasis among TAG, membrane lipids and sugars, and thus facilitates flowering and oil accumulation in B. napus.

  17. 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...

  18. PEGylation of Phytantriol-Based Lyotropic Liquid Crystalline Particles-The Effect of Lipid Composition, PEG Chain Length, and Temperature on the Internal Nanostructure

    DEFF Research Database (Denmark)

    Nilsson, Christa; Ostergaard, Jesper; Larsen, Susan Weng

    2014-01-01

    of these lipidic nonlamellar liquid crystalline particles by using DSPE-mPEGs with three different block lengths of the hydrophilic PEG segment. The effects of lipid composition, PEG chain length, and temperature on the morphology and internal nanostructure of these self-assembled lipidic aqueous dispersions based...

  19. Fuel assembly guide tube

    International Nuclear Information System (INIS)

    Jabsen, F.S.

    1979-01-01

    This invention is directed toward a nuclear fuel assembly guide tube arrangement which restrains spacer grid movement due to coolant flow and which offers secondary means for supporting a fuel assembly during handling and transfer operations

  20. Biomimetic Cationic Nanoparticles Based on Silica: Optimizing Bilayer Deposition from Lipid Films

    Directory of Open Access Journals (Sweden)

    Rodrigo T. Ribeiro

    2017-10-01

    Full Text Available The optimization of bilayer coverage on particles is important for a variety of biomedical applications, such as drug, vaccine, and genetic material delivery. This work aims at optimizing the deposition of cationic bilayers on silica over a range of experimental conditions for the intervening medium and two different assemblies for the cationic lipid, namely, lipid films or pre-formed lipid bilayer fragments. The lipid adsorption on silica in situ over a range of added lipid concentrations was determined from elemental analysis of carbon, hydrogen, and nitrogen and related to the colloidal stability, sizing, zeta potential, and polydispersity of the silica/lipid nanoparticles. Superior bilayer deposition took place from lipid films, whereas adsorption from pre-formed bilayer fragments yielded limiting adsorption below the levels expected for bilayer adsorption.

  1. Structural Aspects of Bacterial Outer Membrane Protein Assembly.

    Science.gov (United States)

    Calmettes, Charles; Judd, Andrew; Moraes, Trevor F

    2015-01-01

    The outer membrane of Gram-negative bacteria is predominantly populated by β-Barrel proteins and lipid anchored proteins that serve a variety of biological functions. The proper folding and assembly of these proteins is essential for bacterial viability and often plays a critical role in virulence and pathogenesis. The β-barrel assembly machinery (Bam) complex is responsible for the proper assembly of β-barrels into the outer membrane of Gram-negative bacteria, whereas the localization of lipoproteins (Lol) system is required for proper targeting of lipoproteins to the outer membrane.

  2. Pairing of cholesterol with oxidized phospholipid species in lipid bilayers

    DEFF Research Database (Denmark)

    Khandelia, Himanshu; Loubet, Bastien; Olzynska, Agnieszka

    2014-01-01

    We claim that (1) cholesterol protects bilayers from disruption caused by lipid oxidation by sequestering conical shaped oxidized lipid species such as 1-palmitoyl-2-azelaoyl-sn-glycero-3-phosphocholine (PZPC) away from phospholipid, because cholesterol and the oxidized lipid have complementary...... shapes and (2) mixtures of cholesterol and oxidized lipids can self-assemble into bilayers much like lysolipid–cholesterol mixtures. The evidence for bilayer protection comes from molecular dynamics (MD) simulations and dynamic light scattering (DLS) measurements. Unimodal size distributions of extruded...... vesicles (LUVETs) made up of a mixture of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and PZPC containing high amounts of PZPC are only obtained when cholesterol is present in high concentrations. In simulations, bilayers containing high amounts of PZPC become porous, unless cholesterol is also present...

  3. Polymer Directed Protein Assemblies

    NARCIS (Netherlands)

    van Rijn, Patrick

    2013-01-01

    Protein aggregation and protein self-assembly is an important occurrence in natural systems, and is in some form or other dictated by biopolymers. Very obvious influences of biopolymers on protein assemblies are, e. g., virus particles. Viruses are a multi-protein assembly of which the morphology is

  4. Nuclear reactor fuel assembly

    International Nuclear Information System (INIS)

    Sasaki, Y.; Tashima, J.

    1975-01-01

    A description is given of nuclear reactor fuel assemblies arranged in the form of a lattice wherein there is attached to the interface of one of two adjacent fuel assemblies a plate spring having a concave portion curved toward said interface and to the interface of the other fuel assembly a plate spring having a convex portion curved away from said interface

  5. 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

  6. Secretion of hepatitis C virus envelope glycoproteins depends on assembly of apolipoprotein B positive lipoproteins.

    Directory of Open Access Journals (Sweden)

    Vinca Icard

    Full Text Available The density of circulating hepatitis C virus (HCV particles in the blood of chronically infected patients is very heterogeneous. The very low density of some particles has been attributed to an association of the virus with apolipoprotein B (apoB positive and triglyceride rich lipoproteins (TRL likely resulting in hybrid lipoproteins known as lipo-viro-particles (LVP containing the viral envelope glycoproteins E1 and E2, capsid and viral RNA. The specific infectivity of these particles has been shown to be higher than the infectivity of particles of higher density. The nature of the association of HCV particles with lipoproteins remains elusive and the role of apolipoproteins in the synthesis and assembly of the viral particles is unknown. The human intestinal Caco-2 cell line differentiates in vitro into polarized and apoB secreting cells during asymmetric culture on porous filters. By using this cell culture system, cells stably expressing E1 and E2 secreted the glycoproteins into the basal culture medium after one week of differentiation concomitantly with TRL secretion. Secreted glycoproteins were only detected in apoB containing density fractions. The E1-E2 and apoB containing particles were unique complexes bearing the envelope glycoproteins at their surface since apoB could be co-immunoprecipitated with E2-specific antibodies. Envelope protein secretion was reduced by inhibiting the lipidation of apoB with an inhibitor of the microsomal triglyceride transfer protein. HCV glycoproteins were similarly secreted in association with TRL from the human liver cell line HepG2 but not by Huh-7 and Huh-7.5 hepatoma cells that proved deficient for lipoprotein assembly. These data indicate that HCV envelope glycoproteins have the intrinsic capacity to utilize apoB synthesis and lipoprotein assembly machinery even in the absence of the other HCV proteins. A model for LVP assembly is proposed.

  7. Sensor mount assemblies and sensor assemblies

    Science.gov (United States)

    Miller, David H [Redondo Beach, CA

    2012-04-10

    Sensor mount assemblies and sensor assemblies are provided. In an embodiment, by way of example only, a sensor mount assembly includes a busbar, a main body, a backing surface, and a first finger. The busbar has a first end and a second end. The main body is overmolded onto the busbar. The backing surface extends radially outwardly relative to the main body. The first finger extends axially from the backing surface, and the first finger has a first end, a second end, and a tooth. The first end of the first finger is disposed on the backing surface, and the tooth is formed on the second end of the first finger.

  8. Soldering in electronics assembly

    CERN Document Server

    Judd, Mike

    2013-01-01

    Soldering in Electronics Assembly discusses several concerns in soldering of electronic assemblies. The book is comprised of nine chapters that tackle different areas in electronic assembly soldering. Chapter 1 discusses the soldering process itself, while Chapter 2 covers the electronic assemblies. Chapter 3 talks about solders and Chapter 4 deals with flux. The text also tackles the CS and SC soldering process. The cleaning of soldered assemblies, solder quality, and standards and specifications are also discussed. The book will be of great use to professionals who deal with electronic assem

  9. Nuclear fuel string assembly

    International Nuclear Information System (INIS)

    Ip, A.K.; Koyanagi, K.; Tarasuk, W.R.

    1976-01-01

    A method of fabricating rodded fuels suitable for use in pressure tube type reactors and in pressure vessel type reactors is described. Fuel rods are secured as an inner and an outer sub-assembly, each rod attached between mounting rings secured to the rod ends. The two sub-assemblies are telescoped together and positioned by spaced thimbles located between them to provide precise positioning while permittng differential axial movement between the sub-assemblies. Such sub-assemblies are particularly suited for mounting as bundle strings. The method provides particular advantages in the assembly of annular-section fuel pins, which includes booster fuel containing enriched fuel material. (LL)

  10. Nuclear reactor fuel assembly

    International Nuclear Information System (INIS)

    Marmonier, Pierre; Mesnage, Bernard; Nervi, J.C.

    1975-01-01

    This invention refers to fuel assemblies for a liquid metal cooled fast neutron reactor. Each assembly is composed of a hollow vertical casing, of regular polygonal section, containing a bundle of clad pins filled with a fissile or fertile substance. The casing is open at its upper end and has a cylindrical foot at its lower end for positioning the assembly in a housing provided in the horizontal diagrid, on which the core assembly rests. A set of flat bars located on the external surface of the casing enables it to be correctly orientated in its housing among the other core assemblies [fr

  11. Thermomechanical behaviour of bolted assemblies

    International Nuclear Information System (INIS)

    Scliffet, L.

    1995-01-01

    This paper presents first results obtained in an R and D study on the thermomechanical behaviour of bolted assemblies. Thermal shocks during operating transients both severely distort such assemblies and cause variations in stud pre-loads. So during a hot shock, the thermal gradient in the flange induced over-tightening due to the differential thermal expansion involved. Over-tightening can reach 70% of the nominal value, usually after 10 to 15 mn, after which the stress relaxes as soon as the heating affects the stud. A series of hot shocks causes assembly fatigue, notably resulting in thread plasticization, making it impossible to tighten the studs. In the case of cold transients, the reverse phenomenon is observed. The hot flange contracts sharply upon contact with the cold fluid, causing stress relief in the expanded studs. The resulting loss of tensile stress, which reaches up to 50%, can then cause severe leakage, especially if the nominal tightening capacity is already impaired. The study presented is based on tests and modelling. (author). 16 figs

  12. Inducing morphological changes in lipid bilayer membranes with microfabricated substrates

    Science.gov (United States)

    Liu, Fangjie; Collins, Liam F.; Ashkar, Rana; Heberle, Frederick A.; Srijanto, Bernadeta R.; Collier, C. Patrick

    2016-11-01

    Lateral organization of lipids and proteins into distinct domains and anchoring to a cytoskeleton are two important strategies employed by biological membranes to carry out many cellular functions. However, these interactions are difficult to emulate with model systems. Here we use the physical architecture of substrates consisting of arrays of micropillars to systematically control the behavior of supported lipid bilayers - an important step in engineering model lipid membrane systems with well-defined functionalities. Competition between attractive interactions of supported lipid bilayers with the underlying substrate versus the energy cost associated with membrane bending at pillar edges can be systematically investigated as functions of pillar height and pitch, chemical functionalization of the microstructured substrate, and the type of unilamellar vesicles used for assembling the supported bilayer. Confocal fluorescent imaging and AFM measurements highlight correlations that exist between topological and mechanical properties of lipid bilayers and lateral lipid mobility in these confined environments. This study provides a baseline for future investigations into lipid domain reorganization on structured solid surfaces and scaffolds for cell growth.

  13. 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.

  14. Orientation of biomolecular assemblies in a microfluidic jet

    International Nuclear Information System (INIS)

    Priebe, M; Kalbfleisch, S; Tolkiehn, M; Salditt, T; Koester, S; Abel, B; Davies, R J

    2010-01-01

    We have investigated multilamellar lipid assemblies in a microfluidic jet, operating at high shear rates of the order of 10 7 s -1 . Compared to classical Couette cells or rheometers, the shear rate was increased by at least 2-3 orders of magnitude, and the sample volume was scaled down correspondingly. At the same time, the jet is characterized by high extensional stress due to elongational flow. A focused synchrotron x-ray beam was used to measure the structure and orientation of the lipid assemblies in the jet. The diffraction patterns indicate conventional multilamellar phases, aligned with the membrane normals oriented along the velocity gradient of the jet. The results indicate that the setup may be well suited for coherent diffractive imaging of oriented biomolecular assemblies and macromolecules at the future x-ray free electron laser (XFEL) sources.

  15. Influence of Polyethylene Glycol Lipid Desorption Rates on Pharmacokinetics and Pharmacodynamics of siRNA Lipid Nanoparticles

    Directory of Open Access Journals (Sweden)

    Barbara L Mui

    2013-01-01

    Full Text Available Lipid nanoparticles (LNPs encapsulating short interfering RNAs that target hepatic genes are advancing through clinical trials, and early results indicate the excellent gene silencing observed in rodents and nonhuman primates also translates to humans. This success has motivated research to identify ways to further advance this delivery platform. Here, we characterize the polyethylene glycol lipid (PEG-lipid components, which are required to control the self-assembly process during formation of lipid particles, but can negatively affect delivery to hepatocytes and hepatic gene silencing in vivo. The rate of transfer from LNPs to plasma lipoproteins in vivo is measured for three PEG-lipids with dialkyl chains 14, 16, and 18 carbons long. We show that 1.5 mol % PEG-lipid represents a threshold concentration at which the chain length exerts a minimal effect on hepatic gene silencing but can still modify LNPs pharmacokinetics and biodistribution. Increasing the concentration to 2.5 and 3.5 mol % substantially compromises hepatocyte gene knockdown for PEG-lipids with distearyl (C18 chains but has little impact for shorter dimyristyl (C14 chains. These data are discussed with respect to RNA delivery and the different rates at which the steric barrier disassociates from LNPs in vivo.

  16. 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.

  17. Modeling of Parameters of Subcritical Assembly SAD

    CERN Document Server

    Petrochenkov, S; Puzynin, I

    2005-01-01

    The accepted conceptual design of the experimental Subcritical Assembly in Dubna (SAD) is based on the MOX core with a nominal unit capacity of 25 kW (thermal). This corresponds to the multiplication coefficient $k_{\\rm eff} =0.95$ and accelerator beam power 1 kW. A subcritical assembly driven with the existing 660 MeV proton accelerator at the Joint Institute for Nuclear Research has been modelled in order to make choice of the optimal parameters for the future experiments. The Monte Carlo method was used to simulate neutron spectra, energy deposition and doses calculations. Some of the calculation results are presented in the paper.

  18. In vitro synthesis of a lipid-linked trisaccharide involved in synthesis of enterobacterial common antigen

    International Nuclear Information System (INIS)

    Barr, K.; Nunes-Edwards, P.; Rick, P.D.

    1989-01-01

    The heteropolysaccharide chains of enterobacterial common antigen (ECA) are made up of linear trisaccharide repeat units with the structure----3)-alpha-D-Fuc4NAc-(1----4)- beta-D-ManNAcA-(1----4)-alpha-D-GlcNAc-(1----, where Fuc4NAc is 4-acetamido-4,6-dideoxy-D-galactose, ManNAcA is N-acetyl-D-mannosaminuronic acid, and GlcNAc is N-acetyl-D-glucosamine. The assembly of these chains involves lipid-linked intermediates, and both GlcNAc-pyrophosphorylundecaprenol (lipid I) and ManNAcA-GlcNAc-pyrophosphorylundecaprenol (lipid II) are intermediates in ECA biosynthesis. In this study we demonstrated that lipid II serves as the acceptor of Fuc4NAc residues in the assembly of the trisaccharide repeat unit of ECA chains. Incubation of Escherichia coli membranes with UDP-GlcNAc, UDP-[14C]ManNAcA, and TDP-[3H]Fuc4NAc resulted in the synthesis of a radioactive glycolipid (lipid III) that contained both [14C]ManNAcA and [3H]Fuc4NAc. The oligosaccharide moiety of lipid III was identified as a trisaccharide by gel-permeation chromatography, and the in vitro synthesis of lipid III was dependent on prior synthesis of lipids I and II. Accordingly, the incorporation of [3H]Fuc4NAc into lipid III from the donor TDP-[3H]Fuc4NAc was dependent on the presence of both UDP-GlcNAc and UDP-ManNAcA in the reaction mixtures. In addition, the in vitro synthesis of lipid III was abolished by tunicamycin. Direct conversion of lipid II to lipid III was demonstrated in two-stage reactions in which membranes were initially incubated with UDP-GlcNAc and UDP-[14C]ManNAcA to allow the synthesis of radioactive lipid II

  19. 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.

  20. 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.

  1. 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

  2. Aluminum induces lipid peroxidation and aggregation of human blood platelets

    Directory of Open Access Journals (Sweden)

    T.J.C. Neiva

    1997-05-01

    Full Text Available Aluminum (Al3+ intoxication is thought to play a major role in the development of Alzheimer's disease and in certain pathologic manifestations arising from long-term hemodialysis. Although the metal does not present redox capacity, it can stimulate tissue lipid peroxidation in animal models. Furthermore, in vitro studies have revealed that the fluoroaluminate complex induces diacylglycerol formation, 43-kDa protein phosphorylation and aggregation. Based on these observations, we postulated that Al3+-induced blood platelet aggregation was mediated by lipid peroxidation. Using chemiluminescence (CL of luminol as an index of total lipid peroxidation capacity, we established a correlation between lipid peroxidation capacity and platelet aggregation. Al3+ (20-100 µM stimulated CL production by human blood platelets as well as their aggregation. Incubation of the platelets with the antioxidants nor-dihydroguaiaretic acid (NDGA (100 µM and n-propyl gallate (NPG (100 µM, inhibitors of the lipoxygenase pathway, completely prevented CL and platelet aggregation. Acetyl salicylic acid (ASA (100 µM, an inhibitor of the cyclooxygenase pathway, was a weaker inhibitor of both events. These findings suggest that Al3+ stimulates lipid peroxidation and the lipoxygenase pathway in human blood platelets thereby causing their aggregation

  3. Assembly tool design

    International Nuclear Information System (INIS)

    Kanamori, Naokazu; Nakahira, Masataka; Ohkawa, Yoshinao; Tada, Eisuke; Seki, Masahiro

    1996-06-01

    The reactor core of the International Thermonuclear Experimental Reactor (ITER) is assembled with a number of large and asymmetric components within a tight tolerance in order to assure the structural integrity for various loads and to provide the tritium confinement. In addition, the assembly procedure should be compatible with remote operation since the core structures will be activated by 14-MeV neutrons once it starts operation and thus personal access will be prohibited. Accordingly, the assembly procedure and tool design are quite essential and should be designed from the beginning to facilitate remote operation. According to the ITER Design Task Agreement, the Japan Atomic Energy Research Institute (JAERI) has performed design study to develop the assembly procedures and associated tool design for the ITER tokamak assembly. This report describes outlines of the assembly tools and the remaining issues obtained in this design study. (author)

  4. Interaction pathways between soft lipid nanodiscs and plasma membranes: A molecular modeling study.

    Science.gov (United States)

    Li, Shixin; Luo, Zhen; Xu, Yan; Ren, Hao; Deng, Li; Zhang, Xianren; Huang, Fang; Yue, Tongtao

    2017-10-01

    Lipid nanodisc, a model membrane platform originally synthesized for study of membrane proteins, has recently been used as the carrier to deliver amphiphilic drugs into target tumor cells. However, the central question of how cells interact with such emerging nanomaterials remains unclear and deserves our research for both improving the delivery efficiency and reducing the side effect. In this work, a binary lipid nanodisc is designed as the minimum model to investigate its interactions with plasma membranes by using the dissipative particle dynamics method. Three typical interaction pathways, including the membrane attachment with lipid domain exchange of nanodiscs, the partial membrane wrapping with nanodisc vesiculation, and the receptor-mediated endocytosis, are discovered. For the first pathway, the boundary normal lipids acting as ligands diffuse along the nanodisc rim to gather at the membrane interface, repelling the central bola lipids to reach a stable membrane attachment. If bola lipids are positioned at the periphery and act as ligands, they diffuse to form a large aggregate being wrapped by the membrane, leaving the normal lipids exposed on the membrane exterior by assembling into a vesicle. Finally, by setting both central normal lipids and boundary bola lipids as ligands, the receptor-mediated endocytosis occurs via both deformation and self-rotation of the nanodiscs. All above pathways for soft lipid nanodiscs are quite different from those for rigid nanoparticles, which may provide useful guidelines for design of soft lipid nanodiscs in widespread biomedical applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Lipid metabolism in myelinating glial cells: lessons from human inherited disorders and mouse models.

    Science.gov (United States)

    Chrast, Roman; Saher, Gesine; Nave, Klaus-Armin; Verheijen, Mark H G

    2011-03-01

    The integrity of central and peripheral nervous system myelin is affected in numerous lipid metabolism disorders. This vulnerability was so far mostly attributed to the extraordinarily high level of lipid synthesis that is required for the formation of myelin, and to the relative autonomy in lipid synthesis of myelinating glial cells because of blood barriers shielding the nervous system from circulating lipids. Recent insights from analysis of inherited lipid disorders, especially those with prevailing lipid depletion and from mouse models with glia-specific disruption of lipid metabolism, shed new light on this issue. The particular lipid composition of myelin, the transport of lipid-associated myelin proteins, and the necessity for timely assembly of the myelin sheath all contribute to the observed vulnerability of myelin to perturbed lipid metabolism. Furthermore, the uptake of external lipids may also play a role in the formation of myelin membranes. In addition to an improved understanding of basic myelin biology, these data provide a foundation for future therapeutic interventions aiming at preserving glial cell integrity in metabolic disorders.

  6. Engineering lipid structure for recognition of the liquid ordered membrane phase

    International Nuclear Information System (INIS)

    Bordovsky, Stefan S.; Wong, Christopher S.; Bachand, George D.; Stachowiak, Jeanne C.; Sasaki, Darryl Y.

    2016-01-01

    The selective partitioning of lipid components in phase-separated membranes is essential for domain formation involved in cellular processes. Identifying and tracking the movement of lipids in cellular systems would be improved if we understood how to achieve selective affinity between fluorophore-labeled lipids and membrane assemblies. Furthermore, we investigated the structure and chemistry of membrane lipids to evaluate lipid designs that partition to the liquid ordered (L_o) phase. A range of fluorophores at the headgroup position and lengths of PEG spacer between the lipid backbone and fluorophore were examined. On a lipid body with saturated palmityl or palmitoyl tails, we found that although the lipid tails can direct selective partitioning to the L_o phase through favorable packing interactions, headgroup hydrophobicity can override the partitioning behavior and direct the lipid to the disordered membrane phase (L_d). The PEG spacer can serve as a buffer to mute headgroup–membrane interactions and thus improve L_o phase partitioning, but its effect is limited with strongly hydrophobic fluorophore headgroups. We present a series of lipid designs leading to the development of novel fluorescently labeled lipids with selective affinity for the L_o phase.

  7. Probing lipid coating dynamics of quantum dot core micelles via förster resonance energy transfer

    NARCIS (Netherlands)

    Zhao, Yiming; Schapotschnikow, Philipp; Skajaa, Torjus; Vlugt, Thijs J H; Mulder, Willem J M; De Mello Donegá, Celso; Meijerink, A

    2014-01-01

    Lipid coated nanocrystal assemblies are among the most extensively investigated nanoparticle platforms for biomedical imaging and therapeutic purposes. However, very few efforts have been addressed to the lipid coating exchange dynamics in such systems, which is key to our understanding of the

  8. Lipid chain geometry of C14 glycerol-based lipids: effect on lipoplex structure and transfection.

    Science.gov (United States)

    Kudsiova, Laila; Ho, Jimmy; Fridrich, Barbara; Harvey, Richard; Keppler, Melanie; Ng, Tony; Hart, Stephen L; Tabor, Alethea B; Hailes, Helen C; Lawrence, M Jayne

    2011-02-01

    The effects have been determined of a systematic alteration of the alkyl chain geometry of a C14 analogue of DOTMA on the detailed molecular architecture of the resulting cationic vesicles formed both in the absence and presence of 50 mol% DOPE, and of the lipoplexes prepared from these vesicles using either calf thymus or plasmid DNA. The C14 DOTMA analogues studied involved cis- or trans-double bonds at positions Δ9 or Δ11, and a compound (ALK) featuring an alkyne at position C9. For all of these analogues, examination by light scattering and neutron scattering, zeta potential measurement, and negative staining electron microscopy showed that there were no significant differences in the structures or charges of the vesicles or of the resulting lipoplexes, regardless of the nature of the DNA incorporated. Differences were observed, however, between the complexes formed by the various lipids when examining the extent of complexation and release by gel electrophoresis, where the E-lipids appeared to complex the DNA more efficiently than all other lipids tested. Moreover, the lipoplexes prepared from the E-lipids were the most effective in transfection of MDA-MB-231 breast cancer cells. As indicated through confocal microscopy studies, the E-lipids also showed a higher internalisation capacity and a more diffuse cellular distribution, possibly indicating a greater degree of endosomal escape and/or nuclear import. These observations suggest that the extent of complexation is the most important factor in determining the transfection efficiency of the complexes tested. At present it is unclear why the E-lipids were more effective at complexing DNA, although it is thought that the effective area per molecule occupied by the cationic lipid and DOPE head groups, and therefore the density of positive charges on the surface of the bilayer most closely matches the negative charge density of the DNA molecule. From a consideration of the geometry of the cationic lipids it is

  9. 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.

  10. Fuel assembly storage pool

    International Nuclear Information System (INIS)

    Hiranuma, Hiroshi.

    1976-01-01

    Object: To remove limitation of the number of storage of fuel assemblies to increase the number of storage thereof so as to relatively reduce the water depth required for shielding radioactive rays. Structure: Fuel assembly storage rack containers for receiving a plurality of spent fuel assembly racks are stacked in multi-layer fashion within a storage pool filled with water for shielding radioactive rays and removing heat. (Furukawa, Y.)

  11. Blocked muscle fat oxidation during exercise in neutral lipid storage disease

    DEFF Research Database (Denmark)

    Laforêt, Pascal; Ørngreen, Mette; Preisler, Nicolai

    2012-01-01

    To determine whether impaired exercise capacity in neutral lipid storage disease with myopathy is solely caused by muscle weakness or whether a defect in energy metabolism (blocked fat oxidation) may also play a role.......To determine whether impaired exercise capacity in neutral lipid storage disease with myopathy is solely caused by muscle weakness or whether a defect in energy metabolism (blocked fat oxidation) may also play a role....

  12. Target Assembly Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Target Assembly Facility integrates new armor concepts into actual armored vehicles. Featuring the capability ofmachining and cutting radioactive materials, it...

  13. Composite turbine bucket assembly

    Science.gov (United States)

    Liotta, Gary Charles; Garcia-Crespo, Andres

    2014-05-20

    A composite turbine blade assembly includes a ceramic blade including an airfoil portion, a shank portion and an attachment portion; and a transition assembly adapted to attach the ceramic blade to a turbine disk or rotor, the transition assembly including first and second transition components clamped together, trapping said ceramic airfoil therebetween. Interior surfaces of the first and second transition portions are formed to mate with the shank portion and the attachment portion of the ceramic blade, and exterior surfaces of said first and second transition components are formed to include an attachment feature enabling the transition assembly to be attached to the turbine rotor or disk.

  14. Golden rain tree leaf extracts as potential inhibitor of lipid ...

    African Journals Online (AJOL)

    This study was designed to evaluate the peroxyl radical scavenging capacity and deoxyribonucleic acid (DNA) protective effect of extract/fractions of Koelreuteria paniculata Laxm. (Golden rain tree) in lipid peroxidation assay and calf thymus DNA protection assay. The leaves of the plant were extracted with different ...

  15. Lipid-peptide-polymer conjugates and nanoparticles thereof

    Science.gov (United States)

    Xu, Ting; Dong, He; Shu, Jessica

    2015-06-02

    The present invention provides a conjugate having a peptide with from about 10 to about 100 amino acids, wherein the peptide adopts a helical structure. The conjugate also includes a first polymer covalently linked to the peptide, and a hydrophobic moiety covalently linked to the N-terminus of the peptide, wherein the hydrophobic moiety comprises a second polymer or a lipid moiety. The present invention also provides helix bundles form by self-assembling the conjugates, and particles formed by self-assembling the helix bundles. Methods of preparing the helix bundles and particles are also provided.

  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. 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 ...

  2. 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 ...

  3. Lipid status in phyisiological non-complicated pregnancy

    Directory of Open Access Journals (Sweden)

    Ardalić Daniela

    2016-01-01

    Full Text Available Specifically altered lipid profile and physiological hyperlipidemia during pregnancy are considered essential for the normal course of pregnancy and fetal development. This specific alteration of the lipid profile raises the questions about potential proaterogenic effect of these altered lipid parameters during pregnancy and its influence on the development of cardiovascular disease in women later in life. Research topic was also the association of altered lipid profile during pregnancy with the development of complications in pregnancy, especially gestational diabetes, hypertension and preeclampsia. Through the mediation of cholesterol ester transfer protein (CETP, the activity of which grows in mid-gestation, there are exchanges of the triglycerides between VLDL and LDL or HDL particle, which leads to increased accumulation of triglycerides in these particles, causes them to become smaller and denser with much greater atherogenic potential. These changes in lipid profile point out that a large number of pregnancies increase risk of development of cardiovascular diseases later in life. In order to optimize the predictive capacity of the lipid profile during pregnancy, it is recommended to determine the indexes of lipid.

  4. Controlling Styrene Maleic Acid Lipid Particles through RAFT.

    Science.gov (United States)

    Smith, Anton A A; Autzen, Henriette E; Laursen, Tomas; Wu, Vincent; Yen, Max; Hall, Aaron; Hansen, Scott D; Cheng, Yifan; Xu, Ting

    2017-11-13

    The ability of styrene maleic acid copolymers to dissolve lipid membranes into nanosized lipid particles is a facile method of obtaining membrane proteins in solubilized lipid discs while conserving part of their native lipid environment. While the currently used copolymers can readily extract membrane proteins in native nanodiscs, their highly disperse composition is likely to influence the dispersity of the discs as well as the extraction efficiency. In this study, reversible addition-fragmentation chain transfer was used to control the polymer architecture and dispersity of molecular weights with a high-precision. Based on Monte Carlo simulations of the polymerizations, the monomer composition was predicted and allowed a structure-function analysis of the polymer architecture, in relation to their ability to assemble into lipid nanoparticles. We show that a higher degree of control of the polymer architecture generates more homogeneous samples. We hypothesize that low dispersity copolymers, with control of polymer architecture are an ideal framework for the rational design of polymers for customized isolation and characterization of integral membrane proteins in native lipid bilayer systems.

  5. Total iron binding capacity

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003489.htm Total iron binding capacity To use the sharing features on this page, please enable JavaScript. Total iron binding capacity (TIBC) is a blood test to ...

  6. Nuclear fuel assembly

    International Nuclear Information System (INIS)

    Delafosse, Jacques.

    1977-01-01

    This invention relates to a nuclear fuel assembly for a light or heavy water reactor, or for a fast reactor of the kind with a bundle of cladded pins, maintained parallel to each other in a regular network by an assembly of separate supporting grids, fitted with elastic bearing surfaces on these pins [fr

  7. Assembling Transgender Moments

    Science.gov (United States)

    Greteman, Adam J.

    2017-01-01

    In this article, the author seeks to assemble moments--scholarly, popular, and aesthetic--in order to explore the possibilities that emerge as moments collect in education's encounters with the needs, struggles, and possibilities of transgender lives and practices. Assembling moments, the author argues, illustrates the value of "moments"…

  8. Vertical pump assembly

    International Nuclear Information System (INIS)

    Dohnal, M.; Rosel, J.; Skarka, V.

    1988-01-01

    The mounting is described of the drive assembly of a vertical pump for nuclear power plants in areas with seismic risk. The assembly is attached to the building floor using flexible and damping elements. The design allows producing seismically resistant pumps without major design changes in the existing types of vertical pumps. (E.S.). 1 fig

  9. A hall for assembly and cryogenic tests

    International Nuclear Information System (INIS)

    Beaunier, J.; Buhler, S.; Caruette, A.; Chevrollier, R.; Junquera, T.; Le Scornet, J.C.

    1999-01-01

    Cryodrome, an assembly hall and the testing ground for cryogenic equipment and R and D experiments for the superconducting cavities is going to be transformed for its future missions. The cryogenic utilities, especially the He low pressure pumping capacity, was rearranged and extended to a new area. Space was provided to install CRYHOLAB, a new horizontal cryostat for cavity testing. Automatic control and supervision of the utilities and the experimental area are rebuilt and updated. (authors)

  10. Air capacity for Sydney

    OpenAIRE

    Forsyth, Peter

    2013-01-01

    Like most large cities, Sydney has an airport problem. Demand is increasing faster than supply, and additional capacity will be needed if costly rationing, and delays, are to be avoided. However, compared to many cities, the problems facing Sydney are modest. At the moment, demand is only just exceeding capacity. There is a good chance that the available capacity will be rationed efficiently. Options for expanding capacity are being evaluated well. There may be problems in the future- poor op...

  11. Responsibility and Capacities

    DEFF Research Database (Denmark)

    Ryberg, Jesper

    2014-01-01

    That responsible moral agency presupposes certain mental capacities, constitutes a widely accepted view among theorists. Moreover, it is often assumed that degrees in the development of the relevant capacities co-vary with degrees of responsibility. In this article it is argued that, the move from...... the view that responsibility requires certain mental capacities to the position that degrees of responsibility co-vary with degrees of the development of the mental capacities, is premature....

  12. Fuel Assembly Damping Summary

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kanghee; Kang, Heungseok; Oh, Dongseok; Yoon, Kyungho; Kim, Hyungkyu; Kim, Jaeyong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    This paper summary the fuel assembly damping data in air/in still water/under flow, released from foreign fuel vendors, compared our data with the published data. Some technical issues in fuel assembly damping measurement testing are also briefly discussed. Understanding of each fuel assembly damping mechanisms according to the surrounding medium and flow velocity can support the fuel design improvement in fuel assembly dynamics and structural integrity aspect. Because the upgraded requirements of the newly-developed advanced reactor system will demands to minimize fuel design margin in integrity evaluation, reduction in conservatism of fuel assembly damping can contribute to alleviate the fuel design margin for sure. Damping is an energy dissipation mechanism in a vibrating mechanical structure and prevents a resonant structure from having infinite vibration amplitudes. The sources of fuel assembly damping are various from support friction to flow contribution, and it can be increased by the viscosity or drag of surrounding fluid medium or the average velocity of water flowing. Fuel licensing requires fuel design evaluation in transient or accidental condition. Dynamic response analysis of fuel assembly is to show fuel integrity and requires information on assembly-wise damping in dry condition and under wet or water flowing condition. However, damping measurement test for the full-scale fuel assembly prototype is not easy to carry out because of the scale (fuel prototype, test facility), unsteadiness of test data (scattering, random sampling and processing), instrumentation under water flowing (water-proof response measurement), and noise. LWR fuel technology division in KAERI is preparing the infra structure for damping measurement test of full-scale fuel assembly, to support fuel industries and related research activities. Here is a preliminary summary of fuel assembly damping, published in the literature. Some technical issues in fuel assembly damping

  13. Self-assembled nanostructures

    CERN Document Server

    Zhang, Jin Z; Liu, Jun; Chen, Shaowei; Liu, Gang-yu

    2003-01-01

    Nanostructures refer to materials that have relevant dimensions on the nanometer length scales and reside in the mesoscopic regime between isolated atoms and molecules in bulk matter. These materials have unique physical properties that are distinctly different from bulk materials. Self-Assembled Nanostructures provides systematic coverage of basic nanomaterials science including materials assembly and synthesis, characterization, and application. Suitable for both beginners and experts, it balances the chemistry aspects of nanomaterials with physical principles. It also highlights nanomaterial-based architectures including assembled or self-assembled systems. Filled with in-depth discussion of important applications of nano-architectures as well as potential applications ranging from physical to chemical and biological systems, Self-Assembled Nanostructures is the essential reference or text for scientists involved with nanostructures.

  14. CDMA systems capacity engineering

    CERN Document Server

    Kim, Kiseon

    2004-01-01

    This new hands-on resource tackles capacity planning and engineering issues that are crucial to optimizing wireless communication systems performance. Going beyond the system physical level and investigating CDMA system capacity at the service level, this volume is the single-source for engineering and analyzing systems capacity and resources.

  15. PAYMENT CAPACITY SENSITIVITY FACTORS

    Directory of Open Access Journals (Sweden)

    Daniel BRÎNDESCU – OLARIU

    2014-11-01

    The results of the study facilitate the determination and classification of the main sensitivity factors for the payment capacity at sample level, the establishment of general benchmarks for the payment capacity (as no such benchmarks currently exist in the Romanian literature and the identification of the mechanisms through which the variation of different factors impacts the payment capacity.

  16. Model for the structure of the lipid bilayer

    International Nuclear Information System (INIS)

    Pastor, R.W.; Venable, R.M.; Karplus, M.

    1991-01-01

    A detailed model for the structure and dynamics of the interior of the lipid bilayer in the liquid crystal phase is presented. The model includes two classes of motion: (i) the internal dynamics of the chains, determined from Brownian dynamics simulations with a continuous version of the Marcelja mean-field potential, and (ii) noncollective reorientation (axial rotation and wobble) of the entire molecule, introduced by a cone model. The basic unit of the model is a single lipid chain with field parameters adjusted to fit the 2H order parameters and the frequency-dependent 13C NMR T1 relaxation times of dipalmitoyl phosphatidylcholine bilayers. The chain configurations obtained from the trajectory are used to construct a representation of the bilayer. The resulting lipid assembly is consistent with NMR, neutron diffraction, surface area, and density data. It indicates that a high degree of chain disorder and entanglement exists in biological membranes

  17. Preparation and self-assembly of amphiphilic polylysine dendrons

    DEFF Research Database (Denmark)

    Mirsharghi, Sahar; Knudsen, Kenneth D.; Bagherifam, Shahla

    2016-01-01

    Polylysine dendrons with lipid tails prepared by divergent solid-phase synthesis showed self-assembling properties in aqueous solutions., Herein, we present the synthesis of new amphiphilic polylysine dendrons with variable alkyl chain lengths (C1–C18) at the C-terminal. The dendrons were...... synthesized in moderate to quantitative yields by divergent solid-phase synthesis (SPS) employing an aldehyde linker. The self-assembling properties of the dendrons in aqueous solutions were studied by small angle neutron scattering (SANS) and dynamic light scattering (DLS). The self-assembling properties...... were influenced by the length of the alkyl chain and the generation number (Gn). Increasing the temperature and concentration did not have significant impact on the hydrodynamic diameter, but the self-assembling properties were influenced by the pH value. This demonstrated the need for positively...

  18. Effects of Ferulago angulata Extract on Serum Lipids and Lipid Peroxidation

    Directory of Open Access Journals (Sweden)

    Mahmoud Rafieian-kopaei

    2014-01-01

    Full Text Available Background. Nowadays, herbs they are considered to be the main source of effective drugs for lowering serum lipids and lipid peroxidation. The present experimental animal study aimed to assess the impact of Ferulago angulata on serum lipid profiles, and on levels of lipid peroxidation. Methods. Fifty male Wistar rats, weighing 250–300 g, were randomly divided into five equal groups (ten rats in each. The rat groups received different diets as follows: Group I: fat-rich diet; Group II: fat-rich diet plus hydroalcoholic extracts of Ferulago angulata at a dose of 400 mg/kg; Group III: fat-rich diet plus hydroalcoholic extracts of Ferulago angulata at a dose of 600 mg/kg; Group IV: fat-rich diet plus atorvastatin; Group V: common stock diet. The levels of serum glucose and lipids and the atherogenic index were measured. In addition, malondialdehyde (MDA, thiol oxidation, carbonyl concentrations, C-reactive proteins, and antioxidant capacity were evaluated in each group of rats. Results. Interestingly, by adding a hydroalcoholic extract of Ferulago angulata to the high-fat diet, the levels of total cholesterol and low-density lipoproteins (LDL in the high-fat diet rats were both significantly reduced. This result was considerably greater compared to when atorvastatin was added as an antilipid drug. The beneficial effects of the Ferulago angulata extract on lowering the level of triglycerides was observed only when a high dosage of this plant extraction was added to a high fat diet. Furthermore, the level of malondialdehyde, was significantly affected by the use of the plant extract in a high-fat diet, compared with a normal regimen or high-fat diet alone. Conclusion. Administration of a hydroalcoholic extract of Ferulago angulata can reduce serum levels of total cholesterol, triglycerides, and LDL. It can also inhibit lipid peroxidation.

  19. Ketone-body utilization and lipid synthesis by developing rat brain—a comparison between in vivo and in vitro experiments

    NARCIS (Netherlands)

    Klein, W.; Lopes-Cardozo, M.

    1984-01-01

    The distribution of ketone bodies between oxidation and lipid synthesis was analysed in homogenates of developing rat brain. The capacity for lipid synthesis of homogenized or minced brain preparations was compared with rates of lipid synthesis in vivo, assessed by incorporation of ³H from

  20. Watching individual molecules flex within lipid membranes using SERS

    Science.gov (United States)

    Taylor, Richard W.; Benz, Felix; Sigle, Daniel O.; Bowman, Richard W.; Bao, Peng; Roth, Johannes S.; Heath, George R.; Evans, Stephen D.; Baumberg, Jeremy J.

    2014-08-01

    Interrogating individual molecules within bio-membranes is key to deepening our understanding of biological processes essential for life. Using Raman spectroscopy to map molecular vibrations is ideal to non-destructively `fingerprint' biomolecules for dynamic information on their molecular structure, composition and conformation. Such tag-free tracking of molecules within lipid bio-membranes can directly connect structure and function. In this paper, stable co-assembly with gold nano-components in a `nanoparticle-on-mirror' geometry strongly enhances the local optical field and reduces the volume probed to a few nm3, enabling repeated measurements for many tens of minutes on the same molecules. The intense gap plasmons are assembled around model bio-membranes providing molecular identification of the diffusing lipids. Our experiments clearly evidence measurement of individual lipids flexing through telltale rapid correlated vibrational shifts and intensity fluctuations in the Raman spectrum. These track molecules that undergo bending and conformational changes within the probe volume, through their interactions with the environment. This technique allows for in situ high-speed single-molecule investigations of the molecules embedded within lipid bio-membranes. It thus offers a new way to investigate the hidden dynamics of cell membranes important to a myriad of life processes.

  1. 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.

  2. Microemulsion extrusion technique: a new method to produce lipid nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Jesus, Marcelo Bispo de, E-mail: dejesusmb@gmail.com; Radaic, Allan [University of Campinas-UNICAMP, Department of Biochemistry, Institute of Biology (Brazil); Zuhorn, Inge S. [University of Groningen, Department of Membrane Cell Biology, University Medical Center (Netherlands); Paula, Eneida de [University of Campinas-UNICAMP, Department of Biochemistry, Institute of Biology (Brazil)

    2013-10-15

    Solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) have been intensively investigated for different applications, including their use as drug and gene delivery systems. Different techniques have been employed to produce lipid nanoparticles, of which high pressure homogenization is the standard technique that is adopted nowadays. Although this method has a high efficiency, does not require the use of organic solvents, and allows large-scale production, some limitations impede its application at laboratory scale: the equipment is expensive, there is a need of huge amounts of surfactants and co-surfactants during the preparation, and the operating conditions are energy intensive. Here, we present the microemulsion extrusion technique as an alternative method to prepare lipid nanoparticles. The parameters to produce lipid nanoparticles using microemulsion extrusion were established, and the lipid particles produced (SLN, NLC, and liposomes) were characterized with regard to size (from 130 to 190 nm), zeta potential, and drug (mitoxantrone) and gene (pDNA) delivery properties. In addition, the particles' in vitro co-delivery capacity (to carry mitoxantrone plus pDNA encoding the phosphatase and tensin homologue, PTEN) was tested in normal (BALB 3T3 fibroblast) and cancer (PC3 prostate and MCF-7 breast) cell lines. The results show that the microemulsion extrusion technique is fast, inexpensive, reproducible, free of organic solvents, and suitable for small volume preparations of lipid nanoparticles. Its application is particularly interesting when using rare and/or costly drugs or ingredients (e.g., cationic lipids for gene delivery or labeled lipids for nanoparticle tracking/diagnosis)

  3. LRRK2 mediated Rab8a phosphorylation promotes lipid storage.

    Science.gov (United States)

    Yu, Miao; Arshad, Muhammad; Wang, Wenmin; Zhao, Dongyu; Xu, Li; Zhou, Linkang

    2018-02-27

    Several mutations in leucine rich repeat kinase 2 (LRRK2) gene have been associated with pathogenesis of Parkinson's disease (PD), a neurodegenerative disorder marked by resting tremors, and rigidity, leading to Postural instability. It has been revealed that mutations that lead to an increase of kinase activity of LRRK2 protein are significantly associated with PD pathogenesis. Recent studies have shown that some Rab GTPases, especially Rab8, serve as substrates of LRRK2 and undergo phosphorylation in its switch II domain upon interaction. Current study was performed in order to find out the effects of the phosphorylation of Rab8 and its mutants on lipid metabolism and lipid droplets growth. The phosphorylation status of Rab8a was checked by phos-tag gel. Point mutant construct were generated to investigate the function of Rab8a. 3T3L1 cells were transfected with indicated plasmids and the lipid droplets were stained with Bodipy. Fluorescent microscopy experiments were performed to examine the sizes of lipid droplets. The interactions between Rab8a and Optineurin were determined by immunoprecipitation and western blot. Our assays demonstrated that Rab8a was phosphorylated by mutated LRRK2 that exhibits high kinase activity. Phosphorylation of Rab8a on amino acid residue T72 promoted the formation of large lipid droplets. T72D mutant of Rab8a had higher activity to promote the formation of large lipid droplets compared with wild type Rab8a, with increase in average diameter of lipid droplets from 2.10 μm to 2.46 μm. Moreover, phosphorylation of Rab8a weakened the interaction with its effector Optineurin. Y1699C mutated LRRK2 was able to phosphorylate Rab8a and phosphorylation of Rab8a on site 72 plays important role in the fusion and enlargement of lipid droplets. Taken together, our study suggests an indirect relationship between enhanced lipid storage capacity and PD pathogenesis.

  4. 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

  5. Microemulsion extrusion technique: a new method to produce lipid nanoparticles

    International Nuclear Information System (INIS)

    Jesus, Marcelo Bispo de; Radaic, Allan; Zuhorn, Inge S.; Paula, Eneida de

    2013-01-01

    Solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) have been intensively investigated for different applications, including their use as drug and gene delivery systems. Different techniques have been employed to produce lipid nanoparticles, of which high pressure homogenization is the standard technique that is adopted nowadays. Although this method has a high efficiency, does not require the use of organic solvents, and allows large-scale production, some limitations impede its application at laboratory scale: the equipment is expensive, there is a need of huge amounts of surfactants and co-surfactants during the preparation, and the operating conditions are energy intensive. Here, we present the microemulsion extrusion technique as an alternative method to prepare lipid nanoparticles. The parameters to produce lipid nanoparticles using microemulsion extrusion were established, and the lipid particles produced (SLN, NLC, and liposomes) were characterized with regard to size (from 130 to 190 nm), zeta potential, and drug (mitoxantrone) and gene (pDNA) delivery properties. In addition, the particles’ in vitro co-delivery capacity (to carry mitoxantrone plus pDNA encoding the phosphatase and tensin homologue, PTEN) was tested in normal (BALB 3T3 fibroblast) and cancer (PC3 prostate and MCF-7 breast) cell lines. The results show that the microemulsion extrusion technique is fast, inexpensive, reproducible, free of organic solvents, and suitable for small volume preparations of lipid nanoparticles. Its application is particularly interesting when using rare and/or costly drugs or ingredients (e.g., cationic lipids for gene delivery or labeled lipids for nanoparticle tracking/diagnosis)

  6. Preparation and characterization of carnauba wax nanostructured lipid carriers containing benzophenone-3.

    Science.gov (United States)

    Lacerda, S P; Cerize, N N P; Ré, M I

    2011-08-01

    Nanostructured lipid carriers (NLCs) are potential active delivery systems based on mixtures of solid lipids and liquid oil. In this paper, aqueous dispersions of NLCs were prepared by a hot high-pressure homogenization technique using carnauba wax as the solid lipid and isodecyl oleate as the liquid oil. The preparation and stability parameters of benzophenone-3-loaded NLCs have been investigated concerning particle size, zeta potential and loading capacity to encapsulate benzophenone-3, a molecular sunscreen. The current investigation illustrates the effect of the composition of the lipid mixture on the entrapment efficiency, in vitro release and stability of benzophenone-3-loaded in these NLCs. A loading capacity of approximately 5% of benzophenone-3 (m(BZ-3) /m(lipids) ) was characteristic of these systems. © 2011 The Authors. ICS © 2011 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  7. Effects of dietary lipid levels on growth, body composition and antioxidants of clamworm (Perinereis aibuhitensis

    Directory of Open Access Journals (Sweden)

    Fu Lv

    2017-05-01

    Full Text Available To determine the effects of dietary lipid levels on growth performance, body composition and antioxidant parameters of clamworm (Perinereis aibuhitensis, 1050 clamworms were fed diets with seven lipid levels (2.37%, 4.35%, 6.29%, 8.41%, 10.31%, 12.29% and 14.33%, named L2.37, L4.35, L6.29, L8.41, L10.31, L12.29 and L14.33, respectively for 10 weeks. Each diet was randomly assigned to triplicate groups of 50 clamworms. The results showed that the growth performance and protein efficiency ratio were significantly affected by the lipid levels. Clamworms fed L8.41 diet exhibited higher growth performance than others and the maximum specific growth rate can be possibly obtained when the diets were supplemented with 7.54% lipid level. The dietary lipid levels had significant influences on the whole body crude protein, crude lipid, moisture contents and ash profile of P. aibuhitensis. The eicosapentaenoic acid (EPA and docosahexaenoic acid (DHA were also enhanced with increasing dietary lipid levels in whole body analyses. The contents of malonaldehyde (MDA and lipid peroxidation (LPO in clamworms increased significantly with increasing dietary lipid levels. Meanwhile, the activities of superoxide dismutase (SOD, catalase (CAT, glutathione peroxidase (GPX and total autioxidative capacity (T-AOC tended to strengthen with dietary lipid levels increasing from 2.37% to 10.31% (except the GPX with 12.29% dietary lipid levels, and weaken with dietary lipid levels increasing from 10.31% to 14.33%. These results demonstrated that a proper dietary lipid level of 7.54%–10.31% could maintain solid growth performance and antioxidant capacity of juvenile P. aibuhitensis.

  8. Bio-inspired nanocomposite assemblies as smart skin components.

    Energy Technology Data Exchange (ETDEWEB)

    Montano, Gabriel A.; Xiao, Xiaoyin; Achyuthan, Komandoor E.; Allen, Amy; Brozik, Susan Marie; Edwards, Thayne L.; Frischknecht, Amalie Lucile; Wheeler, David Roger

    2011-09-01

    There is national interest in the development of sophisticated materials that can automatically detect and respond to chemical and biological threats without the need for human intervention. In living systems, cell membranes perform such functions on a routine basis, detecting threats, communicating with the cell, and triggering automatic responses such as the opening and closing of ion channels. The purpose of this project was to learn how to replicate simple threat detection and response functions within artificial membrane systems. The original goals toward developing 'smart skin' assemblies included: (1) synthesizing functionalized nanoparticles to produce electrochemically responsive systems within a lipid bilayer host matrices, (2) calculating the energetics of nanoparticle-lipid interactions and pore formation, and (3) determining the mechanism of insertion of nanoparticles in lipid bilayers via imaging and electrochemistry. There are a few reports of the use of programmable materials to open and close pores in rigid hosts such as mesoporous materials using either heat or light activation. However, none of these materials can regulate themselves in response to the detection of threats. The strategies we investigated in this project involve learning how to use programmable nanomaterials to automatically eliminate open channels within a lipid bilayer host when 'threats' are detected. We generated and characterized functionalized nanoparticles that can be used to create synthetic pores through the membrane and investigated methods of eliminating the pores either through electrochemistry, change in pH, etc. We also focused on characterizing the behavior of functionalized gold NPs in different lipid membranes and lipid vesicles and coupled these results to modeling efforts designed to gain an understanding of the interaction of nanoparticles within lipid assemblies.

  9. Magnetic lipid nanoparticles loading doxorubicin for intracellular delivery: Preparation and characteristics

    International Nuclear Information System (INIS)

    Ying Xiaoying; Du Yongzhong; Hong Linghong; Yuan Hong; Hu Fuqiang

    2011-01-01

    Tumor intracellular delivery is an effective route for targeting chemotherapy to enhance the curative effect and minimize the side effect of a drug. In this study, the magnetic lipid nanoparticles with an uptake ability by tumor cells were prepared dispersing ferroso-ferric oxide nanoparticles in aqueous phase using oleic acid (OA) as a dispersant, and following the solvent dispersion of lipid organic solution. The obtained nanoparticles with 200 nm volume average diameter and -30 mV surface zeta potential could be completely removed by external magnetic field from aqueous solution. Using doxorubicin (DOX) as a model drug, the drug-loaded magnetic lipid nanoparticles were investigated in detail, such as the effects of OA, drug and lipid content on volume average diameter, zeta potential, drug encapsulation efficiency, drug loading, and in vitro drug release. The drug loading capacity and encapsulation efficiency were enhanced with increasing drug or lipid content, reduced with increasing OA content. The in vitro drug release could be controlled by changing drug or lipid content. Cellular uptake by MCF-7 cells experiment presented the excellent internalization ability of the prepared magnetic lipid nanoparticles. These results evidenced that the present magnetic lipid nanoparticles have potential for targeting therapy of antitumor drugs. - Research highlights: → A simple solvent diffusion method was developed to prepare magnetic lipid nanoparticles. → The doxorubicin-loaded magnetic lipid nanoparticles could be controlled by preparation recipe. → Magnetic lipid nanoparticles had internalization ability into tumor cells.

  10. TPX assembly plan

    International Nuclear Information System (INIS)

    Knutson, D.

    1993-01-01

    The TPX machine will be assembled in the TFTR Test Cell at the Plasma Physics Laboratory, utilizing the existing TFTR machine foundation. Preparation of the area for assembly will begin after completion of the decontamination and decommissioning phase on TFTR and certification that the radiation levels remaining, if any, are consistent with the types of operations planned. Assembly operations begin with the arrival of the first components, and conclude, approximately 24 months later, with the successful completion of the integrated systems tests and the achievement of a first plasma

  11. Nuclear reactor control assembly

    International Nuclear Information System (INIS)

    Negron, S.B.

    1991-01-01

    This patent describes an assembly for providing global power control in a nuclear reactor having the core split into two halves. It comprises a disk assembly formed from at least two disks each machined with an identical surface hole pattern such that rotation of one disk relative to the other causes the hole pattern to open or close, the disk assembly being positioned substantially at the longitudinal center of and coaxial with the core halves; and means for rotating at least one of the disks relative to the other

  12. Lipid peroxidation in liver homogenates. Effects of membrane lipid composition and irradiation

    International Nuclear Information System (INIS)

    Vaca, C.; Ringdahl, M.H.

    1984-01-01

    The rate of lipid peroxidation has been followed in whole liver homogenates from mice using the TBA-method. Liver homogenates with different membrane fatty acid composition were obtained from mice fed diets containing different sources of fat i.e. sunflower seed oil (S), coconut oil (C) and hydrogenated lard (L). The yields of the TBA-chromophore (TBA-c) were 4 times higher in the liver homogenates S compared to C and L after 4 hour incubation at 37 0 C. Irradiation of the liver homogenates before incubation inhibited the formation of lipid peroxidation products in a dose dependent way. The catalytic capacity of the homogenates was investigated, followed as the autooxidation of cysteamine or modified by addition of the metal chelator EDTA. The rate of autooxidation of cysteamine, which is dependent on the presence of metal ions (Fe/sup 2+/ or Cu/sup 2+/), was decreased with increasing dose, thus indicating an alteration in the availability of metal catalysts in the system. The addition of Fe/sup 2+/ to the system restored the lipid peroxidation yields in the irradiated systems and the presence of EDTA inhibited the formation of lipid peroxidation products in all three dietary groups. It is suggested that irradiation alters the catalytic activity needed in the autooxidation processes of polyunsaturated fatty acids

  13. Nuclear fuel assembly

    International Nuclear Information System (INIS)

    Anthony, A.J.

    1980-01-01

    A bimetallic spacer means is cooperatively associated with a nuclear fuel assembly and operative to resist the occurrence of in-reactor bowing of the nuclear fuel assembly. The bimetallic spacer means in one embodiment of the invention includes a space grid formed, at least principally, of zircaloy to the external surface of which are attached a plurality of stainless steel strips. In another embodiment the strips are attached to fuel pins. In each of the embodiments, the stainless steel strips during power production expand outwardly to a greater extent than do the members to which the stainless steel strips are attached, thereby forming stiff springs which abut against like bimetallic spacer means with which the other nuclear fuel assemblies are provided in a given nuclear reactor core to thus prevent the occurrence of in-reactor bowing of the nuclear fuel assemblies. (author)

  14. Fuel assembly spacer

    International Nuclear Information System (INIS)

    Shirakawa, Ken-etsu.

    1988-01-01

    Purpose: To reduce the pressure loss of coolants by fuel assembly spacers. Constitution: Spacers for supporting a fuel assembly are attached by means of a plurality of wires to an outer frame. The outer frame is made of shape memory alloy such that the wires are caused to slacken at normal temperature and the slacking of the wires is eliminated in excess of the transition temperature. Since the wires slacken at the normal temperature, fuel rods can be inserted easily. After the insertion of the fuel rods, when the entire portion or the outer frame is heated by water or gas at a predetermined temperature, the outer frame resumes its previously memorized shape to tighten the wires and, accordingly, the fuel rods can be supported firmly. In this way, since the fuel rods are inserted in the slacken state of the wires and, after the assembling, the outer frame resumes its memorized shape, the assembling work can be conducted efficiently. (Kamimura, M.)

  15. Nuclear reactor spacer assembly

    International Nuclear Information System (INIS)

    Anthony, A.J.; Groves, M.D.

    1979-01-01

    A fuel assembly for a nuclear reactor is disclosed wherein the fuel element receiving and supporting grid is comprised of a first metal, the guide tubes which pass through the grid assembly are comprised of a second metal and the grid is supported on the guide tubes by means of expanded sleeves located intermediate the grid and guide tubes. The fuel assembly is fabricated by inserting the sleeves, of initial outer diameter commensurate with the guide tube outer diameters, through the holes in the grid assembly provided for the guide tubes and thereafter expanding the sleeves radially outwardly along their entire length such that the guide tubes can subsequently be passed through the sleeves. The step of radial expansion, as a result of windows provided in the sleeves having dimensions commensurate with the geometry of the grid, mechanically captures the grid and simultaneously preloads the sleeve against the grid whereby relative motion between the grid and guide tube will be precluded

  16. Nuclear reactor fuel assembly

    International Nuclear Information System (INIS)

    Vikhorev, Yu.V.; Biryukov, G.I.; Kirilyuk, N.A.; Lobanov, V.N.

    1977-01-01

    A fuel assembly is proposed for nuclear reactors allowing remote replacement of control rod bundles or their shifting from one assembly to another, i.e., their multipurpose use. This leads to a significant increase in fuel assembly usability. In the fuel assembly the control rod bundle is placed in guide tube channels to which baffles are attached for fuel element spacing. The remote handling of control rods is provided by a hollow cylinder with openings in its lower bottom through which the control rods pass. All control rods in a bundle are mounted to a cross beam which in turn is mounted in the cylinder and is designed for grasping the whole rod bundle by a remotely controlled telescopic mechanism in bundle replacement or shifting. (Z.M.)

  17. Nuclear fuel assembly

    International Nuclear Information System (INIS)

    Betten, P.R.

    1976-01-01

    Under the invention the fuel assembly is particularly suitable for liquid metal cooled fast neutron breeder reactors. Hence, according to the invention a fuel assembly cladding includes inward corrugations with respect to the remainder of the cladding according to a recurring pattern determined by the pitch of the metal wire helically wound round the fuel rods of the assembly. The parts of the cladding pressed inwards correspond to the areas in which the wire encircling the peripheral fuel rods is generally located apart from the cladding, thereby reducing the play between the cladding and the peripheral fuel rods situated in these areas. The reduction in the play in turn improves the coolant flow in the internal secondary channels of the fuel assembly to the detriment of the flow in the peripheral secondary channels and thereby establishes a better coolant fluid temperature profile [fr

  18. Nuclear reactor fuel assembly

    International Nuclear Information System (INIS)

    Sakurai, Shungo; Ogiya, Shunsuke.

    1990-01-01

    In a fuel assembly, if the entire fuels comprise mixed oxide fuels, reactivity change in cold temperature-power operation is increased to worsen the reactor shutdown margin. The reactor shutdown margin has been improved by increasing the burnable poison concentration thereby reducing the reactivity of the fuel assembly. However, since unburnt poisons are present at the completion of the reactor operation, the reactivity can not be utilized effectively to bring about economical disadvantage. In view of the above, the reactivity change between lower temperature-power operations is reduced by providing a non-boiling range with more than 9.1% of cross sectional area at the inside of a channel at the central portion of the fuel assembly. As a result, the amount of the unburnt burnable poisons is decreased, the economy of fuel assembly is improved and the reactor shutdown margin can be increase. (N.H.)

  19. 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...

  20. Capacity planning and management

    OpenAIRE

    Boydell, Briony

    2011-01-01

    After reading this chapter you should be able to: • Define and measure capacity and appreciate the factors that influence it. • Assess the difficulties of matching capacity to demand. • Evaluate and apply the different strategies for matching capacity with demand in the short, medium and long term. • Analyse the impact of constraints and bottlenecks on a process and consider the Theory of Constraints. • Outline the different strategies available for both manufacturing and service operations. ...

  1. Fuel assembly reconstitution

    International Nuclear Information System (INIS)

    Morgado, Mario M.; Oliveira, Monica G.N.; Ferreira Junior, Decio B.M.; Santos, Barbara O. dos; Santos, Jorge E. dos

    2009-01-01

    Fuel failures have been happened in Nuclear Power Plants worldwide, without lost of integrity and safety, mainly for the public, environment and power plants workers. The most common causes of these events are corrosion (CRUD), fretting and pellet cladding interaction. These failures are identified by increasing the activity of fission products, verified by chemical analyses of reactor coolant. Through these analyses, during the fourth operation cycle of Angra 2 Nuclear Power Plant, was possible to observe fuel failure indication. This indication was confirmed in the end of the cycle during the unloading of reactor core through leakage tests of fuel assembly, using the equipment called 'In Mast Sipping' and 'Box Sipping'. After confirmed, the fuel assembly reconstitution was scheduled, and happened in April, 2007, where was identified the cause and the fuel rod failure, which was substitute by dummy rods (zircaloy). The cause was fretting by 'debris'. The actions to avoid and prevent fuel assemblies failures are important. The goals of this work are to describe the methodology of fuel assembly reconstitution using the FARE (Fuel Assembly Reconstitution Equipment) system, to describe the results of this task in economic and security factors of the company and show how the fuel assembly failures are identified during operation and during the outage. (author)

  2. Polymer Directed Protein Assemblies

    Directory of Open Access Journals (Sweden)

    Patrick van Rijn

    2013-05-01

    Full Text Available Protein aggregation and protein self-assembly is an important occurrence in natural systems, and is in some form or other dictated by biopolymers. Very obvious influences of biopolymers on protein assemblies are, e.g., virus particles. Viruses are a multi-protein assembly of which the morphology is dictated by poly-nucleotides namely RNA or DNA. This “biopolymer” directs the proteins and imposes limitations on the structure like the length or diameter of the particle. Not only do these bionanoparticles use polymer-directed self-assembly, also processes like amyloid formation are in a way a result of directed protein assembly by partial unfolded/misfolded biopolymers namely, polypeptides. The combination of proteins and synthetic polymers, inspired by the natural processes, are therefore regarded as a highly promising area of research. Directed protein assembly is versatile with respect to the possible interactions which brings together the protein and polymer, e.g., electrostatic, v.d. Waals forces or covalent conjugation, and possible combinations are numerous due to the large amounts of different polymers and proteins available. The protein-polymer interacting behavior and overall morphology is envisioned to aid in clarifying protein-protein interactions and are thought to entail some interesting new functions and properties which will ultimately lead to novel bio-hybrid materials.

  3. Enhanced lipid extraction from microalgae in biodiesel production

    Directory of Open Access Journals (Sweden)

    Kim Myung-Gyun

    2017-01-01

    Full Text Available In order to secure more effective lipid extraction method, this research investigated new lipid extraction method using laser with absorbent and sought its optimum operation control. In addition, this study compared lipid extraction efficiency and FAME conversion rate between laser extraction method at optimum condition and existing extraction method. Results from experiments for optimizing lipid extraction method using laser showed that the maximum extraction efficiency (81.8% was attained when using laser with an output capacity of 75Wh/L. Extraction efficiency increased up to 90.8% when microwave treatment as pretreatment process was conducted. Addition of absorbents during lipid extraction process with laser showed higher extraction efficiency than laser and chemical method. It was also found that laser extraction method with absorbent had higher total fatty acid content (853.7 mg/g oil in extracted lipid than chemical extraction method (825.4 mg/g oil. Furthermore, it had the highest FAME conversion rate (94.2%.

  4. The French capacity mechanism

    International Nuclear Information System (INIS)

    2014-01-01

    The French capacity mechanism has been design to ensure security of supply in the context of the energy transition. This energy transition challenges the electricity market design with several features: peak load growth, the development of renewables, demand response,... To ensure security of supply in this context, a capacity mechanism is being implemented in France. It is a market wide capacity obligation on electricity suppliers, based on market principles. Suppliers are responsible for forecasting their obligation, which corresponds to their contribution to winter peak load, and must procure enough capacity certificates to meet their obligations. Capacity certificates are granted to capacities through a certification process, which assesses their contribution to security of supply on the basis of availability commitments. This certification process is technology neutral and performance based, associated with controls and penalties in case of non compliance. Demand Side is fully integrated in the market, either through the reduction of suppliers' capacity obligation or direct participation after certification. In addition to the expected benefits in terms of security of supply, the French capacity market will foster the development of demand response. The participation of foreign capacities will require adaptations which are scheduled in a road-map, and could pave the way for further European integration of energy policies. (authors)

  5. Mitochondrial mass is inversely correlated to complete lipid oxidation in human myotubes

    DEFF Research Database (Denmark)

    Gaster, Michael

    2011-01-01

    Exercise increases while physical inactivity decrease mitochondrial content and oxidative capacity of skeletal muscles in vivo. It is unknown whether mitochondrial mass and substrate oxidation are related in non-contracting skeletal muscle. Mitochondrial mass, ATP, ADP, AMP, glucose and lipid......, basal glucose oxidation and incomplete lipid oxidation were significantly increased while complete lipid oxidation was lower. Mitochondrial mass was not correlated to glucose oxidation or incomplete lipid oxidation in human myotubes but inversely correlated to complete lipid oxidation. Thus within...... a stable energetic background, an increased mitochondrial mass in human myotubes was not positive correlated to an increased substrate oxidation as expected from skeletal muscles in vivo but surprisingly with a reduced complete lipid oxidation....

  6. Observation of undulation motion of lipid bilayers by neutron spin echo

    International Nuclear Information System (INIS)

    Yamada, Norifumi L.; Seto, Hideki; Hishida, Mafumi

    2010-01-01

    Aqueous solutions of synthesized phospholipids have been well investigated as model biomembranes. These lipids usually self-assemble into regular stacks of bilayers with a characteristic repeat distance on the order of nm, whereas real biomembrane exist as single bilayers. The key phenomenon in understanding the formation of single isolated bilayers in 'unbinding' of lipid bilayers, in which the inter-bilayer distance of lipid bilayers diverges by the steric interaction due to the membrane undulation. In this paper, we show some results of neutron spin-echo (NSE) experiments to investigate the effect of the steric interaction on unbinding and related phenomena. (author)

  7. Effect of tofacitinib on lipid levels and lipid-related parameters in patients with moderate to severe psoriasis.

    Science.gov (United States)

    Wolk, Robert; Armstrong, Ehrin J; Hansen, Peter R; Thiers, Bruce; Lan, Shuping; Tallman, Anna M; Kaur, Mandeep; Tatulych, Svitlana

    Psoriasis is a systemic inflammatory disease associated with increased cardiovascular (CV) risk and altered lipid metabolism. Tofacitinib is an oral Janus kinase inhibitor. The aim of the study was to investigate the effects of tofacitinib on traditional and nontraditional lipid parameters and CV risk markers in patients with psoriasis from a phase III study, OPT Pivotal 1. Patients with psoriasis were randomized to tofacitinib 5 or 10 mg twice daily (BID) or placebo BID. Serum samples were collected at baseline, week 4, and week 16. Analyses included serum cholesterol levels, triglycerides, lipoproteins, lipid particles, lipid-related parameters/CV risk markers, and high-density lipoprotein (HDL) function analyses. At week 16, small concurrent increases in mean low-density lipoprotein cholesterol (LDL-C) and HDL cholesterol (HDL-C) levels were observed with tofacitinib; total cholesterol/HDL-C ratio did not change. There was no significant change in the number of small dense LDL particles, which are considered to be more atherogenic than large particles, and oxidized LDL did not increase. Paraoxonase 1 activity, linked to HDL antioxidant capacity, increased, and HDL-associated serum amyloid A, which reduces the anti-atherogenic potential of HDL, decreased. HDL capacity to promote cholesterol efflux from macrophages did not change. Lecithin-cholesterol acyltransferase activity, which is associated with reverse cholesterol transport, increased. Markers of systemic inflammation, serum amyloid A and C-reactive protein, decreased with tofacitinib. While small increases in lipid levels are observed with tofacitinib treatment in patients with psoriasis, effects on selected lipid-related parameters and other circulating CV risk biomarkers are not suggestive of an increased CV risk [NCT01276639]. Copyright © 2017 National Lipid Association. Published by Elsevier Inc. All rights reserved.

  8. 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

  9. Thermodynamics of interaction of ionic liquids with lipid monolayer.

    Science.gov (United States)

    Bhattacharya, G; Mitra, S; Mandal, P; Dutta, S; Giri, R P; Ghosh, S K

    2018-06-01

    Understanding the interaction of ionic liquids with cellular membrane becomes utterly important to comprehend the activities of these liquids in living organisms. Lipid monolayer formed at the air-water interface is employed as a model system to follow this interaction by investigating important thermodynamic parameters. The penetration kinetics of the imidazolium-based ionic liquid 1-decyl-3-methylimidazolium tetrafluoroborate ([DMIM][BF4]) into the zwitterionic 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) lipid layer is found to follow the Boltzmann-like equation that reveals the characteristic time constant which is observed to be the function of initial surface pressure. The enthalpy and entropy calculated from temperature-dependent pressure-area isotherms of the monolayer show that the added ionic liquids bring about a disordering effect in the lipid film. The change in Gibbs free energy indicates that an ionic liquid with longer chain has a far greater disordering effect compared to an ionic liquid with shorter chain. The differential scanning calorimetric measurement on a multilamellar vesicle system shows the main phase transition temperature to shift to a lower value, which, again, indicates the disordering effect of the ionic liquid on lipid membrane. All these studies fundamentally point out that, when ionic liquids interact with lipid molecules, the self-assembled structure of a cellular membrane gets perturbed, which may be the mechanism of these molecules having adverse effects on living organisms.

  10. Human Assisted Assembly Processes

    Energy Technology Data Exchange (ETDEWEB)

    CALTON,TERRI L.; PETERS,RALPH R.

    2000-01-01

    Automatic assembly sequencing and visualization tools are valuable in determining the best assembly sequences, but without Human Factors and Figure Models (HFFMs) it is difficult to evaluate or visualize human interaction. In industry, accelerating technological advances and shorter market windows have forced companies to turn to an agile manufacturing paradigm. This trend has promoted computerized automation of product design and manufacturing processes, such as automated assembly planning. However, all automated assembly planning software tools assume that the individual components fly into their assembled configuration and generate what appear to be a perfectly valid operations, but in reality the operations cannot physically be carried out by a human. Similarly, human figure modeling algorithms may indicate that assembly operations are not feasible and consequently force design modifications; however, if they had the capability to quickly generate alternative assembly sequences, they might have identified a feasible solution. To solve this problem HFFMs must be integrated with automated assembly planning to allow engineers to verify that assembly operations are possible and to see ways to make the designs even better. Factories will very likely put humans and robots together in cooperative environments to meet the demands for customized products, for purposes including robotic and automated assembly. For robots to work harmoniously within an integrated environment with humans the robots must have cooperative operational skills. For example, in a human only environment, humans may tolerate collisions with one another if they did not cause much pain. This level of tolerance may or may not apply to robot-human environments. Humans expect that robots will be able to operate and navigate in their environments without collisions or interference. The ability to accomplish this is linked to the sensing capabilities available. Current work in the field of cooperative

  11. 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...

  12. Lipid rafts generate digital-like signal transduction in cell plasma membranes.

    Science.gov (United States)

    Suzuki, Kenichi G N

    2012-06-01

    Lipid rafts are meso-scale (5-200 nm) cell membrane domains where signaling molecules assemble and function. However, due to their dynamic nature, it has been difficult to unravel the mechanism of signal transduction in lipid rafts. Recent advanced imaging techniques have revealed that signaling molecules are frequently, but transiently, recruited to rafts with the aid of protein-protein, protein-lipid, and/or lipid-lipid interactions. Individual signaling molecules within the raft are activated only for a short period of time. Immobilization of signaling molecules by cytoskeletal actin filaments and scaffold proteins may facilitate more efficient signal transmission from rafts. In this review, current opinions of how the transient nature of molecular interactions in rafts generates digital-like signal transduction in cell membranes, and the benefits this phenomenon provides, are discussed. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Heat Capacity Analysis Report

    International Nuclear Information System (INIS)

    Findikakis, A.

    2004-01-01

    The purpose of this report is to provide heat capacity values for the host and surrounding rock layers for the waste repository at Yucca Mountain. The heat capacity representations provided by this analysis are used in unsaturated zone (UZ) flow, transport, and coupled processes numerical modeling activities, and in thermal analyses as part of the design of the repository to support the license application. Among the reports that use the heat capacity values estimated in this report are the ''Multiscale Thermohydrologic Model'' report, the ''Drift Degradation Analysis'' report, the ''Ventilation Model and Analysis Report, the Igneous Intrusion Impacts on Waste Packages and Waste Forms'' report, the ''Dike/Drift Interactions report, the Drift-Scale Coupled Processes (DST and TH Seepage) Models'' report, and the ''In-Drift Natural Convection and Condensation'' report. The specific objective of this study is to determine the rock-grain and rock-mass heat capacities for the geologic stratigraphy identified in the ''Mineralogic Model (MM3.0) Report'' (BSC 2004 [DIRS 170031], Table 1-1). This report provides estimates of the heat capacity for all stratigraphic layers except the Paleozoic, for which the mineralogic abundance data required to estimate the heat capacity are not available. The temperature range of interest in this analysis is 25 C to 325 C. This interval is broken into three separate temperature sub-intervals: 25 C to 95 C, 95 C to 114 C, and 114 C to 325 C, which correspond to the preboiling, trans-boiling, and postboiling regimes. Heat capacity is defined as the amount of energy required to raise the temperature of a unit mass of material by one degree (Nimick and Connolly 1991 [DIRS 100690], p. 5). The rock-grain heat capacity is defined as the heat capacity of the rock solids (minerals), and does not include the effect of water that exists in the rock pores. By comparison, the rock-mass heat capacity considers the heat capacity of both solids and pore

  14. Fabrication of dendrimer-releasing lipidic nanoassembly for cancer drug delivery.

    Science.gov (United States)

    Sun, Qihang; Ma, Xinpeng; Zhang, Bo; Zhou, Zhuxian; Jin, Erlei; Shen, Youqing; Van Kirk, Edward A; Murdoch, William J; Radosz, Maciej; Sun, Weilin

    2016-06-24

    An inherent dilemma in the use of nanomedicines for cancer drug delivery is their limited penetration into tumors due to their large size. We have demonstrated that dendrimer/lipid nanoassemblies can solve this problem by means of tumor-triggered disassembly and the release of small (several nanometers) dendrimers to facilitate tumor penetration. Herein, we report a general strategy for the fabrication of nanoassemblies from hydrophobic and hydrophilic dendrimers with phospholipids. Hydrophobic dendrimers could assemble with lipids via hydrophobic interactions, whereas hydrophilic dendrimers could only assemble with lipids in the presence of anionic surfactants via both electrostatic and hydrophobic interactions. The nanoassemblies of hydrophobic dendrimers/lipids were found to be capable of stripping off their lipid layers via fusion with the cell membrane and then intracellular or extracellular release of dendrimers, whereas the nanoassemblies of hydrophilic dendrimers/lipids were internalized via endocytosis and then released their dendrimers inside the cells. Therefore, these dendrimer/lipid nanoassemblies could be used for the delivery of different cancer drugs.

  15. 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.

  16. Octanol-assisted liposome assembly on chip

    Science.gov (United States)

    Deshpande, Siddharth; Caspi, Yaron; Meijering, Anna E. C.; Dekker, Cees

    2016-01-01

    Liposomes are versatile supramolecular assemblies widely used in basic and applied sciences. Here we present a novel microfluidics-based method, octanol-assisted liposome assembly (OLA), to form monodisperse, cell-sized (5-20 μm), unilamellar liposomes with excellent encapsulation efficiency. Akin to bubble blowing, an inner aqueous phase and a surrounding lipid-carrying 1-octanol phase is pinched off by outer fluid streams. Such hydrodynamic flow focusing results in double-emulsion droplets that spontaneously develop a side-connected 1-octanol pocket. Owing to interfacial energy minimization, the pocket splits off to yield fully assembled solvent-free liposomes within minutes. This solves the long-standing fundamental problem of prolonged presence of residual oil in the liposome bilayer. We demonstrate the unilamellarity of liposomes with functional α-haemolysin protein pores in the membrane and validate the biocompatibility by inner leaflet localization of bacterial divisome proteins (FtsZ and ZipA). OLA offers a versatile platform for future analytical tools, delivery systems, nanoreactors and synthetic cells.

  17. WHO: World Health Assembly.

    Science.gov (United States)

    McGregor, A

    1992-05-23

    1200 delegates from 175 member countries attended the 45th World Health Assembly in Geneva. Everyone at the Assembly ratified measures to prevent and control AIDS. 12 countries intended to do long term planning for community based care for AIDS patients. Further the Assembly denounced instances where countries and individuals denied the gravity of the AIDS pandemic. In fact, it expressed the importance for urgent and intensive action against HIV/AIDS. The assembly backed proposals to prevent and control sexually transmitted diseases that affect AIDS patients, especially hepatitis B. For example, in countries with hepatitis B prevalence 8% (many countries in Sub-Sahara Africa, Asia, the Pacific region, and South America), health officials should introduce hepatitis B vaccine into their existing immunization programs by 1995. By 1997, this vaccine should be part of all immunization programs. The Assembly was aware of the obstacles of establishing reliable cold chains for nationwide distribution, however. Delegates in Committee A objected to the fact that 50% of the populations of developing countries continued to have limited access to essential drugs. They also expressed disapproval in implementation of WHO's 1988 ethical criteria for promotion of drugs which WHO entrusted to the Council for International Organisations of Medical Sciences (CIOMS). CIOMS lacked WHO's status and thus could not effectively monitor drug advertising. In fact, the pharmaceutical industry as well as WHO provided the funds for a meeting of 25 experts to discuss principles included in the ethical criteria. At least 4 countries insisted that WHO have the ultimate authority in monitoring drug advertising. Delegates did adopt a compromise resolution on this topic which required that industry promotion methods be reported to the 1994 Assembly via the Executive Board. The Assembly requested WHO to establish an international advisory committee on nursing and midwifery and to improve the network of

  18. Dynamic behaviour of diagnostic assemblies

    International Nuclear Information System (INIS)

    Pecinka, L.

    1980-01-01

    The methodology is shown of calculating the frequency spectrum of a diagnostic assembly. The oscillations of the assembly as a whole, of a fuel rod bundle, the assembly jacket and of the individual rods in the bundle were considered. The manufacture is suggested of a model assembly which would be used for testing forced vibrations using an experimental water loop. (M.S.)

  19. Prospects for OPEC capacity

    International Nuclear Information System (INIS)

    Adelman, M.A.

    1995-01-01

    OPEC capacity is not exogenous, but responds to demand. Price increases have not been caused by capacity shortages. OPEC nations find it hard to set aside even very small portions of their revenues for oil investment, despite its extreme profitability. Foreign investors face high risks. Production sharing makes their after-tax return even more unstable. (author)

  20. Optimization and characterization of stable lipid-based, oxygen-filled microbubbles by mixture design.

    Science.gov (United States)

    Polizzotti, Brian D; Thomson, Lindsay M; O'Connell, Daniel W; McGowan, Francis X; Kheir, John N

    2014-08-01

    Tissue hypoxia is a final common pathway that leads to cellular injury and death in a number of critical illnesses. Intravenous injections of self-assembling, lipid-based oxygen microbubbles (LOMs) can be used to deliver oxygen gas, preventing organ injury and death from systemic hypoxemia. However, current formulations exhibit high polydispersity indices (which may lead to microvascular obstruction) and poor shelf-lives, limiting the translational capacity of LOMs. In this study, we report our efforts to optimize LOM formulations using a mixture response surface methodology (mRSM). We study the effect of changing excipient proportions (the independent variables) on microbubble diameter and product loss (the dependent variables). By using mRSM analysis, the experimental data were fit using a reduced Scheffé linear mixture model. We demonstrate that formulations manufactured from 1,2-distearoyl-sn-glycero-3-phosphocholine, corn syrup, and water produce micron-sized microbubbles with low polydispersity indices, and decreased product loss (relative to previously described formulations) when stored at room temperature over a 30-day period. Optimized LOMs were subsequently tested for their oxygen-releasing ability and found to have similar release kinetics as prior formulations. © 2014 Wiley Periodicals, Inc.

  1. Uncertainty in adaptive capacity

    International Nuclear Information System (INIS)

    Neil Adger, W.; Vincent, K.

    2005-01-01

    The capacity to adapt is a critical element of the process of adaptation: it is the vector of resources that represent the asset base from which adaptation actions can be made. Adaptive capacity can in theory be identified and measured at various scales, from the individual to the nation. The assessment of uncertainty within such measures comes from the contested knowledge domain and theories surrounding the nature of the determinants of adaptive capacity and the human action of adaptation. While generic adaptive capacity at the national level, for example, is often postulated as being dependent on health, governance and political rights, and literacy, and economic well-being, the determinants of these variables at national levels are not widely understood. We outline the nature of this uncertainty for the major elements of adaptive capacity and illustrate these issues with the example of a social vulnerability index for countries in Africa. (authors)

  2. A Coarse Grained Model for a Lipid Membrane with Physiological Composition and Leaflet Asymmetry.

    Directory of Open Access Journals (Sweden)

    Satyan Sharma

    Full Text Available The resemblance of lipid membrane models to physiological membranes determines how well molecular dynamics (MD simulations imitate the dynamic behavior of cell membranes and membrane proteins. Physiological lipid membranes are composed of multiple types of phospholipids, and the leaflet compositions are generally asymmetric. Here we describe an approach for self-assembly of a Coarse-Grained (CG membrane model with physiological composition and leaflet asymmetry using the MARTINI force field. An initial set-up of two boxes with different types of lipids according to the leaflet asymmetry of mammalian cell membranes stacked with 0.5 nm overlap, reliably resulted in the self-assembly of bilayer membranes with leaflet asymmetry resembling that of physiological mammalian cell membranes. Self-assembly in the presence of a fragment of the plasma membrane protein syntaxin 1A led to spontaneous specific positioning of phosphatidylionositol(4,5bisphosphate at a positively charged stretch of syntaxin consistent with experimental data. An analogous approach choosing an initial set-up with two concentric shells filled with different lipid types results in successful assembly of a spherical vesicle with asymmetric leaflet composition. Self-assembly of the vesicle in the presence of the synaptic vesicle protein synaptobrevin 2 revealed the correct position of the synaptobrevin transmembrane domain. This is the first CG MD method to form a membrane with physiological lipid composition as well as leaflet asymmetry by self-assembly and will enable unbiased studies of the incorporation and dynamics of membrane proteins in more realistic CG membrane models.

  3. Fuel assembly inspection device

    International Nuclear Information System (INIS)

    Yaginuma, Yoshitaka

    1998-01-01

    The present invention provides a device suitable to inspect appearance of fuel assemblies by photographing the appearance of fuel assemblies. Namely, the inspection device of the present invention measures bowing of fuel assembly or each of fuel rods or both of them based on the partially photographed images of fuel assembly. In this case, there is disposed a means which flashily projects images in the form of horizontal line from a direction intersecting obliquely relative to a horizontal cross section of the fuel assembly. A first image processing means separates the projected image pictures including projected images and calculates bowing. A second image processing means replaces the projected image pictures of the projected images based on projected images just before and after the photographing. Then, images for the measurement of bowing and images for inspection can be obtained simultaneously. As a result, the time required for the photographing can be shortened, the time for inspection can be shortened and an effect of preventing deterioration of photographing means by radiation rays can be provided. (I.S.)

  4. 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

  5. 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

  6. 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...

  7. 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)

  8. Optimization of cultivation conditions for biotechnological production of lipid by Rhodotorula kratochvilovae (syn, Rhodosporidium kratochvilovae) SY89 for biodiesel preparation

    NARCIS (Netherlands)

    Jiru, Tamene Milkessa; Groenewald, Marizeth; Pohl, Carolina; Steyn, Laurinda; Kiggundu, Nicholas; Abate, Dawit

    Rhodotorula kratochvilovae (syn, Rhodosporidium kratochvilovae) SY89, an oleaginous yeast, isolated from Ethiopian soil, was grown under nitrogen-limited media. The capacity this with respect to biomass production, lipid yield and lipid content was evaluated. The influence of inoculum size, carbon

  9. Blade attachment assembly

    Science.gov (United States)

    Garcia-Crespo, Andres Jose; Delvaux, John McConnell; Miller, Diane Patricia

    2016-05-03

    An assembly and method for affixing a turbomachine rotor blade to a rotor wheel are disclosed. In an embodiment, an adaptor member is provided disposed between the blade and the rotor wheel, the adaptor member including an adaptor attachment slot that is complementary to the blade attachment member, and an adaptor attachment member that is complementary to the rotor wheel attachment slot. A coverplate is provided, having a coverplate attachment member that is complementary to the rotor wheel attachment slot, and a hook for engaging the adaptor member. When assembled, the coverplate member matingly engages with the adaptor member, and retains the blade in the adaptor member, and the assembly in the rotor wheel.

  10. Reactor and fuel assembly

    International Nuclear Information System (INIS)

    Ishii, Yoshihiko; Bessho, Yasunori; Sano, Hiroki; Yokomizo, Osamu; Yamashita, Jun-ichi.

    1990-01-01

    The present invention realizes an effective spectral operation by applying an optimum pressure loss coefficient while taking the characteristics of a lower tie plate into consideration. That is, the pressure loss coefficient of the lower tie plate is optimized by varying the cross sectional area of a fuel assembly flow channel in the lower tie plate or varying the surface roughness of a coolant flow channel in the lower tie plate. Since there is a pressure loss coefficient to optimize the moderator density over a flow rate change region, the effect of spectral shift rods can be improved by setting the optimum pressure loss coefficient of the lower tie plate. According to the present invention, existent fuel assemblies can easily be changed successively to fuel assemblies having spectral shift rods of a great spectral shift effect by using existent reactor facilities as they are. (I.S.)

  11. Power module assembly

    Science.gov (United States)

    Campbell, Jeremy B [Torrance, CA; Newson, Steve [Redondo Beach, CA

    2011-11-15

    A power module assembly of the type suitable for deployment in a vehicular power inverter, wherein the power inverter has a grounded chassis, is provided. The power module assembly comprises a conductive base layer electrically coupled to the chassis, an insulating layer disposed on the conductive base layer, a first conductive node disposed on the insulating layer, a second conductive node disposed on the insulating layer, wherein the first and second conductive nodes are electrically isolated from each other. The power module assembly also comprises a first capacitor having a first electrode electrically connected to the conductive base layer, and a second electrode electrically connected to the first conductive node, and further comprises a second capacitor having a first electrode electrically connected to the conductive base layer, and a second electrode electrically connected to the second conductive node.

  12. Magnetic nanoparticle assemblies

    CERN Document Server

    Trohidou, Kalliopi N

    2014-01-01

    Magnetic nanoparticles with diameters in the range of a few nanometers are today at the cutting edge of modern technology and innovation because of their use in numerous applications ranging from engineering to biomedicine. A great deal of scientific interest has been focused on the functionalization of magnetic nanoparticle assemblies. The understanding of interparticle interactions is necessary to clarify the physics of these assemblies and their use in the development of high-performance magnetic materials. This book reviews prominent research studies on the static and dynamic magnetic properties of nanoparticle assemblies, gathering together experimental and computational techniques in an effort to reveal their optimized magnetic properties for biomedical use and as ultra-high magnetic recording media.

  13. Reactor fuel assembly

    International Nuclear Information System (INIS)

    Anthony, A.J.; Groves, M.D.

    1980-01-01

    A nuclear reactor fuel assembly having a lower end fitting and actuating means interacting therewith for holding the assembly down on the core support stand against the upward flow of coolant. Locking means for interacting with projections on the support stand are carried by the lower end fitting and are actuated by the movement of an actuating rod operated from above the top of the assembly. In one embodiment of the invention the downward movement of the actuating rod forces a latched spring to move outward into locking engagement with a shoulder on the support stand projections. In another embodiment, the actuating rod is rotated to effect the locking between the end fitting and the projection. (author)

  14. Nuclear fuel assembly

    International Nuclear Information System (INIS)

    Hayashi, Hiroshi; Watari, Yoshio; Hizahara, Hiroshi; Masuoka, Ryuzo.

    1970-01-01

    When exchanging nuclear fuel assemblies during the operation of a nuclear reactor, melting of fuel bodies, and severence of tubular claddings is halted at the time of insertion by furnishing a neutron absorbing material such as B 10 , Cd, Gd or the like at the forward end of the fuel assembly to thereby lower the power peak at the forward ends of the fuel elements to within tolerable levels and thus prevent both fuel liquification and excessive expansion. The neutron absorbing material may be attached in the form of a plate to the fuel assembly forward tie plate, or may be inserted as a pellet into the front end of the tubular cladding. (Owens, K.J.)

  15. Liaison based assembly design

    Energy Technology Data Exchange (ETDEWEB)

    Ames, A.; Kholwadwala, D.; Wilson, R.H.

    1996-12-01

    Liaison Based Assembly Design extends the current information infrastructure to support design in terms of kinematic relationships between parts, or liaisons. These liaisons capture information regarding contact, degrees-of-freedom constraints and containment relationships between parts in an assembly. The project involved defining a useful collection of liaison representations, investigating their properties, and providing for maximum use of the data in downstream applications. We tested our ideas by implementing a prototype system involving extensions to Pro/Engineer and the Archimedes assembly planner. With an expanded product model, the design system is more able to capture design intent. When a product update is attempted, increased knowledge availability improves our ability to understand the effect of design changes. Manufacturing and analysis disciplines benefit from having liaison information available, so less time is wasted arguing over incomplete design specifications and our enterprise can be more completely integrated.

  16. Integrated magnetic transformer assembly

    DEFF Research Database (Denmark)

    2014-01-01

    The present invention relates to an integrated magnetics transformer assembly comprising a first magnetically permeable core forming a first substantially closed magnetic flux path and a second magnetically permeable core forming a second substantially closed magnetic flux path. A first input...... inductor winding is wound around a first predetermined segment of the first magnetically permeable core and a second input inductor winding is wound around a first predetermined segment of the second magnetically permeable core. The integrated magnetics transformer assembly further comprises a first output......-winding of the first output inductor winding and the first half-winding of the second output inductor winding are configured to produce aligned, i.e. in the same direction, magnetic fluxes through the first substantially closed magnetic flux path. The integrated magnetics transformer assembly is well- suited for use...

  17. 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

  18. OPEC future capacity expansions

    International Nuclear Information System (INIS)

    Sandrea, I.

    2005-01-01

    This conference presentation examined OPEC future capacity expansions including highlights from 2000-2004 from the supply perspective and actions by OPEC; OPEC spare capacity in 2005/2006; medium-term capacity expansion and investments; long-term scenarios, challenges and opportunities; and upstream policies in member countries. Highlights from the supply perspective included worst than expected non-OPEC supply response; non-OPEC supply affected by a number of accidents and strikes; geopolitical tensions; and higher than expected demand for OPEC crude. OPEC's actions included closer relationship with other producers and consumers; capacity expansions in 2004 and 2005/2006; and OPEC kept the market well supplied with crude in 2004. The presentation also provided data using graphical charts on OPEC net capacity additions until 2005/2006; OPEC production versus spare capacity from 2003 to 2005; OPEC production and capacity to 2010; and change in required OPEC production from 2005-2020. Medium term expansion to 2010 includes over 60 projects. Medium-term risks such as project execution, financing, costs, demand, reserves, depletion, integration of Iraq, and geopolitical tensions were also discussed. The presentation concluded that in the long term, large uncertainties remain; the peak of world supply is not imminent; and continued and enhanced cooperation is essential to market stability. tabs., figs

  19. Preparation and Optimization OF Palm-Based Lipid Nanoparticles Loaded with Griseofulvin.

    Science.gov (United States)

    Huei Lim, Wen; Jean Tan, Yann; Sin Lee, Choy; Meng Er, Hui; Fung Wong, Shew

    2017-01-01

    Palm-based lipid nanoparticle formulation loaded with griseofulvin was prepared by solvent-free hot homogenization method. The griseofulvin loaded lipid nanoparticles were prepared via stages of optimisation, by altering the high pressure homogenisation (HPH) parameters, screening on palm-based lipids and Tween series surfactants and selection of lipid to surfactant ratios. A HPLC method has been validated for the drug loading capacity study. The optimum HPH parameter was determined to be 1500 bar with 5 cycles and among the palm-based lipid materials; Lipid C (triglycerides) was selected for the preparation of lipid nanoparticles. Tween 80 was chosen from the Tween series surfactants for its highest saturated solubility of griseofulvin at 53.1 ± 2.16 µg/mL. The optimum formulation of the griseofulvin loaded lipid nanoparticles demonstrated nano-range of particle size (179.8 nm) with intermediate distribution index (PDI) of 0.306, zeta potential of -27.9 mV and drug loading of 0.77%. The formulation was stable upon storage for 1 month at room temperature (25 ° C) and 45 ° C with consistent drug loading capacity.

  20. Transfer of fuel assemblies

    International Nuclear Information System (INIS)

    Vuckovich, M.; Burkett, J. P.; Sallustio, J.

    1984-01-01

    Fuel assemblies of a nuclear reactor are transferred during fueling or refueling or the like by a crane. The work-engaging fixture of the crane picks up an assembly, removes it from this slot, transfers it to the deposit site and deposits it in its slot at the deposit site. The control for the crane includes a strain gauge connected to the crane line which raises and lowers the load. The strain gauge senses the load on the crane. The signal from the strain gauge is compared with setpoints; a high-level setpoint, a low-level setpoint and a slack-line setpoint. If the strain gauge signal exceeds the high-level setpoint, the line drive is disabled. This event may occur during raising of a fuel assembly which encounters resistance. The high-level setpoint may be overridden under proper precautions. The line drive is also disabled if the strain gauge signal is less than the low-level setpoint. This event occurs when a fuel assembly being deposited contacts the bottom of its slot or an obstruction in, or at the entry to the slot. To preclude lateral movement and possible damage to a fuel assembly suspended from the crane line, the traverse drive of the crane is disabled once the strain-gauge exceets the lov-level setpoint. The traverse drive can only be enabled after the strain-gauge signal is less than the slack-line set-point. This occurs when the lines has been set in slack-line setting. When the line is tensioned after slack-li ne setting, the traverse drive remains enabled only if the line has been disconnected from the fuel assembly

  1. [Lipid and metabolic profiles in adolescents are affected more by physical fitness than physical activity (AVENA study)].

    Science.gov (United States)

    García-Artero, Enrique; Ortega, Francisco B; Ruiz, Jonatan R; Mesa, José L; Delgado, Manuel; González-Gross, Marcela; García-Fuentes, Miguel; Vicente-Rodríguez, Germán; Gutiérrez, Angel; Castillo, Manuel J

    2007-06-01

    To determine whether the level of physical activity or physical fitness (i.e., aerobic capacity and muscle strength) in Spanish adolescents influences lipid and metabolic profiles. From a total of 2859 Spanish adolescents (age 13.0-18.5 years) taking part in the AVENA (Alimentación y Valoración del Estado Nutricional en Adolescentes) study, 460 (248 male, 212 female) were randomly selected for blood analysis. Their level of physical activity was determined by questionnaire. Aerobic capacity was assessed using the Course-Navette test. Muscle strength was evaluated using manual dynamometry, the long jump test, and the flexed arm hang test. A lipid-metabolic cardiovascular risk index was derived from the levels of triglycerides, low-density lipoprotein cholesterol (LDLC), high-density lipoprotein cholesterol (HDLC), and glucose. No relationship was found between the level of physical activity and lipid-metabolic index in either sex. In contrast, there was an inverse relationship between the lipid-metabolic index and aerobic capacity in males (P=.003) after adjustment for physical activity level and muscle strength. In females, a favorable lipid-metabolic index was associated with greater muscle strength (P=.048) after adjustment for aerobic capacity. These results indicate that, in adolescents, physical fitness, and not physical activity, is related to lipid and metabolic cardiovascular risk. Higher aerobic capacity in males and greater muscle strength in females were associated with lower lipid and metabolic risk factors for cardiovascular disease.

  2. Neutron detector assembly

    International Nuclear Information System (INIS)

    Hanai, Koi; Shirayama, Shinpei.

    1978-01-01

    Purpose: To prevent gamma-ray from leaking externally passing through the inside of a neutron detector assembly. Constitution: In a neutron detector assembly having a protection pipe formed with an enlarged diameter portion which serves also as a spacer, partition plates with predetermined width are disposed at the upper and the lower portions in this expanded portion. A lot of metal particles are filled into spaces formed by the partition plates. In such a structure, the metal particles well-absorb the gamma-rays from above and convert them into heat to provide shielding for the gamma-rays. (Horiuchi, T.)

  3. Assembling RNA Nanoparticles.

    Science.gov (United States)

    Xiao, Shou-Jun

    2017-01-01

    RNA nanoparticles are designed and self-assembled according to noncanonical interactions of naturally conserved RNA motifs and/or canonical Watson-Crick base-pairing interactions, which have potential applications in gene therapy and nanomedicine. These artificially engineered nanoparticles are mainly synthesized from in vitro transcribed RNAs, purified by denaturing and native polyacrylamide gel electrophoresis (PAGE), and characterized with native PAGE, AFM, and TEM technologies. The protocols of in vitro transcription, denaturing and native PAGE, and RNA nanoparticle self-assembly are described in detail.

  4. Assembling an aesthetic.

    Science.gov (United States)

    Candela, Emily

    2012-12-01

    Recent research informing and related to the study of three-dimensional scientific models is assembled here in a way that explores an aesthetic, specifically, of touch. I concentrate on the materiality of models, drawing on insights from the history and philosophy of science, design and metaphysics. This article chronicles the ways in which touch, or material interactions, operate in the world of 3D models, and its role in what models mean and do. I end with a call for greater attention to scientific process, described as assembly of and within science, which is revealed by this focus on touch. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Nuclear fuel assembly

    International Nuclear Information System (INIS)

    1975-01-01

    The nuclear fuel assembly described includes a cluster of fuel elements supported at a distance from each other so that their axes are parallel in order to establish secondary channels between them reserved for the coolant. Several ducts for an auxiliary cooling fluid are arranged in the cluster. The wall of each duct is pierced with coolant ejection holes which are placed circumferentially to a pre-determined pattern established according to the position of the duct in the cluster and by the axial distance of the ejection hole along the duct. This assembly is intended for reactors cooled by light or heavy water [fr

  6. Vedr.: Military capacity building

    DEFF Research Database (Denmark)

    Larsen, Josefine Kühnel; Struwe, Lars Bangert

    2013-01-01

    Military capacity building has increasingly become an integral part of Danish defence. Military capacity is a new way of thinking Danish defence and poses a new set of challenges and opportunities for the Danish military and the Political leadership. On the 12th of december, PhD. Candidate Josefine...... Kühnel Larsen and researcher Lars Bangert Struwe of CMS had organized a seminar in collaboration with Royal Danish Defense Colleg and the East African Security Governance Network. The seminar focused on some of the risks involved in Military capacity building and how these risks are dealt with from...

  7. 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.

  8. 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.

  9. 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…

  10. 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....

  11. 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

  12. Capacity Alignment ANADP

    OpenAIRE

    Davidson, Joy; Whitehead, Martha; Molloy, Laura; Molinaro, Mary

    2014-01-01

    Aligning National Approaches to Digital Preservation: An Action Assembly Biblioteca de Catalunya (National Library of Catalonia) November 18-20, 2013, Barcelona, Spain Auburn University Council on Library and Information Resources (CLIR) Digital Curation Centre (DCC) Digital Preservation Network (DPN) Joint Information Systems Committee (JISC) University of North Texas Virginia Tech Interuniversity Consortium for Political and Social Research (ICPSR) Innovative Inte...

  13. Comprehensive Lipidome-Wide Profiling Reveals Dynamic Changes of Tea Lipids during Manufacturing Process of Black Tea.

    Science.gov (United States)

    Li, Jia; Hua, Jinjie; Zhou, Qinghua; Dong, Chunwang; Wang, Jinjin; Deng, Yuliang; Yuan, Haibo; Jiang, Yongwen

    2017-11-22

    As important biomolecules in Camellia sinensis L., lipids undergo substantial changes during black tea manufacture, which is considered to contribute to tea sensory quality. However, limited by analytical capacity, detailed lipid composition and its dynamic changes during black tea manufacture remain unclear. Herein, we performed tea lipidome profiling using high resolution liquid chromatography coupled to mass spectrometry (LC-MS), which allows simultaneous and robust analysis of 192 individual lipid species in black tea, covering 17 (sub)classes. Furthermore, dynamic changes of tea lipids during black tea manufacture were investigated. Significant alterations of lipid pattern were revealed, involved with chlorophyll degradation, metabolic pathways of glycoglycerolipids, and other extraplastidial membrane lipids. To our knowledge, this report presented most comprehensive coverage of lipid species in black tea. This study provides a global and in-depth metabolic map of tea lipidome during black tea manufacture.

  14. Capacity analysis of an automated kit transportation system

    NARCIS (Netherlands)

    Zijm, W.H.M.; Adan, I.J.B.F.; Buitenhek, R.; Houtum, van G.J.J.A.N.

    2000-01-01

    In this paper, we present a capacity analysis of an automated transportation system in a flexible assembly factory. The transportation system, together with the workstations, is modeled as a network of queues with multiple job classes. Due to its complex nature, the steadystate behavior of this

  15. Measurement of the specific heat capacity of graphite

    Energy Technology Data Exchange (ETDEWEB)

    Picard, S.; Burns, D.T.; Roger, P

    2006-01-15

    With the objective of implementing graphite calorimetry at the BIPM to measure absorbed dose, an experimental assembly has recently been constructed to measure the specific heat capacity of graphite. A status description of the apparatus and results from the first measurements are given. The outcome is discussed and the experimental uncertainty is reviewed. (authors)

  16. Measurement of the specific heat capacity of graphite

    International Nuclear Information System (INIS)

    Picard, S.; Burns, D.T.; Roger, P.

    2006-01-01

    With the objective of implementing graphite calorimetry at the BIPM to measure absorbed dose, an experimental assembly has recently been constructed to measure the specific heat capacity of graphite. A status description of the apparatus and results from the first measurements are given. The outcome is discussed and the experimental uncertainty is reviewed. (authors)

  17. 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.

  18. Antihypertensive neutral lipid

    Science.gov (United States)

    Snyder, F.L.; Blank, M.L.

    1984-10-26

    The invention relates to the discovery of a class of neutral acetylated either-linked glycerolipids having the capacity to lower blood presure in warm-blooded animals. This physiological effect is structure sensitive requiring a long chain alkyl group at the sn-1 position and a short carbon chain acyl group (acetyl or propionyl) at the sn-2 position, and a hydroxyl group at the sn-3 position.

  19. Fire resistant PV shingle assembly

    Science.gov (United States)

    Lenox, Carl J.

    2012-10-02

    A fire resistant PV shingle assembly includes a PV assembly, including PV body, a fire shield and a connection member connecting the fire shield below the PV body, and a support and inter-engagement assembly. The support and inter-engagement assembly is mounted to the PV assembly and comprises a vertical support element, supporting the PV assembly above a support surface, an upper interlock element, positioned towards the upper PV edge, and a lower interlock element, positioned towards the lower PV edge. The upper interlock element of one PV shingle assembly is inter-engageable with the lower interlock element of an adjacent PV shingle assembly. In some embodiments the PV shingle assembly may comprise a ventilation path below the PV body. The PV body may be slidably mounted to the connection member to facilitate removal of the PV body.

  20. Evaluating Capacity Development

    International Development Research Centre (IDRC) Digital Library (Canada)

    She also had the dubious pleasure of checking and correcting the text numerous ... Has your organization received training or other types of support for capacity ...... processors, and consumer groups in its research and development work.

  1. 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.

  2. Revisiting Absorptive Capacity

    DEFF Research Database (Denmark)

    de Araújo, Ana Luiza Lara; Ulhøi, John Parm; Lettl, Christopher

    Absorptive capacity has mostly been perceived as a 'passive' outcome of R&D investments. Recently, however, a growing interest into its 'proactive' potentials has emerged. This paper taps into this development and proposes a dynamic model for conceptualizing the determinants of the complementary...... learning processes of absorptive capacity, which comprise combinative and adaptive capabilities. Drawing on survey data (n=169), the study concludes that combinative capabilities primarily enhance transformative and exploratory learning processes, while adaptive capabilities strengthen all three learning...

  3. Turbomachine blade assembly

    Science.gov (United States)

    Garcia Crespo, Andres Jose

    2016-11-01

    Embodiments of the present disclosure include a system comprising a turbomachine blade assembly having a blade portion, a shank portion, and a mounting portion, wherein the blade portion, the shank portion, and the mounting portion comprise a first plurality of plies extending from a tip of the airfoil to a base of the dovetail.

  4. Fuel sub-assembly

    International Nuclear Information System (INIS)

    Jolly, R.

    1982-01-01

    A fuel sub-assembly for a liquid metal cooled nuclear reactor is described in which the bundle of fuel pins are braced apart by a series of spaced grids. The grids at the lower end are capable of yielding, thus allowing pins swollen by irradiation to be withdrawn with a reduced risk of damage. (U.K.)

  5. Nanoparticle assemblies and superstructures

    National Research Council Canada - National Science Library

    Kotov, Nicholas A

    2006-01-01

    ... building blocks of larger and more complex systems. Therefore, the present challenge of nanoscale science is to shift from making certain building blocks to organizing them in one-, two-, and three-dimensional structures. Such assemblies and superstructures are the next logical step in the development of nanoscience and nanotechnology. In this re...

  6. Spool assembly support analysis

    International Nuclear Information System (INIS)

    Norman, B.F.

    1994-01-01

    This document provides the wind/seismic analysis and evaluation for the pump pit spool assemblies. Hand calculations were used for the analysis. UBC, AISC, and load factors were used in this evaluation. The results show that the actual loads are under the allowable loads and all requirements are met

  7. Nanotechnology: A molecular assembler

    Science.gov (United States)

    Kelly, T. Ross; Snapper, Marc L.

    2017-09-01

    The idea of nanometre-scale machines that can assemble molecules has long been thought of as the stuff of science fiction. Such a machine has now been built -- and might herald a new model for organic synthesis. See Letter p.374

  8. Macroscopic magnetic Self assembly

    NARCIS (Netherlands)

    Löthman, Per Arvid

    2018-01-01

    Exploring the macroscopic scale's similarities to the microscale is part and parcel of this thesis as reflected in the research question: what can we learn about the microscopic scale by studying the macroscale? Investigations of the environment in which the self-assembly takes place, and the

  9. Assembling Sustainable Territories

    DEFF Research Database (Denmark)

    Vandergeest, Peter; Ponte, Stefano; Bush, Simon

    2015-01-01

    that territorialisation is accomplished not just through (re)defining bounded space, but more broadly through the assembling of four elements: space, subjects, objects, and expertise. Four case studies of sustainability certification in seafood are analyzed to show that ‘green gabbing’ is not necessarily the central...

  10. Assembling sustainable territories

    NARCIS (Netherlands)

    Vandergeest, Peter; Ponte, Stefano; Bush, Simon

    2015-01-01

    The authors show how certification assembles ‘sustainable’ territories through a complex layering of regulatory authority in which both government and nongovernment entities claim rule-making authority, sometimes working together, sometimes in parallel, sometimes competitively. It is argued that

  11. Turneri preemia 2015: Assemble

    Index Scriptorium Estoniae

    2015-01-01

    Turneri 2015. aasta preemia pälvis radikaalne noorte arhitektide kollektiiv Assemble. Rühmitus on 18-liikmeline ja baseerub Ida-Londonis ning selle tegevust võib üldistatult nimetada hüljatud ruumide taaselustamiseks kogukondlike aktsioonide kaudu

  12. Industrial Assembly Cases

    DEFF Research Database (Denmark)

    Ellekilde, Lars-Peter; Buch, Jacob Pørksen; Iversen, Thorbjørn Mosekjær

    This technical report presents 13 different industrial assembly tasks, which are composed of 70 different operations. The report is written to provide an overview and do as such not contain product specific information such as object weights, dimensions etc. The operations are classified into a set...

  13. Biosynthesis: Reprogramming assembly lines

    Science.gov (United States)

    Menon, Binuraj R. K.; Jenner, Matthew

    2018-03-01

    Rational engineering of biosynthetic assembly lines for production of new compounds is an attractive prospect, yet it presents many challenges. Learning from biology, some of the rules for expanding the chemical diversity of non-ribosomal peptides have been uncovered in two recent studies.

  14. Ordinary General Assembly

    CERN Multimedia

    Staff Association

    2011-01-01

    Tuesday 12 April at 14.00 Council Chamber, Bldg 503 In conformity with the Statutes of the Staff Association, an ordinary General Assembly is organized once a year (article IV.2.1). Agenda   Adoption of the Agenda Approval of the Draft Minutes of the Ordinary General Assembly of 20 April 2010 Presentation and approval of the Activity Report 2010 Presentation and approval of the Financial Report 2010 Presentation and approval of the Auditors Report 2010 Programme for 2011 Presentation et and approval of the draft budget and subscription rate 2012 Election of the Election Committee Election of the Board of Auditors Miscellaneous We remind members of article IV.3.4 in the Statutes of the Association which reads: “After having dealt with all the items on the agenda, the members may, with the consent of the Assembly, have other matters discussed, but decisions may be taken only on the items listed on the agenda. Nevertheless, the Assembly ma...

  15. Ordinary General Assembly

    CERN Multimedia

    Staff Association

    2011-01-01

    Tuesday 12 April at 14.00 Council Chamber, Bldg 503 In conformity with the Statutes of the Staff Association, an ordinary General Assembly is organized once a year (article IV.2.1). Agenda   Adoption of the Agenda Approval of the Draft Minutes of the Ordinary General Assembly of 20 April 2010 Presentation and approval of the Activity Report 2010 Presentation and approval of the Financial Report 2010 Presentation and approval of the Auditors Report 2010 Programme for 2011 Presentation and approval of the draft budget and subscription rate 2012 Election of the Election Committee Election of the Board of Auditors Miscellaneous We remind members of article IV.3.4 in the Statutes of the Association which reads: “After having dealt with all the items on the agenda, the members may, with the consent of the Assembly, have other matters discussed, but decisions may be taken only on the items listed on the agenda. Nevertheless, the Assembly may r...

  16. Ordinary General Assembly

    CERN Multimedia

    Staff Association

    2010-01-01

    Tuesday 20 April at 10.00 Council Chamber, Bldg 503 In conformity with the Statutes of the Staff Association, an ordinary General Assembly is organized once a year (article IV.2.1). Agenda   Adoption of the Agenda Approval of the Draft Minutes of the Ordinary General Assembly of 12 May 2009 Presentation and approval of the Activity Report 2009 Presentation and approval of the Financial Report 2009 Presentation and approval of the Auditors Report 2009 Programme for 2010 Presentation et and approval of the draft budget and subscription rate 2010 Election of the Election Committee Election of the Board of Auditors Miscellaneous We remind members of article IV.3.4 in the Statutes of the Association which reads: “After having dealt with all the items on the agenda, the members may, with the consent of the Assembly, have other matters discussed, but decisions may be taken only on the items listed on the agenda. Nevertheless, the Assembly may require t...

  17. Lageos assembly operation plan

    Science.gov (United States)

    Brueger, J.

    1975-01-01

    Guidelines and constraints procedures for LAGEOS assembly, operation, and design performance are given. Special attention was given to thermal, optical, and dynamic analysis and testing. The operation procedures illustrate the interrelation and sequence of tasks in a flow diagram. The diagram also includes quality assurance functions for verification of operation tasks.

  18. Assembly of primary cilia

    DEFF Research Database (Denmark)

    Pedersen, Lotte B; Veland, Iben R; Schrøder, Jacob M

    2008-01-01

    knowledge about IFT is based on studies performed in Chlamydomonas and Caenorhabditis elegans. Therefore, our review of the IFT literature includes studies performed in these two model organisms. The role of several non-IFT proteins (e.g., centrosomal proteins) in the ciliary assembly process is also...... discussed. Developmental Dynamics, 2008. (c) 2008 Wiley-Liss, Inc....

  19. Cationic membranes complexed with oppositely charged microtubules: hierarchical self-assembly leading to bio-nanotubes

    International Nuclear Information System (INIS)

    Raviv, Uri; Needleman, Daniel J; Safinya, Cyrus R

    2006-01-01

    The self-assembly of microtubules and charged membranes has been studied, using x-ray diffraction and electron microscopy. Polyelectrolyte lipid complexes usually form structures templated by the lipid phase, when the polyelectrolyte curvature is much larger than the membrane spontaneous curvature. When the polyelectrolyte curvature approaches the membrane spontaneous curvature, as in microtubules, two types of new structures emerge. Depending on the conditions, vesicles either adsorb onto the microtubule, forming a 'beads on a rod' structure, or coat the microtubule, which now forms the template. Tubulin oligomers then coat the external lipid layer, forming a lipid protein nanotube. The tubulin oligomer coverage at the external layer is determined by the membrane charge density. The energy barrier between the beads on a rod and the lipid-protein nanotube states depends on the membrane bending rigidity and membrane charge density. By controlling the lipid/tubulin stoichiometry we can switch between lipid-protein nanotubes with open ends to lipid-protein nanotubes with closed end with lipid cups. This forms the basis for controlled drug encapsulation and release

  20. Rapid induction of lipid droplets in Chlamydomonas reinhardtii and Chlorella vulgaris by Brefeldin A.

    Directory of Open Access Journals (Sweden)

    Sangwoo Kim

    Full Text Available Algal lipids are the focus of intensive research because they are potential sources of biodiesel. However, most algae produce neutral lipids only under stress conditions. Here, we report that treatment with Brefeldin A (BFA, a chemical inducer of ER stress, rapidly triggers lipid droplet (LD formation in two different microalgal species, Chlamydomonas reinhardtii and Chlorella vulgaris. LD staining using Nile red revealed that BFA-treated algal cells exhibited many more fluorescent bodies than control cells. Lipid analyses based on thin layer chromatography and gas chromatography revealed that the additional lipids formed upon BFA treatment were mainly triacylglycerols (TAGs. The increase in TAG accumulation was accompanied by a decrease in the betaine lipid diacylglyceryl N,N,N-trimethylhomoserine (DGTS, a major component of the extraplastidic membrane lipids in Chlamydomonas, suggesting that at least some of the TAGs were assembled from the degradation products of membrane lipids. Interestingly, BFA induced TAG accumulation in the Chlamydomonas cells regardless of the presence or absence of an acetate or nitrogen source in the medium. This effect of BFA in Chlamydomonas cells seems to be due to BFA-induced ER stress, as supported by the induction of three homologs of ER stress marker genes by the drug. Together, these results suggest that ER stress rapidly triggers TAG accumulation in two green microalgae, C. reinhardtii and C. vulgaris. A further investigation of the link between ER stress and TAG synthesis may yield an efficient means of producing biofuel from algae.

  1. Effect of Amphotericin B antibiotic on the properties of model lipid membrane

    International Nuclear Information System (INIS)

    Kiryakova, S; Dencheva-Zarkova, M; Genova, J

    2014-01-01

    Model membranes formed from natural and synthetic lipids are an interesting object for scientific investigations due to their similarity to biological cell membrane and their simple structure with controlled composition and properties. Amphotericin B is an important polyene antifungal antibiotic, used for treatment of systemic fungal infections. It is known from the literature that the studied antibiotic has a substantial effect on the transmembrane ionic channel structures. When applied to the lipid membranes it has the tendency to create pores and in this way to affect the structure and the properties of the membrane lipid bilayer. In this work the thermally induced shape fluctuations of giant quasi-spherical liposomes have been used to study the influence of polyene antibiotic amphotericin B on the elastic properties of model lipid membranes. It have been shown experimentally that the presence of 3 mol % of AmB in the lipid membrane reduces the bending elasticity of the lipid membrane for both studied cases: pure SOPC membrane and mixed SOPC-Cholesterol membrane. Interaction of the amphotericin B with bilayer lipid membranes containing channels have been studied in this work. Model membranes were self-assembled using the patch-clamp and tip-dip patch clamp technique. We have found that amphotericin B is an ionophore and reduces the resistance of the lipid bilayer

  2. Multi-Stacked Supported Lipid Bilayer Micropatterning through Polymer Stencil Lift-Off

    Directory of Open Access Journals (Sweden)

    Yujie Zhu

    2015-08-01

    Full Text Available Complex multi-lamellar structures play a critical role in biological systems, where they are present as lamellar bodies, and as part of biological assemblies that control energy transduction processes. Multi-lamellar lipid layers not only provide interesting systems for fundamental research on membrane structure and bilayer-associated polypeptides, but can also serve as components in bioinspired materials or devices. Although the ability to pattern stacked lipid bilayers at the micron scale is of importance for these purposes, limited work has been done in developing such patterning techniques. Here, we present a simple and direct approach to pattern stacked supported lipid bilayers (SLBs using polymer stencil lift-off and the electrostatic interactions between cationic and anionic lipids. Both homogeneous and phase-segregated stacked SLB patterns were produced, demonstrating that the stacked lipid bilayers retain lateral diffusivity. We demonstrate patterned SLB stacks of up to four bilayers, where fluorescence resonance energy transfer (FRET and quenching was used to probe the interactions between lipid bilayers. Furthermore, the study of lipid phase behaviour showed that gel phase domains align between adjacent layers. The proposed stacked SLB pattern platform provides a robust model for studying lipid behaviour with a controlled number of bilayers, and an attractive means towards building functional bioinspired materials or devices.

  3. 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.

  4. 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.

  5. Platform for Lipid Based Nanocarriers' Formulation Components and their Potential Effects: A Literature Review.

    Science.gov (United States)

    Farid, Ragwa Mohamed; Youssef, Nancy Abdel Hamid Abou; Kassem, Abeer Ahmed

    2017-11-27

    Lipid based nanocarriers have gained recently enormous interest for pharmaceutical application. They have the potential to provide controlled drug release and to target the drug to a specific area. In addition, lipid based nanocarriers can improve the bioavailability of drugs suffering from high hepatic first-pass metabolism, by enhancing their transport via the lymphatic system. The main components of lipid based nanocarriers are lipids and surfactants. Both have great influence on the prepared lipid based systems characteristics. The criteria for their selection are much related to physicochemical properties of the drug and the required administration route. This work gives an overview on the effect of both the type and amount of lipids and surfactants used in the manufacture of lipid based nanocarriers on their behavior and characteristics. Recent studies revealed that the properties of the final product including; particle size, homogeneity, drug loading capacity, zeta potential, drug release profile, stability, permeability, pharmacokinetic properties, crystallinity and cytotoxicity, may be significantly influenced not only by the type but also the amount of the lipids and/or surfactants included in the formulation of the lipid based nanocarriers. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  6. Molecular dynamics simulations of stratum corneum lipid mixtures: A multiscale perspective.

    Science.gov (United States)

    Moore, Timothy C; Iacovella, Christopher R; Leonhard, Anne C; Bunge, Annette L; McCabe, Clare

    2018-03-29

    The lipid matrix of the stratum corneum (SC) layer of skin is essential for human survival; it acts as a barrier to prevent rapid dehydration while keeping potentially hazardous material outside the body. While the composition of the SC lipid matrix is known, the molecular-level details of its organization are difficult to infer experimentally, hindering the discovery of structure-property relationships. To this end, molecular dynamics simulations, which give molecular-level resolution, have begun to play an increasingly important role in understanding these relationships. However, most simulation studies of SC lipids have focused on preassembled bilayer configurations, which, owing to the slow dynamics of the lipids, may influence the final structure and hence the calculated properties. Self-assembled structures would avoid this dependence on the initial configuration, however, the size and length scales involved make self-assembly impractical to study with atomistic models. Here, we report on the development of coarse-grained models of SC lipids designed to study self-assembly. Building on previous work, we present the interactions between the headgroups of ceramide and free fatty acid developed using the multistate iterative Boltzmann inversion method. Validation of the new interactions is performed with simulations of preassembled bilayers and good agreement between the atomistic and coarse-grained models is found for structural properties. The self-assembly of mixtures of ceramide and free fatty acid is investigated and both bilayer and multilayer structures are found to form. This work therefore represents a necessary step in studying SC lipid systems on multiple time and length scales. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Phosphoinositides: Tiny Lipids With Giant Impact on Cell Regulation

    Science.gov (United States)

    2013-01-01

    Phosphoinositides (PIs) make up only a small fraction of cellular phospholipids, yet they control almost all aspects of a cell's life and death. These lipids gained tremendous research interest as plasma membrane signaling molecules when discovered in the 1970s and 1980s. Research in the last 15 years has added a wide range of biological processes regulated by PIs, turning these lipids into one of the most universal signaling entities in eukaryotic cells. PIs control organelle biology by regulating vesicular trafficking, but they also modulate lipid distribution and metabolism via their close relationship with lipid transfer proteins. PIs regulate ion channels, pumps, and transporters and control both endocytic and exocytic processes. The nuclear phosphoinositides have grown from being an epiphenomenon to a research area of its own. As expected from such pleiotropic regulators, derangements of phosphoinositide metabolism are responsible for a number of human diseases ranging from rare genetic disorders to the most common ones such as cancer, obesity, and diabetes. Moreover, it is increasingly evident that a number of infectious agents hijack the PI regulatory systems of host cells for their intracellular movements, replication, and assembly. As a result, PI converting enzymes began to be noticed by pharmaceutical companies as potential therapeutic targets. This review is an attempt to give an overview of this enormous research field focusing on major developments in diverse areas of basic science linked to cellular physiology and disease. PMID:23899561

  8. Amyloidogenesis abolished by proline substitutions but enhanced by lipid binding.

    Directory of Open Access Journals (Sweden)

    Ping Jiang

    2009-04-01

    Full Text Available The influence of lipid molecules on the aggregation of a highly amyloidogenic segment of human islet amyloid polypeptide, hIAPP20-29, and the corresponding sequence from rat has been studied by all-atom replica exchange molecular dynamics (REMD simulations with explicit solvent model. hIAPP20-29 fragments aggregate into partially ordered beta-sheet oligomers and then undergo large conformational reorganization and convert into parallel/antiparallel beta-sheet oligomers in mixed in-register and out-of-register patterns. The hydrophobic interaction between lipid tails and residues at positions 23-25 is found to stabilize the ordered beta-sheet structure, indicating a catalysis role of lipid molecules in hIAPP20-29 self-assembly. The rat IAPP variants with three proline residues maintain unstructured micelle-like oligomers, which is consistent with non-amyloidogenic behavior observed in experimental studies. Our study provides the atomic resolution descriptions of the catalytic function of lipid molecules on the aggregation of IAPP peptides.

  9. The development of flow test technology for PWR fuel assembly

    International Nuclear Information System (INIS)

    Chung, Moon Ki; Cha, Chong Hee; Chung, Chang Hwan; Chun, Se Young; Song, Chul Hwa; Chung, Heung Joon; Won, Soon Yeun; Cho, Yeong Rho; Kim, Bok Deuk

    1988-05-01

    KAERI has an extensive program to develope PWR fuel assembly. In relation to the program, development of flow test technology is needed to evaluate the thermal hydraulic compactibility and mechanical integrity of domestically fabricated nuclear fuels. A high-pressure and high-temperature flow test facility was designed to test domestically fabricated fuel assembly. The test section of the facility has capacity of a 6x6 full length PWR fuel assembly. A flow test rig was designed and installed at Cold Test Loop to carry out model experiments with 5x5 rod assembly under atmosphere pressure to get information about the characteristics of pressure loss of spacer grids and velocity distribution in the subchannels. LDV measuring technology was established using TSI's Laser Dopper Velocimeter 9100-3 System

  10. 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...

  11. School Assemblies: The Lost Art.

    Science.gov (United States)

    Beach, Daniel R.

    1979-01-01

    Guidelines and suggestions are offered for successful school assemblies. The school assembly should be a positive event; an occasion for developing unity, group loyalty, and desirable audience habits. (Author/MLF)

  12. Assembling large, complex environmental metagenomes

    Energy Technology Data Exchange (ETDEWEB)

    Howe, A. C. [Michigan State Univ., East Lansing, MI (United States). Microbiology and Molecular Genetics, Plant Soil and Microbial Sciences; Jansson, J. [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Earth Sciences Division; Malfatti, S. A. [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Tringe, S. G. [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Tiedje, J. M. [Michigan State Univ., East Lansing, MI (United States). Microbiology and Molecular Genetics, Plant Soil and Microbial Sciences; Brown, C. T. [Michigan State Univ., East Lansing, MI (United States). Microbiology and Molecular Genetics, Computer Science and Engineering

    2012-12-28

    The large volumes of sequencing data required to sample complex environments deeply pose new challenges to sequence analysis approaches. De novo metagenomic assembly effectively reduces the total amount of data to be analyzed but requires significant computational resources. We apply two pre-assembly filtering approaches, digital normalization and partitioning, to make large metagenome assemblies more computationaly tractable. Using a human gut mock community dataset, we demonstrate that these methods result in assemblies nearly identical to assemblies from unprocessed data. We then assemble two large soil metagenomes from matched Iowa corn and native prairie soils. The predicted functional content and phylogenetic origin of the assembled contigs indicate significant taxonomic differences despite similar function. The assembly strategies presented are generic and can be extended to any metagenome; full source code is freely available under a BSD license.

  13. X-Ray Assembler Data

    Data.gov (United States)

    U.S. Department of Health & Human Services — Federal regulations require that an assembler who installs one or more certified components of a diagnostic x-ray system submit a report of assembly. This database...

  14. Welding facilities for NPP assembling

    International Nuclear Information System (INIS)

    Rojtenberg, S.S.

    1987-01-01

    Recommendations concerning the choice of equipment for welding in pre-assembling work shops, in the enlarging assembling shops and at the assembling site, are given. Advanced production automatic welders and semiautomatic machines, applied during the NPP equipment assembling as well as automatic machines specially produced for welding the main reactor components and pipelines are described. Automatic and semiautomatic machine and manual welding post supply sources are considered

  15. Reflector-moderated critical assemblies

    International Nuclear Information System (INIS)

    Paxton, H.C.; Jarvis, G.A.; Byers, C.C.

    1975-07-01

    Experiments with reflector-moderated critical assemblies were part of the Rover Program at the Los Alamos Scientific Laboratory (LASL). These assemblies were characterized by thick D 2 O or beryllium reflectors surrounding large cavities that contained highly enriched uranium at low average densities. Because interest in this type of system has been revived by LASL Plasma Cavity Assembly studies, more detailed descriptions of the early assemblies than had been available in the unclassified literature are provided. (U.S.)

  16. Most advanced HTP fuel assembly design for EPR

    International Nuclear Information System (INIS)

    Francillon, Eric; Kiehlmann, Horst-Dieter

    2006-01-01

    End 2003, the Finnish electricity utility Teollisuuden Voima Oy (TVO) signed the contract for building an EPR in Olkiluoto (Finland). Mid 2004, the French electricity utility EDF selected an EPR to be built in France. In 2005, Framatome ANP, an AREVA and Siemens company, announced that they will be pursuing a design certification in the U.S. The EPR development is based on the latest PWR product lines of former Framatome (N4) and Siemens Nuklear (Konvoi). As an introductory part, different aspects of the EPR core characteristics connected to fuel assembly design are presented. It includes means of ensuring reactivity control like hybrid AIC/B4C control rod absorbers and gadolinium as burnable absorber integrated in fuel rods, and specific options for in-core instrumentation, such as Aeroball type instrumentation. Then the design requirements for the EPR fuel assembly are presented in term of very high burnup capacity, rod cladding and fuel assembly reliability. Framatome ANP fuel assembly product characteristics meeting these requirements are then described. EPR fuel assembly design characteristics benefit from the experience feedback of the latest fuel assembly products designed within Framatome ANP, leading to resistance to assembly deformation, high fuel rod restraint and prevention of handling hazards. EPR fuel assembly design features the best components composing the cornerstones of the upgraded family of fuel assemblies that FRAMATOME ANP proposes today. This family is based on a set of common characteristics and associated features, which include the HMP grid as bottom end spacer, the MONOBLOC guide tube and the Robust FUELGUARD as lower tie plate, the use of the M5 Alloy, as cladding and structure material. This fully re-crystallized, ternary Zr-Nb-O alloy produces radically improved in-reactor corrosion, very low hydrogen uptake and growth and an excellent creep behavior, which are described there. EPR fuel assembly description also includes fuel rod

  17. Spatio-temporal Dynamics and Mechanisms of Stress Granule Assembly.

    Directory of Open Access Journals (Sweden)

    Daisuke Ohshima

    2015-06-01

    Full Text Available Stress granules (SGs are non-membranous cytoplasmic aggregates of mRNAs and related proteins, assembled in response to environmental stresses such as heat shock, hypoxia, endoplasmic reticulum (ER stress, chemicals (e.g. arsenite, and viral infections. SGs are hypothesized as a loci of mRNA triage and/or maintenance of proper translation capacity ratio to the pool of mRNAs. In brain ischemia, hippocampal CA3 neurons, which are resilient to ischemia, assemble SGs. In contrast, CA1 neurons, which are vulnerable to ischemia, do not assemble SGs. These results suggest a critical role SG plays in regards to cell fate decisions. Thus SG assembly along with its dynamics should determine the cell fate. However, the process that exactly determines the SG assembly dynamics is largely unknown. In this paper, analyses of experimental data and computer simulations were used to approach this problem. SGs were assembled as a result of applying arsenite to HeLa cells. The number of SGs increased after a short latent period, reached a maximum, then decreased during the application of arsenite. At the same time, the size of SGs grew larger and became localized at the perinuclear region. A minimal mathematical model was constructed, and stochastic simulations were run to test the modeling. Since SGs are discrete entities as there are only several tens of them in a cell, commonly used deterministic simulations could not be employed. The stochastic simulations replicated observed dynamics of SG assembly. In addition, these stochastic simulations predicted a gamma distribution relative to the size of SGs. This same distribution was also found in our experimental data suggesting the existence of multiple fusion steps in the SG assembly. Furthermore, we found that the initial steps in the SG assembly process and microtubules were critical to the dynamics. Thus our experiments and stochastic simulations presented a possible mechanism regulating SG assembly.

  18. High capacity getter pump for UHV operation

    International Nuclear Information System (INIS)

    Manini, P.; Marino, M.; Belloni, F.; Porro, M.

    1993-01-01

    UHV pumps based on non-evaporable getter coated strips find widespread use in particle accelerators, synchrotron radiation machines and nuclear fusion experimental devices. Depending on the geometric constraints, pressure operation conditions and the foreseen gas loads, optimized getter structures, such as modules and cartridges, can be designed and assembled into a high-efficiency pump. In the present paper, the design and performance of a newly conceived High Capacity Getter Pump (HCGP) based on sintered getter bodies, in the shape of blades instead of strips, is illustrated. The porosity and the specific surface area of the blades and their arrangement in the cartridge have been optimized to significantly increase sorption capacity at a given speed. These pumps are well suited for those applications where a very high gas load is expected during the machine operation. The sintered getter bodies increase surface area and capacity, requiring less frequent reactivation and facilitating greater overall life of the pump. A discussion of the experimental results in terms of sorption speed and capacity for various gases is presented

  19. Capacity Maximizing Constellations

    Science.gov (United States)

    Barsoum, Maged; Jones, Christopher

    2010-01-01

    Some non-traditional signal constellations have been proposed for transmission of data over the Additive White Gaussian Noise (AWGN) channel using such channel-capacity-approaching codes as low-density parity-check (LDPC) or turbo codes. Computational simulations have shown performance gains of more than 1 dB over traditional constellations. These gains could be translated to bandwidth- efficient communications, variously, over longer distances, using less power, or using smaller antennas. The proposed constellations have been used in a bit-interleaved coded modulation system employing state-ofthe-art LDPC codes. In computational simulations, these constellations were shown to afford performance gains over traditional constellations as predicted by the gap between the parallel decoding capacity of the constellations and the Gaussian capacity

  20. Dual capacity reciprocating compressor

    Science.gov (United States)

    Wolfe, Robert W.

    1984-01-01

    A multi-cylinder compressor 10 particularly useful in connection with northern climate heat pumps and in which different capacities are available in accordance with reversing motor 16 rotation is provided with an eccentric cam 38 on a crank pin 34 under a fraction of the connecting rods, and arranged for rotation upon the crank pin between opposite positions 180.degree. apart so that with cam rotation on the crank pin such that the crank throw is at its normal maximum value all pistons pump at full capacity, and with rotation of the crank shaft in the opposite direction the cam moves to a circumferential position on the crank pin such that the overall crank throw is zero. Pistons 24 whose connecting rods 30 ride on a crank pin 36 without a cam pump their normal rate with either crank rotational direction. Thus a small clearance volume is provided for any piston that moves when in either capacity mode of operation.

  1. Visual attention capacity

    DEFF Research Database (Denmark)

    Habekost, Thomas; Starrfelt, Randi

    2009-01-01

    Psychophysical studies have identified two distinct limitations of visual attention capacity: processing speed and apprehension span. Using a simple test, these cognitive factors can be analyzed by Bundesen's Theory of Visual Attention (TVA). The method has strong specificity and sensitivity......, and measurements are highly reliable. As the method is theoretically founded, it also has high validity. TVA-based assessment has recently been used to investigate a broad range of neuropsychological and neurological conditions. We present the method, including the experimental paradigm and practical guidelines...... to patient testing, and review existing TVA-based patient studies organized by lesion anatomy. Lesions in three anatomical regions affect visual capacity: The parietal lobes, frontal cortex and basal ganglia, and extrastriate cortex. Visual capacity thus depends on large, bilaterally distributed anatomical...

  2. Nuclear fuel assembly

    International Nuclear Information System (INIS)

    Takeda, Tadashi; Sato, Kenji; Goto, Masakazu.

    1984-01-01

    Purpose: To facilitate identification of a fuel assembly upon fuel exchange in BWR type reactors. Constitution: Fluorescent material is coated or metal plating is applied to the impressed portion of a upper tie plate handle of a fuel assembly, and the fluorescent material or the metal plating surface is covered with a protective membrane made of transparent material. This enables to distinguish the impressed surface from a distant place and chemical reaction between the impressed surface and the reactor water can be prevented. Furthermore, since the protective membrane is formed such that it protrudes toward the upper side relative to the impressed surface, there is no risk of depositions of claddings thereover. (Moriyama, K.)

  3. Fuel nozzle assembly

    Science.gov (United States)

    Johnson, Thomas Edward [Greer, SC; Ziminsky, Willy Steve [Simpsonville, SC; Lacey, Benjamin Paul [Greer, SC; York, William David [Greer, SC; Stevenson, Christian Xavier [Inman, SC

    2011-08-30

    A fuel nozzle assembly is provided. The assembly includes an outer nozzle body having a first end and a second end and at least one inner nozzle tube having a first end and a second end. One of the nozzle body or nozzle tube includes a fuel plenum and a fuel passage extending therefrom, while the other of the nozzle body or nozzle tube includes a fuel injection hole slidably aligned with the fuel passage to form a fuel flow path therebetween at an interface between the body and the tube. The nozzle body and the nozzle tube are fixed against relative movement at the first ends of the nozzle body and nozzle tube, enabling the fuel flow path to close at the interface due to thermal growth after a flame enters the nozzle tube.

  4. Nuclear fuel assembly

    International Nuclear Information System (INIS)

    Ito, Arata; Wakamatsu, Mitsuo.

    1976-01-01

    Object: To permit the coolant in an FBR type reactor to enter from the entrance nozzle into a nuclear fuel assembly without causing cavitation. Structure: In a nuclear fuel assembly, which comprises a number of thin fuel pines bundled together at a uniform spacing and enclosed within an outer cylinder, with a handling head connected to an upper portion of the outer cylinder and an entrance nozzle connected to a lower portion of the cylinder, the inner surface of the entrance nozzle is provided with a buffer member and an orifice successively in the direction of flow of the coolant. The coolant entering from a low pressure coolant chamber into the entrance nozzle strikes the buffer member and is attenuated, and thereafter flows through an orifice into the outer cylinder. (Horiuchi, T.)

  5. Molten core retention assembly

    International Nuclear Information System (INIS)

    Lampe, R.F.

    1976-01-01

    Molten fuel produced in a core overheating accident is caught by a molten core retention assembly consisting of a horizontal baffle plate having a plurality of openings therein, heat exchange tubes having flow holes near the top thereof mounted in the openings, and a cylindrical imperforate baffle attached to the plate and surrounding the tubes. The baffle assembly is supported from the core support plate of the reactor by a plurality of hanger rods which are welded to radial beams passing under the baffle plate and intermittently welded thereto. Preferably the upper end of the cylindrical baffle terminates in an outwardly facing lip to which are welded a plurality of bearings having slots therein adapted to accept the hanger rods

  6. Nuclear fuel assemblies

    International Nuclear Information System (INIS)

    Butterfield, R.S.; Garner, D.L.M.

    1977-01-01

    Reference is made to nuclear fuel assemblies designed for cooling on the 'tube-in-shell' principle in which the fuel is contained by a shell and is cooled by coolant passed through tubes extending through the shell. It has been proposed to employ coated particle fuel as a porous bed on the tube side and the bleed coolant from the tubes into direct contact with the fuel particles. In this way heat is extracted both by direct contact with the fuel and by heat transfer through the coolant tube walls. The system described aims to provide an improved structure of tube and shell for a fuel assembly of this kind and is particularly suitable for use in a gas cooled fast reactor, being able to withstand the neutron flux and high temperature conditions in these reactors. Constructional details are given. (U.K.)

  7. Nuclear reactor fuel assembly

    International Nuclear Information System (INIS)

    1975-01-01

    A description is given of a nuclear reactor fuel assembly comprising a cluster of fuel elements supported by transversal grids so that their axes are parallel to and at a distance from each other, in order to establish interstices for the axial flow of a coolant. At least one of the interstices is occupied by an axial duct reserved for an auxiliary cooling fluid and is fitted with side holes through which the auxiliary cooling fluid is sprayed into the cluster. Deflectors extend as from a transversal grid in a position opposite the holes to deflect the cooling fluid jet towards those parts of the fuel elements that are not accessible to the auxiliary coolant. This assembly is intended for reactors cooled by light or heavy water [fr

  8. Gamma counter shutter assembly

    International Nuclear Information System (INIS)

    Aday, R.W. Jr.; Barber, D.G.

    1976-01-01

    A shutter assembly for a radioactivity measuring apparatus is described having a sample counting chamber, the assembly having a bulky solid lead cylinder with a sample access port extending therethrough for alignment with the sample chamber. The cylinder is rotated by a Geneva wheel arrangement having a drive wheel with a plurality of equi-angularly disposed pins perpendicular to the surface thereof engaging radially extending open-ended slots in a driven wheel secured to the lead cylinder for concurrent rotation therewith. The drive wheel is rotated at a constant speed with the driven wheel accelerating as a pin traverses the slot from the open end toward the driven wheel center and then decelerating as the pin traverses the reverse direction to provide precise positioning with adjacent pins engaging the open ends of adjacent slots in the stop position of the cylinder. 8 Claims, 3 Drawing Figures

  9. Mechanical seal assembly

    Science.gov (United States)

    Kotlyar, Oleg M.

    2001-01-01

    An improved mechanical seal assembly is provided for sealing rotating shafts with respect to their shaft housings, wherein the rotating shafts are subject to substantial axial vibrations. The mechanical seal assembly generally includes a rotating sealing ring fixed to the shaft, a non-rotating sealing ring adjacent to and in close contact with the rotating sealing ring for forming an annular seal about the shaft, and a mechanical diode element that applies a biasing force to the non-rotating sealing ring by means of hemispherical joint. The alignment of the mechanical diode with respect to the sealing rings is maintained by a series of linear bearings positioned axially along a desired length of the mechanical diode. Alternative embodiments include mechanical or hydraulic amplification components for amplifying axial displacement of the non-rotating sealing ring and transferring it to the mechanical diode.

  10. Mechanical Seal Assembly

    Energy Technology Data Exchange (ETDEWEB)

    Kotlyar, Oleg M.

    1999-06-18

    An improved mechanical seal assembly is provided for sealing rotating shafts with respect to their shaft housings, wherein the rotating shafts are subject to substantial axial vibrations. The mechanical seal assembly generally includes a rotating sealing ring fixed to the shaft, a non-rotating sealing ring adjacent to and in close contact with the rotating sealing ring for forming an annular seal about the shaft, and a mechanical diode element that applies a biasing force to the non-rotating sealing ring by means of hemispherical joint. The alignment of the mechanical diode with respect to the sealing rings is maintained by a series of linear bearings positioned axially along a desired length of the mechanical diode. Alternative embodiments include mechanical or hydraulic amplification components for amplifying axial displacement of the non-rotating sealing ring and transferring it to the mechanical diode.

  11. Nuclear fuel assemblies

    International Nuclear Information System (INIS)

    Natori, Hisahide; Kurihara, Kunitoshi.

    1982-01-01

    Purpose: To increase the fuel safety by decreasing the gap conductance between fuels and cladding tubes, as well as improve the reactor core controllability by rendering the void coefficient negative. Constitution: Fuel assemblies in a pressure tube comprise a tie-rod, fuel rods in a central region, and fuel rods with burnable poison in the outer circumference region. Here, B 4 C is used as the burnable poison by 1.17 % by weight ratio. The degrees of enrichment for the fissile plutonium as PuO 2 -UO 2 fuel used in the assemblies are 2.7 %, 2.7 % and 1.5 % respectively in the innermost layer, the intermediate layer and the outermost layer. This increases the burn-up degree to improve the plant utilizability, whereby the void coefficient is rendered negative to improve the reactor core controllability. (Horiuchi, T.)

  12. Experimental study of new generation WWER-1000 fuel assemblies at JSC NCCP

    International Nuclear Information System (INIS)

    Enin, A.; Rozhkov, V.; Sinikov, Y.; Ustimenko, A.; Shustov, M.

    2003-01-01

    An experimental program for the study of fuel assembly thermomechanical stability has been established together with RF SSC IPPE and Russian Scientific Center Kurchatov Institute. Assembly fragments and small dummy models of fuel assembly skeletons and fuel rod bundles have been used for the tests. The test results are used for the design selection, verification of the design codes and substantiation of operating capacity of fuel assemblies with a rigid skeleton. The mechanical characteristics of units make it possible to perform fuel assembly strength and rigidity calculations, including the cases of abnormal operation. The mechanical characteristics of the skeleton and fuel rod bundle dummy models make it possible to check for the adequacy of the fuel assembly design model. The mechanical characteristics obtained during fuel rods bundle push through experiments make it possible to substantiate the fuel assembly serviceability under the conditions of fuel rods bundle and skeleton interaction

  13. Nuclear fuel assembly

    International Nuclear Information System (INIS)

    Ueda, Tomihiro.

    1970-01-01

    The present invention relates to fuel assemblies employing wire wrap spacers for retaining uniform spatial distribution between fuel elements. Clad fuel elements are helically wound in the oxial direction with a wave-formed wire strand. The strand is therefore provided with spring action which permits the fuel elements to expand freely in the axial and radial directions so as to retain proper spacing and reduce stresses due to thermal deformation. (Ownes, K.J.)

  14. Assembling Toyota in Portugal

    OpenAIRE

    Machado, Tiago; Moniz, António

    2003-01-01

    A lot has been written over the last decade with regard to Toyota and the productive model associated to it (toyota-ism). And more specifically concerning the "(…) best-seller that changed the... sociological world" (Castillo, 1998: 31). But the case of Salvador Caetano’s Ovar Industrial Division (OID), that assembles Toyota light commercial vehicles in Portugal, allows us to put forward a sub-hypothesis that fits into the analysis schema proposed in the First GERPISA International Program – ...

  15. Fuel assembly manufacturing device

    International Nuclear Information System (INIS)

    Picard, P.; Villaeys, R.

    1995-01-01

    The device comprises a central support on which the frame is mounted, a magazine which supports the fuel rods in passages aligned with those in the frame and a traction assembly on the opposite side of the magazine and including an array of pull rods designed to be advanced through the passages in the frame, to grip respective fuel rods in magazine and to pull those rods into the passages on the return stroke. 13 figs

  16. Composite airfoil assembly

    Science.gov (United States)

    Garcia-Crespo, Andres Jose

    2015-03-03

    A composite blade assembly for mounting on a turbine wheel includes a ceramic airfoil and an airfoil platform. The ceramic airfoil is formed with an airfoil portion, a blade shank portion and a blade dovetail tang. The metal platform includes a platform shank and a radially inner platform dovetail. The ceramic airfoil is captured within the metal platform, such that in use, the ceramic airfoil is held within the turbine wheel independent of the metal platform.

  17. Value for railway capacity

    DEFF Research Database (Denmark)

    Sameni, Melody Khadem; Preston, John M.

    2012-01-01

    to analyze the efficiency of operators in transforming inputs of allocated capacity of infrastructure and franchise payments into valuable passenger service outputs while avoiding delays. By addressing operational and economic aspects of capacity utilization simultaneously, the paper deviates from existing...... DEA work on the economic efficiency of railways by considering a new combination of input-output that also incorporates quality of service. The constant and variable returns to scale models are applied to the case study of franchised passenger operators in Great Britain. The follow-up Tobit regression...

  18. Cell-Free and Cell-Based Approaches to Explore the Roles of Host Membranes and Lipids in the Formation of Viral Replication Compartment Induced by Tombusviruses.

    Science.gov (United States)

    Nagy, Peter D; Pogany, Judit; Xu, Kai

    2016-03-03

    Plant positive strand RNA viruses are intracellular infectious agents that take advantage of cellular lipids and membranes to support replication and protect viral RNA from degradation by host antiviral responses. In this review, we discuss how Tomato bushy stunt virus (TBSV) co-opts lipid transfer proteins and modulates lipid metabolism and transport to facilitate the assembly of the membrane-bound viral replicase complexes within intricate replication compartments. Identification and characterization of the proviral roles of specific lipids and proteins involved in lipid metabolism based on results from yeast (Saccharomyces cerevisiae) model host and cell-free approaches are discussed. The review also highlights the advantage of using liposomes with chemically defined composition to identify specific lipids required for TBSV replication. Remarkably, all the known steps in TBSV replication are dependent on cellular lipids and co-opted membranes.

  19. Lipid nanoparticles as drug/gene delivery systems to the retina.

    Science.gov (United States)

    del Pozo-Rodríguez, Ana; Delgado, Diego; Gascón, Alicia R; Solinís, Maria Ángeles

    2013-03-01

    This review highlights the application of lipid nanoparticles (Solid Lipid Nanoparticles, Nanostructured Lipid Carriers, or Lipid Drug Conjugates) as effective drug/gene delivery systems for retinal diseases. Most drug products for ocular disease treatment are marketed as eye drop formulations but, due to ocular barriers, the drug concentration in the retina hardly ever turns out to be effective. Up to this date, several delivery systems have been designed to deliver drugs to the retina. Drug delivery strategies may be classified into 3 groups: noninvasive techniques, implants, and colloidal carriers. The best known systems for drug delivery to the posterior eye are intravitreal implants; in fact, some of them are being clinically used. However, their long-term accumulation might impact the patient's vision. On the contrary, colloidal drug delivery systems (microparticles, liposomes, or nanoparticles) can be easily administered in a liquid form. Nanoparticular systems diffuse rapidly and are better internalized in ocular tissues than microparticles. In comparison with liposomes, nanoparticles have a higher loading capacity and are more stable in biological fluids and during storage. In addition, their capacity to adhere to the ocular surface and interact with the endothelium makes these drug delivery systems interesting as new therapeutic tools in ophthalmology. Within the group of nanoparticles, those composed of lipids (Solid Lipid Nanoparticles, Nanostructred Lipid Carriers, and Lipid Drug Conjugates) are more biocompatible, easy to produce at large scale, and they may be autoclaved or sterilized. The present review summarizes scientific results that evidence the potential application of lipid nanoparticles as drug delivery systems for the retina and also as nonviral vectors in gene therapy of retina disorders, although much more effort is still needed before these lipidic systems could be available in the market.

  20. Fourth Doctoral Student Assembly

    CERN Multimedia

    Ingrid Haug

    2016-01-01

    On 10 May, over 130 PhD students and their supervisors, from both CERN and partner universities, gathered for the 4th Doctoral Student Assembly in the Council Chamber.   The assembly was followed by a poster session, at which eighteen doctoral students presented the outcome of their scientific work. The CERN Doctoral Student Programme currently hosts just over 200 students in applied physics, engineering, computing and science communication/education. The programme has been in place since 1985. It enables students to do their research at CERN for a maximum of three years and to work on a PhD thesis, which they defend at their University. The programme is steered by the TSC committee, which holds two selection committees per year, in June and December. The Doctoral Student Assembly was opened by the Director-General, Fabiola Gianotti, who stressed the importance of the programme in the scientific environment at CERN, emphasising that there is no more rewarding activity than lear...

  1. Metrology for ITER Assembly

    International Nuclear Information System (INIS)

    Bogusch, E.

    2006-01-01

    The overall dimensions of the ITER Tokamak and the particular assembly sequence preclude the use of conventional optical metrology, mechanical jigs and traditional dimensional control equipment, as used for the assembly of smaller, previous generation, fusion devices. This paper describes the state of the art of the capabilities of available metrology systems, with reference to the previous experience in Fusion engineering and in other industries. Two complementary procedures of transferring datum from the primary datum network on the bioshield to the secondary datum s inside the VV with the desired accuracy of about 0.1 mm is described, one method using the access directly through the ports and the other using transfer techniques, developed during the co-operation with ITER/EFDA. Another important task described is the development of a method for the rapid and easy measurement of the gaps between sectors, required for the production of the customised splice plates between them. The scope of the paper includes the evaluation of the composition and cost of the systems and team of technical staff required to meet the requirements of the assembly procedure. The results from a practical, full-scale demonstration of the methodologies used, using the proposed equipment, is described. This work has demonstrated the feasibility of achieving the necessary accuracies for the successful building of ITER. (author)

  2. Ordinary General Assembly

    CERN Multimedia

    Association du personnel

    2010-01-01

    Tuesday 20 April at 10.00 Council Chamber, Bldg 503 In conformity with the Statutes of the Staff Association, an ordinary General Assembly is organized once a year (article IV.2.1). Agenda Adoption of the Agenda Approval of the Draft Minutes of the Ordinary General Assembly of 12 May 2009 Presentation and approval of the Activity Report 2009 Presentation and approval of the Financial Report 2009 Presentation and approval of the Auditors Report 2009 Programme for 2010 Presentation et and approval of the draft budget and subscription rate 2010 Modifications to the statutes of the association Election of the Election Committee Election of the Board of Auditors Miscellaneous We remind members of article IV.3.4 in the Statutes of the Association which reads: “After having dealt with all the items on the agenda, the members may, with the consent of the Assembly, have other matters discussed, but decisions may be taken only on the items listed on the agenda...

  3. SCT Barrel Assembly Complete

    CERN Multimedia

    L. Batchelor

    As reported in the April 2005 issue of the ATLAS eNews, the first of the four Semiconductor Tracker (SCT) barrels, complete with modules and services, arrived safely at CERN in January of 2005. In the months since January, the other three completed barrels arrived as well, and integration of the four barrels into the entire barrel assembly commenced at CERN, in the SR1 building on the ATLAS experimental site, in July. Assembly was completed on schedule in September, with the addition of the innermost layer to the 4-barrel assembly. Work is now underway to seal the barrel thermal enclosure. This is necessary in order to enclose the silicon tracker in a nitrogen atmosphere and provide it with faraday-cage protection, and is a delicate and complicated task: 352 silicon module powertapes, 352 readout-fibre bundles, and over 400 Detector Control System sensors must be carefully sealed into the thermal enclosure bulkhead. The team is currently verifying the integrity of the low mass cooling system, which must be d...

  4. 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...

  5. Structural characterization of lipidic systems under nonequilibrium conditions

    DEFF Research Database (Denmark)

    Yaghmur, Anan; Rappolt, Michael

    2012-01-01

    This review covers recent studies on the characterization of the dynamics of lipidic nanostructures formed via self-assembly processes. The focus is placed on two main topics: First, an overview of advanced experimental small-angle X-ray scattering (SAXS) setups combined with various sample...... negatively charged vesicles with calcium ions, and in situ hydration-induced formation of inverted-type liquid-crystalline phases loaded with the local anesthetic bupivacaine are summarized. These in situ time-resolved experiments allow real-time monitoring of the dynamics of the structural changes...

  6. 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....

  7. Tripartite assembly of RND multidrug efflux pumps.

    Science.gov (United States)

    Daury, Laetitia; Orange, François; Taveau, Jean-Christophe; Verchère, Alice; Monlezun, Laura; Gounou, Céline; Marreddy, Ravi K R; Picard, Martin; Broutin, Isabelle; Pos, Klaas M; Lambert, Olivier

    2016-02-12

    Tripartite multidrug efflux systems of Gram-negative bacteria are composed of an inner membrane transporter, an outer membrane channel and a periplasmic adaptor protein. They are assumed to form ducts inside the periplasm facilitating drug exit across the outer membrane. Here we present the reconstitution of native Pseudomonas aeruginosa MexAB-OprM and Escherichia coli AcrAB-TolC tripartite Resistance Nodulation and cell Division (RND) efflux systems in a lipid nanodisc system. Single-particle analysis by electron microscopy reveals the inner and outer membrane protein components linked together via the periplasmic adaptor protein. This intrinsic ability of the native components to self-assemble also leads to the formation of a stable interspecies AcrA-MexB-TolC complex suggesting a common mechanism of tripartite assembly. Projection structures of all three complexes emphasize the role of the periplasmic adaptor protein as part of the exit duct with no physical interaction between the inner and outer membrane components.

  8. [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).

  9. Evaluation of railway capacity

    DEFF Research Database (Denmark)

    Landex, Alex; Kaas, Anders H.; Schittenhelm, Bernd

    2006-01-01

    capacity consumptions. This paper describes the UIC 406 method and how it is expounded in Denmark. The paper describes the importance of choosing the right length of the line sections examined and how line sections with multiple track sections are examined. Furthermore, the possibility of using idle...

  10. Markets and Institutional Capacity

    DEFF Research Database (Denmark)

    Ingemann, Jan Holm

    2010-01-01

    Adequate explanations concerning the introduction of production and consumption of organic food in Denmark imply the necessity to engage a certain understanding of markets. Markets should subsequently not be seen as entities nor places but as complex relations between human actors. Further......, the establishment, maintenance and development of markets are depending on the capacity of the actors to enter into continuous and enhancing interplay....

  11. 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.

  12. [The Assembly and the national priorities ].

    Science.gov (United States)

    1997-12-01

    Social participation and attention to the actions of government have increased dramatically in Ecuador. It is crucial that political debate be broadened concerning the functioning of the National Assembly, thereby opening greater public opportunities for participation. All social groups should be guaranteed access to the debate; expansion of the public sphere is essential for development of effective mechanisms of social inclusion. Those with no capacity to defend their own interests must have a voice. The National Assembly, in addition to reforming the Constitution, must reinforce the role of public men and statesmen at all levels of government. Statesmen place the common interest over special interests and create coalitions to effect necessary changes. The National Assembly must reorient the emphasis of government activities to give all sectors equal opportunity and access to basic public services. The role of the government must be redefined, which includes being equipped with better tools for management and control and with mechanisms for accountability at a time when many believe that globalization and market forces by themselves should dictate the rhythms of political, economic, and social life. Diversity should be respected. Nongovernmental organizations can be of great assistance in fostering dialogue, cooperation, solidarity, and consensus. Ecuadorians must support the goal of human and sustainable development.

  13. Variabilidade da frequência cardíaca, lípides e capacidade física de crianças obesas e não-obesas Variabilidad de la frecuencia cardiaca, lípidos y capacidad física de niños obesos y no obesos Heart rate variability, blood lipids and physical capacity of obese and non-obese children

    Directory of Open Access Journals (Sweden)

    Mário Augusto Paschoal

    2009-09-01

    Full Text Available FUNDAMENTO: A obesidade pode afetar a modulação autonômica cardíaca, os lípides do sangue e a capacidade física. OBJETIVO: Estudar a interferência da obesidade sobre a variabilidade da frequência cardíaca (VFC, os lípides do sangue e a capacidade física de crianças obesas. MÉTODOS: Foram estudadas 30 crianças com idades entre 9 a 11 anos, divididas em dois grupos: a 15 crianças obesas (O com 10,2 ± 0,7 anos de idade e índice de massa corporal (IMC no percentil entre 95 e 97; b 15 crianças não-obesas (NO com 9,8 ± 0,7 anos de idade e IMC no percentil entre 5 e 85. Todas foram submetidas a avaliação antropométrica e clínica, análise da VFC ao repouso e a um protocolo de esforço (PE. Utilizaram-se testes não-paramétricos para comparar as variáveis entre os grupos, e o nível de significância aplicado foi de p FUNDAMENTO: La obesidad puede afectar la modulación autonómica cardiaca, los lípidos de la sangre y la capacidad física. OBJETIVO: Estudiar la interferencia de la obesidad sobre la variabilidad de la frecuencia cardiaca (VFC, los lípidos de la sangre y la capacidad física de niños obesos. MÉTODOS: Se estudiaron a 30 niños con edades entre 9 y 11 años, divididos en dos grupos: a 15 niños obesos (O con 10,2 ± 0,7 años de edad e índice de masa corporal (IMC en el percentil entre 95 y 97; b 15 niños no obesos (NO con 9,8 ± 0,7 años de edad e IMC en el percentil entre 5 y 85. Todos se sometieron a evaluación antropométrica y clínica, análisis de la VFC al reposo y a un protocolo de esfuerzo (PE. Se utilizaron pruebas no paramétricas para comparar las variables entre los grupos, y el nivel de significancia aplicado fue de p BACKGROUND: Obesity can affect the cardiac autonomic modulation, blood lipid levels and the physical capacity. OBJECTIVE: To study the effect of obesity on the heart rate variability (HRV, blood lipid levels and physical capacity of obese children. METHODS: Thirty children aged

  14. 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

  15. Self-assembling layers created by membrane proteins on gold.

    Science.gov (United States)

    Shah, D S; Thomas, M B; Phillips, S; Cisneros, D A; Le Brun, A P; Holt, S A; Lakey, J H

    2007-06-01

    Membrane systems are based on several types of organization. First, amphiphilic lipids are able to create monolayer and bilayer structures which may be flat, vesicular or micellar. Into these structures membrane proteins can be inserted which use the membrane to provide signals for lateral and orientational organization. Furthermore, the proteins are the product of highly specific self-assembly otherwise known as folding, which mostly places individual atoms at precise places in three dimensions. These structures all have dimensions in the nanoscale, except for the size of membrane planes which may extend for millimetres in large liposomes or centimetres on planar surfaces such as monolayers at the air/water interface. Membrane systems can be assembled on to surfaces to create supported bilayers and these have uses in biosensors and in electrical measurements using modified ion channels. The supported systems also allow for measurements using spectroscopy, surface plasmon resonance and atomic force microscopy. By combining the roles of lipids and proteins, highly ordered and specific structures can be self-assembled in aqueous solution at the nanoscale.

  16. Life as a matter of fat : lipids in a membrane biophysics perspective

    CERN Document Server

    Mouritsen, Ole G

    2016-01-01

    The present book gives a multi-disciplinary perspective on the physics of life and the particular role played by lipids (fats) and the lipid-bilayer component of cell membranes. The emphasis is on the physical properties of lipid membranes seen as soft and molecularly structured interfaces. By combining and synthesizing insights obtained from a variety of recent studies, an attempt is made to clarify what membrane structure is and how it can be quantitatively described. Furthermore, it is shown how biological function mediated by membranes is controlled by lipid membrane structure and organization on length scales ranging from the size of the individual molecule, across molecular assemblies of proteins and lipid domains in the range of nanometers, to the size of whole cells. Applications of lipids in nanotechnology and biomedicine are also described.   The first edition of the present book was published in 2005 when lipidomics was still very much an emerging science and lipids about to be recognized as being...

  17. A consensus approach to vertebrate de novo transcriptome assembly from RNA-seq data: Assembly of the duck (Anas platyrhynchos transcriptome.

    Directory of Open Access Journals (Sweden)

    Joanna eMoreton

    2014-06-01

    Full Text Available For vertebrate organisms where a reference genome is not available, de novo transcriptome assembly enables a cost effective insight into the identification of tissue specific or differentially expressed genes and variation of the coding part of the genome. However, since there are a number of different tools and parameters that can be used to reconstruct transcripts, it is difficult to determine an optimal method. Here we suggest a pipeline based on (1 assessing the performance of three different assembly tools (2 using both single and multiple k-mer approaches (3 examining the influence of the number of reads used in the assembly (4 merging assemblies from different tools. We use an example dataset from the vertebrate Anas platyrhynchos domestica (Pekin duck. We find that taking a subset of data enables a robust assembly to be produced by multiple methods without the need for very high memory capacity. The use of reads mapped back to transcripts (RMBT and CEGMA (Core Eukaryotic Genes Mapping Approach provides useful metrics to determine the completeness of assembly obtained. For this dataset the use of multiple k-mers in the assembly generated a more complete assembly as measured by greater number of RMBT and CEGMA score. Merged single k-mer assemblies are generally smaller but consist of longer transcripts, suggesting an assembly consisting of fewer fragmented transcripts. We suggest that the use of a subset of reads during assembly allows the relatively rapid investigation of assembly characteristics and can guide the user to the most appropriate transcriptome for particular downstream use. Transcriptomes generated by the compared assembly methods and the final merged assembly are freely available for download at http://dx.doi.org/10.6084/m9.figshare.1032613.

  18. Thermal conductivity and rectification in asymmetric archaeal lipid membranes

    Science.gov (United States)

    Youssefian, Sina; Rahbar, Nima; Van Dessel, Steven

    2018-05-01

    Nature employs lipids to construct nanostructured membranes that self-assemble in an aqueous environment to separate the cell interior from the exterior environment. Membrane composition changes among species and according to environmental conditions, which allows organisms to occupy a wide variety of different habitats. Lipid bilayers are phase-change materials that exhibit strong thermotropic and lyotropic phase behavior in an aqueous environment, which may also cause thermal rectification. Among different types of lipids, archaeal lipids are of great interest due to their ability to withstand extreme conditions. In this paper, nonequilibrium molecular dynamics simulations were employed to study the nanostructures and thermal properties of different archaeols and to investigate thermal rectification effects in asymmetric archaeal membranes. In particular, we are interested in understanding the role of bridged phytanyl chains and cyclopentane groups in controlling the phase transition temperature and heat flow across the membrane. Our results indicate that the bridged phytanyl chains decrease the molecular packing of lipids, whereas the existence of cyclopentane rings on the tail groups increases the molecular packing by enhancing the interactions between isoprenoid chains. We found that macrocyclic archaeols have the highest thermal conductivity, whereas macrocyclic archaeols with two cyclopentane rings have the lowest. The effect of the temperature on the variation of thermal conductivity was found to be progressive. Our results further indicate that small thermal rectification effects occur in asymmetric archaeol bilayer membranes at around 25 K temperature gradient. The calculated thermal rectification factor was around 0.09 which is in the range of rectification factor obtained experimentally for nanostructures such as carbon nanotubes (0.07). Such phenomena may be of biological significance and could also be optimized for use in various engineering

  19. Liner mounting assembly

    Science.gov (United States)

    Halila, Ely E. (Inventor)

    1994-01-01

    A mounting assembly includes an annular supporting flange disposed coaxially about a centerline axis which has a plurality of circumferentially spaced apart supporting holes therethrough. An annular liner is disposed coaxially with the supporting flange and includes a plurality of circumferentially spaced apart mounting holes aligned with respective ones of the supporting holes. Each of a plurality of mounting pins includes a proximal end fixedly joined to the supporting flange through a respective one of the supporting holes, and a distal end disposed through a respective one of the liner mounting holes for supporting the liner to the supporting flange while unrestrained differential thermal movement of the liner relative to the supporting flange.

  20. 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.

  1. Nuclear reactor core assembly

    International Nuclear Information System (INIS)

    Baxi, C.B.

    1978-01-01

    The object of the present invention is to provide a fast reactor core assembly design for use with a fluid coolant such as liquid sodium or carbon monoxide incorporating a method of increasing the percentage of coolant flow though the blanket elements relative to the total coolant flow through the blanket and fuel elements during shutdown conditions without using moving parts. It is claimed that deterioration due to reactor radiation or temperature conditions is avoided and ready modification or replacement is possible. (U.K.)

  2. 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

  3. Improvability of assembly systems II: Improvability indicators and case study

    Directory of Open Access Journals (Sweden)

    S.-Y. Chiang

    2000-01-01

    Full Text Available Based on the performance analysis technique developed in Part I, this paper presents improvability indicators for assembly lines with unreliable machines. In particular, it shows that assembly lines are unimprovable with respect to workforce re-distribution if each buffer is, on the average, close to being half full. These lines are unimprovable with respect to buffer capacity re-distribution if each machine is starved and blocked with almost equal frequency. In addition, the paper provides indicators for identification of bottleneck machines and bottleneck buffers. Finally, the paper reports on an application of these improvability indicators in a case study at an automotive components plant.

  4. 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.

  5. Neuronal discrimination capacity

    International Nuclear Information System (INIS)

    Deng Yingchun; Williams, Peter; Feng Jianfeng; Liu Feng

    2003-01-01

    We explore neuronal mechanisms of discriminating between masked signals. It is found that when the correlation between input signals is zero, the output signals are separable if and only if input signals are separable. With positively (negatively) correlated signals, the output signals are separable (mixed) even when input signals are mixed (separable). Exact values of discrimination capacity are obtained for two most interesting cases: the exactly balanced inhibitory and excitatory input case and the uncorrelated input case. Interestingly, the discrimination capacity obtained in these cases is independent of model parameters, input distribution and is universal. Our results also suggest a functional role of inhibitory inputs and correlated inputs or, more generally, the large variability of efferent spike trains observed in in vivo experiments: the larger the variability of efferent spike trains, the easier it is to discriminate between masked input signals

  6. Neuronal discrimination capacity

    Energy Technology Data Exchange (ETDEWEB)

    Deng Yingchun [Department of Mathematics, Hunan Normal University 410081, Changsha (China); COGS, University of Sussex at Brighton, BN1 9QH (United Kingdom); Williams, Peter; Feng Jianfeng [COGS, University of Sussex at Brighton, BN1 9QH (United Kingdom); Liu Feng [COGS, University of Sussex at Brighton, BN1 9QH (United Kingdom); Physics Department, Nanjing University (China)

    2003-12-19

    We explore neuronal mechanisms of discriminating between masked signals. It is found that when the correlation between input signals is zero, the output signals are separable if and only if input signals are separable. With positively (negatively) correlated signals, the output signals are separable (mixed) even when input signals are mixed (separable). Exact values of discrimination capacity are obtained for two most interesting cases: the exactly balanced inhibitory and excitatory input case and the uncorrelated input case. Interestingly, the discrimination capacity obtained in these cases is independent of model parameters, input distribution and is universal. Our results also suggest a functional role of inhibitory inputs and correlated inputs or, more generally, the large variability of efferent spike trains observed in in vivo experiments: the larger the variability of efferent spike trains, the easier it is to discriminate between masked input signals.

  7. Study of oil sorption behavior of filled and structured fiber assemblies made from polypropylene, kapok and milkweed fibers.

    Science.gov (United States)

    Rengasamy, R S; Das, Dipayan; Karan, C Praba

    2011-02-15

    This article reports on oil sorption behavior of fiber assemblies made up of single natural and synthetic fibers as well as blend of natural and synthetic fibers when tested with high density oil and diesel oil. A series of filled fiber assemblies were prepared from 100% polypropylene, kapok, and milkweed fibers and another series of bonded structured fiber assemblies were prepared from a 70/30 blend of kapok and polypropylene fibers and a 70/30 blend of milkweed and polypropylene fibers. It was observed that the porosity of the fiber assemblies played a very important role in determining its oil sorption capacity. The polypropylene fiber assembly exhibited the highest sorption capacity (g/g) followed by the kapok and milkweed fiber assemblies at porosity milkweed fibers have intra fiber porosities of 0.81 and 0.83, respectively. All the fiber assemblies showed higher oil sorption capacity with the high density oil as compared to the diesel oil. As the kapok and milkweed fiber have low cellulose content, hence their slow degradation is an advantage in fresh and marine water applications. The good sorption capacity of kapok and milkweed fiber assemblies along with their bio-degradable nature offer great scope for structuring them into fiber assemblies with large porosity and uniform pores to have efficient oil sorbents. Copyright © 2010 Elsevier B.V. All rights reserved.

  8. [Mutants of bacterium Azospirillum brasilense Sp245 with Omegon insertion in mmsB or fabG genes of lipid metabolism are defective in motility and flagellation].

    Science.gov (United States)

    Kovtunov, E A; Shelud'ko, A V; Chernyshova, M P; Petrova, L P; Katsy, E I

    2013-11-01

    Bacteria Azospirillum brasilense have mixed flagellation: in addition to the polar flagellum, numerous lateral flagella are formed in their cells on medium with increased density. Flagella determine the active swimming and swarming capacities of azospirilla. Using A. brasilense Sp245 as an example, we showed that the Omegon-Km artificial transposon insertion into the chromosomal gene for 3-hydroxyisobutyrate dehydrogenase (mmsB) was concurrent with the appearance of significant defects in the formation of polar flagella and with the paralysis of lateral flagella. The Sp245 mutant with the Omegon insertion into the plasmid AZOBR_p1-borne gene for 3-oxoacyl-[acyl-carrier protein]-reductase (fabG) showed the complete loss of flagella and the swarming capacity, as well as significant defects in polar flagellar assembly (though some cells are still motile in liquid medium). The viability of the A. brasilense Sp245 mutants with the Omegon insertion into the mmsB or fabG gene was not reduced. No considerable differences in the fatty acid composition of whole cell lipid extracts were found for the A. brasilense Sp245 strain and its mmsB and fabG mutants.

  9. PAYMENT CAPACITY SENSITIVITY FACTORS

    OpenAIRE

    Daniel BRÎNDESCU – OLARIU

    2014-01-01

    The current study focuses on the sensitivity of the corporate payment capacity. Through the nature of the subject, the research is based on simulating variations of the forecasted cash-flows of the companies included in the sample. The study employs 391 forecasted yearly cash-flows statements collected from 50 companies from Timis County (Romania), as well as the detailed hypotheses of the forecasts. The results of the study facilitate the determination and classification of the main se...

  10. Options on capacity imbalance

    International Nuclear Information System (INIS)

    Roggen, M.

    2002-01-01

    Since the start of this year, the Dutch energy company Nuon has been using a computer system to formulate real-time responses to national capacity imbalances in the electricity supply market. The work earns Nuon a fixed fee from TenneT (Dutch Transmission System Operator) and ensures a more stable imbalance price for everyone. The key to success has been the decision to start the project from scratch [nl

  11. CSTI High Capacity Power

    International Nuclear Information System (INIS)

    Winter, J.M.

    1989-01-01

    The SP-100 program was established in 1983 by DOD, DOE, and NASA as a joint program to develop the technology necessary for space nuclear power systems for military and civil application. During FY-86 and 87, the NASA SP-100 Advanced Technology Program was devised to maintain the momentum of promising technology advancement efforts started during Phase 1 of SP-100 and to strengthen, in key areas, the chances for successful development and growth capability of space nuclear reactor power systems for future space applications. In FY-88, the Advanced Technology Program was incorporated into NASA's new Civil Space Technology Initiative (CSTI). The CSTI Program was established to provide the foundation for technology development in automation and robotics, information, propulsion, and power. The CSTI High Capacity Power Program builds on the technology efforts of the SP-100 program, incorporates the previous NASA SP-100 Advanced Technology project, and provides a bridge to NASA Project Pathfinder. The elements of CSTI High Capacity Power development include Conversion Systems, Thermal Management, Power Management, System Diagnostics, and Environmental Interactions. Technology advancement in all areas, including materials, is required to assure the high reliability and 7 to 10 year lifetime demanded for future space nuclear power systems. The overall program will develop and demonstrate the technology base required to provide a wide range of modular power systems as well as allowing mission independence from solar and orbital attitude requirements. Several recent advancements in CSTI High Capacity power development will be discussed

  12. Progress of EMBarrel assembly

    CERN Multimedia

    Chalifour, M

    2002-01-01

    The assembly of the sixteen "M" modules into a vertical axis cylinder has been achieved last Friday, completing the first wheel of the Electromagnetic Barrel Calorimeter (see picture). With this, an important milestone in the construction of the ATLAS detector has been reached. Future steps are the rotation of the cylinder axis into horizontal position, in order to integrate the presamplers and heat exchangers by the end of October. The transportation of the wheel and its insertion into the cryostat is the next major milestone, and is planned for the beginning of 2003. The construction of the modules (the so-called "P" modules) of the second wheel is ongoing at Saclay, Annecy and CERN, and will be completed in the coming months. The assembly of the second wheel should start at CERN in February, and its insertion in the cryostat is scheduled for June 2003. This achievement is the result of a successful collaboration of all institutes involved in the construction of the EM Barrel, namely Annecy, Saclay and CE...

  13. Fuel assembly supporting structure

    International Nuclear Information System (INIS)

    Aisch, F.W.; Fuchs, H.P.; Knoedler, D.; Steinke, A.; Steven, J.

    1976-01-01

    For use in forming the core of a pressurized-water reactor, a fuel assembly supporting structure for holding a bundle of interspaced fuel rods, is formed by interspaced end pieces having holes in which the end portions of control rod guide tubes are inserted, fuel rod spacer grids being positioned by these guide tubes between the end pieces. The end pieces are fastened to the end portions of the guide tubes, to integrate the supporting structure, and in the case of at least one of the end pieces, this is done by means which releases that end piece from the guide tubes when the end pieces receive an abnormal thrust force directed towards each other and which would otherwise place the guide tubes under a compressive stress that would cause them to buckle. The spacer grids normally hold the fuel rods interspaced by distances determined by nuclear physics, and buckling of the control rod guide tubes can distort the fuel rod spacer grids with consequent dearrangement of the fuel rod interspacing. A sudden loss of pressure in a pressurized-water reactor pressure vessel can result in the pressurized coolant in the vessel discharging from the vessel at such high velocity as to result in the abnormal thrust force on the end pieces of each fuel assembly, which could cause buckling of the control rod guide tubes when the end pieces are fixed to them in the normal rigid and unyielding manner

  14. ANNUAL GENERAL ASSEMBLY

    CERN Multimedia

    2001-01-01

    All members and beneficiaries of the Pension Fund are invited to attend the Annual General Asssembly to be held in the CERN Auditorium on Wednesday 3 October 2001 at 14.30 hrs The Agenda comprises:   Opening Remarks (P. Levaux) Some aspects of risk in a pension fund (C. Cuénoud) Annual Report 2000: Presentation and results (C. Cuénoud) Copies of the Report are available from divisional secretariats. Results of the actuarial reviews (G. Maurin) Questions from members and beneficiaries Persons wishing to ask questions are encouraged to submit them, where possible, in writing in advance, addressed to Mr C. Cuénoud, Administrator of the Fund. Conclusions (P. Levaux) As usual, participants are invited to drinks after the assembly. NB The minutes of the 2000 General Assembly are available from the Administration of the Fund (tel. + 41 22 767 91 94; e-mail Graziella.Praire@cern.ch) The English version will be published next week.

  15. Bottom head assembly

    International Nuclear Information System (INIS)

    Fife, A.B.

    1998-01-01

    A bottom head dome assembly is described which includes, in one embodiment, a bottom head dome and a liner configured to be positioned proximate the bottom head dome. The bottom head dome has a plurality of openings extending there through. The liner also has a plurality of openings extending there through, and each liner opening aligns with a respective bottom head dome opening. A seal is formed, such as by welding, between the liner and the bottom head dome to resist entry of water between the liner and the bottom head dome at the edge of the liner. In the one embodiment, a plurality of stub tubes are secured to the liner. Each stub tube has a bore extending there through, and each stub tube bore is coaxially aligned with a respective liner opening. A seat portion is formed by each liner opening for receiving a portion of the respective stub tube. The assembly also includes a plurality of support shims positioned between the bottom head dome and the liner for supporting the liner. In one embodiment, each support shim includes a support stub having a bore there through, and each support stub bore aligns with a respective bottom head dome opening. 2 figs

  16. ULTRASONIC ASSEMBLY [REVIEW

    Directory of Open Access Journals (Sweden)

    PORAV Viorica

    2015-05-01

    Full Text Available The paper exposes the possibility of machine producesers to optimize the costs of clothes assembling. Ultrasonic systems being frequently utilized have many advantages on semi products of synthetic textile and technical textile. First of all, sewing – cutting process can be accomplished under high speeds and rate of losses can be minimized. Cutting seal applications are frequently used for underwear and sportswear. Slicing and unit cutting machines, as well as portable sealing machines are available for labeling sector. Products such as bag, pocket and cover can be sewed in a seamless manner for promotion purposes. All objects in terms of accessories are obtained in same standard. Our quilting machines are preferred in worldwide due to its threadless, high quality sealing. An alternative to the classic sewing assembly, with thread and needles is ultrasonic seaming. In ultrasonic welding, there are no connective bolts, nails, soldering materials, or adhesives necessary to bind the materials together. Ultrasonic is defined as acoustic frequencies above the range audible to the human ear. Ultrasonic frequencies are administered to the fabric from the sonotrode of bonding machine. The high frequency and powerful energy produced, when is release in one special environment, the ultrasound heating this environment. The ability to ultrasonic weld textiles and films depend on their thermoplastic contents and the desired end results. The paper defines the weld ability of more common textiles and films. The welding refers to all types of bonding and sealing, as in point bonding of fabric, or continuous sealing of film.

  17. PWR fuel assembly

    International Nuclear Information System (INIS)

    Yamada, Yuji.

    1995-01-01

    A lower end plug is secured to a lower end of a thimble tube. A bolt-like thimble screw is screw-coupled and fastened to a female screw disposed to the end plug by way of a bushing screw-coupled to a lower nozzle. Then, the thimble screw and the lower nozzle are welded to secure the thimble tube and the lower nozzle. The lower portion of the bushing extends near the lower surface of the lower nozzle. The extended portion is provided with a recess to which a bolt head of the thimble screw is tightly inserted and a seating-face portion against which a seating-face of the bolt head abuts. Then, the extended portion of the bushing and the lower nozzle are spot-welded on the side of the lower surface of the nozzle, to prevent rotation of the bushing. This can easily prevent the rotation of the bushing after adjustment, to simplify the assembling of the fuel assembly. (I.N.)

  18. Biodiesel production from microalgae: cultivation parameters that affect lipid production

    International Nuclear Information System (INIS)

    Arias Penaranda, Martha Trinidad; Martinez Roldan, Alfredo de Jesus; Canizares Villanueva, Rosa Olivia

    2013-01-01

    The microalgae have the capacity to mitigate CO 2 emissions and to produce lipids, which are considered with potential to obtain third-generation biofuel. This review provides updated information of the influence of culture conditions on the lipids production with high productivity and profile suitable for the biodiesel production. This document presents a compilation of research conclusions over the last 13 years around the world. in the literature consulted, the authors conclude that although the behavior of microalgae at physiological stress conditions, varies between species; the nutrients limitation, especially nitrogen and phosphorus, associated with heterotrophic growth or high irradiances in phototrophy are considered the most efficient strategies to increase the lipid content in microalgae, particularly triglycerides (consisting of saturated and monounsaturated fatty acids), which are excellent for the production of biodiesel. Also, it is reported that the lipid content increase and the number of unsaturated fatty acids decrease with the addition of small amounts of CO 2 and harvesting the biomass it the stationary phase of growth.

  19. Lipids, lipid droplets and lipoproteins in their cellular context; an ultrastructural approach

    NARCIS (Netherlands)

    Mesman, R.J.

    2013-01-01

    Lipids are essential for cellular life, functioning either organized as bilayer membranes to compartmentalize cellular processes, as signaling molecules or as metabolic energy storage. Our current knowledge on lipid organization and cellular lipid homeostasis is mainly based on biochemical data.

  20. Competence building capacity shortage

    International Nuclear Information System (INIS)

    Doorman, Gerard; Wangensteen, Ivar; Bakken, Bjoern

    2005-02-01

    The objective of the project 'Competence Building Capacity Shortage' has been 'to increase knowledge about central approaches aimed at solving the peaking capacity problem in restructured power systems'. With respect to reserve markets, a model was developed in the project to analyze the relations between reserve requirements and prices in the spot and reserve markets respectively. A mathematical model was also developed and implemented, which also includes the balance market, and has a good ability to predict the relations between these markets under various assumptions. With some further development, this model can be used fore realistic analyses of these markets in a Nordic context. It was also concluded that certain system requirements with respect to frequency and time deviation can be relaxed without adverse effects. However, the requirements to system bias, Frequency Activated Operating Reserves and Frequency Activated Contingency Reserves cannot be relaxed, the latter because they must cover the dimensioning fault in the system. On the other hand, Fast Contingency Reserves can be reduced by removing requirements to national balances. Costs can furthermore be reduced by increasingly adapting a Nordic as opposed to national approach. A model for stepwise power flow was developed in the project, which is especially useful to analyze slow power system dynamics. This is relevant when analysing the effects of reserve requirements. A model for the analysis of the capacity balance in Norway and Sweden was also developed. This model is useful for looking at the future balance under various assumptions regarding e.g. weather conditions, demand growth and the development of the generation system. With respect to the present situation, if there is some price flexibility on the demand side and system operators are able to use reserves from the demand side, the probability for load shedding during the peak load hour is close to zero under the weather conditions after

  1. Comparing Memory-Efficient Genome Assemblers on Stand-Alone and Cloud Infrastructures

    KAUST Repository

    Kleftogiannis, Dimitrios A.

    2013-09-27

    A fundamental problem in bioinformatics is genome assembly. Next-generation sequencing (NGS) technologies produce large volumes of fragmented genome reads, which require large amounts of memory to assemble the complete genome efficiently. With recent improvements in DNA sequencing technologies, it is expected that the memory footprint required for the assembly process will increase dramatically and will emerge as a limiting factor in processing widely available NGS-generated reads. In this report, we compare current memory-efficient techniques for genome assembly with respect to quality, memory consumption and execution time. Our experiments prove that it is possible to generate draft assemblies of reasonable quality on conventional multi-purpose computers with very limited available memory by choosing suitable assembly methods. Our study reveals the minimum memory requirements for different assembly programs even when data volume exceeds memory capacity by orders of magnitude. By combining existing methodologies, we propose two general assembly strategies that can improve short-read assembly approaches and result in reduction of the memory footprint. Finally, we discuss the possibility of utilizing cloud infrastructures for genome assembly and we comment on some findings regarding suitable computational resources for assembly.

  2. Comparing memory-efficient genome assemblers on stand-alone and cloud infrastructures.

    Science.gov (United States)

    Kleftogiannis, Dimitrios; Kalnis, Panos; Bajic, Vladimir B

    2013-01-01

    A fundamental problem in bioinformatics is genome assembly. Next-generation sequencing (NGS) technologies produce large volumes of fragmented genome reads, which require large amounts of memory to assemble the complete genome efficiently. With recent improvements in DNA sequencing technologies, it is expected that the memory footprint required for the assembly process will increase dramatically and will emerge as a limiting factor in processing widely available NGS-generated reads. In this report, we compare current memory-efficient techniques for genome assembly with respect to quality, memory consumption and execution time. Our experiments prove that it is possible to generate draft assemblies of reasonable quality on conventional multi-purpose computers with very limited available memory by choosing suitable assembly methods. Our study reveals the minimum memory requirements for different assembly programs even when data volume exceeds memory capacity by orders of magnitude. By combining existing methodologies, we propose two general assembly strategies that can improve short-read assembly approaches and result in reduction of the memory footprint. Finally, we discuss the possibility of utilizing cloud infrastructures for genome assembly and we comment on some findings regarding suitable computational resources for assembly.

  3. Local anesthetic effects of bupivacaine loaded lipid-polymer hybrid nanoparticles: In vitro and in vivo evaluation.

    Science.gov (United States)

    Ma, Pengju; Li, Ting; Xing, Huaixin; Wang, Suzhen; Sun, Yingui; Sheng, Xiugui; Wang, Kaiguo

    2017-05-01

    There is a compelling need for prolonged local anesthetic that would be used for analgesia with a single administration. However, due to the low molecular weight of local anesthetics (LA) (lidocaine, bupivacaine, procaine, dibucaine, etc), they present fast systemic absorption. The aim of the present study was to develop and evaluate bupivacaine lipid-polymer hybrid nanoparticles (BVC LPNs), and compared with BVC loaded PLGA nanoparticles (BVC NPs). Their morphology, particle size, zeta potential and drug loading capacity were evaluated. In vitro release study, stability and cytotoxicity were studied. In vivo evaluation of anesthetic effects was performed on animal models. A facile nanoprecipitation and self-assembly method was optimized to obtain BVC LPNs, composed of PLGA, lecithin and DSPE-PEG 2000 , of ∼175nm particle size. Compared to BVC NPs, BVC LPNs exhibited prolonged in vitro release in phosphate-buffered saline (pH=7.4). Further, BVC LPNs displayed enhanced in vitro stability in 10% FBS and lower cytotoxicity (the concentration of BVC ranging from 1.0μM to 20μM). In addition, BVC LPNs exhibited significantly prolonged analgesic duration. These results demonstrate that the LPNs could function as promising drug delivery system for overcoming the drawbacks of poor stability and rapid drug leakage, and prolonging the anesthetic effect with slight toxicity. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  4. Lipid bilayers suspended on microfabricated supports

    Science.gov (United States)

    Ogier, Simon D.; Bushby, Richard J.; Cheng, Yaling; Cox, Tim I.; Evans, Stephen D.; Knowles, Peter F.; Miles, Robert E.; Pattison, Ian

    2001-03-01

    The plasma membrane, that exists as part of many animal and plant cells, is a regulator for the transport of ions and small molecules across cell boundaries. Two main components involved are the phospholipid bilayer and the transport proteins. This paper details the construction of a micromachined support for bilayers (MSB) as a first step towards the development of highly selective and highly sensitive ion-channel based biosensors. The device consists of a ~100 micrometer hole in a polymeric support above a cavity that can hold ~25 nL of electrolyte. Electrodes attached to the structure allow the resistance of the membranes to be measured using d.c. conductivity. The MSB is made in two halves, using SU8 ultra-thick resist, which are subsequently bonded together to make the final structure. A layer of gold, surrounding the aperture, enables self-assembled monolayers of alkanethiols to be used to make the polymeric structure biocompatible. Lipid membranes have been formed over these holes with resistances comparable with those of natural membranes >10 MOhmcm^2. The ion-channel gramicidin has successfully been incorporated into the bilayer and its activity monitored. It is proposed that this type of device could be used not only for studying membrane transport phenomena but also as part of an ion-channel based biosensor.

  5. Selecting Operations for Assembler Encoding

    Directory of Open Access Journals (Sweden)

    Tomasz Praczyk

    2010-04-01

    Full Text Available Assembler Encoding is a neuro-evolutionary method in which a neural network is represented in the form of a simple program called Assembler Encoding Program. The task of the program is to create the so-called Network Definition Matrix which maintains all the information necessary to construct the network. To generate Assembler Encoding Programs and the subsequent neural networks evolutionary techniques are used.
    The performance of Assembler Encoding strongly depends on operations used in Assembler Encoding Programs. To select the most effective operations, experiments in the optimization and the predator-prey problem were carried out. In the experiments, Assembler Encoding Programs equipped with different types of operations were tested. The results of the tests are presented at the end of the paper.

  6. Gene therapy for lipid disorders

    Directory of Open Access Journals (Sweden)

    Rader Daniel J

    2000-10-01

    Full Text Available Abstract Lipid disorders are associated with atherosclerotic vascular disease, and therapy is associated with a substantial reduction in cardiovascular events. Current approaches to the treatment of lipid disorders are ineffective in a substantial number of patients. New therapies for refractory hypercholesterolemia, severe hypertriglyceridemia, and low levels of high-density lipoprotein cholesterol are needed: somatic gene therapy is one viable approach. The molecular etiology and pathophysiology of most of the candidate diseases are well understood. Animal models exist for the diseases and in many cases preclinical proof-of-principle studies have already been performed. There has been progress in the development of vectors that provide long-term gene expression. New clinical gene therapy trials for lipid disorders are likely to be initiated within the next few years.

  7. Analysis of Lipid Experiments (ALEX)

    DEFF Research Database (Denmark)

    Husen, Peter; Tarasov, Kirill; Katafiasz, Maciej

    2013-01-01

    Global lipidomics analysis across large sample sizes produces high-content datasets that require dedicated software tools supporting lipid identification and quantification, efficient data management and lipidome visualization. Here we present a novel software-based platform for streamlined data...... processing, management and visualization of shotgun lipidomics data acquired using high-resolution Orbitrap mass spectrometry. The platform features the ALEX framework designed for automated identification and export of lipid species intensity directly from proprietary mass spectral data files......, and an auxiliary workflow using database exploration tools for integration of sample information, computation of lipid abundance and lipidome visualization. A key feature of the platform is the organization of lipidomics data in "database table format" which provides the user with an unsurpassed flexibility...

  8. Modeling the Effects of Lipid Composition on Stratum Corneum Bilayers Using Molecular Dynamics Simulations

    Science.gov (United States)

    Huzil, J. Torin; Sivaloganathan, Siv; Kohandel, Mohammad; Foldvari, Marianna

    2011-11-01

    The advancement of dermal and transdermal drug delivery requires the development of delivery systems that are suitable for large protein and nucleic acid-based therapeutic agents. However, a complete mechanistic understanding of the physical barrier properties associated with the epidermis, specifically the membrane structures within the stratum corneum, has yet to be developed. Here, we describe the assembly and computational modeling of stratum corneum lipid bilayers constructed from varying ratios of their constituent lipids (ceramide, free fatty acids and cholesterol) to determine if there is a difference in the physical properties of stratum corneum compositions.

  9. Gas separation membrane module assembly

    Science.gov (United States)

    Wynn, Nicholas P [Palo Alto, CA; Fulton, Donald A [Fairfield, CA

    2009-03-31

    A gas-separation membrane module assembly and a gas-separation process using the assembly. The assembly includes a set of tubes, each containing gas-separation membranes, arranged within a housing. The housing contains a tube sheet that divides the space within the housing into two gas-tight spaces. A permeate collection system within the housing gathers permeate gas from the tubes for discharge from the housing.

  10. Integral nuclear fuel element assembly

    International Nuclear Information System (INIS)

    Schluderberg, D. C.

    1985-01-01

    An integral nuclear fuel element assembly utilizes longitudinally finned fuel pins. The continuous or interrupted fins of the fuel pins are brazed to fins of juxtaposed fuel pins or directly to the juxtaposed fuel pins or both. The integrally brazed fuel assembly is designed to satisfy the thermal and hydraulic requirements of a fuel assembly lattice having moderator to fuel atom ratios required to achieve high conversion and breeding ratios

  11. Fuel assembly and reactor core

    International Nuclear Information System (INIS)

    Aoyama, Motoo; Koyama, Jun-ichi; Uchikawa, Sadao; Bessho, Yasunori; Nakajima, Akiyoshi; Maruyama, Hiromi; Ozawa, Michihiro; Nakamura, Mitsuya.

    1990-01-01

    The present invention concerns fuel assemblies charged in a BWR type reactor and the reactor core. The fuel assembly comprises fuel rods containing burnable poisons and fuel rods not containing burnable poisons. Both of the highest and the lowest gadolinia concentrations of the fuel rods containing gadolinia as burnable poisons are present in the lower region of the fuel assembly. This can increase the spectral shift effect without increasing the maximum linear power density. (I.N.)

  12. Lipids in citrus sinensis seeds

    International Nuclear Information System (INIS)

    Hamid, S.; Liaquat, L.; Khalid, B.; Khan, J.I.

    2003-01-01

    The seed oil of citrus sinensis when subjected to different physicochemical tests showed moisture 13.2%, ash 7.5%, ester value 1.29%, free fatty acid 0.4%. iodine value 65.0% and protein value 6.0%. According to lipid analysis. the oil was classified into hydrocarbons. wax esters, sterol esters, triglycerides. free fatty acids, 1,3 and 1,2 diglycerides, alcohols, sterols, monoglycerides, phosphatidylethanolamines, phosphatidylcholines and lysophosphatidylethanolamines. The fatty acid (C/sub 12.0/ - C/sub 21.0/) composition of all lipid classes was determined with the help of thin layer and gas liquid chromatography. (author)

  13. Sensing voltage across lipid membranes

    Science.gov (United States)

    Swartz, Kenton J.

    2009-01-01

    The detection of electrical potentials across lipid bilayers by specialized membrane proteins is required for many fundamental cellular processes such as the generation and propagation of nerve impulses. These membrane proteins possess modular voltage-sensing domains, a notable example being the S1-S4 domains of voltage-activated ion channels. Ground-breaking structural studies on these domains explain how voltage sensors are designed and reveal important interactions with the surrounding lipid membrane. Although further structures are needed to fully understand the conformational changes that occur during voltage sensing, the available data help to frame several key concepts that are fundamental to the mechanism of voltage sensing. PMID:19092925

  14. Rocket Assembly and Checkout Facility

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Integrates, tests, and calibrates scientific instruments flown on sounding rocket payloads. The scientific instruments are assembled on an optical bench;...

  15. Assembly of the PLT device

    International Nuclear Information System (INIS)

    Marino, R.

    1975-11-01

    The assembly of the PLT device began in June 1974 with a preassembly of the mechanical structure at a remote site. The preassembly sequence incorporated final fabrication procedures with an initial staging operation. This successful staging/fabrication procedure proved to be an invaluable asset when the final assembly was started in August 1974. The assembly continued with the initial reassembly of the previously tested structural components at the final machine site. Construction was interrupted at several points to allow for toroidal field coil, vacuum vessel, and poloidal coil installation. Two phases of toroidal field coil power tests were included in the assembly sequence prior to, and just after the vacuum vessel insertion

  16. Next-generation transcriptome assembly

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Jeffrey A.; Wang, Zhong

    2011-09-01

    Transcriptomics studies often rely on partial reference transcriptomes that fail to capture the full catalog of transcripts and their variations. Recent advances in sequencing technologies and assembly algorithms have facilitated the reconstruction of the entire transcriptome by deep RNA sequencing (RNA-seq), even without a reference genome. However, transcriptome assembly from billions of RNA-seq reads, which are often very short, poses a significant informatics challenge. This Review summarizes the recent developments in transcriptome assembly approaches - reference-based, de novo and combined strategies-along with some perspectives on transcriptome assembly in the near future.

  17. Seismic behaviour of fuel assembly

    Energy Technology Data Exchange (ETDEWEB)

    Song, Heuy Gap; Jhung, Myung Jo [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1993-11-01

    A general approach for the dynamic time-history analysis of the reactor core is presented in this paper as a part of the fuel assembly qualification program. Several detailed core models are set up to reflect the placement of the fuel assemblies within the core shroud. Peak horizontal responses are obtained for each model for the motions induced from earthquake. The dynamic responses such as fuel assembly shear force, bending moment and displacement, and spacer grid impact loads are carefully investigated. Also, the sensitivity responses are obtained for the earthquake motions and the fuel assembly non-linear response characteristics are discussed. (Author) 9 refs., 24 figs., 1 tab.

  18. Airfoil nozzle and shroud assembly

    Science.gov (United States)

    Shaffer, J.E.; Norton, P.F.

    1997-06-03

    An airfoil and nozzle assembly are disclosed including an outer shroud having a plurality of vane members attached to an inner surface and having a cantilevered end. The assembly further includes a inner shroud being formed by a plurality of segments. Each of the segments having a first end and a second end and having a recess positioned in each of the ends. The cantilevered end of the vane member being positioned in the recess. The airfoil and nozzle assembly being made from a material having a lower rate of thermal expansion than that of the components to which the airfoil and nozzle assembly is attached. 5 figs.

  19. Blood lipid metabolites and meat lipid peroxidation responses of ...

    African Journals Online (AJOL)

    Esnart Mukumbo

    2017-06-19

    Jun 19, 2017 ... Fat and protein contents of thigh muscle and abdominal fat weight were measured and reported. Chickens fed LPO had greater serum triacylglycerol and very low ... favour lipid peroxidation, inhibit synthesis of higher homologous of ... The ambient temperature was gradually decreased from 33 °C at first.

  20. Blood lipid metabolites and meat lipid peroxidation responses of ...

    African Journals Online (AJOL)

    Blood samples were collected from broilers to evaluate serum biochemical metabolites on day 41. Thigh meat samples were provided and analysed after 1, 5 and 10 days' storage to evaluate lipid peroxidation at the end of the experiment. Fat and protein contents of thigh muscle and abdominal fat weight were measured ...