Sample records for spiro-crypta phosphazene derivatives

  1. Application of a phosphazene derivative as a flame retardant for cotton fabric using conventional method and supercritical CO2

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conventional pad-dry-cure (non-scCO2) and supercritical carbon dioxide (scCO2) application methods were investigated to study the effectiveness of a phosphazene derivative as a flame retardant on cotton fabric. 1,1',4,5-tetrahydrotrispiro[1,3,2-diazaphosphole-2,2'-[1,3,5,2,4,6]triazatriphosphinine-4...

  2. Phosphazenes 2013

    SciTech Connect

    Frederick F Stewart

    2015-01-01

    The unique chemistry of phosphazenes continues to be developed. A phosphazene, which is defined as a P(V) and N structure with these atoms attached to each other by double bonds, exhibits a unique two-step general synthesis in which the P=N skeleton is intially formed, followed by nucleophilic substitution to provide final form. In general, a pure inorganic phosphazene is assembled, typically with halide substitution at P. The lability of the P-X bond allows for substitution with a nearly unlimited variety of nucleophiles. Final substitution can yield stable structures amenable to both characterization and function. This article discusses some of the more recent developments in phosphazene chemistry and seeks to provide the reader a picture of the current state of the art.

  3. Phosphazenes (2010)

    SciTech Connect

    Frederick F. Stewart

    2010-12-01

    A review of the literature published in 2009 shows an increase in the number of publications addressing phosphazene chemistry over 2008, which suggests a continued strong interest in these intriguing materials. Prominently is the emphasis in the bioactive and biocompatible nature of these materials; although many other applications also exist. Phosphazenes are formed from a phosphorus and nitrogen backbone with pendant group attachments at phosphorus. Typically, they are drawn with alternating single and double bonds between the alternating phosphorus and nitrogen atoms. However, unlike the familiar poly(acetylenes) or poly(thiophenes), the phosphazene backbone is not electrically conductive as there are orbital nodes at phosphorus. Thus, electron delocalization occurs between phosphorus atoms, but not through them. The result of this bonding is a highly flexible backbone that can be controlled through adoit pendant group attachment revealing numerous materials and structures. In this review, novel aspects of the chemistry, structure, and applications of phosphazenes will be discussed.

  4. Phosphorus-nitrogen compounds. 21. Syntheses, structural investigations, biological activities, and DNA interactions of new N/O spirocyclic phosphazene derivatives. The NMR behaviors of chiral phosphazenes with stereogenic centers upon the addition of chiral solvating agents.

    PubMed

    I?iklan, Muhammet; Asmafiliz, Nuran; Ozalp, Ezgi Elif; Ilter, Elif Ece; Kiliç, Zeynel; Co?ut, Bünyemin; Ye?ilot, Serkan; Kiliç, Adem; Oztürk, Asli; Hökelek, Tuncer; Bilir, L Yasemin Koç; Açik, Leyla; Akyüz, Emel

    2010-08-01

    The reactions of hexachlorocyclotriphosphazatriene, N(3)P(3)Cl(6), with N/O-donor-type N-alkyl (or aryl)-o-hydroxybenzylamines (1a-1e) produce mono- (2a-2e), di- (3a-3d), and tri- (4a and 4b) spirocyclic phosphazenes. The tetrapyrrolidino monospirocyclic phosphazenes (2f-2i) are prepared from the reactions of partly substituted compounds (2a-2d) with excess pyrrolidine. The dispirodipyrrolidinophosphazenes (3e-3h) and trispirophosphazenes (3i-3k) are obtained from the reactions of trans-dispirophosphazenes with excess pyrrolidine and sodium (3-amino-1-propanoxide), respectively. Compounds 3a-3d have cis and trans geometric isomers. Only the trans isomers of these compounds are isolated. Compounds 3a-3h have two stereogenic P atoms. They are expected to be in cis (meso) and trans (racemic) geometric isomers. In the trans trispiro compounds (3i-3k), there are three stereogenic P atoms. They are expected to be in racemic mixtures. The stereogenic properties of 3a-3k are confirmed by (31)P NMR spectroscopy upon the addition of the chiral solvating agent; (S)-(+)-2,2,2-trifluoro-1-(9'-anthryl)ethanol. The molecular structures of 3i-3k, 4a, and 4b look similar to a propeller, where the chemical environment of one P atom is different from that of others. Additionally, 4a and 4b are also expected to exist as cis-trans-trans and cis-cis-cis geometric isomers, but both of them are found to be in cis-trans-trans geometries. The solid-state structures of 2a, 2e, 2f, 3e, and 3f are determined by X-ray crystallography. The compounds 2f-2i, 3e-3i, and 3k are screened for antibacterial activity against gram-positive and gram-negative bacteria and for antifungal activity against yeast strains. These compounds (except 3f) have shown a strong affinity against most of the bacteria. Minimum inhibitory concentrations (MIC) are determined for 2f-2i, 3e-3i, and 3k. DNA binding and the nature of interaction with pUC18 plasmid DNA are studied. The compounds 2f-2i, 3e-3i, and 3k induce changes on the DNA mobility. The prevention of BamHI and HindIII digestion (except 2g) with compounds indicates that the compounds bind with nucleotides in DNA. PMID:20583756

  5. Phosphazene membranes for gas separations

    DOEpatents

    Stewart, Frederick F.; Harrup, Mason K.; Orme, Christopher J.; Luther, Thomas A.

    2006-07-11

    A polyphosphazene having a glass transition temperature ("T.sub.g") of approximately -20.degree. C. or less. The polyphosphazene has at least one pendant group attached to a backbone of the polyphosphazene, wherein the pendant group has no halogen atoms. In addition, no aromatic groups are attached to an oxygen atom that is bound to a phosphorus atom of the backbone. The polyphosphazene may have a T.sub.g ranging from approximately -100.degree. C. to approximately -20.degree. C. The polyphosphazene may be selected from the group consisting of poly[bis-3-phenyl-1-propoxy)phosphazene], poly[bis-(2-phenyl-1-ethoxy)phosphazene], poly[bis-(dodecanoxypolyethoxy)-phosphazene], and poly[bis-(2-(2-(2-.omega.-undecylenyloxyethoxy)ethoxy)ethoxy)phosphazene]- . The polyphosphazene may be used in a separation membrane to selectively separate individual gases from a gas mixture, such as to separate polar gases from nonpolar gases in the gas mixture.

  6. Phosphorus-nitrogen compounds: New spiro-cyclic phosphazene derivatives. Structure of 4?,4?,6?,6?-tetrachloro-3,4-dihydro-3-(3-methylpyridin-2-yl) spiro-[1,3,2-benzoxazaphosphinine-2,2?-(2? 5,4? 5,6? 5-cyclotriphosphazene)]. Part XII

    Microsoft Academic Search

    Dal Hakan; Safran Serap; Süzen Yasemin; Hökelek Tuncer; Zeynel K?l?ç

    2005-01-01

    The condensation reactions of {N-[(2-hydroxyphenylmethyl)amino]-methylpyridines (5–8) with trimer, N3P3Cl6, have been afforded partially substituted novel spiro-cyclic phosphazene derivatives (9–12) (Scheme 1). Compounds (9–12) have been characterized by elemental analyses, FTIR, 1H–, 13C–, 31P-NMR, HETCOR, and MS. The structure of the spiro-cyclic phosphazene (9) has been examined crystallographically. It crystallizes in the P21\\/n space group with a=10.7906(10)Å, b=8.5625(17)Å, c=21.187(5)Å, ?=91.298(12)°, V=1957.1(6)Å3,

  7. Phosphazene polymer containing composites and method for making phosphazene polymer containing composites

    DOEpatents

    Allen, Charles A. (Idaho Falls, ID); Grey, Alan E. (Idaho Falls, ID); McCaffrey, Robert R. (Milford, MA); Simpson, Brenda M. (Idaho Falls, ID); Stone, Mark L. (Idaho Falls, ID)

    1994-01-01

    A composite is produced by first coating a reinforcing material with an inorganic phosphazene compound and then polymerizing the phosphazene compound so as to confer superior thermal, physical and chemical resistance qualities to the composite.

  8. Phosphazene polymer containing composites and method for making phosphazene polymer containing composites

    DOEpatents

    Allen, Charles A.; Grey, Alan E.; McCaffrey, Robert R.; Simpson, Brenda M.; Stone, Mark L.

    1994-05-03

    A composite is produced by first coating a reinforcing material with an inorganic phosphazene compound and then polymerizing the phosphazene compound so as to confer superior thermal, physical and chemical resistance qualities to the composite.

  9. Thermal degradation chemistry of poly[bis(phenoxy)phosphazene

    E-print Network

    Maynard, Shawn Joseph

    1989-01-01

    THERMAL DEGRADATION CHEMISTRY OF POLY[BIS(PHENOXY)PHOSPHAZENE] A Thesis by SHAWN JOSEPH MAYNARD Submitted to the Office of Graduate Studies of Texas A&M University in Partial fulfillment of the requirements for the degree of MASTER... in order to clarify the degradation process. From these studies triphenyl- phosphate is shown to be a degradation product of the cyclic trimer, cyclic tetramer, and the chloro-derivatives of those compounds. The observation of phenyl amines from...

  10. Poly(imidazole\\/DMAEA)phosphazene\\/DNA self-assembled nanoparticles for gene delivery: Synthesis and in vitro transfection

    Microsoft Academic Search

    Yongxin Yang; Zhenghong Xu; Jingui Jiang; Yu Gao; Wangwen Gu; Lingli Chen; Xiaozheng Tang; Yaping Li

    2008-01-01

    A new cationic derivate of polyphosphazene with imidazole and 2-dimethylaminoethylamino (DMAEA) as side groups, poly(imidazole\\/DMAEA)phosphazene (PIDP), was synthesized and investigated for gene delivery. The half-lives of PIDP degradation under neutral (pH 7.4) and acidic conditions (pH 5.0) were 22 and 3 days at 37 °C, respectively. The cytotoxicity of PIDP assayed by MTT was much lower than that of poly(2-dimethylaminoethylamino)phosphazene (PDAP) and

  11. Hybrid phosphazene anodes for energy storage applications

    SciTech Connect

    Eric J. Dufek; Mark L. Stone; Kevin L. Gering; Frederick F. Stewart; David Jamison; Aaron D. Wilson; Lucia M. Petkovic; Mason K. Harrup; Harry W. Rollins

    2014-12-01

    The use of hybrid cyclic phosphazene polymer/graphite anodes, where the phosphazene serves as distributed loci for Li deposition, has been investigated. Capacity within the hybrid system was found to occur reversibly in distinct regions. At the most positive voltages, above 0.06 V vs Li/Li+, the capacity was associated mostly with Li+ intercalation into graphite. In the most negative region, deposition of Li within the polymer was the predominate mechanism. A transitional region is inferred by the data whereby bulk aggregation or clustering of Li atoms occurs in proximity to the phosphazene sites that then serve as a template for more widespread population of Li within the anode at higher voltages, akin to a nucleation process. In full cells with a mixed oxide cathode, controlling the extent of Li deposition by limiting the charging voltage to 4.45 V enabled repeated cycling with no loss in capacity. Capacities as high as 183 mAh g-1 have been achieved for systems containing as little as 10% graphite while retaining coulombic efficiencies of 98% over 50 cycles. This level of cycling equates to the deposition of 7.4 Li per cyclic phosphazene.

  12. Poly(imidazole/DMAEA)phosphazene/DNA self-assembled nanoparticles for gene delivery: synthesis and in vitro transfection.

    PubMed

    Yang, Yongxin; Xu, Zhenghong; Jiang, Jingui; Gao, Yu; Gu, Wangwen; Chen, Lingli; Tang, Xiaozheng; Li, Yaping

    2008-05-01

    A new cationic derivate of polyphosphazene with imidazole and 2-dimethylaminoethylamino (DMAEA) as side groups, poly(imidazole/DMAEA)phosphazene (PIDP), was synthesized and investigated for gene delivery. The half-lives of PIDP degradation under neutral (pH 7.4) and acidic conditions (pH 5.0) were 22 and 3 days at 37 degrees C, respectively. The cytotoxicity of PIDP assayed by MTT was much lower than that of poly(2-dimethylaminoethylamino)phosphazene (PDAP) and PEI 25K. PIDP could condense DNA into nanoparticles with a size around 100 nm and zeta potential (+25 mV) at the ratio of 10:1 (PIDP/DNA, w/w). The transfection efficiency of PIDP/DNA complex nanoparticles (PICNs) against 293T, COS-7 and Hela cells was much higher than that of PDAP/DNA complexes nanoparticles (PDCNs) and PEI/DNA complexes nanoparticles (PECNs) at 10:1 (polymer/DNA, w/w). Therefore, PIDP could be a safe, efficient and promising cationic polymer for gene therapy. PMID:18346807

  13. Biomass to fuels: A water-free process for biodiesel production with phosphazene catalysts

    Microsoft Academic Search

    Miriam Cerro-Alarcón; Avelino Corma; Sara Iborra; Juan Pedro Gómez

    2008-01-01

    Non-ionic triamino(imino)phosphoranes (phosphazenes) give excellent results as base catalysts for the water-free alcoholysis of vegetable fatty esters. Two phosphazene catalysts, with different intrinsic basicities, P1-t-Bu and P4-t-Bu, together with reaction parameters, such as temperature, alcohol\\/oil molar ratio, or catalyst concentration, have been studied. It was found that activity can be directly correlated to the basicity of the catalyst. Very high

  14. Design, synthesis, and molecular recognition of phosphazene materials

    NASA Astrophysics Data System (ADS)

    Sunderland, Nicolas Jean

    2000-08-01

    This thesis represents several innovative approaches in the modification of polymers and solid-state hosts in order to obtain novel microstructures and properties. The first approach involves the use of cyclotriphosphazenes, a versatile class of hosts that generate tunnel clathrate adducts. Tris(o-phenylenedioxy)cyclotriphosphazene was found to form hexagonal host-guest inclusion adducts (clathrates) with the polymers: cis-1,4-polybutadiene, trans-1,4-polyisoprene, polyethylene, poly(ethylene oxide) and polytetrahydrofuran. Single crystal X-ray diffraction studies of both the polyethylene and poly(ethylene oxide) inclusion adduct revealed the presence of individual polymer chains extended along tunnel-like voids within the host lattice. Tris(o-phenylenedioxy)cyclotriphosphazene can entrap and separate various polymers and small molecules within its tunnels based on their microstructure, molecular weight, and end-group functionality. Inclusion adducts with various polymers show a preferential inclusion for the polymer that will best stabilize the hexagonal structure of the host. Separations based on end-groups show preferential inclusion of the species with the more hydrophobic end-groups. Polymers and small molecule hydrocarbons with higher molecular weights are preferentially included within the tunnel compared to analogues with lower molecular weights. The synthesis and inclusion properties of a new clathration host, tris(3,6-dimethylphenylenedioxy)cyclotriphosphazene, is described. The guest-free structure has a triclinic unit cell. The dioxane inclusion adduct crystallizes in a monoclinic system. The guest occupies a cage-like void located between the phosphazene rings. The poly(tetramethylene oxide) adduct crystallizes in a hexagonal system, with the guest located in tunnels created along the c-axis. Adduct formation also with tetrahydrofuran, methylene chloride, polyethylene and cis-polybutadiene. Modification of polymer properties is investigated by using a Staudinger reaction to attach cyclic phosphazene trimers bearing azide groups to phosphorus(III) atoms pendent to an organic polymer or co-polymer backbone. Diphenyl- p-styrylphosphine was polymerized via free radical or anionic methods and subsequently reacted with N3P3(OCH2CF 3)5(N3) and N3P3(OC 6H5)(N3). Fire retardance is improved these homopolymers, and also for polystyrene and poly(methyl methacrylate) co-polymers after reaction with the azide cyclic trimers. The ability to control the molecular weight and architecture of poly[bis(methoxyethoxy)ethoxy)phosphazene], a known solid polymer electrolyte, allows for a systematic study of the effect of molecular weight and architecture on conductivity. The mechanism of ion transport in these linear and star-branched systems is discussed.

  15. Unsaturated phosphazenes as co-solvents for lithium-ion battery electrolytes

    NASA Astrophysics Data System (ADS)

    Harrup, Mason K.; Rollins, Harry W.; Jamison, David K.; Dufek, Eric J.; Gering, Kevin L.; Luther, Thomas A.

    2015-03-01

    This paper covers the synthesis and use of a related family of cyclic phosphazene solvents containing terminal unsaturations that are being considered as electrolyte additives in lithium-ion cells. A brief synopsis on the synthesis and purification of these compounds is given. Data will be presented that covers physical and chemical properties of the phosphazenes as well as the properties when blended at various levels with representative organic carbonate baseline solvents. Electrochemical cycling data will be presented using commercially available electrode couples as well as studies focusing on cell performance at early lifetime as well as after repeated cycles. Conclusions regarding the effect of the unsaturated phosphazene compounds and their interaction with various alkyl carbonates, and their effect on cell performance will be presented.

  16. A crystallographically isolated dimeric hydrolyzed chloro­phosphazene dianion

    PubMed Central

    Panzner, Matthew J.; Youngs, Wiley J.; Tessier, Claire A.

    2009-01-01

    Single crystals of the title compound bis[bis­(1-ethyl-3-methyl-imidazol-2-yl­idene)silver(I)] 1,5,5,7,11,11-hexa­chloro-2,8-di­oxa-4,6,10,12,13,14-hexa­aza-1?5,3,5?5,7?5,9,11?5-hexa­phospha­tricyclo­[7.3.1.13,7]tetra­deca-1(13),4,7(14),10-tetra­ene-6,12-diide 3,9-dioxide, [Ag(C6H10N2)2](Cl6N6O4P6)0.5, were isolated from the reaction of the silver N-heteocyclic carbene complex [Ag(C6H10N2)2]Cl and hexa­chloro­cyclo­triphos­phazene [NPCl2]3 in the presence of water. The asymmetric unit contains one silver carbene cation with the carbene ligands bound to the Ag(I) in an almost linear arrangement and one half of a hydrolyzed phosphazene dianion. The second cation and additional half of the anion are generated by an inversion center. PMID:21581471

  17. Automated solid-phase radiofluorination using polymer-supported phosphazenes.

    PubMed

    Mathiessen, Bente; Zhuravlev, Fedor

    2013-01-01

    The polymer supported phosphazene bases PS-P?(tBu) and the novel PS-P?(PEG) allowed for efficient extraction of [¹?F]F? from proton irradiated [¹?O]H?O and subsequent radiofluorination of a broad range of substrates directly on the resin. The highest radiochemical yields were obtained with aliphatic sulfonates (69%) and bromides (42%); the total radiosynthesis time was 35-45 min. The multivariate analysis showed that the radiochemical yields and purities were controlled by the resin load, reaction temperature, and column packing effects. The resins could be reused several times with the same or different substrates. The fully automated on-column radiofluorination methodology was applied to the radiosynthesis of the important PET radiotracers [¹?F]FLT and [¹?F]FDG. The latter was produced with 40% yield on a 120 GBq scale and passed GMP-regulated quality control required for commercial production of [1¹?F]FDG. The combination of compact form factor, simplicity of [¹?F]F? recovery and processing, and column reusability can make solid phase radiofluorination an attractive radiochemistry platform for the emerging dose-on-demand instruments for bedside production of PET radiotracers. PMID:23999726

  18. A Study of Novel Hexavalent Phosphazene Salts as Draw Solutes in Forward Osmosis

    SciTech Connect

    Mark L. Stone; Aaron D. Wilson; Mason K. Harrup; Frederick F. Stewart

    2013-03-01

    Two novel multi-valent salts based on phosphazene chemistry have been synthesized and characterized as forward osmosis (FO) draw solutes. Commercially obtained hexachlorocyclotriphosphazene was reacted with the sodium salt of 4-ethylhydroxybenzoate to yield hexa(4-ethylcarboxylatophenoxy)phosphazene. Hydrolysis, followed by and neutralization with NaOH or LiOH, of the resulting acidic moieties yielded water soluble sodium and lithium phosphazene salts, respectively. Degrees of dissociation were determined through osmometry over the range of 0.05-0.5 m, giving degrees of 3.08-4.95 per mole, suggesting a high osmotic potential. The Li salt was found to be more ionized in solution than the sodium salt, and this was reflected in FO experiments where the Li salt gave higher initial fluxes (~ 7 L/m2h) as compared to the sodium salt (~6 L/m2h) at identical 0.07 m draw solution concentrations at 30 °C. Longer term experiments revealed no detectable degradation of the salts; however some hydrolysis of the cellulose acetate membrane was observed, presumably due to the pH of the phosphazene salt draw solution (pH = ~8).

  19. Synthesis of novel epoxy-group modified phosphazene-containing nanotube and its reinforcing effect in epoxy resin

    Microsoft Academic Search

    Xiaojun Gu; Xiaobin Huang; Hao Wei; Xiaozhen Tang

    2011-01-01

    In this work, novel epoxy-group modified phosphazene-containing nanotubes (EPPZTs) were successfully synthesized through the reaction between epichlorohydrin and phosphazene-containing nanotubes with active hydroxyl groups. The structure was characterized by Fourier transform infrared spectroscopy (FTIR) and the morphology was investigated by scanning electron microscopy (SEM). EPPZTs\\/epoxy resin composites were prepared by introducing EPPZTs into epoxy resin matrix (EP618). Impact strength and

  20. In vivo tumor transfection mediated by polyplexes based on biodegradable poly(DMAEA)-phosphazene

    Microsoft Academic Search

    Holger K. de Wolf; Jordy Luten; Cor J. Snel; Christien Oussoren; Wim E. Hennink; Gert Storm

    2005-01-01

    In recent years, increasing interest is being paid to the design of transfectants based on non-toxic and biodegradable polymers for gene therapy purposes. We recently reported on a novel, biodegradable polymer, poly(2-dimethylamino ethylamino)phosphazene (p(DMAEA)-ppz) for use in non-viral gene delivery. In this study, the biodistribution and in vivo transfection efficiency of polyplexes composed of plasmid DNA and p(DMAEA)-ppz were investigated

  1. Phenalene-phosphazene complexes: Effect of exocyclic charge densities on the cyclotriphosphazene ring system

    SciTech Connect

    Haddon, R.C.; Chichester-Hicks, S.V.; Mayo, S.L.

    1988-06-01

    The synthesis and properties of a new series of 1,9-diamino-substituted phenalene complexes of the cyclotriphosphazene ring system is described. One of the compounds is shown to be amphoteric, and this behavior allows an examination of the response of the phosphazene linkage to variations in exocyclic charge density at the spiro center in a plane perpendicular to the cyclotriphosphazene ring system. /sup 31/P NMR spectroscopy indicates that substituent lone pairs with this orientation are not effective in long-range delocalization within the phosphazene linkage (in accord with their theoretical model of spiro delocalization). An x-ray crystal structure of one compound (7) identifies the presence of clathrated molecules of chloroform together with doubly hydrogen-bonded pairs of the phenalene-phosphazene complexes in the lattice. Crystal data for 7 (C/sub 13/H/sub 8/Cl/sub 4/N/sub 5/P/sub 3/ /times/ CHCl/sub 3/): monoclinic space group P2/sub 1//c, a = 12.401 (4) /angstrom/, b = 28.404 (6) /angstrom/, c = 12.962 (3) /angstrom/, /beta/ = 91.76 (2)/degree/, V = 4564 (2) /angstrom//sup 3/, Z = 8, R = 0.050 for 4525 reflections. 24 references, 3 figures, 7 tables.

  2. Synthesis and tribological behavior of ionic liquid substituted fluoroalkoxycyclophosphazene derivatives in steel-steel contacts

    Microsoft Academic Search

    Jinlong Li; Dapeng Feng; Yongmin Liang; Yanqiu Xia; Weimin Liu

    2010-01-01

    Purpose – The purpose of this paper is to synthesize a series of cyclophosphazene derivatives with better tribological properties. Design\\/methodology\\/approach – To improve the adsorptivity to substrate, a series of cyclophosphazene derivatives substituted with ionic liquids were synthesized. The lubricity characteristics of phosphazene derivatives were evaluated on an Optimol SRV IV oscillating friction and wear tester. Scanning electron microscope and

  3. Degradable PEG-folate coated poly(DMAEA-co-BA)phosphazene-based polyplexes exhibit receptor-specific gene expression.

    PubMed

    Luten, J; van Steenbergen, M J; Lok, M C; de Graaff, A M; van Nostrum, C F; Talsma, H; Hennink, W E

    2008-03-01

    A new cationic biodegradable polyphosphazene was developed, bearing both pendant primary and tertiary amine side groups, poly(2-dimethylaminoethylamine-co-diaminobutane)phosphazene (poly(DMAEA-co-BA)phosphazene). PEG and PEG-folate were coupled to polyplexes based on this poly(DMAEA-co-BA)phosphazene, leading to small (size 100 and 120nm, respectively) and almost neutral particles. In vitro tissue culture experiments showed a low cytotoxicity of both uncoated and coated polyplexes. However, the PEG coated polyplexes showed a 2-fold lower transfection activity in OVCAR 3 cells as compared to the uncoated polyplexes. On the other hand, the PEG-folate coated polyplexes had a 3-fold higher transfection than the PEGylated polyplexes. When free folate was added to the transfection medium, only the transfection activity of the targeted polyplexes was reduced, indicating internalization of the targeted PEG polyplexes via the folate receptor. Confocal laser scanning microscopy confirmed a lower binding and uptake of the PEGylated polyplexes by OVCAR-3 cells when compared to uncoated and folate-PEGylated polyplexes. While uncoated polyplexes induced aggregation of erythrocytes at polymer concentrations of 0.09microg/mL, the PEGylated systems could be incubated at ten times higher concentration before aggregation occurred indicating excellent shielding of the surface charge of the polyplexes by grafting of PEG. In conclusion, the targeted delivery of poly(DMAEA-co-BA)phosphazene bases polyplexes and their improved compatibility with erythrocytes makes them interesting for in vivo applications. PMID:18207707

  4. Phosphazene Based Additives for Improvement of Safety and Battery Lifetimes in Lithium-Ion Batteries

    SciTech Connect

    Mason K Harrup; Kevin L Gering; Harry W Rollins; Sergiy V Sazhin; Michael T Benson; David K Jamison; Christopher J Michelbacher

    2011-10-01

    There need to be significant improvements made in lithium-ion battery technology, principally in the areas of safety and useful lifetimes to truly enable widespread adoption of large format batteries for the electrification of the light transportation fleet. In order to effect the transition to lithium ion technology in a timely fashion, one promising next step is through improvements to the electrolyte in the form of novel additives that simultaneously improve safety and useful lifetimes without impairing performance characteristics over wide temperature and cycle duty ranges. Recent efforts in our laboratory have been focused on the development of such additives with all the requisite properties enumerated above. We present the results of the study of novel phosphazene based electrolytes additives.

  5. Fluorinated Phosphazene Co-solvents for Improved Thermal and Safety Performance in Lithium-Ion Battery Electrolytes

    SciTech Connect

    Harry W. Rollins; Mason K. Harrup; Eric J. Dufek; David K. Jamison; Sergiy V. Sazhin; Kevin L. Gering; Dayna L. Daubaras

    2014-10-01

    The safety of lithium-ion batteries is coming under increased scrutiny as they are being adopted for large format applications especially in the vehicle transportation industry and for grid-scale energy storage. The primary short-comings of lithium-ion batteries are the flammability of the liquid electrolyte and sensitivity to high voltage and elevated temperatures. We have synthesized a series of non-flammable fluorinated phosphazene liquids and blended them with conventional carbonate solvents. While the use of these phosphazenes as standalone electrolytes is highly desirable, they simply do not satisfy all of the many requirements that must be met such as high LiPF6 solubility and low viscosity, thus we have used them as additives and co-solvents in blends with typical carbonates. The physical and electrochemical properties of the electrolyte blends were characterized, and then the blends were used to build 2032-type coin cells which were evaluated at constant current cycling rates from C/10 to C/1. We have evaluated the performance of the electrolytes by determining the conductivity, viscosity, flash point, vapor pressure, thermal stability, electrochemical window, cell cycling data, and the ability to form solid electrolyte interphase (SEI) films. This paper presents our results on a series of chemically similar fluorinated cyclic phosphazene trimers, the FM series, which has exhibited numerous beneficial effects on battery performance, lifetimes, and safety aspects.

  6. Oxazoline-containing phosphazene derivatives. Part I: the case of hexakis(4-oxazolinophenoxy)cyclophosphazene

    Microsoft Academic Search

    Mario Gleria; Francesco Minto; Barbara Tiso; Roberta Bertani; Eugenio Tondello; Riccardo Pò; Luisa Fiocca; Emilio Lucchelli; Giorgio Giannotta; Nicoletta Cardi

    2001-01-01

    In this paper, the synthesis, characterization, and reactivity of a novel oxazoline-containing cyclophosphazene, hexakis(4-oxazolinophenoxy)cyclophosphazene, C-6-OXA, are reported. This product was synthesized by a two-step procedure that required first the preparation of 2-(4-hydroxyphenyl)-2-oxazoline and then the successive treatment of this compound with hexachlorocyclophosphazene in the presence of NaH (60% oil dispersion). The resulting C-6-OXA was eventually reacted with low-molecular-weight organic molecules,

  7. Poly[di(carboxylatophenoxy)phosphazene] is a potent adjuvant for intradermal immunization

    PubMed Central

    Andrianov, Alexander K.; DeCollibus, Daniel P.; Gillis, Helice A.; Kha, Henry H.; Marin, Alexander; Prausnitz, Mark R.; Babiuk, Lorne A.; Townsend, Hugh; Mutwiri, George

    2009-01-01

    Intradermal immunization using microfabricated needles represents a potentially powerful technology, which can enhance immune responses and provide antigen sparing. Solid vaccine formulations, which can be coated onto microneedle patches suitable for simple administration, can also potentially offer improved shelf-life. However the approach is not fully compatible with many vaccine adjuvants including alum, the most common adjuvant used in the vaccine market globally. Here, we introduce a polyphosphazene immuno adjuvant as a biologically potent and synergistic constituent of microneedle-based intradermal immunization technology. Poly[di(carboxylatophenoxy)phosphazene], PCPP, functions both as a vaccine adjuvant and as a key microfabrication material. When used as part of an intradermal delivery system for hepatitis B surface antigen, PCPP demonstrates superior activity in pigs compared to intramascular administration and significant antigen sparing potential. It also accelerates the microneedle fabrication process and reduces its dependence on the use of surfactants. In this way, PCPP-coated microneedles may enable effective intradermal vaccination from an adjuvanted patch delivery system. PMID:19864632

  8. Preparation of Coaxial-Electrospun Poly[bis(p-methylphenoxy)]phosphazene Nanofiber Membrane for Enzyme Immobilization

    PubMed Central

    Wang, Shu-Gen; Jiang, Xin; Chen, Peng-Cheng; Yu, An-Guo; Huang, Xiao-Jun

    2012-01-01

    A core/sheath nanofiber membrane with poly[bis(p-methylphenoxy)]phosphazene (PMPPh) as the sheath and easily spinnable polyacrylonitrile (PAN) as the core was prepared via a coaxial electrospinning process. Field-emission scanning electron microscopy and transmission electron microscopy were used to characterize the morphology of the nanofiber membrane. It was found that the concentration of the PAN spinning solution and the ratio of the core/sheath solution flow rates played a decisive role in the coaxial electrospinning process. In addition, the stabilized core/sheath PMPPh nanofiber membrane was investigated as a support for enzyme immobilization because of its excellent biocompatibility, high surface/volume ratio, and large porosity. Lipase from Candida rugosa was immobilized on the nanofiber membrane by adsorption. The properties of the immobilized lipase on the polyphosphazene nanofiber membrane were studied and compared with those of a PAN nanofiber membrane. The results showed that the adsorption capacity (20.4 ± 2.7 mg/g) and activity retention (63.7%) of the immobilized lipase on the polyphosphazene nanofiber membrane were higher than those on the PAN membrane. PMID:23203055

  9. Biodegradable Poly(2-Dimethylamino Ethylamino)Phosphazene for In Vivo Gene Delivery to Tumor Cells. Effect of Polymer Molecular Weight

    Microsoft Academic Search

    Holger K. de Wolf; Markus de Raad; Cor Snel; Mies J. van Steenbergen; Marcel H. A. M. Fens; Gert Storm; Wim E. Hennink

    2007-01-01

    Purpose  Previously, we have shown that complexes of plasmid DNA with the biodegradable polymer poly(2-dimethylamino ethylamino)phosphazene\\u000a (p(DMAEA)-ppz) mediated tumor selective gene expression after intravenous administration in mice. In this study, we investigated\\u000a the effect of p(DMAEA)-ppz molecular weight on both in vitro and in vivo tumor transfection, as well as on complex induced toxicity.\\u000a \\u000a \\u000a \\u000a Materials and Methods  p(DMAEA)-ppz with a broad molar

  10. In vivo tumor transfection mediated by polyplexes based on biodegradable poly(DMAEA)-phosphazene.

    PubMed

    de Wolf, Holger K; Luten, Jordy; Snel, Cor J; Oussoren, Christien; Hennink, Wim E; Storm, Gert

    2005-12-01

    In recent years, increasing interest is being paid to the design of transfectants based on non-toxic and biodegradable polymers for gene therapy purposes. We recently reported on a novel, biodegradable polymer, poly(2-dimethylamino ethylamino)phosphazene (p(DMAEA)-ppz) for use in non-viral gene delivery. In this study, the biodistribution and in vivo transfection efficiency of polyplexes composed of plasmid DNA and p(DMAEA)-ppz were investigated after intravenous administration in tumor bearing mice. Data were compared with those of polyplexes based on the non-biodegradable polyethylenimine (PEI 22kDa). Both polyplex systems were rapidly cleared from the circulation (<7% ID, at 60 min after administration) and showed considerable disposition in the liver and the lung, all in line with earlier work on cationic polyplex systems. The lung disposition is attributed to aggregates formed by interaction of the polyplexes with blood constituents. Redistribution of the polyplexes from the lung was observed for both polyplex formulations. Importantly, both polyplex systems showed a substantial tumor accumulation of 5% and 8% ID/g for p(DMAEA)-ppz and PEI22 polyplexes, respectively, at 240 min after administration. The tumor disposition of the p(DMAEA)-ppz and PEI22 polyplexes was associated with considerable expression levels of the reporter gene. In contrast to PEI22 polyplexes, p(DMAEA)-ppz polyplexes did not display substantial gene expression in the lung or other organs (organ gene expression<1/100 of tumor gene expression). The observed preferential tumor gene expression mediated by the p(DMAEA)-ppz polyplexes enables the application of this polymer to deliver therapeutic genes to tumors. PMID:16039747

  11. Plasma surface functionalization of poly[bis(2,2,2-trifluoroethoxy)phosphazene] films and nanofibers.

    PubMed

    Allcock, Harry R; Steely, Lee B; Kim, Seong H; Kim, Jeong H; Kang, Bang-Kwon

    2007-07-17

    Polyphosphazenes are a class of hybrid organic-inorganic macromolecules with high thermo-oxidative stability and good solubility in many solvents. Fluoroalkoxy phosphazene polymers also have high surface hydrophobicity. A method is described to tune this surface property while maintaining the advantageous bulk materials characteristics. The polyphosphazene single-substituent polymer, poly[bis(2,2,2-trifluoroethoxy)phosphazene], with flat film, fiber mat, or bead mat morphology was surface functionalized using an atmospheric plasma treatment with oxygen, nitrogen, methane, or tetrafluoromethane/hydrogen gases. Surface chemistry changes were detected by static water contact angle (WCA) measurements as well as X-ray photon spectroscopy (XPS). It was found that changes in the WCA of as much as 150 degrees occurred, accompanied by shifts in the ratio of elements on the polymer surface as detected by XPS. Overall this plasma technique provides a convenient method for the generation of specific surface characteristics while maintaining the hydrophobicity of the bulk material. PMID:17590030

  12. Novel spirocyclic phosphazene-based epoxy resin for halogen-free fire resistance: synthesis, curing behaviors, and flammability characteristics.

    PubMed

    Sun, Jian; Wang, Xiaodong; Wu, Dezhen

    2012-08-01

    A novel halogen-free fire resistant epoxy resin with pendent spiro-cyclotriphosphazene groups was designed and synthesized via a three-step synthetic pathway. The chemical structures and compositions of spiro-cyclotriphosphazene precursors and final product were confirmed by (1)H, (13)C, and (31)P NMR spectroscopy, mass spectroscopy, elemental analysis, and Fourier transform infrared spectroscopy. The thermal curing behaviors of the synthesized epoxy resin with 4,4'-diamino-diphenylmethane, 4,4'-diamino-diphenyl sulfone, and novolac as hardeners were investigated by differential scanning calorimetry (DSC), and the curing kinetics were also studied under a nonisothermal condition. The evaluation of the thermal properties demonstrated that these thermosets achieved a good thermal resistance due to their high glass transition temperatures more than 150 °C, and also gained high thermal stabilities with high char yields. The flammability characteristics of the spirocyclic phosphazene-based epoxy thermosets cured with these three hardeners were investigated on the basis of the results obtained from the limiting oxygen index (LOI) and UL-94 vertical burning experiments as well as the analysis of the residual chars collected from the vertical burning tests. The high LOI values and UL-94 V-0 classification of these epoxy thermosets indicated that the incorporation of phosphazene rings into the backbone chain imparts nonflammability to the epoxy resin owing to the unique combination of phosphorus and nitrogen following by a synergistic effect on flame retardancy. The epoxy resin obtained in this study is a green functional polymer and will become a potential candidate for fire- and heat-resistant applications in electronic and microelectronic fields with more safety and excellent performance. PMID:22833687

  13. Oxazoline-Containing Phosphazene Derivatives Part II Polymer Preparation and Modification Through the Reactivity of Oxazoline Moieties on Cyclophosphazenes

    Microsoft Academic Search

    Roberta Bertani; Luca Fambri; Luisa Fiocca; Giorgio Giannotta; Mario Gleria; Riccardo Pò; Sonia Scalabrin; Eugenio Tondello; Alfonso Venzo

    2007-01-01

       In this paper we report the synthesis, the characterization and the practical utilization of two cyclophosphazenes (CPs) substituted\\u000a with two (C-2-OXA) and six (C-6-OXA) 2-(4-hydroxyphenyl)-2-oxazoline groups, respectively. The first chemical observation on these substrates is that the reactivity\\u000a of the oxazoline groups is preserved even when these products are attached to the phosphorus atoms of a cyclophosphazene ring.\\u000a By reaction

  14. Derivate

    NSDL National Science Digital Library

    2011-03-16

    In this activity, students input functions in order to calculate the derivative and tangent line of that function. This activity allows students to explore tangent lines of various functions. This activity includes supplemental materials, including background information about the topics covered, a description of how to use the application, and exploration questions for use with the java applet.

  15. Biodegradable Poly(2-Dimethylamino Ethylamino)Phosphazene for In Vivo Gene Delivery to Tumor Cells. Effect of Polymer Molecular Weight

    PubMed Central

    de Wolf, Holger K.; de Raad, Markus; Snel, Cor; van Steenbergen, Mies J.; Fens, Marcel H. A. M.; Storm, Gert

    2007-01-01

    Purpose Previously, we have shown that complexes of plasmid DNA with the biodegradable polymer poly(2-dimethylamino ethylamino)phosphazene (p(DMAEA)-ppz) mediated tumor selective gene expression after intravenous administration in mice. In this study, we investigated the effect of p(DMAEA)-ppz molecular weight on both in vitro and in vivo tumor transfection, as well as on complex induced toxicity. Materials and Methods p(DMAEA)-ppz with a broad molar mass distribution was fractionated by preparative size exclusion chromatography. Polyplexes consisting of plasmid DNA and the collected polymer fractions were tested for biophysical properties, (cyto)toxicity and transfection activity. Results Four p(DMAEA)-ppz fractions were collected with weight average molecular weights ranging from 130 to 950 kDa, and with narrow molecular mass distributions (Mw/Mn from 1.1 to 1.3). At polymer-to-DNA (N/P) ratios above 6, polyplexes based on these polymers were all positively charged (zeta potential 25–29 mV), and had a size of 80–90 nm. The in vitro cytotoxicity of the polyplexes positively correlated with polymer molecular weight. The in vitro transfection activity of the different polyplexes depended on their N/P ratio, and was affected by the degree of cytotoxicity, as well as the colloidal stability of the different polyplexes. Intravenous administration of polyplexes based on the high molecular weight polymers led to apparent toxicity, as a result of polyplex-induced erythrocyte aggregation. On the other hand, administration of polyplexes based on low molecular weight p(DMAEA)-ppz’s (Mw 130 kDa) did not show signs of toxicity and resulted in tumor selective gene expression. Conclusion Polymer molecular weight fractionation enabled us to optimize the transfection efficiency/toxicity ratio of p(DMAEA)-ppz polyplexes for in vitro and in vivo tumor transfection. PMID:17435970

  16. Galactosylated poly(2-(2-aminoethyoxy)ethoxy)phosphazene/DNA complex nanoparticles: in vitro and in vivo evaluation for gene delivery.

    PubMed

    Yang, Yongxin; Zhang, Zhiwen; Chen, Lingli; Gu, Wangwen; Li, Yaping

    2010-04-12

    To achieve efficient gene delivery to the tumor after intravenous administration, biodegradable poly(2-(2-aminoethyoxy)ethoxy)phosphazene (PAEP) was modified by lactobionic acid, bearing a galactose group as a targeting ligand. Galactosylated poly(2-(2-aminoethyoxy)ethoxy)phosphazene (Gal-PAEP) with 4.9% substitution degree of galactose could condense pDNA into nanoparticles with a size around 130 nm at the polymer/DNA ratio (N/P) of 2-40. For BEL-7402 cells, the in vitro transfection efficiency of gal-PAEP/DNA complex nanoparticles (gal-PACNs) was much higher than that of the PAEP/DNA complex nanoparticles (PACNs). MTT assay indicated that the cytotoxicity of PACNs significantly decreased after conjugating with the galactose moiety. Gal-PACNs displayed the selective gene expression in the tumor and liver with relatively low gene expression in the lung or other organs compared with PACNs. These results suggested that gal-PACNs could be a promising targeting gene carrier to deliver a therapeutic gene in future. PMID:20302354

  17. Section IV.D.3 for DOE 2013 Annual Report: Novel Phosphazene-based Compounds to Enhance Safety and Stability of Cell Chemistries for High Voltage Applications (INL)

    SciTech Connect

    Kevin L. Gering; Mason K. Harrup; Eric J. Dufek; Sergiy V. Sazhin; Harry W. Rollins; David K. Jamison; Fred F. Stewart; John Burba

    2013-09-01

    Electrolytes play a central role in performance and aging in most electrochemical systems. As automotive and grid applications place a higher reliance on electrochemical stored energy, it becomes more urgent to have electrolyte components that enable optimal battery performance while promoting battery safety and longevity. Safety remains a foremost concern for widespread utilization of Li-ion technology in electric-drive vehicles, especially as the focus turns to higher voltage systems (5V). This work capitalizes on the long established INL expertise regarding phosphazene chemistry, aimed at battery-viable compounds for electrolytes and electrodes that are highly tolerant to abusive conditions. This report showcases our 2013 work for the DOE applied battery research (ABR) program, wherein testing results are summarized for INL electrolytes and alternative anode materials.

  18. Folate-PEG modified poly(2-(2-aminoethoxy)ethoxy)phosphazene/DNA nanoparticles for gene delivery: synthesis, preparation and in vitro transfection efficiency.

    PubMed

    Zhang, Pengcheng; Zhang, Zhiwen; Yang, Yongxin; Li, Yaping

    2010-06-15

    Target-specific technique can significantly enhance the efficacy of gene delivery system which was limited by many cellular barriers. In this work, a new folate-PEG modified poly(2-(2-aminoethoxy)ethoxy)phosphazene (PAEP), namely, folate-PEG-PAEP was synthesized as a folate receptor (FR) targeted carrier, and the cytotoxicity, transfection efficiency, cellular uptake and intracellular trafficking of folate-PEG-PAEP/DNA nanoparticles (FPPN) were investigated. Compared with the PAEP/DNA nanoparticles (PN), the cytotoxicity of FPPN decreased significantly at high dose. FPPN showed much higher transfection efficiency (15.85+/-1.23%) compared with PN (6.71+/-0.42%) in FR overexpressing Hela cells, but no significant difference was observed in CHO-k1 cells lacking FR. The transfection activity of FPPN could be reversed in the presence of 1.0mM free folic acid in Hela cells. The cellular uptake of FPPN was 37.38% higher than that of PN in Hela cells. These results indicated that FPPN could be a potential targeted gene delivery system. PMID:20298769

  19. Miscibility and in vitro osteocompatibility of biodegradable blends of poly[(ethyl alanato) (p-phenyl phenoxy) phosphazene] and poly(lactic acid-glycolic acid).

    PubMed

    Deng, Meng; Nair, Lakshmi S; Nukavarapu, Syam P; Kumbar, Sangamesh G; Jiang, Tao; Krogman, Nicholas R; Singh, Anurima; Allcock, Harry R; Laurencin, Cato T

    2008-01-01

    Previously we demonstrated the ability of ethyl glycinato substituted polyphosphazenes to neutralize the acidic degradation products and control the degradation rate of poly(lactic acid-glycolic acid) (PLAGA) by blending. In this study, blends of high strength poly[(50% ethyl alanato) (50% p-phenyl phenoxy) phosphazene] (PNEA(50)PhPh(50)) and 85:15 PLAGA were prepared using a mutual solvent approach. Three different solvents, methylene chloride (MC), chloroform (CF) and tetrahydrofuran (THF) were studied to investigate solvent effects on blend miscibility. Three different blends were then fabricated at various weight ratios namely 25:75 (BLEND25), 50:50 (BLEND50), and 75:25 (BLEND75) using THF as the mutual solvent. The miscibility of the blends was evaluated by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FTIR). Among these, BLEND25 was miscible while BLEND50 and BLEND75 were partially miscible. Furthermore, BLEND25 formed apatite layers on its surface as evidenced in a biomimetic study performed. These novel blends showed cell adhesion and proliferation comparable to PLAGA. However, the PNEA(50)PhPh(50) component in the blends was able to increase the phenotypic expression and mineralized matrix synthesis of the primary rat osteoblasts (PRO) in vitro. Blends of high strength PNEA(50)PhPh(50) and 85:15 PLAGA are promising biomaterials for a variety of musculoskeletal applications. PMID:17942150

  20. Phosphorus nitrogen compounds: Novel fully substituted spiro-cyclophosphazenic lariat (PNP-pivot) ether derivatives. Structures of 4,4,6,6-tetrapyrrolidino-2,2-[3-oxa-1,5-pentane dioxy bis(2-phenylamino)]cyclo-2lambda5,4lambda5,6lambda5-triphosphazene and 4,4,6,6-tetrapyrrolidino-2,2-[1,2-xylylene dioxy bis(2-phenylamino)]cyclo-2lambda5,4lambda5,6lambda5-triphosphazene. Part XI

    Microsoft Academic Search

    Selen Bilge; Bilgehan Özgüç; Serap Safran; Semsay Demiriz; Hikmet Isler; Mustafa Hayvali; Zeynel Kiliç; Tuncer Hökelek

    2005-01-01

    The condensation reaction of partly substituted spiro-cyclophosphazenic lariat (PNP-pivot) ethers, N3P3[(o-NHPhO)2R]Cl4 (5 8), where R= CH2CH2 , CH2CH2CH2 , CH2CH2OCH2CH2 , and CH2PhCH2 , with pyrrolidine have been afforded fully substituted pyrrolidino phosphazene derivatives (9 12) (Scheme). There are the first examples of the spiro-cyclophosphazenic lariat (PNP-pivot) ether ligands with N2Ox-(x=2, 3) donor type containing 11 14 membered macrocycles. The

  1. Phosphorus–nitrogen compounds: Novel fully substituted spiro-cyclophosphazenic lariat (PNP-pivot) ether derivatives. Structures of 4,4,6,6-tetrapyrrolidino-2,2-[3-oxa-1,5-pentane dioxy bis(2-phenylamino)]cyclo-2 ? 5,4 ? 5,6 ? 5-triphosphazene and 4,4,6,6-tetrapyrrolidino-2,2-[1,2-xylylene dioxy bis(2-phenylamino)]cyclo-2 ? 5,4 ? 5,6 ? 5-triphosphazene. Part XI

    Microsoft Academic Search

    Selen Bilge; Bilgehan Özgüç; Serap Safran; ?emsay Demiriz; Hikmet ??ler; Mustafa Hayval?; Zeynel K?l?ç; Tuncer Hökelek

    2005-01-01

    The condensation reaction of partly substituted spiro-cyclophosphazenic lariat (PNP-pivot) ethers, N3P3[(o-NHPhO)2R]Cl4 (5–8), where R=–CH2CH2–, –CH2CH2CH2–, –CH2CH2OCH2CH2–, and –CH2PhCH2–, with pyrrolidine have been afforded fully substituted pyrrolidino phosphazene derivatives (9–12) (Scheme). There are the first examples of the spiro-cyclophosphazenic lariat (PNP-pivot) ether ligands with N2Ox-(x=2, 3) donor type containing 11–14 membered macrocycles. The solid state structures of (11 and 12) have

  2. Polymer electrolytes derived from polynorbornenes with pendent cyclophosphazenes: poly(ethylene glycol) methyl ether (PEGME) derivatives

    Microsoft Academic Search

    Harry R Allcock; Walter R Laredo; Robert V Morford

    2001-01-01

    A novel elastomeric polymer electrolyte was developed by the linkage of poly(ethylene glycol) methyl ether (PEGME) side chains and norbornene-based units to a cyclotriphosphazene ring, followed by polymerization of the norbornene units by ring-opening metathesis polymerization (ROMP). This yielded an organic polymer backbone with ion co-ordinative cyclic phosphazene side groups. Adjustment of the norbornene content in the starting monomer allowed

  3. Derivatives Page

    NSDL National Science Digital Library

    Derivatives are financial securities whose value is derived from another "underlying" financial security. Options, futures, swaps, swaptions, and structured notes are all examples of derivative securities. Derivatives can be used in hedging, protecting against financial risk, or can be used to speculate on the movement of commodity or security prices, interest rates, or the levels of financial indices. The valuation of derivatives makes use of the statistical mathematics of uncertainty. With links to related articles. See also Derivatives Concepts A-Z, glossary of derivatives-related terminology designed to make the other articles in the Financial Pipeline's Derivatives section easier to understand.

  4. Complex derivatives

    NASA Astrophysics Data System (ADS)

    Battiston, Stefano; Caldarelli, Guido; Georg, Co-Pierre; May, Robert; Stiglitz, Joseph

    2013-03-01

    The intrinsic complexity of the financial derivatives market has emerged as both an incentive to engage in it, and a key source of its inherent instability. Regulators now faced with the challenge of taming this beast may find inspiration in the budding science of complex systems.

  5. Synthesis and thermal stability of carborane containing phosphazenes

    NASA Technical Reports Server (NTRS)

    Fewell, L. L.; Basi, R. J.; Parker, J. A.

    1983-01-01

    Carborane substituted polyphosphazenes were prepared by the thermal polymerization of phenyl-carboranyl penta chlorocyclotriphosphazene. Successive isothermal vacuum pyrolyses were conducted on the polymer and examined for structural changes by infrared spectroscopy. The degradation products were ascertained by gas chromatography-mass spectrometric analysis. It was found that the presence of the carborane group improves the thermal stability of the polymer by retarding the ring chain equilibrium processes of decomposition.

  6. Thermal degradation chemistry of poly[bis(phenoxy)phosphazene

    E-print Network

    Maynard, Shawn Joseph

    1989-01-01

    , '400, and 440 'C . 22 40-MHz P MAS NMR spectra of trimer samples isothermally degraded at 360, 400, and 440 C . . . 25 81-MHz P solution-state NMR spectra of tetramer samples isothermally degraded at 280, 320, 360, and 400 oC 26 40-MHz P MAS NMR... Figure LIST OF FIGURES (continued) Page 13 14 81-MHz P solution-state NMR spectra of PBPP-O. OO samples isothermally degraded at 280, 320, 360, and 440 C . 40-MHz P MAS NMR spectra of PBPP-O. OO samples isothermally degraded at 320, 360, 400...

  7. Investigation of phosphazene additive for magnetic recording lubrication

    Microsoft Academic Search

    C. Mathew Mate; Paul H. Kasai; George W. Tyndall; Charles H. Lee; Vedantham Raman; Daryl J. Pocker; Robert J. Waltman

    1998-01-01

    The addition of X-IP to the Fomblin Z-Dol disk lubricant is found to improve the contact start-stop (CSS) durability of hydrogenated carbon overcoated disks. Two-angle electron spectroscopy for chemical analysis (ESCA), contact angle measurements, spin-off measurements, and degradation studies on powdered AlCl3 and Al2O3 are used to show that X-IP improves lubrication by perfluoropolyethers on magnetic disks by chemically interacting

  8. Weather Derivative Valuation

    NASA Astrophysics Data System (ADS)

    Jewson, Stephen; Brix, Anders

    2005-04-01

    Weather Derivative Valuation is the first book to cover all the meteorological, statistical, financial and mathematical issues that arise in the pricing and risk management of weather derivatives. There are chapters on meteorological data and data cleaning, the modelling and pricing of single weather derivatives, the modelling and valuation of portfolios, the use of weather and seasonal forecasts in the pricing of weather derivatives, arbitrage pricing for weather derivatives, risk management, and the modelling of temperature, wind and precipitation. Specific issues covered in detail include the analysis of uncertainty in weather derivative pricing, time-series modelling of daily temperatures, the creation and use of probabilistic meteorological forecasts and the derivation of the weather derivative version of the Black-Scholes equation of mathematical finance. Written by consultants who work within the weather derivative industry, this book is packed with practical information and theoretical insight into the world of weather derivative pricing.

  9. Derivations of quasi *-algebras

    E-print Network

    F. Bagarello; A. Inoue; C. Trapani

    2009-03-31

    The spatiality of derivations of quasi *-algebras is investigated by means of representation theory. Moreover, in view of physical applications, the spatiality of the limit of a family of spatial derivations is considered.

  10. Derivation of Characteristic Formulae

    Microsoft Academic Search

    Markus Müller-Olm

    1998-01-01

    This paper shows how modal mu-calculus formulae characterizing finite-state processes up to strong or weak bisimulation can be derived directly from the well-known greatest fixpoint characterizations of the bisimulation relations. Our derivation simplifies earlier proofs for the strong bisimulation case and, by virtue of derivation, immediately generalizes to various other bisimulation-like relations, in particular weak bisimulation.

  11. Endohedral Metallofullerene Derivatives

    NASA Technical Reports Server (NTRS)

    Dorn, Harry C. (Inventor); Iezzi, Erick B. (Inventor); Duchamp, James (Inventor)

    2008-01-01

    Trimetallic nitride endohedral metallofullerene derivatives and their preparation are described. The trimetallic nitride endohedral metallofullerene derivatives have the general formula A(sub 3-n)X(sub n)@C(sub m)(R) where n ranges from 0 to 3, A and X may be trivalent metals and may be either rare earth metal or group IIIB metals, m is between about 60 and about 200, and R is preferably an organic group. Derivatives where the R group forms cyclized derivatives with the fullerene cage are also described.

  12. Partial Derivative Visualization Gallery

    NSDL National Science Digital Library

    Roberts, Lila F.

    2004-11-11

    This resource is a small gallery of demos for illustrating partial derivatives geometrically. These animations can be used by instructors in a classroom setting or by students to aid in acquiring a visualization background for partial derivatives. Two file formats, gif and QuickTime files are used for the animations which can be downloaded.

  13. Derivative Matching Game

    NSDL National Science Digital Library

    Once again, the Mathematical Association of America has struck instructional gold with this latest gem from their online collection of resources for mathematics educators. Created by Barbara Margolius, this derivative matching game presents users with a game board showing graphs of functions on cards. Essentially, the goal of the game is to match the functions with their derivatives. Visitors can begin by reading an overview of the game, along with some brief instructions, and then they should dive right in. The game can also be customized to match functions with just first derivatives or both first and second derivatives. Mathematics educators will have a lot of fun with this one, and even the mathematically uncertain can be drawn into the fold with this easy to use resource.

  14. Derivative actions in China 

    E-print Network

    Lin, Shaowei

    2014-07-02

    The enactment of derivative action was expected to be actively used by shareholders to protect their interests. In fact, it turned out that this reform effort seemed futile as the right to engage in such actions was ...

  15. Definitions Derived from Neutrosophics

    E-print Network

    Florentin Smarandache

    2003-01-28

    Thirty-three new definitions are presented, derived from neutrosophic set, neutrosophic probability, neutrosophic statistics, and neutrosophic logic. Each one is independent, short, with references and cross references like in a dictionary style.

  16. Definitions Derived from Neutrosophics

    Microsoft Academic Search

    Florentin Smarandache

    2003-01-01

    Thirty-three new definitions are presented, derived from neutrosophic set, neutrosophic probability, neutrosophic statistics, and neutrosophic logic. Each one is independent, short, with references and cross references like in a dictionary style.

  17. Synthesis of phenoxatellurine derivatives

    SciTech Connect

    Maksimenko, A.A.; Rivkin, B.B.; Sadekov, I.D.; Minkin, V.I.

    1985-12-01

    The reaction of dimedon enol acetate with tellurium tetrachloride gives derivatives of octahydrophenoxatellurine. The reaction of cyclohexanone enol acetate and methyl ethyl ketone with tellurium tetrachloride or aryltellurium trichloride gives the respective organotellurium trichloride and diorganotellurium dichloride.

  18. Derived Hall Algebras

    Microsoft Academic Search

    Bertrand Toen

    2005-01-01

    The purpose of this work is to define a derived Hall algebra $\\\\mathcal{DH}(T)$, associated to any dg-category $T$ (under some finiteness conditions). Our main theorem states that $\\\\mathcal{DH}(T)$ is associative and unital. It is shown that $\\\\mathcal{DH}(T)$ contains the usual Hall algebra $\\\\mathcal{H}(T)$ when $T$ is an abelian category. We will also prove an explicit formula for the derived Hall

  19. Semisynthetic Derivatives of Epothilones

    NASA Astrophysics Data System (ADS)

    Altmann, Karl-Heinz

    Semisynthetic derivatives of natural products traditionally occupy a prominent space in natural-product-based drug discovery (1, 2). As many biologically active natural products exhibit a high degree of structural complexity (3), the chemical derivatization of material isolated from natural sources often represents the only feasible means (or at least the only economically viable approach) to explore structure-activity-relationships (SAR) and to produce analogs with more favorable pharmacokinetic and pharmacological properties than the natural product lead. Examples of clinically important drugs that are semisynthetic derivatives of natural products exist in virtually all disease areas (1, 2); in the treatment of cancer this includes compounds such as etoposide or teniposide (derived from podophyllotoxin) (4-6), irinotecan and topotecan (derived from camptothecin) (7-9), or docetaxel (derived from 10-deacetylbaccatin III) (10, 11). Even for taxol (11), which is a natural product (12), the sustained supply of sufficient quantities of material for widespread clinical use could only be secured through the development of a semisynthetic production process from another natural product, namely, 10-deacetylbaccatin III (13). In light of these facts, it is not surprising that semisynthesis approaches have also featured prominently in the elucidation of the SAR for epothilones and in the discovery of a number of clinical development candidates.

  20. Derivative-Free Optimization

    Microsoft Academic Search

    Oliver Kramer; David Ciaurri; Slawomir Koziel

    \\u000a In many engineering applications it is common to find optimization problems where the cost function and\\/or constraints require\\u000a complex simulations. Though it is often, but not always, theoretically possible in these cases to extract derivative information\\u000a efficiently, the associated implementation procedures are typically non-trivial and time-consuming (e.g., adjoint-based methodologies).\\u000a Derivative-free (non-invasive, black-box) optimization has lately received considerable attention within the

  1. Fractional Derivative Cosmology

    E-print Network

    Mark D. Roberts

    2009-09-07

    The degree by which a function can be differentiated need not be restricted to integer values. Usually most of the field equations of physics are taken to be second order, curiosity asks what happens if this is only approximately the case and the field equations are nearly second order. For Robertson-Walker cosmology there is a simple fractional modification of the Friedman and conservation equations. In general fractional gravitational equations similar to Einstein's are hard to define as this requires fractional derivative geometry. What fractional derivative geometry might entail is briefly looked at and it turns out that even asking very simple questions in two dimensions leads to ambiguous or intractable results. A two dimensional line element which depends on the Gamma-function is looked at.

  2. Derived Hall algebras

    Microsoft Academic Search

    Bertrand Toën

    2006-01-01

    The purpose of this work is to define a derived Hall algebra $\\\\mathcal{DH}(T)$ , associated to any differential graded (DG) category $T$ (under some finiteness conditions), generalizing the Hall algebra of an abelian category. Our main theorem states that $\\\\mathcal{DH}(T)$ is associative and unital. When the associated triangulated category $[T]$ is endowed with a t-structure with heart $\\\\mathcal{A}$ , it

  3. Derived Equivalences by Quantization

    Microsoft Academic Search

    Dmitry Kaledin

    2008-01-01

    We assume given a smooth symplectic (in the algebraic sense) resolution $X$\\u000aof an affine algebraic variety $Y$, and we prove that, possibly after replacing\\u000a$Y$ with an etale neighborhood of a point, the derived category of coherent\\u000asheaves on $X$ is equivalent to the dervied category of finitely generated left\\u000amodules over a non-commutative algebra $R$, a non-commutative resolution

  4. Lanolin and its derivatives

    Microsoft Academic Search

    Mitchell L. Schlossman; Justin P. McCarthy

    1978-01-01

    Lanolin, which is extensively used in pharmaceuticals and cosmetics, is generally considered to consist of a mixture of naturally\\u000a formed esters derived from higher alcohols and higher fatty acids. This paper encompasses the chemical description of lanolin;\\u000a the composition of its esters, acids, and alcohols; the chemical and physical modifications of lanolin; the refining of lanolin;\\u000a and some of its

  5. Deriving Darcy's Law

    NSDL National Science Digital Library

    Karen Salvage

    This exercise begins with a demonstration of fluid flow through porous sediment using a constant head permeameter, with the students conducting the experiment and collecting the data. The demo is followed by a Think-Pair-Share exercise in which the question is posed to the class: "What could we change in order to increase flow through the system?" The class then works through their brainstormed list of ideas, discussing each and evaluating whether it is correct or a misconception. The students derive Darcy's Law qualitatively, based upon the results of the Think-Pair-Share exercise and discussions.

  6. Space Derived Air Monitor

    NASA Technical Reports Server (NTRS)

    1983-01-01

    COPAMS, Commonwealth of Pennsylvania Air Monitoring System, derives from technology involved in building unmanned spacecraft. The Nimbus spacecraft carried experimental sensors to measure temperature, pressure, ozone, and water vapor, and instruments for studying solar radiation and telemetry. The process which relayed these findings to Earth formed the basis for COPAMS. The COPAMS system consists of data acquisition units which measure and record pollution level, and sense wind speed and direction, etc. The findings are relayed to a central station where the information is computerized. The system is automatic and supplemented by PAQSS, PA Air Quality Surveillance System.

  7. Adipose-derived cells.

    PubMed

    Meliga, Emanuele; Strem, Brian M; Duckers, H J; Serruys, Patrick W

    2007-01-01

    Heart failure is by far the most common cause of hospitalization in Western countries, with onerous economic consequences. Cell therapy holds great promise for use in tissue regeneration and is increasingly used in an effort to improve outcomes in cardiac disease. Recently it has been shown that adipose tissue, in addition to committed adipogenic, endothelial progenitor cells and pluripotent vascular progenitor cells, also contains multipotent cell types (adipose-derived stem cells, ADSCs) that, in cell culture conditions, have shown to have an impressive developmental plasticity including the ability to undergo multilineage differentiation and self-renewal. ADSCs express multiple CD marker antigens similar to those observed on MSCs and are also capable of secreting a large number of angiogenesis-related cytokines, including vascular endothelial growth factor, granulocyte/macrophage colony stimulating factor, stromal-derived factor-1alpha, and hepatocyte growth factor. Adipose tissue can be harvested in large quantities with minimal morbidity in several regions of the body and, on average, 100 ml of human adipose tissue yields about 1 x 10(6) stem cells. Studies conducted in porcine AMI models have shown a significant LV functional improvement, with no report of any potentially fatal arrhythmias. The APOLLO trial, a prospective, double blind, randomized, placebo-controlled trial currently in the recruiting phase, is a "first-in-man" study that explores the safety and feasibility of ADSC transplantation in patients with acute MI. PMID:18293895

  8. 6-Bromocholesterol derivatives

    SciTech Connect

    Flanagan, R.J.

    1984-02-07

    Novel 6-bromo derivatives of cholesterol have the formula 3-(R-O-),6-BR,17-((H3C-)2-HC-H2C-H2C-H2C-HC(-CH3)-)-ESTR-5-ENE Such compounds are prepared from the known 6-iodocholesterol by treatment with cuprous bromide. These compounds, labelled with radioisotopes of Br-82 or Br-77, are localized in the adrenal, mammary and ovary tissue of female mammals and in the adrenal or prostate tissue of males when administered to such individuals. This provides a method for imaging adrenal, ovary or prostate tissue which is superior to use of the prior art 6-iodo-cholesterol.

  9. Deriving Category Theory Type Theory

    E-print Network

    Crole, Roy L.

    Deriving Category Theory from Type Theory Roy L. Crole March 1993 Abstract This work expounds for example [BW90] or [Pie91]. Before we embark on our derivation of a category, let us review the traditional

  10. Phosphorus-nitrogen compounds: part 30. Syntheses and structural investigations, antimicrobial and cytotoxic activities and DNA interactions of vanillinato-substituted NN or NO spirocyclic monoferrocenyl cyclotriphosphazenes.

    PubMed

    Tümer, Yasemin; Koç, L Yasemin; Asmafiliz, Nuran; K?l?ç, Zeynel; Hökelek, Tuncer; Soltanzade, Hossien; Aç?k, Leyla; Yola, Mehmet Lütfi; Solak, Ali Osman

    2015-01-01

    The gradual Cl replacement reactions of NN (1-3) or NO spirocyclic monoferrocenyl cyclotriphosphazenes (4 and 5) with the potassium salt of 4-hydroxy-3-methoxybenzaldehyde (potassium vanillinate) resulted in the mono (1a-5a), geminal (gem-1b-5b), non-geminal (cis-5b and trans -1b-4b), tri (1c, 3c-5c) and tetra-vanillinato-substituted phosphazenes (1d-5d). All the phosphazene derivatives have stereogenic P-center(s), except tetra-substituted ones. The vanillinatophosphazenes have reversible voltammograms with one-electron anodic and cathodic peaks which are attributed to ferrocenyl redox probe. The structures of the new phosphazene compounds were determined by FTIR, MS, (1)H, (13)C{(1)H} and (31)P{(1)H} NMR spectral data. The solid-state structure of cis -5b was examined by single-crystal X-ray diffraction techniques. In addition, the compounds were tested in HeLa cancer cell lines using MTT assay. The 12 phosphazene derivatives were screened for antimicrobial activity, and 3c was very effective against S. aureus even at 4.88 µM concentration, taking into account the MIC values. Besides, interactions between the phosphazenes and pBR322 plasmid DNA were also investigated. PMID:25491284

  11. Biomolecule derived nanostructured arrays

    NASA Astrophysics Data System (ADS)

    Yuan, Zhen

    During the last decade, intensive research have been reported on biomimetic approaches towards achieving mono-dispersed nanoparticles, and building self-assembled system out of those (organizing nanoparticles). However the development of this research avenue is being hindered by the limited knowledge and very few practical, efficient, cost-effective approaches for implementation of the bio-derived arrays into engineering practice. The objective of this work is to biomimeticaly form nanocomposite materials using a simple, rapid, inexpensive, scalable approach, which is general enough and not limited to colloidal particle self-assembly. Throughout the studies, we have developed a universally applicable process, which is to fabricate macro-biomolecular arrays on solid substrates based on the convective self-assembly of colloidal particles. We have demonstrated that protein (ferritin) and virus (phage) arrays were directly deposited onto solid substrates such as glass, silicon wafer, and gold substrate in closed or near closed-packed order. The arrays were further incorporated into a more robust silica matrix, in such that strengthens the thermal stability and provides porous accessibility. After treatment in controlled pyrolysis, the organic protein shell was removed, left mono-dispersed iron-oxide nanoparticles intact on the substrate or in the silica matrix. Both iron-oxide nanoparticles arrays with or without silica matrix have been further characterized to possess superferromagnetic properties at low temperature (15 K), same as that in bulk material. Initial work on protein patterning, through combining either lithography based top-down or bottom-up techniques with our novel deposition approach, was presented as well. Thin film deposition of mesoporous materials using convective self-assembly is another main part in this work. Both silica and carbon mesoporous thin films were successfully formed using the convective self-assembly horizontal-coating approach. We have shown that ultra thin mesoporous film (less than 100 nm) could be obtained through increasing the coating speed with the solution concentration remained same. Combining with lithographically patterned surface, the mesoporous thin films will be well suited for applications for bio-sensing, separations and etc. Studies were also carried out on the transport of fluid and electric current in fluidic channels with size in nanometer range; particular attention was paid on the effect of the electrolyte valence. At these dimensions new physical phenomena begin to occur because the electric double layers formed at the channel walls become comparable to the channel width and the overall wall surface to channel volume ratio increases. Numerical analysis predicts that the electrokinetic transport phenomena differ from multivalent ions to monovalent ions in the nanochannel when double layer overlap is large. This dependence affects the transport of current, fluid and dissolved analytes in a fluidic channel. The valence of the dissolved counterions determines the electric current and fluid flow in a nanochannel by shaping the electrostatic potential distribution. Our calculation shows that in absence of strong adsorption at the wall, divalent counterions lead to greater current and fluid flow than monovalent electrolyte for the same overall ionic strength. The results also indicate that control over the transport processes in fluidic nanochannels can be accomplished through properly selecting and combining electrolytes.

  12. Programmed Derivations of Relational Structures

    Microsoft Academic Search

    Andrea Maggiolo-schettini; Józef Winkowski

    1990-01-01

    Derivations of relational structures by applying productions are considered. The corresponding concepts are taken from the existing algebraic (category theory) approach to transformations of relational structures. An idea of programs for defining sets of derivations is introduced. A number of programming constructs is introduced to specify applications of productions in a controlled way. These constructs are given together with two

  13. Pseudorandom Financial Derivatives [Extended Abstract

    E-print Network

    Zuckerman, David

    in the recent financial crisis. A derivative is a financial product whose value is a function of one or more un computational assumption. In- deed, in the recent financial crisis, it appears that sellers did pack lemonsPseudorandom Financial Derivatives [Extended Abstract] David Zuckerman Department of Computer

  14. Inflation Derivatives L. P. Hughston

    E-print Network

    Macrina, Andrea

    Inflation Derivatives L. P. Hughston Department of Mathematics King's College London The Strand (0)207 848 2855 Abstract. A general theory for the pricing and hedging of inflation The purpose of this note is to outline briefly a general model of inflation and inflation-linked derivatives

  15. Elementary derivation of Kepler's laws

    Microsoft Academic Search

    Erich Vogt

    1996-01-01

    A simple derivation of all three so-called Kepler laws is presented in which the orbits, bound and unbound, follow directly and immediately from conservation of energy and angular momentum. The intent is to make this crowning achievement of Newtonian mechanics easily accessible to students in introductory physics courses. The method is also extended to simplify the derivation of the Rutherford

  16. The Amazingly Versatile Titanocene Derivatives

    NASA Astrophysics Data System (ADS)

    Bowman, Donald C.

    2006-05-01

    Derivatives of titanocene are remarkably versatile in their chemical applications. This article presents a brief review of the derivatives' uses in the fields of polymers, medical oncology, and organic synthesis. While exhaustive studies exist emphasizing a single field of application, this article shows the breadth of application existing with these complexes.

  17. Derivations and skew derivations of the Grassmann algebras

    E-print Network

    Bavula, V V

    2007-01-01

    Surprisingly, skew derivations rather than ordinary derivations are more basic (important) object in study of the Grassmann algebras. Let $\\L_n = K\\lfloor x_1, ..., x_n\\rfloor$ be the Grassmann algebra over a commutative ring $K$ with ${1/2}\\in K$, and $\\d$ be a skew $K$-derivation of $\\L_n$. It is proved that $\\d$ is a unique sum $\\d = \\d^{ev} +\\d^{od}$ of an even and odd skew derivation. Explicit formulae are given for $\\d^{ev}$ and $\\d^{od}$ via the elements $\\d (x_1), ..., \\d (x_n)$. It is proved that the set of all even skew derivations of $\\L_n$ coincides with the set of all the inner skew derivations. Similar results are proved for derivations of $\\L_n$. In particular, $\\Der_K(\\L_n)$ is a faithful but not simple $\\Aut_K(\\L_n)$-module (where $K$ is reduced and $n\\geq 2$). All differential and skew differential ideals of $\\L_n$ are found. It is proved that the set of generic normal elements of $\\L_n$ that are not units forms a single $\\Aut_K(\\L_n)$-orbit (namely, $\\Aut_K(\\L_n)x_1$) if $n$ is even and two...

  18. Derivations and skew derivations of the Grassmann algebras

    E-print Network

    V. V. Bavula

    2007-04-29

    Surprisingly, skew derivations rather than ordinary derivations are more basic (important) object in study of the Grassmann algebras. Let $\\L_n = K\\lfloor x_1, ..., x_n\\rfloor$ be the Grassmann algebra over a commutative ring $K$ with ${1/2}\\in K$, and $\\d$ be a skew $K$-derivation of $\\L_n$. It is proved that $\\d$ is a unique sum $\\d = \\d^{ev} +\\d^{od}$ of an even and odd skew derivation. Explicit formulae are given for $\\d^{ev}$ and $\\d^{od}$ via the elements $\\d (x_1), ..., \\d (x_n)$. It is proved that the set of all even skew derivations of $\\L_n$ coincides with the set of all the inner skew derivations. Similar results are proved for derivations of $\\L_n$. In particular, $\\Der_K(\\L_n)$ is a faithful but not simple $\\Aut_K(\\L_n)$-module (where $K$ is reduced and $n\\geq 2$). All differential and skew differential ideals of $\\L_n$ are found. It is proved that the set of generic normal elements of $\\L_n$ that are not units forms a single $\\Aut_K(\\L_n)$-orbit (namely, $\\Aut_K(\\L_n)x_1$) if $n$ is even and two orbits (namely, $\\Aut_K(\\L_n)x_1$ and $\\Aut_K(\\L_n)(x_1+x_2... x_n)$) if $n$ is odd.

  19. Cytochalasin derivatives from a jellyfish-derived fungus Phoma sp.

    PubMed

    Kim, Eun La; Wang, Haibo; Park, Ju Hee; Hong, Jongki; Choi, Jae Sue; Im, Dong Soon; Chung, Hae Young; Jung, Jee H

    2015-05-15

    Four new cytochalasin derivatives (1-4), together with proxiphomin (5), were isolated from a jellyfish-derived fungus Phoma sp. The planar structures and relative stereochemistry were established by analysis of 1D and 2D NMR data. The absolute configuration was defined by the modified Mosher's method. The compounds showed moderate cytotoxicity against a small panel of human solid tumor cell lines (A549, KB, and HCT116). PMID:25881821

  20. Quinazoline derivatives: synthesis and bioactivities

    PubMed Central

    2013-01-01

    Owing to the significant biological activities, quinazoline derivatives have drawn more and more attention in the synthesis and bioactivities research. This review summarizes the recent advances in the synthesis and biological activities investigations of quinazoline derivatives. According to the main method the authors adopted in their research design, those synthetic methods were divided into five main classifications, including Aza-reaction, Microwave-assisted reaction, Metal-mediated reaction, Ultrasound-promoted reaction and Phase-transfer catalysis reaction. The biological activities of the synthesized quinazoline derivatives also are discussed. PMID:23731671

  1. Complex higher order derivative theories

    SciTech Connect

    Margalli, Carlos A.; Vergara, J. David [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-543, Mexico 04510 DF (Mexico)

    2012-08-24

    In this work is considered a complex scalar field theory with higher order derivative terms and interactions. A procedure is developed to quantize consistently this system avoiding the presence of negative norm states. In order to achieve this goal the original real scalar high order field theory is extended to a complex space attaching a complex total derivative to the theory. Next, by imposing reality conditions the complex theory is mapped to a pair of interacting real scalar field theories without the presence of higher derivative terms.

  2. 21 CFR 184.1685 - Rennet (animal-derived) and chymosin preparation (fermentation-derived).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...animal-derived) and chymosin preparation (fermentation-derived). 184.1685 Section...animal-derived) and chymosin preparation (fermentation-derived). (a)(1...4.23.4). It is derived, via fermentation, from a nonpathogenic and...

  3. 21 CFR 184.1685 - Rennet (animal-derived) and chymosin preparation (fermentation-derived).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...animal-derived) and chymosin preparation (fermentation-derived). 184.1685 Section...animal-derived) and chymosin preparation (fermentation-derived). (a)(1...4.23.4). It is derived, via fermentation, from a nonpathogenic and...

  4. 21 CFR 184.1685 - Rennet (animal-derived) and chymosin preparation (fermentation-derived).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...animal-derived) and chymosin preparation (fermentation-derived). 184.1685 Section...animal-derived) and chymosin preparation (fermentation-derived). (a)(1...4.23.4). It is derived, via fermentation, from a nonpathogenic and...

  5. 21 CFR 184.1685 - Rennet (animal-derived) and chymosin preparation (fermentation-derived).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...animal-derived) and chymosin preparation (fermentation-derived). 184.1685 Section...animal-derived) and chymosin preparation (fermentation-derived). (a)(1...4.23.4). It is derived, via fermentation, from a nonpathogenic and...

  6. 21 CFR 184.1685 - Rennet (animal-derived) and chymosin preparation (fermentation-derived).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...animal-derived) and chymosin preparation (fermentation-derived). 184.1685 Section...animal-derived) and chymosin preparation (fermentation-derived). (a)(1...4.23.4). It is derived, via fermentation, from a nonpathogenic and...

  7. Derivative-Free Optimization Proximal Point Methods Derivative-Free Proximal Point Conclusion Derivative-Free Optimization via Proximal

    E-print Network

    Derivative-Free Optimization Proximal Point Methods Derivative-Free Proximal Point Conclusion Derivative-Free Optimization via Proximal Point Methods Yves Lucet & Warren Hare July 24, 2013 1 / 26 #12;Derivative-Free Optimization Proximal Point Methods Derivative-Free Proximal Point Conclusion Outline 1

  8. Sol-gel derived sorbents

    DOEpatents

    Sigman, Michael E.; Dindal, Amy B.

    2003-11-11

    Described is a method for producing copolymerized sol-gel derived sorbent particles for the production of copolymerized sol-gel derived sorbent material. The method for producing copolymerized sol-gel derived sorbent particles comprises adding a basic solution to an aqueous metal alkoxide mixture for a pH.ltoreq.8 to hydrolyze the metal alkoxides. Then, allowing the mixture to react at room temperature for a precalculated period of time for the mixture to undergo an increased in viscosity to obtain a desired pore size and surface area. The copolymerized mixture is then added to an immiscible, nonpolar solvent that has been heated to a sufficient temperature wherein the copolymerized mixture forms a solid upon the addition. The solid is recovered from the mixture, and is ready for use in an active sampling trap or activated for use in a passive sampling trap.

  9. Magnetic cellulose-derivative structures

    DOEpatents

    Walsh, M.A.; Morris, R.S.

    1986-09-16

    Structures to serve as selective magnetic sorbents are formed by dissolving a cellulose derivative such as cellulose triacetate in a solvent containing magnetic particles. The resulting solution is sprayed as a fine mist into a chamber containing a liquid coagulant such as n-hexane in which the cellulose derivative is insoluble but in which the coagulant is soluble or miscible. On contact with the coagulant, the mist forms free-flowing porous magnetic microspheric structures. These structures act as containers for the ion-selective or organic-selective sorption agent of choice. Some sorption agents can be incorporated during the manufacture of the structure. 3 figs.

  10. Magnetic cellulose-derivative structures

    DOEpatents

    Walsh, Myles A. (Falmouth, MA); Morris, Robert S. (Fairhaven, MA)

    1986-09-16

    Structures to serve as selective magnetic sorbents are formed by dissolving a cellulose derivative such as cellulose triacetate in a solvent containing magnetic particles. The resulting solution is sprayed as a fine mist into a chamber containing a liquid coagulant such as n-hexane in which the cellulose derivative is insoluble but in which the coagulant is soluble or miscible. On contact with the coagulant, the mist forms free-flowing porous magnetic microspheric structures. These structures act as containers for the ion-selective or organic-selective sorption agent of choice. Some sorbtion agents can be incorporated during the manufacture of the structure.

  11. Informational derivation of Quantum Theory

    E-print Network

    G. Chiribella; G. M. D'Ariano; P. Perinotti

    2011-07-15

    Quantum theory can be derived from purely informational principles. Five elementary axioms-causality, perfect distinguishability, ideal compression, local distinguishability, and pure conditioning-define a broad class of theories of information-processing that can be regarded as a standard. One postulate-purification-singles out quantum theory within this class. The main structures of quantum theory, such as the representation of mixed states as convex combinations of perfectly distinguishable pure states, are derived directly from the principles without using the Hilbert space framework.

  12. Empirically derived injury prevention rules.

    PubMed Central

    Peterson, L; Schick, B

    1993-01-01

    This study describes a set of empirically derived safety rules that if followed, would have prevented the occurrence of minor injuries. Epidemiologists have criticized behavioral interventions as increasing "safe" behavior but failing to demonstrate a decrease in injury. The present study documents retrospectively the link between safe behavior and injury. It demonstrates that these empirically derived rules are very similar to rules for the prevention of serious injury. The study also shows that these rules are not widely accepted and implemented by parents. Suggestions for future research in this area are advanced. PMID:8307829

  13. 12 CFR 163.172 - Financial derivatives.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...financial derivative is a financial contract whose value...The most common types of financial derivatives are futures, forward commitments, options, and swaps. A mortgage...investment conduit, is not a financial derivative under...

  14. 12 CFR 563.172 - Financial derivatives.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...financial derivative is a financial contract whose value...The most common types of financial derivatives are futures, forward commitments, options, and swaps. A mortgage...investment conduit, is not a financial derivative under...

  15. 12 CFR 563.172 - Financial derivatives.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...financial derivative is a financial contract whose value...The most common types of financial derivatives are futures, forward commitments, options, and swaps. A mortgage...investment conduit, is not a financial derivative under...

  16. 12 CFR 163.172 - Financial derivatives.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...financial derivative is a financial contract whose value...The most common types of financial derivatives are futures, forward commitments, options, and swaps. A mortgage...investment conduit, is not a financial derivative under...

  17. 12 CFR 390.352 - Financial derivatives.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...financial derivative is a financial contract whose value...The most common types of financial derivatives are futures, forward commitments, options, and swaps. A mortgage...investment conduit, is not a financial derivative under...

  18. 12 CFR 390.352 - Financial derivatives.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...financial derivative is a financial contract whose value...The most common types of financial derivatives are futures, forward commitments, options, and swaps. A mortgage...investment conduit, is not a financial derivative under...

  19. 12 CFR 163.172 - Financial derivatives.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...financial derivative is a financial contract whose value...The most common types of financial derivatives are futures, forward commitments, options, and swaps. A mortgage...investment conduit, is not a financial derivative under...

  20. 12 CFR 563.172 - Financial derivatives.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...financial derivative is a financial contract whose value...The most common types of financial derivatives are futures, forward commitments, options, and swaps. A mortgage...investment conduit, is not a financial derivative under...

  1. 12 CFR 563.172 - Financial derivatives.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...financial derivative is a financial contract whose value...The most common types of financial derivatives are futures, forward commitments, options, and swaps. A mortgage...investment conduit, is not a financial derivative under...

  2. 12 CFR 563.172 - Financial derivatives.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...financial derivative is a financial contract whose value...The most common types of financial derivatives are futures, forward commitments, options, and swaps. A mortgage...investment conduit, is not a financial derivative under...

  3. 12 CFR 390.352 - Financial derivatives.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...financial derivative is a financial contract whose value...The most common types of financial derivatives are futures, forward commitments, options, and swaps. A mortgage...investment conduit, is not a financial derivative under...

  4. 40 CFR 721.1820 - Bisphenol derivative.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Bisphenol derivative. 721.1820 Section 721...Chemical Substances § 721.1820 Bisphenol derivative. (a) Chemical substance...chemical substance identified generically as bisphenol derivative (PMN No....

  5. 40 CFR 721.1820 - Bisphenol derivative.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Bisphenol derivative. 721.1820 Section 721...Chemical Substances § 721.1820 Bisphenol derivative. (a) Chemical substance...chemical substance identified generically as bisphenol derivative (PMN No....

  6. INCREMENTAL APPROACH TO DERIVATIVE POLAROGRAPHY

    Microsoft Academic Search

    Clemens Auerbach; H. L. Finston; George Kissel; Joseph Glickstein

    1961-01-01

    A new approach to direct current polarography is described, which ; provides an incremental approximation to the derivative current-voltage curve. ; Incremental polarograms are determined by a sequence of automatic operations. ; Instrumentation of relatively simple design was built, with extensive use of plug-; in ampllfiers. Provision is made for simultaneous or separate readout of both ; current increments and

  7. Quaternion Derivatives: The GHR Calculus

    E-print Network

    Dongpo Xu; Cyrus Jahanchahi; Clive C. Took; Danilo P. Mandic

    2014-09-25

    Quaternion derivatives in the mathematical literature are typically defined only for analytic (regular) functions. However, in engineering problems, functions of interest are often real-valued and thus not analytic, such as the standard cost function. The HR calculus is a convenient way to calculate formal derivatives of both analytic and non-analytic functions of quaternion variables, however, both the HR and other functional calculus in quaternion analysis have encountered an essential technical obstacle, that is, the traditional product rule is invalid due to the non- commutativity of the quaternion algebra. To address this issue, a generalized form of the HR derivative is proposed based on a general orthogonal system. The so introduced generalization, called the generalized HR (GHR) calculus, encompasses not just the left- and right-hand versions of quaternion derivative, but also enables solutions to some long standing problems, such as the novel product rule, the chain rule, the mean-valued theorem and Taylor's theorem. At the core of the proposed approach is the quaternion rotation, which can naturally be applied to other functional calculi in non-commutative settings. Examples on using the GHR calculus in adaptive signal processing support the analysis.

  8. Hedging Derivative Securities with Genetic

    Microsoft Academic Search

    Programming Shu-Heng Chen; Wo-Chiang Lee; Chia-Hsuan Yeh

    One of the most recent applications of GP to finance is to use genetic program- ming to derive option pricing formulas. Earlier studies take the Black-Scholes model as the true model and use the artificial data generated by it to train and to test GP. The aim of this paper is to provide some initial evidence of the empirical relevance

  9. Program for IIB Derivative Corrections

    E-print Network

    Gordon Chalmers

    2005-11-05

    A Matlab program is presented that computes derivative corrections in the S-dual invariant formulation for IIB graviton scattering to any order in perturbation theory. The coefficients of the four-point function are produced, pertaining to the non-logarithmic terms. The program can be modified to find coefficients of the higher-point functions. Instantons have not explicitly been included.

  10. Shuttle derived unmanned launch vehicle

    Microsoft Academic Search

    D. N. Buell; J. R. Tewell

    1985-01-01

    An unmanned launch vehicle derived using existing Space Transportation System (STS) components was studied. The vehicle incorporates a standard STS external tank and solid rocket boosters, a new payload module and a recoverable propulsion\\/avionics module housing the high cost avionics and propulsion systems. The main propulsion system is a cluster of three STS space shuttle main engines compatible with the

  11. Synthesis of Resorcinol Derived Spironitronates

    PubMed Central

    Marsini, Maurice A.; Huang, Yaodong; Van De Water, Ryan W.; Pettus, Thomas R. R.

    2008-01-01

    Syntheses of several unique spironitronates are reported. The key transformation involves the first known example of an ipso oxidative cyclization of nitro functionality. Oxidation proceeds from both o-and p-phenols. Reductions of these compounds provide novel spiroisoxazoline derivatives. PMID:17645344

  12. Heisenberg Double Versus Deformed Derivatives

    NASA Astrophysics Data System (ADS)

    Škoda, Zoran

    Two approaches to the tangent space of a noncommutative space whose coordinate algebra is the enveloping algebra of a Lie algebra are known: the Heisenberg double construction and the approach via deformed derivatives, usually defined by procedures involving orderings among noncommutative coordinates or equivalently involving realizations via formal differential operators. In an earlier work, we rephrased the deformed derivative approach introducing certain smash product algebra twisting a semicompleted Weyl algebra. We show here that the Heisenberg double in the Lie algebra case, is isomorphic to that product in a nontrivial way, involving a datum ? parametrizing the orderings or realizations in other approaches. This way, we show that the two different formalisms, used by different communities, for introducing the noncommutative phase space for the Lie algebra type noncommutative spaces are mathematically equivalent.

  13. [Morphoregulatory effects of xanthene derivatives].

    PubMed

    Buchenauer, H; Grossmann, F

    1970-03-01

    Of the compounds tested especially xanthene-9-carboxylic acid [I], applied via the roots (10(-4)M), strongly affected the morphogenesis of tomato plants. The leaves were deformed, the laminae reduced, the internodes shortened and the growth of axillary buds was stimulated. Geo- and phototropism of wheat and rye seedlings were disturbed. The observed effects are very similar to the influence of the structurally related derivatives of 9-hydroxyfluorenecarboxylic acid-(9) [II], known as "morphactins". PMID:24496665

  14. Myeloid-Derived Suppressor Cells

    Microsoft Academic Search

    Srinivas Nagaraj; Dmitry I. Gabrilovich

    \\u000a The development of tumor-specific T cell tolerance is largely responsible for tumor escape. Accumulation of myeloid-derived\\u000a suppressor cells (MDSCs) in animal tumor models as well as in cancer patients is involved in tumor-associated T cell tolerance.\\u000a In recent years, it has become increasingly evident that MDSCs bring about antigen-specific T cell tolerance by various mechanisms,\\u000a which is the focus of

  15. Faster Valuation of Financial Derivatives

    Microsoft Academic Search

    Spassimir H. Paskov; Joseph F. Traub

    1995-01-01

    High-dimensional integrals are usually solved with Monte Carlo algorithms although theory suggests that low-discrepancy algorithms are sometimes superior. We report on numerical testing which compares low-discrepancy and Monte Carlo algorithms on the evaluation of financial derivatives. The testing is performed on a Collateralized Mortgage Obligation (CMO) which is formulated as the computation of ten integrals of dimension up to 360.

  16. Chemical derivatives of castor oil

    Microsoft Academic Search

    K. T. Achaya

    1971-01-01

    The chemistry of castor oil and its derivatives is reviewed with particular reference to work done in India in general and\\u000a at the Regional Research Laboratory in Hyderabad in particular. Topics covered are the structure of castor oil, preparation\\u000a of ricinoleic acid and its glycerides, monoglycerides, surfactants from castor oil, diverse hydrogenations, dehydration, preparation\\u000a and properties of estolides, alkali fusion

  17. On Derivations Of Genetic Algebras

    NASA Astrophysics Data System (ADS)

    Mukhamedov, Farrukh; Qaralleh, Izzat

    2014-11-01

    A genetic algebra is a (possibly non-associative) algebra used to model inheritance in genetics. In application of genetics this algebra often has a basis corresponding to genetically different gametes, and the structure constant of the algebra encode the probabilities of producing offspring of various types. In this paper, we find the connection between the genetic algebras and evolution algebras. Moreover, we prove the existence of nontrivial derivations of genetic algebras in dimension two.

  18. Endothelium-derived endothelin-1

    Microsoft Academic Search

    Eric Thorin; David J. Webb

    2010-01-01

    One year after the revelation by Dr. Furchgott in 1980 that the endothelium was obligatory for acetylcholine to relax isolated\\u000a arteries, it was clearly shown that the endothelium could also promote contraction. In 1988, Dr. Yanagisawa's group identified\\u000a endothelin-1 (ET-1) as the first endothelium-derived contracting factor. The circulating levels of this short (21-amino acid)\\u000a peptide were quickly determined in humans,

  19. Comparative Study of Derivative Free Optimization Algorithms

    Microsoft Academic Search

    Nam Pham; A. Malinowski; T. Bartczak

    2011-01-01

    Derivative free optimization algorithms are often used when it is difficult to find function derivatives, or if finding such derivatives are time consuming. The Nelder Mead's simplex method is one of the most popular derivative free optimization algorithms in the fields of engineering, statistics, and sciences. This algorithm is favored and widely used because of its fast con- vergence and

  20. Binder enhanced refuse derived fuel

    DOEpatents

    Daugherty, Kenneth E. (Lewisville, TX); Venables, Barney J. (Denton, TX); Ohlsson, Oscar O. (Naperville, IL)

    1996-01-01

    A refuse derived fuel (RDF) pellet having about 11% or more particulate calcium hydroxide which is utilized in a combustionable mixture. The pellets are used in a particulate fuel bring a mixture of 10% or more, on a heat equivalent basis, of the RDF pellet which contains calcium hydroxide as a binder, with 50% or more, on a heat equivalent basis, of a sulphur containing coal. Combustion of the mixture is effective to produce an effluent gas from the combustion zone having a reduced SO.sub.2 and polycyclic aromatic hydrocarbon content of effluent gas from similar combustion materials not containing the calcium hydroxide.

  1. Myeloid-derived suppressor cells

    PubMed Central

    Chandra, Dinesh; Gravekamp, Claudia

    2013-01-01

    While conventional anticancer therapies, including surgical resection, radiotherapy, and/or chemotherapy, are relatively efficient at eliminating primary tumors, these treatment modalities are largely ineffective against metastases. At least in part, this reflects the rather inefficient delivery of conventional anticancer agents to metastatic lesions. We have recently demonstrated that myeloid-derived suppressor cells (MDSCs) can be used as cellular missiles to selectively deliver a radioisotope-coupled attenuated variant of Listeria monocytogenes to both primary and metastatic neoplastic lesions in mice with pancreatic cancer. This novel immunotherapeutic intervention robustly inhibited tumor growth while promoting a dramatic decrease in the number of metastases. PMID:24427545

  2. Deriving projective hyperspace from harmonic

    SciTech Connect

    Jain, Dharmesh; Siegel, Warren [C. N. Yang Institute for Theoretical Physics, State University of New York, Stony Brook, New York 11794-3840 (United States)

    2009-08-15

    We derive actions for projective N=2 superspace ('hyperspace') from those for harmonic hyperspace, including that for non-Abelian Yang-Mills theory (a new result). The method uses Wick rotation of the sphere from complex conjugate coordinates to real, null ones, which can be treated as independent. The result can be considered 'holographic' in that the dimension of the internal (R symmetry) space is reduced from 2 to 1, by solving equations of motion or gauge conditions for dependence on the other coordinate. The auxiliary nature of the redundant dimension makes the hypergraph rules and evaluation almost identical.

  3. Iron and iron derived radicals

    SciTech Connect

    Borg, D.C.; Schaich, K.M.

    1987-04-01

    We have discussed some reactions of iron and iron-derived oxygen radicals that may be important in the production or treatment of tissue injury. Our conclusions challenge, to some extent, the usual lines of thought in this field of research. Insofar as they are born out by subsequent developments, the lessons they teach are two: Think fastexclamation Think smallexclamation In other words, think of the many fast reactions that can rapidly alter the production and fate of highly reactive intermediates, and when considering the impact of competitive reactions on such species, think how they affect the microenvironment (on the molecular scale) ''seen'' by each reactive molecule. 21 refs., 3 figs., 1 tab.

  4. Fourth order spatial derivative gravity

    E-print Network

    F. S. Bemfica; M. Gomes

    2011-10-12

    In this work we study a modified theory of gravity that contains up to fourth order spatial derivatives as a model for the Horava-Lifshitz gravity. The propagator is evaluated and, as a result, it is obtained one extra pole corresponding to a spin two nonrelativistic massless particle, an extra term which jeopardizes renormalizability, besides the unexpected general relativity unmodified propagator. Then, unitarity is proved at the tree-level, where the general relativity pole has shown to have no dynamics, remaining only the two degrees of freedom of the new pole. Next, the nonrelativistic effective potential is determined from a scattering process of two identical massive gravitationally interacting bosons. In this limit, Newton's potential is obtained, together with a Darwin-like term that comes from the extra non-pole term in the propagator. Regarding renormalizability, this extra term may be harmful, by power counting, but it can be eliminated by adjusting the free parameters of the model. This adjustment is in accord with the detailed balance condition suggested in the literature and shows that the way in which extra spatial derivative terms are added is of fundamental importance.

  5. Shuttle derived unmanned launch vehicle

    NASA Astrophysics Data System (ADS)

    Buell, D. N.; Tewell, J. R.

    1985-04-01

    An unmanned launch vehicle derived using existing Space Transportation System (STS) components was studied. The vehicle incorporates a standard STS external tank and solid rocket boosters, a new payload module and a recoverable propulsion/avionics module housing the high cost avionics and propulsion systems. The main propulsion system is a cluster of three STS space shuttle main engines compatible with the STS launch pad. The orbital maneuvering system utilizes components and the reaction control system incorporates modified STS primary and vernier thrusters. A solid rocket propulsion system made up of six motors having a two second burn time is incorporated for decelerating the recoverable propulsion/avionics module to a soft landing. The sidemount shuttle derived launch vehicle can carry 147,000 pounds to a 150 nautical mile circular orbit from the Eastern Test Range of 104,000 pounds from the Western Test Range. With Centaur G-prime the payload capability to geosynchronous earth orbit is 24,500 pounds. Performance with an optimized upper stage and a stretched external tank was also investigated.

  6. Deriving Laws from Ordering Relations

    NASA Technical Reports Server (NTRS)

    Knuth, Kevin H.

    2004-01-01

    The effect of Richard T. Cox's contribution to probability theory was to generalize Boolean implication among logical statements to degrees of implication, which are manipulated using rules derived from consistency with Boolean algebra. These rules are known as the sum rule, the product rule and Bayes Theorem, and the measure resulting from this generalization is probability. In this paper, I will describe how Cox s technique can be further generalized to include other algebras and hence other problems in science and mathematics. The result is a methodology that can be used to generalize an algebra to a calculus by relying on consistency with order theory to derive the laws of the calculus. My goals are to clear up the mysteries as to why the same basic structure found in probability theory appears in other contexts, to better understand the foundations of probability theory, and to extend these ideas to other areas by developing new mathematics and new physics. The relevance of this methodology will be demonstrated using examples from probability theory, number theory, geometry, information theory, and quantum mechanics.

  7. Derivatives of Black Knight Technology

    NASA Astrophysics Data System (ADS)

    Hill, N.; Wright, D.

    This paper traces the line of descent from Black Knight to Black Arrow, and at the same time looks at various proposed projects, both civil and military, which were to be Black Knight derivatives, but which for one reason or another never saw the light of day. Research in this area is rather akin to anthropological work, tracing fossils from Homo erectus (Black Knight) to Homo sapiens (Black Arrow), knowing that a lot of the fossils found will not be on the direct line of descent, but represent branches that became extinct. This article attempts to cover designs, which, although they never made it to hardware, are none the less interesting technically, or shine light on the evolution of design philosophy.

  8. Deriving Laws from Ordering Relations

    NASA Technical Reports Server (NTRS)

    Knuth, Kevin H.

    2003-01-01

    It took much effort in the early days of non-Euclidean geometry to break away from the mindset that all spaces are flat and that two distinct parallel lines do not cross. Up to that point, all that was known was Euclidean geometry, and it was difficult to imagine anything else. We have suffered a similar handicap brought on by the enormous relevance of Boolean algebra to the problems of our age-logic and set theory. Previously, I demonstrated that the algebra of questions is not Boolean, but rather is described by the free distributive algebra. To get to this stage took much effort, as many obstacles-most self-placed-had to be overcome. As Boolean algebras were all I had ever known, it was almost impossible for me to imagine working with an algebra where elements do not have complements. With this realization, it became very clear that the sum and product rules of probability theory at the most basic level had absolutely nothing to do with the Boolean algebra of logical statements. Instead, a measure of degree of inclusion can be invented for many different partially ordered sets, and the sum and product rules fall out of the associativity and distributivity of the algebra. To reinforce this very important idea, this paper will go over how these constructions are made, while focusing on the underlying assumptions. I will derive the sum and product rules for a distributive lattice in general and demonstrate how this leads to probability theory on the Boolean lattice and is related to the calculus of quantum mechanical amplitudes on the partially ordered set of experimental setups. I will also discuss the rules that can be derived from modular lattices and their relevance to the cross-ratio of projective geometry.

  9. Derivative Sign Patterns in Two Dimensions

    ERIC Educational Resources Information Center

    Schilling, Kenneth

    2013-01-01

    Given a function defined on a subset of the plane whose partial derivatives never change sign, the signs of the partial derivatives form a two-dimensional pattern. We explore what patterns are possible for various planar domains.

  10. 32 CFR 2001.22 - Derivative classification.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...ADMINISTRATION CLASSIFIED NATIONAL SECURITY INFORMATION Identification and Markings § 2001.22 Derivative classification...example might appear as: Derived From: Memo, “Funding Problems,” October 20, 2008, Office of Administration,...

  11. A study on real estate derivatives

    E-print Network

    Lim, Jong Yoon, S.M. Massachusetts Institute of Technology

    2006-01-01

    All major asset classes including stocks and bonds have a well developed derivative market. Derivatives enable counterparties to reflect a view on a particular market, without having to trade the underlying asset. This ...

  12. Clustering based on Dissimilarity First Derivatives

    E-print Network

    Fred, Ana

    Clustering based on Dissimilarity First Derivatives Ana Fred Telecommunications Institute Instituto Superior Tecnico, Lisbon, Portugal, afred@lx.it.pt Abstract. A hierarchical agglomerative clustering. The first derivative of dissimilarity between neighboring pat- terns inside a natural cluster is modelled

  13. 40 CFR 721.10039 - Diethoxybenzenamine derivative, diazotized, coupled with aminonaphthalenesulfonic acid derivative...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...aminonaphthalenesulfonic acid derivative, ammonium salt (generic). 721.10039 Section 721...aminonaphthalenesulfonic acid derivative, ammonium salt (generic). (a) Chemical substance...aminonaphthalenesulfonic acid derivative, ammonium salt (PMN P-02-514) is subject to...

  14. 40 CFR 721.10039 - Diethoxybenzenamine derivative, diazotized, coupled with aminonaphthalenesulfonic acid derivative...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...aminonaphthalenesulfonic acid derivative, ammonium salt (generic). 721.10039 Section 721...aminonaphthalenesulfonic acid derivative, ammonium salt (generic). (a) Chemical substance...aminonaphthalenesulfonic acid derivative, ammonium salt (PMN P-02-514) is subject to...

  15. 40 CFR 721.10039 - Diethoxybenzenamine derivative, diazotized, coupled with aminonaphthalenesulfonic acid derivative...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...aminonaphthalenesulfonic acid derivative, ammonium salt (generic). 721.10039 Section 721...aminonaphthalenesulfonic acid derivative, ammonium salt (generic). (a) Chemical substance...aminonaphthalenesulfonic acid derivative, ammonium salt (PMN P-02-514) is subject to...

  16. Postgraduate Scholarship Pricing temperature derivatives and modelling

    E-print Network

    Banaji,. Murad

    the volumetric risk of the energy units sold, rather than the price risk of each unit. Weather derivativesPostgraduate Scholarship Pricing temperature derivatives and modelling the market price of risk: Pricing temperature derivatives and modelling the market price of risk. Main Supervisor: A. Alexandridis

  17. Derivations of Relativistic Force Transformation Equations

    Microsoft Academic Search

    D. V. Redži?; D. M. Davidovi?; M. D. Redži?

    2011-01-01

    The correct general form of relativistic transformation equations for the three-vector force is derived without using four-vectors, via the relativistic Newton's second law. The four-vector approach to the problem is also presented. The derivations extend or rectify previous derivations.

  18. Development of the beta-pressure derivative 

    E-print Network

    Hosseinpour-Zoonozi, Nima

    2007-04-25

    The proposed work provides a new definition of the pressure derivative function [that is the �²-derivative function, ��p �²d(t)], which is defined as the derivative of the logarithm of pressure drop data with respect ...

  19. A simple derivation of E = mc^2

    E-print Network

    Peter M. Brown

    2003-08-09

    Einstein's 1905 derivation of E = mc^2 has been criticized for being circular. Although such criticisms have been challenged it is certainly true that the reasoning in Einstein's original derivation is not at all obvious. Einstein's original derivation could have been made clearer. This article describes a clear way of doing so.

  20. Performance analysis of derivative-free filters

    Microsoft Academic Search

    J. Dunik; M. Simandl; O. Straka; L. Kral

    2005-01-01

    Nonlinear state estimation by the derivative-free Sigma Point Kalman Filters is treated. Particularly, impact of the derivative-free Kalman filters on estimation quality of the Sigma Point Gaussian Sum Filters is discussed. New relations between the Unscented Kalman Filter and the Divided Difference Filters are derived. The main stress is laid on the covariance matrixes which have crucial role for the

  1. How Much do Firms Hedge with Derivatives?

    Microsoft Academic Search

    Wayne R. Guay; S. P. Kothari

    2000-01-01

    For 234 large non-financial corporations using derivatives, we report the magnitude of their risk exposure hedged by financial derivatives. If interest rates, currency exchange rates, and commodity prices change simultaneously by three standard deviations, the median firm's derivatives portfolio, at most, generates $15 million in cash and $31 million in value. These amounts are modest relative to firm size, and

  2. Clinical status of benzoporphyrin derivative

    NASA Astrophysics Data System (ADS)

    Levy, Julia G.; Chan, Agnes H.; Strong, H. Andrew

    1996-01-01

    Benzoporphyrin derivative monoacid ring A (BPD) is currently in Phase II clinical trials for the treatment of cutaneous malignancies (basal cell carcinoma and cutaneous metastases) and psoriasis. Results to date suggest that this photosensitizer has potential in both of these areas. Recently, a clinical trial with BPD was initiated for the treatment of age related macular degeneration, a neovascular condition in the eye which leads to blindness. BPD is a lipophilic photosensitizer which is rapidly taken up by activated cells and the vascular endothelium of neovasculature. The PDT effects seen with BPD appear to be a combination of vascular occlusion and direct killing of target cells. Since many diseases involve either activated cells and/or neovasculature, PDT with photosensitizer with characteristics like those of BPD, has applications far wider than oncology. A new area of interest involving photosensitizers is that of immune modulation. A number of photosensitizers have been shown to effect immune modulation in animal models of immune dysfunction including autoimmunity (rheumatoid arthritis, lupus), cutaneous hypersensitivity and allografts. BPD and PHOTOFRINR have both been shown to be effective in ameliorating arthritic symptoms in a number of animal models. The mechanisms by which immune modulation is affected in these studies still remains to be resolved.

  3. Space-Derived Sewer Monitor

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The QuadraScan Longterm Flow Monitoring System is a second generation sewer monitor developed by American Digital Systems, Inc.'s founder Peter Petroff. Petroff, a former spacecraft instrumentation designer at Marshall Space Flight Center, used expertise based on principles acquired in Apollo and other NASA programs. QuadraScan borrows even more heavily from space technology, for example in its data acquisition and memory system derived from NASA satellites. "One-time" measurements are often plagued with substantial errors due to the flow of groundwater absorbed into the system. These system sizing errors stem from a basic informational deficiency: accurate, reliable data on how much water flows through a sewer system over a long period of time is very difficult to obtain. City officials are turning to "permanent," or long-term sewer monitoring systems. QuadraScan offers many advantages to city officials such as the early warning capability to effectively plan for city growth in order to avoid the crippling economic impact of bans on new sewer connections in effect in many cities today.

  4. Representations of partial derivatives in thermodynamics

    NASA Astrophysics Data System (ADS)

    Thompson, John R.; Manogue, Corinne A.; Roundy, David J.; Mountcastle, Donald B.

    2012-02-01

    One of the mathematical objects that students become familiar with in thermodynamics, often for the first time, is the partial derivative of a multivariable function. The symbolic representation of a partial derivative and related quantities present difficulties for students in both mathematical and physical contexts, most notably what it means to keep one or more variables fixed while taking the derivative with respect to a different variable. Material properties are themselves written as partial derivatives of various state functions (e.g., compressibility is a partial derivative of volume with respect to pressure). Research in courses at the University of Maine and Oregon State University yields findings related to the many ways that partial derivatives can be represented and interpreted in thermodynamics. Research has informed curricular development that elicits many of the difficulties using different representations (e.g., geometric) and different contexts (e.g., connecting partial derivatives to specific experiments).

  5. Comparison of Derivative Based and Derivative Free Kalman Filters for Multipath Channel Estimation in CDMA Networks

    Microsoft Academic Search

    Zahid Ali; Mohamed Adnan Landolsi; Mohammad A. Deriche

    2009-01-01

    The paper compares time delay and channel gain estimation for multipath fading code division multiple access (CDMA) signals using the derivative based and derivative free Kalman filters. We will be investigating the performance of the derivative based Kalman filter namely extended Kalman Filter (EKF) with the derivative free sigma point kalman filters (SPKF), namely the unscented Kalman Filter (UKF) and

  6. Plant-derived transfer DNAs.

    PubMed

    Rommens, Caius M; Bougri, Oleg; Yan, Hua; Humara, Jaime M; Owen, Joanna; Swords, Kathy; Ye, Jingsong

    2005-11-01

    The transfer of DNA from Agrobacterium to plant cell nuclei is initiated by a cleavage reaction within the 25-bp right border of Ti plasmids. In an effort to develop all-native DNA transformation vectors, 50 putative right border alternatives were identified in both plant expressed sequence tags and genomic DNA. Efficacy tests in a tobacco (Nicotiana tabacum) model system demonstrated that 14 of these elements displayed at least 50% of the activity of conventional Agrobacterium transfer DNA borders. Four of the most effective plant-derived right border alternatives were found to be associated with intron-exon junctions. Additional elements were embedded within introns, exons, untranslated trailers, and intergenic DNA. Based on the identification of a single right border alternative in Arabidopsis and three in rice (Oryza sativa), the occurrence of this motif was estimated at a frequency of at least 0.8x10(-8). Modification of plasmid DNA sequences flanking the alternative borders demonstrated that both upstream and downstream sequences play an important role in initiating DNA transfer. Optimal DNA transfer required the elements to be preceded by pyrimidine residues interspaced by AC-rich trinucleotides. Alteration of this organization lowered transformation frequencies by 46% to 93%. Despite their weaker resemblance with left borders, right border alternatives also functioned effectively in terminating DNA transfer, if both associated with an upstream A[C/T]T[C/G]A[A/T]T[G/T][C/T][G/T][C/G]A[C/T][C/T][A/T] domain and tightly linked cytosine clusters at their junctions with downstream DNA. New insights in border region requirements were used to construct an all-native alfalfa (Medicago sativa) transfer DNA vector that can be used for the production of intragenic plants. PMID:16244143

  7. Opioid peptide-derived analgesics.

    PubMed

    Schiller, Peter W

    2005-01-01

    Two recent developments of opioid peptide-based analgesics are reviewed. The first part of the review discusses the dermorphin-derived, cationic-aromatic tetrapeptide H-Dmt-D-Arg-Phe-Lys-NH(2) ([Dmt(1)]DALDA, where Dmt indicates 2',6'-dimethyltyrosine), which showed subnanomolar mu receptor binding affinity, extraordinary mu receptor selectivity, and high mu agonist potency in vitro. In vivo, [Dmt(1)]DALDA looked promising as a spinal analgesic because of its extraordinary antinociceptive effect (3000 times more potent than morphine) in the mouse tail-flick assay, long duration of action (4 times longer than morphine), and lack of effect on respiration. Unexpectedly, [Dmt(1)]DALDA also turned out to be a potent and long-acting analgesic in the tail-flick test when given subcutaneously (s.c.), indicating that it is capable of crossing the blood-brain barrier. Furthermore, little or no cross-tolerance was observed with s.c. [Dmt(1)]DALDA in morphine-tolerant mice. The second part of the review concerns the development of mixed mu agonist/delta antagonists that, on the basis of much evidence, are expected to be analgesics with a low propensity to produce tolerance and physical dependence. The prototype pseudopeptide H-Dmt-TicPsi[CH(2)NH]Phe-Phe-NH(2) (DIPP-NH(2)[Psi], where Tic indicates 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid) showed subnanomolar mu and delta receptor binding affinities and the desired mu agonist/delta antagonist profile in vitro. DIPP-NH(2)[Psi] produced a potent analgesic effect after intracerebroventricular administration in the rat tail-flick assay, no physical dependence, and less tolerance than morphine. The results obtained with DIPP-NH(2)[Psi] indicate that mixed mu agonist/delta antagonists look promising as analgesic drug candidates, but compounds with this profile that are systemically active still need to be developed. PMID:16353933

  8. Drug Nanoparticle Formulation Using Ascorbic Acid Derivatives

    PubMed Central

    Moribe, Kunikazu; Limwikrant, Waree; Higashi, Kenjirou; Yamamoto, Keiji

    2011-01-01

    Drug nanoparticle formulation using ascorbic acid derivatives and its therapeutic uses have recently been introduced. Hydrophilic ascorbic acid derivatives such as ascorbyl glycoside have been used not only as antioxidants but also as food and pharmaceutical excipients. In addition to drug solubilization, drug nanoparticle formation was observed using ascorbyl glycoside. Hydrophobic ascorbic acid derivatives such as ascorbyl mono- and di-n-alkyl fatty acid derivatives are used either as drugs or carrier components. Ascorbyl n-alkyl fatty acid derivatives have been formulated as antioxidants or anticancer drugs for nanoparticle formulations such as micelles, microemulsions, and liposomes. ASC-P vesicles called aspasomes are submicron-sized particles that can encapsulate hydrophilic drugs. Several transdermal and injectable formulations of ascorbyl n-alkyl fatty acid derivatives were used, including ascorbyl palmitate. PMID:21603195

  9. Novel oxindole derivatives and their biological activity.

    PubMed

    Strigácová, J; Hudecová, D; Mikulásová, M; Varecka, L; Lásiková, A; Végh, D

    2001-01-01

    The antifungal activity of fourteen novel derivatives of oxindole with side chain was studied using representatives of toxinogenic, phytopathogenic and dermatophytic filamentous fungi. Derivatives with exocyclic C=C bond in position C-3 exhibited a higher antifungal activity compared with derivatives with an exocyclic C-C bond in the same position. The strongest antifungal effects were shown by 3-(-2-thienoylmethylidene)-indol-2(3H)-ones. PMID:11702401

  10. Adsorption and desorption of cellulose derivatives

    Microsoft Academic Search

    C. W. Hoogendam

    1998-01-01

    Cellulose derivatives, in particular carboxymethyl cellulose (CMC) are used in many (industrial) applications. The aim of this work is to obtain insight into the adsorption mechanism of cellulose derivatives on solid-liquid interfaces.In chapter 1<\\/strong> of this thesis we discuss some applications of cellulose derivatives. Application of CMC in pelleting of iron ore and in papermaking and the role of adsorption

  11. Biosynthesis and biotechnological production of serotonin derivatives

    Microsoft Academic Search

    Kiyoon Kang; Sangkyu Park; Young Soon Kim; Sungbeom Lee; Kyoungwhan Back

    2009-01-01

    Serotonin derivatives belong to a class of phenylpropanoid amides found at low levels in a wide range of plant species. Representative\\u000a serotonin derivatives include feruloylserotonin (FS) and 4-coumaroylserotonin (CS). Since the first identification of serotonin\\u000a derivatives in safflower seeds, their occurrence, biological significance, and pharmacological properties have been reported.\\u000a Recently, serotonin N-hydroxycinnamoyl transferase (SHT), which is responsible for the synthesis

  12. A nonlinear two compartmental fractional derivative model

    Microsoft Academic Search

    Jovan K. Popovi?; Diana Doli?anin; Milan R. Rapai?; Stevan Pilipovic; Teodor M. Atanackovi?

    This study presents a new nonlinear two compartmental model and its application to the evaluation of valproic acid (VPA) pharmacokinetics\\u000a in human volunteers after oral administration. We have used literature VPA concentrations. In the model, the integer order\\u000a derivatives are replaced by derivatives of real order often called fractional order derivatives. Physically that means that\\u000a the history (memory) of a

  13. Early alternative derivations of Fechner's law.

    PubMed

    Masin, Sergio Cesare; Zudini, Verena; Antonelli, Mauro

    2009-01-01

    Historians of psychology, notably Boring, fostered Fechner's idea that Weber's law is the indispensable basis for the derivation of the logarithmic psychophysical law. However, it is shown here that Bernoulli in 1738 and Thurstone in 1931 derived the logarithmic law using principles other than Weber's law and that Fechner and Thurstone based their derivations on the principles originally employed by Bernoulli. It is concluded that awareness of researchers about Bernoulli's and Thurstone's derivations could expand the directions of research on the form of the psychophysical law. (c) 2009 Wiley Periodicals, Inc. PMID:19137615

  14. Mantle derived economic sulfide mineralization?

    NASA Astrophysics Data System (ADS)

    Krivolutskaya, Nadezda; Gongalskiy, Bronislav; Svirskaya, Natalia

    2014-05-01

    Sulfide ores of the unique Pt-Cu-Ni Noril'sk deposits are characterized by heavy sulfur isotopic composition (d34S = 6-18 ‰ ; Grinenko, 1985). These data are traditionally explained by the crustal contamination of the mantle melts by Devonian sedimentary rocks with anhydrites at certain depths or in a chamber of crystallization (Naldrett, 1992; Li et al., 2009). However, data on the distribution of major and trace elements and isotopic composition (their eNd, 87Sr/86Sr, d34S) in the contact zones of the intrusions with the host rocks are at variance with any significant in-situ contamination. Moreover , the mechanism of the "digestion" of this high-temperature material (Tm = 1430ºC) by the lower temperature magma (1250ºC) has never been analyzed and questioned. Our pioneering data on the sulfur radiogenic isotopes in the anhydrite are in conflict with the hypothesis that this mineral could serve as a sulfur source for the Noril'sk ores. The fact that the average composition of the intrusions is independent on the stratigraphic setting of these intrusions, which can be hosted by limestone, sandstone, and/or basalt, provides further support for the idea that no assimilation took place at the depths of the chambers in which the melts crystallized.The reason for the heavy sulfur isotopic composition of ores in the Noril'sk district is still uncertain. Last data obtained on the sulfur isotopic composition of basalts and ores from some intrusions in the Taimyr Peninsula likely provide a clue to this problem. The highest d34S values in rocks of all of the trap formations were detected in the Gudchikhinsky picrites (d34S = +8,7; Ripley et al., 2003) formed from a primitive mantle magma. They are geochemically similar to the rocks from the Dyumtaleysky Massif (d34S = 12.2; Krivolutskaya and Gongalsky, 2013) which crystallized from a primitive mantle-derived magma (with no Ta-Nb and Pb anomalies and high Gd/Yb ratio) too. This intrusion comprises economic important sulfide ores with geochemical and mineralogical characteristics similar to unique Noril'sk deposits - Talnakh, Okty'abr sky and Norilsk 1. The features of the Dyumtaleysky massif can be explained by its origin from an unusual sulfide-bearing mantle source that had sulfides through earlier crustal-mantle interaction. These data support that the mantle source of magmas in the Noril'sk district was enriched in the heavy sulfur isotope. It is the age difference that could be responsible for the unusual composition of the Noril'sk ores, because the mantle source in the Early Mesozoic was remarkably different from that in the Proterozoic one, when practically all Cu-Ni deposits worldwide were produced.

  15. Cluster algebras and derived categories Bernhard Keller

    E-print Network

    Keller, Bernhard - Institut de Mathématiques de Jussieu, Université Paris 7

    Cluster algebras and derived categories Bernhard Keller Abstract. This is an introductory survey on cluster algebras and their (additive) cat- egorification using derived categories of Ginzburg algebras. After a gentle introduction to cluster combinatorics, we review important examples of coordinate rings

  16. Seamount resolution in satellite-derived bathymetry

    Microsoft Academic Search

    Peter Etnoyer

    2005-01-01

    I compare satellite-derived global relief data on 13 seamounts in the northeast Pacific Ocean to echosounder-derived multibeam values from the Gulf of Alaska Seamount Expeditions and the West Coast Seamounts and Ridges Multibeam Surveys for peak height, latitude, longitude, and midsection area. I find Smith and Sandwell's (1997) global sea floor topography relatively accurate for peak geoposition but generally deeper

  17. Derive Workshop Matrix Algebra and Linear Algebra.

    ERIC Educational Resources Information Center

    Townsley Kulich, Lisa; Victor, Barbara

    This document presents the course content for a workshop that integrates the use of the computer algebra system Derive with topics in matrix and linear algebra. The first section is a guide to using Derive that provides information on how to write algebraic expressions, make graphs, save files, edit, define functions, differentiate expressions,…

  18. Equity and Equity Index Derivatives Trading Strategies

    E-print Network

    Weinberger, Hans

    Omega (Leverage Effect) #12;Strategies for Stock Options and Equity Index Options 47 Trading Strategiese u r e x Equity and Equity Index Derivatives Trading Strategies e u r e x #12;Please Note and corresponding preparatory material. #12;e u r e x Equity and Equity Index Derivatives Trading Strategies #12

  19. Aging and rejuvenation with fractional derivatives

    NASA Astrophysics Data System (ADS)

    Aquino, Gerardo; Bologna, Mauro; Grigolini, Paolo; West, Bruce J.

    2004-09-01

    We discuss a dynamic procedure that makes fractional derivatives emerge in the time asymptotic limit of non-Poisson processes. We find that two-state fluctuations, with an inverse power-law distribution of waiting times, finite first moment, and divergent second moment, namely, with the power index ? in the interval 2derivative term. We show that the order of the fractional derivative depends on the age of the process under study. If the system is infinitely old, the order of the fractional derivative, o , is given by o=3-? . A brand new system is characterized by the degree o=?-2 . If the system is prepared at time -ta<0 and the observation begins at time t=0 , we derive the following scenario. For times 0derivative with o=3-? . Upon time increase the system undergoes a rejuvenation process that in the time limit t?ta yields o=?-2 . The intermediate time regime is probably incompatible with a picture based on fractional derivatives, or, at least, with a mono-order fractional derivative.

  20. Dihydrochalcones and phenanthrene derivatives from Fissistigma bracteolatum

    Microsoft Academic Search

    Zhu Hongping; Lu Xiaoling; Sun Xiaohong; Xu Qiangzhi; Jiao Binghua

    2010-01-01

    Three dihydrochalcones derivatives 1-3, flavone 4 and phenanthrene derivative 5 were isolated, together with 9 known compounds, from the air-dried root bark of Fissistigma bracteolatum Chatterjee. Their structures were determined by spectroscopic (NMR, MS) and chemical methodologies.

  1. Orchard navigation using derivative free Kalman filtering

    Microsoft Academic Search

    Soren Hansen; Enis Bayramoglu; Jens Christian Andersen; Ole Ravn; Nils Andersen; Niels Kjolstad Poulsen

    2011-01-01

    This paper describes the use of derivative free filters for mobile robot localization and navigation in an orchard. The localization algorithm fuses odometry and gyro measurements with line features representing the surrounding fruit trees of the orchard. The line features are created on basis of 2D laser scanner data by a least square algorithm. The three derivative free filters are

  2. Phenolic-resin-derived activated carbons

    Microsoft Academic Search

    S. R. Tennison

    1998-01-01

    A novel binderless preparative route is described for the production of phenolic-resin-derived carbons for use as catalyst supports and adsorbents. The carbons can be produced in a wide variety of physical forms ranging from simple granules to large monolithic structures. The fully interconnected macropore structure of the carbons, which derives from the interconnected voids between the primary resin particles, can

  3. Log and Exponential Derivatives Here are the formulas for the derivatives of ln x and ex

    E-print Network

    Ikenaga, Bruce

    of these cases, d dx ln(stuff) = (the derivative of stuff) (stuff) . Example. (Logarithmic differentiation) . d dx ecot x = -(csc x)2 ecot x . d dx e1/x = - 1 x2 e1/x . In all of these cases, d dx e(stuff) = (the derivative of stuff)e(stuff) . You can use the formula for the derivative of ln x to derive

  4. Risk management, derivatives and shariah compliance

    NASA Astrophysics Data System (ADS)

    Bacha, Obiyathulla Ismath

    2013-04-01

    Despite the impressive growth of Islamic Banking and Finance (IBF), a number of weaknesses remain. The most important of this is perhaps the lack of shariah compliant risk management tools. While the risk sharing philosophy of Islamic Finance requires the acceptance of risk to justify returns, the shariah also requires adherents to avoid unnecessary risk-maysir. The requirement to avoid maysir is in essence a call for the prudent management of risk. Contemporary risk management revolves around financial engineering, the building blocks of which are financial derivatives. Despite the proven efficacy of derivatives in the management of risk in the conventional space, shariah scholars appear to be suspicious and uneasy with their use in IBF. Some have imposed outright prohibition of their use. This paper re-examines the issue of contemporary derivative instruments and shariah compliance. The shariah compatibility of derivatives is shown in a number of ways. First, by way of qualitative evaluation of whether derivatives can be made to comply with the key prohibitions of the sharia. Second, by way of comparing the payoff profiles of derivatives with risk sharing finance and Bai Salam contracts. Finally, the equivalence between shariah compliant derivatives like the IPRS and Islamic FX Currency Forwards with conventional ones is presented.

  5. Novel oxindole derivatives and their biological activity

    Microsoft Academic Search

    J. Strigácová; D. Hudecová; M. Mikulášová; L'. Vare?ka; A. Lásiková; D. Végh

    2001-01-01

    The antifungal activity of fourteen novel derivatives of oxindole with side chain was studied using representatives of toxinogenic,\\u000a phytopathogenic and dermatophytic filamentous fungi. Derivatives with exocyclic C=C bond in position C-3 exhibited a higher\\u000a antifungal activity compared with derivatives with an exocyclic C?C bond in the same position. The strongest antifungal effects\\u000a were shown by 3-(-2-thienoylmethylidene)-indol-2(3H)-ones.

  6. The Theory of Quaternion Matrix Derivatives

    NASA Astrophysics Data System (ADS)

    Xu, Dongpo; Mandic, Danilo P.

    2015-03-01

    A systematic theory is introduced for calculating the derivatives of quaternion matrix function with respect to quaternion matrix variables. The proposed methodology is equipped with the matrix product rule and chain rule and it is able to handle both analytic and nonanalytic functions. This corrects a flaw in the existing methods, that is, the incorrect use of the traditional product rule. In the framework introduced, the derivatives of quaternion matrix functions can be calculated directly without the differential of this function. Key results are summarized in tables. Several examples show how the quaternion matrix derivatives can be used as an important tool for solving problems related to signal processing.

  7. Analysis and the Derivation of Valid Objectives

    ERIC Educational Resources Information Center

    Tiemann, Philip W.

    1973-01-01

    Author states that "to the extent that behavioral objectives are derived from an analysis of relatively broad objectives, they can serve as valid criteria which enable our students to avoid trivia." (Author)

  8. 45 CFR 601.5 - Derivative classification.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION CLASSIFICATION AND DECLASSIFICATION...classified, and marking the newly developed material consistent with the marking of the...classification markings derived from source material or as directed by a classification...

  9. 45 CFR 601.5 - Derivative classification.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION CLASSIFICATION AND DECLASSIFICATION...classified, and marking the newly developed material consistent with the marking of the...classification markings derived from source material or as directed by a classification...

  10. 45 CFR 601.5 - Derivative classification.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION CLASSIFICATION AND DECLASSIFICATION...classified, and marking the newly developed material consistent with the marking of the...classification markings derived from source material or as directed by a classification...

  11. 45 CFR 601.5 - Derivative classification.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION CLASSIFICATION AND DECLASSIFICATION...classified, and marking the newly developed material consistent with the marking of the...classification markings derived from source material or as directed by a classification...

  12. 45 CFR 601.5 - Derivative classification.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION CLASSIFICATION AND DECLASSIFICATION...classified, and marking the newly developed material consistent with the marking of the...classification markings derived from source material or as directed by a classification...

  13. SCM Forcing Data Derived from NWP Analyses

    SciTech Connect

    Jakob, Christian

    2008-01-15

    Forcing data, suitable for use with single column models (SCMs) and cloud resolving models (CRMs), have been derived from NWP analyses for the ARM (Atmospheric Radiation Measurement) Tropical Western Pacific (TWP) sites of Manus Island and Nauru.

  14. Direct synthesis of pyridine and pyrimidine derivatives

    E-print Network

    Hill, Matthew D. (Matthew Dennis)

    2008-01-01

    I. Synthesis of Substituted Pyridine Derivatives via the Ruthenium-Catalyzed Cycloisomerization of 3-Azadienynes. The two-step conversion of various N-vinyl and N-aryl amides to the corresponding substituted pyridines and ...

  15. Catalytic combustion of coal-derived liquids

    NASA Technical Reports Server (NTRS)

    Bulzan, D. L.; Tacina, R. R.

    1981-01-01

    A noble metal catalytic reactor was tested with three grades of SRC 2 coal derived liquids, naphtha, middle distillate, and a blend of three parts middle distillate to one part heavy distillate. A petroleum derived number 2 diesel fuel was also tested to provide a direct comparison. The catalytic reactor was tested at inlet temperatures from 600 to 800 K, reference velocities from 10 to 20 m/s, lean fuel air ratios, and a pressure of 3 x 10 to the 5th power Pa. Compared to the diesel, the naphtha gave slightly better combustion efficiency, the middle distillate was almost identical, and the middle heavy blend was slightly poorer. The coal derived liquid fuels contained from 0.58 to 0.95 percent nitrogen by weight. Conversion of fuel nitrogen to NOx was approximately 75 percent for all three grades of the coal derived liquids.

  16. Confidence Measures Derived from an Acceptor HMM 

    E-print Network

    Williams, Gethin; Renals, Steve

    In this paper we define a number of confidence measures derived from an acceptor HMM and evaluate their performance for the task of utterance verification using the North American Business News (NAB) and Broadcast News ...

  17. Tri and tetrahydroxycoumarin derivatives from Tetraphis pellucida

    Microsoft Academic Search

    Marion Jung; Hans Geiger; Hans Dietmar Zinsmeister

    1995-01-01

    From gametophytes of Tetraphis pellucida have been isolated eight different tri- and tetrahydroxycoumarin derivatives; three of them are new natural products, the structures of which were elucidated spectroscopically. The taxonomic relevance of the results is discussed.

  18. SCM Forcing Data Derived from NWP Analyses

    DOE Data Explorer

    Jakob, Christian

    Forcing data, suitable for use with single column models (SCMs) and cloud resolving models (CRMs), have been derived from NWP analyses for the ARM (Atmospheric Radiation Measurement) Tropical Western Pacific (TWP) sites of Manus Island and Nauru.

  19. Casimir Energy Associated With Fractional Derivative Field

    SciTech Connect

    Lim, S. C. [Faculty of Engineering, Multimedia University, Cyberjaya 63100, Selangor (Malaysia)

    2007-04-28

    Casimir energy associated with fractional derivative scalar massless field at zero and positive temperature can be obtained using the regularization based on generalized Riemann zeta function of Epstein-Hurwitz type.

  20. Perspectives on Biologically Active Camptothecin Derivatives.

    PubMed

    Liu, Ying-Qian; Li, Wen-Qun; Morris-Natschke, Susan L; Qian, Keduo; Yang, Liu; Zhu, Gao-Xiang; Wu, Xiao-Bing; Chen, An-Liang; Zhang, Shao-Yong; Nan, Xiang; Lee, Kuo-Hsiung

    2015-07-01

    Camptothecins (CPTs) are cytotoxic natural alkaloids that specifically target DNA topoisomerase I. Research on CPTs has undergone a significant evolution from the initial discovery of CPT in the late 1960s through the study of synthetic small-molecule derivatives to investigation of macromolecular constructs and formulations. Over the past years, intensive medicinal chemistry efforts have generated numerous CPT derivatives. Three derivatives, topotecan, irinotecan, and belotecan, are currently prescribed as anticancer drugs, and several related compounds are now in clinical trials. Interest in other biological effects, besides anticancer activity, of CPTs is also growing exponentially, as indicated by the large number of publications on the subject during the last decades. Therefore, the main focus of the present review is to provide an ample but condensed overview on various biological activities of CPT derivatives, in addition to continued up-to-date coverage of anticancer effects. PMID:25808858

  1. Formal Derivation of a Class of Computers 

    E-print Network

    Wang, Li-Guo

    The aim of this thesis is to investigate how to use logic-based specification, construction, and proof methods to formally derive a class of computers. Differing from the traditional concepts of specification, verification ...

  2. Derived Bracket Construction and Manin Products

    Microsoft Academic Search

    Kyousuke Uchino

    2010-01-01

    We will extend the classical derived bracket construction to any algebra over a binary quadratic operad. We will show that\\u000a the derived product construction is a functor given by the Manin white product with the operad of permutation algebras. As\\u000a an application, we will show that the operad of prePoisson algebras is isomorphic to the Manin black product of the

  3. Derived versus full name brand extensions

    Microsoft Academic Search

    Sergio Olavarrieta; Eduardo Torres; Arturo Vásquez-Parraga; Cristóbal Barra

    2009-01-01

    Most brand extension studies follow the assumption that brand extensions use the full original parent brand name (e.g., Oral-B tooth brush may extend to Oral-B dental floss). However, some companies use derived brand names in their brand extension strategies (e.g. Nestea Iced Tea). This study explores the advantages and disadvantages of derived brand extensions compared to full name extensions. The

  4. On Higher Spatial Derivative Field Theories

    E-print Network

    Pedro R. S. Gomes; M. Gomes

    2012-04-23

    In this work, we employ renormalization group methods to study the general behavior of field theories possessing anisotropic scaling in the spacetime variables. The Lorentz breaking symmetry that accompanies these models are either soft, if no higher spatial derivative is present, or it may have a more complex structure if higher spatial derivatives are also included. Both situations are discussed in models with only scalar fields and also in models with fermions as a Yukawa like model.

  5. Derivation of mouse embryonic stem cells

    Microsoft Academic Search

    Vít?zslav Bryja; Sonia Bonilla; Ernest Arenas

    2006-01-01

    Here we describe a simple and efficient protocol for derivation of germline chimera-competent mouse embryonic stem cells (mESCs) from embryonic day 3.5 (E3.5) blastocysts. The protocol involves the use of early-passage mouse embryonic fibroblast feeders (MEF) and the alternation of fetal bovine serum– and serum replacement (SR)–containing media. As compared to other available protocols for mESCs derivation, our protocol differs

  6. Derivatives of the H-function

    NASA Astrophysics Data System (ADS)

    Viik, Tonu

    1993-06-01

    The first two derivatives and the mixed derivative of the H-function with respect to the angular variable and the albedo of single scattering are studied in the case of isotropic scattering using the kernel approximation method. This allows to obtain simple formulae the accuracy of which is estimated to be very good in rather low orders of approximation. Some samples of numerical results are given with eight decimal accuracy.

  7. Pyrogallol derivatives as antioxidants for carotene

    Microsoft Academic Search

    E. M. Bickoff; G. M. Coppinger; A. L. Livingston; Tod W. Campbell

    1952-01-01

    Conclusions  Certain derivatives of pyrogallol have been shown to possess marked activity as antioxidants for carotene in some systems\\u000a while they are of little value in others. Thus all the derivatives which are more effective than pyrogallol in protecting\\u000a carotene in mineral oil are very much less effective than pyrogallol in lard and, with two exceptions, are also less effective\\u000a in

  8. Nonlinear optical properties of xanthone derivatives

    NASA Astrophysics Data System (ADS)

    Imanishi, Yasuo; Itoh, Yuzo; Kakuta, Atsushi; Mukoh, Akio

    1991-03-01

    Xanthone derivatives have been found to be new organic nonlinear materials with a high efficiency of second harmonic generation (SHG) and transparency in visible region. For example, 3-aminoxanthone had a high SHG activity (SHG emission of this sample was 1 3 times higher than that of urea ) and good thermal stability (mp=232 C ) . A single crystal of this sample was transparent above 430nm. The SHG properties for other xanthone derivatives were also investigated.

  9. Asymptotic safety in higher-derivative gravity

    E-print Network

    Dario Benedetti; Pedro F. Machado; Frank Saueressig

    2009-07-07

    We study the non-perturbative renormalization group flow of higher-derivative gravity employing functional renormalization group techniques. The non-perturbative contributions to the $\\beta$-functions shift the known perturbative ultraviolet fixed point into a non-trivial fixed point with three UV-attractive and one UV-repulsive eigendirections, consistent with the asymptotic safety conjecture of gravity. The implication of this transition on the unitarity problem, typically haunting higher-derivative gravity theories, is discussed.

  10. Neutron stars in the derivative coupling model

    Microsoft Academic Search

    N. K. Glendenning; F. Weber; S. A. Moszkowski

    1992-01-01

    Properties of neutron stars derived from the hybrid derivative coupling model of nuclear field theory are studied. Generalized beta equilibrium with all baryon types to convergence is allowed. Hyperon couplings compatible with the inferred binding energy of the lambda hyperon in saturated nuclear matter predict a large hyperon population, with neutrons having a bare majority population in a 1.5{ital M}{sub

  11. Paired electrochemical synthesis of new organosulfone derivatives

    Microsoft Academic Search

    D. Nematollahi; F. Varmaghani

    2008-01-01

    Electrochemical oxidation of “cathodically generated 4-aminocatechol (2)” has been studied in the presence of 4-toluenesulfinic acid (4a) and benzenesulfinic acid (4b) as nucleophiles in aqueous solutions, using cyclic voltammetry and controlled-potential coulometry. The results indicate that the o-benzoquinone derived from 4-aminocatechol (2) participates in Michael addition reaction with 4a or 4b to form the corresponding new organosulfone derivatives (5a and

  12. Analytic computation of energy derivatives - Relationships among partial derivatives of a variationally determined function

    NASA Technical Reports Server (NTRS)

    King, H. F.; Komornicki, A.

    1986-01-01

    Formulas are presented relating Taylor series expansion coefficients of three functions of several variables, the energy of the trial wave function (W), the energy computed using the optimized variational wave function (E), and the response function (lambda), under certain conditions. Partial derivatives of lambda are obtained through solution of a recursive system of linear equations, and solution through order n yields derivatives of E through order 2n + 1, extending Puley's application of Wigner's 2n + 1 rule to partial derivatives in couple perturbation theory. An examination of numerical accuracy shows that the usual two-term second derivative formula is less stable than an alternative four-term formula, and that previous claims that energy derivatives are stationary properties of the wave function are fallacious. The results have application to quantum theoretical methods for the computation of derivative properties such as infrared frequencies and intensities.

  13. Structure Activity Relationship of Brevenal Hydrazide Derivatives

    PubMed Central

    Goodman, Allan; McCall, Jennifer R.; Jacocks, Henry M.; Thompson, Alysha; Baden, Daniel; Abraham, William M.; Bourdelais, Andrea

    2014-01-01

    Brevenal is a ladder frame polyether produced by the dinoflagellate Karenia brevis. This organism is also responsible for the production of the neurotoxic compounds known as brevetoxins. Ingestion or inhalation of the brevetoxins leads to adverse effects such as gastrointestinal maladies and bronchoconstriction. Brevenal shows antagonistic behavior to the brevetoxins and shows beneficial attributes when administered alone. For example, in an asthmatic sheep model, brevenal has been shown to increase tracheal mucosal velocity, an attribute which has led to its development as a potential treatment for Cystic Fibrosis. The mechanism of action of brevenal is poorly understood and the exact binding site has not been elucidated. In an attempt to further understand the mechanism of action of brevenal and potentially develop a second generation drug candidate, a series of brevenal derivatives were prepared through modification of the aldehyde moiety. These derivatives include aliphatic, aromatic and heteroaromatic hydrazide derivatives. The brevenal derivatives were tested using in vitro synaptosome binding assays to determine the ability of the compounds to displace brevetoxin and brevenal from their native receptors. A sheep inhalation model was used to determine if instillation of the brevenal derivatives resulted in bronchoconstriction. Only small modifications were tolerated, with larger moieties leading to loss of affinity for the brevenal receptor and bronchoconstriction in the sheep model. PMID:24686558

  14. Derivation of mouse embryonic stem cells.

    PubMed

    Bryja, Vítezslav; Bonilla, Sonia; Arenas, Ernest

    2006-01-01

    Here we describe a simple and efficient protocol for derivation of germline chimera-competent mouse embryonic stem cells (mESCs) from embryonic day 3.5 (E3.5) blastocysts. The protocol involves the use of early-passage mouse embryonic fibroblast feeders (MEF) and the alternation of fetal bovine serum- and serum replacement (SR)-containing media. As compared to other available protocols for mESCs derivation, our protocol differs in the combination of commercial availability of all reagents, technical simplicity and high efficiency. mESC lines are derived with approximately 50% efficiency (50 independent mESC lines derived from 96 blastocysts). We believe that this protocol could be a good starting point for (i) setting up the derivation of mESC lines in a laboratory and (ii) incorporating further steps to improve efficiency or adapt the protocol to other applications. The whole process (from blastocyst extraction to the freezing of mESC line) usually takes between 15 and 20 d. PMID:17487198

  15. Novel benzimidazole derivatives as expected anticancer agents.

    PubMed

    Nofal, Zienab M; Soliman, Elsyed A; Abd El-Karim, Somaia S; El Zahar, Magdy I; Srour, Aladdin M; Sethumadhavan, Shalini; Maher, Timothy J

    2011-01-01

    A series of 1-(1H-benzimidazol-2-yl)-3-(substituted)-2-propen-1-one and its 1-methyl analogues 2c-h were synthesized and cyclized with different reagents such as ethyl cyanoacetate, thiourea, hydroxylamine hydrochloride, guanidinium sulfate, methylhydrazine, phenylhydrazine and/or hydrogen peroxide in different reactions to produce pyridones 3a,b, pyrimidinethione 4a,b, isoxazole 5a,b, aminopyrimidine 6a,b, pyrazoline 7i-k and epoxy derivative 8, respectively. Acetohydrazide 10 reacted with formic acid, acetic anhydride, carbon disulfide and/or thiosemicarbazide to yield compounds 11-19. Also compound 21a,b was condensed with different monosaccharides to yield the corresponding N-glycoside Schiff's bases derivatives 22a-h, which upon treatment with acetic anhydride afforded 23a-h derivatives. The anticancer activity of some of the newly synthesized compounds was evaluated against HEPG2 (human liver carcinoma cell line) and PC12 (pheochromocytoma of the rat adrenal medulla) cells. Benzimidazole-2-isoxazole 5a derivative exhibited high potency against HEPG2 and PC12 cells. Benzimidazole chalcones 2c,e, benzimidazole mercaptoacetohydrazide 14 and benzimidazole thiosemicarbazide 15a,b derivatives gave high potency against PC12 cells. PMID:21796934

  16. Derivation of Completely Cell Culture-Derived Mice from Early-Passage Embryonic Stem Cells

    Microsoft Academic Search

    Andras Nagy; Janet Rossant; Reka Nagy; Wanda Abramow-Newerly; John C. Roder

    1993-01-01

    Several newly generated mouse embryonic stem (ES) cell lines were tested for their ability to produce completely ES cell-derived mice at early passage numbers by ES cell leftrightarrow tetraploid embryo aggregation. One line, designated R1, produced live offspring which were completely ES cell-derived as judged by isoenzyme analysis and coat color. These cell culture-derived animals were normal, viable, and fertile.

  17. Another derivation of generalized Langevin equations

    E-print Network

    Dengler, R

    2015-01-01

    The formal derivation of Langevin equations (and, equivalently Fokker-Planck equations) with projection operator techniques of Mori, Zwanzig, Kawasaki and others can well be called a pearl of theoretical physics. The derivation relies on classical mechanics, and encompasses everything an omnipotent engineer can construct from point particles and potentials: solids, liquids, liquid crystals, conductors, polymers, systems with spin-like degrees of freedom ... Einstein relations and Onsager reciprocity theorem come for free. It apparently not has widely found its way into textbooks, but has been reproduced dozens of times on the fly with many references to the literature and without adding much substantially new. Here we follow the tradition, but strive to produce a self-contained text. Furthermore, we address questions that naturally arise in the derivation. Among other things the meaning of the divergence of the Poisson brackets is explained, and the role of nonlinear damping coefficients is clarified.

  18. Electrical derivative measurement of quantum cascade lasers

    NASA Astrophysics Data System (ADS)

    Guo, Dingkai; Cheng, Liwei; Chen, Xing; Choa, Fow-Sen; Fan, Jenyu; Worchesky, Terry

    2011-02-01

    The electrical derivative characteristics of quantum cascade lasers (QCLs) are investigated to test the QCL threshold, leakage current, and possibly explore carrier transport. QCL thresholds can be identified by searching for the slope peak of the first derivative of the I-V curves and can be further confirmed with its alignment to the peak of the second derivative of the I-V curves. Leakage current in QCLs with oxide-blocked ridge waveguides and buried heterostructure (BH) waveguides are studied and compared. The oxide-blocking structures provide the lowest leakage current although the capped-mesa-BH (CMBH) QCLs provide the toughest durability under highly stressful operations. The leakage current of CMBH QCLs are also compared at different temperatures.

  19. Horava gravity with mixed derivative terms

    E-print Network

    Mattia Colombo; A. Emir Gumrukcuoglu; Thomas P. Sotiriou

    2014-10-23

    Horava gravity has been constructed so as to exhibit anisotropic scaling in the ultraviolet, as this renders the theory power-counting renormalizable. However, when coupled to matter, the theory has been shown to suffer from quadratic divergences. A way to cure these divergences is to add terms with both time and space derivatives. We consider this extended version of the theory in detail. We perform a perturbative analysis that includes all modes, determine the propagators and discuss how including mixed-derivative terms affects them. We also consider the Lifshitz scalar with mixed-derivative terms as a toy model for power counting arguments and discuss the influence of such terms on renormalizability.

  20. Second derivatives for approximate spin projection methods

    NASA Astrophysics Data System (ADS)

    Thompson, Lee M.; Hratchian, Hrant P.

    2015-02-01

    The use of broken-symmetry electronic structure methods is required in order to obtain correct behavior of electronically strained open-shell systems, such as transition states, biradicals, and transition metals. This approach often has issues with spin contamination, which can lead to significant errors in predicted energies, geometries, and properties. Approximate projection schemes are able to correct for spin contamination and can often yield improved results. To fully make use of these methods and to carry out exploration of the potential energy surface, it is desirable to develop an efficient second energy derivative theory. In this paper, we formulate the analytical second derivatives for the Yamaguchi approximate projection scheme, building on recent work that has yielded an efficient implementation of the analytical first derivatives.

  1. Theorems About Derivatives Definition 4.1 (Derivative). The derivative is given by either of the following two

    E-print Network

    Shapiro, Bruce E.

    (a) f(b) Theorem 4.2 (Mean Value Theorem (MVT)). If f is continuous on [a, b] and differentiable on (a of the mean value theorem is as follows: there is at least one point in the interval [a, b] where the slope: September 17, 2011 #12;LESSON 4. THEOREMS ABOUT DERIVATIVES 21 Figure 4.3: Illustration of the Mean Value

  2. Derived Bracket Construction and Manin Products

    NASA Astrophysics Data System (ADS)

    Uchino, Kyousuke

    2010-07-01

    We will extend the classical derived bracket construction to any algebra over a binary quadratic operad. We will show that the derived product construction is a functor given by the Manin white product with the operad of permutation algebras. As an application, we will show that the operad of prePoisson algebras is isomorphic to the Manin black product of the Poisson operad with the preLie operad. We will show that differential operators and Rota-Baxter operators are, in a sense, Koszul-dual to each other.

  3. A rigorous derivation of multicomponent diffusion laws

    E-print Network

    Zaibao Yang; Wen-An Yong; Yi Zhu

    2015-02-12

    This article is concerned with the dynamics of a mixture of gases. Under the assumption that all the gases are isothermal and inviscid, we show that the governing equations have an elegant conservation-dissipation structure. With the help of this structure, a multicomponent diffusion law is derived mathematically rigorously. This clarifies a long-standing non-uniqueness issue in the field for the first time. The multicomponent diffusion law derived here takes the spatial gradient of an entropic variable as the thermodynamic forces and satisfies a nonlinear version of the Onsager reciprocal relations.

  4. Monoterpene citral derivatives as potential antimalarials.

    PubMed

    Singh, Soni; Khandare, Reena P; Sharma, Manish; Bhasin, Virendra K; Bhat, Sujata V

    2014-03-01

    Conjugated acid derivatives containing nitrogen have been synthesized from the simple acyclic monoterpene citral, using various reactions, including Wittig, Baylis Hillman, amide and ester condensations. Similarly, amine peroxides were synthesized by subjecting citral to Mannich type reaction with amines and t-butyl hydroperoxide. Molecules 3-10 were evaluated for antimalarial activity against erythrocytic stages of chloroquine sensitive P. falciparum strain 3D7. Four derivatives displayed interesting activity with an IC50< 2.5 microM, and warrant further investigations. PMID:24689199

  5. High ethanol producing derivatives of Thermoanaerobacter ethanolicus

    DOEpatents

    Ljungdahl, Lars G. (Athens, GA); Carriera, Laura H. (Athens, GA)

    1983-01-01

    Derivatives of the newly discovered microorganism Thermoanaerobacter ethanolicus which under anaerobic and thermophilic conditions continuously ferment substrates such as starch, cellobiose, glucose, xylose and other sugars to produce recoverable amounts of ethanol solving the problem of fermentations yielding low concentrations of ethanol using the parent strain of the microorganism Thermoanaerobacter ethanolicus are disclosed. These new derivatives are ethanol tolerant up to 10% (v/v) ethanol during fermentation. The process includes the use of an aqueous fermentation medium, containing the substrate at a substrate concentration greater than 1% (w/v).

  6. Special relativity derived from spacetime magma.

    PubMed

    Greensite, Fred

    2014-01-01

    We present a derivation of relativistic spacetime largely untethered from specific physical considerations, in constrast to the many physically-based derivations that have appeared in the last few decades. The argument proceeds from the inherent magma (groupoid) existing on the union of spacetime frame components [Formula: see text] and Euclidean [Formula: see text] which is consistent with an "inversion symmetry" constraint from which the Minkowski norm results. In this context, the latter is also characterized as one member of a class of "inverse norms" which play major roles with respect to various unital [Formula: see text]-algebras more generally. PMID:24959889

  7. Effects of thienodiazepine derivatives on human sleep as compared to those of benzodiazepine derivatives

    Microsoft Academic Search

    Yoichi Nakazawa; Makoto Kotorii; Masachika Ohshima; Shuichi Horikawa; Hisayuki Tachibana

    1975-01-01

    The effects of new thienodiazepine derivatives, such as clotiazepam and Y-7131, on normal human sleep were investigated on 5 subjects and compared to those of benzodiazepine derivatives, such as diazepam and nitrazepam. REM sleep was significantly decreased only with 2 mg of Y-7131 and rebound elevation of REM sleep did not follow in recovery 1 and 2 nights. By using

  8. Bernard Jacquemin, A derivational rephrasing experiment for question answering A derivational rephrasing experiment for question answering

    E-print Network

    Paris-Sud XI, Université de

    Bernard Jacquemin, A derivational rephrasing experiment for question answering A derivational rephrasing experiment for question answering Bernard Jacquemin Université de Haute Alace / CREM EA3476 10 rue, preserving the initial meaning; its impact on the re- sults coping with a real issue, ie a question answering

  9. Nonlinear Frechet derivative and its De Wolf approximation

    E-print Network

    Wu, Ru-Shan

    2012-01-01

    We introduce and derive the nonlinear Frechet derivative for the acoustic wave equation. It turns out that the high order Frechet derivatives can be realized by consecutive applications of the scattering operator and a ...

  10. Barriers to growth in the US real estate derivatives market

    E-print Network

    Venter, Jani

    2007-01-01

    Commercial real estate is an important asset class but it does not yet have a well-developed derivatives market in the United States. A derivative is a contract that derives its value from an underlying index or asset. ...

  11. Exploiting Sparsity in Unconstrained Optimization Without Derivatives

    E-print Network

    Toint, Philippe

    , function evaluations and speed. Keywords: derivative-free optimization, interpolation models, trust discuss a method combining the use of interpolation polynomials and trust- region techniques to minimize methods to model the objective function and their com- bination with trust-region techniques. This class

  12. Pricing Exotic Derivatives Using Regret Minimization

    E-print Network

    Mansour, Yishay

    . An important type of derivative is an option, which is a financial instrument that allows its holder to buy that are traded or developed to meet particular financial needs. Such options are collectively known as exotic University, Tel Aviv, Israel {eyalgofe,mansour}@post.tau.ac.il Abstract. We price various financial

  13. Deriving Optimal Thresholds for Active Fire Detection

    Microsoft Academic Search

    Soo Chin Liew; Agnes Lim; Leong Keong Kwoh

    2006-01-01

    In this paper, the optimal threshold for fire detection is derived based on the probability density functions of the fire and background pixels. The threshold values and the commission and omission errors are computed according to several detection criteria: maximum likelihood, null-hypothesis testing, and minimum cost. This statistical approach enables the determination of optimal threshold value according to the specific

  14. Higher Derivative D-brane Couplings

    E-print Network

    Guo, Guangyu

    2012-10-19

    supersymmetry. In the third part, we obtain the higher derivative D-brane action by using both linearized T-duality and string disc amplitude computation. We evaluate disc amplitude of one R-R field C^(p-3) and two NS-NS fields in the presence of a single Dp...

  15. A derivation of Abel's name by Postnikov

    E-print Network

    Kassel, Christian

    A derivation of Abel's name by Postnikov Abel --# Abel son of Adam and Eva # # # # Brother Cain, Editions Mir, Moscou 1985). 0 #12; Abel Conference Oslo (3--8.6.2001) Action of the absolute Galois group. Inverse system of braided categories: # C = lim #- {· · · # C/I 3 # C/I 2 # C/I} Example. Let R

  16. Chemiluminescence of indole and its derivatives

    NASA Astrophysics Data System (ADS)

    Vasil'ev, Rostislav F.; Trofimov, A. V.; Tsaplev, Yuri B.

    2010-02-01

    The results of studies on chemiluminescence of indole and its derivatives are critically analyzed. It is shown that chemical transformations of indoles lead, depending on the structure and experimental conditions, to various electronically excited products and emission of light. Many reactions considered are used as a basis for highly sensitive methods for detection of indoles in biology, medicine, ecology and forensics.

  17. DAMTP 9269 Grassmann Mechanics, Multivector Derivatives and

    E-print Network

    Cambridge, University of

    mathematics that can be carried out with geometric (Clifford) algebra (Hestenes & Sobczyk, 1984 of the multivector derivative (Hestenes & Sobczyk, 1984). The point to stress is that as a result of the translation of (Hestenes & Sobczyk, 1984), so that vectors are written in lower case, and multivectors in upper case

  18. Ecosystem Services Derived from Headwater Catchments

    EPA Science Inventory

    We used data from the USEPA?s wadeable streams assessment (WSA), US Forest Service?s forest inventory and analysis (FIA), and select USFS experimental forests (EF) to investigate potential ecosystems services derived from headwater catchments. C, N, and P inputs to these catchmen...

  19. Entropy theory for derivation of infiltration equations

    NASA Astrophysics Data System (ADS)

    Singh, Vijay P.

    2010-03-01

    An entropy theory is formulated for modeling the potential rate of infiltration in unsaturated soils. The theory is composed of six parts: (1) Shannon entropy, (2) principle of maximum entropy (POME), (3) specification of information on infiltration in terms of constraints, (4) maximization of entropy in accordance with POME, (5) derivation of the probability distribution of infiltration, and (6) derivation of infiltration equations. The theory is illustrated with the derivation of six infiltration equations commonly used in hydrology, watershed management, and agricultural irrigation, including Horton, Kostiakov, Philip two-term, Green-Ampt, Overton, and Holtan equations, and the determination of the least biased probability distributions of these infiltration equations and their entropies. The theory leads to the expression of parameters of the derived infiltration equations in terms of measurable quantities (or information), called constraints, and in this sense these equations are rendered nonparametric. Furthermore, parameters of these infiltration equations can be expressed in terms of three measurable quantities: initial infiltration, steady infiltration, and soil moisture retention capacity. Using parameters so obtained, infiltration rates are computed using these six infiltration equations and are compared with field experimental observations reported in the hydrologic literature as well as the rates computed using parameters of these equations obtained by calibration. It is found that infiltration parameter values yielded by the entropy theory are good approximations.

  20. Biofuels and bio-products derived from

    E-print Network

    Ginzel, Matthew

    NEED Biofuels and bio- products derived from lignocellulosic biomass (plant materials) are part improve the energy and carbon efficiencies of biofuels production from a barrel of biomass using chemical and thermal catalytic mechanisms. The Center for Direct Catalytic Conversion of Biomass to Biofuels IMPACT

  1. Trading Volume in Models of Financial Derivatives

    Microsoft Academic Search

    Sam Howison; David lamper

    2000-01-01

    This paper develops a subordinated stochastic process model for the asset price, where the directing process is identified as information. Motivated by recent empirical and theoretical work, we make use of the under-used market statistic of transaction count as a suitable proxy for the information flow. An option pricing formula is derived, and comparisons with stochastic volatility models are drawn.

  2. Radon-Nikodym Derivatives of Gaussian Measures

    Microsoft Academic Search

    L. A. Shepp

    1966-01-01

    We give simple necessary and sufficient conditions on the mean and covariance for a Gaussian measure to be equivalent to Wiener measure. This was formerly an unsolved problem [26]. An unsolved problem is to obtain the Radom-Nikodym derivative $d\\\\mu\\/d\\\

  3. LOGARITHMIC DERIVATIVES AND GENERALIZED DYNKIN OPERATORS.

    E-print Network

    Paris-Sud XI, Université de

    directions and point of views (free Lie algebras, Hopf algebras, Rota-Baxter algebras...), all of them knownLOGARITHMIC DERIVATIVES AND GENERALIZED DYNKIN OPERATORS. FR´ED´ERIC MENOUS AND FR´ED´ERIC PATRAS Abstract. Motivated by a recent surge of interest for Dynkin oper- ators in mathematical physics

  4. Alternative Derivations for the Poisson Integral Formula

    ERIC Educational Resources Information Center

    Chen, J. T.; Wu, C. S.

    2006-01-01

    Poisson integral formula is revisited. The kernel in the Poisson integral formula can be derived in a series form through the direct BEM free of the concept of image point by using the null-field integral equation in conjunction with the degenerate kernels. The degenerate kernels for the closed-form Green's function and the series form of Poisson…

  5. Sol-Gel Derived Hafnia Coatings

    NASA Technical Reports Server (NTRS)

    Feldman, Jay D.; Stackpoole, Mairead; Blum, Yigal; Sacks, Michael; Ellerby, Don; Johnson, Sylvia M.; Venkatapathy, Ethiras (Technical Monitor)

    2002-01-01

    Sol-gel derived hafnia coatings are being developed to provide an oxidation protection layer on ultra-high temperature ceramics for potential use in turbine engines (ultra-efficient engine technology being developed by NASA). Coatings using hafnia sol hafnia filler particles will be discussed along with sol synthesis and characterization.

  6. Developing market for waste-derived fuel

    Microsoft Academic Search

    1984-01-01

    Markets are developing for products such as closely specified fuel, graded compost and clean ferrous metal and the company in question is aiming to produce these from waste treatment projects. The plant used for the waste derived fuel consists of equipment such as plant feeders, a vertical hammer mill, a ballistic classifier, magnetic separators, shredders, dryers a densifying unit and

  7. Derivation of physically motivated wind speed scales

    Microsoft Academic Search

    Nikolai Dotzek

    2009-01-01

    A class of new wind speed scales is proposed in which the relevant scaling factors are derived from physical quantities like mass flux density, energy density (pressure), or energy flux density. Hence, they are called Energy- or E-scales, and can be applied to wind speeds of any intensity. It is shown that the Mach scale is a special case of

  8. Calculus Concepts Using Derive For Windows

    E-print Network

    Craven, Thomas C.

    Calculus Concepts Using Derive For Windows Ralph S. Freese and David A. Stegenga Professors-471-37228-5 This publication was typeset using AMS-LATEX, the American Mathematical Society's TEX macro system, and LATEX2 and Mathematica, are very powerful tools for doing calculus. They are capable of doing exact computations

  9. Calculus Concepts Using Derive For Windows

    E-print Network

    Freese, Ralph S.

    Calculus Concepts Using Derive For Windows Ralph S. Freese and David A. Stegenga Professors. This publication was typeset using AMS-LATEX, the American Mathe- matical Society's TEX macro system, and LATEX2. #12;Contents Preface ix Calculus Reform and Computers . . . . . . . . . . . . . . . . . . . ix 0

  10. CONFIGURATION INTERACTION ENERGY DERIVATIVES Jack Simons

    E-print Network

    Simons, Jack

    CONFIGURATION INTERACTION ENERGY DERIVATIVES Jack Simons Chemistry Department University of Utah. Simons (eds.), Geometrica/ De,ivatives of Energy Surfaces and Mo/ecu/ar Properties, 27-34. ~ 1986 by D. Reide/ Pub/ishing Cor.wany. #12;28 J. SIMONS be taken to obey the generalized Brillouin theorem2 (GBT

  11. Parsing with Derivatives (Yacc is Dead)

    E-print Network

    Might, Matt

    Parsing with Derivatives (Yacc is Dead) Matt Might & David Darais University of Utah matt" | "Sep" | "Oct" | "Nov" | "Dec" Chunked-Body = *chunk last-chunk trailer CRLF chunk = chunk-size [ chunk = (2base64-char "==") / (3base64-char "=") body = "(" (body-type-1part / body-type-mpart) ")" body

  12. Geometric Derivation of Radial Acceleration Magnitude.

    ERIC Educational Resources Information Center

    Kraft, David W.; Motz, Lloyd

    1995-01-01

    Standard treatments of uniform circular motion generally employ a combination of geometric and kinematic arguments to obtain the magnitude of radial acceleration. Presents a novel approach to the geometric portion of the derivation that uses the property that vectors can be translated parallel to themselves. (JRH)

  13. Synthesis of hydroxy derivatives of limonene

    NASA Astrophysics Data System (ADS)

    Ardashov, O. V.; Volcho, K. P.; Salakhutdinov, N. F.

    2014-04-01

    Synthetic routes to mono-, di- and trihydroxy derivatives of limonene are presented. Emphasis is given to the problems of regio- and stereoselectivity of transformations. Data on the isolation from natural sources and on the biological activities of the title compounds are given. The bibliography includes 107 references.

  14. Speaker Recognition Using Acoustically Derived Units

    E-print Network

    word in the database's vocabulary. Acoustic segmentation is performed using dynamic pro- gramming where1 Speaker Recognition Using Acoustically Derived Units Brett R. Wildermoth & Kuldip K. Paliwal to their restrictive nature. It is the goal of this paper to propose the use of acoustic based units as a means

  15. Wind information derived from hot air

    E-print Network

    Haak, Hein

    Wind information derived from hot air balloon flights for use in short term wind forecasts E Introduction/Motivation Hot air balloons as wind measuring device Setup of nested HIRLAM models Results · Three, The Nertherlands #12;Hot air balloon ·Displacement/time unit = wind speed ·Vertical resolution 30m ·Inertia (500 kg

  16. The derivatives of the H-function

    NASA Astrophysics Data System (ADS)

    Viik, Tonu

    1990-03-01

    A method to find the derivatives of the H-function is proposed. The method starts from Sobolev's (1972) formula for the differential of the H-function. The quality of the resulting formulas is discussed, indicating ways to improve the results of their application.

  17. Bone marrow-derived stem cells and \\

    Microsoft Academic Search

    A. Hüttmann; C. L. Li; U. Dührsen

    2003-01-01

    Studies describing plasticity of somatic stem cells have become a focus of interest because clinical applications in the treatment of degenerative diseases would be at hand. In particular, bone marrow-derived cells and their potential to contribute to skeletal and cardiac muscle, liver, neurons and epithelium have recently been studied extensively. Nevertheless, results of these studies have not always been consistent

  18. Derivatives and the Graphs of Functions Microworld

    NSDL National Science Digital Library

    James White

    2004-11-01

    The purpose of this Microworld is to experiment with some of the general applications of the derivative to the study of the behavior of functions. This includes their critical behavior, their local extrema, regions of monotonicity (increasing or decreasing), and their inflection points.

  19. Hedging derivative securities with genetic programming

    Microsoft Academic Search

    1999-01-01

    Abstract,One of the most recent applications of GP to finance is to use genetic program- ming to derive option pricing formulas. Earlier studies take the Black?Scholes model as the true model and use the artificial data generated by it to train and to test GP. The aim of this paper is to provide some initial evidence of the empirical relevance

  20. The Schwarzian derivative for harmonic mappings

    Microsoft Academic Search

    Martin Chuaqui; Peter Duren; Brad Osgood

    2003-01-01

    The Schwarzian derivative of an analytic function is a basic tool in complex analysis. It appeared as early as 1873, when H. A. Schwarz sought to generalize the Schwarz-Christo el formula to conformal mappings of polygons bounded by circular arcs. More recently, Nehari [5, 6, 7] and others have developed important criteria for global univalence in terms of the Schwarzian

  1. Singlet exciton fission in a hexacene derivative.

    PubMed

    Lee, Jiye; Bruzek, Matthew J; Thompson, Nicholas J; Sfeir, Matthew Y; Anthony, John E; Baldo, Marc A

    2013-03-13

    Hexacene, an acene with six benzene rings, is notable for its exceptionally small triplet energy, around one third of the singlet energy. Herein, singlet fission, i.e., conversion of a singlet exciton into two triplets, is demonstrated in a thin film of hexacene derivative, employing both transient absorption spectroscopy and magnetic field effects on photocurrent. PMID:23293054

  2. Amino acid and peptide derivatives of fullerene

    Microsoft Academic Search

    M. E. Vol'pin; Z. N. Parnes; V. S. Romanova

    1998-01-01

    A general method for the synthesis of amino acid and peptide derivatives of fullerene (ADF) was developed, and the physicochemical\\u000a properties of the compounds obtained were studied. ADF were shown to penetrate into liposomes and to exhibit adjuvant properties\\u000a and antiviral activity.

  3. Embryogenesis in callus derived from rice microspores

    Microsoft Academic Search

    A. D. Genovesi; C. W. Magill

    1982-01-01

    Differentiating calli derived from rice (Oryza sativa L.) microspores were examined histologically. Shoot and root meristems were observed to be arising by both organogenesis as well as embryogenesis. Embryoid attachment to callus (as well as other embryoids) was at the scutellum adjacent to the mesocotyl and radicle. These observations could be interpreted as an indication of the totipotent plasticity of

  4. UNDERSTANDING, DERIVING, AND COMPUTING BUFFER CAPACITY

    EPA Science Inventory

    Derivation and systematic calculation of buffer capacity is a topic that seems often to be neglected in chemistry courses and given minimal treatment in most texts. However, buffer capacity is very important in the chemistry of natural waters and potable water. It affects corro...

  5. Deriving exact predictions from the cascade model

    Microsoft Academic Search

    F. Gregory Ashby

    1982-01-01

    Discusses J. L. McClelland's cascade model and demonstrates that the model does not have a well-defined RT distribution function because it always predicts a nonzero probability that a response will never occur. By conditioning on the event that a response does occur, RT density and distribution functions are derived, thus allowing most RT statistics to be computed directly and eliminating

  6. SATELLITE-DERIVED CLOUD PROPERTIES OVER CHINA

    Microsoft Academic Search

    K. Kawamoto; T. Hayasaka; WG VII

    Low-level water cloud (cloud top temperature more than 273K) properties such as the optical depth, particle radius, and vertically- integrated droplet number concentration are derived from satellite remote sensing technique with Advanced High Resolution Radiometer (AVHRR) over the East Asia, mainly China area. Their annual mean characteristics thus obtained are consistent with what the Twomey effect indicates, showing larger optical

  7. Emulating Multivariate Output with Derivative Information

    E-print Network

    Oakley, Jeremy

    of derivatives in emulation . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.2 The Radiation Transport model each output of the radiation transport model independently . . 12 2.3.1 Emulators with all 100 runs.3 Multivariate emulation of the radiation transport model . . . . . . . . . . . 27 4 Calibration of the Radiation

  8. Simple Derivation of the Lindblad Equation

    ERIC Educational Resources Information Center

    Pearle, Philip

    2012-01-01

    The Lindblad equation is an evolution equation for the density matrix in quantum theory. It is the general linear, Markovian, form which ensures that the density matrix is Hermitian, trace 1, positive and completely positive. Some elementary examples of the Lindblad equation are given. The derivation of the Lindblad equation presented here is…

  9. Dynamic derivative UV spectroscopy for combustion monitoring

    NASA Astrophysics Data System (ADS)

    Sassenscheid, Karsten; Klocke, Ulrich; Marb, C.; Riedel, H.; Schmidtke, Gerhard; Tacke, Maurus

    1999-01-01

    Derivative UV-absorption spectroscopy is a powerful spectroscopic technique for multicomponent gas analysis, particularly in combustion and process controlling applications. It offers enhanced selectivity and sensitivity compared to conventional techniques. We here report on a test of a special system with optical derivative generation in a waste incineration plant. Gas analysis is performed by transmission spectroscopy. A deuterium lamp is used as UV- source. Spectroscopic filtering is provided by a special grating monochromator. The grating is mounted on a galvanometer scanner, thus allowing a computer controlled wavelength scan and modulation. Signal analysis is performed with lock-in amplifier. The is from of detection for derivative spectra with a movable optical component is the origin of the term DYnamic Derivative Spectroscopy (DDS). The performance of this spectroscopic technique was demonstrated in a measurement campaign at a municipal solid waste incineration plant. The sensitivity for relevant gases is blow ppm level with an optical cell length of 10cm. The basics of the DDS and its performance will be explained, and data on NO, SO2 and NO2 will be reported.

  10. CYTOPATHOLOGY Computer-Derived Nuclear Features Compared

    E-print Network

    Street, Nick

    172 CANCER CYTOPATHOLOGY Computer-Derived Nuclear Features Compared with Axillary Lymph Node Status of axillary lymph nodes and may obviate the need for routine axillary lymph node dissection. Cancer (Cancer for Breast Carcinoma Prognosis BACKGROUND. Both axillary lymph node involvement and tumor anaplasia, as

  11. Deriving Realtime Monitors System Requirements Documentation

    E-print Network

    Peters, Dennis

    -- or mission--critical systems, good engineering practice dictates that a clear, precise and unam­ biguousDeriving Real­time Monitors from System Requirements Documentation Dennis K. Peters CRL, Mc against the specification, a monitor, be automatically de­ rived from the requirements documentation

  12. Leading Edge Democracy Derived? New Trajectories

    E-print Network

    Leading Edge Commentary Democracy Derived? New Trajectories in Pluripotent Stem Cell Research of stem cell research? Here, coauthorship networks of stem cell research articles and analysis of cell lines used in stem cell research indicate that hiPSCs are not replacing human embryonic stem cells

  13. Robust Derivation of Risk Reduction Strategies

    NASA Technical Reports Server (NTRS)

    Richardson, Julian; Port, Daniel; Feather, Martin

    2007-01-01

    Effective risk reduction strategies can be derived mechanically given sufficient characterization of the risks present in the system and the effectiveness of available risk reduction techniques. In this paper, we address an important question: can we reliably expect mechanically derived risk reduction strategies to be better than fixed or hand-selected risk reduction strategies, given that the quantitative assessment of risks and risk reduction techniques upon which mechanical derivation is based is difficult and likely to be inaccurate? We consider this question relative to two methods for deriving effective risk reduction strategies: the strategic method defined by Kazman, Port et al [Port et al, 2005], and the Defect Detection and Prevention (DDP) tool [Feather & Cornford, 2003]. We performed a number of sensitivity experiments to evaluate how inaccurate knowledge of risk and risk reduction techniques affect the performance of the strategies computed by the Strategic Method compared to a variety of alternative strategies. The experimental results indicate that strategies computed by the Strategic Method were significantly more effective than the alternative risk reduction strategies, even when knowledge of risk and risk reduction techniques was very inaccurate. The robustness of the Strategic Method suggests that its use should be considered in a wide range of projects.

  14. Two-point derivative dispersion relations

    NASA Astrophysics Data System (ADS)

    Ferreira, Erasmo; Sesma, Javier

    2013-03-01

    A new derivation is given for the representation, under certain conditions, of the integral dispersion relations of scattering theory through local forms. The resulting expressions have been obtained through an independent procedure to construct the real part and consist of new mathematical structures of double infinite summations of derivatives. In this new form the derivatives are calculated at the generic value of the energy E and separately at the reference point E = m that is the lower limit of the integration. This new form may be more interesting in certain circumstances and directly shows the origin of the difficulties in convergence that were present in the old truncated forms called standard-derivative dispersion relations (DDR). For all cases in which the reductions of the double to single sums were obtained in our previous work, leading to explicit demonstration of convergence, these new expressions are seen to be identical to the previous ones. We present, as a glossary, the most simplified explicit results for the DDR's in the cases of imaginary amplitudes of forms (E/m)?[ln (E/m)]n that cover the cases of practical interest in particle physics phenomenology at high energies. We explicitly study the expressions for the cases with ? negative odd integers, that require identification of cancelation of singularities, and provide the corresponding final results.

  15. Deriving Safety Requirements for Autonomous Systems

    Microsoft Academic Search

    Robert Alexander; Tim Kelly; Nicola Herbert

    In any safety engineering effort, deriving safety requirements is a key activity. Doing this for autonomous systems (AS) is challenging. However, several existing techniques can be pulled together to create a reasonable approach The risk of interaction between implemented requirements remains a concern, as does ambiguity about the appropriate boundary of the AS system. We believe these issues can be

  16. Curcumin derivatives as HIV-1 protease inhibitors

    SciTech Connect

    Sui, Z.; Li, J.; Craik, C.S.; Ortiz de Montellano, P.R. [Univ. of California, San Francisco, CA (United States)

    1993-12-31

    Curcumin, a non-toxic natural compound from Curcuma longa, has been found to be an HIV-1 protease inhibitor. Some of its derivatives were synthesized and their inhibitory activity against the HIV-1 protease was tested. Curcumin analogues containing boron enhanced the inhibitory activity. At least of the the synthesized compounds irreversibly inhibits the HIV-1 protease.

  17. Mathematical Relationships Derived from Biodiesel Fuels

    Microsoft Academic Search

    A. Demirbas

    2007-01-01

    The objective of this study was to estimate mathematical relationships derived from biodiesel fuels from various vegetable oils by non-catalytic supercritical methanol and ethanol method. The vegetable oils are all extremely viscous with viscosities ranging from 10 to 20 times greater than petroleum diesel fuel. The aim of the transesterification process is to lower the viscosity of the oil. Methyl

  18. Introduction Aliphatic polyesters derived from renewable

    E-print Network

    , there are also opportunities to derive lactones from biomass, which can then be converted to a wide range IV instrument using a DHB/NaCl matrix in a sample:matrix ratio of 1:1. The matrix was prepared

  19. Influence of Different Iodide Salts on the Performance of Dye-Sensitized Solar Cells Containing Phosphazene-Based Nonvolatile Electrolytes

    E-print Network

    Influence of Different Iodide Salts on the Performance of Dye-Sensitized Solar Cells Containing studied as components of dye- sensitized solar cells (DSSCs). Electrolytes based on hexa. Introduction Dye-sensitized solar cells (DSSCs) are promising solar conversion devices that can achieve >10

  20. Thermal degradation behavior of the compound containing phosphaphenanthrene and phosphazene groups and its flame retardant mechanism on epoxy resin

    Microsoft Academic Search

    Lijun Qian; Longjian Ye; Yong Qiu; Shuren Qu

    2011-01-01

    The flame retardant epoxy resin has been prepared by mixing the flame retardant additive hexa-(phosphaphenanthrene-hydroxyl-methyl-phenoxyl)-cyclotriphosphazene (HAP-DOPO) into diglycidyl ether of bisphenol-A (DGEBA). After cured by 4,4?-Diamino-diphenyl sulfone (DDS), the flame retardant properties of thermosets were characterized by the limited oxygen index (LOI), UL-94 test and cone calorimeter. The results show the lower peak of heat release rate (pk-HRR), the higher

  1. Early Time Points Perfusion Imaging: Relative Time of Arrival, Maximum Derivatives and Fractional Derivatives

    PubMed Central

    Kwong, Kenneth K.; Wu, Ona; Chan, Suk-Tak; Nelissen, Koen; Kholodov, Mykhaylo; Chesler, David A.

    2011-01-01

    Time of arrival (TOA) of a bolus of contrast agent to the tissue voxel is a reference time point critical for the Early Time Points Perfusion Imaging Method (ET) to make relative cerebral blood flow (rCBF) maps. Due to the low contrast to noise (CNR) condition at TOA, other useful reference time points known as relative time of arrival data points (rTOA) are investigated. Candidate rTOA's include the time to reach the maximum derivative, the maximum second derivative, and the maximum fractional derivative. Each rTOA retains the same relative time distance from TOA for all tissue flow levels provided that ET's basic assumption is met, namely, no contrast agent has a chance to leave the tissue before the time of rTOA. The ET's framework insures that rCBF estimates by different orders of the derivative are theoretically equivalent to each other and monkey perfusion imaging results supported the theory. In rCBF estimation, maximum values of higher order fractional derivatives may be used to replace the maximum derivative which runs a higher risk of violating ET's assumption. Using the maximum values of the derivative of orders ranging from 1 to 1.5 to 2, estimated rCBF results were found to demonstrate a gray-white matter ratio of approximately 3, a number consistent with flow ratio reported in the literature. PMID:21600995

  2. Photophysics and photochemistry of naphthoxazinone derivatives.

    PubMed

    Nonell, Santi; Ferreras, Lourdes R; Cañete, Alvaro; Lemp, Else; Günther, German; Pizarro, Nancy; Zanocco, Antonio L

    2008-07-18

    The photophysics and photochemistry of a series of naphthoxazinones have been studied using a combination of methods ranging from steady-state and time-resolved spectroscopic techniques to product analysis. The photophysics of naphthoxazinone derivatives is very dependent on the structure: phenanthrene-like compounds exhibit higher fluorescence quantum yield than the less aromatic anthracene-like homologous. The latter, exhibit a substantial degree of charge transfer in the excited singlet state. These compounds are fairly photostable in the absence of additives, yielding a single photoproduct arising from the triplet state. The presence of electron donors such as amines increases the photoconsumption quantum yield and changes the product distribution, the primary photoproduct being a dihydronaphthoxazinone that photoreacts further yielding ultimately an oxazoline derivative. PMID:18553978

  3. Hydrocarbon and nonhydrocarbon derivatives of cyclopropane

    NASA Technical Reports Server (NTRS)

    Slabey, Vernon A; Wise, Paul H; Gibbons, Louis C

    1953-01-01

    The methods used to prepare and purify 19 hydrocarbon derivatives of cyclopropane are discussed. Of these hydrocarbons, 13 were synthesized for the first time. In addition to the hydrocarbons, six cyclopropylcarbinols, five alkyl cyclopropyl ketones, three cyclopropyl chlorides, and one cyclopropanedicarboxylate were prepared as synthesis intermediates. The melting points, boiling points, refractive indices, densities, and, in some instances, heats of combustion of both the hydrocarbon and nonhydrocarbon derivatives of cyclopropane were determined. These data and the infrared spectrum of each of the 34 cyclopropane compounds are presented in this report. The infrared absorption bands characteristic of the cyclopropyl ring are discussed, and some observations are made on the contribution of the cyclopropyl ring to the molecular refractions of cyclopropane compounds.

  4. Polyphenol derivatives - potential regulators of neutrophil activity.

    PubMed

    Drábiková, Katarína; Pere?ko, Tomáš; Nosá?, Radomír; Harmatha, Juraj; Smidrkal, Jan; Jan?inová, Viera

    2012-06-01

    The study provides new information on the effect of natural polyphenols (derivatives of stilbene - resveratrol, pterostilbene, pinosylvin and piceatannol and derivatives of ferulic acid - curcumin, N-feruloylserotonin) on the activity of human neutrophils in influencing oxidative burst. All the polyphenols tested were found to reduce markedly the production of reactive oxygen species released by human neutrophils on extra-and intracellular levels as well as in cell free system. Moreover, pinosylvin, curcumin, N-feruloylserotonin and resveratrol decreased protein kinase C activity involved in neutrophil signalling and reactive oxygen species production. Our results suggest that due to their anti-neutrophil activity, the polyphenols tested might be attractive candidates in therapeutic development. PMID:23118589

  5. Novel cajaninstilbene acid derivatives as antibacterial agents.

    PubMed

    Geng, Zhi-Zhong; Zhang, Jian-Jun; Lin, Jing; Huang, Mei-Yan; An, Lin-Kun; Zhang, Hong-Bin; Sun, Ping-Hua; Ye, Wen-Cai; Chen, Wei-Min

    2015-07-15

    Discovery of novel antibacterial agents with new structural scaffolds that combat drug-resistant pathogens is an urgent task. Cajaninstilbene acid, which is isolated from pigeonpea leaves, has shown antibacterial activity. In this study, a series of cajaninstilbene acid derivatives were designed and synthesized. The antibacterial activities of these compounds against gram-negative and gram-positive bacteria, as well as nine strains of methicillin-resistant staphylococcus aureus (MRSA) bacteria are evaluated?and the related structure-activity relationships are discussed. Assays suggest that some of the synthetic cajaninstilbene acid derivatives exhibit potent antibacterial activity against gram-positive bacterial strains and MRSA. Among these compounds, 5b, 5c, 5j and 5k show better antibacterial activity than the positive control compounds. The results of MTT assays illustrate the low cytotoxicity of the active compounds. PMID:26093280

  6. Tooth-derived bone graft material

    PubMed Central

    Kim, Young-Kyun; Lee, Junho; Kim, Kyung-Wook; Murata, Masaru; Akazawa, Toshiyuki; Mitsugi, Masaharu

    2013-01-01

    With successful extraction of growth factors and bone morphogenic proteins (BMPs) from mammalian teeth, many researchers have supported development of a bone substitute using tooth-derived substances. Some studies have also expanded the potential use of teeth as a carrier for growth factors and stem cells. A broad overview of the published findings with regard to tooth-derived regenerative tissue engineering technique is outlined. Considering more than 100 published papers, our team has developed the protocols and techniques for processing of bone graft material using extracted teeth. Based on current studies and studies that will be needed in the future, we can anticipate development of scaffolds, homogenous and xenogenous tooth bone grafts, and dental restorative materials using extracted teeth. PMID:24471027

  7. Synthesis and cytotoxicity of longistylin C derivatives.

    PubMed

    Shan, Yan; Hong, Ting; Wang, Yan-Fei; Zhang, Nen-Ling; Yu, Bo; Lu, Yu; Qiu, Sheng-Xiang

    2015-04-01

    The present study was designed to identify potent anti-tumor compounds from a series of new longistylin C derivatives. Ten longistylin C derivatives were synthesized and their structures were confirmed by (1)H NMR, MS, and elemental analyses. Their cytotoxicity in vitro against three human cancer cell lines (A549, HepG2, and MCF-7) were evaluated by the MTT assay. Among these compounds, DT-6 and DT-9 displayed much better cytotoxicity against A549, HepG2, and MCF-7 cells, DT-1 exhibited selective cytotoxicity against HepG2, and the structure-activity relationships were investigated. In conclusion, Compounds DT-6 and DT-9 may serve as potential lead compounds for the discovery of new anti-cancer drugs. PMID:25908631

  8. ?-Ionone derived chalcones as potent antiproliferative agents.

    PubMed

    Sharma, Vishal; Chaudhary, Ashun; Arora, Saroj; Saxena, Ajit K; Ishar, Mohan Paul S

    2013-11-01

    A series of ?-ionone derived chalcones were evaluated for cytotoxic activity against various human cancer cell lines using SRB dye assay. All the compounds displayed moderate to high cytotoxic effect against almost all the cancer cell lines. The results also revealed the effect of substituents of the aromatic ring on their inhibitory potential. In general, compounds bearing electron withdrawing groups such as nitro, fluoro, chloro and bromo showed more inhibitory potential than those bearing electron donating groups. The nitro substituted compound (7h) showed comparatively more inhibitory potential than other derivatives, therefore, it was further investigated for observing its effect on cell morphology in Chinese hamster ovary (CHO) cells by using phase contrast imaging, cell cycle analysis and annexin-FITC apoptosis assay. The treated cells exhibited the characteristics of apoptosis i.e. cell shrinkage, chromatin condensation and nuclear fragmentation, and induced the inhibition of cell proliferation by arresting the cells at G0 phase. PMID:24056146

  9. Novel harmine derivatives for tumor targeted therapy.

    PubMed

    Li, Siwen; Wang, Aqin; Gu, Fan; Wang, Zhaohui; Tian, Caiping; Qian, Zhiyu; Tang, Liping; Gu, Yueqing

    2015-04-20

    Harmine is a beta-carboline alkaloid found in medicinal plant PeganumHarmala, which has served as a folk anticancer medicine. However, clinical applications of harmine were limited by its low pharmacological effects and noticeable neurotoxicity. In this study, we modified harmine to increase the therapeutic efficacy and to decrease the systemic toxicity. Specifically, two tumor targeting harmine derivatives 2DG-Har-01 and MET-Har-02 were synthesized by modifying substituent in position-2, -7 and -9 of harmine ring with two different targeting group2-amino-2-deoxy-D-glucose (2DG) and Methionine (Met), respectively. Their therapeutic efficacy and toxicity were investigated both in vitro and in vivo. Results suggested that the two newharmine derivatives displayed much higher therapeutic effects than non-modified harmine. In particular, MET-Har-02 was more potent than 2DG-Har-01 with promising potential for targeted cancer therapy. PMID:25940702

  10. Febrifugine derivative antimalarial activity: quantum mechanical predictors.

    PubMed

    Autreto, Pedro Alves da Silva; Lavarda, Francisco Carlos

    2008-01-01

    Plasmodium falciparum resistant strain development has encouraged the search for new antimalarial drugs. Febrifugine is a natural substance with high activity against P. falciparum presenting strong emetic property and liver toxicity, which prevent it from being used as a clinical drug. The search for analogues that could have a better clinical performance is a current topic. We aim to investigate the theoretical electronic structure by means of febrifugine derivative family semi-empirical molecular orbital calculations, seeking the electronic indexes that could help the design of new efficient derivatives. The theoretical results show there is a clustering in well-defined ranges of several electronic indexes of the most selective molecules. The model proposed for achieving high selectivity was tested with success. PMID:18327483

  11. Novel harmine derivatives for tumor targeted therapy

    PubMed Central

    Gu, Fan; Wang, Zhaohui; Tian, Caiping; Qian, Zhiyu; Tang, Liping; Gu, Yueqing

    2015-01-01

    Harmine is a beta-carboline alkaloid found in medicinal plant PeganumHarmala, which has served as a folk anticancer medicine. However, clinical applications of harmine were limited by its low pharmacological effects and noticeable neurotoxicity. In this study, we modified harmine to increase the therapeutic efficacy and to decrease the systemic toxicity. Specifically, two tumor targeting harmine derivatives 2DG-Har-01 and MET-Har-02 were synthesized by modifying substituent in position-2, -7 and -9 of harmine ring with two different targeting group2-amino-2-deoxy-D-glucose (2DG) and Methionine (Met), respectively. Their therapeutic efficacy and toxicity were investigated both in vitro and in vivo. Results suggested that the two newharmine derivatives displayed much higher therapeutic effects than non-modified harmine. In particular, MET-Har-02 was more potent than 2DG-Har-01 with promising potential for targeted cancer therapy. PMID:25940702

  12. Bacterial degradation of chlorophenols and their derivatives

    PubMed Central

    2014-01-01

    Chlorophenols (CPs) and their derivatives are persistent environmental pollutants which are used in the manufacture of dyes, drugs, pesticides and other industrial products. CPs, which include monochlorophenols, polychlorophenols, chloronitrophenols, chloroaminophenols and chloromethylphenols, are highly toxic to living beings due to their carcinogenic, mutagenic and cytotoxic properties. Several physico-chemical and biological methods have been used for removal of CPs from the environment. Bacterial degradation has been considered a cost-effective and eco-friendly method of removing CPs from the environment. Several bacteria that use CPs as their sole carbon and energy sources have been isolated and characterized. Additionally, the metabolic pathways for degradation of CPs have been studied in bacteria and the genes and enzymes involved in the degradation of various CPs have been identified and characterized. This review describes the biochemical and genetic basis of the degradation of CPs and their derivatives. PMID:24589366

  13. Triamine chelants, their derivatives, complexes and conjugates

    DOEpatents

    Troutner, David E. (Phoenixville, PA); John, Christy S. (Gaithersburg, MD); Pillai, Maroor R. A. (Vashi, IN)

    1995-01-01

    A group of functionalized triamine chelants and their derivatives that form complexes with radioactive metal ions are disclosed. The complexes can be covalently attached to a protein or an antibody or antibody fragment and used for therapeutic and/or diagnostic purposes. The chelants are of the formula: ##STR1## wherein n, m, R, R.sup.1, R.sup.2 and L are defined in the specification.

  14. The Science of Deriving Stability Analyses

    Microsoft Academic Search

    P. Bientinesi; R. van de Geijn

    2008-01-01

    We introduce a methodology for obtaining inventories of error results for families of numerical dense linear algebra algorithms. The approach for deriving the analyses is goal-oriented, systematic, and layered. The presentation places the analysis side-by-side with the algorithm so that it is obvious where error is introduced, making it attractive for use in the classroom. Yet the approach is suciently

  15. DNA-polymerase inhibitors. Rifamycin derivatives.

    PubMed Central

    Frolova, L Y; Meldrays, Y A; Kochkina, L L; Giller, S A; Eremeyev, A V; Grayevskaya, N A; Kisselev, L L

    1977-01-01

    Ten new derivatives of the antibiotic rifamycin with variable side chains at position 3 were synthesized. The inhibitory activity of these derivatives against DNA-polymerases isolated from avian myeloblastosis virus, E. coli and calf thymus were studied at various conditions. 3-(2,4,6-trinitrophenylhydrazone-(methyl) rifamycin SV is a strong inhibitor for all the polymerases tested and belongs to the C class inhibitors of reverse transcriptase. 3-(monoallylhydrazone-(methyl) rifamycin SV possesses a selective action on polymerases: at 0.1 mg/ml concentration it almost completely inhibits the reverse transcriptase and less than half of the bacterial and eukaryotic enzymes. A drug is found which strongly inhibits the DNA-polymerases from E. coli and calf thymus and weakly the viral enzyme. The inhibitory effect on reverse transcriptase is independent of the choice of template-primer; it could be overcome by the addition of excess enzyme but not of excess template-primer; the inhibition could be completely reversed by dilution of the drug-enzyme mixture. From Lineweaver-Burk analysis, the inhibition is noncompetitive with respect to the template-primer and, thus the drugs bind to the site different from the active site for the template-primer. From protective action of the template-primer and other data it might be suggested that the rifamycin derivatives act at an early step(s) in DNA synthesis catalyzed by reverse transcriptase. The obtained data are in agreement with the results for other derivatives of rifamycin SV described in literature. PMID:68462

  16. Chemically Derived, Ultrasmooth Graphene Nanoribbon Semiconductors

    Microsoft Academic Search

    Xiaolin Li; Xinran Wang; Li Zhang; Sangwon Lee; Hongjie Dai

    2008-01-01

    We developed a chemical route to produce graphene nanoribbons (GNR) with width below 10 nanometers, as well as single ribbons with varying widths along their lengths or containing lattice-defined graphene junctions for potential molecular electronics. The GNRs were solution-phase derived, stably suspended in solvents with noncovalent polymer functionalization, and exhibited ultrasmooth edges with possibly well-defined zigzag or armchair-edge structures. Electrical

  17. Derivative processes for modelling metabolic fluxes

    PubMed Central

    Žurauskien?, Justina; Kirk, Paul; Thorne, Thomas; Pinney, John; Stumpf, Michael

    2014-01-01

    Motivation: One of the challenging questions in modelling biological systems is to characterize the functional forms of the processes that control and orchestrate molecular and cellular phenotypes. Recently proposed methods for the analysis of metabolic pathways, for example, dynamic flux estimation, can only provide estimates of the underlying fluxes at discrete time points but fail to capture the complete temporal behaviour. To describe the dynamic variation of the fluxes, we additionally require the assumption of specific functional forms that can capture the temporal behaviour. However, it also remains unclear how to address the noise which might be present in experimentally measured metabolite concentrations. Results: Here we propose a novel approach to modelling metabolic fluxes: derivative processes that are based on multiple-output Gaussian processes (MGPs), which are a flexible non-parametric Bayesian modelling technique. The main advantages that follow from MGPs approach include the natural non-parametric representation of the fluxes and ability to impute the missing data in between the measurements. Our derivative process approach allows us to model changes in metabolite derivative concentrations and to characterize the temporal behaviour of metabolic fluxes from time course data. Because the derivative of a Gaussian process is itself a Gaussian process, we can readily link metabolite concentrations to metabolic fluxes and vice versa. Here we discuss how this can be implemented in an MGP framework and illustrate its application to simple models, including nitrogen metabolism in Escherichia coli. Availability and implementation: R code is available from the authors upon request. Contact: j.norkunaite@imperial.ac.uk; m.stumpf@imperial.ac.uk Supplementary information: Supplementary data are available at Bioinformatics online. PMID:24578401

  18. Triamine chelants, their derivatives, complexes and conjugates

    DOEpatents

    Troutner, D.E.; John, C.S.; Pillai, M.R.A.

    1995-03-07

    A group of functionalized triamine chelants and their derivatives that form complexes with radioactive metal ions are disclosed. The complexes can be covalently attached to a protein or an antibody or antibody fragment and used for therapeutic and/or diagnostic purposes. The chelants are of the formula, as shown in the accompanying diagrams, wherein n, m, R, R{sup 1}, R{sup 2} and L are defined in the specification.

  19. ELECTRONIC PROPERTIES OF TIO 2 DERIVED NANOBELTS

    Microsoft Academic Search

    D. Cadavid; R. F. Egerton; M. Malac; M. S. Moreno

    2009-01-01

    TiO2-based nanostructures are considered good candidates for a number of applications in numerous fields as environmental decontamination, photocatalysis, electrocatalytic storage, solar cells, antibacterial agent, etc (1-3). These applications are based on their electronic properties and high surface area which need to be characterized. Titania derived nanobelts are sensitive to electron beam irradiation requiring to assess the conditions under which the

  20. Fixed points of higher-derivative gravity.

    PubMed

    Codello, Alessandro; Percacci, Roberto

    2006-12-01

    We recalculate the beta functions of higher-derivative gravity in four dimensions using the one-loop approximation to an exact renormalization group equation. We reproduce the beta functions of the dimensionless couplings that were known in the literature, but we find new terms for the beta functions of Newton's constant and of the cosmological constant. As a result, the theory appears to be asymptotically safe at a non-Gaussian fixed point rather than perturbatively renormalizable and asymptotically free. PMID:17155791

  1. Fixed Points of Higher-Derivative Gravity

    SciTech Connect

    Codello, Alessandro; Percacci, Roberto [Dipartimento di Fisica Teorica, Universita di Trieste, Viale Miramare, I-34014 Trieste (Italy); SISSA, via Beirut 4, I-34014 Trieste, Italy, and INFN, Sezione di Trieste (Italy)

    2006-12-01

    We recalculate the beta functions of higher-derivative gravity in four dimensions using the one-loop approximation to an exact renormalization group equation. We reproduce the beta functions of the dimensionless couplings that were known in the literature, but we find new terms for the beta functions of Newton's constant and of the cosmological constant. As a result, the theory appears to be asymptotically safe at a non-Gaussian fixed point rather than perturbatively renormalizable and asymptotically free.

  2. Myeloid derived suppressor cells in human diseases

    Microsoft Academic Search

    Tim F. Greten; Michael P. Manns; Firouzeh Korangy

    2011-01-01

    Myeloid derived suppressor cells (MDSC) have been described as a heterogeneous cell population with potent immune suppressor function in mice. Limited data are available on MDSC in human diseases. Interpretation of these data is complicated by the fact that different markers have been used to analyze human MDSC subtypes in various clinical settings. Human MDSC are CD11b+, CD33+, HLA-DRneg\\/low and

  3. Canonical structure of higher derivative theories

    NASA Astrophysics Data System (ADS)

    Avraham, Eran; Brustein, Ram

    2014-07-01

    The canonical structure of theories whose Lagrangian contains higher powers of time derivatives is often obscured by the nonlinear relationship between the velocities and momenta. We use the Dirac formalism and define a generalized Legendre transform to overcome some of the difficulties associated with inverting the relation between velocities and momenta. We are then able to define a standard single valued symplectic structure on phase space and a compatible single valued Hamiltonian. We demonstrate the application of our formalism in several examples.

  4. Antifungal activities of some indole derivatives.

    PubMed

    Xu, Hui; Wang, Qin; Yang, Wen-Bin

    2010-01-01

    Nine indole derivatives were evaluated in vitro against Fusarium graminearum, Alternaria alternata, Helminthosporium sorokinianum, Pyricularia oryzae, Fusarium oxysporum f. sp. vasinfectum, Fusarium oxysporum f. sp. cucumarinum, and Alternaria brassicae. Most of the compounds were found to possess antifungal activities. Especially compounds 2, 5, 8, and 9 exhibited broad-spectrum antifungal activities against the above-mentioned seven phytopathogenic fungi, and showed more potent activities than hymexazole, a commercial agricultural fungicide. PMID:20737910

  5. Pregnene derivatives from Solenostemma argel leaves.

    PubMed

    Hassan, H A; Hame, A I; El-Emary, N A; Springue, I V; Mitome, H; Miyaoka, H

    2001-06-01

    Two new pregnene derivatives 14beta-15alpha-dihydroxy-delta4pregnene-3,20 dione and 3beta-14beta,15alpha-16alpha hydroxy-20-oxo-delta5pregnene-tetra-ol, in addition to alpha- and beta-amyrin and beta-sitosterol, were isolated from Solenostemma argel leaves. The structures were established by extensive spectral analysis as well as comparison with reference materials. PMID:11394848

  6. QSAR studies of antibacterial ricinoleic acid derivatives

    Microsoft Academic Search

    B. Narasimhan; V. K. Mourya; A. S. Dhake

    2007-01-01

    A series of ricinoleic acid derivatives has been synthesized and tested for antibacterial activity with respect to four standard\\u000a strains. Dibromoricinoleic acid (DBRA) showed high activity comparable with that of the reference drug ciprofloxacin. QSARs\\u000a between various physicochemical indices and the antibacterial activity of a training set including 12 compounds were analyzed.\\u000a The topological parameter, the valence second-order molecular connectivity

  7. Fluoride removal performance of glass derived hydroxyapatite

    Microsoft Academic Search

    Wen Liang; Lei Zhan; Longhua Piao; Christian R?ssel

    2011-01-01

    A novel sodium calcium borate glass derived hydroxyapatite (G-HAP) with different ranges of particle size was prepared by immersion sodium calcium borate glass in 0.1M K2HPO4 solution by the ratio of 50gL?1 for 7 days. The unique advantage of G-HAP for the adsorption of fluoride ions in solutions was studied. The effects of size and quantity of particles, pH value

  8. Derivation of the null energy condition

    NASA Astrophysics Data System (ADS)

    Parikh, Maulik; van der Schaar, Jan Pieter

    2015-04-01

    We derive the null energy condition, understood as a constraint on the Einstein-frame Ricci tensor, from world sheet string theory. For a closed bosonic string propagating in a curved geometry, the spacetime interpretation of the Virasoro constraint condition is precisely the null energy condition, to leading nontrivial order in the ?' expansion. Thus the deepest origin of the null energy condition lies in world sheet diffeomorphism invariance.

  9. Vanadium and tungsten derivatives as antidiabetic agents

    Microsoft Academic Search

    José L. Domingo

    2002-01-01

    Tungstate is an oxyanion that has biological similarities to vanadate. In recent years, a number of studies have shown the\\u000a antidiabetic effects of oral tungstate in animal models of diabetes. However, because of the tissue accumulation and potential\\u000a toxicity derived from chronic administration of vanadium and tungsten compounds, the pharmacological use of vanadate or tungstate\\u000a in the treatment of diabetes

  10. The derived generalization of thought suppression

    Microsoft Academic Search

    Nic Hooper; Jo Saunders; Louise McHugh

    2010-01-01

    Thought suppression appears to be a relatively ineffective and even counterproductive strategy for dealing with unwanted thoughts.\\u000a However, the psychological processes responsible for unsuccessful suppression are still underspecified. One process that may\\u000a be implicated is derived stimulus relations, which may underlie the formation of unintentional relations that act to hamper\\u000a suppression attempts. To test this prediction, participants were trained and

  11. Addition of Sulfinic Acids to Methacrylic Derivatives

    Microsoft Academic Search

    S. Ivanova; D. Aleksiev

    2010-01-01

    The kinetics of the addition of arenesulfinic acids to methacrylic derivatives were studied. The reactions were found to be second order over a range of concentrations from 0.01 to 0.10 M. For pH values ranging from 4 to 8, the following rate constants were obtained pH the methylacrylate, chloromethylacrylate, and bromomethylacrylate with benzenesulfinic acids (278 K) were investigated: 2.37 (±

  12. Experimental Comparisons of Derivative Free Optimization Algorithms

    E-print Network

    Auger, Anne; Zerpa, Jorge M Perez; Ros, Raymond; Schoenauer, Marc

    2010-01-01

    In this paper, the performances of the quasi-Newton BFGS algorithm, the NEWUOA derivative free optimizer, the Covariance Matrix Adaptation Evolution Strategy (CMA-ES), the Differential Evolution (DE) algorithm and Particle Swarm Optimizers (PSO) are compared experimentally on benchmark functions reflecting important challenges encountered in real-world optimization problems. Dependence of the performances in the conditioning of the problem and rotational invariance of the algorithms are in particular investigated.

  13. Neutrophil-Derived Cytokines: Facts Beyond Expression

    PubMed Central

    Tecchio, Cristina; Micheletti, Alessandra; Cassatella, Marco A.

    2014-01-01

    Polymorphonuclear neutrophils, besides their involvement in primary defense against infections – mainly through phagocytosis, generation of toxic molecules, release of enzymes, and formation of extracellular traps – are also becoming increasingly important for their contribution to the fine regulation in development of inflammatory and immune responses. These latter functions of neutrophils occur, in part, via their de novo production and release of a large variety of cytokines, including chemotactic cytokines (chemokines). Accordingly, the improvement in technologies for molecular and functional cell analysis, along with concomitant advances in cell purification techniques, have allowed the identification of a continuously growing list of neutrophil-derived cytokines, as well as the characterization of their biological implications in vitro and/or in vivo. This short review summarizes crucial concepts regarding the modalities of expression, release, and regulation of neutrophil-derived cytokines. It also highlights examples illustrating the potential implications of neutrophil-derived cytokines according to recent observations made in humans and/or in experimental animal models. PMID:25374568

  14. Perturbative unitarity of Higgs derivative interactions

    E-print Network

    Yohei Kikuta; Yasuhiro Yamamoto

    2014-10-12

    We study the perturbative unitarity bound given by dimension six derivative interactions consisting of Higgs doublets. These operators emerge from kinetic terms of composite Higgs models or integrating out heavy particles that interact with Higgs doublets. They lead to new phenomena beyond the Standard Model. One of characteristic contributions by derivative interactions appear in vector boson scattering processes. Longitudinal modes of massive vector bosons can be regarded as Nambu Goldstone bosons eaten by each vector field with the equivalence theorem. Since their effects become larger and larger as the collision energy of vector bosons increases, vector boson scattering processes become important in a high energy region around the TeV scale. On the other hand, in such a high energy region, we have to take the unitarity of amplitudes into account. We have obtained the unitarity condition in terms of the parameter included in the effective Lagrangian for one Higgs doublet models. Applying it to some of models, we have found that contributions of derivative interactions are not so large enough to clearly discriminate them from the Standard Model ones. We also study it in two Higgs doublet models. Because they are too complex to obtain the bound in the general effective Lagrangian, we have calculated it in explicit models. These analyses tell us highly model dependence of the perturbative unitarity bounds.

  15. Derivation of naïve human embryonic stem cells

    PubMed Central

    Ware, Carol B.; Nelson, Angelique M.; Mecham, Brigham; Hesson, Jennifer; Zhou, Wenyu; Jonlin, Erica C.; Jimenez-Caliani, Antonio J.; Deng, Xinxian; Cavanaugh, Christopher; Cook, Savannah; Tesar, Paul J.; Okada, Jeffrey; Margaretha, Lilyana; Sperber, Henrik; Choi, Michael; Blau, C. Anthony; Treuting, Piper M.; Hawkins, R. David; Cirulli, Vincenzo; Ruohola-Baker, Hannele

    2014-01-01

    The naïve pluripotent state has been shown in mice to lead to broad and more robust developmental potential relative to primed mouse epiblast cells. The human naïve ES cell state has eluded derivation without the use of transgenes, and forced expression of OCT4, KLF4, and KLF2 allows maintenance of human cells in a naïve state [Hanna J, et al. (2010) Proc Natl Acad Sci USA 107(20):9222–9227]. We describe two routes to generate nontransgenic naïve human ES cells (hESCs). The first is by reverse toggling of preexisting primed hESC lines by preculture in the histone deacetylase inhibitors butyrate and suberoylanilide hydroxamic acid, followed by culture in MEK/ERK and GSK3 inhibitors (2i) with FGF2. The second route is by direct derivation from a human embryo in 2i with FGF2. We show that human naïve cells meet mouse criteria for the naïve state by growth characteristics, antibody labeling profile, gene expression, X-inactivation profile, mitochondrial morphology, microRNA profile and development in the context of teratomas. hESCs can exist in a naïve state without the need for transgenes. Direct derivation is an elusive, but attainable, process, leading to cells at the earliest stage of in vitro pluripotency described for humans. Reverse toggling of primed cells to naïve is efficient and reproducible. PMID:24623855

  16. Joint moments of derivatives of characteristic polynomials

    E-print Network

    Paul-Olivier Dehaye

    2007-09-17

    We investigate the joint moments of the 2k-th power of the characteristic polynomial of random unitary matrices with the 2h-th power of the derivative of this same polynomial. We prove that for a fixed h, the moments are given by rational functions of k, up to a well-known factor that already arises when h=0. We fully describe the denominator in those rational functions (this had already been done by Hughes experimentally), and define the numerators through various formulas, mostly sums over partitions. We also use this to formulate conjectures on joint moments of the zeta function and its derivatives, or even the same questions for the Hardy function, if we use a ``real'' version of characteristic polynomials. Our methods should easily be applicable to other similar problems, for instance with higher derivatives of characteristic polynomials. NOTE: More data is available on the author's website or attached to the LaTeX source of this arXiv submission.

  17. Hydrodynamic Nambu brackets derived by geometric constraints

    NASA Astrophysics Data System (ADS)

    Blender, Richard; Badin, Gualtiero

    2015-03-01

    A geometric approach to derive the Nambu brackets for ideal two-dimensional (2D) hydrodynamics is suggested. The derivation is based on two-forms with vanishing integrals in a periodic domain, and with resulting dynamics constrained by an orthogonality condition. As a result, 2D hydrodynamics with vorticity as dynamic variable emerges as a generic model, with conservation laws which can be interpreted as enstrophy and energy functionals. Generalized forms like surface quasi-geostrophy and fractional Poisson equations for the stream-function are also included as results from the derivation. The formalism is extended to a hydrodynamic system coupled to a second degree of freedom, with the Rayleigh–Bénard convection as an example. This system is reformulated in terms of constitutive conservation laws with two additive brackets which represent individual processes: a first representing inviscid 2D hydrodynamics, and a second representing the coupling between hydrodynamics and thermodynamics. The results can be used for the formulation of conservative numerical algorithms that can be employed, for example, for the study of fronts and singularities.

  18. Transformation of spatial and perturbation derivatives of travel time

    E-print Network

    Cerveny, Vlastislav

    Transformation of spatial and perturbation derivatives of travel time at a general interface We consider the partial derivatives of travel time with respect to both spatial coordinates and perturbation parameters. We derive the explicit equations for transforming these travel­time derivatives

  19. Stem cell-derived neurons functionally integrate in

    E-print Network

    Fortuna, Miguel A.

    Stem cell-derived neurons functionally integrate in living mice Neurons derived from stem cells that, after transplantation into living animals, human stem cell-derived neurons can receive neuronal human embryonic stem cell (hESC)-derived neurons engineered to be specifically activated by light

  20. Superstability of multipliers and ring derivations on Banach algebras

    Microsoft Academic Search

    Takeshi Miura; Hirokazu Oka; Go Hirasawa; Sin-Ei Takahasi

    2007-01-01

    In this paper, we will consider Hyers-Ulam-Rassias stability of\\u000amultipliers and ring derivations between Banach algebras. As a corollary, we will prove superstability of ring derivations and\\u000amultipliers. That is, approximate multipliers and approximate ring derivations are exact multipliers and ring derivations.

  1. Homing missile autopilot response sensitivity to stability derivative variations

    Microsoft Academic Search

    F. William Nesline; Mark L. Nesline

    1984-01-01

    In a recent study, the robustness of a tail controlled homing missile constant gain autopilot to changes in the aerodynamic stability derivative M¿ was examined. The constant gains were determined from nominal values of the aerodynamic control derivative, M¿, and the stability derivative. The stability derivative was then varied in the positive direction until damping degraded to unacceptable levels and

  2. Hydroxylated Sclerosporin Derivatives from the Marine-derived Fungus Cadophora malorum†

    PubMed Central

    Almeida, Celso; Eguereva, Ekaterina; Kehraus, Stefan; Siering, Carsten; König, Gabriele M.

    2010-01-01

    The marine-derived fungus Cadophora malorum was isolated from the green alga Enteromorpha sp. Growth on a biomalt medium supplemented with sea salt yielded an extract from which we have isolated sclerosporin and four new hydroxylated sclerosporin derivatives, namely 15-hydroxysclerosporin (2), 12-hydroxysclerosporin (3), 11-hydroxysclerosporin (4) and 8-hydroxysclerosporin (5). The compounds were evaluated in various biological activity assays. Compound 5 showed a weak fat-accumulation inhibitory activity against 3T3-L1 murine adipocytes. PMID:20052971

  3. Crystallographic investigations of biotin and carboxybiotin derivatives.

    PubMed

    Stallings, W; Detitta, G T

    1985-01-01

    The structures of a family of biotin and carboxybiotin derivatives have provided information on the mechanism of biotin action. The ureido moiety of the uncarboxylated cofactor is polarized and able to interact with ions and polar molecules; intermolecular interactions in the biotin derivatives suggest biochemical mechanisms resulting in nucleophilic activation to the enol tautomer. N1' carboxylation of biotin is important not only as a chemical reaction to generate the carboxyl-transferring species, carboxybiotin, but also in acting as a switch to depolarize the ureido carbonyl oxygen, and thereby facilitating interactions with non-polar molecules. The structure of an N1' methoxycarbonyl biotin derivative reveals such an interaction between the carbonyl oxygen, O2', and a neighboring methyl group. A computer-generated space-filing model of the van der Waals contacts involved in this interaction reveals that the methyl group is locked with respect to rotation and thus suggests a structural basis for the stereospecificity observed in the carboxyl-transferring half-reaction. The flexibility of the valeryl side chains in this family of structures provides translocation models in line with magnetic resonance data which indicate that the translocation events involve motions of, at most, 7 A. Our models demonstrate that such motions may be accomplished by simple, observed conformational changes in bonds of the valeryl side chain which locally adjoin the bicyclic ring system. High resolution, low temperature diffraction data will allow visualization of the bonding and lone pair electrons in biotin. These studies will serve to extend and fine-tune our description of the electronic structure of biotin which is currently based on accurate measurements of bond distances and angles. PMID:3860171

  4. Derivation of Canine Induced Pluripotent Stem Cells.

    PubMed

    Baird, Aeg; Barsby, T; Guest, D J

    2015-08-01

    Dogs and humans have many inherited genetic diseases in common and conditions that are increasingly prevalent in humans also occur naturally in dogs. The use of dogs for the experimental and clinical testing of stem cell and regenerative medicine products would benefit canine health and welfare and provide relevant animal models for the translation of therapies to the human field. Induced pluripotent stem cells (iPSCs) have the capacity to turn into all cells of the body and therefore have the potential to provide cells for therapeutic use and for disease modelling. The objective of this study was to derive and characterize iPSCs from karyotypically abnormal adult canine cells. Aneuploid adipose-derived mesenchymal stromal cells (AdMSCs) from an adult female Weimeraner were re-programmed into iPSCs via overexpression of four human pluripotency factors (Oct 4, Sox2, Klf4 and c-myc) using retroviral vectors. The iPSCs showed similarity to human ESCs with regard to morphology, pluripotency marker expression and the ability to differentiate into derivatives of all three germ layers in vitro (endoderm, ectoderm and mesoderm). The iPSCs also demonstrated silencing of the viral transgenes and re-activation of the silent X chromosome, suggesting full reprogramming had occurred. The levels of aneuploidy observed in the AdMSCs were maintained in the iPSCs. This finding demonstrates the potential for generating canine induced pluripotent stem cells for use as disease models in addition to regenerative medicine and pharmaceutical testing. PMID:26074059

  5. Higher Derivative versus Second Order Field Equations

    NASA Astrophysics Data System (ADS)

    Müller-Hoissen, F.

    The first part of this work reviews problems of (particle and field) theories with higher than second time derivatives. The second part gives an overview about the known results concerning the structure of bosonic field theories with at most second order equations.Translated AbstractFeldgleichungen höherer versus zweiter OrdnungDie erste Hälfte dieser Arbeit faßt die bekannten Probleme von (Teilchenund Feld-)Gleichungen mit höheren als zweiten Zeitableitungen zusammen. In der zweiten Hälfte wird eine Übersicht über die Struktur der komplementären Klasse von Feldgleichungen mit höchstens zweiten Zeitableitungen für bosonische Felder gegeben.

  6. Black holes in higher derivative gravity.

    PubMed

    Lü, H; Perkins, A; Pope, C N; Stelle, K S

    2015-05-01

    Extensions of Einstein gravity with higher-order derivative terms arise in string theory and other effective theories, as well as being of interest in their own right. In this Letter we study static black-hole solutions in the example of Einstein gravity with additional quadratic curvature terms. A Lichnerowicz-type theorem simplifies the analysis by establishing that they must have vanishing Ricci scalar curvature. By numerical methods we then demonstrate the existence of further black-hole solutions over and above the Schwarzschild solution. We discuss some of their thermodynamic properties, and show that they obey the first law of thermodynamics. PMID:25978224

  7. Dietary derived compounds in cancer chemoprevention

    PubMed Central

    Rzeski, Wojciech

    2012-01-01

    Cancer chemoprevention is defined as the application of natural or synthetic agents to suppress or reverse cancer development and progression. In this field especially diet derived compounds have recently attracted researchers’ attention as potential therapeutics generally exerting low toxicity compared with regular drugs. This review presents a survey of recent findings concerning the most promising dietary chemopreventive agents such as green tea polyphenols (i.e. catechins), long-chain polyunsaturated fatty acids, carotenoids, glucosinolates/isothiocyanates, vitamins (i.e. vitamin D and folate) and minerals (i.e. calcium and selenium). Molecular targets involved in intrinsic pathways affected by these natural compounds are also shortly discussed. PMID:23788916

  8. Diphenylurea Derivatives Induce Somatic Embryogenesis in Citrus

    Microsoft Academic Search

    Angela Carra; Fabio De Pasquale; Ada Ricci; Francesco Carimi

    2006-01-01

    The present research investigates the possibility that three diphenylurea (DPU) derivatives, N-phenyl-N?-benzothiazol-6-ylurea (PBU), N,N?-bis-(2,3-methilendioxyphenyl)urea (2,3-MDPU) and N,N?-bis-(3,4-methilendioxyphenyl)urea (3,4-MDPU), stimulate the induction of somatic embryogenesis in three Citrus species. The hypothetical embryogenic activity was assessed using stigma and styles of Citrus myrtifolia Raf., Citrus madurensis Lour. and Citrus limon (L.) Burm. The three compounds influenced the production of somatic embryos differently

  9. Enhanced cubic optical nonlinearity of oligoazine derivatives

    NASA Astrophysics Data System (ADS)

    Singh, Vijender; Aghamkar, Praveen; Malik, Rajesh Kumar

    2014-06-01

    We report a large positive third-order optical nonlinearity of synthesized oligoazine derivatives (OADs) using z-scan technique at 532 nm by Q-switched Nd:YAG laser. Optical band gap of OADs shrinks with increasing repeated units. Origin of large cubic nonlinearity is in the extensive ?-electron delocalization. We obtained the values of and in OADs. Moreover, values of optical nonlinearity of OADs show reasonable agreement with the theoretically predicted values. We have shown OADs could be used as good reverse saturable absorber and self-focusing materials. Optical limiting, due to reverse saturable absorption, has also been successfully demonstrated at 532 nm.

  10. A geometrical derivation of the Dirac equation

    E-print Network

    Y. Jack Ng; H. van Dam

    2003-02-04

    We give a geometrical derivation of the Dirac equation by considering a spin-1/2 particle travelling with the speed of light in a cubic spacetime lattice. The mass of the particle acts to flip the multi-component wavefunction at the lattice sites. Starting with a difference equation for the case of one spatial and one time dimensions, we generalize the approach to higher dimensions. Interactions with external electromagnetic and gravitational fields are also considered. One logical interpretation is that only at the lattice sites is the spin-1/2 particle aware of its mass and the presence of external fields.

  11. Adipose derived stem cells and nerve regeneration

    PubMed Central

    Faroni, Alessandro; Smith, Richard JP; Reid, Adam J

    2014-01-01

    Injuries to peripheral nerves are common and cause life-changing problems for patients alongside high social and health care costs for society. Current clinical treatment of peripheral nerve injuries predominantly relies on sacrificing a section of nerve from elsewhere in the body to provide a graft at the injury site. Much work has been done to develop a bioengineered nerve graft, precluding sacrifice of a functional nerve. Stem cells are prime candidates as accelerators of regeneration in these nerve grafts. This review examines the potential of adipose-derived stem cells to improve nerve repair assisted by bioengineered nerve grafts. PMID:25221589

  12. Kinetic resolutions of indan derivatives using bacteria.

    PubMed

    Tarui, Naoki; Watanabe, Hayao; Fukatsu, Kohji; Ohkawa, Shigenori; Nakahama, Kazuo

    2002-02-01

    Racemic indan derivatives have been resolved by the hydrolysis of amide bonds using Corynebacterium ammoniagenes IFO12612 to produce (S)-amine and (R)-amides. In the kinetic resolution of 1 (N-12-(6-methoxy-indan-1-yl)ethyl]acetamide), it was possible to run the reaction to 44% conversion on a 10-g scale, obtaining (S)-amine 4 ((S)-2-(6-methoxy-indan-1-yl)ethylamine) at >99% enantiomeric excess (ee) and (R)-1 at 98% ee. PMID:11999429

  13. New naphthoquinone derivatives against glioma cells.

    PubMed

    Redaelli, Marco; Mucignat-Caretta, Carla; Isse, Abdirisak Ahmed; Gennaro, Armando; Pezzani, Raffaele; Pasquale, Riccardo; Pavan, Valeria; Crisma, Marco; Ribaudo, Giovanni; Zagotto, Giuseppe

    2015-05-26

    This work was aimed to the development of a set of new naphtoquinone derivatives that can act against glioma. The compounds were tested in order to find out their ability to inhibit the growth of glioma cells, and the results of these assays were correlated with electrochemical analysis and NMR-based reoxidation kinetic studies, suggesting that a redox mechanism underlies and may explain the observed biological behavior. In addition to a full description of the synthetic pathways, electrochemistry, NMR and single crystal X-ray diffraction data are provided. PMID:25916907

  14. Deriving the Ages of Field White Dwarfs

    NASA Astrophysics Data System (ADS)

    von Hippel, Ted; van Dyk, David; Si, Shijing; Montgomery, Michael; O'Malley, Erin; Robinson, Elliot; Stenning, David; Stein, Nathan; Kraczek, Elizabeth Jeffery; Jefferys, William H.; Webster, Aaron

    2015-06-01

    We apply a self-consistent and robust Bayesian statistical approach along with modern model ingredients to determine the posterior distributions of ages, distances, and ZAMS masses of old field white dwarfs from the Galactic disk, thick disk, and halo. Our technique requires only quality optical and near-IR photometry to derive ages with ? 15% uncertainties. We additionally predict the capabilities of these techniques in the GAIA era, when we will possess distances accurate to 1-2% for thousands of white dwarfs.

  15. Studies on hydrazone derivatives as antifungal agents.

    PubMed

    Ozdemir, Ahmet; Turan-Zitouni, Gulhan; Kaplancikli, Zafer Asim; Demirci, Fatih; Iscan, Gokalp

    2008-08-01

    The increasing clinical importance of drug-resistant fungal pathogens has urged additional need to fungal research and new antifungal compound development. For this purpose, some N-(1-benzyl-2-phenylethylidene)-N'-[4-(aryl)thiazol-2-yl]hydrazone (1a-e) and N-(1-phenylbutylidene)-N'-[4-(aryl)thiazol-2-yl]hydrazone (2a-e) derivatives were synthesised and evaluated for antifungal activity. Their antifungal activities against standard and clinical strands of Candida albicans, Candida glabrata, Candida utilis, Candida tropicalis, Candida krusei, Candida zeylanoides, and Candida parapsilosis were investigated. A significant level of activity was observed. PMID:18665994

  16. Simple derivation of the Lindblad equation

    NASA Astrophysics Data System (ADS)

    Pearle, Philip

    2012-07-01

    The Lindblad equation is an evolution equation for the density matrix in quantum theory. It is the general linear, Markovian, form which ensures that the density matrix is Hermitian, trace 1, positive and completely positive. Some elementary examples of the Lindblad equation are given. The derivation of the Lindblad equation presented here is ‘simple’ in that all it uses is the expression of a Hermitian matrix in terms of its orthonormal eigenvectors and real eigenvalues. Thus, it is appropriate for students who have learned the algebra of quantum theory. Where helpful, arguments are first given in a two-dimensional Hilbert space.

  17. Langevin molecular dynamics derived from Ehrenfest dynamics

    E-print Network

    Anders Szepessy

    2011-03-30

    Stochastic Langevin molecular dynamics for nuclei is derived from the Ehrenfest Hamiltonian system (also called quantum classical molecular dynamics) in a Kac-Zwanzig setting, with the initial data for the electrons stochastically perturbed from the ground state and the ratio, $M$, of nuclei and electron mass tending to infinity. The Ehrenfest nuclei dynamics is approximated by the Langevin dynamics with accuracy $o(M^{-1/2})$ on bounded time intervals and by $o(1)$ on unbounded time intervals, which makes the small $\\mathcal{O}(M^{-1/2})$ friction and $o(M^{-1/2})$ diffusion terms visible. The initial electron probability distribution is a Gibbs density at low temperture, derived by a stability and consistency argument: starting with any equilibrium measure of the Ehrenfest Hamiltonian system, the initial electron distribution is sampled from the equilibrium measure conditioned on the nuclei positions, which after long time leads to the nuclei positions in a Gibbs distribution (i.e. asymptotic stability); by consistency the original equilibrium measure is then a Gibbs measure.The diffusion and friction coefficients in the Langevin equation satisfy the Einstein's fluctuation-dissipation relation.

  18. Model-Derived Multisensor Target Discrimination

    NASA Astrophysics Data System (ADS)

    Vogel, Mark A.; Chan, Tony C.

    1989-01-01

    Prediction of target signatures using complex computer models of targets and sensor characteristics permits the development of robust target discrimination algorithms in the absence of large data collections. This paper describes the methodology of employing model-derived data in multisensor target discrimination activities. The signature predictions not only provide reference data for algorithms but also aid in the design optimization of multisensor collection configurations. Due to their ability to process more information, multisensor target recognition algorithms are expected to outperform single sensor designs. Development of multisensor algorithms is hampered by extensive requirements for registered training and reference data. By relying heavily on predicted signatures for sensor parameter selection and algorithm development, the required quantity of sensed data collection is greatly reduced. The usefulness of the collected data is focused and enhanced by examination of modeling and validation requirements. Final expansion of algo-rithm designs from straightforward pattern recognition approaches to more highly-evolved model-based recognition concepts is more easily bridged when model-derived data plays a significant role at each developmental stage.

  19. Derive capillary pressure from well logs

    SciTech Connect

    Ibrahim, A. (Suez Canal Univ. (Egypt)); Desbrandes, R.; Bassiouni, Z. (Louisiana State Univ., Baton Rouge, LA (United States))

    1994-07-01

    A new approach has been developed to estimate in-situ capillary pressure and relative permeability characteristics in the transition zone. The technique is based on incorporating petrophysical data measured on core samples with well log analysis. Relative permeability can be determined for both drainage and inhibition conditions using the matched capillary pressure data. A technique has been developed to extrapolate petro-physical data where core data is absent or not representative of in-situ conditions. It is based on using log data to derive a water saturation vs. depth profile in the transition zone of the formation of interest. The log-derived water saturation distribution is then correlated to generalized capillary pressure curves typical of the formation studied. The capillary pressure type curves are generated from available core data and other petrophysical information. Relative permeability curves are then generated using correlations based on Purcell's model. The technique can be used in multi-layered and homogeneous reservoirs provided that one homogeneous layer is at least 20 ft thick.

  20. New derivative of carnosine for nanoparticle assemblies.

    PubMed

    Bellia, Francesco; Oliveri, Valentina; Rizzarelli, Enrico; Vecchio, Graziella

    2013-01-01

    Carnosine (?-alanyl-l-histidine) is an endogenous dipeptide, extensively studied owing to its multifunctional activity exhibited in tissues of several animal species. This natural compound may act as a physiological buffer, ion-chelating agent (especially for copper(II) and zinc(II)), antioxidant and antiglycating agent. The main limit for the therapeutical uses of carnosine is the rapid hydrolysis mostly in human plasma by carnosinase. The chemical derivatization of carnosine is a promising strategy to improve the bioavailability of the dipeptide and facilitating the site-specific transport to different tissues. On this basis, a new carnosine derivative with biotin was synthesized and structurally characterized by NMR and MS measurements, with aim of exploiting the avidin-biotin technology that offers a universal system for selective delivery of any biotinylated agent. The stability of the new carnosine derivative towards the hydrolytic action of serum carnosinase as well as the copper(II) binding ability of the carnosine-biotin conjugate were also assessed. The binding affinity of the new molecular entity to avidin and streptavidin, investigated by a spectrophotometric assay, was exploited to functionalize avidin- and streptavidin-gold nanoparticles with the carnosine-biotin conjugate. PMID:24158014

  1. Quinolines derivatives as novel sunscreening agents.

    PubMed

    Polonini, Hudson C; Dias, Rafael M P; Souza, Isabela O; Gonçalves, Karla Mara; Gomes, Tiago B B; Raposo, Nádia R B; da Silva, Adilson David

    2013-08-15

    Currently, the research and development of sunscreens play an important role on the synthesis of actives that are stable in various kinds of formulations-in addition to their efficiency and broad spectrum of protection against ultraviolet radiation. Our objective here was to synthesize new sunscreening chemical agents using quinoline as a base molecule. Twelve quinoline derivatives were synthesized, four of them novel molecules, and their photoprotective activity was determined in vitro using diffuse transmittance spectrophotometry. We determined their SPF, UVAPF, UVA/UVB ratio, critical wavelength and Boots Star Rating. The quinolines derivatives presented a varied profile of photoprotection, their SPF ranging from 2 to 11 and their UVAPF from 2 to 7. In terms of the critical wavelength, all molecules were considered of broad-spectrum by different classifications. Regarding the Boots Star Rating, one compound received no rating, seven of them received a three stars rating, three received a four stars rating and three were given a five stars rating. The molecules showed in the present work have a wide range of possibilities for creating new sunscreen products, once they have good SPF or UVAPF for single molecules, and they also possess other different qualities that can act synergistically. PMID:23856048

  2. Metabolism of hop-derived bitter acids.

    PubMed

    Cattoor, Ko; Dresel, Michael; De Bock, Lies; Boussery, Koen; Van Bocxlaer, Jan; Remon, Jean-Paul; De Keukeleire, Denis; Deforce, Dieter; Hofmann, Thomas; Heyerick, Arne

    2013-08-21

    In this study, in vitro metabolism of hop-derived bitter acids was investigated. Besides their well-known use as bitter compounds in beer, in several studies, bioactive properties have been related to these types of molecules. However, scientific data on the absorption, distribution, metabolism, and excretion aspects of these compounds are limited. More specific, in this study, ?-acids, ?-acids, and iso-?-acids were incubated with rabbit microsomes, and fractions were subjected to LC-MS/MS analysis for identification of oxidative biotransformation products. Metabolism of ?-acids was mainly characterized by conversion into hulupones and the formation of a series of tricyclic oxygenated products. The most important metabolites of ?-acids were identified as humulinones and hulupones. Iso-?-acids were found to be primarly metabolized into cis- and trans-humulinic acids, next to oxidized alloiso-?-acids. Interestingly, the phase I metabolites were highly similar to the oxidative degradation products in beer. These findings show a first insight into the metabolites of hop-derived bitter acids and could have important practical implications in the bioavailability aspects of these compounds, following ingestion of hop-based food products and nutraceuticals. PMID:23898921

  3. Tulczyjew Triples in Higher Derivative Field Theory

    E-print Network

    Katarzyna Grabowska; Luca Vitagliano

    2015-02-20

    The geometrical structure known as Tulczyjew triple has been used with success in analytical mechanics and first order field theory to describe a wide range of physical systems including Lagrangian/Hamiltonian systems with constraints and/or sources, or with singular Lagrangian. Starting from the first principles of the variational calculus we derive Tulczyjew triples for classical field theories of arbitrary high order, i.e. depending on arbitrary high derivatives of the fields. A first triple appears as the result of considering higher order theories as first order ones with configurations being constrained to be holonomic jets. A second triple is obtained after a reduction procedure aimed at getting rid of nonphysical degrees of freedom. This picture we present is fully covariant and complete: it contains both Lagrangian and Hamiltonian formalisms, in particular the Euler-Lagrange equations. Notice that, the required Geometry of jet bundles is affine (as opposed to the linear Geometry of the tangent bundle). Accordingly, the notions of affine duality and affine phase space play a distinguished role in our picture. In particular the Tulczyjew triples in this paper consist of morphisms of double affine-vector bundles which, moreover, preserve suitable presymplectic structures.

  4. Generation of deletion derivatives by targeted transformation of human-derived yeast artificial chromosomes

    SciTech Connect

    Pavan, W.J.; Hieter, P.; Reeves, R.H. (Johns Hopkins Univ. School of Medicine, Baltimore, MD (USA))

    1990-02-01

    Mammalian DNA segments cloned as yeast artificial chromosomes (YACs) can be manipulated by DNA-mediated transformation when placed in an appropriate yeast genetic background. A fragmenting vector has been developed that can introduce a yeast telomere and selectable marker into human-derived YACs at specific sites by means of homologous recombination, deleting all sequences distal to the recombination site. A powerful application of the method uses a human Alu family repeat sequence to target recombination to multiple independent sites on a human-derived YAC. Sets of deletion derivatives generated by this procedure greatly facilitate restriction mapping of large genomic segments. Targeting recombination with single copy sequences, such as cDNAs, will have many additional applications. This approach establishes a paradigm for manipulation and characterization of mammalian DNA segments cloned as YACs.

  5. A new glutarimide derivative from marine sponge-derived Streptomyces anulatus S71.

    PubMed

    Sun, Dandan; Sun, Wei; Yu, Yinxian; Li, Zhiyong; Deng, Zixin; Lin, Shuangjun

    2014-01-01

    Four glutarimide-derived compounds including a new 3-[2-[2-hydroxy-3-methylphenyl-5-(hydroxymethyl)]-2-oxoethyl] glutarimide (1) and three known 3-[2-(2-hyroxy-3,5- dimethylphenyl)-2-oxoethyl] glutarimide (2, actiphenol), 3-hydroxy-3-[2-(2-hydroxy-3,5-dimethylphenyl)-2-oxoethyl] glutarimide (3) and 3-[2-[2-hydroxy-3-(hydroxymethyl)-5-methylphenyl]-2-oxoethyl] glutarimide (4), along with a known indole alkaloid 3-(hydroxyacetyl) indole (5), were isolated from ethyl acetate extract of the fermentation broth of the marine sponge-derived Streptomyces anulatus S71. Their structures were deduced by extensive studies of NMR and mass spectra. PMID:24949797

  6. Cytotoxic Anthranilic Acid Derivatives from Deep Sea Sediment-Derived Fungus Penicillium paneum SD-44

    PubMed Central

    Li, Chun-Shun; Li, Xiao-Ming; Gao, Shu-Shan; Lu, Yan-Hua; Wang, Bin-Gui

    2013-01-01

    Five new anthranilic acid derivatives, penipacids A–E (1–5), together with one known analogue (6), which was previously synthesized, were characterized from the ethyl acetate extract of the marine sediment-derived fungus Penicillium paneum SD-44. Their structures were elucidated mainly by extensive NMR spectroscopic and mass spectrometric analysis. The cytotoxicity and antimicrobial activity of the isolated compounds were evaluated. Compounds 1, and 5 exhibited inhibitory activity against human colon cancer RKO cell line, while compound 6 displayed cytotoxic activity against Hela cell line. PMID:23966037

  7. Genetic instability in calamondin ( Citrus madurensis Lour.) plants derived from somatic embryogenesis induced by diphenylurea derivatives

    Microsoft Academic Search

    Mirko Siragusa; Angela Carra; Lidia Salvia; Anna Maria Puglia; Fabio De Pasquale; Francesco Carimi

    2007-01-01

    Somatic embryos were regenerated in vitro from calamondin style–stigma explants cultured in the presence of N\\u000a 6-benzylaminopurine (BAP) cytokinin and three synthetic phenylurea derivatives, N-(2-chloro-4-pyridyl)-N-phenylurea (4-CPPU), N-phenyl-N?-benzothiazol-6-ylurea (PBU) and N,N?-bis-(2,3-methilendioxyphenyl)urea (2,3-MDPU). The phenylurea derivative compounds tested at micromolar level (12 ?M) were\\u000a able to induce a percentage of responsive explants significantly higher from that obtained with BAP and hormone-free (HF)\\u000a conditions.

  8. Overview of medically important antifungal azole derivatives.

    PubMed Central

    Fromtling, R A

    1988-01-01

    Fungal infections are a major burden to the health and welfare of modern humans. They range from simply cosmetic, non-life-threatening skin infections to severe, systemic infections that may lead to significant debilitation or death. The selection of chemotherapeutic agents useful for the treatment of fungal infections is small. In this overview, a major chemical group with antifungal activity, the azole derivatives, is examined. Included are historical and state of the art information on the in vitro activity, experimental in vivo activity, mode of action, pharmacokinetics, clinical studies, and uses and adverse reactions of imidazoles currently marketed (clotrimazole, miconazole, econazole, ketoconazole, bifonazole, butoconazole, croconazole, fenticonazole, isoconazole, oxiconazole, sulconazole, and tioconazole) and under development (aliconazole and omoconazole), as well as triazoles currently marketed (terconazole) and under development (fluconazole, itraconazole, vibunazole, alteconazole, and ICI 195,739). PMID:3069196

  9. ?-glucuronidase inhibitory studies on coumarin derivatives.

    PubMed

    Khan, Khalid Mohammed; Fakhri, Muhammad Imran; Shaikh, Nimra Naveed; Saad, Syed Muhammad; Hussain, Shafqat; Perveen, Shahnaz; Choudhary, Muhammad Iqbal

    2014-01-01

    Twenty-three (23) derivatives of coumarin (5-27) were synthesized and screened for their in vitro ?- glucuronidase (E. coli) inhibitory activities. Only three compounds, 7,8-dihydroxy-4-methyl-2H-chromen-2-one (9) (IC50 = 52.39 ± 1.85 µM), 3-chloro-6-hexyl-7-hydroxy-4-methyl-2H-chromen-2-one (18) (IC50 = 60.50 ± 0.87 µM), and 3,6- dichloro-7-hydroxy-4-methyl-2H-chromen-2-one (15) (IC50 = 380.26 ± 0.92 µM) displayed activities against ?- glucuronidase as compared to standard D-saccharic acid 1,4-lactone (IC50 = 45.75 ± 2.16 µM). The results indicated that the activity of the synthetic coumarins depends upon the substituents present on the coumarin skeleton. PMID:24611780

  10. Chaotic inflation in higher derivative gravity theories

    E-print Network

    Shynaray Myrzakul; Ratbay Myrzakulov; Lorenzo Sebastiani

    2015-02-25

    In this paper, we investigate chaotic inflation from scalar field subjected to potential in the framework of $f(R^2, P, Q)$-gravity, where we add a correction to Einstein's gravity based on a function of the square of the Ricci scalar $R^2$, the contraction of the Ricci tensor $P$, and the contraction of the Riemann tensor $Q$. The Gauss-Bonnet case is also discussed. We give the general formalism of inflation, deriving the slow-roll parameters, the $e$-folds number, and the spectral indexes. Several explicit examples are furnished, namely we will consider the cases of massive scalar field and scalar field with quartic potential and some power-law function of the curvature invariants under investigation in the gravitational action of the theory. Viable inflation according with observations is analyzed.

  11. Chlorine NQR on Derivatives of Chloral

    NASA Astrophysics Data System (ADS)

    Hashimoto, Masao; Weiden, Norbert; Weiss, Alarich

    1980-10-01

    The 35Cl-NQR spectrum of several derivatives of chloral, Cl3CCHO, was studied in the ranee 77 K ? T ? Tm. By use of the spin echo double resonance technique a relative assignment of the resonances to different Cl3C-groups within one crystallized compound was possible. The solid compounds studied are: High temperature phase of chloral hydrate, Cl3CCH(OH)2; parachloral, (Cl3CCHO)3, (?-and ß-isomer); the two phases of chloral hemihydrate Cl3CCHO · 1/2 H2O; chloralide (II); chloralhemithiohydrate, Cl3CCHO · 1/2 H2S. The structure of the molecules in the solid state and the fade out of the NQR resonances are discussed.

  12. Cationically polymerizable monomers derived from renewable sources

    SciTech Connect

    Crivello, J.V.

    1991-10-01

    The objective of this project is to make use of products obtained from renewable plant sources as monomers for the direct production of polymers which can be used for a wide range of plastic applications. In this report is described progress in the synthesis and polymerization of cationically polymerizable monomers and oligomers derived from botanical oils, terpenes, natural rubber, and lignin. Nine different botanical oils were obtained from various sources, characterized and then epoxidized. Their photopolymerization was carried out using cationic photoinitiators and the mechanical properties of the resulting polymers characterized. Preliminary biodegradation studies are being conducted on the photopolymerized films from several of these oils. Limonene was cationically polymerized to give dimers and the dimers epoxidized to yield highly reactive monomers suitable for coatings, inks and adhesives. The direct phase transfer epoxidation of squalene and natural rubber was carried out. The modified rubbers undergo facile photocrosslinking in the presence of onium salts to give crosslinked elastomers. 12 refs., 3 figs., 10 tabs.

  13. Chaotic inflation in higher derivative gravity theories

    E-print Network

    Myrzakul, Shynaray; Sebastiani, Lorenzo

    2015-01-01

    In this paper, we investigate chaotic inflation from scalar field subjected to potential in the framework of $f(R^2, P, Q)$-gravity, where we add a correction to Einstein's gravity based on a function of the square of the Ricci scalar $R^2$, the contraction of the Ricci tensor $P$, and the contraction of the Riemann tensor $Q$. The Gauss-Bonnet case is also discussed. We give the general formalism of inflation, deriving the slow-roll parameters, the $e$-folds number, and the spectral indexes. Several explicit examples are furnished, namely we will consider the cases of massive scalar field and scalar field with quartic potential and some power-law function of the curvature invariants under investigation in the gravitational action of the theory. Viable inflation according with observations is analyzed.

  14. Platelet-Derived Serotonin Mediates Liver Regeneration

    NASA Astrophysics Data System (ADS)

    Lesurtel, Mickael; Graf, Rolf; Aleil, Boris; Walther, Diego J.; Tian, Yinghua; Jochum, Wolfram; Gachet, Christian; Bader, Michael; Clavien, Pierre-Alain

    2006-04-01

    The liver can regenerate its volume after major tissue loss. In a mouse model of liver regeneration, thrombocytopenia, or impaired platelet activity resulted in the failure to initiate cellular proliferation in the liver. Platelets are major carriers of serotonin in the blood. In thrombocytopenic mice, a serotonin agonist reconstituted liver proliferation. The expression of 5-HT2A and 2B subtype serotonin receptors in the liver increased after hepatectomy. Antagonists of 5-HT2A and 2B receptors inhibited liver regeneration. Liver regeneration was also blunted in mice lacking tryptophan hydroxylase 1, which is the rate-limiting enzyme for the synthesis of peripheral serotonin. This failure of regeneration was rescued by reloading serotonin-free platelets with a serotonin precursor molecule. These results suggest that platelet-derived serotonin is involved in the initiation of liver regeneration.

  15. A Shuttle Derived Vehicle launch system

    NASA Astrophysics Data System (ADS)

    Tewell, J. R.; Buell, D. N.; Ewing, E. S.

    1982-10-01

    This paper describes a Shuttle Derived Vehicle (SDV) launch system presently being studied for the NASA by Martin Marietta Aerospace which capitalizes on existing Shuttle hardware elements to provide increased accommodations for payload weight, payload volume, or both. The SDV configuration utilizes the existing solid rocket boosters, external tank and the Space Shuttle main engines but replaces the manned orbiter with an unmanned, remotely controlled cargo carrier. This cargo carrier substitution more than doubles the performance capability of the orbiter system and is realistically achievable for minimal cost. The advantages of the SDV are presented in terms of performance and economics. Based on these considerations, it is concluded that an unmanned SDV offers a most attractive complement to the present Space Transportation System.

  16. Fluorescein Derivatives in Intravital Fluorescence Imaging

    PubMed Central

    Robertson, Thomas A.; Bunel, Florestan; Roberts, Michael S.

    2013-01-01

    Intravital fluorescence microscopy enables the direct imaging of fluorophores in vivo and advanced techniques such as fluorescence lifetime imaging (FLIM) enable the simultaneous detection of multiple fluorophores. Consequently, it is now possible to record distribution and metabolism of a chemical in vivo and to optimise the delivery of fluorophores in vivo. Recent clinical applications with fluorescein and other intravital fluorescent stains have occurred in neurosurgery, dermatology [including photodynamic therapy (PDT)] and endomicroscopy. Potential uses have been identified in periodontal disease, skin graft and cancer surgery. Animal studies have demonstrated that diseased tissue can be specifically stained with fluorophore conjugates. This review focuses on the fluorescein derived fluorophores in common clinical use and provides examples of novel applications from studies in tissue samples. PMID:24709799

  17. Nanostructured YSZ membranes derived from inorganic salts

    NASA Astrophysics Data System (ADS)

    Zhang, Cunlin; Liao, Yang; He, Shuli; Sun, Defeng; Chen, Wen

    2005-01-01

    The nanostuctured YSZ (Yttria Stabilized Zirconia) membranes on Si(110) substrates are successfully prepared by sol-gel technology derived from inorganic salts ZrOCl2"8H2O, H2C2O4"2H2O and Y(NO3)3"6H2O. By means of controlling the supersaturation and diffusion velocity in solution when the zirconyl oxalate xerogels are repeptized, spherical colloidal paricles with different distributions are obtained. we propose that the peptization of xerogels can be considered as a process of nucleation and growth of colloidal particles. The membranes are preparated by spinning the modified sols on Si(110) substrates. After calcining at 800°C for 1 hour, the membranes are crack-free and mirrorlike. The membranes consist of monodisperse fine spherical crystallines in the range of 20~220nm in diameter, which microstructures are controlled by changing the size and distribution of colloidal particles in sols.

  18. Thiazolidone derivatives as inhibitors of chikungunya virus.

    PubMed

    Jadav, Surender Singh; Sinha, Barij Nayan; Hilgenfeld, Rolf; Pastorino, Boris; de Lamballerie, Xavier; Jayaprakash, Venkatesan

    2015-01-01

    A series of arylalkylidene derivatives of 1,3-thiazolidin-4-one (1-20) were synthesized and tested for their antiviral activity against chikungunya virus (LR2006_OPY1) in Vero cell culture by CPE reduction assay. Five compounds (7-9, 16 and 19) were identified to have anti-ChikV activity at lower micro molar concentration. The compounds 7, 8, 9, 16 and 19 inhibited the virus at 0.42, 4.2, 3.6, 40.1 and 6.8 ?M concentrations respectively. Molecular docking simulation has been carried out using the available X-ray crystal structure of the ChikV nsp2 protease, in order to elucidate the possible mechanism of action. Interaction of ligands with ChikV nsp2 protease (PDB Code: 3TRK) suggested the possible mechanism of protease inhibition to act as potent anti-ChikV agents. PMID:25462237

  19. Flavonoids and phenylpropanoid derivatives from Campanula barbata.

    PubMed

    Cuendet, M; Potterat, O; Hostettmann, K

    2001-03-01

    Four new phenylpropanoid derivatives, barbatosides A-D, and a new catechin, barbatoflavan, were isolated from the whole plant of Campanula barbata L. (Campanulaceae) and identified as wahlenbergioside-3'-O-glucoside, wahlenbergioside-3'-O-(2'''-(p-methoxycinnamoyl))-glucoside, wahlenbergioside-3'-O-(4'''-(trans-p-coumaroyl))-glucoside, wahlenbergioside-3'-O-(4"'-(cis-p-coumaroyl))-glucoside and 3-acetyl-5-methoxy-7,3',4'-trihydroxy-8-O-glucoside-flavan-3-ol, respectively, by spectroscopic methods. In addition, four flavonols were isolated and identified as kaempferol-3-O-glucoside, kaempferol-3-O-rutinoside, quercetin-3-O-glucoside and quercetin-3-O-rutinoside. Barbatoflavan demonstrated scavenging properties towards the DPPH radical. PMID:11281141

  20. Unusual structures of lithium terphenyl derivatives

    Microsoft Academic Search

    Ned J Hardman; Brendan Twamley; Matthias Stender; Richard Baldwin; Shirley Hino; Berthold Schiemenz; Susan M Kauzlarich; Philip P Power

    2002-01-01

    The synthesis, spectroscopic and structural characterization of three new lithium derivatives of terphenyl ligands are reported. These are the mixed lithium alkyl–lithium aryl compound {Li(t-Bu)LiC6H3-2,6-Trip2} (1, Trip=C6H2-2,4,6-i-Pr3), the dilithiated {LiC6H3-2-(C6H3-2-Me-5-t-Bu)-6-(C6H3-2-CH2Li-5-t-Bu)·Et2O}2 (2), and the ether solvated (Et2O)LiC6H3-2,6-(C6H4-4-t-Bu)2 (3). The synthesis of the terphenyl halide precursors for 2 and 3 is also given. The compound 1 resulted from the treatment of 1-IC6H3-2,6-Trip

  1. Synthesis and antitumor activity of tetrandrine derivatives.

    PubMed

    Wu, Chun-Zhen; Lai, Long; Hu, Xiao; Lei, Rong-Rong; Yang, Yi-Fang

    2013-09-01

    Tetrandrine possesses antitumor activity, however, only a few studies on its structure modification were reported. To improve the antitumor activity of tetrandrine, 20 new tetrandrine derivatives were designed and synthesized by Sonogashira and Suzuki reactions. Their antitumor activities were evaluated against three tumor cell lines including A549, HepG2, and BGC-823 by methyl thiazolyl tetrazolium assay with taxol as a positive control. The results showed that compounds 2c and 2g were highly potent against BGC-823 cell line, and compounds 1i and 1k showed particular activity against HepG2 cells. These results demonstrated that compounds 1i, 1k, 2c, and 2g were promising leads for further investigation. PMID:23944846

  2. Anticonvulsant activity of four oxygenated cannabidiol derivatives.

    PubMed

    Carlini, E A; Mechoulam, R; Lander, N

    1975-09-01

    A pharmacological comparison between cannabidiol (CBD) and four CBD derivatives, namely CBD-aldehyde-diacetate (I), 6-oxo-CBD-diacetate (II), 6-hydroxy-CBD-tri-acetate (III), and 9-hydroxy-CBD-triacetate (IV) was carried out in mice. Protection against maximal electroshock convulsions, potentiation of pentobarbital sleeping-time and reduction of spontaneous motor activity were the effects measured. All 5 compounds were equally potent in potentiating barbiturate sleeping time at doses ranging from 6.25 to 100 mg/kg. At 12.5 and 25 mg/kg only CBD and IV were able to decrease significantly the spontaneous motor activity. CBD, II, III and IV were also active in protecting mice against electroconvulsive shock at doses of 100-200 mg/kg, although at the larger dose CBD and compound II were the most efficient. Compound I was toxic, killing about half of the animals within 24 h after injection. PMID:1188178

  3. A negative derivative feedback design algorithm

    NASA Astrophysics Data System (ADS)

    Cola, F.; Resta, F.; Ripamonti, F.

    2014-08-01

    Vibration control logics based on the modal approach allow damping to be increased on a certain number of modes. The main limit associated with these strategies is represented by spillover on non-modelled modes. Negative derivative feedback (NDF) proves particularly robust against spillover since modal velocity is fed back through a band-pass filter so that undesired effects can be limited both at high and low frequencies. Unfortunately, the definition of the control gains for this logic is generally more difficult than other resonant controls owing to the lack of physical meaning. In this paper a design strategy for an NDF controller based on an optimal approach is proposed for single and multi-degrees of freedom systems and is tested on a cantilever beam finite element model.

  4. Synthesis of sulphonic acids and sultam derivatives

    Microsoft Academic Search

    Ibrahim Imam Ismail

    1990-01-01

    Reaction of propane-1,3-sultone with amines gave N-substituted aminosulphonic acids2a?i. Dehydration of2a?c with POCl3 gave the corresponding sultams3a?c. Propane-1,3-sultone1 reacted with tertury amines to give the betaiene salts4–11. 2,4-Dimethyl-1,3-butadiene-1,4-sultone12 condensed with amines to give N-substituted-2,4-dimethyl-1,3-butadiene-1,4-sultams13a and13b. The reaction of3a, 13a with hydrazine hydrate gave acid hydrazides3d or13c. Compounds3d, 13c reacted with isocyanates to yield urea derivatives14a?c, 15a?c.

  5. Synthesis and conformational analysis of naphthylnaphthoxazine derivatives

    NASA Astrophysics Data System (ADS)

    Tóth, Diána; Szatmári, István; Heydenreich, Matthias; Koch, Andreas; Kleinpeter, Erich; Fülöp, Ferenc

    2009-07-01

    Four new primary aminonaphthols ( 4, 5, 9 and 10) were synthesized from 1- or 2-naphthol and 1- or 2-naphthaldehyde via naphthoxazines in modified Mannich condensations. Simple ring-closure reactions of these aminonaphthols with paraformaldehyde, 4-nitrobenzaldehyde, phosgene or 4-chlorophenyl isothiocyanate led to new heterocyclic derivatives. In these transformations, either an sp 2 or an sp 3 carbon was inserted between the hydroxy and amino groups. The effects of substituents and the naphthyl ring on the conformation were investigated by means of NMR measurements, employing both dipolar and scalar couplings. The structures were confirmed by DFT quantum chemical calculations involving computed coupling constants, intramolecular distances between nuclei and the relative energies of the preferred conformers.

  6. New fluorescent nucleobases derived from 5-alkynylpyrimidines

    NASA Astrophysics Data System (ADS)

    Hudson, Robert H. E.; Dambenieks, Andrew K.; Moszynski, Joanne M.

    2005-09-01

    Fluorescent reporter groups are widely used in many areas of macromolecular science. In nucleic acid chemistry, fluorescently labeled oligonucleotides find use in the study of nucleic acid conformations, as reporters of the state of hybridization and as probes of nucleic acid-protein interactions, as well as, probes and primers for the detection and quantification of desired sequences. Often, the fluorophore is a separate and independent entity covalently attached to an otherwise unmodified oligonucleotide. Another class of fluorophore is the nucleobase analog - a chemically modified nucleobase that is unable to base pair properly. Recently, we have become interested in pyrrolocytosine (pC) as an intrinsically fluorescent, pairing-competent nucleobase. It has previously been shown that incorporation of pyrrolocytidine into oligonucleotides gives a fluorescent molecule that responds to the state of hybridization. We have refined the syntheses of pyrrolocytosine derivatives and the related modified uracil derivatives, furanouracil (fU), from cytosine and uracil respectively via three sequential steps: iodination of the nucleobase; Pd-catalyzed cross-coupling with a terminal alkyne; and metal-catalyzed cyclization. The fluorescence properties of the 5-alkynyl nucleobases and the bicyclic pC and fU analogs have been characterized and depend on: 1) the nature of the substituent on the alkyne, 2) whether the nucleobase is 5-alkynyl or cyclized, and 3) the presence of a substituent on the N1-position of the nucleobase. The chemistry and properties of peptide nucleic acid oligomers incorporating these types of base modifications and their possible use in point-mutation detection is presented.

  7. Revisiting satellite derived tropospheric NO2 trends

    NASA Astrophysics Data System (ADS)

    Richter, Andreas; Hilboll, Andreas; Burrows, John P.

    2015-04-01

    Nitrogen dioxide levels can be used as tracer of anthropogenic pollution as NOx, the sum of NO and NO2, is released during fossil fuel combustion. With its short atmospheric lifetime, atmospheric NO2 can be easily linked to its sources. Using its structured absorption cross section in the blue spectral region, NO2 amounts can be derived from measurements of backscattered solar radiation with the help of Differential Optical Absorption Spectroscopy measurements. Satellite retrievals of tropospheric NO2 became possible with the launch of the GOME instrument in 1995, and since then a series of instruments including SCIAMACHY, GOME-2 and OMI provide spectral data which can be used to quantify NO2 columns in the troposphere. Using these observations, spatial distributions of NO2, its sources and transport pathways as well as temporal changes have been investigated over the last years. In particular the latter have shown remarkable atmospheric developments with large reductions of NO2 levels in many industrialised countries and dramatic increases in regions with growing economies, most notably in China but also in many other countries. In this study, recent trends of satellite derived NO2 columns are evaluated using data from all available instruments with a focus on the last years. Combination of data taken from the two GOME-2 instruments and OMI improves coverage and sensitivity, and also provides important constraints on the reliability of the satellite data set. As in previous studies, large changes in NO2 columns are found in many regions, in particular over China where after two years of stagnating NO2 levels an unexpected substantial reduction is observed for 2014.

  8. Fluoride removal performance of glass derived hydroxyapatite

    SciTech Connect

    Liang, Wen, E-mail: wliang@ecust.edu.cn [Research Institute of Biomaterials, School of Materials Science and Engineering, East China University of Science and Technology (China)] [Research Institute of Biomaterials, School of Materials Science and Engineering, East China University of Science and Technology (China); Zhan, Lei; Piao, Longhua [Research Institute of Biomaterials, School of Materials Science and Engineering, East China University of Science and Technology (China)] [Research Institute of Biomaterials, School of Materials Science and Engineering, East China University of Science and Technology (China); Russel, Christian [Otto-Schott-Institut, Universitaet Jena, Jena (Germany)] [Otto-Schott-Institut, Universitaet Jena, Jena (Germany)

    2011-02-15

    Research highlights: {yields} Novel sodium calcium borate glass derived hydroxyapatite (G-HAP) is prepared. {yields} Micro-G-HAP adsorbs F{sup -} ions in solutions more effectively than commercial nano-HAP. {yields} The adsorption kinetics and isotherms are well fitted by a second order kinetic model and Freundlich isotherm model. -- Abstract: A novel sodium calcium borate glass derived hydroxyapatite (G-HAP) with different ranges of particle size was prepared by immersion sodium calcium borate glass in 0.1 M K{sub 2}HPO{sub 4} solution by the ratio of 50 g L{sup -1} for 7 days. The unique advantage of G-HAP for the adsorption of fluoride ions in solutions was studied. The effects of size and quantity of particles, pH value and adsorption time on adsorption performance were investigated. The maximum adsorption capacity was 17.34 mg g{sup -1} if 5 g L{sup -1}, <100 {mu}m G-HAP was added to a solution with an initial pH value of 6.72 and the adsorption time was 12 h. The results showed that the micro-G-HAP could immobilize F{sup -} in solution more effectively than commercial nano-HAP, which makes potential application of the G-HAP in removing the fluoride ions from wastewater. The adsorption kinetics and isotherms for F{sup -} could be well fitted by a second order kinetic model and Freundlich isotherm model respectively, which could be used to describe the adsorption behavior. The mechanism of G-HAP in immobilizing F{sup -} from aqueous solutions was investigated by the X-ray diffraction (XRD), infrared spectra (IR) and scanning electron microscopy (SEM).

  9. Mean value theorems for a matrix valued derivative

    Microsoft Academic Search

    John S. McMath; S. E. Sims

    1981-01-01

    The derivative of a function defined on a set of matrices is given utilizing the Moore-Penrose pseudoinverse, which yields a natural extension of differentiation in the univariate calculus. Several mean value theorems involving this derivative are established.

  10. 40 CFR 721.10328 - Salt of polyalkylenepolyamine derivative (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Salt of polyalkylenepolyamine derivative (generic...Specific Chemical Substances § 721.10328 Salt of polyalkylenepolyamine derivative (generic...chemical substance identified generically as salt of polyalkylenepolyamine...

  11. 40 CFR 721.10328 - Salt of polyalkylenepolyamine derivative (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Salt of polyalkylenepolyamine derivative (generic...Specific Chemical Substances § 721.10328 Salt of polyalkylenepolyamine derivative (generic...chemical substance identified generically as salt of polyalkylenepolyamine...

  12. 21 CFR 173.110 - Amyloglucosidase derived from Rhizopus niveus.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.110...derived from Rhizopus niveus. Amyloglucosidase enzyme product, consisting of enzyme derived from Rhizopus niveus, and...

  13. 21 CFR 173.110 - Amyloglucosidase derived from Rhizopus niveus.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.110...derived from Rhizopus niveus. Amyloglucosidase enzyme product, consisting of enzyme derived from Rhizopus niveus, and...

  14. 21 CFR 173.110 - Amyloglucosidase derived from Rhizopus niveus.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.110...derived from Rhizopus niveus. Amyloglucosidase enzyme product, consisting of enzyme derived from Rhizopus niveus, and...

  15. 21 CFR 173.110 - Amyloglucosidase derived from Rhizopus niveus.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.110...derived from Rhizopus niveus. Amyloglucosidase enzyme product, consisting of enzyme derived from Rhizopus niveus, and...

  16. Free radicals of benzo(a)pyrene and derivatives.

    PubMed Central

    Sullivan, P D

    1985-01-01

    The evidence for biological involvement, the spectroscopic properties (especially EPR), and the reactions, of free radicals derived from benzo(a)pyrene and its methylated, hydroxylated, and fluorinated derivatives are reviewed. PMID:3007095

  17. 21 CFR 184.1317 - Garlic and its derivatives.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...3 2014-04-01 2014-04-01 false Garlic and its derivatives. 184.1317 Section...Substances Affirmed as GRAS § 184.1317 Garlic and its derivatives. (a) Garlic is the fresh or dehydrated bulb or cloves...

  18. 21 CFR 184.1317 - Garlic and its derivatives.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...3 2011-04-01 2011-04-01 false Garlic and its derivatives. 184.1317 Section...Substances Affirmed as GRAS § 184.1317 Garlic and its derivatives. (a) Garlic is the fresh or dehydrated bulb or cloves...

  19. 21 CFR 184.1317 - Garlic and its derivatives.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...3 2012-04-01 2012-04-01 false Garlic and its derivatives. 184.1317 Section...Substances Affirmed as GRAS § 184.1317 Garlic and its derivatives. (a) Garlic is the fresh or dehydrated bulb or cloves...

  20. 77 FR 56067 - Changes To Implement Derivation Proceedings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-11

    ...proceeding and an opportunity for discovery. One comment suggested expanded discovery for derivations, since...allegation of derivation. Discovery prior to institution is...the respondent acquired knowledge of the claimed...

  1. 17 CFR 240.16b-6 - Derivative securities.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...Derivative securities. 240.16b-6 Section 240.16b-6 Commodity and Securities Exchanges...Section 16(b) § 240.16b-6 Derivative securities...purchases and sales of the same series of convertible debentures)...

  2. 17 CFR 240.16b-6 - Derivative securities.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...Derivative securities. 240.16b-6 Section 240.16b-6 Commodity and Securities Exchanges...Section 16(b) § 240.16b-6 Derivative securities...purchases and sales of the same series of convertible debentures)...

  3. 17 CFR 240.16b-6 - Derivative securities.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...Derivative securities. 240.16b-6 Section 240.16b-6 Commodity and Securities Exchanges...Section 16(b) § 240.16b-6 Derivative securities...purchases and sales of the same series of convertible debentures)...

  4. 17 CFR 240.16b-6 - Derivative securities.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...Derivative securities. 240.16b-6 Section 240.16b-6 Commodity and Securities Exchanges...Section 16(b) § 240.16b-6 Derivative securities...purchases and sales of the same series of convertible debentures)...

  5. 17 CFR 240.16b-6 - Derivative securities.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...Derivative securities. 240.16b-6 Section 240.16b-6 Commodity and Securities Exchanges...Section 16(b) § 240.16b-6 Derivative securities...purchases and sales of the same series of convertible debentures)...

  6. Higher Derivative Corrections to O-Plane Actions 

    E-print Network

    Wang, Zhao

    2014-11-17

    Higher derivative corrections to effective actions are very important and of great interest in string theory. The aim of this dissertation is to develop a method to constrain the higher derivative corrections to O-plane ...

  7. A general entry to C7-borono indole derivatives

    E-print Network

    Fenton, Owen S. (Owen Shea)

    2012-01-01

    The development of a methodology to access C7 pinacolatoboron substituted indole derivatives is described. It has been applied to indole, tryptophan, and tryptamine derivatives. Further functionalization to a C7 phenolic ...

  8. Characterization of Transport Proteins for Aromatic Compounds Derived from Lignin: Benzoate Derivative Binding Proteins

    PubMed Central

    Michalska, Karolina; Chang, Changsoo; Mack, Jamey C.; Zerbs, Sarah; Joachimiak, Andrzej; Collart, Frank R.

    2013-01-01

    In vitro growth experiments have demonstrated that aromatic compounds derived from lignin can be metabolized and represent a major carbon resource for many soil bacteria. However, the proteins that mediate the movement of these metabolites across the cell membrane have not been thoroughly characterized. To address this deficiency, we used a library representative of lignin degradation products and a thermal stability screen to determine ligand specificity for a set of solute-binding proteins (SBPs) from ATP-binding cassette (ABC) transporters. The ligand mapping process identified a set of proteins from Alphaproteobacteria that recognize various benzoate derivatives. Seven high-resolution crystal structures of these proteins in complex with four different aromatic compounds were obtained. The protein–ligand complexes provide details of molecular recognition that can be used to infer binding specificity. This structure–function characterization provides new insight for the biological roles of these ABC transporters and their SBPs, which had been previously annotated as branched-chain amino-acid-binding proteins. The knowledge derived from the crystal structures provides a foundation for development of sequencebased methods to predict the ligand specificity of other uncharacterized transporters. These results also demonstrate that Alphaproteobacteria possess a diverse set of transport capabilities for lignin-derived compounds. Characterization of this new class of transporters improves genomic annotation projects and provides insight into the metabolic potential of soil bacteria. PMID:22925578

  9. Characterizing Thematized Derivative Schema by the Underlying Emergent Structures

    ERIC Educational Resources Information Center

    Garcia, Mercedes; Llinares, Salvador; Sanchez-Matamoros, Gloria

    2011-01-01

    This paper reports on different underlying structures of the derivative schema of three undergraduate students that were considered to be at the trans level of development of the derivative schema (action-process-object-schema). The derivative schema is characterized in terms of the students' ability to explicitly transfer the relationship between…

  10. Simplified Derivation of the Fokker-Planck Equation.

    ERIC Educational Resources Information Center

    Siegman, A. E.

    1979-01-01

    Presents an alternative derivation of the Fokker-Planck equation for the probability density of a random noise process, starting from the Langevin equation. The derivation makes use of the first two derivatives of the Dirac delta function. (Author/GA)

  11. Exact Multisoliton Solutions of General Nonlinear Schrödinger Equation with Derivative

    PubMed Central

    Li, Qi; Duan, Qiu-yuan; Zhang, Jian-bing

    2014-01-01

    Multisoliton solutions are derived for a general nonlinear Schrödinger equation with derivative by using Hirota's approach. The dynamics of one-soliton solution and two-soliton interactions are also illustrated. The considered equation can reduce to nonlinear Schrödinger equation with derivative as well as the solutions. PMID:25013858

  12. Original article Stability of milk-derived calcium

    E-print Network

    Paris-Sud XI, Université de

    Original article Stability of milk-derived calcium phosphate suspensions Skelte G. ANEMA* Fonterra January 2009 Abstract ­ Milk-derived calcium phosphate (MDCP) can be isolated from whey derived from acid casein or cottage cheese manufacture as a precipitated calcium phosphate material. However

  13. Derivation and definition of a linear aircraft model

    NASA Technical Reports Server (NTRS)

    Duke, Eugene L.; Antoniewicz, Robert F.; Krambeer, Keith D.

    1988-01-01

    A linear aircraft model for a rigid aircraft of constant mass flying over a flat, nonrotating earth is derived and defined. The derivation makes no assumptions of reference trajectory or vehicle symmetry. The linear system equations are derived and evaluated along a general trajectory and include both aircraft dynamics and observation variables.

  14. Bio-Derived Liquids to Hydrogen Distributed Reforming Targets

    E-print Network

    Bio-Derived Liquids to Hydrogen Distributed Reforming Targets Arlene F. Anderson Technology and Infrastructure Technologies Program Bio-Derived Liquids to Hydrogen Distributed Reforming Working Group and Hydrogen Production Technical Team Review November 6, 2007 #12;Bio-Derived Liquids to Hydrogen Distributed

  15. MECHANICAL PROPERTY CHARACTERIZATION OF SOL-GEL DERIVED NANOMATERIALS

    E-print Network

    Brinker, C. Jeffrey

    MECHANICAL PROPERTY CHARACTERIZATION OF SOL-GEL DERIVED NANOMATERIALS USING AN ACOUSTIC WAVE;#12;For my Terra........ iii #12;MECHANICAL PROPERTY CHARACTERIZATION OF SOL-GEL DERIVED NANOMATERIALS, New Mexico November 2006 #12;Mechanical Property Characterization of Sol-gel Derived Nanomaterials

  16. Pricing Derivatives on Financial Securities Subject to Credit Risk

    Microsoft Academic Search

    Robert A. Jarrow; Stuart M. Turnbull

    1995-01-01

    This article provides a new methodology for pricing and hedging derivative securities involving credit risk. Two types of credit risks are considered. The first is where the asset underlying the derivative security may default. The second is where the writer of the derivative security may default. The authors apply the foreign currency analogy of R. Jarrow and S. Turnbull (1991)

  17. Kinetic Theory Derivation of the Adiabatic Law for Ideal Gases.

    ERIC Educational Resources Information Center

    Sobel, Michael I.

    1980-01-01

    Discusses how the adiabatic law for ideal gases can be derived from the assumption of a Maxwell-Boltzmann (or any other) distribution of velocities--in contrast to the usual derivations from thermodynamics alone, and the higher-order effect that leads to one-body viscosity. An elementary derivation of the adiabatic law is given. (Author/DS)

  18. Boolean Derivatives With Application to Edge Detection for Imaging Systems

    Microsoft Academic Search

    Sos S. Agaian; Karen A. Panetta; Shahan C. Nercessian; Ethan E. Danahy

    2010-01-01

    This paper introduces a new concept of Boolean derivatives as a fusion of partial derivatives of Boolean functions (PDBFs). Three efficient algorithms for the calculation of PDBFs are presented. It is shown that Boolean function derivatives are useful for the application of identifying the location of edge pixels in binary images. The same concept is extended to the development of

  19. Synthesis of steroidal 17 beta-carboxamide derivatives.

    PubMed

    Formstecher, P; Lustenberger, P; Dautrevaux, M

    1980-03-01

    Several 17 beta-carboxamide derivatives of natural and fluorinated glucocorticoids have been synthesized. The 17 beta-carboxylic derivatives were obtained by periodic acid oxidation of their side chains. They were then activated by N-hydroxybenzotriazole (HOBT) and coupled to several primary amines. Using this method eleven 17 beta-carboxamide derivatives have been prepared in good yields. PMID:7376221

  20. Thermodynamic Derivation of the Equilibrium Distribution Functions of Statistical Mechanics.

    ERIC Educational Resources Information Center

    Stoeckly, Beth

    1979-01-01

    Presents a simplified derivation of the equilibrium distribution functions. The derivation proceeds from the change in the Helmholtz free energy when a particle is added to a system of fixed temperature, volume, and chemical potential. The derivations show the relationship between statistical mechanics and macroscopic thermodynamics. (Author/GA)

  1. Resurgence, Stokes phenomenon and alien derivatives for levelone linear

    E-print Network

    Resurgence, Stokes phenomenon and alien derivatives for level­one linear di#erential systems. Mich of alien derivatives. We make explicit the Stokes­Ramis matrices as functions of the connection constants, summability, resurgence, alien derivatives. AMS classification: 34M03, 34M30, 34M35, 34M40. 1 #12; Loday

  2. Derivation of the Freundlich Adsorption Isotherm from Kinetics

    ERIC Educational Resources Information Center

    Skopp, Joseph

    2009-01-01

    The Freundlich adsorption isotherm is a useful description of adsorption phenomena. It is frequently presented as an empirical equation with little theoretical basis. In fact, a variety of derivations exist. Here a new derivation is presented using the concepts of fractal reaction kinetics. This derivation provides an alternative basis for…

  3. Thymol derivatives from hairy roots of Arnica montana.

    PubMed

    Weremczuk-Jezyna, I; Kisiel, W; Wysoki?ska, H

    2006-09-01

    Five known thymol derivatives were isolated from roots of Arnica montana transformed with Agrobacterium rhizogenes LBA 9402. The compounds were characterized by spectral methods. The pattern of thymol derivatives in light-grown hairy roots was slightly different from that in dark-grown ones. This is the first report on the presence of thymol derivatives in hairy roots of the plant. PMID:16586074

  4. Polyketides from a Marine-Derived Fungus Xylariaceae sp.

    PubMed Central

    Nong, Xu-Hua; Zheng, Zhi-Hui; Zhang, Xiao-Yong; Lu, Xin-Hua; Qi, Shu-Hua

    2013-01-01

    Eighteen polyketides (1–18) including six citrinin derivatives, two phenol derivatives, one cyclopentenone, two naphthol derivatives, and seven tetralone derivatives were isolated from the culture broth of a marine-derived fungal strain Xylariaceae sp. SCSGAF0086. Five of these compounds (1, 2, 8, 9, and 10) were new, and their structures were determined by spectroscopic methods. Compounds 4, 6, 7, and 17 showed enzyme-inhibitory activities towards several tested enzymes, and 6 and 7 showed strong antifouling activity against Bugula neritina larvae settlement. This is the first time that the antifouling and enzyme-inhibitory activities of these compounds has been reported. PMID:23697953

  5. Polyketides from a marine-derived fungus Xylariaceae sp.

    PubMed

    Nong, Xu-Hua; Zheng, Zhi-Hui; Zhang, Xiao-Yong; Lu, Xin-Hua; Qi, Shu-Hua

    2013-05-01

    Eighteen polyketides (1-18) including six citrinin derivatives, two phenol derivatives, one cyclopentenone, two naphthol derivatives, and seven tetralone derivatives were isolated from the culture broth of a marine-derived fungal strain Xylariaceae sp. SCSGAF0086. Five of these compounds (1, 2, 8, 9, and 10) were new, and their structures were determined by spectroscopic methods. Compounds 4, 6, 7, and 17 showed enzyme-inhibitory activities towards several tested enzymes, and 6 and 7 showed strong antifouling activity against Bugula neritina larvae settlement. This is the first time that the antifouling and enzyme-inhibitory activities of these compounds has been reported. PMID:23697953

  6. Evaluation of importance of lateral acceleration derivatives in extraction of lateral-directional derivatives at high angles of attack

    NASA Technical Reports Server (NTRS)

    Nguyen, L. T.

    1974-01-01

    A theoretical investigation was conducted to determine the importance of the lateral acceleration (beta) derivatives in the extraction of lateral-directional stability derivatives for swept wing airplanes at high angles of attack. Representative values of lateral acceleration derivatives in yaw and roll (Cn beta and Cl beta) were used in a computer program to generate representative flight motions at several angles of attack and altitudes. The computer-generated motions were then subjected to a parameter identification process based on a modified Newton-Raphson method. Two identification techniques were evaluated, one which included the beta derivatives and one which neglected them. The results of the study indicate that omission of the beta derivatives from mathematical models used in the derivative-extraction techniques can produce erroneous values for the lateral-directional stability derivatives particularly at high angles of attack, where the beta derivatives are large. The largest errors occur in the dynamic derivatives, but large errors may also occur in the static derivatives for cases in which the beta derivatives have large effects on the flight motions of the airplane. In addition, the resulting identified mathematical models provide poor motion prediction as well as erroneous predictions of dynamic modal characteristics. These results strongly indicate that the effects of beta derivatives should be considered in any attempt to extract lateral-directional aerodynamic parameters at high angles of attack.

  7. Cerebrovascular and Neuroprotective Effects of Adamantane Derivative

    PubMed Central

    Mirzoyan, Ruben S.; Gan'shina, Tamara S.; Maslennikov, Denis V.; Kovalev, Georgy I.; Zimin, Ivan A.; Pyatin, Boris M.; Avdyunina, Nina I.; Kukhtarova, Anna M.; Khostikyan, Nelly G.; Meliksetyan, Vahe S.; Alikhanyan, Cristina B.; Mirzoyan, Narine R.

    2014-01-01

    Objectives. The influence of 5-hydroxyadamantane-2-on was studied on the rats' brain blood flow and on morphological state of brain tissue under the condition of brain ischemia. The interaction of the substance with NMDA receptors was also studied. Methods. Study has been implemented using the methods of local blood flow registration by laser flowmeter, [3H]-MK-801binding, and morphological examination of the brain tissue. We used the models of global transient ischemia of the brain, occlusion of middle cerebral artery, and hypergravity ischemia of the brain. Results. Unlike memantine, antagonist of glutamatergic receptors, the 5-hydroxyadamantane-2-on does not block NMDA receptors but enhances the cerebral blood flow of rats with brain ischemia. This effect is eliminated by bicuculline. Under conditions of permanent occlusion of middle cerebral artery, 5-hydroxyadamantane-2-on has recovered compensatory regeneration in neural cells, axons, and glial cells, and the number of microcirculatory vessels was increased. 5-Hydroxyadamantane-2-on was increasing the survival rate of animals with hypergravity ischemia. Conclusions. 5-Hydroxyadamantane-2-on, an adamantane derivative, which is not NMDA receptors antagonist, demonstrates significant cerebrovascular and neuroprotective activity in conditions of brain ischemia. Presumably, the GABA-ergic system of brain vessels is involved in mechanisms of cerebrovascular and neuroprotective activity of 5-hydroxyadamantane-2-on. PMID:24772429

  8. Catanionic gels based on cholic acid derivatives.

    PubMed

    di Gregorio, M Chiara; Pavel, N Viorel; Miragaya, Javier; Jover, Aida; Meijide, Francisco; Vázquez Tato, José; Tellini, Victor H Soto; Galantini, Luciano

    2013-10-01

    In this paper, the preparation and characterization of an anionic and a cationic surfactant obtained by chemical modifications of a natural bile acid (cholic acid) are reported. The bile acid was modified by introducing a diamine or a dicarboxylic aromatic residue on the lateral chain. The pure cationic surfactant self-assembles in a network of fibers with a cross-section gyration radius of about 15.1 Å, providing hydrogels with a pH-dependent compactness. On the other hand, the anionic molecule gives rise to prolate ellipsoid micelles. Homogeneous catanionic mixtures have also been obtained, with molar fraction of each surfactant ranging from 0.125 to 0.875. At total surfactant concentration of 0.05% (w/v), the mixtures form gels of fibrils partially arranged in secondary twisted superstructures. Comparison of this concentration with the minimum gelation concentration of the pure cationic derivative (0.16% w/v) suggests that, in the mixtures, the presence of the electrostatic component in self-assembly of the molecules allows the formation of gels starting from more dilute samples. In view of these achievements, this work suggests that catanionic mixtures can be exploited to enhance the efficiency of gelators. PMID:24063307

  9. Latent Heating Structures Derived from TRMM

    NASA Technical Reports Server (NTRS)

    Tao, W.-K.; Smith, E. A.; Adler, R.; Hou, A.; Kakar, R.; Krishnamurti, T.; Kummerow, C.; Lang, S.; Olson, W.; Satoh, S.

    2004-01-01

    Rainfall is the fundamental variable within the Earth's hydrological cycle because it is both the main forcing term leading to variations in continental and oceanic surface water budgets. The vertical distribution of latent heat release, which is accompanied with rain, modulates large-scale meridional and zonal circulations within the tropics as well as modifying the energetic efficiency of mid-latitude weather systems. Latent heat release itself is a consequence of phase changes between the vapor, liquid, and frozen states of water.This paper focuses on the retrieval of latent heat release from satellite measurements generated by the Tropical Rainfall Measuring Mission 0. The TRMM observatory, whose development was a joint US-Japan space endeavor, was launched in November 1997. TRMM measurements provide an accurate account of rainfall over the global tropics, information which can be .used to estimate the four-dimensional structure of latent heating across the entire tropical and sub-tropical regions. Various algorithm methodologies for estimating latent heating based on rain rate measurements from TRMM observations are described. The strengths and weaknesses of these algorithms, as well as the latent heating products generated by these algorithms, are also discussed along with validation analyses of the products. The investigation paper provides an overview of how TRMM-derived latent heating information is currently being used in conjunction with global weather and climate models, and concludes with remarks designed to stimulate further research on latent heating retrieval

  10. Ultralow thermal conductivity of fullerene derivatives

    NASA Astrophysics Data System (ADS)

    Wang, Xiaojia; Liman, Christopher D.; Treat, Neil D.; Chabinyc, Michael L.; Cahill, David G.

    2013-08-01

    Recently, Duda [J. C. Duda, P. E. Hopkins, Y. Shen, and M. C. Gupta, Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.110.015902 110, 015902 (2013)] reported that the fullerene derivative [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) has the lowest thermal conductivity ? ever observed in a fully dense solid, ? ? 0.03 W m-1 K-1. We have investigated a variety of phases and microstructures of PCBM and the closely related compound [6,6]-phenyl-C61-butyric acid n-butyl ester (PCBNB) and find that the thermal conductivities of PCBM and PCBNB films are mostly limited to the range 0.05 < ? < 0.06 W m-1 K-1 with a few samples having slightly higher ?. The conductivities we observe are ?70% larger than reported by Duda but are still “ultralow” in the sense that the thermal conductivity is a factor of ?3 below the conductivity predicted by the minimum thermal conductivity model using an estimate of the thermally excited modes per molecule.

  11. Overtone spectroscopy of chlorine substituted benzene derivatives.

    PubMed

    Dwivedi, Y; Thakur, S N; Rai, S B

    2009-01-01

    The absorption spectra of di-, tri- and tetra-derivatives of chlorobenzene have been studied in their pure form in the spectral range 400-20,000 cm(-1). A large number of bands associated with the fundamental, the overtones and the combination frequencies of C-H stretching mode have been observed. Vibrational frequencies, anharmonicity constants and dissociation energies, for the C-H stretch vibrations for the six molecules have been determined using local mode model. The C-H stretch frequencies obtained from experiments are compared with the corresponding frequency determined theoretically using RHF and DFT methods with same 6-31+G* basis set. This information has been used for the assignment of several combination bands as well as some weak overtone bands. Effect of hydrogen atom substitution by chlorine atom has been studied by measuring changes in the vibrational frequency of the C-H stretching mode and the C-H bond length. Frequency changes have been well correlated with the change in charge density on carbon as well as chlorine atoms. PMID:18760956

  12. Overtone spectroscopy of chlorine substituted benzene derivatives

    NASA Astrophysics Data System (ADS)

    Dwivedi, Y.; Thakur, S. N.; Rai, S. B.

    2009-01-01

    The absorption spectra of di-, tri- and tetra-derivatives of chlorobenzene have been studied in their pure form in the spectral range 400-20,000 cm -1. A large number of bands associated with the fundamental, the overtones and the combination frequencies of C sbnd H stretching mode have been observed. Vibrational frequencies, anharmonicity constants and dissociation energies, for the C sbnd H stretch vibrations for the six molecules have been determined using local mode model. The C sbnd H stretch frequencies obtained from experiments are compared with the corresponding frequency determined theoretically using RHF and DFT methods with same 6-31 + G* basis set. This information has been used for the assignment of several combination bands as well as some weak overtone bands. Effect of hydrogen atom substitution by chlorine atom has been studied by measuring changes in the vibrational frequency of the C sbnd H stretching mode and the C sbnd H bond length. Frequency changes have been well correlated with the change in charge density on carbon as well as chlorine atoms.

  13. Chlorinated tyrosine derivatives in insect cuticle.

    PubMed

    Andersen, Svend Olav

    2004-10-01

    A method for quantitative measurement of 3-monochlorotyrosine and 3,5-dichlorotyrosine in insect cuticles is described, and it is used for determination of their distribution in various cuticular regions in nymphs and adults of the desert locust, Schistocerca gregaria. The two chlorinated tyrosine derivatives were present in all analyzed regions in mature adult locusts, the highest concentrations were found in the sclerotized cuticle of femur and tibia, but significant amounts were also present in the unsclerotized arthrodial membranes. Small amounts of the two amino acids were obtained from pharate, not-yet sclerotized cuticle of adult femur and tibia, the amounts increased rapidly during the first 24 h after ecdysis and more slowly during the next two weeks. Control analyses using stable isotope dilution mass spectrometry have confirmed that the chlorinated tyrosines are not artifacts formed during sample hydrolysis. Mono- and dichlorotyrosine are also present in cuticular samples from other insect species, such as the beetle, Tenebrio molitor, the moth Hyalophora cecropia, the cockroach Blaberus craniifer, and the bug Rhodnius prolixus, but not in the sclerotized puparial cuticle of the blowfly, Calliphora vicina, or in sclerotized ootheca from the cockroach, Periplaneta americana. Cuticular sclerotization and formation of chlorotyrosines occur simultaneously in locust legs; sclerotized cuticles tend to have a higher content of chlorotyrosines than unsclerotized cuticles, but it is concluded that the chlorotyrosines are not just a by-product from the sclerotization process. PMID:15475302

  14. Antioxidant activities of licorice-derived prenylflavonoids

    PubMed Central

    Kim, Hyo Jung; Seo, Ji-Yeon; Suh, Hwa-Jin; Lim, Soon Sung

    2012-01-01

    Glycyrrhiza uralensis (or licorice) is a widely used Oriental herbal medicine from which the phenylflavonoids dehydroglyasperin C (DGC), dehydroglyasperin D (DGD), and isoangustone A (IsoA) are derived. The purpose of the present study was to evaluate the antioxidant properties of DGC, DGD, and IsoA. The three compounds showed strong ferric reducing activities and effectively scavenged DPPH, ABTS+, and singlet oxygen radicals. Among the three compounds tested, DGC showed the highest free radical scavenging capacity in human hepatoma HepG2 cells as assessed by oxidant-sensitive fluorescent dyes dichlorofluorescein diacetate and dihydroethidium bromide. In addition, all three compounds effectively suppressed lipid peroxidation in rat tissues as well as H2O2-induced ROS production in hepatoma cells. This study demonstrates that among the three phenylflavonoids isolated from licorice, DGC possesses the most potent antioxidant activity, suggesting it has protective effects against chronic diseases caused by reactive oxygen species as well as potential as an antioxidant food additive. PMID:23346298

  15. Cloned mice derived from somatic cell nuclei.

    PubMed

    Hosaka, K; Ohi, S; Ando, A; Kobayashi, M; Sato, K

    2000-12-01

    In 1997, a cloned sheep "Dolly" was produced by nuclear transfer of somatic cell. The first birth of cloned mice derived from some somatic cells were succeeded in 1998. At present, it is shown that somatic cells, cumulus cells, fibroblasts and Sertoli cells can be used to the study of cloned animal as nuclear donor. In this study investigation was designed to compare with efficiency on the production of cloned embryos by using the microinjection and the electrofusion methods for nuclear transfer. Oocyte enucleation was performed with a micromanipulator. The oocyte was held by holding pipette, and was enucleated using a beveled pipette. Microinjection method: Cell's nucleus injection was carried out by piezo-micromanipulator. Cytochalasin B treated cumulus cell was aspirated into a injection pipette, and was broken its plasma membrane using the injection pipette. Then, the cumulus cell was injected into the enucleated ooplasm directly. Electrofusion method: The cell was aspirated into a beveled pipette, and then an aspirated cell was inserted into perivitelline space. Then, the pair of enucleated oocyte and cell was fused using electrical cell fusion apparatus. The reconstituted embryos were activated after nuclear transfer using St2+. Reconstituted embryos had been produced by the microinjection showed the embryonic development to over 8-cell stages. But, the rate of fragmentation of reconstituted embryos by the microinjection showed a little high rate in comparison with the electrofusion. When some reconstituted embryos by the microinjection were transplanted to pseudopregnant females' oviduct, 9 fetuses were observed at 14 days post coitum. PMID:11329940

  16. Jet flames of a refuse derived fuel

    SciTech Connect

    Weber, Roman; Kupka, Tomasz; Zajac, Krzysztof [Institute of Energy Process Engineering and Fuel Technology, Clausthal University of Technology, Agicolastrasse 4, 38 678 Clausthal-Zellerfeld (Germany)

    2009-04-15

    This paper is concerned with combustion of a refuse derived fuel in a small-scale flame. The objective is to provide a direct comparison of the RDF flame properties with properties of pulverized coal flames fired under similar boundary conditions. Measurements of temperature, gas composition (O{sub 2}, CO{sub 2}, CO, NO) and burnout have demonstrated fundamental differences between the coal flames and the RDF flames. The pulverized coals ignite in the close vicinity of the burner and most of the combustion is completed within the first 300 ms. Despite the high volatile content of the RDF, its combustion extends far into the furnace and after 1.8 s residence time only a 94% burnout has been achieved. This effect has been attributed not only to the larger particle size of fluffy RDF particles but also to differences in RDF volatiles if compared to coal volatiles. Substantial amounts of oily tars have been observed in the RDF flames even though the flame temperatures exceeded 1300 C. The presence of these tars has enhanced the slagging propensity of RDF flames and rapidly growing deposits of high carbon content have been observed. (author)

  17. Prediction of thermodynamic properties of coal derivatives

    SciTech Connect

    Donohue, M.D.

    1990-09-01

    The purpose of this research program is to understand the relationship between macroscopic thermodynamic properties and the various types of intermolecular forces. Since coal-derived liquids contain a wide variety of compounds, a theory capable of successfully predicting the thermophysical properties for coal processes must take into account the molecular shapes and all significant intermolecular forces: dispersion forces, anisotropic forces due to dipoles and quadrupoles, as well as Lewis acid-base interactions. We have developed the Acid-Base-Perturbed-Anisotropic-Chain Theory (ABPACT), a comprehensive theory that is capable of predicting the thermophysical properties for many systems where these different intermolecular forces are present. The ABPACT can treat non-polar compounds, polar compounds and compounds that associate through Lewis acid-base interactions. In addition to our theoretical work, we have used computer simulations to evaluate (and in some cases correct) the assumptions made in this theory. We also have conducted experiments to help us better understand the interplay of different kinds of interactions in multicomponent mixtures.

  18. Polyimides Derived from Novel Asymmetric Dianhydrides

    NASA Technical Reports Server (NTRS)

    Chuang, Chun-Hua (Inventor)

    2012-01-01

    This invention relates to the compositions and processes for preparing thermoset and thermoplastic polyimides derived from novel asymmetrical dianhydrides: specifically 2,3,3',4' benzophenone dianhydride (a-BTDA), and 3,4'-(hexafluoroisopropylidene)diphthalic anhydride (a-6FDA). The a-BTDA anhydride is prepared by Suzuki coupling with catalysts from a mixed anhydride of 3,4-dimethylbenzoic acid or 2,3-dimethylbenzoic acid with 2,3-dimethylphenylboronic acid or 3,4-dimethylphenylboronic acid respectively, to form 2,3,3',4'-tetramethylbenzophenone which is oxidized to form 2,3,3',4'-benzophenonetetracarboxylic acid followed by cyclodehydration to obtain a-BTDA. The a-6FDA is prepared by nucleophilic triflouoromethylation of 2,3,3',4'-tetramethylbenzophenone with trifluoromethyltrimethylsilane to form 3,4'-(trifluoromethylmethanol)-bis(o-xylene) which is converted to 3,4'-(hexafluoroisopropylidene-bis(o-xylene). The 3,4'-(hexafluoroisopropylidene)-bis(o-xylene) is oxidized to the corresponding tetraacid followed by cyclodehydration to yield a-6FDA.

  19. Intrinsic Magnetic Properties of L10 Derivates

    NASA Astrophysics Data System (ADS)

    Skomski, Ralph; Manchanda, Priyanka; Sahota, Pankaj K.; Kashyap, Arti; Balasubramanian, Balamurugan; Shield, J. E.; Sellmyer, D. J.

    2012-02-01

    It is investigated how atomic substitutions modify the magnetization, exchange and anisotropy of L10-ordered ferromagnets. Emphasis is on properties of interest in permanent magnetism, including the reduction of raw-materials costs by substituting iron-series transition metals for expensive heavy (4d/5d) transition-metal elements. In particular, VASP calculations are used to determine the magnetizations of the Fe-Co-Pt, Mn-Al-C and Fe-Ni-S systems. We perform supercell calculations to determine the moments of Fe and Co in various L10 derivates with chemical disorder. The local magnetic moments exhibit a subtle dependence on the environment, not only in each Fe-Co layer but also through alternating 4d/5d layers. However, the magnitude of these spatial fluctuations is not very large, and after configurational averaging, the moments exhibit very simple dependencies on the concentrations of the involved atoms. The FeNi system is also interesting because L10-ordered FeNi was originally discovered in meteorites (tetrataenite), formed with cooling times in excess of one million years.

  20. Derived relations and generalized alteration of preferences.

    PubMed

    Valdivia-Salas, Sonsoles; Dougher, Michael J; Luciano, Carmen

    2013-06-01

    The present study examined the role of derived relations in the generalizability of the evaluative conditioning effect. Healthy university students participated. Four geometrical shapes were first established as discriminative stimuli for the contingent presentation of pictograms (B1, B2, C1, and C2, respectively). We then assessed the reinforcing properties of B1 versus B2, and C1 versus C2 by using simultaneous discrimination tasks: at baseline (baseline assessment), after pairing B1 with aversive slides plus noise and B2 with pleasant slides (test I), and after employing equivalence training and testing to establish B1 as equivalent to C1 and B2 as equivalent to C2 (test II). Most participants (82%) in the experimental condition, as compared with the control conditions (17% and 10%), selected the discriminative shapes for B2 (test I) and C2 (test II) on most trials, replicating and extending previous findings. Subsequently, the geometrical shapes were established as equivalent to the letters X, Y, W, and Z, respectively, which then served as antecedent stimuli in simultaneous discrimination tasks as before (test III). As was expected, only participants in the experimental condition showed preference for the novel letters that were established as equivalent to B2-producing and C2-producing shapes. These findings suggest that the evaluative conditioning effect may extend far beyond the stimulus being de/valuated and narrow the behavioral repertoire. PMID:23242738

  1. Aggregation susceptibility on phototransformation of hematoporphyrin derivatives

    NASA Astrophysics Data System (ADS)

    Menezes, P. F. C.; Imasato, H.; Ferreira, J.; Bagnato, V. S.; Sibata, C. H.; Perussi, J. R.

    2008-03-01

    Photosensitizers used in PDT suffer degradation by light. In this work, photobleaching of Photogem® (PG), Photofrin® (PF), and Photosan® (PS), hematoporphyrin derivatives, were induced by light in the presence or absence of 1% Triton X-100. The degradation efficiency in the absence of 1% Triton X-100 follows the sequence: PF > PG > PS, which means that PF presented a greater degradation than PG and PS. However, in the presence of the surfactant the degradation efficiency is different: PG cong PS > PF. Besides aggregation susceptibility, studies in cell culture (tumor and non tumor cells) and in animals (depth of necrosis) were performed, trying to correlate the stability of these photosensitizers with their photodynamic effect. The results suggest that PF presents higher light induced photocytotoxicity than PG and PS for both types of cells. For the depth of necrosis studies, more aggregated photosensitizer showed a longer time to accumulate in liver (30 min for PG, 120 h for PF, and 720 h for PS). Then, to establish an ideal dosimetry in PDT, one must consider the intrinsic physical chemistry characteristics of the photosensitizer as well as their ability to undergo photobleaching.

  2. Plant-derived biomolecules in fermented cabbage.

    PubMed

    Tolonen, Marja; Taipale, Marianne; Viander, Britta; Pihlava, Juha-Matti; Korhonen, Hannu; Ryhänen, Eeva-Liisa

    2002-11-01

    The formation of plant-derived biomolecules during sauerkraut fermentation was studied. Cabbage was fermented with a starter culture, and the results were compared to the results of spontaneous fermentation. The concentration of flavonoids and glucosinolates was analyzed by HPLC, and that of the glucosinolate breakdown products, by GC-MS. Of the 20 different flavonoids tested, only kaempferol was found (0.9 mg/ kg FW, fresh weight). The content of kaempferol remained constant in the cabbage fiber matrix over the fermentation process. The nitrite concentration was below the detection limit in both fermentations. The total glucosinolate content in the raw material was 3.71 micro mol/g DW, dry weight. Glucosinolates were totally decomposed in both fermentations during two weeks, and different types of breakdown products were formed. Isothiocyanates, indole-3-carbinol, goitrin, allyl cyanide, and nitriles were determined in the fermented cabbage. Isothiocyanates and allyl cyanide were the predominant breakdown products in both fermentations. Sulforaphane nitrile and goitrin were found only in small quantities in the end products. PMID:12405778

  3. Amino acids derived from Titan tholins

    NASA Technical Reports Server (NTRS)

    Khare, B. N.; Sagan, C.; Ogino, H.; Nagy, B.; Er, C.; Schram, K. H.; Arakawa, E. T.

    1986-01-01

    An organic heteropolymer (Titan tholin) was produced by continuous dc discharge through a 0.9 N2/0.1 CH4 gas mixture at 0.2 mbar pressure, roughly simulating the cloudtop atmosphere of Titan. Treatment of this tholin with 6N HCl yielded 16 amino acids by gas chromatography after derivatization of N-trifluroacetyl isopropyl esters on two different capillary columns. Identifications were confirmed by GC/MS. Glycine, aspartic acid, and alpha- and beta-alanine were produced in greatest abundance; the total yield of amino acids was approximately 10(-2), approximately equal to the yield of urea. The presence of "nonbiological" amino acids, the absence of serine, and the fact that the amino acids are racemic within experimental error together indicate that these molecules are not due to microbial or other contamination, but are derived from the tholin. In addition to the HCN, HC2CN, and (CN)2 found by Voyager, nitriles and aminonitriles should be sought in the Titanian atmosphere and, eventually, amino acids on the surface. These results suggest that episodes of liquid water in the past or future of Titan might lead to major further steps in prebiological organic chemistry on that body.

  4. Metalloprotease Dependent Release of Placenta Derived Fractalkine

    PubMed Central

    Siwetz, Monika; Blaschitz, Astrid; Kremshofer, Julia; Bilic, Jelena; Desoye, Gernot; Huppertz, Berthold; Gauster, Martin

    2014-01-01

    The chemokine fractalkine is considered as unique since it exists both as membrane-bound adhesion molecule and as shed soluble chemoattractant. Here the hypothesis was tested whether placental fractalkine can be shed and released into the maternal circulation. Immunohistochemical staining of human first trimester and term placenta sections localized fractalkine at the apical microvillous plasma membrane of the syncytiotrophoblast. Gene expression analysis revealed abundant upregulation in placental fractalkine at term, compared to first trimester. Fractalkine expression and release were detected in the trophoblast cell line BeWo, in primary term trophoblasts and placental explants. Incubation of BeWo cells and placental explants with metalloprotease inhibitor Batimastat inhibited the release of soluble fractalkine and at the same time increased the membrane-bound form. These results demonstrate that human placenta is a source for fractalkine, which is expressed in the syncytiotrophoblast and can be released into the maternal circulation by constitutive metalloprotease dependent shedding. Increased expression and release of placental fractalkine may contribute to low grade systemic inflammatory responses in third trimester of normal pregnancy. Aberrant placental metalloprotease activity may not only affect the release of placenta derived fractalkine but may at the same time affect the abundance of the membrane-bound form of the chemokine. PMID:24771984

  5. Effects of sulfate chitosan derivatives on nonalcoholic fatty liver disease

    NASA Astrophysics Data System (ADS)

    Yu, Mingming; Wang, Yuanhong; Jiang, Tingfu; Lv, Zhihua

    2014-06-01

    Sulfate chitosan derivatives have good solubility and therapeutic effect on the cell model of NAFLD. The aim of this study was to examine the therapeutic effect of sulfate chitosan derivatives on NAFLD. The male Wistar rats were orally fed high fat emulsion and received sulfate chitosan derivatives for 5 weeks to determine the pre-treatment effect of sulfate chitosan derivatives on NAFLD. To evaluate the therapeutic effect of sulfate chitosan derivatives on NAFLD, the rats were orally fed with high concentration emulsion for 5 weeks, followed by sulfate chitosan derivatives for 3 weeks. Histological analysis and biomedical assays showed that sulfate chitosan derivatives can dramatically prevent the development of hepatic steatosis in hepatocyte cells. In animal studies, pre-treatment and treatment with sulfate chitosan derivatives significantly protected against hepatic steatohepatitis induced by high fat diet according to histological analysis. Furthermore, increased TC, ALT, MDA, and LEP in NAFLD were significantly ameliorated by pre-treatment and treatment with sulfate chitosan derivatives. Furthermore, increased TG, AST, and TNF-? in NAFLD were significantly ameliorated by treatment with sulfate chitosan derivatives. Sulfate chitosan derivatives have good pre-treatment and therapeutic effect on NAFLD.

  6. Effects of thienodiazepine derivatives on human sleep as compared to those of benzodiazepine derivatives.

    PubMed

    Nakazawa, Y; Kotorii, M; Oshima, M; Horikawa, S; Tachibana, H

    1975-10-31

    The effects of new thienodiazepine derivatives, such as clotiazepam and Y-7131, on normal human sleep were investigated on 5 subjects and compared to those of benzodiazepine derivatives, such as diazepam and nitrazepam. REM sleep was significantly decreased only with 2 mg of Y-7131 and rebound elevation of REM sleep did not follow in recovery 1 and 2 nights. By using partial differential REM deprivation which was designed by us, there was also no rebound elevation of REM sleep noted in recovery 2 nights following 2 mg of Y-7131 medication. REM sleep was not suppressed with 15 mg of clotiazepam, 6 mg of diazepam and 10 mg of nitrazepam when compared to the baseline night. With regard to NREM sleep, stage 2 was significantly increased with 15 mg of clotiazepam and 10 mg of nitrazepam, but stage SWS was significantly decreased with 10 mg of nitrazepam. PMID:709

  7. Acute toxicity of selected crude and refined shale oil derived and petroleum-derived substances

    SciTech Connect

    Smith, L.H.; Haschek, W.M.; Witschi, H.

    1980-01-01

    General information was obtained on the toxicity of selected samples of crude Paraho shale oil and some of its derivatives, some crude petroleums, and 3 refined petroleum products. Five tests were used to determine the acute toxicity of these substances: acute lethality in mice following oral or intraperitoneal administration of a single dose; acute dermal toxicity of a single dose in rats; delayed-type allergic contact hypersensitivity in guinea pigs; primary eye irritation and primary skin irritation of a single dose in rabbits. Histopathologic changes induced in mice following intraperitoneal injection of a single large dose of crude shale oil and two of its hydrotreated derivatives were examined. Studies also have been initiated to examine the tumor inducing potential of selected samples. The test system used was the mouse lung adenoma bioassay. The present report describes our findings and shows that all compounds tested have very low or no acute toxic effects in laboratory animals.

  8. Bioactive diphenyl ether derivatives from a gorgonian-derived fungus Talaromyces sp.

    PubMed

    Chen, Min; Han, Lei; Shao, Chang-Lun; She, Zhi-Gang; Wang, Chang-Yun

    2015-03-01

    Three new diphenyl ether derivatives, talaromycins A-C (1-3, resp.), together with six known analogs, 4-9, were isolated from a gorgonian-derived fungus, Talaromyces sp. The structures of the new compounds were determined by analysis of extensive NMR spectroscopic data. All of the isolated metabolites, 1-9, were evaluated for their cytotoxic and antifouling activities. Compound 4 exhibited pronounced cytotoxicity against the tested human cell lines with the IC50 values ranging from 4.3 to 9.8??M. Compounds 3, 5, 8, and 9 showed potent antifouling activities against the larval settlement of the barnacle Balanus amphitrite with the EC50 values ranging from 2.2 to 4.8??g/ml. PMID:25766917

  9. Malignant transformation of cells derived from mouse prostate by epoxides and other derivatives of polycyclic hydrocarbons

    Microsoft Academic Search

    Hans Marquardt; Toshio Kuroki; Eliezer Huberman; James K. Selkirk; Charles Heidelberger; Philip L. Grover; Peter Sims

    1972-01-01

    SUMMARY K-region epoxides of benz(a) anthracene, dibenz(a,h) anthracene, and 3-methylcholanthrene have been found to be toxic and more active in producing malignant transformation of cells derived from mouse prostate than their respective parent hydrocarbons and K-region dihydrodiols and phenols. The data support the view that metabolism of these polycyclic hydrocarbons is a prerequisite for their biological activity. 7-Bromomethylbenz (a) anthracene,

  10. Territrem and Butyrolactone Derivatives from a Marine-Derived Fungus Aspergillus Terreus

    PubMed Central

    Nong, Xu-Hua; Wang, Yi-Fei; Zhang, Xiao-Yong; Zhou, Mu-Ping; Xu, Xin-Ya; Qi, Shu-Hua

    2014-01-01

    Seventeen lactones including eight territrem derivatives (1–8) and nine butyrolactone derivatives (9–17) were isolated from a marine-derived fungus Aspergillus terreus SCSGAF0162 under solid-state fermentation of rice. Compounds 1–3 and 9–10 were new, and their structures were elucidated by spectroscopic analysis. The acetylcholinesterase inhibitory activity and antiviral activity of compounds 1–17 were evaluated. Among them, compounds 1 and 2 showed strong inhibitory activity against acetylcholinesterase with IC50 values of 4.2 ± 0.6, 4.5 ± 0.6 nM, respectively. This is the first time it has been reported that 3, 6, 10, 12 had evident antiviral activity towards HSV-1 with IC50 values of 16.4 ± 0.6, 6.34 ± 0.4, 21.8 ± 0.8 and 28.9 ± 0.8 ?g·mL?1, respectively. Antifouling bioassay tests showed that compounds 1, 11, 12, 15 had potent antifouling activity with EC50 values of 12.9 ± 0.5, 22.1 ± 0.8, 7.4 ± 0.6, 16.1 ± 0.6 ?g·mL?1 toward barnacle Balanus amphitrite larvae, respectively. PMID:25522319

  11. Cognitive effects of cell-derived and synthetically-derived A? oligomers

    PubMed Central

    Reed, Miranda N.; Hofmeister, Jacki J.; Jungbauer, Lisa; Welzel, Alfred T.; Yu, Chunjiang; Sherman, Mathew A.; Lesné, Sylvain; LaDu, Mary Jo; Walsh, Dominic M.; Ashe, Karen H.; Cleary, James P.

    2010-01-01

    Soluble forms of amyloid-? peptide (A?) are a molecular focus in Alzheimer's disease research. Soluble A? dimers (? 8 kDa), timers (? 12 kDa), tetramers (? 16 kDa) and A?*56 (? 56 kDa) have shown biological activity. These A? molecules have been derived from diverse sources, including chemical synthesis, transfected cells, and mouse and human brain, leading to uncertainty about toxicity and potency. Herein, synthetic A? peptide-derived oligomers, cell- and brain-derived low-n oligomers, and A?*56, were injected intracerebroventricularly (icv) into rats assayed under the Alternating Lever Cyclic Ratio (ALCR) cognitive assay. Cognitive deficits were detected at 1.3?M of synthetic A? oligomers and at low nanomolar concentrations of cell-secreted A? oligomers. Trimers, from transgenic mouse brain (Tg2576), did not cause cognitive impairment at any dose tested, whereas A?*56 induced concentration-dependent cognitive impairment at 0.9?M and 1.3?M. Thus, while multiple forms of A? have cognition impairing activity, there are significant differences in effective concentration and potency. PMID:20031278

  12. Environmental applications of chitosan and its derivatives.

    PubMed

    Yong, Soon Kong; Shrivastava, Manoj; Srivastava, Prashant; Kunhikrishnan, Anitha; Bolan, Nanthi

    2015-01-01

    Chitosan originates from the seafood processing industry and is one of the most abundant of bio-waste materials. Chitosan is a by-product of the alkaline deacetylation process of chitin. Chemically, chitosan is a polysaccharide that is soluble in acidic solution and precipitates at higher pHs. It has great potential for certain environmental applications, such as remediation of organic and inorganic contaminants, including toxic metals and dyes in soil, sediment and water, and development of contaminant sensors. Traditionally, seafood waste has been the primary source of chitin. More recently, alternative sources have emerged such as fungal mycelium, mushroom and krill wastes, and these new sources of chitin and chitosan may overcome seasonal supply limitations that have existed. The production of chitosan from the above-mentioned waste streams not only reduces waste volume, but alleviates pressure on landfills to which the waste would otherwise go. Chitosan production involves four major steps, viz., deproteination, demineralization, bleaching and deacetylation. These four processes require excessive usage of strong alkali at different stages, and drives chitosan's production cost up, potentially making the application of high-grade chitosan for commercial remediation untenable. Alternate chitosan processing techniques, such as microbial or enzymatic processes, may become more cost-effective due to lower energy consumption and waste generation. Chitosan has proved to be versatile for so many environmental applications, because it possesses certain key functional groups, including - OH and -NH2 . However, the efficacy of chitosan is diminished at low pH because of its increased solubility and instability. These deficiencies can be overcome by modifying chitosan's structure via crosslinking. Such modification not only enhances the structural stability of chitosan under low pH conditions, but also improves its physicochemical characteristics, such as porosity, hydraulic conductivity, permeability, surface area and sorption capacity. Crosslinked chitosan is an excellent sorbent for trace metals especially because of the high flexibility of its structural stability. Sorption of trace metals by chitosan is selective and independent of the size and hardness of metal ions, or the physical form of chitosan (e.g., film, powder and solution). Both -OH and -NH2 groups in chitosan provide vital binding sites for complexing metal cations. At low pH, -NH3 + groups attract and coagulate negatively charged contaminants such as metal oxyanions, humic acids and dye molecules. Grafting certain functional molecules into the chitin structure improves sorption capacity and selectivity for remediating specific metal ions. For example, introducing sulfur and nitrogen donor ligands to chitosan alters the sorption preference for metals. Low molecular weight chitosan derivatives have been used to remediate metal contaminated soil and sediments. They have also been applied in permeable reactive barriers to remediate metals in soil and groundwater. Both chitosan and modified chitosan have been used to phytoremediate metals; however, the mechanisms by which they assist in mobilizing metals are not yet well understood. In addition, microbes have been used in combination with chitosan to remediate metals (e.g., Cu and Zn) in contaminated soils. Chitosan has also been used to remediate organic contaminants, such as oil-based wastewater, dyes, tannins, humic acids, phenols, bisphenoi-A, p-benzoquinone, organo-phosphorus insecticides, among others. Chitosan has also been utilized to develop optical and electrochemical sensors for in-situ detection of trace contaminants. In sensor technology, naturally-derived chitosan is used primarily as an immobilizing agent that results from its enzyme compatibility, and stabilizing effect on nanoparticles. Contaminant-sensing agents, such as enzymes, microbes and nanoparticles, have been homogeneously immobilized in chitosan gels by using coagulating (e.g., alginate, phosphate) or crosslinking agents (e.g., GA, ECH).

  13. Tachometers Derived From a Brushless DC Motor

    NASA Technical Reports Server (NTRS)

    Howard, David E.; Smith, Dennis A.

    2007-01-01

    The upper part of the figure illustrates the major functional blocks of a direction-sensitive analog tachometer circuit based on the use of an unexcited two-phase brushless dc motor as a rotation transducer. The primary advantages of this circuit over many older tachometer circuits include the following: Its output inherently varies linearly with the rate of rotation of the shaft. Unlike some tachometer circuits that rely on differentiation of voltages with respect to time, this circuit relies on integration, which results in signals that are less noisy. There is no need for an additional shaft-angle sensor, nor is there any need to supply electrical excitation to a shaft-angle sensor. There is no need for mechanical brushes (which tend to act as sources of electrical noise). The underlying concept and electrical design are relatively simple. This circuit processes the back-electromagnetic force (back-emf) outputs of the two motor phases into a voltage directly proportional to the instantaneous rate (sign magnitude) of rotation of the shaft. The processing in this circuit effects a straightforward combination of mathematical operations leading to a final operation based on the well-known trigonometric identity (sin x)2 + (cos x)2 = 1 for any value of x. The principle of operation of this circuit is closely related to that of the tachometer circuit described in Tachometer Derived From Brushless Shaft-Angle Resolver (MFS-28845), NASA Tech Briefs, Vol. 19, No. 3 (March 1995), page 39. However, the present circuit is simpler in some respects because there is no need for sinusoidal excitation of shaftangle- resolver windings.

  14. Gravity derived Moho for South America

    NASA Astrophysics Data System (ADS)

    van der Meijde, M.; Julià, J.; Assumpção, M.

    2013-12-01

    Crustal structure in South America is one of the least understood among the Earth's continental areas. Variations in crustal thickness are still poorly constrained over large portions of the continent because of scarce or unevenly distributed crustal thickness estimates throughout South America. To address this scarce and inhomogeneous data cover we explore the possibility to derive crustal thickness from satellite gravity data. In this study, we utilize the combined gravity model EIGEN-6C, which is composed of GOCE and other gravity data. The Gravity field and steady-state Ocean Circulation Explorer (GOCE) satellite has a much more uniform spatial resolution than any land-based gravity or seismic survey in South America. The gravity data inversion is for a simple two-layer model with fixed density contrast over the interface, the Moho. The method is not relying on point constraint data and assumes that all of the signal is related to topography of the Moho. Model quality can therefore be assessed by a comparison with point observations on crustal thickness. We show that for the stable part of the continent 90% of our estimates are similar, within error bounds, to seismic observations. Variations occur in active orogenic zones or regions with suspected non-standard Moho density contrasts. A comparison with seismological models shows a high correlation with the most recent model. Especially in areas where continental and global models of crustal structure have limitations in terms of wave paths or point constraints the gravity based model provides a unique continuity of crustal structure providing new insights on structure and tectonics and increase our understanding of the Earth's structure underneath South America.

  15. Synthesis and electronic aspects of tetrahydrobenzothienopyrimidine derivatives

    NASA Astrophysics Data System (ADS)

    Gajda, Katarzyna; Astakhina, Valeriia; Ejsmont, Krzysztof; Kolomeitsev, Dmytro; Kovalenko, Sergiy; Zarychta, Bartosz

    2015-03-01

    The chemistry of thiophenes, pyrimidines, triazolopyrimidines and benzothiophenes has drawn much attention because of their biological activities. Their interesting properties are connected with their complex ?-electron delocalisation effects. Herein the synthesis, crystal and molecular structures at 100 K and DFT calculated structures of three tetrahydrobenzothienopyrimidine derivatives are reported i.e. 4-hydrazino-5,6,7,8-tetrahydro[1]benzothieno[2,3-d]pyrimidine which was a substrate for 2-phenyl-8,9,10,11-tetrahydro[1]benzothieno[3,2-e][1,2,4]triazolo[1,5-c]pyrimidine and 3-methyl-9,10,11,12-tetrahydro-2H-[1]benzothieno[2?,3?:4,5]pyrimido[1,6-b][1,2,4]triazin-2-one. Moreover the influence of the substituents, polycyclic structure and crystal packing and on the aromaticity of the fused heterocyclic rings have been also discussed. The 4-hydrazino-5,6,7,8-tetrahydro[1]benzothieno[2,3-d]pyrimidine is a promising substrate for a number of different reactions and discovering novel biologically active heterocycles. All three molecules are planar except of the tetrahydrobenzene part, which shows normal conformation. In crystals the molecules are connected to each other by C-H⋯N, N-H⋯N, C-H⋯S and S⋯? contacts. The geometry of common core in all structures is similar and typical for this class of compounds. The aromaticity of the fused heteroaromatic systems has been investigated by means of the HOMA indices. The discrepancy between values of HOMA for isolated monocyclic compounds and studied molecules from crystal structure shows destabilization of aromaticity when the rings are fused in a larger heterocyclic systems. The thiophene part of the molecule is far more sensitive on the influence of both mesomeric effects in polycyclic system and molecular environment in solid-state than pyrimidine ring. The presence of intermolecular interactions was confirmed by Hirshfeld area analysis.

  16. Derivation of physically motivated wind speed scales

    NASA Astrophysics Data System (ADS)

    Dotzek, Nikolai

    A class of new wind speed scales is proposed in which the relevant scaling factors are derived from physical quantities like mass flux density, energy density (pressure), or energy flux density. Hence, they are called Energy- or E-scales, and can be applied to wind speeds of any intensity. It is shown that the Mach scale is a special case of an E-scale. Aside from its foundation in physical quantities which allow for a calibration of the scales, the E-scale concept can help to overcome the present plethora of scales for winds in the range from gale to hurricane intensity. A procedure to convert existing data based on the Fujita-scale or other scales (Saffir-Simpson, TORRO, Beaufort) to their corresponding E-scales is outlined. Even for the large US tornado record, the workload of conversion in case of an adoption of the E-scale would in principle remain manageable (if the necessary metadata to do so were available), as primarily the F5 events would have to be re-rated. Compared to damage scales like the "Enhanced Fujita" or EF-scale concept recently implemented in the USA, the E-scales are based on first principles. They can consistently be applied all over the world for the purpose of climatological homogeneity. To account for international variations in building characteristics, one should not adapt wind speed scale thresholds to certain national building characteristics. Instead, one worldwide applicable wind speed scale based on physical principles should rather be complemented by nationally-adapted damage descriptions. The E-scale concept can provide the basis for such a standardised wind speed scale.

  17. Local detailed balance: a microscopic derivation

    NASA Astrophysics Data System (ADS)

    Bauer, M.; Cornu, F.

    2015-01-01

    Thermal contact is the archetype of non-equilibrium processes driven by constant non-equilibrium constraints when the latter are enforced by reservoirs exchanging conserved microscopic quantities. At a mesoscopic scale only the energies of the macroscopic bodies are accessible together with the configurations of the contact system. We consider a class of models where the contact system, as well as macroscopic bodies, have a finite number of possible configurations. The global system, with only discrete degrees of freedom, has no microscopic Hamiltonian dynamics, but it is shown that, if the microscopic dynamics is assumed to be deterministic and ergodic and to conserve energy according to some specific pattern, and if the mesoscopic evolution of the global system is approximated by a Markov process as closely as possible, then the mesoscopic transition rates obey three constraints. In the limit where macroscopic bodies can be considered as reservoirs at thermodynamic equilibrium (but with different intensive parameters), the mesoscopic transition rates turn into transition rates for the contact system and the third constraint becomes local detailed balance; the latter is generically expressed in terms of the microscopic exchange entropy variation, namely the opposite of the variation of the thermodynamic entropy of the reservoir involved in a given microscopic jump of the contact system configuration. For a finite-time evolution after contact has been switched on, we derive a fluctuation relation for the joint probability of the heat amounts received from the various reservoirs. The generalization to systems exchanging energy, volume and matter with several reservoirs, with a possible conservative external force acting on the contact system, is given explicitly.

  18. Routine development of objectively derived search strategies

    PubMed Central

    2012-01-01

    Background Over the past few years, information retrieval has become more and more professionalized, and information specialists are considered full members of a research team conducting systematic reviews. Research groups preparing systematic reviews and clinical practice guidelines have been the driving force in the development of search strategies, but open questions remain regarding the transparency of the development process and the available resources. An empirically guided approach to the development of a search strategy provides a way to increase transparency and efficiency. Methods Our aim in this paper is to describe the empirically guided development process for search strategies as applied by the German Institute for Quality and Efficiency in Health Care (Institut für Qualität und Wirtschaftlichkeit im Gesundheitswesen, or "IQWiG"). This strategy consists of the following steps: generation of a test set, as well as the development, validation and standardized documentation of the search strategy. Results We illustrate our approach by means of an example, that is, a search for literature on brachytherapy in patients with prostate cancer. For this purpose, a test set was generated, including a total of 38 references from 3 systematic reviews. The development set for the generation of the strategy included 25 references. After application of textual analytic procedures, a strategy was developed that included all references in the development set. To test the search strategy on an independent set of references, the remaining 13 references in the test set (the validation set) were used. The validation set was also completely identified. Discussion Our conclusion is that an objectively derived approach similar to that used in search filter development is a feasible way to develop and validate reliable search strategies. Besides creating high-quality strategies, the widespread application of this approach will result in a substantial increase in the transparency of the development process of search strategies. PMID:22587829

  19. Oxidative stress induced by a dihydropyrazine derivative.

    PubMed

    Takechi, Shinji; Nakahara, Kazuhide; Adachi, Masaru; Yamaguchi, Tadatoshi

    2009-02-01

    The Maillard reaction contributes to the complications of diabetes and normal aging. Dihydropyrazines (DHPs), which are produced during the Maillard reaction, generate radicals and possess DNA strand-cleaving activities in vitro. In the present study, we evaluated the genotoxic and cytotoxic potentials of a DHP derivative, cyclohexyl-DHP, which is obtained as a mixture of two isomers, 2,3,5,6,7,8-hexahydroquinoxaline (endo-type) and 1,2,3,5,6,7-hexahydroquinoxaline (exo-type), fused with a cyclohexyl ring. Cyclohexyl-DHP caused DNA strand breaks in plasmid pUC18, especially in the presence of Cu(2+). By using Escherichia coli mutant strains, we observed that cyclohexyl-DHP exposure strongly reduced the survival rate of a cytosolic sodium dodecyl sulfate (SOD)-deficient strain (sodA sodB), significantly reduced the survival rates of DNA repair-deficient strains (recA and uvrB) and mildly reduced the survival rate of a catalase-deficient strain (katE katG) compared with the survival rate of the wild-type strain. Addition of Cu(2+) enhanced the cell killing ability of cyclohexyl-DHP. The frequency of mutations induced by cyclohexyl-DHP increased dose-dependently in the sodA sodB strain. Assays with the highly water-soluble tetrazolium salt WST-1 revealed that cyclohexyl-DHP strongly generated superoxide anions. Moreover, cyclohexyl-DHP elevated the protein carbonyl levels in E. coli. These findings indicate that cyclohexyl-DHP could potentially generate superoxide anions, and cause not only breakage of chromosomal DNA leading to mutagenic lesions but also induce damage to cellular proteins. PMID:19182373

  20. Derivative encoding for parallel magnetic resonance imaging a

    PubMed Central

    Shen, Jun

    2011-01-01

    Purpose: To introduce a linear shift-invariant relationship between the partial derivatives of k space signals acquired using multichannel receive coils and to demonstrate that k space derivatives can be used for image unwrapping.Methods: Fourier transform of k space derivatives contains information on the spatial origins of aliased pixels; therefore, images can be reconstructed by k space derivatives. Fully sampled phantom and brain images acquired at 3 T using a standard eight channel receive coil were used to validate the k space derivatives theorem by unwrapping aliased images.Results: Derivative encoding leads to new methods for parallel imaging reconstruction in both k space and image domains. Noise amplification in sensitivity encoding image reconstruction, which is considered to produce the optimal SNR, can be further reduced using k space derivative encoding without making any assumptions on the characteristics of the images to be reconstructed.Conclusions: This work demonstrated that the partial derivative of the k space signal acquired from one coil with respect to one direction can be expressed as a sum of partial derivatives of signals from multiple coils with respect to the perpendicular k space direction(s). This relationship between the partial derivatives of k space signals is linear and shift-invariant in the Cartesian coordinate system. PMID:21992376

  1. Transformational derivation of programs using the Focus system

    NASA Technical Reports Server (NTRS)

    Reddy, Uday S.

    1988-01-01

    A program derivation support system called Focus is being constructed. It will formally derive programs using the paradigm of program transformation. The following issues are discussed: (1) the integration of validation and program derivation activities in the Focus system; (2) its tree-based user interface; (3) the control of search spaces in program derivation; and (4) the structure and organization of program derivation records. The inference procedures of the system are based on the integration of functional and logic programming principles. This brings about a synthesis of paradigms that were heretofore considered far apart, such as logical and executable specifications and constructive and transformational approaches to program derivation. A great emphasis has been placed, in the design of Focus, on achieving small search spaces during program derivation. The program manipulation operations such as expansion, simplification and rewriting were designed with this objective. The role of operations that are expensive in search spaces, such as folding, has been reduced. Program derivations are documented in Focus in a way that the high level descriptions of derivations are expressed only using program level information. All the meta-level information, together with dependencies between derivations of program components, is automatically recorded by the system at a lower level of description for its own use in replay.

  2. Rigorous derivation of electromagnetic self-force

    SciTech Connect

    Gralla, Samuel E.; Harte, Abraham I.; Wald, Robert M. [Enrico Fermi Institute and Department of Physics, University of Chicago, 5640 South Ellis Avenue, Chicago, Illinois 60637 (United States)

    2009-07-15

    During the past century, there has been considerable discussion and analysis of the motion of a point charge in an external electromagnetic field in special relativity, taking into account 'self-force' effects due to the particle's own electromagnetic field. We analyze the issue of 'particle motion' in classical electromagnetism in a rigorous and systematic way by considering a one-parameter family of solutions to the coupled Maxwell and matter equations corresponding to having a body whose charge-current density J{sup a}({lambda}) and stress-energy tensor T{sub ab}({lambda}) scale to zero size in an asymptotically self-similar manner about a worldline {gamma} as {lambda}{yields}0. In this limit, the charge, q, and total mass, m, of the body go to zero, and q/m goes to a well-defined limit. The Maxwell field F{sub ab}({lambda}) is assumed to be the retarded solution associated with J{sup a}({lambda}) plus a homogeneous solution (the 'external field') that varies smoothly with {lambda}. We prove that the worldline {gamma} must be a solution to the Lorentz force equations of motion in the external field F{sub ab}({lambda}=0). We then obtain self-force, dipole forces, and spin force as first-order perturbative corrections to the center-of-mass motion of the body. We believe that this is the first rigorous derivation of the complete first-order correction to Lorentz force motion. We also address the issue of obtaining a self-consistent perturbative equation of motion associated with our perturbative result, and argue that the self-force equations of motion that have previously been written down in conjunction with the 'reduction of order' procedure should provide accurate equations of motion for a sufficiently small charged body with negligible dipole moments and spin. (There is no corresponding justification for the non-reduced-order equations.) We restrict consideration in this paper to classical electrodynamics in flat spacetime, but there should be no difficulty in extending our results to the motion of a charged body in an arbitrary globally hyperbolic curved spacetime.

  3. Asteroid Thermal Properties Derived from Meteorite Data

    NASA Astrophysics Data System (ADS)

    Consolmagno, Guy; Macke, R. J.; Britt, D. T.

    2013-10-01

    The thermal inertia of an asteroid’s surface determines its response to the various Yarkovsky effects, while its internal thermal diffusivity controls its thermal evolution. Each quantity is a function of the material’s thermal conductivity, heat capacity, and density. Over the past ten years we have conducted a detailed survey measuring density in meteorites and are currently in the early stages of similar surveys for thermal conductivity and heat capacity. While various meteorite types differ in small but significant ways, for asteroid studies typical average values of these quantities can be estimated to within about 10%. (Metallic asteroids would have significantly different behavior.) The most important variable controlling density and thermal conductivity is porosity, P, while heat capacity is a strong function of temperature, T. Most stony meteorite densities are within 10% of 3500*(1-P) (SI units); basaltic and volatile rich meteorites are 10% to 30% less dense. Thermal conductivity in the temperature range of interest in the asteroid belt is nearly constant with temperature but varies strongly with porosity; assuming the trend seen for meteorite porosities up to 25% can be extrapolated to higher porosities, with zero conductivity at 100% porosity, a typical conductivity (for porosities greater than 2%) can be approximated by k = 0.11/P - 0.11 (SI units). Heat capacity ranges from under 250 J/kgK at 100 K to over 600 J/kgK at 250 K; over these temperatures this variation can be fitted by a quadratic in T. From these formulae we can derive representative values for thermal inertia and diffusivity and see how they vary as a function of porosity and temperature values appropriate for most asteroids. The greatest variation is with porosity. Thermal diffusivity drops by nearly two orders of magnitude from 0 to 20% porosity, more slowly at higher porosities. Thermal inertia (at 200K) varies from 3000 (SI units) near zero porosity down to 3 as porosity approaches 100%; 10% porosity has a thermal inertia near 1000 while 90% porous is about 60. Literature asteroid thermal inertias range from as high as 1000 to below 30; asteroid thermal inertias below 100 demand an extremely porous (>80%) surface.

  4. Derivation of Formulations 1 and 1A of Farassat

    NASA Technical Reports Server (NTRS)

    Farassat, F.

    2007-01-01

    Formulations 1 and 1A are the solutions of the Ffowcs Williams-Hawkings (FW-H) equation with surface sources only when the surface moves at subsonic speed. Both formulations have been successfully used for helicopter rotor and propeller noise prediction for many years although we now recommend using Formulation 1A for this purpose. Formulation 1 has an observer time derivative that is taken numerically, and thus, increasing execution time on a computer and reducing the accuracy of the results. After some discussion of the Green's function of the wave equation, we derive Formulation 1 which is the basis of deriving Formulation 1A. We will then show how to take this observer time derivative analytically to get Formulation 1A. We give here the most detailed derivation of these formulations. Once you see the whole derivation, you will ask yourself why you did not do it yourself!

  5. Synthesis and biological evaluation of caracasine acid derivatives.

    PubMed

    Chávez, Katiuska; Compagnone, Reinaldo S; Álvarez, Annamil; Figarella, Katherine; Galindo-Castro, Iván; Marsiccobetre, Sabrina; Triviño, Jennifer; Arocha, Irina; Taddei, Antonieta; Orsini, Giovannina; Tillett, Stephen; Suárez, Alírica I

    2015-07-01

    A series of caracasine acid (1) derivatives were synthesized and evaluated for their in vitro cytotoxicity on human cancer-derived cell lines MCF-7 and PC-3, as well as for other activities such as antibacterial, antileishmanial and antitrypanosomal activity. Compound 1 was more effective than any of its derivatives against tested human cancer cell lines. PC-3 cells were more sensitive than MCF-7 to all compounds, particularly the methyl ester (2), the amide (9) and the epoxide (10). The evaluation of antiparasitic activity revealed that ester derivatives (2-8) and the amide derivative (9) were the most effective antileishmanial and antitrypanosomal compounds, even though their effect on Trypanosoma cruzi was modest. Finally, compound 1 and the derivatives evidenced a broad spectrum of antibacterial activity, as assayed against Gram-positive and Gram-negative bacteria. PMID:25891984

  6. Hadamard-like derivatives in Preisach modeling and control

    NASA Astrophysics Data System (ADS)

    Belbas, S. A.; Mayergoyz, I. D.

    2006-02-01

    We define a concept of derivatives of the relative boundary of the active set, on the Preisach plane, with respect to the time variable, under a time-varying input of the piecewise monotone type. These derivatives are related to the set-valued derivatives previously introduced by these authors. This concept of derivatives, which is akin to the derivatives introduced by Hadamard in the derivation of his formula on variation of a Green's function under perturbations of the domain for a boundary-value problem, allows the representation of the Preisach evolution in terms of a generalized variant of a differential equation, which in turn can be used as a basis for dynamic programming for optimal control and game theory problems for systems with hysteresis.

  7. Novel deoxycholic acid alkylamide-phenylurea-derived organogelators

    Microsoft Academic Search

    Juha Koivukorpi; Erkki Kolehmainen

    2010-01-01

    Three monomeric and three dimeric deoxycholic acid (DCA) alkylamido-phenylurea derivatives are designed based on known gelators and are synthesized and characterized by 1H and 13C NMR spectroscopy, ESI-TOF mass spectrometry, and elemental analyses. Among them, a monomeric derivative forms supramolecular gels in CHCl3 and chlorobenzene, whereas a dimeric derivative gels THF and higher 1-alkanols containing 7–10 carbons. The morphologies of

  8. Synthesis and antimultidrug resistance evaluation of icariin and its derivatives

    Microsoft Academic Search

    Dong-Fang Liu; Yan-Ping Li; Tian-Miao Ou; Shi-Liang Huang; Lian-Quan Gu; Min Huang; Zhi-Shu Huang

    2009-01-01

    A series of icariin derivatives were synthesized. Their multidrug resistance (MDR) reversal activities were evaluated by MTT assay and the results indicated that the derivatives were the potent modulators of MDR. It was showed that the derivatives significantly increased the intracellular accumulation of ADR in MCF-7\\/ADR cells compared with drug sensitive MCF-7 cells. The results of bi-directional assay and reverse

  9. Massive Gravity from Higher Derivative Gravity with Boundary Conditions

    E-print Network

    Minjoon Park; Lorenzo Sorbo

    2012-10-29

    With an appropriate choice of parameters, a higher derivative theory of gravity can describe a normal massive sector and a ghost massless sector. We show that, when defined on an asymptotically de Sitter spacetime with Dirichlet boundary conditions, such a higher derivative gravity can provide a framework for a unitary theory of massive gravity in four spacetime dimensions. The resulting theory is free not only of higher derivative ghosts but also of the Boulware-Deser mode.

  10. Napyradiomycin Derivatives, Produced by a Marine-Derived Actinomycete, Illustrate Cytotoxicity by Induction of Apoptosis

    PubMed Central

    Farnaes, Lauge; Coufal, Nicole G.; Kauffman, Christopher A.; Rheingold, Arnold L.; DiPasquale, Antonio G.; Jensen, Paul R.; Fenical, William

    2014-01-01

    The microbial production, isolation and structure elucidation of four new napyradiomycin congeners (1–4) is reported. The structures of these compounds, which are new additions to the marine-derived meroterpenoids, were defined by comprehensive spectroscopic analysis and by X-ray crystallography. Using fluorescence-activated cell sorting (FACS) analysis, napyradiomycins 1–4 were observed to induce apoptosis in the colon adenocarcinoma cell line, HCT-116, indicating the possibility of a specific biochemical target for this class of cytotoxins. PMID:24328269

  11. Derived equivalences of triangles, rectangles and lines On Derived Equivalences of Triangles,

    E-print Network

    Ladkani, Sefi

    @@@@@@@ · · bb~~~~~~~ · GG · GG · GG · GG · GG · GG · GG · GG · GG · A1, A2, A3, D4, D5, E6, E7, E8 2 #12;Derived, - An ­ the quiver ·1 x GG ·2 x GG ·3 x GG . . . x GG ·n The path algebra k - An is the incidence algebra) is the canonical algebra of weight type (2, p, q) [Lenzing - de la Pe~na 2008]. · GG · GG · GG · GG · GG · GG · GG

  12. Chalcone and dihydrochalcone derivatives from the orchid Lusia volucris

    Microsoft Academic Search

    P. L. Majumder; S. Lahiri; N. Mukhoti

    1995-01-01

    A new dihydrochalcone derivative, lusianin, two other known chalcones and a phenanthrene derivative were isolated from the orchid Lusia volucris. The two chalcones and the phenanthrene derivative were characterized as 2-propene-1-one-1-(2?,4?-dihydroxy-3?-methoxyphenyl)-3-(4?-methoxyphenyl) and 2-propene-1-one-1-(2?-hydroxy-4?-methoxyphenyl)-3-(4?-methoxyphenyl) and 6-hydroxy-2,4,7-trimethoxyphenanthrene(batatasin-I), respectively, by independent spectral analysis of the compounds and their acetyl derivatives. The structure of lusianin was established as 1-propanone-1-(2?,4?-dihydroxy-3?-methoxyphenyl)-3-(4?-methoxyphenyl) from spectral and chemical evidence.

  13. Renormalization and unitarity in higher derivative and nonlocal gravity theories

    NASA Astrophysics Data System (ADS)

    Tomboulis, E. T.

    2015-01-01

    We review and discuss higher derivative and nonlocal theories of quantum gravity focusing on their UV and unitarity properties. We first consider the general fourth-order gravitational action, then actions containing derivatives up to any given fixed order, and discuss their UV divergences, fixed points and concomitant unitarity issues. This leads to a more general discussion of "asymptotic safety" and unitarity, which motivates the introduction of nonlocal theories containing derivatives to all orders arising from the expansion of entire functions. For such theories good UV behavior is visible at any finite truncation, but unitarity emerges only when derivatives to all orders are included.

  14. Single Molecule Conductance of Oligothiophene Derivatives

    NASA Astrophysics Data System (ADS)

    Dell, Emma J.

    This thesis studies the electronic properties of small organic molecules based on the thiophene motif. If we are to build next-generation devices, advanced materials must be designed which possess requisite electronic functionality. Molecules present attractive candidates for these ad- vanced materials since nanoscale devices are particularly sought after. However, selecting a molecule that is suited to a certain electronic function remains a challenge, and characterization of electronic behavior is therefore critical. Single molecule conductance measurements are a powerful tool to determine properties on the nanoscale and, as such, can be used to investigate novel building blocks that may fulfill the design requirements of next-generation devices. Combining these conductance results with strategic chemical synthesis allows for the development of new families of molecules that show attractive properties for future electronic devices. Since thiophene rings are the fruitflies of organic semiconductors on the bulk scale, they present an intriguing starting point for building functional materials on the nanoscale, and therefore form the structural basis of all molecules studied herein. First, the single-molecule conductance of a family of bithiophene derivatives was measured. A broad distribution in the single-molecule conductance of bithiophene was found compared with that of a biphenyl. This increased breadth in the conductance distribution was shown to be explained by the difference in 5-fold symmetry of thiophene rings as compared to the 6-fold symmetry of benzene rings. The reduced symmetry of thiophene rings results in a restriction on the torsion angle space available to these molecules when bound between two metal electrodes in a junction, causing each molecular junction to sample a different set of conformers in the conductance measurements. By contrast, the rotations of biphenyl are essentially unimpeded by junction binding, allowing each molecular junction to sample similar conformers. This work demonstrates that the conductance of bithiophene displays a strong dependence on the conformational fluctuations accessible within a given junction configuration, and that the symmetry of such small molecules can significantly influence their conductance behavior. Next, the single-molecule conductance of a family of oligothiophenes comprising one to six thiophene units was measured. An anomalous behavior was found: the peak of the conductance histogram distribution did not follow a clear exponential decay with increasing number of thiophene units in the chain. The electronic properties of the materials were characterized by optical spectroscopy and electrochemistry to gain an understanding of the factors affecting the conductance of these molecules. Different conformers in the junction were postulated to be a contributing factor to the anomalous trend in the observed conductance as a function of molecule length. Then, the electronic properties of the thiophene-1,1-dioxide unit were investigated. These motifs have become synthetically accessible in the last decade, due to Rozen's unprecedentedly potent oxidizing reagent - HOF?CH 3CN - which has been shown to be powerful yet selective enough to oxidize thiophenes in various environments. The resulting thiophene-1,1-dioxides show great promise for electronic devices. The oxidation chemistry of thiophenes was expanded and tuning of the frontier energy levels was demonstrated through combining electron poor and electron rich units. Finally, charge carriers in single-molecule junctions were shown to be tunable within a family of molecules containing these thiophene-1,1-dioxide (TDO) building blocks. Oligomers of TDO were designed in order to increase electron affinity, maintain delocalized frontier orbitals, while significantly decreasing the transport gap. Through thermopower measurements, the dominant charge carriers were shown to change from holes to electrons as the number of TDO units was increased. This resulted in a unique system in which the charge carrier depends on ba

  15. Production of Chemical Derivatives from Renewables

    SciTech Connect

    Davison, Brian; Nghiem, John; Donnelly, Mark; Tsai, Shih-Perng; Frye, John; Landucci, Ron; Griffin, Michael

    1996-06-01

    The purpose of this Cooperative Research and Development Agreement (CRADA) between Lockheed Martin Energy Research Corp., (LMER), Argonne National Laboratory (ANL), National Renewable Energy Laboratory (NREL), and Battelle Memorial Institute, operator of Pacific Northwest National Laboratory (PNNL), (collectively referred to as the 'Contractor'), and Applied Carbochemicals, Inc. (Participant) was to scale-up from bench results an economically promising and competitive process for the production of chemical derivatives from biologically produced succinic acid. The products that were under consideration for production from the succinic acid platform included 1,4-butanediol, {gamma}y-butyrolactone, 2-pyrrolidinone and N-methyl pyrrolidinone. Preliminary economic analyses indicated that this platform was competitive with the most recent petrochemical routes. The Contractors and participant are hereinafter jointly referred to as the 'Parties.' Research to date in succinic acid fermentation, separation and genetic engineering resulted in a potentially economical process based on the use of an Escherichia coli strain AFP111 with suitable characteristics for the production of succinic acid from glucose. Economic analysis has shown that higher value commodity chemicals can be economically produced from succinic acid based on preliminary laboratory findings and predicted catalytic parameters. At the time, the current need was to provide the necessary laboratory follow-up information to properly optimize, design and operate a pilot scale process. The purpose of the pilot work was to validate the integrated process, assure 'robustness' of the process, define operating conditions, and provide samples for potential customer evaluation. The data from the pilot scale process was used in design and development of a full scale production facility. A new strain, AFP111 (patented), discovered at ANL was tested and developed for process use at the Oak Ridge National Laboratory (ORNL) and ANL. The operability and product formation are attractive for this strain and effort was being directed at process development and optimization. Key to the transition from the fermentative production unit operation to the chemical catalysis is the 'clean-up' of fermentation broth, succinic acid formation from the salt, and succinic acid concentration. These steps are accomplished by a two-stage membrane ED separation process developed at AWL. Although the current process is well developed, possible modifications and optimization may be called for as development work continues in both the fermentation and catalysis areas. Research to date performed at PNNL has demonstrated that succinic acid can be converted to value added chemicals such as 1,4-butanediol, {gamma}-butyrolactone, N-methyl pyrrolidinone, and 2 pyrrolidinone with high conversion and selectivities. Continued research will be performed in catalyst development and reaction condition optimization to move this work from the bench scale to the pilot scale. All development of the process was guided by the NREL technoeconomic model. The model showed that direct aqueous phase catalysis of succinic acid to 1,4-butanediol, {gamma}-butyrolactone, and N-methyl pyrrolidinone provided significant economical advantages in the market, the margin, and the return on capital investment over existing petrochemical processes for production of these compounds. The model also provided the baseline for evaluating current laboratory research. As data from the bench and pilot work were made available the model was modified and appropriate sensitivities ran to determine impact of the process changes and optimization. The report will present the planned CRADA tasks followed by the results. The results section has an overall project summary follwed by more detailed reports from the participants. This is a nonproprietary report; additional proprietary information may be made available subject to acceptance of the appropriate proprietary information agreements.

  16. Intra- and intermolecular hydrogen bonding in acetylacetone and benzoylacetone derived enaminone derivatives

    NASA Astrophysics Data System (ADS)

    Lazi?, Vedrana; Jurkovi?, Mihaela; Jedna?ak, Tomislav; Hrenar, Tomica; Vukovi?, Jelena Parlov; Novak, Predrag

    2015-01-01

    The structure and hydrogen bonding in solution of acetylacetone and benzoylacetone derived enaminone derivatives, 1a-1d and 2a-2d, have been studied by a combination of experimental (NMR and UV spectroscopies) and theoretical (PM6 and DFT) methods. It has been shown that all studied compounds predominantly existed in the localised keto-amine tautomeric form in solution as found also in the solid state. Significant line-broadening and down-field chemical shifts of NH and OH protons have strongly indicated that both groups formed hydrogen bonds, which has further been supported by quantum chemical calculations. Temperature and concentration dependent NMR measurements have pointed towards the fact that NH protons are engaged in strong intramolecular hydrogen bonds of the NH⋯Odbnd C type in both solvents. On the other hand, OH protons are involved in weaker intermolecular hydrogen bonding with solvent molecules in DMSO, while in chloroform intermolecular interactions between two molecules dominate. The results presented in this paper can be used for better understanding and further exploiting properties these ligands possess, especially their bioactivity.

  17. Bioactive Phenylalanine Derivatives and Cytochalasins from the Soft Coral-Derived Fungus, Aspergillus elegans

    PubMed Central

    Zheng, Cai-Juan; Shao, Chang-Lun; Wu, Lu-Yong; Chen, Min; Wang, Kai-Ling; Zhao, Dong-Lin; Sun, Xue-Ping; Chen, Guang-Ying; Wang, Chang-Yun

    2013-01-01

    One new phenylalanine derivative 4?-OMe-asperphenamate (1), along with one known phenylalanine derivative (2) and two new cytochalasins, aspochalasin A1 (3) and cytochalasin Z24 (4), as well as eight known cytochalasin analogues (5–12) were isolated from the fermentation broth of Aspergillus elegans ZJ-2008010, a fungus obtained from a soft coral Sarcophyton sp. collected from the South China Sea. Their structures and the relative configurations were elucidated using comprehensive spectroscopic methods. The absolute configuration of 1 was determined by chemical synthesis and Marfey’s method. All isolated metabolites (1–12) were evaluated for their antifouling and antibacterial activities. Cytochalasins 5, 6, 8 and 9 showed strong antifouling activity against the larval settlement of the barnacle Balanus amphitrite, with the EC50 values ranging from 6.2 to 37 ?M. This is the first report of antifouling activity for this class of metabolites. Additionally, 8 exhibited a broad spectrum of antibacterial activity, especially against four pathogenic bacteria Staphylococcus albus, S. aureus, Escherichia coli and Bacillus cereus. PMID:23752358

  18. A new edge recognition technology based on the normalized vertical derivative of the total horizontal derivative for potential field data

    Microsoft Academic Search

    Wanyin Wang; Yu Pan; Zhiyun Qiu

    2009-01-01

    Edge detection and enhancement techniques are commonly used in recognizing the edge of geologic bodies using potential field\\u000a data. We present a new edge recognition technology based on the normalized vertical derivative of the total horizontal derivative\\u000a which has the functions of both edge detection and enhancement techniques. First, we calculate the total horizontal derivative\\u000a (THDR) of the potential-field data

  19. Atomistic simulation of gas transport in polyphosphazenes

    NASA Astrophysics Data System (ADS)

    Ren, Pengyu

    A molecular mechanics study of gas transport in polyphosphazenes is presented in this dissertation. First, a molecular mechanics force field, COMPASS, has been developed for phosphazenes, based on ab initio calculations and molecular dynamics simulations of condensed-phase properties. The force field has been extensively validated by simulation of a number of phosphazenes, in the gas, liquid and crystalline phase. Next, the resulting force field has been successfully applied in the MD simulation of the glass transitions of polyphosphazenes. It is demonstrated that different simulation methods will result in different equilibration states of the amorphous polymers. By building amorphous cells directly at different temperatures using RIS-based approach, better "equilibrated" structures and Tg are obtained. After the force field validation, self-diffusivities and solubilities of a number of gases in two polybutoxyphosphazene isomers---poly[bis( n-butoxy)phosphazene] (PnBuP) and poly[bis(sec-butoxy)phosphazene] (PsBuP) have been calculated from molecular dynamics and Monte Carlo simulations. The diffusion mechanism is studied by gas displacement analysis based on a unique approach that utilizes the digital signal filter to reduce the rattling motions while retaining the characteristic jumps of gas molecules. Finally the structure-property relationships for gas diffusion in rubbery polymers have been investigated by means of accessible free volume distribution and polymer chain dynamics. The polymers selected for this study are three polyphosphazenes isomers---PnBuP, PiBuP (poly[bis(iso-butoxy)phosphazene]), and PsBuP, and two other rubbery polymers---polydimethylsiloxane (PDMS) and polyisobutylene (PIB). Based on the Cohen and Turnbull free volume model for liquids, a statistical model for accessible free volume distribution in rubbery polymers has been derived and validated for above five polymers by simulations using the Transition State approach of Gusev and Suter. It has been shown that gas diffusivity has a linear dependence on the accessible free volume of the polymer. The simulation results indicate that the total free volume is related to the polymer backbone mobility while gas diffusivity is determined not only by the static accessible free volume but also by the dynamics of free volume redistribution that is dominated by the overall mobility of polymer backbone and side chain.

  20. Determination of rotor derivatives and rotor hub force and moment derivatives from flight measurements with the RSRA compound helicopter

    NASA Technical Reports Server (NTRS)

    Wang, Ji C.; Talbot, Peter D.

    1987-01-01

    A case study of the application of an integrated rotorcraft identification method to the linear modeling of rotor system dynamics and rotor hub loads is presented. Applying the method to flight data obtained from the RSRA compound helicopter, the rotor derivatives in the rotor state dynamic equation are identified along with blade equivalent damping and spring periodic coefficients. A rigid blade flapping equation of motion can be derived from the identified rotor state equation. It is shown that the concept of rotor hub load derivatives is useful for small maneuvering loads. The hub load derivatives can be used to relate the hub dynamic load to rotor/fuselage motion and applied inputs.

  1. Asymptotic Pricing of Commodity Derivatives using Stochastic Volatility Spot Models

    E-print Network

    Jaimungal, Sebastian

    of the NYMEX sweet crude oil spot price for the period 10/07/03 to 07/03/06. derivatives in Cotton, FouqueAsymptotic Pricing of Commodity Derivatives using Stochastic Volatility Spot Models Samuel is an essential feature of commodity spot prices. By using methods of singular perturbation theory, we obtain

  2. EH vs. CI chondrite derived mantle: A geodynamical comparison

    Microsoft Academic Search

    H. Samuel; C. G. Farnetani; M. Javoy

    2004-01-01

    It is generally assumed that the Earth's bulk composition is derived from carbonaceous CI chondrites. However, arguments based on stable isotopes and redox considerations favor another type of material from which the Earth could be derived: the enstatite EH chondrites. The latter implies substantial heterogeneities either in minor and major elements within the mantle which is strongly suggested by seismological

  3. Analytical and Numerical Methods for Pricing Financial Derivatives

    E-print Network

    Sevcovic, Daniel

    and pricing exotic financial derivatives 83 1. Asian options#12;Analytical and Numerical Methods for Pricing Financial Derivatives by Daniel Sevcovic Be´ata Stehl´ikov´a Karol Mikula #12;#12;Contents Introduction xi 1 The role of protecting financial portfolios

  4. Applying “Gold Standards” to In vitro-Derived Germ Cells

    PubMed Central

    Handel, Mary Ann; Eppig, John J.; Schimenti, John C.

    2015-01-01

    Germ cells are the ultimate stem cells and reports of their in vitro derivation generate excitement due to potential applications in reproductive medicine. To date there is no firm evidence that meiosis, the hallmark of gametogenesis, can be faithfully replicated outside the gonad. We propose benchmarks for evaluating in vitro derivation of germ cells, facilitating realization of their potential. PMID:24906145

  5. NOVEL SLURRY PHASE DIESEL CATALYSTS FOR COAL-DERIVED SYNGAS

    SciTech Connect

    Dr. Dragomir B. Bukur; Dr. Ketil Hanssen; Alec Klinghoffer; Dr. Lech Nowicki; Patricia O'Dowd; Dr. Hien Pham; Jian Xu

    2001-01-07

    This report describes research conducted to support the DOE program in novel slurry phase catalysts for converting coal-derived synthesis gas to diesel fuels. The primary objective of this research program is to develop attrition resistant catalysts that exhibit high activities for conversion of coal-derived syngas.

  6. Derivation, propagation and differentiation of human embryonic stem cells

    Microsoft Academic Search

    Brock J. Conley; Julia C. Young; Alan O. Trounson; Richard Mollard

    2004-01-01

    Embryonic stem (ES) cells are in vitro cultivated pluripotent cells derived from the inner cell mass (ICM) of the embryonic blastocyst. Attesting to their pluripotency, ES cells can be differentiated into representative derivatives of all three embryonic germ layers (endoderm, ectoderm and mesoderm) both in vitro and in vivo. Although mouse ES cells have been studied for many years, human

  7. DERIVATION OF FLUOROMETRIC CHLOROPHYLL AND PHEOPHYTIN EQUATIONS (JOURNAL VERSION)

    EPA Science Inventory

    Equations for calculation of chlorophyll a and pheophytin a by fluorometry have been cited in a number of publications. None of them, however, includes the derivation of the equations to substantiate their validity. The derivation is given here to let the user apply the equations...

  8. 21 CFR 189.120 - Cobaltous salts and its derivatives.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2009-04-01 true Cobaltous salts and its derivatives. 189.120 Section...Use as Human Food § 189.120 Cobaltous salts and its derivatives. (a) Cobaltous salts are the chemicals, CoC4 H6 O4 ,...

  9. 21 CFR 189.120 - Cobaltous salts and its derivatives.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Cobaltous salts and its derivatives. 189.120 Section...Use as Human Food § 189.120 Cobaltous salts and its derivatives. (a) Cobaltous salts are the chemicals, CoC4 H6 O4 ,...

  10. 21 CFR 189.120 - Cobaltous salts and its derivatives.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Cobaltous salts and its derivatives. 189.120 Section...Use as Human Food § 189.120 Cobaltous salts and its derivatives. (a) Cobaltous salts are the chemicals, CoC4 H6 O4 ,...

  11. 21 CFR 189.120 - Cobaltous salts and its derivatives.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Cobaltous salts and its derivatives. 189.120 Section...Use as Human Food § 189.120 Cobaltous salts and its derivatives. (a) Cobaltous salts are the chemicals, CoC4 H6 O4 ,...

  12. 21 CFR 189.120 - Cobaltous salts and its derivatives.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Cobaltous salts and its derivatives. 189.120 Section...Use as Human Food § 189.120 Cobaltous salts and its derivatives. (a) Cobaltous salts are the chemicals, CoC4 H6 O4 ,...

  13. New indene-derivatives with anti-proliferative properties.

    PubMed

    Karaguni, Ioanna-Maria; Glüsenkamp, Karl-Heinz; Langerak, Anette; Geisen, Christoph; Ullrich, Volker; Winde, Günther; Möröy, Tarik; Müller, Oliver

    2002-02-25

    Metabolites of the non-steroidal anti-inflammatory drug Sulindac inhibit cell proliferation by affecting several intracellular signaling pathways including the tumorigenic Ras/Raf/MAPK pathway. Here, we report the synthesis of eight new indene derivatives derived from the Sulindac structure, and present data on their anti-proliferative properties and their effects on the p21ras protein. PMID:11844707

  14. A Radon-Nikodym derivative for almost subadditive set functions

    E-print Network

    Paris-Sud XI, Université de

    EA 4272 A Radon-Nikodym derivative for almost subadditive set functions Yann REBILLE (*) 2009,version1-17Dec2009 #12;A Radon-Nikodym derivative for almost subadditive set functions Yann R Nantes Cedex 3, France. Abstract In classical measure theory, the Radon-Nikodym theorem states

  15. AAM Derived Face Representations for Robust Facial Action Recognition

    Microsoft Academic Search

    Simon Lucey; Iain Matthews; Changbo Hu; Zara Ambadar; Fernando De La Torre; Jeffrey F. Cohn

    2006-01-01

    In this paper, we present results on experiments employ- ing Active Appearance Model (AAM) derived facial rep- resentations, for the task of facial action recognition. Ex- perimental results demonstrate the benefit of AAM-derived representations on a spontaneous AU database containing \\

  16. New Exact Solutions of Differential Equations Derived by Fractional Calculus

    Microsoft Academic Search

    F. S. Felber

    2005-01-01

    Fractional calculus generalizes the derivative and antiderivative operations of differential and integral calculus from integer orders to the entire complex plane. Methods are presented for using this generalized calculus with Laplace transforms of complex-order derivatives to solve analytically many differential equations in physics, facilitate numerical computations, and generate new infinite-series representations of functions. As examples, new exact analytic solutions of

  17. On Valuation of Derivative Securities: A Lie Group Analytical Approach

    Microsoft Academic Search

    Phillip S. C. Yam; Hailiang Yang

    2006-01-01

    This paper proposes a Lie group analytical approach to tackle the problem of pricing derivative securities. By exploiting\\u000a the infinitesimal symmetries of the Boundary Value Problem (BVP) satisfied by the price of a derivative security, our method\\u000a provides an effective algorithm for obtaining its explicit solution.

  18. ORNL/TM-2008/107 The Enterprise Derivative Application

    E-print Network

    Pennycook, Steve

    i ORNL/TM-2008/107 The Enterprise Derivative Application: Flexible Software for Optimizing any of their employees, makes any warranty, express or implied, or assumes any legal liability/107 The Enterprise Derivative Application: Flexible Software for Optimizing Manufacturing Processes Glenn O. Allgood

  19. Instantaneous phase and frequency derived without user-defined parameters

    NASA Astrophysics Data System (ADS)

    Poggiagliolmi, E.; Vesnaver, A.

    2014-12-01

    We define an algorithm in the time domain for computing the unwrapped instantaneous phase and its derivative, the instantaneous frequency, using only derivatives and integrals. It does not require user-defined parameters, like most algorithms proposed so far. We validate and compare its performance with respect to open-source and commercial software by synthetic and real data examples.

  20. The Erroneous Derivative Examples of Eleventh Grade Students

    ERIC Educational Resources Information Center

    Gur, Hulya; Barak, Basak

    2007-01-01

    The derivative is not only an important subject for mathematics but also is an important subject for engineering, physics, economy, chemistry, and statistics. Especially, mathematics depends on strongly preceding learning and the subject of derivative will be used in university education by all students. Therefore, it is one of the most important…

  1. A Modular Derivation Strategy via Fusion and Tupling

    E-print Network

    Yamamoto, Hirosuke

    Zhenjiang Hu University of Tokyo Masato Takeichi University of Tokyo Abstract We show how programming pearls and transformation in our derivation. Keywords: Fusion, Tupling, Program Derivation, Programming Pearls. 1 Introduction A major impetus for highlighting programming pearls is to provide a better understanding of how

  2. Advertising in Google Search Deriving a bidding strategy

    E-print Network

    Boucherie, Richard J.

    Advertising in Google Search Deriving a bidding strategy in the biggest auction on earth. Anne This research aims to derive an optimal bidding strategy for keyword auctions in Google Search from;1 Preface We have conducted this research on Google auctions for our bachelor thesis of Applied Mathematics

  3. PRICING PRECIPITATION BASED DERIVATIVES RENE CARMONA AND PAVEL DIKO

    E-print Network

    Carmona, Rene

    compared to the other types of weather derivatives, let alone classical equity derivatives. From consider an economic agent whose time-invariant risk preferences are given by a utility function. Given and follow a self- financing strategy, re-balancing her portfolio in continuous time. She searches

  4. Novel aromatic carotenoid derivatives from sulfur photosynthetic bacteria in sediments

    Microsoft Academic Search

    Philippe Schaeffer; Pierre Adam; Patrick Wehrung; Pierre Albrecht

    1997-01-01

    Novel aromatic carotenoid derivatives 7 and 8 have been identified by synthesis of reference compounds in a H2\\/PtO2-hydrogenated fraction from the organic extract of a lake sediment (lake Cadagno, Switzerland). They derive from unreported carotenoids presumably biosynthesized by purple sulfur photosynthetic bacteria (Chromatiaceae) and represent potential biomarkers to establish the occurrence of photic zone anoxia in ancient ecosystems.

  5. Algorithm for generating derivative structures Gus L. W. Hart1

    E-print Network

    Hart, Gus

    Algorithm for generating derivative structures Gus L. W. Hart1 and Rodney W. Forcade2 1Department an algorithm for generating all derivative superstructures--for arbitrary parent structures and for any number of atom types. This algorithm enumerates superlattices and atomic configurations in a geometry

  6. On Two Forms of Bureaucracy in Derivations Kai Brunnler1

    E-print Network

    Sola, Rolf Haenni

    On Two Forms of Bureaucracy in Derivations Kai Br¨unnler1 and St´ephane Lengrand2 1 Institut f, France Abstract. We call irrelevant information in derivations bureaucracy. An example of such irrelevant by Guglielmi, we identify two forms of bureaucracy that occur in the calculus of structures (and, in fact

  7. Transformation relations for second derivatives of travel time

    E-print Network

    Cerveny, Vlastislav

    Transformation relations for second derivatives of travel time in anisotropic media Vlastislav In the computation of paraxial travel times and Gaussian beams, the basic role is played by second derivatives of the travel-time field at the reference ray . These deriva- tives can be determined by dynamic ray tracing

  8. On the derivation of the Herman Kluk propagator

    NASA Astrophysics Data System (ADS)

    Deshpande, Sarin A.; Ezra, Gregory S.

    2006-05-01

    Following an earlier derivation by Miller, we give a concise derivation of the Herman-Kluk propagator that fully exploits the symplectic structure of the problem. We also show directly that the version of the thawed Gaussian semiclassical propagator obtained by Baranger and co-workers is equivalent to the linearized Herman-Kluk propagator.

  9. Andrographolide: A New Plant-Derived Antineoplastic Entity on Horizon

    Microsoft Academic Search

    Astha Varma; Harish Padh; Neeta Shrivastava

    2009-01-01

    Plant-derived natural products occupy an important position in the area of cancer chemo- therapy. Molecules such as vincristine, vinblastine, paclitaxel, camptothecin derivatives, epipo- dophyllotoxin, etc. are invaluable contributions of nature to modern medicine. However, the quest to find out novel therapeutic compounds for cancer treatment and management is a never-ending venture; and diverse plant species are persistently being studied for

  10. Derivation of signatures for faults in gas turbine compressor blading

    Microsoft Academic Search

    N. Aretakis; K. Mathioudakis; V. Dedoussis

    1998-01-01

    A procedure for the derivation of signatures for faults in the blades of a gas turbine is presented here. A variety of blade faults, corresponding to changes in the angle or spacing of one or more blades, are examined. A fluid dynamic simulation model is used to derive the unsteady pressure signals sensed by a stationary transducer for the cases

  11. BPS states in supersymmetric chiral models with higher derivative terms

    NASA Astrophysics Data System (ADS)

    Nitta, Muneto; Sasaki, Shin

    2014-11-01

    We study the higher derivative chiral models with four supercharges and Bogomol'nyi-Prasad-Sommerfield (BPS) states in these models. The off-shell Lagrangian generically includes higher powers of the auxiliary fields F , which causes distinct on-shell branches associated with the solutions to the auxiliary fields equation. We point out that the model admits a supersymmetric completion of arbitrary higher derivative bosonic models of a single complex scalar field, and an arbitrary scalar potential can be introduced even without superpotentials. As an example, we present a supersymmetric extension of the Faddeev-Skyrme model without four time derivatives, in contrast to the previously proposed supersymmetric Faddeev-Skyrme-like model containing four time derivatives. In general, higher derivative terms together with a superpotential result in deformed scalar potentials. We find that higher derivative corrections to 1 /2 BPS domain walls and 1 /2 BPS lumps are exactly canceled out, while the 1 /4 BPS lumps (as compact baby Skyrmions) depend on a characteristic feature of the higher derivative models. We also find a new 1 /4 BPS condition for domain wall junctions, which generically receives higher derivative corrections.

  12. 15 Software Product Line Engineering with the UML: Deriving Products

    E-print Network

    Paris-Sud XI, Université de

    15 Software Product Line Engineering with the UML: Deriving Products T. Ziadi and J.-M. Jézéquel Abstract Software product line engineering introduces two new dimensions into the traditional engineering of software-based systems: the variability modeling and the product derivation. The variability gathers

  13. Size Efficient Parallel Algebraic Circuits for Partial Derivatives*

    E-print Network

    Kaltofen, Erich

    Size Efficient Parallel Algebraic Circuits for Partial Derivatives* Erich Kaltofen1 and Michael F@matagh.ncsu.edu Abstract. Given an algebraic circuit or straight-line program of depth d that computes multivariate circuits that compute (1) the first k partial derivatives in a single variable with depth O(log(k)(d + log

  14. Path integral derivations of novel complex trajectory methods

    E-print Network

    Schiff, Jeremy

    Path integral derivations of novel complex trajectory methods Jeremy Schiff1 , Yair Goldfarb2 integral derivations are presented for two recently developed complex trajectory techniques and the phase of the intial wave function, thus giving rise to the need for complex classical trajectories

  15. Functional Characterization of Embryonic Stem Cell-Derived Endothelial Cells

    Microsoft Academic Search

    Drew E. Glaser; Robert M. Gower; Nicholas E. Lauer; Kayan Tam; Alicia A. Blancas; Albert J. Shih; Scott I. Simon; Kara E. McCloskey

    2011-01-01

    Endothelial cells (EC) derived from embryonic stem cells (ESC) require additional functional characterization before they are used as a cell therapy in order to enhance their potential for engraftment and proliferation. We explore several physiologically relevant functions of ESC-derived EC (ESC-EC), such as its capacity to produce nitric oxide (NO), regulate permeability, activate and express surface molecules for the recruitment

  16. NOVEL SLURRY PHASE DIESEL CATALYSTS FOR COAL-DERIVED SYNGAS

    Microsoft Academic Search

    Dragomir B. Bukur; Ketil Hanssen; Alec Klinghoffer; Lech Nowicki; Patricia ODowd; Hien Pham; Jian Xu

    2001-01-01

    This report describes research conducted to support the DOE program in novel slurry phase catalysts for converting coal-derived synthesis gas to diesel fuels. The primary objective of this research program is to develop attrition resistant catalysts that exhibit high activities for conversion of coal-derived syngas.

  17. Bounds on the Relative Entropy Derivative Pablo Zegers

    E-print Network

    Slatton, Clint

    on the Relative Entropy Derivative #12;Motivation Gravitational Forces: Physics Says Model each gravitational pull on the Relative Entropy Derivative #12;Motivation Gravitational Forces: What Really Exists! A sun surrounded by N stars. Each star causes a gravitational tug on this sun. Orion starfield (wikipedia). Zegers Bounds

  18. Mesenchymal Stem Cell-Derived Molecules Reverse Fulminant Hepatic Failure

    Microsoft Academic Search

    Biju Parekkadan; Daan van Poll; Kazuhiro Suganuma; Edward A. Carter; François Berthiaume; Arno W. Tilles; Martin L. Yarmush; Fu-Sheng Wang

    2007-01-01

    Modulation of the immune system may be a viable alternative in the treatment of fulminant hepatic failure (FHF) and can potentially eliminate the need for donor hepatocytes for cellular therapies. Multipotent bone marrow-derived mesenchymal stem cells (MSCs) have been shown to inhibit the function of various immune cells by undefined paracrine mediators in vitro. Yet, the therapeutic potential of MSC-derived

  19. Shear Viscosity to Entropy Density Ratio in Six Derivative Gravity

    E-print Network

    Nabamita Banerjee; Suvankar Dutta

    2009-04-01

    We calculate shear viscosity to entropy density ratio in presence of four derivative (with coefficient $\\alpha'$) and six derivative (with coefficient $\\alpha'^2$) terms in bulk action. In general, there can be three possible four derivative terms and ten possible six derivative terms in the Lagrangian. Among them two four derivative and eight six derivative terms are ambiguous, i.e., these terms can be removed from the action by suitable field redefinitions. Rest are unambiguous. According to the AdS/CFT correspondence all the unambiguous coefficients (coefficients of unambiguous terms) can be fixed in terms of field theory parameters. Therefore, any measurable quantities of boundary theory, for example shear viscosity to entropy density ratio, when calculated holographically can be expressed in terms of unambiguous coefficients in the bulk theory (or equivalently in terms of boundary parameters). We calculate $\\eta/s$ for generic six derivative gravity and find that apparently it depends on few ambiguous coefficients at order $\\alpha'^2$. We calculate six derivative corrections to central charges $a$ and $c$ and express $\\eta/s$ in terms of these central charges and unambiguous coefficients in the bulk theory.

  20. Automatic Memory Optimizations for Improving MPI Derived Datatype Performance

    E-print Network

    Thakur, Rajeev

    Automatic Memory Optimizations for Improving MPI Derived Datatype Performance Surendra Byna1, Xian Laboratory, Argonne, IL, USA {thakur, gropp}@mcs.anl.gov Abstract. MPI derived datatypes allow users function. This powerful feature enables an MPI implementation to optimize the transfer of noncontiguous

  1. Performance Expectations and Guidelines for MPI Derived Datatypes

    E-print Network

    Thakur, Rajeev

    Performance Expectations and Guidelines for MPI Derived Datatypes William Gropp,1 Torsten Hoefler,1, Austria, traff@par.univie.ac.at Abstract. MPI's derived datatypes provide a powerful mechanism for concisely describing arbitrary, noncontiguous layouts of user data for use in MPI communication. This paper

  2. Regioselective Enzymatic Carboxylation of Phenols and Hydroxystyrene Derivatives

    PubMed Central

    2012-01-01

    The enzymatic carboxylation of phenol and styrene derivatives using (de)carboxylases in carbonate buffer proceeded in a highly regioselective fashion: Benzoic acid (de)carboxylases selectively formed o-hydroxybenzoic acid derivatives, phenolic acid (de)carboxylases selectively acted at the ?-carbon atom of styrenes forming (E)-cinnamic acids. PMID:22471935

  3. Formal Derivation of Direct Torque Control for Induction Machines

    Microsoft Academic Search

    Zakdy Sorchini; Philip T. Krein

    2006-01-01

    Direct torque control (DTC) is an induction motor control technique that has been successful because it explicitly considers the inverter stage and uses few machine parameters, while being more robust to parameter uncertainty than field-oriented control (FOC). This paper presents a formal derivation of DTC based on singular perturbation and nonlinear control tools. The derivation elaborates an explicit relationship between

  4. Derivation of sequential, real-time, process-control programs

    NASA Technical Reports Server (NTRS)

    Marzullo, Keith; Schneider, Fred B.; Budhiraja, Navin

    1991-01-01

    The use of weakest-precondition predicate transformers in the derivation of sequential, process-control software is discussed. Only one extension to Dijkstra's calculus for deriving ordinary sequential programs was found to be necessary: function-valued auxiliary variables. These auxiliary variables are needed for reasoning about states of a physical process that exists during program transitions.

  5. Derived categories of coherent sheaves and equivalences between them

    NASA Astrophysics Data System (ADS)

    Orlov, D. O.

    2003-06-01

    This paper studies the derived categories of coherent sheaves on smooth complete algebraic varieties and equivalences between them. We prove that every equivalence of categories is represented by an object on the product of the varieties. This result is applied to describe the Abelian varieties and K3 surfaces that have equivalent derived categories of coherent sheaves.

  6. Structures and burning velocity of biomass derived gas flames

    Microsoft Academic Search

    C. Liu; B. Yan; G. Chen; X. S. Bai

    2010-01-01

    Biomass derived gases produced via gasification, pyrolysis, and fermentation are carbon neutral alternative fuels that can be used in gas turbines, furnaces, and piston engines. To make use of these environmentally friendly but energy density low fuels the combustion characteristics of these fuels have to be fully understood. In this study the structure and laminar burning velocity of biomass derived

  7. Seven Year Climatologies derived from the Atmospheric Infrared Sounder (AIRS)

    Microsoft Academic Search

    T. J. Hearty; A. K. Savtchenko; Y. Won; M. Theobald; B. Vollmer; E. Manning; P. M. Smith; D. Ostrenga

    2009-01-01

    We examine climatologies derived from 7 years of Temperature, Water Vapor, Cloud, and Trace Gas measurements made by the Atmospheric Infrared Sounder (AIRS). We compare the AIRS climatologies to similar climatologies derived from forecast data and data from MERRA (the Modern Era Retrospective-Analysis for Research and Applications). We also use the AIRS climatologies to examine anomaly trends in the AIRS

  8. PSERC 98-21 "Analytic and Experimentally-Derived

    E-print Network

    PSERC 98-21 "Analytic and Experimentally-Derived Estimates of Market Power in Deregulated, January 5-8, 1999nd "Analytic and Experimentally-Derived Estimates of Market Power in Deregulated, Cornell Institute for Public Affairs Cornell University 422 Hollister Hall Ithaca, NY 14853-3501 res1

  9. Multi-Factor Energy Price Models Exotic Derivatives Pricing

    E-print Network

    Jaimungal, Sebastian

    Multi-Factor Energy Price Models and Exotic Derivatives Pricing by Samuel Hikspoors A thesis of Statistics University of Toronto c Copyright by Samuel Hikspoors 2008 #12;Multi-Factor Energy Price Models and practitioners alike recently started to develop the tools of energy derivatives pricing

  10. Product Model Derivation by Model Transformation in Software Product Lines

    Microsoft Academic Search

    Rasha Tawhid; Dorina C. Petriu

    2011-01-01

    Product derivation is an essential part of the Software Product Line (SPL) development process. The paper proposes a model transformation for deriving automatically a UML model of a specific product from the UML model of a product line. This work is a part of a larger project aiming to integrate performance analysis in the SPL model-driven development. The SPL source

  11. Dihydroagarofuran derivatives from the dried roots of Tripterygium wilfordii.

    PubMed

    Luo, Yinggang; Zhou, Min; Ye, Qi; Pu, Qiang; Zhang, Guolin

    2012-01-27

    Five new sesquiterpene derivatives, including dihydroagarofuran pyridine macrolides 1-4 and dihydroagarofuran ester 18, and 13 known dihydroagarofuran derivatives were isolated from the aqueous EtOH extract of the dried roots of Tripterygium wilfordii. An in vitro antiherpetic activity assay indicated that compounds 11 and 17 displayed weak and moderate inhibition against herpes simplex virus type II, respectively. PMID:22148431

  12. THE GENERATING HYPOTHESIS IN THE DERIVED CATEGORY OF A RING

    E-print Network

    Hovey, Mark

    THE GENERATING HYPOTHESIS IN THE DERIVED CATEGORY OF A RING MARK HOVEY, KEIR LOCKRIDGE, AND GENA PUNINSKI Abstract. We show that a strong form (the fully faithful version) of the generating hypothesis the original form (the faithful version) of the generating hypothesis holds in the derived category of R

  13. Derivation of hierarchies of reduced MHD models in Tokamak geometry

    E-print Network

    Paris-Sud XI, Université de

    Derivation of hierarchies of reduced MHD models in Tokamak geometry Bruno Despr´es and R´emy Sart is very adapted to the complicated geometry of the torus. We obtain a comparaison principle between all these models. A new correction term due to the geometry is derived which is important for the stability

  14. Naphthazarin derivatives from cultures of the lichen Cladonia cristatella

    Microsoft Academic Search

    Yoshikazu Yamamoto; Hideki Matsubara; Yasuhiro Kinoshita; Kaoru Kinoshita; Kiyotaka Koyama; Kunio Takahashi; Vernon Ahmadjiam; Teiko Kurokawa; Isao Yoshimura

    1996-01-01

    High pigment-producing cell aggregates of the cultured spore-derived mycobiont of a lichen, Cladonia cristatella, were isolated by clonal selection. The new naphthazarin derivatives, cristazarin (3-ethyl-2-hydroxy-7-methoxynaphthazarin) and 6-methylcristazarin, were identified as red pigments from the liquid culture. A depside, barbatic acid, was also detected in C. cristatella and Acarospora fuscata mycobiont liquid cultures.

  15. Projective Bundles, Monoidal Transformations, and Derived Categories of Coherent Sheaves

    NASA Astrophysics Data System (ADS)

    Orlov, D. O.

    1993-02-01

    This paper studies derived categories of coherent sheaves on varieties that are obtained by projectivization of vector bundles and by monoidal transformations. Conditions for the existence of complete exceptional sets in such categories are derived; they give new examples of varieties on which exceptional sets exist.

  16. Asymptotic Safety and Higher Derivative Gravity Frank Saueressig

    E-print Network

    Rossak, Wilhelm R.

    independent of UV-completion · beyond perturbation theory: renormalization group flow for gravity Newtons: Quantum Theory for Gravity ­ p. 3/4 #12;Quantizing gravity · Physics of Quantum Gravity: Planck scale: Pl quantization: Higher-derivative gravity (= add 4-derivative terms) Improved UV behavior theory

  17. Synthesis of (-)-arctigenin derivatives and their anticancer activity.

    PubMed

    Gui-Rong, Chen; Li-Ping, Cai; De-Qiang, Dou; Ting-Guo, Kang; Hong-Fu, Li; Fu-Rui, Li; Ning, Jiang

    2012-01-01

    The natural dibenzylbutyrolactone type lignanolide (-)-arctigenin, which was prepared from fructus arctii, showed obvious anticancer activity. The synthesis of four new (-)-arctigenin derivatives and their anticancer bioactivities were examined. The structures of the four new synthetic derivatives were elucidated. PMID:21867457

  18. Scaled discrete derivatives of singularly perturbed elliptic problems

    E-print Network

    Scaled discrete derivatives of singularly perturbed elliptic problems J. L. Gracia E. O'Riordan June 19, 2013 Abstract Numerical approximations to the solution of a singularly perturbed elliptic Classification: 65M15,65M12, 65M06 Key Words: Singular perturbation, approximation of derivatives, Shishkin mesh

  19. Deriving a Bilingual Lexicon for Cross Language Information Retrieval

    E-print Network

    Hiemstra, Djoerd

    Deriving a Bilingual Lexicon for Cross Language Information Retrieval D. Hiemstra Department@cs.utwente.nl Abstract In this paper we describe a systematic approach to derive a bilingual lexicon automatically from, a bilingual retrieval environment was build. Recall and precision of monolingual (Dutch) retrieval

  20. Derivative of Area Equals Perimeter--Coincidence or Rule?

    ERIC Educational Resources Information Center

    Zazkis, Rina; Sinitsky, Ilya; Leikin, Roza

    2013-01-01

    Why is the derivative of the area of a circle equal to its circumference? Why is the derivative of the volume of a sphere equal to its surface area? And why does a similar relationship not hold for a square or a cube? Or does it? In their work in teacher education, these authors have heard at times undesirable responses to these questions:…