The in vivo characteristics of genetically engineered divalent and tetravalent single-chain antibody constructs

International Nuclear Information System (INIS)

Wittel, Uwe A.; Jain, Maneesh; Goel, Apollina; Chauhan, Subhash C.; Colcher, David; Batra, Surinder K.

2005-01-01

Engineered multivalent single-chain Fv (scFv) constructs have been demonstrated to exhibit rapid blood clearance and better tumor penetration. To understand the short plasma half-life of multivalent single-chain antibody fragments, the pharmacokinetic properties of covalent dimeric scFv [sc(Fv) 2 ], noncovalent tetrameric scFv {[sc(Fv) 2 ] 2 } and IgG of MAb CC49 were examined. The scFvs displayed an ability to form higher molecular aggregates in vivo. A specific proteolytic cleavage of the linker sequence of the covalent dimeric or a deterioration of the noncovalent association of the dimeric scFv into tetravalent scFv constructs was not observed. In conclusion, sc(Fv) 2 and [sc(Fv) 2 ] 2 are stable in vivo and have significant potential for diagnostic and therapeutic applications

Supramolecular Nanoparticles via Single-Chain Folding Driven by Ferrous Ions.

Science.gov (United States)

Wang, Fei; Pu, Hongting; Jin, Ming; Wan, Decheng

2016-02-01

Single-chain nanoparticles can be obtained via single-chain folding assisted by intramolecular crosslinking reversibly or irreversibly. Single-chain folding is also an efficient route to simulate biomacromolecules. In present study, poly(N-hydroxyethylacrylamide-co-4'-(propoxy urethane ethyl acrylate)-2,2':6',2''-terpyridine) (P(HEAm-co-EMA-Tpy)) is synthesized via reversible addition fragmentation chain transfer polymerization. Single-chain folding and intramolecular crosslinking of P(HEAm-co-EMA-Tpy) are achieved via metal coordination chemistry. The intramolecular interaction is characterized on ultraviolet/visible spectrophotometer (UV-vis spectroscopy), proton nuclear magnetic resonance ((1)H NMR), and differential scanning calorimetry (DSC). The supramolecular crosslinking mediated by Fe(2+) plays an important role in the intramolecular collapsing of the single-chain and the formation of the nanoparticles. The size and morphology of the nanoparticles can be controlled reversibly via metal coordination chemistry, which can be characterized by dynamic light scattering (DLS), transmission electron microscope (TEM), and atomic force microscope (AFM). © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effect of Chain Conformation on the Single-Molecule Melting Force in Polymer Single Crystals: Steered Molecular Dynamics Simulations Study.

Science.gov (United States)

Feng, Wei; Wang, Zhigang; Zhang, Wenke

2017-02-28

Understanding the relationship between polymer chain conformation as well as the chain composition within the single crystal and the mechanical properties of the corresponding single polymer chain will facilitate the rational design of high performance polymer materials. Here three model systems of polymer single crystals, namely poly(ethylene oxide) (PEO), polyethylene (PE), and nylon-66 (PA66) have been chosen to study the effects of chain conformation, helical (PEO) versus planar zigzag conformation (PE, PA66), and chain composition (PE versus PA66) on the mechanical properties of a single polymer chain. To do that, steered molecular dynamics simulations were performed on those polymer single crystals by pulling individual polymer chains out of the crystals. Our results show that the patterns of force-extension curve as well as the chain moving mode are closely related to the conformation of the polymer chain in the single crystal. In addition, hydrogen bonds can enhance greatly the force required to stretch the polymer chain out of the single crystal. The dynamic breaking and reformation of multivalent hydrogen bonds have been observed for the first time in PA66 at the single molecule level.

Purification, crystallization, X-ray diffraction analysis and phasing of an engineered single-chain PvuII restriction endonuclease

International Nuclear Information System (INIS)

Meramveliotaki, Chrysi; Kotsifaki, Dina; Androulaki, Maria; Hountas, Athanasios; Eliopoulos, Elias; Kokkinidis, Michael

2007-01-01

PvuII is the first type II restriction endonuclease to be converted from its wild-type homodimeric form into an enzymatically active single-chain variant. The enzyme was crystallized and phasing was successfully performed by molecular replacement. The restriction endonuclease PvuII from Proteus vulgaris has been converted from its wild-type homodimeric form into the enzymatically active single-chain variant scPvuII by tandemly joining the two subunits through the peptide linker Gly-Ser-Gly-Gly. scPvuII, which is suitable for the development of programmed restriction endonucleases for highly specific DNA cleavage, was purified and crystallized. The crystals diffract to a resolution of 2.35 Å and belong to space group P4 2 , with unit-cell parameters a = b = 101.92, c = 100.28 Å and two molecules per asymmetric unit. Phasing was successfully performed by molecular replacement

Domain walls in single-chain magnets

Science.gov (United States)

Pianet, Vivien; Urdampilleta, Matias; Colin, Thierry; Clérac, Rodolphe; Coulon, Claude

2017-12-01

The topology and creation energy of domain walls in different magnetic chains (called Single-Chain Magnets or SCMs) are discussed. As these domain walls, that can be seen as "defects", are known to control both static and dynamic properties of these one-dimensional systems, their study and understanding are necessary first steps before a deeper discussion of the SCM properties at finite temperature. The starting point of the paper is the simple regular ferromagnetic chain for which the characteristics of the domain walls are well known. Then two cases will be discussed (i) the "mixed chains" in which isotropic and anisotropic classical spins alternate, and (ii) the so-called "canted chains" where two different easy axis directions are present. In particular, we show that "strictly narrow" domain walls no longer exist in these more complex cases, while a cascade of phase transitions is found for canted chains as the canting angle approaches 45∘. The consequence for thermodynamic properties is briefly discussed in the last part of the paper.

An unusual hybrid fluoride featuring a [V7F27]6- chain motif based on a pyrochlore-like building unit

International Nuclear Information System (INIS)

Aldous, David W.; Slawin, Alexandra M.Z.; Lightfoot, Philip

2008-01-01

A new hybrid vanadium (III) fluoride [C 4 H 12 N 2 ] 3 [V 7 F 27 ] has been synthesised solvothermally. The crystal structure (trigonal, R3-bar c; a=17.367(2) A, c=19.604(2) A) reveals an unusual and novel chain motif consisting of pyrochlore-like heptameric units of corner-sharing octahedra, which are further linked into linear chains of alternating triple and single octahedral groups. The chains are separated by hydrogen-bonded piperazinium moieties. Magnetic susceptibility data show moderate antiferromagnetic interactions but no long-range order above 2 K, consistent with pronounced one-dimensional character, as well as frustration arising within the triangular units of magnetic ions in the chains. - Graphical abstract: A unique chain-structure vanadium(III) fluoride [C 4 H 12 N 2 ] 3 [V 7 F 27 ], based on a pyrochlore-like building unit, has been prepared solvothermally. Despite antiferromagnetic interactions, no long-range magnetic order occurs above 2 K, suggesting possible frustration

Elementary excitations in single-chain magnets

Science.gov (United States)

Lutz, Philipp; Aguilà, David; Mondal, Abhishake; Pinkowicz, Dawid; Marx, Raphael; Neugebauer, Petr; Fâk, Björn; Ollivier, Jacques; Clérac, Rodolphe; van Slageren, Joris

2017-09-01

Single-chain magnets (SCMs) are one-dimensional coordination polymers or spin chains that display slow relaxation of the magnetization. Typically their static magnetic properties are described by the Heisenberg model, while the description of their dynamic magnetic properties is based on an Ising-like model. The types of excitations predicted by these models (collective vs localized) are quite different. Therefore we probed the nature of the elementary excitations for two SCMs abbreviated Mn2Ni and Mn2Fe , as well as a mononuclear derivative of the Mn2Fe chain, by means of high-frequency electron paramagnetic resonance spectroscopy (HFEPR) and inelastic neutron scattering (INS). We find that the HFEPR spectra of the chains are clearly distinct from those of the monomer. The momentum transfer dependence of the INS intensity did not reveal significant dispersion, indicating an essentially localized nature of the excitations. At the lowest temperatures these are modified by the occurrence of short-range correlations.

Development of two dimensional electrophoresis method using single chain DNA

International Nuclear Information System (INIS)

Ikeda, Junichi; Hidaka, So

1998-01-01

By combining a separation method due to molecular weight and a method to distinguish difference of mono-bases, it was aimed to develop a two dimensional single chain DNA labeled with Radioisotope (RI). From electrophoretic pattern difference of parent and variant strands, it was investigated to isolate the root module implantation control gene. At first, a Single Strand Conformation Polymorphism (SSCP) method using concentration gradient gel was investigated. As a result, it was formed that intervals between double chain and single chain DNAs expanded, but intervals of both single chain DNAs did not expand. On next, combination of non-modified acrylic amide electrophoresis method and Denaturing Gradient-Gel Electrophoresis (DGGE) method was examined. As a result, hybrid DNA developed by two dimensional electrophoresis arranged on two lines. But, among them a band of DNA modified by high concentration of urea could not be found. Therefore, in this fiscal year's experiments, no preferable result could be obtained. By the used method, it was thought to be impossible to detect the differences. (G.K.)

Formalizing the Process of Constructing Chains of Lexical Units

Directory of Open Access Journals (Sweden)

Grigorij Chetverikov

2015-06-01

Full Text Available Formalizing the Process of Constructing Chains of Lexical Units The paper investigates mathematical aspects of describing the construction of chains of lexical units on the basis of finite-predicate algebra. Analyzing the construction peculiarities is carried out and application of the method of finding the power of linear logical transformation for removing characteristic words of a dictionary entry is given. Analysis and perspectives of the results of the study are provided.

Structural effects of a light emitting copolymer having perylene moieties in the side chain on the electroluminescent characteristics

International Nuclear Information System (INIS)

Lee, Chang Ho; Ryu, Seung Hoon; Jang, Hee Dong; Oh, Se Young

2004-01-01

We have synthesized a novel side chain light emitting copolymer. The side chain light emitting copolymer has a perylene moiety as an emitting unit and methylmethacrylate (MMA) as a spacer to decrease the concentration quenching of light emitting site in the polymer intrachain. These polymers are very soluble in most organic solvents such as monochlorobenzene, tetrahydrofuran, chloroform and benzene. The single-layered electroluminescent (EL) device consisting of ITO/carrier transporting copolymer and light emitting copolymer/Al was manufactured. The carrier transporting copolymer has triphenylamine moiety as a hole transporting unit and triazine moiety as an electron transporting unit in the polymer side chain. This device exhibits maximum external quantum efficiency when the MMA contents of light emitting copolymer is 30 wt.%. In particular, the device emits more blue light as MMA contents increase

Single-copy entanglement in critical quantum spin chains

International Nuclear Information System (INIS)

Eisert, J.; Cramer, M.

2005-01-01

We consider the single-copy entanglement as a quantity to assess quantum correlations in the ground state in quantum many-body systems. We show for a large class of models that already on the level of single specimens of spin chains, criticality is accompanied with the possibility of distilling a maximally entangled state of arbitrary dimension from a sufficiently large block deterministically, with local operations and classical communication. These analytical results--which refine previous results on the divergence of block entropy as the rate at which maximally entangled pairs can be distilled from many identically prepared chains--are made quantitative for general isotropic translationally invariant spin chains that can be mapped onto a quasifree fermionic system, and for the anisotropic XY model. For the XX model, we provide the asymptotic scaling of ∼(1/6)log 2 (L), and contrast it with the block entropy

Unconventional phase transitions in a constrained single polymer chain

International Nuclear Information System (INIS)

Klushin, L I; Skvortsov, A M

2011-01-01

Phase transitions were recognized among the most fascinating phenomena in physics. Exactly solved models are especially important in the theory of phase transitions. A number of exactly solved models of phase transitions in a single polymer chain are discussed in this review. These are three models demonstrating the second order phase transitions with some unusual features: two-dimensional model of β-structure formation, the model of coil–globule transition and adsorption of a polymer chain grafted on the solid surface. We also discuss models with first order phase transitions in a single macromolecule which admit not only exact analytical solutions for the partition function with explicit finite-size effects but also the non-equilibrium free energy as a function of the order parameter (Landau function) in closed analytical form. One of them is a model of mechanical desorption of a macromolecule, which demonstrates an unusual first order phase transition with phase coexistence within a single chain. Features of first and second order transitions become mixed here due to phase coexistence which is not accompanied by additional interfacial free energy. Apart from that, there exist several single-chain models belonging to the same class (adsorption of a polymer chain tethered near the solid surface or liquid–liquid interface, and escape transition upon compressing a polymer between small pistons) that represent examples of a highly unconventional first order phase transition with several inter-related unusual features: no simultaneous phase coexistence, and hence no phase boundary, non-concave thermodynamic potential and non-equivalence of conjugate ensembles. An analysis of complex zeros of partition functions upon approaching the thermodynamic limit is presented for models with and without phase coexistence. (topical review)

Use of supply chains and supply chain managment to improve the efficiency and effectiveness of GIS units

CSIR Research Space (South Africa)

Schmitz, Peter MU

2007-06-01

Full Text Available The objective of this study is to provide a tool, namely the establishment of supply chains and supply chain management to manage this chain, enabling a GIS unit to respond to the needs of their customers with the right product at the right time...

Equivalence of chain conformations in the surface region of a polymer melt and a single Gaussian chain under critical conditions.

Science.gov (United States)

Skvortsov, A M; Leermakers, F A M; Fleer, G J

2013-08-07

In the melt polymer conformations are nearly ideal according to Flory's ideality hypothesis. Silberberg generalized this statement for chains in the interfacial region. We check the Silberberg argument by analyzing the conformations of a probe chain end-grafted at a solid surface in a sea of floating free chains of concentration φ by the self-consistent field (SCF) method. Apart from the grafting, probe chain and floating chains are identical. Most of the results were obtained for a standard SCF model with freely jointed chains on a six-choice lattice, where immediate step reversals are allowed. A few data were generated for a five-choice lattice, where such step reversals are forbidden. These coarse-grained models describe the equilibrium properties of flexible atactic polymer chains at the scale of the segment length. The concentration was varied over the whole range from φ = 0 (single grafted chain) to φ = 1 (probe chain in the melt). The number of contacts with the surface, average height of the free end and its dispersion, average loop and train length, tail size distribution, end-point and overall segment distributions were calculated for a grafted probe chain as a function of φ, for several chain lengths and substrate∕polymer interactions, which were varied from strong repulsion to strong adsorption. The computations show that the conformations of the probe chain in the melt do not depend on substrate∕polymer interactions and are very similar to the conformations of a single end-grafted chain under critical conditions, and can thus be described analytically. When the substrate∕polymer interaction is fixed at the value corresponding to critical conditions, all equilibrium properties of a probe chain are independent of φ, over the whole range from a dilute solution to the melt. We believe that the conformations of all flexible chains in the surface region of the melt are close to those of an appropriate single chain in critical conditions, provided

Chain formation of metal atoms

DEFF Research Database (Denmark)

Bahn, Sune Rastad; Jacobsen, Karsten Wedel

2001-01-01

The possibility of formation of single-atomic chains by manipulation of nanocontacts is studied for a selection of metals (Ni, Pd, Pt, Cu, Ag, Au). Molecular dynamics simulations show that the tendency for chain formation is strongest for Au and Pt. Density functional theory calculations indicate...... that the metals which form chains exhibit pronounced many-atom interactions with strong bonding in low coordinated systems....

Effect of chain stiffness on the structure of single-chain polymer nanoparticles

Science.gov (United States)

Moreno, Angel J.; Bacova, Petra; Lo Verso, Federica; Arbe, Arantxa; Colmenero, Juan; Pomposo, José A.

2018-01-01

Polymeric single-chain nanoparticles (SCNPs) are soft nano-objects synthesized by purely intramolecular cross-linking of single polymer chains. By means of computer simulations, we investigate the conformational properties of SCNPs as a function of the bending stiffness of their linear polymer precursors. We investigate a broad range of characteristic ratios from the fully flexible case to those typical of bulky synthetic polymers. Increasing stiffness hinders bonding of groups separated by short contour distances and increases looping over longer distances, leading to more compact nanoparticles with a structure of highly interconnected loops. This feature is reflected in a crossover in the scaling behaviour of several structural observables. The scaling exponents change from those characteristic for Gaussian chains or rings in θ-solvents in the fully flexible limit, to values resembling fractal or ‘crumpled’ globular behaviour for very stiff SCNPs. We characterize domains in the SCNPs. These are weakly deformable regions that can be seen as disordered analogues of domains in disordered proteins. Increasing stiffness leads to bigger and less deformable domains. Surprisingly, the scaling behaviour of the domains is in all cases similar to that of Gaussian chains or rings, irrespective of the stiffness and degree of cross-linking. It is the spatial arrangement of the domains which determines the global structure of the SCNP (sparse Gaussian-like object or crumpled globule). Since intramolecular stiffness can be varied through the specific chemistry of the precursor or by introducing bulky side groups in its backbone, our results propose a new strategy to tune the global structure of SCNPs.

[Fe(III)(dmbpy)(CN)4]-: a new building block for designing single-chain magnets.

Science.gov (United States)

Toma, Luminita Marilena; Pasán, Jorge; Ruiz-Pérez, Catalina; Lloret, Francesc; Julve, Miguel

2012-11-28

We herein present the synthesis and magneto-structural study of a new family of heterobimetallic chains of general formula {[Fe(III)(dmbpy)(CN)(4)](2)M(II)(H(2)O)(2)}(n)·pnH(2)O [dmbpy = 4,4'-dimethyl-2,2'-bipyridine; M = Mn (2), Cu (3), Ni (4) and Co (5) with p = 4 (2), 3 (3), 9 (4) and 3.5 (5)] which were prepared by using the mononuclear PPh(4)[Fe(III)(dmbpy)(CN)(4)]·3H(2)O (1) building block (PPh(4)(+) = tetraphenylphosphonium) as a ligand toward fully solvated M(II) ions. The structure of 1 consists of discrete [Fe(III)(dmbpy)(CN)(4)](-) anions, tetraphenylphosphonium cations and noncoordinated water molecules. Complexes 2-5 are isostructural compounds whose structure consists of neutral 4,2-wave like heterobimetallic chains of formula {[Fe(III)(dmbpy)(CN)(4)](2)M(II)(H(2)O)(2)}(n) where the [Fe(III)(dmbpy)(CN)(4)](-) entity adopts a bis-monodentate coordination mode toward trans-[M(II)(H(2)O)(2)] units through two of its four cyanide groups in cis positions. 1 exhibits the magnetic behaviour of magnetically isolated six-coordinate low-spin Fe(III) complexes with an important orbital contribution. 2 behaves as ferrimagnetic Fe(III)(2)Mn(II) chains, whereas 3-5 exhibit intrachain ferromagnetic couplings between the low-spin Fe(III) and either Cu(II) (3), Ni (4) or Co(II) (5) as well as frequency-dependence of the out-of-phase ac susceptibility signals below 3.0 (3), 5.5 (4) and 5.0 K (5). The relaxation time and the energy to reverse the magnetization of 3-5 are related to the anisotropy of the M(II) center and to the intra- and interchain magnetic interactions. Unprecedentedly in the world of cyanide-bearing complexes, 5 exhibits a double slow relaxation of the magnetization.

Mechanics of biopolymer materials: Single chains to bulk properties

NARCIS (Netherlands)

Amuasi, H.E.; Storm, C.

2010-01-01

We outline the first stages in the multiscale modeling of biopolymer materials, starting with the statistical mechanics of single stiff chains. In the first coarse graining step, we demonstrate how to integrate out the single polymer degrees of freedom in supramolecular assemblies of such

Direct observation of backbone planarization via side-chain alignment in single bulky-substituted polythiophenes

Science.gov (United States)

Raithel, Dominic; Simine, Lena; Pickel, Sebastian; Schötz, Konstantin; Panzer, Fabian; Baderschneider, Sebastian; Schiefer, Daniel; Lohwasser, Ruth; Köhler, Jürgen; Thelakkat, Mukundan; Sommer, Michael; Köhler, Anna; Rossky, Peter J.; Hildner, Richard

2018-03-01

The backbone conformation of conjugated polymers affects, to a large extent, their optical and electronic properties. The usually flexible substituents provide solubility and influence the packing behavior of conjugated polymers in films or in bad solvents. However, the role of the side chains in determining and potentially controlling the backbone conformation, and thus the optical and electronic properties on the single polymer level, is currently under debate. Here, we investigate directly the impact of the side chains by studying the bulky-substituted poly(3-(2,5-dioctylphenyl)thiophene) (PDOPT) and the common poly(3-hexylthiophene) (P3HT), both with a defined molecular weight and high regioregularity, using low-temperature single-chain photoluminescence (PL) spectroscopy and quantum-classical simulations. Surprisingly, the optical transition energy of PDOPT is significantly (˜2,000 cm‑1 or 0.25 eV) red-shifted relative to P3HT despite a higher static and dynamic disorder in the former. We ascribe this red shift to a side-chain induced backbone planarization in PDOPT, supported by temperature-dependent ensemble PL spectroscopy. Our atomistic simulations reveal that the bulkier 2,5-dioctylphenyl side chains of PDOPT adopt a clear secondary helical structural motif and thus protect conjugation, i.e., enforce backbone planarity, whereas, for P3HT, this is not the case. These different degrees of planarity in both thiophenes do not result in different conjugation lengths, which we found to be similar. It is rather the stronger electronic coupling between the repeating units in the more planar PDOPT which gives rise to the observed spectral red shift as well as to a reduced calculated electron‑hole polarization.

Selection rules for single-chain-magnet behaviour in non-collinear Ising systems

International Nuclear Information System (INIS)

Vindigni, Alessandro; Pini, Maria Gloria

2009-01-01

The magnetic behaviour of molecular single-chain magnets is investigated in the framework of a one-dimensional Ising model with single spin-flip Glauber dynamics. Opportune modifications to the original theory are required in order to account for non-collinearity of local anisotropy axes between themselves and with respect to the crystallographic (laboratory) frame. The extension of Glauber's theory to the case of a collinear Ising ferrimagnetic chain is also discussed. Within this formalism, both the dynamics of magnetization reversal in zero field and the response of the system to a weak magnetic field, oscillating in time, are studied. Depending on the experimental geometry, selection rules are found for the occurrence of slow relaxation of the magnetization at low temperatures, as well as for resonant behaviour of the a.c. susceptibility as a function of temperature at low frequencies. The present theory applies successfully to some real systems, namely Mn-, Dy- and Co-based molecular magnetic chains, showing that single-chain-magnet behaviour is not only a feature of collinear ferro- and ferrimagnetic, but also of canted antiferromagnetic chains.

Selection rules for single-chain-magnet behaviour in non-collinear Ising systems

Energy Technology Data Exchange (ETDEWEB)

Vindigni, Alessandro [Laboratorium fuer Festkoerperphysik, ETH Zuerich, CH-8093 Zuerich (Switzerland); Pini, Maria Gloria [Istituto dei Sistemi Complessi, Consiglio Nazionale delle Ricerche, Via Madonna del Piano 10, I-50019 Sesto Fiorentino (Italy)], E-mail: vindigni@phys.ethz.ch

2009-06-10

The magnetic behaviour of molecular single-chain magnets is investigated in the framework of a one-dimensional Ising model with single spin-flip Glauber dynamics. Opportune modifications to the original theory are required in order to account for non-collinearity of local anisotropy axes between themselves and with respect to the crystallographic (laboratory) frame. The extension of Glauber's theory to the case of a collinear Ising ferrimagnetic chain is also discussed. Within this formalism, both the dynamics of magnetization reversal in zero field and the response of the system to a weak magnetic field, oscillating in time, are studied. Depending on the experimental geometry, selection rules are found for the occurrence of slow relaxation of the magnetization at low temperatures, as well as for resonant behaviour of the a.c. susceptibility as a function of temperature at low frequencies. The present theory applies successfully to some real systems, namely Mn-, Dy- and Co-based molecular magnetic chains, showing that single-chain-magnet behaviour is not only a feature of collinear ferro- and ferrimagnetic, but also of canted antiferromagnetic chains.

Covalent bond force profile and cleavage in a single polymer chain

Science.gov (United States)

Garnier, Lionel; Gauthier-Manuel, Bernard; van der Vegte, Eric W.; Snijders, Jaap; Hadziioannou, Georges

2000-08-01

We present here the measurement of the single-polymer entropic elasticity and the single covalent bond force profile, probed with two types of atomic force microscopes (AFM) on a synthetic polymer molecule: polymethacrylic acid in water. The conventional AFM allowed us to distinguish two types of interactions present in this system when doing force spectroscopic measurements: the first interaction is associated with adsorption sites of the polymer chains onto a bare gold surface, the second interaction is directly correlated to the rupture process of a single covalent bond. All these bridging interactions allowed us to stretch the single polymer chain and to determine the various factors playing a role in the elasticity of these molecules. To obtain a closer insight into the bond rupture process, we moved to a force sensor stable in position when measuring attractive forces. By optimizing the polymer length so as to fulfill the elastic stability conditions, we were able for the first time to map out the entire force profile associated with the cleavage of a single covalent bond. Experimental data coupled with molecular quantum mechanical calculations strongly suggest that the breaking bond is located at one end of the polymer chain.

Exploring single chain amphiphile self-assembly and their possible roles in light transduction

DEFF Research Database (Denmark)

Monnard, Pierre-Alain

2011-01-01

Self-assembled structures of single-chain amphiphiles have been used as hosts for biochemical, and chemical reactions. Their use as models for protocells (i.e., precursors to the first biological cells) has been extensively researched by various groups because the availability of single chain......: the medium composition in terms of ionic strengths and the medium physical parameters, such as temperature, significantly influence the formation of structures, as well as their subsequent stability. In addition, membranes composed of a single amphiphile type seem to be implausible as no potential amphiphile...... source studied to date can supply one single type of amphiphile at concentrations conducive to self-assembly. Mixtures of single-chain amphiphiles were therefore proposed to better model primitive membranes and potentially enhance their structural integrity1-3. Recently, we have established that complex...

Real-time observation of conformational switching in single conjugated polymer chains.

Science.gov (United States)

Tenopala-Carmona, Francisco; Fronk, Stephanie; Bazan, Guillermo C; Samuel, Ifor D W; Penedo, J Carlos

2018-02-01

Conjugated polymers (CPs) are an important class of organic semiconductors that combine novel optoelectronic properties with simple processing from organic solvents. It is important to study CP conformation in solution to understand the physics of these materials and because it affects the properties of solution-processed films. Single-molecule techniques are unique in their ability to extract information on a chain-to-chain basis; however, in the context of CPs, technical challenges have limited their general application to host matrices or semiliquid environments that constrain the conformational dynamics of the polymer. We introduce a conceptually different methodology that enables measurements in organic solvents using the single-end anchoring of polymer chains to avoid diffusion while preserving polymer flexibility. We explore the effect of organic solvents and show that, in addition to chain-to-chain conformational heterogeneity, collapsed and extended polymer segments can coexist within the same chain. The technique enables real-time solvent-exchange measurements, which show that anchored CP chains respond to sudden changes in solvent conditions on a subsecond time scale. Our results give an unprecedented glimpse into the mechanism of solvent-induced reorganization of CPs and can be expected to lead to a new range of techniques to investigate and conformationally manipulate CPs.

Quantum Heisenberg antiferromagnetic chains with exchange and single-ion anisotropies

International Nuclear Information System (INIS)

Peters, D; Selke, W; McCulloch, I P

2010-01-01

Using density matrix renormalization group calculations, ground state properties of the spin-1 Heisenberg chain with exchange and quadratic single-ion anisotropies in an external field are studied, for special choices of the two kinds of anisotropies. In particular, the phase diagram includes antiferromagnetic, spin-liquid (or spin-flop), IS2, and supersolid (or biconical) phases. Especially, new features of the spin-liquid and supersolid phases are discussed. Properties of the quantum chains are compared to those of corresponding classical spin chains.

Single-unit-cell layer established Bi 2 WO 6 3D hierarchical architectures: Efficient adsorption, photocatalysis and dye-sensitized photoelectrochemical performance

Energy Technology Data Exchange (ETDEWEB)

Huang, Hongwei; Cao, Ranran; Yu, Shixin; Xu, Kang; Hao, Weichang; Wang, Yonggang; Dong, Fan; Zhang, Tierui; Zhang, Yihe

2017-12-01

Single-layer catalysis sparks huge interests and gains widespread attention owing to its high activity. Simultaneously, three-dimensional (3D) hierarchical structure can afford large surface area and abundant reactive sites, contributing to high efficiency. Herein, we report an absorbing single-unit-cell layer established Bi2WO6 3D hierarchical architecture fabricated by a sodium dodecyl benzene sulfonate (SDBS)-assisted assembled strategy. The DBS- long chains can adsorb on the (Bi2O2)2+ layers and hence impede stacking of the layers, resulting in the single-unit-cell layer. We also uncovered that SDS with a shorter chain is less effective than SDBS. Due to the sufficient exposure of surface O atoms, single-unit-cell layer 3D Bi2WO6 shows strong selectivity for adsorption on multiform organic dyes with different charges. Remarkably, the single-unit-cell layer 3D Bi2WO6 casts profoundly enhanced photodegradation activity and especially a superior photocatalytic H2 evolution rate, which is 14-fold increase in contrast to the bulk Bi2WO6. Systematic photoelectrochemical characterizations disclose that the substantially elevated carrier density and charge separation efficiency take responsibility for the strengthened photocatalytic performance. Additionally, the possibility of single-unit-cell layer 3D Bi2WO6 as dye-sensitized solar cells (DSSC) has also been attempted and it was manifested to be a promising dye-sensitized photoanode for oxygen evolution reaction (ORR). Our work not only furnish an insight into designing single-layer assembled 3D hierarchical architecture, but also offer a multi-functional material for environmental and energy applications.

Force Spectroscopy of Hyaluronan by AFM; From H-bonded Networks Towards Single Chain Behavior

NARCIS (Netherlands)

Giannotti, M.I.; Rinaudo, Marguerite; Vancso, Gyula J.

2007-01-01

The conformational behavior of hyaluronan (HA) polysaccharide chains in aqueous NaCl solution was characterized directly at the single-molecule level. This comunication reports on one of the first single-chain atomic force microscopy (AFM) experiments performed at variable temperatures,

Production of a phage-displayed single chain variable fragment ...

African Journals Online (AJOL)

Abstract. Purpose: To develop specific single chain variable fragments (scFv) against ... libraries. The binding ability of the selected scFv antibody fragments against the IBDV particles was ..... Hermelink H, Koscielniak E. A human recombinant.

Intramolecular structures in a single copolymer chain consisting of flexible and semiflexible blocks: Monte Carlo simulation of a lattice model

International Nuclear Information System (INIS)

Martemyanova, Julia A; Ivanov, Victor A; Paul, Wolfgang

2014-01-01

We study conformational properties of a single multiblock copolymer chain consisting of flexible and semiflexible blocks. Monomer units of different blocks are equivalent in the sense of the volume interaction potential, but the intramolecular bending potential between successive bonds along the chain is different. We consider a single flexible-semiflexible regular multiblock copolymer chain with equal content of flexible and semiflexible units and vary the length of the blocks and the stiffness parameter. We perform flat histogram type Monte Carlo simulations based on the Wang-Landau approach and employ the bond fluctuation lattice model. We present here our data on different non-trivial globular morphologies which we have obtained in our model for different values of the block length and the stiffness parameter. We demonstrate that the collapse can occur in one or in two stages depending on the values of both these parameters and discuss the role of the inhomogeneity of intraglobular distributions of monomer units of both flexible and semiflexible blocks. For short block length and/or large stiffness the collapse occurs in two stages, because it goes through intermediate (meta-)stable structures, like a dumbbell shaped conformation. In such conformations the semiflexible blocks form a cylinder-like core, and the flexible blocks form two domains at both ends of such a cylinder. For long block length and/or small stiffness the collapse occurs in one stage, and in typical conformations the flexible blocks form a spherical core of a globule while the semiflexible blocks are located on the surface and wrap around this core.

Pressure effects on single chain magnets

Energy Technology Data Exchange (ETDEWEB)

Mito, M. E-mail: mitoh@elcs.kyutech.ac.jp; Shindo, N.; Tajiri, T.; Deguchi, H.; Takagi, S.; Miyasaka, H.; Yamashita, M.; Clerac, R.; Coulon, C

2004-05-01

Pressure effects on a single chain magnet [Mn{sub 2}(saltmen){sub 2}Ni(pao){sub 2}(py){sub 2}](ClO{sub 4}){sub 2} (saltmen{sup 2-}=N,N'-(1,1,2,2-tetramethylethylene)bis(salicylideneiminate), and pao{sup -}=pyridine-2-aldoximate) have been investigated through AC magnetic measurements under pressure (P). The slow relaxation of the magnetization depends on pressure. Both the blocking temperature (T{sub B}) and energy barrier ({delta}) increase by pressurization, and those enhancements saturate at around P=7 kbar.

76 FR 41525 - Hewlett Packard Global Parts Supply Chain, Global Product Life Cycles Management Unit Including...

Science.gov (United States)

2011-07-14

... Parts Supply Chain, Global Product Life Cycles Management Unit Including Teleworkers Reporting to... workers of Hewlett Packard, Global Parts Supply Chain, Global Product Life Cycles Management Unit...). Since eligible workers of Hewlett Packard, Global Parts Supply Chain, Global Product Life Cycles...

Excitation of random intense single-cycle light-pulse chains in optical fiber

International Nuclear Information System (INIS)

Ding, Y C; Zhang, F L; Gao, J B; Chen, Z Y; Lin, C Y; Yu, M Y

2014-01-01

Excitation of intense periodic single-cycle light pulses in a stochastic background arising from continuous wave stimulated Brillouin scattering (SBS) in a long optical fiber with weak optical feedback is found experimentally and modeled theoretically. Such intense light-pulse chains occur randomly and the optical feedback is a requirement for their excitation. The probability of these forms, among the large number of experimental output signals with identifiable waveforms, appearing is only about 3%, with the remainder exhibiting regular SBS characteristics. It is also found that pulses with low period numbers appear more frequently and the probability distribution for their occurrence in terms of the pulse power is roughly L-shaped, like that for rogue waves. The results from a three-wave-coupling model for SBS including feedback phase control agree well qualitatively with the observed phenomena. (paper)

Earlinet single calculus chain: new products overview

Science.gov (United States)

D'Amico, Giuseppe; Mattis, Ina; Binietoglou, Ioannis; Baars, Holger; Mona, Lucia; Amato, Francesco; Kokkalis, Panos; Rodríguez-Gómez, Alejandro; Soupiona, Ourania; Kalliopi-Artemis, Voudouri

2018-04-01

The Single Calculus Chain (SCC) is an automatic and flexible tool to analyze raw lidar data using EARLINET quality assured retrieval algorithms. It has been already demonstrated the SCC can retrieve reliable aerosol backscatter and extinction coefficient profiles for different lidar systems. In this paper we provide an overview of new SCC products like particle linear depolarization ratio, cloud masking, aerosol layering allowing relevant improvements in the atmospheric aerosol characterization.

Population pharmacokinetics of recombinant coagulation factor VIII-SingleChain in patients with severe hemophilia A.

Science.gov (United States)

Zhang, Y; Roberts, J; Tortorici, M; Veldman, A; St Ledger, K; Feussner, A; Sidhu, J

2017-06-01

Essentials rVIII-SingleChain is a unique recombinant factor VIII (FVIII) molecule. A population pharmacokinetic model was based on FVIII activity of severe hemophilia A patients. The model was used to simulate factor VIII activity-time profiles for various dosing scenarios. The model supports prolonged dosing of rVIII-SingleChain with intervals of up to twice per week. Background Single-chain recombinant coagulation factor VIII (rVIII-SingleChain) is a unique recombinant coagulation factor VIII molecule. Objectives To: (i) characterize the population pharmacokinetics (PK) of rVIII-SingleChain in patients with severe hemophilia A; (ii) identify correlates of variability in rVIII-SingleChain PK; and (iii) simulate various dosing scenarios of rVIII-SingleChain. Patients/Methods A population PK model was developed, based on FVIII activity levels of 130 patients with severe hemophilia A (n = 91 for ≥ 12-65 years; n = 39 for  85% and > 93% of patients were predicted to maintain FVIII activity level above 1 IU dL -1 , at all times with three-times-weekly dosing (given on days 0, 2, and 4.5) at the lowest (20 IU kg -1 ) and highest (50 IU kg -1 ) doses, respectively. For twice weekly dosing (days 0 and 3.5) of 50 IU kg -1 rVIII-SingleChain, 62-80% of patients across all ages were predicted to maintain a FVIII activity level above 1 IU dL -1 at day 7. Conclusions The population PK model adequately characterized rVIII-SingleChain PK, and the model can be utilized to simulate FVIII activity-time profiles for various dosing scenarios. © 2017 The Authors. Journal of Thrombosis and Haemostasis published by Wiley Periodicals, Inc. on behalf of International Society on Thrombosis and Haemostasis.

Versatile lanthanide-azide complexes with azide/carboxylate/hydroxy mixed bridged chain exhibiting magnetic and luminescent properties

International Nuclear Information System (INIS)

Wang Haichao; Xue Min; Guo Qian; Zhao Jiongpeng; Liu Fuchen; Ribas, Joan

2012-01-01

Two new lanthanide-azide complexes, [Ln 2 (N 3 )(isonic) 2 (OH) 3 (Hisonic)(H 2 O)] n (Ln=Yb for 1 and Tb for 2, isonic=isonicotinate), were obtained in hydrothermal condition. X-ray diffraction analysis indicated the two complexes are isomorphic chain structure in which the Ln III ions are mixed bridged by the azide anions, hydroxyl anions and carboxylate groups of the isonicotinate ligands. Further studies indicated weak antiferromagnetic interactions between the Ln III ions in 1 and 2, and complex 2 exhibit green sensitized Luminescent character of Tb III ion. - Graphical abstract: Two new 1D lanthanide-azide complexes, [Ln 2 (N 3 )(isonic) 2 (OH) 3 (Hisonic)(H 2 O)] n (Ln=Yb III for 1 and Tb III for 2, isonic=isonicotinate), were synthesized by hydrothermal reaction and exhibit interesting magnetism and fluorescence properties. Highlights: ► The research provided a new method for synthesizing lanthanide-azide complexes. ► The complexes have an interesting azide/hydroxyl/carboxylate mixed bridged1D chain structure. ► The antiferromagnetic coupling between the complexes and 2 displays green luminescence.

An Analysis of United States Marine Corps Enlisted Entry-Level Training Using Supply Chain and Operations Management

Science.gov (United States)

2010-12-01

An Analysis of United States Marine Corps Enlisted Entry-Level Training Using Supply Chain and Operations Management ______________________________________ By...Report 4. TITLE AND SUBTITLE: An Analysis of United States Marine Corps Enlisted Entry-Level Training Using Supply Chain and Operations Management 6...Level Training; United States Marine Corps; Operations Management ; Supply Chain Management; Process Analysis 16. PRICE CODE 17. SECURITY

Molecular dynamics simulation of AFM studies of a single polymer chain

International Nuclear Information System (INIS)

Wang Wenhai; Kistler, Kurt A.; Sadeghipour, Keya; Baran, George

2008-01-01

Single polymer chain force-extension behavior measured by Atomic Force Microscopy (AFM) was interpreted by molecular dynamics (MD) simulation performed by applying a bead-spring (coarse-graining) model in which the bond potential function between adjacent beads is described by a worm-like chain (WLC) model. Simulation results indicate that caution should be applied when interpreting experimental AFM data, because the data vary depending on the point of AFM tip-polymer chain attachment. This approach offers an effective way for eventual analysis of the mechanical behavior of complex polymer networks

Molecular dynamics simulation of AFM studies of a single polymer chain

Energy Technology Data Exchange (ETDEWEB)

Wang Wenhai [Center for Bioengineering and Biomaterials, College of Engineering, Temple University, 1947 N. 12th Street, Philadelphia, PA 19122 (United States); Kistler, Kurt A. [Department of Chemistry, Temple University, 1901 N. 13th Street, Philadelphia, PA 19122 (United States); Sadeghipour, Keya [Center for Bioengineering and Biomaterials, College of Engineering, Temple University, 1947 N. 12th Street, Philadelphia, PA 19122 (United States); Baran, George [Center for Bioengineering and Biomaterials, College of Engineering, Temple University, 1947 N. 12th Street, Philadelphia, PA 19122 (United States)], E-mail: grbaran@temple.edu

2008-11-24

Single polymer chain force-extension behavior measured by Atomic Force Microscopy (AFM) was interpreted by molecular dynamics (MD) simulation performed by applying a bead-spring (coarse-graining) model in which the bond potential function between adjacent beads is described by a worm-like chain (WLC) model. Simulation results indicate that caution should be applied when interpreting experimental AFM data, because the data vary depending on the point of AFM tip-polymer chain attachment. This approach offers an effective way for eventual analysis of the mechanical behavior of complex polymer networks.

White Polymer Light-Emitting Diodes Based on Exciplex Electroluminescence from Polymer Blends and a Single Polymer.

Science.gov (United States)

Liang, Junfei; Zhao, Sen; Jiang, Xiao-Fang; Guo, Ting; Yip, Hin-Lap; Ying, Lei; Huang, Fei; Yang, Wei; Cao, Yong

2016-03-09

In this Article, we designed and synthesized a series of polyfluorene derivatives, which consist of the electron-rich 4,4'-(9-alkyl-carbazole-3,6-diyl)bis(N,N-diphenylaniline) (TPA-Cz) in the side chain and the electron-deficient dibenzothiophene-5,5-dioxide (SO) unit in the main chain. The resulting copolymer PF-T25 that did not comprise the SO unit exhibited blue light-emission with the Commission Internationale de L'Eclairage coordinates of (0.16, 0.10). However, by physically blending PF-T25 with a blue light-emitting SO-based oligomer, a novel low-energy emission correlated to exciplex emerged due to the appropriate energy level alignment of TPA-Cz and the SO-based oligomers, which showed extended exciton lifetime as confirmed by time-resolved photoluminescent spectroscopy. The low-energy emission was also identified in copolymers consisting of SO unit in the main chain, which can effectively compensate for the high-energy emission to produce binary white light-emission. Polymer light-emitting diodes based on the exciplex-type single greenish-white polymer exhibit the peak luminous efficiency of 2.34 cd A(-1) and the maximum brightness of 12 410 cd m(-2), with Commission Internationale de L'Eclairage color coordinates (0.27, 0.39). The device based on such polymer showed much better electroluminescent stability than those based on blending films. These observations indicated that developing a single polymer with the generated exciplex emission can be a novel and effective molecular design strategy toward highly stable and efficient white polymer light-emitting diodes.

Electronic structures and band gaps of chains and sheets based on phenylacetylene units

International Nuclear Information System (INIS)

Kondo, Masakazu; Nozaki, Daijiro; Tachibana, Masamitsu; Yumura, Takashi; Yoshizawa, Kazunari

2005-01-01

We investigate the electronic structures of polymers composed of π-conjugated phenylacetylene (PA) units, m-PA-based and p-PA-based wires, at the extended Hueckel level of theory. It is demonstrated that these conjugated systems should have a variety of electric conductance. All of the one-dimensional (1D) chains and the two-dimensional (2D) sheet based on the m-PA unit are insulators with large band gaps of 2.56 eV because there is no effective orbital interaction with neighboring chains. On the other hand, p-PA-based 1D chains have relatively small band gaps that decrease with an increase in chain width (1.17-1.74 eV) and are semiconductive. The p-PA-based sheet called 'graphyne', a 2D-limit of the p-PA-based 1D chains, shows a small band gap of 0.89 eV. The variety of band electronic structures is discussed in terms of frontier crystal orbitals

Single-Molecule Imaging Reveals Topology Dependent Mutual Relaxation of Polymer Chains

KAUST Repository

Abadi, Maram; Serag, Maged F.; Habuchi, Satoshi

2015-01-01

The motion and relaxation of linear and cyclic polymers under entangled conditions are investigated by means of a newly developed single-molecule tracking technique, cumulative-area (CA) tracking. CA tracking enables simultaneous quantitative characterization of the diffusion mode, diffusion rate, and relaxation time that have been impossible with a widely used conventional single-molecule localization and tracking method, by analyzing cumulative areas occupied by the moving molecule. Using the novel approach, we investigate the motion and relaxation of entangled cyclic polymers, which have been an important but poorly understood question. Fluorescently labeled 42 kbp linear or cyclic tracer dsDNAs in concentrated solutions of unlabeled linear or cyclic DNAs are used as model systems. We show that CA tracking can explicitly distinguish topology-dependent diffusion mode, rate, and relaxation time, demonstrating that the method provides an invaluable tool for characterizing topological interaction between the entangled chains. We further demonstrate that the current models proposed for the entanglement between cyclic polymers which are based on cyclic chains moving through an array of fixed obstacles cannot correctly describe the motion of the cyclic chain under the entangled conditions. Our results rather suggest the mutual relaxation of the cyclic chains, which underscore the necessity of developing a new model to describe the motion of cyclic polymer under the entangled conditions based on the mutual interaction of the chains.

Single-Molecule Imaging Reveals Topology Dependent Mutual Relaxation of Polymer Chains

KAUST Repository

Abadi, Maram

2015-08-24

The motion and relaxation of linear and cyclic polymers under entangled conditions are investigated by means of a newly developed single-molecule tracking technique, cumulative-area (CA) tracking. CA tracking enables simultaneous quantitative characterization of the diffusion mode, diffusion rate, and relaxation time that have been impossible with a widely used conventional single-molecule localization and tracking method, by analyzing cumulative areas occupied by the moving molecule. Using the novel approach, we investigate the motion and relaxation of entangled cyclic polymers, which have been an important but poorly understood question. Fluorescently labeled 42 kbp linear or cyclic tracer dsDNAs in concentrated solutions of unlabeled linear or cyclic DNAs are used as model systems. We show that CA tracking can explicitly distinguish topology-dependent diffusion mode, rate, and relaxation time, demonstrating that the method provides an invaluable tool for characterizing topological interaction between the entangled chains. We further demonstrate that the current models proposed for the entanglement between cyclic polymers which are based on cyclic chains moving through an array of fixed obstacles cannot correctly describe the motion of the cyclic chain under the entangled conditions. Our results rather suggest the mutual relaxation of the cyclic chains, which underscore the necessity of developing a new model to describe the motion of cyclic polymer under the entangled conditions based on the mutual interaction of the chains.

Production of a phage-displayed single chain variable fragment ...

African Journals Online (AJOL)

Purpose: To develop specific single chain variable fragments (scFv) against infectious bursal disease virus (IBDV) via phage display technology. Methods: Purified viruses were initially applied for iterative panning rounds of scFv phage display libraries. The binding ability of the selected scFv antibody fragments against the ...

Expression, production and renaturation of a functional single-chain ...

African Journals Online (AJOL)

The single-chain variable antibody fragment (scFv) against human intercellular adhesion molecule-1 (ICAM-1) was expressed at a high level in Escherichia coli as inclusion bodies. We attempted to refold the scFv by ion-exchange chromatography (IEC), dialysis and dilution. The results show that the column ...

Single-Chain Conformation for Interacting Poly(N-isopropylacrylamide in Aqueous Solution

Directory of Open Access Journals (Sweden)

Boualem Hammouda

2015-04-01

Full Text Available The demixing phase behavior of Poly(N-isopropylacrylamide (PNIPAM aqueous solution is investigated using small-angle neutron scattering. This polymer phase separates upon heating and demixes around 32 °C. The pre-transition temperature range is characterized by two scattering modes; a low-Q (large-scale signal and a high-Q dissolved chains signal. In order to get insight into this pre-transition region, especially the origin of the low-Q (large-scale structure, the zero average contrast method is used in order to isolate single-chain conformations even in the demixing polymers transition region. This method consists of measuring deuterated and non-deuterated polymers dissolved in mixtures of deuterated and non-deuterated water for which the polymer scattering length density matches the solvent scattering length density. A fixed 4% polymer mass fraction is used in a contrast variation series where the d-water/h-water fraction is varied in order to determine the match point. The zero average contrast (match point sample displays pure single-chain scattering with no interchain contributions. Our measurements prove that the large scale structure in this polymer solution is due to a transient polymer network formed through hydrophobic segment-segment interactions. Scattering intensity increases when the temperature gets close to the phase boundary. While the apparent radius of gyration increases substantially at the Lower Critical Solution Temperature (LCST transition due to strong interchain correlation, the single-chain true radius of gyration has been found to decrease slightly with temperature when approaching the transition.

Single-molecule study on polymer diffusion in a melt state: Effect of chain topology

KAUST Repository

Habuchi, Satoshi

2013-08-06

We report a new methodology for studying diffusion of individual polymer chains in a melt state, with special emphasis on the effect of chain topology. A perylene diimide fluorophore was incorporated into the linear and cyclic poly(THF)s, and real-time diffusion behavior of individual chains in a melt of linear poly(THF) was measured by means of a single-molecule fluorescence imaging technique. The combination of mean squared displacement (MSD) and cumulative distribution function (CDF) analysis demonstrated the broad distribution of diffusion coefficient of both the linear and cyclic polymer chains in the melt state. This indicates the presence of spatiotemporal heterogeneity of the polymer diffusion which occurs at much larger time and length scales than those expected from the current polymer physics theory. We further demonstrated that the cyclic chains showed marginally slower diffusion in comparison with the linear counterparts, to suggest the effective suppression of the translocation through the threading-entanglement with the linear matrix chains. This coincides with the higher activation energy for the diffusion of the cyclic chains than of the linear chains. These results suggest that the single-molecule imaging technique provides a powerful tool to analyze complicated polymer dynamics and contributes to the molecular level understanding of the chain interaction. © 2013 American Chemical Society.

Single-molecule study on polymer diffusion in a melt state: Effect of chain topology

KAUST Repository

Habuchi, Satoshi; Fujiwara, Susumu; Yamamoto, Takuya; Vá cha, Martin; Tezuka, Yasuyuki

2013-01-01

We report a new methodology for studying diffusion of individual polymer chains in a melt state, with special emphasis on the effect of chain topology. A perylene diimide fluorophore was incorporated into the linear and cyclic poly(THF)s, and real-time diffusion behavior of individual chains in a melt of linear poly(THF) was measured by means of a single-molecule fluorescence imaging technique. The combination of mean squared displacement (MSD) and cumulative distribution function (CDF) analysis demonstrated the broad distribution of diffusion coefficient of both the linear and cyclic polymer chains in the melt state. This indicates the presence of spatiotemporal heterogeneity of the polymer diffusion which occurs at much larger time and length scales than those expected from the current polymer physics theory. We further demonstrated that the cyclic chains showed marginally slower diffusion in comparison with the linear counterparts, to suggest the effective suppression of the translocation through the threading-entanglement with the linear matrix chains. This coincides with the higher activation energy for the diffusion of the cyclic chains than of the linear chains. These results suggest that the single-molecule imaging technique provides a powerful tool to analyze complicated polymer dynamics and contributes to the molecular level understanding of the chain interaction. © 2013 American Chemical Society.

Single-chain magnet features in 1D [MnR4TPP][TCNE] compounds

International Nuclear Information System (INIS)

Balanda, Maria; Tomkowicz, Zbigniew; Rams, Michal; Haase, Wolfgang

2011-01-01

Molecular chains of antiferrimagnetically coupled Mn III -ion (S = 2) and TCNE (tetracyanoethylene) radical moments (s = 1/2 ) show different behaviour depending on group R substituted to TPP (tetraphenylporphyrin) and on the substitution site. The compound with R = F in Ortho position is a Single-Chain Magnet (SCM) with blocking temperature T b = 6.6K, while that with R = F in Meta position shows both blocking (T b = 5.4 K) and magnetic ordering transition (T c = 10 K). For bulky groups R = OC n H 2n+1 , the magnetically ordered phase is observed (T c ∼ 22 K), which does not however prevent slow relaxation at T c of 2 T at 2.3 K is like that of SCM. The frequency dependent AC susceptibility in the superimposed DC field reveals common features of all systems. The energy of intrachain ferromagnetic coupling between effective spin units 3/2, relevant at low temperatures, is determined for all compounds and the interchain dipolar coupling is estimated. It is concluded that slow relaxation is inherent for all quasi one-dimensional compounds and for the magnetically ordered ones shows up in the high enough magnetic field.

76 FR 34271 - Hewlett Packard, Global Parts Supply Chain, Global Product Life Cycles Management Unit, Including...

Science.gov (United States)

2011-06-13

... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-74,671] Hewlett Packard, Global Parts Supply Chain, Global Product Life Cycles Management Unit, Including Teleworkers Reporting to... Supply Chain, Global Product Life Cycles Management Unit, including teleworkers reporting to Houston...

Markov chain analysis of single spin flip Ising simulations

International Nuclear Information System (INIS)

Hennecke, M.

1997-01-01

The Markov processes defined by random and loop-based schemes for single spin flip attempts in Monte Carlo simulations of the 2D Ising model are investigated, by explicitly constructing their transition matrices. Their analysis reveals that loops over all lattice sites using a Metropolis-type single spin flip probability often do not define ergodic Markov chains, and have distorted dynamical properties even if they are ergodic. The transition matrices also enable a comparison of the dynamics of random versus loop spin selection and Glauber versus Metropolis probabilities

Exactly solved mixed spin-(1,1/2) Ising–Heisenberg diamond chain with a single-ion anisotropy

International Nuclear Information System (INIS)

Lisnyi, Bohdan; Strečka, Jozef

2015-01-01

The mixed spin-(1,1/2) Ising–Heisenberg diamond chain with a single-ion anisotropy is exactly solved through the generalized decoration–iteration transformation and the transfer-matrix method. The decoration–iteration transformation is first used for establishing a rigorous mapping equivalence with the corresponding spin-1 Blume–Emery–Griffiths chain, which is subsequently exactly treated within the transfer-matrix technique. Apart from three classical ground states the model exhibits three striking quantum ground states in which a singlet-dimer state of the interstitial Heisenberg spins is accompanied either with a frustrated state or a polarized state or a non-magnetic state of the nodal Ising spins. It is evidenced that two magnetization plateaus at zero and/or one-half of the saturation magnetization may appear in low-temperature magnetization curves. The specific heat may display remarkable temperature dependences with up to three and four distinct round maxima in a zero and non-zero magnetic field, respectively. - Highlights: • Mixed spin-(1,1/2) Ising–Heisenberg diamond chain is exactly solved. • Quantum ground states with a singlet-dimer state of the Heisenberg spins are found. • Magnetization curve displays intermediate plateaus at zero and half of full magnetization. • Thermal dependences of specific heat may display up to four distinct peaks

Multi-Unit Initiating Event Analysis for a Single-Unit Internal Events Level 1 PSA

Energy Technology Data Exchange (ETDEWEB)

Kim, Dong San; Park, Jin Hee; Lim, Ho Gon [KAERI, Daejeon (Korea, Republic of)

2016-05-15

The Fukushima nuclear accident in 2011 highlighted the importance of considering the risks from multi-unit accidents at a site. The ASME/ANS probabilistic risk assessment (PRA) standard also includes some requirements related to multi-unit aspects, one of which (IE-B5) is as follows: 'For multi-unit sites with shared systems, DO NOT SUBSUME multi-unit initiating events if they impact mitigation capability [1].' However, the existing single-unit PSA models do not explicitly consider multi-unit initiating events and hence systems shared by multiple units (e.g., alternate AC diesel generator) are fully credited for the single unit and ignores the need for the shared systems by other units at the same site [2]. This paper describes the results of the multi-unit initiating event (IE) analysis performed as a part of the at-power internal events Level 1 probabilistic safety assessment (PSA) for an OPR1000 single unit ('reference unit'). In this study, a multi-unit initiating event analysis for a single-unit PSA was performed, and using the results, dual-unit LOOP initiating event was added to the existing PSA model for the reference unit (OPR1000 type). Event trees were developed for dual-unit LOOP and dual-unit SBO which can be transferred from dual- unit LOOP. Moreover, CCF basic events for 5 diesel generators were modelled. In case of simultaneous SBO occurrences in both units, this study compared two different assumptions on the availability of the AAC D/G. As a result, when dual-unit LOOP initiating event was added to the existing single-unit PSA model, the total CDF increased by 1∼ 2% depending on the probability that the AAC D/G is available to a specific unit in case of simultaneous SBO in both units.

Structural and electronic properties of a single C chain doped zigzag BN nanoribbons

International Nuclear Information System (INIS)

Wu, Ping; Wang, Qianwen; Cao, Gengyu; Tang, Fuling; Huang, Min

2014-01-01

The effects of single C-chain on the stability, structural and electronic properties of zigzag BN nanoribbons (ZBNNRs) were investigated by first-principles calculations. C-chain was expected to dope at B-edge for all the ribbon widths N z considered. The band gaps of C-chain doped N z -ZBNNR are narrower than that of perfect ZBNNR due to new localized states induced by C-chain. The band gaps of N z -ZBNNR-C(n) are direct except for the case of C-chain position n=2. Band gaps of BN nanoribbons are tunable by C-chain and its position n, which may endow the potential applications of BNNR in electronics.

Well-defined single-chain polymer nanoparticles via thiol-Michael addition

NARCIS (Netherlands)

Kröger, A. Pia P.; Boonen, Roy J.E.A.; Paulusse, Jos M.J.

2017-01-01

A synthetic strategy has been developed giving facile access to well-defined single-chain polymer nanoparticles (SCNPs) from styrene-, acrylate- and methacrylate-based polymers. Random copolymers (polydispersity indices 1.10–1.15) of methyl (meth)acrylate, benzyl methacrylate or styrene containing

Chained learning architectures in a simple closed-loop behavioural context

DEFF Research Database (Denmark)

Kulvicius, Tomas; Porr, Bernd; Wörgötter, Florentin

2007-01-01

are very simple and consist of single learning unit. The current study is trying to solve this problem focusing on chained learning architectures in a simple closed-loop behavioural context. METHODS: We applied temporal sequence learning (Porr B and Wörgötter F 2006) in a closed-loop behavioural system...... where a driving robot learns to follow a line. Here for the first time we introduced two types of chained learning architectures named linear chain and honeycomb chain. We analyzed such architectures in an open and closed-loop context and compared them to the simple learning unit. CONCLUSIONS...

Single-chain statistics and the upper wave-vector cutoff in polymer blends

International Nuclear Information System (INIS)

Holyst, R.; Vilgis, T.A.

1994-01-01

We derive the equation for the single-chain correlation function in polymer blends. The chains in the incompressible blend have a radius of gyration smaller than the radius of gyration for ideal chains. The chains shrink progressively as we approach the critical temperature T c . The correction responsible for shrinking is proportional to 1/ √N , where N is the polymerization index. At T=T c and for N=1000, the size of the chain has been estimated to be 10% smaller than the size of the ideal coil. The estimate relies on the appropriate cutoff. In the limit of N→∞ the chains approach the random walk limit. Additionally, we propose in this paper a self-consistent determination of the radius of gyration and the upper wave-vector cutoff. Our model is free from any divergences such as were encountered in the previous mean-field studies; we make an estimate of the chain size at the true critical temperature and not the mean-field one

Breakwater stability with damaged single layer armour units

OpenAIRE

De Rover, R.; Verhagen, H.J.; Van den Berge, A.; Reedijk, B.

2008-01-01

The effect of single layer interlocking armour unit breakage on the hydraulic armour layer stability and potential damage progression is addressed in this paper. A 2-dimensional scale model of a rubble mound breakwater with an armour layer consisting of Xbloc armour units was tested. The residual armour layer stability with broken units was determined. The armour unit displacement and damage progression was assessed. According to the test series breakage of the single layer armour units has a...

CHAINS-PC, Decay Chain Atomic Densities

International Nuclear Information System (INIS)

1994-01-01

1 - Description of program or function: CHAINS computes the atom density of members of a single radioactive decay chain. The linearity of the Bateman equations allows tracing of interconnecting chains by manually accumulating results from separate calculations of single chains. Re-entrant loops can be treated as extensions of a single chain. Losses from the chain are also tallied. 2 - Method of solution: The Bateman equations are solved analytically using double-precision arithmetic. Poles are avoided by small alterations of the loss terms. Multigroup fluxes, cross sections, and self-shielding factors entered as input are used to compute the effective specific reaction rates. The atom densities are computed at any specified times. 3 - Restrictions on the complexity of the problem: Maxima of 100 energy groups, 100 time values, 50 members in a chain

A characteristic chondroitin sulfate trisaccharide unit with a sulfated fucose branch exhibits neurite outgrowth-promoting activity: Novel biological roles of fucosylated chondroitin sulfates isolated from the sea cucumber Apostichopus japonicus.

Science.gov (United States)

Shida, Miharu; Mikami, Tadahisa; Tamura, Jun-Ichi; Kitagawa, Hiroshi

2017-06-03

Chondroitin sulfate (CS) is a class of sulfated glycosaminoglycan (GAG) chains that consist of repeating disaccharide unit composed of glucuronic acid (GlcA) and N-acetylgalactosamine (GalNAc). CS chains are found throughout the pericellular and extracellular spaces and contribute to the formation of functional microenvironments for numerous biological events. However, their structure-function relations remain to be fully characterized. Here, a fucosylated CS (FCS) was isolated from the body wall of the sea cucumber Apostichopus japonicus. Its promotional effects on neurite outgrowth were assessed by using isolated polysaccharides and the chemically synthesized FCS trisaccharide β-D-GalNAc(4,6-O-disulfate) (1-4)[α-l-fucose (2,4-O-disulfate) (1-3)]-β-D-GlcA. FCS polysaccharides contained the E-type disaccharide unit GlcA-GalNAc(4,6-O-disulfate) as a CS major backbone structure and carried distinct sulfated fucose branches. Despite their relatively lower abundance of E unit, FCS polysaccharides exhibited neurite outgrowth-promoting activity comparable to squid cartilage-derived CS-E polysaccharides, which are characterized by their predominant E units, suggesting potential roles of the fucose branch in neurite outgrowth. Indeed, the chemically synthesized FCS trisaccharide was as effective as CS-E tetrasaccharide in stimulating neurite elongation in vitro. In conclusion, FCS trisaccharide units with 2,4-O-disulfated fucose branches may provide new insights into understanding the structure-function relations of CS chains. Copyright © 2017 Elsevier Inc. All rights reserved.

Inactivation of single-chain urokinase-type plasminogen activator by thrombin in human subjects

NARCIS (Netherlands)

Braat, E. A.; Levi, M. [=Marcel M.; Bos, R.; Haverkate, F.; Lassen, M. R.; de Maat, M. P.; Rijken, D. C.

1999-01-01

Thrombin cleaves single-chain urokinase-type plasminogen activator (scu-PA) into a virtually inactive two-chain form (tcu-PA/T), a process that may protect a blood clot from early fibrinolysis. It is not known under what circumstances tcu-PA/T can be generated in vivo. We have studied the occurrence

Primitive-path statistics of entangled polymers: mapping multi-chain simulations onto single-chain mean-field models

International Nuclear Information System (INIS)

Steenbakkers, Rudi J A; Schieber, Jay D; Tzoumanekas, Christos; Li, Ying; Liu, Wing Kam; Kröger, Martin

2014-01-01

We present a method to map the full equilibrium distribution of the primitive-path (PP) length, obtained from multi-chain simulations of polymer melts, onto a single-chain mean-field ‘target’ model. Most previous works used the Doi–Edwards tube model as a target. However, the average number of monomers per PP segment, obtained from multi-chain PP networks, has consistently shown a discrepancy of a factor of two with respect to tube-model estimates. Part of the problem is that the tube model neglects fluctuations in the lengths of PP segments, the number of entanglements per chain and the distribution of monomers among PP segments, while all these fluctuations are observed in multi-chain simulations. Here we use a recently proposed slip-link model, which includes fluctuations in all these variables as well as in the spatial positions of the entanglements. This turns out to be essential to obtain qualitative and quantitative agreement with the equilibrium PP-length distribution obtained from multi-chain simulations. By fitting this distribution, we are able to determine two of the three parameters of the model, which govern its equilibrium properties. This mapping is executed for four different linear polymers and for different molecular weights. The two parameters are found to depend on chemistry, but not on molecular weight. The model predicts a constant plateau modulus minus a correction inversely proportional to molecular weight. The value for well-entangled chains, with the parameters determined ab initio, lies in the range of experimental data for the materials investigated. (paper)

Synthesis and functionalization of dextran-based single-chain nanoparticles in aqueous media

OpenAIRE

Gracia R.; Marradi M.; Cossío U.; Benito A.; Pérez-San Vicente A.; Gómez-Vallejo V.; Grande H.-J.; Llop J.; and Loinaz I.

2017-01-01

Water-dispersible dextran-based single-chain polymer nanoparticles (SCPNs) were prepared in aqueous media and under mild conditions. Radiolabeling of the resulting biocompatible materials allowed the study of lung deposition of aqueous aerosols after intratracheal nebulization by means of single-photon emission computed tomography (SPECT), demonstrating their potential use as imaging contrast agents.

Equilibrium and stochastic resonance in finite chains of noisy bistable elements

International Nuclear Information System (INIS)

Morillo, Manuel; Gomez-Ordonez, Jose; Casado, Jose Manuel

2010-01-01

Graphical abstract: We analyze the dependence of the equilibrium distribution of a collective variable of a chain on relevant parameters including the chain size and its connectivity. We also analyze the stochastic resonance effect of the same variable. - Abstract: Using numerical simulations, we analyze equilibrium properties of finite chains of coupled noisy bistable units and their response to weak time periodic forces. Finite chains with global as well as local (nearest neighbors) coupling are considered. We focus on the study of a collective variable defined as the arithmetic mean of the variables characterizing each element of the chain. By contrast with the case of infinite size chains, where the coexistence of several equilibrium distributions for the same values of parameters is possible, for finite chains just a single equilibrium distribution exists for given values of the parameters. We demonstrate that, regardless of the chain connectivity, there exist transition lines separating regions in parameter space where the equilibrium distribution function is either monomodal or multimodal. The location of the transition line depends on the chain connectivity and the size of the system. For driven chains, the response of the system shows stochastic resonant effects. For the two types of chains considered, both the power spectral amplification and the signal-to-noise ratio of the collective variable are analyzed as the noise strength, the coupling parameter and the number of bistable units in the system are varied. Compared with the effects observed in single unit systems, the collective variable shows a strong enhancement of the stochastic resonance effects.

Wave-processing of long-scale information by neuronal chains.

Directory of Open Access Journals (Sweden)

José Antonio Villacorta-Atienza

Full Text Available Investigation of mechanisms of information handling in neural assemblies involved in computational and cognitive tasks is a challenging problem. Synergetic cooperation of neurons in time domain, through synchronization of firing of multiple spatially distant neurons, has been widely spread as the main paradigm. Complementary, the brain may also employ information coding and processing in spatial dimension. Then, the result of computation depends also on the spatial distribution of long-scale information. The latter bi-dimensional alternative is notably less explored in the literature. Here, we propose and theoretically illustrate a concept of spatiotemporal representation and processing of long-scale information in laminar neural structures. We argue that relevant information may be hidden in self-sustained traveling waves of neuronal activity and then their nonlinear interaction yields efficient wave-processing of spatiotemporal information. Using as a testbed a chain of FitzHugh-Nagumo neurons, we show that the wave-processing can be achieved by incorporating into the single-neuron dynamics an additional voltage-gated membrane current. This local mechanism provides a chain of such neurons with new emergent network properties. In particular, nonlinear waves as a carrier of long-scale information exhibit a variety of functionally different regimes of interaction: from complete or asymmetric annihilation to transparent crossing. Thus neuronal chains can work as computational units performing different operations over spatiotemporal information. Exploiting complexity resonance these composite units can discard stimuli of too high or too low frequencies, while selectively compress those in the natural frequency range. We also show how neuronal chains can contextually interpret raw wave information. The same stimulus can be processed differently or identically according to the context set by a periodic wave train injected at the opposite end of the

Optimization of the crystallizability of a single-chain antibody fragment

Czech Academy of Sciences Publication Activity Database

Škerlová, Jana; Král, Vlastimil; Fábry, Milan; Sedláček, Juraj; Veverka, Václav; Řezáčová, Pavlína

2014-01-01

Roč. 70, č. 12 (2014), s. 1701-1706 ISSN 1744-3091 R&D Projects: GA MŠk(CZ) LK11205 Institutional support: RVO:61388963 ; RVO:68378050 Keywords : single-chain antibody fragment * Thermofluor assay * differential scanning fluorimetry * crystallizability optimization * oligomerization * crystallization Subject RIV: CE - Biochemistry Impact factor: 0.527, year: 2014

Choice between Single and Multiple Reinforcers in Concurrent-Chains Schedules

Science.gov (United States)

Mazur, James E.

2006-01-01

Pigeons responded on concurrent-chains schedules with equal variable-interval schedules as initial links. One terminal link delivered a single reinforcer after a fixed delay, and the other terminal link delivered either three or five reinforcers, each preceded by a fixed delay. Some conditions included a postreinforcer delay after the single…

Solvable single-species aggregation-annihilation model for chain-shaped cluster growth

International Nuclear Information System (INIS)

Ke Jianhong; Lin Zhenquan; Zheng Yizhuang; Chen Xiaoshuang; Lu Wei

2007-01-01

We propose a single-species aggregation-annihilation model, in which an aggregation reaction between two clusters produces an active cluster and an annihilation reaction produces an inert one. By means of the mean-field rate equation, we respectively investigate the kinetic scaling behaviours of three distinct systems. The results exhibit that: (i) for the general aggregation-annihilation system, the size distribution of active clusters consistently approaches the conventional scaling form; (ii) for the system with the self-degeneration of the cluster's activities, it takes the modified scaling form; and (iii) for the system with the self-closing of active clusters, it does not scale. Moreover, the size distribution of inert clusters with small size takes a power-law form, while that of large inert clusters obeys the scaling law. The results also show that all active clusters will eventually transform into inert ones and the inert clusters of any size can be produced by such an aggregation-annihilation process. This model can be used to mimic the chain-shaped cluster growth and can provide some useful predictions for the kinetic behaviour of the system

Quantum phases of AB2 fermionic chains

International Nuclear Information System (INIS)

Murcia-Correa, L S; Franco, R; Silva-Valencia, J

2016-01-01

A fermionic chain is a one-dimensional system with fermions that interact locally and can jump between sites in the lattice, in particular an AB n chain type, where A and B are sites that exhibit a difference in energy level of Δ and site B is repeated n-times, such that the unit cell has n +1 sites. A limit case of this model, called the ionic Hubbard model (n = 1), has been widely studied due to its interesting physics and applications. In this paper, we study the ground state of an AB 2 chain, which describes the material R 4 [Pt 2 (P 2 O 5 H 2 ) 4 X] · nH 2 O. Specifically, we consider a filling with two electrons per unit cell, and using the density matrix renormalization group method we found that the system exhibits the band insulator and Mott correlated insulator phases, as well as an intermediate phase between them. For couplings of Δ = 2,10 and 20, we estimate the critical points that separate these phases through the structure factor and the energy gap in the sector of charge and spin, finding that the position of the critical point rises as a function of Δ. (paper)

Strong-coupling behaviour of two t - J chains with interchain single-electron hopping

International Nuclear Information System (INIS)

Zhang Guangming; Feng Shiping; Yu Lu.

1994-01-01

Using the fermion-spin transformation to implement spin-charge separation of constrained electrons, a model of two t - J chains with interchain single-electron hopping is studied by abelian bosonization. After spin-charge decoupling the charge dynamics can be trivially solved, while the spin dynamics is determined by a strong-coupling fixed point where the correlation functions can be calculated explicitly. This is a generalization of the Luther-Emery line for two-coupled t - J chains. The interchain single-electron hopping changes the asymptotic behaviour of the interchain spin-spin correlation functions and the electron Green function, but their exponents are independent of the coupling strength. (author). 25 refs

Dynamical behavior of a single polymer chain under nanometric confinement

Science.gov (United States)

Lagrené, K.; Zanotti, J.-M.; Daoud, M.; Farago, B.; Judeinstein, P.

2010-10-01

We address the dynamical behavior of a single polymer chain under nanometric confinement. We consider a polymer melt made of a mixture of hydrogenated and deuterated high molecular mass Poly(Ethylene Oxide) (PEO). The confining material is a membrane of Anodic Aluminum Oxide (AAO), a macroscopically highly ordered confining system made of parallel cylindrical channels. We use Neutron Spin-Echo (NSE) under the Zero Average Contrast (ZAC) condition to, all at once, i) match the intense porous AAO detrimental elastic SANS (Small Angle Neutron Scattering) contribution to the total intermediate scattering function I(Q,t) and ii) measure the Q dependence of the dynamical modes of a single chain under confinement. The polymer dynamics is probed on an extremely broad spacial ([2.2 10-2 Å-1, 0.2 Å-1]) and temporal ([0.1 ns, 600 ns]) ranges. We do not detect any influence of confinement on the polymer dynamics. This result is discussed in the framework of the debate on the existence of a "corset effect" recently suggested by NMR relaxometry data.

Interfacial free energy governs single polystyrene chain collapse in water and aqueous solutions.

Science.gov (United States)

Li, Isaac T S; Walker, Gilbert C

2010-05-12

The hydrophobic interaction is significantly responsible for driving protein folding and self-assembly. To understand it, the thermodynamics, the role of water structure, the dewetting process surrounding hydrophobes, and related aspects have undergone extensive investigations. Here, we examine the hypothesis that polymer-solvent interfacial free energy is adequate to describe the energetics of the collapse of a hydrophobic homopolymer chain at fixed temperature, which serves as a much simplified model for studying the hydrophobic collapse of a protein. This implies that changes in polymer-solvent interfacial free energy should be directly proportional to the force to extend a collapsed polymer into a bad solvent. To test this hypothesis, we undertook single-molecule force spectroscopy on a collapsed, single, polystyrene chain in water-ethanol and water-salt mixtures where we measured the monomer solvation free energy from an ensemble average conformations. Different proportions within the binary mixture were used to create solvents with different interfacial free energies with polystyrene. In these mixed solvents, we observed a linear correlation between the interfacial free energy and the force required to extend the chain into solution, which is a direct measure of the solvation free energy per monomer on a single chain at room temperature. A simple analytical model compares favorably with the experimental results. This knowledge supports a common assumption that explicit water solvent may not be necessary for cases whose primary concerns are hydrophobic interactions and hydrophobic hydration.

Pricing and ordering policies for price-dependent demand in a supply chain of a single retailer and a single manufacturer

Science.gov (United States)

Kim, Jungkyu; Hong, Yushin; Kim, Taebok

2011-01-01

This article discusses joint pricing and ordering policies for price-dependent demand in a supply chain consisting of a single retailer and a single manufacturer. The retailer places orders for products according to an EOQ policy and the manufacturer produces them on a lot-for-lot basis. Four mechanisms with differing levels of coordination are presented. Mathematical models are formulated and solution procedures are developed to determine the optimal retail prices and order quantities. Through extensive numerical experiments, we analyse and compare the behaviours and characteristics of the proposed mechanisms, and find that enhancing the level of coordination has important benefits for the supply chain.

Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level

KAUST Repository

Habuchi, Satoshi

2016-09-26

We demonstrate a method for the synthesis of cyclic polymers and a protocol for characterizing their diffusive motion in a melt state at the single molecule level. An electrostatic self-assembly and covalent fixation (ESA-CF) process is used for the synthesis of the cyclic poly(tetrahydrofuran) (poly(THF)). The diffusive motion of individual cyclic polymer chains in a melt state is visualized using single molecule fluorescence imaging by incorporating a fluorophore unit in the cyclic chains. The diffusive motion of the chains is quantitatively characterized by means of a combination of mean-squared displacement (MSD) analysis and a cumulative distribution function (CDF) analysis. The cyclic polymer exhibits multiple-mode diffusion which is distinct from its linear counterpart. The results demonstrate that the diffusional heterogeneity of polymers that is often hidden behind ensemble averaging can be revealed by the efficient synthesis of the cyclic polymers using the ESA-CF process and the quantitative analysis of the diffusive motion at the single molecule level using the MSD and CDF analyses.

Enantiopure heterobimetallic single-chain magnets from the chiral Ru(III) building block.

Science.gov (United States)

Ru, Jing; Gao, Feng; Wu, Tao; Yao, Min-Xia; Li, Yi-Zhi; Zuo, Jing-Lin

2014-01-21

A pair of one-dimensional enantiomers based on the versatile chiral dicyanoruthenate(III) building block have been synthesized and they are chiral single-chain magnets with the effective spin-reversal barrier of 28.2 K.

Single-chain magnet features in 1D [MnR{sub 4}TPP][TCNE] compounds

Energy Technology Data Exchange (ETDEWEB)

Balanda, Maria [Institute of Nuclear Physics PAN, Radzikowskiego 152, 31-342 Krakow (Poland); Tomkowicz, Zbigniew; Rams, Michal [Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Krakow (Poland); Haase, Wolfgang, E-mail: Maria.Balanda@ifj.edu.pl [Institute of Physical Chemistry, Darmstadt University of Technology, 64287 Darmstadt (Germany)

2011-07-06

Molecular chains of antiferrimagnetically coupled Mn{sup III}-ion (S = 2) and TCNE (tetracyanoethylene) radical moments (s = 1/2 ) show different behaviour depending on group R substituted to TPP (tetraphenylporphyrin) and on the substitution site. The compound with R = F in Ortho position is a Single-Chain Magnet (SCM) with blocking temperature T{sub b} = 6.6K, while that with R = F in Meta position shows both blocking (T{sub b} = 5.4 K) and magnetic ordering transition (T{sub c} = 10 K). For bulky groups R = OC{sub n}H{sub 2n+1}, the magnetically ordered phase is observed (T{sub c} {approx} 22 K), which does not however prevent slow relaxation at T <8 K. Magnetic hysteresis with coercive field H{sub c} of 2 T at 2.3 K is like that of SCM. The frequency dependent AC susceptibility in the superimposed DC field reveals common features of all systems. The energy of intrachain ferromagnetic coupling between effective spin units 3/2, relevant at low temperatures, is determined for all compounds and the interchain dipolar coupling is estimated. It is concluded that slow relaxation is inherent for all quasi one-dimensional compounds and for the magnetically ordered ones shows up in the high enough magnetic field.

Systematic study of the structure of alternate pyromellitimide-PEO copolymers: Influence of the chain flexibility

International Nuclear Information System (INIS)

Djurado, David; Curtet, Jean Pierre; Bee, Marc; Michot, Christophe; Armand, Michel

2007-01-01

The structure of a family of copolyimides in which are alternating stiff/redox pyromellitimide units and flexible/solvating polyethyleneoxide (PEO) strands were studied by using wide angle and small angle X-ray scattering techniques and is fully discussed. It is shown that the rich variety of structures exhibited by these compounds can be understood by considering the dramatic change of flexibility of the chain induced by the variation of the length of the PEO strand compared to that of the pyromellimide segment. In this respect, concerning the compounds which exhibit fully amorphous structures a better understanding of their structural behavior can be obtained in the framework of Flory's theory of semi-rigid polymers. In this approach, the degree of flexibility of the chain is mainly resulting from the relative amount of flexible units constituting the repetition unit of the polymer chain. The final structural mode adopted by each compound in the solid state is then directly a consequence of this intrinsic property of the chain. The introduction of a lithium salt in contact with the copolymer chains induces some structure changes which can also be explained by the modification of the degree of flexibility of the chain. It is found that the best performances in terms of electroactivity and mixed conduction are precisely obtained with the only compound which keeps full amorphicity in absence and in presence of the lithium salt

Conformation of Single Pentablock Ionomer Chains in Dilute Solutions

Energy Technology Data Exchange (ETDEWEB)

Aryal, Dipak [Clemson Univ., SC (United States); Perahia, Dvora [Clemson Univ., SC (United States); Grest, Gary S. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2015-04-01

The conformation of single chain pentablock ionomers (A-B-C-B-A) containing randomly sulfonated polystyrene in the center block, tethered to poly-ethylene-r-propylene end-capped by poly-t-butyl styrene is studied in dilute solutions by molecular dynamics simulations. Multi-block copolymers offer a means to tailor several properties into one molecule, taking advantage of their rich phase diagram together with unique properties of specific blocks. For this pentablock the ionic block facilitates transport while the A and B components are incorporated for mechanical stability. The present study investigates the confirmation of a single chain of pentablock ionomer of molecular weight M_w ~ 50,000 g/mol and sulfonated polystyrene of the same molecular weight as that of the center block for six sulfonation fractions f from f=0.0-0.55. For the sulfonated systems Na⁺ counterions are included. Results for the equilibrium conformation of the chains and the three blocks in water and 1:1 mixture of cyclohexane and n-heptane are compared to simulations in implicit poor solvents with dielectric constants ε =1.0 and 77.73. In water, the pentablock is collapsed with sulfonated groups on the outer surface. As the sulfonation fraction f increases, the ionic, center block is increasingly segregated from the hydrophobic regions. In the 1:1 mixture of cyclohexane and heptane both the flexible and end blocks are swollen while the center ionic block is collasped for f>0, while for f=0 all blocks are swollen. In both implicit poor solvents the pentablock is collapsed into a nearly spherical shape for all f. The sodium counterions are dispersed widely throughout the simulation cell for both water and ε =77.73 whereas for ε =1.0 the counterions are largely condensed on the collapsed pentablock.

Characterization of a Single Chain Fv Antibody that Reacts with Free Morphine

Directory of Open Access Journals (Sweden)

Kazuhisa Sugimura

2013-02-01

Full Text Available An immune phage library derived from mice, hyperimmunized with morphine-conjugated BSA, was used to isolate a single-chain Fv (scFv clone, M86, with binding activity to morphine-conjugated thyroglobulin (morphine-C-Tg but not to codeine-, cocaine-, or ketamine-conjugated Tg. Surface plasmon resonance analysis using a morphine-C-Tg-coupled CM5 sensor chip showed that the Kd value was 1.26 × 10−8 M. To analyze its binding activity to free morphine and related compounds, we performed a competitive ELISA with M86 and morphine-C-Tg in the absence or presence of varying doses of free morphine and related compounds. IC50 values for opium, morphine, codeine, and heroin were 257 ng/mL, 36.4, 7.3, and 7.4 nM, respectively. Ketamine and cocaine exhibited no competitive binding activity to M86. Thus, we established a phage library-derived scFv, M86, which recognized not only free morphine and codeine as opium components but also heroin. This characteristic of M86 may be useful for developing therapeutic reagents for opiate addiction and as a free morphine-specific antibody probe.

Analysis of the paired TCR α- and β-chains of single human T cells.

Directory of Open Access Journals (Sweden)

Song-Min Kim

Full Text Available Analysis of the paired i.e. matching TCR α- and β-chain rearrangements of single human T cells is required for a precise investigation of clonal diversity, tissue distribution and specificity of protective and pathologic T-cell mediated immune responses. Here we describe a multiplex RT-PCR based technology, which for the first time allows for an unbiased analysis of the complete sequences of both α- and β-chains of TCR from single T cells. We validated our technology by the analysis of the pathologic T-cell infiltrates from tissue lesions of two T-cell mediated autoimmune diseases, psoriasis vulgaris (PV and multiple sclerosis (MS. In both disorders we could detect various T cell clones as defined by multiple T cells with identical α- and β-chain rearrangements distributed across the tissue lesions. In PV, single cell TCR analysis of lesional T cells identified clonal CD8(+ T cell expansions that predominated in the epidermis of psoriatic plaques. An MS brain lesion contained two dominant CD8(+ T-cell clones that extended over the white and grey matter and meninges. In both diseases several clonally expanded T cells carried dual TCRs composed of one Vβ and two different Vα-chain rearrangements. These results show that our technology is an efficient instrument to analyse αβ-T cell responses with single cell resolution in man. It should facilitate essential new insights into the mechanisms of protective and pathologic immunity in many human T-cell mediated conditions and allow for resurrecting functional TCRs from any αβ-T cell of choice that can be used for investigating their specificity.

Anomalous conductance oscillations and half-metallicity in atomic Ag-O chains

DEFF Research Database (Denmark)

Strange, Mikkel; Thygesen, Kristian Sommer; Sethna, James P

2008-01-01

. The conductances of the chains exhibit weak even-odd oscillations around an anomalously low value of 0.1G(0) (G(0) = 2e(2)/h) which coincide with the averaged experimental conductance in the long chain limit. The unusual conductance properties are explained in terms of a resonating-chain model, which takes...... the reflection probability and phase shift of a single bulk-chain interface as the only input. The model also explains the conductance oscillations for other metallic chains.......Using spin density functional theory, we study the electronic and magnetic properties of atomically thin, suspended chains containing silver and oxygen atoms in an alternating sequence. Chains longer than 4 atoms develop a half-metallic ground state implying fully spin-polarized charge carriers...

Oxygen vacancy chain and conductive filament formation in hafnia

Science.gov (United States)

Xue, Kan-Hao; Miao, Xiang-Shui

2018-04-01

The stability and aggregation mechanisms of oxygen vacancy chains are studied for hafnia using self-energy corrected density functional theory. While oxygen vacancies tend not to align along the c-axis of monoclinic HfO2, oxygen vacancy chains along a-axis and b-axis are energetically favorable, with cohesive energies of 0.05 eV and 0.03 eV per vacancy, respectively. Nevertheless, with an increase of the cross section area, intensive oxygen vacancy chains become much more stable in hafnia, which yields phase separation into Hf-clusters and HfO2. Compared with disperse single vacancy chains, intensive oxygen vacancy chains made of 4, 6, and 8 single vacancy chains are energetically more favorable by 0.17, 0.20, and 0.30 eV per oxygen vacancy, respectively. On the other hand, while a single oxygen vacancy chain exhibits a tiny electronic energy gap of around 0.5 eV, metallic conduction emerges for the intensive vacancy chain made of 8 single vacancy chains, which possesses a filament cross section area of ˜0.4 nm2. This sets a lower area limit for Hf-cluster filaments from metallic conduction point of view, but in real hafnia resistive RAM devices the cross section area of the filaments can generally be much larger (>5 nm2) for the sake of energy minimization. Our work sets up a bridge between oxygen vacancy ordering and phase separation in hafnia, and shows a clear trend of filament stabilization with larger dimensions. The results could explain the threshold switching phenomenon in hafnia when a small AFM tip was used as the top electrode, as well as the undesired multimode operation in resistive RAM cells with 3 nm-thick hafnia.

Synthesis, crystal structure, and magnetic properties of two-dimensional divalent metal glutarate/dipyridylamine coordination polymers, with a single crystal-to-single crystal transformation in the copper derivative

International Nuclear Information System (INIS)

Montney, Matthew R.; Supkowski, Ronald M.; Staples, Richard J.; LaDuca, Robert L.

2009-01-01

Hydrothermal reaction of divalent metal chlorides with glutaric acid and 4,4'-dipyridylamine (dpa) has afforded an isostructural family of coordination polymers with formulation [M(glu)(dpa)] n (M=Co (1), Ni (2), Cu (3); glu=glutarate). Square pyramidal coordination is seen in 1-3, with semi-ligation of a sixth donor to produce a '5+1' extended coordination sphere. Neighboring metal atoms are linked into 1D [M(glu)] n neutral chains through chelating/monodentate bridging glutarate moieties with a syn-anti binding mode, and semi-chelation of the pendant carboxylate oxygen. These chains further connect into 2D layers through dipodal dpa ligands. Neighboring layers stack into the pseudo 3D crystal structure of 1-3 through supramolecular hydrogen bonding between dpa amine units and the semi-chelated glutarate oxygen atoms. The variable temperature magnetic behavior of 1-3 was explored and modeled as infinite 1D Heisenberg chains. Notably, complex 3 undergoes a thermally induced single crystal-to-single crystal transformation between centric and acentric space groups, with a conformationally disordered unilayer structure at 293 K and an ordered bilayer structure at 173 K. All materials were further characterized via infrared spectroscopy and elemental and thermogravimetric analyses. - Graphical abstract: The coordination polymers [M(glu)(dpa)] n (M=Co (1), Ni (2), Cu (3); glu=glutarate, dpa=4,4'-dipyridylamine) exhibit 2D layer structures based on 1D [M(glu)] n chains linked through dpa tethers. Antiferromagnetic coupling is observed for 2 and 3, while ferromagnetism is predominant in 1. Compound 3 undergoes a thermally induced single crystal-to-single crystal transformation from an acentric to a centrosymmetric space group

Spin canting in a Dy-based single-chain magnet with dominant next-nearest-neighbor antiferromagnetic interactions

Science.gov (United States)

Bernot, K.; Luzon, J.; Caneschi, A.; Gatteschi, D.; Sessoli, R.; Bogani, L.; Vindigni, A.; Rettori, A.; Pini, M. G.

2009-04-01

We investigate theoretically and experimentally the static magnetic properties of single crystals of the molecular-based single-chain magnet of formula [Dy(hfac)3NIT(C6H4OPh)]∞ comprising alternating Dy3+ and organic radicals. The magnetic molar susceptibility χM displays a strong angular variation for sample rotations around two directions perpendicular to the chain axis. A peculiar inversion between maxima and minima in the angular dependence of χM occurs on increasing temperature. Using information regarding the monomeric building block as well as an ab initio estimation of the magnetic anisotropy of the Dy3+ ion, this “anisotropy-inversion” phenomenon can be assigned to weak one-dimensional ferromagnetism along the chain axis. This indicates that antiferromagnetic next-nearest-neighbor interactions between Dy3+ ions dominate, despite the large Dy-Dy separation, over the nearest-neighbor interactions between the radicals and the Dy3+ ions. Measurements of the field dependence of the magnetization, both along and perpendicularly to the chain, and of the angular dependence of χM in a strong magnetic field confirm such an interpretation. Transfer-matrix simulations of the experimental measurements are performed using a classical one-dimensional spin model with antiferromagnetic Heisenberg exchange interaction and noncollinear uniaxial single-ion anisotropies favoring a canted antiferromagnetic spin arrangement, with a net magnetic moment along the chain axis. The fine agreement obtained with experimental data provides estimates of the Hamiltonian parameters, essential for further study of the dynamics of rare-earth-based molecular chains.

Stabilization of bacterially expressed erythropoietin by single site-specific introduction of short branched PEG chains at naturally occurring glycosylation sites.

Science.gov (United States)

Hoffmann, E; Streichert, K; Nischan, N; Seitz, C; Brunner, T; Schwagerus, S; Hackenberger, C P R; Rubini, M

2016-05-24

The covalent attachment of polyethylene glycol (PEG) to therapeutic proteins can improve their physicochemical properties. In this work we utilized the non-natural amino acid p-azidophenylalanine (pAzF) in combination with the chemoselective Staudinger-phosphite reaction to install branched PEG chains to recombinant unglycosylated erythropoietin (EPO) at each single naturally occurring glycosylation site. PEGylation with two short 750 or 2000 Da PEG units at positions 24, 38, or 83 significantly decreased unspecific aggregation and proteolytic degradation while biological activity in vitro was preserved or even increased in comparison to full-glycosylated EPO. This site-specific bioconjugation approach permits to analyse the impact of PEGylation at single positions. These results represent an important step towards the engineering of site-specifically modified EPO variants from bacterial expression with increased therapeutic efficacy.

Jet and ultrasonic nebulization of single chain urokinase plasminogen activator (scu-PA)

DEFF Research Database (Denmark)

Münster, Anna-Marie; Bendstrup, E; Jensen, J.I.

2000-01-01

locally by nebulization in a recombinant zymogen form as single chain urokinase plasminogen activator (scu-PA). We aimed to characterize the particle size distribution, drug output, and enzymatic activity of scu-PA after nebulization with a Ventstream jet nebulizer (Medic-Aid, Bognor Regis, UK) and a Syst...

Finite-size effects on the static properties of a single-chain magnet

Science.gov (United States)

Bogani, L.; Sessoli, R.; Pini, M. G.; Rettori, A.; Novak, M. A.; Rosa, P.; Massi, M.; Fedi, M. E.; Giuntini, L.; Caneschi, A.; Gatteschi, D.

2005-08-01

We study the role of defects in the “single-chain magnet” CoPhOMe by inserting a controlled number of diamagnetic impurities. The samples are analyzed with unprecedented accuracy with the particle induced x-ray emission technique, and with ac and dc magnetic measurements. In an external applied field the system shows an unexpected behavior, giving rise to a double peak in the susceptibility. The static thermodynamic properties of the randomly diluted Ising chain with alternating g values are then exactly obtained via a transfer matrix approach. These results are compared to the experimental behavior of CoPhOMe, showing qualitative agreement.

Means-end chains as associative networks: Do they exhibit automatic spreading activation

DEFF Research Database (Denmark)

Scholderer, Joachim; Grunert, Klaus G.

Despite its popularity in consumer research, means-end chain theory suffers from problems of unconfirmed validity. In particular, it is unknown if its central construct, the means-end chain (MEC), is an identifiable memory structure or not. Theoretically, means-end chains can be cast as associative...... networks with a three-layered structure, consisting of attributes (A), consequences (C) and values (V) that are hierarchically linked. This yields two predictions when operationalized in a lexical decision task: means-end chains should display spreading activation (direct as well as mediated priming...

From single Debye-Hückel chains to polyelectrolyte solutions: Simulation results

Science.gov (United States)

Kremer, Kurt

1996-03-01

This lecture will present results from simulations of single weakly charged flexible chains, where the electrostatic part of the interaction is modeled by a Debye-Hückel potential,( with U. Micka, IFF, Forschungszentrum Jülich, 52425 Jülich, Germany) as well as simulations of polyelectrolyte solutions, where the counterions are explicitly taken into account( with M. J. Stevens, Sandia Nat. Lab., Albuquerque, NM 87185-1111) ( M. J. Stevens, K. Kremer, JCP 103), 1669 (1995). The first set of the simulations is meant to clear a recent contoversy on the dependency of the persistence length LP on the screening length Γ. While the analytic theories give Lp ~ Γ^x with either x=1 or x=2, the simulations find for all experimentally accessible chain lengths a varying exponent, which is significantly smaller than 1. This causes serious doubts on the applicability of this model for weakly charged polyelectrolytes in general. The second part deals with strongly charged flexible polyelectrolytes in salt free solution. These simulations are performed for multichain systems. The full Coulomb interactions of the monomers and counterions are treated explicitly. Experimental measurements of the osmotic pressure and the structure factor are reproduced and extended. The simulations reveal a new picture of the chain structure based on calculations of the structure factor, persistence length, end-to-end distance, etc. Even at very low density, the chains show significant bending. Furthermore, the chains contract significantly before they start to overlap. We also show that counterion condensation dramatically alters the chain structure, even for a good solvent backbone.

A supply chain analysis framework for assessing state-level forest biomass utilization policies in the United States

International Nuclear Information System (INIS)

Becker, Dennis R.; Moseley, Cassandra; Lee, Christine

2011-01-01

The number of state policies aimed at fostering biomass utilization has proliferated in recent years in the United States. Several states aim to increase the use of forest and agriculture biomass through renewable energy production. Several more indirectly encourage utilization by targeting aspects of the supply chain from trees standing in the forest to goods sold. This research classifies 370 state policies from across the United States that provides incentives for forest biomass utilization. We compare those policies by types of incentives relative to the supply chain and geographic clustering. We then develop a framework for policy evaluation building on the supply chain steps, which can be used to assess intended and unintended consequences of policy interactions. These findings may inform policy development and identify synergies at different steps in the supply chain to enhance forest biomass utilization.

Conductance of single microRNAs chains related to the autism spectrum disorder

Science.gov (United States)

Oliveira, J. I. N.; Albuquerque, E. L.; Fulco, U. L.; Mauriz, P. W.; Sarmento, R. G.; Caetano, E. W. S.; Freire, V. N.

2014-09-01

The charge transport properties of single-stranded microRNAs (miRNAs) chains associated to autism disorder were investigated. The computations were performed within a tight-binding model, together with a transfer matrix technique, with ionization energies and hopping parameters obtained by quantum chemistry method. Current-voltage (I× V) curves of twelve miRNA chains related to the autism spectrum disorders were calculated and analysed. We have obtained both semiconductor and insulator behavior, and a relationship between the current intensity and the autism-related miRNA bases sequencies, suggesting that a kind of electronic biosensor can be developed to distinguish different profiles of autism disorders.

Novel odd/even effect of alkylene chain length on the photopolymerizability of organogelators.

Science.gov (United States)

Aoki, Ken'ichi; Kudo, Masabumi; Tamaoki, Nobuyuki

2004-10-28

[reaction: see text] Starting from diactylene diacarboxylic acids, we have synthesized a series of photopolymerizable organogelators that possess simple amide structures, different alkylene chain lengths, and either optically active or racemic 3,7-dimethyl-1-octylamine units. The alkylene chain length of these compounds exhibits a prominent odd/even effect with respect to the photopolymerization in the gel state and is accompanied by a stereostructural effect on the gelation ability.

Trends in single women with malignancy of the uterine cervix in United States.

Science.gov (United States)

Machida, Hiroko; Blake, Erin A; Eckhardt, Sarah E; Takiuchi, Tsuyoshi; Grubbs, Brendan H; Mikami, Mikio; Roman, Lynda D; Matsuo, Koji

2018-03-01

To examine trends and characteristics of single women with malignancy of the uterine cervix. This is a retrospective observational study examining the United States population-based tumor registry (the Surveillance, Epidemiology, and End Results program). Time-specific trends in single marital status were examined in 3,294,208 women among 12 common female malignancies including 87,151 women with uterine cervical malignancy between 1973 and 2013. While the proportion of single women in the majority of malignancies increased during the study time, the proportion of single women with cervical malignancy significantly increased more than in other malignancies (29.3% in 2013 from 6.3% in 1973). There was a surge in the proportion of single women with cervical malignancy starting in the early 1990s, exhibiting the largest annual percentage rate change (APC) among all examined malignancies (1.8%; 95% confidence interval [CI]=1.6, 2.0; pwomen aged single women aged ≥40 years increased significantly during the time (APC, 2.7%; 95% CI=2.3, 3.2; psingle women with malignancy of the uterine cervix has significantly increased in the past 4 decades. This increase was most dramatic in single women aged ≥40 years. Improving screening strategies in single women aged ≥40 years may help reduce the incidence of this malignancy. Copyright © 2018. Asian Society of Gynecologic Oncology, Korean Society of Gynecologic Oncology

Linear-chain assemblies of iron oxide nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Dhak, Prasanta; Kim, Min-Kwan; Lee, Jae Hyeok; Kim, Miyoung; Kim, Sang-Koog, E-mail: sangkoog@snu.ac.kr

2017-07-01

Highlights: • Hydrothermal synthesis of pure phase 200 nm Fe{sub 3}O{sub 4} nanoparticles. • Studies of linear-chain assemblies of iron oxide nanosphere by FESEM. • Micromagnetic simulations showed the presence of 3D vortex states. • The B.E. for different numbers of particles in linear chain assemblies were calculated. - Abstract: We synthesized iron oxide nanoparticles using a simple hydrothermal approach and found several types of segments of their linear-chain self-assemblies as observed by field emission scanning electron microscopy. X-ray diffraction and transmission electron microscopy measurements confirm a well-defined single-phase FCC structure. Vibrating sample magnetometry measurements exhibit a ferromagnetic behavior. Micromagnetic numerical simulations show magnetic vortex states in the nanosphere model. Also, calculations of binding energies for different numbers of particles in the linear-chain assemblies explain a possible mechanism responsible for the self-assemblies of segments of the linear chains of nanoparticles. This work offers a step towards linear-chain self-assemblies of iron oxide nanoparticles and the effect of magnetic vortex states in individual nanoparticles on their binding energy.

Creation of Single Chain of Nanoscale Skyrmion Bubbles with Record-high Temperature Stability in a Geometrically Confined Nanostripe

KAUST Repository

Hou, Zhipeng; Zhang, Qiang; Xu, Guizhou; Gong, Chen; Ding, Bei; Wang, Yue; Li, Hang; Liu, Enke; Xu, Feng; Zhang, Hongwei; Yao, Yuan; Wu, Guangheng; Zhang, Xixiang; Wang, Wenhong

2018-01-01

Nanoscale topologically nontrivial spin textures, such as magnetic skyrmions, have been identified as promising candidates for the transport and storage of information for spintronic applications, notably magnetic racetrack memory devices. The design and realization of a single skyrmion chain at room temperature (RT) and above in the low-dimensional nanostructures are of great importance for future practical applications. Here, we report the creation of a single skyrmion bubble chain in a geometrically confined Fe3Sn2 nanostripe with a width comparable to the featured size of a skyrmion bubble. Systematic investigations on the thermal stability have revealed that the single chain of skyrmion bubbles can keep stable at temperatures varying from RT up to a record-high temperature of 630 K. This extreme stability can be ascribed to the weak temperature-dependent magnetic anisotropy and the formation of edge states at the boundaries of the nanostripes. The realization of the highly stable skyrmion bubble chain in a geometrically confined nanostructure is a very important step toward the application of skyrmion-based spintronic devices.

Creation of Single Chain of Nanoscale Skyrmion Bubbles with Record-high Temperature Stability in a Geometrically Confined Nanostripe

KAUST Repository

Hou, Zhipeng

2018-01-04

Nanoscale topologically nontrivial spin textures, such as magnetic skyrmions, have been identified as promising candidates for the transport and storage of information for spintronic applications, notably magnetic racetrack memory devices. The design and realization of a single skyrmion chain at room temperature (RT) and above in the low-dimensional nanostructures are of great importance for future practical applications. Here, we report the creation of a single skyrmion bubble chain in a geometrically confined Fe3Sn2 nanostripe with a width comparable to the featured size of a skyrmion bubble. Systematic investigations on the thermal stability have revealed that the single chain of skyrmion bubbles can keep stable at temperatures varying from RT up to a record-high temperature of 630 K. This extreme stability can be ascribed to the weak temperature-dependent magnetic anisotropy and the formation of edge states at the boundaries of the nanostripes. The realization of the highly stable skyrmion bubble chain in a geometrically confined nanostructure is a very important step toward the application of skyrmion-based spintronic devices.

Single-chain vascular endothelial growth factor variant with antagonist activity

DEFF Research Database (Denmark)

Boesen, Thomas P; Soni, Bobby; Schwartz, Thue W

2002-01-01

receptor molecules and inducing dimerization. By mixing two vascular endothelial growth factor monomers, each with different substitutions, heterodimers with only one active receptor binding site have previously been prepared. These heterodimers bind the receptor molecule but are unable to induce...... dimerization and activation. However, preparation of heterodimers is cumbersome, involving separate expression of different monomers, refolding the mixture, and separating heterodimers from homodimers. Here we show that a fully functional ligand can efficiently be expressed as a single protein chain containing...

Surface water retardation around single-chain polymeric nanoparticles: critical for catalytic function?

Science.gov (United States)

Stals, Patrick J M; Cheng, Chi-Yuan; van Beek, Lotte; Wauters, Annelies C; Palmans, Anja R A; Han, Songi; Meijer, E W

2016-03-01

A library of water-soluble dynamic single-chain polymeric nanoparticles (SCPN) was prepared using a controlled radical polymerisation technique followed by the introduction of functional groups, including probes at targeted positions. The combined tools of electron paramagnetic resonance (EPR) and Overhauser dynamic nuclear polarization (ODNP) reveal that these SCPNs have structural and surface hydration properties resembling that of enzymes.

Investments in the LNG Value Chain: A Multistage Stochastic Optimization Model focusing on Floating Liquefaction Units

OpenAIRE

Røstad, Lars Dybsjord; Erichsen, Jeanette Christine

2012-01-01

In this thesis, we have developed a strategic optimization model of investments in infrastructure in the LNG value chain. The focus is on floating LNG production units: when they are a viable solution and what value they add to the LNG value chain. First a deterministic model is presented with focus on describing the value chain, before it is expanded to a multistage stochastic model with uncertain field sizes and gas prices. The objective is to maximize expected discounted profits through op...

Experimental studies of the dynamic mechanical response of a single polymer chain

DEFF Research Database (Denmark)

Thormann, Esben; Evans, Drew R.; Craig, Vincent S. J.

2006-01-01

The high-frequency and low-amplitude dynamic mechanical response from a single poly(vinyl alcohol) chain was investigated. Modification of a commercial atomic force microscope enabled high-frequency and low-amplitude periodic deformations of polymer chains during extension to be performed...... mechanical response from poly(vinyl alcohol) does not differ from its static response. This result is not unexpected as poly(vinyl alcohol) is a highly flexible polymer with intramolecular relaxation processes taking place on a short time scale. The choice of a polymer with a fast relaxation allows its...... static properties to be recovered from the dynamic measurements and enables the method suggested in this paper for decoupling the polymer response from the hydrodynamic response to be validated....

Breakwater stability with damaged single layer armour units

NARCIS (Netherlands)

De Rover, R.; Verhagen, H.J.; Van den Berge, A.; Reedijk, B.

2008-01-01

The effect of single layer interlocking armour unit breakage on the hydraulic armour layer stability and potential damage progression is addressed in this paper. A 2-dimensional scale model of a rubble mound breakwater with an armour layer consisting of Xbloc armour units was tested. The residual

Single Chain Antibody Fragment against Venom from the Snake Daboia russelii formosensis

Directory of Open Access Journals (Sweden)

Chi-Hsin Lee

2017-10-01

Full Text Available Russell’s vipers containing hemotoxic and neurotoxic venom commonly cause snake envenomation. Horse-derived antivenom is a specific antidote, but its production is expensive and has side effects. Developing a cost-effective and more tolerable therapeutic strategy is favorable. In this study, using glutaraldehyde-attenuated Daboia russelii formosensis (DRF venom proteins to immunize chickens, polyclonal yolk-immunoglobulin (IgY antibodies were generated and showed a specific binding affinity. Phage display technology was used to generate two antibody libraries of single-chain variable fragments (scFvs containing 3.4 × 107 and 5.5 × 107 transformants, respectively. Phage-based ELISA indicated that specific clones were enriched after bio-panning. The nucleotide sequences of scFv-expressing clones were analyzed and classified into six groups in the short linker and four groups in the long linker. These scFv antibodies specifically bound to DRF proteins, but not other venom proteins. Mass spectrometric data suggested that these scFv antibodies may recognize phospholipase A2 RV-4 or RV-7. In vivo studies showed that anti-DRF IgY exhibited complete protective effects and mixed scFv antibodies increased the survival rate and time of mice challenged with a lethal dose of DRF proteins. These antibodies can be potentially applied in a rapid diagnostic method or for treatment in the future.

Single Chain Antibody Fragment against Venom from the Snake Daboia russelii formosensis.

Science.gov (United States)

Lee, Chi-Hsin; Lee, Yu-Ching; Lee, Yueh-Lun; Leu, Sy-Jye; Lin, Liang-Tzung; Chen, Chi-Ching; Chiang, Jen-Ron; Mwale, Pharaoh Fellow; Tsai, Bor-Yu; Hung, Ching-Sheng; Yang, Yi-Yuan

2017-10-27

Russell's vipers containing hemotoxic and neurotoxic venom commonly cause snake envenomation. Horse-derived antivenom is a specific antidote, but its production is expensive and has side effects. Developing a cost-effective and more tolerable therapeutic strategy is favorable. In this study, using glutaraldehyde-attenuated Daboia russelii formosensis (DRF) venom proteins to immunize chickens, polyclonal yolk-immunoglobulin (IgY) antibodies were generated and showed a specific binding affinity. Phage display technology was used to generate two antibody libraries of single-chain variable fragments (scFvs) containing 3.4 × 10⁷ and 5.5 × 10⁷ transformants, respectively. Phage-based ELISA indicated that specific clones were enriched after bio-panning. The nucleotide sequences of scFv-expressing clones were analyzed and classified into six groups in the short linker and four groups in the long linker. These scFv antibodies specifically bound to DRF proteins, but not other venom proteins. Mass spectrometric data suggested that these scFv antibodies may recognize phospholipase A2 RV-4 or RV-7. In vivo studies showed that anti-DRF IgY exhibited complete protective effects and mixed scFv antibodies increased the survival rate and time of mice challenged with a lethal dose of DRF proteins. These antibodies can be potentially applied in a rapid diagnostic method or for treatment in the future.

Synthesis, crystal structure and magnetic properties of an alternating manganese chain

International Nuclear Information System (INIS)

Ramos Silva, Manuela; Matos Beja, Ana; Antonio Paixao, Jose; Martin-Gil, Jesus

2006-01-01

A new 1D complex has been prepared and characterized. X-ray single crystal structure confirms that the Mn(II) ions assemble in alternating chains with Mn-Mn distances of 3.8432(13) and 4.4428(14) A. A 3D network of hydrogen bonds links the chains together. The temperature dependence of the magnetic susceptibility reveals that this compound undergoes a magnetic transition and exhibits an antiferromagnetic interaction in the low-temperature phase with two alternating exchange interactions of -2.32(1) and -5.55(1) cm -1 . - Graphical abstract: Portion of the dimeric manganese chain showing the two alternating exchange interactions paths

Development of double chain phosphatidylcholine functionalized polymeric monoliths for immobilized artificial membrane chromatography.

Science.gov (United States)

Wang, Qiqin; Peng, Kun; Chen, Weijia; Cao, Zhen; Zhu, Peijie; Zhao, Yumei; Wang, Yuqiang; Zhou, Haibo; Jiang, Zhengjin

2017-01-06

This study described a simple synthetic methodology for preparing biomembrane mimicking monolithic column. The suggested approach not only simplifies the preparation procedure but also improves the stability of double chain phosphatidylcholine (PC) functionalized monolithic column. The physicochemical properties of the optimized monolithic column were characterized by scanning electron microscopy, energy-dispersive X-ray spectrometry, and nano-LC. Satisfactory column permeability, efficiency, stability and reproducibility were obtained on this double chain PC functionalized monolithic column. It is worth noting that the resulting polymeric monolith exhibits great potential as a useful alternative of commercial immobilized artificial membrane (IAM) columns for in vitro predication of drug-membrane interactions. Furthermore, the comparative study of both double chain and single chain PC functionalized monoliths indicates that the presence or absence of glycerol backbone and the number of acyl chains are not decisive for the predictive ability of IAM monoliths on drug-membrane interactions. This novel PC functionalized monolithic column also exhibited good selectivity for a protein mixture and a set of pharmaceutical compounds. Copyright © 2016 Elsevier B.V. All rights reserved.

Single step, pH induced gold nanoparticle chain formation in lecithin/water system.

Science.gov (United States)

Sharma, Damyanti

2013-07-01

Gold nanoparticle (AuNP) chains have been formed by a single step method in a lecithin/water system where lecithin itself plays the role of a reductant and a template for AuNP chain formation. Two preparative strategies were explored: (1) evaporating lecithin solution with aqueous gold chloride (HAuCl4) at different pHs and (2) dispersing lecithin vesicles in aqueous HAuCl4 solutions of various pHs in the range of 2.5-11.3. In method 1, at initial pH 2.5, 20-50 nm AuNPs are found attached to lecithin vesicles. When pH is raised to 5.5 there are no vesicles present and 20 nm monodisperse particles are found aggregating. Chain formation of fine nanoparticles (3-5 nm) is observed from neutral to basic pH, between 6.5-10.3 The chains formed are hundreds of nanometers to micrometer long and are usually 2-3 nanoparticles wide. On further increasing pH to 11.3, particles form disk-like or raft-like structures. When method (ii) was used a little chain formation was observed. Most of the nanoparticles formed were found either sitting together as raft like structures or scattered on lecithin structures. Copyright © 2013 Elsevier B.V. All rights reserved.

Britain exhibition at CERN

CERN Multimedia

Bertin; CERN PhotoLab

1969-01-01

The United Kingdom inaugurated the Industrial Exhibitions in 1968, and it wasn't till 1971 that other countries staged exhibitions at CERN. This photo was taken in 1969, at the second British exhibition, where 16 companies were present.

Metal-free, single-polymer device exhibits resistive memory effect

KAUST Repository

Bhansali, Unnat Sampatraj; Khan, Yasser; Cha, Dong Kyu; Almadhoun, Mahmoud N.; Li, Ruipeng; Chen, Long; Amassian, Aram; Odeh, Ihab N.; Alshareef, Husam N.

2013-01-01

All-polymer, write-once-read-many times resistive memory devices have been fabricated on flexible substrates using a single polymer, poly(3,4- ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS). Spin-cast or inkjet-printed films of solvent-modified PEDOT:PSS are used as electrodes, while the unmodified or as-is PEDOT:PSS is used as the semiconducting active layer. The all-polymer devices exhibit an irreversible but stable transition from a low resistance state (ON) to a high resistance state (OFF) at low voltages caused by an electric-field-induced morphological rearrangement of PEDOT and PSS at the electrode interface. However, in the metal-PEDOT:PSS-metal devices, we have shown a metal filament formation switching the device from an initial high resistance state (OFF) to the low resistance state (ON). The all-PEDOT:PSS memory device has low write voltages (<3 V), high ON/OFF ratio (>10 3), good retention characteristics (>10 000 s), and stability in ambient storage (>3 months). © 2013 American Chemical Society.

Metal-free, single-polymer device exhibits resistive memory effect

KAUST Repository

Bhansali, Unnat Sampatraj

2013-12-23

All-polymer, write-once-read-many times resistive memory devices have been fabricated on flexible substrates using a single polymer, poly(3,4- ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS). Spin-cast or inkjet-printed films of solvent-modified PEDOT:PSS are used as electrodes, while the unmodified or as-is PEDOT:PSS is used as the semiconducting active layer. The all-polymer devices exhibit an irreversible but stable transition from a low resistance state (ON) to a high resistance state (OFF) at low voltages caused by an electric-field-induced morphological rearrangement of PEDOT and PSS at the electrode interface. However, in the metal-PEDOT:PSS-metal devices, we have shown a metal filament formation switching the device from an initial high resistance state (OFF) to the low resistance state (ON). The all-PEDOT:PSS memory device has low write voltages (<3 V), high ON/OFF ratio (>10 3), good retention characteristics (>10 000 s), and stability in ambient storage (>3 months). © 2013 American Chemical Society.

[Aftercare for durability and profitability of single-unit and multi-unit fixed dental prostheses

NARCIS (Netherlands)

Baat, C. de; Loveren, C. van; Maarel-Wierink, C.D. van der; Witter, D.J.; Creugers, N.H.J.

2013-01-01

An important aim ofa treatment with single-unit and multi-unit fixed dental prostheses is a durable and profitable treatment outcome. That requires aftercare, too. First, the frequency of routine oral examinations should be assessed, using an individual risk profile. The objectives of the routine

Kinetic analysis of a monoclonal therapeutic antibody and its single-chain homolog by surface plasmon resonance.

Science.gov (United States)

Patel, Rekha; Andrien, Bruce A

2010-01-01

Monoclonal antibodies (mAbs) and antibody fragments have become an emerging class of therapeutics since 1986. Their versatility enables them to be engineered for optimal efficiency and decreased immunogenicity, and the path to market has been set by recent regulatory approvals. One of the initial criteria for success of any protein or antibody therapeutic is to understand its binding characteristics to the target antigen. Surface plasmon resonance (SPR) has been widely used and is an important tool for ligand-antigen binding characterization. In this work, the binding kinetics of a recombinant mAb and its single-chain antibody homolog, single-chain variable fragment (scFv), was analyzed by SPR. These two proteins target the same antigen. The binding kinetics of the mAb (bivalent antibody) and scFv (monovalent scFv) for this antigen was analyzed along with an assessment of the thermodynamics of the binding interactions. Alternative binding configurations were investigated to evaluate potential experimental bias because theoretically experimental binding configuration should have no impact on binding kinetics. Self-association binding kinetics in the proteins' respective formulation solutions and antigen epitope mapping were also evaluated. Functional characterization of monoclonal and single-chain antibodies has become just as important as structural characterization in the biotechnology field.

Efficient sampling of reversible cross-linking polymers: Self-assembly of single-chain polymeric nanoparticles

Science.gov (United States)

Oyarzún, Bernardo; Mognetti, Bortolo Matteo

2018-03-01

We present a new simulation technique to study systems of polymers functionalized by reactive sites that bind/unbind forming reversible linkages. Functionalized polymers feature self-assembly and responsive properties that are unmatched by the systems lacking selective interactions. The scales at which the functional properties of these materials emerge are difficult to model, especially in the reversible regime where such properties result from many binding/unbinding events. This difficulty is related to large entropic barriers associated with the formation of intra-molecular loops. In this work, we present a simulation scheme that sidesteps configurational costs by dedicated Monte Carlo moves capable of binding/unbinding reactive sites in a single step. Cross-linking reactions are implemented by trial moves that reconstruct chain sections attempting, at the same time, a dimerization reaction between pairs of reactive sites. The model is parametrized by the reaction equilibrium constant of the reactive species free in solution. This quantity can be obtained by means of experiments or atomistic/quantum simulations. We use the proposed methodology to study the self-assembly of single-chain polymeric nanoparticles, starting from flexible precursors carrying regularly or randomly distributed reactive sites. We focus on understanding differences in the morphology of chain nanoparticles when linkages are reversible as compared to the well-studied case of irreversible reactions. Intriguingly, we find that the size of regularly functionalized chains, in good solvent conditions, is non-monotonous as a function of the degree of functionalization. We clarify how this result follows from excluded volume interactions and is peculiar of reversible linkages and regular functionalizations.

Size, shape, and diffusivity of a single Debye-Hückel polyelectrolyte chain in solution

Science.gov (United States)

Soysa, W. Chamath; Dünweg, B.; Prakash, J. Ravi

2015-08-01

Brownian dynamics simulations of a coarse-grained bead-spring chain model, with Debye-Hückel electrostatic interactions between the beads, are used to determine the root-mean-square end-to-end vector, the radius of gyration, and various shape functions (defined in terms of eigenvalues of the radius of gyration tensor) of a weakly charged polyelectrolyte chain in solution, in the limit of low polymer concentration. The long-time diffusivity is calculated from the mean square displacement of the centre of mass of the chain, with hydrodynamic interactions taken into account through the incorporation of the Rotne-Prager-Yamakawa tensor. Simulation results are interpreted in the light of the Odjik, Skolnick, Fixman, Khokhlov, and Khachaturian blob scaling theory (Everaers et al., Eur. Phys. J. E 8, 3 (2002)) which predicts that all solution properties are determined by just two scaling variables—the number of electrostatic blobs X and the reduced Debye screening length, Y. We identify three broad regimes, the ideal chain regime at small values of Y, the blob-pole regime at large values of Y, and the crossover regime at intermediate values of Y, within which the mean size, shape, and diffusivity exhibit characteristic behaviours. In particular, when simulation results are recast in terms of blob scaling variables, universal behaviour independent of the choice of bead-spring chain parameters, and the number of blobs X, is observed in the ideal chain regime and in much of the crossover regime, while the existence of logarithmic corrections to scaling in the blob-pole regime leads to non-universal behaviour.

Developing a global health diplomacy supply chain--a viable option for the United States to curb extremism.

Science.gov (United States)

Kumar, Sameer; Honkanen, Erik J; Karl, Chad C

2009-01-01

This study examines the idea of developing a global health diplomacy supply chain as an important foreign policy approach with the aim of improving the lives of vulnerable populations and serving the best interests of the United States. The study was based on the review of academic literature, news events, and military communiques, and historical writings were studied to determine the feasibility of the idea and the extent of costs and benefits of such an endeavor. An integrated strategic business model, supported by a medical care delivery process, was developed to create a framework for a feasible global health diplomacy supply chain. The findings indicate that extremism can be contained by creating and efficiently executing an effective supply chain to get medical care units to those that need them. The limitations are the potential exit strategies required, the tactical abilities, and diplomatic techniques needed in order to create positive diplomatic change in aid distribution. Managers must consider how supply chains will affect other organizations giving aid and the potential public response. Moreover, determining the level of care necessary to achieve the greatest positive health diplomacy continues to require vigilant scrutiny over the potential cost/benefit analysis. The analysis is valuable to policymakers considering the impacts of health diplomacy by utilizing supply chain management.

Prefrontal single-unit firing associated with deficient extinction in mice

Science.gov (United States)

Fitzgerald, Paul J; Whittle, Nigel; Flynn, Shaun M; Graybeal, Carolyn; Pinard, Courtney; Gunduz-Cinar, Ozge; Kravitz, Alexxai; Singewald, Nicolas; Holmes, Andrew

2014-01-01

The neural circuitry mediating fear extinction has been increasingly well studied and delineated. The rodent infralimbic subregion (IL) of the ventromedial prefrontal cortex (vmPFC) has been found to promote extinction, whereas the prelimbic cortex (PL) demonstrates an opposing, pro-fear, function. Studies employing in vivo electrophysiological recordings have observed that while increased IL single-unit firing and bursting predicts robust extinction retrieval, increased PL firing can correlate with sustained fear and poor extinction. These relationships between single-unit firing and extinction do not hold under all experimental conditions, however. In the current study, we further investigated the relationship between vmPFC and PL single-unit firing and extinction using inbred mouse models of intact (C57BL/6J, B6) and deficient (129S1/SvImJ, S1) extinction strains. Simultaneous single-unit recordings were made in the PL and vmPFC (encompassing IL) as B6 and S1 mice performed extinction training and retrieval. Impaired extinction retrieval in S1 mice was associated with elevated PL single-unit firing, as compared to firing in extinguishing B6 mice, consistent with the hypothesized pro-fear contribution of PL. Analysis of local field potentials also revealed significantly higher gamma power in the PL of Sthan B6 mice during extinction training and retrieval. In the vmPFC, impaired extinction in S1 mice was also associated with exaggerated single-unit firing, relative to B6 mice. This is in apparent contradiction to evidence that IL activity promotes extinction, but could reflect a (failed) compensatory effort by the vmPFC to mitigate fear-promoting activity in other regions, such as the PL or amygdala. In support of this hypothesis, augmenting IL activity via direct infusion of the GABAA receptor antagonist picrotoxin rescued impaired extinction retrieval in S1 mice. Chronic fluoxetine treatment produced modest reductions in fear during extinction retrieval and

Single-fiber myosin heavy chain polymorphism during postnatal development: modulation by hypothyroidism

Science.gov (United States)

di Maso, N. A.; Caiozzo, V. J.; Baldwin, K. M.

2000-01-01

The primary objective of this study was to follow the developmental time course of myosin heavy chain (MHC) isoform transitions in single fibers of the rodent plantaris muscle. Hypothyroidism was used in conjunction with single-fiber analyses to better describe a possible linkage between the neonatal and fast type IIB MHC isoforms during development. In contrast to the general concept that developmental MHC isoform transitions give rise to muscle fibers that express only a single MHC isoform, the single-fiber analyses revealed a very high degree of MHC polymorphism throughout postnatal development. In the adult state, MHC polymorphism was so pervasive that the rodent plantaris muscles contained approximately 12-15 different pools of fibers (i.e., fiber types). The degree of polymorphism observed at the single-fiber level made it difficult to determine specific developmental schemes analogous to those observed previously for the rodent soleus muscle. However, hypothyroidism was useful in that it confirmed a possible link between the developmental regulation of the neonatal and fast type IIB MHC isoforms.

Construction and Self-Assembly of Single-Chain Polymer Nanoparticles via Coordination Association and Electrostatic Repulsion in Water.

Science.gov (United States)

Zhu, Zhengguang; Xu, Na; Yu, Qiuping; Guo, Lei; Cao, Hui; Lu, Xinhua; Cai, Yuanli

2015-08-01

Simultaneous coordination-association and electrostatic-repulsion interactions play critical roles in the construction and stabilization of enzymatic function metal centers in water media. These interactions are promising for construction and self-assembly of artificial aqueous polymer single-chain nanoparticles (SCNPs). Herein, the construction and self-assembly of dative-bonded aqueous SCNPs are reported via simultaneous coordination-association and electrostatic-repulsion interactions within single chains of histamine-based hydrophilic block copolymer. The electrostatic-repulsion interactions are tunable through adjusting the imidazolium/imidazole ratio in response to pH, and in situ Cu(II)-coordination leads to the intramolecular association and single-chain collapse in acidic water. SCNPs are stabilized by the electrostatic repulsion of dative-bonded block and steric shielding of nonionic water-soluble block, and have a huge specific surface area of function metal centers accessible to substrates in acidic water. Moreover, SCNPs can assemble into micelles, networks, and large particles programmably in response to the solution pH. These unique media-sensitive phase-transformation behaviors provide a general, facile, and versatile platform for the fabrication of enzyme-inspired smart aqueous catalysts. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mediating Dynamic Supply Chain Formation by Collaborative Single Machine Earliness/Tardiness Agents in Supply Mesh

Directory of Open Access Journals (Sweden)

Hang Yang

2014-01-01

Full Text Available Nowadays, a trend of forming dynamic supply chains with different trading partners over different e-marketplaces has emerged. These supply chains, which are called “supply mesh,” generally refer to heterogeneous electronic marketplaces in which dynamic supply chains, as per project (often make-to-order, are formed across different parties. Conceptually, in a supply mesh a dynamic supply chain is formed vertically, mediating several companies for a project. Companies that are on the same level horizontally are either competitors or cohorts. A complex scenario such as this makes it challenging to find the right group of members for a dynamic supply chain. Earlier on, a multiagent model called the collaborative single machine earliness/tardiness (CSET model was proposed for the optimal formation of make-to-order supply chains. This paper contributes the particular agent designs, for enabling the mediation of CSET in a supply mesh, and the possibilities are discussed. It is demonstrated via a computer simulation, based on samples from the U.S. textile industry, that by using intelligent agents under the CSET model it is possible to automatically find an ideal group of trading partners from a supply mesh.

Stimulus-response functions of single avian olfactory bulb neurones.

Science.gov (United States)

McKeegan, Dorothy E F; Demmers, Theodorus G M; Wathes, Christopher M; Jones, R Bryan; Gentle, Michael J

2002-10-25

This study investigated olfactory processing in a functional context by examining the responses of single avian olfactory bulb neurones to two biologically important gases over relevant concentration ranges. Recordings of extracellular spike activity were made from 80 single units in the left olfactory bulb of 11 anaesthetised, freely breathing adult hens (Gallus domesticus). The units were spontaneously active, exhibiting widely variable firing rates (0.07-47.28 spikes/s) and variable temporal firing patterns. Single units were tested for their response to an ascending concentration series of either ammonia (2.5-100 ppm) or hydrogen sulphide (1-50 ppm), delivered directly to the olfactory epithelium. Stimulation with a calibrated gas delivery system resulted in modification of spontaneous activity causing either inhibition (47% of units) or excitation (53%) of firing. For ammonia, 20 of the 35 units tested exhibited a response, while for hydrogen sulphide, 25 of the 45 units tested were responsive. Approximate response thresholds for ammonia (median threshold 3.75 ppm (range 2.5-60 ppm, n=20)) and hydrogen sulphide (median threshold 1 ppm (range 1-10 ppm, n=25)) were determined with most units exhibiting thresholds near the lower end of these ranges. Stimulus response curves were constructed for 23 units; 16 (the most complete) were subjected to a linear regression analysis to determine whether they were best fitted by a linear, log or power function. No single function provided the best fit for all the curves (seven were linear, eight were log, one was power). These findings show that avian units respond to changes in stimulus concentration in a manner generally consistent with reported responses in mammalian olfactory bulb neurones. However, this study illustrates a level of fine-tuning to small step changes in concentration (<5 ppm) not previously demonstrated in vertebrate single olfactory bulb neurones.

First-order reversal curves of single domain particles: diluted random assemblages and chains

Science.gov (United States)

Egli, R.

2009-04-01

Exact magnetic models can be used to calculate first-order reversal curves (FORC) of single domain (SD) particle assemblages, as shown by Newell [2005] for the case of isolated Stoner-Wohlfarth particles. After overcoming experimental difficulties, a FORC diagram sharing many similarities to Newell's model has been measured on a lake sediment sample (see A.P. Chen et al., "Quantification of magnetofossils using first-order reversal curves", EGU General Assembly 2009, Abstracts Vol. 11, EGU2009-10719). This sample contains abundant magnetofossils, as shown by coercivity analysis and electron microscopy, therefore suggesting that well dispersed, intact magnetosome chains are the main SD carriers. Subtle differences between the reversible and the irreversible contributions of the measured FORC distribution suggest that magnetosome chains might not be correctly described by the Stoner-Wohlfarth model. To better understand the hysteresis properties of such chains, a simple magnetic model has been implemented, taking dipole-dipole interactions between particles within the same chain into account. The model results depend on the magnetosome elongation, the number of magnetosomes in a chain, and the gap between them. If the chain axis is subparallel to the applied field, the magnetic moment reverses by a pseudo-fanning mode, which is replaced by a pseudo-coherent rotation mode at greater angles. These reversal modes are intrinsically different from coherent rotation assumed Stoner-Wohlfarth model, resulting in FORC diagrams with a smaller reversible component. On the other hand, isolated authigenic SD particles can precipitate in the sediment matrix, as it might occur for pedogenic magnetite. In this case, an assembly of randomly located particles provides a possible model for the resulting FORC diagram. If the concentration of the particles is small, each particle is affected by a random interaction field whose statistical distribution can be calculated from first

Chain inequivalence in bovine methemoglobin. Progress report, December 1, 1979-November 30, 1980

International Nuclear Information System (INIS)

Ilan, Y.A.; Ilan, Y.; Chevion, M.; Czapski, G.

1980-01-01

Using pulse-radiolysis, a single-heme in the tetramer of bovine methemoglobin was reduced to the ferro state, producing a valence hybrid (VH). The kinetics of oxygen binding to the VH as well as the re-oxidation of the ferro-heme to the ferric state were studied as a function of pH. The kinetics of the oxygenation revealed the existence of two species, characterized by high and low affinities for oxygen that are associated with two quaternary structures (R and T, respectivey). Above pH 7.7 only the R state could be observed, while below pH 6.5 the T state was dominant. The reaction between the VH and ferricyanide at pH 7.75 (R state) consisted of two equal contributions attributed to the β and α subunits within the tetramer, respectively. At pH 6.3 (T state) a similar phenomenon was observed indicating chain inequivalences both in the T and the R states of methemoglobin. In the presence of inositol hexaphosphate, the T → R transition was shifted up by about 0.35 pH units. Yet similar rate constants exhibiting similar chain inequivalences have been measured

Efficacy and safety of rVIII-SingleChain: results of a phase 1/3 multicenter clinical trial in severe hemophilia A

Science.gov (United States)

Mahlangu, Johnny; Kuliczkowski, Kazimierz; Karim, Faraizah Abdul; Stasyshyn, Oleksandra; Kosinova, Marina V.; Lepatan, Lynda Mae; Skotnicki, Aleksander; Boggio, Lisa N.; Klamroth, Robert; Oldenburg, Johannes; Hellmann, Andrzej; Santagostino, Elena; Baker, Ross I.; Fischer, Kathelijn; Gill, Joan C.; P’Ng, Stephanie; Chowdary, Pratima; Escobar, Miguel A.; Khayat, Claudia Djambas; Rusen, Luminita; Bensen-Kennedy, Debra; Blackman, Nicole; Limsakun, Tharin; Veldman, Alex; St. Ledger, Katie

2016-01-01

Recombinant VIII (rVIII)-SingleChain is a novel B-domain–truncated recombinant factor VIII (rFVIII), comprised of covalently bonded factor VIII (FVIII) heavy and light chains. It was designed to have a higher binding affinity for von Willebrand factor (VWF). This phase 1/3 study investigated the efficacy and safety of rVIII-SingleChain in the treatment of bleeding episodes, routine prophylaxis, and surgical prophylaxis. Participants were ≥12 years of age, with severe hemophilia A (endogenous FVIII <1%). The participants were allocated by the investigator to receive rVIII-SingleChain in either an on-demand or prophylaxis regimen. Of the 175 patients meeting study eligibility criteria, 173 were treated with rVIII-SingleChain, prophylactically (N = 146) or on-demand (N = 27). The total cumulative exposure was 14 306 exposure days (EDs), with 120 participants reaching ≥50 EDs and 52 participants having ≥100 EDs. Hemostatic efficacy was rated by the investigator as excellent or good in 93.8% of the 835 bleeds treated and assessed. Across all prophylaxis regimens, the median annualized spontaneous bleeding rate was 0.00 (Q1, Q3: 0.0, 2.4) and the median overall annualized bleeding rate (ABR) was 1.14 (Q1, Q3: 0.0, 4.2). Surgical hemostasis was rated as excellent/good in 100% of major surgeries by the investigator. No participant developed FVIII inhibitors. In conclusion, rVIII-SingleChain is a novel rFVIII molecule showing excellent hemostatic efficacy in surgery and in the control of bleeding events, low ABR in patients on prophylaxis, and a favorable safety profile in this large clinical study. This trial was registered at www.clinicaltrials.gov as #NCT01486927. PMID:27330001

Quantum phase transitions driven by rhombic-type single-ion anisotropy in the S =1 Haldane chain

Science.gov (United States)

Tzeng, Yu-Chin; Onishi, Hiroaki; Okubo, Tsuyoshi; Kao, Ying-Jer

2017-08-01

The spin-1 Haldane chain is an example of the symmetry-protected-topological (SPT) phase in one dimension. Experimental realization of the spin chain materials usually involves both the uniaxial-type, D (Sz)2 , and the rhombic-type, E [(Sx)2-(Sy)2] , single-ion anisotropies. Here, we provide a precise ground-state phase diagram for a spin-1 Haldane chain with these single-ion anisotropies. Using quantum numbers, we find that the Z2 symmetry breaking phase can be characterized by double degeneracy in the entanglement spectrum. Topological quantum phase transitions take place on particular paths in the phase diagram, from the Haldane phase to the large-Ex, large-Ey, or large-D phases. The topological critical points are determined by the level spectroscopy method with a newly developed parity technique in the density matrix renormalization group [Phys. Rev. B 86, 024403 (2012), 10.1103/PhysRevB.86.024403], and the Haldane-large-D critical point is obtained with an unprecedented precision, (D/J ) c=0.9684713 (1 ) . Close to this critical point, a small rhombic single-ion anisotropy |E |/J ≪1 can destroy the Haldane phase and bring the system into a y -Néel phase. We propose that the compound [Ni (HF2) (3-Clpy ) 4] BF4 is a candidate system to search for the y -Néel phase.

Magnetic properties of CsCrCl/sub 3/, an antiferromagnetic chain compound with single-ion anisotropy

Energy Technology Data Exchange (ETDEWEB)

Day, P; Gregson, A K; Leech, D H [Oxford Univ. (UK). Inorganic Chemistry Lab.; Hutchings, M T [UKAEA Atomic Energy Research Establishment, Harwell. Materials Physics Div.; Rainford, B D [Imperial Coll. of Science and Technology, London (UK). Dept. of Physics

1979-01-01

The magnetic structure and excitations of the linear chain hexagonal perovskite salt CsCrCl/sub 3/ have been studied by susceptibility, powder and single crystal neutron diffraction, and coherent inelastic neutron scattering. Below the Neel temperature, Tsub(N) = 16 K, the spins lie in the basal plane with antiferromagnetic ordering along the c-axis chains. At 4.5 K there is strong dispersion of the spin-wave energy along c but no measurable dispersion perpendicular to c.

Safety, efficacy and pharmacokinetics of rVIII-SingleChain in children with severe hemophilia A: results of a multicenter clinical trial.

Science.gov (United States)

Stasyshyn, O; Djambas Khayat, C; Iosava, G; Ong, J; Abdul Karim, F; Fischer, K; Veldman, A; Blackman, N; St Ledger, K; Pabinger, I

2017-04-01

Essentials rVIII-SingleChain is a novel recombinant factor VIII with covalently bonded heavy and light chains. Efficacy, safety and pharmacokinetics were studied in pediatric patients with severe hemophilia A. Across all prophylaxis regimens, the median annualized spontaneous bleeding rate was 0.00. rVIII-SingleChain showed excellent hemostatic efficacy and a favorable safety profile. Background rVIII-SingleChain is a novel B-domain truncated recombinant factor VIII (rFVIII) comprised of covalently bonded FVIII heavy and light chains, demonstrating a high binding affinity to von Willebrand factor. Objectives This phase III study investigated the safety, efficacy and pharmacokinetics of rVIII-SingleChain in previously treated pediatric patients hemophilia A. Patients/Methods Patients could be assigned to prophylaxis or on-demand therapy by the investigator. For patients assigned to prophylaxis, the treatment regimen and dose were based on the bleeding phenotype. For patients receiving on-demand therapy, dosing was guided by World Federation of Hemophilia recommendations. The primary endpoint was treatment success, defined as a rating of 'excellent' or 'good' on the investigator's clinical assessment of hemostatic efficacy for all treated bleeding events. Results The study enrolled 84 patients (0 to 50 EDs. In the 347 bleeds treated and evaluated by the investigator, hemostatic efficacy was rated as excellent or good in 96.3%. The median annualized spontaneous bleeding rate was 0.00 (Q1, Q3: 0.00, 2.20), and the median annualized bleeding rate was 3.69 (Q1, Q3: 0.00, 7.20) across all prophylaxis regimens. No participant developed an inhibitor. Conclusions rVIII-SingleChain is a novel rFVIII molecule showing excellent hemostatic efficacy and a favorable safety profile in a clinical study in children hemophilia A. © 2017 The Authors. Journal of Thrombosis and Haemostasis published by Wiley Periodicals, Inc. on behalf of International Society on Thrombosis and

Conformational dynamics of Rouse chains during creep/recovery processes: a review

International Nuclear Information System (INIS)

Watanabe, Hiroshi; Inoue, Tadashi

2005-01-01

The Rouse model is a well-established model for non-entangled polymer chains and also serves as a fundamental model for entangled chains. The dynamic behaviour of this model under strain-controlled conditions has been fully analysed in the literature. However, despite the importance of the Rouse model, no analysis has been made so far of the orientational anisotropy of the Rouse eigenmodes during the stress-controlled, creep and recovery processes. For completeness of the analysis of the model, the Rouse equation of motion is solved to calculate this anisotropy for monodisperse chains and their binary blends during the creep/recovery processes. The calculation is simple and straightforward, but the result is intriguing in the sense that each Rouse eigenmode during these processes has a distribution in the retardation times. This behaviour, reflecting the interplay/correlation among the Rouse eigenmodes of different orders (and for different chains in the blends) under the constant stress condition, is quite different from the behaviour under rate-controlled flow (where each eigenmode exhibits retardation/relaxation associated with a single characteristic time). Furthermore, the calculation indicates that the Rouse chains exhibit affine deformation on sudden imposition/removal of the stress and the magnitude of this deformation is inversely proportional to the number of bond vectors per chain. In relation to these results, a difference between the creep and relaxation properties is also discussed for chains obeying multiple relaxation mechanisms (Rouse and reptation mechanisms). (topical review)

CONTRACTION CHARACTERISTICS AND MYOSIN HEAVY-CHAIN COMPOSITION OF RABBIT MASSETER MOTOR UNITS

NARCIS (Netherlands)

KWA, SHS; WEIJS, WA; JUCH, PJW

1. We studied isometric twitch peak force (TPF) and twitch contraction time (TCT) of 249 motor units of the masseter muscle in 41 rabbits after extracellular electrical stimulation of single trigeminal motoneurons in the brain stem. In 41 of these units we determined the amount of tension decrease

SINGLE CHAIN VARIABLE FRAGMENTS OF ANTIBODIES AGAINST DIPHTHERIA TOXIN B-SUBUNIT ISOLATED FROM PHAGE DISPLAY HUMAN ANTIBODY LIBRARY

Directory of Open Access Journals (Sweden)

Oliinyk O. S.

2014-02-01

Full Text Available Diphtheria toxin is an exoantigen of Corynebacterium diphtheriae that inhibits protein synthesis and kills sensitive cells. The aim of this study was to obtain human recombinant single-chain variable fragment (scFv antibodies against receptor-binding B subunit of diphtheria toxin. 12 specific clones were selected after three rounds of a phage display naїve (unimmunized human antibody library against recombinant B-subunit. scFv DNA inserts from these 12 clones were digested with MvaI, and 6 unique restriction patterns were found. Single-chain antibodies were expressed in Escherichia coli XL1-blue. The recombinant proteins were characterized by immunoblotting of bacterial extracts and detection with an anti-E-tag antibody. The toxin B-subunit-binding function of the single-chain antibody was shown by ELISA. The affinity constants for different clones were found to be from 106 to 108 М–1. Due to the fact, that these antibody fragments recognized epitopes in the receptor-binding Bsubunit of diphtheria toxin, further studies are interesting to evaluate their toxin neutralization properties and potential for therapeutic applications. Obtained scFv-antibodies can also be used for detection and investigation of biological properties of diphtheria toxin.

Luminescent, magnetic and ferroelectric properties of noncentrosymmetric chain-like complexes composed of nine-coordinate lanthanide ions.

Science.gov (United States)

Li, Xi-Li; Chen, Chun-Lai; Xiao, Hong-Ping; Wang, Ai-Ling; Liu, Cai-Ming; Zheng, Xianjun; Gao, Li-Jun; Yang, Xiao-Gang; Fang, Shao-Ming

2013-11-21

Reaction of the chiral ligand (-)-4,5-pinenepyridyl-2-pyrazine (L) with Ln(hfac)3·2H2O precursors [hfac(-) = 1,1,1,5,5,5-hexafluoroacetylacetonate, Ln = Sm(3+) (1), Eu(3+) (2), Tb(3+) (3) and Dy(3+) (4)] in methanol solution led to the formation of four noncentrosymmetric lanthanide complexes with the general formula [Ln(hfac)3L]n·H2O. The single-crystal X-ray diffraction analyses revealed that they are isostructural and take a one-dimensional (1D) chain structure based on the Ln(hfac)3L repeating units, in which the nine-coordinate Ln(3+) ions reside in a tricapped trigonal prism (TTP) environment never reported in previous 1D chain lanthanide complexes. The investigations of their photophysical properties showed that complexes 1, and 3 exhibit characteristic emissions of Sm(3+), Eu(3+) and Tb(3+) ions with respective luminescent lifetime values of 0.065, 1.066 and 0.129 ms, while complex 4 does not display any emission. The different luminescent intensities and lifetimes among them were further discussed in detail. Moreover, the magnetic properties of complexes 1-4 were assessed with a special emphasis on the Dy(3+) complex 4. Alternating-current (ac) magnetic susceptibility measurements indicated that field-induced two-step slow magnetic relaxation processes were observed in 4, indicating the single-molecule magnet (SMM) behavior of 4. In addition, the noncentrosymmetric complexes 1-4 crystallizing in the same polar point group (Cs) exhibit both ferroelectric and nonlinear optical properties at room temperature. All these features make them multifunctional crystalline molecule materials.

Monte Carlo simulated dynamical magnetization of single-chain magnets

Energy Technology Data Exchange (ETDEWEB)

Li, Jun; Liu, Bang-Gui, E-mail: bgliu@iphy.ac.cn

2015-03-15

Here, a dynamical Monte-Carlo (DMC) method is used to study temperature-dependent dynamical magnetization of famous Mn{sub 2}Ni system as typical example of single-chain magnets with strong magnetic anisotropy. Simulated magnetization curves are in good agreement with experimental results under typical temperatures and sweeping rates, and simulated coercive fields as functions of temperature are also consistent with experimental curves. Further analysis indicates that the magnetization reversal is determined by both thermal-activated effects and quantum spin tunnelings. These can help explore basic properties and applications of such important magnetic systems. - Highlights: • Monte Carlo simulated magnetization curves are in good agreement with experimental results. • Simulated coercive fields as functions of temperature are consistent with experimental results. • The magnetization reversal is understood in terms of the Monte Carlo simulations.

[Aftercare for durability and profitability of single-unit and multi-unit fixed dental prostheses].

Science.gov (United States)

de Baat, C; van Loveren, C; van der Maarel-Wierink, C D; Witter, D J; Creugers, N H J

2013-01-01

An important aim ofa treatment with single-unit and multi-unit fixed dental prostheses is a durable and profitable treatment outcome. That requires aftercare, too. First, the frequency of routine oral examinations should be assessed, using an individual risk profile. The objectives of the routine oral examinations are the prevention and, when necessary, the treatment of pathological conditions and complications. With regard to prevention, attention should be paid to information and instruction, oral biofilm and calculus, non-functional activities, hard tooth tissues, periodontal and peri-implant tissues, and saliva. Subsequently, it can be determined whether the intended durability and profitability have been achieved or can still be achieved, whether or not through indicated adjustments. Special attention should be paid to endodontically treated teeth. Restorative, repair or replacement treatments may be indicated in case ofcomplications, such as loose single- or multi-unitfixed dental prosthesis, fracture of a fixed dental prosthesis unit, lost tooth pulp vitality, tooth root fracture, and implant or implant abutment problems.

The exact solution of the Ising quantum chain with alternating single and sector defects

International Nuclear Information System (INIS)

Zhang Degang; Li Bozang; Li Yun

1992-10-01

The Ising quantum chain with alternating single and sector defects is solved exactly by using the technique of Lieb, Schultz and Mattis. The energy spectrum of this model is shown to have a tower structure if and only if these defects constitute a commensurate configuration. This means that conformal invariance is preserved under these circumstances. (author). 13 refs

Markov Tail Chains

OpenAIRE

janssen, Anja; Segers, Johan

2013-01-01

The extremes of a univariate Markov chain with regularly varying stationary marginal distribution and asymptotically linear behavior are known to exhibit a multiplicative random walk structure called the tail chain. In this paper we extend this fact to Markov chains with multivariate regularly varying marginal distributions in Rd. We analyze both the forward and the backward tail process and show that they mutually determine each other through a kind of adjoint relation. In ...

Two new Co(II)-MOFs based on polymeric chain building units: Crystal structures, and magnetic properties

Energy Technology Data Exchange (ETDEWEB)

Han, Min-Le [College of Materials & Chemical Engineering, Collaborative Innovation Center for Microgrid of New Energy of Hubei Province, China Three Gorges University, Yichang 443002 (China); Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, College of Chemistry & Materials Science, Northwest University, Xi’an 710069 (China); Wu, Ya-Pan; Zhao, Jun [College of Materials & Chemical Engineering, Collaborative Innovation Center for Microgrid of New Energy of Hubei Province, China Three Gorges University, Yichang 443002 (China); Li, Dong-Sheng, E-mail: lidongsheng1@126.com [College of Materials & Chemical Engineering, Collaborative Innovation Center for Microgrid of New Energy of Hubei Province, China Three Gorges University, Yichang 443002 (China); Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, College of Chemistry & Materials Science, Northwest University, Xi’an 710069 (China); Wang, Yao-Yu [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, College of Chemistry & Materials Science, Northwest University, Xi’an 710069 (China)

2015-10-15

Two new Co(II) metal-organic frameworks, namely [Co{sub 2}(bpm)(H{sub 2}O){sub 3}(L)]{sub n} (1) and ([Co(bpe)(H{sub 2}O)(H{sub 2}L)]·(bpe){sub 0.5}·(H{sub 2}O)){sub n} (2), (H{sub 4}L=1,1′:2′,1″-terphenyl-3,3″,4′,5′-tetracarboxylic acid, bpm=bis(4-pyridyl)amine, bpe=1,2-bis(4-pyridyl)ethene), have been obtained under hydrothermal conditions. Both complexes 1 and 2 have been characterized by elemental analysis, IR spectra, single-crystal X-ray diffraction, powder X-ray diffraction (PXRD), and thermogravimetric analysis (TGA). Complexes 1 and 2 consist of 1D Co(II) chains bridging by carboxylate groups in syn-anti fashion. 1 shows a novel 3D tri-nodal (4,6,10)-connected net with a (3.4{sup 3}.5{sup 2}){sub 2}(3{sup 2}.4{sup 14}.5{sup 12}.6{sup 12}.7{sup 4}.8)(3{sup 2}.4{sup 2}.5{sup 5}.6{sup 4}.7{sup 2}) topology. While 2 exhibits a 2D sql layer. Magnetic susceptibility measurements indicate that both 1 and 2 show weak antiferromagnetic interactions between the adjacent Co(II) ions in 300–8 K for 1 and 300–16 K for 2, respectively, and then 2 also displays ferromagnetic coupling at lower temperatures. - Graphical abstract: Two Co(II) coordination polymers with similar metal chain bridging by carboxylates in syn-anti fashion have been synthesized. Both 1 and 2 show weak antiferromagnetic interactions in high temperature, and then 2 also displays ferromagnetic coupling at lower temperatures. - Highlights: • Two Co(II) coordination polymers with similar metal chain bridging by carboxylates. • A novel 3D (4,6,10)-connected net and a 2D sql layers. • A antiferromagnetic coupling at high temperature for 1 and 2. • A ferromagnetic coupling at lower temperature for 2.

Characterization of a Single Chain Fv Antibody that Reacts with Free Morphine

OpenAIRE

Matsukizono, Miho; Kamegawa, Mariko; Tanaka, Koichi; Kohra, Shinya; Arizono, Koji; Hamazoe, Yuta; Sugimura, Kazuhisa

2013-01-01

An immune phage library derived from mice, hyperimmunized with morphine-conjugated BSA, was used to isolate a single-chain Fv (scFv) clone, M86, with binding activity to morphine-conjugated thyroglobulin (morphine-C-Tg) but not to codeine-, cocaine-, or ketamine-conjugated Tg. Surface plasmon resonance analysis using a morphine-C-Tg-coupled CM5 sensor chip showed that the Kd value was 1.26 × 10−8 M. To analyze its binding activity to free morphine and related compounds, we performed a competi...

[Attaching single- and multi-unit fixed dental prostheses

NARCIS (Netherlands)

Kreulen, C.M.; Wolke, J.G.C.; Baat, C. de; Creugers, N.H.J.

2013-01-01

A single- or multi-unit fixed dental prosthesis can be attached to the abutment teeth through mechanical retention and gap sealing or by adhesion. For sealing the gap, water-soluble cements are appropriate, such as zinc phosphate, polycarboxylate, and (resin-modified) glasionomer cement. Attachment

Targeting nanodisks via a single chain variable antibody - Apolipoprotein chimera

International Nuclear Information System (INIS)

Iovannisci, David M.; Beckstead, Jennifer A.; Ryan, Robert O.

2009-01-01

Nanodisks (ND) are nanometer scale complexes of phospholipid and apolipoprotein that have been shown to function as drug delivery vehicles. ND harboring significant quantities of the antifungal agent, amphotericin B, or the bioactive isoprenoid, all trans retinoic acid, have been generated and characterized. As currently formulated, ND possess limited targeting capability. In this study, we constructed a single chain variable antibody (scFv).apolipoprotein chimera and assessed the ability of this fusion protein to form ND and recognize the antigen to which the scFv is directed. Data obtained revealed that α-vimentin scFv.apolipoprotein A-I is functional in ND formation and antigen recognition, opening the door to the use of such chimeras in targeting drug-enriched ND to specific tissues.

Bubble dynamics and bubble-induced turbulence of a single-bubble chain

Science.gov (United States)

Lee, Joohyoung; Park, Hyungmin

2016-11-01

In the present study, the bubble dynamics and liquid-phase turbulence induced by a chain of bubbles injected from a single nozzle have been experimentally investigated. Using a high-speed two-phase particle image velociemtry, measurements on the bubbles and liquid-phase velocity field are conducted in a transparent tank filled with water, while varying the bubble release frequency from 0.1 to 35 Hz. The tested bubble size ranges between 2.0-3.2 mm, and the corresponding bubble Reynolds number is 590-1100, indicating that it belongs to the regime of path instability. As the release frequency increases, it is found that the global shape of bubble dispersion can be classified into two regimes: from asymmetric (regular) to axisymmetric (irregular). In particular, at higher frequency, the wake vortices of leading bubbles cause an irregular behaviour of the following bubble. For the liquid phase, it is found that a specific trend on the bubble-induced turbulence appears in a strong relation to the above bubble dynamics. Considering this, we try to provide a theoretical model to estimate the liquid-phase turbulence induced by a chain of bubbles. Supported by a Grant funded by Samsung Electronics, Korea.

A Single-Chain Photoswitchable CRISPR-Cas9 Architecture for Light-Inducible Gene Editing and Transcription.

Science.gov (United States)

Zhou, Xin X; Zou, Xinzhi; Chung, Hokyung K; Gao, Yuchen; Liu, Yanxia; Qi, Lei S; Lin, Michael Z

2018-02-16

Optical control of CRISPR-Cas9-derived proteins would be useful for restricting gene editing or transcriptional regulation to desired times and places. Optical control of Cas9 functions has been achieved with photouncageable unnatural amino acids or by using light-induced protein interactions to reconstitute Cas9-mediated functions from two polypeptides. However, these methods have only been applied to one Cas9 species and have not been used for optical control of different perturbations at two genes. Here, we use photodissociable dimeric fluorescent protein domains to engineer single-chain photoswitchable Cas9 (ps-Cas9) proteins in which the DNA-binding cleft is occluded at baseline and opened upon illumination. This design successfully controlled different species and functional variants of Cas9, mediated transcriptional activation more robustly than previous optogenetic methods, and enabled light-induced transcription of one gene and editing of another in the same cells. Thus, a single-chain photoswitchable architecture provides a general method to control a variety of Cas9-mediated functions.

]thiophene-Based Nonfullerene Acceptor with High Crystallinity Exhibiting Single Junction Solar Cell Efficiencies Greater than 13% with Low Voltage Losses

KAUST Repository

Fei, Zhuping

2018-01-10

A new synthetic route, to prepare an alkylated indacenodithieno[3,2-b]thiophene-based nonfullerene acceptor (C8-ITIC), is reported. Compared to the reported ITIC with phenylalkyl side chains, the new acceptor C8-ITIC exhibits a reduction in the optical band gap, higher absorptivity, and an increased propensity to crystallize. Accordingly, blends with the donor polymer PBDB-T exhibit a power conversion efficiency (PCE) up to 12.4%. Further improvements in efficiency are found upon backbone fluorination of the donor polymer to afford the novel material PFBDB-T. The resulting blend with C8-ITIC shows an impressive PCE up to 13.2% as a result of the higher open-circuit voltage. Electroluminescence studies demonstrate that backbone fluorination reduces the energy loss of the blends, with PFBDB-T/C8-ITIC-based cells exhibiting a small energy loss of 0.6 eV combined with a high JSC of 19.6 mA cm-2 .

]thiophene-Based Nonfullerene Acceptor with High Crystallinity Exhibiting Single Junction Solar Cell Efficiencies Greater than 13% with Low Voltage Losses

KAUST Repository

Fei, Zhuping; Eisner, Flurin D.; Jiao, Xuechen; Azzouzi, Mohammed; Rö hr, Jason A.; Han, Yang; Shahid, Munazza; Chesman, Anthony S. R.; Easton, Christopher D.; McNeill, Christopher R.; Anthopoulos, Thomas D.; Nelson, Jenny; Heeney, Martin

2018-01-01

A new synthetic route, to prepare an alkylated indacenodithieno[3,2-b]thiophene-based nonfullerene acceptor (C8-ITIC), is reported. Compared to the reported ITIC with phenylalkyl side chains, the new acceptor C8-ITIC exhibits a reduction in the optical band gap, higher absorptivity, and an increased propensity to crystallize. Accordingly, blends with the donor polymer PBDB-T exhibit a power conversion efficiency (PCE) up to 12.4%. Further improvements in efficiency are found upon backbone fluorination of the donor polymer to afford the novel material PFBDB-T. The resulting blend with C8-ITIC shows an impressive PCE up to 13.2% as a result of the higher open-circuit voltage. Electroluminescence studies demonstrate that backbone fluorination reduces the energy loss of the blends, with PFBDB-T/C8-ITIC-based cells exhibiting a small energy loss of 0.6 eV combined with a high JSC of 19.6 mA cm-2 .

Adsorption of a single polymer chain on a surface: effects of the potential range.

Science.gov (United States)

Klushin, Leonid I; Polotsky, Alexey A; Hsu, Hsiao-Ping; Markelov, Denis A; Binder, Kurt; Skvortsov, Alexander M

2013-02-01

We investigate the effects of the range of adsorption potential on the equilibrium behavior of a single polymer chain end-attached to a solid surface. The exact analytical theory for ideal lattice chains interacting with a planar surface via a box potential of depth U and width W is presented and compared to continuum model results and to Monte Carlo (MC) simulations using the pruned-enriched Rosenbluth method for self-avoiding chains on a simple cubic lattice. We show that the critical value U(c) corresponding to the adsorption transition scales as W(-1/ν), where the exponent ν=1/2 for ideal chains and ν≈3/5 for self-avoiding walks. Lattice corrections for finite W are incorporated in the analytical prediction of the ideal chain theory U(c)≈(π(2)/24)(W+1/2)(-2) and in the best-fit equation for the MC simulation data U(c)=0.585(W+1/2)(-5/3). Tail, loop, and train distributions at the critical point are evaluated by MC simulations for 1≤W≤10 and compared to analytical results for ideal chains and with scaling theory predictions. The behavior of a self-avoiding chain is remarkably close to that of an ideal chain in several aspects. We demonstrate that the bound fraction θ and the related properties of finite ideal and self-avoiding chains can be presented in a universal reduced form: θ(N,U,W)=θ(NU(c),U/U(c)). By utilizing precise estimations of the critical points we investigate the chain length dependence of the ratio of the normal and lateral components of the gyration radius. Contrary to common expectations this ratio attains a limiting universal value /=0.320±0.003 only at N~5000. Finite-N corrections for this ratio turn out to be of the opposite sign for W=1 and for W≥2. We also study the N dependence of the apparent crossover exponent φ(eff)(N). Strong corrections to scaling of order N(-0.5) are observed, and the extrapolated value φ=0.483±0.003 is found for all values of W. The strong correction to scaling effects found here explain why

Conjugated Polymer Chains Confined in Vertical Nanocylinders of a Block-Copolymer Film: Preparation, Characterization, and Optoelectronic Function

KAUST Repository

Dong, Ban Xuan; Honmou, Yoshihiro; Komiyama, Hideaki; Furumaki, Shu; Iyoda, Tomokazu; Vacha, Martin

2013-01-01

Hybrid materials composed of phase-separated block copolymer films and conjugated polymers of the phenylenevinylene family (PPV) are prepared. The PPV chains are embedded in vertical cylinders of nanometer diameter in the block-copolymer films. The cylinders span continuously the whole film thickness of 70 nm. Incorporation of the PPV chains into the one-dimensional cylinders leads to modified photoluminescence spectra and to large absorption anisotropy. The hybrid films show electroluminescence from the PPV chains in a simple light-emitting device at minute doping concentrations, and also exhibit a factor of 19 increase in electron transport efficiency along the single PPV chains. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Conjugated Polymer Chains Confined in Vertical Nanocylinders of a Block-Copolymer Film: Preparation, Characterization, and Optoelectronic Function

KAUST Repository

Dong, Ban Xuan

2013-01-15

Hybrid materials composed of phase-separated block copolymer films and conjugated polymers of the phenylenevinylene family (PPV) are prepared. The PPV chains are embedded in vertical cylinders of nanometer diameter in the block-copolymer films. The cylinders span continuously the whole film thickness of 70 nm. Incorporation of the PPV chains into the one-dimensional cylinders leads to modified photoluminescence spectra and to large absorption anisotropy. The hybrid films show electroluminescence from the PPV chains in a simple light-emitting device at minute doping concentrations, and also exhibit a factor of 19 increase in electron transport efficiency along the single PPV chains. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Toward tailoring Majorana bound states in artificially constructed magnetic atom chains on elemental superconductors

Science.gov (United States)

Thorwart, Michael

2018-01-01

Realizing Majorana bound states (MBS) in condensed matter systems is a key challenge on the way toward topological quantum computing. As a promising platform, one-dimensional magnetic chains on conventional superconductors were theoretically predicted to host MBS at the chain ends. We demonstrate a novel approach to design of model-type atomic-scale systems for studying MBS using single-atom manipulation techniques. Our artificially constructed atomic Fe chains on a Re surface exhibit spin spiral states and a remarkable enhancement of the local density of states at zero energy being strongly localized at the chain ends. Moreover, the zero-energy modes at the chain ends are shown to emerge and become stabilized with increasing chain length. Tight-binding model calculations based on parameters obtained from ab initio calculations corroborate that the system resides in the topological phase. Our work opens new pathways to design MBS in atomic-scale hybrid structures as a basis for fault-tolerant topological quantum computing. PMID:29756034

Molecular structure, supramolecular organization and thermotropic phase behavior of N-acylglycine alkyl esters with matched acyl and alkyl chains.

Science.gov (United States)

Reddy, S Thirupathi; Swamy, Musti J

2017-11-01

N-Acylglycines (NAGs), the endogenous single-tailed lipids present in rat brain and other mammalian tissues, play significant roles in cell physiology and exhibit interesting pharmacological properties. In the present study, a homologous series of N-acylglycine alkyl esters (NAGEs) with matched chains were synthesized and characterized. Results of differential scanning calorimetric studies revealed that all NAGEs exhibit a single sharp phase transition and that the transition enthalpy and entropy show a linear dependence on the N-acyl and ester alkyl chain length. The structure of N-myristoylglycine myristyl ester (NMGME), solved by single-crystal X-ray diffraction, showed that the molecule adopts a linear geometry and revealed that the structure of N-myristoyl glycyl moiety in NMGME is identical to that in N-myristoylglycine. The molecules are packed in layers with the polar functional groups of the ester and amide functionalities located at the center of the layer. The crystal packing is stabilized by NH⋯O hydrogen bonds between the amide CO and NH groups of adjacent molecules as well as by CH⋯O hydrogen bonds between the amide carbonyl and the methylene CH adjacent to the ester carbonyl of neighboring molecules as well as between ester carbonyl and methylene group of the glycine moiety of adjacent molecules. Powder X-ray diffraction studies showed a linear dependence of the d-spacings on the acyl chain length, suggesting that all NAGEs adopt a structure similar to the packing exhibited in the crystal lattice of NMGME. Copyright © 2017 Elsevier B.V. All rights reserved.

Early recognition is important when multiple magnets masquerade as a single chain after foreign body ingestion

Directory of Open Access Journals (Sweden)

Auriel August

2016-10-01

Full Text Available Ingestions of multiple magnets can lead to serious damage to the gastrointestinal tract. Moreover, these foreign bodies can take deceptive shapes such as single chains which may mislead clinicians. We report the case of a ten-year-old boy who swallowed 33 magnets, the most yet reported, which took on the appearance of a single loop in the stomach, while actually being located in the stomach, small bowel, and colon. Early recognition and prompt intervention are necessary to avoid complications of this foreign body misadventure.

Phase transitions of single polymer chains and of polymer solutions: insights from Monte Carlo simulations

International Nuclear Information System (INIS)

Binder, K; Paul, W; Strauch, T; Rampf, F; Ivanov, V; Luettmer-Strathmann, J

2008-01-01

The statistical mechanics of flexible and semiflexible macromolecules is distinct from that of small molecule systems, since the thermodynamic limit can also be approached when the number of (effective) monomers of a single chain (realizable by a polymer solution in the dilute limit) is approaching infinity. One can introduce effective attractive interactions into a simulation model for a single chain such that a swollen coil contracts when the temperature is reduced, until excluded volume interactions are effectively canceled by attractive forces, and the chain conformation becomes almost Gaussian at the theta point. This state corresponds to a tricritical point, as the renormalization group theory shows. Below the theta temperature a fluid globule is predicted (at nonzero concentration then phase separation between dilute and semidilute solutions occurs), while at still lower temperature a transition to a solid phase (crystal or glass) occurs. Monte Carlo simulations have shown, however, that the fluid globule phase may become suppressed, when the range of the effective attractive forces becomes too short, with the result that a direct (ultimately first-order) transition from the swollen coil to the solid occurs. This behavior is analogous to the behavior of colloidal particles with a very short range of attractive forces, where liquid-vapor-type phase separation may be suppressed. Analogous first-order transitions from swollen coils to dense rodlike or toroidal structures occur for semiflexible polymers. Finally, the modifications of the behavior discussed when the polymers are adsorbed at surfaces are also mentioned, and possible relations to wetting behavior of polymer solutions are addressed.

An unit cost adjusting heuristic algorithm for the integrated planning and scheduling of a two-stage supply chain

Directory of Open Access Journals (Sweden)

Jianhua Wang

2014-10-01

Full Text Available Purpose: The stable relationship of one-supplier-one-customer is replaced by a dynamic relationship of multi-supplier-multi-customer in current market gradually, and efficient scheduling techniques are important tools of the dynamic supply chain relationship establishing process. This paper studies the optimization of the integrated planning and scheduling problem of a two-stage supply chain with multiple manufacturers and multiple retailers to obtain a minimum supply chain operating cost, whose manufacturers have different production capacities, holding and producing cost rates, transportation costs to retailers.Design/methodology/approach: As a complex task allocation and scheduling problem, this paper sets up an INLP model for it and designs a Unit Cost Adjusting (UCA heuristic algorithm that adjust the suppliers’ supplying quantity according to their unit costs step by step to solve the model.Findings: Relying on the contrasting analysis between the UCA and the Lingo solvers for optimizing many numerical experiments, results show that the INLP model and the UCA algorithm can obtain its near optimal solution of the two-stage supply chain’s planning and scheduling problem within very short CPU time.Research limitations/implications: The proposed UCA heuristic can easily help managers to optimizing the two-stage supply chain scheduling problems which doesn’t include the delivery time and batch of orders. For two-stage supply chains are the most common form of actual commercial relationships, so to make some modification and study on the UCA heuristic should be able to optimize the integrated planning and scheduling problems of a supply chain with more reality constraints.Originality/value: This research proposes an innovative UCA heuristic for optimizing the integrated planning and scheduling problem of two-stage supply chains with the constraints of suppliers’ production capacity and the orders’ delivering time, and has a great

First principles studies of the electronic properties and catalytic activity of single-walled carbon nanotube doped with Pt clusters and chains

International Nuclear Information System (INIS)

Hayes, Kayla E.; Lee, Hee-Seung

2012-01-01

Highlights: ► Electronic and magnetic properties of (5, 5)-SWNT doped with Pt clusters and chains. ► Pt-doping can change metallic (5, 5)-SWNT to semiconducting CNT. ► Oxygen adsorption on Pt-doped (5, 5)-SWNT is barrierless process. ► Pt-doping reduces the activation barrier of oxygen dissociation reaction. ► Adsorbed oxygen has 2 O 2 - – character. - Abstract: We report the results of density functional theory calculations on the electronic structures, geometrical parameters, and magnetic properties of a wide variety of Pt clusters/chains adsorbed on metallic (5,5) single-walled carbon nanotube (SWNT). It was found that the electronic band structures of Pt/CNT systems are very sensitive to the small changes in the geometries of Pt clusters and chains. In some cases, metallic (5, 5)-SWNT becomes a small-gap semiconducting nanotube with adsorbed Pt clusters and chains. We also investigated the dissociation of molecular oxygen on the (5, 5)-SWNT doped with a single Pt atom via the nudged elastic band (NEB) method. The NEB results showed that the activation barrier is lowered even with a single Pt atom compared to that of pristine SWNT. It was found that the electronic structure of molecular oxygen adsorbed on Pt-doped CNT resembles that of 2 O 2 - , which should facilitate the dissociation process.

Single-unit studies of visual motion processing in cat extrastriate areas

NARCIS (Netherlands)

Vajda, Ildiko

2003-01-01

Motion vision has high survival value and is a fundamental property of all visual systems. The old Greeks already studied motion vision, but the physiological basis of it first came under scrutiny in the late nineteenth century. Later, with the introduction of single-cell (single-unit)

Optimal Decisions in a Single-Period Supply Chain with Price-Sensitive Random Demand under a Buy-Back Contract

Directory of Open Access Journals (Sweden)

Feng Wang

2014-01-01

Full Text Available This paper studies a single-period supply chain with a buy-back contract under a Stackelberg game model, in which the supplier (leader decides on the wholesale price, and the retailer (follower responds to determine the retail price and the order quantity. We analytically investigate the decentralized retailer’s optimal decision. Our results demonstrate that the retailer has a unique optimal simultaneous decision on the retail price and the order quantity, under a mild restriction on the demand distribution. Moreover, as it can be shown that the decentralized supply chain facing price-sensitive random demand cannot be coordinated with buy-back contract, we propose a scheme for the system to achieve Pareto-improvement. Theoretical analysis suggests that there exists a unique Pareto-equilibrium for the supply chain. In particular, when the Pareto-equilibrium is reached, the supply chain is coordinated. Numerical experiments confirm our results.

Crystal structure of the anti-(carcinoembryonic antigen) single-chain Fv antibody MFE-23 and a model for antigen binding based on intermolecular contacts.

Science.gov (United States)

Boehm, M K; Corper, A L; Wan, T; Sohi, M K; Sutton, B J; Thornton, J D; Keep, P A; Chester, K A; Begent, R H; Perkins, S J

2000-03-01

MFE-23 is the first single-chain Fv antibody molecule to be used in patients and is used to target colorectal cancer through its high affinity for carcinoembryonic antigen (CEA), a cell-surface member of the immunoglobulin superfamily. MFE-23 contains an N-terminal variable heavy-chain domain joined by a (Gly(4)Ser)(3) linker to a variable light-chain (V(L)) domain (kappa chain) with an 11-residue C-terminal Myc-tag. Its crystal structure was determined at 2.4 A resolution by molecular replacement with an R(cryst) of 19.0%. Five of the six antigen-binding loops, L1, L2, L3, H1 and H2, conformed to known canonical structures. The sixth loop, H3, displayed a unique structure, with a beta-hairpin loop and a bifurcated apex characterized by a buried Thr residue. In the crystal lattice, two MFE-23 molecules were associated back-to-back in a manner not seen before. The antigen-binding site displayed a large acidic region located mainly within the H2 loop and a large hydrophobic region within the H3 loop. Even though this structure is unliganded within the crystal, there is an unusually large region of contact between the H1, H2 and H3 loops and the beta-sheet of the V(L) domain of an adjacent molecule (strands DEBA) as a result of intermolecular packing. These interactions exhibited remarkably high surface and electrostatic complementarity. Of seven MFE-23 residues predicted to make contact with antigen, five participated in these lattice contacts, and this model for antigen binding is consistent with previously reported site-specific mutagenesis of MFE-23 and its effect on CEA binding.

Conformation of single block copolymer chain in two-dimensional microphase-separated structure studied by scanning near-field optical microscopy.

Science.gov (United States)

Sekine, Ryojun; Aoki, Hiroyuki; Ito, Shinzaburo

2009-05-21

The localization and orientation of the symmetric diblock copolymer chain in a quasi-two-dimensional microphase-separated structure were studied by scanning near-field optical microscopy (SNOM). In the monolayer of poly(isobutyl methacrylate)-block-poly(octadecyl methacrylate) (PiBMA-b-PODMA), the individual PiBMA subchains were directly observed by SNOM, and the center of mass (CM) and orientational angle relative to the phase interface were examined at the single chain level. It was found that the position of the CM and the orientation of the PiBMA subchain in the lamellar structure were dependent on the curvature of the PiBMA/PODMA interface. As the interface was bent toward the objective chain, the block chain preferred the CM position closer to the domain center, and the conformation was strongly oriented perpendicularly to the domain interface. With increase of the curvature, the steric hindrance among the block chain increases, resulting in the stretched conformation.

Single-molecule imaging reveals topological isomer-dependent diffusion by 4-armed star and dicyclic 8-shaped polymers

KAUST Repository

Habuchi, Satoshi

2015-04-21

Diffusion dynamics of topological isomers of polymer molecules was investigated at the single-molecule level in a melt state by employing the fluorophore-incorporated 4-armed star and the corresponding doubly-cyclized, 8-shaped poly(THF) chains. While the single-molecule fluorescence imaging experiment revealed that the diffusion of the 4-armed star polymer was described by a single Gaussian distribution, the diffusion of the 8-shaped polymer exhibited a double Gaussian distribution behaviour. We reasoned that the two 8-shaped polymeric isomers have distinct diffusion modes in the melt state, although ensemble-averaged experimental methods cannot detect differences in overall conformational state of the isomers. The single-molecule experiments suggested that one of the 8-shaped polymeric isomer, having the horizontally oriented form, causes an efficient threading with the linear matrix chains which leads to the slower diffusion compared with the corresponding 4-armed star polymer, while the other 8-shaped polymeric isomer, having the vertically oriented form, displayed faster diffusion by the suppression of effective threading with the linear matrix chains due to its contracted chain conformation.

Electrical contacts to nanorod networks at different length scales: From macroscale ensembles to single nanorod chains

KAUST Repository

Lavieville, Romain; Zhang, Yang; Di Fabrizio, Enzo M.; Krahne, Roman

2013-01-01

The nature of metal-semiconductor interfaces at the nanoscale is an important issue in micro- and nanoelectronic engineering. The study of charge transport through chains of CdSe semiconductor nanorods linked by Au particles represents an ideal model system for this matter, because the metal semiconductor interface is an intrinsic feature of the nanosystem. Here we show the controlled fabrication of all-inorganic hybrid metal-semiconductor networks with different size, in which the semiconductor nanorods are linked by Au domains at their tips. We demonstrate different approaches to selectively contact the networks and single nanorod chains with planar electrodes, and we investigate their charge transport at room temperature. © 2013 Elsevier B.V. All rights reserved.

Electrical contacts to nanorod networks at different length scales: From macroscale ensembles to single nanorod chains

KAUST Repository

Lavieville, Romain

2013-11-01

The nature of metal-semiconductor interfaces at the nanoscale is an important issue in micro- and nanoelectronic engineering. The study of charge transport through chains of CdSe semiconductor nanorods linked by Au particles represents an ideal model system for this matter, because the metal semiconductor interface is an intrinsic feature of the nanosystem. Here we show the controlled fabrication of all-inorganic hybrid metal-semiconductor networks with different size, in which the semiconductor nanorods are linked by Au domains at their tips. We demonstrate different approaches to selectively contact the networks and single nanorod chains with planar electrodes, and we investigate their charge transport at room temperature. © 2013 Elsevier B.V. All rights reserved.

Ownership, financing, and management strategies of the ten largest for-profit nursing home chains in the United States.

Science.gov (United States)

Harrington, Charlene; Hauser, Clarilee; Olney, Brian; Rosenau, Pauline Vaillancourt

2011-01-01

This study examined the ownership, financing, and management strategies of the 10 largest for-profit nursing home chains in the United States, including the four largest chains purchased by private equity corporations. Descriptive data were collected from Internet searches, company reports, and other sources for the decade 1998-2008. Since 1998, the largest chains have made many changes in their ownership and structure, and some have converted from publicly traded companies to private ownership. This study shows the increasing complexity of corporate nursing home ownership and the lack of public information about ownership and financial status. The chains have used strategies to maximize shareholder and investor value that include increasing Medicare revenues, occupancy rates, and company diversification, establishing multiple layers of corporate ownership, developing real estate investment trusts, and creating limited liability companies. These strategies enhance shareholder and investor profits, reduce corporate taxes, and reduce liability risk. There is a need for greater transparency in ownership and financial reporting and for more government oversight of the largest for-profit chains, including those owned by private equity companies.

Escherichia coli surface display of single-chain antibody VRC01 against HIV-1 infection

International Nuclear Information System (INIS)

Wang, Lin-Xu; Mellon, Michael; Bowder, Dane; Quinn, Meghan; Shea, Danielle; Wood, Charles; Xiang, Shi-Hua

2015-01-01

Human immunodeficiency virus type 1 (HIV-1) transmission and infection occur mainly via the mucosal surfaces. The commensal bacteria residing in these surfaces can potentially be employed as a vehicle for delivering inhibitors to prevent HIV-1 infection. In this study, we have employed a bacteria-based strategy to display a broadly neutralizing antibody VRC01, which could potentially be used to prevent HIV-1 infection. The VRC01 antibody mimics CD4-binding to gp120 and has broadly neutralization activities against HIV-1. We have designed a construct that can express the fusion peptide of the scFv-VRC01 antibody together with the autotransporter β-barrel domain of IgAP gene from Neisseria gonorrhoeae, which enabled surface display of the antibody molecule. Our results indicate that the scFv-VRC01 antibody molecule was displayed on the surface of the bacteria as demonstrated by flow cytometry and immunofluorescence microscopy. The engineered bacteria can capture HIV-1 particles via surface-binding and inhibit HIV-1 infection in cell culture. - Highlights: • Designed single-chain VRC01 antibody was demonstrated to bind HIV-1 envelope gp120. • Single-chain VRC01 antibody was successfully displayed on the surface of E. coli. • Engineered bacteria can absorb HIV-1 particles and prevent HIV-1 infection in cell culture

End-anchored polymers in good solvents from the single chain limit to high anchoring densities.

Science.gov (United States)

Whitmore, Mark D; Grest, Gary S; Douglas, Jack F; Kent, Michael S; Suo, Tongchuan

2016-11-07

An increasing number of applications utilize grafted polymer layers to alter the interfacial properties of solid substrates, motivating refinement in our theoretical understanding of such layers. To assess existing theoretical models of them, we have investigated end-anchored polymer layers over a wide range of grafting densities, σ, ranging from a single chain to high anchoring density limits, chain lengths ranging over two orders of magnitude, for very good and marginally good solvent conditions. We compare Monte Carlo and molecular dynamics simulations, numerical self-consistent field calculations, and experimental measurements of the average layer thickness, h, with renormalization group theory, the Alexander-de Gennes mushroom theory, and the classical brush theory. Our simulations clearly indicate that appreciable inter-chain interactions exist at all simulated areal anchoring densities so that there is no mushroom regime in which the layer thickness is independent of σ. Moreover, we find that there is no high coverage regime in which h follows the predicted scaling, h ∼ Nσ 1/3 , for classical polymer brushes either. Given that no completely adequate analytic theory seems to exist that spans wide ranges of N and σ, we applied scaling arguments for h as a function of a suitably defined reduced anchoring density, defined in terms of the solution radius of gyration of the polymer chains and N. We find that such a scaling approach enables a smooth, unified description of h in very good solvents over the full range of anchoring density and chain lengths, although this type of data reduction does not apply to marginal solvent quality conditions.

The use of a cocktail of single chain Fv antibody fragments to improve the in vitro and in vivo targeting of melanoma

International Nuclear Information System (INIS)

Pacifico, M.D.; Pearl, R.A.; Kupsch, J.M.

2006-01-01

Radio scintigraphy using single chain antibody fragments (scFvs) offers a potenti al means of early detection of melanoma metastases. However, previous studies have shown suboptimal levels of tumour localization and nonspecific background accumulation which may be due to antigen heterogeneity. We aimed to improve tumour localization by using a cocktail of different scFvs targeting different epitopes on melanoma cells. We have previously developed three scFvs against distinct and highly tumour-specific melanoma cell-surface antigens by chain shuffling and antibody phage selection on melanoma cells. Three scFvs, RAFT3, B3 and B4 were labeled with 1 25I odine and tested both individually and as a cocktail in a nude mouse xenograft model far human melanoma. Results demonstrated improved tumour localization in vivo when compared to the individual scFvs. Tumour uptake of the cocktail at l hour was 24.220% ID/g (injected dose/gram) compared with 2.854%, 2.263% and 1.355% far B4, RAFT3 and B3, respectively, when injected individually. In addition, the cocktail exhibited significantly superior tumour to normal tissue ratios far muscle and spleen (p<0.05). A combination or cocktail of scFv clones may have an advantage aver individual scFvs far melanoma targeting in patients because of heterogeneity in the expression of different epitopes of antigens on melanoma cells

Effective single chain antibody (scFv) concentrations in vivo via adenoviral vector mediated expression of secretory scFv

NARCIS (Netherlands)

Arafat, WO; Gomez-Navarro, J; Buchsbaum, DJ; Xiang, J; Casado, E; Barker, SD; Mahasreshti, PJ; Haisma, HJ; Barnes, MN; Siegal, GP; Alvarez, RD; Hemminki, A; Nettelbeck, DM; Curiel, DT

Single chain antibodies (scFv) represent powerful interventional agents for the achievement of targeted therapeutics. The practical utility of these agents have been limited, however, by difficulties related to production of recombinant scFv and the achievement of effective and sustained levels of

Unbiased analysis of TCRα/β chains at the single-cell level in human CD8+ T-cell subsets.

Science.gov (United States)

Sun, Xiaoming; Saito, Masumichi; Sato, Yoshinori; Chikata, Takayuki; Naruto, Takuya; Ozawa, Tatsuhiko; Kobayashi, Eiji; Kishi, Hiroyuki; Muraguchi, Atsushi; Takiguchi, Masafumi

2012-01-01

T-cell receptor (TCR) α/β chains are expressed on the surface of CD8(+) T-cells and have been implicated in antigen recognition, activation, and proliferation. However, the methods for characterization of human TCRα/β chains have not been well established largely because of the complexity of their structures owing to the extensive genetic rearrangements that they undergo. Here we report the development of an integrated 5'-RACE and multiplex PCR method to amplify the full-length transcripts of TCRα/β at the single-cell level in human CD8(+) subsets, including naive, central memory, early effector memory, late effector memory, and effector phenotypic cells. Using this method, with an approximately 47% and 62% of PCR success rate for TCRα and for TCRβ chains, respectively, we were able to analyze more than 1,000 reads of transcripts of each TCR chain. Our comprehensive analysis revealed the following: (1) chimeric rearrangements of TCRδ-α, (2) control of TCRα/β transcription with multiple transcriptional initiation sites, (3) altered utilization of TCRα/β chains in CD8(+) subsets, and (4) strong association between the clonal size of TCRα/β chains and the effector phenotype of CD8(+) T-cells. Based on these findings, we conclude that our method is a useful tool to identify the dynamics of the TCRα/β repertoire, and provides new insights into the study of human TCRα/β chains.

Splitting Terraced Houses Into Single Units Using Oblique Aerial Imagery

Science.gov (United States)

Dahlke, D.

2017-05-01

This paper introduces a method to subdivide complex building structures like terraced houses into single house units comparable to units available in a cadastral map. 3D line segments are detected with sub-pixel accuracy in traditional vertical true orthomosaics as well as in innovative oblique true orthomosaics and their respective surface models. Hereby high gradient strengths on roofs as well as façades are taken into account. By investigating the coplanarity and frequencies within a set of 3D line segments, individual cut lines for a building complex are found. The resulting regions ideally describe single houses and thus the object complexity is reduced for subsequent topological, semantical or geometrical considerations. For the chosen study area with 70 buidling outlines a hit rate of 80% for cut lines is achieved.

Contaminant transport in fractured porous media: analytical solution for a two-member decay chain in a single fracture

International Nuclear Information System (INIS)

Sudicky, E.A.; Frind, E.O.

1984-01-01

An analytical solution is presented for the problem of radionuclide chain decay during transport through a discrete fracture situated in a porous rock matrix. The solution takes into account advection along the fracture, molecular diffusion from the fracture to the porous matrix, adsorption on the fracture face, adsorption in the rock matrix, and radioactive decay. The solution for the daughter product is in the form of a double integral which is evaluated by Gauss-Legendre quadrature. Results show that the daughter product tends to advance ahead of the parent nuclide even when the half-life of the parent is larger. This is attributed to the effect of chain decay in the matrix, which tends to reduce the diffusive loss of the daughter along the fracture. The examples also demonstrate that neglecting the parent nuclide and modeling its daughter as a single species can result in significant overestimation of arrival times at some point along the fracture. Although the analytical solution is restricted to a two-member chain for practical reasons, it represents a more realistic description of nuclide transport along a fracture than available single-species models. The solution may be of use for application to other contaminants undergoing different types of first-order transformation reactions

Engineering single-polymer micelle shape using nonuniform spontaneous surface curvature

Science.gov (United States)

Moths, Brian; Witten, T. A.

2018-03-01

Conventional micelles, composed of simple amphiphiles, exhibit only a few standard morphologies, each characterized by its mean surface curvature set by the amphiphiles. Here we demonstrate a rational design scheme to construct micelles of more general shape from polymeric amphiphiles. We replace the many amphiphiles of a conventional micelle by a single flexible, linear, block copolymer chain containing two incompatible species arranged in multiple alternating segments. With suitable segment lengths, the chain exhibits a condensed spherical configuration in solution, similar to conventional micelles. Our design scheme posits that further shapes are attained by altering the segment lengths. As a first study of the power of this scheme, we demonstrate the capacity to produce long-lived micelles of horseshoe form using conventional bead-spring simulations in two dimensions. Modest changes in the segment lengths produce smooth changes in the micelle's shape and stability.

Ground-state phase diagram of an (S, S') = (1, 2) spin-alternating chain with competing single-ion anisotropies

International Nuclear Information System (INIS)

Tonegawa, T; Okamoto, K; Sakai, T; Kaburagi, M

2009-01-01

Employing various numerical methods, we determine the ground-state phase diagram of an (S, S') = (1, 2) spin-alternating chain with antiferromagnetic nearest-neighboring exchange interactions and uniaxial single-ion anisotropies. The resulting phase diagram consists of eight kinds of phases including two phases which accompany the spontaneous breaking of the translational symmetry and a ferrimagnetic phase in which the ground-state magnetization varies continuously with the uniaxial single-ion anisotropy constants for the S=1 and S =2 spins. The appearance of these three phases is attributed to the competition between the uniaxial single-ion anisotropies of both spins.

The normally expressed kappa immunoglobulin light chain gene repertoire and somatic mutations studied by single-sided specific polymerase chain reaction (PCR); frequent occurrence of features often assigned to autoimmunity

DEFF Research Database (Denmark)

Juul, L; Hougs, L; Andersen, V

1997-01-01

The expressed human kappa light chain gene repertoire utilized by healthy individuals was studied by two different single-sided specific PCR techniques to avoid bias for certain V genes. A total of 103 rearranged kappa sequences from peripheral blood mononuclear cells from healthy individuals were...

A conceptual framework for economic optimization of single hazard surveillance in livestock production chains.

Science.gov (United States)

Guo, Xuezhen; Claassen, G D H; Oude Lansink, A G J M; Saatkamp, H W

2014-06-01

Economic analysis of hazard surveillance in livestock production chains is essential for surveillance organizations (such as food safety authorities) when making scientifically based decisions on optimization of resource allocation. To enable this, quantitative decision support tools are required at two levels of analysis: (1) single-hazard surveillance system and (2) surveillance portfolio. This paper addresses the first level by presenting a conceptual approach for the economic analysis of single-hazard surveillance systems. The concept includes objective and subjective aspects of single-hazard surveillance system analysis: (1) a simulation part to derive an efficient set of surveillance setups based on the technical surveillance performance parameters (TSPPs) and the corresponding surveillance costs, i.e., objective analysis, and (2) a multi-criteria decision making model to evaluate the impacts of the hazard surveillance, i.e., subjective analysis. The conceptual approach was checked for (1) conceptual validity and (2) data validity. Issues regarding the practical use of the approach, particularly the data requirement, were discussed. We concluded that the conceptual approach is scientifically credible for economic analysis of single-hazard surveillance systems and that the practicability of the approach depends on data availability. Copyright © 2014 Elsevier B.V. All rights reserved.

Shaping the breast in secondary microsurgical breast reconstruction: single- vs. two-esthetic unit reconstruction.

Science.gov (United States)

Gravvanis, Andreas; Smith, Roger W

2010-10-01

The esthetic outcome is dictated essentially not only by the position, size, and shape of the reconstructed breast, but also by the extra scaring involved. In the present study, we conducted a visual analog scale survey to compare the esthetic outcome in delayed autologous breast reconstruction following two different abdominal flaps inset. Twenty-five patients had their reconstruction using the Single-esthetic Unit principle and were compared with 25 patients that their breast was reconstructed using the Two-Esthetic Unit principle. Photographic images were formulated to a PowerPoint presentation and cosmetic outcomes were assessed from 30 physicians, by means of a Questionnaire and a visual analog scale. Our data showed that the single-esthetic unit breast reconstruction presents significant advantages over the traditional two-esthetic units, due to inconspicuous flap reconstruction, better position of the inframammary fold, and more natural transition from native and reconstructed tissues. Moreover, patient self-evaluation of esthetic outcome and quality of life showed that single-esthetic unit reconstruction is associated with higher patient satisfaction, therefore should be considered the method of choice. © 2010 Wiley-Liss, Inc.

Unbiased analysis of TCRα/β chains at the single-cell level in human CD8+ T-cell subsets.

Directory of Open Access Journals (Sweden)

Xiaoming Sun

Full Text Available T-cell receptor (TCR α/β chains are expressed on the surface of CD8(+ T-cells and have been implicated in antigen recognition, activation, and proliferation. However, the methods for characterization of human TCRα/β chains have not been well established largely because of the complexity of their structures owing to the extensive genetic rearrangements that they undergo. Here we report the development of an integrated 5'-RACE and multiplex PCR method to amplify the full-length transcripts of TCRα/β at the single-cell level in human CD8(+ subsets, including naive, central memory, early effector memory, late effector memory, and effector phenotypic cells. Using this method, with an approximately 47% and 62% of PCR success rate for TCRα and for TCRβ chains, respectively, we were able to analyze more than 1,000 reads of transcripts of each TCR chain. Our comprehensive analysis revealed the following: (1 chimeric rearrangements of TCRδ-α, (2 control of TCRα/β transcription with multiple transcriptional initiation sites, (3 altered utilization of TCRα/β chains in CD8(+ subsets, and (4 strong association between the clonal size of TCRα/β chains and the effector phenotype of CD8(+ T-cells. Based on these findings, we conclude that our method is a useful tool to identify the dynamics of the TCRα/β repertoire, and provides new insights into the study of human TCRα/β chains.

A SEROLOGIC AND POLYMERASE CHAIN REACTION SURVEY OF EQUINE HERPESVIRUS IN BURCHELL'S ZEBRAS (EQUUS QUAGGA), HARTMANN'S MOUNTAIN ZEBRAS (EQUUS ZEBRA HARTMANNAE), AND THOMSON'S GAZELLES (EUDORCAS THOMSONII) IN A MIXED SPECIES SAVANNAH EXHIBIT.

Science.gov (United States)

Lopez, Karen M; Fleming, Gregory J; Mylniczenko, Natalie D

2016-12-01

Reports of equine herpesvirus (EHV) 1 and EHV-9 causing clinical disease in a wide range of species have been well documented in the literature. It is thought that zebras are the natural hosts of EHV-9 both in the wild and in captive collections. Concerns about potential interspecies transmission of EHV-1 and EHV-9 in a mixed species savannah exhibit prompted serologic and polymerase chain reaction surveys. Eighteen Burchell's zebras ( Equus quagga ), 11 Hartmann's mountain zebras ( Equus zebra hartmannae), and 14 Thomson's gazelles ( Eudorcas thomsonii ) cohabitating the same exhibit were examined for EHV-1 virus neutralization titers, and evidence of virus via EHV 1-5 polymerase chain reactions. None of the animals had previous exposure to vaccination with EHV-1 or EHV-4. All tested zebras had positive EHV-1 titers, ranging from 4 to 384. All zebras and Thomson's gazelles had negative polymerase chain reaction results for all targeted equine herpesviruses. EHV-9-specific assays are not available but EHV-1, EHV-4, and EHV-9 cross-react serologically. Positive serology results indicate a potential latent equine herpesvirus in the zebra population, which prompted initiation of an equine herpesvirus vaccine protocol, changes in pregnant zebra mare management, and equine herpesvirus polymerase chain reaction screening prior to shipment to or from the study site.

Single-unit pattern generators for quadruped locomotion

DEFF Research Database (Denmark)

Morse, Gregory; Risi, Sebastian; Snyder, Charles R

2013-01-01

Legged robots can potentially venture beyond the limits of wheeled vehicles. While creating controllers for such robots by hand is possible, evolutionary algorithms are an alternative that can reduce the burden of hand-crafting robotic controllers. Although major evolutionary approaches to legged...... on a new type of neuron called a single-unit pattern generator (SUPG). The SUPG, which is indirectly encoded by a compositional pattern producing network (CPPN) evolved by HyperNEAT, produces a flexible temporal activation pattern that can be reset and repeated at any time through an explicit trigger input...

Development of coordination system model on single-supplier multi-buyer for multi-item supply chain with probabilistic demand

Science.gov (United States)

Olivia, G.; Santoso, A.; Prayogo, D. N.

2017-11-01

Nowadays, the level of competition between supply chains is getting tighter and a good coordination system between supply chains members is very crucial in solving the issue. This paper focused on a model development of coordination system between single supplier and buyers in a supply chain as a solution. Proposed optimization model was designed to determine the optimal number of deliveries from a supplier to buyers in order to minimize the total cost over a planning horizon. Components of the total supply chain cost consist of transportation costs, handling costs of supplier and buyers and also stock out costs. In the proposed optimization model, the supplier can supply various types of items to retailers whose item demand patterns are probabilistic. Sensitivity analysis of the proposed model was conducted to test the effect of changes in transport costs, handling costs and production capacities of the supplier. The results of the sensitivity analysis showed a significant influence on the changes in the transportation cost, handling costs and production capacity to the decisions of the optimal numbers of product delivery for each item to the buyers.

Accelerating the coupled-cluster singles and doubles method using the chain-of-sphere approximation

Science.gov (United States)

Dutta, Achintya Kumar; Neese, Frank; Izsák, Róbert

2018-06-01

In this paper, we present a chain-of-sphere implementation of the external exchange term, the computational bottleneck of coupled-cluster calculations at the singles and doubles level. This implementation is compared to standard molecular orbital, atomic orbital and resolution of identity implementations of the same term within the ORCA package and turns out to be the most efficient one for larger molecules, with a better accuracy than the resolution-of-identity approximation. Furthermore, it becomes possible to perform a canonical CC calculation on a tetramer of nucleobases in 17 days, 20 hours.

MOTOR UNIT TERRITORIES AND FIBER TYPES IN RABBIT MASSETER MUSCLE

NARCIS (Netherlands)

WEIJS, WA; JUCH, PJW; KWA, SHS; KORFAGE, JAM

1993-01-01

The myosin heavy chain (MHC) content and spatial distribution of the fibers of 11 motor units (MUs) of the rabbit masseter muscle were determined. The fibers of single MUs were visualized in whole-muscle serial sections by a negative periodic acid/Schiff reaction for glycogen after they had been

X-ray quality increasing system controlled by single-chip microcomputer in single phase fluoroscopy unit

International Nuclear Information System (INIS)

Wang Qiaolin; Gu Hongmei

2004-01-01

Objective: To decrease the amount of radiation that doctor and patient receives by increasing X-ray quality. Methods: Using Single-chip Microcomputer technology, test and modulate AC(Alternating Current) from high voltage generator by IGBT. X-ray tube generates X-rays only at high energy area. Thus the amount of radiation decreases. Results: The tube current decreases remarkably and the amount of radiation that doctor and patient receives decreases effectively. Conclusion: the system can effectively decrease the amount of radiation and is widely applicable to the upgrade of all kinds of single phase X-ray units. (authors)

Disruption management in a two-period three-tier electronics supply chain

Directory of Open Access Journals (Sweden)

Johannes Danusantoso

2016-12-01

Full Text Available We study strategies to manage demand disruptions in a three-tier electronics supply chain consisting of an Electronics Manufacturing Services provider, an Original Equipment Manufacturer (OEM, and a Retailer. We model price sensitivity of consumer demand with the two functions commonly used for this purpose, linear and exponential, and introduce disruptions in the demand function. We assume each supply chain member faces an increasing marginal unit cost function. Our decentralized supply chain setting is governed by a wholesale price contract. The OEM possesses greater bargaining power and therefore is the Stackelberg leader. A penalty cost incurred by the Retailer is introduced to capture the cost of deviation from the original plan. We find exact analytical solutions of the effectiveness of managing the disruption when the consumer demand function is linear, and we provide numerical examples as an illustration when the consumer demand function is either linear or exponential. We show that the original production quantity exhibits some robustness under disruptions in both centralized and decentralized supply chains, while the original optimal pricing does not. We show that supply chain managers should not automatically react to an individual disruption, in certain cases it is best to leave the production plan unchanged.

Bioaccumulation and Toxicity of Single-Walled Carbon Nanotubes to Benthic Organisms at the Base of the Marine Food Chain

Science.gov (United States)

As the use of single-walled carbon nanotubes (SWNTs) increases over time, so does the potential for environmental release. This research aimed to determine the toxicity, bioavailability, and bioaccumulation of SWNTs in marine benthic organisms at the base of the food chain. The t...

EARLINET Single Calculus Chain - overview on methodology and strategy

Science.gov (United States)

D'Amico, G.; Amodeo, A.; Baars, H.; Binietoglou, I.; Freudenthaler, V.; Mattis, I.; Wandinger, U.; Pappalardo, G.

2015-11-01

In this paper we describe the EARLINET Single Calculus Chain (SCC), a tool for the automatic analysis of lidar measurements. The development of this tool started in the framework of EARLINET-ASOS (European Aerosol Research Lidar Network - Advanced Sustainable Observation System); it was extended within ACTRIS (Aerosol, Clouds and Trace gases Research InfraStructure Network), and it is continuing within ACTRIS-2. The main idea was to develop a data processing chain that allows all EARLINET stations to retrieve, in a fully automatic way, the aerosol backscatter and extinction profiles starting from the raw lidar data of the lidar systems they operate. The calculus subsystem of the SCC is composed of two modules: a pre-processor module which handles the raw lidar data and corrects them for instrumental effects and an optical processing module for the retrieval of aerosol optical products from the pre-processed data. All input parameters needed to perform the lidar analysis are stored in a database to keep track of all changes which may occur for any EARLINET lidar system over the time. The two calculus modules are coordinated and synchronized by an additional module (daemon) which makes the whole analysis process fully automatic. The end user can interact with the SCC via a user-friendly web interface. All SCC modules are developed using open-source and freely available software packages. The final products retrieved by the SCC fulfill all requirements of the EARLINET quality assurance programs on both instrumental and algorithm levels. Moreover, the manpower needed to provide aerosol optical products is greatly reduced and thus the near-real-time availability of lidar data is improved. The high-quality of the SCC products is proven by the good agreement between the SCC analysis, and the corresponding independent manual retrievals. Finally, the ability of the SCC to provide high-quality aerosol optical products is demonstrated for an EARLINET intense observation

Radiation induced solid-state polymerization of long-chain acrylates containing fluorocarbon chain

International Nuclear Information System (INIS)

Shibasaki, Y.; Zhu, Zhi-Qin

1995-01-01

γ-Ray irradiation post-polymerizations of long-chain acrylates containing fluorocarbon chain, H(CF 2 ) 10 CH 2 OCOCH=CH 2 and H(CF 2 ) 8 CH 2 OCOCH=CH 2 , were investigated and also the structures and thermal properties of comb-like polymers obtained were studied. It was found that these monomers exhibited very high polymerizability at wide temperature ranges around the melting points. Because the fluorocarbon chains are less flexible and thicker than the hydrocarbon chains, it can be expected that the aggregation force among the monomer molecules is strong and the conformational freedom of functional group for polymerization is large. According to the DSC and the X-ray diffraction measurements of the comb-like polymers obtained, the fluorocarbon chains are aggregated in a mode of hexagonal packing in the lamellar crystals. This situation can be considered as an optimum condition for the γ-ray irradiation post-polymerization. (author)

Single unit approaches to human vision and memory.

Science.gov (United States)

Kreiman, Gabriel

2007-08-01

Research on the visual system focuses on using electrophysiology, pharmacology and other invasive tools in animal models. Non-invasive tools such as scalp electroencephalography and imaging allow examining humans but show a much lower spatial and/or temporal resolution. Under special clinical conditions, it is possible to monitor single-unit activity in humans when invasive procedures are required due to particular pathological conditions including epilepsy and Parkinson's disease. We review our knowledge about the visual system and visual memories in the human brain at the single neuron level. The properties of the human brain seem to be broadly compatible with the knowledge derived from animal models. The possibility of examining high-resolution brain activity in conscious human subjects allows investigators to ask novel questions that are challenging to address in animal models.

Finite-size effects on the dynamic susceptibility of CoPhOMe single-chain molecular magnets in presence of a static magnetic field

Science.gov (United States)

Pini, M. G.; Rettori, A.; Bogani, L.; Lascialfari, A.; Mariani, M.; Caneschi, A.; Sessoli, R.

2011-09-01

The static and dynamic properties of the single-chain molecular magnet Co(hfac)2NITPhOMe (CoPhOMe) (hfac = hexafluoroacetylacetonate, NITPhOMe = 4'-methoxy-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) are investigated in the framework of the Ising model with Glauber dynamics, in order to take into account both the effect of an applied magnetic field and a finite size of the chains. For static fields of moderate intensity and short chain lengths, the approximation of a monoexponential decay of the magnetization fluctuations is found to be valid at low temperatures; for strong fields and long chains, a multiexponential decay should rather be assumed. The effect of an oscillating magnetic field, with intensity much smaller than that of the static one, is included in the theory in order to obtain the dynamic susceptibility χ(ω). We find that, for an open chain with N spins, χ(ω) can be written as a weighted sum of N frequency contributions, with a sum rule relating the frequency weights to the static susceptibility of the chain. Very good agreement is found between the theoretical dynamic susceptibility and the ac susceptibility measured in moderate static fields (Hdc≤2 kOe), where the approximation of a single dominating frequency for each segment length turns out to be valid. For static fields in this range, data for the relaxation time, τ versus Hdc, of the magnetization of CoPhOMe at low temperature are also qualitatively reproduced by theory, provided that finite-size effects are included.

Single cells from human primary colorectal tumors exhibit polyfunctional heterogeneity in secretions of ELR+ CXC chemokines.

Science.gov (United States)

Adalsteinsson, Viktor A; Tahirova, Narmin; Tallapragada, Naren; Yao, Xiaosai; Campion, Liam; Angelini, Alessandro; Douce, Thomas B; Huang, Cindy; Bowman, Brittany; Williamson, Christina A; Kwon, Douglas S; Wittrup, K Dane; Love, J Christopher

2013-10-01

Cancer is an inflammatory disease of tissue that is largely influenced by the interactions between multiple cell types, secreted factors, and signal transduction pathways. While single-cell sequencing continues to refine our understanding of the clonotypic heterogeneity within tumors, the complex interplay between genetic variations and non-genetic factors ultimately affects therapeutic outcome. Much has been learned through bulk studies of secreted factors in the tumor microenvironment, but the secretory behavior of single cells has been largely uncharacterized. Here we directly profiled the secretions of ELR+ CXC chemokines from thousands of single colorectal tumor and stromal cells, using an array of subnanoliter wells and a technique called microengraving to characterize both the rates of secretion of several factors at once and the numbers of cells secreting each chemokine. The ELR+ CXC chemokines are highly redundant, pro-angiogenic cytokines that signal via the CXCR1 and CXCR2 receptors, influencing tumor growth and progression. We find that human primary colorectal tumor and stromal cells exhibit polyfunctional heterogeneity in the combinations and magnitudes of secretions for these chemokines. In cell lines, we observe similar variance: phenotypes observed in bulk can be largely absent among the majority of single cells, and discordances exist between secretory states measured and gene expression for these chemokines among single cells. Together, these measures suggest secretory states among tumor cells are complex and can evolve dynamically. Most importantly, this study reveals new insight into the intratumoral phenotypic heterogeneity of human primary tumors.

Alarm management in a single-patient room intensive care units

NARCIS (Netherlands)

van Pul, C.; Joshi, R.; Dijkman, W.; van de Mortel, H.; Mohns, T.; Andriessen, P.; Chen, Wei; Carlos Augusto, Juan; Seoane, Fernando; Lehocki, Fedor; Wolf, Klaus-Henderik; Arends, Johan; Ungureanu, Constantin; Wichert, Reiner

2015-01-01

An international trend in intensive care is the shift from open, bay area intensive care units towards single-patient room care, since this is considered optimal for patient healing and family privacy. However, in the intensive care setting, an increasing number of devices and parameters are being

Mobile exhibition in Mexico

Energy Technology Data Exchange (ETDEWEB)

NONE

1960-04-15

Since January this year, a mobile atomic energy exhibition has been touring the principal cities of Mexico. In organizing this exhibition, the National Nuclear Energy Commission of Mexico was assisted by the International Atomic Energy Agency which has placed its second mobile radioisotope laboratory at the disposal of the Mexican authorities. In many States of the Republic, the visit of the mobile laboratory has given a powerful impetus to atomic training and research. Universities have made use of the laboratory for the training of young scientists in the basic isotope techniques. As a sequel to the work initiated with its aid, some universities are planning to start regular training courses in this field. The laboratory, which is a gift to the Agency from the United States, has been put to its first assignment in Mexico. It will shortly be sent to Argentina for a period of six months for use in training courses. IAEA's first mobile radioisotope unit, also donated by the United States, has been used for training purposes in Austria, the Federal Republic of Germany, Greece and Yugoslavia, and has now been sent to the Far East

Mobile exhibition in Mexico

International Nuclear Information System (INIS)

1960-01-01

Since January this year, a mobile atomic energy exhibition has been touring the principal cities of Mexico. In organizing this exhibition, the National Nuclear Energy Commission of Mexico was assisted by the International Atomic Energy Agency which has placed its second mobile radioisotope laboratory at the disposal of the Mexican authorities. In many States of the Republic, the visit of the mobile laboratory has given a powerful impetus to atomic training and research. Universities have made use of the laboratory for the training of young scientists in the basic isotope techniques. As a sequel to the work initiated with its aid, some universities are planning to start regular training courses in this field. The laboratory, which is a gift to the Agency from the United States, has been put to its first assignment in Mexico. It will shortly be sent to Argentina for a period of six months for use in training courses. IAEA's first mobile radioisotope unit, also donated by the United States, has been used for training purposes in Austria, the Federal Republic of Germany, Greece and Yugoslavia, and has now been sent to the Far East

Structure predictions of two Bauhinia variegata lectins reveal patterns of C-terminal properties in single chain legume lectins.

Science.gov (United States)

Moreira, Gustavo M S G; Conceição, Fabricio R; McBride, Alan J A; Pinto, Luciano da S

2013-01-01

Bauhinia variegata lectins (BVL-I and BVL-II) are single chain lectins isolated from the plant Bauhinia variegata. Single chain lectins undergo post-translational processing on its N-terminal and C-terminal regions, which determines their physiological targeting, carbohydrate binding activity and pattern of quaternary association. These two lectins are isoforms, BVL-I being highly glycosylated, and thus far, it has not been possible to determine their structures. The present study used prediction and validation algorithms to elucidate the likely structures of BVL-I and -II. The program Bhageerath-H was chosen from among three different structure prediction programs due to its better overall reliability. In order to predict the C-terminal region cleavage sites, other lectins known to have this modification were analysed and three rules were created: (1) the first amino acid of the excised peptide is small or hydrophobic; (2) the cleavage occurs after an acid, polar, or hydrophobic residue, but not after a basic one; and (3) the cleavage spot is located 5-8 residues after a conserved Leu amino acid. These rules predicted that BVL-I and -II would have fifteen C-terminal residues cleaved, and this was confirmed experimentally by Edman degradation sequencing of BVL-I. Furthermore, the C-terminal analyses predicted that only BVL-II underwent α-helical folding in this region, similar to that seen in SBA and DBL. Conversely, BVL-I and -II contained four conserved regions of a GS-I association, providing evidence of a previously undescribed X4+unusual oligomerisation between the truncated BVL-I and the intact BVL-II. This is the first report on the structural analysis of lectins from Bauhinia spp. and therefore is important for the characterisation C-terminal cleavage and patterns of quaternary association of single chain lectins.

Heterogeneity of rabbit endogenous pyrogens is not attributable to glycosylated variants of a single polypeptide chain.

OpenAIRE

Murphy, P A; Cebula, T A; Windle, B E

1981-01-01

Rabbit endogenous pyrogens were of about the same molecular size, but showed considerable heterogeneity of their isoelectric points. We attempted to show that this heterogeneity was attributable to variable glycosylation of a single polypeptide chain. When peritoneal exudate cells were stimulated to make pyrogens in the presence of 2-deoxy-D-glucose, there was a relatively trivial suppression of pyrogen release, and analysis by isoelectric focusing showed parallel inhibition of secretion of a...

IG and TR single chain fragment variable (scFv) sequence analysis: a new advanced functionality of IMGT/V-QUEST and IMGT/HighV-QUEST.

Science.gov (United States)

Giudicelli, Véronique; Duroux, Patrice; Kossida, Sofia; Lefranc, Marie-Paule

2017-06-26

IMGT®, the international ImMunoGeneTics information system® ( http://www.imgt.org ), was created in 1989 in Montpellier, France (CNRS and Montpellier University) to manage the huge and complex diversity of the antigen receptors, and is at the origin of immunoinformatics, a science at the interface between immunogenetics and bioinformatics. Immunoglobulins (IG) or antibodies and T cell receptors (TR) are managed and described in the IMGT® databases and tools at the level of receptor, chain and domain. The analysis of the IG and TR variable (V) domain rearranged nucleotide sequences is performed by IMGT/V-QUEST (online since 1997, 50 sequences per batch) and, for next generation sequencing (NGS), by IMGT/HighV-QUEST, the high throughput version of IMGT/V-QUEST (portal begun in 2010, 500,000 sequences per batch). In vitro combinatorial libraries of engineered antibody single chain Fragment variable (scFv) which mimic the in vivo natural diversity of the immune adaptive responses are extensively screened for the discovery of novel antigen binding specificities. However the analysis of NGS full length scFv (~850 bp) represents a challenge as they contain two V domains connected by a linker and there is no tool for the analysis of two V domains in a single chain. The functionality "Analyis of single chain Fragment variable (scFv)" has been implemented in IMGT/V-QUEST and, for NGS, in IMGT/HighV-QUEST for the analysis of the two V domains of IG and TR scFv. It proceeds in five steps: search for a first closest V-REGION, full characterization of the first V-(D)-J-REGION, then search for a second V-REGION and full characterization of the second V-(D)-J-REGION, and finally linker delimitation. For each sequence or NGS read, positions of the 5'V-DOMAIN, linker and 3'V-DOMAIN in the scFv are provided in the 'V-orientated' sense. Each V-DOMAIN is fully characterized (gene identification, sequence description, junction analysis, characterization of mutations and amino

Exhibition: Linus Pauling and the Twentieth Century

CERN Document Server

2003-01-01

On April 28 the exhibit Linus Pauling and the Twentieth Century organised by UNIDIR (United Nations Institute for Disarmament Research) and SGI (Soka Gakkai International) as well as with the contributions of CERN and the University of Geneva, opened at the United Nations Office of Geneva. Linus Pauling is the only person to date to have won two unshared Nobel Prizes: Chemistry in 1954 and Peace in 1962. The first was awarded for his landmark research on the nature of the chemical bond and its application in understanding the structure of complex substances. The second one acknowledged his courageous protest against atmospheric nuclear testing and his championship of international peace. The exhibit, for audience of all ages, traces seven decades of Linus Pauling's life and influence on the 20th century. Before starting its European tour at the UNESCO headquarters in Paris, the exhibit opened in 1998 in San Francisco and then travelled within the United-States and to Japan with an attendance of more than one...

Exhibition: Linus Pauling and the Twentieth Century

CERN Document Server

2003-01-01

On April 28 the exhibit Linus Pauling and the Twentieth Century organised by UNIDIR (United Nations Institute for Disarmament Research) and SGI (Soka Gakkai International) as well as with the contributions of CERN and the University of Geneva, opens at the United Nations Office of Geneva. Linus Pauling is the only person to date to have won two unshared Nobel Prizes: Chemistry in 1954 and Peace in 1962. The first was awarded for his landmark research on the nature of the chemical bond and its application in understanding the structure of complex substances. The second one acknowledged his courageous protest against atmospheric nuclear testing and his championship of international peace. The exhibit, for all ages' audiences, traces seven decades of Linus Pauling's life and influence on the 20th century. Before starting its European tour at the UNESCO headquarters in Paris, the exhibit opened in 1998 in San Francisco and then travelled within the United-States and to Japan with an attendance of more than one m...

Recruitment of single human low-threshold motor units with increasing loads at different muscle lengths.

Science.gov (United States)

McNulty, P A; Cresswell, A G

2004-06-01

We investigated the recruitment behaviour of low threshold motor units in flexor digitorum superficialis by altering two biomechanical constraints: the load against which the muscle worked and the initial muscle length. The load was increased using isotonic (low load), loaded dynamic (intermediate load) and isometric (high load) contractions in two studies. The initial muscle position reflected resting muscle length in series A, and a longer length with digit III fully extended in series B. Intramuscular EMG was recorded from 48 single motor units in 10 experiments on five healthy subjects, 21 units in series A and 27 in series B, while subjects performed ramp up, hold and ramp down contractions. Increasing the load on the muscle decreased the force, displacement and firing rate of single motor units at recruitment at shorter muscle lengths (Precruitment pattern was observed between loaded dynamic and isotonic contractions, but not between isometric and loaded dynamic contractions. Thus, the recruitment properties of single motor units in human flexor digitorum superficialis are sensitive to changes in both imposed external loads and the initial length of the muscle.

A novel anti-alpha-fetoprotein single-chain variable fragment displays anti-tumor effects in HepG2 cells as a single agent or in combination with paclitaxel.

Science.gov (United States)

Ji, Xiaonan; Shen, Yanli; Sun, Hao; Gao, Xiangdong

2016-08-01

Human hepatocellular carcinoma (HCC) has a high rate of tumor recurrence and metastasis, resulting in shortened survival time. The function of alpha-fetoprotein (AFP) as a regulatory factor in the growth of HCC cells has been well defined. The aim of this study was to investigate the use of a novel AFP-specific single-chain variable fragment that blocked AFP and inhibited HCC cell growth. The results indicated that the anti-AFP single-chain variable fragment (scFv) induced growth inhibition of AFP-expressing HCC cell lines in vitro through induction of G1 cell cycle arrest and apoptosis. The mechanism of apoptosis probably involved with blocking AFP internalization and regulation of the PTEN/PI3K/Akt signaling network. Moreover, the anti-AFP-scFv also effectively sensitized the HepG2 cells to paclitaxel (PTX) at a lower concentration. The combination effect of PTX and anti-AFP-scFv displayed a synergistic effect on HepG2 cells both in vitro and in vivo. Our results demonstrated that targeting AFP by specific antibodies has potential immunotherapeutic efficacy in human HCC.

Introduction of a point mutation into an HLA class I single-chain trimer induces enhancement of CTL priming and antitumor immunity

Directory of Open Access Journals (Sweden)

Masanori Matsui

2014-01-01

Full Text Available We previously discovered one particular HLA-A*02:01 mutant that enhanced peptide-specific cytotoxic T lymphocyte (CTL recognition in vitro compared to wild-type HLA-A*02:01. This mutant contains a single amino acid substitution from histidine to leucine at position 74 (H74L that is located in the peptide-binding groove. To investigate the effect of the H74L mutation on the in vivo CTL priming, we took advantage of the technology of the HLA class I single-chain trimer (SCT in which three components involving a peptide, β2 microglobulin and the HLA class I heavy chain are joined together via flexible linkers. We generated recombinant adenovirus expressing SCT comprised influenza A matrix protein (FMP-derived peptide, β2 microglobulin and the H74L heavy chain. HLA-A*02:01 transgenic mice were immunized with the adenovirus, and the induction of peptide-specific CTLs and antitumor immunity was investigated. It was clearly shown that the H74L mutation enabled the HLA-A*02:01 SCT molecule to dramatically enhance both in vivo priming of FMP-specific CTLs and protection against a lethal challenge of tumor cells expressing FMP. These data present the first evidence that a simple point mutation in the HLA class I heavy chain of SCT is beneficial for improving CTL-based immunotherapy and prophylaxis to control tumors.

77 FR 31420 - Culturally Significant Objects Imported for Exhibition

Science.gov (United States)

2012-05-25

... also determine that the exhibition or display of the exhibit objects at The Museum of Modern Art, New...: Game Plan'' imported from abroad for temporary exhibition within the United States, are of cultural...

Research on collaborative innovation mechanism of green construction supply chain based on united agency

Science.gov (United States)

Zhang, Min; He, Weiyi

2018-06-01

Under the guidance of principal-agent theory and modular theory, the collaborative innovation of green technology-based companies, design contractors and project builders based on united agency will provide direction for the development of green construction supply chain in the future. After analyzing the existing independent agencies, this paper proposes the industry-university-research bilateral collaborative innovation network architecture and modularization with the innovative function of engineering design in the context of non-standard transformation interfaces, analyzes the innovation responsibility center, and gives some countermeasures and suggestions to promote the performance of bilateral cooperative innovation network.

A cyclam core dendrimer containing dansyl and oligoethylene glycol chains in the branches: protonation and metal coordination.

Science.gov (United States)

Branchi, Barbara; Ceroni, Paola; Bergamini, Giacomo; Balzani, Vincenzo; Maestri, Mauro; van Heyst, Jeroen; Lee, Sang-Kyu; Luppertz, Friedhelm; Vögtle, Fritz

2006-12-04

We have synthesized a dendrimer (1) consisting of a 1,4,8,11-tetraazacyclotetradecane (cyclam) core, appended with four benzyl substituents that carry, in the 3- and 5-positions, a dansyl amide derivative (of type 2), in which the amide hydrogen is replaced by a benzyl unit that carries an oligoethylene glycol chain in the 3- and 5-positions. All together, the dendrimer contains 16 potentially luminescent moieties (eight dansyl- and eight dimethoxybenzene-type units) and three distinct types of multivalent sites that, in principle, can be protonated or coordinated to metal ions (the cyclam nitrogen atoms, the amine moieties of the eight dansyl units, and the 16 oligoethylene glycol chains). We have studied the absorption and luminescence properties of 1, 2, and 3 in acetonitrile and the changes taking place upon titration with acid and a variety of divalent (Co2+, Ni2+, Cu2+, Zn2+), and trivalent (Nd3+, Eu3+, Gd3+) metal ions as triflate and/or nitrate salts. The results obtained show that: 1) double protonation of the cyclam ring takes place before protonation of the dansyl units; 2) the oligoethylene glycol chains do not interfere with protonation of the cyclam core and the dansyl units in the ground state, but affect the luminescence of the protonated dansyl units; 3) the first equivalent of metal ion is coordinated by the cyclam core; 4) the interaction of the resulting cyclam complex with the appended dansyl units depends on the nature of the metal ion; 5) coordination of metal ions by the dansyl units follows at high metal-ion concentrations; 6) the effect of the metal ion depends on the nature of the counterion. This example demonstrates that dendrimers may exhibit complete functionality resulting from the integration of the specific properties of their component units.

Myosin heavy chain composition of single fibres from m. biceps brachii of male body builders

DEFF Research Database (Denmark)

Klitgaard, H; Zhou, M.-Y.; Richter, Erik

1990-01-01

The myosin heavy chain (MHC) composition of single fibres from m. biceps brachii of young sedentary men (28 +/- 0.4 years, mean +/- SE, n = 4) and male body builders (25 +/- 2.0 years, n = 4) was analysed with a sensitive one-dimensional electrophoretic technique. Compared with sedentary men...... expression of MHC isoforms within histochemical type II fibres of human skeletal muscle with body building. Furthermore, in human skeletal muscle differences in expression of MHC isoforms may not always be reflected in the traditional histochemical classification of types I, IIa, IIb and IIc fibres....

Tracking Single Units in Chronic, Large Scale, Neural Recordings for Brain Machine Interface Applications

Directory of Open Access Journals (Sweden)

Ahmed eEleryan

2014-07-01

Full Text Available In the study of population coding in neurobiological systems, tracking unit identity may be critical to assess possible changes in the coding properties of neuronal constituents over prolonged periods of time. Ensuring unit stability is even more critical for reliable neural decoding of motor variables in intra-cortically controlled brain-machine interfaces (BMIs. Variability in intrinsic spike patterns, tuning characteristics, and single-unit identity over chronic use is a major challenge to maintaining this stability, requiring frequent daily calibration of neural decoders in BMI sessions by an experienced human operator. Here, we report on a unit-stability tracking algorithm that efficiently and autonomously identifies putative single-units that are stable across many sessions using a relatively short duration recording interval at the start of each session. The algorithm first builds a database of features extracted from units' average spike waveforms and firing patterns across many days of recording. It then uses these features to decide whether spike occurrences on the same channel on one day belong to the same unit recorded on another day or not. We assessed the overall performance of the algorithm for different choices of features and classifiers trained using human expert judgment, and quantified it as a function of accuracy and execution time. Overall, we found a trade-off between accuracy and execution time with increasing data volumes from chronically implanted rhesus macaques, with an average of 12 seconds processing time per channel at ~90% classification accuracy. Furthermore, 77% of the resulting putative single-units matched those tracked by human experts. These results demonstrate that over the span of a few months of recordings, automated unit tracking can be performed with high accuracy and used to streamline the calibration phase during BMI sessions.

Free vibration analysis of linear particle chain impact damper

Science.gov (United States)

Gharib, Mohamed; Ghani, Saud

2013-11-01

Impact dampers have gained much research interest over the past decades that resulted in several analytical and experimental studies being conducted in that area. The main emphasis of such research was on developing and enhancing these popular passive control devices with an objective of decreasing the three parameters of contact forces, accelerations, and noise levels. To that end, the authors of this paper have developed a novel impact damper, called the Linear Particle Chain (LPC) impact damper, which mainly consists of a linear chain of spherical balls of varying sizes. The LPC impact damper was designed utilizing the kinetic energy of the primary system through placing, in the chain arrangement, a small-sized ball between each two large-sized balls. The concept of the LPC impact damper revolves around causing the small-sized ball to collide multiple times with the larger ones upon exciting the primary system. This action is believed to lead to the dissipation of part of the kinetic energy at each collision with the large balls. This paper focuses on the outcome of studying the free vibration of a single degree freedom system that is equipped with the LPC impact damper. The proposed LPC impact damper is validated by means of comparing the responses of a single unit conventional impact damper with those resulting from the LPC impact damper. The results indicated that the latter is considerably more efficient than the former impact damper. In order to further investigate the LPC impact damper effective number of balls and efficient geometry when used in a specific available space in the primary system, a parametric study was conducted and its result is also explained herein. Single unit impact damper [14-16]. Multiunit impact damper [17,18]. Bean bag impact damper [19,20]. Particle/granular impact damper [21,23,22]. Resilient impact damper [24]. Buffered impact damper [25-27]. Multiunit impact damper consists of multiple masses instead of a single mass. This

Quantum phase transitions in spin-1 X X Z chains with rhombic single-ion anisotropy

Science.gov (United States)

Ren, Jie; Wang, Yimin; You, Wen-Long

2018-04-01

We explore numerically the inverse participation ratios in the ground state of one-dimensional spin-1 X X Z chains with the rhombic single-ion anisotropy. By employing the techniques of density-matrix renormalization group, effects of the rhombic single-ion anisotropy on various information theoretical measures are investigated, such as the fidelity susceptibility, the quantum coherence, and the entanglement entropy. Their relations with the quantum phase transitions are also analyzed. The phase transitions from the Y -Néel phase to the large-Ex or the Haldane phase can be well characterized by the fidelity susceptibility. The second-order derivative of the ground-state energy indicates all the transitions are of second order. We also find that the quantum coherence, the entanglement entropy, the Schmidt gap, and the inverse participation ratios can be used to detect the critical points of quantum phase transitions. Results drawn from these quantum information observables agree well with each other. Finally we provide a ground-state phase diagram as functions of the exchange anisotropy Δ and the rhombic single-ion anisotropy E .

Business integration unit (BIU adapter for industrial global value chain on the web

Directory of Open Access Journals (Sweden)

Adel Ghannam

2016-05-01

Full Text Available Today's manufacturing enterprises rarely live in isolation. They need to be connected in order to create products from which a group of enterprises, called global-value-chain (GVC, can derive value. Service-oriented architecture (SOA and event-driven architecture (EDA are two different paradigms that address complex integration challenges. Enterprise service bus (ESB allows for the implementation of both the SOA and the EDA concepts. This paper addresses the development of an enterprise service bus (ESB to grant the operation of GVC. A proposed business-integrator-unit (BIU is designed to be plugged in each enterprise system. The BIU contains a “business collaboration map configurator” that allows real time allocation of roles to members’ enterprises.

Charge distribution in an two-chain dual model

International Nuclear Information System (INIS)

Fialkowski, K.; Kotanski, A.

1983-01-01

Charge distributions in the multiple production processes are analysed using the dual chain model. A parametrisation of charge distributions for single dual chains based on the νp and anti vp data is proposed. The rapidity charge distributions are then calculated for pp and anti pp collisions and compared with the previous calculations based on the recursive cascade model of single chains. The results differ at the SPS collider energies and in the energy dependence of the net forward charge supplying the useful tests of the dual chain model. (orig.)

Realities of Supply Chain Collaboration

NARCIS (Netherlands)

Kampstra, R.P.; Ashayeri, J.; Gattorna, J.

2006-01-01

Successful supply chain collaboration (SCC) practices are rather exceptional, yet collaboration is believed to be the single most pressing need in supply chain management.In this paper we discuss the realities of SCC, present prerequisites for the collaboration process, indicate where the process

Phase transitions in single macromolecules: Loop-stretch transition versus loop adsorption transition in end-grafted polymer chains

Science.gov (United States)

Zhang, Shuangshuang; Qi, Shuanhu; Klushin, Leonid I.; Skvortsov, Alexander M.; Yan, Dadong; Schmid, Friederike

2018-01-01

We use Brownian dynamics simulations and analytical theory to compare two prominent types of single molecule transitions. One is the adsorption transition of a loop (a chain with two ends bound to an attractive substrate) driven by an attraction parameter ɛ and the other is the loop-stretch transition in a chain with one end attached to a repulsive substrate, driven by an external end-force F applied to the free end. Specifically, we compare the behavior of the respective order parameters of the transitions, i.e., the mean number of surface contacts in the case of the adsorption transition and the mean position of the chain end in the case of the loop-stretch transition. Close to the transition points, both the static behavior and the dynamic behavior of chains with different length N are very well described by a scaling ansatz with the scaling parameters (ɛ - ɛ*)Nϕ (adsorption transition) and (F - F*)Nν (loop-stretch transition), respectively, where ϕ is the crossover exponent of the adsorption transition and ν is the Flory exponent. We show that both the loop-stretch and the loop adsorption transitions provide an exceptional opportunity to construct explicit analytical expressions for the crossover functions which perfectly describe all simulation results on static properties in the finite-size scaling regime. Explicit crossover functions are based on the ansatz for the analytical form of the order parameter distributions at the respective transition points. In contrast to the close similarity in equilibrium static behavior, the dynamic relaxation at the two transitions shows qualitative differences, especially in the strongly ordered regimes. This is attributed to the fact that the surface contact dynamics in a strongly adsorbed chain is governed by local processes, whereas the end height relaxation of a strongly stretched chain involves the full spectrum of Rouse modes.

Graph state generation with noisy mirror-inverting spin chains

International Nuclear Information System (INIS)

Clark, Stephen R; Klein, Alexander; Bruderer, Martin; Jaksch, Dieter

2007-01-01

We investigate the influence of noise on a graph state generation scheme which exploits a mirror inverting spin chain. Within this scheme the spin chain is used repeatedly as an entanglement bus (EB) to create multi-partite entanglement. The noise model we consider comprises of each spin of this EB being exposed to independent local noise which degrades the capabilities of the EB. Here we concentrate on quantifying its performance as a single-qubit channel and as a mediator of a two-qubit entangling gate, since these are basic operations necessary for graph state generation using the EB. In particular, for the single-qubit case we numerically calculate the average channel fidelity and whether the channel becomes entanglement breaking, i.e. expunges any entanglement the transferred qubit may have with other external qubits. We find that neither local decay nor dephasing noise cause entanglement breaking. This is in contrast to local thermal and depolarizing noise where we determine a critical length and critical noise coupling, respectively, at which entanglement breaking occurs. The critical noise coupling for local depolarizing noise is found to exhibit a power-law dependence on the chain length. For two-qubits we similarly compute the average gate fidelity and whether the ability for this gate to create entanglement is maintained. The concatenation of these noisy gates for the construction of a five-qubit linear cluster state and a Greenberger-Horne-Zeilinger state indicates that the level of noise that can be tolerated for graph state generation is tightly constrained

Three Cyanide-Bridged One-Dimensional Single Chain Co"I"I"I-Mn"I"I Complexes: Rational Design, Synthesis, Crystal Structures and Magnetic Properties

International Nuclear Information System (INIS)

Zhang, Daopeng; Zhao, Zengdian; Wang, Ping; Chen, Xia

2012-01-01

Two pyridinecarboxamide dicyanidecobalt(III) building blocks and two mononuclear seven-coordinated macrocycle manganese(II) compounds have been rationally selected to assemble cyanide-bridged heterobimetallic complexes, resulting in three cyanide-bridged Co"I"I"I-Mn"I"I complexes. Single X-ray diffraction analysis show that these complexes {[Mn(L"1)][Co(bpb)]}ClO_4·CH_3OH·0.5H_2O (1), {[Mn(L"2)][Co(bpb)]}ClO_4·0.5CH_3OH (2) and {[Mn(L"1)][Cobpmb]}ClO_4·H_2O (3) (L"1 = 3,6-diazaoctane-1,8-diamine, L"2 = 3,6-dioxaoctano-1,8- diamine: bpb"2"- = 1,2-bis(pyridine-2-carboxamido)benzenate, bpmb"2"- = 1,2-bis(pyridine-2-carboxamido)-4- methyl-benzenate) all present predictable one-dimensional single chain structures. The molecular structures of these one-dimensional complexes consists of alternating units of [Mn(L)]"2"+ (L = L"1 or L"2) and [Co(L')(CN)_2]"- (L' = bpb"2"-, or bpmb"2"-), forming a cyanide-bridged cationic polymeric chain with free ClO_4"- as the balance anion. The coordination geometry of manganese(II) ion in the three one-dimensional complexes is a slightly distorted pentagonal-bipyrimidal with two cyanide nitrogen atoms at the trans positions and N_5 or N_3O_2 coordinating mode at the equatorial plane from ligand L"1 or L"2. Investigation over magnetic properties of these complexes reveals that the very weak magnetic coupling between neighboring Mn(II) ions connected by the diamagnetic dicyanidecobalt(III) building block. A best-fit to the magnetic susceptibility of complex 1 leads to the magnetic coupling constants J = .0.084(3) cm"-"1

Quantum communication and state transfer in spin chains

International Nuclear Information System (INIS)

Van der Jeugt, Joris

2011-01-01

We investigate the time evolution of a single spin excitation state in certain linear spin chains, as a model for quantum communication. We consider first the simplest possible spin chain, where the spin chain data (the nearest neighbour interaction strengths and the magnetic field strengths) are constant throughout the chain. The time evolution of a single spin state is determined, and this time evolution is illustrated by means of an animation. Some years ago it was discovered that when the spin chain data are of a special form so-called perfect state transfer takes place. These special spin chain data can be linked to the Jacobi matrix entries of Krawtchouk polynomials or dual Hahn polynomials. We discuss here the case related to Krawtchouk polynomials, and illustrate the possibility of perfect state transfer by an animation showing the time evolution of the spin chain from an initial single spin state. Very recently, these ideas were extended to discrete orthogonal polynomials of q-hypergeometric type. Here, a remarkable result is a new analytic model where perfect state transfer is achieved: this is when the spin chain data are related to the Jacobi matrix of q-Krawtchouk polynomials. This case is discussed here, and again illustrated by means of an animation.

Ground state properties of a spin chain within Heisenberg model with a single lacking spin site

International Nuclear Information System (INIS)

Mebrouki, M.

2011-01-01

The ground state and first excited state energies of an antiferromagnetic spin-1/2 chain with and without a single lacking spin site are computed using exact diagonalization method, within the Heisenberg model. In order to keep both parts of a spin chain with a lacking site connected, next nearest neighbors interactions are then introduced. Also, the Density Matrix Renormalization Group (DMRG) method is used, to investigate ground state energies of large system sizes; which permits us to inquire about the effect of large system sizes on energies. Other quantum quantities such as fidelity and correlation functions are also studied and compared in both cases. - Research highlights: → In this paper we compute ground state and first excited state energies of a spin chain with and without a lacking spin site. The next nearest neighbors are introduced with the antiferromagnetic Heisenberg spin-half. → Exact diagonalization is used for small systems, where DMRG method is used to compute energies for large systems. Other quantities like quantum fidelity and correlation are also computed. → Results are presented in figures with comments. → E 0 /N is computed in a function of N for several values of J 2 and for both systems. First excited energies are also investigated.

Observation of a commensurate array of flux chains in tilted flux lattices in Bi-Sr-Ca-Cu-O single crystals

International Nuclear Information System (INIS)

Bolle, C.A.; Gammel, P.L.; Grier, D.G.; Murray, C.A.; Bishop, D.J.; Mitzi, D.B.; Kapitulnik, A.

1991-01-01

We report the observation of a novel flux-lattice structure, a commensurate array of flux-line chains. Our experiments consist of the magnetic decoration of the flux lattices in single crystals of Ba-Sr-Ca-Cu-O where the magnetic field is applied at an angle with respect to the conducting planes. For a narrow range of angles, the equilibrium structure is one with uniformly spaced chains with a higher line density of vortices than the background lattice. Our observations are in qualitative agreement with theories which suggest that, in strongly anisotropic materials the vortices develop an attractive interaction in tilted magnetic fields

Calculation of single chain cellulose elasticity using fully atomistic modeling

Science.gov (United States)

Xiawa Wu; Robert J. Moon; Ashlie Martini

2011-01-01

Cellulose nanocrystals, a potential base material for green nanocomposites, are ordered bundles of cellulose chains. The properties of these chains have been studied for many years using atomic-scale modeling. However, model predictions are difficult to interpret because of the significant dependence of predicted properties on model details. The goal of this study is...

Realization of a four-step molecular switch in scanning tunneling microscope manipulation of single chlorophyll-a molecules

Science.gov (United States)

Iancu, Violeta; Hla, Saw-Wai

2006-01-01

Single chlorophyll-a molecules, a vital resource for the sustenance of life on Earth, have been investigated by using scanning tunneling microscope manipulation and spectroscopy on a gold substrate at 4.6 K. Chlorophyll-a binds on Au(111) via its porphyrin unit while the phytyl-chain is elevated from the surface by the support of four CH3 groups. By injecting tunneling electrons from the scanning tunneling microscope tip, we are able to bend the phytyl-chain, which enables the switching of four molecular conformations in a controlled manner. Statistical analyses and structural calculations reveal that all reversible switching mechanisms are initiated by a single tunneling-electron energy-transfer process, which induces bond rotation within the phytyl-chain. PMID:16954201

77 FR 31909 - Culturally Significant Objects Imported for Exhibition

Science.gov (United States)

2012-05-30

... exhibition ``50th Anniversary Remembrance of the Tragedy at Orly,'' imported from abroad by the High Museum of Art for temporary exhibition within the United States, is of cultural significance. The object is... exhibition or display of the exhibit object at the High Museum of Art in Atlanta, Georgia from on or about...

Connecting Structural and Transport Properties of Ionic Liquids with Cationic Oligoether Chains

Energy Technology Data Exchange (ETDEWEB)

Lall-Ramnarine, Sharon I.; Zhao, Man; Rodriguez, Chanele; Fernandez, Rahonel; Zmich, Nicole; Fernandez, Eddie D.; Dhiman, Surajdevprakash B.; Castner, Edward W.; Wishart, James F.

2017-01-01

X-ray diffraction and molecular dynamics simulations were used to probe the structures of two families of ionic liquids containing oligoether tails on the cations. Imidazolium and pyrrolidinium bis(trifluoromethylsulfonyl)amide ILs with side chains ranging from 4 to 10 atoms in length, including both linear alkyl and oligo-ethylene oxide tails, were prepared. Their physical properties, such as viscosity, conductivity and thermal profile, were measured and compared for systematic trends. Consistent with earlier literature, a single ether substituent substantially decreases the viscosity of pyrrolidinium and imidazolium ILs compared to their alkyl congeners. Remarkably, as the number of ether units in the pyrrolidinium ILs increases there is hardly any increase in the viscosity, in contrast to alkylpyrrolidinium ILs where the viscosity increases steadily with chain length. Viscosities of imidazolium ether ILs increase with chain length but always remain well below their alkyl congeners. To complement the experimentally determined properties, molecular dynamics simulations were run on the two ILs with the longest ether chains. The results point to specific aspects that could be useful for researchers designing ILs for specific applications.

Nurses' Perceptions of Pediatric Intensive Care Unit Environment and Work Experience After Transition to Single-Patient Rooms.

Science.gov (United States)

Kudchadkar, Sapna R; Beers, M Claire; Ascenzi, Judith A; Jastaniah, Ebaa; Punjabi, Naresh M

2016-09-01

The architectural design of the pediatric intensive care unit may play a major role in optimizing the environment to promote patients' sleep while improving stress levels and the work experience of critical care nurses. To examine changes in nurses' perceptions of the environment of a pediatric critical care unit for promotion of patients' sleep and the nurses' work experience after a transition from multipatient rooms to single-patient rooms. A cross-sectional survey of nurses was conducted before and after the move to a new hospital building in which all rooms in the pediatric critical care unit were single-patient rooms. Nurses reported that compared with multipatient rooms, single-patient private rooms were more conducive to patients sleeping well at night and promoted a more normal sleep-wake cycle (P noise in single-patient rooms (33%) than in multipatient rooms (79%; P pediatric intensive care unit environment for promoting patients' sleep and the nurses' own work experience. ©2016 American Association of Critical-Care Nurses.

Expression and characterization of recombinant single-chain salmon class I MHC fused with beta2-microglobulin with biological activity

DEFF Research Database (Denmark)

Zhao, Heng; Stet, René J M; Skjødt, Karsten

2008-01-01

Heterodimeric class I major histocompatibility complex (MHC) molecules consist of a putative 45-kDa heavy chain and a 12-kDa beta2-microglobulin (beta2m) light chain. The knowledge about MHC genes in Atlantic salmon accumulated during the last decade has allowed us to generate soluble and stable ...... MHC class I molecules with biological activity. We report here the use of a bacterial expression system to produce the recombinant single-chain MHC molecules based on a specific allele Sasa-UBA*0301. This particular allele was selected because previous work has shown its association...... antibodies were successfully produced against both the MHC class I heavy chain and beta(2)m, and showed binding to the recombinant molecule. The recombinant complex Sasabeta2mUBA*0301 was expressed and isolated; the production was scaled up by adjusting to its optimal conditions. Subsequently......, the recombinant proteins were purified by affinity chromatography using mAb against beta2m and alpha3. Eluates were analyzed by Western blot and refolded by the removal of denaturant. The correct folding was confirmed by measuring its binding capacity against mAb produced to recognize the native form of MHC...

Molecular characterization of medium-chain acyl-CoA dehydrogenase (MCAD) deficiency

DEFF Research Database (Denmark)

Gregersen, N; Andresen, B S; Bross, P

1991-01-01

. All clones sequenced from the patient exhibited a single base substitution from adenine (A) to guanine (G) at position 985 in the MCAD cDNA as the only consistent base-variation compared with control cDNA. In contrast, the parents contained cDNA with the normal and the mutated sequence, revealing......A series of experiments has established the molecular defect in the medium-chain acyl-coenzyme A (CoA) dehydrogenase (MCAD) gene in a family with MCAD deficiency. Demonstration of intra-mitochondrial mature MCAD indistinguishable in size (42.5-kDa) from control MCAD, and of mRNA with the correct...... size of 2.4 kb, indicated a point-mutation in the coding region of the MCAD gene to be disease-causing. Consequently, cloning and DNA sequencing of polymerase chain reaction (PCR) amplified complementary DNA (cDNA) from messenger RNA of fibroblasts from the patient and family members were performed...

The Tax-Efficient Supply Chain

DEFF Research Database (Denmark)

Webber, Stuart

2011-01-01

Many multinational enterprises are restructuring supply chains to reduce their cost structures. As trade barriers fall and communications technologies improve, it has become easier and more cost-effective to manage business operations across international borders. This has motivated businesses...... practitioners in France, South Africa, Switzerland, Mexico, Argentina, and the United States. Companies are restructuring their supply chains and simultaneously reducing their income tax obligations. This article demonstrates that MNEs should link income tax and supply chain considerations when restructuring...... their supply chains, and they should endeavor to maximize net income when doing so. This recommendation differs from the great majority of supply chain literature, which has generally recommended that businesses seek to minimize pretax costs. One of the most important activities for both supply chain and tax...

Boosting the ambipolar performance of solution-processable polymer semiconductors via hybrid side-chain engineering.

Science.gov (United States)

Lee, Junghoon; Han, A-Reum; Yu, Hojeong; Shin, Tae Joo; Yang, Changduk; Oh, Joon Hak

2013-06-26

Ambipolar polymer semiconductors are highly suited for use in flexible, printable, and large-area electronics as they exhibit both n-type (electron-transporting) and p-type (hole-transporting) operations within a single layer. This allows for cost-effective fabrication of complementary circuits with high noise immunity and operational stability. Currently, the performance of ambipolar polymer semiconductors lags behind that of their unipolar counterparts. Here, we report on the side-chain engineering of conjugated, alternating electron donor-acceptor (D-A) polymers using diketopyrrolopyrrole-selenophene copolymers with hybrid siloxane-solubilizing groups (PTDPPSe-Si) to enhance ambipolar performance. The alkyl spacer length of the hybrid side chains was systematically tuned to boost ambipolar performance. The optimized three-dimensional (3-D) charge transport of PTDPPSe-Si with pentyl spacers yielded unprecedentedly high hole and electron mobilities of 8.84 and 4.34 cm(2) V(-1) s(-1), respectively. These results provide guidelines for the molecular design of semiconducting polymers with hybrid side chains.

19 CFR 212.11 - Net worth exhibit.

Science.gov (United States)

2010-04-01

... 19 Customs Duties 3 2010-04-01 2010-04-01 false Net worth exhibit. 212.11 Section 212.11 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE IMPLEMENTATION OF THE EQUAL ACCESS TO JUSTICE ACT Information Required From Applicants § 212.11 Net worth exhibit...

2006 Land and Maritime Supply Chains Business Conference and Exhibition

Science.gov (United States)

2006-08-30

Clifford G. Scott, SC, USN, Unit Chief, Electronics Division Ms. Arretta Griffi th, Procurement Support Assistant (OA) Ms. Shelly Jenkins, Customer Account...Business Systems Modernization............715 DLA - Casting and Forging.................................712 DLA - Defense Distribution Center (DDC...219 Kovatch Castings , Inc.....................................409 Lambda Supply Corp......................................103 Lockheed

Finite-temperature dynamics of the Mott insulating Hubbard chain

Science.gov (United States)

Nocera, Alberto; Essler, Fabian H. L.; Feiguin, Adrian E.

2018-01-01

We study the dynamical response of the half-filled one-dimensional Hubbard model for a range of interaction strengths U and temperatures T by a combination of numerical and analytical techniques. Using time-dependent density matrix renormalization group computations we find that the single-particle spectral function undergoes a crossover to a spin-incoherent Luttinger liquid regime at temperatures T ˜J =4 t2/U for sufficiently large U >4 t . At smaller values of U and elevated temperatures the spectral function is found to exhibit two thermally broadened bands of excitations, reminiscent of what is found in the Hubbard-I approximation. The dynamical density-density response function is shown to exhibit a finite-temperature resonance at low frequencies inside the Mott gap, with a physical origin similar to the Villain mode in gapped quantum spin chains. We complement our numerical computations by developing an analytic strong-coupling approach to the low-temperature dynamics in the spin-incoherent regime.

Response properties of single units in the dorsal nucleus of the lateral lemniscus of decerebrate cats.

Science.gov (United States)

Davis, Kevin A; Lomakin, Oleg; Pesavento, Michael J

2007-09-01

The dorsal nucleus of the lateral lemniscus (DNLL) receives afferent inputs from many brain stem nuclei and, in turn, is a major source of inhibitory inputs to the inferior colliculus (IC). The goal of this study was to characterize the monaural and binaural response properties of neurons in the DNLL of unanesthetized decerebrate cat. Monaural responses were classified according to the patterns of excitation and inhibition observed in contralateral and ipsilateral frequency response maps. Binaural classification was based on unit sensitivity to interaural level differences. The results show that units in the DNLL can be grouped into three distinct types. Type v units produce contralateral response maps that show a wide V-shaped excitatory area and no inhibition. These units receive ipsilateral excitation and exhibit binaural facilitation. The contralateral maps of type i units show a more restricted I-shaped region of excitation that is flanked by inhibition. Type o maps display an O-shaped island of excitation at low stimulus levels that is bounded by inhibition at higher levels. Both type i and type o units receive ipsilateral inhibition and exhibit binaural inhibition. Units that produce type v maps have a low best frequency (BF), whereas type i and type o units have high BFs. Type v and type i units give monotonic rate-level responses for both BF tones and broadband noise. Type o units are inhibited by tones at high levels, but are excited by high-level noise. These results show that the DNLL can exert strong, differential effects in the IC.

Crystallization and preliminary crystallographic studies of the single-chain variable fragment of antibody chA21 in complex with an N-terminal fragment of ErbB2

International Nuclear Information System (INIS)

Liu, Yang; Zhou, Huihao; Zhu, Juanjuan; Gao, Yongxiang; Niu, Liwen; Liu, Jing; Teng, Maikun

2009-01-01

An antibody–antigen complex consisting of a single-chain variable fragment of the potential therapeutic antibody chA21 and an N-terminal fragment (residues 1–192) of the human ErbB2 extracellular domain was expressed, purified and crystallized. X-ray diffraction data were collected to 2.45 Å resolution. ErbB2 is a transmembrane tyrosine kinase, the overexpression of which causes abnormality and disorder in cell signalling and leads to cell transformation. Previously, an anti-ErbB2 single-chain chimeric antibody chA21 that specifically inhibits the growth of ErbB2-overexpressing cancer cells in vitro and in vivo was developed. Here, an antibody–antigen complex consisting of the single-chain variable fragment (scFv) of chA21 and an N-terminal fragment (residues 1–192, named EP I) of the ErbB2 extracellular domain was crystallized using the sitting-drop vapour-diffusion method. An X-ray diffraction data set was collected to 2.45 Å resolution from a single flash-cooled crystal; the crystal belonged to space group P2 1 2 1 2 1

Quantum double-well chain: Ground-state phases and applications to hydrogen-bonded materials

International Nuclear Information System (INIS)

Wang, X.; Campbell, D.K.; Gubernatis, J.E.

1994-01-01

Extrapolating the results of hybrid quantum Monte Carlo simulations to the zero temperature and infinite-chain-length limits, we calculate the ground-state phase diagram of a system of quantum particles on a chain of harmonically coupled, symmetric, quartic double-well potentials. We show that the ground state of this quantum chain depends on two parameters, formed from the ratios of the three natural energy scales in the problem. As a function of these two parameters, the quantum ground state can exhibit either broken symmetry, in which the expectation values of the particle's coordinate are all nonzero (as would be the case for a classical chain), or restored symmetry, in which the expectation values of the particle's coordinate are all zero (as would be the case for a single quantum particle). In addition to the phase diagram as a function of these two parameters, we calculate the ground-state energy, an order parameter related to the average position of the particle, and the susceptibility associated with this order parameter. Further, we present an approximate analytic estimate of the phase diagram and discuss possible physical applications of our results, emphasizing the behavior of hydrogen halides under pressure

Cell surface expression of single chain antibodies with applications to imaging of gene expression in vivo

International Nuclear Information System (INIS)

Northrop, Jeffrey P.; Bednarski, Mark; Li, King C.; Barbieri, Susan O.; Lu, Amy T.; Nguyen, Dee; Varadarajan, John; Osen, Maureen; Star-Lack, Josh

2003-01-01

Imaging of gene expression in vivo has many potential uses for biomedical research and drug discovery, ranging from the study of gene regulation and cancer to the non-invasive assessment of gene therapies. To streamline the development of imaging marker gene technologies for nuclear medicine, we propose a new approach to the design of reporter/probe pairs wherein the reporter is a cell surface-expressed single chain antibody variable fragment that has been raised against a low molecular weight imaging probe with optimized pharmacokinetic properties. Proof of concept of the approach was achieved using a single chain antibody variable fragment that binds with high affinity to fluorescein and an imaging probe consisting of fluorescein isothiocyanate coupled to the chelator diethylene triamine penta-acetic acid labeled with the gamma-emitter 111 In. We demonstrate specific high-affinity binding of this probe to the cell surface-expressed reporter in vitro and assess the in vivo biodistribution of the probe both in wild-type mice and in mice harboring tumor xenografts expressing the reporter. Specific uptake of the probe by, and in vivo imaging of, tumors expressing the reporter are shown. Since ScFvs with high affinities can be raised to almost any protein or small molecule, the proposed methodology may offer a new flexibility in the design of imaging tracer/reporter pairs wherein both probe pharmacokinetics and binding affinities can be readily optimized. (orig.)

Molecular dynamics simulation of radiation grafted FEP films as proton exchange membranes: Effects of the side chain length

DEFF Research Database (Denmark)

Li, Xue; Zhao, Yang; Li, Weiwei

2017-01-01

In order to study the microstructure of the prepared potential proton exchange membrane (PEM), molecular dynamics (MD) simulations were used to lucubrate the transport behavior of water molecules and hydronium ions inside the hydrated sulfonated styrene grafted fluorinated ethylene propylene (FEP...... whereas larger water clusters formed. The results of the mean square displacements (MSDs) show that the proton conductivities of the membranes with the proposed side chain lengths were about three fifths of the experimental data, of which the membrane with side chain length of 7 sulfonic styrene units...... was supposed to exhibit the highest proton conductivity, that is 115.69 mS cm-1. All of the supposed membrane models presented good proton conductivity that could definitely meet the application requirements of the proton exchange membranes. The MD simulations can provide an insight to the chain structure...

Ultrasensitive electrochemical detection of microRNA-21 combining layered nanostructure of oxidized single-walled carbon nanotubes and nanodiamonds by hybridization chain reaction.

Science.gov (United States)

Liu, Lingzhi; Song, Chao; Zhang, Zhang; Yang, Juan; Zhou, Lili; Zhang, Xing; Xie, Guoming

2015-08-15

Measurement of microRNA (miRNA) levels in body fluids is a crucial tool for the early diagnosis and prognosis of cancers. In this study, we developed an electrochemical assay to detect miRNA-21 by fabricating the electrode with layer-by-layer assembly of oxidized single-walled carbon nanotubes and nanodiamonds. Tetrahedron-structured probes with free-standing probe on the top served as receptors to hybridize with target miRNA directly. The probes were immobilized on the deposited gold nanoparticles through a well-established strong Au-S bond. The electrochemical signal was mainly derived from an ultrasensitive pattern by combining hybridization chain reaction with DNA-functionalized AuNPs, which provided DNAzyme to catalyze H2O2 reduction. Differential pulse voltammetry was applied to record the electrochemical signals, which was increased linearly with the target miRNA-21, and the linear detection range was 10 fM to 1.0 nM. The limit of detection reached 1.95 fM (S/N=3), and the proposed biosensor exhibited good reproducibility and stability, as well as high sensitivity. Hence, this biosensor has a promising potential in clinical application. Copyright © 2015 Elsevier B.V. All rights reserved.

[Technical aspects of treatments with single- and multi-unit fixed dental prostheses

NARCIS (Netherlands)

Wiersema, E.J.; Kreulen, C.M.; Latzke, P.; Witter, D.J.; Creugers, N.H.J.

2014-01-01

For the manufacture of single- and multi-unit fixed dental prostheses, effective communication between dentist and dental technician is required. Mutual insight concerning the (im)possibilities of available treatments and technical options is prerequisitefor this communication. The manufacture of

78 FR 7849 - Culturally Significant Objects Imported for Exhibition

Science.gov (United States)

2013-02-04

... Century,'' imported from abroad for temporary exhibition within the United States, are of cultural... also determine that the exhibition or display of the exhibit objects at The Yale Center for British Art..., Bureau of Educational and Cultural Affairs, Department of State. [FR Doc. 2013-02401 Filed 2-1-13; 8:45...

Two luminescent frameworks constructed from lead(II) salts with carboxylate ligands containing dinuclear lead(II) units

International Nuclear Information System (INIS)

Zhu Xiandong; Li Xiaoju; Liu Qingyan; Lue Jian; Guo Zhengang; He Jinrun; Li Yafeng; Cao Rong

2007-01-01

Two luminescent Pb(II) coordination frameworks containing dinuclear lead(II) units, [Pb(PYDC)(H 2 O)] n (1) and [Pb(HPHT)] n (2) have been prepared by the self-assembly of lead(II) salts with pyridinecarboxylate and benzenecarboxylate. Single-crystal X-ray diffraction analyses reveal that compound 1 is a three-dimensional architecture consisting of Pb 2 O 2 dimeric building units, whereas compound 2 is a two-dimensional layer structure containing one-dimensional lead-oxide chains. The luminescent properties of 1 and 2 have been investigated in the solid state at room temperature, indicating structure-dependent photoluminescent properties of the coordination frameworks. - Graphical abstract: Two luminescent Pb(II) coordination frameworks, [Pb(PYDC)(H 2 O)] n (1) and [Pb(HPHT)] n (2) have been prepared. Single-crystal analyses reveal that compound 1 is a three-dimensional architecture consisting of Pb 2 O 2 dimeric building units, whereas compound 2 is a two-dimensional layer structure containing one-dimensional lead-oxide chains. The luminescent properties have been investigated, indicating structure-dependent photoluminescent properties of the coordination frameworks

Identification and characterization of human polyserase-3, a novel protein with tandem serine-protease domains in the same polypeptide chain

Directory of Open Access Journals (Sweden)

Garabaya Cecilia

2006-03-01

-urokinase-type plasminogen activator (pro-uPA. Northern blot analysis showed that polyserase-3 exhibits a unique expression pattern among human polyserases, being predominantly detected in testis, liver, heart and ovary, as well as in several tumor cell lines. Conclusion These findings contribute to define the growing group of human polyserine proteases composed at present by three different proteins. All of them share a complex structural design with several catalytic units in a single polypeptide but also show specific features in terms of enzymatic properties, expression patterns and post-translational maturation mechanisms.

Analysis of the relationship between end-to-end distance and activity of single-chain antibody against colorectal carcinoma.

Science.gov (United States)

Zhang, Jianhua; Liu, Shanhong; Shang, Zhigang; Shi, Li; Yun, Jun

2012-08-22

We investigated the relationship of End-to-end distance between VH and VL with different peptide linkers and the activity of single-chain antibodies by computer-aided simulation. First, we developed (G4S)n (where n = 1-9) as the linker to connect VH and VL, and estimated the 3D structure of single-chain Fv antibody (scFv) by homologous modeling. After molecular models were evaluated and optimized, the coordinate system of every protein was built and unified into one coordinate system, and End-to-end distances calculated using 3D space coordinates. After expression and purification of scFv-n with (G4S)n as n = 1, 3, 5, 7 or 9, the immunoreactivity of purified ND-1 scFv-n was determined by ELISA. A multi-factorial relationship model was employed to analyze the structural factors affecting scFv: rn=ABn-ABO2+CDn-CDO2+BCn-BCst2. The relationship between immunoreactivity and r-values revealed that fusion protein structure approached the desired state when the r-value = 3. The immunoreactivity declined as the r-value increased, but when the r-value exceeded a certain threshold, it stabilized. We used a linear relationship to analyze structural factors affecting scFv immunoreactivity.

Consistency of the single calculus chain for climatological studies using long-term measurements from thessaloniki lidar station

Science.gov (United States)

Siomos, Nikolaos; Voudouri, Kalliopi A.; Filioglou, Maria; Giannakaki, Eleni; Amiridis, Vasilis; D'Amico, Giuseppe; Balis, Dimitris S.

2018-04-01

The long term analysis of 15 years of lidar data derived from a Raman lidar at Thessaloniki is presented here. All measurements have been processed with the latest version 4 of the EARLINET Single Calculus Chain algorithm and are compared with the results from the current operational retrieval algorithm. In this paper we investigate the consistency between the EARLINET database and SCC for the case of Thessaloniki and we identify the issues to be considered when switching from current operations to SCC.

Formation and properties of metal-oxygen atomic chains

DEFF Research Database (Denmark)

Thijssen, W.H.A.; Strange, Mikkel; de Brugh, J.M.J.A.

2008-01-01

of longer atomic chains. The mechanical and electrical properties of these diatomic chains have been investigated by determining local vibration modes of the chain and by measuring the dependence of the average chain-conductance on the length of the chain. Additionally, we have performed calculations......Suspended chains consisting of single noble metal and oxygen atoms have been formed. We provide evidence that oxygen can react with and be incorporated into metallic one-dimensional atomic chains. Oxygen incorporation reinforces the linear bonds in the chain, which facilitates the creation...

76 FR 68808 - Culturally Significant Objects Imported for Exhibition

Science.gov (United States)

2011-11-07

... also determine that the exhibition or display of the exhibit objects at the Onassis Cultural Center... Century AD,'' imported from abroad for temporary exhibition within the United States, are of cultural... Cultural Affairs, Department of State. [FR Doc. 2011-28805 Filed 11-4-11; 8:45 am] BILLING CODE 4710-05-P ...

Learning from Exhibitions: Chuck Close.

Science.gov (United States)

Johnson, Mark M.

1998-01-01

Discusses the artwork of Chuck Close, who is well known for his over-sized portraits of fellow artists and anonymous sitters, and the exhibition of his work that premiered at New York's Museum of Modern Art before traveling to other cities in the United States. (CMK)

Peramivir analogues bearing hydrophilic side chains exhibit higher activities against H275Y mutant than wild-type influenza virus.

Science.gov (United States)

Chiu, Din-Chi; Lin, Tzu-Chen; Huang, Wen-I; Cheng, Ting-Jen; Tsai, Keng-Chang; Fang, Jim-Min

2017-11-29

Peramivir is an effective anti-influenza drug in the clinical treatment of influenza, but its efficacy toward the H275Y mutant is reduced. The previously reported cocrystal structures of inhibitors in the mutant neuraminidase (NA) suggest that the hydrophobic side chain should be at the origin of reduced binding affinity. In contrast, zanamivir having a hydrophilic glycerol side chain still possesses high affinity toward the H275Y NA. We thus designed five peramivir analogues (5-9) carrying hydrophilic glycol or glycerol side chains, and evaluated their roles in anti-influenza activity, especially for the H275Y mutant. The synthetic sequence involves a key step of (3 + 2) cycloaddition reactions between alkenes and nitrile oxides to construct the scaffold of peramivir carrying the desired hydrophilic side chains and other appropriate functional groups. The molecular docking experiments reveal that the hydrophilic side chain can provide extra hydrogen bonding with the translocated Glu-276 residue in the H275Y NA active site. Thus, the H275Y mutant may be even more sensitive than wild-type virus toward the peramivir analogues bearing hydrophilic side chains. Notably, the peramivir analogue bearing a glycerol side chain inhibits the H275Y mutant with an IC 50 value of 35 nM, which is better than the WSN virus by 9 fold.

Understanding nanocellulose chirality and structure–properties relationship at the single fibril level

Science.gov (United States)

Usov, Ivan; Nyström, Gustav; Adamcik, Jozef; Handschin, Stephan; Schütz, Christina; Fall, Andreas; Bergström, Lennart; Mezzenga, Raffaele

2015-01-01

Nanocellulose fibrils are ubiquitous in nature and nanotechnologies but their mesoscopic structural assembly is not yet fully understood. Here we study the structural features of rod-like cellulose nanoparticles on a single particle level, by applying statistical polymer physics concepts on electron and atomic force microscopy images, and we assess their physical properties via quantitative nanomechanical mapping. We show evidence of right-handed chirality, observed on both bundles and on single fibrils. Statistical analysis of contours from microscopy images shows a non-Gaussian kink angle distribution. This is inconsistent with a structure consisting of alternating amorphous and crystalline domains along the contour and supports process-induced kink formation. The intrinsic mechanical properties of nanocellulose are extracted from nanoindentation and persistence length method for transversal and longitudinal directions, respectively. The structural analysis is pushed to the level of single cellulose polymer chains, and their smallest associated unit with a proposed 2 × 2 chain-packing arrangement. PMID:26108282

Understanding nanocellulose chirality and structure-properties relationship at the single fibril level

Science.gov (United States)

Usov, Ivan; Nyström, Gustav; Adamcik, Jozef; Handschin, Stephan; Schütz, Christina; Fall, Andreas; Bergström, Lennart; Mezzenga, Raffaele

2015-06-01

Nanocellulose fibrils are ubiquitous in nature and nanotechnologies but their mesoscopic structural assembly is not yet fully understood. Here we study the structural features of rod-like cellulose nanoparticles on a single particle level, by applying statistical polymer physics concepts on electron and atomic force microscopy images, and we assess their physical properties via quantitative nanomechanical mapping. We show evidence of right-handed chirality, observed on both bundles and on single fibrils. Statistical analysis of contours from microscopy images shows a non-Gaussian kink angle distribution. This is inconsistent with a structure consisting of alternating amorphous and crystalline domains along the contour and supports process-induced kink formation. The intrinsic mechanical properties of nanocellulose are extracted from nanoindentation and persistence length method for transversal and longitudinal directions, respectively. The structural analysis is pushed to the level of single cellulose polymer chains, and their smallest associated unit with a proposed 2 × 2 chain-packing arrangement.

A family of rare-earth-based single chain magnets: playing with anisotropy.

Science.gov (United States)

Bernot, Kevin; Bogani, Lapo; Caneschi, Andrea; Gatteschi, Dante; Sessoli, Roberta

2006-06-21

The first family of rare-earth-based single chain magnets is presented. Compounds of general formula [M(hfac)3(NITPhOPh)], where M = Eu, Gd, Tb, Dy, Ho, Er, or Yb, and PhOPh is the nitronyl-nitroxide radical (2,4'-benzoxo-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide), have been structurally characterized and found to be isostructural. The characterization of both static and dynamic magnetic properties of the whole family is reported. Dy, Tb, and Ho compounds display slow relaxation of the magnetization, and ac susceptibility shows a thermally activated regime with energy barriers of 69, 45, and 34 K for Dy, Tb, and Ho compounds, respectively, while only a frequency-dependent susceptibility is observed for Er below 2.0 K. In Gd and Yb derivatives, antiferromagnetic interactions dominate. The pre-exponential factors differ by about 4 orders of magnitude. Finite size effects, due to naturally occurring defects, affect the static and dynamic properties of the compounds differently.

Thermal contact through a two-temperature kinetic Ising chain

Science.gov (United States)

Bauer, M.; Cornu, F.

2018-05-01

We consider a model for thermal contact through a diathermal interface between two macroscopic bodies at different temperatures: an Ising spin chain with nearest neighbor interactions is endowed with a Glauber dynamics with different temperatures and kinetic parameters on alternating sites. The inhomogeneity of the kinetic parameter is a novelty with respect to the model of Racz and Zia (1994 Phys. Rev. E 49 139), and we exhibit its influence upon the stationary non equilibrium values of the two-spin correlations at any distance. By mapping to the dynamics of spin domain walls and using free fermion techniques, we determine the scaled generating function for the cumulants of the exchanged heat amounts per unit of time in the long time limit.

Ferromagnetic pairing states on two-coupled chains

International Nuclear Information System (INIS)

Tanaka, Akinori

2008-01-01

We propose a concrete model which exhibits ferromagnetism and electron-pair condensation simultaneously. The model is defined on two chains and consists of the electron hopping term, the on-site Coulomb repulsion and a ferromagnetic interaction which describes ferromagnetic coupling between two electrons, one on a bond in a chain and the other on a site in the other chain. It is rigorously shown that the model has fully-polarized ferromagnetic pairing ground states. The higher dimensional version of the model is also presented

Sibling rivalry vs. cousin solidarity : How ownership influences performance in franchise chains

NARCIS (Netherlands)

Mulotte, Louis; Parmigiani, A.

This study applies agglomeration theory to multiunit chains that co- locate corporate and franchised units. We analyze how the performance of a corporate unit is influenced by co-located same-chain units, distinguishing the effects by ownership structure. We argue that corporate ownership and

Synthesis and Characterization of Network Single Ion Conductors(NSIC) Based On Comb-Branched Polyepoxide Ethers and Lithium Bis(allylmalonato)borate

International Nuclear Information System (INIS)

Sun, Xiao-Guang; Kerr, John B.

2004-01-01

Network single ion conductors (NSICs) based on comb-branch polyepoxide ethers and lithium bis(allylmalonato) borate have been synthesized and thoroughly characterized by means of ionic conductivity measurements, electrochemical impedance and by dynamic mechanical analysis (DMA). The materials have been tested as battery electrolytes by cycling in symmetrical Li/Li half cells and in Li/V 6 O 13 full cells in which the NSIC was used as both binder and electrolyte in the cathode electrode and as the electrolyte separator membrane,. The substitution of the trimethylene oxide (TMO) unit into the side chains in place of ethylene oxide (EO) units increased the polymerion mobility (lower glass transition temperature). However, the ionic conductivity was nearly one and half orders of magnitude lower than the corresponding pure EO based single ion conductor at the same salt concentration. This effect may be ascribed to the lower dielectric constant of the TMO side chains that result in a lower concentration of free conducting lithium cations. For a highly cross-linked system (EO/Li=20), only 47 wt% plasticizing solvent (ethylene carbonate (EC)/ethyl methyl carbonate (EMC), 1/1 by wt) could be taken up and the ionic conductivity was only increased by one order of magnitude over the dry polyelectrolyte while for a less densely crosslinked system (EO/Li=80), up to 75 wt% plasticizer could be taken up and the ionic conductivity was increased by nearly two orders of magnitude. A Li/Li symmetric cell that was cycled at 85 C at a current density of 25(micro)Acm -2 showed no concentration polarization or diffusional relaxation, consistent with a lithium ion transference number of one. However, both the bulk and interfacial impedances increased after 20 cycles, apparently due to continued cross-linking reactions within the membrane and on the surface of the lithium electrodes. A Li/V 6 O 13 full cell constructed using a single ion conductor gel (propylene carbonate (PC)/EMC, 1/1 in

Comparison of reverse transcription-quantitative polymerase chain reaction methods and platforms for single cell gene expression analysis.

Science.gov (United States)

Fox, Bridget C; Devonshire, Alison S; Baradez, Marc-Olivier; Marshall, Damian; Foy, Carole A

2012-08-15

Single cell gene expression analysis can provide insights into development and disease progression by profiling individual cellular responses as opposed to reporting the global average of a population. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) is the "gold standard" for the quantification of gene expression levels; however, the technical performance of kits and platforms aimed at single cell analysis has not been fully defined in terms of sensitivity and assay comparability. We compared three kits using purification columns (PicoPure) or direct lysis (CellsDirect and Cells-to-CT) combined with a one- or two-step RT-qPCR approach using dilutions of cells and RNA standards to the single cell level. Single cell-level messenger RNA (mRNA) analysis was possible using all three methods, although the precision, linearity, and effect of lysis buffer and cell background differed depending on the approach used. The impact of using a microfluidic qPCR platform versus a standard instrument was investigated for potential variability introduced by preamplification of template or scaling down of the qPCR to nanoliter volumes using laser-dissected single cell samples. The two approaches were found to be comparable. These studies show that accurate gene expression analysis is achievable at the single cell level and highlight the importance of well-validated experimental procedures for low-level mRNA analysis. Copyright © 2012 Elsevier Inc. All rights reserved.

An unusual mono-substituted Keggin anion-chain based 3D framework with 24-membered macrocycles as linker units

International Nuclear Information System (INIS)

Pang Haijun; Ma Huiyuan; Yu Yan; Yang Ming; Xun Ye; Liu Bo

2012-01-01

A new compound, [Cu I (H 2 O)(Hbpp) 2 ]⊂{[Cu I (bpp)] 2 [PW 11 Cu II O 39 ]} (1) (bpp=1,3-bis(4-pyridyl)propane), has been hydrothermally synthesized and structurally characterized by single crystal X-ray diffraction. In compound 1, the unusual –A–B–A–B– array mono-substituted Keggin anion-chains and 24-membered (Cubpp) 2 cation-macrocycles are linked together to form a (2, 4) connected 3D framework with channels of ca. 9.784×7.771 Å 2 along two directions, in which the [Cu(H 2 O)(Hbpp) 2 ] coordination fragments as guest components are trapped. The photocatalytic experiments of compound 1 were performed, which show a good catalytic activity of compound 1 for photodegradation of RhB. Furthermore, the IR, TGA and electrochemical properties of compound 1 were investigated. - Graphical abstract: An unusual example of mono-substituted Keggin anion-chain based hybrid compound that possesses a 3D structure has been synthesized, which offers a feasible route for synthesis of such compounds. Highlights: ► The first example of –A–B–A–B– array mono-substituted Keggin chain is observed. ► An unusual three dimensional structure based mono-substituted Keggin anion-chains. ► The photocatalysis and electrochemical properties of the title compound were studied.

Supply Chain Management in Albania: An Empirical Study

OpenAIRE

Alma Spaho, Thoma Mitre

2012-01-01

Supply chain management in Albania has received little attention in the recent literature. Many companies now realize that actions taken by one member of the chain can influence the profitability of all others in the chain. Companies are increasingly thinking in terms of competing as part of a supply chain against other supply chains, rather than as a single firm against other individual firms. The aim of the paper is to investigate the current situation of supply chain management in Albania ...

Fast response dry-type artificial molecular muscles with [c2]daisy chains

Science.gov (United States)

Iwaso, Kazuhisa; Takashima, Yoshinori; Harada, Akira

2016-06-01

Hierarchically organized myosin and actin filaments found in biological systems exhibit contraction and expansion behaviours that produce work and force by consuming chemical energy. Inspired by these naturally occurring examples, we have developed photoresponsive wet- and dry-type molecular actuators built from rotaxane-based compounds known as [c2]daisy chains (specifically, [c2]AzoCD2 hydrogel and [c2]AzoCD2 xerogel). These actuators were prepared via polycondensation between four-armed poly(ethylene glycol) and a [c2]daisy chain based on α-cyclodextrin as the host component and azobenzene as a photoresponsive guest component. The light-induced actuation arises from the sliding motion of the [c2]daisy chain unit. Ultraviolet irradiation caused the gels to bend towards the light source. The response of the [c2]AzoCD2 xerogel, even under dry conditions, is very fast (7° every second), which is 10,800 times faster than the [c2]AzoCD2 hydrogel (7° every 3 h). In addition, the [c2]AzoCD2 xerogel was used as a crane arm to lift an object using ultraviolet irradiation to produce mechanical work.

Molecular Dynamics Simulations of Silica Nanoparticles Grafted with Poly(ethylene oxide) Oligomer Chains

KAUST Repository

Hong, Bingbing

2012-03-01

A molecular model of silica nanoparticles grafted with poly(ethylene oxide) oligomers has been developed for predicting the transport properties of nanoparticle organic-hybrid materials (NOHMs). Ungrafted silica nanoparticles in a medium of poly(ethylene oxide) oligomers were also simulated to clarify the effect of grafting on the dynamics of nanoparticles and chains. The model approximates nanoparticles as solid spheres and uses a united-atom representation for chains, including torsional and bond-bending interactions. The calculated viscosities from Green-Kubo relationships and temperature extrapolation are of the same order of magnitude as experimental data but show a smaller activation energy relative to real NOHMs systems. Grafted systems have higher viscosities, smaller diffusion coefficients, and slower chain dynamics than the ungrafted ones at high temperatures. At lower temperatures, grafted systems exhibit faster dynamics for both nanoparticles and chains relative to ungrafted systems, because of lower aggregation of particles and enhanced correlations between nanoparticles and chains. This agrees with the experimental observation that NOHMs have liquidlike behavior in the absence of a solvent. For both grafted and ungrafted systems at low temperatures, increasing chain length reduces the volume fraction of nanoparticles and accelerates the dynamics. However, at high temperatures, longer chains slow down nanoparticle diffusion. From the Stokes-Einstein relationship, it was determined that the coarse-grained treatment of nanoparticles leads to slip on the nanoparticle surfaces. Grafted systems obey the Stokes-Einstein relationship over the temperature range simulated, but ungrafted systems display deviations from it. © 2012 American Chemical Society.

Quantum gates controlled by spin chain soliton excitations

Energy Technology Data Exchange (ETDEWEB)

Cuccoli, Alessandro, E-mail: cuccoli@fi.infn.it [Dipartimento di Fisica e Astronomia, Università di Firenze, I-50019 Sesto Fiorentino (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Firenze, I-50019 Sesto Fiorentino (Italy); Nuzzi, Davide [Dipartimento di Fisica e Astronomia, Università di Firenze, I-50019 Sesto Fiorentino (Italy); Vaia, Ruggero [Istituto dei Sistemi Complessi, Consiglio Nazionale delle Ricerche, I-50019 Sesto Fiorentino (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Firenze, I-50019 Sesto Fiorentino (Italy); Verrucchi, Paola [Istituto dei Sistemi Complessi, Consiglio Nazionale delle Ricerche, I-50019 Sesto Fiorentino (Italy); Dipartimento di Fisica e Astronomia, Università di Firenze, I-50019 Sesto Fiorentino (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Firenze, I-50019 Sesto Fiorentino (Italy)

2014-05-07

Propagation of soliton-like excitations along spin chains has been proposed as a possible way for transmitting both classical and quantum information between two distant parties with negligible dispersion and dissipation. In this work, a somewhat different use of solitons is considered. Solitons propagating along a spin chain realize an effective magnetic field, well localized in space and time, which can be exploited as a means to manipulate the state of an external spin (i.e., a qubit) that is weakly coupled to the chain. We have investigated different couplings between the qubit and the chain, as well as different soliton shapes, according to a Heisenberg chain model. It is found that symmetry properties strongly affect the effectiveness of the proposed scheme, and the most suitable setups for implementing single qubit quantum gates are singled out.

Magneto-structural correlations in a family of Fe(II)Re(IV)(CN)2 single-chain magnets: density functional theory and ab initio calculations.

Science.gov (United States)

Zhang, Yi-Quan; Luo, Cheng-Lin; Wu, Xin-Bao; Wang, Bing-Wu; Gao, Song

2014-04-07

Until now, the expressions of the anisotropic energy barriers Δξ and ΔA, using the uniaxial magnetic anisotropy D, the intrachain coupling strength J, and the high-spin ground state S for single-chain magnets (SCMs) in the intermediate region between the Ising and the Heisenberg limits, were unknown. To explore this relationship, we used density functional theory and ab initio methods to obtain expressions of Δξ and ΔA in terms of D, J, and S of six R4Fe(II)-Re(IV)Cl4(CN)2 (R = diethylformamide (1), dibutylformamide (2), dimethylformamide (3), dimethylbutyramide (4), dimethylpropionamide (5), and diethylacetamide (6)) SCMs in the intermediate region. The ΔA value for compounds 1-3 was very similar to the magnetic anisotropic energy of a single Fe(II), while the value of Δξ was predicted using the exchange interaction of Fe(II) with the neighboring Re(IV), which could be expressed as 2JSReSFe. Similar to compounds 1-3, the anisotropy energy barrier ΔA of compounds 4 and 5 was also equal to (Di - Ei)SFe(2), but the correlation energy Δξ was closely equal to 2JSReSFe(cos 98.4 - cos 180) due to the reversal of the spins on the opposite Fe(II). For compound 6, one unit cell of Re(IV)Fe(II) was regarded as a domain wall since it had two different Re(IV)-Fe(II) couplings. Thus, the Δξ of compound 6 was expressed as 4J″SRe1Fe1SRe2Fe2, where J″ was the coupling constant of the neighboring unit cells of Re1Fe1 and Re2Fe2, and ΔA was equal to the anisotropic energy barrier of one domain wall given by DRe1Fe1(S(2)Re1Fe1 - 1/4).

Chain Dynamics in Magnetorheological Suspensions

Science.gov (United States)

Gast, A. P.; Furst, E. M.

1999-01-01

Magnetorheological (MR) suspensions are composed of colloidal particles which acquire dipole moments when subjected to an external magnetic field. At sufficient field strengths and concentrations, the dipolar particles rapidly aggregate to form long chains. Subsequent lateral cross-linking of the dipolar chains is responsible for a rapid liquid-to-solid-like rheological transition. The unique, magnetically-activated rheological properties of MR suspensions make them ideal for interfacing mechanical systems to electronic controls. Additionally, the ability to experimentally probe colloidal suspensions interacting through tunable anisotropic potentials is of fundamental interest. Our current experimental work has focused on understanding the fluctuations of dipolar chains. It has been proposed by Halsey and Toor (HT) that the strong Landau-Peierls thermal fluctuations of dipolar chains could be responsible for long-range attractions between chains. Such interactions will govern the long-time relaxation of MR suspensions. We have synthesized monodisperse neutrally buoyant MR suspensions by density matching stabilized ferrofluid emulsion droplets with D2O. This allows us to probe the dynamics of the dipolar chains using light scattering without gravitational, interfacial, and polydispersity effects to resolve the short-wavelength dynamics of the dipolar chains. We used diffusing wave spectroscopy to measure these dynamics. The particle displacements at short times that show an independence to the field strength, but at long times exhibit a constrained, sub-diffusive motion that slows as the dipole strength is increased. The experiments are in good qualitative agreement with Brownian dynamics simulations of dipolar chains. Although there have been several important and detailed studies of the structure and interactions in MR suspensions, there has not been conclusive evidence that supports or contradicts the HT model prediction that long-range interactions exist between

Solar-powered single-and double-effect directly air-cooled LiBr–H2O absorption prototype built as a single unit

International Nuclear Information System (INIS)

Izquierdo, M.; González-Gil, A.; Palacios, E.

2014-01-01

Highlights: • This work presents a novel solar cooling air-cooled absorption prototype for buildings. • The solution (LiB r –H 2 O) and the refrigerant (H 2 O) are cooled directly by air. • The cooling is produced from solar energy when operates in single-effect mode. • If the demand is not met the prototype is able to operate in double-effect mode. - Abstract: This work describes an installation in Madrid, Spain, designed to test a new solar-powered air-cooled absorption refrigeration system. This installation essentially consists of a-48 m 2 field of flat-plate solar collectors, a 1500-L hot water storage tank and a single and-double effect air-cooled lithium bromide absorption prototype. Designed and built by our research group, this prototype is able to operate either as a single-effect unit (4.5 kW) or as a double-effect unit (7 kW). In operation as single-effect mode, the prototype is driven by solar energy, whereas in operation as a double effect mode, an external energy source may be used. The prototype’s evaporator is connected to a fan-coil placed inside an 80-m 2 laboratory that represent the average size of a Spanish housing unit. In August 2009, the cooling system was tested in the single-effect operation mode. The results show that the system is able to meet approximately 65% of the laboratory’s seasonal cooling demand, although 100% may be reached for a few days. The prototype can also operate in double-effect mode to meet the cooling demand. In that case, the prototype is fed by thermal oil, which is warmed until it reaches the process temperature in the high-temperature generator. The prototype can operate in either single-effect mode or in double-effect mode or can also operate simultaneously both modes using the components common to both modes, namely, the absorber, evaporator, condenser, solution pumps and control equipment. This paper reports the experimental results from the prototype operating separately in single-effect and

Stimulated polarization wave process in spin 3/2 chains

International Nuclear Information System (INIS)

Furman, G. B.

2007-01-01

Stimulated wave of polarization, triggered by a flip of a single spin, presents a simple model of quantum amplification. Recently, it has been demonstrated that, in an idealized one-dimensional Ising spin 1/2 chain with nearest-neighbor interactions and realistic spin 1/2 chain including the natural dipole-dipole interactions, irradiated by a weak resonant transverse field, a wave of flipped spins can be triggered by a single spin flip. Here we focuse on control of polarization wave in chain of spin 3/2, where the nuclear quadrupole interaction is dominant. Results of simulations for 1D spin chains and rings with up to five spins are presented.

Direct observation of the discrete energy spectrum of two lanthanide-based single-chain magnets by far-infrared spectroscopy

Science.gov (United States)

Haas, Sabrina; Heintze, Eric; Zapf, Sina; Gorshunov, Boris; Dressel, Martin; Bogani, Lapo

2014-05-01

The far-infrared optical transmission has been studied for two lanthanide-based single-chain magnets DyPhOPh and TbPhOPh in the frequency range between 3 and 80 cm-1. The spectra were acquired at temperatures between 2 and 80 K and magnetic fields up to 6 T. Based on their magnetic field dependence in DyPhOPh two of the observed absorption lines are identified as transitions inside the crystal field split Dy3+ ground multiplet 6H15/2, coupled to the neighboring spins. In TbPhOPh one transition was observed inside the crystal-field-split Tb3+ ground multiplet 7F6. The results allow a spectroscopic investigation of the role of single-ion anisotropy and exchange in Glauber dynamics.

Narrow and broad solitons in the antiferromagnetic chains of CsCoCl3 and TMMC

International Nuclear Information System (INIS)

Boucher, J.P.; Regnault, L.P.; Pires, A.; Rossat-Mignod, J.; Henry, Y.; Bouillot, J.; Stirling, W.G.; Renard, J.P.

1984-06-01

The two quasi one-dimensional (1D) compounds CsCoCl 3 and (CH 3 ) 4 NMnCl 3 (TMMC) are almost ideal systems in which to study soliton excitations. Both they have antiferromagnetic (AF) couplings in the chains and at low temperature they exhibit an Ising symmetry favourable for the occurence of solitons. This symmetry is an intrinsic property of CsCoCl 3 while in TMMC it is only achieved by the application of an external magnetic field H perpendicular to the chains. In the lD short range order regime two energetically equivalent configurations are expected for the spins. Solitons can be seen as Bloch walls separating ordered domains and allowing the spins to pass from one configuration to the other. In the case of a ''strong'' Ising symmetry (CsCoCl 3 ) the walls are reduced to one lattice unit (''narrow'' solitons) while in the case of a ''weak'' Ising symmetry (TMMC) the walls extend over several lattice units (10 to 30) (''broad'' solitons). To maintain a paramagnetic state, these walls move rapidly along the chains inducing characteristic fluctuations. The investigation of these two compounds, CsCoCl 3 and TMMC illustrates the advantage of antiferromagnets as the AF mode yields an accurate determination of the soliton regime. Narrow and broad solitons are observed to behave very similarly

Electronic and transport properties of noncollinear magnetic monatomic Mn chains: Fano resonances in the superlattice of noncollinear magnetic barriers and magnetic anisotropic bands

International Nuclear Information System (INIS)

Dai, C.J.; Yan, X.H.; Xiao, Y.; Guo, Y.D.

2015-01-01

By means of the density functional theory combined with non-equilibrium Green's function method, ballistic transport properties of one-dimensional noncollinear magnetic monatomic chains were investigated using the single-atomic Mn chains as a model system. Fano resonances are found to exist in the monatomic Mn chains with spin-spiral structure. Furthermore, in the monatomic Mn chains with magnetic soliton lattice, Fano resonances are enhanced and cause the conductance splitting in the transmission spectra. The Fano resonances in the noncollinear magnetic single-atomic Mn chains are arising from the coupling of the localized d-states and the extended states of the quantum channels. By constructing a theoretical model and calculating its conductance, it is found that the phenomena of Fano resonances and the accompanying conductance splitting exist universally in the superlattice of one-dimensional noncollinear magnetic barriers, due to the interference of the incident waves and reflected waves by the interfaces between the neighboring barriers. Moreover, the band structures of the ferromagnetic and spin-spiral monatomic Mn chains exhibit a strong dependence on the spatial arrangement of the magnetic moments of Mn atoms when spin–orbit coupling is considered. - Highlights: • Transport properties of noncollinear magnetic monatomic Mn chains are studied. • Fano resonances are found in the noncollinear magnetic monatomic Mn chains. • Magnetic soliton lattice leads to conductance splitting in the transmission curve. • Fano resonances exist in the superlattice of noncollinear magnetic barriers. • Effect of SOC on the band structure of FM and spin-spiral Mn chains are studied

Monte Carlo calculations of the free-molecule drag on chains of uniform spheres

International Nuclear Information System (INIS)

Dahneke, B.; Chan, P.

1980-01-01

Monte Carlo calculations of the free-molecule drag on straight chains of uniform spheres are presented. The drag on a long chain is expressed in terms of the drag on a basic chain unit (two hemispheres touching at their poles) multiplied by the number of spheres in the chain. Since there is no interaction between the basic chain units, it is argued that the results also apply as a good approximation to the drag on kinked and branched chains covering a broad range of geometries. Experimental data are cited which support this claim

Agricultural production in the United States by county: a compilation of information from the 1974 census of agriculture for use in terrestrial food-chain transport and assessment models

Energy Technology Data Exchange (ETDEWEB)

Shor, R.W.; Baes, C.F. III; Sharp, R.D.

1982-01-01

Terrestrial food-chain models that simulate the transport of environmentally released radionuclides incorporate parameters describing agricultural production and practice. Often a single set of default parameters, such as that listed in USNRC Regulatory Guide 1.109, is used in lieu of site-specific information. However, the geographical diversity of agricultural practice in the United States suggests the limitations of a single set of default parameters for assessment models. This report documents default parameters with a county-wide resolution based on analysis of the 1974 US Census of Agriculture for use in terrestrial food chain models. Data reported by county, together with state-based information from the US Department of Agriculture, Economic and Statistics Service, provided the basis for estimates of model input parameters. This report also describes these data bases, their limitations, and lists default parameters by county. Vegetable production is described for four categories: leafy vegetables; vegetables and fruits exposed to airborne material; vegetables, fruits, and nuts protected from airborne materials; and grains. Livestock feeds were analyzed in categories of hay, silage, pasture, and grains. Pasture consumption was estimated from cattle and sheep inventories, their feed requirements, and reported quantities of harvested forage. The results were compared with assumed yields of the pasture areas reported. In addition, non-vegetable food production estimates including milk, beef, pork, lamb, poultry, eggs, goat milk, and honey are described. The agricultural parameters and land use information - in all 47 items - are tabulated in four appendices for each of the 3067 counties of the US reported to the Census of Agriculture, excluding those in Hawaii and Alaska.

Agricultural production in the United States by county: a compilation of information from the 1974 census of agriculture for use in terrestrial food-chain transport and assessment models

International Nuclear Information System (INIS)

Shor, R.W.; Baes, C.F. III; Sharp, R.D.

1982-01-01

Terrestrial food-chain models that simulate the transport of environmentally released radionuclides incorporate parameters describing agricultural production and practice. Often a single set of default parameters, such as that listed in USNRC Regulatory Guide 1.109, is used in lieu of site-specific information. However, the geographical diversity of agricultural practice in the United States suggests the limitations of a single set of default parameters for assessment models. This report documents default parameters with a county-wide resolution based on analysis of the 1974 US Census of Agriculture for use in terrestrial food chain models. Data reported by county, together with state-based information from the US Department of Agriculture, Economic and Statistics Service, provided the basis for estimates of model input parameters. This report also describes these data bases, their limitations, and lists default parameters by county. Vegetable production is described for four categories: leafy vegetables; vegetables and fruits exposed to airborne material; vegetables, fruits, and nuts protected from airborne materials; and grains. Livestock feeds were analyzed in categories of hay, silage, pasture, and grains. Pasture consumption was estimated from cattle and sheep inventories, their feed requirements, and reported quantities of harvested forage. The results were compared with assumed yields of the pasture areas reported. In addition, non-vegetable food production estimates including milk, beef, pork, lamb, poultry, eggs, goat milk, and honey are described. The agricultural parameters and land use information - in all 47 items - are tabulated in four appendices for each of the 3067 counties of the US reported to the Census of Agriculture, excluding those in Hawaii and Alaska

Exploration Supply Chain Simulation

Science.gov (United States)

2008-01-01

The Exploration Supply Chain Simulation project was chartered by the NASA Exploration Systems Mission Directorate to develop a software tool, with proper data, to quantitatively analyze supply chains for future program planning. This tool is a discrete-event simulation that uses the basic supply chain concepts of planning, sourcing, making, delivering, and returning. This supply chain perspective is combined with other discrete or continuous simulation factors. Discrete resource events (such as launch or delivery reviews) are represented as organizational functional units. Continuous resources (such as civil service or contractor program functions) are defined as enabling functional units. Concepts of fixed and variable costs are included in the model to allow the discrete events to interact with cost calculations. The definition file is intrinsic to the model, but a blank start can be initiated at any time. The current definition file is an Orion Ares I crew launch vehicle. Parameters stretch from Kennedy Space Center across and into other program entities (Michaud Assembly Facility, Aliant Techsystems, Stennis Space Center, Johnson Space Center, etc.) though these will only gain detail as the file continues to evolve. The Orion Ares I file definition in the tool continues to evolve, and analysis from this tool is expected in 2008. This is the first application of such business-driven modeling to a NASA/government-- aerospace contractor endeavor.

Determination of backbone chain direction of PDA using FFM

Science.gov (United States)

Jo, Sadaharu; Okamoto, Kentaro; Takenaga, Mitsuru

2010-01-01

The effect of backbone chains on friction force was investigated on both Langmuir-Blodgett (LB) films of 10,12-heptacosadiynoic acid and the (0 1 0) surfaces of single crystals of 2,4-hexadiene-1,6-diol using friction force microscopy (FFM). It was observed that friction force decreased when the scanning direction was parallel to the [0 0 1] direction in both samples. Moreover, friction force decreased when the scanning direction was parallel to the crystallographic [1 0 2], [1 0 1], [1 0 0] and [1 0 1¯] directions in only the single crystals. For the LB films, the [0 0 1] direction corresponds to the backbone chain direction of 10,12-heptacosadiynoic acid. For the single crystals, both the [0 0 1] and [1 0 1] directions correspond to the backbone chain direction, and the [1 0 2], [1 0 0] and [1 0 1¯] directions correspond to the low-index crystallographic direction. In both the LB films and single crystals, the friction force was minimized when the directions of scanning and the backbone chain were parallel.

Role of single-point mutations and deletions on transition temperatures in ideal proteinogenic heteropolymer chains in the gas phase.

Science.gov (United States)

Olivares-Quiroz, L

2016-07-01

A coarse-grained statistical mechanics-based model for ideal heteropolymer proteinogenic chains of non-interacting residues is presented in terms of the size K of the chain and the set of helical propensities [Formula: see text] associated with each residue j along the chain. For this model, we provide an algorithm to compute the degeneracy tensor [Formula: see text] associated with energy level [Formula: see text] where [Formula: see text] is the number of residues with a native contact in a given conformation. From these results, we calculate the equilibrium partition function [Formula: see text] and characteristic temperature [Formula: see text] at which a transition from a low to a high entropy states is observed. The formalism is applied to analyze the effect on characteristic temperatures [Formula: see text] of single-point mutations and deletions of specific amino acids [Formula: see text] along the chain. Two probe systems are considered. First, we address the case of a random heteropolymer of size K and given helical propensities [Formula: see text] on a conformational phase space. Second, we focus our attention to a particular set of neuropentapeptides, [Met-5] and [Leu-5] enkephalins whose thermodynamic stability is a key feature on their coupling to [Formula: see text] and [Formula: see text] receptors and the triggering of biochemical responses.

Air Quality and Health Impacts of an Aviation Biofuel Supply Chain Using Forest Residue in the Northwestern United States.

Science.gov (United States)

Ravi, Vikram; Gao, Allan H; Martinkus, Natalie B; Wolcott, Michael P; Lamb, Brian K

2018-04-03

Forest residue is a major potential feedstock for second-generation biofuel; however, little knowledge exists about the environmental impacts of the development and production of biofuel from such a feedstock. Using a high-resolution regional air quality model, we estimate the air quality impacts of a forest residue based aviation biofuel supply chain scenario in the Pacific Northwestern United States. Using two potential supply chain regions, we find that biomass and biofuel hauling activities will add simulation. Using BenMAP, a health impact assessment tool, we show that avoiding slash pile burning results in a decrease in premature mortality as well as several other nonfatal and minor health effects. In general, we show that most air quality and health benefits result primarily from avoided slash pile burning emissions.

An extended chain Ising model and its Glauber dynamics

International Nuclear Information System (INIS)

Zhao Xing-Yu; Fan Xiao-Hui; Huang Yi-Neng; Huang Xin-Ru

2012-01-01

It was first proposed that an extended chain Ising (ECI) model contains the Ising chain model, single spin double-well potentials and a pure phonon heat bath of a specific energy exchange with the spins. The extension method is easy to apply to high dimensional cases. Then the single spin-flip probability (rate) of the ECI model is deduced based on the Boltzmann principle and general statistical principles of independent events and the model is simplified to an extended chain Glauber—Ising (ECGI) model. Moreover, the relaxation dynamics of the ECGI model were simulated by the Monte Carlo method and a comparison with the predictions of the special chain Glauber—Ising (SCGI) model was presented. It was found that the results of the two models are consistent with each other when the Ising chain length is large enough and temperature is relative low, which is the most valuable case of the model applications. These show that the ECI model will provide a firm physical base for the widely used single spin-flip rate proposed by Glauber and a possible route to obtain the single spin-flip rate of other form and even the multi-spin-flip rate. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Cylindrical polymer brushes with dendritic side chains by iterative anionic reactions

KAUST Repository

Zhang, Hefeng

2015-05-01

We report in this paper an easy method for the synthesis of cylindrical polymer brushes with dendritic side chains through anionic reaction. The synthesis is accomplished by iteratively grafting a living block copolymer, polyisoprene-. b-polystyrenyllithium (PI-. b-PSLi), to the main chain and subsequently to the branches in a divergent way. PI segment is short and serves as a precursor for multifunctional branching unit. The grafting reaction involves two successive steps: i) epoxidation of internal double bonds of PI segments, either in main chain or side chains; ii) ring-opening addition to the resulting epoxy group by the living PI-. b-PSLi. Repeating the two steps affords a series of cylindrical polymer brushes with up to 3rd generation and extremely high molecular weight. The branching multiplicity depends on the average number of oxirane groups per PI segment, usually ca. 8 in the present work. The high branching multiplicity leads to tremendous increase in molecular weights of the cylindrical products with generation growth. Several series of cylindrical polymer brushes with tunable aspect ratios are prepared using backbones and branches with controlled lengths. Shape anisotropy is investigated in dilute solution using light scattering technique. Worm-like single molecular morphology with large persistence length is observed on different substrates by atomic force microscopy.

Reaction pathway towards formation of cobalt single chain magnets and nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Balaji, G.; Desilva, Rohini M.; Palshin, V. [Center for Advanced Microstructures and Devices, Louisiana State University, 6980 Jefferson Highway, Baton Rouge, LA 70806 (United States); Desilva, N. [Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803 (United States); Palmer, G. [Department of Biochemistry and Cell Biology, Rice University, MS 140, 6100 Main street, Houston, TX 77251 (United States); Kumar, Challa S.S.R., E-mail: ckumar1@lsu.ed [Center for Advanced Microstructures and Devices, Louisiana State University, 6980 Jefferson Highway, Baton Rouge, LA 70806 (United States)

2010-03-15

With the advent of molecular magnets the quest for suitable high density magnetic storage materials has fuelled further research in this area. Here in this report, we present a detailed mechanistic investigation of thermal decomposition of cyclopentadienyl cobalt [CoCp(CO){sub 2}] precursor where Cp is the cyclopentadienyl moiety. The reaction revealed the formation of cobalt nanoparticles (Co-NPs) through an isolable reaction intermediate characterized as a Single Chain Magnet (SCM), [Co(Cp){sub 2}]{sub 2}CoCl{sub 4} (1). The SQUID magnetic measurements showed the presence of very strong antiferromagnetic interactions between Co{sup 2+} ions. The zero-field cooled (ZFC) and field cooled (FC) magnetization curves branch out below 5 K and there is evidence for frequency dependent complex susceptibility along with a maximum observed around 2.5 K. The optical studies indicated that the Co{sup 2+} d-d transition is influenced by the polarity of the solvents. The cobalt nanoparticles (Co-NPs) were obtained, either directly from 1 or from its precursor. They are spherical in shape with a mean size 15 nm, have fcc crystal structure and were found to be ferromagnetic at room temperature.

Nodal-chain metals.

Science.gov (United States)

Bzdušek, Tomáš; Wu, QuanSheng; Rüegg, Andreas; Sigrist, Manfred; Soluyanov, Alexey A

2016-10-06

The band theory of solids is arguably the most successful theory of condensed-matter physics, providing a description of the electronic energy levels in various materials. Electronic wavefunctions obtained from the band theory enable a topological characterization of metals for which the electronic spectrum may host robust, topologically protected, fermionic quasiparticles. Many of these quasiparticles are analogues of the elementary particles of the Standard Model, but others do not have a counterpart in relativistic high-energy theories. A complete list of possible quasiparticles in solids is lacking, even in the non-interacting case. Here we describe the possible existence of a hitherto unrecognized type of fermionic excitation in metals. This excitation forms a nodal chain-a chain of connected loops in momentum space-along which conduction and valence bands touch. We prove that the nodal chain is topologically distinct from previously reported excitations. We discuss the symmetry requirements for the appearance of this excitation and predict that it is realized in an existing material, iridium tetrafluoride (IrF 4 ), as well as in other compounds of this class of materials. Using IrF 4 as an example, we provide a discussion of the topological surface states associated with the nodal chain. We argue that the presence of the nodal-chain fermions will result in anomalous magnetotransport properties, distinct from those of materials exhibiting previously known excitations.

A discrete particle swarm optimization algorithm with local search for a production-based two-echelon single-vendor multiple-buyer supply chain

Science.gov (United States)

Seifbarghy, Mehdi; Kalani, Masoud Mirzaei; Hemmati, Mojtaba

2016-03-01

This paper formulates a two-echelon single-producer multi-buyer supply chain model, while a single product is produced and transported to the buyers by the producer. The producer and the buyers apply vendor-managed inventory mode of operation. It is assumed that the producer applies economic production quantity policy, which implies a constant production rate at the producer. The operational parameters of each buyer are sales quantity, sales price and production rate. Channel profit of the supply chain and contract price between the producer and each buyer is determined based on the values of the operational parameters. Since the model belongs to nonlinear integer programs, we use a discrete particle swarm optimization algorithm (DPSO) to solve the addressed problem; however, the performance of the DPSO is compared utilizing two well-known heuristics, namely genetic algorithm and simulated annealing. A number of examples are provided to verify the model and assess the performance of the proposed heuristics. Experimental results indicate that DPSO outperforms the rival heuristics, with respect to some comparison metrics.

The generation and selection of single-domain, v region libraries from nurse sharks.

Science.gov (United States)

Flajnik, Martin F; Dooley, Helen

2009-01-01

The cartilaginous fish (sharks, skates, and rays) are the oldest phylogenetic group in which a human-type adaptive immune system and immunoglobulins (Igs) have been found. In addition to their conventional (heavy-light chain heterodimeric) isotypes, IgM and IgW, sharks produce the novel isotype, IgNAR, a heavy chain homodimer that does not associate with light chains. Instead, its variable (V) regions act as independent, soluble units in order to bind antigen. In this chapter, we detail our immunization protocol in order to raise a humoral IgNAR response in the nurse shark (Ginglymostoma cirratum) and the subsequent cloning of the single-domain V regions from this isotype in order to select antigen-specific binders by phage display.

Hydrogel Tethering Enhances Interdomain Stabilization of Single-Chain Antibodies

Energy Technology Data Exchange (ETDEWEB)

Xiong, Yijia [Department; Ford, Nicole R. [Marine; Hecht, Karen A. [Marine; Roesijadi, Guritno [Marine; Department; Squier, Thomas C. [Department

2017-10-12

Self-assembly of recombinant proteins within the biosilica of living diatoms represents a means to construct functional materials in a reproducible and scalable manner that enable applications that harness the inherent specificities of proteins to sense and respond to environmental cues. Here we describe the use of a silaffin-derived lysine-rich 39 amino-acid targeting sequence (Sil3T8) to direct a single chain fragment variable (scFv) antibody or an enhanced green fluorescent protein (EGFP) to assemble within the biosilica frustule, resulting in abundances in excess of 200,000 proteins per frustule. The fluorescence of either a derivative of trinitrotoluene (TNT) bound to the scFv or the endogenous fluorescence of EGFP was used to monitor pro-tein conformational dynamics, accessibility to external quenchers, binding affinity, and conformational stability. We find that proteins within isolated frustules undergo isotropic rotational motions with two-fold increases in rotational correlation times, which are indicative of weak macromolecular associations within the biosilica. Solvent accessibilities and high-affinity (pM) binding are comparable to those in solution. In contrast to solution conditions, scFv antibod-ies within the biosilica matrix retain their binding affinity in the presence of chaotropic agents (i.e., 8 M urea). These results argue that dramatic increases in protein conforma-tional stability within the biosilica frustule matrices arise through molecular crowding, acting to retain native protein folds and associated functionality to allow the utility of engineered proteins under a range of harsh environmental conditions associated with environmental sensing and industrial catalytic transformations.

Mesoscale simulation of semiflexible chains. I. Endpoint distribution and chain dynamics

Science.gov (United States)

Groot, Robert D.

2013-06-01

The endpoint distribution and dynamics of semiflexible fibers are studied by numerical simulation. A brief overview is given over the analytical theory of flexible and semiflexible polymers. In particular, a closed expression is given for the relaxation spectrum of wormlike chains, which determines polymer diffusion and rheology. Next a simulation model for wormlike chains with full hydrodynamic interaction is described, and relations for the bending and torsion modulus are given. Two methods are introduced to include torsion stiffness into the model. The model is validated by simulating single chains in a heat bath, and comparing the endpoint distribution of the chains with established Monte Carlo results. It is concluded that torsion stiffness leads to a slightly shorter effective persistence length for a given bending stiffness. To further validate the simulation model, polymer diffusion is studied for fixed persistence length and varying polymer length N. The diffusion constant shows crossover from Rouse (D ∝ N-1) to reptation behaviour (D ∝ N-2). The terminal relaxation time obtained from the monomer displacement is consistent with the theory of wormlike chains. The probability for chain crossing has also been studied. This probability is so low that it does not influence the present results.

British Museum Exhibition Review: The Jericho Skull, Creating an Ancestor

Directory of Open Access Journals (Sweden)

Cara Hirst

2017-03-01

Full Text Available The temporary exhibit at the British Museum, open 15th December-19th February, and located to the right of the main entrance in the Raymond and Beverly Sackler Gallery (Room 59; is dedicated to a single Neolithic crania from Jericho, known as the Jericho Skull. This exhibit demonstrates the value of relatively recent technologies in archaeological research, highlighting the previously hidden information made possible through CT scanning and the value of these methods in both archaeological research but also in communicating archaeology in a visually stimulating manner which allows an exhibit to take a single item, and create an in depth exhibit featuring both the original material and two cranial 3D prints along with a facial reconstruction.

Cooperation and profit allocation in distribution chains

NARCIS (Netherlands)

Guardiola, L.A.; Meca, A.; Timmer, Judith B.

2005-01-01

We study the coordination of actions and the allocation of profit in distribution chains under decentralized control. We consider distribution chains in which a single supplier supplies goods for replenishment of stocks of several retailers who, in turn, sell these goods to their own separate

Impact of charge carrier injection on single-chain photophysics of conjugated polymers

Energy Technology Data Exchange (ETDEWEB)

Hofmann, Felix J.; Vogelsang, Jan, E-mail: jan.vogelsang@physik.uni-regensburg.de; Lupton, John M. [Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg (Germany)

2016-06-27

Charges in conjugated polymer materials have a strong impact on the photophysics and their interaction with the primary excited state species has to be taken into account in understanding device properties. Here, we employ single-molecule spectroscopy to unravel the influence of charges on several photoluminescence (PL) observables. The charges are injected either stochastically by a photochemical process or deterministically in a hole-injection sandwich device configuration. We find that upon charge injection, besides a blue-shift of the PL emission and a shortening of the PL lifetime due to quenching and blocking of the lowest-energy chromophores, the non-classical photon arrival time distribution of the multichromophoric chain is modified towards a more classical distribution. Surprisingly, the fidelity of photon antibunching deteriorates upon charging, whereas one would actually expect the opposite: the number of chromophores to be reduced. A qualitative model is presented to explain the observed PL changes. The results are of interest to developing a microscopic understanding of the intrinsic charge-exciton quenching interaction in devices.

Supply Chain Coordination under Trade Credit and Quantity Discount with Sales Effort Effects

Directory of Open Access Journals (Sweden)

Zhihong Wang

2018-01-01

Full Text Available The purpose of this paper is to investigate the role of trade credit and quantity discount in supply chain coordination when the sales effort effect on market demand is considered. In this paper, we consider a two-echelon supply chain consisting of a single retailer ordering a single product from a single manufacturer. Market demand is stochastic and is influenced by retailer sales effort. We formulate an analytical model based on a single trade credit and find that the single trade credit cannot achieve the perfect coordination of the supply chain. Then, we develop a hybrid quantitative analytical model for supply chain coordination by coherently integrating incentives of trade credit and quantity discount with sales effort effects. The results demonstrate that, providing that the discount rate satisfies certain conditions, the proposed hybrid model combining trade credit and quantity discount will be able to effectively coordinate the supply chain by motivating retailers to exert their sales effort and increase product order quantity. Furthermore, the hybrid quantitative analytical model can provide great flexibility in coordinating the supply chain to achieve an optimal situation through the adjustment of relevant parameters to resolve conflict of interests from different supply chain members. Numerical examples are provided to demonstrate the effectiveness of the hybrid model.

A single-chain fusion molecule consisting of peptide, major histocompatibility gene complex class I heavy chain and beta2-microglobulin can fold partially correctly, but binds peptide inefficiently

DEFF Research Database (Denmark)

Sylvester-Hvid, C; Buus, S

1999-01-01

of a recombinant murine MHC-I molecule, which could be produced in large amounts in bacteria. The recombinant MHC-I protein was expressed as a single molecule (PepSc) consisting of the antigenic peptide linked to the MHC-I heavy chain and further linked to human beta2-microglobulin (hbeta2m). The PepSc molecule...... electrophoresis (SDS-PAGE). Serological analysis revealed the presence of some, but not all, MHC-I-specific epitopes. Biochemically, PepSc could bind peptide, however, rather ineffectively. We suggest that a partially correctly refolded MHC-I has been obtained....

A chiral mixed carboxylate, [Nd4(H2O)2(OOC(CH2)3COO)4(C2O4)2], exhibiting NLO properties

International Nuclear Information System (INIS)

Vaidhyanathan, R.; Natarajan, Srinivasan; Rao, C.N.R.

2004-01-01

Reaction of a mixture of neodymium carbonate, HCl, oxamic acid and glutaric acid under hydrothermal conditions gives rise to a new mixed carboxylate of neodymium, [Nd 4 (H 2 O) 2 (OOC(CH 2 ) 3 COO) 4 (C 2 O 4 ) 2 ], I. The structure, determined using single crystal X-ray diffraction, comprises a helical column formed by the grafting of the oxalate unit on to helical NdO 9 chains, cross-linked by the glutarate anions. It is noteworthy that the pitch of the helix is equivalent to the length of the oxalate unit. Furthermore, I shows about 1.1 times the SHG activity of urea

Determination of allergen specificity by heavy chains in grass pollen allergen-specific IgE antibodies.

Science.gov (United States)

Gadermaier, Elisabeth; Flicker, Sabine; Lupinek, Christian; Steinberger, Peter; Valenta, Rudolf

2013-04-01

Affinity and clonality of allergen-specific IgE antibodies are important determinants for the magnitude of IgE-mediated allergic inflammation. We sought to analyze the contribution of heavy and light chains of human allergen-specific IgE antibodies for allergen specificity and to test whether promiscuous pairing of heavy and light chains with different allergen specificity allows binding and might affect affinity. Ten IgE Fabs specific for 3 non-cross-reactive major timothy grass pollen allergens (Phl p 1, Phl p 2, and Phl p 5) obtained by means of combinatorial cloning from patients with grass pollen allergy were used to construct stable recombinant single chain variable fragments (ScFvs) representing the original Fabs and shuffled ScFvs in which heavy chains were recombined with light chains from IgE Fabs with specificity for other allergens by using the pCANTAB 5 E expression system. Possible ancestor genes for the heavy chain and light chain variable region-encoding genes were determined by using sequence comparison with the ImMunoGeneTics database, and their chromosomal locations were determined. Recombinant ScFvs were tested for allergen specificity and epitope recognition by means of direct and sandwich ELISA, and affinity by using surface plasmon resonance experiments. The shuffling experiments demonstrate that promiscuous pairing of heavy and light chains is possible and maintains allergen specificity, which is mainly determined by the heavy chains. ScFvs consisting of different heavy and light chains exhibited different affinities and even epitope specificity for the corresponding allergen. Our results indicate that allergen specificity of allergen-specific IgE is mainly determined by the heavy chains. Different heavy and light chain pairings in allergen-specific IgE antibodies affect affinity and epitope specificity and thus might influence clinical reactivity to allergens. Copyright © 2012 American Academy of Allergy, Asthma & Immunology. Published by

[Loading and strength of single- and multi-unit fixed dental prostheses 2. Strength

NARCIS (Netherlands)

Baat, C. de; Witter, D.J.; Meijers, C.C.A.J.; Vergoossen, E.L.; Creugers, N.H.J.

2014-01-01

The ultimate strength of a dental prosthesis is defined as the strongest loading force applied to the prosthesis until afracture failure occurs. Important key terms are strength, hardness, toughness and fatigue. Relatively prevalent complications of single- and multi-unit fixed dental prostheses are

Strain hardening in startup shear of long-chain branched polymer solutions.

Science.gov (United States)

Liu, Gengxin; Cheng, Shiwang; Lee, Hyojoon; Ma, Hongwei; Xu, Hongde; Chang, Taihyun; Quirk, Roderic P; Wang, Shi-Qing

2013-08-09

We show for the first time that entangled polymeric liquids containing long-chain branching can exhibit strain hardening upon startup shear. As the significant long-chain branching impedes chain disentanglement, Gaussian coils between entanglements can deform to reach the finite extensibility limit where the intrachain retraction force exceeds the value expected from the usual conformational entropy loss evaluated based on Gaussian chain statistics. The phenomenon is expected to lead to further theoretical understanding.

Enzymatic hydrolysis of short-chain lecithin/long-chain phospholipid unilamellar vesicles: sensitivity of phospholipases to matrix phase state.

Science.gov (United States)

Gabriel, N E; Agman, N V; Roberts, M F

1987-11-17

Short-chain lecithin/long-chain phospholipid unilamellar vesicles (SLUVs), unlike pure long-chain lecithin vesicles, are excellent substrates for water-soluble phospholipases. Hemolysis assays show that greater than 99.5% of the short-chain lecithin is partitioned in the bilayer. In these binary component vesicles, the short-chain species is the preferred substrate, while the long-chain phospholipid can be treated as an inhibitor (phospholipase C) or poor substrate (phospholipase A2). For phospholipase C Bacillus cereus, apparent Km and Vmax values show that bilayer-solubilized diheptanoylphosphatidylcholine (diheptanoyl-PC) is nearly as good a substrate as pure micellar diheptanoyl-PC, although the extent of short-chain lecithin hydrolysis depends on the phase state of the long-chain lipid. For phospholipase A2 Naja naja naja, both Km and Vmax values show a greater range: in a gel-state matrix, diheptanoyl-PC is hydrolyzed with micellelike kinetic parameters; in a liquid-crystalline matrix, the short-chain lecithin becomes comparable to the long-chain component. Both enzymes also show an anomalous increase in specific activity toward diheptanoyl-PC around the phase transition temperature of the long-chain phospholipid. Since the short-chain lecithin does not exhibit a phase transition, this must reflect fluctuations in head-group area or vertical motions of the short-chain lecithin caused by surrounding long-chain lecithin molecules. These results are discussed in terms of a specific model for SLUV hydrolysis and a general explanation for the "interfacial activation" observed with water-soluble phospholipases.

Partnering for change in chains : on the capacity of partnerships to promote sustainable change in global agricultural commodity chains

OpenAIRE

Bitzer, V.C.

2011-01-01

Partnerships mirror the changing nature of the relationships among state, business and civil society organizations, and are often considered as innovative mechanisms to overcome single actor failure in the context of globalization. This thesis analyzes the capacity of partnerships to promote sustainable change in global agricultural commodity chains, using the global coffee, cotton and cocoa chains as main fields of application for the empirical analyses. All three chains are characterized by...

Betaine-induced assembly of neutral infinite columns and chains of linked silver(I) polyhedra with embedded acetylenediide.

Science.gov (United States)

Zhao, Xiao-Li; Wang, Quan-Ming; Mak, Thomas C W

2005-03-18

Ten polymeric silver(I) double salts containing embedded acetylenediide: [(Ag2C2)2(AgCF3CO2)9(L1)3] (1), [(Ag2C2)2(AgCF3CO2)10(L2)3]H2O (2), [(Ag2C2)(AgCF3CO2)4(L3)(H2O)]0.75 H2O (3), [(Ag2C2)(1.5)(AgCF3CO2)7(L4)2] (4), [(Ag2C2)(AgCF3CO2)7(L5)2(H2O)] (5), [(Ag2C2) (AgC2F5CO2)7(L1)3(H2O)] (6), [(Ag2C2)(AgCF3CO2)7(L1)3(H2O)]2 H2O (7), [(Ag2C2)(AgC2F5CO2)6(L3)2] (8), [(Ag2C2)2(AgC2F5CO2)12(L4)2(H2O)4]H2O (9), and [(Ag2C2)(AgCF3CO2)6(L3)2(H2O)]H2O (10) have been isolated by varying the types of betaines, the perfluorocarboxylate ligands employed, and the reaction conditions. Single-crystal X-ray analysis has shown that 1-4 all have a columnar structure composed of fused silver(I) double cages, with C2(2-) species embedded in its stem and an exterior coat comprising anionic and zwitterionic carboxylates. For 5 and 6, single silver(I) cages are linked into a beaded chain through both types of carboxylate ligands. In 7, two different coordination modes of L1 connect the silver(I) polyhedra into a chain. For 8, the mu(2)-O,O' coordination mode of L3 connects the silver(I) double cages into a chain. Compound 9 exhibits a two-dimensional architecture generated from the cross-linkage of double cages by C2F5CO2-, L4, and [Ag2(C2F5CO2)2] units. Similar to 9, 10 is also a two-dimensional structure, which is formed by connecting the chains of linked double cages through [Ag2(CF3CO2)2] bridging.

Controlling Chain Conformations of High-k Fluoropolymer Dielectrics to Enhance Charge Mobilities in Rubrene Single-Crystal Field-Effect Transistors.

Science.gov (United States)

Adhikari, Jwala M; Gadinski, Matthew R; Li, Qi; Sun, Kaige G; Reyes-Martinez, Marcos A; Iagodkine, Elissei; Briseno, Alejandro L; Jackson, Thomas N; Wang, Qing; Gomez, Enrique D

2016-12-01

A novel photopatternable high-k fluoropolymer, poly(vinylidene fluoride-bromotrifluoroethylene) P(VDF-BTFE), with a dielectric constant (k) between 8 and 11 is demonstrated in thin-film transistors. Crosslinking P(VDF-BTFE) reduces energetic disorder at the dielectric-semiconductor interface by controlling the chain conformations of P(VDF-BTFE), thereby leading to approximately a threefold enhancement in the charge mobility of rubrene single-crystal field-effect transistors. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

76 FR 73760 - Culturally Significant Objects Imported for Exhibition Determinations: “The Holocaust”

Science.gov (United States)

2011-11-29

... Determinations: ``The Holocaust'' SUMMARY: Notice is hereby given of the following determinations: Pursuant to... the exhibition ``The Holocaust,'' imported from abroad for temporary exhibition within the United... United States Holocaust Memorial Museum, Washington, DC, from on or about December 7, 2011, until on or...

Preparation of polystyrene brush film by radical chain-transfer polymerization and micromechanical properties

Energy Technology Data Exchange (ETDEWEB)

Zhao Jing [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Chen Miao [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)], E-mail: miaochen99@yahoo.com; An Yanqing [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Liu Jianxi [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Yan Fengyuan [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)], E-mail: fyyan@lzb.ac.cn

2008-12-30

A radical chain-transfer polymerization technique has been applied to graft-polymerize brushes of polystyrene (PSt) on single-crystal silicon substrates. 3-Mercapto-propyltrimethoxysilane (MPTMS), as a chain-transfer agent for grafting, was immobilized on the silicon surface by a self-assembling process. The structure and morphology of the graft-functionalized silicon surfaces were characterized by the means of contact-angle measurement, ellipsometric thickness measurement, Fourier transformation infrared (FTIR) spectroscopy, and atomic force microscopy (AFM). The nanotribological and micromechanical properties of the as-prepared polymer brush films were investigated by frictional force microscopy (FFM), force-volume analysis and scratch test. The results indicate that the friction properties of the grafted polymer films can be improved significantly by the treatment of toluene, and the chemically bonded polystyrene film exhibits superior scratch resistance behavior compared with the spin-coated polystyrene film. The resultant polystyrene brush film is expected to develop as a potential lubrication coating for microelectromechanical systems (MEMS)

Entanglement entropy in random quantum spin-S chains

International Nuclear Information System (INIS)

Saguia, A.; Boechat, B.; Continentino, M. A.; Sarandy, M. S.

2007-01-01

We discuss the scaling of entanglement entropy in the random singlet phase (RSP) of disordered quantum magnetic chains of general spin S. Through an analysis of the general structure of the RSP, we show that the entanglement entropy scales logarithmically with the size of a block, and we provide a closed expression for this scaling. This result is applicable for arbitrary quantum spin chains in the RSP, being dependent only on the magnitude S of the spin. Remarkably, the logarithmic scaling holds for the disordered chain even if the pure chain with no disorder does not exhibit conformal invariance, as is the case for Heisenberg integer-spin chains. Our conclusions are supported by explicit evaluations of the entanglement entropy for random spin-1 and spin-3/2 chains using an asymptotically exact real-space renormalization group approach

Phase-coexistence simulations of fluid mixtures by the Markov Chain Monte Carlo method using single-particle models

KAUST Repository

Li, Jun

2013-09-01

We present a single-particle Lennard-Jones (L-J) model for CO2 and N2. Simplified L-J models for other small polyatomic molecules can be obtained following the methodology described herein. The phase-coexistence diagrams of single-component systems computed using the proposed single-particle models for CO2 and N2 agree well with experimental data over a wide range of temperatures. These diagrams are computed using the Markov Chain Monte Carlo method based on the Gibbs-NVT ensemble. This good agreement validates the proposed simplified models. That is, with properly selected parameters, the single-particle models have similar accuracy in predicting gas-phase properties as more complex, state-of-the-art molecular models. To further test these single-particle models, three binary mixtures of CH4, CO2 and N2 are studied using a Gibbs-NPT ensemble. These results are compared against experimental data over a wide range of pressures. The single-particle model has similar accuracy in the gas phase as traditional models although its deviation in the liquid phase is greater. Since the single-particle model reduces the particle number and avoids the time-consuming Ewald summation used to evaluate Coulomb interactions, the proposed model improves the computational efficiency significantly, particularly in the case of high liquid density where the acceptance rate of the particle-swap trial move increases. We compare, at constant temperature and pressure, the Gibbs-NPT and Gibbs-NVT ensembles to analyze their performance differences and results consistency. As theoretically predicted, the agreement between the simulations implies that Gibbs-NVT can be used to validate Gibbs-NPT predictions when experimental data is not available. © 2013 Elsevier Inc.

Equivalence of chain conformations in the surface region of a polymer melt and a single Gaussian chain nder critical conditions

NARCIS (Netherlands)

Skvortsov, A.M.; Leermakers, F.A.M.; Fleer, G.J.

2013-01-01

In the melt polymer conformations are nearly ideal according to Flory's ideality hypothesis. Silberberg generalized this statement for chains in the interfacial region. We check the Silberberg argument by analyzing the conformations of a probe chain end-grafted at a solid surface in a sea of

Investigations of model polymers: Dynamics of melts and statics of a long chain in a dilute melt of shorter chains

International Nuclear Information System (INIS)

Bishop, M.; Ceperley, D.; Frisch, H.L.; Kalos, M.H.

1982-01-01

We report additional results on a simple model of polymers, namely the diffusion in concentrated polymer systems and the static properties of one long chain in a dilute melt of shorter chains. It is found, for the polymer sizes and time scales amenable to our computer calculations, that there is as yet no evidence for a ''reptation'' regime in a melt. There is some indication of reptation in the case of a single chain moving through fixed obstacles. No statistically significant effect of the change, from excluded volume behavior of the long chain to ideal behavior as the shorter chains grow, is observed

The molecular spin filter constructed from 1D organic chain

International Nuclear Information System (INIS)

Chen, Wei; Xu, Ning; Wang, Baolin; Bian, Baoan

2014-01-01

We proposed a molecular spin filter, which is constructed from the 1D metallic organic chain (Fe n+1 (C 6 H 4 ) n ). The spin-polarized transport properties of the molecular spin filter are explored by combining density functional theory with nonequilibrium Green's function formalism. Theoretical results reveal that Fe n+1 (C 6 H 4 ) n molecular chain exhibits robust spin filtering effect, and only the spin-down electrons can transmit through the molecular chain. At the given bias voltage window [−1 eV,1 eV], the calculated spin filter efficiency is close to 100% in the case of n≥3. We find that the effect of spin polarization origin from both Fe n+1 and (C 6 H 4 ) n . In addition, negative difference resistance behavior appears in Fe n+1 (C 6 H 4 ) n molecular chain. The results can help us understand the spin transport properties of organic molecular chain. - Highlights: • Theoretical results reveal that Fe n+1 (C 6 H 4 ) n molecular chain exhibits robust spin filtering effect. • The effect of spin polarization origin from both of Fe n+1 and (C 6 H 4 ) n . • Negative difference resistance behavior appears in Fe n+1 (C 6 H 4 ) n molecular chain

Anomalous I-V curve for mono-atomic carbon chains

International Nuclear Information System (INIS)

Song Bo; Fang Haiping; Sanvito, Stefano

2010-01-01

The electronic transport properties of mono-atomic carbon chains were studied theoretically using a combination of density functional theory and the non-equilibrium Green's functions method. The I-V curves for the chains composed of an even number of atoms and attached to gold electrodes through sulfur exhibit two plateaus where the current becomes bias independent. In contrast, when the number of carbon atoms in the chain is odd, the electric current simply increases monotonically with bias. This peculiar behavior is attributed to dimerization of the chains, directly resulting from their one-dimensional nature. The finding is expected to be helpful in designing molecular devices, such as carbon-chain-based transistors and sensors, for nanoscale and biological applications.

A triple-bridged azido-Cu(II) chain compound fine-tuned by mixed carboxylate/ethanol linkers displays slow-relaxation and ferromagnetic order: synthesis, crystal structure, magnetic properties and DFT calculations.

Science.gov (United States)

Liu, Xiangyu; Chen, Sanping; Grancha, Thais; Pardo, Emilio; Ke, Hongshan; Yin, Bing; Wei, Qing; Xie, Gang; Gao, Shengli

2014-11-07

A new azido-Cu(II) compound, [Cu(4-fba)(N3)(C2H5OH)] (4-fba = 4-fluorobenzoic acid) (1), has been synthesized and characterized. The X-ray crystal structure analysis demonstrates that only one crystallographically independent Cu(II) ion in the asymmetric unit of 1 exhibits a stretched octahedral geometry in which two azido N atoms and two carboxylic O atoms locate in the equatorial square, while two ethanol O atoms occupy the apical positions, forming a 1D Cu(II) chain with an alternating triple-bridge of EO-azido, syn,syn-carboxylate, and μ2-ethanol. The title compound consists of ferromagnetically interacting ferromagnetic chains, which exhibit ferromagnetic order (T(c) = 7.0 K). The strong ferromagnetic coupling between adjacent Cu(II) ions within each chain is due to the countercomplementarity of the super-exchange pathways, whereas the ferromagnetic interchain interactions--responsible for the long-range magnetic ordering--are most likely due to the presence of coordinated ethanol molecules establishing hydrogen bonds with neighboring chains. DFT calculations have been performed on compound 1 to offer a qualitative theoretical explanation of the magnetic behavior.

The relationship between the connecting peptide of recombined single chain insulin and its biological function

Institute of Scientific and Technical Information of China (English)

HUANG; Yiding; (

2001-01-01

［1］Straus, D. S., Growth-stimulatory of insulin in vitro and in vivo, Endocr. Rev., 1984, 5(2): 356-369.［2］Svenningsen, A. F., Kanje, M., Insulin and the insulin-like growth factors I and II are mitogenic to cultured rat sciatic nerve segments and stimulate [3H] thuymidine incorporation through their respective receptors, Glia, 1996, 18(1): 68-72.［3］Ogihara, S., Yamada, M., Saito, T. et al., Insulin potentiates mitogenic effect of epidermal growth factor on cultured guinea pig gastric mucous cells, Am. J. Physiol., 1996, 271(1 Pt 1): G104-121.［4］Steiner, D. F., Oyer, P. E., The biosynthesis of insulin and a probable precursor of insulin by a human islet cell adenoma, Proc. Nalt. Acad. Sci. USA, 1967, 57(2): 473-480.［5］King, G. L., Kahn, C. R., The growth-promoting effects of insulin, in Growth and Maturation Factors(ed. Guroff, G.), New York: John Wiley & Sons, 1984, 223-265.［6］Peavy, D. E., Brunner, M. R., Duckworth, W. C. et al., Receptor binding and biological potency of several split forms (conversion intermediates) of human proinsulin, Studies in cultured IM-9 lymphocytes and in vivo and in vitro in rats, J. Biol. Chem., 1985, 260: 13989-13994.［7］Derewenda, U., Derewenda, Z., Dodson, E. J. et al., X-ray analysis of the single chain B29-A1 peptide-linked insulin molecule. A completely inactive analogue, J. Mol. Biol., 1991, 220: 425-433.［8］Hua, Q. X., Shoelson, S. E., Kochoyan, M. et al., Receptor binding redefined by a structural switch in a mutant human insulin, Nature, 1991, 354: 238-241.［9］Hua, Q. X., Gozani, S. N., Chance, R. E. et al., Structure of a protein in a kinetic trap, Nat. Struc. Boil, 1995, 2: 129-138.［10］Kristensen, C., Andersen, A. S., Hach, M., A single-chain insulin-like growth factor I/insulin hybrid binds with high affinity to the insulin receptor, Biochem. J., 1995, 305: 981-986.［11］Humbel, R. E., Insulin-like growth factors I and II, Euro. J. Biochem., 1990, 190: 445-462.［12］Cooke, R. M

α -decay chains of superheavy nuclei with Z =125

Science.gov (United States)

Santhosh, K. P.; Nithya, C.

2018-04-01

The decay properties of the isotopes of Z =125 within the range 303 ≤ A ≤ 339 are investigated. The calculation of proton separation energies reveals that isotopes 125-309303 may decay through proton emission. Four different mass tables are used to show the sensitivity of the mass models used to calculate the Q values as well as the α-decay half-lives. α -decay chains are predicted by comparing the α half-lives calculated within the Coulomb and proximity potential model for deformed nuclei (CPPMDN) [Nucl. Phys. A 850, 34 (2011), 10.1016/j.nuclphysa.2010.12.002] with the spontaneous fission half-lives using the shell-effect-dependent formula [Phys. Rev. C 94, 054621 (2016), 10.1103/PhysRevC.94.054621]. It is seen that isotopes 125,311310 show 6α chains. 5α chains can be seen from isotopes 125-318312. Isotopes 125,320319 exhibit 2α chains and 323125 exhibits 1α chain. All the other isotopes, that is, 125 321 ,322 ,324 -339 may decay through spontaneous fission. The α half-lives using CPPMDN are compared with five other theoretical formalisms and are seen to be matching with each other. We hope that our studies will be helpful in designing future experiments to explore the island of stability.

Solvent Exchange Rates of Side-chain Amide Protons in Proteins

International Nuclear Information System (INIS)

Rajagopal, Ponni; Jones, Bryan E.; Klevit, Rachel E.

1998-01-01

Solvent exchange rates and temperature coefficients for Asn/Gln side-chain amide protons have been measured in Escherichia coli HPr. The protons of the eight side-chain amide groups (two Asn and six Gln) exhibit varying exchange rates which are slower than some of the fast exchanging backbone amide protons. Differences in exchange rates of the E and Z protons of the same side-chain amide group are obtained by measuring exchange rates at pH values > 8. An NOE between a side-chain amide proton and a bound water molecule was also observed

A single-supply, high rate, small size and cheap electronic chain for 3He neutron counters

International Nuclear Information System (INIS)

Boffa, A.; Fazzi, A.; Pirovano, C.; Varoli, V.

1996-01-01

The paper describes a complete counting chain (charge preamplifier, shaping amplifier and threshold discriminator) devoted to 3 He neutron detectors. Since it is characterized by single supply operation, high counting rate, small size and low cost, it is well suited for high efficiency neutron well detectors where a large number (10 - 100) of counting tubes are used. Such detectors are commonly used for verification of Plutonium stocks. The preamplifier adopts an innovative circuit with the gate of the input JFET floating and a DC feedback loop that stabilizes the output voltage acting on the input cascode second transistor. Static and dynamic analysis, including the effects of the detector bias network, is reported. The shaping amplifier transfer function is a fifth order approximation of the gaussian response. All the complex pole pairs are realized with a single fourth order Voltage Controlled Voltage Source cell thus minimizing component count. Experimental signals and spectra, obtained with shaping time constants in the 1 μs - 100 ns range, are reported and discussed

Design and Generation of Humanized Single-chain Fv Derived from Mouse Hybridoma for Potential Targeting Application.

Science.gov (United States)

Khantasup, Kannika; Chantima, Warangkana; Sangma, Chak; Poomputsa, Kanokwan; Dharakul, Tararaj

2015-12-01

Single-chain variable antibody fragments (scFvs) are attractive candidates for targeted immunotherapy in several human diseases. In this study, a concise humanization strategy combined with an optimized production method for humanizing scFvs was successfully employed. Two antibody clones, one directed against the hemagglutinin of H5N1 influenza virus, the other against EpCAM, a cancer biomarker, were used to demonstrate the validity of the method. Heavy chain (VH) and light chain (VL) variable regions of immunoglobulin genes from mouse hybridoma cells were sequenced and subjected to the construction of mouse scFv 3-D structure. Based on in silico modeling, the humanized version of the scFv was designed via complementarity-determining region (CDR) grafting with the retention of mouse framework region (FR) residues identified by primary sequence analysis. Root-mean-square deviation (RMSD) value between mouse and humanized scFv structures was calculated to evaluate the preservation of CDR conformation. Mouse and humanized scFv genes were then constructed and expressed in Escherichia coli. Using this method, we successfully generated humanized scFvs that retained the targeting activity of their respective mouse scFv counterparts. In addition, the humanized scFvs were engineered with a C-terminal cysteine residue (hscFv-C) for site-directed conjugation for use in future targeting applications. The hscFv-C expression was extensively optimized to improve protein production yield. The protocol yielded a 20-fold increase in production of hscFv-Cs in E. coli periplasm. The strategy described in this study may be applicable in the humanization of other antibodies derived from mouse hybridoma.

Magnetotransport and magnetism in single-crystal PrBa2Cu3O7-δ

International Nuclear Information System (INIS)

Browning, V.M.; Osofsky, M.S.; Byers, J.M.; Ehrlich, A.C.; Dosseul, F.

1996-01-01

The PrBa 2 Cu 3 O 7-δ (Pr 123) system is known to exhibit antiferromagnetic ordering of the Cu spins in the Cu-O planes and chains, in addition to the observed antiferromagnetism due to the ordering of the Pr ions. The antiferromagnetism of the Cu-O planes is generally associated with the insulating nature of transport in Pr 123 and electrical conduction is believed to result through open-quote open-quote hopping close-quote close-quote transport between disordered Cu-O chain segments. However, the possible effects of magnetic ordering in the Cu-O chains on transport properties have not been discussed. If the Cu-O chains play a dominant role in the electrical transport (as suggested by many of the popular theories), then the magnetic ordering of the chains should also be seen in the transport properties. We present magnetization and magnetotransport measurements on single crystal Pr 123 samples which suggest that the magnetism associated with the Cu-O chains does indeed mediate transport in this system. These results confirm that the chains play a significant role in the transport properties and underscore the need for further study of the interplay between magnetism and transport in Pr 123

Primitive chain network simulations of probe rheology.

Science.gov (United States)

Masubuchi, Yuichi; Amamoto, Yoshifumi; Pandey, Ankita; Liu, Cheng-Yang

2017-09-27

Probe rheology experiments, in which the dynamics of a small amount of probe chains dissolved in immobile matrix chains is discussed, have been performed for the development of molecular theories for entangled polymer dynamics. Although probe chain dynamics in probe rheology is considered hypothetically as single chain dynamics in fixed tube-shaped confinement, it has not been fully elucidated. For instance, the end-to-end relaxation of probe chains is slower than that for monodisperse melts, unlike the conventional molecular theories. In this study, the viscoelastic and dielectric relaxations of probe chains were calculated by primitive chain network simulations. The simulations semi-quantitatively reproduced the dielectric relaxation, which reflects the effect of constraint release on the end-to-end relaxation. Fair agreement was also obtained for the viscoelastic relaxation time. However, the viscoelastic relaxation intensity was underestimated, possibly due to some flaws in the model for the inter-chain cross-correlations between probe and matrix chains.

Multiple single-unit long-term tracking on organotypic hippocampal slices using high-density microelectrode arrays

Directory of Open Access Journals (Sweden)

Wei Gong

2016-11-01

Full Text Available A novel system to cultivate and record from organotypic brain slices directly on high-density microelectrode arrays (HD-MEA was developed. This system allows for continuous recording of electrical activity of specific individual neurons at high spatial resolution while monitoring at the same time, neuronal network activity. For the first time, the electrical activity patterns of single neurons and the corresponding neuronal network in an organotypic hippocampal slice culture were studied during several consecutive weeks at daily intervals. An unsupervised iterative spike-sorting algorithm, based on PCA and k-means clustering, was developed to assign the activities to the single units. Spike-triggered average extracellular waveforms of an action potential recorded across neighboring electrodes, termed ‘footprints’ of single-units were generated and tracked over weeks. The developed system offers the potential to study chronic impacts of drugs or genetic modifications on individual neurons in slice preparations over extended times.

The decision-making in the internationalization of brazilian franchising chains

Directory of Open Access Journals (Sweden)

Nadia Wacila Hanania Vianna

2014-04-01

Full Text Available This research aimed to understand how the decision making process regarding the internationalization of Brazilian franchise chains occurred. This work intended to learn the motivation for internationalization, and the methods used in decision-making. The results obtained from two franchise chains revealed the adoption of two different decision processes: one where the decision was induced by an interested party in obtaining the international franchise and the other by the franchisor. The entry modes chosen by these chains were distinct (establishment of a wholly owned unit and a franchised unit; these choices conditioned the following steps in the internationalization process.

Current transport properties and phase diagram of a Kitaev chain with long-range pairing

Science.gov (United States)

Giuliano, Domenico; Paganelli, Simone; Lepori, Luca

2018-04-01

We describe a method to probe the quantum phase transition between the short-range topological phase and the long-range topological phase in the superconducting Kitaev chain with long-range pairing, both exhibiting subgap modes localized at the edges. The method relies on the effects of the finite mass of the subgap edge modes in the long-range regime (which survives in the thermodynamic limit) on the single-particle scattering coefficients through the chain connected to two normal leads. Specifically, we show that, when the leads are biased at a voltage V with respect to the superconducting chain, the Fano factor is either zero (in the short-range correlated phase) or 2 e (in the long-range correlated phase). As a result, we find that the Fano factor works as a directly measurable quantity to probe the quantum phase transition between the two phases. In addition, we note a remarkable "critical fractionalization effect" in the Fano factor, which is exactly equal to e along the quantum critical line. Finally, we note that a dual implementation of our proposed device makes it suitable as a generator of large-distance entangled two-particle states.

Ia Afferent input alters the recruitment thresholds and firing rates of single human motor units.

Science.gov (United States)

Grande, G; Cafarelli, E

2003-06-01

Vibration of the patellar tendon recruits motor units in the knee extensors via excitation of muscle spindles and subsequent Ia afferent input to the alpha-motoneuron pool. Our first purpose was to determine if the recruitment threshold and firing rate of the same motor unit differed when recruited involuntarily via reflex or voluntarily via descending spinal pathways. Although Ia input is excitatory to the alpha-motoneuron pool, it has also been shown paradoxically to inhibit itself. Our second purpose was to determine if vibration of the patellar tendon during a voluntary knee extension causes a change in the firing rate of already recruited motor units. In the first protocol, 10 subjects voluntarily reproduced the same isometric force profile of the knee extensors that was elicited by vibration of the patellar tendon. Single motor unit recordings from the vastus lateralis (VL) were obtained with tungsten microelectrodes and unitary behaviour was examined during both reflex and voluntary knee extensions. Recordings from 135 single motor units showed that both recruitment thresholds and firing rates were lower during reflex contractions. In the second protocol, 7 subjects maintained a voluntary knee extension at 30 N for approximately 40-45 s. Three bursts of patellar tendon vibration were superimposed at regular intervals throughout the contraction and changes in the firing rate of already recruited motor units were examined. A total of 35 motor units were recorded and each burst of superimposed vibration caused a momentary reduction in the firing rates and recruitment of additional units. Our data provide evidence that Ia input modulates the recruitment thresholds and firing rates of motor units providing more flexibility within the neuromuscular system to grade force at low levels of force production.

Interlocking Molecular Gear Chains Built on Surfaces.

Science.gov (United States)

Zhao, Rundong; Qi, Fei; Zhao, Yan-Ling; Hermann, Klaus E; Zhang, Rui-Qin; Van Hove, Michel A

2018-05-17

Periodic chains of molecular gears in which molecules couple with each other and rotate on surfaces have been previously explored by us theoretically using ab initio simulation tools. On the basis of the knowledge and experience gained about the interactions between neighboring molecular gears, we here explore the transmission of rotational motion and energy over larger distances, namely, through a longer chain of gear-like passive "slave" molecules. Such microscopic gears exhibit quite different behaviors compared to rigid cogwheels in the macroscopic world due to their structural flexibility affecting intermolecular interaction. Here, we investigate the capabilities of such gear chains and reveal the mechanisms of the transmission process in terms of both quantum-level density functional theory (DFT) and simple classical mechanics. We find that the transmission of rotation along gear chains depends strongly on the gear-gear distance: short distances can cause tilting of gears and even irregular "creep-then-jump" (or "stick-slip") motion or expulsion of gears; long gear-gear distances cause weak coupling between gears, slipping and skipping. More importantly, for transmission of rotation at intermediate gear-gear distances, our modeling clearly exhibits the relative roles of several important factors: flexibility of gear arms, axles, and supports, as well as resulting rotational delays, slippages, and thermal and other effects. These studies therefore allow better informed design of future molecular machine components involving motors, gears, axles, etc.

Inulin isoforms differ by repeated additions of one crystal unit cell

Science.gov (United States)

Cooper, Peter D.; Barclay, Thomas G.; Ginic-Markovic, Milena; Gerson, Andrea R.; Petrovsky, Nikolai

2014-01-01

Inulin isoforms, especially delta inulin, are important biologically as immune activators and clinically as vaccine adjuvants. In exploring action mechanisms, we previously found regular increments in thermal properties of the seven-member inulin isoform series that suggested regular additions of some energetic structural unit. Because the previous isolates carried additional longer chains that masked defining ranges, these were contrasted with new isoform isolates comprising only inulin chain lengths defining that isoform. The new series began with 19 fructose units per chain (alpha-1 inulin), increasing regularly by 6 fructose units per isoform. Thus the ‘energetic unit’ equates to 6 fructose residues per chain. All isoforms showed indistinguishable X-ray diffraction patterns that were also identical with known inulin crystals. We conclude that an ‘energetic unit’ equates to one helix turn of 6 fructose units per chain as found in one unit cell of the inulin crystal. Each isoform chain comprised progressively more helix turns plus one additional fructose and glucose residues per chain. PMID:24528745

Step Density Profiles in Localized Chains

Science.gov (United States)

De Roeck, Wojciech; Dhar, Abhishek; Huveneers, François; Schütz, Marius

2017-06-01

We consider two types of strongly disordered one-dimensional Hamiltonian systems coupled to baths (energy or particle reservoirs) at the boundaries: strongly disordered quantum spin chains and disordered classical harmonic oscillators. These systems are believed to exhibit localization, implying in particular that the conductivity decays exponentially in the chain length L. We ask however for the profile of the (very slowly) transported quantity in the steady state. We find that this profile is a step-function, jumping in the middle of the chain from the value set by the left bath to the value set by the right bath. This is confirmed by numerics on a disordered quantum spin chain of 9 spins and on much longer chains of harmonic oscillators. From theoretical arguments, we find that the width of the step grows not faster than √{L}, and we confirm this numerically for harmonic oscillators. In this case, we also observe a drastic breakdown of local equilibrium at the step, resulting in a heavily oscillating temperature profile.

Block copolymer systems: from single chain to self-assembled nanostructures.

Science.gov (United States)

Giacomelli, Cristiano; Schmidt, Vanessa; Aissou, Karim; Borsali, Redouane

2010-10-19

Recent advances in the field of macromolecular engineering applied to the fabrication of nanostructured materials using block copolymer chains as elementary building blocks are described in this feature article. By highlighting some of our work in the area and accounting for the contribution of other groups, we discuss the relationship between the physical-chemical properties of copolymer chains and the characteristics of nano-objects originating from their self-assembly in solution and in bulk, with emphasis on convenient strategies that allow for the control of composition, functionality, and topology at different levels of sophistication. In the case of micellar nanoparticles in solution, in particular, we present approaches leading to morphology selection via macromolecular architectural design, the functionalization of external solvent-philic shells with biomolecules (polysaccharides and proteins), and the maximization of micelle loading capacity by the suitable choice of solvent-phobic polymer segments. The fabrication of nanomaterials mediated by thin block copolymer films is also discussed. In this case, we emphasize the development of novel polymer chain manipulation strategies that ultimately allow for the preparation of precisely positioned nanodomains with a reduced number of defects via block-selective chemical reactivity. The challenges facing the soft matter community, the urgent demand to convert huge public and private investments into consumer products, and future possible directions in the field are also considered herein.

Science Fiction Exhibits as STEM Gateways

Science.gov (United States)

Robie, Samantha

Women continue to hold less than a quarter of all STEM jobs in the United States, prompting many museums to develop programs and exhibits with the express goal of interesting young girls in scientific fields. At the same time, a number of recent museum exhibits have harnessed the popularity of pop culture and science fiction in order to interest general audiences in STEM subject matter, as well as using the exhibits as springboards to expand or shift mission goals and focus. Because science fiction appears to be successful at raising interest in STEM fields, it may be an effective way to garner the interest of young girls in STEM in particular. This research seeks to describe the ways in which museums are currently using science fiction exhibits to interest young girls in STEM fields and careers. Research focused on four institutions across the country hosting three separate exhibits, and included staff interviews and content analysis of exhibit descriptions, promotional materials, a summative evaluation and supplementary exhibit productions. In some ways, science fiction exhibits do serve young girls, primarily through the inclusion of female role models, staff awareness, and prototype testing to ensure interactives are attractive to girls as well as to boys. However, STEM appears to be underutilized, which may be partly due to a concern within the field that the outcome of targeting a specific gender could be construed as "stereotyping".

Effect of chain stiffness on the structure of single-chain polymer nanoparticles

DEFF Research Database (Denmark)

Moreno, Angel J; Bacova, Petra; Lo Verso, Federica

2018-01-01

of the domains is in all cases similar to that of Gaussian chains or rings, irrespective of the stiffness and degree of cross-linking. It is the spatial arrangement of the domains which determines the global structure of the SCNP (sparse Gaussian-like object or crumpled globule). Since intramolecular stiffness...... or 'crumpled' globular behaviour for very stiff SCNPs. We characterize domains in the SCNPs. These are weakly deformable regions that can be seen as disordered analogues of domains in disordered proteins. Increasing stiffness leads to bigger and less deformable domains. Surprisingly, the scaling behaviour...... can be varied through the specific chemistry of the precursor or by introducing bulky side groups in its backbone, our results propose a new strategy to tune the global structure of SCNPs. ....

77 FR 3320 - Culturally Significant Objects Imported for Exhibition Determinations: “Print/Out”

Science.gov (United States)

2012-01-23

... that the exhibition or display of the exhibit objects at the Museum of Modern Art, New York, New York... from abroad for temporary exhibition within the United States, are of cultural significance. The...

77 FR 26353 - Culturally Significant Objects Imported for Exhibition Determinations: “Lygia Clark”

Science.gov (United States)

2012-05-03

... that the exhibition or display of the exhibit objects at the Museum of Modern Art, New York, New York... in the exhibition ``Lygia Clark,'' within the United States, are of cultural significance. The...

Vastus lateralis surface and single motor unit EMG following submaximal shortening and lengthening contractions

NARCIS (Netherlands)

Altenburg, T.M.; de Ruiter, C.J.; Verdijk, P.W.L.; van Mechelen, W.; de Haan, A.

2008-01-01

A single shortening contraction reduces the force capacity of muscle fibers, whereas force capacity is enhanced following lengthening. However, how motor unit recruitment and discharge rate (muscle activation) are adapted to such changes in force capacity during submaximal contractions remains

Heavy chain only antibodies

DEFF Research Database (Denmark)

Moghimi, Seyed Moein; Rahbarizadeh, Fatemeh; Ahmadvand, Davoud

2013-01-01

Unlike conventional antibodies, heavy chain only antibodies derived from camel contain a single variable domain (VHH) and two constant domains (CH2 and CH3). Cloned and isolated VHHs possess unique properties that enable them to excel conventional therapeutic antibodies and their smaller antigen...

CERN Industrials Exhibitions - Over 30 Years of Tradition

CERN Multimedia

2001-01-01

Industrial exhibitions have been part of the CERN landscape for 33 years. At least once each year several companies from the same country come to CERN to present their products and services. Now, a new scheme of one-day visits is giving potential exhibitors at CERN a lighter option. The United Kingdom inaugurated the Industrial Exhibitions in 1968, and it wasn't till 1971 that other countries staged exhibitions at CERN. This photo was taken in 1969, at the second British exhibition, where 16 companies were present. Four years after joining CERN, Poland inaugurated its first exhibition at CERN in 1995 in the presence of the former Director-General Chris Llewellyn-Smith. Almost all the Member States have held industrial exhibitions at the Organization. May '68 wasn't only revolutionary in Paris. For the very first time, an industrial exhibition took place at CERN. Great Britain was first to come with eight companies and remains until this day the most devoted country to the programme with 17 exhibitions and ...

78 FR 8682 - Culturally Significant Objects Imported for Exhibition Determinations: “Henri Labrouste...

Science.gov (United States)

2013-02-06

... exhibition or display of the exhibit objects at the Museum of Modern Art, New York, New York, from on or... abroad for temporary exhibition within the United States, are of cultural significance. The objects are...

78 FR 62355 - Culturally Significant Objects Imported for Exhibition Determinations: “Ileana Sonnabend...

Science.gov (United States)

2013-10-18

... exhibition or display of the exhibit objects at the Museum of Modern Art, New York, New York, from on or... abroad for temporary exhibition within the United States, are of cultural significance. The objects are...

Decentralized Method for Load Sharing and Power Management in a Hybrid Single/Three-Phase-Islanded Microgrid Consisting of Hybrid Source PV/Battery Units

DEFF Research Database (Denmark)

Karimi, Yaser; Oraee, Hashem; Guerrero, Josep M.

2017-01-01

This paper proposes a new decentralized power management and load sharing method for a photovoltaic based, hybrid single/three-phase islanded microgrid consisting of various PV units, battery units and hybrid PV/battery units. The proposed method is not limited to the systems with separate PV...... in different load, PV generation and battery conditions is validated experimentally in a microgrid lab prototype consisted of one three-phase unit and two single-phase units....

Single chain Fc-dimer-human growth hormone fusion protein for improved drug delivery.

Science.gov (United States)

Zhou, Li; Wang, Hsuan-Yao; Tong, Shanshan; Okamoto, Curtis T; Shen, Wei-Chiang; Zaro, Jennica L

2017-02-01

Fc fusion protein technology has been successfully used to generate long-acting forms of several protein therapeutics. In this study, a novel Fc-based drug carrier, single chain Fc-dimer (sc(Fc) 2 ), was designed to contain two Fc domains recombinantly linked via a flexible linker. Since the Fc dimeric structure is maintained through the flexible linker, the hinge region was omitted to further stabilize it against proteolysis and reduce FcγR-related effector functions. The resultant sc(Fc) 2 candidate preserved the neonatal Fc receptor (FcRn) binding. sc(Fc) 2 -mediated delivery was then evaluated using a therapeutic protein with a short plasma half-life, human growth hormone (hGH), as the protein drug cargo. This novel carrier protein showed a prolonged in vivo half-life and increased hGH-mediated bioactivity compared to the traditional Fc-based drug carrier. sc(Fc) 2 technology has the potential to greatly advance and expand the use of Fc-technology for improving the pharmacokinetics and bioactivity of protein therapeutics. Copyright © 2016 Elsevier Ltd. All rights reserved.

Human α2-HS-glycoprotein: the A and B chains with a connecting sequence are encoded by a single mRNA transcript

International Nuclear Information System (INIS)

Lee, C.C.; Bowman, B.H.; Yang, F.

1987-01-01

The α 2 -HS-glycoprotein (AHSG) is a plasma protein reported to play roles in bone mineralization and in the immune response. It is composed of two subunits, the A and B chains. Recombinant plasmids containing human cDNA AHSG have been isolated by screening an adult human liver library with a mixed oligonucleotide probe. The cDNA clones containing AHSG inserts span approximately 1.5 kilobase pairs and include the entire AHSG coding sequence, demonstrating that the A and B chains are encoded by a single mRNA transcript. The cDNA sequence predicts an 18-amino-acid signal peptide, followed by the A-chain sequence of AHSG. A heretofore unseen connecting sequence of 40 amino acids was deduced between the A- and B-chain sequences. The connecting sequence demonstrates the unique amino acid doublets and collagen triplets found in the A and B chains; it is not homologous with other reported amino acid sequences. The connecting sequence may be cleaved in a posttranslational step by limited proteolysis before mature AHSG is released into the circulation or may vary in its presence because of alternative processing. The AHSG cDNA was utilized for mapping the AHSG gene to the 3q21→qter region of human chromosome 3. The availability of the AHSG cDNA clone will facilitate the analysis of its genetic control and gene expression during development and bone formation

Shopper Loyalty to Whom? Chain Versus Outlet Loyalty in the Context of Store Acquisitions

NARCIS (Netherlands)

van Lin, Arjen; Gijsbrechts, E.

2014-01-01

When patronizing stores, consumers may exhibit loyalty not only to a retail chain but also to a specific outlet. This distinction is important in a dynamic retail environment: if a store changes ownership, chain loyalty makes customers inclined to seek out another outlet of the former chain, whereas

Shopper loyalty to whom? Chain versus outlet loyalty in the context of store acquisitions

NARCIS (Netherlands)

van Lin, A.I.J.G.; Gijsbrechts, E.

When patronizing stores, consumers may exhibit loyalty not only to a retail chain but also to a specific outlet. This distinction is important in a dynamic retail environment: if a store changes ownership, chain loyalty makes customers inclined to seek out another outlet of the former chain, whereas

A possibility for generation of two species of charge carriers along main-chain and side-chains for a π-conjugated polymer

International Nuclear Information System (INIS)

Kudo, Yuki; Kawabata, Kohsuke; Goto, Hiromasa

2013-01-01

Iodide doping produces charge carriers in π-conjugated polymers. Solitons can be generated in the case of polyacetylene, and polarons in the case of aromatic-type conjugated polymers. We synthesized a conjugated main-chain/side-chain polymer, which consists of polyene in the main-chain and aromatic-type conjugated units in the side-chains. Based on the SSH (Su, Schrieffer, Heeger) theoretical model of solitons in one-dimensional conjugated polymers, we experimentally carried out chemical doping to the main-chain/side-chains conjugated polymer. Generation of the charge carriers was examined by electron spin resonance spectroscopy. This study may lead to realization of a dual doping system of solitons and polarons in π-conjugation expanded to two-dimensional directions in polymers.

Anti-Human Endoglin (hCD105) Immunotoxin-Containing Recombinant Single Chain Ribosome-Inactivating Protein Musarmin 1.

Science.gov (United States)

Barriuso, Begoña; Antolín, Pilar; Arias, F Javier; Girotti, Alessandra; Jiménez, Pilar; Cordoba-Diaz, Manuel; Cordoba-Diaz, Damián; Girbés, Tomás

2016-06-10

Endoglin (CD105) is an accessory component of the TGF-β receptor complex, which is expressed in a number of tissues and over-expressed in the endothelial cells of tumor neovasculature. Targeting endoglin with immunotoxins containing type 2 ribosome-inactivating proteins has proved an effective tool to reduce blood supply to B16 mice tumor xenografts. We prepared anti-endoglin immunotoxin (IT)-containing recombinant musarmin 1 (single chain ribosome-inactivating proteins) linked to the mouse anti-human CD105 44G4 mouse monoclonal antibody via N-succinimidyl 3-(2-pyridyldithio) propionate (SPDP). The immunotoxin specifically killed L929 fibroblast mouse cells transfected with the short form of human endoglin with IC50 values in the range of 5 × 10(-10) to 10(-9) M.

76 FR 29286 - Culturally Significant Objects Imported for Exhibition Determinations: “Pissarro's People”

Science.gov (United States)

2011-05-20

... DEPARTMENT OF STATE [Public Notice 7462] Culturally Significant Objects Imported for Exhibition Determinations: ``Pissarro's People'' SUMMARY: Notice is hereby given of the following determinations: Pursuant... the exhibition ``Pissarro's People,'' imported from abroad for temporary exhibition within the United...

Lamellar Microdomains of Block-Copolymer-Based Ionic Supramolecules Exhibiting a Hierarchical Self-Assembly

DEFF Research Database (Denmark)

Ayoubi, Mehran Asad; Almdal, Kristoffer; Zhu, Kaizheng

2014-01-01

(Cn; n = 8, 12, and 16) trimethylammonium counterions (i.e., side chains) at various ion (pair) fractions X [i.e., counterion/side-chain grafting density; X = number of alkyl counterions (i.e., side chains) per acidic group of the parent PMAA block] these L-b-AC ionic supramolecules exhibit...... a spherical-in-lamellar hierarchical self-assembly. For these systems, (1) the effective Flory-Huggins interaction parameter between L- and AC-blocks chi'(Cn/x) was extracted, and (2) analysis of the lamellar microdomains showed that when there is an increase in X, alkyl counterion (i.e., side chain) length l......Based on a parent diblock copolymer of poly(styrene)-b-poly(methacrylic acid), PS-b-PMAA, linear-b-amphiphilic comb (L-b-AC) ionic supramolecules [Soft Matter 2013, 9, 1540-1555] are synthesized in which the poly(methacrylate) backbone of the ionic supramolecular AC-block is neutralized by alkyl...

Finite-temperature dynamic structure factor of the spin-1 XXZ chain with single-ion anisotropy

Science.gov (United States)

Lange, Florian; Ejima, Satoshi; Fehske, Holger

2018-02-01

Improving matrix-product state techniques based on the purification of the density matrix, we are able to accurately calculate the finite-temperature dynamic response of the infinite spin-1 XXZ chain with single-ion anisotropy in the Haldane, large-D , and antiferromagnetic phases. Distinct thermally activated scattering processes make a significant contribution to the spectral weight in all cases. In the Haldane phase, intraband magnon scattering is prominent, and the on-site anisotropy causes the magnon to split into singlet and doublet branches. In the large-D phase response, the intraband signal is separated from an exciton-antiexciton continuum. In the antiferromagnetic phase, holons are the lowest-lying excitations, with a gap that closes at the transition to the Haldane state. At finite temperatures, scattering between domain-wall excitations becomes especially important and strongly enhances the spectral weight for momentum transfer π .

Scattering of waves by impurities in precompressed granular chains.

Science.gov (United States)

Martínez, Alejandro J; Yasuda, Hiromi; Kim, Eunho; Kevrekidis, P G; Porter, Mason A; Yang, Jinkyu

2016-05-01

We study scattering of waves by impurities in strongly precompressed granular chains. We explore the linear scattering of plane waves and identify a closed-form expression for the reflection and transmission coefficients for the scattering of the waves from both a single impurity and a double impurity. For single-impurity chains, we show that, within the transmission band of the host granular chain, high-frequency waves are strongly attenuated (such that the transmission coefficient vanishes as the wavenumber k→±π), whereas low-frequency waves are well-transmitted through the impurity. For double-impurity chains, we identify a resonance-enabling full transmission at a particular frequency-in a manner that is analogous to the Ramsauer-Townsend (RT) resonance from quantum physics. We also demonstrate that one can tune the frequency of the RT resonance to any value in the pass band of the host chain. We corroborate our theoretical predictions both numerically and experimentally, and we directly observe almost complete transmission for frequencies close to the RT resonance frequency. Finally, we show how this RT resonance can lead to the existence of reflectionless modes in granular chains (including disordered ones) with multiple double impurities.

Phase transitions and Heisenberg limited metrology in an Ising chain interacting with a single-mode cavity field

DEFF Research Database (Denmark)

Gammelmark, Søren; Mølmer, Klaus

2011-01-01

We investigate the thermodynamics of a combined Dicke and Ising model that exhibits a rich phenomenology arising from the second-order and quantum phase transitions from the respective models. The partition function is calculated using mean-field theory, and the free energy is analyzed in detail...... to determine the complete phase diagram of the system. The analysis reveals both first- and second-order Dicke phase transitions into a super-radiant state, and the cavity mean field in this regime acts as an effective magnetic field, which restricts the Ising chain dynamics to parameter ranges away from...... the Ising phase transition. Physical systems with first-order phase transitions are natural candidates for metrology and calibration purposes, and we apply filter theory to show that the sensitivity of the physical system to temperature and external fields reaches the 1/N Heisenberg limit....

Peritonitis: 10 years' experience in a single surgical unit.

Science.gov (United States)

Agarwal, Nitin; Saha, Sudipta; Srivastava, Anurag; Chumber, Sunil; Dhar, Anita; Garg, Sanket

2007-01-01

Peritonitis secondary to gut perforation is still one of the commonest surgical emergencies in India and is associated with high morbidity and mortality. The present study examines the aetiology and outcome of peritonitis cases operated on in our surgical unit, and compares our findings with those of previous studies performed between 1981 and 1991. A retrospective study of 260 peritonitis patients operated on in a single surgical unit from 1995 to 2006 was done and data involving clinical presentation, operative findings and post-operative course were studied and analysed. Causes of peritonitis were small bowel perforation (96 ileal, 17 jejunal), peptic perforation (45 duodenal, 16 gastric), appendicular perforation (36), primary peritonitis (8), and others (42). The incidence of major complications was 25% (burst-11%, leak-5%, intraabdominal abscess-5%, multi-organ failure-6.5%). The overall mortality was 10%. High mortality was observed in jejunal, gall bladder and liver abscess perforation cases (> 20%). Histopathological evaluation (143 specimens) revealed tuberculosis in 42 (mostly small bowel), malignancy in 8, and inflammation in the rest. Comparisons with a similar study carried out in the same unit and published in 1995 revealed similar demographic features and mortality, but a change in the most common cause (peptic ulcer perforation to small bowel perforation), and an increased performance of enterostomy compared with primary repair in small bowel perforation and a decrease in the leak rate (13% to 4%). Small bowel perforation is the commonest form of perforation and the mortality rate associated with peritonitis remains unchanged.

Dark Solitons in FPU Lattice Chain

Science.gov (United States)

Wang, Deng-Long; Yang, Ru-Shu; Yang, You-Tian

2007-11-01

Based on multiple scales method, we study the nonlinear properties of a new Fermi-Pasta-Ulam lattice model analytically. It is found that the lattice chain exhibits a novel nonlinear elementary excitation, i.e. a dark soliton. Moreover, the modulation depth of dark soliton is increasing as the anharmonic parameter increases.

Dark Solitons in FPU Lattice Chain

International Nuclear Information System (INIS)

Wang Denglong; Yang Youtian; Yang Rushu

2007-01-01

Based on multiple scales method, we study the nonlinear properties of a new Fermi-Pasta-Ulam lattice model analytically. It is found that the lattice chain exhibits a novel nonlinear elementary excitation, i.e. a dark soliton. Moreover, the modulation depth of dark soliton is increasing as the anharmonic parameter increases.

Challenges and opportunities of health care supply chain management in the United States.

Science.gov (United States)

Elmuti, Dean; Khoury, Grace; Omran, Omar; Abou-Zaid, Ahmed S

2013-01-01

This article explores current supply chain management challenges and initiatives and identifies problems that affect supply chain management success in the U.S. health-care industry. In addition, it investigates the impact of health care supply chain management (SCM) initiatives on the overall organizational effectiveness. The attitudinal results, as well as the performance results presented in this study support the claim of health care proponents that the SCM allows organizations to reduce cost, improve quality, and reduce cycle time, and leads to high performance.

Solute transport in a single fracture involving an arbitrary length decay chain with rock matrix comprising different geological layers.

Science.gov (United States)

Mahmoudzadeh, Batoul; Liu, Longcheng; Moreno, Luis; Neretnieks, Ivars

2014-08-01

A model is developed to describe solute transport and retention in fractured rocks. It accounts for advection along the fracture, molecular diffusion from the fracture to the rock matrix composed of several geological layers, adsorption on the fracture surface, adsorption in the rock matrix layers and radioactive decay-chains. The analytical solution, obtained for the Laplace-transformed concentration at the outlet of the flowing channel, can conveniently be transformed back to the time domain by the use of the de Hoog algorithm. This allows one to readily include it into a fracture network model or a channel network model to predict nuclide transport through channels in heterogeneous fractured media consisting of an arbitrary number of rock units with piecewise constant properties. More importantly, the simulations made in this study recommend that it is necessary to account for decay-chains and also rock matrix comprising at least two different geological layers, if justified, in safety and performance assessment of the repositories for spent nuclear fuel. Copyright © 2014 Elsevier B.V. All rights reserved.

Lean in the supply chain : research and practice

OpenAIRE

Ugochukwu, Paschal

2012-01-01

Lean is a management philosophy that enhances customer value through waste elimination and continuous improvement in a system by applying lean principles, practices, and techniques. The focus on lean implementations and research had been typically a single company without extension to the entire supply chain. When the concept of lean is implemented across the entire supply chain, however, it is referred to as lean supply chain. The purpose of this thesis is to create a structure from theory a...

Slow magnetic relaxation in a cobalt magnetic chain.

Science.gov (United States)

Yang, Chen-I; Chuang, Po-Hsiang; Lu, Kuang-Lieh

2011-04-21

A homospin ladder-like chain, [Co(Hdhq)(OAc)](n) (1; H(2)dhq = 2,3-dihydroxyquinoxaline), shows a single-chain-magnet-like (SCM-like) behavior with the characteristics of frequency dependence of the out-of-phase component in alternating current (ac) magnetic susceptibilities and hysteresis loops. © The Royal Society of Chemistry 2011

UHF-RFID solutions for logistics units management in the food supply chain

Directory of Open Access Journals (Sweden)

Paolo Barge

2013-09-01

Full Text Available The availability of systems for automatic and simultaneous identification of several items belonging to a logistics unit during production, warehousing and delivering can improve supply chain management and speed traceability controls. Radio frequency identification (RFID is a powerful technique that potentially permits to reach this goal, but some aspects as, for instance, food product composition (e.g. moisture content, salt or sugar content and some peculiarities of the production environment (high moisture, high/low temperatures, metallic structures have prevented, so far, its application in food sector. In the food industry, composition and shape of items are much less regular than in other commodities sectors. In addition, a wide variety of packaging, composed by different materials, is employed. As material, size and shape of items to which the tag should be attached strongly influence the minimum power requested for tag functioning, performance improvements can be achieved only selecting suitable RF identifier for the specific combination of food product and packaging. When dealing with logistics units, the dynamic reading of a vast number of tags originates simultaneous broadcasting of signals (tag-to-tag collisions that could affect reading rates and the overall reliability of the identification procedure. This paper reports the results of an extensive analysis of the reading performance of UHF RFID systems for multiple dynamic electronic identification of food packed products in controlled conditions. Products were considered singularly or arranged on a logistics pallet. The effects on reading rate and reading zone of different factors, among which the type of product, the number and position of antennas, the field polarization, the reader RF power output, the interrogation protocol configuration as well as the transit speed, the number of tags and their interactions were analysed and compared.

78 FR 51802 - Culturally Significant Objects Imported for Exhibition Determinations: “Silla: Korea's Golden...

Science.gov (United States)

2013-08-21

... Golden Kingdom,'' imported from abroad for temporary exhibition within the United States, are of cultural... determine that the exhibition or display of the exhibit objects at The Metropolitan Museum of Art, New York...

Supply Chain Simulation using Business Process Modeling in Service Oriented Architecture

OpenAIRE

Taejong Yoo

2015-01-01

For supply chain optimization, as a key determinant of strategic resources mobility along the value-added chain, simulation is widely used to test the impact on supply chain performance for the strategic level decisions, such as the number of plants, the modes of transport, or the relocation of warehouses. Traditionally, a single centralized model that encompasses multiple participants in the supply chain is built when optimization of the supply chain through simulation is required. However, ...

Microphase Separation within a Comb Copolymer with Attractive Side Chains : A Computer Simulation Study

NARCIS (Netherlands)

Vasilevskaya, V.V.; Klochkov, A.A.; Khalatur, P.G.; Khokhlov, A.R.; Brinke, G. ten

2001-01-01

Computer simulation modelling of a flexible comb copolymer with attractive interactions between the monomer units of the side chains is performed. The conditions for the coil-globule transition, induced by the increase of attractive interaction, ε, between side chain monomer units, are analysed for

Supply chain oriented performance measurement for automotive spare parts

NARCIS (Netherlands)

de Leeuw, S.L.J.M.; Beekman, L.

2008-01-01

Literature provides a number of conceptual frameworks and discussions on performance measurement in supply chains. However, most of these frameworks focus on a single link of a supply chain. Furthermore, there is a lack of empirical analysis and case studies on performance metrics and measurements

Residue specific hydration of primary cell wall potato pectin identified by solid-state 13C single-pulse MAS and CP/MAS NMR spectroscopy

DEFF Research Database (Denmark)

Larsen, Flemming Hofmann; Chrestensen, Inge Byg; Damager, Iben

2011-01-01

Hydration of rhamnogalacturonan-I (RG-I) derived from potato cell wall was analyzed by 13C single-pulse (SP) magic-angle-spinning (MAS) and 13C cross-polarization (CP) MAS nuclear magnetic resonance (NMR) and supported by 2H SP/MAS NMR experiments. The study shows that the arabinan side chains...... hydrate more readily than the galactan side chains and suggests that the overall hydration properties can be controlled by modifying the ratio of these side chains. Enzymatic modification of native (NA) RG-I provided samples with reduced content of arabinan (sample DA), galactan (sample DG), or both side...... chains (sample DB). Results of these samples suggested that hydration properties were determined by the length and character of the side chains. NA and DA exhibited similar hydration characteristics, whereas DG and DB were difficult to hydrate because of the less hydrophilic properties of the rhamnose...

Nonlinear tearing mode and vortex chains

International Nuclear Information System (INIS)

Jovanovic, D.; Vranjes, J.

1996-01-01

We study the nonlinear stage of a tearing mode, whose island width exceeds the tearing layer thickness, and the wavelength is of the order of collisionless skin depth. A coherent solution is found in the form of a moving vortex chain. It is the result of a self-organization process, which adjusts the profile of the sheared poloidal magnetic field and excites a localized perpendicular sheared plasma flow, consisting of three counterstreaming jets. A numerical solution shows a twin chain of plasma vortices, coupled with a single chain of magnetic islands, whose width is of the order of collisionless skin depth. Adiabatic evolution of the vortex chain in the presence of small viscosity reveals its finite lifetime. The chain destruction may occur either directly, or through a sequence of bifurcations (corresponding to abrupt changes of the vortex chain parameters) to magnetic field stochastization within a layer of the collisionless skin depth scale, which occurs before the magnetic island overlapping takes place. This provides a new mechanism for the anomalous transport. (orig.)

HP-CsB{sub 5}O{sub 8}. Synthesis and characterization of an outstanding borate exhibiting the simultaneous linkage of all structural units of borates

Energy Technology Data Exchange (ETDEWEB)

Sohr, Gerhard; Huppertz, Hubert [Institut fuer Allgemeine, Anorganische und Theoretische Chemie, Leopold-Franzens-Universitaet Innsbruck (Austria); Toebbens, Daniel M. [Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Berlin (Germany); Schmedt auf der Guenne, Joern [Department fuer Chemie/Biologie, Universitaet Siegen (Germany)

2014-12-15

The new cesium pentaborate HP-CsB{sub 5}O{sub 8} is synthesized under high-pressure/high-temperature conditions of 6 GPa and 900 C in a Walker-type multianvil apparatus. The compound crystallizes in the orthorhombic space group Pnma (Z=4) with the parameters a=789.7(1), b=961.2(1), c=836.3(1) pm, V=0.6348(1) nm{sup 3}, R{sub 1}=0.0359 and wR{sub 2}=0.0440 (all data). The new structure type of HP-CsB{sub 5}O{sub 8} exhibits the simultaneous linkage of trigonal BO{sub 3} groups, corner-sharing BO{sub 4} tetrahedra, and edge-sharing BO{sub 4} tetrahedra including the presence of threefold-coordinated oxygen atoms. With respect to the rich structural chemistry of borates, HP-CsB{sub 5}O{sub 8} is the second structure type possessing this outstanding combination of the main structural units of borates in one compound. The structure consists of corrugated chains of corner- and edge-sharing BO{sub 4} tetrahedra interconnected through BO{sub 3} groups forming octagonal channels. Inside these channels, cesium is 13+3-fold coordinated by oxygen atoms. {sup 11}B MQMAS NMR spectra are analyzed to estimate the isotropic chemical shift values and quadrupolar parameters. IR and Raman spectra are obtained and compared to the calculated vibrational frequencies at the Γ-point. The high-temperature behavior is examined by means of temperature-programmed powder diffraction. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Anti-Human Endoglin (hCD105 Immunotoxin—Containing Recombinant Single Chain Ribosome-Inactivating Protein Musarmin 1

Directory of Open Access Journals (Sweden)

Begoña Barriuso

2016-06-01

Full Text Available Endoglin (CD105 is an accessory component of the TGF-β receptor complex, which is expressed in a number of tissues and over-expressed in the endothelial cells of tumor neovasculature. Targeting endoglin with immunotoxins containing type 2 ribosome-inactivating proteins has proved an effective tool to reduce blood supply to B16 mice tumor xenografts. We prepared anti-endoglin immunotoxin (IT—containing recombinant musarmin 1 (single chain ribosome-inactivating proteins linked to the mouse anti-human CD105 44G4 mouse monoclonal antibody via N-succinimidyl 3-(2-pyridyldithio propionate (SPDP. The immunotoxin specifically killed L929 fibroblast mouse cells transfected with the short form of human endoglin with IC50 values in the range of 5 × 10−10 to 10−9 M.

Single-magnon tunneling through a ferromagnetic nanochain

International Nuclear Information System (INIS)

Petrov, E.G.; Ostrovsky, V.

2010-01-01

Magnon transmission between ferromagnetic contacts coupled by a linear ferromagnetic chain is studied at the condition when the chain exhibits itself as a tunnel magnon transmitter. It is shown that dependently on magnon energy at the chain, a distant intercontact magnon transmission occurs either in resonant or off-resonant tunneling regime. In the first case, a transmission function depends weakly on the number of chain sites whereas at off-resonant regime the same function manifests an exponential drop with the chain length. Change of direction of external magnetic field in one of ferromagnetic contacts blocks a tunnel transmission of magnon.

Dynamics of Cancer Cell near Collagen Fiber Chain

Science.gov (United States)

Kim, Jihan; Sun, Bo

Cell migration is an integrated process that is important in life. Migration is essential for embryonic development as well as homeostatic processes such as wound healing and immune responses. When cell migrates through connective extracellular matrix (ECM), it applies cellular traction force to ECM and senses the rigidity of their local environment. We used human breast cancer cell (MDA-MB-231) which is highly invasive and applies strong traction force to ECM. As cancer cell applies traction force to type I collage-based ECM, it deforms collagen fibers near the surface. Patterns of deforming collagen fibers are significantly different with pairs of cancer cells compared to a single cancer cell. While a pair of cancer cells within 60 um creates aligned collagen fiber chains between them permanently, a single cancer cell does not form any fiber chains. In this experiment we measured a cellular response and an interaction between a pair of cells through the chain. Finally, we analyzed correlation of directions between cancer cell migration and the collagen chain alignment.

Bis(thienothiophenyl) diketopyrrolopyrrole-based conjugated polymers with various branched alkyl side chains and their applications in thin-film transistors and polymer solar cells.

Science.gov (United States)

Shin, Jicheol; Park, Gi Eun; Lee, Dae Hee; Um, Hyun Ah; Lee, Tae Wan; Cho, Min Ju; Choi, Dong Hoon

2015-02-11

New thienothiophene-flanked diketopyrrolopyrrole and thiophene-containing π-extended conjugated polymers with various branched alkyl side-chains were successfully synthesized. 2-Octyldodecyl, 2-decyltetradecyl, 2-tetradecylhexadecyl, 2-hexadecyloctadecyl, and 2-octadecyldocosyl groups were selected as the side-chain moieties and were anchored to the N-positions of the thienothiophene-flanked diketopyrrolopyrrole unit. All five polymers were found to be soluble owing to the bulkiness of the side chains. The thin-film transistor based on the 2-tetradecylhexadecyl-substituted polymer showed the highest hole mobility of 1.92 cm2 V(-1) s(-1) due to it having the smallest π-π stacking distance between the polymer chains, which was determined by grazing incidence X-ray diffraction. Bulk heterojunction polymer solar cells incorporating [6,6]-phenyl-C71-butyric acid methyl ester as the n-type molecule and the additive 1,8-diiodooctane (1 vol %) were also constructed from the synthesized polymers without thermal annealing; the device containing the 2-octyldodecyl-substituted polymer exhibited the highest power conversion efficiency of 5.8%. Although all the polymers showed similar physical properties, their device performance was clearly influenced by the sizes of the branched alkyl side-chain groups.

Electronic properties of linear carbon chains: Resolving the controversy

International Nuclear Information System (INIS)

Al-Backri, Amaal; Zólyomi, Viktor; Lambert, Colin J.

2014-01-01

Literature values for the energy gap of long one-dimensional carbon chains vary from as little as 0.2 eV to more than 4 eV. To resolve this discrepancy, we use the GW many-body approach to calculate the band gap E g of an infinite carbon chain. We also compute the energy dependence of the attenuation coefficient β governing the decay with chain length of the electrical conductance of long chains and compare this with recent experimental measurements of the single-molecule conductance of end-capped carbon chains. For long chains, we find E g = 2.16 eV and an upper bound for β of 0.21 Å −1

Wireless multi-channel single unit recording in freely moving and vocalizing primates.

Science.gov (United States)

Roy, Sabyasachi; Wang, Xiaoqin

2012-01-15

The ability to record well-isolated action potentials from individual neurons in naturally behaving animals is crucial for understanding neural mechanisms underlying natural behaviors. Traditional neurophysiology techniques, however, require the animal to be restrained which often restricts natural behavior. An example is the common marmoset (Callithrix jacchus), a highly vocal New World primate species, used in our laboratory to study the neural correlates of vocal production and sensory feedback. When restrained by traditional neurophysiological techniques marmoset vocal behavior is severely inhibited. Tethered recording systems, while proven effective in rodents pose limitations in arboreal animals such as the marmoset that typically roam in a three-dimensional environment. To overcome these obstacles, we have developed a wireless neural recording technique that is capable of collecting single-unit data from chronically implanted multi-electrodes in freely moving marmosets. A lightweight, low power and low noise wireless transmitter (headstage) is attached to a multi-electrode array placed in the premotor cortex of the marmoset. The wireless headstage is capable of transmitting 15 channels of neural data with signal-to-noise ratio (SNR) comparable to a tethered system. To minimize radio-frequency (RF) and electro-magnetic interference (EMI), the experiments were conducted within a custom designed RF/EMI and acoustically shielded chamber. The individual electrodes of the multi-electrode array were periodically advanced to densely sample the cortical layers. We recorded single-unit data over a period of several months from the frontal cortex of two marmosets. These recordings demonstrate the feasibility of using our wireless recording method to study single neuron activity in freely roaming primates. Copyright © 2011 Elsevier B.V. All rights reserved.

High Q-factor metasurfaces based on miniaturized asymmetric single split resonators

Science.gov (United States)

Al-Naib, Ibraheem A. I.; Jansen, Christian; Koch, Martin

2009-04-01

We introduce asymmetric single split rectangular resonators as bandstop metasurfaces, which exhibit very high Q-factors in combination with low passband losses and a small electrical footprint. The effect of the degree of asymmetry on the frequency response is thoroughly studied. Furthermore, complementary structures, which feature a bandpass behavior, were derived by applying Babinet's principle and investigated with regards to their transmission characteristics. In future, asymmetric single split rectangular resonators could provide efficient unit cells for frequency selective surface devices, such as thin-film sensors or high performance filters.

Single-chain-in-mean-field simulations of weak polyelectrolyte brushes

Science.gov (United States)

Léonforte, F.; Welling, U.; Müller, M.

2016-12-01

Structural properties of brushes which are composed of weak acidic and basic polyelectrolytes are studied in the framework of a particle-based approach that implicitly accounts for the solvent quality. Using a semi-grandcanonical partition function in the framework of the Single-Chain-in-Mean-Field (SCMF) algorithm, the weak polyelectrolyte is conceived as a supramolecular mixture of polymers in different dissociation states, which are explicitly treated in the partition function and sampled by the SCMF procedure. One obtains a local expression for the equilibrium acid-base reaction responsible for the regulation of the charged groups that is also incorporated to the SCMF sampling. Coupled to a simultaneous treatment of the electrostatics, the approach is shown to capture the main features of weak polyelectrolyte brushes as a function of the bulk pH in the solution, the salt concentration, and the grafting density. Results are compared to experimental and theoretical works from the literature using coarse-grained representations of poly(acrylic acid) (PAA) and poly(2-vinyl pyridine) (P2VP) polymer-based brushes. As the Born self-energy of ions can be straightforwardly included in the numerical approach, we also study its effect on the local charge regulation mechanism of the brush. We find that its effect becomes significant when the brush is dense and exposed to high salt concentrations. The numerical methodology is then applied (1) to the study of the kinetics of collapse/swelling of a P2VP brush and (2) to the ability of an applied voltage to induce collapse/swelling of a PAA brush in a pH range close to the pKa value of the polymer.

Single and multi-band electromagnetic induced transparency-like metamaterials with coupled split ring resonators

Science.gov (United States)

Bagci, Fulya; Akaoglu, Baris

2017-08-01

We present a metamaterial configuration exhibiting single and multi-band electromagnetic induced transparency (EIT)-like properties. The unit cell of the single band EIT-like metamaterial consists of a multi-split ring resonator surrounded by a split ring resonator. The multi-split ring resonator acts as a quasi-dark or dark resonator, depending on the polarization of the incident wave, and the split ring resonator serves as the bright resonator. Combination of these two resonators results in a single band EIT-like transmission inside the stop band. EIT-like transmission phenomenon is also clearly observed in the measured transmission spectrum at almost the same frequencies for vertical and horizontal polarized waves, and the numerical results are verified for normal incidence. Moreover, multi-band transmission windows are created within a wide band by combining the two slightly different single band EIT-like metamaterial unit cells that exhibit two different coupling strengths inside a supercell configuration. Group indices as high as 123 for single band and 488 for tri-band transmission, accompanying with high transmission rates (over 80%), are achieved, rendering the metamaterial very suitable for multi-band slow light applications. It is shown that the group delay of the propagating wave can be increased and dynamically controlled by changing the polarization angle. Multi-band EIT-like transmission is also verified experimentally, and a good agreement with simulations is obtained. The proposed novel methodology for obtaining multi-band EIT, which takes advantage of a supercell configuration by hosting slightly different configured unit cells, can be utilized for easily formation and manipulation of multi-band transmission windows inside a stop band.

2009 Defense Supply Center Columbus Land and Maritime Supply Chains Business Conference and Exhibition

Science.gov (United States)

2009-08-19

DSN: 388-7453 CSCASSIG@CSD.DISA.MIL  DFAS eCommerce web site http://www.dfas.mil/contractorpay/electroniccommerce.html  DFAS Customer Service...M-ATV is a separate category within the MRAP family of vehicles. ►Mission: Small-unit combat operations in highly restricted rural , mountainous...vehicles. ►Mission: Small-unit combat operations in highly restricted rural , mountainous and urban environments. ► Troop Transport: Carry up to five

2009 Defense Supply Center Columbus Land and Maritime Supply Chains: Business Conference and Exhibition

Science.gov (United States)

2009-08-19

DSN: 388-7453 CSCASSIG@CSD.DISA.MIL  DFAS eCommerce web site http://www.dfas.mil/contractorpay/electroniccommerce.html  DFAS Customer Service...M-ATV is a separate category within the MRAP family of vehicles. ►Mission: Small-unit combat operations in highly restricted rural , mountainous...vehicles. ►Mission: Small-unit combat operations in highly restricted rural , mountainous and urban environments. ► Troop Transport: Carry up to five

The innovation value chain.

Science.gov (United States)

Hansen, Morten T; Birkinshaw, Julian

2007-06-01

The challenges of coming up with fresh ideas and realizing profits from them are different for every company. One firm may excel at finding good ideas but may have weak systems for bringing them to market. Another organization may have a terrific process for funding and rolling out new products and services but a shortage of concepts to develop. In this article, Hansen and Birkinshaw caution executives against using the latest and greatest innovation approaches and tools without understanding the unique deficiencies in their companies' innovation systems. They offer a framework for evaluating innovation performance: the innovation value chain. It comprises the three main phases of innovation (idea generation, conversion, and diffusion) as well as the critical activities performed during those phases (looking for ideas inside your unit; looking for them in other units; looking for them externally; selecting ideas; funding them; and promoting and spreading ideas companywide). Using this framework, managers get an end-to-end view of their innovation efforts. They can pinpoint their weakest links and tailor innovation best practices appropriately to strengthen those links. Companies typically succumb to one of three broad "weakest-link" scenarios. They are idea poor, conversion poor, or diffusion poor. The article looks at the ways smart companies - including Intuit, P&G, Sara Lee, Shell, and Siemens- modify the best innovation practices and apply them to address those organizations' individual needs and flaws. The authors warn that adopting the chain-based view of innovation requires new measures of what can be delivered by each link in the chain. The approach also entails new roles for employees "external scouts" and "internal evangelists," for example. Indeed, in their search for new hires, companies should seek out those candidates who can help address particular weaknesses in the innovation value chain.

Chronic neural probe for simultaneous recording of single-unit, multi-unit, and local field potential activity from multiple brain sites

Science.gov (United States)

Pothof, F.; Bonini, L.; Lanzilotto, M.; Livi, A.; Fogassi, L.; Orban, G. A.; Paul, O.; Ruther, P.

2016-08-01

Objective. Drug resistant focal epilepsy can be treated by resecting the epileptic focus requiring a precise focus localisation using stereoelectroencephalography (SEEG) probes. As commercial SEEG probes offer only a limited spatial resolution, probes of higher channel count and design freedom enabling the incorporation of macro and microelectrodes would help increasing spatial resolution and thus open new perspectives for investigating mechanisms underlying focal epilepsy and its treatment. This work describes a new fabrication process for SEEG probes with materials and dimensions similar to clinical probes enabling recording single neuron activity at high spatial resolution. Approach. Polyimide is used as a biocompatible flexible substrate into which platinum electrodes and leads are integrated with a minimal feature size of 5 μm. The polyimide foils are rolled into the cylindrical probe shape at a diameter of 0.8 mm. The resulting probe features match those of clinically approved devices. Tests in saline solution confirmed the probe stability and functionality. Probes were implanted into the brain of one monkey (Macaca mulatta), trained to perform different motor tasks. Suitable configurations including up to 128 electrode sites allow the recording of task-related neuronal signals. Main results. Probes with 32 and 64 electrode sites were implanted in the posterior parietal cortex. Local field potentials and multi-unit activity were recorded as early as one hour after implantation. Stable single-unit activity was achieved for up to 26 days after implantation of a 64-channel probe. All recorded signals showed modulation during task execution. Significance. With the novel probes it is possible to record stable biologically relevant data over a time span exceeding the usual time needed for epileptic focus localisation in human patients. This is the first time that single units are recorded along cylindrical polyimide probes chronically implanted 22 mm deep into the

Trapping a Knot into Tight Conformations by Intra-Chain Repulsions

Directory of Open Access Journals (Sweden)

Liang Dai

2017-02-01

Full Text Available Knots can occur in biopolymers such as DNA and peptides. In our previous study, we systematically investigated the effects of intra-chain interactions on knots and found that long-range repulsions can surprisingly tighten knots. Here, we use this knowledge to trap a knot into tight conformations in Langevin dynamics simulations. By trapping, we mean that the free energy landscape with respect to the knot size exhibits a potential well around a small knot size in the presence of long-range repulsions, and this potential can well lead to long-lived tight knots when its depth is comparable to or larger than thermal energy. We tune the strength of intra-chain repulsion such that a knot is weakly trapped. Driven by thermal fluctuations, the knot can escape from the trap and is then re-trapped. We find that the knot switches between tight and loose conformations—referred to as “knot breathing”. We use a Yukawa potential to model screened electrostatic interactions to explore the relevance of knot trapping and breathing in charged biopolymers. We determine the minimal screened length and the minimal strength of repulsion for knot trapping. We find that Coulomb-induced knot trapping is possible to occur in single-stranded DNA and peptides for normal ionic strengths.

77 FR 51606 - Culturally Significant Objects Imported for Exhibition Determinations: “Extravagant Inventions...

Science.gov (United States)

2012-08-24

... temporary exhibition within the United States, are of cultural significance. The additional objects are... exhibition or display of the additional exhibit objects at The Metropolitan Museum of Art, New York, NY, from... at The Metropolitan Museum of Art, three of the works will continue to be displayed at The...

78 FR 32000 - Culturally Significant Objects Imported for Exhibition Determinations: “Before and After the...

Science.gov (United States)

2013-05-28

... Lakes,'' imported from abroad for temporary exhibition within the United States, are of cultural... also determine that the exhibition or display of the exhibit objects at the National Museum of the...

An exceptional series of phase transitions in hydrophobic amino acids with linear side chains

Directory of Open Access Journals (Sweden)

Carl Henrik Görbitz

2016-09-01

Full Text Available The solid-state phase transitions and intermediate structures of S-2-aminobutanoic acid (l-2-aminobutyric acid, S-2-aminopentanoic acid (l-norvaline, S-2-aminohexanoic acid (l-norleucine and l-methionine between 100 and 470 K, identified by differential scanning calorimetry, have been characterized in a comprehensive single-crystal X-ray diffraction investigation. Unlike other enantiomeric amino acids investigated until now, this group featuring linear side chains displays up to five distinct phases. The multiple transitions between them involve a number of different processes: alteration of the hydrogen-bond pattern, to our knowledge the first example of this observed for an amino acid, sliding of molecular bilayers, seen previously only for racemates and quasiracemates, concerted side-chain rearrangements and abrupt as well as gradual modifications of the side-chain disorder. Ordering of l-norleucine upon cooling even proceeds via an incommensurately modulated structure. l-Methionine has previously been described as being fully ordered at room temperature. An accurate refinement now reveals extensive disorder for both molecules in the asymmetric unit, while two previously unknown phases occur above room temperature.

Response of cat cerebellar vermis induced by sound. I. Influence of drugs on responses of single units.

Science.gov (United States)

Jastreboff, P J; Tarnecki, R

1975-01-01

Experiments were done on the cats under Chloralose and/or Nembutal anesthesia. A click was used as a standard acoustic stimulus. The type of responses of single units from cerebellar vermis lobuli V-VII were analyzed. At least four different types of single unit reactions were observed and one of these - oscillatory - was produced by the presence of Flaxedil simultaneously with Chloralose. The system that controls the activity of the middle-ear-muscles can be suspected as the source of the oscillatory pattern of the cerebellar response. Latencies were found to be constant, independent of anesthesia, but it was necessary to have a low level of Nembutal anesthesia because of the overriding inhibitory influence of Nembutal.

Revenue-Sharing Contract Models for Logistics Service Supply Chains with Mass Customization Service

Directory of Open Access Journals (Sweden)

Weihua Liu

2015-01-01

Full Text Available The revenue-sharing contract is one of the most important supply chain coordination contracts; it has been applied in various supply chains. However, studies related to service supply chains with mass customization (MC are lacking. Considering the equity of benefit distribution between the members of service supply chains, in this paper, we designed two revenue-sharing contracts. The first contract for the maximum equity of a single logistics service integrator (LSI and single functional logistics service provider (FLSP in a two-echelon logistics service supply chain was designed by introducing the fair entropy function (“one to one” model. Furthermore, the method is extended to a more complex supply chain, which consists of a single LSI and multiple FLSPs. A new contract was designed not only for considering the equity of an LSI and each FLSP but also for the equity between each FLSP (“one to N” model. The “one to one” model in three-echelon LSSC is also provided. The result exemplifies that, whether in the “one to one” model or “one to N” model, there exists a best interval of customized level when the revenue-sharing coefficient reaches its maximum.

Enabling high-mobility, ambipolar charge-transport in a DPP-benzotriazole copolymer by side-chain engineering

DEFF Research Database (Denmark)

Gruber, Mathias; Jung, Seok-Heon; Schott, Sam

2015-01-01

In this article we discuss the synthesis of four new low band-gap co-polymers based on the diketopyrrolopyrrole (DPP) and benzotriazole (BTZ) monomer unit. We demonstrate that the BTZ unit allows for additional solubilizing side-chains on the co-monomer and show that the introduction of a linear...... side-chain on the DPP-unit leads to an increase in thin-film order and charge-carrier mobility if a sufficiently solubilizing, branched, side chain is attached to the BTZ. We compare two different synthetic routes, direct arylation and Suzuki-polycondensation, by a direct comparison of polymers...

77 FR 20476 - Culturally Significant Objects Imported for Exhibition Determinations: “Nicolai Fechin”

Science.gov (United States)

2012-04-04

...,'' imported from abroad for temporary exhibition within the United States, are of cultural significance. The... that the exhibition or display of the exhibit objects at the Museum of Russian Art, Minneapolis, Minnesota, from on or about August 18, 2012, until on or about January 13, 2013, the Frye Art Museum...

75 FR 1009 - Culturally Significant Objects Imported for Exhibition Determinations: “Habsburg Treasures”

Science.gov (United States)

2010-01-07

... ``Habsburg Treasures,'' imported from abroad for temporary exhibition within the United States, are of... custodian. I also determine that the exhibition or display of the exhibit objects at the Norton Museum of...; the Columbia Museum of Art, Columbia, South Carolina, from on or about May 21, 2010, until on or about...

Supply chain optimization by implementation of modern ICT

Directory of Open Access Journals (Sweden)

Soldat Drago S.

2014-01-01

Full Text Available This paper deals with most important techniques used for supply chain management including the latest applications and program tools intended for companies that do business in transport and logistics. The main goal of these technologies is management coherent data and exchange of information between companies and business units within the supply chain. The expansion of modern e-logistics applications transfers from private networks to Internet has been noticed in recent few years. Market globalization and e-business implementation have positioned portal as key element gathering employers, employees, business partners and end users P/S - main participants in every supply chain - by mutual interface. Thus, portals are often called mega portals of -supply chains.

The Evaluation of Simulation Games Applicablity for Better Understanding Supply Chain Principles

OpenAIRE

Blaženka Kneževiæ

2008-01-01

In order to achieve competitive advantage, each company has to determine its strategic position in relation to its suppliers and buyers, and to realize how behavior of supply chain participants influence on overall supply chain functionality. Supply chains with high level of synchronization of activities from producer to consumer, at a long-time run, will achieve high business result for single participant, and for entire chain. Supply chain synchronization is complex and expensive process. T...

Conducting single-molecule magnet materials.

Science.gov (United States)

Cosquer, Goulven; Shen, Yongbing; Almeida, Manuel; Yamashita, Masahiro

2018-05-11

Multifunctional molecular materials exhibiting electrical conductivity and single-molecule magnet (SMM) behaviour are particularly attractive for electronic devices and related applications owing to the interaction between electronic conduction and magnetization of unimolecular units. The preparation of such materials remains a challenge that has been pursued by a bi-component approach of combination of SMM cationic (or anionic) units with conducting networks made of partially oxidized (or reduced) donor (or acceptor) molecules. The present status of the research concerning the preparation of molecular materials exhibiting SMM behaviour and electrical conductivity is reviewed, describing the few molecular compounds where both SMM properties and electrical conductivity have been observed. The evolution of this research field through the years is discussed. The first reported compounds are semiconductors in spite being able to present relatively high electrical conductivity, and the SMM behaviour is observed at low temperatures where the electrical conductivity of the materials is similar to that of an insulator. During the recent years, a breakthrough has been achieved with the coexistence of high electrical conductivity and SMM behaviour in a molecular compound at the same temperature range, but so far without evidence of a synergy between these properties. The combination of high electrical conductivity with SMM behaviour requires not only SMM units but also the regular and as far as possible uniform packing of partially oxidized molecules, which are able to provide a conducting network.

A performance measurement framework for the South African bulk export wine supply chain

OpenAIRE

Johan B. Smit; Joubert van Eeden; Frances E. van Dyk

2017-01-01

Background: Many participants in the South African wine industry still exhibit low supply chain maturity in the management of their supply chains. This hampers export performance and ultimately client satisfaction. The development and tracking of appropriate metrics are key steps in improving supply chain performance. Objectives: The purpose of this study was to develop a performance measurement framework for the South African wine industry, focussing on the bulk export segment. Metho...

Developing a Comprehensive Approach Could Help DOD Better Manage National Security Risks in the Supply Chain

Science.gov (United States)

2016-02-01

supply chains for rare earths.20 According to Industrial Analysis Center officials, only 10 percent of surveys sent to prime contractors for 79...the Supply Chain Report to Congressional Committees February 2016 GAO-16-161 United States Government Accountability Office United...Developing a Comprehensive Approach Could Help DOD Better Manage National Security Risks in the Supply Chain Why GAO Did This Study DOD depends on

Early stage of deformation in tungsten, tantalum, and nickel single crystals

International Nuclear Information System (INIS)

Pinatti, D.G.

1977-01-01

High purity Tantalum, Tungsten and Nickel single crystals were tested in simple tension between 77 and 300 K. The Ta and W was oriented for maximum resolved shear stress on the [111] (101) system. Simultaneously microstrain and ultrasonic propagation measurements (attenuation and modulus defect) were performed at various stress bias in order to test details of theories concerning the preyield region and the flow stress in body-centered cubic refractory metals. The experimental retical predictions for the kink chain model over the string model for dislocation. It appears that double kink nucleation in non-screw dislocations has negligible effect in this domains. The results for annealed Ta exhibited no stress bias effect on the ultrasonic propagation measurements, which suggest that the strong influence of impurities mask our ability to discern this fine structure for dislocation motion. For prestrained W and Ta, it was found that double-kink nucleation on nonscrew dislocation plays an important role and revealed interesting results with respect to our understanding of the intrinsic dislocation structure in bcc metals. These results support the kink chain model for dislocation unambiguously. The experiments on the prestrained samples also exhibited experimental results which are qualitatively but not quantitatively in agreement with the theoretical predictions of Seeger and Sectak. The Ni single crystals were prestrained between 10 and 23 percent in stage II, and the microstrain damping loops have been studied as a function of stress amplitude, temperature and magnetic field. The predominant hysteretic contribution to the observed decrement was analyzed according to the model of Roberts (Al. 14, Al. 15), and good agreement between theory and experiment was found

Reliability modelling for wear out failure period of a single unit system

OpenAIRE

Arekar, Kirti; Ailawadi, Satish; Jain, Rinku

2012-01-01

The present paper deals with two time-shifted density models for wear out failure period of a single unit system. The study, considered the time-shifted Gamma and Normal distributions. Wear out failures occur as a result of deterioration processes or mechanical wear and its probability of occurrence increases with time. A failure rate as a function of time deceases in an early failure period and it increases in wear out period. Failure rates for time shifted distributions and expression for m...

76 FR 44977 - Culturally Significant Objects Imported for Exhibition Determinations: “De Kooning: A Retrospective”

Science.gov (United States)

2011-07-27

... determine that the exhibition or display of the exhibit objects at The Museum of Modern Art in New York, New... Retrospective,'' imported from abroad for temporary exhibition within the United States, are of cultural...

77 FR 75489 - Culturally Significant Objects Imported for Exhibition Determinations: “Projects 99: Meiro Koizumi”

Science.gov (United States)

2012-12-20

... also determine that the exhibition or display of the exhibit objects at The Museum of Modern Art in New...: Meiro Koizumi,'' imported from abroad for temporary exhibition within the United States, are of cultural...

77 FR 4614 - Culturally Significant Objects Imported for Exhibition Determinations: “Children of the Plumed...

Science.gov (United States)

2012-01-30

... Ancient Mexico,'' imported from abroad for temporary exhibition within the United States, are of cultural... also determine that the exhibition or display of the exhibit objects at the Los Angeles County Museum... exhibition or display of the exhibit at the Dallas Museum of Art, Dallas, TX from on or about July 29, 2012...

Elastin-like Polypeptide Linkers for Single-Molecule Force Spectroscopy.

Science.gov (United States)

Ott, Wolfgang; Jobst, Markus A; Bauer, Magnus S; Durner, Ellis; Milles, Lukas F; Nash, Michael A; Gaub, Hermann E

2017-06-27

Single-molecule force spectroscopy (SMFS) is by now well established as a standard technique in biophysics and mechanobiology. In recent years, the technique has benefitted greatly from new approaches to bioconjugation of proteins to surfaces. Indeed, optimized immobilization strategies for biomolecules and refined purification schemes are being steadily adapted and improved, which in turn has enhanced data quality. In many previously reported SMFS studies, poly(ethylene glycol) (PEG) was used to anchor molecules of interest to surfaces and/or cantilever tips. The limitation, however, is that PEG exhibits a well-known trans-trans-gauche to all-trans transition, which results in marked deviation from standard polymer elasticity models such as the worm-like chain, particularly at elevated forces. As a result, the assignment of unfolding events to protein domains based on their corresponding amino acid chain lengths is significantly obscured. Here, we provide a solution to this problem by implementing unstructured elastin-like polypeptides as linkers to replace PEG. We investigate the suitability of tailored elastin-like polypeptides linkers and perform direct comparisons to PEG, focusing on attributes that are critical for single-molecule force experiments such as linker length, monodispersity, and bioorthogonal conjugation tags. Our results demonstrate that by avoiding the ambiguous elastic response of mixed PEG/peptide systems and instead building the molecular mechanical systems with only a single bond type with uniform elastic properties, we improve data quality and facilitate data analysis and interpretation in force spectroscopy experiments. The use of all-peptide linkers allows alternative approaches for precisely defining elastic properties of proteins linked to surfaces.

Market orientation seen in a value chain perspective

DEFF Research Database (Denmark)

Sonne, Anne-Mette; Stacey, Julia; Grunert, Klaus G.

2002-01-01

Market orientation is regarded as a prerequisite for a company's ability to create customer value and higher profits. Market orientation is usually regarded as something, which characterises a company. However, companies are part of value chains, and a lot of competition taking place...... in international markets is between the different value chains rather than between the individual companies. This is the reason why it makes more sense to look at the degree of market orientation in a complete value chain rather than the degree of market orientation of a single company....

On the Wrapping of Polyglycolide, Poly(Ethylene Oxide), and Polyketone Polymer Chains Around Single-Walled Carbon Nanotubes Using Molecular Dynamics Simulations

Science.gov (United States)

Rouhi, S.; Alizadeh, Y.; Ansari, R.

2015-02-01

By using molecular dynamics simulations, the interaction between a single-walled carbon nanotube and three different polymers has been studied in this work. The effects of various parameters such as the nanotube geometry and temperature on the interaction energy and radius of gyration of polymers have been explored. By studying the snapshots of polymers along the single-walled carbon nanotube, it has been shown that 50 ps can be considered as a suitable time after which the shape of polymer chains around the nanotube remains almost unchanged. It is revealed that the effect of temperature on the interaction energy and radius of gyration of polymers in the range of 250 to 500 K is not significant Also, it is shown that the interaction energy depends on the nanotube diameter.

Linear-after-the-exponential polymerase chain reaction and allied technologies. Real-time detection strategies for rapid, reliable diagnosis from single cells.

Science.gov (United States)

Pierce, Kenneth E; Wangh, Lawrence J

2007-01-01

Accurate detection of gene sequences in single cells is the ultimate challenge to polymerase chain reaction (PCR) sensitivity. Unfortunately, commonly used conventional and real-time PCR techniques are often too unreliable at that level to provide the accuracy needed for clinical diagnosis. Here we provide details of linear-after-the-exponential-PCR (LATE-PCR), a method similar to asymmetric PCR in the use of primers at different concentrations, but with novel design criteria to ensure high efficiency and specificity. Compared with conventional PCR, LATE-PCR increases the signal strength and allele discrimination capability of oligonucleotide probes such as molecular beacons and reduces variability among replicate samples. The analysis of real-time kinetics of LATE-PCR signals provides a means for improving the accuracy of single cell genetic diagnosis.

Research on the Governance Mechanism of Aviation Complex Product Manufacturing Supply Chain Based on Dynamic Game Theory

Directory of Open Access Journals (Sweden)

Wang Nan

2016-01-01

Full Text Available In the manufacturing process of aeronautical complex products, for the following problems: develop long production cycle, a large number of ancillary products, a plurality of participating units, etc, and the status of the frequency of quality problems, using single-phase static game model in the case of asymmetric information, study on Supplier Quality insufficient investment, which resulting in opportunistic behaviour reasons. And using KMRW dynamic game model, we quantitative analysis the mechanism and crucial role of reputation mechanisms to ensure aeronautical complex product manufacturing supply chain and effective operation.

Stability of llama heavy chain antibody fragments under extreme conditions

NARCIS (Netherlands)

Dolk, E.

2004-01-01

Camelids have next to their normal antibodies, a unique subset of antibodies lacking light chains. The resulting single binding domain, VHH, of these heavy chain antibodies consequently have unique properties. A high stability is one of these properties, which was investigated in this thesis. The

Facile analysis of contents and compositions of the chondroitin sulfate/dermatan sulfate hybrid chain in shark and ray tissues.

Science.gov (United States)

Takeda, Naoko; Horai, Sawako; Tamura, Jun-ichi

2016-04-07

The chondroitin sulfate (CS)/dermatan sulfate (DS) hybrid chain was extracted from specific tissues of several kinds of sharks and rays. The contents and sulfation patterns of the CS/DS hybrid chain were precisely analyzed by digestion with chondroitinases ABC and AC. All samples predominantly contained the A- and C-units. Furthermore, all samples characteristically contained the D-unit. Species-specific differences were observed in the contents of the CS/DS hybrid chain, which were the highest in Mako and Blue sharks and Sharpspine skates, but were lower in Hammerhead sharks. Marked differences were observed in the ratio of the C-unit/A-unit between sharks and rays. The contents of the CS/DS hybrid chain and the ratio of the C-unit/A-unit may be related to an oxidative stress-decreasing ability. Copyright © 2016 Elsevier Ltd. All rights reserved.

Decentralized method for load sharing and power management in a hybrid single/three-phase islanded microgrid consisting of hybrid source PV/battery units

DEFF Research Database (Denmark)

Karimi, Yaser; Guerrero, Josep M.; Oraee, Hashem

2016-01-01

This paper proposes a new decentralized power management and load sharing method for a photovoltaic based, hybrid single/three-phase islanded microgrid consisting of various PV units, battery units and hybrid PV/battery units. The proposed method takes into account the available PV power...... and battery conditions of the units to share the load among them and power flow among different phases is performed automatically through three-phase units. Modified active power-frequency droop functions are used according to operating states of each unit and the frequency level is used as trigger...... for switching between the states. Efficacy of the proposed method in different load, PV generation and battery conditions is validated experimentally in a microgrid lab prototype consisted of one three-phase unit and two single-phase units....

A Novel Algorithm for the Generation of Distinct Kinematic Chain

Science.gov (United States)

Medapati, Sreenivasa Reddy; Kuchibhotla, Mallikarjuna Rao; Annambhotla, Balaji Srinivasa Rao

2016-07-01

Generation of distinct kinematic chains is an important topic in the design of mechanisms for various industrial applications i.e., robotic manipulator, tractor, crane etc. Many researchers have intently focused on this area and explained various processes of generating distinct kinematic chains which are laborious and complex. It is desirable to enumerate the kinematic chains systematically to know the inherent characteristics of a chain related to its structure so that all the distinct chains can be analyzed in depth, prior to the selection of a chain for a purpose. This paper proposes a novel and simple method with set of rules defined to eliminate isomorphic kinematic chains generating distinct kinematic chains. Also, this method simplifies the process of generating distinct kinematic chains even at higher levels i.e., 10-link, 11-link with single and multiple degree of freedom.

Production and postharvest quality maintenance of single unit and bunching broccoli in Virginia

OpenAIRE

Jett, Lewis W.

1990-01-01

Broccoli (Brassica oleracea L. var. italica) has become an increasingly popular vegetable with American consumers. Much of the attractiveness of fresh broccoli is derived from this vegetable's high nutrition and excellent organoleptic properties. In a consumer response survey, Virginia Master Gardeners indicated a preference for broccoli that has less stalk and more florets by weight. The objectives of this research were to produce single unit broccoli, and to examine vac...

Multiple impacts in dissipative granular chains

CERN Document Server

Nguyen, Ngoc Son

2014-01-01

The extension of collision models for single impacts between two bodies, to the case of multiple impacts (which take place when several collisions occur at the same time in a multibody system) is a challenge in Solid Mechanics, due to the complexity of such phenomena, even in the frictionless case. This monograph aims at presenting the main multiple collision rules proposed in the literature. Such collisions typically occur in granular materials, the simplest of which are made of chains of aligned balls. These chains are used throughout the book to analyze various multiple impact rules which extend the classical Newton (kinematic restitution), Poisson (kinetic restitution) and Darboux-Keller (energetic or kinetic restitution) approaches for impact modelling. The shock dynamics in various types of chains of aligned balls (monodisperse, tapered, decorated, stepped chains) is carefully studied and shown to depend on several parameters: restitution coefficients, contact stiffness ratios, elasticity coefficients (...

Transverse transport in coupled strongly correlated electronic chains

International Nuclear Information System (INIS)

Capponi, S.; Poilblanc, D.

1997-01-01

One-particle interchain hopping in a system of coupled Luttinger liquids is investigated by use of exact diagonalizations techniques. We give numerical evidence that inter-chain coherent hopping (defined by a non-vanishing splitting) can be totally suppressed for the Luttinger liquid exponent α ∝ 0.4 or even smaller α values. The transverse conductivity is shown to exhibit a strong incoherent part even when coherent inter-chain hopping is believed to occur. Implications for the optical experiments in quasi-1D organic or high-T c superconductors is outlined. (orig.)

Traveling Exhibitions as Sites for Informal Learning: Assessing Different Strategies with Field Trips to Traveling Exhibitions at Non-Museum Sites

Science.gov (United States)

Harker, Richard J. W.; Badger, James

2015-01-01

This study investigated the use of different pedagogical techniques to create an intellectually engaging experience for middle school students who visited a traveling exhibition from the United States Holocaust Memorial Museum at a non-museum host site: the University of North Georgia Dahlonega's Library and Technology Center. The findings of this…

Sustainability of Global and Local Food Value Chains: An Empirical Comparison of Peruvian and Belgian Asparagus

Directory of Open Access Journals (Sweden)

Jana Schwarz

2016-04-01

Full Text Available The sustainability of food value chains is an increasing concern for consumers, food companies and policy-makers. Global food chains are often perceived to be less sustainable than local food chains. Yet, thorough food chain analyses and comparisons of different food chains across sustainability dimensions are rare. In this article we analyze the local Belgian and global Peruvian asparagus value chains and explore their sustainability performance. A range of indicators linked to environmental, economic and social impacts is calculated to analyze the contribution of the supply chains to economic development, resource use, labor relations, distribution of added value and governance issues. Our findings suggest that none of the two supply chains performs invariably better and that there are trade-offs among and between sustainability dimensions. Whereas the global chain uses water and other inputs more intensively and generates more employment per unit of land and higher yields, the local chain generates more revenue per unit of land.

Global Carbon Fiber Composites Supply Chain Competitiveness Analysis

Energy Technology Data Exchange (ETDEWEB)

Das, Sujit [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Warren, Josh [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); West, Devin [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Schexnayder, Susan M. [Univ. of Tennessee, Knoxville, TN (United States)

2016-05-01

This study identifies key opportunities in the carbon fiber supply chain where the United States Department of Energy's Office of Energy Efficiency and Renewable Energy resources and investments can help the United States achieve or maintain a competitive advantage. The report focuses on four application areas--wind energy, aerospace, automotive, and pressure vessels--that top the list of industries using carbon fiber and carbon fiber reinforced polymers and are also particularly relevant to EERE's mission. For each of the four application areas, the report addresses the supply and demand trends within that sector, supply chain, and costs of carbon fiber and components, all contributing to a competitiveness assessment that addresses the United States' role in future industry growth. This report was prepared by researchers at Oak Ridge National Laboratory and the University of Tennessee for the Clean Energy Manufacturing Analysis Center.

Newton's Cradle and Entanglement Transport in a Flexible Rydberg Chain

International Nuclear Information System (INIS)

Wuester, S.; Ates, C.; Eisfeld, A.; Rost, J. M.

2010-01-01

In a regular, flexible chain of Rydberg atoms, a single electronic excitation localizes on two atoms that are in closer mutual proximity than all others. We show how the interplay between excitonic and atomic motion causes electronic excitation and diatomic proximity to propagate through the Rydberg chain as a combined pulse. In this manner entanglement is transferred adiabatically along the chain, reminiscent of momentum transfer in Newton's cradle.

76 FR 77582 - Culturally Significant Objects Imported for Exhibition Determinations: “Cindy Sherman”

Science.gov (United States)

2011-12-13

...,'' imported from abroad for temporary exhibition within the United States, are of cultural significance. The... that the exhibition or display of the exhibit objects at the Museum of Modern Art, New York, New York, from on or about February 26, 2012, until on or about June 11, 2012, the San Francisco Museum of Modern...

A family of mixed-metal cyanide cubes with alternating octahedral and tetrahedral corners exhibiting a variety of magnetic behaviors including single molecule magnetism.

Science.gov (United States)

Schelter, Eric J; Karadas, Ferdi; Avendano, Carolina; Prosvirin, Andrey V; Wernsdorfer, Wolfgang; Dunbar, Kim R

2007-07-04

A series of structurally related pseudocubic metal cyanide clusters of Re(II) and 3d metal ions [{MX}4{Re(triphos)(CN)3}4] (M = Mn, Fe, Co, Ni, Zn; X = Cl, I, -OCH3) have been prepared, and their magnetic and electrochemical properties have been probed to evaluate the effect of changing the identity of the 3d metal ion. Electrochemistry of the clusters reveals several rhenium-based oxidation and reduction processes, some of which result in cluster fragmentation. The richest electrochemistry was observed for the iron congener, which exists as the Re(I)/Fe(III) cluster at the resting potential and exhibits six clear one-electron reversible redox couples and two, closely spaced one-electron quasi-reversible processes. The [{MnIICl}4{ReII(triphos)(CN)3}4] complex exhibits single molecule magnetism with a fast tunneling relaxation process observed at H = 0 determined by micro-SQUID magnetization measurements. A comparative evaluation of the magnetic properties across the series reveals that the compounds exhibit antiferromagnetic coupling between the metal ions, except for [{NiIICl}4{ReII(triphos)(CN)3}4] that shows ferromagnetic behavior. Despite the large ground-state spin value of [{NiIICl}4{ReII(triphos)(CN)3}4] (S = 6), only manganese congeners exhibit SMM behavior to 1.8 K.

The Food Marketing Institute and the National Council of Chain Restaurants: animal welfare and the retail food industry in the United States of America.

Science.gov (United States)

Brown, K H; Hollingsworth, J

2005-08-01

In order to achieve real change, there must be a motivating force and all the stakeholders need to be involved. This is the premise of the animal welfare programme developed for the food retail, wholesale and chain restaurant industries in the United States of America (USA) by the Food Marketing Institute (FMI) and the National Council of Chain Restaurants (NCCR). This paper outlines a collaborative process that retailers and producers in the USA are using to enhance the care and welfare of animals in commercial food production. Although the efforts of the FMI and the NCCR are still underway, the process provides one example of how different parts of the food production system can work together to achieve positive change.

On Farm and Packhouse: Employment at the Bottom of a Global Value Chain

Science.gov (United States)

Dolan, Catherine S.

2004-01-01

The fresh vegetables commodity chain linking Kenyan producers with United Kingdom (UK) consumers employs significant numbers of workers in production and processing. This chain is dominated by UK retailers that determine the production imperatives of Kenyan firms upstream in the chain and, indirectly the employment strategies they adopt. This…

Unit-cell design for two-dimensional phase-field simulation of microstructure evolution in single-crystal Ni-based superalloys during solidification

Directory of Open Access Journals (Sweden)

Dongjia Cao

2017-12-01

Full Text Available Phase-field simulation serves as an effective tool for quantitative characterization of microstructure evolution in single-crystal Ni-based superalloys during solidification nowadays. The classic unit cell is either limited to γ dendrites along crystal orientation or too ideal to cover complex morphologies for γ dendrites. An attempt to design the unit cell for two-dimensional (2-D phase-field simulations of microstructure evolution in single-crystal Ni-based superalloys during solidification was thus performed by using the MICRESS (MICRostructure Evolution Simulation Software in the framework of the multi-phase-field (MPF model, and demonstrated in a commercial TMS-113 superalloy. The coupling to CALPHAD (CALculation of PHAse Diagram thermodynamic database was realized via the TQ interface and the experimental diffusion coefficients were utilized in the simulation. Firstly, the classic unit cell with a single γ dendrite along crystal orientation was employed for the phase-field simulation in order to reproduce the microstructure features. Then, such simple unit cell was extended into the cases with two other different crystal orientations, i.e., and . Thirdly, for crystal orientations, the effect of γ dendritic orientations and unit cell sizes on microstructure and microsegregation was comprehensively studied, from which a new unit cell with multiple γ dendrites was proposed. The phase-field simulation with the newly proposed unit cell was further performed in the TMS-113 superalloy, and the microstructure features including the competitive growth of γ dendrites, microsegregation of different solutes and distribution of γ′ grains, can be nicely reproduced.

The IASI detection chain

Science.gov (United States)

Nicol, Patrick; Fleury, Joel; Le Naour, Claire; Bernard, Frédéric

2017-11-01

IASI (Infrared Atmospheric Sounding Interferometer) is an infrared atmospheric sounder. It will provide meteorologist and scientific community with atmospheric spectra. The instrument is composed of a Fourier transform spectrometer and an associated infrared imager. The presentation will describe the spectrometer detection chain architecture, composed by three different detectors cooled in a passive cryo-cooler (so called CBS : Cold Box Subsystem) and associated analog electronics up to digital conversion. It will mainly focus on design choices with regards to environment constraints, implemented technologies, and associated performances. CNES is leading the IASI program in collaboration with EUMETSAT. The instrument Prime is ALCATEL SPACE responsible, notably, of the detection chain architecture. SAGEM SA provides the detector package (so called CAU : Cold Acquisition Unit).

Extended linear chain compounds

CERN Document Server

Linear chain substances span a large cross section of contemporary chemistry ranging from covalent polymers, to organic charge transfer com­ plexes to nonstoichiometric transition metal coordination complexes. Their commonality, which coalesced intense interest in the theoretical and exper­ imental solid state physics/chemistry communities, was based on the obser­ vation that these inorganic and organic polymeric substrates exhibit striking metal-like electrical and optical properties. Exploitation and extension of these systems has led to the systematic study of both the chemistry and physics of highly and poorly conducting linear chain substances. To gain a salient understanding of these complex materials rich in anomalous aniso­ tropic electrical, optical, magnetic, and mechanical properties, the conver­ gence of diverse skills and talents was required. The constructive blending of traditionally segregated disciplines such as synthetic and physical organic, inorganic, and polymer chemistry, crystallog...

[Loading and strength of single- and multi-unit fixed dental prostheses. 1. Retention and resistance

NARCIS (Netherlands)

Baat, C. de; Witter, D.J.; Meijers, C.C.A.J.; Vergoossen, E.L.; Creugers, N.H.J.

2014-01-01

The degree to which single- and multi-unit fixed dental prostheses are able to withstand loading forces is dependent, among other things, on the quality of their retention and resistance. The quality of the retention and resistance of the configuration of an abutment tooth prepared for a metal and

Structural transformations of carbon chains inside nanotubes

International Nuclear Information System (INIS)

Warner, Jamie H.; Ruemmeli, Mark H.; Bachmatiuk, Alicja; Buechner, Bernd

2010-01-01

In situ aberration-corrected high-resolution transmission electron microscopy is used to examine the structural transformations of carbon chains that occur in the interior region of carbon nanotubes. We find electron-beam irradiation leads to the formation of two-dimensional carbon structures that are freely mobile inside the nanotube. The inner diameter of the nanotube influences the structural transformations of the carbon chains. As the diameter of the nanotube increases, electron-beam irradiation leads to curling of the chains and eventually the formation of closed looped structures. The closed looped structures evolve into spherical fullerenelike structures that exhibit translational motion inside the nanotubes and also coalesce to form larger nanotube structures. These results demonstrate the use of carbon nanotubes as test tubes for growing small carbon nanotubes within the interior by using only electron-beam irradiation at 80 kV.

Fluorinated alkyl substances and technical mixtures used in food paper-packaging exhibit endocrine-related activity in vitro.

Science.gov (United States)

Rosenmai, A K; Taxvig, C; Svingen, T; Trier, X; van Vugt-Lussenburg, B M A; Pedersen, M; Lesné, L; Jégou, B; Vinggaard, A M

2016-07-01

Migration of chemicals from packaging materials to foods may lead to human exposure. Polyfluoroalkyl substances (PFAS) can be used in technical mixtures (TMs) for use in food packaging of paper and board, and PFAS have been detected in human serum and umbilical cord blood. The specific structures of the PFAS in TMs are often unknown, but polyfluorinated alkyl phosphate esters (PAPs) have been characterized in TMs, food packaging, and in food. PAPs can be metabolized into fluorotelomer alcohols (FTOHs) and perfluoroalkyl carboxylic acids (PFCAs). Some PFAS have endocrine activities, highlighting the need to investigate these effects. Herein, we studied the endocrine activity of less characterized PFAS, including short-chain PFCAs and FTOHs, PAPs, and TMs of unknown chemical composition. Long-chain PFCAs were also included. We applied seven assays covering effects on estrogen, glucocorticoid, androgen, and peroxisome proliferator-activated receptor (PPAR) activity, as well as steroidogenesis in vitro and ex vivo. In general, PAPs, FTOHs, TMs, and long-chain PFCAs showed estrogenic activity through receptor activation and/or increasing 17β-estradiol levels. Furthermore, short- and long-chain PFCAs activated PPARα and PPARγ. Collectively, this means that (i) PAPs, FTOHs, and PFCAs exhibit endocrine activity through distinct and sometimes different mechanisms, (ii) two out of three tested TMs exhibited estrogenic activity, and (iii) short-chain FTOHs showed estrogenic activity and short-chain PFCAs generally activate both PPARα and PPARγ with similar potency and efficacy as long-chain PFCAs. In conclusion, several new and divergent toxicological targets were identified for different groups of PFAS. © 2016 American Society of Andrology and European Academy of Andrology.

Cutting Food Waste through Cooperation along the Food Supply Chain

Directory of Open Access Journals (Sweden)

Christine Göbel

2015-01-01

Full Text Available Food produced but not used for human consumption is a waste of natural resources. In order to prevent and reduce food waste, the main causes have to be identified systematically along the food supply chain (FSC. The aim of this study is (1 to shed light on the causes and effects of food waste through the analysis of 44 qualitative expert interviews examining the processes and intermediaries along the German food chain and (2 to find methods to reduce it. Results indicate that food waste occurs at all stages in the food chain. Thus, there is no single culprit to be blamed. Besides, the identified reasons for food waste differ between product groups; not a single solution can cause notable change. Furthermore, the analysis demonstrates that the causes and effects of food waste are to be found at different stages of the value chain. Hence, it is of high importance to improve communication and to raise a new appreciation for food among all stakeholders of the food supply chain in order to develop a more sustainable food system. Information on the topic of food waste needs to be shared among all actors of the supply chain. They need to share responsibility and work together to reduce food waste.

Molecular analogs of the hemihelix: A computational study of chain molecules containing left- and right-handed helices

Science.gov (United States)

Pichierri, Fabio

2014-08-01

Using density functional theory (DFT) we design two novel chain molecules containing a left-handed (thia)helicene unit connected to a right-handed (thia)helicene unit via a phosphoroussbnd phosphorous (Psbnd P) bond. These chains represent the molecular analogs of the novel hemihelix structure recently discovered by a group of Harvard University scientists. The HOMO and LUMO levels of the heterochiral chains, termed hemihelicenes, are localized on the left- and right-handed blocks, respectively. In contrast, the frontier orbitals of the chains containing homochiral (thia)helicenes connected by a Psbnd P bond are delocalized all over the chain.

Chondroitin sulfate synthase-2 is necessary for chain extension of chondroitin sulfate but not critical for skeletal development.

Science.gov (United States)

Ogawa, Hiroyasu; Hatano, Sonoko; Sugiura, Nobuo; Nagai, Naoko; Sato, Takashi; Shimizu, Katsuji; Kimata, Koji; Narimatsu, Hisashi; Watanabe, Hideto

2012-01-01

Chondroitin sulfate (CS) is a linear polysaccharide consisting of repeating disaccharide units of N-acetyl-D-galactosamine and D-glucuronic acid residues, modified with sulfated residues at various positions. Based on its structural diversity in chain length and sulfation patterns, CS provides specific biological functions in cell adhesion, morphogenesis, neural network formation, and cell division. To date, six glycosyltransferases are known to be involved in the biosynthesis of chondroitin saccharide chains, and a hetero-oligomer complex of chondroitin sulfate synthase-1 (CSS1)/chondroitin synthase-1 and chondroitin sulfate synthase-2 (CSS2)/chondroitin polymerizing factor is known to have the strongest polymerizing activity. Here, we generated and analyzed CSS2(-/-) mice. Although they were viable and fertile, exhibiting no overt morphological abnormalities or osteoarthritis, their cartilage contained CS chains with a shorter length and at a similar number to wild type. Further analysis using CSS2(-/-) chondrocyte culture systems, together with siRNA of CSS1, revealed the presence of two CS chain species in length, suggesting two steps of CS chain polymerization; i.e., elongation from the linkage region up to Mr ∼10,000, and further extension. There, CSS2 mainly participated in the extension, whereas CSS1 participated in both the extension and the initiation. Our study demonstrates the distinct function of CSS1 and CSS2, providing a clue in the elucidation of the mechanism of CS biosynthesis.

General model of phospholipid bilayers in fluid phase within the single chain mean field theory

Energy Technology Data Exchange (ETDEWEB)

Guo, Yachong; Baulin, Vladimir A. [Departament d’Enginyeria Química, Universitat Rovira i Virgili, Av. dels Paisos Catalans 26, 43007 Tarragona (Spain); Pogodin, Sergey [Institute of Chemical Research of Catalonia, ICIQ, Av. Paisos Catalans 16, 43007 Tarragona (Spain)

2014-05-07

Coarse-grained model for saturated phospholipids: 1,2-didecanoyl-sn-glycero-3-phosphocholine (DCPC), 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC), 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) and unsaturated phospholipids: 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), 1,2- dioleoyl-sn-glycero-3-phosphocholine (DOPC) is introduced within the single chain mean field theory. A single set of parameters adjusted for DMPC bilayers gives an adequate description of equilibrium and mechanical properties of a range of saturated lipid molecules that differ only in length of their hydrophobic tails and unsaturated (POPC, DOPC) phospholipids which have double bonds in the tails. A double bond is modeled with a fixed angle of 120°, while the rest of the parameters are kept the same as saturated lipids. The thickness of the bilayer and its hydrophobic core, the compressibility, and the equilibrium area per lipid correspond to experimentally measured values for each lipid, changing linearly with the length of the tail. The model for unsaturated phospholipids also fetches main thermodynamical properties of the bilayers. This model is used for an accurate estimation of the free energies of the compressed or stretched bilayers in stacks or multilayers and gives reasonable estimates for free energies. The proposed model may further be used for studies of mixtures of lipids, small molecule inclusions, interactions of bilayers with embedded proteins.

Hafnium carbide nanocrystal chains for field emitters

International Nuclear Information System (INIS)

Tian, Song; Li, Hejun; Zhang, Yulei; Ren, Jincui; Qiang, Xinfa; Zhang, Shouyang

2014-01-01

A hafnium carbide (HfC) nanostructure, i.e., HfC nanocrystal chain, was synthesized by a chemical vapor deposition (CVD) method. X-ray diffractometer, field-emission scanning electron microscope, transmission electron microscope, and energy-dispersive X-ray spectrometer were employed to characterize the product. The synthesized one-dimensional (1D) nanostructures with many faceted octahedral nanocrystals possess diameters of tens of nanometers to 500 nm and lengths of a few microns. The chain-like structures possess a single crystalline structure and preferential growth direction along the [1 0 0] crystal orientation. The growth of the chains occurred through the vapor–liquid–solid process along with a negative-feedback mechanism. The field emission (FE) properties of the HfC nanocrystal chains as the cold cathode emitters were examined. The HfC nanocrystal chains display good FE properties with a low turn-on field of about 3.9 V μm −1 and a high field enhancement factor of 2157, implying potential applications in vacuum microelectronics.

78 FR 61948 - Culturally Significant Objects Imported for Exhibition Determinations: “Franz von Stuck”

Science.gov (United States)

2013-10-07

... the exhibition ``Franz von Stuck,'' imported from abroad for temporary exhibition within the United... the Frye Art Museum, Seattle, Washington, from on or about November 2, 2013, until on or about...

75 FR 53012 - Culturally Significant Objects Imported for Exhibition Determinations: “Treasures of Moscow...

Science.gov (United States)

2010-08-30

... Rublev Museum,'' imported from abroad for temporary exhibition within the United States, are of cultural... Determinations: ``Treasures of Moscow: Icons From the Andrey Rublev Museum'' SUMMARY: Notice is hereby given of... determine that the exhibition or display of the exhibit objects at the Museum of Russian Icons, Clinton, MA...

75 FR 82127 - Culturally Significant Objects Imported for Exhibition Determinations: “Central Nigeria Unmasked...

Science.gov (United States)

2010-12-29

... River Valley,'' imported from abroad for temporary exhibition within the United States, are of cultural... also determine that the exhibition or display of the exhibit objects at the Fowler Museum at UCLA, Los... Museum of African Art, Smithsonian Institution, Washington, DC, from on or about September 14, 2011...

Selective recruitment of single motor units in human flexor digitorum superficialis muscle during flexion of individual fingers.

Science.gov (United States)

Butler, T J; Kilbreath, S L; Gorman, R B; Gandevia, S C

2005-08-15

Flexor digitorum superficialis (FDS) is an extrinsic multi-tendoned muscle which flexes the proximal interphalangeal joints of the four fingers. It comprises four digital components, each with a tendon that inserts onto its corresponding finger. To determine the degree to which these digital components can be selectively recruited by volition, we recorded the activity of a single motor unit in one component via an intramuscular electrode while the subject isometrically flexed each of the remaining fingers, one at a time. The finger on which the unit principally acted was defined as the 'test finger' and that which flexed isometrically was the 'active' finger. Activity in 79 units was recorded. Isometric finger flexion forces of 50% maximum voluntary contraction (MVC) activated less than 50% of single units in components of FDS acting on fingers that were not voluntarily flexed. With two exceptions, the median recruitment threshold for all active-test finger combinations involving the index, middle, ring and little finger test units was between 49 and 60% MVC (60% MVC being the value assigned to those not recruited). The exceptions were flexion of the little finger while recording from ring finger units (median: 40% MVC), and vice versa (median: 2% MVC). For all active-test finger combinations, only 35/181 units were activated when the active finger flexed at less than 20% MVC, and the fingers were adjacent for 28 of these. Functionally, to recruit FDS units during grasping and lifting, relatively heavy objects were required, although systematic variation occurred with the width of the object. In conclusion, FDS components can be selectively activated by volition and this may be especially important for grasping at high forces with one or more fingers.

Use of palivizumab and infection control measures to control an outbreak of respiratory syncytial virus in a neonatal intensive care unit confirmed by real-time polymerase chain reaction.

LENUS (Irish Health Repository)

O'Connell, K

2011-04-01

Respiratory syncytial virus (RSV) is a potentially life-threatening infection in premature infants. We report an outbreak involving four infants in the neonatal intensive care unit (NICU) of our hospital that occurred in February 2010. RSV A infection was confirmed by real-time polymerase chain reaction. Palivizumab was administered to all infants in the NICU. There were no additional symptomatic cases and repeat RSV surveillance confirmed that there was no further cross-transmission within the unit. The outbreak highlighted the infection control challenge of very high bed occupancy in the unit and the usefulness of molecular methods in facilitating detection and management.

The generalized model of polypeptide chain describing the helix-coil transition in biopolymers

International Nuclear Information System (INIS)

Mamasakhlisov, E.S.; Badasyan, A.V.; Tsarukyan, A.V.; Grigoryan, A.V.; Morozov, V.F.

2005-07-01

In this paper we summarize some results of our theoretical investigations of helix-coil transition both in single-strand (polypeptides) and two-strand (polynucleotides) macromolecules. The Hamiltonian of the Generalized Model of Polypeptide Chain (GMPC) is introduced to describe the system in which the conformations are correlated over some dimensional range Δ (it equals 3 for polypeptide, because one H-bond fixes three pairs of rotation, for double strand DNA it equals to one chain rigidity because of impossibility of loop formation on the scale less than Δ). The Hamiltonian does not contain any parameter designed especially for helix-coil transition and uses pure molecular microscopic parameters (the energy of hydrogen bond formation, reduced partition function of repeated unit, the number of repeated units fixed by one hydrogen bond, the energies of interaction between the repeated units and the solvent molecules). To calculate averages we evaluate the partition function using the transfer-matrix approach. The GMPC allowed to describe the influence of a number of factors, affecting the transition, basing on a unified microscopic approach. Thus we obtained, that solvents change transition temperature and interval in different ways, depending on type of solvent and on energy of solvent- macromolecule interaction; stacking on the background of H-bonding increases stability and decreases cooperativity of melting. For heterogeneous DNA we could analytically derive well known formulae for transition temperature and interval. In the framework of GMPC we calculate and show the difference of two order parameters of helix-coil transition - the helicity degree, and the average fraction of repeated units in helical conformation. Given article has the aim to review the results obtained during twenty years in the context of GMPC. (author)

A New 1D Chained Coordination Polymer: Synthesis, Crystal Structure, Antitumor Activity and Luminescent Property

Directory of Open Access Journals (Sweden)

Xi-Shi Tai

2015-11-01

Full Text Available A new 1D chained coordination polymer of Zn(II, {[Zn(L2(4,4′-bipy]·(H2O}n(1 (HL = N-acetyl-l-phenylalanine; 4,4′-bipy = 4,4′-bipyridine has been synthesized and characterized by elemental analysis, IR and X-ray single crystal diffraction analysis. Theresults show that each asymmetric unit of Zn(II complex belongs to monoclinic, space group P21 with a = 11.421(2 Å, b = 9.2213(17 Å, c = 15.188(3 Å,β = 106.112(3°, V = 1536.7(5 Å3, Z = 2, Dc = 1.444 g·cm−3, µ = 0.857 mm−1, F(000 = 696, and final R1 = 0.0439, ωR2 = 0.1013. The molecules form one-dimensional chained structure by its the bridging 4,4′-bipyridine ligands. The antitumor activities and luminescent properties of Zn(II coordination polymer have also been investigated.

Redox-active on-surface polymerization of single-site divalent cations from pure metals by a ketone-functionalized phenanthroline

Energy Technology Data Exchange (ETDEWEB)

Skomski, Daniel; Tempas, Christopher D.; Bukowski, Gregory S.; Smith, Kevin A.; Tait, Steven L., E-mail: tait@indiana.edu [Department of Chemistry, Indiana University, 800 E. Kirkwood Ave., Bloomington, Indiana 47405 (United States)

2015-03-14

Metallic iron, chromium, or platinum mixing with a ketone-functionalized phenanthroline ligand on a single crystal gold surface demonstrates redox activity to a well-defined oxidation state and assembly into thermally stable, one dimensional, polymeric chains. The diverging ligand geometry incorporates redox-active sub-units and bi-dentate binding sites. The gold surface provides a stable adsorption environment and directs growth of the polymeric chains, but is inert with regard to the redox chemistry. These systems are characterized by scanning tunnelling microscopy, non-contact atomic force microscopy, and X-ray photoelectron spectroscopy under ultra-high vacuum conditions. The relative propensity of the metals to interact with the ketone group is examined, and it is found that Fe and Cr more readily complex the ligand than Pt. The formation and stabilization of well-defined transition metal single-sites at surfaces may open new routes to achieve higher selectivity in heterogeneous catalysts.

Simulation of Lean Principles Impact in a Multi-Product Supply Chain

OpenAIRE

Matteo, Rossini; Alberto, Portioli Staudacher

2015-01-01

The market competition is moving from the single firm to the whole supply chain because of increasing competition and growing need for operational efficiencies and customer orientation. Supply chain management allows companies to look beyond their organizational boundaries to develop and leverage resources and capabilities of their supply chain partners. This creates competitive advantages in the marketplace and because of this SCM has acquired strategic importance. Lean ...

76 FR 35068 - Culturally Significant Objects Imported for Exhibition Determinations; “Monet/Lichtenstein: Rouen...

Science.gov (United States)

2011-06-15

... for temporary exhibition within the United States, are of cultural significance. The objects are... exhibition or display of the exhibit objects at the Museum of Fine Arts, Boston, Boston, Massachusetts, from on or about July 3, 2011, until on or about September 18, 2011, the Los Angeles County Museum of Art...

78 FR 17744 - Culturally Significant Objects Imported for Exhibition Determinations: “Maya: Hidden Worlds...

Science.gov (United States)

2013-03-22

... Worlds Revealed,'' imported from abroad for temporary exhibition within the United States, are of... custodians. I also determine that the exhibition or display of the exhibit objects at The Science Museum of... Denver Museum of Nature and Science in Denver, Colorado from on or about February 14, 2014 until on or...

Antiretroviral procurement and supply chain management.

Science.gov (United States)

Ripin, David J; Jamieson, David; Meyers, Amy; Warty, Umesh; Dain, Mary; Khamsi, Cyril

2014-01-01

Procurement, the country-level process of ordering antiretrovirals (ARVs), and supply chain management, the mechanism by which they are delivered to health-care facilities, are critical processes required to move ARVs from manufacturers to patients. To provide a glimpse into the ARV procurement and supply chain, the following pages provide an overview of the primary stakeholders, principal operating models, and policies and regulations involved in ARV procurement. Also presented are key challenges that need to be addressed to ensure that the supply chain is not a barrier to the goal of universal coverage. This article will cover the steps necessary to order and distribute ARVs, including different models of delivery, key stakeholders involved, strategic considerations that vary depending on context and policies affecting them. The single drug examples given illustrate the complications inherent in fragmented supply and demand-driven models of procurement and supply chain management, and suggest tools for navigating these hurdles that will ultimately result in more secure and reliable ARV provision. Understanding the dynamics of ARV supply chain is important for the global health community, both to ensure full and efficient treatment of persons living with HIV as well as to inform the supply chain decisions for other public health products.

Conformational explosion: Understanding the complexity of short chain para-dialkylbenzene potential energy surfaces

Science.gov (United States)

Mishra, Piyush; Hewett, Daniel M.; Zwier, Timothy S.

2018-05-01

The single-conformation ultraviolet and infrared spectroscopy of three short-chain para-dialkylbenzenes (para-diethylbenzene, para-dipropylbenzene, and para-dibutylbenzene) is reported for the jet-cooled, isolated molecules. The present study builds off previous work on single-chain n-alkylbenzenes, where an anharmonic local mode Hamiltonian method was developed to account for stretch-bend Fermi resonance in the alkyl CH stretch region [D. P. Tabor et al., J. Chem. Phys. 144, 224310 (2016)]. The jet-cooled molecules are interrogated using laser-induced fluorescence (LIF) excitation, fluorescence dip infrared spectroscopy, and dispersed fluorescence. The LIF spectra in the S1 ← S0 origin region show a dramatic increase in the number of resolved transitions with increasing length of the alkyl chains, reflecting an explosion in the number of unique low-energy conformations formed when two independent alkyl chains are present. Since the barriers to isomerization of the alkyl chain are similar in size, this results in an "egg carton" shaped potential energy surface. A combination of electronic frequency shift and alkyl CH stretch infrared spectra is used to generate a consistent set of conformational assignments. Using these experimental techniques in conjunction with computational methods, subsets of origin transitions in the LIF excitation spectrum can be classified into different conformational families. Two conformations are resolved in para-diethylbenzene, seven in para-dipropylbenzene, and about nineteen in para-dibutylbenzene. These chains are largely independent of each other as there are no new single-chain conformations induced by the presence of a second chain. A cursory LIF excitation scan of para-dioctylbenzene shows a broad congested spectrum at frequencies consistent with interactions of alkyl chains with the phenyl π cloud.

Kinks, chains, and loop groups in the CPn sigma models

International Nuclear Information System (INIS)

Harland, Derek

2009-01-01

We consider topological solitons in the CP n sigma models in two space dimensions. In particular, we study 'kinks', which are independent of one coordinate up to a rotation of the target space, and 'chains', which are periodic in one coordinate up to a rotation of the target space. Kinks and chains both exhibit constituents, similar to monopoles and calorons in SU(n) Yang-Mills-Higgs and Yang-Mills theories. We examine the constituent structure using Lie algebras.

Grazer-induced chain lenght plasticity reduces grazing risk in a marine diatom

DEFF Research Database (Denmark)

Bergkvist, Johanna; Thor, Peter; Jakobsen, Hans Henrik

2012-01-01

. marinoi was exposed to chemical cues from caged A. tonsa without physical contact with the responding cells. The reductions in chain length significantly reduced copepod grazing; grazing rates on chains (four cells or more) were several times higher compared to that of single cells. This suggests...... that chain length plasticity is a means for S. marinoi to reduce copepod grazing. In contrast, chain length was not suppressed in cultures exposed to the microzooplankton grazer Gyrodinium dominans. Size-selective predation may have played a key role in the evolution of chain formation and chain length...... plasticity in diatoms...

77 FR 75253 - Culturally Significant Objects Imported for Exhibition Determinations: “Wait, Later This Will Be...

Science.gov (United States)

2012-12-19

... exhibition or display of the exhibit objects at the Museum of Modern Art, New York, New York, from on or... abroad for temporary exhibition within the United States, are of cultural significance. The objects are...

76 FR 64423 - Culturally Significant Objects Imported for Exhibition Determinations: “Projects 96: Haris...

Science.gov (United States)

2011-10-18

...: Haris Epaminonda'' imported from abroad for temporary exhibition within the United States, are of... custodian. I also determine that the exhibition or display of the exhibit objects at The Museum of Modern Art, New York, NY, from on or about November 17, 2011, until on or about February 20, 2012, and at...

78 FR 22362 - Culturally Significant Objects Imported for Exhibition Determinations: “40 Part Motet”

Science.gov (United States)

2013-04-15

...,'' imported from abroad for temporary exhibition within the United States, are of cultural significance. The... that the exhibition or display of the exhibit objects at The Cleveland Museum of Art, Cleveland, OH, from on or about May 4, 2013, until on or about June 9, 2013; The Metropolitan Museum of Art, New York...

78 FR 79057 - Public Notice; Culturally Significant Objects Imported for Exhibition Determinations: “Treasures...

Science.gov (United States)

2013-12-27

..., 1392-1910,'' imported from abroad for temporary exhibition within the United States, are of cultural... also determine that the exhibition or display of the exhibit objects at the Philadelphia Museum of Art, Philadelphia, PA, from on or about March 2, 2014, until on or about May 26, 2014; the Los Angeles County Museum...

77 FR 8943 - Culturally Significant Objects Imported for Exhibition Determinations: “Rembrandt's Self-Portrait”

Science.gov (United States)

2012-02-15

...-Portrait,'' imported from abroad for temporary exhibition within the United States, is of cultural... determine that the exhibition or display of the exhibit object at the Metropolitan Museum of Art, New York... of the object at the Museum of Fine Arts, Houston from on or about June 3, 2012 until on or about...