Triple Array Research Articles

A complete hyaluronan hydrodynamic characterization using a size exclusion chromatography–triple detector array system during in vitro enzymatic degradation

Size exclusion chromatography coupled with triple detection (online laser light scattering, refractometry, and viscosimetry) (SEC–TDA) was applied for the study of hyaluronan (HA) fragments produced during hydrolysis catalyzed by bovine testicular hyaluronidase (BTH). The main advantage this approach provides is the complete hydrodynamic characterization without requiring further experiments. HA was hydrolyzed using several BTH amounts and for increasing incubation times. Fragments were characterized in terms of weight and number average molecular weights ( M w and M n, respectively), polydispersity index ( M w/ M n), hydrodynamic radius ( R h), and intrinsic viscosity ([ η]). The Mark–Houwink–Sakurada (MHS) curves (log [ η] versus log M w) were then derived directly. Fragments covering a whole range of M w (10–900 kDa) and size ( R h = 4–81 nm) and presenting a rather narrow distribution of molar masses ( M w/ M n = 1.6–1.7) were produced. From the MHS curves, HA conformation resulted in a change from a random coil toward a rigid rod structure while decreasing the M w. HA enzymatic hydrolysis in the presence of a BTH inhibitor was also monitored, revealing that inhibition profiles are affected by ionic strength. Finally, a comparison of the kinetic data derived from SEC–TDA with the data from rheological measurements suggested different strengths of the two methods in the determination of the depolymerization rate depending on the hydrolysis conditions.

WADM and radiation MHD simulations of compact multi-planar and cylindrical wire arrays at 1 MA currents

The radiative performance of Z-pinches created by the imploding wire array loads is defined by the ablation and implosion dynamics of these loads. Both these processes can be effectively modeled by the Wire Ablation Dynamics Model (WADM), which extends the formalism exploited earlier for the cylindrical wire arrays to the loads of arbitrary geometries. The WADM calculates the ablation rates for each array wire and provides the important dynamic parameters, such as the specific mass and velocity of the imploding plasma, which can be used to estimate the shapes of the x-ray pre-pulse and, partially, the main x-ray burst. The applications of the WADM also extend to combined material wire array loads. The ablation and implosion dynamics of novel Prism Planar Wire Array (PPWA) and combined material (Mo/Al/Mo) Triple Planar Wire Array (TPWA) loads are discussed in detail. The combined WADM and radiation MHD simulation is applied to model the radiative performance of the precursor plasma column, created by the imploding stainless steel compact cylindrical wire array. As the radiation effects intensify with the mass accumulation at the array center, the simulation reveals the transformation of quasi-uniform precursor column into a heterogeneous plasma structure with strong density and temperature gradients. We find that radiative performance of the precursor plasma is greatly affected by the load geometry as well as by the wire material.

Atomic structure of a regular Si(2 2 3) triple step staircase

An atomically accurate regular triple step array with a period of 4.8 nm has been fabricated on the vicinal Si(5 5 7) surface. Its atomic structure was studied on different length scales by scanning tunneling microscopy, low energy electron diffraction and photoelectron spectroscopy. These complementary methods allowed to identify the average orientation of the regular triple step staircase as Si(2 2 3) and to give a deeper insight into the atomic arrangement of this structure.

Electronic transport in a side-coupled triple quantum dot array

The electronic transport through a side-coupled triple quantum dot array (QDA) is investigated by means of Green function technique within the tight-binding framework. We obtain the formula of the linear conductance of QDA. The linear conductance spectrum is numerically studied. We discuss the feasibility of applying our structure to the electron spin polarized device and calculate the ratio of the spin polarized current flows.

Synthesis, Characterization, and Viscoelastic Properties of High Molecular Weight Hyperbranched Polyglycerols

Very high molecular weight (Mn up to 700 000) and narrowly polydispersed (PDI = 1.1−1.4) hyperbranched polyglycerols (HPG) were synthesized by ring-opening multibranching polymerization of glycidol using dioxane as an emulsifying agent. Broader molecular weight distributions with low molecular weight fractions were obtained when diglyme was used as the emulsifying agent. But the low molecular weight fractions could be removed by dialysis. Isolated yields in both the cases were 70−90%. The different result in the case of dioxane may be due to faster cation exchange which leads to low polydispersites. HPGs of various molecular weights were characterized by a GPC system coupled with a multiangle laser light scattering detector and a triple detector array. The intrinsic viscosities were low for these polymers and did not increase with molecular weight. The dimensions of these polymers (Rg, Rh, Rη) and their dependence on molecular weights are described. The hydrodynamic radii were very small with dimensions s...

Trix, a novel Rac guanine-nucleotide exchange factor from Dictyostelium discoideum is an actin-binding protein and accumulates at endosomes

Small Rho family GTPases are involved in regulation of actin cytoskeleton dynamics. These molecular switches are themselves mainly controlled by specific GTPase-activating proteins (GAPs) and guanine-nucleotide exchange factors (GEFs). We have cloned and initially characterized a novel putative RhoGEF from Dictyostelium discoideum. The predicted 135-kDa protein displays a unique domain organization in its N-terminus by harboring two type3 calponin homology (CH) domains followed by a single type1 CH domain. The C-terminal region encompasses a diffuse B-cell lymphoma homology/pleckstrin homology tandem domain that is typically found in RhoGEFs. We therefore refer to this protein as Trix (triple CH-domain array exchange factor). A recombinant N-terminal region of Trix carrying all three CH domains binds to F-actin and bundles actin filaments. Trix-null mutants are viable and display only subtle defects when compared to wild-type cells with the exception of a substantial decrease in exocytosis of a fluid-phase marker. GFP fusions with the full-length protein or the N-terminal part containing all three CH domains revealed that Trix localizes to the cortical region and strongly accumulates on late endosomes. Our results suggest that Trix is specifically involved in a Rho GTPase-signaling pathway that is required for regulation of the actin cytoskeleton during exocytosis.

Measurement of Reynolds Stress and Zonal Flows in a Tokamak Using Langmuir Probe Array

AbstractThe Reynolds stress and zonal flows have been measured with several novel Langmuir probe array on the HT‐7 tokamak since the year 2002. Based on the original idea of the Reynolds stress triple tips array, we designed the forked probe and its improved generation, the farmer fork probe. And in order to measure the radial shearing rate of zonal flows, we designed the pyramid probe in 2003. Besides, an insert‐able magnetic probe was elaborated to measure the Maxwell stress in 2003. This paper addresses the technique aspects regarding this new application. Since the zonal flows dynamics is now widely believed crucial to plasma confinement physics, this opened up an important application field of Langmuir probe. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Series summation of fractal fluctuations in electron billiard arrays

We fabricate a single billiard, a double billiard array, and a triple billiard array by etching a GaInAs/InP heterostructure, and perform a fractal analysis of the low-temperature magneto-conductance fluctuations measured in the billiards to facilitate an empirical study of how fractals combine in a physical system. We compare our results to simulated fractal traces, and find for both experiment and simulation that fluctuations of similar fractal dimension combine to form fluctuations of the same fractal dimension.

Measurement of Zonal Flows in a Tokamak Using Langmuir Probe Array

Zonal flows have been measured with several novel Langmuir probe array on the HT-7 tokamak since 2002. The forked probe and its improved generation, the farmer forked probe were designed based on the original idea of the Reynolds stress triple tips array. In order to measure the radial shearing rate of zonal flows, the pyramid probe was also designed. This paper addresses the technical aspects regarding this new application. Since the zonal flows dynamics is now widely believed crucial to plasma confinement physics, an important application field of Langmuir probe was opened up.

Double Arrays, Triple Arrays and Balanced Grids with v=r+c −1

In Theorem 6.1 of McSorley et al. [3] it was shown that, when v=r+c?1, every triple array TA(v,k,?rr,?cc,k:r× c) is a balanced grid BG(v,k,k:r × c). Here we prove the converse of this Theorem. Our final result is: Let v=r+c?1. Then every triple array is a TA(v,k,c?k,r?k,k:r× c) and every balanced grid is a BG(v,k,k:r× c), and they are equivalent.

Molecular Weight Determination of Heparin and Dermatan Sulfate by Size Exclusion Chromatography with a Triple Detector Array

The determination of molecular weight (M) and molecular weight distribution (MD) of heparins by a novel approach, consisting of a high performance size exclusion chromatography (HP-SEC) combined with a triple detector array (TDA) is described. HP-SEC/TDA permits the evaluation of MD of polymeric samples through a combined and simultaneous action of three on-line detectors, right-angle laser light scattering (RALLS), refractometer (RI), and viscometer. The method does not require any chromatographic column calibration, thus overcoming also the difficulty to obtain adequate reference standards. It permits the size determination also of small molecules, even when scattering dissimmetry is not observable. Unfractionated heparins, eight fractions of a size fractionated heparin, and dermatan sulfates were analyzed by HP-SEC/TDA. The M values found for the heparin fractions were used to build up a calibration curve of a conventional HP-SEC system: the results obtained analyzing unfractionated heparin samples with both HP-SEC/TDA and HP-SEC were in excellent agreement, suggesting the possibility to use the TDA data to generate standard samples with known MD and intrinsic viscosity [eta]. Moreover, HP-SEC/TDA can successfully be employed also for the determination of the Mark-Houwink a and k parameters.

Reversible Catalyst Supporting via Hydrogen-Bonding-Mediated Self-Assembly for Atom Transfer Radical Polymerization of MMA

Atom transfer radical polymerization (ATRP) is a very useful living/controlled radical polymerization process for polymer synthesis, but its products are contaminated with transition metal catalyst residue. Catalyst immobilization on solids via covalent binding has the advantages of easy catalyst separation and reuse, but it deteriorates the control of the polymerization due to the slowed radical deactivation, which causes chain termination and uncontrolled propagation. In this paper, we report a reversible catalyst supporting concept via hydrogen-bonding-mediated self-assembly. The support acts as a “catalyst sponge” releasing the catalyst as free molecules at elevated temperatures for effective catalysis but absorbing the catalyst after the polymerization for separation. The support was polystyrene gel functionalized with maleimide or thymine units, and the catalyst was tethered on a diaminopyridine unit. A triple hydrogen bond array formed between maleimide or thymine and diaminopyridine at room temperature but broke at elevated temperatures. At 60 °C, the reversibly supported catalyst efficiently polymerized MMA in a well-controlled living manner, yielding PMMA with polydispersity as low as those by unsupported catalysts. The recycled catalysts still mediated MMA polymerization with a much improved control.

Anion control of ligand self-recognition in a triple helical array.

Self-assembly of the ligand L(1) with Co(2+) into a dinuclear triple helicate [Co(2)(L(1))(3)](4+) produces an anion binding pocket which encapsulates perchlorate anions. Furthermore we demonstrate how this ability to bind anions can control ligand self-recognition properties.

Langmuir probe array for edge plasma study on the compact helical system heliotron/torsatron

In order to study plasma behaviors and transport in edge plasma region, a triple probe array is installed on the compact helical system (CHS) heliotron/torsatron. The probe array is designed to measure the radial profiles of electron temperature, electron density, plasma potential and these fluctuations, simultaneously. The standard triple probe technique does not supply reliable results unless all electrodes are on the same magnetic surface. Then we also use the modified triple probe technique based on five electrodes, which provides precise fluctuations of electron temperature. In edge plasma region of neutral beam injection (NBI) heated plasmas on CHS, plasma profiles and their fluctuations are measured by the newly installed triple probe array. In the region of ρ≃0.95∼1.1, Boltzman relationship ñe/〈ne〉≃Ṽs/〈Te〉 is roughly satisfied and temperature fluctuation T̃e/〈Te〉 is by a factor of 3 smaller than density fluctuation ñe/〈ne〉. In sawtoothing plasmas, we also measure these plasma parameters, their gradients, and plasma fluctuations. Electron temperature and the gradient transiently increase associated with each sawtooth crash, but electron density and the gradient show the opposite behavior. Radial electrical field and the gradient are also modulated by sawtooth crashes. Correlation between the increased radial electrical field gradient and fluctuations, however, is unclear in these plasmas.

A conjugated triple strand porphyrin array

Download options Please wait... Article information DOI https://doi.org/10.1039/A903883C Article type Paper Download Citation Chem. Commun., 1999, 1539-1540 BibTex EndNote MEDLINE ProCite ReferenceManager RefWorks RIS Permissions Request permissions A conjugated triple strand porphyrin array G. Scott Wilson and H. L. Anderson, Chem. Commun., 1999, 1539 DOI: 10.1039/A903883C To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page. If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given. If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page. Read more about how to correctly acknowledge RSC content. Social activity Tweet Share Search articles by author G. Scott Wilson Harry L. Anderson

Sampling theorem in macroscopic electrodynamics of crystal lattices

Two ways may be used to describe the electromagnetic field-condensed media interaction. When one way is to get over a discrete structure of a medium by the averaging procedure, another way may be conceived as follows: to discretize fields on the basis of the discrete structure of a medium. When initial restrictions to the wave number spectrum take place, one can use the so-called sampling theorem for a medium modeled as a triple infinite periodic array of identical \ensuremath{\delta}-functional scattering elements. Taking into account the Lorenz-Lorentz model one can develop a dynamical theory which considers strong field fluctuations in crystal lattices.

An efficient method for storing and retrieving graph structures

Graphs are a typical and basic data structure for computer algorithms. Two-dimensional arrays and lists are well-known graph representations. These data representations have contrasting features for retrieval time and space efficiency. Aho et al. [3] proposed a method for combining the compactness of the list with the fast retrieval of the array. Applications of Aho's scheme were, however, limited to static data structures because the updating algorithm was not given. By introducing three one-dimensional arrays based on Aho's data structure, called a triple-array structure, this paper proposes a method for updating arcs stored in the triple array without degrading the worst-case retrieval time complexity O(1). The triple array maps arcs into two one-dimensional arrays CHECK and NEXT according to another one-dimensional arrayBASE. The updating algorithm presented here moves the initial positions of the arcs into other possible positions in the triple array by a first-fit strategy which searches the array CHECK starting from the head. For large graphs, the updating algorithm is improved by introducing the criterion of searching the array CHECK locally. Theoretical and experimental observations show that the updating time of the triple array becomes practical while keeping a worst-case retrieval time complexity of 0(1).

Integral equation analysis of artificial media

This paper presents an integral equation and method of moments (MM) solution to determine the effective permittivity and permeability of an artificial medium. The artificial medium is modeled as a triple infinite periodic array of identical scattering elements. A plane wave of unknown phase constant is assumed to propagate in the periodic medium in a given direction, and the periodic moment method (PMM) is used to set up a matrix equation for the currents on the center element of the periodic array. By setting the determinant of the PMM impedance matrix to zero, one can determine the phase constant of the plane wave, and then the effective permittivity and permeability of the artificial medium. >

A practical method for implementing string pattern matching machines

A compact and fast data structure is presented to implement the static transition table of a string pattern matching machine that locates all occurrences of a finite number of keywords in a text string. The approach is related to a triple-array structure for implementing the transition table of a finite state machine, and the structure has been utilized by many users as compiler-compilers LEX and YACC in UNIX systems. By restricting the transition table of the finite state machine to that of the string pattern matching machine, the triple-array structure can be reduced to a structure of two arrays. The matching algorithm can be speeded up by a finite straight program without loops. It is shown by theoretical and empirical observations that the pattern matching machine by the presented structure is about 33% smaller and about 1.3 times faster than that by the triple array.

Turbulent mixing in coflowing plane jets

AbstractThe scalar mixing field of a single plane jet and an array of three coflowing plane jets has been examined using marker nephelometry. Results are reported for the centreline behaviour of the mean and fluctuation concentration fields of the single jet and the triple jet array with Gi/Go = 1.39, 0.222 and 0.089, where Gi is the centre jet momentum and Go the momentum of both outer jets. Details of the flow scales including the half concentration width and integral scales are also reported for the single plane jet and the triple jet case with Gi/Go = 1.39 and 0.089. The centreline measurements were extended to the region where a tendency to axisymmetric behaviour was observed.