Multi-element System Research Articles

Current progress towards the use of aptamers in targeted cancer therapy

Aptamers are a class of oligonucleotides that can specifically bind to targeted molecules, such as proteins, ions, small compounds, and cell surface receptors. Their specificity and affinity properties are equal to those of antibodies and can be sometimes be stronger. Aptamers exhibit low immunogenicity and good stability, as well as the ability to conjugate with various drug carriers for the construction of targeted multi-element drug delivery systems. These systems have attracted considerable interest from researchers working in the field of biomedical research. This paper provides a review of the latest progress in research directed towards the use of aptamers bound to drugs or nanoparticle carriers, such polymers, inorganic nanoparticles (e.g., carbon nanotubes, graphene oxide, gold nanoparticles, mesoporous silica nanoparticles, quantum dots, and magnetic nanoparticles), dendrimers, liposomes, and micelles for the formation of targeted drug delivery systems for use in targeted cancer therapy.

HRMC_2.1: Hybrid Reverse Monte Carlo method with silicon, carbon, germanium and silicon carbide potentials

The Hybrid Reverse Monte Carlo (HRMC) code models the atomic structure of materials via the use of a combination of constraints including experimental diffraction data and an empirical energy potential. In this version 2.1 update, an empirical potential for silicon-carbide has been added to the code along with an experimentally motivated constraint on the bond type fraction applicable to systems containing multiple elements. New version program summaryProgram title: HRMC version 2.1Catalogue identifier: AEAO_v2_1Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEAO_v2_1.htmlProgram obtainable from: CPC Program Library, Queen’s University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 114084No. of bytes in distributed program, including test data, etc.: 1289369Distribution format: tar.gzProgramming language: FORTRAN 90.Computer: any computer capable of running executables produced by the Fortran 90 compiler. For example, the code runs in Windows 7, once compiled with the GNU Fortran 95 compiler.Operating system: Unix, Windows.Classification: 7.7.Catalogue identifier of previous version: AEAO_v2_0Journal reference of previous version: Comput. Phys. Comm. 184 (2013) 1946Does the new version supersede the previous version?: yesNature of problem:atomic modelling using a combination of empirical potentials, fits to experimental data and other chemically or physically motivated constraints.Solution method:single move Metropolis Monte Carlo method used to minimize the total energy and discrepancy between simulation and experimental data.Reasons for new version:extension of capabilities from old version.Summary of revisions:1.Inclusion of a bond-order potential for silicon carbide (P. Erhart, K. Albe, Phys. Rev. B 71 (2005) 035211). The selection of this potential is via the POT_TYPE parameter in the HRMC.inp file and the number of carbon and silicon atoms needs to be specified via the configA and configB parameters.2.Inclusion of a constraint on the bond type fraction for multi-elemental systems. If a simulation has elements A, B and C, this constraint allows one to fix for element A, the fraction of A–A, A–B and A–C bonds (which should sum to unity) and similarly for elements B and C. The constraint is turned on via the BT_OPTION in the HRMC.inp file and it has its constraint weightings labelled in each stage alongside the other constraint weightings. The BT_OPT(1), BT_OPT(2) and BT_OPT(3) parameters are used to select which elements have their bond type fractions fitted via this constraint.3.A new file is output called data_xyzdetail.dat. This file contains lists of the neighbour separations, bond angles and dihedral angles.4.The header file hrmc.h has been replaced with hrmc_data.f90 which replaces the common block with a module to define global variables.Running time:1000 s for test run on a Intel Xeon 2.93 GHz—Nehalem series processor

Extension of the HVE 1 MV multi-element AMS system for low background

HVE has extended its 1MV multi-element AMS system to enhance its performance on elements like 10Be and 14C as well as actinides like Pu. The original system is very compact, but had some inherent limitations on e.g. background and the mass resolution of the injector magnet. With the extension, system performance has improved in several aspects: For actinide measurements, the low-energy spectrometer is equipped with a 120° magnet featuring a high mass resolution (M/ΔM>1000) and a high bending power (340amu at 35keV), supporting e.g. injection of 244Pu19F5. For 3H AMS, all magnets are equipped with Hall-probe control. The accelerator is equipped with a dual gas stripper system. The high energy spectrometer was extended by a 30 degree magnet removing ions scattering in the high-energy ESA. This has improved the background for 10Be AMS by two orders of magnitude down to the low 10−16. For 14C AMS the magnet allows using charge state 1+ by suppressing scattered 13C to a level also in the low 10−16. The new system has a footprint of 10.4m×4.9m, including a second ion source in the injector and provisions for future implementation of an isobar separator for anions (ISA) for e.g. 36Cl measurements. The first extended system will be delivered to the Aarhus AMS 14C Dating Centre.

Ultrasonic imaging for appearance of vertical slot by reverse time migration

The problem in traditional industrial ultrasonic imaging methods is the difficulty to obtain the appearance or the shape of defects inside solid materials although the methods have the ability to detect and determine the position and lateral dimensions. These special defects, like the vertical slot or crack, are typical examples. Based on the multi-element array ultrasonic technique, the numerical and experimental studies on reverse time migration (RTM) ultrasonic imaging for metalic materials are carried out. In this paper, the objects in detecting and imaging experiments are aluminum samples with slot intersecting the bottom or interior slot, which cannot be effectively detected by traditional ultrasonic methods. First the single component ultrasonic field for RTM imaging is studied to obtain RTM ultrasonic imaging results based on numerical simulation and experimental measurements using a multi-element array ultrasonic testing system. Then, the RTM imaging techniques based on multi-component ultrasonic displacement field detection and converted shear wave separation are further studied, and a new approach using a multi-component laser interferometer is proposed. Numerical simulation results verify that the multi-component RTM imaging reconstructive method can overcome the shortcomings of single component method, and obtain better image quality.

Analytical Approach for Estimating Failure Probability of Multi-element Structural Systems with Load-path History

Probabilistic modeling of the failure process of a structural multi-element system with brittle behavior of the elements is much more difficult as compared with rigid-ideal-plastic structures. The basic reason for this is the redistribution of action effects and possible influence of the load-path history on the sequence of failures of individual elements, which strengths are considered as random variables. In the paper, a certain concept of systems with no-unloading is applied in a self-consistent way for probabilistic study of such systems. It is proved for the system with no-unloading that, within the well-defined assumptions on the action effects rule, the probability of system failure under a given action can be calculated via a fit-for-purpose analytical formula. For systems allowing unloading, a set of the so-called majorant action effects is introduced, which makes it possible to find an effective upper bound for the failure probability of the system with unloading.

Approach to combine structural with chemical composition profiles using resonant X-ray scattering

Resonant X-ray reflectivity can combine the layer sensitivity of the reflectivity technique with the chemical composition sensitivity of the absorption technique. The idea is demonstrated through a depth profile study of the chemical composition of a multi-element thin-film system at the soft X-ray spectral range near the boronKabsorption edge. The composition profile of a multi-element low-contrast (<0.6%) thin film is determined from the free surface to buried interfaces within a few atomic percentages of precision and with a nanometre depth resolution.

Processing blur of conflicting stimuli during the latency and onset of accommodation

The accommodative response (AR) to changes in dioptric accommodative stimulus (AS) during the latency period and onset of accommodation was investigated. Participants monocularly observed one period of a square wave in AS, with a 2-D baseline and mean, and amplitude 1 D or 2 D; the period of the square wave ranged from 0.10 s to 1.00 s; both increases and decreases were used for the first step in AS. At periods of 0.30s and longer, accommodation was found to respond to both levels of the stimulus. Rapid retinal monitoring appeared to be taking place for such stimuli. The amplitudes of peaks in AR did not usually depend on whether a particular level of AS occurred first or second, but for 8/40 conditions, a significant difference was found, with a stronger response when the level of AS occurred second. Null or incorrect responses were also observed in many trials, possibly linked with the natural microfluctuations of accommodation. Minimum response times to the changes in AS were observed, which increased with decreasing period of the AS. The time interval between peaks in the AR decreased with decreasing period of the AS. The findings were consistent with a parallel processing model previously proposed for saccades, where input from a later change in stimulus may enter an element of the control system when that element has finished processing an earlier change. More than one change in stimulus may therefore be passing through the multi-element control system at a time.

An inter-comparison of sediment classification methods based on multi-beam echo-sounder backscatter and sediment natural radioactivity data

This contribution presents sediment classification results derived from different sources of data collected at the Dordtse Kil river, the Netherlands. The first source is a multi-beam echo-sounder (MBES). The second source is measurements taken with a gamma-ray scintillation detector, i.e., the Multi-Element Detection System for Underwater Sediment Activity (Medusa), towed over the sediments and measuring sediment natural radioactivity. Two analysis methods are employed for sediment classification based on the MBES data. The first is a Bayesian estimation method that uses the average backscatter data per beam and, therefore, is independent of the quality of the MBES calibration. The second is a model-based method that matches the measured backscatter curves to theoretical curves, predicted by a physics-based model. Medusa provides estimates for the concentrations of potassium, uranium, thorium, and cesium, known to be indicative for sediment properties, viz. mean grain size, silt content, and the presence of organic matter. In addition, a hydrophone attached to the Medusa system provides information regarding the sediment roughness. This paper presents an inter-comparison between the sediment classification results using the above-mentioned methods. It is shown that although originating from completely different sources, the MBES and Medusa provide similar information, revealing the same sediment distribution.

New and effective multi-element α-hematite systems for reduction of trichloroethylene

The reactivity of different α-hematite (α-Fe2O3) systems for dechlorination of trichloroethylene (TCE) in the presence of Fe(II) and CaO was investigated. Initially different experiments were conducted to investigate the reactivity of pure and doped α-Fe2O3. It was found that the presence of elements such as Si, Cu, and Mn in α-Fe2O3 had a significant effect on TCE reduction potential of α-Fe2O3; however, the reduction potential was less than that of α-Fe2O3 (Bayferrox®-110 M, used in a previous study). Further studies were carried out and α-Fe2O3 was synthesized in a manner similar to that of Bayferrox®-110 M. This synthetic α-Fe2O3 showed improved reactivity and was found to follow pseudo-first-order kinetics when used in TCE reduction experiments. The preliminary end products analysis showed that TCE degradation was probably via β-elimination pathway. Detailed investigations of α-Fe2O3 systems were carried out using X-ray diffraction, X-ray fluorescence, and scanning electron microscopy with energy-dispersive spectrometry. The results demonstrated that the TCE reduction capacity of α-Fe2O3 was strongly dependent on the other elements present in iron powder used to synthesize α-Fe2O3. It was suspected that these multi-elements in α-Fe2O3 helped to improve its conduction property. Current findings suggest that α-Fe2O3 not in the pure but combined with other elements could be thought as a potential system for TCE reduction.

Enhancing the security of communication via directly modulated antenna arrays

A new approach to enhance the security of data transmission using direction dependent antenna modulation based on an array with wide element spacing combined with directional array elements is presented. For illustrative purposes, the system investigated, and reported here, consists of an array of only two elements but the approach is general and can be extended to multi-element array systems. It is shown that by increasing the element spacing of an array the directional error rate characteristics of the system, in a given direction, can be significantly improved. Furthermore, the directly modulated system shows superior error rate performance to that of an equivalent, conventionally modulated, system in the grating lobe directions. The error rate characteristics of the proposed system are analysed for two scenarios: firstly when the angular separation between an eavesdropper and the intended recipient is small and secondly for the case when a potential eavesdropper is located much closer to the transmit antenna than the intended recipient.

Excitation and Receiving Circuit Design for the Multi-Element Medical Ultrasonic Endoscope Probe

Multi-element ultrasonic probe applied in vivo, compared with the traditional probe applied in vitro or single-element probe, has its own specialty in working environment and structure. This paper designed an analog circuit applied in vivo including excitation and reception amplification for multi-element ultrasonic probe. The circuit provides an excitation and receiving front-end for the self-developed multi-element ultrasound endoscope imaging system. This ultrasound analog circuit can be used for d / 2 ultrasonic scanning along with the 16 element ultrasound transducer.

Movements that are both variable and optimal

This brief review addresses two major aspects of the neural control of multi-element systems. First, the principle of abundance suggests that the central nervous system unites elements into synergies (co-variation of elemental variables across trials quantified within the framework of the uncontrolled manifold hypothesis) that stabilize important performance variables. Second, a novel method, analytical inverse optimization, has been introduced to compute cost functions that define averaged across trials involvement of individual elements over a range of values of task-specific performance variables. The two aspects reflect two features of motor coordination: (1) using variable solutions that allow performing secondary tasks and stabilizing performance variables; and (2) selecting combinations of elemental variables that follow an optimization principle. We suggest that the conflict between the two approaches (a single solution vs. families of solutions) is apparent, not real. Natural motor variability may be due to using the same cost function across slightly different initial states; on the other hand, there may be variability in the cost function itself leading to variable solutions that are all optimal with respect to slightly different cost functions. The analysis of motor synergies has revealed specific changes associated with atypical development, healthy aging, neurological disorders, and practice. These have allowed formulating hypotheses on the neurophysiological mechanisms involved in the synergic control of actions.

Investigation on deck-stay interaction of cable-stayed bridges with appropriate initial shapes

This paper provides a variety of viewpoints to illustrate the mechanism of the deck-stay interaction with the appropriate initial shapes of cable-stayed bridges. Based on the smooth and convergent bridge shapes obtained by the initial shape analysis, the one-element cable system (OECS) and multi-element cable system (MECS) models of the Kao Ping Hsi Bridge in Taiwan are developed to verify the applicability of the analytical model and numerical formulation from the field observations in the authors' previous work. For this purpose, the modal analysis of the two finite element models are conducted to calculate the natural frequency and normalized mode shape of the individual modes of the bridge. The modal coupling assessment is also performed to obtain the generalized mass ratios among the structural components for each mode of the bridge. The findings indicate that the coupled modes are attributed to the frequency loci veering and mode localization when the "pure" deck-tower frequency and the "pure" stay cable frequency approach one another, implying that the mode shapes of such coupled modes are simply different from those of the deck-tower system or stay cables alone. The distribution of the generalized mass ratios between the deck-tower system and stay cables are useful indices for quantitatively assessing the degree of coupling for each mode. These results are demonstrated to fully understand the mechanism of the deck-stay interaction with the appropriate initial shapes of cable-stayed bridges.

Thermodynamic optimization and calculation of the YCl3–ACl (A=Li, Na, K, Rb, Cs) phase diagrams

The binary phase diagrams of the YCl3–ACl (A=Li, Na, K, Rb, Cs) systems were studied using the CALPHAD technique and nonlinear mathematical method. The new modified quasi-chemical model in the pair-approximation for short-range ordering was applied to describe the Gibbs energies of the liquid phase in these systems. And the paper created the Artificial Neural Networks (ANN) model to study the interaction coefficients of two ending compounds composing the binary systems which are important for thermodynamic study of multi-elements system. Based on measured phase equilibrium data, a set of thermodynamic functions has been optimized and calculated. The effects of ionic radius, electronegativity and mole fraction of YCl3 on interaction coefficients were investigated in more detail.

Reconstruction of the coupling architecture in an ensemble of coupled time-delay systems

The behavior of complex systems of different natures composed of several interacting elements depends on not only the properties of these elements, but also on the character of their coupling. For exam� ple, the structure and intensity of couplings in an ensemble of oscillating systems determines the possi� bility of their synchronization and the formation of different spatial and temporal structures [1–4]. In recent years, much attention has been paid to the problem of revealing the presence of couplings in ensembles of multielement systems and determining their structure and characteristics from time series [5– 7]; this problem is solved using methods based on sim� ulation of the phase dynamics. Here, we propose a method for reconstructing the coupling architecture and values in large ensembles of interacting systems based on a method for reconstructing the model equa� tions of ensemble elements. Using this method, we reconstructed for the first time the a priori unknown architecture of couplings in a large ensemble of cha�

The 1 MV multi-element AMS system for biomedical applications at the Netherlands Organization for Applied Scientific Research (TNO)

The Netherlands Organization for Applied Scientific Research (TNO) has installed a compact 1MV multi-element AMS system manufactured by High Voltage Engineering Europa B.V., The Netherlands. TNO performs clinical research programs for pharmaceutical and innovative foods industry to obtain early pharmacokinetic data and to provide anti-osteoporotic efficacy data of new treatments. The AMS system will analyze carbon, iodine and calcium samples for this purpose. The first measurements on blank samples indicate background levels in the low 10−12 for calcium and iodine, making the system well suited for these biomedical applications. Carbon blanks have been measured at low 10−16. For unattended, around-the-clock analysis, the system features the 200 sample version of the SO110 hybrid ion source and user friendly control software.

Reproducibility of the single-phase structural state of the multielement high-entropy Ti-V-Zr-Nb-Hf system and related superhard nitrides formed by the vacuum-arc method

The reproducibility of the single-phase structural state of the Ti-V-Zr-Nb-Hf multielement system (a high-entropy alloy) is demonstrated using the vacuum-arc method to prepare coatings based on this system. Single-phase high-entropy compounds with a bcc lattice typical of the molten state result from vacuum deposition; preparation in nitrogen atmosphere yields single-phases nitride superhard nanocrystalline coatings based on the fcc metallic lattice.

A multi-element thermal imaging system based on an uncooled bolometric array

A thermal imaging system based on a commercial uncooled microbolometric array of 384 × 288 elements has been developed and produced. The temperature and spatial resolutions of the system are <0.08°C and 0.96 mrad, respectively. The system has been designed to monitor the technical state of thermal power industry objects. Owing to the “open architecture” and the modular structure of the hardware and software, the system can be adapted for any thermal diagnostic task.

Wastewaters decontamination: Mechanisms of PB(II), ZN(II), and CD(II) competitive adsorption on tunisian smectite in single and multi‐solute systems

Polluted water may contain more than one heavy metal species. Consequently, the behavior of a particular metal in a water system may be affected by the presence of the others. In this study, the adsorption of Pb(II), Zn(II), and Cd(II) in single and multi‐element systems onto raw, acid‐activated, and aluminum‐pillared Tunisian smectite (RSM, ASM, and Al‐SM, respectively) was investigated as a function of pH and species concentrations. Physico‐chemical, Textural, XRD, and SEM analyses were investigated onto three different clay materials. The Al‐SM samples, which were calcined at 450°C, presented the best results for the surface areas (267 m2/g) and for the Pb(II) adsorption capacity (75.35 mg/g). For instance, once they contained in a batch system at 25°C, pH 6, they retained more heavy metals due to their textural characteristics. The selected order of adsorption Pb(II) &gt; Zn(II) &gt; Cd(II) showed the importance of the competitive phenomenon onto clay materials' pores adsorption. At a higher pH, the precipitation phenomenon was possible. The two‐site, Langmuir isotherm also yielded the best fit for Pb(II) and Zn(II) adsorption on RSM and Al‐SM in binary and ternary solute‐systems. However, it failed in the case of Pb(II), Zn(II), and Cd(II) on ASM, which had less heterogeneity than other samples. The obtained results can serve as baseline data to design an adsorption process using this local adsorbent for the wastewaters rich in heavy metals. © 2012 American Institute of Chemical Engineers Environ Prog, 32: 229‐238, 2013

Development of an extractive spectrophotometric method for estimation of uranium in ore leach solutions using 2-ethylhexyl phosphonic acid-mono-2-ethylhexyl ester (PC88A) and tri-n-octyl phosphine oxide (TOPO) mixture as extractant and 2-(5-bromo-2-pyridylozo)-5-diethyl aminophenol (Br-PADAP) as chromophore

An extractive spectrophotometric analytical method has been developed for the determination of uranium in ore leach solution. This technique is based on the selective extraction of uranium from multielement system using a synergistic mixture of 2-ethylhexyl phosphonic acid-mono-2-ethylhexyl ester (PC88A) and tri-n-octyl phosphine oxide (TOPO) in cyclohexane and color development from the organic phase aliquot using 2-(5-Bromo-2-pyridylazo)-5-diethyl aminophenol (Br-PADAP) as chromogenic reagent. The absorption maximum (λmax) for UO22+–Br-PADAP complex in organic phase samples, in 64% (v/v) ethanol containing buffer solution (pH 7.8) and 1,2-cyclohexylenedinitrilotetraacetic acid (CyDTA) complexing agent, has been found to be at 576nm (molar extinction coefficient, ɛ: 36,750±240Lmol−1cm−1). Effects of various parameters like stability of complex, ethanol volume, ore matrix, interfering ions etc. on the determination of uranium have also been evaluated. Absorbance measurements as a function of time showed that colored complex is stable up to >24h. Presence of increased amount of ethanol in colored solution suppresses the absorption of a standard UO22+–Br-PADAP solution. Analyses of synthetic standard as well as ore leach a solution show that for 10 determination relative standard deviation (RSD) is <2%. The accuracy of the developed method has been checked by determining uranium using standard addition method and was found to be accurate with a 98–105% recovery rate. The developed method has been applied for the analysis of a number of uranium samples generated from uranium ore leach solutions and results were compared with standard methods like inductively coupled plasma emission spectrometry (ICPAES). The determined values of uranium concentrations by these methods are within ±2%. This method can be used to determine 2.5–250μgmL−1 uranium in ore leach solutions with high accuracy and precision.