Enrichment Scheme Research Articles

Colorimetric immunodetection of bacteria enriched on membranes within a compact multichannel filtration device

Colorimetric immunoassay is a widely used method for pathogen detection. The conventional implementation of immunoassays in 96-well plates often encounters difficulties for samples with low concentrations. In this study, the detection performance has been improved using a cellulose acetate membrane for target enrichment and immunodetection. For this end, a compact multichannel filtration device was fabricated using a 3D printer for sample loading. Background effects of the membrane were greatly minimized after pretreatment with a sodium hydroxide solution to significantly reduce non-specific binding. The colorimetric result of the immunodetection of Escherichia coli strain K12 (E.coli K12) was recorded and quantitatively analyzed with a smartphone camera. A limit of detection was calculated as 40 cfu (colony forming unit)/ml, two orders of magnitude more sensitive than that obtained on 96-well plates with standard protocol. The developed approach features an integrated sample enrichment scheme, reduced reagents consumption, multiple channels for parallel processing and no reliance on advanced laboratory instruments, thereby providing potential for a low-cost and easy-to-use immunodetection system.

A posteriori error analysis of an enriched Galerkin method of order one for the Stokes problem

Abstract We derive optimal reliability and efficiency of a posteriori error estimates for the steady Stokes problem, with a nonhomogeneous Dirichlet boundary condition, solved by a stable enriched Galerkin scheme (EG) of order one on triangular or quadrilateral meshes in ℝ2, and tetrahedral or hexahedral meshes in ℝ3.

On the topological enrichment for crack modeling via the generalized/extended FEM: a novel discussion considering smooth partitions of unity

Purpose It has been usual to prefer an enrichment pattern independent of the mesh when applying singular functions in the Generalized/eXtended finite element method (G/XFEM). This choice, when modeling crack tip singularities through extrinsic enrichment, has been understood as the only way to surpass the typical poor convergence rate obtained with the finite element method (FEM), on uniform or quasi-uniform meshes conforming to the crack. Then, the purpose of this study is to revisit the topological enrichment strategy in the light of a higher-order continuity obtained with a smooth partition of unity (PoU). Aiming to verify the smoothness' impacts on the blending phenomenon, a series of numerical experiments is conceived to compare the two GFEM versions: the conventional one, based on piecewise continuous PoU's, and another which considers PoU's with high-regularity. Design/methodology/approach The stress approximations right at the crack tip vicinity are qualified by focusing on crack severity parameters. For this purpose, the material forces method originated from the configurational mechanics is employed. Some attempts to improve solution using different polynomial enrichment schemes, besides the singular one, are discussed aiming to verify the transition/blending effects. A classical two-dimensional problem of the linear elastic fracture mechanics (LEFM) is solved, considering the pure mode I and the mixed-mode loadings. Findings The results reveal that, in the presence of smooth PoU's, the topological enrichment can still be considered as a suitable strategy for extrinsic enrichment. First, because such an enrichment pattern still can treat the crack independently of the mesh and deliver some advantage in terms of convergence rates, under certain conditions, when compared to the conventional FEM. Second, because the topological pattern demands fewer degrees of freedom and impacts conditioning less than the geometrical strategy. Originality/value Several outputs are presented, considering estimations for the J–integral and the angle of probable crack advance, this last computed from two different strategies to monitoring blending/transition effects, besides some comments about conditioning. Both h- and p-behaviors are displayed to allow a discussion from different points of view concerning the topological enrichment in smooth GFEM.

Fracture analysis for materials by a stable generalized/extended finite element method

ABSTRACT In this paper, a method is proposed for extracting fracture parameters in isotropic material cracking via a stable generalized/extended finite element method. The numerical results of the stress intensity factors and scaled condition number of the system matrix are presented and compared with different enrichment schemes or those reported in related references. The good agreement and convergence of the results obtained by the developed method with those obtained by other solutions or enrichment schemes proves the applicability of the proposed approach and confirms its capability of efficiently extracting fracture parameters in isotropic materials.

Neumann enriched polynomial chaos approach for stochastic finite element problems

An enrichment scheme based upon the Neumann expansion method is proposed to augment the deterministic coefficient vectors associated with the polynomial chaos expansion method. The proposed approach relies upon a split of the random variables into two statistically independent sets. The principal variability of the system is captured by propagating a limited number of random variables through a low-ordered polynomial chaos expansion method. The remaining random variables are propagated by a Neumann expansion method. In turn, the random variables associated with the Neumann expansion method are utilised to enrich the polynomial chaos approach. The effect of this enrichment is explicitly captured in a new augmented definition of the coefficients of the polynomial chaos expansion. This approach allows one to consider a larger number of random variables within the scope of spectral stochastic finite element analysis in a computationally efficient manner. Closed-form expressions for the first two response moments are provided. The proposed enrichment method is used to analyse two numerical examples: the bending of a cantilever beam and the flow through porous media. Both systems contain distributed stochastic properties. The results are compared with those obtained using direct Monte Carlo simulations and using the classical polynomial chaos expansion approach.

Hydrometallurgical enrichment of polymetallic and ferromanganese ore

The article presents the results of theoretical and experimental studies of leaching of polymetallic manganese-containing and ferromanganese ore. Thermodynamic calculations and experimental studies on enrichment of manganese-containing raw materials made it possible to determine the main technological parameters of the extraction of manganese, iron and non-ferrous metals, and to develop technological schemes for enrichment of various types of manganese-containing raw materials. The studies were carried out for polymetallic and ferromanganese ores of the Kaigadat deposit, the Selezen deposit, the Sugul site, located in the Kemerovo Region – Kuzbass. Before carrying out laboratory studies, the authors have performed thermodynamic analysis of ore leaching, chemical and X-ray structural analyzes of the samples. Laboratory tests were carried out on a multichamber autoclave unit MKA-4-75 using calcium and iron chlorides as solvents. Since the introduction of a reducing agent into the charge during leaching significantly improves the conditions for dissolution of oxides and hydroxides of manganese in calcium chloride, a series of experiments was conducted with the use of charcoal in the charge. Thermodynamic calculations have shown that the leaching process is fully implemented in the temperature range from 323 to 673 K. The results of the experiments confirmed the theoretical research results. The obtained data allowed the authors to propose a technological scheme for hydrometallurgical enrichment of polymetallic and ferromanganese ores to produce high-quality concentrates. All processed products are suitable for use. The use of optimal technological parameters of enrichment allows 95–97 % of manganese, up to 80 % of nickel, up to 99 % of cobalt, and 96–98 % of iron to be extracted from polymetallic manganese-containing raw materials. As a result of the deposition of these elements, high-quality concentrates of manganese, nickel, iron, cobalt are obtained. According to the proposed technological scheme for ferromanganese raw materials with a high content of silicates, it is possible to obtain high-quality concentrates of manganese and iron, while the extraction of manganese is 90–92 %, and of iron – 86–90 %.

An Extensible Data Enrichment Scheme for Providing Intelligent Services in Internet of Things Environments

Recent technologies in the Internet of Things (IoT) environment aim to provide intelligent services to users. Intelligent services can be managed and executed by systems that handle context information sets. Handling intelligent services leads to three major considerations: objects in the real world that should be described as metadata, a data enrichment procedure from sensing values for representing states, and controlling functionalities to manage services. In this study, an extensible data-enrichment scheme is proposed. The proposed scheme provides a way to describe profiles, data abstraction procedures, and functionalities that support the building of context information sets derived from raw datasets in the manner of a semantic web stack. Finally, data enrichment will help any system that uses context information by providing improved, understandable, and readable datasets to the service developers or the systems themselves.

A novel approach to investigate chemical inhomogeneities in GRB host galaxies: the Zabs–Zemiss relation

ABSTRACT Models of chemical enrichment and inhomogeneity in high-redshift galaxies are challenging to constrain observationally. In this work, we discuss a novel approach to probe chemical inhomogeneities within long gamma-ray burst (GRB) host galaxies, by comparing the absorption metallicity, Zabs, from the GRB afterglow (which probes the environment along the line of sight) with the emission-line metallicity, Zemiss, measured via slit spectroscopy. Using the IllustrisTNG simulation, the theoretical relationship between these metallicity metrics is explored for a range of GRB formation models, varying the GRB progenitor metallicity threshold. For galaxies with fixed Zemiss, the median value of Zabs depends strongly on the GRB progenitor threshold metallicity, with Zabs significantly lower than Zemiss for high-metallicity hosts. Conversely, at fixed Zabs, the median value of Zemiss depends primarily on the metallicity distribution of galaxies in IllustrisTNG and their chemical inhomogeneities, offering a GRB model-independent way to constrain these processes observationally. Currently, only one host galaxy has data for both absorption and emission metallicities (GRB121014A). We re-analyse the emission spectrum and compare the inferred metallicity Zemiss to a recent Bayesian determination of Zabs, finding $\log (Z_{\rm emiss}/Z_{\odot }) = \log (Z_{\rm abs}/Z_{\odot }) +0.35^{+ 0.14}_{- 0.25}$, within ∼2 standard deviations of predictions from the IllustrisTNG simulation. Future observations with the James Webb Space Telescope will be able to measure Zemiss for four other GRB hosts with known Zabs values, using ∼2-h observations. While small, the sample will provide preliminary constraints on the Zabs–Zemiss relation to test chemical enrichment schemes in cosmological simulations.

Strategy to Improve Edge-Based Smoothed Finite Element Solutions Using Enriched 2D Solid Finite Elements

In this paper, we present an automatic procedure that enhances the solution accuracy of edge-based smoothed 2D solid finite elements (three-node triangular and four-node quadrilateral elements). To obtain an enhanced solution, an adaptive enrichment scheme that uses enriched 2D solid finite elements and can effectively improve solution accuracy by applying cover functions adaptively without mesh-refinement is adopted in this procedure. First, the error of the edge-based finite element solution is estimated using a devised error estimation method, and appropriate cover functions are assigned for each node. While the edge-based smoothed finite elements provide piecewise constant strain fields, the proposed enrichment scheme uses the enriched finite elements to obtain a higher order strain field within the finite elements. Through various numerical examples, we demonstrate the accuracy improvement and efficiency achieved.

Cell Type-specific Adaptive Signaling Responses to KRASG12C Inhibition.

Covalent inhibitors of KRASG12C specifically target tumors driven by this form of mutant KRAS, yet early studies show that bypass signaling drives adaptive resistance. Although several combination strategies have been shown to improve efficacy of KRASG12C inhibitors (KRASi), underlying mechanisms and predictive strategies for patient enrichment are less clear. We performed mass spectrometry-based phosphoproteomics analysis in KRASG12C cell lines after short-term treatment with ARS-1620. To understand signaling diversity and cell type-specific markers, we compared proteome and phosphoproteomes of KRASG12C cells. Gene expression patterns of KRASG12C cell lines and lung tumor tissues were examined. Our analysis suggests cell type-specific perturbation to ERBB2/3 signaling compensates for repressed ERK and AKT signaling following ARS-1620 treatment in epithelial cell type, and this subtype was also more responsive to coinhibition of SHP2 and SOS1. Conversely, both high basal and feedback activation of FGFR or AXL signaling were identified in mesenchymal cells. Inhibition of FGFR signaling suppressed feedback activation of ERK and mTOR, while AXL inhibition suppressed PI3K pathway. In both cell lines and human lung cancer tissues with KRASG12C, we observed high basal ERBB2/3 associated with epithelial gene signatures, while higher basal FGFR1 and AXL were observed in cells/tumors with mesenchymal gene signatures. Our phosphoproteomic study identified cell type-adaptive responses to KRASi. Markers and targets associated with ERBB2/3 signaling in epithelial subtype and with FGFR1/AXL signaling in mesenchymal subtype should be considered in patient enrichment schemes with KRASi.

Design of Z-Source Inverter-Based Dynamic Voltage Restorer Circuitry with R-SOGI Control Scheme for Enrichment of Power Quality

Increased utilization of nonlinear loads in the power distribution system with profound integration of renewable energy requires improved power quality control. This paper proposes a Reformed Second Order Generalized Integrated (R-SOGI) control scheme for enhancing the output of the Dynamic Voltage Restorer (DVR) for the objective of achieving the desired sinusoidal voltage wave shape at the common point of services and harmonic reduction. The DVR incorporates a Solar Photovoltaic (SPV) system using the Z-source Inverter (ZSI), providing the necessary active power to mitigate the voltage sag/swell and power demand. ZSI offers step-down as well as step-up abilities, it makes the converters to operate in the conditions of shoot-through. Therefore, the application of ZSI-based DVR topology seems very promising. The compensating reference voltage is generated by the R-SOGI algorithm, which offers superior output under conditions for grid voltage irregularities, including voltage sag/swell and unbalanced and distorted utility grid voltages. In comparison to DVR based on the VSI voltage inverter (VSI), the response from ZSI-DVR to a reduction of voltage distortions and harmonics is investigated. An experimental SPV ZSI-DVR prototype is developed in the laboratory to check the effectiveness of the controller and is tested under balanced and unbalanced supply and dynamic load conditions.

Оптимизация технологии переработки медных руд Удоканского месторождения

The composition of the mineral raw materials of the Udokan copper deposit has been studied. It is established that the copper minerals antlerite and brochantite are represented both in the form of ordinary and crystal hydrate forms, the properties of which are reflected in the flotation process. Studies were carried out on sulfide, mixed and oxidized samples of ores from the Udokan deposit. A unified flotation scheme for processing such ores with the production of sulfide and mixed copper concentrate with subsequent hydro- and pyrometallurgical methods is recommended. The objects of research are sulfide, mixed and oxidized copper ores of the Udokan deposit. The subject of the study is the technology of processing copper ores. Research objectives: – study of the mineral, material, and chemical composition of copper ores of the Udokan deposit; – study of existing technologies for processing copper ores; – conducting laboratory experiments on sulfide, mixed and oxidized ore samples of the Udokan deposit; – recommendation of a unified enrichment scheme for all types of copper ores of the Udokan deposit. Research methods. The work was carried out on the basis of studying the available sources on the occurrence, composition and structure of copper ores of the Udokan deposit, methods of their processing. In the course of laboratory studies, a flotation method of mineral enrichment was used with the use of operations to stabilize the energy state of the dispersed system (with Eh control) and subsequent electrochemical treatment of the pulp. The authors emphasize that the recommended scheme for processing copper ores from the Udokan deposit will optimize the processing technology and increase the efficiency of mining this deposit. Hydro- and pyrometallurgical methods are the most optimal for processing the obtained sulfide and mixed concentrates

A method to generate context information sets from analysis results with a unified abstraction model based on an extension of data enrichment scheme

AbstractContext‐awareness techniques generally deal with steps for processing information that can be gathered from perspectives of objects in real‐world scenes in accordance with resolving heterogeneous devices and providing meaningful context information in recent computing domains such as Internet of Things, cloud computing, edge computing, and big data analysis. However, analysis applications are necessary to be improved in a way of cooperative approaches because they are independently executed far away from context‐aware systems. This means that the stages are applied to process the data or the derived results, are isolated. That leads difficulties of management and integration for other software modules. As a result, a computing paradigm called edge computing has been suggested to compromise such isolations. For processing context information, it is necessary to establish knowledge parts with validation processes against the isolations. In this paper, we suggest a method for processing datasets in a view of building knowledge parts. The suggested method uses an extensible data enrichment scheme, which represents the relations for the object. In the experiment section, applications of the proposed method are shown in one of the healthcare community centers, and the data abstraction with the analysis jobs can be processed for each real‐world object.

WITHDRAWN: Reduction in information loss due to isolated and dumb nodes using ant colony optimization for WSN

A Wireless Sensor Network is a collection of miniature devices known as Sensors that are intended for the purpose of sensing and sending data and information to the sink. They are used in various applications and in areas that require continuous monitoring such as military fields and medical cabins. The most critical issue or the important criteria regarding this WSN is energy conservation and lifetime maintenance. Although various clustering and routing mechanisms are proposed for WSNs, the problem remains unsolved and still it remains as a popular research topic. One such idea to improve the lifetime improvement is the effective usage of the isolated and dumb nodes in the network. Dumb nodes are different from the isolated ones. The nodes that continue sensing but unable to send the data is categorized as dumb nodes while the nodes that aren’t included into clusters are called isolated nodes. We have proposed a method known as RILoID-ACO (Ant Colony Optimization enriched scheme for Reduction in information loss in the occurrence of Dumb and isolated nodes) that enables the practice of mobile mule in collecting the data from isolated and dumb nodes by enhancing a trust parameter. Success probability of 100% and data loss protection over 19% is obtained as the result of simulation that shows the success of the proposed system.

Multy-cascade enrichment schemes for reprocessed uranium recycling

This paper deals with the problem of reprocessed uranium (RepU) enrichment in cascades of gas centrifuges with simultaneous fulfillment of requirements on concentrations of isotopes 232,234,236U. These harmful isotopes bred by nuclear chain reaction are responsible for an increase in radioactivity level and neutron poisoning of fresh nuclear fuel. The study examines the cascade schemes that aim at closing the nuclear fuel cycle by satisfying the formal condition of the complete uranium reclaim. The prospective VVER fuel cycle strategy of multiple uranium recycling is considered. Schemes under consideration are multi-cascade ones. Such configurations are necessary to fulfill both a series of requirements on concentrations of even-numbered isotopes in commercial low-enriched uranium and condition of ‘full return’ of uranium extracted from spent nuclear fuel from particular reactor to produce fresh fuel load for the same reactor. The research provides a basis for comparison between three various multi-cascade schemes designed to re-enrich RepU under mentioned above conditions. The unified metrics (related to ordinary cascade and normalized to LEU product) of natural uranium savings, separative work, and depleted uranium consumption and their derivative, we used. The calculations take into account the necessity of RepU dilution to compensate for the adverse effects of 232,234,236U isotopes. As the reference cascade scheme, a simple modification of a single triple-flow cascade for RepU enrichment was considered. It is demonstrated that some modern cascade schemes could provide repetitious recycling of uranium.

Towards improving finite element solutions automatically with enriched 2D solid elements

In this paper, we propose an automatic procedure to improve the accuracy of finite element solutions using enriched 2D solid finite elements (4-node quadrilateral and 3-node triangular elements). The enriched elements can improve solution accuracy without mesh refinement by adding cover functions to the displacement interpolation of the standard elements. The enrichment scheme is more effective when used adaptively for areas with insufficient accuracy rather than the entire model. For given meshes, an error for each node is estimated, and then proper degrees of cover functions are applied to the selected nodes. A new error estimation method and cover function selection scheme are devised for the proposed adaptive enrichment scheme. Herein, we demonstrate the proposed enrichment scheme through several 2D problems.

An extended finite element method formulation for modeling multi-phase boundary interactions in steady state heat conduction problems

The present paper proposes an XFEM formulation for heat transfer analysis of multi-phase materials with explicit treatment of boundary interactions. The existence of interfacial resistance at the boundaries of the material phases produces discontinuities in the temperature field and a standard finite element treatment would require complex domain discretizations and additional surface elements to capture the jumps of the temperature values. To overcome this problem, the proposed method captures these jumps by enriching the temperature field around the phase boundaries with appropriate discontinuous functions. Specifically, a new XFEM enrichment scheme is developed to address the issue of multiple-phase junctions, that is, areas where multiple boundaries with different properties intersect. This approach offers the advantage of bypassing the need for complex meshes required by the standard FE method and thus it significantly simplifies the analysis procedure. The elaborated methodology is first validated with existing results from the literature on heat conduction in polycrystalline materials. Then, a detailed model for heat conduction analysis of polymers reinforced with carbon-nanotubes is introduced, which takes into account the role of the interfacial resistance between different material phases. Even though the proposed method is demonstrated in heat conduction problems, it can be straightforwardly extended to other similar problem types, such us electrical conduction or equivalent mechanical properties.

Dynamic crack propagation analysis combined the stable scheme and continuous-discontinuous cellular automaton

A continuous-discontinuous cellular automaton method (CDCA) is developed for dynamic crack propagation. First, a separated time integral scheme is built, in which time difference is divided into two separated time steps: one balances the change of the geometric discretization caused by crack growing, and the other balances the dynamic loading. Second, an adaptive energy conservation strategy is proposed for the CDCA that includes the change in the degree of nodal freedom for the crack tip element, and a new strategy for the inheritance of the degrees of nodal freedom is proposed. This method retains the enrichment scheme for the discontinuity, and the Shepard interpolation method is employed to transform the variables’ values, so as to keeps the energy conservation caused by crack tip location change. Then, the enriched degree of nodal freedom values are easily passed from the crack tip enrichment to the penetrated enrichment and crack tip local coordinate system changing with crack growing. Third, a dynamic crack propagation criterion is developed, which can be used for tensile fractures and compression shear fractures. Based on those theories, a new cellular automaton model is built for dynamic crack propagation. Compared to the extended finite element method (XFEM), the calculation efficiency has been greatly improved, and several numerical examples are given to illustrate accuracy and efficiency of the present method.

CRISPR-Mediated Isogenic Cell-SELEX Approach for Generating Highly Specific Aptamers Against Native Membrane Proteins.

The generation of affinity reagents that bind native membrane proteins with high specificity remains challenging. Most in vitro selection paradigms utilize different cell types for positive and negative rounds of selection (where the positive selection is against a cell that expresses the desired membrane protein and the negative selection is against a cell that lacks the protein). However, this strategy can yield affinity reagents that bind unintended membrane proteins on the target cells. To address this issue, we developed a systematic evolution of ligands by exponential enrichment (SELEX) scheme that utilizes isogenic pairs of cells generated via CRISPR techniques. Using a Caco-2 epithelial cell line with constitutive Cas9 expression, we knocked out the SLC2A1 gene (encoding the GLUT1 glucose transporter) via lipofection with synthetic gRNAs. Cell-SELEX rounds were carried out against wild-type and GLUT1-null cells using a single-strand DNA (ssDNA) library. Next-generation sequencing (NGS) was used to quantify enrichment of prospective binders to the wild-type cells. 10 rounds of cell-SELEX were conducted via simultaneous exposure of ssDNA pools to wild-type and GLUT1-null Caco-2 cells under continuous perfusion. The top binders identified from NGS were validated by flow cytometry and immunostaining for their specificity to the GLUT1 receptor. Our data indicate that highly specific aptamers can be isolated with a SELEX strategy that utilizes isogenic cell lines. This approach may be broadly useful for generating affinity reagents that selectively bind to membrane proteins in their native conformations on the cell surface.

Magnetic-gravity separation in the simulation modeling paradigm

An interdisciplinary approach to the simulation of magnetic gravity separation is proposed. The approach is based on revealing the laws of motion of mineral particles taking into account their magnetic properties in a computational experiment and establishing the form of an empirical multidimensional function for calculating the deposition rate of aggregated ferromagnetic particles in a multiphase multi-speed process medium. Based on the results, a comparative assessment of the convergence of the obtained deposition kinetics parameters with respect to the practice of applying the classical Stokes formula is given. The possibility of interpreting the fractional separation characteristics of the magnetic-gravity separator using the error function is shown. A method for integrating the simulation model of magnetic-gravity separation into an analytical prototype of the technological enrichment scheme is considered, for which the basic principles of constructing technological schemes for mineral processing are presented and the principles of constructing their simulation models are formulated.