Biotechnology embraces various physical and chemical phenomena toward advancement of health diagnostics. Toward such advancement, detection of toxins plays an important role. Toxins produce severe health impacts on consumption with high mortality associated in acute cases. The most prominent route of infection and intoxication is through food matrices. Therefore, rapid detection of toxins at low concentrations is the need of modern diagnostics. Lateral flow immunoassays are one of the emergent and popularly used rapid detection technology developed for detecting various kinds of analytes. This review thus focuses on recent advancements in lateral flow immunoassays for detecting different toxins in agricultural food. Appropriate emphasis was given on how the labels, recognition elements, or detection strategy has laid an impact on improvement in immunochromatographic assays for toxins. The paper also discusses the gradual change in sensitivities and specificities of assays in accordance with the method of food processing used. The review concludes with the major challenges faced by this technology and provides an outlook and insight of ideas to improve it in the future. 相似文献
Nanostructured thin films of undoped and Ag-doped cuprous oxide were deposited on indium tin oxide-coated glass substrate using simple spray pyrolysis method for their use as photocathode in photoelectrochemical (PEC) cell for solar energy based water splitting. Combination of experiments and first-principles density functional theory based calculations was used to determine and understand the effect of Ag substitution on electronic structure and PEC performance. Thin films were characterized using XRD, FE-SEM, UV–Vis spectroscopy and PEC measurements. The results of DFT calculations show that the top of valence band and bottom of conduction band of undoped Cu2O lie at Г point of brillouin zone, respectively, suggesting that pure Cu2O is a direct band gap material. Minimal changes appear in the band gap and band gap energies in the Ag-doped Cu2O system, keeping it still a direct band gap material. A defect band appearance can be seen between ?4 and ?5 eV in the valence band consisting mainly of Ag 4d states and can be explained by a stronger interaction between the Ag 4d and O 2p, due to the larger Ag size. Ag-doped samples exhibit improved conductivity and fourfold increase in photocurrent density with respect to undoped samples. 相似文献
The 2013 Nobel Prize in Chemistry highlights how crucial computer simulations have become for many scientific and engineering fields. Nowadays, scientific progress is not only driven by the interplay of new experimental measurements and increasingly sophisticated theoretical frameworks, but also by an incredible toolbox of complex computational models meeting ubiquitously available computing power and data storage facilities. Quantum mechanical (QM) calculations can be condensed into molecular mechanics (MM) force fields and coupled QM/MM calculations can derive atomic and molecular properties of biomolecular or materials science systems with high accuracy. Pure MM simulations driven by Monte Carlo or molecular dynamics algorithms are widely applied in biological chemistry/physics and can investigate large biomolecular systems, such as proteins, DNA, or RNA. One coarse-grained class of these models, native-structure-based or Go models, are based on energy landscape theory and the principle of minimal frustration. Herein, an ensemble of converging pathways guide protein folding on a funnel-like shape of the entire energy landscape towards the native state. Simulations based on these ideas have been tremendously successful in explaining protein folding and function. Their history and recent application highlights are reviewed. 相似文献
Predicting the macroscopic and microscopic mechanical response of metals and alloys subjected to complex loading conditions necessarily requires a synergistic combination of multiscale material models and characterization techniques. This article focuses on the use of a multiscale approach to study the difference between intergranular lattice strain evolution for various grain families measured during in situ neutron diffraction on dog bone and cruciform 316L samples. At the macroscale, finite element simulations capture the complex coupling between applied forces and gauge stresses in cruciform geometries. The predicted gauge stresses are used as macroscopic boundary conditions to drive a mesoscale full-field elasto-viscoplastic fast Fourier transform crystal plasticity model. The results highlight the role of grain neighborhood on the intergranular strain evolution under uniaxial and equibiaxial loading. 相似文献
Stochastic simulations are becoming increasingly important in numerous engineering applications. The solution to the governing
equations are complicated due to the high-dimensional spaces and the presence of randomness. In this paper we present
libMoM
(), a software library to solve various types of Stochastic Differential Equations (SDE) as well as estimate statistical distributions
from the moments. The library provides a suite of tools to solve various SDEs using the method of moments (MoM) as well as
estimate statistical distributions from the moments using moment matching algorithms. For a large class of problems, MoM provide
efficient solutions compared with other stochastic simulation techniques such as Monte Carlo (MC). In the physical sciences,
the moments of the distribution are usually the primary quantities of interest. The library enables the solution of moment
equations derived from a variety of SDEs, with closure using non-standard Gaussian quadrature. In engineering risk assessment
and decision making, statistical distributions are required. The library implements tools for fitting the Generalized Lambda
Distribution (GLD) with the given moments. The objectives of this paper are (1) to briefly outline the theory behind moment
methods for solving SDEs/estimation of statistical distributions; (2) describe the organization of the software and user interfaces;
(3) discuss use of standard software engineering tools for regression testing, aid collaboration, distribution and further
development. A number of representative examples of the use of
libMoM
in various engineering applications are presented and future areas of research are discussed. 相似文献
A highly regioselective synthesis of pyrido[2,1‐a]isoindolium salts from 2‐arylpyridines and two equivalents of electron‐deficient alkenes catalyzed by rhodium is demonstrated. The reaction was carried out in aqueous medium at 110 °C using inexpensive oxygen as oxidant. Reverse aza‐Michael addition of the isoindolium salt occurs when the salt was treated with base to give a β‐disubstituted alkene product. A reaction mechanism involving an ortho C–H olefination of 2‐arylpyridine by alkene, intramolecular aza‐Michael addition, deprotonation at the β‐carbon of the alkene fragment followed by another Michael addition to give the final product is proposed.
An operationally simple and efficient, one‐pot, two‐step methodology has been developed for the assembly of medicinally important imidazo[1,5‐a]quinoxalines. The protocol involves the multicomponent reaction of aryl aldehydes, ortho‐N‐Boc‐phenylenediamines and azidochalcones in the presence of erbium triflate as a Lewis acid catalyst, followed by deprotection–cyclization with 10% trifluoroacetic acid, furnishing the desired compounds in moderate to good yields. By virtue of their convergence, two aromatic rings and four new bonds are generated during the course of this reaction protocol. The structure of one of the compounds was proved by X‐ray crystallography.
ABSTRACTWe have investigated alpha (α) relaxation process and its temperature evolution in electrical double layer (EDL) around neutrophil gelatinase-associated lipocalin (NGAL), anti-lipocalin2 (anti-LCN-2) and their conjugate in phosphate buffer. The dielectric permittivity (20 Hz to 1 MHz) of α-relaxation process for LCN-2 and anti-LCN-2 shows variation with temperature. This happens due to unfolding of various microstates of protein at measured temperature intervals. The DSC thermograms of LCN-2, anti-LCN-2 and their conjugate predict that the multiple unfolding domains are parallel to the shifts in real dielectric permittivity at a particular temperature. 相似文献
This study investigated the efficacy of 3 GRAS‐status, plant‐derived antimicrobials (PDAs), trans‐cinnamaldehyde (TC), carvacrol (CR), and β‐resorcylic acid (BR) applied as an antimicrobial wash for killing Escherichia coli O157:H7 on apples. “Red delicious” apples inoculated with a 5 strain mixture of E. coli O157:H7 were subjected to washing in sterile deionized water containing 0% PDA (control), 0.15% TC, 0.35% TC, 0.15% CR, 0.30% CR, 0.5% BR, or 1% BR for 1, 3, and 5 min at 23 °C in the presence and absence of 1% soil, and surviving pathogen populations on apples were enumerated at each specified time. All PDAs were more effective in reducing E. coli O157:H7 compared to the water wash treatment (P < 0.05) and reduced the pathogen by 4‐ to 5‐log CFU/apple in 5 min. Chlorine (1%) was the most effective treatment reducing the pathogen on apples to undetectable levels in 1 min (P < 0.05). Moreover, the antimicrobial effect of CR and BR was not affected by the presence of soil, whereas the efficacy of TC and BR was decreased in the presence of soil. Further, no bacteria were detected in the wash solution containing CR and BR; however, E. coli O157:H7 was recovered in the control wash water and treatment solutions containing TC and chlorine, in the presence of 1% soil (P < 0.05). Results suggest that the aforementioned PDAs, especially CR and BR could be used effectively to kill E. coli O157:H7 on apples when used as a wash treatment. Studies on the sensory and quality characteristics of apples treated with PDAs are needed before recommending their usage. 相似文献