Nonenzymatic detection of bacterial genomic DNA using the bio bar code assay

The detection of bacterial genomic DNA through a nonenzymatic nanomaterials-based amplification method, the bio bar code assay, is reported. The assay utilizes oligonucleotide-functionalized magnetic microparticles to capture the target of interest from the sample. A critical step in the new assay involves the use of blocking oligonucleotides during heat denaturation of the double-stranded DNA. These blockers bind to specific regions of the target DNA upon cooling and prevent the duplex DNA from rehybridizing, which allows the particle probes to bind. Following target isolation using the magnetic particles, oligonucleotide-functionalized gold nanoparticles act as target recognition agents. The oligonucleotides on the nanoparticle (bar codes) act as amplification surrogates. The bar codes are then detected using the Scanometric method. The limit of detection for this assay was determined to be 2.5 fM, and this is the first demonstration of a bar code-type assay for the detection of double-stranded, genomic DNA.     

条码质量检测方法

介绍传统条码质量检测和综合分析等方法,对各种检测方法的优缺点作了一定比较,并提出条码印制质量控制的基本方法。     

An analysis of the threading bar method of magnetic particle flaw detection

A theoretical analysis is presented which predicts that the magnetic field induced in a tubular component by a threading bar will be independent of its posiition. This is demonstrated in practice and the implications it has for standard testing procedures are discussed.     

A modified method of determining the thermal constants of nonmetallic materials

We describe a method and the experimental set-up for a comprehensive determination of thermal constants. The method is applied to reinforced composite materials.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 33, No. 6, pp. 1052–1057, December, 1977.     

A domain-extension method for quantitative detection of cavities by infrared scanning

A domain-extension method for quantitative detection of irregular-shape cavities inside irregular-shape bodies is presented. An auxiliary problem is introduced in the solution of the cavities. In the auxiliary problem, the original body domain at the cavity side is extended so that the original cavity walls become interior points. The position of the cavities can then be found by solving the temperature field in the extended domain and matching the temperatures and heat fluxes at the interior points to the conditions imposed on the cavities. A boundary-element method is used for the solution of the auxiliary problem, and by means of four examples, the accuracy of the domain extension method is established. The paper provides the details for the numerical solution of the cavities. Limitation of the method in the detection of multiple cavities is also explored. The domain-extension method has shown to be highly effective in quantitative detection of cavities in single-cavity bodies.     

一种新型的碎石料检测统计方法

为提高工业设备中石料级配的效率和经济性,文章提出了采用图像处理方法检测混合石料中大小石比例的思路,用于调节连续投料设备的石料配比。文章在总结碎石图像基本特征的基础上,提出一种基于边缘检测、边缘生长和倾侧光照的图像处理方法,实现了碎石料的边界分割与特征参数估计。此技术有望替代传统的碎石筛分方法,从而提高工业设备的性能,降低石料级配的成本。     

Dielectric and microstructural properties of sintered BaTiO3 ceramics prepared from different TiO2 raw materials

BaTiO₃ ceramics, sintered from powders previously synthesized using TiO₂ of different characteristics, have been studied. The microstructural development depended on the crystalline nature and impurity types and levels, when the same sintering schedules were applied. Anatase leads to BaTiO₃ powders which showed a controlled grain growth after sintering. Rutile with very low impurity levels gave materials in which a non-uniform grain growth was promoted. Dielectric constant and loss tangent were measured and correlated with the density and microstructure. From these correlations, it seems that the raw materials' nature has a greater effect on the dielectric properties that the sintering schedule of a given material.     

An electrochemical method for making enzyme microsensors. Application to the detection of dopamine and glutamate

A novel method of microbiosensor fabrication is described. It is based on the electrochemical polymerization of an enzyme-amphiphilic pyrroleammonium solution on the surface of a microelectrode in the absence of supporting electrolyte. By trapping glutamate oxidase (GMO) or polyphenol oxidase (PPO) in such polypyrrole films, we made microbiosensors for the amperometric determination of glutamate or dopamine, respectively. The response of the GMO microelectrode to glutamate was based on the amperometric detection of the enzymically generated hydrogen peroxide at 0.6 V vs SCE. The detection limit and sensitivity of this microbiosensor were 1 μM and 32 mA M(-1) cm(-2), respectively. The response of the PPO microelectrode to dopamine was based on the amperometric detection of the enzymically generated quinoid product at -0.2 V. The calibration range for dopamine measurement was 5 × 10(-8)-8 × 10(-5) M and the detection limit and sensitivity were 5 × 10(-8) M and 59 mA M(-1) cm(-2), respectively.     

An extended element free Galerkin method for fracture analysis of functionally graded materials

An extended element free Galerkin method (XEFGM) has been adopted for fracture analysis of functionally graded materials (FGMs). Orthotropic enrichments functions are used along with the sub-triangle technique for enhancing the Gauss quadrature accuracy near the crack, and the incompatible interaction integral method is employed to calculate the stress intensity factors. Numerical simulations have proved that XEFGM provides more accurate results by less number of nodes (DOFs) in comparison with the unenriched EFGM and other conventional methods for several FGM problems with different crack locations and loadings. The results have been compared with the reference results, showing the reliability, stability, and efficiency of present XEFGM.

Received 9 June 2014 Accepted 17 September 2014.     

A simple and novel method for the quantitative detection of 5-hydroxymethylcytosine using carbon nanotube field-effect transistors

5-hydroxymethylcytosine (5-hmC) is an important epigenetic derivative of cytosine and quantitative detection of 5-hmC could be used as a reliable biomarker for a variety of human diseases. Current technologies used in 5-hmC detection are complicated and time/cost inefficient. In this work, we report the first application of antibody-functionalized carbon nanotube field-effect transistors (CNT-FETs) in quantitative detection of 5-hmC from mouse tissues. This method achieves facile and ultra-sensitive 5-hmC detection based on electrical performance device and avoids complicated processing for DNA samples. The 5-hmC content percentages of normal mouse cerebrum, cerebellum, spleen, lung, liver, and heart samples presented in the genomic DNA were measured as 0.653, 0.573, 0.002, 0.020, 0.076, and 0.009, respectively, which is consistent with previous reports. This technology could be developed into facile routine 5-hmC monitoring devices for clinic human disease diagnoses.

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Scattering and absorption of turbid materials determined from reflection measurements. 2: measuring method and calibration

A new experimental method has been developed to determine the scattering and absorption characteristics of a turbid material. Existing methods usually require transmission and reflection measurements carried out on a thin slab of the material under study; this method is based on reflection measurements carried out on bulk material. This will be of great advantage in many applications. This paper describes the measuring system and indicates the area of application of the method. Calibration measurements have been carried out to substantiate the approach.     

Effect of raw materials on emissions of polychlorinated dibenzo-p-dioxins and dibenzofurans from the stack flue gases of secondary aluminum smelters

The present study was undertaken to investigate the effect of raw materials on PCDD/F emission from secondary aluminum smelters (ALS). Four plants each of aluminum ingot smelters (over 50% ingot) and secondary ALS (over 70% waste or recycled aluminum) were selected and the results compared. The secondary ALS yield much higher PCDD/Fs than the aluminum ingot smelters, or 7.94-22.76ng/Nm(3) versus 0.57-2.67ng/Nm(3), due to the large percentage of waste or recycled aluminum used. As for air pollution control devices (APCDs), the wet scrubber system in one of the aluminum ingot smelters exhibits an adverse effect on PCDD/F removal, due to the continuous recycle of the contaminated water through the scrubber system. Another ingot plant equipped with cartridge filter, there is a significant reduction in PCDD/F TEQ (52%). The powdered activated carbon injection at 2kg/h (110mg/Nm(3)) in one ALS reduces 70% of the total PCDD/Fs. The average emission factor of four secondary ALS is much higher than that of aluminum ingot smelters, or 20-fold higher based on either raw materials or product. Consequently, more attention should be paid to the emission reduction of PCDD/Fs from the secondary ALS, including installation of a secondary burner, additional APCDs and the pre-cleaning of raw materials.     

An improved torsional method for determining the fracture toughness of stiff materials and of adhesive joints

A simple modification is described of the Outwater torsion test method for determining the fracture energy of stiff materials and of adhesive joints. It permits large torsions to be applied and the corresponding torque to be simultaneously monitored. The modified test method can be used with specimens of simple rectangular shape and having a wide range of stiffness. As an example, the fracture energy is determined for molded rectangular bars of polystyrene having a wide range of thickness and of width.

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Résumé On propose une modification simple de la méthode d'essai en torsion de Outwater en vue de déterminer l'énergie de rupture dans des matériaux raides et dans des joints collés.Cette amélioration permet d'appliquer des grandes torsions et le couple correspondant peut être simultanément enregistré. La méthode modifiée peut être utilisée sur des éprouvettes de forme rectangulaire simple, et présentant une large gamme de rigidité.A titre d'exemple, on détermine l'énergie de rupture des barreaux rectangulaires en polystyrène moulé, d'épaisseur et de largeur très variables.

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On leave of absence from The University of Akron, Akron, Ohio for the period: January–May, 1984.     

An evaluation of arsenic release from monolithic solids using a modified semi-dynamic leaching test

Quicklime and quicklime-fly ash-based stabilization/solidification (S/S) effectiveness was evaluated by performing semi-dynamic leaching tests (American Nuclear Society 16.1). Artificial soil samples, contaminated with arsenic trioxide (As2O3) as well as field soil samples contaminated with arsenic (As) were tested. The artificial soils were prepared by mixing amounts of kaolinite or montmorillonite with fine quartz sand. The S/S effectiveness was evaluated by measuring effective diffusion coefficients (De) and leachability indices (LX). Treatment was most effective in kaolinite-based artificial soils treated with quicklime and in quicklime-fly ash treated field soils. The experimental results indicate that De values were lowered as a result of S/S treatment. Upon treatment LX values were higher than 9, suggesting that S/S treated soils are acceptable for "controlled utilization". Based on a model developed by de Groot and van der Sloot [G.J. de Groot, H.A. van der Sloot, in: T.M. Gilliam, C.C. Wiles (Eds.), Stabilization and Solidification of Hazardous, Radioactive, and Mixed Wastes, vol. 2, ASTM STP 1123, ASTM, PA, 1992, p. 149], the leaching mechanism for all of the treated soils was found to be controlled by diffusion. The effect of soluble silica (Si) on As leachability was also evaluated. When soluble Si concentration was less than 1 ppm, As leachability was the lowest. The controlling mechanism of As immobilization whether sorption, precipitation, or inclusion was also evaluated. It was determined that precipitation was the dominant mechanism.     

Further investigation on the dynamic compressive strength enhancement of concrete-like materials based on split Hopkinson pressure bar tests. Part I: Experiments

Effects of the inertia-induced radial confinement on the dynamic increase factor (DIF) of a mortar specimen are investigated in split Hopkinson pressure bar (SHPB) tests. It is shown that axial strain acceleration is unavoidable in SHPB tests on brittle samples at high strain-rates although it can be reduced by the application of a wave shaper. By introducing proper measures of the strain-rate and axial strain acceleration, their correlations are established. In order to demonstrate the influence of inertia-induced confinement on the dynamic compressive strength of concrete-like materials, tubular mortar specimens are used to reduce the inertia-induced radial confinement in SHPB tests. It is shown that the DIF measured by SHPB tests on tubular specimens is lower than the DIF measured by SHPB tests on solid specimens. This paper offers experimental support for a previous publication [Li QM, Meng H. About the dynamic strength enhancement of concrete-like materials in a split Hopkinson pressure bar test. Int J Solids Struct 2003; 40:343–360.], which claimed that inertia-induced radial confinement makes a large contribution to the dynamic compressive strength enhancement of concrete-like materials when the strain-rate is greater than a critical transition strain-rate between 10¹ and 10² s⁻¹. It is concluded that DIF formulae for concrete-like materials measured by split Hopkinson pressure bar tests need to be corrected if they are going to be used as the unconfined uniaxial compressive strength in the design and numerical modelling of structures made from concrete-like materials to resist impact and blast loads.     

复杂背景下多目标提取的高灵敏度方法

对电视经纬仪拍摄到的飞行小目标图像进行了归一化高斯模板相关。传统的模板相关方法不能将真假目标集合充分分离,导致真目标的漏检或引入虚假目标。基于模板相关的高斯函数拟合方法(Gaussian Function Fitting Method, GFFM),对模板相关所得到的目标集(含有真目标和假目标)中的每一个元素进行高斯函数拟合,并引入了一个更为灵敏的检验量—高斯函数拟合误差,可以将真假目标集合明显区分开,减小阈值确定的难度。实验表明:当相关系数阈值rth=0.8时,传统模板相关方法漏检率20%,虚警率40%;而GFFM方法则检出了所有真目标,且无虚假目标。     

Magnetostrictive properties of epoxy resins modified with Terfenol-D particles for detection of internal stress in CFRP. Part 2: evaluation of stress detection

The mechanical performance of carbon fibre reinforced polymers is predominantly limited by internal stress induced by resin shrinkage of the polymer matrix. Terfenol-D particles are investigated as internal sensors to detect the stress situation on a non-destructive way. Part 1 of the article describes the preparation and characterization of the samples used in the investigation of the sensory effect (Kubicka et al. J Mater Sci 47:5752–5759, 2012). Part 2 presents the results of the evaluation of the stress detection. A fundamental discussion is given how these magnetostrictive particles act as stress sensors in epoxy resins using the Villari effect. Analysing this effect in terms of particle content, particle size and particle distribution the most promising parameters are identified. Obviously the higher the particle content (20 wt%) and the smaller the particle size (<20 μm) combined with a strong homogeneous particle distribution the higher the magnetic flux density changes, in case of tensile loads. These corresponding stress situations are quantified by a Hall probe. Interestingly, the magnetic flux density changes (?B) can be significantly increased by a pre-magnetization step of the samples, allowing a more sensitive detection of the Villari effect.     

Determination of quantitative characteristics in the morphology of complexes in an electrocardiogram. Integral method of analysis

An integral method of electrocardiogram analysis is created on the basis of a proposed energy model of heart operation according to the sequence of cardiocycle areas (S _R -interval patterns). A technique is presented for measuring the coordinates of the R-wave peak and formation of interval patterns with parameters R, RR, S _R and relative parameters. Comparative correlation and spectral analysis are provided for five proposed interval patterns of two groups of healthy and sick people. It is shown that an attempt to retain the bonded energy of complex morphology leads to an adequate change in complex amplitude, size of intervals and segments.