Cadmium levels of kidney from 10 different pig genetic lines in Vojvodina (northern Serbia)

Concentration of cadmium was investigated in the kidney of 480 pigs from 10 different genetic lines, produced in Vojvodina (northern Serbia). This element was determined by flame atomic absorption spectrometry after mineralisation by dry ashing. The genetic line of pigs had no influence on the cadmium levels of kidney (P > 0.05). The cadmium levels ranged from 0.168 to 1.160 mg/kg, with an average of 0.368 mg/kg. Only 1.9% of kidney slightly exceeded the maximum level set by EU and Serbian legislation.     

两步法快速复原噪声模糊图像

本文提出了一种两步复原法,以用于复原被脉冲噪声干扰的模糊图像。第一步,对离群点进行识别,即那些疑似被脉冲噪声损坏的像素,并将剩余的像素视为基本非离群点。第二步,基于非离群像素,利用变分法对图像进行去模糊和去噪声。实验结果显示,使用该方法复原后图像的峰值信噪比dB值较采用典型变分法有所提高。     

Susceptibility of an industrial α-lactalbumin concentrate to cross-linking by microbial transglutaminase

The susceptibility of an industrial α-lactalbumin concentrate to cross-linking with a microbial transglutaminase from Streptoverticillium mobaraense was investigated. At a protein concentration of 0.5% w v⁻¹, the maximum cross-linking was observed at 50°C, pH 5 and at 5 h of incubation time. Results from sodium dodecyl sulphate (SDS)-polyacrylamide gel electrophoresis showed that most of the monomeric form of α-lactalbumin was converted to polymers too large to move into the gel matrix. Addition of ethylenediamine tetraacetic acid or SDS prior to the incubation of protein–enzyme mixture, further enhanced the transglutaminase reaction with the industrial α-lactalbumin. Results from reverse phase chromatography indicated that cross-linking caused a broadening of the α-lactalbumin peak with little change in the average hydrophobicity of the protein. In contrast to the reported results on pure α-lactalbumin, the industrial α-lactalbumin concentrate showed considerable cross-linking with transglutaminase even without the reduction of the disulphide bonds. This difference was attributed to the partially unfolded secondary structures in the industrial α-lactalbumin concentrate.     

Effects of an afternoon nap on nighttime alertness and performance in long-haul drivers

The effects of an afternoon nap on alertness and psychomotor performance were assessed during a simulated night shift. After a night of partial sleep restriction, eight professional long-haul drivers either slept (nap condition) or engaged in sedentary activities (no-nap condition) from 14:00 to 17:00 h. Alertness and performance testing sessions were conducted at 12:00 (pre-nap baseline), 24:00, 02:30, 05:00 and 07:30 h, and followed 2-h runs in a driving simulator. In the nap condition, the subjects showed lower subjective sleepiness and fatigue, as measured by visual analog scales, and faster reaction times and less variability on psychomotor performance tasks. Electrophysiological indices of arousal during the driving runs also reflected the beneficial effects of the afternoon nap, with lower spectral activity in the theta (4–7.75 Hz), alpha (8–11.75 Hz) and fast theta-slow alpha (6–9.75 Hz) frequency bands of the electroencephalogram, indicating higher arousal levels. Thus, a 3-h napping opportunity ending at 17:00 h improved significantly several indices of alertness and performance measured 7–14 h later.     

Refinement of Actions in a Real-Time Process Algebra with a True Concurrency Model

In this paper, we develop techniques of action refinement in a real-time process algebra that allows urgent interactions to model timeout. Semantic counterpart is carried out in a real-time non-interleaving causality based setting, timed bundle event structures. We show that our refinement notions have the following nice properties: the observable behaviour of the refined system can be inferred compositionally from the observable behaviour of the original system and from the observable behaviour of the processes substituted for the actions; the timed extensions of observational pomset trace equivalence and observational history preserving bisimulation equivalence are both congruences under our refinement; and the syntactic and semantic refinements coincide up to the aforementioned equivalence relations with respect to a cpo-based denotational semantics.     

Formation of oxygen complexes in controlled atmosphere at surface of doped glassy carbon

The effects of boron and phosphorus incorporation in phenolic resin precursor to the oxidation resistance of glassy carbon have been studied. In order to reveal the nature and composition of the oxygen complexes formed at the surface of doped glassy carbon, under controlled atmosphere, the surface of the samples was cleaned under vacuum up to 1273 K. Specific functional groups, subsequently formed under dry CO₂ or O₂ atmosphere on the surface of boron-doped and phosphorus-doped glassy carbon samples, were examined using the temperature-programmed desorption method combined with mass spectrometric analysis. Characterization of surface properties of undoped and doped samples has shown that in the presence of either boron or phosphorus heteroatoms, a lower amount of oxygen complexes formed after CO₂ exposure, while, typically, higher amount of oxygen complexes formed after O₂ exposure. It has been concluded that the surface of undoped glassy carbon has a greater affinity towards CO₂, while in the presence of either boron or phosphorus heteroatoms, the glassy carbon surface affinity becomes greater towards O₂, under experimental conditions.     

New superhard material for drilling tools

The authors discuss physical-mechanical properties of a new thermostable polycrystalline diamond composite material and its potential use in rock-destruction tools for drilling wells in hard rock. The paper presents the results of investigation aimed at clarifying the effect of dimensions of inserts made of this new material on the drilling tool performance. An optimal size of inserts to be set in the bit face has been established which improves hard rock drilling efficiency in comparison to conventional tools.     

The use of EAF dust in cement composites: Assessment of environmental impact

Electric arc filter dust (EAF dust) is a waste by-product which occurs in the production of steel. Instead of being disposed of, it can be used in cement composites for civil engineering, and for balances in washing machines. To estimate the environmental impact of the use of EAF dust in cement composites leachability tests based on diffusion were performed using water and salt water as leaching agents. Compact and ground cement composites, and cement composites with addition of 1.5% of EAF dust by mass were studied. The concentrations of total Cr and Cr(VI) were determined in leachates over a time period of 175 days. At the end of the experiment the concentrations of some other metals were also determined in leachates. The results indicated that Cr in leachates was present almost solely in its hexavalent form. No leaching of Cr(VI) was observed in aqueous leachates from compact cement composites and compact cement composites to which different quantities of EAF dust have been added. In ground cement composites and in ground cement composites with addition of EAF dust, Cr(VI) was leached with water in very low concentrations up to 5 μg L⁻¹. Cr(VI) concentrations were higher in salt water leachates. In compact and ground cement composites with addition of EAF dust Cr(VI) concentrations were 40 and 100 μg L⁻¹, respectively. It was experimentally found that addition of EAF dust had almost no influence on leaching of Cr(VI) from cement composites. Leaching of Cr(VI) originated primarily from cement. Leaching of other metals from composites investigated did not represent an environmental burden. From the physico-mechanical and environmental aspects EAF dust can be used as a component in cement mixtures.     

Determination of selected pesticides in fruit juices by matrix solid-phase dispersion and liquid chromatography–tandem mass spectrometry

A rapid and sensitive liquid chromatography–tandem mass spectrometry method has been developed for the analysis of acephate, monocrotophos, carbendazim, acetamiprid, dimethoate, simazine, carbofuran, atrazine, diuron, DNOC (4,6-dinitro-o-cresol), malathion and tebufenozide in fruit juices. Extracts were obtained by matrix solid-phase dispersion using diatomaceous earth as dispersant and dichloromethane as eluent. Significant matrix effects observed for most of the pesticides tested were eliminated using matrix-matched standards. The quantification of the analytes was carried out using the most sensitive transition. The confirmation of residues detected in real samples was performed by repeated injection and acquiring additional transitions to that used for quantification. Recoveries were in the range 71–118%. Repeatability of the method, expressed as the relative standard deviation, was in general between 5–15%. Low limits of detection (0.01–0.94 ng ml⁻¹) and quantification (0.03–3.12 ng ml⁻¹) were readily achieved with this method for all tested pesticides.     

抗Cry1c蛋白兔单克隆抗体的制备和鉴定

通过原核质粒表达重组Cry1c晶体蛋白,将其纯化后作为特定抗原免疫兔子。经多抗血清效价的测定,细胞融合,杂交瘤细胞的筛选,构建重组载体等步骤获得抗Cry1c单克隆抗体。通过ELISA方法测定单克隆抗体相关特性,结果表明,Cry1c兔单克隆抗体效价超过3.2×104,其亲和常数为2.4×109L/mol,该单克隆抗体与Cry1Ac蛋白有微量交叉反应,与Cry1Ab蛋白无明显交叉反应。间接ELISA检测抗原Cry1c蛋白时,当包被量为400ng/mL时,判定为阳性。