Assessment of the bioavailability of toxic and non-toxic arsenic species in seafood samples

Bioavailability of total arsenic, toxic (arsenite, As(III); and arsenate, As(V)), and non-toxic (monomethylarsonic acid, MA; dimethylarsonic acid, DMA; arsenobetaine, AB; and arsenocholine, AC) arsenic species has been assessed in different raw seafood samples (white fish, cold water fish and molluscs) by using an in vitro model that combines simulated gastric and intestinal digestion/dialysis methods. Correlations between arsenic species bioavailability and seafood nutrient contents (fat and protein) have also been established. Total arsenic content in seafood samples, and dialyzable and non-dialyzable fractions, were analyzed by inductively coupled plasma – mass spectrometry (ICP–MS) after a microwave-assisted acid digestion treatment. The determination of the different arsenic species concentrations in the samples (after an optimised matrix solid phase dispersion (MSPD) approach) and in the dialyzable fraction was done by high performance liquid chromatography (HPLC) coupled to ICP-MS as a selective detector. Accuracy of the procedure (total arsenic determination) was assessed by analyzing DORM-2 and BCR-627 certified reference materials. The accuracy of the in vitro procedure was established through a mass-balance study. After statistical evaluation (95% confidence interval), good accuracy of the whole in vitro process, for total arsenic and for arsenic speciation, was observed. High dialyzability percentages for total arsenic and for arsenic species were found (i.e. from 84.6 ± 1.7% to 106 ± 2.6%). Bioavailability of arsenic exhibits a negative correlation with the fat content of the seafood. However, no correlation was observed between the bioavailable fraction of total arsenic and arsenic species and the protein content of the seafood studied.     

移动对象无冗余周期模式发现算法

技术的发展进步和需求的多样性,产生了大量的数据,数据背后隐含模式的发现对问题的深入研究起到关键性的作用.为了挖掘移动对象的周期运动模式,提出了一种无冗余周期模式(Non-redundant period patterns,NRPP)发现算法.为解决噪声因素的影响,在现有方法基础上,引入相似性因子,删减冗余周期模式,使挖掘出的模式精简、准确.算法为不同模式设置不同阈值,不但解决了稀有项问题和组合爆炸问题,而且也使得挖掘效率更高效.采用公开移动对象数据实验,结果表明算法能高效挖掘出移动对象的周期模式.     

盘锦市中心医院

项目概述 盘锦市中心医院是集医疗、教学、科研、环保，康复、急救“六位一体“的三级甲等综合性医院，功能定位是向全市两县、两区提供高水平医疗卫生服务，     

Increases in nitrogen use efficiency decrease nitrous oxide emissions but can penalize yield in sugarcane

Nutrient Cycling in Agroecosystems - Nitrogen (N) fertilization strategies focused on increasing nitrogen use efficiency (NUE) and decreasing nitrous oxide (N2O) emissions are important for...     

Microwave-assisted synthesis and characterization of bioactive chitosan scaffolds doped with Au nanoparticles for mesenchymal stem cells culture

In this work we present a novel strategy for chitosan-based scaffolds. Chitosan is a versatile biopolymer obtained from waste biomass known of its favorable biological properties. Thus it can replace other polymers in the preparation of bioactive scaffolds. To increase its durability chitosan can be crosslinked into form of the hydrogel yet application of toxic crosslinkers may lead to loss of biocompability. Mesenchymal stem cells can be used in cell therapy for advanced wound treatment. However their culture requires special biomaterials application. In this article a novel microwave-assisted synthesis method for bioactive chitosan scaffolds is presented.     

Effects of acid treatment on adhesive performance of encapsulated aluminium pigments on plastic sheets

In this study, aluminium pigments were encapsulated with hydroxyl group‐containing acrylic resin after surface acid treatment to enhance their adhesive performance in the paint film. The removal efficiency of fatty acid on surface of aluminium particles was studied by means of thermogravimetric analysis and the effect of acid treatment on adhesive performance of aluminium pigments encapsulated with hydroxyl group‐containing acrylic resin in the paint film was investigated by pulling‐off tests. It was found that fatty acid on surface of aluminium particles was removed efficiently by acid ethanol solution, and then hydroxyl group‐containing acrylic resin can be encapsulated onto the surface of the aluminium particles by chemisorptions. The encapsulated aluminium pigments have excellent adhesive performance in the paint film. © 2011 Canadian Society for Chemical Engineering     

Bio-hydrogen production enhancement by co-cultivating Rhodopseudomonas palustris WP3-5 and Anabaena sp. CH3

Photobiological H₂ production is a promising method for renewable energy development. An innovative system that co-cultivating Rhodopseudomonas palustris WP3-5 and Anabaena sp. CH3 was carried out to estimate the effect of co-cultivation on H₂ production enhancement. H₂ production prolongation and enhancement were observed due to the light and metabolic compatibility of these two strains. Co-culture system served by acetate and fructose as carbon source can accumulate H₂ in 140.8 mL, almost double than the sum of individuals. Moreover, the enhancement of H₂ production was significantly affected by the mixed ratio of two strains. The mixed ratio (WP3-5:CH3) of 1:2 showed a highest H₂ production rate in 44.8 mL-H₂/L-culture/h, and both 2:1 and 1:2 exhibited a relatively high substrate conversion efficiency during the latest period of cultivation, whereas the mixed ratio of 1:1 and 3:1 only revealed a prolongation in H₂ production due to metabolic compatibility of two strains.     

从文学变异学角度重新审视翻译等值研究

翻译＂等值＂或等效问题是译学界长期争论的焦点问题。语言学派和文化学派分别从语言学角度和文化视角对此提出了各自的见解。比较文学变异学将翻译中的变异作为研究支点,＂跨语际变异研究＂成为译学研究的新范式,通过研究不同国家之间文学现象交流的变异状态,探究并揭示文学变异现象的内在规律性,对翻译研究有重要的启示意义。     

Thermal degradation characteristic of Tetra Pak panel boards under inert atmosphere

hermal degradation characteristics of Tetra Pak panel boards (TPPB) can be useful to improve usage of such panels as an alternative to wood-based products such as plywood, fiberboard, and particleboard. In the study, samples from the TPBBs manufactured from waste Tetra Pak packages (WTPP) were heated in a nitrogen atmosphere at different heating rates (10, 15 and 20 °C/min) using a thermal analysis system. The Coats-Redfern kinetic model was applied to calculate kinetic parameters. The degradation rate equations were then established. In addition, the kinetic compensation effect (KCE) was used to correlate the pre-exponential factor (k _o ) with activation energy (E _a ) and the existence of the KCE was accepted. TG-FT/IR analyses were applied to the TPPB degradation and then the FT-IR stack plot was used to analyze gas products (CO₂, CH₄, HCOOH, and CH₃OH). Infrared vibrational frequencies and the micro, crystal structure of the TPPBs were investigated by Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscope (SEM) and X-Ray diffraction analysis (XRD), respectively.