Degradation of collagen in parchment under the influence of heat-induced oxidation: Preliminary study of changes at macroscopic,microscopic, and molecular levels

This paper examines the impact of heat-induced oxidation for new and historical parchment with the purpose of improving diagnostic tools for use in practical parchment conservation. Oxidation was generated by heat aging at 120°C in a dry oven for 24, 48, and 96 hours, respectively. The degradation was assessed on all samples at macrolevel by measuring color changes, at microlevel by measuring the shrinkage temperature as well as by performing a visual assessment of the fibers’ morphology and determining the amount of damaged fibers, and finally, at molecular level where amino acid analysis was used to reveal changes in the oxidized collagen. The study shows that the heat-induced oxidation leads to significant color changes, decrease in hydrothermal stability, as well as changes in the amino acid composition. Surprisingly, the results show that the historical parchment is more sensitive towards dry heat oxidation on a molecular level than is the new parchment. Furthermore, for the first time, we can show that physical damage reflected in the morphological characteristics of fibers can be attributed to oxidation by dry heat.     

论毛泽东关于共产党人"讲学习"的思想

毛泽东从中国革命和建设实践的需要出发,提出了共产党人必须"讲学习",要努力学习马克思主义理论,学习历史知识,学习经济,学习管理;"讲学习"必须坚持科学的态度和方法.     

Comparison of the force-, velocity-, and power-time curves recorded with a force plate and a linear velocity transducer

This study aimed to correlate, compare, and determine the reliability of force, velocity, and power values collected with a force plate (FP) and a linear transducer during loaded jumps. Twenty-three swimmers performed an incremental loading test at 25, 50, 75, and 100% of their own body weight on a FP. A linear velocity transducer (LVT) was attached to the bar to assess the peak and the mean values of force, velocity, and power. Both the peak variables (r = 0.94 – 0.99 for peak force, r = 0.83 – 0.91 for peak velocity, and r = 0.90–0.94 for peak power; p < 0.001) and the mean variables (r = 0.96–0.99 for mean force, r = 0.87–0.89 for mean velocity, and r = 0.93–0.96 for mean power; p < 0.001) were strongly correlated between both measurement tools. Differences in the shape of the force-, velocity-, and power-time curves were observed. The LVT data showed a steeper increase in these variables at the beginning of the movement, while the FP recorded larger values in the latter part. Peak values were more reliable than mean values. These results suggest that the LVT is a valid tool for the assessment of loaded squat jump.     

The characterization of four gene expression analysis in circulating tumor cells made by Multiplex-PCR from the AdnaTest kit on the lab-on-a-chip Agilent DNA 1000 platform

Introduction

Nowadays, on-a-chip capillary electrophoresis is a routine method for the detection of PCR fragments. The Agilent 2100 Bioanalyzer was one of the first commercial devices in this field. Our project was designed to study the characteristics of Agilent DNA 1000 kit in PCR fragment analysis as a part of circulating tumour cell (CTC) detection technique. Despite the common use of this kit a complex analysis of the results from a long-term project is still missing.

Materials and methods

A commercially available Agilent DNA 1000 kit was used as a final step in the CTC detection (AdnaTest) for the determination of the presence of PCR fragments generated by Multiplex PCR. Data from 30 prostate cancer patients obtained during two years of research were analyzed to determine the trueness and precision of the PCR fragment size determination. Additional experiments were performed to demonstrate the precision (repeatability, reproducibility) and robustness of PCR fragment concentration determination.

Results

The trueness and precision of the size determination was below 3% and 2% respectively. The repeatability of the concentration determination was below 15%. The difference in concentration determination increases when Multiplex-PCR/storage step is added between the two measurements of one sample.

Conclusions

The characteristics established in our study are in concordance with the manufacturer’s specifications established for a ladder as a sample. However, the concentration determination may vary depending on chip preparation, sample storage and concentration. The 15% variation of concentration determination repeatability was shown to be partly proportional and can be suppressed by proper normalization.Key words: lab-on-a-chip devices, capillary electrophoresis, multiplex PCR, circulating tumour cells, Agilent DNA 1000 kit     

英国公民教育现状及社交媒介与公民教育的关系——伊恩·戴维斯教授访谈录

为了更全面地了解英国公民教育现状以及当代世界公民教育的新问题,采访人与英国约克大学教育学教授、教育系副主任、教育与社会公正研究中心主任、教育研究所主任,著名的公民教育专家伊恩·戴维斯进行了访谈,对英国公民教育国家课程标准向品格教育的转向进行讨论,辨别什么是好的公民教育,探讨如何评估公民教育效果,思考社交媒介等新技术与公民教育的关系。在访谈的过程中,比较了中英两国的教育实践,总结了部分公民教育经验。     

A Review of the Research on Internet Addiction

Research indicates that maladaptive patterns of Internet use constitute behavioral addiction. This article explores the research on the social effects of Internet addiction. There are four major sections. The Introduction section overviews the field and introduces definitions, terminology, and assessments. The second section reviews research findings and focuses on several key factors related to Internet addiction, including Internet use and time, identifiable problems, gender differences, psychosocial variables, and computer attitudes. The third section considers the addictive potential of the Internet in terms of the Internet, its users, and the interaction of the two. The fourth section addresses current and projected treatments of Internet addiction, suggests future research agendas, and provides implications for educational psychologists.     

Europäisches Bewusstsein: Zur Definition Eines Vielschichtigen Begriffes und Seiner Bildungstheoretischen Bedeutung

EUROPEAN CONSCIOUSNESS: TOWARDS DEFINING A COMPLEX CONCEPT AND ITS EDUCATIONAL SIGNIFICANCE – The present study aims at a definition of ‘European consciousness’. In particular, it draws on Henri Tajfel’s theory of social identity as well as Roland Wakenhut’s and Jutta Gallenmüller’s moral determination of national consciousness. European consciousness is then defined as a sense of belonging which, depending on certain identification structures and social perspectives, can take such distinct forms of moral consciousness as ‘Eurocentrism’, ‘European patriotism’, or ‘reflective European consciousness’. Making reference to Wolfgang Klafki’s notion of general education, it is finally argued that the emancipatory contribution of schooling to greater European integration consists in mediating precisely this last way of thinking.     

中国传统“德”“法”概念演变及当代意义

中国传统“法”“德”涵义不同于现代的“法”“德”涵义,中国古代“法”“德”概念的演变是中国社会变革的反映,是古代中国人生存状态的反映。     

CaO+SiO2+Al2O3+MgO+FeO 五元渣系中FeO 活度的研究

Activities of FeO in CaO-SiO2-Al2O3-MgO-FeO slags were determined at 1673 K by electrochemical of the solid electrolyte cell： Mo [Mo＋MoOu[ZrO2（MgO）[Fe＋（CaO-SiO2-Al2O3-MgO-FeO）＋Ag[Fe. The influences of slag compositions and basicity on FeO activities were analyzed. The results reveal that, for slags of fixed （%CaO）/（%SiO2） ratio, MgO and Al2O3 content, there was an increase of FeO activities with increase of FeO content. For slags with constant {（%CaO）＋ （%MgO）}/（%SiO2） ratio, fixed FeO and A1203 content, FeO activities decreased when MgO content increased from 5% to 10%, and increased with the increase of MgO content when it was over 10%. The FeO activities increased when （%CaO）/（%SiO2） ratio changed from 1.03 to 1.30 in the slags of constant MgO, FeO and Al2O3 content.