A novel and sensitive colorimetric detection of PABA by asymmetrically functionalized TA-AuNPs-PEG-FITC based on oriented aggregation

A colorimetric assay based on the oriented TA-AuNPs-PEG-FITC for rapid and sensitive PABA detection was proposed. Initially, the negatively charged TA modified on the surface of AuNPs enabled rapid binding to PABA due to the electrostatic interaction and hydrogen bond, resulting in a visible color change. However, particles were aggregated in a non-oriented way, leading to an unstable testing system which failed to realize the accurate quantification. Thus, the asymmetrically functionalized TA-AuNPs-PEG-FITC were prepared, in which the stabilizer agent of HS-PEG-FITC was attached to the specific sites on the surface of TA-AuNPs. Such a way of modification resulted in an oriented aggregation manner, the addition of PABA induced the formation of oligomers. Moreover, the introduction of FITC group acted as fluorescent marker, providing a simple, fast and quantitative method for characterization of PEG chain. The molar ratio between TA-AuNPs and modified PEG-FITC was further determined. A linear regression was established in a wide range from 10 μM to 1 mM with the LOD of 6.9 μM. Finally, the sensor was successfully applied in the health food. This was the first example in which TA-AuNPs-PEG-FITC were fabricated for colorimetric detection of PABA, and an indirect method based on fluorescence marker was well used to quantify the content of PEG chain.     

Determinant factors of individuals’ decision to emigrate in rural Spain: The role of ICT-based public policies

Depopulation is a dramatic problem in rural inland Spain. The present study draws on a survey administered to inhabitants of rural areas to analyse the factors influencing the decision to emigrate to larger centres of population, with a special focus on the impact of ICT-based public policies. The findings show that size of municipality, age and education affect the intention to emigrate. It is found that the digital divide in terms of quality of ICT access has not, in many cases, been overcome, having an effect on citizen satisfaction. To guide public actions, we identify population profiles depending on both level of satisfaction with ICT development and preference towards specific ICT-related public policy measures intended to combat depopulation. We also find that most individuals continue to think that improving investment in ICT infrastructures should be a priority of public policy, compared to more advanced measures such as bolstering e-government.     

中国资本市场审计舞弊成本研究

近年来,国内外证券市场中出现的一系列会计丑闻,使注册会计师违规应承担的法律责任问题再次成为大家关注的话题,对此,许多学者进行了有益的探讨,但都仅仅限于相关法律法规对注册会计师法律责任如何规定上,对如何有效遏制注册会计师违规仍极少研究.笔者在本文中首先探讨了我国注册会计师违规需要承担的法律责任,及相关法律法规存在的问题;其次建立了注册会计师违规成本模型,从一个新的视角探讨了解决注册会计师违规的途径,提出只有提高违规成本,才能有效遏制注册会计师违规.     

面向管理的公共空间设计控制

城市公共空间因具有强烈的公共属性而具备了公共干预的法理基础,必须建立制度化的设计控制来保障公共利益不受损害.公共空间设计控制的制度化包括依据的制度化、内容的制度化和审查的制度化.     

创造符合寒地特征的城市公共空间以哈尔滨为例

文章从寒地的气候特征出发，分析了寒地城市在公共空间创造中应当注意的原则与方法，结合哈尔滨的城市空间创造实践，探讨如何创造符合寒地地域特征、体现城市历史文化内涵的城市公共空间。     

Effects of urbanization on Neotropical wasp and bee assemblages in a Brazilian metropolis

The rapid growth of cities in many parts of the world has stimulated an increasing number of ecological studies of urban environments. Here, 12 study sites in the city of Belo Horizonte (MG), southeastern Brazil, were compared to analyze the effects of habitat changes related to urbanization on the species richness and abundance of native wasps and bees. Two spatial scales were considered: large portions of the urban landscape (entire sites) and small areas within these sites (public squares). Overall, the abundance of advanced eusocial bees (i.e. stingless bees), which were the dominant species, was directly affected by the loss of vegetation cover and the increase of buildings associated with urbanization. The magnitude of this effect varied according to the nesting habits of each species. The loss of vegetation cover associated with urbanization also had a negative effect on the abundance and species richness of advanced eusocial wasps. Generalist species of bees and wasps, such as Trigona spinipes and Polybia occidentalis, were very abundant and not sensitive to the habitat changes related to urbanization. Advanced eusocial bees also responded to small-scale habitat changes (size and vegetation cover of public squares). No relation was found between the solitary and the primitive eusocial wasps and bees and the habitat changes considered here. Conservation strategies in urban environments need to consider different spatial scales in order to maintain or enhance the local diversity of wasps and bees.     

城市公共空间的特色塑造与规划引导

公共空间既是城市功能的主要组成部分,同时也是连接城市各功能区的重要纽带.对比欧洲城市在公共空间的历史文化氛围塑造、系统化建设、空间尺度及人性化设计等方面所进行的努力,我国城市应重点加强公共空间的系统化建设、公共空间历史文化氛围的传承与塑造、公共空间的合理尺度研究及人性化设计等方面的内容.     

由公共厕所的规划建设引发的思考

公共厕所在城市规划法规中占有重要地位。规划管理权必须高度集中。规划主管部门在城市发展中应为自己正确定位,树立良好的自身形象。     

谈信息设备招标技术文件的编制

介绍了国际机场航站楼公共广播和内部通讯系统的技术招标书的编写格式，及工程要求达到的技术性能指标。     

高雄捷運紅橘線交會大港埔圓形站體連續壁施工

高雄捷迎紅橘綜交會大港埔圓形站體為高雄捷迎路網通車之要徑工程。因此,為維持正常交通服務水準、有限工期、施工條件及安全等,連續壁施工選用水平多軸回轉式切削機以維持品質、控制挖掘精度及施工速度,另為避免造成連續壁之偏壓作用而損壞,站體之開挖順序安排亦為設计及施工人員重視之課題。