626 research outputs found

    Synthesis of Fluorescent Molecules and their Applications as Viscosity Sensors, Metal Ion Indicators, and Near-Infrared Probes

    Get PDF
    The primary focus of this dissertation is the development of novel fluorescent near-infrared molecules for various applications. In Chapter 1, a compound dU-BZ synthesized via Sonogashira coupling reaction methodology is described. A deoxyuridine building block was introduced to enhance hydrophilic properties and reduce toxicity, while an alkynylated benzothiazolium dye was incorporated for near-IR emission and reduce photodamage and phototoxicity that is characteristic of common fluorphores that are excited by UV or visible light. A 30-fold enhancement of fluorescence intensity of dU-BZ was achieved in a viscous environment. Values of fluorescence quantum yields in 99% glycerol/1% methanol (v/v) of varying temperature from 293 K to 343 K, together with fluorescence quantum yields, radiative and nonradiative rate constants and fluorescence lifetimes in glycerol/methanol solutions of varying viscosities from 4.8 to 950 cP were determined. It was found that both fluorescence quantum yields and fluorescence lifetimes increased with increasing viscosity, which is consistent with results predicted by theory. This suggests that the newly designed compound dU-BZ is capable of functioning as a probe of local microviscosity, and was later confirmed by in vitro bioimaging experiments. In Chapter 2, a new BAPTA (O,O*-bis(2-aminophenyl)ethyleneglycol-N,N,N*,N*-tetra acetic acid) and BODIPY (4,4-difluoro-4-bora-3a,4a-diaza-s-indacene)-based calcium indicator, BAPBO-3, is reported. A new synthetic route was employed to simplify both synthesis and purification, which tend to be low yielding and cumbersome for BAPTA derivatives. Upon excitation, a 1.5-fold increase in fluorescence intensity in buffer containing 39 ?? Ca2+ and a 3-fold increase in fluorescence intensity in buffer containing 1 M Ca2+ was observed; modest but promising fluorescence turn-on enhancements. In Chapter 3, a newly-designed unsymmetrical squaraine dye, SQ3, was synthesized. A one-pot synthesis was employed resulting in a 10% yield, a result that is generally quite favorable for the creation of unsymmetrical squaraines Photophysical and photochemical characterization was conducted in various solvents, and a 678 nm absorption maximum and a 692 nm emission maximum were recorded in DMSO solution with a fluorescence quantum yield of 0.32. In vitro cell studies demonstrated that SQ3 can be used as a near-IR probe for bioimaging

    Identifying appropriate materials for English language learners

    Get PDF
    For ESL teachers, one of most important jobs is to choose appropriate materials for their students. However, some teachers may not know how to identify appropriate materials. Lexical coverage can provide some indication of the appropriacy of materials. Lexical coverage refers to the percentage of known words in a text. A context with low lexical coverage may not be appropriate for learning because students may not understand it. Nation (2006) stated that knowing 98% of words in a text may be ideal for adequate comprehension and therefore the material that teachers choose for students should include 98% of known words. Teachers can use the Vocabulary Level Test (Webb, Sasao, & Ballance, 2017) to determine the amount of words that students have mastered and analyze materials using a lexical profiler. A lexical profiler is a tool that can help teachers to identify the frequency of each word in text. It is easy to use and reveals the proportion of words in each word frequency level. Based on students’ vocabulary level and the results of a vocabulary profiler, teachers can determine whether their materials are likely to be understood by students. This talk will explain how to use each of these tools and show how they can be used to find appropriate materials for students

    The way of chinese medical reform : new trends in the era of the “internet+” and big data

    Get PDF
    Mestrado em Desenvolvimento e Cooperação InternacionalA China é um país com uma população imensa, com recursos médicos insuficientes e distribuição desigual. Portanto, existem muitos problemas no serviço de saúde. Devido ao desenvolvimento atrasado do sistema médico, a qualidade dos recursos médicos é baixa, o custo é alto e a eficiência dos serviços médicos é baixa. Um dos principais fatores explicativos dessa situação é a falta de apoio do governo e seguro médico imperfeito. Para resolver esse problema, o governo começou a reformar o sistema de segurança médica. Desde a reforma do seguro médico de 1988, após várias mudanças, o sistema de seguro médico da China amadureceu gradualmente. A tese descreve brevemente a estrutura básica, o conteúdo e o caminho da mudança nos cuidados de saúde. E as deficiências do atual sistema de seguro médico. A análise introduz o papel da "Internet+" e da "big data" na reforma do sistema de seguro médico e avalia as potencialidades da sua introdução e operacionalização para a gestão e governança do sistema de saúde.China is a population republic country has insufficient medical resources and uneven distribution. Therefore, there are many medical problems. Due to the backward development of the medical system, the quality of medical resources is poor, the efficiency of medical services is low, and the cost is high, which brings many difficulties for the Chinese people to seek medical treatment. However, one of the main factors of these problems is the lack of government support and imperfect medical insurance. To solve this problem, the government began to reform the medical security system. Since the 1988 medical insurance reform, after several changes, China's medical insurance system has gradually matured. The thesis will briefly describe the basic framework, content and path of change in health care. And the shortcomings of the current medical insurance system. According to the characteristics of the times, talk about the impact of "Internet +" and "Big Data" on the current Chinese industry, including people's lives. Therefore, the analysis introduces the positive role of big data Internet for the reform of medical insurance system, and provides convenience for the management and governance of medical insurance system. Analyze whether "Internet +" and "Big Data" can lead to new trends in the reform of the health care system.info:eu-repo/semantics/publishedVersio

    A Mini review of Node Centrality Metrics in Biological Networks

    Get PDF

    The Impact and Evolution of Individual’s Learning: An Empirical Study in Open Innovation Community

    Get PDF
    Learning is critical for individuals to increase their performance. However, this benefit of learning is not always realized. Previous studies have distinguished different classifications of learning approaches and reached inconsistent results. Therefore, this study further refines the classification of learning approaches in an open innovation community and explore the individual’s learning curve from a dynamic perspective. Specifically, we focus on whether and under what conditions learning can increase individual’s performance, and how individual\u27s learning curve changes over the tenure. To examine our hypotheses, we collect a dataset includes 48,820 game mods developed by 6,141 creators spanning 7-years from an open game innovation community. The results not only show the significant curve relationship between the four learning approaches and performance, but also demonstrate individual’s learning curve evolves over the tenure. This paper provides valuable suggestions and implications for individuals to choose appropriate learning approaches and obtain better performance under different tenures

    Organisational Commitment in UK Organisations: Do Cultural Backgrounds and Brexit Matter?

    Get PDF
    The research investigates whether cultural backgrounds and Brexit are determinants of organisational commitment in United Kingdom as the UK is a country with a multicultural working environment. Power distance, individualism/collectivism, work-life balance and language have all been tested in the research as cultural variables to examine participants’ difference on cultural background and whether there are differences on their organisational commitment level within the UK companies. The relationship between Brexit and organisational commitment have also all been tested in the research by analysing how EU employees value Brexit in regard to working in the UK and whether EU employees have different levels of organisational commitment. The topic is related to the current working environment in the UK as the cultural background of UK employees are more diverse than before. The topic is also relevant in UK’s current situation in the Europe as leaving the EU is an imperative and countless new problems are expected to arise including the issue of whether to continue working in the UK or not. The aim of this study is to help UK organisations to find solutions of increasing employees’ organisational commitment and to provide advice on how to manage EU employees during the post Brexit time

    Research on Multiple Complex Data Processing Methods Based on OpenStack Cloud Platform

    Full text link
    OpenStack is an open source cloud computing management platform project that supports almost all types of cloud environment. It can achieve data processing services among the interactive information storages, and it can also be stored in the virtual machine of cloud computing platform in various services. When performing complex data combination processing, each service cooperates with other services according to the interaction information, and finally completes the processing of complex data
    corecore