750 resultados para Surfaces (Technology)


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Phage display is an advanced technology that can be used to characterize the interactions of antibody with antigen at the molecular level. It provides valuable data when applied to the investigation of IgE interaction with allergens. The aim of this rostrum article is to provide an explanation of the potential of phage display for increasing the understanding of allergen- IgE interaction, the discovery of diagnostic reagents, and the development of novel therapeutics for the treatment of allergic disease. The significance of initial studies that have applied phage display technology in allergy research will be highlighted. Phage display has been used to clone human IgE to timothy grass pollen allergen Phl p 5, to characterize the epitopes for murine and human antibodies to a birch pollen allergen Bet v 1, and to elucidate the epitopes of a murine mAb to the house dust mite allergen Der p 1. The technology has identified peptides that functionally mimic sites of human IgE constant domains and that were used to raise antiserum for blocking binding of IgE to the FcεRI on basophils and subsequent release of histamine. Phage display has also been used to characterize novel peanut and fungal allergens. The method has been used to increase our understanding of the molecular basis of allergen-IgE interactions and to develop clinically relevant reagents with the pharmacologic potential to block the effector phase of allergic reactions. Many advances from these early studies are likely as phage display technology evolves and allergists gain expertise in its research applications.

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Designers have a social responsibility to deal with the needs, issues, and problems that their clients and communities are confronted with. Students of design require opportunities to reflect on their role as social facilitators to develop an attitude towards community engagement through different phases and aspects of their careers. However, current design courses are challenged by compressed timeframes and fragmented scenarios of different academic requirements that do not actively teach community engagement. This paper outlines a participatory and technological approach that was employed to address these issues within the teaching of Architecture and Urban Design at the Queensland University of Technology, Brisbane, Australia. A multi-phase community based research project with actual stakeholders was implemented over a two-year period. Approximately 150 students in the final year of the Bachelor of Design-Architecture; 10 students in the Master of Architecture and 15 students in the Master of Design-Urban Design have informed and influenced each others’ learning through the teaching and research nexus facilitated by this project. The technical approach was implemented in form of a bespoke digital platform that supported the display and discussion of digital media on a series of interactive touch walls. The platform allowed students to easily upload their final designs onto large interactive surfaces, where visitors could explore the media and provide comments. Through the use of this technical platform and the introduction of neogeography, students have been able to broaden their level of interaction and support their learning experience through external structured and unstructured feedback from the local community. Students have not only been exposed to community representatives, but they also have been working in parallel on a specific case study providing each other, across different years and courses, material for reflection and data to structure their design activities.

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Mobile devices are very popular among tertiary student populations. This study looks at student use of hand-held mobile devices within the context of a first year programming unit. This research sought for ways in which an educational app on these devices could be successfully integrated into such a class's learning.

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Purpose This paper aims to use the Model of Goal-Directed Behavior (MGB) to examine the factors affecting consumers’ continued use of emerging technology-based self-services (TBSSs) with credence qualities. Professional services, which traditionally require specialized knowledge and high levels of interpersonal interaction to produce owing to their credence qualities, are increasingly delivered via self-service technologies. Health services delivered via mobile devices, for example, facilitate self-care without direct involvement from health professionals. Design/methodology/approach A mental health service delivered via the Internet and mobile phone, myCompass, was selected as the research context. Twenty interviews were conducted with users of myCompass and the data were thematically analyzed. Findings The findings of the study showcase the unique determinants of consumers’ continued use of TBSSs with credence qualities relative to the more routine services which have been the focus of extant research. The findings further provide support for the utility of the MGB in explaining service continuance, although the importance of distinguishing between extrinsic and intrinsic motivational components of behavioral desire and capturing the impact of social influence beyond subjective norms is also highlighted. Originality/value This study contributes to recent research examining differences in consumer responses across TBSSs and behavioral loyalty to these services. It also provides empirical evidence for broadening and deepening the MGB within this behavioral domain.

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This action research study investigated face-to-face and wiki technology collaboration to enhance students' English writing skills in a second language (L2) class in Vietnam. The thesis is underpinned by socio-cultural theory and argues that collaborative learning using wikis led to an enhancement in L2 writing skills. The findings show that collaborating via wikis challenged traditional L2 writing pedagogy in the following ways: increased student autonomy; understanding formative feedback; and awareness of process writing, genre and audiences. This study contributes practical knowledge about affordances and constraints of collaborative writing using wikis in Vietnam and other countries where traditional pedagogies are prevalent.

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Through creative practice and written research, this thesis explores the peculiar qualities of surface materials, revealing a broader ethos of practice which I identify as care. I propose that care arises as a mode of being between artist and work, work and beholder, and between the parts of the work. The thesis situates the art practice within an ethical framework, premised on, but extending, Heidegger's ontological equation of care with being. The original contribution is in the claim that the particular qualities of worldly matter generate the terms for care as a particular mode of engagement that is reciprocal and intransitive.

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This paper presents a literature review and indicative findings that are part of ongoing research into aging and technology. The review finds that research on older technology users has contributed valuable information on the impact of age-related changes on technology use, as well as older adults’ acceptance and adoption of contemporary technologies. However, the majority of the research has been conducted from the perspective of age-related differences in use and performance, or it is medically-focused, examining the potential of technology to improve an individual’s quality of life (QoL), for example. Research on older people and technology does not adequately address the integration of technology into the everyday lives of older people. This paper identifies that there is substantial opportunity to examine older users’ everyday information and communication technology (ICT) use, and to inform technology design beyond measures of performance, usability and adoption.

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Advances in the field of Assisted Reproductive Technology (ART) have been revolutionary. This book focuses on the use of ARTs in the context of families who seek to conceive a matching sibling donor as a source of tissue to treat an existing sick child. Such children have been referred to as ‘saviour siblings’. Considering the legal and regulatory frameworks that impact on the accessibility of this technology in Australia and the UK, the work analyses the ethical and moral issues that arise from the use of the technology for this specific purpose. The author claims the only justification for limiting a family’s reproductive liberty in this context is where the exercise of reproductive decision-making results in harm to others. It is argued that the harm principle is the underlying feature of legislative action in Western democratic society, and as such, this principle provides the grounds upon which a strong and persuasive argument is made for a less-restrictive regulatory approach in the context of ‘saviour siblings’.

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New media technologies and the narrative turn in qualitative research has expanded the methods through which we gather data about and share findings of groups who have traditionally been written about by others rather than telling their own stories to reveal the complexities of their experiences. This chapter explores two projects that use storytelling and technology in an effort to change public perceptions about disadvantaged a community or cohort that have specific circumstances but are a result of policies beyond their control.

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Model systems are critical to our understanding of self-assembly processes. As such, we have studied the surface self-assembly of a small and simple molecule, indole-2-carboxylic acid (I2CA). We combine density functional theory gas-phase (DFT) calculations with scanning tunneling microscopy to reveal details of I2CA assembly in two different solvents at the solution/solid interface, and on Au(111) in ultrahigh vacuum (UHV). In UHV and at the trichlorobenzene/highly oriented pyrolytic graphite (HOPG) interface, I2CA forms epitaxial lamellar structures based on cyclic OH⋯O carboxylic dimers. The structure formed at the heptanoic acid/HOPG interface is different and can be interpreted in a model where heptanoic acid molecules co-adsorb on the substrate with the I2CA, forming a bicomponent commensurate unit cell. DFT calculations of dimer energetics elucidate the basic building blocks of these structures, whereas calculations of periodic two-dimensional assemblies reveal the epitaxial effects introduced by the different substrates.

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Studies of Bi heteroepitaxy on Si(001) have shown that lines grow to lengths of up to 500nm if the substrate is heated to above the Bi desorption temperature (500°C) during or after Bi deposition. Unlike many other nanoline systems, the lines formed by this nonequilibrium growth process have no detectable width dispersion. Although much attention has been given to the atomic geometery of the line, in this paper, we focus on how the lines can be used to create a majority 2×1 domain orientation. It is demonstrated that the Bi lines can be used to produce a single-domain orientation on Si(001) if the lines are grown on Si(001) surfaces with a regular distribution of single height steps. This is a compelling example of how a nanoscale motif can be used to modify mesoscopic surface structure on Si(001).

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The equilibrium geometry, electronic structure and energetic stability of Bi nanolines on clean and hydrogenated Si(001) surfaces have been examined by means of ab initio total energy calculations and scanning tunnelling microscopy. For the Bi nanolines on a clean Si surface the two most plausible structural models, the Miki or M model (Miki et al 1999 Phys. Rev. B 59 14868) and the Haiku or H model (Owen et al 2002 Phys. Rev. Lett. 88 226104), have been examined in detail. The results of the total energy calculations support the stability of the H model over the M model, in agreement with previous theoretical results. For Bi nanolines on the hydrogenated Si(001) surface, we find that an atomic configuration derived from the H model is also more stable than an atomic configuration derived from the M model. However, the energetically less stable (M) model exhibits better agreement with experimental measurements for equilibrium geometry. The electronic structures of the H and M models are very similar. Both models exhibit a semiconducting character, with the highest occupied Bi-derived bands lying at ~0.5 eV below the valence band maximum. Simulated and experimental STM images confirm that at a low negative bias the Bi lines exhibit an 'antiwire' property for both structural models.

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Experimental studies of Bi heteroepitaxy on Si(001) have recently uncovered a self-organised nanoline motif which has no detectable width dispersion. The Bi lines can be grown with an aspect ratio that is greater than 350 : 1. This paper describes a study of the nanoline geometry and electronic structure using a combination of scanning tunneling microscopy (STM) and ab initio theoretical methods. In particular, the effect that the lines have on Si(001) surface structure at large length scales, l > 100 nm, is studied. It has been found that Bi line growth on surfaces that have regularly spaced single height steps results in a 'preferred' domain orientation.

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Although a wide range of periodic surface nets can be grown on low index silicon surfaces, only a few of these have quasi-one dimensional symmetry. If high index silicon surfaces, such as (553) and (557), are used instead, the surface unit cell contains steps. It is possible to fabricate a number of quasi-one dimensional nanoline systems on the terraces and some of these have nested energy bands near the Fermi level. These nano-scale systems may support exotic many-electron states produced by enhanced electron correlations and a reduction in electron screening in one spatial dimension. In this paper, our groups' experimental and theoretical studies of nanolines phases, grown on both low index and vicinal silicon surfaces are reviewed. These studies give us insight into the electronic properties of artificial nanoline structures.

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We investigated the influence of different gas environments on the fabrication of surfaces, homogeneously covered with equally sized and spaced micro-structures. Two types of structures have been successfully micro-machined with a femtosecond laser on titanium surfaces in various atmospheres. The surface chemistry of samples machined in oxygen and helium shows TiO2, while machining in nitrogen leads to an additional share of TiN. The actual surface structure was found to vary significantly as a function of the gas environment. We found that the ablated particles and their surface triggered two consecutive events: The optical properties of the gas environment became non-isotropic which then led to the pulse intensity being redistributed throughout the cross section of the laser beam. Additionally, the effective intensity was further reduced for TiN surfaces due to TiN's high reflectivity. Thus, the settings for the applied raster-scanning machining method had to be adjusted for each gas environment to produce comparable structures. In contrast to previous studies, where only noble gases were found suitable to produce homogeneous patches, we obtained them in an oxygen environment.