998 resultados para Lectins -- chemistry -- immunology


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pH-detachable poly(styrene) brushes formed on indium−tin oxide (ITO) glass substrates using metal complex chemistry and reversible addition−fragmentation chain transfer (RAFT) polymerization was described. These pH-detachable polymeric brushes were generated using both “graft-from” and “graft-to” methodologies. The methodologies involved either the surface self-assembly of catechol-functional RAFT agents (graft-from) or catechol-terminal polymer chains (graft-to) onto the ITO substrate via titanium−diol coordination. The stepwise functionalization of the ITO glass surfaces was characterized successfully using X-ray photoelectron spectroscopy (XPS) and contact angle measurement. Poly(styrene) brushes generated using the “graft-from” method were denser than those generated using the “graft-to” method, as exemplified by atom force microscopy (AFM) and quantified using cyclic voltammetry. Poly(styrene) brushes assembled using both methods could be detached easily by manipulating the pH of the brush environment. Cyclic voltammetry was utilized to calculate precisely the surface coverage of the RAFT functionality and polymeric brush density.

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This Account covers research dating from the early 1960s in the field of low-melting molten salts and hydrates,which has recently become popular under the rubric of “ionic liquids”. It covers understanding gained in the principal author’s laboratories (initially in Australia, but mostly in the U.S.A.) from spectroscopic, dynamic, and thermodynamic studies and includes recent applications of this understanding in the fields of energy conversion and biopreservation. Both protic and aprotic varieties of ionic liquids are included, but recent studies have focused on the protic class because of the special applications made possible by the highly variable proton activities available in these liquids.

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Interfacial chemistry and adhesion between titanium dioxide (TiO2) nanotube layers and titanium (Ti) substrates were studied in this Article. TiO2 nanotube layers were produced on pure Ti by anodization and annealed in air for different time durations. The adhesion of the TiO2 nanotube layers was then investigated by Rockwell C indentation test. Results show that adhesion of TiO2 nanotube layers improved with the extension of annealing time. This improvement in adhesion of TiO2 nanotube layers was analyzed from the viewpoint of interfacial chemistry using energy dispersive X-ray spectrometry (EDS) and X-ray photoelectron spectroscopy (XPS). It suggests that more Ti-O bonds formed in the interface after annealing, and this led to the improved adhesion of the TiO2 nanoube layers.

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In this paper measurements of the forces acting between two solid surfaces separated by a thin liquid film are discussed. By investigating these forces in a range of different liquids and solutions, it is possible to acquire an understanding of the surface properties of the solid material. The surface of mica has been studied extensively in this way, and the results obtained are reviewed to illustrate how the surface force measurements can give surface chemical information. Recent measurements on two other materials, sapphire and silica, which are of greater practical interest are also discussed.

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The underlying assumption in chemistry education is that chemistry is real, distinct discipline, clearly differentiable from other sciences. Chemistry is the study of matter and its interactions with other matter and with energy, but the aspects which distinguish chemistry are: macroscopic observations and descriptions of properties and change; understanding in terms of atoms and molecules; abstract representations to describe and communicate chemical concepts; and occupational health and safety. These aspects are not unique to chemistry, but their combination make chemistry unique. Over the last three years, there have been major reviews of school science education through the formulation of the Australian National Curriculum and of undergraduate education through the Learning and Teaching Academic Standards Project. In both cases, individual RACI members and chemistry professionals, including school teachers, and RACI working party and workshop, have articulated the unique nature of chemistry and the need for chemistry education as a separate subject.

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Enrolments in Australian Year 11 and year 12 chemistry are declining. In 1992, 23% of Australian year 12 students studied chemistry, decreasing to 18% in 2010. For science as a whole, the decrease is even more dramatic, from 94% to 51%. The decrease is slowing, but is continuing.
How should we respond to the report? Firstly, we should realise that it is not all gloom and doom. Secondly, education is not solely the responsibility of curriculum authorities and teachers. Each RACI member can communicate, inform and generally educate the wider community about the excitement and value of chemical science. Just a couple of hours of your time is not a panacea, but it can still make long-lasting impacts and affect career choices: even the largest beach consists of tiny individual grains of sand.

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Final report of the the Active Learning in University Science (ALIUS) project.

This project aims to establish a new direction in first year chemistry teaching – away from didactic teaching methods in large lecture style teaching to more active, student centred learning experiences. Initially six universities have been involved in practice-based innovation: Charles Sturt University (NSW), The University of Sydney (NSW), Curtin University of Technology (WA), The University of Adelaide (SA), Deakin University (Vic), University of Tasmania (Tas).

Three domains have been identified as the architecture upon which sustainable L&T innovation will be built. These domains include Learning and Teaching innovation in project leaders’ and colleagues’ classrooms, development of project leaders as Science Learning Leaders, and creation of a Science Learning Hub to serve as a locus and catalyst for the development of a science teaching community of practice.

Progress against specified outcomes and deliverables

Learning and Teaching Innovation

The purpose of this domain is to improve student learning, engagement, retention and performance in large chemistry classes through increased use of student-centred teaching practice.
• The Project is named: ALIUS (Active Learning in University Science) - Leading Change in Australian Science Teaching
• All six ALIUS universities have now implemented Teaching Innovation into ALIUS team member classrooms
Chemistry colleagues at three ALIUS universities have now implemented Teaching Innovation into their classrooms
• The ALIUS member in physics has implemented Teaching Innovations into his classrooms
Chemistry colleagues at three ALIUS institutions have tried some Teaching Innovations in their classrooms
• Non-chemistry colleagues at four ALIUS institutions have tried, or expressed an interest in trying, Teaching Innovations in their classrooms
• The POGIL method has proved to be a useful model for Teaching Innovation in the classroom
• Many classroom resources have been developed and used at several ALIUS institutions; some of these have been submitted to the ALIUS database for public access. The remainder will continue to submitted
• Two seminars about Teaching Innovation have been developed, critiqued, revised, and presented at five ALIUS universities and three non-ALIUS universities
• Particular issues associated with implementing Teaching Innovations in Australian classrooms have been identified and possible solutions developed
• ALIUS members have worked with Learning and Teaching Centres at their universities to share methods.

Developing Science Learning Leaders

The purpose of this domain is to develop leadership capacity in the project leaders to equip them with skills to lead change first at their institutions, followed by developing leaders and leading change at other local institutions
• ALIUS members participated in Leadership Professional Development sessions with Craig McInnis and Colin Mason; both these sessions were found to be valuable and provide context and direction for the members and the ALIUS team
• The passion of an ‘early adopter’ was found to be a significant element in each node of the distributed framework
• Members developed an awareness of the necessity to build both the ‘sense of urgency’ and the ‘guiding coalition’ at each node
• ALIUS found the success of the distributed framework is strongly influenced by the relational aspects of the team.

Create a Science Learning Hub

The online Hub serves as a local and national clearinghouse for development of institutional Learning Leaders and dissemination of L&T innovation.
• The ALIUS website is now active and being populated with resources
• The sharing resource database structure is finalised and being populated with contributed materials.

Lessons Learnt

In order to bring about change in teaching practice it is necessary to:
• demonstrate a convincing benefit to student learning
• show that beyond an initial input of effort classroom innovations will not take more time than what is now done
• maintain a prominent exposure among colleagues - repeatedly give seminars, workshops, and everyday conversations; talk about teaching innovation; talk about easy tools to use; invite people to your classroom; engage colleagues in regular peer review of classroom practice
• have support from people already present in leadership roles to lead change in teaching practice
• have a project leader, someone for whom the project is paramount and will push it forward
• find a project manager, even with money budgeted
• meet face-to-face.

Dissemination
• Seminars presented 19 times including over 400 individuals and more than 24 Australian universities
• Workshops presented 25 times, over 80 participants at 11 Australian and two New Zealand Universities
• Two articles published in Chemistry in Australia, the Australian Chemistry Industry Journal of the Royal Australian Chemical Institute
• One refereed paper published in the Journal of Learning Design.

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This study examined the properties of 1 wt.% vinylene carbonate, vinyl ethylene carbonate, and diphenyloctyl phosphate additive electrolytes as a promising way of beneficially improving the surface and cell resistance of Li-ion batteries. The additive electrolytes were dominant both in surface formation and internal resistance. In particular, electrochemical impedance spectroscopy, Fourier transform infrared spectroscopy and scanning electron microscopy confirmed that diphenyloctyl phosphate is an excellent additive to the electrolyte in the Li-ion batteries due to the improved co-intercalation of the solvent molecules.

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 In the Australian National Curriculum, the science understanding of overarching ideas of matter and energy covers science topics in the conceptual area of chemistry, such as the properties, forms and uses of different materials, the states of matter (solid, liquid and gas), and energy, such as forces, movement and electricity. This chapter focusses on explaining the abstract science ideas related to matter and energy through the use of appropriate vocabulary, examining ways of organising knowledge and linking scientific models and theories to observations and experiences. The particle model of matter is used to explain common observations, demonstrating the value of scientific inquiry and the role of models and representations in scientific thinking. A directed inquiry teaching approach in which there is a focus on the use of representations is recommended for these abstract topics. Representations are a vital component of communicating the abstract ideas of matter and energy. The use of the pedagogical approach in which students construct and evaluate representations of scientific ideas is used in the negotiation and development of their understandings.