In situ observation of structural changes in polycrystalline silver catalysts by environmental scanning electron microscopy

Morphology changes induced in polycrystalline silver catalysts as a result of heating in either oxygen, water or oxygen-methanol atmospheres have been investigated by environmental scanning electron microscopy (ESEM), FT-Raman spectroscopy and temperature programmed desorption (TPD). The silver catalyst of interest consisted of two distinct particle types, one of which contained a significant concentration of sub-surface hydroxy species (in addition to surface adsorbed atomic oxygen). Heating the sample to 663 K resulted in the production of 'pin-holes' in the silver structure as a consequence of near-surface explosions caused by sub-surface hydroxy recombination. Furthermore, 'pin-holes' were predominantly found in the vicinity of surface defects, such as platelets and edge structures. Reaction between methanol and oxygen also resulted in the formation of 'pin-holes' in the silver surface, which were inherently associated with the catalytic process. A reaction mechanism is suggested that involves the interaction of methanol with sub-surface oxygen species to form sub-surface hydroxy groups. The sub-surface hydroxy species subsequently erupt through the silver surface to again produce 'pin-holes'.

A combined environmental scanning electron microscopy and Raman microscopy study of methanol oxidation on silver(I) oxide

The techniques of environmental scanning electron microscopy (ESEM) and Raman microscopy have been used to respectively elucidate the morphological changes and nature of the adsorbed species on silver(I) oxide powder, during methanol oxidation conditions. Heating Ag2O in either water vapour or oxygen resulted firstly in the decomposition of silver(I) oxide to polycrystalline silver at 578 K followed by sintering of the particles at higher temperature. Raman spectroscopy revealed the presence of subsurface oxygen and hydroxyl species in addition to surface hydroxyl groups after interaction with water vapour. Similar species were identified following exposure to oxygen in an ambient atmosphere. This behaviour indicated that the polycrystalline silver formed from Ag2O decomposition was substantially more reactive than silver produced by electrochemical methods. The interaction of water at elevated temperatures subsequent to heating silver(I) oxide in oxygen resulted in a significantly enhanced concentration of subsurface hydroxyl species. The reaction of methanol with Ag2O at high temperatures was interesting in that an inhibition in silver grain growth was noted. Substantial structural modification of the silver(I) oxide material was induced by catalytic etching in a methanol/air mixture. In particular, "pin-hole" formation was observed to occur at temperatures in excess of 773 K, and it was also recorded that these "pin- holes" coalesced to form large-scale defects under typical industrial reaction conditions. Raman spectroscopy revealed that the working surface consisted mainly of subsurface oxygen and surface Ag=O species. The relative lack of sub-surface hydroxyl species suggested that it was the desorption of such moieties which was the cause of the "pin-hole" formation.

In situ imaging of catalytic etching on silver during methanol oxidation conditions by environmental scanning electron microscopy

Polycrystalline silver is used to catalytically oxidise methanol to formaldehyde. This paper reports the results of extensive investigations involving the use of environmental scanning electron microscopy (ESEM) to monitor structural changes in silver during simulated industrial reaction conditions. The interaction of oxygen, nitrogen, and water, either singly or in combination, with a silver catalyst at temperatures up to 973 K resulted in the appearance of a reconstructed silver surface. More spectacular was the effect an oxygen/methanol mixture had on the silver morphology. At a temperature of ca. 713 K pinholes were created in the vicinity of defects as a consequence of subsurface explosions. These holes gradually increased in size and large platelet features were created. Elevation of the catalyst temperature to 843 K facilitated the wholescale oxygen induced restructuring of the entire silver surface. Methanol reacted with subsurface oxygen to produce subsurface hydroxyl species which ultimately formed water in the subsurface layers of silver. The resultant hydrostatic pressure forced the silver surface to adopt a "hill and valley" conformation in order to minimise the surface free energy. Upon approaching typical industrial operating conditions widespread explosions occurred on the catalyst and it was also apparent that the silver surface was extremely mobile under the applied conditions. The interaction of methanol alone with silver resulted in the initial formation of pinholes primarily in the vicinity of defects, due to reaction with oxygen species incorporated in the catalyst during electrochemical synthesis. However, dramatic reduction in the hole concentration with time occurred as all the available oxygen became consumed. A remarkable correlation between formaldehyde production and hole concentration was found.

Reflection as a dialogic strategy for developing a professional identity

The benefits of reflective practice have been well established in the literature (Rogers, 2001), as have models to embed reflective thinking in higher education curriculum (Ryan and Ryan, 2012). Reflection is commonly envisaged as a textual practice, through which students ‘reflect in and on action’ (Schön 1983), and articulate their experiences, learning and outcomes in written portfolios, journals, or blogs. While such approaches to individual written reflection are undoubtedly beneficial for deepening insight and self-criticality, reflection can also provide other benefits when approached as a collaborative, oral activity. This poster presents a dialogic model of reflective practice that affords the opportunity for developing presentation skills, critique, community and professional identity formation. This dialogic approach to reflection is illustrated by a first year subject (‘KIB101 Visual Communication’ at QUT), in which students apply visual theory (presented in lectures) to communication and graphic design problems in the studio. In regular (fortnightly) presentations, they critically reflect upon their work in progress by aligning it with the concepts, design principles and professional language of the lectures. This iterative process facilitates responsive peer feedback, similarly couched in the formal terms of the discipline. This ‘mirrored reflection’ not only provides opportunities to incrementally improve, it also sets designs in a theoretical frame; provides the opportunity for comparative analysis (to see design principles applied by peers in different ways); to practice formal design language and presentation techniques of the discipline and; because peer critique is framed as an act of generosity; it affords the development of a supportive community of practice. In these ways, dialogic reflection helps students develop a professional voice and identity from first year. Evidence of impact is provided by quantitative and qualitative student feedback over several years, as well as institutional feedback and recognition.

No association between MTHFR A1298C and MTRR A66G polymorphisms, and MS in an Australian cohort

Multiple sclerosis (MS) is a complex neurological disease that affects the central nervous system (CNS) resulting in debilitating neuropathology. Pathogenesis is primarily defined by CNS inflammation and demyelination of nerve axons. Methionine synthase reductase (MTRR) is an enzyme that catalyzes the remethylation of homocysteine (Hcy) to methionine via cobalamin and folate dependant reactions. Cobalamin acts as an intermediate methyl carrier between methylenetetrahydrofolate reductase (MTHFR) and Hcy. MTRR plays a critical role in maintaining cobalamin in an active form and is consequently an important determinant of total plasma Hcy (pHcy) concentrations. Elevated intracellular pHcy levels have been suggested to play a role in CNS dysfunction, neurodegenerative, and cerebrovascular diseases. Our investigation entailed the genotyping of a cohort of 140 cases and matched controls for MTRR and MTHFR, by restriction length polymorphism (RFLP) techniques. Two polymorphisms: MTRR A66G and MTHFR A1298C were investigated in an Australian age and gender matched case-control study. No significant allelic frequency difference was observed between cases and controls at the α = 0.05 level (MTRR χ2 = 0.005, P = 0.95, MTHFR χ2 = 1.15, P = 0.28). Our preliminary findings suggest no association between the MTRR A66G and MTHFR A1298C polymorphisms and MS

Association of the NuMA region on chromosome 11q13 with breast cancer susceptibility

The development of breast cancer is a complex process that involves multiple genes at many stages, from initial cell cycle dysregulation to disease progression. To identify genetic variations that influence this process, we conducted a large-scale association study using a collection of German cases and controls and >25,000 SNPs located within 16,000 genes. One of the loci identified was located on chromosome 11q13 [odds ratio (OR)=1.85, P=0.017]. The initial association was subsequently tested in two independent breast cancer collections. In both sample sets, the frequency of the susceptibility allele was increased in the cases (OR=1.6, P=0.01). The susceptibility allele was also associated with an increase in cancer family history (P=0.1). Fine mapping showed that the region of association extends approximately 300 kb and spans several genes, including the gene encoding the nuclear mitotic apparatus protein (NuMA). A nonsynonymous SNP (A794G) in NuMA was identified that showed a stronger association with breast cancer risk than the initial marker SNP (OR=2.8, P=0.005 initial sample; OR=2.1, P=0.002 combined). NuMA is a cell cycle-related protein essential for normal mitosis that is degraded in early apoptosis. NuMA-retinoic acid receptor alpha fusion proteins have been described in acute promyelocytic leukemia. Although the potential functional relevance of the A794G variation requires further biological validation, we conclude that variations in the NuMA gene are likely responsible for the observed increased breast cancer risk.

Genetic polymorphisms in DPF3 associated with risk of breast cancer and lymph node metastases

Background Several studies have identified rare genetic variations responsible for many cases of familial breast cancer but their contribution to total breast cancer incidence is relatively small. More common genetic variations with low penetrance have been postulated to account for a higher proportion of the population risk of breast cancer. Methods and Results In an effort to identify genes that influence non-familial breast cancer risk, we tested over 25,000 single nucleotide polymorphisms (SNPs) located within approximately 14,000 genes in a large-scale case-control study in 254 German women with breast cancer and 268 age-matched women without malignant disease. We identified a marker on chromosome 14q24.3-q31.1 that was marginally associated with breast cancer status (OR = 1.5, P = 0.07). Genotypes for this SNP were also significantly associated with indicators of breast cancer severity, including presence of lymph node metastases ( P = 0.006) and earlier age of onset ( P = 0.01). The association with breast cancer status was replicated in two independent samples (OR = 1.35, P = 0.05). High-density association fine mapping showed that the association spanned about 80 kb of the zinc-finger gene DPF3 (also known as CERD4 ). One SNP in intron 1 was found to be more strongly associated with breast cancer status in all three sample collections (OR = 1.6, P = 0.003) as well as with increased lymph node metastases ( P = 0.01) and tumor size ( P = 0.01). Conclusion Polymorphisms in the 5' region of DPF3 were associated with increased risk of breast cancer development, lymph node metastases, age of onset, and tumor size in women of European ancestry. This large-scale association study suggests that genetic variation in DPF3 contributes to breast cancer susceptibility and severity.

Large-scale association study identifies ICAM gene region as breast and prostate cancer susceptibility locus

We conducted a large-scale association study to identify genes that influence nonfamilial breast cancer risk using a collection of German cases and matched controls and >25,000 single nucleotide polymorphisms located within 16,000 genes. One of the candidate loci identified was located on chromosome 19p13.2 [odds ratio (OR) = 1.5, P = 0.001]. The effect was substantially stronger in the subset of cases with reported family history of breast cancer (OR = 3.4, P = 0.001). The finding was subsequently replicated in two independent collections (combined OR = 1.4, P < 0.001) and was also associated with predisposition to prostate cancer in an independent sample set of prostate cancer cases and matched controls (OR = 1.4, P = 0.002). High-density single nucleotide polymorphism mapping showed that the extent of association spans 20 kb and includes the intercellular adhesion molecule genes ICAM1, ICAM4, and ICAM5. Although genetic variants in ICAM5 showed the strongest association with disease status, ICAM1 is expressed at highest levels in normal and tumor breast tissue. A variant in ICAM5 was also associated with disease progression and prognosis. Because ICAMs are suitable targets for antibodies and small molecules, these findings may not only provide diagnostic and prognostic markers but also new therapeutic opportunities in breast and prostate cancer.

Analysis of androgen and anti-androgen regulation of KLK-related peptidase 2, 3, and 4 alternative transcripts in prostate cancer

We assessed whether alternative transcripts (using KLK2, KLK3 and KLK4 as models) are differentially regulated by androgens and anti-androgens as an indicator of prostate cancers as they acquire treatment resistance. Using RNAseq of LNCaP cells treated with dihydrotestosterone, bicalutamide and enzalutamide, we show that the expression of variant KLK transcripts is markedly different to other variant transcripts at those loci. We also reveal that KLK variants are also over 2-fold more highly expressed in prostate cancers compared to their corresponding normal prostate. We propose that androgens and anti-androgens can activate specific variant transcripts of critical prostate cancer genes during treatment resistance

Understanding requirements of novel healthcare information systems for management of advanced prostate cancer

Effective management of chronic diseases is a global health priority. A healthcare information system offers opportunities to address challenges of chronic disease management. However, the requirements of health information systems are often not well understood. The accuracy of requirements has a direct impact on the successful design and implementation of a health information system. Our research describes methods used to understand the requirements of health information systems for advanced prostate cancer management. The research conducted a survey to identify heterogeneous sources of clinical records. Our research showed that the General Practitioner was the common source of patient's clinical records (41%) followed by the Urologist (14%) and other clinicians (14%). Our research describes a method to identify diverse data sources and proposes a novel patient journey browser prototype that integrates disparate data sources.

Using a Capability Maturity Model to build on the generational approach to student engagement practices

The generational approach to conceptualising first year student learning behaviour has made a useful contribution to understanding student engagement. It has an explicit focus on student behaviour and we suggest that a capability maturity model interpretation may provide a complementary extension of that understanding as it builds on the generational approach by allowing an assessment of institutional capability to initiate, plan, manage, evaluate and review institutional student engagement practices. The development of a Student Engagement, Success and Retention Maturity Model (SESR-MM) is discussed along with its application in an Australian higher education institution. In this case study, the model identified first, second and third generation approaches and in addition achieved a ‘complementary extension’ of the generational approach, building on it by identifying additional practices not normally considered within the generational concept and indicating the capability of the institution to provide and implement the practices.

Storytelling beyond the anthropocene : a quest through the crises of ecocide toward new ecological paradigms

This project is a passionate and sometimes enraged thrust toward a biodiverse future. Weaving stories with deep thinking beyond the limits of the anthropocene, I am trying to recall myself in a more-than-human world. Our planet is suffering human induced ecocide which is a global crisis threatening the existence of multiple life forms. The alchemical mix of storytelling and ecological thinking could be part remedy for humanity's adaptation: a transformational mix to re-pattern the crisis into an opportunity and shift anthropocentric structures toward networks of dynamic relationships. The purpose of this project is to explore this cultural remedy. This is a quest, a search for tools that can germinate the hypothesis: storytelling in relation to ecological thinking manifests human potential in a more-than-human world. The practice-led research is guided by the philosophy and practice of Mythology, Deep ecology and Transdisciplinarity. Further navigation is sourced from Systems Thinking, Indigenous Methodologies, Biomimicry, and Quantum Physics. The journey unfolds by reawakening the Artist's function as caretaker of Mythology and pattern inciter for the collective. The resounding discovery of this adventure is Quantum Narratives: a storytelling tool for today's world, a method to connect multiple ways of knowing and diverse languages with the purpose of engaging, relating and working with living knowledge. Quantum Narratives are used to test the field study research into the Future of Water in context of Coal Seam Gas Mining in the Murray-Darling Basin and to materialise the collaborative results as the Water Stories. This thesis is a Living Script, full of imagination and complexity. Within its folds are strategies for systemic change ready to be adapted by policy and planning brokers and those who hold power for widespread remedial action.

Exosomes in prostate cancer: Putting together the pieces of a puzzle

Exosomes have been shown to act as mediators for cell to cell communication and as a potential source of biomarkers for many diseases, including prostate cancer. Exosomes are nanosized vesicles secreted by cells and consist of proteins normally found in multivesicular bodies, RNA, DNA and lipids. As a potential source of biomarkers, exosomes have attracted considerable attention, as their protein content resembles that of their cells of origin, even though it is noted that the proteins, miRNAs and lipids found in the exosomes are not a reflective stoichiometric sampling of the contents from the parent cells. While the biogenesis of exosomes in dendritic cells and platelets has been extensively characterized, much less is known about the biogenesis of exosomes in cancer cells. An understanding of the processes involved in prostate cancer will help to further elucidate the role of exosomes and other extracellular vesicles in prostate cancer progression and metastasis. There are few methodologies available for general isolation of exosomes, however validation of those methodologies is necessary to study the role of exosomal-derived biomarkers in various diseases. In this review, we discuss “exosomes” as a member of the family of extracellular vesicles and their potential to provide candidate biomarkers for prostate cancer.

Galectin-1 : a link between tumor hypoxia and tumor immune privilege

Purpose: To identify a 15-KDa novel hypoxia-induced secreted protein in head and neck squamous cell carcinomas (HNSCC) and to determine its role in malignant progression. Methods: We used surface-enhanced laser desorption ionization time-of-flight mass spectrometry (SELDI-TOF-MS) and tandem MS to identify a novel hypoxia-induced secreted protein in FaDu cells. We used immunoblots, real-time polymerase chain reaction (PCR), and enzyme-linked immunoabsorbent assay to confirm the hypoxic induction of this secreted protein as galectin-1 in cell lines and xenografts. We stained tumor tissues from 101 HNSCC patients for galectin-1, CA IX (carbonic anhydrase IX, a hypoxia marker) and CDS (a T-cell marker). Expression of these markers was correlated to each other and to treatment outcomes. Results: SELDI-TOF studies yielded a hypoxia-induced peak at 15 kDa that proved to be galectin-1 by MS analysis. Immunoblots and PCR studies confirmed increased galectin-1 expression by hypoxia in several cancer cell lines. Plasma levels of galectin-1 were higher in tumor-bearing severe combined immunodeficiency (SCID) mice breathing 10% O 2 compared with mice breathing room air. In HNSCC patients, there was a significant correlation between galectin-1 and CA IX staining (P = .01) and a strong inverse correlation between galectin-1 and CDS staining (P = .01). Expression of galectin-1 and CDS were significant predictors for overall survival on multivariate analysis. Conclusion: Galectin-1 is a novel hypoxia-regulated protein and a prognostic marker in HNSCC. This study presents a new mechanism on how hypoxia can affect the malignant progression and therapeutic response of solid tumors by regulating the secretion of proteins that modulate immune privilege. © 2005 by American Society of Clinical Oncology.