Role Of Transition Metal Ions And Redox Activity In The Development Of Atherosclerotic Plaques
Funder
National Health and Medical Research Council
Funding Amount
$196,018.00
Summary
Metal ions such as iron and copper have been reproted to be present in the lesions present in diseased human arteries and it has been suggested that these metal ions contribute to the development of atherosclerosis (hardening of the arteries) via their ability to catalyse the formation of highly reactive molecualr fragments called free radicals. Though metal ions are known to catalyse such reactions in test-tube experiments, both the presence of metal ions in diseased arteries and their ability ....Metal ions such as iron and copper have been reproted to be present in the lesions present in diseased human arteries and it has been suggested that these metal ions contribute to the development of atherosclerosis (hardening of the arteries) via their ability to catalyse the formation of highly reactive molecualr fragments called free radicals. Though metal ions are known to catalyse such reactions in test-tube experiments, both the presence of metal ions in diseased arteries and their ability to generate free radicals is controversial. This study will employ a novel, minimally-invasive, technique to assess the nature and quantity of metal ions present in well-defined human and animal lesions at different stages of lesion development. The ability of these metal ions to catalyse free radical formation from components present in the artery wall will also be assessed. The release of these metal ions from the artery wall to added organic molecules will be assessed as this might minimise their potential to cause damage, and provide a possible therapeutic strategy. These studies will therefore provide valuable information as to the significance and role of reactive metal ions in the development of human artery disease and the possible prevention, or minimisation, of such processes.Read moreRead less
Multi-copper Oxidase Mediated Iron Uptake In Ps. Aeruginosa And Other Pathogenic Bacteria: Mechanism And Role In Disease
Funder
National Health and Medical Research Council
Funding Amount
$73,500.00
Summary
Iron is essential for the growth of bacteria. One of the mechanisms used by humans (and other animals) to defend against bacteria that cause disease is to trap iron by binding it to a set of iron binding proteins eg. transferrin. In this way there is no free iron in the system, so bacteria that survive in humans have had to evolve specific mechanisms to remove the iron form these host proteins. The mechanisms of iron uptake in pathogenic bacteria have been studied extensively, and the iron uptak ....Iron is essential for the growth of bacteria. One of the mechanisms used by humans (and other animals) to defend against bacteria that cause disease is to trap iron by binding it to a set of iron binding proteins eg. transferrin. In this way there is no free iron in the system, so bacteria that survive in humans have had to evolve specific mechanisms to remove the iron form these host proteins. The mechanisms of iron uptake in pathogenic bacteria have been studied extensively, and the iron uptake systems are considered to be important of virulence factors (bacterial factors essential for causing disease). Humans and other higher organisms like Yeast have an iron uptake system that uses multi copper oxidase proteins (MCOs). These proteins have a ferroxidase activity, which converts iron from a protein bound insoluable form Fe (III) to a soluble form Fe(II), allowing it to be released from iron binding proteins. We have searched the genomes of many bacteria for a similar system and have discovered that many bacteria have MCOs. We wanted to test the idea that the bacteria MCOs we have identified may be involved in iron uptkae. If so, it would represent a huge step forward in understanding this important process and could lead to products for prevention or better treatment of infectious disease. We chose the disease causing bacterium Pseudomonas aeruginosa for our study. We have shown that the MCO has ferroxidase activity (Fe(III)>Fe(II), we have made a mutation in the MCO gene had have shown that the bacterium lacking MCO will not grow under certain conditions. These conditions are consistent with a defect in iron uptake. We have identified but not characterised several other key compnents of this iron uptake system. In the proposed work we wish to investigate all of the components of this iron uptake system in this important pathogen, and to initiate studies in other bacteria pathogens.Read moreRead less
Modelling of particle-fluid reactive flows coupled with phase changes. This project aims to develop an integrated mathematical model for reliably describing multiphase reactive flow coupled with phase change. Particle-fluid reactive flows with phase changes are widely encountered in many energy-intensive industries, yet process design and optimization are hindered by the lack of understanding of complex phenomena governing particularly multiphase flow, phase change and their interactions. The m ....Modelling of particle-fluid reactive flows coupled with phase changes. This project aims to develop an integrated mathematical model for reliably describing multiphase reactive flow coupled with phase change. Particle-fluid reactive flows with phase changes are widely encountered in many energy-intensive industries, yet process design and optimization are hindered by the lack of understanding of complex phenomena governing particularly multiphase flow, phase change and their interactions. The model will be achieved by means of combining advanced particle-scale numerical techniques with pre-database-based thermodynamic model, supported by physical experiments. The outcomes will be applied across a range of industries of vital importance to Australian economic and technological future. It will help transform Australian pyrometallurgy and chemical industries, open new markets for a range of Australian minerals like low-grade coal and iron/copper ore, and ultimately enhance competitiveness of Australian economy.Read moreRead less
The early evolution of the Earth system from multiple sulfur isotope records of sediments and seafloor mineral systems. This project addresses the early evolution of the Earth system that is one of the most important questions in Earth Sciences. It will use Australia's unique rock record and analytical techniques developed in Australia in collaboration with leading international researchers. The National Research Priority area 'An environmentally sustainable Australia: developing deep Earth reso ....The early evolution of the Earth system from multiple sulfur isotope records of sediments and seafloor mineral systems. This project addresses the early evolution of the Earth system that is one of the most important questions in Earth Sciences. It will use Australia's unique rock record and analytical techniques developed in Australia in collaboration with leading international researchers. The National Research Priority area 'An environmentally sustainable Australia: developing deep Earth resources' will benefit through the development of better exploration models for Archaean submarine metal deposits. Students will obtain a high level understanding of the early Earth system, ore deposits, stable isotope and transition metal geochemistry, which are directly applicable in both pure and applied research and mineral exploration.Read moreRead less
Pyrite: a deep-time capsule of ocean chemistry and atmosphere oxidation. Surprisingly little is known about trace element trends in past oceans, even though these data are vital for interpreting the evolution of the Earth's atmosphere, evolutionary pathways of marine life and cycles of major mineral deposits. Using laser-based analysis of sedimentary pyrite in deep marine rocks, this project aims to produce, for the first time, temporal variation curves for 25 trace elements in seawater over the ....Pyrite: a deep-time capsule of ocean chemistry and atmosphere oxidation. Surprisingly little is known about trace element trends in past oceans, even though these data are vital for interpreting the evolution of the Earth's atmosphere, evolutionary pathways of marine life and cycles of major mineral deposits. Using laser-based analysis of sedimentary pyrite in deep marine rocks, this project aims to produce, for the first time, temporal variation curves for 25 trace elements in seawater over the last 3.5 billion years. Preliminary research has validated the technique and demonstrated major changes in certain trace elements over geologically short periods. Outcomes will assist the minerals industry in the discovery of new deposits of zinc, copper, gold and iron ore in Australia.Read moreRead less
Studies on metal dusting : reaction mechanisms and their control. Gases which are supersaturated with carbon can react at high temperatures with steels and nickel-base alloys to destroy them, producing a dust of carbon plus metal and/or metal carbides. The mechanism is not properly understood, and the rate of the process impossible to predict. This program will dissect the mechanism using kinetic studies and electron microscopy of precisely located parts of the reacting system. Ways of controll ....Studies on metal dusting : reaction mechanisms and their control. Gases which are supersaturated with carbon can react at high temperatures with steels and nickel-base alloys to destroy them, producing a dust of carbon plus metal and/or metal carbides. The mechanism is not properly understood, and the rate of the process impossible to predict. This program will dissect the mechanism using kinetic studies and electron microscopy of precisely located parts of the reacting system. Ways of controlling the process via alloy compositional changes will be explored.Read moreRead less
"Metal dusting" of austenitic alloys: mechanisms and interventions. "Metal dusting" is a catastrophic form of metal corrosion which we do not yet understand. It affects industries important to Australia: reforming of natural gas and (potentially) ceramic oxide fuel cells. This project aims to understand the process of austenitic alloy dusting, and thereby design materials to resist this form of attack. This will allow new natural gas processing industries in Australia to be internationally compe ...."Metal dusting" of austenitic alloys: mechanisms and interventions. "Metal dusting" is a catastrophic form of metal corrosion which we do not yet understand. It affects industries important to Australia: reforming of natural gas and (potentially) ceramic oxide fuel cells. This project aims to understand the process of austenitic alloy dusting, and thereby design materials to resist this form of attack. This will allow new natural gas processing industries in Australia to be internationally competitive.
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Controlling corrosion of steel by carbon dioxide-rich gases at high temperatures. A growing difficulty for Australia is the need to reduce carbon dioxide (CO2) emissions whilst maintaining the economic advantages of coal fired power stations. Technologies for capturing CO2 from these stations are being developed, but inevitably involve the need to handle hot CO2-rich gases. These are surprisingly corrosive to the materials of which power stations are constructed, in a way which is not fully unde ....Controlling corrosion of steel by carbon dioxide-rich gases at high temperatures. A growing difficulty for Australia is the need to reduce carbon dioxide (CO2) emissions whilst maintaining the economic advantages of coal fired power stations. Technologies for capturing CO2 from these stations are being developed, but inevitably involve the need to handle hot CO2-rich gases. These are surprisingly corrosive to the materials of which power stations are constructed, in a way which is not fully understood. This project aims to achieve this understanding, and to provide the basis for future alloy design.Read moreRead less
Multi-scale modelling of particle breakage in grinding process. The minerals industry is the largest exporter in Australia, contributing approximately 40% of Australia's total exports. Grinding is one of basic operations in mineral processing to liberate valuables from the host rock. Grinding process, however, has very low efficiency and may account for 50% of the direct operating cost of a mineral processing plant. This project is to develop a novel, multi-scale model to investigate grinding at ....Multi-scale modelling of particle breakage in grinding process. The minerals industry is the largest exporter in Australia, contributing approximately 40% of Australia's total exports. Grinding is one of basic operations in mineral processing to liberate valuables from the host rock. Grinding process, however, has very low efficiency and may account for 50% of the direct operating cost of a mineral processing plant. This project is to develop a novel, multi-scale model to investigate grinding at both process and individual particle levels and to provide a more accurate prediction of grinding performance. This will result in improved control and design of grinding process with reduced energy consumption and mineral waste, which will be of immense economic and environmental benefit to Australia.Read moreRead less
Modeling fluid flow and mineralisation at crustal interfaces. Several types of mineral resources, including some uranium, iron, and base metal ore deposits, may be created by fluid flow through and around interfaces in the Earth's crust. By understanding how, where and why such deposits form, we will assist exploration for future resources of these metals. Insights will also be gained into petroleum resource generation and extraction, the distribution of seismicity and volcanoes in time and spac ....Modeling fluid flow and mineralisation at crustal interfaces. Several types of mineral resources, including some uranium, iron, and base metal ore deposits, may be created by fluid flow through and around interfaces in the Earth's crust. By understanding how, where and why such deposits form, we will assist exploration for future resources of these metals. Insights will also be gained into petroleum resource generation and extraction, the distribution of seismicity and volcanoes in time and space, the problems of underground nuclear waste disposal and sequestration of CO2, and the potential for geothermal energy, with benefits in resource identification and/or hazard assessment in these areas.Read moreRead less