| Walter and Eliza Hall Institute of Medical Research |
An important mechanism controlling the
growth of rapidly-dividing cells has been revealed. This may lead to new
treatments for cancer and other diseases.
Image: Nataliya Hora/Shutterstock
The finding has revealed an important mechanism controlling the growth of rapidly-dividing cells that may ultimately lead to the development of new treatments for diseases including cancer. The discovery was made by Associate Professor Joan Heath, Dr Yeliz Boglev and colleagues at the Melbourne-Parkville Branch of the Ludwig Institute for Cancer Research. Dr Kate Hannan, Associate Professor Rick Pearson and Associate Professor Ross Hannon at the Peter MacCallum Cancer Centre, also contributed to the work, which was published in the journal PLOS Genetics. Associate Professor Heath, a Ludwig Institute Member who recently transferred her research group to the Walter and Eliza Hall Institute, said the discovery was made while studying zebrafish embryos that harbour genetic mutations which prevent rapid cell growth during organ development. “Zebrafish embryos provide us with a great laboratory model for these studies because they are transparent, an attribute that allows us to track the growth of rapidly developing organs in live animals under a simple microscope. Moreover, the genes controlling growth and proliferation of developing tissues are essentially identical in zebrafish and humans, and are known to be frequently commandeered by cancer cells.” “We discovered that a mutation in a relatively under-studied gene called pwp2h leads to the faulty assembly of ribosomes, the ‘protein factories’ of cells, and stops cells from dividing,” she said. “What was intriguing was that cells under stress from ribosome failure did not die. Instead, the cells switched on a survival mechanism called autophagy and began obtaining nutrients by digesting their own intracellular components.” Ribosomes are large molecular machines in cells that manufacture proteins, and are critical for cell growth and division. Currently, there is great interest in developing therapeutics to block ribosome production, as a strategy to prevent cancer cells from dividing. “Our research could have implications for this type of cancer treatment,” Associate Professor Heath said. “We showed that when ribosome assembly is disrupted, cells stop growing as desired, but to our surprise they enter a survival state. An anti-cancer treatment that inadvertently promotes the survival of cancer cells through autophagy is clearly not desirable. However, our findings in zebrafish show that if ribosome assembly is blocked and, at the same time, autophagy is inhibited, cells die rapidly. It is possible that a combination of inhibitors that block ribosome function and autophagy could provide an effective anti-cancer treatment,” she said. Associate Professor Heath’s group is continuing its research at the Walter and Eliza Hall Institute, examining other genetic mutations in zebrafish that disrupt cell growth and division. “We are keen to enhance our approach by applying existing research technologies at the institute,” she said. “We have identified a number of cellular processes that rapidly dividing cells – including cancer cells – depend on, and the next stage is to test whether they could provide new targets for anti-cancer therapy.” The research was supported by the National Health and Medical Research Council and the Victorian Government.
Editor's Note: Original news release can be found here.
|
A two-dimensional nano-material may be
converted to nano-transistors used in high-speed
electronics. The researchers say this may be the foundation of a new
electronics revolution.
Image: Image: Dr Daniel J White, Science FX
The material – made up of layers of crystal known as molybdenum oxides – has unique properties that encourage the free flow of electrons at ultra-high speeds. In a paper published in the January 2013 issue of Advanced Materials, the researchers explain how they adapted a revolutionary material known as graphene to create a new conductive nano-material. Graphene was created in 2004 by scientists in the UK and won its inventors a Nobel Prize in 2010. While graphene supports high-speed electrons, its physical properties prevent it from being used for high-speed electronics. The CSIRO's Dr Serge Zhuiykov said the new nano-material comprised layered sheets – similar to graphite layers that make up a pencil's core. "Within these layers, electrons can zip through at high speeds with minimal scattering," Dr Zhuiykov said. "The importance of our breakthrough is how quickly and fluently electrons – which conduct electricity – can flow through the new material." RMIT's Professor Kourosh Kalantar-Zadeh said the researchers were able to remove "roadblocks" that could obstruct the electrons, an essential step for developing high-speed electronics. "Instead of scattering when they hit roadblocks, as they would in conventional materials, they can simply pass through this new material and get through the structure faster," Professor Kalantar-Zadeh said. "Quite simply, if electrons can pass through a structure quicker, we can build smaller devices and transfer data at much higher speeds. "While more work needs to be done before we can develop actual gadgets using this new 2D nano-material, this breakthrough lays the foundation for a new electronics revolution, and we look forward to exploring its potential." In the paper titled 'Enhanced Charge Carrier Mobility in Two-Dimensional High Dielectric Molybdenum Oxide,' the researchers describe how they used a process known as "exfoliation" to create layers of the material ~11 nm thick. The material was manipulated to convert into a semiconductor, and nanoscale transistors were then created using molybdenum oxide. The result was electron mobility values of >1,100 cm2/Vs – exceeding the current industry standard for low dimensional silicon. The work, with RMIT doctoral researcher Sivacarendran Balendhran as the lead author, was supported by the CSIRO Sensors and Sensor Networks Transformational Capability Platform and the CSIRO Materials Science and Engineering Division. It was also a result of collaboration between researchers from Monash University, the University of California – Los Angeles (UCLA), CSIRO, Massachusetts Institute of Technology (MIT) and RMIT.
Editor's Note: Original news release can be found here.
|
| CSIRO |
The capture-and-release method is a major discovery as it helps capture CO2from power stations and releases it when exposed to sunlight.
Image: mikeledray/Shutterstock
The breakthrough presents a new way to recycle CO2 emissions using renewable energy. The 'sponge' which is made from a new smart material called a MOF (metal organic framework) adsorbs carbon dioxide, but when exposed to sunlight, instantaneously releases it. Known as dynamic photo-switching, this capture-and-release method is extremely energy efficient and only requires UV light to trigger the release of CO2 after it has been captured from the mixture of exhaust gases. Dr Matthew Hill, who was awarded a 2012 Eureka Prize for his MOF research and led the CSIRO group conducting this research, said: "The capture and release process can be compared to soaking up water with a sponge and then wringing it out. When UV light hits the material its structure bends and twists and stored gas is released." "This is an exciting development for carbon capture because concentrated solar energy can be used instead of further coal-based energy to drive the process," he added. The traditional process for carbon dioxide capture has been to use liquid absorbers such as amines to remove flue gases at a coal-fired power station before they are released into the atmosphere. They are then heated to release the CO2 which is then stored and can be re-used. This process can consume as a much as 30 per cent of a power plant's production capacity. MOFs absorb as much as a litre of nitrogen gas in just one gram of material. This is possible because MOFs have the surface area of a football field in just one gram, meaning that gases can be soaked up like a sponge to all of the internal surfaces within. In their paper titled "Dynamic Photo-Switching in Metal Organic Frameworks as a Route to Low Energy Carbon Dioxide Capture and Release" CSIRO researchers show that when exposed to concentrated UV light the MOF sponge instantaneously releases up to 64 per cent of absorbed CO2. Lead researcher and author of the paper, Richelle Lyndon, who is also a Monash University student, said: "The MOFs are impregnated with light-responsive azobenzene molecules which react to UV light and trigger the release of CO2. It is this reaction, and the material's ability to bend and flex, which makes the material we have created so unique."
Editor's Note: Original news release can be found here.
|
| The University of Western Australia |
|
For the first time researchers compared the effects of global warming in Arctic and Antarctic food chains.
Image: Image: Volodymyr Goinyk/Shutterstock
The research, co-authored by the Director of The University of Western Australia's Oceans Institute, Winthrop Professor Carlos Duarte, in conjunction with the Spanish National Research Council (CSIC), is based on the study of more than 700 species. The International Laboratory on Global Change (LINCGlobal) research analysed the feeding relationships among 145 Arctic and 586 Antarctic species. The results, published in the journal Marine Ecology Progress Series, show that global warming can affect the biodiversity of these ecosystems in different ways. The research found that the Arctic ecosystem, which has a higher proportion of predator species, is more susceptible to disturbances affecting species such as whales and polar bears higher up the food chain. According to the researchers, this phenomenon - called trophic cascade - represents a major threat to the ecosystem because disturbances among predator species are more likely to affect species at lower levels. The Antarctic food web, however, has a higher proportion of prey species and the effects of disturbances are most likely to affect species lower down the food chain. One example is evidence of a decrease of Antarctic krill caused by overfishing and climate change. "By applying complex network theory to understand the topology of polar food webs, we have found distinctive elements - which are also relative to non-polar food webs - that show polar food webs, particularly the Arctic one, are highly vulnerable to functional extinctions of key species, such as Antarctic krill in the Antarctic food web," Professor Duarte said. The study also shows that the Arctic food web has more omnivorous species than the Antarctic (80.71% vs. 41.13%). The loss of these species makes the Arctic more susceptible to invasion by other species. Arctic and Antarctic Poles are two of the regions where the effects of climate change are more intensely observed in the planet. While for the rest of the world an average increase in mean annual temperature of 0.5°C (32.9ºF) since 1950 has been recorded, for the Arctic and Antarctic Peninsula, an increase of about 1.5ºC (34.70°F) has been recorded.
Editor's Note: Original news release can be found here.
|
W : Well Graded
C : Clay binder
P : Poorly graded
M : Containing fine materials not covered in other groups.
