Bio-crude Turns Cheap Waste Into Valuable Fuel

Daily Science Journal (Feb. 5, 2008) — CSIRO and Monash University have developed a chemical process that turns green waste into a stable bio-crude oil. The bio-crude oil can be used to produce high value chemicals and biofuels, including both petrol and diesel replacement fuels.

Forest waste can be converted into bio-crude oil. (Credit: Image courtesy of CSIRO Australia)

“By making changes to the chemical process, we’ve been able to create a concentrated bio-crude which is much more stable than that achieved elsewhere in the world,” says Dr Steven Loffler of CSIRO Forest Biosciences.

“This makes it practical and economical to produce bio-crude in local areas for transport to a central refinery, overcoming the high costs and greenhouse gas emissions otherwise involved in transporting bulky green wastes over long distances.”

The process uses low value waste such as forest thinnings, crop residues, waste paper and garden waste, significant amounts of which are currently dumped in landfill or burned.

“By using waste, our Furafuel technology overcomes the food versus fuel debate which surrounds biofuels generated from grains, corn and sugar,” says Dr Loffler.

“The project forms part of CSIRO’s commitment to delivering cleaner energy and reducing greenhouse gas emissions by improving technologies for converting waste biomass to transport fuels.”

The plant wastes being targeted for conversion into biofuels contain chemicals known as lignocellulose, which is increasingly favoured around the world as a raw material for the next generation of bio-ethanol.

Lignocellulose is both renewable and potentially greenhouse gas neutral. It is predominantly found in trees and is made up of cellulose; lignin, a natural plastic; and hemicellulose.

CSIRO and Monash University will apply to patent the chemical processes underpinning the conversion of green wastes to bio-crude oil once final laboratory trials are completed.

The research to date is supported by funding from CSIRO’s Energy Transformed Flagship program, Monash University, Circa Group and Forest Wood Products Australia.

National Research Flagships CSIRO initiated the National Research Flagships to provide science-based solutions in response to Australia’s major research challenges and opportunities. The nine Flagships form multidisciplinary teams with industry and the research community to deliver impact and benefits for Australia.

Adapted from materials provided by CSIRO Australia.

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Malaria Vaccine Trials Begin Using 'Chimpanzee Virus'

Daily Science Journal (Feb. 1, 2008) — Trials are underway for a new vaccine to combat the most deadly form of malaria. For the first time ever, researchers will use a virus found in chimpanzees to boost the efficacy of the vaccine.

Malaria, caused by Plasmodium parasites, is one of the world's deadliest killers, killing over a million people each year, mainly women and young children in Africa and SE Asia. The most deadly species , P. falciparum, is responsible for 80% of malaria infections and 90% of deaths. As yet, there is no vaccine against malaria. This is because, for much of their life-cycle, the parasites responsible for infection live inside cells, where they cannot be reached by antibodies.

The trials will take place at the University of Oxford's Jenner Institute, led by its Director, Professor Adrian Hill.

"We urgently need a vaccine to help in the fight against this deadly killer," says Professor Hill, a Wellcome Trust* Principal Research Fellow. "Malaria parasites are able to outwit our immune system by hiding out in the body's cells, however. Finding a way to generate enough immune cells and antibodies to identify and destroy the parasites will be the key to preventing infection."

The vaccine being developed and trialled by Professor Hill's team in collaboration with Okairòs uses the company's genetically-modified chimpanzee adenovirus to produce the malaria antigen and to stimulate a response to the vaccine in the body. Adenoviruses appear to be particularly potent for increasing the immune response to the malaria vaccine. However, because human adenoviruses, which cause diseases including the common cold and gastroenteritis, are widespread, most people have developed some immunity towards them. Using a chimpanzee adenovirus ensures that a recipient is unlikely to have resistance to this component of the vaccine.

"Chimpanzees have their own set of adenoviruses which rarely infect humans, so we have not built up immunity to them," explains virologist Dr Sarah Gilbert at the Jenner Institute. "This is why we have chosen such a virus to form the backbone of the new vaccine."

Professor Hill's team is currently recruiting for more volunteers for the first trials, which are to assess the safety of the vaccine. Because the active component of the adenovirus is removed, however, there is no danger of transmission to the human of the original chimpanzee virus.

The trial will also be measuring the response of the immune system. The team hopes to generate a response from CD8+ T-cells (sometimes known as killer cells) that should kill the parasites when they enter the liver, where they multiply undetected. However, if the T-cells do not kill all of the parasites, any that escape from liver into the bloodstream will still be able to enter red blood cells and cause illness.

The group plans to test a second vaccine which would then target the parasites in the bloodstream and red blood cells.

"Our ultimate goal is a combination product which targets the parasite at both the liver stage and the blood stage," says Professor Hill. "Few people still think that you can get really strong protection from malaria based on a single component."

Over a dozen vaccines have now been made by scientists at the University of Oxford and taken into clinical trials, but this is the first vaccine to have also been manufactured within a UK university, according to Professor Hill.

*Funding was provided by the Wellcome Trust.

Adapted from materials provided by Wellcome Trust, via EurekAlert!, a service of AAAS.

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Tiny Avalanche Photodiode Detects Single UV Photons

Daily Science Journal (Feb. 1, 2008) — In a significant breakthrough, researchers at Northwestern University’s Center for Quantum Devices (CQD) have demonstrated visible-blind avalanche photodiodes (APDs) capable of detecting single photons in the ultraviolet region (360-200 nm).

Lower left, schematic diagram of a back illuminated single photon detector; Upper right, biasing circuit used to drive the single photon detector; Background, scanning electron micrograph of a processed array of single photon detectors. (Credit: Image courtesy of Northwestern University)

Previously, photomultiplier tubes (PMTs) were the only available technology in the short wavelength UV portion of the spectrum capable of single photon detection sensitivity. However, these fragile vacuum tube devices are expensive and bulky, hindering true systems miniaturization.

The Northwestern team, led by Manijeh Razeghi, Walter P. Murphy Professor of Electrical Engineering and Computer Science at Northwestern’s McCormick School of Engineering, became the world’s first to demonstrate back-illuminated single photon detection from a III-nitride photodetector. These back-illuminated devices, based on GaN compound semiconductors, benefit from the larger ionization coefficient for holes in this material. The back-illumination geometry will facilitate future integration of these devices with read-out circuitry to realize unique single-photon UV cameras. Towards that end, the team has already demonstrated excellent uniformity of the breakdown characteristics and gain across the wafer.

The devices are coupled with a quenching circuit and operated under large reverse bias, an arrangement termed in Geiger mode operation. The sensor system presents an effective photocurrent gain greater than 107, single photon detection efficiencies of 23 percent, dark count rates of less than 1 kHz, and no response to visible radiation.

Once optimized, discrete detectors could be combined with the ultraviolet LEDs already pioneered by the Center for Quantum Devices to create an inexpensive detection system capable of identifying the unique spectral fingerprints of a biological agent attack. They can also be paired with UV LEDs to create a new form of non-line of sight UV-communication, secure from remote eavesdropping.

These exciting new results were recently presented at the Defense Advanced Research Projects Agency (DARPA) during the Single Photon Detection Workshop hosted by Dr. Matthew Goodman, and held in Arlington, VA on Nov. 27, 2007 and at the SPIE Photonics West Conference held in San Jose, CA on Jan. 19-24, 2008. This work was also published in the July 23, 2007 issue of the journal Applied Physics Letters.

Adapted from materials provided by Northwestern University.

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Green Tea May Protect Bladder From Becoming Inflamed

Daily Science Journal (Jan 21, 2007) — Herbal agents could be used to treat inflammatory bladder diseases, according to a preliminary study that looked at the ability of green tea to protect bladder cells from inflammation. The University of Pittsburgh School of Medicine study, being presented at the annual meeting of the American Urological Association (AUA) in Anaheim, Calif., found that components of green tea protected bladder cells from damage in culture.

Green tea, reported to have many health benefits, is rich in powerful antioxidants that make it a possible remedy for many medical conditions. It is comprised of catechins -- plant metabolites that provide it with many anti-oxidative properties.

"We discovered that catechins found in green tea protected both normal and cancerous bladder cells from inflammation when we exposed the cells to hydrogen peroxide," said Michael B. Chancellor, M.D., professor of urology and gynecology at the University of Pittsburgh School of Medicine. "Although further studies are needed, these results indicate herbal supplements from green tea could be a treatment option for various bladder conditions that are caused by injury or inflammation."

In the study, normal and cancerous bladder cells were exposed to two major catechin components of green tea, epigallocatechin gallate (EGCG) and epicatechin gallate (ECG), for 23 hours. Both significantly protected cell lines from exposure to hydrogen peroxide, which damages or kills cells. The concentrations of EGCG and ECG used in the study were at levels that may be achieved through dietary intake.

Approximately ten million American adults have problems controlling their bladders. Bladder disease affects both men and women and can include incontinence or interstitial cystitis, a chronic inflammatory condition that causes frequent, urgent and painful urination and pelvic discomfort.

Co-investigators of the study include Shelby Morrisroe, M.D., Christian Coyle, Ph.D., Brian Phillips, Ph.D., William de Groat, Ph.D., and Naoki Yoshimura, M.D., Ph.D., all with the University of Pittsburgh School of Medicine. The study is Abstract 299 in the AUA proceedings.

The study is funded by the Fishbein Family CURE-IC Program.

Adapted from materials provided by University of Pittsburgh Schools of the Health Sciences, via EurekAlert!, a service of AAAS.

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