Features

Technology using catalysts which make hydrogen from formic acid could eventually replace lithium batteries and power a host of mobile devices.

Edman Tsang of Oxford University’s Department of Chemistry and colleagues are developing new catalysts which can produce hydrogen at room temperature without the need for solvents or additives.

Their initial results, reported in a recent paper in Nature Nanotechnology, are promising and suggest that a hydrogen fuel cell in your pocket might not be that far away.

The new approach involves placing a single atomic layer of palladium atoms onto silver nanoparticles. ‘The structural and electronic effects from the underlying silver greatly enhance the catalytic properties of palladium, giving impressive activity for the conversion of formic acid to hydrogen and carbon dioxide at room temperature,’ Edman told us.

He explains that the storage and handling of organic liquids, such as formic acid, is much easier and safer than storing hydrogen. The catalysts would enable the production of hydrogen from liquid fuel stored in a disposable or recycled cartridge, creating miniature fuel cells to power everything from mobile phones to laptops.

Another advantage of the new technology is that the gas stream generated from the reaction is mainly composed of hydrogen and carbon dioxide but virtually free from catalyst-poisoning carbon monoxide; removing the need for clean-up processes and extending the life of the fuel cells.

The chemists have worked closely with George Smith, Paul Bagot and co-workers at Oxford University’s Department of Materials to characterise the catalysts using atom probe tomography. The underlying technology is the subject of a recent Isis Innovation patent application.

‘There are lots of hurdles before you can get a real device, but we are looking at the possibility of using this new technology to replace lithium battery technology with an alternative which has a longer lifespan and has less impact on the environment,’ explains Edman.

Professor Edman Tsang is based at Oxford University’s Department of Chemistry.

Forensic science, fossil dating and volcanic eruptions were among the topics investigated by more than 400 secondary school students at this year’s Oxford University Science Roadshow.

Students also created their own solar cells, calculated the power the cells were generating and proposed research projects that could develop their potential.

The youngsters, aged from 11 to 18 and from six Oxfordshire schools, also had the chance to study particle physics and hear how it may be used to help treat cancer. They also learnt about and the links between geology and climate.

Roadshow organiser Dr Zareen Ahmed-Stewart, of Oxford’s Mathematical, Physical and Life Sciences Division, said: 'We are taking science, new equipment and ideas into schools and providing students with hands on experience. They’re always amazed at how science can be applied to everyday life.'

‘We’ve had lots of positive feedback from schools particularly those that find it difficult to come to Oxford. Many teachers are keen for us to run similar initiatives outside of the Roadshow.'

The event ran from 14-18 March and is staged annually during National Science & Engineering Week to give students an insight into science research at the university and broaden their interest in science.

This year’s Roadshow started at Matthew Arnold School where, guided by a technician and the Department of Materials' Schools Liaison Officer, Jayne Shaw, pupils constructed their own dye sensitised solar cells.

They compared the efficiency of different dyes and assessed how solar cell research may be developed. Their work was linked to ongoing research into photovoltaics at Oxford and elsewhere. This solar cells workshop was a development from a workshop earlier in the year which was supported by the National HE STEM Programme.

Jayne said: ‘I had a great morning and was made to feel very welcome at the school. The children were an enthusiastic and bright group. Several said how much they enjoyed the work with one saying “It was fabulous!”’

At the Oxford Academy and Burford School, students worked with Sarah Lloyd, Education Officer at the Oxford University Museum of Natural History,  to date the remains of fossils. They were shown how some fossils provide better evidence than others and the large amount of evidence needed to confirm initial findings about the age of fossils.

Sarah said: ‘The students enjoyed the practical element of the work and were surprised by the diversity of fossils they managed to isolate. Their teacher described the workshop as “totally captivating.”'

The Roadshow explored the world of chemistry at Cheney School where youngsters worked with undergraduates and graduates from the University’s Department of Chemistry.

They played forensic scientists in a game of Cluedo, analysing samples found at a crime scene to solve the mystery. Later, they created their own chemical rainbows by working out how to stack organic and inorganic solvents in order of their density.

Cheney students were also joined by experts from the Department of Earth Sciences who showed them a collection of rocks from different geological ages. The rocks revealed how the UK’s climate has changed and how the changes are related to the movement of the world’s tectonic plates.

‘One thing that particularly engaged many students was the moment when they realised that rather than being a boring homogenous grey lump the piece of rock in front of them was actually packed full of the fossilised remains of pre-historic creatures and told the story of an ancient tropical sea in the UK,’ said David Ferguson of the Department of Earth Sciences.

Students at Fitzharrys School in Abingdon got up close and personal with the exciting world of particle and accelerator physics. They learnt how particle accelerators can do everything from recreating conditions just after the Big Bang to finding new ways to treat cancer, as well as finding out how to drive the world's biggest machine - the Large Hadron Collider in Switzerland.

At Banbury School, Professor David Pyle from the Department of Earth Sciences explained how volcanoes form, and how they erupt as part of the cycle of tectonic movement, which in turn is driven by heat deep in the earth.

Professor Pyle said: 'My morning at Banbury School was lively not least because they have such a vibrant science area. I talked about the latest on the earthquake and tsunami in Japan and spent time with Year 12 chemists chatting about careers in science. The students listened well and fired several questions at me. It was definitely time well spent.'

An Oxford University scientist has taken our understanding of the origin of life a step further.

Professor Don Fraser from the Department of Earth Sciences has carried out neutron scattering experiments to try to find out more about the role of geochemistry in determining the origin of our amino acids – key building blocks of life on Earth – and specifically why the DNA-coded amino acids that make up our proteins are all left-handed.

There are two varieties of amino acids, known as left- or right-handed (referred to as S and R). They are mirror images of each other and both exist in nature, as shown for other substances by Louis Pasteur.

Biochemical processes in living organisms use left- and right-handed or ‘chiral’ receptors that template differently with these two forms. The olfactory receptors in our noses, for example, easily distinguish the distinct smells of the otherwise identical molecules (called carvones) of spearmint (R-carvone) and caraway (S-carvone).

Another example is the thalidomide tragedy that was related to the presence in the drug of both the mirror-image forms. One of these (S) was later understood to be harmful.

An important and outstanding mystery is why nature chooses only exclusively left-handed amino acids in forming proteins.

In the late 19th century, TH Huxley and Charles Darwin realised that life may have begun abiotically in a ‘warm little pond’ containing all the elements needed for life, ‘so that a protein compound was chemically formed ready to undergo still more complex changes,’ Darwin wrote.

Much later, in 1924, the Soviet scientist Alexander Oparin returned to the idea of spontaneous generation, suggesting that a ‘primeval soup’ of organic molecules, created by the action of sunlight in an oxygen-free environment, was the basis of all life.

Electric spark experiments subsequently carried out by Stanley Miller in model primeval atmospheres showed that amino acids form in lightning discharges. In contrast to biological systems, these show no preference for either mirror image form and are 50%:50% (racemic) mixtures.

Clay was suggested by the crystallographer John Bernal as a means of concentrating primitive biomolecules onto its surface so as to be available for further reactions. Clays again became the focus of studies more recently when James Ferris showed that they can act as catalysts for the formation of long strands of RNA, which with proteins and DNA are major compounds essential for the origin of life.

In a second paper, also published in Physical Chemistry Chemical Physics, Professor Fraser has extended these ideas to consider amino acids and to try to understand why all amino acids used to make proteins are left-handed.

With colleagues Professor Neal Skipper from UCL, Dr Martin Smalley from York University and Dr Chris Greenwell from Durham University he replaced the cations between the layers making up natural clay molecules with weakly bound organic cations, causing the clay layers to drift apart.
That created an extremely sensitive clay system with sufficient space to insert both left-handed and right-handed forms of the amino acid histidine between the layers.

‘We found that the R- and S-histidine molecules interact differently with the clay surfaces. These clays are abiotically able to select for chirality – left- or right-handedness – as well as being implicated in the abiotic synthesis of RNA,’ Professor Fraser says. ‘Our experiments were the first to show that clay molecules could do that.

‘We also found that the tiny interlayer space some 5nm wide was a very important dynamic region for studying prebiotic chemistry and that the reactions of simple chemicals there leads to the formation both of RNA oligomers and the selection of left-handed amino acids.’

Clays have also been shown by Jack Szostak and others to enable fatty acids to form primitive cells and, interestingly, clays show similar selective behaviour in space, as reported recently by the NASA scientists Glavin and Dworkin.

Amino acids contained in the meteorites Murchison and Orgueil show enrichment in S-amino acids and this correlates with the amount of intrinsic hydrous clay present in these primitive meteorites that are 4.55 billion years old. ‘The amino acid studied – isovaline – cannot be a contaminant as it is not found in terrestrial living systems,’ Professor Fraser explains. ‘We are thus building an increasingly detailed picture of the steps that lead to the origin of life.

‘We are continuing our research next month on the new NIMROD instrument at the ISIS neutron source near Oxford. This will involve amino acids enriched in deuterium, an isotope of hydrogen, and will provide a detailed atomic picture of the way amino acids interact with the layers of clay for the first time.

‘In the long term, this work could have significant applications not only for our understanding of the origin of life, but also in medicine as the design of new mineral surfaces that aid the production of chiral drugs would be of great benefit to the  pharmaceutical industry.’

The first I heard about ‘I'm a Scientist’ was from a link on NERC’s website, advertising upcoming science engagement activities. This sounded like fun: ‘an online forum interacting with school children over a two week period’. I duly filled in the forms and forgot about it. 

In early February, I learnt that I had been chosen as one of the scientists for the two week event in March. The first challenge was to complete an online profile: ‘describe yourself in three words’ ‘who is your favourite band’ ‘tell us a joke’.. hmm.  How am I not going to sound out of touch?

But looking at last year’s entrants, and my new colleagues in the Potassium Zone, I began to realise that ‘being in touch’ was not the point. Instead, part of the object was to show that scientists are actually people, and that we have all found different routes to a career in science.

The other scientists in my zone included a drug specialist at GlaxoSmithKline, a postdoc in Neuroscience at Caltech, a nuclear processing engineer at Sellafield, and a developmental psychologist from the University of Central Lancashire. Now, we were being thrown together in an ‘X-factor’ style competition where the audience were about 300 14-15 year old schoolchildren from 20 schools.

The event itself started slowly. A few questions arrived on the Friday afternoon, but things didn’t really kick-off until the live chats started on the following Monday. And what a day to start: the 7 O’clock news had the first indication of a huge earthquake in Japan and by the time I arrived in work, the scale of the calamity was beginning to unfold. Within a couple of hours, the first live chat session was on.

This was my first time with MSN style messaging; and it wasn’t long before I realised how hopelessly inefficient my typing is. I also didn’t know any shortcuts, and the students had such hugely complicated nicknames: try typing @cocoacrazycicaxoxo at speed! My colleagues in the zone seemed to be able to write an eloquent essay on the workings of the brain in the time it was taking me to say ‘my favourite volcano is Villarrica in Chile..’.

I decided that I would have make up for lost time when answering the questions posted by the students. This settled into a pattern for week 1 - a growing list of questions to answer, that expanded to fill my evenings; and frantic chat sessions during the day. At the beginning of week two, the tempo began to rise: now the students were starting to vote for their favourite scientists – with a vote every day, and evictions at 3pm.

Questions flooded in: not only on science, but on philosophy. Ranging from ‘what's the best question you have ever been asked in your life?’ to ‘Have you ever roasted marshmallows over flowing lava?’ and a whole spectrum of questions following on from BBCs Wonders of the Universe on the Big Bang, entropy and space-time. As the final day dawned, there were just two of us left – and another fifty questions and three live-chat sessions later, I was the last one standing.

Reflecting on the event, it was certainly the most absorbing form of science engagement that I have ever done. The live chats were great for getting conversations going on a whole range of threads - mainly relating to things like 'how do you become a scientist?' and 'what is it like when you are one?'

Some students realised quite quickly that they could join in any of the live chat sessions once they were logged in, and became regular visitors over the next fortnight. The Q+A section was an excellent follow up - with some students taking full advantage to develop conversations over several days with further questions and comments.

By the end, I had answered over 600 questions, thoroughly refreshing my science general knowledge, as well as honing my explanations of what I actually do for a living; and speed-typed my way through over 12 hours of live chat. 

As a zone winner, I now get £500 to spend on a science communication project - so I’ll be off to make some podcasts from active volcanoes!

Professor David Pyle is based at Oxford's Department of Earth Sciences.

Oxford University researchers have linked a surge in the incidence of tick-borne disease in Eastern Europe to poverty levels.

Their study of 14 European countries, published in Parasites and Vectors, associated socio-economic factors in three east European countries with the highest increases in outbreaks of tick-borne encephalitis [TBE]. TBE is a viral infection of the central nervous system caught from the Ixodes ricinus tick.

The scientists attributed the 2009 increases to a reaction to unemployment in countries where pre-existing poverty levels were high. This may have led to a rise in the consumption and commercial use of foods sought in nearby forests, where ticks are found.

‘The bottom line from research is that everyone focuses on the biology of disease,’ Professor Sarah Randolph of the Department of Zoology says. ‘Then we realised it doesn’t rest solely with that but with the other side of the coin - the human exposure to ticks.’

Research in the 1990s by Professor Randolph showed that outbreaks of tick-borne diseases had increased dramatically in many central and eastern European nations. This was ‘likely to have been due to environmental and socio-economic changes associated with the end of communist rule,’ Professor Randolph explains.

Her latest research with colleague Elinor Godfrey has confirmed the link between poverty - as reflected in household expenditure on food - and the prevalence of tick-borne disease. This factor could have an immediate impact on people’s daily activities and behaviour associated with exposure to ticks.

Professor Randolph says: ‘TBE cases were more numerous in 2009 than over the previous five years in almost all countries but the increases were far greater in Latvia, Lithuania and Poland.’ In these nations, outbreaks rose by 91%, 79% and 45% respectively. Outbreaks increased by less than 25% in the other countries studied, which included Sweden, Italy, Estonia and the Czech Republic.

The researchers’ analysis ruled out changes in the weather, such as altered rainfall patterns and variations in temperature with the seasons, as explanations for the surge. Professor Randolph believes the traditional use of forest products in east Europe and commercial opportunities for wild food, particularly in Lithuania and Poland, are significant in explaining her findings.

In addition, the physiological and emotional stress of economic hardship could reduce resistance to disease. Fewer people are getting inoculated because the TBE vaccine is relatively expensive for those on low incomes.

‘Recognition of these risk factors could allow more effective protection through education and a vaccination programme targeted at the economically most vulnerable,’ Professor Randolph says.