Laura Howes


Sometimes people like to moan that chemistry doesn’t get enough media attention, but we have news to counter this claim. Our colleagues have let us know that this weekend the BBC World Service will be broadcasting an episode of The Forum, which was recorded last week at the RSC’s ISACS12 conference, Challenges in Chemical Renewable Energy.

Quentin Cooper hosts the programme with Daniel Nocera of Harvard University, Clare Grey of the University of Cambridge, Carlos Henrique de Brito Cruz of the State University of Campinas and Jim Watson of the UK Energy Research Council. The panel will discuss the work in their areas of expertise and future challenges for renewable energy as a whole. If you want to listen in, the programme will be broadcast at 23.06 GMT on Saturday 14September, 10.06 GMT on Sunday 15 September and 2.06 GMT on Monday 16 September and you can find out when this is in your local time at: http://www.bbc.co.uk/worldservice/programmeguide/.

It will also be available to listen on the iPlayer shortly after the broadcasts have finished at http://www.bbc.co.uk/programmes/p01g94yj. Make sure to let us know what you think.

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

cannabiYesterday evening, over dinner, my friend and I couldn’t help but overhear a man on another table espousing the benefits of cannabis. Over a tiramisu, he stressed how cannabis can cure all ills including cancer and Alzheimer’s (There is some pre-clinical evidence, for these claims, but not all of the literature agrees). What our pro-cannabis lobbyist failed to mention, however, is that the modern cannabis is increasingly ditching the health giving cannabinoids in favour of more and more of the psychoactive tetrahydrocannabinol (THC). (more…)

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Did life come from Mars? Chemistry is in the news this week, with Steven Benner’s announcement that the science points to life beginning on Mars. Of the reports I’ve read, only the Smithsonian seems to have spoken to Benner, the rest seem to come straight out of the press release.

To give the executive summary: when organic compounds are given energy (such as from the Sun or geothermal sources), they can decompose into a gloopy mess that Benner calls tar. These organic compounds can be stabilised by addition of boron, and the newly stable compounds can be catalysed into more complex structures (including ribose) by molybdenum. Simple enough chemistry and nothing new, so where do the Martians come in?

If you read the abstract for the talk, which is at a geochemical conference, (the Goldschmidt conference in Florence), it becomes a bit more clear. The discussion surrounds mineralogy and early planetary environments. Essentially, what was the Earth like billions of years ago, and could that have supported the reactions that led to life? Herein lies the rub – Earth was anoxic and very, very wet at the time the chemistry of life is thought to have formed. All that water would keep the soluble boron too dispersed to stabilise the organics, and molybdenum wouldn’t have existed in the right oxidation state to catalyse the required reactions.

So what about our near neighbours? Benner argues that the Martian climate at the time would create ideal conditions to form carbohydrates, including the vitally important RNA. (more…)

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

This evening, at the ISACS Challenges in Chemical Biology event in Boston, I was part of a conversation suggesting that the concept of chemical biology needed a rebrand. The kids aren’t into chemical biology any more, that scene’s old, man. Of course earlier in the day, I’d been discussing how ‘molecular biologists’ have become ‘chemical biologists’ as the understanding of chemical mechanisms in biology has improved.

The truth is that over the last 48 hours I’ve watched talk after talk illustrating how the mechanics of life are molecular. They are chemical. Bacteria talk to each other using small molecules and peptides that interact with specific residues in a protein, that induces a conformational change, which changes the protein’s available residues within the cell which… and then… and that activates the hydrogen of… etc. The chemical modification of histones by enzyme x alters the reaction landscape of genes by… and so on. (more…)

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

I’ve been performing some internet searches that could cause red flags in the office, but on the other hand it’s a story of citizen science and lab safety. There is a growing trend for people to perform solvent extractions at home, but what they’re extracting is tetrahydocannabinol, the active ingredient in marijuana, and they’re using highly flammable butane or isopropyl alcohol for the extraction.

Illustration of cannabis plants. Hermann Adolf Köhler (1834 – 1879)

Now there’s a bit of me that’s quite admiring of these home grown chemists, methodologies are available online and improvements are shared. However, in my experience, the venn diagram of people who are strongly pro-pot and people who are anti ‘scary chemicals’ has a pretty large central cross over. That leads to a lot of discussion about how smoking ‘hash oil’, the resinous product of these home extractions, is ‘more pure’. I’m not sure I agree, it’s still a mixture of compounds rather than pure THC, and despite claims of the oil being 90% THC by these home extractors, my survey of the literature suggests something topping out at 65%. And what about the additives in the solvent itself? But I’m not here to niggle over how good these extractions are, rather to make a point about how a little knowledge can be a dangerous thing.

(more…)

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

We all love a cartoon. Animation is a fiddly and time consuming but I can remember the fun of making flip books. Taking it up a notch, IBM researchers have some more expensive kit than my notepad and pen, and now they’ve used it to make an ‘atomic movie’.

Scanning tunnelling microscopes can image individual molecules on a metal surface, and drag those same atoms and molecules around to make letters and images. Stop-motion animators today make an image, take a picture, change the image slightly, take another picture, and repeat that cycle until they have enough frames to make a film. Put the two together and you get ‘The boy and his atom’ premièring today on YouTube and certified by Guinness World Records as the smallest ever movie. The cast ? Carbon monoxide molecules.

In total the movie is made of 242 frames and I love how you can see the ripples in electron density that surround ‘Adam’ and his bouncy little friend. I’d love to know how long the entire process took, not just the imaging but the tidying up of the image and the putting it together. Using such big machinery cooled down to low temperatures to keep the molecules where they’re put is pretty expensive and labour intensive, so I’m not sure atomic animation will be taken up by Hollywood just yet. But as a demonstration of the control IBM now has over single atoms and molecules the video is pretty neat. IBM has also released a video with some more behind the scenes detail which you can watch here.

My verdict? Well I just tried to make a flip book of a thumbs up, but I think I’ll leave the animation to the professionals. Good job. What do you think?

Laura Howes

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Gecko

One of the participating tokay geckos. Photo: Ethan Knapp and Alyssa Stark

I love a good gecko story, and I love how the cute little critters can climb up most things but would apparently struggle with my non-stick frying pan. Now I’ve found out that if my frying pan was still wet from the washing up Mr Gecko would have a better chance of holding on.

There is a serious side to this science. Hundreds of systems have been developed mimicking the adhesive power of gecko toes and all rely on creating a large surface area that can get in contact with whatever surface you want to stick to using van de Waals forces to do the rest. Understanding how different surfaces affect adhesion is obviously important and it’s been anecdotally known for a while that as well as struggling with Teflon, geckos can’t stick to wet glass despite their feet being superhydrophobic. In rainforests, things can get quite wet so how do the geckos manage?

To test this out Alyssa Stark‘s lab at the University of Akron, Ohio, placed geckos on different surfaces to investigate when the geckos slipped and when they stuck. To get more data than slip versus stick, those little geckos were fitted with harnesses and slowly pulled off surfaces using force meters to record the gecko adhesion values. If ever there’s a day you’d have liked to have been in someone’s lab, the day harnessed geckos were slid around for science has got to be up there (at least for me).

The findings are, in part, to be expected. Wetting surfaces usually makes them more slippery for geckos but it’s only wet glass that causes a real problem – hydrophobic surfaces that were wetted could still be clung on to as the lizard’s hydrophobic feet helped get rid of the water and form a contact with the dry surface beneath. So the lab work confirms that wet leaves shouldn’t be a problem. The exception, which also contradicted the Akron group’s modelling, was PTFE, or Teflon. Wet Teflon, it seems, is much easier for the geckos to hold on to. The why is not certain yet though, so I for one am looking forward to more gecko science, ideally with videos…

Laura Howes

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

mountain gorilla

Are you what you eat Mr Gorilla?

It reminds me a little of a certain TV ‘Dr’ obsessed with poo, but US scientists have been busy analysing the faeces of mountain gorillas. So have the gorilla’s been following a healthy diet, are they what they eat and why oh why would you be rummaging around in gorilla poo for your day job?

Well it turns out that tracking and understanding the diets of wild animals can be tricky. You can observe them eating, or rummage around in their poo for what remains, but that will only give you a snap shot: larger trends can be difficult to spot. Scott Blumenthal at the University of New York and his colleagues used isotope ratios to track how the diet of mountain gorilla’s shifts with the seasons. Using the change in 13C values the group showed that while gorilla’s usually eat foliage, when fruit is available gorilla’s prefer it and so change their diet. By increasing the amount of fruit they eat the gorillas also increase the amount of 13C they ingest because of the fruit’s position in the canopy of the forest. Plants down towards the ground tend to rely on carbon that has been taken up from the soil and has already been metabolised and so lost much of its 13C. (more…)

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Probably best enjoyed without liquid nitrogen

Reports are coming out that an 18 year old woman has had her stomach removed after drinking a ‘nitro’ cocktail given a smoky effect using liquid nitrogen. It seems that outside of labs liquid nitrogen is proving quite the star turn… from making ice cream in Camden, to being used in cocktails around the country.

These cocktails seem to come in two types, either a small amount of liquid N2 is used to cool the drink without dilution and with added smoky effect, or much more N2 is used to whisk up a frozen cocktail, more N2 is then poured over for, again, that smoky effect. Basically, everyone wants a cocktail that looks like it comes from the set of an Addams family movie. (more…)

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Phosphate uptake protein

Distortion of the protein

Another nail in the coffin of the arsenic life story has been published suggesting that GFAJ-1 does not in fact metabolise arsenate, but instead is very good at distinguishing the poison from phosphate. Earlier this year, two papers found that despite earlier claims, the bacterium did not in fact take up arsenate, the new paper explains in more detail why.

Publishing in Nature, Dan Tawfik and colleagues decided to investigate how exactly GFAJ-1, and other bacteria that live in arsenic rich environments, survive. Can they distinguish between the two anions, and if so, how?

The trick, suggests Tawfik, is in the peristaltic phosphate binding proteins which are highly tuned in GFAJ-1. Although arsenate ions are only a little larger than phosphate, that size difference is enough to distort a low energy hydrogen bond and stop arsenate uptake (see left).

I can’t help but wonder, have we finally laid this to rest, or will more papers refuting GFAJ-1′s ability to metabolise arsenate keep coming out for a while yet? If they keep getting their authors in high impact journals, you can see why anyone working on applicable research might want to join in.

Laura Howes

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Next Page »