The Sceptical Chymist

At the general poster session the other night I was delighted to see the two candidates campaigning for the job everyone is talking about. No, not McCain and Obama, but the two candidates for the president-elect of the ACS. As the biggest scientific society in the world, this is a big job.

As I approached one of the candidates, Josef Michl, I noticed he was chattering to Bob Grubbs (see earlier post). Michl was very keen on sustainability. And this is a broad recurring theme of this meeting. Chemists realise the opportunities they have to help the planet. Of course, chemistry is the underpinning science to the technologies that are being investigated to replace fossil fuels. I can only imagine that in future this theme is going to engulf these meetings even more.

The other presidential-elect candidate had a very firm handshake and free colour-changing pencils. Another Joseph, from Purdue, Joseph Francisco told me about his plans to unite retired chemists and young, keen postdocs to create an ACS-centred bank of expertise. His focus was much more on the business side of chemistry, and in particular small businesses.

Two very different candidates with very different agendas. It will be interesting to see who wins. At the moment I wouldn't like to call it, but the trend towards sustainability gives me the feeling that Michl might just steal it.

Posted by Katharine Sanderson at 11:10 AM | Permalink | Comments (0) | TrackBacks (0)

You travel a good few thousand miles and the last thing you want to see is your boss (no offence Stu). Thankfully, he’s back in the UK happy that I’m here doing all the running around associated with an ACS meeting, but I just can’t seem to get away from pictures of him.

I went to a talk by Sir Fraser Stoddart yesterday at which he received the 2008 ACS Arthur C. Cope award. His talk was a nice run through of some of the beautiful work he’s done (both aesthetically and chemically). Fraser likes to give credit to his old students by putting photos of them up on slides when he talks about the work they did. The Nature Chemistry chief editor, Stuart Cantrill, is a Stoddart protégé and thus the talk was littered with Cantrill references and pictures, to the point where he was acknowledged, alongside Stuart Rowan and Omar Yaghi, as a pioneer of the newly branded area of chemistry ‘mechanostereochemistry’ — high praise indeed.

Fraser even gave Nature Chemistry a mention. Reaching more people than I ever could in my whole week here, he named Stuart as someone who as the founding editor of Nature Chemistry could “considerably influence how chemistry develops in the future”.

And there was me thinking he was just someone who could considerably influence the time at which the Nature Chemistry editors get their next cup of tea! Get the kettle on Stu!

Gav

Gavin Armstrong (Associate editor, Nature Chemistry)

Posted by Gavin Armstrong at 09:00 AM | Permalink | Comments (0) | TrackBacks (0)

I’ve spent most of the last couple of days in sessions organized to celebrate 100 years of the ACS physical chemistry division. They’ve been packed with some real science heavyweights and in general, have have mixed some great 'memory lane meandering' with new results.

Monday started with Ahmed Zewail (Nobel prize in chemistry, 1999) from Caltech. He spoke about advances in visualizing complex structures in 4 dimensions i.e. seeing them change in time. He presented some very interesting images of ZnO nanowires using ultrafast electron methods and visualizing material expansions related to charge carrier density. The talk was interrupted by a little “cross-talk” from another session. The organizers must have set the wireless microphones for two parallel sessions to similar frequencies meaning that every few minutes a presentation from another session was broadcast over the speakers in our session. The freakiest part of this was when Prof. Zewail clicked through to a slide detailing what is known as the “uncertainty paradox”, and with great comedy timing the cross-talking presenter said the word “paradox”. It was as if Zewail had his own sound effects!

The talk was followed by Yuan Lee (Nobel prize in chemistry, 1986) who described his many years carrying out molecular beam studies and Steven Chu (Nobel Prize in physics, 1997) who gave an inspiring but equally depressing talk (if you can have such a thing; I’ll blog more about this later).

Both the afternoon session and the following morning session were filled with more great speakers including Dick Zare, Rudy Marcus and Gabor Somorjai. It was fantastic to see such leading academics present both their seminal and contemporary work but it would have been nice to see a session in the physical chemical division for young academics, similar to the one held by the ACS organic division, which was a great success from what I hear on the ACS grapevine.

Gav

Gavin Armstrong (Associate Editor, Nature Chemistry)

Posted by Gavin Armstrong at 11:07 PM | Permalink | Comments (0) | TrackBacks (0)

I’m going to stick my neck out a bit here, and discuss some chemical biology, even though I wouldn’t claim to be much of a biology expert. Apologies if some of the details are a bit ropy.

This morning, Linda Hsieh-Wilson gave an inspiring talk on her work unravelling the role of the polysaccharide chondroitin sulfate (CS) in modulating neuron growth. Naturally occurring CS is a mixture of compounds, each containing a different pattern of sulfate groups. This makes it difficult to tease out the effects of particular sulfation patterns, but Hsieh-Wilson’s group have made several tetrasaccharides as models of CS, each with one of the different characteristic arrangements of sulfates found in the parent molecule.

They find that only one of these tetrasaccharides (called CS-E) promotes neuron growth in their in vitro studies. Using CS-E as a molecular probe, they’ve now started to unravel the likely biological mechanism of action. It seems that CS-E forms a ternary complex with brain-derived neurotrophic factor and the receptor TrkB. Blocking formation of this complex prevents CS-E-mediated neurite growth.

But CS is a double-edged sword - it can also prevent neuron regeneration after injury. Hsieh-Wilson is now using her compounds to unpick the reasons for this. Her tetrasaccharides weren’t effective substitutes for CS in in vitro models of neuron regeneration, so her team came up with a method to prepare CS-E polymers (containing 25-80 sugar units). Sure enough, these polymers inhibit neuron regeneration, showing that the CS-E sulfation pattern is most likely responsible for the biological effect. Furthermore, an antibody that blocks CS-E activity was able to counteract the inhibition, thus encouraging neuron repair.

Exciting stuff, especially as there is currently no way to stimulate regeneration of damaged neurons. Of course, this is a long way off providing anything that would be therapeutically useful, but just being able to unpick the biological mechanisms that prevent neuron regeneration strikes me as being incredibly useful. And it’s a perfect example of how chemistry can provide tools that answer biological questions.

Andy

Andrew Mitchinson (Senior Editor, Nature)

Posted by amitchinson at 04:44 PM | Permalink | Comments (0) | TrackBacks (0)

I wrote a story yesterday about a clever way to make tiny batteries using a rubber stamp and a virus. It was actually from a paper that came out in PNAS, but one of the authors, Paula Hammond is here at the meeting. She is working with Angela Belcher on some very cool viruses.

The paper outlines a simple way to build up a polyelectrolyte system, and coat a virus onto it, then let cobalt oxide nanoparticles grow on that. Stamp all this cobalt-side down on to a platinum strip, add a thin piece of lithium to the other side and hey-presto! A teeny tiny battery.

In my discussions with others about the work, it seems that people have been playing around with viruses for a while now, but we should start to see a lot more practical applications coming out of this tinkering in the next few years.

Posted by Katharine Sanderson at 01:57 PM | Permalink | Comments (0) | TrackBacks (0)

I’ve been attending so many interesting sessions that it’s been difficult to find time to blog, but I’m going to redress the balance now. First off, I just wanted to mention a terrific talk yesterday from John Bercaw, which gave an update on his work on the mechanism of the Shilov reaction. If you’re not familiar with this reaction, it was one of the seminal discoveries that underpins modern C-H activation chemistry. Unfortunately, it’s stoichiometric, but Bercaw is hoping to make a catalytic version that will provide a practical method of converting alkanes into alcohols. That goal is still some way off, but he’s found some promising water-compatible catalysts (water compatibility will be essential) that look like a good step in the right direction. I was particularly impressed by his obviously meticulous approach to research - if anyone can crack this problem, then he can.

Then yesterday afternoon, I attended a star-studded symposium that celebrated the 100th birthday of the organic chemistry division of the ACS. With speakers such as David MacMillan, Ken Houk, Larry Overman, K. C. Nicolaou and Barry Sharpless, this was the must-see event of the symposium, and the massive ballroom venue was packed. Befitting the anniversary theme, each speaker gave their perspective of historical advances from their fields of interest.

So how do you pick out a highlight from such an illustrious line-up? With difficulty, but my favourite speaker was John Roberts, the emeritus professor from Caltech. At 90 years old, he’s certainly the most senior speaker that I’ve seen at a conference. I have a fondness for the history of chemistry, so I lapped up Roberts' stories of his early career, and his reminiscences about the leading figures of the time. For example, R. B. Woodward was described as having three trademarks - he always carried a cigarette, always used a yellow pencil and invariably dressed entirely in blue. Other snippets included the details of Roberts’ work during the Second World War, when he was co-opted onto a project to find a way of extracting liquid oxygen from air at low pressure (because airplanes at the time carried oxygen tanks, which made them rather vulnerable to fires).

Looking back at his project work as a student, Roberts commented that he was lucky in being able to work on several completely different areas. Nowadays, he commented, graduate students specialize early on, and so they miss out on the benefits of a diverse practical training. The solution, he says, is to provide opportunities for undergraduates instead. In this respect, he feels that summer-school research opportunities for undergraduates are essential. Do any of you think that grad students are forced into specializing too soon?

Andy

Andrew Mitchinson (Senior Editor, Nature)

Posted by amitchinson at 01:30 PM | Permalink | Comments (0) | TrackBacks (0)

Last night was the poster session. It was late, I was jet-lagged, tired and emotional, but I dutifully showed up, if only to get my free beer. As ever this was a really well-attended event. It's impossible to see everything so I decided to pick some of my favourite titles for you to muse over. They show the amazing breadth of this meeting, and some of them actually make chemistry sound, well, really interesting.**

Impact of thermal and nonthermal processing techologies on quality of apple cider (one close to my heart)

Lanthanide pyrone and pyridone complexes for the treatment of bone density disorders

Reinvigorating the chemistry curriculum with Fourier-Transform Nuclear Magnetic Resonance (FT-NMR) spectroscopy

Measurement of the contact angle of a water droplet on a flat surface

Heavy metal accumulation by common garden plants: A chemical and spectroscopic approach

** I'm not saying that chemistry isn't interesting, by the way. I love chemistry, but sometimes it is hard to persuade others not involved in the field.

Posted by Katharine Sanderson at 11:26 AM | Permalink | Comments (0) | TrackBacks (0)

Some people have all the bad luck. I was recommended to go this morning to a session on self-replication. Sounds cool, I thought. I bet it will be busy...

But I was very wrong. Where was everyone? The recommendation turned out to be right, and I really enjoyed Douglas Philp's talks about self-replicating systems, but the room must have had about 15 people in it. I didn't get it, so I asked Philp how come he had failed to pull in the punters. "I was up against Bob Grubbs," he said.

Ah, it all becomes clear. That's bad luck I said. Grubbs is a Nobel prize-winning chemist from Caltech who is a giant in the catalysis world. He even has his own catalyst.

Poor Doug, I thought. Still, better luck for his next talk this afternoon. Nope, it seems the Philp brand of chemistry will fail to reach the masses once more. This afternoon he is up against Barry Sharpless, also a Nobel prize-winning chemist, from Scripps, who has more than one eponymous reaction.

Ouch.

The message to Doug Philp, and anyone else landed with these unfortunate timetable clashes is clear: you're going to have to get a reaction or a catalyst named ofter you. Or you're going to have to win the Nobel prize in chemistry. Preferably both.

Better luck next year, eh?

Posted by Katharine Sanderson at 04:28 PM | Permalink | Comments (0) | TrackBacks (0)

A few weeks ago I wrote a news story about some work done by Dan Nocera at MIT. He's managed to make a very simple catalyst that can generate oxygen directly from water - so helping those people trying to mimic photosynthesis and save the world's energy crisis.

At the time Nocera wasn't sure what the mechanism was for the formation of the cobalt catalyst. In today's talk he confirmed what he had thought then - that the cobalt gets oxidised all the way to its +4 oxidation state. He was also very confident in the technology he is developing. "I guarantee in under five years you'll see this," he said. Companies are coming out of the woodwork, he says, to develop a functioning, practical system.

Other big claims he made were that in a system based on his catalyst cuold produce enough fuel to run a typical house for a day in just two and a half hours. This is big talk, Dan, I look forward to it becoming reality.

Posted by Katharine Sanderson at 01:46 PM | Permalink | Comments (0) | TrackBacks (0)

I had a slight deviation from the ACS yesterday while I finished up writing a story about trees that can absorb organic nitrates and turn them into amino acids. But seeing as in that single sentence I spotted at least four chemistry-related words, I thought this would be a good place to write about the research.

I shan't go into loads of details, because then you might not go and read the story (and I can't believe anyone would miss out on the chance to do that), but the news here is thus: trees, well known to gobble up inorganic nitrogen compounds, can also take up - and use, more importantly - organic nitrates that are the products of NOx emissions and the volatile organic compounds that trees spew out.

It's not yet clear whether this mechanism might actually help to alleviate NOx pollution, and at the same time increase photosynthesis thereby locking up more carbon. If that were the case that would be a very good news story indeed. It looks more likely that this effect is dependent on local conditions. And as the author Paul Shepson told me, even if the mechanism does help clean up the atmopshere a bit, the better solution is to stop the emissions in the first place.

Posted by Katharine Sanderson at 01:28 PM | Permalink | Comments (0) | TrackBacks (0)