January
Chemistry World Podcast - January 2013
1:05- The anti-ageing properties of olive oil can even be extended to buildings
4:00- Potatoes have been bred with lower levels of acrylamides
7:25- David MacMillan tells us how Princeton's new chemistry building is catalyzing new interactions and discoveries
15:40- DNA building blocks - not unlike a certain children's toy - can be used to make complex shapes
19:16- A zeolite 'bouncer' can discriminate between methane and carbon dioxide
21:58- John Rogers discusses his nanofabrication work
29:10- Two recent papers show water acts as a surprisingly active reaction promoter
32:36- Was polonium-210 responsible for the death of Yasser Arafat?
36:00- Trivia: How much carbon dioxide is contained in a standard bottle of champagne?
(Promo)
Brought to you by the Royal Society of Chemistry, this is the Chemistry World Podcast.
(End Promo)
Interviewer - Chris Smith
This month nanoscale brain interfaces for epilepsy, so for potatoes for frying, did Yasser Arafat die of polonium poisoning and how to get a chemistry department cooking.
Interviewee - David McMillan
What I decided to do was, we had this beautiful new cafe, they brought in one of the best coffee makers to supply it and my feelings was I wanted everyone to turn there and get caffeinated and interacting with each other and talking with each other.
Interviewer - Chris Smith
That's right, you have to give them free coffee and where is this wonderful working environment, well we'll find out shortly.
(Promo)
The Chemistry World podcast is brought to you by the Royal Society of Chemistry; look us up online at chemistry world dot org.
(End Promo)
(1:05 - The anti-ageing properties of olive oil can even be extended to buildings)
Interviewer - Chris Smith
Hello. , Happy New Year, I am Chris Smith and also here for the January 2013 edition of Chemistry World are Patrick Walter, Phil Broadwith and Laura Howes who has been finding out how olive oil doesn't just make people live longer, it could even help to preserve old buildings.
Interviewee - Laura Howes
Yep, it's going to help your York Minster protect itself against acid rain.
Interviewer - Chris Smith
So, they're really turning olive oil into preservatives for building?
Interviewee - Laura Howes
Yeah, they're actually using oleic acid which is one of the major components of olive oil and in combination with a trimethoxylsilane compound and basically making a hydrophobic coating for York Minster and other limestone buildings that we're protecting.
Interviewer - Chris Smith
How does it work? What is it doing?
Interviewee - Laura Howes
So, Karen Wilson at Cardiff University has been working with conservatives for York Minster, actually try and make this coating. The problem is that quite a lot of people are working on hydrophobic coatings, so coating that repel water and there are various reasons for that. Water is a problem for two reasons, first of all acid rain falls on the Minster, falls on the limestone and helps it to dissolve it away but also then some of the sulfur oxide compounds can then get absorbed into the rock and then when water falls on it again, they can leach back out and create acid once again. So, it's an ongoing process and that's the reason why you want a hydrophobic coating to try and protect the rock, not only from the acid rain but actually from water that would perpetuate the problem.
Interviewer - Chris Smith
Why did they settle on this particular formula?
Interviewee - Laura Howes
Well, people have been making coatings before but the problem is that they're not breathable. So actually what you end up doing is ceiling the rock off from the water but also actually trapping things aside and then you can get all sorts of, you know, moulds growing and problems within the rock. But because of the structure that this oil makes with the silane it actually helps breathe. So, air can get in and help the actual rock breathe and the building breathe.
Interviewer - Chris Smith
And presumably water molecules can move in and out, it will equilibrate.
Interviewee - Laura Howes
And water molecules, yeah, yes, but it won't soak through.
Interviewer - Chris Smith
Particularly acid rain in the form of droplets are not going to get in.
Interviewee - Laura Howes
Yeah exactly.
Interviewer - Chris Smith
It's not going to do damage though, because I think that's the thing that people worry about with conservation, I think when you look at modern day works of art and things that people have tried to conserve "in the past."
Interviewee - Laura Howes
Yeah.
Interviewer - Chris Smith
Actually conservatives have done more damage, in their own way.
Interviewee - Laura Howes
Yeah, and Wilson and the York Minster conservators are very honest about this, I mean, they've tried things before and it has caused problems as we were discussing, They're actually doing quite a lot of work at the moment to actually understand what's going and testing it and taking rock samples and putting it through various tests and make sure, but it's looking good.
Interviewer - Chris Smith
Does it show? When it is on, can you see it?
Interviewee - Laura Howes
No, see I thought you would have some sort of oil or flick of a shiny.
Interviewer - Chris Smith
It would be like a Brylcream for churches, we can't see it.
Interviewee - Laura Howes
Precisely it's pretty invisible but quite useful.
(4:00 - Potatoes have been bred with lower levels of acrylamides)
Interviewer - Chris Smith
Well, from one kind of wall to another. So, olive oil good for frying things or maybe not, Patrick because of acrylamide. We know that this can be carcinogenic but scientists are trying to make potatoes that won't give us cancer.
Interviewee - Patrick Walter
Exactly, so it's been ten years since the European Food Safety Body started looking into acrylamide and they've just recently found that very little has changed. So, what one group is doing is looking into different potato varieties to try and work out where the acrylamide is coming from when it's fried.
Interviewer - Chris Smith
So, where does acrylamide come from when we fry, is it just potatoes or do other foods make it too?
Interviewee - Patrick Walter
Lots of other foods do it. So it's kind of a golden colour, you see food with that rich golden colour that looks so appetizing then that food is going to have some acrylamide in it, it's all about the Maillard reaction. When you get an amino acid like asparagine reacting with some sugars at high temperatures that is when you can get the formation of acrylamide. So, so far they've had some luck in driving down acrylamide levels in things like cereals, cereal-based things, children cereals, crisp breads. But this is quite easy, because cereals, wheat that kind of things, they've very simple profile that tells you where the acrylamide is coming from.
Interviewer - Chris Smith
But it's not trivial because asparagine is an amino acid; is also protein, so you can't really remove it with any ease from a complex organism like a potato.
Interviewee - Patrick Walter
That's very true but what they're really worried about is free amino acid. So, it's free asparagine, it's what they're particularly worried about in potatoes and also in wheat, so for wheat it's quite easy to deal with, because all that matters is the asparagines. So, all we need to do is to find a low asparagine variety of wheat and then you kind of got your problem solved there. You have much low acrylamide when you're frying, backing, cooking.
Interviewer - Chris Smith
So, why can't we find a low asparagine variety of potato?
Interviewee - Patrick Walter
So, what Nigel Halford at Rothamsted Research is doing is part of like a big project, integrating a low acrylamide potato, they looked at nine varieties of potatoes for things like making crisps and French fries and what they found is that acrylamide production during frying and cooking is very dependent on a whole host of factors. Asparagine has some effect, different sugars, so glucose particularly is linked to it. But it's very difficult to, kind of, link it all up because the relationship is very complicated. The levels of asparagine, the free amino acids, the glucose can actually change during storage. They can go up and down, because tubers in a way are still like living and they go through cycles of like getting ready to grow again, to sprout and these kinds of things, so the changes are going on inside the tubers all the time.
Interviewer - Chris Smith
So, what is the bottom line? Can we lock away this asparagine or not?
Interviewee - Patrick Walter
They say the things that do as a target variety are, sort of, best at the moment. So you might not have heard of Lady Clare and Saturna varieties, they're not ones you're going to find on your supermarket shelves. So things like Maris Piper didn't turn out very well, but these varieties which are used for making crisps were much better.
Interviewer - Chris Smith
So, already they've lost their crisps then?
Interviewee - Patrick Walter
Yeah, crisp gives the way for weight.
Interviewer - Chris Smith
So, we put on a stone or two a week
Interviewee - Patrick Walter
Gain loads of weight ,you don't need to worry about the minute amounts of acrylamide and I think it's important to say that acrylamide, it is only sort of a potential carcinogen and there's still very tiny amount. So, it is much more important to eat healthily than it is to worry about tiny amounts of this toxic chemical.
(7:25 - David MacMillan tells us how Princeton's new chemistry building is catalyzing new interactions and discoveries)
Interviewer - Chris Smith
A chip of the old block boom, boom. Thank you Patrick. Chemists in Princeton are celebrating the discovery of a new catalyst that has dramatically boosted their research output, collaborations and well being at work, what is it? Free coffee! And a new bespoke Chemistry building costing a quarter of a billion dollars. But Professor of Organic Chemistry David MacMillan says, it's worth every penny.
Interviewee - David MacMillan
Very large, five levels, as you look out it looks predominantly built of glass, and a very large central atrium with all the lab space on one side of the building and the office base on the other side connected by glass bridges that work at every level and really beautiful quartz like spiral staircase as a walk up in the inside. It's a really beautiful airy light space and everyone who comes in it, are taken back by both the look of it and the size of it, so it's a really a, really great new building.
Interviewer - Chris Smith
Now, what motivated you to invest, what I guess, must have been a pretty substantial price tag in building that?
Interviewee - David MacMillan
Basically, it came down to the fact that Princeton University also, Wageningen University, sorts of private University. It is university that believes strongly in expanding its resources and making sure that every department is extremely strong. We had a previous building that was one of the oldest in the United States; it was built in the 1920s. The University decided that it really wanted to continue to press the chemistry department to be one of the premiere places around the world, and so they decided to invest somewhere close to half a billion dollars on the chemistry of which I think it was probably close to quarter of a billion dollars which went to the production of this new building and their belief, the administration's belief is that if you're going to do something well, you really have to set up the foundations and the foundations has to be making sure that everyone's working environment is really fantastic.
Interviewer - Chris Smith
What are the chemists working in the building think, because I guess if you went up to the average chemist and said in your view what do you need in order to do your job really well, they would say, loads of grant money, some ready fancy equipment costing half a billion quid and that's about it. What was the attitude when you said we're going to spend this amounts of money just on a building and some fun new offices for you to hang out here
Interviewee - David MacMillan
Yeah, well, from our perspective it was actually received very well, and it was received very well, because we were, the moment where we decided that we really wanted to help this very large reintegration of the department and I think because the administration in our case came back and said, we want you spend that much money on a building but we also want to spend an equal amount of money on bringing people here and further in the department, in terms of the academics and the resources, because if it is put together as a package, people who work were actually were very happy with it. Many of the people are actually in the department and in the new building, I think everyone here really appreciates the impact of what being in a building actually does for you. When you're basically surrounded by people who are genuinely happy, to walk in the place of work every day and walk around not just feel good about it but feels proud of it and excited about being there and realizes a space which really leads to tremendous amounts of interaction between people that is something that adds a completely different dimension to functioning as a department, just as ability to be able to visually see each other and bump in each other and making sure that there's no wall separating each other, that really we get to see each other a lot, that makes a huge difference to how the department actually functions.
Interviewer - Chris Smith
Someone said the coffee is free.
Interviewee - David MacMillan
The coffee is free, yeah, that was one of my thoughts, one of the things I wanted to do was to make sure we have those people and we can see each other and they got really interacting and there's a lots of collisions going on if you want, you are looking at that in a geeky way. And so what I decided to do was build this new beautiful cafe, they brought in one of the best coffee makers to supply it and one of my feelings was I wanted everyone to turn there and get caffeinated and be interacting with each other and talking each other and the easiest way you do that like with every co-worker in the department and for life actually, we decided to make sure that co-workers come back and in the future, basically make it their all coffees for free and that's had a tremendous impact. People are very closer in fact, you can go in and you can get your coffee, all that jazz and move and bump in with people and there is also the reason that people will sit and talk to each other and the amount of collaboration and the coffee has not been the main reason, but it certainly helps in with the number of interactions and collaborations that are going on in the department is just very large and that's one of the major things we wanted to achieve.
Interviewer - Chris Smith
So, the coffee is a catalyst, if you like, but this is a serious point, isn't it, that actually if you've got an environment where you're bringing people who are multidisciplinary, united by common subject together, there will inevitably be people who are working on something that could provide another worker with a solution to a problem they're grappling with or at least part of the solution.
Interviewee - David MacMillan
Absolutely I mean, one of the things I think people forget is scientists get excited about science and we love what we do but we also love seeing what other people do. And if you have to sit in your office and read the computer and trying to figure out from a magnetic strip what someone else is doing, the typical, I think, human response is to switch off from that and not to attempt it. When you're spending time looking at someone face to face and join a social interaction and you start to talk about this is what I do, most people will immediately fine-tune how to describe the science or the research such that the other person can understand it, that's a very normal human communication role and doing that gets both people excited and people talk immediately in a sort of creative and innovative way will start to think about how we can add our impact to what the other person is doing. That was one of our key objectives with the building and also the coffee and a lot of things that we are doing, to really sort of appreciate this idea of making sure that people, away from one another, away from their office actually sat and talked with each other and they do that in a very normal way.
Interviewer - Chris Smith
This works very well. If you're in the privileged position of being able to spend a quarter a billion on a building and you have the sites to do it with. What about universities that are landlocked or there in the middle of the city and they don't have a capacity to do this. Does that mean basically it's the end of the road for their chemistry department, is there anything they could do to rescue their positioning, I mean they can subscribe to the same advantages that you're reaping with this?
Interviewee - David MacMillan
I mean, that's a great question, it's also a realistic question and it's a tough question for me and it's easy for me to say this is fantastic, this is wonderful when you have all these resources to go off and expand it. My take on that is I actually go to five different universities on paper and in terms of their infrastructure of their buildings, whether they are in studies or not, does it look pretty similar on paper but when you meet those people, you'll see five completely different culture in those departments and my view is, that really comes down to the determination of the individual faculty to develop these collegial interactions. The way that you do that is, you basically, in my opinion, it's almost like you have to introduce the idea of like having a special glass into your building that you make ways to make sure that people are seeing each other whether that's through coffee or lunch time meetings or whether the faculty gets together to discuss all research, departmental or colloquiums, with the students or different groups really get a chance to interact with each other and they get a chance to meet and think and collaborate, that's an enormously important thing. So, from my view point is to think of collegiality first and then to thank you for how you would utilize your own infrastructure to execute or not. I think it's certainly not a trivial thing to settle off. This is certainly something to think about and certainly something to care about.
(15:40 - DNA building blocks - not unlike a certain children's toy - can be used to make complex shapes)
Interviewer - Chris Smith
David MacMillan, so the take home message is that Princeton Academics will do absolutely anything for a free cup of coffee. They'll even talk to each other. Still to come in this edition of Chemistry World, molecules that can sieve gases and nanoscale electrodes that can sit harmlessly on the brain surface to record nerve activity and even stop epileptic seizures. First though to something else very tiny, DNA and what you can make with it, Phil.
Interviewee - Phillip Broadwith
Over the course of the podcast, we've probably talked about DNA nanotechnology quite a few times but this latest advance takes it a kind of step further and turns DNA into essentially Lego blocks. Normally in DNA origami if you want to make shapes out of DNA, you get one long strand from a phage, a virus that infects bacteria and then you get lots of little strands and kind of staple it together into the shape that you want.
Interviewer - Chris Smith
When you say staple, do you mean the little strands are addressed on to the big strand by using the fact that certain DNA letters bind to other DNA letters?
Interviewee - Phillip Broadwith
Yeah, so the little strands have short sequences that match up with sections on the bigger strand and they kind of tie them together. They'll bind to the right bits and tie them together into a big shape.
Interviewer - Chris Smith
So, it sort of pulls the DNA long strand into a certain shape because the small bit binds in one place and another place.
Interviewee - Phillip Broadwith
Yeah.
Interviewer - Chris Smith
It pulls it into various tangles and loops and shapes that you can predict, so you know where to address them to.
Interviewee - Phillip Broadwith
Yeah, absolutely and there's lots of people who've developed kind of software for working out which sequences you need to do, but what William Shih and Peng Yin have been doing at Harvard University and Massachusetts Institute of Technology in the US is taking a slightly different approach, rather than having one long strand stuck together with lots of little strands, they just take a whole variety of little strands and make them stick together and each little strand is a bit like a Lego block. It has two bits that are kind of analogous to the studs on the top of the block and two bits that are analogous to the holes on the bottom of the block where other strands can fit in and be complementary.
Interviewer - Chris Smith
So, what's the benefit of doing it that way over doing it the way you previously mentioned of just taking a long bit of DNA and winding it in a certain way?
Interviewee - Phillip Broadwith
Well, what they've done is make a cube of these blocks where each block can only fit in one place within that cube and then if you take out certain blocks from the cube, you can sculpt that block into any shape that you like.
Interviewer - Chris Smith
Oh I see! So using the genetic sequence which is intrinsic to the little pieces, they will address themselves of it together only in one particular way but by leaving some of them out, you can instead of having a solid brick you could have something rather exciting that you do find in a Lego set, those spoke pieces and then you build those together.
Interviewee - Phillip Broadwith
In the papers, we've got pictures of things that look a bit like a space ship. In theory anything that you can fit into the original cube in terms of shape, anything that you can imagine bringing, you can basically put the right blocks together under the right conditions and they'll self-assemble into that shape.
Interviewer - Chris Smith
But how do you make a complex thing like a rocket, so that this block knows that it's got to stick to the one next door and the one next door, don't you run out of enough unique addresses on the DNA sequence to make them glue together the right way?
Interviewee - Phillip Broadwith
Well, each block is made from 32 bases, so each kind of element if you like, each hole or stud is 8 bases, so you've got 4 to the 8 different combinations, which is quite a lot, so that's enough to make this 10x10x10 cube where each block is completely unique and it will only fit with the ones next to it.
Interviewer - Chris Smith
Ingenious, so when you're not making space ships with it, what could we actually do with this?
Interviewee - Phillip Broadwith
Well, at the moment this is really a sort of in proof of concept but the group has made over a hundred different shapes. It really takes DNA nanotechnology to the next level, it really opens it up to a whole lot of shapes that were just not possible before.
(19:16 - A zeolite 'bouncer' can discriminate between methane and carbon dioxide)
Interviewer - Chris Smith
Talking of opening things up, Laura you've got a story about a molecular trap door, but not a DNA one.
Interviewee - Laura Howes
Not a DNA one, no I think it's a bouncer outside a club, you know, you're not covered in, you're in-traders, you know none of that here.
Interviewer - Chris Smith
Do people say that to you, in your youth?
Interviewee - Laura Howes
I didn't go to those sorts of clubs.
Interviewer - Chris Smith
Okay, well how do these bouncers do their job at a molecular level, what are they discriminating against?
Interviewee - Laura Howes
Okay, so not actually to the bad clubs, we're talking about zeolites which are porous molecules basically silicon oxygen clays, porous and we've known for a while that they can be used like molecular sieves and for gas storage, because they've got this porous structure.
Interviewer - Chris Smith
So, they can sieve out certain molecules and select in favour of others, allowing them through.
Interviewee - Laura Howes
Yeah, and up until now, we basically thought it was just a size effect, just the size of the pore is what allows some molecules in and other molecules out, but what Paul Webley at the University of Melbourne in Australia has found is that it can actually be a bit more subtle. So the bouncers that we're talking about are caesium ions, caesium cations that sit in the pool and if you're say, carbon dioxide molecule, now the carbon oxygen bonds are slightly polarized which means the oxygen has got slightly more electronegativity and the caesium cation is obviously positive, and so because you didn't give some of your, the oxygen sort of donates a bit of its electronegativity a bit of that charge to the caesium, it moves it allowing the carbon dioxide to get through.
Interviewer - Chris Smith
So, if we took a non-polar molecule of roughly the same size, like a methane molecule CH4, would that not move the caesium then?
Interviewee - Laura Howes
Exactly. That's what they found. So the methane can't get in, it is not allowed into the club, it's where in the training in a sort of analogy.
Interviewer - Chris Smith
So, you could use this then to selectively sieve CO2 away from a methane CO2 mix or similar.
Interviewee - Laura Howes
Yeah exactly. We often talk about flue gases and trying to remove carbon dioxide flue gases and then may be take in the methane and, you know, reusing that especially because methane is more of a greenhouse gas than the carbon dioxide. So this is an ideal application potentially for doing that.
Interviewer - Chris Smith
And now we know how it works, can we train it or manipulate it so that we can say, we don't want methane, but we do want another molecule or something like that? Could we make it selective, even more selective?
Interviewee - Laura Howes
Possibly, I mean, that's one of the other thing they are obviously looking at the moment is making the thing more selective and trying to probe exactly what you can do and what you can change to make different molecules go through making it really, really selective, that sort of thing.
(21:58 - John Rogers discusses his nanofabrication work)
Interviewer - Chris Smith
Laura Howes and despite what she says she definitely did go to those sorts of clubs because I saw her there working behind the bar. Nanotechnology now and to a true pioneer in this field, who is making devices so small that they can be embedded harmlessly inside the body including almost invisibly over the surface of the brain, John Rogers.
Interviewee - John Rogers
Our co-programs are in chemistry and material science, to fabricate very tiny structures that have dimensions from microns all the way down to the scale of individual molecules and then to use those approaches to build devices. They offer some range of functional attributes that are unavailable with technologies that exist today
Interviewer - Chris Smith
So, given that biology has over billions of years of evolution already solved a lot of problems or at least given us insight into how we could solve those problems. Is a lot of this just about borrowing from biology, look at how nature does it and say well we could do similar or just still what that does and adjust or adapt it a bit?
Interviewee - John Rogers
Well, yeah, I mean, I think there is a lot of mirror in that type of approach, but the reality is that lot of times we don't understand how biology is doing things. So it's clearly operating at a level of sophistication that far exceeds anything that you can do with manmade technologies, but in many cases you don't have a clear idea of how it's doing it, you can't even begin to mimic it. So, I think for us biologically inspired approach is providing a more practical route to technologies that can be meaningful, you know, on the time scale of, let's say, my own career. So we look to biology for inspiration rather than as an opportunity to do mimicry.
Interviewer - Chris Smith
Do you see biology being informed by what you're doing because obviously I asked the question in one direction, which was is this just a question of robbing from biology but turning it around, does some of what you do in the course of trying to solve the problems you are trying to solve, does that give us insights into some of the biological mechanisms that have previously remained hidden to us?.
Interviewee - John Rogers
Well, our hope is that the answer to that question is yes. A big area of our work is targeted toward classes of devices that can integrate with the human body in ways that have previously been impossible, feature sizes, geometry 3D layouts and heterogeneous collections of materials. If yo
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