Chemistry World podcast - October 2013


Audio Files

The Chemistry World podcast is sponsored by Waters – world leaders in innovative analytical science solutions. Visit waters.com for more information.

1.12 - The online chemistry community has recently been abuzz with talk of fraud, unethical dealings and dodgy data. With great blogging power… comes great responsibility

4.50 - Our taste for spice goes way back into prehistory, research has shown. Traces of the pungent herb garlic mustard (Alliaria petiolata) were recovered from the cooking pots of hunter gatherers living along the shores of the Baltic Sea, around 6000 years ago, but spicy cuisine likely goes back much further, say some experts. Prehistoric humans liked to spice up their lives

Fossils of Archaeopteryx have been known since the 1870s, but debate still rages over its colour © Science Photo Library

7.21 – Can we accurately measure the colour of dinosaurs? Manchester University’s Phil Manning explains how chemists are helping palaeontologists discover the rich palette of pigments in fossils. Colouring in the dinosaur book

14.48 - Outdated assays for monitoring liver health could have caused dozens of drug candidates to be wrongly scrapped during development, according to new research. Call to overhaul liver toxicity testing

18.28 - It’s a kitchen staple for curry enthusiasts, but new research suggests there could be more to coriander than its tangy flavour. A team of US undergraduates have shown the herb has excellent heavy metal binding properties, which they say could help provide people in developing countries with safer drinking water. Spicing up water purification

20.50 - By working with toxicologists while they’re designing new compounds, chemists can avoid problems further down the chain, according to Marty Mulvihill from the UC Berkeley Center for Green Chemistry. Giving screening the green light

27.02 - German researchers have used a combination of bioassay work and high-resolution mass spectrometry to pin down the source of endrocrine-disrupting behaviour in 18 bottled water products. Of 24,520 suspect chemicals, the one that showed consistent results across all tests and displayed anti-androgenic and anti-estrogenic activity is di(2-ethylhexyl) fumarate (DEHF). Worrying molecule found in bottled water

30.02 - A Swedish-led team has become the second to spot element 115, which has a half-life of just 160 milliseconds, and potentially the first to capture its x-ray ‘fingerprints’. Decays and x-rays build case for element 115

33.32 - How did Niels Bohr help us to bin a plum pudding in October 1913?

Full transcript

Interviewer - Chris Smith

This month evidence for 6000-year old hunter-gathered tapas. Well okay, garlic mustard. How a synchrotron has shed new light on what dinosaurs looked like millions of years ago.

Interviewee - Phillip Manning

Pretty pictures of fossils should tell us something straightaway, but they’re imaging with x-rays so there’s something there that’s telling a story. I was invited to join that group and I rapidly realized that what we were seeing were literally the chemical ghosts of life.

Interviewer - Chris Smith

And a new element is born. We’ll find out what it is later in this, the October 2013 edition of the Chemistry World podcast which is sponsored by Waters, who are world leaders in innovative analytical science missions. Visit waters.com to find out more.

(1.12 - with great blogging power… comes great responsibility)

Interviewer - Chris Smith

Hello, I am Chris Smith and also with us in this edition of Chemistry World are Bibiana Campos-Seijo, Ben Valsler and up first, Laura Howes who’s been looking at how to spot a fraud.

 Interviewee - Laura Howes

Okay, there’s a quite lot in this month’s issue of the magazine about data manipulation and the role that bloggers have been playing in actually exposing this data manipulation and looking at the questionable ethics that perhaps some people are using when publishing their science.

Interviewer - Chris Smith

What’s data manipulation? Just define that for us.

Interviewee - Laura Howes

In the most recent examples, there’s been a quite a lot of manipulation of images. So either the images that they’ve reported to show have actually been taken apart and re-jigged a bit. There’s also been cases of NMR data where they’ve shown the spectra and then actually ‘whited-out’ the peaks that they don’t want you to see. There has also been examples of questionable or missing data in what we call the supplementary information, so often people provide a lot more data in extra files to their research papers and there have been some instances where instead of actually all of the data and analyses being there, there are gaps, sometimes there are gaps with notes saying, ‘please put this is in’ and it has to be filled in. Sometimes that says ‘please make up this data’ and what we don’t know is whether that’s please make up this data as in ‘please do the experiment and put it in’ or whether this is please make up this data as in…

Interviewer - Chris Smith

Someone actually wrote that?

Interviewee - Laura Howes

Someone actually wrote that in one of the pieces of supplementary information that has been published online.

Interviewer - Chris Smith

Okay. So there is a question of whether these practices are dubious or whether someone is manipulating a picture for the purposes of clarity, they don’t want to distract you with things you don’t need to worry about because they’re not relevant. So what point do we call this data manipulation, what point do we call it making the reader experience a simplified and easily.

Interviewee - Laura Howes

Sure. I think there’s a point where you might crop an image to make it fit, there might be some interesting things that you could do just to make the image more clear, but I think when for example with the NMR data which they have owned up to this, and they have literally in a graphics program made white squares and put the white squares over the peaks they didn’t want you to see which then showed huge impurities, extra products in the mix to what they were claiming. This then had huge repercussions for anyone who has tried to repeat the experiments, because you’re going to get something very different from what’s reported.

Interviewer - Chris Smith

So what is the bottom-line?

Interviewee - Laura Howes

The bottom-line is that obviously the peer review process, the process where people submit their manuscripts and they’re looked over by the peers is obviously not as rigorous as perhaps we would like to think. And actually it’s bloggers that, maybe they’ve got the time, or maybe it’s just that these things get picked up on the internet now and shared around. So if one person notices it, these things get picked up post publication. The other question is that if we’re seeing these bits what are we missing? Are these the only people or are the other people just better at hiding it? I think we should think more about how we’re looking at images and data during the peer review process. Some of the journals do have acknowledged procedures, some of them look all at the images that are given, some of them at look one in ten and maybe we need to think a bit more about how this is all being done.

(4.50 - Prehistoric humans liked to spice up their lives)

Interviewer - Chris Smith

Thanks Laura. Well food for thought, Bibi, you’ve got something that’s definitely food for thought but historical food for thought.

Interviewee - Bibiana Campos Seijo

Yes, there is some research carried out by a group of scientists in different places around the world. It involves people in the University of York, in Spain as well at the Spanish National Research Council, the Danish Agency for Culture and a couple of other institutes in Germany, where they have actually looked at pottery from more than 6000 years ago and they’ve been able to discover traces of garlic mustard. What these suggest is that people actually were showing an active culinary behaviour, so they were actually adding the mustard to flavour their foods.

Interviewer - Chris Smith

How do they know that? How did they do this?

Interviewee - Bibiana Campos Seijo

They were looking at pottery that had been found around the shores of the Baltic Sea and it was dated around 6000 years ago. They identified a number of lipids there, they did the ratios of carbon-12 to carbon-13 and they were able to distinguish the fish deposits, or marine deposits, from terrestrial deposits. They also found microfossils of mustard seeds there and basically what they discovered is that they were adding the spice to add flavour to the food because we know that it has very little nutritional value.

Interviewer - Chris Smith

No tartare to go with the fish?

Interviewee - Bibiana Campos Seijo

No, at least not that we know of. One of the issues, and I think this study is quite interesting from that point of view, is that if we think about how little spice we add to our food these days in relation to other vegetables, it is a very small amount. And if you think about 6000 years time, being able to find these very small amounts of mustard seed and then identify the mustard is pretty outstanding.

Interviewer - Chris Smith

Was it local mustard? Had that come from a local area or were they moving the stuff around with them?

Interviewee - Bibiana Campos Seijo

The study doesn’t go into that amount of detail. I think, hunter gatherers of that time had a level of sophistication and I think it is quite interesting that they were using it to flavour their foods potentially to take away the flavour of ‘off’ food if you like, we don’t know but they certainly were not adding it for any other purposes, so very sophisticated for prehistoric men.

Interviewer - Chris Smith

So that’s what the canteen had been up to a work.

(7.21 - Colouring in the dinosaur book)

Now on the subject of things that’s really old, what colour were the dinosaurs?

Interviewee - Phillip Manning

My Name is Phil Manning, a reader in palaeobiology at the University of Manchester and I am also the STFC Science and Society Fellow. It started off with the group who had beam some time at Stanford University and they produced some very pretty pictures of some fossils. Now pretty pictures of fossils were imaging with x-rays, so there’s something that’s telling a story. I was invited to join this group and I rapidly realized that what we were seeing were literally the chemical ghosts of life. I started to build a team including inorganic and organic geochemists. So folks who can literally unpick both the living and nonliving parts of the geological record and try to get hold of fossils that might just preserve a little bit more information to help us unpick what was preserved.

Interviewer - Chris Smith

Because there was sort of longstanding dogma that when we look at a fossil we’re merely seeing an imprint and that what was there has long since exited the premises. What you’re saying is that in fact there are things preserved and they may either be directly the chemicals derived from that thing or some kind of onward chemical process which is nonetheless a proxy marker for the chemicals that were there and you can see them.

Interviewee - Phillip Manning

Absolutely, this is where it suddenly starts getting really interesting; the paradigm as you say quite correctly is there are no organic remains left within this echo of life, it has been totally mineralized. There was work done in the last 10 years which started hinting that maybe something has survived. Sorry to use the Jurassic Park one, but I am going to! People started to say they could find DNA or even proteins and whilst they were subsequently proven wrong, that made people sit up and think: ‘actually, hang on, this paradigm that there is total replacement might just shift a little bit’. So what our team decided to do was not look for the elusive DNA, the building block of life. For the simple reason, that’s a sugar cube molecule, it isn’t going to survive. What we started looking for were the literal breakdown products of the building blocks of life and there is certain chemistry in all of us which is very diagnostic to different types of tissue, whether it be muscle, bone or whatever. So we started analyzing the chemistry in living animals and then comparing it to the astoundingly dilute concentrations we can measure using synchrotron light and that’s why no one has done it before.

Interviewer - Chris Smith

I guess that one of the benefits here is that the synchrotron is light which is exciting atoms and making them give out some kind of light you can see, so you can match the presence of those atoms, but it is non-destructive.

Interviewee - Phillip Manning

This is the beautiful thing about this whole synchrotron rapid scan x-ray fluorescence. It’s the actual technique we use. It is totally non-destructive to the sample. As the fossil moves relative to the beam we can raster this intense light across the surface which allows us to reconstruct the very atomic building blocks of the fossils literally line by line to tease out these very dilute concentrations which were so critical to life, of trace metals and other such chemicals.

Interviewer - Chris Smith

And once you have got that data what can you do with it?

Interviewee - Phillip Manning

Well, what we started doing straightaway was comparing what we could see in living animals with what we were seeing in the extinct forms because many molecules, such as the pigment molecule eumelanin, has a very, very distinctive structure. We were able to analyze and identify the architecture of that molecule and we were able to do that absolutely and say ‘this is a eumelanin molecule’ which has survived for 125 million years or in a case of archaeopteryx, 150 million years.

Interviewer - Chris Smith

Astonishing but is it one rarity or is it a comprehensive thing that’s a generalizable phenomenon? Can we find pretty much anything that was in living tissue preserved in this way or there are some things that do chemically preserve very well and other that don’t.

Interviewee - Phillip Manning

Now, that is the big question. Because different environments will preserve organic matter and the trace metal inventory that composes or is part of that organic matter in very different ways. So, if you’re going to be buried in a limestone or a limy mud environment you’ve got much higher preservation potential than you would say in sandstone or a sandy deposit. So we are now beginning to look at a huge variety of depositional environments, so we can better understand the taphonomy, literally burial history or burial laws, what happens when something has been stuffed in the ground.

Interviewer - Chris Smith

How do we reverse the process, to say we know what today’s organisms look like, we know their coloration, we know their phenotype and other characteristics. How do you unwind that and say so this is what my 125 or 150 million year-old dinosaur must have looked like?

Interviewee - Phillip Manning

This is the rub. We can only at the moment image precisely one particular type of pigment. That is eumelanin because the central absorber atom of that molecule which defines that molecule is copper. Now because it’s organically bound we can map its presence across the whole fossil. We can see roughly the distribution of pigments of that particular type of pigment across that fossil and we do 100% of the fossil using this technique. Colour is a very complex thing. It can be down to structure, the actual way in which the surface material absorbs, reflects or refracts light. It can be down to what you eat or drink and likewise there are different types of pigment. We’ve identified one. We have a 1970s black and white TV view of what prehistoric life might have looked like based on the patternation of this dominant melanin pigment which, I should say, is responsible for nearly 70% of coloration in the animal kingdom.

Interviewer - Chris Smith

So, will you be able to close the gap by using other molecules as proxies for the things that don’t preserve so well?

Interviewee - Phillip Manning

We are opening up a pallet of the biochemistry of pigments. And at the moment we have one part of that pallet reconstructed confidently. We now need to reconstruct other major groups of elements associated with specific types of pigmentation in life and as we do so we can slowly build up a much more comprehensive picture of what life used to look like and that has huge value in the 21st Century.

Interviewer - Chris Smith

Phil Manning from Manchester University. You are listening to the Chemistry World podcast, which is sponsored by Waters with me Chris Smith. Still to come, how coriander can help to clean up heavy metal contaminated water and from un-undiscovered to Ununpentium. Scientists say they found element number 115.

(14.48 - Call to overhaul liver toxicity testing)

 But first, are we ditching drugs in clinical trials too readily? Ben.

Interviewee - Benjamin Valsler

So this was one of the stories that they released during the ACS conference in Indianapolis and really the heart of the story is the fact that the current regime of liver toxicity testing that we do when we are investigating a new drug, so during clinical trials, doesn’t seem to be up to scratch.

Interviewer - Chris Smith

What do we do at the moment then?

Interviewee - Benjamin Valsler

We look for a number of biomarkers. In particular, aspartate aminotransferase and alanine aminotransferase. These are two enzymes that are released into the blood stream when liver cells are damaged. So if they are there in the blood, it’s definitely an indication that something bad is happening to the liver. The problem is that doesn’t necessarily mean that this is permanent damage and if we’re just ditching drugs as soon as we see there’re some cells damaged, then we might be ditching drugs that would’ve been really useful and wouldn’t have done the long-term damage. Paul Watkins at the Hamner-University of North Carolina wanted to investigate this a bit more. He pointed out there are two things really that will get a drug thrown out of clinical trial, that is, if it damages your heart or changes the heart rhythm or if it damages the liver and in the last five years or so, we have got better and better at understanding what is really a heart risk, but the liver risk we still are really not very good at.

Interviewer - Chris Smith

Is there an alternative though to using ALT and AST, these two biomarkers.

Interviewee - Benjamin Valsler

There aren’t really many alternatives at the moment and there are teams worldwide who are looking for new ways to do it, new biomarkers. In particular Watkins and his team are looking at genetic analysis, so one of the things is we don’t know how different people will respond, so if we can pin down the genetics of the response and we can say these people are more likely to respond then that thing gives you an idea, if the people who are likely to respond do or do more than the ones are who are unlikely to respond, then that is probably not an indication of long-term damage, is just an indication that they were going to respond anyway.

Interviewer - Chris Smith

Is that what they are advocating? They’re saying let’s get some blood out of people who have had one of these treatments and try to marry genetic expression changes with liver changes, so that we can then pick up a sort of genetic hallmark of liver injury versus benign effects on the liver. Because at the end of the day, you go to the pub and have a beer and you are going to produce some injury to your liver, it doesn’t mean you’re permanently harm your liver. I mean that’s the point you’re making, isn’t it?

Interviewee - Benjamin Valsler

That’s certainly part of what they do, they also look for the range of drugs that there are in very common use both prescription and over-the-counter drugs that we know are safe and they saw exactly the same biomarkers, they saw the same things that would get these drugs chucked off a clinical trial.

Interviewer - Chris Smith

Well Aspirin, it would never get released today, would it? It would never make it through clinical trials as it is far too dangerous.

Interviewee - Benjamin Valsler

Paracetamol of course does all sorts of liver damage and so what they’re really advocating is a broader range of approaches so we can find something that is definitely going to work and if we understand a bit more about the mechanism of action, we are more likely to know when something might be a problem and what we can do to avoid it.

Interviewer - Chris Smith

Do we know roughly how many drugs are getting the boot perhaps unnecessarily owing to us being over cautious like this?

Interviewee - Benjamin Valsler

We pressed Paul Watkins to try and give us a number and he wasn’t willing to actually give a proportion but it is a lot. As I said it’s one of the two most important reasons to ditch a drug so there’re definitely drugs out there that have been ditched for this reason that we almost certainly shouldn’t have done.

Interviewer - Chris Smith

And would have to wait and see where that goes. It sounds like a very important area, though, given the antibiotic pipeline is completely empty at the moment.

(18.28 - Spicing up water purification)

Bibi let’s go back to food, your favourite subject, spicy food.

Interviewee - Bibiana Campos Seijo

Yes.

Interviewer - Chris Smith

One of my favourite herbs, coriander.

Interviewee - Bibiana Campos Seijo

Yeah, I love it as well, so I really like this story and I like it for two reasons, one of course is that I really like coriander and I love curry of course and second is that it is a collaboration between a team of undergraduates at Ivy Tech Community College in Indianapolis which is where the American Chemical Society meeting took place this year. They were working with a group of scientists at the Polytechnic University of Francisco I. Madero in Hidalgo, Mexico. Very interesting story; they went around the university campus collecting samples of biomass and looking at how good they would be in terms of their metal binding ability in water.

Interviewer - Chris Smith

So, good a plant is binding on to heavy metals like zincs, and leads and cadmiums and that kind of thing?

Interviewee - Bibiana Campos Seijo

Absolutely, so obviously coriander is a good example to go for in the first instance and amazing results were observed especially for nickel and lead. For nickel we are talking about removing about 20 mg per gram of nickel in around 45 minutes and for lead it was even quicker than that, in just 15 minutes you were able to remove 145 mg per gram so actually they are very highly selective.

Interviewer - Chris Smith

How were they doing this, would you grind up the plant and just put the pulverized plant in with whatever the toxic source is and then assay after 20 minutes and you show that the amount of the metal has gone right down?

Interviewee - Bibiana Campos Seijo

That’s pretty much it actually. They were using the leaves and the stalks of the coriander plant and they were making it into small tea bags if you like and dropping it in the water and within 15 minutes, hi presto! Lead was gone and 45 minutes, you know the same happened to nickel.

Interviewer - Chris Smith

Do they know what in the plant is doing that?

Interviewee - Bibiana Campos Seijo

They don’t know. The mechanism by which this occurs is very poorly understood, but it is very promising and is very cheap. It is quite reliable and in places where coriander grows wild, it is a very easy way of actually making sure that you can have access to drinking water.

Interviewer - Chris Smith

Oh very well, so long as you like coriander flavoured water. Thank you Bibi.

(20.50 - Giving screening the green light)

Green Chemistry now and a drive to try to make chemical synthesis more toxicology conscious, right from the start, from UC Berkeley, Marty Mulvihill.

Interviewee - Martin Mulvihill

I view the challenge that we face as being one of working together earlier in the design process so that we can use all the great science that we have learned over the past 10, 15 years to actually create new materials and new chemicals that give us all the benefit that we have come to expect from modern chemistry, without some of the unattended consequences that come along with particular petroleum based and persistent chemicals that have made it into society.

Interviewer - Chris Smith

Just outline for us, Marty, some of those problems as they stand at the moment.

Interviewee - Martin Mulvihill

Some of the materials that we make as chemists end up getting into our bodies where they interfere with the natural progression of the biological system, sometimes leading to unintended harm like obesity, cancer or endocrine disruption. Some of these things are not a single cause, it is not just the chemicals, but the chemicals and the environmental chemicals play a part. I think we can do better at designing chemicals that don’t get into the body that don’t persist once they are in the body, and if they are meant to come in contact with our body to make sure that they’re designed so that they don’t cause any harm.

Interviewer - Chris Smith

That must come with a cost though?

Interviewee - Martin Mulvihill

There is a cost but it’s not actually necessarily the cost that people jump to. Sometimes it will take longer to bring these more sustainable solutions to market, but ideally if it’s done well and done in conjunction with our colleagues from other parts of the supply chain, we can actually get out products that still serve their function and don’t necessarily cost a lot more.

Interviewer - Chris Smith

So, it’s sort of injecting this environmental and health awareness into the development process right at the early stage rather than the traditional thing where a chemist comes up with something extraordinary, interesting, extremely useful, but then you have to say ‘is it safe’? And then we discover whether or not it is.

Interviewee - Martin Mulvihill

Exactly! It is all about moving things earlier in the process so that we can test a wider range of potential solutions.

Interviewer - Chris Smith

So why aren’t we doing this already, Marty? If it’s as simple as saying to a chemist ‘do these tests before you take this down the development pathway’, why is no one doing it?

Interviewee - Martin Mulvihill

One thing that has developed over the last 10 or 15 years is better high throughput screening and better computational and mechanistic toxicology techniques. So the new science, the basic science that we’re learning in toxicology is making it easier to apply this knowledge earlier in the design process. But since it is an emerging science it means that the chemists haven’t traditionally been trained to take this into account. So chemists have done a lot over the past 50 years to improve the safety of the chemical industry. We have really moved away from a lot of the worst, most acutely toxic things. One of the things that changes as we get new toxicology tools to understand what’s going on with these chemicals, we need to train the chemists how to use them and how to apply them earlier in the design process.

Interviewer - Chris Smith

Has new technology enabled you to do this better?

Interviewee - Martin Mulvihill

There is a lot of new technology that has enabled this to happen in a more efficient manner. Some of that technology is allowing us to use smaller amounts of chemicals and find them in more complex mixtures. We also have technology that’s allowing us to test more compounds in parallel, higher sensitivity, higher throughput and greater computational power, all of those technologies are advancing this area.

Interviewer - Chris Smith

Have you got any examples of where this is really making a real difference now in chemical synthesis because these are great ideas, they are good goals and they are the direction we absolutely have to go in, no doubt about that. But have you got evidence of how this is really helping yet?

Interviewee - Martin Mulvihill

So, there are lot of folks that would like to turn biomass into fuels. Two classes of compounds, one you have alcohols on one hand. The problem with that is it is a low energy value and it causes some issues with the engine, it can lead to corrosion at high concentrations of ethanol. On the other side, there is a class of molecules called furans. Furans are molecules that are a little bit bigger, they actually burn a little bit better, so you get more power from them, but unfortunately initial toxicology studies of many of the furans have shown that, they are probably not something we want to use in large volumes within our society. They have some potential human health and environmental health concerns. So what we did is took a chemist who has been working on new coupling methodologies, so developing new catalysts for forming oxygen-carbon bonds, so the bond between an oxygen atom on the alcohol and one of the carbon atoms on the furan, and actually created a whole library of potential compounds that take the beneficial characteristics of both of these potential fuels and combine them. And at the same time testing them through high content screening and high-throughput screening to make sure they don’t have any harmful characteristics. So, this is research that’s currently going on right now and could really lead to better bio-based fuels that are more efficient, more cost effective and don’t have the drawbacks in terms of environmental or human health.

(27.02 - orrying molecule found in bottled water)

Interviewer - Chris Smith

Marty Mulvihill and talking of ensuring that things we make are safe, Ben.

Interviewee - Benjamin Valsler

We’ve known for a while that there are products that you get from plastic bottles that may have hormone disrupting or endocrine disrupting behaviours. Some of them we’ve identified and they’re still fairly controversial but we think we have got a handle on a couple of products from plastics that are doing bad things. And now there’s a new study that’s come from Germany - from a couple of different institutes in Germany, Goethe University in Frankfurt and the German Federal Institute of Hydrology - where they’re trying to find other products and they’ve done it in a really unique and interesting way.

Interviewer - Chris Smith

What have they done?

Interviewee - Benjamin Valsler

Well, the key thing is there are two stages. There’s the bioassay, so this is where they’ve taken yeast and they’ve put into that a range of hormone genes and then they grow the yeast up in the water from 18 different bottled water products that they’ve brought in local supermarkets, that’s the same stuff that you’re drinking at home. They look at how well these genes are expressed and how well the products are actually acting.

Interviewer - Chris Smith

The gene is what? Something that responds to the presence of a hormone or a chemical that resembles a hormone and turns on another gene so you could see it. Is that what they’re doing?

Interviewee - Benjamin Valsler

Yes it’s that sort of things. They’re modelling essentially the hormone receptor itself, so if there’s something that is interfering with the receptor for the hormone then it will interfere with these genes and in a very controlled way, they can see from the output how much interaction that was going on. So, that’s the first stage and they’ve done that for each of these different waters. And the second stage is a fairly standard chemical trick, it’s a high resolution mass spectrometry, so they’re looking for every chemical they can possibly find in all 18 of these different waters. They found a total of 24,520 suspect chemicals that they wanted to investigate. This is a fairly early paper, so all they’ve done really is statistically correlate the different compounds with the different effects. That’s given them a few that they think are quite important to look at and importantly one of them was already known to have anti-oestrogenic properties. But the thing is that they’re seeing from the water, both anti-oestrogenic and anti-androgenic properties, so that’s obviously not the only thing in there. They’re looking at something called DEHF that’s di(2-ethylhexyl) fumarate and that’s the one that they know is anti-oestrogenic. They are also looking at other breakdown products of that or isomers of that and they think that they might be doing the anti-androgenic stuff. So they haven’t got an answer to this yet but it is a novel way of actually combining different techniques to try and get a good handle on what it is, beyond the headline bisphenol A and so on, the ones that we’re fairly certain are doing something. There’s a whole raft of other chemicals in there that might be having those effects and it’s through these sorts of techniques that we’re going to be able to find them.

Interviewer - Chris Smith

Slight worry, though.

(30.02 - Decays and x-rays build case for element 115)

Let’s go to something though which we don’t need to worry about so much, element 115, how many atoms of this probably exist in the known universe, Laura?

Interviewee - Laura Howes

Well, not very many here on Earth because they only have a half-life of 160 milliseconds.

Interviewer - Chris Smith

As long as that, gosh!

Interviewee - Laura Howes

So, yes it’s a long lived element! This is news from a Swedish team that were working at Darmstadt in Germany which is one of these places that does a lot of heavy element research and this is more evidence for element 115 or ununpentium as you might see it referred to on your periodic table.

Interviewer - Chris Smith

So, how are they making these elements?

Interviewee - Laura Howes

Lot of these heavier elements that are made in these large colliders are done by basically smashing other elements together and trying to get them to fuse into a very heavy nucleus . In this case they were using calcium ions and americium. And those are the two elements and smashing the calcium ions into the americium then looking to see what results. You can’t, if these elements are so short-lived, you can’t necessarily take it away and look at it and play around with it. What you end up doing is actually looking at how it breaks down and then going back and working backwards to see if you got the element that you were looking for.

Interviewer - Chris Smith

So, maybe a daft question, but if this thing hangs around for milliseconds, why is it useful? Why are we bothering to look for this stuff?

Interviewee - Laura Howes

Well, I think one of the things that we should really stress is that actually the periodic table we think of is being static understood thing but it’s still in slight flux. We’re still understanding everything that goes on in it, we’re still trying to understand what are the elements within it and how those patterns work. If you think about Mendeleev when he started the periodic table we know that there were gaps in the periodic table but by putting it together he could predict certain properties. So, one of the interesting things about trying to make these heavier elements is we’re trying to predict the properties of these and see whether they match and whether predictions meet with reality. One of the other important things is that through this prediction there is what we term the island of stability and a couple of elements on there should be a really nice, stable, heavy, heavy element. So, this is work on the way to seeing whether this island actually exists as we predict it or whether it falls apart. If it falls apart then that’s really interesting, because it really throws up all sorts of questions.

Interviewer - Chris Smith

So, would you have to make some ununpentium, 115, and then wham something into that within milliseconds to make something bigger to give it the big one? Or do you just wham two slightly bigger things together to go directly to the big one?

Interviewee - Laura Howes

So, you would probably have to wham slightly bigger things, as you put it. What you have to remember is, to make element 115, you don’t actually just take something that adds up to 115 and smashing it together. You’re smashing together things that are actually heavier than that [on aggregate] and then some helium will bounce off and some protons will bounce off and you will get this core. That’s interesting in and of itself: what you have to get to bash together to get this element. Then you can work out if we want to make a heavier element what do we going to have to bash together to make those heavier elements. So it’s all about trying to piece together how we get to the next stage. It’s very theoretical at this point but it’s very exciting to think about what you can make if you would get that.

(33.32 - How did Niels Bohr help us to bin a plum pudding in October 1913?)

Interviewer - Chris Smith

And let’s stay with the structure of atoms because big centenary Ben, in the trivia this month.

Interviewee - Benjamin Valsler

It is, it is yes. So a hundred years ago this month Niels Bohr, the very famous physicist was in the middle of a really productive period of his life. So we wanted to ask you why is it that you think researchers might have put a plum pudding in the bin with Niels Bohr’s work?

Interviewer - Chris Smith

Well, this is what we were taught at school and we were learning about Rutherford and his famous experiment firing alpha particles into thin gold leaf and seeing them miraculously bouncing back because people had thought that the structure of an atom was this sea of negativity with the odd blobs of positive in it which were the plums in the plum pudding and there’s no way such a model would be reconcilable with turning alpha particles back on themselves. You need something very tiny and intensely charged to do that, so he threw that out and said there must be a tiny but massive nucleus with the electrons around the outside.

Interviewee - Benjamin Valsler

That’s right and that was Rutherford’s work in 1911, but actually if you look at the descriptions of his model, his works are that the positive charges must now be coalesced into the middle into this nucleus and then the negative charges are all around that in a sort of cloud. But actually, it still does bear some plum pudding hallmarks. It still looks like a solid spherical thing that could well have things at any point in it. And it’s Bohr’s work who was working with Rutherford a couple of years later that really put the nail in the coffin of the plum pudding. It was Bohr who worked out that the electrons orbit at given distances from the nucleus and that they can only exist in certain energy levels and this was pulling together really interesting ideas that were happening at that time by Planck and Einstein as well.

Interviewer - Chris Smith

The photoelectric effect, which he got the Nobel Prize for subsequently, was looking at that very concept of the electron quanta, wasn’t it?

Interviewee - Benjamin Valsler

Exactly, and it was looking at the emission lines of hydrogen that gave Bohr this idea. This was the first time we described the atom in what we can now call a quantum mechanical way. And we know that it’s not exactly right and that the modern valence explanation is more accurate, but this now 100-year-old description is still what we use to describe the structure of the atom to children in school and it’s really the very first thing you learn about quantum mechanics.

Interviewer - Chris Smith

Thank you Ben and there we must leave it for this month. Thank you to the rest of the Chemistry World Team, Laura Howes and Bibiana Campos-Seijo and our guests Phil Manning and Marty Mulvihill. The Chemistry World podcast is sponsored by Waters who are world leaders in innovative analytical science solutions. This programme is put together by Meera Senthilingam and I am Chris Smith. We are from thenakedscientists.com Thank you very much for listening and until next time, Goodbye.

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