Published online 29 August 2005 | Nature | doi:10.1038/news050822-9


American Chemical Society

Andreas von Bubnoff writes from Washington DC, where thousands of chemists have converged to discuss everything from drug discovery to detergents.

<blogentry><entrydate month='09' time='18:00' daynum='05' day='01' year='2005'/> Day 5: Oh deer

Chemistry: the stuff of lifeChemistry: the stuff of life© Photodisk

Many people were already gone on this fifth and last ACS meeting day - including the speakers. At least one didn't bother to show up for their own talk, while another gave theirs through a pre-recorded PowerPoint presentation.

This may seem a bit like cheating, but the talk was still one of the more interesting ones I heard today, tackling the long-running debate about monitoring sports doping. Many people say it is impossible to monitor athletes for all the drugs they might take to enhance their performance. And, it seems, even the substances we know about are hard to measure. Apparently there is a 25% error rate in many such tests, making it very difficult to call whether someone is guilty or innocent. The pre-recorded speaker gave one example of a European soccer player who was wrongfully convicted in the past.

On a lighter note, someone else who stuck around for the final day had some gardening tips for his audience. Are deer eating your plants? Spray them with baby food, suggests Bruce Kimball.

Kimball, of the National Wildlife Research Center in Fort Collins, Colorado, points out that many baby foods contain chopped up milk proteins called hydrolyzed casein. This is meant to make it easier for babies to digest, but it is an acquired taste. Babies not exposed to casein in the first few months of life seem to turn their noses up at it later. As do deer. I'm not sure how anyone might have discovered this, but there you are - a cheap and environmentally friendly way to keep deer out of your vegetable patch.

</blogentry><blogentry><entrydate month='09' time='19:00' daynum='05' day='01' year='2005'/> Day 5: When breasts go platinum

In the long-running saga of problems with silicone breast implants, S.V.M. Maharaj of the American University in Washington DC presented further data that they can leak platinum - a metal that has been associated with health problems such as connective tissue disease, autoimmune disorders and neurological problems

Maharaj says she has found higher platinum concentrations in urine samples of women with silicone breast implants than in women without; and more platinum in children conceived after their mother had received the implants too. She suggests women who want children ought to take this into consideration when thinking about getting implants. A moratorium was placed on silicone implants in 1992, though women can still get them.

Two people in the audience plainly didn't think there was that much cause for worry. One said that since an implant typically contains 2 milligrams of platinum, and the research shows some 22 micrograms of the metal per liter of urine, a woman with silicone implants should pee out all the platinum in just a few months. Since platinum levels instead appear to stay high, the metal must come from another source. He told me later that he thinks much of the platinum comes from platinum catalysts in cars. Maharaj counters that implants probably contain much more platinum than 2 milligrams.

The other objector mentioned that other studies that don't see any difference in platinum concentrations between women with and without breast implants. Maharaj admitted that her study looked at only a few subjects (in many cases under ten), and that it needs to be expanded, but she defended her findings.

It was interesting to see that the two people in the audience who had criticized her results both work for the silicone industry. One seemed to have prepared the questions he was going to ask before coming to the talk.

</blogentry><blogentry><entrydate month='09' time='20:00' daynum='05' day='01' year='2005'/> Day 5: No jobs; only money

I told ACS president William Carroll two things I had heard from conference participants: there are "no chemistry jobs", and fewer domestic students applying for grad school now than just a few years ago. But whether these two complaints are compatible with each other is up for debate. One recruiter told me that the reason many students are leaving school is to get into industry with a salary of some $60,000 a year.

"This reminds me of the restaurant where the food is no good and the portions are too small," laughs Carroll. Of course there are jobs, he says: so much so that some sectors, such as the defense industry, can't find enough people to fill them. He adds that the job situation can only get better, since the average age in the work force today is 41 years; about a third of these people are due to retire in the next ten years. Good news for the many young participants at this conference.

</blogentry><blogentry><entrydate month='08' time='17:00' daynum='04' day='31' year='2005'/> Day 4: Something in the water

Here's a saddening thought: with all the news about the negative side-effects of antidepressants flooding the media, the antidepressants themselves seem to be flooding waterways.

One poster here took a close look at just how much of these drugs is making it out of wastewater plants and into the environment. In a survey of lakes and streams, they found traces of Prozac, Zoloft and Paxil, along with some SSNRIs (Selective Serotonin and Norepinephrine Reuptake Inhibitors) such as Effexor and Wellbutrin. The fact that all of these compounds are sometimes found together is troubling, says Melissa Schultz of the USGS, because they might act in combination.

SSNRI's are sometimes prescribed instead of SSRIs, a common antidepressant that has had recent press for the side effect of apparently causing some suicides. Schultz says she has found values of around 10 ppt (parts per trillion) of these compounds in waterways.

Is that enough to cause problems? No one really knows. But Kevin Armbrust, from the Mississippi State Chemical Laboratory, says he too has found similar results. And, he adds, another recent study showed that these levels can cause behavioral changes in mosquito fish. Knock at the glass of an aquarium housing a dosed-up fish and it doesn't swim away, but instead reacts very slowly. "They just look at you when you tap on the glass," Armbrust told me.

And we know that these drugs definitely affect animals when in higher doses. Schultz showed me the picture of a cat named Kaffee who is on 'kitty Prozac'. Poor thing.

</blogentry><blogentry><entrydate month='08' time='22:00' daynum='04' day='31' year='2005'/> Day 4: Sugar and fat

Two talks today described progress in developing real time measurement of glucose levels for diabetics.

Most diabetics rely on pinpricks to measure their blood sugar levels. So finding a non-invasive method is on the minds of many inventors. Some companies have started to work on wrist-watch-type devices that use lasers or ultrasound to measure glucose without drawing blood. Nadine Barrie Smith of Pennsylvania State University presented something similar at this conference.

Her team uses ultrasound to make small, temporary holes in the skin. The fluid that comes to the skin's surface can then be tested for its glucose content. Smith says she has tested the method in rats, rabbits and pigs, all with good results. The measurements in pigs are particularly important, she adds, because it shows that it can work even when a heavy layer of fat lies beneath the skin. Many diabetics are overweight, she points out.

Meanwhile, Amos Mugweru, also of Pennsylvania State University, is working on an implantable device to measure glucose levels. It's a chip about 1.3 cm across, which he hopes to soon test in animals - perhaps just a few weeks from now - and eventually in humans. The chips are embedded in a biocompatible gel that stops the body from rejecting them. And the gel contains enzymes that oxidize glucose, creating a change in chemical charges that can in turn be picked up as a current. Such a device, he points out, could be useful for diabetics or anyone who may need to have their health monitored from afar.

</blogentry><blogentry><entrydate month='08' time='14:00' daynum='03' day='30' year='2005'/> Day 3: Honest, it's funny...

It has come to my attention that chemists like to tell jokes. This holds even though the jokes aren't always understandable, and, as some chemists who wanted to remain anonymous told me, they also aren't always funny. (This perhaps puts them in good company with mathematicians and physicists - see ""Don't drink and derive": ").

Here's a simple one: "Chemists have solutions." Okay, if you think that's funny, maybe that means you should become a chemist.

And here is a joke that the ACS president, William Carroll, told me: "Two hydrogen atoms leave a restaurant. One says, 'I forgot my electron!'. Replies the other, 'Are you positive?'." This joke seems to be rather well known, according to an informal survey I took in the Washington Convention Center yesterday. So it seems quite appropriate for the representative of American chemists to tell me this one.

Chemists also sometimes make dirty jokes. Someone working at the booth of the American Chemical Society told me these two: "Chemists do it on the table periodically." And, "chemists can make your Bunsen burn." Oh well.

There are also humorous comments about chemists working in certain fields of chemistry. The presenter of a recent talk about about antioxidants in coffee advised the audience to not have dinner with an analytical chemist, because they might want to test the wine instead of tasting it.

And for the finale, a postdoc, himself an inorganic chemist, told me this joke about physical chemists (forgive me if I don't get every detail right here): three scientists go to a horse race track. They challenge each other to predict which horse will win. The mathematician, not unexpectedly, calculates the odds. The physician tries to fix the event by feeding a horse some drugs so it will win. And the physical chemist? He starts out by saying: "Let's assume a spherical horse."

Okay, you really might not get that. You see, people who reduce everything to equations, as physical chemists do, have to make a lot of assumptions, some of which are quite ridiculous. So you get atoms that are infinitely small dots and, well, horses that are perfectly spherical, for example. Oh, never mind. Maybe you had to be there.

</blogentry><blogentry><entrydate month='08' time='18:00' daynum='03' day='30' year='2005'/> Day 3: cheap tricks

It seems that chemists, when not exchanging jokes, spend a lot of their time thinking about food. Not a bad idea, seeing that it is fodder for plenty of interesting chemistry. Today we heard the science of how the taste of what you eat or drink changes the perception of what you are going to eat next. The demonstration of this was impressive: if you have an apple, which is sweet, wine (or anything else) you have after that will taste stronger. If you have a lemon, which is sour, wine will taste milder. And if you have salt, wine will be a lot less bitter.

The bottom line: if you are going to offer cheap wine to your guests, offer it with something salty. Tricky.

</blogentry><blogentry><entrydate month='08' time='18:00' daynum='03' day='30' year='2005'/> Day 3: I can see your socks

I also got to see pictures of 'sock lines' today. Yes, you read that correctly. That's what you get when you measure the microwaves that have been reflected off people. David Sheen of the Pacific Northwest National Laboratory in Washington has been developing a microwave radar device to help detect explosives or concealed weapons at airports and in other high security areas. (You can read about similar high-tech systems in 'Bullets found in airport arrest' )

The system would help to lower peoples' exposure to X-rays, which can be damaging in high doses. But Sheen said the Transportation Security Administration and others have now stopped funding the work, in part because of privacy concerns: the method enables you to see through clothing. Well, wasn't that the point?

</blogentry><blogentry><entrydate month='08' time='17:00' daynum='01' day='29' year='2005'/> Day 2: Food, glorious food

The coffee keeps flowing on Monday, day two of the ACS meeting. But today I also tracked down free chocolate, cookies and peanut butter. They were available in the back of room 209A of the Washington Convention Center, where George Inglett of the National Center for Agricultural Utilization Research in Peoria, Illinois, gave a talk on a new food additive called C-trim. Basically, C-trim is a concentrate of oat fibers. The fibers make you feel full but can't be digested, which makes you eat less. They also lower cholesterol and glucose levels in the blood, Inglett claims.

C-trim contains about 30 percent or more of the soluble fiber called beta-glucan - ten times as much as oatmeal. You can mix it with water and add it to all kinds of different foods like yoghurt, smoothies and baked goods without changing their texture or taste, Inglett says. Seems true as far as I can tell - the cookies tasted pretty good. But I'll probably always prefer ones made with good old-fashioned butter and flour.

</blogentry><blogentry><entrydate month='08' time='22:00' daynum='01' day='28' year='2005'/> Day 1: The chemistry of java

It's late summer in Washington DC, and warm and humid as usual here outside the Washington Convention Center, where an estimated 12,000 scientists are gathering at the 230th national meeting of the American Chemical Society. But it's easy to forget the humidity after spending the day inside this huge air-conditioned building -- which reminds me very much of an airport, except that everyone here has a badge hanging around their necks.

One perk I’ve discovered to the meeting is that there is lots of free coffee. What's more, there are actually chemists who study coffee. Quite appropriately, one of them, Joe Vinson of the University of Scranton in Pennsylvania, gave his talk at 8:30 a.m. on a Sunday, perhaps to make sure that everyone in the audience had some coffee before entering the room. In his talk, Vinson reported that coffee is the number one source of antioxidants in the US: The average American consumes 1299 milligrams of antioxidants per day in coffee, but only 294 milligrams per day in tea. And no, that's not because coffee beans contain so many antioxidants. It’s simply because we drink so much of it. An average person in the US drinks 252 milliliters of coffee per day, much more than black tea (79 milliliters/day), which is why tea comes in second.

Dark chocolate and wine also contain a respectable amount of antioxidants. Vinson clearly likes these results, because they mean he can keep eating and drinking what he likes: "I call it a good day to have tea in the morning, chocolate as a snack, and red wine in the evening," he says.

Caffeine is clearly part of the reason why we drink so much coffee. The other reason may be its aroma, and that's what Jianming Lin studies. Lin, based at the company Firmenich in Princeton, New Jersey, found that about 50 of the estimated 800 volatile compounds in coffee oil were strong enough to be responsible for its aroma. Surprisingly, most of them don't smell like coffee. Instead, some smell burnt, while others smell sweet, fatty or cheesy. Maybe, if we’re ambitious, one day we can use them to synthesize coffee from scratch.

Tonight’s poster session featured an entirely different take on coffee – it found that caffeine is one of the best substances to be used as a tracer for wastewater from human sources. That's because caffeine gets degraded by sunlight so slowly that it’s present for at least ten days in the waste, says Jen Shi of Florida International University. The other reason has to do with the fact that so many people drink coffee and other caffeinated drinks. "Caffeine," Shi says, "is everywhere."

</blogentry><!--<blogentry><entrydate year="2005" month="08" day="28" daynum="01" time="16:00"/><illusr rid="i1"/>Check back here on Monday 29 August to find out what happened on Sunday.

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