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A.
The Dangers of Certain Dietary Supplements
Narrator:
This is Science Today. Consumers should be wary of
dietary supplements marketed for weight loss or enhancing
athletic performance. Toxicologist Christine Haller
of the University of California, San Francisco, says
these products often contain a variety of stimulants
which may cause several adverse reactions.
Haller:
The products we're real worried about contains ma
huang, which is an herbal form of ephedrine and caffeine
in combination. And these two products in combination
seem to be potentially more dangerous. What people
may experience is a sense of nervousness or jitteryness,
nausea and vomiting. But it could be more serious
- chest pain indicate a possibility of having a heart
attack or stroke.
Narrator:
Because these are herbal products, they're not regulated
by the FDA, so it's up to the consumer to adopt a
"buyer beware" attitude.
Haller:
These products in general are called thermogenic,
but that's just a phrase to look for when you're looking
at a label. If they claim it's a thermogenic product,
then you really should turn it over and look at the
ingredients and by very careful about taking it.
Narrator:
For Science Today, I'm Larissa Branin.
B.
A New Laser Helps Produce Stronger Hip Implants
Narrator:
This is Science Today. A new, high powered glass laser
may have a great impact in the medical field. Lloyd
Hackel, a laser physicist at the Lawrence Livermore
National Laboratory says metals treated, or peened,
with this laser are up to five times stronger than
those compressed using metal balls. One of the medical
components which may greatly benefit from laser peening
are the titanium joints used in hip implants.
Hackel:
Those go under a lot of cycles of flexing and you
just don't want them to fatigue and wear out because
it means a person has to undergo another very expensive
operation. If we can peen these parts and get them
to last three to five times longer, that's an enormous
benefit to the person with the hip implant.
Narrator:
The Lab's glass laser is much faster than lasers developed
in the past.
Hackel:
This laser can shoot like ten times a second and so
we can process potentially in the peening, up to a
meter square of area per hour and that's 20 to 50
times faster than any laser of this type that you
could go buy.
Narrator:
For Science Today, I'm Larissa Branin.
C.
New Technology Creates Corrosion-Free Materials
Narrator:
This is Science Today. Researchers at the Lawrence
Livermore National Laboratory have created thousands
of layers of fabricated materials, each about a millimeter
thick, known as mutlilayers. Troy Barbee, a material
scientist, says multilayer technology may greatly
reduce the expensive cost of preventing and repairing
corrosive materials.
Barbee:
Corrosion costs this country some phenomenal amount
of money every year in terms of the degradation of
things and failure and the need to do preventive maintenance.
Narrator:
A good example of how multilayers may potentially
reduce cost would be by replacing the silver components
in the Keck Telescope with a more stable material.
Barbee:
Silver is notoriously unstable and in fact, if you've
ever tried to eat eggs with silverware, you've noticed
that it gets black in a hurry. Therefore, let's assume
we develop this very stable coating which will not
corrode and has high performance. One would put that
on the Keck mirrors and that would the only coating
you ever put on it. Which is very exciting.
Narrator:
For Science Today, I'm Larissa Branin.
D.
How To Choose The Right Pacemaker
Narrator:
This is Science Today. There are two types of pacemakers
- dual and single chamber. While the dual chamber
model mimics the heart's natural function more closely,
researchers have found there's really not a big difference
in terms of how well patients do with either pacemaker.
Dr. Lee Goldman of the University of California, San
Francisco led the study.
Goldman:
We measured quality of life from a whole variety of
directions. Such things as functional status...what
can someone do? Emotional and psychologic well-being.
How happy are you with the things that you can do?
The differences between two kinds of pacemakers were
trivial compared with those differences.
Narrator:
The dual chamber pacemakers are used more in the United
States and in younger patients.
Goldman:
It looks as though to us, that most of those are simply
preconceived notions among doctors as to who might
benefit most from these different kinds of pacemakers.
Patients should talk with their doctors about what
kind they're putting in. Not just assume that all
pacemakers are the same.
Narrator:
For Science Today, I'm Larissa Branin.
E.
An Efficient Way To Clean Up Toxic Sites
Narrator:
This is Science Today. Chemists at the Lawrence Livermore
National Laboratory have proven that removing underground
contaminants by heating and steam-cleaning the soil,
is more efficient than the conventional pump and treat
systems. Chemist Roger Aines and his colleagues had
phenomenal results at a Superfund site in California.
Aines:
It's an old pole treating yard in which they dipped
telephone poles in creosote and the creosote got into
the ground water. In twenty years of this pump and
treat, they've been averaging about ten pounds of
creosote a week removed.
Narrator:
The steam method removed six hundred thousand pounds
of creosote in less than a year - that's several thousand
times more than before.
Aines:
They estimated that it was going to take 120 years
to clean that site. Now using steam, they estimate
they'll be done in less than five years and that includes
a lot of just watching it after you're done to make
sure that you really did finish.
Narrator:
Aines says the steam method is just starting to take
hold and already has great public acceptance.
Aines:
It just makes sense. People go 'oh yeah, I'd heat
it up if I wanted to get it clean faster, too!"
Narrator:
For Science Today, I'm Larissa Branin.
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