Scientific American - Chemistry

Researchers Gain New Insights into the Mystery of Thalidomide-Caused Birth Defects

Thu, 11 Mar 2010 14:00:00 EST

Half a century ago, thousands of pregnant women in 46 countries took a drug for morning sickness that would later be discovered to cause severe malformations in developing fetuses. Worldwide, roughly 10,000 affected children nicknamed "thalidomide babies" were born with multiple defects, including the characteristic shortened upper limbs (a condition known as phocomelia, Greek for "seal limbs"), before the drug was discontinued in 1961 after four years on the market.

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Divining the Right Drug

Thu, 11 Mar 2010 09:00:00 EST

Imagine suffering from the crushing weight of major depression, then finally getting diagnosed and starting treatment with a drug--only to realize after two months that the medication, despite its unpleasant side effects, is not alleviating your depression. Unfortunately, this experience is far from rare: more than two thirds of patients with depression have no luck with the first medication they are prescribed and must also endure the withdrawal effects that come with discontinuing a drug before trying a new one. Finding the right treatment can prove a lengthy, painful process of trial and error. A new technology, however, may bypass this ordeal by gauging very early in a treatment regimen how well a drug is working based on the patient’s brain waves.

The technology, called quantitative electroencephalography (QEEG), measures a person’s brain-wave pattern with EEG and then compares it with a database of normal samples to detect abnormal function. In a study published in the September 2009 issue of the journal Psychiatry Research , scientists used QEEG to record brain activity in subjects with major depressive disorder before they began treatment, after one week on an antidepressant and after eight weeks on the drug--the period it takes such drugs to achieve full effect. Changes in the QEEG readout after just one week of medication predicted 74 percent of the time whether patients would experience either a recovery or a remission of symptoms by the end of eight weeks.

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TB or Not TB?: Novel Detector Could Shorten Testing Times, Aid Treatment Efforts

Wed, 10 Mar 2010 15:30:00 EST

Tuberculosis is a serious public health challenge in the developing world, where the infection claims roughly two million lives each year, according to the World Health Organization (WHO) . Yet the disease, which is a leading killer of patients with HIV/AIDS, is cumbersome to detect, resulting in delayed or inappropriate treatment, greater spread of the infection and preventable deaths. [More]

Sunshine is free, so can photovoltaics be cheap?

Wed, 10 Mar 2010 12:35:00 EST

Here's how to make a solar cell from silicon : take one solid block of doped silicon, saw it into thin wafers, layer said semiconductors beneath a panel of transparent glass, connect them to a metal electrode that can channel away the electrons knocked loose by incoming photons and turn it into a photovoltaic device. That process has at least two flaws: such silicon is expensive, contributing more than half to the final price of a solar photovoltaic, and sawing it turns as much as half of that silicon into wasted grit.* [More]

PET project: Using organic catalysts to make more biodegradable plastics

Tue, 09 Mar 2010 17:30:00 EST

Whereas most discarded plastic water and beverage bottles (those imprinted with a number 1 within a triangular arrow) can be recycled , the resulting second-generation plastic is generally unusable for making new plastic bottles. This is because the polyethylene terephthalate (PET) thermoplastic polymer used to make the original bottles is often made with the help of metal oxide or metal hydroxide catalysts that linger in the recycled material and weaken it over time. [More]

Storing megawatts: Liquid-metal batteries and electricity

Tue, 09 Mar 2010 16:31:00 EST

Making aluminum requires a lot of electricity. That's because the metal bonds tightly to oxygen and it takes a lot of energy to break that bond. In essence, the process of making aluminum is a giant battery with the silvery metal being reduced to purity at the cathode while oxygen bonds with the carbon anode to make, you guessed it, CO2. It takes roughly 15 kilowatt-hours of electricity to make just one kilogram of aluminum via electrolysis. [More]

Smokestash Industry: ARPA-E Seeks Breakthroughs in Carbon Capture Technology

Tue, 09 Mar 2010 15:01:00 EST

WASHINGTON--Every second, our bodies capture carbon dioxide in our tissues, transport it via the blood, and dump it in the lungs from where it is exhaled. This unconscious process is yet another way humans contribute to the accumulation of the greenhouse gas in the atmosphere--albeit in a minuscule volume compared with burning fossil fuels . The key to this metabolic process is an enzyme called carbonic anhydrase and it's efficiency at capturing and releasing CO2 is what human engineers want to mimic at the power plant scale. [More]

Trichodesmium : The world's most famous nitrogen fixer

Tue, 09 Mar 2010 11:42:00 EST

Editor's Note: Journalist and crew member Kathryn Eident and scientist Jeremy Jacquot are traveling on board the RV Atlantis on a monthlong voyage to sample and study nitrogen fixation in the eastern tropical Pacific Ocean, among other research projects. This is the sixth blog post detailing this ongoing voyage of discovery for ScientificAmerican.com .

Imagine you’re in space, floating high above the Earth. Picture the world’s oceans, glimmering sapphire under the heat of the sun and the protection of the ozone layer. Look closer, there’s a patch of brown in the middle of all that blue. It’s a bloom of phytoplankton called Trichodesmium , a “world famous” nitrogen fixer. [More]

Seeing the Little Picture: Novel Nanocoating Gives Atomic Force Microscope Users a Better Look at Individual Molecules

Mon, 08 Mar 2010 15:20:00 EST

Spotting a disease in its earliest stages can help to facilitate its treatment greatly, yet telltale clues are often hidden at a scale too small to study accurately. This hindrance has some researchers looking for ways to use high-powered atomic force microscopes (AFMs) to study individual molecules for disease markers [More]

Another reason vitamin D is important: It gets T cells going

Sun, 07 Mar 2010 13:01:00 EST

Vitamin D deficiency has been linked to a rapidly expanding inventory of ailments--including heart disease , cancer and the common cold . A new discovery demonstrates how the vitamin plays a major role in keeping the body healthy in the first place, by allowing the immune system's T cells to start doing their jobs. [More]

Genetics in the Gut: Intestinal Microbes Could Drive Obesity and Other Health Issues

Fri, 05 Mar 2010 19:00:00 EST

Outnumbering our human cells by about 10 to one, the many minuscule microbes that live in and on our bodies are a big part of crucial everyday functions. The lion's share live in the intestinal tract, where they help fend off bad bacteria and aid in digesting our dinners. But as scientists use genetics to uncover what microbes are actually present and what they're doing in there, they are discovering that the bugs play an even larger role in human health than previously suspected--and perhaps at times exerting more influence than human genes themselves. [More]

Can solid-oxide fuel cells like the Bloom box remake the energy landscape?

Fri, 05 Mar 2010 16:34:00 EST

The fuel cell has a long history. Various types of fuel cells have been part of the NASA space program, and the basic science of how fuel cells work--an energy carrier comes in, creates a flow of charge in the anode, which migrates to the cathode creating a current, and separated by some form of electrolyte--has been known for more than a century. Yet, Bloom Energy believes the time is finally right for one of the more promising fuel-cell technologies--solid-oxide fuel cells, so-called because the electrolyte is a solid rather than the more common liquids--to produce electricity on a grander scale. [More]

A Theory Set in Stone: An Asteroid Killed the Dinosaurs, After All

Thu, 04 Mar 2010 17:30:00 EST

Although any T. Rex –enthralled kid will tell you that a gigantic asteroid wiped the dinosaurs off the planet, scientists have always regarded this impact theory as a hypothesis subject to revision based on further evidence gathered from around the globe. Other possible causes, such as volcanism and smaller, multiple asteroid strikes, never actually went away, and over the years researchers raised important points that did not fully jibe with a history-changing celestial impact near the Yucatan peninsula one awful day some 65.5 million years ago. [More]

Impact Factor: Can a Scientific Retraction Change Public Opinion?

Thu, 04 Mar 2010 11:45:00 EST

When science revises its stance, the field itself follows established protocol to adapt, but public opinion can be slow to catch up. Rather than wiping the slate clean, last month's retraction of a key paper proposing a link between childhood vaccines and autism seem only to have widened the societal divide on the issue. And the rising rate of retractions--roughly ninefold between 1990 and 2008--suggest that there could be more cases in which public opinion carries on long after science has reversed course. [More]

Shift happens: Will artificial photosynthesis power the world?

Wed, 03 Mar 2010 17:31:00 EST

One drinking- water bottle could provide enough energy for an entire household in the developing world if Dan Nocera has his way. A chemist from M.I.T. and founder of the company Sun Catalytix, Nocera has developed a cobalt-based catalyst that allows him to store energy the same way plants do: by splitting water. [More]

Not Just for Fuel Anymore: Hydrocarbons Can Superconduct, Too

Wed, 03 Mar 2010 15:48:00 EST

Superconductivity is one of those nearly magical properties that seem to defy all intuition for how the physical world ought to work. In a superconductor, electric currents flow without resistance --an electron passes unimpeded through the material like a torpedo through some frictionless ocean. After discovering the phenomenon in 1911 Dutch physicist Heike Kamerlingh Onnes showed that an electric current in a closed superconducting loop of mercury would keep flowing long after the driving potential was removed; he demonstrated his discovery by carrying such a persistent current from the Netherlands to England. [More]

Next-Gen Scientists Honored for Evolving Medicine and Renewables [Slide Show]

Wed, 03 Mar 2010 15:00:00 EST

The more mysteries that scientists unlock, the more opportunities emerge for the next generation of researchers to transform newfound knowledge into tomorrow's breakthroughs that serve society. The Lemelson–M.I.T. Program recognized several potential breakthroughs Wednesday in awarding four of its $30,000 Lemelson–M.I.T. Student Prizes to those from California Institute of Technology (Caltech), the Massachusetts Institute of Technology (M.I.T.), Rensselaer Polytechnic Institute (R.P.I.), and the University of Illinois at Urbana–Champaign (U.I.U.C.). [More]

Toxic Gas, Lifesaver (preview)

Wed, 03 Mar 2010 08:00:00 EST

Imagine walking into a hospital emergency room, with its hand-sanitizer-adorned walls and every surface meticulously scrubbed free of contaminants, only to encounter the stench of rotten eggs. Distasteful though this juxtaposition might sound, the toxic gas synonymous with that smell--hydrogen sulfide (H 2 S)--may well become a fixture in such settings in the future. Over the past decade scientists have discovered that H 2 S is actually essential to a number of processes in the body, including controlling blood pressure and regulating metabolism. Our findings indicate that if harnessed properly, the gas could, among other benefits, help treat heart attack patients and keep trauma victims alive until they can undergo surgery or receive a blood transfusion.

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A Common Herbicide Turns Some Male Frogs into Females

Tue, 02 Mar 2010 19:31:00 EST

The bountiful fields of the U.S. are awash in atrazine . Some 36 million kilograms of the odorless, white powder are applied on farms to control grassy weeds. Some 225,000 kilograms of the herbicide fall with the rain each year, sometimes up to 1,000 kilometers from the source. All that atrazine may be having another effect: turning male frogs female. [More]

Accentuating the Negative

Tue, 02 Mar 2010 09:00:00 EST

Consider the following statements: “War continues.” “No sign of peace.” Does our brain treat these two sentences differently, despite their identical meaning? A new study suggests it does. [More]