Chemical & Engineering News picks photo contest winner

WASHINGTON - Chemical & Engineering News (C&EN) today announced the winners of its inaugural photo contest. C&EN is the weekly newsmagazine of the American Chemical Society (ACS), the world's largest scientific society.

First place went to Drexel University materials science graduate student Jennifer S. Atchison. She made the silicon nanocones shown (right) in a dazzling, scanning electron microscope image. The cones, barely 1/50,000th the width of a human hair, formed through the decomposition of silane, a silicon-like compound, at a high temperature in a chemical vapor deposition apparatus. It produced the kind of thin films often used by the semiconductor industry.

The second place winner, Robert L. D'Ordine, Ph.D., a biochemist in Ballwin, Mo., submitted a picture of a magnetic stirrer, a beaker of water, and colored paper used to capture a whirring mass of water (water vortex), a familiar laboratory phenomenon. Third place winner Ryan O'Donnell, now a graduate student at Johns Hopkins University, submitted a colorful light microscopy image of ammonium nitrate crystals.

Readers responded enthusiastically to the contest, submitting nearly 250 images on all things chemical. Connected loosely by the broad theme, "Your Science Up Close," the photos in this collection range from the macroscopic to the microscopic and from the everyday lab scene to the "that wasn't supposed to happen." Winners will receive gift cards.

To see photos from the winners and honorable mentions, go to C&EN photo contest.

Concerns about the safety of certain 'healthful' plant-based antioxidants

Scientists are calling for more research on the possibility that some supposedly healthful plant-based antioxidants - including those renowned for their apparent ability to prevent cancer - may actually aggravate or even cause cancer in some individuals. Their recommendation follows a study in which two such antioxidants - quercetin and ferulic acid - appeared to aggravate kidney cancer in severely diabetic laboratory rats. The study appears in ACS' bi-weekly Journal of Agricultural and Food Chemistry.

Kuan-Chou Chen, Robert Peng, and colleagues note that vegetables, fruits, and other plant-based foods are rich in antioxidants that appear to fight cancer, diabetes, heart disease, and other disorders. Among those antioxidants is quercetin, especially abundant in onions and black tea, and ferulic acid, found in corn, tomatoes, and rice bran. Both also are ingredients in certain herbal remedies and dietary supplements. But questions remain about the safety and effectiveness of some antioxidants, with research suggesting that quercetin could contribute to the development of cancer, the scientists note.

They found that diabetic laboratory rats fed either quercetin or ferulic acid developed more advanced forms of kidney cancer, and concluded the two antioxidants appear to aggravate or possibly cause kidney cancer. "Some researchers believe that quercetin should not be used by healthy people for prevention until it can be shown that quercetin does not itself cause cancer," the report states. "In this study we report that quercetin aggravated, at least, if not directly caused, kidney cancer in rats," it adds, suggesting that health agencies like the U. S. Food and Drug Administration should reevaluate the safety of plant-based antioxidants.

Journal of Agricultural and Food Chemistry: "Quercetin and Ferulic Acid Aggravate Renal Carcinoma in Long-Term Diabetic Victims" [J. Agric. Food Chem., 2010, 58 (16), pp 9273?9280].

Small particles show big promise in beating unpleasant odors

Scientists are reporting development of a new approach for dealing with offensive household and other odors - one that doesn't simply mask odors like today's room fresheners, but eliminates them at the source. Their research found that a deodorant made from nanoparticles - hundreds of times smaller than peach fuzz - eliminates odors up to twice as effectively as today's gold standard. A report on these next-generation odor-fighters appears in ACS' Langmuir, a bi-weekly journal.

Brij Moudgil and colleagues note that consumers use a wide range of materials to battle undesirable odors in clothing, on pets, in rooms, and elsewhere. Most common household air fresheners, for instance, mask odors with pleasing fragrances but do not eliminate the odors from the environment. People also apply deodorizing substances that absorb smells. These materials include activated carbon and baking soda. However, these substances tend to have only a weak ability to absorb the chemicals responsible for the odor.

The scientists describe development of a new material consisting of nanoparticles of silica (the main ingredient in beach sand) - each 1/50,000th the width of a human hair - coated with copper. That metal has well-established antibacterial and anti-odor properties, and the nanoparticles gave copper a greater surface area to exert its effects. Tests of the particles against ethyl mercaptan, the stuff that gives natural gas its unpleasant odor, showed that nanoparticles were up to twice as effective as the gold standard - activated carbon - at removing the material's foul-smelling odor. In addition to fighting odors, the particles also show promise for removing sulfur contaminants found in crude oil and for fighting harmful bacteria, they add.

Langmuir: "Copper Coated Silica Nanoparticles for Odor Removal" [Langmuir, 2010, 26 (20), pp 15837?15844; DOI: 10.1021/la100793u].

Tobacco and its evil cousin, nicotine? They're good - as a pesticide!

Tobacco, used on a small scale as a natural organic pesticide for hundreds of years, is getting new scientific attention as a potential mass-produced alternative to traditional commercial pesticides. That's the topic of a report in ACS' bi-weekly journal Industrial & Engineering Chemistry Research.

Cedric Briens and colleagues note that concerns about the health risks of tobacco have reduced demand and hurt tobacco farmers in some parts of the world. Scientists are looking for new uses for tobacco. One potential use is as a natural pesticide, due to tobacco's content of toxic nicotine. For centuries, gardeners have used home-made mixtures of tobacco and water as a natural pesticide to kill insect pests. A "green" pesticide industry based on tobacco could provide additional income for farmers, and as well as a new eco-friendly pest-control agent, the scientists say.

They describe a promising way to convert tobacco leaves into pesticides with pyrolysis. That process involves heating tobacco leaves to about 900 degrees Fahrenheit in a vacuum, to produce an unrefined substance called bio-oil. The scientists tested tobacco bio-oil against a wide variety of insect pests, including 11 different fungi, four bacteria, and the Colorado potato beetle, a major agricultural pest that is increasingly resistant to current insecticides. The oil killed all of the beetles and blocked the growth of two types of bacteria and one fungus. Even after removal of the nicotine, the oil remained a very effective pesticide. Its ability of the oil to block some but not all of the microorganisms suggests that tobacco bio-oil may have additional value as a more selective pesticide than those currently in use, the report indicates.

Industrial & Engineering Chemistry Research: "Experimental Investigations into the Insecticidal, Fungicidal, and Bactericidal Properties of Pyrolysis Bio-oil from Tobacco Leaves Using a Fluidized Bed Pilot Plant" [Ind. Eng. Chem. Res., 2010, 49 (20), pp 10074?10079; DOI: 10.1021/ie100329z].

Cone of poison: The secret behind the cone snail's venom pump

Scientists have discovered the secret of how an amazing sea snail injects its venom after shooting a harpoon-like tooth into its prey - or some unlucky swimmer - at jetliner speeds. The creatures, called cone snails, use a highly specialized structure that instantly pumps the paralyzing venom through the tooth and into its target. Their study appears in ACS' monthly Journal of Proteome Research.

Helena Safavi-Hemami, Anthony Purcell and colleagues note that cone snails live mainly in the shallows of the world's tropical oceans. Prized by sea-shell collectors for their beautiful shells, the snails are up to 9 inches long. Their mouths have a blow-gun-like structure that shoots a barbed dart-like "tooth" at about 400 miles per hour. The tooth injects venom into fish, worms, or other prey. The snails occasionally sting swimmers, causing pain and sometimes death. They can reload the shooter with additional harpoons. The venom is produced in the venom duct, a long tube attached to the harpoon on one end and to the venom bulb in the snail's mouth.

The scientists' analysis of proteins in venom bulbs found high concentrations of arginine kinase, a protein that enables squid and scallops to swim away from danger with extreme speed. Its abundance in the bulb suggests that arginine kinase enables the venom bulb to undergo rapid, repeated contractions to quickly force the venom through the venom duct to the harpoon and into the prey, the scientists say. The scientists also identified specialized muscles in the venom bulb that appear to aid in this process.

Journal of Proteome Research: "Proteomic interrogation of venom delivery in marine cone snails ? Novel insights into the role of the venom bulb" [J. Proteome Res., DOI: 10.1021/pr100431x].

Probing the mysterious second-wave of damage in head injury patients

Why do some of the one million people who sustain head injuries annually in United States experience a mysterious second wave of brain damage days after the initial injury - just when they appear to be recovering? Limited clinical trials using an innovative new device to monitor brain chemistry on a second-by-second basis are underway to answer that life-and-death question, according to an article in the current issue of Chemical & Engineering News (C&EN), ACS' weekly newsmagazine. Brain injury is the leading cause of death and disability worldwide.

C&EN Senior Editor Celia Henry Arnaud describes a phenomenon called depolarization, in which brain activity decreases in patients following initial trauma. The condition involves a wave of chemical changes that spread from the site of injury and inactivate nerve cells. Since reactivation of these cells requires large amounts of glucose, monitoring glucose levels in a patient's brain can help doctors tell whether or not a patient is taking a turn for the worse. The article points out that a promising new device could provide a faster and more useful way to monitor brain glucose than current methods, which are inefficient.

Now in development at Imperial College London, the new so-called "microfluidic method" measures glucose quickly and continuously - in fractions of a second instead of hourly. The device is currently being tested in patients who have suffered trauma, stroke, or aneurysm (a balloon-like enlargement of a brain artery). In the future, the device could be used in patients with milder forms of brain injury and used in a way that is less invasive, the article notes.

Chemical & Engineering News: "Brain Glucose, Drop By Drop" [volume 88, number 43, pp. 48-49, October 25, 2010].

Black rice bran may help fight disease-related inflammation

Scientists are reporting evidence that black rice - a little-known variety of the grain that is the staple food for one-third of the world population - may help soothe the inflammation involved in allergies, asthma, and other diseases. Their study appears in ACS' bi-weekly Journal of Agricultural and Food Chemistry.

Mendel Friedman and colleagues point out that their previous research showed several potential health benefits of eating black rice bran. Bran is the outer husk of the grain, which is removed during the processing of brown rice to produce the familiar white rice. Those experiments, which were done in cell cultures, hinted that black rice bran suppressed the release of histamine, which causes inflammation.

In the new study, they tested the effects of black rice bran extract on skin inflammation in laboratory mice. When they injected the extract into the mice, it reduced skin inflammation by about 32 percent compared to control animals and also decreased production of certain substances known to promote inflammation. Brown rice bran extract did not have these effects, they say. When the scientists fed the mice a diet containing 10 percent black rice bran, it reduced swelling associated with allergic contact dermatitis, a common type of skin irritation. The findings "further demonstrate the potential value of black rice bran as an anti-inflammatory and anti-allergic food ingredient and possibly also as a therapeutic agent for the treatment and prevention of diseases associated with chronic inflammation," the article notes.

Journal of Agricultural and Food Chemistry "Protective Effects of Black Rice Bran against Chemically-Induced Inflammation of Mouse Skin" [J. Agric. Food Chem., 2010, 58 (18), pp 10007?10015; DOI: 10.1021/jf102224b].

Behind-the-scenes advances underpin new super-strong plastics

Long-awaited advances in reducing the cost of certain catalysts - substances that kick-start chemical reactions - have quietly led to production of super-strong forms of the world's most widely used plastics, according to the cover story of the current issue of Chemical & Engineering News (C&EN), ACS' weekly newsmagazine. These upgraded forms of polyethylene have led to availability of stronger, more durable consumer products ranging from garbage bags to camping cookware.

C&EN Senior Editor Alexander Tullo notes that the catalysts, called "metallocenes," engendered excitement years ago because they allowed production of stronger forms of polyethylene plastics. The world's most widely used plastic, polyethylene is a mainstay in plastic shopping bags and other items. However, hopes that metallocene plastics would replace conventional polyethylene plastics faded because of the high costs of these catalysts.

The article describes a revival in the use of metallocenes and expanded marketing of super-strong polyethylene plastics. The reason: New technologies have cut the catalysts' cost and fostered production of millions of tons of the new plastics. They are found in products such as stronger garbage bags, improved packaging materials, more durable fuel tanks, and tougher artificial turf for football and soccer fields.

Chemical & Engineering News: "Metallocenes Rise Again" [Volume 88, Number 42; Pages 10-16; October 18, 2010].

Biodegradable foam plastic substitute made from milk protein and clay

Amid ongoing concern about plastic waste accumulating in municipal landfills, and reliance on imported oil to make plastics, scientists are reporting development of a new ultra-light biodegradable foam plastic material made from two unlikely ingredients: The protein in milk and ordinary clay. The new substance could be used in furniture cushions, insulation, packaging, and other products, they report in the ACS' Biomacromolecules, a monthly journal.

David Schiraldi and colleagues explain that 80 percent of the protein in cow milk is a substance called casein, which already finds uses in making adhesives and paper coatings. But casein is not very strong, and water can wash it away. To beef up casein, and boost its resistance to water, the scientists blended in a small amount of clay and a reactive molecule called glyceraldehyde, which links casein's protein molecules together.

The scientists freeze-dried the resulting mixture, removing the water to produce a spongy aerogel, one of a family of substances so light and airy that they have been termed "solid smoke." To make the gossamer foam stronger, they cured it in an oven, then tested its sturdiness. They concluded that it is strong enough for commercial uses, and biodegradable, with almost a third of the material breaking down within 30 days.

Biomacromolecules: "Development of Biodegradable Foamlike Materials Based on Casein and Sodium Montmorillonite Clay" [Biomacromolecules, 2010, 11 (10), pp 2640?2646; DOI: 10.1021/bm100615a].

Progress toward treating infections by silencing microbes' 'smart phones'

So disease-causing bacteria in the body finally have multiplied to the point where their numbers are large enough to cause illness. What's next? They get out their "smart phones" and whisper "Let's roll!" That's how an article in ACS' monthly Chemical Reviews describes the substances - "smart phones of the microbial world" - that bacteria use to transmit chemical signals that launch infections and monitor their environment. The authors describe progress toward understanding and blocking this biochemical chitchat, a development that could lead to new treatments for the growing problem of antibiotic-resistant infections.

Marvin Whiteley and Holly Huse point out that bacteria use chemical signals to communicate with each other. These signals can trigger infections when their numbers reach a certain threshold - a process known as "quorum sensing." Scientists around the world are trying to find potential new drugs that garble or block those signals, and in doing so, fight infection. One prime target are the 4-quinolones, signaling molecules produced by Pseudomonas aeruginosa, a common disease-causing microbe.

Their review of more than 60 years of research on 4-quinolones found promising indications that such a conversation-stopper will be developed. Scientists, for instance, now have evidence that a certain enzyme that modifies 4-quinolones can reduce infection. "These results are encouraging for the development of new therapeutics that target 4-quinolone signaling," the article noted.

Chemical Reviews: "4-Quinolones: Smart Phones of the Microbial World" [Chem. Rev., Article ASAP; DOI: 10.1021/cr100063u].

Traveling by car increases global temperatures more than by plane, but only in long term

Driving a car increases global temperatures in the long run more than making the same long-distance journey by air according to a new study. However, in the short run travelling by air has a larger adverse climate impact because airplanes strongly affect short-lived warming processes at high altitudes. The study appears in ACS' Environmental Science & Technology, a semi-weekly journal.

In the study, Jens Borken-Kleefeld and colleagues compare the impacts on global warming of different means of transport. The researchers use, for the first time, a suite of climate chemistry models to consider the climate effects of all long- and short-lived gases, aerosols and cloud effects, not just carbon dioxide, resulting from transport worldwide. They concluded that in the long run the global temperature increase from a car trip will be on average higher than from a plane journey of the same distance. However, in the first years after the journey, air travel increases global temperatures four times more than car travel. Passenger trains and buses cause four to five times less impact than automobile travel for every mile a passenger travels. The findings prove robust despite the scientific uncertainties in understanding the earth's climate system.

"As planes fly at high altitudes, their impact on ozone and clouds is disproportionately high, though short lived. Although the exact magnitude is uncertain, the net effect is a strong, short-term, temperature increase," explains Dr. Jens Borken-Kleefeld, lead author of the study. "Car travel emits more carbon dioxide than air travel per passenger mile. As carbon dioxide remains in the atmosphere longer than the other gases, cars have a more harmful impact on climate change in the long term."

Environmental Science & Technology: "Specific Climate Impact of Passenger and Freight Transport" [Environ. Sci. Technol., 2010, 44 (15), pp 5700?5706; DOI: 10.1021/es9039693].

Electrified nano filter promises to cut costs for clean drinking water

With almost one billion people lacking access to clean, safe drinking water, scientists are reporting development and successful initial tests of an inexpensive new filtering technology that kills up to 98 percent of disease-causing bacteria in water in seconds without clogging. A report on the technology appears in Nano Letters, a monthly American Chemical Society journal.

Yi Cui and colleagues explain that most water purifiers work by trapping bacteria in tiny pores of filter material. Pushing water through those filters requires electric pumps and consumes a lot of energy. In addition, the filters can get clogged and must be changed periodically. The new material, in contrast, has relatively huge pores, which allow water to flow through easily. And it kills bacteria outright, rather than just trapping them.

The scientists knew that contact with silver and electricity can destroy bacteria, and decided to combine both approaches. They spread sub-microscopic silver nanowires onto cotton, and then added a coating of carbon nanotubes, which give the filter extra electrical conductivity. Tests of the material on E. coli-tainted water showed that the silver/electrified cotton killed up to 98 percent of the bacteria. The filter material never clogged, and the water flowed through it very quickly without any need for a pump. "Such technology could dramatically lower the cost of a wide array of filtration technologies for water as well as food, air, and pharmaceuticals where the need to frequently replace filters is a large cost and difficult challenge," their report states.

Nano Letters: "High Speed Water Sterilization Using One-Dimensional Nanostructures" [Nano Lett., 2010, 10 (9), pp 3628?3632; DOI: 10.1021/nl101944e].

Soft drink could enhance effects of an anti-cancer drug

Experiments with an artificial stomach suggest that a popular lemon-lime soft drink could play an unexpected role in improving the effectiveness of an oral anticancer drug. The experiments produced evidence that patients will absorb more of the unnamed drug, tested in Phase I in clinical trials, when taken with "flat" or degassed Sprite. The study appears in ACS' Molecular Pharmaceutics, a bi-monthly journal.

Faraj Atassi and colleagues note that efforts are underway to develop more anticancer medications that patients can take by mouth. However, biological variations among patients - due to variations in stomach acidity and other factors - can reduce the effectiveness of oral anticancer drugs. Such was the case with the unnamed anticancer drug in the study, identified only as "Compound X." There were wide differences in how the drug was absorbed in the first patients who took it.

The scientists combined Compound X with Captisol, a substance that helps improve the solubility of drug ingredients, and turned to the artificial stomach. That glass-and-plastic device is used to study how drugs and foods dissolve through the GI tract. They showed that Sprite seemed to control stomach acidity in a way likely to allow greater absorption of the drug into the body. Based on the results, the scientists suggest that patients in future clinical trials take the drug with Sprite.

Molecular Pharmaceutics: "Use of Artificial Stomach-Duodenum Model for Investigation of Dosing Fluid Effect on Clinical Trial Variability" [Mol. Pharmaceutics, 2010, 7 (5), pp 1533?1538; DOI: 10.1021/mp100116g].

New evidence that fat cells are not just dormant storage depots for calories

Scientists are reporting new evidence that the fat tissue in those spare tires and lower belly pooches - far from being a dormant storage depot for surplus calories - is an active organ that sends chemical signals to other parts of the body, perhaps increasing the risk of heart attacks, cancer, and other diseases. They are reporting discovery of 20 new hormones and other substances not previously known to be secreted into the blood by human fat cells and verification that fat secretes dozens of hormones and other chemical messengers. Their study appears in ACS' monthly Journal of Proteome Research.

Anja Rosenow and colleagues note that excess body fat can contribute to heart disease, diabetes, cancer and other diseases. Many people once thought that fat cells were inert storage depots for surplus calories. But studies have established that fat cells can secrete certain hormones and other substances much like other organs in the body. Among those hormones is leptin, which controls appetite, and adiponectin, which makes the body more sensitive to insulin and controls blood sugar levels. However, little is known about most of the proteins produced by the billions of fat cells in the adult body.

The scientists identified 80 different proteins produced by the fat cells. These include six new proteins and 20 proteins that have not been previously detected in human fat cells. The findings could pave the way for a better understanding of the role that hormone-secreting fat cells play in heart disease, diabetes, and other diseases.

Journal of Proteome Research: "Identification of novel human adipocyte secreted proteins by using SGBS cells" [J. Proteome Res., 2010, 9 (10), pp 5389?5401; DOI: 10.1021/pr100621g].

Insights into environmental conditions that affect highly pathogenic bird flu virus survival

On the eve of the 2010-11 influenza flu season, scientists and engineers have identified the environmental conditions and surfaces that could enable a highly pathogenic (H5N1) bird flu virus to survive for prolonged periods of time - at least two weeks and up to two months. Among them: The virus appears to thrive at cooler temperatures and low humidity. The study, which could lead to new strategies for preventing the flu virus from spreading, appears in ACS' Environmental Science & Technology, a semi-monthly journal.

Joseph Wood and colleagues note that the highly pathogenic (H5N1) avian influenza virus so far has been rare but dangerous in humans, with mortality rates of about 60 percent. Although the H5N1 virus may spread to humans by direct contact with infected birds or other virus-contaminated material, health experts are concerned that the virus could evolve to develop the ability to spread from person to person, and cause serious outbreaks. However, there is little information on how different environmental conditions and materials affect H5N1's survival.

The scientists investigated the ability of a strain of highly pathogenic H5N1 originating from Viet Nam to survive on a variety of materials under different environmental conditions, including changes in temperature, humidity, and simulated sunlight. The materials included glass, wood, steel, soil, and chicken feces. They found that H5N1 survived longer (up to two weeks) at cooler temperatures ? around 39 degrees Fahrenheit ? but lasted only up to one day at room temperature. The virus also tends to persist at low humidity and no sunlight and on certain surfaces, including glass and steel. Although when exposed to simulated sunlight, the virus survived longer on soil and chicken feces compared to the other materials. It could potentially survive for up to two months on those materials, they estimate. At low temperatures and low humidity, the virus actually survived longer on steel, glass, and soil than in chicken feces, a common source for spreading the virus. "Measures taken to contain and inactivate the virus, especially in these areas or conditions, may be warranted," the article notes.

Environmental Science & Technology: "Environmental Persistence of a Highly Pathogenic Avian Influenza (H5N1) Virus" [Environ. Sci. Technol., 2010, 44 (19), pp 7515?7520; DOI: 10.1021/es1016153].