ACS News Service Weekly PressPac: July 18, 2007

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• Toward Giving Artificial Cells the Ability to Move
• Nano-Sized Generator Gets Big Power Boost
• Automobile Brake Linings, Tires Remain Major Sources of Toxic Metals
• Fingerprinting With Light Shows Promise for Improved Crime-Fighting
• Sandpaper: Ancient Invention Increasingly Becomes High-Tech Marvel

Got legs? Chemists in Japan and Italy are reporting development of self-propelled oil droplets that could provide a basis for giving artificial cells the ability to move. Their collaborative study from the University of Tokyo and Protolife in Venice is scheduled for the August 8 issue of the Journal of the American Chemical Society (JACS), a weekly publication.

Tadashi Sugawara and colleagues note that efforts to make artificial cells have focused partly on genetics and enabling such cells — which could become biofuel factories and other technological advances — to reproduce. Sugawara’s group previously reported a self-reproducing lipid capsule in JACS. Scientists in the United States recently announced successful transplantation of a bacterial genome, an achievement described as a major step toward creating synthetic forms of life.

The new study focuses on “another essential and perhaps more fundamental characteristic of cells, the ability to move.” In laboratory experiments, the researchers showed that an oil droplet, used to represent an artificial cell, underwent sustained movement through a chemical solution for several minutes until finally coming to a stop. In doing so, the researchers say, the droplet demonstrated a “primitive form of chemotaxis,” one of the most basic cellular responses in which the cell directs its movement toward the presence of certain chemicals in its environment. The study could provide a blueprint for designing future locomotion systems for artificial cells, the scientists suggest.

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Particles worn away from automobile brake linings and tires continue to be major sources of potentially toxic metal emissions in urban areas, despite new regulations and auto industry efforts to reduce use of the metals, researchers in Sweden conclude in a report scheduled for the August 1 issue of ACS’ Environmental Science & Technology, a semi-monthly journal.

In the study, David S. T. Hjortenkrans and colleagues compared metal emissions from brake linings and tires to other metal emission sources in Stockholm during 1995 and from 1998-2005. During this period, copper and zinc emissions from brake linings remained relatively unchanged at high levels that make them a major source of these metals, the researchers said. Brake linings were also a source of another toxic metal, antimony. By contrast, lead and cadmium emissions from brake linings decreased by one-tenth during this period.

The study found that metal emissions from tire tread rubber declined between 1995 and 2005, as manufacturers reduced metal concentrations in tire treads. Tires, however, remained one of the largest sources of zinc and an important source of cadmium. “As Stockholm represents a rather average city in most respects, the results from this study may be relevant for many other urban areas,” the report stated.

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Sandpaper, a seemingly simple tool for smoothing out rough surfaces, is much more complex than meets the eye and has increasingly become a high-tech marvel, according to an article scheduled for the July 23 issue of Chemical & Engineering News (C&EN), ACS’ weekly newsmagazine. Whether honing medical implants or shaping-up jet turbine blades, improved sanding techniques are smoothing the way toward technological progress.

First used by the Chinese as early as the 13th century, sandpaper has evolved from an amalgam of crushed seashells bonded to parchment paper into “a highly sophisticated process,” notes C&EN associate editor Linda Wang. The design of modern sandpaper, technically called a ‘coasted abrasive,’ involves a complex interplay between the chemical properties of the abrasive material, adhesive, and the backing material, notes Wang. In her short feature, one of the ongoing series known as What’s That Stuff, she interviews several experts on the topic, including a representative from industry giant and sandpaper pioneer 3M.

Abrasives, or the gritty particles on sandpaper, can range from natural minerals, such as garnet or emery, to synthetic materials, such as fused aluminum oxide or silicon carbide. Choosing an abrasive can be a tricky task, the article notes, as many materials can chemically react with the material being sanded or are too expensive for practical use.

But today, computer programs can take the guesswork out of making sandpaper by modeling how an abrasive will perform, while the electron microscope has been used to optimize the structure of the tiniest abrasives. With the development of stronger materials, scientists have correspondingly developed stronger abrasives and improved bonding agents to allow for more aggressive sanding. From simple woodwork to high-end machining, “there’s just no alternative to sandpaper,” Wang notes.

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• General Chemistry Glossary
  The General Chemistry Glossary is an online resource that can help you to find definitions to common—and uncommon—chemical terms.
• New ACS Annual Report
  The 2006 ACS annual report, A New Vision at Work, can be a valuable resource for journalists trying to keep pace with chemistry and the multiple fields of science that involve chemistry. The report features a series of commentaries by chemists, including Nobel Laureate Robert H. Grubbs, on chemistry’s role in working toward better medications, more nutritious food, sources of renewable energy, and other innovations.

• ACS Updates: Hot research that can be a treasure trove for journalists seeking news and feature topics, or trying to keep current in rapidly-evolving scientific disciplines.
  
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  Summaries of key research articles on water analysis and emerging contaminants published mainly from 2005-2006. View these articles online or download the PDF.
  
  Science Elements: New ACS Podcast
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  Sustainability Pledge from World’s Top Chemical Societies
  Presidents of six leading chemical societies, meeting in Paris, have pledged to cooperate in promoting sustainable development, responsible use of natural resources, and other efforts in which scientists protect and maintain the earth’s environment, resources, and inhabitants. The statement came from the American Chemical Society, the Royal Society of Chemistry, the Chemical Society of Japan, the German Chemical Society, the French Chemical Society and the Dutch Chemical Society, which have a combined membership of nearly 300,000.

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News media registration is now open for the 234^th ACS National Meeting, which will be held in Boston, MA on August 19-23, 2007 at the Boston Convention and Exhibition Center and more than a dozen hotels across the city. More than 16,000 scientists and others are expected to attend this scientific extravaganza. There will be more than 9,500 presentations on new discoveries in chemistry, health, medicine, energy, environment, food, and other fields. The theme: “Biotechnology for Health and Wellness.”

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