A pinch of iron dramatically boosts the cooling performance of a material considered key to the development of magnetic refrigerators, and human tissue now can be chilled without ice-crystal formation.

Researchers at the National Institute of Standards and Technology of the U.S. Department of Commerce report that by adding a small amount of iron (about one percent by volume), they enhanced the effective cooling capacity of so-called "giant magnetocaloric effect" material by 15 to 30 percent. The results reported in the Summer/Fall issue of NIST's "At a Glance" newsletter, "is a much-improved magnetic refrigerant for near-room-temperature applications."

According to NIST, the original material, a gadolinium-germanium-silicon alloy, already is considered an attractive candidate for a magnetic refrigerant. However, its cooling potential is undercut by significant energy costs exacted during the on-off cycling of an applied magnetic field, the process that drives the refrigeration device. The iron supplement nearly eliminates cycling inefficiencies. Magnetic refrigerators offer improved energy efficiency, lower operating costs, elimination of environmentally damaging coolants, and nearly noise- and vibration-free operation. For more details, contact Robert Shull at (301) 975-6035.

With support from NIST's Advanced Technology Program and the National Institutes of Health, a private company -- Organ Recovery Systems of Chicago -- has patented a process in which body tissues such as blood vessels, cartilage and skin can have their suitability for transplantation prolonged. The tissues, as well as whole organs such as kidneys, livers and hearts, could become more widely available for transplants because the method chills the tissues and organs well below freezing without forming ice crystals.

Presently, organs and some tissues are stored for short periods at refrigerator temperatures but freezing has not been possible because ice crystals damage delicate cells which reduces the tissues' viability or functions.

The company's procedure uses a mixture of "cryoprotectant" compounds that reduce ice formation and minimize toxicity, along with careful control of the cooling and warming processes to minimize damage to the tissue.

For more information contact Kelvin Brockbank at (843) 514-6164; kbrockbank@organ-recovery.com.