#96-11

Contact: Mona S.Rowe,(516) 282-2345 or
Diane Greenberg, (516) 282-2347

Mailed 2/14/96

BNL SPOTLIGHTS

"BNL Spotlights" is issued quarterly to bring you up to date on some of the latest newsworthy developments at the U.S. Department of Energy's Brookhaven National Laboratory. Periodically, we focus on Brookhaven's user facilities, and, in 1993, we reported on a few promising research projects at the National Synchrotron Light Source. In the future, we plan to issue an update on the Relativistic Heavy Ion Collider, now under construction at Brookhaven. In this report, we are focusing on research conducted at Brookhaven's High Flux Beam Reactor (HFBR), one of the world's major research facilities. Each year, the HFBR attracts approximately 250 scientists from industry, universities and other laboratories to conduct forefront research using neutrons as probes for experiments in physics, chemistry and biology.

For more information on any of these items, call Diane Greenberg or Mona S. Rowe at BNL's Public Affairs Office.

PREVENTING POTHOLES --

The January thaw brought a new crop of potholes to the nation's roads and highways. The freeze-thaw cycle, however, must be accompanied by moisture to create potholes. Roads are paved with a mixture of gravel and asphaltine, a byproduct of oil. When a thin layer of water coats the gravel, the asphaltine separates from it, creating potholes.

At the High Flux Beam Reactor, scientists from BNL, Exxon and the State University of New York at Stony Brook are currently testing a material that may make potholes obsolete. They are adding sulfur and a polymer to the gravel and asphaltine mixture to create a compound that will not fall apart when exposed to moisture. By reflecting neutrons from the surface of a composite of these materials, the scientists can measure its ability to stick together when it is placed in water.

STUDYING MICROEMULSIONS
FOR CLEANING UP OIL SPILLS --

Researchers from BNL, Exxon and the Massachusetts Institute of Technology are using neutron beams from the High Flux Beam Reactor as probes to study microemulsions that can be applied to clean up oil spills. These microemulsions are spherical aggregates of large molecules that make efficient contact with both water and organic solvents: In a predominantly aqueous environment, they coat oil, and in a mainly oily environment, they emulsify water droplets. The researchers are investigating the chemistry and physical properties of microemulsions under various temperatures and chemical conditions to determine which would be optimal forcleaning up oil spills and, in another application, for solubilizing oil buried deep in wells so that it may be flushed out.

HOW BLOOD CLOTS ARE DISSOLVED --

Heart disease is still the number one cause of death among Americans, and basic research at Brookhaven's High Flux Beam Reactor (HFBR) and National Synchrotron Light Source (NSLS) may help to prevent it. Blood clots in arteries or veins cause heart attacks and strokes, and the Brookhaven scientists are studying how the body dissolves such blood clots naturally. Experiments at the HFBR have shown that when a molecule called plasminogen found in blood binds to blood clots, it undergoes a change in structure that enables it to dissolve the blood clot quickly and efficiently. This change in structure is the largest ever seen in a protein.

The scientists are now trying to grow plasminogen crystals. If successful, the crystals can be bombarded with x-rays at the NSLS to determine the placement of atoms in plasminogen and to understand how the atoms in plasminogen change when bound to a blood clot. This structural information would be very useful in the design of new drugs to prevent heart attack and stroke.

SPEEDING UP THE HUMAN GENOME PROJECT --

The Human Genome Project, a national endeavor to sequence, or decode, all human genes, holds great promise for increasing scientists' understanding of human biology and preventing or curing genetic diseases. But the project is huge: There are 100,000 human genes, formed from DNA containing three billion base pairs of information.

Scientists from BNL and the State University of New York at Stony Brook are developing a technology to speed up and automate the process of determining the sequence of these three billion base pairs. A critical step in the process is separating DNA fragments. The current technology uses an electrochemical process called electrophoresis, which requires that DNA fragments move through a gel. The gel is very laborious to make and to use. Substituting a clear, synthetic polymer solution in electrophoresis is a much faster way to separate the DNA fragments and is much easier to automate. The polymer solutions we are investigating for this purpose are composed of entangled networks of molecules in water that act like a sieve, separating DNA fragments in tiny capillary tubes. The challenge is to find polymer solutions that provide adequate separation and also are able to flow into the tiny capillary tubes.

Scientists at the High Flux Beam Reactor are using a technique called neutron scattering to study the physical properties of polymer solutions. Understanding how these properties relate to the ability to separate DNA fragments should lead to the development of improved polymer solutions for DNA sequencing.

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