n e w s of t h e w e e k

they will seek out small-molecule drugs that target different forms of DNA as a means to control gene expression.

Barton comments that "a specific role for the Z-DNA conformation in vivo has remained elusive. Perhaps [WP900], in showing selectivity for Z-DNA and driv­ing transitions, might be useful in explor­ing therapeutic consequences of Z-DNA targeting. However, the binding affinities of the compounds are modest, and it will be quite a challenge to establish such tar­geting in vivo."

Stu Borman

Magnesium Systems Could Rival Current Lead-Acid Batteries

Rechargeable magnesium battery sys­tems developed in Israel could rival the performance of environmentally prob­lematic batteries used in electric vehi­cles and other heavy-load applications, according to the discovery team.

The prototype systems, devised by Doron Aurbach, head of the electro­chemistry group, and coworkers at Bar-Ilan University, Ramat Gan, comprise a magnesium metal anode; novel electro­lyte solutions based on magnesium-organohaloaluminate salts; and a cath­ode made from a novel material that contains magnesium, molybdenum, and sulfur [Nature, 407, 724 (2000)].

The group notes that magnesium is abundant, inexpensive, easy to handle, environmentally benign, and—because the metal is light—has potential as a high-energy-density power source. Re­chargeable lead-acid and nickel-cad­mium batteries currently employed in large-scale energy conversion, on the other hand, contain heavy metals that are highly toxic.

"Our battery systems are green, can deliver thousands of charge-discharge cycles with very little capacity fading, and are operational over a wide temperature range," Aurbach tells C&EN. 'They have a very long shelf life and are expected to be cheaper than other rechargeable bat­tery systems on the market."

According to Jeffrey R. Dahn, a phys­ics and chemistry professor at Dalhou-sie University, Halifax, Nova Scotia, and an expert on battery materials, the work is impressive. "I don't think anyone has developed a rechargeable magnesium system before that was worth anything,"

he remarks. "The fact that the group can achieve so many charge-discharge cycles with very low capacity fading is amazing."

Dahn explains that one of the main problems that has hindered development of magnesium systems in the past has been the reaction of magnesium anodes with electrolytes, resulting in growth of passivating surface films on the anodes that inhibit electrochemical reactions.

"The magnesium electrodes are not passivated in the electrolyte systems used by Aurbach's group," Dahn says. "That's really important because it gives the 100% cycling efficiency of the mag­nesium that is required for the long cy­cling life of the system."

Aurbach and colleagues point out that their present results are only the first step in the development of this technology. The team is working on in­creasing the voltage of its batteries and notes that the energy density of re­chargeable magnesium batteries could be considerably increased by modifying the cathode by, for example, doping with electropositive atoms.

Michael Freemantle

Asbestos Drives Owens Corning Into Bankruptcy Building and composite materials maker Owens Corning has filed for reorganiza­tion under Chapter 11 of the U.S. Bank­ruptcy Code. A flood of new liabilities related to its long-dismantled as­bestos products business and cooling demand for its current portfolio were more than the company could bear.

Owens Corning has already agreed to pay $5.2 billion to people whose health has been impaired because of the use of asbestos insulation it sold un­der the Kaylo brand name between 1952 and 1972. The amount covers more than 320,000 claims evaluated before and af­ter a national settlement program was set up almost two years ago.

Owens Corning has an additional 150,000 claims pending under the na­tional settlement program—totaling about $1.3 billion—and another 30,000 claims from people who are not partici­pating in the program. The total payout for these suits has yet to be resolved.

OWENS CORNING

The company is also a victim of ris­ing interest rates and easing demand for its glass fiber insulation and other build­ing products. For the second quarter of 2000, its net sales decreased 1% to less than $1.3 billion.

Owens Corning is not going out of business, only negotiating with credi­tors on how it can best reorganize to meet its obligations. That may involve setting up a trust, which would be sepa­rate from the company, to handle the claims and insulate the company itself from mounting liabilities.

The company has been given a $500 million line of credit from the Bank of America to keep its business afloat. During the Chapter 11 proceedings, the company will suspend payments for div­idends, on unsecured debt securities, and to asbestos claimants.

"Until very recently, we thought Chapter 11 could be avoided," says Glen H. Hiner, Owens Coming's chairman and chief executive officer, noting that the company tried out-of-court settle­ments and legislative and judicial relief and formed its national settlement pro­gram, all to manage the liabilities. "However, the cost of resolving current and future claims, together with a flurry of recent new filings from plaintiff law­yers not participating in the [national settlement program], led us to the con­clusion that a Chapter 11 reorganization was prudent and necessary."

Companies facing similar circum­stances because of as­bestos have, on average, been in Chapter 11 for six years, Owens Corn­ing says. Hiner hopes that the company can re­solve these issues in half that time.

Other makers of as­bestos products have weighed in on Owens Coming's predicament. W.R. Grace, which has

its own liabilities and is paying more than $1 billion in damages, says it is important for companies facing such turmoil to be healthy so they can compensate their claimants.

USG Corp. distanced itself from Owens Coming. "USG Corp. is in a very different situation than Owens Corning. USG's cash flow and balance sheet are strong, and U.S. Gypsum's asbestos exposure has historically been far less than theirs," says William C. Foote, USG's chairman.

Alex Tullo

8 OCTOBER 16, 2000 C&EN