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The control over ice crystal growth, melting, and shaping is important in a variety of fields, including cell and food preservation and ice templating for the production of composite materials. Control over ice growth remains a challenge in industry, and the demand for new cryoprotectants is high. Naturally occurring cryoprotectants, such as antifreeze proteins (AFPs), present one solution for modulating ice crystal growth; however, the production of AFPs is expensive and inefficient. These obstacles can be overcome by identifying synthetic substitutes with similar AFP properties. Zirconium acetate (ZRA) was recently found to induce the formation of hexagonal cavities in materials prepared by ice templating. Here, we continue this line of study and examine the effects of ZRA and a related compound, zirconium acetate hydroxide (ZRAH), on ice growth, shaping, and recrystallization. We found that the growth rate of ice crystals was significantly reduced in the presence of ZRA and ZRAH, and that solutions containing these compounds display a small degree of thermal hysteresis, depending on the solution pH. The compounds were found to inhibit recrystallization in a manner similar to that observed in the presence of AFPs. The favorable properties of ZRA and ZRAH suggest tremendous potential utility in industrial applications.

Serum beta-glucuronidase (S beta G) activity was investigated as an early indicator of diabetes in pregnant women. The enzyme activity was determined in the sera of three groups: nonpregnant women (18 to 40 years old) with and without glucose intolerance, pregnant women with and without glucose intolerance, and pregnant women with a family history of diabetes. The S beta G activity values (means +/- SD) in normal pregnant women were 603 +/- 223, 872 +/- 270 and 1,336 +/- 353 Fishman units during the three trimesters, respectively. A slight increase in S beta G activity was found in the sera of healthy pregnant women with a family history of diabetes during the first and second trimesters. High values of S beta G (2,765 +/- 392 units) were found in all stages of pregnancy in diabetic women. Thus, the determination of S beta G activity may be a valuable aid in the early detection of reduced glucose tolerance in pregnancy.