Parathyroid hormone (PTH) function as immunologic mediator has become interesting with the recent usage of PTH analogue (teriparatide) in the management of osteoporosis. Since the early 1980s, PTH receptors were found on most immunologic cells (neutrophils, B and T cells).
But, the refrigerator will only keep food safely cold for about four hours if unopened during a power outage, according to the USDA. A full freezer will hold the temperature for about 48 hours if full (24 hours of half full), the USDA says. Generally, if the temperature in the thermometer in the freezer reads 40 degrees Fahrenheit or below, the food is safe and can be refrozen, according to the USDA.
Here are basic tips for keeping food safe: 1  Keep the refrigerator and freezer doors closed as much as possible to maintain the cold temperature. 2  Buy dry or block ice to keep the refrigerator as cold as possible if the power is going to be out for a prolonged period of time. Fifty pounds of dry ice should keep an 18 cubic foot, fully stocked freezer cold for two days.