Methods Human hepatocellular cancer cell line HepG2 were treated with different concentrations of leech extracts which were extracted by method of freeze-thawing with liquid nitrogen and contrasted with that by method of water extracting and ethanol precipitating.

Study on freezing technology of Pleurotus ferulate varnebrodensis lenzi by liquid nitrogen quick freezing;

Slow freezing and liquid nitrogen quick freezing by spray fluidization were compared in an experiment with Tricholoma matsutake.

The Boletus aereus freezing pattern was studied through analyzing the freezing curve at different temperature, freezing speed and juice leakage by liquid nitrogen flash freezer.

The cantharellus cibarius freezing technics was studied through analyzing the freezing curve at different temperature,freezing speed and juice leakage by liquid nitrogen flash freezer.

In order to maintain the freshness,color,deliciousness and flavor of foods,the carbon dioxide fast freezing machine has been developed on basis of liquid carbon dioxide spray refrigerating principle,and food may swiftly pass through the ice crystal band by using this machine.

It means that the fast freezing of this shaft is actual.

The liquid nitrogen freezing construction practice of the equipment foundation of Nantun aluminum casting workshop

Experiment on uniformity of temperature field in liquid nitrogen freezing

The samples at different reaction states were obtained by liquid nitrogen freezing in the process of collagen biomineralization.