肝癌是全球最常见的恶性肿瘤之一，严重危害人类的身体健康。亚硝胺类化合物

Liver cancer is one of the most common malignant tumors in the world, which seriously endangers human health. Nitrosamine compounds are widely found in air, water, cigarette smoke, smoked barbecues, salted fish and other pickled vegetables, fried foods, and leftovers <br>. Liver cancer induced by nitrosamine compounds has become a major public health concern. problem. At present, it is known that many functions of human and animal bodies are affected by circadian rhythm changes. Under the same other conditions, the difference in the time of exposure in a day may lead to differences in the degree of toxicity of animals to the same dose of chemicals. DEN is a strong carcinogen. It is commonly used in scientific research to induce the formation of animal models of liver cancer. In this experiment, the sensitivity of DEN to liver cancer in rats was applied at different times.

Liver cancer is one of the most common malignant tumors in the world, which seriously endangers human health. Nitrosamine compounds are widely found in air, water, cigarette smoke, smoked meat, salted fish and other pickles, fried food, leftovers,<br>Liver cancer induced by nitrosamines has become a major public health problem. Many functions of known human and animal bodies are affected by changes in circadian rhythms, and other conditions, different times of the day can lead to differences in the degree of toxicity of animals to the same dose of chemicals. DEN is a strong carcinogen, commonly used in scientific research to induce the formation of animal models of liver cancer, this experiment applied DEN at different times to the induced sensitivity of liver cancer in rats

Liver cancer is one of the most common malignant tumors in the world, which seriously harms human health. Nitrosamines are widely used in air, water, cigarette smoke, smoked barbecue, salted fish and other pickles, fried foods and leftovers,<br>The hepatocarcinoma induced by nitrosamines has become a major public health problem. At present, it is known that many functions of human and animal body are affected by circadian rhythm. Under the same conditions, the different time of exposure in a day may lead to the difference of toxicity degree of animals to the same dose chemicals. Den is a strong carcinogen, which is often used in scientific research to induce the formation of liver cancer animal model. In this experiment, den is used to induce the sensitivity of den to rat hepatoma at different times<br>