Objective To study the CT manifestations of delayed traumatic hematomas of the brain and evaluate their diagnostic significance in predicting the delayed traumatic brain hematoma. Methods The manifestations of initial CT studies and follow-up CT examinations of 31 delayed traumatic brain hematomas were analyzed. Another 50 CT studies of head trauma without delayed brain hematomas were included randomly as control. Results The abnormal findings of CT studies of the 31 delayed traumatic brain hematomas included: (1)Decreased density of the local brain parenchyma and disappeared difference between gray and white matter of the same area in 18 cases; (2)Local subarachnoid space hemorrhage in 24 cases; (3)Slight mass effect of local brain parenchyma in 16 cases. (4)Subdural hematoma in 9 cases. The locations of the abnormalities were roughly the same with the delayed hematoma except one local subarachnoid space hemorrhage, which was in the opposite of the delayed hematoma. The appearing rate of those abnormal findings in the control group was low and the difference was statistically significant. Conclusion The decrease of density of local brain parenchyma, the disappeared difference between the gray and white matter, local subarachnoid space hemorrhage, and local swollen of brain presented in the initial CT study of the patient with head trauma should be taken as indicators of delayed hemorrhage of the same area of brain, and it is necessary to do follow-up CT studies to exclude it.

Objective : To investigate the effect of riboflavin on inactivation of pathogens under different light time conditions． Methods : Plasma containing vesicular stomatitis virus (VSV) was divided into 4 groups，and the final concentrations of riboflavin were 50，100，150 μmol / L and 0 μmol / L was used as the control group．The growth titers at 10，15，20 and 25 min were observed．The control group was treated with no light．The growth titers of VSV culture before and after inactivation were calculated by Reed-Muench method，and the effect of different concentrations of riboflavin on the inactivation effect was evaluated by log reduction factor after inactivation. Results : Under the condition of no light，the addition of riboflavin had no pathogen inactivation effect．With the increase of light time from 15 min to 25 min，the inactivation effect of VSV in the non-riboflavin group increased．When the light was less than 15 min，there was no significant difference in the inactivation effect of 50 to 150 μmol / L riboflavin VSV．When the light duration was 15 to 25 min，the inactivation effect of VSV was enhanced after the addition of riboflavin，but there was no difference between different concentrations of riboflavin groups． Conclusion The inactivation effect of riboflavin pathogen within 25 min is better with the increase of light time，and has little influence on riboflavin concentration.