Objective To evaluate the relationship between myocardial perfusion imaging quality and reconstruction time of dual-souce CT (DSCT).Methods Myocardial perfusion imaging was performed in 28 subjects using second-generation DSCT.The coronary arteries of all selected subjects were normal.280 ms temporal resolution was used,and the image of 30 ％-80 ％ R-R phase was reconstructed by retrospective ECG gating interval 5 ％.The artifact area of myocardial perfusion iodine map image of each R-R interval were obtained.Average segment artifacts of the heart bottom,central,apical,apical level of heart level were calculated and statistical analyzed.Results The artifact area of myocardial perfusion iodine map of the heart bottom,central,apical,and the whole heart had statistically significant differences (all P＜0.01),and the minimum artifact area was in60％ R-R phase ([0.31±±0.28]cm2,[0.18±0.23]cm2,[0.13±0.13]cm2,[0.22± 0.18]cm2).There was no difference between different phases of the heart apical level (P=0.634).The minimum artifact area of myocardial perfusion iodine map of the heart bottom,central,apical,apical level in 60％ R-R phase at the heart apical,the difference had statistically significant (F 3.701,P=0.014),there was no difference between the heart apical and central (P＞0.05),but the difference between the heart apical and other parts had statistically significant (P＜0.05).Conclusion Using 280 ms temporal resolution,second-generation DSCT can achieve the optimal myocardial perfusion imaging quality using 60％ R-R phase reconstruction.

Objective To explore the potential mechanism of"hot flashes"in mice with type 2 diabetes with yin deficiency syndrome.Methods Ninety-nine 8-week-old db/db mice with fasting blood glucose≥16.7 mmol·L-1 were divided into yin deficiency syndrome group,type 2 diabetes group,type 2 diabetes with yin deficiency syndrome group,type 2 diabetes with Liuwei Dihuang Decoction low,medium,high-dose group,type 2 diabetes with yin-deficiency syndrome and Liuwei Dihuang Decoction low,middle,high-dose groups,21 littermates of wild control male m/m mice were control group.The model was established by the method of"heat engenders yin deficiency",and the performance of yin deficiency syndrome in mice was evaluated after 4 weeks.Afterwards,the corresponding doses of Liuwei Dihuang Decoction group were given by gavage for 4 weeks.During the experiment,the rectal temperature,the temperature of the precordial area,and the temperature of the limbs and paws were measured once a week at 8:30,15:00,and 20:00.Western blot was used to observe the expression of biological rhythm-related proteins in the hypothalamus and liver.Results The experimental study showed that the yin deficiency syndrome model of type 2 diabetes could be established by using the method of overheating and injuring the yin.The rhythm changes of Liuwei Dihuang Decoction showed that the high-dose group could effectively restore the body temperature rhythm.The expression of rhythm factors Clock and Cry2 increased in both the hypothalamus and liver;in the hypothalamus,the central rhythm regulation center,the expressions of Per2 and Cry2 increased significantly;in the peripheral target organ liver,the expressions of Bmal1,Per3 and Cry1 increased more significantly.Conclusion The abnormal expression of biological rhythm protein in the liver and hypothalamus may be one of the important mechanisms leading to the characteristics of"hot flashes"in type 2 diabetes with yin deficiency.