Objective To explore the impact of pre-setted generation adaptive statistical iterative reconstruction Veo (ASiR-V) on chest CT radiation dose and image quality.Methods The chest model and 120 patients (divided into 6 groups,each n=20) were scanned by GE Revolution CT under the condition of pre-setted ASiR-V weights for 0,20％,40％,60％,80％ and 100％ respectively.The tube voltage was 120 kV,the tube current was automated mAs (Smart mA10-500) technology,the noise index was 11.The dose-length product of each chest model group and patients group were record,the effective dose (ED) of each group was calculated and compared.The image quality among groups through combining the objective CT and standard deviation (SD) values of different organizations (lung tissue,the soft tissue near by spine,the aorta and vertebral body) in chest model and the image subjective rating of patients were compared,and the subjective score of patients' images was also compared among groups.Results With the increase of pre-setted ASiR-V,the ED of chest model and patients reduced as a logarithmic fitting,there are no obvious changes of the CT value and image noise SD value of different organizations in model.The subjective score of mediastinal and pulmonary window was begin to decline at 40％ weighted ASiR-V.The subjective score of mediastinal and pulmonary window descend obviously at 60％ weighted ASiR-V compare to 40％ (P＜0.05).ED of pre-setted 40％ weighted ASiR-V reduced to 57.21％ compared to that of 0 weighted ASiR-V.Conclusion The pre-setted ASiR-V can reduce the radiation dose,and does not affect the objective image quality at the same time.The pre-setted 40 ％ weighted ASiR-V has the highest clinical application value due to the radiation dose can be obviously reduced with ensuring the image quality,which can meet the demand of diagnosis.

Objective To investigate the regulation of SIRT1 on ovarian granulosa cell in women with poor ovarian response.Methods A total of 60 women who underwent IVF/ICSI-ET were included in this study,30 women in poor ovarian response(POR)group and 30 women in normal ovarian response(NOR)group.The granulosa cells in follicular fluid were isolated and purified by density gradient centrifugation.The granulosa cells of POR group were treated with SIRT1 agonist resveratrol(RESV)or inhibitor EX527,respectively,and the control group was granulosa cells treated without drugs.mRNA levels of SIRT1 and key enzymes of steroid hormone synthesis(StAR,CYP19,CYP17)in granulosa cells were detected by qPCR.The levels of SIRT1,steroid hormone synthesis key enzymes protein and apoptosis-related protein(Bcl-2,Caspase-3)in granulosa cells were detected by Western blot.The apoptosis rate of granulosa cells was detected by TUNEL method.Determination of estradiol in granulosa cell culture medium by chemiluminescence.Results The mRNA and protein levels of SIRT1 in granulosa cells in POR group were lower than those in NOR group(P = 0.003,P<0.001).RESV up-regulated SIRT1 mRNA and protein levels(P<0.001),up-regulated mRNA and protein levels of steroid hormone synthesis key enzyme(P<0.05).EX527 down-regulated SIRT1 mRNA and protein levels(P = 0.023,0.001),down-regulated mRNA and protein levels of steroid hormone synthesis key enzymes(P<0.05).After RESV treatment,the apoptosis rate of granulosa cells was decreased(P<0.001),the Bcl-2 protein level was increased(P<0.001),and the Caspase-3 protein level was decreased(P<0.001).After EX527 treatment,the apoptosis rate of granulosa cells was increased(P<0.001),the Bcl-2 protein level was decreased(P = 0.003),and the Caspase-3 protein level was increased(P<0.001).Conclusion The SIRT1 level in granulosa cells of POR women was lower than that of NOR women.RESV up-regulated SIRT1 expression in granulosa cells.SIRT1 inhibited granulosa cell apoptosis,increased the level of steroid hormone synthesis key enzyme,and promoted estradiol synthesis in granulosa cell.Therefore,SIRT1 activators such as RESV may be a therapeutic agent to improve ovarian reactivity and increase the number of oocytes obtained in women with POR.