OBJECTIVE:To investigate the effects of application timing of carboporst tromethamine on postpartum hemor-rhage and hemodynamics of cesarean section women with centralplacenta previa. METHODS:Totally 138 parturient women with central placenta previa selected from our hospital during Jan.-Dec. 2015 were divided into observation group and control group ac-cording to random number table,with 69 cases in each group. Both groups received cesarean section. Control group was given Car-boporst tromethamine injection 250 μg on uterine body after the delivery of placenta. Observation group was given Carboporst tro-methamine injection 250 μg on corpora uteri immediately after umbilical cord cutting. The operation duration,intraoperative and postoperative blood loss were observed in 2 groups. The preoperative and postoperative 24 h hemodynamic index,coagulation func-tion and corpora uteri were compared between 2 groups. RESULTS:The operation duration of observation group was significantly shorter than control group;intraoperative blood loss and 24h blood loss of observation group were significantly less than control group,with statistical significance(P<0.05). There was no statistical significance in preoperative hemodynamic index and coagula-tion function index between 2 groups before surgery(P>0.05). 24 h after surgery,SBP,DBP,MAP,FIB and D-D of 2 groups were decreased significantly,while HR of them were increased significantly;the observation group was significantly better than the control group,with statistical significance (P<0.05). There was no statistical significance in the incidence of ADR (15.94% vs. 13.04%) between 2 groups (P>0.05). CONCLUSIONS:Carboporst tromethamine after omphalotomy via uterine body helps to shorten the operation time,reduce intraoperative blood loss,maintain hemodynamic indexes stable and improve coagulation func-tion of cesarean section women with central placenta previa ,with good safety.

Objective:To investigate gender measurement invariance of the Perceived Social Support Scale(PSSS)in people aged 50 years and older.Methods:A total of 1013 adults(50-96 years old)in Beijing, Hunan and Shandong were tested by using PSSS.The measurement invariance of PSSS between middle-aged and elderly males and females was analyzed.Differences in PSSS total scores and subscale scores between males and females were examined.Results:The equivalence test results of each item in the questionnaire met the requirements of the metrology(△CFI≥0.010, △TLI≥0.010, △RSMEA≤0.015), indicating that the hypotheses of morphological equivalence, weak equivalence, strong equivalence and strict equivalence of PSSS were all valid in the middle-aged and elderly population regardless of gender.In addition, middle-aged and elderly females had higher scores in family support, support from friends, support from other people and perceived social support than their male counterparts( P<0.05). Conclusions:PSSS has cross-gender equivalence in middle-aged and elderly people.Thus, differences in PSSS can reflect the perceived social support level in middle-aged and elderly people of different genders.