[Association between prenatal exposure to PM2.5 and fetal growth: a prospective cohort study].

Objective: To investigate the association of exposure to PM2.5 and its constituents during pregnancy and fetal growth and to further identify critical windows of exposure for fetal growth. Methods: We included 4 089 mother-child pairs from the Jiangsu Birth Cohort Study between January 2016 and October 2019. Data of general characteristics, clinical information, daily average PM2.5 exposure, and its constituents during pregnancy were collected. Fetal growth parameters, including head circumference (HC), abdominal circumference (AC), and femur length (FL), were measured by ultrasound after 20 weeks of gestation, and then estimated fetal weight (EFW) was calculated. Generalized linear mixed models were adopted to examine the associations of prenatal exposure to PM2.5 and its constituents with fetal growth. Distributed lag nonlinear models were used to identify critical exposure windows for each outcome. Results: A 10 µg/m3 increase in PM2.5 exposure during pregnancy was associated with a decrease of 0.025 (ß=-0.025, 95%CI: -0.048- -0.001) in HC Z-score, 0.026 (ß=-0.026, 95%CI: -0.049- -0.003) in AC Z-score, and 0.028 (ß=-0.028, 95%CI:-0.052--0.004) in EFW Z-score, along with an increased risk of 8.5% (RR=1.085, 95%CI: 1.010-1.165) and 13.5% (RR=1.135, 95%CI: 1.016-1.268) for undergrowth of HC and EFW, respectively. Regarding PM2.5 constituents, prenatal exposure to black carbon, organic matter, nitrate, sulfate (SO42-) and ammonium consistently correlated with decreased HC Z-score. SO42- exposure was also associated with decreased FL Z-scores. In addition, we found that gestational weeks 2-5 were critical windows for HC, weeks 4-13 and 19-40 for AC, weeks 4-13 and 23-37 for FL, and weeks 4-12 and 20-40 for EFW. Conclusions: Our findings demonstrated that exposure to PM2.5 and its constituents during pregnancy could adversely affect fetal growth and the critical windows for different fetal growth parameters are not completely consistent.

[Effect of femtosecond laser-assisted phacoemulsification on corneal endothelium and prognosis of diabetic patients with cataract with different nuclear hardness].

Objective: To assess the impact of femtosecond laser-assisted phacoemulsification on corneal endothelial characteristics and prognosis among patients with type 2 diabetes and age-related cataracts, considering varying nuclear hardness. Methods: This non-randomized controlled trial involved 161 patients (161 eyes) with type 2 diabetes undergoing cataract extraction at Weifang Eye Hospital between March 2020 and December 2022. The cohort comprised 73 males and 88 females, with an average age of (65.9±5.23) years. Based on patient preference, 101 individuals underwent conventional phacoemulsification (group A), while 60 chose femtosecond laser-assisted phacoemulsification (group B). Patients were further stratified based on Emery-Little grade of lens nuclei into A1/B1 (grade Ⅰ and Ⅱ), A2/B2 (grade Ⅲ), and A3/B3 (grade Ⅳ) subgroups. The study compared effective phacoemulsification time (EPT), cumulative energy release of phacoemulsification (CDE), central corneal thickness (CCT), endothelial cell density (ECD), coefficient of variation (CV), and hexagon cell ratio (HEX) before and after surgery at 1 day, 1 week, 1 month, and 3 months. Results: The intraoperative EPT of patients in groups A and B were (6.52±4.93) and (5.63±4.31)s, respectively, and the CDE were 11.57%±5.21% and 10.68%±6.02%, respectively. The differences between them were not statistically significant (all P>0.05).There were no significant differences in EPT and CDE between groups A1 and B1 (all P>0.05), and there were statistically significant differences between groups A2 and B2, A3 and B3 (all P<0.05).The postoperative CCT was increased in both groups.There were no statistically significant differences in CCT between A1 and B1 groups at different time after surgery (all P>0.05), and there were statistically significant differences in CCT between A2 and B2, A3 and B3 groups at 1 day and 1 week after surgery (all P<0.05), and group B was significantly lower than group A.There was no significant difference between 1 month and 3 months after surgery (P>0.05).ECD was reduced in both groups.There was no statistically significant difference in ECD at different time of operation between A1 and B1 groups (all P>0.05), while there was statistically significant difference in ECD at 1 day, 1 week, 1 month and 3 months after operation in A2 and B2, A3 and B3 groups (all P<0.05). Group B was significantly better than group A. There was no significant difference in coefficient of variation and HEX between the two groups at different time after surgery (P>0.05). Conclusion: Femtosecond laser-assisted phacoemulsification demonstrates benefits in preserving corneal endothelial cells, reducing early postoperative corneal edema, and minimizing corneal injury in type 2 diabetes patients with cataracts of high nuclear hardness.