Impact factors and obstetric outcomes of preeclampsia in twin pregnancies by prepregnancy body mass index: a six-year retrospective cohort study.

OBJECTIVES: Among many risk factors for preeclampsia (PE), prepregnancy body mass index (BMI) is one of few controllable factors. However, there is a lack of stratified analysis based on the prepregnancy BMI. This study aimed to determine the influencing factors for PE and assess the impact of PE on obstetric outcomes in twin pregnancies by prepregnancy BMI. METHODS: This was a retrospective cohort study between January 1, 2017, and December 31, 2022, in Southwest China. Impact factors and associations between PE and obstetric outcomes were analyzed separately for twin pregnancies with prepregnancy BMI < 24kg/m2 (non-overweight group) and BMI ≥ 24kg/m2 (overweight group). RESULTS: In total, 3602 twin pregnancies were included, of which, 672 women were allocated into the overweight group and 11.8% of them reported with PE; 2930 women were allocated into the non-overweight group, with a PE incidence of 5.6%. PE had a negative effect on birthweight and increased the incidence of neonatal intensive care unit admission in both the overweight and non-overweight groups (43.0% vs. 28.0%, p = .008; 45.7% vs. 29.1%, p < .001). Among overweight women, PE increased the proportion of postpartum hemorrhage (15.2% vs. 4.4%, p < .001). After adjustments, multivariate regression analysis showed that excessive gestational weight gain (aOR = 1.103, 95% CI: 1.056-1.152; aOR = 1.094, 95% CI: 1.064-1.126) and hypoproteinemia (aOR = 2.828, 95% CI: 1.501-5.330; aOR = 6.932, 95% CI: 4.819-9.971) were the shared risk factors for PE in both overweight and non-overweight groups. In overweight group, in vitro fertilization was the other risk factor (aOR = 2.713, 95% CI: 1.183-6.878), whereas dichorionic fertilization (aOR = 0.435, 95% CI: 0.193-0.976) and aspirin use during pregnancy (aOR = 0.456, 95% CI: 0.246-0.844) were protective factors. Additionally, anemia during pregnancy (aOR = 1.542, 95% CI: 1.090-2.180) and growth discordance in twins (aOR = 2.451, 95% CI: 1.215-4.205) were connected with an increased risk of PE only in non-overweight twin pregnancies. CONCLUSIONS: Both discrepancy and similarity of impact factors on developing PE were found between overweight and non-overweight twin pregnancies in this study. However, the dosage and initiation time of aspirin, as well as twin chorionicity on the occurrence of PE in two subgroups, are still debated.

Flexural Properties and Failure Mechanisms of Short-Carbon-Fiber-Reinforced Polylactic Acid Composite Modified with MXene and GO.

Recently, short-fiber-reinforced thermoplastic composites (SFRTPCs) have been playing a more and more crucial role in the application of automotive interior materials due to their advantages of low density and environmental resistance properties. However, their relevant mechanical properties need to be optimized. Previous investigations revealed that the surface modification of fibers is useful to improve their mechanical properties. In this work, carbon fiber (CF)-reinforced polylactic acid (PLA) composites modified with MXene and graphene oxide (GO) were prepared by twin-screw extrusion and injection molding methods. Short CF was firstly modified with polyetherimide (PEI), then different weight ratios of MXene-GO (1:1) were subsequently modified on PEI-CF. Finally, the flexural properties and failure mechanisms were analyzed. The results showed that MXene-GO was successfully coated on CF surface, and the flexural strength and modulus of CF-PEI-MXene-GO-reinforced PLA (CF-PEI-MG/PLA) composite were improved compared to that of CF/PLA composite. In addition, the fracture sections of the composites were flat and white, and the fibers bonded well with PLA for CF-PEI-0.1MG/PLA composite compared to CF/PLA composite. The present study could provide a reference for further improving the mechanical performance of PLA-related composites.

High Temperature Mechanical Response and Failure Analysis of 3D Five-Directional Braided Composites with Different Braiding Angles.

Three-dimensional (3D) five-directional braided composites are extensively applied in aeronautics and national defense due to their integrity and structural superiorities. In this paper, 3D five-directional braided carbon/epoxy composites were manufactured, and the high temperature mechanical response and failure mechanisms of composites with braiding angles of 21° and 32° were studied. The out-of-plane compression tests of composites with different braiding angles were conducted at temperatures ranging from 25 °C to 180 °C. Then compression stress-strain curves, compression mechanical response, and failure modes of composites at high temperatures were analyzed and compared. The results show that compression stress-strain curves linearly increased at the initial stage and dropped at various degrees at different temperatures for composites with different braiding angles. The temperature and braiding angle were both important parameters affecting out-of-plane compression properties of 3D five-directional braided composites. Mechanical properties decreased with increasing temperature for both 21° and 32° specimens. Moreover, composites with a small braiding angle possessed higher properties at each temperature point. The morphologies manifested that the failures were a symmetric ±45° shear crack for 21° specimens and a thorough 45° shear crack for 32° specimens, and a 45° fracture weakened with increasing temperature.

New precut sphincterotomy for endoscopic retrograde cholangiopancreatography in difficult biliary duct cannulation.

AIM: To retrospectively investigate the effect and safety of various new type precut sphincterotomy techniques (VNTPST) in endoscopic retrograde cholangiopancreato-graphy (ERCP) due to difficult biliary duct cannulation (DBC). METHODS: A plough-like pull-type sphincterotome (PLPTS) or improved short nose sphincterotome or improved needle knife was applied. VNTPST was carried out in 30 of 280 patients, whose biliary tract could not be exposed well or deep cannulation was difficult to perform during ERCP with traditional methods. Patients were followed up for short-term complications and the therapeutic effect of VNTPS was observed and compared with that of traditional endoscopic sphincterotomy (EST). RESULTS: A total 280 patients underwent ERCP, of which 3 failed in operation because of pathological features in stomch or duodenum, 247 successfully underwent traditional ERCP (89.1%, 247/277), 30 failed (10.8%, 30/277). VNTPS technique succeeded in 24 (80%, 24/30) of 30 cases. The successful rate of deep biliary duct cannulation increased 8.6% (24/277), the total cannulation successful rate following precut was 97.7%. There was a significant difference between the two groups (97.7% vs 89.1%, c2 = 17.1, P < 0.01). The incidence of complications was 9.3% (26/277) for traditional ERCP group and 13.3% (4/30) for VNTPS technique group. Guideline tip was broken in pancreatic duct (KPDGP) of one patient, and there was no pancreatitis, slight or moderate bleeding postoperatively occurred in 2 patients, 1 patient had bleeding during operation (PDWN). There were no differences between VNTPS technique group and traditional ERCP (TRERCP) group (13.3% vs 9.3%, c2 = 0.478, P > 0.05). CONCLUSION: VNTPS procedure and Deng's precut are highly effective methods to get biliary access during ERCP with DBC. With skillful techniques, it can increase the successful rate for deep cannulation of biliary duct and decrease complications. VNTPS technique, especially Deng's precut is as effective and safe as EST. This technique can be well performed in hospitals without particular equipments.