RESUMEN
In this paper, an anisotropic magnetoresistive (AMR) thin film sensor which can be used for magnetic scale has been prepared, and its output voltage is about 4.7-4.9 mV V-1. On the basis of the Stoner-Wohlfarth model and with considering the non-uniformity of the demagnetizing field along the width direction of the strips, both the static and dynamic responses of the AMR sensors have been calculated. The results have shown that the calculated results are in agreement with the experimental data. The magnetization rotation in the magnetic sensor strongly depends on the nonuniform demagnetizing field along the width direction. The magnetization at the center is easily rotated into the field direction, and the magnetization at the edge is difficult to be rotated. The smaller the width of the magnetoresistive strip is, the larger both the demagnetizing field at the edge and the saturation field of the magnetic sensor are. The results are helpful for understanding the magnetization rotation of magnetic sensors and developing the magnetic sensors with high performance.
RESUMEN
OBJECTIVE: To evaluate the association of mode of delivery (MOD) with short-term and neurodevelopmental outcomes at 2 years of corrected age (CA) in periviable singleton infants. METHODS: This retrospective cohort study of the Taiwan Premature Infant Follow-up Network database between 2010 and 2016 compared non-anomalous singleton deliveries (cesarean delivery [CD] vs vaginal delivery [VD]) between 22 0/7 and 25 6/7 gestational weeks. Major morbidities, mortality, and neurodevelopmental outcomes were evaluated at 2-year CA. RESULTS: The CD and VD groups included 354 and 472 infants, respectively. The intraventricular hemorrhage (IVH) rate was lower in the CD group (54% vs 66%, P = 0.001), but severe IVH differed non-significantly between groups (20% vs 26%, P = 0.057). In the small-for-gestational age subgroup, CD was associated with lower IVH (56% vs 84%, adjusted odds ratio [aOR] 0.17, 95% confidence interval [CI] 0.04-0.69) and better survival without neurodevelopmental impairment (29% vs 8%, aOR, 6.64, 95% CI 1.02-43.29) after controlling for potential confounders. CONCLUSION: The optimal MOD for periviable singleton birth and its impact are unclear. CD in periviable singleton births is associated with a decreased IVH risk, without improvement in severe IVH, mortality, or neurodevelopment at 2-year CA. The small-for-gestational age subgroup may benefit from CD for better survival without neurodevelopmental impairment.