4 research outputs found
The Impacts of Single Preterm Human Donor Milk Compared to Mother’s Own Milk on Growth and Body Composition
(1) If mother´s own milk (MOM) is not available, pooled term human donor milk (HDM) is commonly used. Compared to MOM, term HDM contains less protein and fat and is associated with impaired growth. HDM from mothers of preterm infants is an alternative source and contains higher protein levels compared to term HDM, but the impacts on growth and body composition are unclear. (2) Methods: Infants born below 32 weeks of gestation and below 1500 g between 2017–2022, who underwent air displacement plethysmography (Pea Pod®) to determine body composition (FFM: fat-free mass; FM: fat mass) at term-equivalent age, were included. A comparison between infants fed with MOM > 50% (MOM-group) and single preterm HDM > 50% (HDM-group) was conducted. (3) Results: In total, 351 infants (MOM-group: n = 206; HDM-group: n = 145) were included for the analysis. The median FFM-Z-score (MOM-group: −1.09; IQR: −2.02, 1.11; HDM-group: −1.13; IQR: −2.03, 1.12; p = 0.96), FM-Z-score (MOM-group: 1.06; IQR: −0.08, 2.22; HDM-group: 1.19; IQR: −0.14, 2.20; p = 0.09), and median growth velocity (MOM-group: 23.1 g/kg/d; IQR: 20.7, 26.0; HDM: 22.5 g/kg/d; IQR: 19.7, 25.8; p = 0.15) values were not significantly different between the groups. (4) Conclusion: Single preterm HDM is a good alternative to support normal growth and body composition
The Effect of Acceptor and Donor Doping on Oxygen Vacancy Concentrations in Lead Zirconate Titanate (PZT)
The different properties of acceptor-doped (hard) and donor-doped (soft) lead zirconate titanate (PZT) ceramics are often attributed to different amounts of oxygen vacancies introduced by the dopant. Acceptor doping is believed to cause high oxygen vacancy concentrations, while donors are expected to strongly suppress their amount. In this study, La3+ donor-doped, Fe3+ acceptor-doped and La3+/Fe3+-co-doped PZT samples were investigated by oxygen tracer exchange and electrochemical impedance spectroscopy in order to analyse the effect of doping on oxygen vacancy concentrations. Relative changes in the tracer diffusion coefficients for different doping and quantitative relations between defect concentrations allowed estimates of oxygen vacancy concentrations. Donor doping does not completely suppress the formation of oxygen vacancies; rather, it concentrates them in the grain boundary region. Acceptor doping enhances the amount of oxygen vacancies but estimates suggest that bulk concentrations are still in the ppm range, even for 1% acceptor doping. Trapped holes might thus considerably contribute to the charge balancing of the acceptor dopants. This could also be of relevance in understanding the properties of hard and soft PZT