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Objective The study aimed to evaluate the association between bronchopulmonary dysplasia (BPD) development at 36 weeks' postmenstrual age (PMA) and Gram-negative bacteria in tracheal aspirate cultures among extremely preterm infants. Study Design This study has a retrospective cohort. Patients were 155 infants aged less than or equal to 26 gestational weeks who were admitted to the neonatal intensive care unit of Osaka Women's and Children's Hospital from 2009 to 2018. Primary outcome was respiratory outcomes expressed as BPD development. Multivariable logistic regression analysis was used to identify neonatal and bacterial factors associated with BPD. Results After adjusting for gestational age, birth weight, sex, chorioamnionitis, Gram-positive cocci (GPC) and Gram-negative rods (GNRs) in tracheal aspirate cultures within 28 days after birth, GNRs were significantly associated with BPD development (odds ratio [OR]: 3.88, 95% confidence interval [CI]: 1.68–8.94). In contrast, GPCs were not associated with BPD development (OR: 0.47, 95% CI: 0.05–1.61). Conclusion Gram-negative bacteria in tracheal cultures within 28 days of birth are associated with BPD development in infants aged less than or equal to 26 gestational weeks. Key Points BPD is a factor for morbidity in extremely preterm infants. Respiratory infection is an adverse outcome of BPD. GNRs in tracheal cultures soon after birth disturb BPD development. GPC was not associated with BPD development. [ABSTRACT FROM AUTHOR]

Optical transition properties of nanocrystalline silicon (nc-Si) doped Si[O.sub.2] thin films prepared by cosputtering with Si[O.sub.2] target and Si-chips followed by high temperature annealing were investigated as a function of ratio of target area (Si/Si[O.sub.2]) in the range of 0 to 0.19. Optical transmission measurements revealed that the indirect band-gap of nc-Si decreased from 4.87 to 2.32 eV with increasing Si/Si[O.sub.2] from 0.04 to 0.19, whereas no noticeable absorption was observed for the samples with Si/Si[O.sub.2] = 0.00. Photoluminescence (PL) measurements showed that considerably weak emissions due to oxygen deficient center (ODC) in Si[O.sub.2] films were observed at 514-539 nm for samples with lower Si/Si[O.sub.2] of 0.0-0.09, while the strong emissions due to an interfacial layer between the nc-Si core and the Si[O.sub.2] surface layer were observed at 746-808 nm for samples with higher Si/Si[O.sub.2] of 0.13-0.19. PL excitation spectrum monitored at 800 nm showed that the PL at 800 nm was excited through nc-Si. On the other hand, cathodoluminesncence peaks were observed at 455 and 465 nm for the samples with 0.04 and 0.13, respectively, in which both peaks were assigned to originate from oxygen vacancies created during electron beam irradiation. The mechanisms of three types of luminescence, due to the ODC in Si[O.sub.2] band-to-band transition of nc-Si, and the interfacial layer between the nc-Si core and the Si[O.sub.2] surface layer, are discussed. PACS Nos.: 78.67.Bf, 78.55.Hx, 81.15.Cd. Nous analysons, en fonction d'un rapport de surface de cible (Si/Si[O.sub.2]) variant de 0 a 0,19, les proprietes des transitions optiques de films minces de Si[O.sub.2] dopes au silicium nanocristallin, nc-Si, prepares par une co-pulverisation avec des cibles de Si[O.sub.2] et des puces de Si, suivie d'un recuit a haute temperature. Les mesures de transmission optique revelent que la bande interdite indirecte du nc-Si decroit de 4,87 a 2,32 eV lorsque Si/Si[O.sub.2] augmente de 0,04 a 0,19, alors qu'on n'observe aucune absorption pour les echantillons avec Si/Si[O.sub.2] = 0,0. Des mesures de photoluminescence (PL) montrent qu'une tres faible emission due au centre deficient en oxygene (ODC) dans les films de Si[O.sub.2] est observee a 514-539 nm pour les echantillons avec Si/Si[O.sub.2] = 0,0-0,09, alors qu'une forte emission due a une couche inter-faciale entre le coeur de nc-Si et la couche de surface de Si[O.sub.2] est observee a 706-808 nm pour des echantillons avec Si/Si[O.sub.2] = 0,13-0,19. Le spectre d'excitation de PL observe a 800 nm montre que le PL a 800 nm est excite par le nc-Si. D'autre part, les pics de cathodoluminescence sont observes a 455 et 465 nm pour les echantillons avec 0,04 et 0,13 respectivement, dans lesquels les deux pics proviennent de lacunes en oxygene crees pendant l'irradiation par faisceau d'electrons. Nous discutons des trois mecanismes de luminescence, due aux ODC dans le Si[O.sub.2], aux transitions bande-a-bande du nc-Si et a la couche interfaciale entre le coeur de nc-Si et la couche de surface de Si[O.sub.2]. [Traduit par la Redaction], 1. Introduction Multifunctional electronic devices are attractive for the realization of optoelectronic integrated circuits because one electronic device has many functions (e.g., light emitting device and flash memory), which can [...]

Aim: To evaluate the pregnancy outcomes of preterm premature rupture of membranes (preterm PROM; PPROM) by gestational age. Methods: This cohort study analyzed data from the Japan Environment and Children's Study. Pregnancy outcomes were documented using descriptive statistics. Logistic regression was used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) of complications. Results: Data were collected for 104 062 fetuses, and 99 776 were eligible for inclusion. The incidences of early (18–23 weeks) and late (24–36 weeks) PPROM were 0.1% (n = 102) and 1.2% (n = 1205), respectively. Of the 1307 cases, 66 (5.0%) resulted in miscarriage or stillbirth. Overall, 85.6% (1119/1307) resulted in preterm births, and 9.3% (122/1307) in term births. There was a higher incidence of oligohydramnios (OR 6.82, 95% CI 4.07, 11.4; OR 2.42, 95% CI 1.72, 3.40), intrauterine infection (OR 11.9, 95% CI 7.06, 19.9; OR 4.39, 95% CI 3.01, 6.41), cesarean delivery (OR 3.31, 95% CI 2.32, 4.71; OR 1.34, 95% CI 0.97, 1.85), placental abruption (OR 5.57, 95% CI 2.30, 13.5; OR 5.40, 95% CI 3.58, 8.14), and 5‐min Apgar score <7 (OR 35.3, 95% CI 21.5, 57.9; OR 2.66, 95% CI 1.75, 4.05) for early and late, compared to no, PPROM, respectively. Miscarriage or stillbirth was higher in early (OR 5.84, 95% CI 3.72, 9.15) and lower in late (OR 0.21, 95% CI 0.06, 0.68) compared to those without PPROM. Conclusions: This study described the epidemiology of pregnancy outcomes of early (occurring at the limit of viability) and late PPROM. [ABSTRACT FROM AUTHOR]