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Respiratory distress is common in neonates admitted to neonatal intensive care units. Additionally, infectious diseases such as intrauterine infections or vertical transmission are important underlying causes of respiratory failure. However, pathogens often cannot be identified in neonates, and there are many cases in which antibacterial drugs are empirically administered. Next-generation sequencing (NGS) is advantageous in that it can detect trace amounts of bacteria that cannot be detected by culturing or bacteria that are difficult to cultivate. However, there are few reports on the diagnosis of infectious diseases using NGS in the neonatal field, especially those targeting respiratory distress. The purpose of our study was to investigate the microorganisms associated with neonatal respiratory distress and to determine whether less invasive collection specimens such as plasma and gastric fluid are useful. Neonates were prospectively recruited between January and August 2020 from Nagoya University Hospital. The inclusion criteria were as follows: 1) admission to the neonatal intensive care unit; 2) respiratory distress presentation within 48 h of birth; and 3) suspected infection, collection of blood culture, and administration of antibiotics. Plasma samples and blood cultures were simultaneously collected. Gastric fluid samples were also collected if the patient was not started on enteral nutrition. Information on the patients and their mothers were collected from the medical records. DNA was extracted from 140 µL of plasma and gastric fluid samples. DNA sequencing libraries were prepared, and their quality was analyzed. DNA libraries were sequenced using high-throughput NGS. The NGS data of plasma and gastric fluid samples were analyzed using the metagenomic pipeline PATHDET, which calculated the number of reads assigned to microorganisms and their relative abundance. Putative pathogens were listed. Overall, 30 plasma samples and 25 gastric fluid samples from 30 neonates were analyzed. Microorganism-derived reads of gastric fluid samples were significantly higher than those of plasma samples. Transient tachypnea of the newborn was the most common cause of respiratory distress with 13 cases (43%), followed by respiratory distress syndrome with 7 cases (23%). There were 8 cases (29%) of chorioamnionitis and 7 cases (25%) of funisitis pathologically diagnosed. All blood cultures were negative, and only two gastric fluid cultures were positive for group B Streptococcus (Patient 15) and Candida albicans (Patient 24). Putative pathogens that met the positive criteria for PATHET were detected in four gastric fluid samples, one of which was group B Streptococcus from Patient 15. In the gastric fluid sample of Patient 24, Candida albicans were detected by NGS but did not meet the positive criteria for PATHDET. Cluster analysis of the plasma samples divided them into two study groups, and the indicator genera of each cluster (Phormidium or Toxoplasma) are shown in Figure 1. Clinical findings did not show any significant differences between the two groups. Cluster analysis of the gastric fluid samples divided them into three study groups, and the indicator genera of each cluster (Ureaplasma, Nostoc, and Streptococcus) are shown in Figure 2. The incidence rate of chorioamnionitis was significantly higher in Ureaplasma group than in the other two groups. Gastric fluid may be useful for assessing neonatal patients with respiratory distress. To the best of our knowledge, this was the first study to reveal that the presence of Ureaplasma in the gastric fluid of neonates with respiratory distress was associated with chorioamnionitis. The early diagnosis of intra-amniotic infections using gastric fluid and its treatment may change the treatment strategy for neonatal respiratory distress. Screening for Ureaplasma in neonates with respiratory distress may reduce the need for empirical antibiotic administration. Further research is required to confirm these findings. [ABSTRACT FROM AUTHOR]

Cellulose nanofibers (CNFs) are environmental-friendly nanofiller with high strength and lightweight. To improve the impact properties of carbon fiber reinforced plastics (CFRPs), the application of CNF is expected. However, hydrophobic treatment was unavoidable due to its hydrophilicity. In this study, by adopting an aqueous solution of epoxy resin, the CFRP with CNF dispersion layer was fabricated. From the instrumented Charpy test, it was revealed that the waveform of impact force has two peaks, and the second peak was enlarged by the CNF dispersion layer. As a result, Charpy impact value of the CFRP was increased up to 6%. A novel method to enhance the impact properties of carbon fiber reinforced plastic (CFRP) by using cellulose nanofiber (CNF) was developed. By dispersing CNFs in an aqueous epoxy solution, hydrophobic treatment was eliminated. Inserting the CNF dispersion layer increased the Charpy impact value of CFRP up to 6%. [ABSTRACT FROM AUTHOR]

Cellulose nanofibers (CNFs) are environmentally friendly materials with a high specific strength. To enhance the impact properties of the carbon fiber reinforced plastics (CFRPs), a method for inserting a CNF dispersion layer between prepregs was developed. By using an aqueous solution of epoxy resin, the hydrophobic treatment of CNF became unnecessary. In this study, CFRP with CNF dispersion layers was fabricated with different CNF content. The impact energy absorbed by the CFRP specimen was increased with the increasing CNF content, and the Charpy impact value increased up to a maximum of 21% by the CNF dispersion layers. Carbon fiber reinforced plastics (CFRPs) specimens with the cellulose nanofiber (CNF) dispersion layer were fabricated. The specimens were fabricated by varying the content of CNF. Impact energy absorbed by the CFRP specimen was increased with increased CNF content. Charpy impact value increased up to 21%; optimum ductility index value was clarified. [ABSTRACT FROM AUTHOR]

An efficient method to increase specific strength of carbon fiber reinforced plastics (CFRP) by using cellulose nanofibers (CNFs) was developed. Eliminating a complex hydrophobic treatment of CNF by using aqueous electrodeposition solution (EDS) containing a polymer with epoxy group, the CFRP with CNF/resin layer was fabricated. The effects of the CNF/resin layer on the bending properties of CFRP were clarified by varying the weight fractions of CNF. The specific flexural rigidity and strength of the CFRP with CNF/resin layer were increased to approximately 3.5 times and 1.8 times those of the CFRP without CNF/resin layer, respectively. [ABSTRACT FROM AUTHOR]

Cellulose nanofibers (CNFs) are sustainable materials with high specific strengths. To enhance the impact properties of carbon fiber reinforced plastics (CFRPs), the authors have developed an efficient process for incorporating a non-hydrophobized CNF dispersion layer into CFRPs. In this study, the impact properties of CFRP with asymmetrically stacked CNF dispersion layer was investigated by conducting the instrumented Charpy impact tests. Two types of CNFs were used for comparison. Consequently, by inserting the CNF dispersion layer into the opposite side of the striking surface, the Charpy impact value increased by 26% compared to CFRP without CNF dispersion layer. [ABSTRACT FROM AUTHOR]

Cellulose nanofibers (CNFs) are a plant-derived material with a high specific strength. The authors have developed a method to enhance the impact properties of carbon fiber reinforced plastics (CFRP) by inserting a non-hydrophobic CNF dispersion layer between prepregs. In this study, the specimens with different stacking sequence of the prepreg and CNF dispersion layer were manufactured, and the instrumented Charpy test was carried out. Analyzing the impact waveform, when the CNF dispersion layer was inserted below the surface prepreg, the Charpy impact value was increased by up to 6% compared to the CFRP without the CNF dispersion layer. [ABSTRACT FROM AUTHOR]