No abstract

To assess the amino acid and fatty acid metabolite patterns between infants with and without bronchopulmonary dysplasia in different nutritional stages after birth and identify metabolic indicators of bronchopulmonary dysplasia. This was an observational cohort of preterm infants born at a gestational age ≤32 + 6 weeks and with a body weight ≤2000 g. Amino acid and carnitine profiles were measured in dried blood spots (DBSs) during the early nutrition transitional phase using tandem mass spectrometry. Bronchopulmonary dysplasia was defined as oxygen dependence at 36 weeks of postmenstrual age or 28 days after birth. Metabolomic analysis was employed to define metabolites with significant differences, map significant metabolites into pathways, and identify metabolic indicators of bronchopulmonary dysplasia. We evaluated 45 neonates with and 40 without bronchopulmonary dysplasia. Four amino acids and three carnitines showed differences between the groups. Three carnitines (C0, C2, and C6:1) were high in the bronchopulmonary dysplasia group mostly; conversely, all four amino acids (threonine, arginine, methionine, and glutamine (Gln)) were low in the bronchopulmonary dysplasia group. Pathway analysis of these metabolites revealed two pathways with significant changes (p < 0.05). ROC analysis showed Gln/C6:1 at total parenteral nutrition phase had both 80% sensitivity and specificity for predicting the development of bronchopulmonary dysplasia, with an area under the curve of 0.81 (95% confidence interval 0.71–0.89). Amino acid and fatty acid metabolite profiles changed in infants with bronchopulmonary dysplasia after birth during the nutrition transitional period, suggesting that metabolic dysregulation may participate in the development of bronchopulmonary dysplasia. Our findings demonstrate that metabolic indicators are promising for forecasting the occurrence of bronchopulmonary dysplasia among preterm neonates.

With appearance of variety kinds of three-dimension buoy application system, the design and production of three-dimension virtual model of buoy is increasingly becoming an important and tedious work. Artificial modeling way adopted in the past is inefficient, and the light quality is difficult to achieve. The paper puts forward automatically generating method for three-dimension virtual model of buoy based on S-57 chart data (AGM for short), and describes extraction and analysis of buoy data from S-57 chart data, automatically generation of three-dimension buoy model and the flashing animation of buoy light quality in detail, and finally gives the experimental data and results.

Researchers have recently attempted to discover alternative energy sources that are accessible, technically viable, economically feasible, and environmentally acceptable. The objective of this study is to investigate regulated and unregulated exhaust emissions with petroleum diesel fuel and Jatrophabased biodiesel blends at proportions of 20%, 40%, 60%, 80% and 100% (v/v). This study examines three regulated emissions: CO, NMHC and NOx, and two typical unregulated emissions: SO2 and formaldehyde. The CO and formaldehyde emissions increase at low engine loads, and decrease at high engine loads. The NMHC and NOx emissions of the five fuels continuously decrease as biodiesel blends increase. Besides, SME fuels can also reduce the SO2 emissions.