Investigation of extrauterine growth restriction in very preterm infants in Chinese neonatal intensive care units / 中华儿科杂志

Objective: To comprehensively assess the current status of extrauterine growth restriction (EUGR) in very preterm infants (VPI) and its associated factors in Chinese neonatal intensive care units (NICU). Methods: In this cohort study, 6 179 preterm infants born at <32 weeks' gestation were included, who were admitted to 57 hospitals in the China Neonatal Network in 2019 and hospitalized for ≥7 days. EUGR was evaluated by a cross-sectional definition (weight at discharge<10th percentile for postmenstrual age), a longitudinal definition (decline in weight Z score>1 from birth to discharge), and weight growth velocity. The comparison between infants with and without EUGR was conducted by t-test, Mann-Whitney U test or χ2 test as appropriate. Multivariable Logistic regression models were used to evaluate associations between EUGR with different definitions and maternal and neonatal factors, clinical practices, and neonatal morbidities. Results: A total of 6 179 VPI were enrolled in the study, with a gestational age of (29.8±1.5) weeks and birth weight of (1 365±304) g; 56.2% (3 474) of them were male. Among them, 48.4% (2 992 VPI) were cross-sectional EUGR and 74.9% (4 628 VPI) were longitudinal EUGR. Z score of weight was (0.13±0.78) at birth and decrease to (-1.35±0.99) at discharge. The weight growth velocity was 10.13 (8.42, 11.66) g/(kg·d). Multivariate Logistic regression analysis showed that among the influential factors that could be intervened after birth, late attainment of full enteral feeds (ORadjust=1.01, 95%CI 1.01-1.02, P<0.001; ORadjust=1.01, 95%CI 1.01-1.02, P<0.001), necrotizing enterocolitis≥Ⅱstage (ORadjust=2.64, 95%CI 1.60-4.35, P<0.001; ORadjust=1.62, 95%CI 1.10-2.40, P<0.001) and patent ductus arteriosus (ORadjust=1.94, 95%CI 1.50-2.51, P<0.001; ORadjust=1.63, 95%CI 1.29-2.06, P<0.001) were all associated with increased risks of both cross-sectional and longitudinal EUGR. In addition, late initiation of enteral feeds (ORadjust=1.06, 95%CI 1.02-1.09, P=0.020) and respiratory distress syndrome (ORadjust=1.45, 95%CI 1.24-1.69, P<0.001) were all associated with cross-sectional EUGR. Breast milk feeding (ORadjust=1.33, 95%CI 1.05-1.68, P<0.001) was associated with a higher risk of longitudinal EUGR. Conclusions: The incidence of EUGR in VPI in China is high. Some modifiable risk factors provide priorities to improve postnatal growth for VPI. Nutritional management of VPI and the efforts to decrease the incidence of complications are still the focus of clinical management in China.

Application of 18S rDNA Clone Library to Detect Diatom Population Diversity in Dianchi / 法医学杂志

Objective To detect the diatom population diversity in Dianchi by constructing a 18S rDNA clone library. Methods DNA from diatoms in 6 water samples of Dianchi was amplified with diatom 18S rDNA specific primer.The 18S rDNA clone library was constructed, and clones were randomly selected for sequence. Sequence alignment was performed by BLAST. The diatom population distribution in Dianchi was analyzed and the phylogenetic tree of diatom 18S rDNA in Dianchi waters was established with the MEGA v7.0.14 software. Results Two hundred and forty clones were sequenced, with 167 diatom sequences obtained, including 11 diatom species such as Stephanodiscus, Diatoma, and Melosira. There were certain differences in diatom population distribution among the 6 samples. Conclusion The population distribution of diatom species in Dianchi shows unique features and the sequence analysis of diatom 18S rDNA has a certain reference value to the inference of forensic drowning sites.

The mechanism and efficiency affecting factor of cationic liposome transfection / 生物工程学报

Cationic liposome is a greatly promising gene carrier. In this paper, the structure trait of cationic liposome was briefly introduced, the mechanism of cationic liposomes mediated gene delivery and the main influencing factor of transfection efficiency in the transfection process were discussed chiefly.