for the Nasal Oscillation Post-Extubation (NASONE) Study Group IMPORTANCE Several respiratory support techniques are available to minimize the use of invasive mechanical ventilation (IMV) in preterm neonates. It is unknown whether noninvasive high-frequency oscillatory ventilation (NHFOV) is more efficacious than nasal continuous positive airway pressure (NCPAP) or nasal intermittent positive pressure ventilation (NIPPV) in preterm neonates after their first extubation.OBJECTIVE To test the hypothesis that NHFOV is more efficacious than NCPAP or NIPPV in reducing IMV after extubation and until neonatal intensive care unit discharge among preterm neonates. DESIGN, SETTING, AND PARTICIPANTSThis multicenter, pathophysiology-based, assessor-blinded, 3-group, randomized clinical trial was conducted in 69 tertiary referral neonatal intensive care units in China, recruiting participants from December 1, 2017, to May 31, 2021. Preterm neonates who were between the gestational age of 25 weeks plus 0 days and 32 weeks plus 6 days and were ready to be extubated were randomized to receive NCPAP, NIPPV or NHFOV. Data were analyzed on an intention-to-treat basis. INTERVENTIONSThe NCPAP, NIPPV, or NHFOV treatment was initiated after the first extubation and lasted until discharge.MAIN OUTCOMES AND MEASURES Primary outcomes were total duration of IMV, need for reintubation, and ventilator-free days. These outcomes were chosen to describe the effect of noninvasive ventilation strategy on the general need for IMV.RESULTS A total of 1440 neonates (mean [SD] age at birth, 29.4 [1.8] weeks; 860 boys [59.7%]) were included in the trial. Duration of IMV was longer in NIPPV (mean difference, 1.2; 95% CI, 0.01-2.3 days; P = .04) and NCPAP (mean difference, 1.5 days; 95% CI, 0.3-2.7 days; P = .01) compared with NHFOV. Neonates who were treated with NCPAP needed reintubations more often than those who were treated with NIPPV (risk difference: 8.1%; 95% CI, 2.9%-13.3%; P = .003) and NHFOV (risk difference, 12.5%; 95% CI, 7.5%-17.4%; P < .001). There were fewer ventilator-free days in neonates treated with NCPAP than in those treated with NIPPV (median [25th-75th percentile] difference, −3 [−6 to −1] days; P = .01). There were no differences between secondary efficacy or safety outcomes, except for the use of postnatal corticosteroids (lower in NHFOV than in NCPAP group; risk difference, 7.3%; 95% CI, 2.6%-12%; P = .002), weekly weight gain (higher in NHFOV than in NCPAP group; mean difference, −0.9 g/d; 95% CI, −1.8 to 0 g/d; P = .04), and duration of study intervention (shorter in NHFOV than in NIPPV group; median [25th-75th percentile] difference, −1 [−3 to 0] days; P = .01).CONCLUSIONS AND RELEVANCE Results of this trial indicated that NHFOV, if used after extubation and until discharge, slightly reduced the duration of IMV in preterm neonates, and both NHFOV and NIPPV resulted in a lower risk of reintubation than NCPAP. All 3 respiratory support techniques were equally safe for this patient population.

In the present study, factors that related to neonatal IVH included hypotension, prenatal steroid use, and transportation.

Revealing the characteristics of spatial–temporal dynamics and influencing factors is important for optimizing the spatial distribution of tea production. Taking prefecture-level cities as the basic spatial unit, this study uses the Herfindahl index and exploratory spatial data analysis to reveal the spatial–temporal dynamics of China’s tea production from 2000 to 2015. A theoretical analysis framework is established and a spatial econometric model is used to explore its influencing factors. The results show a U-shaped trend in the degree of tea spatial agglomeration, which gradually declined during 2000–2010, and rapidly increased during 2011–2015. The proportion of tea production shifted from the eastern region to the central and western regions, and spatial distribution coverage expanded to the north. Tea production had significant spatial correlation, and spatial agglomeration characteristics were exhibited for similar values (high or low). Tea production had a significant spatial spillover effect. Natural resources, labor cost, specialized production, and policies all affected the spatial–temporal dynamics of tea production somewhat, but the effects of traffic conditions and technological level were insignificant. Finally, this study proposed optimizing four aspects of the tea spatial layout: regional cooperation, comprehensive suitability evaluation of tea cultivation, spatial agglomeration, and distinctive local brands.