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Preliminary evidence from China and other countries has suggested that coronavirus disease 2019 (COVID-19) mitigation measures have caused a decline in preterm births, but evidence is conflicting. Utilising a national representative data of 11,714,947 pregnant women in China, we explored the immediate changes in preterm birth rates during the COVID-19 mitigation period using an interrupted-time-series analysis. We defined the period prior to February 1, 2020 as the baseline, followed by the COVID-19 mitigation stage. In the first month of the COVID-19 mitigation, a significant absolute decrease in preterm birth rates of 0.68% (95%CI:−1.10% to −0.26%) in singleton, and of 2.80% (95%CI:−4.51% to −1.09%) in multiple births was noted. This immediate decline in Wuhan was greater than that at the national level among singleton births [−2.21% (95%CI:−4.09% to −0.34% vs. −0.68%)]. Here we report an immediate impact of COVID-19 mitigation measures on preterm birth in China. The broader impacts of COVID-19 mitigation measures may include changes in the incidence of preterm birth. Here, the authors use data from ~11.7 million pregnancies in China and find evidence of a small decline in preterm birth rates immediately following the implementation of COVID-19 mitigation measures. [ABSTRACT FROM AUTHOR]

We aimed to describe the characteristics of adolescent pregnancy, determine its effect on adverse maternal and perinatal outcomes and explore whether that association varies with gestational age with the goal of proposing specific recommendations for adolescent health in China. This study included 2,366,559 women aged 10–24 years who had singleton pregnancies between 2012 and 2019 at 438 hospitals. Adolescent pregnancy was defined as younger than 20 years of age. We used multivariable logistic regression to estimate the effects. Women aged 20–24 years served as the reference group in all analyses. The proportion of rural girls with adolescent pregnancies rebounded after 2015 even though common-law marriage in rural areas decreased. Higher risks of eclampsia (adjusted odds ratio (aOR) 1.87, 95% confidence interval (CI) 1.57 ~ 2.23), severe anaemia (aOR 1.18, 95% CI 1.09 ~ 1.28), maternal near miss (MNM; aOR 1.24, 95% CI 1.12 ~ 1.37), and small for gestational age (SGA; aOR 1.30, 95% CI 1.28 ~ 1.33) were observed when gestational age was > 37 weeks. Adolescent pregnancy was independently associated with increased risks of other perinatal outcomes. Further implementation of pregnancy prevention strategies and improved health care interventions are needed to reduce adolescent pregnancies and prevent adverse fertility outcomes among adolescent women in China at a time when adolescent fertility rate is rebounding. [ABSTRACT FROM AUTHOR]

Polyethylene/Polypropylene (PE/PP) composite non-woven fabrics have been used widely for surgical packages due to its dual features of PE surface and PP surfaces. PP fabric pre-treated by hydrophilic agent provides high water absorbency, while PE surface is responsible for high barrier functions. However, the PP water absorbency declines once PE film is laminated, and no report devoted to study the extent and the reasons of this declining. Herein, the hydrophilic finishing of the PP non-woven fabrics was processed via Kiss-roll method, then the PE/PP fabrics were obtained using a normal hot melt adhesive PE film laminating process. The wicking height, water absorption specific gravity (LAC%), static contact angle, as well as the complete wetting time of the finished PP and PE/PP fabric were measured and compared. Meanwhile, the SEM was used to detect the morphology changing. The results revealed that the pores between fibers in the PP non-woven were filled with non-hydrophilic hot melt adhesive penetrated during PE lamination, so that the PP structure changed to be less porous. Moreover, the laminated PP layer actually blocks the water flow channel in the system, resulting in the absorbency reduction after lamination. As a result, comparing with the PP non-woven fabric, the wicking height of the PE/PP fabric decreased by 25.3 %, the LAC % value reduced by 40.83 %, and the complete wetting time extended from 0.29 s to 1.74 s. [ABSTRACT FROM AUTHOR]

The majority of the accreting supermassive black holes in the Universe are obscured by large columns of gas and dust. The location and evolution of this obscuring material have been the subject of intense research in the past decades, and are still debated. A decrease in the covering factor of the circumnuclear material with increasing accretion rates has been found by studies across the electromagnetic spectrum. The origin of this trend may be driven by the increase in the inner radius of the obscuring material with incident luminosity, which arises from the sublimation of dust; by the gravitational potential of the black hole; by radiative feedback; or by the interplay between outflows and inflows. However, the lack of a large, unbiased and complete sample of accreting black holes, with reliable information on gas column density, luminosity and mass, has left the main physical mechanism that regulates obscuration unclear. Here we report a systematic multi-wavelength survey of hard-X-ray-selected black holes that reveals that radiative feedback on dusty gas is the main physical mechanism that regulates the distribution of the circumnuclear material. Our results imply that the bulk of the obscuring dust and gas is located within a few to tens of parsecs of the accreting supermassive black hole (within the sphere of influence of the black hole), and that it can be swept away even at low radiative output rates. The main physical driver of the differences between obscured and unobscured accreting black holes is therefore their mass-normalized accretion rate. [ABSTRACT FROM AUTHOR]