Challenges and improvement in management of neonates born to mothers with COVID-19 in China

Objective:China was the first country suffering from the SARS-CoV-2 pandemic and one of the countries with stringent mother-neonate isolation measure implemented.Now increasing evidence suggests that coronavirus disease 2019(COVID-19)should not be taken as an indication for formula feeding or isolation of the infant from the mother.Methods:We conducted a retrospective cohort study in 44 hospitals from 14 provinces in China to investigate the management of neonates whose mothers have confirmed or suspected COVID-19.In addition,65 members of Chinese Neonatologist Association(CNA)were invited to give their comments and suggestions on the clinical management guidelines for high-risk neonates.Results:There were 121 neonates born to 118 mothers suspected with COVID-19 including 42 mothers with SARS-CoV-2 positive results and 76 mothers with SARS-CoV-2 negative results.All neonates were born by caesarean section,isolated from their mothers immediately after birth and were formula-fed.Five neonates were positive for SARSCoV-2 at initial testing between 36 and 46 h after birth.Regarding the confusion on the clinical management guidelines,58.78%of the newborns were put into isolation,32.22%were subject to PCR tests,and 5.16%and 2.75%received breastfeeding and vaccination,respectively.Conclusion:The clinical symptoms of neonates born to mothers with confirmed SARS-CoV-2 were mild,though five neonates might have been infected in utero or during delivery.Given the favorable outcomes of neonates born to COVID-confirmed mothers,full isolation may not be warranted.Rather,separation of the mother and her newborn should be assessed on a case-by-case basis,considering local facilities and risk factors for adverse outcomes,such as prematurity and fetal distress.

Macroporous 3D carbon-nitrogen(CN)confined MoO_(x) catalyst for enhanced oxidative desulfurization of dibenzothiophene

Macroporous 3D carbon doped with nitrogen confined Mo catalyst(MoO_(x)@CN)had been prepared by a facile one-step pyrolysis technique using silica as a template and was employed for oxidative desulfurization(ODS)of dibenzothiophene(DBT)in model fuel with H2O_(2) as oxidant.The effect of different ope rating conditions(i.e.,reaction te mperature and time,catalyst dosage,H2O_(2)/DBT(O/S)molar ratio)were also systematic investigated.Under the optimal reaction condition,MoO_(x)@CN catalyst exhibited highly excellent ODS performance toward DBT,the highest sulfur removal efficiency can be up to 99.9%and sulfur content was wiped out from 800 ppm to 10 ppm.Due to the robust 3D structure promoting rapid transfer,in addition to the increased number of active sites induced by the Mo vacancies,the catalyst,prepared using chitosan and ammonium heptamolybdate in a mass ratio of 1:0.5,displayed rapid kinetics and low activation energy in the oxidation of dibenzothiophene.Moreover,it exhibited excellent recyclability after five cycles without any obvious decrease in catalytic activity for the oxidative desulfurization reaction.

Dynamic Model and Motion Characteristics of an Underwater Glider with Manta-inspired Wings

An underwater glider with bionic wings controlled by two operating modes is proposed to perform a variety of marine exploration tasks.The system composition of the vehicle and the structural design of wings inspired by manta ray are presented.The bionic wings can keep outstretched or realize oscillating motions according to the operating modes of the vehicle.A universal dynamic model of the vehicle was derived from multibody theory.Gliding,sailing and steering motions were simulated based on the dynamic model to illustrate the dynamic behaviors of the vehicle under different types of propulsion techniques.The results obtained through simulated calculation are basically consistent with the experimental data,which indicate that the developed dynamic model is applicable to describe the motion characteristics of the vehicle.Experiments were conducted in coastal area to analyze the propulsive characteristics of the bionic wings and sea trials involving multifarious motions were carried out,the applicability of the vehicle in marine environment was verified.

A Bionic Flexible-bodied Underwater Glider with Neutral Buoyancy

The buoyancy of traditional Underwater Glider(UG)with a rigid hull is aff ected by the changing marine parameters,making it difficult for the vehicle to dive deeper with good motion characteristics.In the present work,the development of a novel UG for neutral buoyancy,which is equipped with a Flexible-Liquid-Rigid(FLR)composite hull,is presented.The innovative hull that imitates the buoyancy regulation mechanism of marine organisms is easily adaptable to the changing marine environment.The rigid part of the composite hull withstands hydrostatic pressure for inner function modules of the vehicle.The liquid of the composite hull mainly serves as a buoyancy compensation to mitigate the eff ect of buoyancy variation caused by the changing marine parameters.The flexible covering provides a good hydrodynamic shape for the vehicle under the internal liquid pressure.The buoyancy variation due to the composite hull compression as well as changes of seawater density and temperature was comprehensively considered in the design process and integrated to the dynamic model.In addition,sea trials were performed to verify the motion characteristics of the proposed vehicle.The results reveal that the Flexible-bodied Underwater Glider(FUG)has a better gliding performance in practice.