An Effective Green Porous Structural Adhesive for Thermal Insulating,Flame-Retardant,and Smoke-Suppressant Expandable Polystyrene Foam

To develop an efficient way to overcome the contradiction among flame retardancy,smoke suppression,and thermal insulation in expanded polystyrene(EPS)foams,which are widely used insulation materials in buildings,a novel"green"porous bio-based flame-retard ant starch(FRS)coating was designed from starch modified with phytic acid(PA)that simultaneously acts as both a flame retardant and an adhesive.This porous FRS coating has open pores,which,in combination with the closed cells formed by EPS beads,create a hierarchically porous structure in FRS-EPS that results in superior thermal insulation with a lower thermal conductivity of 27.0 mW·(m·K)^(-1).The resultant FRS-EPS foam showed extremely low heat-release rates and smoke-production release,indicating excellent fire retardancy and smoke suppression.The specific optical density was as low as 121,which was 80.6%lower than that of neat EPS,at 624.The FRS-EPS also exhibited self-extinguishing behavior in vertical burning tests and had a high limiting oxygen index(LOI)value of 35.5%.More interestingly,after being burnt with an alcohol lamp for 30 min,the top side temperature of the FRS-EPS remained at only 140℃with ignition,thereby exhibiting excellent fire resistance.Mechanism analysis confirmed the intumescent action of FRS,which forms a compact phosphorus-rich hybrid barrier,and the phosphorus-containing compounds that formed in the gas phase contributed to the excellent flame retardancy and smoke suppression of FRS-EPS.This novel porous biomass-based FRS system provides a promising strategy for fabricating polymer foams with excellent flame retardancy,smoke suppression,and thermal insulation.

Clinical features and prognosis of patients with novel coronavirus pneumonia complicated with diabetes

Objective:To analyze the clinical characteristics and laboratory examinations of patients with new coronavirus(COVID-19)and compare the effect and prognosis of patients with diabetes mellitus(DM)on COVID-19.Methods:56 cases of COVID-19 with DM and 85 age-matched admitted patients without DM who were admitted to the People's Hospital of Wuhan University from January 31,2020 to March 15,2020 were analyzed through a retrospective cohort study.Patients data were collected through electronic cases,and used SPSS 26.0 and Graphpad Prism 8.0 statistical software to compare changes in various indicators of patients in DM and non-DM groups and to draw the survival curves.Results:Compared with the non-DM group,the DM group has a higher percentage of mechanical ventilation,higher mortality and severe patients,with a higher proportion of initial symptoms of nausea and hypertension(P<0.05).There were no significant differences in the gender,initial symptoms(except nausea),the combined underlying diseases(except hypertension)between the two groups(P<0.05);The white blood cell,centroblast count,CRP,PCT,PT,D-dimer,total bilirubin,Urea,LDH,CK,MB,hs-TnI,CK-MB,NT-proBNP were higher in the DM group(P<0.05),and lymphocytes,single Nuclear cell,CD3,CD4,and CD8 counts were low(P<0.05).There was no statistically significant difference in platelet,IL-6,APTT,ALT,AST,Cr and CD19 counts between the two groups.Conclusion:Compared with COVID-19 patients with non-DM,COVID-19 patients with DM have a higher proportion of mortality and severe cases.Heart function,liver and kidney function,immune function damage and coagulation dysfunction are more obvious.Therefore,the monitoring of such patients should be strengthened,and active treatment should be performed to improve the prognosis.

Gastrointestinal symptoms and liver injury of COVID-19

COVID-19 is caused by the SARS-COV-2,which characterized with typical respiratory symptoms.In addition to the respiratory system injury,SARS-COV-2 may also invade other organs that express the cell surface receptor ACE2.Digestive system is a susceptible target of SARS-COV-2.Most patients show clinical symptoms of impaired digestive system during the course of the disease.Gastrointestinal symptoms of COVID-19 include anorexia,nausea,vomiting,diarrhea,abdominal pain,and liver damage.Patients with abnormal symptoms of the digestive system have a greater chance of progressing to severe or critical illness,a worse prognosis,and a higher risk of death.This paper aims to discuss the digestive symptoms of COVID-19 infection,so as to improve the attention to the digestive system abnormalities and gastrointestinal symptoms of COVID-19 patients during clinical diagnosis,treatment and prevention and control.

Porous carbon/Fe composites from waste fabric for high-efficiency electromagnetic wave absorption

Nowadays,a large amount of waste fabrics has brought huge environmental and resource problems,while the traditional recycling routes are downcycling with low efficiency and complex separation processes.Herein,we demonstrate a green and facile route to up-recycle waste fabrics(cotton-polyester blending or cotton fabrics)into a high-performance microwave absorber.In this design,an assistant coating was deposited onto the fiber surface of the waste fabric through the assembly of tannic acid-Fe^(2+)(TA-Fe^(2+)),which effectively catalyzed the polymer fiber into highly graphitized porous carbon fiber at high temper-atures.Meanwhile,the Fe nanoparticles from the reduction of Fe^(2+)ions were evenly embedded on the surface of porous carbon fibers.Consequently,the resultant porous carbon/Fe composites with hierarchi-cal microstructures displayed excellent microwave absorption performances.Typically,the microwave ab-sorber from waste polyester-cotton blended fabric could reach a minimum reflection loss(RL)of-50.5 dB at a thin coating thickness of 1.7 mm,and the minimum RL from waste cotton fabric absorber reached-47.1 dB at a thickness of 2.5 mm.This work provides a new idea to convert waste fabrics into high value-added microwave absorbing materials in a simple and environmentally friendly way,which will help reuse resources and protect the environment.