GO/HTPB composite liner for anti-migration of small molecules

Hydroxyl-terminated polybutadiene/toluene diisocyanate(HTPB/TDI)system is widely used in composite solid propellants.The migrations of plasticizers and water molecules from solid propellants and surrounding environment to the inhibitor have always been the important issues.This study focuses on the preparation,characterization and anti-migration behavior of graphene oxide(GO)/HTPB nanocomposite liner.The GO/HTPB(GH)composite liners affect the migration of small molecules through a tighter cross-linked structure and weakening function of small molecule adsorption.The anti-migration performance of the liner at different temperatures was analyzed,and the influence of the added amount of GO on the anti-migration performance and adhesion performance was also systematically studied.The overall performance of the liner is optimized when the amount of GO filler is 0.3 wt%.After adding 0.3 wt%GO,the concentration of dioctyl sebacate(DOS)migrated into the liner is decreased by 23.28%,and the concentration of water molecules is decreased by 51.89%,indicating that the introduction of GO can significantly improve the anti-migration performance of the liner.In addition,the bond strength is greatly increased from 0.25 MPa to 0.95 MPa,which meets the application requirements of the current propellant system.This research provides an important way for the preparation of structure-function synergistic anti-migration composite liners.

Ethylene-induced stomatal closure is mediated via MKK1/3–MPK3/6 cascade to EIN2 and EIN3

Mitogen-activated protein kinases(MPKs)play essential roles in guard cell signaling,but whether MPK cascades participate in guard cell ethylene signaling and interact with hydrogen peroxide(H2O2),nitric oxide(NO),and ethylene-signaling components remain unclear.Here,we report that ethylene activated MPK3 and MPK6 in the leaves of wild-type Arabidopsis thaliana as well as ethylene insensitive2(ein2),ein3,nitrate reductase1(nia1),and nia2 mutants,but this effect was impaired in ethylene response1(etr1),nicotinamide adenine dinucleotide phosphate oxidase AtrbohF,mpk kinase1(mkk1),and mkk3 mutants.By contrast,the constitutive triple response1(ctr1)mutant had constitutively active MPK3 and MPK6.Yeast two-hybrid,bimolecular fluorescence complementation,and pull-down assays indicated that MPK3 and MPK6 physically interacted with MKK1,MKK3,and the C-terminal region of EIN2(EIN2 CEND).mkk1,mkk3,mpk3,and mpk6 mutants had typical levels of ethylene-induced H2O2 generation but impaired ethylene-induced EIN2 CEND cleavage and nuclear translocation,EIN3 protein accumulation,NO production in guard cells,and stomatal closure.These results show that the MKK1/3–MPK3/6 cascade mediates ethylene-induced stomatal closure by functioning downstream of ETR1,CTR1,and H2O2 to interact with EIN2,thereby promoting EIN3 accumulation and EIN3-dependent NO production in guard cells.

Home-based spirometry in the self-management of chronic obstructive pulmonary disease

It is estimated that more than 3 million people die from chronic obstructive pulmonary disease(COPD)annually.Acute exacerbation of COPD(AECOPD)leads to an irreversible decline of pulmonary function,an increase of emergency visits,hospitalization and length of stay in hospital,and an increase of the mortality.However,many exacerbations are not reported to healthcare professionals for therapy and yet these events,although often in short durations,have a significant impact on health status.111 Early detection and intervention of AECOPD as well as reducing of unreported episodes of AECOPD will potentially improve the prognosis.