Bronchial inflammatory profile in interferon-gamma-mediated immune response in asthma patients during airway response to cold stimulus

Objective:To evaluate the inflammatory pattern and the interferon(IFN)-γin the bronchial secretion of asthma patients in response to acute cold bronchoprovocation.Material and methods:We enrolled 42 patients with asthma.We assessed asthma by Asthma Control Test,the lung function by spirometry before and after the bronchodilator test,followed by collecting induced sputum.The next day,we collected exhaled breath condensate(EBC)and conducted a 3-minute isocapnic hyperventilation with cold air(IHCA),followed by collecting spontaneously produced sputum.Results:Group 1 included 20 patients with cold airway hyperresponsiveness(CAHR),and group 2 included 22 patients without CAHR.In both groups,a high level of neutrophils in bronchial secretion was observed before and after IHCA.In response to IHCA,the number of epitheliocytes in the sputum decreased to a greater extent in patients of group 1.The baseline epitheliocytes and the concentration of IFN-γafter IHCA had an inverse relationship(r=-0.60;P=0.017).The baseline IFN-γin EBC before and after IHCA was lower in group 1.Airway response to cold exposure directly correlated with IFN-γlevels after IHCA(Rs=0.42;P=0.014).Conclusion:In asthma patients with CAHR,there is a relationship between the persistence of mixed inflammation and the level of IFN-γin the bronchi.IFN-γin response to IHCA is decreased with increased cytokine utilization during cold bronchospasm,which is accompanied by the mobilization of neutrophils and the shift in the cytokine spectrum of the respiratory tract towards the T helper cells(Th)1 immune response.

Modeling the impact of surveillance activities combined with physical distancing interventions on COVID-19 epidemics at a local level

Physical distancing and contact tracing are two key components in controlling the COVID-19 epidemics.Understanding their interaction at local level is important for policymakers.We propose a flexible modeling framework to assess the effect of combining contact tracing with different physical distancing strategies.Using scenario tree analyses,we compute the probability of COVID-19 detection using passive surveillance,with and without contact tracing,in metropolitan Barcelona.The estimates of detection probability and the frequency of daily social contacts are fitted into an age-structured susceptible-exposed-infectious-recovered compartmental model to simulate the epidemics considering different physical distancing scenarios over a period of 26 weeks.With the original Wuhan strain,the probability of detecting an infected individual without implementing physical distancing would have been 0.465,0.515,0.617,and 0.665 in designated age groups(0e14,15e49,50e64,and>65),respectively.As the physical distancing measures were reinforced and the disease circulation decreased,the interaction between the two interventions resulted in a reduction of the detection probabilities;however,despite this reduction,active contact tracing and isolation remained an effective supplement to physical distancing.If we relied solely on passive surveillance for diagnosing COVID-19,the model required a minimal 50%(95%credible interval,39e69%)reduction of daily social contacts to keep the infected population under 5%,as compared to the 36%(95%credible interval,22e56%)reduction with contact tracing systems.The simulation with the B.1.1.7 and B.1.167.2 strains shows similar results.Our simulations showed that a functioning contact tracing program would reduce the need for physical distancing and mitigate the COVID-19 epidemics.

Studying the mixed transmission in a community with age heterogeneity: COVID-19 as a case study

COVID-19 has been prevalent worldwide for about 2 years now and has brought unprecedented challenges to our society.Before vaccines were available,the main disease intervention strategies were non-pharmaceutical.Starting December 2020,in Ontario,Canada,vaccines were approved for administering to vulnerable individuals and gradually expanded to all individuals above the age of 12.As the vaccine coverage reached a satisfactory level among the eligible population,normal social activities resumed and schools reopened starting September 2021.However,when schools reopen for in-person learning,children under the age of 12 are unvaccinated and are at higher risks of contracting the virus.We propose an age-stratified model based on the age and vaccine eligibility of the individuals.We fit our model to the data in Ontario,Canada and obtain a good fitting result.The results show that a relaxed between-group contact rate may trigger future epidemic waves more easily than an increased within-group contact rate.An increasing mixed contact rate of the older group quickly amplifies the daily incidence numbers for both groups whereas an increasing mixed contact rate of the younger group mainly leads to future waves in the younger group alone.The results indicate the importance of accelerating vaccine rollout for younger individuals in mitigating disease spread.

The gelation rule of the polyol acetal derivatives in binary solvent mixtures

The gelation properties of polyol acetal derivatives including 2,4-（3,4-dichlorobenzylidene）-D-sorbitol（DCBS）, 1,3：2,4-di（3,4-dichlorobenzylidene）-D-sorbitol（DDCBS） and 1,3：2,5：4,6-tris（3,4-dichlorobenzylidene）-D-mannitol（TDCBM） in 35 single solvents and 39 binary solvent mixtures have been studied. FTIR and XRD results suggest that the self-assembly patterns of the gelator will not change in either the single solvent component or the corresponding solvent mixtures, but the critical gelation concentration（CGC）will be influenced. The results of SEM and rheology showed that the formation of true gels at saturated concentrations. Improving the heating temperature may promote the dissolving of gelators which are even insoluble at the temperature of the solvent boiling point and change the gelation behaviors. FloryHuggins parameter（x） was used to predict the gelation behavior of DCBS in the mixed solvents, and it is shown that the x values for the mixed solvents that can be gelled by DCBS are either greater or smaller than those for the selected good solvents.