OBJECTIVE:To study the anti-oxidative effects of spirulina kinase (SPK) in vitro. METHODS:The methods of phenanthroine-Fe2+ oxidation method,DPPH and auto-oxidation of pyrogallol were used to measure the effects of different concen-trations of SPK on scavenging hydroxyl (OH-) free radical,DPPH free radical and superoxide anion (O2-) free radical;IC50 of SPK was calculated. Prussian blue reaction was used to determine total reducing ability(by absorbance)of different concentrations of SPK to Fe3+. Vitamin C(VC)was used as positive control in above trials. RESULTS:SPK could eliminate the OH-free radical, DPPH free radical and O2- free radical in concentration-dependant manner,and the maximum elimination rate of SPK to OH- free radical and DPPH free radical were 86.82% and 78.98%(IC50 were 54.31,0.636 g/L),which were higher than VC (64.77%, 73.49%). The maximum elimination rate of SPK to O2- free radical was 78.31%(IC50 was 3.918 g/L),which was lower than VC (94.14%). In reducing ability test,SPK improved absorbance in reducing ability test system,and maximum absorbance was simi-lar to VC in concentration-dependant manner. CONCLUSIONS:SPK has obvious anti-oxidant activities in vitro.

Background::Understanding willingness to undergo pulmonary function tests (PFTs) and the factors associated with poor uptake of PFTs is crucial for improving early detection and treatment of chronic obstructive pulmonary disease (COPD). This study aimed to understand willingness to undergo PFTs among high-risk populations and identify any barriers that may contribute to low uptake of PFTs.Methods::We collected data from participants in the "Happy Breathing Program" in China. Participants who did not follow physicians’ recommendations to undergo PFTs were invited to complete a survey regarding their willingness to undergo PFTs and their reasons for not undergoing PFTs. We estimated the proportion of participants who were willing to undergo PFTs and examined the various reasons for participants to not undergo PFTs. We conducted univariable and multivariable logistic regressions to analyze the impact of individual-level factors on willingness to undergo PFTs.Results::A total of 8475 participants who had completed the survey on willingness to undergo PFTs were included in this study. Out of these participants, 7660 (90.4%) were willing to undergo PFTs. Among those who were willing to undergo PFTs but actually did not, the main reasons for not doing so were geographical inaccessibility ( n = 3304, 43.1%) and a lack of trust in primary healthcare institutions ( n = 2809, 36.7%). Among the 815 participants who were unwilling to undergo PFTs, over half ( n = 447, 54.8%) believed that they did not have health problems and would only consider PFTs when they felt unwell. In the multivariable regression, individuals who were ≤54 years old, residing in rural townships, with a secondary educational level, with medical reimbursement, still working, with occupational exposure to dust, and aware of the abbreviation "COPD" were more willing to undergo PFTs. Conclusions::Willingness to undergo PFTs was high among high-risk populations. Policymakers may consider implementing strategies such as providing financial incentives, promoting education, and establishing community-based programs to enhance the utilization of PFTs.