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BackgroundCOVID-19 has posed a global threat due to substantial morbidity and mortality, and health education strategies need to be adjusted accordingly to prevent a possible epidemic rebound. ObjectiveThis study aimed to evaluate the perceptions of COVID-19 among individuals coming to, returning to, or living in Jiangsu Province, China, and determine the impact of the pandemic on the perceptions of the public. MethodsIn this study, an online questionnaire was distributed to participants between February 15 and April 21, 2020. The questionnaire comprised items on personal information (eg, sex, age, educational level, and occupation); protection knowledge, skills, and behaviors related to COVID-19; access to COVID-19–related information; and current information needs. Factors influencing the knowledge score, skill score, behavior score, and total score for COVID-19 were evaluated using univariate and multivariate analyses. The time-varying reproduction number (Rt) and its 95% credible interval were calculated and compared with the daily participation number and protection scores. ResultsIn total, 52,066 participants were included in the study; their average knowledge score, skill score, behavior score, and total score were 25.58 (SD 4.22), 24.05 (SD 4.02), 31.51 (SD 2.84), and 90.02 (SD 8.87), respectively, and 65.91% (34,315/52,066) had a total protection score above 90 points. For the knowledge and skill sections, correct rates of answers to questions on medical observation days, infectiousness of asymptomatic individuals, cough or sneeze treatment, and precautions were higher than 95%, while those of questions on initial symptoms (32,286/52,066, 62.01%), transmission routes (37,134/52,066, 71.32%), selection of disinfection products (37,390/52,066, 71.81%), and measures of home quarantine (40,037/52,066, 76.90%) were relatively low. For the actual behavior section, 97.93% (50,989/52,066) of participants could wear masks properly when going out. However, 19.76% (10,290/52,066) could not disinfect their homes each week, and 18.42% (9589/52,066) could not distinguish differences in initial symptoms between the common cold and COVID-19. The regression analyses showed that the knowledge score, skill score, behavior score, and total score were influenced by sex, age, educational level, occupation, and place of residence at different degrees (P

Precipitation and incoming water are the key contributing factors to local flooding events, and analyzing the intra-annual distribution and change characteristics of precipitation and incoming water will be beneficial to the understanding of flooding contributing factors in this region. In this paper, the characteristics of intra-annual distribution of precipitation and incoming water and the synchronization of their changes in the lower reaches of the Yangtze River Basin (LYRB) from 1980 to 2020 are studied using the concentration degree and concentration period as quantitative indicators. The results are as follows: 1) the maximum precipitation occurs earlier in the year, while maximum incoming water occurs with little variation in timing but significant variation in total volume; 2) the concentration degree of both precipitation and incoming water show a slowly decreasing trend. The concentration period of precipitation is slightly advanced, and that of incoming water is significantly delayed; 3) the occurrence time and concentration period of the incoming water peak during 2010–2020 lagged behind that of precipitation, which played a role in suppressing the occurrence of floods in the LYRB. This study can provide a scientific basis for the future supply and demand of water resources in the LYRB for safe use.

In order to prevent fucoxanthin degradation in the stomach before entering the intestine, pH-sensitive nanoparticles based on fucoidan and chitosan were constructed for the efficient delivery of fucoxanthin in the gastrointestinal environment. In this study, fucoxanthin and a fucoidan fraction were extracted from Sargassum horneri. High performance liquid chromatography (HPLC) was used to determine the purity of fucoxanthin. High performance gel permeation chromatography (HPGPC), chemical methods and HPLC were used to determine the molecular mass, physicochemical characteristics and monosaccharide composition of the fucoidan fraction. Fucoxanthin-loaded nanoparticles with different fucoidan/chitosan mass ratios of 0.6:1, 0.8:1 and 1:1 were prepared by polyelectrolyte self-assembly. Fourier transform infrared (FTIR) spectroscopy was used to evaluate the interaction between fucoidan and chitosan, and the physicochemical characteristics of fucoxanthin-loaded nanoparticles and the changes in its size, fucoidan-loading rate, and fucoxanthin-loading rate during simulated gastrointestinal digestion were determined to evaluate the stability of the nanoparticles in the gastrointestinal tract. Results indicated that the purity of fucoxanthin from S. horneri was 13.57%. The average molecular mass of the fucoidan was 342 kDa. The contents of total sugar, protein, uronic acid and sulfate group in it were 52.45%, 7.96%, 9.25% and 19.26%, respectively. Moreover, the fucoidan was composed of fucose, galactose, mannose, glucuronic acid and xylose, among which fucose and galactose were the most abundant monosaccharides. FTIR spectra showed non-covalent interactions between fucoidan and chitosan in the nanoparticles and good binding state between them. The particle size of fucoxanthin-loaded nanoparticles was 360–430 nm, the zeta potential was 26–31 mV, and the polydispersity index (PDI) was 0.23–0.27, indicating that the nanoemulsion was uniform and stable. The fucoidan-loading rate was 87%–90%, and the fucoxanthin-loading rate was 87%–91%, indicating that fucoxanthin was well encapsulated in the nanoparticles. In vitro simulated digestion experiments showed that the particle size, fucoidan-loading rate and fucoxanthin-loading rate of the nanoparticles in simulated gastric juice did not change significantly, indicating that the nanoparticles were stable in simulated gastric environment. In simulated intestinal fluid, the particle size increased significantly, and the fucoidan-loading rate as well as fucoxanthin-loading rate decreased significantly, indicating the expansion and depolymerization of the nanoparticles in simulated intestinal environment. As a result, efficient delivery of fucoxanthin in simulated gastrointestinal tract was accomplished. At the fucoidan/chitosan mass ratio of 1:1, the effect was most obvious.

This study used a consensual qualitative research method to explore academic adaptation experiences of international students (N = 13) from East Asian countries at a U.S. university. The analysis yielded five domains from the data (challenges, feelings, strategies, suggestions, and self-reflections). Implications for college counselors, university administrators, and future research are discussed.