Effects of the source of information and knowledge of dengue fever on the mosquito control behavior of residents of border areas of Yunnan, China.

BACKGROUND: Strengthening the mosquito control measures undertaken by residents of an area where dengue fever is present can significantly decrease the spread of this disease. The aim of this study was to explore the effects of the source of information and knowledge of dengue fever on the mosquito control behavior of residents of areas at high risk of this disease to determine effective ways of enhancing this behavior. METHODS: A survey was conducted via face-to-face interviews or questionnaires between March and May 2021 in three regions of the province of Yunnan, China. The survey included basic information about the respondents, the source(s) of their dengue fever information, the level of their dengue fever knowledge, and the measures they had implemented to control mosquitoes. Principal component analysis was used to extract the main components of the sources of information. Correlation analysis and structural equation analysis were used to explore the impact of the sources of information and residents' dengue fever knowledge on their mosquito control behavior. RESULTS: Publicity achieved through mass media, including official WeChat accounts, magazines/newspapers, poster leaflets, television/radio and the Internet, had a direct effect on dengue fever knowledge and mosquito control behavior, and indirectly affected mosquito control behavior through dengue fever knowledge. Organized publicity campaigns, including information provided by medical staff and through community publicity, had a direct effect on dengue fever knowledge and indirectly affected mosquito control behavior through dengue fever knowledge. The residents' level of dengue fever knowledge had a significant, positive, direct effect on their mosquito control behavior. CONCLUSIONS: Mosquito control is an important measure for the prevention and control of outbreaks of dengue fever. An effective source of information can improve the level of dengue fever knowledge among residents and thus enhance their mosquito control behavior.

Preparation and Characterization of Pendimethalin Microcapsules Based on Microfluidic Technology.

Microencapsulation of pesticides is a promising attempt to reduce environmental pollution and prevent the active ingredients from the interference of external factors. In this paper, pendimethalin microcapsules were prepared by the interfacial polymerization of 4,4-methylenediphenyl diisocyanate (MDI) and ethylenediamine (EDA) based on microfluidic technology. Effects of the microchannel structure, reaction temperature, surfactant type, and fluid flow rates were investigated and evaluated. The results showed that pendimethalin microcapsules prepared under suitable conditions had a smooth surface, good monodispersity, a high encapsulation efficiency (96.7%), and excellent thermal stability. The size and morphology control of microcapsules were realized by adjusting the flow rates of the continuous phase and the hydrophilic monomer EDA aqueous solution. The release of pendimethalin had a sustained release characteristic that was closely related to the morphology of microcapsules. Compared with the pendimethalin emulsifiable concentrate, pendimethalin microcapsules exhibited outstanding herbicidal activity in the weed control experiments. Therefore, pendimethalin microcapsules with tunable properties were successfully obtained from the microfluidic device and showed great potential in agricultural applications.