RESUMO
An orthogonal experiment was designed to prepare different UV topcoat microcapsules by adjusting the mass ratio of wall material to core material, HLB value of emulsifier, reaction temperature, and reaction time of UV topcoat microcapsule. By testing the morphology and multiple properties of UV topcoat microcapsules, it was found that the biggest factor affecting the synthesis of UV topcoat microcapsules is the emulsifier HLB value. In order to further optimize the performance of UV topcoat microcapsules, a single-factor experiment was conducted with the emulsifier HLB value as the variable, and it was found that the UV topcoat microcapsules achieved the best performance when the emulsifier HLB value was 10.04. The optimal UV topcoat microcapsules were added to the UV topcoat at different amounts to prepare UV topcoat paint films. Through testing the various properties of the UV topcoat paint film, it was determined that the performance of the UV topcoat paint film was optimal when the amount of UV topcoat microcapsules added to the UV topcoat was 4.0%. The optical properties of the UV topcoat paint film were tested, and the effect of UV topcoat microcapsules on the color difference and glossiness of the UV topcoat paint film was not significant. The tensile and self-healing performance of UV topcoat microcapsules were tested. UV topcoat microcapsules can enhance the toughness of the UV topcoat paint film to a certain extent, suppress the generation of microcracks, and have a good self-healing effect. The results provide experimental support for the preparation of microcapsules using UV coatings as core materials for the self-healing of UV coatings.
RESUMO
An orthogonal experiment with four factors and three levels was designed. Nine different microcapsules were prepared by changing four factors: the core-wall ratio, emulsifier concentration, reaction temperature, and rotation speed. Through an analysis of the microcapsule yield and morphology, it was determined that the microcapsule of sample 6 performed the best in the orthogonal test and that the core-wall ratio was the largest factor affecting the microcapsule morphology and yield. In order to further optimize the performance of the microcapsules, single factor independent tests were carried out using the core-wall ratio as a single variable. It was found that the microcapsules with the core-wall ratio of 0.75:1 had good micro morphology and yield. The properties of the coating were the best when the microcapsules were added into the primer and the topcoat at the same time with an additional amount of 10.0%. The mechanical properties of the coating containing cellulose microcapsules and the coating without cellulose microcapsules were tested. Cellulose can enhance the toughness of the microcapsules, inhibit the generation of microcracks, and enhance the performance of the coating to a certain extent. The elongation at break of the coating with cellulose microcapsules was 9.49% higher than that without cellulose and was 11.1% higher than that without cellulose microcapsules.
RESUMO
OBJECTIVE: To evaluate the association between runt-related transcription factor 3 (RUNX3) gene promoter hypermethylation and gastric cancer risk by meta-analysis. MATERIALS AND METHODS: By searching Medline, EMBASE, Ovid, China National Knowledge Infrastructure and Wanfang databases, the open published articles reporting the relationship between RUNX3 gene promoter hypermethylation, and gastric carcinoma risk, were screened. The aggregated odds ratio of RUNX3 gene promoter hypermethylation in cancerous sample of gastric cancer patients compared to normal gastric tissue of gastric cancer patients was pooled by statistic software STATA-11.0. RESULTS: Sixteen studies include 2631 samples were finally included in this meta-analysis. The aggregated results indicated that the hypermethylation rate in cancerous tissue was much higher than that in normal tissue (55.1% vs. 26.5%, P < 0.05). And the pooled results showed that the RUNX3 gene promoter methylation odds in tumor tissue in gastric cancer patients compared to normal gastric tissue was 5.47 (95% confidence interval: 3.34-8.96). CONCLUSION: RUNX3 gene promoter hypermethylation rate was much higher in tumor tissue than that in normal gastric tissue in the patient with gastric cancer.