化妆品用改性山茶油制备工艺研究

以山茶油水解产物和聚乙二醇600(PEG600)为原料,在高温下进行酯化反应制备改性山茶油。考察了催化剂种类和用量、反应温度、投料比及反应时间对酯化反应的影响。根据单因素试验得出制备改性山茶油的最佳工艺条件为:预热温度80℃,预热时间5 min,4 ?型分子筛为催化剂,催化剂用量0. 4%,反应温度160℃,投料比(PEG600与山茶油水解产物摩尔比) 1∶1. 2,反应时间6. 5 h。在最佳工艺条件下,酯化率为93. 16%,产物改性山茶油能与水以任意比例互溶。对产物分离纯化后,经定性试验以及红外光谱和超高效液相色谱-质谱(UPLC-MS)分析,发现改性山茶油的主要成分是聚乙二醇单、双酯。同时对产物的各项性能进行测试,其含水率为0. 67%、皂化值(KOH)为110. 2 mg/g、过氧化值为4. 6 mmol/kg、临界胶束浓度为1. 5 g/L(此时表面张力为32. 01mN/m)、HLB值为14、乳化最大分水时间为9. 8 min。     

化妆品功效评价(Ⅵ)——化妆品人体功效评价的实验设计

概述了化妆品人体功效评价实验设计的概念、基本要素和基本原则,介绍了常用实验设计类型和实验设计要点,提供了人体功效评价实验方案设计的思路,有助于提高研究者制定实验设计方案的水平。     

Generation of Cochlear Hair Cells from Sox2 Positive Supporting Cells via DNA Demethylation

Regeneration of auditory hair cells in adult mammals is challenging. It is also difficult to track the sources of regenerated hair cells, especially in vivo. Previous paper found newly generated hair cells in deafened mouse by injecting a DNA methyltransferase inhibitor 5-azacytidine into the inner ear. This paper aims to investigate the cell sources of new hair cells. Transgenic mice with enhanced green fluorescent protein (EGFP) expression controlled by the Sox2 gene were used in the study. A combination of kanamycin and furosemide was applied to deafen adult mice, which received 4 mM 5-azacytidine injection into the inner ear three days later. Mice were followed for 3, 5, 7 and 14 days after surgery to track hair cell regeneration. Immunostaining of Myosin VIIa and EGFP signals were used to track the fate of Sox2-expressing supporting cells. The results show that (i) expression of EGFP in the transgenic mice colocalized the supporting cells in the organ of Corti, and (ii) the cell source of regenerated hair cells following 5-azacytidine treatment may be supporting cells during 5–7 days post 5-azacytidine injection. In conclusion, 5-azacytidine may promote the conversion of supporting cells to hair cells in chemically deafened adult mice.     

发用类、肤用清洁类化妆品的急性皮肤和眼刺激损害特点

分析发用类、肤用清洁类化妆品的急性皮肤刺激和急性眼刺激损害特点,了解其卫生安全状况。于2012年采用《化妆品卫生规范》(2007年版)中的急性皮肤刺激性实验和急性眼刺激性实验对发用类、肤用清洁类共计158种化妆品样品进行测试。两类受试化妆品显示出不同程度的急性皮肤刺激性和急性眼刺激性损害效应。发用类化妆品在实验中基本无皮肤刺激性损伤;肤用清洁类化妆品在实验中有少量的皮肤刺激性损伤,但大都为轻刺激性(31.0%),只有个别(3.8%)出现了皮肤红斑水肿的中刺激性损伤。发用类、肤用清洁类化妆品在急性眼刺激性实验中检出一定比例具有微刺激性及以上刺激性的样品,但引起的眼损伤都能够在观察期限内恢复。本次调查的所有化妆品中,洁面类、洗发类化妆品普遍具有急性眼刺激性和急性皮肤刺激性损害,需加强对化妆品的监督管理,进一步提升化妆品卫生安全水平,保障化妆品使用安全。     

Factors Affecting the Study of Chemistry in Different Countries Around the World: Findings from an International Survey

Improving teaching and student learning in chemistry classrooms is an important goal that is constantly researched. Several comparative studies of science teaching have been carried out on different parameters, e. g. misconceptions which science teachers and students may have regarding the scientific concepts they learn and teach. Here we describe science teaching in general, and chemistry teaching in particular, in 12 countries including Israel. Different parameters are compared, including the hours that are devoted to science, the subjects included, the pedagogy, and teachers′ salaries. The survey covers all school levels: elementary school, secondary school and high school. At the high‐school level, the comparison focused on chemistry studies. In this study the variances variables, such as the hours that are allocated for science teaching, did not show an appreciable effect on students′ achievements. It was also found that, in countries where chemistry studies at the high‐school level are not mandatory, innovative pedagogies are more likely to replace the traditional chemistry teaching methods where chemistry is taught according to the structure of the subject based on basic concepts that underlie the curriculum. The study provided an additional support to the importance of the professional development of science and chemistry teachers and suggest that the autonomy that is given to them could influence the quality of science teaching and students′ achievements.     

融媒体下新闻采编者的业务素养

随着新兴媒体的兴起与发展,传统的新闻媒体面临前所未有的机遇与挑战。融媒体时代的到来,实现了传统媒体与新兴媒体的融合发展,同时也对传统新闻媒体提出了更高要求。新闻采编者必须切实提升自身业务素养,方能适应新形势下的要求。着重论述了融媒体下新闻采编者业务素养存在的问题及应对措施。     

环境监测与控制技术专业创新创业改革研究

为充分发挥专业教育对大学生创新创业能力的培养作用，以某高职院校环境监测与控制技术专业创新创业教育为研究对象，从课程体系的建设、课堂教学改革、教师队伍建设、实训基地建设、制度创新等方面进行分析研究，探索创新创业改革的有效路径。     

Exchanging social support on online teacher groups: Relation to teacher self-efficacy

The present study explored the relation between exchanging social support on online teacher groups and teacher self-efficacy. An online survey was conducted inside a massive Facebook teacher group, and 584 elementary school teachers provided information regarding Facebook use, self-efficacy for creative teaching, and the extent to which they provided and received support on the online teacher group. Results showed that teacher self-efficacy varied as a function of years of teaching experience, length of group membership, and the extent to which teachers provided and received social support on the online teacher group. Furthermore, the providing of online support predicted teacher self-efficacy after taking into account the effects of teaching experience and group membership. The findings are discussed in terms of the features and importance of social support exchange on online teacher support groups.