The crude methanol extract of the dried aerial parts of Siegesbeckia glabrescens (Compositae) showed antibacterial activity against the foodborne pathogen Staphylococcus aureus. Bioactivity-guided separation led to the isolation of 3-(dodecanoyloxy)-2-(isobutyryloxy)-4-methylpentanoic acid from nature for the first time.The structure was determined by spectroscopic data analysis (UV, MS, and NMR). The minimal inhibitory concentration (MIC) of 3-(dodecanoyloxy)-2-(isobutyryloxy)-4-methylpentanoic acid against S. aureus was found to be 3.12 μg/mL. In addition, in a further antimicrobial activity assay against Gram-positive (B. subtilis, E. faecalis, P. acnes, S. epidermidis, S. schleiferi subsp. coagulans, S. agalactiae and S. pyrogens), and Gram-negative bacteria (E. coli and P. aeruginosa), and yeast strains (C. alibicans and F. neoformans), the antimicrobial activity of the compound was found to be specific for Gram-positive bacteria. The MIC values of the compound for Gram-positive bacteria ranged from 3.12 to 25 μg/mL. Furthermore, it was found that the 2-(isobutyryloxy)-4-methylpentanoic acid substituent may operate as a key factor in the antibacterial activity of the compound, together with the laurate group.
This study intends to improve the radiation safety management and the recognition for handling radiation using structured questionnaires to dental hygienists working at Jeollabuk-do from September 1 to October 31 in 2014. As a result, 63% of respondents have not received education for radiation safety management. Moreover, the practical degree for radiation safety management was 2.58±1.11, while the degree of knowledge was 3.74±0.83 of total 5.0. The results of insecurity for radiation danger were high as 3.88±0.92, and insecurity for fetus during pregnancy shows the highest value as 4.43±0.71. From the results of statistical significance level, the knowledge degree of radiation safety management is affected by total numbers of radiograpy for a day (p<0.05), and the practical degree of radiation safety management is affected by age group, academic background, monthly income, continuous service year, practice area, present position, and status of radiography in present (p<0.05). In addition, the knowledge degree of radiation safety management have a negative correlation (r=-0.232) with the practical degree, but have a positive correlation (r=0.262) with the insecurity for radiation danger. The high knowledge degree of radiation safety management (=0.252, p<0.001) and the short radiography work period (=-0.341, p<0.05) were the influential factors to the insecurity for radiation danger. Consequently, countermeasures are necessary to encourage dental hygienists to put their radiation safety management knowledge into the practice and to reduce the insecurity degree for radiation danger. Furthermore, it is important to prevent psychological and physical risks by radiation exposure through the improvement of radiation safety management level and recognition for handling radiation to improve medical environment.
Objectives:The purpose of the study is to investigate the current status and radiographic safety management in Korea. Methods: A self-reported questionnaire was completed by 200 dental hygienists in Jeonbuk province from September 1, 2014 and October 31, 2014. The questionnaire consisted of general characteristics of the subjects, radiation knowledge, radiation safety management, and radiation exposure anxiety. Data were analyzed using SPSS 18.0 program. Results: Duration of clinical experience(r=0.142) and number of daily radiation shot(r=0.145) showed a positive correlation to radiation safety management, and a nrgative correlation to use of intraoral films and digital devices(r=-0.587). A logistic regression analysis was performed in order to evaluate the influence on radiography knowledge. The results showed that the factors had significant influences on the age group over 41 years old(OR 7.25; 95% CI 1.30-40.43) and those who took a position above team leader (OR 0.23;. Conclusions: It is very important to have the safety management toward dental intraoral imaging and radiograpgic shot in the dental hygienists. Continuous efforts should be emphasized on radiographic safety management and behavior.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.