http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Anxiolytic effects of an acetylcholinesterase inhibitor, physostigmine, in the adult zebrafish
조하늘,이은경,이창중,최지선,황진수 한국통합생물학회 2012 Animal cells and systems Vol.16 No.3
Anxiety in zebrafish can be determined by examining their bottom-dwelling and light-avoidance behavior. This study determines the effects of physostigmine and scopolamine on anxiety in zebrafish by measuring swimming frequency for three horizontal layers and three vertical columns of a water test tank illuminated by a light source located above the central surface of the tank. In the 1 h session, zebrafish in the control group preferred the bottom layer the most and the center column the least. Zebrafish treated with 220 mM physostigmine were more likely to prefer the top layer than controls, and there were significant pairwise differences between physostigmine-treated zebrafish and controls, indicating the anxiolytic effect of physostigmine. Further, 10 and 20 mM physostigmine-treated zebrafish no longer avoided the center column. Scopolamine had no anxiolytic effect on bottom-dwelling and light-avoidance behaviors but suppressed the anxiolytic effect of physostigmine. In terms of their preference for various zones formed by layers and columns, zebrafish in the control group preferred the bottom left and right zones the most. Physostigmine had a positive effect on the preference for the top center zone, which was suppressed by scopolamine pretreatment. The results suggest that the level of anxiety in zebrafish can be reduced by activating acetylcholinergic neurotransmitter systems, which is mediated in part by muscarinic receptors.
김정환,조하늘,오광철 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.1
본 연구에서는 수치해석을 통한 카본블랙 마스터배치 생산용 이축 스크류 압출기의 구조분석이 진행되었다. 마스터배치는 플라스틱 생산품에 색상 및 기능을 부여할 수 있는 첨가제로써 비산방지와 분산성을 증가시키는 장점이 있다. 대표적으로 카본블랙, 실리카 등이 사용되며 카본블랙은 표면적이 큰 미분체로 응집현상이 발생되어 쉽게 분산되지 않기 때문에 압출기내 혼합이 어려워 생산성의 감소를 야기한다. 본 연구에서는 1차원 수치해석 프로그램을 이용하여 스크류 배열, 스크류 회전수, 배럴 온도, 다이형상 및 온도, 공급량 등의 조절을 통해 압출기 내 유동 특성 분석이 이루어졌다. 분석 결과 카본블랙 함량 증가에 따라 스크류 내부 온도 및 점도, 압출기 내부 소모에너지가 증가되며 평균 체류시간은 감소하는 결과를 도출하였다.
김현우,조하늘,유병완,김지효,이태범 한국약용작물학회 2018 한국약용작물학회지 Vol.26 No.4
Background: The Rosa multiflora, a well-known plant belonging to Rosacea, is widely used in orthodox medicine in worldwide. However, its biological activity and cosmetic preservative efficacy have not yet been studied. Thus, this species is yet to be defined as a functional cosmetic material. Accordingly, an investigation of the above mentioned atrributes was performed on a 50% ethanol extract of Rosa multiflora. Methods and Results: The antioxidant activity was assessed through free radical scavenging assays with 2,2-diphenyl-1-picrylhydrazyl (DPPH). Additionally, the contents of total phenols and flavonoids were analyzed. The phenolic compounds were detected using HPLC. The antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans was assessed using the disc diffusion assay. The preservative effect (challenge test) on a formulation of soothing gel was performed for 28days. The DPPH radical scavenging ability, denoted by the SC50 (half maximal inhibitory concentration for DPPH radical scavenging) value was found to be 131.63 ㎍/㎖. The content of total polyphenol and flavonoid content were 202 ㎎/g and 86.77 ㎎/g, respectively. In additon, astragalin and gallic acid were identified in the extract. The antimicrobial activity of the extract against S. aureus and E. coli was observed to be 5 - 0.5%, and no significant activity was noted against C. albicans. The ethanol extracts (5% and 10%) met the preservation standards of the Cosmetics, Toiletry, and Fragrance Association (CTFA). Conclusions: Thus the ethanol extract of R. multiflora can be used in cosmetics as a natural preservative and antioxidant.