거리노숙인의 만성노숙과 연관된 인구사회학적, 임상적 변인

이승홍,배치운,고효정,정운진,고상현 대한신경정신의학회 2016 신경정신의학 Vol.55 No.4

ObjectivesZZThis exploratory study was designed to estimate the socio-demographic characteristics, course of homelessness, adverse childhood experiences, and prevalence of mental disorders among the street homeless people in Seoul, Korea. In addition, we examined the associations between chronic homelessness and study variables. MethodsZZThe study subjects were 75 homeless people dwelling in the street around Seoul Station. Questionnaires related to socio-demographic data and the course of homelessness were provided to each subject. The subjects’ Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) mental disorder diagnoses were made by using Mini International Neuropsychiatric Interview-Plus interviews. ResultsZZMost subjects exhibited chronic homelessness and the prevalence of DSM-IV mental disorders among the homeless subjects was higher than that among the Korean general population. There was a statistically significant association between chronic homelessness and adverse childhood experiences. Compared to those with no history of childhood adversity, homeless people with a history of childhood adversity had a younger age of first homeless episode and a higher prevalence of DSM-IV major mental disorders. The association between DSM-IV diagnosis and chronic homelessness was not significant, but the group with mental disorders had more prevalent re-housing and homeless recurrent histories. ConclusionZZStreet homeless people were often involved in chronic homelessness. Results of this study suggest that homeless people who were never married and had adverse childhood experiences were more vulnerable to chronic homelessness. In addition, we detected a possible relationship between the recurrence of homelessness and the presence of mental disorders.

Laser 광을 이용한 얇은 액체의 유속 측정

이승홍 부산대학교 공과대학 1993 工大論文集 Vol.46 No.-

Local velocities inside liquid streams from very small nozzles and in very thin liquid film flows have been measured by using micrometric translators, dual beam laser Doppler velocimetry system and micro particles. Fine MgO particles have been used in velocity measurements and particle sizing has been investigated by analyzing laser Doppler visibility, and also measurements of size and velocity have been studied simultaneously by phase Doppler technique of Particle Dynamics Analyzer. Particle technology of the laser Doppler anemometer and micro-translators are practically very important tools for the precise fluid velocity measurements.

小型 蒸氣 壓縮 冷凍 시스템에 대한 시뮬레이션 모델 開發

李承洪,禹成雨 부산대학교 공과대학 1991 工大論文集 Vol.41 No.-

The property equations developed to describe the thermodynamic behavior of refrigerants and calculation methods are presented. The utilization of computer which is lately being developed in various field enables the related researcher to calculate thermodynamic properties under any conditions in vapor-compression system. Refrigerant 12 is selected as a sample calculation of standard vapor compression refrigeration cycle. The objects of this investigation are: 1. To calculate thermodynamic properties of R-12 and other refrigerants in the area of saturated state and superheated vapor by computer programming. 2. To simulate the standard vapor-compression refrigeration cycle that operates between high pressure and low pressure

단면 계수 비교에 의한 차체 구조용 부품의 경제성에 관한 연구

이승홍,강창수 慶北大學校 1973 論文集 Vol.17 No.-

This study is aimed that the economic section of vehicle frame parts is to be found under the stable state of stress. Vehicle skeleton of the side wall and the roof should be designed to form a circumferential unit for a favorable flow of forces. Stability of the stress condition and the economic section of the vehicle frame parts are basic problems in the design of the vehicle body. Finding the economic section, first of all, we supposed the vehicle frame part is a beam under pure bending moment. Therefore, we think the method of comparision with production cost to section modulus of the vehicle frame parts will be one of the basic and good economic approach. The calculation of the sectionmodulus is shown on Table-1, Table-2, Table-3. Table-3 is the comparison list between the section modulus and cost of the each vehicle frame parts. Fig-9 shows correlation between the section modulus and the cost of the above vehicle frame parts. Results from the Fig-9 are recorded in the result part.

Evaluation of the Antioxidant Properties of Pediastrum duplex and Dactylococcopsis fascicularis Microalgae

이승홍,이원우,이준백,전유진 한국수산과학회 2010 Fisheries and Aquatic Sciences Vol.13 No.1

Interest in plant-derived food additives has increased recently, with efforts to identify natural antioxidant sources to replace synthetic antioxidants. This study evaluated the antioxidant effects of organic solvent fractions of 80% methanol extracts from Pediastrum duplex and Dactylococcopsis fascicularis microalgae. Among the solvent fractions tested, the ethyl acetate and n-hexane fractions from P. duplex effectively scavenged 79.8% and 74.5% of DPPH free radicals, respectively. The chloroform fraction from D. fascicularis showed the strongest H2O2 scavenging ability (49.7%). The greatest scavenging of hydroxyl radicals (73.1%) was exhibited by the 80% methanol extract from P. duplex. Aqueous residue and ethyl acetate fraction from P. duplex provided the strongest nitric oxide scavenging (57.7%) and metal chelating effect (82.1%), respectively. Chloroform and ethyl acetate fractions from P. duplex and n-hexane fraction from D. fascicularis exhibited significantly greater inhibition of lipid peroxidation than the commercial antioxidants. These results suggested that P. duplex and D. fascicularis microalgae having potential antioxidative compounds with various properties could be utilized in the food and pharmaceutical industries.

Cellular activities and docking studies of eckol isolated from Ecklonia cava (Laminariales, Phaeophyceae) as potential tyrosinase inhibitor

이승홍,Sung-Myung Kang,Chang Hyun Sok,홍진태,오재영,You-Jin Jeon 한국조류학회I 2015 ALGAE Vol.30 No.2

Tyrosinase inhibitors are an important component of cosmetic products. Our previous studies have proposed that eckol isolated from the brown alga Ecklonia cava, can be explored as a tyrosinase inhibitor. However, cellular activities and mechanism of action of eckol remain unknown. Therefore, the current study analyzed the eckol binding modes using the crystal structure of Bacillus megaterium tyrosinase. The effects of eckol on melanin synthesis induced by α-melanocyte stimulating hormone in B16F10 melanoma cells were also investigated. We predicted the 3D structure of tyrosinase and used a docking algorithm to simulate binding between tyrosinase and eckol. These molecular modeling studies were successful (calculated binding energy value, -115.84 kcal mol-1) and indicated that eckol interacts with Asn205, His208, and Arg209. Furthermore, eckol markedly inhibited tyrosinase activity and melanin synthesis in B16F10 melanoma cells. We also found that eckol decreased the expression of tyrosinase, tyrosinase-related protein (TRP) 1, and TRP2. These results indicate that eckol is a potent inhibitor of melanogenesis, and this finding may be useful for the development of novel pharmaceutical and cosmetic agents.

수평 원관의 비등 열전달에서 강제대류의 영향

이승홍,이억수,정은행 대한설비공학회 1998 설비공학 논문집 Vol.10 No.5

This paper presents the results of experiments involving external forced convection on boiling heat transfer from electrically heated horizontal tube to water in cross flow. In these experiments, all of the following primary variables were varied: heat flux, cross flow velocity, pressure and degree of subcooling. Local surface temperatures were measured at nine peripheral positions. Surface temperature distributions are classified into four groups as a function of heat flux. The characteristics of the boiling curve at different velocity, degree of subcooling and pressure are examined.

Antioxidant properties of tidal pool microalgae, Halochlorococcum porphyrae and Oltamannsiellopsis unicellularis from Jeju Island, Korea

이승홍,이준백,이기완,전유진 한국조류학회I 2010 ALGAE Vol.25 No.1

In this study, we assessed the antioxidant properties of tidal pool microalgae, Halochlorococcum porphyrae and Oltamannsiellopsis unicellularis, from Jeju Island, Korea. Specifically, the antioxidant activity of fractions isolated from 80% methanol extract, and digests produced from five proteases and carbohydrases, were investigated. Almost all the fractions and the 80% methanol extract exhibited higher effects on 1,1-Diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging. The ethyl acetate fraction showed the highest superoxide anion scavenging activity, while both n-hexane and chloroform fractions exhibited higher H2O2 scavenging activity. Among the enzymatic digests from H. porphyrae and O. unicellularis, all the digests exhibited remarkable DPPH scavenging activities. In nitric oxide inhibition, all the digests recorded significantly higher effects than those of the commercial antioxidants (p < 0.05). Flavozyme and Neutrase digests from H. porphyrae, and Termamyl and Alcalase digests from O. unicellularis, showed significant effects in metal chelating. Lipid peroxidation was significantly inhibited in the ethyl acetate fraction, in the Celluclast and Protamex digests from H. porphyrae, and in the chloroform fraction from O. unicellularis. These findings suggest that the two tidal pool microalgae tested in this study are rich in potential antioxidative compounds, the specific properties of which can be considered for use in the food and pharmaceutical industries.

Potential of Benthic Diatoms Achnanthes longipes, Amphora coffeaeformis and Navicula sp. (Bacillariophyceae) as Antioxidant Sources

이승홍,Rohan Karawita,Abu Affan,Joon-Baek Lee,Ki-Wan Lee,이배진,Dong-Woo Kim,전유진 한국조류학회I 2009 ALGAE Vol.24 No.1

Recently, interest in plant-derived food additives has developed natural antioxidants, in order to alternate synthetic antioxidants with several disadvantages. In the present study, different organic fractions from solvent partitions of 80% methanol extract from Jeju benthic diatoms, Achnanthes longipes, Navicula sp. and Amphora coffeaeformis was assessed for their potential antioxidant effects. Among the solvent fractions tested, n-hexane (80.4%) and 80% methanol extract (76.6%) from A. longipes, chloroform (63.2%) from Navicula sp. and n-hexane (67.4%) from A. coffeaeformis were effective in DPPH free radical scavenging. Fractions of chloroform (53.4%) and n-hexane (53.1%) from A. longipes exhibited higher activities on H2O2 scavenging. Fraction of n-Hexane from A. longipes exhibited the highest hydroxyl radical scavenging activity and NO· scavenging activity (56.5% and 75.6%, respectively). Aqueous residue from A. coffeaeformis (75.6%) showed the highest metal chelating effect. Chloroform and ethyl acetate fraction of all the diatoms exhibited significant antioxidant activities in lipid peroxidation inhibitory activity. In particular, both chloroform and the ethyl acetate fraction from A. longipes and A. coffeaeformis exhibited lipid peroxidation inhibitory activity significantly higher than that of α- tocopherol. These data suggest that the Jeju benthic diatoms tested are rich in hydrophilic and hydrophobic antioxidative compounds with different antioxidative properties that can be applied in food industry.

‘전공의 특별법’ 통과, 한국 의료체계를 변화시킬 지렛대가 될 것인가

이승홍 연구공동체 건강과대안 2016 의료와사회 Vol.- No.3