Barbituric acid 개시계 레진의 치질 접착성에 미치는 가교제의 영향

나환욱,이은경,김교한,강인규 대한치과기재학회 2001 대한치과재료학회지 Vol.28 No.2

Degree of polymerization, surface hardness and tensile bond strength of the bonding resin were carried out to examine the effect of crosslinking agent, triethylene glycol dimethacrylate(TEGDMA), on the adhesion of barbituric acid-initiated resin to dentin. As the results, degree of conversion and surface hardness increased with increasing the concentration of TEGDMA. Tensile bond strength of the resin increased with increasing the concentration of TEGDMA up to 6 wt% and, thereafter, decreased.

東海岸汽水湖의 陸水學的 硏究

洪思澳,羅圭煥 成均館大學校 1975 論文集 Vol.20 No.-

1. The quality of water and distribution of plankton were investigated of the 6 brackich lakes. Namely Hyang lake, Kwang po lake., Mai lake, Young rang lake, Song ji lake and Hwajin po lake, those which were situated in the east shore during May to December in 1972 and was studied limnological features of those 6 brackish lakes. 2. The average value of Cl'content, hardness and conductivity which had closely influence on the brackish water was measured in those 6 lakes. In the Hwa jin po lake, it found most high value of Cl'content, hardness and conductivity than the other 5 lakes and in the Kwang po lake, it found most lower value of those than the others. 3. From view point of monthly variation of the quality of water, the average value of Cl^-content, hardness and conductivity were a little higher during May and December than during August and October. Compared with the quality of water during May and during Deumber, during May it was substantially higher than during December. In all of the examined lakes except Song ji and Young rang it was substantially higher during August than during September but in Kwang po and Mai lakes, the average value of Cl￣content, hardness during September were higher than during August. 4. 29 sepecies of zooplankton and 82 species of phytoplankton were found in those 6 brackish lakes and so the total 111 species of plankton were confirmed. The dominant phytoplankton species were Lyngbya majuscula, Cocconeis placentula and Spyrogyra sp. and dominant zooplankton species were Sinbcalamus tenellus, Nauplius of Copepoda and Brachionus calyciflorus in those brackish lakes.

牙山人工湖의 理化學的水質調査

沈英燮,羅圭煥,洪思澳 成均館大學校 1978 論文集 Vol.25 No.-

The surface and bottom of the water quality in the Asan artificial reservoir have investigated in 6 sites according to the geographycal view points during 3 seasons, summer, autumn and winter. As compared the water quality of two areas near the dike with upper area at 4km distance from dike, it was not found any difference. Vertical variation of water quality was not found certainly difference between the surface and the bottom. Because the depth of this reservoir was no more than 3m, the water temperature was 1℃ high in the surface than bottom in summer, the conductivity increase 7.5μ? high in surface but in autumn and winter the conductivity increase in the bottom especially 12μ? and 13.2μ?. The another items of water quality didn't found any difference. According to the seasonal variation of water quality, the water temperature was 25.6℃ in summer, 17.4℃ in autumn and 4℃ in winter. The concentration of Cl^- was 26.6ppm in summer and gradually increase in autumn and winter especially 103.6ppm and 267.9ppm. The total hardness exhibit much the same tendency with Cl^- and most high in winter as 134.9 ppm. The content of K and Na was lower in summer but most high in winter especially 10.0 ppm and 159.3 ppm. The water quality of the Jin wi river which is one of the water source in this reservoir was severely polluted with industrial waste water. The content of total hardness 152ppm, conductivity 565μ?, the content of COD 6.7ppm, the content of Na 550ppm and the content of Fe 1.4ppm.

感潮河川水의 陸水學的 硏究 : 漢江下流 金浦大橋附近水域의 水質變動에 관하여 Variation of Water Qualities Near the Kimpo Bridge in the Down Area of Han River

洪思澳,羅圭煥,慶春浩 成均館大學校 1980 論文集 Vol.28 No.-

The variation of water qualities in Kimpo of Han river was surved according to the tidal change and also investigated seasonal and regional variation of water qualities in june on summer season and in cotober on autumn season during 1979. Between the surface and the bottom in this Kimpo of Han river the water qualities didn't found any significant difference and also didn't found any difference in periodically. Considering from the value of Cl^-, SO^-_4^2, Na and total hardness the water qualities in Kimpo of Han river may be influenced by a little of the tidal water. The content of nitrogen, Cl^-, phosphate as a pollutant was foung in autumn on dry seaon higher more than in summer on rainy season. Judging from the seasonal variation of water qualities it was more polluted in autumn on dry season than in summer on rainy season. Especially in the drying season on autumn it was considered to be influenced from the sewverly polluted waste water of Bulgwang river and Anyang river. Compared with the water qualities in each site which have deviced 3 sampling points site 1, 2 and 3. Site 1 is north side of this area in which the waste water of Bulgwang river flow down mainly, site 2 is middle of this ares and site 3 is south side in which the waste water of Anyang river flow down mainly. In generally, the water quslities of all those sampling sites were remarkably polluted and especially in site 3 under the influence of Anyang river was found severly pollution than in site 2. The plankton of saprobic species such as Oscillatoria sp., Vorticella sp., Spirogyra sp. and Mougeotia scalaria, which was indicated for the pollution were found much in this area. So it could recognized that the water quality of Kimpoin Han river were remarkably polluted. Also it found some brackish species of planktons such as Brachionus sp., Sinocalanus tenellus and Alona guttata in this area so it considered to be influenced more or less by tidal water.

Bis(tributyltin) oxide가 랫드의 면역 및 성호르몬 활성에 미치는 영향

최한영,나규환 한국환경위생학회 1999 한국환경보건학회지 Vol.25 No.3

The purpose of this study finds out the effect of red ginseng extract(1.0g/kg) on bis(tributyltin)oxide(TBTO) (10, 20 and 40 mg/kg) which poisons against some organs like thyroid gland, liver, kidney, testis, ovary. Serum immunity and sex hormone activity of rats are examinned by gastric tubing for 3 weeks. 1he weights of each organ in treated group were increased, especially liver in females and those of testis in males were signignificantly increased at 10, 20 and 40 mg/kg(p<0.05, P<0.0l). In group treated with TBTO(10, 20 and 40 mg/kg) for females, the serum IgG level was significantly reduced in comparsion with control group(P<0.05). The group of females which were poisonned by TBTO and rGe was significantly recovered in TBTO 10 mg/kg + rGe 1.0 g/kg and TBTO 20 mg/kg + rGe 1.0 g/kg. In case of sex hormone activity of each sex, the estradiol activity of females and testosterone activity of males were sigoignificantly decreased rather than the control group. And control group by bis(tributyltio)oxide and red ginseng extract is just increased estiradiol activity.

Are pet foods safe? From perspective of mycotoxins, preservatives and antioxidants

Kyu-hwan Hwang(Kyu-hwan Hwang),Hye-ra Kim(Hye-ra Kim),Yoon-hwa Choi(Yoon-hwa Choi),Doo-hwan Kim(Doo-hwan Kim),You-Jin Lee(You-Jin Lee),Dong-Hyuk Jeong(Dong-Hyuk Jeong) 한국예방수의학회 2023 예방수의학회지 Vol.47 No.2

The aim of this study was to determine the contamination of mycotoxins and the concentration of preservatives and antioxidants in commercial pet food. 106 pet foods were purchased from online in Korea. Mycotoxin analysis were performed using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) and preservatives and antioxidants were analyzed by high performance liquid chromatography (HPLC). The contamination of the mycotoxins in all samples was proved to comply with the Korea legislation with regards to animal feed, the analyses revealed presence of aflatoxins, ochratoxin A, zearalenone and fumonisins, with values below 1.6 ㎍/㎏, 12.1 ㎍/㎏, 478.5 ㎍/㎏ and 1873.5 ㎍/㎏, respectively. Furthermore, the simultaneous presences of different mycotoxins were observed in most of positive samples. The levels of dehydroacetic acid (DHA), sorbic acid (SA) and benzoic acid (BA) were, respectively, with values below 0.24 g/㎏, 4.82 g/㎏ and 6.35 g/㎏. The concentrations of butylated hydroxy anisole (BHA) and butylated hydroxy toluene (BHT) were demonstrated to be acceptable, with values below 0.04 g/㎏, and 0.02 g/㎏. This indicated the need for further investigation into the potential risk deriving from chronic exposure to low doses of mycotoxins. Additionally, a co-contamination of mycotoxins which interact in synergic manner are more concern. As DHA that not accepted was detected and very high levels of SA were identified in samples, an upper limit for preservatives in pet foods should be established in pet foods. BHA and BHT were detected within the recommended levels for antioxidant content, so these are considered as safe.

Clinical outcomes of gastric variceal obliteration using N-butyl-2-cyanoacrylate in patients with acute gastric variceal hemorrhage

( Chung Hwan Jun ),( Ka Rham Kim ),( Jae Hyun Yoon ),( Han Ra Koh ),( Won Suk Choi ),( Kyu Man Cho ),( Sung Uk Lim ),( Chang Hwan Park ),( Young Eun Joo ),( Hyun Soo Kim ),( Sung Kyu Choi ),( Jong Sun 대한내과학회 2014 The Korean Journal of Internal Medicine Vol.29 No.4

Background/Aims: To evaluate the long-term efficacy and safety of endoscopic injection of N-butyl-2-cyanoacrylate (NBC; Histoacryl) for treatment of bleeding gastric varices. Methods: We retrospectively analyzed the records of 455 patients with gastric variceal hemorrhage (GVH) who were consecutively treated with NBC from January 2004 to July 2013, with a mean follow-up period of 582 days. The patients` endoscopic findings, initial hemostasis, complications, rebleeding rates, and bleeding- related death rates were reviewed. Results: Hemostasis was achieved initially in 96.9% (441/455) of patients; rebleeding occurred in 35.2% (160/455), and the bleeding-related death rate was 6.8% (31/455) during follow-up. Complications included fever (6.8%), abdominal pain (3.7%), diarrhea (1.3%), spontaneous bacterial peritonitis (0.7%), bacteremia (0.4%), and embolism (0.2%). A red-color sign on concomitant esophageal varices (EVs) (p = 0.002) and previous history of variceal bleeding (p < 0.001) were significant risk factors for rebleeding within 1 year. The Child-Pugh score (p < 0.001), presence of hepatocellular carcinoma (p = 0.001), and failure of initial hemostasis (p < 0.001) were the risk factors most closely associated with bleeding-related death. Conclusions: This study provides a comprehensive overview of the outcomes and prognostic factors of patients with GVH. The results may help in the selection of effective treatment strategies for patients with GVH.

病院廢水의 特性과 處理에 關한 鼎究

羅圭煥(Kyu Hwan Ra),玉致相(Chi Sang ok) 한국환경보건학회 1984 한국환경보건학회지 Vol.10 No.1

The hospital wastewaters have to be so disposed as to prevent disease and to protect water resources from hazardous substances; disinfectants, medicines, and chemicals. Polyvinylpyrrolidone-iodine complex (po꺼done-iodine) is widely used in the hospital as one of disinfectants. πùs study was carried out to manifest the effect of disinfectants in growth of activated sludge in treatment of the hospital wastewater by the activated sludge process. The results are as follow. 1. An average water quality of the hospital wastewater showed 7.2 in pH, 3.2 ppm in 00, 293.3 ppm in SS, 96.0 ppm in 800, 151 .1 ppm in COO, 0.4 ppm in povidone-iodine, 0.5 ppm in phenols, 5.4 ppm in surfactants, 1.6 ppm in o-phosphate, 4.6 ppm in NH3 -N, 249 x 104 counts/l00 mQ in coliform group organisms, and 1,369 x 101 counts/mQ in general counts of bacteria. And wastewater amounts discharged per bed was ca1culated 70 Q/d/bed. 2. In batch culture activated sludge process, each of cresol and podone-iodine was not effected in less than 0.1 ppm concentration, but the more concentration, the more inhibit the growth rate of activated sludge. In the mixture of two disinfectants, the growth was more inhibited the effect of single disinfectants. So that this reaction is considered as addition effect of two disinfectants. 3. The removal rates of the disinfectants by continuous cu1ture activated sludge process were 77 .6% in 0.4 ppm povidone-iodine, and in 80D was 85.6%. 4. It is desirable that the hospital wastewater is planed in order to be discharged to two system separately, sewer from life system and wastewater from medica1 system. From those results, it has been conc1uded that the hospital wastewater has to be treated safely by the activated sludge process.

Oral Health in Western Pacific Region, Current States, Challenges and Way Forward

Lee, Kyu-Hwan Shin, Seung-Chul Lee, Mi-Ra Chang, Yeon-Soo 대한임상예방치과학회 2011 International Journal of Clinical Preventive Denti Vol.7 No.1

Objective: The purpose of the study is to show the such level of the states for oral health as mainly in DMFT index rate in 12 years old, dft index rate in 5 years old and the oral cancer rate, according to gender distribution, in each country, related with such influencing factors as the dental environments, socio-economical situation and the systemic evironments conditions, according to classify the GNP level of each nation, in order to suggest the proper public oral health programs to contribute to promote the oral health level, for each country. Methods: Data analysis study was done with the information from the data bank of WHO internet or intranet, mainly, for 5 categories as the oral health status, systemic conditions related with the oral health, socio-economical factors, the dental systems, and the Public Oral Health activities, in 18 countries of WP RO region. Results: DMFT was low in high income countries and increased in middle upper or lower middle income, otherwise low level again in low income countries. Each country has performed the eligible programs for oral health promotion, with the consideration of the socio-economical factors for each country, in order to promote the oral health level and to prevent the oral diseases. Conclusion: Oral health can be promoted effectively by establishing the proper policies and programs by a responsible organization in each country as well as to be suggested with the appropriate guide lines from WHO. So WPRO should recommend or suggest to each country for effective public oral health program, by establishing the eligible and professional oral health department in governmental organization.

쓰레기 매립지 침출수에 관한 연구

羅圭煥,李長勳 한국환경독성학회 1992 환경독성보건학회지 Vol.7 No.2

Physical compositions of solid waste in Wonju, shopping area were investigated with combustibles 78.13% (papers 35.89%, foods 14.41% etc.) incombustibles 21.87% (glass and ceramics 11.02%, metals 6.0% etc.) in 1991, solid waste in apartment area were investigated with combustibles 84.27% (foods 34.29%, papers 22.58% etc.), incombustibles 15.73% (glass and ceramics 8.77%, metals 4.85% etc.) and residence area were characterised with combustibles 70.37% (foods 33.55%, papers 10.53% etc.) and incombustibles 29.63% (ash of briquet 17.29%, glass and ceramics 7.49% etc.). Water qualities of a leachate from municipal landfill of Wonju city were analysed pH 8.0~8.4, total suspended solid 102~140 mg/1, CN^(-) 0.003~0.008 mg/1, N0₂-N 0.108~0. 294mg/l and phenols 0.46~1.12 mg/1. Volume of the leachate for 20% methemoglobin formation were 0.2~0.4 mg/ml in Octever, 0.3~0.4 ml/ml in December sampling, 0.2~0.3 ml/ml in St. 1 and 0.4 ml/ml in St. 3.