Quantitative comparison of mRNA expression of glucosyltransferase(GTF) between xylitol-resistant(X^(R)) and xylitol-sensitive(X^(s)) mutans streptococci

Kim, Chong-Chul,Lee, Mi-Na,Kim, Young-Jae,Lee, Sung-Hoon 大韓小兒齒科學會 2006 大韓小兒齒科學會誌 Vol.33 No.1

Since the long-term exposure of mutans streptococci to xylitol is known to select for xylitol-resistant(X^(R)) natural mutants, the occurrence and survival of such X^(R) strains were performed in batch culture methods. The aim of the study was to compare the differentiation and quantification of mRNA expression of the gtf genes of X^(R) and X^(S) mutans streptococci. Using a real-time reverse-transcription polymerase chain reaction, the expression of each gtf was determined. In X^(R) strains, the relative levels of transcription of gtfB and gtfC were decreased while that of gtfD was increased, suggesting the presence of independent promoters. It also suggested that mutation related to production of glucosyltransferase occurred under the exposure of xylitol could explain the caries-preventive mechanisms of xylitol. 자일리톨에 장기간 노출된 mutans streptococci는 자일리톨에 내성이 발현되어 자일리톨 내성균주가 생성된다고 알려져 있다. 본 연구의 목적은 mutans streptococci에서 자일리톨 내성균주와 감성균주의 gtf 유전자 발현량을 각각의 유전자별로 정량적으로 분석하고 비교하는 것이다. 실시간 역전사 중합효소연쇄반응법을 이용하여 각각의 gtf 발현을 조사한 결과 gtfD는 증가한 반면. gtfB와 gtfC는 감소하였는데 이는 각 유전자의 독립된 조절기전이 존재함을 보여주는 것이다. 또한 자일리톨에 노출된 mutans streptococci에서의 glucosyltransferase와 연관된 유전자변형이 자일리톨의 치아우식증 예방효과의 작용기전 중 하나임을 알 수 있었다.

Effects of Extrusion Conditions on Pasting Properties of Potato and Potato : Wheat Flour Mixture

Cha, Jae Yoon,Cho, Yong-Jin,Kim, Chong-Tai,Kim, Chul-Jin,Ng, P. K. W. 한국산업식품공학회 2003 산업 식품공학 Vol.7 No.2

The purpose of this study was to develop extrusion process of fresh potato and to study the effects of extrusion condition on the pasting properties of extruded potato products. The blend of pressed potato and wheat flour and pressed potatoes were extruded at different die exit temperatures (110-160℃) and screw speed of 100 rpm using a twin-screw extruder with conveying, high and low shear screw configuration. The viscosity-related parameters, such as peak viscosity, through, final viscosity, peak time, and pasting temperature of the feed materials and extruded products, were studied using a rapid visco analyzer (RVA). Their water solubility index (WSI) and water absorption index (WAI) were also studied. The peak viscosity, through, final viscosity, and peak time of pressed potato extrudates and potato-wheat flour mixture extrudates decreased as die exit temperature increased. The WSI and WAI of potato products increased as die exit temperature increased. When high shear screw configuration was used, the values of viscosity-related parameters were lower than those when low shear screw configuration was used. The potato-wheat flour mixture products obtained different degrees of depolymerization from fresh potatoes and wheat flour depending on die exit temperature and screw configuration.

수종 생약의 체내 산소 유리기의 동태에 미치는 영향

이종철,남성윤,정연봉 慶星大學校 1995 論文集 Vol.16 No.2

In this research, we examined the effect of Prunus mume and Loranthi ramulus on the active oxygen in CCI₄induced rats. In rat liver homogenate intoxicated with CCI₄(0.5ml/100g),BuOH fraction of Prunus mume and Loranthi ramulus showed a remarkable inhibition of the lipid peroxidation. And Prunus mume reduced the superoxide productivity by CCI₄about 30%, but the inhibition by Loranthi ramulus was small in contrast with Prunus mume. In the group of Prunus mume treatment, the contents of protein bound-SH, and glutathion and the activity of glutathion S-transferase was recovered to the normal level but the effect of the Loranthi ramulus was small in contrast with Prunus mume.

유도기 등가회로정수의 정밀산정

조용철,좌종근 濟州大學校 産業技術硏究所 1998 산업기술연구소논문집 Vol.9 No.1

This paper presents a new method to determine the T-type equivalent circuit parameters for steady state analysis of induction motors. To determine the parameters, four simultaneous equations are obtained from the T-type equivalent circuit conditions. The initial values for these equations are evaluated by the simplified equivalent circuits. and then the parameters are calculated by iterative computation. Test results are compared with the computed results of the conventional method and the proposed method to demonstrate the validity of the proposed method. And it is found that the latter method is more accurate than the former method.

염모제 사용에 의한 인체림프구의 DNA 손상 변화

김영철,심미자,권정숙 한국환경독성학회 2004 환경독성보건학회지 Vol.19 No.1

To ascertain the effects of hair dyeing application on the DNA damage in human lymphocytes, a mixture of permanent black colored hair dye with the same amount of oxidant containing 6% hydrogen peroxide was used. A hair dyeing with contacting the scalp(conventional dyeing) and a hair dyeing with 3 to 4mm away from the scalp(alternative dyeing) were applied to each 15 young healthy women. Blood was taken from the brachial vein at two sampling times, just before and 6 hours after the hair dyeing, and tail extent moment(TEM) and tail length(TL) were measured by using a comet assay. After dyeing, TL was significantly increased in both conventional dyeing group and alternative dyeing group compared with before dyeing as an average of 47% and 28%, respectively, and TL for conventional dyeing group was higher than alternative dyeing group as an average of 1.2 fold. After dyeing, TEM was significantly increased in both conventional dyeing group and alternative dyeing group compared with before dyeing as an average of 192% and 76% respectively, and TEM for conventional dyeing group was significantly higher than alternative dyeing group as an average of 1.7 fold. Therefore, alternative dyeing application was induced to lower lymphocyte DNA damage than conventional dyeing application, and TEM was appeared to be a more sensitive tool for the measurement of lymphocyte DNA damage than TL in this study.

영암댐의 어도를 이용하는 회유성 어류 자원의 계절적 변화 연구

오철웅,황종서,박경양,송태곤 木浦大學校 沿岸環境硏究所 1999 沿岸環境硏究 Vol.16 No.1

영암호 통선겸용 갑문식 어도에서 총 30회의 어류 조사 결과 줄공치, 웅어, 숭어, 빙어, 전어 등 총 25종이 출현하였다. 어도의 출현 종은 계절별로 종조성, 개체수, 생체량에 있어서 크게 변동하는 것을 보여 주었다. 월별 총출현 종수는 6월에 12종으로 가장 많은 종이 출현하였으며, 다음으로 7, 8, 9월에 11종, 10월에 10종이었으며, 11월에 6종, 4월과 5월에 각각 5종으로 가장 적은 종수의 출현하였다. 종다양도지수 또한 6월에 1.048로 가장 높았으며, 11월에 0.346으로 가장 낮게 나타났다. 출현종의 개체수는 봄철이후로 전반적인 감소 경향을 보여 주었으며, 주요 우점종의 전체 개체수는 줄공치, 웅어, 빙어, 숭어의 순으로 나타났다. 생체량도 개체수의 변화와 마찬가지로 봄철이후로 전반적인 감소 경향을 보여 주었으며, 주요 우점종에 대한 전체 비율를 보면 웅어, 줄공치, 빙어, 숭어의 순으로 나타났다. 이러한 영암호 통선겸용 갑문식 어도에서 어도 이용 생물의 종조성, 개체수 및 생체량의 뚜렷한 계절적인 변화 (temporal variation)를 관찰 할 수 있었다. 이러한 결과는 계절별로 다양한 종들이 그들의 생활사의 일부 기간에 어도를 효과적으로 이용하고 있다는 것을 반영해 주었다. 우점종의 한종인 줄공치의 체장빈도분포 분석결과 줄공치는 두개의 연급군으로 이루어져 있으며, 두번째 연급군이 탁월 연급군이었다. 가입은 주로 여름철 (8월과 9월)에 일어났다. 이러한 결과는 줄공치가 치어기부터 성어기까지 어도를 이용하고 있다는 것을 지적해 주고 있다. Investigations were made on the temporal changes in species composition and species diversity, number of individuals and biomass of fishes in the fish way constructed at Young-am Dam. During the sampling period total 25 species were observed. Of these, dominant species were Hemiramphus kurumaeus, Coilia ectenes, Mugil cephalus, and Hypomesus olidus. Number of species was the most numerous in June (12) and the least in April and May (5). Similar results were found in the species diversity index (H'), which was 1.048 in June and 0.346 in November. There were variations in number of Individuals and biomass of fishes in the fish way, showing a gradual decline from summer to Autumn. This suggests that a variety of adult and larval fishes utilized in the fish way as a channel of migration in relation to their life history. Number of individuals (percentage of total number) was in the order of Hemiramphus kurumaeus (63%), Coilia ectenes (17%), Hypomesus olidus (15%), Mugil cephalus (5%) and biomass (percentage of total biomass) in the order of Coilia ectenes (51%), Hemiramphus kurumaeus (35%), Hypomesus olidus (7%), Mugil cephalus (4%). For one of the dominant species, Hemiramphus kurumaeus, length-frequency distribution showed that it consisted of two cohorts, with predominance in the 2nd cohort and recruitment occurred mainly in August and September, indicating utilization of fish way at various stages during its life history.

효소처리 찹쌀 전분의 이화학적 성질 및 유과제조 특성

유철,김종태,허남윤,김동섭,백무열 경희대학교식량자원개발연구소 2007 硏究論文集 Vol.26 No.1

유과 제조 시 제조 시간을 단축할 수 있는 소재를 개발하기 위하여 찹쌀 전분을 4가지 상업용 α-amylase 효소와 반응시켜 효소처리 찹쌀 전분을 제조하고 이들의 이화학적 특성을 연구하였다. 효소처리 찹쌀 전분의 팽윤력 및 용해도는 일반 찹쌀 전분에 비해 많이 증가되는 경향을 보였다. 등온흡습곡선에서는 효소처리에 따른 유의적인 차이는 나타나지 않았다. RVA특성을 검토한 결과 최대 점도, holding strength, final viscosity, break down, setback은 일반 찹쌀 전분보다 낮아지는 결과를 나타냈다. 열적특성에서는 아밀로펙틴 용해 개시온도, 아밀로펙틴 용해 종결온도 그리고 아밀로펙틴 용해 온도범위(△T)는 각 전분간에 유의적인 차이가 나타나지 않았으며 아밀로펙틴 용해 엔탈피 역시 유의적인 차이를 나타내지 않았다. X-ray 회절 분석 결과로 볼 때, 효소처리 찹쌀 전분 및 일반 찹쌀 전분 모두 A형의 결정 형태를 나타내었고, 상대적 결정화도의 차이가 나타나지 않는 것으로 보아 효소처리가 찹쌀 전분의 결정형영역에는 영향을 주지 않는 것으로 보여진다. 효소처리 찹쌀 전분을 사용하여 제조한 유과의 경우 과도한 점도손실에 의해 반죽을 제조하지 못하여 본 연구에서 사용한 효소치리 정도가 부적합한 것으로 판단되었다. Physicochemical properties of partially hydrolyzed waxy rice starches with various α-amylases were investigated to reduce processing-time of yukwa (Korean traditional puffed rice snack). Four commercial α-amylases (Fungamyl, Termamyl, Liquozyme, Kleis tase) were used in this work. Waxy rice starches (20% solid content) were treated with same unit of four α-amylases at 40℃ and pH 6.0 for 1 hour. Partially hydrolyzed waxy rice starches showed higher swelling power and solubility than native waxy rice starch. Pasting temperature and peak viscosity of partially hydrolyzed waxy rice starches were lower than those of native starch. DSC thermal transitions of partially hydrolyzed waxy rice starches shifted to higher temperature than native waxy rice starch possibly due to hydrolysis of amorphous region and some double helical structure. X-ray diffraction patterns of both native and partially hydrolyzed waxy rice starches were typical A-type pattern indicating that alpha-amylase cannot disrupt the crystalline structure in this condition.

유치열기 아동의 한국어 모음 발음에 관한 음향음성학적 연구

김종철,최종학 大韓小兒齒科學會 1994 大韓小兒齒科學會誌 Vol.21 No.1

The purpose of this work was to analysis the formants of korean vowel sounds and to study the sounds change due to variables(age, sex, occlusion, facial type, platal vault, overbite, overjet, arch form, and crowding or spacing of ant. teeth) in the primary dentition. For this study, 91 healthy children(42 males and 49 females) in the primary dentition were selected. Their ages ranged from 52mons.to 74 mons, the mean age was 66.32mon. (S.D.4.44mons). The 8 Korean vowels were recorded and analyzed using Sensimetrics speech station(Version 2.1). The parameters used in analysis were formants of the vowel sounds and variables. The results were as follows: 1. Each vowel sounds have specific formants ranges independently(p<0.05). 2. /ㅏ[a], ㅔ[e],ㅣ[I]/’s formants was affected by sex. The female’s formants of the vowel sounds is higher than male’s. 3. Vowel sound was significantly affected by variables./ㅐ[ε]/´s formants was affected by overbite./ㅏ[a]´/s formants was affected by sex, arch form, age, and overbite./ㅓ[??]´s formants was affected by sex and crowding or spacing of ant. teeth. /ㅔ[e]/´s formants was affected by overbite, crowding or spacing of ant. teeth, and facial pattern. /ㅗ[o]/’s formants was affected by Angle´s occlusion./ㅜ[u]/´ formants was affected by facial pattern. /ㅣ[i]´s/ formants was affected by age, crowding or spacing of ant. teeth, facial pattern and sex. /ㅡ[??]/´s formants was affected by arch form. 4. There were significant differences in some vowel sound according to each Variables(p<0.05). Significant differences according to Age were seen the first formants of /ㅐ[ε]/. Significant differences according to Angle´s classification of occlusion were seen the 2nd and 3rd formants of /ㅔ[e]/. Significant differences according to facial pattern were seen the 2nd formant of/ㅔ[e]/. Significant differences according to crowding or spacing of ant. teeth were seen the 2nd formant of /ㅏ〔a], ㅔ[e]/, the 3rd formant of /ㅓ[??]/. Significant differences according to arch form were seen the 2nd and 3rd formant of/ㅏ[a]/.

방사선 에너지 분석을 위한 MCA시스템 제작에 관한 연구

육종철,오병훈,김영균 대한방사선 방어학회 1987 방사선방어학회지 Vol.12 No.1

SA(Successive Approximation)형 ADC(Analog to Digital Converter)를 사용하여 방사선다중채널파고 분석기를 설계 제작하였다. 선형게이트, 윈도우 펄스스트레처는 논리 IC와 선형 IC들을 위주로 결합하여 구성하였으며, 분석시간이 120㎲ec인 ADC 1211(12bit)을 중심으로 한 ADC모듈의 메모리로는 S-RAM 6264(Address 13bit, Data 8 bit) 2개를 병렬로 연결하여 사용하였다. 마이크로 컴퓨터 (Apple II)가 전체 시스템을 제어하고 또 계측된 결과의 데이터를 분석할 수 있도록 인터페이스와 소프트 웨어도 만들었다. 제작된 시스템의 동작시험은 표준펄스 발생기로 0∼10V 사이의 일정한 펄스를 만들어 시스템에 입력시켜 그 펄스들을 계측하게 하고, 계측이 끝난 후 컴퓨터가 그 결과를 받아들여 분석하게 함으로써 이루어졌다. A basic multichannel analyzer (MCA) system have been designed and constructed with the successive approximation type ADC (Analog to Digital Converter). Linear Gate, window, and palse stretcher consist of mainly linear and logic IC's, and are properly combined together to achieve short dead time and good linearity of the system. ADC 1211 (analyzing time : 120㎲ec) and S-RAM (static random access memory) 6264 are used in ADC module. Two 6264 memories are connected in parallel in order to provide enough counting capacity (??-1). Interfaced microcomputer Apple II controls this system and analizes the counted data. The system is tested by input pulses between 0V to 10V from oscillator.

MEAW를 이용한 Angel씨 제III급 부정교합자의 치험례

김종철,최종학 大韓小兒齒科學會 1992 大韓小兒齒科學會誌 Vol.19 No.2

Class Ⅲ malocclusion is more common problem in the Oriental. Their chief complaints are mandibular prognathism, deficient mastication, and esthetic problem. Early C1 Ⅲ malocclusion treatment is necessary for normal function reconstruction. This report presents a case with mandibular prognathism that was treated by means of Fixed edgewise appliance and MEAW mechanics. Class Ⅲ MEAS mechanics is composed of upper ideal archwire, lower multiloop archwire(MEAW), and intermaxillary elastics. After 10 months active treatment, a good ClassⅠmolar relationship was obtained.