급성하벽심근경색에서 전흉부유도 ST절 하강의 의의

정병천,배호상,곽동훈,김영태,배용학,황종현,임현주,류재근,조용근,채성철,전재은,박의현 慶北大學校 醫科大學 1997 慶北醫大誌 Vol.38 No.2

목적 : 급성하벽심근경색증 환자에서 심전도상 흔히 동반되는 전흉부유도 ST절 하강의 의의를 알아보았다. 방법 : 심근경색후 24시간에서 48시간에 얻은 심전도를 기준으로 52명의 급성하벽심근경색증 환자를 전흉부유도에서 ST절의 하강이 있는 군과 없는 군으로 나누었으며 심도자, 관상동맥조영술, 심초음파도 및 방사성 핵종을 이용한 좌심구혈율 측정 등을 시행하였다. 결과 : 1) 좌심실확장기말압은 전흉부유도에서 ST절의 하강이 있는 경우에서 16.9±5.33mmHg로 없는 경우의 11.0±4.02mmHg보다 유의하게 높았다(p<0.05). 그러나 운동량 및 좌심구혈을은 흥부 유도상 ST절의 하강이 있는 경우 7.6±3.0 METs 및 53.9±9.1%로 없는 경우의 9.1±2.7 METs 및 54.6±9.5%보다 낮았으나 통계적 유의성은 없었다(p=0.180, p=0.823). 2) 관상동맥조영술상 전흉부 ST절의 하강이 동반된 군에서는 유의한 좌전하행지나 좌회선지의 협착이 있는 경우가 60.9% 및 57.9%로 ST절의 하강이 없는 군에서의 34.5% 및 7.7%와 비교해 좌관상동맥에 협착이 동반된 경우가 많았다(p=0.050, p=0.001). 3) 관상동맥조영술상 세 혈관질환의 빈도는 흉부유도상 ST절의 하강을 보인 23예에서 10예로 ST절 하강이 없었던 29예중 2예에 비하여 유의하게 많았고(P=0.007), 단 혈관질환의 빈도는 ST절의 하강을 보인 군에서 23예중 5예로 ST절 하강이 없었던 29예중 17예에 비하여 유의하게 적었다(P=0.002). 두 혈관질환의 경우에는 각각 8예와 10예로 양군간에 유의한 차이가 없었다. 4) 흉부유도상 ST절 하강의 빈도는 단 혈관질환 22예 중 5예에서, 두 혈관질환 18예중 8예, 세 혈관질환 12예 중 10예에서 관찰되어 협착이 있는 관상동맥의 수가 많을수록 ST절의 하강이 나타나는 빈도가 많음을 보였다(p=0.00308). 그러나 흉부유도상 나타난 ST절의 하강을 모두 합하여 구한 ST절 하강의 합은 협착이 있는 관상동맥의 수와 통계적인 유의성이 없었다. 5) 심초음파도상 좌심실 하벽의 벽운동은 ST절 하강을 보인 군에서는 akinesia가 83.3%, hypokinesia가 11.1%, 정상 벽운동이 5.6%로, ST절 하강이 없었던 군에서의 dyskinesia가 3.6%, akinesia가 39.3%, hypokinesia가 25.0%, 정상 벽운동이 32.1%와 비교하여 ST절의 하강이 있는 군에서 유의하게 벽운동의 장애가 빈번함을 보였다(p=0.03891). 그러나 좌심실전벽, 측벽 및 중격부위에서는 유의한 벽운동의 차이가 없었다. 결론 : 급성하벽심근경색증 환자의 전흉부유도에서 ST절의 하강이 동반되는 경우 다혈관 질환의 가능성이 높으며 좌심실확장기말압이 상승되었고 운동능력은 감소되어 있었다. 또한 심초음파도상 좌심실하벽의 벽운동장애도 심하였다. 따라서 전흉부 ST절의 하강을 동반한 급성하벽심근경색증 환자는 전흉부유도에 ST절 하강이 없는 경우보다 예후가 불량할 것으로 생각되며, 보다 적극적인 치료가 필요할 것으로 생각된다. The purpose of this study was to determine the significance of precordial ST segment depression appearing during acute inferior myocardial infarction and to assess the correlation of that with angiographic finding. 52 patients were allocated into two groups based on the existence of precordial ST segment depression : 23 patients with ST segment depression and 29 patients without ST segment depression. The extent of coronary artery disease as well as the prevalence of significant stenosis (≥70%) in left anterior descending artery were more frequent in patients showing precordial ST segment depression than in patients not showing them (p=0.050) and the result were similar in cases of left circumplex artery (p=0.001). On echocrdiographic examination of left ventricular (LV) wall motion, it showed more severely decreased inferior LV wall motion in patients showing precordial ST segment depression than in patients not showing them (p=0.03891) even though the other segment of LV wall motion didn't show the statistical difference between both groups. The other cardiac parameters such as LVEDP, exercise amount (METs) and ejection fraction were tend to showing bad profile in patients with precordial ST segment depression. From the above results, we could deduce that patients with precordial ST segment depression have relatively large infarction or concomitant left coronary artery disease, so they need more caution and intensive theraphy.

서울의 Penicillinase Producing Neisseria gonorrhoeae 발생빈도(1998)

김재홍,김준호,반재용,이정우,황성주,정준규,정성태,강진문,조흔정,홍창의,정혜신,이한승,김이선,이봉길,이종호,선영우,한기덕,윤성필,이성훈,안종성,박석범,문승현,조항래,김형섭,류지호,황재영,박준홍,손상욱 한양대학교 의과대학 2001 한양의대 학술지 Vol.21 No.1

In recent years, gonorrhea has been pandemic and remains one of the most common STDs in the world, especially in developing countries. For the detection of a more effective therapeutic regimen and assessing the prevalence of Penicillinase Producing Neisseria gonorrhoeae(PPNG), we have been trying to study the patients who have visited the Venereal Disease Clinic of Choong-Ku Public Health Center in Seoul since 1980 by menas of the chromogenic cephalosporin method. In 1998, 93 strians of N. genorrhoeae were isolated, among which 60(64.5%) were PPNG. The prevalence of PPNG in Seoul, which had been decreased to 39% in 1996 after a peak of 74.3% in 1993, is increased to 64.5% in 1998.

소아과 입원 환자에 대한 통계적 고찰

정용현,서우식,유재홍,변상현 충남대학교 의과대학 지역사회의학연구소 1995 충남의대잡지 Vol.22 No.2

For the purpose of assessing the disease patterns by the body organ system in patients of the pediatric age, we performed a statistical analysis of diseases of patients admitted to the department of pediatrics at Chungnam National University Hospital from January 1990 to December 1994. The results obtained were as follows : 1. Total numbers of in-patients were 8,007, of which 4,923 were male and 3,084 were female. The ratio male to female was 1.60 : 1. 2. Prevalence of the diseases classified by body organ system was in the following order : neonatal diseases (34.6%), respiratory diseases (17.4%), infectious diseases (11.5%), congenital anomalies (5.5%), digestive diseases (5.1%), genitourinary diseases (4.9%), neoplasm (4.7%), blood diseases (3.3%), nervous system diseases (2.8%), metabolic and endocrine diseases (2.4%), circulatory system diseases (2.3%), skin and subcutaneous diseases (1.3%), musculoskeletal and connective tissue diseases (1.2%), mental and behavior disorders (0.4%). 3. Major diseases in each body organ system were as follows : 1) infectious diseases : unspecified acute gastroenteritis (35.9%), viral meningitis (10.4%), Rotaviral enteritis (6.8%), sepsis (6.7%), measles (5.8%). 2) neoplasm ; ALL (34.1%), AML (15.8%), Wilms tumor (12.8%), NHL (8.2%), neuroblastoma (5.6%) 3) blood diseases : allergic purpura (24.2%), aplastic anemia (17.1%), ITP (16.4%), iron deficiency anemia (15.8%). 4) metabolic and endocrine diseases : short stature (22.0%), hypocalcemia (13.8%), metabolic acidosis (9.6%), IDDM (6.4%). 5) mental and behavior diseases : neurosis (47.7%), mental retardation (18.2%). 6) Nervous and sensory system diseases : epilepsy (43.2%), cerebral palsy (12.1%), otitis media (9.3%), encephalopathy (6.2%). 7) circulatory system diseases: congestive heart failure (29.2%), dilated cardiomyopathy (8.0%), rheumatic fever (8.0%), mitral insufficiency (6.8%), hypertension (6.4%). 8) respiratory diseases : pneumonia (40.1%), URI (9.6%), acute tonsillitis (9.4%), asthma (8.5%), acute bronchiolitis (8.3%), croup (7.1%), acute bronchitis (4.1%). 9) digestive system diseases : unspecified hepatitis (22.8%), acute gastritis (13.8%). CAH (12.6%), intussusception (7.8%), constipation (7.1%). 10) skin and subcutaneous diseases : cellulitis (23.1%), lymphadenitis (19.7%), urticaria (15.6%), atopic dermatitis (8.8%), furuncle (8.2%). 11) musculoskeletal and connective tissue diseases : Kawasaki disease (76.8%), JRA (8.5%), SLE (7.0%). 12) genitourinary system diseases : UTI (29.0%), minimal change nephrotic syndrome (27.3%), APSGN (7.6%), APN (4.9%). 13) congenital or chromosomal abnormalities : VSD (38.7%), ASD (10.5%), TOF (8.4%), PDA (5.2%), CHPS (4.5%), Down syndrome (4.1%). 14) neonatal diseases : jaundice (32.0%), prematurity (12.7%), RDS (5.7%), sepsis (4.5%), birth asphyxia (3.0%), SGA (3.0%). 15) Others : febrile convulsion (45.6%), failure to thrive (9.2%), FUO (8.9%), drug intoxication (8.2%). 4. Common diseases for admission in pediatrics were in the following order : jaundice, pneumonia, unspecified acute gastroenteritis, VSD, RDS, URI, acute tonsillitis, acute lymphadenitis, ALL, sepsis, asthma, acute bronchiolitis, UTI.

페니실린 내성 폐렴구균 균혈증의 임상적 특성

정두련,송재훈,김은옥,류지소,이남용,이혁,백경란,김성민,배직현,우준희,김양수 대한감염학회 1997 감염 Vol.29 No.4

목적: 지역사회 획득 감염의 매우 흔한 원인균인 폐렴구균의 페니실린 및 다른 항균제에 대한 내성의 증가는 세계적으로 문제가 될 뿐 아니라 국내에서 더욱 큰 문제로 대두되고 있다. 본 연구는 항균제 내성 여부에 따른 폐렴구균 균혈증의 임상적 특성 및 위험 요인를 분석하여 항균제 내성의 임상적 의미를 조사하고자 시행되었다. 방법:1989년부터 1994년까지의 폐렴구균 균혈증 41례를 대상으로 하여 의무기록지를 조사하였다. 균주의 항균제 감수성 검사는 oxacillin 디스크 확산법으로 페니실린 내성 여부를 거사한 후, 한천 희석법을 이용하여 페니실린을 비롯한 11개의 항균제의 MIC (minimal inhibitory concentration)를 구하고 감수성 여부를 판정하였다. 결과: 41균주 중 68.3%가 페니실린에 대하여 내성(중등도 12.2%, 고도 56.1%)을 보였으며 다제내성률은 61%였다. 특히 소아에서는 100%(고도 88.2%)의 내성률을 보여 성인보다 내성률이 더 높았다. 페니실린 내성 균주는 대부분 다른 β-lactam 항균제에도 내성을 보였으며 특히 페니실린 고도 내성 균주는 cefotaxime, ceftriaxone에 대하여 100% 내성을 보였고 imipenem에 대해서도 95.5%의 중등도 내성률을 보였다. 혈청형은 19와 23이 많았고 그 외에 6이 있었다. 임상적 특성의 분석상 환자들의 연령분포는 3개월부터 82세까지였으며 기저질환을 가지고 있는 환자가 56%이었으며 지역사회 획득 감염이 71%였다. 균혈증의 일차감염원은 폐렴(22례, 54%)과 수막염(5례, 12%)이 가장 많았다. 페니실린 내성의 위험요인으로는 소아 연령만이 유의한 요인으로 분석되었다. 항균요법에 대한 반응을 볼 때 실패한 경우는 고도 내성 군의 20%에서만 있었으며 병원내 총사망률은 페니실린 감수성 군이 30%, 중등도 내성 군이 20%, 고도 내성 군이 13.6%로서 유의한 차이는 없었다. 결론: 페니실린 내성 폐렴구균은 국내에 만연하고 있으며 높은 다제내성률을 보였다. 이들은 대개 지역 사회 획득 감염을 일으키는데 균혈증의 경우 그 사망률은 내성 여부에 따른 차이를 보이지 않았다. 소아연령만이 페니실린 내성의 위험요인으로 분석되었다. Background: The emergence of penicillin-resistant Streptococcus pneumoniae (PRSP) poses serious therapeutic problem in clinical practice, especially in cases with bacteremia or meningitis. Methods: To investigate clinical characteristics of bacteremic pneumococcal diseases due to PRSP, we retrospectively analyzed 41 cases with cocumented bacteremic diseases seen in a tertiary care hospital between 1989 and 1994. Results: Agar dilution test of 41 strains isolated showed that 68.3% of S. pneumoniae were PRSP [high-level resistance(R) 56.1%, intermediate resistance(I) 12.2%]. High-level resistant strains were not susceptible to other β-lactam agents, whereas isolates of penicillin-susceptible S. pneumoniae(PSSP) were uniformly susceptible to all β-lactam agents. Predominant serogroups of PRSP were 19, 23, and 6. Bacteremic diseases caused by PRSP included pneumonia (22), meningitis (5), peritonitis (3), acute otitis media (2), acute tonsillitis (2), endocarditis (1), pyelonephritis(1), and primary bacteremia(5). Children were more likely to be infected with PRSP with high-level or intermediately resistant strains than were adults(P=0.0001), but no differences were seen between PRSP and PSSP regarding sex. previous antibiotic history, previous hospitalization, and underlying immunocompromised conditions. Most cases were community-acquired (R 78.3%, I 60%, S 61.5%). Fatality rates of patients infected with PRSP were not different significantly from PSSP (22.6% vs. 30%). However, most fatal cases had underlying immunocompromised conditions. Conclusion: PRSP is widely prevalent in Korea and shows resistance to most antibiotics. It causes community-acquired bacteremic diseases with poor outcomes, but there was no difference in mortality between patients infected with PRSP and PSSP. Pediatric age was the only risk factor for penicillin resistance.

7개 대학 병원에서 조사한 지역사회 폐렴의 원인균

정문현,김성민,강문원,최희정,정희진,이경원,한성우,송재훈,신형식,김의종,최강원,김민자,박승철,배현주,정윤섭,김준명,백경란,신완식,이규만,김양리 대한감염학회 1997 감염 Vol.29 No.5

목 적 : 폐렴은 많이 발생하면서 사망률이 크게 줄지 않는 질환이며, 이를 적절히 치료하기 위해서는 원인균의 상대적 빈도, 기저 질환에 따른 변화, 항균제 내성률, 사망에 관련된 인자들을 알아야 한다. 원인균의 빈도는 지역마다 차이가 있고 국내에서는 항균제 내성률이 높아 지역사회에서 발생한 폐렴을 치료하기 위한 경험적 항균제 선택에 도움이 되기 위해 서울 소재 6개 대학 병원과 천안의 1개 대학 병원이 참여하여 위의 사항들에 대해 조사를 하였다. 방 법 : 1995년에 내과에 입원했던 16세 이상 환자를 대상으로 했다. 퇴원 진단명이 폐렴 또는 폐결핵인 병록지을 찾았고, 이중에서 병원 감염을 제외하였다. 특이도를 높이기 위해, 이들 중에서 호흡기 증상이 있고 발열이나 저체온이 있으면서 흉부 X-선에서 이상 음영이 있는 환자만을 대상으로 했다. 폐결핵은 위의 기준에 입원 초기에 항균제 치료를 하고 입원 7일 이후에야 항결핵제가 투여된 경우만을 폐렴의 원인균으로 하였다. 혈액 배양에서 양성, 객담에서 항상균이나 M. tuberculosis가 증명된 경우, 혈청학적으로 항체가가 4배 이상 증가된 경우, 조직에서 원인균이 진단된 경우는 확정(definitive) 원인균으로 하였고, 객담에서 배양된 균이 그람 도말과 일치할때, 항결액제에 대한 반응으로 진단한 폐결핵, 단일 항체가 양성이고 이에 대해 항균제를 사용했을 때는 가능(probable) 원인균으로 정의하였다. 다세균 감염균은 각각 다 른 원인균으로 처리하였다. 임상 조사와 함께 임상병리과에서 S. pneumoniae, H. influenzae, M. catarrhalis, mycoplasma, 항상균에 대해 검사 의뢰 건수, 배양 양성수, 항균제 감수성 결과를 조사하였다. 결 과 : 폐렴의 증례 정의에 부합하지 않은 135명과 폐결핵의 정의에 해당하지 않는 230명을 제외하고 남은 246명의 평균 나이는 58.2세이고 남성이 142명(58.2%) 이었고, 71%의 환자에서 기저 질환이 있었다. 진단 방법의 시행 횟수는 혈액 배양 77.6%, 혈청 검사 18.3%, 기관지경 검사는 4.1%였고, 세균의 항원 검사를 한 예는 없었다. 원인균이 밝혀진 예는 77명(31.3%)이었다. 다세균 감염이 4명에서 있었고, 원인균의 상대적 빈도는 결핵 20명(확정 17, 가능 3: 6개 병원 자료), 폐렴구균 18(확정8 가능 10)명과 폐렴구균이 아닌 Streptococcus 3명 (모두 확정), H. influenzae 11명(모두 가능), 그람음성간균 11명(확정 7, 가능 4) (K. pneumoniae 8건), Mycoplasma 5명(확정 1, 가능 4), S. aureus 4명(확정 2, 가능 2), mucormycosis 1명(확정)이었다. 평균 입원 기간은 19일이고, 중환자실 입원률과 인공 호흡기 사용율은 각각 18%와 9.3%였다. 사망률은 13.8%였고 사망까지 평균 기간은 14.6일 이었다. 다변량 분석에서 사망을 예측할 수 있는 인자는 저체온과 빈호흡이었다. 임상병리과에서 배양되었던 모든 폐렴구균의 Penicillin 내성률은 서울 3개 병원에서 82-88%, 천안에서 72%였다. 폐렴 환자의 혈액에서 배양된 7주는 모두 Penicillin에 감수성이 있었다. K. pneumoniae 8주 모두 cefotaxime과 gentamicin에 감수성을 보였다. 결 론 : 후향적 조사이고 병원마다 원인균 진단에 차이가 있지만, 원인이 밝혀진 경우에는 결핵과 폐렴균이 흔하였고, 무균 부위에서 배양된 폐렴구균의 항균제 내성률은 낮았다. 원인이 밝혀지지 않은 경우가 많고, 혈청검사로 진단되는 원인균이 드물며, 분리균주가 적어 항균제 내성 정도를 추정하기 어려워, 이를 밝히기 위한 전향적 조사가 필요하다. Background : Community-acquired pneumonia (CAP) is one of the leading causes of mortality and morbidity, but its management is still challenging. The limitation of diagnostic methods to identify etiologic agents rapidly make it necessary to use empiric antibiotics in almost all patients, and furthermore the discovery of new respiratory pathogens and the emergence of antibiotic-resistant organisms pose difficulties to the selection of an empiric regimen. To clarify the factors necessary for the optimal choice of empirical antibiotics, such as the frequency of etiologic agents, the attributable rates to death and antimicrobial resistance rates in the community, six university hospitals in Seoul and one university hospital in Cheonan were participating in this study. Methods : medical records of adults (>15 years of age) hospitalized for CAP or pulmonary tuberculosis between April 1995 and March 1996, were reviewed. Patients who satisfied all of the following criteria were included in the study: (1) fever or hypothermia; (2) respiratory symptoms; and (3) pulmonary infiltrates on chest roentgenogram. To exclude cases of pulmonary tuberculosis whose roentgenographic features were so typical that it could be easily differentiated from conventional pneumonia, two additional criteria were required for inclusion: antibiotic treatment during the first week of hospital admission and initiation of anti-tuberculosis medications thereafter. Organisms isolated from sterile body sites, acid-fast bacilli or Mycobacterium tuberculosis isolated from sputum, pathogens diagnosed by a 4-fold rising titer of antibodies to “atypical”pathogens, or pathogens revealed by histopathology were defined as definitive cause of pneumonia; isolates from sputum withcompatible Gram stain, pathogens diagnosed by a single diagnostic titer plus use of a specific antimicrobial agent, or tuberculosis diagnosed by clinucal response to anti- tuberculosis medications were considered probable cause of pneumonia. The records of the clinical microbiology were reviewed for isolates of S. pneumoniae, H. influenzae, M. catarrhalis, Mycobacterium or acid-fast bacilli, and Mycoplasma. Then the frequency of these agents, antimicrobial resistance rates of resiratory pathogens from all body sites, and their clinical significance were evaluated. Results: After excluding 365 patients (230 with pulmonary tuberculosis and 135 with CAP) who were screened for inclusion but did not meet the inclusion criteria,246 persons were enrolled in this study. Their mean age was 58.2 years old with slight male predominance (58.2%), and 171(71%) patients had underlying illnesses. Blood cultures were performed on 191 (77.6%) patients and serologic tests on 44(18.3%) patients. The etiologic agents were identified in 31.3%, and the list of individual agents, in decreasing order, was pulmonary tuberculosis (17 definite and 3 probable: data of six hospitals), S. pneumoniae (8 definite and 10 probable), non-pneumococci (3 definite), aerobic gram-negative bacilli (7 definite and 4 probable), Haemophilus spp. (11 probable), mycoplasma (1 definite and 4 probable), polymicrobial infections (2 definite and 2 probable: E. coli and S. agalactiae, M. tuberculosis and S. aureus, S. pneumoniae and H. influenzae and A. baumannii and K. pneumonias), S. aureus (2 definite and 2 probable) , and mucormycosis (1 definite). Among gram-negative bacilli, K. pneumoniae was the most common agent (8isolates). therates of admission to the intensive care unitand of using assisted ventilation were 18% and 9.3%, respectively. The mortality was 13.8% and logistic regression analysis showed that hypothermia and tachypnea were associated with death. Hospital stay averaged 19 days. Susceptible rates of S. pneumoniae isolated from all body sites to penicillin ranged from 8% to 28% but seven isolated from blood of patients with pneumonia were susceptible to penicillin. Also all 8 isolated of k> pneumoniae from patients with pneumonia were susceptible to cefotaxime and gentamicin. Conclusion: In Korea, in addition to S. pneumoniae, M. tuberculosis is an important agent causing community-acquired pneumonia. The low incidence of etiologic diagnosis is probably related to infrequent requesting of test "atypical" pathogens and does not represent the true incidence of infections by "atypical" pathogens, which well be answered by a prospective study. The antimicrobial resistance rates of major respiratory pathogens from sterile body sites are low, however, because of a small number of the isolates this result needs confirmation by a nationwide surveillance of antimicrobial resistance.

복강경을 이용한 대장 부분 절제 시행 1예

박재갑,서경석,정회원,김선회,오용석,송인성,박용현 대한대장항문학회 1993 Annals of Coloproctolgy Vol.9 No.1

Protein Methylase Ⅱ에 依한 Carboxylmethylation이 胎盤組織 Na^+, K^+―ATPase 活性에 미치는 影響

鄭顯,林圭,黃炳斗,李載欣 충남대학교 의과대학 지역사회의학연구소 1987 충남의대잡지 Vol.14 No.2

Partial purified human placental Na+, K+-ATPase and plasma membrane proteins were enzymically carboxylmethylated by human placental protein methylase II, and changes in their Na^+, K^+-ATPase acivities were studied. 1.. The rates of enzymatic carboxylmethylation by protein methylase II of the placental Na^+, K^+-ATPase fraction, which had been purified 19-fold, and of the plasma membrane proteins were 0.71 and 0.50 pmoles/mg protein/minute, respectively, when measured by the incorporation of ^3H-methyl group from S-adenosylmethionine into the proteins. 2. The enzymatic carboxylmethylation was found to be a function of the concentration of S-adenosylmethionine as well as of the substrates and incubation time. 3. More than 60% of the carboxylmethylated Na^+, K^+-ATPase fraction and plasma membranes were demethylated during 30 minutes incubation at pH 7.4, with the demethylation half time of 15 and 8 minutes, respectively. 4. The placental Na^+, K^+-ATPase fraction and plasma membrane proteins were found to be better substrates for protein methylase II than histone IIA. 5. Polyacrylamide gel electrophoresis of the carboxylmethylated plasma membrane proteins and Na^+, K^+-ATPase fraction showed multiple carboxylmethylated subfractions: in the plasma membrane, subfractions of molecular weight 95000, 43,000, 26,000 and less than 20,000, among which molecular weight 26,000 fraction was most strongly carboxylmethylated, and in the Na^+, K^+-ATPase fraction, subfractions of molecular weight 50,000, 40,000, 26,000, and less than 20,000 were carboxylmethylated. 6. Na^+, K^+-ATPase activities of the plasma membrane and the Na^+, K^+-ATPase fraction were increased by 36% and 9% when carboxylmethylated, and decreased by 25% and 21% after cAMP-dependent phosphorylation, respectively. These results suggest that protein merhylase II may have some indirect role in the regulation of Na+, K+-ATPase activity.

진화 알고리듬을 위한 객체지향 모델링과 클래스 라이브러리 구현

정호연,이수연,곽재승,김용주,박기태,현철주 한국경영과학회 2000 經營 科學 Vol.17 No.2

In evolutionary algorithm, there exist various models for the evolution of the population with respect to schemes and strategies for reproduction, in the application of the algorithm to a specific problem, one model suitable to the problem is to be properly chosen and a program expert or a software is needed to help implement and test a designed algorithm. In this study, object oriented modeling and the class library for simple evolutionary algorithms(SEA) with one population is developed. The library proposed here can be used as a generalized tool for solving problems in a wide range of domains.

대구지하철 역세권의 공간이용특성 및 개발방향연구

정현,김재득 경주대학교 건설환경연구소 2000 建設環境論叢 Vol.- No.3

This study analyzed the Spatial use in the subway-station district about 10 stations in Taegu. The subway-station district were classified to three location-types ; the centers, the outskirts, and the suburbs and two radius-types ; less than 100m, above 100m. It was analyzed with the use, the scale and the density of building, the scale and shape of land, the price of land, the usage of basement space. The main findings of this research can be summarized as follows. First, in case of the center and the outskirts type, the big business and commercial facilities were not located and there was no traffic means to connect other traffic facilities opposite to the centers. Second, most land are small, irregular shape and interrupt the land usage and the landscape. Third, the usage degree of the basement space was low level, the pedestrian space was not established. Therefore, it is necessary to setup the parking lot, the plaza, the small park, etc., to extend the back road, to enlarge and standardize the land, so the development, arrangement plan has to be made to be able to raise the characteristics of the location environment because the subway-station is responsible to be the district center and traffic node.

ECAP 공정을 거친 1050 Al 합금 판재의 전기화학 특성에 관한 연구

정민경,최윤석,김정구,김영만,이재철,석현광 대한금속재료학회 2003 대한금속·재료학회지 Vol.41 No.8

The effect of equal channel angular pressing (ECAP) pass number on the electrochemical properties of AA 1050 (UNS A91050) in 0.1M Na₂SO₄ solution containing 100 ppm chloride were investigated by electrochemical techniques (potentiodynamic test, potentiostatic test, electrochemical impedance spectroscopy (EIS) and surface analyses (OM, SEM, EDS). The ECAPed specimens that have a various numbers of passes from N=l to N=5 were selected for electrochemical experiments in this study. The results of potentiodynamic test indicated that the breakdown potential increased with increasing the ECAP pass number. EIS measurements also showed that the corrosion resistance of the AA 1050 increased with increasing the ECAP pass number at the passivation and breakdown states. The results of surface analyses (SEM, EDS) showed that silicon-containing impurities were observed on the surface of the alloy. It was found that the size of these Si-containing impurities decreased with increasing the ECAP pass number. The Si-containing impurities induced the microgalvanic reaction(i) between the Al matrix and the Si-containing mixed oxide and (ii) between the Al matrix and the Si-containing impurities. Due to its ultrafine-grained microstructure, ECAPed AA 1050 had smaller Si-containing impurities, and reduced microgalvanic currents. Thus, in the case of ECAPed AA 1050, it has increasing corrosion resistance with increasing ECAP pass number because of its small cathodic impurities.