아세틸 콜린 유발 검사시 허혈성 심전도 변화와 흉통의 발생이 내피세포 기능장애에 미치는 영향

최철웅(Cheol Ung Choi),나승운(Seung-Woon Rha),김선원(Sun Won Kim),나진오(Jin Oh Na),임홍의(Hong Euy Lim),김진원(Jin Won Kim),김응주(Eung Ju Kim),한성우(Seong Woo Han),박창규(Chang Gyu Park),서홍석(Hong Seog Seo),오동주(Dong Joo Oh) 대한임상노인의학회 2010 대한임상노인의학회지 Vol.11 No.4

연구배경: 아세틸 콜린 유발 검사시 발생하는 흉통과 허혈성 심전도 변화가 아세틸 콜린에 의해 발생하는 관상동맥의 내피세포 기능에 어떤 영향을 주는지 알아보고자 했다. 방법: 흉통으로 내원하여 관상동맥 조영술과 아세틸 콜린 유발검사를 시행받은 1,085명의 환자를 대상으로 하였다. 아세틸 콜린 유발 검사를 하는 동안 허혈성 심전도 변화 및 흉통의 발생 유무에 따른 관상동맥 내피세포 기능의 특징을 비교하였다. 결과: 539명의 환자에서 아세틸 콜린 검사시 내피세포 기능 장애가 발생 하였다. 허혈성 심전도 변화가 있었던 그룹이 심전도 변화가 없었던 그룹보다 흉통이 더 많았고(78.1% vs. 60.8%, P=0.007), 관상동맥 조영술상 다발성 관상동맥 경련이 빈번하였고(59.4% vs. 40.6%, P=0.004), 관상동맥의 경련 정도도 더 심하였다(64.1% vs. 46.5%, P=0.006). 흉통이 있었던 그룹이 흉통이 없었던 그룹보다 허혈성 심전도 변화의 빈도가 더 높았다(14.7% vs. 7.5%, P=0.007). 또한 흉통이 있었던 그룹이 관상동맥 경련이 다발성으로 발생하는 경우가 많았고 (50.7% vs. 29.5%, P<0.001), 미만성으로 발생하는 경우가 많았고(87.1% vs. 75%, P<0.001), 관상동맥의 경련의 정도도 더 심하였다(51.6% vs. 43.5%, P=0.041). 결론: 아세틸 콜린 유발검사시 발생하는 허혈성 심전도 변화와 흉통은 관상동맥 경련의 정도와 경련이 발생하는 관상동맥 개수와 연관이 있다. Background: ECG changes and chest pain during acetylcholine (Ach) provocation tests may constitute important clinical parameters for Ach-induced endothelial dysfunction. We investigated the association between ischemic ECG changes and chest pain during the Ach-provocation test and angiographic characteristics of Ach-induced endothelial dysfunction. Methods: A total of 1,085 patients with anginal symptoms underwent diagnostic coronary angiography (CAG) and Ach-provocation tests. We compared angiographic characteristics of Ach-induced endothelial dysfunction according to the presence of ECG change and chest pain. Results: A total of 539 patients experienced Ach-induced endothelial dysfunction. Patients who experienced ECG change group suffered more frequent chest pain (78.1% vs. 60.8%, P=0.007), angiographically more frequent multiple coronary artery spasm (59.4% vs. 40.6%, P=0.004), and more severe coronary artery spasm (64.1% vs. 46.5%, P=0.006) than patients without ECG change. However, there was no difference in the length of endothelial dysfunction between the groups. The incidence of ischemic ECG changes in patients with chest pain was higher than in patients without chest pain (14.7% vs. 7.5%, P=0.007). Patients who experienced chest pain more often experienced multiple (50.7% vs. 29.5%, P<0.001), diffuse (87.1% vs. 75%, P<0.001), and severe coronary artery spasm (51.6% vs. 43.5%, P=0.041) than patients without chest pain. Conclusion: Ischemic ECG changes and chest pain during the Ach-provocation test are associated with multi-vessel involvement and severe coronary artery spasm. Chest pain is associated with the length of endothelial dysfunction, but ischemic ECG change is not.

서울의 Penicillinase Producing Neisseria Gonorrhoeae 발생빈도(1996)

김재홍,황동규,전재홍,김윤석,김중환,김용준,이창균,임동진,김현수,조창근,김경문,박상훈,전우형,김희성,이호정,차명수,김갑형,김형석,김석우,황지환,박병순,권오상,이민수,송기훈,성소영,이인섭,부태성 대한화학요법학회 1999 대한화학요법학회지 Vol.17 No.2

Background : In recent years, gonorrhea has been panedemic and remains one of the most commom STDs in the world, especially in developing countries. Objective & Methods: For the detection of a more effective therapeutic regimen and assessing the prevalence of PPNG, we have been trying to study the patients who have visited the VD Clinic of Choong-Ku Public Health Center in Seoul since 1980 by means of the chromogenic cephalosporin method. Results: In 1996, 139 strains of N. gonorrhoeae were isolated, among which 53(39.0%) were PPNG. Conclusion: Our results suggests that after a peak of 74.3% in 1993, the prevalence of PPNG in Seoul is gradually declining.

Rat의 복강내에 투여한 5-fluorouracil-polyglycolic acid 제형이 장기에 미치는 영향에 관한 연구

강대영,송규상,최정목,노승무,정경수,오정연,김진향,양준묵,최선웅,이진호,조준식,민병무,김용백,김창식,박근성,김승영,김학용,인현빈 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.1

For more effective intraperitoneal chemotherapy, the authers made 5-fluorouracil-polyglycolic acid composite disks(FU-PGA disks) with 5-fluorouracil and polyglycolic acid, a biodegradable polymer. We inserted the FU-PGA disk into the peritoneal cavites of Sprague-Dawley male rats, the control and three experimental groups; one FU-PGA disk insert group(300mg/kg), two FU-PGA disk insert group(600mg/kg), and three FU-PGA disk insert group(900mg/kg). The control group received a similar number of PGA disk inserts. A pharmacokinetic study was performed to measure the 5-fluorouracil concentration in the peritoneal fluid, blood, and tissues(liver, kidney and heart) at 24 hours, 72hours and 168 hours after insertion of the FU-PGA disk. Light and electron microscopic studies were done. The results were as follows: 1) The number of white blood cells and platelets decreased after FU-PGA insertion. The degree was proportional to the duration and amounts inserted. The change in the number of red blood cells varied slightly. 2) Light microscopically, slight changes were noted at 168 hours in the 3 disk insert group (900mg/kg). Mild fatty change and hepatocyte degeneration around the central veins of the liver were noted, with vacuolar degeneration in the proximal convoluted tubules of the kidney. 3) Electron microscopically,the liver showed focal increases of lipid droplets in the hepatocytes, and irregular nuclear membrane with focal nucleolar segregation of the fibrillar and granular elements. Also the double membranous structure of the hepatocytes and Kupffer cells was widened with bleb formation. The kidney showed wide separation of the nuclear double membrane in the proximal convoluted tubular cells and mesangial cells, with vacuolation and myelin figure formation in the mitochondria of the proximal convoluted tubular cells, at 72 hours and 168 hours in the 2 to 3 FU-PGA insert groups. The heart showed focal loss of cristae,vacuolation and myelin figure formation in the mitochondria of the 2 to 3 FU-PGA insert groups. In conclusion, despite the large amont of FU-PGA inserted, the histopathological changes in the liver, kidney and heart were slight, and consonant with the very low amount of 5-fluorouracil concentrations detected in the liver, kidney and heart. The above results suggest that the FU-PGA composite can serve as a new device for releasing drugs in a controlled manner and easily targeted to intraperitoneal organs. This device can improve the efficacy of intraperitoneal chemotherapy for gastric cancer.

정신분열병에 대한 리스페리돈의 효과 및 안정성

이민수,김용구,김영훈,연병길,오병훈,윤도준,윤진상,이철,정희연,강병조,김광수,김동언,김명정,김상훈,김희철,나철,노승호,민경준,박기창,박두병,백기청,백인호,손봉기,손진욱,양병환,양창국,우행원,이정호,이종범,이홍식,임기영,전태연,정영조,정영철,정인과,정인원,지익성,채정호,한상익,한선호,한진희,서광윤 大韓神經精神醫學會 1998 신경정신의학 Vol.37 No.1

연구목적 : 본 시험의 목적은 임상시험 시작전에 연구자들을 대상으로 PANSS Workshop을 통하여 PANSS, ESRS에 대한 국내에서의 표준화 작업을 구축하고 새로운 정신병 치료제인 리스페리돈의 효과와 안정성을 재확인하여 리스페리돈 사용에 대한 적정화를 이루는데 있다. 연구방법 : 1996년 4월부터 1996년 9월까지 국내 39개 대학병원 정신과에 입원중인 혹은 증상이 악화되어 입원하는 정신분열병 환자 377명을 대상으로 다시설 개방 연구를 시행하였다. 1주일간의 약물 배설기간을 가진후, 리스페리돈을 8주간 투여하였고, 기준점, 1주, 2주, 4주, 그리고 8주후에 평가되었다. 용량은 제1일에는 리스페리돈 1mg씩 1일 2회, 제2일에는 2mg씩 1일 2회, 제3∼7일에는 3mg씩 1일 2회 투여하였다. 이후 환자의 임상상태에 따라 임의로 증량할 수 있으며, 최대 일일 16mg을 초과하지 않도록 하였다. 추체외로 증상을 조절하기 위한 투약을 허용하였다. 임상증상 및 부작용의 평가는 PANSS(Positive and Negative Syndrome Scale), CGI(Clinical Global Impression) 그리고 ESRS(Extrapyramidal Symptom Rating Scale)을 사용하였다. 연구결과 : 377명중 343명(91%)이 8주간의 연구를 완결하였다. 치료 종결시점인 8주후 PANSS 총점수가 20% 이상 호전된 경우를 약물 반응군으로 정의할때, 약물반응군은 81.3%였다. 리스페리돈에 반응하는 예측인자로는 발병연령, 이전의 입원 횟수, 유병기간이 관련 있었다. 리스페리돈은 1주후부터 PANSS양성, 음성, 및 일반정신병리 점수상에 유의한 호전을 보여 효과가 빨랐다. CGI의 경우도 기준점에 비해 1주후부터 유의한 감소를 나타내었다. ESRS의 경우, 파킨슨 평가점수는 기준점과 비교해 투여 1주, 2주, 4주후 유의하게 증가되었다가 8주후 기준점과 차이가 없었다. Dystonia 평가점수는 1주후만 유의한 증가를 보였으며, dyskinesia 평가점수는 유의한 차이가 없었다. 혈압, 맥박수의 생명징후 및 일반 혈액학 검사, 생화학적 검사, 심전도 검사에서 유의한 변화는 없었다. 결 론 : 이상의 다시설 개방 임상 연구를 통해 리스페리돈은 정신분열병 환자에서 양성증상뿐만 아니라 음성증상 및 전반적인 증상에도 효과적인 것으로 사료된다. 보다 명확한 평가를 위해서는 다른 항정신병약물과의 이중맹검 연구가 필요할 것으로 생각되며, 또한 장기적 치료에 대한 평가도 함께 이루어져야 하겠다. Objective : The purpose of this study was to investigate the efficacy and safety of risperidone in the treatment of Korean schizophrenic patients. Method : This multicenter open study included 377 schizophrenic patients drawn from 39 university hospitals. After a wash-out period of 1 week, the schizophrenic patients were treated with risperidone for 8 weeks and evaluated at 5 points ; at baseline, and 1, 2, 4 and 8 weeks of treatment. The dose was increased from 2mg/day(1mg twice daily) to 6mg/day(3mg twice daily) during the first week and adjusted to a maximum of 16mg/day over the next 7 weeks according to the patient's clinical response. Medication to control extrapyramidal symptoms was permitted. The psychiatric and neurological status of the patients was assessed by PANSS, CGI, and ESRS scales. Results : 343(91%) of 377 patients completed the 8-week trial period. Clinical improvement, as defined by a 20% or more reduction in total PANSS score at end point, was shown by 81.3% of patients. The predictors of response to risperidone were associated older age, shorter duration of illness, fewer previous hospitalization. Risperidone had rapid onset of action ; a significant decrease of the total PANSS and three PANSS factor(positive, negative, general), and CGI was already noticed at the end of first week. For the ESRS, parkinsonism rating scores were significantly increased until week 4 comparing with baseline. Dystonia rating scores were significantly increased until week 1, and dyskinesia rating scores were not significantly changed during the study. Laboratory parameters including vital sign, EKG, hematological, and biochemical values showed no significant changes during the trial. Conclusions : This study suggests that risperidone is generally safe and effective against both the positive and negative symptoms in our group of patients.

在日韓國人의 生活文化의 異質化와 適應過程에 關한 保健學的 硏究

金正根(Jong-Kun Kim),張昌谷(Chang-Gok Chang),林達旿(Dar-Oh Lim),金武采(Mu-Chae Kim),李州烈(Ju-Yul Lee) 한국인구학회 1992 한국인구학 Vol.15 No.2

After world war Ⅱ Japanese life expectancy has been improved remarkably, and reached the highest level in the world around late 1970's. The life expectancy of Korean has also shown tremendous improvement in recent years with about 20 year's gap from the Japanese. The reason of rapid improvement of life expectancy can be explained by changes in the structure of cause of death due to health system, living standard, social welfare, health behavior of individuals and so on. Korean in Japan is placed under different situations from both Korean in Korea and Japanese in these regards, and expected to show different picture of cause of death pattern. The objective of this study is the comparision of changing patterns of cause of death of three population groups, Korean in Japan, Korean in Korea and Japanese, and to investigate the reasons which effect to the structural difference of mortality cause with special emphasis on health ecological aspects. One of the major limitations of the Korean causes of death statistics is the under-registration which ranges about 10% of the total events, and inaccuracy of the exact cause of death. Some 20% of registered deaths were unable to classify by ICD. However, it is concluded that the Korean data are evaluated as sufficient to stand for over-viewing of trends of cause of death pattern. The evaluation is done by comparing data from registration and field survey over the same population sample. Population data of Korean in Japan differ between two sources of data; census and foreigner's registration. Correction is done by life table method under the assumption that age-specific mortality pattern would accord with that of the Japanese. The crude death rate was lowest among Korean in Japan, 5.7 deaths per 1,000 population in 1965. The crude death rates of Korean in Japan and Japanese are increasing recently influenced by age structure while Korean in Korea still shows decreasing tendency. The adjusted death rate is lowest among Japnaese, followed by Korean in Japan, and Korean in Korea. The leading causes of death of Korean in Korea until 1960's was infectious diseases including pneumonia and tuberculosis. The causes of death structure changed gradually to accidents, neoplasm, hypertensive disease, cerebro-vascular disease in order. The main difference in cause of death between Korean and Japanese is high rate of liver diseases and diabetes for both Korean in Japan and Korea. A special feature of cause of death among Korean in Korea is remakably high rate of hypertensive disease, which is assumed to be caused by physicians tendency in choosing diagnostic categories. The low ischemic heart disease and high vasculo-cerebral disease are the distinctive characteristic of the three population groups compared to western countries. Specific causes of death were selected for detailed sex, age and ethnic group comparisons based on their high death rates. Cancer is the cause of death which showed most drama tical increase in all three population groups. In Korea 20.1% of all death were caused by cancer in 1990 compared with 10.5% in 1981. Cancer of the liver is the leading cause of cancer death among Korean in Japan for both sexes, followed by cancer of the lung and cancer of the stomach, while that of Korean in Korea is cancer of the stomach, followed by cancer of the liver and cancer of the lung for male. Causes of infant mortality were examined among the three population groups since 1980 on yearly bases. For both Japanese and Korean in Japan, leading cause of death ranks as conditions originating in the perinatal period, congenital anomalies, accidents and other violent causes. Trends since 1980 for these two population groups in the leading cause of infant mortality showed no changes. On the contrary, significant changes in leading cause of death structure in Korea were observed : The ranking of leading cause of death in 1981 were congenital asnomali

Causes and Predictive Factors Associated with "Diagnosis Changed" Outcomes in Patients Notified as Tuberculosis Cases in a Private Tertiary Hospital

Kang, Byung Ju,Jo, Kyung-Wook,Park, Tai Sun,Yoo, Jung-Wan,Lee, Sei Won,Choi, Chang-Min,Oh, Yeon-Mok,Lee, Sang-Do,Kim, Woo Sung,Kim, Dong Soon,Shim, Tae Sun The Korean Academy of Tuberculosis and Respiratory 2013 Tuberculosis and Respiratory Diseases Vol.75 No.6

Background: The aim of our study was to evaluate the "diagnosis changed" rate in patients notified as tuberculosis (TB) on the Korean TB surveillance system (KTBS). Methods: A total of 1,273 patients notified as TB cases on the KTBS in one private tertiary hospital in 2011 were enrolled in the present study. Patients were classified into three groups: "diagnosis maintained", "diagnosis changed" (initially notified as TB, but ultimately diagnosed as non-TB), and "administrative error" (notified as TB due to administrative errors). Results: Excluding 17 patients in the "administrative error" group, the "diagnosis maintained" and "diagnosis changed" groups included 1,097 (87.3%) and 159 patients (12.7%), respectively. Common causes of "diagnosis changed" were nontuberculous mycobacterial (NTM) disease (51.7%, 61/118), and pneumonia (17.8%) in cases notified as pulmonary TB, and meningitis (19.5%, 8/41) and Crohn's disease (12.2%) in cases notified as extrapulmonary TB. Being older than 35 years of age (odds ratio [OR], 2.18) and a positive acid-fast bacilli stain (OR, 1.58) were positive predictors and a TB-related radiological finding (OR, 0.42) was a negative predictor for a "diagnosis changed" result via multivariate logistic regression analysis in pulmonary TB cases. Conclusion: Because of a high "diagnosis changed" rate in TB notifications to the KTBS, the TB incidence rate measured by the KTBS may be overestimated. Considering the worldwide trend toward increased NTM disease, the "diagnosis changed" rate may increase over time. Thus, when reporting the annual TB notification rate in Korea, the exclusion of "diagnosis changed" cases is desirable.

Causes and Predictive Factors Associated with “Diagnosis Changed” Outcomes in Patients Notified as Tuberculosis Cases in a Private Tertiary Hospital

( Byung Ju Kang ),( Kyung Wook Jo ),( Tai Sun Park ),( Jung Wan Yoo ),( Sei Won Lee ),( Chang Min Choi ),( Yeon Mok Oh ),( Sang Do Lee ),( Woo Sung Kim ),( Dong Soon Kim ),( Tae Sun Shim ) 대한결핵 및 호흡기학회 2013 Tuberculosis and Respiratory Diseases Vol.75 No.6

Background: The aim of our study was to evaluate the “diagnosis changed” rate in patients notified as tuberculosis (TB) on the Korean TB surveillance system (KTBS). Methods: A total of 1,273 patients notified as TB cases on the KTBS in one private tertiary hospital in 2011 were enrolled in the present study. Patients were classified into three groups: “diagnosis maintained”, “diagnosis changed” (initially notified as TB, but ultimately diagnosed as non-TB), and “administrative error” (notified as TB due to administrative errors). Results: Excluding 17 patients in the “administrative error” group, the “diagnosis maintained” and “diagnosis changed” groups included 1,097 (87.3%) and 159 patients (12.7%), respectively. Common causes of “diagnosis changed” were nontuberculous mycobacterial (NTM) disease (51.7%, 61/118), and pneumonia (17.8%) in cases notified as pulmonary TB, and meningitis (19.5%, 8/41) and Crohn`s disease (12.2%) in cases notified as extrapulmonary TB. Being older than 35 years of age (odds ratio [OR], 2.18) and a positive acid-fast bacilli stain (OR, 1.58) were positive predictors and a TB-related radiological finding (OR, 0.42) was a negative predictor for a “diagnosis changed” result via multivariate logistic regression analysis in pulmonary TB cases. Conclusion: Because of a high “diagnosis changed” rate in TB notifications to the KTBS, the TB incidence rate measured by the KTBS may be overestimated. Considering the worldwide trend toward increased NTM disease, the “diagnosis changed” rate may increase over time. Thus, when reporting the annual TB notification rate in Korea, the exclusion of “diagnosis changed” cases is desirable.

계면활성제를 첨가한 TMA-포접화합물의 상변화에 관한 실험적 연구

김창오,정낙규,김진흥,오율권 朝鮮大學校 機械技術硏究所 2001 機械技術硏究 Vol.4 No.1

The purpose of this study is to investigate the propriety of TMA clathrate as a cold storage medium. Particularly, this is to examine the extent of subcooling improvement when the surfactants are added to the TMA clathrate, because water used cold storage material has low phase change temperature and subcooling. This study has been analyzed and compared with TMA 30wt% clathrate how phase change temperature, subcooling and specific heat in the various concentrations are changed. This results view to be improved phase change temperature and subcooling of TMA30wt% as a cold storage medium, when it had some surfactant. Additionally, it is that surfactant must be controlled under available solution limit and study for new additive must be lasted to know its effect.

고등어 염장중 N-Nitrosodimethylamine 생성 및 그 전구물질들의 변화

金洙賢,吳昌璟 제주대학교 1993 논문집 Vol.36 No.-

여러 식품에서 아질산염과 제2급 및 제3급 아민 또는 제4급 암모니윰 화합물과의 상호작용에 의해 형성 되어지는 N-nitrosamine은 상당한 관심의 대상이 되고 있다. 본 연구는 5℃에 저장된 염장고등어에서 발암성 N-nitrosamine의 생성과 이의 전구물질인 DMA-N, TMA-N, betaine-N choline-N 및 총 creatinine의 변화를 10일 주기로 조사하였다. 또한, Ames의 표준평판 혼성시험법의 변법인 예비배양법을 이용하여 NDMA의 돌연변이유발 활성을 검정하였다. 본 연구에서 얻은 결과를 요약하면 다음과 같다. 1) pH는 10% 및 20% 염장품이 각각 5.62-5.73과 5.68-5.93으로 N-nitrosamine 생성 최적 pH보다 높은 범위에서 변화하였다. 수분은 생시료에 비해 훨씬 낮은 양으로 변화하였다. 수분은 생시료에 비해 훨씬 낮은 양으로 변화하였다. 염도는 각각 저장 20일 경과후에 5.7 및 11.4%이었고, 이 후 서서히 증가하여 저장 말기에는 각각 7% 및 13%의 염분침투가 이루어 졌다. V.B.N.은 저장초기에 급격히 증가하였으며 전반적으로 V.B.N.은 10%가 20% 염장품보다 약간 높은 함량 변화를 보였으나, 어류의 초기 부패치인 30mg/100g을 초과하지 않은 것으로 보아 저장기간 전반에 걸쳐 부패가 진행되지 않았음을 알 수 있었다. 2) 총 creatinine-N과 betaine-N 등의 제4급 암모니윰 화합물은 저장 중기에 상당히 증가하였으나, 저장 중기 이후에는 감소한 반면, cholone-N는 저장중에 조금씩 계속 증가하였다. 3) TMAO-N와 TMA-N 함량은 저장 초기에 변화가 심하였으나, 대체적으로 TMAO-N는 증가하고 TMA-N는 감소하는 역상관관계를 보였다. 4) DMA-N 함량은 저장중에 계속 증가하였으며, 10%과 20% 염장품간의 차이는 거의 없었다. 5) NDMA는 10% 및 20% 염장품이 각각 저장 20일 및 30일 경과시부터 검출되었으며 그 함량은 극히 낮았다. 반면, 아질산염 첨가구의 경우, 비첨가구 보다 약 500배 낮은 함량 변화를 보였으며, 대체적으로 저장기간중에 조금씩 증가하였다. 6) 돌연변이유발 활성은 plate당 1㎍(10ppm)의 NDMA를 첨가한 TA100 균주에서 가장 높게 나타났다. 결론적으로, 고등어 염장중 NDMA 생성 가능성은 아질산염과 DMA간의 상호작용에 의해서는 물론, 아질산염과 제3급 amine 및 제4급 ammonium염과의 상호작용에 의해 영향을 받으며, 저염 및 고염 염장품의 차이는 거의 없는 것으로 나타나기 때문에 저염고등어 제법을 개발하였을 때 NDMA 생성과는 무관하다고 판단되었다. NDMA의 돌연변이유발 활성은 10-100ppm의 농도에서 나타났다. The possibility of formation of carcinogenic N-nitrosodimethylamine and changes of their precursors in salted mackerel, Scomber japonicus, stored at 5℃ were periodically investigated, and changes of precursors between low (10%) and high (20%) salted mackerel was compared. The results were as follow; 1) Changes of pH were in the ranges of 5.62-5.73 and 5.68-5.93 in 10% and 20% salted mackerel during their storage, respectively. 2) Moisture changes in very low contents in compared with fresh sample. 3) Salinity gradually increased in low and high salted mackerel and salt permiation of 7 percent and 13 percent was accomplished during storage of both groups, respectively. 4) The contents of total creatinine and betaine remarckably increased at the middle of storage, while choline contents was scarcely changed. 5) The contents of trimethylamine oxide and trimethylamine severely varied at the beginning of storage. Changes of contents between TMAO and TMA showed, apparently, reverse relationship. 6) The contents of dimethylamine showed nearly same increasing pattern and continuously increased during storage in both groups. 7) In the low salted mackerel, N-nitrosodimethylamine was detected from 20 days of storage, while in the high salted mackerel, it was detected from 30 day of storage. In both salted mackerel added sodium nitrite, the contents of NDMA were more 500 times than those in both salted mackerel without sodium nitrite. In conclusion, it was found by this study that the possibility of formation of NDMA might be affected not only by the interaction between nitrite and DMA but also by the interaction between nitrite and TMA, TMAO, choline, betaine, and creatinine in salted mackerel during storage. No difference of the contents of precursors and NDMA between both Samples(10% & 20% NaCl) was nearly.

Control of Reversible Self-Bending Behavior in Responsive Janus Microstrips

Oh, Myung Seok,Song, Young Shin,Kim, Cheolgyu,Kim, Jongmin,You, Jae Bem,Kim, Taek-Soo,Lee, Chang-Soo,Im, Sung Gap American Chemical Society 2016 ACS APPLIED MATERIALS & INTERFACES Vol.8 No.13

<P>Here, we demonstrate a simple method to systematically control the responsive self-bending behavior of Janus hydrogel microstrips consisting of a polymeric bilayer with a high modulus contrast. The Janus hydrogel microstrips could be easily fabricated by a simple micromolding technique combined with an initiated chemical vapor deposition (iCVD) coating, providing high flexibility in controlling the physical and chemical properties of the microstrips. The fabricated Janus hydrogel microstrip is composed of a soft, pH-responsive polymer hydrogel layer laminated with a highly cross-linked, rigid thin film, generating a geometric anisotropy at a micron scale. The large difference in the elastic moduli between the two layers of the Janus microstrips leads to a self-bending behavior in response to the pH change. More specifically, the impact of the physical and chemical properties of the microstrip on the self-bending phenomena was systematically investigated by changing the thickness and composition of two layers of the microstrip, which renders high controllability in bending of the microstrips. The curvature of the Janus microstrips, formed by self-bending, highly depends on the applied acidity. A reversible, responsive self-bending/ unbending exhibits a perfect resilience pattern with repeated changes in pH for 5 cycles. We envision that the Janus microstrips can be engineered to form complex 3D microstructures applicable to various fields such as soft robotics, scaffolds, and drug delivery. The reliable responsive behaviors obtained from the systematic investigation will provide critical information in bridging the gap between the theoretical mechanical analysis and the chemical properties to achieve micron-scale soft robotics.</P>