Accuracy of cardiac output measurements during off-pump coronary artery bypass grafting: according to the vessel anastomosis sites

Sung Yong Park,Dae Hee Kim,Han Bum Joe,Ji Young Yoo,Jin Soo Kim,Min Kang,Yong Woo Hong 대한마취통증의학회 2012 Korean Journal of Anesthesiology Vol.62 No.5

Background: During beating heart surgery, the accuracy of cardiac output (CO) measurement techniques may be influenced by several factors. This study was conducted to analyze the clinical agreement among stat CO mode (SCO), continuous CO mode (CCO), arterial pressure waveform-based CO estimation (APCO), and transesophageal Doppler ultrasound technique (UCCO) according to the vessel anastomosis sites. Methods: This study was prospectively performed in 25 patients who would be undergoing elective OPCAB. Hemodynamic variables were recorded at the following time points: during left anterior descending (LAD) anastomosis at 1 min and 5 min; during obtuse marginal (OM) anastomosis at 1 min and 5 min: and during right coronary artery (RCA) anastomosis at 1 min and 5 min. The variables measured including the SCO, CCO, APCO, and UCCO. Results: CO measurement techniques showed different correlations according to vessel anastomosis site. However, the percent error observed was higher than the value of 30% postulated by the criteria of Critchley and Critchley during all study periods for all CO measurement techniques. Conclusions: In the beating heart procedure, SCO, CCO and APCO showed different correlations according to the vessel anastomosis sites and did not agree with UCCO. CO values from the various measurement techniques should be interpreted with caution during OPCAB. Background: During beating heart surgery, the accuracy of cardiac output (CO) measurement techniques may be influenced by several factors. This study was conducted to analyze the clinical agreement among stat CO mode (SCO), continuous CO mode (CCO), arterial pressure waveform-based CO estimation (APCO), and transesophageal Doppler ultrasound technique (UCCO) according to the vessel anastomosis sites. Methods: This study was prospectively performed in 25 patients who would be undergoing elective OPCAB. Hemodynamic variables were recorded at the following time points: during left anterior descending (LAD) anastomosis at 1 min and 5 min; during obtuse marginal (OM) anastomosis at 1 min and 5 min: and during right coronary artery (RCA) anastomosis at 1 min and 5 min. The variables measured including the SCO, CCO, APCO, and UCCO. Results: CO measurement techniques showed different correlations according to vessel anastomosis site. However, the percent error observed was higher than the value of 30% postulated by the criteria of Critchley and Critchley during all study periods for all CO measurement techniques. Conclusions: In the beating heart procedure, SCO, CCO and APCO showed different correlations according to the vessel anastomosis sites and did not agree with UCCO. CO values from the various measurement techniques should be interpreted with caution during OPCAB.

Layer-controlled thinning of black phosphorus by an Ar ion beam

Park, Jin Woo,Jang, Sung Kyu,Kang, Dong Ho,Kim, Doo San,Jeon, Min Hwan,Lee, Won Oh,Kim, Ki Seok,Lee, Sung Joo,Park, Jin-Hong,Kim, Kyong Nam,Yeom, Geun Young Royal Society of Chemistry 2017 Journal of Materials Chemistry C Vol.5 No.41

<▼1><P>BP thinning was carried out using a monoenergetic Ar<SUP>+</SUP> ion beam and the BP could be thinned without damaging the surface.</P></▼1><▼2><P>Black phosphorus (BP) is one of the most interesting two-dimensional (2D) layered materials due to its unique properties, including a band gap energy change from 0.3 eV (bulk) to 2.0 eV (monolayer) depending on the number of BP layers, for application in nanoelectronic devices. In general, 2D layered materials including BP have limitations in terms of synthesis due to the process factors such as time, temperature, <I>etc.</I>, and thus, a thinning technique from the bulk material to a 2D material needs to be used while controlling the removed layer thickness. In this study, layer-controlled thinning of BP was performed by using a controlled Ar<SUP>+</SUP> ion beam method and the BP thinning characteristics were investigated. By using the near monoenergetic ion energy in the range of 45–48 eV, BP could be thinned with the thinning rate of ∼0.55 nm min<SUP>−1</SUP> down to bilayer BP without increasing the surface roughness and without changing the chemical binding states. The BP oxide on the pristine BP could also be successfully removed using the same Ar<SUP>+</SUP> ion beam. 2D BP field-effect transistors (FETs) fabricated with the thinned bilayer–10-layer BPs exhibited electrical characteristics similar to those of pristine BP FETs suggesting no electrical damage on the BP layers thinned by the controlled monoenergetic Ar<SUP>+</SUP> ion beam.</P></▼2>

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.

Controlled post-sulfurization process for higher efficiency nontoxic solution-deposited CuIn_0.7Ga_0.3Se₂ absorber thin films with graded bandgaps

Jang, Jin Woo,Lee, Seung Min,Choi, Ik Jin,Cho, Yong Soo ELSEVIER SCIENCE 2017 JOURNAL OF ALLOYS AND COMPOUNDS Vol.710 No.-

<P><B>Abstract</B></P> <P>A practical way of adjusting post-sulfurization process with variable durations is proposed to improve the cell-conversion efficiency of non-toxic solution driven CuIn<SUB>0.7</SUB>Ga<SUB>0.3</SUB>Se<SUB>2</SUB> absorber thin films. The degree of bandgap grading was controllable by changing the sulfurization time from 2 min to 30 min due to the dissimilar distribution of sulfur across the absorber layer. Deeper intensified distributions of Ga and S were responsible for enhancements in the open-circuit voltage and cell-conversion efficiency. A competitive efficiency of ∼8.81% for the 10 min-sulfurized CIGSSe cell was achieved with other promising parameters, i.e., short-circuit current density of 33.17 mA/cm<SUP>2</SUP>, open-circuit voltage of 0.496 V, and fill factor of 53.5%, resulting from the improved carrier collection and reduced recombination by the bandgap grading. This improved efficiency corresponds to a ∼15.6% enhancement compared to the unsulfurized sample.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Controlled post-sulfurization process enhances cell efficiency of CuIn<SUB>0.7</SUB>Ga<SUB>0.3</SUB>Se<SUB>2</SUB>. </LI> <LI> Sulfur penetrates easily toward the back contact with concentration gradient. </LI> <LI> A graded bandgap structure is responsible for the improved charge collection. </LI> <LI> The achieved cell efficiency of ∼8.81% corresponds to the ∼15.6% enhancement. </LI> <LI> Actual bandgap variations are projected on the basis of elemental distributions. </LI> </UL> </P>

Comparison of Dual Probe Bipolar Mode with Monopolar and Single Probe Bipolar Modes : Comparison of Dual Probe Bipolar Mode with Monopolar and Single Probe Bipolar Modes

Lee, Jeong Min,Han, Joon Koo,Kim,Se Hyung,Lee, Jae Young,Kim, Dae Jin,Lee, Min Woo,Cho, Gyung goo,Han, Chang Jin,Choi, Byung Ihn Korean Radiological Society 2004 Korean Journal of Radiology Vol.5 No.2

도심 수목원에서의 경관감상과 산책이 인체의 생리적 안정에 미치는 영향

박범진 ( Bum Jin Park ),가재남 ( Jae Nam Ka ),이민선 ( Min Sun Lee ),김선아 ( Seon A Kim ),박민우 ( Min Woo Park ),최윤호 ( Yoon Ho Choi ),정다워 ( Da Wou Joung ),권치원 ( Chi Weon Kwon ),염동걸 ( Dong Geol Yeom ),박순주 ( Soon Jo 한국산림과학회 2014 한국산림과학회지 Vol.103 No.4

This research was conducted to investigate the impact of viewing scenery and walking in the urban forest onphysiological relaxation of humans. The experiment was conducted in Hanbat Arboretum located in Daejeon, and thecontrol experiment was conducted in front of Daejeon City Hall. The subjects that participated in the experimentcomprised 24 Korean male university students in their 20s (average age, 21.1±2.5 years), participated in the experimentas the subject, and these subjects were classified into three groups divided into three locations such as the pine forest inArboretum, the pond in Arboretum, and the city. The subjects sat down and viewed scenery for 10 min, and they thenwalked for 15 min. Further, physiological changes were measured using indicators such as heart rate variability (HRV),blood pressure, and pulse rate. As a result, when subjects viewed scenery and walked in the urban forest, a statisticallysignificant increase in the high frequency (HF) power of HRV and decrease in systolic pressure was observed comparedwith when subjects viewed scenery and walked in the city. Through this research, it was found that activities like viewingscenery or walking in Arboretum of the city are effective in increasing the physiological relaxation of the city residents.

Flavobacterium meningosepticum에 의한 균혈증 1예

장성원,유진홍,진승원,김선우,김연식,박순민,이대훈,최민호,최주연,신완식,강문원,강지민 대한화학요법학회 1997 대한화학요법학회지 Vol.15 No.1

1996년 6월 카톨릭대학교 부천성가병원에 뇌경색으로 입원했던 61세 남자 환자의 혈액에서 Flavobacterium meningosepticum을 분리하였다. 환자는 폐렴을 동반한 패혈증의 예로 ceftriaxone과 metronidazole을 투여하였으나 입원 48시간만에 사망하였다. Flabovacterium meningosepticum is a rae cause of nosocomial infection which shows multi-drug resistance. It mainly invades patients with impaired immunity. Recently, we experienced a case of F. meningosepticum bacteremia in a patient with chronic debilitated state owing to stroke. The clinical progress was so rapid that he died within 48 hours. Blood culture revealed F. meningosepticum which showed characteristic yellow colony in blood agar plate.

유화처리 바이오디젤이 도포된 콘크리트의 침투깊이 판정

백철 ( Baek Cheol ),김태우 ( Kim Tae-woo ),이재진 ( Lee Jae-jin ),이동윤 ( Lee Dong-yun ),한민철 ( Han Min-cheol ),한천구 ( Han Cheon-goo ) 한국건축시공학회 2017 한국건축시공학회 학술발표대회 논문집 Vol.17 No.2

This study is to provide a evaluation method for the penetration depth of emulsified refined bio diesel(ERBD)applied to a surface of the concrete by using water absorption capability of the concrete. The concrete applied with ERBD was immersed at water for 1 min., 5min., and 10 min. and then was checked the brightness with elapse of time. Test results indicated that there was clear difference between ERBD part and non ERBD part in concrete specimen after measuring the brightness until 120min.

총경동맥 폐쇄시간에 따르는 국소 뇌혈류 변화 : 실험적 연구 An Experimental Cat Model

강준기,성태경,조병일,백민우,김문찬,허춘웅,하영수,송진언 대한신경외과학회 1983 Journal of Korean neurosurgical society Vol.12 No.3

The microvasculature of the brain is also quite susceptible to ischemic insult, and substantial portions of the brain are not reperfused after restoration of the blood supply following overtime of critical ischemic periods. The purpose of this series of experiments was to determine the effects of ischemia on subsequential regional cerebral blood flow measurements and cortical electric activities following reperfusion after ischemia and also to define the proper time of vascular occlusion without irreversible neural damage. Cerebral ischemia was induced in cat by bilateral common carotid occlusions for periods of 10, 30, to 60 minutes, and the blood supply was reperfused for 3 hours after clamp-off. Regional cerebral blood flow(rCBF) was measured by hydrogen clearance technique following ischemia, restoration of blood supply and electroencephalogram recovery could be predicted according to the rCBF. Forty adult cats weighing 2.7 to 4.0㎏ were used in this study. The animals were divided into 4 groups of 10 cats each : normal control, 10 min-clamped, 30 min-clamped, and 60 min-clamped groups. The results obtained were as follows : 1) The mean rCBF was 24.6±7.0㎖/100g/min in control group. 2) Bilateral carotid occlusions resulted in a reduction of the rCBF(12.4±4.1㎖/100g/min) to 50% of control flow on both hemispheres. 3) Sequential changes of the rCBF after reperfusion : (1) There was restored the rCBF(21.3±5.1㎖/100g/min) to control flow in the 10 minutes-clamped group. (2) There was a 85% recovery of control flow in the 30 minutes-clamped group. (3) There was a only 25% recovery of control flow in the 60 minutes-clamped group. 4) A close correlation was found between cortical electrical activity and rCBF suggesting a threshold relationship. (1) The changes of cortical electric activity began to notice at rCBF less than 17.4±4.7㎖/100g/min. (2) The recovery of cortical electric activity noted at rCBF more than 10.2±2.3㎖/100g/min. 5) There was no evidence of ischemic involvement at the cortex, white matter and basal ganglia in the 10 minutes clamped group, but demonstrated a dense wedge shaped infarct at the cortex and uncus herniation in the 60 minutes clamped group. The rCBF and cortical electric activity restored to normal values in reperfusion within 10 minutes after occlusion of both common carotid arteries.

산업현장 추락에 대한 기계학습 알고리즘 기반의 다집단 분류

구범모(Bum Mo Koo),김종만(Jong Man Kim),남예진(Ye Jin Nam),성동진(Dong Jin Sung),심재우(Jae Woo Shim),양수민(Su Min Yang),김영호(Young Ho Kim) 대한기계학회 2022 大韓機械學會論文集A Vol.46 No.3

본 연구에서는 웨어러블 관성센서를 사용하여 산업현장 추락에 대한 기계학습 기반의 다집단 분류를 시도하였다. 20명의 건강한 성인 남성을 모집하였으며, 15가지 non-FFH 동작과 5가지 low-hazard-FFH 동작 그리고 한 가지 high-hazard-FFH 동작을 3회씩 반복 측정하였다. 5개의 기계학습 기법(SVM, k-NN, LDA, QDA, MLP)에 대하여 two-class 분류성능과 three-class 분류성능을 비교하였다. 분석 결과 SVM이 two-class 분류와 three-class 분류에서 각각 99.5%와 98.2%의 가장 높은 정확도를 보였다. 또한, 세 가지 전처리 기법들(SMOTE, min-max 정규화, univariant feature selection) 역시 알고리즘 성능 향상에 기여함을 볼 수 있었다. In this study, a multi-class classification of industrial fall from height (FFH) based on machine learning was tried using a wearable inertial sensor. Twenty healthy adult males were recruited for the experiment. The experiment protocol consisted of 15 non-FFH, five low-hazard-FFH, and one high-hazard-FFH. Each motion was conducted three times repeatedly. Two-class classification performance and three-class classification performance were compared for five different machine learning techniques (SVM, k-NN, LDA, QDA, and MLP). As a result, SVM showed the highest accuracy of 99.52% and 98.25% in two-class classification and three-class classification, respectively. In addition, the three preprocessing techniques (SMOTE, min-max regularization, and univariant feature selection) contributed to the improvement of algorithm performance.