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>

Aerobic exercise training enhances cell proliferation and reduces IL-2 and IL-6 cytokine production in spleen of high fat diet-induced obese mice

( Hee Geun Park ),( Deog Jo Jung ),( Jun Hyun Jeong ),( Jong Kui Jun ),( A Ram Yoon ),( Young Ran Lee ),( Kyung Eun Min ),( Myung Hwa Kim ),( Kwang Moo Lee ),( Wang Lok Lee ) 한국운동영양학회 2013 Physical Activity and Nutrition (Phys Act Nutr) Vol.17 No.1

This study investigated the effect of aerobic exercise training on immune cell proliferation and inflammatory cytokine production in the spleen of high fat diet-induced obese mice. C57B1J6 male mice (4 weeks aged. n20) were fed a high fat diet (45% fat) for 5 weeks so that obesity was led intentionally. Then, these obese mice were divided into 2 groups: control group (CON. n10) or exercise group (EXE, n=l0). EXE performed treadmill running for 30-60 min/day at 10-22 m/min, 0% grade, five times per week for 8 weeks. After 13 weeks, all the splenocyte was collected and Con A (Concanvalin A 10 ㎍/ml) was used to stimulate the cell proliferation. MTS and BIOPLEX assay were used for cell proliferation and cytokine production. Independent t-test was used and a p-value under 0.05 was considered as statistically significant. In the results, body weight, IL-2 and IL-6 production were significantly reduced and Splenocyte proliferation was significantly increased after 8 weeks of exercise training. These findings suggest that aerobic exercise training has a positive effect for improving the obese-induced immune dysfunction.

The Effect of Aerobic Exercise Training Versus Resveratrol Supplementation on Mitochondrial Biogenesis in Skeletal Muscle of High-fat Diet-induced Obese Mice

Kyung-Il Kim(김경일),Sang-Min An(안상민),Hee-Geun Park(박희근),Wang-Lok Lee(이왕록) 한국생명과학회 2019 생명과학회지 Vol.29 No.8

본 연구에서는 고지방식이로 유발된 비만 쥐의 골격근에서 유산소 운동과 레스베라트롤 투여가 미토콘드리아 생합성에 미치는 영향을 조사하였다. 4주령 C57BL/6의 수컷 쥐를 이용하여, 일반 식이 그룹(NC, n=10), 고지방식이 그룹(HR, n=10), 레스베라트롤 투여와 고지방식이 그룹(HRe, n=10), 유산소 운동 그룹(HE, n=10)으로 분류하였다. 유산소 운동은 16주 동안 40~60 min/day 동안 10-14m/min, 0% grade의 강도로 주당 4회 트레드밀 운동을 실시하였고, 레스베라트롤은 16주 동안 1일 1회, 주당 4회 체중 당 25 mg/kg을 투여하였다. COX-IV mRNA 발현은 NC와 HC 그룹 간에 유의한 차이가 있었으며(p<0.05), HE 그룹의 SIRT-3, PGC-1α 및 COX-IV mRNA 발현은 HC 및 HRe 그룹에 비해 유의하게 증가하였다(p<0.05). 또한, 오직 HE 그룹의 PGC-1α 및 COX-IV mRNA의 발현만이 HC 그룹에 비해 유의하게 증가하였다(p<0.05). 이상의 결과를 종합해보면, 고지방식이로 유발된 비만 쥐는 골격근에서 미토콘드리아 생합성 유전자 발현에 영향을 나타내지 않는 것으로 보인다. 하지만, 유산소 운동 훈련은 고지방식이로 유발된 비만 쥐의 골격근에서 미토콘드리아 생합성 유전자 발현을 증가시키는 것으로 나타났다. 이러한 연구 결과는 레스베라트롤 투여가 아닌 유산소 운동이 고지방식이로 유도된 쥐의 골격근에서 미토콘드리아 생합성에 긍정적인 영향을 미친다는 것을 시사한다. The purpose of this study was to analyze the effects of aerobic exercise and resveratrol supplementation on mitochondrial biogenesis in skeletal muscle of high-fat diet-induced obese mice. In this study, 4-wk-old C57BL/6 male mice were divided into four groups, with 10 animals in each group: a normal diet group (NC), high-fat diet group (HC), high-fat diet group with resveratrol supplementation (HRe), and high-fat diet GROUP with exercise (HE). Aerobic exercise was performed on a treadmill for 40~60 min/d at 10~14 m/min, 0% grade, 4 d/wk for 16 wk. Resveratrol (25 mg/kg bodyweight) was administrated once a day, 4 d/wk for 16 wk. There was a significance difference in COX-IV mRNA expression in the NC group versus that in the HC group (p<0.05). The expression of the SIRT-3, PGC-1a, and COX-IV mRNA genes in the HE group increased significantly as compared with the expression of these genes in the HC and HRe groups (p<0.05). These results indicated that high- fat diet- induced obesity did not affect mitochondria biogenesis gene expression in skeletal muscle. In contrast, aerobic exercise training increased the expression of mitochondria biogenesis gene expression in skeletal muscle in high-fat diet-induced obese mice. These findings suggested that aerobic exercise but not resveratrol supplementation had a positive effect on mitochondrial biogenesis in skeletal muscle in high-fat diet-induced obese mice.

조증환자의 약물 순응도에 영향을 미치는 요인

박성근,이민수,곽동일,정인과 大韓神經精神醫學會 1999 신경정신의학 Vol.38 No.4

연구목적 : 약물의 순응도는 조증환자의 장기적인 치료 결과 및 예후에 있어서 가장 중요한 사항중 하나이다. 그동안 조증환자의 약물 순응도에 관한 연구들은 많이 있어왔으나 대부분 단면적인 연구이며, 또한 첫 번째 삽화를 기준으로 조사된 연구는 없었다. 양극성 장애와 분열정동장애에서의 약물 순응도에 대한 국내 연구는 드물다. 따라서 저자들은 조증 환자에서의 약물 순응 정도를 조사하고, 약물 비순응과 연관된 여러 요인들에 대해 알아보고자 하였다. 방 법 : 환자의 순응도는 환자의 자가보고, 보호자의 보고, 치료자의 추정, 조사자와의 면담, 진료 약속의 이행, 그리고 약물의 혈중 농도등을 통하여 평가하였다. 순응도와 연관된 요인에 대한 자료들은 환자-관련 요인, 질병-관련 요인, 치료-관련 요인으로 나누어 의무기록의 검토와 환자와의 직접적인 면담을 통해 수집하였다. 결 과 : 전체 71명의 환자중 40명(56.3%)이 첫 치료기간 도중 약물치료에 비순응한 것으로 나타났다. 비순응은 아동기 외상적 사건의 경험(p=.035), 정신병적 증상의 존재(p=.020), 그리고 기분 안정제의 병합사용(p=.002) 등의 요인들과 유의한 상관관계가 있었다. 결 론 : 아동기에 심각한 스트레스성 사건을 경험한 환자, 조증삽화동안 망상이나 환각등의 증상을 보였던 환자, 그리고 두가지 이상의 기분 안정제를 병합 투여받은 환자들이 약물 치료에 순응하지 못하는 것으로 나타났다. Objectives : Drug compliance is the most important issue in long-term treatment outcome and prognosis of manic patients. Up to date, there has been no study about drug compliance at the point of the first manic episode and subsequent maintenance period. And also there are limited data regarding the rates of noncompliance in patients with biopolar disorder and schizoaffective disorder in Korea. So the author studied about the rate of noncompliance in manic patients and about the clinical predicting factors associated with their drug compliance. Methods : Compliance of a patient was assessed by patient's report, family member's report, treater's estimation, investigator-administered questionnaire, record of unkept appointment and plasma concentration of mood-stabilizer. Data about patient-related, illness-related and interview with the patient. Results : Forty patients(56.3%) were noncompliant with their pharmacologic regimen at the point of the first treatment period. Noncompliance was significantly associated with experience of childhood stressful life events(p=.035), presence of psychotic symptoms(p=.020) and treatment with combination of mood-stabilizers(p=.002). Conclusion : Patients who experienced serious life event in their childhood, had delusion or hallucination during the manic episode, or received the combination therapy of mood-stabilizer are prone to fail in treatment adherence.

공정단위장치로부터의 휘발성유기화합물질의 비산 배출량 산정

박영근,문정우,고민수,박현수,차순우,이선우,홍승철,김화용,이종협 한국화학공학회 2003 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.41 No.3

공장내 설치되어 있는 수천개의 비산배출원으로부터 배출되는 VOCs의 양을 산정하기 위해서는 많은 비용과시간이 소요된다. 이러한 노력을 줄이기 위하여 전산모사방법을 이용하여 배출량을 예측하는 방법을 제시하였다. 예측된 값의 검증을 위하여 밸브, 플랜지 등의 비산배출원으로 구성되어 있는 실험장치를 고안하고 내부를 흐르는 유체의 종류 및 조건에 따른 배출량을 백포집법에 의해 샘플링하여 GC로 분석한 후, 분석된 데이터를 전산모사를 통해 얻은 결과와 비교하였다. 그 결과, 전산모사를 이용하여 밸브, 플랜지, 개방식라인으로부터 배출되는 벤젠과 톨루엔의 양을 예측할 수 있었다. Considerable effort and expense have been devoted to the estimation and acquisition of the amounts of VOCs relesed thousands of the fugitive emission sources installed in chemical processes. In order to reduce the effort required on the estimation of VOC release, a methodology using a computational fluid dynamics (CFD) was proposed. The estimated values were compared the experimental data obtained using a designed experimental apparatus that was composed of fugitive emission sources such as valves, pump, and flange. The emissions were sampling tedlar bags for a variety of volatile compounds at different pressures. The components were analyzed by a portable gas chromatograph. In conclusion, the amount of benzene and toluene released from fugitive emission sources could be successfully estimated using the CFD technique.

환경농업 시범마을 논에서 시비에 따른 무척추동물 개체 수 변화

한민수,신중두,나영은,이남종,박문희,김세근 한국환경농학회 2002 한국환경농학회지 Vol.21 No.2

논의 관리방법에 따른 수서생물상의 변동 양상을 파악하기 위하여 종합적인 환경농업기술 시범 2개 지역의 논 및 하천에서 주기적으로 조사 분석하였다. 논에서의 수서 무척추동물의 총 개체 수는 두 지역 모두 농가관행구에 비해 화학비료 토양검정 시비구에서 62% 이상 높았고 그 다음은 두 지역에서 서로 다르게 나타나 옥천의 경우 농가관행구, 양평은 화학비료+개량재 순으로 많고, 가장 적은 처리는 무비구였다. 수서곤충의 총 개체 수는 토양검정시비구가 농가관행구 옥천 및 양평 각각 328, 45.1/L보다 56%, 69% 더 많았다. 갑각류의 총 개체수는 옥천 지역에서는 토양검정 화학비료구> 화학 비료+개량제구> 농가관행구> 무비구 순으로 많았으며, 양평에서는 화학비료+개량제구>토양검정 화학비료>무비> 농가관행구 순으로서 과다 비료시용구인 농가관행구에서 가장 적었다. 두 지역의 논관류 하천에서 서식하는 수서 무척추동물은 59과 76종이 분류되었고, 미확인종이 14종으로 조사되었으며, 특히 물방개과 중 노란테 콩알 물방개 및 땅콩 콩알 물방개가 채집되었고 양평 지역에서는 날도래 종류가 다양하게 서식하고 있는 것으로 나타났다. 하천지류별 수서 무척추동물 서식밀도는 두 지역 모두에서 상류보다는 하류에서 밀도가 높았으며, 옥천의 연평균 성적에서도 하류에서 1300/0.09 ㎡로 최상류에 비해 172% 더 많은 밀도를 나타냈다. 친환경 농업 실천 2개 지역에서의 논 서식 수서 무척추동물 개체 수 조사 결과 일반관행 농가 논 91.1/L 보다 58% 더 많았다. This study was conducted to survey and identify kinds and population of the freshwater invertebrate fauna according to the managements of paddy rice fields at Ok-Chun and Yang-Pyung. The experiment was conducted in 4 paddy plots; conventional fertilization plot (CF), fertilization by prescription with soil testing with (ST+A) or without soil amendment (ST), and no fertilization as the control. In addition, the freshwater invertebrate fauna was also surveyed at 3 sections of as upper, intermediate and down, in both Jitan and Bungsan stream. The total number of the freshwater invertebrates was higher in the order of ST>CF>ST+A>C and ST>ST+A>CF>C at Ok-Chun and Yang-Pyung, respectively. The population density of aquatic insects was higher in plots fertilized by prescription with soid testing than in the other plots at both demonstration villages. The freshwater invertebrates collected in Jitan and Bungsan stream were identified and classified into 59 families and 90 species, and their population density was highest in the downstream among.

손가락 끝 점을 이용한 손 형상 인식

김종민,이웅기,장근실,양환석,허진경,박승규 朝鮮大學校 統計硏究所 2007 統計硏究所論文誌 Vol.9 No.1

최근 사용자 친화형 유저 인터페이스 구현을 위해 인간의 손 형상을 실시간으로 인식하는 연구의 중요성이 부각되고 있다. 그러나 인간의 손은 자유도가 크기 때문에 손 형상을 정확히 인식하기란 매우 어렵고 또한 피부색과 유사한 색을 가지는 복잡한 배경에서는 더욱 곤란하다. 본 논문에서는 별도의 센서를 부착하지 않고 카메라를 사용하여 피부색 정보에 의한 손 형상을 분할한 후 손가락 끝 점을 찾는다. 찾은 손가락 끝 점을 이용하여 방향을 탐지하는 알고리즘에 대해 기술한다. 이 방법은 템플리트 매칭을 이용하여 손가락 끝 점을 탐색한 후 찾은 손가락 끝 점과 손목의 중심을 이용하여 전, 후, 좌, 우 방향을 탐지한다. 제안하는 방법을 이용하여 3D 가상현실 공간에서의 네비게이션(Navigation)에 응용하였으며, 실험결과 전진, 후진 및 좌측, 우측의 방향전환도 매우 좋은 결과를 보였다. 또한 본 논문에서 제안하는 방법은 마우스, 키보드, 조이스틱 등의 조작 없이 전, 후, 좌, 우 방향전환을 사용자가 직관적으로 지시함으로써 보다 자연스러운 인간과 컴퓨터의 상호작용을 제공할 수 있을 것이다.

관상동맥색전증에 의한 급성심근경색증 4예

김민근,주혜원,강경필,최병돈,박민석,변영섭,고충원,이건주,김병옥 인제대학교 2006 仁濟醫學 Vol.27 No.-

Acute myocardial infarction(AMI) due to coronary embolism can occur in patients with normal coronary artery. Coronary embolism is believed to be a cause of acute myocardial infarction when emergent coronary angiography shows perfectly normal coronary trees, except for the finding of coronary artery occlusion. In this report, we describe four patients with AMI due to coronary embolism who were successfully treated using a thrombus aspiration device and anticoagulation, and those patients had intracardial thrombus arising from the left atrium due to chronic atrial fibrillation and valvular heart disease. Patients with chronic or paroxysmal atrial fibrillation can present with AMI due to coronary embolism, and thrombus aspiration with percutaneous aspiration device is a feasible treatment option for these patients along with anticoagulation the rapy.

수평유동장에서 난류증진을 위한 초음파 적용에 관한 연구

최우창,박영호,송민근,주은선 경상대학교 생산기술연구소 2000 生産技術硏究所論文集 Vol.16 No.-

A study on the application of ultrasonic vibration for the turbulence enhancement in a horizontal flow field was carried out by laying emphasis of the Reynolds numberand the ultrasonic incidence angle on the laminar flow field. A large water tank was made of the transparent acrylic plates and city water of 25℃ was used as working fluid. Angles of the ultrasonic oscillator such as 30°, 45° , 60° , 90° , 120° , 135° and 150° were selected and experiments for the above were made. Data, such as time mean velocity vector and time mean turbulent intensity which was obtained by PIV measurement, were examined, compared and discussed at Reynolds No. 2,000 and 4,000 to know the degree of turbulence enhancement in each case.

Laparoscopic repair of parastomal and incisional hernias with a modified Sugarbaker technique

Duck Hyoun Jeong,Min Geun Park1,George Melich2,Hyuk Hur,Byung Soh Min,Seung Hyuk Baik,Nam Kyu Kim 대한외과학회 2013 Annals of Surgical Treatment and Research(ASRT) Vol.84 No.6

A parastomal hernia is the most common surgical complication following stoma formation. As the field of laparoscopic surgery advances, different laparoscopic approaches to repair of parastomal hernias have been developed. Recently, the Sugarbaker technique has been reported to have lower recurrence rates compared to keyhole techniques. As far as we know, the Sugarbaker technique has not yet been performed in Korea. We herein present a case report of perhaps the first laparoscopic parastomal hernia repair with a modified Sugarbaker technique to be successfully carried out in Korea. A 79-year-old woman, who underwent an abdominoperineal resection for an adenocarcinoma of the rectum 9 years ago, presented with a large parastomal and incisional hernias, and was treated with a laparoscopic repair with a modified Sugarbaker technique. Six months after surgery, follow-up with the patient has shown no evidence of recurrence.