韓日航路의 現況과 그 展望

金允錫 한국해사문제연구소 1974 (月刊)海洋韓國 Vol.15 No.-

Clinicopathologic Characteristics of Breast Cancer Stem Cells Identified on the Basis of Aldehyde Dehydrogenase 1 Expression

김윤석,이정한,정민정,류동원 한국유방암학회 2014 Journal of breast cancer Vol.17 No.2

Purpose: Breast cancer displays varying molecular and clinicalfeatures. The ability to form breast tumors has been shown byseveral studies with aldehyde dehydrogenase 1 (ALDH1) positivecells. The aim of this study is to investigate the association betweenALDH1 expression and clinicopathologic characteristics ofinvasive ductal carcinoma. Methods: We investigated breast cancertissues for the prevalence of ALDH1+ tumor cells and theirprognostic value. The present study included paraffin-embeddedtissues of 70 patients with or without recurrences. We appliedimmunohistochemical staining for the detection of ALDH1+ cells. Analysis of the association of clinical outcomes and molecularsubtype with marker status was conducted. Results: ALDH1+and ALDH1– tumors were more frequent in triple-negative breastcancers and in luminal A breast cancers, respectively (p<0.01). ALDH1 expression was found to exert significant impact on diseasefree survival (DFS) (ALDH1+ vs. ALDH1–, 53.1±6.7 monthsvs. 79.2±4.7 months; p=0.03) and overall survival (OS) (ALDH1+vs. ALDH1–, 68.5±4.7 months vs. 95.3±1.1 months; p<0.01). Intriple-negative breast cancer (TNBC) patients, DFS and OSshowed no statistical differences according to ALDH1 expression(ALDH1+ vs. ALDH1–, 45.3±9.4 months vs. 81.3±7.4 months,p=0.52; 69.0±7.5 months vs. 91.3±6.3 months, p=0.67). However,non-TNBC patients showed significant OS difference betweenALDH1+ and ALDH1– tumors (ALDH1+ vs. ALDH1–, 77.6±3.6 months vs. 98.0±1.0 months; p=0.04) with no statistical differenceof DFS (ALDH1+ vs. ALDH1–, 60.5±8.0 months vs. 81.8±4.6 months; p=0.27). Conclusion: Our findings suggest that theexpression of ALDH1 in breast cancer may be associated withTNBC and poor clinical outcomes. On the basis of our findings,we propose that ALDH1 expression in breast cancer could becorrelated with poor prognosis, and may contribute to a moreaggressive cancer phenotype.

국내 교량구조물의 공기력 진동제어

김윤석,박수영 한국풍공학회 2002 한국풍공학회지 Vol.6 No.2

Diagnostic value of magnetic resonance imaging using superparamagnetic iron oxide for axillary node metastasis in patients with breast cancer: a meta-analysis

김윤석,이루다,류동원,박정구 고신대학교(의대) 고신대학교 의과대학 학술지 2018 고신대학교 의과대학 학술지 Vol.33 No.3

Objectives: Identification of axillary metastases in breast cancer is important for staging disease and planning treatment, but current techniques are associated with a number of adverse events. This report evaluates the diagnostic accuracy of superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance imaging (MRI) techniques for identification of axillary metastases in breast cancer patients. Methods: We performed a meta-analysis of previous studies that compared SPIO enhanced MRI with histological diagnosis after surgery or biopsy. We searched PubMed, Ovid, Springer Link, and Cochrane library to identify studies reporting data for SPIO enhanced MRI for detection of axillary lymph node metastases in breast cancer until December 2013. The following keywords were used: “magnetic resonance imaging AND axilla” and “superparamagnetic iron oxide AND axilla”. Eligible studies were those that compared SPIO enhanced MRI with histological diagnosis. Sensitivity and specificity were calculated for every study; summary receiver operating characteristic and subgroup analyses were done. Study quality and heterogeneity were also assessed. Results: There were 7 publications that met the criteria for inclusion in our meta-analysis. SROC curve analysis for per patient data showed an overall sensitivity of 0.83 (95% Confidence interval (CI): 0.75-0.89) and overall specificity of 0.97 (95% CI: 0.94-0.98). Overall weighted area under the curve was 0.9563. Conclusions: SPIO enhanced MRI showed a trend toward high diagnostic accuracy in detection of lymph node metastases for breast cancer. So, when the breast cancer patients has axillary metastases histologically, SPIO enhanced MRI may be effective diagnostic imaging modality for axillary metastases.

Diagnostic Value of Elastography Using Acoustic Radiation Force Impulse Imaging and Strain Ratio for Breast Tumors

김윤석,박정구,김범수,이충한,류동원 한국유방암학회 2014 Journal of breast cancer Vol.17 No.1

Purpose: The aim of this study was to determine whether thecombination of B-mode ultrasonography (BUS), acoustic radiationforce impulse (ARFI) elastography, and strain ratio (SR) providesbetter diagnostic performance of breast lesion differentiationthan BUS alone. Methods: ARFI elastography and SR evaluationswere performed on patients with 157 breast lesions diagnosedby BUS from June to September 2013. BUS images wereclassified according to the Breast Imaging-Reporting and DataSystem. ARFI elastography was performed using Virtual Touch™tissue imaging (VTI) and Virtual Touch™ tissue quantification(VTQ). In VTI mode, we evaluated the color-mapped patterns ofthe breast lesion and surrounding tissue. The lesions were classifiedinto five categories by elasticity score. In VTQ mode, eachlesion was assessed using shear wave velocity (SWV) measurements. SR was calculated from the lesion and comparable lateralfatty tissue. We compared the diagnostic performance of BUSalone and the combination of BUS, ARFI elastography, and SRevaluations. Results: Among the 157 lesions, 40 were malignantand 117 were benign. The mean elasticity score (3.7±1.0 vs. 1.6±0.8, p<0.01), SWV (4.23±1.09 m/sec vs. 2.22±0.88 m/sec, p<0.01), and SR (5.69±1.63 vs. 2.69±1.40, p<0.01) were significantlyhigher for malignant lesions than benign lesions. The resultsfor BUS combined with ARFI elastography and SR valueswere 97.5% sensitivity, 92.3% specificity, 93.6% accuracy, a79.6% positive predictive value (PPV), and a 99.1% negative predictivevalue. The combination of the 3 radiologic examinationsyielded superior specificity, accuracy, and PPV compared to BUSalone (p<0.01 for each). Conclusion: ARFI elastography and SRevaluations showed significantly different mean values for benignand malignant lesions. Moreover, these two modalities complementedBUS and improved the diagnostic performance of breastlesion detection. Therefore, ARFI elastography and SR evaluationscan be used as complementary modalities to make moreaccurate breast lesion diagnoses.

딥러닝 모델 반응변수 구간 설정에 따른 성능 차이 연구

김윤석,태현철,박재상,서지훈 대한산업공학회 2021 대한산업공학회 춘계학술대회논문집 Vol.2021 No.6

Streptococcus mutans NCTC 10449 에서 생산된 Glucosyltransferase 의 정제 및 특성

김윤석,김여경,이기붕 한국미생물학회 1992 미생물학회지 Vol.30 No.3

Streptococcus mutans NCTC 10449 가 생산하는 Glucosyltransferase 를 순수 분리하고 그 특성을 조사하였다. 이 효소는 충치 형성 과정중 insoluble glucan 의 형성과 관련되어 있다. 이 효소의 분자량은 152,000 이며 최적 pH 와 온도는 각각 6.5 와 $35^{\circ}C$ 이며 중성이상의 pH 에서 산성에서보다 다소 안정하였다. 이 효소의 활성에 대한 Km 값은 48 mM 정도였고, 이 효소에 의해 생산된 insoluble glucan 은 타액으로 부터 분리된 균에 의해 생산된 insoluble glucan 보다 dextranase 에 의한 분해도가 높았다. Glucosyltransferase of Streptococcus mutans NCTC 10449 was purified and characterized. It relates with production of insoluble glucan in dental caries. The molecular weight was estimated to be 152.000. The optimum pH and temperature was 6.5 and $35^{\circ}C$. respectively. The enzyme was stable in alkaline pH. The Michaelis constants of the enzyme for releasing of fructose were 48 mM. Hydrolysis rate of insolut~le glucan by tlextranase was higher in S. mutuns NCTC 10449 than that of strains isolated from saliva.

쇄골 골절의 해부학적 유합 후 저 방사선량 3차원 견갑부 전산화단층촬영술을 통한 견갑골 운동장애 평가

김윤석,김정곤,황정택,심재찬,장석환 대한스포츠의학회 2019 대한스포츠의학회지 Vol.37 No.4

Purpose: Malunions after clavicle fractures are generally considered to cause scapular dyskinesis. This study aims to verify the incidence of scapular dyskinesis following anatomically reduced clavicle fracture and to verify the usefulness of low-dose three-dimensional (3D) scapular wing computed tomography (3D-scapula wing-CT) analysis. Methods: Twenty-four patients with mid-clavicle fracture and four patients with distal clavicle fracture were recruited. After anatomical reduction and bony union, scapular dyskinesis was assessed by history taking and physical examination by two orthopedic doctors. The mean follow-up period for the assessment was 14.3±10.1 months. Low-dose 3D-scapular wing-CT analysis in prone position was performed with calculated effective dose 2.35 mSv, which means approximately 25% dose of conventional setting. Four observers evaluated five angles (upward rotation, internal rotation, anterior tilting, superior translation, protraction) from 3D-reconstructed images on both shoulders of a patient. Authors analyzed the results between injured to normal shoulder. Results: Scapular dyskinesis or significant shortening of injured clavicle (mean clavicle length difference, −1.77±6.36 mm) were not observed among the included 28 subjects. The difference values of the five angles between the fractured side and normal side showed no statistical significance (upward rotation: 1.51, p=0.13; superior translation: 0.89, p=0.327; anterior tilting: 1.7, p=0.096; protraction: 0.83, p=0.374; internal rotation: 0.98, p=0.406). As the interclass correlation coefficients of four observers was 0.988 (p=0.00), images from low-dose 3D-wing-CT are clear enough to assess scapular dyskinesis (interclass correlation coefficient, 0.996; p=0.00). Conclusion: It is important to make anatomical reduction and length restoration of clavicle fracture for preventing scapular dyskinesis. Low-dose 3D-scapular wing-CT is an effective tool for assessing scapular dyskinesis, which provides images of sufficient quality with little increase in morbidity from radiation hazard.

ROS-responsive thioether-bearing polymers for efficient intracellular drug delivery in cancer cells

김윤석,Quan Hoang Truong,Giang Thuy Nguyen Cao,심민석 한국고분자학회 2019 한국고분자학회 학술대회 연구논문 초록집 Vol.44 No.1

우분 퇴비화의 주발효과정 중 이화학적 및 미생물학적 파라미터의 변화

김윤석,강명규,배경숙,이규승,이영하,Kim, Yoon Seok,Kang, Myoung Kyu,Bae, Kyung Sook,Lee, Kyu Seung,Rhee, Young Ha 한국미생물학회 1997 미생물학회지 Vol.33 No.4

Various physico-chemical and microbiological parameters of a composting system were compared with respect to their potential use for the monitoring and evaluation of composting processes for cattle manure. The temperature changed within a range of $30-65^{\circ}C$ during the whole composting process, and the period of active composting (>$40^{\circ}C$) persisted for 16 days. The concentrations of total carbon, total nitrogen, and organic matter decreased by 15% during active composting, but significant changes in C/N ratio were not observed. The decrease of temperature in the latter period of active composting caused a decrease of $NH_4^+-N$ and an increase of $NO_3^--N$ in the composting pile. When temperature exceeded $50^{\circ}C$, the population of thermophiles was higher than that of mesophiles by more than 1 or 2 orders of magnitude. Correlation analyses showed that amylase activity correlated positively with the population of mesophiles and reducing sugar content, but negatively with the population of thermophiles. Amylase activity was higher at the beginning of active composting, whereas cellulase, xylanase and ligninase activities which showed close relationship with each other, increased continually during active cornposting, suggesting the distinction of temporal niches between amylose-degrading and lignocellulose-degrading bacteria in the same habitat. 주재료와 부재료로서 각각 우분과 톱밥이 함유된 유기성 폐기물 퇴비화의 주발효과정 중 이화학적 및 미생물학적 파라미터의 변화양상을 조사하고, 이로부터 퇴비화의 평가에 이용할 수 있는 각 파라미터간의 상관관계를 분석하였다. 퇴비화 전과정동안 온도는 $30-65^{\circ}C$, pH는 7.5-9.5, 함수율은 50-60% 정도의 범위에서 변하였으며, 이 중 $40^{\circ}C$ 이상의 고온이 유지되는 주발효 기간은 약 16일 정도 지속되었다. 주발효 기간 중 시료내 총탄소, 총질소 및 유기물 함량은 모두 15% 이상 감소되었으나, C/N ratio는 뚜렷한 변화를 보이지 않았다. 주발효 후기에는 암모니아성 질소 함량이 급격히 감소하고 질산성 질소가 증가되는 경향이 나타났다. 미생물 군집내 중온균과 고온균의 개체수는 퇴비화 과정동안의 온도변화와 밀접한 관계를 보였다. 중온균은 $50^{\circ}C$ 이상의 고온발효 기간에 급격히 감소하다가 온도가 낮아지는 주발효 후기에 다시 증가하는 반면에, 고온균은 이와 반대의 변화를 보였으며 주발효 기간 중 고온균의 개체수는 중온균에 비하여 $10-10^2$배 높았다. 조사된 토양효소 중 amylase 활성은 중온균의 개체수 및 환원당량과 높은 양의 상관관계를, 고온균의 개체수와는 음의 상관관계를 나타냈다. 이와는 달리 상호 유의할만한 양의 상관관계를 보인 cellulase, xylanase 및 ligninase의 활성은 주발효 기간 중 지속적으로 증가하는 양상을 보임으로써, 주발효 기간 중 lignocellulose 분해미생물과 amylose 분해미생물간의 출현양상이 크게 다름을 보여 주었다.