Study on the Elastic Characteristics of Living Cells using Atomic Force Microscope Indentation Technique

Eun-Young Kwon,Young-Tae Kim,Dae-Eun Kim 한국트라이볼로지학회 2006 KSTLE International Journal Vol.7 No.1

In this work, imaging and study of elastic property of the living cell was performed. The motivation of this work was to seek the possibility of exploiting Young’s modulus as a disease indicator using Atomic Force Microscope (AFM) and also to gain fundamental understanding of cell mechanics for applications in medical nanorobots of the future. L-929 fibroblast adherent cell was used as the sample. Imaging condition in cell culturing media environment was done in very low speed (20 μm/s) compared to that in the ambient environment. For measuring the Young’s modulus of the living cell, AFM indentation method was used. From the force-distance curve obtained from the indentation experiment the Young’s modulus could be derived using the Hertz model. The Young’s modulus of living L-929 fibroblast cell was 1.29 ± 0.2 kPa.

AFM indentation 기법을 이용한 세포의 탄성특성에 관한 연구

권은영(Eun-Young Kwon),김영태(Young-Tae Kim),김대은(Dae-Eun Kim) 한국트라이볼로지학회 2006 한국트라이볼로지학회 학술대회 Vol.2006 No.6

In this work, imaging and investigation of elastic property of the living cell was performed. The motivation of this work was to seek the possibility of exploiting Young's modulus as a disease indicator using Atomic Force Microscope (AFM) and also to gain fundamental understanding of cell mechanics for applications in medical nanorobots of the future. L-929 fibroblast adherent cell was used as the sample. Imaging condition in cell culturing media environment was done in very low speed(20 ㎛/s) compare to that in ambient environment. For measuring the Young's modulus of the living cell, AFM indentation method was used. From the force-distance curve obtained from the indentation experiment the Young's modulus could be derived using the Hertz model. The Young's modulus of living L-929 fibroblast cell was 1.29 ± 0.2 kPa.

Study on the Elastic Characteristics of Living Cells using Atomic Force Microscope Indentation Technique

Kwon Eun-Young,Kim Young-Tae,Kim Dae-Eun Korean Tribology Society 2006 KSTLE International Journal Vol.7 No.1

In this work, imaging and study of elastic property of the living cell was performed. The motivation of this work was to seek the possibility of exploiting Young's modulus as a disease indicator using Atomic Force Microscope (AFM) and also to gain fundamental understanding of cell mechanics for applications in medical nanorobots of the future. L-929 fibroblast adherent cell was used as the sample. Imaging condition in cell culturing media environment was done in very low speed ($20{\mu}m/ s$) compared to that in the ambient environment. For measuring the Young's modulus of the living cell, AFM indentation method was used. From the force-distance curve obtained from the indentation experiment the Young's modulus could be derived using the Hertz model. The Young's modulus of living L-929 fibroblast cell was $1.29{\pm}0.2$ kPa.

Factors associated with the risk of colorectal neoplasia in young adults under age 40

Ilsoo Kim,Han Hee Lee,Young Jae Ko,Ho Eun Chang,Dae Young Cheung,Bo-In Lee,Young-Seok Cho,Jin Il Kim,Myung-Gyu Choi 대한내과학회 2022 The Korean Journal of Internal Medicine Vol.37 No.5

Background/Aims: Recent epidemiologic studies have shown a continued increase in colorectal cancer incidence among younger adults. Little is known about the factors that contribute to the development of young-onset colorectal neoplasia (CRN). Methods: A cross-sectional analysis was performed for individuals younger than 40 years who underwent colonoscopy in Seoul St. Mary’s Hospital and its affiliated health screening center. High-risk CRN was defined as adenoma or sessile serrated lesion ≥ 10 mm, with three or more adenomas, villous histology, high grade dysplasia, or carcinoma. Results: Of these 13,621 included participants, 2,023 (14.9%) had one and more CRN. Young patients with CRN tended to be elderly, male, obese, smoker, having a habit of drinking, and having comorbidities such as hypertension, dyslipidemia, diabetes, and chronic kidney disease. In a multivariate analysis adjusted for age, sex, obesity, smoking status, and alcohol intake, old age (odds ratio [OR], 1.086; 95% confidence interval [CI], 1.054 to 1.119), male sex (OR, 1.748; 95% CI, 1.247 to 2.451), obesity (OR, 1.439; 95% CI, 1.133 to 1.828), and smoking (OR, 1.654; 95% CI, 1.287 to 2.127) were independent risk factors for overall CRN. Obesity and smoking as two modifiable factors increased the risk for high-risk CRN even more than for overall CRN (OR, 1.734; 95% CI, 1.168 to 2.575 and OR, 1.797; 95% CI, 1.172 to 2.753, respectively). Conclusions: Obesity and smoking were modifiable risk factors for CRN in young adults. They increased the risk for highrisk CRN even more than for overall CRN. A colonoscopy might be beneficial for young individuals with these factors.

Communication, Argumentation and Relevance

Dae-Young Kim 한국언어학회 2014 언어 Vol.39 No.4

Kim, Dae-Young. 2014. Communication, Argumentation and Relevance. Korean Journal of Linguistics, 39-4, 719-748. The purpose of this paper is to argue that a theory of argumentation can be incorporated into a theory of communication (i.e. Relevance Theory). Whereas argumentation is the process of justifying something in an organized or a logical way, which is composed of one or more claims and shows one or more grounds for maintaining them, communication is sharing communicators’ intentions. A speaker’s conveying of his intention to hearer is to create an effect in the hearer’s mind. Two pragmatic theories, Relevance Theory (henceforth RT) and argumentation theory (henceforth AT) are involved in this approach, which is based on the position that communication is always accompanied with argumentation. However, RT has been more focused on explaining how the utterance is interpreted by the hearer, not how argumentation is performed. For this reason, this approach presented here argues for the needs to extend the scope of RT’s application. This integrated approach within a single principle of relevance ultimately contributes to pursuing a more economic and coherent explanation of argumentation. (Jeonju University)

Effects of Humidity on the Microstructure and the Ferroelectric Properties of Sol-Gel grown P(VDF-TrFE) Films

Young Joon Ko,진다운,Dae Sol Kong,Jong Hoon Jung 한국물리학회 2020 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.76 No.4

We report the microstructure and the ferroelectric properties of poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] films grown under various humidity conditions and synthesis times by using a sol-gel method. When the synthesis time under a humid condition was short (approximately 30 min), the moisture in the environment affected only the surface morphology without any loss of ferroelectricity for the P(VDF-TrFE) films. In contrast, when the synthesis time was long (approximately 90 min), the moisture strongly affected the microstructure and the ferroelectric properties of P(VDF-TrFE). The transparent P(VDF-TrFE) film became opaque at high humidity. Scanning electron microscopy revealed numerous pores on the surface of and inside the film. The pores reduced the Young's modulus considerably from 4.15 to 0.97 GPa for the films grown at 20 and 80% relative humidity, respectively. In addition, the ferroelectric hysteresis loop disappeared at humidities above 60%. This work provides upper limits for the humidity and the synthesis time for the growth of high-quality P(VDF-TrFE) films by using a sol-gel method.

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.

만선신부전 환자에서 관상동맥조영술 소견에 관한 연구

한대희,김성구,박상호,김성한,조원영,방덕원,조윤행,정의룡,은영근,권영구 순천향의학연구소 2003 Journal of Soonchunhyang Medical Science Vol.9 No.1

Background : Patients with chronic renal fialure have a substantially elevated risk of death from cardiovascular diseases than do the general population. the patients with chronic renal failure are at significantly increased freqeuncy of hypertension, hyperlipidemia, and diabetes mellitus which are known to the risk factors of the coronary artery diseases, and the prevalence of the coronary artery diseases in chronic renal failure patients is highly associated with the hemodynamic disorder and metabolic abnormalities. therefore we expected that the coronary angiographic findings in patients with chronic renal failure should be different from the general population (control groups) and investigated the risk factors contributing to coronary artery diseases. Method : we have retrospectively compared the coronary angiographic findings of 44 patients with chronic renal failure on hemodialysis with that of 88 patients in the general population and investigated the factors contributing to the development and acceleration of coronary artery diseases in patients with chronic renal failure Result : Hypertension and diabetes mellitus which is risk factors for coronary artery disease is significantly increased in patients with chronic renal failure, in coronary angiographic finding the severity of the lesion is worse. the incidence of PCI or CABG of patients with chronic renal failure is more than that of control group but statistically no difference between patients with chronic renal failure and control group. the sex, the duration of disease, the duration of dialysis, serum creatinine in patients with chronic renal failure have no correlation to the prevalence of coronary artery disease and severity of lesion. hyperglycemic patients with chronic renal failure have high incidence of coronary artery disease and are worse in the severity of lesion Conclusions : There is significantly increased the pevalence and severity of involving multiple coronary artery diseses in hyperglycemic patients with CRF.

1~2기 본태성 고혈압 환자들에서 Imidapril 대 Enalapril의 항고혈압 효과를 평가하기 위한 무작위, 이중맹검 임상시험

최영진,손대원,김용진,이홍자,채인호,김효수,김철호,오병희,이명묵,박영배,채윤식,이영우 대한순환기학회 1999 Korean Circulation Journal Vol.29 No.11

충청지방에서 발생한 한국형출혈열 54예의 임상적 고찰

이종대,조항복,박붕연,심우익,신영태,김선영 충남대학교 의과대학 지역사회의학연구소 1985 충남의대잡지 Vol.12 No.2

In Dae Jeon Eul-Ji General Hospital, activated since 1581, 54 patients with Korean Hemorrhagic Fever Who were all positive for Korea antigen were observed from January, 1981 to December, 1984. Epidemiology, clinical features, laboratory findings, complications and clinical course in Korean Hemorrhagic Fever were analyzed. The results were as follows: 1. The most prevalent area was OK-Chun Kun. 2. The peak incidence of age was fifth decade and male to female ratio was 2:1. 3. The peak incidence was November to December. 4. The most frequent symptomes were epigastric pain, nausea and vomiting and followed by hemsturia. 5. Conservative treatment was done and hemodialysis was performed in 19 patients without death.