8 results on '"Ok-Kyun Kim"'
Search Results
2. Near-Infrared Light Emitting Diode Based Non-Invasive Glucose Detection System
- Author
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Ji-Hye Kim, Ok-Kyun Kim, Min-Seok Kim, Seung Ho Lee, and Hyung-Hwan Baik
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Materials science ,Biomedical Engineering ,Bioengineering ,02 engineering and technology ,law.invention ,law ,Diabetes Mellitus ,Humans ,General Materials Science ,Blood Glucose Measurement ,Spectroscopy ,Diode ,Spectroscopy, Near-Infrared ,business.industry ,Glucose meter ,Near-infrared spectroscopy ,General Chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Cuvette ,Wavelength ,Glucose ,Optoelectronics ,0210 nano-technology ,business ,Light-emitting diode - Abstract
Diabetes mellitus is a common disease that has affected people since antiquity. The complexity of diabetes mellitus lies in the fact that it requires continuous management in order to prevent serious complications. Various methods for managing diabetes mellitus through monitoring blood glucose levels have been studied and developed, and the most widely used method includes using an invasive blood glucose meter. Since the invasive blood glucose meter poses a major inconvenience for patients, in this study, we sought to develop a non-invasive blood glucose meter. We therefore proposed the development of a non-invasive blood glucose measurement system that is based on near-infrared spectroscopy. The system developed was composed of a light source for emitting different wavelengths, a light detector unit, and a computing system for recording signals. A prepared glucose solution was injected into a quartz cuvette and light at 780-1650 nm was emitted to pass through the cuvette. The degree of reaction was determined by recording the change in wavelength. The wavelength band used for the experiment was 780-1000 nm and the resolution was 20 nm. The glucose concentration was determined to be between 50 to 400 mg/dl compared to the normal range of 80 to 120 mg/dl. By examining which wavelength bands specifically reacted with glucose, we observed that the wavelength bands that decreased or increased in response to the glucose concentration were at 780 nm and 940 nm. For wavelength bands at 1000 nm or above, light was also absorbed by water and therefore it was difficult to distinguish the results. The most reliable wavelength band was at 940 nm with an R² of 0.9806. In conclusion, the near-infrared light emitting diode based non-invasive glucose detection system performed well and is expected to be a superior method for monitoring blood glucose levels in diabetes mellitus.
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- 2019
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3. Local-dependency of morphological and optical properties between breast cancer cell lines
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Ok-Kyun Kim, Sanghwa Lee, Jun Ki Kim, and Seung Ho Lee
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Cell ,Breast Neoplasms ,02 engineering and technology ,Microscopy, Atomic Force ,Spectrum Analysis, Raman ,01 natural sciences ,Analytical Chemistry ,Metastasis ,010309 optics ,symbols.namesake ,Nuclear magnetic resonance ,Breast cancer ,Cell Line, Tumor ,0103 physical sciences ,Biopsy ,Image Processing, Computer-Assisted ,medicine ,Medical imaging ,Humans ,skin and connective tissue diseases ,Instrumentation ,Spectroscopy ,Principal Component Analysis ,medicine.diagnostic_test ,Chemistry ,Cancer ,Signal Processing, Computer-Assisted ,021001 nanoscience & nanotechnology ,medicine.disease ,Atomic and Molecular Physics, and Optics ,medicine.anatomical_structure ,Cancer cell ,MCF-7 Cells ,symbols ,Female ,0210 nano-technology ,Raman spectroscopy - Abstract
Breast cancer is the most malignant type of cancer in women and is a global health problem, with mortality by metastasis being the main factor among others. Currently, detection and diagnosis of breast cancer is achieved through a variety of procedures, such as clinical examination, medical imaging, biopsy, and histopathological analysis. In contrast, spectroscopic analysis has a variety of advantages such as being noninvasive, not destroying biological materials, and not requiring additional histological analysis. In this study, various approaches using Raman spectroscopy, atomic force microscopy (AFM), and optical microscopy were used together to differentiate between and characterize normal breast cell lines (MCF-10A) and breast cancer cell lines (MDA-MB-231, MDA-MB-453). Raman spectra of normal breast cell and breast cancer cell lines confirmed visual differences in the concentrations of various compounds. These spectra were also analyzed using principle component analysis (PCA), and the PCA results showed reliable separation of the three cell lines and the cancer cell lines (MDA-MB-231, MDA-MB-453). With these results, optically synchronizing the AFM morphology, the Raman spectroscopy, and the visible RGB optical transmission intensity provided contrasts for not only conformational differences but also intracellular variation between the normal and cancer cell lines. We observed the inherent characteristic that there is no local difference in cancer cells regardless of morphology in a wide range of optical properties such as absorption, scattering and inelastic scattering.
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- 2018
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4. Anti-Inflammatory Effects of Step Electrical Stimulation on Complete Freund's Adjuvant (CFA) Induced Rheumatoid Arthritis Rats
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Hyung-Hwan Baik, Ok-Kyun Kim, Min-Seok Kim, Seung Ho Lee, Ji Hye Kim, and Ah-Ran Yu
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medicine.medical_specialty ,Materials science ,medicine.drug_class ,medicine.medical_treatment ,Freund's Adjuvant ,Biomedical Engineering ,H&E stain ,Anti-Inflammatory Agents ,Bioengineering ,Inflammation ,Stimulation ,02 engineering and technology ,Anti-inflammatory ,Arthritis, Rheumatoid ,Rats, Sprague-Dawley ,Mice ,Internal medicine ,medicine ,Animals ,General Materials Science ,Tumor Necrosis Factor-alpha ,General Chemistry ,Fibroblasts ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,medicine.disease ,Arthritis, Experimental ,Electric Stimulation ,Rats ,Endocrinology ,Rheumatoid arthritis ,Tumor necrosis factor alpha ,medicine.symptom ,Swelling ,0210 nano-technology ,Adjuvant - Abstract
Rheumatoid arthritis is a chronic inflammatory disease that affects joints and induces pain and swelling. We evaluated the anti-inflammatory effects of step electrical stimulation (SES) in this study. SES was carried out by increasing the voltage (3 V/s) from 5 V to 100 V for 60 cycles. The viability of mouse embryonic fibroblasts (NIH-3T3) was evaluated after step-electrical stimulation. After the injection of complete Freund's adjuvant (CFA) on the right hind paw of Sprague Dawley (SD) rats (6 weeks old), the degree of swelling was measured using a digital plethysmometer and Vernier caliper. Histological changes in inflamed tissues were observed with hematoxylin and eosin (H&E) staining, while the degree of inflammation was evaluated from the expression level of inflammatory factors such as cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6). As a result, we found no difference in cell viability after SES treatment between the control and SES-treated groups. On day 21 after CFA injection, the swelling of right hind paws decreased by 1.09 times in SES-treated group as compared with the untreated group. In addition, the levels of COX-2, TNF-α and IL-6 significantly decreased after SES treatment. Thus, SES treatment decreased paw swelling and alleviated inflammation.
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- 2019
5. Effects of prostaglandin E1 on nitric oxide and oxygen dynamics during rat myocardial ischemia–reperfusion utilizing sol–gel derived microsensors
- Author
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Jae Ho Shin, Bochan Seo, Sung Wook Kang, Young Ju Lee, Hun-Kuk Park, Ok Kyun Kim, Hyung Joon Ahn, and Gi-Ja Lee
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Cardioprotection ,Myocardial ischemia ,Metals and Alloys ,chemistry.chemical_element ,Vasodilation ,Critical limb ischemia ,Pharmacology ,Condensed Matter Physics ,Oxygen ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Nitric oxide ,Oxygen tension ,chemistry.chemical_compound ,chemistry ,Materials Chemistry ,medicine ,lipids (amino acids, peptides, and proteins) ,Electrical and Electronic Engineering ,medicine.symptom ,Prostaglandin E1 ,Instrumentation - Abstract
Prostaglandin E1 (Alprostadil ® , PGE1) is often used for patients with critical limb ischemia due to its vasodilator and anti-platelet effects. Although PGE1 is considered to have a cardioprotective effect against myocardial ischemia–reperfusion (IR) injury, its mechanism and correlation with nitric oxide (NO) for cardioprotection are not clear. In this study, we used sol–gel-modified electrochemical NO and O 2 microsensors to simultaneously measure the changes in NO level and oxygen tension ( p O 2 ) in the myocardium during myocardial IR that were induced by PGE1 pretreatment. Rat hearts were randomly divided into two groups: a control group ( n = 5) and a PGE1 group ( n = 5, with PGE1 pretreatment). Myocardium that underwent PGE1 pretreatment (26.0 ± 13.1%, p p n = 5). The restoration value of p O 2 in the PGE1 group significantly increased and was restored to pre-ischemic level (82.2 ± 21.3%); however, the p O 2 of the control group did not increase throughout the reperfusion period (12.3 ± 7.9%, p p O 2 dynamics in the myocardium would be effective in evaluating the effects of therapeutic treatments such as drug administration. Also, the reduction in excessive NO release during the early reperfusion period might be helpful as a therapeutic strategy to protect the myocardium from IR injury.
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- 2014
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6. Simultaneous, real-time measurement of nitric oxide and oxygen dynamics during cardiac ischemia–reperfusion of the rat utilizing sol–gel-derived electrochemical microsensors
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Gi-Ja Lee, Fu-Shi Quan, Sung Wook Kang, Bochan Seo, Sung Ho Lee, Jae Ho Shin, Hun-Kuk Park, and Ok Kyun Kim
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Male ,medicine.medical_specialty ,Time Factors ,chemistry.chemical_element ,Myocardial Reperfusion Injury ,Oxygen dynamics ,Endogeny ,Molecular Dynamics Simulation ,Nitric Oxide ,Biochemistry ,Oxygen ,Analytical Chemistry ,Nitric oxide ,Rats, Sprague-Dawley ,chemistry.chemical_compound ,Internal medicine ,medicine ,Animals ,Environmental Chemistry ,Myocardial infarction ,Spectroscopy ,Cardiac ischemia ,Electrochemical Techniques ,medicine.disease ,Rats ,Oxygen tension ,chemistry ,Cardiology ,Ischemic preconditioning ,Gels ,Microelectrodes - Abstract
In this study, we simultaneously measured nitric oxide (NO) and oxygen (O2) dynamics in the myocardium during myocardial ischemia-reperfusion (IR) utilizing sol-gel modified electrochemical NO and O2 microsensors. In addition, we attempted to clarify the correlation between NO release in the ischemic period and O2 restoration in the myocardium after reperfusion, comparing a control heart with a remote ischemic preconditioning (RIPC)-treated heart as an attractive strategy for myocardial protection. Rat hearts were randomly divided into two groups: a control group (n=5) and an RIPC group (n=5, with RIPC treatment). Myocardia that underwent RIPC treatment (182±70 nM, p
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- 2013
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7. Instantaneous Temperature Measuring System Design of Skin Tissue in Medical CO2 Laser Device with Power and Pulse Time Variation
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Ji Hye Kim, Hyung Hwan Baek, Sung Wook Kang, Ok Kyun Kim, and Kang Bo An
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Multidisciplinary ,Materials science ,business.industry ,Pulse (signal processing) ,Laser ,Signal ,law.invention ,Power (physics) ,Optics ,Operating temperature ,law ,Contact area ,business ,Intensity (heat transfer) ,Energy (signal processing) - Abstract
The purpose of the system design when using the CO2 laser beam to the contact area to prevent heat damage. Changes in output and the pulse of the laser to investigate the correlation between the temperature and Safe procedure, based on data detected by the temperature of the automatic return (control) system is proposed. First, the normal procedure of the rough as medical device approved for CO2 laser, Manufacturers for the purpose of presenting symptoms in the range of thermal damage, do not express. Second, users of the skin tissue when used to induce clotting, Confirmed by experiments. Irradiation time and energy in proportion to the intended expression of heat damage, but too much of the damage that can result. Third, the temperature detection data based on the detection of laser distance sensor and a non-contact could be infrared temperature detection sensor configuration. The operating temperature of the irradiation time and energy to set and the signal sent to control the intensity. As a result, the effect of CO2 laser of fine focus was confirmed that the change in focus in a distributed.
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- 2015
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8. Real time measurement of myocardial oxygen dynamics during cardiac ischemia–reperfusion of rats
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Jae Ho Shin, Joo-Ho Chung, Gi-Ja Lee, Su-Jin Chae, Ok-Kyun Kim, Samjin Choi, Seung Ki Kim, Sung Wook Kang, and Hun-Kuk Park
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Male ,medicine.medical_specialty ,Silver ,Time Factors ,Ischemia ,chemistry.chemical_element ,Myocardial Reperfusion Injury ,Oxygen dynamics ,Biochemistry ,Oxygen ,Analytical Chemistry ,Rats, Sprague-Dawley ,Internal medicine ,Electrochemistry ,medicine ,Animals ,Environmental Chemistry ,Electrodes ,Spectroscopy ,Platinum ,Chemistry ,Cardiac ischemia ,Silver Compounds ,Drug administration ,Electrochemical Techniques ,medicine.disease ,Pathophysiology ,Rats ,Oxygen tension ,Cardiology ,Peak level ,Gels - Abstract
Because oxygen plays a critical role in the pathophysiology of myocardial injury during subsequent reperfusion, as well as ischemia, the accurate measurement of myocardial oxygen tension is crucial for the assessment of myocardial viability by ischemia–reperfusion (IR) injury. Therefore, we utilized a sol–gel derived electrochemical oxygen microsensor to monitor changes in oxygen tension during myocardial ischemia–reperfusion. We also analyzed differences in oxygen tension recovery in post-ischemic myocardium depending on ischemic time to investigate the correlation between recovery parameters for oxygen tension and the severity of IR injury. An oxygen sensor was built using a xerogel-modified platinum microsensor and a coiled Ag/AgCl reference electrode. Rat hearts were randomly divided into 5 groups: control (0 min ischemia), I-10 (10 min ischemia), I-20 (20 min ischemia), I-30 (30 min ischemia), and I-40 (40 min ischemia) groups (n = 3 per group, respectively). After the induction of ischemia, reperfusion was performed for 60 min. As soon as the ischemia was initiated, oxygen tension rapidly declined to near zero levels. When reperfusion was initiated, the changes in oxygen tension depended on ischemic time. The normalized peak level of oxygen tension during the reperfusion episode was 188 ± 27 in group I-10, 120 ± 24 in group I-20, 12.5 ± 10.6 in group I-30, and 1.24 ± 1.09 in group I-40 (p < 0.001, n = 3, respectively). After 60 min of reperfusion, the normalized restoration level was 129 ± 30 in group I-10, 88 ± 4 in group I-20, 3.40 ± 4.82 in group I-30, and 0.99 ± 0.94 in group I-40 (p < 0.001, n = 3, respectively). The maximum and restoration values of oxygen tension in groups I-30 and I-40 after reperfusion were lower than pre-ischemic values. In particular, oxygen tension in the I-40 group was not recovered at all. These results were also demonstrated by TTC staining. We suggest that these recovery parameters could be utilized as an index of tissue injury and severity of ischemia. Therefore, quantitative measurements of oxygen tension dynamics in the myocardium would be helpful for evaluation of the cardioprotective effects of therapeutic treatments such as drug administration.
- Published
- 2012
- Full Text
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