• 동의생리병리학회지
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• 제16권2호
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• pp.353-358
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• 2002

To test the protective effect of herbal medicine against oxygen free radical-induced myocardiotoxicity, cytotoxicity of xanthine oxidase/hypoxanthine (XO/HX) was examined using MTT, TBARS, and beating rate assay in the presence of water extract of Sujeom-san(SJS) or single consituents of its prescription. Myocardial toxicity was evaluated in neonatal rat myocardiocytes in cultures. In the present paper, XO/HX resulted in a decrease in viability and beating rate and increases in lipid peroxidation in cultured myocardial cells. In the effect of SJS water extract, it showed effects from the cardiocytotoxicity induced by XO/HX treatment such as increases in beating rate and decreases in lipid peroxidation. In the effect of Rhizoma Corydalis (RC), Faeces Trogopterori (FT), Fructus Amomi Tsaoko (FAT) and Myrrha on the cardiocytotoxicity, they were significantly effective in blocking the XO/HX-induced cardiocytotoxicity by increase of beating rate in FAT and FT group as well as decrease of lipid peroxidation in FT and RC group. These results show that oxygen free radical elicits toxic effects in cultured myocardial cells derived from neonatal rat, and suggest that water extract of Sujeomsan, Rhizoma Corydalis, Faeces Trogopterori, Fructus Amomi Tsaoko or Myrrha is very effective in the prevention of xanthine oxidase/hypoxanthine- induced cardiotoxicity.

• Macromolecular Research
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• 제12권6호
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• pp.545-552
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• 2004

The long-term stability of sulfonic acid-containing polyimides has been investigated. The hydrolytic degradation of homopolyimide and the block copolyimide comprising $27\;mol\%$ of 2,2'-bis(trifluoromethyl)benzidine and $9\;mol\%$ of m-phenylenediamine (BTFMB27mPl0[7/(3+1)]), was quantified through viscosity measurements and FT-IR spectroscopic analyses. The viscosity decrease with respect to time and the degradation rate were similar. The degrees of degradation with respect to time under ambient conditions and at elevated temperature in water were monitored by FT-IR spectroscopy. A new absorption peak was observed at $1786\;cm^{-1},$ which we corresponds to the presence of anhydride end groups formed by hydrolytic scission of the imide rings.

• Asian-Australasian Journal of Animal Sciences
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• 제18권9호
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• pp.1242-1248
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• 2005

This study was designed to investigate the in vitro developmental ability and apoptosis of bovine embryos nucleartransferred (NT) with frozen-thawed or cooled donor cells. Cultured adult bovine ear cells were used as donor cells after sub-culturing to confluence (CC), cooling to 4$^{\circ}C$ for 48 h, or freezing-thawing (FT). Apoptotic cells in blastocysts were evaluated for apoptosis by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) method. Fusion, cleavage and blastocyst rates were 69.0 (167/242), 68.8 (115/167), and 29.9 (50/167) with CC cells, 70.4 (88/125), 69.3 (61/88), and 29.6 (26/88) with cooled cells and 66.1 (117/177), 70.1 (82/117), and 13.7 (16/117) with FT cells, respectively. Blastocyst rates of NT embryos derived from FT cells were significantly lower than those from CC or cooled cells (p<0.05). In addition, NT blastocysts produced by using FT cells showed significantly higher apoptosis rates (6.4${\pm}$4.0%) than those produced by CC (2.8${\pm}$1.7%) or cooled (2.3${\pm}$1.3%) cells. However, cooling of donor cells had no significant adverse effect on blastocyst rate as well as apoptosis rate. Therefore, our results suggest that cooled cells may be used as an alternative to freshly cultured confluent culture cells, as donor cells, for the production of Somatic nuclear cloned cattle.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVII)
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• pp.860-863
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• 2005

The microcapsules containing fragrant oil as functional material were prepared by in-situ polymerization with prepolymer that was made from melamine-formaldehyde (MF) as wall material of microcapsules. The effects of polymerization variables, such as the nature and concentration of surfactants, stirring rate, and stirring time, on the size and distribution of the particles were investigated. Fourier transform-infrared spectroscopy (FT-IR), thermal analysis, particle size analysis, scanning electron microscopy (SEM) observation were used to investigate the characteristics of microcapsules. Through the FT-IR and SEM analysis, we found that the prepared microcapsules were containing fragrant oil and the shape of particle was spherical. The nature and concentration of surfactants, stirring rate, and stirring time had profound effects on the particle size and particle size distribution.

• 한국재료학회지
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• 제33권11호
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• pp.458-464
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• 2023

In order to develop catechin patches for skin regeneration at wound sites, patches with varying concentrations of catechin and chitosan were manufactured. An optimal composition ratio was determined by adjusting the drug release rate and amount, to maximize efficiency. The catechin used in this study was extracted from green tea leaves using a solvent/ultrasonication method, and its characteristics were confirmed through Fourier transform-infrared spectroscopy (FT-IR) and high-performance liquid chromatography (HPLC) analyses. Patches were prepared with different concentrations of catechin and chitosan, and various properties were analyzed using techniques such as FT-IR, water contact angle analysis, and UV-Vis spectroscopy. It was observed that as the chitosan concentration increased, the release of catechin slowed down or almost ceased. A patch manufactured with 1.5 mg/cm² of catechin at a 1 % chitosan concentration exhibited a high initial release rate over 24 h and demonstrated cellular biocompatibility. Consequently, these patches, with tailored release characteristics based on the concentrations of chitosan and catechin, hold promise for use as drug delivery systems in wound healing applications.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.236-236
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• 2011

Silicon oxynitride (SiON) was deposited for gas barrier film on polyethylene terephthalate (PET) using octamethylycyclodisiloxane (Si4O4C8H24, OMCTS) precursor by plasma enhanced chemical vapor deposition (PECVD) at low temperature. The ion flux and substrate temperature were measured by oscilloscope and thermometer. The chemical bonding structure and barrier property of films were characterized by Fourier transform infrared (FT-IR) spectroscopy and the water vapor transmission rate (WVTR), respectively. The deposition rate of films increases with RF bias and nitrogen dilution due to increase of dissociated precursor and nitrogen ion incident to the substrate. In addition, we confirmed that the increase of nitrogen dilution and RF bias reduced WVTR of films. Because, on the basis of FT-IR analysis, the increase of the nitrogen gas flow rate and RF bias caused the increase of the C=N stretching vibration resulting in the decrease of macro and nano defects.

• 대한치과의사협회지
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• 제19권6호통권145호
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• pp.535-540
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• 1981

In order to collect the basic data for planning school dental health programmes, the author had examined dental health conditions of 120 males and 120 females of Changgyung Primary School children in the first grade. The percentages of persons with conditions requiring immediate attention, toothbrushing times and daily frequency, df rate, df index, dt index, ft index, it index, DMF rate, DT index, MT index, FT index, IT index, DMFT index, percentages of persons with periodontal status in every of the four categories with soft deposits, calculus, intense gingivitis, and advanced periodontal involvement were calculated and evaluated. The obtained results were as follows: 1. Persons with requiring immediate attention was 7.1% of all the examined children. 2. The df rate was 88.3%, and df index was 3.4 teeth per person. And then the DMF rate was 17.1%, while DMFT index was 0.3 teeth per person. 3. As the periodontal status, the persons with soft deposits was 90.0% of children, calculus 26.3%, intense gingivitis 0.4%, and no advanced periodontal involvement. 4. Average toothbrushing frquency was 1.2 times in a day per person. But 71.5% of toothbrushing was performed before meals, while the others after meals.

• 접착 및 계면
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• 제2권3호
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• pp.16-24
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• 2001

포름알데히드/페놀의 몰비에 따른 레졸과 노블락 수지의 경화거동을 FT-IR 분석법으로 연구하였다. 일정한 경화온도(레졸 수지: $130^{\circ}C$, $160^{\circ}C$, $180^{\circ}C$, 노블락 수지: $160^{\circ}C$, $170^{\circ}C$, $180^{\circ}C$)에서 경화시간(3, 5, 7, 10, 20, 60분)에 따른 경화 정도를 비교하였다. 경화정도(conversion, ${\alpha}$)는 경화되지 않은 수지의 FT-IR 스펙트라 $3300cm^{-1}$에 나타나는 OH 피크의 면적을 기준으로 각각 주어진 경화시간의 OH 피크 면적 비율로 구하였다. 그 결과 포름알데히드/페놀의 몰비와 경화 온도가 증가함에 따라서 레졸과 노블락 수지의 초기 경화는 증가하였다. 특정한 경화 온도에서 integral method 분석에 의한 결과 포름알데히드/페놀의 몰비가 증가함에 따라서 레졸과 노블락 수지의 초기 경화는 증가하였다.

• 한국운동역학회지
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• 제25권1호
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• pp.85-94
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• 2015

Purpose : The purpose of this study was to investigate the influence on the ground reaction force parameters according to wearing positions of backpack for during stair ascending and descending. Methods : Participants selected as subject were consisted of young female(n=10) and performed stairs walks(ascending and descending) with 2 types of wearing position(front of trunk[FT], rear of trunk[RT]). Passive(Fz 1) and active(Fz 2) forces of the vertical GRF were determined from time function and frequency domain. Also shear forces(Fx, Fy 1, Fy 2), dynamic postural stability index(MLSI, APSI, VSI, DPSI), loading rate and center of pressure (${\Delta}COPx$, ${\Delta}COPy$, COP area) were calculated from time function and frequency domain. Results : Fx, Fy 1, Fy 2, and Fz 1 in GRF didn't show significant differences statistically according to the wearing positions of backpack(p>.05), but stair descending showed higher forces than that of stair ascending. Particularly, Fz 2 of stair ascending showed higher forces than that of stair descending(p<.001), RT types showed higher than that of FT types(p<.05). MLSI, APSI, VSI, and DPSI of stair descending showed the increased stability index than that of stair ascending(p<.05), MLSI of RT types showed the decreased stability index than that of FT types(p<.05). Loading rate didn't show significant differences statistically according to the wearing positions of backpack(p>.05), but stair descending showed higher loading rate than that of stair ascending(p<.001). Also, ${\Delta}COPx$ in stair descending showed the increased movement than that of stair ascending(p<.05). Conclusions : A backpack of 10 kg(10 kg(ratio of body weights $17.61{\pm}1.17%$) showed significantly change GRF parameters according to wearing positions during stair ascending and descending. If possible, we suggest that the dynamic stability, in case of stairs walking with a smaller weights can be further improved.

• 한국멀티미디어학회논문지
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• 제9권3호
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• pp.323-332
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• 2006

실시간 멀티미디어 응용의 서비스 품질을 보장하는 공정 패킷 스케줄링 알고리즘은 타임스탬프 계산시 사용되는 패킷의 기준시각 측면에서 종료시각 방식과 시작시각 방식으로 나된다. 전자는 트래픽 흐름의 속도에 반비례하는 레이턴시 특성으로 인해 트래픽 흐름의 예약속도 조정으로 다양한 지연규격을 지원할 수 있어 대부분의 스케줄러에 적용되고 있으나 과잉예약에 따른 대역폭 손실이 발생한다. 반면 후자는 과잉예약에 따른 대역폭 손실은 없으나 흐름의 수에 종속되는 레이턴시 특성으로 인해 다수의 지연규격을 수용하기 어려운 문제점이 있다. 본 논문에서는 다수 지연규격(multiple delay bounds)을 효과적으로 지원할 수 있는 시작시각 기반 공정 패킷 스케줄러를 제안하고, 제안된 스케줄러의 성능특성을 분석한다. 분석결과 종료시각 기반 스케줄러보다 최대 30% 높은 이용도 특성을 보였다.