[논문]Operational Characteristics of CO2 Laser Adopted by Superposing-Discharge

Hee-Je Kim,Hyun-Ju Chung,Byoung-Dae Min,Jong-Han Joung,Sung- lun Park 釜山大學校生産技術硏究所 2003 生産技術硏究所論文集 Vol.62 No.-

오늘날 현저한 CO2 레이저의 응용 추세에 발맞추어 보다 다양한 형태의 출력 제어 기술이 대두되고 있다. 본연구에서는multi-Pulse Superposing-Discharge 기술을 이용하여 다양한형태의 CO2 레이저의 펄스를 성형 하였다. 펄스 성형을 위한 방법으로 PIC one-chip microprocessor를 이용하여 삼중 PFN 모률의 SCR을 각각 고유의 지연시간을 가지도록 제어하였다. 실험에 사용된 삼중 PFN 모률의 전원 회로는 각각 캐패시터 인덕터,SCR,고압 펄스 트랜스 그리고 고압 트랜스 2차측에 브릿지 정류기로 구성 하였다. 고압 펼스 트랜스의 1차측을 제어하므로서 PFN 모률의 동작을 저 전압에서 수행 할 수 있다. 트랜스의 2차측에 연결된 전파 정류기는 펄스 에너지를 부하에 지속적으로 전달한다. 본 연구에서는 삼중 PFN 모률의 각각의 SCR을 다른 시간 가격을 두고 트리거 하므로서 다양한 Long pulse shaping을 실현하였다. 또한 약 250-1000μs 의 주기를 가지는 다양한 펄스형 레이저 빔을 얻었다.

Accuracy of cardiac output measurements during off-pump coronary artery bypass grafting: according to the vessel anastomosis sites

Sung Yong Park,Dae Hee Kim,Han Bum Joe,Ji Young Yoo,Jin Soo Kim,Min Kang,Yong Woo Hong 대한마취통증의학회 2012 Korean Journal of Anesthesiology Vol.62 No.5

Background: During beating heart surgery, the accuracy of cardiac output (CO) measurement techniques may be influenced by several factors. This study was conducted to analyze the clinical agreement among stat CO mode (SCO), continuous CO mode (CCO), arterial pressure waveform-based CO estimation (APCO), and transesophageal Doppler ultrasound technique (UCCO) according to the vessel anastomosis sites. Methods: This study was prospectively performed in 25 patients who would be undergoing elective OPCAB. Hemodynamic variables were recorded at the following time points: during left anterior descending (LAD) anastomosis at 1 min and 5 min; during obtuse marginal (OM) anastomosis at 1 min and 5 min: and during right coronary artery (RCA) anastomosis at 1 min and 5 min. The variables measured including the SCO, CCO, APCO, and UCCO. Results: CO measurement techniques showed different correlations according to vessel anastomosis site. However, the percent error observed was higher than the value of 30% postulated by the criteria of Critchley and Critchley during all study periods for all CO measurement techniques. Conclusions: In the beating heart procedure, SCO, CCO and APCO showed different correlations according to the vessel anastomosis sites and did not agree with UCCO. CO values from the various measurement techniques should be interpreted with caution during OPCAB. Background: During beating heart surgery, the accuracy of cardiac output (CO) measurement techniques may be influenced by several factors. This study was conducted to analyze the clinical agreement among stat CO mode (SCO), continuous CO mode (CCO), arterial pressure waveform-based CO estimation (APCO), and transesophageal Doppler ultrasound technique (UCCO) according to the vessel anastomosis sites. Methods: This study was prospectively performed in 25 patients who would be undergoing elective OPCAB. Hemodynamic variables were recorded at the following time points: during left anterior descending (LAD) anastomosis at 1 min and 5 min; during obtuse marginal (OM) anastomosis at 1 min and 5 min: and during right coronary artery (RCA) anastomosis at 1 min and 5 min. The variables measured including the SCO, CCO, APCO, and UCCO. Results: CO measurement techniques showed different correlations according to vessel anastomosis site. However, the percent error observed was higher than the value of 30% postulated by the criteria of Critchley and Critchley during all study periods for all CO measurement techniques. Conclusions: In the beating heart procedure, SCO, CCO and APCO showed different correlations according to the vessel anastomosis sites and did not agree with UCCO. CO values from the various measurement techniques should be interpreted with caution during OPCAB.

Artificial Shrinkage Improves Survival and Embryonic Quality of Vitrified Bovine Blastocysts Derived from IVF and SCNT

Sung-Hun Min,Joo-Hee Hong,Humdai Park,Deog-Bon Koo 한국동물생명공학회(구 한국동물번식학회) 2011 발생공학 국제심포지엄 및 학술대회 Vol.2011 No.1

Freezing of bovine blastocysts has been proposed as a tool to improve the feasibility of cattle production by using embryo transfer technique. However, the low efficiency of frozen-thawed embryos survival and further development is a crucial problem. Thus, we examined the effect of artificial shrinkage before vitrification of bovine expanded, hatched and SCNT embryos on the survival rate, apoptosis index and further development after thawing. Expanded, hatched and SCNT embryos were vitrified after artificial shrinkage, which was performed by puncturing the blastocoele with a pulled pasteur pipet. Artificial shrinkage of the blastocyst was achieved after pushing a pulled pasteur pipet into the blastocoele cavity until it contracted. The shrunken and not shrunken embryos were exposed to cryoprotectant solution in 7.5% ethylene glycol-7.5% DMSOPBS with 20% FBS for 5 min. They were placed in a small volume of vitrification solution (15% ethylene glycol+15% DMSO+PBS+20% FBS+0.5 M sucrose) and plunged into liquid nitrogen on a cryotop. Then, after thawing, cryoprotectant was diluted in 1.0 M, 0.5 M, 0.25 M, and 0 M sucrose for 1, 3, 5, and 5 min. Under the optimal conditions, overall efficiency of the survival rate of bovine expanded, hatched, SCNT embryos in artificial shrinkage groups was higher compared with non-artificial shrinkage groups (p< 0.05). Especially, the numbers of TUNEL-positive nuclei in artificial shrinkage groups were significantly reduced than those of non-artificial shrinkage groups among frozen-thawed expanded, hatched, and SCNT blastocysts (p< 0.05). Our results showed that survival rates in cryopreserved expanded, hatched, SCNT embryos could be improved by reducing the fluid content. Therefore, we suggest that artificial shrinkage method is a effective pretreatment technique for the cryotop vitrification of expanded, hatched, SCNT bovine blastocysts.

Effects of Ethanol Addition on the Efficiency of Subcritical Water Extraction of Proteins and Amino Acids from Porcine Placenta

Sung Hee Park,Jae Hyeong Kim,Sang Gi Min,Yeon Ji Jo,Ji Yeon Chun 한국축산식품학회 2015 한국축산식품학회지 Vol.35 No.2

In a previous study, hydrolysates of porcine placenta were obtained and the extraction efficiency for proteins and amino acids was compared between sub- and super-critical water extraction systems; optimum efficiency was found to be achieved using subcritical water (170°C, 10 bar). In this study, the effects of adding ethanol to the subcritical water system were investigated. The lowest-molecular-weight extraction product detected weighed 434 Da, and the efficiency of extraction for low-molecular-weight products was increased when either the concentration of ethanol was decreased, or the extraction time was lengthened from 10 min to 30 min. The highest concentration of free amino acids (approximately 8 mM) was observed following 30 min extraction using pure distilled water. The concentration of free amino acids was significantly lower when ethanol was added or a shorter extraction time was used (p<0.05). Color change of the solution following extraction was measured. There were no significant differences in color between lysates produced with different extraction times when using distilled water (p>0.05); however, using different extraction times produced significant differences in color when using 20% or 50% ethanol solution for subcritical extraction (p<0.05). The range of pH for the hydrolysate solutions was 6.4-7.5. In conclusion, the investigated extraction system was successful in the extraction of ≤ 500 Da hydrolysates from porcine placenta, but addition of ethanol did not yield higher production of low-molecular-weight hydrolysates than that achieved by DW alone.

A chemically regenerative redox fuel cell using (2,2,6,6-tetramethylpiperidin-1-yl)oxyl redox reaction in acid medium

Han, Sang-Beom,Kwak, Da-Hee,Park, Hyun Suk,Park, Jin-Young,Ma, Kyeng-Bae,Won, Ji-Eun,Kim, Do-Hyoung,Kim, Min-Cheol,Park, Kyung-Won Elsevier 2018 Journal of Power Sources Vol.393 No.-

<P><B>Abstract</B></P> <P>(2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) with no free radical and non-volatile characteristic can be utilized as a liquid catalyst instead of O<SUB>2</SUB> at the cathode in a chemical regenerative redox fuel cell with H<SUB>2</SUB> as a fuel at the anode. In this study, the electrochemical properties and performance of TEMPO dissolved in sulfuric acid solution are investigated using half and unit cells. In the half-cell, TEMPO shows an activation energy of 1.27 kcal mol<SUP>−1</SUP> K<SUP>−1</SUP> for the reduction. A chemical regenerative redox fuel cell (CRRFC) using TEMPO as the liquid catalyst exhibits an open circuit voltage of 0.7 V and a maximum power density of 90 mW cm<SUP>−2</SUP> at 30 °C with a low activation loss. The regeneration cycling test of the CRRFC is performed at a constant voltage of 0.4 V under a flow rate of the oxygen-bubbled TEMPO solution. The performance of the CRRFC deteriorates, i.e., a power density of zero measured at >200 min. Thus, a highly efficient regeneration system needs to be developed for a high-performance CRRFC using TEMPO used as a liquid-type oxidant. Furthermore, stable liquid oxidants with relatively high standard reduction potentials can be proposed through various organic compounds.</P> <P><B>Highlights</B></P> <P> <UL> <LI> CRRFC was proposed using TEMPO instead of O<SUB>2</SUB> at the cathode. </LI> <LI> TEMPO showed fairly fast transport and low activation energy for the reduction. </LI> <LI> CRRFC exhibited an open circuit voltage of ∼0.7 V at 30 °C. </LI> <LI> CRRFC exhibited a maximum power density of ∼90 mW cm<SUP>−2</SUP> at 30 °C. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Surface Modification of Block Copolymer Through Sulfur Containing Plasma Treatment

Choi, Sang Wook,Shin, Jae Hee,Jeon, Min Hwan,Mun, Jeong Ho,Kim, Sang Ouk,Yeom, Geun Young,Kim, Kyong Nam American Scientific Publishers 2015 Journal of Nanoscience and Nanotechnology Vol.15 No.10

<P>Some of the important issues of block copolymer (BCP) as an application to the potential low cost next generation lithography are thermal stability and deformation during pattern transfer process in addition to defect density, line edge/width roughness, etc. In this study, sulfur containing plasma treatment was used to modify the BCP and the effects of the plasma on the properties of plasma treated BCP were investigated. The polystyrene hole pattern obtained from polystyrene polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) was initially degraded when the polystyrene hole was annealed at 190 degrees C for 15 min. However, when the hole pattern was treated using sulfur containing plasmas using H2S or SF6 up to 2 min, possibly due to the sulfurization of the polystyrene hole surface, no change in the hole pattern was observed after the annealing even though there is a slight change in hole shapes during the plasma treatment. The optimized plasma treated polystyrene pattern showed the superior characteristics as the mask layer by showing better thermal stability, higher chemical inertness, and higher etch selectivity during plasma etching.</P>

Involvement of calcium-mediated apoptotic signals in H₂O₂-induced MIN6N8a cell death

Choi, Sung-E,Min, Se-Hee,Shin, Ha-Chul,Kim, Hyo-Eun,Jung, Min Whan,Kang, Yup Elsevier 2006 european journal of pharmacology Vol.547 No.1

<P><B>Abstract</B></P><P>Reactive oxygen species are believed to be the central mediators of beta-cell destruction that leads to type 1 and 2 diabetes, and calcium has been reported to be an important mediator of beta cell death. In the present study, the authors investigated whether Ca<SUP>2+</SUP> plays a role in hydrogen peroxide (H<SUB>2</SUB>O<SUB>2</SUB>)-induced MIN6N8a mouse beta cell death. Treatment with low concentration H<SUB>2</SUB>O<SUB>2</SUB> (50?μM) was found to be sufficient to reduce MIN6N8a cell viability by 55%, largely via apoptosis. However, this H<SUB>2</SUB>O<SUB>2</SUB>-induced cell death was near completely blocked by pretreatment with BAPTA/AM (5?μM), a chelator of intracellular Ca<SUP>2+</SUP>. Moreover, the intracellular calcium store channel blockers, such as, xestospongin c and ryanodine, significant protected cells from 50?μM H<SUB>2</SUB>O<SUB>2</SUB>-induced cell death and under extracellular Ca<SUP>2+</SUP>-free conditions, 50?μM H<SUB>2</SUB>O<SUB>2</SUB> elicited transient [Ca<SUP>2+</SUP>]<SUB>i</SUB> increases. In addition, pharmacologic inhibitors of calpain, calcineurin, and calcium/calmodulin-dependent protein kinase II were found to have a protective effect on H<SUB>2</SUB>O<SUB>2</SUB>-induced death. Moreover, H<SUB>2</SUB>O<SUB>2</SUB>-induced apoptotic signals, such as c-JUN N-terminal kinase activation, cytochrome <I>c</I> release, caspase 3 activation, and poly (ADP-ribose) polymerase cleavage were all down-regulated by the intracellular Ca<SUP>2+</SUP> chelation. These findings show that [Ca<SUP>2+</SUP>]<SUB>i</SUB> elevation, possibly due to release from intracellular calcium stores and the subsequent activation of Ca<SUP>2+</SUP>-mediated apoptotic signals, critically mediates low concentration H<SUB>2</SUB>O<SUB>2</SUB>-induced MIN6N8a cell death. These findings suggest that a breakdown of calcium homeostasis by low level of reactive oxygen species may be involved in beta cell destruction during diabetes development.</P>

Effects of Ethanol Addition on the Efficiency of Subcritical Water Extraction of Proteins and Amino Acids from Porcine Placenta

Park, Sung Hee,Kim, Jae-Hyeong,Min, Sang-Gi,Jo, Yeon-Ji,Chun, Ji-Yeon Korean Society for Food Science of Animal Resource 2015 한국축산식품학회지 Vol.35 No.2

In a previous study, hydrolysates of porcine placenta were obtained and the extraction efficiency for proteins and amino acids was compared between sub- and super-critical water extraction systems; optimum efficiency was found to be achieved using subcritical water ($170^{\circ}C$, 10 bar). In this study, the effects of adding ethanol to the subcritical water system were investigated. The lowest-molecular-weight extraction product detected weighed 434 Da, and the efficiency of extraction for low-molecular-weight products was increased when either the concentration of ethanol was decreased, or the extraction time was lengthened from 10 min to 30 min. The highest concentration of free amino acids (approximately 8 mM) was observed following 30 min extraction using pure distilled water. The concentration of free amino acids was significantly lower when ethanol was added or a shorter extraction time was used (p<0.05). Color change of the solution following extraction was measured. There were no significant differences in color between lysates produced with different extraction times when using distilled water (p>0.05); however, using different extraction times produced significant differences in color when using 20% or 50% ethanol solution for subcritical extraction (p<0.05). The range of pH for the hydrolysate solutions was 6.4-7.5. In conclusion, the investigated extraction system was successful in the extraction of $\leq$ 500 Da hydrolysates from porcine placenta, but addition of ethanol did not yield higher production of low-molecular-weight hydrolysates than that achieved by DW alone.

변형세포와 비변형세포에서 이온형과 Transferrin 결합형 Fe - 59 와 Ga - 67섭취율의 비교

손명희(Myung Hee Sohn),최기철(Ki Chul Choi),이영환(Young Hwan Lee),이상용(Sang Yong Lee),정경호(Gyung Ho Chung),한영민(Young Min Han),김종수(Jong Soo Kim),임창열(Chang Yeol Yim) 대한핵의학회 1996 핵의학 분자영상 Vol.30 No.1

N/A Pathways both mediated by and independent of transferrin(Tf) and the TfR have been described for the accumulation of iron. Although it is not clear whether the same systems take up iron and gallium, these pathways may suggest the contention that uptake of Ga-67 can, in fact, occur by both Tf-independent and Tf-dependent systems and may share with Fe-59 in part the same mechanism for uptake. The predominant system by which uptake of both radiometals occurs may be different in the degree of the transformation af tumor. Transformed(MMSV/3T3) and untransformed(BALB/3T3) cells were incubated with luM of Ga-67-citrate of Fe-59-chloride for 15 min. at 37℃ in either the presence or absence of Tf. After then, the monolayers were washed with HBSS or PBS, and the cells were solubilized in 1% SDS for gamma well counting and protein determinations. There were similarities, as well as differences, in the pattern of uptake of Fe-59 and Ga-67 presented both in ionic from and as bound to Tf. Both radiometals appeared gain to cells in either ionic or Tf-bound forms. Transformed cells appeared to accumulate more radiometal, either Ga-67 or Fe-59 in the presence of Tf than do the their untransforemd counterparts. Conversly the presentation of either radiometal in ionic form resulted in significantly greater accumulation of metal by the untransformed cells than those transformed. The efficiency for uptake of Ga-67 or Fe-59 in the absence of Tf was greater than for uptake of the Ga-Tf or Fe-Tf. However, the magnitude of difference in efficiency of uptake was greater for Fe-59(10-fold) than for Ga-67 (3-fold). Our results Supports the theory that both Tf-independent and Tf-dependent systems for the uptake of Ga-67 both systems operate oppositely between transformed cells and those untransformed, with uptake by the predominating in transformed cells by the Tf-mediated system and in untransformed cells by the Tf-independent. The uptake of Ga-67 by tumor may share with Fe-59 in part the same mechanism.

금불초 꽃 추출물의 항균 및 항산화 활성

김은희 ( Eun Hee Kim ),김정은 ( Jung Eun Kim ),김규희 ( Kyu Hee Kim ),나의연 ( Eui Yeon Na ),이상기 ( Sang Ki Lee ),정현민 ( Hyun Min Jeong ),이현준 ( Hyun Jun Lee ),박수남 ( Soo Nam Park ) 대한화장품학회 2009 대한화장품학회지 Vol.35 No.3

본 연구에서는 금불초 꽃 추출물의 피부 상재균에 대한 항균작용과 항산화, tyroinase 저해 효과에 관한 조사를 수행하였다. 피부 상재균에 대한 항균활성 측정결과, P. acnes에 대한 ethyl acetate 분획의 MIC는 0.25 %로 나타났으며, methyl paraben과 비슷한 활성을 나타냈고 quercetin보다는 큰 항균활성을 나타내었다. 추출물의 free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) 소거활성(FSC₅₀)은 ethyl acetate 분획에서 8.55 μg/mL로 측정되었다. Luminol-의존성 화학발광법을 이용한 Fe³⁺-EDTA/H₂O₂계에서 생성된 활성산소종(reactive oxygen species, ROS)에 대한 금불초 꽃 추출물의 총 항산화능은 ethyl acetate 분획 0.24 μg/mL로, 50 % EtOH extract와 aglycone 분획 보다 ethyl acetate 분획에서 가장 큰 활성을 나타내었다. 금불초 꽃 추출물에 대하여 rose-bengal로 증감된 사람 적혈구의 광용혈에 대한 억제 효과를 측정하였다. 금불초 꽃 추출물의 경우 5 ~ 100 μg/mL의 농도에서 광용혈을 억제하였다. 특히 당을 제거시킨 플라보노이드 aglycone 분획은 25 μg/mL 농도에서 τ₅₀이 164.15 min으로 매우 큰 세포보호 효과를 나타내었다. 미백 효과측정으로는 각각 tyrosinase의 활성 저해 효과를 측정하였다. Tyrosinase의 활성 저해 효과 (IC₅₀)는 ethyl acetate 분획에서 87.03 μg/mL 로 나타났다. 이상의 결과들은 금불초 꽃 추출물이 ¹O₂ 혹은 다른 ROS를 소광시키거나 소거함으로써 그리고 ROS에 대항하여 세포막을 보호함으로써 생체계, 특히 태양 자외선에 노출된 피부에서 항산화제로서 작용할 수 있음을 가리키며, 금불초 꽃 성분 분석, ethyl acetate 분획의 tyrosinase 저해활성 그리고 피부 상재균에 대한 항균작용으로부터 항산화, 항노화 및 항균성 화장품 소재로서의 응용 가능성을 확인하였다. In this study, the antibacterial activity, antioxidative effects, inhibitory effects on tyrosinase of Inula britannica flower extracts were investigated. MIC values of ethyl acetate fraction from Inula britannica flower on P. acnes 0.25 %, respectively. The results showed that the antibacterial activity of the ethyl acetate fraction was the highest in the P. acnes. The free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activities (FSC₅₀) of ethyl acetate fraction of Inula britannica flower was 8.55 μg/mL. Reactive oxygen species (ROS) scavenging activities (OSC₅₀) of some fInula britannica flower extracts on ROS generated in Fe³⁺- EDTA/H₂O₂ system were investigated using the luminol-dependent chemiluminescence assay. The order of ROS scavenging activities were ethyl acetate fraction 0.24 μg/mL. Ethyl acetate fraction showed the most prominent ROS scavenging activity. The protective effects of extract/fractions of Inula britannica flower on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The Inula britannica flower extracts suppressed photohemolysis in a concentration dependent manner (5 ∼ 100 μg/mL), particularly deglycosylated flavonoid aglycone fraction exhibited the most prominent celluar protective effect (τ₅₀, 164.15 min at 25 μg/mL). The inhibitory effect of Inula britannica flower extracts on tyrosinase was investigated to assess their whitening efficacy. Inhibitory effects (IC₅₀) on tyrosinase of some Inula britannica flower extracts were high. Ethyl acetate fraction has IC₅₀ of 87.03 μg/mL. These results indicate that extract/ fractions of Inula britannica flower can function as antioxidants in biological systems, particularly skin exposed to UV radiation by scavenging ¹O₂ and other ROS, and protect cellular membranes against ROS. And inhibitory activity on tyrosinase of the ethyl acetate fraction and high potential as bactericide against the skin pathogenic bacteria could be applicable to new functional cosmetics for antioxidant, antiaging, antibacterial activity.