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      • KCI등재

        Inhibition of oxidative stress induced‑cytotoxicity by coptisine in V79‑4 Chinese hamster lung fibroblasts through the induction of Nrf‑2 mediated HO‑1 expression

        Hyeon‑Gyun Jo,Cheol Park,이혜숙,Gi‑Young Kim,Young‑Sam Keum,Jin Won Hyun,Taeg Kyu Kwon,Yung Hyun Choi,Su Hyun Hong 한국유전학회 2021 Genes & Genomics Vol.43 No.1

        Background Coptisine is a natural alkaloid compound and is known to have multiple benefcial efects including antioxidant activity. However, whether it can protect lung fbroblasts from oxidative damage has not been studied yet. Objectives To investigate the potential inhibitory efect of coptisine against oxidative stress in V79-4 lung fbroblast cells. Methods V79-4 cells were treated with H2O2 (1 mM) in the presence or absence of coptisine (50 µg/ml), N-acetyl cysteine (NAC, 10 mM) or zinc protoporphyrin IX (ZnPP, 10 µM) for the indicated times. The alleviating efects of coptisine on cytotoxicity, cell cycle arrest, apoptosis, reactive oxygen species (ROS) production, DNA damage, mitochondrial dynamics, and inhibition of ATP production against H2O2 were investigated. Western blot analysis was used to analyze the expression levels of specifc proteins. Results Coptisine inhibited H2O2-induced cytotoxicity and DNA damage by blocking abnormal ROS generation. H2O2 treatment caused cell cycle arrest at the G2/M phase accompanied by increased expression of cyclin-dependent kinase (Cdk) inhibitor p21WAF1/CIP1 and decreased expression of cyclin B1 and cyclin A. However, these efects were attenuated in the presence of coptisine or NAC. Coptisine also prevented apoptosis by decreasing the rate of Bax/Bcl-2 expression in H2O2-stimulated cells and suppressing the loss of mitochondrial membrane potential and the cytosolic release of cytochrome c. In addition, the activation of nuclear factor-erythroid-2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) was markedly promoted by coptisine in the presence of H2O2. However, zinc protoporphyrin IX, a potent inhibitor of HO-1, attenuated the ROS scavenging and anti-apoptotic efects of coptisine. Conclusions Based on current data, we suggest that coptisine can be used as a potential treatment for oxidative stress-related lung disease.

      • TiN 코팅이 전기도금한 교정용 스테인레스스틸 선재의 세포독성에 미치는 영향

        최준규,조진형,황현식,박병주 전남대학교 치의학연구소 2003 구강과학 Vol.15 No.4

        This study was performed to investigate whether TiN coating could reduce the cytotoxicity of electroplated orthodontic stainless steel wire which had been known to be cytotoxic. Nickel plating was done on stainless steel wire using a electroplating technique. Some of the electroplated wires were coated by TiN film and 4 groups of specimen were prepared (Non-coated electroplated wire, TiN coated electroplated wire, Titanium which was known to have no cytotoxicity, Copper which was known to have high cytotoxicity). Each wire was incubated for 72 hours on the medium. The release of the metal ion was measured by ICP-AES. The incubated medium was diluted 75 %, 50%, 25 % and added on each microplate with Balb/c 3T3 mouse fibroblast for MTT analysis and compared with medium only. Through the measuring of the change in absorbency value of each wire group and the difference of absorbency value according to change of dilution, following results were obtained. 1. The results of ICP-AES analysis showed that lots of nickel ions were isolated from non-coated wires but not isolated from TiN coated wires. 2. The inverted microscope showed that there was a decrease in cell count in non-coated wires but no significant change in TiN coated wires. 3. The results of MTT analysis showed that there was no difference in the absorbency value between TiN coated wires and medium and between titanium and medium but the absorbency value of non-coated wires and copper were lower than that of medium only at all dilution and showed statistically significant differences(p<0.001). 4. Assessment as per ISO 10993, part 5, non-coated wires and copper investigated corresponded to "moderately cytotoxic" and "highly cytotoxic" ; whereas titanium and TiN coated wires were alloted to "non-cytotoxic". The results of the present study indicate that the cytotoxicity of the electroplated orthodontic wire can be changed from "moderately cytotoxic" to "nontoxic" by TiN coating and electroplated wire can be used clinically without the concern of cytotoxicity.

      • 설측브라켓 부착시 위치오차에 관한 연구

        최준규,황현식 전남대학교 치과대학 1996 전남치대논문집 Vol.8 No.1

        The purpose of this study was to evaluate the positioning errors according to the method of bonding lingual brackets. Dental models of twenty orthodontic patients with malocclusion were selected for this study. The positioning errors were measured on each model that brackets were bonded to . Three different bonding methods were used. For the first method, the bracket was bonded intimately to the lingual surface of the model. For the second method, the bracket was bonded intimately to the lingual surface after setting up using articulator. The passive bracketing, bonding the bracket ligated first to ideal archwire, was used after setting up as the last method. The results were as follows : 1. The brackets bonded without setting up showed greater angulation errors in the upper 1st premolar and the lower canine than those in other bonding methods. The brackets bonded without passive bracketing showed greater positioning errors in upper central incisor, lower 1st and 2nd premolars. 2. The brackets bonded without setting up showed greater torque error in lower 2nd premolar than those in other bonding methods. The brackets bonded without passive bracketing showed greater torque errors in all upper teeth, lower 1st and 2nd premolars. 3. The brackets bonded without passive bracketing showed greater rotation errors between upper central incisors, lower central incisors, lower lateral and central incisor, lower canine and lateral incisor. 4. The brackets bonded without setting up showed greater in-out errors between upper canine and lateral incisor than those in other bonding methods. The brackets bonded without passive bracketing showed greater in-out errors between upper central incisors, upper central and lateral incisors, upper 1st and 2nd premolars, lower lateral and central incisors, lower canine and lateral incisor. These results suggest that there is a large amount of positioning error in lingual brackets even by an indirect bonding technique, and it may be reduced by passive bracketing.

      • SCOPUSSCIEKCI등재

        설측브라켓 부착시 위치오차에 관한 연구

        최준규,황현식,김종철 대한치과교정학회 1998 대한치과교정학회지 Vol.28 No.1

        본 연구는 설측브라켓 부착시 부착방법에 따른 위치오차를 알아보기 위하여 시행되었다. 교정환자 20명의 초진시 석고모형을 연구대상으로 하여, 초진모형의 각 치면에 긴밀하게 브라켓을 부착하는 방법, 치아재배열을 시행한 후 치면에 긴밀하게 부착하는 방법 그리고 치아재배열을 시행하고 이상호선을 제작한 후 브라켓을 결찰하여 부착하는 passive bracketing의 3가지 방법으로 브라켓을 부착한 후 각 방법으로 부착된 브라켓의 위치오차를 측정 및 비교하여 다음과 같은 결과를 얻었다. 1. 각도오차 분석결과, 치아재배열을 시행하지 않은 경우 상악 제1소구치와 하악견치의 위치오차가 타 방법에 비하여 크게 나타났으며, passive bracketing을 시행하지 않은 경우 상악 중절치, 하악 제1·제2소구치에서 그 위치오차가 크게 나타났다. 2. 토크오차 분석결과, 치아재배열을 시행하지 않은 경우 하악 제2소구치의 위치오차가 타 방법에 비해 크게 나타났으며 passive bracketing을 시행하지 않은 경우 상악 전 치아와 하악 제1·제2소구치에서 그 위치오차가 크게 나타났다. 3. 회전오차 분석결과, passive bracketing을 시행하지 않은 경우 상악 중절치간, 하악 중절치간, 하악 측절치와 중절치사이 그리고 하악 견치와 측절치 사이에서 그 위치오차가 크게 나타났다. 4. 내외오차 분석결과, passive bracketing을 시행하지 않은 경우 상악 견치와 측절치 사이에서 위치오차가 타 방법에 비해 크게 나타났으며, passive bracketing을 시행하지 않은 경우 상악 중절치간, 측절치와 중절치 사이, 제1·제2소구치사이, 하악 측절치와 중절치 사이, 견치와 측절치 사이에서 그 위치오차가 크게 나타났다. 본 연구 결과는 설측교정술의 경우 브라켓 간접부착 술식을 사용하더라도 상당량의 위치오차가 나타나며, 이는 passive bracketing으로 줄일 수 있음을 시사하였다. The purpose of this study was to evaluate the positioning errors according to the method of bonding lingual brackets. Dental models of twenty orthodontic patients with malocclusion were selected for this study. The positioning errors were measured on each model that brackets were bonded to. Three different bonding methods were used. For the first method, the bracket was bonded intimately to the lingual surface of the model. For the second method, the bracket was bonded intimately to the lingual surface after setting up using articulator. The passive bracketing, bonding the bracket ligated first to ideal archwire, was used after setting up as the last method. The results were as follows: 1. The brackets bonded without setting up showed greater angulation errors in the upper 1st premolar and the lower canine than those in other bonding methods. The brackets bonded without passive bracketing showed greater positioning errors in upper central incisor, lower 1st and 2nd premolars. 2. The brackets bonded without setting up showed greater torque error in lower 2nd premolar than those in other bonding methods. The brackets bonded without passive bracketing showed greater torque errors in all upper teeth, lower 1st and 2nd premolars. 3. The brackets bonded without passive bracketing showed greater rotation errors between upper central incisors, lower central incisors, lower lateral and central incisor, lower canine and lateral incisor. 4. The brackets bonded without setting up showed greater in-out errors between upper canine and lateral incisor than those in other bonding methods. The brackets bonded without passive bracketing showed greater in-out errors between upper central incisors upper central and lateral incisors, upper 1st and 2nd premolars, lower lateral and central incisors, lower canine and lateral incisor. These results suggest that there is a large amount of positioning error in lingual brackets even by an indirect bonding technique, and it may be reduced by passive bracketing.

      • SCIESCOPUSKCI등재
      • KCI등재후보

        브루셀라균에 노출된 미생물 검사실 직원들에 대한 예방적 항생제 요법과 혈청학적 추적검사

        이창섭,이혜수,이재현,박진희,최영실,황규잠,이흥범 대한감염학회 2008 감염과 화학요법 Vol.40 No.2

        The aerozolization is one of possible Brucella transmission mechanisms, particularly in air-borne exposed laboratory workers. In this study, seven laboratory workers were potentially exposed to B. abortus via aerosols. Two laboratory workers who sniffed an agar plate several times were considered to be at high risk for acquiring the disease, 5 workers who did not work directly with the strain were be considered at low risk of infection. Prophylactic antibiotics of doxycycline 200 mg/day and rifampin 600 mg/day were offered for 6 weeks in high risk workers and 3 weeks for low risk workers respectively. Enrolled workers were advised to check for serological testing of Brucella species every 3 weeks during a total period of 12 weeks. Compliance with taking medicine was 57.1% (4/7) and compliance for completing the serological tests was 85.7% (6/7). None of the laboratory workers developed clinical disease or tested positive serologically during 3 months of seroloaical testing and 1 year of clinical follow-up.

      • KCI등재

        Development of a Belt Pick-up Type Two-row Sesame Reaper

        ( Hyeon-jong Jun ),( Il-su Choi ),( Tae-gyoung Kang ),( Young-keun Kim ),( Sang-hee Lee ),( Sung-woo Kim ),( Yong Choi ),( Duck-kyu Choi ),( Choung-keun Lee ) 한국농업기계학회 2016 바이오시스템공학 Vol.41 No.4

        Purpose: The purpose of this study is to develop a walking-type two-row sesame reaper, which can simultaneously perform the cutting and collecting of sesame plants and other crops like perilla and soybean. Methods: The factors involved in reaping sesame were determined experimentally in order to design a prototype of the sesame reaper. The prototype is made up of four parts for cutting, conveying, collecting, and running. The height of two disc-plate saw blades on the cutting part is adjusted by an adjusting wheel, and peripheral speed is adjusted in accordance with the running speed. The conveying belt of the conveying part can be tilted from 0° to 90°. The collecting part extracts a predetermined amount of transferred sesame plants. The prototype was used to evaluate the performance at different working speeds, so that the work efficiency can be calculated. Results: The center of gravity of the sesame plants was 900 mm, measured from the end of the cut stem. The diameter of the disc-plate saw blade was determined to be 355 mm, peripheral speed was 20.4-32.7 m/s, and the picking height of the conveying belt for sesame was 130 mm. The performance of transfer and collection of the sesame, when the insertion angles were 60° and 90°, proved to be excellent. However, when the angle was over 120°, the performance was only 75-80%. The performance was at 100% efficiency when the ratio between running speed and conveying belt speed of the prototype was 1:2, which seems to be the ideal ratio for the sesame reaper. Conclusions: A sesame reaper was developed, which can integrate the processes of cutting, conveying, and collecting, by investigating and considering various factors involved in the reaping process. The sesame reaper can reduce the costs for yielding and producing sesame due to its highly efficient performance.

      • KCI등재

        Study on Performance Improvement of a Head-Feeding Rice Combine for Foxtail Millet Harvesting

        ( Hyeon Jong Jun ),( Il Su Choi ),( Tae Gyoung Kang ),( Yong Choi ),( Duck Kyu Choi ),( Choung Keun Lee ) 한국농업기계학회 2015 바이오시스템공학 Vol.40 No.1

        Purpose: The study was conducted to investigate the proper working conditions like the mesh size of the concave and the chaffer angle of the oscillating sieve, and the fan speed of the head-feeding rice combine for foxtail millet harvesting. Methods: The study aimed to determine the harvesting conditions for the rice combine harvester at a 0.5 m/s working speed and at 40° and 55° sieve chaffer angles. The harvesting loss of the foxtail millet based on the speed of the fan and the oscillating speed of the sieve was measured at three levels of fan speed and oscillating sieve speed. Results: The threshing rates of different foxtail millet varieties were 64.1~83.5% at a mesh size of 7 mm of the concave. In experimental foxtail millet harvesting, the optimal operating condition of the rice combine harvester included a 40° sieve chaffer angle and a 4.8Hz oscillating sieve (cleaning shoe) frequency. The grain loss was found to be lower at a 40° than at a 55° sieve chaffer angle. In field harvesting using the combine harvester, the lowest harvesting grain loss rate of the foxtail millet varieties ranged between 0.2~0.5% at a 7 mm mesh concave, 40° chaffer angle, 4.8 Hz sieve frequency, and a 20 m/s fan speed at an engine speed of 2,000 revolutions per minute (RPM). Conclusions: Findings showed that foxtail millet could be harvested using the combine harvester.

      • KCI등재

        Sorghum Harvesting Using a Head-feeding Type Rice Combine

        ( Hyeon Jong Jun ),( Il Su Choi ),( Tae Gyoung Kang ),( Yong Choi ),( Duck Kyu Choi ),( Choung Keun Lee ),( Sang Hun Kim ) 한국농업기계학회 2018 바이오시스템공학 Vol.43 No.4

        Purpose: The aim of this study was to determine appropriate threshing and selection conditions for sorghum harvesting using a rice combine-harvester. Methods: Sorghum harvesting performance was tested using an actual rice combine. Through this test, the grain loss rate and the composition of crops according to the engine and fan speeds of the combine were investigated. Furthermore, the optimal threshing and selection conditions were determined by carrying out a harvest test based on the opening size factor of the concave in a test field. Results: The grain loss rate for the sorghum using a concave (18×18 mm) of the rice combine was the lowest at 0.1% at a chaffer angle of 40°, engine speed of 2000 rpm, and fan speed of 20 m/s, but the sorting sieve clogged frequently. Furthermore, as the engine speed and fan speed increased, the grain loss rate also increased. The sorghum harvesting test results of the combine according to the concave opening size showed that the grain loss rate was 0.5% at a driving speed of 0.5 m/s, with a concave opening diameter of 13 mm, a chaffer angle of 40°, a concave sieve oscillation frequency of 4.8 Hz, a fan speed of 20 m/s, and an engine speed of 2000 rpm. Conclusions: Findings showed that sorghum could be harvested using a head feeding rice combine.

      • KCI등재

        Design and Safety Performance Evaluation of the Riding Three-Wheeled Two-Row Soybean Reaper

        ( Hyeon-jong Jun ),( Il-su Choi ),( Tae-gyoung Kang ),( Young-keun Kim ),( Sang-hee Lee ),( Sung-woo Kim ),( Yong Choi ),( Duck-kyu Choi ),( Choung-keun Lee ) 한국농업기계학회 2016 바이오시스템공학 Vol.41 No.4

        Purpose: The purpose of this study was to investigate the key factors in designing a three-wheeled two-row soybean reaper (riding type) that is suitable for soybean production, and ensure worker safety by proposing optimal work conditions for the prototype of the designed machine in relation to the slope of the road. Methods: A three-wheeled two-row soybean reaper (riding type) was designed and its prototype was fabricated based on the local soybean-production approach. This approach was considered to be closely related to the prototype-designing of the cutter and the wheel driving system of the reaper. Load distribution on the wheels of the prototype, its minimum turning radius, static lateral overturning angle, tilt angle during driving, and The working and rear overturning (back flip) angle were measured. Based on the gathered information, investigations were conducted regarding optimal work conditions for the prototype. The investigations took into account driving stability and worker safety. Results: The minimum ground clearance of the prototype was 0.5 m. The blade height of the prototype was adjusted such that the cutter was operated in line with the height of the ridges. The load distribution on the prototype`s wheels was found to be 1 (front wheel: F): 1.35 (rear-left wheel: RL): 1.43 (rear-right wheel: RR). With the ratio of load distribution between the RL and RR wheels being 1: 1.05, the left-to-right lateral loads were found to be well-balanced. The minimum turning radius of the prototype was 2.0 m. Such a small turning radius was considered to be beneficial for cutting work on small-scale fields. The sliding of the prototype started at 25°, and its lateral overturning started at 39.3°. Further, the critical slope angle for the worker to drive the prototype in the direction of the contour line on an incline was found to be 12.8°, and the safe angle of slope for the cutting was measured to be less than 6°. The critical angle of slope that allowed for work was found to be 10°, at which point the prototype would overturn backward when given impact forces of 1,060 N on its front wheel. Conclusions: It was determined that farmers using the prototype would be able to work safely in most soybean production areas, provided that they complied with safe working conditions during driving and cutting.

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