• Journal of Crop Science and Biotechnology
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• 제11권4호
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• pp.249-256
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• 2008

The objective of this work was to evaluate the germination of 12 rice genotypes under propionic acid stress, a phytotoxic compound produced in low drainage soils with high organic matter content. The tests were conducted with the first count of germination (PCG) and germination (G) of the genotypes subjective to 0, 3, 6, and 9 mM propionic acid concentrations. The seeds of each genotype were placed in germitest paper pre-soaked in treatment solutions forming individual bags. The germination was performed at $25^{\circ}C$ and the counts were carried out at 7 (PCG) and 14 days (G). A factorial random block design was performed with four replications of 50 seeds per genotype. Our study revealed that doses up to 9 mM propionic acid in the pre-soaking solution were efficient for genetic variability studies involving the character germination in rice; genetic variability for germination was detected in the collection of rice genotypes when subjected to propionic acid toxic effects. The genotypes Guichow, Dawn, and Toride-1 showed germination stability when subjected to increasing levels of propionic acid, and genotypes originated from irrigated system-cultivation performed better when subjected to propionic acid stress. These three genotypes will be a good biological material to for enhance the resistance to phytotoxic compounds in rice.

• 대한의용생체공학회:의공학회지
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• 제10권2호
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• pp.139-150
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• 1989

새로운 형태의 인공심장용 전동기구동형 혈액동기구동행 혈액 펌프플 개발하였다. 개발된 혈액 펌프는 소형, 고출력, 브러쉬 없는 직류 전동기를 에너지 변환 장치로 사용하였으며, 이 전동기 자체가 원호 형태의 궤적을 따라 좌우로 회전하도록 고안되었으며, 전동기를 포함한 '회전원통'의 웅직임이 좌우에 부착되어 있는 폴리우레탄으로 제작된 혈액 주머니를 번갈아 밀게 되어 혈액을 박출하게 된다. 본 연구에서 도입한 이동형 작동기 원리에 의해 다른 전동기 구동형 혈액 펌프가 안고 있는 두가지의 중요한 문제점인 펌프 크기의 증가와 자연 심장과의 해부학적인 구조상 접합의 문제점들을 개선할 수 있었다. 또한 펌프의 효율과 전동기에 의한 시스템의 온도 상승, 그러고 펌프 내에 유입되는 유체에 대한 이론적 해석을 실시하였으며, 일련의 모의 순환 실험을 통해 실험 결과를 비교하였다. 개발된 펌프 시스템은 이식형 완전 인공 심장으로 사용하기에 충분한 심박출량(9 L/m)과 전부하에 민감한 반응, 그리고 기계적인 안정도를 보여 주었다.

• The Journal of Advanced Prosthodontics
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• 제6권6호
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• pp.456-461
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• 2014

PURPOSE. Translucency and colour stability are two most important aspects for an aesthetic dental restoration. Glass ceramic restorations are popular amongst clinicians because of their superior aesthetic properties. In the last decade, zirconia has generated tremendous interest due to its favorable mechanical and biological properties. However, zirconia lacks the translucency that lithium disilicate materials possess and therefore has limitations in its use, especially in esthetically demanding situations. There has been a great thrust in research towards developing translucent zirconia materials for dental restorations. The objective of the study was to evaluate and compare the transmittance of a translucent variant of zirconia to lithium disilicate. MATERIALS AND METHODS. Two commercially available zirconia materials (conventional and high translucency) and 2 lithium disilicate materials (conventional and high translucency) with standardized dimensions were fabricated. Transmittance values were measured for all samples followed by a microstructural analysis using a finite element scanning electron microscope. One way analysis of variance combined with a Tukey-post hoc test was used to analyze the data obtained (P=.05). RESULTS. High translucency lithium disilicate showed highest transmittance of all materials studied, followed by conventional lithium disilicate, high translucency zirconia and conventional zirconia. The difference between all groups of materials was statistically significant. The transmittance of the different materials correlated to their microstructure analysis. CONCLUSION. Despite manufacturers' efforts to make zirconia significantly more translucent, the transmittance values of these materials still do not match conventional lithium disilicate. More research is required on zirconia towards making the material more translucent for its potential use as esthetic monolithic restoration.

• 폴리머
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• 제35권5호
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• pp.483-487
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• 2011

효율적 비혈관용 약물방출 스텐트 제조를 위해 풀루란 아세테이트(pullulan acetate, PA)가 테프론(poly-tetrafluorethylene; PTFE)으로 피막된 스텐트(PTFE-stent)의 코팅재료로 연구되었다. 파크리탁셀 함유 PA가 코팅된 PTFE-stent의 표면, 약물 방출 거동, 세포독성이 측정되었으며, 동물실험을 통해 이의 가능성이 검토되었다. 전자현미경으로 표면을 관찰한 결과 표면이 PTFE 피막에 비해 훨씬 매끄러웠고, 약물은 80일 동안 서방적 방출 거동을 보였다. PA와 함께 코팅된 파크리탁셀의 안정성을 annexin V 결합 염색법을 통하여 측정한 결과 apoptosis의 비율이 천연 파크리탁셀과 유사한 것으로 보아 봉입된 파크리탁셀의 변성이 없음을 알 수 있었다. 소동물 실험에서는 파크리탁셀이 봉입된 PA-PTFE가 고형암의 성장을 억제하였다. 위의 결과로 보아 PA는 효율적 비혈관계 약물방출 스텐트 개발에 매우 유용한 물질이라고 기대된다.

• 약학회지
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• 제45권1호
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• pp.46-54
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• 2001

Protein carboxyl Ο-methylation is a kind of enzymatic reaction producing carboxyl methylester catalyzed by protein carboxyl Ο-methyltransferases at the carboxyl group of amino acid residues in polypeptide. Since the finding of carboxyl methylesterl many studies have been focused on the under-standing of biological functions in eukaryotes but still not clear except for roles in Ras attachment to membrane and protein repair. In this study, we investigated the protein carboxyl methylation in porcine liver and testis in respect of identification and characterization of carboxyl methylesters and natural proteinous substrates using pH stability of the esters and electrophoresis under acidic and basic conditions. We detected several kinds of methyl esters, 3 kinds each in cytosolic fractions from liver and testis. Under the treatment of strong acid and base, the ratio between base-stable substrates and unstable ones in liver (4 : 6) was different from the ratio obtained in testis (6 : 4). The methyl accepting capacities were affected by enzymatic proteolysis between the range of 55 to 65% in liver and of 35 to 45% in testis. Separation of the methylated proteins by acidic electrophoresis in the presence of urea and SDS revealed distinctively natural substrates of 26, 33 and 80 kD in the cytosol from liver and of 14, 25, 32 and 86 kD from testis. Most of the labelling, however were lost following electrophoresis under moderate alkaline condition, except for molecules of newly detected 7 and 17 kD in livers and 15, 29, 40 and 80 kD in testis. From these results, it was proposed that protein carboxyl Ο-methylation in each organs may be catalyzed by different classes of protein carboxyl Ο-methyltransferases. In addition, it is suggested that the protein carboxyl methylation in liver and testis may have different patterns in respect of natural substrates.

• Journal of Microbiology and Biotechnology
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• 제16권9호
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• pp.1434-1440
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• 2006

The stable anchorage of pyridoxal 5'-phosphate (PLP) in the active site of D-amino acid transaminase (D-AT) is crucial for the enzyme catalysis. The three-dimensional structure of D-AT revealed that Glu32 is one of the active site groups that may playa role in PLP binding. To prove the role of Glu32 in PLP stability, we firstly checked the rate of the potential rate-limiting step. The kinetic analysis showed that the rate of the ${\alpha}$-deprotonation step reduced to 26-folds in E32A mutant enzyme. Spectral analyses of the reaction of D-AT with D-serine revealed that the E32A mutant enzyme failed to stabilize the key enzyme-substrate intermediate, namely a quinonoid intermediate (E-Q). Finally, analysis of circular dichroism (CD) on the wild-type and E32A mutant enzymes showed that the optical activity of PLP in the enzyme active site was lost by the removal of the carboxylic group, proving that Glu32 is indeed involved in the cofactor anchorage. The results suggested that the electrostatic interaction network through the groups from PLP, Glu32, His47, and Arg50, which was observed from the three-dimensional structure of the enzyme, plays a crucial role in the stable anchorage of the cofactor to give necessary torsion to the plane of the cofactor-substrate complex.

• The Journal of Advanced Prosthodontics
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• 제7권2호
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• pp.151-159
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• 2015

PURPOSE. To describe and characterize the surface topography and cleanliness of CAD/CAM manufactured zirconia abutments after steaming and ultrasonic cleaning. MATERIALS AND METHODS. A total of 12 ceramic CAD/CAM implant abutments of various manufacturers were produced and randomly divided into two groups of six samples each (control and test group). Four two-piece hybrid abutments and two one-piece abutments made of zirconium-dioxide were assessed per each group. In the control group, cleaning by steam was performed. The test group underwent an ultrasonic cleaning procedure with acetone, ethyl alcohol and antibacterial solution. Groups were subjected to scanning electron microscope (SEM) analysis and Energy-dispersive X-ray spectroscopy (EDX) to verify and characterize contaminant chemical characterization non- quantitatively. RESULTS. All zirconia CAD/CAM abutments in the present study displayed production-induced wear particles, debris as well as organic and inorganic contaminants. The abutments of the test group showed reduction of surface contamination after undergoing an ultrasonic cleaning procedure. However, an absolute removal of pollutants could not be achieved. CONCLUSION. The presence of debris on the transmucosal surface of CAD/CAM zirconia abutments of various manufacturers was confirmed. Within the limits of the study design, the results suggest that a defined ultrasonic cleaning process can be advantageously employed to reduce such debris, thus, supposedly enhancing soft tissue healing. Although the adverse long-term influence of abutment contamination on the biological stability of peri-implant tissues has been evidenced, a standardized and validated polishing and cleaning protocol still has to be implemented.

• 한국식품과학회지
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• 제11권4호
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• pp.249-257
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• 1979

전보에서 저자들을 물리적 견고성이 우수한 포도당 이성화 효소를 세포 고정화 시킨 제품을 얻었다.(한국 식품 과학 회지, 11(No. 3), 192(1979). 이 효소 제품을 사용하여 실험실 조건에서 회분식 반응조와 충진식 반응조를 운영하여 효소의 반응 특성과 생산성, 활성 감소 현상을 비교 하였다. 본 고정화 효소의 비활성 역가는 회분식 반응조와 충진식 반응조에서 1 g당 각각 48 및 114 units였으며 연속적인 공정에서 더 높은 생산성과 이성화율을 보였다. 효소의 생산성은 체장 시간, 기질의 농도, 효소 부하율(附荷率) 및 반응조의 외형에 영향을 받았으며 충진 밀도가 450 g/l일 때 실제 공간율은 0.36이었으며 비교적 좋은 충진 현상을 보였다. 연속 공정중 효소의 활성 감퇴 현상을 고찰하기 위하여 2.5 M 포도당 용액을 체장 시간이 5.3시간이 되도록 약 220시간 동안 반응시켜 본 결과, 효소 활성 감퇴 곡선은 일차 반응을 따르며 활성 반감기는 115일로 연속 공정에 이용 가능함을 알았다. 이 고정화 효소 제품은 물리적 안정성이 높은 반면 물질 전달 계수가 반응 속도에 큰 영향을 미치는 것으로 나타났다.

• 대한임상검사과학회지
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• 제42권1호
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• pp.22-31
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• 2010

The most common sources of biological trace material which are found in crime scene are the human bloodstains. Reliable identification in the forensic casework is important as it provides crucial insights into crime scene reconstruction and can thus contribute towards solving crimes. Blood-stains are routinely tested in forensic practise using various methods including the leucomalachite green (LMG) test, Kastle-Meyer phenolphthalein test, tetramethylbenzidine test, orthotolidine test, or the luminol chemoluminescence test with the latter cleaning attempts. All these presumptive thus indicative but not identifying tests take advantage of the peroxidase-like activity of the heme unit of the hemoglobin molecule in human blood. Therefore, false-positive results can be caused by the presence of strong oxidants, such as chlorine-containing detergents or by true peroxidases (e.g., from plants). In this study, composition for Gum guaiac was evaluated for the forensic identification of bloodstain and compared with the LMG. The sensitivity and specificity of the composition for Gum guaiac were examined more stable in bloodstain. The positive of Composition for Gum guaiac shown even with the 100,000-fold diluted bloodstain, which was no difference in comparison with LMG test. It was shown that composition for Gum guaiac was very stable to resist boiling for 20 minutes and the effect of bacteria did not affect the genetic analysis as well. The above result of the crime scene investigation, composition for Gum guaiac is easily expected to help identifying bloodstain in the evidences.

• 한국통신학회논문지
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• 제39B권3호
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• pp.143-150
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• 2014

본 논문에서는 컴퓨팅 및 문제 해결 기술로 상당한 주목을 받고 있는 생체 모방 기술을 이용하여 무선 센서망에서 에너지 효율적이고, 요구 지연 시간이 보장된 노드 스케쥴링 제어 방식을 제안한다. 특히 생체의 셀 간 신호 시스템과 무선 센서망 시스템 사이의 유사성을 도출하고, 무선 센서망의 특징을 고려하는 새로운 수학적 모델을 수립한다. 이러한 모델을 바탕으로 각 애플리케이션에 의해서 요구되는 QoS, 지역 환경 조건, 인접 노드들의 상태에 따라 센서 노드의 상태를 결정한다. 제어 이론을 바탕으로 분석을 수행하여 제안된 생체 모방 방식이 각 노드가 자율적으로 매개 변수들을 제어함으로써 시스템 안정성을 보장한다는 것을 보인다. 시뮬레이션 결과를 통해 제안된 방식이 기존 프로토콜과 비교하여 상당한 에너지 절감뿐만 아니라 요구되는 지연 시간을 만족함을 확인한다.