• 제목/요약/키워드: Aggregation Characteristics

검색결과 260건 처리시간 0.022초

Oxidative Modification of Neurofilament-L by Copper-catalyzed Reaction

  • Kim, Nam-Hoon;Kang, Jung-Hoon
    • BMB Reports
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    • 제36권5호
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    • pp.488-492
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    • 2003
  • Neurofilament-L (NF-L) is a major element of neuronal cytoskeletons and known to be important for neuronal survival in vivo. Since oxidative stress might play a critical role in the pathogenesis of neurodegenerative diseases, we investigated the role of copper and peroxide in the modification of NF-L. When disassembled NF-L was incubated with copper ion and hydrogen peroxide, then the aggregation of protein was proportional to copper and hydrogen peroxide concentrations. Dityrosine crosslink formation was obtained in copper-mediated NF-L aggregates. The copper-mediated modification of NF-L was significantly inhibited by thiol antioxidants, N-acetylcysteine, glutathione, and thiourea. A thioflavin-T binding assay was performed to determine whether the copper/$H_2O_2$ system-induced in vitro aggregation of NF-L displays amyloid-like characteristics. The aggregate of NF-L displayed thioflavin T reactivity, which was reminiscent of amyloid. This study suggests that copper-mediated NF-L modification might be closely related to oxidative reactions which may play a critical role in neurodegenerative diseases.

연구개발사업 우선순위 설정에 있어서 다속성효용이론(MAUT)과 계층분석과정(AHP)의 비교 (A Comparitive Study of MAUT and AHP in Priority Setting of R&B Projects)

  • 박주형;김정흠
    • 기술혁신학회지
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    • 제2권2호
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    • pp.201-218
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    • 1999
  • The article contains an introduction of possibility of applying Multi-Attribute Utility Theory(MAUT) for priority setting of R&D projects. MAUT is compared with AHP, which is widely used recently. These two techuiques are applied to set priorities of R&D projects In a Government-funded Research Institute. Six criteria are chosen from consultation with decision makers. They are composed of 1) validity as representative projects, 2) possibility of resource mobilization, 3) spillover effect of developed technologies, 4) possibility of success, 5) scope of participation and 6) clarity of research goal. To set priorities of R&D projects, SMART(Simple MultiAttribute Rating Technique) and DVM(Difference Value Measurement) out of many MAUT methods are used to design the utility function and to determine the weights among criteria. The aggregation model is additive on the assumption the criteria are independent. AHP executes pairwise comparisons for criteria and alternatives. From the results of the case study, the results and theoretical characteristics are compared.

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부하동특성 해석을 위한 유도전동기의 최적 축약법 (Optimal Aggregation of Induction Motors for Analysis of Load Dynamics)

  • 이종수;이봉용;정태호;이상중
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1990년도 하계학술대회 논문집
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    • pp.113-120
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    • 1990
  • This paper presents a new aggregation method of induction motors for the load flow and transient stability analysis. The proposed method aggregates a group of motors into a single motor considering the variations of the system voltage and frequency so that the aggregated model represents the dynamic characteristics of the system accurately. The performance of the Method is shown by numerical simulation and is compared with that of LOADSYN algorithm.

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The Dry-aging and Heating Effects on Protein Characteristics of Beef Longissiumus Dorsi

  • Kim, Ji-Han;Lee, Ha-Jung;Shin, Dong-Min;Kim, Tae-Kyung;Kim, Young-Boong;Choi, Yun-Sang
    • 한국축산식품학회지
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    • 제38권5호
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    • pp.1101-1108
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    • 2018
  • The aim of this study was to investigate the effects of dry-aging (DA) and the cooking process on the myofibril protein functionalities and in vitro digestibility of proteins in beef loin. Six sirloins from beef were dry-aged for 28 d, and the control group (n=6) was analyzed 2 d postmortem for this study. Dimensional changes (reduction of thickness and surface shrinkage) after cooking were significantly greater in the control group than the DA group, whereas the shear force of the DA group was significantly lower than that of the control. Effect of cooking on aggregation, hydrophobicity, and in vitro digestibility were significantly higher in the DA group than in the control. After cooking, the protein in DA sirloins was more oxidized than in the control samples. According to the sodium dodecyl sulfate-polyacrylamide gel electrophoresis result, the low molecular weight bands (below 17 kDa) increased in the DA group, finding that the protein characteristics of dry-aged beef was affected by cooking.

Prevalence of Aspirin Resistance and Clinical Characteristics in Patients with Cerebral Infarction

  • Choi, Jong-Tae;Shin, Kyung-A;Kim, Young-Kwon
    • 대한의생명과학회지
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    • 제19권3호
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    • pp.233-238
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    • 2013
  • Aspirin is still the mainstay of antiplatelet therapy in the cardiovascular and cerebrovascular disease. However, some patients are not responsive to the antithrombotic action of aspirin. The aim of this study was to assess the prevalence and clinical characteristics of aspirin resistance in patients with cerebral infarction. We tested platelet function in 557 patients who had been treated with aspirin in J general hospital. Platelet function was tested using the multiple electrode platelet aggregometry (MEA). Platelet reactivity was expressed as area under the aggregation curve (AUC, U) and >30 AUC was defined as aspirin resistance. Aspirin resistance was detected in 16.2% patients. There was not any significant differences in age, gender between aspirin resistance and aspirin sensitive patients. WBC was significantly higher in patients with aspirin resistance (P < .05). HDL-cholesterol was significantly higher in patients with aspirin sensitive (P < .05). Aspirin resistance was positive correlation with platelet count (r =.314, P =.003). The prevalence of aspirin resistance in cerebral infarction was 16.2%, and platelet count were related with aspirin resistance.

제주 바다목장 해역의 인공어초에 유집된 어군 분포의 공간적 특성 (Spatial characteristics of fish distribution lured by artificial reefs in Jeju marine ranching area)

  • 황보규;장호영
    • 수산해양기술연구
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    • 제50권1호
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    • pp.30-38
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    • 2014
  • Hydro-acoustic survey was carried out to investigate the spatial characteristics of fish distribution near two artificial reefs (AO: large octagonal semi-sphere and AC: combined custom built) having different types in Jeju marine ranching area. The survey system consisted of scientific echo sounder (EK60), DGPS system, and ECDIS (Mecys). Field survey was conducted on August and October 2012 with star survey and line transect survey line method, and species composition was investigated from gill net fishing survey. The acoustic signals from individual fishes and small fish schools were mainly recorded around AO, but large and strong signals from large fish school were mainly detected in the top layer of and the water column near AC. The echogram suggest that the fish aggregation for the two types of AO and AC exist the significant difference in fish species and spatial distribution pattern.

분자동역학을 이용한 [C10mim][Br] 의 응집에 관한 연구 (Molecular Dynamics Study of [C10mim][Br] Aggregation)

  • 윤홍민;이준상
    • 대한기계학회논문집B
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    • 제36권8호
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    • pp.873-876
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    • 2012
  • Ionic Liquids (ILs) 는 표준상태에서 액체이온으로 존재하는 물질로 여러 가지 방법으로 다양한 특성을 띄게 할 수 있다. 이런 성질을 적절하게 이용하여 계면활성제 등 다양한 분야로의 응용이 가능하다. ILs의 한 종류인 1-10-alkyl-3-methylimidazolium bromide([C10mim][Br]) 은 특정한 환경에서 양친매성을 가진다. 이번 논문에서 우리는 분자동역학을 이용하여 수용액에서의 [C10mim][Br]의 응집 거동에 대한 연구를 진행하였다. 정준모듬(canonical ensemble)을 이용하여 모사 간 시스템의 부피와 온도를 일정하게 유지시키고 5ns 동안의 전산모사를 통하여 얻은 radial distribution function(RDF)을 이용하여 [C10mim][Br]과 물 분자간의 상호작용 및 그 분포의 특성에 대하여 논의하였다. 분자동역학적 계산을 위하여 LAMMPS 코드를 사용하였고, VMD 코드를 이용하여 후처리(post processing)을 진행하였다.

Physicochemical and Functional Properties of Germinated Glycine max Merr Soybeans

  • Huh, Dam;Bae, Man-Jong;Jo, Deok-Jo;Kim, Jung-Ok;Lee, Kyung-Ae;Lee, Gee-Dong
    • Preventive Nutrition and Food Science
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    • 제12권4호
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    • pp.209-216
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    • 2007
  • To investigate the applicability as the functional food materials of germinated Glycine max Merr soybeans, its biochemical characteristics and its abilities to inhibit platelet aggregation and hydrolyze alcohol were examined. With the progression of germination time, crude protein content gradually increased, and on the 5th day of germination it was 30.19%. However, crude fat content tended to decrease, and on the 5th day of germination it was 14.30%. Total amino acid content was highest on the 3rd day of germination at 80,875 mg%. The free amino acid content doubled from day 0 of germination (1,273.35 mg%) until the 5th day of germination (2,742.99 mg%). Fatty acid analysis revealed that linoleic acid was highest among all the samples, ranging from $53.55{\sim}56.00%$. Linolenic acid content slightly increased as the germination period was prolonged. The ability to inhibit platelet aggregation increased according to the germination period and then decreased again on the 5th day of germination; it was somewhat higher in the ethanol fraction. In measuring ADH, we found that the activity of the ethanol fraction increased with increasing days of germination. In the case of the water fraction, the activity decreased as germination was prolonged, and the ADH activity of the water fraction was higher than that of the ethanol fraction. Based on the above results, we deemed that the Glycine max Merr soybeans germinated for $2{\sim}3$ days were most pertinent for use as functional food materials.

모의류사의 쪽거리 차원 (FRACTAL DIMENSION OF SIMULATED SEDIMENTS)

  • 김형수;윤용남
    • 물과 미래
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    • 제27권3호
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    • pp.115-121
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    • 1994
  • 하구수리계에 있어서 점착성류사의 운동은 응결과 응집(aggregation) 현상에 의해 크게 좌우되며, 이들 현상에 의하여 의결된 입자들의 크기, 모양, 강도는 그 퇴적율과 그리고 부유류사와 오염물질의 변동과정에 영향을 미친다. 본 연구에서는 Brownian 운동에 의해 지배되는 이동성 부유영역과 중력에 의해 지배되는 정체성 부유영역으로 분리하여 점착성입자들의 응집과 응결과정을 모의하였다. 이동성 부유영역에 있어서는 Smoluchowski 모형중 입자들의 무작위 회전을 이용한 최대연쇄 모형으로 응집물질의 사영들을 도출하였으며, 그 회전반경에 의해 사영들의 쪽거리 차원을 구하였다. 저에성 부유영역에서의 응집물질(Brownian 영역을 벗어나 침강하는 응집물질)는 비구형 입자들의 침강으로 간주되어진다. 최종 침강속도 차이로 이들 응집물들은 재차 충돌, 결합하여 보다 큰 응집 입자들을 형성하며, 이들 최종 응집입자들의 사영이 모의되어진다. 최대 Feret's 직경과 Minkowski's sausage logic 개념들을 이용하여 모의되어진 사영들의 둘레 길이에 대하여 쪽거리 차원들을 구하였다.

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전자빔 처리된 다이아몬드의 분광학적 특성 연구 (Study on the Spectroscopic Characteristics of Irradiated Diamonds)

  • 손수학;김배섭;장윤득;김종랑;김종근;김정진
    • 한국광물학회지
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    • 제22권4호
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    • pp.407-415
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    • 2009
  • 전자빔 조사를 조사량에 따라 단계별로 수행하면서 전자빔을 조사하는 동안 다이아몬드 내에서 일어나는 질소관련 결함의 변화와 색상의 변화를 분광학적 방법으로 측정 분석하였다. 일반적으로 질소의 양이 적을수록 공공이 쉽게 생성되며 A집합체보다 B집합체가 많은 시료에서 공공이 빠르게 생성된다는 결과를 보였다. 그 이유로 공공의 생성 정도가 전자빔에 의해 파괴될 수 있는 크기를 가진 결함의 양 즉, platelets에 비례한다는 결론을 추론할 수 있었다. 그리고 조사량이 증가할수록 옅은 녹색을 지닌 청색에서 짙은 청색으로 변화한다. 이러한 청색의 발현은 GR1센터의 점진적인 증가로 GR1센터 흡수포논에 의한 흡수띠의 영역은 더욱 확장되어 가시광선이 투과하는 최고 파장대가 530 nm에서 500 nm로 이동하면서 나타나는 현상이다.