• 제목/요약/키워드: Molecular Structure Characteristics

검색결과 405건 처리시간 0.031초

분자동역학을 이용한 다양한 구조물 위의 수액적의 특성에 대한 연구 (A Study of Characteristics of Water Droplets on Various Nanoscale Structures Using Molecular Dynamics)

  • 이광호;권태우;하만영
    • 설비공학논문집
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    • 제30권1호
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    • pp.33-43
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    • 2018
  • This study numerically investigated statistic and dynamic behaviors of the water droplet on plate with or without various structured-pillars at nano-scale by molecular dynamics simulation. This study considered smooth plate, plate with the rectangular-structured pillar, and the plate with dual-structured pillar under various characteristic energy conditions. The static behavior of water droplet depending on the plate shape, plate surface energy, and the pillar characteristics were examined. After the water droplet reaches its steady state, this study investigated the dynamic behavior of the water droplet by applying a constant force. Finally, this study investigated the static and dynamic behaviors of the water droplet by measuring its contact angle and contact angle hysteresis. As a result, we found that the structure was more hydrophobic.

Morphology and phylogenetic relationships of Micractinium (Chlorellaceae, Trebouxiophyceae) taxa, including three new species from Antarctica

  • Chae, Hyunsik;Lim, Sooyeon;Kim, Han Soon;Choi, Han-Gu;Kim, Ji Hee
    • ALGAE
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    • 제34권4호
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    • pp.267-275
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    • 2019
  • Three new species of the genus Micractinium were collected from five localities on the South Shetland Islands in maritime Antarctica, and their morphological and molecular characteristics were investigated. The vegetative cells are spherical to ellipsoidal and a single chloroplast is parietal with a pyrenoid. Because of their simple morphology, no conspicuous morphological characters of new species were recognized under light microscopy. However, molecular phylogenetic relationships were inferred from the concatenated small subunit rDNA, and internal transcribed spacer (ITS) sequence data indicated that the Antarctic microalgal strains are strongly allied to the well-supported genus Micractinium, including M. pusillum, the type species of the genus, and three other species in the genus. The secondary structure of ITS2 and compensatory base changes were used to identify and describe six Antarctic Micractinium strains. Based on their morphological and molecular characteristics, we characterized three new species of Micractinium: M. simplicissimum sp. nov., M. singularis sp. nov., and M. variabile sp. nov.

The cellular basis of dendrite pathology in neurodegenerative diseases

  • Kweon, Jung Hyun;Kim, Sunhong;Lee, Sung Bae
    • BMB Reports
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    • 제50권1호
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    • pp.5-11
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    • 2017
  • One of the characteristics of the neurons that distinguishes them from other cells is their complex and polarized structure consisting of dendrites, cell body, and axon. The complexity and diversity of dendrites are particularly well recognized, and accumulating evidences suggest that the alterations in the dendrite structure are associated with many neurodegenerative diseases. Given the importance of the proper dendritic structures for neuronal functions, the dendrite pathology appears to have crucial contribution to the pathogenesis of neurodegenerative diseases. Nonetheless, the cellular and molecular basis of dendritic changes in the neurodegenerative diseases remains largely elusive. Previous studies in normal condition have revealed that several cellular components, such as local cytoskeletal structures and organelles located locally in dendrites, play crucial roles in dendrite growth. By reviewing what has been unveiled to date regarding dendrite growth in terms of these local cellular components, we aim to provide an insight to categorize the potential cellular basis that can be applied to the dendrite pathology manifested in many neurodegenerative diseases.

Oligomeric Structures Determine the Biochemical Characteristics of Human Nucleoside Diphosphate Kinases

  • Kim, Sun-Young;Song, Eun-Joo;Chang, Keun-Hye;Kim, Eun-Hee;Chae, Suhn-Kee;Lee, Han-Soo;Lee, Kong-Joo
    • BMB Reports
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    • 제34권4호
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    • pp.355-364
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    • 2001
  • Major human Nucleoside diphosphate kinases (NDPKs) exist as hetero-oligomers, consisting of NDPK-A and NDPK-B, rather than homo-oligomer. To investigate their biological function depending on the oligomeric structure in vivo, we characterized the biochemical properties of cellular NDPK. Cellular NDPKs, which are made up of a unique combination of isoforms, were purified from human erythrocyte and placenta. We found that cellular NDPK and recombinant isoforms NDPKs have their own distinct biochemical properties in autophosphorylation, stability toward heat or urea, and DNA binding. Cellular NDPK was found to have unique characteristics rather than the expected additive properties of recombinant isoforms. The mutations in the dimeric interface of NDPK-B (R34G, N69H or K135L) caused defective DNA binding and simultaneously reduced the enzymatic stability These results suggest that the oligomeric interaction could play a major role in the stability of catalytic domain and might be related to the regulation of various cellular functions of NDPK.

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플라즈마 중합법에 의한 스티렌 박막의 분자 구조 및 분자량 제어에 관한 연구 (A Study on the molecular structure and molecular weight control of styrene films by plasma polymerization)

  • 김종택;최충양;박종관;박응춘;이덕출
    • 한국진공학회지
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    • 제6권3호
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    • pp.213-219
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    • 1997
  • 본 연구에서는 내전극 정전결합 유동가스형 반응장치를 이용하여 플라즈마 중합 스 티렌 박막을 제작하고 적외선분광스펙트럼, 열분해가tm크로마토그래피, 시차주사열량계 및 겔투과성 크로마토그래피의 분석을 통하여 중합조건이 분자구조 및 분자량 분포에 미치는 영향을 조사하였다. 위의 결과로부터 개시 모노머의 화학적 특성과는 다른 고도로 가교된 박막이 생성되었으며, 방전압력, 방전전력 및 가스의 유량 등의 중합조건 조절에 의해 분자 구조, 가교도, 분자량 분포 등의 제어가 가능함이 판명되었다. 따라서 내전극 정전결합 유동 가스형 반응장치에 의해 수행된 플라즈마중합법은 중합조건의 조절에 의해 센서의 감지막, 광도전성 소자 및 포토 레지스트 등에 응용가능한 기능성 유기박막의 제작에 좋은 특성을 나타내는 것을 알 수 있었다.

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Synthesis of dimeric fluorescent TSPO ligand for detection of glioma

  • Tien Tan Bui;Hee-Kwon Kim
    • 대한방사성의약품학회지
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    • 제7권1호
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    • pp.56-65
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    • 2021
  • TSPO, an 18-kDa translocator protein, is a peripheral-type benzodiazepine receptor that has been associated to a variety of biological activities such as apoptosis, steroidogenesis, and cell proliferation. Because TSPO overexpression has been found in various forms of cancer, it has recently become one of the most appealing biological targets for cancer therapies and detection. In order to create new optical imaging agents for improved diagnostics, we synthesized a novel dimeric fluorescent TSPO ligand based on PRB28 structure and SCy5.5. Following the preparation of the novel TSPO ligand, in vivo and ex vivo imaging tests were performed to examine the tumor uptake characteristics of the fluorescent TSPO ligand in a glioma animal model, and it was found that novel TSPO ligand was accumulated in glioma. These results suggested that novel dimeric fluorescent TSPO ligand will be applied to detect glioma.

윤활제의 분자구조가 Base Wax-pigment Composite의 UV-absorption특성에 미치는 영향에 관한 연구 (Influence of Molecular structure of Lubricants on the UV-absorption Characteristics of the Base Wax-pigment Composites)

  • 김승환
    • 한국응용과학기술학회지
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    • 제2권2호
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    • pp.47-53
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    • 1985
  • Correlation among the wax-pigment composites which is base vehicles for the crepas was investigated in terms of fadeness. The base wax synthesized and pigments are compounded with petroleum lubricant and exposed under carbon arc individually. The yellowing phenomenon was appeared on the reference papers coated with the spindle oil which was then exposed. The papers were again extracted with distilled water and pH of them were ranged between 6.2-6.5. Color difference from Adam-Nickerson equation, ${\vartriangle}E$ of base wax is 0.15 and that of spindle oil are varied from 0.66 to 15.62. Since the main components of the petroleum lubricant are aromatic hydrocarbons which have absorptions characteric of UV ranging from 240 to 280 nm, fadeness characteristics of the composites are largely depend upon the change of molecular structure of spindle oil by absorbing UV. Thus the spindle oil having the following physical properties has the better resistance of fadness and is recommended to use in compounding the base wax-pigment composites: ${\cdot}$ main component: paraffinic hydrocarbon ${\cdot}$ pour point: below - $15^{\circ}C$ ${\cdot}$ UV absorption characteristics: ${\lambda}max.$ : 268-290nm ${\cdot}$ absorbancy: below 0.1(0.03ml of sample/50ml of $CHCl_3$)

Molecular Modeling of Small Molecules as BVDV RNA-Dependent RNA Polymerase Allosteric Inhibitors

  • Chai, Han-Ha;Lim, Dajeong;Chai, Hee-Yeoul;Jung, Eunkyoung
    • Bulletin of the Korean Chemical Society
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    • 제34권3호
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    • pp.837-850
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    • 2013
  • Bovine viral diarrhea virus (BVDV), a major pathogen of cattle, is a well-characterized pestivirus which has been used as a good model virus for HCV. The RNA-dependent RNA polymerase (RdRp) plays a key role in the RNA replication process, thus it has been targeted for antivirus drugs. We employed two-dimensional quantitative structure-activity relationship (2D-QSAR) and molecular field analysis (MFA) to identify the molecular substructure requirements, and the particular characteristics resulted in increased inhibitory activity for the known series of compounds to act as effective BVDV inhibitors. The 2D-QSAR study provided the rationale concept for changes in the structure to have more potent analogs focused on the class of arylazoenamines, benzimidazoles, and acridine derivatives with an optimal subset of descriptors, which have significantly contributed to overall anti-BVDV activity. MFA represented the molecular patterns responsible for the actions of antiviral compound at their receptors. We conclude that the polarity and the polarizability of a molecule play a main role in the inhibitory activity of BVDV inhibitors in the QSAR modeling.

근거리 힘 계산의 새로운 고속화 방법 (A New Fast Algorithm for Short Range Force Calculation)

  • 안상환;안철오
    • 유체기계공업학회:학술대회논문집
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    • 유체기계공업학회 2006년 제4회 한국유체공학학술대회 논문집
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    • pp.383-386
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    • 2006
  • In this study, we propose a new fast algorithm for calculating short range forces in molecular dynamics, This algorithm uses a new hierarchical tree data structure which has a high adaptiveness to the particle distribution. It can divide a parent cell into k daughter cells and the tree structure is independent of the coordinate system and particle distribution. We investigated the characteristics and the performance of the tree structure according to k. For parallel computation, we used orthogonal recursive bisection method for domain decomposition to distribute particles to each processor, and the numerical experiments were performed on a 32-node Linux cluster. We compared the performance of the oct-tree and developed new algorithm according to the particle distributions, problem sizes and the number of processors. The comparison was performed sing tree-independent method and the results are independent of computing platform, parallelization, or programming language. It was found that the new algorithm can reduce computing cost for a large problem which has a short search range compared to the computational domain. But there are only small differences in wall-clock time because the proposed algorithm requires much time to construct tree structure than the oct-tree and he performance gain is small compared to the time for single time step calculation.

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