• Bulletin of the Korean Chemical Society
• /
• 제31권12호
• /
• pp.3639-3643
• /
• 2010

We have developed CUDA-enabled version of a general purpose molecular dynamics simulation code for GPU. Implementation details including parallelization scheme and performance optimization are described. Here we have focused on the non-bonded force calculation because it is most time consuming part in molecular dynamics simulation. Timing results using CUDA-enabled and CPU versions were obtained and compared for a biomolecular system containing 23558 atoms. CUDA-enabled versions were found to be faster than CPU version. This suggests that GPU could be a useful hardware for molecular dynamics simulation.

• Molecules and Cells
• /
• 제37권9호
• /
• pp.672-684
• /
• 2014

The exact causes of cell death in Parkinson's disease (PD) remain unknown despite extensive studies on PD.The identification of signaling and metabolic pathways involved in PD might provide insight into the molecular mechanisms underlying PD. The neurotoxin 1-methyl-4-phenylpyridinium ($MPP^+$) induces cellular changes characteristic of PD, and $MPP^+$-based models have been extensively used for PD studies. In this study, pathways that were significantly perturbed in $MPP^+$-treated human neuroblastoma SH-EP cells were identified from genome-wide gene expression data for five time points (1.5, 3, 9, 12, and 24 h) after treatment. The mitogen-activated protein kinase (MAPK) signaling pathway and endoplasmic reticulum (ER) protein processing pathway showed significant perturbation at all time points. Perturbation of each of these pathways resulted in the common outcome of upregulation of DNA-damage-inducible transcript 3 (DDIT3). Genes involved in ER protein processing pathway included ubiquitin ligase complex genes and ER-associated degradation (ERAD)-related genes. Additionally, overexpression of DDIT3 might induce oxidative stress via glutathione depletion as a result of overexpression of CHAC1. This study suggests that upregulation of DDIT3 caused by perturbation of the MAPK signaling pathway and ER protein processing pathway might play a key role in $MPP^+$-induced neuronal cell death. Moreover, the toxicity signal of $MPP^+$ resulting from mitochondrial dysfunction through inhibition of complex I of the electron transport chain might feed back to the mitochondria via ER stress. This positive feedback could contribute to amplification of the death signal induced by $MPP^+$.

• Journal of Microbiology and Biotechnology
• /
• 제12권2호
• /
• pp.209-216
• /
• 2002

Bacillus sp. A56 was studied, because of its high flocculating activity. The flocculating substance produced by this strain was purified by ethanol precipitation, cetylpyridinium chloride (CPC) precipitation, and gel permeation chromatography (GPC). The FT-IR spectrum of the purified bioflocculant, designated as BF-56, showed typical characteristics of polysaccharides. The non-sugar substituents, and sugar components of BF-56 containing glucose, fucose, glucuronic acid, and galactose in an approximate molar ratio of 2.76:1.10:1:0.12, suggested that it was a novel bioflocculant with an estimated molecular mass of over $7{\times}10^3$ kDa. Rheological analysis of BF-56 revealed that it was a pseudoplastic that had higher apparent viscosity rate at dilute concentrations than those of zooglan. The solution of bioflocculant BF-56 exhibited non-Newtonian characteristics and it was compatible to high concentrations of salts such as KCl, NaCl, $CaCl_2,\;or\;FeCl_3.$ The present results suggested strong possibility of bioflocculant BF-56 to be fully applicable to industries such as wastewater treatment.

• Journal of Microbiology and Biotechnology
• /
• 제27권5호
• /
• pp.939-942
• /
• 2017

The cellular composition and metabolic compounds of Leuconostoc mesenteroides ATCC 8293 were analyzed after cultivation in an anaerobic chemostat. The macromolecular composition was 24.4% polysaccharide, 29.7% protein, 7.9% lipid, 2.9% DNA, and 7.4% RNA. Its amino acid composition included large amounts of lysine, glutamic acid, alanine, and leucine. Elements were in the order of C > O > N > H > S. The metabolites in chemostat culture were lactic acid (73.34 mM), acetic acid (7.69 mM), and mannitol (9.93 mM). These data provide a first view of the cellular composition of L. mesenteroides for use in metabolic flux analysis.

• 접착 및 계면
• /
• 제25권2호
• /
• pp.43-49
• /
• 2024

최근 유연 유기 시냅스 트랜지스터(flexible organic synaptic transistor, FOST)는 유기 반도체를 채널층으로 하여 유연성, 생체 적합성, 손쉬운 공정성, 복잡성 감소로 인해 주목받고 있다. 또한 기존의 무기 시냅스 소자에 비해 간단한 구조와 낮은 제조 비용으로 인간 뇌의 가소성을 모방할 수 있으므로 차세대 웨어러블 장치 및 소프트 로보틱스 기술에 적용이 가능하다. 유연 유기 시냅스 트랜지스터에서 유기 기판은 소자의 준비 온도에 민감하고 고온 처리 공정은 유기 기판의 열변형을 일으켜 고성능 소자를 제조하기 위해서는 저온용액 기반의 공정 기술이 필요하다. 본 총설에서는 저온 용액 기반 유연 유기 시냅스 트랜지스터 소자의 최신 공정 기술 연구 상황을 요약하고, 이에 따른 문제점과 해결해야 할 과제를 제시하고자 한다.

• 한국축산식품학회지
• /
• 제37권5호
• /
• pp.787-791
• /
• 2017

Panax ginseng marc is produced from fresh ginseng roots during processing and is generally treated as industrial waste. The primary aim of this study was to improve its utilization in the dairy industry as a potential high-value resource. Yogurt was prepared from 11% skim milk powder, 0.1% pectin, 10% sucrose, and ginseng marc ethanol extract (GME, 0.5% and 1.0%) in milk, and was inoculated with a 0.02% yogurt culture (Lactobacillus acidophilus, Bifido-bacterium longum, and Streptococcus thermophilus). After fermentation at $40^{\circ}C$ for 6-8 h, the physicochemical properties of samples were analyzed by the AOAC, Kjeldahl, and Soxhlet methods. Sensory evaluation was performed based on consumer acceptability scores with a 7-point scale, and antimicrobial effects were measured by the agar plate method. The moisture, crude protein, crude fat, and ash contents of yogurt supplemented with 1% GME were $85.06{\pm}0.06%$, $4.41{\pm}0.01%$, $4.30{\pm}0.05%$, and $0.81{\pm}0.03%$, respectively, with no significant changes noted from those of yogurt without GME (control), except for an increase in the crude fat content. The sensory scores of color, flavor, texture, overall taste, and overall acceptance of yogurt supplemented with below 1% GME did not differ significantly (p<0.05) to those of the control yogurt. In addition, the growths of Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes, Escherichia coli, and Enterobacter sakazakii were inhibited during fermentation and storage. These results suggest that GME could be used in dairy products as a supplement and in the food industry as an antimicrobial material.

• 한국패류학회지
• /
• 제26권1호
• /
• pp.1-18
• /
• 2010

자연에 존재하는 생명체들은 유기-무기 성분들이 포함된 미세구조로 이루어진 계층학적으로 복잡한유-무기 나노 복합재를 합성한다. 자연에서 진행되는 유기-무기 나노복합재의 생성 및 재생 과정은 생광물화과정으로서 생물학적 환경에서 진행되는 생광물화과정의 연구는 신물질 합성에 대한 단서를 제공할 뿐만 아니라 산업적으로 중요한공정의 개발에 있어 귀중한 지침으로 활용될 수 있다. 연체동물 역시 생광물화과정을 수행하는 다른 생명체들과 마찬가지로 단백질과 다당류로 이루이진 유기매트릭스와 무기물의 상호작용을 통하여 패각을 설계하고 합성한다. 본 고찰에서는 이매패류의 패각 형성 과정 연구를 기반으로 아울러 생광물화과정 연구를 기반으로 한 소재합성과 관련된 생체모방공학 기술을 고찰하였다.

• Advanced Composite Materials
• /
• 제18권2호
• /
• pp.187-195
• /
• 2009

Much attention has been paid to the processing of inorganic whisker, especially calcium carbonate whisker, which can be used as reinforcement materials of polymer composite due to its low price. Unfortunately, the present synthesis technique of calcium carbonate whisker starts from calcinations of limestone, which involves high energy consumption and furthermore is a highly environment polluting reaction. In this report, needle-like aragonite was synthesized with a reversible solution reaction from limestone without calcination. Optical microscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques were used to characterize the morphology and crystal structure of intermediates as well as that of the product, aragonite. GCC (grinding calcium carbonate) powder was dissolved in an aqueous solution of magnesium sulfate with reflux and air flush. EDTA titration was used to evaluate reaction rate of the dissolution. A kinetics equation of the dissolution reaction was constructed, which displayed second-order kinetics with respect to the concentration of magnesium sulfate. A rate constant of $0.0015\;l^{-3}{\cdot}mol^{-1}{\cdot}h^{-1}$ was obtained. The dissolution reaction gave fiber-like magnesium hydroxide sulfate and gypsum crystal. Then needle-like aragonite with a length of $9.13\;{\pm}\;1.02\;{\mu}m$ and an aspect ratio of $5.64\;{\pm}\;1.37$ was synthesized from the dissolution product with $CO_2$ bubbling at $70^{\circ}C$.

• 폴리머
• /
• 제38권2호
• /
• pp.225-231
• /
• 2014

고분자 결합제로 vinyl acetate(VA) 함량이 각각 30, 60%인 poly(ethylene-co-vinyl acetate)(EVA)를 사용하여 고농축 복합화약 시뮬란트의 유변학적 특성을 연구하였다. 충전제로는 탄산칼슘 및 research department explosive (RDX)와 물리적 특성이 유사한 Dechlorane을 사용하였다. 회분식 용융 혼련기를 사용하여 농축 현탁계를 혼련하였는데 최대 75 v%까지 충전이 가능하였다. 동적 기계적 물성 변화를 측정한 결과 Dechlorane이 탄산칼슘보다 결합제수지와 더 높은 상호작용을 보였다. 일정 전단속도 방식과 일정 전단응력 방식의 평판-평판 레오미터를 사용하여 현탁계의 미세구조의 변화가 유변물성에 미치는 영향을 조사하였고, Krieger-Dougherty 식을 사용하여 최대 충전 부피분율 및 고유점도를 구하였다. EVA31/Dechlorane 현탁계의 최대 충전 부피분율은 약 70 v%이고, 혼련시 전단응력이 약 2000 Pa 정도 부가되는 것이 적절함을 알 수 있었다.

• 한국자원식물학회:학술대회논문집
• /
• 한국자원식물학회 2010년도 정기총회 및 춘계학술발표회
• /
• pp.14-14
• /
• 2010

Plastid proteomics are essential organelles present in virtually all cells in plants and green algae. Plastids are responsible for the synthesis and storage of key molecules required for the basic architecture and functions of plant cells. The proteome of plastid, and in particular of chloroplast, have received significant amounts of attention in recent years. Various fractionation and mass spectrometry (MS) techniques have been applied to catalogue the chloroplast proteome and its sub-organelles compartments. To better understanding the function of the lumenal sub-organelles within the thylakoid network, we have carried out a systematical analysis and identification of the lumenal proteins in the thylakoid of wheat by using Tricine-SDS-PAGE, and LTQ-ESI-FTICR mass spectrometry followed by SWISS-PROT database searching. We isolation and fractionation these membrane from fully developed wheat leaves using a combination of differential and gradient centrifugation couple to high speed ultra-centrifuge. After collecting all proteins to eliminate possible same proteins, we estimated that there are 407 different proteins including chloroplast, chloroplast stroma, lumenal, and thylakoid membrane proteins excluding 20 proteins, which were identified in nucleus, cytoplasm and mitochondria. A combination of these three programs (PSORT, TargetP, TMHMM, and TOPPRED) was found to provide a useful tool for evaluating chloroplast localization, transit peptide, transmembranes, and also could reveal possible alternative processing sites and dual targeting. Finally, we report also sub-cellular location specific protein interaction network using Cytoscape software, which provides further insight into the biochemical pathways of photosynthesis. The present work helps understanding photosynthesis process in wheat at the molecular level and provides a new overview of the biochemical machinery of the thylakoid in wheat.