• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2723-2728
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• 2008

The present study is numerically and experimentally performed to reveal the pumping characteristics of a helical-type molecular drag pump (HTDP) in the molecular transition flow region. In the experimental study, the pressures are measured simultaneously at the 5 positions along the helical channel of rotor under various conditions of outlet pressure and throughputs, and nitrogen is used as test gas. The outlet pressure is in the range of 26-533 Pa. As results, the local pressure changes are checked corresponding to the various outlet pressure and throughput of HTDP. In the numerical study, Navier-Stokes equations with slip boundary conditions are employed (Re< 1000, Kn< 0.1). The local pressure distribution and the pumping speed are calculated. The numerical results are compared with the experimental results. The numerically computed value agrees with the experimental data within an error of approximately 5%.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.126-130
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• 2016

Epidermal growth factor receptor(EGFR)는 HER family에 속하는 tyrosine kinase receptor로서 다양한 하류경로로 신호를 전달하여 세포 증식, 혈관 형성, 세포 사멸을 억제하는 역할을 한다. EGFR이 폐암의 형성에 중요한 역할을 하고 많은 상피세포 종양에서 비정상적으로 활성화됨에 따라 암 치료에 중요한 역할을 하고 있어 EGFR tyrosine kinase inhibitor(TKI)에 관한 많은 연구가 이루어졌다. 위와 같은 약 개발에 있어서 현재 가상 시뮬레이션을 통한 약 후보물질 개발이 진행되고 있다. 특히, Molecular docking 시뮬레이션은 기존의 실험적인 기술(X-ray crystallography, NMR)로는 연구하기가 어려웠던 protein과 ligand간의 상호작용을 예측하여 이에 대한 정보를 제공할 수 있다. 하지만, 우선적으로 Molecular docking 시뮬레이션은 정확한 validation을 기반으로 진행되어야 신뢰할 수 있는 정보를 얻을 수 있다. 따라서 이번 연구에서는 EDISON에서 제공하는 Dock 프로그램과 일반적으로 잘 알려진 Glide, Autodock 프로그램으로 protein data bank(PDB)에서 제공하는 EGFR wild type cocrystal을 redocking하는 방식을 통하여 최상위 rank pose의 RMSD 값을 통한 validation 성능을 비교함으로써 어떤 프로그램이 EGFR과 ligand 간의 결합예측을 하는데 있어서 보다 더 정확한 결과를 낼 수 있는지 알아보고자 하였고 시뮬레이션 결과 Autodock에서 가장 우수한 결과 값을 보여주었다.

• Journal of Chest Surgery
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• v.47 no.3
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• pp.201-210
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• 2014

During the last decade the role of minimally invasive surgery has been increased, especially with the introduction of the robotic system in the surgical field. The most important advantages of robotic system are represented by the wristed instrumentation and the depth perception, which can overcome the limitation of traditional thoracoscopy. However, some data still exist in literature with regard to robotic lobectomy. The majority of papers are focused on its safety and feasibility, but further studies with long follow-ups are necessary in order to assess the oncologic outcomes. We reviewed the literature on robotic lobectomy, with the main aim to better define the role of robotic system in the clinical practice.

• Bulletin of the Korean Chemical Society
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• v.18 no.4
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• pp.415-424
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• 1997

Conformational flexibilities of the GlcNAc(β1,3)Gal(β)OMe are investigated through NMR spectroscopy and molecular modeling. Adiabatic energy map generated with a dielectric constant of 50 contains three local minima. All of the molecular dynamics simulations on three local minimum energy structures show fluctuations between two low energy structures, N2 at φ=80° and ψ=60° and N3 at φ=60° and ψ=-40°. We have presented adequate evidences to state that GlcNAc(β1,3)Gal(β)OMe exists in two conformationally discrete forms. Two state model of N2 and N3 conformers with a population ratio of 40:60 is used to calculate the effective cross relaxation rate and reproduces the experimental NOEs very well. Molecular dynamics simulation in conjunction with two state model proves successfully the dynamic equilibrium existed in GlcNAc(β1,3)Gal(β)OMe and can be considered as a powerful method to analyze the motional properties in the structure of carbohydrate. This observation also cautions against the indiscriminate use of a rigid model to analyze NMR data.

• Bulletin of the Korean Chemical Society
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• v.22 no.6
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• pp.605-610
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• 2001

The molecular geometries and harmonic vibrational frequencies of dibenzofuran in the ground and lowest triplet state have been calculated using the Hartree-Fock and Becke-3-Lee-Yang-Parr(B3LYP)density functional methods with the 6-31G basis set. Upon the excitation to the lowest triplet state, the molecular structure retains the planar form but distorts from a benzene-like to a quinone-like form in skeleton. Scaled vibrational frequencies for the ground and lowest triplet state obtained from the B3LYP calculation show excellent agreement with the available experimental data. A few vibrational fundamentals for both states are newly assigned based on the B3LYP results.

• Archives of Pharmacal Research
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• v.29 no.7
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• pp.582-586
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• 2006

Due to consumer reluctance to take synthetic drugs for nematode infections and the appearance of resistance to anthelminthic drugs, new drugs from natural products must be developed. Caenorhabditis elegans is one of the freely living nematodes and serves as a good model system for screening anthelminthic drugs. In this study, thirteen flavonoid derivatives were tested for anthelminthic activity and the relationships between their activities and structures were investigated. The structural information combined with the data for the larval growth inhibition of C. elegans provided meaningful structural insights in the search for new anthelminthic drugs.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.43.3-43.3
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• 2019

Magnetic fields play an important role in supporting molecular clouds against gravitational collapse. The measured magnetic field strengths in molecular clods enable us to see the effect of magnetic fields in star-forming regions. People have used the Chandrasekhar and Fermi (CF) method to estimate magnetic field strength from observational quantities of molecular cloud density, turbulent velocity and polarization angle dispersion. However, previous studies obtained just one magnetic field strength over the quite large region of a molecular cloud by using the CF method. We here suggest a way to estimate magnetic field strength distribution in Orion A region. We used 450 and 850-micron polarization data of James Clerk Maxwell Telescope (JCMT). Magnetic field strengths were estimated in two wavelengths with 4 pixel resolutions of 16, 20, 24 and 28". Through statistical analysis, we proved the difference of magnetic field strengths between two wavelengths were caused by the difference of their beam sizes. Additionally, we calculated the radii of curvature of polarization segments to select a best pixel resolution for estimating the magnetic field distribution. The pixel resolution should be larger than a radius of curvature. We selected that 20 or 24" pixel resolutions are good choices towards Orion A region.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.68.1-68.1
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• 2019

Using IPHAS $H{\alpha}$ data, we found bright $H{\alpha}$ regions inside the elongated $^{13}CO$ cavity around a Herbig star, MWC 1080. To investigate the ionized hydrogen regions and the molecular cavity, we perform near-IR high-resolution spectroscopic of hydrogen Brackett lines and molecular hydrogen lines by Immersion GRating INfrared Spectrograph (IGRINS) observations. We detected broad Brackett line series and sharp molecular lines with various velocity components. We present three ionized hydrogen regions (near MWC 1080A, MWC 1080E, and CO boundary) with different line widths, central radial velocities, and line ratios. We also show two spatially-separate $Br{\gamma}$ ${\lambda}2.1662{\mu}m$ peaks near MWC 1080A. To reveal a 3D structure of the cavity around MWC 1080, we try to use the detected sharp molecular lines.

• Journal of Species Research
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• v.10 no.2
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• pp.142-153
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• 2021

Algal genomics approaches provide a massive number of genome/transcriptome sequences and reveal the evolutionary history vis-à-vis primary and serial endosymbiosis events that contributed to the biodiversity of photosynthetic eukaryotes in the eukaryote tree of life. In particular, phylogenomic methods using several hundred or thousands of genes have provided new insights into algal taxonomy and systematics. Using this method, many novel insights into algal species diversity and systematics occurred, leading to taxonomic revisions. In addition, horizontal gene transfers (HGTs) of functional genes have been identified in algal genomes that played essential roles in environmental adaptation and genomic diversification. Finally, algal genomics data can be used to address the pangenome, including core genes shared among all isolates and partially shared strain-specific genes. However, some aspects of the pangenome concept (genome variability of intraspecies level) conflict with population genomics concepts, and the issue is closely related to defining species boundaries using genome variability. This review suggests a desirable future direction to merge algal pangenomics and population genomics beyond traditional molecular phylogeny and taxonomy.

• Molecules and Cells
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• v.46 no.2
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• pp.74-85
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• 2023

Single-cell research has provided a breakthrough in biology to understand heterogeneous cell groups, such as tissues and organs, in development and disease. Molecular barcoding and subsequent sequencing technology insert a single-cell barcode into isolated single cells, allowing separation cell by cell. Given that multimodal information from a cell defines precise cellular states, recent technical advances in methods focus on simultaneously extracting multimodal data recorded in different biological materials (DNA, RNA, protein, etc.). This review summarizes recently developed single-cell multiomics approaches regarding genome, epigenome, and protein profiles with the transcriptome. In particular, we focus on how to anchor or tag molecules from a cell, improve throughputs with sample multiplexing, and record lineages, and we further discuss the future developments of the technology.