• International Journal of Naval Architecture and Ocean Engineering
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• v.12 no.1
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• pp.501-517
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• 2020

Three-dimensional numerical simulations were performed to study the effects of flow direction and flow velocity on the flow regime behind a curved pipe represented by a curved circular cylinder. The cylinder is based on a previous study and consists of a quarter segment of a ring and a horizontal part at the end of the ring. The cylinder was rotated in the computational domain to examine five incident flow angles of 0-180° with 45° intervals at Reynolds numbers of 100 and 500. The detailed wake topologies represented by λ2 criterion were captured using a Large Eddy Simulation (LES). The curved cylinder leads to different flow regimes along the span, which shows the three-dimensionality of the wake field. At a Reynolds number of 100, the shedding was suppressed after flow angle of 135°, and oblique flow was observed at 90°. At a Reynolds number of 500, vortex dislocation was detected at 90° and 135°. These observations are in good agreement with the three-dimensionality of the wake field that arose due to the curved shape.

• The Korean Journal of Malacology
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• v.29 no.2
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• pp.155-161
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• 2013

Cathepsins are lysosomal/cysteine proteases belong to papain family (C1 family) that is involved in intracellular protein degradation, antigen processing, hormone maturation, and immune responses. In this study, member of cathepsin family was identified from Manila clam (Mc-Cathepsin D) and investigated the immune response against brown ring disease (BRD) causing Vibrio tapetis challenge. The identified Mc-Cathepsin D gene encodes characteristic features typical for the cathepsin family including eukaryotic and viral aspartyl protease signature domain and two highly conserved active sites ($^{84}VVFDTGSSNLWV^{95}$ and $^{270}IADTGTSLLAG^{281}$). Moreover, MC-Cathepsin D shows higher identity values (-50-70%) and conserved amino acids with known cathepsin D members. Transcriptional results (by quantitative real-time RT-PCR) showed that Mc-Cathepsin D was expressed at higher levels in gills and hemocytes than mantle, adductor muscle, foot, and siphon. After the V. tapetis challenge under laboratory conditions, Mc-Cathepsin D mRNA was up-regulated in gills and hemocytes. Present study indicates that Mc-Cathepsin D is constitutively expressed in different tissues and potentially inducible when infecting BRD by V. tapetis. It is further suggesting that Mc-Cathepsin D may be involved in multiple role including immune response reactions against BRD.

• Korean Journal of Optics and Photonics
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• v.17 no.6
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• pp.544-547
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• 2006

A time-domain modeling approach is used to study characteristics of a widely tunable coupled-ring reflector (CRR) laser diode(LD). The CRR consists of a bus waveguide and two coupled ring resonators coupled to the bus without resorting to distributed Bragg grating structure. The tuning range can be a few tens of nanometers with a side mode suppression ratio exceeding 35dB through the adjustment of currents into the phase control sections in the rings. The CRR laser diode has long effective cavity length compared to conventional laser diodes. Accordingly, a broad additional resonance peak in the amplitude modulation characteristics is observed between 20 to 30 GHz, implying the extension of amplitude modulation bandwidth.

• Biomolecules & Therapeutics
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• v.29 no.4
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• pp.392-398
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• 2021

In this study, we determined the effect of 24 different synthetic 4-benzylpiperidine carboxamides on the reuptake of serotonin, norepinephrine, and dopamine (DA), and characterized their structure-activity relationship. The compounds with a two-carbon linker inhibited DA reuptake with much higher potency than those with a three-carbon linker. Among the aromatic ring substituents, biphenyl and diphenyl groups played a critical role in determining the selectivity of the 4-benzylpiperidine carboxamides toward the serotonin transporter (SERT) and dopamine transporter (DAT), respectively. Compounds with a 2-naphthyl ring were found to exhibit a higher degree of inhibition on the norepinephrine transporter (NET) and SERT than those with a 1-naphthyl ring. A docking simulation using a triple reuptake inhibitor 8k and a serotonin/norepinephrine reuptake inhibitor 7j showed that the regions spanning transmembrane domain (TM)1, TM3, and TM6 form the ligand binding pocket. The compound 8k bound tightly to the binding pocket of all three monoamine reuptake transporters; however, 7j showed poor docking with DAT. Co-expression of DAT with the dopamine D₂ receptor (D₂R) significantly inhibited DA-induced endocytosis of D₂R probably by reuptaking DA into the cells. Pretreatment of the cells with 8f, which is one of the compounds with good inhibitory activity on DAT, blocked DAT-induced inhibition of D₂R endocytosis. In summary, this study identified critical structural features contributing to the selectivity of a molecule for each of the monoamine transporters, critical residues on the compounds that bound to the transporters, and the functional role of a DA reuptake inhibitor in regulating D₂R function.

• Analytical Science and Technology
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• v.24 no.2
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• pp.135-141
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• 2011

MMPs (Matrix metalloproteinases) are enzymes playing an important role to turnover and remodel main protein compositions of extracellular matrix. MMP-2 and MMP-9 of MMPs having a catalytic domain which is apart from a hemopexin-like domain part, are different from the other MMPs pertaining fibronectinlike domain close to hemopexin-like domain. It was reported that the development of MMP-9 restrainer can prevent the transfer of liver cancer. In this study, MMP-9 restrainers were extracted and purified from Hovenia dulcis Thunberg. The each fractionary part was examined to investigate the inhibitory effect on MMPs. Three compounds, compound A and B eluted with ethyl acetate (EA) and compound C with methanol, were identified by $^1H$ and $^{13}C$ NMR, GC/MS, and FT-IR. Compound A is considered as a kind of catechine type compound having a benzene ring substituted by hydroxyl and methoxyl groups. Compound B and C are nobiletin type compound pertaining a carbonyl group. Compound A, B and C showed 76%, 66% and 71% of inhibition effect on MMP-9 at 1.0% concentration, respectively. Compound A showed the best inhibition effect on MMP-9.

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2005.09a
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• pp.249-255
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• 2005

Angiotensin-converting enzyme (ACE) is primarily responsible for human hypertension. Current ACE drugs show serious cough and angiodema health problems due to the un-specific activity of the drug to ACE protein. The availability of ACE crystal structure (1UZF) provided the plausible biological orientation of inhibitors to ACE active site (C-domain). Three-dimensional quantitative structure-activity relationship (3D-QSAR) models have been constructed using the comparative molecula. field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) for a series of 28 ACE inhibitors. Alignment for CoMFA obtained by docking ligands to 1UZF protein using FlexX program showed better statistical model as compared to superposition of corresponding atoms. The statistical parameters indicate reasonable models for both CoMFA (q$^2$ = 0.530, r$^2$ = 0.998) and CoMSIA (q$^2$= 0.518, r$^2$ = 0.990). The 3D-QSAR analyses provide valuable information for the design of ACE inhibitors with potent activity towards C-domain of ACE. The group substitutions involving the phenyl ring and carbon chain at the propionyl and sulfonyl moieties of captopril are essential for specific activity to ACE.

• Korea-Australia Rheology Journal
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• v.18 no.4
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• pp.171-181
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• 2006

We present a short review for authors' previous work on direct numerical simulations for inertialess hard particle suspensions formulated either with a Newtonian fluid or with viscoelastic polymeric fluids to understand the microstructural evolution and the bulk material behavior. We employ two well-defined bi-periodic domain concepts such that a single cell problem with a small number of particles may represent a large number of repeated structures: one is the sliding bi-periodic frame for simple shear flow and the other is the extensional bi-periodic frame for planar elongational flow. For implicit treatment of hydrodynamic interaction between particle and fluid, we use the finite-element/fictitious-domain method similar to the distributed Lagrangian multiplier (DLM) method together with the rigid ring description. The bi-periodic boundary conditions can be effectively incorportated as constraint equations and implemented by Lagrangian multipliers. The bulk stress can be evaluated by simple boundary integrals of stresslets on the particle boundary in such formulations. Some 2-D example results are presented to show effects of the solid fraction and the particle configuration on the shear and elongational viscosity along with the micro-structural evolution for both particles and fluid. Effects of the fluid elasticity has been also presented.

• Bulletin of the Korean Chemical Society
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• v.26 no.6
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• pp.952-958
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• 2005

Angiotensin-converting enzyme (ACE) is known to be primarily responsible for hypertension. Threedimensional quantitative structure-activity relationship (3D-QSAR) models have been constructed using the comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) for a series of 28 ACE inhibitors. The availability of ACE crystal structure (1UZF) provided the plausible biological orientation of inhibitors to ACE active site (C-domain). Alignment for CoMFA obtained by docking ligands to 1UZF protein using FlexX program showed better statistical model as compared to superposition of corresponding atoms. The statistical parameters indicate reasonable models for both CoMFA ($q^2$ = 0.530, $r^2$ = 0.998) and CoMSIA ($q^2$ = 0.518, $r^2$ = 0.990). The 3D-QSAR analyses provide valuable information for the design of ACE inhibitors with potent activity towards C-domain of ACE. The group substitutions involving the phenyl ring and carbon chain at the propionyl and sulfonyl moieties of captopril are essential for better activity against ACE.

• Journal of Plant Biotechnology
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• v.35 no.3
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• pp.177-183
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• 2008

Ac/Ds mutant lines of this study were transgenic rice plants, each of which harbored the maize transposable element Ds together with a GUS coding sequence under the control of a promoterless(Ds-GUS). We selected the mutants that were GUS expressed lines, because the GUS positive lines will be useful for identifying gene function in rice. One of these mutants was identified knock-out at Oszinc626(NP_001049991) gene, encoding a RING-H2 zinc-finger protein, by Ds insertion. In this mutant, while primary root development is normal, secondary root development from lateral root was very poor and seed development was incomplete compare with normal plant. RING zinc-finger proteins play important roles in the regulation of development in a variety of organisms. In the plant kingdom, a few genes encoding RING zinc-finger proteins have been documented with visible effects on plant growth and development. The consensus of the RING-H2(C3-H2-C3 type) domain for this group of protein is $Cys-X_2-Cys-X_{28}-Cys-X-His-X_2-His-X_2-Cys-X_{14}-Cys-X_2-Cys$. Oszinc626 encodes a predicted protein product of 445 amino acids residues with a molecular mass of 49 kDa, with a RING-zinc-finger motif located at the extreme end of the C-terminus. RT-PCR analysis indicated that the expression of Oszinc626 gene was induced by IAA, cold, dehydration, high-salinity and abscisic acid, but not by 2,4-D, and the transcription of Oszinc626 gene accumulated primarily in rice immature seeds, root meristem and shoots. The gene accumulation patterns were corresponded with GUS expression.

• Journal of Navigation and Port Research
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• v.31 no.5 s.121
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• pp.415-420
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• 2007

In this paper, we have designed and fabricated a new type of bandpass-filter that used rectangular ring and interdigital capacitive feeding-structure. The filter is applied the modified rectangular ring and interdigital capacitive feeding-structure in patch, which reduce rho size of filter and IEEE 802. 11 correspond to wireless LAN domain(2.45GHz and 5.2GHz) for operating. As a result, the design and fabrication process of the filter become simple and the size of it is reduced more than 60% compared with RF filter are available conventional PEMBF(Parallel Edge-coupled Microstrip Bandpass Filter) of accounted circuit by minimum stage, measurement result of fabricated filter, center frequence is down 2.408GHz and 5.075GHz. input return loss is -39.169dB at 2.408GHz, -40.922dB at 5.075GHz. insertion loss is -0.437dB at 2.408GHz, -1.669dB at 5.075GHz.