• 한국미생물·생명공학회지
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• 제47권2호
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• pp.278-288
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• 2019

In the present investigation, we attempted to design a protocol to develop a hybrid protein with better bioremediation capacity. Using in silico approaches, a Hybrid Open Reading Frame (Hybrid ORF) is developed targeting the genes of microorganisms known for degradation of organophosphates. Out of 21 genes identified through BLAST search, 8 structurally similar genes (opdA, opd, opaA, pte RO, pdeA, parC, mpd and phnE) involved in biodegradation were screened. Gene conservational analysis categorizes these organophosphates degrading 8 genes into 4 super families i.e., Metallo-dependent hydrolases, Lactamase B, MPP and TM_PBP2 superfamily. Hybrid protein structure was modeled using multi-template homology modeling (3S07_A; 99%, 1P9E_A; 98%, 2ZO9_B; 33%, 2DXL_A; 33%) by $Schr{\ddot{o}}dinger$ software suit version 10.4.018. Structural verification of protein models was done using Ramachandran plot, it was showing 96.0% residue in the favored region, which was verified using RAMPAGE. The phosphotriesterase protein was showing the highest structural similarity with hybrid protein having raw score 984. The 5 binding sites of hybrid protein were identified through binding site prediction. The docking study shows that hybrid protein potentially interacts with 10 different organophosphates. The study results indicate that the hybrid protein designed has the capability of degrading a wide range of organophosphate compounds.

• Steel and Composite Structures
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• 제48권4호
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• pp.443-459
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• 2023

This paper investigates the stability of a bi-directional functionally graded (BD-FG) cylindrical beam made of imperfect concrete, taking into account size-dependency and the effect of geometry on its stability behavior. Both buckling and dynamic behavior are analyzed using the modified coupled stress theory and the classical beam theory. The BD-FG structure is created by using porosity-dependent FG concrete, with changing porosity voids and material distributions along the pipe radius, as well as uniform and nonuniform radius functions that vary along the beam length. Energy principles are used to generate partial differential equations (PDE) for stability analysis, which are then solved numerically. This study sheds light on the complex behavior of BD-FG structures, and the results can be useful for the design of stable cylindrical microstructures.

• 대한화학회지
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• 제44권4호
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• pp.328-336
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• 2000

폴리프로필렌 글리콜의 표면-보조 레이저 탈착/이온화를 이용하여 선형 비행시간 질량 분석기에서 시간-지연 추출법이 분해능 개선, 질량-초점 길이 및 기기 퍼짐 효과의 영향을 수치계산과 비교하여 평가해였다. 비행시간 초점영역은 고저압 펄스의 지연 시간에 비례하였고 지연 시간 변화로 질량 초점 영역을 쉽게 조절할 수있었다. 시간 지연 추출법으로 얻어진 질량 스펙트럼의 분해능은 4500으로 연속추출법(20kV)에 비해 7배 정도 개선되었고 △m=2000의 질량-초점길이를 보여주었다. 시간 지연 추출법에서 기기 퍼짐 요인에 의한 분해능 개선의 한계를 계산하였고 5ns의기기 퍼짐 효과에 의해 동위원소 분리 검출은 분자량 2500까지 가능하였다. 시간 지연 추출법을 이용하여 폴리프로필렌 글리콜 분자가 탄고 표면에서 탈착될 때 생성되는 분열체 시리즈를 개선된 고분해능으로 동위원소 분포 수준으로 확인하였으며 분열 경로 규명 및 동위원소 비 질량분석기로의 응용 가능성을 시험하였다.

• 한국임상약학회지
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• 제3권2호
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• pp.147-155
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• 1993

The cardiac effects of PAF antagonist Ginkgolide B(BN 52051) have been investigated on the isolated perfused guinea pig hearts maintained at the constant hydrostatic perfusion pressure of 80 cm water. PDE(Phosphodiesterase) inhibitor KR-30289 was used as a positive control to see the positive inotropic effects on the perfused hearts. In this expriments, Ginkgolide $B(10^{-5}-SM)$ showed negative inotropic effects by decreasing of LVP, LVDP, LV dp/dt, HR and RPP(Rate Pressure Product). Ginkgolide B also decreased the number of extrasystole by $51.9\%(from\;23.75\pm9.22/min\;to\;11.43\pm435/min)$ induced by global ischemia and reperfusion. The rate, [-dp/dt]/[+dp/dt] increased in preischemia but decreased in postischemia. 1n the separated study the injection of 1ml of Ginkgolide B$(10^{-4M})$ on the isolated heart, increased coronary flow(CF) by $11.8\%(from\;7.5\pm7.65ml/min\;to\;8.5\pm0.29ml/min)$ and decreased the number of extrasystole by $47.6\%(from\;21\pm5.92/min\;to\;11\pm5.27/min)$. In conclusion, Ginkgolide B showed antiarrhythmic and protective effects by decreasing the number of extrasystole and by increasing the coronary flow, respectively.

• Preventive Nutrition and Food Science
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• 제16권2호
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• pp.135-141
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• 2011

Inhibition of intestinal glucose uptake is beneficial in reducing the blood glucose level for diabetes. To search for an effective intestinal glucose uptake inhibitor from natural sources, 70 native edible plants, fruits and vegetables were screened using Caco-2 cells and fluorescent D-glucose analog 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) amino]-2-deoxy-D-glucose (2-NBDG). A compound that was able to inhibit glucose uptake was isolated from methanol extract of Punica granatum L. and called PG-1a. PG-1a appears to be a phthalic acid-diisononyl ester- like compound (PDE) with molecular weight of 418. The inhibitory effect of PG-1a on intestinal glucose uptake was dose-dependent with 89% inhibition at $100\;{\mu}g$/mL. Furthermore, the intestinal glucose uptake inhibitory effect of PG-1a was 1.2-fold higher than phlorizin, a well known glucose uptake inhibitor. This study suggests that PG-1a could play a role in controlling the dietary glucose absorption, and that PG-1a can effectively improve the diabetic condition, and may be used as an optional therapeutic and preventive agent.

• JSTS:Journal of Semiconductor Technology and Science
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• 제3권4호
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• pp.217-222
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• 2003

A new two-dimensional analytical model for the potential distribution and drain-induced barrier lowering (DIBL) effect of fully depleted short-channel Silicon-on-insulator (SOI)-MESFET's has been presented in this paper. The two dimensional potential distribution functions in the active layer of the device is approximated as a simple parabolic function and the two-dimensional Poisson's equation has been solved with suitable boundary conditions to obtain the bottom potential at the Si/oxide layer interface. It is observed that for the SOI-MESFET's, as the gate-length is decreased below a certain limit, the bottom potential is increased and thus the channel barrier between the drain and source is reduced. The similar effect may also be observed by increasing the drain-source voltage if the device is operated in the near threshold or sub-threshold region. This is an electrostatic effect known as the drain-induced barrier lowering (DIBL) in the short-gate SOI-MESFET's. The model has been verified by comparing the results with that of the simulated one obtained by solving the 2-D Poisson's equation numerically by using the pde toolbox of the widely used software MATLAB.

• 대한기계학회논문집B
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• 제21권8호
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• pp.1024-1033
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• 1997

The past several years have witnessed an ever-increasing acceptance and adoption of parallel processing, both for high performance scientific computing as well as for more general purpose applications. Furthermore with increasing needs to perform the complex flow calculations in an efficient manner, the use of the message passing model on distributed networks has emerged as an important alternative to the expensive supercomputers. This work attempts to provide a generic framework to enable the parallelization of all CFD-related works using the master-slave model. This framework consists of (1) input geometry, (2) domain decomposition, (3) grid generation, (4) flow computations, (5) flow visualization, and (6) output display as the sequential components, but performs computations for (2) to (5) in parallel on the workstation clustering. The flow computations are parallized by having multiple copies of the flow-code to solve a PDE on different spatial regions on different processors, while their flow data are exchanged across the region boundaries, and the solution is time-stepped. The Parallel Virtual Machine (PVM) is used for distributed communication in this work.

• BMB Reports
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• 제29권4호
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• pp.372-379
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• 1996

Components I and II (CI&II) are major phosphoproteins in the frog rod outer segments (ROS) of retina, whose phosphorylation is light- and cyclic nucleotide-dependent. Although it was reported that CI & II could be chemically cross-linked to ${\beta}{\gamma}-subunit$ of transducin (${\beta}{\gamma}_t$), it was not clear whether CI&II physically interact with ${\beta}{\gamma}_t$, under native conditions. CI&II extracted by hypotonic washing fo ROS membranes showed an overlapped migration with ${\beta}{\gamma}_t$, in sucrose density gradient centrifugation. The elution profile of CI&II in the peripheral membrane fractions from gel filtration chromatography also overlapped that of ${\beta}{\gamma}_t$. These hydrodynamic parameters indicate that the native molecular state of CI&II in the peripheral membrane fraction appears to be within a complex, most likely with ${\beta}{\gamma}_t$. CI&II coeluted with ${\beta}{\gamma}_t$, showed no phosphorylation by endogenous kinase which phosphorylates a serine of CI&II in other fractions. The purified CI&II were not able to inhibit trypsin-activated cGMP-phosphodiesterase, and CI&II were not recognized by a monoclonal antibody against the ${\gamma}-subunit$ of transducin, indicating that CI&II are not y-subunit of PDE or transducin. Thus, it is likely that native CI&II, which undergo a light-dependent phosphorylation/dephosphorylation cycle, can associate with ${\beta}{\gamma}$, in frog photoreceptor membranes, and the complex formation has an inhibitory effect on the endogenous phosphorylation of CI&II.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제23권4호
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• pp.301-327
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• 2019

The proper orthogonal decomposition (POD) method for time-dependent problems significantly reduces the computational time as it reduces the original problem to the lower dimensional space. Even a higher degree of reduction can be reached if the solution is smooth in space and time. However, if the solution is discontinuous and the discontinuity is parameterized e.g. with time, the POD approximations are not accurate in the reduced space due to the lack of ability to represent the discontinuous solution as a finite linear combination of smooth bases. In this paper, we propose to post-process the sample solutions and re-initialize the POD approximations to deal with discontinuous solutions and provide accurate approximations while the computational time is reduced. For the post-processing, we use the Gegenbauer reconstruction method. Then we regularize the Gegenbauer reconstruction for the construction of POD bases. With the constructed POD bases, we solve the given PDE in the reduced space. For the POD approximation, we re-initialize the POD solution so that the post-processed sample solution is used as the initial condition at each sampling time. As a proof-of-concept, we solve both one-dimensional linear and nonlinear hyperbolic problems. The numerical results show that the proposed method is efficient and accurate.

• 한국추진공학회지
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• 제15권4호
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• pp.57-64
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• 2011

펄스 데토네이션 엔진에서와 같이 탄화수소를 연료로 하는 데토네이션 파는 강한 불안정성을 가지며 난류 연소 효과를 고려한 연구를 수행하여야 함이 제시된 바 있다. 본 연구에서는 강한 불안정성을 가지는 데토네이션 파의 구조를 이해하기 위하여 비점성 해석, 점성 해석, 난류 모델 및 간단한 난류 연소 모델을 고려한 수치 해석 연구를 수행하였다. 모델링 수준에 따른 연구를 통하여 점성 및 난류는 저주파 특성에는 거의 영향이 없으나, 고주파 특성을 강화하는 경향이 있는 것으로 보인다. 한편, 데토네이션 연구를 위한 난류-연소 상호 작용 모델에는 활성화 에너지의 영향이 고려되어야 하는 것으로 여겨진다.