1,721,401 research outputs found
Accurate metabolic flux analysis through data reconciliation of isotope balance-based data
No full textVarious techniques and strategies have been developed for the identification of intracellular metabolic conditions, and among them, isotope balance-based flux analysis with gas chromatography/mass spectrometry (GC/MS) has recently become popular. Even though isotope balance-based flux analysis allows a more accurate estimation of intracellular fluxes, its application has been restricted to relatively small metabolic systems because of the limited number of measurable metabolites. In this paper, a strategy for incorporating isotope balance-based flux data obtained for a small network into metabolic flux analysis was examined as a feasible alternative allowing more accurate quantification of intracellular flux distribution in a large metabolic system. To impose GUMS based data into a large metabolic network and obtain optimum flux distribution profile, data reconciliation procedure was applied. As a result, metabolic flux values of 308 intracellular reactions could be estimated from 29 GC/MS based fluxes with higher accuracy.This work was supported by Korean Systems Biology
Research Program (M10309020000-03B5002-00000) of the Ministry of Science and Technology, BK21 project, and
by the KOSEF through the Center for Ultramicrochemical
Process Systems. Further supports by the LG Chem Chair
Professorship, Microsoft and IBM-SUR program are
appreciated
ANALYSIS OF COMBINED CONDUCTIVE AND RADIATIVE HEAT-TRANSFER IN A 2-DIMENSIONAL RECTANGULAR ENCLOSURE USING THE DISCRETE ORDINATES METHOD
No full textAn efficient tool to deal with multidimensional radiative heat transfer is in strong demand to analyse the various thermal problems combined either with other modes of heat transfer or with combustion phenomena. The current study examines the discrete ordinates method (DOM) for coupled radiative and conductive heat transfer in rectangular enclosures in which either a non-scattering or scattering medium is included. The results are compared with the other benchmark approximate solutions. The efficiency and accuracy of the DOM are thus validated.The financial assistance by the Objective Research Fund of the Korea Science and Engineering Foundation is gratefully acknowledged
Thermal development of radiatively active pipe flow with nonaxisymmetric circumferential convective heat loss
No full textThe cooling problem of the hot internal pipe flow has been investigated. Simultaneous conduction, and radiation in the fully developed inner pipe flow were considered with prescribed azimuthally varying convective heat loss at the pipe wall. A complex, nonlinear integro-differential radiative transfer equation was solved by the discrete ordinates method (or called S-N method). The energy equation was solved by control volume based finite difference technique. A parametric study was performed by varying the conduction-to-radiation parameter, optical thickness, and scattering albedo. The results have shown that initially the radiatively active medium could be more efficiently cooled down compared with the cases otherwise. But even for the case with dominant radiation, as the medium temperature was lowered, the contribution of conduction began to exceed radiation. Copyright (C) 1996 Elsevier Science Ltd
An electrical particle velocity profiler for in-channel clogging detection and flow pattern characterization
No full text
In-channel particle position and velocity detectors based on particle transit time across uneven inter-gap electrodes
No full textTRANSIENT COOLING OF A FINITE CYLINDRICAL MEDIUM IN THE RAREFIED COLD ENVIRONMENT
No full textUnsteady cooling problem with conduction and radiation is examined here for a finite cylindrical medium that is exposed to the rarefied cold environment. To solve the energy conservation equation and radiative transfer equation, the finite difference technique with the Crank-Nicolson scheme and the discrete ordinates method were chosen respectively. A parametric study was performed to find the effects of optical diameter, conduction-to-radiation parameter and scattering albedo. Cooling characteristics were discussed through the mean temperature and emittance of the medium. It has been greatly affected by those parameters
Phylogenetic analysis based on genome-scale metabolic pathway reaction content
No full textPhylogenetic classifications based on single genes such as rRNA genes do not provide a complete and accurate picture of evolution because they do not account for evolutionary leaps caused by gene transfer, duplication, deletion and functional replacement. Here, we present a whole-genome-scale phylogeny based on metabolic pathway reaction content. From the genome sequences of 42 microorganisms, we deduced the metabolic pathway reactions and used the relatedness of these contents to construct a phylogenetic tree that represents the similarity of metabolic profiles (relatedness) as well as the extent of metabolic pathway similarity (evolutionary distance). This method accounts for horizontal gene transfer and specific gene loss by comparison of whole metabolic subpathways, and allows evaluation of evolutionary relatedness and changes in metabolic pathways. Thus, a tree based on metabolic pathway content represents both the evolutionary time scale (changes in genetic content) and the evolutionary process (changes in metabolism).This work was financially supported by the
Korean Systems Biology Research Program (M10309020000-
03B5002-00000) of the Korean Ministry of Science and Technology
(MOST). Hardware for computational analysis was supported by the
IBM-SUR program
Systems biotechnology for strain improvement
No full textVarious high-throughput experimental techniques are routinely used for generating large amounts of omics data. In parallel, in silico modelling and simulation approaches are being developed for quantitatively analyzing cellular metabolism at the systems level. Thus informative high-throughput analysis and predictive computational modelling or simulation can be combined to generate new knowledge through iterative modification of an in silico model and experimental design. On the basis of such global cellular information we can design cells that have improved metabolic properties for industrial applications. This article highlights the recent developments in these systems approaches, which we call systems biotechnology, and discusses future prospects.Our work described in this paper was supported by the Korean Systems
Biology Research Program (M10309020000–03B5002–00000) of the
Ministry of Science and Technology and by the BK21 project. Further
support from the LG Chem Chair Professorship, KOSEF and the
IBM-SUR program are greatly appreciated
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