• Korean Journal of Agricultural Science
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• v.35 no.2
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• pp.147-153
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• 2008

This experiment was conducted to investigate the feed value of Phellinus linteus meal. The chemical composition and particle size of Phellinus linteus meal was determined, and investigated the effect of partial substitution(0, 5, 10 and 20%) of dried Phellinus linteus meal on metabolizability and serum IgG concentration of layers. Crude fiber content of Phellinus linteus meal was higher, and crude protein and crude fat contents were similar level compare to corn, barley, and wheat. Dry matter metabolizability of Phellinus linteus meal was lower in 10 and 20% treatment than those of 0 and 5% treatment significantly(p<0.05). But, Phellinus linteus meal did not affect concentration of serum IgG.

• Bulletin of the Korean Chemical Society
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• v.25 no.9
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• pp.1331-1335
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• 2004

Angiogenesis is essential for the growth and persistence of solid tumors. Their metastases, anti-angiogenesis could lead to the suppression of tumor growth. One of the main strategies of cancer treatment is developing molecules of anti-angiogenic activity. In this study, two angiogenic inhibitors, Ang3 (KLFDF) and Ang4 (XLFDF) derived from KLYDY, which is the sequence of angiostatin active sites kringle 5, were designed and synthesized. Previously we reported the activities and structures of two inhibitors, Ang1 (KLYDY) and Ang2 (KLWDF). In order to investigate the effect of Phe substitution, Ang3 was designed with a sequence of KLFDF. In order to reduce conformational flexibility of side chain in Lys, Ang4 was designed with a sequence of XLFDF, where X has amino substituted phenyl ring. Solution structures of those inhibitors were investigated using NMR spectroscopy and their activities as angiogenesis inhibitors were studied. Ang1 and Ang2 show angiogenic activities, while Ang3 and Ang4 have no activities and have extended structures compared to Ang1 and Ang2. Therefore, Phe rings do not have effective hydrophobic interactions with other aromatic residues in Ang3 and Ang4. The representative structure of Ang2 has a stable intramolecular hydrogen bond. Therefore, intramolecular hydrogen bonding might be more important in stabilizing the structure than the hydrophobic interactions in these inhibitors. More rigid structure, which can be expected to have higher activities and better match with the receptor bound conformations, can be obtained with a constrained cyclic structure. Further peptidomimetic approaches should be tried to develop angiogenesis inhibitors.

• Bulletin of the Korean Chemical Society
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• v.27 no.11
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• pp.1733-1736
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• 2006

A new biologically active peptide with structural similarity to neuromedin N (NMN) has been isolated from extracts of visceral tissue of the African lungfish, Protopterus dolloi, using the rectum of the quail as the bioassay system. The primary structure of NMN-related peptide was established as Lys-Ala-Pro-Tyr-Ile-Leu-OH ([$Ala_2$]-NMN) and contained one substitution ($Ala_2\rightarrow$Ile) compared with the porcine NMN. [$Ala_2$]-NMN was found to have an excitatory effect on rectal muscle tissues of quail (Coturnix japonica), newt (Cynops pyrrhogaster) and black bass (Micropterus sulmoides). The threshold concentration of [Ala2]-NMN for contraction of C. japonica muscle was found to be approximately $10^-11$M. [$Ala_2$]-NMN showed contractile activities in the following order: C. japonica > C. pyrrhogaster > M. sulmoides. The identification of [Ala2]-NMN provides evidence that NMN family, hitherto confined to mammals, has a widespread occurrence in lungfish.

• Journal of the Korean Chemical Society
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• v.37 no.6
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• pp.555-561
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• 1993

Ultraviolet spectrophotometric investigation has been carried out on the system of iododestannylation iodine and tetramethyltin in methanol. The transient CT absorption spectrum can be observed and the subsequent disappearance of CT absorption spectrum was accompained by the cleavage of tetramethyltin with iodine. From there, the rate constants for the iododestannylation were determined at 10, 25 and 35$^{\circ}C$ up to 1600 bar and the reaction rates were increased with increasing temperature and pressure. From these rate constants, the values of the activation parameters (${\Delta}V^\neq,\;{\Delta}{\beta}^{\neq},\;{\Delta}H^{\neq},\;{\Delta}S^{\neq}\;and\;{\Delta}G^{\neq}$) were obtained. The activation volumes and activation compressibility coefficients were both negativity. The activation enthalpies were positive and activation entropies had large negative values. From these values discussed in terms of solvent structure variation of transition state and mechanism. From these results, it was found that the reaction is followed with $S_E2$ mechaenism and weakened $S_E2$ mechanism nature by increasing pressure.

• Polymer(Korea)
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• v.37 no.4
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• pp.533-538
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• 2013

Sodium chloride is present in our body fluids, and the blood contains approximately 0.9 wt% salt, which plays an important role in maintaining the osmotic pressure. However, the amount of salt intake has consistently increased, and an excessive intake can be the cause of high blood pressure, etc. In this study, it was investigated in vivo and in vitro whether biocompatible ionic polymers with K or Ca ions can be replaced by Na ions through an ion exchange process to be excreted. Among the polymers, Ca-polystyrene sulfonate, K-polystyrene sulfonate, Ca-carrageenan, and Ca-tamarind had an excellent Na exchange ability in the body temperature, simulated gastric fluid and also simulated intestinal fluid. The mechanism of Na removal by absorption and excretion without changing food taste in the mouth through the insolubility properties of these polymers is expected to be a solution for the current problems related with excess sodium intake.

• Membrane Journal
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• v.8 no.4
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• pp.210-219
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• 1998

Sulfonated poly(ether sulfone)(SPES) of various ion exchange capacity (IEC) was prepared by heterogeneous sulfonation with chlorosulfonic acid (CSA) to make hydrophilic ultrafiltration membrane for reducing fouling. The effects of CSA concentration, reaction temperature and reaction time has been investigated. The reaction was effective when the temperature is above 10$\circ$C and the CSA concentration is over 0.05 mol, although polymer chain has been significantly degraded. The substitution of sulfonic acid groups was characterized by FTIR and $^1$H-NMR. Transport properties and fouling test have been conducted to the modified SPES ultrafiltration rnembranrs by heterogeneors method. Membranes were obtained using DCM and PVP as a non-solvent and pore forming agent, respectively. Flux reduced and rejection increased with ion exchange capacity. Finger-like structure was disappeared and the thickness of top layer was increased. Dense membrane by non-solvent DCM and porous membrane by pore forming agent PVP was prepared. Fouling was reduced with increasing ion exchange capacity because of hydrophilicity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.4 no.1
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• pp.47-49
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• 2003

The cost of material and slicing of silicon wafer occupied more than 30% of solar cell manufacturing cost. The substitution of silicon wafer into STS 304 stainless steel could be the promising solution to decrease the material cost. Moreover the stainless steel solar cell could have the advantage of low weight and durability. However, the highly polished surface is required to meet the characteristic of solar cell. The electropolishing process in phosphoric acid based solution was used to get the surface quality. The obtained result was 28 nm obtained in current density of 2Amfi/$cm^2$ at $80^{\circ}C$. The leveller effect of glycerine, ethylene glycol and propylen glycol was studied. When the 0.4 g/l of ethylene glycol was added to the electrolyte, the surface roughness was best, 15 nm.

• Journal of Microbiology and Biotechnology
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• v.23 no.1
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• pp.7-14
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• 2013

In the Bacillus amyloliquefaciens ${\alpha}$-amylase (BAA), the loop (residues 176-185; region I) that is the part of the calcium-binding site (CaI, II) has two more amino acid residues than the ${\alpha}$-amylase from Bacillus licheniformis (BLA). Arg176 in this region makes an ionic interaction with Glu126 from region II (residues 118-130), but this interaction is lost in BLA owing to substitution of R176Q and E126V. The goal of the present work was to quantitatively estimate the effect of ionic interaction on the overall stability of the enzyme. To clarify the functional and structural significance of the corresponding salt bridge, Glu126 was deleted (${\Delta}$E126) and converted to Val (E126V), Asp (E126D), and Lys (E126K) by site-directed mutagenesis. Kinetic constants, thermodynamic parameters, and structural changes were examined for the wild-type and mutated forms using UV-visible, atomic absoption, and fluorescence emission spectroscopy. Wild-type exhibited higher $k_{cat}$ and $K_m$ but lower catalytic efficiency than the mutant enzymes. A decreased thermostability and an increased flexibility were also found in all of the mutant enzymes when compared with the wild-type. Additionally, the calcium content of the wild-type was more than ${\Delta}E126$. Thus, it may be suggested that ionic interaction could decrease the mobility of the discussed region, prevent the diffusion of cations, and improve the thermostability of the whole enzyme. Based on these observations, the contribution of loop destabilization may be compensated by the formation of a salt bridge that has been used as an evolutionary mechanism or structural adaptation by the mesophilic enzyme.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.10
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• pp.2030-2038
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• 2009

We analyze the economic effects of mobile termination rate asymmetry by simulation model. The asymmetry allows the mobile operator to get access profits at the expense of the incumbent and induces negative effects such as the entry of inefficient operator and allocative efficiency as well as productive efficiency. We use simulation model to investigate the effect on social welfare of asymmetric regulation. If the brand loyalty is high, social welfare increase as the termination charge of entrant increases. The extension of the basic model shows that the degree of social welfare increase becomes higher as the brand loyalty increases when the cost of entrant is smaller than that of incumbent. But, the degree of social welfare decrease becomes lower as the substitution effects increase.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.295-298
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• 2010

There are three types of survey research system, telephone surveys, online surveys, interviews and so on. Currently most of the survey data have been verified by hand-collecting state in korea. Semi-automated research systems, some companies are using imported from abroad. This paper is the study on the design and implementation of linked research system for global standardization. The system is optimized through customizing for local conditions, as well as professionals for telephone surveys, online surveys, interviews even a normal user can enter the questionnaire easily and quickly. The result data is passed to the customer quickly and accurately. In particular, this system is based on automatic data input and collected provides best efficient analysis and statistics. Office programs and advanced statistical program SPSS is compatible with the maximum benefits for proposed system. Additionally, to achieve the import substitution effect through localization and to propose a global standard the proposed system is designed and implemented.