• Journal of Microbiology and Biotechnology
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• v.12 no.4
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• pp.603-609
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• 2002

DFA IV is di-D-fructose-2,6':6,2'-dianhydride, consisting of two fructose residues. It can be enzymatically synthesized from levan by levan fructotransferase, and can be used for mineral absorption. Understanding of the structure and composition of levan is important to obtain high-level production of DFA IV. A bacterial strain, Pseudomonas aurantiaca 5-4380, was identified to produce low-branched levan, and the levansucrase gene (lsch) from this bacterium was found to be composed of 1,275 Up coding for a protein of 424 amino acids, with an estimated molecular weight of 47 kDa. The bacterial levansucrase gene was expressed in Escherichia coli DH5${\alpha}$ by its own promoter and lac promoter. The recombinant levansucrase was produced in soluble form with 170U of levansucrase activity from 1-ml E. coii culture broth. The expressed enzyme from the clone showed similar biochemical properties, such as size of active levansucrase, degree of branching, and optimum temperature, with P.aurantiaca 5-4380 levansucrase.

• IMMUNE NETWORK
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• v.3 no.2
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• pp.156-163
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• 2003

Background: $\beta$-1,3-glucans are well known to enhance the immune reactions, resulting in antitumor, antibacterial, antiviral, anticoagulatory and wound healing activities. $\beta$-1, 3-glucans have various activities depending on molecular weight, degree of branching, conformation, water-solubility and intermolecular association. However, the $\beta$-1,3-glucan linked backbone structure is essential and $\beta$-D-glucopyranosyl units are required for immuno-potentiating activities. Result: In this study, we tested the immunophamacological activities of soluble $\beta$-1,3-glucans and confirmed the following activities: (1) $IFN-{\gamma}$ production in PBMCs in the presence or the absence of PHA, LPS, or IL-18; (2) induction of various cytokines in the spleen and thymus; (3) adjuvant effect on the antibody production; (4) nitrogen oxide synthesis in macrophages; (5) the cytotoxic and antitumor effects on cell lines and ICR mice. Conclusion: These results strongly suggested that $\beta$-1,3-glucans possessed various immuno-pharmacological activities.

• Korean Journal of Food Science and Technology
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• v.29 no.5
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• pp.876-881
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• 1997

The relationship between the molecular structure of acid-hydrolyzed rice starch and the retrogradation rate of starch gel was investigated. The molecular structure of starch was modified by acid hydrolysis with 1 N HCl at $35^{\circ}C$. The molecular weight of starch decreased as acid hydrolysis time was increased. At the early stage of hydrolysis up to 3 hr, the branching point of amylopectin was degraded and thereafter both ${\alpha}-1,4\;and\;{\alpha}-1,6$ linkages were hydrolyzed. The starch gel (50%) stored at $20^{\circ}C$ revealed that the rapid retrogradation occurred during 4 hr of storage which was more pronounced as the hydrolysis time increased. The degree of retrogradation of starch gels after 4 hr storage showed a linear relationship with the yield of hydrolyzate. These results suggested that the retrogradation of starch gel was accelerated by degradation of ${\alpha}-1,6$ linkages with acid.

• International Journal of Vascular Biomedical Engineering
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• v.2 no.1
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• pp.17-24
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• 2004

Tumor angiogenesis was simulated using a two-dimensional computational model. The equation that governed angiogenesis comprised a tumor angiogenesis factor (TAF) conservation equation in time and space, which was solved numerically using the Galerkin finite element method. The time derivative in the equation was approximated by a forward Euler scheme. A stochastic process model was used to simulate vessel formation and vessel elongation towards a paracrine site, i.e., tumor-secreted basic fibroblast growth factor (bFGF). In this study, we assumed a two-dimensional model that represented a thin (1.0 mm) slice of the tumor. The growth of the tumor over time was modeled according to the dynamic value of bFGF secreted within the tumor. The data used for the model were based on a previously reported model of a brain tumor in which four distinct stages (namely multicellular spherical, first detectable lesion, diagnosis, and death of the virtual patient) were modeled. In our study, computation was not continued beyond the 'diagnosis' time point to avoid the computational complexity of analyzing numerous vascular branches. The numerical solutions revealed that no bFGF remained within the region in which vessels developed, owing to the uptake of bFGF by endothelial cells. Consequently, a sharp, declining gradient of bFGF existed near the surface of the tumor. The vascular architecture developed numerous branches close to the tumor surface (the brush-border effect). Asymmetrical tumor growth was associated with a greater degree of branching at the tumor surface.

• Journal of Microbiology and Biotechnology
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• v.17 no.9
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• pp.1513-1520
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• 2007

[ ${\beta}$ ]-1,3-Glucans enhance immune reactions such as antitumor, antibacterial, antiviral, anticoagulatory, and wound healing activities. ${\beta}$-1,3-Glucans have various functions depending on the molecular weight, degree of branching, conformation, water solubility, and intermolecular association. The molecular weight of the soluble glucan was about 15,000 as determined by a high-performance size exclusion chromatography. From the infrared (IR) and $^{13}C$ NMR analytical data, the purified soluble glucan was found to exclusively consist of ${\beta}$-D-glucopyranose with 1,3 linkage. We tested the immunestimulating activities of the soluble ${\beta}$-1,3-glucan extracted from Agrobacterium sp. R259 KCTC 1019 and confirmed the following activities. IFN-$_{\gamma}$ and each cytokines were induced in the spleens and thymus of mice treated with soluble ${\beta}$-1,3-glucan. Adjuvant effect was observed on antibody production. Nitric oxide was synthesized in monocytic cell lines treated with ${\beta}$-1,3-glucan. The cytotoxic and antitumor effects were observed on various cancer cell lines and ICR mice. These results strongly suggested that this soluble ${\beta}$-1,3-glucan could be a good candidate for an immune-modulating agent.

• Korean Journal of Food Science and Technology
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• v.10 no.1
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• pp.57-62
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• 1978

The morphology and chemical properties of bracken (Pteridium aquilinum) root starch were investigated. The starch granules were mainly sphere and cocoon with the diameter of $5-12\mu$. Polarized micrograph indicated that the starch granule had a hilum at the center of granule, showing a crossed-birefringence. X-ray diffraction pattern demonstrated that the granules showed B-type. The density of the starch was 1.49 and the amylose content was 22%. The ferricyanide number and alkali number were 0.292 and 11.03, respectively. Proximate analysis showed that the starch contained 0.52% lipid, 0.63% ash and 150ppm phosphorus of which over 80% were found in the amylopectin fraction. The iodine affinity and molecular weight of amylose were 16.1 and 83,000 respectively. The degree of branching and glucose units per segment of amylopectin were 3.7% and 27, respectively.

• Journal of Korean Philosophical Society
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• v.142
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• pp.27-50
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• 2017

When we lose our memories or when our self-identity becomes blurred, we may feel as if our mind has split into multiple minds. If someone makes another 'me' by copying my body and mind, how should two conscious 'I's change their credences? In this article, we present a new thought experiment that can be called the 'Two Adams Problem'. This thought experiment represents a piece of philosophical inquiry that speculates on the nature of self-consciousness information that 'I am awake now'. On Sunday evening, as soon as Adam falls asleep, the philosopher Roro makes another Adam by copying Adam's original body and mind. They sleep separately in another room. Within a minute, Roro throws a fair coin. If the coin lands heads up Roro wakes just one of the Adams up on Monday. If the coin lands tails up Roro wakes both Adams up. On Monday, at least one of the Adams will wake up. To what degree ought they believe that the outcome of the coin toss is heads? We will argue that the correct answer to this question is 1/2.

• Korean journal of food and cookery science
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• v.3 no.1
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• pp.31-36
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• 1987

The purpose of this study is to investigate the physicochemcal Properties of the cowpea crude and refined starch and to present the basic data for physicochemical factor which gives the properties of Mook to cowpea starch gel. Water binding capacity of crude starch was 235. In and that of refined starch was 186.0%. The pattern of change in swelling power and solubility for increasing temperature started to increase at $60^{\circ}C$ and increased rapidly from $70^{\circ}C$, for both of crude and refined starch. The optical transmittance of 0.2% crude and refined starch suspensions were increased from $65^{\circ}C$ and showed rapid increasement during 68~$80^{\circ}C$, and their curves showed two-stage processes. The gelatinization pattern for 6n crude and refined starch suspensions were investigated by the Brabender amylograph. The corves showed the pasting temperature of $72.0^{\circ}C$ and $72.1^{\circ}C$, peak height of 11303.U. ($88.0^{\circ}C$) and 970 B.U. ($83.5^{\circ}C$) for crude and refined starch, respectively, and both showed high viscosities when cooling. Blue values for crude and refined starch were 0.369 and 0.376 respectively. Alkali number of crude and refined starch were 7.77 and 7.34, and reducing values were 3.60 and 2. 10, respectively. Amylose content of cowpea starch was 33.7%. Periodate oxidation of the starch fractions resulted that amylose had the average molecular weight of 23590, degree of polymerization of 146 and amylopectin had the degree of branching of 3.42, glucose unit per segment of 29.

• Korean journal of food and cookery science
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• v.3 no.1
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• pp.47-53
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• 1987

The physicochemical properties of kidney bean crude and refined starch were investigated. The results were as follows : Amylose content of refined starch was 77%. Blue values of crude and refined starch were 0.375 and 0.410, respectively. Ferricyanide numbers of crude and refined starch were 1.00 and 1.94, respectively, and alkalinumbers of crude and refined starch were 8.67 and 6.90, respectively. Amylose had molecular weight of 18067 and degree of polymerization was 112. Amylopectin had degree of branching of 3.7 per 100 glucose units and glucose units of 27 per segment of amylopectin. Water binding capacities of crude and refined starch were 202.1% and 169.4%, respectively. Both swelling powers of crude and refined starch were increased rapidly from $70^{\circ}C$ to $90^{\circ}C$ and their curves showed a single-stage pattern. The optical transmittance of 0.2% crude starch suspension was increased rapidly from $80^{\circ}C$ to $83^{\circ}C$ and that of 0.2% refined starch suspension was increased rapidly from $77^{\circ}C$ to $83^{\circ}C$. Brabender hot-paste viscosities of crude and refined starch at 6% and 8% concentation (solid basis) showed the similar amylogram patterns of c type with no peak vircosity.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.4
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• pp.421-428
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• 2007

Eight varieties of milled rice showing different palatabilities were studied in order to identify the relationship between physicochemical properties of carbohydrate components and their fine structure. Gopumbyeo showed the highest palatability value among the eight varieties tested. Both peak viscosity and breakdown were hightest in Hitomebore, and lowest in Mihyangbyeo. No relationship was indicated between the palatability and gelatinization properties. The amylose content of starch showed a significant difference among the varieties tested. However, no relationship was found between the structure of amylose and the palatability of milled rice. The degree of branching(B/A value) was highest in Saechucheongbyeo, and lowest in Palgongbyeo in fine structure of amylopectin. But no relationship was indicated between the B/A values and the palatability of milled rice. Difference was indicated in properties of gelatinization of starch by differential scanning calorimetry. The enthalphy for gelatinization showed a significant difference among the varieties. However, no relationship was found between the enthalphy for gelatinization and the palatability of milled rice. Monosaccharide in endosperm was composed of rice were compound of rhamnose, fucose, ribose, arabinose, and xylose. The total content of monosaccharides was highest in Saechucheongbyeo, and lowest in Palgongbyeo. However, 7 varieties of milled rice, expect Palgongbyeo, showed no relationship between the palatability and monosaccharides contents.