• Journal of Nutrition and Health
• /
• v.31 no.2
• /
• pp.213-219
• /
• 1998

This study was conducted to compare and evaluate the iodide specific ion electrode method (ISE) and neutron activation analysis method (NAA) for determining iodine in human milk and cow milk. The neutron irradiation and counting operations were carried out at the TRIGA Mark-III reactor facility of the Korea Atomic Energy Research Institute. The mean concentrations of iodine in human milk samples by the ISE and the NAA were 1450$\mu\textrm{g}$/L and 1350$\mu\textrm{g}$/L, respectively. The levels were not significantly different. In cow milk samples , the mean concentrations of iodine by the ISE and the NAA were 250$\mu\textrm{g}$.L and 200$\mu\textrm{g}$/L, respectively. here, the ISE reading was significantly higher than the NAA. reading. The correlations of the two methods were 0.92(p<0.001) for human milk samples and 0.65 for cow milk samples . The coefficient of variation was 8.3% in the ISE and 4.9% in the NAA. Therefore, the iodide specific ion electrode method is sample and fast method, but probably not in processed milk since free sulfhydryl groups in milk are also detected by the iodide electrode. However, these also indicate that the ISE method may be applicable to human milk and pasteurized milk if the conventional pasteurization time-temperature relationship of standards is not exceeded. On the other hand, the NAA method , which is independent of chemical forms and matrix, can be used for determining iodine in all kinds of milk and foods.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.15 no.6
• /
• pp.1355-1362
• /
• 2011

This paper describes a multi-mode LDPC decoder which supports three block lengths(648, 1296, 1944) and four code rates(1/2, 2/3, 3/4, 5/6) of IEEE 802.11n WLAN standard. Our LDPC decoder adopts a block-serial architecture based on min-sum algorithm and layered decoding scheme. A novel way to store check-node values and parity check matrix reduces the sizes of check-node memory and H-ROM. An efficient scheme for check-node memory addressing is used to achieve stall-free read/write operations. The designed LDPC decoder is verified by FPGA implementation, and synthesized with a $0.18-{\mu}m$ CMOS cell library. It has 219,100 gates and 45,036 bits RAM, and the estimated throughput is about 164~212 Mbps at 50 MHz@2.5v.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.16 no.12
• /
• pp.2287-2297
• /
• 1992

The Formulation of a new Hermite straight beam element to eliminate the shear locking is presented. All the kinematic variables in Timoshenko beam are reinterpreted by the consideration of equilibrium equations together. It shows that when the modified transverse displacement field is used the Timoshenko beam looks apparently the same as the Euler beam. The element is formulated for the modified transverse displacement field to have the same interpolation scheme as that in the Hermite element. Transformation Matrix which relates a modified nodal vector with nonmodified one is also introduced to deal with general boundary conditions. Several examples are demonstrated and discussed for the purpose of verification of the concepts employed. The solutions obtained reveal that the element describes of the beam quite correctly, showing no locking and that it is also applicable to the analysis of both thin and thick beams.

• Plant Biotechnology Reports
• /
• v.4 no.3
• /
• pp.201-211
• /
• 2010

We present a highly effective T-DNA inserted gene screening method as part of a reverse genetics model system using the Chinese cabbage (Brassica rapa L. spp. pekinensis). Three-step two-dimensional (2D) matrix strategies are potentially accurate and useful for the identification of specific T-DNA inserted mutants from a large population. To construct our Chinese cabbage model, we utilized a forward genetics screening approach for the abnormal phenotypes that were obtained from transgenic plants of Brassica rapa generated with Agrobacteria tumefaciens containing the pRCV2 vector. From one transgenic plant with an abnormal phenotype, we observed that the st1 gene (which is related to senescence-associated process proteins) contained a T-DNA fragment, and that its expression level was decreased. This T-DNA insert was then used as a control to construct an effective screening pool. As a result, the optimum template concentration was found to be 0.1-1 ng in our PCR strategy. For other conditions, positive changes to the Gibbs free energy prevented the formation of oligo dimers and hairpin loop structures, and autosegment extension gave better results for long fragment amplification. Using this effective reverse genetics screening method, only 23 PCR reactions were necessary to select a target gene from a pool of 100 individual DNAs. Finally, we also confirmed that the sequence we obtained from the above method was identical to the flanking sequence isolated by rescue cloning.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.32 no.3 s.58
• /
• pp.129-134
• /
• 2006

In this study, we examined the effects of antioxidant, lipid peroxidation inhibition and suppression of UVA-induced MMP-1 expression in human dermal fibroblasts. Ligularia fischeri extract showed free radical scavenging effect by 82.3% at 5 mg/mL and superoxide radical scavenging effect by 79.3% at 5 mg/mL in the kanthine/xanthine oxidase system, respectively. At the concentration of $500{\mu}g/mL$, L. fischeri extract showed 97% inhibition on lipid peroxidation of linoleic acid. UVA induced MMP expression in human dermal fibroblasts was reduced 35% by treatment with $100{\mu}g/mL$ of L. fischeri extract. These results suggest that L. fischeri extract can be used for an anti-aging agent by antioxidation, lipid peroxidation inhibition and reducing UVA-induced MMP-1 production.

• Polymer(Korea)
• /
• v.34 no.1
• /
• pp.79-83
• /
• 2010

Alginate beads were prepared using poly(N-isopropylacrylamide-co-dimethylamino ethyl methacrylate)(P(NIPAM-co-DMAEMA)). First, P(NIPAM-co-DMAEMA) was immobilized on the surface of alginate beads by taking advantage of electrostatic interaction between alginate and P(NIPAM-co-DMAEMA). Second, P(NIPAM-co-DMAEMA) was contained in the matrix of alginate beads. P(NIPAM-co-DMAEMA) were prepared by a free radical polymerization at $74^{\circ}C$ for 12 h. The weight ratio of NIPAM to DMAEMA monomer was 95/5. The copolymer was identified by $^1H$-NMR. Releases from the alginate beads were observed at 30, 37, and $45^{\circ}C$ using blue dextran or FITC-dextran(fluorescein isothiocyanate-dextran) as a model drug. The effect of temperature on the degree of release from the beads was insignificant. FITC-dextran was released more than blue dextran possibly due to its smaller molecular weight.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.36 no.3
• /
• pp.270-275
• /
• 2003

Histochemical characteristic and ultrastructure of the mantle of the granular ark, Tegillarca granosa are described using light and electron microscopy. The mantle of the clam is composed of outer epidermis, connective tissue and inner epidermis. The simple epidermis consists of supporting cells, ciliated cells of the two types and secretory cells of three types. Connective tissue is composed of matrix, collagen fibers, muscular fibers and hemolymph sinus. The columnar supporting cell is covered with microvilli on the free surface. Ciliated cells are distributed in the inner epidermis with numerous cilia, microvilli and tubular mitochondria. Secretory cells could be classified into three types (A, B and C) with morphological features of the secretory granules. Type A secretory cells contains secretory granules with fibrous materials of high electron density Type B secretory cells are more abundant than the other cells, and contains secretory granules of membrane-bounded and high electron density. Secretory granules of the type C cells are divided into fibrous core layer and homogeneous peripheral layer. Type B secretory cells are abundant in the both epidermis of marginal mantle, while large number of type A and C secretory cells are evident in the outer epidermis of the central and umbonal mantle. This result showed that the outer and the inner epidermis of the mantle are related with shell formation and cleaning of the mantle cavity, respectively.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2008.10a
• /
• pp.1199-1202
• /
• 2008

High mobility bottom gate thin film transistors (TFTs) with an amorphous gallium tin zinc oxide (a-GSZO) channel layer have been produced by rf magnetron cosputtering using a gallium zinc oxide (GZO) and tin (Sn) targets. The effect of the post annealing temperatures ($200^{\circ}C$, $250^{\circ}C$ and $300^{\circ}C$) was evaluated and compared with two series of TFTs produced at room temperature and $150^{\circ}C$ during the channel deposition. From the results it was observed that the effect of pos annealing is crucial for both series of TFTs either for stability as well as for improving the electrical characteristics. The a-GSZO TFTs operate in the enhancement mode (n-type), present a high saturation mobility of $24.6\;cm^2/Vs$, a subthreshold gate swing voltage of 0.38 V/decade, a turn-on voltage of -0.5 V, a threshold voltage of 4.6 V and an $I_{ON}/I_{OFF}$ ratio of $8{\times}10^7$, satisfying all the requirements to be used in active-matrix backplane.

• Composites Research
• /
• v.15 no.6
• /
• pp.16-23
• /
• 2002

In this work, the effect of anodic oxidation on surface characteristics of high strength PAN-based carbon fibers was investigated in mechanical interfacial properties of composites. The surface properties of the carbon fibers were determined by acid-base values, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and contact angles. And their mechanical interfacial properties of the composites were studied in interlaminar shear strength (ILSS) and critical stress intensity factor ($K_{IC}$). As a result, the acidity or the $O_{ls}/C_{ls}$ ratio of carbon fiber surfaces was increased, due to the development of the oxygen functional groups. Consequently, the anodic oxidation led to an increase in surface free energy of the carbon fibers, mainly due to the increase of its specific (or polar) component. The mechanical interfacial properties of the composites, including ILSS and $K_{IC}$, had been improved in the anodic oxidation on fibers. These results were explained that good wetting played an important role in improving the degree of adhesion at interfaces between fibers and epoxy resin matrix.

• Journal of Gifted/Talented Education
• /
• v.11 no.3
• /
• pp.45-68
• /
• 2001

The Gifted need the constructivist loaming environments that reflect his or her cognitive and affective characteristics and needs to exert their potential fully. 'Structural Communication'was designed to encourage creative thinking in learners, allowing them to create an understanding of a topic, not simply memorize facts. It is considered in line with constructivist philosophy and cognitive paradigms. The major purpose of this study is to explore 'Web-Based Structural Communication'program to embody the collaborative loaming based on constructivism. It was applied on high school $2\times2$ matrix teaming for the gifted students. Recently developed computer technology, emerging network facilities, and internet enable us to extend the usefulness and efficiency of 'Structural Communication’Especially web provides not only the discussion environment that is free from space and time constraints and characteristics of leasers, but also the experiences of knowledge construction through the collaborative learning. Through the 'Web-based Structural Communication', the gifted will be able to argue, persuade and share their unique ideas and gradually elaborated ill-structured ideas. The gifted will escape from the tunnel vision of the early time and have multiple perspectives that are more objective and logical. As the result, the gifted are expected to acquire the effect of 'the Zone of Proximal Development'that Vygotsky advocated.