• Polymer(Korea)
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• v.27 no.1
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• pp.17-25
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• 2003

Using atom transfer radical polymerization (ATRP), polystyrene macroinitiators and polystyrene-b-poly(t-butyl acrylate) (PS-b-P(tBA) block copolymers were synthesized by CuBr/PMDETA catalyst system in solution. After hydrolysis, polystyrene-b-poly(acrylic acid), amphiphilic block copolymers, were formed. Subsequent neutralization of polyacid block led to the block ionomers. The molecular weight of the synthesized PS-b-P(tBA) block copolymers was easily-controlled to 5000-10000 and their distributions were less than 1.2. The chemical structures of the synthesized block copolymers were characterized by $^1$H-NMR and FT-IR. In the DSC thermograms, $T_g$ appeared in the vicinity of 100 $^{\circ}C$ because of higher styrene content. In addition, the phase separation of the block ionomers was observed by TEM.

• Journal of Nutrition and Health
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• v.39 no.3
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• pp.264-273
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• 2006

Elevated maternal plasma homocysteine concentrations have been associated with adverse pregnancy outcomes. Serum homocysteine levels may be affected by the MTHFR genotypes and the nutritional status of B vitamins including vitamin $B_2,\;B_6$, folate and vitamin $B_{12}$. We investigated whether postnatal growth measurements were influenced by maternal MTHFR genotypes and their mid-pregnancy serum vitamin B and homocysteine levels. In 130 pregnant women of 24-28 wks of gestation, the MTHFR genotypes, serum B vitamins and homocysteine concentrations were analyzed. Physical growth status was assessed in their offsprings by measuring height, weight, and head and chest circumferences from birth up to 24 months. Serum homocysteine levels were higher in the subjects with T/T genotype than those with the C/T or C/C. Heights and head and chest circumferences of offsprings from the T/T mothers were significantly lower than those from the C/C or C/T mothers only when the serum homocysteine levels were above the median. The mean height of offsprings from the T/T mothers was significantly lower than those from the C/C and C/T mothers. The mean weight and head circumferences of offsprings born from the mothers whose mid-term pregnancy PLP levels were in the lowest quartile was significantly lower than those from mothers in the highest quartile. Heights and head circumferences of offsprings from the T/T mothers were significantly lower than those from the C/C or C/T mothers only when the serum FAD levels were in the lowest quartile. These results suggest that postnatal growth up to 24 months may be influenced by the maternal C677T MTHFR genotypes, and mid-pregnancy serum homocysteine and vitamin B status.

• Journal of the Korean Magnetic Resonance Society
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• v.17 no.1
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• pp.24-29
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• 2013

The structural characteristics of 4-coordinate $BO_4$ [B(1)] and 3-coordinate $BO_3$ [B(2)] groups in $BiB_3O_6$ were studied by $^{11}B$ magic angle spinning (MAS) and single-crystal nuclear magnetic resonance (NMR) spectroscopy. The spin-lattice relaxation time in the laboratory frame, $T_1$, for $^{11}B$ decreased slowly with increasing temperature, whereas the spin-lattice relaxation times in the rotating frame, $T_{1{\rho}}$, for B(1) and B(2), which differed from $T_1$, were nearly constant. Further, $T_{1{\rho}}$ for B(1) and B(2) showed very similar trends, although the $T_{1{\rho}}$ value of B(2) was shorter than that of B(1). The 3-coordinate $BO_3$ and 4-coordinate $BO_4$ were distinguished by $^{11}B$ MAS NMR spectrum and $T_{1{\rho}}$.

• Proceedings of the KSRS Conference
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• 1999.11a
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• pp.491-495
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• 1999

We compared the satellite observed temperature with the radiosonde observed temperature in the Korean Peninsula. The radiosonde observed data were obtained from four upper air observation stations in the Korean Peninsula from 1981 to 1998, and that was compared with the satellite observed data of the channel-2 and channel-4 of microwave sounding unit(MSU) on board NOAA series of polar-orbiting satellites. The radiosonde data were reconstructed into monthly radiosonde T$_{b}$ using MSU weighting function. The monthly climatology shows radiosonde T$_{b2}$ is higher than MSU T$_{b2}$ in summer. The correlation between MSU T$_{b2}$ and radiosonde T$_{b2}$ is 0.72-0.76 and 0.73-0.81 between MSU T$_{b4}$ and radiosonde T$_{b4}$.

• Korean Journal of Pharmacognosy
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• v.35 no.4 s.139
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• pp.330-337
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• 2004

Based on the traditional application of Carthamus tinctorious L. (CF) as a component of Korean medicinal decoctions, in the present study, we investigated in vitro an immunomodulatory activity of water extract of CF(WECF). Water extract of CF significantly increased the in vitro proliferative responses of spleen cells (SPC). However, addition of WECF during anti-CD3 activation resulted in a significant decrease in SPC proliferation. Flow cytometric analysis showed that WECF addition chanced T and B cell frequencies in anti-CD3-activated spleen cell populations. Using purified cells, it was revealed that WECF is mitogenic to B cells but rather inhibitory to T cell Proliferation. Upon anti-CD3 stimulation, high concentration (1 mg/ml) of WECF significantly inhibited T cell proliferation until day 2 of stimulation. At day 3, anti-CD3-activated cells exposed to WECF recovered their proliferation to the level comparable to control. Although B cell proliferation was also inhibited in proliferation at day 1, it recovered sooner and then was rather augmented by WECF at day 3. These data indicate that WECF down-regulates lymphocyte proliferation at early phase of activation but T cells are more vulnerable than B cells to WECF, However, CD4+ and CD8+ T cells did not differ in WECF-mediated immunotoxicity. Data of propidium iodide (PI) staining showed that WECF accelerates activated T cell, but not B cell, apoptosis and WECF concurrently inhibited cytokine production of activated T cells. Taken together, WECF exhibits B cell mitogenic activity and differential toxicity more pronounced to T cells, suggesting a possible in vivo application of WECF for specific control of T cells without alteration of B cell activity.

• IMMUNE NETWORK
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• v.14 no.4
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• pp.207-218
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• 2014

Chronic virus infection leads to the functional impairment of dendritic cells (DCs) as well as T cells, limiting the clinical usefulness of DC-based therapeutic vaccine against chronic virus infection. Meanwhile, B cells have been known to maintain the ability to differentiate plasma cells producing antibodies even during chronic virus infection. Previously, ${\alpha}$-galactosylceramide (${\alpha}GC$) and cognate peptide-loaded B cells were comparable to DCs in priming peptide-specific $CD8^+$ T cells as antigen presenting cells (APCs). Here, we investigated whether B cells activated by ${\alpha}GC$ can improve virus-specific T cell immune responses instead of DCs during chronic virus infection. We found that comparable to B cells isolated from naïve mice, chronic B cells isolated from chronically infected mice with lymphocytic choriomeningitis virus (LCMV) clone 13 (CL13) after ${\alpha}GC$-loading could activate CD1d-restricted invariant natural killer T (iNKT) cells to produce effector cytokines and upregulate co-stimulatory molecules in both naïve and chronically infected mice. Similar to naïve B cells, chronic B cells efficiently primed LCMV glycoprotein (GP) 33-41-specific P14 $CD8^+$ T cells in vivo, thereby allowing the proliferation of functional $CD8^+$ T cells. Importantly, when ${\alpha}GC$ and cognate epitope-loaded chronic B cells were transferred into chronically infected mice, the mice showed a significant increase in the population of epitope-specific $CD8^+$ T cells and the accelerated control of viremia. Therefore, our studies demonstrate that reciprocal activation between ${\alpha}GC$-loaded chronic B cells and iNKT cells can strengthen virus-specific T cell immune responses, providing an effective regimen of autologous B cell-based therapeutic vaccine to treat chronic virus infection.

• Journal of the Korean Wood Science and Technology
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• v.18 no.1
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• pp.39-51
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• 1990

This research was carried out to offer the basis data for development of optimum drying schedule for a domestic oak species (Quercus grosseserrata B1.) by investigating drying rate. stress, defect, and moisuture gradient with board thicknesses and drying schedules (code number T4-C2 and T3-B1). The results were obtained as follows: 1. Average drying rate and total drying time from 52.2% to 5.8% were 0.105%/hr and 486 hours for drying schedule T4-C2 and those from 62.1% to 8.3% were 0.070%/hr. and 811 hours for drying schedule T3-B1. 2. Drying rates for 28mm- and 31mm-thick boards showed similar tendency, but were significantly different from 25mm- thick board in drying schedule T4-C2 and those for 22mm-, 25mm- 28mm- and 31mm-thick boards showed similar tendency but were significantly different from 19mm- thick boards in drying schedule T3-B1. 3. The moisture gradients for drying schedule T4-C2 were steeper than those for drying schedule T3-B1 during drying period. and especially in early drying stage slow slope of moisture gradients of drying schedule T3-B1 was effective in preventing serious problem of surface checks. 4. Drying stresses were lower in drying schedule T3-B1 than in drying schedule T4-C2 during drying period. 5. Drying schedule T4-C2 was appropriate for 25mm-thick board but not for 28mm- and 31mm-thick board because of strong drying condition. Drying schedule T3-B1 was appropriate for 28mm- and 31 mm-thick board but not for 19mm-, 22mm-, and 25mm-thick board because of weak drying condition.

• Journal of Sericultural and Entomological Science
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• v.35 no.2
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• pp.120-128
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• 1993

The objective of this study is to identify plasmids of Bacillus thuringiensis var. kurstaki HD-1(B. t k HD-1) toxic to lepidopteran larvae. The results from agarose gel electrophoresis indicated that the bacterium contained 9 plasmids with approximate sizes of 1.4, 4.9, 5.4, 9.3, 10, 29, 44, 52, and 150 megadaltons(Md). By treating the wild type of B. t k HD-1 with either SDS or EtBr as curing agent, 26 cured mutants of the bacterium were obtained, 9 of them were crystallifereous(cry+) and the others acrystallifereous(cry-). Plasmids from B. t k HD-1 were transferred to B. cereus 569 strR cry- recipients(Bc569 M1). Among 13 isolates of Bc569 M1 transcipient, 11 of them were capable of producing the crystal toxic proteins. The plasmid patterns of Bc569 M1 transcipients and partially curved mutants of B. t k HD-1 on agarose gel electrophoresis suggested that the 29 and 44Md plasmids should be involved in the production of crystalline toxic proteins.

• Proceedings of the Korean Geotechical Society Conference
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• 1993.10b
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• pp.103-118
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• 1993

The application of T.B.M tunnelling has been progressively increased since the first entrance into Korea in 1985 and especially, its higher performance and safety is widely proved as a generalized tunnelling in hardrock tunnel construction, comparing wi th conventional method. This case announcement will be much helpful for your general understanding of T.B.M tunnelling and the development of tunneling technology by introducing the brief methods and construction results from the actual application cases of T.B.M tunnelling in Ulsan Water Supply Tunnel Project, the longest tunnel in Korea under construction by YOU ONE. Co.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.32 no.3
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• pp.235-240
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• 1996

Forecasts of monthly landings of walleye pollock, Theragra chalcogramma, in Korea were carried out by the seasonal Autoregressive Integrated Moving Average(ARlMA) model. The Box - Cox transformation on the walleye pollock catch data handles nonstationary variance. The equation of Box - Cox transformation was Y'=($Y^0.31$_ 1)/0.31. The model identification was determined by minimum AIC(Akaike Information Criteria). And the seasonal ARlMA model is presented (1- O.583B)(1- $B^1$)(l- $B^12$)$Z_t$ =(l- O.912B)(1- O.732$B^12$)et where: $Z_t$=value at month t ; $B^p$ is a backward shift operator, that is, $B^p$$Z_t$=$Z_t$-P; and et= error term at month t, which is to forecast 24 months ahead the walleye pollock landings in Korea. Monthly forecasts of the walleye pollock landings for 1993~ 1994, which were compared with the actual landings, had an absolute percentage error(APE) range of 20.2-226.1 %. Thtal observed annual landings in 1993 and 1994 were 16, 61OM/T and 1O, 748M/T respectively, while the model predicted 10, 7 48M/T and 8, 203M/T(APE 37.0% and 23.7%, respectively).