• Journal of Sensor Science and Technology
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• v.16 no.5
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• pp.337-341
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• 2007

$CsSrCl_{3}$ crystal was grown using Czochralski method from equimolar mixture of CsCl and $SrCl_{2}$. The spectrum range of the luminescence excited by 205 nm of wavelength was about $280{\sim}550$ nm, and its peak emission appeared at 343 nm. The luminescence decay curve of the $CsSrCl_{3}$ revealed two exponential components with time constants of 60 ns and 700 ns. The energy resolution for $^{137}Cs$ 662 keV ${\gamma}$-ray was 10.3 %. The pulse shape was linear at high energy, but some deviation existed in the low energy region.

• Biomolecules & Therapeutics
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• v.8 no.4
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• pp.293-298
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• 2000

Bergenin is a C-glucoside of 4-O-methyl gallic acid that has been isolated from the cortex of Mallotus japonicus (Euphorbiaceae). Acetylbergenin was synthesized by acetylation from bergenin to increase lipophilic and physiological activities. The therapeutic effects of bergenin and acetylbergenin were evaluated against carbon tetrachloride ($CCl_4$)-induced hepatotoxicity in rats. Bergenin and acetylbergenin were administered orally once daily for successive 5 days, after the intraperitoneal injection of a mixture 0.5 m1/kg of $CCl_4$ in olive oil (1:1). The substantially elevated serum enzymatic activities of alanine/aspartate aminotransferase, sorbitol dehydrogenase and ${\gamma}$-glutamyltransferase induced by $CCl_4$ were restored towards normalization by posttreatment with bergenin and acetylbergenin. Bergenin and acetylbergenin also significantly prevented the elevation of hepatic malondialdehyde formation and depletion of glutathione content induced by $CCl_4$ in a dose dependent fashion. In addition, the decreased activities of glutathione S-transferase and glutathione reductase were restored towards normalization. These results suggest that therapeutic effects of bergenin and acetylbergenin may be related complex mechanisms that involve prevention of lipid peroxidation and preservation of hepatic GSH. The results of this study clearly indicate that bergenin and acetylbergenin have potent hepatothrapeutic action against $CCl_4$-induced hepatotoxicity in rats. In addition, acetylbergenin 50 mgHg showed almost the same levels of hepatoprotective activity as those of bergenin 100 mgAg, indicating the fact that lipophilic acetylbergenin is more effective in the hepatoprotective action against $CCl_4$ than bergenin.

• Microbiology and Biotechnology Letters
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• v.19 no.5
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• pp.514-520
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• 1991

Direct synthesis of cyclodextrin (CD) from extruded insoluble corn starch without liquefaction procedure using cyclodextrin glucanotransferase (CGTase) was carried out. Increased CD production rate and yield were achieved in heterogeneous enzyme reaction system containing extruded corn starch compared with those of conventional system employing liquefied or partially cyclized starch. At extruded starch concentration of 100 g/l the CD concentration and conversion yield were reached up to 54 g/l and 0.54, respectively. High purity of $\alpha \beta \gamma$-CDs without accumulation of undesirable malto-oligosaccharides was produced, furthermore, the residual extruded starch was easily separated by centrifugation from reaction mixture, whlch will facilitate the purification procedure. Granular structure of extruded starch was observed by SEM to investigate enzyme reaction mechanism. Supplemental addition of $\alpha$-amylase enhanced slightly the initial CD production rate, but it decomposed produced CD at the late stage. Various! extruded raw starches, such as, corn, rice, and barley were also suitable substrates for CD production.

• Journal of the Korean Ceramic Society
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• v.28 no.5
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• pp.399-405
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• 1991

Mullite-PSZ powders were synthesized by the sol-gel process using Al(sec-OC4H9)3, Si(OC2H5)4, ZrOCl2$.$8H2O and YCl3 solution and the characteristics of synthesized powders were studied. The sinterability and mechanical properties of powder compacts sintered at 1670$^{\circ}C$ for 4hr were also studied for various PSZ contents. ${\gamma}$-Al2O3(Al-Si spinel) formed at 980$^{\circ}C$ from amorphous dried gel, and mullite as well as ZrO2 formed above 1200$^{\circ}C$. At the room temperature, ZrO2 was a mixture of tetragonal and monoclinic phases. The specimens were densified to 97∼98% except the specimen containing 25 vol% PSZ which showed the relative density of 94%. The K1c value increased with the PSZ content and showed a maximum value of 4.1 MN/m3/2 at 25 vol% PSZ; this value was about 50% higher than that of the mullite without PSZ. Flexural strength had a maximum value of 280 Mn/㎡ at 20 vol% PSZ. In contrast, at 25 vol%, the flexural strength was even lower than that of the mullite possibly due to higher porosity of 6%.

• Archives of Pharmacal Research
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• v.16 no.2
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• pp.134-139
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• 1993

The molecular structure of acemetacin, 1-(4-chlorobenzoyl)-5-methoxy-2-methyl-1H-indole-3-acetic acid carboxymethyl ester, was determined by single cystal X-ray diffraction analysis. The compound was recrystallized from a mixture of acetone and water in triclinic, space group P1, with a=7.796(1), b=10.245(2), c=13.542(3)$\AA,\;\alpha=97.35(1),\;\beta=96.34(1),\;\gamma=107.06(1)^\circ$, and Z=2. The calculated density is 1.422; the observed value is $1.42\;g/cm^3$. The structure was solved by the direct method and refined by full matrix least-squares procedure to the final R value of 0,037 for 2960 independent reflections. There are water molecules, which are thought to be co-crystallized during the evaporation procedure, with the ratio of one water per compound molecule in the crystal. The conformation of the compound is found to be very similar to that of indomethacin. The molecules are stabilized by three O-H.....O type intermolecular hydrogen bonds between the oxygen of water molecule and those of the compound.

• Nuclear Engineering and Technology
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• v.56 no.8
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• pp.3307-3314
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• 2024

For traditional spent fuel shielding materials, due to physical and chemical defects and cost constraints, they have been unable to meet the needs. Therefore, this paper carries out the first discussion on the application and performance of bismuth in neutron shielding by establishing Monte Carlo simulation on the neutron flux model of shielded spent fuel. Firstly, functional fillers such as bismuth oxide, lead oxide, boron oxide, gadolinium oxide and tungsten oxide are added to the matrices to compare the shielding rates of aluminum alloy matrix and silicone rubber matrix. The shielding rate of silicone rubber mixture is higher than aluminum alloy mixture, reaching more than 56%. The optimal addition proportion of bismuth oxide and lead oxide is 30%, and the neutron radiation protection efficiency reaches 60%. Then, the mass attenuation coefficients of bismuth oxide, lead oxide, boron oxide, gadolinium oxide and tungsten oxide in silicone rubber matrix are simulated with the change of functional fillers proportion and neutron energy. This simulation result shows that the mixture with functional fillers has good shielding performance for low energy neutrons, but poor shielding effect for high energy neutrons. Finally, in order to further evaluate the possibility of replacing lead oxide with bismuth oxide as shielding material, the half-value layers and various properties of bismuth oxide and lead oxide are compared. The results show that the shielding properties of bismuth oxide and lead oxide are basically the same, and the mechanical properties, heat resistance, radiation resistance and environmental protection of bismuth oxide are better than that of lead oxide. Therefore, in the case of neutron source strengths in the range of 0.01-6 MeV and secondary gamma rays produced below 2.5 MeV, bismuth can replace lead in neutron shielding applications.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.9
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• pp.1336-1343
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• 2005

In the present study, we screened candidates for enhancing insulin action and secretion from Cinnamomum camphora (CC) fractions, in 3T3-L1 adipocytes and Min6 cells by investigating insulin- stimulated glucose uptake and glucose-stimulated insulin secretion, respectively. CC were extracted by $70\%$ ethanol followed by XAD-4 column chromatography with serial mixture solvents of methanol and water, and the fractional extractions were utilized for determining insulin action and secretion, and $\alpha$-glucoamylase suppressing activity, A significant insulin-stimulated glucose uptake was observed in 3T3-L1 adipocytes, giving 0.5 or $5{\mu}g/mL$ of $40\%\;and\;60\%$ methanol fractions plus 0.2 nM insulin, compared to the treatment of DMSO plus 0.2 nM insulin. The treatments of $40\%\;and\;60\%$ methanol fractions plus 0.2 nM insulin reached the glucose uptake of 10 nM insulin treatment. The $40\%$ methanol fraction increased triglyceride accumulation by stimulating differentiation and triglyceride synthesis similar to pioglitazone, PPAR-$\gamma$ agonist. No inhibition of $\alpha$-glucoamylase activity of CC fractions was observed. They did not modulate the insulin secretion capacity In either low or high glucose media. These results suggest that $40\%$ methanol fraction contains a potential insulin sensitizer to have a similar function of PPAR-$\gamma$ agonist. Crude CC extract may improve glucose utilization by enhancing insulin-stimulated glucose uptake without elevating glucose stimulated insulin secretion.

• IMMUNE NETWORK
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• v.2 no.1
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• pp.41-48
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• 2002

Background: Viral antigens presented on the cell surface in association with MHC class I molecules are recognized by CD8+ T cells. MHC restricted peptides are important in eliciting cellular immune responses. As peptide antigens have a weak immunigenicity, pH-sensitive liposomes were used for peptide delivery to induce effective cytotoxic T lymphocyte (CTL) responses. In the previous study, as the HBx peptides could induce specific CTLs in vitro, we tested whether the HLA-A2/$K^b$ transgenic mice that were immunized by HBx-derived peptides could be protected from a viral challenge. Methods: HBx-peptides encapsulated by pH-sensitive liposomes were prepared. $A2K^b$ transgenic mice were immunized i.m. on days one and seven with the indicated concentrations of liposome-encapsulated peptides. Three weeks later, mice were infected with $1{\times}10^7pfu$/head of recombinant vaccinia virus (rVV)-HBx via i.p. administration. The ovaries were extracted from the mice, and the presence of rVV-HBx in the ovaries was analyzed using human TK-143B cells. IFN-${\gamma}$ secretion by these cells was directly assessed using a peptide-pulsed target cell stimulation assay with either peptide-pulsed antigen presenting cells (APCs), concanavalin A ($2{\mu}g/ml$), or a vehicle. To generate peptide-specific CTLs, splenocytes obtained from the immunized mice were stimulated with $20{\mu}g/ml$ of each peptide and restimulated with peptide-pulsed APC four times. The cytotoxic activity of the CTLs was assessed by standard $^{51}Cr$-release assay and intracellular IFN-${\gamma}$ assay. Results: Immunization of these peptides as a mixture in pH-sensitive liposomes to transgenic mice induced a good protective effect from a viral challenge by inducing the peptide-specific CD8+ T cells. Mice immunized with $50{\mu}g/head$ were much better protected against viral challenge compared to those immunized with $5{\mu}g$/head, whereas the mice immunized with empty liposomes were not protected at all. After in vitro CTL culture by peptide stimulation, however, specific cytotoxicity was much higher in the CTLs from mice immunized with $5{\mu}g/head$ than $50{\mu}g/head$ group. Increase of the number of cells that intracellular IFN-${\gamma}$ secreting cell among CD8+ T cells showed similar result. Conclusion: Mice immunized with XEPs within pH-sensitive liposome were protected against viral challenge. The protective effect depended on the amount of antigen used during immunization. XEP-3-specific CTLs could be induced by peptide stimulation in vitro from splenocytes obtained from immunized mice. The cytotoxic effect of CTLs was measured by $^{51}Cr$-release assay and the percentage of accumulated intracellular IFN-${\gamma}$ secreting cells after in vitro restimulation was measured by flow cytometric analysis. The result of $^{51}Cr$-release cytotoxicity test was well correlated with that of the flow cytometric analysis. Viral protection was effective in immunized group of $50{\mu}g/head$, while in the in vitro restimulation, it showed more spectific response in $5{\mu}g$/head group.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.5
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• pp.398-402
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• 2012

Synthesis of $Li_2MnSiO_4$ was attempted by the conventional solid-state reaction method, and the phase formation behavior according to the change of the calcination condition was investigated. When the mixture of the three source materials, $Li_2O$, MnO and $SiO_2$ powders, were used for calcination in air, it was difficult to develop the $Li_2MnSiO_4$ phase because the oxidation number of $Mn^{2+}$ could not be maintained. Therefore, two-step calcination was applied: $Li_2SiO_3$ was made from $Li_2O$ and $SiO_2$ at the first step, and $Li_2MnSiO_4$ was synthesized from $Li_2SiO_3$ and MnO at the second step. It was easy to make $Li_2MnSiO_3$ from $Li_2O$ and $SiO_2$. $Li_2MnSiO_4$ single phase was developed by the calcination at $900^{\circ}C$ for 24 hr in Ar atmosphere as the oxidation of $Mn^{2+}$ was prevented. However, the $Li_2MnSiO_4$ was ${\gamma}-Li_2MnSiO_4$, one of the polymorph of $Li_2MnSiO_4$, which could not be used as the cathode materials in Li-ion batteries. By applying the additional low temperature annealing at $400^{\circ}C$, the single phase ${\beta}-Li_2MnSiO_4$ powder was synthesized successfully through the phase transition from ${\gamma}$ to ${\beta}$ phase.

• Food Science and Preservation
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• v.23 no.3
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• pp.326-334
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• 2016

Omija (Schizandra chinensis) extract (OE) was fermented by using Lactobacillus plantarum EJ2014 to produce a beverage fortified with gamma-aminobutyric acid (GABA). After 2 days of fermentation in the presence of 2% monosodium glutamate (MSG) and 0.5% yeast extract (YE), the four-fold-diluted OE showed a higher viable cell count ($2.2{\times}10^9CFU/mL$) and lower acidity (1.2%) than that of the unfermented OE. In particular, addition of MSG as a precursor resulted in a small increase in the initial pH. MSG (2%) was completely converted to GABA (0.92%) during lactic acid bacteria fermentation for 3 days. Furthermore, the acidity of the fermented OE decreased from 1.74% to 0.56%. In addition, the original red color of the OE disappeared during LAB fermentation. However, when the fermented OE was mixed with 50% of the original OE, the original red color was recovered, with 19.56 and 13.92 for Hunter L and a values, respectively. The mixture of 50% original OE and 50% fermented OE showed the highest sensory score including the highest overall preference. In conclusion, the OE fortified with GABA and probiotics was produced by fermentation with a static culture, L. plantarum EJ2014.