• Journal of the Mineralogical Society of Korea
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• v.6 no.2
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• pp.116-121
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• 1993

A single crystla of zeolite $Na_{78}Rb_{28}-X$ (approximate composition) was prepared by exposing $Na_{92}-X$ at $350^{\circ}C$ to 0.1 Torr of rubidium vapor, and its structure was determined by single-crystal x-ray diffraction methods in the cubic space group, Fd3, ${\alpha}=25.045(4){\AA}$. The structure was refined to the final error indices $R_1=0.082$ and $R_2=0.084$ with 353 for which I>$3{\sigma}(I)$. Only about 28 of the 92 $Na^+$ ions per unit cell were reduced and only about 14 of the 28 $Na^0$ atoms produced were retained within the zeolite. A $Na_5{^{4+}}$ cluster is present within each sodalite cavity. It is a centered tetrahedron (like $CH_4$) with bond $length=2.80(2){\AA}$ and angle tetrahedral by symmetry, and shows the full symmetry of its site. $T_d$, at the center of the sodalite cavity. Each of the four terminal atoms of the $Na_5{^{4+}}$ cluster bond to three framework oxygens at $2.36(2){\AA}$. At the centers of some double 6-rings are sodium atoms which bridge linearly between $Na_5{^{4+}}$ clusters to form agglomerations such as short zig-zag chains $Na_5{^{4+}}$ clusters. Delocalized electrons, located primarily on the sodiums at centers of the sodalite and (likely) double-six-ring cavities, contribute to the stability of the clusters.

• The Korean Journal of Pharmacology
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• v.26 no.2
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• pp.135-144
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• 1990

The vascular responses to the vasoactive drugs were evaluated using aortic ring preparations obtained from propylthiouracil (PTU)-treated rats. The body weights and the levels of serum thyroxine $(T{_4})$ and triiodothyronine $(T{_3})$ were significantly decreased in propylthiouracil-treated rats as compared with those in age-matched control rats. The contractile responses to norepinephrine and potassium and calcium ions were significantly attenuated in aortic rings of PTU-treated rats 4 weeks after when compared with those from age-matched control animals. By the PTU treatment, however, the sensitivity to norepinephrine but not to calcium was decreased while the maximal responses to norepinephrine and calcium were reduced together. The attenuated contractile responses to the vasoconstrictors in PTU-treated rats are ascribed to the decreased ability of the muscle cells to contract. On the other hand, the relaxation responses induced by acetylcholine and histamine (endothelium-dependent relaxants) and isoproterenol and sodium nitroprusside (endothelium-independent relaxants) had tendencies to be augmented in aortic rings of PTU-treated rats when compared with those of age-matched control animals. However, the sensitivities to the endothelium-independent relaxants were different between PTU-treated and control rats whereas those to the endothelium-dependent relaxants were not. These results suggest that the altered vascular responsiveness in the PTU-treated rats seems to be due to the alteration of smooth muslce cells rather than the Influence of endothelium, and that this change is slowly progressive after hypothyroidism is evident.

• Advances in Traditional Medicine
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• v.8 no.3
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• pp.228-235
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• 2008

This study was conducted to evaluate the estrogen activity of silkworm (Bombyx mori) pupa extracts and their fractions. Powdered samples of freeze-dried silkworm pupa were extracted at room temperature (RT), $40^{\circ}C$, $60^{\circ}C$, $80^{\circ}C$, and $100^{\circ}C$ in water (D.W), chloroform, ethyl acetate, and methanol for 6h and then filtered (0.45 um). The extracts were then freeze-dried. The estrogenic activity of these extracts was then investigated by competition binding assays using estrogen receptor ${\alpha}\;(ER{\alpha})$ and $ER{\beta}$, and by evaluating their effects on the proliferation of the human breast cancer cell line, MCF-7. Among the extracts evaluated, water extracts prepared at RT showed the highest binding affinity to $ER{\alpha}$ ($IC_{50}$, 1.76 ug/ml) and $ER{\beta}$ ($IC_{50}$, 0.07 ug/ml). In addition, MCF-7 cells that were treated with 62.5 ug/ml of the RT extract showed the greatest increase in proliferation (2-fold; 1291.79%) when compared to control cells (659.82%). Next, the water extract that was prepared at RT (sample 1) was dissolved in D.W. and further fractionated using a Dowex 50W - 8X ($H^+$) column. The flow-through and wash were then pooled together and freeze-dried (sample 2). The bound materials were then eluted with 20 mM NaCl, after which they were applied to a Dowex 1X2 - 200 ($Cl^-$) column and washed with D.W. to remove the sodium ions. The eluants were then freeze-dried (sample 3). Of these fractions, sample 2 showed the highest binding affinity to ER{\alpha} ($IC_{50}$, 1.44 ug/ml) and $ER{\beta}$ ($IC_{50}$, 1.18 ug/ml). In addition, MCF-7 cells that were treated with sample 2 (15.6 ug/ml) showed the largest increase in growth (1159.39%) when compared to control cells (525.26%). Taken together, these results suggest that the fraction of the RT water extract of silkworm pupa referred to as sample 2 may be useful as a phytoestrogen.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.8
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• pp.930-937
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• 2007

Korean pine(Pinus densiflora) bark was evaluated for its adsorption capacity of Cu(II) ions from aqueous solution by running a series of batch experiments. Prior to the tests, the milled barks were treated with 1 N NaOH or 1 N HCl to examine the effect of surface modification. For comparison, untreated bark was tested under same condition. Within the tested pH range between 3 and 6, NaOH treatment increased Cu(II) adsorption capacity by $139\sim184%$, while HCl treatment decreased it by $37\sim42%$. Maximum copper ion uptake by bark was observed at pH $5\sim6$, but pH of solution was not a potent influence. A pseudo second-order kinetic model fitted well for the sorption of copper ion onto bark. For NaOH-treated bark, the calculated sorption capacity$(q_e)$ increased from 6.58 to 12.77 mg/g, while the equilibrium rate constant$(k_2)$ decreased from 0.284 to 0.014 g/mg/min as initial Cu(II) concentration doubled from 100 mg/L. A batch isotherm test using NaOH-treated bark showed that equilibrium sorption data were represented by both the Langmuir model and the Freundlich model. It was confirmed that carboxylic acid of bark was involved in the Cu(II) adsorption. For NaOH-treated bark, in particular, carboxylate ion produced by hydrolysis or saponification appeared to be a major functional roup responsible for the enhanced Cu(II) sorption.

• Microbiology and Biotechnology Letters
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• v.34 no.1
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• pp.28-34
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• 2006

A native extracellular acid phosphatase, phytase (EC 3.1.3.8), from Bacillus coagulans IDCC 1201 (commercially known as Lactobacillus sporogenes) used as probiotics, was characterized. Though some strains of B. coagulans have been evaluated with regard to several health-promoting effects, it has not been reported to produce phytase. Partially purified phytase front the strain IDCC 1201 had a pH optimum of 4.0 and a temperature optimum of $50^{\circ}C$, respectively. The requirement for divalent cations was studied and cobalt ion remarkably increased the enzyme activity. The removal of metal ions from the enzyme by EDTA decreased activity below 50%. The enzyme activity depleted restored when the assay was performed in the presence of $Co^{2+}$. Also, $Co^{2+}$ is the most active stimulator and has unique activation effect at high temperature. The phytase was specific for sodium phytate and p-nitrophenylphosphate, which is different from other known Bacilli phytases. The putative amino acid sequences of the phytase from B. coagulans IDCC 1201 were very similar to that of the phytase from B. subtilis strain 168. Based on these data, we concluded that the phytase from B. coagulans IDCC 1201 is a $Co^{2+}$-dependent acid phosphatase. Therefore, the strain B. coagulans IDCC 1201 is thought to be a valuable addititive for livestocks as well as a beneficial probiotics for human.

• Microbiology and Biotechnology Letters
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• v.30 no.2
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• pp.142-150
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• 2002

Streptomyces polychromogenes IFO 13072 was used as a strain producing cholesterol oxidase(EC 1.1.3.6). The conditions of cholesterol oxidase production were investigated. The optimum composition of medium for production of the enzyme was 1% dextrin, 0.5% casamino acid, 0.1% $KH_2$PO$_4$, 0.5% $NaNO_3$ and 0.05% $MgSO_4$(pH 7.3). The enzyme was purified specifically by cholesterol affinity column chromatography with a yield of 23.2%. The purified enzyme showed a single polypeptide on SDS-PAGE and the molecular weight was estimated about 52,000 daltons. The optimum pH and temperature of the cholesterol oxidase were pH 7.0 and $37^{\circ}C$, respectively. The enzyme was stable in the range of pH 6.0~7.0 and $25^{\circ}C$. The cholesterol oxidase activity was strongly inhibited by metal ions such as $Hg^{2＋}$ and $Fe^{2＋}$ and inhibitors such as dithiothreitol, mercaptoethanol and isonicotinic acid. The Michaelis constant(Km) for the cholesterol was found to be 25 mM by Lineweaver-Burk plot analysis.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.7
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• pp.729-734
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• 2008

The higher valence state of iron i.e., Fe(VI) was employed for the treatment of Cu(II)-EDTA in the aqueous/waste waters. The ferrate(VI) was prepared through wet oxidation of Fe(III) by sodium hypochlorite. The purity of prepared Fe(VI) was above 93%. The stability of Fe(VI) solution decreased as solution pH decreased through self decomposition. The reduction of Fe(VI) was obtained by using the UV-Visible measurements. The dissociation of Cu(II)-EDTA complex through oxidation of EDTA using Fe(VI) and subsequent treatment of organic matter and metal ions by Fe(III) reduced from Fe(VI) in bench-scale of continuous flow reactor were studied. The removal efficiencies of copper were 69% and 79% in pH control basin and reactor, respectively, at 120 minutes as retention time. In addition, Cu(II)-EDTA in the reactor was decomplexated more than 80% after 120 minutes as retention time. From this work, a continuous treatment process for the wastewater containing metal and EDTA by employing Fe(VI) as muluti-functional agent was developed.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.4
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• pp.355-367
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• 2016

Soil salinization refers to the buildup of salts in soil to a level toxic to plants. The major factors that contribute to soil salinity are the quality, the amount and the type of irrigation water used. The presented review discusses the different sources and causes of soil salinity. The effect of soil salinity on biological processes of plants is also discussed in detail. This is followed by a debate on the influence of salt on the nutrient uptake and growth of plants. Salinity decreases the soil osmotic potential and hinders water uptake by the plants. Soil salinity affects the plants K uptake, which plays a critical role in plant metabolism due to the high concentration of soluble sodium ($Na^+$) ions. Visual symptoms that appear in the plants as a result of salinity include stunted plant growth, marginal leaf necrosis and fruit distortions. Different strategies to ameliorate salt stress globally include breeding of salt tolerant cultivars, irrigation to leach excessive salt to improve soil physical and chemical properties. As part of an ecofriendly means to alleviate salt stress and an increasing considerable attention on this area, the review then focuses on the different plant growth promoting bacteria (PGPB) mediated mechanisms with a special emphasis on ACC deaminase producing bacteria. The various strategies adopted by PGPB to alleviate various stresses in plants include the production of different osmolytes, stress related phytohormones and production of molecules related to stress signaling such as bacterial 1-aminocyclopropane-1-carboxylate (ACC) derivatives. The use of PGPB with ACC deaminase producing trait could be effective in promoting plant growth in agricultural areas affected by different stresses including salt stress. Finally, the review ends with a discussion on the various PGPB activities and the potentiality of facultative halophilic/halotolerant PGPB in alleviating salt stress.

• Korean Chemical Engineering Research
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• v.47 no.4
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• pp.424-429
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• 2009

The effects of $Na_2O$, $SiO_2$ and $H_2O$ contents of the synthetic mixtures prepared from water glass on the crystallinity and crystallite size of sodalite were studied. The composition of the synthetic mixtures described by $x\;Na_2O{\cdot}y\;SiO_2{\cdot}Al_2O_3{\cdot}z\;H_2O$ was varied within x=2.5~7.5, y=1.4~3.0, z=140~400. The hydrothermal reaction was carried out at $140^{\circ}C$ for 2 days. High content of $Na_2O$ resulted in the high crystallinity and small crystallite of sodalite. The $SiO_2/Al_2O_3$ molar ratios of around 2 were suitable for the synthesis of sodalite, and produced zeolite species were varied by the $H_2O$ content. Sodalite was mainly obtained with a high crystallinity from the synthetic mixtures with $SiO_2/Al_2O_3$ molar ratio of around 2 and high content of $Na_2O$. The high content of sodium ions caused a decrease in the particle sizes because of their role of structure directing agent.

• Korean Chemical Engineering Research
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• v.47 no.2
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• pp.190-194
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• 2009

In this study sodium dodecyl sulfate (SDS), which was anionic surfactant, was added for forming micelles to remove iron ion that could be contained with small amount in industrial water. Then aggregates binding between iron ions and micelles were rejected by a ceramic microfiltration membrane. As result of SDS concentration effect on removal rates of iron and SDS in modified iron solution, the removal rate of iron was the highest value of 92.26% and the removal rate of SDS was 61.10% a little higher than the result of calcium ion at 8 mM which was CMC (Critical micelle concentration) of SDS. As final resistance of membrane fouling $R_f$ increased the more at the higher SDS concentration, it showed the highest value at 4 mM and the lowest at 10 mM of SDS. The final permeate flux $J_{180}$ had the highest value and the largest total permeate volume could be finally acquired at SDS 10 mM. In case of CMC 8 mM, low $R_f$ was shown as same as that of 10 mM until 80 minutes of operation, and tended to increase dramatically to 120 minutes and increase slowly again until 180 minutes.