• Journal of Plant Biotechnology
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• v.38 no.2
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• pp.162-168
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• 2011

High salinity is a common stress condition that adversely affects plant growth and crop production. In response to various environmental stresses, plants activate a number of defense genes that function to increase the tolerance. To isolate Arabidopsis genes that are involved in abiotic stress responses, we carried out genetic screening using various mutant lines. Among them, the blh8 ($\b{B}$EL1-$\b{L}$ike $\b{H}$omeodomain $\underline{8}$) mutant specifically shows chlorotic phenotypes to ionic (specifically, $Na^+$ and $K^+$) stresses, but no differences in root growth. In addition, BLH8 is related to plant development and abiotic stress as predicted by a Graphical Gaussian Model (GGM) network program. It implies that BLH8 functions as a putative transcription factor related to abiotic stress responses. Collectively, our results show that gene network analysis is a useful tool for isolating genes involved in stress adaptation in plants.

• Bulletin of the Korean Chemical Society
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• v.33 no.1
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• pp.48-54
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• 2012

The $[Fe_4S_4]^{2+}$ clusters with 2-, 3-, and 4-pyridinemethanethiolate (S2-Pic, S3-Pic, and S4-Pic, respectively) terminal ligands have been synthesized from the ligand substitution reaction of the $(^nBu_4N)_2[Fe_4S_4Cl_4]$ (I) cluster. The new $(^nBu_4N)_2[Fe_4S_4(SR)_4]$ (R = 2-Pic; II, 3-Pic; III, 4-Pic; IV) clusters were characterized by FTIR and UV-Vis spectroscopy. Cluster II was crystallized in the monoclinic space group C2/c with a = 24.530 (5) $\AA$, b = 24.636(4) $\AA$, c = 21.762(4) $\AA$, ${\beta}=103.253(3)^{\circ}$, and Z = 8. The X-ray structure of II showed two unique 2:2 site-differentiated $[Fe_4S_4]^{2+}$ clusters due to the bidentate-mode coordination by 2-pyridinemethanethiolate ligands. Cluster III was crystallized in the same monoclinic space group C2/c with a = 26.0740(18) $\AA$, b = 23.3195(16) $\AA$, c = 22.3720(15) $\AA$, ${\beta}=100.467(2)^{\circ}$, and Z = 8. The 3-pyridinemethanethiolate ligand of III was coordinated to the $[Fe_4S_4]^{2+}$ core as a terminal mode. Cluster IV with 4-pyridinemethanethiolate ligands was found to have a similar structure to the cluster III. Fully reversible $[Fe_4S_4]^{2+}/[Fe_4S_4]^+$ redox waves were observed from all three clusters by cyclic voltammetry measurement. The electrochemical potentials for the $[Fe_4S_4]^{2+}/[Fe_4S_4]^+$ transition decreased in the order of II, III and IV, and the reduction potential changes by the ligands were explained based on the structural differences among the complexes. The complex III was reacted with sulfonium salt of $[PhMeSCH_2-p-C_6H_4CN](BF_4)$ in MeCN to test possible radical-involving reaction as a functional model of the [$Fe_4S_4$]-SAM (S-adenosylmethionine) cofactor. However, the isolated reaction products of 3-pyridinemethanethiolate-p-cyanobenzylsulfide and thioanisole suggested that the reaction followed an ionic mechanism and the products formed from the terminal ligand attack to the sulfonium.

• Land and Housing Review
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• v.4 no.1
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• pp.119-124
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• 2013

Generally, the characteristic of nanofiltration membranes were catagorized into charged membrane, sieve effect, interaction between membarnes and target solutes. This study aims to investigate the effect item of heavy metal separation with view of charge nanofiltration membranes. The experiments of nanofiltration were conducted by nanofiltration set-up with operational pressure of 0.24 MPa at $25^{\circ}C$ by using synthetic wastewater containing 0.1mg/L of Cr, Fe, Cu, Zn, As, Sn, Pb. Nanofiltration membranes rejected heavy metals much better than chloride, sulfate and TOC, of which concentration in synthetic wastewater was higher than that of heavy metals. To consider rejection characteristics of various metals by nanofiltration membranes, separation coefficient, which is the molar conductivity ratio of the metal permeation rate to the chloride ion or TOC permeation rate, was introduced. In spite of different materials and different nominal salt rejection of nanofiltration membrane used, the separation coefficients of metals were nearly the same. These phenomena were observed in the relationship between the molar conductivity and the separation coefficient for heavy metals.

• The Korean Journal of Ecology
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• v.27 no.6 s.122
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• pp.355-361
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• 2004

In order to elucidate the ecophysiological characteristics of coastal plants, we collected them on salt marsh and sand dune, and analyzed inorganic ($Na^+,\;K^+,\;Mg^{2+},\;Ca^{2+}$) and organic solutes (soluble carbohydrate, glycine betaine). Chenopodiaceous plant species (Atriplex gmelini, Salicornia europaea, Salsola collina, Suaeda glauca, Suaeda japonica) showed a tendency to accumulate inorganic ions such as $Na^+\;and\;Cl^-$ instead of $K^+$. However, Chenopodium serotinum which lives in ruderal habitat contained more $K^+$ and less $Na^+$ than the other Chenopodiaceous plants. Most Chenopodiaceous plant species maintained very low level of soluble $Ca^{2+}$ and relatively low concentration of carbohydrates and showed high concentration of glycine betaine which is among the most effective known compatible solutes in the leaves of plant under drought and saline conditions. On the other hand, plant species which belong to Gramineae (Ishaemum anthephoroides, Phragmites communis, Zoysia sinica) and Cyperaceae (Carex kobomugi, Carex pumila) absorbed $K^+$ selectively and excluded $Na^+\;and\;Cl^-$ effectively regardless of habitat conditions, and they accumulated more soluble carbohydrate as osmoticum than Chenopodiaceous plants. These results suggested that physiological characteristics such as high storage capacity for inorganic ions (especially alkali cations, chloride) and the accumulation of glycine betaine in chenopodiaceous plants and $K^+$-preponderance, an efficient regulation of ionic uptake (exclusion of $Na^+\;and\;Cl^-$) and the accumulation of soluble carbohydrate in monocotyledonous plants enable them to grow dry and saline habitats.

• Microbiology and Biotechnology Letters
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• v.31 no.4
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• pp.368-376
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• 2003

Cyclodextrin glucanotransferase (CGTase) from Paenibacillus sp. JB-13 was immobilized on various carriers by several immobilization methods such as ionic binding, covalent linkage and ultrafiltration to improve the process performance. The ultrafiltration and covalent linkage with CNBr-activated sepharose 4B were found as the best method for immobilization of CGTase. The ability of CGTase immobilization onto CNBr-activated sepharose 4B was as high as 18,000 units/g resin when the conditions was as follows: contact time 9 hrs at $37^{\circ}C$, pH 6.0, 100 nm and enzyme loading 24,000 units/g resin. The optimum conditions for production of 2-O-$\alpha$-D-Glucopyranosyl L-Ascorbic acid by immobilized CGTase turned out to be: pH 5.0, temperature $37^{\circ}C$, 20% substrate solution containing 8% (w/v) of soluble starch and 12% (w/v) of L-ascorbic acid sodium salt, 100 rpm, far 25 hrs and with 800 units of immobilized CGTase/ml substrate solution. Moreover the CGTase activity could be stably maintained for 8 times of repetitive reactions after removing products by ultrafiltration through YM 10 membrane.

• Membrane Journal
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• v.29 no.2
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• pp.88-95
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• 2019

Hydrocarbons containing carbon double bonds are generally called olefins and it is extensively used in petro-chemical industry as essential base material. Especially, olefins are essential in polymer synthesis and thus the effective separation and purification of olefins from gas mixture are very important and it gives significant positive effect on the future industrial development. In this study, we fabricated polymeric composite membrane based on poly(1-trimethylsilyl-1-propyne) (PTMSP) for propylene/nitrogen separation and enhancement of its separation performance by grafting amphiphilic copolymer. Furthermore, to accelerate facilitated transport for propylene molecules, Ag salt ($AgBF_4$) and ionic liquid ($EMIM-BF_4$) was incorporated to polymer composite membranes. The neat PTMSP membrane exhibited extremely high gas permeance and low gas selectivity due to its high free volume. To address this issue, PTMSP was grafted with poly(oxyethylene glycol methacrylate) (POEM) and poly(ethylene glycol) behenyl ether methacrylate (PEGBEM). Additionally, the additives such as $AgBF_4$ and $EMIM-BF_4$ further increased the propylene permeance, resulting in increment of propylene/nitrogen selectivity.

• Membrane Journal
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• v.33 no.4
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• pp.149-157
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• 2023

Covalent organic frameworks (COFs) have shown promise in various applications, including molecular separation, dye separation, gas separation, filtration, and desalination. Integrating COFs into membranes enhances permeability, selectivity, and stability, improving separation processes. Combining COFs with single-walled carbon nanotubes (SWCNT) creates nanocomposite membranes with high permeability and stability, ideal for dye separation. Incorporating COFs into polyamide (PA) membranes improves permeability and selectivity through a synthetic interfacial strategy. Three-dimensional COF fillers in mixed-matrix membranes (MMMs) enhance CO₂/CH₄ separation, making them suitable for biogas upgrading. All-nanoporous composite (ANC) membranes, which combine COFs and metal-organic framework (MOF) membranes, overcome permeance-selectivity trade-offs, significantly improving gas permeance. Computational simulations using hypothetical COFs (hypoCOFs) demonstrate superior CO₂ selectivity and working capacity relevant for CO₂ separation and H₂ purification. COFs integrated into thin-film composite (TFC) and polysulfonamide (PSA) membranes enhance rejection performance for organic contaminants, salt contaminants, and heavy metal ions, improving separation capabilities. TpPa-SO₃H/PAN covalent organic framework membranes (COFMs) exhibited superior desalination performance compared to traditional polyamide membranes by utilizing charged groups to enable efficient desalination through electrostatic repulsion, suggesting their potential for ionic and molecular separations. These findings highlight COFs' potential in membrane technology for enhanced separation processes by improving permeability, selectivity, and stability. In this review, COF applied for the separation process is discussed.

• YAKHAK HOEJI
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• v.42 no.3
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• pp.290-295
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• 1998

To optimize the formulation of acetaminophen liquid suppository, the effect of additives on the physicochemical properties of liquid suppository base was investigated. The physi cochemical properties of P 407/P 188 (15/15%) (abbreviated in 15/15) and P 407/P l88 (15/20%) (abbreviated in 15/20) were measured after the addition of following additives; 2.5% acetaminophen as an active ingredient, vehicle components (5% ethanol, 5% propylene glycol, 5% glycerin), preservatives (0.1% sodium benzoate, 0,1% methylparahydroxybenzoate, 0.1% propylparahydroxybenzoate) and 1% of sodium chloride as an ionic strength controlling agent. Poloxamer gel was prepared with three different buffer solutions (pH 1.2, 4.0 and 6.8) and the physicochemical properties, gelation temperature, gel strength and bioadhesive force, were determined. In the results, the effect of additives on the physicochemical properties was dependent on their bonding capacities including hydrogen bonding and cross-linking bonding. Because the hydrogen-bonding capacities of acetaminophen, ethanol and propylene glycol were smaller than that of poloxamer, the binding force of poloxamer gel became weak by their putting in between poloxamer gel. Therefore, the gelation temperature (15/15, $35.7^{\circ}C$ vs 37.0, 39.4 $38.2^{\circ}C$; 15/20, $29.2^{\circ}C$ vs 31.2, 32.0, $30.3^{\circ}C$) increased, and gel strength (15/15, 4.03 see vs 2.72, 2.08, 3.12sec; 15/20, 300g vs 50, 50, 200g) and bioadhesive force (15/15, $6.8{\times}10^2\;dyne/cm^2$ vs 3.2, 6.0, $6.0{\times}10^2\;dyne/cm^2$; 15/20, $97.3{\times}10^2\;dyne/cm^2$ vs 11.1, 89.5, $92.0{\times}10^2\;dyne/cm^2$) decreased. Furthermore, the binding force of poloxamer gel became strong due to the hydrogen-bonding capacities of glycerin and the cross-liking bonding of sodium salt. Then, the gelation temperature (15/15, 35.0, $32.1^{\circ}C$; 15/20, 26.0, $21.0^{\circ}C$) decreased, and gel strength (15/15, 6.51 see, 300g; 15/20, 500, 650g) and bioadhesive force (15/15, 7.2, $81.6{\times}10^2\;dyne/cm^2$; 15/20, 112.3, $309.2{\times}10^2\;dyne/cm^2$) increased. The effect of pH on the physicochemical properties of poloxamer gel was dependent on the ingredients with which the buffer solutions were prepared. Poloxamer gels prepared with pH 1.2 and 4.0 buffer solutions had the increasing gelation temperature (15/15, 37.5, $38.1^{\circ}C$; 15/20, 33.1, $34.0^{\circ}C$) and the decreasing gel strength (15/15, 2.98, 3.81sec; 15/20, 200, 200g) and bioadhesive force (15/15, $7.0{\times}10^2dyne/cm^2$; 15/20, $74.0{\sim}88.1{\times}10^2dyne/cm^2$) owing to HCl. Poloxamer gel prepared with pH 6.8 buffer solutions had the decreasing gelation temperature (15/15, $27.2^{\circ}C$; 15/20, $22.3^{\circ}C$) and the increasing gel strength (15/15, 400g; 15/20, 550g) and bioadhesive force (15/15, $207.0{\times}10^2dyne/cm^2$; 15/20, $215.0{\times}10^2dyne/cm^2$) due to the cross-linking bonding of $NaH_2PO_4\;and\;K_2HPO_4$.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.5
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• pp.336-340
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• 2009

The issue of acid precipitation and related environmental problems in East Asia has been emerging. To evaluate the acidity and chemical characteristics of rainwater in Korea, its chemical properties during cultivation season from April to October were investigated at Taean in 2007. Also, to estimate the contribution of ions on its acidity, ion composition characteristics and neutralization effects by cation ions were determined. The ion balance between cations and anions values showed high correlation. The mean values of pH and EC were 4.9 and $32.9{\mu}S\;cm^{-1}$, respectively. The EC of rainwater showed seasonal characteristic, which was $91.4{\mu}S\;cm^{-1}$ with relatively low rainfall compared with other monitoring periods. $Na^+$ was the main cation followed by $NH_4{^+}$ > $Ca^{2+}$ > $H^{+}$ > $Mg^{2+}$ > $K^+$. Among these ions, $Na^{+}$ and $NH_4{^+}$ covered over 70% of total cations. In the case of anion, the order was $SO_4{^{2-}}$ > $NO_3{^-}$ > $Cl^{-}$. The mean value of sulfate, which is main anion component in the samples was $152.1{\mu}eq\;L^{-1}$. Also, 90% of soluble sulfate in rainwater was $nss-SO_4{^{2-}}$(non-sea salt sulfate). With fractional acidity and theoretical acidity of rainwater samples, $NH_4{^+}$ and $Ca^{2+}$ contributed greatly in neutralizing the rain acidity.