• Journal of Environmental Impact Assessment
• /
• v.6 no.1
• /
• pp.105-110
• /
• 1997

Sanitary landfill is a general method as a final disposal of municipal solid waste(MSW), therefore leachate characteristics are very various as lime goes by because of highly concentrated organic acids are contained non biodegradable COD. So it is hard to abide by the mandatory standards of discharge eventhough applying the physicochemical and biological processes to treat the leachate. The process of treating leachate are determined by the degree of removal and components, but they are highly contained organic materials. It is a removal method to use jointly with the physicochemical process if the hard and fast rule is needed. The critical components of material are COD, ammonia, salts and heavy metals in the case of treating biologically. Biological process is to use metabolism of microorganism, therefore it is a desirable condition which heavy metals are not contained, because they acting as an inhibitor of enzyme. Of these are contained, organic decomposition and synthetic function of microorganisms decrease significantly. Consequently, this research paper lays emphasis on the concentration of heavy metals in leachate and for the purpose of forecasting the factors which are affecting the leaching of metalic waste in some degree, experimented the various reacting conditions. 1. When the concentration of heavy metals in leachate is in comparison with the level eluted after reaction, at pH 7.9 the result of reaction for PCB to CCL scrap showed that Zn, Mn, Cu was more eluted 11.6 times, 340.3 times, and 2,705.5 times respectively than the leachate undiluted solution. 2. At the condition of strong acid pH 4.7, the concentration of heavy metals in EM undiluted solution showed that Zn, Mn, Cu was more eluted 26.5 times, 147.3 times, and 3,656.3 times respectively than leachate undiluted solution. 3. When the ratio leachate to EM was 50 vs 50(V/V%), Mn was more eluted 198.7 times than leachate undiluted solution, but Zn and Cu do not show the meaningful results. 4. The color of landfill leachate was black-brown. And fulvic acid that is main ingredient of NBD COD contained, oxygen of 44~50%. For that reason, I estimated that the level of Zn, Mn, Cu was higher than the case of leachate. 5. COD of leachate from general landfill is difficult to remove. Because the solution of heavy metals is improved by the character of leachate(pH & ingredient of oxygen etc.) hence the Mn, Cu, Zn act as disturbing factor, the biochemical treatment is hard. Therefore the type of PCB & CCL scrap, iron, aluminum contained metals need to previously separate from general wastes as much as possible.

• Journal of the Mineralogical Society of Korea
• /
• v.23 no.1
• /
• pp.51-61
• /
• 2010

Ettringite $(Ca_6[Al(OH)_6]_2(SO_4)_3{\cdot}26H_2O)$ is a sulfate mineral that shows a complicate property in concrete. It is often called as "a cancer of concrete" because secondary ettringite formation in hardened concrete often cause expansion and cracking of concrete due to its expansive crystal structure. In the present study, we tested the possibility for crystal growth inhibition of secondary ettringite by crystallization inhibitors that are commercially used for scaling inhibitors in Korea. For the test, we developed a method of ettringite solution synthesis. Three types of crystallization inhibitors were selected and examined the effects On ettringite growth inhibition. The experimental results of ettringite solution synthesis indicated that ettringite was successfully synthesized under condition that the mass balance between calcium hydroxide saturated solution and aluminum sulfate solution was attained. Monosulfate and semisulfate were synthesized when the ratio of $Ca^{2+}$ ions to ${SO_4}^{2+}$ ions was increased. The induction time of ettringite crystallization was less than 2 min. and crystallization was almost completed within an hour. The experimental results of ettringite crystallization inhibition showed that organic PBCT (2-Phosphonobutane-1,2,4-Tricarboxylic Acid) and inorganic SHMP (Sodium Hexametaphosphate) were relatively less effective on ettringite crystallization inhibition under experimental conditions. However, organic HEDP (1-Hydoxyethylidene-1,1-Diphosphonic Acid) effectively prevented ettringite growth with producing amorphous gel phase materials up to inhibitor concentration 0.1 vol.% of aluminum sulfate solution.

• Journal of Life Science
• /
• v.30 no.1
• /
• pp.96-105
• /
• 2020

Sirtuin inhibitors are pharmaceutically and therapeutically valuable compounds that inhibit sirtuin, a type III histone deacetylase. Synthetic sirtuin inhibitors were discovered and characterized using cell-based screens in yeast (Saccharomyces cerevisiae) and have been used in the study of aging, carcinogenesis, and diabetes, all of which are related to sirtuin function. For medical applications, synthetic inhibitors have been further developed for increased potency and specificity, including compounds containing nicotinamide, thioacetyl lysine, β-naphthol, and indole derivatives. Suramin, tenovin, and their analogues were developed as a result. Sirtuin inhibitors were found to affect organic development and have been used to genetically modify plants, although a sirtinol-resistant mutation in the biosynthesis of a molybdopterin cofactor for an aldehyde oxidase has been identified. Some natural flavonoids, and catechin and quercetin derivatives also act as sirtuin inhibitors have been studied to identify a more potent inhibitor for therapeutic purposes. In this review, sirtuin is introduced and the therapeutic inhibitors that have been developed are presented, particularly sirtinol which has been used for genetic modification in plants though it was not designed to be so. Sirtuin inhibitors with greater potency and selectivity are required and those developed in pharmaceutics should be used in plant research to identify more authentic sirtuins in plants.

• Clinical and Experimental Reproductive Medicine
• /
• v.19 no.2
• /
• pp.105-116
• /
• 1992

The present study was examined to clarify the role of calcium ion as a factor for the maturation of mouse oocytes. Follicles and cumulus-enclosed oocytes were isolated with two sharp needles under a stereomicroscope from female mouse (ICR) ovaries which were treated PMSG 5 IU 45-46 hours previously. Isolated follicles and cumulus-enclosed oocytes were cultured for 14-16 hours in an organ culture system at $37^{\circ}C$, 5% $CO_2$ in air and 100% humudified in incubator. MHBS was the basic medium used from which A23187, verapamil, $NiCl_{2.}$ $6H_2O$ and $LaCl_{3.}$ $7H_2O$ were added depending on the experimental groups. In follicle- or cumulus-enclosed oocytes wre cultured in these differently treated media. Following results were obtained from the present study. 1. The calcium ionophore A23187 directly or indirectly seems to stimulate GVBD of follicle-enclosed mouse oocytes. Increasing concentration of ionophore A23187 1ed to an increase in oocytes degeneration from the cumulus-enclosed mouse oocytes. 2. The organic $Ca^{++}$ channel blocker, verapamil does not induce GVBD of follicle-enclosed mouse oocytes. Specially, higher dose of 1 mM verapamil induced GVBD of follicle-enclosed mouse oocytes. However, cytoplasm of GVBD oocytes in 1 mM verapamil treated groups appeared shrunk. In the cumulus-enclosed oocytes, polar body formation was reduced in verapamil treated groups and degeneration increased. Verapamil inhibit oocyte maturation (polar body formation). 3. The $Ca^{++}$ inhibitor, Nickel ($NiCl_{2.}$ $6H_2O$) inhibits maturation of the follicle-enclosed oocytes. In the cumulus-enclosed oocytes the progression to MII (PB formation) was reduced and degeneration of mouse oocytes increased as the concentration of $Ni^{++}$ increase. The results indicates that nickel act as an inhibitor of calcium. 4. The $Ca^{++}$ inhibitors, Lanthanum ($LaCl_{3.}$ $7H_2O$) has shown different effect from that of nickel. In follicle-enclosed oocytes, 0.01mM lanthanum induced maturation of mouse oocytes. Polar body formation was reduced in the cumulus-enclosed oocytes all lanthanum treated group.

• Journal of the Korean Applied Science and Technology
• /
• v.32 no.1
• /
• pp.56-61
• /
• 2015

In this study, the current-voltage curves for the SCM440 steel by the addition of an organic corrosion inhibitor triethanolamine(TEA) was measured using the conventional three electrodes of cyclic voltammetry. As a result, the C-V characteristics of SCM440 steel were to be for an irreversible process due to the oxidation current from the cyclic voltammetry. Diffusion coefficient according to the twice increasing the concentration of TEA in the corrosion inhibitor from $2.5{\times}10^{-4}M$ to $5.0{\times}10^{-4}M$, the diffusion coefficient was found to be a good corrosion-inhibiting effect is reduced by 1.5 times, so for each $2.561{\times}10^{-6}cm^2s^{-1}$ to $1.707{\times}10^{-6}cm^2s^{-1}$. When according to the electrolyte concentration and the effect is to increase the electrolyte concentration to 1.0 N at 0.5 N, the diffusion coefficient is $2.56{\times}10^{-6}cm^2s^{-1}$ to $5.12{\times}10^{-6}cm^2s^{-1}$, each 2 times decrease in the use of the electrolyte of 1.0 N, because this was more appropriate.

• Korean Journal of Food Science and Technology
• /
• v.26 no.4
• /
• pp.464-470
• /
• 1994

The biological activities of Humulus japonicus were extracted by water and methanol. Methanol was better solvent than water in the extraction for antimicrobial activities against six different species of bacteria and two yeasts. The methanol extract was systematically fractionated with various organic solvents which have different polarities. From the result of antimicrobial activities against six species of bacteria and two species of yeasts, methanol extract was superior to water extract. The methanol extract of Humulus japonicus showed antimicrobial activity against the all species of microorganisms tested except Escherichia coli . The butanol fraction of methanol extract showed antimicrobial effect on the all species tested. The minimal inhibition concentration(MIC) of the butanol fraction on the growth of microorganisms was ranged between $0.1{\sim}0.4%$. The water extract of Humulus japonicus did not show inhibition of the activity of trypsin but methanol extract showed inhibitory activity. The chloroform fraction of methanol extract showed comparatively higher trypsin inhibitory activity than other fractions. The concentration of 50% inhibition$(IC_{50})$ by chloroform fraction was 1.0 mg/ml. Enzyme-inhibitor complex formation was above 90% of the while for 20 min. It was revealed that methanol extract of Humulus japonicus inhibited peroxide production of lard and soybean oil as substrate by antioxidative test. The chloroform fraction of methanol extract had the highest activity. When 0.2% of chloroform fraction was added, induction period of soybean oil and lard were extended 15, 9 days, respectively.

• Journal of Environmental Science International
• /
• v.31 no.8
• /
• pp.677-689
• /
• 2022

In order to photocatalytically treat organic matter (COD_Cr) and chromaticity effectively, chemical coagulation and sedimentation processes were employed as a pretreatment of the leachate produced from landfill in Jeju Island. This was performed using FeCl₃·6H₂O as a coagulant. For the treated leachate, UV/TiO₂ and UV/TiO₂/H₂O₂ systems were investigated, using 4 types of UV lamps, including an ozone lamp (24 W), TiO₂ as a photocatalyst, and/or H₂O₂ as an initiator or inhibitor for photocatalytic degradation. In the chemical coagulation and sedimentation process using FeCl₃·6H₂O, optimum removal was achieved with an initial pH of 6, and a coagulant dosage of 2.0 g/L, culminating in the removal of 40% COD_Cr and 81% chromaticity. For the UV/TiO₂ system utilizing an ozone lamp and 3 g/L of TiO₂, the optimum condition was obtained at pH 5. However, the treated COD_Cr and chromaticity did not meet the emission standards (COD_Cr: 400 mg/L, chromaticity: 200 degrees) in a clean area. However, for a UV/TiO₂/H₂O₂ system using 1.54 g/L of H₂O₂ in addition to the above optimum UV/TiO₂ system, the results were 395 mg/L and 160 degrees, respectively, which were within the emission standard limits. The effect of the UV lamp on the removal of COD_Cr, and chromaticity of the leachate decreased in the order of ozone (24 W) lamp > 254 nm (24 W) lamp > ozone (14 W) lamp > 254 nm (14 W) lamp. Only COD_Cr and chromaticity treated with the ozone (24 W) lamp met the emission standards.

• Biomedical Science Letters
• /
• v.23 no.1
• /
• pp.8-16
• /
• 2017

p-Coumaric acid is an organic compound that is a hydroxyl derivative of cinnamic acid. Due to its multiple biological activities p-coumaric acid has been widely studied in biochemical and cellular systems and is also considered as a useful therapeutic candidate for various neuronal diseases. However, the efficacy of p-coumaric acid on zebrafish developmental regulation has not been fully explored. In this study, therefore, we first investigated the action mechanism of the p-coumaric acid on the zebrafish development in a whole-organism model. p-Coumaric acid treated group significantly inhibited the pigmentation of the developing zebrafish embryos compared with control embryos without any severe side effects. In addition, p-coumaric acid down-regulated more effectively in a lower concentration than the well-known zebrafish's melanogenic inhibitor, phenylthiourea. We also compared the molecular docking property of p-coumaric acid with phenylthiourea on the tyrosinase's kojic acid binding site, which is the key enzyme of zebrafish embryo pigmentation. Interestingly, p-coumaric acid interacted with higher numbers of the amino acid residues and exhibited a tight binding affinity to the enzyme than phenylthiourea. Taken all together, these results strongly suggest that p-coumaric acid inhibits the activity of tyrosinase, consequently down-regulating zebrafish embryo pigmentation, and might play an important role in the reduction of dermal pigmentation. Thus, p-coumaric acid can be an effective and non-toxic ingredient for anti-melanogenesis functional materials.

• Journal of Pharmaceutical Investigation
• /
• v.41 no.4
• /
• pp.239-247
• /
• 2011

Simvastatin is an inhibitor of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, which catalyzes the conversion of HMG-CoA to mevalonate, an early and rate-limiting step in the biosynthesis of cholesterol. Simvastatin has good permeability, but it also has low solubility (BCS class II), which reduces its bioavailability. To overcome this problem, a solid dispersion is formed using a spray-dryer with polymeric material carrier to potentially enhance the dissolution rate and extend drug absorption. As carriers for solid dispersion, Gelucire$^{(R)}$44/14 and Gelucire$^{(R)}$ 50/13 are semisolid excipients that greatly improve the bioavailability of poorly-soluble drugs. To avoid any toxic effects of an organic solvent, we used aqueous medium to melt Tween$^{(R)}$ 80 and distilled water. The structural behaviors of the raw materials and the solid dispersion were analyzed by differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM). The DSC and PXRD data indicated that the crystalline structure of simvastatin was transformed to an amorphous structure through solid dispersion. Then, solid dispersion-based tablets containing 20 mg simvastatin were prepared with excipients. Dissolution tests were performed in distilled water and artificial intestinal fluid using the USP paddle II method. Compared with that of the commercial tablet (Zocor$^{(R)}$ 20 mg), the release of simvastatin from solid dispersion based-tablet was more efficient. Although the stability study is not complete, this solid dispersion system is expected to deliver poorly water-soluble drugs with enhanced bioavailability and less toxicity.

• The Korean Journal of Physiology
• /
• v.16 no.2
• /
• pp.177-186
• /
• 1982

The effect of ethacrynic acid (EA) on the renal secretion of PAH was examined in cat kidney. $C_{PAH}$ and $T_{PAH}$ were measured before and after infusion of EA $(0.5{\sim}50mg/kg)$ through the femoral vein. The following results were obtained: 1) In the dosage range of 0.5 to 25 mg/kg, EA increased the urine flow, and sodium and potassium excretion in dose-dependent manner, but the glomelular filtration rate was decreased as the dosage of EA was increased. 2) $C_{PAH}$ and $T_{PAH}$ were decreased by EA in the dosage range of 3 to 25 mg/kg and 1 to 50 mg/kg, respectively, in dose·dependent manner with the dosage to cause 50% inhibition of about 5 mg/kg. 3) With dosage of 0.5mg/kg, EA appeared to exert a great effect on diuretic response without the influence on $T_{PAH}$. At 10min after infusion of EA, a potent diuretic effect appeared, while $T_{PAH}$ did not show a significant change. These results suggest that the action mechanism of EA on tubular secretion of PAH may be different from that on natriuresis. 4) With dosage of 5 mg/kg, EA did not inhibit the Na-K-ATPase activity in microsomal fractions from both cortex and medulla. 5) The double reciprocal plot ($l/T_{PAH}$ versus $l/P_{PAH}$) suggested that EA inhibited the P AH secretion by a competitive pattern. However, probenecid, a prototypic inhibitor of the organic acid pump, had no influence on both the inhibitory effect of $T_{PAH}$ and the natriuretic effect by EA. These results suggest that in vivo EA altered tubular secretion of P AH through interactions with receptors that are not identical with the Na-K-ATPase.