• Journal of the Korea Concrete Institute
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• v.18 no.3 s.93
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• pp.371-378
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• 2006

Recently sewage facilities mainly consisted of concrete structures are being deteriorated seriously by biodeterioration originated from sulfur-oxidizing bacteria. In this study, to prevent biochemical corrosion of the sewer concrete, antibiotics which prevent growth of sulfur-oxidizing bacteria were developed and antimicrobial performance of it was investigated. After that, to consider applicability of antibiotics to concrete, physical properties of concrete covered with antibiotics were investigated. As a results of the study, it was proved that the antimicrobial performance of antibiotics was available. Also compressive strength and bond strength of concrete didn't closely connected with antibiotics, and resistance to abrasion, water absorption, air permeability, carbonation, salt damage and chemical attack of concrete was improved remarkably by covering with it.

• Archives of Pharmacal Research
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• v.14 no.3
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• pp.242-248
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• 1991

Antihypertensive effect of YH 334 was examined in various experimental hypertension rat models and the systemic and regional hymohynamic profiles of the compound were investigated in conscious spontaneously hypertensive rats (SHR). The antiypertensive potensive potency of YH 334 is found to be more than 10 times stronger than that of nitrendipine in the all hypertensive models. The effective doses to lower the initial blood pressure by 20% $(ED_{20})$ of YH334 were 1.4 mg/kg in normotensive rats (NR), 0.7 mglkg in SHR. 0.1 mg/kg in DOCA salt hypertensive rats (DHR) and 0.4 mg/kg in renal hypertensive rats (RHR), and the $ED_{20}$ values of nitrendipine were 15.8 mg/kg in NR, 7.1 mg/kg in SHR, 1.7 mg/kg in DHR and 4.8 mg/kg in RHR. The primary hemodynamic effect hemodynamic profile is similar to that of nitrendipine. Both compounds seem to produce potent antihypertensive effects by lowering peripheral resistance in the skeletal muscles. In the organ bath study using isolated rabbit aorta, YH 334 was found to be a potent voltage dependent calcium channel blocker without significant inhibitory effect on the receptor operated calcium channels like the most of other dihydropyridine type calcium antagonists. Furthermore, YH334 showed acute diuretic and natriuretic effects in conscious SHR, which may render the unnecessary restriction of sodium in the diet of those patients on long term hypertension therapy. This effect would provide an additional benefit to its potent antihypertensive activity.

• Food Science and Preservation
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• v.12 no.2
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• pp.184-189
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• 2005

In order to select probiotics having both a high survival rate and an ability to inhibit virulent pathogens, we have screened lactic acid bacteria and yeasts from Jeot-gal to examine their resistance to artificial gastric and bile juice. After being introduced in the artificial gastric acid for 2 hr, the isolated lactic acid bacteria and yeast were incubated for 24 hrs in the artificial bile juice. In particular, the strain ML 36, ML 128, and ML 178 survived the longest during 2 hr incubation period in the artificial gastric acid. All 3 strains of lactic acid bacteria, and 2 strains of yeast demonstrated higher growth rates than control in the artificial bile. In addition, the antimicrobial activity of lactic acid bacteria and yeasts was investigated to determine their efficiency as probiotic organisms. The lactic acid bacteria inhibited Gram positive and negative bacteria, while the yeast was marginally inhibited.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.37-37
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• 2017

Mechanistic studies of halophytes are urgent areas of agricultural research due to the increase in saline-contaminated and irrigated land worldwide. The halophyte Suaeda glauca (S. glauca) has advantages in terms of biomass and saline elimination due to its large mass and well-developed phenotype on seashores, although its mechanistic features and growing specificities still require systematic investigation. In this study, S. glauca was cultivated under various saline concentrations (0-400 mM) in Hoagland's solution in the absence or presence of indole derivatives to elucidate physiological features. The results confirmed the optimal growth and development of S. glauca in 50 mM NaCl, and morphologies such as the number of branches, shoot length, and fresh and dry weights were improved by indole-3-carboxylic acid (ICA) treatment. The cation concentrations in roots, shoots and leaves were investigated to examine the ionic imbalances in response to saline treatment, and the results demonstrated that sodium ions accumulated to high concentrations in leaves. The levels of calcium and potassium ions in roots were maintained or slightly decreased in the presence of 50 mM NaCl and proline concentration was increased significantly in roots at optimal concentrations. These results demonstrate that the concentrations of ions and metabolites are key regulators of optimal growth by regulating the physiology of halophytes.

• Korean Journal of Microbiology
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• v.45 no.2
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• pp.177-184
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• 2009

Three hundred lactic acid bacteria isolated from human feces were studied their probiotic characters to develop potential probiotics. The properties were tested on the basis of guideline for probiotic selection protocol such as tolerance for acid or bile salt, thermal stability, antimicrobial, anticancer cell, and antiviral activity. Strain Miny-148 was selected as a potential probiotic bacterium which showed resistance to low pH, bile salts and thermal stability. On the basis of fatty acid profiles and 16S rDNA sequences analysis, the strain was identified as Lactobacillus pentosus (similarity 99.9%). The strain, L. pentosus Miny-148, showed broad antimicrobial spectrum against E. coli O157:H7, Shigella flexneri, Bacillus anthracis, Staphylococcus aureus, E. coli, Vibrio cholerae, V. vulnificus, Salmonella typhimurium, and Methicillin-resistant S. aureus (MRSA). Cell-free culture supernatant of the strain also inhibited against the growth of HT-29 colon cancer cell and transmissible gastroenterits virus.

• Korean Journal of Microbiology
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• v.45 no.1
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• pp.10-16
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• 2009

A diverse range of stresses such as heat, cold, salt, ethanol, oxygen starvation or nutrient starvation induces same stress-responsive proteins. This general stress response enhances bacterial survival significantly. In Bacillus subtilis and closely related Gram-positive bacteria Listeria monocytogenes, the general stress response is controlled by the alternative transcription factor ${\sigma}^B$. The activity of ${\sigma}^B$ is regulated post-translationally by a signal transduction network that has been extensively studied in B. subtilis, and serve as a model for L. monocytogenes. The proposed model of L. monocytogenes signal transduction network is similar to that of B. subtilis, but the energy stress pathway is missing. More than 150 general stress proteins belong to ${\sigma}^B$ regulon of B. subtilis and L. monocytogenes. In both bacteria, ${\sigma}^B$ function is primarily important for resistance to diverse stresses. In addition, ${\sigma}^B$ function contributes to the control of important virulence genes in food-borne pathogen L. monocytogenes. Therefore, understanding of the general stress response is important not only for bacterial physiology, but also for pathogenicity.

• Applied Chemistry for Engineering
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• v.10 no.3
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• pp.461-466
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• 1999

The humidity sensor containing ammonium salt was prepared from the copolymer of 2-methacryloxyethyl dimethyl 2-hydroxyethyl ammonium bromide (MDHAB)/MMA/DAEMA = 6/3/1. The humid membrane was fabricated on the gold/alumina electrode by dipping. The impedances were $298k{\Omega},\;11k{\Omega}$, and $2.3k{\Omega}$ at 40%RH, 70%RH and 90%RH, respectively, at $5^{\circ}C$ and the humidity-sensitive characteristics were suitable for low temperature humidity sensor. The temperature-dependent coefficient between $5^{\circ}C$ and $20^{\circ}C$ was found to be $-0.80%RH/^{\circ}C$ and the hysteresis falled in the ${\pm}2%RH$ range. The response time was found to be 38 sec for the relative humidity ranging from 34%RH to 88%RH at $20^{\circ}C$. The reliabilities such as temperature cycle, humidity cycle, high temperature and humidity resistance, electrical load stability, stability of long-term storage and water durability were measured and evaluated for the application as a humidity sensor.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.4
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• pp.479-488
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• 2011

Nanofiltration was performed with polyaluminium chloride solutions at different pH conditions to understand effects of inorganic compounds on aluminum hydrolysis products, i.e., three distinctive groups of aluminum species: polymeric Al at low pH; $Al(OH)_3$ at neutral pH; and ${Al(OH)_4}^-$ at high pH. The PACl solution was prepared to be approximately 4.0mM and adjusted to the designated pH. The influence of inorganic compounds on Al species fouling was investigated with 4.9mM $CaCl_2$ and 3.5mM $MgSO_4$ because $Ca^{2+}$, $Mg^{2+}$, $Cl^-$, ${SO_4}^{2-}$ are the most common inorganics in the drinking water. NF membrane fouling was measured by flux decline rate. The impact of $CaCl_2$ was not significant on the individual Al hydrolysis products fouling. However, the flux decline rate was drastically changed in the presence of $MgSO_4$. The concentration of particulate matters was considerably increased possibly due to interaction between Al species and ${SO_4}^{2-}$ where $MgSO_4$ was introduced. The particulates were accumulated on the membrane and enhanced the hydraulic resistance of the cake layer. In addition, conductivity removal of the membrane was decreased when Al-hydroxide was dominant due to reduction of membrane surface charge. The rejection of $Ca^{2+}$and $Mg^{2+}$ were considerably different, which implys that composition of inorganics paly a role on conductivity removal.

• Applied Chemistry for Engineering
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• v.4 no.1
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• pp.54-63
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• 1993

Some emulsified 1, 2-disubstituted imidazolinium salts were synthesized by quaternization of 1, 2-disubstituted imidazoline which had been prepared by the reaction of dodecanoic acid with tetraethylenepentamine. 2-Docosamido-2'-docosanoyloxydiethylamine was prepared by the reaction of docosanoic acid with hydroxylethylethylenediamine. Then, some emulsified fatty carbamide salts were also synthesized by quaternization of fatty carbamide which had been prepared by the reaction of urea with the 2-docosamido-2'-docosanoyloxydiethylamine. Some softners were prepared by blending of these salts mentioned above. These softners were treated on acrylic fiber, then several properties were measured. As the results, softening and lubricating properties are good and a little antistatic property was observed. The synthesized softners were also proved as a durable softner by means of the several experiments : bending resistance test and measurements of feeling change with washing according to the pH changes. The surface structure of acrylic fibers treated with the softner were characterized by SEM.

• Journal of the Korean Ceramic Society
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• v.42 no.12 s.283
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• pp.827-832
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• 2005

In this study, thin electrolyte layer was prepared by 8YSZ ($8mol\%$ Yttria-Stabilized Zirconia) slurry dip and sol coating onto the porous anode support in order to reduce ohmic resistance. 8YSZ polymeric sol was prepared from inorganic salt of nitrate and XRF results of xerogel powder exhibited similar results $(99.2\pm1wt\%)$ compared with standard sample (TZ-8YS, Tosoh Co.). The dense and thin YSZ film with $1{\mu}m$ thickness was synthesized by coating of 0.7M YSZ sol followed by heat-treatment at $600^{\circ}C$ for 1 h. Thin film electrolyte sintered at $1400^{\circ}C$ showed no gas leakage at the differential pressure condition of 3 atm.