• Journal of the Korean Wood Science and Technology
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• v.19 no.2
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• pp.56-64
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• 1991

The destructed chips(Pinus rigida Mill) were sulfonated under different conditions and defiberated. The yields and strengths of pulp, fatty acid and resin acid in sulfonated chips were determined. The results of this work were as follows: 1) A sulfonation caused a yield reduction to 97.9~88.2% at single stage. and to 94.9~88.2% at two stage pretreatment. The pulp yields were rapidly draped with increasing cooking temperature from $130^{\circ}C$ to $150^{\circ}C$ 2) Pulp strengths were improved with iacreasing cooking temperature. A sulfonation with 5% $Na_2SO_3$/NaOH(8/2) at single stage and 2% NaOH-5% $Na_2SO_3$ at two stage were most effective and gave the best combination of strength properteis. 3) Fatty acid esters in chips were mostly consisted of palmitic and olleic acid. During a sulfonation the former increased extensively, and the latter was lost with increase of cooking times. The amount of pimaric type in the chips was relatively decreased by the pretreatnent and abietic-type increased. But the changes between two resin acid types were insignificant. 4) The effciency of pitch removal was dependant upon cooking liquor pH. To remove sufficiently the resinous substance, the chips must be sulfonated at over pH 12. Therefore, taking account of pitch removel, two stage sulfonation is considered suitable as reinforcement pulp for newsprint manufacture from pitch pine chips : 2% NaOH($60^{\circ}C$ 1 hr) at first stage and 5% $Na_2SO_3$ ($130^{\circ}C$, 1hr) at secund stage.

• The Korean Journal of Physiology and Pharmacology
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• v.7 no.6
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• pp.357-362
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• 2003

Carbon monoxide (CO) is low molecular weight oxide gas that is endogenously produced under physiological conditions and interacts with another gas, nitric oxide (NO), to act as a gastrointestinal messenger. The aim of this study was to determine the effects of exogenous CO on L-type calcium channel currents of human jejunal circular smooth muscle cells. Cells were voltage clamped with 10 mM barium ($Ba^{2+}$) as the charge carrier, and CO was directly applied into the bath to avoid perfusion induced effects on the recorded currents. 0.2% CO was increased barium current ($I_{Ba}$) by $15{\pm}2$% ($mean{\pm}S.E.$, p<0.01, n=11) in the cells. To determine if the effects of CO on barium current were mediated through the cGMP pathway, cells were pretreated with 1-H-[1,2,4]oxadiazolo[4,3,-a]quinoxalin-1-one (ODQ, $10{mu}M$), a soluble guanylyl cyclase inhibitor, and exogenous CO (0.2%) had no effect on barium currents in the presence of ODQ ($2{\pm}1$% increase, n=6, p>0.05). CO mediates inhibitory neurotransmission through the nitric oxide pathway. Therefore, to determine if the effects of CO on L-calcium channels were also mediated through NO, cells were incubated with $N^G-nitro-L-arginine$ (L-NNA, 1 mM), a nitric oxide synthase inhibitor. After L-NNA pretreatment, 0.2 % CO did not increase barium current ($4{\pm}2$% increase, n=6, p>0.05). NO donor, SNAP ($20{\mu}M$) increased barium current by $13{\pm}2$% (n=6, p<0.05) in human jejunal smooth muscle cells. These data suggest that CO activates L-type calcium channels through NO/cGMP dependant mechanism.

• Korean Journal of Veterinary Research
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• v.12 no.1
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• pp.37-50
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• 1972

Another comparison of alveolar gas pressures, in a continuously rebreathing dog lung, with pulmonary arterial (mixed venous) blood, again showed alveolar pressures to be the higher for $CO_2$ and usually $O_2$ (positive ${\Delta}Pco_2$, and ${\Delta}Po_2$). ${\Delta}Pco_2$ was almost invariably positive, it was independant of time and of plasma pH changes produced by acid or bicarbonate infusion, but proportional to blood $CO_2$ level. It was seemingly little affected by the distribution or magnitude of blood flow nor did it result from failure of $CO_2$ equilibrium within the blood, but it did rise with carbonic anhydrase inhibition. ${\Delta}Po_2$ was more variable and sometimes negative, particularly at low blood flow rates. It seemed in dependant of time, and plasma pH changes, apart from an inverse relationship with that resulting from $CO_2$ changes. It existed despite considerable potential for gas exchange, and was unaffected by inhibition of the $CO_2$ reactions.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.3
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• pp.334-339
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• 2007

Reactive oxygen species (ROS) generate during electrical activation of oocytes which has detrimental effects on embryo survival when overwhelmed. The present study was designed to investigate the ability of L-ascorbic acid, a novel water soluble antioxidant, to reduce the ROS level in developing embryos and their subsequent effects on embryo development in vitro. The compact cumulus oocyte complexes (COCs) were cultured in tissue culture medium (TCM)-199 supplemented with 10 ng/ml epidermal growth factor, 4 IU/ml pregnant mare serum gonadotropin (PMSG), and human chorionic gonadotropin (hCG) and 10% (v/v) porcine follicular fluid (pFF) for 44 h. After maturation culture, the denuded oocytes were activated with a single DC pulse of 2.0 kV/cm in 0.3 M mannitol solution containing 0.5 mM of HEPES, 0.1 mM of $CaCl_2$ and 0.1 mM of $MgCl_2$ for $30{\mu}s$ using a BTX Electro-cell Manipulator. The activated oocytes were cultured in modified North Carolina State University-23 (mNSCU-23) medium for 168 h. The level of $H_2O_2$ in each embryo was measured by the dichlorohydrofluorescein diacetate (DCHFDA) method at 48 h after activation. The blastocyst formation rate was significantly higher when culture medium was supplemented with 50 and $100{\mu}M$ L-ascorbic acid (31.2 and 38.7%, respectively) compared to non-supplemented (16.1%) group. Accordingly, significantly more cells in blastocyst were found for 50 and $100{\mu}M$ L-ascorbic acid (50.0 and 56.4, respectively) compared to 0 and $200{\mu}M$ L-ascorbic acid (36.5 and 39.8, respectively). L-ascorbic acid reduces the $H_2O_2$ level in developing embryos in a dose-dependant manner. The $H_2O_2$ level (pixels/ embryos) was 191.5, 141.0, 124.0 and 163.3 for 0, 50, 100 and $200{\mu}M$ L-ascorbic acid, respectively. So, we recommend to supplement 50 or $100{\mu}M$ L-ascorbic acid in porcine in vitro culture medium.

• Journal of Animal Science and Technology
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• v.45 no.4
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• pp.641-648
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• 2003

In a batch mode treatment process, which electrolyzes the wastewater after derivation of N-P crystal formation and recovery, the characteristics of pollutant removal induced with the changes of loading rate and hydraulic retention time were studied. $MgCl_2$ was used as Mg source for the formation of struvite and the molar ratio of $MgCl_2$ to $PO_4^{3-}$ in influent was 1.3. When analyzing the average treatment efficiencies and removal characteristics obtained from four separate operations (Run I, II, III, IV), removal efficiencies of PO43- was not function of its loading rate. Under a condition of sufficient aeration and Mg source provided, over 88% of $PO_4^{3-}$ was eliminated by the formation of MAP without any pH adjustment, in spite of loading rate variation. An optimum-loading rate of NH4-N to achieve high removal efficiency was approximately $100g/m^3/d$. Below that loading rate, the removal of NH4-N was proportional to the loading rate into the system, and hence stable and high removal efficiency, over 90%, was achieved. However, when the loading rate increased over that rate, removal efficiency began to drop and fluctuate. Removal efficiency of TOCs was dependant upon the hydraulic retention time ($r^2$=0.97), not upon the loading rate. Stable and high color removal (94%) was obtained with 2 days of HRT in electrolysis reactor.

• Applied Biological Chemistry
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• v.38 no.6
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• pp.570-576
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• 1995

The new sixteen herbicidal N-2-(1-hydroxy-2-fluoroethyl)-6-substituted(X)-benzenesulfonyl-N'-4,6-dimethoxypyrimidinyl-2-yl urea derivatives(S) were synthesized and thier herbicidal activities$(pI_{50})$ in vivo against rice(Orysa Sativa L.), Barnyard grass(Echninochloa orizicola) and Bulrush(Scirpus juncoides) were measured by the pot test under paddy conditions. The structure activity relationship(SAR) were studied using the physicochemical parameters of ortho-substituents(X) and hydrolysis rate constant(logk) and herbicidal activities by the multiple regression technique. The SAR suggested that the herbicidal activities were more dependant on the hydrolysis rate constant(logk>0) than the steric constants $(Es, small width($B_4$) and length($L_1$). Among them, halogens(2 & 5), methyl(15) and non(H) substituent(1) showed higher herbicidal activity for weeds which was not tolerent to rise and weeds. The herbicidal activity was increased and the persistency in aqueous solution was decreased by electron donating(${\sigma}0<0$) groups as ortho-substituent(X). From the relationship equation between herbicidal activity and hydrolysis rate constant, it was assumed that the both reactions would be proceeds with similar process. And the conditions on the ortho substituents to show higher herbicidal activity and the persistency in aqueous solution were also discussed.

• Korean Journal of Food Science and Technology
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• v.41 no.6
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• pp.694-699
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• 2009

The antimutagenic activities of ethanol extracts of Korean and American propolis were tested using Salmonella Typhimurium TA98 with two indirect mutagens of 3-amino-1,4-dimethyl-5H-pyrido [4,3-b]indole (Trp-P-1) and 2-aminoanthracene (2-AA) with S9 mix. Additionally, their antimicrobial activities against acne-related pathogenic strains of Propionibacterium acnes, Staphylococcus Epidermidis, Staphylococcus aureus and Pseudomonas aeruginosa were evaluated using both paper disk method and agar dilution method. Ethanol extracts of Korean and American propolis showed strong inhibitory effects, in a dose dependant manner, against the mutagenicities induced by Trp-P-1 and 2-AA. The antimutagenic effect of ethanol extracts of Korean propolis showed significantly higher protective activity than that of American propolis against the Trp-P-1 induced mutagenicity of S. Typhimurium TA98 at the lower concentration ($1-10\;{\mu}g$), but significantly lower protective activity at the higher concentration ($50-200\;{\mu}g$). The antimutagenic effect of ethanol extract of Korean propolis showed significantly higher protective activity than that of American propolis against the 2-AA induced mutagenicity at the concentration of $1\;{\mu}g$, but significantly lower protective activity than that of the American at the higher concentration ($50-200\;{\mu}g$). Both extracts showed strong antimicrobial activities against all the acne-related pathogens tested, with minimal inhibitory concentration (MIC) values in the range $1,500-5,000\;{\mu}g/mL$.

• Journal of Food Hygiene and Safety
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• v.22 no.1
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• pp.37-44
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• 2007

The approval of use of certain food-grade phosphates as food additives in a wide variety of meat products greatly stimulated research on the applications of phosphates in foods. Although phosphates have never been classified as antimicrobial agents, a number of investigators have reported that phosphates have antimicrobial activities. Phytic acid is a natural plant inositol hexaphosphate constituting 1-5% of most cereals, nuts, legumes, oil seeds, pollen, and spores. In this study, we investigated antibacterial activities of sodium phytate(SPT), sodium pyrophosphate (SPP), sodium tripolyphosphate (STPP) on Escherichia coli O157:H7 on tryptic soy broth and in beef, pork and chicken. In tryptic soy broth, SPT, SPP and STPP at the concentrations of 0.05, 0.1, and 0.5% effectively inhibited the growth of Escherichia coli O157:H7 in a concentration-dependent manner. The bactericidal activity of SPT was the stronger than that of SPP or STPP at the same concentrations. In addition, the antibacterial effects of SPT, SPP and STPP at the concentrations of 0.05, 0.1, 0.3, and 0.5% on Escherichia coli O157:H7 were also investigated in raw or cooked meats including beef, pork and chicken. SPT, SPP and STPP significantly inhibited the bacterial growth in a dose-dependant manner (p<0.05). The bactericidal effect of SPT was stronger than that of SPP or STPP. The addition of SPT, SPP and STPP in meats increased meat pHs. SPP and STPP also increased the levels of soluble orthophosphate in meats but STP did not. These results indicate that SPT is very effective for inhibition of bacterial growth and that can be used as a muscle food additive for increasing functions of meats.

• Journal of Food Hygiene and Safety
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• v.22 no.4
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• pp.382-387
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• 2007

The approval of use of certain food-grade phosphates as food additives in a wide variety of meat products greatly stimulated research on the applications of phosphates in foods. Phytic acid is a natural plant inositol hexaphosphate constituting 1-5% of most cereals, nuts, legumes, oil seeds, pollen, and spores. In this study, we investigated antibacterial activity of sodium phytate (SPT) against Salmonella typhimurium in tryptic soy broth with different pHs and in chicken, pork and beef. In tryptic soy broth, SPT at the concentrations of 0.1, 0.5, and 1.0% effectively inhibited the growth of Salmonella typhymurium in a concentration-dependent manner. At pH 5.5-7.0 similar to meat pHs, 1% SPT almost completely inhibited the bacterial growth. The inhibitory effect of SPT was stronger at pH 7.0 than pH 5.5. In chicken, pork, and beef, SPT at the concentrations of 0.1, 0.5, and 1% significantly inhibited the growth of Salmonella typhimurium in a dose-dependant manner (p<0.01). The addition of 1% SPT in the meats significantly increased the meat pHs. These results indicate that SPT is very effective for inhibition of bacterial growth as a muscle food additive for increasing food safety and functions.

• Journal of the Korean Applied Science and Technology
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• v.34 no.3
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• pp.451-460
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• 2017

This study optimized the extraction of antioxidants from Gugija (Lycium chinensis Mill). To determine operational parameters, including ethanol concentration ($X_1$, 0~80%) and extraction time ($X_2$, 1~5 hr), response surface methodology was applied to monitor yield, anthocyanins, flavonoids and DPPH radical scavenging activity. Coefficients of determinations ($R^2$) of the models were range of 0.8645~0.9859 (p<0.01~0.1) in dependant parameters. Yield of Gugija extracts was maximized 23.12% in extraction conditions of 4.22 h at 8.25% ethanol. Anthocyanins was maximized 1.43 (OD in 530 nm) in extraction conditions of 3.06 h at 79.98% ethanol. Flavonoids was maximized $3,100{\mu}g/100g$ in extraction conditions of 3.37 h at 67.02% ethanol. DPPH radical scavenging activity was maximized 96.93% in extraction conditions of 1.67 h at 69.81% ethanol. Optimum extraction conditions (2.5 h extraction at 70% ethanol) were obtained by superimposing the contour maps with regard to anthocyanins, flavonoids and DPPH radical scavenging activity of Gugija. Maximum values of anthocyanins, flavonoids and DPPH radical scavenging activity in optimum extraction condition were 1.0080 (OD in 530 nm), $3,145{\mu}g/100g$, 96.96%, respectively. But values of anthocyanins, flavonoids and DPPH radical scavenging activity in water extraction condition (1 h at water) were 0.4652 (OD in 530 nm), $1,633{\mu}g/100g$, 86.98%, respectively.