• Archives of Pharmacal Research
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• v.17 no.2
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• pp.76-79
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• 1994

The concentration of styrne in blood of the occupationally syrene-exposed workers was checked by gas chromatographic headspace analysis. Mandelic acd in urine, that is a major metabolite of styrene, and hippuric acid wre also analyzed by high performance liquid chromatography. For the biological monitoring of styrene-exposed workers, the routine method of the quantitative determination of styrene nad its metabolites in the biolgical samples were studied.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.2
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• pp.203-208
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• 2005

The aim of this experiment was to determine the chemical composition of six commonly utilized fodder trees and shrub species in Turkey, namely Glycrrhiza glabra L, Arbutus andrachne, Carpinus betilus, Juniperus communis, Quercus libari L and Pistica lentiscus and its relationship with gas production and estimated parameters when incubated with rumen fluid in vitro. There were significant (p<0.001) differences between leaves in terms of crude protein (CP), acid detergent fiber (ADF), total condensed tannin (TCT), bound condensed tannin (BCT) and soluble condensed tannin (SCT). Crude protein contents ranged from 5.74% (Juniperus communis) to 12.59% (Glycrrhiza glabra L). Acid detergent fiber contents ranged from 25.14% (Glycrrhiza glabra L) to 39.23% (Juniperus communis). Total condensed tannin (TCT) contents of leaves ranged from 4.34% (Quercus libari L) to 20.34% (Juniperus communis). Acid detergent fiber (ADF) and total condensed tannin contents of leaves were negatively correlated with gas productions and some estimated parameters. Potential gas productions (A) of Glycrrhiza glabra L, Arbutus andrachne, Quercus libari L and Pistica lentiscus were significantly (p<0.001) higher than those of Carpinus betilus and Juniperus communis whereas gas production rate (${\mu}_{24}$) of Pistica lentiscus was significantly (p<0.001) higher than the others. Time (h) to produce 50% of total gas pool size ($T_{50}$) of Juniperus communis was significantly (p<0.001) lower than that of Carpinus betilus whereas time (h) to produce 90% of total gas pool size ($T_{90}$) of Juniperus communis was significantly lower than the others except for Pistica lentiscus. The metabolizable energy (ME) contents of leaves ranged from 8.86 to 10.39 MJ $kg^{-1}$ DM. The results obtained in this study suggested that browse species had a significant effect on chemical composition, gas production and estimated parameters of leaves. Leaves from Glycrrhiza glabra L with a considerable amount of CP had a high rank value in terms of ME. Therefore leaves from Glycrrhiza glabra L may have a high potential value for small ruminant animals in terms of rumen and whole digestibility. Leaves from other species studied require protein supplementation when they are the only feed consumed by ruminant animals.

• Applied Biological Chemistry
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• v.28 no.4
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• pp.226-232
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• 1985

Changes in lipid and fatty acid composition in Korean native Meju were investigated at one week interval over 6 weeks of fermentation. For the systematically, salicic acid column chromatography and gas liquid chromatography were used. Following results were obtained. 1. The lipid fraction obtained from the soared soybean and the cooked soybean were mainly composed of $72.47%{\sim}92.35%$ of neutral lipid, phospholipid and glycolipid were 4.64% and 4.88%, respectively. During fermentation period, lipid content decreased to 80.59%, but glycolipid and phospholipid contents increased. 2. The triglyceride contents of nonpolar lipids prepared from the cooked soybean and the soaked sobean was 89.66% and 87.83% respectively. Free fatty acid, diglyceride and sterol contents increased during fermentation, whereas triglyceride content decreased. 3. Lipids extracted from the soaked soybean and the cooked soybean were composed of 54.58% linoleic acid, $22{\sim}20%$ oleic acid, $10{\sim}12%$ palmitic acid and $3{\sim}5%$ stearic acid. 4. During the Korean native Meju fermentation in palmitic acid decreased from the second week and stearic acid through $3rd{\sim}4th$ week. Oleic acid and linoleic acid content decreased gradually, but linolenic acid content increased. 5. During the fermentation, myristic acid content of glycolipid fraction increased. Lipase activity reached to the maximum at the 3rd week.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.2
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• pp.245-253
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• 2020

Objective: To develop the fermentation quality and chemical composition of alfalfa (Medicago sativa Lam.) silage, plants were inoculated with different lactic acid bacteria (LAB) strains at field 24 hours before harvest. Methods: The treatment groups were as follow: silage without additive as a control and inoculated with each strains of Lactobacillus brevis (LS-55-2-2), Leuconostoc citerum (L. citerum; L-70-6-1), Lactobacillus bifermentans (L. bifermentans; LS-65-2-1), Lactobacillus plantarum (L. plantarum; LS-3-3) and L. plantarum (LS-72-2). All the silages were stored at 25℃. Parameters such as pH, microorganism and volatile fatty acid contents, crude protein, neutral detergent fiber, acid detergent fiber, net gas, metabolizable energy, organic matter digestibility, dry matter intake and relative feed value were measured to determine fermentation quality, chemical compositions and relative feed value of alfalfa silages. Results: Significant differences were found among the control and treated groups in terms of pH and microorganism contents at all opening times and crude protein, net gas, metabolizable energy and organic matter digestibility of final silage. The pH values ranged from 4.70 to 5.52 for all treatments and control silage had the highest value of overall treatments at T₇₅d silages. Volatile fatty acid of silages was not influenced significantly by inoculations. However, lactic acid content of L. bifermentans (LS-65-2-1) was higher than the other treatments. The highest metabolizable energy and organic matter digestibility were recorded from L. citerum (L-70-6-1) inoculation. In addition, no significant differences were found among treatments in terms of neutral detergent fiber, acid detergent fiber, dry matter intake and relative feed value. Conclusion: Among the treated LAB isolates, L. bifermentans came into prominence especially in terms of organic acid composition and quality characters of silages.

• Applied Biological Chemistry
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• v.29 no.4
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• pp.366-371
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• 1986

Fatty acid compositions of Panax ginseng leaves (6 year) grown under different light intensity in field and of the detached leaves exposed to high temperature (20 hours) were investigated by gas chromatography. Linoleic, linolenic, palmitic and palmitoleic acid were the major components(80%) of leaf lipid. The higher the growth light intensity, the lower the percentage of unsaturated acids or bonds, indicating metabolic adaptation to high temperature. Pattern similarity of fatty acid composition was little changed until 20% light but significantly different at 30%, suggesting 20% as limitation light intensity. The close similarity of fatty acid composition between the loaves grown under 30% light and the one at harvest rises uncertainty between adaptation to high temperature and senescence. Total fatty acid content decreased with the increase of light intensity. Short term high temperature $(25^{\circ}C\;or\;35^{\circ}C)$ increased total fatty acid content, unsaturated acid percentage and insignificant difference in pattern similarity of composition.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.3 no.2
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• pp.188-193
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• 1993

Toluene in air and blood and hippuric acid in urine were checked for the 41 female workers who are exposed to toluene and have normal liver function in shoe making factories in July, 1993. Toluene in air was sampled with charcoal by personal air sampler at least 4 times and analyzed by gas chromatography. At the end of shift, blood and spot urine were collected with a vacuum tube containing EDTA and a polyethylene bottle for detecting blood toluene and urine hippuric acid and analyzed by gas chromatography and high performance liquid chromatography. Means of air and blood toluene and urine hippuric acid concentrations were 34.35ppm, 0.360mg/L, and 1.78g/g creatinine, respectively. Toluene in air showed a good correlation with hippuric acid in urine(r=0.4503) and toluene in blood(r=0.4596). The hippuric acid in urine and toluene in blood corresponded 10 exposure of 100ppm toluene in air were 2.628g/g creatinine and 0.481mg/L. Blood toluene and urine hippuric acid expected ratio were not correlated to the obesity index and working duration, however increased with age.

• YAKHAK HOEJI
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• v.33 no.2
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• pp.129-139
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• 1989

New diamide chiral stationary phases of four systematically substituted optically active N-(N-benzoyl-L-amino acid)-anilide synthesized from L-valine, L-leucine, L-isoleucine, and L-phenylalanine were described. The behaviors of these diamides as optically active stationary phases for the separation of N-trifluoroacetyl-D,L-amino acids were examined with respect to separation factors(${\alpha}$) and thermodynamic properties of interaction. The separation of twelve N-trifluoroacetyl-D,L-amino acid isopropyl esters were improved by the order of N-(N-benzoyl-L-leucyl)-anilide>N-(N-benzoyl-L-isoleucyl)-anilide>N-(N-benzoyl-L-valyl)-anilide>N-(N-benzoyl-L-phenylalanyl)-anilide. Eight amino acid derivatives with non-polar R-group and threonine, serine, aspartic acid, and glutamic acid enantiomers were separated on N-(N-benzoyl-L-leucyl)-anilide as chiral stationary phase with good separation factor between 1.07-1.25. The separation factors decreased with respect to increasing column temperature. Possible working temperature of diamide phase was between $130-190^{\circ}C$ for N-(N-benzoyl-L-phenylalanyl)-anilide and $130-180^{\circ}C$ for other three diamide phases. The differential Gibb's free energy (${\Delta}{\Delta}G$) of enantiomers was in the range of -100--180 cal/mol for ten amino acids and -40--60 cal/mol for alanine and aspartic acid.

• Korean Journal of Food Science and Technology
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• v.51 no.1
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• pp.12-17
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• 2019

Dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) in fresh-cut salads available from the market were determined by gas chromatography-mass spectrometry (GC-MS). The target compounds in 3 g of acidified homogenates were extracted with 20 mL of methyl t-butyl ether (MTBE). The extract was concentrated to 1 mL and heated for 1 h at $55^{\circ}C$. The analytes were separated using a DB-1701 column and detected with a mass spectrometer. The method detection limit was approximately $6{\mu}g/kg$, and both analytical accuracy and precision were found to be satisfactory. The linearity of the calibration curves expressed as the coefficients of determination was >0.996. The analysis of seven samples using the established method showed that the four samples contained considerable amounts of analytes ($25.4-31.2{\mu}g/kg$ of DCAA and $18.8-46.1{\mu}g/kg$ of TCAA). These results raised a concern about the impact of fresh-cut salad consumption on human health.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.4
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• pp.288-295
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• 2013

Nitrogen dioxide ($NO_2$) gas damage on vegetable crops commonly occurs in plastic film houses where relatively large amounts of $NO_3{^-}$ are applied in acid soils. In acid soils, $HNO_2$ can be formed from the $NO_2{^-}$ accumulated during denitrification, and $NO_2$ can be evolved from the chemical self-decomposition of $HNO_2$. In this study, $NO_2$ gas production and its detrimental effects on plants were investigated in soils of various conditions to elucidate the mechanisms involved in the gas production. A silty loam soil was amended with $NO_3{^-}$ (500 mg N $kg^{-1}$) and glucose, and pH and moisture of the soil were adjusted respectively to 5.0 and 34.6% water holding capacity (WHC) with 0.01 M phosphate buffer. The soil was placed in a 0.5-L glass jar with strawberry leaf or $NO_2$ gas absorption badge in air space of the jar, and the jar was incubated at $30^{\circ}C$. After 4-5 days of incubation, dark burning was observed along the outside edge of strawberry leaf and $NO_2$ production was confirmed in the air space of jar. However, when the soil was sterilized, $NO_2$ emission was minimal and any visible damage was not found in strawberry leaf. In the soil where water or $NO_3{^-}$ content was reduced to 17.3% WHC or 250 mg N $kg^{-1}$, $NO_2$ production was greatly reduced and toxicity symptom was not found in strawberry leaf. Also in the soil where glucose was not amended, $NO_2$ production was significantly reduced. In soil with pH of 6.5, $NO_2$ was evolved to the level causing damage to strawberry leaf when the soil conditions were favorable for denitrification. However, compared to the soil of pH 5.0, the $NO_2$ production and its damage to plants were much less serious in pH 6.5. Therefore, the production of $NO_2$ damaging plants might be occurred in acid soils when the conditions are favorable for denitrification.

• Proceedings of the KIEE Conference
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• 1998.07d
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• pp.1503-1505
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• 1998

Stearic acid was deposited on surface of 9[MHz], AT-cut quartz crystal microbalance as gas sensing material using Langmuir-Blodgett(LB) technique. We measured gas response between deposited LB films and organic gas for various temperature($0{\sim}80^{\circ}C$). The resonant frequency changed due to absorbance of organic gas such as methanol and butanol gas at room temperature. However, the resonant frequency not responded to methanol gas at temperature above melting point of deposited LB films.