• Journal of the Korean Applied Science and Technology
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• v.39 no.5
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• pp.720-726
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• 2022

The behavior changes of the lipid bilayer, induced by the hydroxybutyric-acid incorporation, were investigated with respect to each phase of the layer using fluorescence intensity change. Spherical phospholipid bilayers, called vesicles, were prepared using an emulsion technique. Only in the aqueous inside of the vesicles was encapsulated 8-Aminonaphthalene-1,3,6-trisulfonic-acid-disodium-salt(ANTS). p-Xylene-bis-N-pyridinium-bromide(DPX) was included as a quencher only outside of the vesicles. The fluorescence scale was calibrated with the ANTS-encapsulated vesicles in DPX-dispersed-buffer taken as 100% and the mixture of ANTS and DPX in the buffer as 0%. Hydroxybutyric-acid addition into the vesicle solution led the change in the bilayer. The change was found to be related to the phase of each layer according to the ratio of hydroxybutyric-acid to lipid. These results seem to depend on the stability of the vesicles, due to the osmotic and volumetric effects on the arrangement in both head-group and tail-group.

• Journal of fish pathology
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• v.5 no.2
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• pp.93-118
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• 1992

The research was carried out to examine the chronic toxic effects of nitrite on the Japanese eel, Anguilla japonica by neans of histological observations. Young eel, 10.8g mean body weight. were exposed to 6 different concentrations of nitrite(1, 5, 10, 20, 30 and 40ppm) for 10 weeks. Each concentration was treated under 5 different levels of pH(5.5, 6.0, 6.5, 7.0 and 7.5) and each of these treatment was tested at 2 different temperature regimes($25^{\circ}C$ and $30^{\circ}C$). Proper concentration of nitrite was made by $NaNO_2$ and proper pH levels were made by the combinations of 0.1M $KH_2PO_4$ and 0.1M $NaHCO_3$. Histopathological test of gill tissues were made along with the test of the formation of thrombocystes and chloride cells on the gill filaments. At the lower pH levels, mucus secretion from the gill was incrased as the nitrite concentration increased. As the level of nitrite increased the number of chloride cells on the gill filament were decreased. Most of the remained chloride cells were observed only at the terminar part of the gill filament at 40ppm of nitrite. Degeneration of gill tissues were observed when nitrite levels were over 10ppm along with detachement and sweption of the epithelial cells of the gill lamellae. Shrunken gill lamellae and formation of thrombosis in the capillaries of gill lamellae were also observed. When temperature goes higher at the higher level of nitrite, necroses in the gill lamellae was increased. At the lower than 10ppm of nitrite, degeneration of gill lamellae was occured at the beginning of the test period but regenerated later. Negative effects of nitrite on the growth of young eel was started between 5~10ppm at the pH level of 7.0 and 7.5. Thrombosis formation were also started at this level. The safety concentration of nitrite at the pH levels of 7.0 and 7.5 on the small eel seems to be 1ppm. Thrombosis and gill lamella detachment and necrosis in the gill capillaries were not observed at this level. Chloride cells were appeared the whole part of the gill filament.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.1
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• pp.19-26
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• 1993

In this study rats in fasting or fed protein free restricted diet including only fat showed much lowered level of serum cholesterol and triglyceride accompanied by utmost weight loss and high level of blood urea nitrogen indicated the tissue degradation, especially in liver with signs of damage or necrosis of hepatic parenchymal cell leading to elevated glutamic pyruvate transaminase value and to death. Rats fed only perilla oil in starvation or as fat source in normal diet dropped down the level of serum cholesterol and triglyceride compared to beef tallow fed rat. But with evidence of glutamic pyruvate transaminase values which was significantly elevated long term ingestion of perilla oil is likely to cause the lesion or any damage of hepatic function.

• Journal of Korean Society of Forest Science
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• v.82 no.4
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• pp.337-346
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• 1993

Experiments were performed to find out the effects of simulated acid rain(SAR) of pH 4.0 or pH 2.5 for 12 weeks on stomatal resistance, wettability and anatomical changes in Quercus acutissima and Ginkgo biloba seedlings. As a control, distilled water with a pH 6.5 was also sprayed. Stomatal resistance of Q. acutissima and of G. biloba remarkably increased after exposure to SAR. SAR increased the wettability of Q. acutissima leaves measured with water blue solution and of G. biloba leaves measured by leaf contact angle method. Anatomical changes in the leaves of Q. acutissima affected by SAR were the partial damage of epidermis and parenchymatous cells. Scanning electron microscopical observation showed that the number of trichomes in the leaves of Q. acutissima treated with SAR markedly decreased and the erosion of epicuticular wax was significant. No distinct damage was found in the G. biloba leaves at pH 4.0, while epidermis and vascular tissue were collapsed at pH 2.5. No significant alteration of surface structures in this tree species was observed.

• Korean Journal of Food Science and Technology
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• v.23 no.5
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• pp.614-618
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• 1991

To investigate the efficacy of grapefruit seed extract (GFSE) in the preservation of Satsuma mandarin, the citrus fruits were treated with 0 (control, only wash), 100 ppm and 250 ppm, dried and stored for 8 weeks at $15{\sim}20^{\circ}C$ and 60% RH. While 80% of the control fruits were contaminated and decayed by Penicillium sp., forming the the greenish blue spores, 27% of 100 ppm GFSE-treated fruits were contaminated and decayed and only 13% of 250 ppm GFSE-treated fruits were contaminated and decayed and only 13% of 250 ppm GFSE-treated samples were contaminated and not decayed by the fungi. GFSE showed marded inhibitory action against Penicillium sp. which was related to the decay of the citrus fruits in vitro experiments. Fungal growth was completely controlled through use of 500 ppm and the recommended range of GFSE to preserve the citrus fruits was $250{\sim}500ppm$. Transmission electron microscopic examination showed the fungal conidiospores the function of which was destroyed by dipping into GFSE.

• The Korean Journal of Malacology
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• v.26 no.2
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• pp.157-163
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• 2010

This study was carried out to investigate the toxic effect of WSF (Water Soluble Fraction) on development time, development rate, attachment rate, survival rate and growth of the larvae during the early life stage of the abalone, Haliotis discus hannai. Also, observed effect of water temperature on the survival rate and histological change of gill in the early young shell. In the abalone, it takes around 12 hours in all experimental groups. Development and attachment rate of the abalone significantly lower more than 0.4 mg/L WSF compared to control group (P < 0.05). Survival rate of abalone larva and spot was significantly lower more than 0.4 mg/L and 2.4 mg/L WSF compared to control group, respectively (P < 0.05). Shell growth of the abalone were significantly lower more than 2.4 mg/L WSF compared control group (P < 0.05). Survival rate lower more than $25^{\circ}C$ exposure group compared water temperature $17^{\circ}C$ exposure group in the early young shell. The gill of abalone exposed water temperature $17^{\circ}C$ and $25^{\circ}C$ was showed atrophy of nucleus and breakdown of the filament, vacuolation of filament epithelial cell.

• Korean Journal of Food Science and Technology
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• v.28 no.1
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• pp.169-178
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• 1996

Target parameters such as water solubility index (WSI), intrinsic viscosity (IV), water holding capacity (WHC), oil holding capacity (OHC), soluble dietary fiber (SDF) and microstructure were investigated on three different screw configurations during twin-screw extrusion of wheat bran. WSI of raw wheat bran (RWB) was 13.7%, while that of extrudates ranged $16.3{\sim}23.2%$ when extruded using screw configurations with 5 reverse screw elements (RSE). It was found that the moisture content of RWB greatly affected WSI of extrudates. IV of wheat bran extrudates increased from 10.6 ml/g of RWB to $37.86{\sim}44.37\;ml/g$ of extrudates extruded using 3, 4 and 5 RSE, whose trend was highly related to the moisture content of RWB and the extrusion pressure. Multiplication of IV and soluble solid (SS) content exhibited good correlation $(R^2=0.85)$ with specific mechanical energy (SME). The results suggested that SS and molecular size are an important factor governed by the SME in solubilization of wheat bran. WHC increased with increasing feed rate and moisture content, while OHC decreased. SDF increased from 2.68% of RWB to $4.32{\sim}6.48%$ of extruded wheat bran, indicating the significant breakdown of cell wall components. Microstructure of the extrudates showed the distinct patterns of degradation and solubilization of cell wall structure, depending on the moisture content of RWB.

• Korean journal of food and cookery science
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• v.20 no.1
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• pp.86-94
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• 2004

The purpose of this study was to investigate the changes of hardness and microstructure of Dongchimi cooked with various source of water(distilled water, purified water, Cho Jung Carbonated Natural water). This study was conducted to observe the changes of pH, total acidity, salt content, turbidity, texture and microstructure. Dongchimi cooked with source of water of water was fermented at 10$^{\circ}C$ for 46 days. The changes of pH on Dongchimi cooked with various source of water decreased in all samples during fermentation period, and then showed a slowly decrease after 12 days of fermentation. The total acidity of Dongchimi cooked with Cho Jung Carbonated Natural water was arrived slowly at best tasting condition 0.3 ∼ 0.4 point compared with other conditions. So Dongchimi cooked with Cho Jung Carbonated Natural water was continued to the best tasting condition for end of fermentation. At early stage of fermentation, the changes of turbidity of Dongchimi used Cho Jung Carbonated Natural water showed highly as compared with other test condition for 12th days of fermentation. The maximum cutting force of chinese radish of Dongchimi showed the highest value among all at the 25th day of ripening and then decreased gradually. The maximum cutting force of chinese radish of Dongchimi used Cho Jung Carbonated Natural water was the highest compared with other conditions at 25th day of fermentation. The calcium content of Dongchimi juice used Cho Jung Carbonated Natural water was observed hish at the early stage of fermentation and showed the highest value at 25th day of ripening. The calcium content of chinese radish and Dongchimi juice of Dongchimi cooked with water purifier was lower than that of Dongchimi cooked with Cho Jung Carbonated Natural water, and was higher than that of Dongchimi cooked with Distilled water at the early stage of fermentation. The magnesium content in all samples increased gradually from the early stage of fermentation. The microstructure showed disintegration appearance of middle lamella and cell wall during fermentation period.

• Journal of Sericultural and Entomological Science
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• v.25 no.2
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• pp.1-31
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• 1984

Flacherie, as one of the most prevalent silkworm diseases, causes severe economic damage to sericultural industry and its pathogens have been proved to be flacherie virus (FV) and densonucleosis virus (DNV). Multiplications of the viruses in the larvae of the silkworm, Bombyx mori, were studied by the sucrose density gradient centrifugation and electron microscopy. The quantitative and qualitative changes of nucleic acids and proteins were investigated from the midgut and hemolymph in the silkworm larvae infected separately with FV and DNV. The histopathological changes of epithelial cells of infected midgut also were examined by an electron microscope. 1. Purified fractions of FV or DNV in a sucrose density gradient centrifugation yielded one homogenous and sharp peak without a shoulder, suggesting no heterogenous materials in the preparation. Electron microscopy also revealed that FV and DNV were spherical particles, 27nm and 21nm in diameter, respectively. 2. Silkworm larvae showed a decrease in body weight on the 6th day and in midgut weight on the 3rd day after inoculation with FV or DNV. 3. DNA content was higher in the midgut when infected with FV or DNV, but the hemolymph of the infected larvae showed no difference during first 6 days after inoculation, after which DNA concentration declined rapidly. 4. RNA synthesis of silkworm larvae infected separately with FV and DNV was stimulated in the midgut, but RNA content was reduced in the hemolymph at the early stage of virus multiplication. At the late stage of virus multiplication, however, it was extremely reduced in both midgut and hemolymph. 5. The concentration of protein in the midgut and hemolymph of silkworm larvae infected separately with FV and DNV showed no difference from that of the healthy larvae at the early stage of virus multiplication, but it was significantly reduced at the late stage of virus multiplication. 6. There was no difference in the electrophoretic patterns of RNAs extracted from the midgut of healthy or virus-infected larvae. 7. The electrophoresis of proteins extracted from the midgut infected with FV or DNV, when carried out on the 1st and 5th day after virus inoculation, showed no difference from that of the healthy larvae. But, there was an additional band with medium motility in the proteins on the 8th day after virus inoculation, while a band with low mobility shown in the proteins of healthy larvae disappeared in the infected larvae. However, a band with high mobility in the healthy larvae was separated into two fractions in the infected larvae. 8. The electrophoretic pattern of hemolymph proteins of the silkworm larvae infected separately with FV and DNV was similar to that of the healthy larvae, but the concentration of hemolymph proteins in the infected larvae was lower than that of the healthy larvae at the late stage. 9. Two types of inclusion bodies were shown by the double staining of pyronin-methyl green in the columnar cell of the midgut on the 8th day after FV inoculation. 10. Electron microscopy of the infected midgut revealed that the 'cytoplasmic wall' of the goblet cell thickened on the 5th day after FV inoculation and several types of the cytopathogenic structures, such as virus$.$specific vesicles, virus particles, linear structures, tubular structures, and high electron-dense matrices were observed in the cytoplasm of the goblet cell. The virus particles were also observed in the microvilli and the structures similar to spherical virus particles were observed around the virus-specific vesicles, suggesting the virus assembly in the cytoplasm. 11. Fluorescence micrograph of the infected midgut stained with acridine orange showed that the nucleus, the site of DNV multiplication in the columnar cell, enlarged on the 5th day after virus inoculation. 12. Electron microscopic examination of DNV infected midgut revealed that the nucleolus of the columnar cell was broken into granules and those granules dispersed into apical region of the nucleus on the 5th day after virus inoculation. On the 8th day after inoculation, it was also observed that the nucleus of the columnar cell was full with the high electron-dense virogenic stroma which were similar to virus particles. These facts suggest that the virogenic stroma were the sites of virus assembly in the process of DNV multiplication.

• Korean Journal of Environment and Ecology
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• v.20 no.3
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• pp.345-351
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• 2006

This study investigates the toxic effects of $Cd^{2+}$on frog (Rana dybowskii) by the determination of oocyte maturation and development of embryo exposure to different concentrations of the toxicant. The results show that $Cd^{2+}$ concentration of 0.1ppm suppressed the maturation of the oocytes. To examine the reversibility of the inhibitory effects, the oocytes were exposed to the $Cd^{2+}$ only for 3 hours, and then transferred to plain medium and cultured further for 17 hours. The oocytes were recovered from the toxic effect of the $Cd^{2+}$ when they were exposed to 1ppm, but not to 2.5ppm of the $Cd^{2+}$. The development of 2 cell embryos to 32 cell was completely suppressed at 0.1ppm and the longer the embryos were exposed to the $Cd^{2+}$, the more damage appeared to the embryos and the cytolysis of the 32 cell was induced by $Cd^{2+}$ at 0.1ppm. On the other hand, the embryos of blastula stage were cultured 96 hours in presence of the $Cd^{2+}$ at various concentrations and were examined. The rates of mortality and malformed larvae were investigated by probit analysis. From the results of LC$_{50}$ of 0.1ppm and EC$_{50}$ of 0.08ppm, Tl of 5.0 was derived, which indicates $Cd^{2+}$ is to be considered a teratogenic compound. Such specific malformations occurred in 14.3% as spine deformations at the 0.05ppm, in 75.0% as tail deformations at the 0.1ppm, in 66.7% as abdominal deformations at the 0.01ppm and in 26.0% as profound deformations at the 0.1ppm of $Cd^{2+}$ concentration which living embryos were exposed to. $Cd^{2+}$ suppressed growth to head-tail length at 0.1ppm. In conclusion, The study results reveal that $Cd^{2+}$ must be considered highly toxic effect to oocyte maturation and embryonic development.