• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.13 no.2
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• pp.123-140
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• 2009

The effect of a solute concentration difference on the osmotic transport of water through the semi-permeable membrane of a simple cell model is investigated. So far, most studies on osmotic phenomena are described by simple diffusion-type equations ignoring all fluid motion or described by Stokes flow. In our work, as the governing equations, we consider the coupled full Navier-Stokes equations which describe the fluid motion and the full transport equation that takes into account of convection and diffusion effects. A two dimensional finite difference model has been developed to simulate the velocity field, concentration field, and semi-permeable membrane movement. It is shown that the cell swells to regions of lower solute concentration due to the uneven water flux through the semi-permeable membrane. The simulation is applied on a red blood cell geometry and the relevant results are presented.

• The Korean Journal of Mycology
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• v.11 no.3
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• pp.105-108
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• 1983

The mycelial growth of Pythium graminicola, P. ultimum, P. rostratum was best at -3 osmotic potential. P. monospermum was best grown at -8 bars osmotic potential. Mycelial growth by Pythium spp. was prevented at -42 bars for P. graminicola, P. ultimum and P. monospermum. Sporangial formation by P. graminicola and P. ultimum was influenced by water potential in much the same way as mycelial growth: -3 bars was maximum and -42 bars or below was minimal. Pythium spp. tested was grown faster on PDA than other media including oat meal agar. P. ultimum was best grown on any media among Pythium spp. tested.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.5
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• pp.626-635
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• 2009

An experiment was conducted to investigate the effect of Butylated Hydroxy Anisole (BHA), Butylated Hydroxy Toluene (BHT), Pentoxifylline (PTX), Theophylline (TPY) and Theobromine (TBR) on cold protection ability of Murrah buffalo semen at room ($22-25^{\circ}C$) and refrigerated temperature ($4-7^{\circ}C$). Each semen sample was divided into six parts of equal volume and sperm concentration; the first was kept as a control and the remaining five were treated with BHA, BHT, PTX, TPY or TBR. Sperm motility, abnormal spermatozoa, live-dead count, hypo-osmotic swelling and acrosomal integrity were studied at room and refrigerated temperature for various incubation periods viz.; 0, 4, 8, 12 and 24 h at room and 0, 12, 24, 36, 48, 60 and 72 h at refrigerated temperature. Significant improvement in sperm motility, live-dead count, hypo-osmotic swelling and acrosomal integrity were observed in BHT, PTX and TPY fortified extender at room and refrigerated temperature for various incubation periods. From the present study it could be concluded that cold protection ability of buffalo semen can be improved through the addition of BHT followed by PTX and TPY.

• Biomolecules & Therapeutics
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• v.17 no.4
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• pp.362-369
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• 2009

We have investigated the effect of glucosamine on the retinal cells after continuous infusion into cerebroventricle by using osmotic minipump to avoid peripheral effect. Continuous intracerebroventricular (i.c.v) infusion of glucosamine with the rate of 0.1 ${\mu}mol$/10 ${\mu}l$/hr for 7 days resulted in morphological changes of the optic nerve in electron microscopic level as well as morphological changes of the retina in light microscopic level. Retinal sections were immunostained for the detection of morphological changes of astrocytes. GFAP immunoreactivity appeared not only in the Muller cells but also many of the radial processes of Muller cells. The optic nerve showed deformed axon and slight lamellar separation of myelin sheath after continuous infusion of glucosamine in observing with electron microscope. Interestingly, vacuoles were observed in deformed axons and retinal layers were folded and detached. These results suggested that glucosamine plays a role in induction of morphological dysfunction in retina and optic nerves.

• Journal of Animal Science and Technology
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• v.63 no.1
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• pp.58-68
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• 2021

Several herbs including Artemisia are known to possess conceptive property. In the present study, mouse spermatozoa were incubated with ethanol extract of Artemisia vulgaris leaves. The effect of extract on acrosome exocytosis was studied by labeling spermatozoa with fluorescein isothiocyanate (FITC) peanut agglutinin and by staining with Coomassie blue. Viability and membrane integrity were studied by Trypan-blue staining and hypo-osmotic swelling test. Artemisia extract at very low concentration caused precocious acrosome reaction and loss of sperm viability. Acrosome reaction increased remarkably from 22.63% to 88.42% with increasing extract concentration from 0 to 2,000 ㎍/mL. However, the viability loss of spermatozoa was increased from 11.71% in control to 63.73% in samples treated, evaluated by Trypan-blue staining method. Membrane damage caused by the extract, evaluated by hypo-osmotic swelling test was even low, ranging from 2.27% to only 24.23%. These results indicate that Artemisia extract might block fertilization by causing precocious acrosome exocytosis in spermatozoa. A direct contraceptive effect was tested by injecting the plant extract into the vagina of female mice and then allowing them to mate with normal males. The treated female mice delivered significantly fewer litters in comparison to the control.

• Journal of the Korean institute of surface engineering
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• v.51 no.2
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• pp.95-103
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• 2018

Recently, many types of constructional steels have been often exposed to under severe corrosive environments due to acid rain with increasing environmental contamination. In order to inhibit their corrosion in severe corrosive environments, a painting method has been widely applied to numerous constructional steels of land as well as marine. Therefore, development of paint having a good quality of corrosion resistance is considered to be very important. In this study, four types of anti-corrosive paints (AP: Phenol epoxy, AC: Ceramic epoxy, AT: Coal tar epoxy, AH: High solid epoxy) were coated to the specimens, and then, were immerged in various salt solutions (0.1, 0.3, 3, 6, 9 and 15% NaCl solutions) for 11 days. And, the corrosion resistance of these samples by effect of osmotic pressure with salt concentration was investigated with electrochemical methods such as measurement of corrosion potential, impedance and corrosion current density. The corrosion current densities of all samples (AC, AT and AH) submerged in 3% NaCl solution exhibited the smallest values compared to other salt solutions. However, in the case of lower values of salt solutions than 3% NaCl solution, the corrosion current density increased again because it makes easier for water, dissolved oxygen and chloride ion etc. to invade toward inner side of coating film due to increasing of the osmotic pressure than 3% NaCl solution, but in the case of higher values of salt solutions than 3% NaCl solution, the coating film is easily deteriorated due to high concentration of chloride ion rather than the osmotic pressure, which resulted in increasing the corrosion current density. In particular, the AC sample indicated the best corrosion resistance in 6% NaCl solution compared to other samples. Consequently, it is considered that the corrosion mechanism of the coated steel plate is completely different from bare steel plate, and the corrosion resistance of coating film by osmotic pressure and chloride ion depend on various types of epoxy of paint in NaCl solution.

• Food Engineering Progress
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• v.22 no.4
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• pp.328-336
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• 2018

The aim of this study was to investigate the effect of pretreatments on quality of frozen peach. Pretreatments including steam blanching, water blanching, high pressure, and osmotic dehydration were applied to two varieties (Daeokgye and Hwangdo). Pretreated peaches were frozen and thawed at $-20^{\circ}C$ and $5^{\circ}C$, respectively. Steam blanching and osmotic dehydration with ascorbic acid reduced ${\Delta}E$ values without change of pH and acidity. Osmotic dehydration with sucrose decreased drip loss and increased brix. Freezing/thawing resulted in an increase of maximum force, while maximum force decreased with increasing time of steam and water blanching. Furthermore, osmotic dehydration with calcium chloride increased maximum force. High pressure decreased maximum force of Daeokgye and increased that of Hwangdo compared with non-treatment. Total polyphenol content, DPPH radical scavenging activity, and ABTS radical scavenging activity were improved by pretreatment including steam blanching, blanching, and osmotic dehydration with ascorbic acid.

• Journal of Bio-Environment Control
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• v.20 no.3
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• pp.204-210
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• 2011

This experiment was conducted to investigate the effect of water states (water, osmotic potential and turgor pressure) of fruit vesicle and leaf on soluble solids and organic acid contents of fruits of 'Shiranuhi' mandarin hybrid, M16 A line during the fruit maturing season in plastic house cultivation. The 'Shirauhi' grafted on 'Swingle citrumelo', strong strength of rootstock, produced fruit with lower soluble solids and organic acid content than 'Trifoliate' orange rootstock. The fruits vesicle water potential and turgor pressure measured before dawn in 'Swingle citrumelo' were higher tendency than the 'Trifoliate' orange, but osmotic potential values were lower than the 'Trifoliate' orange. The changes of leaf water potential were very similar to the fruit. The results suggest that in the 'Shirauhi' fruits grafted on two rootstocks changes of soluble solids and organic acid content of the fruit were influenced by the leaf water potential and the osmotic potential of the fruit vesicles, which might be caused by the difference of root distribution between two rootstocks.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.5
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• pp.824-830
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• 1996

In order to minimize the deterioration of osmotic dried apple quality, the characteristics of mass transfer during osmotic dehydration such as solid gain(SG), weight reduction(WR) and moisture loss(ML) were investigated. Moisture and solid transfer were analyzed by Fick's law. The highest (equation omitted)E value was observed with severe browning at $60^{\circ}C.$ The concentration effect on (equation omitted)E were higher at high temperatures than at low temperatures. SG, WR and ML increased as immersion temperature, sugar concentration and immersion time increased. Higher concentration of sucrose led to more sucrose absorption resulting increase in SG. Diffusion coefficients of moisture increased with immersion temperature and sugar concentration. As concentration increased, diffusion coefficients of solids increased at $20^{\circ}C$ while it decreased at $40^{\circ}C$ and $60^{\circ}C.$ Arrhenius equation was appropriately explain the effect of temperature on diffusion coefficients. Moisture and solid diffusion showed high activation energy in 20 。Brix solution, compared with in 40 and 60 。Brix.

• The Korean Journal of Physiology
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• v.17 no.2
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• pp.135-142
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• 1983

$PGE_2$ and $PGF_{2{\alpha}}$ are known to act similarly in a number of animal tissues. They both facilitate regression of corpus luteum(Poyser, 1972; Fuch et al, 1974; Coudert et at, 1974) and stimulate contraction of uterine muscle (Laudanski et al, 1977; Porter et al, 1979; Hollingsworth et al, 1980). It is, however, not known whether these two prostaglandins exert similar actions in osmotic fragility of erythrocytes (Rasmussen et al, 1975) and $PGF_{2{\alpha}}$ alters conformation of membrane proteins (Meyers aud Swislocki, 1974). The former effect may not be mediated through changes in c- AMP concentration in the cell, since the adenylate cyclase activity in human erythrocyte is extremely low (Rodan et al, 1976; Sutherland et al, 1962) and the latter effect implies that physical state (or fluidity) of the membrane is altered by $PGF_{2{\alpha}}$. The present study was undertaken to elucidate mechanisms of action of $PGE_2$ and $PGF_{2{\alpha}}$ on the human erythocyte membrane by examining their effects on osmotic fragility and $Ca^{++}$ binding to the membrane fragments. The results are summarized as follows: 1) $PGE_2$ and $PGF_{2{\alpha}}$ increased osmotic fragility at concentrations above $10^{11}\;M$, the effect being similar for both hormones. The concentration of NaCl for 100% hemolysis was $1/16{\sim}1/17\;M$ in the presence of $10^{11}\;M\;PGE_2$ or $PGF_{2{\alpha}}$ and 1/18 M in the absence of the hormone (control). 2) When erythrocytes were suspended in 1/15 M NaCl solution, $44.2{\pm}4.3%$ of cells were hemolyzed. Addition of $10^{12}\;M\;PGE_2$ or $PGF_{2{\alpha}}$ did not increase hemolysis. When the concentration of the hormones was increased to $10^{11}\;M$, however the degree of hemolysis increased markealy to about 80%. No further increase in hemolysis was observed at concentration of the hormones above $10^{11}\;M$. 3) The additional hemolysis due to $10^{11}\;M\;PGE_2$ and $PGF_{2{\alpha}}$ appeared to he identical regardless of absence or presence of $Ca^{++}\;(0.5{\sim}10\;mM)$ in the suspending medium. 4) In the absence of prostaglandin, the binding of $Ca^{++}$ to the erythrocyte membrane increased curvilinearly as the $Ca^{++}$ concentration increased up to 5 mM above which it leveled off. A similar dependence of $Ca^{++}$ binding on the $Ca^{++}$ concentration was observed in the presence of $10^{11}\;M\;PGE_2$ or $PGF_{2{\alpha}}$, however, the amount of $Ca^{++}$ bound at a given $Ca^{++}$ concentration was significantly higher than in the absence of the hormones. 5) As in the hemolysis, $PGE_2$ and $PGF_{2{\alpha}}$ did not affect the $Ca^{++}$ binding at a concentration of $10^{12}\;M$, but increased it by about 100% at concentration above $10^{11}\;M$. These result indicate that both tile osmotic fragility of erythrocyte and the $Ca^{++}$ binding to the erythrocyte membrane are similarly enhanced by $PGE_2$ and $PGF_{2{\alpha}}$, but these two effects are not causally related. It is, therefore, concluded that the prostaglandin-induced hemolysis is not directly associated with alterations of the $Ca^{++}$ content in the membrane.