• Korean Journal of Ichthyology
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• v.12 no.2
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• pp.111-117
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• 2000

There were observed the histomorphological alterations such as chloride cell hyperplasia, branchial lamellar epithelial separation, the increased cellular turnover of chloride cells, glomerular shrinkage and blood congestion in rainbow trout (Oncorhynchus mykiss) during the seawater adaptation. The ultrastructure by scanning electron microscope (SEM) indicated that the gill secondary lamella of rainbow trout exposed to seawater, were characterized by rough convoluted surfaces during the adaptation. There were observed a large number of mitochondria with the elongate and well-developed cristae in chloride cells exposed to seawater by transmission electron microscope (TEM). The presence of two mitochondria- rich cell types is discussed with regard to their possible role in the hypoosmoregulatory changes which occur during seawater-adaptation. Glomerulus shrinkage and blood congestion were occurred higher in nephrons of seawater-adapted fish than those living in freshwater. Our findings demonstrated that rainbow trout tolerated moderately saline environment and the increased body weight living in seawater was relatively higher than that living in freshwater in spite of histopathological changes.

• Applied Biological Chemistry
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• v.38 no.3
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• pp.218-223
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• 1995

Osmolytes accumulated in the osmotically stressed Yersinia enterocolitica ATCC 9610 were investigated using natural abundance $^{13}C$ NMR spectroscopy. Glycine betaine, one of the more common and most effective osmolytes found in nature, was the dominant osmolyte in osmotically stressed Y. enterocolitica cells. Glycine betaine concentration was 41.8 times higher (801.9 nmol/mg protein) in stressed cells than in unstressed cells (19.2 nmol/mg protein). Proline was the minor osmolyte, and its concentration was 284.8 nmol/mg protein. The effects of glycine betaine and related osmolytes on growth rate of osmotically stressed Y. enterocolitica were investigated to identify their ability as osmolytes for Y. enterocolitica. When glycine betaine and proline were added in MMA medium containing 2.5% NaCl, the growth rate with glycine betaine (1 mM) was 3.6 times higher than in control (no addition of osmolyte), and that with proline was 1.3 times higher. Dimethylglycine (5 mM) also increased the growth rate 3.1 folds. On the other hand, monomethylElycine had no effect on growth of osmotically stressed and unstressed Y. enterocolitica. When carnitine was added in MMA medium containing 2.5% NaCl, carnitine (5 mM) increased the growth rate 2.4 folds, but choline had no effect on growth of osmotically stressed Y. enterocolitica. The above results indicate that glycine betaine is the dominant osmolyte in osmotically stressed Y. enterocolitica, and proline, dimethylglycine and carnitine also act as minor osmolytes.

• Journal of The Korean Association For Science Education
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• v.22 no.3
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• pp.444-454
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• 2002

In this study, we analyzed the explanation of the concepts related to osmotic pressure and semipermeable membrane that were represented in chemistry and biology textbooks of high school and general course of college. There were 4 types of explanation in osmotic pressure and 3 types of semipermeable membrane concept. Students can understand the concepts with different meaning because there are different viewpoints on the explanations of the concepts. We must consider the various types of explanation when we design science textbooks because these confusions disturb students' understanding of the concepts.

• Journal of the East Asian Society of Dietary Life
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• v.9 no.3
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• pp.386-390
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• 1999

소금은 공기나 물과 마찬가지로 사람이 생명을 유지하는 데에 없어서는 안 될 중요한 물질이다. 즉 체액의 삼투압의 균형유지, 신경이나 근육의 활동조절 등을 통하여 생명유지에 중요한 역할을 수행한다. 즉 영양분을 운반하거나 신진 대사를 하거나 노폐물 등 물질이 이동될 때에는 삼투압이 근 구실을 하게 되는데 소금은 이와 같은 체액의 삼투압이 균형을 유지할 수 있도록 하는 것이다. 이외에 소금은 위액의 염산이 되어 살균 작용이나 소화작용을 도와준다. 또한 소금은 간접적으로 적혈구의 생성을 도우며 발한 작용을 통하여 체온의 적절한 유지 기능도 가지고 있다. 이외에 최근 여러 사람이 이용하고 있는 죽염의 기능성 여부에 대하여도 과학적인 규명이 필요한 것으로 보인다.

• Microbiology and Biotechnology Letters
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• v.13 no.3
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• pp.311-314
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• 1985

Ganodema lucidum protoplasts were formed by the treatment of Novozym 234. The osmotic stabilizers such as mannitol were effective enough to produce protoplasts up to 10$^{6}$ $m\ell$. For regeneration, however, MgSO$_4$.7$H_2O$ was suitable. When inositol and sucrose were employed as osmotic stablizers, the regeneration ratio reached to 0.26％. Overlay of Streptomycin sulfate added agar was required to prevent bacterial contamination.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.10a
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• pp.287-288
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• 2001

해산어류의 담수순화에 관한 연구는 일부 광염성 어종에 대해 수행되어 왔으나, 극히 미비한 실정이다 담수순화에 관한 연구는 아가미 구조적 연구, 내분비학적 연구 등이 연어과 어류의 회유시에 밝혀진 바 있다(Chen and Lin., 1994). 다른 해산어류의 삼투압조절 등 생리학적 연구는 숭어의 담수사육에 관한 기초연구 결과가 보고(장과 허, 1999)되고 있다. 그러므로 이러한 삼투압조절 능력 등이 실제 산업에 이용되려면 각각의 양식유용종에 대한 상세한 연구와 각 어종의 염분 내성, 삼투압조절 능력, 염분변화에 따른 생존 및 성장 그리고 삼투압조절 기능을 향상시키기 위한 물리적, 화학적, 생리학적 연구 등이 필요하다. (중략)

• Polymer(Korea)
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• v.32 no.4
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• pp.328-333
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• 2008

The osmotic delivery systems are based on osmosis. The transverse diffusion of water through a porous membrane from a medium with a low osmotic pressure to a medium with a high osmotic pressure. Nifedipine tablet dosage forms of Procardia $XL^{(R)}$(Pfizer) and $Adalat^{(R)}$(Bayer) are commercialized systems of this type that push-pull osmotic tablet operates successfully in delivering water-insoluble drugs. We prepared osmotic pellet system by fluidized bed coating method, and model-drug used nifedipine. The osmotic pellet system was composed of the core material. the swelling and osmotic pressure layer, the drug coating layer, and the porous membrane. This work is performed to investigate the effect of different factors, such as composition and thickness of membrane. The osmotic pellet has been successfully prepared by fluidized bed coating technology. The drug release behavior depended on the increase of CA ratio and thickness in porous membrane. The morphology of the osmotic pellet before and after the dissolution test were observed by SEM. In conclusion, we found that the drug release of osmotic pellet depended on the composition and coating thickness of porous membrane.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2003.05a
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• pp.244-245
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• 2003

한국의 내수면 어류양식은 송어, 틸라피아 및 잉어류가 주류를 이루고 있으나 과잉생산으로 인해 경제성이 낮으며, 최근 수입개방과 환경오염으로 담수양식 산업이 어려움에 처해 있는 실정이다. 따라서 새로운 고가의 양식어종 개발은 내수면 어류양식에 있어 시급히 해결해야 할 중요한 과제이다. 이러한 문제를 해결하기 위하여 최근에 광염성 해산어류의 뛰어난 삼투압 조절능력을 응용한 감성돔의 담수순화 양식이 시도되고 있다. (중략)

• Membrane Journal
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• v.12 no.2
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• pp.90-96
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• 2002

A novel methodology on the calculations of osmotic pressure and gradient diffusion coefficient has been provided ill the present study, by applying a succinct numerical analysis on the experimental results. Although both the osmotic pressure and the gradient diffusion coefficient represent a fundamental characteristic in related membrane filtrations such as microfiltration and ultrafiltration, neither theoretical analysis nor experiments can readily determine them. The osmotic pressure of colloidal suspension has been successfully determined from a relationship between the data of the time-dependent permeate flux, their numerical accumulations, and their numerical derivatives. It is obvious that the osmotic pressure is gradually increased, as the particle concentration increases. The thermodynamic coefficient was calculated from the numerical differentiation of the correlation equation of osmotic pressure, and the hydrodynamic coefficient was evaluated from the previously developed relation for an ordered system. Finally, the estimated gradient diffusion coefficient, which entirely depends on the particle concentration, was compared to the previous results obtained from the statistical mechanical simulations.

• Korean Journal of Food Science and Technology
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• v.22 no.5
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• pp.497-502
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• 1990

The effect of sugar concentration, immersion time and temperature on water loss, solid gain or loss, and sugar molality of potatoes during osmotic concentration was analyzed by a response surface methodology (RSM), and those values were predicted by using a second degree polynomial regression model. Effect of osmotic concentration and blanching on vitamin C retention of air dried potatoes (6% MC: wet basis) was also evaluated. The most significant factor was sugar concentration for water loss, solid gain or loss, sugar molality, rate parameter and retention of vitamin C. Second and third factors were immersion time and temperature respectively. Water loss and solid gain were rapid in the first 10 min and then levelled off. A 44.6% of water loss was observed during osmotic concentration using a sugar solution $(60\;Brix,\;80^{\circ}C$) with 20 min of immersion time. Dried potatoes after osmotic concentration had higher vitamin C content than dried potatoes after blanching. Optimum regions for osmotic concentration process of potatoes were $60-70^{\circ}C$ of immersion temperature, 60 Brix of sugar solution and 16-20 min of immersion time based on above 30% of water loss and 50% of vitamin C retention.