• Fisheries and Aquatic Sciences
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• 제13권4호
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• pp.343-349
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• 2010

The effects of osmotic stress on the non-specific immune response of Nile tilapia, Oreochromis niloticus, were investigated. Osmoregulatory mechanism of tilapia has been studied, but less information is available about innate immune response of O. niloticus faced with hyperosmolality. Acute osmotic stress was elicited by transferring tilapia from freshwater (FW) to 24 psu seawater (SW). Non-specific immune parameters including lysozyme activities of plasma and head kidney (HK), alternative complement pathway (ACP) activity in plasma, phagocytic capacities of spleen and HK immune cells, and respiratory burst activity of immune cells in both HK and spleen were analyzed. Lysozyme activities were increased at 1 h and 30 h after transfer to SW, but decreased at 10 h after SW transfer. Conversely, ACP activity increased 10 h after SW transfer. Phagocytic capacity increased slightly at 1 h and 5 h after SW transfer, and respiratory burst activity showed an increase in superoxide release at 10 h after SW transfer. Taken together, these results indicate that the exposure of tilapia to hyperosmotic conditions has immunostimulatory effects on cellular and humoral immune reactions.

• Journal of Plant Biotechnology
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• 제4권2호
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• pp.71-76
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• 2002

In order to achieve repetitive somatic embryogenesis in cacao (Theobroma cacao L.), callus derived from floral tissues were continuously cultured in a medium containing 2,4-D. In 5% of the explants, repetitive somatic embryogenesis was observed after 8 weeks and maintained in a globular stage for several weeks. This is the first report showing repetitive somatic embryogenesis in cacao. The calli were bombarded with a plasmid containing $\beta$-glucuronidase (gus) as reporter gene. Two week old calli showed the high average number of cells expressing the us gene. The effect of osmotic agents (mannitol, sorbitol and sucrose) on gene expression was evaluated. Pre-treatment during 16 h with 0.25 M mannitol revealed an improvement in gene expression. The potential utilization of the repetitive embryogenesis, combined with osmotic treatment, is discussed as an alternative to achieve stable transgenic cacao plants.

• Plant Biotechnology Reports
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• 제4권1호
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• pp.75-83
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• 2010

Glycine betaine has been reported as an osmoprotectant compound conferring tolerance to salinity and osmotic stresses in plants. We previously found that the expression of betaine aldehyde dehydrogenase 1 gene (OsBADH1), encoding a key enzyme for glycine betaine biosynthesis pathway, showed close correlation with salt tolerance of rice. In this study, the expression of the OsBADH1 gene in transgenic tobacco was investigated in response to salt stress using a transgenic approach. Transgenic tobacco plants expressing the OsBADH1 gene were generated under the control of a promoter from the maize ubiquitin gene. Three homozygous lines of $T_2$ progenies with single transgene insert were chosen for gene expression analysis. RT-PCR and western blot analysis results indicated that the OsBADH1 gene was effectively expressed in transgenic tobacco leading to the accumulation of glycine betaine. Transgenic lines demonstrated normal seed germination and morphology, and normal growth rates of seedlings under salt stress conditions. These results suggest that the OsBADH1 gene could be an excellent candidate for producing plants with osmotic stress tolerance.

• 현장농수산연구지
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• 제21권1호
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• pp.41-48
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• 2019

This study was carried out to establish a proper cultivation site and to diagnose the drought tolerance of Oplopanax elatus leaves by using pressure-volume curves. As a result of analysing data measured, the leaf of Oplopanax elatus showed the osmotic pressure at full turgor(Ψosat) was -0.77 MPa, and the osmotic pressure at incipient plasmolysis(Ψotlp) was -0.90 MPa. Then, the value of maximum bulk modulus of elasticity Emax was 3.7 MPa, showing that slightly lower drought tolerance of Oplopanax elatus. Furthermore, the values of relative water contents RWCtlp and RWC^* were above 80%, showing that the function of osmoregulation is somewhat better. Thus, responses to water relations such as Ψosat, Ψotlp, Emax, RWCtlp and RWC^* of Oplopanax elatus showed relatively lower drought-tolerance property indicating that those growth are appropriate in high moisture soil sites.

• 한국과학교육학회지
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• 제27권2호
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• pp.144-152
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• 2007

In this study, high school science teachers' and students' various conceptions related to osmosis phenomena were compared with and analyzed in relation to the content of science textbooks used in high school science classrooms and college science courses. The questionnaires developed by the researchers were administered to science teachers and students. Differences can be found between the explanations of science textbooks on osmotic pressure and semi-permeable membranes. Many science teachers and students thought of osmotic pressure as 'membrane pressure occurred by the movement of a solvent'. Moreover, the types of teachers of semi-permeable membranes were similar regardless of their academic majors. Many of the teachers thought of a semi-permeable membrane as a membrane that 'passes small-size particles'; however, many students thought of this type of membrane as being 'selectively permeable'. Also, the salt-pickling cabbage phenomenon seemed to cause significant confusion to science teachers and students. These study results show that teachers and students possess various conceptions related to the osmosis phenomena. These different conceptions related to osmosis phenomena might cause confusion and diverse conceptions including misconceptions among teachers and students.

• The Korean Journal of Physiology
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• 제9권1호
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• pp.33-37
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• 1975

Adult rabbits were anesthetized with nembutal, 30 mg/kg. Carotid artery and jugular vein were exposed surgically and cannulated with polyethylene tubing. Arterial blood pressure was recorded via pressure transducer on the physiograph and $100{\mu}g/ml$ of histamine solution was infused through the jugular vein by using the constant infusion pump with a rate of 0.92 ml/min or 1.40 ml/min. Mean arterial blood pressure was maintained at $40{\sim}70 mmHg$ and hypotension was kept for 2 hours. After the termination of this period, blood was taken and osmotic fragility was mea sured immediately. Also, every sample of normal blood and shocked blood was incubated for 1 hour or 2 hours at $37^{\circ}C$ in order to see whether or not there was some influence of incubation. Furthermore to clarify which component was responsible for the change on the fragility, the mixtures of normal blood cells with shocked plasma and shocked blood cells with normal plasma were also incubated at $37^{\circ}C$ for one or two hours and fragility in such cases was measured. The data obtained were analysed by probit-plot method and the concentration of saline solution at which the hemolysis started to occur, 50% of blood cells were hemolysed and that at which the red blood cells hemolysed completely were determined. The values for the blood of hypotension stage were compared with those of the control blood. The results obtained were as fellows: 1. Osmotic fragility of red blood cell was increased in hypotensive state induced by histamine. 2. The differences of osmotic fragility after two hours of incubation were negligible both in normal blood and in that of hypotensive state. 3. Osmotic resistance of normal red blood cell incubated in shock plasma was less than that of shock red blood cell incubated in normal plasma. It was suggested that plasma in hypotensive state caused by histamine might be primarily responsible for the alteration of red blood cell fragility.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.216-216
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• 2017

Primed seeds germinate faster and uniformly, since these have already started imbibition and metabolism requiring to complete germination. Several factors such as solution composition, osmotic potential, and treatment duration affect seed priming response. Water potentials of priming solution and germination response of primed seed were investigated to clarify the effects different inorganic salt types and the duration. Pepper seeds were primed in osmotic solutions that were osmotic potential ranged -1.54 to -0.45 MPa in an aerated solution of polyethylene glycol 8000 (PEG; 17%, 22%, 27%), and inorganic salt solution of $KNO_3$, $K_2SO_4$, and $Na_2SO_4$ (100, 200, 300mM) in aerated condition. The seeds were treated at $20^{\circ}C$ for 4, 6 day (D) and stepwise duration combined concentration of 100mM (2 or 4 days) and 300mM(2 or 4days). After soaking treatment, seeds were washed with distilled water and then were dried to approximately 6% moisture content in dry chamber at $25^{\circ}C$. The germination of seed was characterized by ISAT rules at $20^{\circ}C/30^{\circ}C$ and $15^{\circ}C$. Total germination percentage (GP), mean germination time (MGT), germination uniformity (GU), germination rate (GR), and health seedling percent (HS) were calculated on the germinated seed in a 14-day period. Seed water potential (${\psi}$) was correlated with water potential of priming solution ($r^2=0.84$). The effect of seed priming on germination varies with inorganic salt and organic agents (PEG). Germination percentage (GP, 77 and 73%), GR (21.3 and $19.4 %{\cdot}day^{-1}$), and HS (58 and 52 %) was greatest and lowest MGT (4.2 and 4.8 day) when they were primed in 100mM $K_2SO_4$ (${\psi}=-0.45MPa$), and 100mM $KNO_3$ (${\psi}=-0.52MPa$) for 6 days compared to untreated control (67% GP, $19.7%{\cdot}day^{-1}\;GR$, 18% HS, and 10.8 day MGT) in $15^{\circ}C$ chamber. Water potential less then -1.2MPa of osmotic solution resulted lower GP, GR and HS and in $K_2SO_4$ and $KNO_3$. However, stepwise treatment of water potential that changed solution as 100mM for 4 D + 300mM for 2 D or 300mM for 4 D + 100mM for 2 D) were not better than single concentration alone in germination characteristics.

• 한국표면공학회지
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• 제51권2호
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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.

• 한국잡초학회지
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• 제30권2호
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• pp.84-93
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• 2010

다양한 환경조건에서 미국좀부처꽃의 발아 및 출아 특성을 평가하기 위하여 식물생장상에서 페트리 디쉬와 포트 실험을 수행하였다. 미국좀부처꽃은 $35/30^{\circ}C$와 0 bar의 삼투포텐셜 조건에서 발아가 가장 잘되었으나 온도가 $15^{\circ}C$ 이하나 $40^{\circ}C$ 이상, 삼투포텐셜이 -2.0 bar 이하와 암조건에서 발아되지 않았다. 출아의 최적온도는 $35/30^{\circ}C$로 판단되며 이 조건에서 파종 후 7일차에 출아가 개시되어 10일차에 최대 출아율에 도달하였으며, 온도가 $15/10^{\circ}C$ 이하나 $40/35^{\circ}C$ 이상 조건에서는 출아가 안 되거나 현저히 감소하였다. 파종심도의 증가에 따라 출아율은 현저히 감소하여 3 cm 이상의 파종심도에서는 출아하지 않았다. 비선형회귀분석을 한 결과 파종 후 시간의 경과에 따른 미국좀부처꽃의 누적 발아 및 출아는 Gompertz 모델로 잘 설명되었으며 삼투포텐셜에 따른 발아와 파종심도에 따른 출아는 logistic 모델로 잘 설명되었다. 결론적으로 미국좀부처꽃은 광발아성으로 발아 및 출아 가능 온도는 $15^{\circ}C$ 이상, 삼투포텐셜은 -2.0bar 이상, 토양심도는 3 cm 이하임을 본 연구를 통하여 확인하였다.

• 한국식품과학회지
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• 제29권4호
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• pp.722-729
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• 1997

염지어의 동결저장시 품질변화를 최소화 하기 위한 연구로써, 2종의 어류(고등어, 조피볼락)를 저온삼투압 탈수법으로 전처리한 다음 동결저장$(-18{\pm}2^{\circ}C)$ 중 품질안정성을 검토하였다. 갈변도는 탈수시트로 처리한 염지어가 무처리 염지어 보다 저장 중 증가폭이 적었으며, 과산화물값 및 카로보닐값의 경우 동일어종간에 있어 탈수시트 처리유무에 관계없이 저장 중 증가폭은 거의 차이가 없었다. 또한 가압 및 유립드립의 발생량은 탈수시트로 전처리한 것이 무처리한 염지어 보다 적었고, 보수력도 우수하였다. 한편 염용성질소 함량 및 Ca-ATPase 활성 잔존율은 동결저장 중 저온삼투압 탈수법으로 전처리한 염지어가 무처리 염지어에 비해 높은 값을 나타내었으며, 어종간의 변화폭은 고등어가 조피볼락에 비해 상당히 크다는 것을 알 수 있었다. 동결저장 7일째의 근육조직을 전자현미경으로 관찰해본 결과, 탈수시트로 전처리한 염지 고등어 및 조피볼락은 근원섬유의 기본적 구조 및 Z선이 뚜렷하게 유지 되었지만, 무처리 염지어는 근원섬유의 기본적 구조 및 Z선이 불명확하거나 붕괴되어 있었으며, 특히 염지 고등어가 염지 조피볼락에 비해 동결저장 중 근육조직의 붕괴가 심하였다. 이는 본 저온삼투압탈수법이 냉동내성이 약한 어류에 적용시키면 더 효과가 있다는 것을 의미한다. 이상의 화학 및 조직학적 관찰의 결과로 미루어 볼 때, 탈수시트로 전처리한 후 염지어를 동결저장하면, 여러가지 품질악변 중에서 특히 단백질의 변성을 최소화 할 수 있어 향후 다른 어육냉동식품의 shelf life 연장에도 응용가능하리라 생각된다.