• The Korean Journal of Physiology
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• v.8 no.2
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• pp.67-74
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• 1974

The object of this research is aimed to determine the activity of adenyl cyclase in both skeletal muscle sarcolemma and fat cell ghost of epididymal adipose tissue isolated from rats exposed to cold for various length of time in an attempt to evaluate whether the tissue sensitivity to catecholamine is increased when rats are exposed to cold for long periods of time Methods: a)Animals: Albino rats ranging in weight from 150 to 200 gm were used throughout this study. For experimental purposes, the rats are divided into two groups: experimental animals were place4 in a cold room at $4^{\circ}C$, controls being kept at $25^{\circ}C$. At the end of 2, 4, 6, 12, and 16 weeks. exposure to cold the rats were used to measure the adenyl cyclase activity. b) Isolation of plasma membrane from skeletal muscle and adipose tissue: The Plasma membrane of skeletal muscle from hind limbs of rats are prepared by the method employed by Rosenthal et at. and fat cell ghost of epididymal adipose tissue of rats by the method employed by Rodbell. c) Adenyl cyclase assay: Adenyl cyclase activity were measured by the method employed by Marinetti et al. Briefly, plasma membrane was incubated with $3^H-ATP$, various amount of noradrenaline and other incubation mixture at $37^{\circ}C$ for 20 minutes. After stopping the enzyme reaction by immersion in boiling water, carrier 3',5'-AMP was added to the system as a marker and $100\;{\mu}1$ aliquots of incubation mixture were pipetted on $20{\time}20$ Whatman No. 3 MM filter paper for one dimensional chromatography. The cyclic AMP spots were cut off and placed in counting vials containing 10ml of Bray's scintillation cocktail. Radioactivity was determined with a Packard Tri-Carb liquid scintillation counter. The enzyme activity is expressed as nanomoles of cyclic AMP produced per mg of membrane per hour. Result: 1. Average adenyl cyclase activity in the plasma membrane of skeletal muscle before and after noradrenaline administration was significantly higher in the cold-exposed rats as compared to the control. Continuous exposure to cold Produced an increased adenyl cyclase activity before and after noradrenaline administration. Adenyl cyclase activity reached peak levels at the 6 weeks exposure to told and level of adenyl cyclase activity remained high. Noradrenaline administration to the incubation medium induced a significant increase in adenyl cyclase activity and the degree of stimulation were proportional to the hormonal concentration But the rate of inclement in adenyl cyclase activity by noradreasline was the same in both groups. 2. Adenyl cyclase activity in fat cell ghost between cold exposed and control rats showed no significant differences before and after noradreualine administration. In summary, it can be concluded that cold adaptation give rise an increased activity of adenyl cyclase in plasma membrane of skeletal muscle in rats.

• Journal of Plant Biology
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• v.12 no.1
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• pp.22-30
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• 1969

To investigate the effects of internal radiation of various intensityon the test crop(flax), seeds of four levels of activity($15.5{\times}10-4 $\mu$c/grain, 9.0{\times}10-2$\mu$c/grain, 2.2{\times}100$\mu$c/grain and 3.8{\times}10-1$\mu$c/grain)$ which had been obtained by immersing them into various concentrations of P-32 original solution (total activity: 90 mc, To: 3/21) for 24 hours at room temperature, were germinated, transplanted later into pots, and the rate of germination and the successive growth were observed, and the inorganic conents of the plant top were analyzed. The results are as follows: 1. At the early stage of germination, the plants manifested themselves both inhibitory and promotive effects at higher and lower activity levels respectively, compared those of the control. These difference of growth on account of different levels of activity appeared, however, to be gradually narrowed in the course of time after germination, except at the highest activity. 2. Two weeks after transplanting, the plants of the lowest activity showed more vigorous growth than those of control. The plants belonging to the other activity levels on the other hand, tended to be less growing, the higher the activity. However, this growth gap between treatments seemed to be progressively closed one month after transplanting. 3. Most of the leaves and stems of the plants belonging to the highest activity level ($3.8{\times}101$\mu$c/grain$) were withered during the early stage of growth, and this damage did not recover. 4. Practically no difference of growth was observed among treatments(excluding that of highest activity) one and half months after transplanting. 5. The fluorescence tended to be mroe delayed than the control, as the activity decreased. 6. There was a tendency that the number of pods harvested were larger in the plants treated with P-32 than that of the control. 7. The proportion of fiber in the plants at harvest appeared to be larger at lower activity and smaller at higher P-32 concentration than that of control. 8. As for the inorganic contents of the plant top harvested the floowing tendency was observed: (1) Nitrogen content was highest at the highest activity level at which the poorest growth ensued. (2) There was no clear difference of phosphorus content among treatments. (3) The contents of potassium and magnesium were higher than control at the medium levels of activity. (4) Calcium content of all treated blocks was found to be more than that of control.

• Journal of the Korean Applied Science and Technology
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• v.40 no.2
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• pp.268-276
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• 2023

The purpose of this study is to investigate how the presence experience of virtual reality sports room class affects the intention to participate in sports activities when pleasure and immersion are experienced. For the survey, a total of 300 people, 60 copies each, were sampled for the upper grades of elementary school, and a total of 276 copies of data were used for the study, excluding 24 copies with insincere answers from among the questionnaires. The data processing used in this study was SPSS ver. 24.0 and AMOS ver. 24.0 Statistical program was used to perform confirmatory factor analysis, frequency analysis, Cronbach's α coefficient calculation, correlation analysis, and structural equation model analysis. Through this procedure, the following results were derived. First, the presence experience of the virtual reality sports room class had a positive effect on enjoyment. Second, the relationship between enjoyment and immersion in virtual reality sports room classes had a positive effect. Third, the enjoyment of the virtual reality sports room class had a positive effect on the intention to participate in sports activities. Fourth, the class immersion of the students who participated in the virtual reality sports room had a positive effect on their intention to participate in future sports activities.

• Korean Journal of Construction Engineering and Management
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• v.1 no.3 s.3
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• pp.75-80
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• 2000

In scheduling multi-unit projects, several alternatives can exist in network construction due to repetitiveness of their activities. Project duration is affected not only by the duration of each activity but also by the arrangement of repeating activities in such projects. This paper provides a network compression method that assigns predecessors to each activity to minimize its float time. Different to the previous efforts that utilized line of balance as the base scheduling-model, this research adopts precedence diagram arranged in two coordinates, the space axis and the resource one. This method seeks the most appropriate predecessors for each activity in each direction of the two coordinates for the purpose of minimizing the idle resource and space. This activity arrangement method was applied to a multi-unit apartment-construction project, to prove its capability of network compression. The result shows that the method successfully sought room for saving construction duration by changing the activity arrangement. The network compression method presented in this research can be utilized in multi-unit construction projects such as apartment complex projects.

• The Korean Journal of Physiology
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• v.23 no.1
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• pp.35-42
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• 1989

The present study was performed to observe the effects of cations on resting membrane potential and pump activity in the unfertilized eggs of ICR strain mice. After an induction of superovulation, the fresh eggs with zona pellucida were collected and the membrane potentials were recorded. Recordings of membrane potential in this study was obtained from the physiological conditions ($37^{\circ}C$ and 4mM Ca in standard solution), differently from the another reports with unphysiological conditions (room temprature and high Ca in standard solution) for a stable and long-lasting observations. Presented data was obtained within 6 hours after collection from the oviduct. The results observed are as follows, 1) Resting potential of the unfertilized eggs was $-25.8{\pm}3.8mV$ $(Mean{\pm}Se,\;n=31)$. 2) As the K ion concentration was increased, resting membrane potential was depolarized but showed hyperpolarization with $K^{+}$ below 25mM. 3) Alteration of the resting membrane potential for the changes of $Na^{+}$ concentration were hardly observed, while resting potential was hyperpolarized as $Ca^{2+}$ concentration was increased. 4) Pump activity as transient or prolonged hyperpolarization was $-2.29{\pm}0.75mV$ $(Mean{\pm}Se,\;n=16)$, the hyperpolarization was increased in both amplitude and duration under the 10mM $Ca^{2+}$ solution. 5) Hyperpolarization due to pump activity was decreased or disappeared by $5{\times}10^{-5}\;M$ ouabain treatment and could not be observed under the both Na-free and Ca-free solutions. 6) Above results are likely to suggest that the resting potential of the mouse unfertilized eggs is affected to mainly by Ca-dependent K conductance and Na-Ca exchange mechanism and that there is pump activity coupling between $K{+}$, $Na^{+}$ and $Ca^{2+}$.

• The Korean Journal of Food And Nutrition
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• v.27 no.5
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• pp.796-804
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• 2014

This study was conducted to investigate the effect of the addition of dandelion on color, texture, and antioxidant activity in Jeolpyon. Jeolpyon was prepared with varying amounts of dandelion ranging up to 20%. They were stored for 3 days at room temperature, and the color and texture were analyzed at different time intervals. L and a values decreased with increasing dandelion concentration while b values increased with increasing dandelion concentration in Jeolpyon. From texture analysis by Rheometer, the hardness and chewiness seem to be affected dramatically by the addition of dandelion in Jeolpyon. During storage, the control Jeolpyon without dandelion displayed greater than two fold increase in hardness, chewiness and brittleness, while the Jeolpyon with added dandelion had only slight increase during storage. The addition of dandelion in Jeolpyon also increased antioxidant activities such as DPPH radical scavenging activity, ABTS radical scavenging activity and reducing power. The antioxidant activities increased linearly with increasing dandelion concentration in Jeolpyon. The increase of antioxidant activities in Jeolpyon with the addition of dandelion may be attributed to the polyphenols in dandelion since the amount of total polyphenols increased with increasing amounts of dandelion in Jeolpyon. In sensory evaluation, the panels of twenties, thirties, and forties gave high scores to Jeolpyon with dandelion containing 10% 15%, and 20%, respectively in overall evaluation.

• The Korean Journal of Physiology
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• v.16 no.2
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• pp.119-128
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• 1982

The frog truncus arterious were studied with conventional glass microelectrode technique in order to elucidate the underlying mechanism of spontaneous pacemaker activity. The analyses were focussed on the ionic nature of pacemaker current by changing the concentrations of extracellular $K^+$ and, $Na^+$, or by using blockers of K- and Ca-current and chronotropic transmitters. 1) The action potential of the spontaneously active truncus arteriosus has some characteristic feature of maximal distolic potential ranged from -65 to -75 mV, resting potential from -45 to -50 mV and overshoot voltage about +30 mV, respectively. Duration of the action potential taken from rapid upstroke to maximal diastolic potential was about 600 msec. Usual discharge rate was $25{\sim}30/min$ at room temperature $(18{\sim}20^{\circ}C)$. 2) The sensitivity of the resting membrane potential to change extracellular potassium concentrations $(0{\sim}12\;mM)$ was relatively low. Transient hyperpolarization was appeared in the 12 mM K Ringer after 10 min exposure to 0 mM K and it could be related to Na-pump reactivation by high potassium. 3) Reduction of extracellular sodium concetrations diminished the amplitude and frequency of the action potential. In Ringer solution containing 30% Na (substituted by equimolar Tris), spontaneous activity stopped but reappeared as very slow and small action potential. There was no spotaneous activity in zero Na Ringer solution. 4) Caesium(10 mM), K-current blocker decreased the frequency of the action potential and also pacemaker depolarization. Manganese (2 mM) known to be Ca-current antagonist, blocked spontaneous activity completely. 5) Adrenaline and acetylcholine had no chronotropic effect. But adrenaline increased the duration of plateau phase and the magnitude of the action potential in the follower cell. It is concluded that K-, Na-and Ca-current components are involved in the genesis of spontaneous activity of the frog truncus arteriosus like cardiac pacemaker tissues. But the insensitivity of truncus arteriosus to adrenaline and acetylcholine indicates that there are some different control mechanisms of spontaneous rhythm in two tissues.

• Ocean and Polar Research
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• v.38 no.2
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• pp.129-137
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• 2016

This study aimed to isolate and characterize sulfated polysaccharides (SPs) from Iridaea cordata and evaluate their anticancer activity. SPs of the Antarctic red seaweed were obtained by $CaCl_2$ (SP1) and ethanol precipitations (SP2) following diluted acid extraction at room temperature. Yields of SP1 and SP2 were approximately 14% and 23%, respectively, of the dry weight of red seaweed. The average molecular mass of the SP1 and SP2 was estimated about $1.84{\times}10^3$ and $1.42{\times}10^3kDa$, respectively, by size-fractionation High-Performance Liquid Chromatography (HPLC). From the High-Performance Anion-Exchange Chromatography-Pulsed Amperometric Detection (HPAEC-PAD) analysis, the main monosaccharide was galactose with glucose and fucose as minor components. The sulfate content of SP2 (40.4%) was slightly higher than that of SP1 (33.8%). The FT-IR spectra also showed characteristic band of carrageenan-like sulfated polysaccharides. Taken together the SPs are thought to be carrageenan-like sulfated galactan. The polysaccharides (SPs) from I. cordata exhibited weak antitumor activity against PC-3 (prostate cancer), HeLa (cervical cancer), and HT-29 (human colon adenocarcinoma). To our knowledge, this is the first data on biological activity of the Antarctic red seaweed I. cordata.

• The Korea Journal of Herbology
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• v.34 no.6
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• pp.109-115
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• 2019

Objective : Herbal medicinal mixture (JMB) are consisted of Caryophylli Flos, Aucklandiae Radix, and Angelicae Dahuricae Radix. Each of these herbal medicines has studied on anti-aging effect in vitro. So this study was conducted to investigate efficacy and potency of JMB extract on dermal anti-aging and whitening. Methods : The JMB was extracted at room temperature by 80% ethanol. Collagenase and elastase inhibition activity in JMB ethanol extract were determined at 10, 50, 100, 500, 1000 mg/ml concentrations by colorimetric method. The toxic range of JMB ethanol extract was evaluated using MTT assay. Also, The inhibitory effect of JMB ethanol extract on tyrosinase activity and melanin contents in mouse melanoma cell line (B16F10 cell) was identified at 50, 100, 200 ㎍/㎖ levels by spectrometric assay. In each analysis, EGCG (epigallocatechin gallate) and Kojic acid were used as positive controls, respectively. Results : The elastase and collagenase inhibitory activity of JMB ethanol extract increased dose dependently. Also, The MTT assay showed that JMB, up to 400 ㎍/㎖ concentration, exhibited no toxic effect to the B16F10 cell. And following the JMB ethanol extract treat, cellular melanin contents and tyrosinase activity were dose-dependently decreased compared to those of control. Conclusion : These results suggest that JMB ethanol extract has effects to inhibitory activity on dermal wrinkle enzyme and melanogenesis. Therefore, JMB has applicable benefits for development of materials or products to have whitening and anti-aging functions on skin.

• Applied Chemistry for Engineering
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• v.26 no.3
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• pp.351-355
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• 2015

$Pd/TiO_2$ catalysts for aerobic benzyl alcohol oxidation were synthesized and eight different room temperature ionic liquids were used to control the palladium properties as active sites. $Pd/TiO_2$ particles were also calcined at 300, 400 and $500^{\circ}C$ to obtain an optimum catalyst. As the calcination temperature increased, the surface area and pore volume of catalyst decreased, but negligible changes were observed for the pore size of catalyst. However, the structural properties of catalyst varied with respect to the type of ionic liquids. Under identical reaction conditions, different catalytic activities were obtained depending upon the calcination temperature and type of ionic liquids. Mostly, the catalyst calcined at $400^{\circ}C$ showed higher catalytic activity than those at other temperatures. However, the catalyst prepared with 1-octyl-3-methylimidazolium hexafluorophosphate and 1-octyl-3-methylimidazolium trifluoromethanesulfonate showed good catalytic performance after calcination at $300^{\circ}C$. Among the catalyst, $Pd/TiO_2$ prepared with 1-octyl-3-methylimidazolium tetrafluoroborate and calcined at $400^{\circ}C$ showed the highest catalytic activity.