• The Korean Journal of Physiology
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• v.18 no.1
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• pp.19-35
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• 1984

Since the first report of Drury and $Szent-Gy{\ddot{o}}rgyi$ in 1929, the inhibitory influences of adenosine on the heart have repeatedly been described by many investigators. These studies have shown that adenosine and adenine nucleotides have overall depressant effects, similar to those of acetylcholine. Heart beats become slow and weak. It is also well known that adenosine is a potent endogenous coronary vasodilator. Many investigations on the working mechanisms of adenosine have been focused mainly on the effects of the coronary blood flow. However, the cellular mechanisms underlying the inhibitory action of adenosine on sinus node are not well understood yet. Thus, this study was undertaken to examine the behavior of rabbit SA node under influence of adenosine. In these series of experiments three kinds of preparations were used: whole atrial pair, left atrial strip, and isolated SA node preparations. The electrical activity of SA node was recorded with conventional glass microelectrodes 30 to 50 $M{\Omega}$. The preparations were superfused with bicarbonate-buffered Tyrode solution of pH 7.35 and aerated with a gas mixture of $3%\;CO_2-97%\;O_2$ at $35^{\circ}C$. In whole atrial pair, adenosine suppressed sinoatrial rhythm in a dose-dependent manner. Effect of adenosine on atrial rate appeared at the concentration of $10^{-5}M$ and was enhanced in parallel with the increase in adenosine concentration. Inhibitory action of adenosine on pacemaker activity was more prominent in the preparation pretreated with norepinephrine, which can steepen the slope of pacemaker potential by increasing permeability of $Ca^{+2}$. Calcium ions in perfusate slowly produced a marked change in sinoatrial rhythm. Elevation of the calcium concentration from 0.3 to 8 mM increased the atrial rate from 132 to 174 beats/min, but over 10 mM $Ca^{+2}$ decreased. The inhibitory effect of adenosine on sinoatrial rhythm developed very rapidly. Atrial rate was recovered promptly from the adenosine-induced suppression by the addition of norepinephrine, but extra $Ca^{+2}$ was less suitable to restore the suppression of atrial rate. Adenosine suppressed also atrial contractility in the same dosage range that restricted pacemaker activity, even in the reserpinized preparation. In isolated SA node preparation, spontaneous firing rate of SA node at $35^{\circ}C$(mean{\pm}SEM, n=16) was $154{\pm}3.3\;beats/min. The parameters of action potentials were: maximum diastolic potential(MDP), $-73{\pm}1.7\;mV: overshoot(OS), $9{\pm}1.4\;mV: slope of pacemaker potential(SPP), $94{\pm}3.0\;mV/sec. Adenosine suppressed the firing rate of SA node in a dose-dependent manner. This inhibitory effect appeared at the concentration of $10^{-6}M$ and was in parallel with the increase in adenosine concentration. Changes in action potential by adenosine were dose-dependent increase of MDP and decrease of SPP until $10^{-4}M$. Above this concentration, however, the amplitude of action potential decreased markedly due to the simultaneous decrease of both MDP and OS. All these effects of adenosine were not affected by pretreatment of atropine and propranolol. Lowering extra $Ca^{2+}$ irom 2 mM to 0.3 mM resulted in a marked decrease of OS and SPP, but almost no change of MDP. However, increase of perfusate $Ca^{2+}$ from 2 mM to 6 or 8 mM produced a prominent decrease of MDP and a slight increase of OS and SPP. Dipyridamole(DPM), which is known to block the adenosine transport across the cell membrane, definately potentiated the action of adenosine. The results of this experiment suggest that adenosine suppressed pacemaker activity and atrial contractility simultaneously and directly, by decreasing $Ca^{2+}-permeability$ of nodal and atrial cell membranes.

• Journal of dental hygiene science
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• v.14 no.1
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• pp.59-66
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• 2014

The purpose of this study was to study of utilization of dental high school and according to the pain experienced dental fear and anxiety. This survey was conducted on 370 high school students in Suwon from November 21 to 23, 2011. A total of 352 questionnaires were collected and analyzed. The collected data was analyzed using the statistical package SPSS 15.0 using frequency, mean and standard deviation analysis, t-test, one-way ANOVA, Duncan's test correlation analysis and Stepwise multiple regression analysis. The results state that students feel fear and anxiety were feeling anesthetic needle ($3.19{\pm}1.43$), seeing anesthetic needle ($3.14{\pm}1.44$). We found that students feel more rear and anxiety from caries treatment than scaling. It influence that having dental fear with past dental pain experienced during dental treatment and also hearing dental treatment of pain from their family and friends. We found out that there are some influencing factors on dental fear and anxiety, gender, oral health condition, smoking, pain experienced during dental treatment. We need to care dental fear and anxiety continuously and have prevention program. We have to try understanding students have dental fear and anxiety. So it's better they have good experience visiting dental clinic. We should develop the system and specially treat well while they have dental treatment with anesthesia and some sharp instruments.

• Korean Journal of Soil Science and Fertilizer
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• v.14 no.1
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• pp.37-43
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• 1981

This pot experiment was conducted to find out the optimal fertilization ratio of the cations(K: Ca: Mg) in various soil conditions. Soil samples were collected from uncultivated mountains and hills where development for grass lands is under consideration. The optimum ratios were computed by the Homes systematic variation technique. The results were summarized as follows : 1. The optimum fertilization ratios of the cations (K : Ca : Mg) for the high yields of grass-clover mixed sward at various areas were obtained (Table 4) 2. The relatively high optimum fertilization ratios of K in Daegu and Taegwalryong, Ca in Unbong, and Mg in Cheju district gave the high yields of clover in mixed sward. They were positively related to the low contents of the above cations in the soils or the relatively low content ratio comparing with other cations. 3. The yields of clover in mixed sward were seriously affected by the changes in both the fertilization ratio and total concentration of cations comparing to those of the grass yields. As a consequence, total yields, quality, and botanical composition of the mixed sward were also affected. 4. The antagonis among the cations K, Ca, and Mg was known from the point of mineral contents of grass and clover. 5. The equivalent ratio K/(Ca+Mg) or grass was greatly increased by the range of 2.4 and 3.3 in the K-group treatment, which was higher than the critical level 2.2 of grass tetany, otherwise that. of clover by the range of 0.9 and 1.2. Therfore, it may be concluded that if the botanical composition of grass/legume sward is optimum, the incidence of grass tetany can be eliminated.

• Journal of Life Science
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• v.23 no.11
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• pp.1397-1403
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• 2013

Fructus Sophorae, the dried ripe fruit of Styphnolobium japonicum (L.), is an herbal ingredient used in traditional Oriental medicine. This study was carried out to investigate the effects of Fructus Sophorae extracts (FSE) on immune modulation in a murine RAW 264.7 macrophage model. As immune response parameters, the production of prostaglandin $E_2$ ($PGE_2$) and tumor necrotic $factor-{\alpha}$ ($TNF-{\alpha}$) were evaluated. Our data revealed that FSE increased the macrophage activation and the production of $PGE_2$ and $TNF-{\alpha}$, which was consistently correlated with upregulation of cyclooxygenase-2 (COX-2) and $TNF-{\alpha}$ expression at both transcriptional and translational levels. On comparative cytokine protein array, FSE significantly increased several cytokines, which was associated with phosphorylation of mitogen- activated protein kinases (MAPKs), including extracellular signal-regulated kinase (ERK), p38 MAPK and c-Jun N-terminal kinase (JNK), and Akt in RAW 264.7 cells. However, each inhibitor of these molecules attenuated the FSE-induced $PGE_2$ production. These results indicate that FSE activated macrophages through the activation of MAPKs and phosphatidylinositol-3-kinase (PI3K)/Akt signaling pathways in RAW 264.7 macrophages. These findings suggest that FSE may provide a promising source of an immunoenhancing agent.

• Korean Journal of Food Science and Technology
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• v.49 no.4
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• pp.430-437
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• 2017

The protective effect of Pteridium aquilinum on high glucose-induced cytotoxicity was examined in vitro to investigate the relationship between diabetic condition and neuronal dysfunction. The ethyl acetate fraction of P. aquilinum (EFPA), with total phenolic content of 265.08 mg gallic acid equivalent/g, showed higher 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)/2,2-diphenyl-1-picrylhydrazyl radical scavenging activities and lipid peroxidation inhibitory effect than any other fraction. In addition, EFPA showed a significant reduction in the inhibitory effect on ${\alpha}$-glucosidase activity ($IC_{50}$ value=$205.26{\mu}g/mL$) compared to the acarbose positive control. The anti-oxidative effect in PC12 cells, protective effects on high glucose-induced oxidative stress in neuronal cells, and neurotoxicity were measured using 2',7'-dichlorofluorescin diacetate, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazoliumbromide, and lactate dehydrogenase assays, respectively. EFPA showed conspicuous inhibitory effect on cellular reactive oxygen species production and neuronal cell apoptosis. Finally, kaempferol-3-glucoside was identified as the main phenolic compound of EFPA using high performance liquid chromatography.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.21 no.2
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• pp.281-313
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• 1976

To obtain fundamental informations on cotton breeding efficiences for Korea, individual genetic relationships and interrelationships between the agronomic characteristics of Upland cotton were investigated. These experiments were couducted at the Mokpo Branch Station $(34^{\circ}48'N, $ $126^{\circ}23'E$ and altitude of 10m above sea level) from 1969 through 1972. Heterosis, combining ability, dominance and recessive gene action, genetic variance, and phenotypic and genotypic correlation were investigated by $F_1'S$ from an 11-parent partial diallel cross and the segregating $F_2$ and $F_3$ populations of the cross Paymaster times Heujueusseo Trice. The following points resulted from this study, 1. Heteroses for number of bolls per plant and lint yield were significant at 27, 84% and 37.26%, respectively. No other character had significant heteroses. 2. The GCA estimates for all studied characteristics were higher than the SCA estimates. Varieties with high GCA effects were Suwon 1 for earliness, Paymaster and Arijona for high lint percent, and Arijona for long fiber, etc, 3. SCA estimates for lint yield varied widely in crosses with Mokpo 4, Mokpo 6 and Heujueusseo Trice. Those crosses with the highest SCA effects were combinations with large characteristics differences, Example of these crosses are Mokpo 4 times Acala 1517W, Mokpo 4 times D. P. L. and Heujueusseo Trice aud Paymaster. 4. Early-maturing varieties were completely dominant to late-maturing varieties in some combinations while other crosses gave intermediate phenotypes. These results suggest additive genetic action by multi-genes. Heujueusseo Trice, Mokpo 6, and Suwon 1 showed highest degree of dominance for earliness. 5. There were no significant trends for inheritance of weight of boll and 100 seeds weight. 6. Long staple was partially to completely dominant to short staple. Though there were single gene ratios the rate of dominance decreased in the $F_2$ and $F_3$ populations in the cross between the long staple variety Paymaster and the short staple variety Heujueusseo Trice. Diallel cross $F_1$ hybrids showed complicated allelic gene action for staple length. Various dominance degree were shown by varieties. 7. Number of bolls per plant indicated strong over-dominance and small non-allelic additive gene action. 8. Lint Yield was characterized by over-dominance and by multiple non-allelic-gene action. High-yielding varieties were dominant to low-yielding ones. However, the low-yielding variety Heujueusseo Trice showed over-dominance, indicating different reactions according to the varieties and combinations. 9. Broad sense heritability for days to flowering was 34-39% while narrow sense heritability was 11%. Large variations of individual plants caused by Korean climatic conditions cause this situation. Heritability estimates for weight of boll was 30% for broad sense and 22% for narrow sense. 10. Heritability estimates for staple length and lint percent were very high suggesting strong selection effects. 11. Narrow sense heritability estimates for number of bolls per plant was 30% in the diallel cross $F_1$ hybrids and 36% in the $F_2$ population of the special cross. Broad sense heritability was estimated at 67% suggesting that. 12. Heritability estimates for lint yield was low due to high over-dominance in the diallel cross $F_1$ hybrids. Heritability estimates for yield was low in the $F_1$ hybrids but high in the $F_2$ and $F_3$ populations. 13. Phenotypic and genotypic correlations between lint percent and days to flowering and between staple length and days to flowering were high in the $F_1, $ $F_2$ and $F_3$ populations. Late-maturing varieties and individuals had long staple and high lint percent in general. As the correlation between days to flowering and lint yield was extremely low, the two traits were considered independent of each other. Days to flowering and number of bolls per plant were negatively correlated in the $F_3$ population, indicating early-maturing individual plants with many bolls may be readily selected. 14. Phenotypic and genotypic correlations between lint percent and staple length were high in $F_1, $ $F_2$ and $F_3$ populations. Accordingly, long staple varieties were high in lint percent. It was recognized that lint yield and lint percent were positively correlated in the diallel cross $F_1$ hybrids, and lint percent and staple length were positively correlated in the $F_2$ population, indicating that lint percent and staple length affect lint yield. 15. Lint yield was significantly and positively phenotypically correlated with number of bolls per plant in $F_1, $ $F_2$ and $F_3$ populations. A high genotypic correlation was also noted indicating a close genetic relationship. The selection efficiencies for a high-yielding variety can be increased when individual plants with many bolls are selected in later generations. The selection efficiencies for good fiber quality can be enhanced when individuals with long staple and high lint percent are selected in early generations.

• Korean Journal of Organic Agriculture
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• v.18 no.4
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• pp.613-626
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• 2010

Coming with the well-being era, consumer's demand for safe agricultural products is increasing. It is urgent to develop an environment-friendly pear production system. Accordingly, this study was conducted to develop an environment-friendly pear production system by using several environment-friendly agricultural materials which is known to be effective in agricultural production. In the effects of environment-friendly agricultural materials on the soil chemical characteristics in pear orchard, the content of total carbon, organic matter, Ca and Mg increased a little respectively compared with those of 2008, and 2nd treatment showed the highest EC and Mg content in the soil among treatments. The content of leaf N, P and Ca in 2009 decreased compared with those of 2008, while Mg content showed no difference between 2008 and 2009 years. Average pear weight in 2009 was 31g higher than that of 2008 (682g) and 2nd treatment showed the highest pear weight (738g) among treatments. The average sugar content was higher in 2009 (12.6$^{\circ}Bx$) compared with that of 2008 (12.2$^{\circ}Bx$) and the plot of 2nd treatment highest sugar content (12.6$^{\circ}Bx$) among treatments. There were no difference in hunter value of L among treatments, but hunter value of a showed higher 1.62 in 2009 than that of 2008 (3.73). The highest of gumminess and cohesiveness of fruits were obtained from 1st treatment and adhesiveness and chewiness of fruits were obtained from 3rd and 1st treatment respectively. Firmness of fruit increased a little in 2009 compared with that of 2008, while the highest firmness was obtained from 3rd treatment with 1.63kg/5mm$\oint$ among treatments. Phosphate content in the peel of 'Niitaka' pear of fruit skin in 2009 (0.97g/kg) showed 0.06g/kg more content than that of 2008 (0.91g/kg), while the highest content was obtained from 3rd treatment (1.15g/kg). Potassium content in the peel of 'Niitaka' pear in 2009 was 8.20g/kg, which is 0.06g/kg more content than that of 2008 (7.82g/kg) and the highest content was obtained from 1st treatment (8.34g/kg) among treatments. The highest nitrogen content in the flesh of 'Niitaka' pear was obtained from 3rd treatment (4.32mg/g), while it was the lowest in control plot (3.10mg/g). Phosphate content in the flesh of 'Niitaka' pear in 2009 (8.20g/kg) showed 0.06g/kg more content than that of 2008 (7.82g/kg), while the highest content was obtained from 1st treatment (8.34g/kg). There were no difference of the potassium content in the fruit peel of 'Niitaka' pear between years, but 1st treatment showed the highest content (11.81g/kg) among treatments, while the lowest was obtained from the control plot (10.83g/kg).

• Applied Biological Chemistry
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• v.20 no.2
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• pp.205-209
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• 1977

The pool size of plasma glucose, turnover rate and other concerned items for glucose metabolism in normal laying hen were investigated by a single-injection method using $U-C^{14}-glucose$. The 11.6 nCi of pure dose was injected to a hen normally fed through the wing vein. The glucose concentration in plasma sample taken at 5 minutes after injections was 214mgper 100ml. From the plottings of logarithmic standard specific activities of plasma taken from 5 to 120 minutes against the time after injection and from the regresion analysis, metabolic states were determined. The pool size was 1.07g, turnover rate was 0.024 per minute, turnover time was 41 minutes, utilization rate was 26mg/min. (0.83 g/hr/kg B.W. 3/4) and glucose space(extracellular fluid volume) was 25.3 per cent of body weight. The values obtained from. 10-50 minutes samples were similar to those described above, which we from 5-120 minutes samples.

• Journal of Bio-Environment Control
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• v.15 no.3
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• pp.257-263
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• 2006

This experiment was conducted to investigate the optimal media for 'Pechika' ever-bearing strawberry grown in hydroponic culture system in summer highland. Three mixed media (1:1, v/v) of peatmoss with perlite, rice hull, and granular rockwool, and four solution strengths of EC 0.5, 0.75, 1.0 and $1.25 dS{\cdot}m^{-1}$ were tested. Root zone temperature in peatmoss+perlite media was 1 to $3^{\circ}C$ lower than in the other media. The culture medium of mixing to peat moss and perlite was most effective in producing good yield and fruit quality. The culture medium of mixing to peat moss and perlite was the highest about 1,632kg/10a to yield yearly average, but was very undulating 732 kg/10a to yield in 2004 year and 3,013kg/10a in 2003 year. The deformed fruits were increased when the solution strength was increased, especially in EC $1.25dS{\cdot}m^{-1}$. The soluble solids and the acidity content of fruits were increased with higher solution strength regardless of media. The uptake of Ca and Mg was inhibited at higher solution strength, and the uptake of N, P and K was promoted. Therefore, the culture medium of mixing to peat moss and perlite was the most suitable culture medium to product strawberry in summer, because it had the highest yield even though fruit quality among treatments was not significant.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.6
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• pp.747-756
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• 1995

To find out the optimum application method of slow-releasing fertilizer(SRF) and conventional fertilizer(CF) with different fertilization rate under two culture methods[l0-day old seedling machine transplanting(MT) and direct-sowing on dry paddy(DS)] in the south-western region(clay loam soil) of Korea, used were Chosun slow-releasing fertilizer(silicate latex coated fertilizer: N-P$_2$O$_{5}$-K$_2$O =18-12-13) and conventional fertilizer. Plant height and number of tillers with different two culture methods were higher at MT than DS in early growth. The ratio of dry weight in heading stage was higher at CF than SRF in MT than DS and especially, SRF 80% + CF 20% than SRF 100% or CF 100%. Leaf area index (LAI) in heading stage was higher at CF in MT but higher at SRF in DS than their counterparts. Chlorophyll content was higher at SRF than in CF expect for heading stage(HS), especially in DS. It was highest at HS in CF without its difference during maximum tillering stage(MTS) and panicle formation stage(PFS), while highest at PFS in SRF with tendency of gradual increase and decrease before and after PFS, respectively. Heading was delayed 2~3 days at SRF in two cultrue methods and 4~5 days at SRF in DS in comparison with CF in MT with delay of 2 days at DS compared with MT. Culm length was longer at CF in MT and at SRF in DS than their counterparts. Panicle number per m was more at SRF and in DS. Filled grain ratio was higher at CF and in MT. Yield was obtained 101 and 100% at 100% and 80% level of SRF in DS respectively, and 96% at 80% level of CF in MT, compared with conventional application method (516kg /l0a), and increased 2~4% at DS and 0~3% at MT in SRF. Yield was high in order of 100%(SRF) =80%(SRF) + 20%(CF) > 100%(SRF) + 20%(CF) > 80%(SRF) at MT and 80%(SRF) + 20%(CF) =100%(SRF) > 80%(SRF) =100%(SRF) + 20%(CF) at DS.