• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.1
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• pp.739-744
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• 2020

This study evaluates the erosive potential and effects of mixed alcohols by analyzing the pH, titratable acidity, and fluorescence loss degree (△F). Following alcohol groups were investigated: Soju, Calamansi+soju, Yakult+soju, Cola+soju, and Energy drink+soju. The ratio of soju:beverage in the alcohol mixtures was 7:3. Ed. Notes: The sentence lacks clarity. Please review if the edit correctly portrays the meaning. If not, please revise appropriately. Measurement of the pH and titratable acidity (the amount of 1M NaoH solution required to raise to pH 5.5 (TA5.5) and 7.0 (TA7.0)) of alcohols was achieved by stirring with pH meter. The erosive effect of the alcohol mixtures on bovine tooth (△F) after 1, 2, 4, and 6 hours exposure were analyzed by quantitative light-induced fluorescence (QLF-D). All the mixed alcohols in this study showed an acidic pH, lower than 4.5. The average pH of mixed alcohols was 3.17 ± 0.50 whereas the pH of Soju was 8.6 ± 0.01. The TA5.5 and TA7.0 values of the mixed alcohols were 0.5~18 and 0.5~23.5, respectively. △F of the three tested mixed alcohol groups (except yakult+soju group) were observed to increase in a time-dependent manner. The calamansi mixed alcohol had the highest acidity potential and erosive effect among the tested groups. Taken together, the results indicate that the mixed alcohols have a strong erosive effect and potential on dental enamel.

• Journal of Veterinary Clinics
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• v.24 no.3
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• pp.320-324
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• 2007

This study was undertaken to assess the antinociceptive effect of Korean bee venom (BV) in mice. Korean BV was collected using BV collector devices in which an electrical impulse is used to stimulate the worker bee (Apis mellifera L.) to sting and release venom. After collection, whole BV was evaporated until dry using the BV collector. Experiments were performed on male ICR mice (weighing $30{\sim}35g$, 6 weeks old). Mice were divided into 4 groups, each comprising 8 mice. BV was diluted and amounts of 6 mg/kg body weight (BW), 0.6 mg/kg BW and 0.06 mg/kg BW were tested. BV was subcutaneously injected to produce an antinociceptive effect and the antinociceptive efficacy was evaluated using a writhing test in mice. Intraperitoneal injection of acetic acid produced a tonic pain behavior, first observed at 3 to 9 min post-injection. This writhing response peaked at 20 min post-acetic acid injection, and then declined until it was undetectable at 60 min post-injection. The time elapse between the administration of acetic acid and the first observed pain behaviors indicated a dose-dependent suppressive effect. These results suggest that Korean BV may be used to achieve an antinociceptive effect for use in medical therapies.

• Journal of Ginseng Research
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• v.43 no.4
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• pp.676-683
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• 2019

Background: Korean Red Ginseng (KRG) is widely used for strengthening the immune system and fighting fatigue, especially in people with deficiency syndrome. However, there is concern that the long-term application or a high dose of KRG can cause "fireness" (上火 in Chinese) because of its "dryness" (燥性 in Chinese). The aim of this study was to assess the safety and efficacy of a 4-week treatment with KRG in participants with deficiency syndrome. Methods: This was a 4-week, randomized, double-blind, placebo-controlled clinical trial. A total of 180 Chinese participants were randomly allocated to three groups: placebo control group, participants were given a placebo, 3.6 g/d; KRG 1.8 g and 3.6 g groups. The primary outcomes were the changes in fireness and safety evaluation (adverse events, laboratory tests, and electrocardiogram). The secondary outcomes were the efficacy of KRG on fatigue, which include the following: traditional Chinese medicine (TCM) symptom scale and fatigue self-assessment scale. Results: Of the 180 patients, 174 completed the full study. After 4 weeks of KRG treatment, the Fire-heat symptoms score including Excess fire-heat score and Deficient fire-heat score showed no significant change as compared with placebo treatment, and no clinically significant changes in any safety parameter were observed. Based on the TCM syndrome score and fatigue self-assessment score, TCM symptoms and fatigue were greatly improved after treatment with KRG, which showed a dose- and time-dependent effect. The total effective rate was also significantly increased in the KRG groups. Conclusion: Our study revealed that KRG has a potent antifatigue effect without significant adverse effects in people with deficiency syndrome. Although a larger sample size and longer treatment may be required for a more definite conclusion, this clinical trial is the first to disprove the common conception of "fireness" related to KRG.

• Analyses & Alternatives
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• v.6 no.2
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• pp.155-183
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• 2022

The purpose of this study is to econometrically analyze the negative impact of the May 18 Democratic Uprising on the Gwangju/Jeonnam regionional economy using the Synthetic Control Method (SCM). The SCM SCM is a methodology similar to the difference-in-difference(DID) method of microeconometrics. It is applied to macroeconomic variables such as country, region, etc. to estimate the causal relationship between specific events and the dependent variable. In this study, as of 1980, local tax revenue data of metropolitan local governments were used as a proxy variable for the economy of the region, and the impact of the May 18 Democratic Uprising on the economy of Gwangju/Jeonnam region was analyzed through various socio-economic indicators. In this study, data were used to analyze from 1971 to 2000, and as a result of empirical analysis, local tax revenues in Gwangju/Jeonnam area were less collected than normal routes up to 17%. In addition, the significance of this analysis was confirmed through in-time placebo effect analysis and in-space placebo effect analysis, which are methods of analyzing the robustness of the control group synthesis method.

• Magazine of the Korean Society of Agricultural Engineers
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• v.13 no.1
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• pp.2162-2176
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• 1971

From the ancient times our forefathers settled down in this peninsular and cultivated the hills and waste-lands into fields. Instead of fertilizing the lands they moved to find other fertile lands and lived a feudal life of agriculture and various machines played a main role in the land reclamation. The best method of land clearing, the time and efficiency in the operation and the effect of growing crops should sysematically analized prior to the time of 3rd Five-year Economic Development(1972-1976) in order to cultivated 210,000 ha of waste-land or the modernization of our country. The present study was investigated to find out a new working-system of mechanical land clearing and development of fertile soil. The results are as follows: 1) The land reclamation in natural slope is much more encourageable in land clearing and farming when the slope is below ten grades than bench terrace. 2) Weeds were mixed with soil in the land clearing work in order to supply organic materials and to make soil swollen instead of burning of just removing. 3) The equipments such as bulldozers, harrows, power tillers and so on should be prepared in order to do a systematic work in the land clearing. 4) The work of pulling-up roots is dependent upon the forms of roots spreading under the ground. The work of the pulling-up the straight roots was most difficult. 5) The land clearing work of the wrinkled style blocks was easy in pulling up roots and in the time of first plowing. The harrowing work could also be simply done. 6) The amount of soil carried was $240m^3/10a$, 15.6% increased amount from the standard block, while the required time of clearing work was 2 hours 15 minutes 45 seconds/10a, the one third of time required for the standard block. 7) The time disc harrowing work increased 50%, or 15 minutes/10a compared to the harrowing work required in the cultivated soil. 8) The time of rotary tilling increased 2.4 times or 1 hour 47 minutes 43 seconds/10a compared to the time required in the cultivated soil. 9) The reclamed land should be fertilized according to the soil quality, especially added fertilizer should be more than 1,200kg/10a, limes 20kg/10a. In order to produce added fertilizer grass fields should be needed. 10) The experiment of pasture growing is now progressing and therefore the effect of land clearing and the degree of developed soil will be investigated before long.

• The Korean Journal of Physiology and Pharmacology
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• v.18 no.5
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• pp.431-439
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• 2014

The aim of the present study was to investigate whether ginsenoside-Rb2 (Rb2) can affect the secretion of catecholamines (CA) in the perfused model of the rat adrenal medulla. Rb2 ($3{\sim}30{\mu}M$), perfused into an adrenal vein for 90 min, inhibited ACh (5.32 mM)-evoked CA secretory response in a dose- and time-dependent fashion. Rb2 ($10{\mu}M$) also time-dependently inhibited the CA secretion evoked by DMPP ($100{\mu}M$, a selective neuronal nicotinic receptor agonist) and high $K^+$ (56 mM, a direct membrane depolarizer). Rb2 itself did not affect basal CA secretion (data not shown). Also, in the presence of Rb2 ($50{\mu}g/mL$), the secretory responses of CA evoked by veratridine (a selective $Na^+$ channel activator ($50{\mu}M$), Bay-K-8644 (an L-type dihydropyridine $Ca^{2+}$ channel activator, $10{\mu}M$), and cyclopiazonic acid (a cytoplasmic $Ca^{2+}$-ATPase inhibitor, $10{\mu}M$) were significantly reduced, respectively. Interestingly, in the simultaneous presence of Rb2 ($10{\mu}M$) and L-NAME (an inhibitor of NO synthase, $30{\mu}M$), the inhibitory responses of Rb2 on ACh-evoked CA secretory response was considerably recovered to the extent of the corresponding control secretion compared with the inhibitory effect of Rb2-treatment alone. Practically, the level of NO released from adrenal medulla after the treatment of Rb2 ($10{\mu}M$) was greatly elevated compared to the corresponding basal released level. Collectively, these results demonstrate that Rb2 inhibits the CA secretory responses evoked by nicotinic stimulation as well as by direct membrane-depolarization from the isolated perfused rat adrenal medulla. It seems that this inhibitory effect of Rb2 is mediated by inhibiting both the influx of $Ca^{2+}$ and $Na^+$ into the adrenomedullary chromaffin cells and also by suppressing the release of $Ca^{2+}$ from the cytoplasmic calcium store, at least partly through the increased NO production due to the activation of nitric oxide synthase, which is relevant to neuronal nicotinic receptor blockade.

• International Journal of Oral Biology
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• v.37 no.3
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• pp.137-145
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• 2012

Aggregatibacter actinomycetemcomitans is the most important etiologic agent of aggressive periodontitis and can interact with endothelial cells. Monocyte chemoattractant protein-1 (MCP-1) and interleukin-8 (IL-8) are chemokines, playing important roles in periodontal pathogenesis. In our current study, the effects of A. actinomycetemcomitans on the production of MCP-1 and IL-8 by human umbilical vein endothelial cells (HUVEC) were investigated. A. actinomycetemcomitans strongly induced the gene expression and protein release of both MCP-1 and IL-8 in a dose- and time-dependent manner. Dead A. actinomycetemcomitans cells were as effective as live bacteria in this induction. Treatment of HUVEC with cytochalasin D, an inhibitor of endocytosis, did not affect the mRNA up-regulation of MCP-1 and IL-8 by A. actinomycetemcomitans. However, genistein, an inhibitor of protein tyrosine kinases, substantially inhibited the MCP-1 and IL-8 production by A. actinomycetemcomitans, whereas pharmacological inhibition of each of three members of mitogen-activated protein (MAP) kinase family had little effect. Furthermore, gel shift assays showed that A. actinomycetemcomitans induces a biphasic activation (early at 1-2 h and late at 8-16 h) of nuclear factor-${\kappa}B$ (NF-${\kappa}B$) and an early brief activation (0.5-2 h) of activator protein-1 (AP-1). Activation of canonical NF-${\kappa}B$ pathway ($I{\kappa}B$ kinase activation and $I{\kappa}B-{\alpha}$ degradation) was also demonstrated in these experiments. Although lipopolysaccharide from A. actinomycetemcomitans also induced NF-${\kappa}B$ activation, this activation profile over time differed from that of live A. actinomycetemcomitans. These results suggest that the expression of MCP-1 and IL-8 is potently increased by A. actinomycetemcomitans in endothelial cells, and that the viability of A. actinomycetemcomitans and bacterial internalization are not required for this effect, whereas the activation of protein tyrosine kinase(s), NF-${\kappa}B$, and AP-1 appears to play important roles. The secretion of high levels of MCP-1 and IL-8 resulting from interactions of A. actinomycetemcomitans with endothelial cells may thus contribute to the pathogenesis of aggressive periodontitis.

• Journal of Life Science
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• v.25 no.10
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• pp.1098-1102
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• 2015

FABPpm (plasma membrane-bound fatty acid binding protein ) is highly expressed in skeletal muscle. The principal role of this protein is modulating fatty acid uptake and metabolism. The influence of insulin-like growth factor-I (IGF-I), which is a major regulator of skeletal muscle cells, on FABPpm in skeletal muscle cells has not been investigated. To determine the effect of IGF-I on the expression of FABPpm, differentiated C2C12 murine skeletal muscle cells were treated with 20 ng/ml of IGF-I for different times. IGF-I increased the expression of FABPpm in a time-dependent manner. The mRNA level of FABPpm was measured by real-time quantitative PCR to determine whether the IGF-1-induced induction of FABPpm was regulated pretranslationally. The IGF-I treatment resulted in very rapid induction of the FABPpm mRNA transcript in the C2C12 myotubes. After 24 and 48 hr of the IGF-I treatment, FABPpm mRNA increased 130 and 179%, respectively. The increase in the protein expression returned to control levels after 72 hr of the IGF-I treatment, suggesting that IGF-1 regulated the FABPpm gene pretranslationally in skeletal muscle cells. This is the first evidence that IGF-I has a modulatory effect on the expression of FABPpm. In conclusion, IGF-I induced rapid transcriptional modification of the FABPpm gene in C2C12 skeletal muscle cells and exerted modulatory effects on FABPpm.

• The Korean Journal of Physiology
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• v.26 no.2
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• pp.113-122
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• 1992

It is well known that chromaffin cells of adrenal medulla secrete catecholamine in response to sympathetic nerve activation and the influx of $Ca^{2+}$ through the voltage dependent $Ca^{2+}$ channels (VDCC) in the cell membrane do a major role in this secretory process. In this study, we explored the effect of divalent cations on VDCC of rat chromaffin cells. Rat (Sprague-Dawley rat, 150-250 gm) chromaffin cells were isolated and cultured. Standard giga seal, whole cell recording techniques were employed to study $Ca^{2+}$ current with external and internal solutions that could effectively isolate VDCC currents $(NMG\;in\;external\;and\;TEA\;and\;Cs^{2+}\;in\;internal\;solution)$. The voltage dependence and the inactivation time course of VDCC in our cells were identical to those of bovine chromaffin cells. A persistent inward current was first activated by depolarizing step pulse from the holding potential (H.P.) of -80 mV to -40 mV, increased to maximum amplitude at around +10 mV, and became smaller with progressively higher depolarizing pulses to reverse at around +60 mV. The inactivation time constant $(\tau)$, fitted from the long duration test potential (2 sec) was $1295.2{\pm}126.8$ msec $(n=20,\;1\;day\;of\;culture,\;mean\;{\pm}S.E.M.)$ and the kinetic parameters were not altered along the culture duration. Nicardipine $(10\;{\mu}M)$ blocked the current almost completely. Among treated divalent cations such as $Cd^{2+},\;Co^{2+},\;Ni^{2+},\;Zn^{2+}\;and\;,Mn^{2+},\;Cd^{2+}$ was the most potent blocker on VDCC. When the depolarizing step pulse from -80 mV to 10 mV was applied, the equilibrium dissociation constant $(K_d)$ of $Cd^{2+}\;was\;39\;{\mu}M,\;K_d\;of\;Co^{2+}\;was\;100\;{\mu}M\;and\;K_d\;of\;Ni^{2+}];was];780{\mu}M.$ The principal findings of this study are as follows. First, the majority of $Ca^{2+}$ channels in rat chromaffin cells are well classified to L-type $Ca^{2+}$ channel in the view of kinetics and pharmacology. Second, all divalent cations tested could block the $Ca^{2+}$ current and the most potent blocker among the tested was $Cd^{2+}$.

• Journal of Energy Engineering
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• v.18 no.1
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• pp.56-62
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• 2009

With weld metal of X65 steel, hydrogen was charged by electro-chemical method and mechanical behavior such as strength was measured by the small punch test. The weld metal was more sensitive to hydrogen charging than the case of base metal. The small punch (SP) strength was decreased as the hydrogen contents increased. Magnitude of strength decrease was dependent on current density, temperature, charging time. Current density and charging time have significant effect on the mechanical properties but temperature of electrolyte has limited effect. Fractured surfaces of the tested specimens were observed by SEM (scanning electron microscope). In the hydrogen charged specimens cleavage fracture were observed, which is consistent with the SP test results. Since the testing procedure for studying hydrogen embrittlement proposed in this study has shown good reproducibility of test results, the proposed method can be assumed to be a reliable test procedure. Using the electrochemical charging and the small punch test, the change of SP strength for X65 weld metal due to hydrogen embritlement could be evaluated sensitively.