• Educational Technology International
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• v.11 no.1
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• pp.27-46
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• 2010

The purpose of this paper is to apply the newly developed SICAT teaching and learning model to the actual scene of teaching and learning and draw a point of discussion for utilizing teaching and learning model, by uncovering the satisfaction of students and the inhibiting/facilitating elements when using the model. SICAT(Scientific Inquiry and Creative Activity with Technology; from here on SICAT), a teaching and learning model custom-built for engineering education, was developed, as more and more people paid attention to the demand for creative engineers. It was developed from the basis of PBL(Problem Based Learning), includes three sub-types which can be applied to the actual theory, design, and experimentation fields within engineering education. The three sub-types, which are ARDA(Analysis-Reasoning Activity & Discussion-Argumentation Activity), CoCD (Collaboration Activity & Capstone Design Activity), and ReSh(Reflection Activity & Sharing Activity), respectively support deductive and argumentation activities, creative design and collaboration activities, and retrospection and sharing activities. However, no research has been conducted to investigate whether or not there are inhibiting or facilitating elements in the application procedure, or what the rate of satisfaction for students is, when applying the SICAT model, which was newly developed to innovate existing engineering education, to the actual site of teaching and learning. Therefore, this research applied three types of SICAT teaching and learning models to the theory, design, and experimentation classes at the department of materials science and engineering at Hanyang University for eight weeks. After application, the students, teachers and tutors were surveyed and interviewed, and then the results analyzed in order to uncover inhibiting/facilitating elements and the rate of satisfaction. The satisfaction rate of students from the SICAT teaching and learning model was 3.78(in a perfect score of 5: The A type-3.65, The C type-3.80, The R type-3.90), and inhibiting/facilitating elements were drawn from the aspects of learning activities, support system. In conclusion, they can be contributed for implications of SICAT teaching and learning model universal use at engineering education in University.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.6
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• pp.1135-1139
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• 1997

Major factors inhibiting nonenzymatic browning in stored ginger paste were investigated using aqueous model systems with temperature, water activity, pH and sulfur compounds. Browning index and total gingerols were measured during storage. The rate of nonenzymatic browning reactions showed a strong depencence on temperature and pH and a negligible influence on water activity. It was also reduced by the addition of 0.04% N-actyl-L-cysteine(NAcCys), effectively. Activation energies for aqueous ginger model systems with and without 0.04% NAcCys were 29.0 and 25.8kcal/mole, respectively.

• Corrosion Science and Technology
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• v.20 no.3
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• pp.129-142
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• 2021

Effects of corrosion inhibitors (i.e., sodium nitrite, sodium hexametaphosphate, trimethylamine (TEA), sugar, and urea) on the corrosion resistance of carbon steel in CaCl₂ solution were investigated. The test solution was designed with response surface methodology of design of experiments (DOE) in the range of 0 ~ 50 ppm for NaNO₂, 0 ~ 200 ppm for (NaPO₃)₆, 0 ~ 2000 ppm for TEA, 0 ~ 3000 ppm for sugar, 0 ~ 200 ppm for urea with 3 wt% CaCl₂. The corrosion potential and the corrosion rate were measured with potentiodynamic polarization tests and analyzed statistically to find main effects of inhibitor concentrations and interactions between them. As a result, hexametaphosphate was the most effective compound in reducing the corrosion rate. Sugar also reduced the corrosion rate significantly possibly because it covered the surface effectively with a high molecular weight. The inhibiting action of sugar was found to be enhanced by adding trimethylamine into the solution. Nevertheless, trimethylamine did not appear to be effective in inhibiting corrosion by itself. However, urea and sodium nitrite showed almost no inhibition on corrosion resistance of steel.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.4
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• pp.583-592
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• 2001

This study was undertaken to evaluate the clinical effect of inhibiting plaque formation of Lactococcus lactis 1370, a acid producing bacterium residing in the mouth. 30 children were asked to use 10ml of control mouth-wash and mouthwash containing Lactococcus lactis 1370. The plaque index and plaque area rate at 24h and 48h after the use of the mouthwashes were measured. And the number of Lactococcus lactis 1370 was counted at 1h, 3h, and 6h in the mouth. The results are as follow. 1. The mean plaque index at 24h after the use of the control mouthwash and the mouthwash containing Lactococcus lactis 1370 were 2.43 and 2.06, respectively. The inhibiting rate of plaque formation was 15% (P<0.05). 2. The mean plaque index at 48h after the use of the control mouthwash and the mouthwash containing Lactococcus lactis 1370 were 2.95 and 2.17, respectively. The inhibiting rate of plaque formation was 26%, showing more decrease than at 24h(P<0.05). 3. The mean plaque area rate at 24h after the use of the control mouthwash and the mouthwash containing Lactococcus lactis 1370 were 21.2% and 15.6%, respectively. The inhibiting rate of plaque formation was 26% (P<0.05). 4. The mean plaque area rate at 48h after the use of the control mouthwash and the mouthwash containing Lactococcus lactis 1370 were 33.0% and 17.8%, respectively. The inhibiting rate of plaque formation was 46% (P<0.05). 5. The number of Lactococcus lactis 1370 in the mouth decreased significantly from mouthwashing to 3h, but increased slightly between 3h and 6h. As seen with the above results, we think that using the mouth wash with Lactococcus lactis 1370 would prevent the formation of plaque in the mouth and can be an effective method to prevent dental caries and periodontal disease.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1999.03a
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• pp.243-248
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• 1999

There is substantial evidence that anatomical connections and functional interactions exist between vestibular and autonomic systems. Heart rate variability (HRV) including mean, standard deviation, coefficient of variation (CV), power spectrum was analyzed for evaluation of the physiological role of the vestibular system on control of heart rate in rabbits. In anesthetized rabbits, electrical stimulation of the vagus nerve decreased heart rate and decreased LF/HF by increasing HF. On the cervical sympathetic nerve increased heart rate and increased LF/HF by increasing LF. Atropine, cholinergic blocker, increased heart rate and increased LF/HF by reducing HF, and propranolol, ${\beta}$-adrenergic blocker, decreased heart rate and decreased LF/HF by reducing LF> In unanesthetized rabbits, stimulation of the vestibular system induced by rotation or caloric increased heart rate and increased LF/HF by increasing LF> Also electrical stimulation of the vestibular nerve produced the same of effects as rotation or caloric in anesthetized rabbits. These results suggest that Stimulation of the vestibular system increased heart rate not by inhibiting the parasympathetic nerve but by activating the sympathetic nerve.

• Journal of the korean academy of Pediatric Dentistry
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• v.11 no.1
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• pp.151-157
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• 1984

The purpose of this study was to compare the growth-inhibiting effect of sodium fluoride and stannous fluoride on a cariogenic strain of Streptococcus mutans exposed to the different concentration of $SnF_2$ and NaF The result were as follows: 1. The growth rate of the Streptococcus mutans was unaffected by 75 ppmF, slowed by 150 ppmF, and immediately arrested by 300 or 600 ppmF where increments of NaF were added to actively growing 12-hour broth culture. 2. $SnF_2$ slowed the growth rate at 75 ppmF, was to bactericidal initially at 150 and 300 ppmF, and was to totally bactercidal at 600 ppmF. 3. $SnF_2$ has been shown to be more effective than NaF in inhibiting the growth activity of Streptococcus mutans. 4. The inhibitory effect of fluoride compounds on the growth of Streptococcus mutans was increased in the decreased pH at concentration of 600 ppmF.

• Biomedical Science Letters
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• v.18 no.4
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• pp.420-427
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• 2012

Sprague-Dawley (SD) rats were orally administered with NG-nitro-L-arginine methyl ester (L-NAME), which inhibits or blocks the production of nitric oxide from L-arginine in vascular endothelial cells and vessel tissue. We examined the effects of nitric oxide on some physiological changes such as blood pressure and heart rate, and confirms the apoptosis induced by the suppressed nitric oxide activity in the kidney. This study was performed to investigate correlation between the activities of nitric oxide and apoptosis by immunohistochemical changes of apoptotic control proteins with regulated chronic inhibition of nitric oxide. In the kidney from L-NAME-treated group, immunohistochemical reaction to the antigens of apoptosis inhibiting proteins such as bcl-2 and bcl-xL, exhibited a time-dependent reduction. The expression of apoptosis-inhibiting proteins such as bax and p53 increased expression in proportion to the duration of treatment. The most sensitive apoptosis regulating proteins to L-NAME were p53 in stimulation and bcl-2 in inhibition, respectively.

• Journal of Plant Biology
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• v.25 no.1
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• pp.21-36
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• 1982

The activity of photosystem II in isolated chloroplast form the leaves of Sedum sarmentosum was measured. The photoreduction rate of DCPIP by photosystem II showed the circadian rhythm with a peak at near midday sample for a continuing fine day and at near afternoon between nidday and sunset sample for a continuing cloudy day in summer. The optimum light intensity of photoreduction by photosystem II in the chloroplast preparation was about 5~9$\times$$10^4$ lux. The saturated light intensity was over 9$\times$$10^1$lux. Photosystem II activity was inhibited by even the lowest concentration of lead. When Pi and ATP of the same concentration as Pb were added to the reaction mixture containing Tris buffer lacking of Pi prior to Pb incubation, photosystem II activity was protected from Pb-inhibiting effect by the pretreament of Pi and ATP. It was assumed that Pb inhibiiton was probably due to one, P-depriving by the precipitates of $Pb_3$ $($Pb_4$)_2$ in the reaction mixture and the other, partially Pb-combing with Pi groups of the active site of photosystem II.

• The Korean Journal of Pharmacology
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• v.11 no.2
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• pp.1-8
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• 1975

This study was carried out to observe the effect of testosterone on carbonic anhydrase inhibiting action of acetazolamide. Carbonic anhydrase activities in the kidneys of mice were measured by Philpot and Philpot method(1936) at 30, 90 and 150 minutes after intravenous administration of saline(0.5 ml/10 g) or acetazolamide (0.25 mg/10 g) in mice pretreated with testosterone (0.1 mg/10 g). The changes in volume and pH of urine as well as those in urinary electrolytes, such as $Na^+,\;K^+\;and\;Cl^-$ were measured at 15 minutes interval for 150 minutes in the rabbit pretreated with double administrations of testosterone(10 mg/kg), 1 hour and 18 hours, prior to the administration of acetazolamide (10 mg/kg). The results were as follows: 1. Carbonic anhydrase activities in the kidneys of mice of testosterone-pretreated groups were significantly higher than those of acetazolamide-treated group at 30 minutes. No significant changes of carbonic anhydrase activities were observed in testosterone-pretreated groups compared with saline-treated groups. 2. Combined administrations of acetazolamide and testosterone exhibited higher carbonic anhydrase activity than those group of acetazolamide alone in the kidney of mice through observed period of 150 minutes. 3. There were no significant changes in the excretion rate of urine and urinary electrolytes in the group of rabbits with testosterone administerone alone. Urine volume as well as $Na^+\;and\;Cl^-$ excretion rates in the combined treated group of acetazolamide and testosterone were significantly lower than that of acetazolamide group throughout experimental period except 15 minutes after drug administration at the time transient increase was shown. 4. Generally lower $K^+$ excretion rate was observed in the combined treated group of acetazolamide and testosterone compared with the single acetazolamide-treated group and the testosterone-pretreated group shows lowest excretion rate of potassium.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.10
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• pp.4369-4376
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• 2015

Background: To investigate in-vitro antagonistic effect of low-dose liquiritigenin on gemcitabine-induced capillary leak syndrome (CLS) in pancreatic adenocarcinoma via inhibiting reactive oxygen species (ROS)-mediated signalling pathways. Materials and Methods: Human pancreatic adenocarcinoma Panc-1 cells and human umbilical vein endothelial cells (HUVECs) were pre-treated using low-dose liquiritigenin for 24 h, then added into gemcitabine and incubated for 48 h. Cell viability, apoptosis rate and ROS levels of Panc-1 cells and HUVECs were respectively detected through methylthiazolyldiphenyl-tetrazoliumbromide (MTT) and flow cytometry. For HUVECs, transendothelial electrical resistance (TEER) and transcellular and paracellular leak were measured using transwell assays, then poly (ADP-ribose) polymerase 1 (PARP-1) and metal matrix proteinase-9 (MMP9) activity were assayed via kits, mRNA expressions of p53 and Rac-1 were determined through quantitative polymerase chain reaction (qPCR); The expressions of intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and PARP-1 were measured via western blotting. Results: Low-dose liquiritigenin exerted no effect on gemcitabine-induced changes of cell viability, apoptosis rate and ROS levels in Panc-1 cells, but for HUVECs, liquiritigenin ($3{\mu}M$) could remarkably elevate gemcitabine-induced decrease of cell viability, transepithelial electrical resistance (TEER), pro-MMP9 level and expression of ICAM-1 and VCAM-1 (p<0.01). Meanwhile, it could also significantly decrease gemcitabine-induced increase of transcellular and paracellular leak, ROS level, PARP-1 activity, Act-MMP9 level, mRNA expressions of p53 and Rac-1, expression of PARP-1 and apoptosis rate (p<0.01). Conclusions: Low-dose liquiritigenin exerts an antagonistic effect on gemcitabine-induced leak across HUVECs via inhibiting ROS-mediated signalling pathways, but without affecting gemcitabine-induced Panc-1 cell apoptosis. Therefore, low-dose liquiritigenin might be beneficial to prevent the occurrence of gemcitabine-induced CLS in pancreatic adenocarcinoma.