• Journal of the Korean Society of Earth Science Education
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• v.4 no.2
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• pp.151-165
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• 2011

Following a microgenetic design, this study was analysed the characteristic and the change of classification strategy that appear in college students' classification activity. The 4 tasks were developed for classification activity; a shell as a familiar real things, an animal fossil as a unfamiliar real things, a snow flake as a familiar picture cards and galaxy as a unfamiliar picture card. Achieved study to 6 college students who major in elementary education. Data were collected by interview with subjects, subject's classification schema, investigator's observation of subject's activity, and videotaped that record subject's subject classification process over an extended period of 6 times. Result proved in this study is as following. In the 6 times of the data collection procedures, a strategy F identifying concrete attribution of classification objects and a more detailed strategy X3 combining qualitative, spatial and dimensional attribution were found and more frequently used in both groups of college students which reported a classification process and did not report the process. While discovery and absorption of both a concrete classification strategy and a detailed classification strategy were rapidly developed in the reporting group, they were gradually developed in the non-reporting group. In addition to this, as the data collection procedures were progressing, the college students were familiar with change factors of classification tasks and in the case of pictures the classification strategy showed more desirable changes.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.172-172
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• 2012

Non-thermal plasma has attracted medical researchers, since they showed higher apoptosis rate in cancer cells than normal cells. However, it is hard to conclude general cancer cell specific effect because comparison between normal and cancer cell activities after plasma treatment have not been reported yet. This research proposes a comparison of Dielectric Barrier Discharge (DBD) plasma effect on three normal cells lines and three cancer cells lines. We measured cell number, mitochondria activity (MTS assay) and amount of hydrogen peroxide (H2O2) for three days. The results show that the number of cancer cells decreased more than normal cells following of exposure time. On the other hand, mitochondria activities and amounts of H2O2 increased following of exposure time. In addition, we found that DBD plasma exposure on cell suspension in media and media only illustrated no difference in mitochondria activity, H2O2 quantity, and cell number. Thus, we can confirm higher apoptosis rate in cancer cells which is related to the reactive oxygen species (ROS) generated by DBD plasma. The related molecular mechanisms were investigated further.

• Nuclear Engineering and Technology
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• v.51 no.4
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• pp.1109-1116
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• 2019

It is essential to predict the radioactivity distribution around the reactor cooling system (RCS) during obligatory cyclic operation of AP-1000. A home-developed program CPA-AP1000 is upgraded to predict the response of activated corrosion products (ACPs) in the RCS. The program is written in MATLAB and it uses state of the art MCNP as a subroutine for flux calculations. A pair of cyclic power profiles were superimposed after initial full power operation. The effect of cyclic operation is noticed to be more prominent for in-core surfaces, followed by the primary coolant and out-of-core structures. The results have shown that specific activity trends of $^{56}Mn$ and $^{24}Na$ promptly follow the power variations, whereas, $^{59}Fe$, $^{58}Co$, $^{99}Mo$ and $^{60}Co$ exhibit a sluggish power-following response. The investigations pointed out that promptly power-following response of ACPs in the coolant is vital as an instant radioactivity source during leakage incidents. However, the ACPs with delayed power-following response in the out-of-core components are perceived to cause a long-term activity. The present results are found in good agreement with those for a reference PWR. The results are useful for source term monitoring and optimization of work procedures for an innovative reactor design.

• IMMUNE NETWORK
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• v.5 no.4
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• pp.199-204
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• 2005

Background: ADP-ribosyl pyrophosphatases (ADPRase) has been known to catalyze the hydrolysis of ADP-ribose to ribose-5-phosphate and AMP. The role of ADPRase has been suggested to sanitize the cell by removing potentially toxic ADP-ribose. In this study, we examined the effect of nitric oxide on ADPRase activity in macrophages. Methods: ADPRase activity was measured in NO-inducing J774 cells. For in vitro experiments, recombinant human ADPRase was prepared in bacteria. Results: ADPRase activity was increased by the treatment of exogenous NO generating reagent, sodium nitroprusside (SNP), in J774 cells. The increased ADPRase activity was mediated by the post-translational modification, likely to cause cADP-ribosylation via nitrosylation of cysteine residue on the enzyme. The stimulation with endogeneous NO inducers, $TNF-{\alpha}/IFN-{\gamma}$, also increased ADPRase activity through NO synthesis. Futhermore, ADPRase activity may be mediated by the post-translational modification of ADPRase, ADP-ribosylation. Conclusion: These results indicate that NO synthesized by macrophage activation plays a critical role in the increase in ADPRase activity following ADP-ribose metabolism.

• Restorative Dentistry and Endodontics
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• v.12 no.1
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• pp.77-84
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• 1986

This study was designed to compare the antimicrobial effect of the several root canal cements and to determine the duration of their activity. After Strep. sanguis 9811 was streaked on the surface of BHI agar and Plain agar, PVC tubes filled with root canal cements were applied and cultured for 48 hours, aerobically. Following results were obtained, 1. All of the examined root canal cements had antimicrobial activity with varying degree. 2. The antimicrobial activity of N2 was larger than any other root canal cements. Nogenol and Tubliseal showed the lowest activity. ZOE, AH26, Procosol and PCA cement showed the moderate antimicrobial activity. (P>0.05) 3. At one day after mixing the root canal cements, all of the root canal cements except N2 and PCA cement showed greatly reduced antimicrobial activity. 4. At three days after mixing, PCA cement showed the reduced antimicrobial activity. N2 showed the reduced activity at 7 days after mixing.

• Toxicological Research
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• v.7 no.2
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• pp.165-171
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• 1991

Effects of forced physical exercise on the CCl4 hepatotoxicity were examined in adult female rats. Rats were treated with CCl4 (2 mmol/kg, ip) and introduced into a cylindrical cage rotating at 9 rpm for 20 min/hr for 6 hr. Eighteen hr following the termination of exercise serum sorbitol dehydrogenase (SDH), glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT) activities and glucose-6-phosphatase activity were determined as parameters for hepatotoxicity. Physical exercise inhibited the $CCI_{4-}$induced increases in SDH, GOT, GPT activity, and glucose-6-phosphatase activity were determined as parameters for hepatotoxicity.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.3
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• pp.263-273
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• 1997

The purpose of this study was to evaluate the effects of electrical stimulation on vestibular compensation following ULX in rats. Electrical stimulation (ES) with square pulse ($100{\sim}300uA$, 1.0 ms, 100 Hz) was applied to ampullary portion bilaterally for 6 and 24 hours in rats receiving ULX. After ES, animals that showed the recovery of vestibular symptoms by counting and comparing the number of spontaneous nystagmus were selected for recording resting activity of type I, II neurons in the medial vestibular nuclei (MVN) of the lesioned side. And then the dynamic neuronal activities were recorded during sinusoidal rotation at a frequency of 0.1 Hz and 0.2 Hz. The number of spontaneous nystagmus was significantly different 24 hours (p<0.01, n=10), but not 6 hours after ULX+ES. As reported by others, the great reduction of resting activity only in the type I neurons ipsilateral to lesioned side was observed 6, 24 hours after ULX compared to that of intact labyrinthine animal. However, the significant elevation (p<0.01) of type I and reduction (p<0.01) of type II neuronal activity were seen 24 hours after ULX+ES. Interestingly, gain, expressed as maximum neuronal activity(spikes/sec)/maximum rotational velocity(deg/sec), was increased in type I cells and decreased in type II cells 24 hours after ULX+ES in response to sinusoidal rotation at frequencies of both 0.1 Hz and 0.2 Hz. This result suggests that accompanying the behavioral recovery, the electrical stimulation after ULX has beneficial effects on vestibular compensation, especially static symptoms (spontaneous nystagmus), by enhancing resting activity of type I neurons and reducing that of type II neurons.

• The Korean Journal of Physiology and Pharmacology
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• v.3 no.4
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• pp.405-414
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• 1999

The role of platelet-activating factor (PAF) was investigated in intestinal ischemia/reperfusion (I/R) induced acute lung injury associated with oxidative stress. To induce acute lung injury following intestinal I/R, superior mesenteric arteries were clamped with bulldog clamp for 60 min prior to the 120 min reperfusion in Sprague-Dawley rats. Acute lung injury by intestinal I/R was confirmed by the measurement of lung leak index and protein content in bronchoalveolar lavage (BAL) fluid. Lung leak and protein content in BAL fluid were increased after intestinal I/R, but decreased by WEB 2086, the PAF receptor antagonist. Furthermore, the pulmonary accumulation of neutrophils was evaluated by the measurement of lung myeloperoxidase (MPO) activity and the number of neutrophils in the BAL fluid. Lung MPO activity and the number of neutrophils were increased (p＜0.001) by intestinal I/R and decreased by WEB 2086 significantly. To confirm the oxidative stress induced by neutrophilic respiratory burst, gamma glutamyl transferase (GGT) activity was measured. Lung GGT activity was significantly elevated after intestinal I/R (p<0.001) but decreased to the control level by WEB 2086. On the basis of these experimental results, phospholipase $A_2\;(PLA_2),$ lysoPAF acetyltransferase activity and PAF contents were measured to verify whether PAF is the causative humoral factor to cause neutrophilic chemotaxis and oxidative stress in the lung following intestinal I/R. Intestinal I/R greatly elevated $PLA_2$ activity in the lung as well as intestine (p<0.001), whereas WEB 2086 decreased $PLA_2$ activity significantly (p<0.001) in both organs. LysoPAF acetyltransferase activity, the PAF remodelling enzyme, in the lung and intestine was increased significantly (p<0.05) also by intestinal I/R. Accordingly, the productions of PAF in the lung and intestine were increased (p<0.001) after intestinal I/R compared with sham rats. The level of PAF in plasma was also increased (p<0.05) following intestinal I/R. In cytochemical electron microscopy, the generation of hydrogen peroxide was increased after intestinal I/R in the lung and intestine, but decreased by treatment of WEB 2086 in the lung as well as intestine. Collectively, these experimental results indicate that PAF is the humoral mediator to cause acute inflammatory lung injury induced by intestinal I/R.

• Korean Parent-Child Health Journal
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• v.3 no.1
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• pp.46-59
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• 2000

The purpose of this study is to determine whether the NCASA (Nursing Child Assessment Sleep/Activity Record) would be suitable to evaluate and to provide the basic resources for a Korean model of sleep/activity patterns during the first 6 months Korean infants' lives and to provide a basis for nursing intervention for mothers of early infants. The subjects of this study were 94 normal infants from birth to 6 months of age who visited the postpartum care center and two general hospitals located in Pusan from February 1 to April 28, 2000. The method of data collection was through convenient sampling. The instrument of this study was the NCASA translated by the Korean parent Child Health Academic Association. The collected data were analysed by mean, standard deviation, frequency percentage and ANOVA, Post Hoc test by use of SPSS/PC. The conclusions obtained from this study are summarized as follows: 1. The mean amount of daytime sleep was 8.06 hours. The mean amount of nighttime sleep was 6.31 hours. The mean amount of total daily sleep was 14.37 hours. The mean of the longest sleep period was 5.20 hours. The mean regularity of daytime sleep was 25.84%. The mean regularity of nighttime sleep was 77.69%. The mean regularity of total daily sleep was 42.60%. The mean frequency of nighttime wakenings was 2.33 times. 2. The mean amount of daytime activity was 8.25 hours. The mean amount of nighttime activity was 1.39 hours. The mean amount of daily total activity was 9.64 hours. The mean of the longest activity period was 3.80 hours The mean frequency of daytime feeding was 5.69 times. The mean frequency of nighttime feeding was 2.08 times. The mean frequency of total daily feeding was 7.74 times. The mean frequency regularity of feeding was 54.62%. The mean frequency of wakenings was 5.14 times. The mean frequency of crying was 1.90 times. 3. According to an analysis of sleep patterns based on an infant's age, there were some significant differences in the following factors: amount of daytime sleep(p<.001), amount of night time sleep(p<.05), amount of total daily sleep (p<.001), longest sleep period(p<.001), regularity of daytime sleep(p<.001), regularity of nighttime sleep(p<.01), regularity of total daily sleep(p<.001), frequency of nighttime wakenings(p<.001). 4. According to an analysis of activity patterns based on an infant's age, there were some significant differences in the following factors: amount of daytime activity(p<.001), amount of nighttime activity(p<.01), amount of total daily activity(p<.001), longest activity period(p<.05), frequency of nighttime feeding(p<.01), frequency of wakenings(p<.001). 5. The mean amount of a mother's day time was 16.30 hours. The mean amount of a mother's night time was 7.70 hours. In conclusion, the initial irregular sleeping and activity patterns of the early infant became regurized as the infant grew older and estabilished firmer patterns of sleeping and of activity.

• The Korean Journal of Physiology
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• v.16 no.1
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• pp.63-68
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• 1982

The change of plasma renin activity is one of the most important parameters explaining the pathological physiology of the hypertension. The relation between renal renin activity and plasma renin activity has not well been documented since last decades. In an attempt to clarify the relationship a series of experiments have been done in rats. The following results were observed. 1) Renal renin activity of clamped kidney increased after silver clipping and the increments were maintained until four to five weeks of operation. 2) Renal renin activity of the untouched contralateral kidney was vulnerable to be suppressed just after clamping, and the activity disappered almost below the limitation of the radioimmunoassay sensitivity up to four weeks. 3) Plasma lenin activity was changed by the renal renin activity, but the regression coefficient from the two kidney one clip Goldblatt hypertensive rats was different from the sham-operated, or age-matched control rats. 4) Plasma renin activity of all the groups tested has the exponential curve in terms of renal renin activity. These data suggest that the renal renin activity is important to control the plasma renin activity in certain experimental condition, especially in chronic status.