• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.3
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• pp.249-256
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• 1986

The carp (Cyprinus carpio) used in the experiment were hatched in the spring this year and reared to 5.96g($4.84{\sim}6.55g$) in mean weight in a nursery pond at Daeyon fish farm, Pusan, Korea. The sample fish were exposed to different conditions of total ammonia (TA-N) concentrations 10, 20 and 30ppm and pH 6.5, 7.0, 7.5 and 8.0 at water temperatures 20, 25 and $30^{\circ}C$ for 24, 48 and 72 hours. After the procedure, the gill, liver and kidney of the fish were examined histopathologically. In this experiment, with the rise of water temperature, increase of pH and ammonia concentration, and the extension of exposure time the three organs showed the tendency of apparent abnormal changes such as hypertrophy and necrosis in their tissues. At $20^{\circ}C$ of water temperature gill tissue did not show any abnormality regardless of the change of pH at 10 ppm of ammonia concentration for 24 hours of exposure, but beyond the conditions given above, there occurred hypertrophy and the epithelium of gill lamellae was detached. The detach of gill lamellae epithelium initiated from the proximal part of the gill lamellae then gradually spread toward the uppermost tip. The heavier vacuolation of the liver was observed with the rise of water temperature and pH, and such morbid state in the liver was considered to be the result of edema in the liver tissue. The kidney showed no damage to the renal tubule epithelium at pH 6.5, but it was damaged at pH 8.0 when exposed to 30 ppm ammonia at $20^{\circ}C$ for 24 hours.

• The Journal of Korean Academy of Prosthodontics
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• v.35 no.2
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• pp.277-295
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• 1997

After clinical adjustment of dental casting restoration, re-polishing procedure is recommanded because the smooth gold sureface is lost. But there is the possibility to get more loose contact than that intended by loss of gold alloy according to the kinds of polishing materials and polishing time. Therefore in this study I polished type II gold alloy with 390gm force, 20,000rpm speed, and 8 kinds of gold alloy polishing materials, fabricated by 4 companies and then measured the amount of loss of gold alloy with Surfcorder SEF-30D and observed alloy surfaces polished by 3 brown rubber points with SEM. The amount of loss of gold alloys polished with 8 kinds of polishing materials and the degree of smoothness of gold alloys according to polishing time and polishing materials were compared. The following results were obtained : 1. When the amount of loss of gold alloys polished with 3 kinds of brown rubber point was compared, Alphalex brown point had the most amount of alloy loss, followed in decreasing order by Shofu brown point and Eveflex brown point. There was statistically significant difference in the amount of alloy loss according to polishing materials. 2. When the amount of loss of gold alloys polished with 5 kinds of green rubber point was compared, Shofu green point had the most amount of alloy loss, followed in decreasing order by Alphaflex green point, Dedeco green clasp polisher, and Eveflex green point. There was statistically significant difference in the amount of alloy loss according to polishing materials except Alphaflex green point and Dedeco green clasp polisher. 3. When the amount of loss of gold alloys polished with all kinds of rubber point was compared, there was no significant difference in Eveflex brown point, Alphaflex green point, and Dedeco green clasp polisher. 4. When average amount of alloy loss per 1 revolution by polishing materials was compared, Alphalex brown point had the greatest value as $0.329{\mu}m$ and Shofu supergreen point had the lowest value as $0.022{\mu}m$. 5. When the degree of sureface smoothness of gold alloy polished with 3 kinds of brown rubber point was compared, In Alphalex brown point surface roughness was completely lost after 20 seconds polishing time, in Shofu brown point 30 seconds, in Eveflex brown point 40 seconds. But in every gold alloys fine scratch formed by rubber points was observed. Based on the results of this study, as rubber polishing materials used in polishing of dental casting restoration after clinical adjustment influenced on the tightness of occlusal or proximal contact, we should make dental casting restoration with minimum error through careful laboratory procedure and form very smooth surface of restoration with tripoli and rouge after use of silicone polishing materials.

• The Journal of Korean Academy of Prosthodontics
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• v.35 no.4
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• pp.706-718
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• 1997

Ceramometal crowns are common restorations in fixed prosthodontics because of their casting accuracy, the high strength properties of the metal, and the cosmetic appearance of porcelain. However, deterioration of the initial fit of the metal coping has been observed after the porcelain firing cycle. The distortion due to repeated firing makes it difficult to fit crown margin and elicits microleakage. The major causes of distortion are the residual stress that accumulate during wax-up, casting, cold work and the induced stress caused by the mismatch of porcelain-metal thermal contraction. This study examined the marginal fit changes of metal copings in relation to repeated firing and the effects of heat treatment that reduce the distortion resulted from residual stress. The marginal changes of the copings that were treated with conventional method and those treated with heat before repeated firing, were evaluated. The metal die which represented preparations of a maxillary central incisor was fabricated, and 45 wax patterns were cast with nonprecious metal alloys. The heat treatment of each group was performed as follows. Group 1(control) : Casting - Devesting - Cold work - Firing Group 2 : Casting - Heat treatment - Devesting - Cold work - Firing Group 3 : Casting - Devesting - Cold work - Reinvesting - Heat treatment - Devesting - Firing The copings were fired 3 times. After each firing, the marginal fit changes were measured with inverted metallurgical microscope at the 4 reference points located at labial, lingual, and both proximal surface. Measurements were compared, and statistically analyzed. The results were as follows ; 1. In all groups, the highest value of marginal fit changes of the copings studied were found after the first firing cycle. 2. When the distortion of each experimental group at the first firing cycle were compared, group 1 exhibited the greatest changes($20-27{\mu}m$), followed by group 2($9-13{\mu}m$), and group 3($8-10{\mu}m$). 3. The copings treated with heat before devesting(group 2) revealed significantly smaller marginal fit changes than the copings treated with conventional method(group 1). (p<0.01) 4. The copings treated with heat after reinvesting(group 3) revealed significantly smaller marginal fit changes than the copings treated with conventional method(group 1). (p<0.01) 5. No siginificant differences in marginal fit changes were found between the copings treated with heat before devesting(group 2) and the copings treated with heat after reinvesting(group 3). (p>0.01)

• The Korean Journal of Pharmacology
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• v.32 no.1
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• pp.93-102
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• 1996

Platinum coordination complexes are currently one of the most compounds used in the treatment of solid tumors. However, its use is limited by severe side effects such as nephrotoxicity. Our platinum-based drug discovery program is aimed at developing drugs capable of diminishing toxicity and broadening the clinical spectrum of activity of cisplatin. We synthesized new Pt(II) complex analogue containing 1,2-diaminocyclohexane (dach) as carrier ligand and 1,3-bis(diphenyl phosphino)propane (DPPP) as a leaving group. Furthermore, nitrate was added to improve the solubility. A new series of PC-1 [Pt(cis-dach) (DPPP)]. $2NO_3_2$ was synthesized and characterized by their elemental analysis and by various spectroscopic techniques [infrared (IR), $^{13}carbon$ nuclear magnetic resonance (NMR)]. PC-1 was demonstrated acceptable antitumor activity aganist SKOV -3, OVCAR-3 human ovarian adenocarcinomacells and significant activity as compared with that of cisplatin. The toxicity of PC-1 was found quite less than that of cisplatin using MTT, $[^3H]thymidine$ uptake and glucose consumption tests in rabbit proximal tubule cells, human kidney cortical cells and human renal cortical tissues. Based on these results, this novel platinum compound represent a valuable lead in the development of a new anticancer chemotherapeutic agent capable of improving antitumor activity and low toxicity.

• Journal of Biomedical Engineering Research
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• v.25 no.2
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• pp.151-156
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• 2004

The purpose of this study was to develop EMG triggered FES system for restoration of upper extremity function in chronic hemiplegic patients and to identify the optimal location of electrode application for the EMG triggered FES system which produces effective muscle contraction and detects EMG activity for extension in the wrist and finger joints. The stimulus system was composed of EMG measuring component, constant current component and the program for muscle contraction by EMG triggered FES and passive FES. Parameter of electrical stimulation was 35 ㎐ in frequency, 150 ${\mu}\textrm{s}$ in pulse width and symmetric bi-phasic wave. In 15 hemiplegic patients, EMG triggered FES was applied to the proximal half of forearm which was divided into 12 areas. The most sensitive area for measuring EMG activities during extension of the wrist and fingers was area 4, 5 and the optimal location of electrical stimulation for producing extension of the wrist and fingers was area 4, 5, 7, 8. These results suggest that the area 4 and 5 was considered as the most optimal location of electrode application for measuring EMG activities as well as producing extension of the wrist and fingers by EMG triggered FES system.

• The Korean Journal of Pharmacology
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• v.2 no.1 s.2
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• pp.49-69
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• 1966

For the purpose of stydying the pharmacodynamic action of methemoglobin, the author made the following experiments: 1. Preparation of hemoglobin and methemoglobin solutions: Red cell suspension from rabbit blood was hemolysed with distilled water and then divided into two portions. One portion was dialysed through cellophane paper and made isotonic with the proper amount of sodium chloride. The second portion was treated with sodium nitrite to convert hemoglobin to methemoglobin, dialysed through cellophane paper and made isotonic. 2. The concentration of methemoglobin in solution, plasma and urine was determined by Horecker and Brackette's method, and that of hemoglobin by the cyanmethemoglobin method. 3. The concentration of methemoglobin and hemoglobin in the plasma and urine of rabbits was measured at several intervals of time after infusion of the above samples. 4. The blood pressure and respiration of rabbits were recorded on a kymograph, and the effects of the samples on them were observed. 5. The effects of the samples on the movements of the in-situ heart and the isolated intestine of rabbits were studied. 6. The kidneys of rabbits were excised 4 to 5 hours after injection of the samples, and histopathological examinations were made. These experiments revealed the following results: 1. When methemoglobin solution was allowed to stand in room air, there was no decrease in the concentration of methemoglobin. 2. When methemoglobin solution was mixed with whole blood and incubated at $37^{\circ}C$, the concentration of methemoglobin decteased gradually. 3. After the infusion of methemoglobin and hemoglobin solutions, the rate of disappearance of methemoglobin in the plasma was more rapid than that of hemoglobin in the plasma. The higher the initial concentration in the plasma, the larger was the rate of disappearance of methemoglobin. 4. The rate of disappearance of methemoglobin was exceedingly rapid for 30 minutes after the infusion. 5. The urinary excretion of methemoglobin was more rapid than that of hemoglobin. 6. It would seem that the circulating blood contains substances which are promptly mobilized in the plasma to reduce methemoglobin to hemoglobin. 7. Moderate amounts of methemoglobin solution caused some rise in the blood pressure and a transient acceleration of the respiration of the rabbits. These effects of methemoglobin were milder than those of hemoglobin. 8. The movements of the in-situ heart and the isolated intestine of rabbits were accelerated by methemoglobin. These accelerating effects were milder than those of hemoglobin. 9. In the kidneys of rabbits treated with methemoglobin solution, hyperemia of the glomeruli, cloudy swelling and hemoglobin deposit in the tubular epithelium, hemoglobin casts in the tubular lumina of the proximal tubules, and interstitial congestion were constantly observed. There was no definite difference between the histological findings in the rabbit kidneys injected with methemoglobin, and those injected with hemoglobin solutions.

• Journal of Biomedical Engineering Research
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• v.39 no.1
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• pp.48-54
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• 2018

In this study, We developed a Ancillary device for child radiography for X-ray of children under 5 years old and verified its effectiveness. Chest X-rays of children younger than 5 years of age were performed by Supine method at the position of Table detector, Short - Source to Image Receptor Distance(SID). Existing Supine and Short -SID imaging methods cause many problems, such as errors in image reading and excessive radiation exposure dose to patients, but the use of an Ancillary device for child radiography(ADCR) solves these problems. A total of 160 children were divided into the Upright group using ADCR and Supine group without ADCR. The chest X-ray image was visually evaluated by two radiologists with reference to the European Commission's List of Quality Criteria for Diagnostic Radiographic Images in Pediatrics. The total score of the qualitative evaluation was 5.15% higher in the chest upright method using ADCR than in the chest supine method without ADCR, and the chest upright method score was higher than that of the chest supine method in items 1 to 7. whether infants have deep inspiration or not, 4.87% higher for item 1, whether infants rotate or not and the degree of tilting, 0% higher for the item 2, the reproduction of image from just above apices of lungs to T12/L1, 0% for the item 3, reproduction of the vascular pattern in central 2/3 of the lungs, 6.92% higher for the item 4, reproduction of the trachea and the proximal bronchi, 12.9% higher for the item 5, visually sharp reproduction of the diaphragm and costo-phrenic angles, 10% higher for the item 6, reproduction of the spine and paraspinal structures and visualisation of the retrocardiac lung and the mediastinum, and 3.65% higher for the item 7. Items 2 and 3 showed no statistically significant differences(P > 0.05), and items 1, 4, 5, 6, and 7 showed statistically significant differences(P < 0.05). In conclusion, Upright method using ADCR in pediatric chest X-ray is considered as a good alternative to existing Supine method.

• Journal of Elementary Mathematics Education in Korea
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• v.13 no.1
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• pp.75-95
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• 2009

The purpose of the study was to investigate the scaffolding processes of children in mathematical problem solving. 3 groups of 4th grade students participated in the study and the researchers proceeded the study for 4 months. The procedures of this research were as followings. First, when the learners solved the problems, the categories of scaffolding processes(by way of unit line coding belong in open codings, the categories were made 25 concepts and integrated 20 subcategories) were produced the 7 results: invite to the learning, set the problems, affective aids, attempt self learning, re-ordering between learners and affirmation self learning. Second, the processes of scaffolding in mathematic problem solving resulted in condition, the present condition, action/interaction and the outcomes. Third, the cognitive and affective aids that discovered in the scaffolding processes were considered the main categories of learner's scaffolding processes in solving the mathematic problems. In conclusion, first, the learners' scaffolding processes, based on Vygotsky's "the zone of proximal development" in selection and presentation of mathematic problems, are very diverse. Peers' affective aids are very important in solving the problems. Second, learners in the scaffolding processes exchange the cognitive and affective aids with each other with joy and earnestness, and the aids can give assistance to all the participants. Third, in the results of observation and analysis in learners' scaffolding processes, it is meaningful to know how they think. Finally, the learners' scaffolding processes are a little unsystematic and illogical compared to those of adults, but those of scaffolders are so similar to those of learners' cognitive and affective systems that they can provide teachers with many merits in understanding and teaching learners.

• Journal of Veterinary Clinics
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• v.26 no.2
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• pp.176-180
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• 2009

Two year-old female miniature schnauzer was presented with depression, abdominal pain and inappetence. Physical examination revealed tachypnea, fever, and abdominal pain. Leukocytosis with neutrophilia was shown in complete blood count. Radiograph revealed the increase of opacity in parallel to vertebra and dislocation of descending colon. Calculi and sludge in bladder, hydronephrosis and dilation of proximal ureter in right kidney were observed in ultrasonographic examination; also, irregular shape of structure in retroperitoneal cavity was observed. Urinalysis showed protein urine and hemtauria. Many epithelial cells, spindle cells, calcium oxalate dihydrate crystals, struvite crystals, amorphous crystals and granular casts, WBC, cocci were examined in urine sediment test. ERD-kit test result was highly positive. Based on those test and excretory urogram pyelonephritis and complete unilateral obstruction of ureter were confirmed. A balloon type structure in retroperitoneal cavity was found through the exploratory laparotomy. In cytologic examination of aspirated fluid from dilated area many degenerated neutrophils and phagocytized cocci were observed. Staphylococcus intermedius was cultured from aspirated fluid. Based on these clinical results retroperitoneal abscesses caused by Staphylococcus intermedius was diagnosed with ureter obstruction and concurrent cystic calculi. Nephrectomy of right kidney with ureter was performed.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.2
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• pp.316-325
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• 2003

In this paper, the effect of Ganopoly(extracts of Ganoderma lucidum) and Ganopoly/C+(70% Ganopoly + 30% chitosan) on cisplastin-induced nephrotoxicity was investigated in Sprague-Dawley rats. A single dose of cisplastin(5 ㎎/㎏) kg) was administered intraperitoneally after pretreatment of saline, Ganopoly and Ganopoly/C+ for 7 days. The nephrotoxicity and renal function were manifestated by the changes of body weight, blood pressure, biochemical changes and solute in urine and plasma. After the treatment of CDDP(cis-dichlorodiamineplatinum), a significant elevation of kidney weight, serum urea, cretinine, urine volume for 24 hours, urine magnesium, and a severe or significant decrease in body weight, blood pressure, creatinine clearance, urine osmolarity, serum albumin, etc. The nephrotoxicity was further confirmed by a significant decrease in glutathione S-transferase(GSH) in urine and kidney homogenate, GSH, glutathione peroxidase(GSH-Px) and catalase in kidney tissue. And also the lipid peroxidation was significantly increased in kidney homogenate. These signs of nephrotoxicity was ameliorated by the pretreatment and consecutive administration of Ganopoly and Ganopoly/C+ for 14 days after the Lp. injection of CDDP on 7th day after pretreatment of Ganopoly and Ganopoly/C+. The amelioration of nephrotoxicity was evidenced by significant reduction in serum urea and creatinine concentration, and improvement of other index of renal function. And The activity of antioxidant enzymes were partially recovered in kidney tissue of rats treated by CDDP and the administration of Ganopoly and Ganopoly/C+. These results indicate the cispastin induced nephrotoxicity is due to an impairment of tubular reabsorption systems enhanced by necrosis of proximal tubule, and the Ganopoly and Ganopoly/C+ has a partial protective effect on nephrotoxicity induced by CDDP. The polysacchride of Ganoderma lucidum may improve the therapeutic index of nephrotoxicity induced by CDDP. However, it is needed to elucidate the mechanism for confirming the therapeutic effect.