• Restorative Dentistry and Endodontics
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• v.24 no.1
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• pp.166-179
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• 1999

Apical sealing is essential for the success of surgical endodontic treatment. Root-end cavity is apt to be contaminated with moisture or blood, and is not always easy to be dried completely. The purpose of this study was to evaluate the influence of dry methods of retrocavity on the apical seal in endodontic surgery. Apical seal was investigated through the evaluation of apical leakage and adaptation of filling material over the cavity wall. To investigate the influence of various dry methods on the apical leakage, 125 palatal roots of extracted human maxillary molar teeth were used. The clinical crown of each tooth was removed at 10 mm from the root apex using a slow-speed diamond saw and water spray. Root canals of the all the specimens were prepared with step-back technique and filled with gutta-percha by lateral condensation method. After removing of the coronal 2 mm of filling material, the access cavities were closed with Cavit$^{(R)}$. Two coats of nail polish were applied to the external surface of each root. Apical three millimeters of each root was resected perpendicular to the long axis of the root with a diamond saw. Class I retrograde cavities were prepared with ultrasonic instruments. Retrocavities were washed with physiologic saline solution and dried with various methods or contaminated with human blood. Retrocavities were filled either with IRM, Super EBA or composite resin. All the specimens were immersed in 2% methylene blue solution for 7 days in an incubator at $37^{\circ}C$. The teeth were dissolved in 14 ml of 35% nitric acid solution and the dye present within the root canal system was returned to solution. The leakage of dye was quantitatively measured via spectrophotometric method. The obtained data were analysed statistically using one-way ANOVA and Duncan's Multiple Range Test. To evaluate the influence of various dry methods on the adaptation of filling material over the cavity wall, 12 palatal roots of extracted human maxillary molar teeth were used. After all the roots were prepared and filled, and retrograde cavities were made and filled as above, roots were sectioned longitudinally. Filling-dentin interface of cut surfaces were examined by scanning electron microscope. The results were as follows: 1. Cavities dried with paper point or compressed air showed less leakage than those dried with cotton pellet in Super EBA filled cavity (p<0.05). However, there was no difference between paper point- and compressed air-dried cavities. 2. When cavities were dried with compressed air, dentin-bonded composite resin-filled cavities showed less apical leakage than IRM- or Super EBA-filled ones (p<0.05). 3. Regardless of the filling material, cavities contaminated with human blood showed significantly more apical leakage than those dried with compressed air after saline irrigation (p<0.05). 4. Outer half of the cavity showed larger dentin-filling interface gap than inner half did when cavities were filled with IRM or Super EBA. 5. In all the filling material groups, cavities contaminated with blood or dried with cotton pellets only showed larger defects at the base of the cavity than ones dried with paper points or compressed air.

• Journal of Chest Surgery
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• v.30 no.4
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• pp.383-389
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• 1997

From March, 1992 to March, 1996, a total of 279 patients underwent coronary bypass surgery at the Sejong General Hospital, Puchon. We selected 22 patients with severe left ventricular(LV) dysfunction from them. The criteria were the presence of global or segmental abnormalities of left ventricular contraction and LV ejection fraction(EF) less than 35% based on biplane LV angiography by planimetry method. The mean age of 17 male and 5 female patients was 60$\pm$5.6years(range:47~73 years). All had the anginas, which were Canadian class II in 6, class 111 in 12 and class IV in 4. All patients except one had the history of previous myocardial infarction more than once. Seven of them had the symptoms and signs of congestive heart failure, such as dyspnea on excertion and increased pulmonary vascular markings. Their mean LVEF was 29.4$\pm$4 5%(range : 18~35%) and mean LV end-diastolic pressure was 18.7 $\pm$8. 2mmHg(range:10~42mmHg). 21 patients had 3 vessel-disease and 1 had 2 vessel-disease. Complete revascularization was tried with the use of 16 internal mammary arteries and 60 sapheuous veins and 3 radial arteries grafts. The mean number of distal anastomosis was 3.5$\pm$ 1.1. Concomitantly, one mitral valvuloplasty and annuloplasty was performed in the patient with moderate mitral regurtigation. The hospital mortality was 4.5%. During the follow-up, there were 3 late deaths. Of 18 survivors, 2 patients were lost in follow-up 24 and 27 month respectively after operation and the remaining 16 patients have bcen followed up with an average of 30.4 $\pm$ 13.4 months.15 patients had improvement with respect to angina but 8 patients still have the continuing or progressing heart failure. The 1-year, 2-year and 3-year actuarial survival rate was 85.2, 69.1, 46.1%, respectively. This study indicates that coronary artery bypass sur ery can be performed in the patients with severe LV dysfunction at acceptable risk but does not greatly contribute to the improvement of congestive heart failure.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.7 no.3
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• pp.418-427
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• 1997

The effect of $La_2O_3$ as a dopant on the microstructure structure, crystal structure and electrical properties was studied. $0.05Pb(Sn_{0.5}Sb_{0.5})O_3＋0.11PbTiO_3＋0.84PbZroO_3＋0.4Wt%MnO_2$ (=0.05PSS ＋0.11PT＋0.84PZ+0.4wt%$MnO_2$) systems doped with 0, 0.1, 0.3, 0.5, 0.7, 1, 3, 5 mole% $La_2O_3$ were fabricated and investigated sintering density, crystal structure and micro-structure. The sintered 0.05PSS＋0.11PT＋0.84PZ+0.4wt%$MnO_2$ system doped with $La_2O_3$showed sintering density of the range of 7.683 g/㎤ of 0 mole% doping to 7.815 g/㎤ of 0 mole% doping. The average grain sizes in the range of 0 to 5 mole% $La_2O_3$were decreased from 9.0 $\mu\textrm{m}$ to 1.3 $\mu\textrm{m}$. X-ray diffraction investigation of sintered bodies showed that solid solutions were formed between 0.05PSS＋0.11PT＋0.84PZ+0.4wt%$MnO_2$ system and $La_2O_3$ in the range of 0 to 1 mole% but second phases were formed in case of 3, 5 mole%. Dielectric constants at 1 kHz were increased with 0 to 3 mlole% $La_2O_3$ before and after poling at the condition of 5 $KV_{DC}$/mm at $120^{\circ}C$ or $140^{\circ}C$ during 20 minutes. All Dielectric losses at 1 kHz were less than 1%, Curie temperatures were $208^{\circ}C$, $183^{\circ}C$, $152^{\circ}C$ and $127^{\circ}C$ at 0, 0.5, 1, 3 mole% $La_2O_3$ respectively. The values of $K_p$ were increased from 0 to 3 mole% $La_2O_3$ after poling at condition of 5 $KV_{DC}$mm at the condition of $120^{\circ}C$ or $140^{\circ}C$. The case of 0.7 mole% $La_2O_3$doped 0.05PSS＋0.11PT＋0.84PZ+0.4wt%$MnO_2$ system showed $K_p$ of 14.5% by poling at $140^{\circ}C$ during 20 minutes.

• Journal of Bio-Environment Control
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• v.28 no.3
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• pp.218-224
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• 2019

This study was conducted to compare the effect of salicylic acid (SA), an ethylene biosynthesis inhibitor, and the 1-methylcyclopropene (1-MCP) fumigation, to prevent fruit quality deterioration and physiological disorders during the shelf-life of Korea's leading export grape variety 'Campbell Early'. The berries treated with SA after 1-MCP fumigation (1-MCP+SA) showed a higher firmness value and titratable acidity than single treatment of SA or 1-MCP. The rate of shattered berry was high as 41.7% for 100ppm ethephon spray, 40.8% for $25{\mu}M$ SA, and 38.2% for 1,000ppb 1-MCP, but showing only 18.7% when the SA was applied after 1-MCP fumigation. The ratio of short brushes less than 1mm was largest at 74.3% for ethephon treatment, while 1-MCP+SA treatment was found to have the longest brush length among all treatments, with a 2-4mm ratio of 22.8% and a 4-6mm ratio of 27.9%. The weight of rachis was found to be the lowest at 2.3g in the ethephon treatment, and the reduction of rachis weight loss per cluster by 1-MCP+SA treatment was evident. In addition, 1-MCP+SA treatment were effective in mitigating stem browning and berry decay during the 16-day storage period at $19^{\circ}C$ in this cultivar, so it is believed that they can be used as a practical post-harvest treatment in grape exportation.

• The Journal of Advanced Prosthodontics
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• v.6 no.2
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• pp.71-78
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• 2014

PURPOSE. The objective of this study was to evaluate the clinical acceptability of all-ceramic crowns fabricated by the digital veneering method vis-$\grave{a}$-vis the traditional method. MATERIALS AND METHODS. Zirconia specimens manufactures by two different manufacturing method, conventional vs digital veneering, with three different thickness (0.3 mm, 0.5 mm, 0.7 mm) were prepared for analysis. Color measurement was performed using a spectrophotometer for the prepared specimens. The differences in shade in relation to the build-up method were calculated by quantifying ${\Delta}E^*$ (mean color difference), with the use of color difference equations representing the distance from the measured values $L^*$, $a^*$, and $b^*$, to the three-dimensional space of two colors. Two-way analysis of variance (ANOVA) combined with a Tukey multiple-range test was used to analyze the data (${\alpha}$=0.05). RESULTS. In comparing means and standard deviations of $L^*$, $a^*$*, and $b^*$ color values there was no significant difference by the manufacturing method and zirconia core thickness according to a two-way ANOVA. The color differences between two manufacturing methods were in a clinically acceptable range less than or equal to 3.7 in all the specimens. CONCLUSION. Based on the results of this study, a carefully consideration is necessary while selecting upper porcelain materials, even if it is performed on a small scale. However, because the color reproducibility of the digital veneering system was within the clinically acceptable range when comparing with conventional layering system, it was possible to estimate the possibility of successful aesthetic prostheses in the latest technology.

• Journal of Korean Foot and Ankle Society
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• v.20 no.4
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• pp.152-157
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• 2016

Purpose: To evaluate the effect of shortening scarf osteotomy on pain relief and range of motion (ROM) of the first metatarsophalangeal joint in hallux rigidus patients. Materials and Methods: Twenty-three cases of 19 patients who had been treated with shortening scarf osteotomy for the hallux rigidus between January 2007 and December 2013 were reviewed. The mean follow-up period was 21.4 months, and the mean age was 59.2 years. The first metatarsal bone was shortened until the ROM of the first metatarsophalangeal joint was greater than $80^{\circ}$ or $40^{\circ}$ of dorsiflexion. The length shortened by scarf osteotomy was measured. The authors also measured and compared the joint interval difference of the standing foot using an anteroposterior radiography. Moreover, the difference of ROM of the first metatarsophalangeal joint between the preoperative and final follow-up periods was also compared. The clinical results were evaluated and compared using the American Orthopaedic Foot and Ankle Society (AOFAS) scoring system and visual analogue scale (VAS) score. Results: The mean shortening length was about 6.5 mm (range, 4~9 mm). The joint space has been increased to 1.8 mm, and the ROM of the first metatarsophalangeal joint has also been increased to $18.4^{\circ}$ after the operation. In three cases, the postoperative ROM has been decreased to less $10^{\circ}$. The AOFAS score has been improved from 41.7 (range, 32~55) to 86.2 (range, 65~95), and the VAS score was also decreased from 3.7 (range, 3~5) to 1.3 (range, 0~3). Two cases have shown no decrease in pain even after the operation. Conclusion: Shortening scarf osteotomy was found to decrease joint pain by decompressing the pressure of the first metatarsophalangeal joint. This osteotomy also helped improve the ROM of the first metatarsophalangeal joint. Shortening scarf osteotomy can be considered one of the effective methods for joint preservation.

• Korean Journal of Clinical Pharmacy
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• v.12 no.1
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• pp.29-38
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• 2002

Hypertension is an important public health problem because it increases the risk of stroke, angina, myocardial infarction, heart failure, and end-stage renal disease. If it is not actively treated, morbidity and mortality increase with hypertension-induced complications and quality of life decreases. This study was to evaluate the use of antihypertensive drugs and blood pressure changes and to compare algorithms chosen (or the 1st and 2nd line therapy of hypertension based on the JNC VI recommendations. The medical charts of 222 patients with essential hypertension at St. Vincent's Hospital in Suwon from January 1997 to January 2000 were reviewed retrospectively. Data collection and analysis included baseline BP underlying diseases and complications, administered antihypertensives, BP changes, changes of antihypertensive regimen, and adverse effects with treatments. As results, the higher BP the patients had, the more frequent they had target organ damages and clinical cardiovascular diseases. Mean duration to reduce blood pressure less than 140/90 mmHg was 8 weeks in $85.3\%$ of the patients. The rate of control in BP was $82.4\%$ at 6 months. The major antihypertensive drugs prescribed were calcium channel blockers $(61.8\%)$ , ACE inhibitors $(19.1\%),\;\beta-blockers\;(13.7\%)$ and diuretics $(5.3\%)$ as the 1st-line monotherapy. The methods of treatment used as the 1st-line therapy were monotherapy$(59\%)$ and combination therapy $(41\%)$. Blood pressure change was significantly greater for combination therapy than monotherapy$(-26.2\pm21.4\;vs.\;-18.56\pm16.7$ mmHg for systolic blood pressure; P<0.003, $-16.9\pm13.2\;vs.\;-9.2\pm12.8$ mmHg for diastolic blood pressure; p<0.001). When blood pressure was not completely controlled with the first antihypertensive selected, the 2nd line therapy had 4 options: addition of 2nd agent from different class; $66.2\%$, substitution with another drug, $21.9\%$ increase dose $11.9\%$ continue first regimen $27.9\%$ Calcium channel blockers were the most frequently prescribed agents. This was not comparable to the JNC VI guideline which recommended diuretics and $\beta-blockers$ for the 1st-line therapy. Most of patients achieved the goal BP and maintained it until 6 months, but the remaining patients should be controlled more tightly to improve their BP with combination of life style modification, patient education, and pharmacotherapy.

• Imaging Science in Dentistry
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• v.44 no.3
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• pp.221-227
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• 2014

Purpose: This study aimed to investigate the clinical anatomy of lower premolar roots in a Spanish population by using cone-beam computed tomography (CBCT), correlating findings with patient gender and tooth type. Materials and Methods: Using 70 CBCT images, we evaluated 126 healthy, untreated, well-developed lower premolars. The number and morphology of roots and root canals, and the foramina number were assessed. Results for gender and tooth type were compared using the chi-squared and ANOVA tests. Results: The average length of teeth and roots was significantly higher in men (p=0.00). All 126 premolars had a single root. One canal was found in 83.3% of the premolars, with no gender or tooth type differences; Vertucci configuration types I and V were the most prevalent. The first premolars showed significantly greater variability than the second premolars (p=0.03). A single apical foramen was found in 89.7% of the premolars, with no differences by tooth type. Women had a significantly higher prevalence of two apical foramina than men (p=0.04). Some degree of curvature was observed in 65% of the premolars, with no differences by gender or tooth type. A root angle of more than $20^{\circ}$ was found in 12.98% of the premolars, without any differences by gender or tooth. Conclusion: All premolars were single-rooted. One canal had the most prevalent morphology. More variability in canal anatomy was found in the first premolars. Curvatures greater than $20^{\circ}$ were found at less than 5 mm from the apex.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.3 s.333
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• pp.25-34
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• 2005

In this paper, we analyzed and measured the electrical crosstalk characteristics of a triplex transceiver module for ethernet Passive optical networks(EPONS). And we improved the electrical crosstalk levels using Dummy ground lines with signal lines. The triplex transceiver module consists of a laser diode as a transmitter, a digital photodetector as a digital data receiver, and a analog photodetector as a community antenna television signal receiver. And there are integrated on silicon substrate. The digital receiver and analog receiver sensitivity have to meet -24 dBm at $BER=10^{-l2}$ and -7.7 dBm at 44 dB SNR. And the electrical crosstalk levels have to maintain less than -86 dB from DC to 3 GHz. From analysis and measurement results, the proposed silicon substrate structure that contains the Dummy ground line with $100\;{\mu}m$ space from signal lines and separates 4 mm among devices respectively, is satisfied the electrical crosstalk level compared to simple structure. This proposed structure can be easily implemented with design convenience and greatly reduced the silicon substrate size about $50\%$.

• Clinical and Experimental Pediatrics
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• v.45 no.8
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• pp.994-999
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• 2002

Purpose : There is a predilection for subacute necrotizing lymphadenitis(SNL) in young Asian women. Few pediatric cases have been reported. This study was performed to evaluate clinical features of children with SNL. Methods : We retrospectively analyzed clinical features of 23 cases of SNL under 15 years of age identified in Nowon Eulji Hospital from February 1995 to January 2002. Two cases were diagnosed by excisional biopsy and 21 cases by fine needle aspiration. Results : The ages ranged from 14 months to 14 years(mean $8.1{\pm}3.8$ years). The male to female ratio was 1 : 1.6. Ten cases(10/23) were diagnosed in 2000. The onset was more frequent in spring. The common presenting symptoms were neck mass(22/23), pain(12/20) and fever(8/18). Fever subsided within two weeks in seven out of eight and lymphadenopathy resolved within five months in 14 out of 15. The mean WBC count was $7,664{\pm}3,454/mm^3$. Elevated levels of ESR(10/ 12) and lactate dehydrogenase(5/6) and positive reaction for CRP(3/4) were frequent. Radiologically measured greatest diameter of the enlarged lymph nodes was less than 2 cm in 14 out of 15. One case occurred in a child with alopecia areata and one case with type 1 diabetes. Clinical outcomes were good in 23 cases. Conclusion : SNL should be considered in children with cervical lymphadenopathy regardless of fever or pain. SNL seems not rare in pediatric groups in Korea.