• The Korean Journal of Ceramics
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• 제4권4호
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• pp.331-335
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• 1998

R-curve, of three kinds of silicon nitride-based ceramics were measured, using single edge notched beam (SENB) method at room and at elevated temperatures, up to $1200^{\circ}C$. Stable fraacture was seen on ceramic materials with SENB specimens if the machined notch is deep enough, even though the crack resistance did not increase with crack length. Hot pressed silicon nitride did not show the rising R-curve behavior at room temperature, but it showed some rising at $1000^{\circ}C$ and above. Si3N4 reinforced with SiC whiskers showed no rising behavior at room and elevated temperatures, as it has smaller grain size, compare to the monolithic specimen. Gas pressure sintered silicon nitride had very large and elongated grains, and it showed rising R-curve even at room temperature. However, it showed some creep behavior at $1200^{\circ}C$ and the calculated R-curve on this condition did not show a good result. We cannot apply this technique on this condition for obtaining the R-curve.

• 대한치과의사협회지
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• 제11권5호
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• pp.337-340
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• 1973

The authers have studied the marginal leakage on various filing materials : Composite resin, Polycarboxylate cement, Zinc phosphate cement, Silicate cement and Zinc-oxide eugenol cement, by means of penetration of 2% aquous methylene blue between cavity walls and filing materials at body temperature and at thermal changs in the range of 4~60℃ The results revealed as follows. 1) All the filling materials revealed the penetration of dye between cavity walls and filling materials. 2) Zinc-oxide eugenol cement was the most effective to prevent the dye penetration on the contrary silicate cement cases showed greatest leakage at 37℃ and at temperature changes in range of 4-60℃. 3) The composite resin showed moderate leakage either at 37℃ or at thermal changes 4) Marginal obstructions of polycarboxylate cement were unsatisfactory at 37℃ and at temperature changes.

• 농촌의학ㆍ지역보건
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• 제23권2호
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• pp.205-213
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• 1998

In order to find out the status of routine-immunization in a rural area, this study was performed, through analyzing the data which was obtained from the immunization register of infants who was born at Su-Dong myun in 1996 and 1997, managed by Su-dong Myun health subcenter. The results are as follows. 1. B.C.G immunization rate was the highest such as 52.2% within 1 month and next order such 34.8% at 2 month in 1996. In 1997, the highest such as 73.8%, almost all, within 1 month. 2. D.P.T immunization rate in 1996 showed, almost all, the highest at 3 month(79.4%) for 1st dose and at 5 month(78.4%) for 2nd dose. However, the rate for 3rd dose showed the highest at 7 month(51.4%), and next order at 8 month(35.1%) and at 6 month(13.5%). D.P.T immunization rate in 1997, similarly showed the highest at 3 month(81.8%) for 1st dose, at 5 month(71.2%) for 2nd dose and at 7 month(71.4%) for 3rd dose. 3. Hepatitis B immunization rate showed the highest at birth at once or within one week(87.0%) for 1st dose in 1996 and (94.7%) in 1997. The rate for 2nd dose showed the highest at 2 month(51.7%) in 1996 and (50.0%) in 1997, and next order at 1 month(44.8%) in 1996 and (34.4%) in 1997. The rate for 3rd dose showed the highest at 3 month(54.8%) in 1996 and 5 month(54.8%) in 1997, and next order at 5 month(25.8%) in 1996 and at 3 month(26.0%) in 1997. 4. Measles immunization rate was 76.1% in 1996. The rate(76.1%) by the kind of vaccine was the highest with measles-MMR(34.8%), and with MMR(32.6%) and next order with measles(8.7%). The rate by measles immunization time(month) was the highest such as 35.0% at 9 month and 10 month respectively and the rate by MMR was the highest at 16 month(35.5%), and 15 month(22.5%), 13 month (12.9%) and 14 month(12.9%) in next order.

• 대한소아치과학회지
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• 제29권4호
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• pp.607-617
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• 2002

연령과 치아 발육상태 단계와의 상관관계, 치아의 발육에 따른 치아의 이동상태를 평가하기 위하여 최근 5년 이내에 경북대학교 병원에 내원한 아동(남아 446명, 여아 326명)의 파노라마 방사선사진을 대상으로 하여, Moorrees의 기준에 의하여 하악 영구치아의 발육단계를 평가한 후, 발육단계와 연령, 치조골내 치아의 위치를 평가하여 다음과 같은 결론을 얻었다. 치아의 발육시기는 치관이 완료될 때까지 남, 여의 차이가 없었으나, 치근형성이 되면서 부터는 남아보다 여아에서 더 빨리 발육되는 경향을 나타내었다. 치관형성의 완료시점의 평균연령은 남아 여아 각각에서 중절치 3.71, 4.05세, 측절치 4.44, 4.60세, 견치 5.35, 5.11세, 제1소구치 6.62, 6.36세, 제2소구치 7.36, 7.17세, 제1대구치 3.51, 3.69세, 제2대구치 7.90, 7.64세 이었고, 치근단이 폐쇄되기 전단계인 $A_{1/2}$는 중절치 8.70, 8.18세, 측절치 9.55, 8.99세, 견치 12.48, 11.60세, 제1소구치 12.30, 12.01세, 제2소구치 12.19, 12.26세, 제1대구치 912, 8.87세, 제2대구치 12.59, 12.45세 이었다. 치조골내의 교두점 위치는 치관형성 완료시까지는 거의 변화가 없었으나, 치근이 형성됨에 따라 빠르게 교합평면을 향해 이동하였고, 치근형성 완료단계(Rc)에서 다시 움직임 없이 정체되었다. 치근단의 위치는 치관형성 시작부터 치근 1/4 형성 시까지 일정한 위치에 유지되었으나, 그 후에 급격하게 교합면 쪽으로 이동하였고, 치근 3/4 형성시점부터 비교적 일정한 위치에 유지되었다. 치아의 석회화가 시작되는 초기의 치배 위치는 견치가 가장 하방에 위치하였으며, 그 다음이 제2소구치, 제1소구치, 측절치 제2대구치, 제1대구치 순이었고, 중절치가 가장 상방에 위치하였다.

• 약학회지
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• 제48권6호
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• pp.384-390
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• 2004

Polyphenol oxidase-catalyzed oxidation of substrates (t-butylcatechol, 4-methylcatechol, chlorogenic acid, caffeic acid and pyrocatechol) were performed in the Ph range 4~8. Co ncentrations of substrate's major oxidation products were monitored by high performance liquid chromatograph. The nature and amounts of products formed were highly pH dependent. They also were ifluenced by kinds of substrates. Major oxidation product of 4-methylcatechol appeared the maxium value at pH 5, them of chlorogenic acid, caffeic acid and pyrocatechol at pH 6.0 and that of t-butylcatechol at pH 5~7. Time-dependent PPO activity was determined at $4^{\circ}C\;and\;30^{\circ}C$. PPO extracted by phosphate buffer containing triton X-114 (t-PPO) was more stable than PPO by phosphate buffer (b-PPO). The result of electrophoresis, at first PPO was showed only a band at 48 kd. After 1~3 days a partial degrade band was appeared in b-PPO and three partial degrade bands in t-PPO. No activity band was appeared in PPOs at $30^{\circ}C$ and b-PPO at $4^{\circ}C$ after 4 days. And a band (37 kDa) in t-PPO was remained finally and disappered. PPO from Perillae leaves has two activity bands at 48 and 37 kDa in previous paper. It was supposed that PPO in the leaves of Perilla frutescens was a protein having one molecular weight as 48 kDa. And 37 kDa protein, relatively proteolysis-resistant, was a proteolyzed form of a major form.

• Journal of Acupuncture Research
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• 제22권5호
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• pp.37-48
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• 2005

Objectives : The purpose of this study was to investigate the anti-caner effect of cobrotoxin on the prostatic cancer cell line(PC-3). Methods : After the treatment of PC-3 cells with cobrotoxin, we performed fluorescence microscope, MTT assay, Western blotting, Flow cytometry, PAGE electrophoresis and Surface plasmon resonance analysis to identify $NF-{\kappa}B$ the change of calcium and NO. Results : 1. The expression of $NF-{\kappa}B$ was decreased at 1nM and It·as decreased significantly at 2, 4, 8nM. 2. $I{\kappa}B,\;NF-{\kappa}B$ inhibitor, was decreased significantly at 8nM and $p-l{\kappa}Ba$, phosphrylation of $I{\kappa}B$, was decreased significantly at all concentrations of cobrotoxin. 3. The expressions of p50 and p65 were decreased significantly and dose-dependently at 1, 2, 4, 8nM. 4. The expression of p53 was increased significantly at 1, 2, 4, 8nM. 5. The calcium concentration in cell wasn't changed at 1, 2, 4, 8nM, but was increased dose-dependently at 30, 70, 130, 250nM comparing with lower dose of cobrotoxin. 6. The NO concentration in cell was increased significantly at 1, 2, 4, 8nM. 7. In immunochemical staining, we found that cobrotoxin-immunochemical complex move into intracellular space dose-dependently. Conclusion : These results indicate that cobrotoxin has anti-cancer effects by inducing apoptosis.

• Journal of Oral Medicine and Pain
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• 제39권4호
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• pp.127-132
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• 2014

Purpose: Many substances in saliva or oral health care products interact with each other. The aim of this study was to investigate interactions between hyaluronic acid (HA), lysozyme, peroxidase, and glucose oxidase (GO) in enzymatic activities at low pH levels. Methods: HA (0.5 mg/mL), hen egg-white lysozyme (HEWL, $30{\mu}g/mL$), bovine lactoperoxidase (bLPO, $25{\mu}g/mL$), and GO ($50{\mu}g/mL$) were used. The influences of HA, bLPO, and GO on HEWL activity were determined by measuring the turbidity of a Micrococcus lysodeikticus suspension. The influences of HA and HEWL on bLPO activity were determined by the NbsSCN assay, measuring the rate of oxidation of 5-thio-2-nitrobenzoic acid (Nbs) to 5,5'-dithiobis(2-nitrobenzoic acid) $(Nbs)_2$. The influences of HA and HEWL on GO activity were determined by measuring oxidized o-dianisidine production. All experiments were performed at pH 4, 5, and 6. Results: HA and GO did not affect the enzymatic activity of HEWL at pH 4, 5, and 6. bLPO enhanced the enzymatic activity of HEWL at pH 5 (p<0.05) and pH 6 (p<0.05) significantly. The enzymatic activity of bLPO was not affected by HA and HEWL at pH 4, 5, and 6. HA and HEWL did not affect the enzymatic activity of the GO at pH 4, 5, and 6. Conclusions: Peroxidase enhances lysozyme activity at low pH, otherwise there were no significant interactions in enzymatic activities between HA, lysozyme, peroxidase, and GO at low pH levels.

• 한국조리학회지
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• 제23권4호
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• pp.185-192
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• 2017

This study examined the optimum conditions and obtained the basic data for processing semi-dried sea cucumber flakes. During the boiling process, the weight and length of the sea cucumber decreased to 45.61% and 55.87%, respectively. Thereafter, there was a gradual decrease in the weight and length of the sea cucumber, which were finally maintained at 30.00% and 50.93%, respectively. The moisture content during drying was 38.37% after 3 hours at $60^{\circ}C$, and 36.56% after 5 hours at $30^{\circ}C$. However, the decrease in moisture content was slowly at 60 hours and $4^{\circ}C$, reaching a final value of 68.9%. The length of boiled sea cucumber during drying decreased to 66.35% after 11 hours at $60^{\circ}C$, and 68.90% after 24 hours at $30^{\circ}C$. The chromaticity and hardness tended to increase during the drying process. Moisture content and water activity of sea cucumber flakes decreased from 81.48% (0.963) to 33.50% (0.763), respectively, after 3 hours at $60^{\circ}C$. Following this, the moisture content and water activity continuously decreased to 30.75% (0.608) at 4 hours and 19.47% (0.437) at 5 hours, respectively. The overall acceptance score was 4.11 and 3.89 for 4 hours dry sample and 5 hours dry sample, respectively. However, the score was not statistically significant.

• Clinics in Orthopedic Surgery
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• 제10권4호
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• pp.433-438
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• 2018

Background: Cervical foraminal stenosis (CFS) is one of the degenerative changes of the cervical spine; however, correlations between the severity of stenosis and that of symptoms are not consistent in the literature. Studies to date on the prevalence of stenosis are based on images obtained from the departments treating cervical lesions, and thus patient selection bias may have occurred. The purpose of this study was to investigate the prevalence of CFS according to the site, extent, and morphology of stenosis using cervical computed tomography (CT) images obtained from patients who were visiting not because of symptoms related to the cervical spine, cervical pain, or upper limb pain. Methods: Among patients who underwent CT from January 2016 to March 2016 for reasons other than cervical spine symptoms, a total of 438 subjects were enrolled, and 2,628 cervical disc images (C4-5, C5-6, and C6-7; left and right sides) were examined. Three orthopedic surgeons performed two measurements each at 4-week intervals. Values were used for analysis if matched by more than two surgeons; if no match was found, the median values were used for analysis. The left and right sides on the same axial image were independently classified. Results: Left C5-6 stenosis was most common (24.66%) among patients. At the left C6-7, there were 20 focal types and 33 diffuse types. At bilateral C4-5 and right C6-7, the focal type was more common, whereas at bilateral C5-6 and left C6-7, the diffuse type was more common. Age and the severity of stenosis showed statistically significant correlation at all cervical levels. Conclusions: The prevalence of CFS was highest at the C5-6 level (19.06%). Compared to other levels, focal stenosis was more frequent at C4-5 and diffuse stenosis was more common at C5-6. At C6-7, the incidence of focal stenosis was higher on the right side and that of diffuse stenosis was higher on the left side.

• Korean Journal of Anesthesiology
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• 제71권6호
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• pp.459-466
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• 2018

Background: To compare the effects of intraoperative infusions of balanced electrolyte solution (BES)-based hydroxyethyl starch (HES) and saline-based albumin on metabolic acidosis and acid/base changes during major abdominal surgery conducted using Stewart's approach. Methods: Forty patients, aged 20-65 years, undergoing major abdominal surgery, were randomly assigned to the HES group (n = 20; received 500 ml of BES-based 6% HES 130/0.4) or the albumin group (n = 20; received 500 ml of normal saline-based 5% albumin). Acid-base parameters were measured and calculated using results obtained from arterial blood samples taken after anesthesia induction (T1), 2 hours after surgery commencement (T2), immediately after surgery (T3), and 1 hour after arriving at a postanesthetic care unit (T4). Results: Arterial pH in the HES group was significantly higher than that in the albumin group at T3 ($7.40{\pm}0.04$ vs. $7.38{\pm}0.04$, P = 0.043), and pH values exhibited significant intergroup difference over time (P = 0.002). Arterial pH was significantly lower at T3 and T4 in the HES group and at T2, T3, and T4 in the albumin group than at T1. Apparent strong ion difference (SIDa) was significantly lower at T2, T3, and T4 than at T1 in both groups. Total plasma weak nonvolatile acid ($A_{TOT}$) was significantly lower in the HES group than in the albumin group at T2, T3 and T4 and exhibited a significant intergroup difference over time (P < 0.001). Conclusions: BES-based 6% HES infusion was associated with lower arterial pH values at the end of surgery than saline-based 5% albumin infusion, but neither colloid caused clinically significant metabolic acidosis (defined as an arterial pH < 7.35).