• Title/Summary/Keyword: 수치적 방법

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Effects of activators contained in adhesives on dentin bond strengths (상아질 접착제에 포함된 활성제의 사용 유무가 자가중합 복합레진의 상아질에 대한 전단결합강도에 미치는 영향)

  • Kang, Hye-Kyung;Shin, Joo-Hee;Suh, Kyu-Won;Ryu, Jae-Jun
    • The Journal of Korean Academy of Prosthodontics
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    • v.46 no.5
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    • pp.511-519
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    • 2008
  • Statement of problem: An incompatibility between the initiator systems of self-curing composite resins and light-curing adhesives was supposed recently. Purpose: The purpose of the study was to evaluate the influence of activators for self/dual bonding on dentin shear bonding strengths. Material and methods: Fifty human molars were divided into 5 groups. A flat dentin surface was created for each tooth. A self-curing composite resin (Luxacore) was bonded with the following adhesives (n = 10); One-Step, Prime&Bond NT, AdheSE, Prime&Bond NT and AdheSE were also used in combination with activators. Shear bond strengths were measured after 24 hours of water storage. The specimens were loaded in shear in the Instron until failure at a 1 mm/min crosshead speed. Data were compared using one-way ANOVA and Tukey HSD test (${\alpha}$= 0.05). Results: The dentin adhesive systems in order of decreasing median bond strength were One-Step > Prime&Bond NT with activator, AdheSE with activator > Prime&Bond NT, AdheSE. Among adhesives, One-Step had the highest bond strength. Prime&Bond NT with activator had higher bond strengths than Prime&Bond NT that was used alone, and so was AdheSE. Conclusion: Shear bond strengths were increased in Prime&Bond NT and AdheSE when these were used with activators comparing used without activators. But using activators was not effective clinically comparing One-Step.

Availability of Cardiac Troponin T as a Marker for Detecting Perioperative Myocardial Damage in Patients with Open Heart Surgery (개심술후 발생한 심근손상에서 진단 표지자로서의 Troponin T의 임상적 유용성)

  • 김태이;정태은;이동협;이정철;한승세
    • Journal of Chest Surgery
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    • v.31 no.1
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    • pp.20-27
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    • 1998
  • It is well known that troponin T(below TnT) is present in the myocardial cells and released during myocardial damage, so it`s very specific enzyme to myocardium. Availability of cardiac specific TnT in assessing perioperatively myocardial damage was evaluated from 34 open heart surgery patients. They consisted of 11 ischemic heart, 13 acquired valvular heart and 10 congenital heart cases. Patients were divided into two groups, group A(patients with myocardial damage) and group B(patients without myocardial damage), according to the symptom of chest pain suspecting angina and the ECG findings of ST segment and T wave changes which show myocardial ischemia and injury. Serum TnT levels were measured by enzyme immunoassay method preoperatively, immediately postoperatively, postoperative day 1, day 2, day 3, and day 7. We observed and analyzed the changes of serum TnT levels in two groups and compared the serum TnT levels with CK-MB levels measured at the same time. In group A, serum TnT levels showed 1.37$\pm$0.26$\mu$g/L, 3.16$\pm$0.66$\mu$g/L, 2.39$\pm$0.74$\mu$g/L, 2.49$\pm$0.76$\mu$g/L, and 1.23$\pm$0.60$\mu$g/L, immediate postoperatively, postoperatively day1, day2, day3, and day7, respectively. It was observed there were significant differences compared with those of group B(0.38$\pm$0.04$\mu$g/L, 0.34$\pm$0.05$\mu$g/L, 0.25$\pm$0.03$\mu$g/L, 0.24$\pm$0.04$\mu$g/L, and 0.11$\pm$0.03$\mu$g/L) during identical periods(P<0.01). Serum CK-MB level in group A significantly elevated to 145.04$\pm$35.08 IU/L on the postoperative day 1 compared to group B(31.28$\pm$5.87 IU/L, P<0.05), However, it stiffly decreased from day 2 and returned to preoperative level at day 3. When serum TnT level more than 1.0$\mu$g/L is thought to reflect myocardial damage, serum TnT had 100% of sensitivity and 87% of specificity in diagnosing the postoperative myocardial damage(p<0.01). I conclusion, serum TnT levels increased significantly at very early stage of myocardial damage and persisted much longer period than CK-MB. This suggests that serum TnT has more advantage and availability in assessing the perioperatively myocardial damage than any other tests.

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Effect of Maturity at Harvest on the Changes in Quality of Round Baled Rye Silage (수확시 숙기가 호밀 라운드베일 사일리지의 품질변화에 미치는 영향)

  • Kim, J.G.;Chung, E.S.;Seo, S.;Kang, W.S.;Ham, J.S.;Kim, D.A.
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.21 no.1
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    • pp.1-6
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    • 2001
  • This experiment was conducted to evaluated the effect of maturity at harvest on the changes in quality of round baled rye silage at forage experimental field of Grassland and Forage Crops Division, National Livestock Research Institute, RDA, Suwon in 1998. The experimental design was a split-plot design with three replications. The main plots were three different harvest stages : boot, heading and flowering stages, and the subplots were days after ensiling : 1, 2, 3, 5, 10, 30, 45, and 60 days. The wilting period of boot, heading and flowering stages were 1, 0.5 and 0.5 days, respectively. The final pH of rye silage was higher in the order of flowering, boot and heading stages. And pH of flowering stage began to change at early fermentation period, but that of boot and heading stages was delayed 1~2 days. Ammonia-N content of boot stage was highest. and that was increased as fermentation progressed. But Ammonia-N of heading stage was decreased to 30 days. then that was increased after 45 days fermentation. Among fermentation periods, inside temperature of deep place was not affected by external temperature. And that of deep place was increased to 3$0^{\circ}C$ at early fermentation. then decreased as fermentation progressed. However surface temperature was affected by external temperature after 10 days. Acetic acid content was not changed with 5 days by harvest stages, but that of boot stage was increased after 10 days. Butyric acid of boot stage was increased after 5 days. but that of heading stage was increased after 10 days. However lactic acid was increased from 1~2% to 6~8%. Lactic acid bacteria (LAB) of heading and flowering stages were highest at 5 days fermentation, and that of boot stage was highest at 10 days fermentation. The results of this study indicate that fermentation of round baled rye silage occur within 5 days. Therefore, any modification should be applied with an 5 days for high quality of round baled rye silage.

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Environmental Geophysical Survey of Abandoned Landfills for Contamination Evaluation: A Case Study (불량 매립지 오염평가를 위한 지구물리 탐사 사례연구)

  • Lee, Sung-Soon;Lee, Jin-Yong;Yoon, Hee-Sung;Lee, Kang-Kun;Kim, Chang-Gyun;Yu, Young-Chul
    • Journal of Korean Society of Environmental Engineers
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    • v.28 no.5
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    • pp.463-471
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    • 2006
  • Electrical resistivity surveys were conducted at areas of abandoned landfills in Cheonan and Wonju. Geology and extent of leachate migration around the landfills were evaluated with collected resistivity data by 2-D and 3-D resistivity inverse modeling. The Cheonan landfill is located above the paddy fields and the resistivity survey lines were crossed to examine possible pollution at the paddy fields by leakage of the landfill leachate. In Wonju, the landfill and the downgradient paddy fields are divided by a concrete barrier wall. At the bottom of the landfill, there is a leachate settlement system, which has not been in operation. To evaluate leachate leakage into the paddy fields, a total of 4 survey lines were used. According to the resistivity survey results, the landfill leachate in Cheonan appeared to be restricted only within the interior of the landfill, not to migrate into the subsurface of the paddy fields. These results are well consistent with electrical conductivity values of groundwaters obtained from a periodic analysis of water qualities. In Wonju, however, it was inferred that the leachate emanating from the landfill migrated beneath the abandoned leachate settlement system and the leachate would reach the downgradient paddy fields. Low resistivity area was observed in the old reservoir area and it appeared to be derived from convergence of groundwater flows from the surrounding valley and the moist wet land. In addition, groundwater flow into the paddy fields occurs beneath the old reservoir embankment at depths of $7{\sim}8m$. This paper reports details of the resistivity surveys for the uncontrolled landfills.

Negative Support Reactions of the Single Span Twin-Steel Box Girder Curved Bridges with Skew Angles (단경간 2련 강박스 거더 곡선교의 사각에 따른 부반력 특성)

  • Park, Chang Min;Lee, Hyung Joon
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.16 no.4
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    • pp.34-43
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    • 2012
  • The behaviors of the curved bridges which has been constructed in the RAMP or Interchange are very complicate and different than orthogonal bridges according to the variations of radius of curvature, skew angle and spacing of shoes. Occasionally, the camber of girder and negative reactions can be occurred due to bending and torsional moment. In this study, the effects on the negative reaction in the curved bridge were investigated on the basis of design variables such as radius of curvature, skew angle, and spacing of shoes. For this study, the twin-steel box girder curved bridge with single span which is applicable for the RAMP bridges with span length(L) of 50.0m and width of 9.0m was chosen and the structural analysis to calculate the reactions was conducted using 3-dimensional equivalent grillage system. The value of negative reaction in curved bridges depends on the plan structures of bridges, the formations of structural systems, and the boundary conditions of bearing, so, radius of curvature, skew angle, and spacing of shoes among of design variables were chosen as the parameter and the load combination according to the design standard were considered. According to the results of numerical analysis, the negative reaction in curved bridge increased with an decrease of radius of curvature, skew angle, and spacing of shoes, respectively. Also, in case of skew angle of $60^{\circ}$ the negative reaction has been always occurred without regard to ${\theta}/B$, and in case of skew angle of $75^{\circ}$ the negative reaction hasn't been occurred in ${\theta}/B$ below 0.27 with the radius of curvature of 180m and in ${\theta}/B$ below 0.32 with the radius of curvature of 250m, and in case of skew angle of $90^{\circ}$ the negative reaction hasn't been occurred in the radius of curvature over 180m and in ${\theta}/B$ below 0.38 with the radius of curvature of 130m, The results from this study indicated that occurrence of negative reaction was related to design variables such as radius of curvature, skew angle, and spacing of shoes, and the problems with the stability including negative reaction will be expected to be solved as taken into consideration of the proper combinations of design variables in design of curved bridge.

Antioxidant and Anticancer Activities of Water Extracts from Ceramium kondoi (비단풀 물 추출물의 항산화력 및 항암활성)

  • An, Deok-Ho;Cho, Seug-Ja;Jung, Eun-Sil;Lee, Hyun-Jin;Hwang, Ji-Hwan;Park, Eun-Ju;Park, Hae-Ryong;Lee, Seung-Cheol
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.10
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    • pp.1304-1308
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    • 2006
  • The present study describes the preliminary evaluation of the antioxidant activity and the cytotoxic effect of Ceramium kondoi. The antioxidant activities and cytotoxic effect of the water extracts were evaluated by total phenolic contents (TPC), DPPH radical scavenging activity (RSA), reducing power (RP), comet assay, and MTT reduction assay. TPC, DPPH RSA, and RP of the extract at the concentration of $1,000{\mu}g/mL$ was $659.2{\mu}M$, 86.0%, and 1.084, respectively, and those were concentration dependent. The $200{\mu}M\;H_2O_2-induced$DNA damage was inhibited by C. kondoi water extract in a dose dependent manner in human leukocytes. The inhibition was by 62.3, 39.8, 24.8% and 16.4% at the concentration of 5, 10, $25{\mu}g/mL$ and $50{\mu}g/mL$, respectively. Cytotoxic activity on HT-29 cells and MCF-7 cells of the C. kondoi water extract at the concentration of $10{\mu}g/mL$ was 49% and 60%, respectively. These results strongly support the possibility of C. kondoi as a source of natural functional materials.

A Comparison of the Effects of Histidine-tryptophan-ketoglutarate Solution versus Cold Blood Cardioplegic Solution on Myocardial Protection in Mitral Valve Surgery (승모판막수술 시 히스티딘를 함유한 결정성 심정지액(Histidine-tryptophan-ketoglutarate Solution)과 저온 혈성 심정지액이 심근기능 보존에 미치는 영향 비교)

  • Choi, Yong-Seon;Bang, Sou-Ouk;Chang, Byung-Chul;Lee, Sak;Park, Chol-Hee;Kwak, Young-Lan
    • Journal of Chest Surgery
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    • v.40 no.6 s.275
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    • pp.399-406
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    • 2007
  • Background: Ischemia-reperfusion injury related to unsuccessful myocardial protection affects postoperative ventricular function and mortality during open-heart surgery. We prospectively compared the effects of administration of histidine-tryptophan-ketoglutarate (HTK) solution and cold blood cardioplegia (CBC) on myocardial protection and clinical outcome in patients undergoing mitral valve surgery. Material and Method: Seventy patients with mitral regurgitation (MR) undergoing mitral valve surgery were randomly divided into the HTK group (n=31) and the CBC group (n=31 ): eight patients were excluded. Perioperative hemodynamics, cardiac medications, pacing, postoperative outcomes and complications were recorded during the hospital stay. All patients received follow-up for at least 6 months postoperatively for morbidity and mortality. Resuか: There were no significant differences in the hemodynamics between the groups during the study period, except for the mean pulmonary artery pressure (MPAP), PCWP and CVP that were lower in the HTK group at 15 min after weaning of CBP. There were no differences for inotropic support and pacing during the 12 hrs postoperatively between the groups. CK-MB values on day 1 and day 2 were $77{\pm}54$ and $41{\pm}23$ for the HTK group and $70{\pm}69$ and $44{\pm}34$ for the CBC group, respectively (p=NS). Postoperative clinical outcomes were similar in both groups for at least 6 months during the follow-up period. Conclusion: These results suggest that the use of HTK solution is as safe as cold blood cardioplegia in terms of myocardial protection.

Analysis of Treatment Failure after Curative Radiotherapy in Uterine Cervical Carcinoma (자궁경부암에 있어서 방사선치료 후의 치료실패 분석)

  • Chai, Gyu-Young;Kang, Ki-Mun;Lee, Jong-Hak
    • Radiation Oncology Journal
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    • v.19 no.3
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    • pp.224-229
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    • 2001
  • Purpose : The aim of this study is to analyze the treatment failure patterns and the risk factors for locoregional or distant failure of uterine cervical carcinoma treated with radiation therapy. Materials and methods . A retrospective analysis was undertaken of 154 patients treated with curative radiation therapy in Gyeongsang National University Hospital from April 1989 through December 1997. According to FIGO classification, 12 patients were stage IB, 24 were IIA, 98 were IIB, 1 were IIIA, 17 were IIIB, 2 were IVA. Results : Overall treatment failure rate was $42.1\%$ (65/154), and that of complete responder was $31.5\%$ (41/130). Among 65 failures, 25 failed locoregionally, another 25 failed distantly, and 15 failed locoregionally and distantly. Multivariate analysis confirmed tumor size (>4 cm) as risk factor for locoregional failure, and tumor size (>4 cm), pelvic lymph node involvement as risk factors for distant failure. Conclusion : On the basis of results of our study and recent published data of prospective randomized study for locally advanced uterine cervical carcinoma, we concluded that uterine cervical carcinoma with size more than 4 cm or pelvic lymph node involvement should be treated with concurrent chemoradiation.

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The Effect of LDL on Vibrio vulnificus Septicemia (비브리오 패혈증에 미치는 LDL의 영향)

  • Kim, Jong-Hyeon;Kim, Jong-Suk;Yoo, Wan-Hee;Hur, Hyeon
    • Journal of Food Hygiene and Safety
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    • v.21 no.4
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    • pp.213-217
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    • 2006
  • The halophilic bacterium Vibrio vulnificus is known to be a foodborne pathogen that causes septicemia in human. V. vulnificus infection is characterized by the high fatality rates and the primary attack against a person who have underlying diseases such as liver cirrhosis. However, there is no effective treatment for V. vulnificus septicemia except for classical treatments such as antibiotics. Recently, it has been known that lipoprotein (LDL) plays a major role in the protection against infection and inflammation. Consequently in this paper we analyzed the effects of LDL on V. vulnificus septicemia. We purified V. vulnificus cytolysin, a major virulent factor of V. vulnificus infection and measured inhibitory effects of mouse serum, cholesterol, and LDL on its hemolytic activity. Next experiments were performed to investigate whether LDL has a protective role against septicemia induced by V. vulnificus in mice. Intraperitoneal injection of LDL (1mg as protein) into mice 3hr before V. vulnificus $(1\times10^6\;CFU)$ injection, and V. vulnificus -induced lethality was determined. For the determination the relationship between LDL or cholesterol and prognosis, we determined serum levels of cholesterol and lipoprotein from V. vulnificus septicemia patients (n=15) who had visited the Chonbuk National University Hospital in Chonju. V. vulnificus cytolysin -induced hemolysis of mice erythrocytes was completely inhibited by serum, cholesterol, and low-density lipoprotein. V. vulnificus- induced lethality of mice injected with LDL showed only 40% compared to 100% of control. In survival groups (n=4) of V. vulnificus septicemia patients (n=15), their serum LDL and cholesterol revealed normal levels ($153.3{\pm}40.7,\;LDL;\;190.8{\pm}16.3$, Total cholesterol). However, in death groups (n=11) showed very low levels ($35.6{\pm}13.9,\;LDL;\;59.2{\pm}15.1$, Total cholesterol). Our study indicates that cholesterol and LDL are a prognosis indicator of V. vulnificus septicemia as well as an inhibitor of virulent action of V. vulnificus cytolysin. We suggested that the serum levels of cholesterol or LDL would be major index in the treatment and prevention of V. vulnificus septicemia.

In vitro Anti-hypertensive, Antioxidant and Anticoagulant Activities of Extracts from Haliotis discus hannai (전복(Haliotis discus hannai) 추출물의 혈압강하, 항산화능 및 항혈전능에 대한 in vitro 효과)

  • Kim, Hag-Lyeol;Kang, Seong-Gook;Kim, In-Chul;Kim, Seon-Jae;Kim, Du-Woon;Ma, Seung-Jin;Gao, Tiancheng;Li, Hua;Kim, Min-Jung;Lee, Tae-Hoon;Ham, Kyung-Sik
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.7
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    • pp.835-840
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    • 2006
  • The purpose of this study was to examine the in vitro effects of body and visceral portion of Haliotis discus hannai on angiotensin converting enzyme (ACE) activity and antioxidant and anticoagulant capacity. Extracts from both abalone body and visceral portion using 80% ethanol showed a high ACE-inhibitory effect. While ACE-inhibitory effect of extracts of the body part was dose-dependent, visceral extracts did not show any difference by the level of concentration. ACE-inhibitory effect of the visceral portion was much higher than that of the body. Antioxidant capacity was increased with increasing concentration of 80% ethanol body extracts although the capacity was low. The 80% ethanol visceral extracts showed a similar level of antioxidant capacity to the body extract in low concentration. Water extracts showed a dose-dependent increase in the activity. There was no significant difference in the antioxidant activity between the body and the visceral part. Anticoagulant capacity of 80% ethanol extracts, which was measured using prothrombin time(PT), was higher in the body part than the visceral part. Water extracts of Haliotis discus showed no any significant effect on anticoagulant capacity. The in vitro effects were also examined after Haliotis discus was refrigerated for 48 hours. Higher ACE-inhibitory effect was observed for the visceral portion than the body, in particular, before the sample was refrigerated. Antioxidant effect of Haliotis discus increased with increasing level of the sample before it was refrigerated. However, there was a significant difference between the body and the visceral part, which showed significantly higher capacity. There was no significant difference between the body and visceral part in PT regardless of refrigeration. While activated partial thromboplastin time (APTT) showed no significant difference between body and visceral part, there was a significant difference in the capacity between before and after the refrigeration, which showed much lower coagulant capacity.