• Journal of Dental Rehabilitation and Applied Science
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• v.18 no.2
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• pp.81-91
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• 2002

Dental implant systems have shown many post-surgical problems and One of the most frequent problem is screw loosening. To reduce screw loosening, a number of methods have been tried and recently fundamental modification of fixture-abutment connection structure was developed and used the most frequently. Former implant system structure, such as Br${\aa}$nemark, had external hex with the height of 0.7 mm and later, fixture with external hex of 1.0 mm height and internal hex structure were developed. In addition, the method of morse taper application was introduced to reduce screw loosening. In this study, the level of screw loosening of each implant systems was compared based on the vibration loosening measurement of abutment screw of each implant systems. Analysis of measured value was performed using 3 kinds of methods, (i) Percentage of average of initial 3 times loosening-torque value(initial loosening value) to tightening-torque of 30 Ncm, (ii) Percentage of loosening-torque value after 200 N strength loaded(experimental value) to initial loosening value and (iii) Percentage of experimental value to 30 Ncm of tightening-torque. Each result of analyses shows the value of initial loosening, loosening by repetitive load and final loosening level. The results of this study were as follows. (1) Percentage of initial loosening value to tightening-torque was increased in order of 0.7 mm external hex, 1.0 mm external hex, internal hex and internal taper and all values between each groups showed statistical significance (p<0.05). (2) Percentage of experimental value to initial loosening value was increased in order of internal hex, 0.7 mm external hex, 1.0 mm external hex and internal taper. Value of internal taper showed significant difference with that of 0.7 mm external hex and internal hex (p<0.05). (3) Percentage of experimental value to tightening torque was increased in order of 0.7 mm external hex, 1.0 mm external hex, internal hex and internal taper. Values of all groups showed statistical significance (p<0.05) except between the groups of 1.0 mm external hex and internal hex. Based on those results, there was no significant difference of loosening-torque by repetitive loading except internal taper. It is supposed that implant system with high resistant capability against initial loosening could be recommended for clinical use. In addition, in case of single implant restoration, 1.0 mm external hex or internal hex could be recommended rather than 0.7 mm external hex, and the use of internal taper would be the most useful way to reduce screw loosening.

• Korean Journal of Poultry Science
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• v.33 no.2
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• pp.133-139
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• 2006

This study was conducted to investigate the effects of dietary supplementation of Biotite V on growth performance, nutrients digestibility and serum and meat cholesterol in broiler chickens. A total of four hundred and eighty Arbor Acre broilers (male, 2-d-old) were used in current feeding trial for 5 weeks. Broilers were allocated to three dietary treatments with eight replications per treatment and twenty broilers per pen according to a randomized complete block design. Dietary treatments included: 1) CON (basal diet), 2) BV200 (basal diet+200 mesh Biotite V 1.5%) and 3) BV325 (basal diet+325 mesh Biotite V 1.5%). During the first week of experiment, Biotite V increased weight gain in treatment groups compared to CON treatment (P<0.05). Through the entire experimental period, weight gain, feed intake and feed/gain had no significant differences among the treatments (P>0.05). Digestibilities of DM and N were also not affected when diets included Biotite V (P>0.05). No effects were observed in Biotite V supplemented treatments compared to CON treatment on abdominal fat weight, meat and serum cholesterol concentrations (P>0.05). In conclusion, supplementation of Biotite V in broiler diets has no influence on growth performance, nutrients digestibility and can not decrease the cholesterol concentrations in meat and serum.

• Journal of the Korean Chemical Society
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• v.28 no.4
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• pp.210-216
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• 1984

Solvatochromic comparison methods were applied to determine Taft's solvent parameters, ${\pi}^{\ast}$(solvent polarity-polarizability), ${\alpha}$(solvent hydrogen bond donor acidity) and ${\beta}$ (solvent hydrogen bond acceptor basicity) for MeOH-MeCN solvent mixtures. Swain's solvent parameters A(anion solvation scale) and B(cation solvation scale) were also determined by least square fitting of kinetic data in the same binary solvent mixtures. It was found that: (i)${\beta}$ depends on the basicity of the solvent and increases with the MeOH content owing to the increase in polymeric structure of methanol; (ii) ${\pi}^{\ast}$depends on the dipole moment of the solvent and increases with the MeCN content of the solvent; (iii) ${\alpha}$ increases rapidly with the MeOH content as the hydrogen bond donor acidity of the solvent mixtures increases. Taft's reaction constants a and s and Swain's reaction constants a and b were determined for the reactions reported from our laboratory previously using solvent parameters determined in this work. No meaningful inter-relationship was found between the two set of reaction parameters, but a good linear correlation was found between the ratios a/s and a/b. Solvent effect on the reaction mechanism, substituent effect and leaving group ability were examined in the light of these reaction constants ratios.

• Journal of Environmental Health Sciences
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• v.31 no.6
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• pp.457-466
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• 2005

Industrial plasticizers such as phthalates can induce peroxisome proliferation. A growing concern among environmental and health groups has arisen because phthalates such as di-2-ethy1hexy1 phthalate (DEHP) and DBP may cause hormonal disorders, reproductive toxicity, hepatocellular tumors, genital disorders owing to a capacity to bind estrogen receptors, and a low-dose toxic action during certain periods of fetal development. Phthalate esters are used extensively as a plasticizer for plastic manufacture such as PVC bags and medical devices. This study investigated the effects of leached components from spring water container's cap and seal film. Phthalates, e.g. dimethy1 phthalate (DMP), diethy1 phthalate (DEP), di-n-buty1 phthalate (DBP), benzy1buty1 phthalate (BBP), di-(2-ethy1hexy1) phthalate (DEHP), and bisphenol A (BPA) were measured in the spring water. The bisphenol A was not detected or below the detection limit on the leaching from cap, sealing or spring water. DEHP were detected 90-116 ppb on the leaching from seal after 2 weeks, and 0.48-0.51 ppb from the spring water after I week. BBP were measured from seal within 1 week 25.4-66 ppb and below 0.12 ppb from spring water within 2 days. DMP were detected from seal within 2 weeks 51-68.5 ppb and 0.12 ppb after 2 weeks. DEP were measured from seal within 2 weeks 48.1-141 ppb and the concentrations were increased by the time from 0.10 to 0.31 ppb at spring water. DBP were detected from the seal within 2 weeks 92.3-5100 ppb and the concentration were decreased by the time from 0.24 to 0.10 ppb at spring water. These results indicate that some phthalate esters contaminated with spring water using the intact cap and seal film. It is concluded that the measured levels of phthalates leaching from these materials might in vivo only be slightly less than 1/10 of the LOAEL.

• The korean journal of orthodontics
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• v.39 no.5
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• pp.330-336
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• 2009

Objective: To examine the differences in lateral cephalometric characteristics between patients with dental protrusion and crowding in order to determine what factors affect dental protrusion or crowding while both malocclusion types are caused by large tooth size. Methods: Twenty nine individuals with dental protrusion and 22 individuals with dental crowding were enrolled in this study. All subjects had larger teeth than average and Class I molar relationships. Craniofacial characteristics and hyoid bone positions were determined from lateral cephalograms and compared between the two groups. Results: In the comparisons of craniofacial characteristics, the measurements indicating maxillary length and facial convexity showed greater values in the protrusion group than in the crowding group. Comparisons of hyoid bone positions showed that the hyoid bone was positioned more anteriorly and superiorly in the protrusion group than in the crowding group. Conclusions: The results of the present study indicate that some craniofacial characteristics and tongue position may affect the development of dental protrusion or crowding; when an individual has large teeth, dental protrusion or crowding might be determined according to maxillary growth and tongue position.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.3
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• pp.231-238
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• 2001

This study was performed to evaluate soft tissue cephalometric norms for Korean adults which can be implemented in surgical orthodontic treatment planning using selected horizontal reference plane especially for Koreans (Male: $SN-7.5^{\circ}$, Female: $SN-9.0^{\circ}$) and a simplified analytical method. 70 males and 70 females consisting of freshmen of Yonsei University from 1996 to 1997 and students from the Dental College of Yonsei University were chosen according to clinical examination and cephalometric analysis. The samples had normal profiles, normal anteroposterior skeletal relationship(ANB angle of $0^{\circ}\;to\;4^{\circ}$ and Wits appraisal of -4.0mm to 0mm), and Class I molar and canine relationship. They had no missing or supernumerary teeth and had no experience of orthodontic or prosthetic treatment. After the selection of 15 soft tissue landmarks and the construction of horizontal and vertical reference lines, 25 measurements were taken. These consisted of vertical and horizontal linear measurements and angular measurements. The results were as follows. 1. Mean and standard deviation of the measurements were calculated in males and females. 2. Vertical measurements were comparably bigger in males than females whereas anterior facial height ratio(sN-Sn/Sn-sMe) and lower anterior facial height ratio(Sn-Stms/Stmi-sMe) showed no significant difference between sexes. 3. Most of the horizontal measurements in relation to the vertical reference line(G-perpendicular) showed no significant difference between sexes. 4. Nasofacial angle, columellar angle, nasolabial angle and facial contour angle showed no significant difference between sexes. 5. The upper and lower lip were positioned about $-1.0{\pm}2.0mm$ and $+1.0{\pm}2.0mm$ in relation to the Ricketts' esthetic line in both sexes. In this study, soft tissue cephalometric norms of Korean adults for orthognathic surgery were obtained.

• Journal of Korean Medicine Rehabilitation
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• v.23 no.3
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• pp.45-53
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• 2013

Objectives The objective of present study was to investigate the effect of Ojeoksangamibang ($W\check{u}j\bar{i}s\check{a}nji\bar{a}w\grave{e}if\bar{a}ng$) extract on recovery of liver function in carbontetrachloride ($CCl_4$)-exposed rat. Methods Male rats weighing $230{\pm}7.21g$ fed experimental diet for 1 week and 28 rats were divided into 4 groups. Each of 7 rats was devided into a control group and experimental groups. We fed a control group of rats a basal diet and administered normal saline (100 mg/kg, 1 time/1 day) for 3 weeks. And we fed each experimental group of rats basal diet and administered an extract of Ojeoksangamibang extracts (100 mg/kg, 200 mg/kg, 300 mg/kg, 1 time/1 day) for 3 weeks. We measured lipid of plasma and liver, concentration of proinflammatory cytokines ($IL-1{\beta}$, IL-6 and IL-10). Statistical analysis was done by one-way analysis of variance (ANOVA) and Duncan's multiple range test with significance level at p<0.05. Results Plasma a-fetoprotein (AFP) and total protein concentration showed a tendency to decrease in Ojeoksangamibang extract-treated groups. However, plasma albumin concentration showed no significant differences in all treatment groups. Activity of plasma Aspartate aminotransferase (AST) and Alanine aminotransferase (ALT) in the Ojeoksangamibang extract-treated groups, increased addition amount of Ojeoksangamibang extracts tended to decline. Alkaline phosphatase (ALP), lactate dehydrogenase (LDH) and ${\gamma}$-glutamyl transferase (${\gamma}$-GT) activities showed a tendency to decrease in Ojeoksangamibang extract-treated groups, increased addition amount of Ojeoksangamibang extracts tended to decline. Concentration of plasma triglyceride and total cholesterol showed a lower value than that of control group. The liver $IL-1{\beta}$, IL-6 and $TNF-{\alpha}$ concentration were decreased, and IL-10 was increased in Ojeoksangamibang extract groups, compared to control group. Plasma $IL-1{\beta}$, IL-6 and $TNF-{\alpha}$ concentration were decreased, and IL-10 was increased in Ojeoksangamibang extract groups, compared to control group. Conclusions This study suggested that Ojeoksangamibang may alleviate liver inflammatory reaction induced by liver toxicity.

• Herbal Formula Science
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• v.16 no.2
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• pp.115-131
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• 2008

실험목적 : 빈소산은 11가지 생약으로 구성된 복합 한약 처방으로 관절염을 포함한 다양한 염증성 질환의 치료제로 사용되어 왔으나, 관절염에 대한 직접적인 효력평가는 찾아 보기 힘들다. 따라서 본 실험에서는 빈소산 추출물이 Freund's complete adjuvant (FCA)로 유발된 rat 류마티스성 관절염에 미치는 치료 효과를 dexamethasone (15mg/kg, 복강 투여) 의 효과와 비교 평가하였다. 실험방법 : 류마티스성 관절염은 FCA (10mg in 1ml paraffin oil 0.1ml/rats)를 좌측 후지에 피내 투여하여 유발하였다. 실험동물은 Wistar 랫트를 사용하였고, FCA 투여 14일 후 유사한 무릎관절 둘레를 나타내는 류마티스성 관절염 유발 rat와 정상 rat 및 실험군을 그룹당 9마리씩 나누었다. 실험동물은 100 또는 200mg/kg의 빈소산 추출물을 FCA 투여 14일 후부터 14일간 경구 투여하였으며, dexamethasone은 15mg/kg 농도로 복강 투여한 다음, 희생하여, 체중, 연골내 collagen 함량 및 chondroitin sulphate, heparin sulphate 및 hyaluronic acid와 같은 뼈내 glycosaminoglycan 함량의 변화를 각각 관찰하였다. 실험결과는 항염 효과가 이미 입증되어 있는 dexamethasone 15mg/kg 복강 투여군과 비교하였다. 결과 : FCA 투여는 현저한 체중, 연골내 collagen 함량 및 chondroitin sulphate, heparin sulphate 및 hyaluronic acid와 같은 뼈내 glycosaminoglycan 함량의 감소와 함께 유발 관절 둘레 및 조직내 prostaglandin $E_2$의 증가와 같은 전형적인 류마티스성 염증을 초래하였으나, 이러한 류마티스성 관절염 소견은 dexamethasone 및 모든 용량의 빈소산 추출물 투여에 의해 현저히 억제되었으며, 특히 빈소산 투여군에서는 투여 용량 의존적인 감소가 인정되었다. 결론 : 이상에서 빈소산 추출물은 투여 용량 의존적인 prostaglandin $E_2$ 억제를 매개하여 FCA 유발 류마티스성 관절염에 대한 치료 효과를 나타내는 것으로 관찰되었다. 따라서 새로운 관절염에 대한 치료제로서 개발 가능성이 있을 것으로 판단된다. 한편 빈소산 추출물은 주로 prostaglandin $E_2$ 억제작용에 의해 항염 효과를 나타내는 것으로 관찰되었으나, 금후 다른 작용기전에 대한 연구와 빈소산의 구성성분 중 유효 성분 규명을 위한 실험이 수행되어야 할 것으로 판단된다.

• Applied Microscopy
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• v.27 no.2
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• pp.121-130
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• 1997

It has been demonstrated that majority of cells in the mammalian body such as myocytes and epithelial cells of skin and intestine respond to mechanical force or environmental factors and exhibit partial disruption of cell membrane, i. e., cell wounding, even in a physiological condition. Myocardial cells are rather apt to be wounded than other cells since they are definitely exposed to mechanical stress by contraction-relaxation and blood flow. However, the mechanism how myocardial cells protect themselves against cell wounding is not yet clarified. On this background, the present study was performed to elucidate whether albumin leakage is related to cell wounding and to assess whether diltiazem, a potent calcium channel blocker, is beneficial in isoproterenol-induced cell wounding in the heart. Hearts isolated from New Zealand White rabbits ($1.5\sim2.0kg$ body weight, n=20) were perfused with Tyrode solution by Langendorff technique. After stabilization of baseline hemodynamics, the hearts were subjected to bolus administration of isoproterenol and diltiazem as following order: $1.6{\mu}M$ isoproterenol at zero min (the beginning point): $16{\mu}M$ diltiazem at 20min; $1.6{\mu}M$ isoproterenol at 25min; $16{\mu}M$ isoproterenol at 45 min; $160{\mu}M$ diltiazem at 65 min; $16{\mu}M$ isoproterenol at 70 min. During all experiments, the left ventricular function was recorded, albumin leakage in the coronary effluents was analyzed by electrophoresis and Western blot, and myocardial cell membranes were examined by conventional transmission electron microscopy. Data were analyzed by t-test and linear regression test. Isoproterenol significantly increased the inotropic and chronotropic contractions, coronary flow, and frequency of arrhythmia, however, diltiazem did not influence on hemodynamics except decrease in the frequency of arrhythmia and a slight decrease in contractility. Isoproterenol also resulted partial disruption of myocardial cell membrane and inclose in albumin leakage, while diltiazem pretreatment showed number of electron-dense plaques in the cell membrane and a tendency of decrease in albumin leakage. These results indicate that albumin leakage may be an indirect index of cell wounding in the heart and diltiazem nay be beneficial to protect myocardial cells against isoproterenol-induced cell wounding. It is likely that diltiazem promotes resealing process of the cell membrane.

• Applied Biological Chemistry
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• v.40 no.2
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• pp.128-133
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• 1997

This study was conducted to evaluate the adsorption, desorption, leaching and degradation pattern of fungicide fluazinam in the soil environment under the laboratory conditions. The mode of isothermal adsorption of fluazinam in soil was coincident with the Freundlich equation. The adsorption amount of fluazinam was much higher on soils containing organic matter than on soils oxidized with hydrogen peroxide. The presence of organic matter, humic acid or fulvic acid, increased the adsorption amount of fluazinam on soils. The Freundlich constant K was much higher in soil added with humic acid than in soil added with fulvic acid. The desorption ratio of fluazinam adsorbed to soil was increased by removal of organic matter. In leaching experiment using soil column, the fluazinam applied on the soil surface was not moved down to the bottom of soil and was not detected in leachate water. The degradation of fluazinam was faster in Soil I with rich organic matter than Soil II with poor organic matter, in non-sterilized soil than sterilized soil, and in flooded soil than unflooded soil.