• The Korean Journal of Emergency Medical Services
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• v.20 no.2
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• pp.7-19
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• 2016

Purpose: To investigate the effect of early hypothermia on post-resuscitation myocardial recovery and survival time after cardiac arrest and resuscitation in a rat model of myocardial infarction(MI). Methods: Thoracotomies were performed in 10 male Sprague Dawley rats weighing 450-455g. Myocardial infarction was induced by ligation of the left anterior descending coronary artery. Ninety minutes after arterial ligation, ventricular fibrillation was induced, cardiopulmonary resuscitation was subsequently performed before defibrillation was attempted. Animals were randomized to control group and experimental group(acute MI-normothermia)($32^{\circ}C$ for 4 hours). Duration of survival was recorded. Myocardial functions, including cardiac output, left ventricular ejection fraction, and myocardial performance index were measured using echocardiography. Results: Myocardial function was significantly better in hypothermia group than the control group during the first 4 hours post-resuscitation. The survival time of the experimental group was greater than that of the control group(p<.050). Conclusion: This study suggests that early hypothermia can attenuate post-resuscitation myocardial dysfunction after acute myocardial function, and may be a useful strategy in post-resuscitation care.

• The korean journal of orthodontics
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• v.27 no.5 s.64
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• pp.781-789
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• 1997

The purpose of this study was to evaluate the effects of fluoride relasing orthodontic sealant on the shear bond strength of light-and chemical-cured orthodontic rosins, to compare the shear bond strenth with light-and chemical-cured orthodontic resins, and to identify the changes of shear bond strength by rebonding in vitro. The brackets were divided into eight groups. Each group of metal brackets had different bonding mechanisms with adhesives. Group A : Transbond only Group B : Mono-Lok 2 only Group C : Light cured FluoroBond+Transbond Group D : Light cured FluoroBond+Mono-Lok 2 Group E : Transbond only(rebonded) Group F : Nomo-Lok 2 only(rebonded) Group G : Light cured FluoroBond+Transbond(rebonded) Group H : Light cured FluoroBond+Mono-Lok 2(rebonded) 65 extracted human premolars were prepared for bonding and 65 metal brackets for each group were bonded to prepared enamel surfaces of buccal surfaces as the above prescription. 24 hours bonding after, the Instron universal testing machine was used to test the shear bond strength of metal brackets to enamel. After debonding, same kind of metal brackets for each group were rebonded to prepared enamel surfaces of buccal surfaces to test the shear bond strength at the rebonding to enamel. Statistical analysis of the data was carried out Student's t-test ANOVA test, and Scheffe test using $SPSS/PC^+$ The results were as follows : 1. The order of shear bond strength was Group B(11.84MPa), Group A(10.75MPa), Group, D(9.69MPa), and Group C(9.39MPa)in lst bonded groups. 2. The order of shear bond strength was Group E(7.40MPa), Group G(6.48MPa), Group F(5.89MPa), and Group H(5.15MPa) in rebonded groups. 3. The shear bond strength of chemical cured orthodontic rosins had higher than that of light-cured orthodontic resins in all groups, but there was no statistical significance between groups(P>0.05). 4. In rebonded groups, the shear bond strength of light cured orthodontic rosins had higher than that of chemical cured orthodontic resins, but there was no statistical significance between groups(P>0.05). 5. The shear bond strength of all rebonded groups progressively decreased than that of 1st bonded groups, and there was statistical significance between groups(p<0.05, p<0.001).

• Korean Journal of Poultry Science
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• v.42 no.2
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• pp.147-156
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• 2015

This study was conducted to investigate the effects of dietary resveratrol on growth performance, blood biochemical parameters, immunoglobulin, and blood antioxidant activity in broiler chicks. Three hundred twenty one-day old broiler chicks were divided 8 treatments (C(-), basal diet; C(+), basal diet with antibiotics; DL-${\alpha}$-tocopherol 20 IU; DL-${\alpha}$-tocopherol 200 IU; resveratrol 20 ppm; resveratrol 200 ppm; methylated resveratrol 20 ppm; methylated resveratrol 200 ppm) with 4 replicates and 10 birds per replicate. Birds were reared for 35 days, and, at the age of 35 days, eight birds of average weight from each replicate were selected for blood samples collection. There were no significant differences on feed intake and feed conversion ratio. But final body weight and weight gain in antibiotics, resveratrol and methylated resveratrol treatments were significantly higher than no-antibiotics and ${\alpha}$-tocopherol treatments (P<0.05). There were no significant differences on carcass rate and relative organ weights among treatments, however, weights of liver and bursa of februcius in antibiotics, resveratrol and methylated resveratrol treatment were lower than other treatments. Weight of pancreas was high in resveratrol and methylated treatment. On the cecal microflora (total microbes, Coliform bacteria, Salmonella spp., and lactic acid bacteria), these in resveratrol and methylated resveratrol treatments didn't show the differences compared with those in no-antibiotics, antibiotics, and ${\alpha}$-tocopherol treatments. In the serum, there were no significant differences on creatinine, blood urea nitrogen (BUN), total protein, albumin, globulin, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) among treatments, though globulin contents of reseveratrol 200 ppm and methylated resveratrol 20 ppm treatments decreased compared to those of other treatments. Immunoglobulin (IgA, IgG and IgM) were significantly decreased in antibiotics and resveratrol treatments compared to that of no-antibiotics and ${\alpha}$-tocopherol treatments (P<0.05). Superoxide dismutase (SOD) like activity tended to increase in resveratrol groups (P<0.05), however, there was no significant difference on malondiakdehyde (MDA) content among treatments. In conclusion, these results showed that resveratrol derived from mulberry can be used as alternative of antibiotics through improvement of broiler's performance and maintain of health.

• Restorative Dentistry and Endodontics
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• v.31 no.4
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• pp.323-329
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• 2006

The aim of this study was to evaluate the retrievability of Resilon as a root canal filling material Twenty-seven human single-rooted extracted teeth were instrumented utilizing a crown down technique with Gates-Glidden burs and ProFile system. In group1 (n = 12) canals were obturated with gutta percha and AH-26 plus sealer using a continuous wave technique and backfilled. In group 2 (n = 15) Resilon was used as a filling material. Then teeth were sealed and kept in $37^{\circ}C$ and 100% humidity for 7 days. For retreatment, the samples were re-accessed and filling material was removed using Gates-Glidden burs and ProFiles. Teeth were sectioned longitudinally to compare the general cleanliness and amount of debris $({\times}\;75)$ using SEM. Chi-square test was used $({\alpha}\;=\;0.05)$ to analyze the data. The total time required for removal of filling materials was expressed as mean ${\pm}SD$ (min) and analyzed by the Student t-test $({\alpha}\;=\;0.05)$, Required time for retreatment was $3.25\;{\pm}\;0.32$ minutes for gutta percha/ AH 26 plus sealer and $3.05\;{\pm}\;0.34$ minutes for Resilon. There was no statistically significant difference between the two experimental groups. There was no significant difference between the groups in the cleanliness of the root canal wall. This study showed that Resilon was effectively removed by Gates-Glidden burs and ProFiles.

• Journal of the Korean Society of Food Culture
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• v.21 no.6
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• pp.644-652
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• 2006

This study was investigated the utilization of pomegranate(P) as coagulants for 새려 manufacture, the quality characteristics and shelf-life on tofu made by P1(fruit juice of pomegranate 1%) and P2(fruit juice of pomegranate 2%) and P3(fruit juice of pomegranate 3%) and P4(fruit juice of pomegranate 4%) and P5(fruit juice of pomegranate 5%) were investigated and compared to G.D.L(C). And also, total microbe and tatal acid of the tofu were determined during storage at $0^{\circ}C^$. The results are summarized as follow P3(493.3g/500ml) compared to C(485g/500ml) showed the highest yield. Turbidity of tofu was increased as the proportion of pomegranate was increased, while pH of tofu was increased as the proportion of pomegranate was decreased. $L^{\ast}^{\ast}^{\ast}$ value of C tofu was highest, $a^{\ast}^{\ast}^{\ast}$ value of tofu was increased as the proportion of pomegranate was increased and $b^{\ast}^{\ast}^{\ast}$ value of C tofu was higher than those of other tofus. The hardness of tofu coagulated with pomegranate showed higher than that of coagulated G.D.L. The cohesiveness of P4, P5 showed higher than C tofu, but those of other tofus showed lower than C tofu. The springiness of tofu showed in the order of P4>P5>P3>P2>P1, gumminess of P5 tofu was highest. The Brittleness of tofu was increased as the proportion of pomegranate increased. The pH value of tofu coagulated with pomegranate increased during storage at $0^{\circ}C^$. During the storage period of tofu, pH and total acid showed a maximum change in C tofu. Generally the total plate counts of bacteria of all tofu increased during storage at $0^{\circ}C^$, and those of tofu with added pomegranate were shown to be lower than C tofu. The results of S.E.M(scanning electron microscopes), the lower hardness showed the more soft and the smaller particle, The particle of C tofu was small and uniformity but the size of P4, P5 tofu showed coarse. In the sensory evaluation of all tofu, sleekness, nutty, chewiness and smoothness, appearance and overall quality was the highest in C tofu. In the sensory evaluation of tofus coagulated with pomegranate. overall quality was the highest in P2.

• Clinical and Experimental Reproductive Medicine
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• v.25 no.2
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• pp.129-134
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• 1998

The objective of this study was to test whether the developmental capacity of human multi-pronuclear (PN) zygotes after ultra-rapid freezing using EM grid can be maintained. For this experiment, multi-PN zygotes which produced in human IVF program were used as an alternatives of normal 2PN zygotes, and they were separated into 3PN or $\geq4PN$ zygotes to compare their in vitro development and cryoinjury according to PN number. As freezing solution, EFS30 which consisted of 30% ethylene glycol, 18% bcoll, 0.5 M sucrose and 10% FBS added D-PBS was used. The result obtained in this experiment was summarized as follows; When the multi..PN zygotes were ultrarapidly frozen and thawed, the high mean percentages (85.5%) were survived. Also when the cleavage rates between control and freezing group were compared with PN number, there were not significantly different in each group (3PN; 81.3% & 85.4% and $\geq4PN$; 90.0% & 95.7%). When the in vitro development rates after thawing were examined, freezing 3PN group (22.0%) was not differed to control 3PN group (38.5%), although the development result of freezing $\geq4PN$ group (45%) was significantly lower than that of control $\geq4PN$ group (44.4%) (p<0.05). These results demonstrate that developmental capacity of human zygote can be obtained by ultra-rapid freezing method using EM grid and EFS30.

• Pediatric Infection and Vaccine
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• v.29 no.3
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• pp.131-140
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• 2022

Purpose: Since the coronavirus disease 2019 (COVID-19) pandemic began, new variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have emerged, and distinct epidemic waves of COVID-19 have occurred for an extended period. This study aimed to analyze the clinical and epidemiological characteristics of children with COVID-19 from the third wave to the middle of the fourth epidemic wave in Korea. Methods: We retrospectively reviewed the medical records of hospitalized patients aged ≤18 years with laboratory-confirmed COVID-19. The study periods were divided into the third wave (from November 13, 2020 to July 6, 2021) and the fourth wave (from July 7 to October 31, 2021). Results: Ninety-three patients were included in the analysis (33 in the third and 60 in the fourth waves). Compared with the third wave, the median age of patients was significantly older during the fourth wave (6.7 vs. 2.8 years, P=0.014). Household contacts was reported in 60.2% of total patients, similar in both periods (69.7 vs. 55.0%, P=0.190). Eighty-one (87.1%) had symptomatic SARS-CoV-2 infection. Among these, 10 (12.3%) had no respiratory symptoms. Anosmia or ageusia were more commonly observed in the fourth epidemic wave (10.7 vs. 34.0%, P=0.032). Most respiratory illness were upper respiratory tract infections (94.4%, 67/71), 4 had pneumonia. The median cycle threshold values (detection threshold, 40) for RNA-dependent RNA polymerase (RdRp) and envelope (E) genes of SARS-CoV-2 were 21.3 and 19.3, respectively. There was no significant difference in viral load during 2 epidemic waves. Conclusions: There were different characteristics during the two epidemic waves of COVID-19.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.195.2-195.2
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• 2016

대기압 플라즈마는 공기중에서 방전이 가능하고, 이때 생성되는 활성산소종(ROS)과 활성질소종(RNS)을 적절히 이용하면 살균은 물론 제독이 가능하다. 특히 신경작용제나 수포작용제 등의 화학물질은 박테리아 포자, 세균, 바이러스 등의 생물작용제에 비해 더 많은 에너지와 시간이 요구된다. 현재 군이나 의료 시설에서는 과산화수소를 이용한 제독이나 염소계 표백제 성분으로 구성된 수용성 제독제를 이용하지만, 플라즈마의 경우는 단순히 기체를 방전하여 제독에 이용할 수 있으므로 보다 제독 시스템을 간단하게 구성할 수 있다. 하지만 대기압 방전시 방전전압을 낮추기 위해 헬륨과 알곤등의 기체를 공급하여 사용할 경우 부가적인 시스템의 규모가 커져 활용에 제한이 따른다. 따라서 본 연구에서는 대기중에 존재하는 질소, 산소 등을 이온화시키기 위해 10-25kHz의 주파수에서 4.5kV의 8us 펄스전원을 인가하여 공기 플라즈마를 얻고, 열에 의한 분해효과를 제거하기 위해 플라즈마의 기체온도를 20도로 유지시켰다. 플라즈마의 특성은 방출광 분석법을 이용하여 떨림온도를 계산하였고, 질소와 오존의 농도를 동시에 관찰하였다. 분해된 화학작용제는 기체분석기(Gas Chromatography)를 통해 표준 오염농도대비 잔류한 양을 측정함으로써 제독효율을 계산하였다.

• The korean journal of orthodontics
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• v.30 no.5 s.82
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• pp.535-542
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• 2000

The purpose of this study was to find the characteristics of the frontal natural head position(NHP) of patients with facial asymmetry, and to contribute to the diagnosis of facial asymmetry in the clinical examination of orthodontic patients. Twenty adult patients who had apparent facial asymmetry and no severe sagittal skeletal discrepancy were selected as the asymmetry group, and 21 young adults who had symmetric faces were selected as the symmetry group. Frontal cephalograms were obtained in the state of NHP using a pivot-mounted fluid level device. The degree of the menton deviation was defined as the angle between the line drawn through crista galli and anterior nasal spine and the line drawn through crista galli and menton. The following angles were measured and each of them was compared with the degree of the menton deviation one is the angle between the true vertical line and the supra-orbital line which is a tangent line to the extreme cranial point on the supra-orbital margin, and the other is the angle between the true vertical line and the cervical line drawn through the midpoint of atlas and the 4th cervical vertebra. Through the statistical analysis, following results were obtained. 1. The angle between the supra-orbital line and the true vertical line was much mote deviated from the right angle in the asymmetry group than in the symmetry group. 2. The angle between the cervical line and the true vertical line in the asymmetry group showed greater tendency than in the symmetry group, but the difference was not statistically significant. 3. In the asymmetry group, the degree of the menton deviation was positively correlated with the angle between the supraorbital line and the true vertical line. The above results suggest that racial asymmetry patients show the tendency to have the tilted NHP to compensate the deviation of menton position.

• Journal of Dental Rehabilitation and Applied Science
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• v.29 no.3
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• pp.209-223
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• 2013

This study was to evaluate the stress distributions of prefabricated, customized abutments and fixtures according to their material and shape by three-dimensional finite element analysis. And to investigate the fatigue life and fracture characteristics. Mandibular models were fabricated by reconstruction of the CT scan of patients with normal occlusion. A total of six finite element models were designed, a load of 100 N was applied on the buccal cusps vertically, and 30 degree obliquely. 10 specimens each were fabricated for the more clinically widely used 4 type abutments and were loaded according to ISO 14801. Differences in stress distribution patterns were not found according to the materials of the abutments and fixtures. But a slight difference in the stress level was detected. Customized abutment groups showed lower crown stress levels. One-piece zirconia implant showed the lowest bone stress levels. In the fatigue test, highest values were measured in group 7. Prefabricated abutments showed less variation of fatigue life (P<0.05). Use of customized abutments can improve the fracture resistance of restorations. Especially, use of customized zirconia abutments reinforced by titanium screw connecting parts is recommended.