• The Journal of Korean Academy of Prosthodontics
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• v.47 no.1
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• pp.53-60
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• 2009

Statement of problem: At present, as the esthetic demands are on the increase, there are many ongoing studies for tooth-colored post and cores. Most of them are about fiber post and prefabricated zirconia post, but few about one-piece milled zirconia post and core using CAD/CAM (computer-aided design/computer-aided manufacturing) technique. Purpose: The objective of this study was to compare microleakage of endodontically treated teeth restored with three different tooth-colored post and cores. Material and methods: Extracted 27 human maxillary incisors were cut at the cementoenamel junction, and the teeth were endodontically treated. Teeth were divided into 3 groups (n=9); restored with fiber post and resin core, prefabricated zirconia post and heat-pressed ceramic core, and CAD/CAM milled zirconia post and core. After the preparation of post space, each post was cemented with dual-polymerized resin cement (Variolink II). Teeth were thermocycled for 1000 cycles between $5-55^{\circ}C$ and dyed in 2% methylene blue at $37^{\circ}C$ for 24 hours. Teeth were sectioned (bucco-lingual), kept the record of microleakage and then image-analyzed using a microscope and computer program. The data were analyzed by one-way ANOVA and Scheffe's multiple range test (${\alpha}=0.05$). Results: All groups showed microleakage and there were no significant differences among the groups (P>.05). Prefabricated zirconia post and heat-pressed ceramic core showed more leakage in dye penetration at the post-tooth margin, but there was little microleakage at the end of the post. Fiber post and resin core group and CAD/CAM milled zirconia post and core group indicated similar microleakage score in each stage. Conclusion: Prefabricated zirconia post and heat-pressed ceramic core group demonstrated better resistance to leakage, and fiber post and resin core group and CAD/CAM milled zirconia post and core group showed the similar patterns. The ANOVA test didn't indicate significant differences in microleakage among test groups. (P>.05)

• Applied Biological Chemistry
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• v.43 no.1
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• pp.52-56
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• 2000

The influence of the 2-(4-(6-chloro-2-benzoxazolyloxy)phenoxy)-N-phenyl- propionamide derivatives on the herbicide activities against rice plant with pre-emergence and post-emergence in down land were examined and the structure activity relationship (SAR) were analyzed by Free-Wilson and Hansch method. In pre-emergence, the SAR approach is shown that the optimal, $({\pi})_{opt}=0.91$, hydrophobicity with electron donating effect of the ortho substituted mono substituents and 2,3,4-substituted three substituents were found to be contribute the herbicidal activity. Whereas, in post-emergence, the optimal, ({\pi})_{opt}=0.50$, hydrophobicity with electron withdrawing effect of meta substituted mono subsituents and 2,3-substituted two substituents were found to be contribute the herbicide activity. The herbicide activities with post-emergence more increase than that of pre-emergence. It is assumed from the SAR equations that the 2-methyl-3-methoxy-4-cyano group substituent is selected as the most lowest herbicide activity against rice plant with post-emergence in green house. The hydrolysis reaction was proceeded through nucleophilic addition-elimination (Ad_{Nu-E})$ with the orbital control between LUMO of substrate and HOMO of water molecule. And molecular electrostatic potential (MEP) of none (H) substituent was discussed.

• The Journal of Korean Academy of Prosthodontics
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• v.32 no.1
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• pp.1-8
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• 1994

The purpose of this study was to evaluate the effect of the canal filling sealer to resin cement When posts were cemented in the endodontically treated teeth, 86 incisors were used. The coronal portion of the teeth were removed at the cemento-enamel junction, every tooth was done treatment of canal. And the teeth was divided was into 12 groups. G : I a n : 7 Treatment : Z.P.C (1 day after Z.O.E. sealer) G : I b n : 7 Treatment : All-Bond (3 day after sealer) G : II a n : 8 Treatemt : Z.P.C (3 day after sealer) G : II b n : 7 Treatemt : All-Bond (3 day after sealer) G : III a n : 8 Treatemt : Z.P.C (7 day after sealer) G : III b n : 8 Treatemt : All-Bond (7 day after sealer) G : IV a n : 7 Treatemt : Z.P.C (1 day after Apexit sealer) G : IV b n : 7 Treatemt : All-Bond (1 day after sealer) G : V a n : 7 Treatemt : Z.P.C (3 day after sealer) G : V b n : 7 Treatemt : All-Bond (3 day after sealer) G : VI a n : 7 Treatemt : Z.P.C (7 day after sealer) G : VI a n : 7 Treatemt : All-Bond (7 day after sealer) Ready made stainless steel Para-post(PD-K-3) was cemented with Z.P.C. in subgroup a, and cemented with All-Bond & composite resin cement in subgroup b to depth 7mm. After 5 days at cementation of post, teeth with cemented posts were mounted on a retention jig and the failure loads of the specimens were measured by an Instron Universal Testing Machine. The results were as follows. 1. The results of failure loads were $15.5{\pm}7.1kg$ in group I b, $21.6{\pm}5.4kg$ in group II b and $20.1{\pm}18.1kg$ in group III b, and there was no statistically significant , difference between each group(p>0.05). 2. The results of failure loads were $19.0{\pm}6.7kg$ in group IV b, $17.3{\pm}6.5kg$ in group V b.and $18.9{\pm}7.9kg$ in group VI b and there was no significant difference between each other(p>0.05). 3. In same condition, the failure load of subgroup a was largely higher the subgroup b. But there was no significant difference between each other(p>0.05).

• Computers and Concrete
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• v.7 no.2
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• pp.159-167
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• 2010

This paper demonstrates numerical techniques for complex large-scale modeling with microplane constitutive theories for reinforced high strength concrete, which for these applications, is defined to be around the 7000 psi (48 MPa) strength as frequently found in protective structural design. Applications involve highly impulsive loads, such as an explosive detonation or impact-penetration event. These capabilities were implemented into the authors' finite element code, ParaAble and the PRONTO 3D code from Sandia National Laboratories. All materials are explicitly modeled with eight-noded hexahedral elements. The concrete is modeled with a microplane constitutive theory, the reinforcing steel is modeled with the Johnson-Cook model, and the high explosive material is modeled with a JWL equation of state and a programmed burn model. Damage evolution, which can be used for erosion of elements and/or for post-analysis examination of damage, is extracted from the microplane predictions and computed by a modified Holmquist-Johnson-Cook approach that relates damage to levels of inelastic strain increment and pressure. Computation is performed with MPI on parallel processors. Several practical analyses demonstrate that large-scale analyses of this type can be reasonably run on large parallel computing systems.

• Journal of the Korean Society of Physical Medicine
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• v.19 no.2
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• pp.107-122
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• 2024

PURPOSE: This study examined sports injuries among national sitting volleyball players and to provide baseline data for the development of programs to prevent injuries and enhance performance. METHODS: The study surveyed 21 national team athletes (12 males and nine females) participating in the 4^th Hangzhou Asian Para Games. The questionnaire consisted of 17 items, including general information, type of disability, sites and types of sports injuries and their causes, the current state of sports injuries and the treatment and management of injuries. RESULTS: The survey results suggested that the most common injury sites were the finger, shoulder, and waist. The most frequent types of injuries were sprain, muscle cramp, and LBP. The causes were insufficient warm-up, playing unhealed and carelessness. Injuries were most prevalent during morning training and in the winter. Most injuries occurred in practice, and the actions most likely to cause injuries were blocking, spike and sitting movements. Ice and spray were the most common treatments, usually administered by the athletes themselves. Physical therapy was the most common post-injury management, and the most common sequelae involved continuing to use despite pain. CONCLUSION: Based on these results, systematic and individualized training and therapeutic support tailored to the characteristics of sitting volleyball and the types of disabilities are necessary to prevent and manage sports injuries among national players. Continuous injury management by medical staff, particularly physical therapists, is essential to maintain the health of disabled athletes.

• Journal of Oriental Neuropsychiatry
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• v.21 no.2
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• pp.87-101
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• 2010

Objectives : The aim of this experiment was to investigate the influences of Autonomic Nervous System and EEG by conducting Reinforcement-Reduction(補瀉) acupuncture stimulation to compare the changes in acupoints on the body before and after treatment of acupuncture at Xingjian(LR2) being referred as Fire-point(火穴) and Ququan(LR8) being referred as Water-point(水穴) of Yin Liver Meridian(足厥陰肝經). Methods : This study was carried out on 30 healthy female volunteers in their 20's. There were four tests conducted throughout and the period for each test was between 2 to 5days. HRV and EEG were measured for 5 minutes before acupuncture stimulation was conducted on LR2-Reinforcement, LR2-Reduction, LR8-Reinforcement and LR8-Reduction at random. During the 20 minutes of acupuncture treatment, same subjects were measured simultaneously to observe any significant changes in acupoints. Again, the same subjects were measured for 5 minutes after removing the acupuncture in order to perform a comparative analysis. Results : The measurement of HRV showed that LF, LFnorm and LF/HF ratio increased significantly(p<0.05) while HF, HF norm decreased significantly in case of LR2-Reinforcement & LR8-Reduction. Both LR2-Reduction and LR8-Reinforcement induced a significant increase in HFnorm. EEG measurement indicated low $\alpha$ wave decreased and high $\beta$ wave increased significantly at LR2-Reinforcement during post-acupuncture period compared with acupuncture stimulation period. Both LR2-Reduction and LR8-Reinforcement developed significantly low $\alpha$ wave and high $\alpha$ wave. High $\beta$ wave increased significantly at LR8-Reduction during the acupuncture stimulation in comparison with pre-acupuncture period. Conclusions : The manipulation of acupuncture stimulation at LR2-Reinforcement and LR8-Reduction enhanced the activity of sympathetic nerves and the state of arousal while that of para sympathetic nerves declined. On the other hand, LR2-Reduction and LR8-Reinforcement developed the levels of para sympathetic nerves and relaxation.

• Tunnel and Underground Space
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• v.30 no.6
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• pp.509-518
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• 2020

This study constructed a new simulation platform, including mesh generation process, numerical simulation, and post-processing for results analysis based on exploration data to perform real-scale numerical analysis considering the actual geological structure efficiently. To build the simulation platform, we applied for open-source programs. The source code is open to be available for code modification according to the researcher's needs and compatibility with various numerical simulation programs. First, a three-dimensional model(3D) is acquired based on the exploration data obtained using a drone. Then, the domain's mesh density was adjusted to an interpretable level using Blender, the free and open-source 3D creation suite. The next step is to create a 3D numerical model by creating a tetrahedral volume mesh inside the domain using Gmsh, a finite element mesh generation program. To use the mesh information obtained through Gmsh in a numerical simulation program, a converting process to conform to the program's mesh creation protocol is required. We applied a Python code for the procedure. After we completed the stability analysis, we have created various visualization of the study using ParaView, another open-source visualization and data analysis program. We successfully performed a preliminary stability analysis on the full-scale Dokdo model based on drone-acquired data to confirm the usefulness of the proposed platform. The proposed simulation platform in this study can be of various analysis processes in future research.

• Journal of Gastric Cancer
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• v.20 no.3
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• pp.233-244
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• 2020

Purpose: For unresectable or initially metastatic gastric cancer, conversion surgery (CVS), after systemic chemotherapy, has received attention as a treatment strategy. This study evaluated the prognostic value of ypTNM stage and the oncologic outcomes in patients receiving CVS. Materials and Methods: A retrospective review of clinicopathologic findings and oncologic outcomes of 116 patients who underwent CVS with curative intent, after combination chemotherapy, between January 2000 and December 2015, has been reported here. Results: Twenty-six patients (22.4%) underwent combined resection of another organ and 12 patients received para-aortic lymphadenectomy (10.3%). Pathologic complete remission (CR) was confirmed in 11 cases (9.5%). The median overall survival (OS) and disease-free survival (DFS) times were 35.0 and 21.3 months, respectively. In multivariate analysis, ypTNM stage was the sole independent prognostic factor for DFS (P=0.042). Tumors invading an adjacent organ or involving distant lymph nodes showed better survival than those with peritoneal seeding or solid organ metastasis (P=0.084). Kaplan-Meier curves showed that the 3-year OS rate of patients with pathologic CR and those with CR of the primary tumor but residual node metastasis was 81.8% and 80.0%, respectively. OS was 65.8% for stage 1 patients, 49.8% for those at stage 2, and 36.3% for those at stage 3. Conclusions: The ypTNM staging is a significant prognostic factor in patients who underwent CVS for localized unresectable or stage IV gastric cancers. Patients with locally advanced but unresectable lesions or with tumors with distant nodal metastasis may be good candidates for CVS.

• Preventive Nutrition and Food Science
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• v.7 no.2
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• pp.168-173
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• 2002

Gastrointestinal infections kill over two million people each year, and pathogen contamination of livestock causes many cases of food poisoning. Two candidate intestinal probiotic strains, L. rhamnosus GR-1 and L. fermentum RC-14 were found to inhibit the growth of Salmonella typhi, Shigella dysenteriae, E. coli O157:H7, Listeria monocytogenes, L. innocua, Enterococcus faecalis, and Bacteroides fragilis. In a series of mouse experiments, L. rhamosus GR-1 and L rhamnosus GG protected against S. typhimurium infection and translocation to the liver and spleen, reduced mortality and induced intestinal phagocytic and immunoglobulin responses. In a second series of experiments, the combination of L. rhamnosus GR-1 and L. fermentum RC-14 was superior to L. rhamnosus GG and placebo in protecting the mice from the lethal effect of salmonella. In summary, the use of combinations of probiotic lactobacilli as dietary supplements or foods could be considered for people at high risk of salmonella intestinal infection. Given the post-infection complications that can arise, such natural methods warrant further exploration especially given the increasing problem of antibiotic resistance and the lack of alternative measures available to many developing countries.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.2
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• pp.97-108
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• 2015

In the design of sailing yachts, para-glider, or high-sky wind power, etc., the analysis of side-wind aerodynamic forces exerted on a cambered 3-D model is very important to predict the performance of various machinery systems. To understand the essential flow physics around the three-dimensional shape, simplified rigid-body models are proposed in this study. Four parameters such as free stream velocity, angle of attack, aspect ratio, and camber are considered as the independent variables. Lift and drag coefficients are computed with CFD technique using ANSYS-CFX, and the results with the visualization of post-processed flow fields are analyzed in the viewpoint of fluid dynamics.