• Journal of the korean academy of Pediatric Dentistry
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• v.5 no.1
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• pp.33-38
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• 1978

It has been studied that aminoacetonitrile was associated with the inhibition of collagen fiber, argyrophilic fiber and oxytalan fiber synthesis. This experiment was performed, by the basic knowledge of above mentioned study, to study on the biological effect of aminoacetonitrile to the developing periodontal ligament in Sprague Dawley rat. twenty two of female rats weighing about 200gm were gestated. In 7 days after gestation, the experimental rats were injected aminoacetonitrile 7 times intraperitoneally. After parturition, delivered fJtuses were divided into 4 groups and each group was sacrificed to 1 day, 7 days, 14 days, and 21 days after delivery, schematically. All the fetuses were observed on their periodontal ligament by histological and histo chemical methods. To study on the components of periodontal ligament fiber in these experimental study van Gieson, Masson's trichrom, argyrophilic fiber, oxytalan fiber, methyl green pyronin and periodic acid-Shiff staining were performed. Results were as follows; 1) Retardation of functional orientation in periodontal ligament collagen fiber was observed in 1 day fetuses hut this appearance was diminished gradually and recovered in normal condition in 7 days fetuses. 2) Distribution of argyrophilic fiber in 1 day fetuses was oriented delicately and loosely but volume of this fiber was gradually thickened and distributed densely. 3) Oxytalan fiber was oriented dendritic ally and contradictorily in 14 days fetuses but their orientation was changed into oblique form in middle portion of roof and their numbers were increased gradually. 4) Pyronin-philic stain of fibroblast was gradually deepened in 7 days fetuses and this finding also suggested to the depreciation of collagen synthesis in this specimen. 5) PAS positive line was observed continuousely at the portion of cervical to the middle root surface.

• The Journal of Korean Physical Therapy
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• v.21 no.1
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• pp.1-7
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• 2009

Purpose: The aim of this study was to determine the effect of proprioceptive neuromuscular facilitation (PNF) leg patterns on muscle activation of paretic and nonparetic arm in post-stroke hemiparetic subjects. Methods: Eighteen hemiparetic patients participated in this study. Each subject was asked to perform four PNF leg patterns against maximal manual resistance on nonparetic leg. EMG data were collected from biceps and triceps on the paretic and nonparetic side. The measured EMG data was digitized and processed to root mean square (RMS) and expressed as percentage maximal voluntary isometric contraction (％MVIC). The data were analyzed using paired t-test and one-way analysis of variance (ANOVA) with repeated measures to determine the statistical significance. Results: The results of this study were summarized as follows: Firstly, during four PNF patterns application, all of the ％MVIC values of biceps and triceps in paretic and nonparetic arms increased significantly compared with resting condition (p<0.05). Secondly, there was a significant difference in ％MVIC of paretic biceps between PNF leg pattern 1 and 4 (p<0.05). Conclusion: In conclusion, regardless of the kinematic components of PNF leg patterns, all of the muscle activation of biceps and triceps in paretic and nonparetic arm was significantly increased. The finding of this study indicates that irradiation effect caused by PNF leg patterns is beneficial for increased muscle activation of both paretic and nonparetic arms in post-stroke patients.

• Bulletin of the Korean Chemical Society
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• v.35 no.7
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• pp.1944-1950
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• 2014

Employment of a time consuming, sophisticated calculation using the all-atom force field and generalized-Born implicit solvent model (GBIS) for refinement of NMR structures has become practical through advances in computational methods and capacities. GBIS refinement improves the qualities of the resulting NMR structures with reduced computational times. However, the contribution of GBIS to NMR structures has not been sufficiently studied in a quantitative way. In this paper, we report the effects of GBIS on the refined NMR structures of ubiquitin (UBQ) and GB1 with subsets of distance restraints derived from experimental data. Random omission prepared a series of distance restraints 0.05, 0.1, 0.3, 0.5, and 0.7 times smaller. For each number, we produced five different restraints for statistical analysis. We then recalculated the NMR structures using CYANA software, followed by GBIS refinements using the AMBER package. GBIS improved both the precision and accuracy of all the structures, but to varied levels. The degrees of improvement were significant when the input restraints were insufficient. In particular, GBIS enabled GB1 to form an accurate structure even with distance restraints of 5%, revealing that the root-mean-square deviation was less than 1 ${\AA}$ from the X-ray backbone structure. We also showed that the efficiency of searching the conformational space was more important for finding accurate structures with the calculation of UBQ with 5% distance restraints than the number of conformations generated. Our data will provide a meaningful guideline to judge and compare the structural improvements by GBIS.

• Journal of the Ergonomics Society of Korea
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• v.32 no.6
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• pp.535-540
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• 2013

Objective: The aim of this study is to evaluate the effectiveness and efficiency of causal links between various error causes in human error analysis. Background: As finding root causes of human error in safety-critical systems is often a cognitively demanding and time-consuming task, it is particularly necessary to develop a method for improving both the quality and efficiency of the task. Although a few methods such as CREAM have suggested causal linking between error causes as a means to enhance the quality and efficiency of human error analysis, no published research to date has evaluated the performance of the causal links. Method: The performance of the CREAM links between error causes were evaluated with 80 railway accident investigation reports from the UK. From each report, errorneous actions of operators were derived, and for each error, candidate causes were found by following the predefined links. Two measures, coverage and selectivity, were used to evaluate the effectiveness and efficiency of the links, respectively. Results: On average, 96% of error causes actually included in the accident reports were found by following the causal links, and among the total of 121 possible error causes, the number of error causes to be examined further was reduced to one-tenth on average. As an additional result of this work, frequent error causes and frequently used links are provided. Conclusion: This result implies that the predefined causal links between error causes can significantly reduce the time and effort required to find the multiple levels of error causes and their causal relations without losing the quality of the results. Application: The CREAM links can be applied to human error analysis in any industry with minor modifications.

• Journal of Periodontal and Implant Science
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• v.51 no.4
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• pp.285-295
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• 2021

Purpose: The aims of the present study were 1) to quantitatively evaluate the extent of sinus pneumatization and 2) to determine the factors affecting sinus pneumatization. Methods: Based on implant treatment records, a list of patients who underwent implant placement on the posterior maxilla was obtained. Among them, patients with pre-extraction and post-extraction (before implant placement) panoramic radiographs were selected. After excluding radiographs with low resolution and image distortion, the radiographs before and after extraction were superimposed using computer software. Subsequently, the extent of sinus pneumatization (the vertical change of the sinus floor) was measured. Simple and multiple mixed models were used to determine the factors affecting sinus pneumatization. Results: A total of 145 patients were eligible for the present investigation. The average extent of sinus pneumatization was 1.56±3.93 mm at 176 tooth sites. Male sex, single tooth extraction, extraction of an endodontically compromised tooth, a class I root-sinus relationship, and sinus membrane thickening >10 mm favored pneumatization, but without statistical significance. The maxillary second molar presented the greatest pneumatization (2.25±4.39 mm) compared with other tooth types. This finding was confirmed in the multiple mixed model, which demonstrated a statistically significant impact of the extraction of a second molar compared with the extraction of a first premolar. Conclusions: Maxillary sinus pneumatization was 1.56±3.93 mm on average. The extraction of a second molar led to the greatest extent of pneumatization, which should be considered in the treatment plan for this tooth site.

• Radiation Oncology Journal
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• v.25 no.3
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• pp.185-191
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• 2007

Purpose: This study was performed to investigate the effects of immune cell activation and the antitumor effect for the combination of treatment with X-irradiation and E/eutherococcus senticosus Maxim Root (ESMR) on mouse tumor cells. Materials and Methods: ESMR (250g) was extracted with 80% methanol, concentrated under decompression and lyophilized. To determine whether ESMR is able to activate the immune cells or not, the proliferation of splenocytes in vitro and the number of B cells and T cells in splenic lymphocytes in ESMR-pretreated mice were evaluated. X-irradiation was given to the mouse fibrosarcoma tumor cells (FSa II) by 250 kv X-irradiation machine. The cytotoxicity of ESMR was evaluated from its ability to reduce the clonogenecity of FSa II cells. In X-irradiation alone group, each 2, 4, 6 and 8 Gy was given to FSa II cells. In X-irradiation with ESMR group, 0.2 mg/ml of ESMR was exposed to FSa II cells for 1 hour before X-irradiation. Results: The proliferation of cultured mouse splenocytes and thymocytes were enhanced by the addition of ESMR in vitro. The number of B cells and T cells in mouse splenic lymphocytes was significantly increased in ESMR pretreated mice in vivo. In FSa II cells that received a combination of 0.2 mg/ml of ESMR with X-irradiation exposure, the survival fraction with a dose of 2, 4 and 6 Gy was $0.39{\pm}0.005$, $0.22{\pm}0.005$ and $0.06{\pm}0.007$, respectively. For FSa II cells treated with X-irradiation alone, the survival fraction with a dose of 2, 4 and 6 Gy was $0.76{\pm}0.02$, $0.47{\pm}0.008$ and $0.37{\pm}0.01$. The difference in the survival fraction of the mouse FSa II cells treated with and without ESMR was statistically significant (p<0.05). Conclusion: Treatment with ESMR increased cell viability of mouse splenocytes in vitro and especially the subpopulation of B cells and T cells in splenocytes in ESMR-pretreated mice. However, treatment with ESMR did not increase the level of Th and Tc subpopulations in the thymocytes. Treatment with the combination of ESMR and X-irradiation was more cytotoxic to mouse tumor cells than treatment with X-irradiation alone; this finding was statistically significant.

• Journal of the Korean Society of Radiology
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• v.11 no.7
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• pp.679-685
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• 2017

Computed tomography has widely been used to diagnose patient disease, and patient dose also increase rapidly. To reduce the patient dose by CT, various techniques have been applied. The iterative reconstruction is used in view of image reconstruction. Image quality of the reconstructed section image through algebraic reconstruction technique, one of iterative reconstruction methods, was examined by the normalized root mean square error. The computer program was written with the Visual C++ under the parallel beam geometry, Shepp-Logan head phantom of $512{\times}512$ size, projections of 360, and detector-pixels of 1,024. The forward and backward projection was realized by Joseph method. The minimum NRMS of 0.108 was obtained after 10 iterations in the regularization parameter of 0.09-0.12, and the optimum image was obtained after 8 and 6 iterations for 0.1% and 0.2% noise. Variation of optimum value of the regularization parameter was observed according to the phantom used. If the ART was used in the reconstruction, the optimal value of the regularization parameter should be found in the case-by-case. By finding the optimal regularization parameter in the algebraic reconstruction technique, the reconstruction time can be reduced.