• Journal of radiological science and technology
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• v.29 no.4
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• pp.257-260
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• 2006

In order to evaluate the exposure to the radiologic technologists from patients who had been administrated with radiopharmaceuticals, we measured the spatial dose rates at $5{\sim}300\;cm$ from skin surface of patients using an proportional digital surveymeter, 1.5(PET scan) and 4hr(bone scan) after injection. In results, the exposure to the technologists in each procedure was small, compared with the dose limits of the medical workers. However, the dose-response relationships in cancer and hereditary effects, referred to as the stochastic effects, have been assumed linear and no threshold models ; therefore, the exposure should be minimized. For this purpose, the measurements of spatial dose rate distributions were thought to be useful.

• Journal of Preventive Medicine and Public Health
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• v.33 no.2
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• pp.165-173
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• 2000

Objectives : To assess the availability of the glycophorin A (GPA) assay to detect the biological effect of ionizing radiation in workers exposed to low-doses of radiation. Methods : Information on confounding factors, such as age and cigarette smoking was obtained on 144 nuclear power plant workers and 32 hospital workers, by a self-administered questionnaire. Information on physical exposure levels was obtained from the registries of radiation exposure monitoring and control at each facility. The GPA mutant assay was performed using the BR6 method with modification by using a FACScan flow cytometer. Results : As confounders, age and cigarette smoking habits showed increasing trends with GPA variants, but these were of no statistical significance. Hospital workers showed a higher frequency of the GPA variant than nuclear power plant workers in terms of the NO variant. Significant dose-response relationships were obtained from in simple and multiple linear regression models. The slope of the regression equation for nuclear power plant workers was much smaller than that of hospital workers. These findings suggest that there may be apparent dose-rate effects. Conclusion : In population exposed to chronic low-dose radiation, the GPA assay has a potential to be used as an effective biologic marker for assessing the bone marrow cumulative exposure dose.

• Imaging Science in Dentistry
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• v.43 no.4
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• pp.219-225
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• 2013

Purpose: The purpose of this study was to determine the prevalence of missing and impacted third molars in people aged 25 years and above. Materials and Methods: The study sample of 3,799 patients was chosen randomly from patients who visited Pusan National University Dental Hospital and had panoramic radiographs taken. The data collected included presence and impaction state, angulation, and depth of impaction of third molars, and radiographically detected lesions of third molars and adjacent second molars. Results: A greater percentage of men than women retained at least one third molar. The incidence of third molars decreased with increasing age. The incidence of partially impacted third molars greatly declined after the age of 30. Vertically impacted maxillary third molars and horizontally impacted mandibular third molars were most frequent in all age groups. Among the maxillary third molars, those impacted below the cervical line of the second molar were most frequent in all age groups, and among the mandibular third molars, deeply impacted third molars were most frequent in those aged over 40. Dental caries was the most common radiographic lesion of the third molars. Mesioangularly impacted third molars showed radiographic lesions in 13 (9.5%) adjacent maxillary second molars and 117 (27.4%) mandibular second molars. Conclusion: The number of remaining third molars decreased and the percentage of Class C depth increased with age. Caries was the most frequent lesion in third molars. Partially impacted mesioangular third molars showed a high incidence of caries or periodontal bone loss of the adjacent second molar. Regular oral examination will be essential to keep asymptomatic third molars in good health.

• Journal of Periodontal and Implant Science
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• v.50 no.3
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• pp.183-196
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• 2020

Purpose: This practice-based cross-sectional study aimed to investigate whether common risk indicators for peri-implant diseases were associated with peri-implant mucositis and peri-implantitis in patients undergoing supportive implant therapy (SIT) at least 5 years after implant restoration. Methods: Patients exclusively restored with a single implant type were included. Probing pocket depth (PPD), bleeding on probing (BOP), suppuration, and radiographic bone loss (RBL) were assessed around implants. The case definitions were as follows: peri-implant mucositis: PPD ≥4 mm, BOP, no RBL; and peri-implantitis: PPD ≥5 mm, BOP, RBL ≥3.5 mm. Possible risk indicators were compared between patients with and without mucositis and peri-implantitis using the Fisher exact test and the Wilcoxon rank-sum test, as well as a multiple logistic regression model for variables showing significance (P<0.05). Results: Eighty-four patients with 169 implants (observational period: 5.8±0.86 years) were included. A patient-based prevalence of 52% for peri-implant mucositis and 18% for peri-implantitis was detected. The presence of 3 or more implants (odds ratio [OR], 4.43; 95 confidence interval [CI], 1.36-15.05; P=0.0136) was significantly associated with an increased risk for mucositis. Smoking was significantly associated with an increased risk for peri-implantitis (OR, 5.89; 95% CI, 1.27-24.58; P=0.0231), while the presence of keratinized mucosa around implants was associated with a lower risk for peri-implantitis (OR, 0.05; 95% CI, 0.01-0.25; P<0.001). Conclusions: The number of implants should be considered in strategies to prevent mucositis. Furthermore, smoking and the absence of keratinized mucosa were the strongest risk indicators for peri-implantitis in patients undergoing SIT in the present study.

• Journal of Veterinary Clinics
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• v.27 no.5
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• pp.579-583
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• 2010

An 18-month-old intact male Pomeranian dog was presented because of traumatic head injury from a fall. Based on physical and neurological examination, brain injury was suspected. On plain skull radiographs, bony fragment following fracture was identified in the region of the right occipital bone. On computed tomography (CT) images, there were specific findings associated with an intracranial hemorrhage. The patient expired few hours after diagnosis, and performed necropsy. On gross findings, intracerebral hemorrhage and edema was detected and those were consistent with CT images. This report describes the clinical findings, CT imaging characteristics, necropsy findings, and histopathologic features of severe traumatic brain injury in a dog.

• Journal of Microbiology and Biotechnology
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• v.28 no.6
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• pp.860-873
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• 2018

Although ginseng marc is a by-product obtained during manufacturing of various commercial ginseng products and has been routinely discarded as a waste, it still contains considerable amounts of potential bioactive compounds, including saponins and polysaccharides. Previously, we reported that ginseng oligosaccharides derived from ginseng marc polysaccharides by enzymatic hydrolysis exert immunostimulatory activities in macrophages and these activated macrophages are in turn able to inhibit the growth of skin melanoma cells by inducing apoptosis. In the present study, a more detailed investigation of the immunostimulatory activity and underlying action mechanisms of an enzymatic hydrolysate (GEH) containing these oligosaccharides derived from ginseng marc polysaccharides was performed. The levels of proinflammatory cytokines and anti-inflammatory cytokines were measured in GEH-stimulated RAW264.7 macrophages using RT-PCR analysis and ELISA. The expression levels of Toll-like receptor 2 (TLR2) and TLR4, Dectin-1, and MerTK were measured by RT-PCR analysis or western blot analysis, and the phagocytic activities of GEH-challenged bone marrow-derived macrophages toward apoptotic Jurkat cells were assayed using fluorescence microscopy. GEH induced the production of both proinflammatory cytokines $TNF-{\alpha}$ and IL-6, and anti-inflammatory cytokine IL-10 in RAW 264.7 cells. The expression of the TLR2 and MerTK mRNAs was increased upon GEH treatment. Phagocytosis of apoptotic Jurkat cells was enhanced in GEH-treated macrophages. Based on the results, this enzymatic hydrolysate (GEH) containing oligosaccharides exerts immunostimulatory effects by maintaining the balance between M1 and M2 cytokines, facilitating macrophage activation and contributing to the efficient phagocytosis of apoptotic cells. Therefore, the GEH could be developed as value-added, health-beneficial food materials with immunostimulatory effects.

• The korean journal of orthodontics
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• v.46 no.5
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• pp.290-300
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• 2016

Objective: This study aimed to (1) evaluate the effects of maxillary second and third molar eruption status on the distalization of first molars with a modified palatal anchorage plate (MPAP), and (2) compare the results to the outcomes of the use of a pendulum and that of a headgear using three-dimensional finite element analysis. Methods: Three eruption stages were established: an erupting second molar at the cervical one-third of the first molar root (Stage 1), a fully erupted second molar (Stage 2), and an erupting third molar at the cervical one-third of the second molar root (Stage 3). Retraction forces were applied via three anchorage appliance models: an MPAP with bracket and archwire, a bone-anchored pendulum appliance, and cervical-pull headgear. Results: An MPAP showed greater root movement of the first molar than crown movement, and this was more noticeable in Stages 2 and 3. With the other devices, the first molar showed distal tipping. Transversely, the first molar had mesial-out rotation with headgear and mesial-in rotation with the other devices. Vertically, the first molar was intruded with an MPAP, and extruded with the other appliances. Conclusions: The second molar eruption stage had an effect on molar distalization, but the third molar follicle had no effect. The application of an MPAP may be an effective treatment option for maxillary molar distalization.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.16 no.1
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• pp.1-8
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• 2010

Purpose : This study aimed to examine the relationships among five clinical measures for functional alignment of the lower extremity. Methods : Thirty healthy subjects (15 males and 15 females) were recruited for the study. The five clinical measures of functional alignment of the lower extremity included navicular drop, quadriceps angle, internal rotation of hip, and anterior and lateral pelvic tilt angles. The level of navicular drop was calculated by the difference between the height of the navicular bone in the sitting (non-weight bearing) and standing (weight bearing) positions. The quadriceps angle and internal rotation of hip were measured using a standard goniometer with photographic markers while the subjects were lying in a prone position on a table with their knee at $90^{\circ}$ flexion. Anterior and lateral pelvic tilt angles were determined using a inclinometer. Results : Correlation and a simple linear regression analysis were used to assess relationships between the clinical measures. There were significant correlations between navicular drop and quadriceps angle (p<.05), between navicular drop and internal rotation of hip (p<.05), and between quadriceps angle and internal rotation of hip (p<.01). In simple linear regression analysis, the navicular drop appeared to be a factor affecting the quadriceps angle and internal rotation of hip (p<.05). The findings suggest that navicular drop has a great impact on lower extremity alignment. Conclusion : This study might help us to examine lower extremity function and clarify its role as a potential injury risk factor.

• The Journal of Korean Academy of Prosthodontics
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• v.54 no.1
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• pp.21-27
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• 2016

In removable dental prostheses, it is important to minimize impairment of residual tissue caused by wearing dentures. There are two factors that harm residual tissue. The first is functional load bearing of remaining teeth and alveolar ridges and the second is the effect of poor oral hygiene. Double crown retained removable dental prostheses provide rigid support, and it may reduce impairment caused by load bearing of alveolar ridges. Also, dental plaque and oral deposits, which are attached to outer crowns and dentures, can be easily managed extra-orally. In addition, it is beneficial to the health of the marginal gingiva because inner crowns have easy access for oral hygiene. In this case, double crown retained removable dental prostheses were used for the partially edentulous patient with severe residual alveolar bone resorption and poor oral hygiene, and the result was clinically satisfactory in terms of functional, esthetical, and oral hygiene aspects.

• Journal of Radiation Protection and Research
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• v.43 no.1
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• pp.1-9
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• 2018

Background: In this study, we investigate the image quality of virtual monochromatic images synthesized from dual-energy computed tomography (DECT) at voltages of 80/140 kV and 100/140 kV. Materials and Methods: Virtual monochromatic images of a phantom are synthesized from DECT scans from 40 to 70 keV in steps of 1 keV under the two combinations of tube voltages. The dose allocation of dual-energy (DE) scan is 50% for both low- and high-energy tubes. The virtual monochromatic images are compared to single-energy (SE) images at the same radiation dose. In the DE images, noise is reduced using the 100/140 kV scan at the optimal monochromatic energy. Virtual monochromatic images are reconstructed from 40 to 70 keV in 1-keV increments and analyzed using two quality indexes: noise and contrast-to-noise ratio (CNR). Results and Discussion: The DE scan mode with the 100/140 kV protocol achieved a better maximum CNR compared to the 80/140 kV protocol for various materials, except for adipose and brain. Image noise is reduced with the 100/140 kV protocol. The CNR values of DE with the 100/140 kV protocol is similar to or higher than that of SE at 120 kV at the same radiation dose. Furthermore, the maximum CNR with the 100/140 kV protocol is similar to or higher than that of the SE scan at 120 kV. Conclusion: It was found that the CNR achieved with the 100/140 kV protocol was better than that with the 80/140 kV protocol at optimal monochromatic energies. Virtual monochromatic imaging using the 100/140 kV protocol could be considered for application in breast, brain, lung, liver, and bone CT in accordance with the CNR results.