• The Journal of Korean Academy of Prosthodontics
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• v.54 no.2
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• pp.120-125
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• 2016

Purpose: The purpose of this study is to identify the effect of mesenchymal stem cell proliferation on recombinant human transforming growth factor-beta (rhTGF-${\beta}2$) / poly (D,L-lactide-co-glycolide) (PLGA) treated titanium discs by electrospray. Materials and methods: Anodized titanium surface coated with PLGA was used for a control group to compare anodized titanium surface coated with 125 ng/ml and 500 ng/ml rhTGF-${\beta}2$ as test groups. Atomic force microscope (AFM) test was utilized to determine the difference in coating surface roughness, and field-emission scanning electron microscopy (FE-SEM) was taken to visualize even distribution of coating particles on titanium discs. The mesenchymal stem cell proliferation was tested by using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl-tetrazolium bromide) assay on 1st, 4th, 7th days. Results: According to AFM results, there was no statistically significant difference in titanium discs treated with PLGA and with rhTGF-${\beta}2$/PLGA (P>.05). MTT assay test results showed that there was statistically significant difference in mesenchymal stem cell proliferation on test groups compared to control groups at 7th day, and cell viability on discs coated with rhTGF-${\beta}2$ was significantly higher than control groups (P<.05). Conclusion: Titanium surface coated with rhTGF-${\beta}2$/PLGA shows statistically significant higher cell proliferation and the titanium surface coated with the higher concentration of rhTGF-${\beta}2$ presents faster cell growth activity.

• Journal of Dental Rehabilitation and Applied Science
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• v.35 no.3
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• pp.160-169
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• 2019

Purpose: The purpose of this study was to evaluate the antimicrobial effects of a toothbrush with light-emitting diodes (LEDs) on periodontitis-associated dental biofilm attached to a zirconia surface by static and dynamic methods. Materials and Methods: Zirconia disks (12 mm diameter, 2.5 mm thickness) were inserted into a 24-well plate (static method) or inside a Center for Disease Control and Prevention (CDC) biofilm reactor (dynamic method) to form dental biofilms using Streptococcus gordonii and Fusobacterium nucleatum. The disks with biofilm were subdivided into five treatment groups-control, commercial photodynamic therapy (PDT), toothbrush alone (B), brush with LED (BL), and brush with LED+erythrosine (BLE). After treatment, the disks were agitated to detach the bacteria, and the resulting solutions were spread directly on selective agar. The number of viable bacteria and percentage of bacterial reduction were determined from colony counts. Scanning electron microscopy (SEM) was performed to visualize alterations in bacterial morphology. Results: No significant difference in biofilm formation was observed between dynamic and static methods. A significant difference was observed in the number of viable bacteria between the control and all experimental groups (P < 0.05). The percentage of bacterial reduction in the BLE group was significantly higher than in the other treated groups (P < 0.05). SEM revealed damaged bacterial cell walls in the PDT, BL, and BLE groups, but intact cell walls in the control and B groups. Conclusion: The findings suggest that an LED toothbrush with erythrosine is more effective than other treatments in reducing the viability of periodontitis-associated bacteria attached to zirconia in vitro.

• Journal of Korea Entertainment Industry Association
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• v.14 no.6
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• pp.139-150
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• 2020

The data processing of this study focuses on the textom and social media words about three areas: 'Corona 19 and professional baseball', 'Corona 19 and professional baseball', and 'Corona 19 and professional sports' The data was collected and refined in a web environment and then processed in batch, and the Ucinet6 program was used to visualize it. Specifically, the web environment was collected using Naver, Daum, and Google's channels, and was summarized into 30 words through expert meetings among the extracted words and used in the final study. 30 extracted words were visualized through a matrix, and a CONCOR analysis was performed to identify clusters of similarity and commonality of words. As a result of analysis, the clusters related to Corona 19 and Pro Baseball were composed of one central cluster and five peripheral clusters, and it was found that the contents related to the opening of professional baseball according to the corona 19 wave were mainly searched. The cluster related to Corona 19 and unrelated to professional baseball consisted of one central cluster and five peripheral clusters, and it was found that the keyword of the position of professional baseball related to the professional baseball game according to Corona 19 was mainly searched. Corona 19 and the cluster related to professional sports consisted of one central cluster and five peripheral clusters, and it was found that the keywords related to the start of professional sports according to the aftermath of Corona 19 were mainly searched.

• Journal of Korean Medicine Rehabilitation
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• v.18 no.4
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• pp.39-61
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• 2008

Objectives : The present study was performed to investigate whether acupuncture stimulation in the rats affected regeneration properties of the injured sciatic nerve. A differential effect of acupuncture stimulation on the one point near the spinal nerve root controlling sciatic nerve activity and the other point in the peripheral area subordinated by injured nerve was compared. Materials and Methods: Rat sciatic nerves were injured by crush, and the effects on axonal regeneration on injured sciatic nerves were evaluated by acupuncture stimulation at two different regions. In proximal acupuncture stimulation group, acupuncture stimulation was performed on Huatuo Jiaji(EX B2) points located from L5 to S1 vertebral levels to stimulate the nearest spinal nerve root that innervates sciatic nerves. In distal acupuncture stimulation group, acupuncture stimulation was performed on Zusanli(ST 36) and Weizhong(BL 40) points to stimulate at peripheral area dominated by injured sciatic nerves. Acupuncture stimulation was given every other days for 1 or 2 weeks. Sciatic nerve tissues collected from acupuncture stimulation experimental groups, injury control group, and intact animal group were used for protein analysis by Western blotting or Hoechst nuclear staining. To determine axonal regeneration, Dil fluorescence dye was injected into the sciatic nerve 0.5 cm distal to the injury site in individual animal groups and Dil-labeled cells by retrograde tracing were measured in the DRG at lumbar 5 or in the spinal cord. DRG sensory neurons prepared from individual animal groups were used to measure the extent of neurite outgrowth and for immunofluorescence staining with anti-GAP-43 antibody. Results : Animal groups given proximal or distal acupuncture stimulation showed upregulation of GAP-43 and Cdc2 protein levels in the sciatic nerve at 7 days after injury. Cdk2 protein levels were strongly induced by nerve injury, but did not show changes by acupuncture stimulation. Phospho-Erk1/2 protein levels were elevated by acupuncture stimulation above those present in the injury control animals. These increase in regeneration-associated protein levels appeared to be related with increase cell proliferation in the injured sciatic nerves. Hoechst 33258 staining of sciatic nerve tissue to visualize nuclei of individual cells showed increased Schwann cell number in the distal portion of the injured nerve 7 and 14 days after injury and further increases by acupuncture stimulation particularly at the proximal position. Measurement of axonal regeneration by retrograde tracing showed significantly increased Dil-labeled cells in proximal acupuncture stimulation group compared to distal acupuncture stimulation group and injury control group. Finally, an evaluation of axonal regeneration by retrograde tracing showed increased number of Dil labeled cells in the DRG at lumbar 5 or in the ventral horn of the spinal cord at lower thoracic level at 7 days after nerve injury. Conclusions : The present data show that the proximal acupuncture stimulation at Huatuo Jiaji(EX B2) points governing injured sciatic nerves was more effective for axonal regeneration than the distal acupuncture stimulation. Further studies on functional recovery or associated molecular mechanisms should be critical for developing animal models and clinical applications.

• Progress in Medical Physics
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• v.24 no.3
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• pp.198-203
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• 2013

Generally, to evaluate gated radiation therapy, moving phantoms are used to simulate organ motion. Since the target moves in every direction, we need to take into account motion in each direction. This study proposes methods to evaluate gated radiation therapy using gamma index analysis and to visualize adequate gating window sizes according to motion ranges. The moving phantom was fabricated to simulate motion in the craniocaudal direction. This phantom consisted of a moving platform, the I'm MatriXX, and solid water phantoms. A 6 MV photon filed with a field size of $4{\times}4cm^2$ was delivered to the phantom using the gating system, while the phantom moved in the 1-, 2-, 3-, 4-, and 5-cm motion ranges. The gating windows were set at 40~60%, 30~40%, and 0~90%, respectively. The I'm MatriXX acquired the dose distributions for each scenario and the dose distributions were compared with a $4{\times}4cm^2$ static filed. The tolerance of the gamma index was set at 3%/3 mm. The greater the gating window, the lower the pass rate, and the greater the motion range, the lower the pass rate in this study. In case treatment without gated radiation therapy for the target with motion of 2 cm, the pass rate was less than 96%. But it was greater than 99% when gated radiation therapy was used. However gated radiation therapy was used for the target with motion greater than 4 cm, the pass rate could not be greater than 97% when gating window was set as 30~70%. But when the gating window set as 40~60%, the pass rate was greater than 99%.

• Economic and Environmental Geology
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• v.49 no.5
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• pp.381-388
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• 2016

The purpose of this study is to integrate and visualize using mapping techniques based on precise seabed geomorphology, seafloor backscattering images and high-resolution underwater images of the nearshore area around the Dokdo, in the East Sea. We have been obtained the precise topography map using multibeam echosounder system around the nearshore area(~50 m) of the southern part of the Seodo. Side scan sonar survey for analysis seafloor backscattering images was carried out in the same area of topography data. High-resolution underwater images(zone(a), zone(b), zone(c)) were taken in significant habitat scope of the nearshore area of the southern part of the Seodo. Using the results of bathymetry, seafloor backscattering images, high-resolution underwater images, we performed an integrated visualization about the nearshore area of the Dokdo. The integrated visualizing techniques are possible to make the seabed characteristic mapping results of the nearshore area of the Dokdo. The integrated visualization results present more complex and reliable information than separate geological products for seabed environmental mapping study and it is useful to understand the relation between seafloor characteristics and topographic environments of the study area. The integrated visualizing techniques and mapping analysis need to study sustainably and periodically, for effective monitoring of the nearshore ecosystem of the Dokdo.

• The Korean Journal of Nuclear Medicine
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• v.33 no.1
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• pp.65-75
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• 1999

Purpose: The aim of this study is to demonstrate the feasibility of 2-[fluorine-18] fluoro-2-deoxy-D-glucose (F-18-FDG) whole body scan (FDG W/B Scan) using dual-head gamma camera equipped with ultra high energy collimator in patients with various cancers, and compare the results with those of coincidence imaging. Materials and Methods: Phantom studies of planar imaging with ultra high energy and coincidence tomography (FDG CoDe PET) were performed. Fourteen patients with known or suspected malignancy were examined. F-18-FDG whole body scan was performed using dual-head gamma camera with high energy (511 keV) collimators and regional FDG CoDe PET immediately followed it Radiological, clinical follow up and histologic results were correlated with F-18-FDG findings. Results: Planar phantom study showed 13.1 mm spatial resolution at 10 cm with a sensitivity of 2638 cpm/MBq/ml. In coincidence PET, spatial resolution was 7.49 mm and sensitivity was 5351 cpm/MBq/ml. Eight out of 14 patients showed hypermetabolic sites in primary or metastatic tumors in FDG CoDe PET. The lesions showing no hypermetabolic uptake of FDG in both methods were all less than 1 cm except one lesion of 2 cm sized metastatic lymph node. The metastatic lymph nodes of positive FDG uptake were more than 1.5 cm in size or conglomerated lesions of lymph nodes less than 1cm in size. FDG W/B scan showed similar results but had additional false positive and false negative cases. FDG W/B scan could not visualize liver metastasis in one case that showed multiple metastatic sites in FDG CoDe PET. Conclusion: FDG W/B scan with specially designed collimators depicted some cancers and their metastatic sites, although it had a limitation in image quality compared to that of FDG CoDe PET. This study suggests that F-18-FDG positron imaging using dual-head gamma camera is feasible in oncology and helpful if it should be more available by regional distribution of FDG.

• Journal of Veterinary Clinics
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• v.28 no.5
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• pp.497-505
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• 2011

Natural orifice transluminal endoscopic surgery is a newly emerging technique recently, with its many potential advantages in clinical practice. Cholecystectomy by Hybrid NOTES in this work, performed with single working channel endoscope in conjunction with a laparoscopic grasping forceps in dogs, is a "bridge" between laparoscopic procedure and pure NOTES. Three different approaches for cholecystectomy were carried out; transgastric, transcolonic and transvaginal. In all three approaches, abdominal opening was made by a 5 mm trocar, followed by making pneumoperitoneum of 4 mmHg with $CO_2$ insufflator. Transgastric cholecystectomy, single working channel endoscope was advanced to the peritoneal cavity through gastric incision in antral region made by endoscopic needle knife. Endoscope was retroflexed to visualize the gall bladder. Transcolonic access, incision for endoscopic entry was done at right ventral wall of descending colon, 15 cm inside from the anus. Incision in transvaginal access was made at right-ventral region, just caudal to the caudal tubercle. With the simple traction by the laparoscopic grasping forceps, good visualization of surgical field was obtained in all three groups. Cystic duct and artery were ligated with endoclips; for complete gall bladder dissection from liver, L-knife was used. Closure of incision sites were done in transgastric and transcolonic cholecystectomy by endoclips, not in transvaginal approach.

• Economic and Environmental Geology
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• v.54 no.2
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• pp.177-186
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• 2021

For disaster management and mitigation of earthquakes in Korea Peninsula, active fault investigation has been conducted for the past 5 years. In particular, investigation of sediment-covered active faults integrates geomorphological analysis on airborne LiDAR data, surface geological survey, and geophysical exploration, and unearths subsurface active faults by trench survey. However, the fault traces revealed by trench surveys are only available for investigation during a limited time and restored to the previous condition. Thus, the geological data describing the fault trench sites remain as the qualitative data in terms of research articles and reports. To extend the limitations due to temporal nature of geological studies, we utilized a terrestrial LiDAR to produce 3D point clouds for the fault trench sites and restored them in a digital space. The terrestrial LiDAR scanning was conducted at two trench sites located near the Yangsan Fault and acquired amplitude and reflectance from the surveyed area as well as color information by combining photogrammetry with the LiDAR system. The scanned data were merged to form the 3D point clouds having the average geometric error of 0.003 m, which exhibited the sufficient accuracy to restore the details of the surveyed trench sites. However, we found more post-processing on the scanned data would be necessary because the amplitudes and reflectances of the point clouds varied depending on the scan positions and the colors of the trench surfaces were captured differently depending on the light exposures available at the time. Such point clouds are pretty large in size and visualized through a limited set of softwares, which limits data sharing among researchers. As an alternative, we suggested Potree, an open-source web-based platform, to visualize the point clouds of the trench sites. In this study, as a result, we identified that terrestrial LiDAR data can be practical to increase reproducibility of geological field studies and easily accessible by researchers and students in Earth Sciences.

• Journal of Intelligence and Information Systems
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• v.28 no.2
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• pp.147-170
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• 2022

Although the number of patent which is one of the core outputs of technological innovation continues to increase, the number of low-value patents also hugely increased. Therefore, efficient evaluation of patents has become important. Estimation of patent lifespan which represents private value of a patent, has been studied for a long time, but in most cases it relied on a linear model. Even if machine learning methods were used, interpretation or explanation of the relationship between explanatory variables and patent lifespan was insufficient. In this study, patent lifespan (number of renewals) is predicted based on the idea that patent lifespan represents the value of the patent. For the research, 4,033,414 patents applied between 1996 and 2017 and finally granted were collected from USPTO (US Patent and Trademark Office). To predict the patent lifespan, we use variables that can reflect the characteristics of the patent, the patent owner's characteristics, and the inventor's characteristics. We build four different models (Ridge Regression, Random Forest, Feed Forward Neural Network, Gradient Boosting Models) and perform hyperparameter tuning through 5-fold Cross Validation. Then, the performance of the generated models are evaluated, and the relative importance of predictors is also presented. In addition, based on the Gradient Boosting Model which have excellent performance, Accumulated Local Effects Plot is presented to visualize the relationship between predictors and patent lifespan. Finally, we apply Kernal SHAP (SHapley Additive exPlanations) to present the evaluation reason of individual patents, and discuss applicability to the patent evaluation system. This study has academic significance in that it cumulatively contributes to the existing patent life estimation research and supplements the limitations of existing patent life estimation studies based on linearity. It is academically meaningful that this study contributes cumulatively to the existing studies which estimate patent lifespan, and that it supplements the limitations of linear models. Also, it is practically meaningful to suggest a method for deriving the evaluation basis for individual patent value and examine the applicability to patent evaluation systems.