• Journal of Yeungnam Medical Science
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• v.41 no.1
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• pp.39-44
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• 2024

Background: Medication-related osteonecrosis of the jaw (MRONJ) is a significant concern, particularly among patients taking bisphosphonates (BPs), denosumab, and selective estrogen receptor modulators (SERMs) for osteoporosis. Despite the known risks, large-scale cohort studies examining the incidence and severity of MRONJ are lacking. We aimed to ascertain the incidence and risk of MRONJ among these patients, whom we stratified by age groups, medication types, and duration of use. Methods: We utilized data from the National Health Insurance Service's sample cohort database, focusing on patients aged 40 years and above diagnosed with osteoporosis. The patients were divided into three groups: those prescribed BPs only, those prescribed SERMs only, and those prescribed both. Results: The overall incidence rate of MRONJ was 0.17%. A significantly higher incidence rate was observed among those taking osteoporosis medications, particularly among females with a relative risk of 4.99 (95% confidence interval, 3.21-7.74). The SERM group also had an incidence rate comparable to that of the BP group. Severity was assessed based on the invasiveness of the treatment methods, with 71.3% undergoing invasive treatment in the medication group. Conclusion: This study provides valuable insights into the incidence and severity of MRONJ among a large cohort of patients with osteoporosis. It underscores the need for comprehensive guidance on MRONJ risks across different medication groups and sets the stage for future research focusing on specific populations and treatment outcomes.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.4 s.181
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• pp.183-190
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• 2006

Digital 3D Real Object Duplication System (RODS) consists of 3D Scanner and Solid Freeform Fabrication System (SFFS). It is a device to make three-dimensional objects directly from the drawing or the scanning data. In this research, we developed an office type SFFS based on Three Dimensional Printing Process and an industrial SFFS using Dual Laser. An office type SFFS applied sliding mode control with sliding perturbation observer (SMCSPO) algorithm for control of this system. And we measured process variables about droplet diameter measurement and powder bed formation etc. through experiments. In case of industrial type SFFS, in order to develop more elaborate and speedy system for large objects than existing SLS process, this study applies a new Selective Dual-Laser Sintering (SDLS) process and 3-axis Dynamic Focusing Scanner for scanning large area instead of the existing f lens. In this process, the temperature has a great influence on sintering of the polymer. Also the laser parameters are considered like that laser beam power, scan speed, and scan spacing. Now, this study is in progress to evaluate the effect of experimental parameters on the sintering process.

• Journal of Korea Game Society
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• v.14 no.6
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• pp.99-108
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• 2014

This paper shows an analysis of the effectiveness of internet games shutdown policy being conducted in Korea and focusing on a verification of the effects of the selective games shutdown and the compulsory games shutdown running for the prevention of adolescents' addiction by korea government (Ministry of Culture, Sports and Tourism, Ministry of Gender Equality and Family). According to the results, It is difficult to clearly prove the causal relations between internet games and addiction. Also the internet games shutdown policy is not only the most effective means for preventing internet games addiction. On the basis of it, this paper proposes effective policy measures to prevent the internet game addiction of adolescents.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.197-198
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• 2006

In the solid freeform fabrication (SFF) system using selective laser sintering (SLS), polyamide-12 powder is currently recognized as general material. In this study, some kinds of polyamide-6 powders with different shape and particlesize were fabricated to investigate the formability, the microstructure and mechanical properties. Also, to develop a more elaborate and rapid system, this study employs a new SLS device with a 3-axis dynamic focusing scanner system instead of the existing fe lens used in commercial SLS. Polyamide-6 powders having the average size of 100 m were treated thermally in order to keep the spherical symmetry in shape. These polyamide-6 powders were mixed with polyamide-12 powders having the average size of 50 m to give the bimodal distribution of size. These mixed powders showed the better fabrication in the selective laser sintering process because the smaller particles of polyamide-11 played an important role in the compact packing of powders by filling the void space between the large particles of polyamide-6. Also, Experiments have performed to evaluate the effect of a scanning path and sintering parameters by fabricating the various 3D objects.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.4
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• pp.45-53
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• 2003

A new smart antenna receiver which incorporates the spatial fourier Transform and the maximal ratio combining(MRC) is proposed. By adapting the spatial fourier transform, the proposed method could separate the received signal into several spatial frequency components which correspond to the arrival angles of signal components, which means the beam focusing. By using the MRC, the proposed method could achieve the maximum signal to noise ratio for the signal of interest. The proposed algorithm is integrated to the CDMA reverse link receiver and simulations are performed to confirm the performance. As a result, the beam focusing effect is confirmed and the performance gain with the proposed algorithm is comparable to ordinary smart antenna receivers. The simulations are performed over the additive white gaussian noise (AWGN) environments and the results are obtained for the beam focusing capability according to the angle of arrival of a signal and the bit error performance improvement according to the number of combining branches in the MRC.

• Journal of Korea Water Resources Association
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• v.55 no.12
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• pp.1021-1030
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• 2022

Currently, South Korea implements water resources management policies focusing on integrated water quantity, quality and hydro-ecology management. In particular, rehabilitation of natural rivers has become a major issue. As for reservoir operation during non-flood season, efforts have been made continuously to apply the Deficit Supply Method that can maximize water supply to address droughts and increase in water demand. When Deficit Supply Method is applied, the water supply capacity of reservoir can be maximized. However, downstream water flow would remain constant. In consideration that a natural stream, a long-time-created hydro-ecology, can be significantly influenced by flow variability, the Deficit Supply Method-based reservoir operation can generate effective water supply. Still, it may trigger adverse effects from the aspects of natural rehabilitation and hydro-ecology recovery. The main objective of this study is to analyze impacts on downstream flow duration through reservoir simulation by comparing the Firm Supply Method, the Deficit Supply Method and the Selective Deficit Supply Method, and examining each method's effects on reservoir operation. This study found that the Firm Supply Method could maintain water flow variability, but could not maximize water supply capacity. When the Deficit Supply Method was applied, water supply capacity could be increased while remaining vulnerable regarding water flow variability, as a difference between average flow and low flow was negligible at downstream. In comparison, the Selective Deficit Supply Method was found to sustain time-based reliability at 95% or higher, whereas downstream flow duration could be maintained at a level similar to the level generated by the Firm Supply Method.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.4
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• pp.1589-1593
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• 2012

Objective: To investigate liver fibrosis, TGF-${\beta}1$ levels and curative effects on hepatocellular carcinoma (HCC) with small and conventional dose perfusion chemotherapy by transcatheter arterial chemo embolization (TACE). Methods: Thirty-six hepatocellular carcinoma patients not indicated for surgical resection underwent super-selective transcatheter arterial chemoembolization, divided into small dose (n=15) and conventional dose (n=21) chemotherapy groups. Results: With conventional doses, four indices of liver fibrosis focusing on hyaluronate acide (HA), human procollagen type-III (hPC-III), collagen type-Ⅳ (Ⅳ-C) and transforming growth factor-${\beta}l$ (TGF-${\beta}1$) were obviously increased postoperative compared with preoperative (P<0.01); in contrast, with small doses there were no significant differences except for TGF-${\beta}1$. Five year survival demonstrated no significant differences between the two groups (P>0.05). Conclusion: To hepatocellular carcinoma patients treated by TACE, reducing doses of chemotherapy drugs can reduce progress of liver fibrosis, without impacting on five year survival.

• BMB Reports
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• v.49 no.9
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• pp.474-487
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• 2016

Itch is one of the most distressing sensations that substantially impair quality of life. It is a cardinal symptom of many skin diseases and is also caused by a variety of systemic disorders. Unfortunately, currently available itch medications are ineffective in many chronic itch conditions, and they often cause undesirable side effects. To develop novel therapeutic strategies, it is essential to identify primary afferent neurons that selectively respond to itch mediators as well as the central nervous system components that process the sensation of itch and initiate behavioral responses. This review summarizes recent progress in the study of itch, focusing on itch-selective receptors, signaling molecules, neuronal pathways from the primary sensory neurons to the brain, and potential decoding mechanisms based on which itch is distinguished from pain.

• Journal of Information Science Theory and Practice
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• v.8 no.2
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• pp.32-44
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• 2020

This study attempts to draw the implications of student satisfaction with fieldwork courses in the library and information science (LIS) program in South Korea by determining the level of satisfaction experienced by students with practicums at a library and information service agency. LIS students with fieldwork experience were surveyed to assess their satisfaction and the factors affecting their satisfaction. Results from a multiple regression analysis revealed that from among factors of practicum settings, major-related attributes, and general attributes of respondents, "satisfaction with majors" and "interpersonal relationships" had a significant effect on satisfaction with practicums. Examining the six components of satisfaction with the course revealed that "practicum program" and "practicum setting" had a significant relationship with overall satisfaction. A selective intervention program to improve satisfaction with the course needs to be developed based on factors influencing overall satisfaction, focusing on "interpersonal relationship" and "satisfaction with majors.

• Archives of Pharmacal Research
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• v.4 no.2
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• pp.85-90
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• 1981

A quantitative GC-MS spectrometric assay was used for the determination of residual N, N-dimethylaniline as a contaminant in commercial penicillin derivatives from various sources. The assay utilizes selective ion focusing to monitor in a GC effluent the molecular ions of DMA generated by electron impact ionization. This method includes dissolution of the sample in alkaline solution, extraction of organic base with cyclohexane and injection into GC-MS with a 3% OV-17 column. Levels of 50 ppb of DMA were easily measured with a coeffecient of varation less than 5 % and recoveries from spiked samples exceeded 97 %. The results of the determinations of DMA in various commercial penicillins were relatively free of this contaminant.