• 한국초전도ㆍ저온공학회논문지
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• 제18권1호
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• pp.41-45
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• 2016

The technology of supplying the electric power by wireless power transfer (WPT) is expected for the next generation power feeding system since it can supply the power to portable devices without any connectors through large air gap. As such a technology based on strongly coupled electromagnetic resonators is possible to deliver the large power and recharge them seamlessly; it has been considered as a noble option to wireless power charging system in the various power applications. Recently, various HTS wires have now been manufactured for demonstrations of transmission cables, motors, MAGLEV, and other electrical power components. However, since the HTS magnets have a lower index n value intrinsically, they are required to be charged from external power system through leads or internal power system. The portable area is limited as well as the cryogen system is bulkier. Thus, we proposed a novel design of wireless power charging system for superconducting HTS magnet (WPC4SM) based on resonance coupling method. As the novel system makes possible a wireless power charging using copper resonance coupled coils, it enables to portable charging conveniently in the superconducting applications. This paper presented the conceptual design and operating characteristics of WPC4SM using different shapes' copper resonance coil. The proposed system consists of four components; RF generator of 370 kHz, copper resonance coupling coils, impedance matching (IM) subsystem and HTS magnet including rectifier system.

• Journal of Korean Neurosurgical Society
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• 제63권6호
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• pp.767-776
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• 2020

Objective : The aim of this study is to evaluate the feasibility of posterior cervical foraminotomy (PCF) for adjacent segmental disease (ASD) after anterior cervical fusion (ACF). As ACF is accepted as the standard treatment for cervical spondylosis, many studies have been conducted to evaluate the efficacy of various surgical techniques to overcome symptomatic ASD after the previous surgery. Herein, PCF was performed for the treatment of symptomatic ASD and the feasibility of the surgery was evaluated. Methods : Forty nine patients who underwent PCF due to symptomatic ASD from August 2008 to November 2017 were identified. For demographic and perioperative data, the sex, age, types of previous surgery, ASD levels, operation times, and bleeding amount were recorded. The clinical outcome was assessed using the visual analogue scale for the neck and arm, the modified Odom's criteria as well as neck disability index. Radiologic evaluations were performed by measuring disc softness, disc height, the cervical 2-7 sagittal vertical axis, cervical cobb angle, and facet violation. Results : Thirty-seven patients were enrolled in this study. The patients were divided into two groups based on the location of the pathology; paracentral (group P) or foramina (group F). Both groups showed significant clinical improvement (p<0.05). The proportion of calcified disc and facet violations was significantly larger in group F (p<0.05). The minimal disc height decrease with mild improvement on sagittal alignment and cervical lordosis was radiologically measured without statistical significance in both groups (p>0.05). Conclusion : PCF showed satisfactory clinical and radiologic outcomes for both paracentral and foraminal pathologies of ASD after ACF. Complications related to anterior revision were also avoided. PCF can be considered a feasible and safe surgical option for ASD after ACF.

• Journal of Korean Neurosurgical Society
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• 제56권4호
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• pp.310-314
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• 2014

Objective : To analyze the clinical courses and outcomes after anterior lumbar interbody fusion (ALIF) for the treatment of postoperative spondylodiscitis. Methods : A total of 13 consecutive patients with postoperative spondylodiscitis treated with ALIF at our institute from January, 1994 to August, 2013 were included (92.3% male, mean age 54.5 years old). The outcome data including inflammatory markers (leukocyte count, C-reactive protein, erythrocyte sedimentation rate), the Oswestry Disability Index (ODI), the modified Visual Analogue Scale (VAS), and bony fusion rate using spine X-ray were obtained before and 6 months after ALIF. Results : All of the cases were effectively treated with combination of systemic antibiotics and ALIF with normalization of the inflammatory markers. The mean VAS for back and leg pain before ALIF was $6.8{\pm}1.1$, which improved to $3.2{\pm}2.2$ at 6 months after ALIF. The mean ODI score before ALIF was $70.0{\pm}14.8$, which improved to $34.2{\pm}27.0$ at 6 months after ALIF. Successful bony fusion rate was 84.6% (11/13) and the remaining two patients were also asymptomatic. Conclusion : Our results suggest that ALIF is an effective treatment option for postoperative spondylodiscitis.

• 한국발생생물학회지:발생과생식
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• 제22권2호
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• pp.133-142
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• 2018

Patients with type II diabetes mellitus are more susceptible to colorectal cancer (CRC) incidence than non-diabetics. The anti-diabetic drug metformin is most commonly prescribed for the treatment of this disease and has recently shown antitumor effect in preclinical studies. The aberrant mutational activation in the components of RAS/RAF/MEK/ERK and PI3K/AKT/mTOR signaling pathway is very frequently observed in CRC. We previously reported that metformin inhibits the phosphorylation of ERK and BEZ235, a dual inhibitor of PI3K and mTOR, has anti-tumor activity against HCT15 CRC cells harboring mutations of KRAS and PIK3CA. Therefore, we hypothesized that simultaneous inhibition of two pathways by combining metformin with BEZ235 could be more effective in the suppression of proliferation than single agent treatment in HCT15 CRC cells. Here, we investigated the combinatory effect of metformin and BEZ235 on the cell survival in HCT15 CRC cells. Our study shows that both of the two signaling pathways can be blocked by this combinational strategy: metformin suppressed both pathways by inhibiting the phosphorylation of ERK, 4E-BP1 and S6, and BEZ235 suppressed PI3K/AKT/mTOR pathway by reducing the phosphorylation of 4E-BP1 and S6. This combination treatment synergistically reduced cell viability. The combination index (CI) values ranged from 0.44 to 0.88, indicating synergism for the combination. These results offer a preclinical rationale for the potential therapeutic option for the treatment of CRC.

• 대한토목학회논문집
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• 제37권5호
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• pp.879-890
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• 2017

기존 미국의 포장 설계법(AASHTO)과 대표적인 도로포장 유지보수 의사결정시스템인 HDM-4는 국내 실정 또는 환경에 적합하지 않아 현실적인 도로설계, 시공 및 유지관리 차원에서 국내에 적합하지 않다. 포장 수명 연장에 따른 환경비용에서도 차이가 발생할 것으로 판단되는 바, 본 연구의 주요 목표는 대한민국의 환경조건과 차종별 특성을 반영한 한국형 도로포장 설계법(KPRP) 설계 소프트웨어의 도로 공용성 해석 모델을 기반으로 활용하여 운영 및 유지보수단계에서 대표적인 세 가지 유지보수전략별 LCCC 계산을 통해 최적 대안을 선정하는 것이다. 본 연구 결과 40년 동안의 누적 탄소배출량은 대안 2의 절삭 및 덧씌우기가 누적 탄소배출량과 LCCC의 현재가치비용이 제일 적은 것으로 분석되었다. 본 연구를 통해 다양한 도로관리 유지보수 공사별 $CO_2$배출 원단위 구축이 가능하며 향후 탄소요금의 증가에 따른 도로시설별 다양한 유지관리 전략 마련에 대한 기초연구를 수행하였다는 점에 의의가 있다.

• Journal of Oral Medicine and Pain
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• 제41권1호
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• pp.7-15
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• 2016

Purpose: Mandibular advancement device (MAD) is widely recognized as an important treatment option for obstructive sleep apnea (OSA) and is readily accepted than any other treatment options owing to its simplicity and ambulatory nature. At this time, there are a multitude of MAD designs and their efficacies may be influenced by adjustment and retention mechanism. The MAD with the anterior connector (anteriorly adjustable mandibular advancement device, AAMAD) was newly developed in the Department of Oral Medicine, Dankook University Dental Hospital (Cheonan, Korea) and was prescribed for the OSA patients including snoring patients. Thus, this study was aimed to objectively investigate the effectiveness of the AAMAD on the OSA patients using the self-applied portable device (ApneaLink), and evaluate the treatment outcomes among patients with various severity of OSA level. Methods: Results of the treatment of fourteen patients (13 male, 1 female) with the AAMAD were retrospectively analyzed. Each patient underwent home sleep test before treatment and were divided into two groups, i.e., those with mild (apnea-hypopnea index [AHI] ${\geq}5$ and <15) to moderate OSA (AHI ${\geq}15$ and <30) and severe OSA (AHI ${\geq}30$). After treatment, home sleep test was conducted again and treatment outcomes were compared between mild to moderate and severe OSA patients. Results: Of all patients, 78.6% showed more than 50% AHI reduction. We found a significant reduction (85.3%) of AHI in the severe OSA patients. Patients with mild to moderate OSA showed the reduced AHI (56.1%). Conclusions: We concluded that AAMAD is an effective oral appliance for the majority of OSA patients.

• Journal of Periodontal and Implant Science
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• 제38권3호
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• pp.521-528
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• 2008

Purpose: Tunneling is a periodontal surgical procedure that creates access for patient cleansing and maintenance within the furcal area of a molar tooth with severe furcation involvement. Up to date, there are few studies about a long term clinical and radiographic stability of tunneling. The purpose of this retrospective study is to evaluate the long term prognosis after tunnel preparation of molars with through and through furcation. Material and Methods: 25 teeth of 23 patients aged 36 to 70 (mean age 51.7) were treated surgically with tunnel preparation. These cases were followed for 2 to 13 years (mean 6.5years) after surgery. Patients were recalled for an evaluation which was based on a questionnaire, a clinical examination, and radiographic analysis. Clinical assessment included plaque index, caries registration, probing pocket depth, bleeding on probing, tooth mobility. Baseline and over 2-year follow-up radiographs were collected and evaluated for this study. Result: 3 teeth(12%) had been extracted and 1 tooth(4%) hemisected. Root caries was detected in 3 teeth(12%). Thus 72% of the teeth were still caries tree and in function. Clinical parameters including PI, PD, BOP, mobility showed somewhat favourable results. Radiographic furcal bone loss showed no statistically significant difference compared to interproximal crestal bone loss ($3.59{\pm}1.69%$ vs $3.42{\pm}2.95%$) when root length was used as reference. There was no correlation between root trunk length and furcal bone loss. Conclusion: Over 2 years after tunneling procedure, teeth showed a clinically and radiographically stable condition, despite of slight root caries and alveolar bone loss within clinically acceptable range. The tunnel procedure may be considered as a viable periodontal treatment option for molar teeth with severe furcation involvement in individuals following a regular maintenance program.

• The Korean Journal of Pain
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• 제33권3호
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• pp.226-233
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• 2020

Background: We aimed to compare interlaminar epidural steroid injections (ILESI) and bilateral transforaminal epidural steroid injections (TFESI) on pain intensity, functional status, depression, walking distance, and the neuropathic component in patients with lumbar central spinal stenosis (LCSS). Methods: The patients were divided into either the ILESI or the bilateral TFESI groups. Prime outcome measures include the numerical rating scale (NRS), Oswestry disability index (ODI), Beck depression inventory (BDI), and pain-free walking distance. The douleur neuropathique en 4 questions score was used as a secondary outcome measure. Results: A total of 72 patients were finally included. NRS, ODI, and BDI scores showed a significant decline in both groups in all follow-ups. Third-month NRS scores were significantly lower in the ILESI group (P = 0.047). The percentages of decrease in the ODI and BDI scores between the baseline and the third week and third month were significantly higher in the ILESI group (P = 0.017, P = 0.001 and P = 0.048, P = 0.030, respectively). Pain-free walking distance percentages from the baseline to the third week and third month were significantly higher in the ILESI group (P = 0.036, P < 0.001). The proportion of patients with neuropathic pain in the bilateral TFESI group significantly decreased in the third week compared to the baseline (P = 0.020). Conclusions: Both ILESI and TFESI are reliable treatment options for LCSS. ILESI might be preferred because of easier application and more effectiveness. However, TFESI might be a better option in patients with more prominent neuropathic pain.

• 대한한방내과학회지
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• 제37권2호
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• pp.361-367
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• 2016

Objective: This clinical study reports on the effect of traditional Korean medicine on a patient with generalized anxiety disorder.Method: A patient who suffered from generalized anxiety disorder was treated with herbal medicine (Guibiondamtang-gami), acupuncture, moxibustion, and pharmacopuncture. We assessed the changes of anxiety-related symptoms with the state-trait anxiety inventory (STAI) score, the Beck anxiety inventory (BAI) score, a heart rate variability (HRV) test, and a second derivative of photoplethymogram waveform (SDPTG) test.Results: After taking Guibiondamtang-gami for 22 days, the patient’s STAI score, BAI score, and LF/HF (low-frequency/high-frequency heart rate variability) ratio decreased, while the differential pulse wave index and stress power in the SDPTG test increased.Conclusion: This clinical case study has demonstrated that traditional Korean medicine may be an effective option for treating generalized anxiety disorder.

• Korean Journal of Acupuncture
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• 제35권2호
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• pp.82-90
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• 2018

Objectives : The purpose of this study is to investigate the effect of acupoint and meridian muscle massage given by automatic massage chair. Methods : We recruited 30 patients with back pain who met inclusion criteria. Two weeks were given as a waiting period, and the massage intervention was applied 12 times for 4 weeks. The programmed automatic massage chair was used to provide effective stimulus on acupoints and meridians for 20 minutes. We used Visual analog scale(VAS) and Korean Oswestry Disability Index(KODI) to quantify pain and function. We also recorded patients' all of vital signs and abnormal reactions during the trial to asses to assess safety. Results : Two participants dropped out due to personal reasons and 28 participants completed the clinical trial. We found that the degree of back pain (VAS, KODI) decreased significantly after the trial. As a result, VAS score decreased from $6.44{\pm}0.85$(Visit 2) to $4.59{\pm}1.52$ (Visit 14)(p<0.001), and KODI score was also reduced from $14.79{\pm}5.13$(Visit 14) to $9.04{\pm}4.52$ (Visit 2) (p<0.001). Also, we did not find any adverse effects in this study. Conclusions : We found that the acupoint and meridian muscle massage can effectively decrease back pain. This proves that the massage program designed by Korean medicine can be a good option to patients with back pain. However, further study with controlled design is still needed to verify its effectiveness.