• Journal of Periodontal and Implant Science
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• 제49권1호
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• pp.47-57
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• 2019

Purpose: This study was designed to observe the resorption pattern of biphasic calcium phosphate (BCP) used for maxillary sinus augmentation over a 3- to 6-year healing period, and to investigate factors affecting the resorption of BCP. Methods: A total of 47 implants placed in 27 sinuses of 22 patients were investigated. All patients had residual bone height less than 5 mm at baseline. The modified Caldwell-Luc approach was used to elevate the maxillary sinus membrane, and the sinus cavity was filled with BCP (70% hydroxyapatite and 30% ${\beta}$-tricalcium phosphate). Implant placement was done simultaneously or in a staged manner. Serial radiographic analysis was performed up to 6 years postoperatively. Results: During the follow-up period, no implant loss was reported. The mean reduced height of the augmented sinus (RHO) was $0.27{\pm}1.08mm$ at 36 months, and $0.89{\pm}1.39mm$ at 72 months postoperatively. Large amounts of graft material (P=0.021) and a long healing period (P=0.035) significantly influenced the amount of RHO. In particular, there was a significant relationship between a healing period longer than 40 months and RHO. Conclusions: BCP can achieve proper dimensional stability with minimal reduction of the graft height in a 3- to 6-year healing period after maxillary sinus augmentation. The healing period and the amount of graft material influenced the resorption of BCP.

• 한국전문물리치료학회지
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• 제26권2호
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• pp.1-7
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• 2019

Background: In previous studies, changes in postural alignment were found when the slope was changed during walking. Downhill walking straightens the trunk by shifting the line of gravity backward. Objects: This study investigated the effect of the downhill treadmill walking exercise (DTWE) on thoracic angle and thoracic erector spinae (TES) activation in subjects with thoracic kyphosis. Methods: A total of 20 subjects with thoracic kyphosis were recruited for this study. All the subjects performed the DTWE for 30 minutes. A surface EMG and 3D motion capture system were used to measure TES activation and thoracic angle before and after the DTWE. Paired t-tests were used to confirm the effect of the DTWE (p<.05). Results: Both the thoracic angle and TES activation had significantly increased after the DTWE compared to the baseline (p<.05). An increase in the thoracic angle indicates a decrease in kyphosis. Conclusion: The DTWE is effective for thoracic kyphosis patients as it decreases their kyphotic posture and increases the TES activation. Future longitudinal studies are required to investigate the long-term effects of the DTWE.

• 한국측량학회지
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• 제38권6호
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• pp.717-723
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• 2020

VLBI, SLR, DORIS, GNSS와 같은 우주측지기술 사이의 3차원 벡터를 결정하는 작업은 ITRF에 중요한 요소이다. 따라서 각각의 우주측지기술에 해당되는 IVP를 정확하게 계산할 필요가 있다. 본 연구에서는 기존 모델에 비해 업데이트된 수학모델을 사용하여 세종시에 위치한 VLBI의 IVP 위치를 계산함으로써 계산의 효율과 신뢰성을 높였다. 관측값으로는 안테나에 부착된 반사타겟의 좌표가 사용되었으며 이때 관측오차크기는 1.5 mm로 설정하였다. 조정계산을 통해 VLBI IVP 좌표와 정확도를 계산했으며 기존 연구에서 제시한 값과 비교했을 때 성공적으로 계산이 된 것으로 판단된다. 하지만 실제 관측오차가 고려된 VLBI IVP를 계산하기 위해서는 향후 VLBI IVP 계산을 위한 추가적인 지상측량이 필요하다.

• Journal of Periodontal and Implant Science
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• 제51권3호
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• pp.179-188
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• 2021

Purpose: Due to the difficulty of the hygienic care and sanitary management of abutment teeth and subpontic areas associated with fixed dental prostheses (FDPs), intrabony defects occur and accelerate due to the accumulation of plaque and calculus. This study aimed to evaluate the efficacy of regenerative periodontal surgery for intrabony defects associated with FDPs. Methods: The study inclusion criteria were met by 60 patients who underwent regenerative treatment between 2016 and 2018, involving a total of 82 intrabony defects associated with FDPs. Periodontal osseous lesions were classified as 1-, 2-, and 3-wall intrabony defects and were treated with an enamel matrix derivative in combination with bone graft material. The changes in clinical (pocket probing depth [PPD] and clinical attachment level [CAL]) and radiographic (defect depth and width) outcomes were measured at baseline and at 6, 12, and 24 months. Results: Six months after regenerative treatment, a significant reduction was observed in the PPD of 1-wall (P<0.001), 2-wall (P<0.001), and 3-wall (P<0.001) defects, as well as a significant reduction in the CAL of 2-wall (P<0.001) and 3-wall (P<0.001) intrabony defects. However, there was a significant increase in the CAL of 1-wall intrabony defects (P=0.003). Radiographically, a significant reduction in the depth of the 3-wall (P<0.001) defects and a significant reduction in the width of 2-wall (P=0.008) and 3-wall (P<0.001) defects were observed. The depth decreased in 1-wall defects; however, this change was not statistically significant (P=0.066). Conclusions: Within the limitations of the current study, regenerative treatment of 2- and 3-wall intrabony defects associated with FDPs improved clinical and radiological outcomes. Additional prospective studies are necessary to confirm our findings and to assess long-term outcomes.

• 보건행정학회지
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• 제30권4호
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• pp.467-478
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• 2020

Background: The purpose of this study is to explain the factors influencing the incurrence of catastrophic health expenditure of national health insurance households using panel data observed over a long period. Methods: The study targeted 3,652 households who had no censoring during the 11-year survey period (2007-2017) and householders whose insurance type was consistently maintained as national health insurance. Generalized estimating equations were adopted to identify factors affecting the occurrence of catastrophic health expenditure at 20%, 30%, and 40% threshold levels. A subgroup analysis was conducted by categorizing groups depending on the existence of the elderly in the household. Results: For the last 11 years, the incidence of catastrophic health expenditure in the households without the elderly decreased slightly at all threshold levels, but the households with the elderly seemed to be increased. At baseline, household type showed a statistically significant relationship with all other variables. The results of generalized estimating equations analyses show that household income was not significant at all threshold levels in the households without elderly. On the other hand, in the households with the elderly, the 2nd (odds ratio [OR], 1.33-2.05) and 3rd quintile groups (OR, 1.25-2.55) were more likely to have catastrophic health expenditure compared to the 1st quintile of household income group. Conclusion: As the amount of health expenditures relative to the ability to pay is increasing in households with the elderly, the application of an intervention followed by consistent monitoring is needed. This study found that there were differences in influencing factors according to the presence of the elderly in the households. In particular, in households with the elderly, interesting results have been drawn regarding the occurrence of catastrophic health expenditure in the near-poor, so additional research is required.

• Tuberculosis and Respiratory Diseases
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• 제85권4호
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• pp.332-340
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• 2022

Background: Cardiac dysfunction patients have long been considered at high risk of reintubation. However, it is based on past studies in which only conventional oxygen therapy was applied after extubation. We investigated association between cardiac dysfunction and reintubation rate in situation where high-flow nasal cannula (HFNC) was widely used during post-extubation period. Methods: We conducted a retrospective observational cohort study of patients treated with HFNC after planned extubation in medical intensive care unit of single tertiary center. Patients were divided into normal function group (ejection fraction [EF] ≥45%) and cardiac dysfunction group (EF <45%). The primary outcome was reintubation rate within 72 hours following extubation. Results: Of 270 patients, 35 (13%) had cardiac dysfunction. Baseline characteristics were similar in both groups. There were no differences in the changes in vital signs between the two groups during the first 12 hours after extubation except diastolic blood pressure. The reintubation rates were 20% and 17% for cardiac dysfunction group and normal function group, respectively (p=0.637). In a multivariate Cox regression analysis, cardiac dysfunction was not associated with an increased risk of reintubation within 72 hours following extubation (hazard ratio, 1.56; p=0.292). Conclusion: Cardiac dysfunction was not associated with increased reintubation rate within 72 hours when HFNC is immediately applied after planned extubation.

• Journal of Positioning, Navigation, and Timing
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• 제10권4호
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• pp.379-385
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• 2021

In order to synchronize a remote system time to the reference time like Coordinated Universal Time (UTC), it is required to compare the time difference between the two clocks. GNSS Precise Point Positioning (PPP) is one of the most general geodetic positioning methods and can be used for time and frequency transfer applications which require more precise time comparison performance than GNSS code. However, the PPP technique has a main drawback of day-boundary discontinuity which comes from the PPP model that the code measurements are applied to resolve the floating carrier-phase ambiguities. The Integer PPP (IPPP) technique is one of the methods which has been studied to compensate the day-boundary discontinuities exited in the conventional PPP. In this paper, we investigate the time and frequency capabilities of PPP and IPPP by using the measurement data obtained from two time transfer receivers which are closely located and using common reference 1 Pulse Per Second (PPS) and RF signals. From the experiment, it is investigated that the IPPP method can effectively compensate the day-boundary discontinuities without producing frequency offset. However, the PPP method can generating frequency offset which can severely degrade the time comparison performance with long-term period data.

• 대한한의학방제학회지
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• 제30권3호
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• pp.123-135
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• 2022

Oryeongsan (ORS), a formula composed of five herbal medicines, has long been used to treat impairments of the regulation of body fluid homeostasis. The purpose of this study was to determine the antihypertensive and renal protective effects of ORS in rats with hypertension. Spontaneously hypertensive rats (SHR) were divided into two groups with similar mean baseline systolic blood pressure (SBP). Then, 1 mL/kg of vehicle (distilled water) or 1.5, 3 g/kg of ORS extract were administered orally once a day for 4 weeks. SBP and diastolic blood pressure (DBP) were measured at weeks 1, 2, 3 and 4. At the end of the experiment, blood was collected, and heart were removed for histology. By the 2 weeks after initiation of treatment, the ORS treated group had significantly lower SBP than SHR rats. The ORS treatment significantly improved blood pressure and echocardiogram parameters compared to hypertensive rats. Additionally, the left ventricular (LV) remodeling and LV dysfunction were significantly improved in ORS treated group hypertensive rats. Furthermore, an increase in fibrotic area has been observed in SHR rats compared with Wistar-Kyoto rats (WKY). Furthermore, administration of ORS significantly attenuated cardiac fibrosis in hypertensive rats. Therefore, these findings suggest that ORS has a protective effect on heart failure by alleviating hypertensive heart disease and cardiovascular dysfunction in SHR.

• Journal of Chest Surgery
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• 제56권1호
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• pp.35-41
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• 2023

Background: We analyzed our experience with descending necrotizing mediastinitis (DNM) treatment and investigated the efficacy of video-assisted thoracoscopic surgery (VATS) for mediastinal drainage. Methods: This retrospective analysis included patients who underwent surgical drainage for DNM at our hospital from 2005 to 2020. We analyzed patients' baseline characteristics, surgical data, and perioperative outcomes and compared them according to the mediastinal drainage approach among patients with type II DNM. Results: Twenty-five patients (male-to-female ratio, 18:7) with a mean age of 54.0±12.9 years were enrolled in this study. The most common infection sources were pharyngeal infections (60%). Most patients had significantly increased white blood cell counts, elevated C-reactive protein levels, and decreased albumin levels on admission. The most common DNM type was type IIB (n=16, 64%), while 5 and 4 patients had types I and IIA, respectively. For mediastinal drainage, the transcervical approach was used in 15 patients and the transthoracic approach (VATS) in 10 patients. The mean length of hospital stay was 26.5±23.8 days, and the postoperative morbidity and in-hospital mortality rates were 24% and 12%, respectively. No statistically significant differences were found among patients with type II DNM between the transcervical and VATS groups. However, the VATS group showed shorter mean antibiotic therapy duration, drainage duration, and hospital stay length than the transcervical group. Conclusion: DNM manifested as severe infection requiring long-term inpatient treatment, with a mortality rate of 12%. Thus, active treatment with a multidisciplinary approach is crucial, and mediastinal drainage using VATS is considered relatively safe and effective.