• 대한치과보철학회지
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• 제43권2호
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• pp.248-257
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• 2005

Statement of problem. Cortical bone plays an important role in the primary implant stability, which is essential to immediate/early loading. However, immediate load-bearing capacity and primary implant stability according to the change of the cortical bone thickness have not been reported. Purpose. The objectives of this study were (1) to measure the immediate load-bearing capacity of implant and primary implant stability according to the change of cortical bone thickness, and (2) to evaluate the correlation between them. Material and methods.48, screw-shaped implants (3.75 mm$\times$7 mm) were placed into bovine rib bone blocks with different upper cortical bone thickness (0-2.5 mm) and resonance frequency (RF) values were measured subsequently. After fastening of healing abutment. implants were subjected to a compressive load until tolerated micromotion threshold known for the osseointegration and load values at threshold were recorded. Thereafter, RF measurement after loading, CT taking and image analysis were performed serially to evaluate the cortical bone quality and quantity. Immediate load-bearing capacity and RF values were analyzed statistically with ANOVA and post-hoc method at 95% confidence level (P<0.05). Regression analysis and correlation test were also performed. Results. Existence and increase of cortical bone thickness increased the immediate load-bearing capacity and RF value (P<0.05) With the result of regression analysis, all parameter's of cortical bone thickness to immediate load-bearing capacity and resonance frequency showed significant positive values (P<0.0001). A significant high correlation was observed between the cortical bone thickness and immediate load-beating capacity (r=0.706, P<0.0001), between the cortical bone thickness and resonance frequency (r=0.753, P<0.0001) and between the immediate load-bearing capacity and resonance frequency (r=0.755, P<0.0001). Conclusion. In summary, cortical bone thickness change affected the immediate load-baring capacity and the RF value. Although RF analysis (RFA) is based on the measurement of implant/bone interfacial stiffness, when the implant is inserted stably, RFA is also considered to reflect implant/bone interfacial strength of immediately after placement from high correlation with the immediate load-baring capacity. RFA and measuring the cortical bone thickness with X-ray before and during surgery could be an effective diagnosis tool for the success of immediate loading of implant.

• 생물정신의학
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• 제27권1호
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• pp.1-8
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• 2020

Objectives In electroconvulsive therapy (ECT) research and practice, the precise determination of seizure duration is important in the evaluation of clinical relevance of the ECT-induced seizure. In this study, we have developed computerized algorithms to assess the duration of ECT-induced seizure. Methods Subjects included 5 males and 6 females, with the mean age of 33.1 years. Total 55 ECT sessions were included in the analysis. We analyzed the standard deviation of a finite block of electroencephalography (EEG) data and the change in the local slope of RR intervals in electrocardiography (ECG) signals during ECT-induced seizure. And then, we compared the calculated seizure durations from EEG recording (EEG algorithm) and ECG recording (ECG algorithm) with values determined by consensus of clinicians based on the recorded EEG (EEG consensus), as a gold standard criterion, in order to testify the computational validity of our algorithms. Results The mean seizure durations calculated by each method were not significantly different in sessions with abrupt flattened postictal suppression and in sessions with non-abrupt flattened postictal suppression. The intraclass correlation coefficients (95% confidence interval) of the three methods (EEG algorithm, ECG algorithm, EEG consensus) were significant in the total sessions [0.79 (0.70-0.86)], the abrupt flattened postictal suppression sessions [0.84 (0.74-0.91)], and the non-abrupt flattened postictal suppression sessions [0.67 (0.45-0.84)]. Correlations between three methods were also statistically significant, regardless of abruptness of transition. Conclusions Our proposed algorithms could reliably measure the duration of ECT-induced seizure, even in sessions with non-abrupt transitions to flat postictal suppression, in which it is typically difficult to determine the seizure duration.

• Journal of Ginseng Research
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• 제44권5호
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• pp.697-703
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• 2020

Background: GS-3K8 and GINST, both of which are modified ginseng extracts, have never been examined in terms of their effectiveness for the prevention of acute respiratory illness (ARI) in humans. We conducted a pilot study to assess the feasibility of performing a large-scale, randomized, controlled trial. Methods: This study was a randomized, double-blind, placebo-controlled, pilot study at a single center from October 2014 to March 2015. The 45 healthy applicants were randomly divided into the GS-3K8 (n = 15), GINST (n = 15), and placebo groups (n = 15). The study drug was administered as a capsule (500 mg/cap and 3000 mg/day). GS-3K8 contained 6.31 mg/g of Rg1, 15.05 mg/g of Re, 30.84 mg/g of Rb1, 15.02 mg/g of Rc, 12.44 mg/g of Rb2, 6.97 mg/g of Rd, 1.59 mg/g of Rg3, 3.25 mg/g of Rk1, and 4.84 mg/g of Rg5. GINST contained 7.54 mg/g of Rg1, 1.87 mg/g of Re, 5.42 mg/g of Rb1, 0.29 mg/g of Rc, 0.36 mg/g of Rb2, 0.70 mg/g of Rd, and 6.3 mg/g of compound K. The feasibility criteria were the rates of recruitment, drug compliance, and successful follow-up. The primary clinical outcome measure was the incidence of ARI. The secondary clinical outcome measures were the duration of symptoms. Results: The rate of recruitment was 11.3 participants per week. The overall rate of completed follow-up was 97.8%. The mean compliance rate was 91.64 ± 9.80%, 95.28 ± 5.75%, and 89.70 ± 8.99% in the GS-3K8, GINST, and placebo groups, respectively. The incidence of ARI was 64.3% (9/14; 95% confidence interval [CI], 31.4-91.1%), 26.7% (4/15; 95% CI, 4.3-49.0%), and 80.0% (12/15; 95% CI, 54.8-93.0%) in the GS-3K8, GINST, and placebo groups, respectively. The average days of symptoms were 3.89 ± 4.65, 9.25 ± 7.63, and 12.25 ± 12.69 in the GS-3K8, GINST, and placebo groups, respectively. Conclusion: The results support the feasibility of a full-scale trial. GS-3K8 and GINST appear to have a positive tendency toward preventing the development of ARI and reducing the symptom duration. A randomized controlled trial is needed to confirm these findings.

• Clinical and Experimental Reproductive Medicine
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• 제47권2호
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• pp.147-152
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• 2020

Objective: The purpose of this study was to determine the effect of vaginal progesterone for luteal phase support (LPS) on the clinical pregnancy rate (CPR) in natural frozen embryo transfer (FET) cycles via a meta-analysis. Methods: We performed a meta-analysis of randomized controlled trials (RCTs) and retrospective studies that met our selection criteria. Four online databases (PubMed, Embase, Medline, and the Cochrane Library) were searched between January 2017 and May 2017. Studies were selected according to predefined inclusion criteria and meta-analyzed using R software version 2.14.2. The main outcome measure was CPR. Results: A total of 18 studies were reviewed and assessed for eligibility. One RCT (n = 435) and three retrospective studies (n = 3,033) met the selection criteria. In a meta-analysis of the selected studies, we found no significant difference in the CPR (odds ratio [OR], 0.96; 95% confidence interval [CI], 0.60-1.55) between the vaginal progesterone and control groups. An analysis of the two retrospective cohort studies that reported the live birth rate (LBR) following FET showed a significantly higher LBR in the vaginal progesterone group (OR, 1.72; 95% CI, 1.21-2.46). A subgroup meta-analysis of FET conducted 5 days after injection of human chorionic gonadotropin showed no significant differences between the two groups with regard to the CPR (OR, 1.18; 95% CI, 0.90-1.55) or miscarriage rate (OR, 0.73; 95% CI, 0.36-1.47). Conclusion: The results of this meta-analysis of the currently available literature suggest that LPS with vaginal progesterone in natural FET cycles does not improve the CPR.

• 대한치과기공학회지
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• 제35권4호
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• pp.405-414
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• 2013

Purpose: The purpose of this study was to examine the relationship of the general characteristics of health-related majors to their life expectancy scale, depression scale, health perception scale, subjective wellbeing scale, somatic symptom scale and college life stress scale. And it's also meant to analyze influential factors for their stress about college life. Methods: The subjects in this study were the students who were in the department of dental laboratory technology and the department of dental hygiene at a college located in the region of Iksan, North Jeolla Province. Data were gathered in November and December, 2012. The life expectancy scale, depression scale, health perception scale, subjective wellbeing scale, physical symptom scale, somatic symptom scale and college life stress scale of the general characteristics were analyzed by t-test and one way analyses of variance (ANOVA) and the Duncan's multiple range test at the 95% confidence level to assess the statistical significance. And stepwise multiple regression analysis was conducted to determine what factors would affect the stress of the students about college life. The data were analyzed with the windows ver. 12.0(SPSS GmbH, Germany) statistical software program. Results: Among the general characteristics, there were significant differences according to gender and age in all the variables that were life expectancy scale, depression scale, health perception scale, subjective wellbeing scale, physical symptom scale and college life stress scale. 61.3% of the students responded they slept for six hours or less, and the respondents who slept for six hours or less scored significantly statistically lower in health perception scale, subjective wellbeing scale and physical symptom scale. As for college life stress, the respondents who got depressed more often, whose subjective peace or happiness was lower, whose life expectancy was lower, who had worse physical symptoms, whose living standard was lower and whose academic year was lower were under heavier stress about their college lives. Conclusion: As the worse physical health and worse mental health(life expectancy, depression, health perception, subjective wellbeing and physical symptoms, etc.) of the college students led to heavier stress about college life, how to promote their physical health and mental health should discreetly be considered, and every necessary measure should be taken to improve their physical and mental health.

• Journal of Astronomy and Space Sciences
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• 제19권4호
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• pp.305-318
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• 2002

한반도 상공의 중간 자외선 대기광을 측정하기 위해 3단형 과학로켓(KSR-III)에 탑재될 대기광도계(Airglow Photometer, AGP)가 제작되었다. 대기광도계 비행 모형(FM)은 4-channel로 이루어져 100km~300km 구간의 중간 자외선 영역의 OI 2972${\AA}$, $N_2$ VK(0,6) 2780${\AA}$, $N_2$ 2PG 3150${\AA}$ 대기광과 배경으로 3070${\AA}$을 지평선 방향으로 측정하게 된다. 대기광도계는 광도계 본체, 차폐경(Baffle), 전자제어부, 전원공급기로 구성되어 있다. 광도계 본체는 협대역 간섭 필터를 통해 선택된 파장의 대기광을 직경 2.5cm 렌즈로 초점면에 설치된 실틈(slit)을 통해 자외선 감지용 광전증배관으로 진입시키는 구조로 되어있다. 비행중 영점 측정을 위해 초점면 실틈 뒤편의 회전판에 영점광원을 설치하였다. 차폐경은 저충대기로부터 산란되는 태양광이 광도계로 진입하지 못하도록 성능을 최적화하여 설계 제작되었다. 대기광도계 비행모형의 지상 테스트로서 각광도계의 성능 테스트 및 감응도, 영점 측정 등을 실시하였다. 대기광도개가 미약한 빛을 감응하도록 제작되었기 때문에 국내에서 신뢰도를 갖고 절대 감응도를 결정할 수 없었다. 그러나 대기광도계 각 channel 간 상대 감응도 측정값은 안정되게 측정되었기 때문에, 추후 로켓 비행시 측정한 자료를 신뢰성있게 분석할 수 있을 것으로 기대된다.

• 한국가스학회지
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• 제25권4호
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• pp.49-56
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• 2021

액화석유가스(Liquefied Petroleum Gas)는 Propane(C₃H₈)과 Butane(C₄H₁₀)을 주성분으로 한 가스를 액화한 것으로 구분된다. LPG는 혼합 성분에 따라 품질의 차이가 커 성분 함량을 정확하게 측정하는 것이 중요하다. 이와 같은 물질은 혼합물의 성분별로 상온에서는 액체와 기체가 같이 공존해 정확한 측정이 까다롭다. 따라서 탄화수소의 성분별 농도의 측정 불확도가 높아 실제 함량 기준과 많은 차이가 발생하는 문제점을 안고 있다. 그러므로 탄화수소 물질의 조성과 정확한 농도 측정을 위해 혼합 액체 프로판 표준가스의 개발이 필요하였다. 혼합 액체 프로판 표준가스는 ISO-6142(2015)의 중량법으로 벨로즈형 정압실린더에 제조되었다. 제조한 4병의 표준가스에서 균질성이 GC-FID로 확인되었다. 제조 상대확장불확도는 0.01 % - 0.30 %, 균질성은 0.03 % - 0.25 %이었다. 이 혼합 액체 프로판 표준가스에서 중량법, 제조 일치성, 실린더 흡착 여부 및 장기 안정성에 대한 상대확장불확도는 0.26 % - 1.39 %(신뢰도 약 95 %, k=2)이내로 개발되었다.

• 한국산학기술학회논문지
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• 제22권1호
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• pp.520-530
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• 2021

목표: 본 연구는 음악요법이 치매 노인의 인지기능, 초조행동, 불안, 우울에 미치는 영향을 규명하는 것을 목적으로 한다. 방법: 2010년부터 2019년까지 PubMed, EMBASE, Cochrane Library, CINAHL, Web of Science, Google scholar, PsycINFO에서 종합적인 문헌검색을 하였고 메타분석에서는 RevMan 5.4 프로그램을 사용하여 표준화된 평균 차이(Hedge's g)와 95% 신뢰 구간은 요약 측정으로 산출하고 랜덤 효과 모델과 역분산 방법을 적용하였다. 총 13개의 연구가 포함되었으며, 모두 오류 위험 평가를 위한 코크란 평가도구를 근거로 질 평가를 하였다. 결과: 효과 크기(Hedge's g)는 1차 결과 변수인 인지기능 0.31[95% CI:-0.02, 0.65], 초조행동 -0.03[95% CI: -0.17, 0.11], 2차 결과 변수인 불안 -0.61[95% CI: -1.17, -0.05], 우울 -0.44[95% CI: -0.88, 0.00]이었다. 음악중재 유형별 하위그룹 분석 결과 복합음악요법이 치매 환자의 인지기능(g=0.45[95% CI: 0.03, 0.87])에 유의한 증가 효과가 있는 것으로 나타났다. 결론: 음악요법은 불안과 우울을 감소시키는 데 유의한 효과를 보였으며, 복합음악치료는 치매 환자의 인지기능 개선 효과를 보였다.

• Journal of Chest Surgery
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• 제54권6호
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• pp.480-486
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• 2021

Background: Although various methods are already used to calculate predicted postoperative forced expiratory volume in 1 second (FEV₁) based on preoperative FEV₁ in lung surgery, the predicted postoperative FEV₁ is not always the same as the actual postoperative FEV₁. Observed postoperative FEV₁ values are usually the same or higher than the predicted postoperative FEV₁. To overcome this issue, we investigated the relationship between the number of resected lung segments and the discordance of preoperative and postoperative FEV₁ values. Methods: From September 2014 to May 2020, the data of all patients who underwent anatomical lung resection by video-assisted thoracoscopic surgery (VATS) were gathered and analyzed retrospectively. We investigated the association between the number of resected segments and the differential FEV₁ (a measure of the discrepancy between the predicted and observed postoperative FEV₁) using the t-test and linear regression. Results: Information on 238 patients who underwent VATS anatomical lung resection at Kyung Hee University Hospital at Gangdong and by DH. Kim for benign and malignant disease was collected. After applying the exclusion criteria, 114 patients were included in the final analysis. In the multiple linear regression model, the number of resected segments showed a positive correlation with the differential FEV₁ (Pearson r=0.384, p<0.001). After adjusting for multiple covariates, the differential FEV₁ increased by 0.048 (95% confidence interval, 0.023-0.073) with an increasing number of resected lung segments (R²=0.271, p<0.001). Conclusion: In this study, after pulmonary resection, the number of resected segments showed a positive correlation with the differential FEV₁.

• Korean Journal of Radiology
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• 제25권4호
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• pp.351-362
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• 2024

Objective: To measure inter-reader agreement and identify associated factors in interpreting complete response (CR) on magnetic resonance imaging (MRI) following chemoradiotherapy (CRT) for rectal cancer. Materials and Methods: This retrospective study involved 10 readers from seven hospitals with experience of 80-10210 cases, and 149 patients who underwent surgery after CRT for rectal cancer. Using MRI-based tumor regression grading (mrTRG) and methods employed in daily practice, the readers independently assessed mrTRG, CR on T2-weighted images (T2WI) denoted as mrCR_T2W, and CR on all images including diffusion-weighted images (DWI) denoted as mrCR_overall. The readers described their interpretation patterns and how they utilized DWI. Inter-reader agreement was measured using multi-rater kappa, and associated factors were analyzed using multivariable regression. Correlation between sensitivity and specificity of each reader was analyzed using Spearman coefficient. Results: The mrCR_T2W and mrCR_overall rates varied widely among the readers, ranging 18.8%-40.3% and 18.1%-34.9%, respectively. Nine readers used DWI as a supplement sequence, which modified interpretations on T2WI in 2.7% of cases (36/1341 [149 patients × 9 readers]) and mostly (33/36) changed mrCR_T2W to non-mrCR_overall. The kappa values for mrTRG, mrCR_T2W, and mrCR_overall were 0.56 (95% confidence interval: 0.49, 0.62), 0.55 (0.52, 0.57), and 0.54 (0.51, 0.57), respectively. No use of rectal gel, larger initial tumor size, and higher initial cT stage exhibited significant association with a higher interreader agreement for assessing mrCR_overall (P ≤ 0.042). Strong negative correlations were observed between the sensitivity and specificity of individual readers (coefficient, -0.718 to -0.963; P ≤ 0.019). Conclusion: Inter-reader agreement was moderate for assessing CR on post-CRT MRI. Readers' varying standards on MRI interpretation (i.e., threshold effect), along with the use of rectal gel, initial tumor size, and initial cT stage, were significant factors associated with inter-reader agreement.