• Journal of Industrial Convergence
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• v.22 no.2
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• pp.143-151
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• 2024

This study compared the health behaviors, health related clinical characteristics between individuals with Glycated Hemoglobin A1C≧6.5% and < 6.5% in 30~59yr. Factors that were associated with A1C were identified by sex, health behaviors, health literacy. This study was an observational study with a cross-sectional design based on data from 2019~2021 Korea National Health and Nutrition Examination Survey. Multiple logistic regression analysis was employed to compute the odds ratios of health behaviors to identify the risk factors for Glycated Hemoglobin. The prevalence of A1C≧6.5% among the total was 79.4%(weighted %, n=348). In the A1C≧6.5%, 71.8% were men. In univariate logistic regression for A1C≧6.5%, sex, duration with diabetes, and body mass index(BMI) were influencing factors. In multiple logistic regression by sex, the factors associated with A1C≧6.5 in women were as follows: education(OR 4.5; 95% CI:1.1, 18.5), duration with diabetes(OR 2.9; 95% CI 1.1, 7.9). Strategies should be targeted to improve health behaviors and clinical characteristics for those in their sex, women in low education level, duration with diabetes. Moreover, healthcare providers should understand the barriers to health behaviors and health literacy to effectively deliver healthcare service.

• Korean Journal of Radiology
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• v.22 no.4
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• pp.624-633
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• 2021

Objective: To evaluate the reliability of CT measurements of muscle quantity and quality using variable CT parameters. Materials and Methods: A phantom, simulating the L2-4 vertebral levels, was used for this study. CT images were repeatedly acquired with modulation of tube voltage, tube current, slice thickness, and the image reconstruction algorithm. Reference standard muscle compartments were obtained from the reference maps of the phantom. Cross-sectional area based on the Hounsfield unit (HU) thresholds of muscle and its components, and the mean density of the reference standard muscle compartment, were used to measure the muscle quantity and quality using different CT protocols. Signal-to-noise ratios (SNRs) were calculated in the images acquired with different settings. Results: The skeletal muscle area (threshold, -29 to 150 HU) was constant, regardless of the protocol, occupying at least 91.7% of the reference standard muscle compartment. Conversely, normal attenuation muscle area (30-150 HU) was not constant in the different protocols, varying between 59.7% and 81.7% of the reference standard muscle compartment. The mean density was lower than the target density stated by the manufacturer (45 HU) in all cases (range, 39.0-44.9 HU). The SNR decreased with low tube voltage, low tube current, and in sections with thin slices, whereas it increased when the iterative reconstruction algorithm was used. Conclusion: Measurement of muscle quantity using HU threshold was reliable, regardless of the CT protocol used. Conversely, the measurement of muscle quality using the mean density and narrow HU thresholds were inconsistent and inaccurate across different CT protocols. Therefore, further studies are warranted in future to determine the optimal CT protocols for reliable measurements of muscle quality.

• Korean Journal of Radiology
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• v.22 no.5
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• pp.770-781
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• 2021

Objective: Chemical exchange-dependent saturation transfer (CEST) MRI is sensitive for detecting solid-like proteins and may detect changes in the levels of mobile proteins and peptides in tissues. The objective of this study was to evaluate the characteristics of chemical exchange proton pools using the CEST MRI technique in patients with dementia. Materials and Methods: Our institutional review board approved this cross-sectional prospective study and informed consent was obtained from all participants. This study included 41 subjects (19 with dementia and 22 without dementia). Complete CEST data of the brain were obtained using a three-dimensional gradient and spin-echo sequence to map CEST indices, such as amide, amine, hydroxyl, and magnetization transfer ratio asymmetry (MTR_asym) values, using six-pool Lorentzian fitting. Statistical analyses of CEST indices were performed to evaluate group comparisons, their correlations with gray matter volume (GMV) and Mini-Mental State Examination (MMSE) scores, and receiver operating characteristic (ROC) curves. Results: Amine signals (0.029 for non-dementia, 0.046 for dementia, p = 0.011 at hippocampus) and MTR_asym values at 3 ppm (0.748 for non-dementia, 1.138 for dementia, p = 0.022 at hippocampus), and 3.5 ppm (0.463 for non-dementia, 0.875 for dementia, p = 0.029 at hippocampus) were significantly higher in the dementia group than in the non-dementia group. Most CEST indices were not significantly correlated with GMV; however, except amide, most indices were significantly correlated with the MMSE scores. The classification power of most CEST indices was lower than that of GMV but adding one of the CEST indices in GMV improved the classification between the subject groups. The largest improvement was seen in the MTR_asym values at 2 ppm in the anterior cingulate (area under the ROC curve = 0.981), with a sensitivity of 100 and a specificity of 90.91. Conclusion: CEST MRI potentially allows noninvasive image alterations in the Alzheimer's disease brain without injecting isotopes for monitoring different disease states and may provide a new imaging biomarker in the future.

• Journal of The Korean Association For Science Education
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• v.26 no.6
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• pp.753-764
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• 2006

The concept of blood circulation is so complex, dynamic and abstract that students have difficulty in understanding it and students' preconceptions hardly change into scientific concepts even after the lessons. The purpose of this study is to examine middle school, high school, and undergraduate students' understanding of blood circulation and to find the reason why the lack of deep understanding is displayed in students' explanations for the blood circulation. The study consists of three parts. First, the test was designed to investigate students' ideas for blood circulation as components of the structure, the function, the behavior and the mechanism. Second, the test was applied to 7th, 10th and 13th graders to investigate the students' understanding of blood circulation and categorize the types of students' blood circulation model according to their academic level. Finally, the concepts the students had little understanding of were analyzed to decide which ontological category they fell into and further to inquire the characteristics of each concept. The results showed that many students comprehend the structure and the function of blood circulation components well, and there was no significant difference in students' understanding according to the academic level. In contrast, understanding the behavior and the mechanism of circulatory components has remarkably improved in high school students and undergraduates majoring in science and engineering. Also, students' blood circulation models were classified into seven different types. High school students and undergraduates majoring in science and engineering demonstrated a significantly higher percentage on the type of double-loop-branch compared to other academic levels. In addition, it was found that the lack of deep understanding was caused by students' misconceiving the 'equilibrium' category as 'event' category.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.3
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• pp.219-224
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• 2007

Two monitoring buoys equipped with ADCP were deployed at the deepest positions along the trough of the central Gwangyang Bay in spring 2006 in order to study the circulation in the bay. Northward velocity is commonly dominant at both stations located in the eastern part of the channel, which supports the cyclonic circulation accompanied by the southward flow in the western part. The southern station has a distinct two-layer structure with current reversal at 14 m depth and increasing northward velocity in the lower layer to 36 m depth close to the bottom. At the northern station the northward flow becomes accelerated due to the decrease in the cross-sectional area and this northward current is dominant even in the upper layer. In the modal structure from the EOF analysis, the first mode has 74% of total variance at the northern station whereas it is 67% but the baroclinic portion increases at the southern station. The typical northward velocity is about 10 cm/s which is associated with the cyclonic circulation. Subtidal variability due to the local wind effect is negligible, but the nonlocal response associated with offshore Ekman flux by the zonal wind is found during strong wind events.

• Korean Journal of Agricultural Science
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• v.50 no.4
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• pp.809-815
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• 2023

This study was conducted to find out the correlation between meat quality and muscle fat ratio in pork part meat (pork belly and shoulder butt) using CT (computed tomography) imaging technique. After 24 hours from slaughter, pork loin and belly were individually prepared from the left semiconductors of 26 pigs for CT measurement. The image obtained from CT scans was checked through the picture archiving and communications system (PACS). The volume of muscle and fat in the pork belly and shoulder butt of cross-sectional images taken by CT was estimated using Vitrea workstation version 7. This assemblage was further processed through Vitrea post-processing software to automatically calculate the volumes (Fig. 1). The volumes were measured in milliliters (mL). In addition to volume calculation, a three-dimensional reconstruction of the organ under consideration was generated. Pearson's correlation coefficient was analyzed to evaluate the relationship by region (pork belly, pork shoulder butt), and statistical processing was performed using GraphPad Prism 8. The muscle-fat ratios of pork belly taken by CT was 1 : 0.86, while that of pork shoulder butt was 1 : 0.37. As a result of CT analysis of the correlation coefficient between pork belly and shoulder butt compared to the muscle-fat ratio, the correlation coefficient was 0.5679 (R² = 0.3295, p < 0.01). CT imaging provided very good estimates of muscle contents in cuts and in the whole carcass.

• Korean Journal of Radiology
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• v.24 no.4
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• pp.349-361
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• 2023

Objective: To quantitatively assess the pulmonary vasculature using non-contrast computed tomography (CT) in patients with chronic thromboembolic pulmonary hypertension (CTEPH) pre- and post-treatment and correlate CT-based parameters with right heart catheterization (RHC) hemodynamic and clinical parameters. Materials and Methods: A total of 30 patients with CTEPH (mean age, 57.9 years; 53% female) who received multimodal treatment, including riociguat for ≥ 16 weeks with or without balloon pulmonary angioplasty and underwent both non-contrast CT for pulmonary vasculature analysis and RHC pre- and post-treatment were included. The radiographic analysis included subpleural perfusion parameters, including blood volume in small vessels with a cross-sectional area ≤ 5 mm² (BV5) and total blood vessel volume (TBV) in the lungs. The RHC parameters included mean pulmonary artery pressure (mPAP), pulmonary vascular resistance (PVR), and cardiac index (CI). Clinical parameters included the World Health Organization (WHO) functional class and 6-minute walking distance (6MWD). Results: The number, area, and density of the subpleural small vessels increased after treatment by 35.7% (P < 0.001), 13.3% (P = 0.028), and 39.3% (P < 0.001), respectively. The blood volume shifted from larger to smaller vessels, as indicated by an 11.3% increase in the BV5/TBV ratio (P = 0.042). The BV5/TBV ratio was negatively correlated with PVR (r = -0.26; P = 0.035) and positively correlated with CI (r = 0.33; P = 0.009). The percent change across treatment in the BV5/TBV ratio correlated with the percent change in mPAP (r = -0.56; P = 0.001), PVR (r = -0.64; P < 0.001), and CI (r = 0.28; P = 0.049). Furthermore, the BV5/TBV ratio was inversely associated with the WHO functional classes I-IV (P = 0.004) and positively associated with 6MWD (P = 0.013). Conclusion: Non-contrast CT measures could quantitatively assess changes in the pulmonary vasculature in response to treatment and were correlated with hemodynamic and clinical parameters.

• Journal of the Korean Society of Radiology
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• v.82 no.6
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• pp.1534-1544
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• 2021

Purpose To examine the effect of lung volume on the size and volume of pulmonary subsolid nodules (SSNs) measured on CT. Materials and Methods A total of 42 SSNs from 31 patients were included. CT examination was first performed at total lung capacity (TLC), and a section containing the nodule was additionally scanned at tidal volume (TV). The diameter and volume of each SSN, as well as the cross-sectional lung area containing the nodule, were measured. The significance of the changes in measurements between TLC and TV within the same individuals was evaluated. Results The lung area and the diameter and volume of SSNs decreased significantly at TV by 12.7 cm², 0.5 mm, and 46.4 mm³ on average, respectively (p < 0.001), compared to those at TLC. Changes in lung area between TV and TLC were positively correlated with the change in SSN diameter (p = 0.027) and volume (p = 0.014). However, after correction (by considering the change in lung area), the changes in SSN diameter (p = 0.124) and volume (p = 0.062) were not significantly different. Conclusion SSN size and volume can be significantly affected by lung volume during CT scans of the same individuals.

• Archives of Plastic Surgery
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• v.51 no.2
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• pp.251-257
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• 2024

Background Plastic surgery has developed to benefit in a variety of challenging areas formerly handled by other disciplines. Medical students do not have a clear picture of plastic surgery as a career due to lacking scope, clinical practice, and understanding of plastic surgery as a clinical area of expertise, including general practitioners, nursing staff, medical trainees, and the general public, and misconceptions about the extent of reconstructive and plastic surgery. Methods A cross-sectional observational study was conducted on Kuwait University Medical students (2nd-7th Years) over a period of 1 month. A questionnaire and a consent form were provided to eligible students. The inclusion criteria were Kuwait University Medical students from 2nd to 7th Years with signed consent form. The response was collected via email sent in coordination with the Vice Dean of Student Affairs in the Faculty of Medicine. Using statistical package for the social sciences, responses were statistically analyzed. Pearson's chi-square test was used to calculate p-values, where p < 0.05 was considered statistically significant. Results A total of 244 eligible medical students, 121 males and 123 females, were included in the study, with a mean age of 21 (±2) years. Similarly, 126 (51.6%) were preclinical students (2nd-4th-year students), while 118 (48.4%) were clinical students (5th-7th-year students). About 79.8% of medical students believed that plastic surgery plays an essential role in trauma management, whereas 9.2% did not consider plastic surgery significant for trauma management. This study found that only 15.5% of medical students were interested in enrolling in plastic surgery residency after graduation, while 47.1% of students did not consider plastic surgery residency after graduation. However, 37.4% were uncertain. The two most driving factors in deciding on plastic surgery residency were expected income (61.8%) and lifestyle (14.3%). Conclusion Improving medical students' education quality can enhance their perception and awareness of plastic surgery. Students should be taught the broader scope of plastic surgery. The inclusion of formal training during undergraduation is the essence of time and should be added to or improved during plastic surgery rotations with more emphasis on reconstructive and hand/peripheral nerve surgery. Student-led interest groups can be a useful tool for educating students about their specialty.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.27 no.3
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• pp.158-167
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• 2024

Purpose: To evaluate the prevalence of vertebral fracture (VF) in children with chronic liver disease (CLD) with and without liver transplantation (LT) and to determine the associated factors. Methods: A cross-sectional study was conducted. Patients aged 3-21 years with CLD both before and after LT were enrolled in the study. Lateral thoracolumbar spine radiographs were obtained and assessed for VF using Mäkitie's method. Clinical and biochemical data were collected. Results: We enrolled 147 patients (80 females; median age 8.8 years [interquartile range 6.0-11.8]; 110 [74.8%] in the LT group and 37 [25.2%] in the non-LT group). VF was identified in 21 patients (14.3%): 17/110 (15.5%) in the LT group and 4/37 (10.8%) in the non-LT group (p=0.54). Back pain was noted in only three patients with VF. In the univariate analysis, a height z-score below -2.0 (p=0.010), pre-LT hepatopulmonary syndrome (p=0.014), elevated serum direct and total bilirubin levels (p=0.037 and p=0.049, respectively), and vitamin D deficiency at 1-year post-LT (p=0.048) were associated with VF in the LT group. In multivariate analysis, height z-score below -2.0 was the only significant associated factor (odds ratio, 5.94; 95% confidence interval, 1.49-23.76; p=0.012) for VF. All VFs in the non-LT group were reported in males. Conclusion: In children with CLD, VF is common before and after LT. Most patients with VF are asymptomatic. Screening for VF should be considered in patients with a height z-score below -2.0 after LT.