• 대한의용생체공학회:의공학회지
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• 제30권5호
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• pp.393-400
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• 2009

The present study developed a new technique with no physical object on the flow stream but enabling the air flow measurement and easily incorporated with the devices for cardiopulmonary resuscitation(CPR) procedure. A turbulence chamber was formed in the middle of the respiratory tube by locally enlarging the cross-sectional area where the flow related turbulence was generated inducing energy loss which was in turn converted into pressure difference. The turbulence chamber was simply an empty enlarged air space, thus no physical object existed on the flow stream, but still the flow rate could be evaluated. Computer simulation demonstrated stable turbulence formation big enough to measure. Experiment was followed on the proto-type transducer, the results of which were within ${\pm}5%$ error compared to the simulation data. Both inspiratory and expiratory flows were obtained with symmetric measurement characteristics. Quadratic curve fitting provided excellent calibration formula with a correlation coefficient>0.999(P<0.0001) and the mean relative error<1%. The present results can be usefully applied to accurately monitor the air flow rate during CPR.

• Nutrition Research and Practice
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• 제10권4호
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• pp.411-417
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• 2016

BACKGROUND/OBJECTIVES: Metabolic syndrome (MetS) is a set of interrelated metabolic risk factors that increase the risk of cardiovascular morbidity and mortality. Studies regarding the specificity and sensitivity of serum levels of leptin and uric acid as predictors of MetS are limited. The aim of this study was to evaluate the serum levels of leptin and uric acid in terms of their specificity and sensitivity as predictors of MetS in the studied Jordanian group. SUBJECTS/METHODS: In this cross sectional study, 630 adult subjects (308 men and 322 women) were recruited from the King Hussein Medical Center (Amman, Jordan). The diagnosis of MetS was made according to the 2005 International Diabetes Federation criteria. Receiver operating characteristic curves were used to determine the efficacy of serum levels of leptin and uric acid as predictors of MetS in the studied Jordanian group. RESULTS: Study results showed that for identification of subjects with MetS risk, area under the curve (AUC) for leptin was 0.721 and 0.683 in men and women, respectively. Serum uric acid levels in men showed no significant association with any MetS risk factors and no significant AUC, while uric acid AUC was 0.706 in women. CONCLUSION: Serum leptin levels can be useful biomarkers for evaluation of the risk of MetS independent of baseline obesity in both men and women. On the other hand, serum uric acid levels predicted the risk of MetS only in women.

• 대한의용생체공학회:의공학회지
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• 제33권4호
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• pp.169-176
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• 2012

Tumor cell morphology is closely related to its migratory behaviors. An active tumor cell has a highly irregular shape, whereas a spherical cell is inactive. Thus, quantitative analysis of cell features is crucial to determine tumor malignancy or to test the efficacy of anticancer treatment. We use 3D time-lapse phase-contrast microscopy to analyze single cell morphology because it enables to observe long-term activity of living cells without photobleaching and phototoxicity, which is common in other fluorescence-labeled microscopy. Despite this advantage, there are image-level drawbacks to phase-contrast microscopy, such as local light effect and contrast interference ring. Therefore, we first corrected for non-uniform illumination artifacts and then we use intensity distribution information to detect cell boundary. In phase contrast microscopy image, cell is normally appeared as dark region surrounded by bright halo ring. Due to halo artifact is minimal around the cell body and has non-symmetric diffusion pattern, we calculate cross sectional plane which intersects center of each cell and orthogonal to first principal axis. Then, we extract dark cell region by analyzing intensity profile curve considering local bright peak as halo area. Finally, we calculated the Fourier descriptor that morphological characteristics of cell to classify tumor cells into active and inactive groups. We validated classification accuracy by comparing our findings with manually obtained results.

• Journal of Preventive Medicine and Public Health
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• 제43권4호
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• pp.283-291
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• 2010

Objectives: The purpose of this study was to develop a prediction model for future smoking intention among Korean adolescents aged 13 to 15 in order to identify the high risk group exposed to future smoking. Methods: The data was collected from a total of 5940 students who participated in a self-administrated questionnaire of a cross-sectional school-based survey, the 2004 Korea Global Youth Tobacco Survey. Chi-square tests and logistic regression analyses were carried out to identify the relevant determinants associated with intentions of adolescents’ future smoking. Receiver Operation Characteristic (ROC) assessment was applied to evaluate the explanation level of the developed prediction model. Results: 8.4% of male and 7.2% of female participants show their intentions of future smoking. Among non-smoking adolescents; who have past smoking experience [odds ratio (OR) 2.73; 95% confidence interval (CI) 1.92- 3.88]; who have intentions of smoking when close friends offer a cigarette (OR 31.47; 95% CI = 21.50 - 46.05); and who have friends that are mostly smokers (OR 5.27; 95% CI = 2.85 - 9.74) are more likely to be smokers in the future. The prediction model developed from this study consists of five determinants; past smoking experience; parents smoking status; friends smoking status; ownership of a product with a cigarette brand logo; and intentions of smoking from close friends’ cigarette offer. The area under the ROC curve was 0.8744 (95% CI=0.85 - 0.90) for current non-smokers. Conclusions: For efficiency, school-based smoking prevention programs need to be designed to target the high risk group exposed to future smoking through the prediction model developed by the study, instead of implementing the programs for all the students.

• Asian Pacific Journal of Cancer Prevention
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• 제13권8호
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• pp.4199-4202
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• 2012

Objective: The aim of our study is to compare an ovarian malignancy prediction model based on age and four sonographic findings (OMPS1) with a new model called OMPS2 which differs just by adding serum CA125 measurement to (OMPS1). Methods: In a cross sectional comparative study OMPS1 was validated in 830 operated ovarian masses within a 3 years period (2006-2009). Logistic regression analysis was used to construct OMPS2 based on OMPS1 adding serum CA125 findings. The area under the curve for two models was compared in 411 patients. Results: OMPS2 was calculated as follows: OMPS1 + 1.444 (if serum CA125= 36-200) or 3.842 (if serum CA125 is more than 200). AUC of OMPS2 was increased to 84.3% (CI 95% 78.1- 89.8) in comparison to OMPS1 with AUC of 78.1% (CI 95% 71.8-84.5). Conclusion: Our second model is more accurate in prediction of ovarian malignancy, compared with our first model.

• 센서학회지
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• 제18권4호
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• pp.294-300
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• 2009

Cardiopulmonary resuscitation(CPR) is performed by artificial ventilation and thoracic compression for the patient under emergent situation to maintain at least the minimum level of respiration and blood circulation for life survival. Quality of the pre-hospital CPR not only significantly affects the patient's survival rate but also minimizes side effects caused by CPR. Good quality CPR requires monitoring respiration, however, traditional respiratory air flow transducers cannot be used because the transducer elements are located on the flow axis. The present study developed a new technique with no physical object on the flow stream but enabling the air flow measurement and easily incorporated with the CPR devices. A turbulence chamber was formed in the middle of the respiratory tube by locally enlarging the cross-sectional area where the flow related turbulence was generated inducing energy loss which was in turn converted into pressure difference. The turbulence chamber was simply an empty enlarged air space, thus no physical object was placed on the flow stream, but still the flow rate could be evaluated. Both inspiratory and expiratory flows were obtained with symmetric measurement characteristics. Quadratic curve fitting provided excellent calibration formula with a correlation coefficient>0.999 (P<0.0001) and the mean relative error<1 %. The present results can be usefully applied to accurately monitor the air flow rate during CPR.

• Computers and Concrete
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• 제3권4호
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• pp.235-248
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• 2006

This investigation presents an analysis procedure for simulating the compressive behavior of a rectangular concrete column confined by fiber-reinforced plastic (FRP) under uniaxial load. That is, the entire stress-strain curve can be drawn through the present analysis procedure. The modified Mander's stress-strain model (Mander, et al. 1988) and finite element method are adopted in this analysis procedure. The numerical analysis results are compared with the experimental results to verify the accuracy of the analysis procedure. This study offers a useful analysis procedure of researching the compressive behavior of rectangular concrete columns confined by FRP. Two main parameters, the number of FRP layers and the radius of the round corners of a rectangular column, are investigated. The numerical results show that non-uniform stresses occur and reduce the sectional effective area owing to the geometry of the confined rectangular column. The stresses are concentrated at the corners of the rectangular column. Compressive strength of a rectangular column increases greatly because the number of FRP layers increase. The maximum predicted compressive stress of the rectangular column has approximately 10% error as compared to the experimental results. Comparing the numerical and experimental results demonstrates that the accuracy of this analysis procedure is credible. Besides, the stress-strain curves of the R30 models, which are rectangular concrete column with large radius of round corners, are almost bilinear. This calculated results conform to the expectation and show the present analysis procedure are more suitable than Mander's model (1988) to analyze the compressive behavior of the rectangular concrete column confined by FRP.

• Clinical and Experimental Pediatrics
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• 제63권1호
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• pp.20-24
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• 2020

Background: Predicting the prognosis of patients admitted to the pediatric intensive care unit (PICU) is very important in determining further management and resource allocation. The prognostication of critically ill children can be challenging; hence, accurate methods for predicting outcomes are needed. Purpose: To evaluate the role of microalbuminuria at admission as a prognostic marker in comparison to standard Pediatric Risk of Mortality (PRISM) and Pediatric Logistic Organ Dysfunction (PELOD) mortality scores in children admitted to the PICU. Methods: This cross-sectional study was conducted from January 2015 to October 2016. Eighty-four patients aged 1 month to 18 years admitted to the PICU of teaching hospitals for more than 24 hours were enrolled by convenience sampling method. Microalbuminuria was estimated by spot urinary albumin-creatinine ratio. PRISM and PELOD scores were calculated using an online calculator. Outcome measures were PICU length of stay, inotrope usage, multiorgan dysfunction, and survival. ACR was compared with mortality scores for predicting survival. Results: Microalbuminuria was present in 79.8% with a median value of 85 mg/g (interquartile range, 41.5-254 mg/g). A positive correlation was found between albumin-creatinine ratio and PICU length of stay (P=0.013, r=0.271). Albumin-creatinine ratio was significantly associated with organ dysfunction (P=0.004) and need for inotropes (P=0.006). Eight deaths were observed in the PICU. The area under the curve for mortality for albumin-creatinine ratio (0.822) was comparable to that for PRISM (0.928) and PELOD (0.877). Albumin-creatinine ratio >109 mg/g predicted mortality with a sensitivity of 87.5% and specificity of 63.2%. Conclusion: Microalbuminuria is a good predictor of PICU outcomes comparable with mortality scores.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제25권1호
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• pp.30-40
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• 2022

Purpose: Pediatric acute appendicitis has a stable incidence rate in Western countries with an annual change of -0.36%. However, a sharp increase was observed in the Asian region. The Indonesian Health Department reveals appendicitis as the fourth most infectious disease, with more than 64,000 patients annually. Hence, there is an urgent need to identify and evaluate the risk factors and diagnostic modalities for accurate diagnosis and early treatment. This study also clarifies the usage of pediatric appendicitis score (PAS) for children <5 years of age. Methods: The current study employed a cross-sectional design with purposive sampling through demographic and PAS questionnaires with ultrasound sonography (USG) results. The analysis was performed using the chi-square and Mann-Whitney tests and logistic regression. Results: This study included 21 qualified patients with an average age of 6.76±4.679 years, weighing 21.72±10.437 kg, and who had been hospitalized for 4.24±1.513 days in Siloam Teaching Hospital. Compared to the surgical gold standard, PAS and USG have moderate sensitivity and specificity. Bodyweight and stay duration were significant for appendicitis (p<0.05); however, all were confounders in the multivariate regression analysis. Incidentally, a risk prediction model was generated with an area under the curve of 72.73%, sensitivity of 100.0%, specificity of 54.5%, and a cut-off value of 151. Conclusion: PAS outperforms USG in the sensitivity of diagnosing appendicitis, whereas USG outperforms PAS in terms of specificity. This study demonstrates the use of PAS in children under 5 years old. Meanwhile, no risk factors were significant in multivariate pediatric acute appendicitis risk factors.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제27권1호
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• pp.53-61
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• 2024

Purpose: Although the 24-hours urinary copper excretion is useful for the diagnosis of Wilson disease (WD), there are practical difficulties in the accurate and timed collection of urine samples. The purpose of this study was to verify if the spot morning urinary Copper/Zinc (Cu/Zn) ratio could be used as a replacement parameter of 24-hours urinary copper excretion in the diagnosis of WD. Methods: A cross-sectional study was conducted at the Department of Pediatric Gastroenterology and Nutrition, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh, from June 2019 to May 2021 on 67 children over three years of age who presented with liver disease. Twenty-seven children who fulfilled the inclusion criteria for WD were categorized into the test group, and the remaining forty children were considered to have non-Wilsonian liver disease and were categorized into the control group. Along with other laboratory investigations, spot morning urinary samples were estimated for the urinary Cu/Zn ratio in all patients and were compared to the 24-hour urinary copper excretion. The diagnostic value of the Cu/Zn ratio was then analyzed. Results: Correlation of spot morning urinary Cu/Zn ratio with 24-hours urinary copper excretion was found to be significant (r=0.60). The area under ROC curve with 95% confidence interval of morning urinary Cu/Zn ratio measured using 24-hours urine sample was 0.84 (standard error, 0.05; p<0.001). Conclusion: Spot morning urinary Cu/Zn ratio seems to be a promising parameter for the replacement of 24-hours urinary copper excretion in the diagnosis of WD.