• Analytical Science and Technology
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• v.33 no.1
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• pp.23-32
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• 2020

Methamphetamine (MA) is the most common and available drug of abuse in Korea and its primary metabolite is amphetamine (AP). Detection of AP derivatives, such as MA, AP, phentermine (PT), MDA, MDMA, and MDEA by the use of immunoassay screening is not reliable and accurate due to cross-reactivity and insufficient specificity/sensitivity. Therefore, the analytical process accepted by most urine drug-testing programs employs the two-step method with an initial screening test followed by a more specific confirmatory test if the specimen screens positive. In this study, a gas chromatography-mass spectrometric (GC-MS) method was developed and validated for confirmation of MA and AP in human urine. Urine sample (500 µL) was added with N-isopropylbenzylamine as internal standard and ethyl chloroformate as a derivatization reagent, and then extracted with 200 µL of ethyl acetate. Extracted samples were analysed with GC-MS in the SIM/ Scan mode, which were screened by Cobas c311 analyzer (Roche/Hitachi) to evaluate the efficiency as well as the compatibility of the GC-MS method. Qualitative method validation requirements for selectivity, limit of detection (LOD), precision, accuracy, and specificity/sensitivity were examined. These parameters were estimated on the basis of the most intense and characteristic ions in mass spectra of target compounds. Precision and accuracy were less than 5.2 % (RSD) and ±14.0 % (bias), respectively. The LODs were 3 ng/mL for MA and 1.5 ng/mL for AP. At the screening immunoassay had a sensitivity of 100% and a specificity of 95.1 % versus GC-MS for confirmatory testing. The applicability of the method was tested by the analysis of spiked urine and abusers' urine samples.

• Journal of Sasang Constitutional Medicine
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• v.23 no.4
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• pp.471-486
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• 2011

1. Objectives The purpose of this study was to investigate the high-sensitivity C-reactive protein (hsCRP) related characteristics found in each Sasang Constitutional type. 2. Methods This cross-sectional epidemiological study was conducted using data from 2,842 men and women. After typing each participant into one of the four Sasang constitutional types, they were analyzed on various cardiovascular disease-related variables. 3. Results 1) The predictors of cardiovascular disease (metabolic syndrome, high risk FRS group, high risk hsCRP group) was found to show the highest prevalence in the Taeeum type. 2) In the group with metabolic syndrome, the mean hsCRP concentration in the Taeeum and Soyang types were higher than in the Soeum type. In the group without metabolic syndrome, the mean hsCRP concentration in the Taeeum type were higher than in the Soyang and Soeum types. 3) In the FRS low risk group, the mean hsCRP concentration were higher in order of Taeeum type > Soyang type > Soeum type. In the FRS high risk group, the mean hsCRP concentrations were not significantly different among the Sasang constitutional types. 4. Conclusions The results of this study suggest that the Taeeum constitutional type is a risk factor for high hsCRP and cardiovascular disease. These findings suggest that the prevention of cardiovascular disease is more important in the Taeeum type compared to other constitutional types. Moreover, preventive measures are warranted even in the Taeeum-type persons with low clinical cardiovascular risk.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.5
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• pp.1907-1910
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• 2012

Background: Breast cancer is the most prevalent cancer and the fifth cause of cancer death in Iranian women. Early detection and treatment are important for appropriate management of this disease. Mammography and ultrasonography are used for screening and evaluation of symptomatic cases and the main diagnostic test for breast cancer is pathological. In this study we evaluated mammography and ultrasonography as diagnostic tools. Methods: In this cross-sectional study 384 mammography and ultrasonography reports for 255 women were assessed, divided into benign and malignant groups. Suspected cases were referred for pathology evaluation. The radiologic and pathologic reports were compared and also comparison was performed based on age groups (more and less than 50 years old), history of breastfeeding and gravidity. Statistical analysis was performed by SPSS. Results: The mean ages of malignant and benign cases were $49{\pm}11.6$ and $43{\pm}11.2$ years, respectively. Sensitivity and specificity for mammography were 73% and 45%, respectively. Sensitivity and specificity for ultrasonography were 69% and 49%, respectively. There were statistical differences between specificity of mammography in patients based on factors such as history of gravidity, breastfeeding and sensitivity in patients equal or more than 50 years old and less. Conclusion: Factors affecting different results in mammography and ultrasonography reports were classified into three groups, consisting of skill, experience and training of medical staff, and setting of instruments. It is recommended that health managers in developing countries pay attention the quality of setting and man power more than current status. Policy-makers and managers must establish guidelines regarding breast imaging in Iran.

• Korean Journal of Materials Research
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• v.20 no.8
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• pp.408-411
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• 2010

Indium doped $SnO_2$ thick films for gas sensors were fabricated by a screen printing method on alumina substrates. The effects of indium concentration on the structural and morphological properties of the $SnO_2$ were investigated by X-ray diffraction and Scanning Electron Microscope. The structural properties of the $SnO_2$:In by X-ray diffraction showed a (110) dominant $SnO_2$ peak. The size of $SnO_2$ particles ranged from 0.05 to $0.1\;{\mu}m$, and $SnO_2$ particles were found to contain many pores, according to the SEM analysis. The thickness of the indium-doped $SnO_2$ thick films for gas sensors was about $20\;{\mu}m$, as confirmed by cross sectional SEM image. Sensitivity of the $SnO_2$:In gas sensor to 2000 ppm of $CO_2$ gas and 50 ppm of H2S gas was investigated for various indium concentrations. The highest sensitivity to $CO_2$ gas and H2S gas of the indium-doped $SnO_2$ thick films was observed at the 8 wt% and 4 wt% indium concentration, respectively. The good sensing performances of indium-doped $SnO_2$ gas sensors to $CO_2$ gas were attributed to the increase of oxygen vacancies and surface area in the $SnO_2$:In. The $SnO_2$:In gas sensors showed good selectivity to $CO_2$ gas.

• Journal of the Korean Magnetics Society
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• v.22 no.6
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• pp.200-203
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• 2012

In this study, we have investigated that the operation frequency dependences of the output properties of the orthogonal fluxgate sensor which was fabricated with a ferrite core. An orthogonal fluxgate sensor should be operated in as high as possible frequency to enhance its sensitivity in the case of small sized sensor, because sensitivity of the sensor is proportional to cross section area, winding number and operation frequency. In this study, we investigated the correspondence of the frequency dependence of output and the reactance (inductance and capacitance) of pickup coil and cable. Experimental results represented that we could obtain maximum output (= sensitivity) at optimal frequency which is near LC resonance frequency of the pickup coil and cable.

• Journal of Digital Convergence
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• v.17 no.7
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• pp.179-186
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• 2019

This study was to investigate the factors influencing colorectal cancer(CRC) screening behavior using the health belief model(HBM). It was a descriptive cross-sectional survey. A total of 148 adults aged 50 or older participants were surveyed using structured questionnaires including general characteristics,, health beliefs, and behavioral variables. The data were analyzed by descriptive statistics, t-test, chi-square test and multiple logistic regression using SPSS/WIN 25.0 program. The significant factors influecing CRC screening behavior were perceived sensitivity, spousal experience of CRC screening and family history. Therefore, in order to improve the CRC screening rate, it is necessary to increase the perceived sensitivity through systematic education about the importance of early CRC screening. In addition, it is necessary to assess the spousal screening experience and the family history of subjects and to develop the education program using the partnership of the couple.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.25 no.1
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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.

• Geomechanics and Engineering
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• v.30 no.3
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• pp.259-272
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• 2022

Rockburst is a dynamic, multivariate, and non-linear phenomenon that occurs in underground mining and civil engineering structures. Predicting rockburst is challenging since conventional models are not standardized. Hence, machine learning techniques would improve the prediction accuracies. This study describes decision based uncertainty models to predict rockburst in underground engineering structures using gradient boosting algorithms (GBM). The model input variables were uniaxial compressive strength (UCS), uniaxial tensile strength (UTS), maximum tangential stress (MTS), excavation depth (D), stress ratio (SR), and brittleness coefficient (BC). Several models were trained using different combinations of the input variables and a 3-fold cross-validation resampling procedure. The hyperparameters comprising learning rate, number of boosting iterations, tree depth, and number of minimum observations were tuned to attain the optimum models. The performance of the models was tested using classification accuracy, Cohen's kappa coefficient (k), sensitivity and specificity. The best-performing model showed a classification accuracy, k, sensitivity and specificity values of 98%, 93%, 1.00 and 0.957 respectively by optimizing model ROC metrics. The most and least influential input variables were MTS and BC, respectively. The partial dependence plots revealed the relationship between the changes in the input variables and model predictions. The findings reveal that GBM can be used to anticipate rockburst and guide decisions about support requirements before mining development.

• The Journal of Korean Academy of Sensory Integration
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• v.19 no.3
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• pp.13-21
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• 2021

Objective : The purpose of this study was to investigate the sensory processing factors that contribute to the temperament and character traits in early childhood. Methods : In this cross-sectional study, caregivers of typically developing children aged 3-6 years responded to the Sensory Profile and the Junior Temperament and Character Inventory. Multiple regression analysis was performed with temperament and character traits as criterion variables and sensory processing quadrants as predictive variables. Results : Sensory sensitivity significantly predicted novelty seeking and cooperativeness. The high frequency of sensory sensitivity behavior was related to high novelty seeking and low cooperativeness. Conclusion : This study demonstrated that sensory sensitivity contributes to the novelty seeking temperament and cooperativeness character in early childhood.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.4
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• pp.2627-2630
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• 2013

Background: Ovarian cancer continues to pose a major challenge to physicians and radiologists. It is the third most common gynecologic malignancy and estimated to be fifth leading cancer cause of death in women, constituting 23% of all gynecological malignancies. Multi-detector computed tomography (MDCT) appears to offer an excellent modality in diagnosing ovarian cancer based on combination of its availability, meticulous technique, efficacy and familiarity of radiologists and physicians. The aim of this study was to compute sensitivity, specificity, positive and negative predictive values and diagnostic accuracy of 64-slice MDCT in classifying ovarian masses; 95% confidence intervals were reported. Materials and Methods: We prospectively designed a cross-sectional analytical study to collect data from July 2010 to August 2011 from a tertiary care hospital in Karachi, Pakistan. A sample of 105 women aged between 15-80 years referred for 64-MDCT of abdomen and pelvis with clinical suspicion of malignant ovarian cancer, irrespective of stage of disease, were enrolled by non-probability purposive sampling. All patients who were already known cases of histologically proven ovarian carcinoma and having some contraindication to radiation or iodinated contrast media were excluded. Results: Our prospective study reports sensitivity, specificity; positive and negative predictive values with 95%CI and accuracy were computed. Kappa was calculated to report agreement among the two radiologists. For reader A, MDCT was found to have 92% (0.83, 0.97) sensitivity and 86.7% (0.68, 0.96) specificity, while PPV and NPV were 94.5% (0.86, 0.98) and 86.7% (0.63, 0.92), respectively. Accuracy reported by reader A was 90.5%. For reader B, sensitivity, specificity, PPV and NPV were 94.6% (0.86, 0.98) 90% (0.72, 0.97) 96% (0.88, 0.99) and 87.1% (0.69, 0.95) respectively. Accuracy computed by reader B was 93.3%. Excellent agreement was found between the two radiologists with a significant kappa value of 0.887. Conclusion: Based on our study results, we conclude MDCT is a reliable imaging modality in diagnosis of ovarian masses accurately with insignificant interobserver variability.