• The Journal of the Korean dental association
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• v.55 no.6
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• pp.413-422
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• 2017

Purpose: The aim of this study was to confirm the validity of the $Cariview^{TM}$, test in adults by assessing correlations between $Cariview^{TM}$, scores and caries experience using a quantitative light-induced fluorescence (QLF) technique. Methods: This retrospective cross-sectional study included 111 patients aged 19-64 years who visited a dental clinic in Seoul from 2015 to 2016, and underwent the $Cariview^{TM}$, test and had their teeth photographed with the Qraycam. Plaque was scraped with sterilized cotton swabs, and then placed in a culture medium and incubated at $37^{\circ}C$ for 48 h. Finally, the degree of color change was evaluated, and scored on a 0-100 point scale. Caries experience index included not only cavitated lesions but also early caries that were detected on white and fluorescence images. Participants were divided into low, moderate and high caries risk groups according to the $Cariview^{TM}$, score, and caries experience was compared between risk groups using ANCOVA. Spearman correlation coefficients were calculated to analyze the associations between $Cariview^{TM}$, scores and caries indices. Result: The mean age of the participants was 40 years, and the mean $Cariview^{TM}$, score was $53.6{\pm}20.7$. The WDMFT and the DMFT indices significantly increased with caries risk, and this increase was significantly different between the low- and high-risk groups. The $Cariview^{TM}$, test scores were significantly correlated with the WDMFT (r = 0.28, P = 0.003) and DMFT (r = 0.29, P = 0.002) indices. Conclusion: The $Cariview^{TM}$, test could be a clinically useful and simple method for assessing caries risk in adults.

• Journal of the Economic Geographical Society of Korea
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• v.15 no.2
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• pp.332-342
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• 2012

The current research aims at classifying the bus stops as transfer center in order to establish the rational bus transfer systems. Existing research typically identifies characteristics of demands for bus stops and land use surrounding the bus stops and classifies and profiles the bus stops. A common problem with this type of research is that the results with cross-sectional characteristics of land use and bus stop usage do not capture the details of trip chain, the fundamental characteristics of the trips with transfer. This paper therefore examines bus stop classifications with such variables as transport mode chains, intermediate stop chains and timing chains. The analysis on the data collected on Monday 20 April 2009 for passengers of Gyeong-gi bus results in a clear classification among bus stops in terms of such trip chain variables. The research would provide useful information for the decision support of transfer stops location choice and infrastructure design.

• Research in Community and Public Health Nursing
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• v.17 no.4
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• pp.441-450
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• 2006

Purpose: The purposes of this study were to identify variables related to self-care behavior and to find factors related to the control of hypertension. A cross-sectional study was carried out to provide basic data for effective and continuous hypertension control in the low-income elderly. Methods: This study was performed with a total of 189 subjects who were hypertensive and were receiving pharmacological treatment of hypertension from a community health center in D Metropolitan City. Data were collected through a face to face survey, and systolic and diastolic blood pressure (the mean value of the two measures) were measured during May 2004. Obtained data were analyzed by $x^2$ test, t-test, multiple logistic regression and Pearson's correlation coefficient (using SPSS Version 10.1). Results: 1. According to demographical characteristics, the score of self-care behavior was significantly higher in elders living along ($47.63{\pm}7.276$) than in those living with the family ($45.19{\pm}5.501$) (p<.05), and in those with religion ($47.11{\pm}6.722$) than in those without religion ($45.01{\pm}6.110$) (p<.05) 2. As to blood pressure control, the percentage of blood pressure control within the normal range (systolic 140mmHg, diastolic below 90mmHg) was 37.03%. According to demographical characteristics, the percentage of blood pressure control was significantly lower in those without religion (p<.05). In practicing hypertension self-care behavior, those who do not control salk intake showed a significantly lower percentage of hypertension control (p<.05). The score of hypertension self-care was $48.28{\pm}4.443$ in the controlled group, and $45.42{\pm}7.399$ in the uncontrolled group, showing a significant difference (p<.01). 3. Hypertension self-care behavior was in a positive correlation with blood pressure control (r=.210, p<.05). Conclusion: Attention should be paid to self-care behavior to increase the control of hypertension in the low-income elderly. These results can be used guidances for improving self-care behavior and the control of hypertension in the low-income elderly.

• Korean Journal of Materials Research
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• v.23 no.3
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• pp.155-160
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• 2013

ZnO thin films co-doped with Mg and Ga (MxGyZzO, x + y + z = 1, x = 0.05, y = 0.02 and z = 0.93) were prepared on glass substrates by RF magnetron sputtering with different sputtering powers ranging from 100W to 200W at a substrate temperature of $350^{\circ}C$. The effects of the sputtering power on the structural, morphological, electrical, and optical properties of MGZO thin films were investigated. The X-ray diffraction patterns showed that all the MGZO thin films were grown as a hexagonal wurtzite phase with the preferred orientation on the c-axis without secondary phases such as MgO, $Ga_2O_3$, or $ZnGa_2O_4$. The intensity of the diffraction peak from the (0002) plane of the MGZO thin films was enhanced as the sputtering power increased. The (0002) peak positions of the MGZO thin films was shifted toward, a high diffraction angle as the sputtering power increased. Cross-sectional field emission scanning electron microscopy images of the MGZO thin films showed that all of these films had a columnar structure and their thickness increased with an increase in the sputtering power. MGZO thin film deposited at the sputtering power of 200W showed the best electrical characteristics in terms of the carrier concentration ($4.71{\times}10^{20}cm^{-3}$), charge carrier mobility ($10.2cm^2V^{-1}s^{-1}$) and a minimum resistivity ($1.3{\times}10^{-3}{\Omega}cm$). A UV-visible spectroscopy assessment showed that the MGZO thin films had high transmittance of more than 80 % in the visible region and that the absorption edges of MGZO thin films were very sharp and shifted toward the higher wavelength side, from 270 nm to 340 nm, with an increase in the sputtering power. The band-gap energy of MGZO thin films was widened from 3.74 eV to 3.92 eV with the change in the sputtering power.

• Korean Journal of Optics and Photonics
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• v.3 no.4
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• pp.258-265
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• 1992

A low loss optical waveguide of $P_{2}O_{5}-SiO_{2}$on Si substrate is produced by using the chemical vapour deposition method of $SiO_2$ thin films used in Si technology. Propagation loss of the waveguide layer was 1.65 dB/cm as produced and reduced down to 0.1 dB/cm after heat treatment at $1100^{\circ}C$. By using laser lithography and reactive ion etching method $P_{2}O_{5}-SiO_{2}$ waveguide was produced and subsequently annealed at $1100^{\circ}C$.As a result of this annealing the shape of the waveguide core was changed from rectangular to semi-circular form, and the propagation loss was reduced as down to 0.03 dB/cm at 0.6328$\mu$m and 0.04dB/cm at 1.53$\mu$m. We think that the mechanism of the reduction in propagation loss during the heat treatment is the following: 1) The hydrogen bonding in waveguide layer, which causes absorption loss, is dissociated and diffused out. 2) The roughness of the interface and the micro-structure of the waveguide layer is removed. 3) The irregularities in the cross-sectional shape of the waveguide which was induced during the lithographic process were disappeared by flowing of the waveguide core.

• Korean Journal of Optics and Photonics
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• v.30 no.6
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• pp.243-248
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• 2019

The respiratory tract is an essential part of the respiratory system involved in the process of respiration. However, if stenosis occurs, it interferes with breathing and can even lead to death. Asthma is a typical example of a reversible cause of airway narrowing, and the number of patients suffering from acute exacerbation is steadily increasing. Therefore, it is important to detect airway narrowing early and prevent the patient's condition from worsening. Optical coherence tomography (OCT), which has high resolution, is suitable for observing the microstructure of tissues. In this study we developed an endoscopic OCT system. We combined a 1300-nm OCT system with a servo motor, which can rotate at a high speed. A catheter was pulled back using a linear stage while imaging with 360° rotation by the motor. The motor was selected considering various requirements, such as torque, rotational speed, and gear ratio of pulleys. An ex vivo rabbit tracheal model was used as a sample, and the sample and catheter were immobilized by acrylic structures. The OCT images provided information about the structures of the mucosa and submucosa. The difference between normal and stenosed parts in the trachea was confirmed by OCT. Furthermore, through a three-dimensional (3-D) reconstruction process, it was possible to identify and diagnose the stenosis in the 3-D image of the airway, as well as the cross-sectional image. This study would be useful not only for diagnosing airway stenosis, but also for realizing 3-D imaging.

• Journal of The Korean Society of Clinical Toxicology
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• v.11 no.2
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• pp.96-100
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• 2013

Purpose: The purpose of this study was to examine the research characteristics and the trend of the Journal of the Korean Society of Clinical Toxicology by bibliometric analysis. Methods: This study was a retrospective quantitative literature review of the publications. We collected data from the internet homepage of the Korean Society of Clinical Toxicology. Among 228 publications, a total of 225 articles were included in this analysis. The data were analyzed from different perspectives, including article types, study design, number of authors, type of toxic material, and the top five ranking prolific authors and the affiliated organization were identified. Results: A total of 225 articles were analyzed; 98(43.6%) were original articles, 115(51.1%) were case reports, and 12(5.3%) were reviews. Among the original articles, nine were prospective studies and 89 were retrospective studies, which were assorted according to study design; there were two(2.0%) cross sectional studies, 93(94.9%) cohort studies, and three(3.1%) etc. The median number of authors per article was five and the top five ranking authors and affiliated organizations published 31.1% and 32.8% of total articles, respectively. The most abundant topic was pesticides, followed by natural poisons and poisons encountered in the work place. Conclusion: Since its foundation, the Journal of the Korean Society of Clinical Toxicology has published 19 issues and 228 articles and has played a key role in development of toxicology research in Korea. However, low ratio of original articles and a decrease in the number of recent articles indicates that greater effort is needed in clinical research. In addition, further interest of many experts and various institutions is necessary.

• Journal of Veterinary Clinics
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• v.26 no.6
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• pp.524-527
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• 2009

Spontaneously infected and non-infected dairy cows were assessed in a cross-sectional study aimed at determining whether bovine leukocyte markers may diagnose intra-mammary infections (bovine mastitis). Animals located in herds where bovine mastitis was highly prevalent were investigated (n = 31 animals). The expression of three cell-surface markers (CD11b, CD4 and CD8) was assessed, and the somatic cell count (SCC) and bacteriological analyses (both cultures and PCR tests) were also conducted. Cows identified as infected revealed statistically significant higher milk leukocyte CD11b, CD4 percentage and milk CD4/CD8 ratios than non-infected cows. Immunological markers may diagnose spontaneous bovine mastitis.

• Membrane Journal
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• v.12 no.2
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• pp.75-89
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• 2002

The effect of addition of inorganic salts in polyethersulfone (PES) polymer solution on the membrane formation and ultrafiltartion performance was studied through the thermodynamic and kinetic properties of casting solution. To control the thermodynamic and kinetic properties of casting solution, various inorganic salts $[CaC1_2, LiCl, LiClO_4, ZnC1_2 $and Mg(ClO_4)_2]$ were added in the PES/NMP solution. Variation of membrane morphology and performance of the resulting membranes with change of the salt type and content added in tasting solution were discussed using viscosity, coagulation value, light transmittance measurement, overall membrane porosity, ultrafiltration experiment and cross-sectional SEM image. For all kind of inorganic salts, according as increase of the salt content in casting solution, viscosity is increased, coagulation value becomes lower, top layer thickness below the skin surface is increased, bovine serum albumin(BSA) rejection decreased and pure water flux is increased except $CaC1_2$ and LiCl. In case of $CaC1_2$ and LiCl, it is found that when the salt content is increased, the formation of macrovoids is suppressed and the precipitation rate becomes slow while instantaneous demixing of precipitation type is maintained. However, in case of $LiClO_4$ and $Mg(ClO_4)_2,$ it is found that precipitation rate becomes faster.

• Safety and Health at Work
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• v.11 no.1
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• pp.33-40
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• 2020

Background: Exploratory study to investigate whether co-exposure to physical wrist stressors and chemicals is associated with carpal tunnel syndrome (CTS) in French male farmers and agricultural workers. Methods: Cross-sectional study of 711 men aged 30-65 years and working as either farmers or agricultural workers in 2009-2010 within a cohort covered by the French Agricultural Workers' and Farmers' Mutual Benefit Fund. CTS and exposure to physical wrist stressors and chemicals were assessed using a self-administered questionnaire. Associations between CTS and personal/medical factors, exposure to physical wrist stressors, exposure to chemicals, and co-exposure to physical wrist stressors and chemicals were studied using multivariate logistic regression models. Results: Forty-four men {5.6% [95% confidence interval (CI) 4.0-7.7]} reported that they had suffered from unilateral/bilateral CTS during the last 12 months. CTS was associated with age, current smoking [odds ratio (OR) = 2.1 (1.0-4.5)], and exposure to physical wrist stressors [OR = 2.6 (1.1-5.9)]. An association was found between CTS and co-exposure to physical wrist stressors and chemicals [OR = 3.3 (0.8-14.3), p = 0.044] in comparison with the no-exposure group. Conclusions: This exploratory study shows an association of CTS with exposure to biomechanical wrist stressors in male farmers and agricultural workers and suggests an association of CTS with co-exposure to physical wrist stressors and chemicals. Owing to the limitations of the study, this result must be confirmed by a prospective study with objective assessments of the outcome and exposure before drawing conclusions on the possible synergistic effects of mechanical stressors and chemicals on the impairment of the median nerve.