• Asian Pacific Journal of Cancer Prevention
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• 제14권3호
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• pp.1755-1760
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• 2013

Objective: To investigate the prevalence of genital high-risk human papillomavirus (HR-HPV) in male sexual partners of HR-HPV infected women and the concordance of viral types in couples in China, and comprehend the role of men play in HPV transmission to women. Methods/Materials: 94 asymptomatic women and their husbands from rural Chaozhou participated in epidemiologic screening for HPV infection. Cervical cells from females were collected for high risk HPV screening by real time-PCR, and they were positive for at least 1 of 13 HR-HPV subtypes, then these samples were genotyped. Approximately one mouth later, penile epithelial cells from 94 asymptomatic husbands were collected for HPV genotyping. At the same time, a cross-sectional study was conducted in 366 male patients from sexually transmitted disease (STD) outpatient clinic in China for the prevalence of genital HR-HPV infection in men having frequent sex behavior. Penial epithelial cells were collected for HPV 6/11 and HPV 16/18 detection by fluorescent real-time quantified PCR. Results: Among 94 couples, the prevalence of genital HR-HPV infection in men whose wife was positive for cervical HR-HPV was 5.32% (5/94). Only 2.63% (2/76) had the same high risk viral type presented by their wife. HPV 16 proved to be the most prevalent viral type in men and in couples. Of 366 male patients from STD outpatient clinic, the prevalence of HPV 16/18 infection in men with or without HPV 6/11 was 6.85% and 8.16%, respectively. The incidence of HPV 16/18 was higher in men aged more than 35 years than the young men (18-35 years). Conclusion: The prevalence of genital HR-HPV infection in male sexual partners of HPV-positive women in China was lower than that expected, and the concordance of high risk viral type between couples was extremely low. These data suggested that infected men consitute an important viral reservoir, contributing to transmission of HR-HPV to women and maintenance of infection, but HR-HPV infection may be less likely to persist in men than in women.

• Journal of the Korean Magnetics Society
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• 제21권1호
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• pp.23-31
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• 2011

From among the NDT (nondestructive testing) methods, the MFL (magnetic flux leakage) method is specially suitable for testing pipelines because pipeline has high magnetic permeability. The system applied to MFL method is called the MFL PIG. The previous MFL PIG showed high performance in detecting the metal loss and corrosions. However, MFL PIG is highly unlikely to detect the cracks which occur by exterior-interior pressure difference in pipelines and the shape of crack is long and very narrow. In MFL PIG, the magnetic field is performed axially and there is no changes of cross-sectional area at cracks that the magnetic field passes through. Cracks occur frequently in the pipelines and the risk of the accident from the cracks is higher than that from the metal loss and corrosions. Therefore, the new PIG is needed to be researched and developed for detecting the cracks. The circumferential MFL (CMFL) PIG performs magnetic fields circumferentially and can maximize the magnetic flux leakage at the cracks. In this paper, CMFL PIG is designed and the distribution of the magnetic fields is analyzed by using 3 dimensional nonlinear finite element method (FEM). In CMFL PIG, cracks, standards of NACE, are detectable. To estimate the shape of crack, the leakage of magnetic fields for many kinds of cracks is analyzed and the method is developed by signal processing.

• Journal of dental hygiene science
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• 제16권4호
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• pp.257-262
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• 2016

The purpose of this study was to assess the correlation between integrated mineral loss (volume % mineral${\times}{\mu}m$, ${\Delta}Z_{TMR}$) determined using transverse microradiography (TMR) and integrated reflectivity ($dB{\times}{\mu}m$, ${\Delta}R_{OCT}$) determined using optical coherence tomography (OCT) for detecting early dental caries with lesion depth more than $200{\mu}m$. Sixty tooth specimens were made from sound bovine teeth. They were immersed in a demineralized solution for 20, 30, and 40 days. The ${\Delta}R_{OCT}$ was obtained from the cross-sectional OCT image. The ${\Delta}Z_{TMR}$ was obtained from the TMR image. The correlation between ${\Delta}R_{OCT}$ and ${\Delta}Z_{TMR}$ was examined using Pearson correlation. The Bland-Altman plot was constructed using the ${\Delta}R_{OCT}$ and ${\Delta}Z_{TMR}$ values. A significant correlation between ${\Delta}R_{OCT}$ and ${\Delta}Z_{TMR}$ was confirmed (r=0.491, p=0.003). Moreover, most of the difference between ${\Delta}R_{OCT}$ and ${\Delta}Z_{TMR}$ was included in the error section of the Bland-Altman plot. Therefore, OCT could be used as a substitute for TMR when analyzing mineral loss in early dental caries.

• The Journal of Advanced Prosthodontics
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• 제5권4호
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• pp.402-408
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• 2013

PURPOSE. The aim of this study was to evaluate the surface properties and in vitro bioactivity to osteoblasts of magnesium and magnesium-hydroxyapatite coated titanium. MATERIALS AND METHODS. Themagnesium (Mg) and magnesium-hydroxyapatite (Mg-HA) coatings on titanium (Ti) substrates were prepared by radio frequency (RF) and direct current (DC) magnetron sputtering.The samples were divided into non-coated smooth Ti (Ti-S group), Mg coatinggroup (Ti-Mg group), and Mg-HA coating group (Ti-MgHA group).The surface properties were evaluated using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The surface roughness was evaluated by atomic force microscopy (AFM). Cell adhesion, cell proliferation and alkaline phosphatase (ALP) activity were evaluated using MC3T3-E1 cells. Reverse transcription polymerase chain reaction (RT-PCR) analysis was performed. RESULTS. Cross-sectional SEM images showed that Mg and Mg-HA depositionson titanium substrates were performed successfully. The surface roughness appeared to be similaramong the three groups. Ti-MgHA and Ti-Mg group had improved cellular responses with regard to the proliferation, alkaline phosphatase (ALP) activity, and bone-associated markers, such as bone sialoprotein (BSP) and osteocalcin (OCN) mRNA compared to those of Ti-S group. However, the differences between Ti-Mg group and Ti-MgHA group were not significant, in spite of the tendency of higher proliferation, ALP activity and BSP expression in Ti-MgHA group. CONCLUSION. Mg and Mg-HAcoatings could stimulate the differentiation into osteoblastic MC3T3-E1 cells, potentially contributing to rapid osseointegration.

• Journal of Dental Rehabilitation and Applied Science
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• 제22권2호
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• pp.173-180
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• 2006

Objectives The aim of this study is to compare the quality of root canal preparation completed using MFile-$System^{(R)}$ instrument ( Komet, Gebr.Brsaseler, Germany) and conventional stainless steel file in the canals of Maxillary molar teeth that had a canal curvature between $25^{\circ}$ or more Materials & Methods Buccal canals of 24 first and second maxillary molar teeth, extracted for periodontal and prosthetic reasons were used. Tissue fragments and calcified debris were removed from teeth by scaling and the teeth were stored in 10% formalin solution for 24 hour. Then, teeth were stored in saline until used. To be included the roots had to have completed formed apices and angle of curvature ranging between $25^{\circ}$ or more according to the criteria described by Schneider(1971). Palatal and Second mesiobuccal canals were not included. Teeth were embedded into transparent acrylic. The teeth were randomly divided into two experimental groups. All teeth were scanned by Dental CT (PSR9000N, Asahi, Japan) to determine the root canal shape before instrumentation. Image slices were prepared from the apical end point to the pulp chamber. The first two sections were 2 mm from the apical end of root and 2 mm below the orifice. Further section was recorded, dividing the distance between the sections of apical and coronal levels into two equal lengths. 12 teeth were instrumented using stainless steel fileand another 12 teeth were instrumented using MFile-$System^{(R)}$. Following the completion of the instrumentation, the teeth were again scanned and compared with the cross sectional images taken prior to canal preparation. Amount of transportation and centering ability was assessed. Student's t-test was used for statistical analysis. Result Less transportation occurred with MFile-$System^{(R)}$ rotary instrumentation than stainless steel instrument. MFile-$System^{(R)}$ had better centering ability than stainless steel instrument. Conclusion MFile-$System^{(R)}$ rotary instrumentation transported canals less and had good centering ability.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제17권1호
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• pp.3-9
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• 2006

Objectives: Obesity is one of risk factors for psychological and social adjustment problems (depression, low self esteem, low school function etc). Quality of life(QOL) is comprehensive and multidimensional construct including physical, emotional, social and school functioning. Some authors reported that child and adolescent obesity is associated with impaired QOL. This study was to examine the association between QOL and body mass index (BMI) in middle school students. Methods : Cross sectional analysis of 471 adolescents between the ages of 13 and 14 years ($mean{\pm}SD,\;13.4{\pm}0.6$), who attended one of middle schools in Seoul, Korea. Participants' QOL were scored by using Korean version of pediatric QOL inventory generic score scale ($PedsQL^{TM}$ 4.0). Participants had a $mean{\pm}SD\;BMI\;of\;21.3{\pm}4.0$. Self reports and parent proxy reports using $PedsQL^{TM}$ 4.0 were administered to measure participant's QOL. Participants were divided into four groups by BMI (Male: obesity group >26.5, at risk group 23.2-26.5, normal weight group 15.8-23.1, underweight group <15.8, Female : obesity group >25.2, at risk group 22.9-25.2, normal weight group 16.0-22.8, underweight group <16.0). Results : Compared with other groups, obese adolescents reported significantly(p<0.01) love. QOL in all domains. Obese adolescents were more likely to have impaired QOL than normal weight adolescents (Odds Ratio, 8.3, 95% confidence interval, 4.0-16.7). Conclusion : Obese adolescents have lower QOL than normal weight adolescents. Psychiatrist, parents, and teachers need to be informed of the risk fur impaired QOL in obese adolescents to target interventions that could enhance health outcomes.

• Journal of Navigation and Port Research
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• 제44권4호
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• pp.305-311
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• 2020

Rising sea levels along the coast from global warming causes the increase of wave energy along the coast. This rise in sea levels results in relatively deep water levels, which would incur the loss of sand that had not occurred in the past from erosion in coastal areas. Generally, it has been challenging to protect against coastal erosion, and the slope, cross-sectional shape, and materials are selected for the site conditions depending on the change in external forces. However, the application of counter measures based on insufficient understanding of the phenomenon is causing various damage, indicating the need for technological development and converging technologies to improve credibility. In this study, we developed eco-friendly permeable biopolymer concrete blocks to control the coastal erosion by using the Bio-Coast, an effective porous structure that mitigates the destructive erosion caused by the rising sea levels. The hexagonal design of Bio-Coast was derived from the honeycomb, columnar joints, and clover, which are durable and stable structures in nature, and the design was changed to apply bumps on the Bio-Coast filling in the form of a clover to reduce wave overtopping and run-up. Applying the field condition of beaches on the east coast of Korea, the block weight and size were decided and the prototype blocks were manufactured and are ready for field placement. In particular, it is intended to protect coastal areas from destructive erosion by natural and artificial external forces, and to extend the design to river,s lakes, and natural walking trails, to improve the efficiency of quality control and process control through the use of blocks.

• Journal of the Korea Concrete Institute
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• 제28권3호
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• pp.365-373
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• 2016

Ultra-High-Performance Steel Fiber-Reinforced Concrete (SUPER Concrete) exhibits improved compressive and tensile strengths far superior to those of conventional concrete. These characteristics can significantly reduce the cross sectional area of the member and the anchorage strength of a headed bar is expected to be improved. In this study, the anchorage strengths of headed bars with $4d_b$ or $6d_b$ embedment length were evaluated by simulated exterior beam-column joint tests where the headed bars were used as beam bars and the joints were cast of 120 or 180 MPa SUPER Concrete. In all specimens, the actual yield strengths of the headed bars over 600 MPa were developed. Some headed bars were fractured due to the high anchorage capacity in SUPER Concrete. Therefore, the headed bar with only $4d_b$ embedment length in 120 MPa SUPER Concrete can develop a yield strength of 600 MPa which is the highest design yield strength permitted by the KCI design code. The previous model derived from tests with normal concrete and the current design code underestimate the anchorage capacity of the headed bar anchored in SUPER Concrete. Because the previous model and the current design code do not consider the effects of the high tensile strength of SUPER Concrete. From a regression analysis assuming that the anchorage strength is proportional to $(f_{ck})^{\alpha}$, the model for predicting anchorage strength of headed bars in SUPER Concrete is developed. The average and coefficient of variation of the test-to-prediction values are 1.01 and 5%, respectively.

• Information Systems Review
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• 제15권1호
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• pp.105-122
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• 2013

Given the proliferation of social network services, it has become important to understand its user's continued use behavior. As users' privacy concerns in SNS have been identified as a critical barrier against forming this continued intention, many studies have focused on inducing continued intention by mitigating privacy concerns. However, this paper suggests to approach users' continued intention not only from the perspective of mitigating privacy concerns but also from the perspective of increasing potential benefits. Under the theoretical framework of privacy calculus model, we conducted cross sectional survey on 150 Facebook and 150 KakaoTalk users. The result suggests that trust mediates the relationships between privacy concerns and continued intention and between network externality and continued intention, and the influence of support for network formation on continued intention. The effect of network externality on continued intention, however, is not significant among Facebook users while it is significant among KakaoTalk users.

• Composites Research
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• 제30권3호
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• pp.175-180
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• 2017

Currently, since carbon fiber reinforced plastics (CFRPs) are lightweight and have excellent physical properties, their demand has increased dramatically. Many works have studied the CFRPs based on recycled thermoplastics. In this study, the applicability of recycled composite was evaluated using recycled polyethylene terephthalate (PET). PET was collected from waste materials used in beverage bottles and processed to produce PET films. Optimal thermoforming temperature and time were analyzed by comparing the mechanical properties with forming temperature and time difference for producing PET films. CF mat and PET film were used to determine the suitable parameters for the optimum thermoforming of CF/PET composites. The mechanical properties of each thermoforming condition were verified by bending test. The degree of impregnation of the PET film into the CF mat was evaluated by cross-sectional photographs, whereas the interfacial properties were evaluated by interlaminar shear strength (ILSS). Ultimately, it was confirmed that the thermoforming condition for forming the CF/recycled PET composites yielding the optimal mechanical and interfacial properties was at $270^{\circ}C$ for 5 minutes.