• Journal of the korean academy of Pediatric Dentistry
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• v.43 no.4
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• pp.461-466
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• 2016

Dental caries is an important dental disease among children and adolescents that can continue for a lifetime. Early detection of dental caries in deciduous dentition is significant because it can influence the permanent teeth. It is also critical to prevent dental caries by performing fluoride treatment and pit-and-fissure sealant for high-risk children. Various methods have been developed for the early detection of dental caries; however, many studies are still seeking to discover more effective methods. In general, visual examination and radiographic images are used, but these techniques have several limitations such as errors and radiation exposure. In this study, clinical application of the newly developed DIAGNOcam caries identification device and its possible applications were examined. DIAGNOcam was applied to diagnose dental caries in the posterior teeth of patients in the Department of Pediatric Dentistry, and it was confirmed that it could be used to detect proximal caries, the margin of restoration, and the extent of dental caries lesions.

• Journal of the korean academy of Pediatric Dentistry
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• v.42 no.1
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• pp.80-86
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• 2015

Dentists who want to perform sedation must have abilities to control any emergent situation that may occur during treatment procedures. In the 2010 guideline for the use of sedation by dentists, he/she must has valid certifications for basic life support (BLS) and for advanced cardiovascular life support (ACLS). The Korean Association of Cardiopulmonary Resuscitation (KACPR) has made a contract with the American Heart Association for education and certification. From 2004, they have held many courses for BLS and ACLS providers and instructors. The author of this research participated in the above mentioned courses and qualified as a BLS provider, BLS instructor and ACLS provider. The present paper was intended as an introduction to and arrangement of BLS and ACLS courses for health care providers through a year of experience. However, the previous course of the ACLS provider was focused more toward medical doctors. It is necessary to develop a new advanced course for dentists who employ sedation in their medical practices.

• Journal of the korean academy of Pediatric Dentistry
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• v.41 no.2
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• pp.187-192
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• 2014

Research ethics is the basic attitude for researchers. Thanks to our predecessors we are able to conduct systematic studies. The current trend of results and the amount of study-oriented assessments make the side effect that researchers conduct SCI (Science Citation Index) studies. Since the Declaration of Helsinki, the importance of the right, safety and welfare for human participants have improved. In the present study, I looked into other countries' standpoints concerning the subject of the responsibilities for research ethics and compared them with Korean's standpoint. Recently, the Ministry of Health and Welfare revised the laws for bioethics and safety. In the point of bioethics, I checked out the function, exemption and process of the Institutional Review Board for the future researcher. It is suggested to use the research note to verify a study procedure and protect oneself from research misconducts.

• Journal of Hydrogen and New Energy
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• v.28 no.2
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• pp.121-128
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• 2017

For an investigation on the effect of the shape of electrodes in alkaline water electrolysis, two kinds of stack with circular and square electrode array are used to visualize both for behaviors of hydrogen bubble around the electrodes and for measurements of hydrogen production from these two stacks. The electrolytes for the hydrogen production experiment were applied for 20 wt%, 25 wt%, 30 wt% and 35 wt% of KOH alkaline aqueous solutions. As a result, the adhesion length of bubbles attached around the square electrode in the visualization experiment was found to be 1.7 times longer compared with the attached around the circular electrode. In the hydrogen production experiments, the volume of hydrogen production of the stack by using circular electrode array was approximately 3% more than that of the stack with square electrode array. These observations may be caused by the effect of the bubbles attached to the around the electrodes obstructing mass transfer such as hydrogen exhaust and electrolyte supply.

• Journal of the korean academy of Pediatric Dentistry
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• v.43 no.3
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• pp.292-298
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• 2016

The aim of this study was to compare the compressive strength and amount of fluoride-release of recently developed giomers (Beautifil Flow Plus F00, Beautifil Flow Plus F03), conventional giomer, resin-modified glass ionomer and composite resin. Fifteen cylindrical specimens for each group were prepared to measure fluoride release. It was measured using pH/ISE meter and fluoride ion electrode every 24 hours for the first 7 days and every 72 hours until the 31st day. Also, fifteen cylindrical specimens for each group after thermocycling were prepared to measure compressive strength. The universal testing machine (Kyung-sung Testing Machine Co., Korea) was used and the crosshead speed was 1 mm/min. Recently developed giomers showed more fluoride release and higher compressive strength than conventional giomer. It would be a good alternative to composite resin.

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.2
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• pp.242-249
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• 2018

The purpose of this study is to compare the properties of dental pulp and periodontal ligament stem cells from extracted supernumerary teeth by quantitative real-time PCR. Impacted supernumerary teeth in the maxillary anterior region were extracted. Dental pulp and periodontal ligament cells were collected from extracted supernumerary teeth on the same day. After isolation and culture of cells, compare characterization of them by using qRT-PCR. Primer sequences for odontoblasts are ONT, ALP, OCN, DMP-1 and DSPP. On dental pulp group, ONT has the largest quantity of gene expression, followed by OCN, ALP, DMP-1 and DSPP. On periodontal ligament group, ONT has the largest quantity of gene expression, followed by OCN, ALP, DSPP and DMP-1. Analysis of quantitative gene expression data using relative quantification showed that the expression of all genes decreased in periodontal ligament cells. Dental pulp and periodontal ligament stem cells from supernumerary teeth have the properties of odontoblasts. Considering that properties, supernumerary teeth were considered a useful donor site of dental pulp and periodontal ligament stem cells.

• Biomedical Science Letters
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• v.20 no.1
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• pp.43-47
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• 2014

To understand the effect of prenatal stress on sex-specific changes in embryonic and placental growth, a synthetic glucocorticoid (dexamethasone) was administered intraperitoneally at a dosage of 1 mg/kg body weight (BW) (Dex1) or 10 mg/kg BW (Dex10) to pregnant ICR mice at the gestational days 7.5, 8.5 and 9.5 post coitum (p.c.). Embryos and placentas were then harvested at days 11.5 and 18.5 p.c., and their body weight and size were measured following the determination of sex through PCR using Sry specific primers in tail tissues. As a result, female embryos presented reduced fetal body weight and size in Dex1- and Dex10-treated groups than those of control group at the embryonic day 11.5 p.c. Interestingly, the growth seems to be recovered at day 18.5 as there was no difference in growth between control and dexamethasone treated groups. In the case of males, Dex1 induced a decrease in fetal weight in day 11.5 and this pattern was maintained until day 18.5, whereas their growth was not affected by Dex10 treatment. Placental growth showed similar patterns to fetal growth in both sexes but the extent of reduction was not statistically significant in most cases. Placental weights in Dex1- and Dex10-treated group were decreased significantly in male only. The results imply that the effect of prenatal stress is largely sex dependent due to different strategies for growth and survival in a stressful environment.

• Journal of The Korean Astronomical Society
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• v.48 no.5
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• pp.229-236
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• 2015

We report results of investigation of amplitude calibration for very long baseline interferometry (VLBI) observations with Korean VLBI Network (KVN). Amplitude correction factors are estimated based on comparison of KVN observations at 22 GHz correlated by Daejeon hardware correlator and DiFX software correlator in Korea Astronomy and Space Science Institute (KASI) with Very Long Baseline Array (VLBA) observations at 22 GHz by DiFX software correlator in National Radio Astronomy Observatory (NRAO). We used the observations for compact radio sources, 3C 454.3, NRAO 512, OJ 287, BL Lac, 3C 279, 1633+382, and 1510–089, which are almost unresolved for baselines in a range of 350-477 km. Visibility data of the sources obtained with similar baselines at KVN and VLBA are selected, fringe-fitted, calibrated, and compared for their amplitudes. We find that visibility amplitudes of KVN observations should be corrected by factors of 1.10 and 1.35 when correlated by DiFX and Daejeon correlators, respectively. These correction factors are attributed to the combination of two steps of 2-bit quantization in KVN observing systems and characteristics of Daejeon correlator.

• Journal of Hydrogen and New Energy
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• v.28 no.3
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• pp.238-245
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• 2017

Mg-Ni nanoparticles were synthesized by a physical vapor condensation method (DC arc-discharge) in a mixture of argon and hydrogen atmosphere, using compressed mixture of micro powders as the raw materials. The crystal phases, morphology, and microstructures of nanoparticles were analyzed by means of X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM). It was found that the intermetallic compounds of $Mg_2Ni$ and $Mg_2Ni$ formed with existence of phases of Mg, Ni, and MgO in Mg-Ni nanoparticles. After one cycle of hydrogen absorption/desorption process (activation treatment), Mg-Ni nanoparticles exhibited excellent hydrogen absorption properties. $Mg_2Ni$ phase became the main phase by aphase transformation during the hydrogen treatments. The phenomenon of refinement of grain size in the nanoparticle was also observed after the hydrogen absorption/desorption processes, which was attributed to the effect of volume expansion/shrinkage and subsequent break of nanoparticles. Maximum hydrogen absorption contents are 1.75, 2.21 and 2.77 wt.% at 523, 573 and 623 K, respectively.

• Journal of the korean academy of Pediatric Dentistry
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• v.41 no.3
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• pp.272-276
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• 2014

Recording of the research procedure and results is the compulsory virtue to scientists. This ensures the objectivity and integrity of research and has become a cornerstone for a junior scholar. Furthermore, we can save time and efforts by avoiding duplication study. Recently on its patent application, the value of laboratory notebook is going to increase. However, there is a limitation to record a voluminous work in a traditional writing laboratory notebook. So, it could be an alternative proposal to convert that into an electronic work or develop an electronic laboratory notebook. Our journal has continuously pursued globalization. Laboratory notebook could be one of the key factors for that goal. In the present study, the authors reviewed the needs for laboratory notebook and tried developing a proto-type electronic laboratory notebook.