• Journal of Korean society of Dental Hygiene
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• v.20 no.5
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• pp.675-684
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• 2020

Objectives: This study examined the professionalism, major satisfaction, self-leadership, and career preparation behavior of dental hygiene students, and examined the factors affecting career preparation behavior. Methods: A self-administered questionnaire survey was conducted among dental hygiene students in the Seoul and Gyeonggi areas of Korea, and finally, questionnaires submitted by 190 subjects were analyzed. Statistical analysis was conducted using SPSS 21.0. Results: The average scores for professionalism, major satisfaction, self-leadership, and career preparation behavior among the evaluated subjects were 3.68±0.56, 3.44±0.46, 3.57±0.55, and 3.24±0.52, respectively. Students who answered that their motivation for career preparation according to general characteristics was "because it is a valuable job" showed the highest score of 3.60±0.54 for professionalism (p<0.01) and higher scores for major satisfaction and career preparation behavior (p<0.001). The factors that affected career preparation behavior were self-leadership (p<0.001), major satisfaction (p<0.01), and professional intuition (p<0.01). Conclusions: The study findings showed that groups with higher self-leadership, major satisfaction, and professionalism exhibited more active career preparation behavior. Therefore, various educational programs are needed to improve dental hygiene (academics) and career preparation behavior of students.

• Restorative Dentistry and Endodontics
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• v.19 no.1
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• pp.73-84
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• 1994

Using a model system that can compare the before and after of canal preparation in the same tooth, we measured the area of the cross section, and canal wall thickness of the distal portion of the mesial root of the mandibular molar, and compared the amount of reduction in the canal using hand flared preparation the Gates-Glidden drill flared preparation according to the changes in the MAF. The results were as follows. 1. After canal preparation, the canal wall thickness had no significant difference between the hand flared preparation and Gates-Glidden drill flared preparation. 2. The canal wall thickness, after canal preparation, there was no significant difference between the sizes of the MAF. 3. The area variation range of each cross section of root had no significant difference between MAF size and methods of canal preparation. 4. After canal preparation, the frequency of the canal wall thickness under 0.5mm showed 3.5mm below the furcation to be the most frequent with statistical significance(p<0.05). 2mm below the furcation and 5mm below the furcation followed but there was no statistical significance. 5. The danger zone of the mesial root of the mandibular molar seems to be around 3.5mm.

• Elastomers and Composites
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• v.45 no.2
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• pp.80-86
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• 2010

Carbon nanotubes (CNTs) exhibit excellent mechanical, electrical, and magnetic properties as well as nanometer scale diameter and high aspect ratio, which make them an ideal reinforcing agent for high strength polymer composites. The functionalized CNTs are believed to be very promising in the fields such as preparation of functional and composite materials. CNT-Polymer composites are expected to have good processability characteristics of the polymer and excellent functional properties of the CNTs. However, since CNTs usually form stabilized bundles due to Van der Waals interactions, are extremely difficult to disperse and align in a polymer matrix. The biggest issues in the preparation of CNT-reinforced composites reside in efficient dispersion of CNTs into a polymer matrix, and the alignment and control of the CNTs in the matrix. There are several methods for the dispersion of nanotubes in the polymer matrix such as solution mixing, bulk mixing, melt mixing, in-situ polymerization and chemical functionalization of the carbon nanotubes, etc. These methods and preparation of high performance CNT-polymer composites are described in this review.

• Food Science and Biotechnology
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• v.18 no.2
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• pp.565-569
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• 2009

This study was conducted to evaluate the effects of different preparation methods on the recovery and quantification of ginsenosides in raw Korean ginseng (Panax ginseng C.A. Meyer). Eight major ginsenosides ($Rb_1$, $Rb_2$, $Rb_3$, Rc, Rd, Re, Rf, and $Rg_1$) were analyzed by high performance liquid chromatography (HPLC), after which the recovery and repeatability of the extraction of those ginsenosides using 3 different preparation methods were compared [A. direct extraction (DE) method, hot MeOH extraction/evaporation/direct dissolution; B. solid phase extraction (SPE) method, hot MeOH extraction/evaporation/dissolution/$C_{18}$ cartridge adsorption/MeOH elution; C. liquid-liquid extraction (LLE) method, hot MeOH extraction/evaporation/dissolution/n-BuOH fractionation]. Use of the DE method resulted in a significantly higher recovery of total ginsenosides than other methods and a relatively clear peak resolution. Use of the SPE and LLE methods resulted in clearer peak resolution, but lower ginsenoside recovery than the DE method. The LLE method showed the lowest ginsenoside recovery and repeatability among the 3 methods. Given that the DE method employed only extraction, evaporation, and a dissolution step (avoiding complicate and time consuming purification), this technique may be an effective method for the preparation and quantification of ginsenosides from raw Korean ginseng.

• Elastomers and Composites
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• v.50 no.1
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• pp.35-48
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• 2015

Polyhedral oligomeric silsesquioxane (POSS) is an important inorganic-organic hybrid material with a three-dimensional structure. Polyurethane (PU) is a widely applied polymer that has versatile properties with the change of two phase structure. When POSS is incorporated into PU by physical or chemical methods, many properties can be greatly improved, such as mechanical properties, thermal stability, biodegradation resistance, and water resistance. This paper reviews the recent progress in preparation, structure, and performance of POSS-modified polyurethane from the viewpoint of physical blending and chemical modification.

• Journal of Technologic Dentistry
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• v.37 no.3
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• pp.145-155
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• 2015

Purpose: The Purpose of the study is to investigate the need for the preparation of old age of Korean dental technicians. Methods: A total of 778 dental technicians were selected by proportional stratified by region compared to extraction sampling from a list of Korea dental technician Association in 2012. The final sample size was 386. Questionnaires consisted of 9 general characteristics, recognition of old age 4, and preparation of old age 9 on a Liken 5 scale. Cronbach's alpha was 0.784 in the study. All statistical analyzed were performed using SPSS 14.0(Statistical Packages for Social Science Ver. 14.0. Chicago, IL, USA). Results: Factors affecting the aging preparation is gender, age, clinical career, work place(p<0.001). Conclusion: This study suggested that preparation for old age of Korean dental technicians was very important and the preparation must be connected with the social welfare policy.

• The Journal of the Korean dental association
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• v.57 no.7
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• pp.380-391
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• 2019

In recent years, with the introduction of various restorative materials, restorations using CAD/CAM equipment have been increasing in the esthetic dentistry. The critical steps in the fabrication of indirect restorations with CAD/CAM equipment are proper cavity preparation and making accurate impressions. The process of tooth preparation for CAD/CAM restoration should include a mechanical understanding of milling. In addition, during tooth preparation, the clinician should be familiar with additional equipment and techniques for obtaining the convenience. In order to obtain an accurate oral scan, the clinician should understand the limitations of the oral scan and be skilled at techniques for obtaining a successful image when making oral scans. This article focused clinical guidelines for the preparation of CAD/CAM restorations and introduced clinical methods for making successful impression of oral scans in narrow and deep tooth cavity areas.

• The Journal of Pediatrics of Korean Medicine
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• v.25 no.2
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• pp.102-110
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• 2011

Objectives: The purpose of this study is to analyze the baby bath preparation and provide necessary information on the upcoming herbal bath preparation for atopic dermatitis. Methods: We selected 113 baby bath preparation by searching typing in "baby bath preparation" in 6 major web-search-engines, and 17 web shopping malls in Korea. 11 items were evaluated under three criteria : type of product, function and ingredient of goods. Results: Result showed that the most common type of bath preparation were liquid type. 96% of the products contained medical agents. Ingredients of the medical agents were herbal medicine, aroma oil, spring and sea ingredients, vitamin and extract. 33% of the products were bath preparation for the atopic dermatitis and 74% of the products were only for the baby. Conclusions: It is necessary to make a government level guideline for natural materials used in bath preparation, and to develop new products contained herbal medicine abide by oriental medical theory.

• The Journal of Korean Medical History
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• v.28 no.1
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• pp.81-92
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• 2015

Objectives : The purpose of this study is to analyze and identify the problems of current laws and regulations regarding preparation and processing of herbal medicines at hospitals of Korean Medicine. Possible solutions are proposed in the end Methods : Based on the status of hospitals of Korean Medicine and characteristics of Korean Medicine and Korean Medicine industry, I analyze the laws and regulations in regards to preparation and processing of herbal medicines and propose possible solutions. Results : Regulations for the agents, places, and cautions in respect of preparation and processing of herbal medicines are inadequate. Meanwhile, the definition of drug preparation in the Pharmaceutical Affairs Act does not apply to processing and preparation of herbal Medicines at hospitals of Korean Medicine, since herbal medicines accompanies chemical and physical change. Discussions & Conclusions : New regulations for on-site preparation at hospitals of Korean Medicine are necessary. Also, the definition for herbal medicines preparation, which states possible chemical and physical changes of herbal medicines, should be specified in Pharmaceutical Affairs Act.

• The Journal of Korean Academic Society of Nursing Education
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• v.25 no.1
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• pp.93-102
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• 2019

Purpose: This study aimed to investigate factors influencing career preparation behavior among male nursing students in South Korea. Methods: Data were collected from May 25 to June 17, 2018 and a total of 158 male nursing students participated in this study. Career decision making self-efficacy, military duty planning, and career preparation behavior were measured using a structured questionnaire. Collected data were analyzed with SPSS 25.0 for windows. Results: There was a statistically significant difference in career preparation behavior of participants according to entrance motivation and desired career after graduation. There were statistically significant correlations between career decision making self-efficacy and career preparation behavior (r=.65, p<.001), and between military duty planning and career preparation behavior (r=.45, p<.001). The influential factors for career preparation behavior were career decision making self-efficacy (${\beta}=.64$, p<.001), and military duty planning (${\beta}=.42$, p<.001). These factors accounted for 42% of the variance in career preparation behavior. Conclusion: The results of this study indicate that to improve career preparation behavior for male nursing students, it is necessary to enhance career decision making self-efficacy and military duty planning.