• Journal of the korean academy of Pediatric Dentistry
• /
• v.50 no.2
• /
• pp.168-178
• /
• 2023

Objectives: This study aimed to compare the physical properties and antibacterial effectiveness of iodoform based root filling pastes, Vitapex^® and Metapex^®, with sodium iodide root filling paste (NaI paste) for primary teeth. Materials and Methods: The physical properties (flowability, film thickness, radiopacity) of the pastes were evaluated according to ISO 6876:2012. The antibacterial activity against Enterococcus faecalis strain (ATCC 6538) was evaluated using a direct contact test. Results: There was no significant statistical difference (p > 0.05) observed in the flow and film thickness of NaI paste when compared to the currently available root canal filling materials. The average flow capacities for Vitapex^®, Metapex^®, and NaI paste were 15.40 mm, 21.25 mm, and 20.01 mm, respectively. The average film thickness for Vitapex^®, Metapex^®, and NaI paste were 33.3 ㎕, 22.6 ㎕, and 25.0 ㎕, respectively. However, NaI paste showed lower radiopacity than the existing materials, and this difference was statistically significant (p < 0.05) NaI paste demonstrated higher antimicrobial activity than the available materials, and this difference was also statistically significant (p < 0.05). Conclusion: Compared to the existing commercialized root canal filling materials, NaI paste exhibited similar performance in terms of flow and film thickness, and superior antimicrobial activity against E. faecalis. Hence, NaI paste could be a promising root filling material for primary teeth and may be a potential alternative to existing materials.

• Journal of Korean Dental Hygiene Science
• /
• v.6 no.1
• /
• pp.37-50
• /
• 2023

Background: This study investigated the structural relationships among justice, test anxiety, and school reliability s non-face-to-face tests of dental hygiene students. Methods: A survey was conducted with 267 dental hygiene students. The survey items included general characteristics, opinions on evaluation, the fairness of non-face-to-face tests (distributive, procedural, and interactional justice), school satisfaction, and school reliability. For statistical analysis, independent-sample t-tests, one-way ANOVA, and structural modeling analyses were performed. Results: Among factors that directly affected distributive justice and reliability towards non-face-to-face tests, the higher the interactional justice (β=0.401, p<0.001) and distributive justice (β=0.232, p=0.002) levels, the higher the school satisfaction. The higher the school satisfaction (β=0.606, p<0.001) and procedural justice (β=0.299, p<0.001) levels, the higher the perceived reliability of the school. Factors that indirectly affected school reliability included interactional justice (β=0.243, p=0.010) and distributive justice (β=0.141, p=0.010). Interactional justice (β=0.592, p=0.010) and distributive justice (β=0.208, p=0.010) were the factors affecting school satisfaction. Moreover, factors that influenced school reliability were distributive justice (β=0.56, p=0.010), interactional justice (β=0.332, p=0.010), procedural justice (β=0.229, p=0.010), and distributive justice (β=0.116, p=0.010). Conclusions: Students will trust and be satisfied with schools when schools and professors sufficiently provide information on face-to-face tests and ensure proper procedures to achieve reasonable grades as rewards for exerted time and effort. Furthermore, this study provides a reference base for developing a variety of content for fair, non-face-to-face tests, thereby allowing students to trust their schools.

• Pediatric Infection and Vaccine
• /
• v.30 no.2
• /
• pp.73-83
• /
• 2023

Purpose: This study aimed to investigate the viral load dynamics in children with underlying malignancies diagnosed with symptomatic coronavirus disease 2019 (COVID-19). Methods: This was a retrospective longitudinal cohort study of patients <19 years old with underlying hemato-oncologic malignancies that were diagnosed with their first symptomatic severe acute respiratory syndrome coronavirus 2 polymerase chain reaction (PCR)-confirmed COVID-19 infection during March 1 to August 30, 2022. Review of electronic medical records and telephone surveys were undertaken to assess the clinical presentations and transmission route of the patients. Thresholds of negligible likelihood of infectious virus was defined as E gene reverse transcription (RT)-PCR cycle threshold (Ct) value ≥25. Results: During the 6-month study period, a total of 43 children with 44 episodes of COVID-19 were included. Of the 44 episodes, the median age of the patients included was 8 years old (interquartile range [IQR], 4.9-10.5), and the most common underlying disease was acute lymphoid leukemia (n=30, 68.2%), followed by patients post-hematopoietic stem cell transplantation (n=8, 18.2%). Majority of the patients had mild COVID-19 (n=32, 72.7%), and three patients (7.0%) had severe/critical COVID-19. Furthermore, 2.3% (n=1) died of COVID-19 associated acute respiratory distress syndrome. The largest percentage of the patients showed E gene RT-PCR Ct value ≥25 between 15-21 days (n=13, 39.4%), followed by 22-28 days (n=10, 30.3%). In 15.2% (n=5), E gene RT-PCR Ct value remained <25 beyond 28 days after initial positive PCR. Refractory malignancy status (β, 67.0; 95% confidence interval, 7.0-17.0; P=0.030) was significantly associated with prolonged duration of E gene RT-PCR <25. A patient with prolonged duration of E gene RT-PCR Ct value <25 was suspected to have infectivity shown by the transmission of the virus to his mother at day 86 after his initial positive test. Conclusions: Children that acquire symptomatic COVID-19 during refractory malignancy state are at a high risk for prolonged shedding warranting PCR-based transmission precautions in this cohort of patients.

• Journal of Science Education
• /
• v.47 no.2
• /
• pp.192-210
• /
• 2023

This study was intended to develop the plant molecular biology experimental program using Rapid-cycling Brassica rapa (RcBr) based on the teaching steps and teaching methods of the cognitive apprenticeship model and to determine its application effects. In order to improve a subject's cognitive function and expertise on molecular biology experiments, two themes composed of a total 8 class sessions were selected: 'Identification of DFR gene in purple RcBr and non-purple RcBr' and 'Identification of RcBr's genetic polymorphism site using the DNA profiling method'. Research subjects were 18 pre-service teaching majors in biology education of H University in Chungbuk, Korea. The effectiveness of the developed program was verified by analyzing the enhancement of 'cognitive function' related to the use of molecular biology knowledge and technology, and the enhancement of 'domain-general metacognitive abilities.' The effect of the developed program was also determined by analyzing the task flow diagram provided. The developed program was effective in improving the cognitive functions of the pre-service teachers on the use of knowledge and technology of molecular biology experiments. It was especially effective to improve the higher cognitive function of pre-service teachers who did not have the previous experience. The developed program also showed a significant improvement in the task of metacognitive knowledge and in the planning, checking, and evaluation of metacognitive regulation, which are sub-elements of domain-general metacognitive abilities. It was found that the developed program's self-test activity could help the pre-service teachers to improve their metacognitive regulation. Therefore, this developed program turned out to be helpful for pre-service teachers to develop core competencies needed for molecular biology experimental classes. If the teaching and learning materials of the developed program could be reconstructed and applied to in-service teachers or high school students, it would be expected to improve their metacognitive abilities.

• Journal of Practical Agriculture & Fisheries Research
• /
• v.17 no.1
• /
• pp.57-71
• /
• 2015

This study was conducted to develop the fertigation system with a peristaltic hose pump and brushless DC motor. The fertigation system was consisted of sensor, main controller, motor control unit, peristaltic pump, water supply pump, control panel, and filter. The peristaltic pump discharges liquid by squeezing the tube with rollers. Rollers attached to the external circumference of the rotor compresses the flexible tube. The fluid is contained within a flexible tube fitted inside a circular pump casing. The developed fertigation system has no mixing tank but instead injects directly a concentrated nutrient solution into a water supply pipe. The revolution speed of the peristaltic pump is controlled by PWM (Pulse width modulation) method. When the revolution speed of the peristaltic pump was 300rpm, the flow rate of the 3.2, 4.8, 6.3mm diameter tube was 202, 530, 857mL/min, respectively. As increasing revolution speed, the flow rate of the peristaltic pump linearly increased. As the inner diameter of a tube larger, a slope of graph is more steep. Flow rate of three roller was more than that of four roller. Flow rate of a norprene tube with good restoring force was more than that of a pharmed tube. As EC sensor probe was installed in direct piping in comparison with bypass piping showed good performance. After starting the system, it took 16~17 seconds to stabilize EC. The maximum value of EC was 1.44~1.7dS/m at a setting value of 1.4dS/m. The developed fertigation system showed ±0.06dS/m deviation from the setting value of EC. In field test, Cucumber plants generally showed good growth. From these findings, this fertigation system can be appropriately suitable for fertigation culture for crops.

• The Korean Journal of Coaching Psychology
• /
• v.5 no.2
• /
• pp.127-170
• /
• 2021

This study developed a measure to measure wellness-seeking behavior in important areas of life for general adults in Korea and verified its validity. For the development of the wellness scale, 31 factors derived through literature review, expert interviews, in-depth interviews, open questionnaires 1 and 2, and 182 questions were selected as the final 10 factors and 99 questions. Through exploratory factor analysis of the results of the preliminary survey of 351 adults in Korea, 58 questions of 10 factors were derived, and some of the questions reflecting important concepts in each factor were revised, and this survey was conducted with 63 questions of 10 factors. In this survey conducted on 667 people, to verify the validity of the composition concept of this test, the entire sampling was divided into two groups, one group was subjected to exploratory factor analysis, and the other group was subjected to confirmatory factor analysis. As a result of exploratory factor analysis, 63 questions of 10 factors (work, community, family, others, economic power, self-esteem, leisure, physical health, spirituality, and self-growth) were finally derived, and confirmatory factor analysis using the structural equation model verified that the model fit criteria were met. Convergence validity was verified using the K-MHC-SF and Wellness Index for Workers to verify whether the derived wellness scale and its sub-factors actually measure wellness. As a result of analyzing the relationship between the variables and factors of the Subjective Happiness Scale and Life Scale to verify the validity related to the criteria, it was found to be a significant correlation. As a result of confirming the significance of each path through multiple regression analysis, the 'self-esteem' on the wellness scale was identified as the most important factor influencing subjective happiness and life satisfaction. Finally, discussions on this research process and results, academic significance and practical significance, limitations, and future research directions were presented.

• Korean Journal of Forensic Psychology
• /
• v.11 no.2
• /
• pp.135-153
• /
• 2020

Identifiable victim effect refers to the tendency of greater sympathy and helping behavior to identifiable victims than to abstract, unidentifiable ones. This research tested whether this tendency also affects third-party's punishment and compensation judgments in jury context for public's legal judgments. In addition, through the Identifiable victim effect in such legal judgment, we intended to explain the effect of 'the bill named for victim', putting the victim's real name and identity at the forefront, which is aimed at strengthening the punishment of related crimes by gaining public attention and support. To do so, we conducted experiments with hypothetical traffic accident scenarios that controlled legal components while manipulating victim's identifying information. In experiment 1, each participant read a scenario of an anonymous victim (unidentifiable condition) or a nonanonymous victim that included personal information such as name and age (identifiable condition) and made judgments on the degree of punishment and compensation. The results showed no effect of identifiability on third-party's punishment and compensation judgments, but moderation effect of BJW was obtained in the identifiable condition. That is, those with higher BJW showed greater tendency of punishment and compensation for identifiable victims. In Experiment 2, we compared an anonymous victim (unidentifiable condition) against a well-conducted victim (positive condition) and ill-conducted victim (negative condition) to test the effects of victim's characteristics on punishment for offender and compensation for victims. The results showed lower compensation for an ill-conducted victim than for an anonymous one. In addition, across all conditions except for negative condition, participants made punishment and compensation judgments higher than the average judicial precedents of 10-point presented in the rating scale. This research showed that victim's characteristics other than legal components affects third-party's legal decision making. Furthermore, we interpreted third-party's tendency to impose higher punishment and compensation with effect of 'the bill named for victim' and proposed social and legal discussion for and future research.

• Journal of Practical Agriculture & Fisheries Research
• /
• v.4 no.1
• /
• pp.128-137
• /
• 2002

This study was conducted to develop the heat exchanger by utilizing the heat energy of underground water(15℃), which might be used for cooling and heating system of the agricultural facilities. We developed the heat exchanger by using the parallel type plat fin tube made of Aluminum(Al 6063), which was named Aloo-Heat(No. 0247164, offered by Korean Intellectual property Office). The trial manufactures were made from Aloo-heat which was 600mm, 700mm length respectively, and It were welded to the end "U" type in order to direct flow of the underground water. The performance test was carried out under the condition of open space and room temperature with the change of flow rate of the underground water and air. The results are as follows. 1. The trial manufactures had convection heat value from 33 to 156 W/m²℃, and It was coincided with design assumption. 2. The amount of energy transfer was increased with the increment of the area of heat transfer, the air flow, the gap of temperature inlet & outlet the underground water and the air. 3. The heat value was 6,825W when the air flow was 6,000m³/h and the gap of temperature between inlet and outlet of the underground water was 6℃, and It dropped from 25.8℃ to 23.2℃(-2.6℃ difference). The convection heat value was 88.5W/m²℃. 4. The heat value was 2.625W when the air flow was 4,000m³/h and the gap of temperature between inlet and outlet the underground water was 2℃, and It dropped from 27℃ to 22.5℃(-4.5℃ difference). The convection heat value was 33.6W/m²℃. 5. Correlation values(R²) of the testing heat values of the trial manufacture type I, II, and III were 0.9141, 0.8935, and 0.9323 respectively, and correlation values(R²) of the amount of the air flow 6,000m³/h, 5,000m³/h, 4,000m³/h were 0.9513, 0.9414, and 0.9003 respectively.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.49 no.3
• /
• pp.231-245
• /
• 2023

In the cosmetics industry, it is important to develop new materials for functional cosmetics such as whitening, wrinkles, anti-oxidation, and anti-aging, as well as technology to increase absorption when applied to the skin. Therefore, in this study, we tried to optimize the nanoemulsion formulation by utilizing response surface methodology (RSM), an experimental design method. A nanoemulsion was prepared by a high-pressure emulsification method using Glabridin as an active ingredient, and finally, the optimized skin absorption rate of the nanoemulsion was evaluated. Nanoemulsions were prepared by varying the surfactant content, cholesterol content, oil content, polyol content, high-pressure homogenization pressure, and cycling number of high-pressure homogenization as RSM factors. Among them, surfactant content, oil content, high-pressure homogenization pressure, and cycling number of high-pressure homogenization, which are factors that have the greatest influence on particle size, were used as independent variables, and particle size and skin absorption rate of nanoemulsion were used as response variables. A total of 29 experiments were conducted at random, including 5 repetitions of the center point, and the particle size and skin absorption of the prepared nanoemulsion were measured. Based on the results, the formulation with the minimum particle size and maximum skin absorption was optimized, and the surfactant content of 5.0 wt%, oil content of 2.0 wt%, high-pressure homogenization pressure of 1,000 bar, and the cycling number of high-pressure homogenization of 4 pass were derived as the optimal conditions. As the physical properties of the nanoemulsion prepared under optimal conditions, the particle size was 111.6 ± 0.2 nm, the PDI was 0.247 ± 0.014, and the zeta potential was -56.7 ± 1.2 mV. The skin absorption rate of the nanoemulsion was compared with emulsion as a control. As a result of the nanoemulsion and general emulsion skin absorption test, the cumulative absorption of the nanoemulsion was 79.53 ± 0.23%, and the cumulative absorption of the emulsion as a control was 66.54 ± 1.45% after 24 h, which was 13% higher than the emulsion.

• The Korea Journal of Herbology
• /
• v.24 no.3
• /
• pp.1-12
• /
• 2009

Objectives : The objective of this study was to compare, the potency of toxicity of Cantharidin containing dried Mylabis phalerata (MP) extract and it's modifier. Methods ： They were monitored at dosage level 2,000, 1,000, 500, 250 and 125 mg/kg, respectively. Changes of body weight, clinical signs, mortality, LD50, macroscopic changes of gastrointestinal tract and liver were observed after single oral dose of test articles with changes of serum Gastrin and Somatostatin levels. Results ： Dosage-dependent decrease of body weight and/or gains were demonstrated in dried MP extract-dosing groups, were also detected in modified and dried MP extract-dosing groups at 2,000 and 1,000 mg/kg-dosing group. However, below 500 mg/kg-dosing group, the body weights were significantly increased compared to that of equal dosage group of dried MP extract-dosing group. Dosage-dependently detected clinical signs in dried MP extract-dosing groups, were also detected in modified and dried MP extract-dosing groups at 2,000 and 1,000 mg/kg-dosing group. However, below 500 mg/kg-dosing group, these clinical signs dramatically were decreased compared to that of equal dosage group of dried MP extract-dosing group. Dosage-dependent increase of mortality rates were observed in dried MP extract-dosing groups, were also detected in modified and dried MP extract-dosing groups at 2,000 and 1,000 mg/kg-dosing group. However, below 500 mg/kg-dosing group, the mortalities were significantly decreased compared to that of equal dosage group of dried MP extract-dosing group. The LD50 of dried MP extract in male mice was dramaticlly increased in their modify, 265.86 vs 426.99 mg/kg. Dosage-dependently increase of number of hemorrhagic and/or erythematous spots detected in the gastrointestinal tracts of dried MP extract-dosing groups, were also detected in modified and dried MP extract-dosing groups at 2,000 and 1,000 mg/kg-dosing group. However, below 500 mg/kg-dosing group, these abnormal spots were dramatically decreased compared to that of equal dosage group of dried MP extract-dosing group. Dosage-dependently increase of degrees of enlargement and congestion detected in the liver of dried MP extract-dosing groups, were also detected in modified and dried MP extract-dosing groups at 2,000 and 1,000 mg/kg-dosing group. However, below 500 mg/kg-dosing group, these abnormal signs were dramatically decreased compared to that of equal dosage group of dried MP extract-dosing group. Dosage-dependently increase of serum gastrin levels of dried MP extract-dosing groups, were also detected in modified and dried MP extract-dosing groups at 2,000 and 1,000 mg/kg-dosing group. However, below 500 mg/kg-dosing group, these abnormal increase were dramatically decreased compared to that of equal dosage group of dried MP extract-dosing group. Dosage-dependently increase of serum somatostatin levels of dried MP extract-dosing groups, were also detected in modified and dried MP extract-dosing groups at 2,000 and 1,000 mg/kg-dosing group. However, below 500 mg/kg-dosing group, these abnormal increase were dramatically decreased compared to that of equal dosage group of dried MP extract-dosing group. Conclusions ： The toxicity of dried MP extract was reduced by their modify.