Following the previous study, the toxicity of a single subcutaneous administration of the Thyrokitty injection (I-131) and the side effects that may occur at therapeutic doses were confirmed. The Thyrokitty injection (I-131) was administered subcutaneously once at a dose of 0, 2.0, 6.0, and 18.0 mCi/kg, 5 male and female rats per group, and mortality, general symptom observation, and weight measurement were performed for 2 weeks, followed by observation of autopsy findings. There were no deaths, and no statistically significant weight change was observed. Mild hair loss, fissures, and crusting were observed by general symptom observation, but it was not a toxic change related to the Thyrokitty injection (I-131). Gastric atrophy and a decrease in the size of the spleen were observed by the autopsy. As a results of single subcutaneous administration of the Thyrokitty Injection (I-131) to rats at a maximum dose of 18.0 mCi/kg, a decrease in the size of the spleen and gastric atrophy were observed as the dose of the Thyrokitty Injection (I-131) increased, which may be related to the test substance. No abnormal findings related to the Thyrokitty injection (I-131) were observed. Therefore, the approximate lethal dose of the Thyrokitty injection (I-131) was 18.0 mCi/kg or more. In addition, as reported for the treatment of feline hyperthyroidism with radioiodine (131I), side effects of the Thyrokitty injection (I-131) are expected to be extremely rare. Temporary dysphagia and fever may occur, but it will recover naturally. It should be administered with caution in cats with diseases such as urinary system, cardiovascular system, gastrointestinal system and endocrine system, especially with kidney disease. And it should not be used in cats who are pregnant, lactating, or likely. It is expected that the Thyrokitty injection (I-131) can be used for clinical treatment in Korea as a veterinary drug.

Radioiodine (131I) has been used for the treatment of feline hyperthyroidism since the 1990s in the USA and Europe, and it is recommended as the most effective treatment for feline hyperthyroidism because it has a high therapeutic effect, small side effects, and does not require anesthesia. In this study, the pharmacological properties of the Thyrokitty injection (I-131), which is being developed as a treatment for feline hyperthyroidism, using radioiodine (131I) as an active ingredient, was tested. The %cell uptake of the Thyrokitty injection (I-131) in FRTL- 5 thyroid cells was 0.410 ± 0.016%, which was about 18 times higher compared to Clone 9 hepatocytes, and it was decreased by 30.7% due to the competitive reaction with iodine (sodium iodide). In addition, the %cell growth of the FRTL-5 thyroid cells was reduced by 25.0% by treatment with the Thyrokitty injection (I-131). As a result of the tissue distribution test, the Thyrokitty injection (I-131) was distributed at the highest concentration at 0.083 hours (5 minutes) after subcutaneous administration to animals in most organs except the stomach, small intestine, large intestine, muscle and thyroid gland, and it was excreted mainly through the kidneys. The stomach and thyroid gland showed a typical distribution pattern observed when radioiodine (131I) was administered. In addition, about 78.45% of the total amount of excretion was excreted within 48 hours, of which more than 85% was excreted in urine. In conclusion, the Thyrokitty injection (I-131) has the same mechanism of action, potency, absorption, distribution, metabolism and excretion characteristics as radioiodine (131I) reported in connection with the treatment of feline hyperthyroidism. In the future, using the results of this study, it is expected that the Thyrokitty (I-131) could be safely used in the clinical treatment of feline hyperthyroidism.

PURPOSES : The aim of this study is to evaluate the effects of air voids, binder content, and aggregate gradation on the indirect tensile strength (IDT) and cracking tolerance index (CTindex) of cored asphalt pavements. METHODS : Cored samples were obtained from roads in Incheon city, and several laboratory experiments were performed. First, the cored samples were first to cut into a size appropriate for the IDT test. Subsequently, the air voids of the samples were measured. The damaged sample from the IDT test was loose mixed at 150 ℃ before the binder content was determined, which was conducted via an asphalt extraction test. Finally, the clean aggregates obtained from asphalt extraction process were analyzed in the aggregate gradation test. RESULTS : The result shows that an increase in air voids from 4% to 8% decreases the IDT and cracking tolerance index (CTindex) by 30% and 28%, respectively. Incorporating a binder enhances the ductile behavior of the asphalt mixture, resulting in a higher CTindex. Finally, the contribution of the aggregate grade on the IDT and CTindex is negligible. CONCLUSIONS : The IDT and CTindex are primarily affected by the air voids and binder content. A higher percentage of air voids results in a lower IDT. In addition, a higher amount of binder increases the IDT and CTindex of the cored samples. Meanwhile, the aggregate grade does not affect the IDT.

Natural environmental resources are considered a prospective source of microorganisms capable of producing biocatalysts with great potential in industrial areas. Arable soil fertilized with peat moss is a habitat for various microorganisms. The present research focused on the isolation and identification of hydrolase-producing bacteria that thrive at a broad temperature range. In this study, a total of 33 strains were isolated from arable soil fertilized with peat moss (Silla Garden in Busan, South Korea). The isolated bacteria were mesophiles and thermophiles with a wide temperature range. Taxonomic identification showed that the isolated strains belonged to 2 phyla, 5 families, 10 genera, and 24 species. Subsequently, the isolated strains were screened for hydrolase (amylase, lipase, and protease) activity. All isolates possessed activity of at least one enzyme and six bacterial isolates produced combined extracellular enzymes. Diversity of soil bacteria species in the present study suggest the potential of soil bacteria in the various industrial applications.

Since nuclear power plant (NPP) dismantling carries the possibility of radiation exposure from a hazardous environment, it’s important to minimize that by using a remote manipulator et al. However, due to complexity of nuclear facilities, it’s necessary for operators to increase their proficiency by operating in advance in a virtual environment. In this research, we propose a virtual manipulator system using a haptic device for NPP’s reactor vessel internals (RVI) dismantling which can realistically manipulate.

In this work, we introduce a 100 kW class mobile plasma melting system designed for non-combustible radioactive wastes treatment. To ensure mobility, the designed system consists of two 24-ft commercial containers, each in charge of the plasma utilities and melting process. In the container for plasma utilities, a 100 kW class DC power supply is installed together with a chiller and gas supply system whereas the container for melting process has a transferred type arc melter as well as off-gas treatment system consisting of a heat exchanger, filtrations, scrubber and NOx removal system. As a heat source for a transferred type arc melter, we adopted a hollow electrode plasma torch with reverse polarity discharge structure. Detailed design for a 100 kW class mobile plasma melting system will be presented together with the main specifications of the components. In addition, the basic performance data of the melting system is also presented and discussed.

This study reports Chinese and Korean university EFL students’ perceptions of and attitudes toward online and face-to-face English language learning modes during COVID-19. Few previous studies have focused on how students thought of online and face-to-face learning experiences of subjects regarding new concept learning and delivery of new contents. Research gravitating around English courses showed students' mixed perceptions. The survey was conducted for 302 Korean and 337 Chinese university students who took communication-oriented English courses. Descriptive statistics and qualitative data analysis were used for analysis. Results indicated that students preferred face-to-face English learning with some specific indications of achieving a stronger help and quality for communicative competence in language. Online learning also benefited students with a sense of both flexibility and independence. Positive components of face-to-face learning for language education might be considered for online education while incorporation features such as flexibility and independence to enrich language education during COVID-19.

The growth characterization and enzyme productivity of halotolerant microorganisms isolated from the Nakdong River estuary wetland in Korea were investigated in this study. The isolation of halotolerant microorganisms was carried out through their cultivation at 37oC for several days using a marine agar medium. After a single-colony isolation, 16 pure colonies were obtained, and phylogenetic analysis was done using 16S-based ID service in the EzBioCloud database. The isolated strains were divided into 3 phyla, 5 families, 7 genera, and 13 species. Possible industrial applications of the strains were confirmed upon testing for amylolytic, lipolytic, and proteolytic activity to confirm the possible production of hydrolytic enzymes, growth at a pH range of 5 to 9, and various salt concentrations being tested. Thirteen strains possessed at least one enzyme activity, and 5 strains possessed 2 enzyme activities. Eight strains could tolerate up to 10% NaCl concentration. This result indicated that isolated strains had shown the possible application in food and cosmetic industries. Therefore, this study would contribute to securing domestic biological resources and improving hydrolytic enzyme activity using these strains.