• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.21 no.1
• /
• pp.21-29
• /
• 1988

This study was carried out to develop the powdered Katsuobushi (a kind of boiled, smoked, and dried fish product which is used for seasoning soup as it is.) using skipjack as a natural flavoring substance. The processing conditions of the powdered Katsuobushi and the changes of taste compounds during processing of the products were examined. In preparation of the powdered Katsuobushl, frozen skipjack was thawed, beheaded, gutted, filleted and then sliced to 1cm of thickness. The silted meats were boiled in skipjack extract for 20 minutes, and then it was smoked for, 3 times to $10\~12\%$ moisture content at $80^{\circ}C$ for 8 hours. The smoked - dried meats were followed to be 50 mesh of particle size. The effect of slicing and boiling in skipjack meat extract on enhancing flavor and on preventing lipid oxidation of product during processing were observed. The moisture content and crude lipid content of the powdered Katsuobushi was in the range of 11 to $12\%$ and 4.3 to $4.8\%$, respectively. The taste compounds of the product were nucleotides and their related compounds, 1135.8mg/100g ; free amino acid and related compounds, 2210.2mg/100g ; non-volatile organic acids, 1148.0mg/100g ; and total creatinine. 592.1mg/100g on dry basis, and small amount of betaine and TMAO. The major elements of mineral in the product were found to be K, Mg, Na, and Ca. The content of IMP was 542.0mg/100g, and major free amino acids were found to be histidine, anserine, taurine, carnosine and alanine of which occupied to $83.6\%$ of total free amino acids. In non -volatile organic acids, major ones were lactic acid, succinic acid, pyroglutamic acid and $\alpha-ketoglutaric$ acid. From the results of the chemical experiments and sensory evaluation, we may conclude that the flavor of the product from present experiment is more desirable than that of conventional products although the processing time used were much shortened than that of conventional method, and it can be commercialized as a seasoning powder.

• The Journal of Korean Society for Radiation Therapy
• /
• v.17 no.1
• /
• pp.33-40
• /
• 2005

Purpose : We recently perform the latest radiotheraphy (3D conformal, IMRT,etc.) with the development of 3D CT planning technology. However, in case patients with breast cancer, it is difficult to acquire the CT image with the limitation of CT hole size and tilting of breast immobilization device. The Ewha Breast Device(EBD) was constructed to improve the problem in the treatment of patients with breast cancer and we are intend to introduce the procedure of the EBD construction in this study and compare the EBD with conventional breast device in the view point of usefulness. Materials and Methods : We have constructed the EBD with acryl, analyze the skull size with CT data, consider the skin folder in SCL field and evaluated the EBD usefulness from the view point of set-up reproducibility, dose distribution, skin reaction in comparison with conventional breast device. Results : In the case of patients set-up error analysis, the EBD is superior to conventional device in portal film repetition($\%$) check (80pt.), equal to that in simulation & CT image coincidence check(5pt.). There is no difference between the two systems in dose distribution and skin reaction in SCL field is better the EBD than conventional device. Conclusions : The construction of the EBD enable us to perform the latest radiotheraphy in breast treatments, relieve the pains in simulation, and reduce, the skin reaction. In the future, we expect that modification of the EBD is useful in treating for patients with breast cancer.

• Journal of the Korean Society of Radiology
• /
• v.11 no.1
• /
• pp.9-17
• /
• 2017

A high degree of precision and accuracy in Gamma Knife Radiosurgery(GKRS) is a fundamental requirement for therapeutical success. Elaborate radiation delivery and dose gradients with the steep fall-off of radiation are clinically applied thus necessitating a dedicated Quality Assurance(QA) program in order to guarantee dosimetric and geometric accuracy and reduce all the risk factors that can occur in GKRS. In this study, as a part of QA we verified the accuracy of single-shot dose profiles used in the algorithm of Gamma Knife Perfexion(PFX) treatment planning system employing Variable Ellipsoid Modeling Technique(VEMT). We evaluated the dose distributions of single-shots in a spherical ABC phantom with diameter 160 mm on Gamma Knife PFX. The single-shots were directed to the center of ABC phantom. Collimating configurations of 4, 8, and 16 mm sizes along x, y, and z axes were studied. Gamma Knife PFX treatment planning system being used in GKRS is called Leksell GammaPlan(LGP) ver 10.1.1. From the verification like this, the accuracy of GKRS will be doubled. Then the clinical application must be finally performed based on precision and accuracy of GKRS. Specifically the width at the 50% isodose level, that is, Full-Width-of-Half-Maximum(FWHM) was verified under such conditions that a patient's head is simulated as a sphere with diameter 160mm. All the data about dose profiles along x, y, and z axes predicted through VEMT were excellently consistent with dose profiles from LGP within specifications(${\leq}1mm$ at 50% isodose level) except for a little difference of FWHM and PENUMBRA(isodose level: 20%~80%) along z axis for 4 mm and 8mm collimating configurations. The maximum discrepancy of FWHM was less than 2.3% at all collimating configurations. The maximum discrepancy of PENUMBRA was given for the 8 mm collimator along z axis. The difference of FWHM and PENUMBRA in the dose distributions obtained with VEMT and LGP is too small to give the clinical significance in GKRS. The results of this study are considered as a reference for medical physicists involved in GKRS in the whole world. Therefore we can work to confirm the validity of dose distributions for all collimating configurations determined through the regular preventative maintenance program using the independent verification method VEMT for the results of LGP and clinically assure the perfect treatment for patients of GKRS. Thus the use of VEMT is expected that it will be a part of QA that can verify and operate the system safely.

• Korean Journal of Ichthyology
• /
• v.32 no.3
• /
• pp.166-181
• /
• 2020

The egg development, early life history and spawning site characters of Korean endemic fish, Coreoleuciscus splendidus (Gobioninae), were investigated at the part of Jo-jong stream in Korea from May 2020. The fertilized eggs were 2.05~2.23 mm (mean, 2.13 mm) in diameter and had no oil globules. The embryo began to hatching about 98 hrs after fertilization under water temperature of 20±1℃. The newly-hatched larvae were 5.03~5.68 mm (mean, 5.31 mm) in total length (TL), and their mouth and anus were not opened. 4 days after hatching, Several rod-like cupulae were observed on the head and lateral side of the body at 6.95~7.89 mm (mean, 7.51 mm). 7 days after hatching, the post-larva stage were 8.39~9.29 mm (mean, 8.78 mm) in total length, and their york were completely absorbed. The cupulae were completely distinguished. They entered the juvenile stage when all fin-rays were formed at 29 days after hatching, and their TL were 14.16~17.04 mm (mean, 14.99 mm). Squamation was initiated on the caudal body at approximately 18.21~23.74 mm (mean, 30.28 mm), 38 days after hatching, and completed at 26.82~33.33 mm (mean, 19.42 mm), 73 days after hatching, the external characteristics from of juveniles were same to adults. The spawning site was characterized by bottom structure of pebble (64~16 mm) and gravel (16~2 mm), environmental conditions of the spawning sites were 6~18 cm in water depth, 0.43~0.73 m/sec in bottom water velocity. In spawning sites, an egg mass or separated eggs were located a small gap of under the pebble and gravel.

• Investigative Magnetic Resonance Imaging
• /
• v.14 no.2
• /
• pp.103-114
• /
• 2010

Purpose : To generate a Korean specific brain template, especially in patients with Alzheimer's disease (AD) by optimizing the voxel-based analysis. Materials and Methods : Three-dimensional T1-weighted images were obtained from 123 subjects who were 43 cognitively normal subjects and patients with 44 mild cognitive impairment (MCI) and 36 AD. The template and the corresponding aprior maps were created by using the matched pairs approach with considering differences of age, gender and differential diagnosis (DDX). We measured several characteristics in both our and the MNI templates, including in the ventricle size. Also, the fractions of gray matter and white matter voxels normalized by the total intracranial were evaluated. Results : The high resolution template and the corresponding aprior maps of gray matter, white matter (WM) and CSF were created with the voxel-size of $1{\times}1{\times}1\;mm$. Mean distance measures and the ventricle sizes differed between two templates. Our brain template had less gray matter and white matter areas than the MNI template. There were volume differences more in gray matter than in white matter. Conclusion : Gray matter and/or white matter integrity studies in populations of Korean elderly and patients with AD are needed to investigate with this template.

• Korean Journal of Heritage: History & Science
• /
• v.53 no.4
• /
• pp.188-197
• /
• 2020

Termites play an important role as decomposers of the forest ecosystem, while simultaneously causing enormous damage to wooden structures. Currently, two species of subterranean termites have been reported in Korea, and termite damage to historical wooden buildings is occurring nationwide due to climate change, forest fertility, and the locational characteristics of historical wooden buildings. Subterranean termites make their nests underground or inside timber. Termites move underground and access wooden structures through the lower parts of the buildings, adjacent to the ground. Once termites attack the wooden structures, it not only spoils the authenticity of cultural heritage structure, but also hampers structural stability due to the decrease in the strength of the material. Therefore, it is important to prevent termite damage before it occurs. Chemical treatments are mainly used in Korea to control and prevent the damage. In foreign countries, physical barriers are also used to prevent entry to wooden buildings, along with chemical treatments. Physical barriers involve installing nets or particles that termites cannot pass through in the lower part of the building, around the pipes, and between the edges of the building or exterior walls and interior materials. Advantages of a physical barrier are that it is an eco-friendly method, maintains long-term effect after installation, and does not require the use of chemical treatments. Prior to applying physical barriers, studies into the characteristics of termite species must be undertaken. In this study, we evaluated the minimum passage size that each caste of Reticulitermes speratus kyushuensis can move through. We found that workers, soldiers, and secondary reproductive termites were able to pass through diameters of 0.7mm, 0.9mm, and 1.1mm respectively. Head height of termites was an important factor in determining the minimum passing size. Results from the current study will be used as a basis to design the mesh size for physical barriers to prevent damage by termites in historical wooden buildings in Korea.

• Korean Journal of Ichthyology
• /
• v.35 no.2
• /
• pp.91-100
• /
• 2023

The early life history of Silurus microdorsalis living in Jahocheon Stream was studied by observing egg and morphological development. Live fish were captured in June 2018, then reared in a circulating filtration system under a 14L : 10D photoperiod with a water temperature of 18℃. To artificially induce spawning, females were injected with 0.5 mL of Ovaprim (Syndel, Nanaimo, BC, Canada) per kg of body weight, and males were injected with 10,000 IU/kg body weight of human chorionic gonadotropin. Approximately 15 h later, eggs were artificially inseminated by the dry method. Mature eggs were light pale yellow, which separated them from immature eggs. Fertilized eggs were 2.16±0.06 mm (n=8) in diameter and fully hatched at 181 h after fertilization. The fertilization rate was 63.1±2.2%, and 10.0±3.7% of the embryos were malformed at 18℃. The rates of development were 181 h at 18℃, 109 h at 21℃, and 76 h at 24℃. The larval size immediately after hatching was 4.64±0.22 mm (n=8), and the larvae displayed negative phototaxis at 1 day after hatching. The total larval length on 7 days after hatching was 12.47±0.53 mm, with 25~30 basal anal fin rays and 14~16 basal caudal fin rays observed. The total larval length was 14.13±0.51 mm on 9 days after hatching, and approximately 90% of the black endoplasmic reticulum was deposited on the head and body. The dorsal fin had formed, and a single basal body was observed. On 15 days after hatching, the total larval length was 16.69±0.31 mm; the number of basal caudal fin rays (18 poles) was an integer because 2 dorsal fin basal rays and 60~63 anal fin basal rays were observed. The total larval length was 28.96±1.10 mm on 50 days after hatching; the numbers of caudal fins (n=18), dorsal fins (n=3), pectoral fins (n=11), and anal fin basal rays (n=67~73) were integers.

• Korean Journal of Ichthyology
• /
• v.36 no.2
• /
• pp.120-128
• /
• 2024

In this study, the characteristics of the early life history were investigated for the Hypomesus nipponensis in the west coast Daeho Bay. Egg's were adhesive eggs that had the property of sinking in water in a circular shape. The size of mature eggs was 0.52~0.66 (average of 0.59±0.03, n=30) mm. The hatching time took 140 hours at a water temperature of 22~23℃. Immediately after hatching, the yolk sac larvae was 4.78~5.60 (average of 5.25±0.26, n=30) mm in total length, and the mouth and anus were not completely opened. On the 7 days after hatching, the preflexion larvae was 5.91~6.64 (6.32±0.21) mm in total length, and the mouth and anus were opened, and feeding activities were started. On the 25 days after hatching, the flexion larvae was 9.70~12.3 (10.2±0.63) mm in total length, and the end of the spine at the tail end began to bend upward. On the 42 days after hatching, the postflexion larvae was 14.1~18.8 (16.9±1.44) mm in total length, and the end of the spine at the tail was completely bent at 45°. On the 56 days after hatching, it reached the integer with 10 dorsal fins, 16 anal fins, 7 ventral fins, and 19 caudal fins. According to the study, there were spot-shaped melanophore vesicles under the pectoral fins during the incubation period, the different positions of the egg yolk compared to the battlefield, the deposition of melanophore vesicles on the back and under the body of the caudal part during the postflexion larvae period, and the absence of melanophore vesicles on the torso between the head and the starting point of the dorsal fin. It was distinguished from related species in that melanophore vesicles were deposited in one row from the back of the body to the caudal part during the juvenile period.

• Korean Journal of Ichthyology
• /
• v.36 no.2
• /
• pp.109-119
• /
• 2024

This study was conducted to investigate the early life history by observing the egg development of Ladislavia taczanowskii in endangered fish and to use it as basic data for species conservation research. The broodstork used in the study was secured from the area of the Hongcheon River in Hongcheon-gun, Gangwon State. The broodstork, who was being raised in the laboratory, selected mature individuals in May 2021 and induced them to spawn by hormone injection. The size of the maturation egg was 1.50~1.79 (average 1.59±0.08, n=30) mm due to the circular invasive egg. The incubation time took 168 hours at 16.5℃ and 109 hours and 30 minutes at 25.5℃. Newly hatched larvae, the consonants had a total length of 5.55~6.31 mm (6.30±6.93, n=30) mm, and the mouth and anus did not open and had egg yolk. 5 days after hatching, the preflexion larvae had a total length of 9.91~10.8 (10.1±0.27, n=30) mm, and the mouth and anus opened, and feeding activities began. 8 days after hatching, the flexion larvae had a total length of 10.3~11.4 (10.8±0.38, n=30) mm, and the end of the vertebrae at the tail fin tip began to bend upward. 10 day after hatching, the postflexion larvae had a total length of 11.8~13.1 (12.3±0.43, n=30) mm, and the end of the vertebrae at the tail tip was completely bent at 45°. 18 days after hatching, the total length of the juveniles was 18.9~23.4 (20.4±1.69, n=30) mm, and the number of fins in each part was fin rays with 10 dorsal fins, 9 anal fins, 22 caudal fins, and 7 ventral fins. As a result of the study, the postflexion larvae showed differences in morphology from other Gobioninae fishes in the upper part of the tail's hypural, the shape of spots on the dorsal vertebrae, the vertical stripes developed on the head, and the irregularly deposited melanophore throughout the body.