• Applied Microscopy
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• v.28 no.1
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• pp.73-82
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• 1998

To elucidate how microfilaments and vesicles participate in bile formation, the pericanalicular cytoplasms were observed in the liver of rats treated with taurocholic acid by deep etching with rapid freezing, and copmpared them with the findings on convensional thin sections. The microfilaments were identified around the bile canaliculi in the forms of core filaments of microvilli, filaments of pericanalicular web running in parallel to the border of bile canaliculi, and filaments on the junctional complex. In taurocholic acid-treated rats, microfilaments could be visualized around the bile canaliculi and along their borders. The microfilaments appeared to be installed to link to both the canalicular membrane and vesicles. Such specialized microfilaments are considered to participate in the translocation of vesicles in the pericanalicular cytoplasm. From the evidence, it is assumed that the microfilament induces the vesicles to transport and fuse to bile canalicull into which bile acids is secreted by exocytosis.

• The Journal of the Korea Contents Association
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• v.20 no.3
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• pp.10-17
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• 2020

This study examines the interaction effects between branded contents' ending types(happy ending, non-happy ending) and the level of product involvement(high involvement, low involvement) on consumer's negative responses. Results suggest that the level of product involvement had no significant effect on consumer responses since product on video clips was not closely linked to the contents' message. Selective empathy is identified as the happy ending type of branded contents had a greater effect on consumer's negative responses than the non-happy ending type of. It is an apparent new phenomenon shown among the young after 2000s. Moreover, the interaction between contents' ending types and the level of product involvement had a significant effect on consumer's negative responses. Two interaction terms (i.e. happy ending and low product involvement; non-happy ending and high product involvement) are the viable message strategies to weaken the consumer responses in terms of 'dislike'.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.3
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• pp.383-387
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• 2000

Fusion is defined as union of two separate tooth buds at some stage in their development with confluence of dentin and characterized by separate root canal and large single crown, while gemination is defined as an attempt of the single tooth bud to incompletely divide and usually result in a single root with one root canal and two completely or incompletely separated crowns. It is sometimes difficult to decide whether an abnormally large tooth is the result of fusion of a normal and a supernumerary tooth, or of gemination; use of the term 'Double tooth' may make the clinicians avoid this difficulty(Brook & Winter). Commonly there are no symptoms, but the problems associated with these anomalies include esthetics, possible loss of arch length and delayed or ectopic eruption of the permanent teeth, caries along the line of demarcation, and periodontal disease. Commonly, it dose not need to be treated in primary dentition but in case of permanent dentition, it may be requested to be treated due to esthetics and other problems. In our case, a 8 years old girl showed a Double tooth, we attained the favorable results by performing hemisection with apexification.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.10
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• pp.1075-1081
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• 2011

A leak-detection method has been developed by measuring the pressure variation between the inner and outer heattransfer tubes of a double-wall tube steam generator. An experiment was carried out to measure the leak rate in the gap between two surfaces pressed with a hydraulic press in order to simulate the phenomena, and a correlation was determined for the leak rate in a micro gap. However, in the correlation, the gap width and friction coefficient were coupled with the surface roughness, which affects the two parameters. The two parameters were separated using a surface-contact model to develop a correlation for the friction coefficient. The correlation was compared with the existing correlations used for crack analysis. Although the applied ranges of Reynolds numbers were different, the developed correlation for Reynolds numbers of 0.1.0.35 showed similar tendencies to existing correlations used for higher Reynolds numbers.

• Nuclear Engineering and Technology
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• v.26 no.2
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• pp.197-204
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• 1994

In a PWR rod cluster control assembly(RCCA) for shutdown is released upon action of control rod drive mechanism and falls down through the guide thimble by its weight. Drop time and impact velocity of the RCCA are two key parameters with respect to reactivity insertion time and the mechanical integrity of fuel assembly. Therefore, the precise control of drop time and impact velocity is prerequisite to modifying the existing design features of the RCCA and guide thimble or newly designing them. During its falling down into the core, the RCCA is retarded by various forces acting on it such as fluid resistance caused by the RCCA movement, buoyance and mechanical friction caused by contacting inner surface of the guide thimble, etc. However, complicated coupling of the various forces makes it difficult to derive an analytical dynamic equation for the drop time and impact velocity. This paper deals with the development of a computer program containing an analytical dynamic equation applicable to the Korean Fuel Assembly(KOFA). The computer program is benchmarked with an available single control rod drop tests. Since the predicted values are in good agreement with the test results, the computer program developed in this paper can be employed to modify the exiting design features of the RCCA and guide thimble and to develope their new design features for advanced nuclear reactors.

• School Mathematics
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• v.10 no.4
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• pp.557-571
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• 2008

The objective of this paper is to study De Morgan's thoughts on teaching and learning negative numbers. We studied De Morgan's point of view on negative numbers, and analyzed his didactical approaches for negative numbers. De Morgan make students explore impossible subtractions, investigate the rule of the impossible subtractions, and construct the signification of the impossible subtractions in succession. In De Morgan' approach, teaching and learning negative numbers are connected with that of linear equations, the signs of impossible subtractions are used, and the concept of negative numbers is developed gradually following the historic genesis of negative numbers. Also, we analyzed the strengths and weaknesses of the De Morgan's approaches compared with the mathematics curriculum.

• Journal of Korea Technology Innovation Society
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• v.20 no.4
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• pp.915-938
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• 2017

This study examines the case of living lab led by intermediary and explores the development possibility as living lab platform. The analyzed cases are 'The Seoul Innovation Park Living lab', 'Korea Senior Living lab' of Seongnam Senior Experience complex, and 'Disaster Safety Living lab'. As a result of the analysis, all three cases have formed a user panel to form a living lab platform, and provide living lab service to internal and external organizations. A common feature that combines a technology platform with a 4Ps-based governance platform is identified. However, the characteristics, the meaning, and the process are different from case to case. In the future, the living lab platform needs to share learning experiences that are going on individually, since domestic living lab platform is in the early stage. Through this, it is necessary to seek collaboration and cooperation with related similar projects, and to jointly promote institutional and physical infrastructures related to living labs.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.4
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• pp.569-578
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• 2007

This study was performed to compare the shear bond strength of self etching system and two bottle bonding system with or without laser preparation. Group I was prepared with high speed rotary instrument and $Prompt^{TM}$ L-$Pop^{TM}$, group II with Er:YAG laser and $Prompt^{TM}$ L-$Pop^{TM}$, group III with Er:YAG laser, 37% phosphoric acid and Single bond, group IV with Er:YAG laser and Single bond and group V with high speed, etching and Single bond. And also observation of the prepared and etched dentin surface were performed under scanning electro-microscope. The possibility of clinical application of laser preparation which might have an advantage to reduce pain for children with less unfavorable noise were evaluated. The results obtained are as follows; 1. Group V showed significantly higher bond strength than other groups. And group IV showed significantly lower bond strength than other groups. 2. There was no significant difference between group I and group III. 3. Group II showed significantly lower bond strength than group I, III, V, but showed significantly higher bond strength than group IV. 4. Under scanning electro-microscope, laser-preparated dentin surface showed high irregularity and no smear layer. The surface showed less irregularities and more exposed dentinal tubules with etching. Laser preparation has many advantages over conventional tooth preparation. But this method showed lower resin bonding strength. Laser preparated tooth surface differed from the conventionally preparated tooth surface. More researches are needed on suitable methods for laser preparated dentin surface.

• Journal of Life Science
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• v.33 no.7
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• pp.531-537
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• 2023

Intracellular and axonal transport is mediated by microtubule-dependent motor proteins, such as kinesins and cytoplasmic dynein. Kinesin moves along the microtubule to the positive end of the microtubule, while dynein moves to the negative end of the microtubule. Kinesin-1 was first identified as a kinesin superfamily protein (KIF) that functions in the intracellular transport of various cargoes, including organelles, neurotransmitter receptors, and mRNA-protein complexes, through interactions between the carboxyl (C)-terminal domain and the cargo. It interacts with other cargoes, but the adapter/scaffold proteins that mediate between kinesin-1 and the cargo have yet to be fully identified. In this study, a yeast two-hybrid screen was used to identify adapter proteins that interact with the C-terminal region of KIF5A. We found an association between the C-terminal region of KIF5A and the cyclin-dependent kinase 2-associated protein 1 (CDK2AP1), originally identified in malignant hamster oral keratinocytes. CDK2AP1 bound to the C-terminal region of KIF5A and did not interact with KIF3A (the motor of kinesin-2), KIF5B, KIF5C, and kinesin light chain 1 (KLC1). The C-terminal region of CDK2AP1 is essential for its interaction with KIF5A. When co-expressed in HEK-293T cells, CDK2AP1 and kinesin-1 co-immunoprecipitated and co-localized in the cells. These results suggest that the KIF5A-CDK2AP1 interaction serves as an adapter protein connecting kinesin-1 and the cargo when kinesin-1 transports cargo in cells.

• Applied Biological Chemistry
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• v.17 no.2
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• pp.117-124
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• 1974

The 23 representative bacteria were studied for the glucosamine contents which represent the glycolipid content of the cell wall. The distribution of glycolipid in various bacteria was examined and the relationship between the glycolipid contents and the Gram stain was elucidated. The results were as follows: 1. The contents of glucosamine in the glycolipid of Gram negative and variable bacterial cell wall were large ranging from the least 0.04 ${\mu}g$ of Proteus vulgaris to the largest 2.48 ${\mu}g$ of Aerobacter aerogenes. The Gram positive bacteria and only those Gram positive among Bacilli contained less than 0.02 ${\mu}g$ of glucosamine contents. The least glucosamine containing Gram positive bacteria were Corynebacterium sepedonicum and Staphylococcus aureus. It could generally be said that the Gram negative and variable bacteria contain the higher content of glucosamine in the cell wall than the positives. 2. The bacteria were better stained by the Gram solution after the extraction of glycolipid from the cell wall than those without extraction. 3. The four infrared spectra of glycolipids obtained from Aerobacter aerogenes, Bacillus circulans, Pseudomonas fluorescens, and Salmonella typhirurium showed all the similar characteristics. All showed the existence of groups; OH, C-O, C-O-C, $CH_2+CH_3$, amide band, fatty acid ester band and ester carbonyl bond.