• Journal of Animal Reproduction and Biotechnology
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• v.36 no.4
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• pp.307-313
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• 2021

Traf4 (Tumor necrosis factor Receptor Associated Factor 4) is a member of the tumor necrosis factor receptor (TNFR) - associated factors (TRAFs) family. TRAF4 is overexpressed in tumor cells such as breast cancer and associated with cytoskeleton and membrane fraction. Interestingly, TRAF4 was localized with tight junctions (TJs) proteins including OCLN and TJP1 in mammary epithelial cells. However, the expression patterns and biological function of Traf4 were not examined in preimplantation mouse embryos although Traf4-deficient mouse showed embryonic lethality or various dramatic malformation. In this study, we examined the temporal and spatial expression patterns of mouse Traf4 during preimplantation development by qRT-PCR and immunostaining, and its biological function by using siRNA injection. We found upregulation of Traf4 from the 8-cell stage onwards and apical region of cell - cell contact sites at morula and blastocyst embryos. Moreover, Traf4 knockdown led to defective TJs without alteration of genes associated with TJ assembly but elevated p21 expression at the KD morula. Taken together, Traf4 is required for TJs assembly and cell proliferation during morula to blastocyst transition.

• Structural Engineering and Mechanics
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• v.63 no.4
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• pp.551-565
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• 2017

In this paper, an analytical approach is proposed for determining vibration characteristics of cracked non-uniform continuous Timoshenko beam carrying an arbitrary number of spring-mass systems. This method is based on the Timoshenko beam theory, transfer matrix method and numerical assembly method to obtain natural frequencies and mode shapes. Firstly, the beam is considered to be divided into several segments by spring-mass systems and support points, and four undetermined coefficients of vibration modal function are contained in each sub-segment. The undetermined coefficient matrices at spring-mass systems and pinned supports are obtained by using equilibrium and continuity conditions. Then, the overall matrix of undetermined coefficients for the whole vibration system is obtained by the numerical assembly technique. The natural frequencies and mode shapes of a cracked non-uniform continuous Timoshenko beam carrying an arbitrary number of spring-mass systems are obtained from the overall matrix combined with half-interval method and Runge-Kutta method. Finally, two numerical examples are used to verify the validity and reliability of this method, and the effects of cracks on the transverse vibration mode shapes and the rotational mode shapes are compared. The influences of the crack location, depth, position of spring-mass system and other parameters on natural frequencies of non-uniform continuous Timoshenko beam are discussed.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.10.2-10.2
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• 2011

The design and synthesis of protein-like polymers is a fundamental challenge in materials science. A biomimetic approach is to explore the impact of monomer sequence on non-natural polymer structure and function. We present the aqueous self-assembly of two peptoid polymers into extremely thin two-dimensional (2D) crystalline sheets directed by periodic amphiphilicity, electrostatic recognition and aromatic interactions. Peptoids are sequence-specific, oligo-N-substituted glycine polymers designed to mimic the structure and functionality of proteins. Mixing a 1:1 ratio of two oppositely charged peptoid 36 mers of a specific sequence in aqueous solution results in the formation of giant, free-floating sheets with only 2.7 nm thickness. Direct visualization of aligned individual peptoid chains in the sheet structure was achieved using aberration-corrected transmission electron microscopy. Specific binding of a protein to ligand-functionalized sheets was also demonstrated. The synthetic flexibility and biocompatibility of peptoids provide a flexible and robust platform for integrating functionality into defined 2D nanostructures. In the later part of my talk, we describe the use of metal ions to construct two-dimensional hybrid films that have the ability to self-heal. Incubation of biomimetic peptoid polymers with specific divalent metal ions results in the spontaneous formation of uniform multilayers at the air-water interface. We anticipate that ease of synthesis and transfer of these two-dimensional materials may have many potential applications in catalysis, gas storage and sensing, optics, nanomaterial synthesis, and environmentally responsive scaffolds.

• Bulletin of the Korean Chemical Society
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• v.35 no.6
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• pp.1784-1788
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• 2014

The present study suggests a novel method to produce raspberry-like microparticles containing diverse functional materials inside. The raspberry-like microparticles were produced from a random assembly of uniformly-sized poly(methyl methacrylate) (PMMA) nanoparticles via electrospraying. The solution containing the PMMA nanoparticles were supplied through the inner nozzle and compressed air was emitted through the outer nozzle. The air supply helped fast evaporation of acetone, so it enabled copious amount of microparticles as dry powder. The microparticles were highly porous both on the surface and interiors, hence various materials with a function of UV-blocking ($TiO_2$ nanoparticles and methoxyphenyl triazine) or anti-aging (ethyl(4-(2,3-dihydro-1H-indene-5-carboxyamido) benzoate)) were loaded in large amount (17 wt % versus PMMA). The surface and interior structures of the microparticles were dependent on the characteristics of functional materials. The results clearly suggest that the process to prepare the raspberry-like microparticles can be an excellent approach to generate functional microstructures.

• Journal of the Korean Institute of Landscape Architecture
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• v.29 no.5
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• pp.60-70
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• 2001

This landscape design proposal was presented to a design competition for Gwangjin-gu Community Center and Assembly Hall. The site is located in 227-7 Jayang-dong, Gwangjin-gu, Seoul and is part a block designated as \`Kunkuk University Detailed Planning District\`. The judging criteria for landscape design set by the Gwangjin-gu could be articulated as follows: an identity of Gwangjin-gu, a relationship with surrounding environment, a locale as a community center of Gwangjin-gu, and an environment-friendly design. An identity of Gwangjin-gu was expressed by introducing lends and decks around the building which were transformed from the image of the old Gwangjin Ferry. The concept\` was strengthened by \`Nori-madang\` or Korean version of \`plaza\` which was designed by a motive of \`mungsuk\` or Korean old fashioned straw mat. An ambiguous relationship between the site and the surroundings was set by \`transparent exhibition frame\` which not only bleaks the massive Chungdam-daegyo, an elevated road, and frames it into small parts, but also attracts pedestrians toward the site-the \`park\`. Pedestrians from the adjacent\` Nengdong-ro Walkable Streets\` views the site through the many parts of frames. By introducing diverse resting and dynamic spaces for many kinds of cultural activities the site could function as a locale of the Gwangjin-gu community. The main paving system reflects the environment- friendly design. It was detailed by \`PC-block-deck-paving\` which was elevated from the ground so that rains could be absorbed.

• The Plant Pathology Journal
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• v.32 no.3
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• pp.173-181
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• 2016

Gene disruption by homologous recombination is widely used to investigate and analyze the function of genes in Fusarium fujikuroi, a fungus that causes bakanae disease and root rot symptoms in rice. To generate gene deletion constructs, the use of conventional cloning methods, which rely on restriction enzymes and ligases, has had limited success due to a lack of unique restriction enzyme sites. Although strategies that avoid the use of restriction enzymes have been employed to overcome this issue, these methods require complicated PCR steps or are frequently inefficient. Here, we introduce a cloning system that utilizes multi-fragment assembly by In-Fusion to generate a gene disruption construct. This method utilizes DNA fragment fusion and requires only one PCR step and one reaction for construction. Using this strategy, a gene disruption construct for Fusarium cyclin C1 (FCC1), which is associated with fumonisin B1 bio-synthesis, was successfully created and used for fungal transformation. In vivo and in vitro experiments using confirmed fcc1 mutants suggest that fumonisin production is closely related to disease symptoms exhibited by F. fujikuroi strain B14. Taken together, this multi-fragment assembly method represents a simpler and a more convenient process for targeted gene disruption in fungi.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2002.11a
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• pp.21-26
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• 2002

Solder flip chip bumping and subsequent coining processes on PCB were investigated to solve the warpage problem of organic substrates for high pin count flip chip assembly by providing good co-planarity. Coining of solder bumps on PCB has been successfully demonstrated using a modified tension/compression tester with height, coining rate and coining temperature variables. It was observed that applied loads as a function of coined height showed three stages as coining deformation : (1) elastic deformation at early stage, (2) linear increase of applied load, and (3) rapid increase of applied load. In order to reduce applied loads for coining solder bumps on PCB, effects of coining process parameters were investigated. Coining loads for solder bump deformation strongly depended on coining rates and coining temperatures. As coining rates decreased and process temperature increased, coining loads decreased. Among the effect of two factors on coining loads, it was found that process temperature had more significant effect to reduce applied coining loads during the coining process. Lower coining loads were needed to prevent substrate damages such as micro-via failure and build-up dielectric layer thickness change during applying loads. For flip chip assembly, 97Pb/Sn flip chip bumped devices were successfully assembled on organic substrates with 37Pb/Sn coined flip chip bumps.

• Journal of the Korea Institute of Military Science and Technology
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• v.25 no.6
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• pp.561-571
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• 2022

An optical mirror assembly is an opto-mechanically coupled system as the optical and mechanical behaviors interact. In the assembly, a flexure mount attached to an optical mirror should be flexible in the radial direction, but rigid for the remaining degrees of freedom for supporting the mirror rigidly and suppressing the wavefront error of the optical mirror. This work presents an optimal design of the flexure mount using topology optimization with thermal stress constraint. By simplifying the optical mirror assembly into finite shell elements, topology optimization model was built for efficient design and good machinability. The stress at the boundary between the optical mirror and the mount together with the first natural frequency were applied as constraints for the optimization problem, while the objective function was set to minimize the strain energy. As a result, we obtained the optimal design of the flexure mount yielding the improved wavefront error, proper rigidity, and machinability.

• IEMEK Journal of Embedded Systems and Applications
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• v.2 no.3
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• pp.145-154
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• 2007

Dynamic update of kernel can change kernel functionality and fix bugs in runtime. Dynamic update is important because it leverages availability, reliability and flexibility of kernel. An instruction-granularity update technique has been used for dynamic update. However, it is difficult to apply update technique for a commodity operating system kernel because development and maintenance of update code must be performed with assembly language. To overcome this difficulty, we design the function-granularity dynamic update system which uses high-level language such as C language. The proposed update system makes the development and execution of update convenient by providing the development environment for update code which is same for kernel development. We implement this system for Linux and demonstrate an example of update for do_coredump() function which is reported it has a vulnerable point for security. The update was successfully executed.

• Korean Institute of Interior Design Journal
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• v.15 no.4 s.57
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• pp.37-45
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• 2006

The purpose of this study is to stand assembly the meaning and function of entry space with analysing their social and cultural characteristic. The entry space is the linkable place between inner space and out space, and that is the transition place to be experienced two opposing characteristic. Till now the entry space has not taken effect as symbol needed to the resident and observer, and that has been a tendency to shrink as the minimal sign of entrance. So thus, it is in need of studying the entry space's specific and characterizing structurally as expanded function. For the purpose, this study define newly the meaning, function and composition of entry space in an apartment building, and try to find how to reinforce a resident identity. This study propose justification that the entry space isn't boxing space minimally but enforcing symbol presented clearness of composition and vital character.