Soo-Ho Lee

Electrical properties of plasma display panel with Mg1−xZnxO protecting thin films deposited by a radio frequency magnetron sputtering method

In order to improve the material properties of the protective layer for alternating current plasma display panels, a small amount of ZnO was added to the MgO protective layer. The electrical properties and the surface characteristics of the Mg1−xZnxO films, deposited by a radio frequency magnetron sputtering method, were investigated. As the concentration of ZnO increases, the crystallinity of Mg1−xZnxO thin films improves and the grain size becomes larger. The firing and the sustaining voltages of panels with the Mg1−xZnxO protective layers, when the concentration of ZnO was 0.5at.%, was reduced by 20V, compared with the conventional panels with the MgO protective layers. It was also found that the panels with Mg1−xZnxO protective layers show the higher discharge intensity as the ZnO content increases at the same applied voltages, compared with panels with the conventional MgO protective layers.

Pick1 modulates ephrinB1-induced junctional disassembly through an association with ephrinB1

Members of the Eph family have been implicated in the formation of cell-cell boundaries, cell movement, and positioning during development in the context of cancer progression. De-regulation of this signaling system is linked to the promotion of more aggressive and metastatic tumor phenotypes in a large variety of human cancers, including breast, lung, and prostate cancer, melanoma, and leukemia. Thus, it is interesting to consider the case of cancer progression where de-regulation of the Eph/ephrin signaling system results in invasion and metastasis. Here, we present evidence that Pick1, one of the essential components of the adherens junction, recovers ephrinB1-induced cell-cell de-adhesion. Loss of Pick1 leads to dissociation of epithelial cells via disruption of the adherens junction, a phenotype similar to ephrinB1 overexpression. In addition, overexpressed ephrinB1-induced disruption of the adherens junction is rescued via binding to Pick1. These data indicate that Pick1 is involved in regulating the cell-cell junction in epithelial cells, and this may influence therapeutic strategy decisions with regards to cell adhesion molecules in metastatic disease.

The splicing factor SRSF1 modulates pattern formation by inhibiting transcription of tissue specific genes during embryogenesis

Alternative splicing is a major mechanism regulating pattern of gene expression through the production of multiple mRNAs from a single gene transcript. Any misregulation can cause various human diseases and also have severe effects on embryogenesis. SRSF1 is one of the critical factors regulating alternative splicing at many stages of vertebrate development and any disturbance in SRSF1 leads to serious consequences. In current study, we investigated the effects of loss of the SRSF1 gene using antisense morpholino oligonucleotides (MO) in Xenopus embryogenesis. It is evident from the results of RT-PCR and whole-mount in situ hybridization that SRSF1 is a maternal gene having strong expression in head, eyes and central nervous system. Moreover, SRSF1 morphants exhibited malformed phenotypes, including miscoiled guts, heart and cartilage formation, edema in the head and heart, and small eyes. Especially, in SRSF1 morphants, bone cartilage formation was reduced in the brain and Nkx-2.5 expression was dramatically reduced in the heart of SRSF1 morphants. In addition, a dramatic reduction in functional chordin RNA in SRSF1 morphants was observed suggesting that chordin is one of the targets of SRSF1. Thus, we concluded that SRSF1 is an essential factor for pattern formation including heart, cartilage and germ layers through the regulation of specific genes.

NSrp70 is significant for embryonic growth and development, being a crucial factor for gastrulation and mesoderm induction

NSrp70 (nuclear speckle-related protein 70), a recently discovered protein and it belongs to the serine/arginine (SR) rich related protein family. NSrp70 is recognized as an important splicing factor comprising RNA recognition motif (RRM) and arginine/serine (RS)-like regions at the N- and C-terminus respectively, along with two coiled coil domains at each terminus. However, other functions of NSrp70 remain unelucidated. In this study, we investigated the role of NSrp70 in Xenopus embryogenesis and found that its maternal expression plays a critical role in embryonic development. Knockdown of NSrp70 resulted in dramatic reduction in the length of developing tadpoles and mild to severe malformation in Xenopus embryos. In addition, knockdown of NSrp70 resulted in an extremely short axis by blocking gastrulation and convergent extension. Further, animal cap assays along with activin A treatment revealed that NSrp70 is an essential factor for dorsal mesoderm induction as knockdown of NSrp70 caused a dramatic down-regulation of dorsal mesoderm specific genes and its loss significantly shortened the elongation region of animal caps. In conclusion, NSrp70 is crucial for early embryonic development, influencing gastrulation and mesoderm induction.

Fire Prevention Measures and Characteristic of Warehouse Fire during Joseon Dynasty

It is told that disaster is learnt from disaster. In this aspect, the first approach to disaster today is to analyze the patterns and sizes of fire by building up the database for disasters occurred in the past. In order to preserve our cultural property buildings from fire, this study built up warehouse fires data table of the Joseon Dynasty period and analyzed its fire cases like below. According to warehouse fires data table, the total number of fire in the Joseon Dynasty period was 154 cases while there was a periodic relation between fire occurrence number and periodic dynasty. The most cause of warehouse fire is by blundering and about half of fired warehouse store the grain. Territorially, the Hansungbu(Seoul) is the highest rate of warehouse fire in all of regions and cities.

Analysis on Crowd Movement Behaviour in a One-way Corridor

The purpose of this study is to draw for characteristics of crowd movement in a corridor. Generally, a corridor determines the number of floating population who moves to other places. Therefore, to solve the congestion caused by specific area such as exit door, the study of crowd movement in corridor is needed. In this study, to inquire the relationship between the number of participant with crowd, density and flow, a full-scale experiment has been done in acorridor which has 1.2m width. The result was that crowd speed decreased as increasing the number of participants. For that crowd speed, the head-participant speed in front of crowd was predominated for crowd speed. Also the modified equation for crowd density-crowd speed suggested through measured crowd density and speed.

A Study on the Escalator Evacuation Model Using the buildingEXODUS

As the buildings are going to be highest and biggest, elevator and escalator are used as the main vertical transportation in building. Especially, because of high transport rate in escalator, occupants prefer to use escalator. In this paper, movement characteristics are analyzed for applying escalator evacuation model and modelling several scenarios using the buildingEXODUS against real fire. Before this study, occupants survey are conducted about awareness of emergency exit location and vertical means of evacuation. After, considering of real evacuation(which has high density), subway station is suitable because of high flow movement. Peak time is extracted as observing CCTV. Therefore, in this extracted peak time, escalator and stair usage, walker and rider usage and occupants speed are extracted. Therefore, this study re-acted and evacuation simulation which had been conducted three kinds of scenarios. These scenarios contain percentage of escalator/stair usage, walker/rider usage and escalator movement situation. The simulation results demonstrate that escalator strategies and associated human factors can have a considerably influence upon and evacuation compared to using stairs alone.

A 10 GBPS Interchip Optical Interconnection Module for Optical Circuit Board Application

We report on fabrication of a 10 Gbps optical interconnection module that can be used as optical printed circuit board (O-PCB) for CPU-and-memory optical interconnection to replace serialized electrical bus signal in a computer system.