Pusan National University

About: Pusan National University is a education organization based out in Busan, South Korea. It is known for research contribution in the topics: Catalysis & Population. The organization has 24124 authors who have published 45054 publications receiving 819356 citations. The organization is also known as: Busan National University & Pusan University.

Role of Toll‐Like Receptors on Human Adipose‐Derived Stromal Cells

Abstract: Adult mesenchymal stem cells (MSCs) are promising tools for such applications as tissue engineering and cellular therapy. It is not clear how stem cells exposed to unfavorable conditions (e.g., hypoxia or inflammation) respond to signals of danger after in vivo transplantation. Toll-like receptors (TLRs) play a major role in the immune system, participating in the initial recognition of microbial pathogens and pathogen-associated components. This study was designated to determine the role of TLRs in human MSCs. Reverse transcriptase-polymerase chain reaction (RT-PCR) and flow cytometry analysis demonstrated that MSCs derived from human adipose tissue and bone marrow express TLR-1, TLR-2, TLR-3, TLR-4, TLR-5, TLR-6, and TLR-9. We investigated induction of the differentiation and proliferation of human adipose tissue stromal cells (hADSCs) by TLR agonists, including flagellin, peptidoglycans (PGN), lipopolysaccharide (LPS), the synthetic double-stranded RNA analog poly(I:C), and synthetic CpG oligodeoxydinucleotide (CpG-ODN). None of these agonists, except ODN, affected the proliferation of hADSCs. LPS and PGN increased osteogenic differentiation, but CpG-ODN decreased it. Poly(I:C) itself did not affect adipogenic or osteogenic differentiations, but exerted a synergistic effect on LPS- or PGN-induced osteogenic differentiation. RT-PCR analysis demonstrated that LPS and PGN induce osteogenic markers in hADSCs. TLR agonists affected the expression of chemokines and cytokines differentially. Furthermore, hADSCs affected the expression of specific TLRs in vitro under hypoxic conditions. These data provide evidence of a nonimmune role for TLR signaling on MSCs and may provide clues to the behavior of transplanted MSCs in vivo.

Sliding-Mode Antisway Control of an Offshore Container Crane

Abstract: In this paper, a sliding-mode control for an offshore container crane is discussed. The offshore container crane is used to load/unload containers between a huge container ship (called the “mother ship”) and a smaller ship (called the “mobile harbor”), on which the crane is installed. The purpose of the mobile harbor is to load/unload containers in the open sea and transport them to shallower water where they can be offloaded at existing conventional ports, thereby obviating the need for expansive and expensive new facilities. The load/unload control objective is to suppress the pendulum motion (i.e., “sway”) of the load in the presence of the wave- and wind-induced movements (heave, roll, and pitch) of the mobile harbor. A new mechanism for lateral sway control, therefore, is proposed as well. A sliding surface is designed in such a way that the longitudinal sway of the load is incorporated with the trolley dynamics. The asymptotic stability of the closed-loop system is guaranteed by a control law derived for the purpose. The proposed new mechanism can suppress lateral sway, which functionality is not possible with conventional cranes. Simulation results are provided.

Properties of Graphene/Waterborne Polyurethane Nanocomposites Cast from Colloidal Dispersion Mixtures

Abstract: Nanocomposites of waterborne polyurethane (WPU) reinforced with functionalized graphene sheets (FGSs) were effectively prepared by casting from a colloidal dispersion of FGS and WPU, and the morphology and physical properties were examined. The finer aqueous FGS dispersions or WPU with smaller particles yielded nanocomposites with enhanced electrical conductivity and thermal resistance due to finely dispersed FGS. The FGS nucleated the crystallization of the polycaprolactone (PCL) segments in WPU and improved its modulus. However, FGS inhibited crystal growth and deteriorated the tensile properties at high deformation, i.e., tensile strength and elongation at break, because the interaction between FGS and WPU hindered the chain rearrangement of WPU in the nanocomposite.

Directed and elliptic flow of charged pions and protons in Pb + Pb collisions at 40A and 158A GeV

Abstract: Directed and elliptic flow measurements for charged pions and protons are reported as a function of transverse momentum, rapidity, and centrality for 40A and 158A GeV Pb+Pb collisions, as recorded by the NA49 detector. Both the standard method of correlating particles with an event plane and the cumulant method of studying multiparticle correlations are used. In the standard method the directed flow is corrected for conservation of momentum. In the cumulant method elliptic flow is reconstructed from genuine four-, six-, and eight-particle correlations, showing the first unequivocal evidence for collective motion in A+A collisions at SPS energies.

The strength characteristics of aluminum honeycomb sandwich panels

Abstract: Aluminum sandwich construction has been recognized as a promising concept for structural design of lightweight transportation systems such as aircraft, high-speed trains and fast ships. The aim of the present study is to investigate the strength characteristics of aluminum sandwich panels with aluminum honeycomb core theoretically and experimentally. A series of strength tests are carried out on aluminum honeycomb-cored sandwich panel specimen in three point bending, axial compression and lateral crushing loads. Simplified theories are applied to analyze bending deformation, buckling/ultimate strength and crushing strength of honeycomb sandwich panels subject to the corresponding load component. The structural failure characteristics of aluminum sandwich panels are discussed. The test data developed are documented.