Sequence- and site-specific photodissociation at 266 nm of protonated synthetic polypeptides containing a tryptophanyl residue

Oh, Joo Yeon,Moon, Jeong Hee,Kim, Myung Soo John Wiley Sons, Ltd. 2004 Rapid communications in mass spectrometry Vol.18 No.22

<P>Photodissociation at 266 nm of protonated synthetic polypeptides containing a tryptophanyl residue was investigated using a homebuilt tandem time-of-flight mass spectrometer equipped with a matrix-assisted laser desorption/ionization source. Efficient photodissociation of the protonated peptides was demonstrated. Most of the intense peaks in the laser-induced tandem mass spectra were sequence ions. Furthermore, sequence ions due to cleavages at all the peptide bonds were observed; this is a feature of the technique that is particularly useful for peptide sequencing. Fragmentations at both ends of the tryptophanyl residue were especially prevalent, which can be useful for location of the tryptophanyl chromophore in a peptide. Copyright © 2004 John Wiley & Sons, Ltd.</P>

Effects of the flow rate of O₂ annealing ambient on structural and electrical properties of n+ emitter junctions formed using screen‐printed phosphorus diffusion process

Kim, Jin‐,Sung,Yun, Hyung‐,Joong,Seo, Min‐,Woo,Janardhanam, V.,Ahn, Kwang‐,Soon,Choi, Chel‐,Jong John Wiley Sons, Ltd 2012 Surface and interface analysis Vol.44 No.11

<P>We have investigated the effects of the flow rate of O<SUB>2</SUB> annealing ambient on the structural and electrical properties of the emitters with n+/p junctions formed using the screen printing of phosphorus (P) dopant paste, followed by O<SUB>2</SUB> annealing. The reaction between P‐paste and Si led to the formation of phosphorus silicate glass layer, of which P atoms were mostly segregated in surface and interface regions. The sheet resistance of the screen‐printed n+ emitters formed under O<SUB>2</SUB> flow rate of 5 l/min (LPM) was lower than that of 1 LPM. The recombination mechanism dominated the current transport in the forward bias regions of the screen‐printed n+ emitter, regardless of O<SUB>2</SUB> flow rate. The n+ emitter formed under O<SUB>2</SUB> flow rates of 5 LPM exhibited better rectification behavior with low reverse leakage, as compared with that of 1 LPM. The formation of thicker phosphorus silicate glass film caused by the increase in the O<SUB>2</SUB> flow rate resulted in the increase in the equilibrium concentration of Si interstitials in bulk Si and provided more P atoms being incorporated in n+/p emitter junction. The increases in maximum concentration of P atoms and junction depth caused by the increase in the O<SUB>2</SUB> flow rate could be responsible for superior junction quality of n+ emitter formed under O<SUB>2</SUB> flow rates of 5 LPM. Copyright © 2012 John Wiley & Sons, Ltd.</P>

Growth of ZnO nanorod arrays by hydrothermal method using homo-seed layers annealed at various temperatures

Bae, Young Sook,Kim, Dong Chan,Ahn, Cheol Hyoun,Kim, Jae Hyun,Cho, Hyung Koun John Wiley Sons, Ltd. 2010 Surface and interface analysis Vol.42 No.6

<P>Vertically arrayed ZnO nanorods were synthesized by a hydrothermal method on homo-seed layers deposited using a sol-gel process and heat-treated at various temperatures ranging from 400 to 700 °C in air. The effect of the annealing temperatures on nanorod formation was investigated. With increasing temperature, the microstructure of the ZnO seed layers changed from nanocrystals to coarse polycrystals with a preferred orientation, which led to an increase in the length and diameter of the hydrothermally grown nanorods. The ZnO nanorods, based on a solution process, exhibited deep-level emission in the orange-red region related with hydroxyl group reactions, while the thermally treated seed layers showed oxygen vacancy-related emission. Copyright © 2010 John Wiley & Sons, Ltd.</P>

A network selection scheme for multicast applications in wireless network convergence

Kim, Jaecheol,Lee, Ji Hoon,Lee, Hojin,Kwon, Taekyoung,Choi, Yanghee John Wiley Sons, Ltd 2012 WIRELESS COMMUNICATIONS AND MOBILE COMPUTING Vol.12 No.11

<P><B>ABSTRACT</B></P><P>In wireless network convergence, each mobile host is expected to have multiple kinds of wireless interfaces. Multicast‐based applications are expected to be widely deployed. In this paper, a new network selection scheme is proposed for a mobile host to select the most appropriate wireless access network to maximize user satisfaction and ISP's profit, simultaneously. We have devised a metric to measure a user's satisfaction and we also developed a ‘normalized network resource’ metric for system profit measure. We have compared our scheme with three other reference schemes, through simulations. Depending on the network deployment situations, our scheme exhibits one‐fifth service disruption time of other reference schemes, while the resource consumption of our scheme is comparable to that of the minimum resource scheme. Overall, the gain of our scheme becomes higher as users move faster and/or the population density increases. Copyright © 2010 John Wiley & Sons, Ltd.</P>

A new computational approach to contact mechanics using variable-node finite elements

Kim, Jong Hoon,Lim, Jae Hyuk,Lee, Jun Ho,Im, Seyoung John Wiley Sons, Ltd. 2008 International Journal for Numerical Methods in Eng Vol.73 No.13

<P>In this paper, a new computational strategy for two-dimensional contact problems is developed with the aid of variable-node finite elements within the range of infinitesimal deformations. The variable-node elements, which are among MLS (moving least square)-based finite elements, enable us to transform node-to-surface contact problems into node-to-node contact problems. This contact formulation with variable-node elements leads to an accurate and effective solution procedure, needless to mention that the contact patch test is passed without any additional treatment. Through several numerical examples, we demonstrate its simplicity and the effectiveness of theproposed scheme. Copyright © 2007 John Wiley & Sons, Ltd.</P>

Identification and characterization of a novel heparin-binding peptide for promoting osteoblast adhesion and proliferation by screening an Escherichia coli cell surface display peptide library

Kim, Hyoun-Ee,Kim, Hae-Won,Jang, Jun-Hyeog John Wiley Sons, Ltd. 2009 Journal of Peptide Science Vol.15 No.1

<P>Heparin/heparan sulfate (HS) plays a key role in cellular adhesion. In this study, we utilized a 12-mer random Escherichia coli cell surface display library to identify the sequence, which binds to heparin. Isolated insert analysis revealed a novel heparin-binding peptide sequence, VRRSKHGARKDR, designated as HBP12. Our analysis of the sequence alignment of heparin-binding motifs known as the Cardin–Weintraub consensus (BBXB, where B is a basic residue) indicates that the HBP12 peptide sequence contains two consecutive heparin-binding motifs (i.e. RRSK and RKDR). SPR-based BIAcore technology demonstrated that the HBP12 peptide binds to heparin with high affinity (K<SUB>D</SUB> = 191 nM). The HBP12 peptide is found to bind the cell surface HS expressed by osteoblastic MC3T3 cells and promote HS-dependent cell adhesion. Moreover, the surface-immobilized HBP12 peptide on titanium substrates shows significant increases in the osteoblastic MC3T3-E1 cell adhesion and proliferation. Copyright © 2008 European Peptide Society and John Wiley & Sons, Ltd.</P>

Framed slotted aloha based MAC protocol for low energy critical infrastructure monitoring networks

Sanaullah Chowdhury, M.,Ullah, Niamat,Ameen, Mosaddique Al,Kwak, Kyung Sup John Wiley Sons, Ltd 2014 International Journal of Communication Systems Vol.27 No.10

<P><B>SUMMARY</B></P><P>Recently, the IEEE TG4k has been formed to amend the IEEE 802.15 family to address the low energy critical infrastructure monitoring networks. The purpose is to facilitate point to multi‐thousands of point communication to collect the scheduled and event data from a large number of nonmains powered endpoints that are widely dispersed. It should support low energy operation, which is necessary for multiyear battery life. Other major features are application data rate up to 40 Kb/s, thousands of endpoints per mains powered infrastructure, asymmetric application data flow, small and infrequent messages, tolerant to data latency, etc. In this paper, we present a discussion on low energy critical infrastructure monitoring networks. We propose a medium access control protocol based on framed slotted aloha for these networks. We investigated probable packet sizes, energy consumptions, battery lifetime and the success rate for our protocol. The proposed protocol is simple to implement. Simulation results show that it is efficient in terms of packet success rate, energy consumption, and battery lifetime.Copyright © 2012 John Wiley & Sons, Ltd.</P>

Buddleja officinalis inhibits high glucose-induced matrix metalloproteinase activity in human umbilical vein endothelial cells

Lee, Yun Jung,Kang, Dae Gill,Kim, Jin Sook,Lee, Ho Sub John Wiley Sons, Ltd. 2008 Phytotherapy research Vol.22 No.12

<P>The aim of the present investigation was to investigate whether an aqueous extract of Buddleja officinalis (ABO), a traditional Korean herbal medicine, suppresses the endothelial extracellular matrix degradation under high glucose condition. The incubation with high concentration of glucose (25 mM) increased significantly matrix metalloproteinase (MMP)-2/-9 expressions and activities in primary cultured human umbilical vein endothelial cells (HUVEC). Pretreatment with ABO decreased high glucose-induced increase of MMP-2/-9 activities in a dose-dependent manner. Real time qRT-PCR revealed that high glucose-induced MMP-2/-9 mRNA expression levels were attenuated by pretreatment with ABO. High glucose-induced MCP-1 and IL-8 mRNA expression levels also decreased by ABO. ABO decreased high glucose-induced hydrogen peroxide production, oxidative stress marker. These results provide new insights into the pathophysiological mechanisms for anti-inflammatory properties of ABO in vascular diseases associated with diabetes mellitus. Copyright © 2008 John Wiley & Sons, Ltd.</P>

An IMM algorithm with federated information mode-matched filters for AGV

Kim, Yong-Shik,Hong, Keum-Shik John Wiley Sons, Ltd. 2007 International journal of adaptive control and sign Vol.21 No.7

<P>In this paper, a tracking algorithm for autonomous navigation of automated guided vehicles (AGVs) is presented. The developed navigation algorithm is an interacting multiple-model (IMM) algorithm used to detect other AGVs using fused information from multiple sensors. In order to detect other AGVs, two kinematic models were derived: A constant-velocity model for linear motion, and a constant-speed turn model for curvilinear motion. In the constant-speed turn model, a nonlinear information filter (IF) is used in place of the extended Kalman filter (KF). Being equivalent to the KF algebraically, the IF is extended to N-sensor distributed dynamic systems. The model-matched filter used in multi-sensor environments takes the form of a federated nonlinear IF. In multi-sensor environments, the information-based filter is easier to decentralize, initialize, and fuse than a KF-based filter. In this paper, the structural features and information-sharing principle of the federated IF are discussed. The performance of the suggested algorithm using a Monte Carlo simulation is evaluated under the three navigation patterns. Copyright © 2006 John Wiley & Sons, Ltd.</P>

Film characteristics of anodic oxidized AZ91D magnesium alloy by applied power

Jang, Yong Seok,Kim, Yu Kyoung,Park, IL Song,Lee, Sook Jeong,Lee, Min Ho,Yoon, Jeong Mo,Bae, Tae Sung John Wiley Sons, Ltd. 2009 Surface and interface analysis Vol.41 No.6

<P>This study examined the film characteristics of an anodized AZ91D magnesium alloy by varying the direct current and pulse frequency conditions. In order to evaluate the effect of the pulse frequency on film formation, anodic oxidation was carried out by applying direct current and pulse current at a current density of 300 mA/cm<SUP>2</SUP>. Compared with the sample groups treated with the direct current, a large number of small arcs were generated continuously on the film treated with the pulse current and the film formation rate was found to increase. Homogeneous and compact pores were formed with increasing frequency, and the rate of formation was increased rapidly to the arrival voltage. The film thickness increased and the surface roughness decreased with increasing anodic oxidation time at a fixed frequency of 125 Hz. However, treatment for more than 3 min led to decomposition of the oxidized film onto the previously formed film, which caused an increase in the number of cracks and pores within the film. The most uniform and smallest pores were acquired when the surface was anodized for 3 min at a current density and frequency of 300 mA/cm<SUP>2</SUP> and 125 Hz, respectively. X-ray diffraction revealed the formation of MgO and Mg<SUB>2</SUB>SiO<SUB>4</SUB> peaks, with a relative decrease in peak intensity for the MgO and Mg substrate. The Vickers hardness value was higher on the treated groups than on the untreated group, and the potentiodynamic polarization test revealed satisfactory corrosion resistance through a decrease in corrosion density and a large improvement in the corrosion potential. Copyright © 2009 John Wiley & Sons, Ltd.</P>