bluuebunny/crossref_metadata_2025 huggingface dataset:
Micro‐photoluminescence of GaInNAs layers grown on GaAs substrates of various crystallographic orientations
Authors: Latkowska M. , Kudrawiec R. , Sęk G. , Misiewicz J. , Ibanez J. , Hopkinson M. , Henini M.
Published: March 2011

Low temperature micro‐photoluminescence (μ‐PL) has been applied to study GaInNAs bulklike layers grown on GaAs substrates with various crystallographic orientations [(100), (111)A, (311)A, (411)A, and (511)A]. At low excitation conditions, the μ‐PL spectra show sharp PL lines of ∼100‐300 μeV widths. The density of these lines changes from sample to sample as well as from place to place within one sample. When the excitation power is increased, an additional smooth PL band appears at the higher‐energy side. This band is located ∼30‐100 meV above the band of sharp PL lines and is attributed to free exciton/carrier recombination. The sharp PL lines are attributed to the recombination of localized excitons trapped at local potential minima. These lines are not resolved in macro‐PL spectra because of their high density. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
X‐ray diffraction study of GaN grown on patterned substrates
Authors: Sintonen S. , Ali M. , Törmä P. T. , Suihkonen S. , Kostamo P. , Svensk O. , Sopanen M. , Lipsanen H. , Paulmann C. , Tuomi T. O.
Published: March 2011

Owing to its great potential in optoelectronic devices, a lot of effort has recently been put into improving the crystal quality of heteroepitaxial GaN. In this study, GaN layers grown on patterned GaN/sapphire substrates are non‐destructively investigated by X‐ray diffraction techniques. The effect of the patterning is characterized by determining the strain and lattice tilt and twist in the overgrown GaN layers.

High resolution X‐ray diffraction (HRXRD) scans and reciprocal space maps (RSMs) were utilized for this purpose. Synchrotron radiation X‐ray topography (SR‐XRT) was used to examine the microstructure of the samples. The patterning was found to significantly improve the crystal quality of the GaN layers, especially by reducing the amount of edge dislocations. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth of thick GaN layers on 4‐in. and 6‐in. silicon (111) by metal‐organic vapor phase epitaxy
Authors: Frayssinet Eric , Cordier Yvon , Schenk H. P. David , Bavard Alexis
Published: March 2011

In this paper, we report on the growth of thick gallium nitride (GaN) layers on 4‐in. and 6‐in., (111)‐orientated silicon substrates by metalorganic vapor phase epitaxy. Up to 4 µm thick continuous GaN layers have been obtained by inserting both SiN and AlN interlayers into the structure. With dislocation densities of about 1‐2×109 cm‐2 and GaN(002) and (302) X‐ray rocking curve full widths at half maximum of 420 and 1360 arcsec for 4‐in. and 374 and 810 arcsec for 6‐in., respectively, the final continuous GaN layer exhibits excellent crystalline properties (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Suppression of non‐radiative effects in AlGaN through nanometer scale compositional inhomogeneities
Authors: Sampath Anand V. , Garrett Gregory A. , Enck Ryan W. , Rotella Paul , Shen H. , Wraback Michael
Published: March 2011

UV light emitting diodes (UVLEDs) emitting at wavelengths shorter than 365 nm remain in the research and development stage, with external quantum efficiencies and device operating lifetimes well below that of commercially available blue LEDs. These limitations are partially attributable to the large density of dislocations in these devices that arise due to heteroepitaxial growth of high AlN mole fraction III‐Nitride semiconductors and act as non‐radiatve recombination centers that reduce efficiency and increase debilitating heating. An approach to mitigating this problem is to incorporate nanometer scale compositional inhomogeneities within the AlGaN (NCI‐AlGaN) active region of a UVLED that can enhance the internal quantum efficiency by concentrating carriers within regions of narrow bandgap surrounded by a wider band gap matrix. In this paper we report on the growth and characterization of NCI‐AlGaN alloys deposited by plasma‐assisted molecular beam epitaxy. Growth under N‐limited and nearly stoichiometric growth conditions promote the spontaneous formation of these NCI regions. This is attributed to lower adatom mobility of group III and N species on the AlGaN layer surface under these conditions as well as the formation of beneficial surface faceting. Optical characterization by both temperature dependent, time‐resolved and time‐integrated photoluminescence demonstrates the capability for NCI regions to suppress non‐radiative recombination in these active regions despite the presence of a large density of defects. However, reduction of the defect density, both dislocations and impurities, improves the performance of these active regions. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Asperosaponin VI, A Saponin Component from Dipsacus asper Wall, induces Osteoblast Differentiation through Bone Morphogenetic Protein‐2/p38 and Extracellular Signal‐regulated Kinase 1/2 Pathway
Authors: Niu Yinbo , Li Yuhua , Huang Haitao , Kong Xianghe , Zhang Rong , Liu Li , Sun Yang , Wang Tingmei , Mei Qibing
Published: March 2011

Osteoporosis is a reduction in skeletal mass because of the loss of osteoblastic activity or an increase in osteoclastic activity. The survival of osteoblast cells plays a crucial role in the development of osteoporosis. Asperosaponin VI (ASA VI) is a kind of saponin in the medicinal herb Dipsacus asper Wall which has long been used as an antiosteoporosis drug. The assay of cell proliferation, alkaline phosphatase (ALP) activity and measurement of mineralized matrix, showed that ASA VI exhibited a significant induction of proliferation, differentiation and mineralization in MC3T3‐E1 and primary osteoblastic cells. Induction of differentiation by ASA VI was associated with increased bone morphogenetic protein‐2 (BMP‐2), indicating that BMP‐2 is essential in ASA VI to mediate osteoblast maturation and differentiation. In addition, ASA VI may induce differentiation by increasing the activity of p38 and ERK1/2. In conclusion, ASA VI may induce osteoblast maturation and differentiation, and then increase bone formation via increasing BMP‐2 synthesis, and activating p38 and ERK1/2. Copyright © 2011 John Wiley & Sons, Ltd.
Escin Sodium Induces Apoptosis of Human Acute Leukemia Jurkat T Cells
Authors: Zhang Zhenzhen , Gao Jian , Cai Xueting , Zhao Youlong , Wang Yafei , Lu Wuguang , Gu Zhenhua , Zhang Shuangquan , Cao Peng
Published: March 2011

Escin sodium has been used in the clinic as an antioedematous, antiexudative and vasoprotective agent for many years and has shown excellent tolerability. However, little is known about its anticancer activity. This is a report for the first time that escin sodium exerts a cytotoxic effect on human acute leukemia Jurkat T cells via the induction of apoptosis rather than cell cycle arrest. Escin sodium activated the initiator caspase‐8, ‐9, and the effector caspase‐3, degraded poly (ADP‐ribose) polymerase (PARP) and attenuated the expression of Bcl‐2. In addition, escin sodium inhibited the growth of cancer cells in a selective manner with Jurkat cells most sensitive to it. Taken together, the data show that escin sodium possesses potent apoptogenic activity toward human acute leukemia Jurkat T cells. Copyright © 2011 John Wiley & Sons, Ltd.
In Vitro Antimicrobial and Antioxidant Activities of Anthrone and Chromone from the Latex of Aloe harlana Reynolds
Authors: Asamenew Gelila , Bisrat Daniel , Mazumder Avijit , Asres Kaleab
Published: March 2011

In the search for new antimicrobial and antioxidant compounds from plants, the latex of the medicinal plant Aloe harlana Reynolds from Ethiopia was subjected to bioassay‐guided fractionation, which led to the isolation of two known compounds, anthrone (aloin) and chromone (7‐O‐methylaloeresin A). The latex and its two constituents were assessed for their possible antimicrobial activities against 23 bacterial and four fungal strains using the disc diffusion method and their antioxidant activity by two complementary test systems, namely 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) and 2‐deoxyribose degradation assay methods.

The isolated compounds showed promising results against various pathogenic bacterial and fungal strains in comparison with standard drugs. Moreover, 7‐O‐methylaloeresin A exhibited good activity against multiple drug resistant Staphylococcus aureus (NCTC 11994) and Salmonella typhimurium (ATCC 1255) with MIC values of 0.72 and 0.18 mm, respectively. Among the fungal strains tested, Candida albicans (ATCC 10231) was the most susceptible organism to the latex and the two isolated compounds. The latex and isolated compounds also showed significant activities on both antioxidant assays with the highest activity being observed for 7‐O‐methylaloeresin A, which gave IC50 values of 0.026 mm and 0.021 mm for DPPH and 2‐deoxyribose degradation assay, respectively. These findings support the traditional uses of the plant for the treatment of various infectious and inflammatory diseases. Copyright © 2011 John Wiley & Sons, Ltd.
Analysis of sulfated peptides from the skin secretion of the Pachymedusa dacnicolor frog using IMAC‐Ga enrichment and high‐resolution mass spectrometry
Authors: Balderrama Griselda Demesa , Meneses Erika P. , Orihuela Lorena Hernández , Hernández Oscar Villa , Franco Ruben Castro , Robles Victoria Pando , Batista Cesar Vicente Ferreira
Published: March 2011

Immobilized metal ion affinity chromatography (IMAC) has been widely used for the enrichment of phosphopeptides, whereas no report exists describing the use of IMAC columns for the enrichment of sulfopeptides. In this study, we used IMAC‐Ga microcolumns for the enrichment of sulfopeptides from a complex mixture of peptides, extracted from skin secretions of the Pachymedusa dacnicolor frog. The enriched fraction obtained by IMAC‐Ga was analyzed by liquid chromatograpy/electrospray ionization mass spectrometry (LC/ESI‐MS) in an Orbitrap XL and by matrix‐assisted laser desorption/ionization time‐of‐flight time‐of‐flight (MALDI‐TOF/TOF) in an ABI 4800 instrument. From this fraction, different sulfated and non‐sulfated peptides belonging to the caerulin and bradykinin families were structurally characterized. Other interesting negatively charged groups, such as phosphate adducts of dermaseptins and pyridoxal phosphate attached to a protease inhibitor, were also characterized. Unexpectedly, some dermaseptin antimicrobial peptides were also enriched by IMAC‐Ga and a Sauvatine‐like peptide was also fully sequenced. Furthermore, neutral loss of sulfated peptides and their fragmentation patterns in the gas phase were also compared using collision‐induced dissociation (CID) and high‐energy collision dissociation (HCD). Our present study provides evidence that IMAC‐Ga enrichment is a fast, useful and promising method for high‐throughput analysis of sulfated‐peptides, since high‐resolution mass spectrometers can be used for this purpose. Copyright © 2011 John Wiley & Sons, Ltd.
Multiphoton ionization and Coulomb explosion of C2H5Br clusters: a mass spectrometric and charge density study
Authors: Das S. , Badani P. M. , Sharma P. , Vatsa R. K. , Das D. , Majumder A. , Das A. K.
Published: March 2011

Using time‐of‐flight mass spectrometry (TOFMS), laser‐induced photochemistry of ethyl bromide clusters has been investigated at three different wavelengths (viz. 266, 355 and 532 nm) utilizing nanosecond laser pulses of ~5 × 109 W/cm2. An interesting finding of the present work is the observation of multiply charged atomic ions of carbon and bromine at 355 and 532 nm, arising from the Coulomb explosion of (C2H5Br)n clusters. At 266 nm, however, the (C2H5Br)n clusters were found to exhibit the usual multiphoton dissociation/ionization behaviour. The TOFMS studies are complemented by measuring the total charge density of the ionized volume at 266, 355 and 532 nm, using the parallel plate method, and the charge densities were found to be ~2 × 109, 6 × 109 and 2 × 1011 charges/cm3, respectively. The significantly higher charge density and the presence of energetic, multiply charged atomic ions at 532 nm are explained by the higher ponderomotive energy of the 532 nm photon, coupled with the Coulomb stability of the residual multiply charged ethyl bromide clusters generated upon laser irradiation, due to their larger effective cluster size at 532 nm than at 355 and 266 nm. Copyright © 2011 John Wiley & Sons, Ltd.
Characterization of N‐terminal formaldehyde adducts to hemoglobin
Authors: Ospina Maria , Costin Alina , Barry Adrienne K. , Vesper Hubert W.
Published: March 2011

A procedure to prepare and purify adducts of formaldehyde (FA) to the N‐terminus of peptides was developed. FA‐VHLTPEEK and FA‐VLSPADK were produced with purities >95% upon incubation of the peptides with FA in phosphate‐buffered saline (PBS) at a pH level of 7.4. The peptides were purified by preparative liquid chromatography and were characterized by their retention times in liquid chromatography, their fragmentation patterns obtained by tandem mass spectrometry, and their accurate mass and nuclear magnetic resonance measurements. This is the first time an imidazolidone‐type structure has been reported for FA adducts. The same peptides were identified in tryptic digests of human hemoglobin incubated with FA at physiological conditions and in human hemoglobin specimens. These peptides are suitable for use as calibrators for the quantitative assessment of internal exposure to FA. Published in 2011 by John Wiley & Sons, Ltd.
A novel methyl migration to the phosphoryl group with the formation of cyclic aminoacylphosphoramidates in electrospray ionization tandem mass spectra of amino acid ester phosphoramidates of antiviral nucleosides
Authors: Gao Xiang , Zhu Gangtian , Zeng Zhiping , Chen Weizhu , Lin Zhiwei , Liu Yan , Xu Pengxiang , Zhao Yufen
Published: March 2011

The mass spectral behavior of amino acid methyl ester phosphoramidate derivatives have been investigated using electrospray ionization multistage mass spectrometry (ESI‐MSn) and moderate theoretical calculations at the B3LYP/6‐31G(d) level. A novel methyl group migration to the phosphoryl group with the formation of the intermediate cyclic aminoacylphosphoramidate was found. The proposed structures of the rearrangement ions were confirmed by high‐resolution tandem mass spectrometry. A possible mechanism involving the pentacoordinate phosphoric‐carboxylic phosphate anhydride was proposed, in which the metal ion coordination with the phosphoryl and carbonyl groups and the intrinsic properties of phosphoryl group might be the key factors responsible for this novel migration. Copyright © 2011 John Wiley & Sons, Ltd.
Structural features of polyacylated anthocyanins using matrix‐assisted laser desorption/ionization and electrospray ionization time‐of‐flight mass spectrometry
Authors: Kasai Hiroko F. , Saito Norio , Honda Toshio
Published: March 2011

In our continuing studies to isolate water‐soluble vacuolar pigments, we expect to elucidate more structural details using mass spectrometry (MS). Because of its sensitivity, only a small amount of pigment extracted from natural plants is required for MS measurement. Nuclear magnetic resonance is also a useful spectroscopic method for structural determination. In this study, two soft ionization techniques, electrospray ionization (ESI) and matrix‐assisted laser desorption/ionization (MALDI), on time‐of‐flight (TOF) mass spectrometers, were used to analyze five polyacylated anthocyanins with more than two aromatic acid molecules in the side chains. ESI is advantageous for the detection of individual molecular ions, while MALDI is essential for the detection of characteristic fragment ions originating from the anthocyanidin. Although 2,5‐dihydroxybenzoic acid (DHBA) is an effective matrix in MALDI‐TOFMS to obtain informative fragment ions of polyacylated anthocyanins, α‐cyano‐4‐hydroxycinnamic acid (CHCA) is the preferred matrix for the identification of aglycones. In particular, in measurements of polyacylated anthocyanins with two acylated glycoside chains, fragment ions originating from anthocyanidin can only be observed in MALDI‐TOFMS using CHCA as the matrix. Copyright © 2011 John Wiley & Sons, Ltd.
Fast determination of oleic acid in pork by flow injection analysis/mass spectrometry
Authors: Muñoz Rebeca , Vilaró Francisca , Eras Jordi , Estany Joan , Tor Marc
Published: March 2011

In some Mediterranean products such as olive oil or ham, oleic acid is the most abundant component of the total fat. Due to the large volume of trade in these products, it may be necessary to analyze oleic fatty acids in high numbers of samples in short periods of time. However, using classic lipid analysis techniques, it is not always possible to cope with these high demands. To solve this problem, a high‐throughput analytical method for oleic fatty acid quantification in pork is presented. The purpose of the method is to avoid liquid chromatography processes using a flow injection analysis (FIA) system based on electrospray ionization mass spectrometry. The use of pentadecanoic fatty acid as an internal standard overcame matrix effects. The oleic FIA technique could be used as a suitable method for discriminating carcass samples for selection and labeling by oleic acid content when large numbers of pork samples must be processed in a short period of time. Copyright © 2011 John Wiley & Sons, Ltd.
Soft‐sputtering of insulin films in argon‐cluster secondary ion mass spectrometry
Authors: Oshima Shohei , Kashihara Ippei , Moritani Kousuke , Inui Norio , Mochiji Kozo
Published: March 2011

In secondary ion mass spectrometry (SIMS) of organic substances, the dissociation of the sample molecules is crucial. We have developed SIMS equipment capable of bombardment, where the primary ions are argon cluster ions with kinetic energy per atom controllable down to 1 eV. We previously reported the detection of intact ions of insulin and cytochrome C using this equipment. In this paper, we present a detailed characterization of the emission of secondary ions from insulin, focusing on the difference in secondary ion yield between intact ions and fragment ions by varying the incident angle of the cluster ions. The emission intensity of the intact ions was changed drastically due to the exposed dosage and incident angle of the cluster ions in contrast to the fragment ions. We discuss these results based on the manner in which the argon‐cluster ions collide with the organic solid. Copyright © 2011 John Wiley & Sons, Ltd.
Structural modifications occurring in lipid A of Bordetella bronchiseptica clinical isolates as demonstrated by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry
Authors: Basheer Soorej M. , Guiso Nicole , Tirsoaga Alina , Caroff Martine , Novikov Alexey
Published: March 2011

Bordetella bronchiseptica is a respiratory pathogen in mammal species and its cell surface lipopolysaccharide‐endotoxin is a potent virulence factor. In order to better characterize the endotoxin structure to virulence relationships, we studied the lipid A structures of B. bronchiseptica isolates from human and rabbit origins as a function of their virulence phases. Matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF‐MS) has been widely used for the structural characterization of bacterial endotoxins and their lipid A moieties. This method combined with chemical analytical methods proved to be essential for the characterization of small samples and discrete but essential structural modifications. The occurrence of palmitate (C16) in the B. bronchiseptica lipid A structures is shown for the first time at two sites. Their presence was also demonstrated for the first time in correlation with the virulence phase of B. bronchiseptica clinical isolates. The recently identified glucosamine modifications of Bordetella lipids A are also reported in these isolates. Copyright © 2011 John Wiley & Sons, Ltd.
Practical considerations in analysing neuropeptides, calcitonin gene‐related peptide and vasoactive intestinal peptide, by nano‐electrospray ionisation and quadrupole time‐of‐flight mass spectrometry: monitoring multiple protonations
Authors: Abaye Daniel A. , Pullen Frank S. , Nielsen Birthe V.
Published: March 2011

We investigated the pre‐electrospray ionisation (pre‐ESI) factors; analyte concentration (1–2500 ng/mL), concentration of formic acid (FA) in the mobile phase (0.01, 0.1 and 1%), concentration of the organic modifier (acetonitrile 50–90%) and flow rate (<10 μL/min) on the number of multiple protonations and ESI response for two neuropeptides (of ~3.3 kDa molecular mass); calcitonin gene‐related peptide (CGRP) and vasoactive intestinal peptide (VIP). A pH of 3.23 (0.1% FA), nano‐flow rate range of 350–750 nL/min and acetonitrile concentration of 50% were optimum for both neuropeptides where the highest intensities were observed. An inverse relationship between decreasing flow rate and ESI response for both peptides was also observed. The quadruply charged ([M+4H]4+) ion was dominant for CGRP at all analyte concentrations, and also for VIP, but only at the higher analyte concentrations (250–2500 ng/mL); none of the [M+4H]4+, [M+5H]5+ or [M+6H]6+ ions were dominant at the lower concentrations. Linear correlations were obtained for the protonated states and ESI response at analyte concentrations (1–750 ng/mL). Acetonitrile concentration was critical; severe ion suppression was observed for VIP when the concentration of acetonitrile was ≥60%. Ion suppression was also observed for both peptides in an equimolar mixture, with the extent of ion suppression more severe for VIP. Our study concludes that it is important to monitor several protonated species when a single protonated state does not dominate, especially during label‐free peptide quantitations. Copyright © 2011 John Wiley & Sons, Ltd.
Sphingomyelin is more sensitively detectable as a negative ion than phosphatidylcholine: a matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometric study using 9‐aminoacridine (9‐AA) as matrix
Authors: Eibisch Mandy , Schiller Jürgen
Published: March 2011

Phospholipids (PLs) are increasingly analyzed by matrix‐assisted laser desorption/ionization time‐of‐flight (MALDI‐TOF) mass spectrometry (MS) and imaging MS. Different classes of PLs are preferentially detectable either as positive or negative ions depending on the charges of their headgroups. Sphingomyelin (SM) and phosphatidylcholine (PC) occur in virtually all biological samples and both are assumed to be detectable with the same sensitivity (in the positive ion mode) because their headgroups are identical. We will show here that the detectabilities of PC and SM depend on the matrix used. In the presence of 2,5‐dihydroxybenzoic acid (DHB) SM is more sensitively detectable in positive ion mode than PC while the use of 9‐aminoacridine (9‐AA) as matrix inverts the detectabilities. Our explanation is that the preferred generation of negative ions from SM if 9‐AA is used as matrix results in a reduced yield of positive ions. It will also be shown that this is not only valid if a simplified model system is investigated, but also if, for instance, extracts from human erythrocytes are investigated. It will also be outlined that this finding is particularly important in the context of imaging studies where no previous separation of the lipids of interest can be performed. Copyright © 2011 John Wiley & Sons, Ltd.
Multirobot exploration for search and rescue missions: A report on map building in RoboCupRescue 2009
Authors: Nagatani Keiji , Okada Yoshito , Tokunaga Naoki , Kiribayashi Seiga , Yoshida Kazuya , Ohno Kazunori , Takeuchi Eijiro , Tadokoro Satoshi , Akiyama Hidehisa , Noda Itsuki , Yoshida Tomoaki , Koyanagi Eiji
Published: March 2011

In the future, mobile robots may be able to assist rescue crews in search and rescue missions that take place in the dangerous environments that result from natural or man‐made disasters. In 2006, we launched a research project to develop mobile robots that can rapidly collect information in the initial stages of a disaster. One of our important objectives is three‐dimensional (3D) mapping, which can be a very useful tool for assisting rescue crews in strategizing rescue missions. To realize this 3D mapping, we identified five issues that we needed to address: (1) autonomous traversal of uneven terrain, (2) development of a system for the continuous acquisition of 3D data of the environment, (3) coverage path planning, (4) centralization of map data obtained by multiple robots, and (5) fusion of map data obtained by multiple robots. We solved each problem through our joint research. Each research institute in our group took charge of solving one of the above issues according to its area of expertise. We integrated these solutions to perform 3D mapping using our tracked vehicle, Kenaf. To validate our integrated autonomous 3D mapping system, we participated in RoboCupRescue 2009 and demonstrated our system using multiple robots on the RoboCupRescue field. In this paper, we introduce our mapping system and report the mapping results obtained at the RoboCupRescue event. © 2011 Wiley Periodicals, Inc.
Cable inspection robot for cable‐stayed bridges: Design, analysis, and application
Authors: Xu Fengyu , Wang Xingsong , Wang Lei
Published: March 2011

As the most important component of cable‐stayed bridges, cable safety has been of crucial public concern. In this paper, a new robot system for the inspection of stay cables is proposed. The robot not only replaces human workers in carrying out risky tasks in a hazardous environment but also increases operational efficiency by eliminating costly erection of scaffolding or dragging of winches. The designed robot is composed of two equally spaced modules, joined by connecting bars to form a closed hexagonal body that clasps the cable. For safe landing in case of an electrical interruption or malfunction, a gas damper with a slider‐crank mechanism is proposed to use up the extra energy generated by gravity when the robot slips down. To conserve energy, a landing method based on back electromotive force is introduced. Laboratory and field experiments verified that the robot can stably climb random inclined cables and land smoothly upon electrical malfunction. Finally, along with an application example, the vision inspection system based on charge‐coupled device cameras, operating modes of the robot, control methods, and feasibility are discussed in detail. The field applications on two cable‐stayed bridges indicate that such a low‐cost robot system can improve the efficiency of inspection operations and satisfy the requirements of actual cable inspection. © 2011 Wiley Periodicals, Inc.
The Effect of Post Fatigue Tensile Loading on Mechanical Properties and Failure Behaviour of Steel
Authors: Maity Joydeep , Kumar Shiv , Bhattacharyya Ashish
Published: March 2011

In this research work the early fatigue damage characteristics up to 50% of life has been investigated at near‐endurance stress amplitude in a medium carbon steel with hardened & tempered and normalized conditions by application of post fatigue tensile loading. During fatigue loading microvoids were generated at the interphase‐interface through vacancy clustering. Directional localized coalescence of these microvoids generated ‘void sheets’ in the normalized steel and ‘craters’ in the hardened & tempered steel. These defects acted as the potential sites for failure during post fatigue tensile loading deteriorating the mechanical properties. This was, therefore, clearly indicated that when a high tensile load is superimposed on near‐endurance fatigue loading, material may fail much earlier than its actual fatigue life. The normalized steel suffered from more reduction in ductility than the hardened & tempered steel indicating more susceptibility to fatigue damage.
Recent Developments and Mid‐ and Long‐Term CO2 Mitigation Projects in Ironmaking
Authors: Takeda Kanji , Anyashiki Takashi , Sato Takeshi , Oyama Nobuyuki , Watakabe Shiro , Sato Michitaka
Published: March 2011

CO2 mitigation and the stable supply of raw materials are two major issues for the steel industry. The Japanese steel industry has promoted short term developments and investments to comply with the Japan Iron and Steel Federation's voluntary action plan in parallel with developing plans for drastic CO2 mitigation programs toward the post Kyoto protocol period. This paper describes short‐term measures in the ironmaking field such as natural gas injection technology to the sintering bed and burden distribution control with coke mixed charging.

For mid and long term CO2 mitigation, the joint project, ‘Preparatory research work for the blast furnace based innovative ironmaking technologies’ was actively promoted by the New Energy and industrial Technology Development Organization (NEDO) from FY2006 to FY2008. Based on the enhancement of carbon ‐ CO2 reaction by close positioning of carbon and iron oxide/metallic iron, the production process and reaction mechanism in a blast furnace were studied for two innovative composites with iron oxide, metallic iron and carbon.

For development at a pilot plant scale, a new project, ‘Development of innovative ironmaking process using low cost iron ore and coal’ started in FY2009. Key technologies of the project are the production process and evaluation in a blast furnace of a hybrid composite of metallic iron and carbon, so called ‘Ferro‐coke’. This paper describes key technologies and recent developments of the project.
Recursive algebraic method of computing power system harmonics
Authors: Peiravi Ali , Ildarabadi Rahim
Published: March 2011

Ensuring power quality in power systems demands fast calculation of harmonics. In this paper, a recursive algebraic approach to the calculation of current transformer (CT)‐derived current signal frequency and harmonics is proposed that is based on a fast but accurate recursive algorithm whereby in any stage of sampling in a given cycle the variables are calculated on the basis of their values in the previous stage. Comparison with the discrete Fourier transform (DFT) approach shows the superiority of the proposed approach. It is shown that when the number of samples used in the DFT approach is increased, the results obtained approach those of the proposed recursive algebraic method. © 2011 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Delay‐dependent robust stability analysis for interval neural networks with time‐varying delay
Authors: Liu Fang , Wu Min , He Yong , Zhou Yicheng , Yokoyama Ryuichi
Published: March 2011

This article deals with the problem of robust stability for interval neural networks with time‐varying delay. By constructing an appropriate Lyapunov–Krasovskii functional, using the S‐procedure and taking the relationship among the time‐varying delay, its upper bound and their difference into account, some linear matrix inequality(LMI) ‐based delay‐dependent stability criteria are obtained without ignoring any terms in the derivative of the Lyapunov–Krasovskii functional. Finally, two numerical examples are given to demonstrate the effectiveness and benefits of the proposed method. © 2011 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
An investigation of flying capacitor converter for circuit integration
Authors: Kamaga Masamu , Sung Kyungmin , Sato Yukihiko , Ohashi Hiromichi
Published: March 2011

Output power density of power converters has been increased. In power converters with lower harmonic distortion and lower electromagnetic interference (EMI) which are required in many applications, bulky harmonic and EMI filters are usually connected. The volume of the harmonic filters can be reduced by increasing the switching frequency. However, higher switching frequency will cause larger switching loss and severe EMI. As another approach, there is possibility of intrinsic elimination of harmonics and EMI by introducing multilevel converters. However, as the number of levels increases, the number of circuit components will exceed the practical limit of the implementation. Thus, from a practical viewpoint, the main circuit and related circuits should be integrated. However, it has not been clarified which multilevel topology is suitable for circuit integration. In addition, the effectiveness in reducing total device loss considering chip size has not been evaluated. In this paper, the advantage of a flying capacitor multilevel topology for circuit integration is clarified by theoretical and experimental investigations. Also, the total device loss and chip size of the flying capacitor converter are estimated. © 2011 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Fabrication of a microelectromechanical system mirror array and its drive electrodes for low electrical interference in wavelength‐selective switches
Authors: Sakata Tomomi , Usui Mitsuo , Uchiyama Shingo , Shimoyama Nobuhiro , Kodate Junichi , Ishii Hiromu , Matsuura Tohru , Shimokawa Fusao , Sato Yasuhiro
Published: March 2011

This article describes the fabrication of a microelectromechanical system (MEMS) mirror array and mirror‐drive electrodes with high‐aspect‐ratio gold walls that reduce electrical interference in a wavelength‐selective switch (WSS). The MEMS mirror array, in which a lot of closely spaced adjacent mirrors are electrostatically operated, can be fabricated with a high yield by encapsulating the mirrors with an organic film that protects them from process damage. The gold walls with a high‐aspect ratio are formed in the narrow space between adjacent mirror‐drive electrodes by using thick‐multilevel interconnection technology. Because of these walls between adjacent electrodes, each MEMS mirror operates with low electrical interference. © 2011 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
A fast low‐density parity‐check code simulator based on compressed parity‐check matrices
Authors: Yau Shek F. , Wong Tan L. , Lau Francis C. M. , He Yejun
Published: March 2011

Low‐density parity‐check (LDPC) codes are very powerful error‐correction codes with capabilities approaching the Shannon's limits. In evaluating the error performance of an LDPC code, the computer simulation time taken becomes a primary concern when tens of millions of noise‐corrupted codewords are to be decoded, particularly for codes with very long lengths. In this paper, we propose modeling the parity‐check matrix of an LDPC code with compressed parity‐check matrices in the check‐node domain (CND) and in the bit‐node domain (BND), respectively. Based on the compressed parity‐check matrices, we created two message matrices, one in the CND and another in the BND, and two domain conversion matrices, one from CND to BND and another from BND to CND. With the proposed message matrices, the data used in the iterative LDPC decoding algorithm can be closely packed and stored within a small memory size. Consequently, such data can be mostly stored in the cache memory, reducing the need for the central processing unit to access the random access memory and hence improving the simulation time significantly. Furthermore, the messages in one domain can be easily converted to another domain with the use of the conversion matrices, facilitating the central processing unit to access and update the messages. Copyright © 2011 John Wiley & Sons, Ltd.
Personality assessment in snow leopards (Uncia uncia)
Authors: Marieke Cassia Gartner , David Powell
Published: March 2011

Knowledge of individual personality is a useful tool in animal husbandry and can be used effectively to improve welfare. This study assessed personality in snow leopards (Uncia uncia) by examining their reactions to six novel objects and comparing them to personality assessments based on a survey completed by zookeepers. The objectives were to determine whether these methods could detect differences in personality, including age and sex differences, and to assess whether the two methods yielded comparable results. Both keeper assessments and novel object tests identified age, sex, and individual differences in snow leopards. Five dimensions of personality were found based on keepers' ratings: Active/Vigilant, Curious/Playful, Calm/Self‐Assured, Timid/Anxious, and Friendly to Humans. The dimension Active/Vigilant was significantly positively correlated with the number of visits to the object, time spent locomoting, and time spent in exploratory behaviors. Curious/Playful was significantly positively correlated with the number of visits to the object, time spent locomoting, and time spent in exploratory behaviors. However, other dimensions (Calm/Self‐Assured, Friendly to Humans, and Timid/Anxious) did not correlate with novel‐object test variables and possible explanations for this are discussed. Thus, some of the traits and behaviors were correlated between assessment methods, showing the novel‐object test to be useful in assessing an animal's personality should a keeper be unable to, or to support a keeper's assessment. Zoo Biol 31: 151–165, 2012. © 2011 Wiley Periodicals, Inc.
CaPiTo: protocol stacks for services
Authors: Gao Han , Nielson Flemming , Nielson Hanne Riis
Published: March 2011

CaPiTo allows the modelling of service-oriented applications using process algebras at three levels of abstraction. The
abstract
level focuses on the key functionality of the services; the
plug-in
level shows how to obtain security using standardised protocol stacks; finally, the
concrete
level allows to consider how security is obtained using asymmetric and symmetric cryptographic primitives. The CaPiTo approach therefore caters for a variety of developers that need to cooperate on designing and implementing service-oriented applications. We show how to formally analyse CaPiTo specifications for ensuring the absence of security flaws. The method used is based on static analysis of the corresponding LySa specifications. We illustrate the development on two industrial case studies; one taken from the banking sector and the other a single sign-on protocol.
Adjuvant surgical therapy for patients with initially‐unresectable pancreatic cancer with long‐term favorable responses to chemotherapy
Authors: Kato Kentaro , Kondo Satoshi , Hirano Satoshi , Tanaka Eiichi , Shichinohe Toshiaki , Tsuchikawa Takahiro , Matsumoto Joe
Published: March 2011

Background

To evaluate the prognostic impact of surgical intervention for initially‐unresectable pancreatic ductal adenocarcinomas with long‐term favorable responses to chemotherapy.

Method

Twelve patients with initially‐unresectable pancreatic ductal carcinomas who underwent radical surgery after a favorable response to chemotherapy for six months or longer in principle were enrolled in this study. We retrospectively reviewed the charts of these 12 patients and performed a survival analysis.

Results

Initially, the included patients were unable to undergo resection secondary to locally‐advanced disease in eight patients and metastatic disease in four patients. The length of preoperative therapy was five to 44 months (median 12). The operative procedure included resection of the area initially involved by tumor and regional major vessels. The postoperative mortality and morbidity rates were 0% for patients with locally‐advanced disease and 50% in those with metastatic disease. R0 resection was achieved in nine patients (75%) and pathological CR was seen in one patient. Estimated overall five‐year survival from initial therapy was 50.0%. The survival rate (0% at 5 years) of the four patients with metastatic disease as the cause of initial unresectability was significantly worse than that (100% at 5 years) of the eight patients with locally‐advanced disease (p = 0.0014).

Conclusion

Surgical intervention should be considered for patients with initially‐unresectable pancreatic cancers who demonstrate long‐term favorable responses to chemotherapy. R0 resection may significantly contribute to cure, especially in patients with initially locally‐advanced disease. Large cohort prospective studies will be necessary to demonstrate the efficacy of this strategy.
Iliopsoas Impingement: A Newly Identified Cause of Labral Pathology in the Hip
Authors: Domb Benjamin G. , Shindle Michael K. , McArthur Benjamin , Voos James E. , Magennis Erin M. , Kelly Bryan T.
Published: March 2011

Labral tears typically occur anterosuperiorly in association with femoroacetabular impingement or dysplasia. Less commonly, labral pathology may occur in an atypical direct anterior location adjacent to the iliopsoas tendon in the absence of bony abnormalities. We hypothesize that this pattern of injury is related to compression or traction on the anterior capsulo-labral complex by the iliopsoas tendon where it crosses the acetabular rim. In a retrospective review of prospectively collected data, we identified 25 patients that underwent isolated, primary, unilateral iliopsoas release and presented for at least 1 year follow-up (mean 21 months). Pre-operative demographics, clinical presentation, intra-operative findings, and outcome questionnaires were analyzed. The injury was treated with a tenotomy of the iliopsoas tendon at the level of the joint line and either labral debridement or repair. Mean post-operative outcome scores were 87.17, 92.46, and 78.8 for the modified Harris Hip Score, activities of daily living Hip Outcome Score, and sports-related score, respectively. The atypical labral injury identified in this study appears to represent a distinct pathological entity, psoas impingement, with an etiology which has not been previously described.
Study on Free Lipase‐Catalyzed Ethanolysis for Biodiesel Preparation in an Oil/Water Biphasic System
Authors: Ren Hongjie , Du Wei , Lv Liangliang , Liu Dehua
Published: March 2011

Using free lipase as the catalyst for biodiesel production has drawn increasing attention in recent years due to its advantages of lower cost and faster reaction rate compared to immobilized lipase. Our previous study showed that free lipase NS81006 could effectively catalyze the methanolysis of renewable oil. Ethanol, derived from renewable biomass, has a greater potential for biodiesel production. In this paper, ethanol was explored for the first time as the acyl acceptor for free lipase‐mediated biodiesel preparation. The effect of stirring rate, water content, molar ratio of ethanol to oil and ethanol adding strategy was investigated systematically during the process of free lipase NS81006‐catalyzed ethanolysis. An ethyl ester yield of 90% was obtained under the optimized conditions. Further study showed that the free lipase could be repeatedly used by simple separation of the water phase from the oil phase and there was no obvious loss in lipase activity after five repeated uses.
Compartmentation of NAD+‐dependent signalling
Authors: Koch-Nolte Friedrich , Fischer Stefan , Haag Friedrich , Ziegler Mathias
Published: March 2011

NAD+ plays central roles in energy metabolism as redox carrier. Recent research has identified important signalling functions of NAD+ that involve its consumption. Although NAD+ is synthesized mainly in the cytosol, nucleus and mitochondria, it has been detected also in vesicular and extracellular compartments. Three protein families that consume NAD+ in signalling reactions have been characterized on a molecular level: ADP‐ribosyltransferases (ARTs), Sirtuins (SIRTs), and NAD+ glycohydrolases (NADases). Members of these families serve important regulatory functions in various cellular compartments, e.g., by linking the cellular energy state to gene expression in the nucleus, by regulating nitrogen metabolism in mitochondria, and by sensing tissue damage in the extracellular compartment. Distinct NAD+ pools may be crucial for these processes. Here, we review the current knowledge about the compartmentation and biochemistry of NAD+‐converting enzymes that control NAD+ signalling.
Arsenic affects expression and processing of amyloid precursor protein (APP) in primary neuronal cells overexpressing the Swedish mutation of human APP
Authors: Zarazúa Sergio , Bürger Susanne , Delgado Juan M. , Jiménez‐Capdeville Maria E. , Schliebs Reinhard
Published: March 2011

Arsenic poisoning due to contaminated water and soil, mining waste, glass manufacture, select agrochemicals, as well as sea food, affects millions of people world wide. Recently, an involvement of arsenic in Alzheimer's disease (AD) has been hypothesized (Gong and O'Bryant, 2010). The present study stresses the hypothesis whether sodium arsenite, and its main metabolite, dimethylarsinic acid (DMA), may affect expression and processing of the amyloid precursor protein (APP), using the cholinergic cell line SN56.B5.G4 and primary neuronal cells overexpressing the Swedish mutation of APP, as experimental approaches.

Exposure of cholinergic SN56.B5.G4 cells with either sodium arsenite or DMA decreased cell viability in a concentration‐ and exposure‐time dependent manner, and affected the activities of the cholinergic enzymes acetylcholinesterase and choline acetyltransferase. Both sodium arsenite and DMA exposure of SN56.B5.G4 cells resulted in enhanced level of APP, and sAPP in the membrane and cytosolic fractions, respectively. To reveal any effect of arsenic on APP processing, the amounts of APP cleavage products, sAPPβ, and β‐amyloid (Aβ) peptides, released into the culture medium of primary neuronal cells derived from transgenic Tg2576 mice, were assessed by ELISA. Following exposure of neuronal cells by sodium arsenite for 12 h, the membrane‐bound APP level was enhanced, the amount of sAPPβ released into the culture medium was slightly higher, while the levels of Aβ peptides in the culture medium were considerably lower as compared to that assayed in the absence of any drug. The sodium arsenite‐induced reduction of Aβ formation suggests an inhibition of the APP γ‐cleavage step by arsenite. In contrast, DMA exposure of neuronal cells considerably increased formation of Aβ and sAPPβ, accompanied by enhanced membrane APP level. The DMA‐induced changes in APP processing may be the result of the enhanced APP expression. Alternatively, increased Aβ production may also be due to stimulation of caspase activity by arsenic compounds, or failure in Aβ degradation.

In summary, the present report clearly demonstrates that sodium arsenite and DMA affect processing of APP in vitro.
Identification for Chaos and Subharmonic Responses in Coupled Forced Duffing's Oscillators
Authors: Jeng J.-D. , Kang Y. , Chang Y.-P.
Published: March 2011

In this paper, a response integral quantity method is proposed. This technique provides a quantitative characterization of system responses and can assist the role of the traditional stroboscopic technique (Poincaré section method) in observing bifurcations and chaos of the nonlinear oscillators. We numerically analyze and identify the chaos and subharmonic responses in the forced coupled Duffing's oscillators in which we find that chaotic behaviors and high-order subharmonic responses exist. Due to the signal response contamination of system, it is difficult to identify the high-order responses of the subharmonic motion because of the sampling points on Poincaré map being very close to each other. Even the system responses are subject to misjudgments. The simulation results, however, show that the highorder subharmonic and chaotic responses and their bifurcations can be observed effectively.
The Method of Fundamental Solutions for Water-Wave Diffraction by Thin Porous Breakwater
Authors: Tsai C. H. , Young D. L.
Published: March 2011

The method of fundamental solutions (MFS) and domain decomposition method (DDM) are employed to solve the water-wave diffraction by a thin porous vertical breakwater of semi-infinite extent. Based on the linearized theory of water waves, the problem can be reduced to a boundary value problem with degenerate boundary. In contrast to other mesh dependent numerical method, the MFS is easier and more efficient to handle degenerate boundary value problems. Various incident wave angles and porous parameters are included to validate the power of the proposed numerical scheme. The present results demonstrate the MFS is sufficiently accurate and feasible to be used to predict water-wave diffraction by a thin permeable breakwater by comparing with literature.