bluuebunny/crossref_metadata_2025_split huggingface dataset:
Disturbance rejection in a class of adaptive control laws for distributed parameter systems
Authors: Kim Jun Y. , Bentsman Joseph 
Published: April 2008

AbstractA recently introduced class of the well‐posed error systems and the corresponding robust model reference adaptive control laws for the systems represented by the parabolic or the hyperbolic partial differential equations (PDEs) with the spatially varying parameters and a distributed sensing and actuation is extended to encompass the disturbance rejection capability. The disturbance is modeled as a space–time‐varying signal generated by a parabolic PDE with the known parameters, a spatially varying time‐invariant signal, and a space–time‐varying signal with the known time variation. The case of the time‐invariant disturbance model is shown to lead to a distributed adaptive PI control law, thereby making a well‐posed connection to the classical finite‐dimensional control structures. The numerical simulations indicate that the control laws proposed are robust with respect to the plant/reference model as well as the disturbance/disturbance observer mismatch in the boundary conditions. Copyright © 2008 John Wiley & Sons, Ltd.
Extended high‐frequency audiometry and noise induced hearing loss in cement workers
Authors: Somma Giuseppina , Pietroiusti Antonio , Magrini Andrea , Coppeta Luca , Ancona Carla , Gardi Stefano , Messina Marco , Bergamaschi Antonio 
Published: April 2008

AbstractBackgroundIt has been suggested that extended high‐frequency audiometry (EHFA) might be more sensitive than conventional audiometry in detecting early signs of hearing impairment. However, this technique has not been adequately tested in an occupational environment. We therefore investigated the usefulness of this method in noise‐exposed workers.MethodsWe compared conventional frequency audiometry (0.25–8 kHz) and EHFA (9–18 kHz) in 184 noise‐exposed and 98 non‐noise‐exposed workers.ResultsBoth methods showed significantly higher threshold levels (P < 0.05) in noise‐exposed workers for most of the tested frequencies; however, the differences were more marked for EHFA, especially in young exposed workers. Significant differences in the EHF range were detected also in the subgroup of noise‐exposed workers with normal findings at conventional audiometry. Stepwise regression analysis showed that in 21‐ to 40‐year‐old workers the noise effect was largely predominant at both conventional audiometry and EHFA, whereas in older subjects the noise effect was predominant up to 6 kHz frequency, the effect of age being significantly greater at higher frequencies.ConclusionsThese data indicate that EHFA is more sensitive than conventional audiometry in detecting noise induced hearing loss. However, hearing loss in the EHF range seems an age‐dependent phenomenon with progression into the lower speech range frequencies with increasing age. These changes seem to be accentuated in the early years by noise exposure, suggesting that EHFA could represent a useful preventive measure in young exposed workers. Am. J. Ind. Med. 51:452–462, 2008. © 2008 Wiley‐Liss, Inc.
Homogeneous palladium catalyst for the oxidative carbonylation of bisphenol A to polycarbonate in propylene carbonate
Authors: Okamoto Masaya , Ishii Hirotoshi , Sugiyama Jun‐Ichi 
Published: April 2008

AbstractPolycarbonates (PCs) were prepared in a propylene carbonate solvent by the oxidative carbonylation of bisphenol A with Pd/bithienyl complexes, Pd/bipyridyl complexes, and PdC σ‐bonded complexes for comparison as homogeneous Pd catalysts. With the Pd/bipyridyl complexes, the 6,6′‐disubstituted 2,2′‐bipyridyl ligand showed a stronger substituent effect than the 2,2′‐bipyridyl ligand, which lacked substituents at the 6,6′ positions. With the Pd/bithienyl complexes, however, the substituent effect was not seen. The Pd/bithienyl complexes, which lacked substituents at the 5,5′ positions, gave a PC yield that was the same as the yield of those that had substituents at the 5,5′ positions. The combination of the PdC σ‐bonded complexes and an inorganoredox cocatalyst showed a PC polymerization behavior that was different from the other two types of complexes. When Co(OAc)2·4H2O was used as the inorganoredox cocatalyst, all of the PdC σ‐bonded complexes gave a good PC yield. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
New organosoluble and thermally stable poly(urea‐imide)s prepared from one‐pot polyaddition reactions
Authors: Behniafar Hossein , Amrai Mehrtaj 
Published: April 2008

AbstractA new class of aromatic poly(urea‐imide)s having biphenylene pendant group was prepared by the diphenyl azidophosphate (DPAP) activated one‐pot polyaddition reaction of a preformed imide ring‐containing dicarboxylic acid, 4‐p‐biphenyl‐2,6‐bis(4‐trimellitimidophenyl)pyridine (1) with various aromatic diamines. A model compound was also synthesized by the reaction of diimide‐dicarboxylic acid 1 with two mole equivalents of aniline. In this direct method the polymers were prepared by polyaddition reactions of the in situ‐formed diisocyanate with the aromatic diamines. The inherent viscosities of the polymers were measured in the range of 0.11–0.15 dL g−1. The ultraviolet λmax values of the poly(urea‐imide)s were also determined. Furthermore, crystallinity of the resultant polymers was evaluated by wide‐angle X‐ray diffraction method, and they exhibited nearly a noncrystalline nature. All of the resulting polymers exhibited excellent solubility in common polar solvents. The glass transition temperatures of the polymers determined by DSC thermograms were in the range 241–272°C. The temperatures at 10% weight loss from their TGA curves were found to be in the range 406–437°C in nitrogen. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
The influence of transformations on the h‐index and the g‐index
Authors: Egghe L. 
Published: April 2008

AbstractIn a previous article, we introduced a general transformation on sources and one on items in an arbitrary information production process (IPP). In this article, we investigate the influence of these transformations on the h‐index and on the g‐index. General formulae that describe this influence are presented. These are applied to the case that the size‐frequency function is Lotkaian (i.e., is a decreasing power function). We further show that the h‐index of the transformed IPP belongs to the interval bounded by the two transformations of the h‐index of the original IPP, and we also show that this property is not true for the g‐index.
Social networks, gender, and friending: An analysis of MySpace member profiles
Authors: Thelwall Mike 
Published: April 2008

AbstractIn 2007, the social networking Web site MySpace apparently overthrew Google as the most visited Web site for U.S. Web users. If this heralds a new era of widespread online social networking, then it is important to investigate user behaviour and attributes. Although there has been some research into social networking already, basic demographic data is essential to set previous results in a wider context and to give insights to researchers, marketers and developers. In this article, the demographics of MySpace members are explored through data extracted from two samples of 15,043 and 7,627 member profiles. The median declared age of users was surprisingly high at 21, with a small majority of females. The analysis confirmed some previously reported findings and conjectures about social networking, for example, that female members tend to be more interested in friendship and males more interested in dating. In addition, there was some evidence of three different friending dynamics, oriented towards close friends, acquaintances, or strangers. Perhaps unsurprisingly, female and younger members had more friends than others, and females were more likely to maintain private profiles, but both males and females seemed to prefer female friends, with this tendency more marked in females for their closest friend. The typical MySpace user is apparently female, 21, single, with a public profile, interested in online friendship and logging on weekly to engage with a mixed list of mainly female “friends” who are predominantly acquaintances.
Luminescent Alkynylplatinum(II) Complexes of 2,6‐Bis(N‐alkylbenzimidazol‐2′‐yl)pyridine‐Type Ligands with Ready Tunability of the Nature of the Emissive States by Solvent and Electronic Property Modulation
Authors: Tam Anthony Yiu‐Yan , Lam Wai Han , Wong Keith Man‐Chung , Zhu Nianyong , Yam Vivian Wing‐Wah 
Published: April 2008

AbstractA new class of luminescent alkynylplatinum(II) complexes of tridentate bis(N‐alkylbenzimidazol‐2′‐yl)pyridines (bzimpy), [Pt(R,R′‐bzimpy)(CCR′′)]X (X=PF6, OTf), and one of their chloro precursor complexes, [Pt(R,R′‐bzimpy)Cl]PF6, have been synthesized and characterized; one of the alkynyl complexes has also been structurally characterized by X‐ray crystallography. Electrochemical studies showed that the oxidation wave is alkynyl ligand‐based in nature with some mixing of the metal center‐based contribution, whereas the two quasi‐reversible reduction couples are mainly bzimpy‐based reductions. The electronic absorption and luminescence properties of the complexes have also been investigated. In solution, the high‐energy and intense absorption bands are assigned as the π–π* intraligand (IL) transitions of the bzimpy and alkynyl ligands, whereas the low‐energy and moderately intense absorptions are assigned to an admixture of metal‐to‐ligand charge‐transfer (MLCT) (dπ(Pt)→π*(R,R′‐bzimpy)) and ligand‐to‐ligand charge‐transfer (LLCT) (π(CCR′′)→π*(R,R′‐bzimpy)) transitions. Upon variation of the electronic effects of the arylalkynyl ligands, vibronic‐structured or structureless emission bands, originating from triplet metal‐perturbed intraligand (IL) or an admixture of triplet metal‐to‐ligand charge‐transfer (MLCT) and ligand‐to‐ligand charge‐transfer (LLCT) excited states respectively, were observed in solution. Interestingly, two of the complexes showed a dual luminescence that was sensitive to the polarity of the solvents. Upon cooling from 298 K to 155 K, drastic color, UV/Vis, and luminescence changes were observed in a butyronitrile solution of 1, and were ascribed to the formation of aggregate species through Pt⋅⋅⋅Pt and π–π stacking interactions. DFT and time‐dependent DFT (TD‐DFT) calculations have been performed to verify and elucidate the results of the electrochemical and photophysical properties.
Folding of Coordination Polymers into Double‐Stranded Helical Organization
Authors: Kim Ho‐Joong , Lee Eunji , Kim Min Gyu , Kim Min‐Cheol , Lee Myongsoo , Sim Eunji 
Published: April 2008

AbstractSelf‐assembling coordination polymers based on PdII and CuII metal ions were prepared from complexation of a bent‐shaped bispyridine ligand and a corresponding transition metal. These coordination polymers were observed to self‐assemble into supramolecular structures that differ significantly depending on the coordination geometry of the metal center. The polymer based on PdII self‐assembles into a layer structure formed by bridging bispyridine ligands connected in a trans‐position of the square‐planar coordination geometry of metal center. In contrast, the polymer based on CuII adopts a double‐helical conformation with regular grooves, driven by interstranded, copper–chloride dimeric interaction. The double‐stranded helical organization is further confirmed by structure optimization from density functional theory with aromatic framework, showing that the optimized double‐helical structure is energetically favorable and consistent with the experimental results. These results demonstrate that weak metal–ligand bridging interactions can provide a useful strategy to construct stable double‐stranded helical nanotubes.
Reduction of phosphorylated histone H3 serine 10 and serine 28 cell cycle marker intensities after DNA damage
Authors: Ozawa Kazuo 
Published: April 2008

AbstractPhosphorylated histone H3 at serine 10 and serine 28 (H3Ser10 and H3Ser28) have been recognized as cell cycle markers to evaluate the late‐G2/M status of cell and tissue samples. I report about the reduction phenomena of H3Ser10 and Ser28 phosphorylation (H3Ser10P and 28P) at the late‐G2 through M cell cycle phases in association with DNA damage caused by hydrogen peroxide (H2O2). The levels of H3Ser10P and Ser28P decreased between 15 and 60 min after H2O2 addition in an inverse correlation manner with H2AX Ser139 phosphorylation (γH2AX). Experiments using wortmannin suggested that the reduction events of H3Ser10P/28P are under the control of phosphatidylinositol 3‐kinase‐like kinases. Fluorescence microscopic observation showed that H3Ser10 and Ser28 on telomeric portions of condensed M‐phase chromosomes retained their strongly phosphorylated status even after 60 min of H2O2 treatment. In addition, these chromosome parts were poorly γH2AX positive showing mutually exclusive distribution patterns between H3Ser10P/28P and γH2AX. Considering these data, I hypothesize that the reduction of the H3Ser10P/28P is a part of the DNA damage response processes. It is advisable to pay careful attention to these phenomena at the time of designing cell cycle assay protocols with H3Ser10P or Ser28P mitosis markers when DNA damaging process is expected to occur. © 2008 International Society for Advancement of Cytometry
Contrasting cytoskeletal regulation of MHC class II peptide presentation by human B cells or dendritic cells
Authors: Delaguillaumie Alix , Marin‐Esteban Viviana , Setterblad Niclas , Leh Laurence Jeanson , Assier Eric , Gelin Catherine , Charron Dominique , Galy Anne , Mooney Nuala 
Published: April 2008

AbstractMHC class II‐mediated antigen presentation by B lymphocytes or dendritic cells (DC) initiates CD4+ T lymphocyte activation. In B lymphocytes, MHC class II peptide presentation has been characterised by recruitment of MHC class II, F‐actin and lipid rafts to the B cell–T cell immunological synapse. We now show that MHC class II engagement in B lymphocytes induced lipid raft‐independent Rho and Rac activation and that inhibition of either Rho‐GTPase activation or actin polymerisation in the B cell abrogated T cell activation without altering B cell–T cell conjugate formation. Short‐hairpin RNA studies excluded a role for the Cdc42 effector Wiskott–Aldrich syndrome protein. In contrast, antigen presentation by DC was Rho‐GTPase‐independent although actin was recruited to the DC–T cell interaction site. Moreover, actin depolymerisation in the DC significantly increased T cell activation without altering the number of DC–T cell conjugates. Finally we show that stable recruitment of HLA‐DR to the site of the immunological synapse is not a uniform observation in DC and demonstrate reduced HLA‐DR expression at the site of microtubule organising centre polarization. Therefore although actin accumulates in DC and B lymphocytes at the immunological synapse with antigen‐specific T lymphocytes, this does not reflect comparable functional roles of their actin cytoskeletons in antigen presentation.
Microcapillary electrophoresis chips utilizing controllable micro‐lens structures and buried optical fibers for on‐line optical detection
Authors: Hsiung Suz‐Kai , Lee Chun‐Hong , Lee Gwo‐Bin 
Published: April 2008

AbstractIn this study, a new design of a controllable micro‐lens structure capable of the enhancement of LIF detection system has been demonstrated, which can be further integrated with buried optical fibers on a micro‐CE chip for sample separation and detection. Two pneumatic side‐chambers were placed between a micro‐CE channel and an optical fiber channel. The intervals between the side‐chamber and the microchannel were used to form two surfaces of the controllable micro‐lens structure. Deformations of the two surfaces can be generated after pressurized index‐matching fluid was injected into the pneumatic side‐chambers. The side‐chambers can be deflected as a double convex lens to focus both the excitation light source and the fluorescent emission signal. The profile and the focal length of the micro‐lens structure can be actively adjusted by applying different liquid pressures so that biosamples with a low concentration can be detected. Using low‐cost polymeric materials such as polydimethylsiloxane, rapid and reliable fabrication techniques involving standard lithography and replication process was employed for the formation of the proposed chip device. Experimental results revealed the controllable micro‐lens structure can be successfully deformed as a convex lens to focus the laser light source and the collected fluorescence signal can be enhanced accordingly. The power amplitude of excitation laser light can be enhanced by 5.4‐fold. FITC dye and DNA markers were then utilized for micro‐CE testing. The results indicated that the signal amplitude could be enhanced 2.5‐fold when compared to the case without the activation of the micro‐lens. According to the experimental results, the developed device has a great potential to be integrated with other microfluidic devices for further biomedical applications.
Coupling a microchip with electrospray ionization quadrupole time‐of‐flight mass spectrometer for peptide separation and identification
Authors: Li Hai‐Fang , Liu Jiangjiang , Cai Zongwei , Lin Jin‐Ming 
Published: April 2008

AbstractThe present study reports a simple method of coupling a glass microchip to an electrospray ionization (ESI) quadrupole time‐of‐flight mass spectrometer (QTOF‐MS) for separation and identification of peptides. A sheath‐flow electrospray interface was constructed based on attaching a short fused‐silica capillary to the microchip. The dead volume at the interface was effectively reduced by wet etching an approximate flat‐bottom capillary insertion channel coaxial to the end of separation microchannel and using a wire‐controlled epoxy‐blocking attachment method. The makeup liquid and neb gas were coaxially pumped through two stainless‐steel tees to maintain a stable and efficient electrospray. The coupled microchip/ESI‐QTOF‐MS system was successfully used to carry out electrophoresis separation of peptides and ESI‐QTOF‐MS identification.
Sensitive, label‐free protein assay using 1‐ethyl‐3‐methylimidazolium tetrafluoroborate‐supported microchip electrophoresis with laser‐induced fluorescence detection
Authors: Xu Yuanhong , Li Jing , Wang Erkang 
Published: April 2008

AbstractBased on the dimer–monomer equilibrium movement of the fluorescent dye Pyronin Y (PY), a rapid, simple, highly sensitive, label‐free method for protein detection was developed by microchip electrophoresis with LIF detection. PY formed a nonfluorescent dimer induced by the premicellar aggregation of an anionic surfactant, SDS, however, the fluorescence intensity of the system increased dramatically when proteins such as BSA, bovine hemoglobin, cytochrome c, and trypsin were added to the solution due to the transition of dimer to fluorescent monomer. Furthermore, 1‐ethyl‐3‐methylimidazolium tetrafluoroborate (EMImBF4) instead of PBS was applied as running buffers in microchip electrophoresis. Due to the excellent properties of EMImBF4, not only nonspecific protein adsorption was more efficiently suppressed, but also approximately ten‐fold higher fluorescence intensity enhancement was obtained than that using PBS. Under the optimal conditions, detection limits for BSA, bovine hemoglobin, cytochrome c, and trypsin were 1.00×10−6, 2×10−6, 7×10−7, and 5×10−7 mg/mL, respectively. Thus, without covalent modification of the protein, a protein assay method with high sensitivity was achieved on microchips.
Mobile communication array processing based on radial‐basis function neural network and fractional lower order statistics
Authors: Zha Daifeng 
Published: April 2008

AbstractAlpha stable distribution is better for modelling impulsive noises than Gaussian distribution in signal processing. This class of process has no close form of probability density function and finite second order moments. This paper addresses the direction of arrival estimation and beamforming problems of mobile communication system with linear antenna arrays in high impulsive noise environment. In order to reduce the computational complexity, the problems of DOA and beamforming are approached as a nonlinear mapping that can be modelled using a suitable radial‐basis function neural network (RBFNN). This paper also proposes the application of a three–layer RBFNN to perform the DOA estimation and beamforming in presence of alpha stable distribution noises. The performance of the network is compared to that of the fractional lower order statistics based algorithms. Simulations show that the RBFNN is appropriate to approach the DOA estimation and beamforming. At the same time, the RBFNN substantially reduces the computation complexity. Copyright © 2008 John Wiley & Sons, Ltd.
CLUMPHAP: a simple tool for performing haplotype‐based association analysis
Authors: Knight Jo , Curtis David , Sham Pak C. 
Published: April 2008

AbstractThe completion of the HapMap Project and the development of high‐throughput single nucleotide polymorphism genotyping technologies have greatly enhanced the prospects of identifying and characterizing the genetic variants that influence complex traits. In principle, association analysis of haplotypes rather than single nucleotide polymorphisms may better capture an underlying causal variant, but the multiple haplotypes can lead to reduced statistical power due to the testing of (and need to correct for) a large number of haplotypes. This paper presents a novel method based on clustering similar haplotypes to address this issue. The method, implemented in the CLUMPHAP program, is an extension of the CLUMP program designed for the analysis of multi‐allelic markers (Sham and Curtis [1995] Ann. Hum. Genet. 59(Pt1):97–105). CLUMPHAP performs a hierarchical clustering of the haplotypes and then computes the χ2 statistic between each haplotype cluster and disease; the statistical significance of the largest of the χ2 statistics is obtained by permutation testing. A significant result suggests that the presence of a disease‐causing variant in the haplotype cluster is over‐represented in cases. Using simulation studies, we have compared CLUMPHAP and more widely used approaches in terms of their statistical power to identify an untyped susceptibility locus. Our results show that CLUMPHAP tends to have greater power than the omnibus haplotype test and is comparable in power to multiple regression locus‐coding approaches. Genet. Epidemiol. 2008. © 2008 Wiley‐Liss, Inc.
Electrospinning fabrication of high‐trackable catheter tip with gradually graded or gradient flexibility
Authors: Matsuda Takehisa , Kawahara Daigo 
Published: April 2008

AbstractIncreasing demand for a flexible catheter tip exists in the rapidly growing fields of vascular and interventional radiology. This article describes a fabrication technology producing a catheter tip with gradually graded or gradient flexibility. Based on deflection mechanics of a tubular construct, three models were incorporated into structural designs. The models included graded wall thickness, tapered shape, or graded Young's moduli. Electrospinning using elastomeric polymer [poly(L‐lactide‐co‐ε‐caprolactone), polyurethane] solutions on a transversely and rotationally moving mandrel enabled preparation of three prototype tubular tips by either regio‐specific control of wall thickness, tapered mandrel, or regiospecific deposition of polyurethanes with different Young's moduli. All prototype tips exhibited high flexibility at tip ends, as verified using a bifurcated vessel model. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008