bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation of the synthetic route to pepstatin analogues by SPPS using O‐protected and O‐unprotected statine as building blocks
Authors: Cadicamo Cosimo D. , Asante Vivian , Abu Ammar Morhaf , Borelli Claudia , Korting Hans C. , Koksch Beate
Published: February 2009

The synthetic route to pepstatin derivatives by a solid phase peptide synthesis using either O‐protected or O‐unprotected statine as a building block has been investigated. Statine was prepared according to a modified literature procedure, whereas protection of its 3‐hydroxyl moiety using tert‐butyldimethylsilylchloride (TBSCl) provided the novel O‐TBS‐protected statine building block. The O‐tert‐butyldimethylsilyl (TBS)‐protected statine approach provides an improved synthetic strategy for the preparation of statine‐containing peptides as demonstrated by the synthesis of the pepstatin analogue iva‐Val‐Leu‐Sta‐Ala‐Sta. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd.
Production and isotope labeling of antimicrobial peptides in Escherichia coli by means of a novel fusion partner that enables high‐yield insoluble expression and fast purification
Authors: Vidovic Verica , Prongidi‐Fix Lydia , Bechinger Burkhard , Werten Sebastiaan
Published: February 2009

A method is presented that allows efficient production of antimicrobial peptides in bacteria by means of fusion to the histone fold domain of the human transcription factor TAF12. This small fusion partner drives high‐level expression of peptides and leads to their accumulation in an entirely insoluble form, thereby eliminating toxicity to the host. Using the antimicrobial peptide LAH4 as an example, we demonstrate that neither affinity purification of the TAF12 fusion protein nor initial solubilization of inclusion bodies in denaturing buffers is required. Instead, crude insoluble material from bacteria is directly dissolved in formic acid for immediate release of the peptide through chemical cleavage at a unique Asp‐Pro site. This is followed by purification to homogeneity in a single chromatographic step. Because of the elevated expression levels of the histone fold domain and its small size (8 kDa), this straightforward purification scheme produces yields in excess of 10 mg active peptide per liter of culture. We demonstrate that TAF12 fusion allows expression of a wide range of antimicrobial peptides as well as efficient isotope labeling for NMR studies. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd.
Synthesis of hepcidin derivatives in order to develop standards for immune adsorption method
Authors: Balogh Ádám , Horváti Kata , Mező Gábor , Derzbach László , Szebeni Beáta , Nagy Lajos , Prechl József , Vásárhelyi Barna , Hudecz Ferenc , Bősze Szilvia
Published: February 2009

MeCN, acetonitrile; ECL, enhanced chemiluminescence; EDT, 1,2‐ethanedithiole; HEPC12‐A, rabbit anti‐human hepcidin IgG, affinity purified; HEPC13‐A, rabbit anti‐mouse/human hepcidin IgG, affinity purified; HEPC61‐P, human hepcidin‐25 control/blocking synthetic peptide; HRP, horseradish peroxidase; IL‐6, interleukin‐6; KLH, keyhole limpet hemocyanin; LEAP, liver‐expressed antimicrobial peptide; NEM, N‐ethylmaleimide; NMP, N‐methyl‐pirrolidone; PBS, phosphate buffered saline; PVDF, polyvinylidene difluoride; SELDI‐TOF‐MS, surface‐enhanced laser desorption ionization–time‐of‐flight mass spectrometry; TMB, tetramethylbenzidin; TNF‐α, tumor necrosis factor‐α Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd.
Stratified structure of anodically formed mesoporous silica
Authors: Chazalviel Jean‐Noël , Cortès Robert , Maroun Fouad , Ozanam François
Published: February 2009

Films of mesoporous silica are formed on silicon single crystal by high‐potential anodisation in neutral fluoride electrolyte. The films formed at 7–15 V potential exhibit a bright coloured aspect, characteristic of thin films of submicrometer thickness with flat parallel surfaces. SEM examination of cleaved profiles and X‐ray reflectivity curves point to a stratified structure of these films on the nanometric scale. The stacking period, on the order of 10 nm, is an increasing function of the preparation potential. This structure is clearly related to the well‐known oscillatory electrochemical behaviour observed above 3 V potential in the silicon/acidic‐fluoride‐electrolyte system. These observations confirm the idea that this oscillatory behaviour is accompanied by significant changes in the oxide morphology, namely a modulation of the porosity. The surviving of this oscillatory behaviour even though the interface is buried below a stack of several tens of oxide layers is a challenging observation for the theoretical modelling of the oscillation mechanism. We propose that periodic cracking of the inner oxide film may originate from a tensile stress due to electrochemically‐induced desiccation near the silicon/oxide interface. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photo‐electrochemical etching of macro‐pores in silicon with grooves as etch seeds
Authors: Astrova E. V. , Nechitailov A. A. , Tolmachev V. A. , Melnikov V. A. , Perova T. S.
Published: February 2009

Role of linear nucleation centres (surface grooves) in formation of macro‐pores has been studied for n‐type Si. It has been found that linear nucleation centres, contrary to the case of point nucleation pits, initiate formation of semi‐regular pore pattern: along the grooves the pores are arranged randomly as a result of self organization process, across the grooves they follow the prescribed period a. The average distance between the pores along a groove line depends on a, and decreases as a increases. At the optimal value of etching current density and seed period a, the distinct pores can merge, thus forming a periodic structure of one‐dimensional photonic crystal. Optical properties of grooved structures with merged pores have been investigated by means of Fourier infrared reflection micro‐spectroscopy in the spectral range from 1.45 μm to 16.5 μm. Reflectance spectra reveal presence of photonic band gaps which positions in the middle IR range are in a good agreement with calculations by transfer matrix method. The fabrication approach developed is promising for application in silicon‐based photonics. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Analysis of energy levels of InAs/GaAs self‐assembled quantum dots by using C –V and deep level transient spectroscopy
Authors: Kim Jin Soak , Kim Eun Kyu , Kim Jun Oh , Lee Sang Jun , Noh Sam Kyu
Published: February 2009

Energy levels of InAs/GaAs self‐assembled quantum dot (QD) system were analyzed by capacitance–voltage (C –V) and deep level transient spectroscopy (DLTS) methods. The QD signals were partially separated by DLTS measurement with small bias changing. The activation energies of QD signals were varied from 66 meV to 610 meV by changing of 0.6 V applied bias, which energies are related to the confined energy levels of InAs QDs. Then, the ground states of InAs QDs were considered to be located at 0.61 eV below the conduction band edge of GaAs barrier. In addition, it showed that DLTS signal of QDs are largely affected by their density of energy state. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Two‐colour photocurrent detection technique for coherent control of a single InGaAs/GaAs quantum dot
Authors: Boyle Stephen J. , Ramsay Andrew J. , Kolodka Roman S. , Oliviera Jose B. B. , Liu Hui Yun , Hopkinson Mark , Fox A. Mark , Skolnick Maurice S.
Published: February 2009

We present a two‐colour photocurrent detection method for coherent control of a single InGaAs/GaAs self‐assembled quantum dot. A pulse shaping technique provides a high degree of control over picosecond optical pulses. Rabi rotations on the exciton to biexciton transition are presented, and fine structure beating is detected via time‐resolved measurements. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical probing of spin fluctuations of a single magnetic atom
Authors: Besombes Lucien , Léger Yoan , Bernos Julien , Le‐gall Claire , Boukari Herve , Poizat Jean Philippe , Mariette Henri
Published: February 2009

We analyzed the photoluminescence intermittency generated by a single paramagnetic spin localized in an individual semiconductor quantum dot (QD). The statistics of the photons emitted by the QD reflect the quantum fluctuations of the localized spin. We report photon correlation measurements that reveal unique signatures of these fluctuations. A phenomenological model is proposed to quantitatively describe these observations, allowing a measurement of the spin dynamics of an individual magnetic atom at zero magnetic field. The data demonstrate the existence of a spin relaxation channel arising from a spin‐exchange with individual free carriers surrounding the QD. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth and properties of defect‐free ZnSe nanowires and nanoneedles
Authors: Aichele Thomas , Tribu Adrien , Bougerol Catherine , Kheng Kuntheak , Donatini Fabrice , Dang Le Si , André Régis , Tatarenko Serge
Published: February 2009

ZnSe nanowires heterostructures were grown by molecular beam epitaxy in the vapour–liquid–solid growth mode assisted by gold catalysts. Size, shape and crystal structure are found to strongly depend on the growth conditions. Both, zinc‐blende and wurtzite crystal structures are observed using transmission electron microscopy. At low growth temperature nanoneedles are formed. For higher growth temperature, the nanowires have a high aspect ratio with sizes of 1–2 μm in length and 20–50 nm in width as observed by scanning electron microscopy. Growing a nanowire on top of the base of a nanoneedle allows us to obtain very narrow structures with a diameter less than 10 nm and a low density of stacking fault defects. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electrical injection of spin‐polarized electrons into single quantum dots
Authors: Kümmell T. , Arians R. , Huang J. , Wenisch J. , Brunner K. , Bacher G.
Published: February 2009

We demonstrate electrical spin‐injection into a single InAs quantum dot embedded in a GaAs‐based p–i–n diode structure using a diluted magnetic semiconductor (ZnMnSe) as a spin‐source. The spin‐information can be extracted directly by evaluating the polarisation degree of the single quantum dot electroluminescence signal. We obtain a spin‐polarisation up to 100% at T = 5 K that is decreasing with higher temperature. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Infrared study of the oxidation of porous silicon: evidence of surface modes
Authors: Acquaroli L. N. , Brondino A. , Schmidt J. A. , Arce R. D. , Koropecki R. R.
Published: February 2009

The evolution of FTIR spectra of PS during oxidation is studied in the range 450‐1300 cm–1. We show that the small scale of the PS structure leads to a significant scattering cross section for Fröhlich surface modes associated to stretching modes in siloxane bridges. The kinetics of the evolution of both bulk‐ and surface‐related modes are studied using Principal Component Analysis. As a result, two independent components are found, one of them related to TO modes associated to silicon oxide covering large structures and the other one associated to the oxidation of a distribution of prolate ellipsoids with nanoscopic size. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Detection and light enhancement of glucose oxidase adsorbed on porous silicon microcavities
Authors: Palestino Gabriela , Martin Marta , Agarwal Vivechana , Legros René , Cloitre Thierry , Zimányi László , Gergely Csilla
Published: February 2009

Porous silicon (PSi) structure is used as support material to detect protein infiltration and to induce fluorescence and second harmonic light enhancement from glucose oxidase (GOX). Functionalization and protein infiltration is monitored by specular reflectometry. Optical response enhancement of PSi microcavity structures compared to PSi single layers or Bragg mirrors is observed, when GOX is impregnated. Penetration of organic molecules along the PSi microcavity structure is demonstrated by energy dispersive X‐ray profile. Enhanced fluorescence emission of GOX when adsorbed on PSi microcavity is evidenced by multi‐photon microscopy (MPM). Second harmonic light generation is observed at some particular pores of PSi and subsequent resonance enhancement of the signal arising from the GOX adsorbed within the pores is detected. Our work evidences an improved device functionality of GOX‐PSi microcavities due to strongly confined and localized light emission within these structures. This opens the way towards the application of PSi microcavity structures as amended biosensors based on their locally enhanced optical response. The second main achievement lies in the novelty of the used techniques. In contrast to the specular reflectometry used to monitor the macroscopic optical response of PSi structures, MPM presents a valuable alternative microscopic technique probing individual pores. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Pore growth on n‐type InP investigated by in‐situ FFT impedance spectroscopy
Authors: Leisner Malte , Carstensen Jürgen , Cojocaru Ala , Föll Helmut
Published: February 2009

In this work in‐situ FFT impedance spectroscopy is applied to analyze the growth of current‐line oriented pores in (100) oriented n‐type InP. A fitting model based on standard electrical equivalent elements is developed, which yields very consistent and good results during the course of long‐time etching experiments. An analysis based on the time and parameter dependence of the fitting parameters, as well as a measurement of the pore depth as a function of etching time, allows to identify the physico‐chemical reactions and processes related to the different parts of the impedance. The interface (reaction) at the pore tips, a mass transfer phenomenon inside the pores, as well as a third process located outside the pores are observed. The characteristic behavior of these processes under variations of the electrolyte concentration or the applied external potential yields a deep insight into the total pore formation process: The potential drop over the interface at the pore tips could be identified to be independent of the HCl concentration or applied external potential. The mass transfer process is directly responsible for the total current flowing, and thus for the growth rate of the pores. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Evolution of nanoporous silicon phase composition and electron energy structure under natural ageing
Authors: Turishchev Sergey , Lenshin Alexander , Domashevskaya Evelina , Kashkarov Vladimir , Terekhov Vladimir , Pankov Konstantin , Khoviv Dmitry
Published: February 2009

Nanoporous silicon layers were obtained on different types of single crystalline silicon substrates by standard electrochemical etching in HF solution. Investigations of electron structure, surface layers phase composition and photoluminescence evolution in nanoporous silicon during natural ageing for the time period for up to one year were performed with the use of the ultrasoft X‐ray emission spectroscopy (USXES), X‐ray absorption near‐edge structure (XANES) spectroscopy and photoluminescence. USXES and XANES spectra represent local partial density of states in valence and conduction band, correspondingly. The presence of the elementary silicon together with different silicon suboxides in surface layers is shown. Considerable differences in the kinetics of ageing can explain different photoluminescence properties of nanoporous silicon doped with P and Sb. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Transition metals specifically electrodeposited into porous silicon
Authors: Rumpf Klemens , Granitzer Petra , Poelt Peter , Krenn Heinz
Published: February 2009

Porous silicon (PS) is fabricated by anodization in aqueous hydrofluoric acid solution in the transition region between meso and macro pores. In the employed process the pore‐diameters are adjustable from 30 nm up to 100 nm using the same electrolyte as well as the same doping density of the wafer. Furthermore the self‐assembled pore‐arrangements show a quasi‐regular three‐dimensional nano‐architecture. These achieved PS‐membranes offering oriented pores with an aspect ratio around 1000 are filled with a transition metal in a galvanic deposition process. The use of different metals (Ni, Co, NiCo, Cu) together with the proper variation of the deposition parameters (e.g. current density and pulse duration) as well as the employment of different morphologies of the templates allow to tune the shape of the metal precipitations as well as their spatial distribution within the channels and therefore the possibility arises to influence the physical properties of the specimens. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Microstructure and optical properties of porous silicon after plasma assisted nitridation
Authors: Frascella F. , Mandracci P. , Venturello A. , Sciacca B. , Giorgis F. , Geobaldo F.
Published: February 2009

Porous silicon samples have been subjected to plasma treatments under ammonia atmosphere. The samples were characterized by IR, UV‐Visible reflectance and stationary photoluminescence spectroscopies. A deep modification concerning both surface and bulk properties of silicon nanocrystals is clearly observed. In particular, the nanocrystals surface is covered by amino groups, as checked by IR spectroscopy, whilst bulk modification can be inferred by UV‐Visible reflectance and luminescence characterizations, in particular for high porosity. The results demonstrate that plasma assisted nitridation yields to a controllable modification of the optical and chemical properties of porous silicon, without need of thermal annealing and/or wet chemical processes. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Protein‐mesoporous silicon matrix obtained by S‐layer technology
Authors: Kleps Irina , Ignat Teodora , Miu Mihaela , Simion Monica , Popescu Gabriela Teodosiu , Enache Madalin , Dumitru Lucia
Published: February 2009

Protein layers on porous silicon (PS) substrates were prepared using haloarchaea strain Haloferax sp. as S‐layer subunits. The attaching of S‐layer at PS samples was performed by immersing the PS samples in S‐layer solution in sterile conditions, followed by 24 hours incubation at two temperatures, 4 and 24 °C. Spectrophotometric determination of the S‐layer attachment on the porous silicon substrate was performed at 280 nm wavelength by measuring the protein concentration in solution before and after the incubation of PS samples. The protein layer morphology on the PS substrate was investigated by electron microscopy. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Atomic simulation of the 30° partial dislocation interaction with divacancy in silicon
Authors: Wang Chaoying , Meng Qingyuan
Published: February 2009

The interactions of the 30° partial dislocation with a divacancy (V2) in silicon are investigated by the molecular dynamics simulation method. The results under different temperature and shear stress conditions show that the 30° partial dislocation is pinned when the dislocation encounters V2. When the shear stress approaches a critical value τc, the dislocation can overcome the pin. As the temperature increases, τc decreases approximately as a linear function. Moreover, it is found that τc is mainly determined by the migration barrier of the corresponding kink. Finally, V2 can make the 30° partial dislocation move faster once the dislocation overcomes the pin. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Correlation of pre‐breakdown sites and bulk defects in multicrystalline silicon solar cells
Authors: Lausch Dominik , Petter Kai , Wenckstern Holger von , Grundmann Marius
Published: February 2009

Strong correlation between the pre‐breakdown sites visible in dark lock‐in thermography due to local heating and the intensity of spatially resolved electroluminescence of reverse‐biased solar cells was observed. By comparing differently texturised solar cells we could show that the pre‐breakdown sites are not correlated to the surface morphology, e.g. etch pits resulting in local field enhancement. The positions of the pre‐breakdown sites are identical for acidic and alkaline texturised solar cells and therefore are directly related to bulk defects in the wafer. Nevertheless, the breakdown voltage is lower for acidic texturised solar cells; the parameters of breakdown are influenced by the texture in contrast to the position. Also pre‐breakdown sites are observed in areas without specific surface features for alkaline texturised solar cells. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Identification of new trace triterpenoid saponins from the roots of Panax notoginseng by high‐performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry
Authors: Liu Yuanyan , Li Jianbei , He Jiuming , Abliz Zeper , Qu Jing , Yu Shishan , Ma Shuanggang , Liu Jing , Du Dan
Published: February 2009

Triterpenoid saponins are the major bioactive constituents of Panax notoginseng. In the study reported here, the fragmentation behavior of triterpenoid saponins from P. notoginseng was investigated by electrospray ionization tandem mass spectrometry (ESI‐MSn)and high‐performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (HPLC/ESI‐MSn). Analyses revealed that product ions from glycosidic and cross‐ring cleavages can give a wealth of structural information regarding the nature of the aglycone, sugar types, the sequence and linkage information of sugar units. It is noted that different glycosylation positions remarkably influenced the fragmentation behaviors, which could assist in the differentiation of saponin analogues. To rationalize this characteristic, the collision energy required for various glycosidic cleavages was investigated. According to the summarized fragmentation rules, identification of triterpenoid saponins from the roots of P. notoginseng could be fulfilled, even when reference standards were unavailable. Furthermore, minor and trace constituents were enriched and detected by eliminating the major constituents in one of the saponin fractions. As a result, a total of 151 saponins, including 56 new trace ones, were identified or tentatively characterized from saponin fractions based on their retention times, HPLC/HRMS, HPLC/ESI‐MSn fragmentation behaviors and comparison with literature data. Copyright © 2009 John Wiley & Sons, Ltd.
Equitable coloring of random graphs
Authors: Krivelevich Michael , Patkós Balázs
Published: February 2009

An equitable coloring of a graph is a proper vertex coloring such that the sizes of any two color classes differ by at most one. The least positive integer k for which there exists an equitable coloring of a graph G with k colors is said to be the equitable chromatic number of G and is denoted by χ=(G). The least positive integer k such that for any k′ ≥ k there exists an equitable coloring of a graph G with k′ colors is said to be the equitable chromatic threshold of G and is denoted by χ=*(G). In this paper, we investigate the asymptotic behavior of these coloring parameters in the probability space G(n,p) of random graphs. We prove that if n−1/5+ϵ < p < 0.99 for some 0 < ϵ, then almost surely χ(G(n,p)) ≤ χ=(G(n,p)) = (1 + o(1))χ(G(n,p)) holds (where χ(G(n,p)) is the ordinary chromatic number of G(n,p)). We also show that there exists a constant C such that if C/n < p < 0.99, then almost surely χ(G(n,p)) ≤ χ=(G(n,p)) ≤ (2 + o(1))χ(G(n,p)). Concerning the equitable chromatic threshold, we prove that if n−(1−ϵ) < p < 0.99 for some 0 < ϵ, then almost surely χ(G(n,p)) ≤ χ=* (G(n,p)) ≤ (2 + o(1))χ(G(n,p)) holds, and if ${{\log^{1+\epsilon}n}\over {n}}$ < p < 0.99 for some 0 < ϵ, then almost surely we have χ(G(n,p)) ≤ χ=*(G(n,p)) = Oϵ(χ(G(n,p))). © 2009 Wiley Periodicals, Inc. Random Struct. Alg., 2009
Peer and inmate aggression, type D‐personality and post‐traumatic stress among Dutch prison workers
Authors: Kunst Maarten J. J. , Bogaerts Stefan , Winkel Frans W.
Published: February 2009

This study investigated the adverse effects of exposure to inmate or peer aggression, type D‐personality and their interactions on post‐traumatic stress reactions among a sample of prison workers. The basic tenet of type D‐personality is that not so much the experience of negative emotions per se is responsible for negative health consequences, but rather the way individuals cope with such emotions. Many studies have revealed diverse adverse health outcomes of type D‐personality, particularly among cardiac patients. However, the moderating effect of social inhibition has never been statistically examined in other populations. Participants (111 men, 40 women) were recruited in 10 Dutch correctional institutions. The results showed that victims of aggression are more prone to develop Post‐traumatic Stress Disorder (PTSD) symptoms than non‐victims, although this particularly applied to victims of peer aggression. Furthermore, an interaction effect was observed between inmate aggression and type D‐personality. Finally, both peer aggression and type D‐personality contributed to the development of PTSD. The results were discussed together with recommendations for future research. Copyright © 2009 John Wiley & Sons, Ltd.
Life context and the experience of chronic illness: is the stress of life associated with illness perceptions and coping?
Authors: Karademas Evangelos C. , Karamvakalis Nikolaos , Zarogiannos Aristides
Published: February 2009

Stress resulting from the broader life context (life stress) is involved in the development and progress of many diseases, as well as in the adjustment to chronic illness. It may also be associated with the specific ways patients perceive and respond to illness. In this respect, the purpose of this study was to examine the possible relationships between life stress, and illness‐related perceptions and coping. A cross‐sectional design was employed. Participants completed measures regarding life stress, illness perceptions, illness‐related coping and restrictions imposed by the illness. One hundred and one chronically ill outpatients participated in the study. Their mean age was 51.10 years (SD = 12.88), and the mean time elapsed since initial diagnosis was 12.74 years (SD = 9.32). According to the results, life stress was associated with certain illness perceptions (i.e. personal control over illness, illness consequences) and illness‐related coping strategies (i.e. palliative coping, emotional reactions), even after controlling for sociodemographic variables and illness‐associated factors. Moreover, illness consequences mediated the effects of life stress on the two coping strategies. These results underline the significance of the broader life context regarding the experience of chronic illness. Copyright © 2009 John Wiley & Sons, Ltd.
A Systematic Nomenclature for Codifying Engineered Nanostructures
Authors: Gentleman Darcy J. , Chan Warren C. W.
Published: February 2009

Nanotechnology's growing applications are fueled by the synthesis and engineering of a myriad nanostructures, yet there is no systematic naming or classification scheme for such materials. This lack of a coherent nomenclature is confusing the interpretation of data sets and threatens to hamper the pace of progress and risk assessment. A systematic nomenclature that encodes the overall composition, size, shape, core and ligand chemistry, and solubility of nanostructures is presented. A typographic string of minimalist field codes facilitates digital archiving and searches for desired properties. This nomenclature system could also be used for nanomaterial hazard labeling.
Toward a framework of innovation management in logistics firms: A systems perspective
Authors: Shen Hao , Wang Longwei , Xu Qiang , Li Yuan , Liu Xunfeng
Published: February 2009

With the rapid circumstance changes, innovation has become a strategic choice for many logistics firms in the 21st century. In this paper, we will see innovation as a system which is composed of six elements. We will also look at the relationships among these elements in the context of the systems theory. Finally, we will suggest how to manage the enterprise innovation system (EIS) to achieve systematic innovation and sustained innovation to attain competitive advantages with strategic perspectives for logistics firms. Copyright © 2009 John Wiley & Sons, Ltd.
An extension of technology acceptance model: Analysis of the adoption of mobile data services in China
Authors: Qi Jiayin , Li Ling , Li Yuanquan , Shu Huaying
Published: February 2009

Mobile data services are entering into all aspects of people's life and are expected to be an important revenue source of telecom carriers. Nevertheless, the acceptance pace of mobile data services is slower than the expected level projected by the telecommunication industry. This research investigated the reason that people use mobile data services in China. Combined with subscribers' experience factors, an extended technology acceptance model (TAM) for mobile data services was presented. The model was tested using data collected from 802 mobile subscribers. The findings of the study indicate that mobile voice service and innovation experience of mobile data services affect subscribers' consumption intention greatly; subscribers' perceived ease‐of‐use and brand experience influence subscribers' attitude towards mobile data services largely. Promotion of mobile data services is most effective when it is promoted with perfect voice service experience. Additionally, our findings suggest that mobile service carriers need to enhance their investments in mobile data services' R&D. Collaboration among the value chain members of mobile data services will promise cutting‐edge new products and services. Using system methodology, a mobile data service infusion system model was constructed to explain the general adoption rules of mobile data services. The adoption of mobile data services in mobile logistics area was also discussed. Copyright © 2009 John Wiley & Sons, Ltd.
A system dynamics approach to competitive strategy in mobile telecommunication industry
Authors: Qi Jiayin , Li Ling , Ai Hua
Published: February 2009

This paper analyses the mobile carriers' competition strategies by using balanced scorecard and system dynamics (SD) modelling. Four indexes are used to evaluate two major Chinese mobile telecom carriers, which are Internal Business Index, Financial Index, Market and Customer Index and Innovation and Learning Index. With these four indexes, a SD model is developed based on systems methodology, which includes eight sub‐systems and 80 variables. Considering the government's regulation policy, the two carriers' competitive strategies are studied through modelling and simulaton. The result shows that for carrier B, improving the investment efficiency is more important; while for carrier A, the product innovation is an essential issue. This research explores an effective way to construct an analytical framework for dynamic competitive strategy. Copyright © 2009 John Wiley & Sons, Ltd.
In‐Situ‐Charakterisierung optischer Mehrschichtsysteme in Großflächen‐ Produktionsanlagen
Authors: Deus Carsten , Prö Holger
Published: February 2009

Bei der industriellen Produktion komplexer optischer Schichtstapel wie Spiegel‐, Antireflex‐und LowE‐Beschichtungen auf großen Substraten sind in die Beschichtungsanlage integrierte optische Analysesysteme unverzichtbare Hilfsmittel, um eine stabile Produktion innerhalb der oft engen Produkttoleranzen gewährleisten zu können. Diese stellen im Idealfall nicht nur die zur Qualitätskontrolle erforderlichen spektralen Informationen und daraus abgeleitete Gütekriterien zur Verfügung, sondern unterstützen das Bedienpersonal mit Informationen zur Dicke der Einzelschichten bei der schnellen Erkennung und Korrektur von Abweichungen vom Zielschichtsystem. Es werden Lösungsansätze auf der Basis von in‐situ gemessenen Reflexions‐, Transmissions‐und Ellipsometriespektren vorgestellt, die zur Schichtdickenberechnung nicht nur die Spektren des kompletten Schichtstapels, sondern auch während der Abscheidung aufgenommene Spektren von Teilstapeln berücksichtigen. Dabei werden Genauigkeit, Robustheit und Stabilität verschiedener Mess‐und Auswertestrategien miteinander verglichen.
Die patentierten Erfindungen von Wolfgang Gaede aus der Zeit von 1905 bis 1945
Authors: Henning Hinrich
Published: February 2009

Die Liste von Gaedes Patenten ist ein Beispiel aus früher Zeit für eine fruchtbare Zusammenarbeit zwischen Industrie und Wissenschaft, aus der mehrere bis in unsere Zeit wichtige Erfindungen hervorgegangen sind. Die Verbindung hat schwere Zeiten überdauert und hielt selbst dann, als Gaede von den Nazis widerrechtlich zum Verzicht auf seinen Lehrstuhl gezwungen wurde.
Anlagen für die Solarzellen‐Schichterzeugung benötigen hervorragend ausgelegte Vakuumsysteme
Authors: Kuhn Monika
Published: February 2009

Die Auslegung geeigneter Vakuumlösungen für die Produktion von Solarzellen mittels Dünnschichttechnologie ist eine der großen Herausforderungen für die Hersteller von Vakuumpumpen.

Eine exakte Abstimmung des Systems auf die jeweiligen Einsatzfälle in Hinblick auf Sicherheit, Korrosion, Gefahrenpotential und Robustheit ist nur durch Einsatz unterschiedlicher Pumptechnologien in Verbindung mit umfangreichem Applikationswissen und geeignetem Zubehör möglich. Die Herausforderungen werden in den kommenden Jahren wachsen, da die Produktionsprozesse ständigen Veränderungen unterliegen und die Erfahrung auf Seiten der Betreiber begrenzt ist.

Eine ständige Produktanpassung an geänderte Prozessbedingungen ist unumgänglich, um langfristig die Kosten zu senken und die Zuverlässigkeit der Systeme zu erhöhen.
Color inhibition of phenolic antioxidants in Ziegler‐Natta polyethylene. I. In‐situ polymer studies
Authors: Allen Norman S. , Liauw Christopher M. , Reyes Aitor , Edge Michele , Johnson Brian , Keck‐Antoine Klaus
Published: February 2009

Although the level of transition‐metal catalyst residues in polyethylene (PE) has been drastically reduced over the years, they can still give rise to discoloration, particularly when associated with other additives such as antioxidants. This first of this series of papers screens a variety of candidate color suppressants featuring a range of functional groups, including alcohols, amine/sulfur compounds, and acid‐containing species. These candidate color suppressants were melt‐blended into a Ziegler‐Natta linear low‐density PE in combination with 2,2′‐isobutylidenebis(4,6‐dimethylphenol) (a highly discoloring hindered bisphenol antioxidant) and zinc stearate antacid. Yellowness index measurements made after multiple extruder passes indicated that dipentaerythritol (DPE) and triisopropylamine (TIPA) gave good color inhibition and, in some cases, outperformed established phosphites. The DPE and TIPA were found (via melt flow rate measurement) not to affect melt stability, and hydroperoxide determination revealed that DPE had no peroxide decomposition activity. The latter results indicate that the color‐suppression mechanism of DPE and TIPA is different from that associated with phosphites. J. VINYL ADDIT. TECHNOL., 2009. © 2009 Society of Plastics Engineers
Recent developments in biopolymers
Authors: Flaris Vicki , Singh Gurpreet
Published: February 2009

Society has been reaping the benefits of industrial polymers for a long time. Polymers have entered every market in a very influential manner, from the packaging industry to the construction business. The very properties that made polymers commercially viable are posing great environmental problems for our future generations. Also, the starting material for most of the commercial polymers is crude oil. Thus, environmental issues coupled with decreasing crude oil reserves have forced the polymer industry to find new sources. These problems having been taken into consideration, biopolymers have emerged as a promising field. This paper takes into consideration the sources of renewable materials, such as starch, lignocellulosic biomass, vegetable oils, proteins, etc.; the synthesis of polymers such as polylactic acid and monomers such as furfural, ethane, propanediol, etc., from renewable materials; and the recent developments in this field. J. VINYL ADDIT. TECHNOL., 2009. © 2009 Society of Plastics Engineers
New measurements and observations on aged NaI detectors
Authors: Tartari A. , Di Domenico G. , Bonifazzi C. , Baraldi C.
Published: February 2009

The dead layer near the front surface of aged or damaged NaI detectors produces both an energy dependent diminution in counting efficiency and a characteristic iodine K x‐ray peak, which interferes with the registered radiation spectra. In this paper, the exploitation of this peak as an internal reference to assess the dead layer thickness and the relative loss of detector quality is proved by means of a comparison between experiments and Monte Carlo simulations. Investigations with different NaI‐based equipments and photon transport simulations are carried out in order to assess the detector degradation in terms of peak interference, efficiency and resolution. Copyright © 2009 John Wiley & Sons, Ltd.
Management of Upper Extremity Vascular Injury: Outcome Related to the Mangled Extremity Severity Score
Authors: Prichayudh Supparerk , Verananvattna Aumpavan , Sriussadaporn Suvit , Sriussadaporn Sukanya , Kritayakirana Kritaya , Pak‐art Rattaplee , Capin Allan , Pereira Bruno , Tsunoyama Taichiro , Pena Diego
Published: February 2009

Background

The Mangled Extremity Severity Score (MESS) is an objective criterion for amputation prediction after lower extremity injury as well as for amputation prediction after upper extremity injury. A MESS of ≥7 has been utilized as a cutoff point for amputation prediction. In this study, we examined the result of upper extremity vascular injurty (UEVI) management in terms of the amputation rate as related to the MESS.

Methods

During January 2002 to July 2007, we reviewed patients with UEVIs at our institution. Data collections included demographic data, mechanism of injuries, injury severity score (ISS), ischemic time, MESS, pathology of UEVI, operative management, and amputation rate. Decisions to amputate the injured limbs at our institution were made individually by clinically assessing limb viability (i.e., color and capillary refill of skin; color, consistency, and contractility of muscles) regardless of the MESS. The outcome was analyzed in terms of the amputation rate related to the MESS.

Results

There were 52 patients with UEVIs in this study: 25 (48%) suffered blunt injuries and 27 (52%) suffered penetrating injuries. The age ranged from 15 to 59 years (mean 28.7 years). The mean ischemia time was 10.07 h. The mean ISS was 17.52. There were 12 patients (23%) with subclavian artery injuries, 3 patients (5.76%) with axillary artery injuries, 18 patients (34.61%) with brachial artery injuries, and 19 patients (36.54%) with radial artery and/or ulnar artery injuries. Primary repairs were performed in 45 patients (86.54%), with ligations in 3 patients (5.77%). An endovascular stent‐graft was used in one patient (1.92%). Primary amputations were performed in three patients (5.77%). Secondary amputations (amputation after primary operation) were done in 4 of 49 patients (secondary amputation rate 8.16%). All amputation patients suffered blunt injuries and had a MESS of ≥7 (range 7–11). The overall amputation rate in this study was 13.46% (7/52 patients). Multivariate analysis revealed that the only factor significantly associated with amputation was the MESS. There were no amputations in 33 patients who had a MESS of <7. We could avoid amputation in 12 of 19 patients who had a MESS ≥7. There were no mortalities among 52 UEVI patients.

Conclusions

MESS, an outcome score used to grade the severity of extremity injuries, correlates well with the risk of amputation. Nevertheless, a MESS of ≥7 does not always mandate amputation. On the other hand, the MESS is a better predictor for patients who do not require amputation when the score is <7. The decisions to amputate in patients should be made individually based on clinical signs and an intraoperative finding of irreversible limb ischemia.
Cervical degenerative changes in idiopathic scoliosis patients who underwent long fusion to the sacrum as adults: incidence, severity, and evolution
Authors: Ofiram Elisha , Garvey Timothy A. , Schwender James D. , Wroblewski Jill M. , Winter Robert B.
Published: February 2009

Background

To date, there have been no published studies of the degenerative changes in the cervical spine in adult idiopathic scoliosis patients with thoracic and lumbar curves severe enough to require major reconstructive surgery.

Materials and methods

The primary study group was 48 adult patients who had previously undergone a fusion from T10 or higher to the sacrum as an adult for idiopathic scoliosis. These were compared to 38 adults with unfused idiopathic scoliosis of 30°–50° and to 42 symptomatic adults presenting with cervical pain. Cervical degeneration was assessed using a new cervical degenerative index (CDI).

Results

The amount of degenerative change seen in the cervical spine in the long-fusion group was significantly higher at baseline (just prior to the fusion) than the two control populations and became much higher at a mean follow-up of 8.5 years.

Conclusions

This unique subgroup of patients, those having fusion from the thoracic spine to the sacrum as adults for adolescent idiopathic scoliosis, had a high incidence and severity of degenerative changes in their cervical spine. Due to the presence of advanced cervical degenerative changes prior to the fusion, it is not possible to blame the fusion as the main cause for these findings. These changes are either related to the thoracic and lumbar deformities or are more likely due to this subgroup having a higher natural propensity for degenerative changes.
Decreased perinatal mortality among women with diet‐controlled gestational diabetes mellitus
Authors: Karmon Anatte , Levy Amalia , Holcberg Gershon , Wiznitzer Arnon , Mazor Moshe , Sheiner Eyal
Published: February 2009

Objective

To examine pregnancy outcomes associated with diet‐controlled gestational diabetes mellitus (GDM A1).

Methods

A retrospective cohort study compared pregnancy characteristics of women with and without GDM A1 at a center where GDM A1 patients are routinely induced at 40 weeks.

Results

Higher rates of complications such as shoulder dystocia, congenital malformation, and macrosomia were observed in GDM A1 patients. A lower incidence of perinatal mortality was present in GDM A1 women compared with women without GDM A1. This association lost its significance when controlled for maternal age, ethnicity, induction, cesarean delivery, and birth weight in a multivariate model. Although the stillbirth rate before 40 weeks of gestation was identical among all participants, after 40 weeks it was significantly higher in women without GDM A1.

Conclusion

Induction of women with GDM A1 at 40 weeks may play a role in lowering perinatal mortality to below that of the general population.
Analytic functions associated with strong Hamburger moment problems
Authors: Njåstad Olav
Published: February 2009

We complete the investigation of growth properties of analytic functions connected with the Nevanlinna parametrization of the solutions of an indeterminate strong Hamburger moment problem.
Meromorphic functions with shared limit values of positive linear measure
Authors: Sauer Andreas
Published: February 2009

We prove that if two transcendental meromorphic functions share all limit values from a set of positive linear measure on a rectifiable Jordan arc, then they share all limit values.
The curve exclusion theorem for elliptic and K3 fibrations birational to Fano 3-fold hypersurfaces
Authors: Ryder Daniel
Published: February 2009

The theorem referred to in the title is a technical result that is needed for the classification of elliptic and K3 fibrations birational to Fano 3-fold hypersurfaces in weighted projective space. We present a complete proof of the curve exclusion theorem, which first appeared in the author's PhD thesis and has since been relied upon in solutions to many cases of the fibration classification problem. We give examples of these solutions and discuss them briefly.
Endotrivial modules for the symmetric and alternating groups
Authors: Carlson Jon F. , Mazza Nadia , Nakano Daniel K.
Published: February 2009

In this paper we determine the group of endotrivial modules for certain symmetric and alternating groups in characteristic p. If p = 2, then the group is generated by the class of Ωn(k) except in a few low degrees. If p > 2, then the group is only determined for degrees less than p2. In these cases we show that there are several Young modules which are endotrivial.
Hecke C*-algebras and semi-direct products
Authors: Kaliszewski S. , Landstad Magnus B. , Quigg John
Published: February 2009

We analyse Hecke pairs (G,H) and the associated Hecke algebra $\mathcal{H}$ when G is a semi-direct product N ⋊ Q and H = M ⋊ R for subgroups M ⊂ N and R ⊂ Q with M normal in N. Our main result shows that, when (G,H) coincides with its Schlichting completion and R is normal in Q, the closure of $\mathcal{H}$ in C*(G) is Morita–Rieffel equivalent to a crossed product I⋊βQ/R, where I is a certain ideal in the fixed-point algebra C*(N)R. Several concrete examples are given illustrating and applying our techniques, including some involving subgroups of GL(2,K) acting on K2, where K = ℚ or K = ℤ[p−1]. In particular we look at the ax + b group of a quadratic extension of K.
Amalgamated free products of C*-bundles
Authors: Blanchard Etienne
Published: February 2009

Given two unital continuous C*-bundles, A and B, over the same compact Hausdorff base space X, we study the continuity properties of their different amalgamated free products over C(X).
Infinitely many arbitrarily small solutions for singular elliptic problems with critical Sobolev–Hardy exponents
Authors: He Xiaoming , Zou Wenming
Published: February 2009

Let Ω ⊂ ℝN be a bounded domain such that 0 ∈ Ω, N ≥ 3, 2*(s) = 2(N − s)/(N − 2), 0 ≤ s < 2, $0\leq\mu\lt\bar{\mu}=\frac{14}(N-2)^{2}$. We obtain the existence of infinitely many solutions for the singular critical problem $\smash{-\Delta u-\mu(u/|x|^2)=(|u|^{2^*(s)-2/|x|^s)u+\lambda f(x,u)$ with Dirichlet boundary condition for suitable positive number λ.
A problem of Ozanam
Authors: Bremner Andrew
Published: February 2009

A problem posed in the early eighteenth century asks for right-angled triangles, each of whose sides exceeds double the area by a perfect square. We summarize known results and find such triangles with the smallest possible standard generators.
On commuting elements and embeddings of graph groups and monoids
Authors: Kambites Mark
Published: February 2009

We study commutation properties of subsets of right-angled Artin groups and trace monoids. We show that if Γ is any graph not containing a four-cycle without chords, then the group G(Γ) does not contain four elements whose commutation graph is a four-cycle; a consequence is that G(Γ) does not have a subgroup isomorphic to a direct product of non-abelian groups. We also obtain corresponding and more general results in the monoid case.
Holomorphic mappings between compact Riemann surfaces
Authors: Ito Manabu , Yamamoto Hiroshi
Published: February 2009

There are only finitely many non-constant holomorphic mappings between two fixed compact Riemann surfaces of genus greater than 1. This result goes under the name of the de Franchis theorem. Having seen that the set of such holomorphic mappings is finite, we naturally want to obtain a bound on its cardinality. It has been known for some time that there exist various bounds depending only on the genera of the surfaces. Here we obtain ‘better’ bounds of the above type, using arguments based on the rigidity of holomorphic mappings and the hyperbolic geometry of surfaces.