bluuebunny/crossref_metadata_2025 huggingface dataset:
Organization and maintenance of immunological memory by stroma niches
Authors: Tokoyoda Koji , Zehentmeier Sandra , Chang Hyun‐Dong , Radbruch Andreas
Published: July 2009

Immunological memory is still one of the enigmas of modern immunology. We poorly understand the generation of memory cells from their precursors, the lifestyle of memory cells or their maintenance, reactivation and termination. Here, we discuss the recent evidence suggesting that memory plasma cells, as defined in this review, and memory Th cells are maintained in the bone marrow, resting (in terms of proliferation) in survival niches organized by dedicated stroma cells, which control the homeostasis of immunological memory.
Antimicrobial and immunoregulatory properties of human tryptophan 2,3‐dioxygenase
Authors: Schmidt Silvia K. , Müller Anika , Heseler Kathrin , Woite Claudia , Spekker Katrin , MacKenzie Colin R. , Däubener Walter
Published: July 2009

In mammals, the regulation of local tryptophan concentrations by the IFN‐γ‐i inducible enzyme IDO is a prominent antimicrobial and immunoregulatory effector mechanism. Here, we show for the first time that another tryptophan‐degrading enzyme, the liver‐specific tryptophan 2,3‐dioxygenase (TDO), is also capable of mediating antimicrobial and immunoregulatory effects. Using a tetracycline inducible eukaryotic system, we were able to express recombinant TDO protein, which exhibits functional properties of native TDO. We found that HeLa cells expressing recombinant TDO were capable of inhibiting the growth of bacteria (Staphylococcus aureus), parasites (Toxoplasma gondii) and viruses (herpes simplex virus). These TDO‐mediated antimicrobial effects could be blocked by the addition of tryptophan. In addition, we observed that, similar to IDO‐positive cells, TDO‐positive cells were capable of inhibiting anti CD3‐driven T‐cell proliferation and IFN‐γ production. Furthermore, TDO‐positive cells also restricted alloantigen‐induced T‐cell activation. Here, we describe for the first time that TDO mediates antimicrobial and immunoregulatory effects and suggest that TDO‐dependent inhibition of T‐cell growth might be involved in the immunotolerance observed in vivo during allogeneic liver transplantation.
Pathways of memory CD8+ T‐cell development
Authors: Bannard Oliver , Kraman Matthew , Fearon Douglas
Published: July 2009

CD8+ T‐cell responses must have at least two components, a replicative cell type that proliferates in the secondary lymphoid tissue and that is responsible for clonal expansion, and cytotoxic cells with effector functions that mediate the resolution of the infection in the peripheral tissues. To confer memory, the response must also generate replication‐competent T cells that persist in the absence of antigen after the primary infection is cleared. The current models of memory differentiation differ in regards to whether or not memory CD8+ T cells acquire effector functions during their development. In this review we discuss the existing models for memory development and the consequences that the recent finding that memory CD8+ T cells may express granzyme B during their development has for them. We propose that memory CD8+ T cells represent a self‐renewing population of T cells that may acquire effector functions but that do not lose the naïve‐like attributes of lymphoid homing, antigen‐independent persistence or the capacity for self‐renewal.
Inhomogeneous Magnet NaMnIII[BP2O7(OH)3]: Ferromagnetic Clusters Inserted in a Metamagnetic Matrix
Authors: Yang Tao , Zhang Yan , Lin Jianhua
Published: July 2009

NaMnIII[BP2O7(OH)3] (1) has been hydrothermally synthesized and characterized by single‐crystal X‐ray diffraction. The manganese(III) cations are coordinated in a tetragonal‐elongated octahedral environment, indicating the possible large magnetic anisotropy. The MnO6 octahedra are interconnected by BO4/PO4 groups, forming a 3D triclinic net of MnIII backbone. Detailed dc and ac magnetic measurements have been conducted, and a preliminary H–T phase diagram is deduced accordingly. Compound 1 adopts an unusual magnetic inhomogeneous model, consisting of ferromagnetic clusters and a metamagnetic background: At the paramagnetic temperature region, the Curie–Weiss fit shows that the manganese atoms are all in the high spin state (S = 2), and the predominant interaction is ferromagnetic. An antiferromagnetic ground state forms at approximately 10 K, the isothermal magnetizations between 6.5 and 10 K show the typical metamagnetism. At approximately 6.5 K, a short‐range ordering of the ferromagnetic cluster occurs. Below 3.5 K, the ferromagnetic clusters tend to be frozen at low external field, and the inhomogeneous magnetism can be clearly indicated by the isothermal magnetizations below 3 K. This unusual magnetism cannot be understood by the popular mechanism in doped manganese perovskites, which are well known to be magnetically inhomogeneous because of the mixed valence of manganese. In compound 1, one of the possible reasons for this unusual behaviour is the competition between magnetic superexchange interactions and the large magnetic anisotropy of MnIII.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Phosphorescence Color Alteration by Changing Counter Anions on Tetrahedral Gold(I) Complexes; Intra‐ and Interligand π–π Interactions
Authors: Osawa Masahisa , Kawata Isao , Igawa Satoshi , Tsuboyama Akira , Hashizume Daisuke , Hoshino Mikio
Published: July 2009

Tetrahedral gold(I) complexes containing the diphosphaneligand [dppb = 1,2‐bis(diphenylphosphanyl)benzene], [Au(dppb)2]X {X = Cl (1), BF4 (2) and PF6 (3)}, were prepared and characterized by X‐ray structural analysis. Complexes 1 and 2 have almost the same structure with two dppb ligands, which are symmetrically coordinated to the Au atom in the crystal. However, the two dppb ligands of 3 are asymmetrically bound to the gold(I) stom in the crystal. Both colorless complexes 1 and 2 exhibit intense blue phosphorescence with peak maxima at 481 nm (Φp = 0.86) for 1 and 490 nm (Φp = 0.90) for 2, respectively. The pale yellow complex 3 shows weak yellow‐orange phosphorescence with a peak maximum at 596 nm (Φp = 0.04). A small conformational change in the crystal, which is caused by changing the counter anion, dramatically alters the optical properties of the tetrahedral gold(I) complexes in the solid state. The difference in the absorption and phosphorescence spectra between 1 and 3 has been interpreted on the basis of molecular arrangement including packing structures of the complexes and time‐dependent density functional theory (TD‐DFT) calculations.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Polycationic States of Oligoanilines Based on Wurster's Blue
Authors: Ito Akihiro , Sakamaki Daisuke , Ino Haruhiro , Taniguchi Aya , Hirao Yasukazu , Tanaka Kazuyoshi , Kanemoto Katsuichi , Kato Tatsuhisa
Published: July 2009

Polycations of two oligoanilines based on Wurster's blue,N,N′,N″‐tris[4‐(dimethylamino)phenyl]‐N,N′,N″‐trimethyl‐1,3,5‐benzenetriamine (2) and N,N′‐bis(3‐{N‐[4‐(dimethylamino)phenyl]‐N‐methylamino}phenyl)‐N,N′‐dimethyl‐p‐phenylenediamine (3), have been generated efficiently by a stepwise oxidation procedure. Their redox behavior was characterized in terms of the embedded p‐phenylenediamine (PD) units and their intramolecular connectivity. EPR analysis of the oxidized 2 and 3 species revealed the existence of high‐spin species in solution. It was found that spin multiplicities of the dominant polycationic species of 2 and 3 formed by 3 equiv. of oxidant can be assigned to quartet and doublet states, respectively on the basis of pulsed EPR spectroscopy. These results demonstrate that the intramolecular connectivity between the spin‐containing units decisively influences the spin preference of the multispin systems based on oligoanilines.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Enol Nitrosation Revisited: Determining Reactivity of Ambident Nucleophiles
Authors: García‐Río Luis , Mejuto Juan C. , Parajó Mercedes , Pérez‐Lorenzo Moisés
Published: July 2009

Enols are one of the most important types of ambident nucleophiles being widely used as reagents in organic chemistry. The relevance of enols has led to considerable interest in developing methods to determine the reactivity of their nucleophilic centers. In this sense, the mainstream literature works on this topic make use of a combination of overall rate constants together with the analysis of the reaction products. By knowing the product ratio it is possible to determine the ratio between the reaction rates on each site. Thus, the reactivity for each nucleophilic position can be obtained. This is a reliable approach as long as the isolation or in situ characterization of the reaction products can be carried out. In the case of unstable and/or interconvertible products where the use of identification techniques is not possible, an alternative methodology must be found. For that reason, our research group has developed a model that allows us to study and quantify separately the reaction rates of enol nucleophilic centers even if only one final reaction product is obtained. This model is based on the fact that nitrosation of enols shows well‐differentiated behavior depending on whether the reaction proceeds through the carbon or the oxygen atom. The present study provides insights into the ambident nature of enols as well as a methodology for determining the chemical reactivity of their nucleophilic centers. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
An Efficient Synthesis of an Orthogonally Protected Aromatic Diamine as Scaffold for Tweezer Receptors with Two Different Arms
Authors: Kuchelmeister Hannes Y. , Schmuck Carsten
Published: July 2009

The synthesis of a new versatile template, 3‐(N‐Boc‐aminomethyl)‐5‐(N‐Fmoc‐aminomethyl)benzoic acid (1), was developed and is hereby reported. The key feature of the synthetic strategy is the selective mono reduction of a symmetric diazide using a biphasic reaction mixture. The mono reduction allows the sequential introduction of two orthogonal protecting groups – e.g., Fmoc and Boc. This building block can be used as a scaffold for the solid‐phase synthesis of dipodal or cyclic peptidic receptors. It allows the preparation of tweezer receptors with unsymmetrically substituted side arms and therefore for the implementation of an enhanced structural and functional diversity in comparison to symmetric tweezers.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Synthesis of Natural Products on Solid Phases via Copper‐Mediated Coupling: Synthesis of the Aristogin Family, Spiraformin A, and Hernandial
Authors: Jung Nicole , Bräse Stefan
Published: July 2009

The formation of natural products on solid phases via diaryl ether coupling is presented herein. Starting with either commercially‐available or easily‐producible benzoic, cinnamic, or propionic acids, all immobilized on Merrifield resin via a pentane linker, copper‐mediated couplings yielded solid phase diaryl ethers in good yields. Both, phenol and resins containing aryl halides were used for these Ullmann‐type couplings to generate resin‐bound natural product derivatives. Through cleavage from the resin, eight naturally occurring substances isolated from Aristolochia elegans, Hernandia nymphaeifolia, Spiraea formosana, and Kandelia candel were prepared. To the best of our knowledge, four of these compounds, namely Aristogin D and F as well as Spiraformin A and compound 12 have never previously been synthesized. Gaining access to these natural products on solid supports, demonstrated the utility of diaryl ether formation for the development of combinatorial syntheses. Our approach to diaryl ethers on solid support offers the possibility of synthesizing libraries of natural product derivatives via combinatorial syntheses. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
2‐D Difference in gel electrophoresis combined with Pro‐Q Diamond staining: A successful approach for the identification of kinase/phosphatase targets
Authors: Orsatti Laura , Forte Eleonora , Tomei Licia , Caterino Marianna , Pessi Antonello , Talamo Fabio
Published: July 2009

The protein tyrosine phosphatase PRL‐3 is an appealing therapeutic cancer target for its well described involvement in the metastasis progression. Nevertheless, very little is known about PRL‐3 role in tumorigenesis. In the attempt to identify the protein target of this phosphatase we have devised a model system based on the use of highly invasive HCT116 colon cancer cells over‐expressing PRL‐3. We used 2‐D difference gel electrophoresis combined with the fluorescence staining Pro‐Q Diamond selective for phosphorylated proteins to monitor changes in the phosphorylation status of possible substrates. Proteins whose phosphorylation level was negatively affected by PRL‐3 over‐expression were identified by MS. Two proteins were found to be significantly dephosphorylated in this condition, the cytoskeletal protein ezrin and elongation factor 2. Ezrin has already been described as having a proactive role in cancer metastasis through control of its phosphorylation status, and the PRL‐3‐induced modulation of ezrin phosphorylation in HCT116 and human umblical vascular endothelial cells is the subject of a separate paper by Forte et al. [Biochim. Biophys. Acta 2008, 1783, 334–344]. The combination of 2‐D difference in gel electrophoresis and Pro‐Q Diamond was hence confirmed successful in analyzing changes of protein phosphorylation which enable the identification of kinase/phosphatase targets.
DInSAR measurements of ground deformation by sinkholes, mining subsidence, and landslides, Ebro River, Spain
Authors: Castañeda Carmen , Gutiérrez Francisco , Manunta Michele , Galve Jorge P.
Published: July 2009

Differential Interferometric Synthetic Aperture Radar (DInSAR) has been applied to detect and measure ground deformation in a stretch of the Ebro River valley (Spain) excavated in salt‐bearing evaporites. The capability of the Small Baseline Subset (SBAS) DInSAR technique to detect ground displacement is analyzed comparing the DInSAR results with the available geomorphological information. The deformation map derived from 27 European Remote Sensing (ERS) satellite images covering more than five years provides sub‐centimeter displacement measurements in zones coinciding with known active sinkholes and landslides. Moreover the map provides the first account of mining subsidence in the area. The measured deformation rates reach 1·68 cm/y for the sinkholes, 0·80 cm/y for the landslides and 1·45 cm/y for the area affected by mining subsidence. The SBAS DInSAR technique provided deformation measurements in a small proportion (5–10%) of the known active sinkholes and landslides. This limitation is mainly due to the lack of coherence in agricultural areas, the spatial resolution of the deformation map (pixel size of 90 m), and the parallelism between the ERS satellite line of sight and the linear escarpment on which most of the landslides occur. Despite this, the interferometric technique provides valuable data that complement traditional geomorphological studies including the quantification of the deformation phenomena, the identification of mining subsidence otherwise only recognizable by geodetic methods, and the detection of creep deformation which might correspond to premonitory indicators of catastrophic sinkholes and landslides capable of causing the loss of lives. Detailed DInSAR studies combined with field data would be required to improve the analysis of each deformation area. Copyright © 2009 John Wiley & Sons, Ltd.
Determining thermal properties of gypsum board at elevated temperatures
Authors: Park Seul‐Hyun , Manzello Samuel L. , Bentz Dale P. , Mizukami Tensei
Published: July 2009

The National Institute of Standards and Technology (NIST) and the Center for Better Living have formed a collaboration to assess the performance and failure mechanisms of gypsum wall assemblies under real fires/furnace conditions. These measurements are being used to compile an experimental database necessary to validate models that could be used to predict their performance and ultimate failure under various design fires. A critical component of the database is thermal property data of gypsum board. The present paper describes the results of an effort to quantify thermal properties of gypsum board. The thermal conductivity specific heat mass loss and linear contraction for gypsum board types widely used in the U.S.A. and Japan were measured both at room temperature and at elevated temperatures. The gypsum board types tested include Type X and Type C from the U.S.A. and Type R and Type F from Japan. Results indicate that the difference in thermal properties of all gypsum board samples tested in the present study is not significant particularly at elevated temperatures. A large difference in linear contraction among gypsum board samples was observed at elevated temperatures, implying a significant difference in mechanical behavior at fire temperatures. The experimental data set provides valuable information that can be used to model the behavior of gypsum board at elevated temperatures. Copyright © 2009 John Wiley & Sons, Ltd.
Perfumes in Mediterranean antiquity
Authors: Castel Cécilia , Fernandez Xavier , Filippi Jean‐Jacques , Brun Jean‐Pierre
Published: July 2009

Perfumes in antiquity were products of great importance. They played an important role in seduction, feasts and ceremonies, religious rites, funerals and medicine. Antic perfumes were produced by extraction of fragrant raw materials (plants, gum resins, spices, etc.) using vegetable oil (ben, sesame, horseradish, almond, olive oil) as the main excipient. In the frame of new archaeological researches over the antic sites of Delos in Greece and Capua, Herculanum and Pompei in Italy, we sought to understand the composition of perfume in antiquity. How were antic perfumes made? Which fragrances characterized them? The Seplasia project, led by chemists and archaeologists, has the main intention of answering these questions. Copyright © 2009 John Wiley & Sons, Ltd.
Finite element and sensitivity analysis of thermally induced flow instabilities
Authors: Giguère Jean‐Serge , Ilinca Florin , Pelletier Dominique
Published: July 2009

This paper presents a finite element algorithm for the simulation of thermo‐hydrodynamic instabilities causing manufacturing defects in injection molding of plastic and metal powder. Mold‐filling parameters determine the flow pattern during filling, which in turn influences the quality of the final part. Insufficiently, well‐controlled operating conditions may generate inhomogeneities, empty spaces or unusable parts. An understanding of the flow behavior will enable manufacturers to reduce or even eliminate defects and improve their competitiveness. This work presents a rigorous study using numerical simulation and sensitivity analysis. The problem is modeled by the Navier–Stokes equations, the energy equation and a generalized Newtonian viscosity model. The solution algorithm is applied to a simple flow in a symmetrical gate geometry. This problem exhibits both symmetrical and non‐symmetrical solutions depending on the values taken by flow parameters. Under particular combinations of operating conditions, the flow was stable and symmetric, while some other combinations leading to large thermally induced viscosity gradients produce unstable and asymmetric flow. Based on the numerical results, a stability chart of the flow was established, identifying the boundaries between regions of stable and unstable flow in terms of the Graetz number (ratio of thermal conduction time to the convection time scale) andB, a dimensionless ratio indicating the sensitivity of viscosity to temperature changes. Sensitivities with respect to flow parameters are then computed using thecontinuous sensitivity equationsmethod. We demonstrate that sensitivities are able to detect the transition between the stable and unstable flow regimes and correctly indicate how parameters should change in order to increase the stability of the flow. Copyright © 2009 John Wiley & Sons, Ltd.
A simultaneous test of unit root and level change
Authors: Jun Duk Bin , Park Dae Keun
Published: July 2009

Testing the existence of unit root and/or level change is necessary in order to understand the underlying processes of time series. In many studies carried out so far, the focus was only on a single aspect of unit root and level change, therefore limiting a full assessment of the given problems. Our study aims to find a solution to the given problems by testing the two hypotheses simultaneously. We derive the likelihood ratio test statistic based on the state space model, and their distributions are created by the simulation method. The performance of the proposed method is validated by simulated time series and also applied to two Korean macroeconomic time series to confirm its practical application. This analysis can provide a solution to determine the underlying structure of arguable time series. Copyright © 2009 John Wiley & Sons, Ltd.
The effects of skewness on optimal production and hedging decisions: An application of the skew‐normal distribution
Authors: Lien Donald
Published: July 2009

Assume that the spot price has a skew‐normal distribution. This study investigates the effect of skewness on optimal production and hedging decisions. It is shown that skewness has no effect on the optimal production level but induces the firm to become more active in futures trading. © 2009 Wiley Periodicals, Inc. Jrl Fut Mark 30:278–289, 2010
The impact of off‐market trading on liquidity: Evidence from the Australian options market
Authors: Lepone Andrew , Yang Jin Young
Published: July 2009

This study investigates the impact of reducing the contract size threshold for off‐market trading on transaction costs in an options market. This study provides evidence that market makers compete more aggressively for small‐to‐medium trades and quote mid‐size depths more often after the regime change. Results also indicate that small‐to‐medium trades incur lower transaction costs; however, large trades that are executed on the central limit order book do not benefit from the structural transition. Given recent frictions imposed by regulators on equity markets, these results suggest that options markets provide an effective means for investors to replicate short‐selling in underlying securities. © 2009 Wiley Periodicals, Inc. Jrl Fut Mark 30:361–377, 2010
Racial and ethnic disparities in post‐stroke depression detection
Authors: Jia Huanguang , Chumbler Neale R. , Wang Xinping , Chuang Ho‐Chih , Damush Teresa M. , Cameon Randi , Williams Linda S.
Published: July 2009

Objectives

Post‐stroke depression (PSD) is common among stroke survivors and is associated with increased morbidity and mortality. Little is understood about racial/ethnic differences in PSD detection. This study assessed the racial/ethnic disparities in PSD detection in a national cohort of Department of Veterans Affairs (VA) acute stroke patients.

Methods

The study included VA patients who: received inpatient care for acute stroke within 2001; survived >60 days post‐index hospitalization; had an index stay <365 days; and were confirmed VA healthcare enrollees. PSD was established if a patient had a depression diagnosis in VA or Medicare inpatient or outpatient files, or was dispensed an antidepressant with guideline recommended minimum daily dosage during the 12 months post stroke. A multivariate logistic regression model was fitted to estimate the effects of race/ethnicity on PSD detection, adjusting for sociodemographic and clinical factors.

Results

The study cohort (N = 5825) was comprised of 66% white, 22% black, 7% Hispanic, and 6% for all other racial/ethnic categories. Among these stroke patients, 39% had PSD. Black and ‘all other’ racial/ethnic categories were significantly less likely to be diagnosed with PSD than non‐Hispanic whites, even adjusting for potential risk factors.

Conclusion

White, non‐Hispanic VA acute stroke patients were more likely to be diagnosed with PSD, even controlling for sociodemographic and clinical characteristics. Whether these findings suggest racial/ethnic differences in symptom endorsement by patients or in symptom recognition by providers is not clear. Copyright © 2009 John Wiley & Sons, Ltd.
Neural correlates of efficacy of voice therapy in Parkinson's disease identified by performance–correlation analysis
Authors: Narayana Shalini , Fox Peter T. , Zhang Wei , Franklin Crystal , Robin Donald A. , Vogel Deanie , Ramig Lorraine O.
Published: July 2009

LSVT® LOUD (Lee Silverman Voice Treatment) is efficacious in the treatment of speech disorders in idiopathic Parkinson's disease (IPD), particularly hypophonia. Functional imaging in patients with IPD has shown abnormalities in several speech regions and changes in these areas immediately following treatment. This study serves to extend the analysis by correlating changes of regional neural activity with the main behavioral change following treatment, namely, increased vocal intensity. Ten IPD participants with hypophonia were studied before and after LSVT LOUD. Cerebral blood flow during rest and reading conditions were measured by H215O‐positron emission tomography. Z‐score images were generated by contrasting reading with rest conditions for pre‐ and post‐LSVT LOUD sessions. Neuronal activity during reading in the pre‐ versus post‐LSVT LOUD contrast was correlated with corresponding change in vocal intensity to generate correlation images. Behaviorally, vocal intensity for speech tasks increased significantly after LSVT LOUD. The contrast and correlation analyses indicate a treatment‐dependent shift to the right hemisphere with modification in the speech motor regions as well as in prefrontal and temporal areas. We interpret the modification of activity in these regions to be a top–down effect of LSVT LOUD. The absence of an effect of LSVT LOUD on the basal ganglion supports this argument. Our findings indicate that the therapeutic effect of LSVT LOUD in IPD hypophonia results from a shift in cortical activity to the right hemisphere. These findings demonstrate that the short‐term changes in the speech motor and multimodal integration areas can occur in a top–down manner. Hum Brain Mapp, 2010. © 2009 Wiley‐Liss, Inc.
From large analogical instruments to small digital black boxes: 40 years of progress in mass spectrometry and its role in proteomics. Part II 1985–2000
Authors: Gelpí Emilio
Published: July 2009

This is the continuation of a personal retrospective on the developments that since 1965 have given shape to Mass Spectrometry (MS) and taken it from a position of simply playing a role in Protein Chemistry to becoming an indispensable tool in Proteomics, all within a 40‐year span. Part I covered the period from 1965 to 1984. This second part reviews the Mass Spectrometry timeline of events from 1985 to 2000, stopping at various time points where MS made significant contributions to protein chemistry or where the development of new instrumentation for MS represented a major advance for peptide and protein work. Major highlights in the field and their significance for peptide and protein characterization such as the advent and practical consequences of electrospray ionization (ESI) and matrix‐assisted laser desorption/ionization (MALDI) are covered, including work done with triple quads, the development of time‐of‐flight (TOF) instruments and new ion traps and going on to the more recent work on the full characterization of the Proteome with ion traps, TOF instruments and new ionization and tagging techniques for protein sequencing. Copyright © 2009 John Wiley & Sons, Ltd.
Design of a power system stabilizer using decentralized adaptive model following tracking control approach
Authors: Yu Wen‐Shyong
Published: July 2009

This paper presents the design of a power system stabilizer using decentralized adaptive model following tracking control (DAMFTC) approach to damp oscillations of generators in transient response subjected to uncertainties and generating fault actuators. The power system is represented as a collection of interconnected dynamical subsystems each described by a set of differential/algebraic equations using a clear representation of load voltage magnitude with matched and unmatched time‐varying uncertainties. All adaptive learning algorithms in this control system are derived in the sense of Lyapunov stability analysis subject to state errors due to uncertainties and fault section, so that stability and robustness of the closed‐loop system are ensured and asymptotic‐state tracking can be achieved. An adaptive bound estimation algorithm is investigated to relax the requirement for the bound of uncertainties. The effectiveness of the proposed approach is demonstrated by distributing a detailed simulation of the three‐machine nine‐bus system with nonlinear interactions, uncertainties, and fault actuators. The simulation includes the effects of network and stator transients. Copyright © 2009 John Wiley & Sons, Ltd.
Effect of transfection strategy on growth factor overexpression by articular chondrocytes
Authors: Shi Shuiliang , Mercer Scott , Trippel Stephen B.
Published: July 2009

Articular cartilage damage remains an unsolved problem in orthopaedics. Insulin‐like growth factor I (IGF‐I) and fibroblast growth factor‐2 (FGF‐2) are anabolic and mitogenic for articular chondrocytes, and are candidates for the application of gene therapy to articular cartilage repair. We tested the hypothesis that the production of IGF‐I and FGF‐2 can be augmented by modulating vector designs and delivery methods used for gene transfer to articular chondrocytes. We developed a novel adeno‐associated virus (AAV)‐based plasmid (pAAV) to overexpress IGF‐I and FGF‐2 cDNAs in adult bovine articular chondrocytes. We found that the pAAV‐based vectors generated significantly more growth factor than pcDNA vectors carrying the same cDNAs. Chondrocytes cotransfected with both IGF‐I and FGF‐2 cDNAs in two separate pAAV plasmids produced significantly more IGF‐I and FGF‐2 than cells transfected by a single pAAV plasmid carrying both cDNAs in a dicistronic cassette. These data indicate that pAAV vectors are more effective than pcDNA vectors for transfer of IGF‐I and FGF‐2 genes to articular chondrocytes. They further suggest that cotransfection may be an effective strategy for multiple gene transfer to these cells. These findings may be important in applying growth factor gene transfer to cell‐based articular cartilage gene therapy. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:103–109, 2010
Joint line elevation in revision TKA leads to increased patellofemoral contact forces
Authors: König Christian , Sharenkov Alexey , Matziolis Georg , Taylor William R. , Perka Carsten , Duda Georg N. , Heller Markus O.
Published: July 2009

One difficulty in revision total knee arthroplasty (TKA) is the management of distal femoral bone defects in which a joint line elevation (JLE) is likely to occur. Although JLE has been associated with inferior clinical results, the effect that an elevated joint line has on knee contact forces has not been investigated. To understand the clinical observations and elaborate the potential risk associated with a JLE, we performed a virtual TKA on the musculoskeletal models of four subjects. Tibio‐ and patellofemoral joint contact forces (JCF) were calculated for walking and stair climbing, varying the location of the joint line. An elevation of the joint line primarily affected the patellofemoral joint with JCF increases of as much as 60% of the patient's body weight (BW) at 10‐mm JLE and 90% BW at 15‐mm JLE, while the largest increase in tibiofemoral JCF was only 14% BW. This data demonstrates the importance of restoring the joint line, as it plays a critical role for the magnitudes of the JCFs, particularly for the patellofemoral joint. JLE caused by managing distal femoral defects with downsizing and proximalizing the femoral component could increase the patellofemoral contact forces, and may be a contributing factor to postoperative complications such as pain, polyethylene wear, and limited function. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:1–5, 2010
Absence of beta3 integrin accelerates early skeletal repair
Authors: Hu Diane , Lu Chuanyong , Sapozhnikova Anna , Barnett Michael , Sparrey Carolyn , Miclau Theodore , Marcucio Ralph S.
Published: July 2009

Integrins are heterodimeric transmembrane proteins that mediate cell–matrix interactions and modulate cell behavior. Beta3 subunit is a component of αIIβ3 and αVβ3 integrins. In this study, we first determined that β3 transcripts are expressed by cells within fracture calluses at 7 and 10 days after injury in a mouse model. We then analyzed fracture healing in mice deficient of β3 integrin with molecular, histomorphometric, and biomechanical techniques. We found that lack of β3 integrin results in an extended bleeding time and leads to more bone formation and accelerated cartilage maturation at 7 days after injury. However, β3 deficiency does not appear to affect later fracture healing. At days 14 and 21, histological appearance or biomechanical properties of fracture calluses are similar between wild type and mutant mice. We also found that altered fracture healing in β3‐null mice is not associated with accelerated angiogenesis, because no significant difference of length density and surface density of blood vessels in fracture limbs was detected at 3 days after injury between wild type and β3‐null mice. In conclusion, our findings demonstrate that β3 integrin plays an important role during early fracture healing. Further research is required to determine the underlying mechanisms. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:32–37, 2010
Experimental and theoretical investigation of vibrational spectra of copper phthalocyanine: polarized single‐crystal Raman spectra, isotope effect and DFT calculations
Authors: Basova Tamara V. , Kiselev Vitaly G. , Schuster Britt‐Elfriede , Peisert Heiko , Chassé Thomas
Published: July 2009

The IR‐ and Raman spectra of copper phthalocyanine (CuPc), as well as the isotopic wavenumber shifts upon 15N substitution in CuPc, were investigated experimentally and theoretically. The symmetry of molecular vibrations was determined using polarized Raman spectra of an oriented CuPc single crystal. Density functional theory (DFT) calculations were used for the detailed assignment of different bands in the vibrational spectra of CuPc. Theoretically predicted geometry, wavenumbers and isotopic shifts are in a very good agreement with the experimental values. A comparison of experimentally obtained isotopic shifts with theoretical predictions allowed us to reveal some characteristic features of normal vibrations of CuPc molecule. Copyright © 2009 John Wiley & Sons, Ltd.
The effects of laser irradiation of cartilage on chondrocyte gene expression and the collagen matrix
Authors: Holden Paul K. , Li Chao , Da Costa Victor , Sun Chung‐Ho , Bryant Susan V. , Gardiner David M. , Wong Brian J.F.
Published: July 2009

Objectives

Laser reshaping of cartilage is an emerging technology aimed at replacing conventional techniques for aesthetic and reconstructive surgery. Little is known about the mechanisms of wound healing following the photothermal heating during laser reshaping and, ultimately, how collagen remodels in the irradiated tissue. Healthy hyaline and elastic cartilage as found in the ear, nose, larynx, and trachea does not express collagen type I which is characteristic of fibro‐cartilage and scar tissue. The aim of the study was to determine if collagen I and II gene expression occurs within laser irradiated rabbit septal cartilage.

Methods

Nasal septum harvested from freshly euthanized New Zealand White rabbits were irradiated with an Nd:YAG laser. After 2 weeks in culture, the laser spot and surrounding non‐irradiated regions were imaged using immunofluorescence staining and evaluated using reverse transcription polymerase chain reaction (RT‐PCR) to determine the presence of collagen I and II, and ascertain collagen I and II gene expression, respectively.

Results

All laser irradiated specimens showed a cessation in collagen II gene expression within the center of the laser spot. Collagen II was expressed in the surrounding region encircling the laser spot and within the non‐irradiated periphery in all specimens. Immunohistochemistry identified only type II collagen. Neither collagen I gene expression nor immunoreactivity were identified in any specimens regardless or irradiation parameters.

Conclusions

Laser irradiation of rabbit septal cartilage using dosimetry parameters similar to those used in laser reshaping does not result in the detection of either collagen I gene expression or immunoreactivity. Only collagen type II was noted after laser exposure in vitro following cell culture, which suggests that the cellular response to laser irradiation is distinct from that observed in conventional wound healing. Laser irradiation of cartilage can leave an intact collagen matrix which likely allows chondrocyte recovery on an intact scaffold. Lasers Surg. Med. 41:487–491, 2009. © 2009 Wiley‐Liss, Inc.
Preparation of Glycogen‐Based Polysaccharide Materials by Phosphorylase‐Catalyzed Chain Elongation of Glycogen
Authors: Izawa Hironori , Nawaji Mutsuki , Kaneko Yoshiro , Kadokawa Jun‐ichi
Published: July 2009

Facile preparation of glycogen‐based polysaccharide gel materials was carried out by phosphorylase‐catalyzed chain elongation of glycogen using glucose 1‐phosphate (Glc‐1‐P). The resulting solution after the enzymatic reaction gradually turned into a hydrogel form, which was probably caused by formation of junction zones based on the double helix structure of the elongated amylose chains among the glycogen molecules. Furthermore, lyophilization of the hydrogel resulted in formation of a glycogen‐based xerogel. The mechanical properties of the hydrogels and xerogels were affected by the amount of glycogen and the Glc‐1‐P/glycogen ratio in the feed for the enzymatic reaction. The xerogel was also subjected to film formation and re‐hydrogelation with appropriate techniques.

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Entropically Driven Self‐Assembly of Lysinibacillus sphaericus S‐Layer Proteins Analyzed Under Various Environmental Conditions
Authors: Teixeira Leonardo Maestri , Strickland Aaron , Mark Sonny S. , Bergkvist Magnus , Sierra‐Sastre Yajaira , Batt Carl A.
Published: July 2009

S‐Layer proteins are an example of bionanostructures that can be exploited in nanofabrication. In addition to their ordered structure, the ability to self‐assembly is a key feature that makes them a promising technological tool. Here, in vitro self‐assembly kinetics of SpbA was investigated, and found that it occurs at a rate that is dependent on temperature, its concentration, and the concentration of calcium ions and sodium chloride. The activation enthalpy (120.81 kJ · mol−1) and entropy (129.34 J · mol−1 · K−1) obtained infers that the incorporation of monomers incurs in a net loss of hydrophobic surface. By understanding how the protein monomers drive the self‐assembly at different conditions, the rational optimization of this process was feasible.

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Branched Versus Linear Polyisoprene: Flory–Huggins Interaction Parameters for their Solutions in Cyclohexane
Authors: Eckelt John , Samadi Fatemeh , Wurm Frederik , Frey Holger , Wolf Bernhard A.
Published: July 2009

Flory‐Huggins interaction parameters were determined as a function of composition for solutions of linear and of branched polyisoprene in cyclohexane (CH) at 25, 45, and 65 °C by means of vapor pressure measurements (moderate to concentrated solutions) and by vapor pressure osmometry (dilute solutions). The results demonstrate that CH is a considerably worse solvent for branched polyisoprene than for the linear analog at all temperatures and at all compositions. This observation corroborates the expectation based on a recent phenomenological approach, which accounts explicitly for the incapability of the segments of an individual polymer molecule to spread out over the entire volume of the system and for its ability to adjust its chain conformation to an altering molecular environment.

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3‐Ethylated N‐Vinyl‐2‐pyrrolidone with LCST Properties in Water
Authors: Trellenkamp Taina , Ritter Helmut
Published: July 2009

The monomer 3‐ethyl‐1‐vinyl‐2‐pyrrolidone (3) and the homopolymer poly(3‐ethyl‐1‐vinyl‐2‐pyrrolidone) (5) have been synthesized. Polymer 5 is soluble in water and shows a critical temperature (Tc) of 27 °C. The presence of cyclodextrin causes a slight shift of the Tc. The lower critical solution temperature (LCST) could be varied between 27 and 40 °C by copolymerization with N‐vinyl‐2‐pyrrolidone. A linear correlation between the Tc and the copolymer composition is observed.

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Influence of Cross‐Linking Density on the Glass Transition and Structure of Chemically Cross‐Linked PVA: A Molecular Dynamics Study
Authors: Bermejo Javier Sacristan , Ugarte Carmen Mijangos
Published: July 2009

Mechanical properties and glass transitions of cross‐linked polymer networks depend strongly on both the network topology and cross‐linking density. A model is developed using a dynamic cross‐linking approach based on a cutoff distance criterion followed by a high‐temperature annealing procedure. The analysis focused on on the influence of cross‐linking degree on chain packing and hydrogen‐bond structure and on the roles played by various energy components in the glass transition process. Tg was calculated using two different methods; (i) from the intersection of lines drawn through points in a plot of specific volume versus temperature and (ii) from plots of different molecular energy components as a function of temperature.

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Temperature dependence of the 1J(11B19F) spin–spin coupling in BF3 molecule
Authors: Jackowski Karol , Makulski Włodzimierz , Szyprowska Anna , Antušek Andrej , Jaszuński Michał
Published: July 2009

The 1J(11B19F) spin–spin coupling of gaseous BF3 was observed in 11B NMR spectra as a function of density in a wide range of temperatures. Following the extrapolation of the measured values to the zero‐density limit, the coupling constant free from intermolecular effects 1J0(11B19F) was obtained for each temperature. In contrast to previous investigations, the final results indicate a nonlinear dependence of 1J0(11B19F) on temperature. In the corresponding ab initio calculations of spin–spin coupling constants performed at the coupled cluster singles and doubles (CCSD) level to obtain a reliable result for this coupling constant we had to take into account large vibrational corrections. Copyright © 2009 John Wiley & Sons, Ltd.
New saponins from Sechium mexicanum
Authors: Hernández‐Carlos Beatriz , Carmona‐Pineda Miriam , Villanueva‐Cañongo Claudia , López‐Olguín Jesús F. , Aragón‐García Agustín , Joseph‐Nathan Pedro
Published: July 2009

The chemical study of Sechium mexicanum roots led to the isolation of the two new saponins {3‐O‐β‐D‐glucopyranosyl (1 → 3)‐β‐D‐glucopyranosyl‐2β,3β,16α,23‐tetrahydroxyolean‐12‐en‐28‐oic acid 28‐O‐α‐L‐rhamnopyranosyl‐(1 → 3)‐β‐D‐xylopyranosyl‐(1 → 4)‐α‐L‐rhamnopyranosyl‐(1 → 2)‐α‐L‐arabinopyranoside} (1) and {3‐O‐β‐D‐glucopyranosyl (1 → 3)‐β‐D‐glucopyranosyl‐2β,3β,16α,23‐tetrahydroxyolean‐12‐en‐28‐oic acid 28‐O‐α‐L‐rhamnopyranosyl‐(1 → 3)‐β‐D‐xylopyranosyl‐(1 → 4)‐[β‐D‐apiosyl‐(1 → 3)]‐α‐L‐rhamnopyranosyl‐(1 → 2)‐α‐L‐arabinopyranoside} (2), together with the known compounds {3‐O‐β‐D‐glucopyranosyl‐(1 → 3)‐β‐D‐glucopyranosyl‐2β,3β,6β,16α,23‐pentahydroxyolean‐12‐en‐28‐oic acid 28‐O‐α‐L‐rhamnopyranosyl‐(1 → 3)‐β‐D‐xylopyranosyl‐(1 → 4)‐α‐L‐rhamnopyranosyl‐(1 → 2)‐α‐L‐arabinopyranoside} (3), tacacosides A1 (4) and B3 (5). The structures of saponins 1 and 2 were elucidated using a combination of 1H and 13C 1D‐NMR, COSY, TOCSY, gHMBC and gHSQC 2D‐NMR, and FABMS of the natural compounds and their peracetylated derivates, as well as by chemical degradation. Compounds 1–3 are the first examples of saponins containing polygalacic and 16‐hydroxyprotobasic acids found in the genus Sechium, while 4 and 5, which had been characterized partially by NMR, are now characterized in detail. Copyright © 2009 John Wiley & Sons, Ltd.
Three‐dimensional transient thermo‐hydro‐mechanical fundamental solutions of unsaturated soils
Authors: Maghoul Pooneh , Gatmiri Behrouz , Duhamel Denis
Published: July 2009

The governing differential equations of unsaturated soils considering the thermo‐poro‐mechanical behaviour consist of equilibrium, moisture air and heat transfer equations. In this paper at first, following some necessary simplifications, the thermal three‐dimensional fundamental solution for an unsaturated deformable porous medium with linear elastic behaviour in Laplace transform domain is presented. Subsequently, the closed‐form time domain fundamental solutions are derived by analytical inversion of the Laplace transform domain solutions. Then a set of numerical results are presented, which demonstrate the accuracies and some salient features of the derived analytical transient fundamental solutions. Finally, the closed‐form time domain fundamental solution will be verified mathematically by comparison with the previously introduced corresponding fundamental solution. Copyright © 2009 John Wiley & Sons, Ltd.
An integrated electric power supply chain and fuel market network framework: Theoretical modeling with empirical analysis for New England
Authors: Liu Zugang , Nagurney Anna
Published: July 2009

In this article, we develop a novel electric power supply chain network model with fuel supply markets that captures both the economic network transactions in energy supply markets and the physical network transmission constraints in the electric power network. The theoretical derivation and analysis are done using the theory of variational inequalities. We then apply the model to a specific case, the New England electric power supply chain, consisting of six states, five fuel types, 82 power generators, with a total of 573 generating units, and 10 demand market regions. The empirical case study demonstrates that the regional electric power prices simulated by our model match the actual electricity prices in New England very well. We also compute the electric power prices and the spark spread, an important measure of the power plant profitability, under natural gas and oil price variations. The empirical examples illustrate that in New England, the market/grid‐level fuel competition has become the major factor that affects the influence of the oil price on the natural gas price. Finally, we utilize the model to quantitatively investigate how changes in the demand for electricity influence the electric power and the fuel markets from a regional perspective.

The theoretical model can be applied to other regions and multiple electricity markets under deregulation to quantify the interactions in electric power/energy supply chains and their effects on flows and prices. © 2009 Wiley Periodicals, Inc. Naval Research Logistics, 2009