bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of epitaxial strain on the magneto-electric coupling of YMnO3 thin films
Authors: Singh A. K. , Snure M. , Tiwari A. , Patnaik S.
Published: July 2009

We report synthesis of phase pure multiferroic YMnO3 thin films on sapphire (0001) with conducting ZnGaO buffer contact layer. Films were prepared by using pulsed laser deposition technique and characterized using x-ray diffraction, scanning electron microscopy, energy dispersive absorption spectroscopy, and magnetic field dependent dielectric measurement techniques. Structural characterizations indicated phase purity and epitaxial nature of the films. The dielectric response indicated an anomaly in dielectric constant ε and tan δ in the vicinity of 30 K, well below the bulk Néel temperature ∼70 K. This anomaly in ε and tan δ and its magnetic field dependence is explained as an influence of strain due to lattice mismatch between the substrate and YMnO3 film. A substantial enhancement in magnetocapacitance was also observed for magnetic field applied parallel to ab plane of the film. Our results show that it is possible to tune the multiferroic property of YMnO3 via changes in ferroelastic route.
Probing carrier injection into pentacene field effect transistor by time-resolved microscopic optical second harmonic generation measurement
Authors: Nakao Motoharu , Manaka Takaaki , Weis Martin , Lim Eunju , Iwamoto Mitsumasa
Published: July 2009

By probing optical second harmonic generation (SHG) signals enhanced around the injection electrode, the carrier injection mechanism of top-contact pentacene field-effect transistors (FETs) was investigated in terms of Schottky injection. At the Au source electrode, the SHG signal disappeared immediately after applying the driving voltage: the applied external electric field was cancelled by the space charge field formed by holes accumulated in the FET channel. At the Ag source electrode, the SH intensity decayed slowly. Its dependence on the device operation voltage suggested that the electric field was not relaxed by injected holes. The Schottky effect regulated carrier injection. The space charge field effect attributable to accumulated holes contributed to the carrier injection.
Complex multireference configuration interaction calculations employing a coupled diabatic representation for the Πg2 resonance states of N2−
Authors: Honigmann Michael , Buenker Robert J. , Liebermann Heinz-Peter
Published: July 2009

Complex multireference configuration interaction calculations have been carried out for the lowest resonance states of Πg2 symmetry of the N2− molecule. It is shown that there is a forbidden crossing between the two lowest roots of this symmetry and that a satisfactory calculation of vibrational levels and cross sections therefore requires inclusion of both states and the coupling between them. A diabatic representation for the two Πg2 states was determined and vibronic calculations of the cross sections for vibrational excitation were carried out with a two-dimensional complex variational program.
Proposed hole-target for improving maximum proton energy driven by a short intense laser pulse
Authors: Pae K. H. , Choi I. W. , Hahn S. J. , Cary J. R. , Lee J.
Published: July 2009

By using particle-in-cell simulations, a new method for energetic collimated proton generation via intense short pulse laser-thin foil interactions is presented. To enhance the electron heating efficiency, a small hole is bored at the center of a thin foil target. The small hole combines target heating mechanisms effectively, which results in a high proton maximum energy. While an ultraintense, ultrashort laser pulse propagates through a small hole (diameter<laser spot size), the laser pulse drives electrons pulled out from the hole inner wall effectively inside the hole. When these electrons leave the target, a strong sheath field is formed between the electrons and the target rear surface and this accelerates protons from the rear surface of the target. The effective combination of the laser longitudinal ponderomotive force with the transverse heating (by E field) mechanism results in highly efficient electron heating of the hole target. When the rear part of the hole is filled with a proton-electron contamination layer, energetic collimated protons are produced. The scaling of the maximum proton energy of a hole target over a wide range of laser pulse intensities is presented and compared with that of a simple planar target.
Entropy of mixing for AgxIn1−x and AgxSn1−x liquid binary alloys
Authors: Bhuiyan G. M. , Alam Md. Saiful , Ahmed A. Z. Ziauddin , Syed Ishtiaque M. , Rashid R. I. M. A.
Published: July 2009

The entropy of mixing for AgxIn1−x and AgxSn1−x liquid binary alloys has been systematically investigated by using the perturbation theory. The interionic interactions as one of the basic ingredients are described by a local model pseudopotential. Since the metals forming the concerned alloys are less simple in nature the effect of the sp-d hybridization is appropriately taken into account through the interionic interactions. Results of our calculations across the full range of Ag concentrations are found to be good in agreement with the available experimental data.
Influence of surfactant solubility on the deformation and breakup of a bubble or capillary jet in a viscous fluid
Authors: Young Y.-N. , Booty M. R. , Siegel M. , Li J.
Published: July 2009

In a previous study [M. Hameed et al., J. Fluid Mech. 594, 307 (2008)] the authors investigated the influence of insoluble surfactant on the evolution of a stretched, inviscid bubble surrounded by a viscous fluid via direct numerical simulation of the Navier–Stokes equations, and showed that the presence of surfactant can cause the bubble to contract and form a quasisteady slender thread connecting parent bubbles, instead of proceeding directly toward pinch-off as occurs for a surfactant-free bubble. Insoluble surfactant significantly retards pinch-off and the thread is stabilized by a balance between internal pressure and reduced capillary pressure due to a high concentration of surfactant that develops during the initial stage of contraction. In the present study we investigate the influence of surfactant solubility on thread formation. The adsorption-desorption kinetics for solubility is in the diffusion controlled regime. A long-wave model for the evolution of a capillary jet is also studied in the Stokes flow limit, and shows dynamics that are similar to those of the evolving bubble. With soluble surfactant, depending on parameter values, a slender thread forms but can pinch-off later due to exchange of surfactant between the interface and exterior bulk flow.
Backward high energy ion beams from plasma focus
Authors: Roshan M. V. , Lee P. , Lee S. , Talebitaher A. , Rawat R. S. , Springham S. V.
Published: July 2009

High energy neutrons, more than 2.45 MeV from deuteron-deuteron fusion reaction, have been measured in backward direction of plasma focus devices in many laboratories. However the experimental evidence for high energy deuterons responsible for such neutrons has not been reported so far. In this brief communication, backward high energy deuteron beam from NX2 plasma focus [M. V. Roshan et al., Phys. Lett. A 373, 851 (2009)] is reported, which was measured with a direct and unambiguous technique of nuclear activation. The relevant nuclear reaction for the target activation is C12(d,n)N13, which has a deuteron threshold energy of 328 keV.
Cytokine and anti-cytokine therapy in asthma: ready for the clinic?
Authors: Desai D , Brightling C
Published: July 2009

Asthma is a common disease with an increasing prevalence worldwide. Up to 10% of these patients have asthma that is refractory to current therapy. This group have a disproportionate use of health care resources attributed to asthma, have significant morbidity and mortality and therefore represent an unmet clinical need. Asthma is a complex heterogeneous condition that is characterized by typical symptoms and disordered airway physiology set against a background of airway inflammation and remodelling. The inflammatory process underlying asthma is co-ordinated by a cytokine network. Modulating this network with biological therapy presents a new paradigm for asthma treatment. Clinical trials undertaken to date have underscored the complexity of the inflammatory profile and its relationship to the clinical features of the disease and have raised the importance of safety considerations related to these novel therapies. T helper type 2 cytokine blockade remains the most promising strategy, with anti-interleukin-5 reducing asthma exacerbations. Although anti-cytokine therapy is not yet ready for the clinic, the long-awaited possibility of new treatments for severe asthma is moving ever closer.
T-bet and pSTAT-1 expression in PBMC from coeliac disease patients: new markers of disease activity
Authors: Frisullo G , Nociti V , Iorio R , Patanella A K , Plantone D , Bianco A , Marti A , Cammarota G , Tonali P A , Batocchi A P
Published: July 2009

Coeliac disease (CD) is considered a T cell-mediated autoimmune disease, and up-regulation of T-bet and phosphorylated signal transducers and activators of transcription (pSTAT)1, key transcription factors for the development of T helper type 1 (Th1) cells, has been described in the mucosa of patients with untreated CD. Using transcription factor analysis, we investigated whether T-bet and pSTAT1 expressions are up-regulated in the peripheral blood of CD patients and correlate with disease activity. Using flow cytometry, we analysed T-bet, pSTAT1 and pSTAT3 expression in CD4+, CD8+ T cells, CD19+ B cells and monocytes from peripheral blood of 15 untreated and 15 treated CD patients and 30 controls, and longitudinally in five coeliac patients before and after dietary treatment. We evaluated using enzyme-linked immunosorbent assay (ELISA), interferon (FN)-γ, interleukin (IL)-17 and IL-10 production by peripheral blood mononuclear cell (PBMC) cultures. T-bet expression in CD4+, CD8+ T cells, CD19+ B cells and monocytes and IFN-γ production by PBMC was higher in untreated than in treated CD patients and controls. pSTAT1 expression was higher in CD4+T cells, B cells and monocytes from untreated than from treated CD patients and controls. pSTAT3 was increased only in monocytes from untreated patients compared with CD-treated patients and controls. The data obtained from the longitudinal evaluation of transcription factors confirmed these results. Flow cytometric analysis of pSTAT1 and T-bet protein expression in peripheral blood mononuclear cells could be useful and sensible markers in the follow-up of CD patients to evaluate disease activity and response to dietary treatment.
The Performance of Group‐affiliated Firms during Institutional Transition: A Longitudinal Study of Indian Firms
Authors: Zattoni Alessandro , Pedersen Torben , Kumar Vikas
Published: July 2009

Manuscript Type:Empirical

Research Question/Issue:Institutional and transaction cost theories highlight the idea that group‐affiliated firms outperform unaffiliated firms in emerging economies. However, the persistence of superior performance among group‐affiliated firms could be challenged by the recent, quick development of markets and institutions in these countries. This article explores the link between firm performance and the evolution of the institutional environment.

Research Findings/Insights:We analyze how business group affiliation affected firm performance in India in the post‐reform era, i.e., from 1990 to 2006. Our findings show that: (1) the performance benefits of group affiliation are evident in the early phase of institutional transition, but level out in the late phase; (2) older group‐affiliated firms are better able to cope with institutional transition than younger group‐affiliated firms; and (3) group‐affiliated service firms are better able to cope with institutional transition than group‐affiliated manufacturing firms.

Theoretical/Academic Implications:Our findings support institutional and transaction cost theories, as they show that: (1) when labor, capital, and products markets are characterized by large imperfections and weak supporting institutions business groups outperform independent companies; (2) when markets become more efficient and institutions grow stronger group‐affiliated firms fail to show continued superior performance; and (3) heterogeneity among member firms may influence the appropriation of the benefits arising from group affiliation. These findings expand the traditional understanding of the relationship between firm performance and the institutional context in emerging economies, and provide further support for the idea that the relative performance of group‐affiliated firms is contingent upon the characteristics of the institutional context and their particular features.

Practitioner/Policy Implications:The article has implications for managers and policy makers. Managers of business groups should adapt the timing of strategies to the evolution of the institutional environment. Policy makers should focus on the consequences of their policies, as they may undermine the efficiency of large national companies.
On Sustainable Pay‐as‐You‐Go Contribution Rules
Authors: DEMANGE GABRIELLE
Published: July 2009

An unfunded social security system faces the major risk, sometimes referred to as “political risk,” that future generations do not agree to contribute as much as expected. In order to account properly for this risk, the paper considers a political process in which the support to the system is asked from each new born generation. The analysis is conducted in an overlapping generations economy that is subject to macroeconomic shocks. As a consequence, the political support varies with the evolution of the economy. The impact of various factors—intragenerational redistribution, risk aversion, financial markets, governmental debt—on the political sustainability of a pay‐as‐you‐go system is discussed.
Inequality, Growth, and the Dynamics of Social Segmentation
Authors: KEMPF HUBERT , MOIZEAU FABIEN
Published: July 2009

In this paper, we investigate the link between the dynamics of society segmentation into communities and the growth process, based on a simple human capital growth model. Using coalition theory, we study the socioeconomic dynamics of an economy over time, characterize it and prove that the economy converges to a steady state partition that may be segmented. Eventually the whole economy tends to a balanced growth path, exhibiting persistent inequality in the case of segmentation. We then provide sufficient conditions on initial inequality and the technology parameters generating local and global externalities for obtaining a segmented society in the long run. On the whole, the relationship between inequality and growth cannot be assessed without taking into consideration the stratification phenomena at work in society over time.
Announcement or Contribution? The Relative Efficiency of Manipulated Lindahl Mechanisms
Authors: HASHIMZADE NIGAR , MYLES GARETH D.
Published: July 2009

The private provision mechanism is individually incentive compatible but inefficient. The Lindahl mechanism is efficient but not incentive compatible. We analyze the outcome of the manipulated Lindahl mechanism. When the demand announcements of participants are unrestricted the Lindahl mechanism suffers from multiple equilibria. If the government removes the multiplicity by restricting the functional form of announcements the resulting Lindahl equilibrium can be made approximately efficient. Approximate efficiency is achieved by announcements that are one‐dimensional regardless of the number of participants in the mechanism. This is in contrast to mechanisms that achieve exact efficiency but require announcements whose dimensionality increases at the same rate as the number of participants. The mechanism we describe benefits from simplicity at the cost of approximate efficiency. We demonstrate that mechanisms in which a linear demand function is announced are supermodular so play will converge to the Nash equilibrium for a range of learning dynamics.
SOURCES OF REAL EXCHANGE RATE FLUCTUATIONS: EMPIRICAL EVIDENCE FROM NINE AFRICAN COUNTRIES
Authors: AHMAD A. H. , PENTECOST ERIC J.
Published: July 2009

We investigate the sources of real exchange rate fluctuations in a sample of nine African countries from 1980:01 to 2005:04, using a trivariate structural vector autoregression. The analysis is motivated by a stochastic sticky‐price model from which three shocks are identified; demand, supply and monetary shocks. The results indicate that demand shocks are the predominant source of real exchange rate movements in these countries, although nominal shocks have also played a small but significant role in South Africa and Botswana, and supply shocks seem to be of some relevance for Algeria, Egypt and Tanzania.
GLOBAL ASYMMETRIES IN MONETARY POLICY OPERATIONS: DEBTOR CENTRAL BANKS OF THE MENA REGION
Authors: SCHNABL GUNTHER , SCHOBERT FRANZISKA
Published: July 2009

We analyse the monetary policy operations of central banks in the Middle East and North Africa. We distinguish liquidity‐providing central banks of large industrialized countries (creditor central banks) and liquidity‐absorbing central banks of emerging market economies (debtor central banks). Many debtor central banks provide liquidity through foreign exchange intervention as well as by fiscal financing and financial restructuring. If the resulting liquidity creation is regarded as excessive, liquidity is absorbed through sterilization operations such as reserve requirements and (to a limited extent) open market operations. Some central banks coordinate their liquidity management with the fiscal authorities.
Growth and fructan content of plants of Vernonia herbacea (Asteraceae) regenerated from rhizophores
Authors: DE CARVALHO M. ANGELA MACHADO , ZAIDAN LILIAN B. P. , DIETRICH SONIA M. C.
Published: July 2009

The growth and fructan contents of plants of Vernonia herbacea (Veil.) Rusby regenerated from fragments of the underground organ (rhizophore) were analysed during two developmental cycles. When cultivated away from their natural ecosystem, these plants went through the same phenological phases as those naturally grown in the cerrado. The first aerial shoots started developing from initial fragments before the new underground system, the former acting as the main metabolic sink for the fructan present in the initial fragments. The new rhizophores started to develop by the sixth month, as photosynthates were transformed into fructans. Growth parameters measured reached higher values in the second growth cycle, exhibiting growth curves synchronized with those obtained for fructan contents in the new rhizophores. Fructo‐oligosaccharides were available mostly during the period of fast growth of aerial organs whilst the fructo‐polysaccharides were reduced. Fructan variation indicates that these compounds are metabolized during development. Additionally, the rapid growth, intense production of rhizophores and high fructan content make Vernonia herbacea a promising source of fructan for commercial use.
Postmortem Detection of Hepatitis B, C, and Human Immunodeficiency Virus Genomes in Blood Samples from Drug‐Related Deaths in Denmark*
Authors: Eriksen Mette Brandt , Jakobsen Marianne Antonius , Kringsholm Birgitte , Banner Jytte , Thomsen Jørgen L. , Georgsen Jørgen , Pedersen Court , Christensen Peer Brehm
Published: July 2009

Abstract:  Blood‐borne viral infections are widespread among injecting drug users; however, it is difficult to include these patients in serological surveys. Therefore, we developed a national surveillance program based on postmortem testing of persons whose deaths were drug related. Blood collected at autopsy was tested for anti‐HBc, anti‐HBs, anti‐hepatits C virus (HCV), or anti‐human immunodeficiency virus (HIV) antibodies using commercial kits. Subsets of seropositive samples were screened for viral genomes using sensitive in‐house and commercial polymerase chain reaction (PCR) assays. Hepatitis B virus (HBV) DNA was detected in 20% (3/15) of anti‐HBc‐positive/anti‐HBs‐negative samples, HCV RNA was found in 64% (16/25) of anti‐HCV‐positive samples, and HIV RNA was detected in 40% (6/15) of anti‐HIV‐positive samples. The postmortem and antemortem prevalences of HBV DNA and HCV RNA were similar. Postmortem HIV RNA testing was less sensitive than antemortem testing. Thus, postmortem PCR analysis for HBV and HBC infection is feasible and relevant for demonstrating ongoing infections at death or for transmission analysis during outbreaks.
Implementing digital technology to enhance student learning of pathology
Authors: Farah C. S. , Maybury T.
Published: July 2009

Introduction:  The introduction of digital technologies into the dental curriculum is an ongoing feature of broader changes going on in tertiary education. This report examines the introduction of digital virtual microscopy technology into the curriculum of the School of Dentistry at the University of Queensland (UQ) in Brisbane, Australia.

Methods and materials:  Sixty students studying a course in pathology in 2005 were introduced to virtual microscopy technology alongside the more traditional light microscope and then asked to evaluate their own learning outcomes from this technology via a structured 5‐point LIKART survey.

Results:  A wide variety of questions dealing the pedagogic implications of the introduction of virtual microscopy into pathology were asked of students with the overall result being that it positively enhanced their learning of pathology via digital microscopic means.

Discussion:  The success of virtual microscopy in dentistry at UQ is then discussed in the larger context of changes going on in tertiary education. In particular, the change from the print‐literate tradition to the electronic one, that is from ‘literacy to electracy’. Virtual microscopy is designated as a component of this transformation to electracy.

Conclusion:  Whilst traditional microscopic skills may still be valued in dental curricula, the move to virtual microscopy and computer‐assisted, student‐centred learning of pathology appears to enhance the learning experience in relation to its effectiveness in helping students engage and interact with the course material.
Oral manifestations in human immunodeficiency virus infected children in highly active antiretroviral therapy era
Authors: Dos Santos Pinheiro Raquel , França Talita Tenório , Ribeiro Camila Maria Beder , Leão Jair Carneiro , De Souza Ivete Pomarico Ribeiro , Castro Gloria Fernanda
Published: July 2009

Objective:  Conducted a literature review to identify studies that reported on the oral manifestations in human immunodeficiency virus (HIV) infected children in highly active antiretrovial therapy (HAART) era.

Methods:  A search electronic data base were used and the terms used were ‘oral lesions’ and ‘oral manifestations’. The studies of prevalence of oral manifestation in children with HIV worldwide, descriptive studies, case reports, studies on the association of oral lesions and levels of immune suppression, use of HAART and transmission of HIV were included.

Results:  There have been substantial changes in the management of HIV disease, especially in the past decade because of the use of HAART. However, children are still being infected and present some peculiarities when compared with adults. Molecular epidemiology, transmission and therapy of the common opportunistic oral infections of HIV disease need to be better understood as a consequence of improved anti‐HIV strategies. Treatment with HAART improves the immune function and decreases mortality, morbidity, and opportunistic infections in HIV‐infected persons.

Conclusion:  The frequency and severity of oral disease associated with HIV infection have reduced considerably, although the use of HAART may be associated with an increased appearance of oral lesions associated with human papillomavirus and potentially increase the risk of later oral squamous cell carcinoma.
Innateness, Learning, and Rationality
Authors: Spelke Elizabeth S. , Kinzler Katherine D.
Published: July 2009

Abstract— J. P. Spencer et al. (2009) ask readers to reject the nativist–empiricist dialogue and adopt a new theoretical perspective on cognition, focusing on “developmental process.” This commentary argues that the dialogue between nativism and empiricism is a rich source of insight into the nature and development of human knowledge. Indeed, the dialogue is entering a new and exciting phase, in which new methods of controlled rearing and of cognitive neuroscience, and new conceptual tools for understanding learning, allow exploration of how human concepts emerge through the interaction of innate cognitive structures shaped by natural selection, with statistical learning processes shaped by specific encounters with the world. This approach fosters new, interdisciplinary research that promises to increase dramatically understanding of human knowledge.
Telomerase activity and telomere length in acute leukemia: correlations with disease progression, subtypes and overall survival
Authors: WANG Y. , FANG M. , SUN X. , SUN J.
Published: July 2009

The progressive shortening of telomeres and the activation of telomerase are considered to be one of the important mechanisms in cellular immortalization and disease progression. Bone marrow samples were collected from 148 patients with acute leukemia (AL). Based on the stage of the disease, patients were divided into the newly diagnosed group, the relapsed group and the complete remission (CR) group. telomerase activity (TA) was examined by PCR‐ELISA, and telomere length (TL) was examined by Southern blot analyses. TA and TL were analyzed in relation to AL stage and subtype. Five‐year survival was analyzed using Kaplan–Meier survival curve. TA in AL patients was higher than healthy individuals. TA level was the highest in the relapsed group, followed by the newly diagnosed group, and then the CR group. TA had no difference between acute nonlymphocytic leukemia (ANLL) group and acute lymphocytic leukemia (ALL) group. But TA in group of subtype M3 was lower than other subtypes of ANLL. TL in AL group was shorter than the control group. TL was the shortest in the relapsed group, followed by the newly diagnosed group, and finally the CR group. TL exhibited an inverse correlation with TA. The group of patients with high TA had a significantly poorer five‐year‐survival than that of low TA group. TA is elevated and TL is shortened in AL patients. There is a significant inverse correlation between TL and TA. Patients in late‐stage disease had shorter TL and higher TA than those in early stages. The shortened TL and elevated TA correlated with disease progression and relapse, and they may serve as prognostic factors for AL patients with poor outcome. M3 subtype is special with relative lower TA and long‐lasting survival than other subtypes.
Auditory evoked potentials in a stranded Gervais’ beaked whale (Mesoplodon europaeus)
Authors: Finneran James J. , Houser Dorian S. , Mase-Guthrie Blair , Ewing Ruth Y. , Lingenfelser Robert G.
Published: July 2009

Efforts to identify the specific causal mechanisms responsible for beaked whale strandings coincident with naval exercises have been hampered by lack of data concerning the hearing abilities of beaked whales and their physiological and behavioral responses to sound. In this study, auditory capabilities of a stranded Gervais’ beaked whale (Mesoplodon europaeus) were investigated by measuring auditory evoked potentials. Click-evoked potentials, auditory thresholds as a function of frequency, and the modulation rate transfer function were determined. The evoked potentials and modulation rate transfer function were similar to those measured in other echolocating odontocetes; the upper limit of functional hearing was 80–90 kHz.
Investigating the effects of stimulus duration and context on pitch perception by cochlear implant users
Authors: Stohl Joshua S. , Throckmorton Chandra S. , Collins Leslie M.
Published: July 2009

Cochlear implant sound processing strategies that use time-varying pulse rates to transmit fine structure information are one proposed method for improving the spectral representation of a sound with the eventual goal of improving speech recognition in noisy conditions, speech recognition in tonal languages, and music identification and appreciation. However, many of the perceptual phenomena associated with time-varying rates are not well understood. In this study, the effects of stimulus duration on both the place and rate-pitch percepts were investigated via psychophysical experiments. Four Nucleus CI24 cochlear implant users participated in these experiments, which included a short-duration pitch ranking task and three adaptive pulse rate discrimination tasks. When duration was fixed from trial-to-trial and rate was varied adaptively, results suggested that both the place-pitch and rate-pitch percepts may be independent of duration for durations above 10 and 20ms, respectively. When duration was varied and pulse rates were fixed, performance was highly variable within and across subjects. Implications for multi-rate sound processing strategies are discussed.
CONTROLLING THE UNCERTAIN MULTI-SCROLL CRITICAL CHAOTIC SYSTEM WITH INPUT NONLINEAR USING SLIDING MODE CONTROL
Authors: WANG XINGYUAN , LIN DA , WANG ZHANJIE
Published: July 2009

In this paper, control of the uncertain multi-scroll critical chaotic system is studied. According to variable structure control theory, we design the sliding mode controller of the uncertain multi-scroll critical chaotic system, which contains sector nonlinearity and dead zone inputs. For an arbitrarily given equilibrium point of the uncertain multi-scroll chaotic system, we achieve global stabilization for the equilibrium points. Particularly, a class of proportional integral (PI) switching surface is introduced for determining the convergence rate. Furthermore, the proposed control scheme can be extended to complex multi-scroll networks. Finally, simulation results are presented to demonstrate the effectiveness of the proposed control scheme.
FUNCTIONALIZATION OF MULTI-WALLED CARBON NANOTUBES WITH CYSTEAMINE FOR THE CONSTRUCTION OF CNT/GOLD NANOPARTICLE HYBRID NANOSTRUCTURES
Authors: KUMAR NANJUNDAN ASHOK , KIM SUNG HUN , KIM JONG SU , KIM JONG TAE , JEONG YEON TAE
Published: July 2009

Combining hybrid nanostructures of metal nanoparticles (NPs) and carbon nanotubes could afford a novel strategy to prepare promising nanomaterials for the highly sensitive sensors and imaging science applications. Conventional acid oxidation process was used to obtain carboxylic acid bound multi-walled carbon nanotubes (MWNTs) which was further acylated with thionyl chloride to give acyl chloride functionalized MWNTs. Thiol functionalized MWNTs were synthesized by amidation reaction of the acylated MWNTs with cysteamine. Further, gold nanoparticles (GNPs) were successfully fabricated on the tube walls to yield the CNT/ Au hybrid. Fourier transform infrared spectroscopy and energy dispersive X-ray studies were used to characterize the surface chemical functionalities and composition of MWNTs, respectively. Evidence for the attachment of GNPs to thiol functionalized MWNTs was obtained from ultraviolet–visible absorption spectra. In addition, TEM images provided a vivid image of uniform decoration of GNPs on the nanotube sidewalls.
Low-overhead defect tolerance in crossbar nanoarchitectures
Authors: Tahoori Mehdi B.
Published: July 2009

It is anticipated that the number of defects in nanoscale devices fabricated using bottom-up self-assembly process is significantly higher than that for CMOS devices fabricated by conventional top-down lithography patterning. This is mainly because of inherent lack of control in self-assembly fabrication as well as atomic scale of devices. The goal of defect tolerance, as an integral part of nano computing, is to obtain error-free computation from such fabrics containing defective elements.

In this article, an application-independent defect tolerant scheme for reconfigurable crossbar array nanoarchitectures is presented. The main feature of this approach is that the existence and location of defective resources within the nano-fabric are hidden from the entire design flow, resulting in minimum post-fabrication customization per chip and minimum changes to the entire design and synthesis flow. It is also shown how to drastically minimize the area overhead associated with this flow. The proposed technique requires extraction of regular yet incomplete defect-free subsets, in contrast to previously proposed complete defect-free subsets. This can greatly reduce the area overhead required for defect tolerance while not sacrificing logic mapping or signal routing capabilities. Extensive simulation results confirm considerable reduction in the area overhead without any negative impact on the usability of modified defect-free subsets.
On the stability of the information carried by traffic flow features at the packet level
Authors: Este Alice , Gringoli Francesco , Salgarelli Luca
Published: July 2009

This paper presents a statistical analysis of the amount of information that the features of traffic flows observed at the packet-level carry, with respect to the protocol that generated them. We show that the amount of information of the majority of such features remain constant irrespective of the point of observation (Internet core vs. Internet edge) and to the capture time (year 2000/01 vs. year 2008). We also describe a comparative analysis of how four statistical classifiers fare using the features we studied.
Intra-arterial AICA-riboside administration induces NO-dependent vasodilation in vivo in human skeletal muscle
Authors: Bosselaar Marlies , Boon Hanneke , van Loon Luc J. C. , van den Broek Petra H. H. , Smits Paul , Tack Cees J.
Published: July 2009

In animal models, administration of the adenosine analog AICA-riboside has shown beneficial effects on ischemia-reperfusion injury and glucose homeostasis. The vascular and/or metabolic effects of AICA-riboside administration in humans remain to be established. AICA-riboside was infused intra-arterially in four different dosages up to 8 mg·min−1·dl−1 in 24 healthy subjects. Forearm blood flow (FBF) and glucose uptake and plasma glucose, free fatty acid, and AICA-riboside concentrations were assessed. We also combined AICA-riboside infusion (2 mg·min−1·dl−1) with the intra-arterial administration of the adenosine receptor antagonist caffeine (90 μg·min−1·dl−1; n = 6) and with the endothelial NO synthase inhibitor l-NMMA (0.4 mg·min−1·dl−1; n = 6). Additional in vitro experiments were performed to explain our in vivo effects of AICA-riboside in humans. AICA-riboside increased FBF dose dependently from 2.0 ± 0.2 to 13.2 ± 1.9 ml·min−1·dl−1 maximally ( P < 0.05 for all dosages). The latter was not reduced by caffeine administration but was significantly attenuated by l-NMMA infusion. Despite high plasma AICA-riboside concentrations, forearm glucose uptake did not change. In vitro experiments showed rapid uptake of AICA-riboside by the equilibrative nucleoside transporter in erythrocytes and subsequent phosphorylation to AICA-ribotide. We conclude that AICA-riboside induces a potent vasodilator response in humans that is mediated by NO. Despite high local plasma concentrations, AICA-riboside does not increase skeletal muscle glucose uptake.
A Truncated Descent HS Conjugate Gradient Method and Its Global Convergence
Authors: Cheng Wanyou , Zhang Zongguo
Published: July 2009

Recently, Zhang (2006) proposed a three‐term modified HS (TTHS) method for unconstrained optimization problems. An attractive property of the TTHS method is that the
direction generated by the method is always descent. This property is independent of the
line search used. In order to obtain the global convergence of the TTHS method, Zhang
proposed a truncated TTHS method. A drawback is that the numerical performance of the
truncated TTHS method is not ideal. In this paper, we prove that the TTHS method with
standard Armijo line search is globally convergent for uniformly convex problems. Moreover,
we propose a new truncated TTHS method. Under suitable conditions, global convergence is
obtained for the proposed method. Extensive numerical experiment show that the proposed
method is very efficient for the test problems from the CUTE Library.
Prostaglandin F2α-F-Prostanoid Receptor Signaling Promotes Neutrophil Chemotaxis via Chemokine (C-X-C Motif) Ligand 1 in Endometrial Adenocarcinoma
Authors: Wallace Alison E. , Sales Kurt J. , Catalano Roberto D. , Anderson Richard A. , Williams Alistair R.W. , Wilson Martin R. , Schwarze Jurgen , Wang Hongwei , Rossi Adriano G. , Jabbour Henry N.
Published: July 2009

The prostaglandin F2α (PGF2α) receptor (FP) is elevated in endometrial adenocarcinoma. This study found that PGF2α signaling via FP regulates expression of chemokine (C-X-C motif) ligand 1 (CXCL1) in endometrial adenocarcinoma cells. Expression of CXCL1 and its receptor, CXCR2, are elevated in cancer tissue compared with normal endometrium and localized to glandular epithelium, endothelium, and stroma. Treatment of Ishikawa cells stably transfected with the FP receptor (FPS cells) with 100 nmol/L PGF2α increased CXCL1 promoter activity, mRNA, and protein expression, and these effects were abolished by cotreatment of cells with FP antagonist or chemical inhibitors of Gq, epidermal growth factor receptor, and extracellular signal-regulated kinase. Similarly, CXCL1 was elevated in response to 100 nmol/L PGF2α in endometrial adenocarcinoma explant tissue. CXCL1 is a potent neutrophil chemoattractant. The expression of CXCR2 colocalized to neutrophils in endometrial adenocarcinoma and increased neutrophils were present in endometrial adenocarcinoma compared with normal endometrium. Conditioned media from PGF2α-treated FPS cells stimulated neutrophil chemotaxis, which could be abolished by CXCL1 protein immunoneutralization of the conditioned media or antagonism of CXCR2. Finally, xenograft tumors in nude mice arising from inoculation with FPS cells showed increased neutrophil infiltration compared with tumors arising from wild-type cells or following treatment of mice bearing FPS tumors with CXCL1-neutralizing antibody. In conclusion, our results show a novel PGF2α-FP pathway that may regulate the inflammatory microenvironment in endometrial adenocarcinoma via neutrophil chemotaxis. [Cancer Res 2009;69(14):5726–33]
Beneficial Impact of Xuezhikang on Cardiovascular Events and Mortality in Elderly Hypertensive Patients With Previous Myocardial Infarction From the China Coronary Secondary Prevention Study (CCSPS)
Authors: Li Jian‐Jun , Lu Zong‐Liang , Kou Wen‐Rong , Chen Zuo , Wu Yang‐Feng , Yu Xue‐Hai , Zhao Yu‐Cheng ,   On behalf of the Chinese Coronary Secondary Prevention Study Group
Published: July 2009

Coronary heart disease, hypertension, and dyslipidemia are highly prevalent and commonly coexist in people who are middle‐aged and older. Previous data suggested that lowering cholesterol concentrations in individuals at high risk of cardiovascular disease improved clinical outcomes. Xuezhikang, a partial extract of red yeast rice containing statin, has a marked impact on lipids. The purpose of this study, therefore, was to evaluate the impact of Xuezhikang on reducing cardiovascular events and mortality in elderly Chinese hypertensive patients with a history of myocardial infarction (MI) enrolled in the Chinese Coronary Secondary Prevention Study. In this randomized trial, 1530 elderly hypertensive patients (≥65 years old) with previous MI were assigned either to placebo (n = 758) or to Xuezhikang (n = 772) daily for an average of 4.5 years. The primary endpoint was recurrent coronary events; the secondary endpoint was all‐cause mortality and other clinical events, including adverse effects. There were 68 cases of coronary events (8.8%) detected in the Xuezhikang group and 108 cases (14.3%) in the placebo group (38.2% risk reduction by Xuezhikang therapy). Death from coronary heart disease (CHD) totaled 49 cases in the Xuezhikang group (6.4%) and 68 cases in the placebo group (9.0%), indicating that Xuezhikang significantly decreased the risk of CHD death by 29.2%. Our study demonstrated that Xuezhikang therapy could effectively and safely reduce cardiovascular events and all‐cause death in Chinese elderly hypertensive patients with previous MI. This finding may have an important implication for the treatment of elderly hypertensive patients with CHD.
Compounding Parenteral Nutrition: Reducing the Risks
Authors: Curtis Caitlin , Sacks Gordon S.
Published: July 2009

Compounding parenteral nutrition, either manually or with an automated compounding device, requires aseptic conditions and trained personnel. The revised version of United States Pharmacopeia Chapter <797> is a comprehensive document that describes standards and procedures to minimize the risk of contamination of compounded parenteral products. The chapter includes evidence‐based instructions for pharmacy design, washing, garbing, cleaning, quality assurance, and personnel training and evaluation designed to improve compounding practices in all pharmacies that compound parenteral products. Because parenteral nutrition is a compounded product mixed from multiple additives, it is important to maintain these standards, especially when using an automated compounding device. This article is an overview of United States Pharmacopeia Chapter <797>, with special emphasis on parenteral nutrition.
Combination therapy with normobaric oxygen (NBO) plus thrombolysis in experimental ischemic stroke
Authors: Fujiwara Norio , Murata Yoshihiro , Arai Ken , Egi Yasuhiro , Lu Jie , Wu Ona , Singhal Aneesh B , Lo Eng H
Published: July 2009

Background

The widespread use of tissue plasminogen activator (tPA), the only FDA-approved acute stroke treatment, remains limited by its narrow therapeutic time window and related risks of brain hemorrhage. Normobaric oxygen therapy (NBO) may be a useful physiological strategy that slows down the process of cerebral infarction, thus potentially allowing for delayed or more effective thrombolysis. In this study we investigated the effects of NBO started simultaneously with intravenous tPA, in spontaneously hypertensive rats subjected to embolic middle cerebral artery (MCA) stroke. After homologous clot injection, animals were randomized into different treatment groups: saline injected at 1 hour; tPA at 1 hour; saline at 1 hour plus NBO; tPA at 1 hour plus NBO. NBO was maintained for 3 hours. Infarct volume, brain swelling and hemorrhagic transformation were quantified at 24 hours. Outcome assessments were blinded to therapy.

Results

Upon clot injection, cerebral perfusion in the MCA territory dropped below 20% of pre-ischemic baselines. Both tPA-treated groups showed effective thrombolysis (perfusion restored to nearly 100%) and smaller infarct volumes (379 ± 57 mm3 saline controls; 309 ± 58 mm3 NBO; 201 ± 78 mm3 tPA; 138 ± 30 mm3 tPA plus NBO), showing that tPA-induced reperfusion salvages ischemic tissue and that NBO does not significantly alter this neuroprotective effect. NBO had no significant effect on hemorrhagic conversion, brain swelling, or mortality.

Conclusion

NBO can be safely co-administered with tPA. The efficacy of tPA thrombolysis is not affected and there is no induction of brain hemorrhage or edema. These experimental results require clinical confirmation.
Validity and reliability of a new, short symptom rating scale in patients with persistent atrial fibrillation
Authors: Härdén Marie , Nyström Britta , Kulich Károly , Carlsson Jonas , Bengtson Ann , Edvardsson Nils
Published: July 2009

Background

Symptoms related to atrial fibrillation and their impact on health-related quality of life (HRQoL) are often evaluated in clinical trials. However, there remains a need for a properly validated instrument. We aimed to develop and validate a short symptoms scale for patients with AF.

Methods

One hundred and eleven patients with a variety of symptoms related to AF were scheduled for DC cardioversion. The mean age was 67.1 ± 12.1 years, and 80% were men. The patients completed the new symptoms scale, the Toronto Symptoms Check List (SCL) and the generic Short Form 36 (SF-36) the day before the planned DC cardioversion. Compliance was excellent, with only 1 of 666 answers missing.

Results

One item, 'limitations in working capability', was deleted because of a low numerical response rate, as many of the patients were retired. The internal consistency reliability of the remaining six items was 0.81 (Cronbach's α). Patients scored highest in the items of 'dyspnoea on exertion', 'limitations in daily life due to AF' and 'fatigue due to AF', with scores of 4.5, 3.3 and 4.5, respectively. There was a good correlation to all relevant SF-36 domains and to the relevant questions of the SCL. The Rasch analyses showed that the items are unidimensional and that they are clearly separated and cover an adequate range. Test-retest reliability was performed in patients who failed DC and was adequate for three of six items, >0.70.

Conclusion

The psychometric characteristics of the new short symptoms scale were found to have satisfactory reliability and validity.
Book reviews
Authors: Whitehouse G. H.
Published: July 2009

This monograph from France describes the radiological appearances of two types of fracture, namely fatigue fractures occurring in normal bone and fractures secondary to the bone having acquired a diminished resistance. The latter group excludes pathological fractures which are superimposed on bone tumour or infection.
Evaluation of the processing functions of a digital subtraction angiography image processor
Authors: Maher K. P. , Malone J. F. , Hurley G. D. , McInerney D. P.
Published: July 2009

A large number of imaging systems for digital subtraction angiography (DSA) are now commercially available. Numerous evaluations of the performance of these systems have been reported in the literature. However systematic evaluations of the processing functions of DSA image processors have not been widely reported. Such an evaluation for one commercial system is presented in this paper. Functions evaluated include linear transformation, logarithmic transformation, integration, subtraction and temporal filtration. The observations indicate that image processing results are frequently achieved by indirect routes which compromise the fidelity of the image data.
The use of magnetic resonance imaging in the planning of iodine 125 therapy for melanoma of the choroid
Authors: Conard F. , Sealy R. , Hill J. , van Dyk B.
Published: July 2009

Iodine-125 plaques have been described in the treatment of melanoma of the choroid (Sealy et al, 1980), which have a protective shielding to screen the adjacent normal structures, such as the optic nerve and extraocular muscles. This can significantly reduce the morbidity of treatment. However, when a returned edge is used to shield adjacent structures, such as the optic nerve, there is a very sharp dose gradient at the edge of the plaque which is not seen with unscreened plaques containing cobalt 60. This implies that the position of the edge of the tumour needs to be accurately known to ensure that the whole of the tumour mass is adequately irradiated. Malignant melanoma of the choroid is often associated with a large retinal detachment which may make it difficult to assess the precise size of the tumour, although it can be appreciated that a tumour is present. We describe here a case where this difficulty was experienced and where assistance was obtained in determining the edge of the tumour by use of magnetic resonance imaging (MRI) scanning and study of the T  2 map.
Blindingly obvious
Authors: Tilley Elisabeth A. , Adam E. Jane , Joseph A. E. A.
Published: July 2009

A 55-year-old man presenting with a 4-week history of abdominal swelling was found to have hepatomegaly. An abdominal ultrasound scan was performed using a 3.5 MHz transducer and a longitudinal section through the right upper quadrant shown below (Fig. 1).
Book reviews
Authors: Kean D.
Published: July 2009

This is the third volume in a continuing series which aims to keep radiologists up to date in the very rapidly evolving and changing field of magnetic resonance imaging (MRI).