bluuebunny/crossref_metadata_2025 huggingface dataset:
Electronic structures of an epitaxial graphene monolayer on SiC(0001) after metal intercalation (metal = Al, Ag, Au, Pt, and Pd): A first-principles study
Authors: Hsu Chia-Hsiu , Lin Wen-Huan , Ozolins Vidvuds , Chuang Feng-Chuan
Published: February 2012

The atomic structures and electronic properties of metal-intercalated (metal = Al, Ag, Au, Pt, and Pd) graphene monolayers on SiC(0001) were investigated using first-principles calculations. The unique Dirac cone of graphene near the K point reappeared as the graphite layer was intercalated by these metals at a coverage of 3/8 ML. Furthermore, our results show that metal intercalation leads to n-type doping of graphene. The bands contributed from graphene exhibit small splitting after intercalation, whereas the bands contributed from the intercalated metal layer have significant Rashba spin-orbit splittings in all cases except Al.
Exchange effects on spin-dependent ac transport
Authors: Lan Jin , Sui Wen-Quan , Zhao Xuean
Published: February 2012

Spin-dependent ac transport problem is studied with exchange effects. Spin-spin exchange interaction and charge-charge Coulomb interaction are included simultaneously to determine the landscape of internal potential and the spin-dependent ac conductance. Gauge invariance and charge conservation are still satisfied. But spin current is not conserved. It is found that the exchange effects affect spin conductance dramatically, and hardly influence charge conductance. This shows the role of spin-accumulation in spin-dependent transport.
Accurate thermochemistry from a parameterized coupled-cluster singles and doubles model and a local pair natural orbital based implementation for applications to larger systems
Authors: Huntington Lee M. J. , Hansen Andreas , Neese Frank , Nooijen Marcel
Published: February 2012

We have recently introduced a parameterized coupled-cluster singles and doubles model (pCCSD(α, β)) that consists of a bivariate parameterization of the CCSD equations and is inspired by the coupled electron pair approximations. In our previous work, it was demonstrated that the pCCSD(−1, 1) method is an improvement over CCSD for the calculation of geometries, harmonic frequencies, and potential energy surfaces for single bond-breaking. In this paper, we find suitable pCCSD parameters for applications in reaction thermochemistry and thermochemical kinetics. The motivation is to develop an accurate and economical methodology that, when coupled with a robust local correlation framework based on localized pair natural orbitals, is suitable for large-scale thermochemical applications for sizeable molecular systems. It is demonstrated that the original pCCSD(−1, 1) method and several other pCCSD methods are a significant improvement upon the standard CCSD approach and that these methods often approach the accuracy of CCSD(T) for the calculation of reaction energies and barrier heights. We also show that a local version of the pCCSD methodology, implemented within the local pair natural orbital (LPNO) based CCSD code in ORCA, is sufficiently accurate for wide-scale chemical applications. The LPNO based methodology allows us for routine applications to intermediate sized (20–100 atoms) molecular systems and is a significantly more accurate alternative to MP2 and density functional theory for the prediction of reaction energies and barrier heights.
Parametric study of cylindrical converging shock waves generated based on shock dynamics theory
Authors: Zhai Zhigang , Si Ting , Luo Xisheng , Yang Jiming , Liu Cangli , Tan Duowang , Zou Liyong
Published: February 2012

In our previous work, the technique of generating cylindrical converging shock waves based on shock dynamics theory was proposed. In the present work, a further study is carried out to assess the influence of several parameters including the converging angle θ0, the incident planar shock Mach number M0, and the shock tube height h on the wall profile and the converging shock wave. Combining the high-speed schlieren photography and the numerical simulation with the shock dynamics theory, the characteristics of wall profiles, cylindrical converging shock waves, and thermodynamic properties for different controllable parameters are analyzed. It is found that these parameters have great effects on shapes of the wall profile and experimental investigation favors large values of M0 and h and moderate θ0. The experimental sequences of schlieren images indicate that the shocks moving in the converging part are of circular shapes, which further verifies the method in our previous work. In addition, the changes of the shock Mach number, pressure, temperature, and density are obtained quantitatively. The results show that higher pressure and temperature can be reached in the converging part at the same distance to the center of convergence for larger incident shock Mach numbers, larger shock tube heights, or smaller converging angles. All the database will be useful for understanding the shock focusing and further investigating the Richtmyer-Meshkov instability induced by the converging shock waves.
Analysis of time resolved femtosecond and femtosecond/picosecond coherent anti-Stokes Raman spectroscopy: Application to toluene and Rhodamine 6G
Authors: Niu Kai , Lee Soo-Y.
Published: February 2012

The third-order polarization for coherent anti-Stokes Raman scattering (CARS) from a pure state is described by 48 terms in perturbation theory, but only 4 terms satisfy the rotating wave approximation. They are represented by Feynman dual time-line diagrams and four-wave mixing energy level diagrams. In time-resolved (tr) fs and fs/ps CARS from the ground vibrational state, one resonant diagram, which is the typical CARS term, with three field interactions—pump, Stokes, followed by probe—on the ket is dominant. Using the separable, displaced harmonic oscillators approximation, an analytic result is obtained for the four-time correlation function in the CARS third-order polarization. Dlott's phenomenological expression for off-resonance CARS from the ground vibrational state is derived using a three-state model. We calculated the tr fs and fs/ps CARS for toluene and Rhodamine 6G (R6G), initially in the ground vibrational state, to compare with experimental results. The observed vibrational features and major peaks for both tr fs and fs/ps CARS, from off-resonance (for toluene) to resonance (for R6G) pump wavelengths, can be well reproduced by the calculations. The connections between fs/ps CARS, fs stimulated Raman spectroscopy, and impulsive stimulated scattering for toluene and R6G are discussed.
Folding of small origamis
Authors: Arbona Jean Michel , Aimé Jean-Pierre , Elezgaray Juan
Published: February 2012

A model that preserves the known thermodynamic properties of double stranded DNA is introduced to study the formation of more complex DNA constructions, such as small origamis or Holliday junctions. We show that the thermodynamic behaviour of these complex DNA constructions is not only given by their sequence but also by their topology.
Spontaneous formation of quantum height manganese gallium islands and atomic chains on N-polar gallium nitride(0001¯)
Authors: Chinchore Abhijit , Wang Kangkang , Shi Meng , Liu Yinghao , Smith Arthur R.
Published: February 2012

Deposition of manganese onto the gallium-rich, nitrogen-polar GaN(0001¯) surface results in the formation of quantum-height island structures. Two unique island heights differing by one atomic layer are observed, including 0.93 nm high islands which are unstable against the formation of 1.13 nm high islands. A row structure at the islands’ surface suggests a mixture of Mn and Ga, while growth of one-dimensional atomic chains at the surface of the stable 1.13 nm high islands indicates a strongly anisotropic diffusion. The observed behavior is consistent with a quantum size effect driven growth mechanism.
Efficient hybrid white polymer light-emitting devices with electroluminescence covered the entire visible range and reduced efficiency roll-off
Authors: Hu Sujun , Zhu Minrong , Zou Qinghua , Wu Hongbin , Yang Chuluo , Wong Wai-Yeung , Yang Wei , Peng Junbiao , Cao Yong
Published: February 2012

We report efficient hybrid white polymer light emitting devices (WPLEDs) fabricated via simple solution-proceeded process from a newly synthesized wide band-gap fluorene-co-dibenzothiophene-S,S-dioxide copolymer, which dually function as fluorescent blue emitter and host material for electrophosphorescent sky-blue, yellow, and saturated-red dyes. The Commission Internationale d’Énclairage coordinates of the best devices are (0.356, 0.334), with electroluminescence covered the entire visible light spectrum from 400 to 780 nm, resulting in a high color rendering index of 90. Incorporation of a bilayer electrode consisting of water/alcohol-soluble conjugated polymer and Al as electron-injection cathode boosts an enhancement of 50% in device efficiency, leading to external quantum efficiency of 12.6%, and peak power efficiency of 21.4 l m W−1 as measured in an integrating sphere. Both the efficiency and the color quality of the obtained device are ranking among one of the highest values for WPLEDs reported to date. Furthermore, as compared with those all-phosphorescent WPLEDs, the hybrid WPLEDs studied here exhibit a significantly reduced efficiency roll-off due to the very low doping concentration.
Classical group field theory
Authors: Ben Geloun Joseph
Published: February 2012

The ordinary formalism for classical field theory is applied to dynamical group field theories. Focusing first on a local group field theory over one copy of SU(2) and then, on more involved nonlocal theories (colored and noncolored) defined over a tensor product of the same group, we address the issue of translation and dilatation symmetries and the corresponding Noether theorem. The energy momentum tensor and dilatation current are derived and their properties identified for each case.
Single photon emission from InGaN/GaN quantum dots up to 50 K
Authors: Kremling Stefan , Tessarek Christian , Dartsch Heiko , Figge Stephan , Höfling Sven , Worschech Lukas , Kruse Carsten , Hommel Detlef , Forchel Alfred
Published: February 2012

We have investigated the optical properties of single InGaN quantum dots (QDs) by means of microphotoluminescence (μPL) spectroscopy. The QDs were grown on sapphire substrate using metal organic vapor phase epitaxy. Sharp and isolated single exciton emission lines in the blue spectral range were observed. The QD luminescence shows a strong degree of linear polarization up to 96% perpendicular to the growth axis (c-axis) with no preferential alignment in the xy plane. Second order autocorrelation measurements were performed under pulsed excitation and single photon emission up to 50 K is demonstrated.
Ionic-liquid-induced ferroelectric polarization in poly(vinylidene fluoride) thin films
Authors: Wang Feipeng , Lack Alexander , Xie Zailai , Frübing Peter , Taubert Andreas , Gerhard Reimund
Published: February 2012

Thin films of ferroelectric β-phase poly(vinylidene fluoride) (PVDF) were spin-coated from a solution that contained small amounts of the ionic liquid (IL) 1-ethyl-3-methylimidazolium nitrate. A remanent polarization of 60 mC/m2 and a quasi-static pyroelectric coefficient of 19 μC/m2K at 30 °C were observed in the films. It is suggested that the IL promotes the formation of the β phase through dipolar interactions between PVDF chain-molecules and the IL. The dipolar interactions are identified as Coulomb attraction between hydrogen atoms in PVDF chains and anions in IL. The strong crystallinity increase is probably caused by the same dipolar interaction as well.
Graphene induced tunability of the surface plasmon resonance
Authors: Niu Jing , Jun Shin Young , Lee Youngbin , Ahn Jong-Hyun , Yang Hyunsoo
Published: February 2012

Tunability of the surface plasmon resonance wavelength is demonstrated by varying the thickness of Al2O3 spacer layer inserted between the graphene and nanoparticles. By varying the spacer layer thickness from 0.3 to 1.8 nm, the resonance wavelength is shifted from 583 to 566 nm. The shift is due to a change in the electromagnetic field coupling strength between the localized surface plasmons excited in the gold nanoparticles and a single layer graphene film. In contrast, when the graphene film is absent from the system, no noticeable shift in the resonance wavelength is observed upon varying the spacer thickness.
Effect of surface plasmon energy matching on the sensing capability of metallic nano-hole arrays
Authors: Najiminaini Mohamadreza , Vasefi Fartash , Kaminska Bozena , Carson Jeffrey J. L.
Published: February 2012

We report on a nano-hole array structure with a single cavity beneath the perforated gold film. Structures were fabricated with a variety of cavity depths. The optical resonance of each structure as well as the surface plasmon (SP) energy matching between the top and bottom of the gold film were investigated. We also experimentally evaluated the sensitivity of the structures as surface plasmon resonance (SPR) sensors. We observed a 1.6-fold enhancement in bulk SPR sensitivity and a 3-fold improvement in figure of merit for a structure with a 350-nm cavity depth compared to a structure with a 5-nm cavity depth.
Nanostructure thermal conductivity prediction by Monte Carlo sampling of phonon free paths
Authors: McGaughey Alan J. H. , Jain Ankit
Published: February 2012

We propose a method by which the thermal conductivity of a nanostructure with arbitrary geometry can be predicted through Monte Carlo sampling of the free paths associated with phonon-phonon and phonon-boundary scattering. The required inputs are the nanostructure geometry and the bulk phonon frequencies, group velocities, and mean free paths. The method is applied to a thin film in the in-plane and cross-plane directions and to a polycrystalline bulk material. For the film, a faster approach to the bulk thermal conductivity is found compared to predictions made using the Matthiessen rule with the bulk mean free path and an average phonon-boundary scattering length.
Anomaly of film porosity dependence on deposition rate
Authors: Stagon Stephen P. , Huang Hanchen , Kevin Baldwin J. , Misra Amit
Published: February 2012

This letter reports an anomaly of film porosity dependence on deposition rate during physical vapor deposition – the porosity increases as deposition rate decreases. Using glancing angle deposition of Cu on SiO2 substrate, the authors show that the Cu film consists of well separated nanorods when the deposition rate is 1 nm/s, and that the Cu films consists of a more uniform film when the deposition rate is 6 nm/s; all other deposition conditions remain the same. This anomaly is the result of interplay among substrate non-wetting, density of Cu nuclei on the substrate, and the minimum diameter of nanorods.
Fabrication of nanoscale glass fibers by electrospinning
Authors: Praeger M. , Saleh E. , Vaughan A. , Stewart W. J. , Loh W. H.
Published: February 2012

We report the experimental realization of glass nanofibers by electrospinning directly from a melt, demonstrating the viability of electrospinning fibers from non-polymer materials with high melting temperatures and higher surface tensions. The nanofiber material (B2O3) is molten on the tip of a gold wire, and voltage applied to the tip causes a jet to form, resulting in solid glass fibers with diameters of ∼100 nm.
Forkhead box N4 (Foxn4) activates Dll4-Notch signaling to suppress photoreceptor cell fates of early retinal progenitors
Authors: Luo Huijun , Jin Kangxin , Xie Zhenhui , Qiu Feng , Li Shengguo , Zou Min , Cai Li , Hozumi Katsuto , Shima David T. , Xiang Mengqing
Published: February 2012

The generation of diverse neuronal types and subtypes from multipotent progenitors during development is crucial for assembling functional neural circuits in the adult central nervous system. During mouse retinogenesis, early retinal progenitors give rise to several cell types, including ganglion, amacrine, horizontal, cone, and rod cells. It is unknown at present how each of these fates is selected from the multiple neuronal fates available to the early progenitor. By using a combination of bioinformatic, genetic, and biochemical approaches, we investigated the mechanism by which Foxn4 selects the amacrine and horizontal cell fates from multipotential retinal progenitors. These studies indicate that Foxn4 has an intrinsic activity to suppress the alternative photoreceptor cell fates of early retinal progenitors by selectively activating Dll4-Notch signaling. Gene expression and conditional ablation analyses reveal that
Dll4
is directly activated by Foxn4 via phylogenetically conserved enhancers and that Dll4 can partly mediate the Foxn4 function by serving as a major Notch ligand to expand the progenitor pool and limit photoreceptor production. Our data together define a Foxn4-mediated molecular and signaling pathway that underlies the suppression of alternative cell fates of early retinal progenitors.
Synthesis and optical properties of polyurethane foam modified with silver nanoparticles
Authors: Apyari V V , Volkov P A , Dmitrienko S G
Published: February 2012

This paper for the first time describes peculiarities of synthesis of polyurethane foam modified with silver nanoparticles as a potential material for optical sensors in analytical chemistry. We found that the unique sorptional properties of polyurethane foam gave an opportunity to perform such a synthesis by two different approaches. The first one was based on sorption of previously synthesized in-solution nanoparticles by polyurethane foam, the second one consisted in preparation of nanoparticles directly in polyurethane foam matrix. This possibility is novel and interesting for practical use because the nanoparticles in polyurethane foam are capable of surface plasmon resonance. The influence of different factors during the synthesis was investigated and the optimal conditions were found. The samples prepared were characterized by diffuse reflectance spectroscopy and scanning electron microscopy. On the basis of the results obtained we first suggested that this material is attractive from the viewpoint of analytical chemistry as a convenient analytical form for determination of oxidants and reductants.
Reference points based on dynamic optimization: a versatile algorithm for mixed-fishery management with bioeconomic age-structured models
Authors: Da Rocha José-María , Gutiérrez María-José , Cerviño Santiago
Published: February 2012

Da Rocha, J-M., Gutiérrez, M-J., and Cerviño, S. 2012. Reference points based on dynamic optimization: a versatile algorithm for mixed-fishery management with bioeconomic age-structured models. – ICES Journal of Marine Science, 69: 660–669. Single-species management objectives may not be consistent within mixed fisheries. They may lead species to unsafe situations, promote discarding of over-quota, and/or misreporting of catches. We provide an algorithm for characterizing bioeconomic reference points for a mixed fishery as the steady-state solution of a dynamic optimal management problem. The optimization problem takes into account that: (i) species are caught simultaneously in unselective fishing operations, and (ii) intertemporal discounting and fleet costs relate to reference points to discounted economic profits along optimal trajectories. We illustrate how the algorithm can be implemented by applying it to the European northern hake stock (Merluccius merluccius), where fleets also capture northern megrim (Lepidorhombus whiffiagonis) and northern anglerfish (Lophius piscatorius and Lophius budegassa). We find that optimal mixed management leads to a target reference point that is quite similar to two-thirds of the Fmsy single-species (hake) target. Mixed management is superior to single-species management because it leads the fishery to higher discounted profits, with higher long-term spawning-stock biomass for all species. We calculate that the losses due to the use of the Fmsy single-species (hake) target in this mixed fishery account for 11.4% of total discounted profits.
Experiments and theory of undulatory locomotion in a simple structured medium
Authors: Majmudar Trushant , Keaveny Eric E. , Zhang Jun , Shelley Michael J.
Published: February 2012

Undulatory locomotion of micro-organisms through geometrically complex, fluidic environments is ubiquitous in nature and requires the organism to negotiate both hydrodynamic effects and geometrical constraints. To understand locomotion through such media, we experimentally investigate swimming of the nematodeCaenorhabditis elegansthrough fluid-filled arrays of micro-pillars and conduct numerical simulations based on a mechanical model of the worm that incorporates hydrodynamic and contact interactions with the lattice. We show that the nematode's path, speed and gait are significantly altered by the presence of the obstacles and depend strongly on lattice spacing. These changes and their dependence on lattice spacing are captured, both qualitatively and quantitatively, by our purely mechanical model. Using the model, we demonstrate that purely mechanical interactions between the swimmer and obstacles can produce complex trajectories, gait changes and velocity fluctuations, yielding some of the life-like dynamics exhibited by the real nematode. Our results show that mechanics, rather than biological sensing and behaviour, can explain some of the observed changes in the worm's locomotory dynamics.
PrPSc detection and infectivity in semen from scrapie-infected sheep
Authors: Rubenstein Richard , Bulgin Marie S. , Chang Binggong , Sorensen-Melson Sharon , Petersen Robert B. , LaFauci Giuseppe
Published: February 2012

A scrapie-positive ewe was found in a flock that had been scrapie-free for 13 years, but housed adjacent to scrapie-positive animals, separated by a wire fence. Live animal testing of the entire flock of 24 animals revealed seven more subclinical scrapie-positive ewes. We hypothesized that they may have contracted the disease from scrapie-positive rams used for breeding 4 months prior, possibly through the semen. The genotypes of the ewe flock were highly scrapie-susceptible and the rams were infected with the ‘Caine’ scrapie strain having a short incubation time of 4.3–14.6 months in sheep with 136/171 VQ/VQ and AQ/VQ genotypes. PrPSc accumulates in a variety of tissues in addition to the central nervous system. Although transmission of prion diseases, or transmissible spongiform encephalopathies, has been achieved via peripheral organ or tissue homogenates as well as by blood transfusion, neither infectivity nor PrPSc have been found in semen from scrapie-infected animals. Using serial protein misfolding cyclic amplification followed by a surround optical fibre immunoassay, we demonstrate that semen from rams infected with a short-incubation-time scrapie strain contains prion disease-associated-seeding activity that generated PrPSc in sPMCA (serial protein misfolding cyclic amplification). Injection of the ovinized transgenic mouse line TgSShpPrP with semen from scrapie-infected sheep resulted in PrPSc-seeding activity in clinical and, probably as a result of the low titre, non-clinical mouse brain. These results suggest that the transmissible agent, or at least the seeding activity, for sheep scrapie is present in semen. This may be a strain-specific phenomenon.
Replication and infectivity of a novel genotype 1b hepatitis C virus clone
Authors: Date Tomoko , Morikawa Kenichi , Tanaka Yasuhito , Tanaka‐Kaneko Keiko , Sata Tetsutaro , Mizokami Masashi , Wakita Takaji
Published: February 2012

Hepatitis C virus infection is a major public health problem because of an estimated 170 million carriers worldwide. Genotype 1b is the major subtype of HCV in many countries and is resistant to interferon therapy. Study of the viral life cycle is important for understanding the mechanisms of interferon resistance of genotype 1b HCV strains. For such studies, genotype 1b HCV strains that can replicate and produce infectious virus particles in cultured cells are required. In the present study, we isolated HCV cDNA, which we named the NC1 strain, from a patient with acute severe hepatitis. Subgenomic replicon experiments revealed that several mutations enhanced the colony‐formation efficiency of the NC1 replicon. The full‐length NC1 genome with these adaptive mutations could replicate in cultured cells and produce infectious virus particles. The density gradient profile and morphology of the secreted virus particles were similar to those reported for the JFH‐1 virus. Further introduction of a combination of mutations of the NS3 and NS5a regions into the NC1 mutants further enhanced secreted core protein levels and infectious virus titers in the culture medium of HCV‐RNA‐transfected cells. However, the virus infection efficiency was not sufficient for autonomous virus propagation in cultured cells. In conclusion, we established a novel cell culture‐adapted genotype 1b HCV strain, termed NC1, which can produce infectious virus when the viral RNA is transfected into cells. This system provides an important opportunity for studying the life cycle of the genotype 1b HCV.
Loss of 5‐hydroxymethylcytosine is accompanied with malignant cellular transformation
Authors: Kudo Yotaro , Tateishi Keisuke , Yamamoto Keisuke , Yamamoto Shinzo , Asaoka Yoshinari , Ijichi Hideaki , Nagae Genta , Yoshida Haruhiko , Aburatani Hiroyuki , Koike Kazuhiko
Published: February 2012

Dysregulated DNA methylation followed by abnormal gene expression is an epigenetic hallmark in cancer. DNA methylation is catalyzed by DNA methyltransferases, and the aberrant expression or mutations of DNA methyltransferase genes are found in human neoplasm. The enzymes for demethylating 5‐methylcytosine were recently identified, and the biological significance of DNA demethylation is a current focus of scientific attention in various research fields. Ten–eleven translocation (TET) proteins have an enzymatic activity for the conversion from 5‐methylcytosine to 5‐hydroxymethylcytosine (5‐hmC), which is an intermediate of DNA demethylation. The loss‐of‐function mutations of TET2 gene were reported in myeloid malignancies, suggesting that impaired TET‐mediated DNA demethylation could play a crucial role in tumorigenesis. It is still unknown, however, whether DNA demethylation is involved in biological properties in solid cancers. Here, we show the loss of 5‐hmC in a broad spectrum of solid tumors: for example, a significant reduction of 5‐hmC was found in 72.7% of colorectal cancers (CRCs) and 75% of gastric cancers compared to background tissues. TET1 expression was decreased in half of CRCs, and a large part of them was followed by the loss of 5‐hmC. These findings suggest that the amount of 5‐hmC in tumors is often reduced via various mechanisms, including the downregulation of TET1. Consistently, in the in vitro experiments, the downregulation of TET1 was clearly induced by oncogene‐dependent cellular transformation, and loss of 5‐hmC was seen in the transformed cells. These results suggest the critical roles of aberrant DNA demethylation for oncogenic processes in solid tissues. (Cancer Sci 2012; 103: 670–676)
MARVELD1 inhibited cell proliferation and enhance chemosensitivity via increasing expression of p53 and p16 in hepatocellular carcinoma
Authors: Yu Youtao , Zhang Yubao , Hu Jianran , Zhang Hao , Wang Shan , Han Fang , Yue Lei , Qu Youpeng , Zhang Yao , Liang Hongjian , Nie Huan , Li Yu
Published: February 2012

We have previously found that expression of MARVELD1 was remarkably downregulated in multiple tumor tissues, but unclear in hepatocellular carcinoma (HCC) and its function has not been explored yet. In the present study, to uncover the underlying mechanism of MARVELD1 in the pathogenesis and development of HCC, we investigated the expression pattern of MARVELD1 and its effect on tumor proliferation in HCC. The results indicated the frequent downregulation of MARVELD1 in clinic samples and cell lines of HCC resulted from promoter methylation, as well as genetic deletion. Furthermore, treatment of MARVELD1 unexpressing Hep3B2.1‐7 and PLC/PRF/5 cells with the demethylating agent 5‐aza‐2′ deoxycytidine restored its expression. Overexpression of MARVELD1 suppressed the proliferation of HCC cells in vitro and in vivo, whereas downregulation of endogenous MARVELD1 by shRNAs significantly enhanced these characters. MARVELD1 overexpression could enhance chemosensitivity of HCC cells to epirubicin and 10‐hydroxycamptothecin. Corresponding to these results, the expression of p‐ERK1/2 and cyclin D1 were decreased, whereas p16 and p53 were increased in MARVELD1‐transfected cells. We also demonstrated that knockdown of MARVELD1 resulted in upregulation of p‐ERK1/2 and cyclin D1, and downregulation of p16 and p53. Moreover, the effect of the decreased cell growth rate was significantly reversed when MARVELD1‐overexpressing cells were trasfected with p53 or p16 siRNA. Our findings suggest that MARVELD1 is a tumor suppressor by negatively regulating proliferation, tumor growth and chemosensitivity of HCC cells via increasing p53 and p16 in vitro and in vivo. MARVELD1 may be a potential target for HCC therapy. (Cancer Sci 2012; 103: 716–722)
Identification of a novel role of Septin 10 in paclitaxel‐resistance in cancers through a functional genomics screen
Authors: Xu Mingli , Takanashi Masakatsu , Oikawa Kosuke , Nishi Hirotaka , Isaka Keiichi , Yoshimoto Takayuki , Ohyashiki Junko , Kuroda Masahiko
Published: February 2012

Paclitaxel (also known as taxol) is a member of the taxane class of anticancer agents, which has a well‐known mechanism that blocks cell mitosis and kills tumor cells, that is often used in clinics to treat cancer. However, some carcinomas such as breast, ovarian and non‐small‐cell lung cancers are often resistant to paclitaxel treatment. In this study, we used a lentiviral siRNA library against the entire human genomes to identify genes associated with sensitivity to paclitaxel. We isolated two paclitaxel‐resistant clones carrying the siRNA specific to septin 10 (SEPT10) and to budding uninhibited by benzimidazoles 3. The relation of budding uninhibited by benzimidazoles 3 to paclitaxel sensitivity has already been established, but that of SEPT10 remains unknown. Interestingly, overexpression of SEPT10 increased cells’ sensitivity to paclitaxel; we also found that SEPT10 is an important regulator for microtubule stability. Furthermore, we found that paclitaxel‐resistant tumors had decreased expression of SEPT10. Thus, SEPT10 may be a novel candidate molecule that acts as a good indicator of paclitaxel‐resistant carcinomas (Cancer Sci 2012; 103: 821–827)
Polymorphisms of the vascular endothelial growth factor gene and severe radiation pneumonitis in non‐small cell lung cancer patients treated with definitive radiotherapy
Authors: Yin Ming , Liao Zhongxing , Yuan Xianglin , Guan Xiaoxiang , O'Reilly Michael S. , Welsh James , Wang Li‐E , Wei Qingyi
Published: February 2012

Vascular endothelial growth factor (VEGF) is a major mediator of angiogenesis and lung cancer progression. We hypothesized that VEGF polymorphisms may modulate the risk of radiation pneumonitis (RP) in non‐small cell lung cancer (NSCLC) patients treated with definitive radiotherapy. We genotyped three potentially functional VEGF single nucleotide polymorphisms (&460 T > C [rs833061], &634 G > C [rs2010963] and +936 C > T [rs3025039]) and estimated the associations of their genotypes and haplotypes with severe radiation pneumonitis (RP ≥grade 3) in 195 NSCLC patients. We found that the VEGF genotypes of rs2010963 and rs3025039 single nucleotide polymorphisms as well as the &460C/&634G/+936C haplotype were predictors of RP development (adjusted hazard ratio [adjHR] = 2.33, 95% confidence interval [CI], 1.01–5.37, P = 0.047 for CC vs GG genotypes; adjHR = 28.13, 95% CI, 5.24–151.02, P < 0.001 for TT vs CC genotypes; and adjHR = 2.51, 95% CI, 1.27–4.98, P = 0.008 for T‐C‐T vs C‐G‐C haplotypes). In addition, there was a trend towards reduced RP risk in patients carrying an increased number of protective VEGF genotypes. Our data suggest that VEGF polymorphisms can modulate the risk of radiation pneumonitis in NSCLC patients treated with definitive radiotherapy. Large and independent studies are needed to confirm our findings. (Cancer Sci 2012; 103: 945–950)
Interferon‐alpha modulates the chemosensitivity of CD133‐expressing pancreatic cancer cells to gemcitabine
Authors: Hayashi Tomomi , Ding Qiang , Kuwahata Taisaku , Maeda Koki , Miyazaki Yumi , Matsubara Shuichiro , Obara Toru , Natsugoe Shoji , Takao Sonshin
Published: February 2012

Pancreatic cancer is a lethal disease as current chemotherapies with gemcitabine (GEM) are still insufficient. Accumulating evidence suggests that cancer stem cells (CSC) are responsible for chemoresistance and that CD133 is one of the CSC markers in pancreatic cancer. Interferon‐alpha (IFN‐α), a cytokine with pleiotropic effects, has direct cytotoxic and cytostatic effects on tumor cells. The aim of the present study was to investigate whether IFN‐α can modulate the chemosensitivity of a human pancreatic cancer cell line, Capan‐1, to GEM. Cell cycles were evaluated for response to GEM with and without IFN‐α by BrdU assay. GEM inhibited Capan‐1 cell growth in a dose‐dependent manner. GEM (IC50; 100 ng/mL) treatment reduced the number of both CD133+ and CD133− cells in the S phase, induced apoptosis of CD133− cells more than that of CD133+ cells and increased accumulation of CD133+ cells into the G0/G1 phase. These results infer that CD133+ cells take shelter into the G0/G1 phase from GEM treatment. IFN‐α modulated CD133+ cells from the G0/G1 phase to the S phase. Consequently, apoptosis was accelerated in both CD133+ and CD133− cells after IFN‐α combined with GEM treatment. Furthermore, GEM combined with IFN‐α treatment showed a significant tumor suppressive effect in the in vivo study. Importantly, CD133+ cells showed CSC‐like properties, such as generation of spheres, highly invasive ability and high tumorigenesis. These results suggest that IFN‐α, as a modulator, could contribute to the treatment of CD133+ cancer cells and be effective in combined chemotherapies with GEM for pancreatic cancer stem‐like cells. (Cancer Sci 2012; 103: 889–896)
A novel pyrrolo[3, 2‐d]pyrimidine derivative, as a vascular endothelial growth factor receptor and platelet‐derived growth factor receptor tyrosine kinase inhibitor, shows potent antitumor activity by suppression of tumor angiogenesis
Authors: Awazu Yoshiko , Mizutani Akio , Nagase Yoshinori , Iwata Hidehisa , Oguro Yuya , Miki Hiroshi , Imamura Shinichi , Hori Akira
Published: February 2012

We recently reported that compound 20d (comp.20d), a novel pyrrolo[3, 2‐d]pyrimidine derivative, is a potent and selective inhibitor of tumor angiogenesis‐related kinases, including vascular endothelial growth factor receptor (VEGFR) and platelet‐derived growth factor receptor (PDGFR). In this study, we show that comp.20d potently blocks the VEGF‐ and PDGF‐stimulated cellular phosphorylation (IC50 = 2.5 and 3.6 nM, respectively) and proliferation of HUVECs and human coronary artery smooth muscle cells with IC50 values of 2.8 and 9.6 nM, respectively, and potently inhibits the VEGF‐induced tube formation of endothelial cells cocultured with fibroblasts (IC50 = 3.3 nM). Given orally twice daily, comp.20d at the doses of 1.5–6 mg/kg showed antitumor effects in mice bearing various human cancer xenografts. Consistent with the anti‐angiogenic mechanism of action, histological examination of tumors from comp. 20d‐treated mice indicated a decrease in microvessel density and inhibition of pericyte recruitment to microvessels, and these were concomitant with decreased interstitial fluid pressure that allowed for therapeutic intratumoral uptake of CPT‐11 (irinotecan hydrochloride). In conclusion, comp.20d is an extremely potent inhibitor of VEGFR/PDGFR kinases whose activities suggest therapeutic potential for the treatment of solid tumors that rely on angiogenesis for their survival. (Cancer Sci 2012; 103: 939–944)
Comparative dynamics of four smoking withdrawal symptom scales
Authors: Javitz Harold S. , Lerman Caryn , Swan Gary E.
Published: February 2012

Aims  To examine the association of person‐specific trajectories of withdrawal symptoms of urge‐to‐smoke, negative affect, physical symptoms and hunger during the first 7 days after smoking cessation with abstinence at end of treatment (EOT) and at 6 months.

Design  Hierarchical linear modeling (HLM) was used to model person‐specific trajectory parameters (level, slope, curvature and volatility) for withdrawal symptoms.

Setting  University‐based smoking cessation trials.

Participants  Treatment‐seeking smokers in clinical trials of transdermal nicotine versus nicotine spray (n = 514) and bupropion versus placebo (n = 421).

Measurements  Self‐reported withdrawal symptoms for 7 days after the planned quit date, and 7‐day point prevalence and continuous abstinence at EOT and 6 months.

Findings  In regressions that included trajectory parameters for one group of withdrawal symptoms, both urge‐to‐smoke and negative affect were predictive of abstinence while physical symptoms and hunger were generally not predictive. In stepwise regressions that included the complete set of trajectory parameters across withdrawal symptoms (for urge‐to‐smoke, negative affect, physical symptoms and hunger), with a single exception only the trajectory parameters for urge‐to‐smoke were predictive. Area under the receiver operator characteristic curve was 0.594 for covariates alone, and 0.670 for covariates plus urge‐to‐smoke trajectory parameters.

Conclusions  Among a number of different withdrawal symptoms (urge‐to‐smoke, negative affect, physical symptoms and hunger) urge‐to‐smoke trajectory parameters (level, slope and volatility) over the first 7 days of smoking cessation show the strongest prediction of both short‐ and long‐term relapse. Other withdrawal symptoms increase the predictive ability by negligible amounts.
Awake videolaryngoscopy‐assisted tracheal intubation of the morbidly obese
Authors: Moore A. R. , Schricker T. , Court O.
Published: February 2012

Awake videolaryngoscopy may be useful for the tracheal intubation of the morbidly obese. This prospective, observational study enrolled 50 patients undergoing bariatric surgery. After sedation and topical anaesthesia of the airway, awake tracheal intubation was attempted, assisted by videolaryngoscopy, and terminated if there was severe gagging, coughing, or inadequate laryngeal view. After three attempts the procedure was considered a failure. Twenty‐seven intubations were successful on the first attempt, fifteen on the second, six on the third and two were not successful, giving a success rate of 96% (95% CI 86–100%). In one failure, inserting the tracheal tube caused severe gagging in spite of an adequate view of the larynx, and the trachea was intubated with the videolaryngoscope after induction of anaesthesia. The second failure was due to gagging, with subsequent tracheal intubation successful using fibreoptic bronchoscopy. When managing the morbidly obese airway, awake tracheal intubation using videolaryngoscopy may be considered.
The precision of PiCCO®measurements in hypothermic post‐cardiac arrest patients
Authors: Tagami T. , Kushimoto S. , Tosa R. , Omura M. , Hagiwara J. , Hirama H. , Yokota H.
Published: February 2012

The aim of the present study was to determine the precision of the PiCCO®system for post‐cardiac arrest patients who underwent therapeutic hypothermia. The precision of the measurements for cardiac output, global end‐diastolic volume, extravascular lung water and the pulmonary vascular permeability index was assessed using the least significant change; this was regarded as precise when less than 15%. A total of 462 measurement sets were prospectively performed on 88 patients following successful resuscitation after cardiac arrest. Using the mean value of three injections for a measurement, the least significant change for the cardiac output, global end‐diastolic volume, extravascular lung water and pulmonary vascular permeability index measurements were found to be 7.8%, 8.5%, 7.8% and 12.1%, respectively. No significant differences between hypothermia (n = 150) and non‐hypothermia (n = 312) were found. The PiCCO‐derived variables were found to be precise for post‐cardiac arrest patients even under conditions of varying body temperature.
The effect of nitrous oxide on intra‐ocular pressure in healthy adults*
Authors: Lalwani K. , Fox E. B. , Fu R. , Edmunds B. , Kelly L. D.
Published: February 2012

Many anaesthetic agents affect intra‐ocular pressure, yet little is known about nitrous oxide and intra‐ocular pressure. This study assessed the effect of nitrous oxide on intra‐ocular pressure in 20 healthy adult volunteers. The intra‐ocular pressure was measured at baseline, while breathing a 70:30 mix of nitrous oxide and oxygen for 12 min, and then while breathing room air for 15 min. A linear mixed effects model was used to assess change in intra‐ocular pressure over time. There was no significant difference in intra‐ocular pressure between baseline and during or after nitrous oxide inhalation. Several differences in intra‐ocular pressure were noted between internal time‐points: pressure increased by 2.4 mmHg between 3 and 6 min of breathing nitrous oxide (p = 0.01); it increased by 1.4 mmHg between 3 and 9 min of breathing nitrous oxide (p = 0.046); and it decreased by 2.2 mmHg between 6 min of breathing nitrous oxide and 15 min of breathing room air (p = 0.035). This study indicates that nitrous oxide inhalation does not significantly change intra‐ocular pressure from baseline values in a population of healthy adults.
The role of sugammadex in the development and modification of an allergic response to rocuronium: evidence from a cutaneous model*
Authors: Clarke R. C. , Sadleir P. H. M. , Platt P. R.
Published: February 2012

The availability of sugammadex as a selective encapsulating agent for rocuronium has led to speculation that it may be useful in mitigating rocuronium‐induced anaphylaxis. Off‐label use of sugammadex for this indication has already been documented in case reports although there are theoretical objections to the likelihood of an allergen‐binding agent's being able to attenuate the immunological cascade of anaphylaxis. Using a cutaneous model of anaphylaxis in rocuronium‐sensitised patients, we were unable to demonstrate that sugammadex was effective in attenuating the type‐1 hypersensitivity reaction after it has been triggered by rocuronium, but we were able to demonstrate that these patients are anergic to sugammadex‐bound rocuronium. These findings demonstrate that a cyclodextrin can bind an allergen and exclude it from interacting with the immune system, and may potentially lead to novel applications in other allergic diseases. However, there is no evidence that sugammadex should be used for the treatment of rocuronium‐induced anaphylaxis, and clinical management should follow established protocols.
RCL2, a potential formalin substitute for tissue fixation in routine pathological specimens
Authors: Masir Noraidah , Ghoddoosi Mahdiieh , Mansor Suhada , Abdul‐Rahman Faridah , Florence Chandramaya S. , Mohamed‐Ismail Nor Azlin , Tamby Mohammad‐Rafaee , Md‐Latar Nani Harlina
Published: February 2012

Masir N, Ghoddoosi M, Mansor S, Abdul‐Rahman F, Florence C S, Mohamed‐Ismail N A, Tamby M‐R & Md‐Latar N H  (2012) Histopathology 60, 804–815

RCL2, a potential formalin substitute for tissue fixation in routine pathological specimens

Aims:  To investigate RCL2 as a fixative for tissue fixation in routine histopathological examination and to assess tissue suitability for ancillary investigations.

Methods and results:  Forty‐nine samples from 36 fresh specimens were cut into three equal pieces and fixed in RCL2 diluted in 100% ethanol, RCL2 in 95% ethanol, or neutral buffered formalin as control. Suitability for microtomy, quality of histomorphology, histochemistry, immunohistochemistry, fluorescent and silver in‐situ hybridization analysis and extracted genomic DNA were assessed. Microtomy was straightforward in most tissue blocks, but there was difficulty in cutting in approximately a quarter of samples, which required careful handling by an experienced technician. There were no significant differences in tissue morphology between RCL2‐ and formalin‐fixed tissues (P = 0.08). Generally, the quality of histochemical staining, immunohistochemistry and in‐situ hybridization were comparable to that of formalin‐fixed tissues. Inconsistent immunoreactivity was noted, however, with antibodies against pan‐cytokeratin and progesterone receptor. Genomic DNA concentration was higher in RCL2‐fixed tissues. Using RCL2 diluted in 95% ethanol did not affect fixation quality.

Conclusion:  RCL2 is a potential formalin substitute suitable as a fixative for use in routine histopathological examination; however, difficulty in microtomy and occasional discrepancies in immunohistochemical reactivity require further optimization of the methodology.
Prognostic significance of phosphorylated STAT‐1 expression in premenopausal and postmenopausal patients with invasive breast cancer
Authors: Magkou Christina , Giannopoulou Ioanna , Theohari Irene , Fytou Alexandra , Rafailidis Petros , Nomikos Alexandros , Papadimitriou Christos , Nakopoulou Lydia
Published: February 2012

Magkou C, Giannopoulou I, Theohari I, Fytou A, Rafailidis P, Nomikos A, Papadimitriou C & Nakopoulou L  (2012) Histopathology 60, 1125–1132

Prognostic significance of phosphorylated STAT‐1 expression in premenopausal and postmenopausal patients with invasive breast cancer

Aims:  STAT‐1 is the first member of the family of signal transducers and activators of transcription (STATs). In breast cancer experimental models, an apoptotic and antiproliferative effect has been demonstrated. Our aim was to study the role of phosphorylated STAT‐1 (pSTAT‐1) in invasive breast carcinoma and its prognostic significance in premenopausal and postmenopausal patients.

Methods and results:  Immunohistochemistry was performed in 165 patients in order to detect the expression of pSTAT‐1 and its correlation with oestrogen receptor (ER), progesterone receptor (PR), caspase‐3, and pAkt. pSTAT‐1 was immunodetected in the cytoplasm of the malignant cells (11.6%). In premenopausal patients, cytoplasmic pSTAT‐1 was positively correlated with stage (P = 0.014), ER (P = 0.008), caspase‐3 (P = 0.029), and pAkt (P = 0.045). Univariate analysis showed that cytoplasmic pSTAT‐1 was associated with poor overall survival (P = 0.042) and the phenotype of pSTAT‐1/ER or PR coexpression with shorter disease‐free survival (P = 0.012). In contrast, in postmenopausal patients, no association with clinicopathological parameters and survival was observed, except for the relationship of pSTAT‐1/ER or PR coexpression with longer disease‐free survival (P = 0.034).

Conclusions:  This is the first study examining the role of pSTAT‐1 in premenopausal and postmenopausal women with invasive breast cancer. Our results suggest that pSTAT‐1 is related to tumour progression in premenopausal patients through the advanced stage and worse survival.