bluuebunny/crossref_metadata_2025_split huggingface dataset:
TSC1 involvement in bladder cancer: diverse effects and therapeutic implications
Authors: Guo Yanan , Chekaluk Yvonne , Zhang Jianming , Du Jinyan , Gray Nathanael S , Wu Chin‐Lee , Kwiatkowski David J 
Published: February 2013

AbstractTSC1 is often mutated in bladder cancer. However the importance of this event in disease pathogenesis and its implications for therapy are uncertain. We used genomic sequencing to examine the involvement of TSC1 in bladder cancer, and signalling pathway analysis and small‐molecule screening to identify targeted therapeutic strategies in TSC1 mutant bladder cancer cell lines. TSC1 loss of heterozygosity was seen in 54% of bladder cancers. Two (4.9%) of these 41 bladder cancers had TSC1 mutations by exon‐based sequencing. Analysis of 27 bladder cancer cell lines demonstrated inactivating TSC1 mutations in three: RT‐4, HCV29, 97–1. Interestingly, only RT‐4 showed classic feedback inhibition of AKT, and was highly sensitive to treatment with mTOR inhibitors rapamycin and Torin1. 97–1 cells showed constitutive EGFR activation, and were highly sensitive to combined treatment with the mTOR inhibitor Torin1 and EGFR inhibitors Lapatinib or Afatinib. A BRAF missense mutation G469V was found in HCV29 cells, and AKT activation was dependent on BRAF, but independent of ERK. A kinase inhibitor screen of HCV29 cells showed strong growth inhibition by the Hsp90 inhibitor NVP‐AUY922, and we then found synergistic inhibitory effects of NVP‐AUY922 combined with either Torin1 or rapamycin on cell survival for both HCV29 and 97–1 cells. In aggregate, these findings indicate that there are highly variable mutation profiles and signalling pathway activation in TSC1‐mutant bladder cancer. Furthermore, combined Hsp90/mTOR inhibition is a promising therapeutic approach for TSC1 mutant bladder cancer. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Essential role of stem cell factor–c‐Kit signalling pathway in bleomycin‐induced pulmonary fibrosis
Authors: Ding Lin , Dolgachev Vladilsav , Wu Zhuang , Liu Tianju , Nakashima Taku , Wu Zhe , Ullenbruch Matthew , Lukacs Nicholas W , Chen Zidi , Phan Sem H 
Published: February 2013

AbstractStem cell factor (SCF) and its receptor c‐Kit have been implicated in tissue remodelling and fibrosis. Alveolar fibroblasts from patients with diffuse interstitial fibrosis secrete more SCF. However, its precise role remains unclear. In this study the potential role of the SCF–c‐Kit axis in pulmonary fibrosis was examined. Fibrosis was induced by intratracheal instillation of bleomycin (BLM), which caused increased SCF levels in plasma, bronchoalveolar lavage fluid (BALF) and lung tissue, as well as increased expression by lung fibroblasts. These changes were accompanied by increased numbers of bone marrow‐derived c‐Kit+ cells in the lung, with corresponding depletion in bone marrow. Both recombinant SCF and lung extracts from BLM‐treated animals induced bone‐marrow cell migration, which was blocked by c‐Kit inhibitor. The migrated cells promoted myofibroblast differentiation when co‐cultured with fibroblasts, suggesting a paracrine pathogenic role. Interestingly, lung fibroblast cultures contained a subpopulation of cells that expressed functionally active c‐Kit, which were significantly greater and more responsive to SCF induction when isolated from fibrotic lungs, including those from patients with idiopathic pulmonary fibrosis (IPF). This c‐Kit+ subpopulation was αSMA‐negative and expressed lower levels of collagen I but significantly higher levels of TGFβ than c‐Kit‐negative cells. SCF deficiency achieved by intratracheal treatment with neutralizing anti‐SCF antibody or by use of KitlSl/KitlSl‐d mutant mice in vivo resulted in significant reduction in pulmonary fibrosis. Taken together, the SCF–c‐Kit pathway was activated in BLM‐injured lung and might play a direct role in pulmonary fibrosis by the recruitment of bone marrow progenitor cells capable of promoting lung myofibroblast differentiation. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Behavior of high density polyethylene and its nanocomposites under static and dynamic compression loadings
Authors: Hu Y. , Liu T. , Ding J.L. , Zhong W.H. 
Published: February 2013

AbstractIn this study, the deformation behavior of high density polyethylene (HDPE) and its nanocomposites under uniaxial static and dynamic compression loadings were experimentally investigated. The nanofillers used were carbon nanofibers (CNF) with surface treatments and pristine graphite nanoplatelets (GNP) respectively. The dynamic tests were performed at the strain rates of 1 × 103, 4 × 103, and 7 × 103/s using the split Hopkinson pressure bar and the static tests were done at the strain rate of 1 × 10−2/s. In addition, microstructual examinations were performed to gain insights into the observed macroscopic behavior. It was observed that all the materials showed appreciable strain‐rate sensitivity. CNF‐based nanocomposites exhibited higher strength compared to that of the HDPE matrix material. However, the strength enhancement by GNP was very limited. The lower strength in HDPE/GNP relative to that of HDPE/CNF is likely due to the defect formation around the poor interface between polyethylene matrix and GNP reinforcement. Furthermore, the GNP with lamellate structure is also likely to create two‐dimensional interfacial cracks between the two phases, and hence weaken the strength and stability of the composites. It was also observed that for HDPE/CNF composites, different surface treatments did not seem to show significant effects on material strength. POLYM. COMPOS., 2013 © 2013 Society of Plastics Engineers
Characterization of in situ prepared nanocomposites of PS and TIO2 nanoparticles surface modified with alkyl gallates: Effect of alkyl chain length
Authors: Džunuzović Enis S. , Džunuzović Jasna V. , Radoman Tijana S. , Marinović‐Cincović Milena T. , Nikolić Ljubiša B. , Jeremić Katarina B. , Nedeljković Jovan M. 
Published: February 2013

AbstractIncorporation of surface modified TiO2 nanoparticles into polystyrene (PS) matrix was achieved by in situ bulk radical polymerization of styrene. The surface of TiO2 nanoparticles was modified with four amphiphilic esters of the gallic acid (octyl, decyl, lauryl and cetyl gallate), which have different lengths of hydrophobic alkyl chain (C8–C16). FTIR and UV‐Vis spectroscopy measurements confirmed the formation of a charge transfer complex between surface Ti atoms and gallic esters. Microstructural characterization of the synthesized nanocomposites revealed that the best dispersion of TiO2 nanoparticles in PS was achieved when the TiO2 surface was modified with octyl gallate. The presence of surface modified TiO2 nanoparticles by different alkyl gallates does not have an influence on the molecular weight and glass transition temperature of PS matrix. On the other hand, thermal and thermo‐oxidative stability of PS were significantly improved by incorporation of surface modified TiO2 nanoparticles. The most pronounced improvement of thermal and thermo‐oxidative stability was observed for TiO2 nanoparticles surface modified with octyl gallate. POLYM. COMPOS., 2013. © 2013 Society of Plastics Engineers
1:2‐sequence‐regulated radical copolymerization of naturally occurring terpenes with maleimide derivatives in fluorinated alcohol
Authors: Matsuda Masaru , Satoh Kotaro , Kamigaito Masami 
Published: February 2013

AbstractNaturally occurring bulky terpenes, such as (+)‐ and (–)‐limonene and (–)‐β‐pinene, were quantitatively copolymerized with maleimide (MI) derivatives (i.e., phenyl‐, cyclohexyl‐, ethyl‐, and unsubstituted‐MI) in PhC(CF3)2OH solvent via selective 1:2‐alternating propagation governed by the penultimate effect, which resulted in 1:2‐sequence regulated polymers with relatively high glass transition temperatures and optical activities. Similar petroleum‐derived bulky olefins possessing cyclohexenyl, cyclohexyl, or additional α‐methyl substituents were copolymerized with phenylmaleimide via preferential 1:2‐alternating propagation with a slightly lower selectivity. A further decrease in the bulkiness of nonpolar olefins increased the 1:1‐alternating sequence. The copolymerization of limonene and acrylonitrile also proceeded approximately via 1:1‐alternating propagation, in which the penultimate effect was less observable. Furthermore, when methylene chloride was used instead of fluorinated alcohol for the copolymerization of limonene and phenylmaleimide, the length of the sequence of MI units increased. Thus, in addition to the characteristic MI skeleton, the bulky and rather specific structure of either limonene or β‐pinene induces 1:2‐selective propagation via the penultimate effect, whereas the fluoroalcohol diminishes the homopropagation of MI via a hydrogen bonding interaction with the MI unit. RAFT copolymerization of limonene and various MI derivatives in PhC(CF3)2OH successfully proceeded to give the end‐to‐end 1:2‐sequence‐regulated copolymer with a selective initiating sequence and predominant capping sequence using an appropriate RAFT agent. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
In situ nitroxide‐mediated polymerization of styrene promoted by the N‐tert‐butyl‐α‐isopropylnitrone/bpo pair: ESR investigations
Authors: Detrembleur Christophe , Clément Jean‐Louis , Sciannaméa Valérie , Jérôme Christine , Catala Jean‐Marie , Gigmes Didier , Autissier Laurent , Botek Edith , Zarycz Natalia , Champagne Benoît 
Published: February 2013

AbstractThe styrene polymerization initiated by benzoyl peroxide (BPO) in the presence of N‐tert‐butyl‐α‐isopropylnitrone as nitroxide precursor is well‐controlled provided that a prereaction between the nitrone and BPO is carried out in suitable conditions prior to polymerization at a higher temperature. Electron spin resonance (ESR) spectroscopy was implemented to probe the nitroxides formed during both steps, that is, the prereaction and polymerization, and to get crucial information regarding the structure of the nitroxides responsible for the polymerization control. ESR studies combined with first principles calculations have evidenced that nitroxides observed during the prereaction in the presence of styrene and during the polymerization steps consist of a mixture of two macronitroxides. One is formed by the addition of a growing polystyrene chain to the nitrone as would be expected. However, the second one results from the addition of a polystyrene chain to tert‐butyl nitroso that is in situ formed presumably by decomposition of the first macronitroxide type. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
In situ polymerization and characterization of graphene oxide‐co‐poly(phenylene benzobisoxazole) copolymer fibers derived from composite inner salts
Authors: Li Yanwei , Li Jun , Song Yuanjun , Hu Zhen , Zhao Feng , Huang Yudong 
Published: February 2013

AbstractA facile and efficient strategy for preparing well dispersed graphene oxide (GO)‐co‐Poly(phenylene benzobisoxazole) (PBO) copolymer fibers was carried out by direct in situ polycondensation of composite inner salts. The composite inner salts were achieved to improve the dispersivity, solubility, reactivity, and interfacial adhesion of GO in PBO polymer matrix. The structure and morphology of GO‐co‐PBO copolymer fibers have been characterized. It was demonstrated that GO were covalently incorporated with PBO molecular chains and dispersed considerably well in PBO fiber even the GO reach to 3 wt %. Meanwhile, the tensile modulus, tensile strength and thermal stability of GO‐co‐PBO copolymer fibers increased considerably with GO. The mechanism and theoretical calculation of GO enhanced PBO fiber were also discussed. The main reasons for the improvement on performance of PBO fiber should be attributed to good dispersion GO in PBO matrix and covalent bonding networks at the interface between GO and PBO molecular chains. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Synthesis of a well‐defined polyallene‐based amphiphilic graft copolymer via sequential living coordination polymerization and SET‐LRP
Authors: Lu Guolin , Li Yongjun , Dai Bin , Xu Caixia , Huang Xiaoyu 
Published: February 2013

AbstractA well‐defined amphiphilic graft copolymer, poly(6‐methyl‐1,2‐heptadien‐4‐ol)‐g‐poly(2‐(dimethylamino)ethyl methacrylate) (PMHDO‐g‐PDMAEMA), has been synthesized by the combination of living coordination polymerization, single electron transfer‐living radical polymerization (SET‐LRP), and the grafting‐from strategy. PMHDO backbone containing double bonds and pendant hydroxyls was first prepared by [(η3‐allyl)NiOCOCF3]2‐initiated living coordination polymerization of 6‐methyl‐1,2‐heptadien‐4‐ol (MHDO) followed by treating the pendant hydroxyls with 2‐chloropropionyl chloride to give PMHDO‐Cl macroinitiator. SET‐LRP of 2‐(dimethylamino)ethyl methacrylate (DMAEMA) was performed in THF/H2O using PMHDO‐Cl as macroinitiator and CuCl/Me6TREN as catalytic system to afford the well‐defined PMHDO‐g‐PDMAEMA graft copolymer with a narrow molecular weight distribution (Mw/Mn = 1.28). The grafting density was as high as 92%. The critical micelle concentration (cmc) in water was determined by fluorescence probe technique and the micellar morphology was preliminarily explored by transmission electron microscopy. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Tuning the frontier molecular orbital energy levels of n‐type conjugated copolymers by using angular‐shaped naphthalene tetracarboxylic diimides, and their use in all‐polymer solar cells with high open‐circuit voltages
Authors: Chen Shan‐Ci , Zheng Qingdong , Zhang Qikai , Cai Dongdong , Wang Jinyun , Yin Zhigang , Tang Changquan 
Published: February 2013

AbstractAn angular‐shaped naphthalene tetracarboxylic diimide (NDI) was designed and synthesized as a new building block for n‐type conjugated polymers to tune their energy levels. Three n‐type copolymers incorporating this angular‐shaped NDI as the acceptor moiety were obtained by Stille coupling reactions and had number average molecular weights of 18.7–73.0 kDa. All‐polymer bulk‐heterojunction solar cells made from blends of these polymers with poly(3‐hexylthiophene) gave a power conversion efficiency up to 0.32% and exhibited an open‐circuit voltage (Voc) up to 0.94 V due to their relative high‐lying lowest unoccupied molecular orbital energy levels. The high Voc of 0.94 V is higher than that of solar cells based on linear‐shaped NDI‐containing polymers (<0.6 V). The results indicate that the angular‐shaped NDI is a promising building block for constructing nonfullerene polymer acceptors for solar cells with high open‐circuit voltages. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Assembly of anthrax toxin pore: Lethal‐factor complexes into lipid nanodiscs
Authors: Akkaladevi N. , Hinton‐Chollet L. , Katayama H. , Mitchell J. , Szerszen L. , Mukherjee S. , Gogol E. P. , Pentelute B. L. , Collier R. J. , Fisher M. T. 
Published: February 2013

AbstractWe have devised a procedure to incorporate the anthrax protective antigen (PA) pore complexed with the N‐terminal domain of anthrax lethal factor (LFN) into lipid nanodiscs and analyzed the resulting complexes by negative‐stain electron microscopy. Insertion into nanodiscs was performed without relying on primary and secondary detergent screens. The preparations were relatively pure, and the percentage of PA pore inserted into nanodiscs on EM grids was high (∼43%). Three‐dimensional analysis of negatively stained single particles revealed the LFN‐PA nanodisc complex mirroring the previous unliganded PA pore nanodisc structure, but with additional protein density consistent with multiple bound LFN molecules on the PA cap region. The assembly procedure will facilitate collection of higher resolution cryo‐EM LFN‐PA nanodisc structures and use of advanced automated particle selection methods.
Effect of the Ir and Zn monovacancy on the electron and positron properties in UIr2Zn20
Authors: Rubaszek Anna 
Published: February 2013

AbstractIn the literature, there is a striking controversy concerning the basic physical properties of UIr2Zn20 crystals that have been recently measured by various research groups. One may suppose that the particular samples are not free of defects and this is the likely reason for the discrepancy between the reported key experimental results. Here, positron annihilation spectroscopy serves as a very sensitive tool to probe lattice perfection with respect to the presence of open‐volume defects. In the present work, we perform calculations of the electron density of states (DOS), positron distribution, and positron lifetime, τ, in the UIr2Zn20 perfect crystal of Fd‐3m cubic structure (according to our best knowledge, for the first time in the literature). The results are compared with their counterparts for the crystals containing an Ir and Zn1 monovacancy. Three sharp narrow peaks from 5f U electrons are observed in the DOS close to the Fermi energy, EF, both for the perfect crystal as well as for the one containing vacancies. These peaks are located below, above and just at the Fermi level. Two peaks originate from f5/2 and f7/2 states, while the existence of the remaining one may be interpreted in terms of the dual character of uranium f electrons. The presence of vacancies considerably redistributes the positron charge in the unit cell and, in consequence, increases the value of the positron lifetime as compared with the perfect material.
Investigation of indium incorporation into InGaN by nitridation of sapphire substrate in MOVPE
Authors: Choi Jung‐Hun , Shojiki Kanako , Tanikawa Tomoyuki , Hanada Takashi , Katayama Ryuji , Matsuoka Takashi 
Published: February 2013

AbstractInGaN films on nitride‐sapphire substrates were grown by metalorganic vapor phase epitaxy. Reciprocal space mappings of X‐ray diffraction around the $(10\bar15)$ asymmetric plane were used to measure the accurate indium composition and in‐plane strain of InGaN films. InGaN films with nitridation of sapphire substrates shows higher indium incorporation than without nitridation samples at low molar fraction ratio, TMIn/(TMIn+TEGa), of group‐III MO source. However, the high molar fraction ratio region shows relatively low indium composition of InGaN. Most of the InGaN on nitrided sapphire substrates showed narrow FWHM of 2θ –ω and X‐ray rocking curves and the surface flatness is improved, which indicates the improvement of crystal quality. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Two modes of HVPE growth of GaN and related macrodefects
Authors: Voronenkov V. V. , Bochkareva N. I. , Gorbunov R. I. , Latyshev P. E. , Lelikov Y. S. , Rebane Y. T. , Tsyuk A. I. , Zubrilov A. S. , Popp U. W. , Strafela M. , Strunk H. P. , Shreter Y. G. 
Published: February 2013

AbstractGaN films with thickness up to 3 mm were grown by halide vapour phase epitaxy method. Two growth modes were observed: the high temperature (HT) mode and the low temperature (LT) mode. Films grown in HT mode had smooth surface, however the growth stress was high and caused cracking. Films grown in LT mode had rough surface with high density of V‐defects (pits), however, such films were crack‐free. The influence of growth parameters on the pit shape and evolution was investigated. Origins of pits formation and process of pit overgrowth are discussed. Crack‐free films with smooth surface and reduced density of pits were grown using combination of the LT and HT growth modes. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characterization of MBE‐grown AlGaN layers heavily doped using silane
Authors: Zhuravlev K. S. , Osinnykh I. V. , Protasov D. Yu. , Malin T. V. , Davydov V. Yu. , Smirnov A. N. , Kyutt R. N. , Spirina A. V. , Solomonov V. I. 
Published: February 2013

AbstractThe Alx Ga1–xN layers with a wide range of AlN molar fraction (0 < x < 0.6) were grown by ammonia MBE on (0001)‐oriented sapphire substrates using silane as the silicon dopant. The structural, electrical and optical properties of the layers were investigated by atomic force microscopy, X‐ray diffraction, Hall, Raman, photoluminescence and cathodoluminescence measurements. It was found that doping affects surface morphology, dislocation density and luminescence intensity of the Alx Ga1–xN layers. A sharp decrease of the luminescence intensity for the heavily doped GaN and Al0.3Ga0.7N layers was explained by enhancement of the nonradiative recombination rate in degenerate GaN layers and by an increase in the defect concentration in AlGaN layers. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The quantum‐confined Stark effect and localization of charge carriers in AlxGa1‐xN/AlyGa1‐yN quantum wells with different morphologies
Authors: Shevchenko E. A. , Jmerik V. N. , Mizerov A. M. , Nechaev D. V. , Sitnikova A. A. , Ivanov S. V. , Toropov A. A. 
Published: February 2013

AbstractWe present a comparative study of three samples with a single Al0.3Ga0.7N/Al0.4Ga0.6N quantum well (QW) grown by plasma‐assisted molecular beam epitaxy on c ‐sapphire substrates with an AlN buffer deposited under different Al/N flux ratios. We show by means of transmission electron microscopy that strong N‐rich growth conditions result in a three‐dimensional morphology that is inherited by the QW. As a result, the QW is corrugated on the size scale of the QW photoluminescence (PL) wavelength (∼300 nm).The Al‐rich conditions lead to a two‐dimensional growth and formation of a plane QW with flat interfaces. The PL line in the corrugated QW is 5 times more intensive and shifted toward larger energies by ∼200 meV, as compared with the plane QW. The superior emission properties are explained by simultaneous action of several factors such as suppression of the quantum‐confined Stark effect, enhanced carrier localization, and improved efficiency of light extraction. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)