bluuebunny/crossref_metadata_2025_split huggingface dataset:
The nicotinamide adenine dinucleotide phosphate oxidase (NOX) homologues NOX1 and NOX2/gp91phox mediate hepatic fibrosis in mice
Authors: Paik Yong-Han , Iwaisako Keiko , Seki Ekihiro , Inokuchi Sayaka , Schnabl Bernd , Österreicher Christoph H. , Kisseleva Tatiana , Brenner David A. 
Published: March 2011

Abstract

Nicotinamide adenine dinucleotide phosphate oxidase (NOX) is a multicomponent enzyme that mediates electron transfer from nicotinamide adenine dinucleotide phosphate to molecular oxygen, which leads to the production of superoxide. NOX2/gp91phox is a catalytic subunit of NOX expressed in phagocytic cells. Several homologues of NOX2, including NOX1, have been identified in nonphagocytic cells. We investigated the contributory role of NOX1 and NOX2 in hepatic fibrosis. Hepatic fibrosis was induced in wild-type (WT) mice, NOX1 knockout (NOX1KO) mice, and NOX2 knockout (NOX2KO) mice by way of either carbon tetrachloride (CCl4) injection or bile duct ligation (BDL). The functional contribution of NOX1 and NOX2 in endogenous liver cells, including hepatic stellate cells (HSCs), and bone marrow (BM)-derived cells, including Kupffer cells (KCs), to hepatic reactive oxygen species (ROS) generation and hepatic fibrosis was assessed

in vitro

and

in vivo

using NOX1 or NOX2 BM chimeric mice. Hepatic NOX1 and NOX2 messenger RNA expression was increased in the two experimental mouse models of hepatic fibrosis. Whereas NOX1 was expressed in HSCs but not in KCs, NOX2 was expressed in both HSCs and KCs. Hepatic fibrosis and ROS generation were attenuated in both NOX1KO and NOX2KO mice after CCl4 or BDL. Liver fibrosis in chimeric mice indicated that NOX1 mediates the profibrogenic effects in endogenous liver cells, whereas NOX2 mediates the profibrogenic effects in both endogenous liver cells and BM-derived cells. Multiple NOX1 and NOX2 components were up-regulated in activated HSCs. Both NOX1- and NOX2-deficient HSCs had decreased ROS generation and failed to up-regulate collagen α1(I) and transforming growth factor β in response to angiotensin II.

Conclusion:

Both NOX1 and NOX2 have an important role in hepatic fibrosis in endogenous liver cells, including HSCs, whereas NOX2 has a lesser role in BM-derived cells. (Hepatology 2011;)
Identification of the most influential factors in the Norwegian guidelines for risk assessment of dispersion of contaminants from sediments
Authors: Saloranta Tuomo M , Ruus Anders , Borgå Katrine 
Published: March 2011

Abstract
The Norwegian guidelines for risk assessment of contaminated sediments are used to identify areas of concern where remediation may be needed to meet the governmental long-term goal of clean fjords and harbors along the Norwegian coastline. By a thorough sensitivity analysis, this study identifies the most influential factors and parameters for the Tier 2A model in this risk guideline, which are used to estimate fluxes of contaminants from sediments due to diffusion and bioturbation (Fdiff), resuspension caused by ship traffic (Fskipnorm), and uptake and predation of benthic biota (Forg). The sensitivity analysis is run for 36 different scenarios combining 3 different sizes of contaminated area, 3 harbor types, and 3 persistent organic pollutants, namely lindane (γ-hexachlorocyclohexane), benzo[a]pyrene, and 2,2′,4,4′,5,5′-hexachlorobiphenyl (PCB-153), as well as the metal mercury (Hg). The most influential parameters vary from scenario to scenario, but generally 5 parameters appear to be particularly influential for the fluxes and transport estimated by the Tier 2A model: flux of organic carbon to sediment (OCsed), factor for increased diffusion due to bioturbation (a), sediment–water partitioning coefficient (Kd), benthic biota–water bioconcentration factor (BCFfisk), and mass of resuspended fine sediment during arrival or departure of a ship (msed). We also quantify which of the 3 fluxes (Fdiff, Fskipnorm, and Forg) dominate in the different scenarios. Our sensitivity analysis results can be used by authorities, problem owners, consultants, and environmental managers involved in contaminated sediment management to gain insight on the key processes and parameters and to focus their site-specific or laboratory-based measurement efforts on the key parameters and thus increase efficiency and reliability in the contaminated sediment risk assessment. Integr Environ Assess Manag 2011;7:657–667. © 2011 SETAC
Synthesis of new 1‐phenylthieno[1,2,4]triazolo[4,3‐a]pyrimidin‐5(4H)‐one derivatives
Authors: Song Yang‐Heon , Son Hoon Young 
Published: March 2011

AbstractA series of novel 1‐phenylthieno[1,2,4]triazolo[4,3‐a]pyrimidin‐5(4H)‐one derivatives 5 and 6 were synthesized by oxidative cyclization of thienopyrimidinonyl hydrazones using iodobenzene diacetate. J. Heterocyclic Chem., (2011).
Ten marker compounds‐based comparative study of green tea and guava leaf by HPTLC densitometry methods: Antioxidant activity profiling
Authors: Khan Imran , Sangwan Payare L. , Abdullah Sheikh Tasduq , Gupta Bhisan D. , Dhar Jagdish K. , Manickavasagar Rajendran , Koul Surrinder 
Published: March 2011

AbstractHigh‐performance thin layer chromatography (HPTLC) method for the separation and quantitative determination of ten markers (catechins, flavonoids, and phenolics) in different extracts of green tea and guava leaf has been developed and the antioxidant activity profiles of the two plant extracts have been determined. Ten marker compounds have been resolved using silica gel 60 F254 plates, toluene/acetone/formic acid (5:4:1 v/v/v) for markers 1–6, and toluene/ethyl acetate/formic acid/methanol (3:3:0.8:0.2 v/v/v/v) for markers 7–10 as the mobile phases. The high‐performance thin layer chromatography densitometry was performed at wavelengths of 282 and 285 nm for the markers 1–6 and 7–10, respectively. Potent antioxidant activity and the presence of phenolics and flavan‐3‐ols has been observed for the guava leaf extracts suggestive of its use as an alternate economical source of antioxidants over green tea – the well‐established food additive/nutraceutical agent.
Characterisation of the Chemical Composition Distribution of LLDPE Using Interactive Liquid Chromatography
Authors: Dolle Volker , Albrecht Andreas , Brüll Robert , Macko Tibor 
Published: March 2011

AbstractIt is demonstrated that copolymers of ethylene with higher 1‐olefins can be separated using bare silica gel as the stationary phase and a gradient of ethylene glycol monobutyl ether and 1,2,4‐trichlorobenzene as the mobile phase at 160 °C. The separation of ethylene 1‐hexene copolymers according to their composition is confirmed by linking the chromatographic separation to infrared spectroscopy. Using well‐characterised model fractions from temperature rising elution fractionation or solvent/non‐solvent fractionation (“Holtrup”), it can be shown that both the content and type of the comonomer mainly govern the elution in two peaks which differ in their comonomer content. The molar mass only plays a subordinate rule. magnified image
Improving the Stability in Aqueous Media of Polymer Brushes Grafted from Silicon Oxide Substrates by Surface‐Initiated Atom Transfer Radical Polymerization
Authors: Paripovic Dusko , Klok Harm‐Anton 
Published: March 2011

AbstractHydrophilic polymer brushes grown via surface‐initiated ATRP from silicon oxide surfaces are susceptible to detachment via hydrolytic cleavage of the anchoring siloxane bond. This paper investigates the influence of the structure of the ATRP initiator on the stability of these brushes and seeks for strategies to further enhance their stability. It is found that increasing the hydrophobicity of the organosilane modified ATRP initiator reduces the susceptibility of the brushes toward cleavage. Robust, hydrophilic polymer brushes are prepared, which are obtained by introducing a short, hydrophobic PMMA or PEHMA block between the silicon oxide substrate and the hydrophilic polymer brush. magnified image
A Strategy for Fabrication of Columnar Supramolecular Polymers by Highly Directional π‐π Stacking and Strong Multiple Ionic Bonds
Authors: Tao Kang , Bai Ruke , Zhao Xiulan , Wang Yanxue , Li Juan , Xue Lixin 
Published: March 2011

AbstractA columnar supramolecular HDTP/HCTP polymer is prepared by simple addition of two oppositely charged triphenylene‐based monomers. 1H NMR indicates an ordered aggregate formation with parallel stacking of the aromatic subunits in aqueous solution. UV‐Vis and fluorescence spectra imply that HDTP and HCTP self‐assemble to construct H‐aggregates, in which two monomers have a strict geometric association with each other. A fiber‐like structure (and fiber aggregates) is also found in the solid state. The microstructure of the supramolecular polymer is also studied by WAXS. Based on the analyses, a tentative model for the columnar supramolecular polymer is proposed, which suggests the importance of directional π‐π interactions and strong multiple ionic bonds. magnified image
Micromechanics of Soft Particles
Authors: Guo Mingyu , Wyss Hans M. 
Published: March 2011

AbstractMaterials that contain soft, deformable particles exhibit a rich range of macroscopic mechanical properties. Experimental access to the mechanics at the scale of a single particle is the basis for studying and understanding the macroscopic mechanics of these materials. In this paper, we discuss experimental methods that can be used to characterize the mechanics of microscopic soft particles. We focus on the recently developed capillary micromechanics method, which yields the full linear elastic behavior of a single particle. We validate the method by comparing results for the compressive modulus to osmotic compression measurements, which provide the most direct and unambiguous measure of compressibility. We find good agreement between the two methods on a system of deformable and compressible poly‐N‐isopropylacrylamide microgel particles. Our results thus support the validity of the capillary micromechanics method and suggest that it could be applied to a wide range of materials that consist of deformable soft objects. magnified image
Natural Rubber Nanocomposites by In Situ Modification of Clay
Authors: Lowe David J. , Chapman Andrew V. , Cook Stuart , Busfield James J.C. 
Published: March 2011

AbstractThe fabrication of nanocomposites by organic modification of clay during mixing into NR is reported. NR/OMMT nanocomposites show more intercalation and exfoliation at higher modifier content, increasing the tensile modulus primarily by improved filler reinforcement. Comparison with nominally identical pre‐modified OMMT shows similar microstructures and physical properties. No effect of mixing duration is observed, indicating that modification is rapid. Unlike montmorillonite, unmodified sepiolite disperses well in NR, so organo‐modification improves compatibility but does not affect the nanocomposite microstructure. This means that organo‐sepiolite offers relatively small improvements over sepiolite as a filler for NR. magnified image
Spherulite Growth Rate in Polypropylene/Silica Nanoparticle Composites: Effect of Particle Morphology and Compatibilizer
Authors: Palza H. , Vera J. , Wilhelm M. , Zapata P. 
Published: March 2011

AbstractSpherical and tube‐like (TL) silica nanoparticles were melt blended with an isotactic polypropylene (PP) matrix and its effect on the isothermal spherulite growth rate was analyzed by polarized optical microscope. The addition of low amount (≈1 wt.‐%) of either 15 nm spherical or TL particles raises the spherulite growth rate and the nucleation density of spherulites. Samples prepared with silica spheres of 80 nm otherwise do not show any change in the crystallization behavior. By adding a compatibilizer, both the nucleation density and the spherulite growth rate of the pure polymer are increased. Noteworthy, although the nanoparticles do not further increase the nucleation density of the PP/compatibilizer blend, independent of its form and size, they cause a decrease in its spherulite growth rate. magnified image
Electrogenerated Chemiluminescence of Pure Polymer Films and Polymer Blends
Authors: Chen Jiun‐Tai , Chang Ya‐Lan , Guo Song , Fabian Omar , Lackowski William M. , Barbara Paul F. 
Published: March 2011

AbstractWe recently reported the discovery of soliton‐like electrogenerated chemiluminescence (ECL) waves from pure conjugated polymer films and gold‐nanoparticles‐doped polymer films. In addition to a more detailed study of these polymer systems by changing the film thickness and the distribution of local leaks, we also apply the ECL wave phenomenon to polymer blends of conjugated and nonconjugated polymers. Poly(9,9‐dioctylfluorene‐co‐benzothiadiazole) (F8BT) is used as the active material that is oxidized and produces ECL with the presence of a co‐reactant, tri‐n‐propylamine (TPA). Several factors such as film thickness, artificial leaks, and solubility of doped polymers are examined for their effects on the ECL behavior. When polystyrene (PS), less soluble in the electrolyte, is blended with F8BT, dotted ECL signals are observed and transported as waves. When poly(methyl methacrylate) (PMMA), more soluble in the electrolyte, is blended with F8BT, PMMA serves as local scratches and ECL waves are triggered simultaneously from the whole film. magnified image
Micro‐composite systems by in‐situ polymerizations
Authors: Ogata Naoya 
Published: March 2011

AbstractIn‐situ polycondensation of terephthaloyl chloride and p‐phenylenediamine was carried out by solution or interfacial polycondensation methods in the presence of rubbers such as styrene‐butadiene triblock copolymers and acrylonitrile‐butadiene random copolymers so that a novel composite polymer of rubbers and poly(p‐phenylenetere‐phthalamide) was obtained. Mechanical properties of rubbers were greatly improved by the incorporation of rigid rod‐like polymers.In‐situ polymerization of N‐carboxy methyl‐L‐glutamate was carried out in solutions of rubbers so that a composite polymer of rubbers and poly(L‐glutamate) was obtained. Mechanical properties of rubbers were also greatly improved by the in‐situ polymerization, while solution blending of poly(L‐glutamate) did not result in the improvement of mechanical properties.
Perspectives in application of screw reactors in plastics processing
Authors: Uhland Eberhard , Wiedmann Werner 
Published: March 2011

AbstractTwin‐screw reactors have proven to be a good technical and economical solution for the synthesis of polymers and their chemical modification. The main mechanical and process criteria for the chemical reaction process for this type of reactor are discussed. Examples for products economically produced already today and an outlook for other new processes under development are given.
Highly functional nucleid analogs
Authors: Takemoto Kiichi 
Published: March 2011

AbstractSynthetic polymers having pendant nucleic acid bases were prepared by polymer design techniques. After thorough investigations on their chemical and physico–chemical properties, further studies on their applicability were done, and in particular, the analogs as photoresists, the analogs for high performance liquid chromatography, and the analogs applicable in the field of polymeric pharmaceuticals were shown.
Structural properties of partially charged poly (acrylic acid) gels as probed by light scattering
Authors: Candau Sauveur J. , Skouri Rachid , Schosseler François , Munch Jean‐Pierre 
Published: March 2011

AbstractWe report results of static light scattering for partially charged gels at different swelling degrees and different ionization degrees. We measured both the ensemble‐average and the rms fluctuations of the scattered intensity by scanning through various positions in the gel. It is shown that the dynamic concentration fluctuations are, to the first order, the same as in semi‐dilute solutions at the same concentration. The excess of scattering of the gel with respect to the solutions arises mainly from frozen‐in scattering domains with spatial extent less than ∼ 300 Å.
Structure of cellulose in cuoxam
Authors: Seger Bernd , Burchard Walther 
Published: March 2011

AbstractCuoxam ([CuII(NH3)4](OH)2) is a well known solvent for cellulose. Because of its deep blue colour, it has been used so far only for viscosity measurements. Direct light scattering measurements have not yet been reported in the literature.We carried out static and dynamic light scattering measurements in cuoxam using the blue wavelength of λ0 = 457.9 nm from an Argon ion laser. The measurements were involved with some difficulties mainly caused by colloidal particles of CuO and Cu(OH)2 which could be removed by direct centrifugation of the cells. Furthermore, the scattering intensity had to be corrected for extinction. The refractive index increment was taken from the literature.12 samples of different molecular weight and different origin were measured, and common power law behavior was found in a region up to about DPw = 1000 for both, the radius of gyration Rg and the hydrodynamic radius Rh, derived from the diffusion coefficient Dz. At higher degrees of polymerization characteristic deviations to lower radii occurred.These deviations are not caused by aggregation since the DPw's agreed with those from the cellulose tricarbanilates. The quantitative analysis of the radii and the angular dependence of the scattered light allowed determination of the chain stiffness. A Kuhn segment length of Ik = 25.6 (±6.2) nm and a characteristic ratio C∞ = 49.6 (±12.0) were derived. These values are close to those for cellulose‐tri‐carbanilate in dioxane.The reason for the increased stiffening is discussed on the basis of a special H‐bond model.
Alternating copolymerizations of 9,10–dicarbonyl–9,10–dihydroanthracene with 1,4–benzoquinones and 1,4–benzoquinone diimines: A novel preparative route to polyarylate and polyaramide
Authors: Iwatsuki Shouji , Itoh Takahito , Kozaki Masahiko 
Published: March 2011

AbstractThe anthracene–9, 10–bisketene compound 9, 10‐dicarbonyl‐9, 10–dihydroanthracene (1) was found to react spontaneously with a variety of benzoquinones and benzoquinone diimines to give aromatic polyesters and polyamides, respectively. These addition reactions are regarded as a novel preparative route to polyarylate and polyaramide.
Synthesis and properties of metal poly(butyl methacrylates) 7
Authors: Galo Cárdenas T. , Hernán Carbacho H. , Elizabeth Salgado C. , MarioRodriguez B. 
Published: March 2011

AbstractMetal butyl methacrylate colloids were obtained by codeposition at 77K of the monomer with several metals such as Au, Pd, Cu, Ag, Zn, Cd, Ga, In, Ge, Sn, Sb and Bi. Au and Pd colloids are stable tor months at room temperature. The colloids were polymerized with different amounts of initiator benzoyl peroxide at 65°C for 25 min and a wide range of viscosity‐average molecular weights (103 <M̄v < 105) were obtained depending upon the metal used. The particle size of the clusters dispersed in the polymer matrix is around 500 A°. The polymers are stable even at 300°C, being Pd‐poly(butyl methacrylate) the most stable with 388.90°C. The metal content is ranging from 0.02 to 1.65 wt% for Sb and Pd, respectively. Polymers with different colors were obtained depending on the metal used.
Charge transport polymers for organic electroluminescent devices
Authors: Kido Junji , Hongawa Kenichi , Nagai Katsutoshi , Okuyama Katsuro 
Published: March 2011

AbstractTriple‐layer‐type organic electroluminescent devices were fabricated using charge‐transporting poly(N‐vinylcarbazole) (PVK) as a hole‐transporting emitter layer. Electron‐transporting layers consisting of a triazole derivative (TAZ) and an aluminum complex (Alq) layer were used to maximize the carrier recombination efficiency. The EL device with a structure of glass substrate/indium‐tinoxide/PVK/TAZ/AIq/Mg:Ag showed bright blue emission from the PVK layer with a luminance of over 700 cd/m2. The emission color was tuned to a desirable color in the visible region through doping the PVK layer with fluorescent dyes. Bright white emission, in particular, was obtained for the first time at a high luminance level of over 3000 cd/m2 by using three kinds of fluorescent dyes each emitting red, green or blue.
Stereocomplex formation of isotactic poly(methyl methacrylate) with a wide variety of syndiotactic polymethacrylates
Authors: Hatada Koichi , Kitayama Tatsuki , Ute Koichi , Fujimoto Nobutaka , Miyatake Nobuo 
Published: March 2011

AbstractSyndiotactic (st–) polymers of methacrylates with primary and secondary ester groups, prepared by the syndiotactic‐specific living polymerization with t‐C4H9Li/R3Al, were found to form stereocomplexes with isotactic (it–) poly(methyl methacrylate) (PMMA) by annealing in the solid state or by mixing in certain solvents such as acetone and toluene. Melting points of the complexes depend on the structure of the ester group and can be changed in a wide range of temperature. st–Polymers of tertiary esters did not form the complex. Effects of anneal conditions, molecular weight, and tacticity on the melting point of the complex were studied in some detail for the combination of st–poly(benzyl methacrylate) and it–PMMA. st–Random copolymers of MMA with several alkyl methacrylates also formed stereocomplexes with it–PMMA, whose melting point could be changed continuously by changing the composition in a certain range of temperature. st–Block copolymers of PMMA and poly(benzyl methacrylate) formed stereocomplexes with it–PMMA which showed two melting points, provided the block lengths are long enough for the two types of the com plexes to form independently. Stereoblock PMMA, it–PMMA–block–st–PMMA, and stereoblock copolymer, it–PMMA–block–st–poly(butyl methacrylate), were found to form stereocomplexes more easily than the corresponding mixtures. The stereoregular uniform PMMAs were used for elucidating the process of stereocomplex formation and its stoichiometry by means of gelpermeation chromatography (GPC). The preliminary results clearly indicated that the complexation occurs mainly in 1:1 stoichiometry in the beginning, while a small fraction of 1:2 (it–: st–) complex was also formed concomitantly. By similar GPC experiments using a series of uniform PMMAs, the minimum length of PMMA chains for the complex formation was found to be in the range of degrees of polymerization from 42 to 46.
Molecular design and synthesis of novel side‐chain liquid crystalline polymers
Authors: Kawakami Yusuke 
Published: March 2011

AbstractNovel side‐chain liquid crystalline polymers were synthesized based on the molecular design of the chemical structures of main‐chain, spacer, and mesogenic groups. The main‐chain structures are polyether, by the cationic ring‐opening polymerization of oxetane derivatives, and polydiene, by the radical polymerization of diene derivatives. Some of the polymers from oxetanes with various mesogen and spacer groups show smectic liquid crystalline phase. Both cyano‐ and fluorine‐substituted biphenyls are good mesogenic groups in these liquid crystalline polymers. Polydiene also acts as a novel main‐chain to give smectic liquid crystalline state with cyanobiphenyl or fluorobiphenyl as a mesogen. Not only oligomethylene groups but also siloxane and oligo(oxyethylene) groups act as a component of the spacer groups to give liquid crystalline state.