bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of physicochemical properties of carotenoids on their bioaccessibility, intestinal cell uptake, and blood and tissue concentrations
Authors: Sy Charlotte , Gleize Beatrice , Dangles Olivier , Landrier Jean‐François , Veyrat Catherine Caris , Borel Patrick 
Published: July 2012

ScopeCarotenoid bioavailability is affected by numerous factors. Our aim was to assess the involvement of known carotenoid physicochemical properties (e.g., hydrophobicity, van der Waals volume,…) on the transport of the main dietary carotenoids (β‐carotene, lycopene, lutein, and astaxanthin, from their food matrix to their main storage tissues.Methods and resultsWe used four complementary models: synthetic mixed micelles, an in vitro digestion procedure, Caco‐2 cell monolayers, and a gavage experiment in rats. The efficiency with which pure carotenoids were incorporated into synthetic mixed micelles was related to their melting points (r = 0.99, p = 0.015). The efficiency with which pure carotenoids were transferred from dietary triglycerides into mixed micelles was related to carotenoid hydrophobicity (r = −1, p = 0.005). There was no relationship between the carotenoid physicochemical properties studied and their uptake efficiency by Caco‐2. The postprandial plasma carotenoid response to carotenoid gavage was related to carotenoid hydrophobicity (r = −0.99, p = 0.006). Carotenoid adipose tissue response was not related to the carotenoid physicochemical properties studied.ConclusionThus, carotenoid hydrophobicity is important for bioaccessibility and postprandial blood response of carotenoids. In contrast, the carotenoid physicochemical properties studied are apparently not strong determinants of carotenoid uptake by enterocytes and adipose tissue.
On the optimization of flux limiter schemes for hyperbolic conservation laws
Authors: Breuß Michael , Dietrich Dominik 
Published: July 2012

AbstractA classic strategy to obtain high‐quality discretizations of hyperbolic partial differential equations is to use flux limiter (FL) functions for blending two types of approximations: a monotone first‐order scheme that deals with discontinuous solution features and a higher order method for approximating smooth solution parts. In this article, we study a new approach to FL methods. Relying on a classification of input data with respect to smoothness, we associate specific basis functions with the individual smoothness notions. Then, we construct a limiter as a linear combination of the members of parameter‐dependent families of basis functions, and we explore the possibility to optimize the parameters in interesting model situations to find a corresponding optimal limiter. © 2012 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2013
SP1 mediates the link between methylation of the tumour suppressor miR‐149 and outcome in colorectal cancer
Authors: Wang Feng , Ma Yan‐Lei , Zhang Peng , Shen Tong‐Yi , Shi Chen‐Zhang , Yang Yong‐Zhi , Moyer Mary‐Pat , Zhang Hui‐Zhen , Chen Hong‐Qi , Liang Yong , Qin Huan‐Long 
Published: July 2012

AbstractAlthough recent studies indicate that DNA methylation contributes to the down‐regulation of microRNAs (miRNAs) in colorectal cancer (CRC), this field remains largely unexplored. To identify methylation‐silenced miRNAs and clarify their role in CRC, we performed a microarray analysis and screened for miRNAs that were induced in CRC cells by 5‐aza‐2′‐deoxycytidine treatment or by the knockdown of DNA methyltransferases. The DNA methylation status of the candidate miRNA was analysed by bisulphite sequencing PCR and methylation‐specific PCR. We found that miRNA‐149 (miR‐149) was epigenetically silenced in CRC and down‐regulation of miR‐149 was associated with hypermethylation of the neighbouring CpG island (CGI). Quantitative RT‐PCR analysis demonstrated that the miR‐149 level was markedly reduced in 51.6% of the CRC tissues compared with matched non‐cancerous tissues. In addition, low expression of miR‐149 was associated with a greater depth of invasion ($\it{p} = 0.012$), lower 5‐year survival rate ($\it{p} = 0.025$), and was found to be an independent prognostic factor for overall survival ($\it{p} = 0.016$) in a multivariate analysis. Moreover, transfection of miR‐149 inhibited cell growth and invasion of CRC cells in vitro. We also identified mRNA for Specificity Protein 1 (SP1, Sp1), a potential oncogenic protein, as a target of miR‐149. Our data suggest that, as a methylation‐sensitive miRNA, miR‐149 may play an important role as a tumour suppressor in CRC, which has prognostic and therapeutic implications. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Effect of silane coupling agent on the durability of epoxy adhesion for structural strengthening applications
Authors: Choi Sungwon , Maul Scott , Stewart Andrew , Hamilton H.R. , P. Douglas Elliot 
Published: July 2012

AbstractIn this article, the durability of the interfacial bonds between epoxy and concrete during hygrothermal exposure was investigated. Through the application of a silane coupling agent, we examined the hypothesis that hydrogen bonding plays a large role in the degradation of the interfacial bond between epoxy and concrete, in which displacement of epoxy with water induces the disruption of the interfacial hydrogen bond. This hypothesis suggests that durability can be enhanced with the use of a silane coupling agent by changing the interfacial hydrogen bonds to stronger covalent bonds. The slant shear test results show that the durability of the interfacial bond was significantly enhanced with the use of an epoxy‐functional silane coupling agent. Spectroscopic features using FTIR confirmed the changes in chemical nature of concrete after the silane modification. By calculating the percent contribution to the bond strength for each set of specimens, it was confirmed that the silane application improved the durability with exposure for all conditions; however, over time the improvement diminished. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers
Fluorescence quenching of fluoranthene by maleic anhydride in solution and during nonreactive and reactive twin‐screw extrusion
Authors: Methenni Amine , Mighri Frej , Elkoun Saïd , Fang Haixia , Cassagnau Philippe 
Published: July 2012

AbstractFluorescence quenching of fluoranthene by maleic anhydride (MAH) in polypropylene (PP) during twin‐screw extrusion (TSE) was investigated using an online fluorescence measurement system. The fluorescence quenching effect was clearly seen from the decrease of the peak intensity and integrated area of the residence time distribution (RTD) curves when MAH was introduced into PP. Fluorescence quenching effect in TSE was compared with that in chloroform solution and in both cases, it followed the linear Stern‐Volmer equation although it showed lower quenching effect in TSE than in solution. Using this quenching phenomenon, it was possible to measure online the grafting degree of PP with MAH in the TSE. The obtained results showed that MAH grafting degree and total conversion measured by both fluorescence technique and by Fourier transform infrared spectroscopy were in good agreement for MAH weight concentrations up to 0.8 wt%. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers
Effects of nanotube modification on the dielectric behaviors and mechanical properties of multiwall carbon nanotubes/epoxy composites
Authors: Guo Xiusheng , Yu Demei , Wu Jingshen , Min Chao , Guo Rongnan 
Published: July 2012

AbstractMultiwall carbon nanotubes (MWNTs) were modified by three methods, namely, oxidizing the tubes and opening both ends, filling the tubes with Ag, and grafting the tubes with hexamethylene diamine. Modified MWNTs/epoxy composites were prepared by melt‐mixing epoxy resin with the tubes. Transmission electron microscope images showed that the modified MWNTs can be dispersed in the epoxy matrix homogeneously. The dielectric behaviors and mechanical properties of the composites were investigated. The dielectric and mechanical properties of the modified MWNTs/epoxy composites were considerably improved compared with those of the epoxy matrix. The tensile strengths of the Ag‐filled, opened, and grafted MWNTs composites at the same filler content of 1.1 wt% were higher by ∼30.5%, 35.6%, and 27.4%, respectively, than that of neat epoxy. The Izod notched impact strength of the grafted MWNTs/epoxy composite with filler content of 1.1 wt% was approximately four times higher than that of neat epoxy. A dielectric constant of ∼150 of the composite with 1.1 wt% Ag‐filled nanotubes was observed in the low‐frequency range, which was ∼40 times higher than that of the epoxy matrix. The proper modification of nanotubes provides a way to improve the properties of the polymer‐based composites. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers
Thermo‐sensitive electrospun fibers prepared by a sequential thiol‐ene click chemistry approach
Authors: Yang Hong , Zhang Qi , Lin Baoping , Fu Guodong , Zhang Xueqin , Guo Lingxiang 
Published: July 2012

AbstractThis manuscript describes a straightforward method to prepare stimuli‐responsive fibers by the combined technology of electrospinning and two facile thiol‐ene click chemistry processes: photo‐initialized thiol‐ene radical addition and thiol‐Michael nucleophilic addition. By controlling the molar ratio of poly((3‐mercaptopropyl)methylsiloxane) (PMMS) and the cross‐linker, triallyl cyanurate, PMMS‐based fibers can be partially photo‐crosslinked via UV illumination during electrospinning, to grant them the solvent‐resistant property, meanwhile leaving unreacted free mercapto groups on the surfaces, which could be further functionalized with stimuli‐responsive polymer brushes. To demonstrate the feasibility of this approach, a facile thiol‐Michael addition protocol between PMMS fibers with free thiol groups on the surfaces and maleimide‐terminated PNIPAM has been developed, which allows for the preparation of polysiloxane fibers with thermo‐responsive PNIPAM brushes on the surfaces. PMMS‐g‐PNIPAM fibers show thermo‐sensitive behavior to the environment, having a hydrophilic surface at 20°C (water contact angle ∼28°) and a hydrophobic surface at 45°C (water contact angle ∼132°). © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012.
Copper‐mediated initiators for continuous activator regeneration atom transfer radical polymerization of acrylonitrile
Authors: Liu Xiao‐hui , Wang Jin , Zhang Fei‐jun , An Shu‐lin , Ren Yuan‐lin , Yu Yun‐hai , Chen Peng , Xie Shan 
Published: July 2012

AbstractInitiators for continuous activator regeneration atom transfer radical polymerization technique was first accessed to acrylonitrile by using CuBr2/2,2′‐bipyridine as the catalyst, ethyl 2‐bromoisobutyrate as the halogen initiator, and azobis(isobutyronitrile) as the free radical initiator. The key to success is ascribed to the facile achievement of the rapid equilibrium between active species and dormant species. Effects of ligand, catalyst concentration, free radical initiator concentration, and reaction temperature on the polymerization reaction and molecular weight (MW) as well as polydispersity index (PDI) were investigated in detail. The polymerization proceeded in a controlled/living fashion even though the concentration of copper catalyst decreased to 50 ppm, which is evident in pseudo first‐order kinetics of polymerization, linear increase of molecular weight, low PDI, and high chain‐end functionality of the generated polymer. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Elucidation of the mechanism of surface‐initiated atom transfer radical polymerization from a diazonium‐based initiator layer
Authors: Chernyy Sergey , Iruthayaraj Joseph , Ceccato Marcel , Hinge Mogens , Pedersen Steen Uttrup , Daasbjerg Kim 
Published: July 2012

AbstractThis study elucidates the influence of the atom transfer radical polymerization initiator structure, monolayer versus disordered multilayer, on the growth kinetics and the structural transition of poly(methyl methacrylate) (PMMA) brush layers. The multilayer initiator film, prepared by acylation of the electrografted 2‐phenylethanol layer using 2‐bromoisobutyryl bromide, consists of ∼4.6 times more tert‐butyl bromide groups compared to monolayer initiator prepared by self assembly technique. The results demonstrate the formation of precursor complex between CuI catalyst and the bromine initiator as a prerequisite step before the onset of polymerization. Furthermore, the PMMA brushes formed by the polymerization from the multilayered initiator layer at 50 °C are 20‐fold thicker compared to the polymerization at 25 °C due to the swelling of the multilayered initiator film. In contrast, the thickness of the PMMA layer on the monolayer initiator is less affected by the polymerization temperature. By varying the initiator density on the surface, the solvent content in the PMMA layer is shown to vary from 15% to 94%, resulting in the transition from concentrated over semidiluted to diluted brushes. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Morphosynthesis of poly[4‐(1,4‐phenylene)oxyphthalimide] and copolymers prepared by reaction‐induced crystallization during polymerization
Authors: Sawai Takashi , Wakabayashi Kanji , Yamazaki Shinichi , Uchida Tetsuya , Kimura Kunio 
Published: July 2012

AbstractMorphosynthesis of poly[4‐(1,4‐phenylene)oxyphthalimide] (POPI) and poly[4‐(1,4‐phenylene)oxyphthalimide‐co‐4‐phthalimide] (POPI‐PPI) was examined by using the crystallization during the polymerization. The POPI fibrillar crystals were obtained as precipitates with the formation of spherical aggregates of plate‐like crystals. Some of the POPI fibrillar crystals were longer than 15 μm. They possessed high crystallinity and the molecules aligned perpendicular to the long direction of the fibers. On the other hand, one‐dimensional structures of POPI‐PPI such as ribbon, cone, rod, and fiber were obtained as precipitates by the copolymerization. The copolymer molecules might align along the long direction of the cone‐like crystals. The morphology of these poly(ether‐imide)s could be controlled by not only the polymerization condition but also with the aid of copolymerization. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012
Agriculture Grade Ammonium Nitrate as the Basic Ingredient of Massive Explosive Charges
Authors: Zygmunt Bogdan , Buczkowski Daniel 
Published: July 2012

AbstractPrilled ammonium nitrate (AN) is manufactured globally in millions of tons and is mainly used as fertilizer or as the main ingredient of modern mining blasting explosives. The availability of AN poses a serious threat to public security as it enables preparation of massive explosive charges using a simple technology in order to carry out terrorist attacks. This paper examines the option of using agriculture AN manufactured in several Polish plants as the basic ingredient of explosive mixtures with liquid fuels or powdered aluminum. Fuel oil (FO), 2‐EHN and nitromethane were used as liquid fuels. Additionally, the effect of an inorganic additive (dolomite) in AN on the detonation velocity of mixtures of granulated and milled AN with various fuels was examined.
Effect of Porphyrin Doping on Thermodynamic Parameters of Pentaerythritol Tetranitrate (PETN) Single Crystals
Authors: Hikal Walid M. , Bhattacharia Sanjoy K. , Weeks Brandon L. 
Published: July 2012

AbstractThe search for ways to enhance the stability of PETN against sublimation and coarsening, as well as controlling its thermodynamic properties, is of great interest. In this article, the possibility to use biological molecules to enhance the stability of the important explosive PETN was investigated using thermogravemitric analysis (TGA). Doping PETN with free and metallated porphyrins result in the formation of more stable crystals. Hydrogen bonding between free porphyrins and metal coordination of metallated porphyrins is most likely to play an important role in the crystallization process of PETN. The results indicate the ability of porphyrins molecules to affect/control the thermodynamic properties of PETN inducing a desired higher stability against sublimation. This study opens the door to investigate the use of polymers to enhance the stability of energetic materials.
External validation of the updated briganti nomogram to predict lymph node invasion in prostate cancer patients undergoing extended lymph node dissection
Authors: Hansen Jens , Rink Michael , Bianchi Marco , Kluth Luis A. , Tian Zhe , Ahyai Sascha A. , Shariat Shahrokh F. , Briganti Alberto , Steuber Thomas , Fisch Margit , Graefen Markus , Karakiewicz Pierre I. , Chun Felix K.‐H. 
Published: July 2012

AbstractPURPOSEWe aimed to test accuracy and generalizability of a recently updated nomogram to assess the probability of lymph node invasion (LNI), when applied to a different European cohort of men undergoing radical prostatectomy (RP) with extended pelvic lymph node dissection (ePLND).MATERIALS AND METHODSThe study cohort consisted of 1,282 men with clinically localized PCa who underwent RP and ePLND, including removal of obturator, external iliac, and hypogastric lymph nodes, between 01/2007 and 08/2011. Descriptive measurements included preoperative clinical and biopsy variables, such as prostate‐specific antigen (PSA), clinical stage (CS), primary and secondary biopsy Gleason pattern, and percentage of positive cores. We used the area under curve (AUC) of the receiver operator characteristic analysis to quantify accuracy of the model to predict LNI. The extent of over‐ or under‐estimation was explored graphically within loess calibration plots.RESULTSThe median number of removed lymph nodes was 15 with an interquartile range of 12–20. Twelve percent (n = 155) of men had LNI. Preoperative clinical and biopsy characteristics differed significantly (all P ≤ 0.002) between men with LNI and those without. External validation of the previously reported updated LNI nomogram showed very good accuracy (AUC: 0.829). A nomogram‐derived cut‐off of 4% could lead to a reduction of 48% of lymph node dissection, while missing 10% of patients with LNI.CONCLUSIONSWe report the external validation of an updated LNI nomogram, demonstrating accuracy and applicability in a different European cohort. A nomogram‐derived cut‐off of 4% confirmed good performance characteristics within a different external validation cohort. Prostate 73: 211–218, 2013. © 2012 Wiley Periodicals, Inc.
Large electrostrictive effect in K0.99Li0.01Ta1−xNbxO3 lead‐free single crystals
Authors: Tian Hao , Jia Jieshu , Zhou Zhongxiang , Chen Deying 
Published: July 2012

AbstractParaelectric K0.99Li0.01Ta1−xNbxO3 (x = 0.38, 0.39, 0.40) lead‐free single crystals have been grown by the top‐seeded solution growth method. All the crystals have Curie temperature (Tc) close to room temperature (RT), and possess large relative dielectric constants near Tc. A scanning Michelson interferometer was used to investigate the electrostrictive (ES) behavior of the crystals. The crystals show pure ES characteristics and large electrosrictive coefficients. The ES coefficient Q11 of K0.99Li0.01Ta0.60Nb0.40O3 reaches as high as 0.12 m4/C2, about six times of the value of Pb(Mg1/3Nb2/3)O3 ceramics.
Atomic and electronic structure of rigid carbon atomic chains
Authors: Usanmaz D. , Srivastava G. P. 
Published: July 2012

AbstractWe have reported, from ab initio calculations, on the changes in the electronic and structural properties of short carbon atomic chains held rigidly between hydrogenated armchair graphene nanoribbons (AGNR) and zig‐zag graphene nanoribbons (ZGNR). Several lengths (N = 2–9 atoms) and forms of the chains have been considered. All models are found to be metallic in nature, with chemical bonding more like $\cdots {\rm C}- {\rm C}\equiv {\rm C}- {\rm C}\equiv {\rm C}\cdots $ (as in polyyne) for odd‐numbered chains and $\cdots {\rm C} = {\rm C} = {\rm C} = {\rm C}\cdots $ (as in cumulene) for even numbered chains. An examination of the variation of the density of states (DOS) near the Fermi level with chain length suggests the possibility for tunability of the metallic property of short carbon chains.
Hydrogen in C‐rich Si and the diffusion of vacancy–H complexes
Authors: Estreicher S. K. , Docaj A. , Bebek M. B. , Backlund D. J. , Stavola M. 
Published: July 2012

AbstractThe sites, gap levels, and migration barriers of interstitial H in Si are predicted. The hydrogenation of C‐rich Si results in the formation of H2*(C) and C2H2, in contrast to FZ‐Si where H2 molecules dominate. The fully saturated vacancy (VH4) also forms. This complex is normally stable up to 650 °C. However, in C‐rich Si, VH4 anneals around 550 °C while the VH3HC complex appears. There, C replaces one of the four Si nearest‐neighbors to the vacancy. This implies that VH4 begins to diffuse at 550 °C, and then traps at Cs. This in turn implies that all the VHn complexes (n = 1, 2, 3, 4) are mobile at moderate temperatures. In this paper, we discuss the energetics of H in Si, summarize the key experimental and theoretical results about H interactions in C‐rich Si, and discuss the migration paths and activation energies of the four VHn complexes.
Interfacial doping for efficient charge injection in organic semiconductors
Authors: Lee Jae‐Hyun , Kim Jang‐Joo 
Published: July 2012

AbstractInterfacial doping in organic semiconductors (OSs) is an important technique to achieve efficient organic electronic devices. In this paper, we discuss how the charge injection into an OS can be enhanced by the insertion of a thin interfacial layer or an electrically doped OS layer between an electrode and an undoped OS. We present that the vacuum level shift and Fermi level modification by the electrical doping is the origin of the efficient charge injection through a metal–organic junction and an organic–organic junction. Application to organic electronics such as organic light‐emitting diodes (OLEDs) and organic photovoltaics (OPVs) is briefly summarized.