bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and morphology transformation of amphiphilic diblock polyurethane copolymers in aqueous solution
Authors: Miao Qing , Jin Yong , Dong Yang , Cao Zhifeng , Zhang Biao 
Published: May 2010

AbstractAmphiphilic block copolymers possess both hydrophobic and hydrophilic properties and can form versatile micellar structures in aqueous solution. The aim of the research presented was to prepare a series of non‐ionic amphiphilic diblock polyurethane copolymers (PUn) based on isophorone diisocyanate, monoallyl‐end‐capped poly(ethylene oxide) and poly(propylene oxide) (PPO), followed by an investigation of their micellization properties and morphology transformation in aqueous solution. The PUn samples were synthesized by condensation polymerization. These polyurethanes exhibit surface tension as low as 33.7–37.0 mN m−1. There is an obvious decrease in critical micelle concentration as the hydrophobic PPO molecular weight increases. According to transmission electron microscopy, the morphology of aggregates of the copolymers can be tuned by varying the concentration in aqueous solution rather than organic solvent. For example, for PU7, large compound micelles are produced instead of vesicles. For PU17, the concentration can be used to control the size and thickness of vesicles. Vesicle size increases from 60 to 500 nm and vesicle thickness from 40 to 60 nm with concentration ranging from 0.003 to 0.03 wt%. The study shows that the copolymers in aqueous solution have excellent surface activities. In addition, they can self‐assemble into large compound micelles or vesicles at certain concentrations. Moreover, the synthesis method described allows one to obtain a desired morphology of aggregates by adjusting the composition of hydrophilic and hydrophobic segments, which provides a novel and simple way to obtain particles on the nanometer scale. Copyright © 2010 Society of Chemical Industry
Nanocomposite coatings via simultaneous organic–inorganic photo‐induced polymerization: synthesis, structural investigation and mechanical characterization
Authors: Belon Cindy , Chemtob Abraham , Croutxé‐Barghorn Céline , Rigolet Séverinne , Schmitt Marjorie , Bistac Sophie , Le Houérou Vincent , Gauthier Christian 
Published: May 2010

AbstractHybrid sol–gel films were prepared via a simultaneous organic‐inorganic UV‐curing process using a diaryliodonium salt as a superacid photogenerator. In this single‐step procedure, an epoxy functionalized reactive resin mixed with a variable amount of either of two epoxy trialkoxysilane precursors was UV‐irradiated, causing both the initiation of epoxy ring‐opening copolymerization and the catalysis of trialkoxysilyl sol–gel reactions. The concomitant photo‐induced sol–gel process was found to have a significant effect on the two related propagation mechanisms in competition for the oxirane ring‐opening—the active chain‐end and the activated monomer mechanisms—as proved by a systematic examination of the hybrid material microstructure through 29Si and 13C solid‐state NMR spectroscopy. The effect of the oxo‐silica network generation on the epoxy reaction kinetics was also evaluated using real‐time Fourier transform infrared spectroscopy upon varying the epoxysilane structure and its concentration. Thermal and dynamic mechanical analyses were systematically performed on these hybrids, by studying thoroughly their structure–property interdependence. Other mechanical characterizations through tribological and scratch tests suggested that the present photopolymer–silica hybrid material provides a powerful tool to tailor mechanical property profiles. Copyright © 2010 Society of Chemical Industry
Patient's perceived need and psychological distress and/or quality of life in ambulatory breast cancer patients in Japan
Authors: Akechi Tatsuo , Okuyama Toru , Endo Chiharu , Sagawa Ryuichi , Uchida Megumi , Nakaguchi Tomohiro , Akazawa Terukazu , Yamashita Hiroko , Toyama Tatsuya , Furukawa Toshiaki A. 
Published: May 2010

AbstractObjective: A needs assessment can be used as a direct index of what patients perceive they need help with. The purposes of this study were to investigate the association between patients' perceived needs and psychological distress and/or quality of life (QOL) and to clarify the characteristics of patients with a high degree of unmet needs.Methods: Randomly selected ambulatory female patients with breast cancer participated in this study. The patients were asked to complete the Short‐form Supportive Care Needs Survey questionnaire, which covers five domains of need (health system and information, psychological, physical, care and support, and sexuality needs); the Hospital Anxiety and Depression Scale; and the European Organization for Research and Treatment of Cancer QLQ‐C 30.Results: Complete data were available for 408 patients. The patients' needs were significantly associated with both psychological distress (r=0.63, p<0.001) and QOL (r=−0.52, p<0.001). A multiple regression analysis revealed that employment status (without full‐time /part‐time job), duration since diagnosis (less than 6 months), advanced stage, and a lower performance status were significantly associated with higher total needs. Only sexuality needs were significantly associated with a younger age, while the other domains were significantly associated with duration since diagnosis, advanced stage, and a lower performance status.Conclusions: Moderate to strong associations exist between patients' needs and psychological distress and/or QOL. The characteristics associated with patients' needs are multi‐factorial, and interventions to respond to patients' needs may be one possible strategy for ameliorating psychological distress and enhancing QOL. Copyright © 2010 John Wiley & Sons, Ltd.
The Meaning‐Making intervention (MMi) appears to increase meaning in life in advanced ovarian cancer: a randomized controlled pilot study
Authors: Henry Melissa , Cohen S. Robin , Lee Virginia , Sauthier Philippe , Provencher Diane , Drouin Pierre , Gauthier Philippe , Gotlieb Walter , Lau Susie , Drummond Nancy , Gilbert Lucy , Stanimir Gerald , Sturgeon Jeremy , Chasen Martin , Mitchell Julie , Huang Lina Nuoxin , Ferland Mira‐Klode , Mayo Nancy 
Published: May 2010

AbstractObjective: This pilot study aimed to provide supportive evidence for the acceptability and usefulness of the Meaning‐Making intervention (MMi) in patients newly diagnosed with Stage III or IV ovarian cancer, and to provide estimates of parameters needed to design a full‐scale study.Methods: A randomized controlled trial with 24 patients (12 experimental and 12 control) was conducted. Existential well‐being (primary outcome), overall quality of life, distress, anxiety, depression and self‐efficacy were measured.Results: Compared to the control group, patients in the experimental group had a better sense of meaning in life at one and three months post‐intervention.Conclusion: The MMi seems a promising intervention for advanced cancer patients, and a full randomized controlled trial is warranted to further investigate its efficacy. Copyright © 2010 John Wiley & Sons, Ltd.
Glass‐substrate‐based high‐performance ZnO‐TFT by using a Ta2O5 insulator modified by thin SiO2 films
Authors: Zhang L. , Li J. , Zhang X. W. , Yu D. B. , Jiang X. Y. , Zhang Z. L. 
Published: May 2010

AbstractThin SiO2 films were used to modify the Ta2O5 insulator (STS) in the ZnO‐TFTs fabricated at room temperature by RF magnetron sputtering. The performance of the device was obviously improved after adding thin SiO2 layers, such as: enhancement of on/off ratio by one order of magnitude, reduction of the subthreshold swing from 0.32 to 0.28 V/dec, increase of the field effect mobility (from 46.2 to 52.4 cm2/V s), as well as reduction of the hysteresis in IDS versus VGS curves and capacitance–voltage characteristics. The capacitance–voltage and C−2 versus voltage characteristics were investigated, from which the trapped charge density at or near the interface between insulator and ZnO layer as well as the carriers concentration of the ZnO film are calculated. The performance enhancements are attributed to the reduce of leakage current, smoother surface morphology, and suppress of charge trapping by using SiO2 films to modify the high‐κ Ta2O5 dielectric.
Structural analysis of nitride‐based LEDs grown on micro‐ and nano‐scale patterned sapphire substrates
Authors: Su Y. K. , Chen J. J. , Lin C. L. , Kao C. C. 
Published: May 2010

AbstractThe structural properties of nitride‐based light‐emitting diodes (LEDs) grown on micro‐ and nano‐scale patterned sapphire substrates (PSS) were discussed in detail. The high resolution X‐ray diffraction (HRXRD) and etch‐pit density (EPD) results reveal that the crystalline quality of the epitaxial GaN film could be effectively improved by using the PSS technique, and depended on the aspect ratio of PSS. The crystalline quality of epitaxial GaN films grown on PSS‐2μm and PSS‐3μm was better than that of the LED grown on NPSS. The electrical characteristics and junction temperature results of the LED grown on micro‐scale PSS were better compared with nano‐scale PSS. But the output power of the LED grown on nano‐scale PSS was larger than that of the LED grown on micro‐scale PSS since the pattern‐size of PSS is related to the capability of light extraction. However, when the spacing of PSS is less than 2 μm, some voids formed at the GaN/sapphire interface may cause the thermal dissipation problem of LEDs. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Exciton localization in Al‐rich AlGaN ternary alloy epitaxial layers
Authors: Murotani Hideaki , Yamada Yoichi , Taguchi Tsunemasa , Kato Ryo , Yokogawa Toshiya 
Published: May 2010

AbstractExciton localization in Al‐rich AlGaN ternary alloy epitaxial layers has been studied by means of temperature‐dependent photoluminescence (PL) spectroscopy. Anomalous temperature dependence of the PL peak energy (red‐blue shift) was observed, which enabled us to estimate the localization energy of excitons. The localization energy increased as the 1.2th power of the exciton linewidth. The value of exponent for Al‐rich alloys was smaller than that for Ga‐rich alloys. This indicated that the excitons in Al‐rich alloys were strongly localized compared to that in Ga‐rich alloys. In addition, the exponent value for Al‐rich alloys increased with increasing excitation power density. This increase in the exponent suggested that the exciton population approached the extended states owing to the saturation of localized states by photo‐generated excess excitons. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth of In‐rich and Ga‐rich InGaN alloys by MOCVD and fabrication of InGaN‐based photoelectrodes
Authors: Liu Bin , Luo Wenjun , Zhang Rong , Zou Zhigang , Xie Zili , Li Zhaosheng , Chen Dunjun , Xiu Xiangqian , Han Ping , Zheng Youdou 
Published: May 2010

AbstractThe growth of In‐rich and Ga‐rich InGaN alloys on GaN templates by metal‐organic chemical vapor deposition was investigated. The In content x of InxGa1‐xN is determined by measuring the interplanar spacings of (0002) using high resolution X‐ray diffraction, which agrees with absorption edges obtained by optical transmission measurement. It is found the Ga‐rich InGaN alloys have better crystalline quality, lower background electron concentration and stronger band to band photoluminescence compared than the In‐rich InGaN alloys. The band gap bowing parameter b = 1.31 eV is obtained by fitting the band gap of InxGa1‐xN alloys as function as In content x. The InGaN‐based photoelectrodes were fabricated. The photoelectrodes working in aqueous HBr solution exhibit response to visible light. The incident photon conversion efficiency (IPCE) of an In0.2Ga0.8N photoelectrode achieves up to 9%, which provides one way to utilize solar energy (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Solvation of anionic water‐soluble porphyrins: A computational study
Authors: Guizado Teobaldo R. Cuya , Louro Sonia R. W. , Pascutti Pedro G. , Anteneodo Celia 
Published: May 2010

AbstractExplicit solvent molecular dynamics simulations of meso‐tetra[4‐sulfonatophenyl] porphyrin (TPPS4−) in water were performed. The relation solute–solvent was examined through the radial distribution function g(r) of water molecules around different groups of the solute. The outcomes of the simulations show that, despite the presence of charged side groups in the particular case of TTPS4−, it displays a global hydrophobic character. Moreover, the hydropathic pattern of the different groups of the solute (central ring and side chains) is also characterized. Additionally, we show that this heterogeneous hydropathicity profile remains basically unaltered by complexing TPPS4− with Fe2+. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Determining the diffusion coefficient of Ni in Cu from a Ni/Cu thin film using linear heating, scanning Auger microscopy and a numerical solution of Fick's second law
Authors: Joubert H. D. , Terblans J. J. , Swart H. C. 
Published: May 2010

AbstractIn previous studies, linear temperature ramping was used to determine diffusion coefficients from bulk‐to‐surface segregation experiments of a low concentration solute. Thin film diffusion studies usually employ a classical heating regime, where a sample's annealing time is taken as the time between insertion and removal from a furnace. The aforementioned study type assumes that the time it takes to heat up a sample after insertion is instantaneous, while the sample cools down instantaneously after removal from the furnace. This assumption is incorrect, as it does not compensate for the various mechanisms that govern heat transfer. In order to eliminate the uncertainty, a linear ramping regime is used and samples were annealed inside an ultra high vacuum (UHV) environment with a programmed linear heating scheme. After each anneal, a depth profile was obtained by simultaneously bombarding the sample with Ar+ ions and monitoring the exposed surface with an electron beam which excites Auger electrons, among others. The depth profiles were normalised and the time scale converted to depth. In order to compare the diffusion profiles obtained from classical annealing studies to the linearly ramped studies, the diffusion coefficient obtained for a classical study of Ni diffusing in Cu was inserted into a numerical solution of Fick's second law, modified to include linear temperature ramping. A diffusion coefficient was also obtained from linearly ramped samples. Comparison of the diffusion profiles calculated with the diffusion coefficients obtained from classical heating and linear heating showed a large discrepancy between the profiles. Copyright © 2010 John Wiley & Sons, Ltd.
Focused ion beam implantation of Ga in InP studied by SIMS and dynamic computer simulations
Authors: Gnaser Hubert 
Published: May 2010

AbstractFocused ion beam implantation of 30 keV Ga+ ions in single‐crystalline InP was investigated by SIMS, using Cs+ primary ions for sputtering. Nine different implantation fluences ranging from 1 × 1013 to 1 × 1017 Ga+ ions/cm2 were used, with implanted areas of 50 × 50 µm2. The Ga concentration distributions of these implants were determined by SIMS depth profiling. Such 30 keV Ga implantations were also simulated by a dynamic Monte Carlo simulation code that takes into account the gradual change of the near‐surface composition due to the Ga incorporation. In both approaches, an essentially linear increase of the Ga content with fluence is found up to ∼1 × 1016 cm−2; for higher fluences, the Ga peak concentration approaches a saturation level which is reached at about (0.5–1) × 1017 cm−2 and amounts to ∼10%. The measured and simulated concentrations of the Ga distributions are in good agreement. The most probable range of the Ga+ ions in InP obtained from the SIMS experiments is ∼23 nm and matches closely with the value from the simulations. Copyright © 2010 John Wiley & Sons, Ltd.
Characterization and quantification of biological micropatterns using cluster SIMS
Authors: Chen Li‐Jung , Shah Sunny S. , Verkhoturov Stanislav V. , Revzin Alexander , Schweikert Emile A. 
Published: May 2010

AbstractMicropatterning is used widely in biosensor development, tissue engineering and basic biology. Creation of biological micropatterns typically involves multiple sequential steps which may lead to cross‐contamination and contribute to suboptimal performance of the surface. Therefore, there is a need to develop novel strategies for characterizing location‐specific chemical composition of biological micropatterns. In this paper, C60+ time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) operating in the event‐by‐event bombardment/detection mode was used for spatially resolved chemical analysis of micropatterned indium tin oxide (ITO) surfaces. Fabrication of the micropatterns involved multiple steps including self‐assembly of poly(ethylene glycol)‐silane (PEG‐silane), patterning of photoresist, treatment with oxygen plasma and adsorption of collagen (I). The ITO surfaces were analyzed with 26‐keV C60+ SIMS run in the event‐by‐event bombardment/detection mode at different steps of the modification process. We were able to evaluate the extent of cross‐contamination between different steps and quantify coverage of the immobilized species. The methodology described here provides a novel means for characterizing the composition of biological micropatterns in a quantitative and spatially resolved manner. Copyright © 2010 John Wiley & Sons, Ltd.
Real‐time localization of single C60 impacts with correlated secondary ion detection
Authors: Eller M. J. , Verkhoturov S. V. , Della‐Negra S. , Rickman R. D. , Schweikert E. A. 
Published: May 2010

AbstractWe assembled hardware and software for the synchronized detection of electrons and ions emitted under the impacts of the individual C60+ and C602+ ions. A projectile impact is localized via the ejected electron(s) with an emission electron microscope (EEM). The (x,y) coordinates of each impact combined with the corresponding record of detected secondary ions (Sis), allow the construction of mass‐selected surface maps.The setup comprises a custom‐built ToF‐SIMS with a C601, 2+ source, an EEM with an electron imaging detector consisting of dual microchannel plates (MCPs), phosphor screen and a 1.3 megapixel CMOS camera. The electron pulse on the aluminized phosphor screen triggers the camera resulting in a frame with the electron image. It also triggers the ToF electronics resulting in a suite of SI time records corresponding to each individual impact event. The data processing and management are handled by custom software including combination of the positional and the mass spectrometric information from each impact.The present study demonstrates the feasibility of mapping a surface by localizing the SI emission from single C602+ impacts. A spatial resolution of 1.3 µm has been obtained. Interestingly, maps of coemitted SIs from a given localization display chemically resolved information from an emission area of ∼102 nm2. Copyright © 2010 John Wiley & Sons, Ltd.
Influence of the polar angle of incidence on secondary ion formation in self‐sputtering of silver
Authors: Weidtmann B. , Hanke S. , Duvenbeck A. , Wucher A. 
Published: May 2010

AbstractThe influence of the projectile impact angle on secondary ion formation was studied using a computer simulation model applied to the bombardment of an amorphous silver crystal by 5‐keV Ag atoms. The model employs a molecular dynamics (MD) scheme for the description of particle dynamics within the atomic collision cascade. The electronic degree of freedom is treated within the framework of a free electron gas model incorporating kinetic excitation by electronic friction and electron promotion. Transport of the excitation energy away from the spot of generation is treated by a diffusive approach. In combination with a rate equation model for electronic charge transfer an individual ionization probability α+ is assigned to each sputtered particle. The results reveal that the average ionization probability of sputtered atoms increases upon the transition from normal to oblique incidence. The dependence of α+ on the emission velocity of ejected atoms is traced back to the temporal structure of the excitation profile induced after projectile impact. Copyright © 2010 John Wiley & Sons, Ltd.
Depth profiling analysis of barrier‐type anodic aluminium oxide films formed on substrates of controlled roughness
Authors: Trigoulet N. , Tuccitto N. , Delfanti I. , Licciardello A. , Molchan I. S. , Skeldon P. , Thompson G. E. , Tempez A. , Chapon P. 
Published: May 2010

AbstractThe depth resolutions achieved by time‐of‐flight secondary ion mass spectrometry (TOF‐SIMS) and glow discharge optical emission spectroscopy (GD‐OES) are comparable for the analysis of relatively flat specimens. However, the precision of sputtering‐induced depth profiling techniques has been shown to be dramatically influenced by the initial roughness of specimen surface. The effect of the specimen roughness on the depth resolution achieved by both techniques has been examined here using textured aluminium substrates supporting anodic oxide films. As a result of dissimilarities in the sputtering processes, TOF‐SIMS and GD‐OES show significantly different elemental depth profiles for electrolyte‐derived species incorporated into anodic oxide films formed on superpure aluminium substrates of controlled texture. Copyright © 2010 John Wiley & Sons, Ltd.
Molecular dynamics study of metal‐organic samples bombarded by kiloelectronvolt projectiles
Authors: Restrepo Oscar A. , Delcorte Arnaud 
Published: May 2010

AbstractIn recent experiments involving metal‐assisted secondary ion mass spectrometry (MetA‐SIMS), either an increase or a decrease of the sputtered organic ion yield was demonstrated depending whether the incoming projectile was atomic (Ga, In) or polyatomic (Bi3, C60). Theoretically, the electronic and molecular processes governing the yield variation are still poorly understood for metal‐organic surfaces. To unravel the physics of sputtering, molecular dynamics simulations involving metal‐organic samples have been implemented. Two targets mimicking, respectively, a gold/organic vertical interface and a molecular sample covered by gold nanoparticles were designed and bombarded with several projectiles, including Ga and C60. The results emphasize the differences of emission and molecular mechanisms induced by these projectiles and explain some of the effects observed in MetA‐SIMS. Copyright © 2010 John Wiley & Sons, Ltd.
Using C60+ sputtering to improve detection limit of nitrogen in zinc oxide
Authors: Zhu Zihua , Shutthanandan Vaithiyalingam , Nachimuthu Ponnusamy 
Published: May 2010

AbstractC60+ sputtering was firstly used to determine depth profile of nitrogen in zinc oxide materials by time‐of‐flight (ToF) SIMS. Compared to traditional Cs+ sputtering depth profiling, the C60+ sputtering provides increase in signal intensity by a factor of over 200 and improves the detection limit by a factor of about 10. In addition, our XPS results show that sputtering zinc oxide materials by 10 keV C60+ leads to very little carbon deposition at the bottom of the sputter crater. Copyright © 2010 John Wiley & Sons, Ltd.
Dual beam depth profiling of organic materials: Variations of analysis and sputter beam conditions
Authors: Rading D. , Moellers R. , Kollmer F. , Paul W. , Niehuis E. 
Published: May 2010

AbstractThe dual beam mode of depth profiling has been used to investigate the influence of sputter beam energy, angle and sample rotation on the quality of organic depth profiles in a TOF‐SIMS instrument. The sample under investigation was a multilayer sample consisting of Irganox 3114 embedded in a Irganox 1010 matrix provided by NPL. C60 sputter beam energies between 10 and 30 keV, and angles of 45° and 75° were used. The results are discussed with respect to depth resolution, constancy of the sputter rate and quantification possibilities. Copyright © 2010 John Wiley & Sons, Ltd.