bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photoinitiated precipitation polymerization in liquid CO2: Fast formation of crosslinked poly(acrylic acid‐co‐methoxy polyethylene glycol acrylate) microspheres
Authors: Wu Bo , Tan Jianbo , Yang Jianwen , Zeng Zhaohua 
Published: August 2011

AbstractPhotoinitiated precipitation polymerization of acrylic acid (AA) and methoxy polyethylene glycol acrylate (MPEGA) was carried out in liquid carbon dioxide using ethanol as cosolvent and trimethylol propane triacrylate (TMPTA) as crosslinker. Monodisperse crosslinked microspheres were obtained with size polydispersity index as low as 1.027. The particle yield rose sharply after irradiation and reached to 52% at 5 min, then gently increased to 65% at 60 min, suggesting that most of microspheres were produced in the first 5 min of irradiation. The particle number increased incessantly till very late stage of reaction, which could be attributed to the direct generation of stable nuclei from the fast crosslinking polymerization instead of oligomer aggregation. The effect of ethanol content, feeding ratio of monomers and crosslinker concentration on the morphologies, size, and dispersity of microspheres has been investigated. X‐ray photoelectron spectroscopy showed that the microspheres obtained by this procedure were covered with abundant carbon double bonds. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Effects of thiols, lithium chloride, and ethoxylated monomers on the frontal polymerization of a triacrylate
Authors: Viner Veronika , Pojman John A. 
Published: August 2011

AbstractThermal frontal polymerization is a process in which a localized reaction propagates through an unstirred system by the coupling of the thermal diffusion and the Arrhenius kinetics of an exothermic polymerization. With multifunctional acrylates, such as trimethylolpropane triacrylate (TMPTA‐n), front temperatures can reach 250 °C, resulting in smoke from unreacted peroxide. Addition of a thiol lowers the front temperature and the front velocity due the copolymerization between the thiol and the acrylate, with some formulations not sufficiently reactive to sustain frontal polymerization. The effects of molecular weight per thiol and functionality of thiol on front temperature and velocity were studied in the frontal copolymerization of TMPTA‐n/trimethylolpropane ethoxylate triacrylate and different thiols. We also investigated the front temperature and velocity for a system containing triacrylate and dodecyl acrylate. Finally, the effects of lithium chloride in the presence of thiol on the front velocity and front temperature were studied. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Synthesis and self‐assembly of diblock copolymers composed of poly(3‐hexylthiophene) and poly(fluorooctyl methacrylate) segments
Authors: Rashid MD. Harun‐Or , Seo Myungeun , Kim Sang Youl , Gal Yeong‐Soon , Park Jong Myung , Kim Eun Young , Lee Won‐Ki , Lim Kwon Taek 
Published: August 2011

AbstractRegioregular poly(3‐hexylthiophene)‐b‐poly(1H,1H‐dihydro perfluorooctyl methacrylate) (P3HT‐b‐PFOMA) diblock copolymers were synthesized by atom transfer radical polymerization of fluorooctyl methacrylate using bromoester terminated poly(3‐hexylthiophene) macroinitiators in order to investigate their morphological properties. The P3HT macroinitiator was previously prepared by chemical modification of hydroxy terminated P3HT. The block copolymers were well characterized by 1H NMR spectroscopy and gel permeation chromatography. Transmission electron microscopy was used to investigate the nanostructured morphology of the diblock copolymers. The block copolymers are able to undergo microphase separation and self‐assemble into well‐defined and organized nanofibrillar‐like micellar morphology. The development of the morphology of P3HT‐b‐PFOMA block copolymers was investigated after annealing in solvent vapor and also in supercritical CO2. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Electroactuation of solvated triblock copolymer dielectric elastomers: Decoupling the roles of mechanical prestrain and specimen thickness
Authors: Krishnan Arjun S. , Vargantwar Pruthesh H. , Ghosh Tushar K. , Spontak Richard J. 
Published: August 2011

AbstractDielectric elastomers (DEs) constitute a class of electroactive polymers that are becoming increasingly important as lightweight and mechanically robust replacements for conventional transducers and actuators. Because of their inherent cycling resilience, they also show tremendous promise as energy‐harvesting media, as well as smart sensors and microfluidic devices. Recent studies have demonstrated that DEs composed of midblock‐solvated triblock copolymers exhibit attractive electromechanical attributes such as giant electroactuation strains at relatively low electric fields at high conversion efficiency. Moreover, the properties of these readily processable systems are highly composition‐tunable, thereby making them ideal candidates for a detailed study of the coupling between initial specimen thickness and mechanical prestrain, which is frequently used to reduce specimen thickness before actuation to lower the voltage required to achieve electroactuation. Conventional wisdom based on the notion of an ideal DE indicates that electroactuation should only depend on pre‐actuation specimen thickness, but we report results that unequivocally indicate a more detailed material/process description is required. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 49: 1569–1582, 2011
The burden of depression in prostate cancer
Authors: Jayadevappa Ravishankar , Malkowicz S. Bruce , Chhatre Sumedha , Johnson Jerry C. , Gallo Joseph J. 
Published: August 2011

AbstractObjectiveWe sought to analyze the prevalence and incremental burden of depression among elderly with prostate cancer.MethodsWe adopted a retrospective cohort design using the Surveillance, Epidemiology and End Results‐Medicare linked database between 1995 and 2003. Patients with prostate cancer diagnosed between 1995 and 1998 were identified and followed retrospectively for 1 year pre‐diagnosis and up to 8 years post diagnosis. In this cohort of patients with prostate cancer, depression during treatment phase (1 year after diagnosis of prostate cancer) or in the follow‐up phase was identified using the International Classification of Diseases‐Ninth Revision depression‐related codes. Poisson, general linear (log‐link) and Cox regression models were used to determine the association between depression status during treatment and follow‐up phases and outcomes–health resource utilization, cost and mortality.ResultsOf the 50,147 patients newly diagnosed with prostate cancer, 4285 (8.54%) had a diagnosis of depression. A diagnosis of depression during treatment phase was associated with higher odds of emergency room visits (odds ratio (OR) = 4.45, 95% CI = 4.13, 4.80), hospitalizations (OR = 3.22, CI = 3.08, 3.37), outpatient visits (OR = 1.71, CI = 1.67, 1.75) and excess risk of death over the course of the follow‐up interval (hazard ratio = 2.82, CI = 2.60, 3.06). Health care costs associated with depression remained elevated compared with costs for men without depression, over the course of the follow‐up.ConclusionsDepression during the treatment phase was associated with significant health resource utilization, costs and mortality among men with prostate cancer. These findings emphasize the need to effectively identify and treat depression in the setting of prostate cancer. Copyright © 2011 John Wiley & Sons, Ltd.
Crystal structure of N‐domain of FKBP22 from Shewanella sp. SIB1: Dimer dissociation by disruption of Val‐Leu knot
Authors: Budiman Cahyo , Angkawidjaja Clement , Motoike Hideki , Koga Yuichi , Takano Kazufumi , Kanaya Shigenori 
Published: August 2011

AbstractFK506‐binding protein 22 (FKBP22) from the psychrotophic bacterium Shewanella sp. SIB1 (SIB1 FKBP22) is a homodimeric protein with peptidyl prolyl cis‐trans isomerase (PPIase) activity. Each monomer consists of the N‐terminal domain responsible for dimerization and C‐terminal catalytic domain. To reveal interactions at the dimer interface of SIB1 FKBP22, the crystal structure of the N‐domain of SIB1 FKBP22 (SN‐FKBP22, residues 1‐68) was determined at 1.9 Å resolution. SN‐FKBP22 forms a dimer, in which each monomer consists of three helices (α1, α2, and α3N). In the dimer, two monomers have head‐to‐head interactions, in which residues 8–64 of one monomer form tight interface with the corresponding residues of the other. The interface is featured by the presence of a Val‐Leu knot, in which Val37 and Leu41 of one monomer interact with Val41 and Leu37 of the other, respectively. To examine whether SIB1 FKBP22 is dissociated into the monomers by disruption of this knot, the mutant protein V37R/L41R‐FKBP22, in which Val37 and Leu41 of SIB1 FKBP22 are simultaneously replaced by Arg, was constructed and biochemically characterized. This mutant protein was indistinguishable from the SIB1 FKBP22 derivative lacking the N‐domain in oligomeric state, far‐UV CD spectrum, thermal denaturation curve, PPIase activity, and binding ability to a folding intermediate of protein, suggesting that the N‐domain of V37R/L41R‐FKBP22 is disordered. We propose that a Val‐Leu knot at the dimer interface of SIB1 FKBP22 is important for dimerization and dimerization is required for folding of the N‐domain.
Systemic nematicidal activity of fluensulfone against the root‐knot nematode Meloidogyne incognita on pepper
Authors: Oka Yuji , Shuker Shimshon , Tkachi Nadia 
Published: August 2011

AbstractBACKGROUND: Fluensulfone, a new nematicide of the fluoroalkenyl group, has proved to be very effective in controlling root‐knot nematodes, Meloidogyne spp., by soil application. The systemic activity of this compound against M. incognita on peppers via soil drenching and foliar spray was evaluated.RESULTS: Root application of fluensulfone via soil drenching showed slight and no nematode control activity when applied 4 and 10 days, respectively, after inoculation. A single foliar spray of peppers with a fluensulfone solution at 3.0 g L−1 prior to inoculation reduced the galling index by 80% and the number of nematode eggs by 73–82% of controls. The reduction in these parameters by fluensulfone was much higher than that obtained with oxamyl or fenamiphos at the same concentration. This activity was also observed when the plants were sprayed 21 days before inoculation. A series of experiments suggested that foliar spray with fluensulfone prior to inoculation reduces nematode invasion. However, foliar spray after inoculation did not inhibit nematode development inside roots.CONCLUSION: Fluensulfone showed relatively high nematode control activity when sprayed on the foliage before inoculation. Fluensulfone may be used as a foliar application, in addition to soil application, for root‐knot nematode control. Copyright © 2011 Society of Chemical Industry
Developmental studies of transgenic maize expressing Cry1Ab on the African stem borer, Busseola fusca; effects on midgut cellular structure
Authors: George Derick M , Rind F Claire , Bendall Mark W , Taylor Mark A , Gatehouse Angharad MR 
Published: August 2011

AbstractBACKGROUND: Busseola fusca is a major pest of maize in Africa but unfortunately is difficult to control using chemical insecticides. Insect‐resistant transgenic crops may provide an alternative viable strategy to control this pest.RESULTS: Recombinant Cry1Ab (1%) reduced larval weight by 60% over the trial period, while larval weight in the control group increased by 25%; no effects on mortality were observed. Insect survival, developmental rate and pupal and adult weight were significantly reduced (P < 0.05) on maize expressing Cry1Ab (MON810) compared with the non‐transformed parental line. These differences were more pronounced with second‐instar larvae than with third‐instar larvae. Leaf area consumed by Bacillus thuringiensis (Bt)‐fed larvae was significantly lower (0.5 cm2 larva−1 day−1) compared with the area consumed by control‐fed insects (3.3 cm2 larva−1 day−1). EM studies revealed that consumption of Bt maize deleteriously affected gut integrity. Effects were observed in columnar cells of the midgut epithelium, with the cytoplasm becoming highly vacuolated; the microvilli were disorganised, the mitochondria were abnormal and there was an increase in the number of lysosomal bodies. The rough endoplasmic reticulum had also become dilated.CONCLUSION: This study confirms the potential for Bt maize, when used as part of an IPM programme, for control of B. fusca. Copyright © 2011 Society of Chemical Industry
What have the mechanisms of resistance to glyphosate taught us?
Authors: Shaner Dale L , Lindenmeyer Richard Bradley , Ostlie Michael H 
Published: August 2011

AbstractThe intensive use of glyphosate alone to manage weeds has selected populations that are glyphosate resistant. The three mechanisms of glyphosate resistance that have been elucidated are (1) target‐site mutations, (2) gene amplification and (3) altered translocation due to sequestration. What have we learned from the selection of these mechanisms, and how can we apply those lessons to future herbicide‐resistant crops and new mechanisms of action? First, the diversity of glyphosate resistance mechanisms has helped further our understanding of the mechanism of action of glyphosate and advanced our knowledge of plant physiology. Second, the relatively rapid evolution of glyphosate‐resistant weed populations provides further evidence that no herbicide is invulnerable to resistance. Third, as new herbicide‐resistant crops are developed and new mechanisms of action are discovered, the weed science community needs to ensure that we apply the lessons we have learned on resistance management from the experience with glyphosate. Every new weed management system must be evaluated during development for its potential to select for resistance, and stewardship programs should be in place when the new program is introduced. Copyright © 2011 Society of Chemical Industry
The effect of PCBM doping on the electroluminescent performance of organic light‐emitting diodes
Authors: Yan Guang , Zhao Suling , Xu Zheng , Zhang Fujun , Kong Chao , Liu Xiaodong , Gong Wei , Xu Xurong 
Published: August 2011

AbstractIn this paper, the devices with and without electron‐injecting layer (EIL) are fabricated. The effect of [6,6]‐Phenyl C61 butyric acid methyl ester (PCBM) doping in the hole transport layer poly(9‐vinylcarbazole)(PVK) on the electroluminescent performance of organic light‐emitting diodes is investigated by changing the PCBM content from 0 to 3%. A simple and efficient method is presented to improve the hole‐mobility of organic light emitting devices by doping PCBM into PVK which facilitates the hole injection and transport, and leads to a low driving voltage with a high luminance in both series of devices. The higher the PCBM concentration is, the higher the efficiency of the doped devices with EIL over the entire investigated PCBM concentration is. However, in the devices without EIL an appropriate concentration (1%) results in a higher efficiency. The balanced carrier in the doped devices with EIL is better than that in other devices. This leads to the improvement in the luminance and current efficiency.
Luminescence properties of engineered nitrogen vacancy centers in a close surface proximity
Authors: Petráková Vladimíra , Nesládek Miloš , Taylor Andrew , Fendrych František , Cígler Petr , Ledvina Miroslav , Vacík Jiří , Štursa Jan , Kučka Jan 
Published: August 2011

AbstractFluorescent cellular biomarkers play an essential role in biology and medicine for in vitro and in vivo imaging in living cells. Recently, we have demonstrated that photoluminescence (PL) can be driven chemically by changing the occupation of NV− and NV0 states by H‐ or O‐termination. In the presented work we study, how the luminescence of NV centers at controlled depth from the surface changes upon different surface treatment. We compare NV luminescence of hydrogen (H) and oxygen (O) terminated surfaces in single crystal diamond (SCD) containing shallow‐implanted NV centers (3–10 nm) with similarly treated nanodiamond particles (ND) of various size distributions. The H‐termination leads to reduction of NV− related luminescence in both, ND and SCD. The effect is much stronger in ND in comparison with SCD. We mathematically model both situations and discuss parameters influencing the effect, including implantation energy and different contents of nitrogen in the diamond crystal lattice.
Residual strain around grown‐in defects in CVD diamond single crystals: A 2D and 3D Raman imaging study
Authors: Crisci Alexandre , Baillet Francis , Mermoux Michel , Bogdan Ganna , Nesládek Milos , Haenen Ken 
Published: August 2011

AbstractSingle crystal diamond grown by chemical vapor deposition (CVD) sometimes exhibits strain induced birefringence arising from bundles of dislocations lying almost parallel to the [001] growth axis. Some of these specific birefringence patterns consist of four or eight bright petals, depending of the observation conditions. The present study reports results of a Raman imaging investigation of such defects. A specific homoepitaxial film still attached to its substrate, which contained a few of these defects, has been studied. Point by point mapping was used to visualize structural features at certain depths inside the crystals to produce either 2D or 3D tomographic images. These defects were easily detected in the Raman images, with specific line intensity, frequency, and width contrasts. Systematically, dislocations were found to nucleate at the epitaxial interface. In each case, dislocation nucleation was caused by particulate (carbon) contamination. High compressive strain was evidenced in the vicinity of the carbon particles, which was found to decrease in magnitude as the film grew in thickness. Dislocation walls were revealed by the width images. In most cases, 4‐arm patterns lying along 〈110〉 directions were evidenced, but sometimes, more complex features were observed. Finally, polarized Raman measurements gave intensity contrasts that were rather similar to those seen in the birefringence images.
Influence of laser energy on the crystallization of Ge2Sb2Te5 thin film prepared by pulsed laser deposition
Authors: Hu D. Z. , Pan F. M. , Lu X. M. , Zhu J. S. 
Published: August 2011

AbstractFour Ge2Sb2Te5 thin films were prepared by pulsed laser deposition (PLD) at 58, 100, 140, and 190 mJ/pulse laser energy, respectively. The influence of laser energy on the crystallization of Ge2Sb2Te5 was investigated. The result shows that laser energy has evident effect on the crystallization of Ge2Sb2Te5, including crystallization temperature, incubation time, Avrami coefficient, and grain size. The sample prepared at 140 mJ/pulse laser energy has the lowest crystallization temperature, the shortest incubation time, the largest Avrami coefficient, and the maximum mean grain size. The result of X‐ray diffraction indicates that there are impurity‐phase peaks in the pattern of the sample prepared at 190 mJ/pulse laser energy. A possible reason was given for these phenomenons.
Piezoelectric MEMS generator based on the bulk PZT/silicon wafer bonding technique
Authors: Tang Gang , Liu Jing‐quan , Liu He‐sheng , Li Yi‐gui , Yang Chun‐sheng , He Dan‐nong , DzungDao Viet , Tanaka Katsuhiko , Sugiyama Susumu 
Published: August 2011

AbstractA MEMS‐based piezoelectric energy harvester was fabricated by bonding a piezoelectric ceramic Pb (Zr,Ti)O3 (PZT) plate to silicon wafer. The generator structure of a trapezoidal shape composite cantilever beam with nickel metal mass was designed. The novel fabrication techniques to obtain PZT thick film with excellent piezoelectric properties, including a low‐temperature PZT—Si bonding using epoxy resin as the intermediate adhesive layer and thinning of the bulk PZT ceramics by mechanical lapping and polishing method, were carried out. A piezoelectric MEMS power generator array was successfully fabricated and the measurement results for a microgenerator with typical dimension were also presented. The test result shows that this novel technique has great potential to fabricate high‐performance piezoelectric MEMS energy harvester.
Comparison of boron diffusion in silicon during shallow p+/n junction formation by non‐melt excimer and green laser annealing
Authors: Aid Siti Rahmah , Matsumoto Satoru , Fuse Genshu , Sakuragi Susumu 
Published: August 2011

AbstractThe combination of Ge pre‐amorphization implantation, low‐energy boron implantation, and non‐melt laser annealing is a promising method for forming ultrashallow p+/n junctions in silicon. In this study, shallow p+/n junctions were formed by non‐melt annealing implanted samples using a green laser (visible laser). The dopant diffusion, activation, and recrystallization of an amorphous silicon layer were compared with those obtained in our previous study in which non‐melt annealing was performed using a KrF excimer laser (UV laser). The experimental results reveal that only slight diffusion of boron in the tail region occurred in green‐laser‐annealed samples. In contrast, remarkable boron diffusion occurred in KrF‐laser‐annealed samples for very short annealing times. Recrystallization of the amorphous silicon layer was slower in green‐laser‐annealed samples than in KrF‐laser‐annealed samples. We consider the penetration depth and the pulse duration are important factors that may affect boron diffusion.
Thermal annealing behavior of fluorescence of Pr3+‐doped lead tungstate single crystal
Authors: Xiong F. B. , Huang Y. D. , Zhu W. Z. 
Published: August 2011

AbstractThe effects of thermal annealing treatment on the spectroscopic properties of Pr3+‐doped PbWO4 crystals were discussed in detail. The polarized absorption spectra, polarized fluorescence spectra, and fluorescence decay curves of main emission manifolds of the as‐grown and annealed Pr3+‐doped PbWO4 crystals were measured at room temperature and analyzed. Thermal annealing treatment can diminish most defect centers related to oxygen vacancies and thermal stress. The results demonstrate that thermal annealing treatment can exert a distinct influence on the spectroscopic properties of Pr3+: PbWO4 crystals as promising phosphors and laser materials.
Optical properties of Dy3+ ions in La3Ga5SiO14 crystal
Authors: Wang Zengmei , Sun Wei 
Published: August 2011

AbstractThe absorption and fluorescence spectra of Dy3+‐doped La3Ga5SiO14 (LGS) crystals were measured and analyzed according to the Judd–Ofelt theory. When applied, the following spectral parameters have been obtained: phenomenological intensity parameters Ωt, Ω2 = 2.64 × 10−20 cm2, Ω4 = 1.39 × 10−20 cm2 and Ω6 = 0.63 × 10−20 cm2. These intensity parameters were used to predict radiative properties that included electronic line strengths, radiative transition probabilities AJ″,J′, the radiative lifetime τrad, the fluorescence branching ratios βJ″,J′. The value of absorption section σabs(λ), and the integrated emission cross sections σem(λ) were also calculated. The emission transition 4F9/2 → 6H13/2 provides potential applications of LGS:Dy crystal as a laser material.
Transparent indium tin oxide as inkjet‐printed thin film electrodes for organic field‐effect transistors
Authors: Hoffmann Rudolf C. , Dilfer Stefan , Schneider Jörg J. 
Published: August 2011

AbstractIndium tin oxide (ITO) thin films can be manufactured by spincoating or inkjet printing of a solution containing indium and tin oximato precursor complexes. After sintering at 600 °C and annealing in reducing atmosphere, resistivities as low as 2.34 × 10−3 Ω cm were observed, with a transparency of more than 95% in the visible region. The employment of an amorphous hafnia interlayer on top of a silicon dioxide dielectric was found to improve the wetting behaviour significantly. Thus source–drain structures could be obtained by inkjet‐printing and field‐effect transistors were constructed using poly(3‐hexylthiophene) (P3HT) as organic semiconductor. magnified image