bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular Topology Tuning of Bipolar Host Materials Composed of Fluorene‐Bridged Benzimidazole and Carbazole for Highly Efficient Electrophosphorescence
Authors: Mondal Ejabul , Hung Wen‐Yi , Chen Yang‐Huei , Cheng Ming‐Hung , Wong Ken‐Tsung 
Published: June 2013

AbstractTwo new molecules, CzFCBI and CzFNBI, have been tailor‐made to serve as bipolar host materials to realize high‐efficiency electrophosphorescent devices. The molecular design is configured with carbazole as the hole‐transporting block and N‐phenylbenzimidazole as the electron‐transporting block hybridized through the saturated bridge center (C9) and meta‐conjugation site (C3) of fluorene, respectively. With structural topology tuning of the connecting manner between N‐phenylbenzimidazole and the fluorene core, the resulting physical properties can be subtly modulated. Bipolar host CzFCBI with a C connectivity between phenylbenzimidazole and the fluorene bridge exhibited extended π conjugation; therefore, a low triplet energy of 2.52 eV was observed, which is insufficient to confine blue phosphorescence. However, the monochromatic devices indicate that the matched energy‐level alignment allows CzFCBI to outperform its N‐connected counterpart CzFNBI while employing other long‐wavelength‐emitting phosphorescent guests. In contrast, the high triplet energy (2.72 eV) of CzFNBI imparted by the N connectivity ensures its utilization as a universal bipolar host for blue‐to‐red phosphors. With a common device configuration, CzFNBI has been utilized to achieve highly efficient and low‐roll‐off devices with external quantum efficiency as high as 14 % blue, 17.8 % green, 16.6 % yellowish‐green, 19.5 % yellow, and 18.6 % red. In addition, by combining yellowish‐green with a sky‐blue emitter and a red emitter, a CzFNBI‐hosted single‐emitting‐layer all‐phosphor three‐color‐based white electrophosphorescent device was successfully achieved with high efficiencies (18.4 %, 36.3 cd A−1, 28.3 lm W−1) and highly stable chromaticity (CIE x=0.43–0.46 and CIE y=0.43) at an applied voltage of 8 to 12 V, and a high color‐rendering index of 91.6.
Facile Microstructure Control of Mesoporous Co1.29Ni1.71O4 and the Effect of the Microstructure on Lithium‐Storage Performance
Authors: Xiao Ying , Hu Changwen , Cao Minhua 
Published: June 2013

AbstractA simple and efficient pathway has been designed and developed to synthesize mesoporous Co1.29Ni1.71O4 nanostructures without the use of any templates. By adjusting the volume ratio of water to ethanol, the Co1.29Ni1.71O4 microstructure can be facilely controlled, and different nanostructures such as microflowers, nanorods, and nanoparticles were obtained. All three as‐synthesized samples have a mesoporous structure, but with different pore‐size distributions, in which the nanorod sample exhibits the highest capacity, good rate capability, and cycle stability as an anode material in lithium‐ion batteries (LIBs). The possible reason might be that the one‐dimensional structure of the nanorods accounts for their higher conductivity relative to microflowers and nanoparticles, and their high conductivity coupled with their mesoporous structure might contribute to their excellent electrochemical performance.
Presynaptic Ultrastructural Plasticity Along CA3→CA1 Axons During Long‐Term Potentiation in Mature Hippocampus
Authors: Bourne Jennifer N. , Chirillo Michael A. , Harris Kristen M. 
Published: June 2013

ABSTRACTIn area CA1 of the mature hippocampus, synaptogenesis occurs within 30 minutes after the induction of long‐term potentiation (LTP); however, by 2 hours many small dendritic spines are lost, and those remaining have larger synapses. Little is known, however, about associated changes in presynaptic vesicles and axonal boutons. Axons in CA1 stratum radiatum were evaluated with 3D reconstructions from serial section electron microscopy at 30 minutes and 2 hours after induction of LTP by theta‐burst stimulation (TBS). The frequency of axonal boutons with a single postsynaptic partner was decreased by 33% at 2 hours, corresponding perfectly to the 33% loss specifically of small dendritic spines (head diameters <0.45 μm). Docked vesicles were reduced at 30 minutes and then returned to control levels by 2 hours following induction of LTP. By 2 hours there were fewer small synaptic vesicles overall in the presynaptic vesicle pool. Clathrin‐mediated endocytosis was used as a marker of local activity, and axonal boutons containing clathrin‐coated pits showed a more pronounced decrease in presynaptic vesicles at both 30 minutes and 2 hours after induction of LTP relative to control values. Putative transport packets, identified as a cluster of less than 10 axonal vesicles occurring between synaptic boutons, were stable at 30 minutes but markedly reduced by 2 hours after the induction of LTP. APV blocked these effects, suggesting that the loss of axonal boutons and presynaptic vesicles was dependent on N‐methyl‐D‐aspartic acid (NMDA) receptor activation during LTP. These findings show that specific presynaptic ultrastructural changes complement postsynaptic ultrastructural plasticity during LTP. J. Comp. Neurol. 521:3898–3912, 2013. © 2013 Wiley Periodicals, Inc.
Polyethylene‐Glycol‐Doped Polypyrrole Increases the Rate Performance of the Cathode in Lithium–Sulfur Batteries
Authors: Wu Feng , Chen Junzheng , Li Li , Zhao Teng , Liu Zhen , Chen Renjie 
Published: June 2013

AbstractPolypyrrole–polyethylene glycol (PPy/PEG)‐modified sulfur/aligned carbon nanotubes (PPy/PEG–S/A‐CNTs) were synthesized by using an in situ polymerization method. The ratio of PPy to PEG equaled 31.7:1 after polymerization, and the PEG served as a cation dopant in the polymerization and electrochemical reactions. Elemental analysis, FTIR, Raman spectroscopy, XRD, and electrochemical methods were performed to measure the physicochemical properties of the composite. Elemental analysis demonstrated that the sulfur, PPy, PEG, A‐CNT, and chloride content in the synthesized material was 64.6 %, 22.1 %, 0.7 %, 12.1 %, and 0.5 %, respectively. The thickness of the polymer shell was about 15–25 nm, and FTIR confirmed the successful PPy/PEG synthesis. The cathode exhibited a high initial specific capacity of 1355 mAh g−1, and a sulfur usage of 81.1 %. The reversible capacity of 924 mAh g−1 was obtained after 100 cycles, showing a remarkably improved cyclability compared to equivalent systems without PEG doping and without any coatings. PPy/PEG provided an effective electronically conductive network and a stable interface structure for the cathode. Rate performance of the PPy/PEG– S/A‐CNT composite was more than double that of the unmodified S/A‐CNTs. Remarkably, the battery could work at a very high current density of 8 A g−1 and reached an initial capacity of 542 mAh g−1; it also retained a capacity of 480 mAh g−1 after 100 cycles. The addition of PEG as a dopant in the PPy shell contributed to this prominent rate improvement. Lithium ions and electrons were available everywhere on the surfaces of the particles, and thus could greatly improve the electrochemical reaction; PEG is a well‐known solvent for lithium salts and a very good lithium‐ion catcher.
Positive feedback for gain enhancement in sub‐100 nm multi‐GHz CMOS amplifier design
Authors: Pude Mark , Mukund P. R. , Burleson Jeff 
Published: June 2013

AbstractThe use of positive feedback as a solution to intrinsic gain degradation in scaled CMOS technologies, such as 65 nm and below, is discussed in detail. Criteria for increasing gain while keeping the system stable are derived using a positive feedback amplifier model. These criteria are shown to provide significant gain enhancement in silicon. This work extends the previously reported DC gain analysis to include evaluation of additional effects of positive feedback as well an investigation of the frequency behavior using S‐parameter measurements in silicon. These S‐parameter measurements of fully differential positive feedback amplifiers designed in TSMC's 65 nm technology show gain enhancements of up to 26.7 dB at frequencies up to 8.5 GHz. Copyright © 2013 John Wiley & Sons, Ltd.
Control of Magnetic Field for Sustainment of Ion Production and Uniform Ion Flux to Substrate in Neutral Loop Discharge Plasma
Authors: Yoshida Takuhei , Sakurai Yohei , Sugawara Hirotake , Murayama Akihiro 
Published: June 2013

SummaryWe simulated electron and ion motions in a neutral loop discharge plasma under the control of the foot of the separatrix sweeping over the substrate and the neutral loop moving within a short distance from the RF antenna by a Monte Carlo method. We analyzed the distributions of ion production and ion flux to the substrate. We found that ion production is sensitive to the magnetic field gradient rather than to the electric field strength. Moreover, by superposing the flux distributions weighted by the residence time of the foot of the separatrix on the substrate, we obtained a uniform time‐averaged distribution of the ion flux to the substrate in a radius range of r = 4.0 to 14.0 cm with σ/m = 0.25% (m: mean, σ: standard deviation). © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 185(1): 9–16, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22417
Trust management system in wireless sensor networks: design considerations and research challenges
Authors: Ishmanov Farruh , Malik Aamir Saeed , Kim Sung Won , Begalov Bahodir 
Published: June 2013

AbstractTrust is an important factor in wireless sensor networks (WSNs) in terms of security enhancement and successful collaboration. Trust management (TM) can ensure that all communicating nodes are trustworthy during authentication, authorisation, or key management, which makes traditional security services more robust and reliable. Moreover, by helping to find reliable nodes, TM improves cooperation among nodes, which is vital for improvement of system performance. Trust estimations and management are highly challenging issues because of the unique features and susceptibility of WSNs to different attacks. These factors prevent direct application of schemes suited to other networks and require careful design in a TM system. Hence, our objective is to discuss and present the concept and design factors of TM in WSNs in detail. Moreover, we explore the current state of research as well as open research issues by reviewing proposed trust computation and management schemes in WSNs. Copyright © 2013 John Wiley & Sons, Ltd.
Avoiding damage and achieving cold tolerance in rice plants
Authors: Cruz Renata Pereira da , Sperotto Raul Antonio , Cargnelutti Denise , Adamski Janete Mariza , de FreitasTerra Tatiana , Fett Janette Palma 
Published: June 2013

AbstractRice is a staple food for half of the human population. Unlike other cereals such as wheat and barley, rice plants are susceptible to cold stress, which often results in decreased productivity, especially in regions where theindicasubspecies is cultivated. Low temperatures can have negative impacts on rice plants during germination, vegetative growth, and reproductive stages. Considering the expected higher frequency of extreme temperature events in the near future, cold waves could even increase the negative impacts of low temperatures in rice production. Here, we review the efforts that have been made to achieve cold tolerance in rice through breeding, the major tools used for evaluating cold tolerance in rice plants, the discovery of quantitative trait loci (QTLs) and genes related to this tolerance, and the results obtained so far by genetic transformation of rice plants with potential cold‐tolerance genes. Although much progress has been achieved, joint efforts from breeders and plant biologists could speed up the production of cold‐tolerant rice plants, and some possible approaches are suggested.
Improvement in the traditional processing method and nutritional quality of traditional extruded cassava‐based snack (modified Ajogun)
Authors: Obadina Adewale O. , Oyewole Olusola B. , Williams Oluwasolabomi E. 
Published: June 2013

AbstractThis study was carried out to investigate and improve the traditional processing method and nutritional quality of the traditional cassava snack (Ajogun). Cassava root (Manihot esculenta Crantz L.) of TME 419 variety was processed into mash (40% moisture content). The cassava mash was mixed into different blends to produce fried traditional “Ajogun”, fried and baked extrudates (modified Ajogun) as snacks. These products were analyzed to determine the proximate composition including carbohydrate, fat, protein, fiber, ash, and moisture contents and functional properties such as bulk density. The results obtained for the moisture, fat, protein, and ash contents showed significant difference (P < 0.05) between the control sample and the extrudates. However, there was no significant difference (P > 0.05) in the carbohydrate and fiber contents between the three samples. There was no significant difference (P > 0.05) in the bulk density of the snacks. Also, sensory evaluation was carried out on the cassava‐based snacks using the 9‐point hedonic scale to determine the degree of acceptability. Results obtained showed significant difference (P < 0.05) between the extrudates and control sample in terms of appearance, taste, flavor, color, aroma, texture, and overall acceptability. The highest acceptability level of the product was at 8.04 for the control sample (traditional Ajogun). This study has shown that “Ajogun”, which is a lesser known cassava product, is rich in protein and fat.
Hypoxia inducible factor‐1 alpha plays a pivotal role in hepatic metastasis of pancreatic cancer: an immunohistochemical study
Authors: Matsuo Yoichiro , Ding Qiang , Desaki Ryosuke , Maemura Kosei , Mataki Yuko , Shinchi Hiroyuki , Natsugoe Shoji , Takao Sonshin 
Published: June 2013

AbstractBackgroundHypoxia is an important condition to promote angiogenesis that is essential to tumor progression, including pancreatic ductal adenocarcinoma (PDAC). We evaluated whether the immunohistochemistry for hypoxia inducible factor‐1α (HIF‐1α) was correlated with hepatic metastases in PDAC.MethodsWe examined the expression of HIF‐1α, vascular endothelial growth factor‐A (VEGF‐A), thymidine phosphorylase (TP) and basic fibroblast growth factor (bFGF) in a total of 100 paraffin‐embedded PDAC primary tumors using immunohistochemical staining, and assessed their clinicopathological correlations. We determined microvessel count (MVC) and apoptotic index (AI), and assessed their correlations with hepatic metastases. Student's t‐test, the Mann–Whitney U‐test, and Spearman correlation coefficients were used to validate the model, and regression analysis was used to test the model.ResultsHypoxia inducible factor‐1α expression induced the expression of multiple angiogenic factors, leading to a higher MVC and a lower AI. HIF‐1α expression (P = 0.0087) and angiogenic factors (P = 0.0079) were significantly associated with not only the microvessel status (P = 0.022) but also the high incidence of hepatic metastasis (P = 0.02), resulting in the worse survival of PDAC patients (P < 0.05).ConclusionsHypoxia inducible factor‐1α plays a pivotal role in hepatic metastasis through its association with the expression of angiogenic factors in PDAC patients. These results may contribute future therapeutic strategies to prevent pancreatic cancer metastasis.
Concept to improve the resistance of bearing steels to seawater
Authors: Krasokha N. , Berns H. 
Published: June 2013

AbstractZur Entwicklung von korrosionsbeständigen härtbaren Wälzlagerstählen für die Meerwassertechnik wurden die Gehalte an Mo und Cr gegenüber X65Cr14 erhöht und der C‐Gehalt durch Nutzung des löslichen N‐Gehaltes gesenkt. Die unter Normaldruck zu erschmelzenden Stähle X51CrN(14)14 und X51CrMoN(14)15‐3 sowie der unter einem N2‐Druck von = 4,7 bar zu erschmelzende X33CrMoN(32)15‐3 versprechen eine höhere Beständigkeit gegen Lochkorrosion und eine geringere Gefahr seigerungsbedingter grober eutektischer Karbide ohne erkennbare Nachteile für die Härte und den Restaustenitgehalt. Die Studie hat allein durch thermodynamische Rechnungen und empirische Formeln ohne zeit‐ und kostenaufwendige Experimente zu einer Vorauswahl erfolgsversprechender neuer Stähle geführt.
A novel abrasive blasting process: Abrasive medium classification and CFD simulations
Authors: Özkaya E. , Bayraktar E. , Turek S. , Biermann D. 
Published: June 2013

AbstractThis study concerns the determination of the significant factors for an innovative deburring process: low pressure abrasive water‐jet blasting. The abrasive medium aluminum oxide (Al2O3) is classified according to the individual characteristics of different grain sizes. Then, the particle behavior in the air jet is analyzed with an optical measuring method, Particle Image Velocimetry (PIV); the velocity profile and the particle distribution of the dispersed system are obtained. Computational Fluid Dynamics (CFD) simulations were verified by comparing the experimental and numerical results, and the velocity range for the abrasive particles has been specified.
Improving T2‐weighted imaging at high field through the use of kT‐points
Authors: Eggenschwiler Florent , O'Brien Kieran R. , Gruetter Rolf , Marques José P. 
Published: June 2013

PurposeAt high magnetic field strengths (B0 ≥ 3 T), the shorter radiofrequency wavelength produces an inhomogeneous distribution of the transmit magnetic field. This can lead to variable contrast across the brain which is particularly pronounced in T2‐weighted imaging that requires multiple radiofrequency pulses. To obtain T2‐weighted images with uniform contrast throughout the whole brain at 7 T, short (2–3 ms) 3D tailored radiofrequency pulses (kT‐points) were integrated into a 3D variable flip angle turbo spin echo sequence.MethodsThe excitation and refocusing “hard” pulses of a variable flip angle turbo spin echo sequence were replaced with kT‐point pulses. Spatially resolved extended phase graph simulations and in vivo acquisitions at 7 T, utilizing both single channel and parallel‐transmit systems, were used to test different kT‐point configurations.ResultsSimulations indicated that an extended optimized k‐space trajectory ensured a more homogeneous signal throughout images. In vivo experiments showed that high quality T2‐weighted brain images with uniform signal and contrast were obtained at 7 T by using the proposed methodology.ConclusionThis work demonstrates that T2‐weighted images devoid of artifacts resulting from B1+ inhomogeneity can be obtained at high field through the optimization of extended kT‐point pulses. Magn Reson Med 71:1478–1488, 2014. © 2013 Wiley Periodicals, Inc.
Fast noniterative calibration of an external motion tracking device
Authors: Zahneisen Benjamin , Lovell‐Smith Chris , Herbst Michael , Zaitsev Maxim , Speck Oliver , Armstrong Brian , Ernst Thomas 
Published: June 2013

PurposeProspective motion correction of magnetic resonance (MR) scans commonly uses an external device, such as a camera, to track the pose of the organ of interest. However, in order for external tracking data to be translated into the MR scanner reference frame, the pose of the camera relative to the MR scanner must be known accurately. Here, we describe a fast, accurate, non‐iterative technique to determine the position of an external tracking device de novo relative to the MR reference frame.Theory and MethodsThe method relies on imaging a sparse object that allows simultaneous tracking of arbitrary rigid body transformations in the reference frame of the magnetic resonance imaging (MRI) machine and that of the external tracking device.ResultsLarge motions in the MRI reference frame can be measured using a sparse phantom with an accuracy of 0.2 mm, or approximately 1/10 of the voxel size. By using a dual quaternion algorithm to solve the calibration problem, a good camera calibration can be achieved with fewer than six measurements. Further refinements can be achieved by applying the method iteratively and using motion correction feedback.ConclusionIndependent tracking of a series of movements in two reference frames allows for an analytical solution to the hand‐eye‐calibration problem for various motion tracking setups in MRI. Magn Reson Med 71:1489–1500, 2014. © 2013 Wiley Periodicals, Inc.
Improved steering of the RF field of traveling wave MR with a multimode, coaxial waveguide
Authors: Andreychenko A. , Kroeze H. , Boer V. O. , Lagendijk J. J. W. , Luijten P. R. , van den Berg C. A. T. 
Published: June 2013

PurposeMagnetic resonance imaging of humans at high magnetic field strengths is strongly influenced by the interference of the radiofrequency (RF) electromagnetic field and the body. To minimize this effect, multiple RF sources could be used. A novel setup (called multimode, coaxial waveguide) is proposed that facilitates RF shimming based on the traveling waves.MethodsThe multimode, coaxial waveguide combines the coaxial waveguide, cylindrical waveguide, high dielectric permittivity lining, and eight radial stub antennas. Each antenna excites multiple waveguide modes. Based on modes orthogonality, a method was devised to decompose an excitation pattern of single stub antenna into waveguide modes.ResultsThe number of modes present in the excitation pattern of a single stub antenna increased with the higher effective permittivity of the dielectric lining. Thus, RF shimming performance of the setup was improved. An average homogeneity of 10% was demonstrated for a single slice of each principle plane in the human head at 7 T.ConclusionTraveling wave RF shimming is feasible both in axial and longitudinal directions and is improved with an increased amount of orthogonal waveguide modes. Nevertheless, with the currently available RF amplifiers at 7 T, the performance of the setup is limited to low flip angles. Magn Reson Med 71:1641–1649, 2014. © 2013 Wiley Periodicals, Inc.
A randomized controlled pilot study testing three types of health coaches for obesity treatment: Professional, peer, and mentor
Authors: Leahey Tricia M. , Wing Rena R. 
Published: June 2013

AbstractDespite their popularity, empirical support for health coaches is limited.Objective:This study examined the feasibility and preliminary efficacy of three types of coaching models for obesity treatment.Design and Methods:Participants (N = 44) were randomized to 6 months of reduced intensity group behavioral weight loss (rBWL) plus one of three types of health coaches: (i) Professional (rBWL interventionist), (ii) Peer (group members randomly paired and coached one another), or (iii) Mentor (successful weight loser). Groups met weekly for the first 6 weeks, biweekly for the next 6 weeks, and monthly thereafter, for a total of 12 meetings. During weeks that group did not meet, participants emailed their weight loss information to their coach and received feedback. Coaches were trained on appropriate coaching strategies and feedback delivery.Results:Retention was 95%. Participants emailed their progress to their coach 10.8 ± 1.9 of the 12 weeks that there were no group meetings. Coaches responded with feedback 94% of the time. Percent weight losses at 6 months were 9.6 ± 8.1, 9.1 ± 5.0, and 5.7 ± 5.6 for the Professional, Peer, and Mentor conditions, respectively. More participants in the Professional and Peer conditions lost 10% of their initial body weight (Professional: 56% Peer: 50% and Mentor: 17%), with a statistically significant difference between the Professional and Mentor conditions (P = 0.03).Conclusion:These preliminary data suggest that combining a rBWL program with health coaching may hold significant promise as a cost‐effective obesity treatment paradigm. Larger trials are needed to conclusively determine whether adding coaches improves weight loss outcomes in reduced intensity treatments and to examine which type of coach is most effective.