bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of oxazoles by silver catalysed oxidative decarboxylation–cyclization of α-oxocarboxylates and isocyanides
Authors: Ma Yiyang , Yan Zhiyuan , Bian Changliang , Li Ke , Zhang Xiaowen , Wang Mengfan , Gao Xinlong , Zhang Heng , Lei Aiwen
Published: May 2015

This work developed a silver catalysed synthesis of oxazoles by the oxidative decarboxylation–cyclization of α-oxocarboxylates and isocyanides.
Regioselective direct oxidative C–H cyanation of quinoline and its derivatives catalyzed by vanadium-containing heteropoly acids
Authors: Yamaguchi Kazuya , Xu Ning , Jin Xiongjie , Suzuki Kosuke , Mizuno Noritaka
Published: May 2015

In the presence of catalytic amounts of vanadium-containing heteropoly acids, oxidative C–H cyanation of quinoline and its derivatives using trimethylsilyl cyanide and molecular oxygen efficiently proceeded, affording the corresponding substituted 4-cyanoquinolines as the major products.
A biomimetic phenol substituent effect on the reaction of a dimethylplatinum(ii) complex with oxygen: proton coupled electron transfer and multiple proton relay
Authors: Moustafa Mohamed E. , Boyle Paul D. , Puddephatt Richard J.
Published: May 2015

A phenol substituent has a dramatic effect on the oxidation of a dimethylplatinum(ii) complex with O2.
Features of styryl dye crystal packings and their influence on [2 + 2] photocycloaddition reaction with single crystal retention
Authors: Kuz'mina Lyudmila G. , Vedernikov Artem I. , Howard Judith A. K. , Alfimov Michael V. , Gromov Sergey P.
Published: May 2015

Only in two of three crystal modifications the initial dye is subjected to the SC–SC [2 + 2]-photocycloaddtion under visible light irradiation.
Computation assisted design of favored composition for ternary Mg–Cu–Y metallic glass formation
Authors: Wang Q. , Li J. H. , Liu B. X.
Published: May 2015

The authors employed the constructed Mg–Cu–Y interatomic potential as the starting base and established a relevant atomistic computation/simulation route to assist the design of favored and even optimized compositions and to elucidate the structural origin of glass forming ability in the Mg–Cu–Y system.
Hybrid QTAIM and electrostatic potential-based quantum topology phase diagrams for water clusters
Authors: Kumar Anmol , Gadre Shridhar R. , Chenxia Xiao , Tianlv Xu , Kirk Steven Robert , Jenkins Samantha
Published: May 2015

The topological diversity of sets of isomers of water clusters (W = H2O)n, 7 ≤ n ≤ 10, is analyzed employing the scalar fields of total electronic charge density ρ(r) and the molecular electrostatic potential (MESP).
Simultaneous ion and neutral evaporation in aqueous nanodrops: experiment, theory, and molecular dynamics simulations
Authors: Higashi Hidenori , Tokumi Takuya , Hogan Christopher J. , Suda Hiroshi , Seto Takafumi , Otani Yoshio
Published: May 2015

Neutral and ion evaporation from aqueous nanodrops is examined experimentally, numerically, and theoretically, demonstrating the validity of analytical models.
Temperature-dependent energy levels and size-independent thermodynamics
Authors: de Miguel Rodrigo
Published: May 2015

We show that, by properly adopting the notion of temperature-dependent energy levels, the standard tools of differential thermodynamics can be used for a consistent thermostatistical description irrespective of system size.
Strong or weak acid, which is more efficient for Beckmann rearrangement reaction over solid acid catalysts?
Authors: Chu Yueying , Ji Peng , Yi Xianfeng , Li Shenhui , Wu Peng , Zheng Anmin , Deng Feng
Published: May 2015

The effects of Brønsted acid strength and pore confinement on the Beckmann rearrangement reaction over solid acid catalysts have been explored.
Dehydration of cellulose to levoglucosenone using polar aprotic solvents
Authors: Cao Fei , Schwartz Thomas J. , McClelland Daniel J. , Krishna Siddarth H. , Dumesic James A. , Huber George W.
Published: May 2015

Herein, we report an approach to produce levoglucosenone (LGO) from cellulose in yields up to 51% under mild reaction conditions (170–230 °C; 5–20 mM H2SO4) using polar, aprotic solvents such as tetrahydrofuran (THF).
Dual protection of hydroxytyrosol, an olive oil polyphenol, against oxidative damage in PC12 cells
Authors: Peng Shoujiao , Zhang Baoxin , Yao Juan , Duan Dongzhu , Fang Jianguo
Published: May 2015

Olive oil polyphenol hydroxytyrosol confers neuroprotection via the direct antioxidation and activation of Nrf2 to elevate endogenous antioxidants.
Effect of cocoa products and flavanols on platelet aggregation in humans: a systematic review
Authors: Peluso Ilaria , Palmery Maura , Serafini Mauro
Published: May 2015

The percentage of healthy subjects with decreased platelet aggregation after bolus consumption of cocoa products is reported.
Efficient chemoenzymatic synthesis of lipo-chitin oligosaccharides as plant growth promoters
Authors: Chambon R. , Despras G. , Brossay A. , Vauzeilles B. , Urban D. , Beau J.-M. , Armand S. , Cottaz S. , Fort S.
Published: May 2015

Lipo-chitin oligosaccharides (LCOs), key molecules in plant-symbiotic microorganism communication, are readily obtainedviachemoenzymatic synthesis from chitin, a renewable abundant biopolymer.
Tailoring three-dimensional architectures by rolled-up nanotechnology for mimicking microvasculatures
Authors: Arayanarakool Rerngchai , Meyer Anne K. , Helbig Linda , Sanchez Samuel , Schmidt Oliver G.
Published: May 2015

This paper demonstrates the fabrication and employment of porous tubular microstructures as cell scaffolds to mimic microvasculature with tunable dimensions and biodegradability of scaffolds.
PredcircRNA: computational classification of circular RNA from other long non-coding RNA using hybrid features
Authors: Pan Xiaoyong , Xiong Kai
Published: May 2015

PredcircRNA presents computational classification of circularRNA from other lncRNA using hybrid features based on multiple kernel learning.
Probing the energy levels in hole-doped molecular semiconductors
Authors: Winkler Stefanie , Amsalem Patrick , Frisch Johannes , Oehzelt Martin , Heimel Georg , Koch Norbert
Published: May 2015

The widely established picture of polarons in molecular semiconductors is revised highlighting the role of on-site Coulomb repulsion.
Diverse reactivity of nitrones towards electron deficient acetylenes
Authors: Radhamani Sandhya , Natarajan Rakesh , Unnikrishnan Peruparampil A. , Prathapan Sreedharan , Rappai John P.
Published: May 2015

Herein, we report indirect evidence for the non-concerted nature of 1,3-dipolar addition reaction between N-arylnitrones and electron deficient acetylenes.
Dextran-coated superparamagnetic nanoparticles as potential cancer drug carriers in vivo
Authors: Peng Mingli , Li Houli , Luo Zhiyi , Kong Jian , Wan Yinsheng , Zheng Lemin , Zhang Qinlu , Niu Hongxin , Vermorken Alphons , Van de Ven Wim , Chen Chao , Zhang Xikun , Li Fuqiang , Guo Lili , Cui Yali
Published: May 2015

Dextran-coated SPIONs (DSPIONs) are synthesized and used as drug magnetic carriers to form conjugates of Dox–DSPIONs. The cytotoxicity, intracellular uptake behavior and anti-tumor activity of the conjugates are investigated.
Tailored gold nanostructure arrays as catalysts for oxygen reduction in alkaline media and a single molecule SERS platform
Authors: Nogala Wojciech , Kannan Palanisamy , Gawinkowski Sylwester , Jönsson-Niedziolka Martin , Kominiak Magdalena , Waluk Jacek , Opallo Marcin
Published: May 2015

Tunable size and shape gold nanostructures prepared by localized electrorefining from raw polycrystalline metal as a catalyst for alkaline fuel cell cathodes and SERS support with a 1 × 1010 enhancement factor.
Plasma-assisted synthesis and pressure-induced structural transition of single-crystalline SnSe nanosheets
Authors: Jian Zhang Jian Zhang , Zhu Hongyang , Wu Xiaoxin , Cui Hang , Li Dongmei , Jiang Junru , Gao Chunxiao , Wang Qiushi , Cui Qiliang
Published: May 2015

A novel, efficient and simple method for synthesizing SnSe nanosheets, and their pressure-induced structural transition behaviours have been investigated.
Quantitative analysis of the size effect of room temperature nanoimprinted P3HT nanopillar arrays on the photovoltaic performance
Authors: Ding Guangzhu , Li Chao , Li Xiaohui , Wu Yangjiang , Liu Jieping , Li Yaowen , Hu Zhijun , Li Yongfang
Published: May 2015

We develop a solvent-assisted room temperature nanoimprint lithography (SART-NIL) technique to fabricate an ideal active layer consisting of poly(3-hexylthiophene) nanopillar arrays surrounded by [6,6]-phenyl-C61-butyric acid methyl ester.
Morphology-dependent photocatalytic activity of octahedral anatase particles prepared by ultrasonication–hydrothermal reaction of titanates
Authors: Wei Zhishun , Kowalska Ewa , Verrett Jonathan , Colbeau-Justin Christophe , Remita Hynd , Ohtani Bunsho
Published: May 2015

The morphology of octahedral anatase particles (OAPs) governs their photocatalytic activity due to the possibly higher density of shallow electron traps in OAPs leading to higher mobility of electrons.
Building up strain in colloidal metal nanoparticle catalysts
Authors: Sneed Brian T. , Young Allison P. , Tsung Chia-Kuang
Published: May 2015

The focus on surface lattice strain in nanostructures as a fundamental research topic has gained momentum in recent years as scientists investigated its significant impact on the surface electronic structure and catalytic properties of nanomaterials.
Locked nucleic acid (LNA) induced effect on the hybridization and fluorescence properties of oligodeoxyribonucleotides modified with nucleobase-functionalized DNA monomers
Authors: Kaura Mamta , Hrdlicka Patrick J.
Published: May 2015

Mixmer oligonucleotides modified with LNA and C5-pyrene-functionalized DNA monomers are shown to display interesting fluorescence properties for the discrimination of single nucleotide polymorphisms (SNPs).
Polymer brush functionalized SiO2 nanoparticle based Nafion nanocomposites: a novel avenue to low-humidity proton conducting membranes
Authors: Farrukh Aleeza , Ashraf Fatima , Kaltbeitzel Anke , Ling Xiao , Wagner Manfred , Duran Hatice , Ghaffar Abdul , ur Rehman Habib , Parekh Sapun H. , Domke Katrin F. , Yameen Basit
Published: May 2015

Polymer brush grafted SiO2 NPs provide Nafion nanocomposite membranes with superior proton conductivities at ambient and moderately high temperatures over the entire range of relative humidity.
Differential pulse stripping voltammetric determination of the antipsychotic medication olanzapine at a magnetic nano-composite with a core/shell structure
Authors: Arvand Majid , Orangpour Setareh , Ghodsi Navid
Published: May 2015

Fe3O4@Ag core/shell MNPs were used for modification of carbon paste electrode and the modified electrode was utilized for electrochemical determination of olanzapine.
Synthesis and characterization of hydroxypropyl methylcellulose-g-poly(acrylamide)/LAPONITE® RD nanocomposites as novel magnetic- and pH-sensitive carriers for controlled drug release
Authors: Mahdavinia Gholam Reza , Ettehadi Sanaz , Amini Mojtaba , Sabzi Mohammad
Published: May 2015

pH-responsive magnetic nanocomposite hydrogels based on hydroxypropyl methylcellulose-g-poly(acrylamide)/LAPONITE® RD (HPMC-g-PAALap) were developed.
Ceramic anion-exchange membranes based on microporous supports infiltrated with hydrated zirconium dioxide
Authors: Martí-Calatayud M. C. , García-Gabaldón M. , Pérez-Herranz V. , Sales S. , Mestre S.
Published: May 2015

Anion-exchange membranes were produced by infiltrating microporous ceramic supports with particles of hydrated ZrO2. These membranes can be applied to the electrodialytic treatment of harsh industrial effluents.
Electrochemical study of nanoporous gold revealing anti-biofouling properties
Authors: Saraf Shashank , Neal Craig J. , Park Sanghoon , Das Soumen , Barkam Swetha , Cho Hyoung Jin , Seal Sudipta
Published: May 2015

Schematic shows the morphology of the adsorbed BSA layer on nanoporous gold. Initial response of the electrode from biofouling resulted in faradaic current decay followed by its regeneration due to slow diffusion of analytes through the fouled layer.
Oxidation of thiols to disulfides by dioxygen catalyzed by a bioinspired organocatalyst
Authors: Bagi Nárcisz , Kaizer József , Speier Gábor
Published: May 2015

2,3-Dihydro-2,2,2-triphenylphenanthro[9,10-d]-1,3,2-λ5-oxazaphosphole serves as good catalyst for the oxidation of thiophenol, cysteine and glutathione to their disulfides by molecular oxygen.
Link spacer controlled supramolecular chirality of perylene bisimide-carbohydrate conjugate
Authors: Wang Ke-Rang , Han Dan , Cao Guo-Jing , Li Xiao-Liu
Published: May 2015

Controllable supramolecular chirality based on the self-assembly of the perylene bisimide-carbohydrate conjugates was achieved, exhibiting right-handed chirality with triazole as linker and left-handed chirality with the amide bond as linker.
Image-guided combination chemotherapy and photodynamic therapy using a mitochondria-targeted molecular probe with aggregation-induced emission characteristics
Authors: Zhang Chong-Jing , Hu Qinglian , Feng Guangxue , Zhang Ruoyu , Yuan Youyong , Lu Xianmao , Liu Bin
Published: May 2015

Mitochondria-targeted AIE photosensitizers show multifunctions of targeted and image-guided combination chemotherapy and photodynamic therapy.
Copper-catalyzed diamination of unactivated alkenes with hydroxylamines
Authors: Shen Kun , Wang Qiu
Published: May 2015

A copper-catalyzed regio- and stereoselective diamination of unactivated alkenes has been developed with O-acylhydroxylamines as electrophilic nitrogen sources and oxidants.
Mechanism of the cooperative Si–H bond activation at Ru–S bonds
Authors: Stahl Timo , Hrobárik Peter , Königs C. David F. , Ohki Yasuhiro , Tatsumi Kazuyuki , Kemper Sebastian , Kaupp Martin , Klare Hendrik F. T. , Oestreich Martin
Published: May 2015

The heterolytic splitting of hydrosilanes by ruthenium(ii) thiolates is illuminated by a combined spectroscopic, crystallographic, and computational analysis.
A structural remedy toward bright dipolar fluorophores in aqueous media
Authors: Singha Subhankar , Kim Dokyoung , Roy Basab , Sambasivan Sunderraman , Moon Hyunsoo , Rao Alla Sreenivasa , Kim Jin Yong , Joo Taiha , Park Jae Woo , Rhee Young Min , Wang Taejun , Kim Ki Hean , Shin Youn Ho , Jung Junyang , Ahn Kyo Han
Published: May 2015

Structural factors governing the poor emission of dipolar dyes in aqueous media are identified, leading to new acedan derivatives with brighter fluorescence and enhanced two-photon properties.
How important are dispersion interactions to the strength of aromatic stacking interactions in solution?
Authors: Hwang Jungwun , Dial Brent E. , Li Ping , Kozik Michael E. , Smith Mark D. , Shimizu Ken D.
Published: May 2015

The similarity of aromatic stacking energies in solution for varying sized surfaces suggests that dispersion interactions are a minor contributor.
Palladium carbene complexes as persistent radicals
Authors: Comanescu C. C. , Vyushkova M. , Iluc V. M.
Published: May 2015

A series of palladium(ii) persistent radical carbene complexes, [PC˙(sp2)P]PdX (X = Cl, Br, I), was synthesized from the nucleophilic carbene [PC(sp2)P]PdPMe3.
W6+ & Br− codoped Li4Ti5O12 anode with super rate performance for Li-ion batteries
Authors: Zhang Qianyu , Lu Huansheng , Zhong Haoxiang , Yan Xiaodan , Ouyang Chuying , Zhang Lingzhi
Published: May 2015

We report a novel Li4Ti5−xWxO12−xBrx (x = 0.025, 0.050 and 0.100) anode material simultaneously doped with W6+ and Br− ions prepared by a simple solid-state reaction in air, aiming to significantly improve electrical conductivity of Li4Ti5O12.
Amyloid-directed assembly of nanostructures and functional devices for bionanoelectronics
Authors: Wang Xinyu , Li Yingfeng , Zhong Chao
Published: May 2015

Amyloid-directed assembly of nanostructures and amyloid-enabled functional devices are highlighted to show the promise of amyloids for future bionanoelectronics.
Assembly of a high-scattering photoelectrode using a hybrid nano-TiO2 paste
Authors: Lin Jia , Zheng Li , Liu Xiaolin , Zhu Shu , Liu Yongsheng , Chen Xianfeng
Published: May 2015

Highly crystallized TiO2 nanotube powders were fabricated and incorporated into TiO2 nanoparticle films to form nanotube–nanoparticle hybrid photoanodes.
Gold-rich R3Au7Sn3: establishing the interdependence between electronic features and physical properties
Authors: Provino Alessia , Steinberg Simon , Smetana Volodymyr , Kulkarni Ruta , Dhar Sudesh K. , Manfrinetti Pietro , Mudring Anja-Verena
Published: May 2015

AR3capped Au@Au6cluster sandwiched between two hexagonal Sn layers.
Facial age estimation based on advanced ordinal ranking
Authors: Zhao Wei , Wang Han
Published: May 2015

Ordinal hyperplane ranking achieves superior performance in facial age estimation. However, further experiments show that this approach suffers from its ideal ranking rule, which sometimes causes unnecessary estimation deviations and degrades performance. Two approaches with new ranking rules are proposed, which minimise accidental deviations of binary classifiers and tactfully combine the accuracy and obtained label in each binary classification substep for the ranking criteria. Moreover, at first the extreme learning machine is introduced into facial age estimation, taking full advantage of its high learning speed and accuracy. Experimental results from public datasets are presented to demonstrate that the proposed algorithms reduce the mean absolute error and improve age estimation performance while reducing runtime significantly.
Criterion for designing adaptive filters based on segregation of grey levels in SAR images
Authors: Sahebi M.R. , Heidarian A.
Published: May 2015

In boundary zones (edges) in synthetic apertue radar (SAR) images, there is no logical (scientific) explanation for employing the kernel average for approximating the backscattering factors in central kernel pixels. Therefore, adaptive filters are used to decrease the speckles in these images. These filters prevent the averaging process in the edges when smoothing the images (noise reduction) in homogeneous areas, thus causing reduction of lucidity in the edges. In most existing adaptive filters, the variation coefficient (coefficient of variation) is used to detect the edges in the images. An alternative factor is introduced to detect the edges in intensity images; by employing this factor, an adaptive filter is presented. The results of evaluating this filter and comparing it with other adaptive filters illustrate that it has excellent competency in speckle reduction, and hence it protects the edges of the images during the filtering process. using various assessment measures (such as signal‐to‐noise ratio and mean absolute error), the obtained results provide evidence that the proposed filtering process outperforms other classical methodologies.
Method for ex‐situ training in memristor‐based neuromorphic circuit using robust weight programming method
Authors: Yakopcic C. , Taha T.M. , McLean M.
Published: May 2015

A feedback‐based weight programming method for a high‐density crossbar without the use of any transistor or diode isolation is presented. A series of reads is applied to the crossbar before each write that is able to determine the resistance of each memristor in the crossbar despite the many parallel resistance paths. This is essential because the variation observed in memristor crossbars makes programming very difficult when using just a single write pulse and no error checking. A neuromorphic circuit is programmed using this method. Results show successful ex‐situ training of a high‐density crossbar with significant area savings when compared with a one transistor one memristor design.
Dynastat frequency divider with DC‐153 GHz range
Authors: Vera L. , Long J.R.
Published: May 2015

A dual‐mode dynamic/static (dynastat) divided‐by‐two combines the range of a static frequency divider (DC‐117 GHz from simulation) and the higher toggle frequency of a dynamic divider (85–153 GHz, simulated) at a low input sensitivity of 0.2 Vpk differential (<−3 dBm into 50 Ω). The measured self‐oscillation frequencies of the prototype are 79 GHz (static) and 129 GHz in dynamic mode. The 8880 μm2 dynastat implemented in 90 nm silicon germanium (SiGe)‐bipolar CMOS consumes 38 mA (static) and 19 mA (in dynamic mode) from a 4.5 V supply.
Swing‐programmable SST transmitter with power‐efficient de‐emphasis
Authors: Tang Liangxiao , Gai Weixin , Liu Jincai
Published: May 2015

A novel 10 Gbit/s source‐series‐terminated (SST) transmitter in 65 nm CMOS technology is presented. Different from the conventional SST transmitter with the swing fixed to the supply voltage, the proposed transmitter, employing modified SST topology with switch‐based shunting legs, achieves tunable swing to provide suitable a output voltage for specific channel loss, resulting in higher power efficiency for the short and medium‐length channel. The proposed de‐emphasis scheme operates with the shunting path connecting the differential output pins instead of the voltage supply and the ground, which is more efficient than the conventional way. Fewer slices for de‐emphasis are needed along with less parasitic capacitance, and thus the power efficiency is improved. A full‐rate delay‐matching pre‐driver is used to avoid a complicated structure. Swing ranges from 50 mV to 1.2 V at a 1.2 V supply. The de‐emphasis could be tuned from 0 to −15.5 dB with power consumption dropping from 15.6 to 13.3 mW at the nominal swing of 1.2 V.
Design of absorptive frequency selective surface with good transmission at high frequency
Authors: Chen Qiang , Chen Liang , Bai Jiajun , Fu Yunqi
Published: May 2015

An absorptive frequency selective surface with a wide absorptive property over the low band and a good transmissive property at high frequency is designed. The transmission of high frequency is realised by putting a choke structure into the element to control the current distribution. Its −10 dB absorption band is from 2.8 to 8.3 GHz and the transmission band is at 9.7 GHz with insertion loss <0.5 dB. Numerical and experimental results are given.
Method of doubling range resolution without increasing bandwidth in FMCW radar
Authors: Li Yake , O'Young Siu
Published: May 2015

The frequency modulated continuous‐wave (FMCW) technique has been used in many radar applications owing to its low requirements on radar hardware. Linear sawtooth sweep (the frequency sweeps in one direction) is one of the simplest waveforms employed by most FMCW radars. By theory and real data it is proved that by simply using the linear triangular sweep (the frequency goes first down and then up), the range resolution can be doubled without increasing the transmitted bandwidth.
Area efficient floating‐point FFT butterfly architectures based on multi‐operand adders
Authors: Kaivani Amir , Ko Seok‐Bum
Published: May 2015

Hardware implementation of the fast Fourier transform (FFT) function consists of multiple consecutive arithmetic operations over complex numbers. Applying floating‐point arithmetic to FFT coprocessors leads to a wider dynamic range and allows the coprocessor to collaborate with general purpose processors via the standard floating‐point arithmetic. This offloads compute‐intensive tasks from the primary processor and overcomes floating‐point concerns such as scaling and overflow/underflow detection. The downside, however, is that floating‐point units are slower than the fixed‐point counterparts. One of the popular ways to improve the speed of floating‐point FFT units is to merge the arithmetic operations inside the butterfly units of a FFT architecture. This leads to a butterfly architecture based on multi‐operand adders. Butterfly units are designed, in two of the most recent works, using three‐operand and four‐operand adders. However, the work reported here by the present authors goes further and a butterfly architecture based on a five‐operand adder is proposed. Simulation results demonstrate that the proposed butterfly architecture is 50% smaller than the fastest previous work with about 17% latency overhead. Compared with the smallest previous work, the proposed design is 47% smaller and 8% faster.
Reducing micro‐Doppler effect in compressed sensing ISAR imaging for aircraft using limited pulses
Authors: Hou Qingkai , Liu Yang , Chen Zengping
Published: May 2015

In compressed sensing (CS)‐based inverse synthetic aperture radar (ISAR) imaging for aircraft, the image of the target can be reconstructed using fewer pulses with random pulse repetition intervals than with the conventional range‐Doppler (RD) method. However, the micro‐Doppler (mD) effect induced by the non‐stationary parts of aircraft still causes defocusing as in RD imaging. A method is proposed to reduce the mD effect in CS ISAR imaging. The CS‐based short‐time Fourier transform is deployed to reconstruct the time‐frequency (TF) spectrogram of echoes. An L‐statistics‐based algorithm is applied to separate the non‐stationary scatterers from a rigid main body in the TF domain. Furthermore, the CS algorithm is used to reconstruct the cross‐range image of the main body after mD separation. Compared with direct CS imaging without mD removal, a better image can be obtained. The results of both simulated and real data processing demonstrate the validity of the proposed method.
Optimal state duration assignment in hidden Markov model‐based text‐to‐speech synthesis system
Authors: Khan Najeeb Ullah , Lee Jung‐Chul
Published: May 2015

In state‐of‐the‐art text‐to‐speech (TTS) systems the state durations for each phoneme are generated so as to maximise the state sequence probability given the constraint that the sum of all state durations should be equal to the phoneme duration. Such maximisation sometimes results in negative state durations when the specified phoneme duration is less than the sum of the means of all the states of the phoneme. Such discrepancy implicitly results in the violation of the equality constraint. This has implications for speech research problems, in which each phoneme duration is specified. One such problem is the use of the TTS synthesis system for singing voice synthesis research. An algorithm for state duration assignment is derived so as to maximise the probability of the state sequence with the constraints that the sum of state durations should be equal to the total duration of the phoneme and all the state durations must be greater than or equal to 1. Experimental results show that the proposed algorithm always produces state durations greater than or equal to 1 while satisfying the equality constraint.
Design of superimposed training sequence for spatially correlated multiple‐input–multiple‐output channels under interference‐limited environments
Authors: B. Mishra Himanshu , Vasudevan K.
Published: May 2015

In this study, the design of a superimposed training (ST) for an interference‐limited spatially correlated multiple‐input–multiple‐output (MIMO) system is addressed and a closed‐form solution for designing the training signal is proposed in a sub‐optimal way. Earlier papers have considered noise limited MIMO systems. The authors also propose random/orthogonal variable spread factor (OVSF) codes as a choice for the ST signal. The mean‐squared error of the channel estimate and symbol error rate performances are obtained through simulation. Considering the power allocation issue between the data and training symbols, a sub‐optimal average training power that maximises the lower bound on the effective signal‐to‐interference ratio is also proposed. Simulation results show that the bit error rate performance of the ST is indistinguishable from the OVSF/random ST sequence.
Gaussian mixture model‐based contrast enhancement
Authors: Abdoli Mohsen , Sarikhani Hossein , Ghanbari Mohammad , Brault Patrice
Published: May 2015

In this study, a method for enhancing low‐contrast images is proposed. This method, called Gaussian mixture model‐based contrast enhancement (GMMCE), brings into play the Gaussian mixture modelling of histograms to model the content of the images. On the basis of the fact that each homogeneous area in natural images has a Gaussian‐shaped histogram, it decomposes the narrow histogram of low‐contrast images into a set of scaled and shifted Gaussians. The individual histograms are then stretched by increasing their variance parameters, and are diffused on the entire histogram by scattering their mean parameters, to build a broad version of the histogram. The number of Gaussians as well as their parameters are optimised to set up a Gaussian mixture modelling with lowest approximation error and highest similarity to the original histogram. Compared with the existing histogram‐based methods, the experimental results show that the quality of GMMCE enhanced pictures are mostly consistent and outperform other benchmark methods. Additionally, the computational complexity analysis shows that GMMCE is a low‐complexity method.
Optimal distribution of the optical intensity within a laser beam for optical wireless communications
Authors: Barcik Peter , Wilfert Otakar , Leitgeb Erich , Hudcova Lucie
Published: May 2015

This study is focused on analysing the optimal distribution of optical intensity within a radiated laser beam at a transmitter plane which is propagated through free space as well as through a turbulent atmosphere. To analyse the propagation of an optical wave through atmospheric turbulence, the simulation, based on the split‐step beam propagation method, was utilised. The aim of this study is to determine the optimal parameters for a flattened Gaussian beam at the transmitter plane. As a result, the scintillation index should be reduced. There are a number of theoretical studies aimed at propagating the flattened beam despite the lack of experimental work in this area. Therefore the techniques for generating the flattened Gaussian beam will also be mentioned.
Constant on time controlled zero voltage switching electronic ballast with power quality improvement
Authors: Shrivastava Ashish , Singh Bhim
Published: May 2015

This study deals with the design, modelling and implementation of unity power factor (UPF) boundary conduction mode (BCM)‐based electronic ballast for a T8, 36 W fluorescent lamp. In low power applications, BCM‐based boost converter is widely used because of the low inductor value, however, because of zero crossover distortion, achieving a total harmonic distortion of <10% is difficult for universal AC mains. In proposed electronic ballast, UPF has been achieved at universal AC mains by using a boost power factor corrected converter operating in BCM with constant on time control. The achieved constant DC‐link voltage is converted into high frequency AC voltage using a quasi‐half bridge series resonant inverter to initiate the discharge and also to drive the fluorescent lamp with constant current. The modelling and simulation of the proposed topology have been performed using sim power system tool‐boxes in MATLAB‐Simulink environment. The switching losses have been reduced by achieving zero voltage switching at an operating switching frequency of 46 kHz. Different evaluated parameters have been found as per the international standard IEC61000‐3‐2 of class C regulations.
Approach for modelling stochastically dependent renewable energy‐based generators using diagonal band copula
Authors: Othman Mahmoud M. , Abdelaziz Almoataz Youssef , Hegazi Yasser G. , El‐Khattam Walid
Published: May 2015

This study presents a novel algorithm for modelling stochastically dependent renewable energy‐based generators. To examine and model the stochastic dependence between renewable energy power outputs and system demand, all different random variables corresponding to wind speeds, solar irradiance and system demand are transformed to a common domain ‘the rank/uniform domain’ by applying the cumulative distribution function transformation. The rank correlation is first used to examine stochastic dependence and then, diagonal band copula is employed for considering the multivariate stochastic dependence. Finally, Monte Carlo method is utilised to accurately obtain the most likelihood values of the wind power, photovoltaic power and system demand. The rationale behind the proposed model is to include the probabilistic model into deterministic planning problems. The proposed algorithm is implemented in MATLAB environment and the results and comparisons show the accuracy of the proposed modelling algorithm.
A Clinical Prediction Rule for Clinical Outcomes in Patients Undergoing Surgery for Degenerative Cervical Myelopathy: Analysis of an International AOSpine Prospective Multicenter Data Set of 743 Subjects
Authors: Fehlings Michael , Tetreault Lindsay , Cote Pierre , Kopjar Branko , Arnold Paul
Published: May 2015

Introduction

Knowledge of important clinical predictors of surgical outcome can provide decision support to surgeons and enable them to appropriately manage their patients' expectations. This study aims to determine the most important global clinical predictors of surgical outcome in patients undergoing surgery for CSM, based on data from two multicenter prospective studies.

Patients and Methods

A total of 743 surgical patients with CSM participated in either the CSM-North America or CSM-International study. The model was developed to distinguish between patients with mild myelopathy postoperatively (mJOA ≥ 16) and those with substantial residual neurological impairment (mJOA < 16). Univariate analyses were performed to evaluate the relationship between outcome and various clinical predictors. Multivariate logistic regression was used to formulate the final prediction model.

Results

Univariate analyses demonstrated that the odds of achieving a score ≥ 16 decreased with the presence of certain symptoms, including impaired gait; the presence of certain signs such as lower limb spasticity; positive smoking status; a higher comorbidity score; more severe preoperative myelopathy; and older age. The final prediction model included age (OR = 0.97, p = 0.0017), duration of symptoms (OR = 0.88, p = 0.049), smoking status (OR = 0.51, p = 0.0018), impairment of gait (OR = 1.94, p = 0.0168), broad-based unstable gait (OR = 1.75, p = 0.0133), baseline severity (OR = 1.23, p < 0.0001), and comorbidity score (OR = 0.84, p = 0.0030).

Conclusion

Patients are more likely to achieve a score ≥ 16 if they are younger, have a shorter duration of symptoms, are less severe preoperatively, do not smoke, and do not have comorbidities or evidence of gait dysfunction.
Which Factors Predict Shoulder Asymmetry in Patients with Lenke Type 1 and 3 Curves following Pedicle Screw Instrumentation?
Authors: Enercan Meric , Kahraman Sinan , Gokcen Bahadir , Sanli Tunay , Ozturk Cagatay , Talu Ufuk , Alanay Ahmet , Hamzaoglu Azmi
Published: May 2015

Introduction

Shoulder asymmetry (SA) has been reported to be a frequent (39%) problem after fusion of the main thoracic (MT) curve in patients with nonstructural proximal thoracic (PT) curves (Lenke Type 1 and 3). The purpose of this study was to analyze factors related to shoulder asymmetry and efficacy of traction X-ray under general anesthesia (TrUGA) in predicting postoperative shoulder asymmetry.

Material and Methods

A total of 137 (128 female patients, 9 male patients) consecutive patients (average age: 14.2 [11–17]) with Lenke Type 1 and Type 3 curves and preoperative right shoulder elevation (RSE) with (-) T1 tilt were included in this study. Radiographic analysis included preoperative, postoperative, and follow-up AP standing, supine bending, and TrUGA. Magnitudes of curves, T1 tilt, clavicle angle, shoulder height, first rib angle (FRA), and second rib angles (SRA) were measured as shoulder asymmetry parameters. Left or right shoulder elevation > 1 cm is accepted as shoulder imbalance. SRS-22r and shoulder balance questionnaires were also analyzed at follow-up.

Results

Mean age was 13.96 years (11–17) and average follow-up was 5.21 years (2–12). A total of 107 patients had UIV at T2, 17 patients had UIV at T3, and 13 had UIV at T4. Average correction rates were 69.12% for PT curve, 82.4% for MT curve, and 73.5% for TL/L curve. Postoperatively, 101 patients (73%) had balanced shoulders. A total of 17 patients (12.4%) had LSE and 20 patients (14.6%) had RSE postoperatively. Incidence of LSE was 8.4% (9 patients) for UIV at T2, 29.4% (5 patients) for UIV at T3, and 23.1% (3 patients) UIV at T4. Higher percentage of MT correction was correlated with LSE ( p = 0.043). Shoulder height, clavicula angle, T1 tilt, FRA, and SRA were correlated in TrUGA and at follow-up. Preoperatively, 83% of the patients and at final follow-up 7.8% patients thought they had shoulder asymmetry. Av SRS-22r score was 4.32 (2, 96–5) and was similar in patients who had shoulder asymmetry (4, 36) versus no asymmetry (4, 29).

Conclusion

Risk factors for shoulder asymmetry in patients with nonstructural PT curves are higher correction percentage of MT and extension of instrumentation up to T3 at PT curve. Extension of fusion up to T2 did not always prevent shoulder asymmetry in patients with nonstructural PT curves. Shoulder asymmetry parameters in TrUGA are helpful in predicting postoperative shoulder asymmetry. HRQL scores are similar in patients with SA versus no SA.
International Classification and Function used in a Rehabilitation Program of Low Back Pain Patients
Authors: Schiottz-Christensen Berit
Published: May 2015

Introduction

ICF is developed as a generic system for classification of function. The ICF framework is often used to describe functional capacity of the low back patient (LBP) referred for rehabilitation but the score describing the level of capacity for the individual patient is not used in daily practice. The purpose of the presented study was to implement and validate the core set for LBP used as a framework for reporting information and to evaluate whether information reported in self-administered questionnaires (PRMOs) can be used to fill in parts of the ICF.

Patients and Methods

LBP referred to the University Hospital, Aarhus, Denmark, for further diagnostic procedures were included in the cohort. Overall, 80 patients were described according to the framework of ICF and scored according to the LBP brief core set.1 Of the whole group, 28 (35%) were referred to a rehabilitation center. At inclusion and at the rehabilitation center, the team treating the patient did the ICF scoring at inclusion and at 4 weeks' follow-up. In addition, the patients filled in questionnaires; Roland Morris and SF-36. The correlation between the registration in the context of ICF at one side and RM/SF-36 at the other was estimated to validate whether a self-administered questionnaire is as valid to describe functional capacity as an interview by the treating physician.

Results

The functional capacity evaluated by the treating team at first gradient for each of 35 domains in ICF correlated with information obtained from the self-administered questionnaires RM and SF-36. Valid information can be translated from RM and SF-36 and the time used to complete the ICF form can be reduced. A dynamic model describing the functional capacity of the individual patient in the terms of ICF filled in by self-administered questionnaires will be demonstrated and the need of supplementary information obtained by interview will be highlighted.

Conclusion

ICF can be used as a framework for information used in a rehabilitation program. The corset has to be defined in detail, as well as the approach to the scoring system, before the information given is reliable as well as clinical important in any clinical setting. PROMs can be used to fill in part of the ICF core set. A dynamic database is a valuable tool facilitating the reporting process. Reference Stucki G, Ewert T, Cieza A. Value and application of the ICF in rehabilitation medicine. Disabil Rehabil 2002;24(17):932–938
Association of Lumbar Spondylolisthesis with Low Back Pain and Symptomatic Lumbar Spinal Stenosis in a Population-Based Cohort: The Wakayama Spine Study
Authors: Ishimoto Yuyu
Published: May 2015

Introduction

Despite the high number of surgeries performed for spondylolisthesis, the basic epidemiology of lumbar spondylolisthesis in the general population is not well known. The aim of this study was to clarify the association of lumbar spondylolisthesis with symptomatic lumbar spinal stenosis (LSS) in a population-based cohort study with participants representing the general Japanese population.

Patients and Methods

This cross-sectional study included 938 participants (308 men, 630 women; mean age, 67.3 years; range, 40–93 years). Lumbar radiographs were obtained for all the participants, with lumbar spondylolisthesis classified as a slip of more than 5% on the lateral view. The diagnosis for symptomatic LSS required the presence of both leg symptoms and radiographic lumbar spinal stenosis on magnetic resonance imaging. The presence of symptomatic LSS was compared between participants with and those without lumbar spondylolisthesis using statistical analysis. Furthermore, we clarified the association between the amount of slippage and the presence of neurogenic claudication.

Results

The prevalence of spondylolisthesis at any level was 15.8% overall, 13.0% in men and 17.1% in women, with no significant difference between genders. The prevalence of symptomatic LSS was 9.0% overall, 9.4% in men, and 8.7% in women. Logistic regression analysis after adjustment for age, gender, and BMI showed that there existed a significant association of spondylolisthesis with symptomatic LSS overall. (OR: 2.07, 95% CI: 1.20–3.44). While, among participants with L4 anterior spondylolisthesis, the mean percentage slip in those with neurogenic claudication was 14 ± 1.2% and those without was 14 ± 0.5%, with no significant difference.

Conclusion

This population-based cohort study revealed that there was a significant association of spondylolisthesis with neurogenic claudication, although the amount of slippage was not related to the presence of neurogenic claudication.
Economic Evaluation of Intraoperative Cone Beam CT-Based Navigation for the Placement of Spinal Pedicle Screws: A Patient Level Cost Effectiveness Analysis
Authors: Dea Nicolas , Fisher Charles , Batke Juliet , Street John
Published: May 2015

Introduction

Pedicle screws are routinely used in contemporary spinal surgery. Screw misplacement is however correlated with potential adverse events. The goal of this study is to perform an economic evaluation looking specifically at the misplaced screws leading to reoperation secondary to neurological deficits or biomechanical concerns.

Material and Methods

A patient-level data cost-effectiveness analysis from the hospital perspective was conducted based on a single center observational study of prospectively collected data to determine the value of a navigation system coupled with intraoperative 3D imaging (O-arm Imaging and the StealthStation S7 Navigation Systems, Medtronic, Louisville, CO) in adult spinal surgery. The data source was a consecutive series of patients treated with the aid of computer-assisted surgery (treatment group) compared with a matched historical cohort of patients treated with conventional methods (control group). The primary effectiveness measure studied was the number of reoperations for misplaced screws.

Results

A total of 5,132 pedicle screws were inserted in 502 patients during the study period; 2,682 screws in 253 patients in the treatment group, and 2,450 screws in 249 patients in the control group. Overall accuracy rates were 95.2% for the treatment group and 86.9% for the control group. Two patients (0.8%) required a revision surgery in the treatment group (both within the same admission) compared with 15 patients (6%) in the control group (nine within the same admission and six within 1 year during a subsequent admission). Costs of the different alternatives were assessed based on the annuitization of capital expenditures method. Using this methodology, an incremental cost effectiveness ratio of $15,961/reoperation avoided was calculated for the computer-assisted surgery group. On the basis of a reoperation cost of $12,618, this new technology becomes cost saving for centers performing more than 254 instrumented spinal procedures per year.

Conclusion

Computer-assisted spinal surgery has the potential to reduce reoperation rates and thus to have serious cost-effectiveness implications. High acquisition and maintenance costs of this technology can be offset by equally high reoperation costs. Our cost-effectiveness analysis showed that for high-volume centers, this technology is economically justified.
Quantitative Magnetic Resonance Imaging Analysis of the Cervical Spine Extensor Muscles: A Pilot Study
Authors: Fortin Maryse , Dobrescu Octavian , Ouellet Jean , Weber Michael
Published: May 2015

Introduction

Variations in cervical muscle cross-sectional area (CSA) and composition, particularly of the multifidus muscle, have been reported in patients with chronic neck pain. However, few studies have reported on the reliability of such muscle measurements and there remains no standard protocol for tissue segmentation. Therefore, the purpose of this pilot study was to provide a detailed muscle measurement protocol and determine the reliability of associated cervical muscle size and composition measurements using an open-source image analysis software (ImageJ).

Material and Methods

Cervical magnetic resonance images of 10 individuals with spinal stenosis were selected from an internal database. Muscle CSA and functional cross-sectional area (FCSA, fat-free area) measurements of the multifidus, semispinalis cervicis, semispinalis capitis, and splenius capitis were acquired bilaterally from axial T2-weighted magnetic resonance image from C2–C3 to C6–C7 levels. All measurements were repeated twice, at least 5 days apart and the assessor was blinded to all earlier measurements.

Results

The reliability for the upper (C2–C3 and C3–C4) and lower cervical levels (C4–C5, C5–C6, and C6–C7) was assessed separately. The intrarater reliability measurements were comparable between muscles and spinal levels. The intraclass correlation coefficient (ICC) for the CSA measurements varied between 0.79 to 0.97 at C2–C4 and 0.75 to 0.91 at C4–C7. The reliability was similar for the FCSA measurements and varied between 0.73 to 0.93 at C2–C4 and 0.78 to 0.90 at C4–C7.

Conclusion

The results of this pilot study suggest that the proposed method to investigate cervical muscle size and composition is reliable, with moderate-to-excellent reliability across cervical muscles and vertebral levels.