bluuebunny/crossref_metadata_2025 huggingface dataset:
The Genetics of POAG in Black South Africans: A Candidate Gene Association Study
Authors: Williams Susan E. I. , Carmichael Trevor R. , Allingham R. Rand , Hauser Michael , Ramsay Michele
Published: February 2015

Multiple loci have been associated with either primary open angle glaucoma (POAG) or heritable ocular quantitative traits associated with this condition. This study examined the association of these loci with POAG, with central corneal thickness (CCT), vertical cup-to-disc ratio (VCDR) and with diabetes mellitus in a group of black South Africans (215 POAG cases and 214 controls). The population was homogeneous and distinct from other African and European populations. Single SNPs in the MYOC, COL8A2, COL1A1 and ZNF469 gene regions showed marginal associations with POAG. No association with POAG was identified with tagging SNPs in TMCO1, CAV1/CAV2, CYP1B1, COL1A2, COL5A1, CDKN2B/CDKN2BAS-1, SIX1/SIX6 or the chromosome 2p16 regions and there were no associations with CCT or VCDR. However, SNP rs12522383 in WDR36 was associated with diabetes mellitus (p = 0.00008). This first POAG genetic association study in black South Africans has therefore identified associations that require additional investigation in this and other populations to determine their significance. This highlights the need for larger studies in this population if we are to achieve the goal of facilitating early POAG detection and ultimately preventing irreversible blindness from this condition.
Inhibitors of glutamate release from breast cancer cells; new targets for cancer-induced bone-pain
Authors: Fazzari Jennifer , Lin Hanxin , Murphy Cecilia , Ungard Robert , Singh Gurmit
Published: February 2015

Glutamate is an important signaling molecule in a wide variety of tissues. Aberrant glutamatergic signaling disrupts normal tissue homeostasis and induces several disruptive pathological conditions including pain. Breast cancer cells secrete high levels of glutamate and often metastasize to bone. Exogenous glutamate can disrupt normal bone turnover and may be responsible for cancer-induced bone pain (CIBP). CIBP is a significant co-morbidity that affects quality of life for many advanced-stage breast cancer patients. Current treatment options are commonly accompanied by serious side-effects that negatively impact patient care. Identifying small molecule inhibitors of glutamate release from aggressive breast cancer cells advances a novel, mechanistic approach to targeting CIBP that could advance treatment for several pathological conditions. Using high-throughput screening, we investigated the ability of approximately 30,000 compounds from the Canadian Compound Collection to reduce glutamate release from MDA-MB-231 breast cancer cells. This line is known to secrete high levels of glutamate and has been demonstrated to induce CIBP by this mechanism. Positive chemical hits were based on the potency of each molecule relative to a known pharmacological inhibitor of glutamate release, sulfasalazine. Efficacy was confirmed and drug-like molecules were identified as potent inhibitors of glutamate secretion from MDA-MB-231, MCF-7 and Mat-Ly-Lu cells.
Tuning Interior Nanogaps of Double-shelled Au/Ag Nanoboxes for Surface-Enhanced Raman Scattering
Authors: Zhang Weiqing , Rahmani Mohsen , Niu Wenxin , Ravaine Serge , Hong Minghui , Lu Xianmao
Published: February 2015

Double-shelled Au/Ag hollow nanoboxes with precisely controlled interior nanogaps (1 to 16 nm) were synthesized for gap-tunable surface-enhanced Raman scattering (SERS). The double-shelled nanoboxes were prepared via a two-step galvanic replacement reaction approach using Ag nanocubes as the templates, while 4-aminothiolphenol (4-ATP) as SERS probe molecules were loaded between the two shells. More than 10-fold enhancement of SERS is observed from the double-shelled nanoboxes than Ag nanocubes. In addition, the SERS of the double-shelled nanoboxes increase significantly with the decrease of gap size, consistent with the theoretical prediction that smaller gap size induces larger localized electromagnetic enhancement.
Down-Regulation of Human Enteric Antimicrobial Peptides by NOD2 during Differentiation of the Paneth Cell Lineage
Authors: Tan Gao , Li Run-hua , Li Chen , Wu Fang , Zhao Xin-mei , Ma Jia-yi , Lei Shan , Zhang Wen-di , Zhi Fa-chao
Published: February 2015

Ileal Crohn's disease (CD) arising from the alteration of intestinal homeostasis is characterized by two features, namely a decrease in Paneth cell-produced antimicrobial peptides that play a key role in maintaining this balance and an increase in NOD2, an intracellular sensor. Although mutations in NOD2 are highly correlated with the incidence of CD, the physiological role of NOD2 in intestinal immunity remains elusive. Here, we show that NOD2 can down-regulate the expression of human enteric antimicrobial peptides during differentiation of the Paneth cell lineage. This finding, which links the decrease of human enteric antimicrobial peptides to increased NOD2 in ileal CD patients, provides a new view into the pathogenesis of ileal CD.
Microscopic Receding Contact Line Dynamics on Pillar and Irregular Superhydrophobic Surfaces
Authors: Yeong Yong Han , Milionis Athanasios , Loth Eric , Bayer Ilker S.
Published: February 2015

Receding angles have been shown to have great significance when designing a superhydrophobic surface for applications involving self-cleaning. Although apparent receding angles under dynamic conditions have been well studied, the microscopic receding contact line dynamics are not well understood. Therefore, experiments were performed to measure these dynamics on textured square pillar and irregular superhydrophobic surfaces at micron length scales and at micro-second temporal scales. Results revealed a consistent “slide-snap” motion of the microscopic receding line as compared to the “stick-slip” dynamics reported in previous studies. Interface angles between 40–60° were measured for the pre-snap receding lines on all pillar surfaces. Similar “slide-snap” dynamics were also observed on an irregular nanocomposite surface. However, the sharper features of the surface asperities resulted in a higher pre-snap receding line interface angle (~90°).
Integrin-Linked Kinase links Dynactin-1/Dynactin-2 with cortical Integrin receptors to orient the mitotic spindle relative to the substratum
Authors: Morris Edward James , Assi Kiran , Salh Baljinder , Dedhar Shoukat
Published: February 2015

Cells must divide strictly along a plane to form an epithelial layer parallel to the basal lamina. The axis of cell division is primarily governed by the orientation of the mitotic spindle and spindle misorientation pathways have been implicated in cancer initiation. While β1-Integrin and the Dynein/Dynactin complex are known to be involved, the pathways linking these complexes in positioning mitotic spindles relative to the basal cortex and extracellular matrix remain to be elucidated. Here, we show that Integrin-Linked Kinase (ILK) and α-Parvin regulate mitotic spindle orientation by linking Dynactin-1 and Dynactin-2 subunits of the Dynein/Dynactin complex to Integrin receptors at the basal cortex of mitotic cells. ILK and α-Parvin are required for spindle orientation. ILK interacts with Dynactin-1 and Dynactin-2 and ILK siRNA attenuates Dynactin-2 localization to the basal cortex. Furthermore we show that Dynactin-2 can no longer colocalize or interact with Integrins when ILK is absent, suggesting mechanistically that ILK is acting as a linking protein. Finally we demonstrate that spindle orientation and cell proliferation are disrupted in intestinal epithelial cells in vivo using tissue-specific ILK knockout mice. These data demonstrate that ILK is a linker between Integrin receptors and the Dynactin complex to regulate mitotic spindle orientation.
Photoresponse dynamics in amorphous-LaAlO3/SrTiO3 interfaces
Authors: Di Gennaro Emiliano , Coscia Ubaldo , Ambrosone Giuseppina , Khare Amit , Granozio Fabio Miletto , di Uccio Umberto Scotti
Published: February 2015

The time-resolved photoconductance of amorphous and crystalline LaAlO3/SrTiO3 interfaces, both hosting an interfacial 2-dimensional electron gas, is investigated under irradiation by variable-wavelengths, visible or ultraviolet photons. Unlike bare SrTiO3 single crystals, showing relatively small photoconductance effects, both kinds of interfaces exhibit an intense and highly persistent photoconductance with extraordinarily long characteristic times. The temporal behaviour of the extra photoinduced conductance persisting after light irradiation shows a complex dependence on interface type (whether amorphous or crystalline), sample history and irradiation wavelength. The experimental results indicate that different mechanisms of photoexcitation are responsible for the photoconductance of crystalline and amorphous LaAlO3/SrTiO3 interfaces under visible light. We propose that the response of crystalline samples is mainly due to the promotion of electrons from the valence bands of both SrTiO3 and LaAlO3. This second channel is less relevant in amorphous LaAlO3/SrTiO3, where the higher density of point defects plays instead a major role.
Certified ion implantation fluence by high accuracy RBS
Authors: Colaux Julien L. , Jeynes Chris , Heasman Keith C. , Gwilliam Russell M.
Published: February 2015

1% Implanter Performance: RBS/measured fluence ratio for 16 implants (1015 As cm−2) over 2 years.
Determination of baicalin and ginsenoside Re in Banxia-Xiexin decoction using pharmacokinetics and icELISA analysis in mice. Effects of interaction between prescription herbs on the pharmacokinetics of compounds
Authors: Sun Ye , Qu Huihua , Sai Jiayang , Kong Hui , Zhao Yan , Wang Qingguo
Published: February 2015

Currently, little is known about how the dosage of one component of traditional Chinese medicine (TCM) alters the pharmacokinetic properties of the others in prescriptions.
Enantioseparation characteristics of chiral stationary phases based on the derivatives of cellulose and chitin
Authors: Wang Xiao-Chen , Zhang Juan , Xu Xiao-Qin , Chen Wei , Yang Yong-Gang , Bai Zheng-Wu
Published: February 2015

The chiral stationary phases (CSPs) of cellulose and chitin derivatives show highly chiral resolving capability towards racemates.
Multi-walled carbon nanotubes-agarose gel micro-solid phase extraction for the determination of triazine herbicides in water samples
Authors: Sanagi Mohd Marsin , Muzakkir Mat Jais Mohamad Nazirul , Kamaruzaman Sazlinda , Wan Ibrahim Wan Aini , Baig Umair
Published: February 2015

A new extraction procedure termed multi-walled carbon nanotubes-agarose gel micro-solid phase extraction (MWCNTs-AG-μSPE) combined with GC-MS was used for the determination of triazine herbicides in water samples.
Crystallographic and computational investigation of intermolecular interactions involving organic fluorine with relevance to the hybridization of the carbon atom
Authors: Shukla Rahul , Chopra Deepak
Published: February 2015

C–H⋯F–C interaction on the basis of hybridization of the carbon atom participating in the interaction has been analyzed by performing statistical studies using CSD, evaluating the energetics using PIXEL and performing a topological analysis using AIMALL.
An alternative interpretation of the ultracold methylhydroxycarbene rearrangement mechanism: cooperative effects
Authors: Morais Sara F. de A. , Mundim Kleber C. , Ferreira Daví A. C.
Published: February 2015

Recent studies have reported surprising results related to the rearrangement of carbenes under ultracold conditions, through quantum tunnelling. Here, we demonstrate that a rearrangement of methylhydroxycarbene is possible through cooperative effects.
Low temperature catalytic oxidation of volatile organic compounds: a review
Authors: Huang Haibao , Xu Ying , Feng Qiuyu , Leung Dennis Y. C.
Published: February 2015

Volatile organic compounds (VOCs) are toxic and recognized as one of the major contributors to air pollution.
Coupling of platinated triguanides with platinum-activated nitriles as a novel strategy for generation of dimetallic systems
Authors: Serebryanskaya Tatiyana V. , Novikov Alexander S. , Gushchin Pavel V. , Zolotarev Andrey A. , Gurzhiy Vladislav V. , Kukushkin Vadim Yu.
Published: February 2015

Intermolecular ligand–ligand coupling as a novel approach to the construction of dimetallic systems.
Metallothionein isoforms for selective biosorption and preconcentration of cadmium at ultra-trace levels
Authors: Yang Ting , Ma Lin-Yu , Chen Ming-Li , Wang Jian-Hua
Published: February 2015

Metallothioneins immobilized on spherical SiO2 particles exhibit favorable adsorption behavior toward cadmium, which facilitate selective adsorption of cadmium from complex sample matrices.
Characterization of disulfide bonds by planned digestion and tandem mass spectrometry
Authors: Na Seungjin , Paek Eunok , Choi Jong-Soon , Kim Duwoon , Lee Seung Jae , Kwon Joseph
Published: February 2015

Planned digestion with missed cleavage identified disulfide bonds of RNase A.
A set of robust fluorescent peptide probes for quantification of Cu(ii) binding affinities in the micromolar to femtomolar range
Authors: Young Tessa R. , Wijekoon Chathuri J. K. , Spyrou Benjamin , Donnelly Paul S. , Wedd Anthony G. , Xiao Zhiguang
Published: February 2015

A set of four fluorescent probes were developed and demonstrated to be capable of quantifying Cu(ii) binding affinities in the micromolar to femtomolar range and exploring Cu(ii) binding ligands in peptides and proteins.
Cleavage of the C–C triple bond of ketoalkynes: synthesis of 4(3H)-quinazolinones
Authors: Yang Xifa , Cheng Guolin , Shen Jinhai , Kuai Changsheng , Cui Xiuling
Published: February 2015

A novel strategy to 4(3H)-quinazolinones from ketoalkynes and o-aminobenzamides through C–C triple bond fragmentation and two C–N bond formations under external oxidant and metal free conditions.
Alkyl- and aryl-thioalkylation of olefins with organotrifluoroborates by photoredox catalysis
Authors: Li Yanjie , Miyazawa Kazuki , Koike Takashi , Akita Munetaka
Published: February 2015

A new photocatalytic alkyl- and aryl-thioalkylation of electron-deficient olefins using organotrifluoroborates has been developed.
One-step synthesis of carbon nanodots for sensitive detection of cephalexin
Authors: Wang Kunjie , Guan Feng , Li Hongxia , Li Mingliang , Feng Huixia , Fan Haiyan
Published: February 2015

We present potato based photoluminescent carbon nanodots for detecting cephalexin with a detection limit as low as 0.311 μM.
Carbon dots based turn-on fluorescent probes for oxytetracycline hydrochloride sensing
Authors: An Xuting , Zhuo Shujuan , Zhang Ping , Zhu Changqing
Published: February 2015

A well-designed turn-on sensor has been constructed and used for the assay of oxytetracycline hydrochloride in real milk samples.
Two (3,6)-connected porous metal–organic frameworks based on linear trinuclear [Co3(COO)6] and paddlewheel dinuclear [Cu2(COO)4] SBUs: gas adsorption, photocatalytic behaviour, and magnetic properties
Authors: Zhao Jun , Dong Wen-Wen , Wu Ya-Pan , Wang Ye-Nan , Wang Chao , Li Dong-Sheng , Zhang Qi-Chun
Published: February 2015

Two porous MOFs based on linear [Co3(COO)6] and paddlewheel [Cu2(COO)4] SBUs, showing high visible-light-driven photocatalytic efficiency for the degradation of RhB and high uptake capacities for CO2 and H2.
Ultrathin oxide shell coating of metal nanoparticles using ionic liquid/metal sputtering
Authors: Torimoto Tsukasa , Ohta Yasuhiro , Enokida Kazuki , Sugioka Daisuke , Kameyama Tatsuya , Yamamoto Takahisa , Shibayama Tamaki , Yoshii Kazuki , Tsuda Tetsuya , Kuwabata Susumu
Published: February 2015

The indium sputter deposition into ionic liquids containing noble metal nanoparticles produces core–shell-structured metal@In2O3with high thermal and electrochemical stability.
Dendritic amphiphile mediated porous monolith for eliminating organic micropollutants from water
Authors: Ye Yonglian , Wan Decheng , Du Jiang , Jin Ming , Pu Hongting
Published: February 2015

Few adsorbents with a macroscopic size can combine well with a 3D microscopically well-tailored surface.
A supermolecular building layer approach for gas separation and storage applications: the eea and rtl MOF platforms for CO2 capture and hydrocarbon separation
Authors: Chen Zhijie , Adil Karim , Weseliński Łukasz J. , Belmabkhout Youssef , Eddaoudi Mohamed
Published: February 2015

The supermolecular building layer (SBL) approach allows deliberate construction of tunable MOFs with contracted pore size permitting enhanced gas selectivity.
Facile synthesis of composition-gradient Cd1−xZnxS quantum dots by cation exchange for controlled optical properties
Authors: Choi Dayeon , Pyo Ji-Young , Kim Yeonho , Jang Du-Jeon
Published: February 2015

A facile cation-exchange method has been used to synthesize composition-gradient Cd1−xZnxS quantum dots having systematically controlled optical properties.
A facile and environmentally friendly route to multiferroic nanorods and their size-dependent magnetic properties
Authors: Wu Songping , Lv Yichao , Lu Mingjia , Lin Zhiqun
Published: February 2015

Size-tunable uniform ErMn2O5 nanorods were synthesized via a surfactant-templated hydrothermal route. They exhibited strong size dependent magnetic properties, that is, a critical length of nanorods for magnetization due to the competition between uncompensated spin and surface strain.
Structure-tunable Janus fibers fabricated using spinnerets with varying port angles
Authors: Chen Gaoyun , Xu Ying , Yu Deng-Guang , Zhang Dao-Fang , Chatterton Nicholas P. , White Kenneth N.
Published: February 2015

Janus nanofibers with tunable structures (modulation of width, interface and volume) can be prepared using spinnerets with varying port angles.
A crossed molecular beam and ab initio study on the formation of 5- and 6-methyl-1,4-dihydronaphthalene (C11H12) via the reaction of meta-tolyl (C7H7) with 1,3-butadiene (C4H6)
Authors: Muzangwa Lloyd G. , Yang Tao , Parker Dorian S. N. , Kaiser Ralf. I. , Mebel Alexander M. , Jamal Adeel , Ryazantsev Mikhail , Morokuma Keiji
Published: February 2015

The crossed molecular beam reactions of the meta-tolyl radical with 1,3-butadiene and D6-1,3-butadiene were conducted at collision energies of 48.5 kJ mol−1 and 51.7 kJ mol−1.
Experimental and DFT studies on Sr-doped LaMnO3 catalysts for NOx storage and reduction
Authors: Peng Yue , Si Wenzhe , Li Junhua , Crittenden John , Hao Jiming
Published: February 2015

DFT and experimental studies on LaxSr1−xMnO3 perovskite materials show that a Mn-terminated surface with Sr-doping displays good performance in NSR technology.
Ring-opening polymerization of cyclohexene oxide using aluminum amine–phenolate complexes
Authors: Plommer Hart , Reim Immanuel , Kerton Francesca M.
Published: February 2015

Al(iii) catalysts at concentrations as low as 0.001% ring-open cyclohexene oxide to yield high molecular weight polyether with narrow dispersity.
Cycloaddition reactions of (C6F5)2BN3 with dialkyl acetylenedicarboxylates
Authors: Melen Rebecca L. , Stephan Douglas W.
Published: February 2015

The 1,3-dipolar cycloaddition reactions of the electron deficient boron azide, (C6F5)2BN3 (1) with the electron-poor acetylenes RO2CCCCO2R (R = Me, Et) afforded the new mono- and bis-1,2,3-triazole derivatives 5 and 6.
Effect of the cation size on the framework structures of magnesium tungstate, A4Mg(WO4)3(A = Na, K), R2Mg2(WO4)3(R = Rb, Cs)
Authors: Han Shujuan , Wang Ying , Jing Qun , Wu Hongping , Pan Shilie , Yang Zhihua
Published: February 2015

A series of alkali metal magnesium tungstates, A4Mg(WO4)3(A = Na, K), R2Mg2(WO4)3(R = Rb, Cs), were synthesized from a high temperature solution, and their structures were determined by single-crystal X-ray diffraction.
Detection of trace-level uranium and samarium in glasses by combined laser-induced breakdown spectroscopy and plasma-induced fluorescence spectroscopy
Authors: Liu Lei , Li Shuo , Huang Xi , Lu Yao , Chen Kevin , Pik Raphaël , Jiang Lan , Silvain Jean Francois , Lu Yong Feng
Published: February 2015

Combined analysis of LISB and plasma-induced fluorescence spectroscopy was used for trace-level uranium and samarium detection in glasses.
On-chip surface acoustic wave lysis and ion-exchange nanomembrane detection of exosomal RNA for pancreatic cancer study and diagnosis
Authors: Taller Daniel , Richards Katherine , Slouka Zdenek , Senapati Satyajyoti , Hill Reginald , Go David B. , Chang Hsueh-Chia
Published: February 2015

A novel approach to the analysis of exosomal RNA is presented using SAW exosome lysis and ion-exchange nanomembrane RNA sensing.
Au(i) π-bis(tert-butyldimethylsilyl)acetylene triphenylphosphine complex, an effective pre-catalyst for Au(i)-catalyzed reactions
Authors: Zhu Dapeng , Cao Xin , Yu Biao
Published: February 2015

A [Ph3PAu]+ η2-alkyne π complex is found to be shelf-stable and effective for a range of the Au(i)-catalyzed alkyne π activation reactions.
Fluoro-functionalized polymeric N-heterocyclic carbene-zinc complexes: efficient catalyst for formylation and methylation of amines with CO2 as a C1-building block
Authors: Yang Zhen-Zhen , Yu Bo , Zhang Hongye , Zhao Yanfei , Ji Guipeng , Liu Zhimin
Published: February 2015

A heterogeneous fluoro-functionalized polymeric N-heterocyclic carbene-zinc complex (F-PNHC-Zn) was designed and prepared for the formylation and methylation of N-methylanilines using CO2 as a C1 building block in the presence of organosilane.
Correction: Applying thermo-destabilization of microemulsions as a new method for co-catalyst loading on mesoporous polymeric carbon nitride – towards large scale applications
Authors: Schröder M. , Kailasam K. , Rudi S. , Fündling K. , Rieß J. , Lublow M. , Thomas A. , Schomäcker R. , Schwarze M.
Published: February 2015

Correction for ‘Applying thermo-destabilization of microemulsions as a new method for co-catalyst loading on mesoporous polymeric carbon nitride – towards large scale applications’ by M. Schröder et al., RSC Adv., 2014, 4, 50017–50026.
Supramolecule-mediated synthesis of MoS2/reduced graphene oxide composites with enhanced electrochemical performance for reversible lithium storage
Authors: Ye Jianbo , Ma Lin , Chen Weixiang , Ma Yingjie , Huang Feihe , Gao Chao , Lee Jim Yang
Published: February 2015

A supramolecule-mediated hydrothermal route was developed for the first time for the facile synthesis of MoS2/rGO composites, which exhibit significantly enhanced electrochemical performance for reversible lithium storage.
Significant piezoelectric and energy harvesting enhancement of poly(vinylidene fluoride)/polypeptide fiber composites prepared through near-field electrospinning
Authors: Pan Cheng-Tang , Yen Chung-Kun , Wu Hui-Chun , Lin Liwei , Lu Yi-Syuan , Huang Jacob Chih-Ching , Kuo Shiao-Wei
Published: February 2015

A flexible PVDF/PMLG energy harvester captures electromechanical energy and its energy conversion efficiency was up to three times higher than individual PVDF and PMLG.
Room temperature interfacial reaction-directed synthesis of hierarchically porous ceria from a water-soluble precursor
Authors: Chen Guozhu , Xu Qihui , Wang Yong , Song Guolong , Fan Weiliu
Published: February 2015

Hierarchically porous ceria was successfully synthesizedviaan interfacial reaction between the water-soluble Ce2(SO4)3precursor and NaOH in ethanol. Neither additional surfactant molecules nor calcination was employed during the preparation process.
Magnetite–polypyrrole core–shell structured microspheres and their dual stimuli-response under electric and magnetic fields
Authors: Park Dae Eun , Chae Hyun Sik , Choi Hyoung Jin , Maity Arjun
Published: February 2015

Polypyrrole (PPy)–coated magnetite (Fe3O4) hybrid particles were synthesized under sonication.
Tuning into blue and red: europium single-doped nano-glass-ceramics for potential application in photosynthesis
Authors: Chen Daqin , Wan Zhongyi , Zhou Yan , Xiang Weidong , Zhong Jiasong , Ding Mingye , Yu Hua , Ji Zhenguo
Published: February 2015

Nano-glass-ceramics, which can convert ultraviolet photons into blue/red ones, were explored for potential application in the photosynthesis of plants.
Retrocyclins neutralize bacterial toxins by potentiating their unfolding
Authors: Kudryashova Elena , Seveau Stephanie , Lu Wuyuan , Kudryashov Dmitri S.
Published: February 2015

We demonstrate that retrocyclins (RCs), promising therapeutic peptides, neutralize bacterial toxins by inducing their unfolding and exposing hydrophobic regions, normally buried in the molecule interior, to solvents. RC-induced toxin unfolding leads to toxin precipitation, proneness to proteolytic degradation and abrogated activity.
High selectivity and common‐mode suppression wideband balanced bandpass filter using slotline resonator
Authors: Deng Hong‐wei , Zhao Yong‐jiu , He Ying , Liu Hao , Wang Hong‐li
Published: February 2015

Novel wideband balanced bandpass filter with high selectivity and common‐mode (CM) suppression is constructed with slotline resonator. When the intersection points of the microstrip feedline and slotline resonator are close to the midpoint of the slotline resonator, the coupling between the fundamental mode of the slotline resonator and microstrip feedline can be maximised, whereas the second mode can be suppressed. Making use of this feature, the third‐order wideband filter with low insertion loss, wide upper‐stopband and flat group delay is designed by using the slotline resonator and two quarter‐wavelength microstrip resonators paralleled to the slotline resonator with tapped‐line coupling at their short‐circuited ends. Based on the third‐order single‐ended filter structure, a novel balanced ﬁlter with a 1 dB fractional bandwidth up to 72% is designed with low insertion loss and enhanced CM suppression. To improve the selectivity, the fifth‐order wideband balanced filter with wide upper‐stopband is designed with parallel coupling structure between two slotline resonators. The corresponding CM suppression is better than 42 dB within the whole differential mode passband. The wideband balanced filter is designed and fabricated, and good agreement between measurements and simulations is obtained.
Optimisation of chirped and tapered microstrip Koch fractal electromagnetic bandgap structures for improved low‐pass filter design
Authors: Ruiz Juan de Dios , Martínez‐Viviente Félix Lorenzo , Hinojosa Juan
Published: February 2015

This study presents electromagnetic bandgap (EBG) structures in microstrip technology based on one‐dimensional Koch fractal patterns (Koch fractal EBG (KFEBG)). This fractal geometry allows to adjust the radius r and distance a between patterns so that a low‐pass filter response is obtained when the ratio r/a is higher than 0.5. However, in such case undesired strong ripples appear in the low bandpass region. We demonstrate that the performance in the passband of this filter can be improved by applying a tapering function to the Koch fractal dimensions and to the width of the microstrip line, while simultaneously chirping (modulating) the Koch fractal periodic pattern distance (a) so as to maintain a constant r/a ratio. Several tapering functions scaled by a factor K are presented, and the results of their application to the KFEBG microstrip structure are compared by means of relevant characteristic parameters. Optimal performance has been obtained for the Kaiser and Cauchy distributions applied to the Koch fractal pattern, combined with a rectangular and Cauchy distribution applied to the microstrip width, respectively.
Improved method of reactive loading for miniaturisation of transmission lines with minimal degradation in performance
Authors: Lim Taejun , Lee Seungku , Lee Yongshik
Published: February 2015

This study presents an improved method of constant reactive loading for the miniaturisation of quarter‐wavelength transmission lines. The method provides an optimum location for loading, which maintains the electrical characteristics before and after miniaturisation. Therefore circuits based on transmission lines can be miniaturised with negligible deterioration in performance. This simple yet highly effective method is especially attractive for popular multi‐section circuits, in which a number of sections are cascaded for wider bandwidths. Experimental results of various Chebyshev multi‐section impedance transformers not only verifies the effectiveness of this method in bandwidths as large as 99% with a size reduction of more than 55%, but also demonstrates the method's flexibility of design.
Analysis, control and experimental verification of a single‐phase capacitive‐coupling grid‐connected inverter
Authors: Dai Ning‐Yi , Zhang Wen‐Chen , Wong Man‐Chung , Guerrero Josep M. , Lam Chi‐Seng
Published: February 2015

This study proposes a capacitive‐coupling grid‐connected inverter (CGCI), which consists of a full‐bridge single‐phase inverter coupled to a power grid via one capacitor in series with an inductor. The fundamental‐frequency impedance of the coupling branch is capacitive. In contrast with the conventional inductive‐coupling grid‐connected inverter (IGCI), this structure provides an alternative interface for use between a low‐voltage DC microgrid and an AC grid. A comparison between the CGCI and the IGCI is performed. It is concluded that the CGCI is able to transfer active power and provide lagging reactive power at an operational voltage much lower than that of the IGCI. This reduces the system's initial cost and operational losses, as well as the energy stored in the DC‐link capacitor. The CGCI has been analysed and a DC voltage selection method is proposed. Using this method, the DC‐link voltage of the CGCI remains at approximately of 50% of the peak grid voltage. In addition, a P‐unit current controller is proposed for use with the CGCI, as a proportional–integral controller is not suitable. Finally, simulation and experiments show the effectiveness of the proposed approach.
Particle swarm optimisation in efficiency improvement of vector controlled surface mounted permanent magnet synchronous motor drive
Authors: Sreejeth Mini , Singh Madhusudan , Kumar Parmod
Published: February 2015

Application of particle swarm optimisation (PSO) in efficiency optimisation of vector controlled surface mounted permanent magnet synchronous motor (PMSM) drive is presented in this study. Analytical expressions for the controllable electrical loss in PMSM are derived and optimised through control of direct axis (d‐axis) stator current, according to the desired speed of operation and load torque. The optimal value of d‐axis current has been obtained through analytical method as well as through PSO. The motor efficiency is maximised by using the optimal d‐axis current to minimise the air gap flux, resulting in reduction of the core losses, especially at light load conditions. The robustness of the efficiency optimisation algorithms are demonstrated through parametric sensitivity analysis. Implementations of efficiency optimisation algorithms are carried out in Matlab and the performance of PMSM drive is described under steady state as well as transient operating conditions. The effect of efficiency optimisation algorithms in different region of operation of PMSM such as constant speed‐variable load torque and constant torque–variable speed modes are described.
Zero‐steady‐state‐error compensation method in application of peak current mode buck converter with fast transient response
Authors: Yao Yunpeng , Xu Shen , Lu Shengli , Sun Weifeng
Published: February 2015

A novel zero‐steady‐state‐error (ZSSE) compensation technique based on an accurate small signal model of peak current mode buck converter is proposed for optimising the microprocessors with low power consumption needing high‐definition voltage scaling. This technique eliminates the steady‐state error of output voltage without negatively affecting the transient response. The main parasitic parameters of the buck converter are taken into consideration to design an excellent ZSSE compensation module; the relationships between the parameters of the compensation circuit and parameters of the other parts of the converter have been derived in this study. This technique has been implemented on a prototype. The validity of this method is shown and confirmed by test results.
Multi‐resolution analysis for converter switch faults identification
Authors: Keswani Rashmi A. , Suryawanshi Hiralal Murlidhar , Ballal Makarand Sudhakar
Published: February 2015

Multilevel inverters (MLI) are extensively used in various fields and industrial applications. This study proposes a simple algorithm for detection and identification of switch faults in insulated gate bipolar transistors (IGBTs) of multilevel inverter feeding an induction motor drive. The effects on the system for switch shorted are more severe than the switch opened if no protective action is taken in time. A fast and novel fault identifier designed in this study is used not only for switch short fault but also for switch open fault by analysing the performance of MLI drive system using wavelet based multi‐resolution analysis (MRA). On occurrence of switch fault in inverter, the fault information appears in the signals in frequency region resulting in variation in the details of level of wavelet transform (WT). The instant of variation in the WT is correlated with the instant of fault. The voltage and current signals from the experimental setup were used as input for wavelet analysis to develop suitable feature vector that will act as signature to discriminate faulty system from healthy one. The experimental prototype of five level diode clamped multilevel inverter feeding an induction motor has been implemented to validate the fault analysis with simulated result.
DC/DC converter with parallel input and parallel output with shared power switches and rectifier diodes
Authors: Lin Bor‐Ren , Chu Chung‐Wei
Published: February 2015

A DC/DC converter with parallel input and parallel output circuit topology is presented to achieve the main features of reduced switch count and medium power level compared with conventional parallel half‐bridge resonant converter. The proposed converter has three resonant circuits to share load currents and reduce the current stress of circuit components. These three resonant circuits use the same power switches to deliver power from input side to output load so that the switch counts are reduced compared with the conventional parallel resonant converter. The rectifier diodes at the secondary side of three resonant circuits are partially used in common so that the diode counts are also reduced. Since three resonant circuits are connected in parallel, the sizes of the transformers and active and passive components are reduced. The switching frequency of the proposed converter is operated to be less than the series resonant frequency. Thus, active switches are turned on under zero voltage switching and rectifier diodes are turned off under zero current switching. A 1.6 kW laboratory prototype is designed and constructed to demonstrate the feasibility and performance of the proposed circuit.
Generalised persymmetric parametric adaptive coherence estimator for multichannel adaptive signal detection
Authors: Gao Yongchan , Liao Guisheng , Zhu Shengqi , Yang Dong
Published: February 2015

In this study, the authors deal with the problem of detecting a signal in partially homogeneous environments, where both the test data and the training data share the same covariance matrix up to an unknown scaling factor. A generalised persymmetric parametric adaptive coherence estimator (GPer‐PACE) detector is proposed, where the disturbance is modelled as a multichannel autoregressive process. To mitigate the effect of limited training samples, the subspatial aperture smoothing is performed in the design of the authors’ GPer‐PACE detector. Moreover, the persymmetric structure information is exploited to further reduce the sample requirements. The performance of the GPer‐PACE is assessed by numerical examples. The results show that the GPer‐PACE outperforms other traditional detectors in sample‐deficient scenarios.
Approach for space‐based radar manoeuvring target detection and high‐order motion parameter estimation
Authors: Huang Penghui , Liao Guisheng , Yang Zhiwei , Shu Yuxiang , Du Wentao
Published: February 2015

The detection of manoeuvring target for space‐based radar is a challenging task because of its weak energy and manoeuvring motion. Prolonging the integration time is an effective method to increase signal energy, which can improve the target detection performance. However, with the increase of integration time, the radial velocity, radial acceleration and radial acceleration rate of manoeuvring target will induce linear range walk, quadratic‐range curvature, cubic‐range curvature and Doppler frequency migration of echo signal, which may degrade the performance of target detection. To solve this problem, a novel method is proposed that implements a parameter separation transform to isolate the acceleration. Then, the velocity and the acceleration rate can be obtained via one‐dimensional search after the compensation of linear and cubic‐range migration based on Hough transform and third‐order Keystone transform. The kernel steps are as follows: (i) the acceleration is isolated by multiplying the range‐compressed data in range frequency domain by its time‐reversed data according to the symmetrical property of azimuth slow time; (ii) the cubic‐range curvature is corrected by a third‐order Keystone transform. The simulation results demonstrate the effectiveness of the proposed method in estimating radial velocity, radial acceleration and radial acceleration rate of a manoeuvring target, thereby the signal energy can be finely accumulated.
Three‐dimensional interferometric inverse synthetic aperture radar imaging with limited pulses by exploiting joint sparsity
Authors: Chen Qianqian , Xu Gang , Zhang Lei , Xing Mengdao , Bao Zheng
Published: February 2015

For manoeuvring targets, long coherent processing interval observation results in a serious time‐varying Doppler modulation that is difficult to achieve high quality three‐dimensional (3D) interferometric inverse synthetic aperture radar (InISAR) images. In this study, a novel 3D InISAR imaging algorithm with limited pulses for manoeuvring targets is proposed. First, the authors formulate a joint sparsity‐constraint optimisation to reconstruct super‐resolution multi‐channel inverse synthetic aperture radar images simultaneously. Then, high quality 3D images of the target can be achieved via the conventional interferometry technique. The main advantages of the proposed approach are: (i) by exploiting joint sparsity property of the InISAR multi‐channel signals, it can effectively improve the recovery precision of scattering centres of the target; and (ii) it can preserve the cross‐channel information, and hence, accurate interferometric phase can be obtained. Both simulated and real data experimental results demonstrate the effectiveness of the proposed algorithm.
Degarbling Mode S replies received in single channel stations with a digital incremental improvement
Authors: Galati Gaspare , Petrochilos Nicolas , Piracci Emilio G.
Published: February 2015

Multilateration and automatic dependent surveillance – broadcast systems are used in air traffic control to detect, locate and identify cooperating aircraft using signals emitted by airborne transponders and received by dedicated ground stations. In areas with a high traffic density, these stations may receive simultaneously several superimposed signals. Present operational systems use only one receiving channel connected to a non‐directional antenna. When the received replies are superimposed, that is, ‘garbled’, their detection and/or decoding are severely affected in nowadays equipment. The aim of this study is to transform the single channel problem into a multiple channels problem in order to solve it using specific knowledge about the Mode S signals. In fact, the multiple channels problem is a typical signals separation problem applied to Mode S mixture for which several algorithms already exist. The authors' algorithm, named projection algorithm (PA) single antenna, is based on the existing PA and can be easily implemented on existing receiving stations. The effectiveness of their method is demonstrated using real data collected from their experimental receiver.
Synthesis of octahedral Co3O4 via carbon‐assisted method
Authors: Zhang Qiang , Gao Libo , Chou Xiujian , Diwu Jiangtao , Xu Hongyan , Xue Chenyang
Published: February 2015

Octahedral Co3O4 (∼1 μm) was synthesised by a one‐step carbon‐assisted method using degreasing cotton and cobalt chloride as precursors. The characterisation results show that the calcination temperature, calcination time, reaction precursor, oxygen environment and reactants ratio of the precursor play important roles in fabricating the Co3O4 powders. The result of the UV‐vis spectrum also shows that the octahedral Co3O4 obtained can be applied in photocatalytic water splitting under visible light irradiation.
Near-field behavior of variable property jet with swirling flow generated by a change in gravitational orientation
Authors: Adzlan Ahmad , Tsutsumi Shunsuke , Gotoda Hiroshi
Published: February 2015

This paper presents the near-field behavior of a variable property jet with swirling flow generated by a change in gravitational orientation, focusing on the onset of vortex formation at the jet interface and the subsequent vortex breakdown (VB). Two types of gases are used to create a significant difference in the physical properties between the inner and outer fluids: CO2 with high-density and low-viscosity, and helium with low-density and high-viscosity. We propose a nondimensional instability parameter M∗ as a useful index for predicting the onset of vortex formation at a swirling jet interface. Inverted gravity (+1g) enlarges the region of unstable VB of the CO2 jet compared with that in normal gravity (−1g), which clearly shows that the buoyancy force has a significant impact on unstable VB. The trends of the changes in the jet half-angle and stagnation point height are investigated in detail for the preceding stable VB. Our physical model derived by considering the momentum balance in a swirling flow is adopted to understand the mechanism of the notable change in the stagnation point height in +1g with increasing swirl number of the inner jet and Reynolds number of the outer jet.
Full-dimensional and reduced-dimensional calculations of initial state-selected reaction probabilities studying the H + CH4 → H2 + CH3 reaction on a neural network PES
Authors: Welsch Ralph , Manthe Uwe
Published: February 2015

Initial state-selected reaction probabilities of the H + CH4 → H2 + CH3 reaction are calculated in full and reduced dimensionality on a recent neural network potential [X. Xu, J. Chen, and D. H. Zhang, Chin. J. Chem. Phys. 27, 373 (2014)]. The quantum dynamics calculation employs the quantum transition state concept and the multi-layer multi-configurational time-dependent Hartree approach and rigorously studies the reaction for vanishing total angular momentum (J = 0). The calculations investigate the accuracy of the neutral network potential and study the effect resulting from a reduced-dimensional treatment. Very good agreement is found between the present results obtained on the neural network potential and previous results obtained on a Shepard interpolated potential energy surface. The reduced-dimensional calculations only consider motion in eight degrees of freedom and retain the C3v symmetry of the methyl fragment. Considering reaction starting from the vibrational ground state of methane, the reaction probabilities calculated in reduced dimensionality are moderately shifted in energy compared to the full-dimensional ones but otherwise agree rather well. Similar agreement is also found if reaction probabilities averaged over similar types of vibrational excitation of the methane reactant are considered. In contrast, significant differences between reduced and full-dimensional results are found for reaction probabilities starting specifically from symmetric stretching, asymmetric (f2-symmetric) stretching, or e-symmetric bending excited states of methane.
Multiferroic properties of stretchable BiFeO3 nano-composite film
Authors: Hwang J. S. , Cho J. Y. , Park S. Y. , Yoo Y. J. , Yoo P. S. , Lee B. W. , Lee Y. P.
Published: February 2015

We present a simple drop-casting method for preparing multiferroic nano-composite film where BiFeO3 (BFO) nanoparticles (NPs) were evenly dispersed into polyvinyl alcohol (PVA) polymer. BFO NPs used in this work were synthesized by the conventional sol-gel method, having diameter of tens of nm and being in good crystallinity. The BFO NPs were loaded into a highly insulating PVA polymer solution as filler. The multiferroic properties of the film reveal ferromagnetic ordering due to the uncompensated spiral ordering and saturated ferroelectric curves due to the cut-off of current leakage. Moreover, the prepared films show high flexibility and their multiferroicities are preserved well even in a high curved condition, reflecting the possibility for fabricating wearable devices based on multiferroic materials.
Amplitude modulation of quantum-ion-acoustic wavepackets in electron-positron-ion plasmas: Modulational instability, envelope modes, extreme waves
Authors: Rahman Ata-ur- , Kerr Michael Mc , El-Taibany Wael F. , Kourakis Ioannis , Qamar A.
Published: February 2015

A semirelativistic fluid model is employed to describe the nonlinear amplitude modulation of low-frequency (ionic scale) electrostatic waves in an unmagnetized electron-positron-ion plasma. Electrons and positrons are assumed to be degenerated and inertialess, whereas ions are warm and classical. A multiscale perturbation method is used to derive a nonlinear Schrödinger equation for the envelope amplitude, based on which the occurrence of modulational instability is investigated in detail. Various types of localized ion acoustic excitations are shown to exist, in the form of either bright type envelope solitons (envelope pulses) or dark-type envelope solitons (voids, holes). The plasma configurational parameters (namely, the relativistic degeneracy parameter, the positron concentration, and the ionic temperature) are shown to affect the conditions for modulational instability significantly, in fact modifying the associated threshold as well as the instability growth rate. In particular, the relativistic degeneracy parameter leads to an enhancement of the modulational instability mechanism. Furthermore, the effect of different relevant plasma parameters on the characteristics (amplitude, width) of these envelope solitary structures is also presented in detail. Finally, the occurrence of extreme amplitude excitation (rogue waves) is also discussed briefly. Our results aim at elucidating the formation and dynamics of nonlinear electrostatic excitations in superdense astrophysical regimes.
Non-orthogonal spin-adaptation of coupled cluster methods: A new implementation of methods including quadruple excitations
Authors: Matthews Devin A. , Stanton John F.
Published: February 2015

The theory of non-orthogonal spin-adaptation for closed-shell molecular systems is applied to coupled cluster methods with quadruple excitations (CCSDTQ). Calculations at this level of detail are of critical importance in describing the properties of molecular systems to an accuracy which can meet or exceed modern experimental techniques. Such calculations are of significant (and growing) importance in such fields as thermodynamics, kinetics, and atomic and molecular spectroscopies. With respect to the implementation of CCSDTQ and related methods, we show that there are significant advantages to non-orthogonal spin-adaption with respect to simplification and factorization of the working equations and to creating an efficient implementation. The resulting algorithm is implemented in the CFOUR program suite for CCSDT, CCSDTQ, and various approximate methods (CCSD(T), CC3, CCSDT-n, and CCSDT(Q)).