bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling and analysis of a conventional and localized electromagnetic bandgap structures for suppression of simultaneous switching noise
Authors: Kim Sang‐Gyu , Kim Hyun , Kang Hee‐do , Yook Jong‐Gwan
Published: April 2012

The transmission line method (TLM) is applied for the analysis of a conventional electromagnetic bandgap (EBG) and enhanced moat structures with an arbitrary shaped power/ground plane. Fast and accurate modeling by TLM reveals computationally efficient results as compared to 3D full‐wave electromagnetic analysis. Moreover, it is shown that the suppression bandwidth of an EBG structure can be easily analyzed with stepped impedance filter approach, and the calculated bandwidth is identical to the measured bandwidth. In general, the conventional EBG structure provides highly efficient suppression of simultaneous switching noise (SSN) over the broadband range; however, it is difficult to apply this concept to real PCB design for high‐speed digital circuits due to degeneration of the signal integrity (SI) performance. In this work, an enhanced localized EBG structure is suggested to enlarge the suppression bandwidth by modifying the EBG pattern without causing any SI problem. The number of bridges for each pattern is minimized, and a meander‐shaped bridge is used to increase the inductance of the bridge. As a result, good suppression of SSN is achieved from 0.8 to 6.5 GHz with a −25 dB suppression level. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1571–1577, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26910
Electrically thin free‐standing phase and amplitude shifting surface for beam shaping applications
Authors: Gagnon N. , Petosa A. , McNamara D. A.
Published: April 2012

A free‐standing phase and amplitude shifting surface (PASS) composed of four conductive layers separated by electrically thin dielectric sheets is presented in this article.This surface can be used for applications in which one must control both the phase and amplitude of electromagnetic waves propagating through it at every location over the aperture. The PASS provides a simple and efficient technique for manipulating the radiation pattern from a feed antenna for beam shaping applications. As a proof of concept, the technique is applied in the design of a flat‐topped shaped beam antenna. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1566–1571, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26911
Microwave absorption characteristics of substituted Ba0.5Sr0.5MxFe(12−2x)O19 (M = Co2+Zr4+ AND Co2+Ti4+) sintered ferrite at X‐band
Authors: Singh Charanjeet , Bindra Narang S. , Koledintseva M.Y.
Published: April 2012

The microwave reflection loss (RL) of four series of synthesized ferrites, Ba0.5Sr0.5CoxZrxFe(12 − 2x)O19 and Ba0.5Sr0.5CoxTixFe(12 − 2x)O19, have been measured using network analyzer in the frequency range from 8.2 to 12.4 GHz. The comprehensive analysis of RL is carried out as a function of substitution, frequency, and thickness. The various models contributing to large RL are described. The composition accompanying maximum microwave absorption is suggested. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1661–1665, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26912
LS band antenna backed by surface wave structure
Authors: Reddy G. Shrikanth , Alex Zachariah C.
Published: April 2012

In this article, a LS band (1.5–2.3 GHz) antenna is presented.Here, the antenna is backed by partial ground and periodic surface wave structure. Both the simulated and experimental result shows that the proposed antenna acquires a bandwidth of 38.8%, that is, 1.5–2.2 GHz and an end fire radiation pattern with a beam width of 108° and maximum gain of 6.5 dbi at 2.1 GHz. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1556–1559, 2012, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26914
Design and implementation of A 24‐/60‐GHz dual‐band monopole meander‐line planar CMOS antenna
Authors: Lin Chih‐Ying , Lin Yo‐Sheng , Lu Hsin‐Chia , Chang Yi‐Long
Published: April 2012

This article describes the design and implementation of a monolithic 24/60‐GHz dual‐band millimeter‐ wave planar CMOS antenna.A finite element method‐based 3D full‐wave electromagnetic solver, high‐frequency structure simulator, is used to simulate and optimize the performance of the antenna. The feeding network adopts the coplanar waveguide (CPW) structure, so the on‐chip antenna can be flip‐chip‐bonded to a CPW RO4003 conversion board for complete radiation‐pattern measurement. The main structure uses meander‐line to save chip area. Dual‐band operation is achieved by providing two major current paths for radiation. The measured input voltage standing wave ratio of the on‐chip dual‐band antenna is smaller than 2 for frequencies 10–25.7 and 58.4–66.6 GHz. The measured maximum power gain is −7 dB at 60 GHz, one of the highest power gains ever reported for a CMOS antenna at 60 GHz. The chip area is only 1 × 0.75 mm2, i.e., 0.75 mm2, excluding the periphery conductor and the dummy metals for metal density requirement. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1731–1737, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26916
Characteristics of circular patch antenna with and without air gaps
Authors: Biswas M. , Banik S.
Published: April 2012

The characteristics of circular patch antenna (CPA) with and without air gaps in between substrate and ground plane are thoroughly investigated. We present a set of closed‐form expressions based on cavity model analysis to predict accurately the characteristics of CPA with and without air gaps. The proposed model is valid for both coaxial‐fed and microstrip line‐fed CPA operated in dominant and higher order modes. The computed values for wide range of antenna parameters, feed locations, and air gaps are compared with different experimental and theoretical values available in open literature. The present model is fast, simple, and closer to the experiments compared with the other models. We have also used a simulator to validate the present model. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1692–1699, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26917
Electromagnetic bandgap solution for mitigation of parallel‐plate noise in power distribution networks
Authors: Sabata A. De , Matekovits L.
Published: April 2012

A solution for mitigation of parallel‐plate noise in power distribution networks of high speed digital and mixed‐signal circuits and of printed circuit boards based on an inhomogeneous parallel‐plate waveguide (PPW) is proposed. The PPW consists of two different dielectric layers and a high impedance surface at their interface. The frequency related properties of the structure are studied through the numerically computed dispersion diagram. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1689–1692, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26918
A very compact CPW‐FED ultra‐wideband circular monopole antenna
Authors: Mahdavi Mehdi , Atlasbaf Zahra , Forooraghi Keyvan
Published: April 2012

A very compact printed circular monopole antenna for ultra‐wideband applications is presented. To achieve wide bandwidth performance, the proposed antenna is fed by a coplanar waveguide feedline. The total size of antenna is as small as 12 mm× 22 mm × 0.787 mm. The simulated and measured results demonstrate an impedance bandwidth covering 2.9–11.6 GHz for return loss less than −10 dB, which indicates that the proposed antenna performance is appropriate for UWB applications. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1665–1668, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26920
Erratum: Multi‐functional channel selective RF receiver system for low‐power sensor network applications
Authors: Lee Kyoung‐Joo , Lee Heejong , Kim Young‐Sik , Lim Jongsik , Han Sang‐Min
Published: April 2012

Originally published Microwave Opt Technol Lett 54: 847–851, 2012. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54: 1775, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26921 (Original article DOI 10.1002/mop.26699)
Erratum: New UWB antenna design for wireless communications
Authors: Bitchikh M. , Aksas R. , Kimouche H. , Azrar A.
Published: April 2012

Originally published Microwave Opt Technol Lett 54: 692–697, 2012. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54: 1775, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26922 (Original article DOI 10.1002/mop.26666)
Erratum: Novel tri‐band antenna endloaded with koch fractal loops
Authors: Zhou Jianhua , Luo Yong , You Baiqiang , Yan X.J.
Published: April 2012

Originally published Microwave Opt Technol Lett 54: 620–623, 2012. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54: 1775, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26923 (Original article DOI 10.1002/mop.26657)
Erratum: Novel pressure sensor using a HI‐BI photonic crystal fiber FLM and its demodulation method
Authors: Zhao Yong , Song Ting‐ting , Wang Qi
Published: April 2012

Originally published Microwave Opt Technol Lett 54: 915–917, 2012. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54: 1775, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26924 (Original article DOI 10.1002/mop.26738)
Erratum: Novel compact low temperature cofired ceramic ultrawideband sir bandpass filter using different coupling schemes
Authors: Kewei Qian , Chanjuan Fan
Published: April 2012

Originally published Microwave Opt Technol Lett 54: 967–970, 2012. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54: 1775, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26925 (Original article DOI 10.1002/mop.26679)
High frame rate retrospectively triggered Cine MRI for assessment of murine diastolic function
Authors: Coolen Bram F. , Abdurrachim Desiree , Motaal Abdallah G. , Nicolay Klaas , Prompers Jeanine J. , Strijkers Gustav J.
Published: April 2012

To assess left ventricular (LV) diastolic function in mice with Cine MRI, a high frame rate (>60 frames per cardiac cycle) is required. For conventional electrocardiography‐triggered Cine MRI, the frame rate is inversely proportional to the pulse repetition time (TR). However, TR cannot be lowered at will to increase the frame rate because of gradient hardware, spatial resolution, and signal‐to‐noise limitations. To overcome these limitations associated with electrocardiography‐triggered Cine MRI, in this paper, we introduce a retrospectively triggered Cine MRI protocol capable of producing high‐resolution high frame rate Cine MRI of the mouse heart for addressing left ventricular diastolic function. Simulations were performed to investigate the influence of MRI sequence parameters and the k‐space filling trajectory in relation to the desired number of frames per cardiac cycle. An optimized protocol was applied in vivo and compared with electrocardiography‐triggered Cine for which a high‐frame rate could only be achieved by several interleaved acquisitions. Retrospective high frame rate Cine MRI proved superior to the interleaved electrocardiography‐triggered protocols. High spatial‐resolution Cine movies with frames rates up to 80 frames per cardiac cycle were obtained in 25 min. Analysis of left ventricular filling rate curves allowed accurate determination of early and late filling rates and revealed subtle impairments in left ventricular diastolic function of diabetic mice in comparison with nondiabetic mice. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.
Rituximab in refractory and non‐refractory myasthenia: A retrospective multicenter study
Authors: Collongues Nicolas , Casez Olivier , Lacour Arnaud , Tranchant Christine , Vermersch Patrick , de Seze Jérôme , Lebrun Christine
Published: April 2012

Introduction:

Few data are available about the effect of rituximab (RTX) on refractory (RM) and non‐refractory (NRM) myasthenia.

Methods:

This retrospective multicenter study involved 13 RM and 7 NRM patients treated with sequential RTX infusions over 2 years, on average. RTX was used as a substitute for corticosteroids in NRM patients. Disability was assessed using the annualized relapse rate (ARR) and Myasthenia Gravis Foundation of America (MGFA) scores.

Results:

RTX induction decreased the ARR from 2.1 to 0.3 (P < 0.001), and lowered MGFA scores from 5–3b to 4b–0 in RM patients, and from 1.9 to 0.1 (P < 0.001) and 4b–2b to 3b–0 in NRM patients. No side effects were reported in either group, except for 1 case of spondylodiscitis 1 year after the last RTX infusion. Within a year after RTX induction, complete corticosteroid withdrawal was obtained in 7 RM and 4 NRM patients.

Conclusions:

RTX is efficacious and well‐tolerated. Its use allows for dose reduction or withdrawal of corticosteroids. Muscle Nerve, 2012
Cross‐sectional and longitudinal analysis of an oxidative stress biomarker for spinal and bulbar muscular atrophy
Authors: Mano Tomoo , Katsuno Masahisa , Banno Haruhiko , Suzuki Keisuke , Suga Noriaki , Hashizume Atsushi , Tanaka Fumiaki , Sobue Gen
Published: April 2012

Introduction:

Spinal and bulbar muscular atrophy (SBMA) is an adult‐onset motor neuron disease caused by a CAG repeat expansion in the androgen receptor gene. The aim of this study was to verify whether urinary 8‐hydroxydeoxyguanosine (8‐OHdG), an oxidative stress marker, is a biomarker for SBMA.

Methods:

We measured the levels of urinary 8‐OHdG in 33 genetically confirmed SBMA patients and 32 age‐matched controls over a 24‐month period at 6‐month intervals.

Results:

Urinary 8‐OHdG levels in SBMA patients were significantly elevated compared with those of controls and correlated well with motor function scores. During the follow‐up period, urinary 8‐OHdG levels increased and correlated with motor function at each time‐point. In addition, urinary 8‐OHdG levels at baseline were correlated with changes in the 6‐minute walk test during 24 months.

Conclusions:

Urinary 8‐OHdG is a biomarker for SBMA, reflecting the severity and possibly predicting the deterioration of motor function. Muscle Nerve, 2012
Ocular neuropathy in peripheral neuropathies
Authors: Evliyaoglu Ferhat , Karadag Remzi , Burakgazi Ahmet Z.
Published: April 2012

Ocular movements and coordination require complex and integrated functions of somatic and autonomic nervous systems. Neurological disorders affecting these nervous systems may cause ocular dysfunction involving extraocular muscles and pupils. In this article, the prevalence, clinical presentations, and management of ocular neuropathy related to certain peripheral neuropathies, including diabetic neuropathy, Guillain–Barré syndrome (GBS), chronic inflammatory neuropathies, human immunodeficiency virus (HIV)‐associated neuropathy, and hereditary neuropathies, are examined in detail. Muscle Nerve 46: 681–686, 2012
Mass spectrometry analysis reveals non‐mutated apolipoprotein a1 lumbosacral radiculoplexus amyloidoma
Authors: Loavenbruck Adam J. , Chaudhry Vinay , Zeldenrust Steven R. , Spinner Robert J. , Theis Jason D. , Klein Christopher J.
Published: April 2012

Introduction: In rare instances, amyloidosis presents as a focal, macroscopic lesion involving peripheral neural tissues (amyloidoma). In all known reported cases, peripheral nerve amyloidomas have had immunoglobulin light‐chain fibril composition and occurred in the context of paraproteinemia. Methods: A 46‐year‐old man presented with progressive insidious‐onset right lumbosacral radiculoplexus neuropathy without paraproteinemia. MRI‐targeted fascicular nerve biopsy was performed on an enlarged sciatic nerve after earlier distal fibular nerve biopsy was nondiagnostic. Laser dissected mass spectroscopy of the discovered amyloid protein was performed after immunohistochemistry failed to identify the specific amyloid protein. Complete gene sequencing of apolipoprotein A1 (ApoA1) was performed. Results: Only wild‐type ApoA1 amyloid was found in the congophilic component in the nerve. Conclusions: This case highlights the utility of MRI‐guided fascicular nerve biopsy combined with laser‐dissected mass spectrometric analysis. Importantly, the case expands the known causes of amyloidomas to include wild‐type ApoA1. Muscle Nerve 46: 817–822, 2012
Preliminary study of sural nerve morphological changes in uremic hemodialysis patients using 22‐MHz high‐frequency ultrasound
Authors: Wei Mei , Zhu Jiaan , Wang Niansong , Xue Qing , Liu Fang , Hu Bing , Fang Junchu , Zhang Yingchun
Published: April 2012

Introduction: The aim of this study was to evaluate the ultrasound (US) morphological changes of sural nerves (SNs) of uremic patients on hemodialysis. Methods: Sixty‐six SNs in 33 uremic patients were examined by 22‐MHZ high‐frequency US and routine nerve conduction studies (NCS), and 76 SNs in 38 controls were also examined. Cross‐sectional area (CSA) and maximal fascicular thickness (MFT) of the SNs were measured. Results: The inner parts of the SN were clearly identified in all participants. There were significant increases in CSA and MFT in the patient group (1.86 ± 0.53 mm2 and 0.37 ± 0.08 mm, respectively) compared with the control group (1.38 ± 0.25 mm2 and 0.32 ± 0.03 mm, respectively) (P < 0.001). Fifty‐seven SNs (86.36%) had abnormal CSAs, and 51 SNs (77.27%) had abnormal MFTs in the patient group, which was higher than NCS abnormalities (66.67%). Conclusions: A 22‐MHZ US can show morphological changes in the SNs of uremic patients and may be a valuable tool. Muscle Nerve, 2012
Nested column generation applied to the crude oil tanker routing and scheduling problem with split pickup and split delivery
Authors: Hennig Frank , Nygreen Bjørn , Lübbecke Marco E.
Published: April 2012

The split pickup split delivery crude oil tanker routing and scheduling problem is a difficult combinatorial optimization problem, both theoretically and practically. However, because of the large expenses in crude oil shipping it is attractive to make use of optimization that exploits as many degrees of freedom as possible to save transportation cost. We propose a nested column generation algorithm for this particular split pickup split delivery problem which bears several complexities such as a heterogeneous fleet, multiple commodities, many‐to‐many relations for pickup and delivery of each commodity, sequence dependent vehicle capacities, and cargo quantity dependent pickup and delivery times. Our approach builds on a branch‐and‐price algorithm in which the column generation subproblems are solved by branch‐and‐price themselves. We describe our implementation in the branch‐cut‐and‐price framework SCIP and give computational results for realistic test instances. The high quality schedules we obtain for these instances improve on those in previous studies. © 2012 Wiley Periodicals, Inc. Naval Research Logistics, 2012
Characterization of the homodimerization interface and functional hotspots of the CXCR4 chemokine receptor
Authors: Rodríguez David , Gutiérrez‐de‐Terán Hugo
Published: April 2012

The recent crystallographic structures of the human chemokine CXC Receptor 4 (CXCR4) provide experimental evidence of a human G Protein‐Coupled Receptor (GPCR) dimer in atomic detail. The CXCR4 homodimers reveal an unexpected dimerization mode involving transmembrane helices TM5 and TM6, which is examined here using all‐atom molecular dynamics (MD) simulations in the physiological environment of a lipid bilayer. The bacteriophage T4 lysozyme (T4L), which was fused to the crystallized protein but absent in our simulations, is found to slightly affect the observed relative position of the protomers in the two dimers studied here, and consequently some rearrangements of the dimerization interface are proposed. In addition, the simulations provide further evidence about the role of the two stabilizing single point mutations introduced to crystallize the receptor. Finally, this work analyzes the structural and dynamic role of key residues involved both in ligand binding and in the infection process of HIV. In particular, the different side chain conformations of His1133.39 are found to influence the dynamics of the surrounding functional hotspot region being evaluated both in the presence and in the absence of the co‐crystallized ligand IT1t. The analysis reported here adds valuable knowledge for future structure‐based drug design (SBDD) efforts on this pharmacological target. Proteins 2012;. © 2012 Wiley Periodicals, Inc.
Insecticide toxic effects on Trichogramma ostriniae (Hymenoptera: Trichogrammatidae)
Authors: Wang Yanhua , Chen Liping , Yu Ruixian , Zhao Xueping , Wu Changxing , Cang Tao , Wang Qiang
Published: April 2012

BACKGROUND: The parasitoid Trichogramma ostriniae (Pang and Chen) is a major natural enemy of many lepidopterans, but only a few studies have been conducted on the compatibility of biological and chemical controls. In this study, the selectivity of 30 insecticides to T. ostriniae adults was evaluated.

RESULTS: Among the seven classes of chemicals tested, organophosphates and carbamates had the highest intrinsic toxicity to the wasp, with LC50 values ranging from 0.032 (0.029–0.038) to 2.38 (1.91–3.15) mg AI L−1. They are followed by phenylpyrazoles, avermectins, neonicotinoids and pyrethroids, which induce variable toxicity responses, with LC50 values ranging from 0.14 (0.11–0.21) to 56.67 (48.94–67.24) mg AI L−1, from 2.57 (1.85–4.28) to 4.48 (3.34–6.83) mg AI L−1, from 2.48 (1.80–4.03) to 503.6 (457.6–557.5) mg AI L−1 and from 5.44 (3.95–8.84) to 104.2 (92.48–119.7) mg AI L−1 respectively. The insect growth regulators (IGRs) exhibited least toxicity to the parasitoid.

CONCLUSION: Risk quotient analysis classifies neonicotinoids, avermectins, pyrethroids, IGRs and phenylpyrazoles (with the exception of butane‐fipronil and fipronil) as safe agents to the parasitoid, but categorises organophosphates and carbamates as slightly to moderately toxic or dangerous to T. ostriniae. Copyright © 2012 Society of Chemical Industry
Pair natural orbitals in explicitly correlated second‐order møller–plesset theory
Authors: Tew David P. , Hättig Christof
Published: April 2012

An improved formulation of pair natural orbital (PNO)–based explicitly correlated Møller–Plesset second‐order perturbation theory is presented. Increased efficiency has been achieved by modifying the representation of the strong orthogonality projector used in the evaluation of the F12 intermediates. We demonstrate two simple relationships between the truncation errors arising from PNOs in the virtual space and those arising from the PNOs in the strong orthogonality operators. This permits robust error control through a single parameter.
Statistical physics of a mesoscopic fermion system inside a rectangular box
Authors: Lungu Radu P.
Published: April 2012

An ideal Fermi gas of identical particles confined inside a rectangular box is considered. Using the grand‐canonical formalism and performing the summations over the one‐particle states numerically, the temperature dependence of the chemical potential, of the average energy and of the heat capacity are derived before the thermodynamic limit is taken. These mesoscopic quantities differ from the corresponding thermodynamic quantities only quantitatively but are qualitatively similar. © 2013 Wiley Periodicals, Inc.
TDDFT study on quantization behaviors of nonadiabatic couplings in polyatomic systems
Authors: Hu Chunping , Komakura Ryo , Li Zhengcao , Watanabe Kazuyuki
Published: April 2012

We present extensive calculations on the quantization behaviors of first‐order nonadiabatic couplings (NAC) in polyatomic systems, using the method based on time‐dependent density functional theory (TDDFT). Along circular contours around Jahn–Teller conical intersections at various symmetries, such as D4h and D6h, the angular NAC are found to show apparent dependence on the contour angle, no matter how close the conical intersections are approached. This is in contrast to that the angular NAC in triatomic Jahn–Teller systems (D3h) converge to the quantized value of 1/2. The oscillatory feature of our calculated curves qualitatively resembles the analytic result of angular NAC around elliptic conical intersections in the small‐displacement limit. Furthermore, by performing the integral along the whole contour, the quantization rule on the integral of the angular NAC holds for all cases, which gives the geometric phase with a value of π. On the other hand, the angular NAC in the immediate vicinity of Renner–Teller intersections are shown to be always 1. This observation can be understood from the fact that the molecular symmetry property of the Renner–Teller intersections is always determined by the linear atomic chain. Further analysis of our results on Renner–Teller systems shows that although the quantization behavior of angular NAC can determine all NAC vectors on each atom for the triatomic systems, it cannot for the systems with more than three atoms. The NAC vectors of the latter systems are found to show both common and distinct features with respect to the atomic number and species by our TDDFT calculations. © 2012 Wiley Periodicals, Inc.
Growth mode of CNFs on substrates by using the sputtering method
Authors: Hirase Yuji , Ichikawa Yo
Published: April 2012

Carbon nanoflakes (CNFs) were grown on Si substrates at different substrate temperatures by radio frequency magnetron sputtering. The changes in the shape of CNFs caused by the substrate temperature and the places of CNF growth in the substrate were investigated. The adhesion of carbon materials to the substrate and the growth of crystallized flake‐like structures were found to be dependent on the substrate temperature. At a substrate temperature lower than 550 °C, no material was deposited on the substrate. At a substrate temperature higher than 600 °C, flake‐like carbon microstructures were grown. Therefore, only when the substrate temperature is higher than the crystallization temperature, the adhesion of carbon materials takes place and the CNF grows two dimensionally. In addition, it is suspected that CNF grows selectively in the direction of the greatest supply of sputtered particles. This selective growth is an intrinsic growth mode in the bipolar sputtering method. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Basic solution of four 3‐D rectangular limited‐permeable cracks in piezoelectric materials
Authors: Liu J.‐Y. , Zhou Z.‐G. , Zhou B.‐B.
Published: April 2012

The solution of four 3‐D rectangular limited‐permeable cracks in piezoelectric materials were given by using the generalized Almansi's theorem and the Schmidt method. At the same time, the electric permittivity of the air inside the rectangular crack was considered. The problem was formulated through Fourier transform as three pairs of dual integral equations, in which the unknown variables are the displacement jumps across the crack surfaces. To solve the dual integral equations, the displacement jumps across the crack surfaces were directly expanded as a series of Jacobi polynomials. Finally, the effects of the electric permittivity of the air inside the rectangular crack, the shape of the rectangular crack and the distance among four rectangular cracks on the stress and electric displacement intensity factors in piezoelectric materials were analyzed.
Progress in Myrtaceae genetics and genomics: Eucalyptus as the pivotal genus
Authors: Grattapaglia Dario , Vaillancourt René E. , Shepherd Merv , Thumma Bala R. , Foley William , Külheim Carsten , Potts Brad M. , Myburg Alexander A.
Published: April 2012

The status of genomics and genetics research in the Myrtaceae, a large family of dicotyledonous woody plants, is reviewed withEucalyptusas the focal genus. The family contains over 5,650 species in 130 to 150 genera, predominantly of neo-tropical and Southern Hemisphere distribution. Several genera are well known for their economic importance worldwide. Myrtaceae are typically diploids with small to intermediate genome size. Microsatellites have been developed for several genera while higher throughput marker systems such as diversity arrays technology and single nucleotide polymorphism are available forEucalyptus. Molecular data have been fundamental to current perspectives on the phylogeny, phylogeography and taxonomy of the Myrtaceae, while numerous studies of genetic diversity have been carried out particularly as it relates to endangered, rare, fragmented, overharvested or economically important species. Large expressed sequence tag collections for species ofEucalyptushave recently become public to support the annotation of theEucalyptus grandisgenome. Transcriptomics inEucalyptushas advanced by microarrays and next-generation sequencing focusing on wood development. Linkage maps forEucalyptusdisplay high synteny across species and have been extensively used to map quantitative trait loci for a number of traits including growth, wood quality, disease and insect resistance. Candidate gene-based association genetics have successfully found marker–trait associations for wood and fiber traits. Genomic selection experiments have demonstrated clear potential to improve the efficiency of breeding programs while freeze-tolerant transgenicEucalyptustrials have recently been initiated. The recently releasedE. grandisgenome, sequenced to an average coverage of 8×, will open up exceptional opportunities to advance Myrtaceae genetics and genomics research.
Determining lower urinary tract symptoms and associated risk factors in young women
Authors: Timur‐Taşhan Sermin , Beji Nezihe K. , Aslan Ergül , Yalçin Önay
Published: April 2012

Objective

To determine lower urinary tract symptoms (LUTS) and associated risk factors in women aged 20 years and older.

Methods

The present population‐based, randomized, cross‐sectional study recruited 766 women aged 20 years and older from the province of Malatya, Turkey. Data on LUTS were collected via face‐to‐face interviews between December 1, 2006, and July 30, 2007. The data were reported descriptively and analyzed by logistic regression for associated risk factors.

Results

Regarding female LUTS, the incidence of urgency, urinary incontinence, nocturia, and frequency symptoms was 36.1%, 32.4%, 27.1%, and 22.8%, respectively. Logistic regression indicated that LUTS development was 6.1 times higher among women who had vaginal delivery than among those who had cesarean delivery; 3.7 times higher among women with gas incontinence than among those without; 2.9 times higher among women with frequent urinary tract infections that among those without; and 4.8 times higher among women whose mothers had a history of urine incontinence than among those whose mothers did not.

Conclusion

Vaginal delivery was found to be the highest risk factor for LUTS among women.
Gefährdung älterer Menschen durch Hitzewellen in exponierten Städten
Authors: Bittner Martin-Immanuel , Stößel Ulrich
Published: April 2012

Einleitung

Klimaprognosen gehen von einer in Zukunft steigenden Gefährdung durch Hitzewellen aus. Besonders vulnerabel sind unter anderem ältere Menschen, chronisch Kranke und Alleinlebende; zudem sind städtische Gebiete verstärkt betroffen. In einer explorativen Interviewstudie wurden 2009/10 in Freiburg n = 20 Probanden zu ihrem Schutz- und Mitigationsverhalten bei Hitzewellen befragt. Die Ergebnisse bestätigen, dass die Public Health Forschung in diesem Feld an Bedeutung gewinnt. Mögliche Public Health Interventionen müssen sich auf die genauere Erfassung von Gefährdungslagen und Ressourcen stützen.
Cohomology for Generalized Bredon Coefficient Systems and Higher K-Theory
Authors: Kuku Aderemi
Published: April 2012

Let be a generalized based category (see definition 1.2). In this paper, we construct a cohomology theory in the category of contravariant functors: where R is a commutative ring with identity, which generalizes Bredon cohomology involving finite, profinite or discrete groups.

We also study higher K-theory of the category of finitely generated projective objects in and the category of finitely generated objects in and obtain some finiteness and other results.
Heterogeneous Beliefs and Risk-Neutral Skewness
Authors: Friesen Geoffrey C. , Zhang Yi , Zorn Thomas S.
Published: April 2012

This study tests whether belief differences affect the cross-sectional variation of risk-neutral skewness using data on firm-level stock options traded on the Chicago Board Options Exchange from 2003 to 2006. We find that stocks with greater belief differences have more negative skews, even after controlling for systematic risk and other firm-level variables known to affect skewness. Factor analysis identifies latent variables linked to risk and belief differences. The belief factor explains more variation in the risk-neutral skewness than the risk-based factor. Our results suggest that belief differences may be one of the unexplained firm-specific components affecting skewness.
High-performance computing systems: Status and outlook
Authors: Dongarra J. J. , van der Steen A. J.
Published: April 2012

This article describes the current state of the art of high-performance computing systems, and attempts to shed light on near-future developments that might prolong the steady growth in speed of such systems, which has been one of their most remarkable characteristics. We review the different ways devised to speed them up, both with regard to components and their architecture. In addition, we discuss the requirements for software that can take advantage of existing and future architectures.
Morphogenesis of a protein: folding pathways and the energy landscape
Authors: Brunori Maurizio , Gianni Stefano , Giri Rajanish , Morrone Angela , Travaglini-Allocatelli Carlo
Published: April 2012

Current knowledge on the reaction whereby a protein acquires its native three-dimensional structure was obtained by and large through characterization of the folding mechanism of simple systems. Given the multiplicity of amino acid sequences and unique folds, it is not so easy, however, to draw general rules by comparing folding pathways of different proteins. In fact, quantitative comparison may be jeopardized not only because of the vast repertoire of sequences but also in view of a multiplicity of structures of the native and denatured states. We have tackled the problem of the relationships between the sequence information and the folding pathway of a protein, using a combination of kinetics, protein engineering and computational methods, applied to relatively simple systems. Our strategy has been to investigate the folding mechanism determinants using two complementary approaches, i.e. (i) the study of members of the same family characterized by a common fold, but substantial differences in amino acid sequence, or (ii) heteromorphic pairs characterized by largely identical sequences but with different folds. We discuss some recent data on protein-folding mechanisms by presenting experiments on different members of the PDZ domain family and their circularly permuted variants. Characterization of the energetics and structures of intermediates and TSs (transition states), obtained by Φ-value analysis and restrained MD (molecular dynamics) simulations, provides a glimpse of the malleability of the dynamic states and of the role of the topology of the native states and of the denatured states in dictating folding and misfolding pathways.
G-protein-coupled receptor dynamics: dimerization and activation models compared with experiment
Authors: Taddese Bruck , Simpson Lisa M. , Wall Ian D. , Blaney Frank E. , Kidley Nathan J. , Clark Henry S.X. , Smith Richard E. , Upton Graham J.G. , Gouldson Paul R. , Psaroudakis George , Bywater Robert P. , Reynolds Christopher A.
Published: April 2012

Our previously derived models of the active state of the β2-adrenergic receptor are compared with recently published X-ray crystallographic structures of activated GPCRs (G-protein-coupled receptors). These molecular dynamics-based models using experimental data derived from biophysical experiments on activation were used to restrain the receptor to an active state that gave high enrichment for agonists in virtual screening. The β2-adrenergic receptor active model and X-ray structures are in good agreement over both the transmembrane region and the orthosteric binding site, although in some regions the active model is more similar to the active rhodopsin X-ray structures. The general features of the microswitches were well reproduced, but with minor differences, partly because of the unexpected X-ray results for the rotamer toggle switch. In addition, most of the interacting residues between the receptor and the G-protein were identified. This analysis of the modelling has also given important additional insight into GPCR dimerization: re-analysis of results on photoaffinity analogues of rhodopsin provided additional evidence that TM4 (transmembrane helix 4) resides at the dimer interface and that ligands such as bivalent ligands may pass between the mobile helices. A comparison, and discussion, is also carried out between the use of implicit and explicit solvent for active-state modelling.
Conserved activation pathways in G-protein-coupled receptors
Authors: Deupi Xavier , Standfuss Jörg , Schertler Gebhard
Published: April 2012

GPCRs (G-protein-coupled receptors) are seven-transmembrane helix proteins that transduce exogenous and endogenous signals to modulate the activity of downstream effectors inside the cell. Despite the relevance of these proteins in human physiology and pharmaceutical research, we only recently started to understand the structural basis of their activation mechanism. In the period 2008–2011, nine active-like structures of GPCRs were solved. Among them, we have determined the structure of light-activated rhodopsin with all the features of the active metarhodopsin-II, which represents so far the most native-like model of an active GPCR. This structure, together with the structures of other inactive, intermediate and active states of rhodopsin constitutes a unique structural framework on which to understand the conserved aspects of the activation mechanism of GPCRs. This mechanism can be summarized as follows: retinal isomerization triggers a series of local structural changes in the binding site that are amplified into three intramolecular activation pathways through TM (transmembrane helix) 5/TM3, TM6 and TM7/TM2. Sequence analysis strongly suggests that these pathways are conserved in other GPCRs. Differential activation of these pathways by ligands could be translated into the stabilization of different active states of the receptor with specific signalling properties.
Magnetic reconnection in high-energy-density laser-produced plasmas
Authors: Fox W. , Bhattacharjee A. , Germaschewski K.
Published: April 2012

Recently, novel experiments on magnetic reconnection have been conducted in laser-produced plasmas in a high-energy-density regime. Individual plasma bubbles self-generate toroidal, mega-gauss-scale magnetic fields through the Biermann battery effect. When multiple bubbles are created at small separation, they expand into one another, driving reconnection of this field. Reconnection in the experiments was reported to be much faster than allowed by both Sweet-Parker, and even Hall-MHD theories, when normalized to the nominal magnetic fields self-generated by single bubbles. Through particle-in-cell simulations (both with and without a binary collision operator), we model the bubble interaction at parameters and geometry relevant to the experiments. This paper discusses in detail the reconnection regime of the laser-driven experiments and reports the qualitative features of simulations. We find substantial flux-pileup effects, which boost the relevant magnetic field for reconnection in the current sheet. When this is accounted for, the normalized reconnection rates are much more in line with standard two-fluid theory of reconnection. At the largest system sizes, we additionally find that the current sheet is prone to breakup into plasmoids.
Dust ion acoustic soliton in pair-ion plasmas with non-isothermal electrons
Authors: Mushtaq A. , Nasir Khattak M. , Ahmad Zulfiqar , Qamar A.
Published: April 2012

Dust ion acoustic (DIA) solitons in an unmagnetized pair-ion (PI) plasmas with adiabatic pair-ions, non-isothermal electrons, and negatively charged background dust are investigated, using both small and arbitrary amplitude techniques. An energy integral equation involving the Sagdeev potential is derived, and basic properties of the large amplitude solitary structures are investigated. The effects of dust concentration, resonant electrons, and ion temperatures on the profiles of the Sagdeev potential and corresponding solitary waves are studied. The related Schamel-Korteweg-de Vries (S-KdV) equation with mixed-nonlinearity is derived by expanding the Sagdeev potential. Asymptotic solutions for different orders of nonlinearity are discussed for DIA solitary waves. The present work is applicable to understand the wave phenomena and associated nonlinear electrostatic perturbations in the doped pair ion plasmas, not completely filtered e.g., pair ion-electron plasmas, enriched with an extra massive charged component (e.g., dust defects), which may be academic for the moment but might be of interest for forthcoming experiments in laboratory (space) plasmas.
Fabrication and characterization of controllable grain boundary arrays in solution-processed small molecule organic semiconductor films
Authors: Wo Songtao , Headrick Randall L. , Anthony John E.
Published: April 2012

We have produced solution-processed thin films of 6,13-bis(tri-isopropyl-silylethynyl) pentacene with grain sizes from a few micrometers up to millimeter scale by lateral crystallization from a rectangular stylus. Grains are oriented along the crystallization direction, and the grain size transverse to the crystallization direction depends inversely on the writing speed, hence forming a regular array of oriented grain boundaries with controllable spacing. We utilize these controllable arrays to systematically study the role of large-angle grain boundaries in carrier transport and charge trapping in thin film transistors. The effective mobility scales with the grain size, leading to an estimate of the potential drop at individual large-angle grain boundaries of more than 1 volt. This result indicates that the structure of grain boundaries is not molecularly abrupt, which may be a general feature of solution-processed small molecule organic semiconductor thin films, where relatively high energy grain boundaries are typically formed. Transient measurements after switching from positive to negative gate bias or between large and small negative gate bias reveal reversible charge trapping, with time constants on the order of 10 s and trap densities that are correlated with grain boundary density. We suggest that charge diffusion along grain boundaries and other defects is the rate-determining mechanism of the reversible trapping.
Counterexamples to ferromagnetic ordering of energy levels
Authors: Spitzer Wolfgang , Starr Shannon , Tran Lam
Published: April 2012

The Heisenberg ferromagnet has symmetry group SU(2). The property known as ferromagnetic ordering of energy levels (FOEL) states that the minimum energy eigenvalue among eigenvectors with total spin s is monotone decreasing as a function of s. While this property holds for certain graphs such as open chains, in this note we demonstrate some counterexamples. We consider the spin 1/2 model on rings of length 2n for n = 2, 3, …, 8, and show that the minimum energy among all spin singlets is less than or equal to the minimum energy among all spin triplets, which violates FOEL. This also shows some counterexamples to the “Aldous ordering” for the symmetric exclusion process. We also review some of the literature related to these examples.
Fabrication of glycerol liquid droplet array by nano-inkjet printing method
Authors: Kaisei Kiyohiro , Kobayashi Kei , Matsushige Kazumi , Yamada Hirofumi
Published: April 2012

We have studied a local deposition method based on dynamic-mode AFM using a hollow tip with an aperture. In this method, liquid droplets are deposited onto a conductive substrate through the aperture by applying an electric voltage pulse and are imaged using the same AFM tip immediately after the deposition. In this study, we applied this method to local deposition of a glycerol solution, which can be utilized in the printed electronics and the biosensor fabrication technology. The solution in the hollow was covered with a hydrophobic ionic liquid with an extremely low vapor pressure to prevent the evaporation of the solution because the quick evaporation heavily affected the dynamic-mode AFM operation. We succeeded in the stable deposition of an array of ultrasmall droplets, which contained an added salt and possible involatile residues in the glycerol solution.
Using heavy atom rare gas matrix to control the reactivity of 4-methoxybenzaldehyde: A comparison with benzaldehyde
Authors: Kuş Nihal , Sharma Archna , Reva Igor , Lapinski Leszek , Fausto Rui
Published: April 2012

Different patterns of photochemical behavior were observed for 4-methoxybenzaldehyde (p-anisaldehyde) isolated in xenon and in argon matrices. Monomers of the compound isolated in solid Xe decarbonylate upon middle ultraviolet irradiation, yielding methoxybenzene (anisole), and CO. On the other hand, p-anisaldehyde isolated in an Ar matrix and subjected to identical irradiation, predominantly isomerizes to the closed-ring isomeric ketene (4-methoxycyclohexa-2,4-dien-1-ylidene) methanone. Experimental detection of a closed-ring ketene photoproduct, generated from an aromatic aldehyde, constitutes a rare observation. The difference between the patterns of photochemical transformations of p-anisaldehyde isolated in argon and xenon environments can be attributed to the external heavy-atom effect, where xenon enhances the rate of intersystem crossing from the singlet to the triplet manifold in which decarbonylation (via p-methoxybenzoyl radical) takes place. The parent compound, benzaldehyde, decarbonylates (to benzene + CO) when subjected to middle ultraviolet irradiation in both argon and xenon matrices. This demonstrates the role of the methoxy p-anisaldehyde substituent in activation of the reaction channel leading to the formation of the ketene photoproduct.
Forced generation of simple and double emulsions in all-aqueous systems
Authors: Sauret Alban , Cheung Shum Ho
Published: April 2012

We report an easy-to-implement method that allows the direct generation of water-in-water (w/w) single emulsions. The method relies on direct perturbation of the pressure that drives the flow of the dispersed phase of the emulsions. The resultant inner jet is induced to break up into droplets due to the growth of the perturbation through Rayleigh-Plateau instability [L. Rayleigh, Proc. R. Soc. London 29, 71–97 (1879)]; this leads to the formation of monodisperse droplets. By implementing this method on a modified microfluidic device, we directly generate water-in-water-in-water (w/w/w) double emulsions with good control over the size and the number of encapsulated droplets. Our approach suggests a route to apply droplet-based microfluidics to completely water-based systems.
A formation mechanism for ultra-thin nanotwins in highly textured Cu/Ni multilayers
Authors: Liu Y. , Bufford D. , Rios S. , Wang H. , Chen J. , Zhang J. Y. , Zhang X.
Published: April 2012

High density nanotwins with average twin thickness varying from 3 to 6 nm are formed in sputtered highly (111) textured Cu/Ni multilayers, when individual layer thickness is 25 nm or less. Twin interfaces are normal to growth direction. Both maximum twin thickness and volume fraction of twins vary with the individual layer thickness. Coherency stress plays an important role in tailoring the formation of nanotwins. Nanotwins compete with misfit dislocations in accommodating elastic strain energy in epitaxial Cu/Ni multilayers.