bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of a novel prime code in IP transmission and routing over FSK‐OCDMA in an optical network unit
Authors: Zoualfaghari M. H. , Ghafouri‐Shiraz H. 
Published: September 2012

AbstractIn this letter, we have analyzed the Internet protocol transmission and routing over frequency‐shift keying optical code division multiple access based on a novel optical code.This code enhances the system bit error rate, packet error rate, number of simultaneous subscribers, and security, as compared to the other prime codes. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2852–2856, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27213
Design of low voltage, low power CMOS low noise amplifier for 2.4 GHz wireless communications
Authors: Huang Chien‐Chang , Ku Kai‐Wei 
Published: September 2012

AbstractIn this letter, design of a low voltage, low power CMOS low noise amplifier (LNA) for 2.4 GHz wireless communications is presented by using TSMC 0.18‐μm technology. The current reused architecture is adapted to reduce the consumed current, while the supply voltage is set to 0.6 V to meet the low voltage requirement as well. To simplify the bias network designs under low voltage operations, NMOS and PMOS devices are used with three‐stage configuration to enhance the gain performance. The measured results of the designed LNA show 17.7 dB in gain and 3.9 dB in noise figure with 0.86 mW of power consumption. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2849–2852, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27214
Microwave oscillator design using folded T‐type slot resonator for X‐band applications
Authors: Shrestha Bhanu , Krishna Maharjan Ram , Kim Nam‐Young 
Published: September 2012

AbstractIn this article, Microwave oscillator was designed, fabricated, and characterized using the folded T‐type slot resonator for X‐band applications. The miniaturized resonator was designed by terminating the slot lines at both ends of the T‐structure. The simulation and experimental results were compared and found a closed agreement between them. The oscillator using the folded T‐type slot resonator showed phase noise performances of −105.54 dBc/Hz at a 100 kHz offset from the carrier frequency of 8.5 GHz with an output power of 14.06 dBm. The oscillator exhibited better phase noise characteristic due to the high unloaded Q value of the folded T‐type slot resonator, which is considerably higher than that of miniaturized spurline resonators. The figure of merit of the oscillator achieved a −183.34 dBc/Hz. The feasibility of integrating that slot resonator in various monolithic microwave integrated circuit technologies can also be expected. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2817–2821, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27215
A simple and efficient finite difference frequency domain method for the analysis and design of leaky‐wave antennas
Authors: Xu Feng 
Published: September 2012

AbstractThe finite difference frequency domain method for the analysis of periodic structures will lead to a large‐scale nonsymmetrical generalized eigenvalue problem, especially when the open periodic structures are analyzed.In this article, the method is greatly simplified, because the large‐scale sparse matrix technique and the shift‐and‐invert Arnoldi technique, which must be applied to significantly reduce the memory need and increase simulation speed, are implemented by means of some existed codes, for example, matlab codes. Besides, the difference equations of this method are much simpler than those of the previous method, because the longitudinal field components do not have to be eliminated to approximately transform the generalized eigenvalue problem to a standard eigenvalue problem. As a result, the method proposed here is quite simple and efficient for the analysis of leaky‐wave antenna, because a leaky‐wave antenna can be regarded as direct geometrical evolution from a guided‐wave structure that permits to leak energy along its longitudinal direction. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2814–2817, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27216
Dual‐band/dual‐polarized microstrip patch antenna for dual‐band heterodyne retrodirective array
Authors: Jung Dong‐Jin , Hansen Jonathan N. , Chang Kai 
Published: September 2012

AbstractThis article presents a dual‐band/dual‐polarized microstrip patch antenna.For a dual‐band retrodirective array system, the dual‐band/dual‐polarized microstrip patch antenna operating at 11 and 12.2 GHz is designed and tested. The antenna consists of one rectangular microstrip patch and a square ring outside of the patch. Two different feeding locations are used for vertical and horizontal polarizations. The vertical polarization is used for a receiving mode and the horizontal polarization for a transmitting mode. The antenna shows a measured gain of 5.2 and 6.8 dBi at 10.9 and 12.2 GHz. The isolation between the two feeding ports is measured to be greater than 15 dB at each center frequency. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2781–2784, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27217
Patterns of Interobserver Error in the Scoring of Entheseal Changes
Authors: Davis C. B. , Shuler K. A. , Danforth M. E. , Herndon K. E. 
Published: September 2012

ABSTRACTAlthough the interpretation of entheses has undergone considerable discussion recently, the role of interobserver error, especially in comparative contexts, has been only sporadically addressed. Using standards developed by Hawkey and Merbs, currently the most widely used system, rates of reproducibility were evaluated in two prehistoric North American skeletal series. Eight observers of varying experience levels scored 17 long bone entheses, representing both fibrous and fibrocartilaginous attachment types, on 58 individuals. Results showed rates of reproducibility to be only marginally higher than what would be expected by chance alone.Observer experience level did not appear to be a factor nor was attachment type. As might be predicted, those entheses enjoying the highest rates of reproducibility exhibited relatively smooth attachment morphology and/or less defined boundaries whereas those with the lowest rates displayed the greatest range of surface morphology expression. Possible explanations for the levels of interobserver error observed include difficulties in reducing the highly variable enthesis morphology to a few discrete categories, categories that encompass too many criteria, and use of vague terminology in describing morphological features. Consequently, comparison of data across studies by different observers, especially those not trained by the developer of a given scoring method, must be undertaken with great caution. Copyright © 2012 John Wiley & Sons, Ltd.
Optimal cut‐offs for down syndrome contingent screening in a population of 10 156 pregnant women
Authors: Guanciali‐Franchi Paolo , Iezzi Irene , Soranno Alessandra , de Volo Chiara Palka‐Bayard , Alfonsi Melissa , Calabrese Giuseppe , Benn Peter 
Published: September 2012

ABSTRACTStudy designA population of 10 156 pregnant women with singleton pregnancies were screened by the integrated test. Risks were retrospectively recalculated for contingent test strategies with first step intermediate risk groups defined by first trimester upper cut‐offs of 1 : 10, 1 : 30, 1 : 50, and 1 : 70 and lower cut‐offs 1 : 1500, 1 : 1200, 1 : 1100, and 1 : 900. The second trimester high risk group was based on a single cut‐off of 1 : 250.ResultsIn the first trimester, the detection rate (DR) ranged from 21% (6/29) to 52% (15/29) as the high risk first trimester cut‐off was changed from 1 : 10 to 1 : 70. The corresponding first trimester false positive rate (FPR) increased from 0.2% to 1.4%. In the second trimester, an additional 21/29 (72%) to 12/29 (41%) affected pregnancies could be detected with an additional 1.6% to 2.7% false positives when lower first trimester cut‐offs of 1 : 900 to 1 : 1500 were used. The best results were obtained with the upper first trimester cut‐off of 1 : 30 and lower first trimester cut‐off of 1 : 900, which yielded a rate of women requiring a second trimester test of only 12%, with overall DR and FPR of 93% and 2.8%, respectively.ConclusionsAlthough the study population was relatively small, the results confirm the advantage of using contingent screening and suggest optimal first trimester cut‐offs of 1 : 30 (lower cut‐off) and 1 : 900 (upper cut‐off). © 2012 John Wiley & Sons, Ltd.
Early second trimester maternal plasma levels of thrombin‐inhibitor complexes and subsequent spontaneous preterm delivery
Authors: Lee Da Eun , Park So Yeon , Choi June Seek , Kim Shin Young , Lim Ji Hyae , Yang Jae Hyug , Ryu Hyun Mee 
Published: September 2012

ABSTRACTObjectiveIncreased thrombin generation has been implicated as a mechanism for several obstetric syndromes including preterm birth preceded by preterm labor (PTL) and preterm premature rupture of membranes (PPROM). In this study, we attempted to determine whether PTL or PPROM are associated with changes in the maternal plasma thrombin level during the early second trimester.MethodsThis is a case–control study in which maternal thrombin–antithrombin (TAT) III complex concentrations at 15–21 weeks were compared between normal controls (n = 85) and women subsequently delivering preterm, due to either PTL with intact membranes (n = 21) or PPROM (n = 20). Statistical analysis was conducted using non‐parametric statistics.ResultsPTL patients with intact membranes showed non‐significant differences in median plasma TAT level (110.1 µg/L) compared with the control group (107.9 µg/L). Similarly, women destined to deliver preterm because of PPROM had non‐significantly higher plasma TAT level (134.3 µg/L) than those in the control group (107.9 µg/L) (p > 0.05). Logistic regression analysis demonstrated that after controlling for confounders including vaginal bleeding, TAT levels remained not significantly associated with subsequent spontaneous preterm birth (p = 0.27).ConclusionMaternal plasma TAT level is unsuitable as an early second trimester predictor of preterm birth preceded by PTL or PPROM. © 2012 John Wiley & Sons, Ltd.
Tuning exchange bias through zero field cooling from different remanent states above blocking temperature in Ni50Mn36Sb14 alloy
Authors: Wang R. L. , Xu L. S. , Sun Z. G. , Marchenkov V. V. , Xiao H. B. , Xu L. F. , Huang J. C. A. , Yang C. P. 
Published: September 2012

AbstractChanging remanent states above blocking temperature (TB) in Ni50Mn36Sb14 alloy has been proven to be an effective way of tuning the value and sign of exchange bias (EB) field. The hysteresis loops at 5 K exhibit double shifted shape, indicating that there are two opposite EB signs resulting from an imprint of domain pattern of ferromagnetic (FM) regions into anti‐ferromagetic (AFM) ones during cooling. All the results demonstrate that the interfacial spin configuration plays a crucial role on the origin of EB, while the high cooling field not only induces a single FM domain state above TB but also tunes the fractions of FM and AFM interactions through martensitic transition. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structure and cooperativity of the hydrogen bonds in sodium dihydrogen triacetate
Authors: Ahmed Ashour A. , Kühn Oliver , Hilal Rifaat H. , Shibl Mohamed F. 
Published: September 2012

AbstractGeometry and energetics of low energy conformers of sodium dihydrogen triacetate (SDHTA) and its anion are studied using density functional theory (DFT) at the Becke, Lee‐Yang‐Parr hybrid functional (BLYP) and Becke, three‐parameter, Lee‐Yang‐Parr hybrid functional (B3LYP) levels. For both cases, two structures of comparable energy are found, which have different symmetry with respect to the two hydrogen bonds (HBs). DFT‐based Born–Oppenheimer molecular dynamics simulations are performed for SDHTA, which show that both structures are visited at room temperature conditions. The trajectory analysis further reveals that the two HBs behave anticooperative, that is, on average elongation of one HB is accompanied by a compression of the other one. This is in accord with nuclear magnetic resonance (NMR) experimental studies for a similar counter ion–dihydrogen triacetate complex. © 2012 Wiley Periodicals, Inc.
Electrospray ionization and collision‐induced dissociation tandem mass spectrometric discrimination of polyphenolic glycosides: exact acylation site determination of the O‐acylated monosaccharide residues
Authors: Liao Shang‐Gao , Zhang Li‐Juan , Wang Zhen , Sun Fa , Li Yong‐Jun , Wang Ai‐Min , Huang Yong , Lan Yan‐Yu , Wang Yong‐Lin 
Published: September 2012

RATIONALEAcylated monosaccharide residues are structural subunits of natural products or synthetic intermediates that have received much attention in past years. Determination of the acylation sites of these residues still relies heavily on the comparison of their characteristic NMR signals with those of known standards and synthesized acylated glycosides. It is important to develop a rapid analytical method for determining the acylation sites for these compounds, and this is described in this study.METHODSSix known polyphenolic glycosides were used for the electrospray ionization and collision‐induced dissociation tandem mass spectrometry (ESI‐CID‐MS/MS) discrimination of the acylated monosaccharide residues with different acylation sites. A combination of ESI‐CID‐MS/MS, using a triple quadrupole mass spectrometer, with ultra‐performance liquid chromatography (UPLC) and photo‐diode array (PDA) detection (UPLC‐PDA) has been applied to the identification or characterization of polyphenolic glycosides in Polygonum capitatum that possess an acylated monosaccharide residue.RESULTSAn ESI‐MS and CID‐MS/MS method has been developed for the determination of the acylation sites of polyphenolic glycosides that possess an acylated monosaccharide residue. Twelve polyphenolic glycosides including four new ones have been identified or characterized in P. capitatum. Eight (including the new ones) of the twelve glycosides were reported for the first time from this plant.CONCLUSIONSThe developed ESI‐MS and CID‐MS/MS method provided a very useful strategy for the determination of the sites of polyphenolic glycosides that possess an acylated monosaccharide residue. The acylation site could be determined by the characteristic product ion spectra of the in‐source CID‐generated O‐acyl monosaccharide ion [B1]+. The presented work may facilitate the structural characterization of these types of compounds. Copyright © 2012 John Wiley & Sons, Ltd.
Extraction and analysis of carnitine and acylcarnitines by electrospray ionization tandem mass spectrometry directly from dried blood and plasma spots using a novel autosampler
Authors: Will Thompson J. , Zhang Haoyue , Smith Peter , Hillman Steven , Arthur Moseley M. , Millington David S. 
Published: September 2012

RATIONALEAcylcarnitines are routinely analyzed by electrospray ionization tandem mass spectrometry (ESI‐MS/MS) both in clinical diagnostic and public health newborn screening laboratories from plasma and dried whole blood spots (DBS) on filter paper. The use of DBS as a convenient method of collecting and storing samples for subsequent analysis of various biomolecules is increasing, thus prompting the development of new devices to recover and quantify such analytes in an automated manner.METHODSAcylcarnitines were extracted directly from DBS using a novel autosampler that sequentially loads DBS cards into a pneumatic clamp and then pumps a fixed volume of solvent containing appropriate internal standards through a section of the DBS card directly into a triple quadrupole mass spectrometer via ESI. Plasma was first spiked with internal standard then spotted onto filter paper for analysis.RESULTSAcylcarnitines were analyzed in DBS, and both free and total carnitine were assayed in dried plasma spots (DPS). Results using the new autosampling technique were of equal quality to those obtained by punching a 3‐mm diameter disk from a DBS or DPS, then extracting and analyzing the target analytes from conventional 96‐well microtiter plates, with far reduced time per sample. Recovery for most analytes was >60% and reproducibility was generally within 20% (CV).CONCLUSIONSThe simplicity and robustness of the DBS autosampler make it an attractive alternative to conventional methods of analyzing DBS specimens, thus saving time and labor costs, especially in high‐throughput applications. Although the method as described is for direct infusion analysis, the autosampler is easily coupled to column hardware for applications requiring liquid chromatography/mass spectrometry (LC/MS). Copyright © 2012 John Wiley & Sons, Ltd.
An experimental and theoretical study on fragmentation of protonated N‐(2‐pyridinylmethyl)indole in electrospray ionization mass spectrometry
Authors: You Zhushuang , Guo Cheng , Pan Yuanjiang 
Published: September 2012

RATIONALEThe dissociation reactions of protonated molecules are the base of structural analysis in electrospray ionization tandem mass spectrometry (ESI‐MSn). However, general rules for elucidating the numerous fragmentation reactions in ESI‐MSn are still rather lacking. Therefore, it is very important at all times to carry out mechanistic investigations for fragmentation reactions in the gas phase.METHODSThe fragmentation reactions of protonated N‐(2‐pyridinylmethyl)indoles were studied by both of ESI ion trap tandem mass spectrometry and ESI Fourier transform ion cyclotron resonance tandem mass spectrometry in positive‐ion mode.RESULTSIn ESI‐MS/MS, the ionizing proton is first bound to the most thermodynamically favored site, the pyridine nitrogen; then it transfers to the dissociative protonation sites and triggers the fragmentation. In the fragmentation of the target compounds, some interesting reactions, such as rearrangement, proton transfer and electron transfer reactions, take place via ion/neutral complexes. The proposed mechanisms are supported by both theoretical calculations and isotopic labeling experiments.CONCLUSIONSThis study is a case for better understanding the dissociative protonation sites and enriching the knowledge about the role of ion/neutral complexes in ESI‐MS. It also provides useful information for the structural analysis of organic compounds, especially drug analysis in pharmaceutical chemistry. Copyright © 2012 John Wiley & Sons, Ltd.
Extension of the focusable mass range in distance‐of‐flight mass spectrometry with multiple detectors
Authors: Gundlach‐Graham Alexander W. , Dennis Elise A. , Ray Steven J. , Enke Christie G. , Carado Anthony J. , Barinaga Charles J. , Koppenaal David W. , Hieftje Gary M. 
Published: September 2012

RATIONALEDistance‐of‐flight mass spectrometry (DOFMS) is a velocity‐based mass separation technique in which ions are spread across a spatially selective detector according to m/z. In this work, we investigate the practical mass range available for DOFMS with a finite‐length detector.METHODSA glow‐discharge DOFMS instrument has been constructed for the analysis of atomic ions. This instrument was modified to accommodate two spatially selective ion detectors, arranged co‐linearly, along the mass‐separation axis of the analyzer. With this geometry, each detector covers a different portion of the distance‐of‐flight spectrum and ions are detected simultaneously at the two detectors. The total flight distance covered by the two detectors is 106 mm and simulates DOF detection across a broad mass range.RESULTSDOFMS theory predicts that ions of all m/z values are focused at a single flight time, but at m/z‐dependent flight distances. Therefore, ions that are detected across a wide portion of the DOF axis should all yield the same peak widths. With a focal‐plane camera detector and a micro‐channel plate/phosphor‐screen detection assembly, we found simultaneous, uniform focus of 40Ar2+ and of 65Cu+ and 63Cu+ with the ions spread 82 mm across the DOF axis. This detection length, combined with the current instrument geometry, allows for a simultaneously detectable m/z value of 4:3 (high mass‐to‐low mass).CONCLUSIONSThese results are the first experimental verification that constant‐momentum acceleration (CMA)‐DOFMS provides energy focus across an extended detection length. Evidence presented demonstrates that DOFMS is amenable to detection with (at least) a 100‐mm detector surface. These results indicate that DOFMS is well suited for detection of broader mass ranges. Copyright © 2012 John Wiley & Sons, Ltd.
UFLE: a user‐friendly location‐free encryption system for mobile users
Authors: He Yi‐Jun , Chan Patrick P. F. , Hui Lucas C. K. , Yiu S. M. 
Published: September 2012

ABSTRACTLeakage of sensitive data stored on lost or stolen portable devices has been an open problem in the data security community. Clumsiness of existing solutions hinders them from being deployed. We propose a user‐friendly location‐free encryption system for mobile users (UFLE) to improve the solution Mobile User Location‐specific Encryption (MULE) from Studer and Perrig on both the security and usability. In particular, we solve the problem of (i) enhancing the convenience and security of MULE, (ii) accessing sensitive data in untrusted locations, and (iii) protecting data on stolen or lost USB flash drive, which were not addressed in their solution. Moreover, UFLE does not require any special hardware except a mobile phone and a Bluetooth adapter, which are readily available nowadays. This significantly improves the practicability of the proposed system in contexts such as business companies, government offices, hospitals, and banks. Evaluation of our system shows that it is both faster and more stable than MULE. Copyright © 2012 John Wiley & Sons, Ltd.
Urine collection systems: the need for change
Authors: Feneley Roger 
Published: September 2012

AbstractThe self‐retaining catheter was developed in the 1930s without recognising the need to preserve the antibacterial mechanisms of the bladder. Professor Feneley discusses how future research should be seeking a urine collection system that enables the bladder to fill and empty regularly and completely, thus mimicking the wash‐out effect of the healthy bladder. He provides an example of the way in which new technologies can improve the quality of life for the catheter user. Copyright © 2012 John Wiley & Sons
Energy awareness workflow model for wireless sensor nodes
Authors: Zhu Zhenhuan , Olutunde Oyadiji S. , He Hongmei 
Published: September 2012

ABSTRACTBefore the development of a large‐scale wireless sensor network (WSN) infrastructure, it is necessary to create a model to evaluate the lifespan of the infrastructure, the system performance and the cost so that the best design solution can be obtained. Energy consumption is an important factor that influences the lifespan of WSNs. One of the ways to extend the lifespan of WSNs is to design wireless sensor nodes with low power consumption. This involves component selection and the optimisation of hardware architecture, monitoring software system and protocols to satisfy the requirements of the particular applications. This paper proposes a comprehensive model to describe the workflow of a wireless sensor node. Parameter setup and energy consumption calculation are demonstrated through the model simulation. It provides a mathematical approach to dynamically evaluate the energy consumption of a sensor node. This will benefit the development of wireless sensor nodes based on microprocessors with limited computational capability. Therefore, the model can be applied in dynamic power management systems for wireless sensor nodes or in wireless communication protocols with energy awareness, in particular, for WSNs with self‐organisation. More importantly, the generalisation of the model may be employed as a standard paradigm for the development of wireless sensor node with energy awareness. Copyright © 2012 John Wiley & Sons, Ltd.