bluuebunny/crossref_metadata_2025_split huggingface dataset:
[18F]/19F exchange in fluorine containing compounds for potential use in 18F‐labelling strategies
Authors: Blom Elisabeth , Karimi Farhad , Långström Bengt 
Published: August 2009

AbstractExchange of [18F]fluoride with 19F in various organofluorine compounds in concentrations ranging from 0.06 to 56 mM was explored. We aimed to explore whether exchange reactions can be a potential useful labelling strategy, when there are no requirement of high specific radioactivity. Parameters such as solvents, temperature, conventional vs microwave heating, and the degree of fluorine load in some aromatic and alkyl compounds were investigated with regard to radiochemical yield and specific radioactivity. A series of fluorobenzophenones (1–6), 1‐(4‐fluorophenyl)ethanone (7), various activated and deactivated fluoro benzenes (8–16), N‐(pentafluorophenyl)benzamide (17), (pentafluorophenyl)formamide (18), (tridecafluorohexyl)benzene (19) and tetradecafluorohexane (20) were subjected to [18F]/19F exchange. To test this strategy to label biologically active molecules containing fluorine atoms in an aryl group, two analogues of WAY‐100635 (21–22), Lapatinib (23), 2,5,6,7,8‐pentafluoro‐3‐methylnaphthoquinone (24) and 1‐(2,4‐difluorophenyl)‐3‐(4‐fluorophenyl)propan‐1‐one (25) were investigated. The multi‐fluorinated molecules containing an electron‐withdrawing group were successfully labelled at room temperature, whereas the monofluorinated, as well as those containing an electron‐donating group, required heating for the exchange reaction to take place. Copyright © 2009 John Wiley & Sons, Ltd.
Cosmogenic nuclide exposure ages from the ‘Parallel Roads’ of Glen Roy, Scotland
Authors: Fabel Derek , Small David , Miguens‐Rodriguez Maria , Freeman Stewart P. H. T. 
Published: August 2009

AbstractThe ‘Parallel Roads’ of Glen Roy, Scotland, are the shorelines of former ice‐dammed lakes created by the last glaciers to occupy the area. We use surface exposure dating with cosmic ray‐produced 10Be in quartz to provide the first numerical age control on the timing of formation of one of one of these shorelines and depositional features in Glen Roy. Four bedrock samples from the surface of the 325 m ‘Parallel Road’ yielded a mean formation age of ca. 11.5–11.9 ka. This age range confirms the long‐held view that the ‘Parallel Roads’ are Loch Lomond Stadial (ca. 12.9–11.5 ka) features. The age range reflects variation in currently available cosmogenic nuclide scaling schemes and the related 10Be production rates. Two samples from the surface of the Turret fan indicate that the 260 m lake drained before ca. 10.7–11.0 ka, while two samples from the Brunachan fan suggest that subaerial sedimentation occurred after ca. 9.7–9.9 ka. Copyright © 2009 John Wiley & Sons, Ltd.
Tip‐enhanced Raman spectroscopy for investigating adsorbed nonresonant molecules on single‐crystal surfaces: tip regeneration, probe molecule, and enhancement effect
Authors: Liu Zheng , Wang Xiang , Dai Ke , Jin Shan , Zeng Zhi‐Cong , Zhuang Mu‐De , Yang Zhi‐Lin , Wu De‐Yin , Ren Bin , Tian Zhong‐Qun 
Published: August 2009

AbstractTip, substrate, molecular species, and laser are the four main factors determining the detection sensitivity and spatial resolution of tip‐enhanced Raman spectroscopy (TERS). In this paper, we deal with the tip and molecular species. We will first introduce a simple method to regenerate Au tips fabricated by electrochemical etching for TERS to ensure good experimental reproducibility. Some criteria are proposed to choose molecular species as the probe molecules for reliable TERS investigation of the surface processes and TERS mechanism after a comparison of the TERS and SERS signal of benzenedithiol and 4,4′‐bipyridine. Then, high‐quality TERS signals of a series of molecules of oligo(phenylene ethynylene)s (OPEs) of different lengths adsorbed on a Au(111) single crystal surface are demonstrated. The possible explanation assisted by finite‐difference time‐domain (FDTD) simulation and quantum chemical calculation is used to understand the molecular length‐dependent change of the TERS signal. The potential application of TERS for studying systems related to molecular electronics is proposed. Finally, a method is proposed to calculate the tip enhancement for the nonresonant surface species in TERS. Copyright © 2009 John Wiley & Sons, Ltd.
Perfusion in hamster skin treated with glycerol
Authors: Zaman Raiyan T. , Parthasarathy Ashwin B. , Vargas Gracie , Chen Bo , Dunn Andrew K. , Rylander Henry G. , Welch Ashley J. 
Published: August 2009

AbstractBackground and ObjectiveThe objective of this article is to quantify the effect of hyper‐osmotic agent (glycerol) on blood velocity in hamster skin blood vessels measured with a dynamic imaging technique, laser speckle contrast imaging (LSCI).Study Design/Materials and MethodsIn this study a dorsal skin‐flap window was implanted on the hamster skin. The hyper‐osmotic drug, that is, glycerol was delivered to the skin through the open dermal end of the window model. A two‐dimensional map of blood flow of skin blood vessels was obtained from the speckle contrast (SC) images.ResultsPreliminary studies demonstrated that hyper‐osmotic agents such as glycerol not only make tissue temporarily transparent, but also reduce blood flow. The blood perfusion was measured every 3 minutes for 36–66 minutes after diffusion of anhydrous glycerol. Blood flow in small capillaries was found to be reduced significantly within 3–9 minutes. Blood flow in larger blood vessels (i.e., all arteries and veins) decreased over time and some veins had significantly reduced blood flow within 36 minutes. At 24 hours, there was a further reduction in capillary blood perfusion whereas larger blood vessels regained flow compared to an hour after initial application of glycerol.ConclusionBlood flow velocity and vessel diameter of the micro‐vasculatures of hamster skin were reduced by the application of 100% anhydrous glycerol. At 24 hours, capillary perfusion remained depressed. Lasers Surg. Med. 41:492–503, 2009. © 2009 Wiley‐Liss, Inc.
Application of a rat‐race coupler in low‐cost load and source pull transistor amplifier design
Authors: Gruszczyński Slawomir , Wincza Krzysztof , Borgosz Jan 
Published: August 2009

AbstractA method for load and source pull is proposed in which rat‐race couplers with sections of shorted transmission lines are used. It is shown that the connection of a rat‐race coupler with two shorted transmission lines allows for realization of any desired impedance, thus, allowing for effective transistor matching and, therefore, achieving maximum output power. Both theoretical analysis and experimental results are presented showing usefulness of the proposed technique. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2537–2541, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24668
Polymeric ferrite‐loaded antennas for on‐body communications
Authors: Alves T. , Augustine R. , Quéffélec P. , Grzeskowiak M. , Poussot B. , Laheurte J.‐M. 
Published: August 2009

AbstractWearable antennas are integral part of body area networks (BANs). Antenna design for BAN applications is a challenging task since the antennas have to be small, efficient, and must not be affected by the wearer's body. This makes isolation of antenna a matter of importance. Ferrites form an opaque media for microwave at the 2.4‐GHz ISM band and hence it could be used for the isolation of antenna from surroundings. Thin polymeric ferrite sheets are used to reduce body influence in BAN perspective. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2530–2533, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24669
Hex‐band antenna for slim handheld device applications
Authors: Ali Shirook M. , Kanj Houssam 
Published: August 2009

AbstractIn this article, we present an approach and design of a small antenna for slim handheld device applications. The basic antenna element is the monopole. The small size and the reduced effective antenna height are achieved from two folding approaches of this monopole. The first is in a three‐dimensional manner, which also results in a broad bandwidth at the desired operating frequencies. The second is achieved by wrapping the antenna around the PCB. This wrapping reduces the physical antenna height to the minimum height required to accommodate the main components of the device without compromising the antenna performance. The proposed antenna is prototyped and modeled, where its performance is examined through simulations and measurements. The antenna supports six frequency bands, GSM 800/900/1800/1900 MHz, UMTS 2100 MHz, and Bluetooth 2400 MHz. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2527–2530, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24670
Dual‐band N‐shaped patch antenna loaded by lumped elements
Authors: Moustafa Asmaa H. , Abdallah Esmat A. , Hashish Essam A. 
Published: August 2009

AbstractThis article presents a dual‐band circular N‐shaped microstrip patch antenna loaded by a shorting pin and lumped R‐C circuit, hence a resonant R‐L‐C circuit is introduced. Loading by shorting pin excites the zero fundamental mode of the circular patch antenna (TM010), and it shifts the first fundamental mode (TM110) to higher one. N‐shaped microstrip patch antenna is used as a modified circular microstrip patch antenna with reduced size. The proposed antenna is designed and fabricated on two‐layered substrate. A comprehensive parametric study has been carried out on values of R and C to optimize the antenna performance. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2534–2537, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24673
Compact angularly stable frequency selective surface using hexagonal fractal configurations
Authors: Wang Wentao T. , Zhang P. F. , Gong S. X. , Lu B. , Ling J. , Wan Tingting T. 
Published: August 2009

AbstractA compact bandstop frequency selective surface (FSS) using fractal structure is proposed. This flexuous design elongates the cell perimeter of the ring‐shaped FSS, which means the cell size gets smaller at the same resonance frequency. Furthermore, the unit cells adopt regular hexagon and the array employs equilateral triangle form. Because of its symmetric configuration, good frequency stability has been achieved for both horizontal and vertical polarizations at different oblique angles. For the stable bandstop character, this FSS can be used for protecting the staff of S‐band radars against electromagnetic radiation, while the 900/1800/1900 MHz mobile bands and the 5.2/5.8 GHz wireless local area network signals are not affected. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2541–2544, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24676
Dual‐broadband printed monopole antenna with a numeral‐7 slit
Authors: Yang Chao‐Shun , Sze Jia‐Yi , Tu Po‐Jen 
Published: August 2009

AbstractA 15‐by‐20‐mm2 dual‐broadband printed monopole antenna fed by a coplanar waveguide is presented. With a numeral‐7 slit etched from the rectangular radiating element, the antenna can excite for its lower and upper impedance bands two and one resonant modes, respectively. With a back‐patch appropriately printed on the other side of the substrate, a lower (upper) impedance band with a bandwidth of 39.3% (19.5%) can be obtained. These two impedance bands can cover the frequency bands required by UMTS/IMT‐2000/IEEE802.11a/b/g/WiMAX. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2544–2547, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24677
Precise frequency and bandwidth control of microstrip switchable bandstop filters
Authors: Brito‐Brito Zabdiel , Llamas‐Garro Ignacio , Pradell Lluis 
Published: August 2009

AbstractIn this article two switchable bandstop filters able to switch precisely between two different center frequency and bandwidth states are presented. The filter topologies allow precise control over the design parameters frequency and bandwidth, achieved by choosing adequate resonator sections switched by PIN diodes. Center frequency control was obtained by modifying resonator length. Bandwidth control was achieved by choosing a resonator width and controlling the normalized reactance slope parameter of the decoupling resonators by means of switchable resonator extensions. Both filters were designed to have a 32.5% center frequency tuning range at L band between a low and high filter center frequency. One topology focuses on producing an 8% fractional stopband bandwidth for both filter states. The second filter topology focuses on producing 7 and 9% fractional stopband bandwidths for the low and high filter center frequency states, respectively. Measured results show a very good agreement with the simulations, for the first topology a 32.2% measured center frequency tuning range was obtained with 8.1 and 8.75% fractional stopband bandwidths for the low and high filter center frequency states, respectively. The second filter topology showed a 31.2% measured center frequency tuning range with 6.94 and 9.66% fractional stopband bandwidths for the low and high filter center frequency states, respectively. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2573–2578, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24679
A novel compact bandpass filter using a novel microstrip three‐mode resonator obtaining low loss and sharp attenuation
Authors: He Wenqing , Ma Zhewang , Chen Chun‐Ping , Anada Tetsuo 
Published: August 2009

AbstractA novel compact ultra‐wideband bandpass filter is designed by using a microstrip three‐mode resonator. The three‐mode resonator is configured by adding a short‐circuited stub and an open stub to a half‐wavelength resonator, and its first three modes are designed to cover a very wide passband. The resonator is fed by parallel‐coupled quarter‐wavelength lines. As a consequence, five reflection zeros are obtained in the passband covering ∼3.4–10.1 GHz. As the filter consists of only one resonator, it is very small and low loss, with measured insertion loss better than 0.6 dB in the passband. The group delay is very flat over the passband, and is about 0.5 ns at the center frequency. Moreover, the filter has multiple transmission zeros near its passband, and exhibits thereby sharp skirt property. The minimum strip‐width and gap‐width in the filter is 0.2 mm and 0.1 mm, respectively, and no complicated backside‐aperture‐fabrication process is required. So the filter can be fabricated easily at low cost. The measured frequency response of the filter agrees favorably with the predicted one, and the Federal Communications Commissions indoor limit is satisfied well. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2547–2551, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24681
A fully integrated CMOS power amplifier with a half‐turn transformer for IEEE 802.11a WLAN applications
Authors: Baek Sang‐Hyun , Hong Songcheol 
Published: August 2009

AbstractA fully integrated CMOS power amplifier for 5 GHz WLAN applications is implemented using 0.18 μm CMOS technology. An on‐chip transmission‐line transformer is used for output matching and voltage combining. An input balun, interstage matching components, an output transmission‐line transformer, and RF chokes are fully integrated in the amplifier, and thus no external components are required. The power amplifier occupies a total area of 1.7 mm × 1.2 mm. At a 3.3 V supply voltage, the amplifier exhibits a 22.6 dBm output 1 dB compression point, 23.8 dBm saturated output power, and 25 dB power gain. The power added efficiency (PAE) is 21% at maximum, 19% at P1dB. When a 54 Mbps/64 QAM OFDM signal is applied, the PA delivers an average power of 12 dBm at an EVM of −25 dB. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2551–2553, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24683
Discretely tunable fiber ring laser using FBG tunable filter and Mach‐Zehnder interferometer
Authors: Chen Wei , Hua Zhu Ning , Wei Man Jiang , Xiong Shang , Xie Liang 
Published: August 2009

AbstractA discretely tunable Er‐doped fiber‐ring laser using a fiber Mach‐Zehnder interferometer (MZI) and a tunable fiber Bragg grating (FBG) is proposed. In this scheme, the combination of MZI and FBG acts as a discrete wavelength selector. Analysis of its transmission function shows that discrete wavelength tuning can be realized, and experiments demonstrate 64 single‐mode outputs with a mode spacing of 181.7 pm, and the output power is quite stable in the whole tuning range. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2595–2598, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24690
Triangular planar array of a pyramidal adaptive antenna for satellite communications at 1.7 GHz
Authors: Masa‐Campos J. L. , Montesinos‐Ortego I. , Sierra‐Pérez M. 
Published: August 2009

AbstractNowadays, satellite communications are basic for the human lifestyle. In this way, a smart, conformal, and multiarray antenna (GEODA) is being developed in order to receive signals from several satellites simultaneously in the 1.7 GHz working band. An adaptive beam system is able to follow the signals from the satellite constellation. The complex structure of the antenna is based in a 3D composition of planar arrays with triangular shape. These arrays are divided into subarrays of three patches (Cells), composing the single control element for the arrays main beam direction management. Fifteen cells (45 radiating elements) compose each triangular array of the GEODA antenna. In this article, a triangular array prototype is implemented and measured. Likewise, an individual characterization of the array components is presented. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2633–2639, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24692
A compact ultrawideband antenna design based on the current distribution
Authors: Yang Ying‐Ying , Zheng Zhi‐An , Chu Qing‐Xin 
Published: August 2009

AbstractIn this letter, a design of a compact ultrawideband (UWB) antenna is presented, which is based on the current distribution of the previously proposed UWB antenna. The portions with little current distribution are cut from the antenna with less effect on the antenna performance. The modified compact UWB antenna yields an impedance bandwidth of 3.0–50.0 GHz with return loss less than −10 dB. The antenna is successfully simulated, designed, and measured showing extremely broadband matched impedance, stable gain and omni‐directional radiation patterns. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2601–2603, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24695
An efficient evaluation of the Green's functions for periodic structures in multilayered media
Authors: Zhuang W. , Chen R. S. , Ding D. Z. 
Published: August 2009

AbstractAn efficient scheme is presented to calculate the periodic structure in planar multilayered media. The slowly converging series for the periodic Green's function is accelerated using the Ewald's method combined with Shank transformation and the computational time is significantly reduced compared with the direct spectral summation. Numerical examples are given to demonstrate the efficiency of the proposed method. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2639–2643, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24696
Compact circularly polarized omnidirectional microstrip antenna
Authors: An Jian , Wang Guang‐Ming , Zhang Chen‐Xin , Zeng Hui‐Yong 
Published: August 2009

AbstractA new type of circularly polarized omnidirectional microstrip antenna employing zeroth‐order resonator loaded with stubs along the ground perimeter is presented. The proposed antenna has the conceptual configuration of the horizontal magnetic and electric loop currents which act as the electric and magnetic monopole antennas, respectively. By adjusting the relevant dimensions of the loaded stubs, circularly polarized omnidirectional operation can be realized. The proposed antenna operates at 1.55 GHz and provides a 10 dB input return loss bandwidth of 1.3%. The whole dimensions of the proposed antenna are about λ/6×λ/6×λ/96 in terms of vacuum wavelength. The simulated and measured radiation patterns show the proposed antenna radiates electromagnetic wave omnidirectionally. The simulated axial ratio of the proposed antenna indicates it has good circular polarization performance. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2643–2646, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24697
Performance and capacity analysis of 60 GHz WPAN channel
Authors: Geng Suiyan 
Published: August 2009

AbstractIn this work, the performance and capacity of both 60 GHz ultrawide‐band (UWB) and multiple‐in multiple‐out (MIMO) channels are analyzed based on experimental channel models and specifications for millimeter‐wave wireless personal area networks (WPANs). In the analysis of 60 GHz UWB channel, the radio link budget is estimated by applying two experimental channel models where blocking effect is considered and fading margin (FM) is modeled as a function of channel bandwidth. Results show that high gain antennas are required in 60 GHz UWB channel. The high gain antenna systems suffer from poor flexibility and the directional signals can be easily blocked in multipath indoor environments. This indicates that gigabit communications is quite difficult in 60 GHz UWB channel. To overcome this problem, adaptive antenna arrays (or MIMO systems) are required as they can search and direct the available signals to improve radio link budget. The 60‐GHz MIMO channel capacity is analyzed by modeling FM as a function of number of antenna elements. The proposed NLOS channel model is employed in rich scattering or multipath environments for achieving high capacity in MIMO channel. Tests were also performed for determining gigabit data rate, operation range and configuration in the 60‐GHz MIMO case. The goal of this study is to provide useful information for the design of future 60 GHz WPAN systems. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2671–2675, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24698
A single‐feed circularly‐polarized patch antenna for reduced surface wave applications
Authors: Al‐Ajmi Ayed R. , Mahmoud Samir F. 
Published: August 2009

AbstractA circularly polarized (CP) microstrip patch antenna design with single probe‐feed is proposed for reduced surface waves applications. The circular polarization is achieved by embedding a narrow slot at the center of a circular patch with an intersecting angle of 45 degrees relative to the feed position. Simulation results using the IE3D software facility have shown the capability of achieving circular polarization with high polarization purity while maintaining the reduction of surface waves and lateral waves. The simplicity of the design, together with the circular polarization characteristics and surface wave reduction indicate that this new antenna design is a promising candidate for applications including large patch antenna arrays and high precision GPS receiving antennas. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2675–2679, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24699