bluuebunny/crossref_metadata_2025 huggingface dataset:
How do sediment yields from post‐wildfire debris‐laden flows depend on terrain slope, soil burn severity class, and drainage basin area? Insights from airborne‐LiDAR change detection
Authors: Pelletier Jon D. , Orem Caitlin A.
Published: March 2014

We derived a high‐resolution, spatially continuous map of erosion and deposition associated with the debris‐laden flows triggered by the 2011 Las Conchas wildfire and subsequent rainstorms over a 197 km2 area in New Mexico, USA. This map was produced using airborne‐LiDAR‐derived bare‐earth digital elevation models (DEMs) acquired approximately one year before and one year after the wildfire. Differencing of the pre‐wildfire and post‐wildfire‐and‐rainstorm bare‐earth DEMs yielded a DEM‐of‐difference (DoD) map that quantifies the magnitude of ground‐surface elevation changes due to erosion/deposition within each 1 m2 pixel. We applied a 0.3 m threshold filter to our DoD to remove changes that could have been due to artifacts and/or imperfect georeferencing. The 0.3 m value for the threshold filter was chosen based on the stated accuracy of the LiDAR as well as a comparison of areas of significant topographic change mapped in aerial photographs with those predicted using a range of candidate threshold values for the DoD filter. We developed an automated procedure that accepts the DoD map as input and computes, for every pixel in the DEM, the net sediment volume exported through each pixel by colluvial and/or fluvial processes using a digital routing algorithm. An analysis of the resulting sediment volume map for the Las Conchas fire demonstrates that sediment volume is proportional to upstream contributing area. After normalized by contributing area, the average sediment yield (defined as the sediment volume divided by the contributing area) increases as a power‐law functions of the average terrain slope and soil burn severity class (SBSC) with exponents equal to approximately 1.5. Our analysis quantifies the relationships among sediment yield, average terrain slope, and average soil burn severity class at the watershed scale and should prove useful for predicting the geomorphic response of wildfire‐affected drainage basins. Copyright © 2014 John Wiley & Sons, Ltd.
EFFECT OF SRI WATER MANAGEMENT ON WATER QUALITY AND GREENHOUSE GAS EMISSIONS IN KOREA
Authors: Choi Joongdae , Kim Gunyeob , Park Woonji , Shin Minhwan , Choi Yonghun , Lee Suin , Kim Sunjoo , Yun Dongkoun
Published: March 2014

A feasibility study on the system of rice intensification (SRI) methods with respect to irrigation requirements, non‐point source (NPS) pollution discharge, greenhouse gas (GHG) emissions and rice yields was conducted for either 2 or 3 years depending on the treatment in Korea. Large‐size runoff plots were prepared, and the necessary measuring systems installed. The SRI methods were carried out with a Japonica variety of rice, Odaebyeo (Oryza sativa L.), and the results were compared with those for control plots. The data indicated the high potentiality of adoption of the SRI methods for paddy farming in Korea. The SRI methods (i.e. SRI and conventional practice with SRI water management (CS)) reduced the irrigation requirement by 50.2 and 46.0%, respectively. For the SRI and CS plots, averaged concentration reductions of typical NPS pollutants, relative to conventional practice (CT) plots, ranged between 15.3 and 42.6%. The GHG emissions from the conventional practice with two forced drainages (CD) and the CS plots, in terms of their CO2 equivalents, were reduced by 65.5 and 72.8%, respectively, compared with those from the CT plots. The rice yields from the SRI and the CS plots were not greater than those from the CT plots. Application of SRI water management methods could help to improve Korea's water resources and water quality management, and could thus contribute to mitigation of the negative effects of global warming. Copyright © 2014 John Wiley & Sons, Ltd.
Influence of sun exposure on the cutaneous collagen/elastin fibers and carotenoids: negative effects can be reduced by application of sunscreen
Authors: Darvin Maxim E. , Richter Heike , Ahlberg Sebastian , Haag Stefan F. , Meinke Martina C. , Le Quintrec Delphine , Doucet Olivier , Lademann Jürgen
Published: March 2014

Resonance Raman spectroscopy and multi‐photon tomography were used in vivo to analyse the influence of sun exposure on the cutaneous carotenoids and collagen/elastin fibers. Comparing Berlin (low sun exposure) and Monegasque (high sun exposure) volunteers, it could be demonstrated that extended sun exposure significantly reduces the cutaneous carotenoids and collagen/elastin concentration (p < 0.05). The tendency towards correlation (R2 = 0.41) between the dermal collagen/elastin (SAAID) and carotenoids confirms the important role of antioxidants in the protection against sun‐induced negative effects. The application of sunscreen was shown to be effective, protecting cutaneous carotenoids and collagen/elastin from being damaged subsequent to sun exposure. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Alterations of Bone Density, Microstructure, and Strength of the Distal Radius in Male Patients With Rheumatoid Arthritis: A Case-Control Study With HR-pQCT
Authors: Zhu Tracy Y , Griffith James F , Qin Ling , Hung Vivian W , Fong Tsz-Ning , Au Sze-Ki , Li Martin , Lam Yvonne Yi-On , Wong Chun-Kwok , Kwok Anthony W , Leung Ping-Chung , Li Edmund K , Tam Lai-Shan
Published: March 2014

In this cross-sectional study, we investigated volumetric bone mineral density (vBMD), bone microstructure, and biomechanical competence of the distal radius in male patients with rheumatoid arthritis (RA). The study cohort comprised 50 male RA patients of average age of 61.1 years and 50 age-matched healthy males. Areal BMD (aBMD) of the hip, lumbar spine, and distal radius was measured by dual-energy X-ray absorptiometry. High-resolution peripheral quantitative computed tomography (HR-pQCT) of the distal radius provided measures of cortical and trabecular vBMD, microstructure, and biomechanical indices. aBMD of the hip but not the lumbar spine or ultradistal radius was significantly lower in RA patients than controls after adjustment for body weight. Total, cortical, and trabecular vBMD at the distal radius were, on average, –3.9% to –23.2% significantly lower in RA patients, and these differences were not affected by adjustment for body weight, testosterone level, or aBMD at the ultradistal radius. Trabecular microstructure indices were, on average, –8.1% (trabecular number) to 28.7% (trabecular network inhomogeneity) significantly inferior, whereas cortical pore volume and cortical porosity index were, on average, 80.3% and 63.9%, respectively, significantly higher in RA patients. RA patients also had significantly lower whole-bone stiffness, modulus, and failure load, with lower and more unevenly distributed cortical and trabecular stress. Density and microstructure indices significantly correlated with disease activity, severity, and levels of pro-inflammatory cytokines (interleukin [IL] 12p70, tumor necrosis factor, IL-6 and IL-1β). Ten RA patients had focal periosteal bone apposition most prominent at the ulnovolar aspect of the distal radius. These patients had shorter disease duration and significantly higher cortical porosity. In conclusion, HR-pQCT reveals significant alterations of bone density, microstructure, and strength of the distal radius in male RA patients and provides new insight into the microstructural basis of bone fragility accompanying chronic inflammation. © 2014 American Society for Bone and Mineral Research.
Age-Related Impairment of Bones' Adaptive Response to Loading in Mice Is Associated With Sex-Related Deficiencies in Osteoblasts but No Change in Osteocytes
Authors: Meakin Lee B , Galea Gabriel L , Sugiyama Toshihiro , Lanyon Lance E , Price Joanna S
Published: March 2014

Bones adjust their mass and architecture to be sufficiently robust to withstand functional loading by adapting to their strain environment. This mechanism appears less effective with age, resulting in low bone mass. In male and female young adult (17-week-old) and old (19-month-old) mice, we investigated the effect of age in vivo on bones' adaptive response to loading and in vitro in primary cultures of osteoblast-like cells derived from bone cortices. Right tibias were axially loaded on alternate days for 2 weeks. Left tibias were non-loaded controls. In a separate group, the number of sclerostin-positive osteocytes and the number of periosteal osteoblasts were analyzed 24 hours after a single loading episode. The responses to strain of the primary osteoblast-like cells derived from these mice were assessed by EGR2 expression, change in cell number and Ki67 immunofluorescence. In young male and female mice, loading increased trabecular thickness and the number of trabecular connections. Increase in the number of trabecular connections was impaired with age but trabecular thickness was not. In old mice, the loading-related increase in periosteal apposition of the cortex was less than in young ones. Age was associated with a lesser loading-related increase in osteoblast number on the periosteal surface but had no effect on loading-related reduction in the number of sclerostin-positive osteocytes. In vitro, strain-related proliferation of osteoblast-like cells was lower in cells from old than young mice. Cells from aged female mice demonstrated normal entry into the cell cycle but subsequently arrested in G2 phase, reducing strain-related increases in cell number. Thus, in both male and female mice, loading-related adaptive responses are impaired with age. This impairment is different in females and males. The deficit appears to occur in osteoblasts' proliferative responses to strain rather than earlier strain-related responses in the osteocytes. © 2014 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals, Inc. on behalf of the American Society for Bone and Mineral Research.
Role of PUF‐8/PUF Protein in Stem Cell Control, Sperm‐Oocyte Decision and Cell Fate Reprogramming
Authors: Datla Udaya Sree , Scovill Natasha Carol , Brokamp Austin J. , Kim Eunsuk , Asch Adam S. , Lee Myon‐Hee
Published: March 2014

Pumilio and FBF (PUF) proteins are conserved stem cell regulators that maintain germline stem cells (GSCs) in worms and flies. Moreover, they are also present in vertebrate stem cells. The nematode Caenorhabditis elegans has multiple PUF proteins with specialized roles. Among them, PUF‐8 protein controls multiple cellular processes, including proliferation, differentiation, sperm‐oocyte decision, and cell fate reprogramming, depending on the genetic context in the C. elegans germline. In this review, we describe the possible mechanisms of how PUF‐8 protein systematically controls multiple cellular processes in the C. elegans germline. Since PUF proteins are evolutionarily conserved, we suggest that a similar mechanism may be involved in controlling stem cell regulation and differentiation in other organisms, including humans. J. Cell. Physiol. 229: 1306–1311, 2014. © 2014 Wiley Periodicals, Inc.
Capillary surfaces of constant mean curvature in a right solid cylinder
Authors: López Rafael , Pyo Juncheol
Published: March 2014

In this paper we investigate constant mean curvature surfaces with nonempty boundary in Euclidean space that meet a right cylinder at a constant angle along the boundary. If the surface lies inside of the solid cylinder, we obtain some results of symmetry by using the Alexandrov reflection method. When the mean curvature is zero, we give sufficient conditions to conclude that the surface is part of a plane or a catenoid.
Internal slot phase varying in traveling‐wave substrate‐integrated waveguide slot antennas and appropriate modeling
Authors: Peters Florian D. L. , Denidni Tayeb A. , Tatu Serioja O.
Published: March 2014

In this letter, a new alternative configuration of slotted radiating elements in substrate‐integrated waveguide (SIW) is proposed. It yields a greater control over the transmission phase of the slotted waveguide section. This allows a precise conception of traveling‐wave slot antennas in SIW, including those with a high width‐to‐height ratio. Altering the phase by internal measures, instead of displacing slots, is revealed to be very suitable in achieving a good side lobe performance and a broadside beam with less computation effort. For this sake, multiple vias are inserted sophistically in all elements while upholding low reflection and unaffected radiation. A simplified yet bidirectional signal flow graph completes the straightforward approach. Validation is carried out first by comparing slot amplitudes of three different arrays, designed through different procedures, with ideal desired values. Second, fabricated and simulated circuits are evaluated in terms of reflection and radiation performance. The good results demonstrate that this new alternative way to configure a slot antenna in traveling‐wave architecture is a very good candidate in particular for low‐effort applications. A MATLAB test script is provided for further validation and design. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1303–1307, 2014
A tunable photonic microwave notch filter with a negative coefficient using nonlinear behavior of a reflective semiconductor optical amplifier
Authors: Kwon Won‐Bae , Choi Yong‐Kyu , Lee Dongsoo , Kim Geun‐Yong , Park Chang‐Soo
Published: March 2014

We propose and experimentally demonstrate a simple tunable photonic microwave notch filter with positive and negative coefficients. The negative coefficient is obtained from a single input signal (positive coefficient) using cross gain modulation (XGM) in a reflective semiconductor optical amplifier (RSOA). When the RSOA is operated in the saturated region, the signal carried on the pump wavelength is inversely copied to the probe wavelength by the XGM effect, showing a negative coefficient. This probe wavelength is easily generated by self‐injection locking the RSOA through a wavelength‐selective filter. Further, variable time delay for filter tuning is achieved using wavelength‐dependent time delay in a fiber medium by changing the Bragg wavelength of the fiber Bragg grating. The proposed microwave notch filter shows notch dips of more than 33 dB and has a tuning range from 828 to 905 MHz in a free spectral range with a wavelength change of 0.6 nm. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1328–1331, 2014
Single‐feed cross‐slot loaded compact circularly polarized microstrip antenna for indoor WLAN applications
Authors: Kumar Sachin , Kanaujia Binod K. , Sharma Abhishek , Khandelwal Mukesh K. , Gautam A. K.
Published: March 2014

A novel single‐feed circularly polarized microstrip antenna with compact size is proposed for indoor wireless local area network (WLAN) applications. The antenna structure consists of eight slits which are introduced at the boundary and the corners in the radiating square patch with a cross‐slot at the center. The proposed antenna shows a compactness of 42% compared with the conventional circularly polarized antenna design at indoor WLAN frequency band. It is found that the resonance frequency of the proposed structure is highly depending on length and width of cross‐slot and corner slit for entire band of circular polarization. The 3 dB axial ratio bandwidth of the proposed antenna is 1.9%. Proposed structure is fabricated on the FR‐4 epoxy substrate and fed by a single coaxial probe. Measured results show a good agreement with the simulated results. Antenna shows stable radiation characteristics for the entire operating band. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1313–1317, 2014
Comparison of performance of compact ring printed monopole and loop antennas for wireless‐implantable body area network applications
Authors: Ramli Nur Hidayah , Kamarudin Muhammad Ramlee , Ahyat Ezla Najwa , Samsuri Nor Asmawati , Khamis Nor Hisham H. , Abdulrahman A. Y. , Ayob Muhammad Fitri
Published: March 2014

Human bodies have a variety of tissues and organs, and so it needs to be characterized as a radio‐wave propagation medium to create a reliable wireless communication link. The radiation characteristics of printed monopole antenna and printed loop antenna for wireless‐implantable body area network (WiBAN) applications are presented in this article. The two antennas are submerged into canola oil to mimic an implanted antenna in the human tissue. The tissue is considered a lossy environment and hence, it adversely degrades radiation characteristics of both antennas. Therefore, the RF transmission attenuation, dB can be used for characterizing the propagating wave from the submerged antennas to the free‐air surface. The measured results show satisfactory performance and are in good agreement with the simulation. As indicated in the results, the attenuation rate from a lossy environment to the free space for the printed loop antenna (0.1 dB/mm) is smaller compared to that of printed monopole antenna (0.1–0.3 dB/mm). More so, the printed loop antenna is smaller in size (about 56%) compared to the printed monopole antenna, which suggests that the loop antenna is more suitable than the monopole for the WiBAN applications. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1270–1274, 2014
Fiber‐optic sensor without polarization‐induced signal fading
Authors: Yuan Wu , Pang Bian , Bo Jia , Qian Xiao
Published: March 2014

Problems associated with the polarization‐induced signal fading (PSF), produced by the random fluctuation of the polarization states of the two interfering optical waves, are established based on the Jones matrix model of the optical polarization. It is shown that only using Faraday rotating mirrors cannot eliminate the PSF problem. Modifications to have fiber‐optic sensor immune to the PSF are suggested and demonstrated experimentally. It is shown that this new configuration passively eliminated PSF. Theoretical analysis and experimental results in support of this statement are presented. The performance of fiber‐optic sensor is examined and compared with the conventional fiber‐optic sensor. From the results of the experiment, the proposed polarization‐immune fiber‐optic sensor achieves good and stable visibility. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1307–1313, 2014
Wideband L‐probe circular patch antenna for dual‐frequency RFID application
Authors: Tiang Jun‐Jiat , Islam M. T. , Misran Norbahiah , Singh J. Mandeep
Published: March 2014

In this article, a new high‐gain wideband L‐probe proximity‐fed circular patch antenna using electrically thick substrate is proposed. By employing a dual‐patch microstrip antenna excited by two L‐probes, the bandwidths requirement for the ultrahigh frequency (UHF) and microwave radio frequency identification (RFID) application are met. The antennas integrated with slot‐loading techniques are extensively studied. It is demonstrated that the proposed antenna achieves widebands of UHF and microwave for RFID application. A good agreement is obtained between the computed and measured results. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1421–1424, 2014
Compact branch‐line coupler with harmonics suppression using meander T‐shaped line
Authors: Choi Kyo‐Soon , Yoon Ki‐Cheol , Lee Jae‐Yeong , Lee Choul‐Ki , Kim Seong‐Cheol , Kim Ki‐Byoung , Lee Jong‐Chul
Published: March 2014

In this article, a new compact branch‐line coupler with third harmonics suppression using the meander T‐shaped line is suggested. The meander T‐shaped line works similar to a bandstop filter at the second and third harmonics frequencies. The size of the proposed coupler is 22.2 × 14.9 mm2, while a conventional coupler is 32.6 × 27.8 mm2. Thus, the proposed coupler is considerably smaller than the conventional coupler. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1382–1384, 2014
Coupled‐fed inverted‐F antenna using an inverted‐F coupling feed for small‐size LTE/WWAN tablet computer antenna
Authors: Wong Kin‐Lu , Chen Li‐Yu
Published: March 2014

A coupled‐fed inverted‐F antenna for small‐size dual‐wideband operation in the mobile communication devices, especially the slim tablet computers, for the long term evolution/wireless wide area network (LTE/WWAN) operation, is proposed. The antenna comprises a folded radiating strip and an inverted‐F coupling feed. The former is grounded to the device ground plane and is capacitively excited by the inverted‐F coupling feed. Two wide operating bands to cover the LTE/WWAN operation in the 704∼960 and 1710∼2690 MHz bands are generated for the antenna. In addition, the antenna's metal pattern has a planar structure and occupies a small area of 10 × 40 mm2 on a 0.4‐mm thick FR4 substrate. Operating principle and design considerations of the proposed antenna to generate the dual‐wideband operation are addressed. Experimental results of the fabricated antenna are also presented and discussed. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1296–1302, 2014
Compact circularly polarized microstrip antenna for GPS applications
Authors: Hou Ming‐Jyun , Row Jeen‐Sheen
Published: March 2014

A compact design of circularly polarized microstrip antennas is described. The antenna has a square‐ring radiating patch, and it is excited by a feeding network consisting of a quadrature coupler with dual lumped capacitors and an impedance‐matching circuit. The feeding network has a considerably smaller size than a traditional 90° hybrid, and therefore, it is placed at the inner slot of the square‐ring patch. By tuning the capacitance value of the lumped capacitors, the antenna can generate good circular polarization radiation. An antenna prototype designed for global positioning system applications is implemented. From the measured results, the 10 dB‐return‐loss bandwidth and 3 dB‐axial‐ratio bandwidth of the prototype are 3% and 1%, respectively. Simulation results obtained by HFSS are also provided to validate the experiment. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1293–1296, 2014
A low phase noise LC‐VCO for phase‐locked frequency synthesizers
Authors: Wang Hao X. , Zhang Wei , Liu Yan Y. , Zhang Liang
Published: March 2014

This article presents a low phase noise voltage‐controlled‐oscillator (VCO) using standard 0.18 um RF CMOS process. This VCO is based on the voltage‐biased technique with a tail‐current inductor. Design considerations toward low phase noise are given and some tradeoffs are also described. Measurements show that the VCO has a phase noise of −49.8 dBc/Hz at 1 kHz offset and −134.8 dBc/Hz at 1 MHz offset from the 1.49 GHz carrier frequency. Compared with some other recently reported current‐biased and voltage‐biased VCOs, this work shows a better phase noise performance with reasonable power consumption. This VCO has been successfully applied in phase‐locked frequency synthesizers. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1486–1492, 2014
A wide range monolithic pHEMT SPDT switch
Authors: Menbari Babak , Dousti Massoud , Hajghassem Hassan
Published: March 2014

In this study, we propose the design, fabrication, and measurement results of a −6 V single pole double throw (SPDT) switch in the frequency band of DC‐20 GHz. We use a pseudomorphic high electron mobility transistor (pHEMT) GaAs technology. This technology has a gate width of 0.15 μm and a cutoff frequency of 85 GHz. A high yield and good performance switch based on pHEMT transistor is presented for using in SPDT circuit. In this method, we can reduce the off mode capacitor of transistor (Coff) and optimize the transistor in switch mode. Therefore, this method increases the transistor isolation in “off” mode with no change in the resistance of transistor in “on” mode (Ron). Measurement results show that the insertion loss is 1 dB with variation of ±0.1 dB in the frequency bandwidth and its isolation is better than 35 dB. The linear power range of the circuit is 28 dBm. The chip size is 0.2 mm2 and very low power consumption of 25 μ w is achieved. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1454–1458, 2014
Design of CPW‐FED slot antenna for MIMO system applications
Authors: Ojaroudi Nasser , Ghadimi Noradin
Published: March 2014

In this article, a new design of coplanar waveguide‐fed slot antenna with E‐ring radiating stub for wireless local area network (WLAN) applications is proposed. The operating frequencies of the proposed antenna are 2.4/5.2/5.8 GHz, which covers the WLAN bands. The measured results of the proposed antenna show that the impedance bandwidths are from 2.27 to 2.86, 4.85 to 5.35, and 5.65 to 6.05 GHz. The presented antenna has a small size of 30 × 30 mm2. A multifeed four‐element planar array was designed and simulated. It shows that the features of low‐profile, good return loss, and small mutual coupling are promising for multiinput multioutput applications. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1278–1281, 2014
DC‐to‐67 GHz high‐speed BiCMOS BJT characterization with on‐wafer calibration and EM‐based de‐embedding
Authors: Bae Juseok , Jordan Scott , Nguyen Cam
Published: March 2014

Bipolar junction transistors (BJTs) in 0.18‐μm silicon germanium (SiGe) BiCMOS technology are characterized from DC–67 GHz using on‐wafer calibration standards along with an electromagnetic (EM)‐based de‐embedding technique. The common issue of narrow spacing between the interconnects in typical on‐wafer calibration standards that causes calibration error and difficulty in load‐standard design, is overcome with the proposed EM‐based de‐embedding. Appropriate spacing between the closely spaced interconnects is determined based on EM simulations. The parts of the interconnects including vias within the spacing, which have significant parasitics affecting the characterization accuracy at high frequencies and over wide frequency ranges that remain noncalibrated after calibration, are extracted using the EM‐based de‐embedding technique. The measured results of BJTs up to 67 GHz show that approximately less than 2‐dB insertion loss and 15‐deg phase differences are observed between the on‐wafer characterizations with and without the EM‐based de‐embedding, demonstrating that the on‐wafer characterization with EM‐based de‐embedding is useful for accurate characterization of devices at millimeter‐wave two frequencies. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1285–1292, 2014
Design method of a single‐ended GM boosted common‐gate CMOS low‐noise amplifier
Authors: Woo Sanghyun , Kim Hyoungsoo
Published: March 2014

A design method for a common‐gate (CG) low‐noise amplifier (LNA) for LTE applications is presented to have a boosted transconductance (gm) value in a single‐ended configuration. To overcome the constraint of the gm value for conventional CG LNAs for input matching, a notch filter is utilized at the singled‐ended LNA output load. With this topology, the effective gm can be freely increased for a high gain and low noise figure (NF) without affecting input impedance matching. Moreover, the linearity is also enhanced because the notch filter load can reduce high‐order harmonics of the operating frequency. A single‐ended LNA implemented in a 0.18‐μm CMOS process with this technique delivers a maximum voltage gain of 20.9 dB with a minimum NF of 2.6 dB, a third‐order intermodulation intercept point of −9 dBm with power consumption of 5.8 mW at 2.6 GHz. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1409–1412, 2014
Design of 5‐GHz CMOS LC VCO with dual tuning circuit
Authors: Hsu Meng‐Ting , Hung Jie‐An , Ou An‐Cheng
Published: March 2014

In this article, a linear tuning range, low power, and low phase noise of CMOS voltage controlled oscillator (VCO) is presented. The core circuit of VCO is adopted dual‐tuning LC resonator with two transformer coupling structure. The bandwidth of the frequency range is from 4.85 to 5.84 GHz with a 18.5% tuning ratio by two tuning voltages. The phase noise of the proposed VCO is −119.3 dBc/Hz at 1 MHz offset frequency. The power consumption is 5.2 mW from 1 V supply and the KVCO exhibits the linearity with 240 MHz/V. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1356–1360, 2014
A meandering substrate integrated waveguide with slots for frequency scanning array
Authors: Chiu Leung
Published: March 2014

A meandered substrate integrated waveguide (SIW) has been proposed for the frequency scanning array that has potential application of the low cost 24‐GHz Doppler radar system. All radiating slots are connected in series using a short circuit ended SIW; therefore, its radiation beam can be steered with frequency. The modified antenna with meandering structure is proposed to enhance the scanning range. The physical slot spacing is kept at about half free space waveguide, whereas the electrical spacing is about 540° at the center frequency of 24 GHz. A broadside radiation is achieved at 24‐GHz frequency and a ±30° continuous scanning range is experimentally confirmed with the frequency band from 23 to 25 GHz. Another antenna with center frequency of 77 GHz is designed and tested. It also achieves a ±30° continuous scanning range with the frequency band from 75 to 79 GHz. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1478–1483, 2014
A 2 × 1 multiband MIMO antenna system consisting of miniaturized patch elements
Authors: Khan Muhammad. U. , Sharawi Mohammad. S.
Published: March 2014

The design of a compact two element multiple‐input‐multiple‐output (MIMO) antenna system is presented. The antenna operates in four bands. It resonates at 750 MHz, 1.17 GHz, 1.7 GHz, and 2.35 GHz. The elements of the MIMO antenna system are patch antennas loaded with complementary split‐ring resonators (CSRR). A CSRR is used to lower the resonant frequency of the patch as well as to achieve multiple resonances. The antenna occupies a total space of 120 × 60 × 0.8 mm3. Measured results of fabricated antenna show good agreement with simulation results. The evaluation of antenna for various parameters including bandwidth, isolation, total active reflection coefficient, mean effective gain, correlation coefficient, and radiation patterns is presented in this article. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1371–1375, 2014
Novel wideband high‐efficiency high‐power amplifier using microstrip radial stub for 4G communication systems
Authors: Wang Zhebin , Park Chan‐Wang
Published: March 2014

This article presents a novel wideband GaN HEMT power amplifier (PA) using microstrip radial stub (MRS) to realize wideband harmonic suppression. The angle and the bottom length of MRS are analyzed. One wideband PA is fabricated using MRS in both input and output matching networks to demonstrate this wideband method. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1412–1418, 2014
Experimental characterization of FSS for WLAN applications with low‐cost UWB elliptical microstrip monopole antennas
Authors: Nóbrega Clarissa de L. , da Silva Marcelo R. , Silva Paulo H. da F. , D'Assunção Adaildo. G.
Published: March 2014

In this work, we propose an elliptical microstrip monopole antenna with ultrawideband (UWB) characteristics to be applied in low cost measurements of frequency selective surfaces (FSSs). The −10‐dB impedance bandwidth of the elliptical antenna is 1.0–13.5 GHz, which is about 172% broader. To demonstrate the antenna application in FSS measurements, we also propose a dual‐band band‐stop FSS with metallic patches based on teragon fractal geometry designed to reject wireless local area network signals. Theoretical analysis of the elliptical monopole and FSS is done using Ansoft HFSS and Ansoft DesignerTM commercial softwares, respectively. Prototypes of designed antenna and FSS were built and measured. Through the use of UWB monopole antennas, we obtained an excellent agreement between simulated and measured FSS transmission coefficients. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1331–1333, 2014
Detecting coevolution in mammalian sperm–egg fusion proteins
Authors: Claw Katrina G. , George Renee D. , Swanson Willie J.
Published: March 2014

Interactions between sperm and egg proteins can occur physically between gamete surface‐binding proteins, and genetically between gamete proteins that work in complementary pathways in which they may not physically interact. Physically interacting sperm–egg proteins have been functionally identified in only a few species, and none have been verified within mammals. Candidate genes on both the sperm and egg surfaces exist, but gene deletion studies do not support functional interactions between these sperm–egg proteins; interacting sperm–egg proteins thus remain elusive. Cooperative gamete proteins undergo rapid evolution, and it is predicted that these sperm–egg proteins will also have correlated evolutionary rates due to compensatory changes on both the sperm and egg. To explore potential physical and genetic interactions in sperm–egg proteins, we sequenced four candidate genes from diverse primate species, and used regression and likelihood methods to test for signatures of coevolution between sperm–egg gene pairs. With both methods, we found that the egg protein CD9 coevolves with the sperm protein IZUMO1, suggesting a physical or genetic interaction occurs between them. With regression analysis, we found that CD9 and CRISP2 have correlated rates of evolution, and with likelihood analysis, that CD9 and CRISP1 have correlated rates. This suggests that the different tests may reflect different levels of interaction, be it physical or genetic. Coevolution tests thus provide an exploratory method for detecting potentially interacting sperm–egg protein pairs. Mol. Reprod. Dev. 81: 531–538, 2014. © 2014 Wiley Periodicals, Inc.
Effects of a 1‐year exercise and lifestyle intervention on irisin, adipokines, and inflammatory markers in obese children
Authors: Blüher Susann , Panagiotou Grigorios , Petroff David , Markert Jana , Wagner Antje , Klemm Thorsten , Filippaios Andreas , Keller Alexandra , Mantzoros Christos S.
Published: March 2014

Objective

Exercise improves weight status and metabolism. Irisin, a novel myokine, may be involved in the regulation of metabolic function. The effect of an exercise and dietary lifestyle intervention for 1‐year on irisin, adipokines (leptin, adiponectin, resistin) and inflammatory markers (C‐reactive protein (CRP), soluble tumor necrosis factor receptor II (sTNFR‐II) was evaluated, and predictors of irisin levels were characterized in obese children.

Methods

Parameters were assessed at baseline and at follow‐up for 65 obese children who completed the program (7–18 years, 54%boys). Their relation to weight status and metabolic risk was analyzed.

Results

Anthropometric and metabolic parameters improved after completion of the program. Circulating irisin levels at baseline were 111.0 ± 8.0 ng ml−1 and increased after the intervention by 12% [6%, 17%], P = 0.00003. There was no evidence for differences in irisin levels between genders and across age. Moreover, changes in irisin did not correlate with those in BMI‐SDS, adipokines or inflammatory markers. Leptin decreased after the intervention (Δ5.3 ng ml−1, [3.2, 6.3], P = 10−7). Anthropometric measures were significantly associated with leptin and inflammatory markers.

Conclusions

A 1‐year long lifestyle intervention program is associated with improvement in anthropometric and metabolic parameters and leads to an elevation in irisin levels in obese children.
Intramolecular electron transfer and charge delocalization in bistable donor–acceptor systems based on perchlorotriphenylmethyl radicals linked to ferrocene and tetrathiafulvalene units
Authors: Souto Manuel , Morales Dayana C. , Guasch Judith , Ratera Imma , Rovira Concepció , Painelli Anna , Veciana Jaume
Published: March 2014

A comparative analysis of the physicochemical properties of different donor–acceptor dyads, based on a perchlorotriphenylmethyl radical acceptor subunit linked through a vinylene π‐bridge to ferrocene derivatives (1–3) or a tetrathiafulvalene (4) donor subunit, is presented. Intramolecular electron transfer and charge delocalization of these donor–acceptor dyads are discussed on the basis of data obtained in solution by cyclic voltammetry, UV–Vis near‐infrared, and electron spin resonance spectroscopies. Bistability in the crystalline phase is also discussed on the basis of the results provided by X‐ray diffraction analysis and temperature‐dependent Mössbauer spectra. Copyright © 2014 John Wiley & Sons, Ltd.
Effect of tetra‐n‐butylammonium bromide salt on the cationic polymerization of dimethylketene and on the thermal properties of the obtained polyketones
Authors: Wang Hanbin , Desilles Nicolas , Burel Fabrice
Published: March 2014

The cationic polymerization of dimethylketene is achieved in dichloromethane at −30 °C, using a stoichiometric mixture of aluminum bromide (AlBr3) and tetra‐n‐butylammonium bromide (n‐Bu4N+Br−) as initiator. Characterizations by 1H and 13C NMR show that the resulting polymers have a perfect polyketonic microstructure. Capillary viscosity, DSC, and SEC analysis show that for a constant monomer/initiator ratio, polymers synthesized in the presence of tetra‐n‐butylammonium bromide are more crystalline and have better properties than those produced only with AlBr3. Melting temperatures, inherent viscosities and average molecular weights are systematically higher. A good linearity is observed between ln (inherent viscosity) versus ln
for the system with n‐Bu4N+Br−, showing a good control of the molecular weight by the initial feed ratio. The effect of this compound suggests a reversible equilibrium between active and dormant species, which limits the transfer and/or termination reactions, and enables a better control of the cationic polymerization. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 1493–1499
Effect of pressure on the flow behavior of polybutene
Authors: Ponjavic Aleks , di Mare Luca , Wong Janet S. S.
Published: March 2014

The rheology of submicron thick polymer melt is examined under high normal pressure conditions by a recently developed photobleached‐fluorescence imaging velocimetry technique. In particular, the validity and limitation of Reynold equation solution, which suggests a linear through‐thickness velocity profile, is investigated. Polybutene (PB) is sheared between two surfaces in a point contact. The results presented in this work suggest the existence of a critical pressure below which the through‐thickness velocity profile is close to linear. At higher pressures however, the profile assumes a sigmoidal shape resembling partial plug flow. The departure of the sigmoidal profile from the linear profile increases with pressure, which is indicative of a second‐order phase/glass transition. The nature of the transition is confirmed independently by examining the pressure‐dependent dynamics of PB squeeze films. The critical pressure for flow profile transition varies with molecular weight, which is consistent with the pressure‐induced glass transition of polymer melt. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014, 52, 708–715
Solubility Determination of Raw Energetic Materials in Molten 2,4‐Dinitroanisole
Authors: Grau Henry , Gandzelko Aleksander , Samuels Philip
Published: March 2014

2,4‐Dinitroanisole (DNAN) is an ingredient used in several insensitive munition formulations that have recently been qualified by the US Army. A phenomenon known as irreversible growth is found to occur during conditioning cycles of insensitive munitions (IM) that contain DNAN. A possible cause of the irreversible growth maybe the potential solubility of energetic components formulated with melted DNAN. This report documents methods development and procedures used to determine the solubility of energetic constituents in molten DNAN at 100 °C. High performance liquid chromatography and ion chromatography were used for quantitation. Solubilities (given as g energetic per 100 g DNAN) of RDX, HMX, NTO, NQ, and AP were found as 13.7, 3.02, 0.222, 0.448, and 0.088, respectively.
Facile Preparation of Self‐Sensitized FOX‐7 with Uniform Pores by Heat Treatment
Authors: Li Tingting , Li Rui , Nie Fude , Wang Jun , Huang Weigang , Yang Guangcheng
Published: March 2014

Self‐sensitized FOX‐7 (1,1‐diamino‐2,2‐dinitroethylene) was prepared by a facile heat treatment process near the decomposition temperature. Field emission scanning electron microscopy (FE‐SEM) shows the self‐sensitized FOX‐7 becomes multiple layers and porous after heat treatment. N2 adsorbance measurements revealed that its specific surface area (6.754 m2 g−1) is 20 times of the area of expanded ammonium nitrate. The SAXS tests further indicate the existence of a large amount of voids in self‐sensitized FOX‐7 and the pore size is about 30 nm, belonging to mesopore (2.0–50 nm). Based on the analysis of X‐ray powder diffraction (XRD), the self‐sensitized porous FOX‐7 consists of α‐phase and a spot of γ‐phase. The TG‐DSC results show that the self‐sensitized FOX‐7 exhibits excellent thermal stability. The impact, frication and electrostatic spark sensitivities of self‐sensitized FOX‐7 also have considerable enhancement. This new method provides a promising route for exploring new green primary explosive replacements.
Fibrin‐targeted plasminogen activation by plasminogen activator, PadA, from Streptococcus dysgalactiae
Authors: Singh Satish , Bhando Timsy , Dikshit Kanak L.
Published: March 2014

Bacterial plasminogen activators differ from each other in their mechanism of plasminogen activation besides their host specificity. Three‐domain streptokinase (SK) and two‐domain PauA generate nonproteolytic active site center in their cognate partner plasminogen but their binary activator complexes are resistant to α2‐antiplasmin (a2AP) inhibition causing nonspecific plasminogen activation in plasma. In contrast, single‐domain plasminogen activator, staphylokinase (SAK), requires proteolytic cleavage of human plasminogen into plasmin for the active site generation, and this activator complex is inhibited by a2AP. The single‐domain plasminogen activator, PadA, from Streptococcus dysgalatiae, having close sequence and possible structure homology with SAK, was recently reported to activate bovine Pg in a nonproteolytic manner similar to SK. We report hereby that the binary activator complex of PadA with bovine plasminogen is inhibited by a2AP and PadA is recycled from this complex to catalyze the activation of plasminogen in the clot environment, where it is completely protected from a2AP inhibition. Catalytic efficiency of the activator complex formed by PadA and bovine plasminogen is amplified several folds in the presence of cyanogen bromide digested fibrinogen but not by intact fibrinogen indicating that PadA may be highly efficient at the fibrin surface. The present study, thus, demonstrates that PadA is a unique single‐domain plasminogen activator that activates bovine plasminogen in a fibrin‐targeted manner like SAK. The sequence optimization by PadA for acquiring the characteristics of both SK and SAK may be exploited for the development of efficient and fibrin‐specific plasminogen activators for thrombolytic therapy.
The crystal structure of NS5A domain 1 from genotype 1a reveals new clues to the mechanism of action for dimeric HCV inhibitors
Authors: Lambert Sebastian M. , Langley David R. , Garnett James A. , Angell Richard , Hedgethorne Katy , Meanwell Nicholas A. , Matthews Steve J.
Published: March 2014

New direct acting antivirals (DAAs) such as daclatasvir (DCV; BMS‐790052), which target NS5A function with picomolar potency, are showing promise in clinical trials. The exact nature of how these compounds have an inhibitory effect on HCV is unknown; however, major resistance mutations appear in the N‐terminal region of NS5A that include the amphipathic helix and domain 1. The dimeric symmetry of these compounds suggests that they act on a dimer of NS5A, which is also consistent with the presence of dimers in crystals of NS5A domain 1 from genotype 1b. Genotype 1a HCV is less potently affected by these compounds and resistance mutations have a greater effect than in the 1b genotypes. We have obtained crystals of domain 1 of the important 1a NS5A homologue and intriguingly, our X‐ray crystal structure reveals two new dimeric forms of this domain. Furthermore, the high solvent content (75%) makes it ideal for ligand‐soaking. Daclatasvir (DCV) shows twofold symmetry suggesting NS5A dimers may be of physiological importance and serve as potential binding sites for DCV. These dimers also allow for new conformations of a NS5A expansive network which could explain its operation on the membranous web. Additionally, sulfates bound in the crystal structure may provide evidence for the previously proposed RNA binding groove, or explain regulation of NS5A domain 2 and 3 function and phosphorylation, by domain 1.
Explosion limits of industrial spirit and their affecting by temperature
Authors: Lepik Petr , Mynarz Miroslav , Serafin Jiri , Bernatik Ales
Published: March 2014

The article deals with the determination of industrial spirit's explosion limits and their affecting by temperature. It describes the determination of explosion limits and the influence of temperature by correlation equations available in professional literature, as well as the validation of these data by means of experiments in explosion autoclave and explosion chamber. © 2014 American Institute of Chemical Engineers Process Saf Prog 33: 380–384, 2014
Perfect simulation of processes with long memory: A “coupling into and from the past” algorithm
Authors: Garivier Aurélien
Published: March 2014

We describe a new algorithm for the perfect simulation of variable length Markov chains and random systems with perfect connections. This algorithm, which generalizes Propp and Wilson's simulation scheme, is based on the idea of coupling into and from the past. It improves on existing algorithms by relaxing the conditions on the kernel and by accelerating convergence, even in the simple case of finite order Markov chains. Although chains of variable or infinite order have been widely investigated for decades, their use in applied probability, from information theory to bio‐informatics and linguistics, has recently led to considerable renewed interest. © 2014 Wiley Periodicals, Inc. Random Struct. Alg., 46, 300–319, 2015
Dual beam organic depth profiling using large argon cluster ion beams
Authors: Holzweber M. , Shard A. G. , Jungnickel H. , Luch A. , Unger W. E. S.
Published: March 2014

Argon cluster sputtering of an organic multilayer reference material consisting of two organic components, 4,4′‐bis[N‐(1‐naphthyl‐1‐)‐N‐phenyl‐ amino]‐biphenyl (NPB) and aluminium tris‐(8‐hydroxyquinolate) (Alq3), materials commonly used in organic light‐emitting diodes industry, was carried out using time‐of‐flight SIMS in dual beam mode. The sample used in this study consists of a ~400‐nm‐thick NPB matrix with 3‐nm marker layers of Alq3 at depth of ~50, 100, 200 and 300 nm. Argon cluster sputtering provides a constant sputter yield throughout the depth profiles, and the sputter yield volumes and depth resolution are presented for Ar‐cluster sizes of 630, 820, 1000, 1250 and 1660 atoms at a kinetic energy of 2.5 keV. The effect of cluster size in this material and over this range is shown to be negligible. © 2014 The Authors. Surface and Interface Analysis published by John Wiley & Sons Ltd.