bluuebunny/crossref_metadata_2025 huggingface dataset:
Multiwalled‐carbon‐nanotubes‐based matrix solid‐phase dispersion extraction coupled with high‐performance liquid chromatography for the determination of honokiol and magnolol in Magnoliae Cortex
Authors: Zhang Qi , Hong Bo , Liu Jianhua , Mu Guangze , Cong Huan , Li Gang , Cai Defu
Published: March 2014

In this paper, multiwalled‐carbon‐nanotube‐based matrix solid‐phase dispersion coupled to HPLC with diode array detection was used to extract and determine honokiol and magnolol from Magnoliae Cortex. The extraction efficiency of the multiwalled‐carbon‐nanotube‐based matrix solid‐phase dispersion was studied and optimized as a function of the amount of dispersing sorbent, volume of elution solvent, and flow rate of elution solvent, with the aid of response surface methodology. An amount of 0.06 g of carboxyl‐modified multiwalled carbon nanotubes and 1.5 mL of methanol at a flow rate of 1.1 mL/min were selected. The method obtained good linearity (r2 > 0.9992) and precision (RSD < 4.7%) for honokiol and magnolol, with limits of detection of 0.045 and 0.087 μg/mL, respectively. The recoveries obtained from analyzing in triplicate spiked samples were determined to be from 90.23 to 101.10% and the RSDs from 3.5 to 4.8%. The proposed method that required less samples and reagents was simpler and faster than Soxhlet and maceration extraction methods. The optimized method was applied for analyzing five real samples collected from different cultivated areas.
Simultaneous quantitation of nucleosides, nucleobases, amino acids, and alkaloids in mulberry leaf by ultra high performance liquid chromatography with triple quadrupole tandem mass spectrometry
Authors: Zhang Li‐li , Bai Yong‐liang , Shu Shu‐lan , Qian Da‐wei , Ou‐yang Zhen , Liu Li , Duan Jin‐ao
Published: March 2014

An ultra high performance liquid chromatography coupled with a triple quadrupole mass detection and electrospray ionization mass spectrometry method has been established for the simultaneous determination of the 14 nucleosides and nucleobases, 24 amino acids and two main alkaloids in mulberry leaf. In this method, a complicated mobile phase, the flow rate of which was 0.4 mL/min, was applied to the gradient elution, which provided a satisfied separation of the 40 compounds. The present method was validated, and sufficient reproducibility and accuracy were obtained for the quantitative measurement of the 40 compounds. The method was subsequently applied to ten mulberry leaves and the results showed that almost all of these samples were rich in nucleosides, nucleobases, amino acids, and alkaloids. The proposed method, which is convenient and economical, could serve as a prerequisite for the quality control of mulberry leaf herbs and be applied analogously to other Chinese medicines.
Investigating rapid eye movement sleep without atonia in Parkinson's disease using the rapid eye movement sleep behavior disorder screening questionnaire
Authors: Bolitho Samuel J. , Naismith Sharon L. , Terpening Zoe , Grunstein Ron R. , Melehan Kerri , Yee Brendon J. , Coeytaux Alessandra , Gilat Moran , Lewis Simon J.G.
Published: March 2014

Rapid eye movement (REM) sleep behavior disorder (RBD) is frequently observed in patients with Parkinson's disease (PD). Accurate diagnosis is essential for managing this condition. Furthermore, the emergence of idiopathic RBD in later life can represent a premotor feature, heralding the development of PD. Reliable, accurate methods for identifying RBD may offer a window for early intervention. This study sought to identify whether the RBD screening questionnaire (RBDSQ) and three questionnaires focused on dream enactment were able to correctly identify patients with REM without atonia (RWA), the neurophysiological hallmark of RBD. Forty‐six patients with PD underwent neurological and sleep assessment in addition to completing the RBDSQ, the RBD single question (RBD1Q), and the Mayo Sleep Questionnaire (MSQ). The REM atonia index was derived for all participants as an objective measure of RWA. Patients identified to be RBD positive on the RBDSQ did not show increased RWA on polysomnography (80% sensitivity and 55% specificity). However, patients positive for RBD on questionnaires specific to dream enactment correctly identified higher degrees of RWA and improved the diagnostic accuracy of these questionnaires. This study suggests that the RBDSQ does not accurately identify RWA, essential for diagnosing RBD in PD. Furthermore, the results suggest that self‐report measures of RBD need to focus questions on dream enactment behavior to better identify RWA and RBD. Further studies are needed to develop accurate determination and quantification of RWA in RBD to improve management of patients with PD in the future. © 2014 International Parkinson and Movement Disorder Society
Loss of ALDH18A1 function is associated with a cellular lipid droplet phenotype suggesting a link between autosomal recessive cutis laxa type 3A and Warburg Micro syndrome
Authors: Handley Mark T. , Mégarbané André , Meynert Alison M. , Brown Stephen , Freyer Elisabeth , Taylor Martin S. , Jackson Ian J. , Aligianis Irene A.
Published: March 2014

Autosomal recessive cutis laxa type 3A is caused by mutations in ALDH18A1, a gene encoding the mitochondrial enzyme ∆1‐pyrroline‐5‐carboxylate synthase (P5CS). It is a rare disorder with only six pathogenic mutations and 10 affected individuals from five families previously described in the literature. Here we report the identification of novel compound heterozygous missense mutations in two affected siblings from a Lebanese family by whole‐exome sequencing. The mutations alter a conserved C‐terminal domain of the encoded protein and reduce protein stability as determined through Western blot analysis of patient fibroblasts. Patient fibroblasts exhibit a lipid droplet phenotype similar to that recently reported in Warburg Micro syndrome, a disorder with similar features but hitherto unrelated cellular etiology.
Insights from QM/MM Modeling the 3D Structure of the 2009 H1N1 Influenza A Virus Neuraminidase and Its Binding Interactions with Antiviral Drugs
Authors: Wang Yeng‐Tseng , Chen Yu‐Ching
Published: March 2014

Control of drug release through the inhibition of neuraminidase‐1 has been identified as a potential target for the treatment of H1N1 influenza; however, the drug binding mode of neuraminidase is not yet completely understood. In this work, we propose a model for a neuraminidase‐1 complex based on four known X‐ray structures of drug/neuraminidase‐1 complexes. Specifically, H1N1 neuraminidase‐1 complexed with 4 drugs (zanamivir, laninamivir, laninamivir octanoate and oseltamivir) was first investigated using a combined quantum mechanical and molecular mechanical (QM/MM) approach. Based on these structures, a model for the H1N1 neuraminidase‐1 complex was proposed and simulated using the same computational protocol. Implications to drug/H1N1 neuraminidase‐1 binding modes are discussed. From our simulations, the predicted binding free energies of the four drugs are in good agreement with the experimental results, with the correlation coefficient being 0.84.
Theoretical Studies on Pyrazolo[3,4‐d]pyrimidine Derivatives as Potent Dual c‐Src/Abl Inhibitors Using 3D‐QSAR and Docking Approaches
Authors: Zeng Guo Hua , Fang Dan Qing , Wu Wen Juan , Wang Ju Ping , Xie Wen Guo , Ma Shao Jie , Wu Jing Heng , Shen Yong
Published: March 2014

In recent years, the development of dual or multi‐targeted inhibitors has captured extensive attention of research for treating of malignancies. In this paper, three‐dimensional quantitative structure‐activity relationship and docking studies were performed on 87 pyrazolo[3,4‐d]pyrimidines as dual Src/Abl inhibitors. The appropriate binding orientations and conformations of these compounds interacting with both Src and Abl kinases were revealed by docking studies, and the established optimum CoMFA models yielded q2=0.856, R2=0.966 for Src and q2=0.869, R2=0.974 for Abl, and the best CoMSIA models gave q2=0.877, R2=0.979 for Src and q2=0.885, R2=0.982 for Abl. Systemic external validations further confirm the satisfactory predictive power of these models, producing R2pred values of 0.872 and 0.865 for Src, 0.876 and 0.867 for Abl, r2m values of 0.832 and 0.928 for Src, 0.838 and 0.904 for Abl, respectively. In addition, through a comparison between 3D‐QSAR contour maps and docking results, it is revealed that the hydrophobic and electrostatic interactions of compounds play significant roles for the inhibitory activity against both Src and Abl kinases. Some structural factors influencing the activities of these compounds were discussed in detail. The key amino acids impacting the receptor‐ligand interactions have been identified. These theoretical results can offer useful references for designing novel potential dual Src/Abl inhibitors.
The applications of Saddle point theorem to Dirichlet boundary value problem of differential system
Authors: Ge Weigao , Tian Yu
Published: March 2014

We study in this paper the Dirichlet boundary value problem of second‐order differential system in the form
urn:x-wiley:1704214:media:mma2997:mma2997-math-0001 where u ∈ Rn,A,B ∈ Rn,M ∈ Rn × n is a symmetric matrix, F : [0,1] × Rn → Rn such a system comes from a model describing the vibration of a multi‐storey building. By using the saddle point theorem, we prove an existence theorem for the solutions to the given system. Copyright © 2014 John Wiley & Sons, Ltd.
Bifurcations in a diffusive predator–prey model with predator saturation and competition response
Authors: Sambath M. , Balachandran K.
Published: March 2014

A diffusive predator–prey model with predator saturation and competition response subject to homogeneous Neumann boundary conditions is considered in this paper. We find that the spatially homogeneous and non‐homogeneous periodic solutions through all parameters of the system are spatially homogeneous. To verify our theoretical results, some numerical simulations are also carried out. Copyright © 2014 John Wiley & Sons, Ltd.
Highly sensitive refractive index measurement based an a thinned fiber taper
Authors: Du Chengliang , Yang Xianhui
Published: March 2014

A thinned fiber taper (TFT) with high refractive index (RI) sensitivity has been fabricated by a fusion splicer. The TFT has a total length of about 1.3 mm and a waist diameter of less than 10 μm. Simulations of the TFT have been implemented and the RI experiments show a remarkable sensitivity. The highest RI sensitivities of 6360 nm/RI unit (RIU) and 3850 nm/RIU in the RI ranges of 1.409–1.423 and 1.333–1.353, respectively, have been obtained on two TFTs with different taper waist diameters. The RI dynamic ranges of the TFTs also have been discussed. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1054–1057, 2014
A cavity‐backed spiral slot antenna with wide axial ratio beamwidth for GPS system
Authors: Bao Xiulong L. , Ammann M. J.
Published: March 2014

A monofilar spiral slot antenna with a cavity‐backed reflector is presented, which can achieve the performance of the wide axial ratio beamwave for global positioning system (GPS) system. It comprises an arrangement of a single printed spiral slots fed by a 50‐Ω microstrip line. By using cavity‐backed covering the slot structure, a wide axial ratio beamwidth performance is achieved in the GPS L1 frequency. The angle with less than 3‐dB axial ratio at 1.575 GHz in the YoZ plane is about 215°. The measured results show that the HPBW beamwidths at 1.575 GHz are 100° in the YoZ plane, respectively. The peak gain is 5.5 dBic. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1050–1054, 2014
Calderón preconditioner for a marching‐on‐in‐degree solution of time‐domain electric field integral equation
Authors: Shi Yan , Tang Wei , Liang Chang‐Hong
Published: March 2014

A marching‐on‐in‐degree (MOD)‐based scheme has been developed to solve a Calderón preconditioned time‐domain electric field integral equation (TDEFIE) for the analysis of transient scattering from an arbitrarily closed conducting object. By using the time‐domain Calderón identity, the TDEFIE is immune to dense mesh breakdown. With the use of weighted Laguerre polynomials as entire‐domain temporal basis functions and the Galerkin temporal testing procedure, the MOD algorithm overcomes the late‐time instability. Numerical results show that the proposed algorithm can give rise to rapidly convergent solutions. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1069–1072, 2014
Compact and miniaturized bandstop filter developed using slot spurline technique
Authors: Shrestha Bhanu , Kim Nam‐Young
Published: March 2014

A compact and miniaturized bandstop filter (BSF) developed based on the slot spurline technique was designed and characterized. The reflection zero of the BSF was carefully controlled through optimized simulations. Two meandered lines were used to enhance the coupling effect and to control the frequency of the BSF. These double spiral slot lines were used to achieve the dual mode of operation as well as to optimize the insertion loss by adjusting the length of the slot lines. Therefore, the proposed BSF achieves a low insertion loss and wider band‐rejection characteristics. The operating frequency of the BSF is 10.5 GHz for X‐band applications, with a minimum insertion loss of less than −25 dB and a return loss below −1.2 dB based on measurement results. The results obtained for this resonator demonstrate the possibility of integrating the device into small structures via MMIC technology. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1029–1031, 2014
A high gain patch antenna based PN zero permeability metamaterial
Authors: Hou Quanwen W. , Su Yan Y. , Zhao Xiaopeng P.
Published: March 2014

A zero refractive index metamaterial is designed, and the zero refractive index is caused by the magnetic resonance. Based on the metamaterial, a zero index lens antenna is designed, fabricated, and measured. Due to the wave converging effect of the zero index lens, the gain of the new designed antenna reaches 11.7 and 4.8 dB higher than the original antenna without the lens. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1065–1069, 2014
Simple ku‐band radio over fiber system with high‐dispersion tolerance using a polymer‐based microring resonator filter
Authors: Gu Yiying , Han Xiuyou , Wang Linghua , Wang Jinyan , Wu Zhenlin , Zhao Mingshan
Published: March 2014

This article presents an optical single sideband (SSB) signal generation in radio over fiber system using a polymeric microring resonator as an optical notch filter, alleviating the fiber chromatic dispersion‐induced carrier fading problem. With this technique, optical SSB radio frequency (RF) signal with a RF frequency of 14.35 GHz carrying 40‐Mbps quadrature phase shift keying vector signal is generated. This signal is transmitted over 25‐km standard single‐mode fiber successfully, and the received signal error vector magnitude is 5.8% rms. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1129–1133, 2014
Novel balanced wideband filters using microstrip coupled lines
Authors: Wang Xiao‐Hua , Zhang Hualiang
Published: March 2014

In this article, a novel balanced wideband filter based on microstrip coupled lines is proposed. It features characteristics such as wide bandwidth, compact size, and good common‐mode suppression. The proposed balanced filter was calculated analytically, simulated by full‐wave electromagnetic simulator and validated by the measurements. The calculated, simulated, and measured results are in good agreement with each other. The experimental results show that it can allow the differential‐mode signal to be transmitted with low insertion loss across a wide frequency band, whereas the common‐mode signal will be well suppressed. The fractional bandwidth of the designed filter is 88%. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1139–1141, 2014
An ultrawideband single Notched‐Band bandpass filter by consisting of CRLH TL and EOS
Authors: Yi Qiang , Zhang Meng , Zhou Fukun , Luo Xingfang
Published: March 2014

An ultrawideband (UWB) band pass filter (BPF) with a single notched band is presented in this article according to the UWB system and is easy to be interfered with the narrow band signals. To avoid the undesired interferences such as wireless local area networks signals, an embedded open‐circuited stub (EOS) is used to obtain a narrow notched band. The proposed filter is mainly composed of one composite right/left handed transmission line unit cell and an EOS. The simulation results show that 3‐dB passband of the BPF is from 2.68 to 10.75 GHz. The variation of group delay is less than 0.1 ns in the passband except for the notched band. The characteristic of frequency response at center frequency around 5.25 GHz is about −38 dB which represents the good rejection performance. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1115–1118, 2014
Compact sectoral fractal planar monopole antenna for wideband wireless applications
Authors: Choukiker Yogesh Kumar , Behera Santanu Kumar
Published: March 2014

A compact size sectoral fractal planar monopole antenna is proposed for wideband wireless application. The feed circuit is a 50‐Ω microstrip line with a matching section over a rectangular ground plane. The measured −10 dB reflection bandwidth for frequency range (3.22–6.55 GHz) is 68.04% covering WiMAX (3.4–3.6 and 3.7–4.2 GHz), Wi‐Fi 802.11y (3.6–3.7 GHz), and WLAN 802.11 (5.31–6.32 GHz). This antenna has acceptable agreement is obtained for the simulated and measured antenna performance parameters. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1073–1076, 2014
Theoretical models for microwave pulse induced thermal failure in CMOS integrated circuits
Authors: Chen Jie , Du Zhengwei
Published: March 2014

Critical issues regarding the microwave pulse induced irreversible failures in individual metal–oxide–semiconductor field‐effect transistors and CMOS integrated circuits have been well addressed in this article. The fundamental mechanisms for irreversible failures are analyzed, and a theoretical foundation based on the microwave pulse induced thermal effects is developed. Two theoretical models that capture the effects of pulse width and pulse repetition frequency (PRF), respectively, are formulated. In comparison to the numerical results obtained from device simulations and the experimental data reported in literature, the validity of these two theoretical models has been verified. The pulse width dependent failure model describes an asymptotic behavior of a failure threshold versus pulse width dependence. It suggests a substantial decrease in the failure threshold for very short pulse width range and a smooth transition to constant power requirement for long pulse width range due to thermal equilibrium. The PRF dependent failure model indicates an inverse relationship between the failure threshold and the PRF or the number of pulses. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1144–1151, 2014
Evaluation of nonlinear distortion in optically switchable UWB filters
Authors: Chakrabarty K. , Rabbi K. , Panagamuwa C. , Kodogiannis V. , Budimir Djuradj
Published: March 2014

This article provides a complete evaluation of nonlinear distortion for a switchable ultrawideband (UWB) filter. The proposed structure can provide a good performance with very little loss. An optical switch is used to switch the filter from bandpass to bandstop response at the same UWB spectrum. The switch comprises of a silicon dice which can be activated using near infrared light. The switchable UWB filter behaves as a bandpass filter while the switch is in the ON state and acts as a bandstop filter while in the OFF state. The filter was fabricated with the optical switch incorporated in it. Distortion measure was carried out using 5 MHz digitally modulated signals such as WCDMA and LTE. Distortion analysis carried out on the optically reconfigurable filter proved it to be highly linear. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1092–1094, 2014
A CPW‐fed printed antenna with band‐notched function using an M‐shaped slot
Authors: Zehforoosh Yashar , Sedghi Tohid
Published: March 2014

A recently designed printed slot antenna is presented that incorporates variable band‐notched function for ultrawideband applications. The band notch of this coplanar waveguide fed antenna is achieved by an M‐shaped slot embedded in the radiating element, so a narrow rejected property in the wireless local area network band (5.15–5.825 GHz) is obtained. The rectangular aperture etched in the square ground plane has a determinative role in antenna's impedance band width (IBW) enhancement, and carefully adjusting it leads to wide IBW that due to simulated results it covers the frequency range 2.58–12.86 GHz with VSWR ≤ 2, which corresponds to a fractional bandwidth of 133% excluding the rejected band around 5.04–6.08 GHz. Numerical and experimental results are presented to understand its behavior. The volume of the proposed antenna is 25 × 25 × 0.8 mm3. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1088–1092, 2014
A broadband slab lens antenna formed from gradient refractive index metamaterials composed of cross‐shaped cells
Authors: Yuan Guishan , Dong Xiaochun , Deng Qiling , Liu Chunheng , Lu Yueguang , Shi Haofei , Du Chunlei
Published: March 2014

A slab lens antenna has been designed to enhance the directivity of a horn antenna efficiently in a wide range of frequencies. A gradient refractive index metamaterial is utilized to compensate phases of electromagnetic waves radiated from a horn, which can transform the cylindrical wave into a plane wave. To obtain broadband property, the gradient refractive index metamaterial composed of cross‐shaped conductor, which works in a nonresonant status is designed, and the metamaterial is proved to be broadband, polarization insensitive, and lossless. The slab lens is designed by a collection of metamaterial unit cells with different geometric parameters, where the effective refractive index of the unit cells are determined by the size of cross‐shaped conductors to form the required inhomogeneous refractive index distribution. The simulation and experiment results show that the lens located in front of a horn can considerably compress the antenna's radiation patterns over a wide band range from 12 to 18 GHz. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1124–1129, 2014
An X‐band CMOS power amplifier with a driver stage using a shot‐through current rejection technique
Authors: Park Jonghoon , Park Changkun
Published: March 2014

In this study, we design an X‐band switching‐mode CMOS power amplifier using 0.13‐μm RF CMOS process. The power amplifier is composed of driver and power stages. In this study, we focus on the power consumption of the driver stage. To minimize power consumption, we propose a shot‐through current rejection technique for the Class‐D amplifier used as a driver stage of the CMOS power amplifier. We split the gate bias of the NMOS and PMOS of the Class‐D amplifier using DC‐blocking capacitors to control the shot‐through current. From the measured results, we successfully prove the feasibility of the proposed technique. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1159–1162, 2014
Effect of Ba‐Co ferrite on bandwidth of monopole antenna
Authors: Lin Wen‐Kuan , Chen Lih‐Shan , Wang Chia‐Hung
Published: March 2014

Characteristics of circular monopole antenna coated with lossy ferrite film was investigated and compared to the original antenna. The adopted coating material is hexagonal barium‐cobalt ferrite (Ba4Co2Fe36O60), which plays the role of microwave absorption in the ultrawideband, thereby increasing the bandwidth of the antenna. It was found that the maximum radiation efficiency of antenna reduced slightly from 87 to 68% due to microwave absorption of ferrite film. However, by the use of ferrite film, the bandwidth significantly increased from 8.5 to above 16.6 GHz, and the first resonance frequency reduced from 4.4 to 4.1 GHz. Both simulated and measured results showed that Ba‐Co ferrite film is effective in broadening of bandwidth, while retaining acceptable radiation efficiency. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1181–1184, 2014
A CPW‐fed circular wide‐slot UWB antenna with dual‐notch bands by combining slot and parasitic element techniques
Authors: Li Yingsong , Li Wenxing , Ye Qiubo
Published: March 2014

A compact coplanar waveguide fed circular wide‐slot antenna with dual‐band‐notched characteristic is proposed by using an arc‐shaped slot (ASS) and an arc‐shaped parasitic element (ASPE) for ultra‐wideband (UWB) communication applications. The center frequencies of the dual‐notch bands can be tuned in a wide range by adjusting the parameters of the ASS and the ASPE. Both the numerical and experimental results show that the proposed antenna can operate over a wide frequency band ranging from 2.7 to 12 GHz with VSWR < 2, with the exception of the two notch bands operating at wireless local area network band and X‐band. In addition, the proposed antenna has a compact size and omnidirectional radiation pattern, which is suitable for UWB communication applications. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1240–1244, 2014
CPW‐FED circularly polarized asymmetric square‐ring patch antenna for RFID applications
Authors: Li Xuehui , Ren Xueshi , Yin Yingzeng , Wu Jianjun , Li Zhaoxing
Published: March 2014

A novel coplanar‐waveguide (CPW)‐fed circularly polarized (CP) asymmetric square‐ring patch antenna for radio frequency identification applications is presented. The circular polarization radiation is obtained simply by loading an asymmetric square‐ring on the opposite side of the CPW‐fed structure. The asymmetric square‐ring consists of a square‐ring and two bevels, which greatly contributes to pure circular polarization characteristics. For the optimized antenna prototype, experimental results show that the 10‐dB return loss and the 3‐dB axial ratio bandwidths are 10.2% (2.29–2.54 GHz) and 6.9% (2.33–2.5 GHz), respectively, which agree well with the simulated results. Detailed design results of the proposed antenna have been studied by high frequency structure simulator and experiments. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1232–1235, 2014
A microwave switchable low‐noise power amplifier for an active backscatter tag
Authors: Prades Jeremie , Ghiotto Anthony , Taris Thierry , Regimbal Nicolas , Pham Jean‐Marie , Dupuy Victor , Kerherve Eric
Published: March 2014

This article reports the design of a switchable low‐noise power amplifier (LNPA) intended for an active backscatter tag used in microwave localization and positioning applications. Due to system specifications, the backscattering transponder requires an amplifier having both low‐noise and high‐output power characteristics at the same time. Low‐noise amplifier and PA design considerations are both taken into account to realize a single structure achieving the required performances. The proposed LNPA is operating in the frequency range of 4.5–5.8 GHz. It achieves a gain of 21 dB with a ripple of ±1 dB, a noise figure of less than 2.5 dB, and an output compression point at −1 dB of 11 dBm over the operational bandwidth. This structure can be switched on and off by a control signal to modulate the tag radar cross section and enable distance measurement. A packaged prototype of the LNPA was fabricated and measured. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1251–1255, 2014
Effizientere Bildverarbeitung
Authors: Heard Carlton
Published: March 2014

Heutzutage müssen produzierende Unternehmen bei steigender Qualität und Quantität immer kostengünstiger arbeiten, Roboter werden intelligenter und flexibler und die Automatisierung ist ein topaktuelles Thema, das von zahlreichen Ressourcen unterstützt wird. Die Bildverarbeitung spielt eine Schlüsselrolle bei diesen Trends und hat in den letzten zwei Jahrzehnten einen großen Aufschwung erfahren. Die Leistung von Bildverarbeitungsanwendungen war jedoch stets an die Fortschritte bei der CPU‐Geschwindigkeit gekoppelt. So konnte die Bildverarbeitung mit steigender CPU‐Frequenz immer komplexere Algorithmen bei höheren Kamerabildraten und Auflösungen ausführen. Doch im Vergleich zu den beinahe exponentiellen Wachstumsraten des vergangenen Jahrzehnts ist die Steigerung der CPU‐Leistung in letzter Zeit merklich abgeflaut.
Multidimensionale Analysedaten
Authors: Haschke Michael , Kanngießer Birgit
Published: March 2014

Analytische Methoden mit räumlicher und / oder zeitlicher Auflösung erzeugen multidimensionale Datensätze, für deren Darstellung es verschiedene Möglichkeiten gibt. Bei elementanalytischen Methoden wird häufig die räumliche Verteilung der Elemente dargestellt. Diese Daten enthalten in der Regel eine Vielzahl von Informationen. Deren Auswertung insbesondere durch Extraktion von speziellen Informationen und deren Interpretation ist eine komplexe Aufgabenstellung, die auch von der jeweiligen analytischen Problemstellung bestimmt wird. Die hier dargestellten Überlegungen schließen an den ersten Teil der Publikation an [1], in der die Einflüsse der verschiedenen Messparameter auf die Qualität von Verteilungsbildern diskutiert wurden. In diesem Teil werden wieder anhand von Messungen mit der Mikro‐Röntgenfluoreszenz (μ‐RFA) die unterschiedlichen Möglichkeiten der Datendarstellung vorgestellt und Beispiele für die Datenextraktion mittels Phasenanalyse sowie anderen chemometrischen und multivarianten Auswertemethoden diskutiert.
Photovoltaics literature survey (No. 110)
Authors: Shrestha Santosh
Published: March 2014

In order to help keep readers up‐to‐date in the field each issue of Progress in Photovoltaics will contain a list of recently published journal articles most relevant to its aims and scope. This list is drawn from an extremely wide range of journals, including IEEE Transactions on Electron Devices, Journal of Applied Physics, Applied Physics Letters, Progress in Photovoltaics and Solar Energy Materials and Solar Cells. To assist the reader, the list is separated into broad categories, but please note that these classifications are by no means strict. Also note that inclusion in the list is not an endorsement of a paper's quality. If you have any suggestions please email Santosh Shrestha at s.shrestha@unsw.edu.au.
Identification of proteins associated with ion homeostasis and salt tolerance in barley
Authors: Wu Dezhi , Shen Qiufang , Qiu Long , Han Yong , Ye Linzheng , Jabeen Zahra , Shu Qingyao , Zhang Guoping
Published: March 2014

Identification and characterization of proteins involved in salt tolerance are imperative for revealing its genetic mechanisms. In this study, ionic and proteomic responses of a Tibetan wild barley XZ16 and a well‐known salt‐tolerant barley cv. CM72 were analyzed using inductively coupled plasma‐optical emission spectrometer, 2DE, and MALDI‐TOF/TOF MS techniques to determine salt‐induced differences in element and protein profiles between the two genotypes. In total, 41 differentially expressed proteins were identified in roots and leaves, and they were associated with ion homeostasis, cell redox homeostasis, metabolic process, and photosynthesis. Under salinity stress, calmodulin, Na/K transporters, and H+‐ATPases were involved in establishment of ion homeostasis for barley plants. Moreover, ribulose‐1,5‐bisphosphate carboxylase/oxygenase activase and oxygen‐evolving enhancer proteins were significantly upregulated under salinity stress, indicating the great impact of salinity on photosynthesis. In comparison with CM72, XZ16 had greater relative dry weight and lower Na accumulation in the shoots under salinity stress. A higher expression of HvNHX1 in the roots, and some specific proteins responsible for ion homeostasis and cell redox homeostasis, was also found in XZ16 exposed to salt stress. The current results showed that Tibetan wild barley XZ16 and cultivated barley cultivar CM72 differ in the mechanism of salt tolerance.
Multiplex profiling of tumor‐associated proteolytic activity in serum of colorectal cancer patients
Authors: Yepes Diego , Costina Victor , Pilz Lothar R. , Hofheinz Ralf , Neumaier Michael , Findeisen Peter
Published: March 2014

Purpose

The monitoring of tumor‐associated protease activity in blood specimens has recently been proposed as new diagnostic tool in cancer research. In this paper, we describe the screening of a peptide library for identification of reporter peptides (RPs) that are selectively cleaved in serum specimens from colorectal cancer patients and investigate the benefits of RP multiplexing.

Experimental design

A library of 144 RPs was constructed that contained amino acid sequences of abundant plasma proteins. Proteolytic cleavage of RPs was monitored with MS. Five RPs that were selectively cleaved in serum specimens from tumor patients were selected for further validation in serum specimens of colorectal tumor patients (n = 30) and nonmalignant controls (n = 60).

Results

RP spiking and subsequent quantification of proteolytic fragments with LC‐MS showed good reproducibility with CVs always below 26%. The linear discriminant analysis and PCA revealed that a combination of RPs for diagnostic classification is superior to single markers. Classification accuracy reached 88% (79/90) when all five markers were combined.

Conclusions and clinical relevance

Functional protease profiling with RPs might improve the laboratory‐based diagnosis, monitoring and prognosis of malignant disease, and has to be evaluated thoroughly in future studies.
Defect studies on Ar‐implanted ZnO thin films
Authors: Schmidt Florian , Müller Stefan , Pickenhain Rainer , von Wenckstern Holger , Geburt Sebastian , Ronning Carsten , Grundmann Marius
Published: March 2014

Pulsed‐laser deposited ZnO thin films were implanted with Ar‐ions to generate intrinsic defects within the material. The defects created were analyzed by deep‐level and optical deep‐level transient spectroscopy. Deep‐level defects with thermal activation energies of 980 and appear after implantation. In order to study the annealing behavior of these defects, the implanted samples were isochronously annealed under an oxygen ambient of at temperatures ranging from 120 to . Both defects are annealed out after annealing for 1 h at .

(O)DLTS signal of an 40Ar‐implanted ZnO thin film under (a) dark condition and (b) under illumination with photons having a wavelength  of .
Computational methods of quantum reaction dynamics
Authors: Nyman Gunnar
Published: March 2014

In this article, I review some of the best available quantum dynamical approaches for studying bimolecular chemical reactions. Calculating the thermal rate constant is central in theoretical chemistry and there is a focus on this. I begin by motivating the need for quantum dynamics before giving a general overview. Thereafter, I give expressions for calculating thermal rate constants. This is followed by a brief description of time‐independent scattering calculations. Next comes a longer section on time‐dependent approaches including the time‐dependent wave packet approach, the multiconfigurational time‐dependent Hartree approach and ring polymer molecular dynamics. Finally, I make some concluding remarks. © 2014 Wiley Periodicals, Inc.
Comparison of vaginal mesh repair with sacrospinous vaginal colpopexy in the management of vaginal vault prolapse after hysterectomy in patients with levator ani avulsion: a randomized controlled trial
Authors: Svabik K. , Martan A. , Masata J. , El‐Haddad R. , Hubka P.
Published: March 2014

Objective

To compare the efficacy of two standard surgical procedures for post‐hysterectomy vaginal vault prolapse in patients with levator ani avulsion.

Methods

This was a single‐center, randomized interventional trial, of two standard surgical procedures for post‐hysterectomy vaginal vault prolapse: Prolift Total vs unilateral vaginal sacrospinous colpopexy with native tissue vaginal repair (sacrospinous fixation, SSF), during the period from 2008 to 2011. Entry criteria included at least two‐compartment prolapse, as well as complete unilateral or bilateral levator ani avulsion injury. The primary outcome was anatomical failure based on clinical and ultrasound assessment. Failure was defined clinically, according to the Pelvic Organ Prolapse Quantification system, as Ba, C or Bp at the hymen or below, and on translabial ultrasound as bladder descent to 10 mm or more below the lower margin of the symphysis pubis on maximum Valsalva maneuver. Secondary outcomes were evaluation of continence, sexual function and prolapse symptoms based on validated questionnaires.

Results

During the study period, 142 patients who were post‐hysterectomy underwent surgery for prolapse in our unit; 72 of these were diagnosed with an avulsion injury and were offered participation in the study. Seventy patients were randomized into two groups: 36 in the Prolift group and 34 in the SSF group. On clinical examination at 1‐year follow‐up, we observed one (3%) case of anatomical failure in the Prolift group and 22 (65%) in the SSF group (P < 0.001). Using ultrasound criteria, there was one (2.8%) failure in the Prolift group compared with 21 (61.8%) in the SSF group (P < 0.001). The postoperative POPDI (Pelvic Organ Prolapse Distress Inventory) score for subjective outcome was 15.3 in the Prolift group vs 21.7 in the SSF group (P = 0.16).

Conclusion

In patients with prolapse after hysterectomy and levator ani avulsion injury, SSF has a higher anatomical failure rate than does the Prolift Total procedure at 1‐year follow‐up. Copyright © 2014 ISUOG. Published by John Wiley & Sons Ltd.
Climate trends in the Arctic as observed from space
Authors: Comiso Josefino C. , Hall Dorothy K.
Published: March 2014

The Arctic is a region in transformation. Warming in the region has been amplified, as expected from ice‐albedo feedback effects, with the rate of warming observed to be ∼0.60 ± 0.07°C/decade in the Arctic (>64°N) compared to ∼0.17°C/decade globally during the last three decades. This increase in surface temperature is manifested in all components of the cryosphere. In particular, the sea ice extent has been declining at the rate of ∼3.8%/decade, whereas the perennial ice (represented by summer ice minimum) is declining at a much greater rate of ∼11.5%/decade. Spring snow cover has also been observed to be declining by −2.12%/decade for the period 1967–2012. The Greenland ice sheet has been losing mass at the rate of ∼34.0 Gt/year (sea level equivalence of 0.09 mm/year) during the period from 1992 to 2011, but for the period 2002–2011, a higher rate of mass loss of ∼215 Gt/year has been observed. Also, the mass of glaciers worldwide declined at the rate of 226 Gt/year from 1971 to 2009 and 275 Gt/year from 1993 to 2009. Increases in permafrost temperature have also been measured in many parts of the Northern Hemisphere while a thickening of the active layer that overlies permafrost and a thinning of seasonally frozen ground has also been reported. To gain insight into these changes, comparative analysis with trends in clouds, albedo, and the Arctic Oscillation is also presented.

This article is categorized under:

Paleoclimates and Current Trends > Modern Climate Change
Anaerobic ferrous oxidation by heterotrophic denitrifying enriched culture
Authors: Wang Ru , Zheng Ping , Xing Ya-Juan , Zhang Meng , Ghulam Abbas , Zhao Zhi-qing , Li Wei , Wang Lan
Published: March 2014

Heterotrophic denitrifying enriched culture (DEC) from a lab-scale high-rate denitrifying reactor was discovered to perform nitrate-dependent anaerobic ferrous oxidation (NAFO). The DEC was systematically investigated to reveal their denitrification activity, their NAFO activity, and the predominant microbial population. The DEC was capable of heterotrophic denitrification with methanol as the electron donor, and autotrophic denitrification with ferrous salt as the electron donor named NAFO. The conversion ratios of ferrous-Fe and nitrate-N were 87.41 and 98.74 %, and the consumption Fe/N ratio was 2.3:1 (mol/mol). The maximum reaction velocity and half saturation constant of Fe were 412.54 mg/(l h) and 8,276.44 mg/l, and the counterparts of N were 20.87 mg/(l h) and 322.58 mg/l, respectively. The predominant bacteria were Hyphomicrobium, Thauera, and Flavobacterium, and the predominant archaea were Methanomethylovorans, Methanohalophilus, and Methanolobus. The discovery of NAFO by heterotrophic DEC is significant for the development of wastewater treatment and the biogeochemical iron cycle and nitrogen cycle.
Nonlinear Transport of Positive Ions Below a Free Surface of Topological Superfluid $$^3$$He-B
Authors: Ikegami H. , Kono K.
Published: March 2014

The B phase of the topological superfluid $$^3$$

3

He ($$^3$$

3

He-B) shows many exotic phenomena at a surface as well as in bulk. In this article, we describe the first study of the nonlinear transport behavior of positive ions trapped below a free surface of $$^3$$

3

He-B measured at very low temperatures (below 300 $${\upmu }$$
μ
K), investigated for the purposes of observing the Landau critical velocity for pair breaking and finding a signature of the Majorana surface Andreev bound states. We observe that nonlinearity sets in at a velocity smaller than the Landau critical velocity for bulk pair breaking, and find that the nonlinear behavior does not depend on the depth of the trapped ions even though the depth is varied over the coherence length. The lack of depth dependence indicates that the nonlinear behavior does not reflect properties of the surface Andreev bound states. The onset of the nonlinearity at a velocity smaller than the bulk pair breaking velocity might be due to the inelastic scattering of bulk quasiparticles.
Bad Credit and Intergroup Differences in Loan Denial Rates
Authors: Ards Sheila D. , Ha Inhyuck Steve , Mazas Jose-Luis , Myers Samuel L.
Published: March 2014

Research has found wide disparities in loan denial rates among different racial/ethnic groups. Two competing explanations for these gaps arise. One argument is that these disparities result from underlying racial disparities in credit worthiness. A competing view is that the disparities arise from a pattern of racial discrimination among mortgage lenders. This paper adopts a stratification economics approach to evaluate these competing claims. Using Freddie Mac's Consumer Credit Survey dataset, we test the hypothesis that measures of discrimination disappear when one accounts for racial differences in credit scores. A novel contribution of the paper, built upon the premise that inter-group inequalities sustain themselves through self-fulfilling mechanisms, is to test the hypothesis that loan denials explain misperceptions of credit worthiness. We demonstrate that one cause of the appearance of poor credit risk among black applicants is that blacks with good credit risk underestimate their credit worthiness and apply for loans in lower numbers. Our findings suggest that even nondiscriminatory lending behavior has the unintended effect of screening out low-risk blacks and thereby yields higher denial rates among blacks. This in turn confirms prior beliefs about the poor credit of average black applicants. Much, but not all, of the racial disparity in loan outcomes can be explained by racial differences in credit scores and the resulting racial disparity in loan outcomes explains much of the racial difference in false perceptions about bad credit. Thus, a possible self-fulfilling mechanism remains within the credit market that perpetuates views about black bad credit.
Measuring Congregational Vitality: Phase 2 Development of an Outcome Measurement Tool
Authors: Bobbitt Linda
Published: March 2014

Since 2009 the Evangelical Lutheran Church in America has worked to develop a survey that can reliably measure qualitative aspects of congregational vitality. This study describes the development of a survey that focuses on key missional outcomes. Congregation members and pastors from 73 congregations were surveyed. Exploratory factor analysis identified important differences in the way pastors and lay people understand concepts like mission resulting in the creation of separate scales for pastors and lay people. These scales describe congregational vitality in five areas. Lay scales describe a congregation's connections with God, each other and the world while pastor scales describe their understanding of the congregation's inner strength and faith in action outside the congregation. For each respondent, individual scale scores were averaged to create congregational scale scores. Congregational scale scores were then compared with each congregation's annual statistics, key informant perceptions, and other items within the survey for validation. The result was a psychometrically sound instrument that helps congregations, synods and the denomination gain a more complete understanding of vitality. Implications for further research are discussed.
Mercadeo verde de una empresa dorada
Authors: Uribe-Saldarriaga Carlos Mario
Published: March 2014

El caso presenta la campa˜na de mercadeo realizada por Ecopetrol entre 2009 y 2012 para la introducciónen Colombia del diésel ultra bajo de azufre denominado diésel limpio. Se examina la campa˜na desde2 puntos de vista: el primero, el posicionamiento de Ecopetrol como una de las empresas más admiradasde Colombia, tanto por sus resultados financieros como por sus actividades en la responsabilidad socialempresarial; el segundo, desde las exigencias que se hacen al mercadeo ambiental en los países desarrollados,especialmente con respecto al lavado verde, teniendo en cuenta a la vez que Ecopetrol opera enun país en vía de desarrollo donde existe un menor avance en las exigencias ambientales hechas por losgrupos de interés.
Numerical study of the effect of surface wave on turbulence underneath. Part 2. Eulerian and Lagrangian properties of turbulence kinetic energy
Authors: Guo Xin , Shen Lian
Published: March 2014

The effect of the rapid distortion of a surface wave on the kinetic energy of turbulence underneath is studied based on the simulation data of Part 1 (Guo & Shen,J. Fluid Mech., vol. 733, 2013, pp. 558–587). In the Eulerian frame, Reynolds normal stresses, which contribute to turbulence kinetic energy, are found to vary with the wave phase. An analysis of their budgets shows that their variation is dominated not only by the normal production term representing the wave straining effect on wave–turbulence energy exchange, but also by pressure effects including the pressure–strain correlation and pressure transport terms. In the Lagrangian frame, the net energy transfer from the wave to turbulence is analysed. It is found to be mainly contributed by the mean Lagrangian effect and the correlation between the Lagrangian fluctuations of the wave and turbulence; the former plays a major role in the overall wave energy dissipation, while the latter is associated with the viscous effect of the wave surface and is appreciable in the near-surface region. Models for various terms in wave–turbulence energy flux are discussed. The decay time scale of swells in oceans estimated from our simulations compares well with the results in the literature.