bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microfluidic HPLC‐Chip devices with integral channels containing methylstyrenic‐based monolithic media
Authors: Robotti Karla M. , Yin Hongfeng , Brennen Reid , Trojer Lukas , Killeen Kevin 
Published: September 2009

AbstractPolyimide HPLC‐Chip devices containing poly(methylstyrene‐bis‐p‐vinylphenyl)ethane (MS/BVPE) stationary phase within the device channels and with wall attachment were prepared by thermally initiated free radical polymerization. The microfluidic devices were coupled to both UV and MS detectors. The potential of the MS/BVPE monolith as an alternative separation media within chip devices was investigated by side‐by‐side comparisons to particulate media within commercial devices. The chromatographic behavior of this stationary phase was comparable to particulate media for separations of proteins as the average peak width at half‐height was equal (6.2 s) for a separation within 8 min under gradient elution conditions. The ability to control the porosity characteristics of the MS/BVPE monolith with changes in polymerization time also extended its utility into small analyte (< 500 Da) applications, although more optimization is needed to match conventional RP media for these applications. The good mechanical stability of the MS/BVPE monolith within the microdevices enabled excellent run‐to‐run repeatability (%RSD retention time (⪇ 0.16) and chip‐to‐chip reproducibility (%RSD retention time (1.4). The use of this material within enrichment channels also shows its potential value in more complex work flows.
Determination of ethyl glucuronide in human serum by capillary zone electrophoresis and an immunoassay
Authors: Jung Balthasar , Caslavska Jitka , Thormann Wolfgang 
Published: September 2009

AbstractEthyl glucuronide (EtG) is a marker of recent alcohol consumption. For the optimization of the analysis of EtG by CZE with indirect absorbance detection, the use of capillaries with permanent and dynamic wall coatings, the composition of the BGE, and various sample preparation procedures, including dilution with water, ultrafiltration, protein precipitation, and SPE, were investigated. Two validated screening assays for the determination of EtG in human serum, a CZE‐based approach and an enzyme immunoassay (EIA), are described. The CZE assay uses a coated capillary, 2,4‐dimethylglutaric acid as an internal standard, and a pH 4.65 BGE comprising 9 mM nicotinic acid, ε‐aminocaproic acid and 10% v/v ACN. Proteins are removed via precipitation with ACN prior to analysis and the LOQ is 0.50 mg/L. The EIA is based upon commercial reagents which are promoted for the determination of urinary EtG. Krebs–Ringer solution containing 5% BSA is used as a calibration matrix. All samples are ultrafiltered prior to analysis of the ultrafiltrate on a Mira Plus analyzer. Assay calibration ranged between 0 and 2 mg/L and the upper reference limit was determined to be 0.05 mg/L. Both assays proved to be suitable for the analysis of samples from different individuals. For EtG levels above 0.50 mg/L, good agreement was observed for the comparison of the results of the two methods.
Rotenone induces apoptosis in MCF‐7 human breast cancer cell‐mediated ROS through JNK and p38 signaling
Authors: Deng Yea‐Tzy , Huang Hsiu‐Chen , Lin Jen‐Kun 
Published: September 2009

AbstractRotenone is an inhibitor of the mitochondrial electron transport chain complex I, resulting in the generation of reactive oxygen species (ROS). Rotenone has been shown to display anticancer activity through the induction of apoptosis in various cancer cells. However, the underlying mechanism is still not fully understood. Here, rotenone showed a strong growth inhibitory effect against human breast cancer MCF‐7 cells. DNA flow cytometric analysis, chromatin condensation, and poly (ADP‐ribose) polymerase (PARP) cleavage indicated rotenone actively induced apoptosis in MCF‐7 cells. The antiapoptotic protein, Bcl‐2, was decreased, whereas the apoptotic protein, Bax, was increased in a time‐dependent manner in rotenone‐induced apoptosis. Moreover, the treatment of rotenone in MCF‐7 cells caused the activation of c‐junN‐terminal kinase (JNK) and p38 mitogen‐activated protein kinases (MAPKs), and the inactivation of extracellular signal‐regulated protein kinase 1/2 (ERK1/2). The pharmacological inhibition of JNK and p38 MAPK revealed significant protection against rotenone‐induced apoptosis. Taken together, these results indicate rotenone may induce apoptosis through ROS and JNK/p38 MAPKs activation in MCF‐7 cells. © 2009 Wiley‐Liss, Inc.
Tunable band‐notched ultra wideband planar monopole antenna
Authors: Jeong Won‐Seok , Kim Dong‐Zo , Lim Won‐Gyu , Yu Jong‐Won 
Published: September 2009

AbstractA new tunable band‐notched ultra wideband planar monopole antenna is presented. The proposed antenna consists of a wideband planar monopole antenna, band‐notched resonating stubs, and varactor diodes. To generate the tunable band‐notched characteristic, we applied a short‐circuited quarter‐wavelength stub with a varactor diode to the wideband planar monopole antenna. We show the mechanism for notch characteristic using surface current distribution. This new approach is suitable for designing wideband antenna with narrow band interferer rejection characteristic. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2829–2832, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24744
The application of wide spectrum laser in noncontact vibration measurement
Authors: Wang Chao , Tang Huang , Xiao Qian , Jia Bo 
Published: September 2009

AbstractAn all‐fiber interferometer with wide spectrum laser source to measure vibration is introduced. The interference fringes envelop decay caused by wide spectrum laser source under large amplitude vibration is analyzed. The interference signals is retrieved through solving linear equations, and the wide spectrum distortion while demodulating the vibration signal is eliminated. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2858–2861, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24746
A highly linear and efficient three‐way Doherty amplifier using two‐stage GaN HEMT cells for repeater systems
Authors: Lee Yong‐Sub , Lee Mun‐Woo , Kam San‐Ho , Jeong Yoon‐Ha 
Published: September 2009

AbstractIn this article, we propose a highly linear and efficient three‐way Doherty amplifier using two‐stage GaN HEMT cells for repeater systems. The driving cells are used as the predistortion circuit to improve linearity as well as the gain stage. The main cells are optimized to achieve high efficiency at a large back‐off power. After gate bias optimization of the driving cells, the proposed three‐way Doherty amplifier with two‐stage cells shows highly linear and efficient performance. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2895–2898, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24748
A novel coding method with remodulation format used in a WDM‐PON to enhance extinction ratio
Authors: Huang Bo , Liang Yaoxiong , Qin Yi , Chi Nan 
Published: September 2009

AbstractWe report a new approach to eliminate the extinction ratio (ER) limitation in a wavelength division multiplexed passive optical network using RZ‐ASK/DPSK remodulation format corresponding to downstream/upstream signals, respectively. A novel precoding method can improve the ER tolerance from 6 to 13 dB for a 40‐Gb/s RZ‐ASK downstream and 622‐Mb/s DPSK upstream experimental transmission with <1 dB penalty. Rayleigh and stimulated Brillouin backscattering effects are simulated and analyzed in the deployment of a bidirectional 40G Ethernet PON probably using in practical application. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2994–2997, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24750
Biocompatibility study of beta tricalcium phosphate bioceramics and chitosan biopolymer and their use as phantoms for medical imaging applications
Authors: Augustine Robin , Kalappura Ullas G. , Laheurte Jean‐Marc , Mathew Kattackal T. 
Published: September 2009

AbstractBeta tricalcium phosphate (β‐TCP) bioceramics and chitosan biopolymers are used as biomedical implants because of their better biocompatibility and good bioresorption characteristics. As they are biomaterials, they have good interactions with microwave frequencies. β‐TCP and chitosan powder, films, pellets, and gel are prepared and studied at the S‐band microwave frequencies. Dielectric parameters such as dielectric constant, dielectric loss, conductivity, and S‐parameters are evaluated. Dielectric parameters of different forms of β‐TCP and chitosan show resemblance with that of human tissues. Hence, these materials can also be considered as potential phantoms for specific absorption rate measurements as well as in microwave imaging applications. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2923–2927, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24752
Super‐dense array emulating the human eye vision properties
Authors: Andrés‐García B. , García‐Muñoz E. , González‐Posadas V. , Segovia‐Vargas D. 
Published: September 2009

AbstractA super‐dense array based on the human eye photoreceptor physiology is proposed in this article. This study is a retinal model using individual dipole elements working at 20 GHz. The gain of the system in terms of the distance to the center is computed for applying it to an image. In this way, the human eye vision with elemental antennas is emulated. Also, an electromagnetic explanation has been given to the transmission of the information to the brain through the mutual coupling between elements. This article stands for checking the versatility of the human eye vision in the microwave range, for applying it to imaging arrays in the low‐Terahertz band. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2954–2959, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24754
Matching a Bluetooth headset antenna on a small system ground by using a conductive wire
Authors: Chou Jui‐Hung , Su Saou‐Wen 
Published: September 2009

AbstractIn this article, a simple, yet effective method for matching a compact planar inverted‐F antenna (PIFA) on a small system circuit board for Bluetooth headset applications is presented. The antenna is perpendicular to and extends along the top and right sides of the system ground, making it possible for the antenna to occupy almost no limited board space. Results have shown that by introducing a thin conductive wire soldered to the bottom corner of the system ground, good input matching over the 2400–2484 MHz band can easily be achieved for the PIFA mounted on a small ground of length less than a quarter wavelength at 2440 MHz. Radiation measurements of the proposed design in a real headset attached to a standard head phantom are also taken. Details of the obtained experimental and simulation results are given and discussed. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2802–2805, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24755
Design of Appollian‐like gasket fractal antenna with coplanar waveguide (CPW)‐fed
Authors: Kumar Raj , Tiwari Anupam 
Published: September 2009

AbstractThis article presents design of Appollian‐like gasket CPW‐fed fractal antenna. The antenna has been designed on FR4 substrate, εr = 4.3, with a thickness of 1.53 mm. The antenna has been fabricated and tested using VNA. The experimental result of this antenna shows the multiband behavior with the centre frequencies of 1.265, 4.66, and 7.8 GHz with impedance bandwidth of 50%, 17.5%, and 15%, respectively. The shift in first resonant frequency of antenna reveals the size reduction in comparison of solid equilateral triangular patch of 40 mm. The experimental radiation pattern of the antenna has been observed near to omnidirectional at lower frequency and like electric dipole antenna at higher frequency. This antenna can be used for short range wireless applications. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2836–2839, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24757
High‐efficiency outphasing transmitter using class‐E power amplifiers and asymmetric combining
Authors: Beltran Ramon , Raab Frederick H. , Velazquez Arturo 
Published: September 2009

AbstractChireix outphasing systems have been used successfully with power amplifiers (PAs) operating in class‐B and F. Class‐E PAs can produce high efficiency at microwave frequencies. However, the impedances produced by conventional outphasing are unsuitable for class E, resulting in poor efficiency and/or poor dynamic range. The asymmetric combining technique described here uses transmission lines or equivalent networks of different electrical lengths to position the impedance loci to provide good dynamic range while maintaining high efficiency. This in turn allows linear power amplification of amplitude‐modulated signals with high average efficiency. The concept is verified by a 25.7‐W peak output power transmitter that achieves an efficiency of 85% or better over an amplitude range of 10 dB. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2959–2963, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24758
Compact monopole antenna design for WLAN/UWB applications
Authors: Chung Wen‐Tsan , Lee Ching‐Her , Sim Chow‐Yen‐Desmond 
Published: September 2009

AbstractThis article presents a compact microstrip‐fed monopole antenna for application in WLAN (2.4–2.484 GHz) and UWB (3.1–10.6 GHz) bands. The radiating element of the proposed antenna consists of two arms that resonate at the fundamental frequencies of 2.45 and 3.5 GHz. A narrow slot is purposely embedded in the ground plane under the microstrip feed line to improve the impedance matching for the higher‐order modes of the two radiating arms for achieving an ultra‐wide‐band response. A prototype of the designed antenna is fabricated and measured, and satisfactory radiation properties were observed. The measured 10‐dB return‐loss bandwidth (maximum peak gain) of the 2.4‐GHz WLAN band is 0.17 GHz (4 dB), and that of the UWB band is 7.65 GHz (8.7 dB). In addition, a small group‐delay variation of less than 1 ns was observed in the UWB. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2874–2878, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24759
An investigation of wideband circular cylindrical sector dielectric resonator antenna with microstripline feed
Authors: Gopakumar C. , Yohannan Jaimon , Kalappura Ullas G. , Mathew K. T. 
Published: September 2009

AbstractThe article proposes a compact microstrip line fed dielectric resonator antenna with half split circular, cylindrical profile which is experimentally investigated. It shows that at optimum parameters, this low profile, small size antenna gives a wideband response similar to that of its full cylindrical counter part with moderate gain but at different frequency. The return loss and radiation pattern of the proposed antenna is measured and studied. The simulated and measured results verify that the proposed antenna offers an impedance bandwidth of 36.7% (from 3.24 to 4.70 GHz) and shows a radiation pattern which is relatively conical in shape with linear polarization. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2861–2865, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24762
Compact directional antenna for ultra wideband microwave imaging system
Authors: Abbosh A. M. , Bialkowski M. E. 
Published: September 2009

AbstractA planar antenna of tapered slot configuration for use in ultra wideband microwave imaging systems aimed for early breast cancer detection is presented. It is designed to operate across the ultra wideband frequency (3.1–10.6 GHz) in a liquid of a high dielectric constant that matches the electric properties of average breast tissues. It has a very compact size with overall dimensions of 0.9 cm × 1 cm. The antenna's ultra wideband performance even when it is close to the breast tissues and its distortionless response in the time domain make it suitable for the microwave imaging systems utilizing a short‐pulse radar technique. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2898–2901, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24764
Four FET active integrated microstrip antenna
Authors: Eccleston Kimberley W. 
Published: September 2009

AbstractIn this article, an active integrated microstrip antenna combining the output power of four field‐effect transistors (FETs) is described. The radiation pattern is similar to a four‐element phased array. The antenna is fed along its nonradiating edge thereby permitting the FETs to be connected directly to it. A prototype operating at 2.455 GHz demonstrates the feasibility of the antenna. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2997–3000, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24768
Capacitively loaded spiral‐shaped resonator for coplanar waveguide
Authors: Son Wang‐Ik , Lim Won‐Gyu , Kim Dong‐Zo , Lee Moon‐Que , Yu Jong‐Won 
Published: September 2009

AbstractA new coplanar waveguide bandstop filter using capacitively loaded spiral‐shaped resonator is proposed. The filter consists of a rectangular stepped coplanar waveguide and a spiral‐shaped slot in the center conductor. By embedding capacitor in the spiral‐shaped slot, tunable bandstop filter can be implemented, and tuning range from 1.5 to 3.0 GHz have been obtained. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 3001–3004, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24769
A miniaturized UWB antenna with improved stop‐band characteristics
Authors: Jang Joon‐Won , Hwang Hee‐Yong 
Published: September 2009

AbstractThis article presents a miniaturized UWB antenna with improved band‐rejection characteristics in 5 GHz band for ultra‐wideband applications. Using the symmetrical planes of a conventional circular‐slot (CS)‐UWB antenna and additional optimizing on its ground plane, slot angle, and feeding part we obtain a miniaturized UWB antenna with only 15.7% size of the conventional CS‐UWB antenna or 64% size of the conventional QCS‐UWB antenna. Adopting a small parasitic patch and a parasitic slot, simultaneously, to the miniaturized UWB antenna, we achieved the final miniaturized UWB antenna with excellent band‐rejection characteristics. We fabricated the proposed miniaturized UWB antenna on RF‐60A substrate. The measured bandwidth is from 3.0 GHz to 10.13 GHz for VSWR below 2.0 with excellent band‐rejection characteristics in 5.18–6.16 GHz band. The asymmetric antenna geometry by the miniaturization gives higher directivity in radiation pattern and slightly reduced gain compared to the conventional CS‐UWB antenna. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2842–2845, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24772
Small‐size printed monopole with a printed distributed inductor for pentaband WWAN mobile phone application
Authors: Chang Chih‐Hua , Wong Kin‐Lu 
Published: September 2009

AbstractIn this article, a small‐size printed monopole embedded with a printed narrow strip as a distributed inductor for application in the mobile phone to achieve GSM850/900/1800/1900/UMTS pentaband wireless wide area network operation is presented. With the printed distributed inductor, the fundamental (lowest) resonant mode of the proposed antenna can be effectively shifted to lower frequencies with a wide operating bandwidth, owing to the contributed inductance of the printed distributed inductor compensating for the increased capacitance resulting from the decreased resonant length of the monopole. In this study, the proposed antenna can be printed on the small no‐ground portion of size 14 × 40 mm2 on the main circuit board of the mobile phone, making it easy to fabricate at low cost and generally showing no thickness above the circuit board; the latter is very attractive for thin‐profile mobile phone applications. The proposed monopole antenna is studied in detail in this article. The results also show that the antenna is very suitable to be placed at the bottom of the mobile phone; in this case, the antenna meets the specific absorption rate limit for practical applications. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2903–2908, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24775
A novel CSRR‐based defected ground structure with dual‐bandgap characteristics
Authors: Fu Shu‐Hong , Tong Chuang‐Ming 
Published: September 2009

AbstractA new type of dumbbell‐shaped defected ground structure (DGS) is introduced in this article. Its dual‐bandgap characteristics are reported for the first time and can be adjusted by changing the dimension of complementary split‐ring resonators (CSRR) unit and gap. The dual bandstop filter using proposed DGS is designed and fabricated. Measured results show that there are two bandgaps centered at 3.35 GHz and 5.82 GHz, respectively. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2908–2910, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24776
Right isosceles triangular microstrip antenna with narrow L‐shaped slot
Authors: Sharma Vijay , Shekhawat S. , Saxena V. K. , Saini J. S. , Sharma K. B. , Soni B. , Bhatnagar D. 
Published: September 2009

AbstractThe radiation performance of a right isosceles triangular microstrip antenna (RITMA) having a narrow L slot is analyzed in free space. The designed antenna on glass epoxy FR‐4 substrate efficiently resonates at three different frequencies that lie in three frequency bands allotted by IEEE 802.16 working group for Wi‐Max systems. Two of these frequencies present excellent matching with inset feed network applied during this course of work. The bandwidth and directivity of proposed RITMA structure with ‘L’ shaped slot has also improved considerably in comparison to that of a simple RITMA geometry, although gain and efficiency of antenna are marginally decreased. The E and H plane co‐polar and cross‐polar radiation patterns of this antenna are also drawn. The measured and simulated results of this antenna are compared with that of a simple RITMA having identical dimensions to obtain important conclusions. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 3006–3010, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24781
Development of a K‐band FMCW phased array radar sensor with low complexity receiver based on antenna switching
Authors: Lee Moon‐Sik , Kim Yong‐Hoon 
Published: September 2009

AbstractA K‐band frequency‐modulated continuous wave phased array radar sensor with low‐complexity receiver based on antenna switching is developed. The radar sensor comprises a single transmitter, a single transmitting antenna, four receiving antennas, a single‐pole four‐throw switch, and a single receiving channel. The receiving antennas are switched to the single receiving channel periodically. The performance of the developed radar sensor is evaluated experimentally on the basis of the angle and range information obtained by using a beamforming method. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2848–2850, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24785