bluuebunny/crossref_metadata_2025 huggingface dataset:
Hepatitis B Testing And Access To Care Among Racial And Ethnic Minorities in Selected Communities Across the United States, 2009-2010
Authors: Hu Dale J. , Xing Jian , Tohme Rania A. , Liao Youlian , Pollack Henry , Ward John W. , Holmberg Scott D.
Published: January 2013

Hepatitis B virus (HBV) infection is widely prevalent among racial and ethnic minorities in the United States; however, few data have been available regarding HBV testing and referral to care for these populations. Using survey data collected in 2009-2010 from the Racial and Ethnic Approaches to Community Health (REACH) across the U.S., we assessed rates and determinants of hepatitis B testing and access to care in 28 minority communities in the U.S. Of 53,896 respondents, 21,129 (39.2%) reported having been tested for hepatitis B. Of the 1,235 who reported testing positive, 411 (33.3%) reported currently receiving specialty care. After controlling for demographic and socioeconomic characteristics, the likelihood of having been tested for hepatitis B and receiving care if infected was higher among males, non-English speaking persons, and those having health insurance compared to their counterparts. Compared to college graduates, respondents without a college education were less likely to get tested for hepatitis B. Conclusion: These data indicate that more than half of racial/ethnic minority persons in these communities had not been tested for hepatitis B, and only about one-half of those who tested positive had ever received treatment. More state and federal efforts are needed to screen racial/ethnic minorities, especially foreign-born persons, for HBV and link those with infection to care. (Hepatology 2013;53:856–862)
Simulating wetland impacts on stream flow in southern Africa using a monthly hydrological model
Authors: Hughes Denis A. , Tshimanga Raphael M. , Tirivarombo Sithabile , Tanner Jane
Published: January 2013

The processes that occur in wetlands and natural lakes are often overlooked and not fully incorporated in the conceptual development of many hydrological models of basin runoff. These processes can exert a considerable influence on downstream flow regimes and are critical in understanding the general patterns of runoff generation at the basin scale. This is certainly the case for many river basins of southern Africa which contain large wetlands and natural lakes and for which downstream flow regimes are altered through attenuation, storage and slow release processes that occur within the water bodies. Initial hydrological modelling studies conducted in some of these areas identified the need to explicitly account for wetland storage processes in the conceptual development of models. This study presents an attempt to incorporate wetland processes into an existing hydrological model, with the aim of reducing model structural uncertainties and improving model simulations where the impacts of wetlands or natural lakes on stream flow are evident. The approach is based on relatively flexible functions that account for the input–storage–output relationships between the river channel and the wetland. The simulation results suggest that incorporating lake and wetland storage processes into modelling can provide improved representation (the right results for the right reason) of the hydrological behaviour of some large river basins, as well as reducing some of the uncertainties in the quantification of the original model parameters used for generating the basin runoff. Copyright © 2013 John Wiley & Sons, Ltd.
Wear measurement of highly cross‐linked UHMWPE using a 7Be tracer implantation technique
Authors: Wimmer Markus A. , Laurent Michel P. , Dwiwedi Yasha , Gallardo Luis A. , Chipps Kelly A. , Blackmon Jeffery C. , Kozub Raymond L. , Bardayan Daniel W. , Gross Carl J. , Stracener Daniel W. , Smith Michael S. , Nesaraja Caroline D. , Erikson Luke , Patel Nidhi , Rehm Karl E. , Ahmad Irshad , Greene John P. , Greife Uwe
Published: January 2013

The very low wear rates achieved with the current highly cross‐linked ultrahigh molecular weight polyethylenes (UHMWPE) used in joint prostheses have proven to be difficult to measure accurately by gravimetry. Tracer methods are therefore being explored. The purpose of this study was to perform a proof‐of‐concept experiment on the use of the radioactive tracer beryllium‐7 (7Be) for the determination of in vitro wear in a highly cross‐linked orthopedic UHMWPE. Three cross‐linked and four conventional UHMWPE pins made from compression‐molded GUR 1050, were activated with 109 to 1010
7Be nuclei using a new implantation setup that produced a homogenous distribution of implanted nuclei up to 8.5 μm below the surface. The pins were tested for wear in a six‐station pin‐on‐flat apparatus for up to 7.1 million cycles (178 km). A Germanium gamma detector was employed to determine activity loss of the UHMWPE pins at preset intervals during the wear test. The wear of the cross‐linked UHMWPE pins was readily detected and estimated to be 17 ± 3 μg per million cycles. The conventional‐to‐cross‐linked ratio of the wear rates was 13.1 ± 0.8, in the expected range for these materials. Oxidative degradation damage from implantation was negligible; however, a weak dependence of wear on implantation dose was observed limiting the number of radioactive tracer atoms that can be introduced. Future applications of this tracer technology may include the analysis of location‐specific wear, such as loss of material in the post or backside of a tibial insert. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 101B: 423–429, 2013.
Root canal hydrophobization by dentinal silanization: Improvement of silicon‐based endodontic treatment tightness
Authors: Collart Dutilleul Pierre‐Yves , Fonseca Cesar Gaitán , Zimányi László , Romieu Olivier , Pozos‐Guillén Amaury J. , Semetey Vincent , Cuisinier Frédéric , Pérez Elías , Levallois Bernard
Published: January 2013

A new strategy to improve silicon‐based endodontic treatment tightness by dentine hydrophobization is presented in this work: root dentine was silanized to obtain a hydrophobic dentine‐sealer interface that limits fluid penetration. This strategy was based on the grafting of aliphatic carbon chains on the dentine through a silanization with the silane end groups [octadecyltrichlorosilane (OTS) and octadecyltriethoxysilane]. Dentine surface was previously pretreated, applying ethylenediaminetetraacetic acid and sodium hypochlorite, to expose hydroxyl groups of collagen for the silane grafting. Collagen fibers exposure after pretreatment was visible with scanning electron microscopy, and Fourier transform infrared (FTIR) spectroscopy showed their correct exposition for the silanization (amide I and II, with 1630, 1580, and 1538 cm‐1 peaks corresponding to the vibration of CO and CN bonds). The grafting of aliphatic carbon chains was confirmed by FTIR (peaks at 2952 and 2923 cm‐1 corresponding to the stretching of CH bonds) and by the increasing of the water contact angle. The most efficient hydrophobization was obtained with OTS in ethyl acetate, with a water contact angle turning from 51° to 109°. Gas and liquid permeability tests showed an increased seal tightness after silanization: the mean gas and water flows dropped from 2.02 × 10‐8 to 1.62 × 10−8 mol s‐1 and from 10.8 × 10−3 to 5.4 × 10−3 µL min−1, respectively. These results show clear evidences to turn hydrophilic dentine surface into a hydrophobic surface that may improve endodontic sealing. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2013.
Improvement of adhesive strength of segmented polyurethane on Ti–29Nb–13Ta–4.6Zr alloy through H2O2 treatment for biomedical applications
Authors: Hieda Junko , Niinomi Mitsuo , Nakai Masaaki , Kamura Hiroyuki , Tsutsumi Harumi , Hanawa Takao
Published: January 2013

The number of hydroxyl groups on a Ti–29Nb–13Ta–4.6Zr (TNTZ) alloy surface was controlled through H2O2 treatment for further improvement of the adhesive strength and durability against water of TNTZ/silane layers (SILs)/segmented polyurethane (SPU) composites. The effect of the terminal functional groups on the adhesive strength of SPU on TNTZ, and the adhesiveness of SPU on TNTZ against water was investigated. Three types of silane‐coupling agents were used to bind TNTZ and SPU: methacryloxypropyltrimethoxysilane (γ‐MPTS), aminopropyltriethoxysilane (APS), and mercaptopropyltrimethoxysilane (γ‐MPS). The adhesive strength of each composite was evaluated by shear bonding tests. The number of hydroxyl groups increases with an increase in treatment time at a H2O2 concentration of 5% (v/v). On the other hand, an increase from 5% (v/v) to 30% (v/v) in H2O2 concentration leads to a decrease in the number of hydroxyl groups on the TNTZ surface because at higher H2O2 concentrations, the reaction that consumes the hydroxyl groups is dominant. The shear bonding strength is doubled compared with the untreated TNTZ/SIL/SPU interface. Although the shear bonding strength decreases after immersion in water for 30 days when APS and γ‐MPS are used, TNTZ/γ‐MPTS/SPU composites exhibit good durability to water and maintain an equivalent shear bonding strength before immersion in water. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2013.
Preparation of a novel anorganic bovine bone xenograft with enhanced bioactivity and osteoconductivity
Authors: Cho Jung Sang , Kim Hyung‐Sup , Um Seung‐Hoon , Rhee Sang‐Hoon
Published: January 2013

A novel anorganic bovine bone xenograft with enhanced bioactivity and osteoconductivity was prepared by an ion substitution method using sodium hypochlorite. Bovine bone granules were defatted, washed, and then soaked in sodium hypochlorite solution at room temperature. Subsequently, the granules were dried and then heat‐treated at 1000°C with sodium hypochlorite. As a control, bovine bone granules were prepared with the same conditions but without sodium hypochlorite treatment. Phase, functional group, and elemental analyses by XRD, FTIR, and EPMA showed that the granules heat‐treated without and with sodium hypochlorite were pure hydroxyapatite and sodium‐chlorine‐bearing hydroxyapatite, respectively. After soaking in simulated body fluid (SBF) for 1 week, low crystalline hydroxyl carbonate apatite fully covered the surface of sodium‐chlorine‐bearing hydroxyapatite, whereas it formed little on the hydroxyapatite surface. After soaking in SBF and deionized water, ICP‐AES and IC analyses showed that the dissolutions of calcium, sodium, chlorine, and hydroxyl ions from sodium‐chlorine‐bearing hydroxyapatite notably increased compared with those from hydroxyapatite. This resultantly increased the ionic activity product of apatite in SBF and induced new formation of low crystalline hydroxyl carbonate apatite. The cytotoxicity test by BCA assay showed that there were no statistically significant differences between hydroxyapatite and sodium‐chlorine‐bearing hydroxyapatite. In addition, sodium‐chlorine‐bearing hydroxyapatite showed better osteoconductivity in the calvarial defects of New Zealand white rabbits within 4 weeks compared with that of hydroxyapatite. The results suggest that this novel anorganic bovine bone xenograft possesses encouraging potential for use as a bone grafting material due to better bioactivity and osteoconductivity than hydroxyapatite. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2013.
The P2Y13 receptor regulates extracellular ATP metabolism and the osteogenic response to mechanical loading
Authors: Wang Ning , Rumney Robin MH , Yang Lang , Robaye Bernard , Boeynaems Jean-Marie , Skerry Timothy M , Gartland Alison
Published: January 2013

ATP release and subsequent activation of purinergic receptors has been suggested to be one of the key transduction pathways activated by mechanical stimulation of bone. The P2Y13 receptor, recently found to be expressed by osteoblasts, has been suggested to provide a negative feedback pathway for ATP release in different cell types. Therefore, we hypothesized that the P2Y13 receptor may contribute to the mediation of osteogenic responses to mechanical stimulation by regulating ATP metabolism by osteoblasts. To test this hypothesis, wild-type (WT) and P2Y13 receptor knockout (P2Y13R−/−) mice were subject to non-invasive axial mechanical loading of the left tibiae to induce an osteogenic response. Micro-computed tomography analysis showed mechanical loading induced an osteogenic response in both strains of mice in terms of increased total bone volume and cortical bone volume, with the P2Y13R−/− mice having a significantly greater response. The extent of the increased osteogenic response was defined by dynamic histomorphometry data showing dramatically increased bone formation and mineral apposition rates in P2Y13R−/− mice compared with controls. In vitro, primary P2Y13R−/− osteoblasts had an accumulation of mechanically induced extracellular ATP and reduced levels of hydrolysis. In addition, P2Y13R−/− osteoblasts also had a reduction in their maximal alkaline phosphatase (ALP) activity, one of the main ecto-enzymes expressed by osteoblasts, which hydrolyzes extracellular ATP. In conclusion, deletion of the P2Y13 receptor leads to an enhanced osteogenic response to mechanical loading in vivo, possibly because of the reduced extracellular ATP degradation by ALP. The augmented osteogenic response to mechanical stimulation, combined with suppressed bone remodeling activities and protection from OVX-induced bone loss after P2Y13 receptor depletion as previously described, suggests a potential role for P2Y13 receptor antagonist-based therapy, possibly in combination with mechanical loading, for the treatment of osteoporosis.
Variation in tibial functionality and fracture susceptibility among healthy, young adults arises from the acquisition of biologically distinct sets of traits
Authors: Jepsen Karl J , Evans Rachel , Negus Charles H , Gagnier Joel J , Centi Amanda , Erlich Tomer , Hadid Amir , Yanovich Ran , Moran Daniel S
Published: January 2013

Physiological systems like bone respond to many genetic and environmental factors by adjusting traits in a highly coordinated, compensatory manner to establish organ-level function. To be mechanically functional, a bone should be sufficiently stiff and strong to support physiological loads. Factors impairing this process are expected to compromise strength and increase fracture risk. We tested the hypotheses that individuals with reduced stiffness relative to body size will show an increased risk of fracturing and that reduced strength arises from the acquisition of biologically distinct sets of traits (ie, different combinations of morphological and tissue-level mechanical properties). We assessed tibial functionality retrospectively for 336 young adult women and men engaged in military training, and calculated robustness (total area/bone length), cortical area (Ct.Ar), and tissue-mineral density (TMD). These three traits explained 69% to 72% of the variation in tibial stiffness (p < 0.0001). Having reduced stiffness relative to body size (body weight × bone length) was associated with odds ratios of 1.5 (95% confidence interval [CI], 0.5–4.3) and 7.0 (95% CI, 2.0–25.1) for women and men, respectively, for developing a stress fracture based on radiography and scintigraphy. K-means cluster analysis was used to segregate men and women into subgroups based on robustness, Ct.Ar, and TMD adjusted for body size. Stiffness varied 37% to 42% among the clusters (p < 0.0001, ANOVA). For men, 78% of stress fracture cases segregated to three clusters (p < 0.03, chi-square). Clusters showing reduced function exhibited either slender tibias with the expected Ct.Ar and TMD relative to body size and robustness (ie, well-adapted bones) or robust tibias with reduced residuals for Ct.Ar or TMD relative to body size and robustness (ie, poorly adapted bones). Thus, we show there are multiple biomechanical and thus biological pathways leading to reduced function and increased fracture risk. Our results have important implications for developing personalized preventative diagnostics and treatments.
γ‐Aminobutyric acid‐ρ expression in ependymal glial cells of the mouse cerebellum
Authors: Reyes‐Haro Daniel , González‐González María Alejandra , Pétriz Adriana , Rosas‐Arellano Abraham , Kettenmann Helmut , Miledi Ricardo , Martínez‐Torres Ataulfo
Published: January 2013

The ependymal glial cells (EGCs) from the periventricular zone of the cerebellum were studied to determine their distribution and the functional properties of their γ‐aminobutyric acid type A (GABAA) receptors. EGCs were identified by the presence of ciliated structures on their ventricular surface and their expression of glial fibrillary acidic protein (GFAP). Interestingly, diverse cell types, including neurons, astrocytes, and other types of glia, were identified in the subventricular zone by their current profiles. Electron microscopy showed ciliated cells and myelinated axons in this zone, but we found no collateral connections to suggest the presence of functional synapses. GABA‐mediated currents were recorded from EGCs in cerebellar slices from postnatal days 13 to 35 (PN13–PN35). These currents were blocked by TPMPA (a highly specific GABAAρ subunit antagonist) and bicuculline (a selective antagonist for classic GABAA receptors). Pentobarbital failed to modulate GABAA‐mediated currents despite the expression of GABAα1 and GABAγ2 subunits. In situ hybridization, RT‐PCR, and immunofluorescence studies confirmed GABAρ1 expression in EGCs of the cerebellum. We conclude that cerebellar EGCs express GABAρ1, which is functionally involved in GABAA receptor‐mediated responses that are unique among glial cells of the brain. © 2013 Wiley Periodicals, Inc.
Microwave‐assisted extraction of edible Cicerbita alpina shoots and its LC‐MS phenolic profile
Authors: Alexandru Lavinia , Pizzale Lorena , Conte Lanfranco , Barge Alessandro , Cravotto Giancarlo
Published: January 2013

BACKGROUND

Crude extracts obtained from the edible shoots of Cicerbita alpina using microwave‐assisted extraction have been qualitatively profiled by liquid chromatography coupled with an ion trap mass spectrometry detector and an electrospray ionization interface (LC/ESI‐MS3) for their phenolic content. The main challenge of the present investigation was to create a working strategy designed to obtain a rich phenolic profile despite the limited amount of starting plant material and phytochemical data available.

RESULTS

The best extraction conditions (temperature 90 °C; time 5 min; solvent methanol:water 50:50; sample weight 3 g) were achieved using a full factorial 24 experimental design. Fifteen compounds, including flavonoid conjugates and phenolic acid derivatives, were detected and tentatively identified. The total phenolic content varied from 93.58 mg g−1 gallic acid equivalents (GAE), for the cultivated plant to 10.54 mg g−1 GAE for the wild one, whereas the total flavonoid content varied from 145.00 mg g−1 rutin for the cultivated plant to 25.22 mg g−1 rutin for the wild one.

CONCLUSION

A total of 11 compounds are herein reported, for the first time, as coming from this plant source. © 2013 Society of Chemical Industry
Two‐photon excited fluorescence imaging of endogenous contrast in a mouse model of ovarian cancer
Authors: Watson Jennifer M. , Marion Samuel L. , Rice Photini F. , Utzinger Urs , Brewer Molly A. , Hoyer Patricia B. , Barton Jennifer K.
Published: January 2013

Background and Objective

Ovarian cancer has an extremely high mortality rate resulting from poor understanding of the disease. In order to aid understanding of disease etiology and progression, we identify the endogenous fluorophores present in a mouse model of ovarian cancer and describe changes in fluorophore abundance and distribution with age and disease.

Study Design/Materials and Methods

A mouse model of ovarian cancer was created by dosing with 4‐vinylcyclohexene diepoxide, which induces follicular apoptosis (simulating menopause), and 7,12‐dimethylbenz[a]anthracene, a known carcinogen. Imaging of ovarian tissue was completed ex vivo with a multiphoton microscope using excitation wavelength of 780 nm and emission collection from 405 to 505 nm. Two‐photon excited fluorescence images and corresponding histologic sections with selective stains were used to identify endogenous fluorophores.

Results

The majority of collected fluorescence emission was attributed to NADH and lipofuscin, with additional contributions from collagen and elastin. Dim cellular fluorescence from NADH did not show observable changes with age. Changes in ovarian morphology with disease development frequently caused increased fluorescence contributions from collagen and adipose tissue‐associated NADH. Lipofuscin fluorescence was much brighter than NADH fluorescence and increased as a function of both age and disease.

Conclusions

Our finding of NADH fluorescence patterns similar to that seen previously in human ovary, combined with the observation of lipofuscin accumulation with age and disease also seen in human organs, suggests that the findings from this model may be relevant to human ovarian disease. Increased lipofuscin fluorescence might be used as an indicator of disease in the ovary and this finding warrants further study. Lasers Surg. Med. 45: 155–166, 2013. © 2013 Wiley Periodicals, Inc.
The Incentives for Innovative Activity in the Managerial Firm
Authors: Kraft Kornelius
Published: January 2013

This paper discusses the incentives for innovation by a manager‐led firm. In particular, it is investigated how remuneration practices influence the choice of a risky project. In the first place, a dynamic model with uncertainty is used to determine the optimal employment level with exogenous growth and risk. In the second part of the paper, growth and risk are explained by R&D expenditures. Optimal investment expenditures for R&D are derived for (i) the profit‐maximizing firm and (ii) the managerial firm, where the manager receives a fixed salary as well as a variable share of profits. If risk neutrality is assumed, then no difference exists. However, if risk aversion is considered, the managerial firm will invest more into R&D than the owner‐led company. Size‐related salaries are an additional reason for higher expenditures of R&D by managers. Copyright © 2013 John Wiley & Sons, Ltd.
Wideband internal antenna with coupled feeding for 4G mobile phone
Authors: Zhao Guo‐Huang , Wang An‐Guo , Leng Wen , Chen Bin , Chen Hua
Published: January 2013

A wideband internal antenna that is composed of a coupled feeding part and four branch lines is presented.The proposed antenna can operate within two wide bands of 0.64–0.99 GHz and 1.65–2.85 GHz which cover 11 service bands including LTE 700/2300/2500, AMPS800, GSM900, DCS1800, PCS, UMTS, WiBro2350, ISM/Bluetooth, and WLAN for the 4G mobile phone. The antenna could be available not only for future 4G service but also for current 2G/3G services. This internal antenna is fabricated within the limits of a 65 × 11 × 7 mm3 volume and suitable for smart phones or personal digital assistant (PDA) applications. The measured results are in agreement with the simulation. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:513–516, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27341
Miniaturization of ring resonator bandpass filters using dielectric ceramic substrates
Authors: Huang Cheng‐Liang , Yang Wen‐Ruei , Huang Sen‐Hung
Published: January 2013

A compact bandpass filter is designed using stepped impedance ring resonators with zero‐degree feed structure.This compact bandpass filters using FR4 and high‐permittivity ceramic substrates (with respective dielectric constants of 4.5 and 13.46) are investigated. Using high Q, high permittivity dielectric ceramic materials as substrates, the filters demonstrate high selectivity, compact size, and can be applied in several microwave communication systems. An electromagnetic simulator is used to design the ring resonators, and to calculate the coupling coefficient of the basic coupling strictures. A precise planar bandpass filter with ceramic substrates has been fabricated using the screen printing technique. The responses of bandpass filters using FR4 (εr = 4.5, tan δ = 0.015) and Mg4Nb2O9 with 0.75 wt% Fe2O3 (εr = 13.46, tan δ = 0.00004) ceramic substrates are designed at a center frequency of 2.4 GHz with bandwidth of about 9%. The compact size, low‐loss, and performance of the filter are demonstrated in this article. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:660–663, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27346
A universal ring 0°/180° coupler for arbitrary power division
Authors: Park Myun‐Joo , Lee Byungje
Published: January 2013

A universal ring structure is presented for the 0°/180° coupler operation with arbitrary power division ratios. The ring circuit topology is investigated for the 0°/180° coupler operation based on the 4‐port admittance parameter analysis. The universal design equations are derived in terms of 4‐port admittance parameters of the coupler and the 2‐port branch parameters of the ring. The universal conditions for the coupler operation are presented in terms of the self and the mutual admittances of the ring. The universal ring topology under consideration is quite general with minimized circuit restrictions and the presented results are applicable to almost all types of ring coupler structures including the lumped as well as the distributed circuit implementations. As an example, the presented results for the universal ring are applied successfully to the design of uniform transmission line ring couplers with arbitrary values for the line impedances, electrical lengths, and the power division ratios. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:543–547, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27351
A 60‐GHz double‐balanced mixer with negative resistance compensation for direct up‐conversion using 90‐nm CMOS technology
Authors: Tsai Tzung‐Min , Lin Yo‐Sheng
Published: January 2013

A 60‐GHz double‐balanced mixer for direct up‐conversion using standard 90‐nm CMOS technology is reported.The up‐conversion mixer comprises a double‐balanced Gilbert cell with negative resistance compensation for conversion gain (CG) enhancement, a Marchand balun for converting the single local oscillator (LO) input signal to differential signal, and another Marchand balun for converting the differential radio‐frequency (RF) output signal to single signal. The mixer consumes 15.1 mW and achieves intermediate frequency (IF)‐port input return loss of −36.7 dB at 0.1 GHz, LO‐port input return loss of −9.9∼−19.1 dB, and RF‐port input return loss of −12.4∼−31.3 dB for frequencies 57∼64 GHz. At IF of 0.1 GHz, the mixer achieves maximum CG of 4.5 dB at RF of 60 GHz. The corresponding 3‐dB bandwidth of RF is 6.2 GHz (57.1∼63.3 GHz). The measured LO–RF isolation is 57.5 dB at RF of 60 GHz. In addition, the measured output 1‐dB compression point and input third‐order intermodulation point are −11.8 and −5 dBm, respectively, at RF of 60 GHz. These results demonstrate the proposed up‐conversion mixer architecture is very promising for 60‐GHz direct‐conversion transceiver applications. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:536–543, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27352
Dual current injection tunable SBG semiconductor laser with asymmetric π equivalent phase shift
Authors: Zhou Yating , Hou Jie , Chen Xiangfei
Published: January 2013

An asymmetric π equivalent phase shift sampled Bragg grating (SBG) semiconductor, which is consisted of two section with the same length but different sampling duty cycle 0.4 and 0.6, is investigated experimentally. By increasing the two injected currents of the studied laser from 15 mA to 120 mA, the lasing wavelength can be tuned by 2.1 nm. Combining selecting appropriate sampling period, the lasing wavelength of the laser can be tuned to meet the ITU‐T standard. Because of high yield and low cost, this type of SBG laser is very beneficial for designing and fabricating monolithically integrated wideband multiwavelength laser array for photonic integrated circuits in next generation fiber‐optic system. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:692–696, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27357
Design of an MOM diode‐coupled frequency‐selective surface
Authors: Kinzel Edward C. , Brown Robert L. , Ginn James C. , Lail Brian A. , Slovick Brian A. , Boreman Glenn D.
Published: January 2013

This article presents the design of a slot‐antenna‐based frequency selective surface coupled with metal‐oxide‐metal diodes integrated into the structure. This design takes advantage of a single self‐aligned patterning step using shadow evaporation. The structure is optimized at 10.6 μm to have less than 2% reflection with 70% of the incident energy dissipated into the oxide layer. Initial experimental results conducted with e‐beam lithography are presented. The fabricated structure is shown to produce a polarization sensitive unbiased DC current. This design will be useful for both infrared sensing and imaging as well as direct conversion of thermal energy. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:489–493, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27363
A dual‐band cross‐coupled oscillator using the varactor‐switching mode technique
Authors: Jang Sheng‐Lyang , Chen Yao‐Tsu , Lin Yu‐Sheng , Chang Chia‐Wei , Huang Jhin‐Fang
Published: January 2013

A dual‐band cross‐coupled oscillator is proposed to operate at 5 and 9 GHz. The oscillator consists of two cross‐coupled BiCMOS oscillators with shared series‐tuned LC‐tank. In the even‐mode, the series‐tuned LC‐tank takes no part in affecting the oscillation frequency, whereas in the odd‐mode, the series‐tuned LC‐tank plays the role in the oscillation frequency. The proposed oscillator has been implemented with the TSMC 0.18 μm SiGe BiCMOS technology and the core power consumption is 2.6 mW at the supply voltage of 0.7 V. The figure of merit is −192/−190 dBc/Hz at high‐/low‐band. The die area of the dual‐band VCO is 1.04 × 0.755 mm2. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:485–488, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27368
A wide bandwidth V‐band balanced resistive mixer with a miniature meandering balun
Authors: Huang Fan‐Hsiu , Lin Shao‐Wei , Ke Po‐Yu , Chiu Hsien‐Chin
Published: January 2013

We report a wideband resistive mixer fabricated in 0.15‐μm pHEMT for 60‐GHz frequency range, which includes an LO marchand balun and miniaturized IF lumped element balun.The measured conversion loss is less than 16 dB at RF bandwidth of 56–60 GHz with 2.4‐GHz fixed IF frequency. The LO‐to‐IF and RF‐to‐IF isolations are better than 30 dB. The input P1dB and input IIP3 are obtained as high as −2 and 7 dBm, respectively. The miniature technique makes passive components more compact and easier to be integrated with IC circuit design. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:547–550, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27371
Dual‐band VCO with composite right‐/left‐handed resonator
Authors: Jang Sheng‐Lyang , Liu You‐Wei , Chang Chia‐Wei , Hsue Ching‐Wen
Published: January 2013

This article proposes a high‐performance CMOS voltage‐controlled oscillator (VCO) implemented with composite right‐/left‐handed nonmobius‐connected LC‐rings to provide dual‐band differential outputs.The VCO consists of two cross‐coupled sub‐VCOs sharing series‐LC resonators. nMOSFET switches are used to control high‐ and low‐band outputs. The proposed VCO has been implemented with the TSMC 0.18 μm SiGe BiCMOS technology. The die area of the VCO is 1.16 × 1.12 mm2. With the switch on, the odd‐mode VCO operates at the high‐frequency 6 GHz band, and when the switch is off, the even‐mode VCO operates at the low‐frequency 4 GHz band. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:468–471, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27375
A 4.6‐mW 45‐GHz compact‐size darlington‐pair LC‐VCO IN 0.18‐μm cmos technology
Authors: Chiou H.‐K. , Chou and H.‐T.
Published: January 2013

This work proposes a 45‐GHz Darlington‐pair voltage‐controlled oscillator (VCO) in 0.18‐μm CMOS process. The Darlington‐pair transistors achieve a 10.3‐GHz higher unit gain cutoff frequency (fT) and lower negative resistance than those obtained in single MOS counterpart. This feature lowers the minimum current to start oscillation and hence reduces the power consumption in millimeter‐wave frequency regime. Meanwhile, a high‐Q straight transmission line is used to replace the inductor of the VCO resonator and achieves a good phase noise of −106.3 dBc/Hz at 10 MHz offset. The achieved figure‐of‐merit is −172.7 dBc/Hz while consumes a low direct current (DC) power consumption of 4.6 mW from a 1.5 V supply. The chip size including all pads is 0.19 mm2. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:648–652, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27380
Design of high efficiency rectifier at 2.45 GHz using parasitic canceling circuit
Authors: Kim Jungsik , Jeong Jinho
Published: January 2013

In this article, high efficiency rectifiers using parasitic canceling circuits are presented at 2.45 GHz. Input matching circuit and DC filter, which are the basic sub‐blocks of rectifiers, are designed for high efficiency operation. Then, the parasitic canceling circuit is designed and inserted between the rectifying diode and DC filter such that the parasitic elements of the diode is properly canceled out to minimize the harmonic generations and maximize the efficiency. For this purpose, the equivalent circuit of the diode is extracted, and the impedances seen by the intrinsic diode resistance are investigated at harmonic frequencies. To verify the suggested idea, two rectifiers with parasitic canceling circuits are demonstrated at 2.45 GHz, that is, low power rectifier (LP rectifier) which is optimally designed for low input power (lower than 0 dBm), and high power rectifier (HP rectifier) for high input power (higher than 0 dBm). The measurement of LP rectifier shows efficiency of 60% at the input power of 0 dBm. The HP rectifier achieves the maximum efficiency of 72% at the input power of 10 dBm. Both results belong to the excellent performance among the reported rectifiers at the same frequency. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:608–611, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27381
Novel dual‐mode circular patch bandpass filter using CSRR slot‐type perturbation
Authors: Shi Xinrong , Liu Yuan'an , He Qing , Gu Liangjie , Liu Hongtao Zhang Fang , Liu Kaiming
Published: January 2013

A slot‐type complement split‐ring resonator (CSRR) as a new type of perturbation element for dual‐mode circular patch resonator is proposed in this letter.The slot‐type CSRR used in the patch resonator perturbs the field distributions of circular patch resonators and excites degenerate modes. By changing the orientations of the CSRRs, coupling characteristics can be adjusted. The proposed dual‐mode bandpass filters are designed, fabricated, and measured. The simulation results of proposed bandpass filter are in good with the measurement ones. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:666–670, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27386
Millimeter‐wave phase shifter based on waveguide‐mounted RF‐MEMS
Authors: Psychogiou Dimitra , Li Yunjia , Hesselbarth Jan , Kühne Stephane , Peroulis Dimitrios , Hierold Christofer , Hafner Christian
Published: January 2013

A continuously variable transmission type W‐band phase shifter based on a single pole bandpass filter tuned by MEMS actuated fingers is reported. Tuning is achieved by means of two half‐wavelength long conductive fingers that synchronously rotate upwards in an antiparallel fashion. The fingers deflection results in a distributed variable shunt capacitance which in turn leads to a variable analog phase shift. For an applied DC bias voltage between 0 and 26 V, the transmission phase can be continuously varied up to 46.4° at a frequency of 106 GHz with an insertion loss of less than 3.4 dB. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:465–468, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27390
Optical generation of microwave passband signals
Authors: Dastmalchi Mansour , LaRochelle Sophie
Published: January 2013

We investigate generation of microwave passband signals with a tunable central frequency using optical up‐conversion. We consider systems without and with optical fiber transmission links. The technique performs photodetection of optically filtered gain switched laser pulses. Using appropriate electrical filters, we demonstrate up‐conversion centered at 25, 35, and 45 GHz. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:656–660, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27392
A 218‐GHz second‐harmonic multiquantum well GaAs‐based planar Gunn diodes
Authors: Khalid A. , Li Chong , Papageorgiou V. , Pilgrim N. J. , Dunn G. M. , Cumming D. R. S.
Published: January 2013

We present a multiquantum‐well channel GaAs‐based planar Gunn diode. By introducing extra channels, the output RF power has been significantly improved compared to single‐channel GaAs‐based planar Gunn diodes. For a 1.14 μm length and 60 μm wide device, the highest power achieved was approximately −4 dBm operating in fundamental mode at 109 GHz, and −26.6 dBm at its second harmonic at 218 GHz. The DC‐to‐RF conversion efficiency was ∼0.3% for the fundamental mode of oscillation. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:686–688, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27393
Measurement of active power using fiber bragg grating and a piezo‐electric transducer
Authors: Cheng Chin‐Hsing , Chang Min‐Chih , Liu Wen‐Fung
Published: January 2013

This article develops an optical fiber sensor using fiber Bragg grating (FBG) and a piezo‐electrical transducer (PZT) to measure active power.Mounting an FBG on a PZT bar, a dynamic strain simulator was constructed. The equivalent voltage produced by active power applied to the PZT was converted to the dynamic variation of the FBG Bragg wavelength. The active power was attained by measuring the changing value of the wavelength. Thus, the sensor can be used to measure active power without the use of a traditional power meter. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:682–686, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27394
Compact configurations of hexagonal microstrip antennas
Authors: Ray K. P. , Pandey M.D. , Rashmi R. , Duttagupta S. P.
Published: January 2013

This article proposes compact configurations of hexagonal microstrip antennas (HMSA). The hexagonal microstrip antenna is modified by shorting along the zero potential line, perpendicular to the feed axis resulting in shorted half‐hexagonal and quarter‐HMSA for the two feed configurations along X and Y axes. The fundamental principle is to keep the field distribution same so that the resonance frequency remains unaltered while achieving a compact footprint. The area reduces by a factor of four, for the quarter patch, while maintaining approximately the same resonance frequency. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:604–608, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27396
A slot antenna with magnetoelectric elements
Authors: Petrov Roman V. , Murthy Devata V. B. , Sreenivasulu Gollapudi , Srinivasan Gopalan
Published: January 2013

A ferrite–ferroelectric bilayer is used in a slot antenna for static magnetic and electric field control of the radiation characteristics of the antenna. A π‐type slot antenna with the resonance frequency ranging from 1.5 to 2.7 GHz, depending on the slot length, is studied. A bilayer of yttrium iron garnet (YIG) on gadolinium gallium garnet bonded to lead zirconate titanate (PZT) is used as the magnetoelectric element. Under a static magnetic field H corresponding to the ferromagnetic resonance in the YIG film, a substantial increase in the power transmitted by the antenna is measured. A dc electric field applied to PZT results in a phase shift of the radiated signal, by 220° for 200 V. The radiation patterns of the antenna show directional characteristics. The demonstrated electric and magnetic field control of antenna characteristics is of interest for applications in phased arrays and beam‐forming antennas. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:533–535, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27398
Manifestations of interpersonal dependency and depressive subtypes in outpatient psychotherapy patients
Authors: Huprich Steven , Rosen Alexandra , Kiss Andrea
Published: January 2013

The present study investigated the relationship between normative and pathological dependency and anaclitic and introjective depressive experiences among 71 patients participating in outpatient psychotherapy at a university‐based psychology clinic. We examined the interrelationships among the Relationship Profile Test subscales, the Depressive Experiences Questionnaire subscales and the Outcome Questionnaire‐45.2. Results indicated that destructive overdependence was positively correlated with anaclitic and introjective depression and negatively correlated with overall perceptions of mental health. Dysfunctional detachment was positively correlated with introjective depression and negatively correlated with generalized perceptions of one's own mental health. Healthy dependency was negatively correlated with introjective depression and positively correlated with mental health. These results not only support the construct validity of the Relationship Profile Test but also shed light on a link between depression, dependence and self‐criticism. Copyright © 2013 John Wiley & Sons, Ltd.
Psychiatric manifestations, personality traits and health‐related quality of life in cancer of unknown primary site
Authors: Hyphantis Thomas , Papadimitriou Ilias , Petrakis Dimitrios , Fountzilas George , Repana Dimitra , Assimakopoulos Konstantinos , Carvalho André F. , Pavlidis Nicholas
Published: January 2013

Objective

Psychiatric manifestations and personality traits are known to influence cancer patients. We aimed to assess psychological distress symptoms, psychosocial factors and health‐related quality of life (HRQoL) in cancer of unknown primary site (CUP) and to test whether these parameters differ between CUP and Metastatic (MKPC) or Non‐Metastatic Known Primary Cancers (N‐MKPC) after controlling for demographics and clinical variables.

Methods

In this cross‐sectional study, we recruited 50 CUP, 264 N‐MKPC and 52 MKPC participants. We assessed depressive symptoms (Center for Epidemiologic Studies‐Depression [CES‐D]), psychological distress symptoms (Symptom Distress Checklist‐90 Revised), sense of coherence (SOC), ego defense mechanisms (Life Style Index) and HRQoL (World Health Organization Quality of Life Instrument, Short Form).

Results

The prevalence of clinically significant depressive symptoms (CES‐D ≥ 23) was 40.0% in CUP, 28.8% in MKPC and 23.5% N‐MKPC (p = 0.037). Multivariate logistic regression analysis showed that N‐MKPC patients were 5 times less likely (p = 0.028) and MKPC patients 3.3 times less likely (p = 0.05) to be assessed with probable depression compared with CUP patients after controlling for the major demographic and clinical variables studied. CUP patients presented also higher levels of somatization, anxiety and depressive symptoms; they also had more impaired Physical (p = 0.005), Mental (p = 0.041) and Social Relations (p = 0.044) HRQoL, along with lower scores on SOC and intellectualization defense and higher scores on repression defense, compared with MKPC and N‐MKPC patients.

Conclusions

These findings suggest that psychiatric manifestations are frequent in CUP, and the patients' resources to cope with the burden of their illness are limited. Attention to CUP patients' psychological distress and coping resources and capacities may enable oncologists to identify and manage modifiable aspects of HRQoL. Copyright © 2013 John Wiley & Sons, Ltd.
Ridge waveguide InGaN/GaN quantum dot edge emitting visible lasers
Authors: Banerjee Animesh , Frost Thomas , Jahangir Shafat , Stark Ethan , Bhattacharya Pallab
Published: January 2013

Blue‐emitting and green‐emitting laser heterostructures were grown by molecular beam epitaxy, incorporating InGaN/GaN quantum dots as the active medium, with a measured quantum efficiency of 60% on n‐GaN bulk substrates. These quantum dots exhibit no S‐shape in the photoluminescence peak wavelength as a function of temperature, as typically found in comparable quantum well devices. The lasers were characterized by a threshold current density, Jth, of 930 A/cm2 under pulsed bias, with a differential efficiency of 13.9%, and a wall plug (power conversion) efficiency of 0.4% at 1050 A/cm2. Green‐emitting quantum dot lasers have Jth = 935 A/cm2. The lasers were also characterized by their modal properties through near field imaging (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth process and morphology of three‐dimensional GaSb islands on Ga/Si(111)
Authors: Hara Shinsuke , Machida Ryuto , Yoshiki Keisuke , Irokawa Katsumi , Miki Hirofumi , Kawazu Akira , Fujishiro Hiroki I.
Published: January 2013

The growth process and morphology of three‐dimensional GaSb islands grown on a Ga/Si(111)‐√3 × √3 reconstructed surface have been studied by ultrahigh‐vacuum scanning tunneling microscopy and non‐contact atomic force microscopy. Faceted GaSb islands with a density of 1011 cm−2 are formed on Ga/Si(111) in multilayer growth at 350 °C. Hexagonal‐ and pyramid‐shaped islands are formed at 400 °C. Dome‐shaped islands, which are similar to the islands grown on clean Si(111), are only formed at 450 °C. The growth morphology of GaSb islands varies depending on the atomic species terminated on Si(111) and the growth temperature. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Pycnogenol® Supplementation Improves Health Risk Factors in Subjects with Metabolic Syndrome
Authors: Belcaro G. , Cornelli U. , Luzzi R. , Cesarone  , Dugall M. , Feragalli B. , Errichi S. , Ippolito E. , Grossi M. G. , Hosoi M. , Cornelli M. , Gizzi G.
Published: January 2013

This open, controlled study evaluated the effects of 6 month supplementation with Pycnogenol® maritime pine bark extract on health risk factors in subjects with metabolic syndrome. Pycnogenol® was used with the aim of improving risk factors associated with metabolic syndrome, central obesity, elevated triglycerides (TG), low HDL cholesterol, high blood pressure and fasting blood glucose. Sixty‐four subjects (range 45–55 years) presenting with all five risk factors of metabolic syndrome were included, and Pycnogenol® was administered for 6 months. A group of 66 equivalent subjects were followed up as controls. In the 6‐month study Pycnogenol® supplementation 150 mg/day decreased waist circumference, TG levels, blood pressure and increased the HDL cholesterol levels in subjects. Pycnogenol lowered fasting glucose from baseline 123 ± 8.6 mg/dl to 106.4 ± 5.3 after 3 months and to 105.3 ± 2.5 at the end of the study (p < 0.05 vs controls). Men's waist circumference decreased with Pycnogenol from 106.2 ± 2.2 cm to 98.8 ± 2.3 cm and to 98.3 ± 2.1 after 3 and 6 months. Women's waist decreased from 90.9 ± 1.6 cm to 84.6 ± 2.1 cm and to 83.6 ± 2.2 cm after 3 and 6 months. Both genders waist circumference reduction was significant as compared to controls at both time points. In addition, plasma free radicals decrease in the Pycnogenol group was more effective than in the control group (−34.6%; p < 0.05). In conclusion, this study indicates a role for Pycnogenol® for improving health risk factors in subjects with metabolic syndrome. Copyright © 2013 John Wiley & Sons, Ltd.