bluuebunny/crossref_metadata_2025 huggingface dataset:
Axillary reverse mapping with indocyanine fluorescence imaging in patients with breast cancer
Authors: Noguchi Masakuni , Yokoi Miki , Nakano Yasuharu
Published: January 2010

Background

The ARM technique was proposed to prevent arm lymphedema after ALND and/or SLN biopsy. However, several problems remain to be resolved in the practical application of this technique.

Methods

The fluorescent ARM nodes and/or lymphatics were identified using a fluorescence imaging system with subdermal injection of indocyanine green into the upper limb. ALND was performed in patients with clinically involved nodes, and the ARM nodes were separately removed during ALND. SLN biopsy was performed in patients with clinically uninvolved nodes. If SLN was positive, ALND was performed with removal of ARM nodes. Otherwise, identified ARM nodes were preserved unless they were the same as SLN.

Results

ARM nodes and/or lymphatics were identified in 7 (88%) of 8 patients who underwent ALND, whereas they were identified in 9 (75%) of 12 patients who underwent SLN biopsy alone. ARM nodes were involved with tumors in 3 (43%) of the former patients, and SLN was the same as the ARM node in 2 (14%) of 14 patients who underwent SLN biopsy.

Conclusions

Fluorescence imaging was sensitive for identification of ARM nodes and/or lymphatics. However, further studies are needed before efforts to preserve these nodes can be safely implemented. J. Surg. Oncol. 2010; 101:217–221. © 2010 Wiley‐Liss, Inc.
A bio‐analytical hydrophilic interaction LC‐MS/MS method for the simultaneous quantification of omeprazole and lansoprazole in human plasma in support of a pharmacokinetic omeprazole study in children
Authors: De Smet Julie , Boussery Koen , De Cock Pieter , De Paepe Peter , Remon Jean‐Paul , Van Winckel Myriam , Van Bocxlaer Jan
Published: January 2010

A hydrophilic interaction LC method with MS/MS was developed and validated for the simultaneous quantification of omeprazole and lansoprazole in human plasma. Chromatographic separation was achieved on a Betasil silica column using a high organic mobile phase (eluent A: ACN/formic acid 997.5:2.5 v/v; eluent B: water/formic acid 997.5:2.5 v/v) and gradient elution. The mass spectrometer was operated in the Multiple Reaction Monitoring mode. Prior to chromatography, liquid–liquid extraction with ethyl acetate was used and the organic layer was diluted with ACN, allowing direct injection on column. The method showed acceptable linearity, high precision (RSD%<10.5%), accuracy (88.9–109.3%) and selectivity in the two concentration ranges studied: 1.5–100 and 5–2000 ng/mL. The LOQ was established at 1.5 and 5 ng/mL for the two concentration ranges. Lack of variability in matrix effects was demonstrated and mean extraction recovery for omeprazole and lansoprazole was determined in the low (56.3–67.7%) and high (45.3–44.3%) concentration range, respectively. Additionally, plasma samples were found to be stable after three freeze–thaw cycles and for at least 15 h after extraction. This assay was successfully applied to a pharmacokinetic omeprazole study in children with cerebral palsy and mental retardation.
Preparation of sub‐micron skeletal monoliths with high capacity for liquid chromatography
Authors: Yao Chunhe , Qi Li , Yang Gengliang , Wang Fuyi
Published: January 2010

A novel kind of poly(glycidyl methacrylate‐co‐ethylene glycol dimethacrylate)‐based monolithic column was developed for LC by directing supramolecular self‐assembly of high internal phase emulsion. Mercury intrusion porosimetry characterization and scanning electron microscope pictures showed that these monoliths presented micrometer‐sized throughpores, unique sub‐micron skeletons and relatively large specific surface area. Additionally, porosity of monoliths could be adjusted while skeletons remained in the size range of 100.0–1000.0 nm. The new monoliths demonstrated not only better column efficiency, but also larger binding capacity. Dynamic binding capacity for protein (BSA) was evaluated to be 42.5 mg/mL, above two times higher than that of the general monoliths (19.1 mg/mL) and higher than that of commercial “Convective Interaction Media” monolithic columns (30.0 mg/mL). Moreover, their chromatographic behaviors were also evaluated in detail by chemical stability and swelling characterization of the monolithic column. Separation of proteins mixture (cytochrome c, myoglobin, ribonuclease A, lysozyme and BSA) on the monolith was achieved within 4 min at velocity of 1440.0 cm/h. Those unique properties made the novel monolithic column a promising alternative to commercially available monolithic supports in LC applications.
Influence of stationary phase chemistry and mobile‐phase composition on retention, selectivity, and MS response in hydrophilic interaction chromatography
Authors: Fountain Kenneth J. , Xu Jane , Diehl Diane M. , Morrison Damian
Published: January 2010

A comprehensive retention and selectivity characterization of several hydrophilic interaction chromatography (HILIC) stationary phases was performed with 28 test probes in order to study the influence of particle type, surface chemistry, and mobile‐phase pH on chromatographic retention, selectivity, and MS response. Selectivity differences were compared for columns operated at both low and high pH, while ESI‐MS was used to study the effects of mobile‐phase pH on signal response. Additionally, acetone was explored as a potential alternative to ACN as the weak HILIC solvent. Moderate differences in selectivity were observed on the same column operated at different pH, mostly due to acidic compounds. In addition, the MS response increased when a high pH mobile phase was used, particularly for analytes that were ionized with negative ESI‐MS. Even larger selectivity differences were observed for different stationary phases evaluated with the same mobile phase. Acetone was not a suitable replacement for ACN in routine HILIC separations due to differences in selectivity and MS response. Finally, the data from this study were used to establish guidelines for rapid HILIC method development of polar compounds, which is demonstrated with a mixture of histidine dipeptides and organophosphonate nerve agent metabolites.
Kinetics and mechanisms of OH‐initiated oxidation of small unsaturated alcohols
Authors: Takahashi Kenshi , Hurley Michael D. , Wallington Timothy J.
Published: January 2010

Smog chamber relative rate techniques were used to measure rate coefficients of (5.00 ± 0.54) × 10−11, (5.87 ± 0.63) × 10−11, and (6.49 ± 0.82) × 10−11cm3molecule−1s−1in 700 Torr air at 296 ± 1 K for reactions of OH radicals with allyl alcohol, 1‐buten‐3‐ol, and 2‐methyl‐3‐buten‐2‐ol, respectively; the quoted uncertainties encompass the extremes of determinations using two different reference compounds. The OH‐initiated oxidation of allyl alcohol in the presence of NOxgives glycolaldehyde in a molar yield of 0.85 ± 0.08; the quoted uncertainty is two standard deviations. Oxidation of 2‐methyl‐3‐buten‐2‐ol gives acetone and glycolaldehyde in molar yields of 0.66 ± 0.06 and 0.56 ± 0.05, respectively. The reaction of OH radicals with allyl alcohol, 1‐buten‐3‐ol, and 2‐methyl‐3‐buten‐2‐ol proceeds predominately via addition to the >CCH2double bond with most of the addition occurring to the terminal carbon. © 2010 Wiley Periodicals, Inc. Int J Chem Kinet 42: 151–158, 2010
The relationship between trusting beliefs and Web site loyalty: The moderating role of consumer motives and flow
Authors: Gupta Reetika , Kabadayi Sertan
Published: January 2010

This research (1) examines how specific consumer motives (i.e., goal‐directed: searching for information, experiential: browsing for recreation) influence the trusting belief–loyalty relationship at a Web site in a distinct manner and (2) investigates how the online flow experience in each of the motive states strengthens or weakens the trusting belief–loyalty relationship. The results suggest that for consumers with an experiential motive, benevolence‐ and integrity‐related beliefs are the key drivers of loyalty, while ability‐related beliefs do not drive loyalty. On the other hand, for consumers with a goal‐directed motive, the ability‐ and integrity‐related beliefs are the key drivers of loyalty, while benevolence‐related beliefs are not influential. Further, this research illustrates that when consumers with an experiential motive experience a high level of flow, the impact of trusting beliefs on loyalty weakens. However, for consumers with a goal‐directed motive, trusting beliefs continue to exert the same impact on loyalty across both high and low levels of flow. ©2010 Wiley Periodicals, Inc.
Long‐term follow‐up of DYT1 dystonia patients treated by deep brain stimulation: An open‐label study
Authors: Cif Laura , Vasques Xavier , Gonzalez Victoria , Ravel Patrice , Biolsi Brigitte , Collod‐Beroud Gwenaelle , Tuffery‐Giraud Sylvie , Elfertit Hassan , Claustres Mireille , Coubes Philippe
Published: January 2010

Long‐term efficacy of internal globus pallidus (GPi) deep‐brain stimulation (DBS) in DYT1 dystonia and disease progression under DBS was studied. Twenty‐six patients of this open‐label study were divided into two groups: (A) with single bilateral GPi lead, (B) with a second bilateral GPi lead implanted owning to subsequent worsening of symptomatology. Dystonia was assessed with the Burke Scale. Appearance of new symptoms and distribution according to body region were recorded. In the whole cohort, significant decreases in motor and disability subscores (P < 0.0001) were observed at 1 year and maintained up to 10 years. Group B showed worsening of the symptoms. At 1 year, there were no significant differences between Groups A (without subsequent worsening) and B; at 5 years, a significant difference was found for motor and disability scores. Within Group B, four patients exhibited additional improvement after the second DBS surgery. In the 26 patients, significant difference (P = 0.001) was found between the number of body regions affected by dystonia preoperatively and over the whole follow‐up. DBS efficacy in DYT1 dystonia can be maintained up to 10 years (two patients). New symptoms appear with long‐term follow‐up and may improve with additional leads in a subgroup of patients. © 2009 Movement Disorder Society
The spectrum of movement disorders in Glut‐1 deficiency
Authors: Pons Roser , Collins Abbie , Rotstein Michael , Engelstad Kristin , De Vivo Darryl C
Published: January 2010

To assess the spectrum of movement disorders, we reviewed video recordings and charts of 57 patients with Glut‐1 deficiency. Eighty‐nine percent of patients with Glut‐1 deficiency syndrome had a disturbance of gait. The most frequent gait abnormalities were ataxic‐spastic and ataxic. Action limb dystonia was observed in 86% of cases and mild chorea in 75%. Cerebellar action tremor was seen in 70% of patients, myoclonus in 16%, and dyspraxia in 21%. Nonepileptic paroxysmal events occurred in 28% of patients, and included episodes of ataxia, weakness, Parkinsonism and nonkinesogenic dyskinesias. The 40 patients (70%) who were on the ketogenic diet had less severe gait disturbances but more dystonia, chorea, tremor, myoclonus, dyspraxia, and paroxysmal events compared with the 17 patients on a conventional diet. Poor dietary compliance and low ketonuria appear to trigger the paroxysmal events in some patients. Gait disturbances and movement disorders are frequent in patients with Glut‐1 deficiency and are signs of chronic and intermittent pyramidal, cerebellar and extrapyramidal circuit dysfunction. These clinical symptoms reflect chronic nutrient deficiency during brain development and may be mitigated by chronic ketosis. © 2009 Movement Disorder Society
Orodispersible sublingual piribedil to abort OFF episodes: A single dose placebo‐controlled, randomized, double‐blind, cross‐over study
Authors: Rascol Olivier , Azulay Jean‐Philippe , Blin Olivier , Bonnet Anne‐Marie , Brefel‐Courbon Christine , Césaro Pierre , Damier Philippe , Debilly Bérengère , Durif Frank , Galitzky Monique , Grouin Jean‐Marie , Pennaforte Sylvie , Villafane Gabriel , Yaici Sadek , Agid Yves
Published: January 2010

S90049, a novel sublingual formulation of the non‐ergoline D2‐D3agonist piribedil, has a pharmacokinetic profile promising to provide rapid relief on motor signs in Parkinson's disease (PD). We assessed the efficacy and safety of S90049 in aborting OFF episodes responding to subcutaneous apomorphine in PD patients with motor fluctuations. This was a single‐dose double‐blind double‐placebo 3 × 3 cross‐over study. Optimal tested doses were determined during a previous open‐label titration phase (S90049 median dose: 60 mg, apomorphine: 5 mg). Primary endpoint was the maximal change versus baseline in UPDRS motor score (ΔUPDRS III) assessed after drug administration following an overnight withdrawal of antiparkinsonian medications. Thirty patients (age: 60 ± 8 years, PD duration: 12 ± 6 years, UPDRS III OFF: 37 ± 15) participated. S90049 wassuperior to placebo on ΔUPDRS III (−13 ± 12 versus −7 ± 9 respectively; estimated difference −5.2, 95% Confidence Interval (CI)[−10.4;0.05],P= 0.05). This was also true for secondary outcomes: number of patients switching from OFF to ON (17 on S90049 vs. 8 on placebo,P= 0.03), time to turn ON (P= 0.013) and duration of the ON phase (P= 0.03). In the 17 patients who switched ON on S90049, ΔUPDRS III was similar on S90049 (−21.2 ± 10.1) and apomorphine (−23.6 ± 14.1) (estimated difference: 4.0 95% CI [−2.9;10.9]). S90049 was well tolerated: no serious or unexpected adverse event occurred. A single dose of up to 60 mg of S90049 given sublingually was superior to placebo in improving UPDRS III and aborting a practical OFF in patients with advanced PD. Testing greater doses might improve response rate. © 2009 Movement Disorder Society
Plasma α‐synuclein in patients with Parkinson's disease with and without treatment
Authors: Duran Raquel , Barrero Francisco J. , Morales Blas , Luna Juan D. , Ramirez Manuel , Vives Francisco
Published: January 2010

Alpha‐synuclein (α‐syn) is an intracellular protein with a high tendency to aggregation. It is the major component of Lewy bodies and may play a key role in the pathogenesis of Parkinson's disease (PD). α‐Syn is also released by neurons and can be detected in biological fluids, such as plasma. The purpose of this study was to determine whether plasma α‐syn concentrations are elevated in newly diagnosed PD patients before treatment (nontreated PD group, ntPD; n = 53) and to compare them with concentrations in PD patients with at least 1 year of specific treatment (tPD; n = 42) and in healthy controls (n = 60). Plasma α‐syn concentrations in the ntPD and tPD groups were similar and significantly higher than in healthy controls. In conclusion, α‐syn was elevated early in the development of PD and specific PD treatment did not change plasma α‐syn levels. © 2010 Movement Disorder Society
Muscular pain in Parkinson's disease and nociceptive processing assessed with CO2 laser‐evoked potentials
Authors: Tinazzi Michele , Recchia Serena , Simonetto Sara , Tamburin Stefano , Defazio Giovanni , Fiaschi Antonio , Moretto Giuseppe , Valeriani Massimiliano
Published: January 2010

Muscular pain is the most frequent kind of nondystonic pain associated with Parkinson's disease (PD). It might be related not only to peripheral factors but also to an abnormal nociceptive input processing in the central nervous system. To test this hypothesis, we recorded CO2 laser‐evoked potentials (LEPs) in response to shoulder stimulation (skin over deltoid muscle) in 11 hemiparkinsonian PD patients complaining of muscular pain in the shoulder (ipsilateral to motor symptoms) and compared the results with those obtained in 12 pain‐free PD patients with hemiparkinson and in 11 normal subjects. N2/P2 LEP, which is thought to originate from the cingulate cortex and insula, was significantly lower in amplitude in both groups of PD patients than in controls, regardless of the clinically affected body side. In both groups of PD patients, no significant correlation was observed between the severity of motor symptoms and N2/P2 amplitude abnormalities. In PD patients with muscular pain, the N2/P2 amplitude obtained following stimulation of the painful shoulder was significantly reduced compared with that obtained in response to nonpainful shoulder stimulation and compared with the values obtained in pain‐free PD patients. No significant correlation was observed between the intensity of muscular pain and N2/P2 amplitude abnormalities in this group of PD patients. These results suggest abnormal nociceptive input processing in PD, which appears to be independent of clinical expression of parkinsonian motor signs. These alterations are more evident in the presence of muscular pain. © 2010 Movement Disorder Society
Artistic profession: A potential risk factor for dopamine dysregulation syndrome in Parkinson's disease?
Authors: Schwingenschuh Petra , Katschnig Petra , Saurugg Ronald , Ott Erwin , Bhatia Kailash P.
Published: January 2010

A small proportion of patients with Parkinson's disease (PD) develop a dopamine dysregulation syndrome (DDS). Management of such patients can be difficult; hence, early identification and careful monitoring of at‐risk individuals are important. Based on four illustrative cases, we wish to draw attention to the risk of developing DDS in PD patients engaged in a creative and artistic profession, who compulsively abuse dopaminergic drugs to maintain or enhance their artistic creativity. Balancing the drug requirement for treating motor symptoms on one hand and improving creativity on the other hand has to be carefully evaluated and early neuropsychiatric intervention may be necessary. Apart from the known risk factors—young age at PD onset, male gender, heavy alcohol consumption, illegal drug use, and history of affective disorder—engagement in a creative or artistic profession may be an additional risk factor for developing DDS. © 2010 Movement Disorder Society
An exploration of the burden experienced by spousal caregivers of individuals with Parkinson's disease
Authors: Roland Kaitlyn P. , Jenkins Mary E. , Johnson Andrew M.
Published: January 2010

Although previous research has attempted to identify the needs of caregivers for individuals with Parkinson's disease (PD), most has focused on the demands associated with the physical needs of the patient, and not on “mental burden.” This study used the repertory grid method to capture the full range of caregivers' subjective experience, quantify their perceptions, and to acquire information that might be useful in directing remediation attempts. Within this sample, caregivers reported far greater burden from “mental stress” (e.g., worrying about individual's safety) than from “physical stress” (e.g., lifting individual into bed). Specifically, caregivers were primarily concerned about spousal safety, as this requires continuous vigilance and constant worry. Caregivers also reported experiencing “little deaths” as the disease progresses, related to a loss of independence for the couple, and the steady diminishment of social networks. Increasing attention on the mental burden experienced by spousal caregivers promises to increase quality of care, and quality of life for individuals with PD, by improving quality of life for the caregiver. © 2010 Movement Disorder Society
B cell depletion therapy for new‐onset opsoclonus‐myoclonus
Authors: Pranzatelli Michael R. , Tate Elizabeth D. , Swan Jennifer A. , Travelstead Anna L. , Colliver Jerry A. , Verhulst Steven J. , Crosley Carl J. , Graf William D. , Joseph Suja A. , Kelfer Howard M. , Raju G. Praveen
Published: January 2010

Twelve immunotherapy‐naïve children with opsoclonus‐myoclonus syndrome and CSF B cell expansion received rituximab, adrenocorticotropic hormone (ACTH), and IVIg. Motor severity lessened 73% by 6 mo and 81% at 1 yr (P < 0.0001). Opsoclonus and action myoclonus disappeared rapidly, whereas gait ataxia and some other motor components improved more slowly. ACTH dose was tapered by 87%. Reduction in total CSF B cells was profound at 6 mo (‐93%). By study end, peripheral B cells returned to 53% of baseline and serum IgM levels to 63%. Overall clinical response trailed peripheral B cell and IgM depletion, but improvement continued after their levels recovered. All but one non‐ambulatory subject became ambulatory without additional chemotherapy; two relapsed and remitted; four had rituximab‐related or possibly related adverse events; and two had low‐titer human anti‐chimeric antibody. Combination of rituximab with conventional agents as initial therapy was effective and safe. A controlled trial with long‐term safety monitoring is indicated. © 2009 Movement Disorder Society
Fibrin glue mitigates the learning curve of microneurosurgical repair
Authors: Whitlock Elizabeth L. , Kasukurthi Rahul , Yan Ying , Tung Thomas H. , Hunter Daniel A. , Mackinnon Susan E.
Published: January 2010

Microneurosurgical technique has a steep learning curve. An alternative to microepineurial suture repair of peripheral nerves that circumvents this learning curve would be ideal. We investigated the effect of surgeon experience on suture versus fibrin glue coaptations in a mouse sciatic nerve graft model. Sixty‐four mice received sciatic nerve grafts with either suture or fibrin glue repair by either a naïve surgeon (medical student) or a surgeon with extensive microsurgical experience. Grafts underwent quantitative histomorphometry at 3 weeks postoperatively. Suture repairs performed by the naïve surgeon demonstrated significantly poorer distal regeneration than all other repairs. Histomorphometric parameters of suture and glue repairs performed by the experienced surgeon were not significantly different from the glue coaptation by the naïve surgeon. Fibrin glue may be considered as an alternative to microepineurial suture repair, particularly in the setting of relative surgeon inexperience with microsurgical technique. © 2010 Wiley‐Liss, Inc. Microsurgery 2010.
A compact U‐shaped defected ground structure microstrip low‐pass filter with wideband rejection
Authors: Deng Kuan , Feng Wenjie , Che Wenquan
Published: January 2010

A compact triple U‐shaped slots etched on the microstrip ground are used to implement a novel low‐pass filter.A rectangular open stub and a radius stub are used to produce transmission zeros and thus result in wide stopband. Good low‐pass performance and wide stopband characteristics can be achieved by this new structure. One prototype is fabricated to demonstrate the validity of the design strategies. The simulated and measured results indicate that the insertion loss is less than 0.25 dB and the return loss is less than −16.7 dB in the whole passband. In addition, significant improvement on rejection band can be observed; the stopband bandwidth better than −25 dB is about 105% (from 2.6 to 8.4 GHz). © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 497–499, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24960
Photonic generation of microwave signals by exploiting fiber birefringence effect in single‐longitudinal‐mode distributed Bragg reflector fiber lazer
Authors: Zhang Hao , Liu Bo , Sun Jing , Luo Jianhua , Wang Shuangxia , Jia Chenglai , Ma Xiurong
Published: January 2010

A novel all‐optical microwave generation technique based on fiber birefringence effect in single‐longitudinal‐mode (SLM) distributed Bragg reflector (DBR) fiber lazer is presented. Owing to the birefringence‐induced mode splitting, the proposed lazer could provide a microwave signal at ∼1.72 GHz with a 3 dB bandwidth of ∼30 kHz. Moreover, another microwave signal at 10.96 GHz could also be generated as transverse pressure was applied onto the proposed lazer. Similar phenomenon was observed when another DBR lazer constructed with Er/Yb co‐doped fiber was used, and a microwave signal at 11.47 GHz with ∼33 kHz linewidth have also been achieved. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 535–540, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24961
Multilevel fast multipole algorithm enhanced by GPU parallel technique for electromagnetic scattering problems
Authors: Xu Kan , Ding Da Zhi , Fan Zheng Hong , Chen Ru Shan
Published: January 2010

Along with the development of graphics processing Units (GPUS) in floating point operations and programmability, GPU has increasingly become an attractive alternative to the central processing unit (CPU) for some of compute‐intensive and parallel tasks.In this article, the multilevel fast multipole algorithm (MLFMA) combined with graphics hardware acceleration technique is applied to analyze electromagnetic scattering from complex target. Although it is possible to perform scattering simulation of electrically large targets on a personal computer (PC) through the MLFMA, a large CPU time is required for the execution of aggregation, translation, and deaggregation operations. Thus GPU computing technique is used for the parallel processing of MLFMA and a significant speedup of matrix vector product (MVP) can be observed. Following the programming model of compute unified device architecture (CUDA), several kernel functions characterized by the single instruction multiple data (SIMD) mode are abstracted from components of the MLFMA and executed by multiple processors of the GPU. Numerical results demonstrate the efficiency of GPU accelerating technique for the MLFMA. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 502–507, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24963
Miniaturized band‐stop filter based on multilayer‐technique and new coupled octagonal defected ground structure with interdigital capacitor
Authors: Boutejdar A. , Abdel‐Rahman A. , Batmanov A. , Burte P. , Omar A.
Published: January 2010

In this article, we proposed a new compact defected ground structure (DGS) band‐stop filter with broad passband and low insertion loss in the stop‐band. The philosophy of the structure behind this new microstrip band‐stop filter is simple as it is composed of a pair of octagonal DGS‐slots and an open‐stub as compensated microstrip capacitance. The filter will be realized through direct electromagnetic coupling and slow wave effect methods. With this configuration, the BSF with higher compactness, broad passband and sharp transition characteristics was realized. The design formulas are derived by using an equivalent‐circuit model of a parallel L‐C resonator. Finally, an interdigital‐capacitor has been designed and included in the DGS‐ring‐element. Better compactness of the structure and symmetry of the frequency response have been achieved as well as two reflection zeros closed to the stopband have been obtained. Thus, a selectivity of the proposed filter has been improved. To validate the feasibility of the proposed design method, both band‐stop filters are designed, fabricated, and measured. The experimental results agree well with the simulation results. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 510–514, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24967
A compact wideband bandpass filter using modified NB‐SRRs with wide upper bandstop
Authors: Chaimool Sarawuth , Akkaraekthalin Prayoot
Published: January 2010

A new type of compact wideband bandpass filter using modified non‐bianisotropic split‐ring resonators is proposed to have wideband performance and suppress spurious responses. With the proposed resonators, size reduction of ∼15% and 20% when comparing single outer and inner constituent rings has been obtained. Embedded‐slot‐loaded resonators are placed at both input and output feed lines for extra stopband rejection modes to suppress spurious frequencies with attenuation losses over than 15 dB for a frequency range up to 3.1 f0 without affecting the operation band. In addition, due to the zero‐degree feed structure, the appearance of two transmission zeros, thereby suppressing the second harmonic response has been obtained. This filter has not been only compact size but also a wider upper stopband caused by slot‐loaded resonator bandstop characteristics. Good agreement is obtained between simulations and measurements. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 551–553, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24968
Fully adaptable band‐stop filter using varactor diodes
Authors: Musoll‐Anguiano Carles , Llamas‐Garro Ignacio , Brito‐Brito Zabdiel , Pradell Lluis , Corona‐Chavez Alonso
Published: January 2010

In this article a reconfigurable band‐stop filter able to reconfigure center frequency, bandwidth, and selectivity for fine tuning applications is demonstrated, device topology discussion and implementation details are given, and followed by discussion on simulations and measurements.The reconfigurable filter topology has four poles and a quasi‐elliptic band‐stop filter response. The device is tuned by varactor diodes placed at different locations on the filter; varactors are voltage controlled in pairs due to filter symmetry for center frequency and bandwidth control. An additional varactor is placed on a crossing line to move a pair of transmission zeros, closer or farther to the filter center frequency, which tunes filter selectivity. Simulations show a tuneable center frequency range from 1.42 to 1.48 GHz, a tuneable fractional bandwidth range from 9.46 to 12.96%, and a tuneable selectivity range from 0.53 to 0.65 dB/MHz. Measurements show a tuneable center frequency range from 1.37 to 1.43 GHz, a tuneable fractional bandwidth range from 11.31 to 15.93%, and a selectivity tuning range from 0.37 to 0.40 dB/MHz. Simulations and measurements are in good agreement. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 554–558, 2010; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/mop.24969
A novel tri‐band filter using stub‐loaded open loop ring resonators
Authors: Lai Xin , Wu Bian , Su Tao , Liang Chang‐Hong
Published: January 2010

In this article, a novel type of compact tri‐band filter using stub‐loaded open‐loop ring resonators (OLRRs) is presented.With the open stub loaded, the resonant frequency of the OLRR can be tuned by the tapped location and length of the loaded stub, which makes the OLRR more compact. Making use of the microstrip open‐ended feed line, proper external couplings are provided to each passband by magnetic coupling. A tri‐band filter centered at 2.0 GHz, 3.2 GHz, and 4.3 GHz is designed, fabricated and measured. Predicted results are verified by the experiments. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 523–526, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24971
Iterative design of moth‐eye antireflective surfaces at millimeter wave frequencies
Authors: Mirotznik Mark S. , Good Brandon , Ransom Paul , Wikner David , Mait Joseph N.
Published: January 2010

A method for synthesizing broadband antireflective (AR) surfaces at millimeter wave frequencies is demonstrated. AR surfaces were formed by machining a multilayer subwavelength structures into nonabsorptive dielectrics. This created low‐reflected energies (<−25 dB) over large bandwidths and incidence angles. Experimental results are provided demonstrating the validity of the method. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 561–568, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24973
Efficiency enhancement of the Doherty amplifier for 3.5 GHz WiMAX application using class‐F circuitry
Authors: Park Jun‐Chul , Kim Dongsu , Yoo Chan‐Sei , Lee Woo Sung , Yook Jong‐Gwan , Hahn Cheol Koo
Published: January 2010

This article presents a high‐power and high‐efficiency saturated Doherty amplifier using a GaN high electron mobility transistor for 3.5 GHz Worldwide Interoperability for Microwave Access application.The saturated Doherty amplifier is a Doherty amplifier based on class‐F amplifiers, resulting in higher efficiency than a conventional Doherty amplifier. The distributed‐type harmonic control circuit is located between a power transistor and an output matching circuit. From the measured results for a continuous wave of 3.5 GHz, the saturated Doherty amplifier attains a high P3dB of 45 dBm and a power gain of about 8.8 dB. Also, the proposed Doherty amplifier provides a high power‐added‐efficiency (PAE) of 37.7% and a drain efficiency of 42.7% at 6‐dB back‐off output power region from P3dB, which are 8.7% and 5.7% higher than those of the conventional Doherty amplifier. Compared to the single class‐AB amplifier, we obtain 17.7% and 19.7% improvement of PAE and drain efficiency, respectively. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 570–573, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24977
Pattern reconfiguration of microstrip antenna using flip‐chip mounted packaged MEMS
Authors: Raj R. , Poussot B. , Laheurte J.‐M. , Vendier O.
Published: January 2010

This work describes the design of a radiation pattern reconfigurable microstrip antenna electrically controlled by packaged Radio frequency micro‐electro‐mechanical system (RF MEMS). The antenna operates at 12.24 GHz with good return loss characteristics and a ∼7.5 dBi gain at ±30° scan angles from broadside direction in the H‐plane. The integration of packaged RF MEMS and associated bias networks is also explained. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 574–577, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24978
RCS control using cascaded circularly polarized frequency selective surfaces and an AMC structure as a switchable twist polarizer
Authors: Euler M. , Fusco V. F.
Published: January 2010

This article presents a cascaded arrangement comprising a double‐layer frequency selective surface circularly polarizing (CPFSS) and a second screen that can be switched between artificial magnetic conductor (AMC), or perfect electric conducting, (PEC), states.The CPFSS consists of two stacked aluminum sheets patterned with periodic split ring structures. While the AMC is a PCB sheet patterned with metallic squares interconnected by links. By either open or short circuiting these links it is shown that the cascade of screens can be made to twist, or not to twist, an incident 45° linearly polarized signal through 90° upon reflection from the assembly. The system was designed and optimized using CST software and predictions were validated experimentally at X‐band. The results obtained show good agreement between experimental and measured monostatic reflection loss results. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 577–580, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24979
RF MEMS tunable filter using micro fixed–fixed beam
Authors: Islam Md. Fokhrul , Mohd Ali Mohd Alauddin , Majlis Burhanuddin Yeop
Published: January 2010

In this article, a tunable bandpass filter using micro fixed‐fixed beam structure is designed, simulated, and fabricated. The filter is designed by micromachined capacitive bridges, with an original passive topology. The fabricated filter occupies a chip area of 12 × 3 mm2and achieved an insertion loss of less than 2 dB and return loss of less than −15 dB throughout the operation band, thereby tuning the filter centre frequency by 11% between 8.76 and 9.8 GHz. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 592–597, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24981
CMOS passive wake‐up circuit for sensor network applications
Authors: Kim Hyungchul , Cho Hanjin , Xi Yao , Kim Minsu , Kwon Sungwook , Lim Joonhyung , Yang Youngoo
Published: January 2010

A passive wake‐up circuit with high‐voltage sensitivity using standard CMOS technology has been designed and implemented.Voltage multipliers and inverter chain optimized for high‐voltage sensitivity have been proposed. A radio identification scheme to make peer‐to‐peer communication has also been proposed. The wake‐up circuit converts small‐RF input signals into a DC signal to trigger the interrupt. A duty cycle scheduling is adopted for an advanced power control. Using an RF input signal, whose center frequency is 870 MHz and input power is −29.3 dBm, we achieved an output voltage of 0.7 V, enough to trigger on the output. The fully integrated CMOS IC is fabricated using a 0.18‐μm standard CMOS process. The chip area is as small as 230 × 190 μm2. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 597–600, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24982
Characterization and modeling of nonlinear mixer behavior for 77‐GHz radar systems
Authors: Treml Markus , Wagner Christoph , Stelzer Andreas , Jäger Herbert
Published: January 2010

A behavioral model describing the behavior of active mixers in the linear and the saturation mode of operation is presented. The model allows the simulation of effects caused by high‐level blocking signals. A 77‐GHz multi‐tone signal is used for characterizing the nonlinear behavior of the mixer. Because of the calculation of the nonlinearity in the complex baseband, the mixer behavior can be simulated very efficiently as necessary for the usability in complex radar system simulations. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 639–642, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24983
Linearization of a 3.7 GHz multi‐carrier GaN HEMT Doherty power amplifier using digital predistortion method
Authors: Jeong Jonghyuk , Van Juho , Cho Jaeyong , Kim Min‐Su , Cho Hanjin , Lim Kyung‐Hoon , Kwon Sung‐Wook , Choi Kyonggon , Kim Hyung‐Chul , Yoo Sungcheol , Park Cheon‐Seok , Yang Youngoo
Published: January 2010

In this article, a 3.7 GHz band Doherty amplifier based on GaN HEMTs, which is linearized using a digital predistortion method, is implemented for 4th generation wireless communication systems. The forward and reverse models of the Doherty amplifier for the predistortion consist of simple polynomials whose coefficients are extracted using a conventional least mean square error algorithm. Using a two carrier signal based on IEEE802.16e, whose PAR is 9.44 dB, an ACLR improvement of 10.74 dB is achieved to give an ACLR level of 41.74 dBc at an offset of 4.79 MHz. The overall efficiency of the Doherty power amplifier is 13.74%, which represents a 2.44% improvement compared with that of a balanced class‐AB power amplifier at an average output power of 36 dBm. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 634–638, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24984
An on‐chip two‐state single‐turn spiral inductor for reconfigurable RF circuit designs
Authors: Woods Wayne , Ding Hanyi , Wang Guoan , Mina Essam
Published: January 2010

A two‐state single turn spiral inductor design is simulated in a 130 nm technology and another design is simulated and measured in a 45 nm technology. Measurements show an 80% inductance increase at 20 GHz in the 45 nm technology and a simulated 76% increase at 24 GHz in the 130 nm technology. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 673–677, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24985
Investigation of several terahertz electromagnetic band gap structures
Authors: Wu Ziran , Young Abram , Gehm Michael , Xin Hao
Published: January 2010

Several THz electromagnetic band gap (EBG) structures are investigated and demonstrated.Various design, fabrication, and characterization methods and techniques are utilized and compared. These THz EBG structures may enable future high performance EBG based THz components. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 678–686, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24986
Influence of strength and asymmetry of the coupling between a cavity and a transmission line on measurement of complex permittivity
Authors: Ikeda Masaaki , Nishida Kazuaki , Nagata Yasuyuki , Shimasaki Hitoshi , Akiyama Masahiro
Published: January 2010

Influence of the strength and the asymmetry of input‐output ports on the measurement of complex permittivity by the resonant cavity perturbation method was investigated experimentally.We adopted the |S21| as the criterion of the strength, and the difference between S11 and S22 as the criterion of the asymmetry. When the coupling is symmetric, the real part of permittivity can be evaluated in strong coupling state up to −3 dB of coupling. The imaginary part of permittivity can be evaluated up to −14 dB of coupling. Imaginary part of the relative permittivity ε″r was calculated using the conventional equation, which is based on the complete symmetry of the coupling of input‐output ports. For the measurement of high‐Q materials, calculated ε″r is strongly affected by the asymmetry in the strongly coupled region. For the measurement of lossy materials, the inevitable asymmetry and the strong coupling allow enough exact evaluation of ε″r. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 706–709, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24988
CMOS multi‐band wireless direct‐conversion receiver for SDR
Authors: Lee Sangho , Choi Sanghyun , Lee Jaeseok , Park Jihyun , Kim Hyeongdong
Published: January 2010

In this article, a CMOS multistandard wireless direct‐conversion receiver is designed. The receiver is composed of three components: low noise amplifier, voltage‐controlled oscillator, and mixer. In details, the designed receiver adopts direct‐conversion architecture and accommodates three standards: WCDMA, Wibro (or mobile WIMAX), and CDMA 2000 1×: 1.84–2.4 GHz. The designed mixer is a passive sub‐harmonic doubly balanced structure, the VCO is a back‐gate coupling quadrature VCO, and the LNA is a differential structure. Each component is designed with relevance to direct‐conversion architecture. The designed mixer has no flicker noise theoretically because the mixing transistors operate in the triode region. Also, DC offset problem is avoided, because local oscillator frequency is half of RF frequency and the port isolation is improved by the innate characteristic of a balanced structure. The VCO generates a quadrature signal and the oscillation frequency is half of RF frequency to drive designed sub‐harmonic mixer. No coupling transistors are needed due to the use of back‐gate coupling to reduce flicker noise. Back‐gate coupling means that the body of a transistor is used as another gate. The LNA, which adopts a well‐known cascade structure, is designed as a differential structure to suppress common mode noise and to drive a doubly balanced mixer. All designed components are fabricated by the TSMC 0.18‐μm RF CMOS process. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 718–721, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24989
Narrow band‐stop filters design with I‐shape resonators
Authors: Yeung S. H. , Man K. F.
Published: January 2010

The design issues of narrow band‐stop filters using I‐shape resonators are discussed. The resonators are cascaded to improve the band‐stop attenuation and to achieve multiple stop‐bands. The performance of the resonator and its transmission line model will be presented. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 757–763, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24992
Miniaturized microstrip dual‐band power divider on localized substrate integrated artificial dielectric
Authors: Tang Wanchun , Wang Xiaoke , Wen Zhonghui
Published: January 2010

Localized substrate integrated artificial dielectric (L‐SIAD) is a structure with only metallic posts right under microstrip line, leading to planar microstrip circuit miniaturization.When compared with original substrate integrated artificial dielectric (SIAD), the fabrication for L‐SIAD will be more economical and easier, whereas the characteristics of L‐SIAD is almost the same as that of original SIAD. A microstrip dual‐band power divider on L‐SIAD exhibits an area reduction of about 40% compared with that on regular substrate. By proper design of L‐SIAD, more area reduction can be achieved. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 644–648, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24997
Design of three new types of active quasi‐circulator modules
Authors: Bahri Reza , Abdipour Abdolali , Moradi Gholamreza
Published: January 2010

Analysis and design of three novel active quasi‐circulator modules are presented, which use the nonreciprocal properties of microwave unilateral power divider/combiner and amplifiers.These modules have many variations and can be used for very wide frequency range depending on the type of the unilateral amplifier used. Also, they can be used in MMICs as active circulators and also in other high‐frequency applications. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 689–694, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24998
Interference analysis between ZigBee transceivers at 2.4 GHz frequency bands in a multiple integrated laser engagement system
Authors: Yoo Hojoon , Kwak Hyun‐Sang , Kim Jong‐Heon , Lee Chan‐Joo
Published: January 2010

Interference scenarios between ZigBee transceivers in a multiple integrated laser engagement system have been presented.The permissible output power of interfering transmitters measured in the case of a direct link and a direct link with repeaters. The later was reduced by 10 dB relative to that for the direct link. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 662–665, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24999
A 2.4 GHz CMOS diversity receiver having a soft‐start regulator for wake‐up
Authors: Kwon Yong‐iL , Cho Han‐Jin , Lee Hai‐Young
Published: January 2010

An improved diversity receiver having a new regulator for stable power supply in a 0.18 μm CMOS technology is presented. The regulator with soft‐start is implemented to eliminate the battery damages at initial power‐up. To reduce the external components, two switches for antenna diversity are integrated in front of LNA on the chip. A stacked inductor technique is adopted to reduce the chip area. The simulation and measurement results show that the soft‐start time of the regulator can be controlled by a variable resistor from 200 μS to 6.2 mS. The front‐end (LNA and mixer) can achieve a voltage gain of 33.5 dB, a noise figure (NF) of 3.8 dB, and 23 dB of the isolation between antennas when consuming 3.9 mW with a 1.8 V power supply. The NF includes the loss of a BALUN, BPF, and switches. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 611–615, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25000
Class‐B amplifier using a periodic loop combiner
Authors: Eccleston Kimberley W.
Published: January 2010

An N‐way combiner that provides low‐valued load impedances for FETs is presented. The combiner comprises periodic loops of transmission lines with moderate valued characteristic impedance. Its area is directly proportional to the number of FETs to be combined. For application in class‐B amplifiers, even‐harmonic suppression is considered. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 725–728, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25001
Improved tapered slot‐line antennas by using grating loading
Authors: Zhang Peng , Zhang Wen‐Xun
Published: January 2010

A new scheme for improving linearly tapered slot‐line antenna (LTSA) has been proposed in this article. By setting five metallic strips as a grating into the slot‐area of LTSA, a 2 dB increment of gain over the frequency range of (6.0–9.5) GHz and the bandwidth of (5.3–9.6) GHz for VSWR <2.0:1 are obtained. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 728–731, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25002