bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification and characterization of pannexin expression in the mammalian cochlea
Authors: Wang Xiao‐Hui , Streeter Michele , Liu Ying‐Peng , Zhao Hong‐Bo
Published: November 2008

The gap junction in vertebrates is encoded by the connexin gene family. Recently, a new gene family termed pannexin (Panx) has been identified in vertebrates and found to encode gap junctional proteins as well. To date, three pannexin isoforms (Panx1, 2, and 3) have been cloned from mouse and human genomes. In this study, expression of pannexins in the mouse and rat cochlea was investigated. Polymerase chain reaction and Western blot analysis showed that all three pannexin isoforms were expressed in the cochlea. Immunofluorescent staining showed that Panx1 expression was extensive. In the organ of Corti, Panx1 labeling was found in supporting cells, including pillar cells, Hensen cells, Claudius cells, and Boettcher cells. Both surface plaque‐like punctate labeling and diffuse‐cytoplasmic labeling were visible. However, the labeling was weak and rare in Deiters cells. No labeling was found in the hair cells. Intense labeling for Panx1 was also observed in the interdental cells in the spiral limbus, the inner and outer sulcus cells, and the type II fibrocytes in the spiral prominence and central region in the cochlear lateral wall. In addition, Panx1 labeling was detectable in Reissner's membrane and strial blood vessel cells. Panx2 labeling was restricted to the basal cells in the stria vascularis and was also detectable in the spiral ganglion neurons. However, no overlapping labeling for Panx1 and Panx2 was observed. Finally, Panx3 labeling was exclusively observed in the cochlear bone. Thus, Panx1, 2, and 3 are abundantly expressed in the mammalian cochlea and demonstrate distinct cellular distributions. Like connexins, they may play an important role in hearing. J. Comp. Neurol. 512:336–346, 2009. © 2008 Wiley‐Liss, Inc.
Expression of the voltage‐gated potassium channel KCNQ1 in mammalian taste bud cells and the effect of its null‐mutation on taste preferences
Authors: Wang Hong , Iguchi Naoko , Rong Qi , Zhou Minliang , Ogunkorode Martina , Inoue Masashi , Pribitkin Edmund A. , Bachmanov Alexander A. , Margolskee Robert F. , Pfeifer Karl , Huang Liquan
Published: November 2008

Vertebrate taste buds undergo continual cell turnover. To understand how the gustatory progenitor cells in the stratified lingual epithelium migrate and differentiate into different types of mature taste cells, we sought to identify genes that were selectively expressed in taste cells at different maturation stages. Here we report the expression of the voltage‐gated potassium channel KCNQ1 in mammalian taste buds of mouse, rat, and human. Immunohistochemistry and nuclear staining showed that nearly all rodent and human taste cells express this channel. Double immunostaining with antibodies against type II and III taste cell markers validated the presence of KCNQ1 in these two types of cells. Co‐localization studies with cytokeratin 14 indicated that KCNQ1 is also expressed in type IV basal precursor cells. Null mutation of the kcnq1 gene in mouse, however, did not alter the gross structure of taste buds or the expression of taste signaling molecules. Behavioral assays showed that the mutant mice display reduced preference to some umami substances, but not to any other taste compounds tested. Gustatory nerve recordings, however, were unable to detect any significant change in the integrated nerve responses of the mutant mice to umami stimuli. These results suggest that although it is expressed in nearly all taste bud cells, the function of KCNQ1 is not required for gross taste bud development or peripheral taste transduction pathways, and the reduced preference of kcnq1‐null mice in the behavioral assays may be attributable to the deficiency in the central nervous system or other organs. J. Comp. Neurol. 512:384–398, 2009. © 2008 Wiley‐Liss, Inc.
Endothelial progenitor cells: Implications for cardiovascular disease
Authors: Möbius‐Winkler Sven , Höllriegel Robert , Schuler Gerhard , Adams Volker
Published: November 2008

Endothelial progenitor cells (EPCs) reside in the bone marrow and are mobilized into the circulation by specific stimuli such as certain drugs, ischemia, and exercise training. Once in the circulation EPCs are thought to participate in the maintenance of the endothelial cell layer. Recently it was clearly demonstrated that the amount and function of EPCs is significantly impaired in different cardiovascular diseases. Furthermore, the level of circulating EPCs predicts the occurrence of cardiovascular events and death from cardiovascular causes and may help to identify patients at increased cardiovascular risk. After demonstrating the beneficial effect of applied EPCs in several animal experiments, these cells were also used to treat humans with different cardiovascular diseases. This review will focus on the characterization and liberation of EPCs from the bone marrow, as well as on the most important clinical cardiovascular diseases for which EPCs were used therapeutically. © 2008 International Society for Advancement of Cytometry
FTY720 suppresses the development of colitis in lymphoid‐null mice by modulating the trafficking of colitogenic CD4+ T cells in bone marrow
Authors: Fujii Toshimitsu , Tomita Takayuki , Kanai Takanori , Nemoto Yasuhiro , Totsuka Teruji , Sakamoto Naoya , Nakamura Tetsuya , Tsuchiya Kiichiro , Okamoto Ryuichi , Watanabe Mamoru
Published: November 2008

2‐Amino‐2‐(2‐[4‐octylphenyl]ethyl)‐1,3‐propanediol hydrochloride (FTY720) suppresses T‐cell egress from LN, thereby preventing pathogenic T cells from migrating toward disease sites. However, little is known about whether FTY720 could control the trafficking of T cells without the presence of lymphoid tissues. Here we demonstrate that FTY720 treatment suppresses the recirculation of CD4+ T cells in splenectomized (SPX) lymphotoxin‐α−/− (LT‐α−/−) mice that lack LN and spleen, as shown by peripheral blood (PB) lymphopenia in FTY720‐treated SPX LT‐α−/− mice. In a short‐term transfer experiment, the cell number of transferred Ly5.1+CD4+ T cells recovered from host FTY720‐treated SPX LT‐α−/− mice (Ly5.2+) was markedly decreased in PB, but conversely increased in BM. Notably, FTY720 treatment prevented the development of colitis that is otherwise induced in untreated SPX LT‐α−/−×RAG‐2−/− mice upon transfer of colitic lamina propria CD4+ T cells. In such mice, the number of CD4+ T cells in PB or lamina propria of FTY720‐treated SPX LT‐α−/−×RAG‐2−/− recipients was significantly reduced, but that in the BM was significantly increased as compared with untreated control mice. Altogether, the present results indicate that FTY720 treatment may offer an additional role to direct trafficking of CD4+ T cells in BM, resulting in the prevention of colitis.
Screening liver transplant patients for tolerance
Authors: Bishop Alex G. , Williams Rohan B. H.
Published: November 2008

Martínez-Llordella M, Lozano JJ, Puig-Pey I, Orlando G, Tisone G, Lerut J, et al. Using transcriptional profiling to develop a diagnostic test of operational tolerance in liver transplant recipients. J Clin Invest 2008;118:2845–2857. (Reprinted with permission.)

A fraction of liver transplant recipients are able to discontinue all immunosuppressive therapies without rejecting their grafts and are said to be operationally tolerant to the transplant. However, accurate identification of these recipients remains a challenge. To design a clinically applicable molecular test of operational tolerance in liver transplantation, we studied transcriptional patterns in the peripheral blood of 80 liver transplant recipients and 16 nontransplanted healthy individuals by employing oligonucleotide microarrays and quantitative real-time PCR. This resulted in the discovery and validation of several gene signatures comprising a modest number of genes capable of identifying tolerant and nontolerant recipients with high accuracy. Multiple peripheral blood lymphocyte subsets contributed to the tolerance-associated transcriptional patterns, although NK and γδTCR+ T cells exerted the predominant influence. These data suggest that transcriptional profiling of peripheral blood can be employed to identify liver transplant recipients who can discontinue immunosuppressive therapy and that innate immune cells are likely to play a major role in the maintenance of operational tolerance in liver transplantation.
Unsaturated fatty acids inhibit the expression of tumor suppressor phosphatase and tensin homolog (PTEN) via microRNA-21 up-regulation in hepatocytes # †
Authors: Vinciguerra Manlio , Sgroi Antonino , Veyrat-Durebex Christelle , Rubbia-Brandt Laura , Buhler Leo H. , Foti Michelangelo
Published: November 2008

Phosphatase and tensin homolog (PTEN) is a regulator of phosphoinositide 3-kinase signaling and an important tumor suppressor mutated/deleted in human cancers. PTEN deletion in the liver leads to insulin resistance, steatosis, inflammation, and cancer. We recently demonstrated that unsaturated fatty acids trigger steatosis by down-regulating PTEN expression in hepatocytes via activation of a mammalian target of rapamycin (mTOR)/nuclear factor kappa B (NF-κB) complex, but the molecular mechanisms implicated in this process are still unknown. Here, we investigated potential genetic and epigenetic mechanisms activated by fatty acids leading to PTEN down-regulation. Our results indicate that unsaturated fatty acids down-regulate PTEN messenger RNA expression in hepatocytes through mechanisms unrelated to methylation of the PTEN promoter, histone deacetylase activities, or repression of the PTEN promoter activity. In contrast, unsaturated fatty acids up-regulate the expression of microRNA-21, which binds to PTEN messenger RNA 3′-untranslated region and induces its degradation. The promoter activity of microRNA-21 was increased by mTOR/NF-κB activation. Consistent with these data, microRNA-21 expression was increased in the livers of rats fed high-fat diets and in human liver biopsies of obese patients having diminished PTEN expression and steatosis. Conclusion: Unsaturated fatty acids inhibit PTEN expression in hepatocytes by up-regulating microRNA-21 synthesis via an mTOR/NF-κB–dependent mechanism. Aberrant up-regulation of microRNA-21 expression by excessive circulating levels of fatty acids exemplify a novel regulatory mechanism by which fatty acids affect PTEN expression and trigger liver disorders. (Hepatology 2009.)
Why we are wasting time in the operating theatre?
Authors: Saha Prithwiraj , Pinjani Anita , Al‐Shabibi Nawar , Madari Sheethal , Ruston John , Magos Adam
Published: November 2008

Objectives To determine reasons for delay during elective operating lists and suggest solutions.

Design Prospective observational study.

Setting A large under‐graduate teaching hospital.

Participants Fifty‐five consecutive women undergoing elective gynaecological surgery under general anaesthesia.

Interventions Every time point of individual patient's passage through the operating theatre (patients sent for, arrival in the anaesthetic room, general anaesthetic commenced, transfer to the operating theatre, surgery started, surgery completed, anaesthetic reversed, patient taken to recovery area) was documented.

Main outcome measures Time intervals between the various time points with particular reference to wait by the anaesthetist and surgeon between cases.

Results We monitored 55 operations carried out during 22 operating lists. Apart from the surgery itself (median 81 min per procedure), the longest interval was the time taken to get patients into the anaesthetic room from the ward (median 20 min). Although patients waited a median of 10 min before the start of anaesthesia, if the first procedure on the list was excluded, the anaesthetist was waiting for the patient to arrive in the anaesthetic room in 13/30 (43%) cases, wasting a median of 7 min per case. The surgeon had to wait a median of 22.5 min between operations.

Conclusions Considerable operating theatre time is wasted while patients are transferred to and from the operating theatre resulting in both anaesthetists and surgeons having to wait between patients in a high proportion of cases, averaging 1 h during a 4 h operating list. Surgery could be made more time efficient by ensuring that patients arrive in the operating theatre complex early enough (to reduce time wasted for anaesthetists and surgeons), and by having two anaesthetists available at the end of surgery, one to reverse the anaesthetic while the other starts the next induction (to reduce time waste for the surgeon), coupled to adequate recovery area capacity. Copyright © 2008 John Wiley & Sons, Ltd.
Effects of low dose quercetin: Cancer cell‐specific inhibition of cell cycle progression
Authors: Jeong Jae‐Hoon , An Jee Young , Kwon Yong Tae , Rhee Juong G. , Lee Yong J.
Published: November 2008

Quercetin is a flavonoid present in many vegetables, fruits, and beverages. Due to its anti‐oxidant, anti‐tumor, and anti‐inflammatory activity, quercetin has been studied extensively as a chemoprevention agent in several cancer models. Since most of these studies used higher doses of quercetin than clinically achievable, we focused on the effectiveness of physiologically relevant doses of quercetin. A low dose of quercetin exerted cancer cell‐specific inhibition of proliferation and this inhibition resulted from cell cycle arrest at the G1phase. Quercetin induced p21 CDK inhibitor with a concomitant decrease of phosphorylation of pRb, which inhibits the G1/S cell cycle progression by trapping E2F1. A low dose of quercetin induced mild DNA damage and Chk2 activation, which is the main regulator of p21 expression by quercetin. In addition, quercetin down‐regulated the cyclin B1 and CDK1, essential components of G2/M cell cycle progression. Inhibition of the recruitment of key transcription factor NF‐Y to cyclin B1 gene promoter by quercetin led to transcriptional inhibition. This study proved that the chemo‐preventive efficacy of a physiologically relevant dose of quercetin can be achievable through the inhibition of cell cycle progression. J. Cell. Biochem. 106: 73–82, 2009. © 2008 Wiley‐Liss, Inc.
Sonocatalytic damage of bovine serum albumin (BSA) under ultrasonic irradiation by mixed TiO2/SiO2 powder
Authors: Wang Jun , Ding Na , Zhang Zhaohong , Wang Shixian , Guo Ying , Liu Bin , Zhang Yuanyuan , Zhang Xiangdong
Published: November 2008

BACKGROUND: In order to effectively damage some biomolecules under ultrasonic irradiation, a mixed TiO2/SiO2 powder with high catalytic activity and selectivity was used as a sonocatalyst.

RESULTS: The mixed TiO2/SiO2 powder heat treated at 450 °C for 30 min was adopted as a sonocatalyst and the damage to BSA molecules under ultrasonic irradiation was assessed. In addition, the effects of such variables as molar ratio of TiO2 and SiO2, treatment temperature and time, ultrasonic irradiation time, catalyst amount, solution acidity, ionic nature and strength, ultrasonic irradiation power and D2O concentration on the damage to BSA molecules were studied by means of UV‐visible and fluorescence spectra. The results showed that the degree of damage was aggravated by an increase in ultrasonic irradiation time, catalyst amount, solution acidity, ultrasonic irradiation power and D2O concentration, but was reduced by an increase in ionic strength.

CONCLUSION: The results indicated that the mixed TiO2/SiO2 powder displayed higher activity and selectivity compared with nano‐sized TiO2 and SiO2 powders during the sonocatalytic damage of BSA. The extent of the damage decreased in the order TiO2/SiO2 > nano‐sized TiO2 > nano‐sized SiO2. These results are of great significance for applying sonocatalytic methods to treat tumours. Copyright © 2008 Society of Chemical Industry
Study of saline wastewater influence on activated sludge flocs through automated image analysis
Authors: Mesquita Daniela P , Amaral Antonio L , Ferreira Eugenio C , Coelho Maria AZ
Published: November 2008

BACKGROUND: In activated sludge systems, sludge settling ability is considered a critical step in effluent quality and determinant of solid–liquid separation processes. However, few studies have reported the influence of saline wastewater on activated sludge. This work aims the evaluation of settling ability properties of microbial aggregates in a sequencing batch reactor treating saline wastewaters of up to 60 g L−1 NaCl, by image analysis procedures.

RESULTS: It was found that the sludge volume index (SVI) decreased with salt content up to 20 g L−1, remaining somewhat stable above this value. Furthermore, it was found that between the first salt concentration (5 g L−1) and 20 g L−1 aggregates suffered a strong deflocculation phenomenon, leading to a heavy loss of aggregated biomass. Regarding SVI prediction ability, a good correlation coefficient of 0.991 between observed and predicted SVI values was attained.

CONCLUSION: From this work the deflocculation of aggregated biomass with salt addition due to pinpoint floc formation, dispersed bacteria growth and protozoa absence could be established. With respect to SVI estimation, and despite the good correlation obtained, caution is advisable given the low number of SVI data points. Copyright © 2008 Society of Chemical Industry
Finite element power diode model optimized through experiment‐based parameter extraction
Authors: Chibante R. , Araújo A. , Carvalho A.
Published: November 2008

This paper presents a finite element physics‐based power diode model with parameters established through an extraction procedure validated experimentally. The model core is a numerical module that solves the ambipolar diffusion equation through a variational formulation followed by an approximate solution with the finite element method. Other zones of the device are modeled with classical methods in an analytical module. This hybrid approach enables accurate modeling and simulation of power bipolar semiconductor devices, using standard SPICE circuit simulators, with low execution times. As physics‐based models need a significant number of parameters, an automatic parameter extraction method has been developed. The procedure, based on an optimization algorithm (simulated annealing), enables an efficient extraction of parameters using some simple device waveform measurements. Implementation details of power diode model, in IsSpice simulator, are presented. Experimental validation is performed. Results prove the usefulness of the proposed methodology for efficient design of power circuits through simulation. Copyright © 2008 John Wiley & Sons, Ltd.
Understanding patellofemoral pain with maltracking in the presence of joint laxity: Complete 3D in vivo patellofemoral and tibiofemoral kinematics
Authors: Sheehan Frances T. , Derasari Aditya , Brindle Timothy J. , Alter Katharine E.
Published: November 2008

Patellofemoral pain is widely accepted as one of the most common pathologies involving the knee, yet the etiology of this pain is still an open debate. Generalized joint laxity has been associated with patellofemoral pain, but is not often discussed as a potential source of patellar maltracking. Thus, the objective of this study was to compare the complete 6 degree of freedom patellofemoral and tibiofemoral kinematics from a group of patients diagnosed with patellofemoral pain syndrome and maltracking to those from an asymptomatic population. The following null hypotheses were tested: kinematic alterations in patellofemoral maltracking are limited to the axial plane; knee joint kinematics are the same in maltrackers with and without generalized joint laxity (defined by a clinical diagnosis of Ehlers Danlos Syndrome); and no correlations exist between tibiofemoral and patellofemoral kinematics or within patellofemoral kinematics. This study demonstrated that alterations in patellofemoral kinematics, associated with patellofemoral pain, are not limited to the axial plane, minimal correlations exist between patellofemoral and tibiofemoral kinematics, and distinct subgroups likely exist within the general population of maltrackers. Being able to identify subgroups correctly within the omnibus diagnosis of patellar maltracking is a crucial step in correctly defining the pathophysiology and the eventual treatment of these patients. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27: 561–570, 2009
Policosanol content and composition of wheat varieties as affected by environment
Authors: Chen Yongfen , T Dunford Nurhan , Edwards Jeff , Carver Brett , Goad Carla
Published: November 2008

BACKGROUND: Policosanol (PC) is a mixture of high‐molecular‐weight aliphatic primary saturated alcohols which possesses cholesterol‐lowering properties. Literature on PC contents and compositions of wheat varieties is limited. The main objective of this study was to evaluate the effect of genotype and environment on PC content and composition in wheat grain.

RESULTS: Grain samples were collected from three varieties, Jagger, Trego and Intrada, grown at three locations, Alva, Balko and Goodwell, OK, in 2005. Two sets of samples were obtained from Goodwell (irrigated and dryland samples). Total PC content and PC composition in whole wheat grain samples were determined using a gas chromatography system. PC contents of the whole wheat grain samples varied from 15.9 to 28.7 mg kg−1. Tricosanol, tetracosanol, hexacosanol, octacosanol and triacontanol were the most abundant PC components. Within each location a significant variety effect was observed. There was also a significant location × variety random effect on PC content.

CONCLUSION: A fundamental understanding of compositional variation in wheat grain requires multi‐environment testing of genotypes, perhaps over several years. This study is the first step towards achieving this goal by revealing significant genetic differences in a limited set of genotypes. Copyright © 2008 Society of Chemical Industry
Metal cations for the determination of fluorescent phosphoinositides by capillary electrophoresis
Authors: Otieno Anthony C. , Quainoo Emmanuel W. , Mwongela Simon M.
Published: November 2008

Phosphatidylinositol (PI) and its phosphorylated derivatives known as phosphoinositides (PIPs), are essential regulators of cell signaling and membrane trafficking, cytoskeletal dynamics, and nuclear functions. Disruption of PI metabolism is associated with disorders such as immune dysfunction, cardiovascular disease, and cancer; therefore, there is currently great interest in studying PIPs and their metabolic enzymes. Here, we describe a method for the separation of fluorescent PI and its seven fluorescent phosphorylated derivatives by CE‐LIF. The CE method utilizes a Tris buffer and sodium deoxycholate in the presence of 30% 1‐propanol and 5% of a dynamic coating reagent, EOTrolTMlow reverse (EOTrol LR). It is simple, fast, highly sensitive, and it offers LODs in the order of 1.5 amol. The effect of cations such as lithium, sodium, potassium, cesium, barium, manganese, zinc, magnesium, calcium, spermine, and gentamicin were evaluated. Calcium and magnesium provided the best selectivity and resolution for the separation of the analytes while magnesium offered the best data reproducibility. The developed CE method would be useful in the studies of enzymatic activity in the PI and PIPs metabolic pathways using CE‐basedin vitroand CE cell‐based assays, and/or for drug screening.
Thermo‐Responsive Polyoxazolines with Widely Tuneable LCST
Authors: Diehl Christina , Schlaad Helmut
Published: November 2008

The “click” modification of statistical poly[2‐(isopropyl/3‐butenyl)‐2‐oxazoline] copolymers with ω‐functionalized thiols can be used to generate a toolbox of thermo‐responsive polymers. The cloud points of the polymers can be finely tuned over a wide range as a function of composition and hydrophilicity of the side chain (hydrocarbon, alcohol, carboxylic acid, etc.). Glycopolymers can be prepared exhibiting predictable cloud points in the whole accessible temperature range for water.

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Low Bandgap Polymers by Copolymerization of Thiophene with Benzothiadiazole
Authors: He Youjun , Wang Xiang , Zhang Jing , Li Yongfang
Published: November 2008

Three low bandgap copolymers of thiophene and benzothiadiazole with electron‐donating and electron‐withdrawing substituents, P1, P2, and P3, have been synthesized by Pd‐catalyzed Stille‐coupling. Electronic energy levels of the polymers are estimated by cyclic voltammetry. The polymer films show a broad absorption band in the wavelength range from 300 to 750 nm. Among the polymers, the polymer that contains the 5,6‐dinitrobenzothiadiazole unit, P3, possesses the smallest bandgap of 1.55 eV calculated from its absorption band‐edge at ≈800 nm. With the increase of the electron‐withdrawing ability of the substituents on the benzothiadiazole unit, the energy bandgap of the polymers decreased in the order P1 > P2 > P3. The results indicate that stronger electron‐withdrawing substituents on the acceptor unit can effectively decrease the bandgap of the polymers.

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Polyethylene Nanocomposite Heat‐Sealants with a Versatile Peelable Character
Authors: Manias Evangelos , Zhang Jinguo , Huh Jin Young , Manokruang Kiattikhun , Songtipya Ponusa , Jimenez‐Gasco Maria Mar
Published: November 2008

A novel heat‐sealing performance is achieved by polyethylene (PE) nanocomposites reinforced by ethylene vinyl acetate (EVA) and montmorillonite (MMT). Appropriate nanocomposite design leads to hermetic seals with a general peelable/easy‐open character across the broadest possible sealing temperature range. Observations of the fracture seal surfaces by infrared spectroscopy and electron microscopy reveal that this behavior originates from a synergistic effect of the EVA copolymer and the montmorillonite clay nanofiller. Namely, the combination of EVA‐copolymers and MMT nanofillers provides sufficiently favorable interactions for nanocomposite formation and mechanical robustness, but weak enough interfacial adhesion to promote a general cohesive failure of the sealant at the EVA/MMT interfaces.

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Genotype–phenotype correlates in Taiwanese patients with early‐onset recessive parkinsonism
Authors: Lee Ming‐Jen , Mata Ignacio F. , Lin Chin‐Hsien , Tzen Kai‐Yuan , Lincoln Sarah J. , Bounds Rebecca , Lockhart Paul J. , Hulihan Mary M. , Farrer Matthew J. , Wu Ruey‐Meei
Published: November 2008

We screened for mutations in the PARKIN, DJ‐1, and PINK1 genes in a Taiwanese cohort (68 probands; 58 sporadic and 10 familial) with early‐onset parkinsonism (EOP, onset <50 years of age). We identified 9 patients harboring mutations in PARKIN (three compound heterozygous and six single heterozygous carriers), 3 patients with heterozygous PINK1 mutations (including two novel substitutions M341I and P209A), and no DJ‐1 mutations. Our frequencies of PARKIN (two allele mutation, 4.4%; single allele, 8.8%) and PINK1 (single heterozygous, 4.4%) mutations in Taiwanese–Chinese are similar to those in Caucasian and other Asian EOP patients. Although the role of heterozygosity of recessive genes in EOP remains to be resolved, molecular analysis and functional imaging will play a decisive role in differential diagnosis and determined therapeutic strategy. © 2008 Movement Disorder Society
Gait and balance in essential tremor: Variable effects of bilateral thalamic stimulation
Authors: Earhart Gammon M. , Clark B. Ruth , Tabbal Samer D. , Perlmutter Joel S.
Published: November 2008

Essential tremor (ET) is a multi‐faceted condition best known for postural and action tremor but also may include disordered gait and postural instability. Deep brain stimulation (DBS) of the ventral intermediate nucleus (VIM) of the thalamus provides substantial tremor reduction yet some patients with bilateral VIM DBS have gait and balance impairment. This study examines gait and balance performance in 13 participants with ET who have bilateral VIM DBS compared with a matched control group. Participants with ET were tested with their stimulators off (DBS OFF) and on (DBS ON). For both standard and tandem walking, participants with ET walked significantly more slowly than controls, with significantly lower cadence, spending a lower percentage of the gait cycle in single limb support and a higher percentage in double support compared with controls. Participants with ET also had significantly lower tandem and one leg stance times, Berg balance scores, balance confidence, and required significantly greater time to perform the Timed Up‐and‐Go relative to controls. There were no significant differences in any gait or balance measures in the DBS OFF versus DBS ON conditions, but the effects of DBS on gait and balance were highly variable among individuals. Future studies are needed to determine why some individuals experience gait and balance difficulties after bilateral thalamic DBS and others do not. A better understanding of the mechanisms underlying gait and balance impairments in those with bilateral DBS is critical to reduce falls and fractures in this group. © 2008 Movement Disorder Society
A novel wideband diversity antenna for mobile handsets
Authors: Cai Yaxing , Du Zhengwei , Gong Ke
Published: November 2008

A novel wideband printed diversity antenna for mobile handsets is proposed and studied. The antenna consists of two monopoles with symmetric configuration. The effects of some parameters of the proposed antenna are studied. The measured relative bandwidth reaches to 29.0% (1860–2490 MHz) with acceptable isolation over the bandwidth. The measured radiation patterns of the two monopoles cover complementary space regions. The diversity performance is approximately calculated, and the results show that the proposed antenna can provide spatial and pattern diversity. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 218–222, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23948
Self‐equalization technique for distributed quasi‐circulator
Authors: Mung Steve W. Y. , Chan Wing Shing
Published: November 2008

A self‐equalization technique for an active quasi‐circulator is proposed. It is formed using distributed amplifiers, which show how it achieves wideband frequency operation without the use of additional phase shifters. Experimental results show that it can operate over the frequency range 0.8–2.2 GHz. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 182–184, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23949
Shape reconstruction of an inhomogeneous impedance cylinder via potential and neural network approach
Authors: Yaman Fatih , Şimşek Serkan
Published: November 2008

In this article, a hybrid method is presented to reconstruct two‐dimensional shape of an inhomogeneous impedance cylinder from the noisy far field data in the case of single electromagnetic plane wave illumination. The proposed reconstruction method can also be applied for complex‐shaped smooth objects having different type of boundary conditions. For the solution of the direct problem, a potential (layer) approach is chosen that leads to a boundary integral equation. Applying Nyström method to the equation, an exponential convergence is obtained. The inverse scattering problem is solved via neural network approach, which is a stable technique under considerable level of noise. The applicability and the effectiveness of the proposed method are supported by numerical examples, and the proposed approach provides reconstructions which are in good agreement with the actual shapes. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 119–124, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23953
Quasi‐elliptic function filters with a dual‐passband response with high‐permittivity ceramics substrate
Authors: Huang Cheng‐Liang , Chen Yuan‐Bin , Lee Meng‐Lin
Published: November 2008

The miniaturization of dual‐passband filters by employing two high‐permittivity ceramic substrates (with respective dielectric constants of 4.5 and 20.8) are investigated. Microwave dielectric ceramics with high permittivity are commonly applied in several microwave communication components. With the advantages of compact size, high‐permittivity ceramics can be used as the substrate for dual‐passband filters. Moreover, the fundamental characteristics of newly developed compact stepped impedance resonator (SIR) have also been described and applied to the design of band‐pass filters. In this article, the designed ring resonators structures are simulated using an IE3D simulator. The responses of the fabricated dual‐passband filters using FR4 (εr= 4.5, Q × f = 350,000 GHz) and 0.96 Mg0.95CoTiO3–0.04SrTiO3with 1 wt% ZnO addition (εr= 20.8, Q × f = 74,000 GHz) ceramic substrates are designed at the center frequency of 2.4/5.2 GHz. This compact size, low loss dual‐passband filter should be useful in many wireless communication systems. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 245–248, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23962
An octagonal UWB monopole antenna with 5 GHz band‐notch function
Authors: Sim Chow‐Yen‐Desmond , Chung Wen‐Tsan , Lee Ching‐Her
Published: November 2008

In this article, an octagonal monopole antenna embedded with three slits in the ground plane is proposed. Its ultra‐wideband (UWB) operation within the required frequency (3.1–10.6 GHz) is fine tuned by embedding a small rectangular slit at the top center of the ground plane, whereas the band‐notch function is achieved by embedding two symmetrical L‐shaped slits located at both sides of the ground plane. The gain and time‐domain characteristics of this antenna show that it is applicable to any wireless communication system that requires a stable signal transmission in the 5‐GHz notch‐band‐excluded UWB. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 74–78, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23971
A novel microstrip UWB bandpass filter with CPW resonators
Authors: Chen H. , Zhang Y.‐X.
Published: November 2008

A new and compact ultra‐wideband (UWB) bandpass filter (BPF) using hybrid microstrip/coplanar waveguide (CPW) structure is proposed. The presented filter has been designed, fabricated, and measured for UWB system. Measured results demonstrated the UWB properties from 3.1 to 8.9 GHz (−3 dB bandwidth), which is fractional bandwidth of 96% at the center frequency 6.0 GHz. The filter also exhibits a sharper slop response at the lower passband edge than that reported in the article (Thomson and Hong, IEEE Microwave Wireless Compon Lett 17 (2007) 184–186), and deeper and wider stop‐band rejection than that reported in the article (Thomson and Hong, IEEE Microwave Wireless Compon Lett 17 (2007) 184–186; Li et al., IEEE MTT‐S Int Dig 2005, 675‐678) at the higher passband edge. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 24–26, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23977
Wideband cylindrical monopole antenna for multiband wireless applications
Authors: Chun Joong‐Chang
Published: November 2008

A wideband cylindrical monopole antenna is presented for multiple band applications. Wideband property of the proposed antenna is achieved by the additional resonance from a stepped base part and a convex ground plane. The measured −10 dB impedance bandwidths are 1.74–3.06 and 5.59–10.62 GHz, which can cover various kinds of wireless services such as PCS (1.75–1.87 GHz), IMT‐2000 (1.92–2.17 GHz), WiBro (2.3–2.39 GHz), WLAN (2.412–2.483 GHz, 5.725–5.825 GHz), DMB (2.63–2.655 GHz), and high‐band UWB in Korea (7.2–10.2 GHz). © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 15–17, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23981
A novel microstrip‐fed ultrawideband triangular monopole antenna with wide stubs
Authors: Choi Sung Tae , Hamaguchi Kiyoshi , Kohno Ryuji
Published: November 2008

A novel small size microstrip‐fed monopole antenna with wide bandwidth and small group delay variation is proposed for ultrawideband (UWB) applications. It consists of a triangular patch with a pair of wide stubs on the lower sides thereof and linearly tapered partial ground plane on the backside. The measured return loss of the fabricated antenna is better than −9 dB from 2.9 to 12 GHz. The radiation pattern is nearly omnidirectional, and the variation of the measured group delay between two proposed antennas is less than 1.6 ns over the entire UWB band. A good agreement is observed between measured and simulated results. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 263–266, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23989
Design of a compact branch‐line coupler using capacitance loading
Authors: Jing Tao , Shi Xiao‐Wei , Guo Yu‐Chun , Chen Lei , Chen Xiao‐Qun
Published: November 2008

This article presents a compact branch‐line coupler (BLC) for balanced‐type circuit application. It was designed by utilizing cascading multisection and capacitance‐loading technique for bandwidth increase and size reduction individually. The proposed BLC was simulated and fabricated. Its physical length reduces by 28.7%, while it performs as good as the conventional one. The simulated and the measured results have a good agreement. The method is valid for compact and good performance BLC design. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 198–200, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23992
Double‐layered coplanar patch antenna on CaLa4Ti5O17high‐permittivity substrate with coplanar waveguide feed line
Authors: Chen Yih‐Chien , Zeng Yu‐Wei
Published: November 2008

In this article, the measurement results for the double‐layered compact coplanar patch antenna with coplanar waveguide feed line at 2.5 GHz has been presented. With this technique, a 3.6% bandwidth (return loss < −10 dB) of center frequency at about 2.5 GHz has successfully been achieved. The copolarization radiation is strongest at θ ≅ 0° and 20° from the broadside in the xz‐ and yz‐planes, respectively. The antenna has a 3 dB beam angle of about 90°. Peak antenna gain is about 4.4 dBi, with gain variations less than 1.0 dBi for frequencies within in the −10‐dB S11bandwidth. From the measured return loss, it was demonstrated that the bandwidth of coplanar patch antenna printed on CaLa4Ti5O17high‐permittivity substrate with coplanar waveguide feed line on FR4 substrate can be improved compared with conventional patch antenna. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 98–100, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23998
Theory of the spherical generalized Smith chart
Authors: Wu Yongle , Zhang Yaxing , Liu Yuanan , Huang Haiyu
Published: November 2008

As a complement for the spherical representation of the Smith chart, this letter extends the previous work by giving the exact mathematical expressions of the spherical Smith chart and the spherical generalized Smith chart. Rigorous derivations and typical illustrations are also provided to support the theory. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 95–97, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23999
Characterization of photoconductive semiconductor switches under nonlinear mode condition
Authors: Ruan Chi , Zhao Wei , Zhu Shao‐Lan , Liu Hong‐Jun , Yang Hong‐Chun , Ruan Cheng‐Li
Published: November 2008

A photoconductive semiconductor switch (PCSS) would work in a nonlinear mode under high biased electrical field. The experimental results of nonlinear critical state have shown that both the biased voltage and the laser energy may have working thresholds to turn on the nonlinear modes. The relation between the biased voltage and the laser energy is inverse ratio, i.e., higher biased field need lower laser energy for nonlinear mode, and vise versa. At the nonlinear critical point, the output of PCSS is unstable, as both the linear and nonlinear pulse may occur. As the laser energy and biased field increase, the PCSS would work in the nonlinear mode steadily. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 56–59, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24001
Band‐notched UWB printed antenna with an inverted‐L‐slotted ground
Authors: Jiang Jun‐Bo , Song Yue , Yan Ze‐Hong , Zhang Xin , Wu Wei
Published: November 2008

A novel printed antenna having a frequency band‐notched function for UWB applications is proposed and studied. With a pair of inverted‐L‐shaped slots introduced around the microstrip line on the ground, a frequency‐notched response at 5.2 GHz is obtained. The designed antenna satisfies the VSWR requirement of less than 2.0 in the frequency band between 2.8 and 10.7 GHz while showing the band rejection performance in the frequency band from 4.8 to 5.7 GHz. Good monopole‐like radiation patterns and antenna gains have also been obtained. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 260–263, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24003
A new ultra wideband aperture coupled microstrip antenna
Authors: Ghassemi N. , Rashed‐Mohassel J. , Neshati M. H.
Published: November 2008

This letter presents a new aperture coupled microstrip antenna with a nonsymmetric U‐shaped feed line and two rectangular slots on the ground plane. Simulation results show that the antenna has VSWR <2 from 10.5 to 22 GHz and the simulated gain bandwidth (above 7 dB) of the antenna is 6.6 GHz (47%). Good agreement is obtained between simulation and experimental results. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 259–260, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24004
The three symmetric power divider ports, compact, fixed, and tunable based on micro‐strip technology
Authors: Jrad A. , Safarjalani T. , Duchamp J.‐M. , Ferrari P. , El‐Helwani A.
Published: November 2008

We produced three symmetric power divider ports, compact, fixed, and tunable based, with hybrid technology by using capacitors CMS or commercial diode varactors, at low costs. These dividers consist of an impedance transformer in the shape of T in entry and by two transmission lines with an impedance of 50 Ω on the two output ports. The impedance transformer contains a transmission line with electrical length θ1, a fixed capacitor C or variable (diode), and another transmission line with electrical length θ2. We designed these power dividers at working central frequencies 900 and 1800 MHz for GSM applications by using two substrates: Epoxy and RO4003. The band pass should be higher than 20% around central frequency for a good adaptation (S11< −20 dB) and also for losses lower than 0.3 dB. The size of our dividers is more than two times shorter than a classical Wilkinson power divider. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 229–232, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24005
Systematic design and realization of the optical feedforward transmitter based on microwave circuit modeling
Authors: Moon Yon‐Tae , Jang Jun Woo , Lee Tae‐Kyeong , Kim Do‐Gyun , Park Ho‐Hyun , Kang Tae‐Gu , Han Sang‐Kook , Choi Young‐Wan
Published: November 2008

We have systematically designed and realized the optical feedforward transmitter using microwave circuit model of distributed‐feedback laser diode (DFB LD) based on rate equations. Through the system‐level simulation for the optical feedforward method, the nonlinearity of DFB‐LD is analyzed, and the optimized characteristics of the RF components in the system are confirmed by using a microwave simulator. The experimental and simulated results show the reduced distortion products and enhanced spurious‐free dynamic ranges are in good agreement at 2.4 GHz. These results are analyzed as the evaluation parameters for the miniaturization and optimization of the feedforward compensation method in radio‐over‐fiber systems. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 192–195, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24007
Extended reciprocity‐based computation of mutual admittance between CPW‐fed slots on conductor‐backed two‐layer substrates
Authors: Jacobs Jan P. , Joubert Johan , Odendaal Johann W.
Published: November 2008

An extended reciprocity‐based formulation for finding mutual admittance between coplanar waveguide fed slots on conductor‐backed two‐layer substrates was presented. The formulation updates the field distribution in both slots iteratively to account for coupling interaction between slots. This is especially relevant for cases of high mutual coupling. The results agree well with moment method‐based calculations. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 91–94, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24012
Design of CPW‐fed monopole UWB antenna with a novel notched ground
Authors: Zhang Xin , Wu Wei , Yan Ze‐Hong , Jiang Jun‐Bo , Song Yue
Published: November 2008

A novel CPW‐fed monopole UWB antenna is presented in this article. To increase the impedance bandwidth, a notched ground is introduced. The parameters and the characteristics of the antenna are given. The optimized antenna presents 3.8:1 ratio bandwidth and 116.7% impedance bandwidth for VSWR less than 2. Simulations and measurements are presented for the proposed antenna. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 88–91, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24013
Novel compact ultra‐wideband filter with wide stop‐band
Authors: Hu Hong‐Hong , Xiao Zhong‐Yin , He Wen‐Qing , Gao Shan
Published: November 2008

One novel compact ultra‐wideband filter having high‐frequency selectivity and wide stopband is developed by using microstrip stub‐loaded dual‐mode resonator couples. Open stub‐loaded and short stub‐loaded are used to widen the passband of filter without aperture‐enhanced coupled line structure. Five transmission poles in the passband are shown. Two sharp attenuation poles can be located close to either side of the desired pass band. And the other two attenuation poles can be located in the stopband of upper frequencies, so as to reject the third resonant modes of stub‐loaded resonators. The passband of filter and the locations of attenuation poles can be controlled by the sizes of the open stub and short stub. The measured results demonstrate that the insertion loss is lower than 1.0 dB in the passband (3.9–11.6 GHz), higher than 15.0 dB in the upper‐stopband (12.0–19.5 GHz), whereas the group delay variation in the passband is less than 0.5 ns. The measured result agrees well with the EM simulation. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 53–55, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24014
Efficient electrically small loop antenna using SRR structure on the ground plane
Authors: Kim Joong‐Kwan , Kim Yong‐Jin , Kim Ho‐Yong , Lee Hong‐Min
Published: November 2008

In this article, an electrically small loop antenna using capacitive loading is proposed. The loop antenna acts as an inductive element and the gap between two lines of SRR in the ground plane acts as a capacitive element; hence the combined system with these two elements is operated as a LC resonator. The equivalent circuit model of the antenna structure is applied to analyze and qualify the design correctness. Although the proposed antenna has a very small size, it shows a good performance. The measured maximum gain and radiation efficiency of the fabricated antenna at the frequency of 2.04 GHz are 3.6 dBi and 81.02%, respectively. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 201–204, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24016