bluuebunny/crossref_metadata_2025 huggingface dataset:
Clinical correlates of Parkinsonian signs in community‐ dwelling Chinese older persons: a population based study
Authors: Tam Cindy W. C. , Lam Linda C. W. , Lui Victor W. C. , Chan W. C. , Chan Sandra S. M. , Chiu Helen F. K. , Chan W. M.
Published: January 2008

Background and objective

This study examined the clinical correlates of parkinsonian signs including neuropsychiatric symptoms, cognitive impairment and medical illness burden in the community‐dwelling non‐demented Chinese elderly.

Methods

A random sample of 765 Chinese elderly subjects from a thematic household survey was recruited. There were 389 normal elderly controls (Clinical Dementia Rating [CDR] 0) (NC) and 376 subjects with questionable dementia (CDR 0.5). The subjects with questionable dementia (CDR 0.5) were categorized into two groups: a MCI group (n = 291) and a very mild dementia (VMD) group (n = 85). Parkinsonian signs were measured by Unified Parkinson Disease Rating Scale‐ motor scale (UPDRS). The clinical correlates were investigated in each group.

Results

UPDRS motor score was associated with age, cumulative medical illness burden and cerebrovascular accidents in the normal control and MCI groups. It correlated negatively with MMSE scores in the NC group. It was associated with presence of soft signs in the NC and MCI groups; and apathy in the VMD group.

Conclusion

Neuropsychiatric symptoms, cognitive impairment and vascular risk factors had different patterns of associations with parkinsonian signs in the older persons with different degree of cognitive impairment. Copyright © 2008 John Wiley & Sons, Ltd.
Persistent default‐mode network connectivity during light sedation
Authors: Greicius Michael D. , Kiviniemi Vesa , Tervonen Osmo , Vainionpää Vilho , Alahuhta Seppo , Reiss Allan L. , Menon Vinod
Published: January 2008

The default‐mode network (DMN) is a set of specific brain regions whose activity, predominant in the resting‐state, is attenuated during cognitively demanding, externally‐cued tasks. The cognitive correlates of this network have proven difficult to interrogate, but one hypothesis is that regions in the network process episodic memories and semantic knowledge integral to internally‐generated mental activity. Here, we compare default‐mode functional connectivity in the same group of subjects during rest and conscious sedation with midazolam, a state characterized by anterograde amnesia and a reduced level of consciousness. Although the DMN showed functional connectivity during both rest and conscious sedation, a direct comparison found that there was significantly reduced functional connectivity in the posterior cingulate cortex during conscious sedation. These results confirm that low‐frequency oscillations in the DMN persist and remain highly correlated even at reduced levels of consciousness. We hypothesize that focal reductions in DMN connectivity, as shown here in the posterior cingulate cortex, may represent a stable correlate of reduced consciousness. Hum Brain Mapp, 2008. © 2008 Wiley‐Liss, Inc.
Crystalline Structure of Mangiferin, a C‐Glycosyl‐Substituted 9H‐Xanthen‐9‐one Isolated from the Stem Bark of Mangifera indica
Authors: da Cruz José W. , de Moraes Lucas R. , dos Santos Marcelo H. , da Silva Geraldo Alves , Brigagão Maisa R. P. L. , Ellena Javier , Doriguetto Antonio C.
Published: January 2008

The crystalline structure of mangiferin (=2‐β‐D‐glucopyranosyl‐1,3,6,7‐tetrahydroxy‐9H‐xanthen‐9‐one; 1), a biologically active xanthenone C‐glycoside, isolated from the stem bark of Mangifera indica (Anacardiaceae), was unambiguously determined by single‐crystal X‐ray diffraction (XRD). The crystal structure is summarized as follows: triclinic, P1, a=7.6575(5), b=11.2094(8), c=11.8749(8) Å, α=79.967(5), β=87.988(4), γ=72.164(4)°, V=955.3(1) Å3, and Z=2. The structure also shows two molecules in the asymmetric unit cell and five crystallization H2O molecules. The packing is stabilized by several intermolecular H‐bonds involving either the two symmetry‐independent mangiferin molecules 1a and 1b, or the H2O ones.
Three New Sesquiterpenoids from Xylaria sp. NCY2
Authors: Hu Zhi‐Yu , Li Yao‐Yao , Huang Yao‐Jian , Su Wen‐Jin , Shen Yue‐Mao
Published: January 2008

Three new sesquiterpenoids, xylarenones A (1) and B (2), and xylarenic acid (3), were obtained from the endophytic fungal strain Xylaria sp. NCY2, which was isolated from Torreya jackii Chun. Their structures were elucidated by spectroscopic analyses, including 1D‐ and 2D‐NMR experiments, and by HR‐Q‐TOF mass spectrometry. The antitumor and antibacterial properties of the new compounds were evaluated.
Unexpected Novel Pheophytin Peroxides from the Leaves of Biden pilosa
Authors: Lee Tzong‐Huei , Lu Chung‐Kuang , Kuo Yueh‐Hsiung , Lo Jir‐Mehng , Lee Ching‐Kuo
Published: January 2008

Two new pheophytins, bidenphytins A (1) and B (2), with peroxide functionalities on ring E, were isolated from Biden pilosa Linn. var. radiata Sch. Bip., a popular Taiwanese folk medicine. Also isolated were the following six known compounds: pheophytin a (3), (132R)‐132‐hydroxypheophytin a (4), (132S)‐132‐hydroxypheophytin a (5), (132R)‐132‐hydroxypheophytin b (6), (132S)‐132‐hydroxypheophytin b (7), and aristophyll‐C (8). Their structures were elucidated by spectroscopic methods (UV, IR, 1D‐ and 2D‐NMR) and by mass spectrometry (HR‐FAB‐MS). Possible biosynthetic pathways for 1 and 2 are proposed.
Effects of selective and combined serotonin and dopamine depletion on the loudness dependence of the auditory evoked potential (LDAEP) in humans
Authors: O'Neill Barry V. , Guille Valérie , Croft Rodney J. , Leung Sumie , Scholes Kirsty E. , Phan K. Luan , Nathan Pradeep J.
Published: January 2008

Background

The loudness dependence of the auditory evoked potential (LDAEP) has been suggested as a possible in vivo measure of central serotonin function. However, more recent studies suggest that the LDAEP may be modulated by multiple neuromodulatory systems in addition to the serotonergic system. Accordingly we further examined the effects of selective serotonin, dopamine and simultaneous serotonin and dopamine depletion on the LDAEP in healthy subjects.

Methods

The study employed a placebo‐controlled, double‐blind, cross over design. Fourteen subjects were tested under four acute treatment conditions: placebo (balanced amino acid drink), tryptophan (serotonin) depletion (ATD), tyrosine/phenylalanine (dopamine) depletion (ATPD) and combined tryptophan/tyrosine/phenylalanine (serotonin and dopamine) depletion (CMD). Testing was conducted 5.5 h post‐depletion and changes in the amplitude of the N1/P2 at varying intensities (60, 70, 80, 90, 100 dB) were examined at CZ.

Results

Greater than 80% plasma precursor depletion was achieved across all conditions. Despite significant depletion of monoamine precursors, ATD, (p = 0.318), ATPD (p = 0.061) and CMD (p = 0.104) had no effects on the LDAEP (60–100 dB).

Conclusion

Acute serotonin and dopamine depletion did not modulate the LDAEP. This finding adds support to growing evidence that the LDAEP is insensitive to acute changes in serotonin and dopamine neurotransmission. Copyright © 2008 John Wiley & Sons, Ltd.
Selenium transport and transformation modelling in soil columns and ground water contamination prediction
Authors: Mirbagheri Seyed Ahmad , Tanji Kenneth K. , Rajaee Taher
Published: January 2008

Selenium transport and transformation were simulated in a soil column. A one‐dimensional dynamic mathematical and computer model is formulated to simulate, selenate, selenite, selenomethionine, organic selenium, and gaseous selenium. This computer model is based on the mass balance equation, including convective transport, dispersive transport, surface adsorption, oxidation and reduction, volatilization, chemical and biological transformation. The mathematical solution is obtained by the finite difference implicit method. The model was verified by comparison of model results with experimental measurements and also using mass balance calculations in each time step of calculation. For example after 4 days of simulation, the simulated value of adsorbed selenate for depth of 20 cm is 0·2 µmol kg−1 and the measured value is 0·25 µmol kg−1. Therefore simulated results are in good agreement with measured values. With this study and its results the distribution of various forms of selenium in soil column to ground water table can be predicted. Copyright © 2008 John Wiley & Sons, Ltd.
Fire effects on rangeland hydrology and erosion in a steep sagebrush‐dominated landscape
Authors: Pierson Frederick B. , Robichaud Peter R. , Moffet Corey A. , Spaeth Kenneth E. , Hardegree Stuart P. , Clark Patrick E. , Williams C. Jason
Published: January 2008

Post‐fire runoff and erosion from wildlands has been well researched, but few studies have researched the degree of control exerted by fire on rangeland hydrology and erosion processes. Furthermore, the spatial continuity and temporal persistence of wildfire impacts on rangeland hydrology and erosion are not well understood. Small‐plot rainfall and concentrated flow simulations were applied to unburned and severely burned hillslopes to determine the spatial continuity and persistence of fire‐induced impacts on runoff and erosion by interrill and rill processes on steep sagebrush‐dominated sites. Runoff and erosion were measured immediately following and each of 3 years post‐wildfire. Spatial and temporal variability in post‐fire hydrologic and erosional responses were compared with runoff and erosion measured under unburned conditions. Results from interrill simulations indicate fire‐induced impacts were predominantly on coppice microsites and that fire influenced interrill sediment yield more than runoff. Interrill runoff was nearly unchanged by burning, but 3‐year cumulative interrill sediment yield on burned hillslopes (50 g m−2) was twice that of unburned hillslopes (25 g m−2). The greatest impact of fire was on the dynamics of runoff once overland flow began. Reduced ground cover on burned hillslopes allowed overland flow to concentrate into rills. The 3‐year cumulative runoff from concentrated flow simulations on burned hillslopes (298 l) was nearly 20 times that measured on unburned hillslopes (16 l). The 3‐year cumulative sediment yield from concentrated flow on burned and unburned hillslopes was 20 400 g m−2 and 6 g m−2 respectively. Fire effects on runoff generation and sediment were greatly reduced, but remained, 3 years post‐fire. The results indicate that the impacts of fire on runoff and erosion from severely burned steep sagebrush landscapes vary significantly by microsite and process, exhibiting seasonal fluctuation in degree, and that fire‐induced increases in runoff and erosion may require more than 3 years to return to background levels. Published in 2008 by John Wiley & Sons, Ltd.
Quantitation of HER2 and telomerase biomarkers in solid tumors with IgY antibodies and nanocrystal detection
Authors: Xiao Yan , Gao Xiugong , Gannot Gallya , Emmert‐Buck Michael R , Srivastava Sudhir , Wagner Paul D. , Amos Michael D. , Barker Peter E.
Published: January 2008

In an effort to improve affinity biomarker validation in fixed patient tissue specimens, we have developed a novel quantum dot‐based bioimaging system that utilizes chicken IgY antibody for high sensitivity and specificity relative quantitation of cancer proteins. Monospecific, polyclonal IgYs were generated against human HER2 and telomerase, and analytically validated for specificity by western blot and immunohistochemistry on tumor and normal cells and for relative affinity by layered peptide array (LPA). IgYs bound desired targets in cell lines and fixed tissues and showed greater affinity than commercial mammalian antibodies for both HER2 and telomerase proteins. In tissue microarray experiments, HER2 quantitation with IgY antibody and quantum dot imaging correlated well with chromogenic in situ hybridization (CISH), whereas telomerase quantitation suggested a trend toward correlation with prostate cancer Gleason Grade and differentiation. Although patient numbers were small, these findings demonstrate the feasibility of relative quantitation of cancer biomarkers with IgY and quantum dot fluorophores, and show promise for rigorous clinical validation in large patient cohorts. © 2008 Wiley‐Liss, Inc.
Site‐specific analysis of N‐glycans on haptoglobin in sera of patients with pancreatic cancer: A novel approach for the development of tumor markers
Authors: Nakano Miyako , Nakagawa Tsutomu , Ito Toshifumi , Kitada Takatoshi , Hijioka Taizo , Kasahara Akinori , Tajiri Michiko , Wada Yoshinao , Taniguchi Naoyuki , Miyoshi Eiji
Published: January 2008

It was found in our previous studies that the concentration of fucosylated haptoglobin had increased in the sera of patients with pancreatic cancer (PC) compared to those of other types of cancer and normal controls. Haptoglobin, an acute phase protein, has four potential N‐glycosylation sites, although it remains unknown which site is responsible for the change in fucosylated N‐glycans. In the present study, site‐specific N‐glycan structures of haptoglobin in sera obtained from patients with PC or chronic pancreatitis (CP) were analyzed using liquid chromatography‐electrospray ionization mass spectrometry. Mass spectrometry analyses demonstrated that concentrations of total fucosylated di‐, tri‐ and tetra‐branched glycans of haptoglobin increased in the sera of PC patients. Tri‐antennary N‐glycans containing a Lewis X‐type fucose markedly increased at the Asn211 site of haptoglobin N‐glycans. While fucosylated N‐glycans derived from serum haptoglobin of patients with CP slightly increased, di‐fucosylated tetra‐antennary N‐glycans were observed only at this site in PC patients, and were absent in the haptoglobin of normal controls and individuals with CP. Thus, the present study provides evidence that site‐specific analyses of N‐glycans may be useful as novel tumor markers for PC. © 2008 Wiley‐Liss, Inc.
The Inuit cancer pattern—The influence of migration
Authors: Boysen Trine , Friborg Jeppe , Andersen Andreas , Nilsson Poulsen Gry , Wohlfahrt Jan , Melbye Mads
Published: January 2008

The Inuit cancer pattern is characterized by high frequencies of Epstein–Barr Virus (EBV)‐associated carcinomas of the nasopharynx and salivary glands. The reasons are unknown, but genetic and environmental factors are believed to be involved. Using data from the well‐defined Inuit population in Greenland we investigated whether migration to Denmark influenced their risk of cancer. Greenland is part of the Danish Kingdom, and population‐based registries cover both countries. Using rates for Denmark as reference, sex‐specific standardized incidence ratios (SIR) were calculated for Inuit who never lived in Denmark and for those who at least once were registered with a Danish address. During 1973–2003, we observed 3,567 cancers in a cohort of 77,888 persons. Of these, 862 among 26,214 Inuit ever living in Denmark, and 2,705 among 51,674 nonmigrating Inuit. High SIRs for cancers of the nasopharynx [31.7 (CI 22.0‐45.5)] and salivary glands [3.1 (CI 1.4–6.9)] observed among Inuit migrating to Denmark were comparable to those observed among Inuit never living in Denmark. Significant higher risk of cancer of the bladder, breast, prostate gland, skin, brain and stomach was observed among Inuit following migration to Denmark. The SIR was not generally influenced by duration of stay. The high risk of carcinoma of the nasopharynx and salivary glands observed in Inuit populations is maintained after migration to a low incidence area. This indicates that genetic factors or environmental factors acting early in life are etiologically important for these cancers. © 2008 Wiley‐Liss, Inc.
Inhibition of sulfide on the simultaneous removal of nitrate and p‐cresol by a denitrifying sludge
Authors: Meza‐Escalante Edna R , Texier Anne‐Claire , Cuervo‐López Flor , Gómez Jorge , Cervantes Francisco J
Published: January 2008

BACKGROUND: Many industrial discharges, such as those generated from petrochemical refineries, contain large amounts of sulfurous, nitrogenous and organic contaminants. Denitrification has emerged as a suitable technology for the simultaneous removal of these pollutants in a single reactor unit; however, more evidence is demanded to clarify the limitations of denitrification on the simultaneous removal of sulfide and phenolic contaminants and to optimize the biological process. The aim of this study was to evaluate the capacity of a denitrifying sludge to simultaneously convert sulfide and p‐cresol via denitrification.

RESULTS: Sulfide was the preferred electron donor over p‐cresol, imposing a 5 h lag phase (required for complete sulfide removal) on organotrophic denitrification. Addition of sulfide (20 mg S2− L−1) to p‐cresol‐amended denitrifying cultures also decreased the reduction rate of nitrate and nitrite, as well as the production rate of nitrogen gas. Nitrite reduction rate was the most affected step by sulfide, decreasing from 35 to 21 mg N (g VSS d)−1. A synergistic inhibitory effect of nitrate and sulfide was also observed on nitrite reduction. Despite the effects of sulfide on the respiratory rates monitored, complete removal of nitrate, sulfide and p‐cresol could be achieved after 48 h of incubation.

CONCLUSION: Our results suggest that simultaneous removal of sulfide and p‐cresol could be achieved in denitrifying reactors, but a large hydraulic residence time may be required to sustain an efficient process due to inhibitory effects of sulfide. Copyright © 2008 Society of Chemical Industry
Nidogens—Extracellular matrix linker molecules
Authors: HO Matthew S.P. , Böse Kerstin , Mokkapati Sharada , Nischt Roswitha , Smyth Neil
Published: January 2008

Nidogens/entactins are a family of highly conserved, sulfated glycoproteins. Biochemical studies have implicated them as having a major structural role in the basement membrane. However despite being ubiquitous components of this specialized extracellular matrix and having a wide spectrum of binding partners, genetic analysis has shown that they are not required for the overall architecture of the basement membrane. Rather in development they play an important role in its stabilization especially in tissues undergoing rapid growth or turnover. Nidogen breakdown has been implicated as a key event in the basement membrane degradation occurring in mammary gland involution. A number of studies, most compellingly those in C. elegans, demonstrated that nidogens may have other nonstructural roles and be involved in axonal pathfinding and synaptic transmission. Microsc. Res. Tech., 2008. © 2008 Wiley‐Liss, Inc.
3‐T imaging of the cranial nerves using three‐dimensional reversed FISP with diffusion‐weighted MR sequence
Authors: Zhang Zhongwei , Meng Quanfei , Chen Yingming , Li Ziping , Luo Boning , Yang Zhiyun , Mao Lijuan , Lin Erjian
Published: January 2008

Purpose

To depict the normal anatomy of cranial nerves in detail and define the exact relationships between cranial nerves and adjacent structures with three‐dimensional reversed fast imaging with steady‐state precession (FISP) (3D‐PSIF) with diffusion‐weighted MR sequence.

Materials and Methods

3D‐PSIF with diffusion‐weighted MR sequence was performed and axial images were obtained in 22 healthy volunteers. Postprocessing techniques were used to generate images of cranial nerves, and the images acquired were compared with anatomical sections and textbook diagrams.

Results

In all subjects, 3D‐PISF sequence could produce homogeneous images and high contrast between the cranial nerves and other solid structures. The intracranial portions of all cranial nerves except the olfactory nerve were identified; the extracranial portions of nerves II–XII, except the nerves within the cavernous sinuses, were identified in all subjects bilaterally.

Conclusion

The 3D‐PSIF with diffusion‐weighted sequence can characterize the normal MR appearance of cranial nerves and its branches. The ability to define the nerves may provide greater sensitivity and specificity in detecting abnormalities of craniofacial structure. J. Magn. Reson. Imaging 2008. © 2008 Wiley‐Liss, Inc.
Current status and future potential of MRI‐guided focused ultrasound surgery
Authors: Jolesz Ferenc A. , McDannold Nathan
Published: January 2008

The combination of the imaging abilities of magnetic resonance imaging (MRI) with the ability to delivery energy to targets deep in the body noninvasively with focused ultrasound presents a disruptive technology with the potential to significantly affect healthcare. MRI offers precise targeting, visualization, and quantification of temperature changes and the ability to immediately evaluate the treatment. By exploiting different mechanisms, focused ultrasound offers a range of therapies, ranging from thermal ablation to targeted drug delivery. This article reviews recent preclinical and tests clinical of this technology. J. Magn. Reson. Imaging 2008;27:391–399. © 2008 Wiley‐Liss, Inc.
MR‐guided intravascular interventions: Techniques and applications
Authors: Bock Michael , Wacker Frank K.
Published: January 2008

Magnetic resonance imaging (MRI) offers several advantages over other imaging modalities that make it an attractive imaging tool for diagnostic and therapeutic procedures. This tremendous potential of MRI has provided the rationale for increased attention toward MR‐guided endovascular interventions. MR guidance has been used recently to navigate endovascular catheters and deliver stents, vena cava filters, embolization materials, and septum closure devices. However, its potential goes beyond just copying existing procedures toward the development of new minimally invasive techniques that cannot be performed with conventional guiding techniques. Because of technical limitations and safety issues associated with some of the currently available devices, a limited number of clinical studies have been performed so far. The overall success for this developing field requires considerable interdisciplinary research within both the interventional and the MR community. Only through a combined effort can this complex technology find its way into clinical practice. This review discusses the hardware and software improvements that have helped to advance endovascular interventions under MR imaging guidance from a pure research tool to become a clinical reality. In addition, technical and safety issues specific to endovascular MR image guidance will be described and practical applications will be shown that take advantage of the benefits of MR for endovascular interventions. J. Magn. Reson. Imaging 2008;27:326–338. © 2008 Wiley‐Liss, Inc.
MRI‐guided interventions of the musculoskeletal system
Authors: Smith Kevin A. , Carrino John
Published: January 2008

MRI has become the modality of choice for many diagnostic questions in musculoskeletal radiology. Naturally, with the increasing role of MRI in diagnosis of musculoskeletal conditions, clinicians have been eager to explore the possibility of using MR guidance for musculoskeletal procedures. Researchers are actively investigating the utility and practicality of MRI compared with more established modalities for procedure guidance such as computed tomography, fluoroscopy, and ultrasound. Early studies have demonstrated the safety and feasibility of MR guidance for biopsies, spine procedures, cyst aspirations, therapeutic injections, and tumor ablation. Applications in the musculoskeletal system are likely to expand as technology improves and clinicians gain more experience. Hybrid X‐ray fluoroscopy/MR imaging systems hold great promise for the future of musculoskeletal intervention by combining the excellent temporal and spatial resolution of X‐ray with the anatomic detail provided by MRI. J. Magn. Reson. Imaging 2008;27:339–346. © 2008 Wiley‐Liss, Inc.
Direct Synthesis of PVA‐g‐PDMS in Microsuspension
Authors: Pouget Emmanuel , Garcia Erlea Holgado , Ganachaud François
Published: January 2008

The synthesis of P(VA‐co‐VAc)‐graft‐PDMS copolymers has been achieved in microsuspension by direct reaction between an epoxy‐terminated PDMS and some pendant alcohol groups in P(VA‐co‐VAc). In this synthesis, the copolymer is used both as dispersant and reactant. The hydrophilic/hydrophobic character of the final material can be varied at will by incorporating various contents of epoxy‐functionalized PDMS through optimized reaction conditions. The final composition was determined by TGA and 1H NMR. Products prepared from monofunctional PDMS were easily redispersed in water whereas a film of crosslinked materials, arising from difunctional PDMS, showed the best waterproofing as shown by contact angle analysis.

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Synthesis of Peptide/Polymer Conjugates by Solution ATRP of Butylacrylate Using an Initiator‐Modified Cyclic D‐alt‐L‐Peptide
Authors: Loschonsky Sidar , Couet Julien , Biesalski Markus
Published: January 2008

Peptide/polymer hybrid molecules consisting of poly(butylacrylate) chains, covalently attached to a cyclic D‐alt‐L‐octapeptide, were prepared by the in situ ATRP of butylacrylate using a cyclic peptide that was modified at three distinct positions with an initiator group. The apparent molar mass of the peptide/PBA hybrid molecules could be controlled through adjusting the reaction conversion. The hybrid molecule showed a solvent induced self‐assembly, which yielded rod‐like nanostructures having a core shell morphology with an internal beta‐sheet peptide assembly surrounded by a soft PBA exterior.

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Modifizierte Nickelbasisstandardlote für korrosiv belastete Bauteile
Authors: Wielage B. , Hoyer I.
Published: January 2008

Zum Fügen korrosiv hoch beanspruchter Bauteile, wie z. B. Industrie‐Wärmetauscher, werden häufig Nickelbasislote verwendet. Bei herkömmlichen Ni‐Basis‐Lotlegierungen mit Zusätzen von Bor und Silizium kommt es beim Löten von chromhaltigen Stählen aufgrund der hohen Affinität von Chrom zu Bor häufig zur Bildung von Chromboriden, die sich insbesondere an den Korngrenzen ausscheiden. Das führt zu einer Chrom‐Verarmung im Grundwerkstoff und kann – sinkt der Chromgehalt unter den kritischen Wert von 13 % ab – den Verlust der Korrosionsbeständigkeit nach sich ziehen.

Durch Modifikation mit Chrom und Molybdän wurde die Gefügeausbildung der Lötnähte an nichtrostenden austenitischen Stählen derart verändert, dass keine durchgehenden Sprödphasen mehr auftraten. Es wurde gezeigt, dass die Wahl der Zusatzwerkstoffe und die Parameter Löttemperatur, Aufheiz‐ und Abkühlgeschwindigkeit einen wesentlichen Einfluss auf die Gefügeausbildung und damit auf die mechanischen und korrosiven Eigenschaften der Verbindungen haben.
Clinical assessment of CYP2D6‐mediated herb–drug interactions in humans: Effects of milk thistle, black cohosh, goldenseal, kava kava, St. John's wort, andEchinacea
Authors: Gurley Bill J. , Swain Ashley , Hubbard Martha A. , Williams D. Keith , Barone Gary , Hartsfield Faith , Tong Yudong , Carrier Danielle J. , Cheboyina Shreekar , Battu Sunil K.
Published: January 2008

Cytochrome P450 2D6 (CYP2D6), an important CYP isoform with regard to drug–drug interactions, accounts for the metabolism of ∼︁30% of all medications. To date, few studies have assessed the effects of botanical supplementation on human CYP2D6 activityin vivo. Six botanical extracts were evaluated in three separate studies (two extractsperstudy), each incorporating 16 healthy volunteers (eight females). Subjects were randomized to receive a standardized botanical extract for 14 days on separate occasions. A 30‐day washout period was interposed between each supplementation phase. In study 1, subjects received milk thistle (Silybum marianum) and black cohosh (Cimicifuga racemosa). In study 2, kava kava (Piper methysticum) and goldenseal (Hydrastis canadensis) extracts were administered, and in study 3 subjects received St. John's wort (Hypericum perforatum) andEchinacea(Echinacea purpurea). The CYP2D6 substrate, debrisoquine (5 mg), was administered before and at the end of supplementation. Pre‐ and post‐supplementation phenotypic trait measurements were determined for CYP2D6 using 8‐h debrisoquine urinary recovery ratios (DURR). Comparisons of pre‐ and post‐supplementation DURR revealed significant inhibition (∼︁50%) of CYP2D6 activity for goldenseal, but not for the other extracts. Accordingly, adverse herb–drug interactions may result with concomitant ingestion of goldenseal supplements and drugs that are CYP2D6 substrates.
Aperture‐coupled cavity‐fed back‐to‐back microstrip directional coupler
Authors: Nam Sang Ho , Nam Kyung Min , Kim Chul Un , Kim Jeong Phill
Published: January 2008

An analysis and design theory of an aperture‐coupled cavity‐fed back‐to‐back microstrip directional coupler is presented for efficient and optimized design. For this purpose, an equivalent network is developed, and a simple yet accurate circuit element value calculation is described. Design equations of the coupler are derived based on the equivalent circuit. To determine various structural design parameters, the evolutionary hybrid optimization method based on a genetic algorithm and the Nelder–Mead method is used. As a validation check of the proposed theory and optimized design method, a 10 dB directional coupler was designed and fabricated. The measured coupling was 10.3 dB at 3 GHz, and the return loss and isolation were 31.8 dB and 30.5 dB, respectively. The directional coupler also showed very good quadrature phase characteristics. Good agreements between the measured and the design specifications fully validate the proposed network analysis and design procedure. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 551–555, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23145
Particle swarm optimization with tournament selection for linear array synthesis
Authors: Pérez J. R. , Basterrechea J.
Published: January 2008

The modern heuristic particle swarm optimization technique (PSO) has received great attention in many applications and research areas over the last few years, and novel PSO‐based algorithms are continuously emerging to improve its overall performance. In this article, classical PSO schemes are modified by introducing a selection operator widely used in evolutionary algorithms such as genetic algorithms, and these novel hybrid algorithms are applied to linear array synthesis using complex weights and considering directive element patterns to weigh up the improvements achieved. Up to eight classical PSO schemes are addressed by the PSO suite tested in this work, including PSO with synchronous and asynchronous updates of the swarm along with global and local topologies for both, real‐valued and binary encoding algorithms. Furthermore, representative results comparing both classical PSO schemes and the new hybrid approaches are reported and discussed, demonstrating that the selection operator clearly increases search pressure over the swarm, speeding up convergence for certain specific schemes. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 627–632, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23248
A transformer‐coupled LC‐tank injection locked frequency divider
Authors: Jang S.‐L. , Chen Fei‐Hung , Huang Jhin‐Fang
Published: January 2008

This article designs an injection locked frequency divider (ILFD) based on the direct injection technique and transformer‐coupled VCO topology. At the supply voltage of 3.3 V, the tuning range of the free‐running ILFD is from 2.47 to 2.32 GHz, about 150 MHz, and the locking range of the ILFD is from 4.58 to 5.09 GHz, about 510 MHz at the injection signal power of 0 dBm. The ILFD dissipates 188 mW at 3.3 V supply voltage and was fabricated in the TSMC 0.35 μm CMOS 2P4M CMOS technology. At the tuning voltage of 2.5 V, the measured phase noise of free‐running ILFD is about −116.7 dBc/Hz at 1 MHz offset frequency from 2.4 GHz, and the phase noise of the locked ILFD is about −128.6 dBc/Hz, while the input signal is with a power of −4 dBm. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 592–595, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23150
Vector sequence accelerator for solving problems in computational electromagnetics using the method of moments
Authors: Singh Surendra , Ritu Singh
Published: January 2008

The solution of an integral equation using the method of moments leads to a system of linear equations. The resulting system of equations can be solved by direct and iterative methods. This paper introduces an iterative method utilizing Brezinski's θ algorithm. The algorithm has previously been used in accelerating the convergence of a scalar sequence. With the aid of two integral equations, it is shown that the algorithm is able to accelerate the convergence of a vector sequence resulting in the solution vector. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 589–592, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23155
Slot antenna for ultra‐wideband communications
Authors: Huang Chih‐Yu , Tsai Chia‐Chou , Kuo Jieh‐Sen
Published: January 2008

A novel compact slot antenna has been proposed for ultra‐wideband (UWB) communications. The keyhole‐shaped slot antenna consists of an indented circular‐pie slot and a rectangular slot. The UWB (3.1–10.6 GHz) property is achieved by choosing suitable cutting pie and rectangular slot. Details of the proposed antenna design and measured results are presented and discussed. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 616–617, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23159
A novel miniaturized hybrid ring using complementary split ring resonators
Authors: Niu Jia‐Xiao , Zhou Xi‐Lang
Published: January 2008

In this article, a novel miniaturized hybrid ring operating at 2 GHz is presented. By replacing the 270° branch line of conventional hybrid ring by −90° left‐handed branch line realized by complementary split ring resonators (CSRRs), the occupied area of our proposed hybrid ring can be reduced by 60% from that of the conventional one. The performances are demonstrated by simulated and measured results, which are in good agreement. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 632–635, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23170
Novel ballast resistor network for power amplifier design
Authors: Gao Huai , Wang Rong , Xue Hongxi , Li G. P.
Published: January 2008

A novel ballast resistor network is proposed to achieve a better thermal management in HBT power cells without degrading the RF performances. Experiments were conducted on two HBT power amplifiers. They occupy same area. One is designed using conventional ballast network. The other uses proposed novel network. Temperature comparisons were made based on the same current density. Infrared camera images show that a more uniform temperature distribution is obtained in novel ballast network power amplifier. Our results demonstrate that the proposed novel ballast network has promising applications in high power amplifiers. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 711–713, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23174
Design and development of inclined and V‐slot microstrip antennas for circular polarization and omni‐directional radiation pattern
Authors: Satnoor S. K. , Vani R. M. , Konda R. B. , Mulgi S. N. , Hunagund P. V.
Published: January 2008

A low profile omni‐directional and circularly polarized one pair inclined slot microstrip antenna (ISMSA) and V‐slot microstrip antenna (VSMSA) are proposed. The one pair ISMSA gives left‐hand circular polarization (LHCP), right‐hand circular polarization (RHCP), and nearly omni‐directional radiation pattern. However, by modifying the inclined slots of ISMSA in the form of V, the antenna gives improved omni‐directional radiation pattern with LHCP and RHCP. The design concept of these antennas is given and the experimental results are discussed. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 708–711, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23177
Linearity‐optimized GaN HEMT Doherty amplifiers using derivative superposition technique for WCDMA applications
Authors: Lee Yong‐Sub , Lee Mun‐Woo , Jeong Yoon‐Ha
Published: January 2008

Gallium nitride (GaN) high‐electron mobility transistor (HEMT) Doherty amplifiers with the optimized linearity for wide‐band code division multiple access (WCDMA) applications are represented. At a 7‐dB back‐off output power, the measured single‐carrier WCDMA results show two‐way and three‐way GaN HEMT Doherty amplifiers with an adjacent channel leakage ratio (ACLR) of −43.2 and −48.2 dBc at ±2.5 MHz offset frequency with a drain efficiency of 43.1% and 30.9%, respectively. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 701–705, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23181
Design of ultra‐wideband bandpass filter using step‐impedance four‐mode resonator and aperture‐enhanced coupled structure
Authors: Cai Peng
Published: January 2008

A novel ultra‐wideband (UWB) bandpass filter (BPF) is proposed and implemented by using a four‐mode resonator, which has four resonant frequencies within the passband of the filter. By enhancing the coupling between the resonator and the input/output feed lines, an UWB BPF with six transmission poles is realized, although only one resonator is utilized. To alleviate the requirement on fabrication precision, aperture‐enhanced coupled lines are introduced to replace the parallel‐coupled lines in the filter. The fabricated filter exhibits good performances and the measured results show good agreement with the simulated results. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 696–699, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23184
A dual directional coupler with unique asymmetric coupling values at 1.7–2 GHz
Authors: Jung Jin‐Woo , Roh Hyoung‐Hwan , Park Jun‐Seok
Published: January 2008

Radio characteristic evaluations of each component through the entire communication system can be performed by using the signal sampling methods, which give information of the precise statistics and high qualified specifications. Particular modern trends on electrical devices demand extremely miniaturized dimensions to meet the hand‐held system units, such as personal communication services, mobile RFID applications and other possible products including crucial factors of low‐profile and mobility. It is eventually aimed to avoid unnecessary waste of manufacturing products, and guarantee the mobility, ease of use and so forth. Thus the multi‐mode electrical devices providing numerical advances in a single structure are needed and this is the motivation of further experiments. In this study, we propose a novel dual directional coupler design schemes including derivative calculations and its completely manufactured prototype. It has been designed by promoting three parallel coupled transmission lines with novel mathematic formula and auxiliary simulation systems. Outstanding technical features can be high isolation and directivity characteristics and these will be illustrated within the statistical tables and graphics for verification. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 775–780, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23188
Design of a novel ultra‐wide stopband lowpass filter using H‐defected ground structure
Authors: Boutejdar A. , Elsherbini A. , Omar A.
Published: January 2008

A novel compact wideband high‐rejection LPF using H‐shaped defected ground structure (DGS) elements is presented. The performance of the new H‐DGS was analyzed together with its effect on the filter performance. A wide rejection band and steep transition region was obtained. The filter was fabricated and the measurement and simulation results showed good agreement. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 771–775, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23189
Internal hybrid loop/monopole slot antenna for quad‐band operation in the mobile phone
Authors: Wu Chih‐Hsien , Wong Kin‐Lu
Published: January 2008

A novel printed hybrid loop/monopole slot antenna for quad‐band operation in the mobile phone is presented. The proposed hybrid antenna is composed of a meandered loop antenna and a monopole slot antenna, and can generate two wide operating bands centered at about 900 and 1900 MHz to cover GSM850/900/DCS/PCS operation. The hybrid antenna is easily fabricated by bending the meandered loop antenna at low cost, which is connected to and centered at the top edge of the system ground plane where a straight monopole slot is embedded. With quad‐band operation obtained, the hybrid antenna, however, occupies a small volume of 5.5 × 6 × 60 mm3 or 1.98 cm3 only inside the mobile phone. A 50‐Ω microstrip feedline is used to excite the meandered loop antenna and the monopole slot antenna in series. Detailed results and parametric studies of the proposed hybrid antenna are presented. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 795–801, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23201
A band‐notched swallow‐tailed planar monopole antenna for UWB application
Authors: Zhou Haijin , Liu Qizhong , Sun Baohua , Yang Yanjiong
Published: January 2008

In this article, we propose a swallow‐tailed UWB planar monopole antenna that exhibits a notch characteristic in the 5‐GHz WLAN band (5.15–5.825 GHz) by inserting a hat‐shaped slot into the antenna. The effects of the length of the slot on the notched frequency band are analyzed. The radiation patterns of the proposed antenna are also measured and the gains are shown to be flat, except in the notched frequency band. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 793–795, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23202
Stoer‐Bulirsch adaptive frequency sampling method for efficient analysis of frequency selective surfaces
Authors: Chen J. Q. , Chen R. S. , Liu Z. W.
Published: January 2008

In this article, a Stoer‐Bulirsch adaptive frequency sampling method is proposed in conjunction with the method of moments to analyze the broadband electromagnetic wave scattering from frequency selective surfaces. On comparing with other sampling methods, the Stoer‐Bulirsch algorithm is a recursive tabular method and requires no matrix inversion. Therefore, it can obtain a rational interpolation function without suffering from singularity problems. Furthermore, since final results are obtained by interpolating with the adaptive frequency sampling method, no more information is needed except the sampled frequency and its true value. Hence, it can be widely used in most of the electromagnetic simulations. Numerical results show that our proposed sampling strategy performs well in terms of both simulation time and computation accuracy. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 755–758, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23204
Adaptive sampling cubic‐spline interpolation method for efficient calculation of monostatic RCS
Authors: Liu Z. W. , Chen R. S. , Chen J. Q.
Published: January 2008

An adaptive strategy is combined with the cubic‐spline interpolation method in this article to efficiently calculate the scattering from electrically large objects. The cubic‐spline interpolation method is used to approximate the monostatic radar crosssection (RCS) curve on a set of nonuniform sampling nodes and the adaptive strategy is employed to generate new sampling points automatically. Unlike asymptotic waveform evaluation method, the derivatives are not required for the novel interpolation method. Numerical results demonstrate that the proposed method is able to rigorously approximate the result with less computation time when compared with conventional interpolation methods. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 751–755, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23211
Frequency and pattern reconfigurable Yagi patch antenna
Authors: Yang Xue‐Song , Wang Bing‐Zhong , Xiao Shaoqiu , Fung Man Kim
Published: January 2008

This work describes the use of switched slits and slots to reconfigure the operating frequency and the radiation pattern of a Yagi patch antenna. The Yagi patch antenna is fabricated on the top side of a grounded substrate and is fed by a coaxial probe. By using switches to reconfigure the silts etched on the driven patch, the antenna can operate at two frequencies of 8.175 and 9.31 GHz. By changing the states of the slots etched on different parasitic element patches, directions of the radiation pattern can be changed. Thus, a design that is reconfigurable in both frequency and radiation pattern is accomplished. As a proof of concept, five models are fabricated and tested. Three of them operate at the higher frequency and two of them at the lower one. The main beams of these models point to different directions in the E‐plane. Simulated and measured results are given and they are in good agreement. The antenna can be used in radar, satellite communications, etc. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 716–719, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23214
GPS antenna design with slotted ground plane
Authors: Sim Chow‐Yen‐Desmond , Han Tuan‐Yung
Published: January 2008

A single layer, single‐feed circularly polarized (CP) microstrip antenna designed with 2 pairs of slot embedded on its ground plane for global positioning system (GPS) is proposed. The experimental results shown that by simply tuning the length of the slotted pair, two orthogonal near‐degenerate resonant modes for CP radiation can be excited. By comparing the proposed antenna to a reference antenna of similar sizes with two pairs of slit embedded on the radiating square patch; the proposed antenna demonstrated enhancement in gain, bandwidth, and radiation efficiency. Furthermore, in comparison to other CP antennas with slotted ground plane design, it demonstrated an excellent F/B ratio and wide 3 dB beamwidth. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 818–821, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23215
Optical current sensor based on metal coated Hi‐Bi fiber loop mirror
Authors: Marques B. V. , Frazão O. , Mendonça S. , Perez J. , Marques M. B. , Santos S. F. , Baptista J. M.
Published: January 2008

An optical current sensor based on a metal coated Hi‐Bi fiber loop mirror is reported. This current sensor quantifies the current through the measurement of the temperature which varies accordingly with the magnitude of the electrical current. The temperature change is analyzed through the variation of the wavelength shift of a fringe minimum of a Hi‐Bi fiber loop mirror. The minimum current detection was found to be approximately 10 A. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 780–782, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23217
Surface and proper leaky‐modes in a lossless grounded pseudochiral omega slab
Authors: Matos Sérgio A. , Paiva Carlos R. , Barbosa Afonso M.
Published: January 2008

Surface and proper leaky modes guided by a grounded pseudochiral omega slab are studied. A new physical result is found: proper leaky modes may occur in a lossless grounded pseudochiral omega slab even when all medium parameters are positive. A correlation between polaritons at interfaces and leaky modes in slab waveguides is established. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 814–818, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23220