bluuebunny/crossref_metadata_2025 huggingface dataset:
Damage and degenerative changes in menisci‐covered and exposed tibial osteochondral regions after simulated landing impact compression—a porcine study
Authors: Yeow Chen Hua , Lau Swee Ting , Lee Peter Vee Sin , Goh James Cho Hong
Published: February 2009

The capacity of menisci‐covered and exposed tibial osteochondral regions in resisting impact‐induced damage and degeneration is not fully understood. This study sought to evaluate damage and degenerative changes in these regions upon a single simulated landing impact. We hypothesized that the menisci‐covered regions are more susceptible to damage and degeneration than their exposed counterparts. Menisci‐covered and exposed tibial osteochondral explants were extracted from fresh porcine hind legs and placed in culture up to 14 days. Impact compression, based on a single 10‐Hz haversine, was performed at Day 1. Control (non‐impact) and impacted explants were randomly selected for cell viability assessment, glycoaminoglycan and collagen content assays, histology, immunohistochemistry, and micro‐computed tomography. When subjected to 2‐mm displacement compression, exposed explants achieved a significantly higher peak impact stress (p < 0.05) than menisci‐covered explants. No significant difference in cell viability, glycoaminoglycan and collagen content, and Mankin scores (p > 0.05) was observed between both explant groups. Both groups were observed with reduced proteoglycan and type II collagen staining at Day 14; the exposed group was noted with increased cartilage volume at Days 7–14. The inferior resistance of menisci‐covered regions, against impact‐induced damage and degeneration, is a potential factor that may contribute to the meniscectomy model of osteoarthritis. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27: 1100–1108, 2009
Clay dispersion and its relation to surface charge in a paddy soil of the Red River Delta, Vietnam
Authors: Nguyen Minh N. , Dultz Stefan , Kasbohm Jörn , Le Duc
Published: February 2009

Dispersion is an important issue for clay leaching in soils. In paddy soils of the Red River Delta (RRD), flooding with fresh water and relatively high leaching rates can accelerate dispersion and the translocation of clay. For the clay fraction of the puddled horizon of a typical paddy soil of the RRD, the effect of various cations and anions as well as humic acid (HA) at different pH values on the surface charge (SC) were quantified and the dispersion properties were determined in test tubes and described by the C50 value.

In the <2 µm fraction, dominated by illite, the proportion of 2:1 vs. 1:1 clay minerals is 5:1. The organic‐C content of the clay fraction is 2.2%. Surface charge was found to be highly pH‐dependent. At pH 8 values of –32 and at pH 1 of –8 mmolc kg–1 were obtained. Complete dispersion was observed at pH > 4, where SC is > –18 mmolc kg–1. The flocculation efficiency of Ca strongly depends on the pH. At pH 4, the C50 value is 0.33, 0.66 at pH 5, and 0.90 mmol L–1 at pH 6. At pH 6, close to realistic conditions of paddy soils, the effect of divalent cations on the SC and flocculation decreases in the order: Pb > Cu > Cd > FeII > Zn > Ca > MnII > Mg; FeII was found to have a slightly stronger effect on flocculation than Ca. An increase in concentrations of Ca, MnII, and Mg from 0 to 1 mmol L–1 resulted in a change in SC from –25 to approx. –15 mmolc kg–1. In comparison, the divalent heavy‐metal cations Pb, Cu, Cd, and Zn were found to neutralize the SC more effectively. At a Pb concentration of 1 mmol L–1, the SC is –2 mmolc kg–1. From pH 3 to 5, the dispersion of the clay fraction is facilitated rather by SO$ _4^{2-} $ than by Cl–, which can be explained by the higher affinity of SO$ _4^{2-} $ to the positively charged sites. With an increase of the amount of HA added, the SC continuously shifts to more negative values, and higher concentrations of cations are needed for flocculation. At pH 3, where flocculation is usually observed, the presence of HA at a concentration of 40 mg L–1 resulted in a dispersion of the clay fraction. While high anion concentrations and the presence of HA counteract flocculation by making the SC more negative, FeII and Ca (C50 at pH 6 = 0.8 and 0.9 mmol L–1, respectively) are the main factors for the flocculation of the clay fraction.

For FeII and Ca, the most common cations in soil solution, the C50 values were found to be relatively close together at pH 4, 5, and 6, respectively. Depending on the specific mineralogical composition of the clay fraction, SC is a suitable measure for the determination of dispersion properties and for the development of methods to keep clay particles in the soil in the flocculated state.
The influence of a Gene expression profile on breast cancer decisions
Authors: Henry Leonard R. , Stojadinovic Alexander , Swain Sandra M. , Prindiville Sheila , Cordes Rose , Soballe Peter W.
Published: February 2009

Purpose

The Oncotype Dx® Recurrence Score (RS), is often employed in patients with estrogen receptor‐positive, node negative (ER+LN−) breast cancer. We investigated the impact of the RS on actual chemotherapy administration and the effect of the assay on a panel of breast oncology experts.

Patients and Methods

The prospective adjuvant chemotherapy recommendations (prior to RS) and actual adjuvant therapy (after RS) for consecutive patients with ER+LN− breast cancer were recorded. After 6 months and with the same information, a panel of five experts made adjuvant therapy recommendations with and without RS and rated the strength of their recommendations. Rates of panel consensus, recommendation changes, and changes in recommendation strength were compared.

Results

There were 29 patients (28 women). RS results altered the plan for chemotherapy in 9 patients (31%); 7 of 13 patients (54%) initially recommended for chemotherapy did not receive it, and 2 of 16 (13%) received chemotherapy following initial recommendations against it. RS results changed the panel's chemotherapy recommendation in 7 patients (24%): 5 of 12 (42%) recommendations for changed to against, and 2 of 17 (12%) recommendations against changed to for chemotherapy. RS increased consensus by the panel 10%, but did not increase the reported strength in chemotherapy recommendations.

Conclusions

RS results were associated with real‐world decision changes in 31% of patients and 24% of panel recommendations and increased panel consensus by 10%. However RS did not increase the strength of panelist's recommendations. J. Surg. Oncol. 2009;99:319–323. Published 2009 Wiley Periodicals, Inc.
Circulating form of human vascular adhesion protein‐1 (VAP‐1): Decreased serum levels in progression of colorectal cancer and predictive marker of lymphatic and hepatic metastasis
Authors: Toiyama Yuji , Miki Chikao , Inoue Yasuhiro , Kawamoto Aya , Kusunoki Masato
Published: February 2009

Background and Objectives

Vascular adhesion protein‐1 (VAP‐1) is an endothelial cell molecule that controls leukocyte tissue infiltration. Elevated serum soluble VAP‐1 (sVAP‐1) has been described in certain diseases with an inflammatory component. However, sVAP‐1 expression or function has not been studied in colorectal cancer. The present study determined the relationships between preoperative serum sVAP‐1 and clinicopathological features and prognosis in colorectal cancer.

Methods

One hundred patients with histologically proven colorectal cancer and 33 normal volunteers were included. Preoperative serum was collected, and sVAP‐1 levels were assayed by enzyme‐linked immunosorbent assay.

Results

Mean sVAP‐1 level in patients was significantly higher than in controls, and decreased with disease progression. Mean sVAP‐1 level was significantly correlated with venous invasion, lymph node metastasis, distant metastasis including hepatic metastasis, and advanced TNM classification. Furthermore, sVAP‐1 was an independent marker for predicting lymph node or hepatic metastasis. Prognosis of patients with a lower sVAP‐1 level was significantly worse than those with elevated sVAP‐1.

Conclusions

Preoperative low sVAP‐1 level is associated with poor prognosis in colorectal cancer. Measuring serum sVAP‐1 may provide valuable information in predicting patients with lymph node or hepatic metastasis. J. Surg. Oncol. 2009;99:368–372. © 2009 Wiley‐Liss, Inc.
Microsatellite DNA instability in nasal polyposis
Authors: Karatzanis Alexander D. , Tzortzaki Eleni , Samara Katerina D. , Neofytou Eirini , Zenk Johannes , Iro Heinrich , Siafakas Nikolaos , Velegrakis George A.
Published: February 2009

Objective:

Genetic alterations, such as microsatellite instability (MSI) and loss of heterozygosity (LOH), have been detected in various inflammatory diseases, providing evidence that acquired somatic mutations might play a role in the aetiopathogenesis of chronic inflammatory conditions. The aim of this study is to assess the presence of MSI and/or LOH in nasal cytology of patients with nasal polyps.

Study Design:

Prospective case‐controlled basic science experiment utilizing human blood and human nasal brush samples.

Methods:

Nasal brush samples and peripheral blood from 12 patients with nasal polyps were analyzed. DNA was extracted and analyzed for MSI and LOH using the following microsatellite markers: D2S2113, D6S344, D6S1002, D11S1253, D11S480, USAT24G1, and D13S273, harboring potential susceptibility genes for nasal polyposis. Microsatellite DNA analysis was also performed in 7 control subjects.

Results:

MSI or LOH were revealed in 3 specimens of the nasal polyps group. Among these there were 2 cases of LOH, one for marker D11S1273 and one for D13S273, and one case of MSI in marker USAT24G1. Each one of these alterations was detected in a different patient. None of the control subjects exhibited any genetic alterations in the 7 markers tested.

Conclusions:

This is the first time that microsatellite genetic alterations are reported in nasal disease. The presence of such alterations suggests that acquired genomic somatic mutations might play a role in the pathogenesis of nasal polyps. Laryngoscope, 2009
Identification of distant metastases with PET‐CT in patients with suspected recurrent head and neck cancer
Authors: Gourin Christine G. , Watts Tammara , Williams Hadyn T. , Patel Vijay S. , Bilodeau Paul A. , Coleman Teresa A.
Published: February 2009

Objectives:

To investigate the utility of positron‐emission tomography/computed tomography (PET‐CT) in identifying distant metastatic disease in patients with suspected recurrent head and neck squamous cell cancer (HNSCC).

Study Design:

Retrospective analysis.

Methods:

Retrospective analysis of 64 consecutive patients with suspected recurrent HNSCC following definitive treatment who underwent PET‐CT imaging were eligible for inclusion. Patients with previous known distant metastatic disease were excluded.

Results:

The majority of patients (81%) had TNM stage III or IV disease. PET‐CT was suspicious for pulmonary malignancy in 14 patients (22%) and indeterminate in 6 patients (9%). Pulmonary metastases or a new lung primary were present in 10 patients (16%): 7 of 14 patients with positive PET‐CT scans (50%) and 3 of 50 patients with negative or indeterminate PET‐CT scans (6%). Including nonpulmonary sites, the overall incidence of distant disease was 23% (15/64) with 20% (13/64) unsuspected prior to PET‐CT. The sensitivity and specificity of PET‐CT in predicting distant malignancy was 86% and 84%, respectively, with a positive predictive value of 60% and a negative predictive value of 95%. There was a significant correlation between standardized uptake value (SUV) on PET‐CT and positive histology, with a mean SUV of 8.5 (range, 4.7–16.2) in patients with distant metastases compared with a mean SUV of 2.9 (range, 1.9–4.2) in patients with benign pathology (r = 0.87, P < .0001).

Conclusions:

A significant number of patients with recurrent HNSCC have distant metastases at the time of recurrence. These data suggest that PET‐CT improves detection of metastatic disease in the high‐risk patient and should be performed as part of the routine evaluation of patients with suspected recurrence prior to salvage surgery. Laryngoscope, 2009
Voice handicap evaluation after supracricoid partial laryngectomy
Authors: Makeieff Marc , de la Breteque Amy , Guerrier B. , Giovanni A.
Published: February 2009

Objectives:

To gather information on the vocal and professional impact of supracricoid partial laryngectomy (SCPL).

Study Design:

Collection of quality of life data more than 12 months postsurgery, including expert‐rated patient voice assessment (GRBAS [grade, roughness, breathiness, asthenia, strain] scale), self voice assessment, Voice Handicap Index (VHI), and socioprofessional data.

Patients:

Sixty‐four patients were evaluated after SCPL. The surgical procedure had been conducted for initial stage T1b or T2 glottic carcinoma. All patients had no recurrence, were decanulated, and did not have any swallowing impairment. Thirty‐three patients were less than 60 years old and were professionally active at the time of surgery. The mean age was 48.5 years old (42–59 years old). Fifteen patients were working in the communications sector, so use of their voice was obligatory. Professional impact and VHI measurements were evaluated.

Results:

For patients with professional activities before surgery, 15/33 (45%) continued their activities, whereas 55% had to withdraw from or modify these activities. For patients with communications activities, 6/15 (40%) continued their activities, 4 (26.6%) adapted, and 5 (33.3%) withdrew from their professional activities. The mean VHI value was 51.2. The mean VHI values according to the dysphonic grade (1, 2, and 3) were 36.3, 50.7, and 52.9, respectively. The mean VHI values were 45.6, 58.6, and 53.2, respectively, for patients who pursued their professional activities, withdrew from or adapted their activities, and had no professional activities. Correlations were obtained between VHI and the dysphonic grade (P = .043), cessation of professional activities (P = .034), and the time elapsed since surgery (P = .046). VHI emotional and physical subscale scores were significantly higher for patients who had withdrawn from their professional activities or adapted them.

Conclusions:

Supracricoid partial laryngectomy can have a marked social and professional impact. Many patients have to withdraw from professional activities in which vocal involvement is essential. The potential postsurgical social voice impact should be taken into consideration before proposing this surgery, and it is essential to estimate the possible impacts of the vocal handicap according to the patient's professional or other activities. Laryngoscope, 2009
Salivary gland functional recovery after sialendoscopy
Authors: Su Yu‐Xiong , Xu Jie‐Hua , Liao Gui‐Qing , Zheng Guang‐Sen , Cheng Mu‐Hua , Han Lu , Shan Hong
Published: February 2009

Objectives/Hypothesis:

To date, there has been no report on the salivary gland functional outcomes after sialendoscopic surgery. The purpose of this study is to evaluate salivary gland functional recovery after sialendoscopic management of obstructive salivary gland disease.

Study Design:

A prospective, self‐control study.

Methods:

The present study was undertaken among patients scheduled for sialendoscopic surgery with unilateral salivary ductal obstructions. Glandular function was quantitatively assessed with the use of sialometry and scintigraphy preoperatively and at least 3 months postoperatively.

Results:

A consecutive series of 17 patients were followed for 14 ± 8 months. Sialendoscopic procedures included removal of calculi in 15 cases and dilatation of stenosis in two cases. All patients were free of symptoms during follow‐up. Before surgery, there was a significant decline in the resting and stimulated saliva flow rate, uptake index, and excretion fraction of the obstructive glands compared with the contralateral normal glands. Postoperatively, although the degrees of functional recovery varied in individuals, statistical analysis revealed that the glandular function increased significantly in the affected glands and had no differences when compared to the contralateral glands.

Conclusions:

These data provide a unique functional assessment after sialendoscopic surgery. Our results demonstrate that sialendoscopy is an organ‐preserving surgical approach which can achieve satisfactory functional recovery in the management of salivary ductal obstructions. Laryngoscope, 2009
Using proton nuclear magnetic resonance as a rapid response research tool for methyl ester characterization in biodiesel
Authors: ter Horst Marc , Urbin Stephanie , Burton Rachel , McMillan Christina
Published: February 2009

Reliable and rapid analysis remains a high priority for quality control in biodiesel production. Quantifying biodiesel with alternative analytical tools such as proton nuclear magnetic resonance (1H NMR) can provide total methyl esters distributions without significant sample pretreatment. Using unique spectra of individual methyl esters, we investigate the feasibility of using 1H NMR spectroscopy to identify and quantify relative and absolute concentrations of methyl esters in a biodiesel.
Development of a calculation procedure for the statistical interpretation of the results of potential mapping performed on reinforced concrete structures
Authors: Gulikers J. , Elsener B.
Published: February 2009

Potential mapping is a widely applied and accepted non‐destructive measuring technique to assess the condition of concrete structures with respect to corrosion of the embedded reinforcement steel. Most often a single reference electrode is used to perform point measurements according to a predefined grid. At present there is much debate on the appropriate potential level to allow for a distinction between passive and actively corroding steel. In the RILEM recommendation for half‐cell potential measurements, a statistical analysis of the results of potential mapping is advocated in order to arrive at an improved quantification of this potential region pertaining to the structure under investigation. However, the underlying calculation procedure has not been elaborated and consequently there is no practical and unambiguous guidance for the consulting engineer on how to perform such a statistical analysis.

In this paper, the theory for the statistical analysis is presented based on the assumption that the potential distribution for both actively corroding and passive steel can be adequately described by a normal probability density distribution. This theory is applied to a number of situations to exemplify the procedure by clear graphs. The potential criteria derived will demonstrate a significantly smaller range as compared to the criteria presented in ASTM C 876. Moreover, with this statistical analysis any desired probability level of detection of corroding reinforcement steel can be chosen.
Satisfaction in choice as a function of the number of alternatives: When “goods satiate”
Authors: Reutskaja Elena , Hogarth Robin M.
Published: February 2009

People are typically thought to be better off with more choices, yet often prefer to choose from few alternatives. By considering the perceived benefits and costs of choice, it is proposed that satisfaction from choice is an inverted U‐shaped function of the number of alternatives. This proposition is verified experimentally. It is further hypothesized that differences in cognitive costs affect the relative location of the function's peak. Specifically, since—in large sets—perceptual costs of processing alternatives varying in shape are greater than for alternatives varying in color, the peak of the satisfaction function for the latter will lie to the right of the former. This prediction is also validated. The paper emphasizes the need for an explicit rationale for knowing how much choice is “enough.” © 2009 Wiley Periodicals, Inc.
Testing the boundaries of the choice overload phenomenon: The effect of number of options and time pressure on decision difficulty and satisfaction
Authors: Haynes Graeme A.
Published: February 2009

The number of alternatives available to people in many day‐to‐day decisions has greatly increased in Western societies. The present research sought to build upon recent research suggesting that having large numbers of alternatives can sometimes have negative consequences for individuals. In the present experiment, participants were presented with descriptions of either 3 or 10 prizes and asked to choose one, for which they were to be entered in a drawing. The number of alternatives was manipulated in conjunction with the amount of time people were allotted to make a decision (limited vs. extended decision time). Following their decisions, participants completed measures of decision‐related difficulty, task enjoyment, satisfaction, and regret. Participants given a limited amount of time to choose with a larger set of alternatives found their decisions to be more difficult and frustrating than did participants in the other conditions. The larger set of alternatives led to less satisfaction, but not less regret, with people's decisions. Implications for research on the choice overload phenomenon are discussed. © 2009 Wiley Periodicals, Inc.
Inhibition of autotaxin production or activity blocks lysophosphatidylcholine‐induced migration of human breast cancer and melanoma cells
Authors: Gaetano Cristoforo G. , Samadi Nasser , Tomsig Jose L. , Macdonald Timothy L. , Lynch Kevin R. , Brindley David N.
Published: February 2009

Increased expression of autotaxin in tumors including glioblastoma, breast, renal, ovarian, lung, and thyroid cancers is associated with increased tumor aggressiveness. Autotaxin promotes metastasis as well as cell growth, survival, and migration of cancer cells. These actions could depend on the noncatalytic effects of autotaxin on cell adhesion, or the catalytic activity of autotaxin, which converts lysophosphatidylcholine into lysophosphatidate in the extracellular fluid surrounding the tumor. Both lysophosphatidylcholine (LPC) and lysophosphatidate have been reported to stimulate migration through their respective G‐protein coupled receptors. The present study determines the roles of autotaxin, LPC, and lysophosphatidate in controlling the migration of two cancer cell lines: MDA‐MB‐231 breast cancer cells, which produce little autotaxin and MDA‐MB‐435 melanoma cells that secrete significant levels of autotaxin. LPC alone was unable to stimulate the migration of either cell type unless autotaxin was present. Knocking down autotaxin secretion, or inhibiting its catalytic activity, blocked cell migration by preventing lysophosphatidate production and the subsequent activation of LPA1/3 receptors. We conclude that inhibiting autotaxin production or activity could provide a beneficial adjuvant to chemotherapy for preventing tumor growth and metastasis in patients with high autotaxin expression in their tumors. © 2009 Wiley‐Liss, Inc.
Merging with a buyer group member
Authors: Erutku Can , de Lamirande Patrick
Published: February 2009

We examine a merger between a national retailer and a local retailer who is a member of a buyer group. While the traditional literature on mergers assumes an oligopolistic industry (where the merger takes place) supplied by a perfectly competitive one, we assume here that retailers obtain their input from a supplier that can offer quantity discounts. In this setting, a merger can be profitable for insiders (solving the merger paradox) and can also be more profitable for insiders than for outsiders (solving the free‐riding problem). This result holds even if the merged firm ends‐up with a small share of the market. However, welfare decreases post‐merger. Copyright © 2009 John Wiley & Sons, Ltd.
Clinical characteristics of 49 patients with psychogenic movement disorders in a tertiary clinic in Turkey
Authors: Ertan Sibel , Uluduz Derya , Özekmekçi Sibel , Kiziltan Günes , Ertan Turan , Yalçinkaya Cengiz , Özkara Çigdem
Published: February 2009

Patients admitted to movement disorders outpatient unit at a university hospital between January 2002 and June 2007 were screened for psychogenic movement disorders (PMDs). Out of 1,743 patients, 49 patients (2.8%), including four children, were diagnosed to have PMDs. Women to men ratio was 34/15. The mean age and the age‐at‐onset were 41 ± 17 years and 36 ± 15 years in the adult group, and 10 ± 2 and 9 ± 2 years in children. Among the whole group, 44% had tremor, 24% dystonia, 12% pure gait disorders, 8% parkinsonism, 6% chorea‐ballism, and 4% tic disorder. PMD developed acutely in 85% of patients, and distractibility was observed in 83%. Of the patients, 81% met the criteria for clinically established PMD, whereas 16% for documented and 2% for probable PMD. Although our data was obtained from a different culture, our results showed that hospital‐based frequency and phenomenological features between our PMD group and previously reported ones are similar. © 2009 Movement Disorder Society
Familial Parkinsonism and early onset Parkinson's disease in a Brazilian movement disorders clinic: Phenotypic characterization and frequency of SNCA, PRKN, PINK1, and LRRK2 mutations
Authors: Camargos Sarah Teixeira , Dornas Leonardo Oliveira , Momeni Parastoo , Lees Andrew , Hardy John , Singleton Andrew , Cardoso Francisco
Published: February 2009

The aim of the study was to evaluate the frequency and to perform phenotypic and genotypic characterization of familial Parkinsonism and early onset Parkinson's disease (EOPD) in a Brazilian movement disorder unit. We performed a standardized clinical assessment of patients followed by sequencing of PRKN, PINK1 in EOPD cases and SNCA, LRRK2 in familial Parkinsonism individuals. During the period of study (January through December, 2006), we examined 575 consecutive patients of whom 226 (39.3%) met the diagnosis of Parkinsonism and idiopathic Parkinson's disease (IPD) was diagnosed in 202 of the latter. Of the IPD cases, 45 (22.3%) had EOPD. The age at onset in the EOPD cases (n = 45) was 34.8 ± 5.4 years (mean ± standard deviation). The age at onset in the familial late‐onset PD patients (n = 8) was 52.3 ± 12.2 years. In the early onset cases, we identified five known mutations in PRKN, two single heterozygous and three compound heterozygous (P153R, T240M, 255Adel, W54R, V3I); in addition, we identified one novel mutation in PINK1 (homozygous deletion of exon 7). In the familial cases (late onset), 1 patient had a novel LRRK2 variant, Q923H, but no SNCA mutations were identified. We have demonstrated that EOPD accounts for a high frequency of IPD cases in our tertiary referral center. PRKN was the most commonly mutated gene, but we also identified a novel mutation in PINK1 and a novel variant in LRRK2. © 2009 Movement Disorder Society
Long lead time flood warnings: reality or fantasy?
Authors: Golding B. W.
Published: February 2009

This paper reviews recent advances in weather forecasting capability in the United Kingdom and their implications for increasing the lead time with which flood warnings can be issued. The events of summer 2007 have highlighted the vulnerability of parts of the United Kingdom to flooding and the need for long lead time flood warnings to enable the protection of people and critical infrastructure. Historically, computer weather forecasting models have been unable to forecast at the scales of importance for flood warning, and so the warning processes have been forced to rely on measurements on the ground. Examples are presented to demonstrate that new forecasting technologies, currently being implemented, enable warnings to be produced much earlier, provided they are couched in probabilistic terms and interpreted appropriately. Crown Copyright © 2009. Reproduced with the permission of the Controller of HMSO. Published by John Wiley & Sons, Ltd
Release and characterization of single side chains of white cabbage pectin and their complement‐fixing activity
Authors: Westereng Bjorge , Coenen Gerd Jan , Michaelsen Terje Einar , Voragen Alphons G. J. , Samuelsen Anne Berit , Schols Henk A. , Knutsen Svein Halvor
Published: February 2009

A mixture of single side chains from white cabbage pectin were obtained by anion exchange chromatography after applying mild chemical conditions promoting β‐elimination. These pectin fragments were characterized by their molecular weight distribution, sugar composition, 13C‐NMR, and MALDI‐TOF‐MS analysis. These analyses revealed that the large oligosaccharides released by β‐eliminative treatment were composed of α‐1,5 linked arabinosyl residues with 2‐ and 3‐linked α‐arabinosyl side chains, and, or β‐1,4 linked galactosyl side chains. Fractions were tested for complement‐fixing activity in order to determine their interaction with the complement system. These results strongly indicated that there was a minimal unit size responsible for the complement‐fixing activity. Neutral pectin fragments (˜8 kDa) obtained from β‐elimination were inactive in the complement system, although they contained a sugar composition previously shown to be highly active. Larger pectin fragments (˜17 kDa) retained some activity, but much lower than polymers containing rhamnogalacturonan type 1 (RGI) structures isolated from the same source. This implied that structural elements containing multiple side chains is necessary for efficient complement‐fixing activity.
Three‐section symmetrical 3‐dB directional coupler in multilayer microstrip technology designed with the use of multi‐technique compensation
Authors: Wincza Krzysztof , Gruszczynski Slawomir
Published: February 2009

A broadband high‐performance three‐section symmetrical 3‐dB directional coupler designed in a microstrip multilayer technology has been presented for the first time. To achieve excellent properties of the directional coupler a novel approach has been applied in which three different compensation techniques have been simultaneously used. The designed directional coupler features excellent properties over two‐octave frequency band and can be easily applied in large microwave networks as a surface mount element. Both calculated and measured results are presented to confirm the validity of the described design technique. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 902–906, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24193
Miniaturization of narrow‐band power dividers by using CPW metamaterial transmission lines
Authors: Aznar Francisco , Bonache Jordi , Valcarcel Alexandre , Martín Ferran
Published: February 2009

In this article, it is demonstrated that the size of planar microwave circuits and components can be reduced by using coplanar waveguide (CPW) metamaterial transmission lines. The small size and the possibility to control the electrical characteristics (phase and characteristic impedance) of these lines, make them suitable for compact planar device design. To illustrate the possibilities of the approach, different power dividers, consisting on split‐ring resonators (SRRs) and spiral resonators (SRs) loaded CPWs, have been designed, fabricated (in a conventional low loss microwave substrate) and measured. Sixty percentage size reduction, as compared to conventional devices, has been achieved. This size reduction can be enhanced by using smaller resonators based on different topologies. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 926–929, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24195
A compact CPW‐Fed UWB BPF using combined microstrip SIR
Authors: Chen Yu‐Cheng , Lee Ching‐Her , Hsu Chung‐I. G.
Published: February 2009

This article presents a multimode‐resonator (MMR)‐based ultra‐wideband (UWB) bandpass filter (BPF) fed by modified coplanar waveguides (CPWs). The MMR employed in the UWB BPF is formed by combining two quarter‐wavelength (λ/4) microstrip stepped‐impedance resonators (SIRs) in a structure‐shared fashion. The first two resonant frequencies of the inherent λ/4 SIRs and the fundamental one of the embedded half‐wavelength (λ/2) resonator were designed and located inside the UWB passband. Experiments on a prototype UWB BPF were carried out for validating the filter design. The measured frequency responses show an insertion loss of less than 1 dB between the first and the last |S11| null frequencies in the UWB passband and an upper −20‐dB stopband bandwidth of about 6.14 GHz. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 918–921, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24199
An accurate evaluation of the nonsymmetrical components of Green's functions for multilayered media in the near‐field region
Authors: Abdelmageed Alaa K.
Published: February 2009

The discrete complex image method has proved to be one of the most efficient techniques to evaluate Green's functions for multilayered media, particularly in the near‐ and intermediate‐field regions. Although the extraction of surface waves extends its validity to the far field, it suffers from erroneous results that contaminate the computation of the near field. To handle this problem for the nonsymmetrical components of Greens functions, we follow the same approach adopted by the author and others for the symmetrical components where a number of artificial poles are extracted for each physical surface‐wave pole occurrence. This approach has proved its validity and yielded good results in all field regions. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 881–885, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24201
A compact three‐way dual‐frequency power divider
Authors: Wang Xinhuai , Chen Dongzhou , Shi Xiaowei , Wei Feng , Chen Xiaoqun
Published: February 2009

In this article, a compact three‐way dual‐frequency power divider is proposed. The circuit is composed of two sections of three transmission lines and four RLC networks. The RLC networks using planar lumped inductors, capacitors, and resistors can provide enough isolation and good amplitude balance simultaneously at two arbitrary frequencies. The structure of the power divider used to determine the design parameters has been given. To verify the validity, a proposed power divider was fabricated and measured at 915 MHz and 2450 MHz. The proposed power divider achieves physical size reduction of about 62% compared with the conventional one. Both theoretical and simulated results are presented, which are in good agreement with the measured results. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 913–915, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24203
Fractal monopole‐like antenna with series Hilbert‐curves for WLAN dual‐band and circular polarization applications
Authors: Bor Sheau‐Shong , Lu Tsung‐Che , Liu Ji‐Chyun , Zeng Bing‐Hao
Published: February 2009

A novel design of fractal monopole‐like antenna with series Hilbert‐curve configuration is proposed for 2.45/5.35 GHz dual‐band and circular polarization applications in this article. The compact fractal antenna consists of five series Hilbert‐curve and the monopole couplings, and exhibits the desired dual‐band 2.45 GHz (BW = 85 MHz, 3.45%) and 5.35 GHz (BW = 240 MHz, 4.46%), respectively, for IEEE 802.11a/b/g WLAN applications. The circular polarizations for dual‐band are demonstrated with AR spectrum and electric field intensities. Results included with frequency responses, radiation patterns, and electric field intensities are presented and discussed. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 876–880, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24204
Fiber‐based telecoms components at 1550 nm for the generation of cw‐THz by photomixing
Authors: Hindle Francis , Szriftgiser Pascal , Bacquet Denis , Yang Chun , Mouret Gael , Bocquet Robin
Published: February 2009

A standard DFB diode laser operating at 1.55 μm has been used with an EDFA to construct a hybrid cw‐THz spectrometer. Frequency steps of as small as 4 MHz are demonstrated by current control whereas larger spectra in excess of 400 GHz have been realized using temperature control. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 991–994, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24207
Compact tri‐band BPF design using spur‐line‐loaded tri‐section SIRs
Authors: Lee Ching‐Her , Hsu Chung‐I G. , Chen Yu‐Cheng
Published: February 2009

In this article, a new tri‐band microstrip bandpass filter (BPF) is proposed. The BPF is composed of two folded, rectangular‐shaped three‐section SIRs (TSSIRs) whose first three resonant frequencies can be tuned to locate in the desired passbands. The BPF are 0° fed and the end sections of the TSSIRs are designed in an antiparallel fashion to produce zeros at appropriate frequencies for improving passband selectivity. In addition, by embedding spur lines and defected ground structures (DGS) in the BPF, extra transmission zeros around the first spurious passband are introduced to widen the upper stopband. The designed BPF is fabricated on an RT/Duroid 6010 substrate. The measured fractional bandwidths (minimum insertion losses) for the 1.57 GHz (GPS), 2.45 GHz (ISM), and 3.5 GHz (WiMAX) bands, respectively, are 11.5% (1 dB), 4.6% (2.19 dB), and 10.9% (1.3 dB), which agree well with those predicted by simulation. It also shows that for miniaturization purposes, the TSSIRs are made meandered to give an overall circuit size of only 23.29 × 10.94 mm2 for the designed BPF. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 989–991, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24208
A FDTD algorithm for the analysis of short optical pulse second harmonic generation in dispersive media
Authors: Alsunaidi M. A. , Alhajiri F. S. , Masoudi H. M.
Published: February 2009

A time‐domain nonlinear model representing the propagation of ultra‐short optical pulses in dispersive materials containing second order nonlinearity is presented. The model accounts for material dispersion through Lorentz model in addition to the spatiotemporal coupling between the pulsed fundamental and second harmonic beams. Numerical results for the generated second harmonic pulse clearly demonstrate the pulse break‐up phenomenon. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1097–1100, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24213
A novel wideband asymmetric hybrid antenna for WLAN/WiMAX applications
Authors: Lee Shiao‐Yu , Yu Cheng‐Chieh
Published: February 2009

A novel wideband wireless local area network/worldwide interoperability for microwave access (WLAN/WiMAX) hybrid antenna comprised of an asymmetric rectangular patch and additional strips is presented, including both simulation and measurement results. This proposed hybrid antenna exhibits wideband performance with sufficient bandwidth to meet the requirements of WLAN in the 2.4/5.2/5.8 GHz bands and WiMAX in the 2.5/3.5/5.5 GHz bands. Measurements show that the 10 dB return loss bandwidth (VSWR < 2) reaches as much as 5.59 GHz (= 7.92 GHz − 2.33 GHz). Moreover, the antenna gains at 2.45 GHz, 3.55 GHz, and 5.85 GHz are measured to be 4.596 dBi, 3.126 dBi, and 5.42 dBi, respectively. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1055–1057, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24215
A hybrid method for shape reconstruction of dielectric objects
Authors: Tezel Necmi Serkan
Published: February 2009

A Newton‐based Hybrid method for reconstruction of the shape of dielectric objects through the measured far‐field scattering data is given. The scattered field is represented as a single‐layer potential which leads to an ill‐posed integral equation of the first kind that is solved via Tikhonov regularization. The presented Newton‐based method combines ideas of both the iterative and decomposition methods and inherits the advantages of each of them, such as getting good reconstructions and not requiring a forward solver at each step. The numerical results show that the method yields good reconstruction. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1147–1151, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24218
Compact chip antenna applications in GPS by LTCC processing
Authors: Chung Yueh‐Ta , Sun Jwo‐Shiun , Wang Sea‐Fue , Huang Sheng‐Yi , Chiang Chuang‐Chung
Published: February 2009

A compact chip antenna is presented by using the low‐temperature cofired ceramics processing. Because of keeping the sintering temperature under 850°C, the 8.6CaO‐47.8B2O3‐43.6SiO2 (CBS‐10) glass system is adopted. The antenna is operated in the L‐band of Global Position System, 1.575 GHz. The total volume of the chip antenna is 10 × 10 × 2 mm3, and its size is reduced down to 36% which compares to using FR4 at the same frequency. As well as the performances of the far‐field radiation patterns are approximately to omnidirectional. The experimental results are consistent with the simulations. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1017–1019, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24219
Design of a miniature broad band planar inverted F‐type antenna
Authors: Huang Jhin‐Fang , Wen Jiun‐Yu , Huang Tai‐Pin
Published: February 2009

A broad band inverted F‐type antenna for ISM band is presented in this article. Bending method is adopted to reach miniaturization, and planar design makes it easy to fabricate. Reduced short‐circuit (RSC) plate, lower resonant frequency (LRF) for planar inverted F‐type antenna (PIFA) and inverted F‐type monopole antenna (IFMA) are applied to design a compact F antenna with the aid of a simulator, IE3D. Simulation and measurement are pretty matched and indicate that the LRF achieves −10 dB, bandwidth up to 304 MHz (12.4%) ranging from 2.332 to 2.636 GHz, and the peak gain to be 3 dBi. The RSC has a bandwidth up to 220 MHz (9%) ranging from 2.36 to 2.58 GHz, and the peak gain to be 2.5 dBi. The IFMA achieves triple bands, which are 210 MHz (8.5%) bandwidth at 2.4 GHz, and 3 GHz bandwidth ranging from 4.36 to 7.3 GHz for the second and third band applications. The measured antenna gains match to the simulation results and are about 0, 1.44, and 1.12 dBi for the 2.4, 5.2, 5.8 GHz bands frequencies, respectively. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1063–1070, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24224
An unconditionally stable wave equation PML algorithm for truncating FDTD simulation
Authors: Liang Feng , Lin Hai , Wang Gaofeng
Published: February 2009

An unconditionally stable (US) wave equation (WE) perfectly matched layer (PML) absorbing boundary condition is implemented for two‐dimensional (2‐D) open region finite‐difference time‐domain (FDTD) simulation by virtue of weighted Laguerre polynomial expansion. This novel PML preserves unconditional stability as well as comparative accuracy to the original wave equation PML (WEPML). Numerical examples are included to verify high accuracy and efficiency of the proposed algorithm. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1028–1032, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24233
A novel symmetrical monopole antenna for dual‐broadband operation
Authors: Lin C. , Zhang F.‐S. , Zhao G. , Zhang F. , Song Y.
Published: February 2009

A novel dual‐band monopole antenna that consists of symmetrical G‐shaped strips and triangular branches, fed by a 50‐Ω microstrip transmission line is introduced. The designed antenna is proposed for wireless local area networks (WLAN) applications in the 2.4 and 5.2/5.8 GHz bands. The measured results explore broadband dual‐frequency operation with (10 dB) impedance bandwidths of 21.4% cenetrd at 2.575 GHz, ranging from 2.30 to 2.85 GHz, and 32.8% centerd at 6.12 GHz from 5.10 to 7.14 GHz. The omnidirectional pattern, good gain, and broad bandwidth performances over the operating bands have been obtained by the proposed antenna with relatively low profile, which is suitable for dual‐broadband wireless communication systems. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 976–979, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24235
A 24‐GHz VCO using active FET frequency doubler in 0.18‐μm CMOS technology
Authors: Chen X.‐S. , Chen Y.‐T. , Lu C.‐L. , Chuang H.‐R.
Published: February 2009

In this article, a 24‐GHz VCO composed of a 12‐GHz VCO and an active frequency doubler is presented. This work is implemented by using the 0.18‐μm 1P6M CMOS process. The VCO and active frequency doubler with a 1.5 V supply consume 30 mA. The phase noise of measurement is −107.5 dBc/Hz and −123.1 dBc/Hz at 1‐MHz and 10‐MHz offset, respectively. A tuning range of 2.3 GHz is achieved by using varactor. The measurement shows a good efficiency of translation of frequency doubler and the oscillator has a good figure of merit (FOM) of −180 dBc/Hz. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 940–942, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24238
An EpHEMT‐based dual‐function integrated antenna for passive RFID transponders
Authors: Gómez C. , Aballo T. , García J. A. , Mediavilla A.
Published: February 2009

In this letter, a passive RFID transponder based on an enhancement mode pseudomorphic HEMT (EpHEMT) is proposed. Taking advantage of the slightly positive threshold voltage of this transistor technology, a dual‐function detector/mixer circuit with good RF‐to‐DC and frequency conversion efficiency has been designed. Such structure has been integrated in a conveniently designed aperture coupled patch, configuring the complete tag unit. On reception of an interrogating signal, the detector switches on the data generator circuit, being the information signal up‐converted near the interrogating frequency band through an optimized drain mixing configuration. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1117–1119, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24240
A novel Ku band left‐handed media antenna radome
Authors: Wu Wei‐Wei , Huang Jing‐Jian , Yuan Nai‐Chang
Published: February 2009

Antennas used in radar are expected to have high gain and low sidelobe. To achieve this end, this article presents a novel Ku band planar radome made by left‐handed materials, and then placed in front of an Archimedean spiral antenna element. The properties of the LHMs plane radomes are studied firstly, and the frequency band when the indexes of refraction of the LHMs plane radomes are negative is selected. Several LHMs planar radomes are developed. The gain of the antenna is tested on condition of several different parameters, such as the number of LHMs plane radomes, the distance between the antenna and these LHMs plane radomes, and the distance between two neighbor LHMs plane radomes. The beam is focused by the LHMs plane radomes. And comparing with the pattern of the antenna without these radomes, 5 dB more gain can be obtained by using LHMs planes radome. The electric level of the sidelobe is about −13.5 dB. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1043–1046, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24243