bluuebunny/crossref_metadata_2025 huggingface dataset:
Two New Electric Coupling Structures for Double Folded Substrate Integrated Waveguide Cavity Filters with Transmission Zeros
Authors: Yang Guang , Liu Wei , Liu Falin
Published: May 2013

Two electric coupling structures for double folded substrate integrated waveguide (DFSIW) cavity filters are presented in this article. The coupling strength can be easily tuned, and the coupling mechanism is investigated. With electric coupling realized by the proposed structures in the main path and magnetic coupling by a conventional coupling structure in the cross coupling path, an X‐band cross‐coupled filter is designed, which possesses a transmission zero on either side of the passband. A prototype of the filter is fabricated to validate the predicted frequency response, and the measured results agree with the simulated ones. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1815–1818, 2013
A Novel Beam Steering of Hybrid Switchable Beam Textile Antenna
Authors: Jais, Mohd I. , Jamlos, M. F. , Jusoh, Muzammil , Sabapathy, Thenna , Kamarudin Muhammad R.
Published: May 2013

A novel hybrid switchable beam textile antenna (HSBTA) is proposed in this research. The HSBTA introduced by a coaxial probe technique to feed current flow to center of HSBTA and distribute the current to four circles of radiating elements. This research found that the integration of RF switches and electronic components is successfully embedded into wearable textile antenna using a silver‐conductive epoxy adhesive. The four RF switches are then incorporated at four ideal locations of HSBTA's circle radiating elements to generate the beam steering ability with directivity as high as 6.8 dBi. With the help of particular RF switching scheme, the HSBTA has successfully tailored the beam to four different angles of 0°/360°, 90°, 180°, and 270° at single operating frequency of 2.45 GHz. Dimensionwise, 88 × 88 mm2 could lead the HSBTA to be deployed on smart garment for wireless body area network application. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1893–1897, 2013
Design of a Microwave Bandpass Filter with Compact Size and Wide Stopband
Authors: Sheen Jyh , Cheng Yang‐Hung , Liu Weihsing
Published: May 2013

This article presents a design of a microstrip bandpass filter (BPF) with a compact size and wide stopband. The wide stopband is achieved by suppressing the first and second harmonic resonance frequencies. The slow‐wave coupling stepped impedance resonator with cross‐coupled structure is adopted to design the BPF. The two‐resonator filter was fabricated with a 2.45‐GHz center frequency and 0.245‐GHz bandwidth using the Roger 4003C substrate. The device was simulated using the ADS design software. This device has shown a compact size and very low insertion loss. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1860–1863, 2013
Small‐Size Planar LTE/WWAN Antenna and Antenna Array Formed by the Same for Tablet Computer Application
Authors: Wong Kin‐Lu , Jiang Huan‐Jynu , Weng Teng‐Wei
Published: May 2013

For eight‐band LTE/WWAN operation (704–960/1710–2690 MHz) in the Ultrabook or thin‐profile tablet computer, a planar antenna of simple structure and small size is presented. The proposed antenna is obtained by modifying a simple planar inverted‐F antenna and can be printed on one surface of a thin FR4 substrate of size 10 × 45 mm2 only. The antenna's lower band bandwidth is greatly widened by embedding a proper chip capacitor of 2.7 pF at the feeding strip. This chip capacitor combines with the antenna's shorting strip can control the excitation of a parallel resonance to modify the impedance matching of the antenna's lower band such that a widened bandwidth is easily obtained to cover the LTE700/GSM850/900 operation. Conversely, the antenna's upper‐band bandwidth is also greatly enhanced by using a coupled section in the antenna's radiating strip and adding a parasitic shorted strip near the feeding strip, which lead to multiple resonant modes excited to form a wide bandwidth (>1 GHz) to cover the GSM1800/1900/UMTS/LTE2300/2500 operation. Owing to its small size and simple structure, the proposed antenna is very suitable to be applied in achieving an antenna array with high isolation for MIMO or dual talk (dual WWAN) operation. Promising high‐isolation antenna arrays formed by the proposed antennas are presented. The obtained isolation between the antennas in the antenna array is better than 12 dB, and the envelope correlation coefficient is less than 0.15 for frequencies over the LTE/WWAN bands. Details of the proposed antenna and antenna array are presented. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1928–1934, 2013
Design of A Compact Printed Double‐Sided Dual‐Band Dipole Antenna by Fdtd for Wifi Application
Authors: Huang Jhin‐Fang , Lai Wen‐Cheng
Published: May 2013

This paper presents a novel design of printed doubled‐sided dipole antenna for WiFi application in 2.4 and 5.2 GHz ISM bands. The printed dipole antenna consists of one dipole arranged back to back on both sides of a dielectric substrate and is suitable for integration with monolithic microwave integrated circuit (MMIC) module. A microstrip tapered feed line is designed to match the antenna. Simulator FDTD is used to tune and verify the analysis. Both simulated and measured data are much identical. The printed dual‐band dipole antenna with the dimension of 46 × 36 mm2 achieves a measured gain at 2.4 GHz band to be about 1.7 dBi with a bandwidth of 200 MHz and at 5.2 GHz band to be about 0 dBi with a bandwidth of 400 MHz, respectively. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1845–1851, 2013
Low Sar Multiband CPW‐Fed Pifa with Independent Resonant Frequency Control for Wireless Communication Applications
Authors: Soliman Ahmed M. , Elsheakh Dalia M. , Abdallah Esmat A.
Published: May 2013

Low specific absorption rate (SAR) compact hexaband planar inverted‐F antenna (PIFA) with independent resonant frequency control has been studied in this letter. Two trapezoidal‐shaped slots are etched on the coplanar waveguide‐fed PIFA‐radiating plate to create two independent resonant frequencies as well as the fundamental PIFA itself. Three coupled slots are added within the ground plane to create an additional three independent resonant frequencies with slight effect on the other resonant frequencies. Multiband capabilities with bandwidth enhancement and acceptable SAR values are realized for different wireless communication applications. The SAR in the presence of human head is investigated by using CST 2012 Microwave Studio Hugo Voxil Model. The proposed antennas are fabricated, and there is a good agreement between measured and simulated results. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1802–1810, 2013
Wireless Interrogation of an Optically Modulated Resonant Tunnelling Diode Oscillator
Authors: Cantú, Horacio I. , Salgado, Henrique , Romeira, Bruno , Kelly, Anthony E. , Ironside, Charles N. , Figueiredo Jose M. L.
Published: May 2013

In this work, a resonant tunnelling diode‐photo‐detector based microwave oscillator is amplitude modulated using an optical signal. The modulated free running oscillator is coupled to an antenna and phase locked by a wireless carrier that allows remote extraction of the information contained in the modulation. An off‐the‐shelf demodulator has been used to recover the envelope of the baseband data originally contained in the optical signal. Data were successfully transmitted at a rate of 1 MSym/s with a bit error rate below 10−6. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1728–1730, 2013
Pseudo‐Elliptic Function Bandstop Filter with Shunt Foster Sections
Authors: Malherbe Johannes A. G. , Louw Johnnes J.
Published: May 2013

Filters with transmission zeros in the stopband have been shown to have superior rates of cutoff. Conventional Cauer filters give excellent performance but are relatively large and not always practically realizable. In this article, the design of a pseudo‐elliptic bandstop filter which employs only shunt Foster sections and unit elements is presented. The filter is of the same size as a Chebyshev filter of the same order, but has a performance comparable to a Cauer filter. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1758–1762, 2013
Erratum: Efficient Numerical Tool for the Analysis and Design of Reflectarrays Based on Cells with Three Parallel Dipoles
Authors: Florencio, Rafael , Boix Rafael R. , Carrasco Eduardo , Encinar, José A. , Losada Vicente
Published: May 2013

Originally published Microwave Opt Technol Lett 55:1212–1216, 2013. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1976, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27739 (Original article DOI 10.1002/mop.27533)
Electrodiagnosis of ulnar neuropathy at the elbow (Une): A bayesian approach
Authors: Logigian Eric L. , Villanueva Raissa , Twydell Paul T. , Myers Bennett , Downs Marlene , Preston David C. , Kothari Milind J. , Herrmann David N.
Published: May 2013

Introduction: In ulnar neuropathy at the elbow (UNE), we determined how electrodiagnostic cutoffs [across‐elbow ulnar motor conduction velocity slowing (AECV‐slowing), drop in across‐elbow vs. forearm CV (AECV‐drop)] depend on pretest probability (PreTP). Methods: Fifty clinically defined UNE patients and 50 controls underwent ulnar conduction testing recording abductor digiti minimi (ADM) and first dorsal interosseous (FDI), stimulating wrist, below‐elbow, and 6‐, 8‐, and 10‐cm more proximally. For various PreTPs of UNE, the cutoffs required to confirm UNE (defined as posttest probability = 95%) were determined with receiver operator characteristic (ROC) curves and Bayes Theorem. Results: On ROC and Bayesian analyses, the ADM 10‐cm montage was optimal. For PreTP = 0.25, the confirmatory cutoffs were >23 m/s (AECV‐drop), and <38 m/s (AECV‐slowing); for PreTP = 0.75, they were much less conservative: >14 m/s, and <47 m/s, respectively. Conclusions: (1) In UNE, electrodiagnostic cutoffs are critically dependent on PreTP; rigid cutoffs are problematic. (2) AE distances should be standardized and at least 10 cm. Muscle Nerve 49:337–344, 2014
Associations of leg fat accumulation with adiposity‐related biological factors and risk of metabolic syndrome
Authors: Zhang Xiaomin , Hu Emily A. , Wu Hongyu , Malik Vasanti , Sun Qi
Published: May 2013

Objective:

To examine associations between regional fat mass (FM) distribution and cardiometabolic risk factors among ethnic minority groups, such as non‐Hispanic blacks and Hispanics.

Design and Methods:

The associations among 8,802 US residents who participated in the 1999‐2004 US National Health and Nutrition Examination Survey were examined. Body composition was measured using dual‐energy X‐ray absorptiometry. Leg fat indices included leg FM, leg FM percent (FM%), leg to whole body FM ratio (leg/whole), and leg to trunk FM ratio (leg/trunk). The correlation between leg fat indices and adiposity‐related risk factors, as well as the association of these indices with metabolic syndrome (MetS) was evaluated.

Results:

After adjusting for covariates including age, gender, and trunk FM or trunk FM%, higher leg FM and leg FM% were, in general, correlated favorably with adiposity‐related risk factors and associated with lower odds of MetS in all ethnicities, including non‐Hispanic whites and blacks and Hispanic groups. In addition, in all multivariate‐adjusted models, leg/whole and leg/trunk ratios were strongly associated with lower levels of most risk factors and decreased odds of MetS in these ethnicities (all odds ratios comparing extreme quintiles < 0.1).

Conclusions:

Results show that leg fat accumulation is inversely associated with adiposity‐related biological factors and risk of MetS in both whites and ethnic groups, suggesting that regional fat distribution plays an important role in the etiology of adiposity‐related diseases in these populations.
PROP taster status interacts with the built environment to influence children's food acceptance and body weight status
Authors: Burd Carlye , Senerat Araliya , Chambers Earle , Keller Kathleen L.
Published: May 2013

Objectives:

Eating behaviors and obesity are complex phenotypes influenced by genes and the environment, but few studies have investigated the interaction of these two variables. The purpose of this study was to use a gene‐environment interaction model to test for differences in children's food acceptance and body weights.

Design and Methods:

Inherited ability to taste 6‐n‐propylthiouracil (PROP) was assessed as a marker of oral taste responsiveness. Food environment was classified as “healthy” or “unhealthy” based on proximity to outlets that sell fruits/vegetables and fast foods using Geographic Information Systems (GIS). The cohort consisted of 120 children, ages 4‐6 years, recruited from New York City over 2005‐2010. Home address and other demographic variables were reported by parents and PROP status, food acceptance, and anthropometrics were assessed in the laboratory. Based on a screening test, children were classified as PROP tasters or non‐tasters. Hierarchical linear models analysis of variance was performed to examine differences in food acceptance and body mass index (BMI) z‐scores as a function of PROP status, the food environment (“healthy” vs. “unhealthy”), and their interaction.

Results and Conclusion:

Results showed an interaction between taster status and the food environment on BMI z‐score and food acceptance. Non‐taster children living in healthy food environments had greater acceptance of vegetables than taster children living in healthy food environments (P ≤ 0.005). Moreover, non‐tasters from unhealthy food environments had higher BMI z‐scores than all other groups (P ≤ 0.005). Incorporating genetic markers of taste into studies that assess the built environment may improve the ability of these measures to predict risk for obesity and eating behaviors. Obesity (2012)
Genetic risk factors for BMI and obesity in an ethnically diverse population: Results from the population architecture using genomics and epidemiology (PAGE) study
Authors: Fesinmeyer Megan D. , North Kari E. , Ritchie Marylyn D. , Lim Unhee , Franceschini Nora , Wilkens Lynne R. , Gross Myron D. , Bůžková Petra , Glenn Kimberly , Quibrera P. Miguel , Fernández‐Rhodes Lindsay , Li Qiong , Fowke Jay H. , Li Rongling , Carlson Christopher S. , Prentice Ross L. , Kuller Lewis H. , Manson JoAnn E. , Matise Tara C. , Cole Shelley A. , Chen Christina T.L. , Howard Barbara V. , Kolonel Laurence N. , Henderson Brian E. , Monroe Kristine R. , Crawford Dana C. , Hindorff Lucia A. , Buyske Steven , Haiman Christopher A. , Le Marchand Loic , Peters Ulrike
Published: May 2013

Objective:

Several genome–wide association studies (GWAS) have demonstrated that common genetic variants contribute to obesity. However, studies of this complex trait have focused on ancestrally European populations, despite the high prevalence of obesity in some minority groups.

Design and Methods:

As part of the “Population Architecture using Genomics and Epidemiology (PAGE)” Consortium, we investigated the association between 13 GWAS‐identified single‐nucleotide polymorphisms (SNPs) and BMI and obesity in 69,775 subjects, including 6,149 American Indians, 15,415 African‐Americans, 2,438 East Asians, 7,346 Hispanics, 604 Pacific Islanders, and 37,823 European Americans. For the BMI‐increasing allele of each SNP, we calculated β coefficients using linear regression (for BMI) and risk estimates using logistic regression (for obesity defined as BMI ≥ 30) followed by fixed‐effects meta‐analysis to combine results across PAGE sites. Analyses stratified by racial/ethnic group assumed an additive genetic model and were adjusted for age, sex, and current smoking. We defined “replicating SNPs” (in European Americans) and “generalizing SNPs” (in other racial/ethnic groups) as those associated with an allele frequency‐specific increase in BMI.

Results:

By this definition, we replicated 9/13 SNP associations (5 out of 8 loci) in European Americans. We also generalized 8/13 SNP associations (5/8 loci) in East Asians, 7/13 (5/8 loci) in African Americans, 6/13 (4/8 loci) in Hispanics, 5/8 in Pacific Islanders (5/8 loci), and 5/9 (4/8 loci) in American Indians.

Conclusion:

Linkage disequilibrium patterns suggest that tagSNPs selected for European Americans may not adequately tag causal variants in other ancestry groups. Accordingly, fine‐mapping in large samples is needed to comprehensively explore these loci in diverse populations.
Impact of participant and interventionist race concordance on weight loss outcomes
Authors: Batch Bryan C. , Ard Jamy D. , Vollmer William M. , Funk Kristine , Appel Lawrence J. , Stevens Victor J. , Samuel‐Hodge Carmen , Loria Catherine M. , Hollis Jack F. , Svetkey Laura P.
Published: May 2013

Objective:

We have previously shown that racial composition of behavioral intervention groups does not affect achieved weight loss. However, it is unclear if the race of the interventionist affects intervention outcomes. The objective of this analysis is to estimate the impact of race concordance between participant and interventionist on weight change in the initial weight loss phase (phase I) of the Weight Loss Maintenance trial (WLM).

Design and Methods:

A total of 1,685 overweight or obese adults (BMI 25‐45 kg/m2) who were taking medication for hypertension and/or dyslipidemia participated in phase I of the WLM trial. All participants received a 6‐month intensive behavioral intervention in groups of 15‐20 facilitated by a trained interventionist. The main outcome is change in weight at 6 months.

Results:

Participants were on average 55 years of age, 67% female and 44% African American (AA). Three of seventeen interventionists were AA, 14 were non‐AA. Seventy‐three percent of participants shared race concordance with the interventionist. There was a small but statistically significant difference in weight change of participants who were the same race as the interventionist (−5.84 kg, s.e. 0.17) as compared with those who were not race concordant (−5.04 kg, s.e. 0.33), a difference of 0.8 kg, (P = 0.04). The impact of concordance on weight change differed by race (i.e., interaction of race and concordance was significant, P = 0.02).

Conclusions:

In a post hoc analysis of a group‐based behavioral intervention, race concordance for non‐AA participants was associated with slightly greater weight loss. Race concordance was not associated with weight loss for AA participants.
Body fat responses to a 1‐year combined exercise training program in male coronary artery disease patients
Authors: Pimenta Nuno M. , Santa‐Clara Helena , Sardinha Luís B. , Fernhall Bo
Published: May 2013

Objective:

To analyze the body fat (BF) content and distribution modifications in coronary artery disease (CAD) patients in response to a 1‐year combined aerobic and resistance exercise training (CET) program.

Design and Methods:

We followed two groups of CAD male patients for 12 months. One group consisted of 17 subjects (57 ± 12 years) who engaged in a CET program (CET group) and the other was a age‐matched control group of 10 subjects (58 ± 11 years). BF content and distribution were measured through dual energy X‐ray absorptiometry (DXA) at baseline and follow‐up.

Results:

We found no differences on body mass and BMI between baseline and end of follow‐up in both groups but, in CET group, we found significant reductions in all analyzed BF depots, including total BF (21.60 ± 6.00 vs. 20.32 ± 5.89 kg, P < 0.01), % total BF (27.8 ± 5.5 vs. 26.4 ± 5.4%, P < 0.05), trunk fat (12.54 ± 3.99 vs. 11.77 ± 4.01 kg, P < 0.05), % trunk fat (31.1 ± 6.9 and 29.2 ± 7.1%, P < 0.05), appendicular fat (8.22 ± 2.08 vs. 7.72 ± 2.037 kg, P < 0.01), % appendicular fat (25.7 ± 4.9 and 24.5 ± 4.9%, P < 0.05), and abdominal fat (2.95 ± 1.06 vs. 2.75 ± 1.10 kg, P < 0.05). Control group showed significant increase in appendicular fat (7.63 ± 1.92 vs. 8.10 ± 2.12 kg, P < 0.05).

Conclusions:

These results confirm the positive effect of CET on body composition of CAD patients, despite no changes in body mass or BMI. In this study, we observed no alterations on BF distribution meaning similar rate of fat loss in all analyzed BF depots. These results also alert for the limitations of BMI for tracking body composition changes.
Comparison of gross body fat‐water magnetic resonance imaging at 3 Tesla to dual‐energy X‐ray absorptiometry in obese women
Authors: Silver Heidi J. , Niswender Kevin D. , Kullberg Joel , Berglund Johan , Johansson Lars , Bruvold Morten , Avison Malcolm J. , Welch E.Brian
Published: May 2013

Objective:

Improved understanding of how depot‐specific adipose tissue mass predisposes to obesity‐related comorbidities could yield new insights into the pathogenesis and treatment of obesity as well as metabolic benefits of weight loss. We hypothesized that three‐dimensional (3D) contiguous “fat‐water” MR imaging (FWMRI) covering the majority of a whole‐body field of view (FOV) acquired at 3 Tesla (3T) and coupled with automated segmentation and quantification of amount, type, and distribution of adipose and lean soft tissue would show great promise in body composition methodology.

Design and Methods:

Precision of adipose and lean soft tissue measurements in body and trunk regions were assessed for 3T FWMRI and compared to dual‐energy X‐ray absorptiometry (DXA). Anthropometric, FWMRI, and DXA measurements were obtained in 12 women with BMI 30‐39.9 kg/m2.

Results:

Test–retest results found coefficients of variation (CV) for FWMRI that were all under 3%: gross body adipose tissue (GBAT) 0.80%, total trunk adipose tissue (TTAT) 2.08%, visceral adipose tissue (VAT) 2.62%, subcutaneous adipose tissue (SAT) 2.11%, gross body lean soft tissue (GBLST) 0.60%, and total trunk lean soft tissue (TTLST) 2.43%. Concordance correlation coefficients between FWMRI and DXA were 0.978, 0.802, 0.629, and 0.400 for GBAT, TTAT, GBLST, and TTLST, respectively.

Conclusions:

While Bland–Altman plots demonstrated agreement between FWMRI and DXA for GBAT and TTAT, a negative bias existed for GBLST and TTLST measurements. Differences may be explained by the FWMRI FOV length and potential for DXA to overestimate lean soft tissue. While more development is necessary, the described 3T FWMRI method combined with fully‐automated segmentation is fast (<30‐min total scan and post‐processing time), noninvasive, repeatable, and cost‐effective.
Consequences of obstructive sleep apnea on metabolic profile: A Population‐Based Survey
Authors: Togeiro Sonia M. , Carneiro Glaucia , Ribeiro Filho Fernando F. , Zanella Maria T. , Santos‐Silva Rogerio , Taddei Jose A. , Bittencourt Lia R.A. , Tufik Sergio
Published: May 2013

Objective:

Epidemiologic studies that control for potential confounders are needed to assess the independent associations of obstructive sleep apnea (OSA) with metabolic abnormalities. The aim of our study was to evaluate the associations of OSA with metabolic abnormalities among the adult population of Sao Paulo, Brazil.

Design and Methods:

Questionnaires were applied face‐to‐face, full night polysomnography (PSG) was performed, and blood samples were collected in a population‐based survey in Sao Paulo, Brazil, adopting a probabilistic three‐stage cluster sample method. The metabolic profile included fasting glucose, insulin, and lipid levels. The hepatic insulin resistance index was assessed by the homeostasis model assessment‐estimated insulin resistance (HOMAIR).

Results:

A total of 1,042 volunteers underwent PSG. Mild OSA and moderate to severe OSA comprised 21.2% and 16.7% of the population, respectively. Subjects with severe to moderate OSA were older, more obese, had higher fasting glucose, HOMAIR, and triglycerides (TG) levels than did the mild and non‐OSA group (P < 0.001). Multivariate regression analyses showed that an apnea‐hypopnea index (AHI) ≥15 and a time of oxy‐hemoglobin saturation <90% were independently associated with impaired fasting glucose, elevated TG, and HOMAIR.

Conclusions:

The results of this large cross‐sectional epidemiological study showed that the associations of OSA and metabolic abnormalities were independent of other risk factors.
Development and Validation Method for Simultaneous Quantification of Phenolic Compounds in Natural Extracts and Nanosystems
Authors: da Silva Sara Baptista , Oliveira Ana , Ferreira Domingos , Sarmento Bruno , Pintado Manuela
Published: May 2013

Introduction

Sage and savoury (Salvia sp. and Satureja montana, respectively) are plants used in traditional medicine. The quality control of their herbal formulations is of paramount concern to guarantee the expected biological activity of their anti‐oxidant compounds.

Objective

To establish a simple and effective high‐performance liquid chromatographic (HPLC) method to evaluate simultaneously quercetin and rosmarinic acid, in a pure form, in natural extracts (sage and savoury), and encapsulated into chitosan nanoparticles.

Methods

Chromatography was performed on an RP C18‐column, in a gradient mode with a mobile phase comprising methanol:formic acid:water 92.5:2.5:5 (v/v) at a flow rate of 0.75 mL/min and at wavelength of 280 nm.

Results

The method was specific, linear in the range of 0.05–1 mg/mL (R2 = 1.00), precise at the intraday and interday levels, accurate (recovery rate 90.5 ± 0.6%), and robust to changes in equipment conditions.

Conclusion

The method established was effective for quercetin and rosmarinic acid characterisation in natural extracts and in chitosan nanoparticles, allowing the loading capacity determination, the association efficiency as well as the in vitro release. Copyright © 2013 John Wiley & Sons, Ltd.
Peptides and peptidoaldehydes as substrates for the Pictet–Spengler reaction
Authors: Pulka Karolina , Slupska Marta , Puszko Anna , Misiak Maria , Wilczek Marcin , Kozminski Wiktor , Misicka Aleksandra
Published: May 2013

The Pictet–Spengler (PS) reaction was performed with various types of substrates: H‐Trp‐OMe and dipeptides with N‐terminal Trp as arylethylamine components and Z‐protected amino aldehydes and peptidoaldehydes as carbonyl components. We found that the C‐terminal part of Trp derivatives did not have any influence on the stereoselectivity of the reaction and the results are the same for simple esters of Trp and dipeptides.

On the contrary, the selectivity of the PS reaction with peptidoaldehydes with L configuration of the C‐terminus residue is totally different from that obtained with simple L‐amino aldehydes. It allows us to obtain cis stereoisomers, which cannot be isolated from the reaction with amino aldehydes. But the utility of the peptidoaldehydes as substrates for the PS reaction is reduced by the side formation of enamides which decrease the yield of cyclization. Copyright © 2013 European Peptide Society and John Wiley & Sons, Ltd.
Global changes in propagation of stationary waves in a warming scenario
Authors: Freitas Ana Carolina Vasques , Rao V. Brahmananda
Published: May 2013

An investigation of how stationary Rossby wave (SRW) propagation can change in response to the A2 climate change scenario is made using six coupled ocean–atmosphere general‐circulation models (OAGCM). The simulation results for the present‐day climate (1960–1990) are compared with the NCEP/NCAR and ECMWF ERA‐40 re‐analyses. The zonal wind, the SRW kinetic energy (KE) pattern along the waveguide and the stationary wave‐number are used to analyse the changes in the SRW propagation for the winter season of each hemisphere. The main result shows that in future climate (2069–2099) the SRW propagation for longer distances is unfavourable for the main waveguides in the Northern Hemisphere (NH) and Southern Hemisphere (SH), which is confirmed through the SRW KE decrease. A poleward shift of the subtropical jet stream in future climate is also shown by five models in the SH and by three in the NH.
In situ13CO2 pulse‐labeling in a temperate heathland – development of a mobile multi‐plot field setup
Authors: Reinsch Sabine , Ambus Per
Published: May 2013

RATIONALE

Pulse‐labeling with 13CO2 and the subsequent analysis of 13C‐carbon via isotope ratio mass spectrometry (IRMS) have been shown to be an excellent method to investigate the terrestrial carbon cycle. Improving 13CO2 manipulation experiments will facilitate our understanding of carbon cycling processes.

METHODS

A mobile field setup for in situ 13CO2 pulse‐labeling was developed for low vegetation field experiments. Two pulse‐labeling experiments were conducted in a Danish heathland in September 2010 (Exp1) and May 2011 (Exp2). A flow‐through system was developed where labeling chambers were supplied with 13CO2‐enriched air from a gas reservoir. Reservoir and chamber air was sampled over the course of the experiments and analyzed for CO2 concentration and isotopic composition on a GasBench II interfaced with an isotope ratio mass spectrometer. The soil CO2 efflux and the atom% excess in soil respiration were assessed after the 13CO2‐pulse to verify the setup performance.

RESULTS

The carbon dioxide concentrations and 13CO2 enrichments were stable during the experiments. The CO2 concentrations conformed to the aimed values, whereas the 13CO2 enrichments were lower than expected. The sources of error for the deviation in observed atom% 13CO2 values are discussed, and a measurement procedure is suggested for samples highly enriched in 13C by using adjusted resistor settings of the mass spectrometer. However, more work has to be done. Enrichment patterns in soil respiration agree with published observations indicating satisfactory performance of the developed system.

CONCLUSIONS

A mobile flow‐through system suitable for continuous in situ 13CO2 pulse‐labeling was successfully developed that is easily applicable in remote natural ecosystems. Copyright © 2013 John Wiley & Sons, Ltd.
Laser microdissection and atmospheric pressure chemical ionization mass spectrometry coupled for multimodal imaging
Authors: Lorenz Matthias , Ovchinnikova Olga S. , Kertesz Vilmos , Van Berkel Gary J.
Published: May 2013

RATIONALE

Improvement in spatial resolution of atmospheric pressure molecular chemical imaging is required to resolve distinct surface features in the low micrometer and sub‐micrometer scale. Laser capture microdissection systems have the capability to focus laser light to a few micrometers. This type of system, when employed for laser ablation (LA) mass spectrometry (MS)‐based chemical imaging, has the potential to achieve high spatial resolution with multimodal optical and chemical imaging capability.

METHODS

A commercially available laser capture microdissection system was coupled to a modified ion source of a mass spectrometer. This design allowed for sampling of laser‐ablated material via a transfer tube directly into the ionization region. Ionization of the ablated material was accomplished using atmospheric pressure chemical ionization (APCI).

RESULTS

Rhodamine 6G dye of red permanent marker ink in a laser etched pattern as well as cholesterol and phosphatidylcholine in a cerebellum mouse brain thin tissue section were identified and imaged from the mass spectral data. Employing a spot diameter of 8 µm using the 10× microscope cutting objective and lateral oversampling resulted in a pixel size of about 3.7 µm in the same dimension. Distinguishing between features approximately 13 µm apart in a cerebellum mouse brain thin tissue section was demonstrated in a multimodal fashion co‐registering optical and mass spectral images.

CONCLUSIONS

A LA/APCI‐MS system was developed that comprised a commercially available laser microdissection instrument for transmission geometry LA and a modestly modified ion source for secondary ionization of the ablated material. The set‐up was successfully applied for multimodal imaging using the ability to co‐register bright field, fluorescence and mass spectral chemical images on one platform. Published in 2013. This article is a US Government work and is in the public domain in the USA.
Ultraviolet degradation of procymidone – structural characterization by gas chromatography coupled with mass spectrometry and potential toxicity of photoproducts using in silico tests
Authors: Rifai Ahmad , Souissi Yasmine , Genty Christophe , Clavaguera Carine , Bourcier Sophie , Jaber Farouk , Bouchonnet Stéphane
Published: May 2013

RATIONALE

Procymidone is a dicarboximide fungicide mainly used for vineyard protection but also for different crops. The structural elucidation of by‐products arising from the UV‐visible photodegradation of procymidone has been investigated by gas chromatography coupled with mass spectrometry. The potential toxicities of photoproducts were estimated by in silico tests.

METHODS

Aqueous solutions of procymidone were irradiated for up to 90 min in a self‐made reactor equipped with a mercury lamp. Analyses were carried out on a gas chromatograph coupled with an ion trap mass spectrometer operated in electron ionization and methanol positive chemical ionization. Multistage collision‐induced dissociation (CID) experiments were performed to establish dissociation pathways of ions. Toxicities of byproducts were estimated using the QSAR T.E.S.T. program.

RESULTS

Sixteen photoproducts were investigated. Chemical structures were proposed mainly based on the interpretation of multistage CID experiments, but also on their relative retention times and kinetics data. These structures enabled photodegradation pathways to be suggested. Only three photoproducts remain present after 90 min of irradiation. Among them, 3,5‐dichloroaniline presents a predicted rat LD50 toxicity about ten times greater than that of procymidone.

CONCLUSIONS

3,5‐Dichloroaniline is the only photoproduct reported in previous articles. Eight by‐products among the sixteen characterized might be as toxic, if not more, than procymidone itself considering the QSAR‐predicted rat LD50. Copyright © 2013 John Wiley & Sons, Ltd.
Covalent Functionalization of Dipole‐Modulating Molecules on Trilayer Graphene: An Avenue for Graphene‐Interfaced Molecular Machines
Authors: Nguyen Phong , Li Junwen , Sreeprasad T. S. , Jasuja Kabeer , Mohanty Nihar , Ikenberry Myles , Hohn Keith , Shenoy Vivek B. , Berry Vikas
Published: May 2013

The molecular dipole moment plays a significant role in governing important phenomena like molecular interactions, molecular configuration, and charge transfer, which are important in several electronic, electrochemical, and optoelectronic systems. Here, the effect of the change in the dipole moment of a tethered molecule on the carrier properties of (functionalized) trilayer graphene—a stack of three layers of sp2‐hybridized carbon atoms—is demonstrated. It is shown that, due to the high carrier confinement and large quantum capacitance, the trans‐to‐cis isomerisation of ‘covalently attached’ azobenzene molecules, with a change in dipole moment of 3D, leads to the generation of a high effective gating voltage. Consequently, 6 units of holes are produced per azobenzene molecule (hole density increases by 440 000 holes μm−2). Based on Raman and X‐ray photoelectron spectroscopy data, a model is outlined for outer‐layer, azobenzene‐functionalized trilayer graphene with current modulation in the inner sp2 matrix. Here, 0.097 V are applied by the isomerisation of the functionalized azobenzene. Further, the large measured quantum capacitance of 72.5 μF cm−2 justifies the large Dirac point in the heavily doped system. The mechanism defining the effect of dipole modulation of covalently tethered molecules on graphene will enable future sensors and molecular‐machine interfaces with graphene.
Diagnosis of uterine vein thrombosis on transvaginal ultrasound
Authors: Mavrelos D. , Cohen H. , Pateman K. , Hoo W. , Foo X. , Jurkovic D.
Published: May 2013

Deep venous thrombosis (DVT) is a potentially serious medical disorder, which may result in pulmonary embolism and death. Compression ultrasound is the investigation modality of choice for the diagnosis of DVT of the lower limb. Diagnosis of proximal thrombosis involving the pelvic veins is difficult and is usually made only after the thrombus extends into the veins of the lower limb. We present six cases of incidental uterine vein thrombosis diagnosed by transvaginal ultrasound. Our aim is to describe the technique of the examination of pelvic veins and criteria that could be used to diagnose uterine vein thrombosis. We also highlight difficulties in the management of women diagnosed with asymptomatic uterine vein thrombi as there is little evidence to guide clinicians in choosing between different treatment options. Copyright © 2013 ISUOG. Published by John Wiley & Sons Ltd.
Role of flexible alternating current transmission systems devices in mitigating grid fault‐induced vibration of wind turbines
Authors: Basu Biswajit , Staino Andrea , Basu Malabika
Published: May 2013

This paper focuses on the modeling of mechanical and structural vibrations in wind turbines due to the occurrence of electrical faults and an effective means of suppressing the vibrations with flexible alternating current transmission systems (FACTS) devices. A detailed model describing the dynamic interaction between the mechanical and the electrical subsystems of the turbine is presented. The model captures the effect of grid faults on the mechanical vibrations of drivetrain, flexible rotor blades and tower. Numerical investigation reveals that electrical disturbances have a significant impact on the mechanical/structural vibrations. In fact, the occurrence of severe vibrations due to voltage sags may compromise safe operation of the overall plant. The application of FACTS devices is then considered to suppress the effect of electrical fault‐induced vibrations. The performance comparison of static synchronous compensator and unified power quality conditioner devices in improving the mechanical/structural response has been carried out. A fault scenario compliant with Irish grid code has been simulated. Simulation results show that FACTS devices are successfully able to mitigate vibrations due to electrical faults, and they can be conveniently applied to stabilize the generator shaft speed, drivetrain oscillations, edgewise blade vibrations and tower responses. Further, superior performances of the unified power quality conditioner as compared with static synchronous compensator are also observed under certain conditions with increased fault duration. Copyright © 2013 John Wiley & Sons, Ltd.
The Prognostic Relevance of Psammoma Bodies and Ultrasonographic Intratumoral Calcifications in Papillary Thyroid Carcinoma
Authors: Pyo Jung‐Soo , Kang Guhyun , Kim Dong‐Hoon , Park Chanheun , Kim Joo Heon , Sohn Jin Hee
Published: May 2013

Background

Although psammoma bodies (PB) are found in up to 50 % of papillary thyroid carcinomas (PTC), their clinicopathological significance remains uncertain. The aim of the present study was to determine the clinicopathological significance of PB and the correlation between PB and ultrasonographic intratumoral calcification in PTC.

Methods

The clinicopathological parameters, ultrasonographic calcifications, and the presence of PB were evaluated in 258 surgically resected conventional PTC.

Results

Psammoma bodies were found in 141 of 258 PTC (54.7 %). The presence of PB was significantly correlated with tumor multifocality, extrathyroidal extension, and lymph node metastasis (P = 0.009, P = 0.004, and P < 0.001, respectively), but not with the BRAFV600E mutation. Higher incidences of both intratumoral and extratumoral PB were found in overt PTC (>1 cm) than in papillary microcarcinomas (≤1 cm) (P < 0.001 and P = 0.015, respectively). Extratumoral PB were only identified in 48.9 % of 141 PTC with PB, and PTC with extratumoral PB showed higher incidences of tumor multifocality, extrathyroidal extension, and nodal metastasis compared to PTC with intratumoral PB (P = 0.014, P = 0.005 and P = 0.001, respectively). Ultrasonographic intratumoral calcification corresponded to clusters of intratumoral PB (P < 0.001) and was associated with nodal metastasis (P = 0.026).

Conclusions

The findings of the present study suggest that the presence of PB may be a useful prognostic indicator of aggressive PTC behaviors. In addition, confirmation of ultrasonographic intratumoral calcification would be a useful decision‐making criterion when determining the need for preoperative or intraoperative surveillance of nodal metastasis.
Female mice heterozygous for creatine transporter deficiency show moderate cognitive deficits
Authors: Hautman Emily R. , Kokenge Amanda N. , Udobi Kenea C. , Williams Michael T. , Vorhees Charles V. , Skelton Matthew R.
Published: May 2013

Creatine transporter (CrT) deficiency (CTD) is an X‐linked disorder characterized by intellectual disability and speech delay. There have been reports that show female carriers have clinical symptoms. We have created CrT knockout (CrT−/y) mice in which males show severe cognitive deficits as a model of this disorder. The purpose of this study was to examine if the female carrier mice show cognitive deficits. Reductions in Cr levels as well as CrT transcript were observed in the brains of the female CrT+/− mice. CrT+/− mice show hyperactivity and increased latency to find the cued platform in the Morris water maze (MWM). CrT+/− female mice showed deficits in MWM hidden platform acquisition but not during reversal testing. Memory deficits on probe trials were observed during both phases. Novel object recognition memory and contextual fear memory were not affected in female CrT+/− mice. Female CrT+/− mice show moderate cognitive deficits, which is consistent with some of the human data. Female CrT+/− mice could prove to be beneficial in further understanding CTD and testing therapeutic approaches.
Sweet taste perception not altered after acute sleep deprivation in healthy young men
Authors: Hogenkamp P.S. , Nilsson E. , Chapman C.D. , Cedernaes J. , Vogel H. , Dickson S.L. , Broman J-E , Schiöth H.B. , Benedict C.
Published: May 2013

Background

We hypothesized that acutely sleep-deprived participants would rate ascending concentrations of sucrose as more intense and pleasant, than they would do after one night of normal sleep. Such a finding would offer a potential mechanism through which acute sleep loss could promote overeating in humans.

Method

A total of 16 healthy normal-weight men participated in 2 conditions: sleep (permitted between 22:30 and 06:30 h) and total sleep deprivation (TSD) respectively. On the morning after regular sleep and TSD, circulating concentrations of ghrelin and glucose were measured. In addition, participants hunger level was assessed by means of visual analogue scales, both before and after a caloric preload. Finally, following the preload, participants rated both intensity and pleasantness of six orally presented yogurt probes with varying sucrose concentrations (2–29 %).

Results

Feelings of hunger were significantly more intense under both fasted and sated conditions when subjects were sleep-deprived. In contrast, the change in hunger induced by the preload was similar between the sleep and TSD conditions. Plasma concentrations of ghrelin were significantly higher under conditions of TSD, whereas plasma glucose did not differ between the conditions. No effects were found either on sweet taste intensity or on pleasantness after TSD.

Conclusion

One night of TSD increases morning plasma concentrations of the hunger-promoting hormone ghrelin in healthy young men. In contrast, sweet taste perception was not affected by nocturnal wakefulness. This suggests that an altered sweet taste perception is an unlikely mechanism by which TSD enhances food intake.
Strategies for Preventing Distractions and Interruptions in the OR
Authors: Clark Gregory J.
Published: May 2013

Stakeholders in the automotive industry, airline industry, and anesthesia profession have identified critical periods of time in which distractions and interruptions of normal processes can have devastating effects. Just as reducing distractions improves safety in an automobile or airplane cockpit, limiting distractions and interruptions during critical times in the perioperative setting can increase patient safety. We assessed perioperative nurses and identified what they perceived as critical phases of nursing care. We also worked with our anesthesia partners to address their concerns about interruptions during the administration of nerve blocks. The perioperative nurses at our hospital initiated strategies to reduce distractions or interruptions to their practice at critical points, and, in collaboration with surgical committee members, we developed strategies to reduce or eliminate distractions for anesthesia professionals during the preoperative administration of nerve blocks and to eliminate distractions for the RN circulator and scrub person during the final counts.
Monocyte derived dendritic cells have reduced expression of co-stimulatory molecules but are able to stimulate autologous T-cells in patients with MDS
Authors: Davison Glenda M , Novitzky Nicolas , Abdulla Rygana
Published: May 2013

INTRODUCTION:

Research has implied that the immune system plays a role in the pathogenesis of MDS and that T-cells are reacting to tumour antigen present on the surface of the malignant cells. This could imply that the immune system could be utilized to generate immune based therapy. The aim of this pilot study was to examine the feasibility of studying this further by analysing the interaction of dendritic cells with T-cells in a small cohort of MDS patients.

METHODS:

Dendritic cells were generated in 6 MDS patients and 9 controls by culturing monocytes with GM-CSF and IL-4. After activation with LPS and TNFα, the dendritic cells were analyzed for expression of co-stimulatory and activation antigens. Thereafter, they were co-cultured with T-cells and the T-cell response was examined by measuring the % change in expression of the activation antigen CD69.

RESULTS:

MDS MoDC had reduced expression of HLA-DR (p=0.006), CD11c (p=0.0004), CD80 (p=0.03) and CD86 (p=0.003), while resting T-cells from MDS patients had higher expression of the activation antigen CD69 on all subsets. The % change in CD69 expression increased significantly for both the control and MDS T-cells after co-culture with allogeneic dendritic cells, however this change was lower in the MDS group. Despite the increased CD69 expression prior to culture, MDS MoDC significantly up-regulated CD69 expression on autologous T-cells to values that were statistically higher than control cells.

CONCLUSION:

This initial study suggests that the T-cells in MDS are able to respond to dendritic cells and are therefore probably not part of the malignant clone. It further implies that the dendritic cell population could be capable of presenting antigen and initiating an immune response and therefore further study is both feasible and warranted.
Regulatory expression of MMP‐8/MMP‐9 and inhibition of proliferation, migration and invasion in human lung cancer A549 cells in the presence of HGF variants
Authors: Ramanujum Rakesh , Lin Ya‐Ling , Liu Jong‐Kang , He Shiping
Published: May 2013

Hepatocyte growth factor (HGF), a potent cytokine of mesenchymal origin, exhibits polytrophic physiological responses, including proliferation, migration, and invasion, in a wide variety of cells. Although it is known that inhibition of the responses by HGF variants was via signal transducers and activators of the transcription pathway, the mechanisms of action of the variants involved in the production of matrix metalloproteinases (MMPs) were not clearly understood. Thus, recombinant HGF variants, NK1, NK2, NK3, and NK4 were topically applied to assays for proliferation, migration, invasion, and expression of MMPs in the human lung cancer cell line A549 and compared to that of control medium and a glutathione‐s‐transferase control. Results showed that these recombinant HGF variants significantly inhibited proliferation, migration, and invasion of A549 at >4 nM, downregulated expression of MMP‐9, and upregulated expression of MMP‐8. The study clearly suggests that binding of the HGF variants to the cell surface c‐Met resulted in the downregulation of MMP‐9, and upregulation of MMP‐8 protein expressions might be key molecular signals against proliferation, migration, and invasion of A549 cells.