bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fiber birefringence measurement based on a beat‐frequency‐interrogated multilongitudinal‐mode distributed bragg reflector erbium‐doped fiber laser
Authors: Zhang Hao , Liu Bo , Jia Chenglai 
Published: January 2012

AbstractA novel fiber birefringence measurement scheme based on beat frequency interrogation of a multilongitudinal‐mode distributed Bragg reflector erbium‐doped fiber laser is presented and experimentally demonstrated. By analyzing the laser beat generation mechanism, an analytic expression describing fiber birefringence in terms of laser wavelength, laser beat frequency, and the fiber laser geometry has been obtained. Calculation of fiber birefringence based on the experimental observation of laser beat frequency shift indicates that the strain dependence of fiber birefringence turns out a perfect linear monotone decreasing relationship with a strain coefficient of ∼−2.2 × 10–11/με, which is in good agreement with related reports. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:702–707, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26630
A novel bear‐head‐shaped compact UWB monopole antenna enhanced with variable notch‐bands
Authors: Rezaeieh Sasan Ahdi , Abbak Mehmet 
Published: January 2012

AbstractA novel bear‐head‐shaped compact UWB antenna, with a variable notch‐band is proposed.It has a compact size of 22.5 × 22.5 × 1 mm3. It has variable stop bands that are obtained through changing U‐slot place on the patch, and it presents the selectable stop band frequency ranges. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:667–670, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26631
Reconfigurable penta‐band PIFA for small and slim mobile handsets
Authors: AbuTarboush Hattan F. , Nilavalan R. , Peter T. , Cheung S. W. , Budimir D. 
Published: January 2012

AbstractA small ultra‐thin planar inverted‐F antenna (PIFA) which can be switchable or tunable using PIN or varactor diodes, respectively, is proposed. The antenna consists of two radiators and connected together using two PIN or varactors diodes. Frequency reconfigurability is obtained by (i) tuning using varactor diodes or (ii) switching using PIN diodes. In the study, when varactors are used, the PIFA is optimized to operate in five frequency bands centered at 0.72, 1.35, 1.98, 3.6, and 5 GHz. Varying the voltages across the varactors can tune these five bands over the range of 45.33% (0.58–0.92 GHz), 17.77% (1.23–1.47 GHz), 26% (1.57–2.04 GHz), 6.66% (3.48–3.72 GHz), and 0.97% (4.99–5.04 MHz), covering the DVB‐H, GSM 800/900, GPS, PCS, DCS, UMTS, Wibro phase III, WiMAX, WLAN systems, etc. If PIN diode switches are used instead, the frequency bands can be switched among different standards, including the DVB‐H, GSM, UMTS, DCS, GPS, WiMAX, and WLAN systems, depending on the switching states. The two radiators are supported using a shorting wall and a shorting pin connected to a small ground plane. Results of intensive investigations using computer simulations and measurements show that the ground plane size has little effects on the performance of the antenna. The effects of user's hand on the S11, radiation patterns and efficiency are also characterized. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:725–729, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26640
The effect of air bubbles on an underwater optical communications system for wireless sensor network applications
Authors: Hagem Rabee M. , Thiel David V. , O'Keefe Steven G. , Fickenscher Thomas 
Published: January 2012

AbstractAn underwater optical link is proposed for communication between sensors on a swimmer during training.Tests in still‐pool water, still‐spa water, and bubbles‐spa water demonstrated the attenuation of the signal. The system uses a light emitting device (LED) (520 nm) and optical detector and is operating at 520 nm. The attenuation constant was found to increase from 0.09 to 2.9 m−1 when the spa jets were turned on. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:729–732, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26664
Hybrid envelope tracking for efficiency enhancement in concurrent dual‐band PAs
Authors: Chen W. , Kwan A. , Ghannouchi F.M. 
Published: January 2012

AbstractA hybrid envelope tracking scheme is proposed for concurrent dual‐band power amplifiers (PAs). Ideal power supply sweeping measurement shows this scheme can improve the efficiency of dual‐band PAs effectively. The feasibility of this scheme is validated using baseband and analog co‐simulation with real large signal circuit models. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:662–664, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26667
Cystic Fibrosis: An unusual neonatal presentation
Authors: Sankaran Koravangattu , Kalapurackal Mila , Wiebe Sheldon 
Published: January 2012

AbstractIn mechanically ventilated neonates it is not uncommon to observe obstructive atelectasis from various causes. However it is extremely rare to see mucous plugging and massive pulmonary atelectasis in the absence of infection, aspiration, and respiratory distress syndrome in the first couple of days of life. In this report we describe a neonate born with cystic fibrosis (CF) who presented to us with hypoxic respiratory failure, pulmonary hypertension, and hypercarbia without lactic acedemia from sticky mucous plugging and massive lung collapse. Neonatal respiratory distress and wide spread pulmonary atelectasis has not been reported in infants born with CF. Pediatr Pulmonol. 2012; 47:620–622. © 2012 Wiley Periodicals, Inc.
Fluorine: A new element in protein design
Authors: Buer Benjamin C. , Marsh E. Neil G. 
Published: January 2012

AbstractFluorocarbons are quintessentially man‐made molecules, fluorine being all but absent from biology. Perfluorinated molecules exhibit novel physicochemical properties that include extreme chemical inertness, thermal stability, and an unusual propensity for phase segregation. The question we and others have sought to answer is to what extent can these properties be engineered into proteins? Here, we review recent studies in which proteins have been designed that incorporate highly fluorinated analogs of hydrophobic amino acids with the aim of creating proteins with novel chemical and biological properties. Fluorination seems to be a general and effective strategy to enhance the stability of proteins, both soluble and membrane bound, against chemical and thermal denaturation, although retaining structure and biological activity. Most studies have focused on small proteins that can be produced by peptide synthesis as synthesis of large proteins containing specifically fluorinated residues remains challenging. However, the development of various biosynthetic methods for introducing noncanonical amino acids into proteins promises to expand the utility of fluorinated amino acids in protein design.
Design and Assembly of Rotaxane‐Based Molecular Switches and Machines
Authors: Yang Wenlong , Li Yongjun , Liu Huibiao , Chi Lifeng , Li Yuliang 
Published: January 2012

AbstractMechanically interlocked molecules, such as catenanes and rotaxanes, are at the heart of the development of molecular machines chemistry. They are able to self‐organize, self‐assemble, and self‐control themselves into new materials with potential application as molecular devices. In this review, an overview of some recent progress on molecular machines is given, including new methodologies for their synthesis and self‐assembly and their recent applications as dual or multilevel fluorescent molecular switches, as potential sensors, and even as a molecular‐level transporter. In one development, a molecular machine containing a charge‐transfer chromophore was designed to generate controllable aggregate structures through the reversible movement of a macrocycle over a thread; this was done in order to better understand the application of a molecular shuttle in solid state. Light is shed on how the novel properties and functions of molecular machines are extended, and examples of the ways in which molecular machines have been applied to the design and process of intelligentized systems are provided.
Microarray application in prenatal diagnosis: a position statement from the cytogenetics working group of the Italian Society of Human Genetics (SIGU), November 2011
Authors: Novelli A. , Grati F. R. , Ballarati L. , Bernardini L. , Bizzoco D. , Camurri L. , Casalone R. , Cardarelli L. , Cavalli P. , Ciccone R. , Clementi M. , Dalprà L. , Gentile M. , Gelli G. , Grammatico P. , Malacarne M. , Nardone A. M. , Pecile V. , Simoni G. , Zuffardi O. , Giardino D. 
Published: January 2012

AbstractA precise guideline establishing chromosomal microarray analysis (CMA) applications and platforms in the prenatal setting does not exist. The controversial question is whether CMA technologies can or should soon replace standard karyotyping in prenatal diagnostic practice. A review of the recent literature and survey of the knowledge and experience of all members of the Italian Society of Human Genetics (SIGU) Committee were carried out in order to propose recommendations for the use of CMA in prenatal testing. The analysis of datasets reported in the medical literature showed a considerable 6.4% incidence of pathogenic copy number variations (CNVs) in the group of pregnancies with sonographically detected fetal abnormalities and normal karyotype. The reported CNVs are likely to have a relevant role in terms of nosology for the fetus and in the assessment of reproductive risk for the couple. Estimation of the frequency of copy number variations of uncertain significance (VOUS) varied depending on the different CMA platforms used, ranging from 0–4%, obtained using targeted arrays, to 9–12%, obtained using high‐resolution whole genome single nucleotide polymorphism (SNP) arrays. CMA analysis can be considered a second‐tier diagnostic test to be used after standard karyotyping in selected groups of pregnancies, namely those with single (apparently isolated) or multiple ultrasound fetal abnormalities, those with chromosomal rearrangements, even if apparently balanced, and those with supernumerary marker chromosomes. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.
Callosal dysgenesis in fetuses with ventriculomegaly: levels of agreement between imaging modalities and postnatal outcome
Authors: Li Y. , Estroff J. A. , Khwaja O. , Mehta T. S. , Poussaint T. Y. , Robson C. D. , Feldman H. A. , Ware J. , Levine D. 
Published: January 2012

AbstractObjectiveTo assess neurodevelopmental outcome of fetuses diagnosed with callosal abnormalities after referral for ventriculomegaly.MethodsThis sub‐analysis of a prospective study of 430 fetuses, which were referred for ventriculomegaly and underwent sonography and magnetic resonance imaging (MRI), included those fetuses with a diagnosis of corpus callosal abnormalities after recruitment into the main study. Between three and six radiologists independently reviewed ultrasound and MR images and recorded central nervous system (CNS) abnormalities, with final diagnoses being decided by consensus. Postnatal outcomes of fetuses with callosal abnormalities were compared between those with and those without other abnormalities.ResultsCallosal abnormalities were detected in 13% (58/430) of the fetuses referred with ventriculomegaly. Callosal dysgenesis was isolated in 24% (14/58) of these cases, with the remainder complicated by CNS, karyotypic or other major abnormalities. Five fetuses diagnosed prenatally as having isolated callosal abnormalities had additional CNS findings on postnatal assessment. Preconference kappa for callosal abnormalities was 0.76 for ultrasound and 0.78 for MRI, indicating that these investigations had a similar level of operator dependence. Neurodevelopmental outcome was normal or showed only mild delay that resolved in 67% (8/12) children with isolated callosal abnormalities compared to 7% (2/27) in those with non‐isolated callosal abnormalities (P = 0.003).ConclusionCallosal abnormalities are present in a significant proportion of fetuses with a diagnosis of ventriculomegaly. Isolated callosal abnormalities are associated with normal neurodevelopmental outcome in approximately two‐thirds of fetuses.
Upscaling wind turbines: theoretical and practical aspects and their impact on the cost of energy
Authors: Sieros G. , Chaviaropoulos P. , Sørensen J. D. , Bulder B. H. , Jamieson P. 
Published: January 2012

ABSTRACTWind turbines with a rated power of 5 to 6 MW are now being designed and installed, mostly for offshore operation. Within the EU supported UpWind research project, the barriers for a further increase of size, up to 20 MW, are considered. These wind turbines are expected to have a rotor diameter up to 250 m and a hub height of more than 150 m. Initially, the theoretical implications of upscaling to such sizes on the weight and loads of the wind turbines are examined, where it is shown that unfavourable increases in weight and load will have to be addressed. Following that, empirical models of the increase in weight cost and loads as a function of scale are derived, based on historical trends. These include the effects of both scale and technology advancements, resulting in more favourable scaling laws, indicating that technology breakthroughs are prerequisites for further upscaling in a cost‐efficient way. Finally, a theoretical framework for optimal design of large wind turbines is developed. This is based on a life cycle cost approach, with the introduction of generic models for the costs, as functions of the design parameters and using basic upscaling laws adjusted for technology improvement effects. The optimal concept or concepts is obtained as the one that minimizes the total expected costs per megawatt hour (levelized production costs). Copyright © 2011 John Wiley & Sons, Ltd.
Structural analysis and optimisation of transverse flux permanent magnet machines for 5 and 10 MW direct drive wind turbines
Authors: Zavvos A. , Bang D. , McDonald A.S. , Polinder H. , Mueller M. 
Published: January 2012

ABSTRACTThe transverse flux permanent magnet generator offers high power density in terms of active mass. Two configurations of this machine topology (referred to as TFPM‐1 and TFPM‐2) are described, and optimised electromagnetic designs are presented. Direct drive generators require a significant support structure, which is designed to minimise the deflection into the air gap due to inherent electromagnetic attraction forces. The design of these structures is also dependant upon the generator topology. Structural design tools, which can be used in a design office environment, have been developed for the transverse flux machine and verified using commercial numerical modelling packages. Generic disc and arm structures are used. Only static analysis has been performed, but this does provide the designer with an estimate for more detailed design. A comparison of mass is made between the two transverse flux machines and a more conventional iron‐cored permanent magnet generator. The comparison shows that TFPM‐2 has the lowest total mass at 5 and 10 MW, but the conventional iron‐cored machine is lighter than TFPM‐1. Copyright © 2012 John Wiley & Sons, Ltd.
A Helical Silver(I) Complex with 2‐Pyrimidylthioacetate: Structure Variation through Partial Change of Ligand
Authors: Huang Yong‐Qing , Zhao Wei , Chen Jian‐Gu , Zhu Zhao‐Jie , Zhang Hui 
Published: January 2012

AbstractA chiral helical coordination polymer [Ag(pmta)]n (1) was prepared by the reaction of the asymmetric organic spacer 2‐pyrimidylthioacetic acid (Hpmta) with silver(I) acetate. Complex 1 has a hetero‐chiral coaxial helical structure, which is further extended into a 2D network structure by various supramolecular interactions. Furthermore, complex 1 exhibits strong fluorescence emission in the solid state and modest power second‐harmonic‐generation (SHG) efficiency at room temperature.
Inhibition of Macrophage Oxidative Stress Prevents the Reduction of ABCA‐1 Transporter Induced by Advanced Glycated Albumin
Authors: de Souza Pinto Raphael , Castilho Gabriela , Paim Bruno Alves , Machado‐Lima Adriana , Inada Natalia M. , Nakandakare Edna Regina , Vercesi Aníbal Eugênio , Passarelli Marisa 
Published: January 2012

AbstractWe investigated the role of aminoguanidine and benfotiamine on the inhibition of reactive oxygen species (ROS) generation in macrophages induced by advanced glycated albumin (AGE‐albumin) and its relationship with cell cholesterol homeostasis, emphasizing the expression of the ATP binding cassette transporter A‐1 (ABCA‐1). AGE‐albumin was made by incubating fatty acid‐free albumin with 10 mM glycolaldehyde. ROS production and ABCA‐1 protein level were determined by flow cytometry in J774 macrophages treated along time with control (C) or AGE‐albumin alone or in the presence of aminoguanidine or benfotiamine. Mitochondrial function was evaluated by oxygraphy. Compared to C‐albumin, AGE‐albumin increased ROS production in macrophages, which was ascribed to the activities of NADPH oxidase and of the mitochondrial system. Mitochondrial respiratory chain activity was reduced in cells incubated with AGE‐albumin. ROS generation along time was associated with the reduction in macrophage ABCA‐1 protein level. Aminoguanidine prevented ROS elevation and restored the ABCA‐1 content in macrophages; on the other hand, benfotiamine that promoted a lesser reduction in ROS generation was not able to restore ABCA‐1 levels. Inhibition of oxidative stress induced by AGE‐albumin prevents disturbances in reverse cholesterol transport by curbing the reduction of ABCA‐1 elicited by advanced glycation in macrophages and therefore may contribute to the prevention of atherosclerosis in diabetes mellitus.
Characterization of Free and Bound Lipids among Four Corn Genotypes as Affected by Drying and Storage Temperatures
Authors: Rezaei Karamatollah , Beta Trust , Bern Carl J. , White Pamela J. 
Published: January 2012

AbstractFor whole grains, the most sensitive components to the environmental changes are the lipids. In the current study, the effects of drying temperature (27 and 93 °C) and storage temperature (4 and 27 °C) on the fatty acid (FA) levels and lipid classes of endosperm lipids on four selected corn genotypes were investigated during a 12‐month storage period. Storage temperature indicated greater impact on the FA composition than did the drying temperature. The ratio of saturated to unsaturated fatty acids, which was around 0.20–0.22 levels in the free lipid (FL) fractions of all corn types studied here, did not change significantly due to the drying and storage temperatures. However, in the bound lipid (BL) fractions, it was changed by a change in the drying and storage temperature in some of the corn types. Some changes were also found in the lipid classes within the FL and BL fractions of the studied corn samples. No lysophosphatidylcholine (LPC) was found in the FL fractions. In the BL fractions of two of the corn samples, the level of free fatty acids (FFA) increased more likely due to the deterioration of LPC. The results of the current study indicated a possible migration of triglycerides and FFA between the FL and BL fractions due to drying and storage at higher temperatures.
A Retrospective Multi-Centre Study on the Outcome of Laparoscopic Simple Nephrectomies
Authors: El Kafsi Jihène , Sullivan Mark , Jones Adam 
Published: January 2012

Objective: A review of our experience in laparoscopic simple nephrectomies from May 2003 to May 2011 in the Urology Departments in Oxford and Reading. Method: A total of 100 patients, median age 46years (IQR = 27, range 17–82) underwent a laparoscopic simple nephrectomy for benign disease in the 8-year period reviewed. Data on patient demographics, pre-operative diagnosis, operating time, operative approach, estimated blood loss, in hospital post-operative complications and length of stay were collected from electronic databases held in the departments and regularly updated. Results: 100 laparoscopic simple nephrectomies were performed between May 2003 and May 2011. Median operating time was 180min (IQR = 60min, range 75–375min). Median estimated blood loss was 50ml (IQR = 50ml, range 10–1000ml). Median length of stay was 3 days (IQR = 3, range 2–14 days). No patients suffered from significant changes in renal function. Three patients were transfused between 2 and 3 units. 26 complications were recorded for 22 patients. Four were Clavien grade IIIb and 22 were grades I—II. Conclusion: Although laparoscopic simple nephrectomy is feasible and confers the usual benefits of laparoscopy it is often a technically challenging procedure. We used the Clavien Classification to standardise complications of laparoscopic simple nephrectomies. The term “simple” nephrectomy is misleading and should be changed.
Prenatal care and basic emergency obstetric care services provided at primary healthcare facilities in rural Nigeria
Authors: Okoli Ugo , Abdullahi Mohammed J. , Pate Muhammad A. , Abubakar Isa S. , Aniebue Nonye , West Charles 
Published: January 2012

AbstractObjectiveTo assess the availability of prenatal care and basic emergency obstetric care services at primary healthcare (PHC) facilities in rural Nigeria.MethodsIn total, 652 PHC facilities enrolled in the Midwives Service Scheme, a government‐funded program designed to reduce the national shortage of skilled birth attendants, were surveyed.ResultsIn all, 44.0% of the PHC facilities evaluated did not provide all components of prenatal care, and only 39.0% of all pregnant women nationwide attended prenatal care clinics 4 or more times. In addition, 52.2% of the facilities were not distributing insecticide‐treated nets to pregnant women, while only 36.8% of the PHC facilities provided services to prevent mother‐to‐child transmission of HIV. By contrast, 70.0% of the PHC facilities had access to antibiotics for the treatment of uncomplicated sepsis. Only 11.0% of clinics reported the use of vacuum extraction during labor and 36.8% provided post‐abortion care services. Treatment for pre‐eclampsia and eclampsia was initiated at 40.0% and 28.0% of PHC facilities, respectively, prior to referral.ConclusionThe present study provides useful information on the state of prenatal and basic emergency obstetric care in rural Nigeria. The data obtained indicate that changes are needed to achieve related Millennium Development Goals.
It’s All in the Timing: Simple Active Portfolio Strategies that Outperform Naïve Diversification
Authors: Kirby Chris , Ostdiek Barbara 
Published: January 2012

AbstractDeMiguel, Garlappi, and Uppal (2009) report that naïve diversification dominates mean-variance optimization in out-of-sample asset allocation tests. Our analysis suggests that this is largely due to their research design, which focuses on portfolios that are subject to high estimation risk and extreme turnover. We find that mean-variance optimization often outperforms naïve diversification, but turnover can erode its advantage in the presence of transaction costs. To address this issue, we develop 2 new methods of mean-variance portfolio selection (volatility timing and reward-to-risk timing) that deliver portfolios characterized by low turnover. These timing strategies outperform naïve diversification even in the presence of high transaction costs.