bluuebunny/crossref_metadata_2025 huggingface dataset:
ChemInform Abstract: Diterpenoids of Terrestrial Origin
Authors: Hanson James R.
Published: February 2015

Review: isolation and chemistry; 190 refs.
ChemInform Abstract: Chiral Alkynylcarbinols from Marine Sponges: Asymmetric Synthesis and Biological Relevance
Authors: Listunov Dymytrii , Maraval Valerie , Chauvin Remi , Genisson Yves
Published: February 2015

Review: 121 refs.
ChemInform Abstract: Microwave‐Assisted Cycloaddition Reactions in Carbo‐ and Heterocyclic Chemistry
Authors: Saber Aziza , Marzag Hamid , Benhida Rachid , Bougrin Khalid
Published: February 2015

Review: 137 refs.
ChemInform Abstract: Safer, Greener, and More Facile Alternatives for Synthesis with Organic Azides
Authors: Sebeika Meaghan M. , Jones Graham B.
Published: February 2015

Review: 96 refs.
ChemInform Abstract: Cyclobutyl‐ and Cyclobutenylphosphonates: Synthesis, Transformations and Biological Activities
Authors: Al Aziz Al Quntar Abed , Srebnik Morris , Terent'ev Alexander O. , Dembitsky Valery M.
Published: February 2015

Review: 89 refs.
ChemInform Abstract: Enantioselective Hydrogenation Catalyzed by Chiral Nanoporous Materials
Authors: Li Xiaohong , Wu Peng
Published: February 2015

Review: 132 refs.
ChemInform Abstract: Catalytic Asymmetric Desymmetrization Approaches to Enantioenriched Cyclopentanes
Authors: Manna Madhu Sudan , Mukherjee Santanu
Published: February 2015

Review: [27 refs.
ChemInform Abstract: Mechanisms of Imine Exchange Reactions in Organic Solvents
Authors: Ciaccia Maria , Di Stefano Stefano
Published: February 2015

Review: [41 refs.
ChemInform Abstract: Redox Potentials and Acidity Constants from Density Functional Theory Based Molecular Dynamics
Authors: Cheng Jun , Liu Xiandong , Vande Vondele Joost , Sulpizi Marialore , Sprik Michiel
Published: February 2015

Review: 43 refs.
Study of balance of images using visual weight
Authors: Parada‐Castellano Raúl
Published: February 2015

The purpose of this research is to analyze the factors that create a sensation of balance or unbalance when a color image is observed depending on the light transmitted, reflected, and/or emitted by the objects that appear in it. This study is carried out by calculating the center of gravity (CG) of each image. The weight and the CG are obtained by calculating the force resulting from the different visual weights that make up the visual image and its position on this. When the visual CG and the geometric center coincide, it is recognized that the image is balanced. The action that acts on the balance of the lightness of an image is labeled as the visual weight. The visual weight of a figure is defined from the amount of visible light coming from it and the space occupied by this in the visual image. The colors show us the amount of light coming from a figure, while the shape provides us with information about the space that it occupies. The study explores how the qualities of appearance of three‐dimensional objects affect visual weight and how it can vary due to changes in light, motion of objects or the perspective of the image. Since these calculations can be very complex, we have developed the software called “PesoVisual” that automatically performs these operations on digital color images. Similarly, this software enables the analysis of the variability of the visual image. © 2015 Wiley Periodicals, Inc. Col Res Appl, 41, 175–187, 2016
Anti‐diabetic and neuroprotective effects of pancreatic islet transplantation into the central nervous system
Authors: Lazard Daniel , Vardi Pnina , Bloch Konstantin
Published: February 2015

During the last decades, the central nervous system (CNS) was intensively tested as a site for islet transplantation in different animal models of diabetes. Immunoprivilege properties of intracranial and intrathecal sites were found to delay and reduce rejection of transplanted allo‐islets and xeno‐islets, especially in the form of dispersed single cells. Insulin released from islets grafted in CNS was shown to cross the blood–brain barrier and to act as a regulator of peripheral glucose metabolism. In diabetic animals, sufficient nutrition and oxygen supply to islets grafted in the CNS provide adequate insulin response to increase glucose level resulting in rapid normoglycemia. In addition to insulin, pancreatic islets produce and secrete several other hormones, as well as neurotrophic and angiogenic factors with potential neuroprotective properties. Recent experimental studies and clinical trials provide a strong support for delivery of islet‐derived macromolecules to CNS as a promising strategy to treat various brain disorders. This review article focuses mainly on analysis of current status of intracranial and intrathecal islet transplantations for treatment of experimental diabetes and discusses the possible neuroprotective properties of grafted islets into CNS as a novel therapeutic approach to brain disorders with cognitive dysfunctions characterized by impaired brain insulin signalling. Copyright © 2015 John Wiley & Sons, Ltd.
Mesenchymal condensation‐dependent accumulation of collagen VI stabilizes organ‐specific cell fates during embryonic tooth formation
Authors: Mammoto Tadanori , Mammoto Akiko , Jiang Amanda , Jiang Elisabeth , Hashmi Basma , Ingber Donald E.
Published: February 2015

Background:

Mechanical compression of cells during mesenchymal condensation triggers cells to undergo odontogenic differentiation during tooth organ formation in the embryo. However, the mechanism by which cell compaction is stabilized over time to ensure correct organ‐specific cell fate switching remains unknown. Results: Here, we show that mesenchymal cell compaction induces accumulation of collagen VI in the extracellular matrix (ECM), which physically stabilizes compressed mesenchymal cell shapes and ensures efficient organ‐specific cell fate switching during tooth organ development. Mechanical induction of collagen VI deposition is mediated by signaling through the actin‐p38MAPK‐SP1 pathway, and the ECM scaffold is stabilized by lysyl oxidase in the condensing mesenchyme. Moreover, perturbation of synthesis or cross‐linking of collagen VI alters the size of the condensation in vivo. Conclusions: These findings suggest that the odontogenic differentiation process that is induced by cell compaction during mesenchymal condensation is stabilized and sustained through mechanically regulated production of collagen VI within the mesenchymal ECM. Developmental Dynamics, 2015. 244:713–723, 2015. © 2015 Wiley Periodicals, Inc.
Morphological and moisture availability controls of the leaf area‐to‐sapwood area ratio: analysis of measurements on Australian trees
Authors: Togashi Henrique Furstenau , Prentice Iain Colin , Evans Bradley John , Forrester David Ian , Drake Paul , Feikema Paul , Brooksbank Kim , Eamus Derek , Taylor Daniel
Published: February 2015

The leaf area‐to‐sapwood area ratio (LA:SA) is a key plant trait that links photosynthesis to transpiration. The pipe model theory states that the sapwood cross‐sectional area of a stem or branch at any point should scale isometrically with the area of leaves distal to that point. Optimization theory further suggests that LA:SA should decrease toward drier climates. Although acclimation of LA:SA to climate has been reported within species, much less is known about the scaling of this trait with climate among species.

We compiled LA:SA measurements from 184 species of Australian evergreen angiosperm trees. The pipe model was broadly confirmed, based on measurements on branches and trunks of trees from one to 27 years old. Despite considerable scatter in LA:SA among species, quantile regression showed strong (0.2 < R1 < 0.65) positive relationships between two climatic moisture indices and the lowermost (5%) and uppermost (5–15%) quantiles of log LA:SA, suggesting that moisture availability constrains the envelope of minimum and maximum values of LA:SA typical for any given climate.

Interspecific differences in plant hydraulic conductivity are probably responsible for the large scatter of values in the mid‐quantile range and may be an important determinant of tree morphology.
Towards Improved Policy and Institutional Coherence in the Promotion of Sustainable Biofuels in Mali
Authors: Favretto Nicola , Stringer Lindsay C. , Dougill Andrew J.
Published: February 2015

Interest in the promotion of biofuel investments to mediate the energy crisis and assist rural development is growing across sub‐Saharan Africa. However, empirical evidence on how policy can effectively promote sustainable biofuels is largely lacking. This paper presents new, multi‐level assessments of the implications of the Malian Strategy for Biofuels Development for the promotion of the oil‐bearing, non‐edible tree Jatropha curcas (Jatropha) as a sustainable development tool in Mali: a sub‐Saharan African country that has led Jatropha‐derived biofuel policy initiatives. In doing so, the paper addresses knowledge gaps on the role of national policy instruments in the uptake of biofuel activities. Semi‐structured interviews were undertaken with government departments, international organizations, private sector representatives, non‐governmental organizations and farming communities. Data show that mainstreaming internationally agreed principles into national policies is key to attract monetary, institutional and technical support from international organizations and donors. However, there are gaps between policy targets, actual yields and land cover. Jatropha oil supplies remain insufficient for improving access to fuel and substituting national consumption. Ambitious land cover targets set within national policies could risk land use shifts away from food towards biofuel production. Improved cooperation and coordination among state departments, enhanced monitoring of programmes and projects, as well as the establishment of adequate regulatory and fiscal frameworks governing private biofuel investments are needed to achieve sustainable outcomes. Copyright © 2015 John Wiley & Sons, Ltd and ERP Environment
Changing growth behavior of heavy‐metal tolerant bacteria: Media optimization using droplet‐based microfluidics
Authors: Wetzel Katharina , Cao Jialan , Kothe Erika , Köhler J. Michael
Published: February 2015

Overproduction of secondary metabolites requires know‐how for media optimization and design of effective screening procedures. Micro‐segmented flow was applied to test the growth characteristics of heavy‐metal tolerant soil bacteria (Bacillus sporothermodurans and Streptomyces tendae) toward changing media composition. The applied microfluidic technique was shown to be suitable for media optimization, with effects of media solutes like phosphorus and nitrogen, and a trace metal solution. For inorganic phosphate and trace metals, the synthesis of secondary metabolites had a much narrower tolerance for concentration ranges than vegetative cells. As we worked with metal‐tolerant strains, some tests were done in the presence of copper‐II ions in the bacteria‐specific critical concentration of 0.25 mM. In particular, for the Bacillus strain, the macronutrient phosphorus resulted in a threefold increase in growth with rising concentration. Copper led to a prolonged lag phase. For S. tendae, no similarly enhancing effect was observed. The trace metal solution promoted bacterial growth only in the case of S. tendae, for higher concentration ranges. For the nitrogen source, especially S. tendae responded with changes between the light scattering and the fluorescence signal. This could be a hint for the production of fluorescent secondary metabolites.
A dynamic channel access strategy for underlay cognitive radio networks: Markov modelling and performance evaluation
Authors: Jalali Elmira , Balapuwaduge Indika A. M. , Li Frank Y. , Pla Vicent
Published: February 2015

Unlike in overlay cognitive radio networks, secondary users in underlay cognitive radio networks can access licensed spectrum even at the presence of a primary user, given that the interference caused by the secondary transmission is lower than a pre‐specified threshold. Based on this underlay access principle, we propose in this paper a dynamic channel access strategy for multi‐channel cognitive radio networks. Different from existing underlay access techniques, channel assembling, spectrum adaptation and restricted channel occupancy are also considered in the proposed strategy in order to achieve better performance in the secondary network. Accordingly, a partial channel occupancy mode, which allows secondary users to access a portion of a channel when co‐existing with a primary user, is introduced in this study. The size of this portion is adjusted by selecting an appropriate value of a configurable parameter α in the partial channel occupancy mode. The system performance is evaluated for both primary and secondary networks, and a comparison analysis is carried out to assess the cost against the gain. Numerical results demonstrate that the proposed underlay channel access strategy outperforms the corresponding overlay strategy in terms of secondary network capacity, blocking probability and dropping probability. The cost and gain analysis identifies appropriate traffic conditions under which the overall system performance could be improved by employing the proposed underlay strategy. Copyright © 2015 John Wiley & Sons, Ltd.
Modern Management Practices and Hospital Admissions
Authors: McConnell K. John , Lindrooth Richard C. , Wholey Douglas R. , Maddox Thomas M. , Bloom Nick
Published: February 2015

We investigate whether the modern management practices and publicly reported performance measures are associated with choice of hospital for patients with acute myocardial infarction (AMI). We define and measure management practices at approximately half of US cardiac care units using a novel survey approach. A patient's choice of a hospital is modeled as a function of the hospital's performance on publicly reported quality measures and the quality of its management. The estimates, based on a grouped conditional logit specification, reveal that higher management scores and better performance on publicly reported quality measures are positively associated with hospital choice. Management practices appear to have a direct correlation with admissions for AMI—potentially through reputational effects—and indirect association, through better performance on publicly reported measures. Overall, a one standard deviation change in management practice scores is associated with an 8% increase in AMI admissions. Copyright © 2015 John Wiley & Sons, Ltd.
Desorption electrospray ionization‐based imaging of interaction between vascular graft and human body
Authors: Bodzon‐Kulakowska Anna , Drabik Anna , Mystkowska Joanna , Chlabicz Michal , Gacko Marek , Dabrowski Jan R. , Mielczarek Przemyslaw , Silberring Jerzy , Suder Piotr
Published: February 2015

The desorption electrospray ionization‐mass spectrometry imaging (DESI‐MSI) is known as a fast and convenient MS‐based method for lipid imaging in various biological materials. Here, we applied this technique to visualize lipid distribution in a vascular graft removed from a patient's body. This is a good example of the DESI system capabilities toward imaging of interaction between artificial material and living tissues. Detailed analysis allowed for visualization of the spatial distribution of selected lipids in this implanted, artificial material. Not only DESI‐MSI allowed visualization of lipid distribution in the investigated material but also enabled identification of the detected molecular species using MS/MS. Here, this technique was successfully used to evaluate the saturation and spatial distribution of endogenous lipids in the artificial vascular graft. Unambiguous identification of the lipids was done with the aid of fragmentation procedure. We also showed that various lipids localize preferably in graft material or internal plaque existing inside the graft. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 192–196, 2016.
Molecular Mechanisms Underlying the Regulation of the MFG‐E8 Gene Promoter Activity in Physiological and Inflammatory Conditions
Authors: Wang Xiao , Bu Heng‐Fu , Liu Shirley XL , De Plaen Isabelle G. , Tan Xiao‐Di
Published: February 2015

Milk fat globule‐EGF factor 8 (MFG‐E8) is expressed by macrophages and plays an important role in attenuating inflammation and maintaining tissue homeostasis. Previously, we and others found that lipopolysaccharide (LPS) inhibits MFG‐E8 gene expression in macrophages. Here, we characterized the 5'‐flanking region of the mouse MFG‐E8 gene. To functionally analyze the upstream regulatory region of the MFG‐E8 gene, a series of luciferase reporter gene constructs containing deleted or mutated regulatory elements were prepared. Using the luciferase assay, we revealed that Sp1 binding motifs within the proximal promoter region were necessary for full activity of the MFG‐E8 promoter, whereas AP‐1 like binding sequence at −372 played a role in governing the promoter activity at a homeostatic level. With chromatin immunoprecipitation assay, we showed that Sp1 and c‐Jun physically interact with the MFG‐E8 promoter region in vivo. In addition, Sp1 was found to regulate the MFG‐E8 promoter activity positively and c‐Jun negatively. Furthermore, we demonstrated that LPS inhibited MFG‐E8 promoter activity via targeting Sp1 and AP‐1‐like motifs in the 5'‐flanking region. Collectively, our data indicate that Sp1 and AP‐1‐related factors are involved in the regulation of MFG‐E8 gene transcription by targeting their binding sites in the 5'‐flanking region under physiological and inflammatory states. J. Cell. Biochem. 116: 1867–1879, 2015. © 2015 Wiley Periodicals, Inc.
Estimating π binding energy of N‐Heterocyclic carbenes: The role of polarization
Authors: Rezabal Elixabete , Frison Gilles
Published: February 2015

In this work, the tuneability of the π acceptor or donor properties of a set of N‐heterocyclic carbenes (NHCs) with a wide spectrum of electronic characteristics is established by means of density functional theory and energy decomposition analysis (EDA) tools. Even though the main orbital interaction contribution to the NHC coordination is the σ donation, a significant contribution of the π interactions to the bond is observed. By means of carefully selected coordination sites, different contributions to the π interactions could be identified and isolated. It includes not only the well known back donation and donation interactions, but also the intrafragment polarization, which has not been considered in previous studies. This can be obtained through the use of the extended transition state method for EDA combined with the natural orbitals for chemical valence and the constrained space orbital variation analysis. The contributions vary with the position of the heteroatoms and the presence of exocyclic substituents; the donation/backdonation π interactions between NHC and the coordination site can range between 2 and 61% of the total π orbital interactions, while the rest is owed to intrafragment polarization. Our results do not only contribute to the understanding of the electronic structure of NHC‐based complexes, giving ways to improve their catalytic properties, but also provide comprehension on the modelization methods used to study their donor–acceptor interactions. © 2015 Wiley Periodicals, Inc.
Gender Specificity of a Genetic Variant of Androgen Receptor and Risk of Coronary Artery Disease
Authors: Agiannitopoulos Konstantinos , Bakalgianni Angeliki , Marouli Eirini , Zormpa Ioanna , Manginas Athanasios , Papamenzelopoulos Spyros , Lamnissou Klea
Published: February 2015

Background

Androgens are known to influence the risk of developing cardiovascular diseases. This study aims at investigating the possible association between G1733A polymorphism in the coding region of androgen receptor (AR) gene and premature coronary artery disease (CAD).

Methods

A total of 460 Greek subjects were investigated for the G1733A polymorphism. The patient group consisted of 250 CAD individuals, aged less than 58 years, while 210 healthy individuals served as controls. Genotyping was performed using the PCR‐RFLP method.

Results

Significant differences in genotype distribution (P = 0.0067) and allele frequencies (P = 0.0060) have been observed between patients and controls in the women's subgroup. Conversely, the genotype/allele frequencies were similar between patients and controls in the subgroup of men.

Conclusion

We may conclude that the G1733A polymorphism of AR gene could be a useful genetic marker for the assessment of a woman's risk for CAD in our Caucasian Greek population.
Anchorage‐dependent binding of integrin I‐domain to adhesion ligands
Authors: Fu Xin , Xu Yan , Wu Chenyu , Moy Vincent T. , Zhang X. Frank
Published: February 2015

The dynamic interactions between leukocyte integrin receptors and ligands in the vascular endothelium, extracellular matrix, or invading pathogens result in leukocyte adhesion, extravasation, and phagocytosis. This work examined the mechanical strength of the connection between iC3b, a complement component that stimulates phagocytosis, and the ligand‐binding domain, the I‐domain, of integrin αMβ2. Single‐molecule force measurements of αM I‐domain–iC3b complexes were conducted by atomic force microscope. Strikingly, depending on loading rates, immobilization of the I‐domain via its C‐terminus resulted in a 1.3‐fold to 1.5‐fold increase in unbinding force compared with I‐domains immobilized via the N‐terminus. The force spectra (unbinding force versus loading rate) of the I‐domain–iC3b complexes revealed that the enhanced mechanical strength is due to a 2.4‐fold increase in the lifetime of the I‐domain–iC3b bond. Given the structural and functional similarity of all integrin I‐domains, our result supports the existing allosteric regulatory model by which the ligand binding strength of integrin can be increased rapidly when a force is allowed to stretch the C‐terminus of the I‐domain. This type of mechanism may account for the rapid ligand affinity adjustment during leukocyte migration. Copyright © 2015 John Wiley & Sons, Ltd.
Ultra‐performance liquid chromatography of amino acids for the quality assessment of pearl powder
Authors: Zhang Jingxian , Li Shangrong , Yao Shuai , Si Wei , Cai Luying , Pan Huiqin , Hou Jinjun , Yang Wenzhi , Da Juan , Jiang Baohong , Liu Xuan , Wu Wanying , Guo De‐an
Published: February 2015

Pearls have been widely used as a traditional medicine, in cosmetics, and as a health food supplement in China since ancient times. However, the identification and quality assessment of pearl powder have been challenging tasks because of the similar morphological features and chemical composition of its common adulterants, especially conch powders. In this study, ultra‐performance liquid chromatography was combined with pre‐column derivatization to rapidly quantify 14 amino acids in pearl powder and its analogues. Based upon the quantification results, a quality criterion of a total amino acid content of not less than 1.10% was proposed for pearl powder. Principal component analysis indicated that leucine and phenylalanine were the amino acids characteristic for distinguishing between pearls and nacres. The area ratio of leucine to phenylalanine was demonstrated to be an effective diagnostic marker to discriminate freshwater cultured pearls, natural seawater pearls, and nacres. The proposed method, involving both the qualitative and quantitative aspects, was subsequently applied to quality assessment of pearl powders purchased commercially in various parts of China; eight out of 18 batches were deemed authentic and unadulterated. In the future, this analytical process should play a significant role in standardizing and providing quality control to the pearl powder market.
Development of an ionic‐liquid‐based dispersive liquid–liquid microextraction method for the determination of antichagasic drugs in human breast milk: Optimization by central composite design
Authors: Padró Juan M. , Pellegrino Vidal Rocío B. , Echevarria Romina N. , Califano Alicia N. , Reta Mario R.
Published: February 2015

Chagas disease constitutes a major public health problem in Latin America. Human breast milk is a biological sample of great importance for the analysis of therapeutic drugs, as unwanted exposure through breast milk could result in pharmacological effects in the nursing infant. Thus, the goal of breast milk drug analysis is to inquire to which extent a neonate may be exposed to a drug during lactation. In this work, we developed an analytical technique to quantify benznidazole and nifurtimox (the two antichagasic drugs currently available for medical treatment) in human breast milk, with a simple sample pretreatment followed by an ionic‐liquid‐based dispersive liquid–liquid microextraction combined with high‐performance liquid chromatography and UV detection. For this technique, the ionic liquid 1‐octyl‐3‐methylimidazolium hexafluorophosphate has been used as the “extraction solvent.” A central composite design was used to find the optimum values for the significant variables affecting the extraction process: volume of ionic liquid, volume of dispersant solvent, ionic strength, and pH. At the optimum working conditions, the average recoveries were 77.5 and 89.7%, the limits of detection were 0.06 and 0.09 μg/mL and the interday reproducibilities were 6.25 and 5.77% for benznidazole and nifurtimox, respectively. The proposed methodology can be considered sensitive, simple, robust, accurate, and green.
Design of wideband single‐layer in‐phase power divider using microstrip to slotline coupled structure
Authors: Ahmed Ummee T. , Abbosh Amin M.
Published: February 2015

The design of a planar in‐phase power divider for wideband applications is presented. The proposed divider uses a broadside coupled microstrip/slotline configuration with an improved isolation between the output ports using suitable isolation resistor. The proposed design is suitable for single layer integration as both the input and output ports are located at the same layer. Although the device can be used for any wideband application, the developed prototype is designed to operate within the band 2–5 GHz, which is used in microwave‐based head imaging systems. The simulated and experimental results of the developed divider show equal power division with less than 0.5 dB of additional insertion loss, less than 2° of phase imbalance, more than 13 dB of isolation and more than 10 dB of return loss over the band 2.3–4.7 GHz. It has a compact size with an overall dimension of 30 × 30 mm2. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:789–791, 2015
Experimental and theoretical investigation of resonance and radiation characteristics of superstrate loaded rectangular patch antenna
Authors: Biswas Manotosh , Mandal Anirban
Published: February 2015

In this article, we present two models to predict the effective permittivity and effective patch length for computing the resonant frequency of superstrate loaded rectangular patch antenna. These models use a set of CAD oriented closed form expressions based on conformal mapping, transmission line and cavity model. These models are very simple and take less computational time. The accuracy of these models is verified against our new experimental results and previously reported experimental results available in open literature. To obtain the radiation characteristics and validate this structure electromagnetic software (HFSS) has been used. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:791–799, 2014
Temperature insensitive curvature sensor based on a combination interference structure and an intensity demodulation method
Authors: Zhao Yong , Gao Peng , Yang Yang
Published: February 2015

In this article, a sensing head consisting of fiber loop mirror inscribed with a highly Birefringence photonic crystal fiber (HiBi‐PCF) was proposed and experimentally demonstrated. The fully collapsed air holes of the PCF at the spice regions allow the coupling of PCF core and cladding modes that makes a Mach–Zehnder interferometer. The couple efficiency of the core mode to the cladding mode will be decreased as the curvature on the HiBi‐PCF part is increased. The curvature variation on the HiBi‐PCF part can be obtained by detecting the fringe visibility of the interference patterns. Experimental results show that the curvature sensor with maximal sensitivity of 10.171 dB/m−1 within a measurement range of 0–0.48 m−1 is obtained. Owing to the low thermo‐optic and thermo‐expansion coefficient of the HiBi‐PCF and with the using of intensity demodulation method, the proposed sensor can overcome the temperature and curvature cross‐sensitivity effects. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:806–809, 2015
Reverberation chamber modeling based on proportional dimension
Authors: Song Jian , Guo Yong Xin , Hui Hon Tat , Wang Hang , Sim Zhi Wei
Published: February 2015

This article presents an efficient method of modeling reverberation chambers (RCs) based on proportional dimensions. The motivation of this work is to predict the performance of a large‐size RC based on a proportionally reduced‐size scale model. Electromagnetic dimensional scale model in RC is explained, and the theory is deduced from Maxwell equation. Good agreements between simulation and measurement results have been observed and discussed. The large‐size RC simulation result fulfills the requirement in terms of electric field standard deviation based on the scaled model. It showed that using the scaled model to estimate a large‐sized RC is feasible, thus reducing the simulation time and saving computing power. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:838–841, 2015
A 42.15–68.35 dBΩ tunable gain transimpedance amplifier using 0.18‐μm CMOS process
Authors: Chang Yu‐Hsin , Chiang Yen‐Chung , Yang Ching‐Yuan
Published: February 2015

This letter proposes a transimpedance amplifier with a tunable gain fabricated in the 0.18‐μm CMOS process. The tunable gain range is from 42.15 to 68.35 dBΩ with a 2.88–3.52 GHz bandwidth, and its group delay is around 200 ps. With 2.5 Gb/s, 215−1, 223−1, and 231−1 pseudorandom bit sequence inputs, the corresponding recovered clock jitters are 7.72, 7.83, and 8.3 ps, respectively. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:830–832, 2015
CPW‐fed sqaure ring slot antenna with circular polarization radiation for WiMAX/WLAN applications
Authors: Sim Chow‐Yen‐Desmond , Chen Horng‐Dean , Zuo Liang , Chen Ting‐An
Published: February 2015

The design of a small size 50 × 50 mm2 coplanar waveguide‐fed square ring slot antenna is studied. To attain circular polarization (CP) radiation with broad 3‐dB axial ratio (AR) bandwidth that can cover the worldwide interoperability for microwave access 2.3 GHz (2305–2320 MHz, 2345–2360 MHz) and wireless local area network 2.4 GHz (2400–2480 MHz) bands, a novel technique of extending a C‐shaped branch from the vertical monopole is proposed. Good impedance matching and CP performance was achieved by further extending a vertical tuning strip from the C‐shaped branch. From the measured results, 10‐dB impedance bandwidth and 3‐dB AR bandwidth of 63.89% and 7.93% were achieved. Furthermore, stable gain variation of approximately 2.7 dBic and radiation efficiency of more than 85% were also exhibited across the bands of interest. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:886–891, 2015
Efficient two dipole antenna alignment in near‐field region
Authors: Kim Jae Hee , Lee Byung Song , Park Chan Bae , Bang Jin Kyu , Ahn Chi‐Hyung
Published: February 2015

This letter suggests an efficient dipole antenna alignment for the collinear dipoles and parallel nonstaggered dipoles in near‐field region, where a material shell or a metal plate is located between two dipole antennas. For an infinitesimal electric dipole in the material shell, a strong electric field direction of outer material and the distance to maintain the field dominantly regardless of the material properties have been calculated. Transmission coefficients of the two dipoles for the metal plate are simulated and measured at 900 MHz. Finally, it is proposed that the transmission performance of the collinear dipole alignment for both the material shell and metal environments is better than that of the parallel nonstaggered dipole alignment. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:933–937, 2015
UWB bandpass filter with quad‐notched bands using arrow‐shaped resonators
Authors: Guo Qingxin
Published: February 2015

An UWB bandpass filter with quad‐notched bands is presented in this letter. The filter is comprised of a seven‐pole pseudo‐bandpass filter which is based on optimum distributed highpass filters and eight arrow‐shaped resonators which provide four notched bands. The effects of the physical parameters of the arrow‐shaped resonators on the S parameter of the presented filter are detailed investigated. The presented filter is fabricated and measured after it has been meticulously designed on a RO4350B substrate whose dimensions are 50 × 12 × 0.508 mm3. Both simulation and experimental results are provided and compared with each other. Simulation results show that the notched frequencies can be altered by changing the physical parameters of the arrow‐shaped resonators. Measurement results show that, within 2.89–10.78 GHz, which is 3‐dB bandwidth of the bandpass filter, four notched bands centered at 3.53, 5.35, 5.85, and 8.08 GHz with the notch depth is higher than 16 dB are obtained. The current distributions of the notched frequencies and the frequency within the pass band are also investigated. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:959–963, 2015
Energetic adaptations persist after bariatric surgery in severely obese adolescents
Authors: Butte Nancy F. , Brandt Mary L. , Wong William W. , Liu Yan , Mehta Nitesh R. , Wilson Theresa A. , Adolph Anne L. , Puyau Maurice R. , Vohra Firoz A. , Shypailo Roman J. , Zakeri Issa F.
Published: February 2015

Objective

Energetic adaptations induced by bariatric surgery have not been studied in adolescents or for extended periods postsurgery. Energetic, metabolic, and neuroendocrine responses to Roux‐en‐Y gastric bypass (RYGB) surgery were investigated in extremely obese adolescents.

Methods

At baseline and at 1.5, 6, and 12 months post‐baseline, 24‐h room calorimetry, body composition, and fasting blood biochemistries were measured in 11 obese adolescents relative to five matched controls.

Results

In the RYGB group, mean weight loss was 44 ± 19 kg at 12 months. Total energy expenditure (TEE), activity EE, basal metabolic rate (BMR), sleep EE, and walking EE significantly declined by 1.5 months (P = 0.001) and remained suppressed at 6 and 12 months. Adjusted for age, sex, fat‐free mass, and fat mass, EE was still lower than baseline (P = 0.001). Decreases in serum insulin, leptin, and triiodothyronine (T3), gut hormones, and urinary norepinephrine (NE) paralleled the decline in EE. Adjusted changes in TEE, BMR, and/or sleep EE were associated with decreases in insulin, homeostatic model assessment, leptin, thyroid stimulating hormone, total T3, peptide YY3‐36, glucagon‐like peptide‐2, and urinary NE and epinephrine (P = 0.001‐0.05).

Conclusions

Energetic adaptations in response to RYGB‐induced weight loss are associated with changes in insulin, adipokines, thyroid hormones, gut hormones, and sympathetic nervous system activity and persists 12 months postsurgery.
Changes in body composition over 8 years in a randomized trial of a lifestyle intervention: The look AHEAD study
Authors: Pownall Henry J. , Bray George A. , Wagenknecht Lynne E. , Walkup Michael P. , Heshka Stanley , Hubbard Van S. , Hill James , Kahn Steven E. , Nathan David M. , Schwartz Anne V. , Johnson Karen C. ,   the Look AHEAD Research Group
Published: February 2015

Objective

To determine the effects of an intensive lifestyle intervention versus a comparison group on body composition in obese or overweight persons with type 2 diabetes at baseline and at 1, 4, and 8 years.

Methods

Body composition was measured by dual‐energy X‐ray absorptiometry in a subset of 1019 Look AHEAD study volunteers randomized to intervention or comparison groups. The intervention was designed to achieve and maintain ≥7% weight loss through increased physical activity and reduced caloric intake. The comparison group received social support and diabetes education.

Results

At 1 year, the intervention group lost fat (5.6 ± 0.2 kg) and lean mass (2.3 ± 0.1 kg) but regained fat (∼100%) and lost lean mass between years 1 and 8. Between baseline and year 8, weight loss was greater in intervention versus comparison groups (4.0 ± 0.4 vs. 2.3 ± 0.4 kg); comparison group weight loss was mostly lean mass (2.1 ± 0.17 kg). Fat mass in the intervention group was lower than that of the comparison group at all post‐baseline time points.

Conclusions

Reduced fat mass may place the intervention group at a lower risk of obesity‐linked sequelae, a hypothesis that can be tested by future studies of this cohort.
Neurological heterotopic ossification following spinal cord injury is triggered by macrophage‐mediated inflammation in muscle
Authors: Genêt François , Kulina Irina , Vaquette Cedryck , Torossian Frédéric , Millard Susan , Pettit Allison R , Sims Natalie A , Anginot Adrienne , Guerton Bernadette , Winkler Ingrid G , Barbier Valérie , Lataillade Jean‐Jacques , Le Bousse‐Kerdilès Marie‐Caroline , Hutmacher Dietmar W , Levesque Jean‐Pierre
Published: February 2015

Neurological heterotopic ossification (NHO) is the abnormal formation of bone in soft tissues as a consequence of spinal cord or traumatic brain injury. NHO causes pain, ankyloses, vascular and nerve compression and delays rehabilitation in this high‐morbidity patient group. The pathological mechanisms leading to NHO remain unknown and consequently there are no therapeutic options to prevent or reduce NHO. Genetically modified mouse models of rare genetic forms of heterotopic ossification (HO) exist, but their relevance to NHO is questionable. Consequently, we developed the first model of spinal cord injury (SCI)‐induced NHO in genetically unmodified mice. Formation of NHO, measured by micro‐computed tomography, required the combination of both SCI and localized muscular inflammation. Our NHO model faithfully reproduced many clinical features of NHO in SCI patients and both human and mouse NHO tissues contained macrophages. Muscle‐derived mesenchymal progenitors underwent osteoblast differentiation in vitro in response to serum from NHO mice without additional exogenous osteogenic stimuli. Substance P was identified as a candidate NHO systemic neuropeptide, as it was significantly elevated in the serum of NHO patients. However, antagonism of substance P receptor in our NHO model only modestly reduced the volume of NHO. In contrast, ablation of phagocytic macrophages with clodronate‐loaded liposomes reduced the size of NHO by 90%, supporting the conclusion that NHO is highly dependent on inflammation and phagocytic macrophages in soft tissues. Overall, we have developed the first clinically relevant model of NHO and demonstrated that a combined insult of neurological injury and soft tissue inflammation drives NHO pathophysiology. Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
When a child dies: pediatric oncologists' follow‐up practices with families after the death of their child
Authors: Granek Leeat , Barrera Maru , Scheinemann Katrin , Bartels Ute
Published: February 2015

Objectives

Follow‐up practices with bereaved families are considered a part of good medical care, yet little is known about pediatric oncologists' protocol with families when their patients die. The objective of this study was to examine follow‐up practices employed by pediatric oncologists after patient death using an in‐depth qualitative analysis.

Methods

The Grounded Theory method of data collection and analysis was used.

Twenty‐one pediatric oncologists at two Canadian pediatric hospitals were interviewed about their follow‐up practices with bereaved families after patients died. Line‐by‐line coding was used to establish codes and themes, and constant comparison was used to establish relationships among emerging codes and themes.

Results

Pediatric oncologists actively engage in follow‐up practices that include making phone calls, sending an email or condolence card, attending funerals or visitations, having long‐term and short‐term meetings with parents, and attending hospital or departmental memorials for the deceased child. Attending funerals or visitations was less frequent and varied widely across pediatric oncologists. Reasons for not participating in bereavement follow‐up practices included logistical, emotional, and practical considerations.

Conclusions

While the majority of pediatric oncologists at two Canadian centers engage in some follow‐up practices with bereaved families, these practices are complex and challenging because of the emotional nature of these interactions. Medical institutions should provide both structured time for this follow‐up work with families, as well as medical education and financial and emotional support to pediatric oncologists who continue caring for these families long after their child has died. Copyright © 2015 John Wiley & Sons, Ltd.
Meta‐analysis of diagnostic tests accounting for disease prevalence: a new model using trivariate copulas
Authors: Hoyer A. , Kuss O.
Published: February 2015

In real life and somewhat contrary to biostatistical textbook knowledge, sensitivity and specificity (and not only predictive values) of diagnostic tests can vary with the underlying prevalence of disease. In meta‐analysis of diagnostic studies, accounting for this fact naturally leads to a trivariate expansion of the traditional bivariate logistic regression model with random study effects. In this paper, a new model is proposed using trivariate copulas and beta‐binomial marginal distributions for sensitivity, specificity, and prevalence as an expansion of the bivariate model. Two different copulas are used, the trivariate Gaussian copula and a trivariate vine copula based on the bivariate Plackett copula. This model has a closed‐form likelihood, so standard software (e.g., SAS PROC NLMIXED) can be used. The results of a simulation study have shown that the copula models perform at least as good but frequently better than the standard model. The methods are illustrated by two examples. Copyright © 2015 John Wiley & Sons, Ltd.
Einwirkungskombinationen für Flachbodentanks nach Eurocode – Teil 1
Authors: Ball Peter
Published: February 2015

Aufgrund ihrer Konstruktionsweise stellen Flachbodentanks eine besondere Bauform mit komplexem Tragverhalten dar. Der Aufwand für bautechnische Standsicherheitsnachweise ist hierfür mit Einführung des Eurocodes teilweise weiter gestiegen. Zum einen ergeben sich neue, von der DIN 18800 abweichende Regeln für die Kombination von Lasten. Zum anderen sind nicht alle Punkte klar geregelt bzw. zwischen den einzelnen Normen abgestimmt. Dies führt sowohl bei Statikern und Herstellern als auch bei Betreibern mitunter zu erheblicher Unsicherheit. Im Folgenden werden die Regeln für Einwirkungskombinationen für Flachbodentanks mit dem Ziel diskutiert, eine einheitliche Anwendung und ein praxisgerechtes, allgemein abgestimmtes Vorgehen zu begleiten.

Load combinations for flat‐bottom storage tanks according to the Eurocode. Due to their design, flat‐bottom storage tanks are a special type of structure with complex loadbearing characteristics. With the introduction of the Eurocode, the requirements for the verification of stability have increased in some regards. On the one hand, there are new rules for the combination of loads that differ from DIN 18800. On the other hand, not all aspects are unambiguously defined within and across individual standards. This leads to significant uncertainty amongst structural engineers and manufacturers as well as operators. This article discusses the rules for load combinations for flat‐bottom storage tanks with the aim of facilitating a unified application and a practical, well‐coordinated approach.
Stabbogenbrücke im Zuge der Saale‐Elster‐Talbrücke – die schnellste im Netz der DB
Authors: Mansperger Tobias , Jung Rolf
Published: February 2015

Die Saale‐Elster‐Talbrücke ist Teil der zukünftigen Hochgeschwindigkeitsstrecke zwischen München und Berlin, die die Fahrzeit auf ca. vier Stunden verkürzen wird. Sie überquert die Auenlandschaft der Flüsse Saale und Elster südlich der Stadt Halle auf einer Gesamtlänge von 8,6 km und ist damit die längste Bahnbrücke Deutschlands. Einzigartig ist der Abzweig der Nebenstrecke auf der Brücke nach Halle.

Die Stabbogenbrücke befindet sich im Herzen des Brückenzuges als Überführungsbauwerk der Hauptstrecke über die Nebenstrecke. Mit ihrer exponierten Lage ist sie der optische sowie topografische Höhepunkt des Gesamtbauwerks. Die technischen Aspekte des Hochgeschwindigkeitsverkehrs machen die Stabbogenbrücke sogar zum Unikat, denn mit einer Entwurfsgeschwindigkeit von 300 km/h ist sie die erste Brücke dieser Bauart im Netz der Deutschen Bahn AG, was zu deutlich höheren Anforderungen im Rahmen des Planungs‐ und Genehmigungsprozesses führte. Dabei waren die dynamischen Beanspruchungen des Hochgeschwindigkeitsverkehrs und das ermüdungsarme Konstruieren der Schweißverbindungen besonders anspruchsvoll.

Der Rohbau der Brücke wurde im Sommer 2013 fertiggestellt, der Ausbau ein Jahr später. Seit September 2014 läuft der Probebetrieb, in dessen Rahmen ein ausführliches Messprogramm durchgeführt wird.

The tied arch bridge of the Saale‐Elster‐Viaduct – the fastest of its kind in the German railroad network. The Saale‐Elster‐Viaduct is part of the future high‐speed railway, connecting the cities of Munich and Berlin within a travel time of about four hours. It crosses the floodplain of the rivers Saale and Elster south of the city of Halle. With a total length of 8.6 kilometres, it is Germany’s longest railroad bridge and the branching off of the junction to Halle on the bridge is unique.

The tied arch bridge is located in the heart of the viaduct, where the main route surpasses the junction to Halle. With its exposed position it is the optical and technical highlight of the entire building. Furthermore it is the first tied arch bridge of the German railroad network with a design speed of 300 km/h, which led to increased approval efforts during the design process. The design was governed by the dynamic assessment of the high speed railway traffic, and fatigue resistant detailing of all connections.

The structure of the bridge was finished in summer 2013 and the installation of the tracks one year later. Since September 2014 an elaborate test phase including an extensive monitoring program is being performed.