bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermodynamic investigation of thermoresponsive xanthan‐poly (N‐isopropylacrylamide) hydrogels
Authors: Hamcerencu Mihaela , Desbrieres Jacques , Khoukh Abdel , Popa Marcel , Riess Gérard
Published: May 2011

Polysaccharide‐based hydrogels, such as xanthan maleate/poly(N‐isopropylacrylamide) (PNIPAAm) interpenetrated polymer networks, are thermostimulable materials of interest for the controlled release of biologically active components due to conformation changes at the low critical‐solution temperature (LCST) PNIPAAm phase transition. The phase transition of these interpenetrated polymer network hydrogels, where PNIPAAm is in a ‘confined’ environment, was examined by high resolution magic angle spinning nuclear magnetic resonance and differential scanning calorimetry. High resolution magic angle spinning nuclear magnetic resonance spectroscopy allows the accurate determination of LCST and an evaluation of the corresponding thermodynamic data. More particularly, the evolution of these data as a function of the composition of the hydrogel, and of the external parameters such as pH and ionic strength, was considered. LCST shows a minimal value with increasing xanthan content. Moreover, it was possible to calculate, as a function of temperature, the fraction of NIPAAm which remains uncollapsed. The data obtained for pure PNIPAAm hydrogels are in good agreement with recently published results. The phase transition of PNIPAAm in a diphasic hydrogel is broader when PNIPAAm is ‘confined’ within an interpenetrated polymer network than in a pure PNIPAAm crosslinked network. The widening of the transition with increasing xanthan content indicates a reduction of the PNIPAAm interchain aggregation in a network structure. Copyright © 2011 Society of Chemical Industry
The effect of the soft segment of prepolymers on properties of poly(urethane‐ester) and its biodegradability
Authors: Arcana I Made , Bundjali Bunbun , Hasan M , Zulfikar Muhamad Ali , Hariyawati Ketut
Published: May 2011

The influence of soft‐segment prepolymers prepared through the polymerization of δ‐valerolactone (VL) and 2,2‐dimethyl‐1,3‐propandiol (DP) monomers on the structure and properties of poly(urethane‐ester) as well as its biodegradability were investigated. Poly(urethane‐ester) was prepared in two steps. The first step was the preparation of prepolymers with various chain lengths by polymerizing VL and DP monomers in the presence of a distannoxane catalyst at 100 °C under nitrogen atmosphere. The second step was the preparation of poly(urethane‐ester) by polymerizing 4,4′‐methylene‐bis(phenyl isocyanate) (MDI) and prepolymers with various chain lengths in the absence of catalysts. The poly(urethane‐ester) was characterized through an analysis of functional groups (FTIR), thermal properties (differential thermal analysis/TGA), mechanical properties (tensile tester), crystallinity (XRD) and biodegradability. An increased chain length of the prepolymer used in polymerization with MDI leads to an increase in the thermal properties and crystallinity of poly(urethane‐ester). However, the maximum biodegradability in the activated sludge was observed in the poly(urethane‐ester) prepared by polymerizing MDI and prepolymers with a molar VL/DP ratio of 20/1. The amorphous parts of polymers were more easily decomposed by microorganism enzymes than were the crystalline parts after an incubation period of 30 days. Copyright © 2011 Society of Chemical Industry
ErbB2‐associated changes in the lysosomal proteome
Authors: Nylandsted Jesper , Becker Andrea C. , Bunkenborg Jakob , Andersen Jens S. , Dengjel Jörn , Jäättelä Marja
Published: May 2011

Late endosomes and lysosomes (hereafter referred to as lysosomes) play an essential role in the turnover of cellular macromolecules and organelles. Their biochemical characterization has so far depended on purification methods based on either density gradient centrifugations or magnetic purification of iron‐loaded organelles. Owing to dramatic changes in lysosomal density and stability associated with lysosomal diseases and cancer, these methods are not optimal for the comparison of normal and pathological lysosomes. Here, we introduce an efficient method for the purification of intact lysosomes by magnetic immunoprecipitation with antibodies against the vacuolar‐type H+‐ATPase. Quantitative MS‐based proteomics analysis of the obtained lysosomal membranes identified 60 proteins, most of which have previously been associated with the lysosomal compartment. Interestingly, the lysosomal membrane proteome was significantly altered by the ectopic expression of an active form of the ErbB2 oncogene, which renders the cells highly metastatic. The furthermost ErbB2‐associated changes included increased levels of CD63, S100A11 and ferritin heavy chain. Overall, our data introduce the antibody‐based purification of lysosomes as a suitable method for the characterization of lysosomes from a variety of pathological conditions with altered lysosomal density and stability.
Investigation of POPX2 phosphatase functions by comparative phosphoproteomic analysis
Authors: Singh Pritpal , Gan Chee Sian , Guo Tiannan , Phang Hui‐Qun , Sze Siu Kwan , Koh Cheng Gee
Published: May 2011

Identifying the substrates and biochemical pathway regulated by phosphatases has always been more challenging than finding those regulated by kinases. Here, we report the use of phosphoproteomic methods to analyse the pathways regulated by POPX2 (partner of PIX 2) phosphatase. POPX2 is a serine/threonine phosphatase, found in many cancer types. The levels of the POPX2 have been found to be up‐regulated in the more invasive breast cancer cells compared with non‐invasive ones. Our observations also suggest that POPX2 level is positively correlated with cell motility. Thus, finding substrates or pathways regulated by POPX2 will help to elucidate the regulatory mechanism of cancer cell motility and invasiveness. We have also developed and validated a protocol using electrostatic repulsion‐hydrophilic interaction chromatography (ERLIC) to enrich the phosphopeptides followed by LC‐MS/MS to allow comparison between the phosphoproteomes of control and POPX2 overexpressing cells. With this approach, we were able to identify a biochemical pathway through which POPX2 exerts its apparent cellular function: the regulation of activity of glycogen synthase kinase‐3, which in turn modulates extracellular signal‐regulated kinase and cell motility.
Comparison between procedures using SDS for shotgun proteomic analyses of complex samples
Authors: Bereman Michael S. , Egertson Jarrett D. , MacCoss Michael J.
Published: May 2011

Filter‐aided sample preparation (FASP) and a new sample preparation method using a modified commercial SDS removal spin column are quantitatively compared in terms of their performance for shotgun proteomic experiments in three complex proteomic samples: a Saccharomyces cerevisiae lysate (insoluble fraction), a Caenorhabditis elegans lysate (soluble fraction), and a human embryonic kidney cell line (HEK293T). The characteristics and total number of peptides and proteins identified are compared between the two procedures. The SDS spin column procedure affords a conservative fourfold improvement in throughput, is more reproducible, less expensive (i.e. requires less materials), and identifies between 30 and 107% more peptides at q≤0.01, than the FASP procedure. The peptides identified by SDS spin column are more hydrophobic than species identified by the FASP procedure as indicated by the distribution of GRAVY scores. Ultimately, these improvements correlate to as great as a 50% increase in protein identifications with two or more peptides.
Effects of postmortem storage temperature on sea bass (Dicentrarchus labrax) muscle protein degradation: Analysis by 2‐D DIGE and MS
Authors: Terova Genciana , Addis Maria Filippa , Preziosa Elena , Pisanu Salvatore , Pagnozzi Daniela , Biosa Grazia , Gornati Rosalba , Bernardini Giovanni , Roggio Tonina , Saroglia Marco
Published: May 2011

Storage conditions are known to be important for postmortem deterioration of fish muscle, and temperature is one of the factors with the strongest impact on this process. In order to shed light on the influence of temperature on the status of sea bass (Dicentrarchus labrax) muscle proteins during postmortem storage, a 2‐D DIGE and mass spectrometry study was performed on fish kept at either 1 or 18°C for 5 days. As expected, the greatest alterations in sea bass filet protein composition were observed upon postmortem storage at 18°C, with distinct changes appearing in the 2‐D protein profile after 5 days of storage at this temperature. In particular, degradation of the myofibrillar protein myosin heavy chain and of the glycolytic enzyme glyceraldehyde‐3‐phosphate dehydrogenase, among the most abundant muscle proteins, could be clearly observed upon storage at higher temperatures. Although to a lesser extent, however, several proteins were observed to vary in abundance also upon storage for 5 days at 1°C. In particular, one of the most interesting observations was the rapid and significant decrease in the abundance of nucleoside diphosphate kinase B and phosphoglycerate mutase 2, which was observed also at low storage temperatures and appeared to be temperature‐independent. The results of this study offer new knowledge on changes occurring in sea bass muscle proteins during postmortem storage at different temperatures and provide indications on protein degradation trends that might be useful for monitoring freshness of fish and quality of storage conditions.
Poly‐2‐oxazoline‐derived polyurethanes: A versatile synthetic approach to renewable polyurethane thermosets
Authors: Del Rio Enrique , Lligadas Gerard , Ronda Juan Carlos , Galià Marina , Cádiz Virginia
Published: May 2011

2‐Nonyl‐2‐oxazoline and 2‐(9‐decenyl)‐2‐oxazoline have been copolymerized in different proportions by cationic ring‐opening polymerization to obtain a series of random linear copolymers with tailored molecular weight and double bond functionality in the side chains. Thiol‐ene addition of 2‐mercaptoethanol has been used to produce a set of polyoxazoline–polyols under mild conditions and with quantitative double bond transformation. The polyols obtained in this way were reacted with methylene‐bis(phenylisocyanate) to yield a series of amorphous and semicrystalline polyurethane networks. The thermal stability and the thermomechanical properties of these thermosets have been studied and related with the structure of the parent polyols. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Synthesis and properties of novel triptycene‐based polyimides
Authors: Hsiao Sheng‐Huei , Wang Hui‐Min , Chen Wen‐Jeng , Lee Tzong‐Ming , Leu Chyi‐Ming
Published: May 2011

Two new triptycene‐containing bis(ether amine)s, 1,4‐bis(4‐aminophenoxy)triptycene (4) and 1,4‐bis(4‐amino‐2‐trifluoromethylphenoxy)triptycene (6), were synthesized, respectively, from the nucleophilic chloro‐displacement reactions of p‐chloronitrobenzene and 2‐chloro‐5‐nitrobenzotrifluoride with 1,4‐dihydroxytriptycene in the presence of potassium carbonate, followed by palladium‐catalyzed hydrazine reduction of the dinitro intermediates. The bis(ether amine)s were polymerized with six commercially available aromatic tetracarboxylic dianhydrides to obtain two series of novel triptycene‐based polyimides 8a–f and 9a–f by using a conventional two‐step synthetic method via thermal and chemical imidizations. All the resulting polyimides exhibited high enough molecular weights to permit the casting of flexible and strong films with good mechanical properties. Incorporation of trifluoromethyl groups in the polyimide backbones improves their solubility and decreases their dielectric constants. The fluorinated polyimides 9d and 9f derived from diamine 6 with 4,4′‐oxydiphthalic anhydride and 2,2‐bis(3,4‐dicarboxyphenyl)hexafluoropropane dianhydride (6FDA), respectively, could afford almost colorless thin films. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Theoretical study of spectroscopic properties of insulated molecular wires formed by substituted oligothiophenes and cross‐linked α‐cyclodextrin
Authors: Venâncio Mateus F. , Nascimento Clebio S. , Anconi Cleber P. A. , Lopes Juliana Fedoce , Rocha Willian R. , Dos Santos Hélio F. , De Almeida Wagner B.
Published: May 2011

The inclusion compound formed between cross‐linked α‐cyclodextrin dimer and substituted oligothiophene, was investigated using density functional theory (DFT). Energy gap, spectroscopy (IR, UV–vis, 13C NMR, and 1H NMR) and first hyperpolarizability data were analyzed for the free species and inclusion compound, pp‐PT@(αCD–αCD). The semiconducting property of the included pp‐PT was not substantially affected on inclusion, with the energy gap increasing by only 10% after interaction with αCD–αCD. On the other hand, the nonlinear optical (NLO) response was significantly decreased, with the first hyperpolarizability, β, predicted to be just more than 60% lower for the [2]rotaxane than for free pp‐PT, but still having considerable magnitude. This was explained by the two‐state model based on the charge‐transfer contribution to the electronic transitions. The sensitivity of electronic spectra might also be useful for the inclusion complex characterization. The IR spectrum was slightly sensitive to the host–guest interaction and the calculated 13C NMR and 1H NMR chemical shifts for the pp‐PT guest showed appreciable variations of 5–10 and 1–1.5 ppm, respectively, and so can be used for the characterization of inclusion compounds. We concluded that the formation of inclusion complexes with CDs, seems indeed very promising and the use of encapsulating conducting material should be experimentally pursued. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011
Backdoor opening mechanism in acetylcholinesterase based on X‐ray crystallography and molecular dynamics simulations
Authors: Sanson Benoît , Colletier Jacques‐Philippe , Xu Yechun , Lang P. Therese , Jiang Hualiang , Silman Israel , Sussman Joel L. , Weik Martin
Published: May 2011

The transient opening of a backdoor in the active‐site wall of acetylcholinesterase, one of nature's most rapid enzymes, has been suggested to contribute to the efficient traffic of substrates and products. A crystal structure of Torpedo californica acetylcholinesterase in complex with the peripheral‐site inhibitor aflatoxin is now presented, in which a tyrosine at the bottom of the active‐site gorge rotates to create a 3.4‐Å wide exit channel. Molecular dynamics simulations show that the opening can be further enlarged by movement of Trp84. The crystallographic and molecular dynamics simulation data thus point to the interface between Tyr442 and Trp84 as the key element of a backdoor, whose opening permits rapid clearance of catalysis products from the active site. Furthermore, the crystal structure presented provides a novel template for rational design of inhibitors and reactivators, including anti‐Alzheimer drugs and antidotes against organophosphate poisoning.
Increased high‐sensitivity c‐reactive protein predicts a high risk of lower urinary tract symptoms in chinese male: Results from the fangchenggang area male health and examination survey
Authors: Lu Zheng , Gao Yong , Tan Aihua , Yang Xiaobo , Zhang Haiying , Mo Linjian , Wu Chunlei , Hu Yanling , Mo Zengnan
Published: May 2011

BACKGROUND

Reports have shown that increased serum C‐reactive protein (CRP) suggests a risk of lower urinary tract symptoms (LUTS) in the West population. However, few studies have investigated the role of CRP as regards LUTS in a Chinese male population.

METHODS

Data were collected from 1,452 men who participated in the population‐based Fangchenggang Area Male Health and Examination Survey (FAMHES), which was carried out in Guangxi, China, from September 2009 to December 2009. In the current study, serum CRP was measured with a high‐sensitivity method (hsCRP) and LUTS was assessed by International Prostate Symptom Score (IPSS). Meanwhile, information about potential confounding variables (smoking, hypertension, diabetes, etc.) were included.

RESULTS

We observed that statistically significant distinction presented in the distribution of hsCRP levels and age between LUTS group and non‐LUTS group (P < 0.001). Comparing with the lowest hsCRP tertile, men with the highest hsCRP tertile were 1.72 times more likely to have overall LUTS and 1.93 times more likely to have irritative symptoms. As for individual symptoms of LUTS, statistically significant correlations were noted between serum hsCRP levels and urgency (OR = 1.74, 95% CI = 1.09–2.78) and nocturia (OR = 1.64, 95% CI = 1.18–2.27), when comparing them from the 1st to 3rd hsCRP tertiles. After multivariate adjusted, the results changed slightly and were still significant.

CONCLUSIONS

In a Chinese male population, we firstly confirmed a positive correlation of serum hsCRP with LUTS. It can be inferred that inflammation may be involved in the processes of LUTS. Prostate 72:193–200, 2012. © 2011 Wiley Periodicals, Inc.
Isoforms of the heteropteran Nezara viridula ecdysone receptor: protein characterisation, RH5992 insecticide binding and homology modelling
Authors: Tohidi‐Esfahani Donya , Lawrence Michael C , Graham Lloyd D , Hannan Garry N , Simpson Ann M , Hill Ronald J
Published: May 2011

BACKGROUND: Certain bisacylhydrazine compounds such as tebufenozide (RH5992) have been shown to act as order‐specific insecticides. Their compatibility with predatory Heteroptera, which are used as biological control agents, has also been demonstrated. However, the molecular mode of action of these ecdysone agonists has not been explored in a heteropteran, much less one that is a significant agricultural pest, such as Nezara viridula.

RESULTS: Alternatively spliced ligand‐binding regions of the N. viridula ecdysone receptor were expressed, purified and characterised by 2D gel analysis, mass spectrometry, homology modelling and competitive binding of a bisacylhydrazine insecticidal compound (RH5992) and various ecdysteroids. Ligand binding by the two splice isoforms was indistinguishable, and relative affinities were found to occur in the order muristerone A > ponasterone A > 20‐hydroxyecdysone > inokosterone > RH5992 > α‐ecdysone.

CONCLUSION: The predicted difference in amino acid sequence between the ligand‐binding domains of the N. viridula ecdysone receptor splice variants was verified by mass spectrometry. Both splice variant isoforms exhibit a greater affinity for the bisacylhydrazine insecticide RH5992 than do the other hemipteran ecdysone receptors characterised to date. Their affinities for a range of ecdysteroids also distinguish them from the ecdysone receptors of other Hemiptera characterised thus far. Homology models of both N. viridula receptor isoforms provide further insight into the bisacylhydrazine‐ and ecdysteroid‐binding properties of these receptors, including their similar affinity for 20‐hydroxyecdysone and the postulated pentatomomorphan moulting hormone makisterone A. Copyright © 2011 Society of Chemical Industry
Studies on the development of a mating disruption system to control the tomato leafminer, Tuta absoluta Povolny (Lepidoptera: Gelechiidae)
Authors: Vacas Sandra , Alfaro Cristina , Primo Jaime , Navarro‐Llopis Vicente
Published: May 2011

BACKGROUND: The tomato leafminer (Tuta absoluta Povolny) has rapidly colonised the whole Mediterranean and South‐Atlantic coasts of Spain, and it has become a key problem in both outdoor and greenhouse crops. New control methods compatible with biological control are required, and mating disruption appears to be a perfect method in current agriculture, as it is an environmentally friendly and residue‐free technique. IPM packages tested have included the use of pheromones to detect populations, but there has not been much previous research on mating disruption of T. absoluta. In this work, pheromone doses varying from 10 to 40 g ha−1, emitted at a constant rate over 4 months, were tested in greenhouses with different levels of containment in order to evaluate the efficacy of mating disruption on T. absoluta.

RESULTS: Trials on containment level revealed that the flight of T. absoluta was satisfactorily disrupted with an initial pheromone dose of 30 g ha−1, and levels of damage did not significantly differ from those in reference plots with insecticide treatments. Later efficacy trials confirmed previous experiences, and release studies showed that control of damage and flight disruption were taking place when releasing at least 85 mg pheromone per ha per day.

CONCLUSION: Effective control using pheromone application against T. absoluta can be achieved, in greenhouses with high containment levels, for 4 months, with initial doses of 30 g ha−1. Further research must be conducted in order to evaluate the prospect of outdoor application of mating disruption systems. Copyright © 2011 Society of Chemical Industry
Managing viral infections in pregnancy and the puerperium
Authors: Ugwumadu Austin
Published: May 2011

Our series Prescribing in pregnancy provides guidance on what information to offer pregnant women about the risks and benefits of drug treatment. Here the author outlines the management of common viral infections in pregnancy. Copyright © 2011 Wiley Interface Ltd
My views on prescribing safety, licensing and the drug industry
Authors: Herxheimer Andrew
Published: May 2011

What former DTB editor and now UK Cochrane Centre Emeritus Fellow Andrew Herxheimer thinks about prescribing safety, drug licensing and the pharma industry. Copyright © 2011 Wiley Interface Ltd
Roflumilast (Daxas): a novel approach to treating COPD
Authors: Small Iain
Published: May 2011

Roflumilast (Daxas) is the first in a new class of treatment for COPD that targets the underlying inflammation. In our New products review, Dr Iain Small presents the clinical trial evidence for its efficacy and side‐effects and discusses its place in COPD management. Copyright © 2011 Wiley Interface Ltd
URTIs: recommended diagnosis and treatment in general practice
Authors: Barton Edward , Spencer Robert
Published: May 2011

Upper respiratory tract infections collectively encompass a range of syndromes with various aetiologies. Our Drug review considers the common URTIs and their diagnosis and management, including when to prescribe antibiotics, followed by sources of further information in Resources. Copyright © 2011 Wiley Interface Ltd
Oral contraception: the pros and cons of COCs and POPs
Authors: MacGregor Anne
Published: May 2011

Oral contraceptives are effective, reversible, independent of intercourse and for the majority of users safe with added health benefits. Our Drug review considers the properties and efficacy of both combined and progestogen‐only pills, followed by sources of further information and an analysis of the prescription data. Copyright © 2011 Wiley Interface Ltd
DPP‐4 inhibitors: their properties and place in treatment
Authors: Chaplin Steve , Campbell Ian
Published: May 2011

Steve Chaplin and Professor Ian Campbell provide an overview of the indications and properties of DPP‐4 inhibitors and their current recommended place in treating type 2 diabetes. Copyright © 2011 Wiley Interface Ltd
Methadone and buprenorphine as opiate substitution therapy
Authors: Lawson Euan
Published: May 2011

The author describes how to prescribe methadone and buprenorphine safely and effectively as part of a maintenance programme in opiate substitution therapy. Copyright © 2011 Wiley Interface Ltd
Lamotrigine to prevent depressive episodes in bipolar disorder
Authors: Saunders Kate , Goodwin Guy
Published: May 2011

Lamotrigine is now indicated for the prevention of depression in bipolar disorder. Here, Dr Kate Saunders and Professor Guy Goodwin describe its efficacy, side‐effects and drug interactions in a condition where antidepressants have limited use. Copyright © 2011 Wiley Interface Ltd
Cleaning and growth morphology of GaN and InGaN surfaces
Authors: Falta J. , Schmidt Th. , Gangopadhyay S. , Schulz Chr. , Kuhr S. , Berner N. , Flege J. I. , Pretorius A. , Rosenauer A. , Sebald K. , Lohmeyer H. , Gutowski J. , Figge S. , Yamaguchi T. , Hommel D.
Published: May 2011

The structure and chemistry of clean GaN surfaces and InGaN thin films and nanostructures grown by metal organic vapour pressure epitaxy (MOVPE) has been studied by means of X‐ray photoemission spectroscopy, low‐energy electron diffraction as well as scanning tunneling microscopy (STM) and transmission electron microscopy. Thermal annealing strongly improves the cleanliness of samples after dry nitrogen transfer and related exposure to residual oxygen. Nitrogen plasma assisted cleaning is shown to successfully further remove carbon contaminations, while Ga deposition with subsequent desorption to is shown to be superior for an enhanced reduction of surface oxygen. Using STM, the surface morphology has been studied in dependence on major growth parameters at various stages of InGaN MOVPE growth. The formation of nano‐islands is reported for different growth conditions. By means of micro‐photoluminescence measurements, we find samples to show strong photoluminescence from quantum‐dot‐like structures, however, the corresponding growth front is found to be rather flat throughout InGaN deposition. This leads to the conclusion that the formation of quantum dots does not proceed in a Stranski–Krastanov‐like fashion but most likely during overgrowth.

magnified image

Scanning tunneling micrograph and height profile of 3.9 nm InGaN grown by MOVPE at 700 °C, after growth interruption and 1 min post‐growth annealing at the growth temperature. The surface exhibits a two‐dimensional islands morphology.
The vortex lattice in type‐II superconductors: Ideal or distorted, in bulk and films
Authors: Brandt Ernst Helmut
Published: May 2011

Abrikosov's solution of the linearized Ginzburg–Landau theory describes a periodic lattice of vortex lines in type‐II superconductors at large inductions. This solution is generalized to non‐periodic vortex arrangements, e.g., to lattices with a vacancy surrounded by relaxing vortex lattice and to periodically distorted lattices that appear in the nonlocal theory of elasticity of the vortex lattice. Generalizations to lower magnetic inductions and to three‐dimensional arrangements of curved vortex lines are also given. It is shown how the periodic vortex lattice can be computed for bulk superconductors as well as for thick and thin films in a perpendicular field for all Ginzburg–Landau parameters κ and all inductions ${\bar {B}}$.
Thermoelectric materials – Compromising between high efficiency and materials abundance
Authors: Homm G. , Klar P. J.
Published: May 2011

In the context of CO2 neutral and regenerative energy production, the field of thermoelectrics has shifted more and more into the focus of scientific research in the last few years. Particularly a lot of research projects were started in the field of energy autarkic sensor technology and the so called energy harvesting, i.e. the recycling of otherwise lost energy. A potentially huge industrial branch for thermoelectric applications is the automotive industry with a main emphasis on generating electricity out of the waste heat of combustion engines with the help of thermoelectric generators or using Peltier cooling to replace conventional air conditioning in the passenger compartment. In addition, many niche applications are possible, e.g. as sensors for measuring the air pressure of tires etc. The applications of thermoelectric devices are very versatile. We analyse the potential of the state‐of‐the‐art thermoelectric materials SiGe, PbTe, Bi2Te3, FeSi2 and potentially ZnO with respect to employment in four types of applications, classified by mobile vs stationary and specialized vs. mass application. The selection criteria comprise efficiency, materials availability, costs, environmental friendliness and toxicity. Based on these criteria, a decision matrix for choosing the appropriate material system for a specific application is defined. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spectroscopic constants and molecular properties of A3Σu+, B3Πg, W3Δu, and B′3Σu− electronic states of the N2 molecule
Authors: Shi De‐Heng , Xing Wei , Sun Jin‐Feng , Zhu Zun‐Lue , Liu Yu‐Fang
Published: May 2011

The potential energy curves (PECs) of A3Σ, B3Πg, W3Δu, and B′3Σ electronic states of the N2 molecule have been studied for internuclear separations from 0.05 to 2.0 nm using the full valence complete active space self‐consistent‐field method followed by the highly accurate valence internally contracted multireference configuration interaction (MRCI) approach in conjunction with the correlation‐consistent basis sets. Effects on the PECs by the core–valence correlation and relativistic corrections are taken into account. The way to consider the relativistic correction is to use the second‐order Douglas‐Kroll Hamiltonian approximation. The core–valence correlation correction is made with the cc‐pCV5Z basis set. And the relativistic correction is performed at the level of cc‐pV5Z basis set. To obtain more reliable results, the PECs determined by the MRCI calculations are also corrected for size‐extensivity errors by the Davidson modification (MRCI+Q). These PECs are extrapolated to the complete basis set limit. The spectroscopic parameters of 14N2, 14N15N, and 15N2 isotopologs have been evaluated and compared with those reported in the literature. Excellent agreement has been found between the present results and the Rydberg‐Klein‐Rees (RKR) data. With the PECs obtained by the MRCI+Q/CV+DK+56 calculations, the first 30 vibrational states for three species are computed for each electronic state. And for each electronic state of each species, the vibrational level G(ν), inertial rotation constant Bν, and centrifugal distortion constant Dν have been determined, which agree well with the RKR data. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012
REMOVAL OF WEIRS AND THE INFLUENCE ON PHYSICAL HABITAT FOR SALMONIDS IN A NORWEGIAN RIVER
Authors: Fjeldstad H.‐P. , Barlaup B. T. , Stickler M. , Gabrielsen S.‐E. , Alfredsen K.
Published: May 2011

In the late 1970s, the construction of weirs in Norwegian regulated river systems for aesthetic reasons was common. However, today, the focus of river restoration has shifted towards improving biological functionality and biodiversity. In the present study, two weirs, originally built to create a stable water level, were removed on a residual flow reach in a Norwegian regulated river as a measure to restore river connectivity and to re‐establish the local population of Atlantic salmon. The removal design was based on hydraulic modelling, and biological monitoring was implemented before and after the weir removal to evaluate the biological response to weir removal. The results demonstrated that salmon spawning sites were recreated in the old bed substratum and were occupied immediately the first season after weir removal, when water velocities increased to more suitable levels for spawning. Accordingly, mortality of Atlantic salmon eggs was reduced and the densities of juveniles showed a marked increase after weir removal. Conversely, pike and cyprinids in the reach were found in the samples before weir removal but not after removal, indicating that the desired shift in fish community in response to habitat alteration was obtained. Furthermore, enumeration of migrating adult salmon at a fishway upstream of the study reach showed that the migration peak, on average, was 1 month earlier in the 3 years after removal as compared with the 5 years before removal. Finally, the use of hydraulic modelling represented a useful method for designing physical habitat adjustments and assessing their influence on fish biology. The model results also supported a rapid process in planning and execution of construction works. Copyright © 2011 John Wiley & Sons, Ltd.
Earth systems science: An analytic framework
Authors: Finley Fred N. , Nam Younkeyong , Oughton John
Published: May 2011

Earth Systems Science (ESS) is emerging rapidly as a discipline and is being used to replace the older earth science education that has been taught as unrelated disciplines—geology, meteorology, astronomy, and oceanography. ESS is complex and is based on the idea that the earth can be understood as a set of interacting natural and social systems. An analytic, metalevel framework is needed to understand the complexity. The framework specifies a set of metalevel essential ideas and analytic concepts that can be applied to understand the substantive structures of ESS—the essential ideas describe the general nature of earth systems, and the analytic concepts describe types of discipline‐specific concepts such as the materials, processes, and variables of earth systems. An analysis for the phenomenon of carbon cycling is provided as an example. The framework allows one to determine whether what is to be taught is complete and coherent and can be used to conduct research and evaluations of curriculum, teachers' knowledge, and students' knowledge in a systematic manner. Sets of studies completed using the ESS analytic framework will allow comparability across subjects that is currently lacking. © 2011 Wiley Periodicals, Inc. Sci Ed 95:1066–1085, 2011
Privacy‐preserving frequent itemsets mining via secure collaborative framework
Authors: Wong Kok Seng , Kim Myung Ho
Published: May 2011

Knowledge‐discovering or pattern‐discovering process, such as data mining, is an important technique to discover hidden but useful information from a large volume of data. Under distributed environment, data mining task has become a challenging task due to data protection and privacy concerns. The secure multi‐party computation (SMC) approach has been widely used to solve privacy‐preserving data mining problems. However, generic SMC solutions are not practical from an efficiency point of view, especially when the number of parties and the size of the data are large. In view of these problems, we utilize a secure collaborative framework to facilitate the computation protocol for SMC. In this paper, we particularly consider the problem of privacy‐preserving frequent itemsets mining under distributed environment. Our solution reduces the risk for central data mining and improves the efficiency of the current generic SMC solutions. Furthermore, our solution is more reliable and flexible regardless of the number of parties involved. Copyright © 2011 John Wiley & Sons, Ltd.
Fitting dynamic models with forcing functions: Application to continuous glucose monitoring in insulin therapy
Authors: Lunn, D. J. , Wei C. , Hovorka R.
Published: May 2011

The artificial pancreas is an emerging technology to treat type 1 diabetes (T1D). It has the potential to revolutionize diabetes care and improve quality of life. The system requires extensive testing, however, to ensure that it is both effective and safe. Clinical studies are resource demanding and so a principle aim is to develop an in silico population of subjects with T1D on which to conduct pre‐clinical testing. This paper aims to reliably characterize the relationship between blood glucose and glucose measured by subcutaneous sensor as a major step towards this goal. Blood‐and sensor‐glucose are related through a dynamic model, specified in terms of differential equations. Such models can present special challenges for statistical inference, however. In this paper we make use of the BUGS software, which can accommodate a limited class of dynamic models, and it is in this context that we discuss such challenges. For example, we show how dynamic models involving forcing functions can be accommodated. To account for fluctuations away from the dynamic model that are apparent in the observed data, we assume an autoregressive structure for the residual error model. This leads to some identifiability issues but gives very good predictions of virtual data. Our approach is pragmatic and we propose a method to mitigate the consequences of such identifiability issues. Copyright © 2011 John Wiley & Sons, Ltd.
Marginal regression models with time‐varying coefficients for recurrent event data
Authors: Sun Liuquan , Zhou Xian , Guo Shaojun
Published: May 2011

Recurrent event data arise frequently from medical research. Examples include repeated infections, recurrence of tumors, relapse of leukemia, repeated hospitalizations, recurrence of symptoms of a disease, and so on. In the analysis of recurrent event data, the proportional rates model assumes that the regression coefficients are time invariant. In reality, however, these parameters may vary over time, and the temporal covariate effects on the event process are of great interest. In this article, we formulate a class of semiparametric marginal rates models, which incorporate a mixture of time‐varying and time‐independent parameters, to analyze recurrent event data. For statistical inference on model parameters, an estimation procedure is developed and asymptotic properties of the proposed estimators are established. In addition, we develop tests for investigating whether or not covariate effects vary with time. The finite‐sample behaviors of the proposed methods are examined in simulation studies. An example of application of the proposed methodology is illustrated on a set of data from a clinic study on chronic granulomatous disease. Copyright © 2011 John Wiley & Sons, Ltd.
Bayesian procedures for phase I/II clinical trials investigating the safety and efficacy of drug combinations
Authors: Whitehead John , Thygesen Helene , Whitehead Anne
Published: May 2011

Many formal statistical procedures for phase I dose‐finding studies have been proposed. Most concern a single novel agent available at a number of doses and administered to subjects participating in a single treatment period and returning a single binary indicator of toxicity. Such a structure is common when evaluating cytotoxic drugs for cancer. This paper concerns studies of combinations of two agents, both available at several doses. Subjects participate in one treatment period and provide two binary responses: one an indicator of benefit and the other of harm. The word ‘benefit’ is used loosely here: the response might be an early indicator of physiological change which, if induced in patients, is of potential therapeutic value. The context need not be oncology, but might be any study intended to meet both the phase I aim of establishing which doses are safe and the phase II goal of exploring potential therapeutic activity. A Bayesian approach is used based on an assumption of monotonicity in the relationship between the strength of the dose‐combination and the distribution of the bivariate outcome. Special cases are described, and the procedure is evaluated using simulation. The parameters that define the model have immediate and simple interpretation. Graphical representations of the posterior opinions about model parameters are shown, and these can be used to inform the discussions of the trial safety committee. Copyright © 2011 John Wiley & Sons, Ltd.
Vital significance of addition of “shape similarity” between solutes to shape complementarity for more precise molecular recognition in aqueous binary solvents
Authors: Endo Tadashi
Published: May 2011

Precise and specific molecular recognition is vital to living systems. Discrimination has mainly been studied by using particular host molecules (e.g., crown ethers, cyclodextrin and urea derivatives). Several studies in various fields have pointed out that the famous “lock‐and‐key theory” (the concept of shape complementarity) is, at present, insufficient for understanding precise discrimination. This seems to come from the fact that various types of intermolecular interactions are decisive in such discrimination. This Review intends to describe the novel concept that “shape similarity” between interacting solutes should be added to “shape complementarity” for more precise discrimination to be achieved. Further, the role of shape similarity between solvent and solute molecules is also described. In relation to precise molecular recognition, weak interactions, which depend on the three‐dimensional shape of substituents (shape‐specific weak interactions), are described. Possibility of alterations in solvent structures is discussed in aqueous binary solvents. DOI 10.1002/tcr.201100001
Binocular rivalry: competition and inhibition in visual perception
Authors: Alais David
Published: May 2011

When the brain is presented with ambiguous visual stimuli supporting two interpretations, perception becomes bistable and alternates over time between one interpretation and the other. This process contains elements of competition (between the rivaling percepts) as well as inhibition, as the percepts are mutually exclusive so that one is always suppressed. This review covers the most widely studied form of bistable perception—binocular rivalry. Suppression in rivalry is covered in detail, including discussion of its general and specific components, its local nature and spatial organization, techniques for quantifying it, and the role of global feedback. The competitive dynamics of rivalry are discussed within the context of the classical ‘adapting reciprocal inhibition’ model of rivalry and recent evidence supporting this model is discussed. This model is contrasted with alternative models based on late competition and with hybrid models. Finally, the role of attention in rivalry is examined and commonalities with other forms of bistable perception are noted. WIREs Cogn Sci 2012, 3:87–103. doi: 10.1002/wcs.151

This article is categorized under:

Psychology > Attention
Barrett’s Esophagus After Resection of the Gastroesophageal Junction: Effects of Concomitant Fundoplication
Authors: Tsiouris Athanasios , Hammoud Zane , Velanovich Vic
Published: May 2011

Background

Barrett’s metaplasia has been known to occur after esophagectomy or gastrectomy in which the gastroesophageal junction with its associated lower esophageal sphincter has been resected. It is thought to be secondary to the refluxogenic nature of the operation. The present study was based on the hypothesis that patients who undergo a fundoplication with the resection would have a lower incidence of the development of postoperative Barrett’s metaplasia.

Methods

All patients who underwent any type of esophagectomy or proximal gastrectomy in which the gastroesophageal junction was resected and an esophagogastrostomy performed were eligible for the study. Data gathered included age, gender, preoperative diagnosis, operation, postoperative pathology, occurrence and timing of postoperative upper endoscopy, and presence of Barrett’s metaplasia on postoperative endoscopy. Statistical analysis was done with Fisher’s exact test.

Results

Of the 179 patients who underwent resection, 151 had follow‐up endoscopy documenting the presence or absence of Barrett’s esophagus. Follow‐up ranged from 6 months to 10 years. Of the 53 patients without fundoplications, 8 (18%) had Barrett’s esophagus on follow‐up upper endoscopy. Of the 98 patients with fundoplications, 5 (6%) had Barrett’s esophagus (P = 0.04).

Conclusions

The present study suggests that concomitant fundoplication with resection of the gastroesophageal junction may have some protective effect against the development of Barrett’s esophagus. A randomized trial will be required to prove this assertion. Also, it is still unclear as to the consequences of the development of post‐resection Barrett’s esophagus.
Persisting ratio of total amylase output in drain fluid can predict postoperative clinical pancreatic fistula
Authors: Okano Keiichi , Kakinoki Keitaro , Suto Hironobu , Oshima Minoru , Kashiwagi Hirotaka , Yamamoto Naoki , Akamoto Shintaro , Fujiwara Masao , Takama Takehiro , Usuki Hisashi , Hagiike Masanobu , Suzuki Yasuyuki
Published: May 2011

Background/purpose

A consistent predictor for pancreatic fistula (PF) development in the early period after pancreatic resection is still lacking.

Patients and methods

A total of 54 consecutive patients undergoing pancreatic resection were enrolled between June 2007 and April 2010. Pancreaticoduodenectomy (PD) and distal pancreatectomy (DP) were performed in 38 and 16 patients, respectively. For the purpose of finding an early predictor for PF development, we investigated drain amylase levels (d‐Amy, IU/mL), drain output volume (d‐Vol, mL/day) and drain amylase output (Amy‐V, IU/day) on postoperative days (POD) 1 and 3. Amy‐V was calculated as the product of d‐Amy and d‐Vol, and was expressed as the sum of values obtained from all drains. In addition, the ratio of d‐Amy or Amy‐V on POD3 to that on POD1 was calculated as the persisting ratio in each patient.

Results

The overall incidence of clinical PF (International Study Group on Pancreatic Fistula Grade B and C) was 16.7%, occurring in 13.1% after PD and 25% after DP. All PF occurred in cases with a remnant pancreas of soft texture. There was no significant difference in d‐Amy, d‐Vol, or Amy‐V on POD1 and POD3 between patients with and without clinical PF. The persisting ratio of Amy‐V was significantly lower in patients without clinical PF compared to those with clinical PF (p = 0.029). Furthermore, the persisting ratio of Amy‐V was significantly lower in patients with Grade A PF compared to those with Grade B PF (p = 0.03).

Conclusion

The persisting ratio of drain amylase output is a new significant predictive factor for clinical PF development.
Buddhist Literature and Progressive Thinking in Late Qing and Early Republican China
Authors: Guilin TAN
Published: May 2011

Buddhist literature in late Qing and early Republican China contributed to the new thinking in modern Chinese literature in a number of ways. Writers of Chinese Buddhist literature strove to elucidate the similarities between Buddhist culture and the scientific spirit, or to reveal the scientific spirit in Buddhist culture. Buddhist writers were aware of the importance of the spiritual enlightenment and mental reconstruction of the people, and realized the impact that literature and art as a kind of social ideology had on the national spirit. They were also interested in folk genres and vernacular literature. The May Fourth Movement put its emphasis on the people, while Buddhist literature in this period emphasized the related concept of humanity.
One Poet, Four Faces: The Invention of Tu Fu in Modern Chinese Poetry
Authors: Songjian ZHANG
Published: May 2011

As one of the greatest writers in ancient China, Tu Fu has exerted immense influence upon subsequent poets, including those living in the modern era. Combining history and text with theory, this essay intends to make an in-depth exploration of the rewriting of Tu Fu by Feng Zhi, Yang Mu, Xi Chuan, and Liu Waitong. First, I contextualize the selected four poems composed in 1941, 1974, 1989, and 2000, respectively; and then do a close reading of them. By doing so, this essay aims to observe the tensions between historical narrative and literary imagination, and between symbolic metaphor and living world, so as, ultimately, to interpret how the factors of aesthetics, politics, and metaphysics shaped the different images of Tu Fu.
Differences between Northern and Southern Dialects in Chinese Literature: The Example of Shanghai Writers
Authors: Yuanbao GAO
Published: May 2011

With the promotion of standard Chinese in China, dialects are becoming less and less important or even extinct. However, in Shanghai where the economy is developing very fast, the relationship between the dialect and standard Chinese in the field of literature seems returned to the original state at the beginning of modern Chinese literature. With the development of contemporary and modern Chinese literature as a context and Shanghai writers as an example, this paper will analyze the great influence of standard Chinese and dialects on contemporary and modern Chinese literature, the different manifestation between Northern and Southern areas, and the complicated reasons of this phenomenon.