bluuebunny/crossref_metadata_2025 huggingface dataset:
Long‐term in vitro hydrolytic stability of thermoplastic polyurethanes
Authors: Mishra Abhinay , Seethamraju Kasyap , Delaney Joseph , Willoughby Patrick , Faust Rudolf
Published: June 2015

Long‐term in vitro stability of thermoplastic polyurethanes (TPUs) was studied for up to 52 weeks in phosphate buffer solution at 37, 55, and 80°C. Water uptake, molecular weights, and tensile properties were measured at regular intervals of 4, 8, 16, 32, and 52 weeks. The rate of molecular weight reduction increased with increasing temperature, and after 52 weeks at 80°C, all commercial polycarbonate (Bionate‐55D, Quadrathane‐80A, and Chronoflex‐80A), poly(dimethylsiloxane) (ElastEon‐2A) and polyether (Elasthane‐55D) TPUs showed significant (43–51%) molecular weight (Mn) reduction. The polyisobutylene (PIB)‐based TPU exhibited a significantly lower decrease in Mn (26%) after 52 weeks at 80°C. For Bionate‐55D and ElastEon‐2A, at 80°C in dry nitrogen atmosphere substantial thermal degradation was observed, while for the other TPUs the effect of thermal degradation is small. The temperature dependent reduction of molecular weight was interpreted by simple second order kinetics. From the approximately linear Arrhenius plots the activation energies were calculated, which were highest for PIB‐PU‐020 and lowest for ElastEon‐2A. For Elasthane‐55D the in vitro molecular weight reduction was compared with that of explanted leads. The molecular weight reduction in vivo was much smaller than that predicted from in vitro data, which may suggest that the in vitro model does not adequately describe the hydrolysis in vivo. In the absence of validation for the other TPUs that in vitro methods closely reproduce in vivo degradation, it is unknown how these results correlate with in vivo performance. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 103A: 3798–3806, 2015.
Three‐dimensional printed PCL‐hydroxyapatite scaffolds filled with CNTs for bone cell growth stimulation
Authors: Gonçalves Elsa M. , Oliveira Filipe J. , Silva Rui F. , Neto Miguel A. , Fernandes M. Helena , Amaral Margarida , Vallet‐Regí María , Vila Mercedes
Published: June 2015

A three‐phase [nanocrystalline hydroxyapatite (HA), carbon nanotubes (CNT), mixed in a polymeric matrix of polycaprolactone (PCL)] composite scaffold produced by 3D printing is presented. The CNT content varied between 0 and 10 wt % in a 50 wt % PCL matrix, with HA being the balance. With the combination of three well‐known materials, these scaffolds aimed at bringing together the properties of all into a unique material to be used in tissue engineering as support for cell growth. The 3D printing technique allows producing composite scaffolds having an interconnected network of square pores in the range of 450–700 μm. The 2 wt % CNT scaffold offers the best combination of mechanical behaviour and electrical conductivity. Its compressive strength of ∼4 MPa is compatible with the trabecular bone. The composites show typical hydroxyapatite bioactivity, good cell adhesion and spreading at the scaffolds surface, this combination of properties indicating that the produced 3D, three‐phase, scaffolds are promising materials in the field of bone regenerative medicine. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1210–1219, 2016.
Accelerated molecular dynamics simulations of protein folding
Authors: Miao Yinglong , Feixas Ferran , Eun Changsun , McCammon J. Andrew
Published: June 2015

Folding of four fast‐folding proteins, including chignolin, Trp‐cage, villin headpiece and WW domain, was simulated via accelerated molecular dynamics (aMD). In comparison with hundred‐of‐microsecond timescale conventional molecular dynamics (cMD) simulations performed on the Anton supercomputer, aMD captured complete folding of the four proteins in significantly shorter simulation time. The folded protein conformations were found within 0.2–2.1 Å of the native NMR or X‐ray crystal structures. Free energy profiles calculated through improved reweighting of the aMD simulations using cumulant expansion to the second‐order are in good agreement with those obtained from cMD simulations. This allows us to identify distinct conformational states (e.g., unfolded and intermediate) other than the native structure and the protein folding energy barriers. Detailed analysis of protein secondary structures and local key residue interactions provided important insights into the protein folding pathways. Furthermore, the selections of force fields and aMD simulation parameters are discussed in detail. Our work shows usefulness and accuracy of aMD in studying protein folding, providing basic references in using aMD in future protein‐folding studies. © 2015 Wiley Periodicals, Inc.
Enzyme‐ and transporter‐mediated beverage–drug interactions: An update on fruit juices and green tea
Authors: An Guohua , Mukker Jatinder Kaur , Derendorf Hartmut , Frye Reginald F.
Published: June 2015

Beverage–drug interactions have remained an active area of research and have been the subject of extensive investigations in the past 2 decades. The known mechanisms of clinically relevant beverage–drug interactions include modulation of the activity of cytochrome P450 (CYP) 3A and organic anion‐transporting polypeptide (OATP). For CYP3A‐mediated beverage–drug interaction, the in vivo CYP3A inhibitory effect is limited to grapefruit juice (GFJ), which increases the bioavailability of several orally administered drugs that undergo extensive first‐pass metabolism via enteric CYP3A. In contrast, clinically significant OATP‐mediated beverage–drug interactions have been observed with not only GFJ but also orange juice, apple juice, and, most recently, green tea. Fruit juices and green tea are all a mixture of a large number of constituents. The investigation of specific constituent(s) responsible for the enzyme and/or transporter inhibition remains an active area of research, and many new findings have been obtained on this subject in the past several years. This review highlights the multiple mechanisms through which beverages can alter drug disposition and provides an update on the new findings of beverage–drug interactions, with a focus on fruit juices and green tea.
Food effects on abiraterone pharmacokinetics in healthy subjects and patients with metastatic castration‐resistant prostate cancer
Authors: Chi Kim N. , Spratlin Jennifer , Kollmannsberger Christian , North Scott , Pankras Catherine , Gonzalez Martha , Bernard Apexa , Stieltjes Hans , Peng Lixian , Jiao James , Acharya Milin , Kheoh Thian , Griffin Thomas W. , Yu Margaret K. , Chien Caly , Tran Nam Phuong
Published: June 2015

Food effect on abiraterone pharmacokinetics and safety on abiraterone acetate coadministration with low‐fat or high‐fat meals was examined in healthy subjects and metastatic castration‐resistant prostate cancer (mCRPC) patients. Healthy subjects (n = 36) were randomized to abiraterone acetate (single dose, 1000 mg) + low‐fat meal, + high‐fat meal, and fasted state. mCRPC patients received repeated doses (abiraterone acetate 1000 mg + 5 mg prednisone twice daily; days 1–7) in a modified fasting state followed by abiraterone acetate plus prednisone within 0.5 hours post–low‐fat (n = 6) or high‐fat meal (n = 18; days 8–14). In healthy subjects, geometric mean (GM) abiraterone area under plasma concentration–time curve (AUC) increased ∼5‐ and ∼10‐fold, respectively, with low‐fat and high‐fat meals versus fasted state (GM [coefficient of variation], 1942 [48] and 4077 [37] ng · h/mL vs 421 [67] ng · h/mL, respectively). In mCRPC patients, abiraterone AUC was ∼2‐fold higher with a high‐fat meal and similar with a low‐fat meal versus modified fasting state (GM [coefficient of variation]: 1992 [34] vs 973 [58] ng · h/mL and 1264 [65] vs 1185 [90] ng · h/mL, respectively). Adverse events (all grade ≤ 3) were similar, with high‐fat/low‐fat meals or fasted/modified fasting state. Short‐term dosing with food did not alter abiraterone acetate safety.
Efficient Synthesis, Characterization, In Vitro Antibacterial and Antifungal Activity Study and Computational Tool for Prediction of Molecular Properties of Some Novel Schiff's Base via Betti's Protocol and Azetidinones
Authors: Chopde Himani N. , Meshram Jyotsna S. , Pandhurnekar Chandrashekhar P. , Pagadala Ramakanth , Jonnalagadda Sreekantha Babu
Published: June 2015

Series of new substituted pyrazolone derivatives via Betti's condensation reaction of pyrazolone and different aldehydes has been reported successfully under ambient reaction conditions. The structural elucidation of newly synthesized compounds was done using analytical and spectroscopic tools such as elemental analysis, 1H NMR, 13C NMR, and mass spectroscopy. Physicochemical parameters, toxicity profiles and drug likeness properties were studied using various bioinformaticals tools like Osiris and molinspiration. These results viz., the good correlations between the inhibitory activities and the computational values make the molecules available for future protein–ligand interaction studies. It further provided useful information in understanding the structural and chemical features of the drug in designing and finding new potential inhibitors.
Synthesis of Novel 1H‐Imidazol[1,2‐a]Indeno[2,1‐e]Pyridine‐6(5H)‐Ones Derivatives via a One‐Pot Four‐Component Condensation Reaction
Authors: Mohammadi Ali A. , Taheri Salman , Amouzegar Ali
Published: June 2015

1H‐imidazol[1,2‐a]indeno[2,1‐e]pyridine‐6(5H)‐ones derivatives were synthesized in a one‐pot four‐component condensation of corresponding aldehydes, 1,3‐indandione, diamine, and nitro ketene dithioacetal using KAl(SO4)2·12H2O (alum) as nontoxic, reusable, inexpensive and easily available catalyst in good to excellent yields. This green protocol provides a powerful entry into fused polycyclic structures related to bioactive heterocycles.
Mobile Phones and Education in Sub‐Saharan Africa: From Youth Practice to Public Policy
Authors: Porter Gina , Hampshire Kate , Milner James , Munthali Alister , Robson Elsbeth , de Lannoy Ariane , Bango Andisiwe , Gunguluza Nwabisa , Mashiri Mac , Tanle Augustine , Abane Albert
Published: June 2015

Young people's use of mobile phones is expanding exponentially across Africa. Its transformative potential is exciting, but findings presented in this paper indicate how the downside of mobile phone use in African schools is becoming increasingly apparent. Drawing on mixed‐methods field research in 24 sites across Ghana, Malawi and South Africa and associated discussions with educational institutions, public policy makers and network providers, we examine the current state of play and offer suggestions towards a more satisfactory alignment of practice and policy which promotes the more positive aspects of phone use in educational contexts and militates against more damaging ones. © 2015 The Authors. Journal of International Development published by John Wiley & Sons Ltd.
Human cytomegalovirus inhibits apoptosis involving upregulation of the antiapoptotic protein Bag‐1
Authors: Li Hai Ping , Yuan Cong Ling , Zho Ying Chun
Published: June 2015

Human cytomegalovirus (HCMV) is an important opportunistic pathogen in immunocompromised individuals and is recognized as a major viral cause of birth defects. HCMV has the ability to establish lifelong persistence and latent infection following primary exposure. Apoptosis is an innate cellular defense response to viral infection. HCMV can block apoptosis in various cell types. Here we show that HCMV promotes survival of human embryonic lung fibroblasts by activating of MAPK/ERK signaling pathway. Bag‐1 is up‐regulated in a MAPK/ERK‐dependent fashion in infected cells. Depletion of Bag‐1 suppresses the antiapoptotic effect of HCMV. Taken together, these data indicate that Bag‐1 up‐regulation is required to maintain apoptosis resistance in HCMV infected cells. J. Med. Virol. 87:1953–1959, 2015. © 2015 Wiley Periodicals, Inc.
Neprilysin gene transfer: A promising therapeutic approach for Alzheimer's disease
Authors: Li Yuanli , Wang Junqing , Zhang Shenghao , Liu Zhaohui
Published: June 2015

Alzheimer's disease (AD) is characterized by widespread neurodegeneration throughout the association cortex and limbic system, deposition of amyloid‐β (Aβ) in the neuropil and around blood vessels, and formation of neurofibrillary tangles. Aβ accumulation is considered the major pathological change in AD progression. In recent years, several therapeutic strategies for treating AD have focused on reducing the Aβ burden in the brain. Among these approaches, the expression of Aβ‐degrading enzymes in the brain has been effective but, so far, impractical for treating patients. Neprilysin (NEP), the most prominent of the Aβ‐degrading enzymes in vivo, has been successfully delivered intracranially by viral vectors and is a promising therapeutic approach for reducing Aβ accumulation and treating AD. However, some challenges are associated with the use of viral and nonviral vectors, including secondary toxicity, activation of the immune response, and low efficiency. Therefore, safe and efficient NEP delivery systems that could avoid the viral problems with minor injury and high transfection efficiency are required to deliver AD medical applications. This Mini‐Review summarizes NEP gene transfer technologies that use viral and nonviral vectors and discusses the rationale and benefits of these delivery systems for AD treatment trials, providing a reference for basic and clinical studies on AD. © 2015 Wiley Periodicals, Inc.
Cultural study and problem‐solving gains: Effects of study abroad, openness, and choice
Authors: Cho Jaee , Morris Michael W.
Published: June 2015

Past research indicates that foreign experience helps problem solving because the experience of adapting one's lifestyle imparts cognitive flexibility. We propose that an independent process involves studying cultural traditions and systems, which imparts foreign concepts that enable unconventional solutions. If so, advantages on unconventionality problems should be associated with experiences studying of another culture, such as typically occurs in study‐abroad programs. The link should be especially strong for individuals with personalities high in openness and in contexts featuring choice. A survey of MBA students' past foreign stays found that greater study abroad was associated with more unconventional solutions and provided mixed support for the two moderating conditions. Study 2 experimentally varied the presence of choice before putting participants through a simulated foreign internship featuring study and situations demanding adaptation. Subsequent solutions to a product design problem were more conventionally Asian and (marginally) less conventionally American in the choice condition, and these effects were mediated by the amount of foreign knowledge acquisition. Implications for selecting employees and developing employees on the basis of foreign experiences are discussed. Copyright © 2015 John Wiley & Sons, Ltd.
Phylogenetic and recombination analysis of genomic sequences of IHHNV
Authors: Shen Hongxing , Zhang Wen , Shao Shihe
Published: June 2015

Infectious hypodermal and hematopoietic necrosis virus (IHHNV) is one of the most recurrent viral pathogens infecting penaeid shrimps. Although previous reports showed that genomic recombination happened among different IHHNV strains, no study has been carried out to systematically elucidate such recombination. In this study, we performed the phylogenetic and recombination analysis of IHHNV the available complete genomes sequences in GenBank. We have found two intra‐group recombination between lineages III and II of infectious group, one inter‐lineage recombination between lineage II of infectious group and non‐infectious group among IHHNV strains.
Soil attributes and plant production changes in a tropical littoral wetland
Authors: Dold Christian , Becker Mathias
Published: June 2015

Lake Naivasha is a freshwater lake in the East African Rift Valley. With continued lake level declines between 1980 and 2011, the newly exposed land areas were gradually taken for agricultural use. The resulting chronosequences allow for an analysis of the effects of land use duration on nutrient dynamics and agricultural production. Transects representing land use durations of 0–30 (cropland) and 15–30 years (pasture) were established on soils formed on alluvial deposits and lacustrine sediments. We assessed changes in topsoil nitrogen (N) stocks (t ha−1), ammonium mineralization potential (N‐supplying capacity), and plant‐available P with increasing durations of land use. An additional greenhouse experiment studied the responses of kikuyu grass (Cenchrus clandestinus) and maize (Zea mays) in potted topsoil collected from differnt land‐use types and chronosequence positions. With increasing duration of land use we noted a significant decline (P< 5%) in soil N contents under both pasture and cropland uses, following a model of exponential decay. The N stocks decreased at 84 kg ha−1a−1and a decay rate constant of 0.019 a−1in pasture soil within 15 years, and at 75 kg ha−1a−1with a decay rate‐constant of 0.013 a−1in cropland soil within 30 years. While the ammonium‐N mineralization potential also decreased with land use duration, the trends were significant only in lacustrine pasture soils. Plant‐available P did not show any trends that were related to the duration of land use. Kikuyu grass and maize accumulated less dry matter and N as the duration of use increased. This biomass accumulation was significantly related to soil N. A continued mineralization of soil organic matter has possibly contributed to the observed soil N depletion over time. The continuous agricultural use of the littoral wetland zone of Lake Naivasha is likely to entail declining production potentials for both pastures and food crops.
History and development of the Schmidt–Hunter meta‐analysis methods
Authors: Schmidt Frank L.
Published: June 2015

In this article, I provide answers to the questions posed by Will Shadish about the history and development of the Schmidt–Hunter methods of meta‐analysis. In the 1970s, I headed a research program on personnel selection at the US Office of Personnel Management (OPM). After our research showed that validity studies have low statistical power, OPM felt a need for a better way to demonstrate test validity, especially in light of court cases challenging selection methods. In response, we created our method of meta‐analysis (initially called validity generalization). Results showed that most of the variability of validity estimates from study to study was because of sampling error and other research artifacts such as variations in range restriction and measurement error. Corrections for these artifacts in our research and in replications by others showed that the predictive validity of most tests was high and generalizable. This conclusion challenged long‐standing beliefs and so provoked resistance, which over time was overcome. The 1982 book that we published extending these methods to research areas beyond personnel selection was positively received and was followed by expanded books in 1990, 2004, and 2014. Today, these methods are being applied in a wide variety of areas. Copyright © 2015 John Wiley & Sons, Ltd.
Introduction to the special issue on the origins of modern meta‐analysis
Authors: Shadish William R.
Published: June 2015

This issue of Research Synthesis Methods is devoted to discussion of the origins of modern meta‐analysis. Three articles by pioneers in development meta‐analysis are by Gene Glass, Frank Schmidt, and Robert Rosenthal, respectively. They reflect on their own experiences about how they made these developments. The fourth article is by William Shadish, and seeks to analyze the impact of meta‐analysis and the reasons why meta‐analysis developed at the time it did, and by the people who did so. The articles are followed by commentaries by Douglas Altman, Iain Chalmers, Harris Cooper, Kay Dickersin, Larry Hedges, David Hoaglin, and Hannah Rothstein, who each comment on both the four target articles and on their own perspectives about how and why meta‐analysis developed when and how it did. Copyright © 2015 John Wiley & Sons, Ltd.
The Importance of Internal Resources and Capabilities and Destination Resources to Explain Firm Competitive Position in the Spanish Tourism Industry
Authors: Camisón César , Puig‐Denia Alba , Forés Beatriz , Fabra María Eugenia , Muñoz Azahara , Muñoz Martínez CÉSAR
Published: June 2015

This study draws on the Resource‐Based View to analyze the effects of distinctive competences in tourism firms and location in a tourism district on competitive position, and explores the moderating effects of the tourism destination. Multiple linear regression was used to test the research hypotheses on a sample of 1019 Spanish tourism firms. Results reveal that financial resources and dynamic and production capabilities favor a better competitive position for tourism firms in general; however, coordination and marketing capabilities are key factors for firms embedded in a tourism district, while dynamic capabilities have a negative effect in this case. Copyright © 2015 John Wiley & Sons, Ltd.
Low, rather than high, body mass index confers increased risk for post‐liver transplant death and graft loss: Risk modulated by model for end‐stage liver disease
Authors: Bambha Kiran M. , Dodge Jennifer L. , Gralla Jane , Sprague David , Biggins Scott W.
Published: June 2015

With increasing attention being paid to optimizing patient outcomes, it has been proposed that liver transplantation (LT) for individuals with elevated body mass index (BMI) values and high Model for End‐Stage Liver Disease (MELD) scores may adversely affect post‐LT outcomes. We investigated the impact of BMI on post‐LT outcomes in the context of MELD at LT. Using United Network for Organ Sharing data, we identified all adult (≥18 years) primary LT recipients from March 1, 2002 to September 30, 2011. BMI categories included the following: underweight, normal, overweight, class I obese, class II obese, and class III obese (<18.5; 18.5‐24.9; 25‐29.9; 30‐34.9; 35‐39.9; ≥40 kg/m2, respectively). One‐year post‐LT death and graft loss were modeled using Cox regression, including interactions between BMI and MELD. A total of 45,551 adult recipients were identified: 68% male; median (interquartile range [IQR]) age 55 years (IQR, 49‐60 years); MELD, 19 (IQR, 13‐26); and donor risk index, 1.39 (IQR, 1.12‐1.69). Representations in the BMI categories were underweight (n = 863, 2%), normal (n = 13,262, 29%), overweight (n = 16,329, 36%), class I obese (n = 9639, 21%), class II obese (n = 4062, 9%), and class III obese (n = 1396, 3%). In adjusted analyses, elevated BMI was not associated with increased risk for death or graft loss. Among the underweight, there were significant interactions between BMI and MELD with respect to death (P = 0.02) and graft loss (P = 0.01), with significantly increased risks for death (hazard ratio [HR], 1.70; 95% confidence interval [CI], 1.38‐2.09; P = 0.006) and graft loss (HR, 1.45; 95% CI, 1.21‐1.74; P = 0.02) among those with low MELD (≤26), compared to normal BMI recipients with low MELD. In conclusion, overweight and obese LT recipients do not have increased risk of death or graft loss regardless of MELD. Underweight patients are at increased risk for poor outcomes post‐LT, specifically underweight recipients with low MELD have increased risk for death and graft loss. Mechanisms underlying this phenomenon warrant further investigation. Liver Transpl 21:1286‐1294, 2015. © 2015 AASLD.
pH‐Responsive H‐Type PMAA2‐b‐HTPBN‐b‐PMAA2 Four‐Arm Star Block Copolymer Micelles for PTX Drug Release
Authors: Luo Yan‐Ling , Han Mei , Xu Feng , Chen Ya‐Shao , Zhang Yong‐Qin
Published: June 2015

pH‐Responsive H‐type poly(methylacrylic acid‐block‐four hydroxyl terminated poly(butadiene‐acrylobitrile)‐block‐poly(methylacrylic acid (PMAA2‐b‐HTPBN‐b‐PMAA2) block copolymers were synthesized via atom transfer radical polymerization and the follow‐up hydrolysis, and characterized by 1H NMR, FT‐IR and SEC. The block copolymers could self‐assemble into nanoscale spherical core‐shell micelle aggregates in aqueous solution, and the physicochemical properties depended on the system composition and pH media, with pH phase transition at 5.7–6.1. The copolymer micelle aggregates exhibited pH‐triggered drug release and cytotoxicity, and could potentially be used as drug targeting release carriers.
Soft PEG‐Hydrogels with Independently Tunable Stiffness and RGDS‐Content for Cell Adhesion Studies
Authors: M. Jonker Anika , A. Bode Saskia , H. Kusters Addie , van Hest Jan C. M. , Löwik Dennis W. P. M.
Published: June 2015

Poly(ethylene)glycol (PEG)‐based hydrogels are often used as matrix material for cell culturing. An efficient method to prepare soft PEG gels is by cross‐linking via copper‐free strain‐promoted azide‐alkyne cycloaddition (SPAAC). Here, the effect of polymer density and RGDS‐content on hydrogel formation and cell adhesion was studied, by varying the total polymer content (10, 20 and 30 mg · mL−1) and the amount of RGDS moieties (0–100%) independently of each other. Rheology studies confirmed the soft nature of the hydrogels (G′ = 25–2 298 Pa). HOS cells are able to adhere well to all RGDS‐containing gels. Interestingly, both HeLa cells and NIH 3T3 fibroblasts showed substantial adherence to 10 and 20 mg · mL−1 gels, but with increased hydrogel stiffness (30 mg · mL−1), their cellular adhesion decreased significantly.
Novel Insights into Pressure‐Sensitive Adhesives Based on Plant Oils
Authors: Maaßen Wiebke , Oelmann Stefan , Peter David , Oswald Walter , Willenbacher Norbert , Meier Michael A. R.
Published: June 2015

This work investigates the synthesis of bio‐based pressure‐sensitive adhesives and their characterization in terms of mechanical properties relevant to processing and application. The synthesis of monomers based on various fatty acids derived from vegetable oils as renewable feedstock via a one‐step, a two‐step, and a three‐step route is described. The resulting monomers are polymerized via free radical polymerization resulting in high molecular weight polymers with adhesive properties. Adhesives are also obtained as aqueous dispersions by means of miniemulsion polymerization. In particular, the monomer acrylated methyl oleate (4ac) and the thereof derived polymer are intensively studied. The synthesized homopolymers show characteristic mechanical and adhesive properties similar to conventional pressure sensitive adhesives.

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Modeling Acrylic Acid Radical Polymerization in Aqueous Solution
Authors: Wittenberg Nils F. G. , Preusser Calista , Kattner Hendrik , Stach Marek , Lacík Igor , Hutchinson Robin A. , Buback Michael
Published: June 2015

Batch radical polymerization of 5–40 wt% non‐ionized acrylic acid (AA) in aqueous solution has been studied between 35 and 90 °C under variation of initiator concentration and type as well as upon addition of different levels of 2‐mercaptoethanol as chain‐transfer agent (CTA). Chain‐length‐dependent termination was taken into account in a model developed to describe the system, as high amounts of CTA have an impact on polymerization kinetics due to reduced chain length. The model also considers the 1,5‐hydrogen shift (backbiting) reaction that transforms the secondary propagating radical into a tertiary midchain radical, with the backbiting reaction quantified via 13C NMR. The model developed is the most comprehensive treatment to date of this complex polymerization system and is able to represent monomer conversion profiles and polymer molar mass distributions over a wide range of conditions.
Robust bottleneck routing games
Authors: Werth Thomas L. , Büttner Sabine , Krumke Sven O.
Published: June 2015

Network routing games have attracted a lot of attention over the last years. However, most of the work assumes that the users have complete knowledge about the data in the network, in particular, about the precise travel times over the links. In this article, we address the more realistic case that users only know lower and upper bounds for the travel times and learn about the actual realization later. Thus, users cannot expect to choose a strategy which is optimal for each realization (scenario). This situation leads to combining concepts from robust optimization with algorithmic game theory. Specifically, we study the case where each user wants to minimize her regret, which is defined to be the worst‐case difference of her bottleneck objective (the cost of her most expensive resource) to the optimum attainable value given a priori knowledge about the actual scenario. We show that in robust bottleneck routing games, equilibria do not always exist, but the existence can be guaranteed under the restriction that the problem is symmetric and the intervals of uncertainty have constant length. We prove that in general it is NP‐hard to decide whether a given instance has a robust equilibrium. In the case of constant‐length intervals of uncertainty, a robust equilibrium can be computed efficiently (in the symmetric case). We also investigate the Price of Robustness, which formally quantifies the lack of performance due to uncertainty and give a tight bound. © 2015 Wiley Periodicals, Inc. NETWORKS, Vol. 66(1), 57–66 2015
Parallel preconditioners and multigrid solvers for stochastic polynomial chaos discretizations of the diffusion equation at the large scale
Authors: Lee Barry
Published: June 2015

This paper presents parallel preconditioners and multigrid solvers for solving linear systems of equations arising from stochastic polynomial chaos formulations of the diffusion equation with random coefficients. These preconditioners and solvers are extensions of the preconditioner developed in an earlier paper for strongly coupled systems of elliptic partial differential equations that are norm equivalent to systems that can be factored into an algebraic coupling component and a diagonal differential component. The first preconditioner, which is applied to the norm equivalent system, is obtained by sparsifying the inverse of the algebraic coupling component. This sparsification leads to an efficient method for solving these systems at the large scale, even for problems with large statistical variations in the random coefficients. An extension of this preconditioner leads to stand‐alone multigrid methods that can be applied directly to the actual system rather than to the norm equivalent system. These multigrid methods exploit the algebraic/differential factorization of the norm equivalent systems to produce variable‐decoupled systems on the coarse levels. Moreover, the structure of these methods allows easy software implementation through re‐use of robust high‐performance software such as the Hypre library package. Two‐grid matrix bounds will be established, and numerical results will be given. Copyright © 2015 John Wiley & Sons, Ltd.
Positron annihilation spectroscopy studies of proton exchange membranes used in fuel cells
Authors: Constantin Florin , Barna Catalina , Mereuta Paul
Published: June 2015

In the recent years, fuel cells became more than a promise, getting closer to a technological reality. Proton exchange membrane (PEM) used as electrolyte is a valuable solution, and Nafion® seems to be the best competitor. This paper reports a positron annihilation spectroscopy study of Nafion® behavior employed as a proton exchange membrane in a working fuel cell. A continuous survey of the fuel cell behavior using positron annihilation lifetime spectroscopy and coincidence Doppler broadening spectroscopy was conducted over a 50‐day period, and the results of these measurements are presented and discussed. Copyright © 2015 John Wiley & Sons, Ltd.
Clonality analysis of combined Brenner and mucinous tumours of the ovary reveals their monoclonal origin
Authors: Wang Yihong , Wu Ren‐chin , Shwartz Lauren Ende , Haley Lisa , Lin Ming‐tse , Shih Ie‐ming , Kurman Robert J
Published: June 2015

The derivation of ovarian intestinal‐type mucinous tumours is not well established. Some are derived from teratomas but the origin of the majority is not clear. It has been recently proposed that the non‐germ cell group may be derived from Brenner tumours, as the association of a mucinous tumour with a Brenner tumour is frequently observed. In order to explore the histogenesis of these neoplasms, we undertook a clonality analysis of the two components of ten combined Brenner and mucinous tumours using a human androgen receptor gene (HUMARA) assay. All eight informative cases of ten showed a concordant X‐chromosome inactivation pattern between the two tumour components, indicative of a shared clonal origin (p = 0.0039). Microsatellite genotyping in five of the combined tumours displayed an identical heterozygous pattern with paired Fallopian tube tissue, indicative of a somatic cell origin. In addition, paired box protein 8, a highly sensitive Müllerian epithelial marker, was not detected by immunohistochemistry in either tumour component in any of the ten tumours, suggesting that this subset of mucinous tumours does not originate from Müllerian‐derived epithelium. In conclusion, this study demonstrates that in combined mucinous and Brenner tumours, there is a shared clonal relationship between the two different tumour components and suggests that some pure mucinous tumours may develop from a Brenner tumour in which the Brenner tumour component becomes compressed and obliterated by an expanding mucinous neoplasm. Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
CD47 deficiency ameliorates autoimmune nephritis in Faslpr mice by suppressing IgG autoantibody production
Authors: Shi Lei , Bian Zhen , Chen Celia XJ , Guo Ya‐Nan , Lv Zhiyuan , Zeng Caihong , Liu Zhihong , Zen Ke , Liu Yuan
Published: June 2015

CD47, a self‐recognition marker, plays an important role in both innate and adaptive immune responses. To explore the potential role of CD47 in activation of autoreactive T and B cells and the production of autoantibodies in autoimmune disease, especially systemic lupus erythematosus (SLE), we have generated CD47 knockout Faslpr (CD47−/−−Faslpr) mice and examined histopathological changes in the kidneys, cumulative survival rates, proteinuria, extent of splenomegaly and autoantibodies, serum chemistry and immunological parameters. In comparison with Faslpr mice, CD47−/−−Faslpr mice exhibit a prolonged lifespan and delayed autoimmune nephritis, including glomerular cell proliferation, basement membrane thickening, acute tubular atrophy and vacuolization. CD47−/−−Faslpr mice have lower levels of proteinuria, associated with reduced deposition of complement C3 and C1q, and IgG but not IgM in the glomeruli, compared to age‐matched Faslpr mice. Serum levels of antinuclear antibodies and anti‐double‐stranded DNA antibodies are significantly lower in CD47−/−−Faslpr than in Faslpr mice. CD47−/−–Faslpr mice also display less pronounced splenomegaly than Faslpr mice. The mechanistic studies further suggest that CD47 deficiency impairs the antigenic challenge‐induced production of IgG but not IgM, and that this effect is associated with reduction of T follicular cells and impairment of germinal centre development in lymphoid tissues. In conclusion, our results demonstrate that CD47 deficiency ameliorates lupus nephritis in Faslpr mice via suppression of IgG autoantibody production. Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
The clonal relationships between pre‐cancer and cancer revealed by ultra‐deep sequencing
Authors: Wood Henry M , Conway Caroline , Daly Catherine , Chalkley Rebecca , Berri Stefano , Senguven Burcu , Stead Lucy , Ross Lisa , Egan Philip , Chengot Preetha , Graham Jennifer , Sethi Neeraj , Ong Thian K , High Alec , MacLennan Kenneth , Rabbitts Pamela
Published: June 2015

The study of the relationships between pre‐cancer and cancer and identification of early driver mutations is becoming increasingly important as the value of molecular markers of early disease and personalised drug targets is recognized, especially now the extent of clonal heterogeneity in fully invasive disease is being realized. It has been assumed that pre‐cancerous lesions exhibit a fairly passive progression to invasive disease; the degree to which they, too, are heterogeneous is unknown. We performed ultra‐deep sequencing of thousands of selected mutations, together with copy number analysis, from multiple, matched pre‐invasive lesions, primary tumours and metastases from five patients with oral cancer, some with multiple primary tumours presenting either synchronously or metachronously, totalling 75 samples. This allowed the clonal relationships between the samples to be observed for each patient. We expose for the first time the unexpected variety and complexity of the relationships between this group of oral dysplasias and their associated carcinomas and, ultimately, the diversity of processes by which tumours are initiated, spread and metastasize. Instead of a series of genomic precursors of their adjacent invasive disease, we have shown dysplasia to be a distinct dynamic entity, refuting the belief that pre‐cancer and invasive tumours with a close spatial relationship always have linearly related genomes. We show that oral pre‐cancer exhibits considerable subclonal heterogeneity in its own right, that mutational changes in pre‐cancer do not predict the onset of invasion, and that the genomic pathway to invasion is neither unified nor predictable. Sequence data from this study have been deposited in the European Nucleotide Archive, Accession No. PRJEB6588. Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Morphology, mechanical property, and modeling evaluation of P(3HB‐co‐4HB)/nano‐ZnO composites
Authors: Hu Jingwen , Xia Runpu , Yang Hua , Lu Xiuping
Published: June 2015

Poly(3‐hydroxybutyrate‐co‐4‐hydroxybutyrate) (P(3HB‐co‐4HB)) and nanometer zinc oxide (nano‐ZnO) modified by solid titanate coupling agent (TMC980) were selected to prepare P(3HB‐co‐4HB)/nano‐ZnO composites via melt blending. Scanning electron microscope (SEM), capillary rheometer, polarized optical microscopy (POM), and universal testing machine were used to characterize the fracture morphology, rheological property, spherulitic morphology, and mechanical properties of P(3HB‐co‐4HB)/nano‐ZnO composites. Halpin‐Tsai equation was used to quantitatively evaluate the dispersion and enhancement effects of modified nano‐ZnO on P(3HB‐co‐4HB). The results demonstrated that modified nano‐ZnO at 0.2%∼0.3% of volume fraction could significantly improve the tensile strength, elastic modulus and toughness, increase the melt viscosity, refine the spherulitic size, and rough the fracture morphology of P(3HB‐co‐4HB)/nano‐ZnO composites. Based on the effective aspect ratio (ξ) from Halpin‐Tsai model evaluation, the optimal dosage of nano‐ZnO for P(3HB‐co‐4HB)/nano‐ZnO composites was also at 0.2%∼0.3% of volume fraction. The Halpin‐Tsai equation was found to predict the experimental data most accurately for the P(3HB‐co‐4HB)/nano‐ZnO composites. POLYM. COMPOS., 37:3113–3121, 2016. © 2015 Society of Plastics Engineers
Temperature‐responsive catalytic performance of Ag nanoparticles endowed by poly (N‐isopropylacrylamide‐co‐acrylic acid) microgels
Authors: Li Kun , Chen Xi , Wang Zeya , Xu Liangliang , Fu Weigui , Zhao Lizhi , Chen Li
Published: June 2015

In this study, we facilely introduce silver nanoparticles into Poly(N‐isopropylacrylamide‐co‐acrylic acid)(Poly(NIPAM‐co‐AA)) microgels and specially focus on the effect of hydrophilic acrylic acid segments on the responsive catalytic performance of silver nanoparticles. The obtained Poly(NIPAM‐co‐AA)/AgNPs composites are characterized by Fourier transform infrared spectra, X‐ray diffraction, X‐ray photoelectron spectroscopy, and transmission electron microscopy. The composites as catalysts are applied to the hydrogenation reaction of p‐nitrophenol and the related conditions such as reaction temperature, concentration of p‐nitrophenol, and the loadings of Ag nanoparticles are studied in detail. NIPAM segments of composites conveniently give silver nanoparticles a controllable characteristic for catalytic reaction by their conformation variation. AA segments of composites not only provide good stability and dispersibility for silver nanoparticles but also favor an easier diffusion of p‐nitrophenol to Ag NPs. POLYM. COMPOS., 38:708–718, 2017. © 2015 Society of Plastics Engineers
Preparation and mechanical characterization of chicken feather/PLA composites
Authors: Baba Buket Okutan , Özmen Ugur
Published: June 2015

Green composites, a bio‐based polymer matrix is reinforced by natural fibers, are special class of bio‐composites. Interest about green composites is continuously growing because they are environment‐friendly. This study describes the preparation and mechanical characterization of green composites using polylactic acid (PLA) matrix including chicken feather fiber (CFF) as reinforcement. Extrusion and an injection molding process were used to prepare CFF/PLA composites at a controlled temperature range. CFF/PLA composites with fiber mass content of 2%, 5%, and 10% were manufactured. The effects of fiber concentration and fiber length on mechanical properties of CFF/PLA composites have been studied. Mechanical properties of composites were investigated by tensile, compression, bending, hardness, and Izod impact testing. The results of experiments indicated that Young's modulus, compressive strength, flexural modulus, and hardness of the PLA reinforced CFF composites are higher but tensile strength, elongation at break, bending strength and impact strength of them are lower than pure PLA. The results indicate that these types of composites can be used for various applications. POLYM. COMPOS., 38:837–845, 2017. © 2015 Society of Plastics Engineers
Improvement in thermal conductivity and mechanical properties of ethylene‐propylene–diene monomer rubber by expanded graphite
Authors: He Shaojian , Lin Yankai , Chen Lin , Cao Shanqiao , Lin Jun , Du Xiaoze
Published: June 2015

Thermally conductive fillers are usually employed in the preparation of rubber composites to enhance thermal conductivity. In this work, ethylene‐propylene‐diene monomer rubber (EPDM)/expanded graphite (EG) and EPDM/graphite composites with up to 100 phr filler loading were prepared. Compared to EPDM/graphite compounds with the same filler loading, stronger filler network was demonstrated for EPDM/EG compounds. Thermal conductivity and mechanical properties of EPDM/graphite and EPDM/EG composites were compared and systematically investigated as a function of the filler loading. The thermal conductivity of both EPDM/graphite and EPDM/EG composites increased with increasing volume fraction of fillers, and could be well fitted by Geometric Mean Model. The thermal conductivity as high as 0.910 W  ·  m−1 ·   K−1 was achieved for the EPDM/EG composite with 25.8 vol% EG, which was ∼4.5 times that of unfilled EPDM. Compared to EPDM/graphite composites, EPDM/EG composites exhibited much more significant improvement in thermal conductivity and mechanical properties, which could be well correlated with the better filler‐matrix interfacial compatibility and denser structure in EPDM/EG composites, as revealed in the SEM images of tensile fracture surfaces. POLYM. COMPOS., 38:870–876, 2017. © 2015 Society of Plastics Engineers
Determination of terpenoid indole alkaloids in hairy roots of Rhazya stricta (Apocynaceae) by GC‐MS
Authors: Akhgari Amir , Laakso Into , Seppänen‐Laakso Tuulikki , Yrjönen Teijo , Vuorela Heikki , Oksman‐Caldentey Kirsi‐Marja , Rischer Heiko
Published: June 2015

Introduction

Rhazya stricta Decne. (Apocynaceae) is a medicinal plant rich in terpenoid indole alkaloids (TIAs), some of which possess important pharmacological properties. The study material including transgenic hairy root cultures have been developed and their potential for alkaloid production are being investigated.

Objective

In this study, a comprehensive GC‐MS method for qualitative and quantitative analysis of alkaloids from Rhazya hairy roots was developed.

Methods

The composition of alkaloids was determined by using GC‐MS. In quantification, the ratio between alkaloid and internal standard was based on extracted ion from total ion current (TIC) analyses.

Results

The developed method was validated. An acceptable precision with RSD ≤ 8% over a linear range of 1 to 100 µg/mL was achieved. The accuracy of the method was within 94–107%. Analysis of hairy root extracts indicated the occurrence of a total of 20 TIAs. Six of them, pleiocarpamine, fluorocarpamine, vincamine, ajmalicine and two yohimbine isomers are reported here for the first time in Rhazya. Trimethylsilyl (TMS) derivatisation of the extracts resulted in the separation of two isomers for yohimbine and also for vallesiachotamine. Clearly improved chromatographic profiles of TMS‐derivatives were observed for vincanine and for minor compounds vincamine and rhazine.

Conclusion

The results show that the present GC‐MS method is reliable and well applicable for studying the variation of indole alkaloids in Rhazya samples. Copyright © 2015 John Wiley & Sons, Ltd.
Development of a rapid immunochromatographic strip test for the detection of Mulberroside A
Authors: Inyai Chadathorn , Komaikul Jukrapun , Kitisripanya Tharita , Tanaka Hiroyuki , Sritularak Boonchoo , Putalun Waraporn
Published: June 2015

Introduction

Mulberroside A (MuA) is the major active anti‐tyrosinase compound in the root bark extract of Morus alba L. (Moraceae). Typically, MuA is widely employed as an active ingredient in whitening cosmetics. A rapid and simple assay system utilizing a small quantity of test sample is essential for the detection of MuA in large number of samples. An immunoassay using highly specific MuA polyclonal antibodies may be useful for the determination of small quantities of MuA in test samples.

Objective

To establish a rapid qualitative MuA test, an immunochromatographic strip test was developed using anti‐MuA polyclonal antibodies (anti‐MuA PAb).

Methodology

The qualitative assay was based on a competitive immunoassay where the detection reagent consisted of anti‐MuA PAb colored with colloidal gold particles. The capture reagent was a MuA‐ovalbumin (MuA‐OVA) conjugate immobilized on the test strip membrane.

Results

A sample containing MuA and the detection reagent were incubated together with immobilized capture reagent on a nitrocellulose membrane. When MuA was present, it competed with the immobilized conjugates on the strip membrane to bind a limited amount of colored antibodies; thus, a positive sample showed no color on the capture spot zone. The detection limit for the strip test was 2 µg/mL. The developed immunochromatographic strip test was utilized to determine MuA in plants, medical preparations and cosmetic samples.

Conclusion

This immunochromatographic strip test is advantageous as a rapid, simple and sensitive screening method for the detection of MuA in plant extracts, cosmetic samples and pharmaceutical products.
Prenatal diagnosis and postnatal outcome of massive abdominal aortic aneurysms—a case report
Authors: Bills Victoria L. , Smithson Sarah F. , Tsai‐Goodman Beverly , Tometski Andrew , Overton Timothy G.
Published: June 2015

What's already known about this topic?

Vascular aneurysm is an extremely rare fetal abnormality and is usually secondary to genetic defects of vascular development such as Marfan, Loeys–Dietz and Ehler's–Danlos Type IV syndromes.

What does this study add?

This is the first report of massive fetal aortic aneurysms occurring as a sporadic event, documenting the postnatal pathophysiological consequences and the inadequacy of effective postnatal surgical correction.

© 2015 John Wiley & Sons, Ltd.