bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of the representativeness of a Dutch non‐malformed control group for the general pregnant population: are these controls useful for EUROCAT?
Authors: Jentink Janneke , Zetstra‐van der Woude A. Priscilla , Bos Jens , de Jong‐van den Berg Lolkje T. W. 
Published: September 2011

ABSTRACTPurposeA case–control study is the most powerful design to test the risk of specific congenital malformations associated with a specific drug. However, malformation registries often lack non‐malformed controls. For the Dutch EUROCAT, we collected a non‐malformed control group: the ‘Healthy Pregnant’. The aim of this study was to evaluate the representativeness of this control group for the general pregnant population in the northern part of the Netherlands.MethodsThe Healthy Pregnant data set includes data from two midwife practices. The baseline characteristics of mother and child including smoking status, drinking status, body mass index, maternal age, educational level, exposures to several drugs for chronic diseases and pregnancy related symptoms were evaluated.ResultsCompared with the general population, mothers in Healthy Pregnant group (n = 556) were from either low or high education level, were more likely to have a body mass index > 25 kg/m2 (26% versus 22%, p = 0.08) or to smoke (19% versus 10%, p < 0.01) but were less likely to consume alcohol (20% versus 29%, p < 0.01). The use of drugs for chronic conditions was lower in Healthy Pregnant group. Furthermore, drugs for occasional use were prescribed less frequently, and a significant underreporting of children with a low birth weight and a short duration of gestation was found.ConclusionThe Healthy Pregnant data set was not representative of the general pregnant population in the northern part of the Netherlands. Specifically, the exposure to (chronic) drugs was underestimated, possibly a result of second‐line care on the basis of medical indication. Thus, continuous investigation of options for improvement of the Healthy Pregnant database is required. Copyright © 2011 John Wiley & Sons, Ltd.
Cold isostatic pressing technique for producing highly efficient flexible dye‐sensitised solar cells on plastic substrates
Authors: Weerasinghe Hasitha C. , Sirimanne Prasad M. , Simon George P. , Cheng Yi‐Bing 
Published: September 2011

ABSTRACTOne of the biggest challenges for making dye‐sensitised solar cells (DSCs) on plastic substrates is the difficulty in making good quality nanoporous TiO2 films with both good mechanical stability and high electrical conductivity. Cold isostatic pressing (CIP) is a powder compaction technique that applies an isostatic pressure to a powder sample in all directions. It is particularly suitable for making thin films on plastic substrates, including non‐flat surfaces. Cold isostatically pressed nanocrystalline TiO2 electrodes with excellent mechanical robustness were prepared on indium tin oxide (ITO)‐coated polyethylene naphthalate (PEN) substrates in the absence of organic binders and without heat treatment. The morphology and the physical properties of the TiO2 films prepared by the CIP method were found to be very compatible with requirements for flexible DSCs on plastics. This room‐temperature processing technique has led to an important technical breakthrough in producing high efficiency flexible DSCs. Devices fabricated on ITO/PEN films by this method using standard P‐25 TiO2 films with a Ru‐complex sensitiser yielded a maximum incident photon‐to‐current conversion efficiency of 72% at the wavelength of 530 nm and showed high conversion efficiencies of 6.3% and 7.4% for incident light intensities of 100 and 15 mW cm−2, respectively, which are the highest power conversion efficiencies achieved so far for any DSC on a polymer substrate using the widely used, commercially available P‐25 TiO2 powder. Copyright © 2011 John Wiley & Sons, Ltd.
Quantitative proteomics analysis of adsorbed plasma proteins classifies nanoparticles with different surface properties and size
Authors: Zhang Haizhen , Burnum Kristin E. , Luna Maria L. , Petritis Brianne O. , Kim Jong‐Seo , Qian Wei‐Jun , Moore Ronald J. , Heredia‐Langner Alejandro , Webb‐Robertson Bobbie‐Jo M. , Thrall Brian D. , Camp David G. , Smith Richard D. , Pounds Joel G. , Liu Tao 
Published: September 2011

AbstractNanoparticle biological activity, biocompatibility and fate can be directly affected by layers of readily adsorbed host proteins in biofluids. Here, we report a study on the interactions between human blood plasma proteins and nanoparticles with a controlled systematic variation of properties using 18O‐labeling and LC‐MS‐based quantitative proteomics. We developed a novel protocol to both simplify isolation of nanoparticle bound proteins and improve reproducibility. LC‐MS analysis identified and quantified 88 human plasma proteins associated with polystyrene nanoparticles consisting of three different surface chemistries and two sizes, as well as, for four different exposure times (for a total of 24 different samples). Quantitative comparison of relative protein abundances was achieved by spiking an 18O‐labeled “universal” reference into each individually processed unlabeled sample as an internal standard, enabling simultaneous application of both label‐free and isotopic labeling quantification across the entire sample set. Clustering analysis of the quantitative proteomics data resulted in distinctive patterns that classified the nanoparticles based on their surface properties and size. In addition, temporal data indicated that the formation of the stable protein corona was at equilibrium within 5 min. The comprehensive quantitative proteomics results obtained in this study provide rich data for computational modeling and have potential implications towards predicting nanoparticle biocompatibility.
Effect of isomeric pyridine moieties in ethynylstyrene derivatives on their anionic polymerization
Authors: Kang Beom‐Goo , Kang Nam‐Goo , Lee Jae‐Suk 
Published: September 2011

AbstractThe anionic polymerization behaviors of ethynylstyrene derivatives containing isomeric pyridine moieties, 2‐(2‐(4‐vinylphenyl)ethynyl)pyridine (A), 3‐(2‐(4‐vinylphenyl)ethynyl)pyridine (B), and 4‐(2‐(4‐vinylphenyl)ethynyl)pyridine (C), were investigated in the identical conditions. The anionic polymerization of A–C was performed with (diphenylmethyl)potassium (Ph2CHK) in tetrahydrofuran (THF) at −78 °C. The polymerization of A proceeded quantitatively at –78 °C for 4 h, and the resulting poly(A) possessed predictable molecular weights (Mn = 3300–68,500) and narrow molecular weight distributions (MWDs) (Mw/Mn = 1.04–1.11). In contrast, the anionic polymerization of B was not performed at –78 °C for 4 h due to the occurrence of side reactions. The monomer B was quantitatively recovered after the reaction. In the polymerization of C performed at –78 °C for 6 h, observed Mn values of the resulting poly(C) were in good agreement with calculated molecular weights based on monomer to initiator ratios, but the MWDs were somewhat broad (Mw/Mn = 1.23–1.31). To estimate the reactivity of A and to characterize its living nature, the block copolymerization of A with 2‐vinylpyridine (2VP) and methyl methacrylate (MMA) was performed. The well‐defined block copolymers, poly(2VP)‐b‐poly(A) and poly(A)‐b‐poly(MMA), were successfully synthesized without any additives. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Preparation of polymer hollow microspheres covered by polymer solid particles via two polymerization steps
Authors: Zhao Yongliang , Yin Guannan , Zheng Zheng , Wang Haitao , Du Qiangguo 
Published: September 2011

AbstractA novel surface modification method for titania nanoparticles is provided via the surface‐initiated photocatalytic polymerization with the aid of acrylic acid (AA) or sodium styrene sulfonate (NaSS). The properties of modified titania nanoparticles are investigated with aqueous electrophoresis measurements, dynamic light scattering (DLS), and transmission electron microscopy (TEM). Then the modified titania is used as Pickering stabilizer for further polymerization and the morphology of the resulted polymer microspheres is characterized by TEM and field‐emission scanning electron microscopy. It is proven that the addition of AA or NaSS for the surface‐initiated polymerization can obviously affect the structure and morphology of the final polymer composite microspheres. The formation mechanism of several kinds of polymer particles is also proposed. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Assembling hyperbranched polymerics
Authors: Peleshanko Sergiy , Tsukruk Vladimir V. 
Published: September 2011

AbstractA condensed overview discusses the existing grafting approaches and the surface behavior of various hyperbranched polymers. We focus on the recent strategies and corresponding characterization of the resulting surface morphologies and structures with a number of relevant recent results from the authors' own research and existing literature. Some results discussed here are important for prospective applications of hyperbranched polymers in biomedical fields, for resistive coatings, tough blends, and reinforced nanocomposites are briefly summarized as well. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 50: 83–100, 2012
PSA regulates androgen receptor expression in prostate cancer cells
Authors: Saxena Parmita , Trerotola Marco , Wang Tao , Li Jing , Sayeed Aejaz , VanOudenhove Jennifer , Adams Dave S. , FitzGerald Thomas J. , Altieri Dario C. , Languino Lucia R. 
Published: September 2011

AbstractBACKGROUNDProstate‐specific antigen (PSA) is a pivotal downstream target gene of the androgen receptor (AR), and a serum biomarker to monitor prostate cancer (PrCa) progression. It has been reported that PSA transactivates AR, but the mechanistic requirements of this response have not been investigated.METHODSWe studied the localization of PSA, AR, and Src in intracellular compartments of synthetic androgen (R1881)‐stimulated LNCaP and C4‐2B PrCa cells, using immunofluorescence and subcellular fractionation approaches. We also investigated the effect of downregulation of PSA on AR expression by immunoblotting and real‐time PCR using short hairpin RNA (shRNA) and small interfering RNA (siRNA). Src activity was analyzed by immunoblotting.RESULTSR1881 stimulation induced nuclear localization of both PSA and AR in LNCaP and C4‐2B PrCa cells as well as increased phosphorylation of Src. Stable shRNA or transient siRNA knockdown of PSA resulted in reduced AR protein levels as well as AR mRNA levels in C4‐2B cells. Similar to C4‐2B cells, ablation of AR levels upon silencing of PSA was also confirmed in VCaP cells, another androgen‐independent cell line. Silencing of PSA did not cause significant changes in Src activation; besides, Src regulation by integrins did not appear to affect AR transcriptional activity.CONCLUSIONSPSA localizes to nuclei of androgen‐stimulated PrCa cells, and controls AR mRNA and protein levels. This regulatory loop is specific for PSA, does not involve known AR activators such as Src and AKT, and may contribute to AR signaling under conditions of increasing PSA levels in patients. Prostate 72:769–776, 2012. © 2011 Wiley Periodicals, Inc.
Identifying continuous pores in protein structures with PROPORES by computational repositioning of gating residues
Authors: Lee Po‐Hsien , Helms Volkhard 
Published: September 2011

AbstractProteins containing concavities such as pockets, cavities, and tunnels or pores perform important functions in ligand‐induced signal transduction, enzymatic catalysis, and in facilitating the permeation of small molecules through membranes. Computational algorithms for identifying such shapes are therefore of great use for studying the mechanisms of these reactions. We developed the novel toolkit PROPORES for pore identification and applied our program to the systems aquaporin, tryptophan synthase, leucine transporter, and acetylcholinesterase. As a novel feature, the program checks whether access to occluded ligand binding pockets or blocked channels can be achieved by systematically rotating side chains of the gating residues. In this way, we obtain a more flexible view of the putative structural adaptability of protein structures. For the four systems mentioned, the new method was able to identify connections between pores that are separated in the X‐ray structures or to connect internal pores with the protein surrounding. The software is available from http://gepard.bioinformatik.uni‐saarland.de/software/propores/. Proteins 2012. © 2011 Wiley Periodicals, Inc.
Allosteric regulation of PKCθ: Understanding multistep phosphorylation and priming by ligands in AGC kinases
Authors: Seco Jesus , Ferrer‐Costa Carles , Campanera Josep M. , Soliva Robert , Barril Xavier 
Published: September 2011

AbstractProtein kinases play critical roles in cellular activation and differentiation, and are involved in numerous pathophysiological processes. As a critical component of the regulatory circuitry of the cell, the kinase domain has the ability to integrate multiple signals, yielding a predetermined output. In PKC and other protein kinases of the AGC family, several phosphorylation sites control the activity, but these are in turn influenced by the presence of ligands in the binding pocket, which promotes phosphorylation. Here, we take PKC‐theta as a prototypical member of the family and use molecular dynamics simulations to investigate the cross‐talk that exists between regulatory and functional sites. We first show how the apo‐unphosphorylated form of the kinase is populating a conformational space in which access to the ATP binding site and to the activation loop (AL) are simultaneously hindered. This could explain why the inactive state is not only catalytically incompetent but also resistant to activation. AL phosphorylation induces ATP binding site opening, which can then readily accept the cofactor. But the signal transmission mechanism works both ways, and if ligand binding to the unphosphorylated form occurs first, the AL is de‐protected and becomes exposed to phosphorylation, thus providing an explanation for the paradoxical activation of PKCs by their inhibitors. Proteins 2012; © 2011 Wiley Periodicals, Inc.
Secondary‐structure analysis of alcohol‐denatured proteins by vacuum‐ultraviolet circular dichroism spectroscopy
Authors: Matsuo Koichi , Sakurada Yoshie , Tate Shin‐ichi , Namatame Hirofumi , Taniguchi Masaki , Gekko Kunihiko 
Published: September 2011

AbstractTo elucidate the structural characteristics of alcohol‐denatured proteins, we measured the vacuum‐ultraviolet circular dichroism (VUVCD) spectra of six proteins—myoglobin, human serum albumin, α‐lactalbumin, thioredoxin, β‐lactoglobulin, and α‐chymotrypsinogen A—down to 170 nm in trifluoroethanol solutions (TFE: 0−50%) and down to 175 nm in methanol solutions (MeOH: 0−70%) at pH 2.0 and 25°C, using a synchrotron‐radiation VUVCD spectrophotometer. The contents of α‐helices, β‐strands, turns, poly‐L‐proline type II helices (PPIIs), and unordered structures of these proteins were estimated using the SELCON3 program, including the numbers of α‐helix and β‐strand segments. Furthermore, the positions of α‐helices and β‐strands on amino acid sequences were predicted by combining these secondary‐structure data with a neural‐network method. All alcohol‐denatured proteins showed higher α‐helix contents (up to ∼ 90%) compared with the native states, and they consisted of several long helical segments. The helix‐forming ability was higher in TFE than in MeOH, whereas small amounts of β‐strands without sheets were formed in the MeOH solution. The produced α‐helices were transformed dominantly from the β‐strands and unordered structures, and slightly from the turns. The content and mean length of α‐helix segments decreased as the number of disulfide bonds in the proteins increased, suggesting that disulfide bonds suppress helix formation by alcohols. These results demonstrate that alcohol‐denatured proteins constitute an ensemble of many long α‐helices, a few β‐strands and PPIIs, turns, and unordered structures, depending on the types of proteins and alcohols involved. Proteins 2012;. © 2011 Wiley Periodicals, Inc.
Long term stabilization of reaction center protein photochemistry by carbon nanotubes
Authors: Magyar Melinda , Hajdu Kata , Szabó Tibor , Hernádi Klára , Dombi András , Horváth Endre , Magrez Arnaud , Forró László , Nagy László 
Published: September 2011

AbstractThe long term stability and the redox interaction between single walled carbon nanotubes (SWNTs) and photosynthetic reaction center proteins (RCs) purified from purple bacterium Rhodobacter sphaeroides R‐26 in the SWNT/RC complex has been investigated. The binding of SWNT to RC results in an accumulation of positive (the oxidized primary electron donor, P+) and negative (semiquinone forms, Q and Q, the reduced primary and secondary quinones, respectively) charges followed by slow reorganization of the protein structure after excitation. The photochemical activity of the SWNT/RC complexes remains stable for several weeks even in dried form. In the absence of SWNT the secondary quinone activity decays quickly as a function of time after drying the RC onto a glass surface. Polarography measurements substantiate the idea that there is an electronic interaction between the RCs and SWNTs after light excitation, which was suggested earlier by optical measurements. The special electronic properties of the SWNT/protein complexes open the possibility for several applications, e.g., in microelectronics, analytics, or energy conversion and storage.
Spin transport in ferromagnetically contacted carbon nanotubes
Authors: Meyer C. , Morgan C. , Schneider C. M. 
Published: September 2011

AbstractWe present magnetoresistance (MR) measurements on carbon nanotubes (CNTs) with different ferromagnetic leads. A sample with permalloy (Ni80Fe20) contacts shows the expected tunneling‐type MR effect. Measurements on devices with CoPd contacts show a larger change of resistance with magnetic field. However, only minor loops are observed, which is explained with domain wall pinning. This is supported by magnetic force microscopy (MFM) measurements, which reveal a complicated bubble and stripe domain pattern.
Simulation of long‐wave phonon (λ > b) scattering at geometric imperfections in nanowires by FDTD method
Authors: Salamatov E. I. 
Published: September 2011

AbstractElementary acts of acoustic phonon scattering in nanowires are studied numerically by the FDTD method. The points of bifurcation of the main waveguide are considered as defects. The particularities of the reflection/transmission coefficient of phonons of different polarizations are studied as a function of the frequency and geometrical parameters of the problem.
Impedance spectroscopy and dielectric behavior in barium strontium titanate–nickel zinc ferrite composites
Authors: Verma Kavita , Sharma Seema 
Published: September 2011

AbstractPolycrystalline composites of (1−x) (Ba0.7Sr0.3TiO3)–x(Ni0.5Zn0.5Fe2O4) (x = 0.00, 0.45, 1.00) were prepared by a modified wet chemical method followed by a high‐temperature sintering process. X‐ray diffraction (XRD) studies at room temperature confirmed the formation of perovskite‐spinel structure. Scanning electron micrographs suggest polycrystalline microstructure with grains of unequal size distributed throughout the samples. Dielectric studies of the composites reveal that the effect of ferrite in the composites is to shift the ferroelectric–non‐ferroelectric phase transition to the higher temperature side with a broadened Curie temperature transition. Complex impedance spectroscopy analysis indicated negative temperature coefficient of resistance behavior, identical to semiconductors. The conduction at low temperature is due to impurities, whereas at higher temperature it is due to polaron hopping.
Origin of ferromagnetism in BaTiO3 nanoparticles
Authors: Bahoosh Safa Golrokh , Trimper Steffen , Wesselinowa Julia M. 
Published: September 2011

AbstractBased on a microscopic approach we demonstrate that the unexpected ferromagnetic properties of BaTiO3 (BTO) or PTO observed recently at room temperature are due to oxygen vacancies at the surface of the nanocrystalline materials. Such vacancies lead to the appearance of Ti3+ or Ti2+ ions with nonzero net spin. The resulting different valence states composed of Ti3+ or Ti2+ offer a nonzero magnetization which decreases with increasing particle size. The system shows a multiferroic behavior below a critical size of the nanoparticles and the related polarization tends to a saturation value when the particle size is enhanced. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Unpacking Firm Exit at the Firm and Industry Levels: The Adaptation and Selection of Firm Capabilities
Authors: Fortune Annetta , Mitchell Will 
Published: September 2011

AbstractEvolutionary theory of business activity studies how firms are selected out of environments in which they do not fit, but most existing work underemphasizes the distinction between acquisition and dissolution as selection processes. We address this gap with a multilevel analysis that investigates how managerial and functional organizational capabilities affect whether struggling firms exit by acquisition or dissolution. We demonstrate that managerial and functional capabilities have heterogeneous effects on selection processes, with managerial capabilities having particularly strong influence on acquisition exits by struggling firms. The work provides a bridge between adaptation and selection views on organizational change; exit by dissolution represents selection of both firms and capabilities, while exit by acquisition represents firm selection but capability adaptation. Copyright © 2011 John Wiley & Sons, Ltd.
Contextualizing agile software development
Authors: Kruchten Philippe 
Published: September 2011

SUMMARYThis paper presents a contextual model for software‐intensive systems development to guide the adoption and adaptation of agile software development practices. This model was found especially useful when the project context departs significantly from the “agile sweet spot”, that is, the ideal conditions in which agile software development practices originated from, and where they are most likely to succeed, “out of the box”. This is the case for large systems, distributed development environment, safety‐critical systems, system requiring a novel architecture, or systems with an unorthodox business model or governance model. Copyright © 2011 John Wiley & Sons, Ltd.