bluuebunny/crossref_metadata_2025 huggingface dataset:
Double-Polarity Selective Area Growth of GaN Metal Organic Vapor Phase Epitaxy by Using Carbon Mask Layers
Authors: Fujita Yohei , Takano Yasushi , Inoue Yoku , Sumiya Masatomo , Fuke Shunro , Nakano Takayuki
Published: July 2013

For nonlinear optical applications using gallium nitride (GaN), periodic inversion of crystallographic orientation (polarity) is required for quasi-phase matching. We developed a novel procedure for designing polarity patterns in GaN using metal organic vapor phase epitaxy (MOVPE), and we used this to fabricate periodic polarity-inverted GaN films. By using a carbon mask for the formation of the selective area, substrate nitriding and mask removal of the selective area were carried out in the GaN epitaxial growth process. In this report, double-polarity selective area growth (DP-SAG) was realized by optimizing the nitriding and mask removal conditions. The interface of the Ga-polarity/N-polarity region became sharp by controlling the V/III ratio at 4700.
Trench-Shaped Defects on AlGaInN Quantum Wells Grown under Different Growth Pressures
Authors: Suzuki Tomoyuki , Kaga Mitsuru , Naniwae Kouichi , Kitano Tsukasa , Hirano Keisuke , Takeuchi Tetsuya , Kamiyama Satoshi , Iwaya Motoaki , Akasaki Isamu
Published: July 2013

We obtained high-quality AlGaInN/GaN quantum wells (QWs) with a 385 nm emission by adding Al sources to GaInN QWs grown at a low growth pressure of 150 mbar. When AlGaInN QWs were grown at a relatively high growth pressure of 400 mbar, a considerable amount of peculiar trench-shaped defects were observed on the surface of the AlGaInN QWs. We found that the trench defects acted as nonradiative centers, leading to low photoluminescence (PL) intensities. Our experiments reveal that a low growth pressure is effective in suppressing the trench defect formation, resulting in high-quality AlGaInN QWs.
AlGaN Ultraviolet A and Ultraviolet C Photodetectors with Very High Specific Detectivity D*
Authors: Albrecht Björn , Kopta Susanne , John Oliver , Kirste Lutz , Driad Rachid , Köhler Klaus , Walther Martin , Ambacher Oliver
Published: July 2013

The development of AlGaN pin photodetectors sensitive in the UV range with different narrow band active regions is reported in this paper. Structures were grown by metalorganic vapor phase epitaxy on (0001) sapphire substrates using three-dimensional GaN as well as high temperature AlN nucleation. Very high specific detectivities of 1×1014cm Hz0.5W-1can be achieved based on optimized growth conditions of undoped and doped AlGaN layers with an Al-content ranging from 0% up to 100%. The crack-free AlGaN layers have edge dislocation densities in the range of 5×109cm-2. Based on the two different nucleation types, pin layer structures were grown and fabricated to UV-A (320 to 365 nm) and UV-C (< 280 nm) photodetectors. The electro-optical performance of these photodetectors measured on-wafer will be presented in this paper, supplemented by the data of a single photodetector chip mounted in a TO 18 package.
Fundamentals of X-ray Diffraction Characterisation of Strain in GaN Based Compounds
Authors: Oehler Fabrice , Vickers Mary E. , Kappers Menno J. , Humphreys Colin J. , Oliver Rachel A.
Published: July 2013

For the characterisation of group III nitrides by X-ray diffraction there are several challenges. In particular: a) reliable reference data on cell parameters of the end members and b) a simple and reliable method to obtain the alloy content of a thin film or multi-quantum layer structure that is fully strained to a template, the latter being fully relaxed or still showing some residual strain. A broad range of reference values for both cell parameters and elastic constants have been reported. In this work, we investigate the cell parameters and strain of (0001) GaN templates grown on sapphire and a bulk ammono GaN sample to derive a coherent set of cell parameters and elastic constants. The values are found to be applicable to a variety of samples, with different crystalline quality (threading dislocation density) or doping level. Subsequently different methods for determining the composition of group III nitride alloys on such strained GaN layers are compared. For simpler analysis, the template is often assumed fully relaxed. We investigate here this approximation and find that standard “relative” method fortuitously provides very good results.
Variation of Growth Rate in InN Molecular-Beam-Epitaxy Growth Using Multiple Radio-Frequency Plasma Cells
Authors: Sato Yuichi , Funaki Kosuke
Published: July 2013

Indium nitride (InN) thin films were grown on (0001) sapphire substrates in a molecular beam epitaxy apparatus with simultaneous operation of multiple radio-frequency nitrogen plasma cells. Growth rates of the obtained InN thin films were compared in terms of the growth temperature, indium Knudsen-cell temperature, and number of nitrogen plasma cells operated during the growth. Growth rate easily increased proportionately with the number of plasma cells without large deteriorations in the properties of the InN thin films.
Enhanced Capability of Photoelectrochemical CO2 Conversion System Using an AlGaN/GaN Photoelectrode
Authors: Deguchi Masahiro , Yotsuhashi Satoshi , Hashiba Hiroshi , Yamada Yuka , Ohkawa Kazuhiro
Published: July 2013

We report significantly improved photosynthesis system based on AlGaN/GaN photochemical process. The resultant energy conversion efficiency is 0.13% which is the same level as that of real plants. The capability of this system is enhanced by high cathode potential due to the reduction of energy loss while utilizing the piezoelectric effect in the AlGaN/GaN heterostructure. The Faradaic efficiency of the CO2 conversion to organic materials is enhanced, accompanied by an increment in photocurrent by modification of the AlGaN/GaN photoelectrode structure and electrolytes. Furthermore, reaction products such as C2H4 and C2H5OH are generated by light illumination alone.
Linear Electro-Optic Effect in Electroreflectance Spectra of AlGaN/InGaN/GaN Light Emitting Diodes Structures
Authors: Avakyants Lev P. , Aslanyan Artem E. , Bokov Pavel Yu. , Chervyakov Anatoly V. , Polozhentsev Kirill Yu.
Published: July 2013

The linear electro-optic effect in InGaN/AlGaN/GaN pn-heterostructures for light emitting diodes, grown by metal–organic chemical vapor deposition on sapphire substrates and flip-chip mounted, was studied by electroreflectance spectroscopy. Interference fringes, whose parameters depend on the DC voltage applied on the pn-junction, were observed in electroreflectance spectra. Data analysis, based on a calculation of the built-in electric field in the depletion layer and linear electro-optic effect, yielded the linear electro-optic coefficient r
13 of 22±6 pm/V for hexagonal In0.12Ga0.88N.
Social science in the era of big data
Authors: González‐Bailón Sandra
Published: July 2013

Digital technologies keep track of everything we do and say while we are online, and we spend online an increasing portion of our time. Databases hidden behind web services and applications are constantly fed with information of our movements and communication patterns, and a significant dimension of our lives, quantified to unprecedented levels, gets stored in those vast online repositories. This article considers some of the implications of this torrent of data for social science research, and for the types of questions we can ask of the world we inhabit. The goal of the article is twofold: to explain why, in spite of all the data, theory still matters to build credible stories of what the data reveal; and to show how this allows social scientists to revisit old questions at the intersection of new technologies and disciplinary approaches. The article also considers how Big Data research can transform policymaking, with a focus on how it can help us improve communication and governance in policy‐relevant domains.
Psephological investigations: Tweets, votes, and unknown unknowns in the republican nomination process
Authors: Jensen Michael J. , Anstead Nick
Published: July 2013

This paper analyzes the utility of using information contained within Twitter posts in predicting electoral outcomes. Particularly, we are interested in patterns in Twitter communications that can help explain differences between published opinion polls and the actual vote. We consider three categories of models. The first is a mentions model that examines the correspondence between the prevalence of communications about a candidate and electoral outcomes. The second series of models treat Twitter similar to a prediction market, aggregating not candidate preferences but predictions of the electoral result. Last, we consider whether the rediffusion of tweets about a candidate is a reliable predictor of the candidate's performance. The results find inconsistent support for the predictive value of Twitter mentions as an estimate of the overall vote, but these communications provide some evidence of otherwise undetected shifts in momentum with respect to the aggregated predictions of candidate performance and message rediffusion via retweets containing information about a particular candidate. Given the nature of the information extractable, these data are most sensitive to detecting changes in momentum.
Big data  + politics = open data: The case of health care data in England
Authors: Keen Justin , Calinescu Radu , Paige Richard , Rooksby John
Published: July 2013

There is a great deal of enthusiasm about the prospects for Big Data held in health care systems around the world. Health care appears to offer the ideal combination of circumstances for its exploitation, with a need to improve productivity on the one hand and the availability of data that can be used to identify opportunities for improvement on the other. The enthusiasm rests on two assumptions. First, that the data sets held by hospitals and other organizations, and the technological infrastructure needed for their acquisition, storage, and manipulation, are up to the task. Second, that organizations outside health care systems will be able to access detailed datasets. We argue that both assumptions can be challenged. The article uses the example of the National Health Service in England to identify data, technology, and information governance challenges. The public acceptability of third party access to detailed health care datasets is, at best, unclear.
The voodoo doll task: Introducing and validating a novel method for studying aggressive inclinations
Authors: DeWall C. Nathan , Finkel Eli J. , Lambert Nathaniel M. , Slotter Erica B. , Bodenhausen Galen V. , Pond Richard S. , Renzetti Claire M. , Fincham Frank D.
Published: July 2013

Aggression pervades modern life. To understand the root causes of aggression, researchers have developed several methods to assess aggressive inclinations. The current article introduces a new behavioral method—the voodoo doll task (VDT)—that offers a reliable and valid trait and state measure of aggressive inclinations across settings and relationship contexts. Drawing on theory and research on the law of similarity and magical beliefs (Rozin, Millman, & Nemeroff [1986], Journal of Personality and Social Psychology, 50, 703−712), we propose that people transfer characteristics of a person onto a voodoo doll representing that person. As a result, causing harm to a voodoo doll by stabbing it with pins may have important psychological similarities to causing actual harm to the person the voodoo doll represents. Nine methodologically diverse studies (total N = 1,376) showed that the VDT had strong reliability, construct validity, and convergent validity. Discussion centers on the importance of magical beliefs in understanding the causes of aggressive inclinations. Aggr. Behav. 39:419–439, 2013. © 2013 Wiley Periodicals, Inc.
Testing predictions from the male control theory of men's partner violence
Authors: Bates Elizabeth A. , Graham‐Kevan Nicola , Archer John
Published: July 2013

The aim of this study was to test predictions from the male control theory of intimate partner violence (IPV) and Johnson's [Johnson, M. P. (1995).Journal of Marriage and the Family, 57, 282–294] typology. A student sample (N = 1,104) reported on their use of physical aggression and controlling behavior, to partners and to same‐sex non‐intimates. Contrary to the male control theory, women were found to be more physically aggressive to their partners than men were, and the reverse pattern was found for aggression to same‐sex non‐intimates. Furthermore, there were no substantial sex differences in controlling behavior, which significantly predicted physical aggression in both sexes. IPV was found to be associated with physical aggression to same‐sex non‐intimates, thereby demonstrating a link with aggression outside the family. Using Johnson's typology, women were more likely than men to be classed as “intimate terrorists,” which was counter to earlier findings. Overall, these results do not support the male control theory of IPV. Instead, they fit the view that IPV does not have a special etiology, and is better studied within the context of other forms of aggression. Aggr. Behav. 40:42–55, 2014. © 2013 Wiley Periodicals, Inc.
Highly Fluorescent Nanodiamonds Protein‐Functionalized for Cell Labeling and Targeting
Authors: Chang Be‐Ming , Lin Hsin‐Hung , Su Long‐Jyun , Lin Wen‐Der , Lin Ruey‐Jen , Tzeng Yan‐Kai , Lee Reiko T. , Lee Yuan C. , Yu Alice L. , Chang Huan‐Cheng
Published: July 2013

Fluorescent nanodiamond (FND) is attracting much attention as a bioimaging agent because of its inherent biocompatibility and superior optical properties (e.g., excellent photostability and far‐red emission). However, for practical use in life science research, some issues such as higher brightness and ease of bioconjugation have to be solved. Here, it is shown that the 100‐nm FND particles fabricated by using nitrogen‐rich type Ib diamonds and high‐energy proton irradiation are highly fluorescent and readily functionalizable with proteins for biological applications. In the first approach, acid‐treated FND is noncovalently coated with glycoproteins or neoglycoproteins (i.e., proteins chemically modified with multiple sugar residues) for targeting hepatocytes via carbohydrate receptors. In the second approach, FND is first PEGylated and then covalently conjugated with streptavidin, to which biotin‐labeled antibodies of interest are linked. High targeting specificity of the bioconjugated FND is demonstrated with the human hepatoma cell line, HepG2, and breast cancer cell lines, ASB145‐1R, MCF‐7, and MDA‐MB‐231 cells. These approaches should be widely applicable to a variety of situations for specific targeting and labeling of cells.
Biofunctional Micropatterning of Thermoformed 3D Substrates
Authors: Waterkotte Björn , Bally Florence , Nikolov Pavel M. , Waldbaur Ansgar , Rapp Bastian E. , Truckenmüller Roman , Lahann Jörg , Schmitz Katja , Giselbrecht Stefan
Published: July 2013

Mimicking the in vivo microenvironment of cells is a challenging task in engineering in vitro cell models. Surface functionalization is one of the key components providing biochemical cues to regulate the interaction between cells and their substrate. In this study, two different approaches yield biofunctional surface patterns on thermoformed polymer films. The first strategy based on maskless projection lithography enables the creation of grayscale patterns of biological ligands with a resolution of 7.5 μm in different shapes on a protein layer adsorbed on a polymer film. In the second strategy, polymer films are micropatterned with different functional groups via chemical vapor deposition polymerization. After thermoforming, both types of pattern can be decorated with proteins either by affinity binding or covalent coupling. The 3D microstructures retain the biofunctional patterns as demonstrated by selective cell adhesion and growth of L929 mouse fibroblasts. This combination of functional micropatterning and thermoforming offers new perspectives for the design of 3D cell culture platforms.
A Flexible Reduced Graphene Oxide Field‐Effect Transistor for Ultrasensitive Strain Sensing
Authors: Trung Tran Quang , Tien Nguyen Thanh , Kim Doil , Jang Mi , Yoon Ok Ja , Lee Nae‐Eung
Published: July 2013

A new kind of flexible strain sensor based on a reduced graphene oxide field‐effect transistor (rGO FET) with ultrasensitivity, stability, and repeatability for the detection of tensile and compressive strains is demonstrated. The novelty of the rGO FET strain sensor is the incorporation of a rGO channel as a sensing layer in which the electrical resistance can be greatly modified upon application of an extremely low level of strain resulting in an intrinsically amplified sensing signal. The rGO FET device is ultrasensitive to extremely low strain levels, as low as 0.02%. Due to weak coupling between adjacent nanosheets, therefore, upon applying small levels of strain into the rGO thin film, a modulation of the internanosheet resistance (Rinter) is expected, inducing a large change in the transconductance of the rGO FET. Using a simple printing and self‐assembly process, the facile fabrication of an rGO FET array over a large area is also demonstrated. In addition, the device can detect small and rapid physical movements of the human body.
Enhanced Tumor Accumulation of Sub‐2 nm Gold Nanoclusters for Cancer Radiation Therapy
Authors: Zhang Xiao‐Dong , Chen Jie , Luo Zhentao , Wu Di , Shen Xiu , Song Sha‐Sha , Sun Yuan‐Ming , Liu Pei‐Xun , Zhao Jing , Huo Shuaidong , Fan Saijun , Fan Feiyue , Liang Xing‐Jie , Xie Jianping
Published: July 2013

A new type of metabolizable and efficient radiosensitizers for cancer radiotherapy is presented by combining ultrasmall Au nanoclusters (NCs, <2 nm) with biocompatible coating ligands (glutathione, GSH). The new nanoconstruct (GSH‐coated Au25 NCs) inherits attractive features of both the Au core (strong radiosensitizing effect) and GSH shell (good biocompatibility). It can preferentially accumulate in tumor via the improved EPR effect, which leads to strong enhancement for cancer radiotherapy. After the treatment, the small‐sized GSH‐Au25 NCs can be efficiently cleared by the kidney, minimizing any potential side effects due to the accumulation of Au25 NCs in the body.
Elastomeric Coating of Exfoliated Graphite Nanoplatelets with Amine‐Terminated Poly(butadiene‐co‐acrylonitrile): Characterization and Its Epoxy Toughening Effect
Authors: Cho Donghwan , Hwang Jeong Hyeon
Published: July 2013

In the present study, exfoliated graphite nanoplatelets (EGN), which were prepared by means of microwave and ultrasonic processes from graphite intercalation compounds, were coated with a liquid rubber amine‐terminated poly(butadiene‐co‐acrylonitrile) (ATBN) at various concentrations via ultrasonic and deep‐freezing methods. The presence of ATBN coating on EGN particles was characterized by using multiple analytical tools such as X‐ray photoelectron spectroscopy, energy dispersive X‐ray spectroscopy, elemental analysis, X‐ray diffractometer, thermogravimetric analyzer, and scanning electron microscope. The level of ATBN coating of the EGN particles strongly depended on the coating concentration, and it was clearly demonstrated. The characterization results were consistent with each other, indicating that the elastomeric coating of EGN with ATBN was performed successfully. The 1 wt% EGN coated with 10 wt% ATBN incorporated into epoxy increased the toughness of epoxy by 18%. It turns out that the elastomeric coating of EGN with ATBN effectively contributed to toughen epoxy with a very small amount of 0.1 wt% ATBN compared to the epoxy. © 2013 Wiley Periodicals, Inc. Adv Polym Technol 2013, 32, 21366; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.21366
In Situ Reversible Addition–Fragmentation Chain Transfer Polymerization of Styrene in the Presence of MCM‐41 Nanoparticles: Comparing “Grafting from” and “Grafting through” Approaches
Authors: Sarsabili Mohammadreza , Parvini Mehdi , Salami‐Kalajahi Mehdi , Ganjeh‐Anzabi Pejman
Published: July 2013

The preparation of polystyrene/MCM‐41 nanocomposites was carried out by “grafting from” and “grafting through” approaches and in the presence of unmodified MCM‐41, using reversible addition–fragmentation chain transfer (RAFT) polymerization. The MCM‐41 was modified by attaching S‐dodecyl‐S′‐(α,α′‐dimethyl‐α′′‐acetic acid)trithiocarbonate (DDMAT) as the RAFT agent and methacrylate group using 3‐methacryloxypropyldimethylchlorosilane. The kinetics of styrene RAFT polymerization by different approaches was compared with the model polymerization mediated by free DDMAT. The quantity of the grafted chain grown from the surface and inside of the pores of MCM‐41 and free polymer chains in bulk was determined by thermogravimetric analysis. The molecular weight of the produced polymer chains increased linearly with the monomer conversion for three methods. The gel permeation chromatography showed that the molecular weight of grafted and free polymer chains in the “grafting from” approach is higher than other methods, and molecular weight distributions were relatively narrower whereas the rate of polymerization for “grafting from” was higher. © 2013 Wiley Periodicals, Inc. Adv Polym Technol 2013, 32, 21372; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.21372
Synthesis of Hyperbranched Multiarm Star Block Copolymers and Their Application as a Drug‐Delivery System
Authors: Xia Li , Zhou Zhiping , Dai Jiangdong
Published: July 2013

A novel hyperbranched multiarm star block copolymers was synthesized. The atom transfer radical polymerization initiators were anchored on the surfaces by the reaction of amino‐functionalized silica modified by 3‐aminopropyltriethoxysilane with α‐bromoisobutyryl bromide. The composites (SNs‐g‐HPCMS‐b‐PHEMA‐b‐PNIPAAm) with silica nano particles as core and hyperbranched star block copolymers as arms was prepared by iron(III)‐mediated surface‐initiated polymerization with FeCl3·6H2O as catalyst, triphenylphosphine as ligand, ascorbic acid as reducing agent, N,N‐dimethylformamide as solvent, and 4‐chloromethylstyrene, 2‐hydroxyethylmethacrylate, and N‐isopropylacrylaminde as monomers, respectively. The resultant products were characterized by Fourier‐transform infrared spectroscopy, N2 adsorption/desorption measurements, thermogravimetric analysis, differential scanning calorimeter, and transmission electron micrographs. With aspirin as the model drug, the drug‐release behavior of the hybrid materials was studied. The release behavior could be controlled by the temperature, which will have potential applications in biomedicine and biotechnology. © 2013 Wiley Periodicals, Inc. Adv Polym Technol 2013, 32, 21375; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.21375
Challenges in nucleic acid‐lipid films for transfection
Authors: Perry Sarah L. , Neumann Surekha G. , Neumann Thorsten , Cheng Karen , Ni Jennifer , Weinstein John R. , Schaffer David V. , Tirrell Matthew
Published: July 2013

The use of surface‐based methods for the delivery of therapeutics has recently generated increasing interest. These platforms have tremendous potential to minimize detrimental side effects associated with systemic delivery by localizing the therapeutic vehicle, and thus provide higher local doses for improved efficacy. Cationic lipids are one of the most commonly used synthetic carriers for the delivery of genetic cargo, such as DNA and RNA. However, reports on the use of lipid‐based films for gene delivery are scarce. Here we investigate the use of a lipid‐based film for the in vitro delivery of plasmid DNA. Solid DNA‐lipid films show very low levels of transfection, while identical complexes prepared for bolus delivery provide high levels of transfection when used directly. We investigate the mechanism, whereby the activity of these solid‐state films is lost and suggest methods for circumventing these challenges and restoring the efficacy of these films as gene delivery platforms. © 2013 American Institute of Chemical Engineers AIChE J, 59: 3203–3213, 2013
Nonlinear dynamics of ion concentration polarization in porous media: The leaky membrane model
Authors: Dydek E. Victoria , Bazant Martin Z.
Published: July 2013

The conductivity of highly charged membranes is nearly constant, due to counterions screening pore surfaces. Weakly charged porous media, or “leaky membranes,” also contain a significant concentration of coions, whose depletion at high current leads to ion concentration polarization and conductivity shock waves. To describe these nonlinear phenomena in the absence of electro‐osmotic flow, a simple leaky membrane model is formulated, based on macroscopic electroneutrality and Nernst–Planck ionic fluxes. The model is solved in cases of unsupported binary electrolytes: steady conduction from a reservoir to a cation‐selective surface, transient response to a current step, steady conduction to a flow‐through porous electrode, and steady conduction between cation‐selective surfaces in cross flow. The last problem is motivated by separations in leaky membranes, such as shock electrodialysis. The article begins with a tribute to Neal Amundson, whose pioneering work on shock waves in chromatography involved similar mathematics. © 2013 American Institute of Chemical Engineers AIChE J, 59: 3539–3555, 2013
Decreased survival in normal karyotype AML with single‐nucleotide polymorphisms in genes encoding the AraC metabolizing enzymes cytidine deaminase and 5′‐nucleotidase
Authors: Falk Ingrid Jakobsen , Fyrberg Anna , Paul Esbjörn , Nahi Hareth , Hermanson Monica , Rosenquist Richard , Höglund Martin , Palmqvist Lars , Stockelberg Dick , Wei Yuan , Gréen Henrik , Lotfi Kourosh
Published: July 2013

De novo acute myeloid leukemia with normal karyotype (NK‐AML) comprises a large group of patients with no common cytogenetic alterations and with a large variation in treatment response. Single‐nucleotide polymorphisms (SNPs) in genes related to the metabolism of the nucleoside analogue AraC, the backbone in AML treatment, might affect drug sensitivity and treatment outcome. Therefore, SNPs may serve as prognostic biomarkers aiding clinicians in individualized treatment decisions, with the aim of improving patient outcomes. We analyzed polymorphisms in genes encoding cytidine deaminase (CDA 79A>C rs2072671 and −451C>T rs532545), 5′‐nucleotidase (cN‐II 7A>G rs10883841), and deoxycytidine kinase (DCK 3′UTR 948T>C rs4643786) in 205 de novo NK‐AML patients. In FLT3‐internal tandem duplication (ITD)‐positive patients, the CDA 79C/C and −451T/T genotypes were associated with shorter overall survival compared to other genotypes (5 vs. 24 months, P < 0.001 and 5 vs. 23 months, P = 0.015, respectively), and this was most pronounced in FLT3‐ITD‐positive/NPM1‐positive patients. We observed altered in vitro sensitivity to topoisomerase inhibitory drugs, but not to nucleoside analogues, and a decrease in global DNA methylation in cells carrying both CDA variant alleles. A shorter survival was also observed for the cN‐II variant allele, but only in FLT3‐ITD‐negative patients (25 vs. 31 months, P = 0.075). Our results indicate that polymorphisms in genes related to nucleoside analog drug metabolism may serve as prognostic markers in de novo NK‐AML. Am. J. Hematol. 88:1001–1006, 2013. © 2013 Wiley Periodicals, Inc.
The changing incidence of primary central nervous system lymphoma is driven primarily by the changing incidence in young and middle‐aged men and differs from time trends in systemic diffuse large B‐cell non‐Hodgkin's lymphoma
Authors: O'Neill Brian Patrick , Decker Paul A. , Tieu Christina , Cerhan James R.
Published: July 2013

There has been an overall decline in the United States incidence of Primary CNS Lymphoma (PCNSL) from 1998 to 2008. This study's intent was to characterize the cohorts contributing to it. First, calculated the PCNSL incidence rates from nine Surveillance, Epidemiology, and End Results (SEER) registries for time period 1973 to 2008. Second, examined the time trends overall and by age and gender. Third, used 1992–2008 SEER data from the same registries to obtain overall trends for diffuse large B‐cell lymphoma (DLBCL). Last, rates were age‐adjusted to the 2000 US standard population and reported per 100,000 person‐years. Rates continued to increase in women at all ages and men aged 65 and older. In men aged 20–39 and 40–64 years incidence rates peaked in 1995 and then declined dramatically, stabilizing after 1998. The trends in the incidence of PCNSL over this time frame were significantly different from DLBCL for ages 20–39 (P < 0.001) and 40–64 (P < 0.001) years but were not different for the 65 years and older age group (P = 0.99). The overall PCNSL incidence rate declined since 1995 and was driven primarily by the changing incidence in young and middle‐aged men. The rate has continued to increase in men aged 65 years and older and in women. The trends in incidence in the younger age groups over this time period did not parallel those observed for DLBCL. Am. J. Hematol. 88:997–1000, 2013. © 2013 Wiley Periodicals, Inc.
Thrombin generation and procoagulant phospholipids in patients with essential thrombocythemia and reactive thrombocytosis
Authors: Mignon I. , Grand F. , Boyer F. , Hunault‐Berger M. , Hamel J.F. , Macchi L.
Published: July 2013

Thrombocytosis is a commonly encountered clinical scenario and can be either a secondary process (reactive thrombocytosis), or due to clonal disorder (i.e., essential thrombocythemia). This distinction is important as it carries implications for evaluation, prognosis and treatment. In this study we compared procoagulant potential in essential thrombocythemia and reactive thrombocytosis by measuring the thrombin generation and the level of circulating procoagulant phospholipids with functional tests. Twenty nine patients with essential thrombocythemia and 24 with reactive thrombocytosis were studied. Thrombin generation was determined by calibrated automated thrombography. Procoagulant phospholipids were detected by a chronometric standardised method (STA‐Procoag‐PPL). Patients with reactive thrombocytosis had a longer lag time, higher endogenous thrombin potential, peak of thrombin generation and velocity index than patients with essential thrombocythemia. The level of circulating procoagulant phospholipids was increased in patients with essential thrombocythemia as observed with the procoagulant phospholipids assay. Each parameter was analysed using ROC curves. Highest areas under the curve (AUC) were found for lag time and procoagulant phospholipids ratio (0.817 and 0.853, respectively), associated with high negative predictive value for ET (92.3% and 80%, respectively). In conclusion, patients with essential thrombocythemia and reactive thrombocytosis displayed significant differences in terms of thrombin generation and levels of procoagulant phospholipids. Among these parameters, lag time and procoagulant phospholipids ratio could help to differentiate between reactive thrombocytosis and essential thrombocythemia patients. Am. J. Hematol. 88:1007–1011, 2013. © 2013 Wiley Periodicals, Inc.
Elektroaktive Polymere: Entwicklungen und Perspektiven dielektrischer Elastomere
Authors: Biggs James , Danielmeier Karsten , Hitzbleck Julia , Krause Jens , Kridl Tom , Nowak Stephan , Orselli Enrico , Quan Xina , Schapeler Dirk , Sutherland Will , Wagner Joachim
Published: July 2013

Wir präsentieren einen kurzen Rückblick über die Entwicklung und Anwendung dielektrischer Elastomere. In den vergangenen zehn Jahren hat die Bedeutung dieser Polymerklasse stetig zugenommen. Inzwischen setzen sich erste Produkte auf dem Markt durch, und weitere Anwendungen stehen vor der Markteinführung.
Electroactive Polymers: Developments of and Perspectives for Dielectric Elastomers
Authors: Biggs James , Danielmeier Karsten , Hitzbleck Julia , Krause Jens , Kridl Tom , Nowak Stephan , Orselli Enrico , Quan Xina , Schapeler Dirk , Sutherland Will , Wagner Joachim
Published: July 2013

We present the development and applications of dielectric elastomers. For the last 10 years the significance of this class of polymers has risen as more applications seem possible and first products have been commercialized.
Thermal aging of bentonite‐filled ethylene propylene diene monomer composites
Authors: Muniyadi Mathialagan , Ismail Hanafi
Published: July 2013

Bentonite‐filled ethylene propylene diene monomer (EPDM/Bt) composites were prepared using two roll mill compounding method and the effect of Bt loading on the thermal aging, swelling resistance and crosslink density of EPDM/Bt composites were studied. The effect of in situ addition of different silane coupling agents (SCAs) on the above properties at optimum Bt loading of EPDM/Bt composite was also investigated. Thermal aging test results show that the tensile strength and tensile modulus at 100% elongation (M100) increase initially for 2 days aged composites and decrease slightly after 4 days of aging, meanwhile the elongation at break (Eb) decrease gradually with aging period as compared to the unaged composites. Upon aging, swelling resistance increase initially indicating increased crosslink density of EPDM/Bt composite due to post‐curing and reduced after 4 days of aging due to crosslink destruction and EPDM chain scissioning. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4419–4427, 2013
Synthesis and Biological Evaluation of a Novel Series of 6,8‐Dibromo‐4(3H)quinazolinone Derivatives as Anticancer Agents
Authors: Ahmed Marwa F. , Youns Mahmoud
Published: July 2013

Three novel series of 6,8‐dibromo‐4(3H)quinazolinone derivatives were synthesized. Some of the novel quinazolinone derivatives were tested for their antitumor activity against the human breast carcinoma cell line MCF‐7. Compounds XIIIb, IX, XIVd, XIVb, XIVe, XIIIa, XIVc, XVc, and XIVa exerted powerful cytotoxic effects against the MCF7 cells, with very low IC50 values compared to doxorubicin (positive control). The IC50 values were 1.7, 1.8, 1.83, 5.4, 6.84, 10.8, 13.9, 15.7, and 29.6 µg/mL, respectively.
Medical student attitudes to the autopsy and its utility in medical education: A brief qualitative study at one UK medical school
Authors: Bamber Andrew R. , Quince Thelma A. , Barclay Stephen I.G. , Clark John D.A. , Siklos Paul W.L. , Wood Diana F.
Published: July 2013

Attending postmortems enables students to learn anatomy and pathology within a clinical context, provides insights into effects of treatment and introduces the reality that patients die. Rates of clinical autopsies have declined and medical schools have cut obligatory autopsy sessions from their curricula making it difficult to assess medical student perceptions of, and attitudes towards, the educational value of autopsy. Our aim was to investigate these perceptions by designing a brief qualitative study comprising nominal technique and focus group discussions with Cambridge Graduate Course students, all of whom had attended autopsies. Three general themes emerged from the focus group discussions: the value of autopsy as a teaching tool and ways the experience could be improved, the initial impact of the mortuary and the autopsy itself, and the “emerging patient”—an emotional continuum running from cadaver to autopsy subject and living patient. Educational benefits of autopsy‐based teaching included greater understanding of anatomy and physiology, greater appreciation of the role of other health care professionals and an enhanced appreciation of psycho‐social aspects of medical practice. Students suggested improvements for ameliorating the difficult emotional consequences of attendance. We conclude that autopsy‐based teaching represents a low‐cost teaching technique which is highly valued by students and has application to many diverse medical specialties and skills. However, careful preparation and organization of sessions is required to maximize potential educational benefits and reduce any negative emotional impact. Anat Sci Educ 7: 87–96. © 2013 American Association of Anatomists.
Anatomy adventure: A board game for enhancing understanding of anatomy
Authors: Anyanwu Emeka G.
Published: July 2013

Certain negative factors such as fear, loss of concentration and interest in the course, lack of confidence, and undue stress have been associated with the study of anatomy. These are factors most often provoked by the unusually large curriculum, nature of the course, and the psychosocial impact of dissection. As a palliative measure, Anatomy Adventure, a board game on anatomy was designed to reduce some of these pressures, emphasize student centered and collaborative learning styles, and add fun to the process of learning while promoting understanding and retention of the subject. To assess these objectives, 95 out of over 150 medical and dental students who expressed willingness to be part of the study were recruited and divided into a Game group and a Non‐game group. A pretest written examination was given to both groups, participants in the Game group were allowed to play the game for ten days, after which a post‐test examination was also given. A 20‐item questionnaire rated on a three‐point scale to access student's perception of the game was given to the game group. The post‐test scores of the game group were significantly higher (P < 0.05) than those of the non‐game counterparts. Also the post‐test score of the game based group was significantly better (P < 0.05) than their pretest. The students in their feedback noted in very high proportions that the game was interesting, highly informative, encouraged team work, improved their attitude, and perception to gross anatomy. Anat Sci Educ 7: 153–160. © 2013 American Association of Anatomists.
ATP‐driven molecular chaperone machines
Authors: Clare Daniel K. , Saibil Helen R.
Published: July 2013

This review is focused on the mechanisms by which ATP binding and hydrolysis drive chaperone machines assisting protein folding and unfolding. A survey of the key, general chaperone systems Hsp70 and Hsp90, and the unfoldase Hsp100 is followed by a focus on the Hsp60 chaperonin machine which is understood in most detail. Cryo‐electron microscopy analysis of the E. coli Hsp60 GroEL reveals intermediate conformations in the ATPase cycle and in substrate folding. These structures suggest a mechanism by which GroEL can forcefully unfold and then encapsulate substrates for subsequent folding in isolation from all other binding surfaces. © 2013 The Authors. Published by Wiley Periodicals, Inc. Biopolymers 99: 846–859, 2013.
Relationship Between Sustainable Development and Financial Performance: International Empirical Research
Authors: Martínez‐Ferrero Jennifer , Frías‐Aceituno José Valeriano
Published: July 2013

The aim of this paper is to clarify the relationship between companies' sustainable behavior and their financial performance (FP), which has been studied for several years without reaching a consensus on the effect and the direction of it. Hypotheses are tested for an unbalanced sample of 1960 multinational non‐financial listed companies from 25 countries and one administrative region for the period between 2002 and 2010. Due to the use of an international database and the differences among countries, it is possible to observe divergence between institutional settings. For this reason, a corporate governance system (Anglo‐Saxon, Germanic, Latin and Asian) is used as characteristic of the macro‐environment. Results obtained via the generalized method of moments estimator allow us to support the existence of a positive bidirectional relationship between corporate social responsibility and FP, evidencing the existence of a synergistic circle. The use of market value indicated that investors are able to identify economic, social and environmental practices generating a positive effect on FP. These relationships differ between corporate governance systems, due to the specific characteristics of each system. Findings are robust for each sustainable sub‐index (society, human rights, environmental and board). Copyright © 2013 John Wiley & Sons, Ltd and ERP Environment
Input, Output, and Environmental Management Productivity: Effects on Firm Performance
Authors: Lannelongue Gustavo , Gonzalez‐Benito Javier , Gonzalez‐Benito Oscar
Published: July 2013

Firms invest considerable resources to control any of their operations that may have environmental impacts in an attempt to reduce such impacts but also generate economic value. Various studies of the basic creation or destruction of monetary value through environmental performance offer contradictory evidence. Therefore, the present study proposes a new definition of environmental management as the transformation of inputs (resources assigned) into outputs (valuable results). Both inputs and outputs should be taken into account to explain financial outcomes; further consideration should also include a third aspect, namely, ‘environmental management productivity’, which describes the relationship between the outputs and inputs of environmental management. Empirical analyses of Spanish firms with a certified environmental management system subject to the European Union's CO2 emissions trading system provide evidence that all three aspects must be considered in combination to achieve a more comprehensive view of the impact of environmental management on financial performance. Copyright © 2013 John Wiley & Sons, Ltd and ERP Environment
Characterization of hERG1 channel role in mouse colorectal carcinogenesis
Authors: Fiore Antonella , Carraresi Laura , Morabito Angela , Polvani Simone , Fortunato Angelo , Lastraioli Elena , Femia Angelo P. , De Lorenzo Emanuele , Caderni Giovanna , Arcangeli Annarosa
Published: July 2013

The human ether‐à‐go‐go‐related gene (hERG)1 K+ channel is upregulated in human colorectal cancer cells and primary samples. In this study, we examined the role of hERG1 in colorectal carcinogenesis using two mouse models: adenomatous polyposis coli (Apcmin/+) and azoxymethane (AOM)‐treated mice. Colonic polyps of Apcmin/+ mice overexpressed mERG1 and their formation was reverted by the hERG1 blocker E4031. AOM was applied to either hERG1‐transgenic (TG) mice, which overexpress hERG1 in the mucosa of the large intestine, or wild‐type mice. A significant increase of both mucin‐depleted foci and polyps in the colon of hERG1‐TG mice was detected. Both the intestine of TG mice and colonic polyps of Apcmin/+ showed an upregulation of phospho‐Protein Kinase B (pAkt)/vascular endothelial growth factor (VEGF‐A) and an increased angiogenesis, which were reverted by treatment with E4031. On the whole, this article assigns a relevant role to hERG1 in the process of in vivo colorectal carcinogenesis.
Dicopper(II) Metallacyclophanes with Electroswitchable Polymethyl‐Substituted para‐Phenylene Spacers
Authors: Ferrando‐Soria Jesús , Castellano María , Ruiz‐García Rafael , Cano Joan , Julve Miguel , Lloret Francesc , Ruiz‐Pérez Catalina , Pasán Jorge , Cañadillas‐Delgado Laura , Armentano Donatella , Journaux Yves , Pardo Emilio
Published: July 2013

Double‐stranded anionic dinuclear copper(II) metallacyclic complexes of the paracyclophane type [Cu2L2]4− have been prepared by the CuII‐mediated self‐assembly of different para‐phenylenebis(oxamato) bridging ligands with either zero‐, one‐, or four‐electron‐donating methyl substituents (L=N,N′‐para‐phenylenebis(oxamate) (ppba; 1), 2‐methyl‐ N,N′‐para‐phenylenebis(oxamate) (Meppba; 2), and 2,3,5,6‐tetramethyl‐ N,N′‐para‐phenylenebis(oxamate) (Me4ppba; 3)). These complexes have been isolated as their tetra‐n‐butylammonium (1 a–3 a), lithium(I) (1 b–3 b), and tetraphenylphosphonium salts (1 c–3 c). The X‐ray crystal structures of 1 a and 3 c show a parallel‐displaced π‐stacked conformation with a smaller deviation from perpendicularity between the two benzene rings and the basal planes of the square planar CuII ions when increasing the number of methyl substituents (average dihedral angles (ϕ) of 58.72(7) and 73.67(5)° for 1 a and 3 c, respectively). Variable‐temperature (2.0–300 K) magnetic‐susceptibility measurements show an overall increase of the intramolecular antiferromagnetic coupling with the number of methyl substituents onto the para‐phenylene spacers (−J=75–95, 100–124, and 128–144 cm−1 for 1 a–c, 2 a–c, and 3 a–c, respectively; H=−JS1×S2). Cyclic voltammetry (CV) measurements show a reversible one‐electron oxidation of the double polymethyl‐substituted para‐phenylenediamidate bridging skeleton at a relatively low formal potential that decreases with the number of methyl substituents (E1=+0.33, +0.24, and +0.15 V vs. SCE for 1–3, respectively). The monooxidized dicopper(II) π‐radical cation species 3′ prepared by the chemical oxidation of 3 with bromine exhibits intense metal‐to‐ligand charge‐transfer (MLCT) transitions in the visible and near‐IR (λmax=595 and 875 nm, respectively) regions together with a rhombic EPR signal with a seven‐line splitting pattern due to hyperfine coupling with the nuclear spin of the two CuII ions. Density functional (DF) calculations for 3′ evidence a characteristic iminoquinonoid‐type short‐long‐short alternating sequence of CN and CC bonds for both tetramethyl‐para‐phenylenediamidate bridges and a large amount of spin density of negative sign mainly delocalized along each of the four benzene C atoms directly attached to the amidate N atoms, which is in agreement with a fully delocalized π‐stacked monoradical ligand description. Hence, the spins of the two CuII ions (SCu=1/2) that are antiparallel aligned in 3 (OFF state) become parallel in 3′ (ON state). Further developments may be then envisaged for this new permethylated dicopper(II) paracyclophane with a redox noninnocent ligand as a prototype for molecular magnetic electroswitch.
Diazadithia[7]helicenes: Synthetic Exploration, Solid‐State Structure, and Properties
Authors: Waghray Deepali , Cloet Arvid , Van Hecke Kristof , Mertens Stijn F. L. , De Feyter Steven , Van Meervelt Luc , Van der Auweraer Mark , Dehaen Wim
Published: July 2013

Diazadithia[7]helicenes were synthesized from the readily available building block ethyl 7‐chloro‐8‐formylthieno[3,2‐f]quinoline‐2‐carboxylate by a Wittig reaction–photocyclization strategy. The helicene core was functionalized by nucleophilic aromatic substitution with a variety of nucleophiles (e.g., O‐, N‐, and C‐centered) and palladium‐catalyzed reactions such as Suzuki coupling and Buchwald–Hartwig amination. Racemization studies confirmed that the enantiopure forms of these [7]helicenes are conformationally stable compared to their lower analogues. The solid‐state structures of the novel diazadithia[7]helicenes were determined by single‐crystal X‐ray diffraction. The crystal structures of these azathia[7]helicenes show columnar stacking in antiparallel fashion. The HOMO–LUMO gaps of the new compounds were determined on the basis of electrochemical and optical measurements.
Design and Synthesis of a γ1β8‐Cyclodextrin Oligomer: A New Platform with Potential Application as a Dendrimeric Multicarrier
Authors: Barge Alessandro , Caporaso Marina , Cravotto Giancarlo , Martina Katia , Tosco Paolo , Aime Silvio , Carrera Carla , Gianolio Eliana , Pariani Giorgio , Corpillo Davide
Published: July 2013

We report the synthesis and characterization of a water‐soluble, star‐shaped macromolecular platform consisting of eight β‐cyclodextrin (β‐CD) units anchored to the narrower rim of a γ‐CD core through bis(triazolyl)alkyl spacers. The efficient synthetic protocol is based on the microwave (MW)‐promoted Cu‐catalyzed 1,3‐dipolar cycloaddition of CD monoazides to CD monoacetylenes. The ligand‐hosting capability of the construct has been assessed by relaxometric titration and nuclear magnetic relaxation dispersion (NMRD) profiling, which showed it to be good, and this was supported by molecular dynamics simulations. To demonstrate the feasibility of obtaining supramolecular structures with high hosting ability, we designed a dimeric platform, formed by joining two nonamers through the γ‐CD cores through a bis(lithocholic acid) linker. With a view to the potential biological applications, cytotoxicity and extent of binding to human serum albumin were assessed. The properties of this dendrimeric multicarrier make it suitable for pharmaceutical and diagnostic purposes, ranging from targeted drug delivery to molecular imaging.