bluuebunny/crossref_metadata_2025_split huggingface dataset:
Increased conversion efficiency in cadmium telluride photovoltaics by luminescent downshifting with quantum dot/poly(methyl methacrylate) films
Authors: Hodgson Simon D. , Brooks William S. M. , Clayton Andrew J. , Kartopu Giray , Lamb Daniel A. , Barrioz Vincent , Irvine Stuart J. C. 
Published: August 2013

AbstractCommercially available quantum dots have been encapsulated in a poly(methyl methacrylate) film and used as a luminescent downshifting layer on cadmium sulfide/cadmium telluride photovoltaic devices. Application of these films has resulted in a relative improvement to the short‐circuit current of over 4% by I–V measurement, with a significant increase in the contribution of short‐wavelength light resulting in 25% of the current available in this part of the spectrum being captured. The films have been shown to be highly scattering and the associated difficulties this provides to external quantum efficiency measurements have been discussed. A range of optical characterisation techniques, particularly laser beam induced current, have been used to probe the effect the films have on a cadmium sulfide/cadmium telluride device. An alternate methodology for performing external quantum efficiency measurements with the quantum dot films has been proposed. Copyright © 2013 John Wiley & Sons, Ltd.
A model for the simulation of energy gains when using distributed maximum power point tracking (DMPPT) in photovoltaic arrays
Authors: Solórzano‐Moral Jorge , Masa‐Bote Daniel , Egido‐Aguilera Miguel Angel. , Caamaño‐Martín Estefania 
Published: August 2013

AbstractOver the past years, the photovoltaic (PV) market has been invaded with numerous power optimizers and micro‐inverters that claim large energy gains when used in PV generators with shading or module mismatch. These products provide distributed maximum power point tracking (DMPPT), normally at module level, allowing the maximum power to be extracted from each PV module. This topology can be beneficial in situations where the PV generator is shaded or when there is large module mismatch. However, it is not clear that this power gain will result in energy improvements over a whole year or the lifetime of the system. This paper presents a very detailed and precise model for simulating energy gains with DMPPT as well as its verification and simulation results with different shading profiles, showing the possible energy gain over a whole year. Simulation results show that the yearly energy gain is much lower than the maximum power gain. However, interesting yearly gains of up to 12% are obtained in one of the simulations. Copyright © 2013 John Wiley & Sons, Ltd.
Origin and transport properties of two‐dimensional electron gas at ZnMgO/ZnO interface grown by MOVPE
Authors: Ye Jiandong , Lim Sze Ter , Gu Shulin , Tan H. Hoe , Jagadish Chennupati , Teo Kie Leong 
Published: August 2013

AbstractIn this study, the origin and transport properties of high mobility carriers of two‐dimensional electron gas (2DEG) at ZnMgO/ZnO interface have been investigated. It is found that the observed experimental dependence of carrier sheet density of 2DEG on ZnMgO thickness and Mg composition exhibits an excellent agreement with the theoretical calculations based on the surface charge model. It indicates that the mobile electrons in 2DEG are originated from the donor‐like surface states. Moreover, the anomalous periodicity of Shubnikov‐de Haas oscillations has been observed and the partial spin polarization feature of 2DEG has also been demonstrated, which exhibits the promising development in oxide spintronics applications. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth of ZnO and ZnMgO nanowires by Au‐catalysed molecular‐beam epitaxy
Authors: Isakov Ivan , Panfilova Marina , Sourribes Marion J. L. , Warburton Paul A. 
Published: August 2013

AbstractWe have studied oxygen‐plasma assisted molecular‐beam epitaxy growth of ZnMgO nanostructures catalysed by gold. The growth was carried out at temperatures ranging from 350 to 900 °C. Au droplets were prepared by annealing a thermally evaporated Au thin film, or by deposition of Au colloidal particles, or by electron‐beam lithography with a subsequent Au lift‐off deposition process. The resulting nanowires grow at temperatures in the range 700–850 °C with diameter 40–100 nm and with length up to 4 μm. In order to increase nanowire density and reduce tapering, two‐step growth with a ZnO low‐temperature buffer‐layer was successfully implemented. To study Mg incorporation into ZnO nanowires, Zn1–xMgxO nanowires were grown with normalized Mg flux up to 11%. High resolution microscopy, energy‐dispersive X‐ray spectroscopy and X‐ray diffraction reveal that Mg‐doped nanowires grow in single phase with Mg content up to 7.5%. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Bestimmung der Dickenzuschläge für wetterfesten Stahl im Brückenbau
Authors: Krřivý Vít , Marek Pavel , Kreislová Kateřina , Knotková Dagmar 
Published: August 2013

AbstractDie Korrosionsgeschwindigkeiten von wetterfestem Stahl sind im Vergleich mit herkömmlichem Kohlenstoffstahl erheblich niedriger. Trotzdem muss beim Konstruktionsentwurf ein möglicher Einfluss von Korrosion auf die zuverlässig funktionierende Konstruktion für den gesamten Zeitraum ihrer geplanten Nutzungsdauer berücksichtigt werden. Bei der praktischen Gestaltung wird der Einfluss der angenommenen Korrosionsverluste für gewöhnlich über Dickenzuschläge eliminiert, welche zur Dicke der Elemente, die durch statische Berechnung ermittelt wurde, addiert werden. Im vorliegenden Artikel wird eine neue Methode zur Berechnung der Dickenzuschläge angeführt, die bei Entwürfen für Brückenkonstruktionen aus wetterfestem Stahl genutzt werden kann. Dies wird an Hand eines Modellbeispiels erklärt.Design of corrosion allowances on weathering steel bridges. The corrosion rate of the weathering steel is considerably lower than that of the standard carbon steel. Nevertheless possible effects of corrosion losses on reliable service of the structure throughout the designed service life should be considered when designing the structures. In practice, the effects of the expected corrosion losses are typically eliminated by corrosion allowances which are added to the thickness of the element calculated in static analyses. This paper introduces a new method used for calculation of corrosion allowances on weathering steel bridges. This will be explained using an example of a bridge structure.
Einzelfeldbeulen – Wirklich große Unterschiede zwischen Eurocode EN 1993‐1‐5 und DIN 18800‐3?
Authors: Unterweger Harald , Kettler Markus 
Published: August 2013

AbstractFür einzelne Beispiele von Einzelfeldern liefert der Beulnachweis nach Eurocode EN 1993‐1‐5 deutliche Abweichungen im Ergebnis gegenüber der Berechnung nach DIN 18800‐3. Diese unerwartet großen Unterschiede bei der Berechnung nach der bisher üblichen Methode – nunmehr in EN 1993‐1‐5 als Methode der reduzierten Spannungen bezeichnet – führten zu einer umfassenden Parameterstudie seitens der Autoren dieses Beitrages. Für unterschiedliche Beulfeldgeometrien, Blechschlankheiten und Beanspruchungskombinationen (σx, σx τ, σx σz) werden die quantitativen Unterschiede beider Normenwerke dargestellt und mit einer realitätsnahen nichtlinearen FEM‐Berechnung verglichen. Ergänzend wird auf die Vorgehensweise beim Beulnachweis nach EN 1993‐1‐5 im Vergleich zu DIN 18800‐3 detailliert eingegangen sowie auf die Vorgehensweise bei den realitätsnahen FEM‐Berechnungen.Unstiffened panels – Really big differences between Eurocode EN 1993‐1‐5 and DIN 18800‐3? For individual examples of single panels the plate buckling verification based on EN 1993‐1‐5 gives significant differences compared to DIN 18800‐3. These unexpected differences – based on the traditional concept of the reduced stress method – lead to a comprehensive parameter study by the authors. For different geometries of panels, plate slenderness and combination of stresses (σx, σx τ, σx σz) the different results of both codes are presented and compared to a realistic nonlinear FEM‐analyses. In addition the procedure for plate buckling verification based on EN 1993‐1‐5 is presented in detail and compared to DIN 18800‐3, as well as to nonlinear FEM‐analyses.
Noninvasive pulsed focused ultrasound allows spatiotemporal control of targeted homing for multiple stem cell types in murine skeletal muscle and the magnitude of cell homing can be increased through repeated applications
Authors: Burks Scott R. , Ziadloo Ali , Kim Saejeong J. , Nguyen Ben A. , Frank Joseph A. 
Published: August 2013

Abstract
Stem cells are promising therapeutics for cardiovascular diseases, and i.v. injection is the most desirable route of administration clinically. Subsequent homing of exogenous stem cells to pathological loci is frequently required for therapeutic efficacy and is mediated by chemoattractants (cell adhesion molecules, cytokines, and growth factors). Homing processes are inefficient and depend on short-lived pathological inflammation that limits the window of opportunity for cell injections. Noninvasive pulsed focused ultrasound (pFUS), which emphasizes mechanical ultrasound–tissue interactions, can be precisely targeted in the body and is a promising approach to target and maximize stem cell delivery by stimulating chemoattractant expression in pFUS-treated tissue prior to cell infusions. We demonstrate that pFUS is nondestructive to murine skeletal muscle tissue (no necrosis, hemorrhage, or muscle stem cell activation) and initiates a largely M2-type macrophage response. We also demonstrate that local upregulation of chemoattractants in pFUS-treated skeletal muscle leads to enhance homing, permeability, and retention of human mesenchymal stem cells (MSC) and human endothelial precursor cells (EPC). Furthermore, the magnitude of MSC or EPC homing was increased when pFUS treatments and cell infusions were repeated daily. This study demonstrates that pFUS defines transient “molecular zip codes” of elevated chemoattractants in targeted muscle tissue, which effectively provides spatiotemporal control and tunability of the homing process for multiple stem cell types. pFUS is a clinically translatable modality that may ultimately improve homing efficiency and flexibility of cell therapies for cardiovascular diseases.
Dynamic compaction of human mesenchymal stem/precursor cells into spheres self-activates caspase-dependent IL1 signaling to enhance secretion of modulators of inflammation and immunity (PGE2, TSG6, and STC1)
Authors: Bartosh Thomas J. , Ylöstalo Joni H. , Bazhanov Nikolay , Kuhlman Jessica , Prockop Darwin J. 
Published: August 2013

Abstract
Human mesenchymal stem/precursor cells (MSC) are similar to some other stem/progenitor cells in that they compact into spheres when cultured in hanging drops or on nonadherent surfaces. Assembly of MSC into spheres alters many of their properties, including enhanced secretion of factors that mediate inflammatory and immune responses. Here we demonstrated that MSC spontaneously aggregated into sphere-like structures after injection into a subcutaneous air pouch or the peritoneum of mice. The structures were similar to MSC spheres formed in cultures demonstrated by the increased expression of genes for inflammation-modulating factors TSG6, STC1, and COX2, a key enzyme in production of PGE2. To identify the signaling pathways involved, hanging drop cultures were used to follow the time-dependent changes in the cells as they compacted into spheres. Among the genes upregulated were genes for the stress-activated signaling pathway for IL1α/β, and the contact-dependent signaling pathway for Notch. An inhibitor of caspases reduced the upregulation of IL1A/B expression, and inhibitors of IL1 signaling decreased production of PGE2, TSG6, and STC1. Also, inhibition of IL1A/B expression and secretion of PGE2 negated the anti-inflammatory effects of MSC spheres on stimulated macrophages. Experiments with γ-secretase inhibitors suggested that Notch signaling was also required for production of PGE2 but not TSG6 or STC1. The results indicated that assembly of MSC into spheres triggers caspase-dependent IL1 signaling and the secretion of modulators of inflammation and immunity. Similar aggregation in vivo may account for some of the effects observed with administration of the cells in animal models.
Early outgrowth cells release soluble endocrine antifibrotic factors that reduce progressive organ fibrosis
Authors: Yuen Darren A. , Connelly Kim A. , Zhang Yanling , Advani Suzanne L. , Thai Kerri , Kabir Golam , Kepecs David , Spring Christopher , Smith Christopher , Batruch Ihor , Kosanam Hari , Advani Andrew , Diamandis Eleftherios , Marsden Philip A. , Gilbert Richard E. 
Published: August 2013

Abstract
Adult bone marrow-derived cells can improve organ function in chronic disease models, ostensibly by the release of paracrine factors. It has, however, been difficult to reconcile this prevailing paradigm with the lack of cell retention within injured organs and their rapid migration to the reticuloendothelial system. Here, we provide evidence that the salutary antifibrotic effects of bone marrow-derived early outgrowth cells (EOCs) are more consistent with an endocrine mode of action, demonstrating not only the presence of antifibrotic factors in the plasma of EOC-treated rats but also that EOC conditioned medium (EOC-CM) potently attenuates both TGF-β- and angiotensin II-induced fibroblast collagen production in vitro. To examine the therapeutic relevance of these findings in vivo, 5/6 subtotally nephrectomized rats, a model of chronic kidney and heart failure characterized by progressive fibrosis of both organs, were randomized to receive i.v. injections of EOC-CM, unconditioned medium, or 106 EOCs. Rats that received unconditioned medium developed severe kidney injury with cardiac diastolic dysfunction. In comparison, EOC-CM-treated rats demonstrated substantially improved renal and cardiac function and structure, mimicking the changes found in EOC-treated animals. Mass spectrometric analysis of EOC-CM identified proteins that regulate cellular functions implicated in fibrosis. These results indicate that EOCs secrete soluble factor(s) with highly potent antifibrotic activity, that when injected intravenously replicate the salutary effects of the cells themselves. Together, these findings suggest that an endocrine mode of action may underlie the effectiveness of cell therapy in certain settings and portend the possibility for systemic delivery of cell-free therapy.
Possible regulation of connexin function through gene duplication events
Authors: Iovine M. Kathryn 
Published: August 2013

Gap junctions are proteinaceous channels that allow direct cell–cell communication via the exchange of small molecules and ions among neighboring cells. The subunits of gap junction channels found in chordates are termed connexins. Remarkably, a large number of connexin genes have been identified in all vertebrate species examined to date. It is not fully understood why so many connexin genes are required for what appears to be a simple function. Phylogenetic analyses have revealed connexin losses and gains during evolution. Presently, it is of interest to clarify why so many connexin genes are retained within genomes. One possibility is that additional connexins provide novel coupling properties for gap junction channels. Alternatively, connexin genes may be capable of establishing novel functions in order to regulate their paralogous connexin, which retains a more typical gap junction activity. Two examples of the latter have been identified. Both mouse Cx33 and zebrafish Cx40.8 can be found intracellularly, and both are implicated in the regulation of Cx43‐based gap junctional communication. Continuing studies will provide mechanistic details into how these non‐gap junction channel connexins regulate the function of gap junction channels. WIREs Membr Transp Signal 2013, 2:221–225. doi: 10.1002/wmts.92Conflict of interest: The author has declared no conflicts of interest for this article.For further resources related to this article, please visit the WIREs website.
WIF1 causes dysfunction of heart in transgenic mice
Authors: Lu Dan , Dong Wei , Zhang Xu , Quan Xiongzhi , Bao Dan , Lu Yingdong , Zhang Lianfeng 
Published: August 2013

AbstractWnt activity is a key regulator of cardiac progenitor cell self-renewal, differentiation and morphogenesis. However, Wnt inhibitory factor 1 (WIF1), a antagonists of Wnt signaling activity, its potential effects on heart development has not yet been approached by either in vivo or in vitro studies. Here, the expression of WIF1 was regulated in a different way in the dilated and hypertrophic cardiomyopathy heart from transgenic mice by mutations in cardiac troponin T, cTnTR141W and cTnTR92Q. The heart tissue specific transgenic mice of WIF1 was studied using M-mode echocardiography and histologic analyses. Production levels of an array of effectors and transcription factors that impact cellular organization and tissue morphology were measured. The effects of WIF1 on β-catenin pathway could be reversed by LiCl regarding signaling pathways and effector and respondent molecules in H9c2 cells, consistent with the expression levels of c-myc, natriuretic peptide precursor type B and skeletal muscle actin α1. Among the most noteworthy findings were that WIF1 impaired the function and structure of heart, and the effects on β-catenin pathway maybe the course of the former. It is anticipated that our findings will contribute to expansion of our understanding of WIF1 biological function on heart development and possible modes of treatment of heart diseases.
Effect of COMT Val158Met polymorphism on personality traits and educational attainment in a longitudinal population representative study
Authors: Lehto K. , Akkermann K. , Parik J. , Veidebaum T. , Harro J. 
Published: August 2013

AbstractThe COMT Val158Met polymorphism has been associated with anxiety and affective disorders, but its effect on anxiety-related personality traits varies between studies. Our purpose was to investigate the effect of COMT Val158Met on personality traits from adolescence to young adulthood in a population representative Caucasian birth cohort. Also its association with educational attainment and anxiety and mood disorders by the age 25 were examined. This analysis is based on the older cohort of the Estonian Children Personality Behavior and Health Study (original number of subjects 593). The personality traits were assessed when the participants were 15, 18 and 25 years old. COMT Val158Met had an effect on Neuroticism in females by age 25 (p = 0.001, Bonferroni-corrected for five traits), whereas female Val homozygotes scored the highest. In addition, the Conscientiousness scores of subjects with Val/Val genotype were decreasing in time, being the lowest by the age 25 (p = 0.006, Bonferroni-corrected for five traits). By the age 25, males with the Val/Met genotype had mainly secondary or vocational education, whereas female heterozygotes mostly had obtained or were obtaining university education. COMT Val158Met was not associated with anxiety or mood disorders in either gender. These results suggest that genes affecting dopamine system are involved in the development of personality traits and contribute to educational attainment.
Stiffener Insertion Based Variance in Radial Stiffness of Multi-Concentric Hollow Tubes
Authors: Sato Motohiro , Shima Hiroyuki , Park S.-J. 
Published: August 2013

ABSTRACTShell theory solutions for radial buckling of multiply-concentric hollow cylinders are presented. Multi-cylindrical systems are those composed of two or more concentically mounted hollow tubes, wherein the annular space mediates inter-tube forces, attractive or repulsive depending on structural details of composites. Reflecting the multiple core-shell structures, the systems often exhibit peculiar radial buckling modes, which should be relevant to macro scale applications for deep water oil and gas transportation andmicroscale realization in lipid bilayer tubes. In this article, we focus on an illustrative example of such the multiply-tubular systems with nanometric dimension, the so-called multiwalled carbon nanotubes (MWNTs). Theoretical analysis based on a thin shell theory allows us to find anomalous radial buckling behaviors of MWNTs driven by hydrostatic pressure. The obtained buckling modes are characterized by petal-like wavy cross sections, which is what we call the radial corrugation of MWNTs. An important observation is the mechanical consequence of stiff core-tube insertion into the innermost hollow region of a given MWNT. The insertion results in a significant variance in the critical buckling pressure, above which the MWNT undergoes radial corrugation. The insertion-induced-variance in the critical pressure is due to the primary role of inter-tube interaction between adjacent constituent tubes, as explained within our theoretical model.
TEATIME: BOREDOM AND THE TEMPORALITIES OF YOUNG MEN IN NIGER
Authors: Masquelier Adeline 
Published: August 2013

ABSTRACTTo fight boredom, un(der)employed young men in Niger have joined fadas (youth clubs) where they listen to music, play card games and strike up new friendships – or nurture old ones. Membership in these organizations cuts across social divides, educational backgrounds and religious affiliations, affirming the spirit of egalitarianism and comradeship that drives these largely urban projects. At the fada, conversation routinely takes place around the making and sharing of tea, a ritual idle young men have come to value greatly as they struggle to fill their days with purpose and direction. Whereas elders largely condemn fadas as futile, self-indulgent, and occasionally criminal endeavours, samari (young men) defend their pastimes, claiming that they engage in meaningful activities. In this essay I explore the temporalities of teatime at the fada. Rather than focus on what is lost under conditions of crisis and privation, I consider instead what is produced, and in particular how value, exchange, and affect emerge in the context of daily routines at the fada. In the absence of other temporal markers punctuating daily life, the practice of preparing and consuming tea becomes a key happening, enabling samari to carve out meaningful temporalities and reconfigure their relation to the future.