bluuebunny/crossref_metadata_2025_split huggingface dataset:
Trap States in TiO2 Films Made of Nanowires, Nanotubes or Nanoparticles: An Electrochemical Study
Authors: Jankulovska Milena , Berger Thomas , Wong Stanislaus S. , Gómez Roberto , Lana‐Villarreal Teresa 
Published: June 2012

AbstractThe presence of electronic traps in nanoporous TiO2 electrodes has been studied by cyclic voltammetry in aqueous media. These simple measurements allow us to map the density of states, providing evidence for the presence of a relatively small number of discrete electron traps at the band gap. We have taken advantage of the variety of TiO2 synthetic procedures that lead to well‐defined morphologies (such as nanowires, nanocolumns, nanotubes, and nanoparticles) of anatase and rutile to investigate the nature of these electron traps. They derive from the structural disorder at the contact between neighboring crystalline nanoparticles. As expected, both their density and energetic location are highly dependent, not only on the crystalline structure (whether it is anatase or rutile), but also on the electrode morphology (i.e. the facets that meet at the grain boundaries). The trap density is also sensitive to pH changes and to the presence of some adsorbates. This variation of the number of traps with the electrolyte indicates that on one hand, an apparent electronic density of states is actually measured. On the other, it indicates that the traps are surface‐related in agreement with their particular location at the perimeter of the grain boundaries. The effect of these traps on the observed electrode catalytic reactivity has also been studied. In the dark, it is found that they are directly involved in the electron transfer toward oxygen. In addition, under illumination, the trap states show a deleterious effect, favoring electron recombination.
0.5‐V bulk‐driven differential amplifier
Authors: Raikos George , Vlassis Spyridon 
Published: June 2012

SUMMARYA new 0.5‐V fully differential amplifier is proposed in this article. The structure incorporates a differential bulk‐driven voltage follower with conventional gate‐driven amplification stages. The bulk‐driven voltage follower presents differential gain equal to unity while suppressing the input common‐mode voltage. The amplifier operates at a supply voltage of less than 0.5 V, performing input transconductance almost equal to a gate transconductance and relatively high voltage gain without the need for gain boosting. The circuit was designed and simulated using a standard 0.18‐µm CMOSn‐well process. The low‐frequency gain of the amplifier was 56 dB, the unity gain bandwidth was approximately 3.2 MHz, the spot noise was 100 nV/√Hz at 100 kHz and the current consumption was 90 μΑ. Copyright © 2012 John Wiley & Sons, Ltd.
Simulation Study of an Extended Divertor Leg for Heat Control in the SlimCS DEMO Reactor
Authors: Hoshino K. , Shimizu K. , Asakura N. , Takizuka T. , Nakamura M. , Tobita K. 
Published: June 2012

AbstractPower handling in the divertor is one of the most important issues for fusion tokamak reactor design. In this study, the effect of the divertor leg length on power handling in the SlimCS DEMO reactor is investigated for future divertor design. Simulation with the SONIC code suite shows enhancement of recycling in the outer divertor region due to effects of the long divertor leg and the deep V‐shaped corner. As a result, the ion and electron temperature at the outer divertor significantly decreases. In addition, the peak of the Ar impurity radiation, which is located close to the outer divertor target in the standard divertor geometry, moves upstream. The former effect decreases the heat load to the outer divertor due to ion conduction and convection, while the latter reduces the heat load due to the impurity radiation. The peak of the total heat load on the outer divertor decreases by about 30 % (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A complex speciation–richness relationship in a simple neutral model
Authors: Desjardins‐Proulx Philippe , Gravel Dominique 
Published: June 2012

AbstractSpeciation is the “elephant in the room” of community ecology. As the ultimate source of biodiversity, its integration in ecology's theoretical corpus is necessary to understand community assembly. Yet, speciation is often completely ignored or stripped of its spatial dimension. Recent approaches based on network theory have allowed ecologists to effectively model complex landscapes. In this study, we use this framework to model allopatric and parapatric speciation in networks of communities. We focus on the relationship between speciation, richness, and the spatial structure of communities. We find a strong opposition between speciation and local richness, with speciation being more common in isolated communities and local richness being higher in more connected communities. Unlike previous models, we also find a transition to a positive relationship between speciation and local richness when dispersal is low and the number of communities is small. We use several measures of centrality to characterize the effect of network structure on diversity. The degree, the simplest measure of centrality, is the best predictor of local richness and speciation, although it loses some of its predictive power as connectivity grows. Our framework shows how a simple neutral model can be combined with network theory to reveal complex relationships between speciation, richness, and the spatial organization of populations.
Flywheel size design considerations and experimental verification using a 50‐kW system for voltage sag compensator with flywheel induction motor
Authors: Kato Shuhei , Cheng Miao‐Miao , Sumitani Hideo , Shimada Ryuichi 
Published: June 2012

AbstractFlywheel energy storage systems can be used as an uninterrupted power supply system because they are environmentally friendly and have high durability. The use of a simple voltage sag compensator with a low‐speed heavy flywheel and a low‐cost squirrel‐cage induction motor/generator is proposed. First, the ability of the proposed system to maintain the load voltage at 100% when the grid is experiencing voltage sag is validated experimentally. Next, design guidelines for the flywheel stored energy are discussed. Experimental verification of a 50‐kW‐class system is carried out, and the results show good agreement with the developed design guidelines. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 181(1): 36–44, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.21252
A Porous Metal‐Organic Framework Based on Triazoledicarboxylate Ligands – Synthesis, Structure, and Gas‐Sorption Studies
Authors: Wen Liang , Shi Wei , Chen Xitong , Li Huanhuan , Cheng Peng 
Published: June 2012

AbstractA new porous metal‐organic framework (MOF) {[CuL]·DMF·2H2O}n [1a, H2L = 5‐(4H‐1,2,4‐triazol‐4‐yl)benzene‐1,3‐dicarboxylic acid; DMF = N,N‐dimethylformamide] with zigzag‐shaped, narrow channels was prepared by solvothermal synthesis and structurally characterized. 1a has zigzag‐shaped, open channels with micropore sizes of approximately 5.6 × 4.6 Å2. The (3,6)‐connected network of 1a leads to an α‐PbO2 (apo) topology. The adsorption properties (N2, H2, and CO2) of the desolvated sample 1c have been studied. The results show that 1c has a highly porous structure and a high adsorption capacity: the total capture of CO2 at 1 bar and 298 K is 22.01 wt.‐%, and the total H2 uptake at 1 bar and 77 K is 1.46 wt.‐%. This high adsorption capacity can be attributed to strong interactions between the small gas molecules and the irregularly open channels with their zigzag shape and their narrow pore size.
Kinetically Stable LnIII Complexes Comprising a Trinuclear Core Sandwiched between Two Thiacalix[4]arene Ligands Self‐Assembled in Water (LnIII = NdIII, YbIII)
Authors: Iki Nobuhiko , Hiro‐oka Shouichi , Nakamura Mami , Tanaka Teppei , Hoshino Hitoshi 
Published: June 2012

AbstractIn aqueous solutions, thiacalixarene (TCAS) and LnIII (= NdIII, YbIII) self‐assembled over a long period of time (1 d) to form 3:2 complexes LnIII3·TCAS2 in which the LnIII3 core is sandwiched between two TCAS ligands, which results in a high kinetic stability. This was not expected from the exo‐coordination fashion of TCAS with the O,S,O donors found in the 1:1 complex LnIII·TCAS, and thus this feature was attributed to the multiple bonds between the LnIII3 core and TCAS. Our observations open an exciting possibility of designing kinetically stable LnIII complexes by using exo‐type ligands as scaffolds to sandwich a multi‐LnIII core rather than endo‐type ones to encapsulate a LnIII core.
Molecularly Imprinted Electrochemical Luminescence Sensor Based on Enzymatic Amplification for Ultratrace Isoproturon Determination
Authors: Li Shuhuai , Tao Huilin , Li Jianping 
Published: June 2012

AbstractA new molecularly imprinted electrochemical luminescence sensor (MIP‐ECL sensor) was developed for isoproturon (IPU) determination based on the competition reaction between IPU and glucose oxidase labeled IPU (GOD‐IPU). After competition, hydrogen peroxide produced by residual GOD‐IPU on the MIP reacted with luminol to emit electrochemiluminescence (ECL) signal. The ECL intensity decreased when the GOD‐IPU molecules were replaced by IPU molecules in the samples. IPU could be determined in the concentration range from 9×10−11 mol/L to 5.1×10−9 mol/L with a detection limit of 3.78×10−12 mol/L. Water samples were assayed and recoveries ranging from 98.5 % to 102.1 % were obtained.
Anodic Behaviour of Flavonoids Orientin, Eriodictyol and Robinin at a Glassy Carbon Electrode
Authors: de Souza Gil Eric , Enache Adrian Teodor , de Oliveira‐Brett Ana Maria 
Published: June 2012

AbstractOrientin, eriodictyol and robinin are polyphenolic compounds, and their oxidation mechanism is pH‐dependent, in two steps, involving a different number of electrons and protons. Orientin and eriodictyol first oxidation occurs at a lower potential, corresponding to the reversible oxidation of the catechol group, and is followed by an irreversible oxidation on the ring‐A at more positive potential. Robenin oxidation is irreversible, with the formation of electroactive products, and occurs at ring‐A and ring‐B. The electrochemical characterization of their redox behaviour brought useful data about their chemical stability, antioxidant and pro‐oxidant activity, enabling a comprehensive understanding of their redox mechanism.
Phenotyping primary human microglia: Tight regulation of LPS responsiveness
Authors: Melief Jeroen , Koning Nathalie , Schuurman Karianne G. , Van De Garde Martijn D. B. , Smolders Joost , Hoek Robert M. , Van Eijk Marco , Hamann Jörg , Huitinga Inge 
Published: June 2012

AbstractMuch is still unknown about mechanisms underlying the phenotypical and functional versatility of human microglia. Therefore, we developed a rapid procedure to isolate pure microglia from postmortem human brain tissue and studied their immediate ex vivo phenotype and responses to key inflammatory mediators. Microglia were isolated, along with macrophages from the choroid plexus by tissue dissociation, density gradient separation, and selection with magnetic microbeads. By flow cytometry, microglia were identified by a CD11b+CD45dim phenotype and a smaller size compared with CD11b+CD45high macrophages. Interestingly, white matter microglia from donors with peripheral inflammation displayed elevated CD45 levels and increased size and granularity, but were still distinct from macrophages. The phenotype of isolated microglia was further specified by absent surface expression of CD14, CD200 receptor, and mannose receptor (MR, CD206), all of which were markedly expressed by macrophages. Microglia stimulated immediately after isolation with LPS and IFNγ failed to upregulate TNFα or CCR7. Notably, responsiveness to LPS and IFNγ was clearly instigated in microglia after overnight preculture, which coincided with a strong upregulation of CD14. Culture of microglia with IL‐4 resulted in the induction of HLA‐DR and CCL18 but not MR, whereas culture with dexamethasone did induce MR, in addition to CD163 and CCL18. In conclusion, this study demonstrates phenotypic changes of microglia associated with peripheral inflammation, and reveals tight regulation of responses to LPS and IFNγ as well as distinct microglial responses to IL‐4 and glucocorticoids. These findings are of high relevance to studies on human microglia functioning in health and disease. © 2012 Wiley Periodicals, Inc.
Microglia as modulators of cognition and neuropsychiatric disorders
Authors: Blank Thomas , Prinz Marco 
Published: June 2012

AbstractIt has become evident recently only that microglia are not only responsible for immunomodulatory functions in the brain but represent vital components of the larger synaptic formation, which also includes pre and postsynaptic neurones as well as astrocytes. Microglia critically contribute to CNS homeostasis by their actions in phagocytosis of cellular debris, release of a variety of cell signaling factors including neurotrophins and extracellular matrix components and direct contact with neurons. The purpose of this review is to summarize our current understanding of the involvement of microglia in cognitive processes and neuropsychiatric disorders including schizophrenia, bipolar disorder, depression, and Rett syndrome and to outline their potential signaling mechanisms in this context. © 2012Wiley Periodicals, Inc.
Using Chernobyl‐derived 137Cs to document recent sediment deposition rates on the River Plava floodplain (Central European Russia)
Authors: Belyaev V. R. , Golosov V. N. , Markelov M. V. , Evrard O. , Ivanova N. N. , Paramonova T. A. , Shamshurina E. N. 
Published: June 2012

AbstractFloodplain sedimentation is one of the most dynamic geomorphic processes within plain and lowland landscapes. There is generally a good understanding of longer term floodplain evolution, but quantitative information on overbank deposition rates for recent shorter timescales is lacking. This paper describes the application of Chernobyl‐derived 137Cs to quantify floodplain aggradation rates for the River Plava (a small river draining a severely contaminated part of the upland region of Central European Russia), based on detailed sampling of four representative floodplain study sites. Two approaches have been employed for estimating post‐Chernobyl (1986–2009) floodplain accumulation rates. The first was based simply on locating the Chernobyl fallout‐associated 137Cs peak in overbank sediment sections. The second involved quantification of the increase in the total 137Cs inventory at individual sampling points associated with the post‐Chernobyl deposition of contaminated suspended sediment. It has been shown that considerable local‐scale variability of overbank deposition rates exists, with aggradation rates on the low level floodplain (6 ± 1.2–14 ± 2.8 mm year−1) exceeding by 1.5–3 times the values for the middle level floodplain (2 ± 0.4–9 ± 1.8 mm year−1) and by 3–6 times the values for the upper level floodplain (1 ± 0.2–5 ± 1.0 mm year−1) floodplain levels. Combining these estimates with information on the areas occupied by different floodplain levels within the 54 km long valley section, derived from detailed geomorphic surveys of the selected reaches, it has been estimated that about 9700 ± 1950 t of sediment have been stored on floodplain during the 1986–2009 period. The role of floodplain storage in the overall basin sediment budget and conveyance losses within the main channel system have been evaluated. Copyright © 2012 John Wiley & Sons, Ltd.
Noggin suppression decreases BMP‐2‐induced osteogenesis of human bone marrow‐derived mesenchymal stem cells In Vitro
Authors: Chen Chao , Uludağ Hasan , Wang Zhixiang , Jiang Hongxing 
Published: June 2012

AbstractNumerous studies with rodent cells and animal models indicate that noggin inhibits osteogenesis by antagonizing bone morphogenetic proteins (BMPs); however, the effect of noggin on osteogenesis of human cells remains ambiguous. This study aims to examine the effects of noggin suppression on viability and BMP‐2‐induced osteogenic differentiation of human bone marrow‐derived mesenchymal stem cells (MSCs) in vitro. Noggin expression in human MSCs was suppressed by noggin‐specific small interfering RNA (siRNA), and viability of human MSCs was determined by measuring the mitochondrial dehydrogenase activity, cellular DNA content and protein amount. The BMP‐2‐induced osteogenic differentiation of human MSCs was assessed by analyzing the expression levels of several osteoblastic genes, enzymatic alkaline phosphatase (ALP) activity and calcification. Our study showed that noggin suppression significantly decreased human MSC metabolism and DNA content on Days 3 and 6, and decreased total protein amount on Day 14. Noggin suppression also reduced the expression levels of osteoblastic genes, ALP, integrin‐binding sialoprotein (IBSP), muscle segment homeobox gene (MSX2), osteocalcin (OC), osteopontin (OPN), and runt‐related transcription factor‐2 (RUNX2). Significantly decreased enzymatic ALP activity in noggin‐suppressed group was evident. Moreover, noggin suppression decreased calcium deposits by BMP‐2‐induced osteoblasts. Collectively, this study showed that noggin suppression decreased viability and BMP‐2‐induced osteogenic differentiation of human MSCs, which suggests that noggin is stimulatory to osteogenesis of human MSCs. J. Cell. Biochem. 113: 3672–3680, 2012. © 2012 Wiley Periodicals, Inc.
The vitamin D analog ZK191784 normalizes decreased bone matrix mineralization in mice lacking the calcium channel TRPV5
Authors: van der Eerden Bram C.J. , Fratzl‐Zelman Nadja , Nijenhuis Tom , Roschger Paul , Zügel Ulrich , Steinmeyer Andreas , Hoenderop Joost G.J. , Bindels René J.M. , Klaushofer Klaus , van Leeuwen Johannes P.T.M. 
Published: June 2012

AbstractMice lacking the renal epithelial Ca2+ channel TRPV5 (TRPV5−/−) display impaired renal Ca2+ reabsorption, hypercalciuria, and intestinal Ca2+ hyperabsorption, due to secondary hypervitaminosis D. Using these mice, we previously demonstrated that ZK191784 acts as an intestine‐specific 1,25(OH)2D3 antagonist without affecting serum calcium levels. On the other hand, it acted as an agonist in the kidney and the effects of ZK191784 on bone were ambiguous. The present study was undertaken to further evaluate the effect of the vitamin D receptor antagonist on murine bone in mice lacking TRPV5. Eight‐week‐old female Trpv5+/+ and Trpv5−/− mice were treated for 4 weeks with or without 50 µg/kg/day ZK191784. Quantitative backscattered electron imaging showed that the reduced bone matrix mineralization found in femoral bones of Trpv5−/− mice was partially but significantly restored upon ZK191784 treatment, just as we observed for trabecular bone thickness. This supports the significance of 1,25(OH)2D3 and optimal control of Ca2+ homeostasis for bone formation and matrix mineralization. Restoration also took place at the bone gene expression level, where 1α‐hydroxylase (Cyp27b1) mRNA in femurs from ZK‐treated Trpv5−/− mice was upregulated compared to control levels. The downregulated 24‐hydroxylase (Cyp24a1) gene expression in femoral bone indicated local vitamin D resistance in the mice treated with ZK191784. Phosphate homeostasis was unaffected between the groups as shown by unaltered serum $PO_{4}^{3- } $ and fibroblast growth factor (FGF) 23 as well as Fgf23 mRNA expression in bone. In conclusion, circulating 1,25(OH)2D3 is important for optimal control of Ca2+ homeostasis but also for controlled bone formation and matrix mineralization. J. Cell. Physiol. 228: 402–407, 2013. © 2012 Wiley Periodicals, Inc.
Inclined selective plane illumination microscopy adaptor for conventional microscopes
Authors: Cutrale Francesco , Gratton Enrico 
Published: June 2012

AbstractDriven by the biological sciences, there is an increased need for imaging modalities capable of live cell imaging with high spatial and temporal resolution. To achieve this goal in a comprehensive manner, three‐dimensional acquisitions are necessary. Ideal features of a modern microscope system should include high imaging speed, high contrast ratio, low photo‐bleaching and photo‐toxicity, good resolution in a 3D context, and mosaic acquisition for large samples. Given the importance of collecting data in live sample further increases the technical challenges required to solve these issues. This work presents a practical version of a microscopy method, Selective Plane Illumination Microscopy re‐introduced by Huisken et al. (Science2004,305,1007–1009). This method is gaining importance in the biomedical field, but its use is limited by difficulties associated with unconventional microscope design which employs two objectives and a particular kind of sample preparation needed to insert the sample between the objectives. Based on the selective plane illumination principle but with a design similar to the Total Internal Reflection Fluorescence microscope, Dunsby (Dunsby, Opt Express2008,16,20306–20316) demonstrated the oblique plane microscope (OPM) using a single objective which uses conventional sample preparation protocols. However, the Dunsby instrument was not intended to be part of a commercial microscope. In this work, we describe a system with the advantages of OPM and that can be used as an adaptor to commonly used microscopes, such as IX‐71 Olympus, simplifying the construction of the OPM and increasing performance of a conventional microscope. We named our design inclined selective plane illumination microscope (iSPIM). Microsc. Res. Tech. 2012. © 2012 Wiley Periodicals, Inc.
Minimal Obstructions for 1‐Immersions and Hardness of 1‐Planarity Testing
Authors: Korzhik Vladimir P. , Mohar Bojan 
Published: June 2012

AbstractA graph is 1‐planar if it can be drawn on the plane so that each edge is crossed by no more than one other edge (and any pair of crossing edges cross only once). A non‐1‐planar graph G is minimal if the graph is 1‐planar for every edge e of G. We construct two infinite families of minimal non‐1‐planar graphs and show that for every integer , there are at least nonisomorphic minimal non‐1‐planar graphs of order n. It is also proved that testing 1‐planarity is NP‐complete.
Dika nut oil as base oil for lubricants — effect of processing conditions on physicochemical properties
Authors: Abidakun O. A. , Koya O. A. 
Published: June 2012

ABSTRACTThe paper presents a report on the effect of processing conditions of Dika nut oil on its physicochemical properties and also on the assessment of the oil for use as biodegradable lubricant. The oil was expressed mechanically from coarsely ground kernel meals at 3 and 9 wt.% moisture content (wet basis), preheated at 75, 100 and 150 °C for 10, 20 and 30 min. The plots showed that the chemical properties of the oil had quadratic and linear relationships with the heating temperature and heating time, respectively. At 95% confidence level, the free fatty acid content, the saponification, the iodine and the acid values of the oil were significantly affected by various processing conditions. The processing conditions therefore showed significant influence on the physicochemical properties of the oil and consequently on its suitability for use as lubricant. Copyright © 2012 John Wiley & Sons, Ltd.