bluuebunny/crossref_metadata_2025 huggingface dataset:
Photoinduced reorientation and polarization holography in a new photopolymer with 4-methoxy-N-benzylideneaniline side groups
Authors: Kawatsuki Nobuhiro , Matsushita Hitomi , Kondo Mizuho , Sasaki Tomoyuki , Ono Hiroshi
Published: August 2013

The photoinduced reorientation and surface relief (SR) formation behaviors of a novel photosensitive polymer, which was transparent in visible region, were investigated using linearly polarized-313-nm light and holographic exposure with a 325-nm He-Cd laser. The polymer was comprised of photosensitive 4-methoxy-N-benzylideneaniline side groups, and exhibited a sufficient photoinduced molecular reorientation with a birefringence of 0.11. Holographic exposure generated a SR structure, which had a periodical molecular reorientation that depended on the polarization of the interference beams. The generated SR height was ∼212 nm, and the inscription of a double holographic exposure yielded a two-dimensional SR structure.
Local order of Ge atoms in amorphous GeTe nanoscale ultrathin films
Authors: Yu N. N. , Tong H. , Zhou J. , Elbashir A. A. , Miao X. S.
Published: August 2013

We demonstrate the drastic effect of film thickness on the local order of Ge sites in amorphous GeTe ultrathin films by Surface Enhanced Raman Scattering study. The relative intensity of the two prominent peaks around 125 cm−1 and 160 cm−1 changes greatly as a function of the film thickness from 100 nm to 3 nm. We suggest that this change originates from the variation of the fraction of Ge atoms in tetrahedral- and defective octahedral-like sites. Ab initio Molecular Dynamics simulations show that more Ge atoms in ultrathin films are tetrahedrally coordinated. The result is consistent with the experimental observation of Raman spectroscopy.
Nanolabyrinthine ZrAlN thin films by self-organization of interwoven single-crystal cubic and hexagonal phases
Authors: Ghafoor Naureen , Johnson Lars J. S. , Klenov Dmitri O. , Demeulemeester Jelly , Desjardins Patrick , Petrov Ivan , Hultman Lars , Odén Magnus
Published: August 2013

Self-organization on the nanometer scale is a trend in materials research. Thermodynamic driving forces may, for example, yield chessboard patterns in metal alloys [Y. Ni and A. G. Khachaturyan, Nature Mater. 8, 410–414 (2009)]10.1038/nmat2431 or nitrides [P. H. Mayrhofer, A. Hörling, L. Karlsson, J. Sjölén, T. Larsson, and C. Mitterer, Appl. Phys. Lett. 83, 2049 (2003)]10.1063/1.1608464 during spinodal decomposition. Here, we explore the ZrN-AlN system, which has one of the largest positive enthalpies of mixing among the transition metal aluminum nitrides [D. Holec, R. Rachbauer, L. Chen, L. Wang, D. Luefa, and P. H. Mayrhofer, Surf. Coat. Technol. 206, 1698–1704 (2011)10.1016/j.surfcoat.2011.09.019; B. Alling, A. Karimi, and I. Abrikosov, Surf. Coat. Technol. 203, 883–886 (2008)]10.1016/j.surfcoat.2008.08.027. Surprisingly, a highly regular superhard (36 GPa) two-dimensional nanolabyrinthine structure of two intergrown single crystal phases evolves during magnetron sputter thin film synthesis of Zr0.64Al0.36N/MgO(001). The self-organization is surface driven and the synergistic result of kinetic limitations, where the enthalpy reduction balances both investments in interfacial and elastic energies.
Kinetic Monte Carlo modeling of dark and illuminated current-voltage characteristics of bulk heterojunction solar cells
Authors: Baidya Prabin Man , Bayat Khadijeh , Biesecker Matt , Farrokh Baroughi Mahdi
Published: August 2013

Comprehensive Monte Carlo simulation of dark and illuminated IV characteristics of polymer bulk heterojunction solar cells has long been blocked by lack of incorporation of physical processes involved in formation of dark current and charge injection models at the electrodes. This paper introduces quasi-neutral electron and hole transport layers for decoupling contact properties from hopping charge transport in the bulk of donor/acceptor blend. This approach led to comprehensive independent simulation of dark and illuminated IV characteristics which better agree with experimental results. Recombination at the donor/acceptor interface was proved to be the origin of dark IV and the limiting factor of open circuit voltage.
Investigation of the interfacial adhesion of the transparent conductive oxide films to large-area flexible polymer substrates using laser-induced thermo-mechanical stresses
Authors: Park Jin-Woo , Lee Seung-Ho , Yang Chan-Woo
Published: August 2013

In this study, we investigated the interfacial adhesion strength (σint) of transparent conductive oxide (TCO) coatings on polymer substrates using a nanosecond Nd:YAG pulsed laser. We compared our results with those achieved using conventional testing methods such as bending and fragmentation tests as well as theoretical calculations. In the fragmentation and bending tests, mechanical compressive stress is induced in the film due to mismatches in Poisson's ratio and Young's modulus between the substrate and film. But, the incident laser makes the film under compression due to the mismatch in thermal expansion between the TCO and the polymer substrate. With a pulse incident to the substrate, the TCO rapidly expands by laser-induced instant heating while the transparent polymer does little, which causes the TCO to buckle and delaminate over the critical pulse energy. The critical compressive stress that scales with σint was calculated using simple equations, which agreed well with the results from previous theoretical calculations. Because the films preferentially delaminate at the defects and grain boundaries, this technique also provided useful information regarding the interface microstructures. Moreover, because the laser can scan over large areas, this method is suitable for flexible substrates that are produced by a roll-to-roll process. Nevertheless, the mechanical stress introduced by the bending and fragmentation tests causes the TCO to buckle without interfacial delamination. Hence, the stresses at the buckling disagreed with the results obtained from the laser test and the theoretical calculations.
Emission of monochromatic microwave radiation from a nonequilibrium condensation of excited magnons
Authors: Stucchi Vannucchi Fabio , Rosas Vasconcellos Áurea , Luzzi Roberto
Published: August 2013

The observation of monochromatic emission of radiation from a nonequilibrium Bose-Einstein-like condensate of magnons suggests the possibility of creating a monochromatic microwave generator pumped by incoherent broadband sources. The device would have a tunable emitted frequency as a function of the applied constant magnetic field. We present an analysis of the mechanisms of interaction between the condensate of magnons and the radiation field producing the super-radiant emission of photons. The conditions for the emergence of the super-radiance are described, as well as an analysis of its dependence on the thickness of the sample and the applied static magnetic field intensity.
Exploiting phase separation in monolithic La0.6Ca0.4MnO3 devices
Authors: Granja L. , Hueso L. E. , Levy P. , Mathur N. D.
Published: August 2013

Devices based on mesas were fabricated from thin films of magnetically phase-separated La0.6Ca0.4MnO3. Low-field magnetoresistance arises because the volume fraction of the ferromagnetic metallic phase is large enough for percolation but small enough to permit magnetic decoupling between each mesa and the underlying track. Magnetic domain walls in the antiparallel mesa-track configuration possess a giant resistance-area product of (3–7) × 10−8 Ωm2. This figure represents an 11 order-of-magnitude improvement with respect to the figure for cobalt.
Hf dopants in γ′–Ni3Al alloy
Authors: Ivanovski V. N. , Cekić B. , Umićević A. , Belošević-Čavor J. , Schumacher G. , Koteski V. , Barudzija T.
Published: August 2013

The Time Differential Perturbed Angular (TDPAC) measurements of nuclear quadrupole interactions (NQIs) at 181Ta ion probe in the polycrystalline intermetallic alloy γ′–Ni3Al doped with 0.2 at. % Hf were performed in the temperature range 78-1230 K, in order to determine the lattice location of Hf atoms in the ordered γ′–Ni3Al structure. The two NQIs obtained are discussed within the present L12 cubic structure and a tetragonal distortion of L12 to another two DO22 and L60 type structures. The first low frequency NQI at the site of the 181Ta ion-probe after substitution of aluminum for hafnium in DO22 at ambient temperature, is vQ1(300 K) = 39(1) MHz with η1 = 0. The corresponding high frequency value on the second crystallographic site in L60, is vQ2(300 K) = 204(14) MHz with η2 = 0.47(11). These two NQI's have different temperature behavior. The presence of both DO22 and L60 tetragonal distortions of the parent cubic L12 lattice, detected after adding 0.2 at. % Hf, are with modulations to the lattice constant (a) with a ratio (c/a), 2.04 and 0.87, respectively. Ab initio calculations of electronic and structural properties and hyperfine parameters at the 181Ta ion probe of the γ′–Ni3Al–0.2 at. % Hf alloy were performed using the full potential augmented plane wave plus local-orbital (APW+lo) method as implemented in the WIEN2k code. The accuracy of the calculations and comparison with the experimental results enabled us to identify the observed hyperfine interactions and to infer the EFG sign that cannot be measured in conventional TDPAC measurements.
Palladium as electrode in DNA sequencing
Authors: Chen Xiang
Published: August 2013

We construct a molecular junction comprising two identical “reader” molecules that are each linked on one end to a DNA single base via hydrogen bonds and on the other end to a palladium electrode. The structure of the junction is thus palladium-reader-base-reader-palladium. The palladium-reader contacts occur via Pd-S bonds. We calculated the electronic structure and conductance of the molecular junctions. Compared with the performance of molecular junctions with gold or titanium nitride electrodes, the current-voltage characteristics of the molecular junctions with palladium electrodes show higher sensitivity to the identity of the bridging DNA base, allowing the DNA bases to be distinguished more easily. Therefore, palladium is a superior electrode for molecular electronics and DNA sequencing.
Thermal reversibility in electrical characteristics of ultraviolet/ozone-treated graphene
Authors: Mulyana Yana , Horita Masahiro , Ishikawa Yasuaki , Uraoka Yukiharu , Koh Shinji
Published: August 2013

Changes in electrical properties of a bilayer graphene-based field-effect transistor (G-FET) after being oxidized through ultraviolet (UV)/ozone (O3) treatment are presented. A decrease in conductivity and carrier mobility was observed after oxidation. However, electrical properties recovered after annealing oxidized G-FET with H2/Ar, indicating that oxidation with UV/O3 treatment was thermally reversible. Raman spectroscopy was conducted to verify that no defects were introduced after oxidation. The existence of chemical bonds between oxygen and graphene was confirmed from the X-ray photoelectron spectroscopy. Moreover, we found that graphene's sheet resistance increased after oxidation. Nevertheless, contact resistivity at graphene-Au/TiN electrode interface remained unchanged.
Graphene-based thin film supercapacitor with graphene oxide as dielectric spacer
Authors: Liu Jinzhang , Galpaya Dilini , Notarianni Marco , Yan Cheng , Motta Nunzio
Published: August 2013

Thin film supercapacitors are produced by using electrochemically exfoliated graphene (G) and wet-chemically produced graphene oxide (GO). Either G/GO/G stacked film or sole GO film are sandwiched by two Au films to make devices, where GO is the dielectric spacer. The addition of graphene film can increase the capacitance about two times, compared to the simple Au electrode. It is found that the GO film has very high dielectric constant, accounting for the high capacitance. AC measurement reveals that the relative permittivity of GO is in the order of 104 within the frequency range of 0.1–70 Hz.
Low-temperature solution-processed alumina as gate dielectric for reducing the operating-voltage of organic field-effect transistors
Authors: Peng Jun , Sun Qijun , Wang Suidong , Wang Hai-Qiao , Ma Wanli
Published: August 2013

We report a facile route for developing solution-processed Al2O3 film at low temperature (<180 °C) and its application in organic field-effect transistors (OFETs). Compared to OFETs using conventional SiO2 gate dielectric, the pentacene-based OFETs using Al2O3 thin film gate dielectric achieved comparable on-off drain current ratio (over 105), five times high field-effect mobility (∼2.7 cm2/Vs), threshold voltage of ∼−1.4 V and a greatly reduced operating voltage. The achieved low voltage operation can significantly reduce power consumption of OFETs. Furthermore, the low-temperature processing of the solution-processed Al2O3 film paves the way for fabricating organic electronic devices on flexible plastic substrates.
Improved visible solar absorber based on TiO2 nanotube film by surface-loading of plasmonic Au nanoparticles
Authors: Shao Zhufeng , Wang Xinshun , Ren Shoutian , Tian Zhaoshuo , Fan Shengli , Sun Shengsheng , Liu Shutian , Wang Qiang
Published: August 2013

Plasmon-driven electrons injection into active layers of optoelectronic devices is a promising and challenging research topic due to the great unavailability of suitable materials and devices configurations capable of providing comprehensively high photocurrent. In this letter, anodic TiO2 nanotubes array (TNA) films are formed to show enhanced visible light absorbing properties by surface-loading of isolated Au nanoparticles (NPs), exhibiting increased photocurrent and decreased response time. Surface Plasmon produces hot free electrons in the gold NPs when the device is illuminated by visible light with suitable photon energies, and the direct injection of hot electrons into TNA film is realized due to the energy nonequilibrium between gold NPs and TNA film. A significant fraction of these electrons will tunnel into the semiconductor's conduction band, which will introduce the surface n-type conduction layer, resulting in about 145% enhancement of photocurrent and 37% reduction of response time. A scattering-induced enhancement mechanism contributes effectively to the plasmonic photoresponse.
An experimental and theoretical investigation into the “worm-hole” effect
Authors: Zhao Liang , Su Jiancang , Zhang Xibo , Pan Yafeng , Wang Limin , Fang Jinpeng , Sun Xu , Li Rui , Zeng Bo , Cheng Jie
Published: August 2013

On a nanosecond time scale, solid insulators abnormally fail in bulk rather than on surface, which is termed as the “worm-hole” effect. By using a generator with adjustable output pulse width and dozens of organic glass (PMMA) and polystyrene (PS) samples, experiments to verify this effect are conducted. The results show that under short pulses of 10 ns, all the samples fail due to bulk breakdown, whereas when the pulse width is tuned to a long pulse of 7 μs, the samples fail as a result of surface flashover. The experimental results are interpreted by analyzing the conditions for the bulk breakdown and the surface flashover. It is found that under short pulses, the flashover threshold would be as high as the bulk breakdown strength (EBD) and the flashover time delay (td) would be longer than the pulse width (τ), both of which make the dielectrics' cumulative breakdown occur easily; whereas under long pulses, that Ef is much lower than EBD and td is smaller than τ is advantageous to the occurrence of the surface flashover. In addition, a general principle on solid insulation design under short pulse condition is proposed based on the experimental results and the theoretical analysis.
Giant magneto-optical Kerr effect in HfO2/Co/HfO2/Al/silicon structure
Authors: Zhang S. Y. , Gao J. L. , Xia W. B. , Luo X. J. , Tang S. L. , Du Y. W.
Published: August 2013

An extraordinary enhancement of magneto-optical Kerr effect was demonstrated in HfO2/Co/HfO2/Al/substrate composite structure by experimental measurements as well as theoretical calculations. Giant polar Kerr rotation was observed within a broad spectral region, and especially a peak of −7.92° was found at wavelength of 496 nm, which is nearly forty times as large as that of a single Co film. In addition, a Kerr rotation reversal was also observed in short wavelength region in the longitudinal geometry. We proposed that the multiple reflections and optical interference in the optical cavities lead to the enormous enhancement and modulation of the Kerr rotation.
Tunable wavevector and spin filtering in graphene induced by resonant tunneling
Authors: Lu Wei-Tao , Li Wen , Wang Yong-Long , Jiang Hua , Xu Chang-Tan
Published: August 2013

The resonant tunneling in graphene superlattices with an exchange field is studied theoretically. The results show that a resonant tunneling occurs in the transmission gap by virtue of the transverse wave vector. The position, width, and number of resonant tunneling can be effectively manipulated by adjusting the barrier strength, barrier width, and well width, respectively, which indicates the remarkable wavevector filtering behavior. This resonant effect together with the exchange splitting can be utilized to design an efficient spin filter. It is also found that the energy spectrum in the bound region displays bandlike distribution due to the coupling of eigenstates.
Size-dependent structural characteristics and phonon thermal transport in silicon nanoclusters
Authors: Li Hai-Peng , Zhang Rui-Qin
Published: August 2013

We investigate the size effects on the structures and thermal conductivity of silicon nanoclusters (SiNCs) using molecular dynamics simulations. We demonstrate that as the diameter of the SiNCs increases from 1.80 nm to 3.46 nm, the cluster structure changes from an amorphous state to a crystalline state at 300 K, which is in good agreement with the experimental findings. Our calculated thermal conductivity of the SiNCs shows a size-dependent effect due to the remarkable phonon-boundary scattering and can be about three orders of magnitude lower than that of bulk Si.
Figure of merit based maximization of the quantum efficiency of (single-wall-carbon-nanotubes/n-type silicon) hybrid photovoltaic devices
Authors: Le Borgne V. , Gautier L. A. , El Khakani M. A.
Published: August 2013

We report on a rational approach to optimize the photovoltaic (PV) properties of devices based on the hetero-nanojunctions formed between single wall carbon nanotubes (SWCNTs) films and n-silicon. By qualifying the optoelectronic properties of the SWCNT film through a figure of merit (FoM), we were able to correlate the latter to both the external quantum (EQE) and power conversion (PCE) efficiencies of associated PV devices. The established correlation guided us to achieve EQE values as high as ∼55%. Furthermore, it is found that higher FoM figures (≥3 × 10−6 Ω−1) lead to higher EQE and PCE values (with an increase of 15% and 2% per decade, respectively). Finally, by optimizing the EQE of the SWCNTs based PV devices and further doping them, we have achieved PCE values as high as ∼4%.
Fretibacter rubidus gen. nov., sp. nov., isolated from seawater
Authors: Cho Yong-Joon , Yi Hana , Seo Boram , Cho Kyeung Hee , Chun Jongsik
Published: August 2013

A brick-red-coloured, curved-rod-shaped, prostheca-bearing and non-motile bacterial strain, designated JC2236T, was isolated from a seawater sample of Jeju Island, Republic of Korea. 16S rRNA gene sequence analysis indicated that this strain belongs to the family

Hyphomonadaceae

and represents a distinct phyletic line that reflects a novel genus status within a clade containing the genera

Litorimonas

,

Hellea

,

Robiginitomaculum

and

Algimonas

. The predominant isoprenoid quinone (Q10) and polar lipid profile (phosphatidylglycerol, glucuronopyranosyl diglyceride and monoglycosyl diglyderide) were in line with those of most members of the family. However, the DNA G+C content (49.3 mol%), the abundance of C16 : 0, the requirement of sea salts for growth and absence of cell motility differentiated strain JC2236T from other closely related genera. Overall enzyme traits also demonstrated that the novel strain is not closely affiliated with any of the previously described genera. Thus, based on data from the present polyphasic taxonomic study, strain JC2236T is considered to represent a novel species of a new genus belonging to the family

Hyphomonadaceae

, for which the name Fretibacter rubidus gen. nov., sp. nov. is proposed. The type strain of Fretibacter rubidus is JC2236T ( = KACC 16935T = JCM 15585T).
Pseudoruegeria haliotis sp. nov., isolated from the gut of the abalone Haliotis discus hannai
Authors: Hyun Dong-Wook , Shin Na-Ri , Kim Min-Soo , Kim Pil Soo , Kim Joon Yong , Whon Tae Woong , Bae Jin-Woo
Published: August 2013

A novel Gram-negative, aerobic, non-motile and rod-shaped bacterium, designated strain WM67T, was isolated from the gut of an abalone (Haliotis discus hannai) collected from the northern coast of Jeju Island in Korea. Phylogenetic analyses based on the 16S rRNA gene sequence indicated that strain WM67Tclustered in the genusPseudoruegeria, and the highest sequence similarity was shared withPseudoruegeria lutimaris(98.0 % similarity to the type strain). Optimal growth of the isolate occurred at 30 °C, pH 7–8 and with 1 % (w/v) NaCl. The major cellular fatty acids were summed feature 8 (C18 : 1ω7cand/or C18 : 1ω6c) and C16 : 0. Ubiquinone Q-10 was the major respiratory quinone. The polar lipids of strain WM67Tcomprised phosphatidylserine, phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, an unidentified glycolipid and three unidentified lipids. The genomic DNA G+C content was 66.5 mol%. DNA–DNA hybridization indicated <17 % genomic relatedness to other members of the genusPseudoruegeria. The physiological, biochemical, chemotaxonomic and genotypic analyses indicated that strain WM67Trepresents a novel species ofPseudoruegeria, for which the namePseudoruegeria haliotissp. nov. is proposed. The type strain is WM67T( = KACC 17214T = JCM 18872T).
Novel proteomic approach (PUNCH-P) reveals cell cycle-specific fluctuations in mRNA translation
Authors: Aviner Ranen , Geiger Tamar , Elroy-Stein Orna
Published: August 2013

Monitoring protein synthesis is essential to our understanding of gene expression regulation, as protein abundance is thought to be predominantly controlled at the level of translation. Mass-spectrometric and RNA sequencing methods have been recently developed for investigating mRNA translation at a global level, but these still involve technical limitations and are not widely applicable. In this study, we describe a novel system-wide proteomic approach for direct monitoring of translation, termed puromycin-associated nascent chain proteomics (PUNCH-P), which is based on incorporation of biotinylated puromycin into newly synthesized proteins under cell-free conditions followed by streptavidin affinity purification and liquid chromatography-tandem mass spectrometry analysis. Using PUNCH-P, we measured cell cycle-specific fluctuations in synthesis for >5000 proteins in mammalian cells, identified proteins not previously implicated in cell cycle processes, and generated the first translational profile of a whole mouse brain. This simple and economical technique is broadly applicable to any cell type and tissue, enabling the identification and quantification of rapid proteome responses under various biological conditions.
Analysis and correction of crosstalk effects in pathway analysis
Authors: Donato Michele , Xu Zhonghui , Tomoiaga Alin , Granneman James G. , MacKenzie Robert G. , Bao Riyue , Than Nandor Gabor , Westfall Peter H. , Romero Roberto , Draghici Sorin
Published: August 2013

Identifying the pathways that are significantly impacted in a given condition is a crucial step in understanding the underlying biological phenomena. All approaches currently available for this purpose calculate a P-value that aims to quantify the significance of the involvement of each pathway in the given phenotype. These P-values were previously thought to be independent. Here we show that this is not the case, and that many pathways can considerably affect each other's P-values through a “crosstalk” phenomenon. Although it is intuitive that various pathways could influence each other, the presence and extent of this phenomenon have not been rigorously studied and, most importantly, there is no currently available technique able to quantify the amount of such crosstalk. Here, we show that all three major categories of pathway analysis methods (enrichment analysis, functional class scoring, and topology-based methods) are severely influenced by crosstalk phenomena. Using real pathways and data, we show that in some cases pathways with significant P-values are not biologically meaningful, and that some biologically meaningful pathways with nonsignificant P-values become statistically significant when the crosstalk effects of other pathways are removed. We describe a technique able to detect, quantify, and correct crosstalk effects, as well as identify independent functional modules. We assessed this novel approach on data from four experiments involving three phenotypes and two species. This method is expected to allow a better understanding of individual experiment results, as well as a more refined definition of the existing signaling pathways for specific phenotypes.
Ankle‐Brachial Index and Cardiovascular Mortality in Nondiabetic Hemodialysis Patients
Authors: Bevc Sebastjan , Purg Darinka , Turnšek Nina , Hren Martin , Hojs Nina , Zorman Tadej , Pečovnik‐Balon Breda , Dvoršak Benjamin , Ekart Robert , Hojs Radovan
Published: August 2013

Atherosclerosis is a leading cause of morbidity and mortality in hemodialysis (HD) patients. Low (<0.90) and high (>1.40) ankle‐brachial index (ABI) is known as a non‐invasive diagnostic marker for generalized atherosclerosis associated with higher cardiovascular (CV) mortality in the general population. Less is known about associations between ABI and CV mortality in HD patients. The aim of our study was to determine the impact of the ABI on CV mortality in nondiabetic HD patients. Fifty‐two nondiabetic HD patients (mean age 59 years, range 22 – 76 years) were enrolled in our study. Twenty‐three (44%) were women and 29 (56%) men. The ABI was determined using an automated, non‐invasive, waveform analysis device. All patients were divided according to the ABI into three groups: low ABI (<0.9), normal ABI (0.9–1.4) and high ABI (>1.4). The presence of arterial hypertension and smoking was established. Serum cholesterol (HDL and LDL) and triglycerides were measured by routine laboratory methods. Survival rates were analyzed using Kaplan–Meier survival curves. The Cox regression model was used to assess the influence of the ABI on CV outcomes. The model was adjusted for age, arterial hypertension, smoking, cholesterol and triglycerides. Mean ABI value was 1.2 ± 0.3 (range 0.2–2.2). Patients were observed from the date of the ABI measurement until their death or maximally up to 1620 days. Kaplan–Meier survival analysis showed that the risk for CV death was higher for HD patients with low and high ABI compared to normal ABI (log rank test: P < 0.006; P < 0.0001). In the adjusted Cox multivariable regression model low and high ABI (P < 0.011; P < 0.003) remained predictors of mortality in our patients. The results indicate a U‐shaped association between the ABI and CV mortality in nondiabetic HD patients and showed that low and high ABI were directly associated with higher mortality of our patients.
Radiographic Assessment of Vascular Calcification, Aortic Pulse Wave Velocity, Ankle‐Brachial Index and Fibroblast Growth Factor‐23 in Chronic Hemodialysis Patients
Authors: Breznik Silva , Ekart Robert , Hren Martin , Rupreht Mitja , Balon Breda Pečovnik
Published: August 2013

Vascular calcification is a frequent complication of chronic kidney disease and end stage renal disease. In both the general population and patients with end stage renal disease, vascular calcification is related to arterial stiffness and is a predictor of cardiovascular morbidity and mortality. Various diagnostic methods are currently used to assess vascular calcification. There is a preference for simple, reliable methods that can be used in daily practice. Therefore, several imaging and laboratory methods are investigated. Twenty‐eight patients with mean age of 62 years on chronic hemodialysis were enrolled in the study. The mean duration of hemodialysis treatment was 70 months (range 3 to 350 months). Vascular calcification was assessed with coronary computed tomography and lateral lumbar, pelvic and hand radiographs. Vascular stiffness was evaluated using aortic pulse wave velocity and ankle‐brachial index measurements, and finally serum levels of fibroblast growth factor‐23 were followed. A statistically significant correlation was demonstrated between all the following parameters: coronary artery calcification score, aortic pulse wave velocity, abdominal aortic calcification score, simple vascular calcification scores in pelvis and hand. A statistically significant correlation of ankle‐brachial index >1.3 to coronary artery calcification score was found. There was no correlation between the previous parameters and fibroblast growth factor‐23. The results of our study indicate that simple imaging methods could provide confident vascular damage assessment and therefore potentially guide therapy adjustments. An association between fibroblast growth factor‐23 and the other diagnostic modalities in our study was not found.
Ascorbic Acid for the Prevention of Contrast‐Induced Nephropathy After Coronary Angiography in Patients With Chronic Renal Impairment: A Randomized Controlled Trial
Authors: Dvoršak Benjamin , Kanič Vojko , Ekart Robert , Bevc Sebastjan , Hojs Radovan
Published: August 2013

To determine the incidence of contrast‐induced nephropathy (CIN) and to assess the effectiveness of ascorbic acid in the prevention of CIN after coronary angiography in patients with chronic renal impairment. CIN is the third most common cause of hospital‐acquired renal failure. It is well documented that periprocedural hydration is effective in the prevention of CIN. Little data exist on the effectiveness of ascorbic acid, a vitamin with antioxidative action. Patients with stable serum creatinine level >107 μmol/L (n = 81) undergoing coronary angiography were randomized to receive either ascorbic acid (N = 40) or placebo (N = 41) before the procedure. All patients received intravenous volume expansion with normal saline before the procedure. CIN was defined as an increase of serum creatinine level >25% from baseline measured 3 to 4 days after the procedure. CIN occurred totally in 5/81 patients (6.2%); in two patients (3%) in the ascorbic acid group and in three patients (7.3%) in the placebo group (P = 0.512). Postprocedural worsening of renal function (postprocedural increase of serum creatinine level) was present in 10/81 patients (12.3%) in the ascorbic acid group and in 19/81 patients (23.4%) in the placebo group (P = 0.038). No patient required dialysis treatment. We found no statistically significant impact of ascorbic acid on the incidence of CIN in patients with chronic renal impairment undergoing coronary arteriography or angioplasty. Ascorbic acid may still have some protective role in CIN reflected in lower incidence of worsening of renal function in the treated group.
Reasons for Refusing Kidney Transplantation Among Chronic Dialysis Patients
Authors: Nizič‐Kos Tea , Ponikvar Anja , Buturović‐Ponikvar Jadranka
Published: August 2013

The aim of the prospective clinical study was to evaluate the reasons for refusing kidney transplantation among chronic dialysis patients. A total of 164 adult chronic dialysis patients participated in the study. They were asked to complete a detailed questionnaire on specific issues regarding transplantation. The mean age was 60.9 ± 16.0 (20–89) years, 61.6% were male, 11.6% had had a previous transplant. The majority, that is, 72.0%, of the patients believed that transplantation improved the quality of life, and 55.5% believed that transplantation prolonged life. Nevertheless, 45.0% of the patients wanted to be transplanted, 35.0% refused transplantation, and 20.0% were undecided. Patients refusing transplantation were significantly older compared to the patients wanting to be transplanted (67 ± 16 vs. 57 ± 16 years; P < 0.001). The main reasons for refusing transplantation (57 patients) were the side‐effects of immunosuppressive therapy (31.6%), unpredictability of transplant outcome (29.8%), and unfavorable outcomes in fellow patients (28.1%). The side‐effects of immunosuppressive therapy that patients were most concerned about included mobility problems (29.8%), new‐onset diabetes (26.3%), increased risk of severe infections (26.3%), problems with vision (22.8%), and increased risk of cancer (21.1%). Many patients did not want to accept organs from expanded criteria donors (ECD) (44.6% of the patients wanting and 64.9% of those refusing transplantation). The majority believed that patients should be informed if an organ from an ECD donor is being offered (64.9% of patients wanting and 63.2% of those refusing transplantation). The main reasons for refusing kidney transplantation were the side‐effects of immunosuppressive therapy, unpredictability of transplant outcome, and unfavorable outcomes in fellow patients.
Permanent Genetic Resources added to Molecular Ecology Resources Database 1 April 2013–31 May 2013
Authors:   Molecular Ecology Resources Primer Development Consortium, Agostini Cecilia , Albaladejo R. G. , Aparicio A. , Arthofer Wolfgang , Berrebi P. , Boag Peter T. , Carbone Ignazio , Conroy Gabriel C. , Cortesero A. M. , Costa Gonçalves Evonnildo , Costa Diogo , Couto Alvarina , De Girolamo MIrko , Du Hao , Fu Shi‐Jian , Garrido‐Garduño T. , Gettová L. , Gilles A. , Guerreiro Hamoy Igor , Herrera C. M. , Heussler Carina , Isidro Eduardo , Josso C. , Krapf Patrick , Lamont Robert W. , Le Ralec A. , Lopes Susana , Luís Carla , Luo Hui , Mahéo F. , Marino Ilaria A. M. , Mieuzet L. , Murray Brent W. , Ogbourne Steven M. , Pallavicini Alberto , Parejo‐Farnés C. , Patarnello Tomaso , Paty C. , Pereira Carolina , Pinho Catarina , Pinto Pablo , Poinsot D. , Powell Adrienne , Putman Alexander I. , Santoro André , Santos Sidney , Schlick‐Steiner Birgit C. , Scott Candace , Silvanira Barbosa Maria , Šimková A. , Simon J.‐C. , Solé‐Cava Antonio , Steiner Florian M. , Sun Zhengxin , Torboli Valentina , Tredway Lane P. , Van Coeverden de Groot Peter J. , Vasconcellos Anderson , Vázquez‐Domínguez E. , Wang Deng‐Qiang , Wang Yu‐Xiang , Wei Qi‐Wei , Zane Lorenzo , Zhang Shu‐Huan
Published: August 2013

This article documents the addition of 234 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Acipenser sinensis, Aleochara bilineata, Aleochara bipustulata, Barbus meridionalis, Colossoma macropomum, Delia radicum, Drosophila nigrosparsa, Fontainea picrosperma, Helianthemum cinereum, Liomys pictus, Megabalanus azoricus, Pelteobagrus vachelli, Pleuragramma antarcticum, Podarcis hispanica type 1A, Sardinella brasiliensis and Sclerotinia homoeocarpa. These loci were cross‐tested on the following species: Acipenser dabryanus, Barbus balcanicus, Barbus barbus, Barbus cyclolepis, Drosophila hydei, Drosophila melanogaster, Drosophila obscura, Drosophila subobscura, Fontainea australis, Fontainea fugax, Fontainea oraria, Fontainea rostrata, Fontainea venosa, Podarcis bocagei, Podarcis carbonelli, Podarcis liolepis, Podarcis muralis and Podarcis vaucheri.
Comparison of relative TLR‐2 and TLR‐4 expression level of disease and healthy gingival tissue of smoking and non‐smoking patients and periodontally healthy control patients
Authors: Fatemi K , Radvar M , Rezaee A , Rafatpanah H , Azangoo khiavi H , Dadpour Y , Radvar N
Published: August 2013

Background

Toll‐like receptors are a family of sensor proteins that induce the inflammatory diseases in context of microbial infection. The role of these proteins in periodontal disease and their interaction with smoking status are yet to be investigated. The aim of the present study was to evaluate the effect of smoking on gene expression of toll like receptor 2 (TLR‐2) and toll‐like receptor 4 (TLR‐4) in patients with periodontitis.

Methods

RNAs were extracted from gingival biopsies of healthy sites (no bleeding on probing and pocket depth ≤3 mm) as well as diseased sites (with bleeding on probing and pocket depth ≥5 mm) of 20 smoker and 17 non‐smoker subjects with chronic periodontitis. Gingival biopsies from eight periodontally healthy, never‐smoker subjects served as control. Real‐time PCR was carried out to evaluate the relative quantities of TLR‐2 and TLR‐4 mRNA concentrations.

Results

Regardless of smoking status, the relative expression levels of TLR‐2 and TLR‐4 were significantly greater (about 3 fold) at diseased sites compared to healthy sites of patients with periodontitis and healthy controls (p < 0.05). In sites with periodontitis, smoking caused an increase of about 6.5 fold in mRNA levels of TLR‐4 in gingival tissue (p < 0.05).

Conclusions

Although periodontitis might significantly increase TLR‐2 and TLR‐4 gene expression in gingival tissues, smoking habit in periodontitis subjects could selectively potentiate TLR‐4 gene expression.
Application of chlorhexidine, fluoride and artificial saliva during radiotherapy: an in vitro study of microleakage in Class V restorations
Authors: López Jornet P , Camacho Alonso F , Molina Miñano F
Published: August 2013

Background

The aim of this study was to evaluate the effect on microleakage in Class V restorations of daily applications of artificial saliva, fluoride mouthrinses and chlorhexidine to irradiated bovine teeth.

Methods

Class V cavities were created in 60 bovine teeth. The teeth were divided randomly into two groups: the first group (n = 30) was subjected to radiotherapy until the teeth had received a total accumulated dose of 60 Gy; the second group (n = 30) was used as a control group. Both groups were divided into three subgroups (n = 10): in Group A teeth were submerged in Xeros Dentaid® artificial saliva; Group B teeth were submerged in a solution of 1% amine fluoride; Group C teeth were submerged in 0.12% chlorhexidine. All treatments were applied three times a day for six weeks. Afterwards microleakage into the composite restorations was measured using MIP4 image software.

Results

It was seen that radiation caused increases in microleakage in composite restorations. Statistically significant differences were found in the artificial saliva group (p = 0.013) and the chlorhexidine group (p = 0.023).

Conclusions

Microleakage in composite restorations was greater among radiated teeth.
A Natural Experiment in Proposal Power and Electoral Success
Authors: Loewen Peter John , Koop Royce , Settle Jaime , Fowler James H.
Published: August 2013

Does lawmaker behavior influence electoral outcomes? Observational studies cannot elucidate the effect of legislative proposals on electoral outcomes, since effects are confounded by unobserved differences in legislative and political skill. We take advantage of a unique natural experiment in the Canadian House of Commons that allows us to estimate how proposing legislation affects election outcomes. The right of noncabinet members to propose legislation is assigned by lottery. Comparing outcomes between those who were granted the right to propose and those who were not, we show that incumbents of the governing party enjoy a 2.7 percentage point bonus in vote total in the election following their winning the right to introduce a single piece of legislation, which translates to a 7% increase in the probability of winning. The causal effect results from higher likeability among constituents. These results demonstrate experimentally that what politicians do as lawmakers has a causal effect on electoral outcomes.
Measurement of heat and moisture exchanger efficiency
Authors: Chandler M.
Published: August 2013

Deciding between a passive heat and moisture exchanger or active humidification depends upon the level of humidification that either will deliver. Published international standards dictate that active humidifiers should deliver a minimum humidity of 33 mg.l−1; however, no such requirement exists, for heat and moisture exchangers. Anaesthetists instead have to rely on information provided by manufacturers, which may not allow comparison of different devices and their clinical effectiveness. I suggest that measurement of humidification efficiency, being the percentage moisture returned and determined by measuring the temperature of the respired gases, should be mandated, and report a modification of the standard method that will allow this to be easily measured. In this study, different types of heat and moisture exchangers for adults, children and patients with a tracheostomy were tested. Adult and paediatric models lost between 6.5 mg.l−1 and 8.5 mg.l−1 moisture (corresponding to an efficiency of around 80%); however, the models designed for patients with a tracheostomy lost between 16 mg.l−1 and 18 mg.l−1 (60% efficiency). I propose that all heat and moisture exchangers should be tested in this manner and percentage efficiency reported to allow an informed choice between different types and models.
The role of native woody species in the restoration of Campos Rupestres in quarries
Authors: Le Stradic Soizig , Buisson Elise , Negreiros Daniel , Campagne Pascal , Wilson Fernandes Geraldo
Published: August 2013

Questions

Can shrub and tree seedlings be reintroduced into an extremely harsh environment through transplantation? Does the growth strategy of species affect their survival? What factors influence transplantation success? Do transplanted species influence their immediate vicinity, e.g. promote native species colonization?

Location

Campos Rupestres, Minas Gerais, Brazil.

Methods

We studied the reintroduction of four native tree and 14 native shrub species. Their transplantation success (survival, growth and reproduction) and their impact on their immediate vicinity (understorey composition, soil surface indicators, e.g. cover of moss, biological crust, bare ground, litter, herbaceous cover and soil characteristics) were assessed 4.5 yrs after transplantation.

Results

While some transplanted species had low survival (<30%), half of them had survival of >78% 4.5 yrs after transplantation. Plant growth was barely correlated with transplantation success in such a harsh environment. Transplanted species did not influence soil and understorey plant composition but significantly impacted soil surface indicators. The shrub species with higher survival usually allowed establishment of an understorey herbaceous cover, which may increase soil erosion control. This is also true for some species for which the survival was <40%: Diplusodon orbicularis (survival: 39%) and Lavoisiera campos‐portoana (37%). Crown volume had a direct effect on light reaching the soil (e.g. Jacaranda caroba or Collaea cipoensis had a less dense canopy more permeable to light, allowing the development of understorey species). On the other hand, crown volume was positively correlated with amount of litter: Fabaceae, e.g. Chamaecrista semaphora and Mimosa foliolosa, had denser canopy and produced a thick layer of litter, limiting herbaceous species establishment. Three tree species (Enterolobium ellipticum, Kielmeyera petiolaris and Zeyhera tuberculosa) neither had high survival nor facilitated establishment of herbaceous cover. The layout and spacing of species and individuals must thus be considered carefully to ensure recolonization by native shrub and herbaceous species.

Conclusion

This study demonstrates the practical efficiency of using some species native to harsh tropical ecosystems, e.g. Campos Rupestres, to restore quarry ecosystems in terms of their transplantation success, effects on both the establishment of herbaceous species and soil conservation.
Enjoying mathematics or feeling competent in mathematics? Reciprocal effects on mathematics achievement and perceived math effort expenditure
Authors: Pinxten Maarten , Marsh Herbert W. , De Fraine Bieke , Van Den Noortgate Wim , Van Damme Jan
Published: August 2013

Background

The multidimensionality of the academic self‐concept in terms of domain specificity has been well established in previous studies, whereas its multidimensionality in terms of motivational functions (the so‐called affect‐competence separation) needs further examination.

Aim

This study aims at exploring differential effects of enjoyment and competence beliefs on two external validity criteria in the field of mathematics.

Sample

Data analysed in this study were part of a large‐scale longitudinal research project. Following a five‐wave design, math enjoyment, math competence beliefs, math achievement, and perceived math effort expenditure measures were repeatedly collected from a cohort of 4,724 pupils in Grades 3–7.

Method

Confirmatory factor analysis (CFA) was used to test the internal factor structure of the math self‐concept. Additionally, a series of nested models was tested using structural equation modelling to examine longitudinal reciprocal interrelations between math competence beliefs and math enjoyment on the one hand and math achievement and perceived math effort expenditure on the other.

Results

Our results showed that CFA models with separate factors for math enjoyment and math competence beliefs fit the data substantially better than models without it. Furthermore, differential relationships between both constructs and the two educational outcomes were observed. Math competence beliefs had positive effects on math achievement and negative effects on perceived math effort expenditure. Math enjoyment had (mild) positive effects on subsequent perceived effort expenditure and math competence beliefs.

Conclusion

This study provides further support for the affect‐competence separation. Theoretical issues regarding adequate conceptualization and practical consequences for practitioners are discussed.
Cellular immune dysfunction in immune thrombocytopenia (ITP)
Authors: McKenzie Christopher G. J. , Guo Li , Freedman John , Semple John W.
Published: August 2013

Over the past decades, a wealth of information has been reported about the pathogenic features of immune thrombocytopenia (ITP). To this day, however, it is unclear whether the immune abnormalities associated withITPplay causative roles in the disease or are secondary epiphenomena brought on by the inflammatory processes that are associated with the disorder. Like the majority of all autoimmune diseases,ITPis an organ‐specific disease and abnormalities in immune cell types, such as antigen‐presenting cells (APC),Tcells andBcells have been shown to play some sort of role in the initiation and/or perpetuation of the disease. This review will discuss recent advances in understanding three immune cells important inITPpathophysiology:APC, T cells and B cells, and will review how they interact with each other to initiate and perpetuateITP, particularly the chronic form of the disorder. It will also focus on new data related to the genetics of the disorder and discuss relevant animal models ofITP.