bluuebunny/crossref_metadata_2025 huggingface dataset:
Highly Dispersed TiO6 Units in a Layered Double Hydroxide for Water Splitting
Authors: Zhao Yufei , Chen Pengyun , Zhang Bingsen , Su Dang Sheng , Zhang Shitong , Tian Lei , Lu Jun , Li Zhuoxin , Cao Xingzhong , Wang Baoyi , Wei Min , Evans David G. , Duan Xue
Published: August 2012

A family of photocatalysts for water splitting into hydrogen was prepared by distributing TiO6 units in an MTi‐layered double hydroxide matrix (M=Ni, Zn, Mg) that displays largely enhanced photocatalytic activity with an H2‐production rate of 31.4 μmol h−1 as well as excellent recyclable performance. High‐angle annular dark‐field scanning transmission electron microscopy (HAADF‐STEM) mapping and XPS measurement reveal that a high dispersion of TiO6 octahedra in the layered doubled hydroxide (LDH) matrix was obtained by the formation of an M2+‐O‐Ti network, rather different from the aggregation state of TiO6 in the inorganic layered material K2Ti4O9. Both transient absorption and photoluminescence spectra demonstrate that the electron–hole recombination process was significantly depressed in the Ti‐containing LDH materials relative to bulk Ti oxide, which is attributed to the abundant surface defects that serve as trapping sites for photogenerated electrons verified by positron annihilation and extended X‐ray absorption fine structure (EXAFS) techniques. In addition, a theoretical study on the basis of DFT calculations demonstrates that the electronic structure of the TiO6 units was modified by the adjacent MO6 octahedron by means of covalent interactions, with a much decreased bandgap of 2.1 eV, which accounts for its superior water‐splitting behavior. Therefore, the dispersion strategy for TiO6 units within a 2D inorganic matrix can be extended to fabricate other oxide or hydroxide catalysts with greatly enhanced performance in photocatalysis and energy conversion.
Development of Domino Processes by Using 7‐Silylcycloheptatrienes and Its Analogues
Authors: Beniazza Redouane , Desvergnes Valérie , Girard Emeline , Kauffmann Brice , Berlande Muriel , Landais Yannick
Published: August 2012

7‐Silyl‐ and 7‐silylmethylcycloheptatrienes were shown to react with acylnitroso reagents at room temperature, through their norcaradiene forms, to generate the corresponding cycloadducts 5 a–b and 6 a–b as single diastereomers. The course of the reaction was dramatically modified by changing the reaction conditions. Using a polar medium, functionalized cyclohexa‐1,3‐dienes 7 a–b and bicyclic compounds 13 a–b were instead generated, incorporating one or two amino groups. Similar behavior was observed by using other dienophiles, including triazolinedione, but also activated aldehydes and ketones. A tentative mechanism has been proposed to rationalize the formation of both classes of products that relies on a domino process involving four consecutive elementary steps, in this order: 1) electrocyclic process, 2) hetero‐Diels–Alder reaction, 3) cyclopropane ring opening, and 4) hetero‐Diels–Alder reaction. Trapping of the cationic intermediate and isolation of the primary cycloadduct provide support for this hypothesis. An enantioselective version of the cascade using cycloheptatriene 4 b and aldehydes and ketones, under copper(II) catalysis was also carried out, leading to cyclohexa‐1,3‐dienes 21, 28, and 30 with enantioselectivities up to 93 % ee. Finally, elaboration of the intermediates above has been carried out, opening a straightforward access to sugar mimics 42–43 and complex polycyclic systems 36 and 39.
Increasing the Biomass Flexibility for Power Plants
Authors: Vodegel Stefan , Gehrmann Hans‐Joachim , Bernhardt Daniel , Lyczkowska Angelika
Published: August 2012

Biomasseheizkraftwerke werden in Europa vorzugsweise mit Holz betrieben, das aber weltweit nur begrenzt verfügbar ist. Schon jetzt führt eine Verknappung zu einer Verteuerung und damit zu wirtschaftlichen Herausforderungen bei den Betreibern. Daher wird nach alternativen biogenen Einsatzstoffen gesucht. Der möglicherweise kostengünstigeren Beschaffung gegenüber Holz stehen jedoch deren Verbrennungseigenschaften gegenüber, die zu Verschlackung, Korrosion und zusätzlichen Emissionswerten führen können. Über eine prozessorientierte Bewertung von neuen biogenen Brennstoffen in unterschiedlichen thermischen Prozessen werden Chancen und Risiken aufgezeigt, wie sie verstärkt im Markt eingeführt werden können. Dabei spielen nicht nur verfahrenstechnische Gesichtspunkte eine Rolle, sondern auch die Frage, inwieweit sich Nährstoffe zurückgewinnen lassen, um einen Beitrag zur Ressourceneffizienz zu leisten.
Separation of Tin in Recycling of Lead Batteries
Authors: Stelter Michael , Morgenstern Gunter , Beimel Bruno , Zeidler Oliver
Published: August 2012

Der gegenwärtig anfallende Akkumulatorenschrott besitzt höhere Zinngehalte als die Bleilegierungen moderner Akkumulatoren. Dadurch fallen bei der Aufarbeitung des Akkuschrotts blei/zinnhaltige Raffinationsprodukte an, die nicht in den Wertstoffkreislauf zurückgeführt werden können. Es wird eine Möglichkeit zur Trennung dieser Produkte beschrieben. Damit hat der Recycler die Möglichkeit, die Wertstoffe Zinn und Blei der Wirtschaft wieder getrennt zur Verfügung zu stellen.
Gram‐Scale Solution‐Phase Synthesis of Selective Sodium Bicarbonate Co‐transport Inhibitor S0859: in vitro Efficacy Studies in Breast Cancer Cells
Authors: Larsen Ann M. , Krogsgaard‐Larsen Niels , Lauritzen Gitte , Olesen Christina W. , Honoré Hansen Steen , Boedtkjer Ebbe , Pedersen Stine F. , Bunch Lennart
Published: August 2012

Na+‐coupled HCO3− transporters (NBCs) mediate the transport of bicarbonate ions across cell membranes and are thus ubiquitous regulators of intracellular pH. NBC dysregulation is associated with a range of diseases; for instance, NBCn1 is strongly up‐regulated in a model of ErbB2‐dependent breast cancer, a malignant and widespread cancer with no targeted treatment options, and single‐nucleotide polymorphisms in NBCn1 genetically link to breast cancer development and hypertension. The N‐cyanosulfonamide S0859 has been shown to selectively inhibit NBCs, and its availability on the gram scale is therefore of significant interest to the scientific community. Herein we describe a short and efficient synthesis of S0859 with an overall yield of 45 % from commercially available starting materials. The inhibitory effect of S0859 on recovery of intracellular pH after an acid load was verified in human and murine cancer cell lines in Ringer solutions. However, S0859 binds very strongly to components in plasma, and accordingly, measurements on isolated murine tissues showed no effect of S0859 at concentrations up to 50 μM.
Obesity at diagnosis is associated with inferior outcomes in hormone receptor‐positive operable breast cancer
Authors: Sparano Joseph A. , Wang Molin , Zhao Fengmin , Stearns Vered , Martino Silvana , Ligibel Jennifer A. , Perez Edith A. , Saphner Tom , Wolff Antonio C. , Sledge George W. , Wood William C. , Fetting John , Davidson Nancy E.
Published: August 2012

BACKGROUND:

Obesity has been associated with inferior outcomes in operable breast cancer, but the relation between body mass index (BMI) and outcomes by breast cancer subtype has not been previously evaluated.

METHODS:

The authors evaluated the relation between BMI and outcomes in 3 adjuvant trials coordinated by the Eastern Cooperative Oncology Group that included chemotherapy regimens with doxorubicin and cyclophosphamide, including E1199, E5188, and E3189. Results are expressed as hazard ratios (HRs) from Cox proportional hazards models (HR >1 indicates a worse outcome). All P values are 2‐sided.

RESULTS:

When evaluated as a continuous variable in trial E1199, increasing BMI within the obese (BMI, ≥30 kg/m2) and overweight (BMI, 25‐29.9 kg/m2) ranges was associated with inferior outcomes in hormone receptor‐positive, human epidermal growth receptor 2 (HER‐2)/neu‐negative disease for disease‐free survival (DFS; P = .0006) and overall survival (OS; P = .0007), but not in HER‐2/neu–overexpressing or triple‐negative disease. When evaluated as a categorical variable, obesity was associated with inferior DFS (HR, 1.24; 95% confidence interval [CI], 1.06‐1.46; P = .0008) and OS (HR, 1.37; 95% CI, 1.13‐1.67; P = .002) in hormone receptor‐positive disease, but not other subtypes. In a model including obesity, disease subtype, and their interaction, the interaction term was significant for OS (P = .02) and showed a strong trend for DFS (P = .07). Similar results were found in 2 other trials (E5188, E3189).

CONCLUSIONS:

In a clinical trial population that excluded patients with significant comorbidities, obesity was associated with inferior outcomes specifically in patients with hormone receptor‐positive operable breast cancer treated with standard chemohormonal therapy. Cancer 2012. © 2012 American Cancer Society.
Influence of bypass angles on extracardiac Fontan connections: a numerical study
Authors: Ding Jinli , Liu Youjun , Wang Feng
Published: August 2012

The extracardiac Fontan connection (EFC) is an effective treatment for congenital single ventricle heart defects. Numerous studies have sought to optimize the EFC design. However, the optimal design of EFC remains uncertain. This study aims to examine the influence of bypass angles between the inferior vena cava (IVC) and right pulmonary artery (RPA), and the angles between the IVC and superior vena cava (SVC), on hemodynamics. Furthermore, this study demonstrates a methodology for cardiovascular surgical planning. First, a three‐dimensional anatomical geometry was reconstructed from the medical images of a patient with single ventricle heart defects. Second, based on haptic deformations, six computational models were virtually generated. Third, numerical simulations were conducted using computational fluid dynamics through the finite volume method. Finally, hemodynamic parameters were obtained and evaluated. The hemodynamic parameters, including the flow patterns, streamlines, and swirling flow, were obtained. Meanwhile, the energy loss and flow distributions of vena cava blood were calculated. First, the hepatic artery blood distribution to two lungs and the flow ratio of the left pulmonary artery to RPA are sensitive to the angle between the IVC and RPA and not to that between the IVC and SVC. Second, energy dissipation is mainly sensitive to the angle between the IVC and SVC and not to that between the IVC and RPA. Third, an appropriate increase in the angle between the IVC and RPA or that between the IVC and SVC may lead to optimal options. This study is useful for surgeons in evaluating optimal Fontan options. Copyright © 2012 John Wiley & Sons, Ltd.
Hyperfine Coupling Constants on Inner‐Sphere Water Molecules of GdIII‐Based MRI Contrast Agents
Authors: Esteban‐Gómez David , de Blas Andrés , Rodríguez‐Blas Teresa , Helm Lothar , Platas‐Iglesias Carlos
Published: August 2012

Herein we present a theoretical investigation of the hyperfine coupling constants (HFCCs) on the inner‐sphere water molecules of [Gd(H2O)8]3+ and different GdIII‐based magnetic resonance imaging contrast agents such as [Gd(DOTA)(H2O)]−, [Gd(DTPA)(H2O)]2−, [Gd(DTPA‐BMA)(H2O)] and [Gd(HP‐DO3A)(H2O)]. DFT calculations performed on the [Gd(H2O)8]3+ model system show that both hybrid‐GGA functionals (BH&HLYP, B3PW91 and PBE1PBE) and the hybrid meta‐GGA functional TPSSh provide 17O HFCCs in close agreement with the experimental data. The use of all‐electron relativistic approaches based on the DKH2 approximation and the use of relativistic effective core potentials (RECP) provide results of essentially the same quality. The accurate calculation of HFCCs on the [Gd(DOTA)(H2O)]−, [Gd(DTPA)(H2O)]2−, [Gd(DTPA‐BMA)(H2O)] and [Gd(HP‐DO3A)(H2O)] complexes requires an adequate description of solvent effects. This was achieved by using a mixed cluster/continuum approach that includes explicitly two second‐sphere water molecules. The calculated isotropic 17O HFCCs (Aiso) fall within the range 0.40–0.56 MHz, and show deviations from the corresponding experimental values typically lower than 0.05 MHz. The Aiso values are significantly affected by the distance between the oxygen atom of the coordinated water molecule and the GdIII ion, as well as by the orientation of the water molecule plane with respect to the Gd‐O vector. 1H HFCCs of coordinated water molecules and 17O HFCCs of second‐sphere water molecules take values close to zero.
Novel Multifunctional Graphene Sheets with Encased Au/Ag Nanoparticles for Advanced Electrochemical Analysis of Organic Compounds
Authors: Pruneanu Stela , Biris Alexandru R. , Pogacean Florina , Lazar Diana Mihaela , Ardelean Stefania , Watanabe Fumyia , Dervishi Enkeleda , Biris Alexandru S.
Published: August 2012

This work is the first presentation of the synthesis of few‐layer graphene decorated with gold and silver nanoparticles (Gr–Au–Ag) by chemical vapor deposition over a catalytic system formed of bimetallic Au–Ag nanoclusters supported on MgO and with methane used as the source of carbon. The sheetlike morphology of the graphene nanostructures, with mean sizes in the range of hundreds of nanometers, was observed by high‐resolution electron microscopy. The distinctive feature found in all the samples was the regular rectangular or square shapes. This multi‐component organic–inorganic nanomaterial was used to modify a platinum substrate and subsequently employed for the detection of carbamazepine, an anti‐convulsion drug. UV/Vis spectroscopy revealed that a strong hypochromism occurred over time, after mixing solutions of graphene–Au–Ag with carbamazepine. This can be attributed to π–π stacking between the aromatic groups of the two compounds. Linear sweep voltammetry (LCV) provided evidence that the modified platinum substrate presented a significant electrocatalytic reaction toward the oxidation of carbamazepine. The intensity of the current was found to increase by up to 2.5 times, and the oxidation potential shifted from +1.5 to +1.35 V(Ag/AgCl) in comparison with the unmodified electrode. Electrochemical impedance spectroscopy (EIS) was further used to thoroughly assess the activity of the platinum electrode that was modified by the deposition of the Gr‐Au‐Ag composites in the presence of various concentrations of carbamazepine. The experimental EIS records were used for the generation of an equivalent electrical circuit, based on the charge‐transfer resistance (Rct), Warburg impedance (ZD), solution resistance (Rs), and a constant phase element (CPE) that characterizes the non‐ideal interface capacitive responses.
Understanding the Role of Water in Aqueous Ruthenium‐Catalyzed Transfer Hydrogenation of Ketones.
Authors: Pavlova Anna , Meijer Evert Jan
Published: August 2012

We report an accurate computational study of the role of water in transfer hydrogenation of formaldehyde with a ruthenium‐based catalyst using a water‐specific model. Our results suggest that the reaction mechanism in aqueous solution is significantly different from that in the gas phase or in methanol solution. Previous theoretical studies have shown a concerted hydride and proton transfer in the gas phase (M. Yamakawa, H. Ito, R. Noyori, J. Am. Chem. Soc. 2000, 122, 1466–1478;J.‐W. Handgraaf, J. N. H. Reek, E. J. Meijer, Organometallics 2003, 22, 3150–3157; D. A. Alonso, P. Brandt, S. J. M. Nordin, P. G. Andersson, J. Am. Chem. Soc. 1999, 121, 9580–9588; D. G. I. Petra, J. N. H. Reek, J.‐W. Handgraaf, E. J. Meijer, P. Dierkes, P. C. J. Kamer, J. Brussee, H. E. Schoemaker, P. W. N. M. van Leeuwen, Chem. Eur. J. 2000, 6, 2818–2829), whereas a delayed, solvent‐mediated proton transfer has been observed in methanol solution (J.‐W. Handgraaf, E. J. Meijer, J. Am. Chem. Soc. 2007, 129, 3099–3103). In aqueous solution, a concerted transition state is observed, as in the previous studies. However, only the hydride is transferred at that point, whereas the proton is transferred later by a water molecule instead of the catalyst.
Phase Transition of a Cobalt‐Free Perovskite as a High‐Performance Cathode for Intermediate‐Temperature Solid Oxide Fuel Cells
Authors: Jiang Shanshan , Zhou Wei , Niu Yingjie , Zhu Zhonghua , Shao Zongping
Published: August 2012

It is generally recognized that the phase transition of a perovskite may be detrimental to the connection between cathode and electrolyte. Moreover, certain phase transitions may induce the formation of poor electronic and ionic conducting phase(s), thereby lowering the electrochemical performance of the cathode. Here, we present a study on the phase transition of a cobalt‐free perovskite (SrNb0.1Fe0.9O3−δ, SNF) and evaluate its effect on the electrochemical performance of the fuel cell. SNF exists as a primitive perovskite structure with space group P4mm (99) at room temperature. As evidenced by in situ high‐temperature X‐ray diffraction measurements over the temperature range of 600 to 1000 °C, SNF undergoes a transformation to a tetragonal structure with a space group I4/m (87). This phase transition is accompanied by a moderate change in the volume, allowing a good cathode/electrolyte interface on thermal cycling. According to the electrochemical impedance spectroscopy evaluation, the I4/m phase exhibits positive effects on the cathode’s performance, showing the highest oxygen reduction reaction activity of cobalt‐free cathodes reported so far. This activity improvement is attributed to enhanced oxygen surface processes.
Space vector pulse‐width modulation theory and solution for Z‐source inverters with maximum constant boost control
Authors: Yu Kun , Luo Fang Lin , Zhu Miao , Cai Xu
Published: August 2012

The theory of space vector pulse‐width modulation (SVPWM) technique for the three‐phase Z‐source inverter has been introduced in detail, and a novel implementation scheme based on the maximum constant boost control method is presented in this paper. Like the traditional carrier‐based maximum constant boost control strategy, the proposed control method is able to achieve the maximum voltage boost ability while always keeping the shoot‐through duty ratio constant. Besides, it inherits the advantages from the SVPWM technique. Compared with carrier‐based strategies, it has wider linear operation range and is easier for digital implementation. The number of switching transition in each switching cycle is reduced, which significantly decreases switching losses. To investigate the advantages of lessening switching losses, three optimal switching patterns are proposed and compared with the carrier‐based strategy. It is demonstrated that the number of switching transition can be reduced by 60% at most by the proposed SVPWM‐based control method. All the theoretical analysis has been validated by the simulation results in MATLAB/Simulink at last. Copyright © 2012 John Wiley & Sons, Ltd.
Production of fermented goat beverage using a mixed starter culture of lactic acid bacteria and yeasts
Authors: Agata Lasik , Jan Pikul
Published: August 2012

Cow milk and goat milk can be used to produce fermented milk drinks, which have different properties. To use goat milk as a raw material, the fermentation conditions have to be carefully adapted to receive an optimal product. The aim of this study was to find the most appropriate starter culture for producing a health‐promoting goat beverage. The improvement of the quality of fermented goat beverage was done by selection of specific microbial strains and to define a ratio between the compounds of the starter culture. Goat milk was inoculated with starter cultures each containing two specified bacterial strains (Lacococcus lactis and L. lactis subsp. cremoris or Sterptococcus thermophilus and Lactobacillus delbruckii subsp. bulgaricus) as well as yeasts (Saccharomyces fragilis) in three concentrations 0.2, 0.4 or 0.6 g dm−3. The bacteria and yeasts growth and their metabolic profile was done by monitoring of the impedance. The fermentation process was characterized by pH value, alcohol content, color, and texture changes. Sensory evaluation of the final product was also performed. It was found that the use of L. lactis, L. lactis subsp. cremoris, and S. fragilis at 0.2 or 0.4 g dm−3 gave the most satisfying results and can be successfully utilized in goat milk fermentation.
Biotic controls on shallow translational landslides
Authors: Vorpahl Peter , Dislich Claudia , Elsenbeer Helmut , Märker Michael , Schröder Boris
Published: August 2012

In undisturbed tropical montane rainforests massive organic layers accommodate the majority of roots and only a small fraction of roots penetrate the mineral soil. We investigated the contribution of vegetation to slope stability in such environments by modifying a standard model for slope stability to include an organic layer with distinct mechanical properties. The importance of individual model parameters was evaluated using detailed measurements of soil and vegetation properties to reproduce the observed depth of 11 shallow landslides in the Andes of southern Ecuador. By distinguishing mineral soil, organic layer and above‐ground biomass, it is shown that in this environment vegetation provides a destabilizing effect mainly due to its contribution to the mass of the organic layer (up to 973 t ha− 1under wet conditions). Sensitivity analysis shows that the destabilizing effect of the mass of soil and vegetation can only be effective on slopes steeper than 37.9°. This situation applies to 36% of the study area. Thus, on the steep slopes of this megadiverse ecosystem, the mass of the growing forest promotes landsliding, which in turn promotes a new cycle of succession. This feedback mechanism is worth consideration in further investigations of the impact of landslides on plant diversity in similar environments. Copyright © 2012 John Wiley & Sons, Ltd.
Regulation of microglia development and homeostasis
Authors: Greter Melanie , Merad Miriam
Published: August 2012

Microglia represent the resident macrophages of the central nervous system (CNS) and account for 10% of the adult glial cell population in the normal brain. Although microglial cells are thought to contribute to most pathological conditions including CNS infections, neuroinflammatory lesions, brain tumors, and neurodegenerative diseases, their exact role in CNS development, homeostasis, and disease remains poorly understood. In contrast to most macrophage populations, microglia survive high‐dose ionizing radiation and maintain themselves locally and independently of circulating precursors in the steady state. However, controversies remain on the origin of microglia in the brain and whether they could potentially be repopulated by circulating myeloid precursors after brain injury. Microglia‐targeted therapies through the use of genetically modified circulating hematopoietic cells proved to be a promising therapeutic strategy for the treatment of brain diseases. It is thus of great importance to understand the contribution and developmental cues of circulating myeloid cells as potential microglia progenitors to the adult pool of microglia in the steady state and under inflammatory conditions. © 2012 Wiley Periodicals, Inc.
Exploiting stem cell therapy: The 3rd meeting of stem cell research Italy
Authors: Di Bernardo Giovanni , Piva Roberta , Giordano Antonio , Galderisi Umberto
Published: August 2012

The study of stem cells is one of the most exciting areas of contemporary biomedical research. During the 3rd Joint Meeting of Stem Cell Research Italy (June 2012, Ferrara, Italy), scientists from different multidisciplinary areas explored new frontiers of basic and applied stem cell research with key lectures and oral presentations. There was a public debate on ethics during the opening ceremony, specifically on the limits and potentialities of adult and embryonic stem cells. Some scientists presented basic research data showing evolutionary aspects, which could be of interest in understanding specific biological phenomena. Others focused on “dangerous liaisons” between gene transfer vectors and the human genome. Some speakers provided insight into current stem cell therapies, such as those involving human epithelial stem cells for treatment of skin diseases. Other researchers presented data on close‐to‐therapy findings, such as the use of mesenchymal stem cells in brain repair. Of note, during the meeting, spotlights were focused on major issues that have to be considered for GMP stem cell production for cell therapy. In “Meet the Expert” sessions, specialists presented innovative technologies such as a next‐generation sequencing system. Finally, the meeting provided an excellent opportunity for young scientists to show their findings, and to discuss with each other and with internationally recognized experts. J. Cell. Physiol. 228: 911–914, 2013. © 2012 Wiley Periodicals, Inc.
Detecting and estimating density dependence in wildlife populations
Authors: Lebreton Jean‐Dominique , Gimenez Olivier
Published: August 2012

We review methods for detecting and assessing the strength of density dependence based on 2 types of approaches: surveys of population size and studies of life history traits, in particular demographic parameters. For the first type of studies, methods neglecting uncertainty in population size should definitely be abandoned. Bayesian approaches to simple state‐space models accounting for uncertainty in population size are recommended, with some caution because of numerical difficulties and risks of model misspecification. Realistic state‐space models incorporating features such as environmental covariates, age structure, etc., may lack power because of the shortness of the time series and the simultaneous presence of process and sampling variability. In all cases, complementing the population survey data with some external information, with priority on the intrinsic growth rate, is highly recommended. Methods for detecting density dependence in life history traits are generally conservative (i.e., tend to underestimate the strength of density dependence). Among approaches to correct for this effect, the state‐space formulation of capture–recapture models is again the most promising. Foreseeable developments will exploit integrated monitoring combining population size surveys and individual longitudinal data in refined state‐space models, for which a Bayesian approach is the most straightforward statistical treatment. One may thus expect an integration of various types of models that will make it possible to look at density dependence as a complex biological process interacting with other processes rather than in terms of a simple equation; modern statistical and modeling tools make such a synthesis within reach. © 2012 The Wildlife Society.
Small sample bias in dynamic occupancy models
Authors: Mckann Patrick C. , Gray Brian R. , Thogmartin Wayne E.
Published: August 2012

Occupancy models may be used to estimate the probability that a randomly selected site in an area of interest is occupied by a species (ψ), given imperfect detection (p). This method can be extended, given multiple survey periods, to permit the estimation of seasonal probabilities of ψ, colonization (γ), persistence (φ), and extinction (1 − φ) in season t. We evaluated the sampling properties of estimators of these parameters using simulated data across a range of the parameters, differing levels of sites and visits, with a published dynamic occupancy model (Royle and Kery 2007). Bias depended largely on p and the number of visits, but also on the number of sites, ψt, γ, and 1 − φ. To decrease bias in all parameters to near zero, our results suggest that the number of required visits will depend on p, such that the probability of detection at an occupied site is near 0.9, and the required number of sites will be near 60 for ψt estimation and 120 or greater for γ and 1 − φ estimation. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.
Effects of predator exclusion on nest and hatchling survival in the gopher tortoise
Authors: Smith Lora L. , Steen David A. , Conner L. Mike , Rutledge Jessica C.
Published: August 2012

Gopher tortoise (Gopherus polyphemus) populations are declining throughout the Southeast, and high levels of predation on nests and juveniles have been suggested as a potential contributor to this decline. Therefore, we documented gopher tortoise nest success and hatchling survival relative to mammalian predator control. We used 4, large (approx. 40‐ha) fenced, predator exclosures to exclude mid‐sized mammalian predators: bobcat (Lynx rufus), raccoon (Procyon lotor), Virginia opossum (Didelphis virginianus), fox (Urocyon cinereoargenteusandVulpes vulpes), coyote (Canis latrans), nine‐banded armadillo (Dasypus novemcinctus), and skunk (Mephitis mephitis); 4 unfenced plots served as controls. We monitored nests for survival through hatching and used radio‐telemetry to examine hatchling survival. We radio‐tracked 40 hatchlings for up to 329 days, but we were only able to track 8 individuals from a single nest at an unfenced plot because of high nest predation. Mean nest survival was greater at exclosures than at unfenced controls (F1, 2 = 45.80,P = 0.0001). Hatchling survival differed (χ2 = 5.839,P = 0.016) between unfenced plots (37.5%) and exclosures (74.4%), suggesting that mammals also were significant predators of hatchlings. The number of juvenile (<13 cm in diameter) and subadult tortoise burrows (13–21.9 cm) increased over a 6‐year period in exclosures, providing further support for an effect of excluding mammalian predators on nest and juvenile tortoise survival. © 2012 The Wildlife Society.
Hydrogel Substrate Stiffness and Topography Interact to Induce Contact Guidance in Cardiac Fibroblasts
Authors: Al‐Haque Shahed , Miklas Jason W. , Feric Nicole , Chiu Loraine L. Y. , Chen Wen Li Kelly , Simmons Craig A. , Radisic Milica
Published: August 2012

Previous studies demonstrated the importance of substrate stiffness and topography on the phenotype of many different cell types including fibroblasts. Yet the interaction of these two physical parameters remains insufficiently characterized, in particular for cardiac fibroblasts. Most studies focusing on contact guidance use rigid patterned substrates. It is not known how the ability of cardiac fibroblasts to follow grooves and ridges changes as the substrate stiffness is decreased to match the range of stiffness found in native heart tissues. This report demonstrates a significant interactive effect of substrate stiffness and topography on cardiac fibroblast elongation and orientation using polyacrylamide substrates of different stiffness and topography.

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Non‐Adhesive Behavior of New Nanostructured PNIPAM Surfaces Towards Specific Neurodegenerative Proteins: Application to Storage and Titration of Tau Proteins
Authors: Vrlinic Tjasa , Debarnot Dominique , Legeay Gilbert , Coudreuse Arnaud , El Moualij Benaissa , Zorzi Willy , Perret‐Liaudet Armand , Quadrio Isabelle , Mozetic Miran , Poncin‐Epaillard Fabienne
Published: August 2012

New nonfouling tubes are developed and their influence on the adhesion of neuroproteins is studied. The biomarkers are considered as single components (recombinant prion and Tau proteins) or in a solution of native and pathological forms. The samples are stored for 24 h at 4 °C in virgin and treated tubes layered with two different nanostructured coatings based on poly(N‐isopropylacrylamide) with either a positive or a neutral charge, and the protein adhesion is monitored. The recombinant protein with a high pI is repelled from the nanostructured surface that has a negative ζ potential, whereas the recombinant protein with the lower pI is attracted. Furthermore, in the case of complex solutions, neutral nanostructured surfaces are able to retain all amyloid biomarkers.

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Enhancing Specific Binding of L929 Fibroblasts: Effects of Multi‐Scale Topography of GRGDY Peptide Modified Surfaces
Authors: Zhou Feng , Li Dan , Wu Zhaoqiang , Song Bo , Yuan Lin , Chen Hong
Published: August 2012

Surface chemical composition and roughness caused by micro/nano‐topographical structures are two predominant factors in determining cellular response. A series of gold nanoparticle layers (GNPLs) with increasing surface roughness are prepared by depositing gold nanoparticles onto planar gold films. Glycine‐arginine‐glycine‐aspartic acid‐tyrosine (GRGDY) peptide is then conjugated to the surface through poly[oligo(ethylene glycol) methacrylate] polymer brushes as spacers. The pristine micro/nano‐roughness structures significantly inhibit L929 cell growth. After modification with POEGMA‐GRGDY, however, the micro/nano‐structures greatly enhance L929 cell‐specific interactions while maintaining superior low‐fouling ability compared to planar gold.

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Monomers for Adhesive Polymers, 9–Synthesis, Radical Photopolymerization, and Properties of (Meth)acrylamido Dihydrogen Phosphates
Authors: Moszner Norbert , Angermann Jörg , Fischer Urs , Bock Thorsten
Published: August 2012

5‐Methacrylamidopentyl (3a), 10‐(N‐methylacrylamido)decyl (3b), or 11‐(N‐methylacrylamido)undecyl dihydrogen phosphate (3c) are synthesized by (meth)acrylation of the corresponding ω‐aminoalkane‐1‐ols with methacrylic anhydrid or acryloyl chloride followed by phosphorylation of the formed ω‐(meth)acrylamidoalkane‐1‐ols. The monomers show a significantly improved hydrolytic stability compared to the corresponding methacrylate‐based dihydrogen phosphates. The photopolymerization of 3a–c with a bis(acrylamide) crosslinker confirms a high reactivity in the free‐radical copolymerization. These monomers enable the mediation of a strong bond between the enamel or dentin surface and a restorative composite under self‐etching conditions.

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The autophagy protein LC3A correlates with hypoxia and is a prognostic marker of patient survival in clear cell ovarian cancer
Authors: Spowart Jaeline E , Townsend Katelin N , Huwait Hassan , Eshragh Sima , West Nathan R , Ries Jenna N , Kalloger Steve , Anglesio Michael , Gorski Sharon M , Watson Peter H , Gilks C Blake , Huntsman David G , Lum Julian J
Published: August 2012

Clear cell ovarian cancer histotypes exhibit metabolic features associated with resistance to hypoxia and glucose deprivation‐induced cell death. This metabolic characteristic suggests that clear cell ovarian cancers activate survival mechanisms not typical of other epithelial ovarian cancers. Here we demonstrate that microtubule‐associated protein 1 light chain 3A (LC3A), a marker of autophagy, is related to hypoxia and poor prognosis in clear cell ovarian cancer. In 485 ovarian tumours, we found that LC3A was significantly associated with poor progression‐free (p = 0.0232), disease‐specific (p = 0.0011) and overall patient survival (p = 0.0013) in clear cell ovarian cancer patients, but not in other subtypes examined. LC3A was an independent prognostic marker of reduced disease‐specific [hazard ratio (HR): 2.55 (95% CI 1.21–5.37); p = 0.014] and overall survival [HR: 1.95 (95% CI 1.00–3.77); p = 0.049] in patients with clear cell ovarian carcinoma. We also found a strong link between autophagy and hypoxia as LC3A staining revealed a significant positive association with the hypoxia‐related proteins carbonic anhydrase‐IX and HIF‐1α. The functional link between hypoxia and autophagy was demonstrated using clear cell and high‐grade serous cell lines that were subjected to hypoxia or hypoxia + glucose deprivation. Clear cell carcinoma lines displayed greater autophagy induction and were subsequently more sensitive to inhibition of autophagy under hypoxia compared to the high‐grade serous lines. Together, our findings indicate that hypoxia‐induced autophagy may be crucial to the clinical pathology of clear cell ovarian cancer and is a potential explanation for histological subtype differences in patient disease progression and outcomes. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Effect of window layer composition in Cd1−xZnxS/CdTe solar cells
Authors: Kartopu Giray , Clayton Andrew J. , Brooks William S.M. , Hodgson Simon D. , Barrioz Vincent , Maertens Alban , Lamb Dan A. , Irvine Stuart J.C.
Published: August 2012

To improve CdS/CdTe cell/module efficiencies, CdS window layer thinning is commonly applied despite the risk of increased pin‐hole defects and shunting. An alternative approach is to widen the band gap of the window layer (2.42 eV for CdS) via alloying, for example, by forming compositions of Cd1−xZnxS. In this study, the performance of Cd1−xZnxS/CdTe thin‐film solar cells has been studied as a function of x (from x = 0 to 0.9), widening the window layer band gap up to and over 3.4 eV. Optimum Cd1−xZnxS compositions were clearly identified to be around x = 0.7, and limitations to the achievable photocurrent and conversion efficiencies have been addressed. Copyright © 2012 John Wiley & Sons, Ltd.
Structural analyses of seeded thin film microcrystalline silicon solar cell
Authors: Agbo S. N. , Dobrovolskiy S. , Wegh G. , van Swaaij R. A. C. M. M. , Tichelaar F. D. , Sutta P. , Zeman M.
Published: August 2012

This contribution investigates the effect of seeding the growth of thin film microcrystalline silicon (µc‐Si : H) deposited by radio frequency plasma‐enhanced chemical vapor deposition on the material properties of µc‐Si : H film and the device performance of p‐i‐n and n‐i‐p µc‐Si : H solar cells. By means of Raman measurement, x‐ray diffraction (XRD) and transmission electron microscopy (TEM), we investigate the structure of seeded µc‐Si : H. In particular, the effect of seed layers on the crystallinity development is investigated. Measurements of the depth profile of the crystalline mass fraction using Raman spectroscopy show that seed layers lead to a more rapid and uniform crystallinity development in growth direction. The amorphous incubation layer is suppressed and crystallization begins directly from onset of film growth without evolving through the intermediate growth phases. From TEM analyses, we observe that crystal sizes are not affected by seed layers. Horizontal cracks are however observed to dominate the early growth of µc‐Si : H in p‐i‐n solar cell and this is reduced upon seeding. For the n‐i‐p cells, these cracks are not affected by seeding. XRD results also indicate that the use of seed layers does not affect the crystal sizes but affects the direction of preferential orientation. Solar cell external parameters show that seeding of p‐i‐n solar cells leads mainly to increase in short‐circuit current density, Jsc with a slight drop in open‐circuit voltage, Voc. For the n‐i‐p cells, a reverse effect is observed. In this case, the Voc increases and the Jsc decreases. Copyright © 2012 John Wiley & Sons, Ltd.
Histopathologic features of atypical glands on prostate biopsy: Nucleolar size is a predictor of subsequent detection of prostatic adenocarcinoma
Authors: Venigalla Sriram , Zhao Chen , Miyamoto Hiroshi
Published: August 2012

BACKGROUND

Patients whose prostate biopsy reveals the presence of atypical glands suspicious for carcinoma (AGSC) are subject to close monitoring and repeat biopsies, perhaps unnecessarily, as clinicians do not have a clear basis for understanding and stratifying the significance of these findings.

METHODS

In a retrospective, blinded manner, we histopathologically examined initial biopsies reported as AGSC (82 patients, 93 foci). On subsequent biopsies, 31 (38%)/5 (6%) patients were found to have prostate cancer (PCA)/AGSC, respectively, while no carcinoma (NOCA) was identified in the remainder (56%) of cases.

RESULTS

Nucleolar grade (on a scale of 1–4 with “1” denoting small, inconspicuous nucleoli and “4” denoting macronucleoli) was significantly higher in PCA cases than in NOCA cases whether comparing all AGSC foci (P = 0.006) or when considering the highest grade in each patient (P = 0.009). However, the number of AGSC per focus was similar (P = 0.926) between PCA (mean ± SD: 7.03 ± 5.35) and NOCA (mean ± SD: 7.13 ± 4.44). Adjacent (P = 0.117) and separate (P = 0.457) high‐grade prostatic intraepithelial neoplasia was found in 8/37 (22%) foci and 12/31 (39%) cases in PCA, respectively, and in 4/48 (8%) foci and 13/46 (28%) cases in NOCA, respectively. The presence of intraluminal dense secretion, crystalloid, or mucin in AGSC did not show a statistically significant correlation between PCA [5/37 (14%)] and NOCA [10/48 (21%)] (P = 0.567).

CONCLUSIONS

Our study may thus clarify the significance of AGSC on prostate biopsy and suggests that the size of nucleoli in AGSC is a positive predictor of subsequent detection of prostatic adenocarcinoma. Prostate 73: 376–381, 2013. © 2012 Wiley Periodicals, Inc.
Analysis of an optical biosensor based on elastic light scattering from diamond‐, glass‐, and sapphire microspheres
Authors: Murib Mohammed S. , Tran Anh Quang , De Ceuninck Ward , Schöning Michael J. , Nesládek Milos , Serpengüzel Ali , Wagner Patrick
Published: August 2012

Deoxyribonucleic acid (DNA) and protein recognition are now standard tools in biology. In addition, the special optical properties of microsphere resonators expressed by the high quality factor (Q‐factor) of whispering gallery modes (WGMs) or morphology dependent resonances (MDRs) have attracted the attention of the biophotonic community. Microsphere‐based biosensors are considered as powerful candidates to achieve label‐free recognition of single molecules due to the high sensitivity of their WGMs. When the microsphere surface is modified with biomolecules, the effective refractive index and the effective size of the microsphere change resulting in a resonant wavelength shift. The transverse electric (TE) and the transverse magnetic (TM) elastic light scattering intensity of electromagnetic waves at 600 and 1400 nm are numerically calculated for DNA and unspecific binding of proteins to the microsphere surface. The effect of changing the optical properties was studied for diamond (refractive index 2.34), glass (refractive index 1.50), and sapphire (refractive index 1.75) microspheres with a 50 µm radius. The mode spacing, the linewidth of WGMs, and the shift of resonant wavelength due to the change in radius and refractive index, were analyzed by numerical simulations. Preliminary results of unspecific binding of biomolecules are presented. The calculated shift in WGMs can be used for biomolecules detection.
Luminescence properties of stoichiometric EuM2S4 (M = Ga, Al) conversion phosphors for white LED applications
Authors: Yu Ruijin , Yang Hyun Kyoung , Moon Byung Kee , Choi Byung Chun , Jeong Jung Hyun
Published: August 2012

EuM2S4 (M = Ga, Al) phosphors were synthesized using the solid‐state reaction method. The structure and photoluminescence (PL) properties of the phosphors were investigated in detail. XRD pattern results indicated that the two phosphors are isostructures to the orthorhombic structure. The PL spectra showed that the EuGa2S4 and EuAl2S4 phosphors can be excited efficiently by UV–visible light from 350 to 480 nm and that they emit intense green and bluish‐green light, with emission bands peaking at 545 and 506 nm, respectively. The fluorescence lifetimes of Eu2+ were calculated to be 0.076 and 0.064 µs for EuGa2S4 and EuAl2S4, respectively. The thermal quenching temperature was 412 K for EuGa2S4. A green LED was fabricated by the combination of a near‐UV InGaN chip and the prepared EuGa2S4 phosphor. The EuGa2S4 phosphor exhibits much better green color purity than EuAl2S4. As a result, EuGa2S4 might be a promising green phosphor candidate for solid‐state lighting LED technology.
Erratum: Evaluation of the bond polarizabilities of zincblende‐type semiconductors: Application to the Raman spectra of disordered GaSb/AlSb (001) superlattices [Phys. Status Solidi B 249, No. 8, 1521–1530 (2012)]
Authors: Berdekas D. , Ves S.
Published: August 2012

Equations with reference to the zinc blende primitive cell volume are slightly changed.
Photoluminescence properties of carbon‐doped β‐FeSi2 nanocrystals
Authors: Maeda Yoshihito , Nishimura Kentaro , Nakajima Takahito , Matsukura Bui , Narumi Kazumasa , Sakai Seiji
Published: August 2012

We report enhancement of intrinsic photoluminescence (PL) from β‐FeSi2 nanocrystals by doping carbon. In the appropriate dose of C60+ ion implantation into the average nanocrystal size of 14 nm, the PL intensity was enhanced by 260% and increase of the exciton binding energy of 1.8 meV in comparison with that of the non‐doped nanocrystal. Furthermore, we found that there was a clear correlation between the PL enhancement and increase of the exciton binding energy. This important result suggests that carbon atoms doped in the silicide lattice may play as an isoelectronic trap and probably form bound excitons with stable states as predicted theoretically. We found a new mechanism of the PL enhancement for β‐FeSi2 nanocrystals. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electrical activity of multivacancy defects in silicon
Authors: Santos P. , Coutinho J. , Rayson M. J. , Briddon P. R.
Published: August 2012

The formation processes and properties of multivacancy defects in Si have been recently the subject of several re‐search studies. Here we report on density functional calculations concerning the stability and electrical activity of the tetravacancy, pentavacancy and hexavacancy complexes in Si. Formation energy calculations indicate that Four‐Fold Coordinated (FFC) V4 and V5 are more stable than Part‐of‐Hexagonal‐Ring (PHR) or planar structures by at least 1.2 eV and 0.6 eV, respectively. This relative stability order between configurations remains unchanged for different charged states from double plus to double minus. Calculations of the electrical activity predict deep acceptor levels for the FFC defects. Accordingly, electron traps related to (–/0) and (=/–) levels near Ec – 0.5 eV were found for V4 and V5, whereas levels for V6 were estimated at Ec – 0.35 eV. No donor levels were found for these defects. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Scattering tensors and optical transitions in Si and Ge
Authors: Kunert H. W. , Machatine A. G. J. , Niyongabo P. , Govender M. , Mwakikunga B. W.
Published: August 2012

The selection rules (SR's) for the Kronecker product (KP) of Si and Ge irreducible representations (irreps) are required to determine the intervalley scattering processes. The SR's for transitions between the lowest conduction band minima at Γ, X and L high symmetry points and the highest maximum of the valence band (VB) in the Brillouin zone of O7h space group symmetry are determined. The symmetry of phonons due to electron‐phonon (El‐Ph) interaction follows from the KP's: L1 ⊗ Γ12(Γ2–), Δ1 Γ12(Γ2–), L1(L1+) ⊗ Δ1 for Ge and L1 ⊗ Γ15(Γ4–), Δ ⊗ Γ15(Γ4–), L1(L1+) ⊗ Δ1 for Si. The elements of El‐Ph scattering tensors are linear combinations of the Clebsch‐Gordon coefficients (CGC's). Here we have computed the coupling coefficients relevant to scattering tensors. Our theoretical results confirm the available experimental data. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Enhancement of IR light emission from β‐FeSi2 nanocrystals embedded in Si
Authors: Maeda Yoshihito , Nishimura Kentaro , Nakajima Takahito , Matsukura Bui , Narumi Kazumasa , Sakai Seiji
Published: August 2012

We have systematically investigated photoluminescence (PL) properties of β‐phase nanocrystals which are formed by a phase transition from metastable γ‐FeSi2 with a Fluorite structure to β‐FeSi2, and succeeded in enhancement of the PL intensity in the optimum conditions of double annealing process. For the PL enhancement, the time of postannealing at 800 °C is dominated by the time of the preannealing at 400 or 500 °C which is related to amount of the γ‐phase. After discussing some possible factors, we speculate that the PL enhancement observed in this study may be attributed mainly to improvement of the interface condition between the nanocrystal and Si, because the crystallographic epitaxial relationship among the phases, Si(111)//γ(111)//β(202)/(220) can be maintained during precipitation of the nanocrystal on Si(111). (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)