bluuebunny/crossref_metadata_2025 huggingface dataset:
pERK 1/2 inhibit Caspase‐8 induced apoptosis in cancer cells by phosphorylating it in a cell cycle specific manner
Authors: Mandal Ranadip , Raab Monika , Matthess Yves , Becker Sven , Knecht Rainald , Strebhardt Klaus
Published: November 2013

ERK 1/2 are found to be hyperactive in many cancers. Active ERK 1/2 (pERK 1/2) are known to protect cancer cells from undergoing death receptor‐mediated apoptosis, although the mechanism(s) behind this is poorly understood. Through in vitro kinase assays and mass‐spectrometry we demonstrate that pERK 1/2 can phosphorylate pro‐Caspase‐8 at S387. Also, in EGFR‐overexpressing Type I and II ovarian and breast cancer cell lines respectively, ERK 1/2 remain active only during the interphase. During this period, pERK 1/2 could inhibit Trail‐induced apoptosis, most effectively during the G1/S phase. By knocking‐down the endogenous pro‐Caspase‐8 using RNAi and replacing it with its non‐phosphorylatable counterpart (S387A), a significant increase in Caspase‐8 activity upon Trail stimulation was observed, even in the presence of pERK 1/2. Taken together, we propose that a combination of Trail and an inhibitor of ERK 1/2 activities could potentially enhance of Trail's effectiveness as an anti‐cancer agent in ERK 1/2 hyperactive cancer cells.
Use of Ultrasonography to Locate Laryngeal Structures for Laryngeal Electromyography
Authors: Seo Han Gil , Jang Hye Jin , Oh Byung‐Mo , Kim Won , Han Tai Ryoon
Published: November 2013

Objective

To measure the representative anatomic landmarks for laryngeal electromyography (LEMG) and to delineate an accurate ultrasonography‐guided approach.

Design

A retrospective study.

Setting

A university hospital.

Participants

A total of 518 patients (270 men and 248 women) who underwent LEMG.

Methods

The medical records, LEMG records, and ultrasonographic measurements of the patients who underwent LEMG in our electromyography laboratory between March 2010 and January 2013 were reviewed.

Main Outcome Measurement

The longest dimension of the cricothyroid membrane, the height of the arch of the cricoid cartilage, and the distance from the superior border of the cricoid cartilage to the midpoint of the vocal fold were measured by using ultrasonography.

Results

A total of 585 studies in 518 patients with a standard deviation (SD) mean age of 56.01 ± 14.36 years (men, 59.28 ± 14.09 years; women, 52.45 ± 13.81 years) were reviewed. The most common etiology was surgery (44.6%), and the left side (56%) of the vocal folds was more frequently involved than the right side (23.4%) or both sides (9.4%). The longest dimension of the cricothyroid membrane, height of the arch of the cricoid cartilage, and distance from the superior border of the cricoid cartilage to the midpoint of the vocal fold measured 1.06 ± 0.33 cm (men, 1.16 ± 0.34 cm; women, 0.97 ± 0.29 cm), 0.83 ± 0.24 cm (men, 0.88 ± 0.24 cm; women, 0.77 ± 23 cm), and 1.88 ± 0.48 cm (men, 2.09 ± 0.51 cm; women, 1.70 ± 0.36 cm), respectively. All measurements differed significantly between the men and women (P < .001 by Student t test).

Conclusions

The current study provides reference ranges for ultrasonographic measurements of important anatomic landmarks for LEMG. This study also provides a technique for using ultrasonography in LEMG. Ultrasonography may be used as an adjuvant to overcome certain technical pitfalls of LEMG.
Garnet-pyroxene and lawsonite-bearing rocks of the Maksyutov Complex (Southern Urals)
Authors: Valizer P.M. , Rusin A.I. , Krasnobaev A.A. , Likhanov I.I.
Published: November 2013

The new petrological and geochrological data are used to constrain the nature of garnet-clinopyroxene and lawsonite-bearing rocks, which contain a rare variety of Fe-Ca-rich garnets. These rocks associated with antigorite serpentinites have no equivalents in the other units of the Maksyutov eclogite-glaucophane schist complex and, thus, can be regarded as a separate “mafic-ultramafic” unit. Based on their mineral and chemical composition, the garnet-clinopyroxene and lawsonite-bearing rocks can be interpreted as HP associations formed within a deep continental rifting setting. They experienced a series of metasomatic alterations during decompression exhumation and were accreted to the Maksyutov Complex as a result of the arc-continent collision. The U–Pb zircon data indicate that a Late Riphean–Lower Paleozoic age (824 and 440–470 Ma) was a crystallization age of garnet-clinopyroxene rocks and Ar–Ar white mica age (341 ± 2 Ma) represents the timing of the final accretion of all structural unit to the Maksyutov Complex.
Numerical modeling and inversion of electromagnetic logs in the wells drilled with biopolymer and oil-based mud
Authors: Glinskikh V.N. , Nikitenko M.N. , Epov M.I.
Published: November 2013

Algorithms and software for numerical modeling and inversion of electromagnetic logs in the wells drilled with biopolymer and oil-based mud are developed. The algorithms are based on linearized solutions of the forward and inverse problems of electromagnetic logging and permit fast modeling of induction logs and efficient recovery of electric conductivity around the well. Mathematical modeling is based on numerical-analytical solution of the 2D forward problem taking into account high conductivity contrast between the well and the formation. Linear inversion is based on SVD-decomposition of information matrix. The results of numerical modeling and inversion of synthetic and field logs at the intervals of fluid-saturated terrigenous and carbonate formations drilled using biopolymer and oil-based mud are given.
Reliability and responsiveness of the Norwegian version of the Neck Disability Index
Authors: Johansen Jan Borre , Roe Cecilie , Bakke Eva , Mengshoel Anne Marit , Andelic Nada
Published: November 2013

Background and aim

The Norwegian version of the Neck Disability Index (NDI) has been widely used in previous studies. To our knowledge, the test–retest reliability and responsiveness of the NDI have not been investigated. Thus, the aim of the present study was to investigate the test–retest reliability and responsiveness of the Norwegian version of the NDI in neck pain patients seen in a specialized outpatient clinic.

Methods

This study included patients referred to the neck and back outpatient clinic at Oslo University Hospital. A total of 255 patients were included in the study, of which 42 participated in the test–retest portion of the study. The intraclass correlation coefficient (ICC) was used to assess test-retest reliability. A total of 113 patients participated in the responsiveness analyses. Based on their responses on the Global Rating Scale of Change (GRS), patients were categorized into the following groups: worsened (n = 24), unchanged (n = 7) and improved (n = 62). The minimal detectable change (MDC) for the NDI was calculated. Responsiveness was assessed by constructing a Receiver Operating Characteristic curve (ROC curve) to distinguish patients who had improved or worsened from those who remained unchanged. The minimum clinically important difference (MCID) was estimated.

Results

The test–retest reliability between the baseline scores and the retest NDI scores was very good (ICC = 0.84; 95% CI 0.72–0.91). The ability of the NDI to discriminate between improved and unchanged patients (responsiveness) over time was acceptable based on the ROC curve analysis (AUC = 0.70; 95% CI 0.58–0.82). The estimated MDC for the Norwegian version of the NDI is 12.3%, and the MCID is 16.6%.

Conclusion

The Norwegian version of the NDI proved to be an instrument with good test–retest reliability and acceptable responsiveness for assessing neck pain-related disability among neck pain patients in a specialized outpatient clinic
10Be exposure dating of river terraces at the southern mountain front of the Dzungarian Alatau (SE Kazakhstan) reveals rate of thrust faulting over the past ~ 400 ka
Authors: Cording Anja , Hetzel Ralf , Kober Martin , Kley Jonas
Published: November 2013

The mountain belts of the Dzungarian Alatau (SE Kazakhstan) and the Tien Shan are part of the actively deforming India–Asia collision zone but how the strain is partitioned on individual faults remains poorly known. Here we use terrace mapping, topographic profiling, and 10Be exposure dating to constrain the slip rate of the 160-km-long Usek thrust fault, which defines the southern front of the Dzungarian Alatau. In the eastern part of the fault, where the Usek River has formed five terraces (T1–T5), the Usek thrust fault has vertically displaced terrace T4 by 132 ± 10 m. At two sites on T4, exposure dating of boulders, amalgamated quartz pebbles, and sand from a depth profile yielded 10Be ages of 366 ± 60 ka and 360 + 77/− 48 ka (both calculated for an erosion rate of 0.5 mm/ka). Combined with the vertical offset and a 45–70° dip of the Usek fault, these age constraints result in vertical and horizontal slip rates of ~ 0.4 and ~ 0.25 mm/a, respectively. These rates are below the current resolution of GPS measurements and highlight the importance of determining slip rates for individual faults by dating deformed landforms to resolve the pattern of strain distribution across intracontinental mountain belts.
The BBC Voices website
Authors: Herring J. R.
Published: November 2013

The BBC Voices website will probably already be familiar to those involved in English Language teaching and research. Along with local and national radio programmes about English that were broadcast in the UK in 2005, this site is one of the outputs of Voices, a large collaborative multi-platform project undertaken by the BBC and the University of Leeds in 2004 and 2005. Members of the public were asked to submit to the site the different words they use for a range of concepts, and to air their views on English and language use around the UK. In parallel, regional radio journalists who had been trained by Leeds linguists conducted over 300 sociolinguistic interviews with small groups of speakers, discussing the same set of concepts as the online questionnaire, and similarly eliciting opinions on English and language use.
Studying attitudes to English usage
Authors: van Ostade Ingrid Tieken-Boon
Published: November 2013

Attitudes to English Usageis the title of a book published in 1970 by W. H. Mittins, Mary Salu, Mary Edminson and Sheila Coyne from the University of Newcastle upon Tyne that reported on an enquiry held among some 450 informants concerning the acceptability of 55 usage items. These items had been selected because they were at the time ‘subject to variation in practice and dispute in theory’ (Mittins et al., 1970: 4), and they include sentences likeHe refused to even think about it,It looked like it will rainandEveryone has their off-days. In each case the offensive feature had been highlighted so that informants would know what they had to comment on:to even think(a split infinitive), the use oflikeforas if, and oftheirwith a singular antecedent (everyone). For fifty sentences the informants had to indicate acceptability in informal speech, informal writing, formal speech and formal writing, and for the remaining five only for informal and formal writing, since usage of these items was believed to be restricted to writing (1970: 4). The sentences were subsequently ranged from highest general acceptability (did not doaswell as) to lowest (veryunique), and correlations were calculated with the occupation of the informants (students, teachers, lecturers, examiners and non-educationists), while the items were also classified as colloquial (pretty reliable), etymological (data is), grammatical (did it quicker) and lexical/semantic (inferred/implied), or as language myths, ‘where the censorious tend to invoke a prescription of dubious authority’ (dangling participles) (1970: 15). The main part of the book dealt with the individual constructions, analysing the reasons for their status as debated usage items and providing further historical context in the process.
The role of L1 explicit metalinguistic knowledge in L3 oral production at the initial state
Authors: FALK YLVA , LINDQVIST CHRISTINA , BARDEL CAMILLA
Published: November 2013

In this study we explore the role of explicit metalinguistic knowledge (MLK) of first language (L1) in the learning of a third language (L3). We compare the oral production of 40 participants with varying degrees of explicit MLK of the L1, who are exposed to a completely new L3. In accordance with the second language (L2) status factor, which is further motivated by the distinction between implicit competence and explicit knowledge (Bardel & Falk, 2012; Paradis, 2009), we hypothesize that the participants with low explicit MLK in their L1 will transfer from their L2, and that the participants with high explicit MLK in the L1 will transfer from their L1. The structure of interest is adjective placement, which is the same in the L1 and the L3 (but not in the participants’ L2s). The results show that the degree of explicit MLK in the L1 plays a decisive role at the initial state of L3 learning.
ON THE EXISTENCE OF CHAOTIC BEHAVIOUR IN PURE AND SIMPLE MICROBIAL COMPETITION: THE ROLE OF CONTOIS KINETICS
Authors: ASIF MOHAMMAD , ALI EMAD , AJBAR ABDELHAMID
Published: November 2013

Microbial competition for nutrients is a common phenomenon that occurs between species inhabiting the same environment. Bioreactors are often used for the study of microbial competition since the number and type of microbial species can be controlled, and the system can be isolated from other interactions that may occur between the competing species. A common type of competition is the so-called “pure and simple” competition, where the microbial populations interact in no other way except the competition for a single rate-limiting nutrient that affects their growth rates. The issue of whether pure and simple competition under time-invariant conditions can give rise to chaotic behaviour has been unresolved for decades. The third author recently showed, for the first time, that chaos can theoretically occur in these systems by analysing the dynamics of a model where both competing species grow following the biomass-dependent Contois model while the yield coefficients associated with the two species are substrate-dependent. In this paper we show that chaotic behaviour can occur in a much simpler model of pure and simple competition. We examine the case where only one species grows following the Contois model with variable yield coefficient while the other species is allowed to grow following the simple Monod model with constant yield. We show that while the static behaviour of the proposed model is quite simple, the dynamic behaviour is complex and involves period doubling culminating in chaos. The proposed model could serve as a basis to re-examine the importance of Contois kinetics in predicting complex behaviour in microbial competition.
Assembly of co-bimb-polyoxotungstate hybrids: from 1D chain to 3D framework influenced by the charge of Keggin anions
Authors: Yu Tingting , Wang Kun , Ma Huiyuan , Pang Haijun , Li Shaobin
Published: November 2013

Two new compounds with bifunctional electrocatalytic activities have been obtained, which shows that the charge of the Keggin anions is a key factor to control the dimension of the hybrid compounds.
One-pot synthesis of 1-arylmethyl-4-[(E)-alk-1-enyl]-1H-1,2,3-triazoles via a cross-coupling/click reaction sequence
Authors: Hoshi Masayuki , Okimoto Mitsuhiro , Oikawa Asuka , Miyawaki Shunsuke , Shimotori Yasutaka
Published: November 2013

1-Arylmethyl-4-[(E)-alk-1-enyl]-1H-1,2,3-triazoles have been synthesized from terminal conjugated (E)-enynes, prepared by copper-mediated cross-coupling reaction of (E)-alk-1-enyldisiamylboranes with (trimethylsilyl)ethynyl bromide, benzyl bromides and sodium azide in a one-pot fashion.
Electronic and molecular structures of the active-site H-cluster in [FeFe]-hydrogenase determined by site-selective X-ray spectroscopy and quantum chemical calculations
Authors: Lambertz Camilla , Chernev Petko , Klingan Katharina , Leidel Nils , Sigfridsson Kajsa G. V. , Happe Thomas , Haumann Michael
Published: November 2013

Site-selective X-ray spectroscopy discriminated the cubane and diiron units in the H-cluster of [FeFe]-hydrogenase revealing its electronic and structural configurations.
Characterization of multi-dye pressure-sensitive microbeads
Authors: Lacroix Daniel , Viraye-Chevalier Teddy , Seiter Guillaume , Howard Jonathan , Dabiri Dana , Khalil Gamal E. , Xia Younan , Zhu Cun
Published: November 2013

The response times of pressure-sensitive particles to passing shockwaves were measured to investigate their ability to accurately determine pressure changes in unsteady flows. The particles tested were loaded with novel pressure-sensitive dyes such as Pt (II) meso-tetra(pentafluorophenyl)porphine, Pt(II) octaethylporphine, bis(3,5-difluoro-2-(2-pyridyl)phenyl-(2-carboxypyridyl))iridium III, and iridium(III) bis(4-phenylthieno[3,2-c] pyridinato-N,C2’)acetylacetonate. For this work, porous silicon dioxide pressure-sensitive beads (PSBeads) were used. Two synthetic procedures were used to fabricate the particles. In the first, a one-step method loaded dyes during the synthesis of microbeads, in the second a two-step method synthesized the microbeads first, then loaded the dyes. The shock tube facility was used to measure the response times of microbeads to fast pressure jumps. The study involved testing multiple luminophors loaded in microbeads with various size distributions. Response times for the silica-based microbeads ranged between 26 μs and 462 μs (at 90% of the amplitude response), which are much faster than previously reported polystyrene-based microbead response times, which range from 507 μs to 1582 μs (at 90% of the amplitude response) [F. Kimura, M. Rodriguez, J. McCann, B. Carlson, D. Dabiri, G. Khalil, J. B. Callis, Y. Xia, and M. Gouterman, “Development and characterization of fast responding pressure sensitive microspheres,” Rev. Sci. Instrum. 79, 074102 (2008)].
A hybrid perturbed-chain SAFT density functional theory for representing fluid behavior in nanopores: Mixtures
Authors: Shen Gulou , Ji Xiaoyan , Öberg Sven , Lu Xiaohua
Published: November 2013

The perturbed-chain statistical associating fluid theory (PC-SAFT) density functional theory developed in our previous work was extended to the description of inhomogeneous confined behavior in nanopores for mixtures. In the developed model, the modified fundamental measure theory and the weighted density approximation were used to represent the hard-sphere and dispersion free energy functionals, respectively, and the chain free energy functional from interfacial statistical associating fluid theory was used to account for the chain connectivity. The developed model was verified by comparing the model prediction with molecular simulation results, and the agreement reveals the reliability of the proposed model in representing the confined behaviors of chain mixtures in nanopores. The developed model was further used to predict the adsorption of methane-carbon dioxide mixtures on activated carbons, in which the parameters of methane and carbon dioxide were taken from the bulk PC-SAFT and those for solid surface were determined from the fitting to the pure-gas adsorption isotherms measured experimentally. The comparison of the model prediction with the available experimental data of mixed-gas adsorption isotherms shows that the model can reliably reproduce the confined behaviors of physically existing mixtures in nanopores.
An exactly solvable three-dimensional nonlinear quantum oscillator
Authors: Schulze-Halberg A. , Morris J. R.
Published: November 2013

Exact analytical, closed-form solutions, expressed in terms of special functions, are presented for the case of a three-dimensional nonlinear quantum oscillator with a position dependent mass. This system is the generalization of the corresponding one-dimensional system, which has been the focus of recent attention. In contrast to other approaches, we are able to obtain solutions in terms of special functions, without a reliance upon a Rodrigues-type of formula. The wave functions of the quantum oscillator have the familiar spherical harmonic solutions for the angular part. For the s-states of the system, the radial equation accepts solutions that have been recently found for the one-dimensional nonlinear quantum oscillator, given in terms of associated Legendre functions, along with a constant shift in the energy eigenvalues. Radial solutions are obtained for all angular momentum states, along with the complete energy spectrum of the bound states.
Electronic structure and UV spectrum of hexachloroplatinate dianions in vacuo
Authors: Kaufman Sydney H. , Weber J. Mathias , Pernpointner Markus
Published: November 2013

We present a joint experimental and theoretical study of the electronic spectrum of hexachloroplatinate dianion. We have measured electronic photodissociation and photodetachment spectra of mass-selected PtCl62− ions in vacuo and compare these with calculated band positions from time-dependent density functional theory and from relativistic calculations. Excitation of an electronic transition of the dianion leads to resonant enhancement of the photodetachment cross section superimposed on direct detachment. Photoexcitation results in loss of Cl− and Cl0, depending on photon energy. The photofragmentation spectrum for formation of the PtCl4− fragment ion mirrors the UV/vis absorption spectrum of PtCl62− in solution with a small solvatochromic shift.
Effect of nanostructuring on the band structure and the galvanomagnetic properties in Bi1−xSbx alloys
Authors: Will C. H. , Elm M. T. , Klar P. J. , Landschreiber B. , Güneş E. , Schlecht S.
Published: November 2013

Magnetotransport measurements were performed on a series of nanostructured Bi1−xSbx alloy samples with an Sb content in the range between 0% and 60%. The samples were prepared by cold pressing and annealing of crystalline Bi1−xSbx nanoparticles, which were synthesized by mechanical alloying. The incorporation of Sb changes the band structure of these nanotextured alloys as well as their transport behavior. With increasing Sb content the band gap increases and reaches a maximum band gap of 42 meV at an Sb concentration of about 14% determined from temperature dependent resistivity measurements. For even higher Sb content, the band gap decreases again. The bands and thus the band gaps are shifted with respect to bulk material due to quantum confinement effects in the nanostructures. The change of the band structure with varying Sb content strongly affects the magnetoresistance behavior as well as the magnetic field dependence of the Hall-coefficient. Using a three band model in order to describe both properties, it was possible to determine the main band parameters of the nanostructured material as a function of the Sb content.
Room temperature compressibility and diffusivity of liquid water from first principles
Authors: Corsetti Fabiano , Artacho Emilio , Soler José M. , Alexandre S. S. , Fernández-Serra M.-V.
Published: November 2013

The isothermal compressibility of water is essential to understand its anomalous properties. We compute it by ab initio molecular dynamics simulations of 200 molecules at five densities, using two different van der Waals density functionals. While both functionals predict compressibilities within ∼30% of experiment, only one of them accurately reproduces, within the uncertainty of the simulation, the density dependence of the self-diffusion coefficient in the anomalous region. The discrepancies between the two functionals are explained in terms of the low- and high-density structures of the liquid.
Integral equation method for evaluation of eddy-current impedance of a tilted, surface-breaking crack
Authors: Larsson Lars , Boström Anders , Bövik Peter , Wirdelius Håkan
Published: November 2013

An integral equation method for solving the eddy-current nondestructive evaluation problem for a flat, tilted, and surface-breaking crack in a conducting half-space is presented. The method involves use of a half-space Green's tensor and the Bowler potential. This potential describes the jump in the electric field over the crack and is expanded in basis functions related to the Chebyshev polynomials, being a more analytical approach than the commonly used boundary element method. In the method, the scatterer defines a transformation operator to be applied on the incoming field. This is practical in simulations of the eddy-current inspection where this operator is independent of the position of the probe. The numerical calculations of the change in impedance due to the crack are compared to a Finite Element model of the problem and good agreement is found.
Small-signal modulation and differential gain of red-emitting (λ = 630 nm) InGaN/GaN quantum dot lasers
Authors: Frost Thomas , Banerjee Animesh , Bhattacharya Pallab
Published: November 2013

We report small-signal modulation bandwidth and differential gain measurements of a ridge waveguide In0.4Ga0.6N/GaN quantum dot laser grown by molecular beam epitaxy. The laser peak emission is at λ = 630 nm. The −3 dB bandwidth of an 800 μm long device was measured to be 2.4 GHz at 250 mA under pulsed biasing, demonstrating the possibility of high-speed operation of these devices. The differential gain was measured to be 5.3 × 10−17 cm2, and a gain compression factor of 2.87 × 10−17 cm3 is also derived from the small-signal modulation response.
Formation and annealing behaviors of qubit centers in 4H-SiC from first principles
Authors: Wang Xiaopeng , Zhao Mingwen , Bu Hongxia , Zhang Hongyu , He Xiujie , Wang Aizhu
Published: November 2013

Inspired by finding that the nitrogen-vacancy center in diamond is a qubit candidate, similar defects in silicon carbide (SiC) have drawn considerable interest. However, the generation and annealing behaviors of these defects remain unclear. Using first-principles calculations, we describe the equilibrium concentrations and annealing mechanisms based on the diffusion of silicon vacancies. The formation energies and energy barriers along different migration paths, which are responsible for the formation rates, stability, and concentrations of these defects, are investigated. The effects on these processes of charge states, annealing temperature, and crystal orientation are also discussed. These theoretical results are expected to be useful in achieving controllable generation of these defects in experiments.
Spin-controlled plasmonics via optical Rashba effect
Authors: Shitrit Nir , Yulevich Igor , Kleiner Vladimir , Hasman Erez
Published: November 2013

Observation of the optical Rashba effect in plasmonics is reported. Polarization helicity degeneracy removal, associated with the inversion symmetry violation, is attributed to the surface symmetry design via anisotropic nanoantennas with space-variant orientations. By utilizing the Rashba-induced momentum in a nanoscale kagome metastructure, we demonstrated a spin-based surface plasmon multidirectional excitation under a normal-incidence illumination. The spin-controlled plasmonics via spinoptical metasurfaces provides a route for spin-based surface-integrated photonic nanodevices and light-matter interaction control, extending the light manipulation capabilities.
High efficiency back-contact back-junction thin-film monocrystalline silicon solar cells from the porous silicon process
Authors: Haase F. , Kajari-Schröder S. , Brendel R.
Published: November 2013

This work demonstrates the fabrication of a 45 μm thick back-contact back-junction thin-film monocrystalline silicon solar cell from the porous silicon process with an energy conversion efficiency of 18.9%. We demonstrate an efficiency improvement of 5.4% absolute compared to our prior record of 13.5% for back-contact back-junction thin-film monocrystalline silicon solar cells. This increase in efficiency is achieved by reducing the recombination at the base contact using a back surface field and by increasing the generation with a front texture. We investigate the loss mechanisms in the cell using finite element simulations. A free energy loss analysis based on experiments and simulations determines the dominating loss mechanisms. The efficiency loss by base recombination is 0.8% absolute and the loss by base contact recombination is 0.5% absolute in the 18.9% efficiency cell.
Novel triple-band polarization-insensitive wide-angle ultra-thin microwave metamaterial absorber
Authors: Bian Borui , Liu Shaobin , Wang Shenyun , Kong Xiangkun , Zhang Haifeng , Ma Ben , Yang Huan
Published: November 2013

We report the design, analysis, fabrication, and measurement of a novel microwave triple-band metamaterial absorber that obtains three distinct high absorption peaks. The absorber is constructed of a periodic array of new resonant structure printed on a dielectric material with the thickness of λ/67 at the lowest fundamental resonant frequency. By manipulating the periodic patterned structures, significantly high absorption can be obtained at three specific resonance frequencies. This kind of triple-band absorber is polarization insensitive, and the absorption peaks remain high with large angles of incidence for both transverse electric and transverse magnetic polarizations, which provide more efficient absorptions for non-polarized or oblique incident electromagnetic wave. The experimental results show excellent absorption rates and the characteristic of polarization-insensitive for a wide range of incidence angles in the desired frequencies, which are in good correspondence with the simulated results.
Influence of clamping plate permeability and metal screen structures on three-dimensional magnetic field and eddy current loss in end region of a turbo-generator by numerical analysis
Authors: Likun Wang , Weili Li , Yi Xue , Chunwei Guan
Published: November 2013

A significant problem of turbogenerators on complex end structures is overheating of local parts caused by end losses in the end region. Therefore, it is important to investigate the 3-D magnetic field and eddy current loss in the end. In end region of operating large turbogenerator at thermal power plants, magnetic leakage field distribution is complex. In this paper, a 3-D mathematical model used for the calculation of the electromagnetic field in the end region of large turbo-generators is given. The influence of spatial locations of end structures, the actual shape and material of end windings, clamping plate, and copper screen are considered. Adopting the time–step finite element (FE) method and taking the nonlinear characteristics of the core into consideration, a 3-D transient magnetic field is calculated. The objective of this paper is to investigate the influence of clamping plate permeability and metal screen structures on 3-D electromagnetic field distribution and eddy current loss in end region of a turbo-generator. To reduce the temperature of copper screen, a hollow metal screen is proposed. The eddy current loss, which is gained from the 3D transient magnetic field, is used as heat source for the thermal field of end region. The calculated temperatures are compared with test data.
Electron effective mass in Al0.72Ga0.28N alloys determined by mid-infrared optical Hall effect
Authors: Schöche S. , Kühne P. , Hofmann T. , Schubert M. , Nilsson D. , Kakanakova-Georgieva A. , Janzén E. , Darakchieva V.
Published: November 2013

The effective electron mass parameter in Si-doped Al0.72Ga0.28N is determined to be m∗=(0.336±0.020) m0 from mid-infrared optical Hall effect measurements. No significant anisotropy of the effective electron mass parameter is found supporting theoretical predictions. Assuming a linear change of the effective electron mass with the Al content in AlGaN alloys and m∗=0.232 m0 for GaN, an average effective electron mass of m∗=0.376 m0 can be extrapolated for AlN. The analysis of mid-infrared spectroscopic ellipsometry measurements further confirms the two phonon mode behavior of the E1(TO) and one phonon mode behavior of the A1(LO) phonon mode in high-Al-content AlGaN alloys as seen in previous Raman scattering studies.
Synthesis of SiO2/β-SiC/graphite hybrid composite by low temperature hot filament chemical vapor deposition
Authors: Zhang Zhikun , Bian Jiming , Bi Kaifeng , Liu Yanhong , Zhang Dong , Qin Fuwen , Liu Hongzhu , Miao Lihua
Published: November 2013

β-SiC thin films were synthesized directly on graphite by hot filament chemical vapor deposition at low temperature. SiH4 diluted in hydrogen was employed as the silicon source, while graphite was functioned as both substrate and carbon source for the as-grown β-SiC films. X-ray diffraction and Fourier transform infrared analysis indicate that SiO2/β-SiC/graphite hybrid composite was formed after post annealing treatment, and its crystalline quality can be remarkably improved under optimized annealing conditions. The possible growth mechanism was proposed based on in situ etching of graphite by reactive hydrogen radicals at the atomic level.
The interplay between strain and size effects on the thermal conductance of grain boundaries in graphene
Authors: Tang Shengjie , Kulkarni Yashashree
Published: November 2013

The effect of strain on the thermal transport across grain boundaries in graphene is investigated using molecular dynamics simulations. The thermal boundary conductance is found to decrease significantly under biaxial tension as expected. In contrast, under biaxial compression, the thermal boundary conductance is strongly affected by the dimensions of the graphene monolayer, increasing with strain for specimen with length-to-width ratio of less than 20 and being insensitive to strain for length-to-width ratio above 20. This rather unexpected size-dependence under biaxial compression is found to be a result of geometric instabilities.
Note: Characteristic beam parameter for the line electron gun
Authors: Iqbal M. , Islam G. U. , Zhou Z. , Chi Y.
Published: November 2013

We have optimized the beam parameters of line source electron gun using Stanford Linear Accelerator Centre electron beam trajectory program (EGUN), utilizing electrostatic focusing only. We measured minimum beam diameter as 0.5 mm that corresponds to power density of 68.9 kW/cm2 at 13.5 mm in the post-anode region which is more than two-fold (33 kW/cm2), of the previously reported results. The gun was operated for the validation of the theoretical results and found in good agreement. The gun is now without any magnetic and electrostatic focusing thus much simpler and more powerful.
Charge carrier relaxation model in disordered organic semiconductors
Authors: Lu Nianduan , Li Ling , sun Pengxiao , Liu Ming
Published: November 2013

The relaxation phenomena of charge carrier in disordered organic semiconductors have been demonstrated and investigated theoretically. An analytical model describing the charge carrier relaxation is proposed based on the pure hopping transport theory. The relation between the material disorder, electric field and temperature and the relaxation phenomena has been discussed in detail, respectively. The calculated results reveal that the increase of electric field and temperature can promote the relaxation effect in disordered organic semiconductors, while the increase of material disorder will weaken the relaxation. The proposed model can explain well the stretched-exponential law by adopting the appropriate parameters. The calculation shows a good agreement with the experimental data for organic semiconductors.
Distribution of radiative crystal imperfections through a silicon ingot
Authors: Flø A. , Burud I. , Kvaal K. , Søndenå R. , Olsen E.
Published: November 2013

Crystal imperfections limit the efficiency of multicrystalline silicon solar cells. Recombination through traps is more prominent in areas with high density of crystal imperfections. A method to visualize the distribution of radiative emission from Shockley Read Hall recombination in silicon is demonstrated. We use hyperspectral photoluminescence, a fast non-destructive method, to image radiatively active recombination processes on a set of 50 wafers through a silicon block. The defect related emission lines D1 and D2 may be detected together or alone. The D3 and D4 seem to be correlated if we assume that an emission at the similar energy as D3 (VID3) is caused by a separate mechanism. The content of interstitial iron (Fei) correlates with D4. This method yields a spectral map of the inter band gap transitions, which opens up for a new way to characterize mechanisms related to loss of efficiency for solar cells processed from the block.
Growth of graphene underlayers by chemical vapor deposition
Authors: Fabiane Mopeli , Khamlich Saleh , Bello Abdulhakeem , Dangbegnon Julien , Momodu Damilola , Charlie Johnson A. T. , Manyala Ncholu
Published: November 2013

We present a simple and very convincing approach to visualizing that subsequent layers of graphene grow between the existing monolayer graphene and the copper catalyst in chemical vapor deposition (CVD). Graphene samples were grown by CVD and then transferred onto glass substrates by the bubbling method in two ways, either direct-transfer (DT) to yield poly (methyl methacrylate) (PMMA)/graphene/glass or (2) inverted transfer (IT) to yield graphene/PMMA/glass. Field emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM) were used to reveal surface features for both the DT and IT samples. The results from FE-SEM and AFM topographic analyses of the surfaces revealed the underlayer growth of subsequent layers. The subsequent layers in the IT samples are visualized as 3D structures, where the smaller graphene layers lie above the larger layers stacked in a concentric manner. The results support the formation of the so-called “inverted wedding cake” stacking in multilayer graphene growth.
Effect of graphene on plasmonic metasurfaces at infrared wavelengths
Authors: Ogawa Shinpei , Fujisawa Daisuke , Ueno Masashi
Published: November 2013

Significant enhancement of infrared transmittance by the presence of a graphene layer on a plasmonic metasurface (PLM) has been demonstrated. PLMs with different configurations were fabricated, and their transmittance with and without graphene was compared. Selective enhancement by graphene occurred at the plasmon resonance wavelength. The degree of enhancement was found to depend on the width of the gap between the periodic metal regions in the PLM. A maximum enhancement of ∼210% was achieved at a wavelength of 10 μm. The ability to achieve such a drastic increase in transmittance at the plasmon resonant wavelength is expected to lead to improvements in the performance of energy collecting devices and optical sensors.
Contributions of intrinsic mutation rate and selfish selection to levels of de novo
HRAS
mutations in the paternal germline
Authors: Giannoulatou Eleni , McVean Gilean , Taylor Indira B. , McGowan Simon J. , Maher Geoffrey J. , Iqbal Zamin , Pfeifer Susanne P. , Turner Isaac , Burkitt Wright Emma M. M. , Shorto Jennifer , Itani Aysha , Turner Karen , Gregory Lorna , Buck David , Rajpert-De Meyts Ewa , Looijenga Leendert H. J. , Kerr Bronwyn , Wilkie Andrew O. M. , Goriely Anne
Published: November 2013

Significance

Harvey rat sarcoma viral oncogene homolog (
HRAS
) occupies an important place in medical history, because it was the first gene in which acquired mutations that led to activation of a normal protein were associated with cancer, making it the prototype of the now canonical oncogene mechanism. Here, we explore what happens when similar
HRAS
mutations occur in male germ cells, an issue of practical importance because the mutations cause a serious congenital disorder, Costello syndrome, if transmitted to offspring. We provide evidence that the mutant germ cells are positively selected, leading to an increased burden of the mutations as men age. Although there are many parallels between this germline process and classical oncogenesis, there are interesting differences of detail, which are explored in this paper.
Genetic analysis of the metabolome exemplified using a rice population
Authors: Gong Liang , Chen Wei , Gao Yanqiang , Liu Xianqing , Zhang Hongyan , Xu Caiguo , Yu Sibin , Zhang Qifa , Luo Jie
Published: November 2013

Significance

Although plant metabolites are critical for both plant and human nutrition, the genetic control of the plant metabolome remains largely unknown. Here, a genetic analysis of the rice metabolome resulted in the identification of hundreds of metabolic quantitative trait loci with both high resolution and large effects. We observed distinct and overlapping accumulation patterns of metabolites and complex genetic regulation of metabolism in different tissues. Twenty-four candidate genes, mainly those underlying phenolics, were assigned and the corresponding pathways were reconstructed in rice. This study demonstrated a powerful tool and provided a vast amount of high-quality data for understanding the genetic and biochemical basis of the metabolome. It is also valuable for crop genetic improvement through metabolomics-assisted breeding.
Adaptive Fourier-Galerkin methods
Authors: Canuto C. , Nochetto R. , Verani M.
Published: November 2013

We study the performance of adaptive Fourier-Galerkin methods in a periodic box in

R

d

\mathbb {R}^d

with dimension

d
≥
1

d\ge 1

. These methods offer unlimited approximation power only restricted by solution and data regularity. They are of intrinsic interest but are also a first step towards understanding adaptivity for the

h
p

hp

-FEM. We examine two nonlinear approximation classes, one classical corresponding to algebraic decay of Fourier coefficients and another associated with exponential decay typical of spectral approximation. We investigate the natural sparsity class for the operator range and find that the exponential class is not preserved, thus in contrast with the algebraic class. This entails a striking different behavior of the feasible residuals that lead to practical algorithms, influencing the overall optimality. The sparsity degradation for the exponential class is partially compensated with coarsening. We present several feasible adaptive Fourier algorithms, prove their contraction properties, and examine the cardinality of the activated sets. The Galerkin approximations at the end of each iteration are quasi-optimal for both classes, but inner loops or intermediate approximations are sub-optimal for the exponential class.
XPC promotes MDM2-mediated degradation of the p53 tumor suppressor
Authors: Krzeszinski Jing Yan , Choe Vitnary , Shao Jia , Bao Xin , Cheng Haili , Luo Shiwen , Huo Keke , Rao Hai
Published: November 2013

Although ubiquitin receptor Rad23 has been implicated in bringing ubiquitylated p53 to the proteasome, how Rad23 recognizes p53 remains unclear. We demonstrate that XPC, a Rad23-binding protein, regulates p53 turnover. p53 protein in XPC-deficient cells remains ubiquitylated, but its association with the proteasome is drastically reduced, indicating that XPC regulates a postubiquitylation event. Furthermore, we found that XPC participates in the MDM2-mediated p53 degradation pathway via direct interaction with MDM2. XPC W690S pathogenic mutant is specifically defective for MDM2 binding and p53 degradation. p53 is known to become stabilized following UV irradiation but can be rendered unstable by XPC overexpression, underscoring a critical role of XPC in p53 regulation. Elucidation of the proteolytic role of XPC in cancer cells will help to unravel the detailed mechanisms underlying the coordination of DNA repair and proteolysis.
Growth Environment Influences Grain Protein Composition and Dough Functional Properties in Three Australian Wheat Cultivars
Authors: Hasniza M. Z. Noor , Wilkes Meredith A. , Uthayakumaran Surjani , Copeland Les
Published: November 2013

The objectives of this study were to assess how functional properties of proteins in whole meal wheat (Triticum aestivum L.) flour vary across different growth environments. Grain from three commercial Australian Hard milling wheat cultivars was analyzed from four growth locations in 2008 and from two of the corresponding cultivars and locations in 2009. The protein content of the grain, soluble and insoluble extractable protein fractions, swelling index of glutenin (SIG), glutenin‐to‐gliadin ratio (Glu:Gli), percent unextractable polymeric protein (%UPP), and dough properties including force at maximum resistance (Rmax) and extensibility were measured. Based on analysis of variance of aggregated data for the cultivars, growth locations, and seasons, growth environment factors made significant contributions to variability in the total grain protein, Glu:Gli ratio, %UPP, SIG, Rmax, and extensibility of the wheat flour. Variability of protein content of the soluble and insoluble extractable protein fractions was mostly owing to genotype.
In Situ Production of Zoospores by Five Species of Phytophthora in Aqueous Environments for Use as Inocula
Authors: Ridge G. A. , Jeffers S. N. , Bridges W. C. , White S. A.
Published: November 2013

The goal of this study was to develop a procedure that could be used to evaluate the potential susceptibility of aquatic plants used in constructed wetlands to species of Phytophthora commonly found in nurseries. V8 agar plugs from actively growing cultures of three or four isolates of Phytophthora cinnamomi, P. citrophthora, P. cryptogea, P. nicotianae, and P. palmivora were used to produce inocula. In a laboratory experiment, plugs were placed in plastic cups and covered with 1.5% nonsterile soil extract solution (SES) for 29 days, and zoospore presence and activity in the solution were monitored at 2- or 3-day intervals with a rhododendron leaf disk baiting bioassay. In a greenhouse experiment, plugs of each species of Phytophthora were placed in plastic pots and covered with either SES or Milli-Q water for 13 days during both summer and winter months, and zoospore presence in the solutions were monitored at 3-day intervals with the baiting bioassay and by filtration. Zoospores were present in solutions throughout the 29-day and 13-day experimental periods but consistency of zoospore release varied by species. In the laboratory experiment, colonization of leaf baits decreased over time for some species and often varied among isolates within a species. In the greenhouse experiment, bait colonization decreased over time in both summer and winter, varied among species of Phytophthora in the winter, and was better in Milli-Q water. Zoospore densities in solutions were greater in the summer than in the winter. Decreased zoospore activities for some species of Phytophthora were associated with prolonged temperatures below 13 or above 30°C in the greenhouse. Zoospores from plugs were released consistently in aqueous solutions for at least 13 days. This procedure can be used to provide in situ inocula for the five species of Phytophthora used in this study so that aquatic plant species can be evaluated for potential susceptibility.