bluuebunny/crossref_metadata_2025 huggingface dataset:
Protecting the radiation‐damaged skin from friction: a mini review
Authors: Herst Patries M.
Published: April 2014

Radiation‐induced skin reactions are an unavoidable side effect of external beam radiation therapy, particularly in areas prone to friction and excess moisture such as the axilla, head and neck region, perineum and skin folds. Clinical studies investigating interventions for preventing or managing these reactions have largely focussed on formulations with moisturising, anti‐inflammatory, anti‐microbial and wound healing properties. However, none of these interventions has emerged as a consistent candidate for best practice. Much less emphasis has been placed on evaluating ways to protect the radiation‐damaged skin from friction and excess moisture. This mini review analyses the clinical evidence for barrier products that form a protective layer by adhering very closely to the skin folds and do not cause further trauma to the radiation‐damaged skin upon removal. A database search identified only two types of barrier products that fitted these criteria and these were tested in two case series and six controlled clinical trials. Friction protection was most effective when the interventions were used from the start of treatment and continued for several weeks after completion of treatment. Soft silicone dressings (Mepilex Lite and Mepitel Film) and Cavilon No Sting Barrier Film, but not Cavilon Moisturizing Barrier Cream, decreased skin reaction severity, most likely due to differences in formulation and skin build‐up properties. It seems that prophylactic use of friction protection of areas at risk could be a worthwhile addition to routine care of radiation‐damaged skin.
A survey of radiographers' confidence and self‐perceived accuracy in frontline image interpretation and their continuing educational preferences
Authors: Neep Michael J. , Steffens Tom , Owen Rebecca , McPhail Steven M.
Published: April 2014

Introduction

The provision of a written comment on traumatic abnormalities of the musculoskeletal system detected by radiographers can assist referrers and may improve patient management, but the practice has not been widely adopted outside the United Kingdom. The purpose of this study was to investigate Australian radiographers' perceptions of their readiness for practice in a radiographer commenting system and their educational preferences in relation to two different delivery formats of image interpretation education, intensive and non‐intensive.

Methods

A cross‐sectional web‐based questionnaire was implemented between August and September 2012. Participants included radiographers with experience working in emergency settings at four Australian metropolitan hospitals. Conventional descriptive statistics, frequency histograms, and thematic analysis were undertaken. A Wilcoxon signed‐rank test examined whether a difference in preference ratings between intensive and non‐intensive education delivery was evident.

Results

The questionnaire was completed by 73 radiographers (68% response rate). Radiographers reported higher confidence and self‐perceived accuracy to detect traumatic abnormalities than to describe traumatic abnormalities of the musculoskeletal system. Radiographers frequently reported high desirability ratings for both the intensive and the non‐intensive education delivery, no difference in desirability ratings for these two formats was evident (z = 1.66, P = 0.11).

Conclusions

Some Australian radiographers perceive they are not ready to practise in a frontline radiographer commenting system. Overall, radiographers indicated mixed preferences for image interpretation education delivered via intensive and non‐intensive formats. Further research, preferably randomised trials, investigating the effectiveness of intensive and non‐intensive education formats of image interpretation education for radiographers is warranted.
Production of allitol from D‐psicose by a novel isolated strain of Klebsiella oxytoca G4A4
Authors: Han Wenjia , Zhu Yueming , Men Yan , Yang Jiangang , Liu Can , Sun Yuanxia
Published: April 2014

A novel bacterium capable of producing allitol from D‐psicose was isolated from soil and identified as Klebsiella oxytoca G4A4. An efficient method for the transformation of D‐psicose to allitol was achieved through the resting cell reaction. Ribitol as an inducer is suitable for cell cultivation, and cells are most active in Tris–HCl buffer (pH 8.0) at 37 °C with a density of 40 (OD600 nm). After the reaction, the final conversion rates of the washed cells were approximately 87, 83, and 55% at D‐psicose concentrations of 0.25, 0.5, and 1%, respectively. The product from D‐psicose was purified and determined to be allitol by high‐performance liquid chromatography and nuclear magnetic resonance spectroscopy.
From environmental signals to regulators: Modulation of biofilm development in Gram‐positive bacteria
Authors: Mhatre Eisha , Monterrosa Ramses Gallegos , Kovács Ákos T.
Published: April 2014

Bacterial lifestyle is influenced by environmental signals, and many differentiation processes in bacteria are governed by the threshold concentrations of molecules present in their niche. Biofilm is one such example where bacteria in their sessile state adapt to a lifestyle that causes several adaptive alterations in the population. Here, a brief overview is given on a variety of environmental signals that bias biofilm development in Gram‐positive bacteria, including nutrient conditions, self‐ and heterologously produced substances, like quorum sensing and host produced molecules. The Gram‐positive model organism, Bacillus subtilis is a superb example to illustrate how distinct signals activate sensor proteins that integrate the environmental signals towards global regulators related to biofilm formation. The role of reduced oxygen level, polyketides, antimicrobials, plant secreted carbohydrates, plant cell derived polymers, glycerol, and osmotic conditions are discussed during the transcriptional activation of biofilm related genes in B. subtilis.
Surface‐enhanced Raman scattering of pyridine‐functionalized multi‐walled carbon nanotubes
Authors: Anastasopoulos J. A. , Soto Beobide A. , Sygellou L. , Yannopoulos S. N. , Voyiatzis G. A.
Published: April 2014

Carbon nanotubes (CNTs) have attracted great attention for their potential use in many applications because of their intrinsic properties. The importance other than the impact of the application of CNT‐embedded membranes in the area of water technology development is immense. In this context, the identification and quantification of CNTs in aqueous resources during relevant water purification processes can be proven of high significance. Surface‐enhanced Raman scattering (SERS) potentially has the sensitivity required for trace analysis and has been previously used for CNT identification on solid substrates. A thorough study for the identification and quantification of small concentrations of multi‐walled CNTs (MWCNTs) in water suspensions via SERS has been performed. The functionalization of MWCNTs with pyridine groups seems to favor the surface enhancement of relevant Raman signal. This study constitutes the first step of a work in progress for the characterization of CNTs at quite low concentration range by SERS in any water suspension. It is based on an ex ante functionalization of the CNTs by pyridine, demonstrating the potential of the method. Our long‐term aim is its general application built, however, in an ex post relevant functionalization of the CNTs in any aqueous solution. Copyright © 2014 John Wiley & Sons, Ltd.
Assessing health in agriculture – towards a common research framework for soils, plants, animals, humans and ecosystems
Authors: Vieweger Anja , Döring Thomas F
Published: April 2014

In agriculture and food systems, health‐related research includes a vast diversity of topics. Nutritional, toxicological, pharmacological, epidemiological, behavioural, sociological, economic and political methods are used to study health in the five domains of soils, plants, livestock, humans and ecosystems. An idea developed in the early founding days of organic agriculture stated that the health of all domains is one and indivisible. Here we show that recent research reveals the existence and complex nature of such health links among domains. However, studies of health aspects in agriculture are often separated by disciplinary boundaries. This restrains the understanding of health in agricultural systems. Therefore we explore the opportunities and limitations of bringing perspectives together from the different domains. We review current approaches to define and assess health in agricultural contexts, comparing the state of the art of commonly used approaches and bringing together the presently disconnected debates in soil science, plant science, veterinary science and human medicine. Based on a qualitative literature analysis, we suggest that many health criteria fall into two paradigms: (1) the Growth Paradigm, where terms are primarily oriented towards continued growth; (2) the Boundary Paradigm, where terms focus on maintaining or coming back to a status quo, recognising system boundaries. Scientific health assessments in agricultural and food systems need to be explicit in terms of their position on the continuum between Growth Paradigm and Boundary Paradigm. Finally, we identify areas and concepts for a future direction of health assessment and research in agricultural and food systems. © 2014 Society of Chemical Industry
Kinetics and Mechanism of Oxidation of l‐Histidine by Permanganate Ions in Sulfuric Acid Medium
Authors: FAWZY A. , ASHOUR S. S. , MUSLEH M. A.
Published: April 2014

The reaction kinetics for the oxidation of l‐histidine by permanganate ions have been investigated spectrophotometrically in sulfuric acid medium at constant ionic strength and temperature. The order with respect to permanganate ions was found to be unity and second in acid concentration, whereas a fractional order is observed with respect to histidine. The reaction was observed to proceed through formation of a 1:1 intermediate complex between oxidant and substrate. The effect of the acid concentration suggests that the reaction is acid catalyzed. Increasing the ionic strength has no significant effect on the rate. The influence of temperature on the rate of reaction was studied. The presence of metal ion catalysts was found to accelerate the oxidation rate, and the order of effectiveness of the ions was Cu2+ > Ni2+ > Zn2+. The final oxidation products were identified as aldehyde (2‐imidazole acetaldehyde), ammonium ion, manganese(II), and carbon dioxide. Based on the kinetic results, a plausible reaction mechanism is proposed. The activation parameters were determined and discussed with respect to a slow reaction step.
Overcoming Cancer Multidrug Resistance by Codelivery of Doxorubicin and Verapamil with Hydrogel Nanoparticles
Authors: Qin Ming , Lee Yong‐Eun Koo , Ray Aniruddha , Kopelman Raoul
Published: April 2014

The efficacy of chemotherapy is often inhibited by multidrug resistance (MDR). A highly engineerable hydrogel nanoparticle (NP) serves as a carrier for the optimal codelivery to tumor cells of the chemodrug, doxorubicin (Dox) and the chemosensitizer, verapamil (Vera), aiming at alleviating tumor MDR. The hydrogel NPs are prepared via the copolymerization of acrylamide and 2‐carboxyethyl acrylate. Dox and Vera are post‐loaded into the respective NPs, with drug loading around 7.7 wt% and 8.0 wt%, respectively. The codelivery of Dox‐NPs and Vera‐NPs increases the intracellular accumulation of Dox, and significantly enhances the cell killing ability of Dox with respect to NCI/ADR‐RES cells in vitro. These findings suggest that such codelivery nanoplatforms provide a promising route for overcoming tumor MDR.
Optical and Electroluminescent Studies of White‐Light‐Emitting Copolymers Based on Poly(9,9‐dioctylfluorene) and Fluorenone Derivatives
Authors: Wang Hua , Yang Junli , Sun Jing , Xu Yang , Wu Yuling , Dong Qingcheng , Wong Wai‐Yeung , Hao Yuying , Zhang Xinwen , Li Hua
Published: April 2014

A novel type of single white‐light‐emitting copolymers, PF‐DTFOx, derived from poly(9,9‐dioctylfluorene) (PF) in which 2,7‐di‐(2‐thienyl)‐9‐fluorenone (DTFO) is introduced as an orange‐emitting unit, is reported, and their application in white‐light polymer light‐emitting devices (PLEDs) is explored. Because of the very simple structure of DTFO, the synthetic routes to PF‐DTFOx are not complicated, and the raw materials are cheap; these are advantageous in reducing the fabrication cost of white‐light PLEDs. In the fluorescence spectra, PF‐DTFOx in solid powder shows dual peaks at around 460 and 560 nm. In white‐light PLEDs, the color of the white‐light emission is tunable; this can be achieved by changing the content of DTFO in PF‐DTFOx. The light‐emission color varies from blue‐white to pure white and orange‐white when the composition of DTFO increases. All the PLEDs based on PF‐DTFOx exhibit maximum luminance above 1800 cd m−2 and a color rendering index above 80.

image
Honey bee colonies act as reservoirs for two Spiroplasma facultative symbionts and incur complex, multiyear infection dynamics
Authors: Schwarz Ryan S. , Teixeira Érica Weinstein , Tauber James P. , Birke Juliane M. , Martins Marta Fonseca , Fonseca Isabela , Evans Jay D.
Published: April 2014

Two species of Spiroplasma (Mollicutes) bacteria were isolated from and described as pathogens of the European honey bee, Apis mellifera, ~30 years ago but recent information on them is lacking despite global concern to understand bee population declines. Here we provide a comprehensive survey for the prevalence of these two Spiroplasma species in current populations of honey bees using improved molecular diagnostic techniques to assay multiyear colony samples from North America (U.S.A.) and South America (Brazil). Significant annual and seasonal fluctuations of Spiroplasma apis and Spiroplasma melliferum prevalence in colonies from the U.S.A. (n = 616) and Brazil (n = 139) occurred during surveys from 2011 through 2013. Overall, 33% of U.S.A. colonies and 54% of Brazil colonies were infected by Spiroplasma spp., where S. melliferum predominated over S. apis in both countries (25% vs. 14% and 44% vs. 38% frequency, respectively). Colonies were co‐infected by both species more frequently than expected in both countries and at a much higher rate in Brazil (52%) compared to the U.S.A. (16.5%). U.S.A. samples showed that both species were prevalent not only during spring, as expected from prior research, but also during other seasons. These findings demonstrate that the model of honey bee spiroplasmas as springtime‐restricted pathogens needs to be broadened and their role as occasional pathogens considered in current contexts.
Xenon NMR of phase biaxiality in liquid crystals
Authors: Jokisaari Jukka , Zhu Jianfeng
Published: April 2014

Biaxial thermotropic nematic liquid crystals would be of great importance in liquid crystal display technology. Less than a decade ago, such liquid crystals were suggested. The biaxiality of the phases was confirmed using2H NMR spectroscopy of deuterated probe molecules. The spectra were collected from a sample rotating around an axis perpendicular to the external magnetic field, resulting in a two‐dimensional powder pattern. We have proposed an alternate technique that is based on the second order quadrupole shift detectable in131Xe NMR spectra of dissolved xenon. The method has many advantages, such as the NMR spectra are taken from a static sample and the131Xe quadrupole coupling tensor is extremely sensitive to the symmetry of the phase. In the present study, we report results obtained on a 600‐MHz NMR spectrometer. Together with the data of our earlier study, they confirm that the asymmetry parameter of the131Xe quadrupole coupling tensor in the nematic phase of a ferroelectric liquid crystal is 0.85 and in the smectic A phase ca 0.62, indicating significant phase biaxiality. Copyright © 2014 John Wiley & Sons, Ltd.
Quantitative muscle ultrasound and quadriceps strength in patients with post‐polio syndrome
Authors: Bickerstaffe Alice , Beelen Anita , Zwarts Machiel J. , Nollet Frans , van Dijk Johannes P.
Published: April 2014

Introduction: We investigated whether muscle ultrasound can distinguish muscles affected by post‐polio syndrome (PPS) from healthy muscles and whether severity of ultrasound abnormalities is associated with muscle strength. Methods: Echo intensity, muscle thickness, and isometric strength of the quadriceps muscles were measured in 48 patients with PPS and 12 healthy controls. Results: Patients with PPS had significantly higher echo intensity and lower muscle thickness than healthy controls. In patients, both echo intensity and muscle thickness were associated independently with muscle strength. A combined measure of echo intensity and muscle thickness was more strongly related to muscle strength than either parameter alone. Conclusions: Quantitative ultrasound distinguishes healthy muscles from those affected by PPS, and measures of muscle quality and quantity are associated with muscle strength. Hence, ultrasound could be a useful tool for assessing disease severity and monitoring changes resulting from disease progression or clinical intervention in patients with PPS. Muscle Nerve 51: 24–29, 2015
A Simple Strategy to Prepare Colloidal Cu‐Doped ZnSe(S) Green Emitter Nanocrystals in Aqueous Media
Authors: de S. Viol Lívia C. , Raphael Ellen , Bettini Jefferson , Ferrari Jefferson L. , Schiavon Marco A.
Published: April 2014

A novel and simple method is described for preparing colloidal Cu‐doped ZnSe(S) quantum dots (QDs) in aqueous media by introducing copper ions using the same method as to prepare colloidal ZnSe(S). More specifically, the Cu‐doped ZnSe(S) are prepared through the nucleation‐doping method in the presence of 3‐mercaptopropionic acid as stabilizers using zinc perchlorate, copper sulphate, and NaHSe as precursors. Confirmation of the preparation of Cu‐doped ZnSe(S) nanocrystals (NCs) is done with absorption and emission spectroscopies (UV–vis and PL) as the QDs show intensive green emissions. The reduction of ions Cu2+ to Cu+ is confirmed by using electron paramagnetic resonance (EPR), in which Cu+ ions are silent. The size determination is performed by using transmission electron microscopy (TEM) and dynamic light scattering (DLS), resulting in Cu‐doped ZnSe(S) particles with a mean diameter of 4.6 ± 3.5 nm. The excellent stability observed for the nanoparticles overcomes the intrinsic instability of traditional aqueous Cu‐doped ZnSe(S) NCs.
Folding of Aquaporin 1: Multiple evidence that helix 3 can shift out of the membrane core
Authors: Virkki Minttu T. , Agrawal Nitin , Edsbäcker Elin , Cristobal Susana , Elofsson Arne , Kauko Anni
Published: April 2014

The folding of most integral membrane proteins follows a two‐step process: initially, individual transmembrane helices are inserted into the membrane by the Sec translocon. Thereafter, these helices fold to shape the final conformation of the protein. However, for some proteins, including Aquaporin 1 (AQP1), the folding appears to follow a more complicated path. AQP1 has been reported to first insert as a four‐helical intermediate, where helix 2 and 4 are not inserted into the membrane. In a second step, this intermediate is folded into a six‐helical topology. During this process, the orientation of the third helix is inverted. Here, we propose a mechanism for how this reorientation could be initiated: first, helix 3 slides out from the membrane core resulting in that the preceding loop enters the membrane. The final conformation could then be formed as helix 2, 3, and 4 are inserted into the membrane and the reentrant regions come together. We find support for the first step in this process by showing that the loop preceding helix 3 can insert into the membrane. Further, hydrophobicity curves, experimentally measured insertion efficiencies and MD‐simulations suggest that the barrier between these two hydrophobic regions is relatively low, supporting the idea that helix 3 can slide out of the membrane core, initiating the rearrangement process.
Using next‐generation sequencing to detect mutations endowing resistance to pesticides: application to acetolactate‐synthase (ALS)‐based resistance in barnyard grass, a polyploid grass weed
Authors: Délye Christophe , Causse Romain , Gautier Véronique , Poncet Charles , Michel Séverine
Published: April 2014

BACKGROUND

Next‐generation sequencing (NGS) technologies offer tremendous possibilities for accurate detection of mutations endowing pesticide resistance, yet their use for this purpose has not emerged in crop protection. This study aims at promoting NGS use for pesticide resistance diagnosis. It describes a simple procedure accessible to virtually any scientist and implementing freely accessible programs for the analysis of NGS data.

RESULTS

Three PCR amplicons encompassing seven codons of the acetolactate‐synthase gene crucial for herbicide resistance were sequenced using non‐quantified pools of crude DNA extracts from 40 plants in each of 28 field populations of barnyard grass, a polyploid weed. A total of 63 959 quality NGS sequence runs were obtained using the 454 technology. Three herbicide‐resistance‐endowing mutations (Pro‐197‐Ser, Pro‐197‐Leu and/or Trp‐574‐Leu) were identified in seven populations. The NGS results were confirmed by individual plant Sanger sequencing.

CONCLUSION

This work demonstrated the feasibility of NGS‐based detection of pesticide resistance, and the advantages of NGS compared with other molecular biology techniques for analysing large numbers of individuals. NGS‐based resistance diagnosis has the potential to play a substantial role in monitoring resistance, maintaining pesticide efficacy and optimising pesticide applications. © 2014 Society of Chemical Industry
Internal Migration and Early Life Mortality in Kenya and Nigeria
Authors: Mberu Blessing Uchenna , Mutua Michael
Published: April 2014

Building on evidence of the vulnerability of migrants to disadvantages in morbidity and mortality, we examine the relationships between internal migration and early life mortality. We apply the Cox‐proportional hazards model on the nationally representative data from the 2008 Demographic and Health Surveys in Kenya and Nigeria to predict the hazard of dying between birth and age 14.

We find more deaths in Nigeria than Kenya, with the highest mortality burdens among rural and urban non‐migrants in both countries. We also find urban–rural and rural–urban migrants in Kenya and rural–urban migrants in Nigeria showing elevated mortality burdens than other migrant categories. Consistent with evidence that social and biological disadvantages trail individuals through the life course, we find that distinct mortality patterns displayed after 2 years of life gradually enlarge till age 14 in both countries.

Beyond migration, we find commonalities in more deaths among children with shorter birth intervals, multiple than singleton births, children whose mothers have no/preschool education, with shortest duration of stay in current place of residence, divorced/separated, and from the poorest households.

On differentials, we find in Kenya higher mortality burdens among ethnic Somali children, in Northeastern and Western regions. In Nigeria, we find more deaths among boys, children of mothers under 20 years old, unemployed, Muslim, and from North‐west and North‐east regions.

Our study is a critical step in providing credible evidence that can guide discourse and actions in addressing the health challenges of migrants and non‐migrants in two major African countries. Copyright © 2014 John Wiley & Sons, Ltd.
Effect of gold nanoparticle in hole‐transport layer on inverted organic thin‐film solar cell performance
Authors: Akiyama Tsuyoshi , Nishida Takuji , Matsumoto Taisuke , Sakaguchi Hiroshi , Suzuki Atsushi , Oku Takeo
Published: April 2014

Inverted‐type bulk‐heterojunction organic thin‐film solar cells with incorporated gold nanoparticles were fabricated and evaluated. Gold nanoparticles were incorporated into the hole‐transport layer, and subsequently positioned behind the photoactive layer, away from the light‐facing side of the solar cell. Incorporation of gold nanoparticles was confirmed by scanning electro microscopy, atomic force microscopy, and transmission absorption spectra. The incorporation of the gold nanoparticles improved the performance of the photovoltaic device, even gold nanoparticles were aggregated in the hole‐transport layer.
Nanotube film metallicity and its effect on the performance of carbon nanotube–silicon solar cells
Authors: Tune Daniel D. , Blanch Adam J. , Krupke Ralph , Flavel Benjamin S. , Shapter Joseph G.
Published: April 2014

Research into silicon solar cells that use a thin film of single walled carbon nanotubes as the front electrode is an important area of increasing research activity. This paper provides the first ever direct performance comparison between devices fabricated with either semiconducting, metallic or mixed nanotubes to probe the effect of the semiconducting/metallic nature, or ‘metallicity’, of the nanotube film on solar cell performance and properties. HiPCO nanotube material sorted using the gel chromatography technique is highly purified in either metallic or semiconducting nanotube species. The solar cells fabricated with the metallic nanotubes greatly outperform their semiconducting or mixed counterparts. The operating mechanisms underlying this observation and its implications in regards to current understanding are discussed in light of recent literature. Dramatic increases in performance as well as substantial changes in the effect of metallicity due to subsequent hole doping of the sorted nanotube films are also demonstrated.

Using highly pure semiconducting and metallic carbon nanotubes, film metallicity is shown to be a vital factor in the performance of carbon nanotube–silicon solar cells.
Enhanced performance of InGaN light‐emitting diodes with InGaN/GaN superlattice and graded‐composition InGaN/GaN superlattice interlayers
Authors: Yang Yujue , Zeng Yiping
Published: April 2014

The advantages of InGaN‐based light‐emitting diodes (LEDs) with InGaN/GaN supperlattice (SL) and graded‐composition InGaN/GaN SL interlayers in the last‐barrier/EBL space are studied numerically. The electrostatic field, energy band diagrams, carrier concentrations, radiative recombination rate, light–current–voltage (L–I–V) performances, and internal quantum efficiency (IQE) are investigated. Simulation results show that the light‐output power and IQE are both enhanced compared to the conventional LED due to the appropriately modified energy band diagrams, which are favorable for the improvement in hole injection efficiency and electron blocking capability, especially for the LED with graded‐composition InGaN/GaN SL interlayer.
Improvement of dislocation density in thick CVD single crystal diamond films by coupling H2/O2 plasma etching and chemo‐mechanical or ICP treatment of HPHT substrates
Authors: Achard J. , Tallaire A. , Mille V. , Naamoun M. , Brinza O. , Boussadi A. , William L. , Gicquel A.
Published: April 2014

H2/O2 plasma treatments offer advantages over other etching processes of diamond as a technique to prepare the substrate's surface prior to homoepitaxial CVD diamond growth particularly in the case of thick films. It allows removing surface defects induced by polishing, thus leading to an improved morphology and limiting the stress within the grown crystal. Nevertheless, this treatment induces surface roughness leading to dislocation formation when CVD growth is initiated. In this paper we combined H2/O2 plasma etching with smoother surface treatment such as RIE‐ICP etching or Chemo‐Mechanical Polishing and we showed a significant reduction in dislocation density of the thick CVD epitaxial layers.
Magnetic properties of Gd‐doped GaN
Authors: Shvarkov Stepan , Ludwig Astrid , Wieck Andreas Dirk , Cordier Yvon , Ney Andreas , Hardtdegen Hilde , Haab Anna , Trampert Achim , Ranchal Rocío , Herfort Jens , Becker Hans‐Werner , Rogalla Detlef , Reuter Dirk
Published: April 2014

In this paper, we discuss the magnetic properties of Gd‐doped GaN. This diluted magnetic semiconductor shows hysteretic magnetization behavior at room temperature, which is attributed to ferromagnetism with a Curie temperature well above 300 K. However, the experimental results regarding the magnetic properties are not completely consistent and the microscopic origin for the reported magnetic properties is still unclear. We discuss the role of the growth method of the GaN comparing molecular beam epitaxy (MBE) and metal organic chemical vapor deposition (MOCVD) including GaN doped during the growth process with Gd as well as Gd‐implanted material. It seems that in general it is easier to obtain hysteretic magnetization behavior for MBE‐grown material probably due to the higher oxygen and lower hydrogen content. An exception is Gd‐implanted GaN MBE‐grown on Si(111) where we observe no ferromagnetism. We will present experiments where by oxygen implantation and annealing the impurity concentration was manipulated. The role of native defects is addressed and new experiments where additional defects have been introduced by nitrogen implantation in MBE‐grown GaN:Gd are discussed. We present our results on anomalous Hall effect observed in a Gd‐implanted GaN/AlGaN heterostructure.
The BOSCO solar cell – a both sides collecting and contacted structure
Authors: Fertig Fabian , Krauß Karin , Greulich Johannes , Clement Florian , Biro Daniel , Preu Ralf , Rein Stefan
Published: April 2014

The BOSCO solar cell represents a bifacial structure with double‐sided collection. The structure allows the use of standard module interconnection technology and favours the use of material with low to medium diffusion length and low resistivity for maximum benefit towards other structures, such as Al‐BSF and PERC. Within this work, we present first results on different multicrystalline silicon materials yielding a monofacial efficiency of 17.4% on large‐area wafers from block‐cast mc‐Si. This value represents a gain of ∼0.7%abs compared to Al‐BSF cells processed in parallel. The applicability for bifacial operation is demonstrated by a significantly increased quantum efficiency for rear side illumination. These results make the BOSCO solar cell concept a promising candidate to further boost the output of utility‐scale PV plants even when using low‐cost wafers of low to medium diffusion length material.

magnified image

Sketch and photographs of the BOSCO solar cell concept.

(© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Multi‐transfer: Transfer learning with multiple views and multiple sources
Authors: Tan Ben , Zhong Erheng , Xiang Evan Wei , Yang Qiang
Published: April 2014

Transfer learning, which aims to help learning tasks in a target domain by leveraging knowledge from auxiliary domains, has been demonstrated to be effective in different applications such as text mining, sentiment analysis, and so on. In addition, in many real‐world applications, auxiliary data are described from multiple perspectives and usually carried by multiple sources. For example, to help classify videos on Youtube, which include three perspectives: image, voice and subtitles, one may borrow data from Flickr, Last.FM and Google News. Although any single instance in these domains can only cover a part of the views available on Youtube, the piece of information carried by them may compensate one another. If we can exploit these auxiliary domains in a collective manner, and transfer the knowledge to the target domain, we can improve the target model building from multiple perspectives. In this article, we consider this transfer learning problem as Transfer Learning with Multiple Views and Multiple Sources. As different sources may have different probability distributions and different views may compensate or be inconsistent with each other, merging all data in a simplistic manner will not give an optimal result. Thus, we propose a novel algorithm to leverage knowledge from different views and sources collaboratively, by letting different views from different sources complement each other through a co‐training style framework, at the same time, it revises the distribution differences in different domains. We conduct empirical studies on several real‐world datasets to show that the proposed approach can improve the classification accuracy by up to 8% against different kinds of state‐of‐the‐art baselines.
Highly Active Metastable Ruthenium Nanoparticles for Hydrogen Production through the Catalytic Hydrolysis of Ammonia Borane
Authors: Abo‐Hamed Enass K. , Pennycook Timothy , Vaynzof Yana , Toprakcioglu Chris , Koutsioubas Alexandros , Scherman Oren A.
Published: April 2014

Late transition metal nanoparticles (NPs) with a favorably high surface area to volume ratio have garnered much interest for catalytic applications. Yet, these NPs are prone to aggregation in solution, which has been mitigated through attachment of surface ligands, additives or supports; unfortunately, protective ligands can severely reduce the effective surface area on the NPs available for catalyzing chemical transformations. The preparation of ‘metastable’ NPs can readily address these challenges. We report herein the first synthesis of monodisperse metastable ruthenium nanoparticles (RuNPs), having sub 5 nm size and an fcc structure, in aqueous media at room temperature, which can be stored for a period of at least 8 months. The RuNPs can subsequently be used for the catalytic, quantitative hydrolysis of ammonia‐borane (AB) yielding hydrogen gas with 21.8 turnovers per min at 25 °C. The high surface area available for hydrolysis of AB on the metastable RuNPs translated to an Ea of 27.5 kJ mol‐1, which is notably lower than previously reported values for RuNP based catalysts.
A tool to improve code‐first Web services discoverability through text mining techniques
Authors: Mateos Cristian , Rodriguez Juan Manuel , Zunino Alejandro
Published: April 2014

Service‐oriented development is challenging mainly because Web service developers tend to disregard the importance of the exposed service APIs, which are specified using Web Service Description Language (WSDL) documents. Methodologically, WSDL documents can be either manually generated or inferred from service implementations using WSDL generation tools. The latter option, called code first, is the most used approach in the industry. However, it is known that there are some bad practices in service implementations or defects in WSDL generation tools that may cause WSDL documents to present WSDL anti‐patterns, which in turn compromise the chances of documents of being discovered and understood. In this paper, we present a software tool that assists developers in obtaining WSDL documents with as few WSDL anti‐patterns as possible. The tool combines text mining and meta‐programming techniques to process service implementations and is developed as an Eclipse plug‐in. An evaluation of the tool by using a data‐set of real service implementations in terms of anti‐pattern avoidance accuracy and discovery performance by using classical Information Retrieval metrics—Precision‐at‐n, Recall and Normalized Discounted Cumulative Gain—is also reported.Copyright © 2014 John Wiley & Sons, Ltd.
The Hot Strength of Industrial Cokes – Evaluation of Coke Properties that Affect Its High‐Temperature Strength
Authors: Haapakangas Juho A. , Uusitalo Juha A. , Mattila Olli J. , Gornostayev Stanislav S. , Porter David A. , Fabritius Timo M. J.
Published: April 2014

The strength of coke at high temperatures is of major importance for efficient blast furnace operation. Despite this, there is little information regarding the hot strength of coke. In this research, the hot strength of three industrial European coke grades was studied using a Gleeble thermomechanical simulator. The hot strength was analyzed at three different temperatures: room temperature, 1600 and 1750 °C by measuring the compressive strength of roughly 50 coke samples at each temperature. A significant decrease in strength was observed for all three coke grades at high temperatures. Notable differences between the coke grades in compressive strength were observed at room temperature. At high temperatures, differences were observed in strength and deformation behavior; however, the order of magnitude of strength remained the same. The deformation behavior at high temperatures was also studied and discussed based on stress–strain curves. Several structural properties of coke such as total porosity, pore size distribution, pore shape factor, amount of inerts, and degree of graphitization were determined in order to explain the obtained strength results. Both hot and room temperature compressive strength values were compared to industrial strength tests and discussed. The reliability of the results was evaluated with statistical analyses.
Characterization of Briquettes Used for Slag Foaming in the EAF during Stainless Steel Production
Authors: Davydenko Arkadiy , Mostafaee Saman , Karasev Andrey , Jönsson Pär
Published: April 2014

The modern sustainable stainless steel making industry is characterized by different factors such as an efficient utilization of energy in the Electric Arc Furnace (EAF) by a slag foaming practice and an utilization of waste products from its own production facilities. In this study, the foaming briquettes applied for a combined slag foaming and waste product reduction in the EAF are characterized. The recipes of the briquettes were made based on a literature review and previous experience. Afterwards, the composition and density of briquettes were estimated and compared to calculated data. Moreover, weight reduction experiments were made on a laboratory scale at temperatures up to 1500 °C in an argon atmosphere in order to characterize the products (metal, slag, and gas). Based on these results, the calculations were compared with experimental data. The following main results were found: (i) the density of briquettes can be successfully verified, (ii) briquettes have different mechanical properties depending on the materials used for production of briquettes, and (iii) the briquettes yield in different amounts of metal and gas. Moreover, it was found that light briquettes (without FeCr) produced almost double the amount of gas in comparison with heavy briquettes (containing FeCr); valuable metals can be recovered from briquettes, and recipes of briquettes can be optimized based on the amount of metal droplets in briquettes and the total utilization of carbon.
Characterization of the effect of Cr(VI) on humoral innate immunity using Drosophila melanogaster
Authors: Pragya P. , Shukla A. K. , Murthy R. C. , Abdin M. Z. , Kar Chowdhuri D.
Published: April 2014

With the advancement of human race, different anthropogenic activities have heaped the environment with chemicals that can cause alteration in the immune system of exposed organism. As a first line of barrier, the evolutionary conserved innate immunity is crucial for the health of an organism. However, there is paucity of information regarding in vivo assessment of the effect of environmental chemicals on innate immunity. Therefore, we examined the effect of a widely used environmental chemical, Cr(VI), on humoral innate immune response using Drosophila melanogaster. The adverse effect of Cr(VI) on host humoral response was characterized by decreased gene expression of antimicrobial peptides (AMPs) in the exposed organism. Concurrently, a significantly decreased transcription of humoral pathway receptors (Toll and PGRP) and triglyceride level along with inhibition of antioxidant enzyme activities were observed in exposed organism. This in turn weakened the immune response of exposed organism that was manifested by their reduced resistance against bacterial infection. In addition, overexpression of the components of humoral immunity particularly Diptericin benefits Drosophila from Cr(VI)‐induced humoral immune‐suppressive effect. To our knowledge, this is the first report regarding negative impact of an environmental chemical on humoral innate immune response of Drosophila along with subsequent protection by AMPs, which may provide novel insight into host–chemical interactions. Also, our data validate the utility and sensitivity of Drosophila as a model that could be used for screening the possible risk of environmental chemicals on innate immunity with minimum ethical concern that can be further extrapolated to higher organisms. © 2014 Wiley Periodicals, Inc. Environ Toxicol 30: 1285–1296, 2015.
Performance analysis of switch‐based multiuser scheduling schemes with adaptive modulation in spectrum sharing systems
Authors: Qaraqe Marwa , Abdallah Mohamed , Serpedin Erchin , Alouini Mohamed‐Slim
Published: April 2014

This paper focuses on the development of multiuser access schemes for spectrum sharing systems whereby secondary users are allowed to share the spectrum with primary users under the condition that the interference observed at the primary receiver is below a predetermined threshold. In particular, two scheduling schemes are proposed for selecting a user among those that satisfy the interference constraint and achieve an acceptable signal‐to‐noise ratio level. The first scheme focuses on optimizing the average spectral efficiency by selecting the user that reports the best channel quality. In order to alleviate the relatively high feedback required by the first scheme, a second scheme based on the concept of switched diversity is proposed, where the base station (BS) scans the secondary users in a sequential manner until a user whose channel quality is above an acceptable predetermined threshold is found. We develop expressions for the statistics of the signal‐to‐interference and noise ratio as well as the average spectral efficiency, average feedback load, and the delay at the secondary BS. We then present numerical results for the effect of the number of users and the interference constraint on the optimal switching threshold and the system performance and show that our analysis results are in perfect agreement with the numerical results. Copyright © 2014 John Wiley & Sons, Ltd.
Aeroservoelastic state‐space vortex lattice modeling and load alleviation of wind turbine blades
Authors: Ng Bing Feng , Hesse Henrik , Palacios Rafael , Graham J.Michael R. , Kerrigan Eric C.
Published: April 2014

An aeroservoelastic model, capturing the structural response and the unsteady aerodynamics of turbine rotors, will be used to demonstrate the potential of active load alleviation using aerodynamic control surfaces. The structural model is a geometrically non‐linear composite beam, which is linearized around equilibrium rotating conditions and coupled with time‐domain aerodynamics given by a linearized 3D unsteady vortex lattice method. With much of the existing work relying on blade element momentum theory with various corrections, the use of the unsteady vortex lattice method in this paper seeks to complement and provide a direct higher fidelity solution for the unsteady rotor dynamics in attached flow conditions. The resulting aeroelastic model is in a state‐space formulation suitable for control synthesis. Flaps are modeled directly in the vortex lattice description and using a reduced‐order model of the coupled aeroelastic formulation, a linear‐quadratic‐Gaussian controller is synthesized and shown to reduce root mean square values of the root‐bending moment and tip deflection in the presence of continuous turbulence. Similar trend is obtained when the controller is applied to the original non‐linear model of the turbine. Trade‐offs between reducing root‐bending moment and suppressing the negative impacts on torsion due to flap deployment will also be investigated. Copyright © 2014 John Wiley & Sons, Ltd.
DEM of triaxial tests on crushable sand
Authors: de Bono J. P. , McDowell G. R.
Published: April 2014

This paper presents simulations of high-pressure triaxial shear tests on a crushable sand. The discrete element method is used, featuring a large number of particles and avoiding the use of agglomerates. The triaxial model features a flexible membrane, therefore allowing realistic deformation, and a simple breakage mechanism is implemented using the octahedral shear stress induced in the particles. The simulations show that particle crushing is essential to replicate the realistic behaviour of sand (in particular the volumetric contraction) in high-pressure shear tests. The general effects of crushing during shear are explored, including its effects on critical states, and the influence of particle strength and confining pressure on the degree of crushing are discussed.
The Utilization and Choices of Aneuploidy Screening in a Midwestern Population
Authors: Dicke Jeffrey M. , Van Duyne Lindsey , Bradshaw Rachael
Published: April 2014

The types, interpretation, and use of first‐ and second‐trimester aneuploidy screening are often unclear for many women. This impairs appropriate decision making and understanding of the implications of prenatal genetic testing options. The purpose of this study was to examine the utilization of Stepwise Sequential screening in our Midwestern population, demographic factors associated with choice of screening and method of risk reporting and it's potential impact on women's choices. First trimester screening was performed for 2,634 women during the study period. Results were not reported or “framed” as “positive” or “negative”. Rather, the specific age‐risk and screen‐risk for T21 were relayed, along with options for follow‐up Stepwise Sequential screening and invasive testing. Nearly 80 % of women declined Stepwise Sequential screening. Minorities and women of lower education were least likely to pursue further screening. Less than 4 % of the study population elected invasive testing. First trimester screening was associated with a 53 % reduction in amniocenteses and 20 % fewer CVS's compared to pre‐first trimester screening availability. Reporting age‐and screen‐risks for T21, rather than classifying results as “positive” or “negative” based on a pre‐determined threshold, was associated with a low uptake of further testing.
Maternal Uniparental Isodisomy Causing Autosomal Recessive GM1 Gangliosidosis: A Clinical Report
Authors: King Jessica E. , Dexter Amy , Gadi Inder , Zvereff Val , Martin Meaghan , Bloom Miriam , Vanderver Adeline , Pizzino Amy , Schmidt Johanna L.
Published: April 2014

Uniparental disomy is a genetic cause of disease that may result in the inheritance of an autosomal recessive condition. A child with developmental delay and hypotonia was seen and found to have severely abnormal myelination. Lysosomal enzyme testing identified an isolated deficiency of beta‐galactosidase. Subsequently, homozygous missense mutations in the galactosidase, beta 1 (GLB1) gene on chromosome 3 were found. Parental testing confirmed inheritance of two copies of the same mutated maternal GLB1 gene, and no paternal copy. SNP analysis was also done to confirm paternity. The patient was ultimately diagnosed with autosomal recessive GM1 gangliosidosis caused by maternal uniparental isodisomy. We provide a review of this patient and others in which uniparental disomy (UPD) of a non‐imprinted chromosome unexpectedly caused an autosomal recessive condition. This is the first case of GM1 gangliosidosis reported in the literature to have been caused by UPD. It is important for genetic counselors and other health care providers to be aware of the possibility of autosomal recessive disease caused by UPD. UPD as a cause of autosomal recessive disease drastically changes the recurrence risk for families, and discussions surrounding UPD can be complex. Working with families to understand UPD when it occurs requires a secure and trusting counselor‐family relationship.