bluuebunny/crossref_metadata_2025 huggingface dataset:
Intrinsic ductility of glassy solids
Authors: Shi Yunfeng , Luo Jian , Yuan Fenglin , Huang Liping
Published: January 2014

Glasses are usually brittle, seriously limiting their practical usage. Recently, the intrinsic ductility of glass was found to increase with the Poisson's ratio (v), with a sharp brittle-to-ductile (BTD) transition at vBTD = 0.31-0.32. Such a correlation between far-from-equilibrium fracture and near-equilibrium elasticity is unexpected and not understood. Molecular dynamics simulations, on three families of glasses (metallic glasses, amorphous silicon, and silica) with controlled bonding, processing, and testing conditions, show that glasses with low covalency and high structural disorder have high v and ductility, and vice versa. The BTD transitions triggered by the aforementioned causes in each system correspond to a unified vBTD value, which increases with its average coordination number (CN). The vBTD-CN relation can be comprehended by recognizing v as a measure of covalency and disorder, and the BTD transition as a competition between shear and cleavage. Our results provide guidelines for developing new recipes and processes for tough glasses.
A novel “correlated ion and neutral time of flight” method: Event-by-event detection of neutral and charged fragments in collision induced dissociation of mass selected ions
Authors: Teyssier C. , Fillol R. , Abdoul-Carime H. , Farizon B. , Farizon M. , Märk T. D.
Published: January 2014

A new tandem mass spectrometry (MS/MS) method based on time of flight measurements performed on an event-by-event detection technique is presented. This “correlated ion and neutral time of flight” method allows to explore Collision Induced Dissociation (CID) fragmentation processes by directly identifying not only all ions and neutral fragments produced but also their arrival time correlations within each single fragmentation event from a dissociating molecular ion. This constitutes a new step in the characterization of molecular ions. The method will be illustrated here for a prototypical case involving CID of protonated water clusters H+(H2O)n = 1–5 upon collisions with argon atoms.
Fractal diabolo antenna for enhancing and confining the optical magnetic field
Authors: Yang Y. , Dai H. T. , Sun X. W.
Published: January 2014

We introduce fractal geometry to diabolo nanoantenna for higher magnetic field intensity enhancement, i.e. the Sierpiński triangle diabolo antenna (STDA). Numerical results show that higher iteration of the STDA is responsible for the higher enhancement and the red shift of the resonant wavelength. Further investigation demonstrates the enhancement can be improved by increasing the length of the antenna or its central strip. By designing diabolo antennas with fractal geometry, improving the magnetic field intensity enhancement and varying the resonance conditions can be achieved while keeping the constant antenna dimensions.
Thermal transport through short-period SiGe nanodot superlattices
Authors: Chen Peixuan , Zhang J. J. , Feser J. P. , Pezzoli F. , Moutanabbir O. , Cecchi S. , Isella G. , Gemming T. , Baunack S. , Chen G. , Schmidt O. G. , Rastelli A.
Published: January 2014

The cross-plane thermal conductivity κ of multilayers of SiGe nanodots separated either by Si or SiGe can be decreased by reducing the period length or by increasing the nanodot density. It is, however, not clear how far κ can be reduced by using these strategies. In addition, the role of SiGe nanodots on the reduction of κ is still not fully understood. In this work, we addressed these issues by studying experimentally the cross-plane κ of Ge/Si superlattices with period lengths down to 1.5 nm. Although κ tends to preserve the decreasing trend with reducing the period length, for periods shorter than 2 nm we observed a drastic drop of the average thermal resistance per period. This finding indicates a weakening of the effect of the interfaces on phonon scattering and implies a lower limit for κ. To assess the role played by the nanodots in the reduction of κ we studied Ge/Si superlattices with nanodot densities varying from 0 to ∼8×1010 cm−2 and a fixed Si spacer thickness of 2.7 nm. The experimental results suggest that SiGe nanodots with ‘‘pyramid’’-shape have an effect comparable to nominally planar wetting layers on the cross-plane thermal transport. Finally, the comparison of superlattices with nanodots separated by Si1−xGex (with x from 0 to 0.2) shows that spacer alloying is beneficial in reducing the κ by ∼20%. The results presented in this work are expected to be relevant to micro/nanoscale energy conversion which requires minimizing the thermal conductivity of superlattice-based thin film thermoelectrics.
Polarity characterization by anomalous x-ray dispersion of ZnO films and GaN lateral polar structures
Authors: Shelton Christopher T. , Sachet Edward , Paisley Elizabeth A. , Hoffmann Marc P. , Rajan Joseph , Collazo Ramón , Sitar Zlatko , Maria Jon-Paul
Published: January 2014

We demonstrate the use of anomalous x-ray scattering of constituent cations at their absorption edge, in a conventional Bragg-Brentano diffractometer, to measure absolutely and quantitatively the polar orientation and polarity fraction of unipolar and mixed polar wurtzitic crystals. In one set of experiments, the gradual transition between c+ and c− polarity of epitaxial ZnO films on sapphire as a function of MgO buffer layer thickness is monitored quantitatively, while in a second experiment, we map the polarity of a lateral polar homojunction in GaN. The dispersion measurements are compared with piezoforce microscopy images, and we demonstrate how x-ray dispersion and scanning probe methods can provide complementary information that can discriminate between polarity fractions at a material surface and polarity fractions averaged over the film bulk.
Control of ferromagnetism by manipulating the carrier wavefunction in ferromagnetic semiconductor (In,Fe)As quantum wells
Authors: Duc Anh Le , Nam Hai Pham , Tanaka Masaaki
Published: January 2014

We demonstrated the control of ferromagnetism in a surface quantum well containing a 5 nm-thick n-type ferromagnetic semiconductor (FMS) (In,Fe)As layer sandwiched between two InAs layers, by manipulating the carrier wavefunction. The Curie temperature (TC) of the (In,Fe)As layer was effectively changed by up to 12 K (ΔTC/TC = 55%). Our calculation using the mean-field Zener theory reveals an unexpectedly large s-d exchange interaction in (In,Fe)As. Our results establish an effective way to control the ferromagnetism in quantum heterostructures of n-type FMSs, as well as require reconsideration on the current understanding of the s-d exchange interaction in narrow gap FMSs.
Thermal expansion recovery microscopy: Practical design considerations
Authors: Mingolo N. , Martínez O. E.
Published: January 2014

A detailed study of relevant parameters for the design and operation of a photothermal microscope technique recently introduced is presented. The technique, named thermal expansion recovery microscopy (ThERM) relies in the measurement of the defocusing introduced by a surface that expands and recovers upon the heating from a modulated source. A new two lens design is presented that can be easily adapted to commercial infinite conjugate microscopes and the sensitivity to misalignment is analyzed. The way to determine the beam size by means of a focus scan and the use of that same scan to verify if a thermoreflectance signal is overlapping with the desired ThERM mechanism are discussed. Finally, a method to cancel the thermoreflectance signal by an adequate choice of a nanometric coating is presented.
Acoustical “transparency” induced by local resonance in Bragg bandgaps
Authors: Yu Gaokun , Wang Xinlong
Published: January 2014

We show that sound waves can resonantly transmit through Bragg bandgaps in an acoustical duct periodically attached with an array of Helmholtz resonators, forming within the normally forbidden band a transparency window with group velocity smaller than the normal speed of sound. The transparency occurs for the locally resonant frequency so much close to the Bragg one that both the local-resonance-induced bandgap and the Bragg one heavily overlap with each other. The phenomenon seems an acoustical analog of the well-known electromagnetically induced transparency by quantum interference. Different from the Fano-like interference explanation, we also provide a mechanism for the transparency window phenomenon which makes it possible to extend the phenomenon in general.
Spin polarization in one dimensional ring with Rashba spin-orbit interaction
Authors: Liu Duan-Yang , Xia Jian-Bai
Published: January 2014

We investigate theoretically spin polarization in a square AB ring and in a circular AB ring with the Rashba spin-orbit interaction (RSOI) and the magnetic flux. It is shown that in the presence of both the RSOI and the perpendicular magnetic field, the AB rings can work as a spin polarizer, and the spin polarization transport can be modulated by the values of the system parameters. In addition, we find that the square ring is more suitable for a spin polarizer due to its higher stability.
Measuring the inverse magnetostrictive effect in a thin film using a modified vibrating sample magnetometer
Authors: Buford Benjamin , Dhagat Pallavi , Jander Albrecht
Published: January 2014

A method for measuring the magnetostriction of thin films using a vibrating sample magnetometer is described. We describe the design of a custom sample holder to apply an adjustable bending stress to the sample during measurement and observe the resulting change in the M-H loop.
Electric current induced flow of liquid metals: Mechanism and substrate-surface effects
Authors: Kumar P. , Howarth J. , Dutta I.
Published: January 2014

Long range, continuous flow of liquid metals occurs upon application of an electric current. Here, we report experimental results elucidating the mechanism of current-induced liquid metal flow, and its dependence on substrate surface condition. It is shown that the observed flow is diffusion-controlled, with the flow-rate depending linearly on applied current density, indicating that it is driven by electromigration. The effective charge number for liquid electromigration, Z*, of several pure metals, such as Al, Bi, Ga, Sn, and Pb, were deduced from the experimental results and were found to be close to the elemental valency. With the exception of liquid Pb, Z* for all liquid metals tested in this study were positive, indicating that: (i) electron wind contributes much less to Z* in liquid metals than in solids, and (ii) with a few exceptions, liquid metals generally flow in the direction of the electric current. On smooth substrates which are wetted well by the liquid metal, flow occurs in a thin, continuous stream. On rough surfaces which are poorly wetted, on the other hand, discrete beads of liquid form, with mass transport between adjacent beads occurring by surface diffusion on the substrate. A rationale for the role of substrate roughness in fostering this observed transition in flow mechanism is presented.
Hydrogen in tin dioxide films and bulk ceramics: An attempt to identify the most hidden impurity
Authors: Watanabe Ken , Hashiguchi Minako , Sakaguchi Isao , Bryant Alex , Adachi Yutaka , Zhen Yuhua , Ohgaki Takeshi , Ohsawa Takeo , Haneda Hajime , Ohashi Naoki
Published: January 2014

Hydrogen impurities in SnO2 films and bulk ceramics were investigated in terms of mass transport and electron transport. The hydrogen concentration (n[H]) in these samples was found to be 1019 cm−3 or higher. Further increase in n[H] could be achieved by annealing the samples in a humid atmosphere. The isotope tracer (1H/2H exchange) study revealed that a part of the hydrogen in these samples showed rapid migration even at 300 °C. However, electrical measurements revealed that the electron concentration in the samples was much less than n[H]. These results could be explained by assuming the presence of defect-hydrogen complexes.
Schottky junction solar cells based on graphene with different numbers of layers
Authors: Li Y. F. , Yang W. , Tu Z. Q. , Liu Z. C. , Yang F. , Zhang L. Q. , Hatakeyama R.
Published: January 2014

We have investigated the performance of Schottky junction solar cells based on silicon and graphene with 1–6 layers. The open-circuit voltage of solar cells shows an increase when increasing the number of graphene layers. However, the power conversion efficiency and short-circuit current density increase monotonically when the number of graphene layers is less than 4 and reduces as the number of graphene layers further increases. Our results demonstrate that the number of layers related to the work function and transmission of graphene plays a critical role in determining the performance of solar cells.
Microstructure of highly strained BiFeO3 thin films: Transmission electron microscopy and electron-energy loss spectroscopy studies
Authors: Heon Kim Young , Bhatnagar Akash , Pippel Eckhard , Alexe Marin , Hesse Dietrich
Published: January 2014

Microstructure and electronic structure of highly strained bismuth ferrite (BiFeO3) thin films grown on lanthanum aluminate substrates are studied using high-resolution transmission and scanning transmission electron microscopies and electron energy loss spectroscopy (EELS). Monoclinic and tetragonal phases were observed in films grown at different temperatures, and a mix of both phases was detected in a film grown at intermediate temperature. In this film, a smooth transition of the microstructure was found between the monoclinic and the tetragonal phases. A considerable increase in the c-axis parameters was observed in both phases compared with the rhombohedral bulk phase. The off-center displacement of iron (Fe) ions was increased in the monoclinic phase as compared with the tetragonal phase. EEL spectra show different electronic structures in the monoclinic and the tetragonal phases. These experimental observations are well consistent with the results of theoretical first-principle calculations performed.
Court Historiography of the Seljuq Empire in Iran and Iraq: Reflections on Content, Authorship and Language
Authors: Peacock A.C.S.
Published: January 2014

This paper reexamines the Arabic and Persian historical literature of the Seljuq period (1040–1194), concentrating on works produced in circles connected with the sultanic court. It considers the relationship between the Arabic and Persian works, the authors' motives for composition, and the reasons for choice of language. It also compares these works with their predecessors, especially the historiography of the Ghaznavid court, with a view to assessing the particular characteristics of Seljuq historical writing, which is often considered rather slight and unimpressive. One reason that is often adduced for this is the absence of dynastic history writing under the Seljuqs, and the alleged lack of interest of the Seljuq court in patronizing historiography, themes which we also investigate here.
Spatial Interferences in Mental Arithmetic: Evidence from the Motion–Arithmetic Compatibility Effect
Authors: Wiemers Michael , Bekkering Harold , Lindemann Oliver
Published: January 2014

Recent research on spatial number representations suggests that the number space is not necessarily horizontally organized and might also be affected by acquired associations between magnitude and sensory experiences in vertical space. Evidence for this claim is, however, controversial. The present study now aims to compare vertical and horizontal spatial associations in mental arithmetic. In Experiment 1, participants solved addition and subtraction problems and indicated the result verbally while moving their outstretched right arm continuously left-, right-, up-, or downwards. The analysis of the problem-solving performances revealed a motion–arithmetic compatibility effect for spatial actions along both the horizontal and the vertical axes. Performances in additions was impaired while making downward compared to upward movements as well as when moving left compared to right and vice versa in subtractions. In Experiment 2, instead of being instructed to perform active body movements, participants calculated while the problems moved in one of the four relative directions on the screen. For visual motions, only the motion–arithmetic compatibility effect for the vertical dimension could be replicated. Taken together, our findings provide first evidence for an impact of spatial processing on mental arithmetic. Moreover, the stronger effect of the vertical dimension supports the idea that mental calculations operate on representations of numerical magnitude that are grounded in a vertically organized mental number space.
Constructing argument graphs with deductive arguments: a tutorial
Authors: Besnard Philippe , Hunter Anthony
Published: January 2014

A deductive argument is a pair where the first item is a set of premises, the second item is a claim, and the premises entail the claim. This can be formalised by assuming a logical language for the premises and the claim, and logical entailment (or consequence relation) for showing that the claim follows from the premises. Examples of logics that can be used include classical logic, modal logic, description logic, temporal logic, and conditional logic. A counterargument for an argument A is an argument B where the claim of B contradicts the premises of A. Different choices of logic, and different choices for the precise definitions of argument and counterargument, give us a range of possibilities for formalising deductive argumentation. Further options are available to us for choosing the arguments and counterarguments we put into an argument graph. If we are to construct an argument graph based on the arguments that can be constructed from a knowledgebase, then we can be exhaustive in including all arguments and counterarguments that can be constructed from the knowledgebase. But there are other options available to us. We consider some of the possibilities in this review.
The ASPIC+ framework for structured argumentation: a tutorial
Authors: Modgil Sanjay , Prakken Henry
Published: January 2014

This article gives a tutorial introduction to the ASPIC+ framework for structured argumentation. The philosophical and conceptual underpinnings of ASPIC+ are discussed, the main definitions are illustrated with examples and several ways are discussed to instantiate the framework and to reconstruct other approaches as special cases of the framework. The ASPIC+ framework is based on two ideas: the first is that conflicts between arguments are often resolved with explicit preferences, and the second is that arguments are built with two kinds of inference rules: strict, or deductive rules, whose premises guarantee their conclusion, and defeasible rules, whose premises only create a presumption in favour of their conclusion. Accordingly, arguments can in ASPIC+ be attacked in three ways: on their uncertain premises, or on their defeasible inferences, or on the conclusions of their defeasible inferences. ASPIC+ is not a system but a framework for specifying systems. A main objective of the study of the ASPIC+ framework is to identify conditions under which instantiations of the framework satisfy logical consistency and closure properties.
From the precariat to the multitude
Authors: Trott Ben
Published: January 2014

This paper situates Guy Standing’s recent work on ‘the precariat’ within a broader body of literature exploring processes of ‘precarisation’, at work and across the social field. It sets out the differential distribution of ‘precarity’ (including on the basis of gender, geography, status and sector) resulting from transformations in labour and the political economy, the rollback of social democracy and of ‘industrial citizenship’ (where these existed), as well as from processes of globalisation. The paper argues that, like many other works, Standing’s book, The Precariat: The New Dangerous Class, de-couples its discussion of precarious, neoliberal labour and life from the explicitly utopian agenda of radical reform it ultimately proposes. Drawing on Kathi Weeks’ engagement with Ernst Bloch’s work, the paper suggest Standing’s utopianism remains abstract, detached from an analysis of the social forces, movements and struggles that might bring it into being. It makes use of Antonio Negri’s distinctive, heterodox interpretation of V.I. Lenin to provide a framework for theorising how concrete utopian projects of radical political transformation – which is to say, ‘realist’ or materialist ones – are extrapolated out of spontaneous struggles; the predominant ‘will’, ethics and structures of which are always largely determined by the social, political and economic context from which they emerge. It is shown how, on the basis of this approach, Negri (in his collaboration with Michael Hardt) has constructed the notion of ‘multitude’ as a potential model for political organisation today – apposite to the precarious reality described by Standing and others. They draw on Baruch Spinoza’s political philosophy – often counterposing it to that of Thomas Hobbes – to affirm the capacity for common political action and decision despite heterogeneity, and to ground political organisation in social conflict rather than contract. Finally, drawing on Alain Badiou’s distinction between ‘immediate’ and ‘historical uprisings’, the paper explores the degree to which a number of contemporary movements and struggles might have tentatively achieved what he calls ‘qualitative extension’ – establishing connections and a ground for common action across social spaces and strata – potentially setting in motion enduring projects of political organisation and constitution that resemble the multitude model.
Top eigenvalue of a random matrix: large deviations and third order phase transition
Authors: Majumdar Satya N , Schehr Grégory
Published: January 2014

We study the fluctuations of the largest eigenvalue λ
max of N × N random matrices in the limit of large N. The main focus is on Gaussian β ensembles, including in particular the Gaussian orthogonal (β = 1), unitary (β = 2) and symplectic (β = 4) ensembles. The probability density function (PDF) of λ
max consists, for large N, of a central part described by Tracy–Widom distributions flanked, on both sides, by two large deviation tails. While the central part characterizes the typical fluctuations of λ
max—of order

—the large deviation tails are instead associated with extremely rare fluctuations—of order

. Here we review some recent developments in the theory of these extremely rare events using a Coulomb gas approach. We discuss in particular the third order phase transition which separates the left tail from the right tail, a transition akin to the so-called Gross–Witten–Wadia phase transition found in 2-d lattice quantum chromodynamics. We also discuss the occurrence of similar third order transitions in various physical problems, including non-intersecting Brownian motions, conductance fluctuations in mesoscopic physics and entanglement in a bipartite system.
Diverse and widespread contamination evident in the unmapped depths of high throughput sequencing data
Authors: Lusk Richard W.
Published: January 2014

Background

Trace quantities of contaminating DNA are widespread in the laboratory environment, but their presence has received little attention in the context of high throughput sequencing. This issue is highlighted by recent works that have rested controversial claims upon sequencing data that appear to support the presence of unexpected exogenous species.

Results

I used reads that preferentially aligned to alternate genomes to infer the distribution of potential contaminant species in a set of independent sequencing experiments. I confirmed that dilute samples are more exposed to contaminating DNA, and, focusing on four single-cell sequencing experiments, found that these contaminants appear to originate from a wide diversity of clades. Although negative control libraries prepared from ‘blank’ samples recovered the highest-frequency contaminants, low-frequency contaminants, which appeared to make heterogeneous contributions to samples prepared in parallel within a single experiment, were not well controlled for. I used these results to show that, despite heavy replication and plausible controls, contamination can explain all of the observations used to support a recent claim that complete genes pass from food to human blood.

Conclusions

Contamination must be considered a potential source of signals of exogenous species in sequencing data, even if these signals are replicated in independent experiments, vary across conditions, or indicate a species which seemsa prioriunlikely to contaminate. Negative control libraries processed in parallel are essential to control for contaminant DNAs, but their limited ability to recover low-frequency contaminants must be recognized.
Structural basis for catalysis and ubiquitin recognition by theSevere acute respiratory syndrome coronaviruspapain-like protease
Authors: Chou Chi-Yuan , Lai Hsing-Yi , Chen Hung-Yi , Cheng Shu-Chun , Cheng Kai-Wen , Chou Ya-Wen
Published: January 2014

Papain-like protease (PLpro) is one of two cysteine proteases involved in the proteolytic processing of the polyproteins ofSevere acute respiratory syndrome coronavirus(SARS-CoV). PLproalso shows significantin vitrodeubiquitinating and de-ISGylating activities, although the detailed mechanism is still unclear. Here, the crystal structure of SARS-CoV PLproC112S mutant in complex with ubiquitin (Ub) is reported at 1.4 Å resolution. The Ub core makes mostly hydrophilic interactions with PLpro, while the Leu-Arg-Gly-Gly C-terminus of Ub is located in the catalytic cleft of PLpro, mimicking the P4–P1 residues and providing the first atomic insights into its catalysis. One of the O atoms of the C-terminal Gly residue of Ub is located in the oxyanion hole consisting of the main-chain amides of residues 112 and 113. Mutations of residues in the PLpro–Ub interface lead to reduced catalytic activity, confirming their importance for Ub binding and/or catalysis. The structure also revealed anN-cyclohexyl-2-aminethanesulfonic acid molecule near the catalytic triad, and kinetic studies suggest that this binding site is also used by other PLproinhibitors. Overall, the structure provides a foundation for understanding the molecular basis of coronaviral PLprocatalysis.
Case of lepromatous leprosy misdiagnosed as systemic sclerosis
Authors: Lee Jin Yong , Park So Eun , Shin Soo Jung , Kim Chul Woo , Kim Sang Seok
Published: January 2014

Hansen's disease (HD) is a chronic granulomatous infectious disease caused by Mycobacterium leprae. The worldwide prevalence rate of HD has decreased gradually over the years. The clinical manifestations of HD are extensive, with involvement of the skin and various organs, and these can resemble those of many rheumatic diseases. Our patient initially presented with gradual sclerotic skin change and slight sclerodactyly with Raynaud's phenomenon, which is frequently observed in systemic sclerosis. However, a skin biopsy with acid‐fast stain later confirmed lepromatous leprosy. We report this case to emphasize the role of dermatologists for applying a systematic approach to the skin lesions of HD, which has become difficult to detect because of its rapidly declining prevalence rate.
Differential immunostaining of various types of breast carcinomas for growth hormone‐releasing hormone receptor – Apocrine epithelium and carcinomas emerging as uniformly positive
Authors: Kővári Bence , Rusz Orsolya , Schally Andrew V. , Kahán Zsuzsanna , Cserni Gábor
Published: January 2014

Different classes of breast cancers were explored for their positivity for growth hormone‐releasing hormone receptors (GHRH‐R) in this pilot study, as no systematic evaluation of such tumors has been performed to date. Seventy‐two small primary breast carcinomas were evaluated for GHRH‐R expression by immunohistochemistry using a polyclonal antibody and a cutoff value of 10% staining. GHRH‐R positivity was detected in 58% of all cases, 20/23 (87%) of invasive lobular carcinomas (ILC) and 22/46 (48%) of invasive ductal carcinomas (IDC). GHRH‐R positivity was more frequent in grade 2 tumors (86%), as compared to grade 1 (18%) or grade 3 (47%) cancers. GHRH‐R expression was not associated with mitotic scores, the Ki‐67 labeling indices or nodal status. IDCs with casting‐type calcifications on the mammogram showed positivity for GHRH‐R in 9/12 (75%) cases. Most importantly, apocrine epithelium, and all 10 apocrine carcinomas added later to the study were GHRH‐R‐positive. These preliminary results suggest a greater than average GHRH‐R expression in ILCs and IDCs associated with casting‐type calcifications on the mammogram. Apocrine carcinomas seem uniformly positive for GHRH‐R. Whether these findings could indicate a potential role of GHRH‐antagonists in targeted treatment of these types of breast cancer requires further studies.
Extensive experience in the management of macroprolactinomas
Authors: Green Anna I. , Sherlock Mark , Stewart Paul M. , Gittoes Neil J. , Toogood Andrew A.
Published: January 2014

Objectives

Macroprolactinomas are pituitary tumours that can be managed with dopamine agonists (DA), surgery and radiotherapy. We aimed to assess the outcomes of these treatment modalities.

Design

Retrospective case‐note study of patients managed in a single tertiary referral centre.

Patients

One hundred patients (68 male) diagnosed with macroprolactinoma between 1971 and 2009.

Measurements

We assessed the response to first‐line treatment in terms of reduction in serum prolactin, endocrine status, symptomatic improvement and tumour shrinkage. Patients were divided into a group that received only DA therapy and a group that received surgery, radiotherapy or both, with or without a DA. We compared pituitary function at baseline and at last clinic visit between the two groups.

Results

In total, there were 1170 patient years of follow‐up. Pituitary surgery was performed in 29/100 patients. Fourteen patients received pituitary radiotherapy (8/14 surgery also). At last clinic visit, the nonmedical therapy group had a higher risk of gonadotrophin deficiency (77·4% vs 44·8%, P = 0·0037), TSH deficiency (54·8% vs 25·4%, P = 0·0009) and ACTH deficiency (56·2% vs 17·2%, P = 0·0001). When last reviewed, 23/29 (79·3%) patients who underwent surgery and 10/14 (71·4%) patients who received radiotherapy were taking a DA.

Conclusions

Treatment with a DA alone is associated with better outcomes in terms of pituitary function and as such represents the optimal first‐line therapy for macroprolactinomas. Surgery and radiotherapy should be reserved for patients who are either intolerant of or resistant to DAs. Following surgery and/or radiotherapy, the majority of patients still require a DA for control of prolactin hypersecretion.
Epilepsy‐related brain networks in ring chromosome 20 syndrome: An EEG‐fMRI study
Authors: Vaudano Anna Elisabetta , Ruggieri Andrea , Vignoli Aglaia , Avanzini Pietro , Benuzzi Francesca , Gessaroli Giuliana , Nichelli Paolo Frigio , Darra Francesca , Cantalupo Gaetano , Mastrangelo Massimo , Dalla Bernardina Bernardo , Canevini Maria Paola , Meletti Stefano
Published: January 2014

Objective

To identify the brain networks that are involved in the different electroencephalography (EEG) abnormalities in patients with ring chromosome 20 [r(20)] syndrome. We hypothesize the existence of both distinctive and common brain circuits for the paroxysmal high voltage sharp waves (hSWs), the seizures, and the slow‐wave 3–7 Hz rhythm that characterize this condition.

Methods

Thirteen patients with [r(20)] syndrome were studied by means of EEG simultaneously recorded with functional magnetic resonance imaging (EEG‐fMRI). EEG traces were reviewed in order to detect the pathologic interictal (hSWs) and ictal activities; the 3–7 Hz theta‐delta power was derived using a fast Fourier transform. A group‐level analysis was performed for each type of EEG abnormality separately using a fixed‐effect model and a conjunction analysis. Finally, a second‐level random‐effect model was applied considering together the different EEG abnormalities, without distinction between hSW, seizures, or theta‐delta rhythms.

Results

Subcontinuous theta‐delta rhythm was recorded in seven patients, seizures in two, and hSWs in three patients. The main results are the following: (1) the slow‐wave rhythm was related to blood oxygen level–dependent (BOLD) increases in the premotor, sensory‐motor, and temporoparietal cortex, and to BOLD decrements involving the default mode (DMN) and the dorsal attention networks (DANs); (2) the ictal‐related BOLD changes showed an early involvement of the prefrontal lobe; (3) increases in BOLD signal over the basal ganglia, either for interictal and ictal activities, were observed; (4) a common pattern of positive BOLD changes in the bilateral perisylvian regions was found across the different EEG abnormalities.

Significance

The BOLD increment in the perisylvian network and the decrease of the DMN and DAN could be the expression of the [r(20)] syndrome–related cognitive and behavioral deficits. The observed BOLD patterns are similar to the ones detected in other epileptic encephalopathies, suggesting that different epileptic disorders characterized by neurobehavioral regression are associated with dysfunction in similar brain networks.

A PowerPoint slide summarizing this article is available for download in the Supporting Information section here.
In Vitro Biomechanical Comparison of 3.5 mm LC‐DCP/Intramedullary Rod and 5 mm Clamp‐Rod Internal Fixator (CRIF)/Intramedullary Rod Fixation in a Canine Femoral Gap Model
Authors: Bonin Glen A. , Baker Sean T. , Davis Caleb A. , Bergerson Christie M. , Hildebrandt Aubrey A. , Hulse Don A. , Kerwin Sharon C. , Moreno Michael R. , Saunders W. Brian
Published: January 2014

Objective

To compare the biomechanical properties of clamp rod internal fixation (CRIF)/rod and LC‐DCP/rod constructs in a canine femoral gap model.

Study Design

Cadaveric biomechanical study.

Sample Population

Canine femora (n = 10 pair).

Methods

Femora with 40 mm ostectomies were assigned to LC‐DCP/rod or CRIF/rod treatment groups. Five construct pairs had 4‐point bending and 5 pairs had torsional loading. Construct stiffness, strength, and bending angle at failure or permanent angular deformation (torsional loading) were determined. Statistical comparisons were performed using Student t tests; significance was set at P ≤ .05.

Results

There was significantly greater permanent angular deformation, or residual twist, in the CRIF/rod constructs (23.1 ± 0.89°) compared with LC‐DCP/rod constructs (7.47 ± 2.08°). Whereas there was no significant difference in torsional stiffness of these constructs at torsional loads <4.92 N m (P = .819), LC‐DCP/rod constructs had significantly greater torsional stiffness (0.303 ± 0.079 N m/°) and strength (11.546 ± 2.79 N m) than CRIF/rod construct stiffness (0.06 ± 0.013 N m/°) and strength (6.078 ± 0.527 N m) at torsional loads >4.92 N m. Differences in stiffness and strength in 4‐point bending were not statistically significant.

Conclusions

LC‐DCP/rod constructs had significantly less permanent angular deformation than CRIF/rod constructs. CRIF/rod constructs became less stiff as torsional load was increased, thus the LC‐DCP/rod constructs had significantly greater torsional stiffness and strength under high torsional loads. LC‐DCP/rod and CRIF/rod constructs performed similarly under 4‐point bend loading conditions.
Autologous Platelet Gel to Treat Chronic Decubital Ulcers: A Randomized, Blind Controlled Clinical Trial in Dogs
Authors: Tambella Adolfo Maria , Attili Anna Rita , Dini Fabrizio , Palumbo Piccionello Angela , Vullo Cecilia , Serri Evelina , Scrollavezza Paolo , Dupré Gilles
Published: January 2014

Objective

To determine the efficacy of topical application of the autologous platelet gel (PG) in canine chronic protracted decubital ulcers.

Study Design

Prospective, randomized, blind controlled clinical trial.

Animals

Dogs (n = 18) with bilateral chronic wounds caused by protracted decubitus ulcers.

Methods

For each dog, wound side was randomized to receive either platelet gel (group PG) every 5 days for 5 dressing changes, or paraffin gauzes dressings (group C), as negative control. Wound healing and wound surfaces were compared at admission and then evaluated every 5th day, until day 25. Outcome variables were: open wound area, reduction of open wound surface compared to admission and to each preceding dressing change, time to complete epithelialization.

Results

Significant differences in healing process were observed at day 5 and continued throughout the entire study period (P < .00001). At 25 days, mean percent reduction in wound area was 93.5% in group PG and 13.2% in group C (P < .00001).

Conclusions

Appropriately prepared autologous PG, an inexpensive, readily available blood derivative, applied topically results in more rapid healing of chronic non‐healing decubital ulcers in dogs than those treated by use of paraffin‐impregnated gauzes.
Multicolor Emission in a Single‐Phase Phosphor Ca3Al2O6:Ce3+,Li+: Luminescence and Site Occupancy
Authors: He Yani , Zhang Jilin , Zhou Wenli , Han Jin , Qiu Zhongxian , Yu Liping , Rong Chunying , Lian Shixun
Published: January 2014

A single‐phase multicolor emitting phosphor, Ca3Al2O6:Ce3+,Li+, was prepared by a solid‐state reaction. When the Ce3+ concentration is lower than 0.030 (molar ratio in Ca3Al2O6), yellow and greenish blue emissions can be observed under the excitation by a blue and a near UV light, respectively. The yellow‐emitting phosphor possesses an internal quantum efficiency of 89%. Additional purplish blue emission turns up when Ce3+ concentrations are higher than 0.040. Tunable emission bands are originated from Ce3+ ions on different Ca sites in Ca3Al2O6. Although the emission band of purplish blue or greenish blue overlaps the excitation band of yellow emission, and the distances between the unlike Ce3+ ions are in the range of electric dipole–dipole interaction, no energy transfer is observed. Furthermore, emission wavelengths for the yellow, greenish blue, and purplish blue emission show little change upon increasing Ce3+ concentrations.
Phase Separation in Nonstoichiometry Ge–Sb–S Chalcogenide Glasses
Authors: Li Zhuobin , Lin Changgui , Qu Guoshun , Nie Qiuhua , Xu Tiefeng , Dai Shixun
Published: January 2014

A series of (1 − x)GeS2.5 – xSb chalcogenide glasses were prepared using the conventional melt‐quenching method. Their microstructure and thermal response were systematically studied. We observe a compositional threshold of x = 0.25 which corresponds to chemical stoichiometric composition in the calorimetric experiments. It is in good accordance with the Raman scattering results and laser‐induced phase transformation behavior. They also indicate that phase separation of Sb‐rich phase exists in the S‐poor samples. Moreover, we got a structural modeling of this phase separation: (1) at x = 0.25, which is chemical stoichiometric composition, the structural motifs are only SbS3 pyramid and GeS4 tetrahedra, and the three‐coordinated SbS3 pyramid is isolated by GeS4 tetrahedra; (2) at x < 0.25, the S–S bonds exist in the glass network due to the excess of S; and (3) at x > 0.25, the excess of Sb break the Ge–S and Sb–S bonds to form Sb(Ge)–Sb Bonds, and the Sb atoms segregate from the backbone to nucleate a separate Sb‐rich phase. This work provides a new way to investigate the phase separation of glass networks and helps us to better understand their related physical properties.
Geographical origins of North American Rhodiola (Crassulaceae) and phylogeography of the western roseroot, Rhodiola integrifolia
Authors: Guest Heidi J. , Allen Geraldine A.
Published: January 2014

Aim

Complex migration histories with repeated range shifts during the Pleistocene characterize many arctic–alpine plants. Identifying these patterns provides insight into the causes of current distributions and possible responses to climate warming. We investigated patterns of genetic variation in North American species of a widespread Northern Hemisphere plant group to test different hypotheses of origin and refugial persistence.

Location

North America.

Methods

We used a phylogeographical approach to investigate the geographical origins of North American Rhodiola, especially the widespread western species R. integrifolia. Populations were sampled over much of the North American range (66 of R. integrifolia, 6 of R. rhodantha and 4 of R. rosea). We performed maximum likelihood phylogenetic analyses on sequences of the nuclear internal transcribed spacer (ITS) region and the plastid trnH–psbA intergenic spacer, and analysed geographical patterns of haplotype distribution and genetic diversity using plastid restriction‐site and sequence data from all populations.

Results

Separate lineages of Rhodiola dispersed into North America via the Bering Strait (R. integrifolia and R. rhodantha) and amphi‐Atlantic regions (R. rosea). Genetic patterns within R. integrifolia indicate southward spread from Beringia, with subsequent persistence in both northern and southern refugia. Rhodiola integrifolia and the regional endemic R. rhodantha show evidence of past hybridization (resulting in chloroplast capture) where their ranges overlap in the southern Rocky Mountains. However, phylogenetic evidence suggests that both species are closely related to Asian taxa and probably migrated independently into North America.

Main conclusions

The current geographical distributions and genetic structure of North American Rhodiola are the result of a complex history including multiple migrations into North America, persistence in multiple refugia during glaciations, and past hybridization. This complexity of processes within one group underscores the diverse history of arctic–alpine plants and the likelihood of divergent responses to changing environments.
Qualitative analysis of the contributions of nutritionists to the development of an online instrument for monitoring the food intake of schoolchildren
Authors: Davies V. F. , Kupek E. , de Assis M. A. , Engel R. , da Costa F. F. , Di Pietro P. F. , Natal S. , Thompson D. , Baranowski T.
Published: January 2014

Background

TheConsumo Alimentar e Atividade Fisica de Escolares(CAAFE) questionnaire is an online research tool that has been developed to enable the self‐report of physical activity and diet by Brazilian schoolchildren aged 7–10 years. Formative research was conducted with nutritionists during the development of the web‐based questionnaire. The suggestions and insights obtained were used to design a tool to monitor schoolchildren's food consumption based on the concept of healthy and unhealthy food indicators. The present study aimed to report the focus group discussions conducted with nutritionists concerning theCAAFEquestionnaire.

Methods

Focus group discussions were conducted using a semi‐structured questionnaire, and these were then analysed thematically.

Results

Twenty‐four nutritionists participated (four focus groups; average per group: six people); the majority (n = 22) had experience with 7–10‐year‐old children. Four themes emerged: (i) healthy and unhealthy food indicators; (ii) suggestions for the online instrument; (iii) potential applications; and (iv) challenges for its construction.

Conclusions

Comments made by nutritionists enabled the construction of an instrument that is able to answer questions related to food consumption in schools and at home.
An auxin‐responsive endogenous peptide regulates root development in Arabidopsis
Authors: Yang Fengxi , Song Yu , Yang Hao , Liu Zhibin , Zhu Genfa , Yang Yi
Published: January 2014

Auxin plays critical roles in root formation and development. The components involved in this process, however, are not well understood. Here, we newly identified a peptide encoding gene, auxin‐responsive endogenous polypeptide 1 (AREP1), which is induced by auxin, and mediates root development in Arabidopsis. Expression of AREP1 was specific to the cotyledon and to root and shoot meristem tissues. Amounts of AREP1 transcripts and AREP1‐green fluorescent protein fusion proteins were elevated in response to indoleacetic acid treatment. Suppression of AREP1 through RNAi silencing resulted in reduction of primary root length, increase of lateral root number, and expansion of adventitious roots, compared to the observations in wild‐type plants in the presence of auxin. By contrast, transgenic plants overexpressing AREP1 showed enhanced growth of the primary root under auxin treatment. Additionally, root morphology, including lateral root number and adventitious roots, differed greatly between transgenic and wild‐type plants. Further analysis indicated that the expression of auxin‐responsive genes, such as IAA3, IAA7, IAA17, GH3.2, GH3.3, and SAUR‐AC1, was significantly higher in AREP1 RNAi plants, and was slightly lower in AREP1 overexpressing plants than in wild‐type plants. These results suggest that the novel endogenous peptide AREP1 plays an important role in the process of auxin‐mediated root development.
Inulavosin and its benzo‐derivatives, melanogenesis inhibitors, target the copper loading mechanism to the active site of tyrosinase
Authors: Fujita Hideaki , Menezes José C. J. M. D. S. , Santos Sérgio M. , Yokota Sadaki , Kamat Shrivallabh P. , Cavaleiro José A. S. , Motokawa Tomonori , Kato Tomomi , Mochizuki Mayu , Fujiwara Toshiyuki , Fujii Yuki , Tanaka Yoshitaka
Published: January 2014

Tyrosinase, a melanosomal membrane protein containing copper, is a key enzyme for melanin synthesis in melanocytes. Inulavosin inhibits melanogenesis by enhancing a degradation of tyrosinase in lysosomes. However, the mechanism by which inulavosin redirects tyrosinase to lysosomes is yet unknown. The analyses of structure–activity relationship of inulavosin and its benzo‐derivatives reveal that the hydroxyl and the methyl groups play a critical role in their inhibitory activity. Intriguingly, the docking studies to tyrosinase suggest that the compounds showing inhibitory activity bind through hydrophobic interactions to the cavity of tyrosinase below which the copper‐binding sites are located. This cavity is proposed to be required for the association with a chaperon that assists in copper loading to tyrosinase in Streptomyces antibioticus. Inulavosin and its benzo‐derivatives may compete with the copper chaperon and result in a lysosomal mistargeting of apo‐tyrosinase that has a conformational defect.
Antioxidative Activities of Algal Keto Carotenoids Acting as Antioxidative Protectants in the Chloroplast
Authors: Dambeck Michael , Sandmann Gerhard
Published: January 2014

Very diverse carotenoid structures exist in the photosynthesis apparatus of different algae. Among them, the keto derivatives are regarded the most antioxidative. Therefore, four different keto carotenoids, peridinin, fucoxanthin, siphonaxanthin and astaxanthin fatty acid monoesters, were isolated and purified from Amphidinium carterae, Phaeodactylum tricornutum, Caulerpa taxifolia and Haematococcus pluvialis, respectively. The carotenoids were assayed as inhibitors of photosensitizer initiated reactions or scavengers of radicals in the early events generating reactive oxygen species as starters for peroxidation and as protectants against the whole reaction chain finally leading to lipid peroxidation. These in vitro studies demonstrated the substantial antioxidative properties as indicated by the IC50 values of all four keto carotenoids with superior protection by astaxanthin fatty acid monoesters which were as effective as free astaxanthin and of peridinin against radicals. As an example, the in vivo relevance of fucoxanthin for protection of photosynthesis from excess light and from peroxidative agents was evaluated with intact cells. Cultures of P. tricornutum with decreased fucoxanthin content generated by inhibitor treatment were exposed to strong light or cumene hydroperoxyde. In each case, oxidation of chlorophyll as marker for damaging of the photosynthesis apparatus was less severe when the fucoxanthin was at maximum level.