bluuebunny/crossref_metadata_2025 huggingface dataset:
Extraction of optical Bloch modes in a photonic-crystal waveguide
Authors: Huisman S. R. , Ctistis G. , Stobbe S. , Herek J. L. , Lodahl P. , Vos W. L. , Pinkse P. W. H.
Published: February 2012

We perform phase-sensitive near-field scanning optical microscopy on photonic-crystal waveguides. The observed intricate field patterns are analyzed by spatial Fourier transformations, revealing several guided transverse electric (TE) and transverse magnetic (TM) like modes. Using the reconstruction algorithm proposed by Ha et al. [Opt. Lett. 34, 3776 (2009)], we decompose the measured two-dimensional field pattern in a superposition of propagating Bloch modes. This opens new possibilities to study specific modes in near-field measurements. We apply the method to study the transverse behavior of a guided TE-like mode, where the mode extends deeper in the surrounding photonic crystal when the band edge is approached.
Surface diffusion and layer morphology of ((112¯2)) GaN grown by metal-organic vapor phase epitaxy
Authors: Ploch Simon , Wernicke Tim , Dinh Duc V. , Pristovsek Markus , Kneissl Michael
Published: February 2012

( 11 2 ¯ 2 ) GaN layers were grown by metal-organic vapor phase epitaxy on (112¯2) bulk GaN substrates and (101¯0) sapphire substrates. The growth temperature was varied between 950 and 1050 °C and the total reactor pressure between 50 and 600 mbar. The growth conditions show a strong impact on the yellow band luminescence properties, while weak impact on the threading dislocation density was observed. The layer morphologies exhibit undulations with two periods along GaN [11¯00] and one period along [112¯3¯]. The different period lengths are connected to anisotropic adatom surface diffusion lengths. Arrow like features on the surface originate from the interference of the undulations along [112¯3¯] and [11¯00].
Spontaneous tunneling and near-infrared-induced interconversion between the amino-hydroxy conformers of cytosine
Authors: Reva Igor , Nowak Maciej J. , Lapinski Leszek , Fausto Rui
Published: February 2012

Spontaneous and near-infrared/infrared (NIR/IR)-induced interconversions between two amino-hydroxy conformers of monomeric cytosine have been investigated for the compound isolated in a low-temperature argon matrix. Combined use of a laser source (which provides narrowband NIR radiation) and a broadband NIR/IR source of excitation light allowed a detailed investigation of mutual conversions of the two conformers in question. The experiments carried out within the current work demonstrated that upon broadband NIR/IR irradiation (with the IR source of FTIR spectrometer) the population ratio of the two amino-hydroxy conformers changes towards a ratio corresponding to a photostationary state. Evolution of the conformer population ratio towards the photostationary ratio occurred independent of the initial ratio of conformers, which could be prepared by a population shift (in favor of one of the forms) induced by narrowband NIR excitation. Moreover, spontaneous tunneling conversion of the higher-energy conformer into a lower-energy form was observed for cytosine isolated in a low-temperature argon matrix kept in the dark. This process is slow and occurs on a time scale of days. The tunneling process, studied for matrix-isolated cytosine, clearly follows a dispersive type of kinetics rather than the classical monoexponential kinetics.
Mechanism for resistive switching in an oxide-based electrochemical metallization memory
Authors: Peng Shanshan , Zhuge Fei , Chen Xinxin , Zhu Xiaojian , Hu Benlin , Pan Liang , Chen Bin , Li Run-Wei
Published: February 2012

A comparison of the asymmetric OFF-state current-voltage characteristics between Cu/ZnO/Pt and Cu/ZnO/Al-doped ZnO (AZO) electrochemical metallization memory (ECM) cells demonstrates that the Cu filament rupture and rejuvenation occur at the ZnO/Pt (or AZO) interface, i.e., the cathodic interface. Therefore, the filament is most likely to have a conical shape, with wider and narrower diameters formed at the anodic and cathodic interfaces, respectively. It is inferred that the filament growth starts at the anode surface and stops at the cathode surface. Our results indicate that oxide-based ECM cells strongly differ from sulfide- and selenide-based ones in the resistive switching mechanism.
Transducer for mechanical impedance testing over a wide frequency range through active feedback
Authors: Wiertlewski Michael , Hayward Vincent
Published: February 2012

We describe a feedback-controlled active mechanical probe which can achieve a very low mechanical impedance, uniformly over a wide frequency range. The feedback produces a state of quasi-resonance which transforms the probe into a source of force used to excite an unknown load, resulting in a precise measurement of the real and imaginary components of the load impedance at any frequency. The instrument is applied to the determination of the mechanical impedance of a fingertip.
Terahertz composite right-left handed transmission-line metamaterial waveguides
Authors: Liu Zhijun , Hon Philip W. C. , Tavallaee Amir A. , Itoh Tatsuo , Williams Benjamin S.
Published: February 2012

We report terahertz metamaterial waveguides based on the concept of composite right/left-handed transmission-lines. The waveguides are implemented in a metal-insulator-metal geometry fabricated with spin-coated Benzocyclobutene and contact photolithography. Angle-resolved reflection spectroscopy shows strong resonant absorption features corresponding to both right-handed and left-handed (backward wave) propagating modes within the leaky-wave bandwidth. Tuning of the waveguide dispersion is achieved by varying the effective lumped element series capacitance. The experimental results are in good agreement with full-wave finite element method simulations as well as an intuitive transmission-line circuit model.
Dynamics near a liquid-liquid phase transition in a non-tetrahedral liquid: The case of gallium
Authors: Cajahuaringa Samuel , de Koning Maurice , Antonelli Alex
Published: February 2012

We use molecular simulation to analyze liquid dynamics in the vicinity of the liquid-liquid phase transition (LLPT) recently discovered in the modified embedded-atom model for elemental gallium. For this purpose we analyze the diffusive behavior in terms of the mean-squared displacement and self-intermediate scattering functions for two systems obtained by cooling the stable liquid through the LLPT at different cooling rates. The results show a pronounced heterogeneity of the dynamics upon the onset of the LLPT. Furthermore, it is found that this heterogeneity is closely correlated to the structural properties of the 9-fold coordinated high-density and 8-fold coordinated low-density liquid forms involved in the transition, showing a mixture of domains with very different diffusion time scales. The dynamics of the low-density liquid is found to be much more sluggish than that of the high-density form. Analysis of the energetics suggests that the origin of this difference is rooted in the fact that the cohesion in the former is significantly stronger than that in the latter.
Density functional theory guided Monte Carlo simulations: Application to melting of Na13
Authors: Bulusu Satya , Fournier René
Published: February 2012

We present a density functional theory (DFT) based Monte Carlo simulation method in which a simple energy function gets fitted on-the-fly to DFT energies and gradients. The fitness of the energy function gets tested periodically using the classical importance function technique [R. Iftimie, D. Salahub, D. Wei, and J. Schofield, J. Chem. Phys. 113, 4852 (2000)]. The function is updated to fit the DFT energies and gradients of the most recent structures visited whenever it fails to achieve a preset accuracy. In this way, we effectively break down the problem of fitting the entire potential energy surface (PES) into many easier problems, which are to fit small local regions of the PES. We used the scaled Morse potential empirical function to guide a DFT Monte Carlo simulation of Na13 at various temperatures. The use of empirical function guide produced a computational speed-up of about 7 in our test system without affecting the quality of the results.
Stability of multi-Jensen mappings in non-Archimedean normed spaces
Authors: Xu Tian Zhou
Published: February 2012

In this paper, we study the stability of the multi-Jensen mappings in non-Archimedean normed spaces. The results improve and extend some recent results.
Delay time in quaternionic quantum mechanics
Authors: De Leo Stefano , Ducati Gisele
Published: February 2012

In looking for quaternionic violations of quantum mechanics, we discuss the delay time for pure quaternionic potentials. Our study shows the energy region which amplifies the difference between quaternionic and complex quantum mechanics.
Dynamics of electrostatic microelectromechanical systems actuators
Authors: Yang Yisong , Zhang Ruifeng , Zhao Le
Published: February 2012

Electrostatic actuators are simple but important switching devices for microelectromechanical systems applications. Due to the difficulties associated with the electrostatic nonlinearity, precise mathematical description is often hard to obtain for the dynamics of these actuators. Here we present two sharp theorems concerning the dynamics of an undamped electrostatic actuator with one-degree of freedom, subject to linear and nonlinear elastic forces, respectively. We prove that both situations are characterized by the onset of one-stagnation-point periodic response below a well-defined pull-in voltage and a finite-time touch-down or collapse of the actuator above this pull-in voltage. In the linear-force situation, the stagnation level, pull-in voltage, and pull-in coordinate of the movable electrode may all be determined explicitly, following the recent work of Leus and Elata based on numerics. Furthermore, in the nonlinear-force situation, the stagnation level, pull-in voltage, and pull-in coordinate may be described completely in terms of the electrostatic and mechanical parameters of the model so that they approach those in the linear-force situation monotonically in the zero nonlinear-force limit.
Code-division multiplexing for x-ray microcalorimeters
Authors: Stiehl G. M. , Doriese W. B. , Fowler J. W. , Hilton G. C. , Irwin K. D. , Reintsema C. D. , Schmidt D. R. , Swetz D. S. , Ullom J. N. , Vale L. R.
Published: February 2012

We demonstrate the code-division multiplexing (CDM) readout of eight transition-edge sensor microcalorimeters. The energy resolution is 3.0 eV (full width at half-maximum) or better at 5.9 keV, with a best resolution of 2.3 eV and a mean of 2.6 eV over the seven modulated detectors. The flux-summing CDM system is described and compared with similar time-division multiplexing (TDM) readout. We show that the Npixels multiplexing disadvantage associated with TDM is not present in CDM. This demonstration establishes CDM as both a simple route to higher performance in existing TDM microcalorimetric experiments and a long-term approach to reaching higher multiplexing factors.
Conduction band structure in wurtzite GaAs nanowires: A resonant Raman scattering study
Authors: Peng Wang , Jabeen F. , Jusserand B. , Harmand J. C. , Bernard M.
Published: February 2012

We report on a room temperature Raman resonance at 1.56 eV in GaAs wurtzite nanowires together with the emergence of a strong forbidden longitudinal optical phonon line. We attribute this resonance, absent in zinc blende wires with similar diameters, to an additional excitonic transition due to conduction band folding in agreement with recent theoretical predictions.
Graphene nanodots with intrinsically magnetic protrusions
Authors: Philpott Michael R. , Kawazoe Yoshiyuki
Published: February 2012

The three step auf bau of a triangular polyaromatic protrusion attached to a larger parent hexagonal shaped graphene nanodot (GND) is described and the dichotomy between intrinsic protrusion localized magnetism and parent extended zigzag edge magnetism is explored using ab initio density functional theory calculations of spin and charge distributions and geometry. Comparison of a three ring with a ten-ring protrusion-GND establishes a pattern for the magnetization of GNDs with larger protrusions and different morphology. The magnetism of the isolated protrusions arises from the mismatch in numbers of sublattice (alternant hydrocarbon) carbon atoms. In the parent, the sublattices are equivalent providing a singlet ground state and the magnetization appears only on long zigzag edges due to exchange interactions operating in a regime of reduced coulombic interactions. We demonstrate that a small protrusion can quench the magnetism of the edge to which it is attached. Concomitantly, the adjacent edges exhibit a small magnetic enhancement, while the remote edges are unperturbed. With size the protrusion can dominate its edge and exert control over the magnetization of other edges. Different multiplicities of the parent moiety were not found. These calculations provide guidance in understanding how the magnetism changes with system shape and in designing nanodots with a specific magnetization.
Smith-chart diagnostics for multi-GHz time-domain-reflectometry dielectric spectroscopy
Authors: Hager N. E. , Domszy R. C. , Tofighi M. R.
Published: February 2012

A time-domain-reflectometry Smith-chart display is demonstrated to be a valuable diagnostic tool in a variety of situations in time-domain-reflectometry dielectric spectroscopy. A relative reflection coefficient is formed by dividing the Laplace transform of the reflected sample transient by the Laplace transform of the empty-sensor transient and displaying in the complex plane, with the approximate sensor admittance read from susceptance and conductance circles. The Smith chart provides, as a diagnostic tool, an initial estimate of the dielectric behavior in the multi-GHz range and a means of identifying artifacts in acquisition and Laplace transform, in a way which does not require multiple steps of calibration and is only one step removed from the direct transient. Results are presented for a simple 3.5-mm flat sensor immersed in various liquid media, showing variations in the Smith chart for typical variations in sample permittivity, loss, and conductivity. Results are matched to vector network analyzer (VNA) measurement over an identical frequency range, as well as to finite-element field simulation. Results are also presented for a 3.5-mm sensor with various terminating pin lengths, typically employed at low frequencies and low permittivity media to increase sensor capacitance. For an unshielded pin, the Smith chart detects reflections from sample boundaries and measures the effectiveness of shielding used to eliminate these reflections. For a shielded pin, it characterizes the effect of pin length on the susceptance variation and the onset of pin resonance at high frequencies and high-permittivity values. The effect of artifacts appearing in the Smith chart on the actual calibration is shown by tracking them through the calibration process to the final result. Results are also presented for a 9-mm flat termination used for concrete hydration monitoring, showing effects of transmission-line discontinuities within a terminating plug and the onset of waveguide-like modes in a surrounding shield, with results compared to VNA measurement.
Quasimonoenergetic electron beams from laser wakefield acceleration in pure nitrogen
Authors: Mo M. Z. , Ali A. , Fourmaux S. , Lassonde P. , Kieffer J. C. , Fedosejevs R.
Published: February 2012

Quasimonoenergetic electron beams with maximum energy >0.5 GeV and 2 mrad divergence have been generated in pure nitrogen gas via wakefield acceleration with 80 TW, 30 fs laser pulses. Long low energy tail features were typically observed due to continuous ionization injection. The measured peak electron energy decreased with the plasma density, agreeing with the predicted scaling for electrons. The experiments showed a threshold electron density of 3×1018cm-3 for self-trapping. Our experiments suggest that pure Nitrogen is a potential candidate gas to achieve GeV monoenergetic electrons using the ionization induced injection scheme for laser wakefield acceleration.
Slip boundary for fluid flow at rough solid surfaces
Authors: Chen Yongping , Zhang Chengbin , Shi Mingheng , Peterson George P.
Published: February 2012

A molecular dynamics simulation of slip boundary for fluid flow past a solid surface incorporating roughness effect as characterized by fractal geometry has been conducted with a focus on the origin of slip, fluid structure, and slip boundary flow. The results indicate that interfacial slip develops provided that the wall is effectively uncorrugated. Compared with the atomically smooth surface, extra viscous dissipation is induced for shear flow past a rough surface and leading to a reduction in boundary slip. In particular, we find that a more irregular topography decreases the boundary slip even for the same statistical roughness height.
Hysteresis losses in a dense superparamagnetic nanoparticle assembly
Authors: Gudoshnikov S. A. , Liubimov B. Ya. , Usov N. A.
Published: February 2012

The hysteresis losses of a dense assembly of magnetite nanoparticles with an average diameter D = 25 nm are measured in the frequency range f = 10 – 200 kHz for magnetic field amplitudes up to H0 = 400 Oe. The low frequency hysteresis loops of the assembly are obtained by means of integration of the electro-motive force signal arising in a small pick-up coil wrapped around a sample which contains 1 – 5 mg of a magnetite powder. It is proved experimentally that the specific absorption rate diminishes approximately 4.5 times when the sample aspect ratio decreases from 11.4 to 1. Theoretical estimate shows that experimentally measured hysteresis loops can be approximately described only by taking into account appreciable contributions of magnetic nanoparticles of both very small, D < 10 – 12 nm, and rather large, D > 30 nm, diameters. Thus the wide particle size distribution has to be assumed.
Estimates of variances due to parent of origin effects for weights of Australian beef cattle
Authors: Meyer Karin , Tier Bruce
Published: February 2012

Estimates of variances due to differential expression of paternally and maternally derived genes can be obtained from animal model type analyses by fitting appropriate gametic effects. This is feasible for large-scale analyses, because the inverse of the gametic relationship matrix can be set up directly from a list of pedigrees. We present a series of analyses applying such a model to large sets of records for birth, weaning, yearling and final weights of Australian Angus and Hereford cattle. On one hand, results show that maternal genetic effects on these traits are largely confounded with maternal parent of origin effects, so that it is difficult to reliably separate the respective variance components. On the other hand, paternal parent of origin effects tend to act similarly to sire × herd effects so that estimates of their variance are inflated by any effects not modelled and contributing to such apparent interaction. Fitting an animal model with both parent of offspring effects, maternal genetic and permanent environmental effects as well as sire × herd and maternal grand-sire × herd of origin of dam interactions as additional random effects yielded estimates of the variance due to paternal parent of origin effects of 5–7% of the phenotypic variation for birth and weaning weights and of 0–1% for yearling and final weights. Corresponding estimates for maternal parent of origin effects were 0–11% for birth and weaning weights and 7–8% for yearling and final weights, while sire and maternal grand-sire interaction effects explained from 0 to 4% of the phenotypic variance.
Gel–water partitioning of soil humics in diffusive gradient in thin film (DGT) analysis of their metal complexes
Authors: van der Veeken Pascal L. R. , van Leeuwen Herman P.
Published: February 2012

Environmental contextMetal species can have significant toxic effects in aquatic systems, and therefore their occurrence should be reliably monitored. Although many methods to measure metal species are available, they all have limitations and are sensitive to physicochemical complications. It is shown that, in techniques based on diffusive gradients in thin films, sorption of humic acids affects metal speciation inside the diffusive gel layer and the nature of the ensuing flux response. AbstractMetal complexes of humic and fulvic acids are ubiquitous in aqueous environmental media. In metal speciation analysis by DGT (diffusive gradient in thin film) with polyacrylamide hydrogels, soil humic acid species have been shown to significantly accumulate in the diffusive gel layer. As a result, the speciation of their metal complexes inside the gel is changed with respect to that in the sample medium. In low ionic strength samples, the effects of sorption of the charged humic species are compounded by Donnan partitioning. Here we lay out the basic features that govern the partition of humic species between gel and water, and discuss their effect on the properties of the DGT metal flux.
Immunotherapy earns its spot in the ranks of cancer therapy
Authors: Pardoll Drew , Drake Charles
Published: February 2012

Since it became clear that all cancer cells express tumor-specific and tumor-selective antigens generated by genetic alterations and epigenetic dysregulation, the immunology community has embraced the possibility of designing therapies to induce targeted antitumor immune responses. The potential therapeutic specificity and efficacy of such treatments are obvious to anyone who studies the exquisite specificity and cytocidal potency of immune responses. However, the value assigned to a therapeutic modality by the oncology community at large does not depend on scientific principle; all that matters is how patients respond. The bar for the ultimate acceptance of a therapy requires more than anecdotal clinical responses; rather, the major modalities of cancer therapeutics, including surgery, chemotherapy, radiation therapy, and, more recently, drugs targeting oncogenes, have earned their place only after producing dramatic frequent clinical responses or demonstrating statistically significant survival benefits in large randomized phase 3 clinical trials, leading to FDA approval. Although tumor-targeted antibodies have certainly cleared this bar, immunotherapies aimed at harnessing antitumor cellular responses have not—until now.
Targeting glucose metabolism for cancer therapy
Authors: Hamanaka Robert B. , Chandel Navdeep S.
Published: February 2012

Cellular transformation is associated with the reprogramming of cellular pathways that control proliferation, survival, and metabolism. Among the metabolic changes exhibited by tumor cells is an increase in glucose metabolism and glucose dependence. It has been hypothesized that targeting glucose metabolism may provide a selective mechanism by which to kill cancer cells. In this minireview, we discuss the benefits that high levels of glycolysis provide for tumor cells, as well as several key enzymes required by cancer cells to maintain this high level of glucose metabolism. It is anticipated that understanding which metabolic enzymes are particularly critical for tumor cell proliferation and survival will identify novel therapeutic targets.
Review article: coeliac disease, new approaches to therapy
Authors: Rashtak S. , Murray J. A.
Published: February 2012

Background

Coeliac disease is managed by life‐long gluten withdrawal from the diet. However, strict adherence to a gluten‐free diet is difficult and is not always effective. Novel therapeutic approaches are needed to supplement or even replace the dietary treatment.

Aim

To review recent advances in new therapeutic options for coeliac disease.

Methods

A literature search was performed on MEDLINE, EMBASE, Web of Science, Scopus, DDW.org and ClinicalTrials.gov for English articles and abstracts. The search terms used included, but not limited to, ‘Celiac disease’, ‘new’, ‘novel’, ‘Advances’, ‘alternatives’ and ‘Drug therapy’. The cited articles were selected based on the relevancy to the review objective.

Results

Several new therapeutic approaches for coeliac disease are currently under development by targeting its underlying pathogenesis. Alternative therapies range from reproduction of harmless wheat strains to immunomodulatory approaches. Some of these therapies such as enzymatic cleavage of gluten and permeability inhibitors have shown promise in clinical studies.

Conclusions

Gluten‐free diet is still the only practical treatment for patients with coeliac disease. Novel strategies provide promise of alternative adjunctive approaches to diet restriction alone for patients with this disorder.
Randomised clinical trial: efficacy of a new synbiotic formulation containing Lactobacillus paracasei B21060 plus arabinogalactan and xilooligosaccharides in children with acute diarrhoea
Authors: Passariello A. , Terrin G. , Cecere G. , Micillo M. , De Marco G. , Di Costanzo M. , Cosenza L. , Leone L. , Nocerino R. , Berni Canani R.
Published: February 2012

Background

Acute diarrhoea is a frequent problem in children with heavy economic burden for families and society.

Aim

To test the efficacy of a new synbiotic formulation containing Lactobacillus paracasei B21060, arabinogalactan and xilooligosaccharides in children with acute diarrhoea.

Methods

Double‐blind, randomised, placebo‐controlled trial, including children (age 3–36 m) with acute diarrhoea who were allocated to placebo or synbiotic group. Major outcome was resolution rate of diarrhoea at 72 h. Total duration of diarrhoea, daily stool outputs, stool consistency, working days lost by parents, adjunctive medications, and hospitalisation were also assessed.

Results

We enrolled 55 children in placebo group and 52 in synbiotic group. The two groups were similar for demographic and clinical characteristics. Resolution rate of diarrhoea at 72 h was significantly higher in synbiotic group (67%) compared to placebo group (40%, P = 0.005). Children in synbiotic group showed a significant reduction in the duration of diarrhoea (90.5 h, 78.1–102.9 vs. 109.8 h, 96.0–123.5, P = 0.040), daily stool outputs (3.3, 2.8–3.8 vs. 2.4, 1.9–2.8, P = 0.005) and stool consistency (1.3, 0.9–1.6 vs. 0.6, 0.4–0.9, P = 0.002) compared to placebo group (data expressed as mean, 95% CI). Rate of parents that missed at least one working day (41.8% vs. 15.4%, P = 0.003), rate of children that needed adjunctive medications (25.5% vs. 5.8%, P = 0.005) or hospitalisation (10.9% vs. 0%, P = 0.014) after the first 72 h of treatment, were reduced in synbiotic group.

Conclusion

The synbiotic formulation studied is effective in children with acute diarrhoea. Australian New Zealand Clinical Trials Registry (ACTRN12611000641998).
Comprehensive investigation of genetic variation in the 8q24 region and multiple myeloma risk in the IMMEnSE consortium
Authors: Campa Daniele , Martino Alessandro , Sainz Juan , Buda Gabriele , Jamroziak Krzysztof , Weinhold Niels , Reis Rui Manuel Vieira , García‐Sanz Ramón , Jurado Manuel , Ríos Rafael , Szemraj‐Rogucka Zofia , Marques Herlander , Lesueur Fabienne , Bugert Peter , Moreno Victor , Szemraj Janusz , Orciuolo Enrico , Gemignani Federica , Rossi Anna Maria , Dumontet Charles , Petrini Mario , Goldschmidt Hartmut , Landi Stefano , Canzian Federico
Published: February 2012

Genome‐wide association studies (GWAS) have shown that the 8q24 region harbours multiple independent cancer susceptibility loci, even though it is devoid of genes. Given that no GWAS data are currently available for multiple myeloma (MM), we tested the hypothesis that genetic variants in this region could play a role in MM risk. We genotyped 20 single nucleotide polymorphisms of 8q24 in 1188 MM cases and 2465 controls and found a statistically significant (P = 0·0022) association between rs2456449 and MM risk. These data provide further evidence that the genetic variability in the 8q24 region is associated with cancer risk, particularly haematological malignancies.
S‐phase fraction and ploidy as predictive markers in primary disease and recurrence of papillary thyroid carcinoma
Authors: Pinto António E. , Silva Giovani L. , Pereira Teresa , Cabrera Rafael A. , Santos Jorge Rosa , Leite Valeriano
Published: February 2012

Objective

To investigate the prognostic influence of DNA ploidy and S‐phase fraction (SPF) on disease‐free (DFS) and overall survival (OS) of patients with primary disease and loco‐regional lymph node recurrence of papillary thyroid carcinoma (PTC).

Design

A large prospective study with long‐term follow‐up (median, 117 months).

Patients

Two series of patients with primary PTC (n = 305) and lymph node recurrence metastasis (LNM) (n = 39) were involved in the study.

Measurements

Patient's age and gender, histological variant, pathological tumour‐node‐metastasis (pTNM) staging, extrathyroidal extension, vascular and lymphatic invasion and tumour bilateral growth were the clinical and pathological characteristics evaluated. DNA flow cytometry was performed on fresh/frozen surgical tumour samples. Cox regression models were estimated for prognostic analyses.

Results

Seventeen (5·6%) primary tumours and five (12·8%) LNMs were aneuploid, while mean SPF was 2·7% and 3·7%, respectively (P = 0·022). High SPF was significantly associated with lymphatic invasion and tall cell and diffuse sclerosing variants. In univariate analysis, all the clinico‐pathological variables, but tumour bilateral growth and gender, were significantly correlated with survival. SPF showed borderline significance (P = 0·051) in relation to OS. In multivariate analysis, older age (≥48 years), lymph node spread and high SPF were significantly adverse prognostic factors. Extrathyroidal extension and distant metastasis for OS, as well as tumour size for DFS, were also found as unfavourable prognostic features. In LNM, the Kaplan–Meier curves showed significant differences for older age and DNA aneuploidy (recurrence; P = 0·011).

Conclusion

The results indicate that SPF and ploidy can provide additional predictive information in patients with PTC.
The effectiveness of the continuous underway fish egg sampler compared with standard vertical plankton hauls for sampling the eggs of demersal species in the southern North Sea
Authors: LELIEVRE S. , VAZ S. , FOX C.
Published: February 2012

To date, the continuous underway fish egg sampler (CUFES) has been used primarily to map the spawning areas of pelagic fish in upwelling regions. To assess its utility in mapping the spawning grounds of demersal species, species composition and densities of eggs collected by CUFES were compared with results obtained from ring‐net samples (VET: vertical egg trawl) from the southern North Sea over three annual cruises conducted in January/February. CUFES collected slightly fewer eggs per unit volume of water filtered when compared with vertically integrated samples but maps of egg distributions from both devices showed broadly similar patterns. Geostatistical analyses revealed that small‐scale variability was greater with CUFES than with VET. CUFES may thus be able to resolve finer spatial structuring of egg distributions. At the sampling station scale, species compositions (in terms of proportion and abundance) from both approaches were similar, with the notable exception of flounder, which was much more abundant in CUFES samples; these results were similar when considering early and older stage eggs. Results from regression modelling showed that it was difficult to estimate total egg abundance in the water column from CUFES data with linear regression techniques even when additional factors which affect the vertical distribution of the eggs, such as depth, bedstress and wind‐induced mixing, were included. CUFES therefore provides a suitable method for mapping egg distributions of the main fish species producing planktonic eggs during the winter and early spring season in the southern North Sea but may not be used easily when absolute measures of egg production are required. However, CUFES can be added to standard trawl surveys with little disruption to the baseline ground‐fish survey.
A 3D simultaneous source field test processed using alternating projections: a new active separation method
Authors: Beasley Craig J. , Dragoset Bill , Salama Antoun
Published: February 2012

In 2008, a wide azimuth simultaneous source (SimSrc) 3D data set was acquired over an area coinciding with an existing conventional wide azimuth survey. Using two (nearly) simultaneous sources provided twice the number of shots, an increased shot density and twice the fold for essentially the same acquisition time. Although the improved sampling for the SimSrc data was predicted to yield improvements in processes such as 3D multiple attenuation and migration, cross‐talk between the sources was a concern. Cross‐talk can be suppressed by known techniques such as separation algorithms that estimate the individual shots and thereby separate SimSrc records into their constituent shots. However, separation algorithms available at the time suffered from aliasing and were not effective for severely shot‐aliased data such as those encountered in the experimental data set, which had a 75‐m in‐line shot spacing, half that typical for wide azimuth geometries.

In this paper we present a new separation technique called the Alternating Projection Method (APM), which is demonstrated to be robust in the presence of aliasing. Through comparisons with conventional wide azimuth data we show that 3D multiple removal and migration are both aided by the increase in shots. Moreover, the high quality of the APM separated data indicates that prestack products such as migration angle gathers will have better quality than was achieved a few years ago using a passive separation approach. We found that by carefully selecting and tailoring the method's projection operators, excellent separation results can be achieved efficiently.
Diagnosis of the condition of the dental pulp: a systematic review
Authors: Mejàre I. A. , Axelsson S. , Davidson T. , Frisk F. , Hakeberg M. , Kvist T. , Norlund A. , Petersson A. , Portenier I. , Sandberg H. , Tranæus S. , Bergenholtz G.
Published: February 2012

Mejàre IA, Axelsson S, Davidson T, Frisk F, Hakeberg M, Kvist T, Norlund A, Petersson A, Portenier I, Sandberg H, Tranæus S, Bergenholtz G. Diagnosis of the condition of the dental pulp: a systematic review. International Endodontic Journal, 45, 597–613, 2012.

The aim of this systematic review was to appraise the diagnostic accuracy of signs/symptoms and tests used to determine the condition of the pulp in teeth affected by deep caries, trauma or other types of injury. Radiographic methods were not included. The electronic literature search included the databases PubMed, EMBASE, The Cochrane Central Register of Controlled Trials and Cochrane Reviews from January 1950 to June 2011. The complete search strategy is given in an Appendix S1 (available online as Supporting Information). In addition, hand searches were made. Two reviewers independently assessed abstracts and full‐text articles. An article was read in full text if at least one of the two reviewers considered an abstract to be potentially relevant. Altogether, 155 articles were read in full text. Of these, 18 studies fulfilled pre‐specified inclusion criteria. The quality of included articles was assessed using the QUADAS tool. Based on studies of high or moderate quality, the quality of evidence of each diagnostic method/test was rated in four levels according to GRADE. No study reached high quality; two were of moderate quality. The overall evidence was insufficient to assess the value of toothache or abnormal reaction to heat/cold stimulation for determining the pulp condition. The same applies to methods for establishing pulp status, including electric or thermal pulp testing, or methods for measuring pulpal blood circulation. In general, there are major shortcomings in the design, conduct and reporting of studies in this domain of dental research.
Reproductive allometry in Pedicularis species changes with elevation
Authors: Guo Hui , Weiner Jacob , Mazer Susan J. , Zhao Zhigang , Du Guozhen , Li Bo
Published: February 2012

1. Plants produce biomass and then allocate some of it to reproductive structures, so the relationship between reproductive (R) and vegetative (V) mass is a fundamental aspect of a plant’s reproductive strategy.

2. Differences among populations or taxa in the allometric relationship between R and V have been attributed to environmental conditions. We hypothesize that populations and taxa living at high elevations should exhibit a lower log R vs. log V slope than those in more benign environments, because the environmental limits on size in alpine environments should favour a relatively large reproductive allocation at smaller sizes and a smaller investment in reproduction per additional unit of biomass accumulated.

3. We investigated variation in the allometric relationship between R and V among 44 naturally occurring populations representing 24 species of Pedicularis in the Tibetan Plateau, to test the hypothesis that the slope of the relationship declines with increasing elevation.

4. There was a significant negative relationship between the slope of the log R vs. log V relationship and elevation among populations, although the relationship among populations within species varied. We interpret this in terms of abiotic limitations on size and decreasing efficiency of resource allocation to reproduction with increasing plant size (measured as vegetative biomass) at high elevations. We also found a significant positive relationship between the y‐intercept of the regression of log R on log V and elevation across species, but the relationship was not significant among populations within species. The combination of the lower slopes and the higher y‐intercepts for high‐elevation populations means that plants growing at high elevations allocate proportionately more biomass to reproduction at smaller sizes and less at larger sizes than plants growing at lower elevations.

5. Synthesis. The allometric slope (exponent) of the R–V relationship decreases with increasing elevation among Pedicularis populations and species, reflecting fundamental changes in the costs and benefits of increased vegetative biomass with elevation.
Biological Flora of the British Isles: Rosa spinosissima L.
Authors: Mayland‐Quellhorst Eike , Föller Jens , Wissemann Volker
Published: February 2012

1. This account presents information on all aspects of the biology of Rosa spinosissima L. (R. pimpinellifolia L.) that are relevant to understanding its ecological characteristics and behaviour. The main topics are presented within the standard framework of the Biological Flora of the British Isles: distribution, habitat, communities, responses to biotic factors, responses to environment, structure and physiology, phenology, floral and seed characters, herbivores and disease, history, and conservation.

2. Rosa spinosissima is a small, deciduous shrub forming clonal patches from root suckers. In Britain it is common on stabilized coastal dunes, more or less base‐rich heaths, and on open, dry habitats on chalk or limestone inland. It is naturally distributed across temperate Europe and western and central Asia.

3. The small leaves and leaflets, in combination with many straight or slightly curved bristles and prickles, and the black hips, make R. spinosissima easily recognizable in Britain. It normally does not exceed 10–40 cm but cultivars often grow taller.

4. The seeds are dispersed by birds and other animals, particularly as the hips are a favoured diet of birds, because of the high vitamin and anthocyanin content. Vegetative spread is frequent through the root suckers.

5. Cultivars are commonly planted for amenity and in gardens. The origin of the cultivars is not known, but genetic exchange of these with natural British populations may lead to introgression with genotypes which are not locally adapted. The invasive Rosa rugosa may be a threat in some coastal habitats as this species is displacing R. spinosissima on the German North Sea coast.
Bacterial host interaction of GFP‐labelled Vibrio anguillarum HI‐610 with gnotobiotic sea bass, Dicentrarchus labrax (L.), larvae
Authors: Rekecki A , Gunasekara R A Y S A , Dierckens K , Laureau S , Boon N , Favoreel H , Cornelissen M , Sorgeloos P , Ducatelle R , Bossier P , Van den Broeck W
Published: February 2012

The location and cell damage caused by Vibrio anguillarum, the causative agent of classical vibriosis, within the developing gut of the newly hatched sea bass, Dicentrarchus labrax (L.), is unknown. A gnotobiotic sea bass model was used to investigate the early interactions of V. anguillarum with sea bass larvae. In the present study, germ‐free sea bass larvae were orally exposed to a V. anguillarum HI‐610 pathogen labelled with the green fluorescent protein (GFP‐HI‐610) and sampled at regular intervals. Pathogenic colonization of gut enterocytes was observed 2 h post‐exposure (p.e.) and onwards, whereas bacteria within the swim bladder were visualized 48 h p.e and onwards. Ultrastructural findings demonstrated direct bacterial contact with the host cell in the oesophageal mucosa and putative attachment to microvilli of mid‐ and hindgut enterocytes. The present findings form a starting point for studies assessing the impact of potential candidates (probiotics, prebiotics, antimicrobial peptides) to mitigate bacterial virulence.
Innate immune dysfunction in inflammatory bowel disease
Authors: Gersemann M. , Wehkamp J. , Stange E. F.
Published: February 2012

Abstract.  Gersemann M, Wehkamp J, Stange EF (Robert Bosch Hospital, Stuttgart; Dr. Margarete Fischer‐Bosch Institute of Clinical Pharmacology, Stuttgart and University of Tübingen, Tübingen; Germany). Innate immune dysfunction in inflammatory bowel disease (Review). J Intern Med 2012; 271: 421–428.

The pathogenetic mechanisms that cause the two types of inflammatory bowel disease (IBD), Crohn’s disease (CD) and ulcerative colitis (UC), are still under investigation. Nevertheless, there is broad agreement that luminal microbes are of particular relevance in the development of these conditions. In recent years, increasing evidence has shown that defects in the innate immunity are at the centre of both types of IBD. The innate intestinal barrier is provided by the epithelium which secretes antimicrobial peptides (so‐called defensins) that are retained in the mucus layer. In ileal CD, the alpha‐defensins are lacking owing to several Paneth cell defects. In colonic CD, the expression of beta‐defensins is inadequate. This may be related to downregulation of the transcription factor peroxisome proliferator‐activated receptor‐gamma and in some cohorts is associated with a reduced HBD2 gene copy number. In UC, the mucus layer, which protects the host from the enormous amounts of luminal microbes, is defective. This is accompanied by an insufficient differentiation from intestinal stem cells towards goblet cells. All these disturbances in the gut barrier shift the balance from epithelial defence towards bacterial offence. The current treatment for CD and UC is based on suppression of this secondary inflammatory process. In future, patients may benefit from new therapeutic approaches stimulating the protective innate immune system.
The COP9 signalosome counteracts the accumulation of cullin SCF ubiquitin E3 RING ligases during fungal development
Authors: von Zeska Kress Marcia Regina , Harting Rebekka , Bayram Özgür , Christmann Martin , Irmer Henriette , Valerius Oliver , Schinke Josua , Goldman Gustavo H. , Braus Gerhard H.
Published: February 2012

Defects in the COP9 signalosome (CSN) impair multicellular development, including embryonic plant or animal death or a block in sexual development of the fungus Aspergillus nidulans. CSN deneddylates cullin‐RING ligases (CRLs), which are activated by covalent linkage to ubiquitin‐like NEDD8. Deneddylation allows CRL disassembly for subsequent reassembly. An attractive hypothesis is a consecutive order of CRLs for development, which demands repeated cycles of neddylation and deneddylation for reassembling CRLs. Interruption of these cycles could explain developmental blocks caused by csn mutations. This predicts an accumulation of neddylated CRLs exhibiting developmental functions when CSN is dysfunctional. We tested this hypothesis in A. nidulans, which tolerates reduced levels of neddylation for growth. We show that only genes for CRL subunits or neddylation are essential, whereas CSN is primarily required for development. We used functional tagged NEDD8, recruiting all three fungal cullins. Cullins are associated with the CSN1/CsnA subunit when deneddylation is defective. Two CRLs were identified which are specifically involved in differentiation and accumulate during the developmental block. This suggests that an active CSN complex is required to counteract the accumulation of specific CRLs during development.
Prediction of early hepatic artery thrombosis by intraoperative color Doppler ultrasound in pediatric segmental liver transplantation
Authors: Gu Li H. , Fang Hua , Li Feng H. , Li Ping , Zhu Cai X. , Zhu Jian J. , Zhang Shi J.
Published: February 2012

Gu LH, Fang H, Li FH, Li P, Zhu CX, Zhu JJ, Zhang SJ. Prediction of early hepatic artery thrombosis by intraoperative color Doppler ultrasound in pediatric segmental liver transplantation.

Abstract:  Early hepatic artery thrombosis (eHAT) after transplantation is associated with a high incidence of graft failure and mortality in pediatric segmental liver transplantation (LT). The evaluation of intraoperative color Doppler ultrasound (CD‐US) parameters and their sensitivity and specificity for the prediction of eHAT were important. Pediatric segmental LTs were performed in 49 consecutive patients from October 2006 to December 2010 in our hospital. A total of seven patients (14.3%) experienced eHAT (within one month) after LT. The intraoperative hepatic artery (HA) diameter (p = 0.026), hepatic arterial peak systolic velocity (HAPSV) (p = 0.006), and hepatic artery resistance index (HARI) (p = 0.000) had significant difference between eHAT group and non‐eHAT group. Taking a HA diameter <2 mm, a HAPSV of <40 cm/s and a HARI of <0.6 as threshold to predict eHAT, the sensitivity and specificity were 85.7%, 85.7%, 85.7%, and 61.9%, 76.2%, 88.1%, respectively. A HARI of <0.6 was shown to be the most sensitive and specific single parameter for predicting eHAT.