bluuebunny/crossref_metadata_2025 huggingface dataset:
A quantitative study on growth variability and production of ochratoxin A and its derivatives by A. carbonarius and A. niger in grape-based medium
Authors: Freire Luísa , Guerreiro Tatiane M. , Pia Arthur K. R. , Lima Estela O. , Oliveira Diogo N. , Melo Carlos F. O. R. , Catharino Rodrigo R. , Sant’Ana Anderson S.
Published: September 2018

Aspergillus carbonarius and Aspergillus niger are the main responsible fungi for the accumulation of ochratoxin A (OTA) in wine grapes. Some strains are able to convert the parent mycotoxin into other compounds by means of hydrolysis and/or conjugation reactions through their defense mechanisms and enzymatic activity, leading to the formation of a modified mycotoxin. Thus, the variability of growth and metabolite production are inherent to the strain, occurring distinctively even when submitted to similar conditions. In this sense, this contribution aimed at determining the variability in multiplication and production of OTA by strains of A. carbonarius and A. niger isolated from grapes, as well as investigating the formation of modified mycotoxins. Strains were incubated in grape-based medium, and the diameter of the colonies measured daily. The determination of OTA was performed by high-performance liquid chromatography and the identification of modified mycotoxins was carried out using high-resolution mass spectrometry. Variabilities in terms of growth and OTA production were assessed across five different strains. Peak production of OTA was detected on day 15, and a decline on day 21 was observed, indicating that the observed reduction may be associated with the degradation or modification of the OTA over time by the fungus. Ethylamide ochratoxin A, a modified mycotoxin identified in this study, provides evidence that there may be underreporting of total mycotoxin levels in food, increasing uncertainty concerning health risks to the population.
Reference data on thickness and mechanics of tissue layers and anthropometry of musculoskeletal extremities
Authors: Neumann Erica E. , Owings Tammy M. , Schimmoeller Tyler , Nagle Tara F. , Colbrunn Robb W. , Landis Benjamin , Jelovsek J. Eric , Wong Mike , Ku Joy P. , Erdemir Ahmet
Published: September 2018

Musculoskeletal extremities exhibit a multi-layer tissue structure that is composed of skin, fat, and muscle. Body composition and anthropometric measurements have been used to assess health status and build anatomically accurate biomechanical models of the limbs. However, comprehensive datasets inclusive of regional tissue anatomy and response under mechanical manipulation are missing. The goal of this study was to acquire and disseminate anatomical and mechanical data collected on extremities of the general population. An ultrasound system, instrumented with a load transducer, was used for in vivo characterization of skin, fat, and muscle thicknesses in the extremities of 100 subjects at unloaded (minimal force) and loaded (through indentation) states. For each subject, the unloaded and loaded state provided anatomic tissue layer measures and tissue indentation response for 48 and 8 regions, respectively. A publicly available web-based system has been used for data management and dissemination. This comprehensive database will provide the foundation for comparative studies in regional musculoskeletal composition and improve visual and haptic realism for computational models of the limbs.
How to unravel the chemical structure and component localization of individual drug-loaded polymeric nanoparticles by using tapping AFM-IR
Authors: Mathurin Jérémie , Pancani Elisabetta , Deniset-Besseau Ariane , Kjoller Kevin , Prater Craig B. , Gref Ruxandra , Dazzi Alexandre
Published: September 2018

We describe here the theoretical basis of the innovative tapping AFM-IR mode that can address novel challenges in imaging and chemical mapping of polymeric nanoparticles.
A ratiometric fluorescent BODIPY-based probe for rapid and highly sensitive detection of cysteine in human plasma
Authors: Wang Nannan , Wang Yue , Gao Jinhua , Ji Xin , He Jinling , Zhang Jian , Zhao Weili
Published: September 2018

The probe could respond to Cys/Hcy, exhibiting a ratiometric fluorescence response through intramolecular displacement with the amino group displacing the sulfur function to form amino-substituted BODIPY.
The electronic structure of f-element Prussian blue analogs determined by soft X-ray absorption spectroscopy
Authors: Dumas Thomas , Guillaumont Dominique , Moisy Philippe , Shuh David K. , Tyliszczak Tolek , Solari Pier Lorenzo , Den Auwer Christophe
Published: September 2018

Isomorphous lanthanides and actinides Prussian blue analogs showing distinct optical and vibrational properties are studied using nitrogen K edge and iron K edge.
Arylation of benzyl amines with aromatic nitriles
Authors: Lei Yingjie , Yang Ju , Qi Rupeng , Wang Shan , Wang Rui , Xu Zhaoqing
Published: September 2018

The C(sp3)–H arylation of benzyl amines with aromatic nitriles for the synthesis of diarylmethylamines was realized without the assistance of transition-metal and photoirradiation.
Structural and conformational changes in [M(1,10-diaza-18-crown-6)Cl2] (M = Pd, Pb) complexes: a crystallographic and theoretical study
Authors: Arenaza-Corona Antonino , Morales-Morales David , Hernández-Ahuactzi Iran F. , Barba Victor
Published: September 2018

The appropriate selection of a given solvent/solvent system influences directly the molecular conformational structures of MLX2 complexes.
New Talent 2018
Authors: Islamoglu Timur , Naumov Panče , Lu Tong-Bu , Farha Omar K.
Published: September 2018

Welcome to this themed issue of CrystEngComm entitled New Talent 2018.
Synthesis of corrugated C-based nanostructures by Br-corannulene oligomerization
Authors: Smerieri Marco , Píš Igor , Ferrighi Lara , Nappini Silvia , Lusuan Angelique , Vattuone Luca , Vaghi Luca , Papagni Antonio , Magnano Elena , Di Valentin Cristiana , Bondino Federica , Savio Letizia
Published: September 2018

The structure and electronic properties of carbon-based nanostructures obtained by metal surface assisted synthesis is highly dependent on the nature of the precursor molecule.
Photogalvanic effect induced fully spin polarized current and pure spin current in zigzag SiC nanoribbons
Authors: Chen Jun , Zhang Liwen , Zhang Lei , Zheng Xiaohong , Xiao Liantuan , Jia Suotang , Wang Jian
Published: September 2018

Using nonequilibrium Green's function combined with density functional theory, we investigate the spin-related current generated by the photogalvanic effect (PGE) in monolayer zigzag SiC nanoribbons (ZSiCNRs) by first-principles calculations.
Surface organometallic chemistry in heterogeneous catalysis
Authors: Samantaray Manoja K. , Pump Eva , Bendjeriou-Sedjerari Anissa , D’Elia Valerio , Pelletier Jérémie D. A. , Guidotti Matteo , Psaro Rinaldo , Basset Jean-Marie
Published: September 2018

Surface organometallic chemistry has been reviewed with a special focus on environmentally relevant transformations (C–H activation, CO2conversion, oxidation).
Synthesis of heterobimetallic gold(i) ferrocenyl-substituted 1,2,3-triazol-5-ylidene complexes as potential anticancer agents
Authors: Aucamp Danielle , Kumar Sreedhar V. , Liles David C. , Fernandes Manuel A. , Harmse Leonie , Bezuidenhout Daniela I.
Published: September 2018

Apoptotic cancer cell death mediated by a cationic gold(i) phosphine complex bearing a ferrocenyl-functionalised mesoionic carbene.
Future potential of osmium complexes as anticancer drug candidates, photosensitizers and organelle-targeted probes
Authors: Zhang Pingyu , Huang Huaiyi
Published: September 2018

Here we summarize recent progress in the design and application of innovative osmium compounds as anticancer agents with diverse modes of action, as organelle-targeted imaging probes and photosensitizers for photodynamic therapy.
Correction: Review of electrical energy storage technologies, materials and systems: challenges and prospects for large-scale grid storage
Authors: M. Gür Turgut
Published: September 2018

Correction for ‘Review of electrical energy storage technologies, materials and systems: challenges and prospects for large-scale grid storage’ by Turgut M. Gür, Energy Environ. Sci., 2018, DOI: 10.1039/c8ee01419a.
A comprehensive investigation of the condensation of furanic platform molecules to C14–C15 fuel precursors over sulfonic acid functionalized silica supports
Authors: Gebresillase Mahlet N. , Shavi Raghavendra , Seo Jeong Gil
Published: September 2018

An approach for the utilization of furfural and its hydrogenation products in the synthesis of high carbon fuel precursors over silica supported sulfonic acid catalysts is reported.
Biocatalytic and solvent-free synthesis of a bio-based biscyclocarbonate
Authors: Wunschik D. S. , Ingenbosch K. N. , Zähres M. , Horst J. , Mayer C. , Jäger M. , Strehmel V. , Dornbusch M. , Hoffmann-Jacobsen K.
Published: September 2018

An enzymatically controlled one-step synthesis of a non-isocyanate polyurethane monomer from sustainable resources is feasible under mild reaction conditions.
Polarization-controlled dynamically switchable plasmon-induced transparency in plasmonic metamaterial
Authors: Ling Yonghong , Huang Lirong , Hong Wei , Liu Tongjun , Luan Jing , Liu Wenbing , Lai Jianjun , Li Hanping
Published: September 2018

We propose a metamaterial to realize dynamically controllable PIT effect. Simply by changing the polarization direction of incident light, the number of PIT transparency windows can be increased from 1 to 2, accompanied with tunable amplitude and switchable resonance-wavelength.
Graphene oxide–silver nanocomposites modulate biofilm formation and extracellular polymeric substance (EPS) production
Authors: Liu Shima , Cao Shuting , Guo Jingyang , Luo Liqiang , Zhou Yi , Lin Chenglie , Shi Jiye , Fan Chunhai , Lv Min , Wang Lihua
Published: September 2018

GO-AgNPs composites can effectively modulate biofilm development and extracellular polymeric substance (EPS) production at an appropriate concentration.
Multiplexed detection of cancer biomarkers using a microfluidic platform integrating single bead trapping and acoustic mixing techniques
Authors: Chen Huaying , Chen Chang , Bai Siwei , Gao Yuan , Metcalfe Guy , Cheng Wenlong , Zhu Yonggang
Published: September 2018

The integration of acoustic micromixing and single bead trapping enables the identification of fluorescent signals from multiple biomarkers within minutes.
EurOgels: A ferromagnetic semiconductor with a porous structure prepared via the assembly of hybrid nanorods
Authors: Trepka Bastian , Stiegeler Julian , Wimmer Ilona , Fonin Mikhail , Polarz Sebastian
Published: September 2018

Synthesis of EuO with a porous structure from the assembly of hybrid nanorods is reported.
Largely enhanced photocatalytic hydrogen production rate of CdS/(Au–ReS2) nanospheres by the dielectric–plasmon hybrid antenna effect
Authors: Liu Jia , Chen Kai , Pan Gui-Ming , Luo Zhi-Jun , Xie Ying , Li Ying-Ying , Lin Yong-Jie , Hao Zhong-Hua , Zhou Li , Ding Si-Jing , Wang Qu-Quan
Published: September 2018

CdS/(Au–ReS2) nanospheres that have highly efficient photocatalytic hydrogen production activity induced by dielectric–plasmon hybrid antenna resonance are synthesized.
Palladium-catalyzed heck-type cascade cyclization of (Z)-1-iodo-1,6-dienes with N-tosyl hydrazones
Authors: Li Jun , Chi Xiaochen , Meng Long , Jiao Luyang , Shang Wenhui , Wang Ping , Zhang Daopeng , Dong Yunhui , Liu Qing , Liu Hui
Published: September 2018

A new way to synthesize tetrahydropyridine derivatives bearing a terminal alkene due to highly regioselective β-H elimination of alkylpalladium species.
Base-mediated [2 + 4] cycloadditions of in situ formed azaoxyallyl cations with N-(2-chloromethyl)aryl amides
Authors: Jin Qiaomei , Gao Meng , Zhang Dongjian , Jiang Cuihua , Yao Nan , Zhang Jian
Published: September 2018

A base-mediated [2 + 4] annulation of in situ formed azaoxyallyl cations with in situ generated aza-oQMs has been realized.
Molecular characteristics of the refractory organic matter in the anaerobic and aerobic digestates of sewage sludge
Authors: Li Xiaowei , Mei Qingqing , Yan Xiaofang , Dong Bin , Dai Xiaohu , Yu Liangliang , Wang Yibo , Ding Guoji , Yu Fang , Zhou John
Published: September 2018

The chemical characteristics of the refractory organic matter in anaerobic and aerobic digestates are hardly known although they are significant for further improving the degradation of organic matter during sludge digestion.
Numerical simulations of wall contact angle effects on droplet size during step emulsification
Authors: Wang Meng , Kong Chuang , Liang Qisen , Zhao Jianxiang , Wen Maolin , Xu Zhongbin , Ruan Xiaodong
Published: September 2018

A study on the effects of wall contact angle makes it more flexible to predict and control the size of droplets generated in step emulsification.
Flexible and enhanced multicolor-emitting films co-assembled by lanthanide complexes and a polymerizable surfactant in aqueous solution
Authors: Lei Nana , Shen Dazhong , Wang Jiao , Chen Xiao
Published: September 2018

Flexible, self-supporting, and organized multicolor-emitting films were fabricated by co-assembling Eu–DPA complexes into a polymerizable LLC and in situ photopolymerization.
Mechanistic insight into dendrite–SEI interactions for lithium metal electrodes
Authors: Hao Feng , Verma Ankit , Mukherjee Partha P.
Published: September 2018

The coupled mechanism of nonuniform Li plating and interfacial stress induced SEI instability is elucidated.
Redox regulation of pyruvate kinase M2 by cysteine oxidation and S-nitrosation
Authors: Mitchell Alice Rose , Yuan Meng , Morgan Hugh P. , McNae Iain W. , Blackburn Elizabeth A. , Le Bihan Thierry , Homem Rafael A. , Yu Manda , Loake Gary J. , Michels Paul A. , Wear Martin A. , Walkinshaw Malcolm D.
Published: September 2018

We show here that the M2 isoform of human pyruvate kinase (M2PYK) is susceptible to nitrosation and oxidation, and that these modifications regulate enzyme activity by preventing the formation of the active tetrameric form. The biotin-switch assay carried out on M1 and M2 isoforms showed that M2PYK is sensitive to nitrosation and that Cys326 is highly susceptible to redox modification. Structural and enzymatic studies have been carried out on point mutants for three cysteine residues (Cys424, Cys358, and Cys326) to characterise their potential roles in redox regulation. Nine cysteines are conserved between M2PYK and M1PYK. Cys424 is the only cysteine unique to M2PYK. C424S, C424A, and C424L showed a moderate effect on enzyme activity with 80, 100, and 140% activity, respectively, compared with M2PYK. C358 had been previously identified from in vivo studies to be the favoured target for oxidation. Our characterised mutant showed that this mutation stabilises tetrameric M2PYK, suggesting that the in vivo resistance to oxidation for the Cys358Ser mutation is due to stabilisation of the tetrameric form of the enzyme. In contrast, the Cys326Ser mutant exists predominantly in monomeric form. A biotin-switch assay using this mutant also showed a significant reduction in biotinylation of M2PYK, confirming that this is a major target for nitrosation and probably oxidation. Our results show that the sensitivity of M2PYK to oxidation and nitrosation is regulated by its monomer–tetramer equilibrium. In the monomer state, residues (in particular C326) are exposed to oxidative modifications that prevent reformation of the active tetrameric form.
Nomograms based on inflammatory biomarkers for predicting tumor grade and micro-vascular invasion in stage I/II hepatocellular carcinoma
Authors: Li Peng , Huang Wei , Wang Feng , Ke Ye-Fang , Gao Lin , Shi Ke-Qing , Zhou Meng-Tao , Chen Bi-Cheng
Published: September 2018

Background: Increasing evidences reveal that inflammation plays a critical role in tumorigenesis and progression. We aimed to develop the nomograms based on inflammatory biomarkers to predict micro-vascular invasion (MVI) and tumor grade in stage I/II hepatocellular carcinoma (HCC).

Methods: A retrospective cohort of 627 patients with stage I/II HCC between January 2007 and December 2014 was included in the study. Logistic regression was performed to identify the independent risk factors of tumor grade and MVI. The significant predictors including neutrophil-to-lymphocyte ratio (NLR), derived neutrophil-to-lymphocyte ratio (dNLR), lymphocyte-to-monocyte ratio (LMR), tumor volume age, and tumor size were subsequently incorporated to build the nomograms. The prediction accuracies of the nomograms were evaluated using the area under the receiver operating characteristic (ROC) curve.

Results: The independent risk factors for tumor grade were NLR, dNLR, and tumor volume (P<0.001, P=0.001, and P<0.001, respectively), which were assembled into tumor grade nomogram. MVI nomogram was developed by dNLR, LMR, age, and tumor size (P<0.001, P<0.001, P<0.001, and P=0.001, respectively) which were the independent predictors for MVI. The area under the ROC curve of nomograms for predicting tumor grade and MVI were 0.727 (95% confidence intervals [CI]: 0.690–0.761) and 0.839 (95% CI: 0.808–0.867), respectively. Patients who had a nomogram score of less than 100 and 79 were considered to have high possibility of moderate grade and have low risks of MVI presence, respectively.

Conclusion: We successfully developed nomograms predicting tumor grade and MVI based on inflammatory biomarkers with high accuracy, leading to a rational therapeutic choice for stage I/II HCC.
Cosmic ray sputtering yield of interstellar H2O ice mantles
Authors: Dartois E. , Chabot M. , Id Barkach T. , Rothard H. , Augé B. , Agnihotri A. N. , Domaracka A. , Boduch P.
Published: September 2018

Aims. Interstellar grain mantles present in dense interstellar clouds are in constant exchange with the gas phase via accretion and desorption mechanisms such as UV, X-ray photodesorption, cosmic ray induced sputtering, grain thermal fluctuations, and chemical reaction energy release. The relative importance of the various desorption mechanisms is of uttermost importance for astrophysical models to constrain the chemical evolution in such high density dense cloud regions.

Methods. The sputtering yields for swift ions simulating the effects of cosmic rays are most often measured in the semi-infinite limit using thick ice targets with the determination of the effective yield per incident ion. In this experimental work we investigated the sputtering yield as a function of ice mantle thickness, exposed to Xe ions at 95 MeV. The ion induced ice phase transformation and the sputtering yield were simultaneously monitored by infrared spectroscopy and mass spectrometry.

Results. The sputtering yield is constant above a characteristic ice layer thickness and then starts to decrease below this thickness. An estimate of the typical sputtering depth corresponding to this length can be evaluated by comparing the infinite thickness yield to the column density where the onset of the sputtering yield decrease occurs. In these experiments the measured characteristic desorption depth corresponds to ≈30 ice layers. Assuming an effective cylindrical shape for the volume of sputtered molecules, the aspect ratio is close to unity; in the semi-infinite ice film case this ratio is the diameter to height of the cylinder. This result shows that most ejected molecules arise from a rather compact volume. The measured infinite thickness sputtering yield for water ice mantles scales as the square of the ion electronic stopping power (Se, deposited energy per unit path length). Considering the experiments on insulators, we expect that the desorption depth dependence varies with Seα, where α ~ 1. Astrophysical models should take into account the thickness dependence constraints of these ice mantles in the interface regions when ices are close to their extinction threshold. In the very dense cloud regions, most of the water ice mantles are above this limit for the bulk of the cosmic rays.
Fast and slow winds from supergiants and luminous blue variables
Authors: Vink Jorick S.
Published: September 2018

We predict quantitative mass-loss rates and terminal wind velocities for early-type supergiants and luminous blue variables (LBVs) using a dynamical version of the Monte Carlo radiative transfer method. First, the observed drop in terminal wind velocity around spectral type B1 is confirmed by the Monte Carlo method at the correct effective temperature of about 21 000 K. This drop in wind velocity is much steeper than would be expected from the drop in escape speed for cooler stars. The results may be particularly relevant for slow winds inferred for some high-mass X-ray binaries. Second, the strength of the mass-loss bi-stability jump is found to be significantly greater than previously assumed. This could this make bi-stability braking more efficient in massive star evolution; in addition, a rotationally induced version of the bi-stability mechanism may now be capable of producing the correct density of outflowing disks around B[e] supergiants, although multi-dimensional modelling including the disk velocity structure is still needed. For LBVs we find that the bi-stability jump becomes larger at higher metallicities, but perhaps surprisingly also larger at lower Eddington parameters. This may have consequences for the role of LBVs in the evolution of massive stars at different metallicities and cosmic epochs. Finally, our predicted low wind velocities may be important for explaining the slow outflow speeds of supernova type IIb/IIn progenitors, for which the direct LBV-SN link was first introduced.
Toward a new paradigm for Type II migration
Authors: Robert C. M. T. , Crida A. , Lega E. , Méheut H. , Morbidelli A.
Published: September 2018

Context. Giant planets open gaps in their protoplanetary and subsequently suffer so-called type II migration. Schematically, planets are thought to be tightly locked within their surrounding disks, and forced to follow the viscous advection of gas onto the central star. This fundamental principle, however, has recently been questioned as migrating planets were shown to decouple from the gas’ radial drift.

Aims. In this framework, we question whether the traditionally used linear scaling of migration rate of a giant planet with the disk’s viscosity still holds. Additionally, we assess the role of orbit-crossing material as part of the decoupling mechanism.

Methods. We have performed 2D (r, θ) numerical simulations of point-mass planets embedded in locally isothermal α-disks in steady-state accretion, with various values of α. Arbitrary planetary accretion rates were used as a means to diminish or nullify orbit-crossing flows.

Results. We confirm that the migration rate of a gap-opening planet is indeed proportional to the disk’s viscosity, but is not equal to the gas drift speed in the unperturbed disk. We show that the role of gap-crossing flows is in fact negligible.

Conclusions. From these observations, we propose a new paradigm for type II migration: a giant planet feels a torque from the disk that promotes its migration, while the gap profile relative to the planet is restored on a viscous timescale, thus limiting the planet migration rate to be proportional to the disk’s viscosity. Hence, in disks with low viscosity in the planet region, type II migration should still be very slow.
Protostellar Outflows at the EarliesT Stages (POETS)
Authors: Sanna A. , Moscadelli L. , Goddi C. , Krishnan V. , Massi F.
Published: September 2018

Context.Weak and compact radio continuum and H2O masers are preferred tracers of the outflow activity nearby very young stars.

Aims.We want to image the centimeter free–free continuum emission in the range 1–7 cm (26–4 GHz), which arises in the inner few 1000 au from those young stars also associated with bright H2O masers. We seek to study the radio continuum properties in combination with the H2O maser kinematics to quantify the outflow energetics powered by single young stars.

Methods.We made use of theKarl G. JanskyVery Large Array (VLA) in the B configuration atKband and the A configuration at bothKuandCbands in order to image the radio continuum emission toward 25 H2O maser sites with an angular resolution and thermal rms on the order of 0.′′1 and 10μJy beam−1, respectively. These targets add to our pilot study of 11 maser sites previously presented. The sample of H2O maser sites was selected among those regions that have accurate distance measurements, obtained through maser trigonometric parallaxes, and H2O maser luminosities in excess of 10−6L⊙.

Results.We present high-resolution radio continuum images of 33 sources belonging to 25 star-forming regions. In each region, we detect radio continuum emission within a few 1000 au of the H2O masers’ position; 50% of the radio continuum sources are associated with bolometric luminosities exceeding 5 × 103L⊙, including W33A and G240.32 + 0.07. We provide a detailed spectral index analysis for each radio continuum source, based on the integrated fluxes at each frequency, and produce spectral index maps with the multifrequency synthesis deconvolution algorithm of CASA. The radio continuum emission traces thermal bremsstrahlung in (proto)stellar winds and jets that have flux densities at 22 GHz below 3 mJy and spectral index values between − 0.1 and 1.3. We prove a strong correlation (r> 0.8) between the radio continuum luminosity (Lrad) and the H2O maser luminosity (LH2O) of (L8 GHz∕mJy kpc2) = 103.8× (LH2OL⊙)0.74. This power-law relation is similar to that between the radio continuum and bolometric luminosities, which confirms earlier studies. Since H2O masers are excited through shocks driven by (proto)stellar winds and jets, these results provide support to the idea that the radio continuum emission around young stars is dominated by shock ionization, and this holds over several orders of magnitude of stellar luminosites (1–105L⊙).
Probing the protoplanetary disk gas surface density distribution with 13CO emission
Authors: Miotello A. , Facchini S. , van Dishoeck E. F. , Bruderer S.
Published: September 2018

Context. How protoplanetary disks evolve is still an unsolved problem where different processes may be involved. Depending on the process, the disk gas surface density distribution Σgas may be very different and this could have diverse implications for planet formation. Together with the total disk mass, it is key to constrain Σgas as function of disk radius R from observational measurements.

Aims. In this work we investigate whether spatially resolved observations of rarer CO isotopologues, such as 13CO, may be good tracers of the gas surface density distribution in disks.

Methods. Physical-chemical disk models with different input Σgas(R) were run, taking into account CO freeze-out and isotope-selective photodissociation. The input disk surface density profiles were compared with the simulated 13CO intensity radial profiles to check whether and where the two follow each other.

Results. For each combination of disk parameters, there is always an intermediate region in the disk where the slope of the 13CO radial emission profile and Σgas(R) coincide. In the inner part of the disk, the line radial profile underestimates Σgas, as 13CO emission becomes optically thick. The same happens at large radii where the column densities become too low and 13CO is not able to efficiently self-shield. Moreover, the disk becomes too cold and a considerable fraction of 13CO is frozen out, thus it does not contribute to the line emission. If the gas surface density profile is a simple power-law of the radius, the input power-law index can be retrieved within a ~20% uncertainty if one choses the proper radial range. If instead Σgas(R) follows the self-similar solution for a viscously evolving disk, retrieving the input power-law index becomes challenging, in particular for small disks. Nevertheless, we find that the power-law index γ can be in any case reliably fitted at a given line intensity contour around 6 K km s−1, and this produces a practical method to constrain the slope of Σgas(R). Application of such a method is shown in the case study of the TW Hya disk.

Conclusions. Spatially resolved 13CO line radial profiles are promising to probe the disk surface density distribution, as they directly trace Σgas(R) profile at radii well resolvable by ALMA. There, chemical processes like freeze-out and isotope-selective photodissociation do not affect the emission, and, assuming that the volatile carbon does not change with radius, no chemical model is needed when interpreting the observations.
Influence of metallicity on the near-surface effect on oscillation frequencies
Authors: Manchon L. , Belkacem K. , Samadi R. , Sonoi T. , Marques J. P. C. , Ludwig H.-G. , Caffau E.
Published: September 2018

Context. The CoRoT and Kepler missions have provided high-quality measurements of the frequency spectra of solar-like pulsators, enabling us to probe stellar interiors with a very high degree of accuracy by comparing the observed and modelled frequencies. However, the frequencies computed with 1D models suffer from systematic errors related to the poor modelling of the uppermost layers of stars. These biases are what is commonly named the near-surface effect. The dominant effect is thought to be related to the turbulent pressure that modifies the hydrostatic equilibrium and thus the frequencies. This has already been investigated using grids of 3D hydrodynamical simulations, which also were used to constrain the parameters of the empirical correction models. However, the effect of metallicity has not been considered so far.

Aims. We aim to study the impact of metallicity on the surface effect, investigating its influence across the Hertzsprung-Russell diagram, and providing a method for accounting for it when using the empirical correction models.

Methods. We computed a grid of patched 1D stellar models with the stellar evolution code CESTAM in which poorly modelled surface layers have been replaced by averaged stratification computed with the 3D hydrodynamical code CO5BOLD. It allowed us to investigate the dependence of both the surface effect and the empirical correction functions on the metallicity.

Results. We found that metallicity has a strong impact on the surface effect: keeping Teff and log g constant, the frequency residuals can vary by up to a factor of two (for instance from [Fe/H] = + 0.0 to [Fe/H] = + 0.5). Therefore, the influence of metallicity cannot be neglected. We found that the correct way of accounting for it is to consider the surface Rosseland mean opacity. It allowed us to give a physically grounded justification as well as a scaling relation for the frequency differences at νmax as a function of Teff, log g and κ. Finally, we provide prescriptions for the fitting parameters of the most commonly used correction functions.

Conclusions. We show that the impact of metallicity through the Rosseland mean opacity must be taken into account when studying and correcting the surface effect.
Oxygen and silicon abundances in Cygnus OB2
Authors: Berlanas S. R. , Herrero A. , Comerón F. , Simón-Díaz S. , Cerviño M. , Pasquali A.
Published: September 2018

Context. Cygnus OB2 is a rich OB association in the Galaxy located at only ∼1.4 kpc from us which has experienced intense star formation in the last 20–25 Myr. Its stellar population shows a correlation between age and Galactic longitude. Exploring the chemical composition of its stellar content we will be able to check the degree of homogeneity of the natal molecular cloud and possible effects of self-enrichment processes.

Aims. Our aim is to determine silicon and oxygen abundances for a sample of eight early-type slow rotators (with rotational velocities below 80 km s−1) in Cygnus OB2 in order to check possible inhomogeneities across the whole association and whether there exists a correlation of chemical composition with Galactic longitude.

Methods. We have performed a spectroscopic analysis of a sample of late O and early B stars with low rotational velocity in Cygnus OB2, which have been chosen so as to cover the whole association area. We have carried out an analysis based on equivalent widths of metal lines, the wings of the H Balmer lines and FASTWIND stellar atmosphere models to determine their stellar fundamental parameters (effective temperature and surface gravity) as well as the silicon and oxygen surface abundances.

Results. We derive a rather homogeneous distribution of silicon and oxygen abundances across the region, with average values of 12 + log(Si/H) = 7.53 ± 0.08 dex and 12 + log(O/H) = 8.65 ± 0.12 dex.

Conclusions. We find a homogeneous chemical composition in Cygnus OB2 with no clear evidence for significant chemical self-enrichment, despite indications of strong stellar winds and possible supernovae during the history of the region. Comparison with different scenarios of chemical enrichment by stellar winds and supernovae point to star forming efficiencies not significantly above 10%. The degree of homogeneity that we find is consistent with the observed Milky Way oxygen gradient based on H II regions. We also find that the oxygen scatter within Cygnus OB2 is at least of the same order than among H II regions at similar Galactocentric distance.
Recreational angling as a vector of freshwater invasions in Central Italy: perceptions and prevalence of illegal fish restocking
Authors: Cerri Jacopo , Ciappelli Alessandro , Lenuzza Andrea , Zaccaroni Marco , Nocita Annamaria
Published: September 2018

Italian freshwater ecosystems were strongly affected by biological invasions during the last few decades. Recreational angling contributed to this, through the widespread use of invasive alien species for fish restocking. To date, no research is available about the psychological and structural determinants of deliberate fish restocking in Italy. This work aims to fill this research gap, through structured questionnaires administered to a sample of recreational anglers (n = 276) in the Arno river basin (Central Italy). A predictive model for fish restocking, based on a quasi-binomial logistic regression, was fit and multi-model inference was drawn, to highlight the most significant predictors. Respondents, who expected that most anglers practiced restocking and who believed restocking could create closer fishing spots, were more prone to illegally restock fish. Our findings indicate that expectations about illegal fish restocking might exist among specialized segments of anglers. Targeted communication campaigns must be enforced as soon as possible to change them. Furthermore, fish restocking is supposed to reduce the travel costs for angling: future research about this is needed to model invasion hotspots.
Standards of hygiene for ultrasound-guided core cut biopsies of the breast
Authors: Heil Jörg , Hug Sarah , Martiny Heike , Golatta Michael , Feisst Manuel , Madjar Helmut , Bader Werner , Hahn Markus
Published: September 2018

Purpose The aim was to obtain an overview of the hygiene measures undertaken during ultrasound guided core cut biopsies of the breast by experts certified by the German Society for Ultrasound in Medicine in order to derive recommendations for clinical routine, taking into account the available literature and the lack of evidence based guidelines.

Materials and Methods A survey was conducted with all members of the levels I to III of the breast ultrasound working group of the German Society for Ultrasound in Medicine. The estimation of the risk of infection after a core cut biopsy of the breast was asked for as well as the hygiene measures undertaken in practice to avoid infection.

Results The risk of infection after a core cut biopsy of the breast was estimated to be one per thousand (median value). The most commonly performed hygiene measures were a spray, wipe, spray desinfection (98.1 %) and the use of sterile gloves (54.7 %).

Conclusion Due to the very low risk of infection we recommend the routine use of gloves and an adequate skin disinfection. Contact of the transducer or of an unsterile contact medium with the biopsy needle is considered highly unlikely und should be avoided.
Evaluation des Gesundheitsverhaltens und der Lebensqualität dermatoonkologischer Patienten nach operativer Therapie eines Hauttumors
Authors: Hoernecke D. , Pföhler C. , Wagenpfeil S. , Vogt T. , Müller C.
Published: September 2018

Hintergrund In der Onkologie existieren unterschiedliche Erkenntnisse bzgl. einer Änderung im Gesundheitsverhalten der betroffenen Patienten nach Diagnosestellung eines malignen Tumors (z. B. beim kolorektalen Karzinom oder bei gynäkologischen Karzinomen). Derlei Daten existieren bislang nicht in größerem Umfang für dermatoonkologische Patienten.

Fragestellung Ziel dieser Querschnittstudie mittels Fragebogen und Korrelation mit retrospektiven Daten war es, herauszufinden, ob Hauttumorpatienten ihr Gesundheitsverhalten (Sonnenexposition, Freizeitverhalten, Raucherentwöhnung etc.) nach dermatochirurgischer Therapie/Behandlung ändern und damit den ärztlichen Empfehlungen folgen. Zudem wurde die Lebensqualität der Patienten nach operativer Therapie von Hauttumoren erfasst.

Material und Methoden In die Studie wurden 653 Patienten eingeschlossen, welche im Jahre 2013 unter stationären Bedingungen aufgrund eines oder mehrerer maligner Hauttumore operativ behandelt wurden. Mittels Fragebögen wurden die postoperative Lebensqualität sowie das Freizeit- und Gesundheitsverhalten erfasst und analysiert. Ergebnisse: 263/653 Patienten nahmen an der Befragung teil (Rücklaufquote 40,3 %). 62,0 % der Patienten waren männlich, 38,0 % weiblich. Der Altersdurchschnitt lag bei 69,8 Jahren. Überraschenderweise konnten wir eine Umstellung der Lebensweise hin zu gesünderen Eigenschaften (Reduktion des Alkoholkonsums, gesündere Ernährung) und Reduktion der Risikofaktoren (Reduktion der Sonnenexposition und Schutz vor UV-Strahlung) feststellen. Eine Abhängigkeit der Verhaltensänderungen vom Bildungsstand, Geschlecht oder dem Familienstand ergab sich hingegen nicht. Die Nutzung textilen Sonnenschutzes sowie der Umgang mit sportlicher Betätigung änderte sich nicht. Hinsichtlich der Lebensqualität zeigten sich unsere Patienten generell zufriedener als die deutsche Allgemeinbevölkerung. Weibliches Geschlecht, das Leben mit einem Partner, ein hohes Bildungsniveau sowie höheres Lebensalter wirkten sich bei unseren Patienten positiv auf die Lebensqualität aus.

Diskussion Vor dem Hintergrund einer weiter notwendigen Verbesserung der primären und auch sekundären Präventionsmaßnahmen erscheint auch eine Optimierung spezifischer Aufklärungsinhalte in der Dermatoonkologie notwendig. Insbesondere der Einfluss einer gesunden Lebensweise spielt hier eine Rolle. Die Auswirkungen der Hautkrebserkrankung auf die Lebensqualität waren geringer als von uns erwartet. Dies kann als Ursprung für den verminderten Antrieb zur Lebensstilveränderung gesehen werden.

Limitationen Der Homburger Gesundheitsbogen wurde eigens entwickelt und nicht in Testverfahren validiert. Die Patienten wurden nur einmalig angeschrieben. Erinnerungsmaßnahmen oder Incentives wurden nicht genutzt.
Endoscopic Assisted Retrosigmoid Approach for Cerebellopontine Angle Epidermoid Tumor
Authors: Kunigelis Katherine , Yang Alexander , Youssef A.
Published: September 2018

This case is a 20-year-old male, who presented with 1 month of right facial weakness (HB4) and complaints of ipsilateral eye dryness. He was initially treated for Bell's palsy with steroids and antiviral agents, but subsequently developed diplopia with right lateral gaze and underwent an MRI (magnetic resonance imaging). MRI demonstrated a 4.5 cm irregular lesion in the right cerebellopontine angle consistent with an epidermoid cyst. Because the tumor had grown with the development of the central nervous system, it has extended into different compartments, including the tentorial incisura and pineal region. A predefined surgical corridor created by the tumor facilitated access to the majority of the tumor through a retrosigmoid approach. Angled endoscopes (30-degree up and down) provided further visualization of tumor away from the line of sight of the microscope, thus allowing for gross total resection of the lesion. This video also demonstrates a sharp dissection technique necessary for safe removal of adherent tumor from critical neurovascular structures, including the basilar artery and several cranial nerves. The ipsilateral auditory evoked responses (ABRs) showed slight improvement from baseline toward the end of the case. A gross total resection was achieved, as shown by the MRI. The patient remained at his baseline cranial nerve (CN) V, VII, and VIII deficits during the immediate postoperative period.

The link to the video can be found at: https://youtu.be/vCq5juJh8hk.
Retrosigmoid Craniotomy for Resection of an Epidermoid Cyst of the Posterior Fossa
Authors: Kalani M. , Couldwell William
Published: September 2018

This video illustrates the case of a 51-year-old woman who presented with sudden-onset headache, vertigo, and nausea. Imaging revealed an epidermoid cyst of the posterior fossa with mass effect upon the brainstem and displacement of the basilar artery. This lesion was approached using a left-sided keyhole retrosigmoid craniotomy with monitoring of the cranial nerves. This video illustrates the technique of internal debulking of the cyst contents with minimal manipulation of the cyst capsule, which is often densely adherent to the brainstem, cranial nerves, and vessels in the posterior fossa. Resection of the capsule is often associated with a higher rate of cranial nerve deficits. The tumor was removed completely, but the cyst capsule was left in place. The patient had House–Brackmann grade II facial paralysis postoperatively and complained of some diminished hearing in the left ear. Epidermoid cysts are benign tumors, but the patient may experience much morbidity from their overly aggressive resection, especially when the capsule is densely adhering to critical structures. An alternate strategy is to decompress the contents of the epidermoid cyst, thereby decompressing the brainstem and converting this disease process into a chronic disease that may require reoperation in the long term. Given the tight confines of the posterior fossa, aggressive internal decompression of tumors and mobilization from the brainstem and adjacent nerves are key to avoiding injury to the brainstem and cranial neuropathies. In patients with benign tumors, the goal of the operation should be decompression of the brainstem and preservation of cranial nerve function.

The link to the video can be found at: https://youtu.be/nk8-VztB0OI.
The Use of Fetal Bronchoscopy in the Diagnosis and Management of a Suspected Obstructive Lung Mass
Authors: Chon Andrew , Stein James , Gerstenfeld Tammy , Wang Larry , Vazquez Walter , Chmait Ramen
Published: September 2018

Etiologies of fetal lung anomalies include congenital pulmonary airway malformation (CPAM), intra- or extralobar pulmonary sequestration, congenital high airway obstruction syndrome (CHAOS), bronchogenic cyst, and bronchial atresia. Fetal tracheobronchoscopy has been reported both as a diagnostic and therapeutic procedure in the setting of severe congenital lung lesions. In this case report, prenatal imaging of a fetus with a large chest mass was suspicious for an obstructive bronchial lesion. The absence of visible normal lung tissue on the right side and mass effect on the left side raised the concern for pulmonary hypoplasia. After antenatal betamethasone and a period observation, hydropic changes developed. Fetal tracheobronchoscopy was then performed in an effort to identify and decompress the suspected obstructive bronchial lesion. Other than release of bronchial debris, no anatomical abnormalities were visualized. However, the right lung lesion and mediastinal shift both decreased after the fetal bronchoscopy. The newborn underwent postnatal resection of a CPAM Type II and is doing well. We hypothesize that fetal tracheobronchoscopy provided the following potential diagnostic and therapeutic benefits: (1) exclusion of an obstructive bronchial lesion; (2) disimpaction of bronchial debris from the saline lavage that we posit may have contributed to the rapid reduction in CPAM size.
Vaporization energy and expansion velocity of electrically exploding aluminum and copper fine wires in vacuum
Authors: Hamilton A. , Sotnikov V. I. , Sarkisov G. S.
Published: September 2018

It has been experimentally shown that the complete vaporization of Al and Cu fine wires due to a fast electrical explosion in vacuum requires 2-3 times the standard atomization enthalpy of ∼4 eV/atom. The expansion speed of a fully evaporated Al wire in vacuum is ∼10 km/s and ∼8 km/s for Cu wire. This excess of evaporation energy over tabulated enthalpy of atomization is related to the “pressure cooker effect,” when a fine metal wire is heated by a fast-rising current with high magnetic and hydrodynamic pressures. In our paper, we demonstrate self-consistent relationships between the deposited energy, expansion rate, and state of the wire core for Al and Cu fine wires.
Memory effects in the ion conductor Rb2Ti2O5
Authors: Federicci Rémi , Holé Stéphane , Démery Vincent , Leridon Brigitte
Published: September 2018

Recent studies on Rb2Ti2O5 crystals have demonstrated remarkable electrical properties. This material exhibits colossal electrical polarization between 200 K and 330 K. In the present work, we report on the observation of memory effects in Rb2Ti2O5 due to charge accumulation and discuss the genuine memristive character of this material. An analytical model is proposed for the system, which takes into account the ionic diffusion and ionic migration and is in good agreement with the observed volatile memristive properties of the material.
Tutorial: Fabrication and three-dimensional integration of nanoscale memristive devices and arrays
Authors: Lin Peng , Xia Qiangfei
Published: September 2018

To catch up with growing complexity of artificial neural networks, hybrid integrated systems with high-density nanoscale memristive devices have been proposed as building blocks for the next generation computing hardware. In this Tutorial, we first introduce the methodologies in fabrication of memristor crossbars with a sub-10 nm feature size, including nanoimprint lithography that provides excellent resolution at low cost. Technical issues such as critical dimension control, overlay alignment accuracy, and reliable mold cleaning are discussed in detail. In the meantime, as lateral scaling becomes more challenging, three-dimensional (3D) integration presents an alternative solution to further increase the packing density and to provide new functionalities. Some early demonstrations of 3D hybrid memristor/complementary metal oxide semiconductor circuits are reviewed here, and their design and fabrication related issues are discussed. Successful implementation of large-scale 3D memristive systems with nanometer scale devices may provide ultimate solution to the hardware bottleneck for future computing applications.