bluuebunny/crossref_metadata_2025 huggingface dataset:
Milieu Intérieur
Authors: Hasan Milena
Published: May 2019

Le projet Milieu Intérieur vise à élucider les facteurs environnementaux et héréditaires qui façonnent un système immunitaire sain, et à définir ses frontières lors de l’homéostasie et à la suite d’une stimulation immunitaire. Le projet repose sur un phénotypage immunitaire de 1 000 donneurs sains. En corrélant les mesures obtenues par analyse en cytométrie en flux de la composition des cellules immunitaires du sang périphérique en homéostasie avec les métadonnées associées, nous avons défini des valeurs de référence de phénotypes en fonction du sexe et de l’âge et constaté un impact significatif du tabagisme et de l’infection latente par le cytomégalovirus sur les phénotypes mesurés. Nous avons également identifié onze nouveaux polymorphismes (SNP, single-nucleotide polymorphism), associés à des phénotypes spécifiques de certaines cellules immunitaires. Des conduites expérimentales robustes et standardisées ont été établies pour quantifier les signatures protéiques et transcriptionnelles de la réponse immunitaire résultant de la stimulation des cellules du sang périphérique et pour explorer les déterminants génétiques et non-génétiques de la variabilité de cette réponse. Les approches analytiques établies par Milieu Intérieur et l’ensemble des données recueillies pourront ainsi servir de référence pour des études comparatives avec différentes maladies.
L’interleukine 33
Authors: Schmitt Pauline , Girard Jean-Philippe , Cayrol Corinne
Published: May 2019

L’interleukine-33 est une cytokine nucléaire de la famille de l’IL-1, exprimée par les cellules endothéliales et épithéliales des tissus en contact avec l’environnement. Elle est libérée lors de dommages tissulaires et joue le rôle d’alarmine en prévenant le système immunitaire d’un danger. Elle est impliquée dans l’immunité innée de type-2 et l’inflammation allergique, mais des études récentes suggèrent qu’elle peut, selon le contexte environnemental, jouer d’autres rôles dans l’homéostasie ou l’immunité antivirale, par exemple. Elle est associée à de nombreuses pathologies, notamment allergiques, inflammatoires ou infectieuses, et pourrait être une cible thérapeutique de choix pour le traitement de l’asthme sévère.
Crassostrea gigas, une huître au service de la recherche sur le cancer
Authors: Corporeau Charlotte , Huvet Arnaud , Pichereau Vianney , Delisle Lizenn , Quéré Claudie , Dubreuil Christine , Artigaud Sébastien , Brenner Catherine , Meyenberg Cunha-De Padua Monique , Mazure Nathalie
Published: May 2019

L’effet Warburg est l’une des caractéristiques des cellules cancéreuses chez l’homme. C’est une véritable reprogrammation métabolique vers la glycolyse aérobie, permettant aux cellules cancéreuses de satisfaire leurs besoins énergétiques en fonction du microenvironnement qu’elles rencontrent au sein de la tumeur. De par son mode de vie, l’huître Crassostrea gigas possède des capacités particulières afin d’adapter son métabolisme aux changements extrêmes du milieu dans lequel elle se trouve. Elle est naturellement capable de reprogrammer son métabolisme vers l’effet Warburg. C. gigas représente ainsi un modèle d’intérêt pour étudier comment l’environnement peut contrôler l’effet Warburg dans des conditions qui ne pourraient être explorées chez des espèces modèles vertébrés.
Des souris, des rats et des hommes
Authors: Hardin-Pouzet Hélène , Morosan Serban
Published: May 2019

La recherche biomédicale est considérée par nos sociétés comme une nécessité et les réflexions sur les moyens à mettre en œuvre pour la développer s’accordent sur le constat que : « à défaut de pouvoir expérimenter sur l’homme, l’expérimentation animale est indispensable » [1]. Celle-ci, pour être légitime, doit respecter la fameuse règle des 3R (Raffiner, Remplacer, Réduire) énoncée dès 1959 par Russell et Burch [2]. En effet, bien que permettant certaines approches moléculaires, expérimentales ou modélisées, les méthodes alternatives conservent un caractère réducteur et ne permettent pas d’appréhender l’ensemble d’un organisme au sein de son environnement. À ce jour, il reste donc encore indispensable d’utiliser des modèles animaux pour générer des connaissances valides en recherche fondamentale et appliquée. La recherche fait ainsi appel à une grande variété d’organismes-modèles, parmi lesquels les rongeurs (rats et souris) sont les plus utilisés : en France, en 2016, 59,6 % des animaux utilisés pour la recherche étaient des souris et 8,9 % étaient des rats [3]. Le propos de cet article est de montrer en quoi les rongeurs sont des modèles expérimentaux importants et de donner quelques exemples des connaissances nouvelles qu’ils ont apportés.
Die praktische Ausbildung des medizinischen Nachwuchses –
Identifizierung von Lehrpraxen-Charakteristika in der
Allgemeinmedizin
Authors: Grunewald Dorit , Pilic Larisa , Bödecker August-Wilhelm , Robertz Jörg , Althaus Astrid
Published: May 2019

Hintergrund Eine flächendeckende hausärztliche Versorgung
wird durch die soziodemografische Entwicklung der Bevölkerung sowie
durch Nachwuchsprobleme in der Allgemeinmedizin gefährdet. Positive
Erfahrungen Medizinstudierender während absolvierter Praktika in den
akademischen Lehrpraxen wecken das Interesse am Beruf des allgemeinmedizinischen
Hausarztes. Bislang gab es jedoch keine hinlänglichen Untersuchungen,
welche Lehrpraxen-Charakteristika von Bedeutung sein können, um
Medizinstudierende für den Beruf als Hausarzt zu begeistern.

Methoden Es wurden vier Fokusgruppen mit insgesamt 22 Studierenden
durchgeführt. Die Gruppendiskussionen wurden aufgezeichnet,
anschließend transkribiert und danach mittels qualitativer
Inhaltsanalyse softwareunterstützt ausgewertet.

Ergebnisse Variablen, die die wahrgenommene Attraktivität des
Berufs des Hausarztes steigerten waren Anleitung und Betreuung durch den
Lehrpraxen-Inhaber sowie dessen Feedback-Verhalten, eine offene und respektvolle
Haltung des Lehrarztes gegenüber den Studierenden, die
Möglichkeit zum selbstständigen Arbeiten, das breite
Krankheitsspektrum und der abwechslungsreiche Arbeitsalltag, langjährige
Arzt-Patienten-Beziehungen sowie eine ausgewogene Work-Life Balance. Variablen,
die die wahrgenommene Attraktivität des Berufs Hausarztes reduzierten
waren das wirtschaftliche Risiko der Praxisgründung und
Selbstständigkeit, das Überweisen von Patienten zu Spezialisten
bei „interessanten Befunden“ sowie eine nicht ausgewogene
Work-Life Balance.

Schlussfolgerung Die praktische Ausbildung Medizinstudierender in
Lehrpraxen hat das Potenzial, die Attraktivität des Berufes Hausarzt zu
steigern und damit die Wahrscheinlichkeit, dass Studierende sich später
für den Tätigkeitsbereich „Hausarzt“
entscheiden. Dazu bedarf es motivierter Lehrpraxen-Inhaber, die Studierenden
einen positiven Einblick in den Praxisalltag vermitteln.
Septic Shock and Death after Microwave Ablation of Hepatocellular Carcinoma in a Liver Transplant Patient with a Bilioenteric Anastomosis
Authors: Melikian Raymond , Minocha Jeet
Published: May 2019

Percutaneous thermal ablation of hepatic tumors continues to play an integral role in the treatment of early-stage primary or secondary hepatic malignancies. Interventional radiologists must be familiar with potential complications of this procedure, associated risk factors, and methods for prevention. The authors report a devastating case of septic shock and death following percutaneous microwave ablation of a solitary hepatocellular carcinoma in a liver transplant patient with a bilioenteric anastomosis (BEA). We review the literature regarding prophylactic antibiotic regimens and bowel preparation prior to performing thermal ablation in patients with BEAs.
Nanometer scale structural and compositional inhomogeneities of half-Heusler CoTi1-xFexSb thin films
Authors: Bonef Bastien , Harrington Sean D. , Pennachio Daniel J. , Speck James. S. , Palmstrøm Chris J.
Published: May 2019

The correlative use of X-ray diffraction (XRD), scanning transmission electron microscopy (STEM), and atom probe tomography (APT) allows the structure of substitutionally alloyed half-Heusler compound CoTi1-xFexSb to be characterized at the nanometer scale. For x = 0.2, 0.3, and 0.5, XRD patterns indicate an epitaxial cube-on-cube growth with no detectable secondary phases and are suggestive of high crystalline quality for all three of the films. This is supported using atomic resolution STEM images, which revealed the absence of secondary phases or polycrystalline regions, thus confirming the half-Heusler structure of the CoTi1-xFexSb films. For all three samples, the APT reconstructions were optimized to resolve the atomic planes in the [001] growth direction allowing the exploitation of reliable datasets. The presence of Fe-rich phases in the samples with Fe atoms sitting on Ti crystallographic sites is revealed. A strong phase separation is observed for x = 0.2 and x = 0.3 and is almost no longer observed for x = 0.5 in good agreement with the magnetic properties of the films.
Thermal stability of NDR-assisted anomalous Hall effect based magnetic device
Authors: Singh Rajan , Luo Zhaochu , Lu Ziyao , Saleemi Awais Siddique , Xiong Chengyue , Zhang Xiaozhong
Published: May 2019

Both semiconductor and magnetic material properties are highly dependent on the environment temperature, and this is one of the critical obstacles limiting the application of these materials at high temperatures. In this work, a negative differential resistance-assisted anomalous Hall effect-based magnetic device has been fabricated and its thermal stability has been studied. The magnetic device was found quite stable and gave a reliable output current ratio of >104% in the temperature range of 0 °C–100 °C. The load-line analysis was performed to study the mechanism of thermal stability of this device in 0 °C–100 °C. It was found that the magnetic device exhibits improved thermal stability, with resistance variation in the range of 0 °C–100 °C being reduced by ∼40% compared to semiconductor-only devices. This study suggests that integrating magnetic and semiconductor properties together not only offer flexibility to integrate a number of applications in one simple device but also possible to provide thermal stability.
Effect of non-thermal plasma on AHL-dependent QS systems and biofilm
formation in Pseudomonas aeruginosa: Difference between
non-hospital and clinical isolates
Authors: Paldrychová Martina , Vaňková Eva , Scholtz Vladimír , Julák Jaroslav , Sembolová Eliška , Mat’átková Olga , Masák Jan
Published: May 2019

Non-thermal plasma (NTP), generated by DC cometary discharge with a metallic grid at atmospheric pressure, was used to eradicate biofilm of Pseudomonas aeruginosa from titanium alloy Ti-6Al-4V carriers. The NTP exposure may reduce the ability of signal molecules to cause quorum sensing (QS) response in P. aeruginosa and as a result, affect the production of virulence factors including biofilm formation. Two groups of P. aeruginosa were compared, namely strains isolated from the environment (non-hospital) and clinical isolates from hospital environment. For the non-hospital strains, the inhibition of QS systems, mediated mainly by N-acyl-homoserine lactone (AHL) signals, and decrease of total biofilm biomass were observed after the NTP treatment. After 60 minutes of exposure, almost complete eradication of biofilm (54 - 98%) was achieved. Compared to that, the NTP effect on the AHL levels was more pronounced in clinical isolates of P. aeruginosa, but eradication of the biofilm was not achieved. We conclude that NTP affected the AHL-dependent QS systems (las and rhl), which does not necessarily have to result in the regulation of virulence in clinical isolates.
Exploring the impact of proteins on the line tension of a phase-separating ternary lipid mixture
Authors: Bandara Asanga , Panahi Afra , Pantelopulos George A. , Nagai Tetsuro , Straub John E.
Published: May 2019

The separation of lipid mixtures into thermodynamically stable phase-separated domains is dependent on lipid composition, temperature, and system size. Using molecular dynamics simulations, the line tension between thermodynamically stable lipid domains formed from ternary mixtures of di-C16:0 PC:di-C18:2 PC:cholesterol at 40:40:20 mol. % ratio was investigated via two theoretical approaches. The line tension was found to be 3.1 ± 0.2 pN by capillary wave theory and 4.7 ± 3.7 pN by pressure tensor anisotropy approaches for coarse-grained models based on the Martini force field. Using an all-atom model of the lipid membrane based on the CHARMM36 force field, the line tension was found to be 3.6 ± 0.9 pN using capillary wave theory and 1.8 ± 2.2 pN using pressure anisotropy approaches. The discrepancy between estimates of the line tension based on capillary wave theory and pressure tensor anisotropy methods is discussed. Inclusion of protein in Martini membrane lipid mixtures was found to reduce the line tension by 25%–35% as calculated by the capillary wave theory approach. To further understand and predict the behavior of proteins in phase-separated membranes, we have formulated an analytical Flory-Huggins model and parameterized it against the simulation results. Taken together these results suggest a general role for proteins in reducing the thermodynamic cost associated with domain formation in lipid mixtures and quantifies the thermodynamic driving force promoting the association of proteins to domain interfaces.
Enhanced thermal conductivity of multilayered sheets of polyethylene and boron nitride via promoting molecular diffusion between layers
Authors: Shi Ai , Li Yue , Liu Wei , Lei Jun , Xu Ling , Li Zhong-Ming
Published: May 2019

In this work, we alternatively compressed a high density polyethylene/low molecular weight polyethylene (LMWPE)/hexagonal boron nitride (h-BN) composite layer and a low density polyethylene layer together to fabricate thermally conductive bulk products. Compared to our previous work (without the LMWPE component), introducing the short chain component, i.e., LMWPE, into the composite layers further enhanced the h-BN content to 18.3 vol. %, and, thus, more thermally conductive paths could be formed after annealing, resulting in higher thermal conduction performance. Also, the annealed multilayered cuboid in this work exhibited a high thermal conductivity of 1.96 (W/m K), 43% higher than that of our previous study (1.37 W/m K). In contrast with that of the samples with randomly distributed h-BN at the same loading, an approximately 145% enhancement was achieved. The results demonstrate that our method to fabricate the multilayered cuboids has a great opportunity for application in the thermal management field of electric devices.
Oxygen vacancy mediated conductivity and charge transport properties of epitaxial Ba0.6La0.4TiO3−
δ
thin films
Authors: Li Qiang , Zhang Aihua , Gao Dong , Guo Min , Feng Jiajun , Zeng Min , Fan Zhen , Chen Deyang , Gao Xingsen , Zhou Guofu , Lu Xubing , Liu J.-M.
Published: May 2019

We report on the effects of the oxygen vacancy (VO) regarding the microstructure, conductivity, and charge transport mechanisms of epitaxial Ba0.6La0.4TiO3−δ (BLTO) films. The VO concentration can be largely regulated from 21.5% to 37.8% by varying the oxygen pressure (PO2) during film deposition. Resistivity-temperature and Hall effect measurements demonstrate that the BLTO films can be tuned remarkably from an insulator to a semiconductor, and even to a metallic conductor by regulating the VO concentration. The role of VO concentration in the charge transport mechanism is clarified. For films with low VO concentration, the charge transport is dominated by variable range hopping (VRH) at low temperatures, and it shows small polaron (SP) hopping at high temperatures. For films with high VO concentration, the carrier transport remains VRH at low temperatures, while it changes to SP hopping at moderate temperatures, and is dominated by thermal phonon scattering at high temperatures. Furthermore, the lower starting temperature of SP hopping for films with higher VO concentrations indicates that VO favors electron-phonon coupling. Different charge transport mechanisms are assumed to be due to different VO-induced defect energy levels in the BLTO films, which has been verified by their soft x-ray absorption spectroscopy results.
Reproducing global potential energy surfaces with continuous-filter convolutional neural networks
Authors: Brorsen Kurt R.
Published: May 2019

Neural networks fit to reproduce the potential energy surfaces of quantum chemistry methods offer a realization of analytic potential energy surfaces with the accuracy of ab initio methods at a computational cost similar to classical force field methods. One promising class of neural networks for this task is the SchNet architecture, which is based on the use of continuous-filter convolutional neural networks. Previous work has shown the ability of the SchNet architecture to reproduce density functional theory energies and forces for molecular configurations sampled during equilibrated molecular dynamics simulations. Due to the large change in energy when bonds are broken and formed, the fitting of global potential energy surfaces is normally a more difficult task than fitting the potential energy surface in the region of configurational space sampled during equilibrated molecular dynamics simulations. Herein, we demonstrate the ability of the SchNet architecture to reproduce the energies and forces of the potential energy surfaces of the H + H2 and Cl + H2 reactions and the OCHCO+ and H2CO/cis-HCOH/trans-HCOH systems. The SchNet models reproduce the potential energy surface of the reactions well with the best performing SchNet model having a test set root-mean-squared error of 0.52 meV and 2.01 meV for the energies of the H + H2 and Cl + H2 reactions, respectively, and a test set mean absolute error for the force of 0.44 meV/bohr for the H + H2 reaction. For the OCHCO+ and H2CO/cis-HCOH/trans-HCOH systems, the best performing SchNet model has a test set root-mean-squared error of 2.92 meV and 13.55 meV, respectively.
Analysis of transient-absorption pump-probe signals of nonadiabatic dissipative systems: “Ideal” and “real” spectra
Authors: Palacino-González Elisa , Gelin Maxim F. , Domcke Wolfgang
Published: May 2019

We introduce and analyze the concept of the “ideal” time and frequency resolved transient-absorption pump-probe (PP) signal. The ideal signal provides the most direct link between the “real” (measurable) PP signal and the material system dynamics. The simulation of PP signals involves two steps. (i) The ideal signal, which exhibits perfect time and frequency resolution, is calculated. For this purpose, the probe pulse is replaced by an auxiliary continuous-wave pulse. (ii) The real signal is obtained by the convolution of the ideal signal with the appropriate time- and frequency-gate function, which depends on the envelope of the actual probe pulse. This concept has been used to simulate integral and dispersed PP signals for a model system exhibiting nonadiabatic and dissipative dynamics. The ideal signal is computed with the two-pulse equation-of-motion phase-matching approach which has been extended to take excited-state absorption into account. We demonstrate how the ideal signal, an object exhibiting the features of moving wave packets as well as stationary spectra, is related to real signals detected with short (good temporal resolution) or long (good frequency resolution) probe pulses.
930 kA/cm2 peak tunneling current density in GaN/AlN resonant tunneling diodes grown on MOCVD GaN-on-sapphire template
Authors: Growden Tyler A. , Cornuelle Evan M. , Storm David F. , Zhang Weidong , Brown Elliott R. , Whitaker Logan M. , Daulton Jeffrey W. , Molnar Richard , Meyer David J. , Berger Paul R.
Published: May 2019

We report on the design and fabrication of ultrahigh current density GaN/AlN double barrier resonant tunneling diodes grown via rf-plasma assisted molecular-beam epitaxy. The device structure was grown on a metal-organic chemical vapor deposition GaN-on-sapphire template. The devices displayed repeatable room temperature negative differential resistance with peak tunneling current densities (Jp) between 637 and 930 kA/cm2. Analysis of temperature dependent measurements revealed the presence of severe self-heating effects, which allow strong phonon scattering that deteriorates the electron quantum transport. Finally, a qualitative comparison to the same structure grown on a low dislocation density freestanding GaN substrate has shown that sapphire-based templates are a feasible alternative.
Methane dissociation on stepped Ni surfaces resolved by impact site, collision energy, vibrational state, and lattice distortion
Authors: Guo Han , Jackson Bret
Published: May 2019

We explore the dynamics and kinetics of methane dissociation on the steps of Ni(211) and the terraces of Ni(111), as models for step and terrace sites, respectively, on a real Ni catalyst. A quantum approach is used to compute state resolved sticking probabilities, S0, and the thermally averaged sticking is computed from both S0 and more standard transition state methods. While the barriers can be much lower on the step edges, the terrace atoms can make important contributions to the overall reactivity if the step density is not too high and/or at higher temperatures. At 500 K, we find that for reaction on the step edge, sticking is dominated by molecules with either one or two quanta of bending vibration excited, with translational energies of about 0.10–0.35 eV or 0–0.2 eV, respectively. These energies are well below the rigid lattice activation energies, and reaction requires both a significant conversion of vibrational energy into motion along the reaction path and puckering of the lattice atom over which the molecule dissociates. We show that the average amount of puckering, which lowers the barrier to reaction, is about 0.28 Å at 500 K. Reactions are dominated by collisions at impact sites within a few tenths of an Å of the minimum barrier pathway at the step edge. Our computed sticking probabilities for reaction on the step at 500 K are in good agreement with available experimental data.
Effect of Structure Change on Luminescent Properties of CsPbBr2I Perovskite Nanocrystals after Heat Treatment
Authors: Li Ji , Wang Li , Gao Xin
Published: May 2019

Lead halide perovskite nanocrystals (NCs) are still a popular subject in the field of luminescence because of their high photoluminescence quantum yield (PLQY) and colour tenability through anion exchange reactions or quantum confinement. We investigated the structure and luminescence properties of the mixed halide perovskites CsPbBr2I NCs with annealing temperatures. The results showed that the average grain size of CsPbBr2I increased with increasing the temperature from 300 to 440K, and the morphology changed above 380K. The normalised PL spectra of CsPbBr2I NCs had an obvious blue-shift, and then displayed a slight red-shift with increasing annealing temperature. In addition, the PL intensities, peak energies, and bandwidths of the NC films as a function of temperature were discussed in detail.
Critical Assessment 33: Dislocation density-based constitutive modelling for steels with austenite
Authors: Kang Jee-Hyun , Kim Sung-Joon
Published: May 2019

To understand the high strain hardening capability of austenitic steels, dislocation density-based constitutive modelling has been actively employed. Despite the variation in their formulation, all models explain flow stress in terms of the density of dislocations, which are generated and annihilated simultaneously throughout the deformation. Taylor coefficient, shear modulus, twin fraction, and annihilation coefficients, which are key model parameters, are discussed in detail. The model is expected to be applied not only to austenite containing multiphase steels but also to design face-centred cubic-based alloys.
Effect of ultrasonic treatment on the mechanical behaviour of Al–Ni alloys
Authors: Srivastava Neeraj , Chaudhari G. P.
Published: May 2019

Applications of Al–Ni alloys are limited because their matrix is weaker than other binary aluminium alloys. Ultrasonic treatment (UST) is an effective tool for grain refinement that can strengthen the matrix phase. It not only reduces the grain size and porosity but also refines and uniformly distributes the secondary phase, which can influence the mechanical properties of Al–Ni alloys. Varying the amount of nickel (1, 2, 3, and 5 wt-%) in molten aluminium along with ultrasonication of the melt is investigated through grain-structure, mechanical properties, and fractography. Mechanical properties of the alloys subjected to UST are superior to respective as-cast alloys. UST also altered the fracture behaviour from dominant ductile fracture in as-cast alloys to dominant mixed mode fracture.
Supporting mathematics vocabulary instruction through mathematics curricula
Authors: Barnes Erica M. , Stephens S. Joy
Published: May 2019

This study examines four of the most commonly‐used core mathematics curricula in the USA for evidence of support for research‐based instructional strategies for mathematics vocabulary in first and second grade. Content analyses of the teachers’ editions of two units for each grade level were analyzed per curriculum (n = 16). Statistically significant differences among curricula were found for number of target words (range 6–51 per unit), level of difficulty of terms (basic to technical), and number of support strategies per word. Multiple means of representation varied in terms of verbal and non‐verbal strategies for target terms. These differences indicate children are experiencing substantially different mathematics vocabulary learning opportunities, which may impact later mathematics achievement. Implications for practice, curriculum development, and future research are addressed.
PTEN reduces endosomal PtdIns(4,5)P2 in a phosphatase-independent manner via a PLC pathway
Authors: Mondin Virginie E. , Ben El Kadhi Khaled , Cauvin Clothilde , Jackson-Crawford Anthony , Bélanger Emilie , Decelle Barbara , Salomon Rémi , Lowe Martin , Echard Arnaud , Carréno Sébastien
Published: May 2019

The tumor suppressor PTEN dephosphorylates PtdIns(3,4,5)P3 into PtdIns(4,5)P2. Here, we make the unexpected discovery that in Drosophila melanogaster PTEN reduces PtdIns(4,5)P2 levels on endosomes, independently of its phosphatase activity. This new PTEN function requires the enzymatic action of dPLCXD, an atypical phospholipase C. Importantly, we discovered that this novel PTEN/dPLCXD pathway can compensate for depletion of dOCRL, a PtdIns(4,5)P2 phosphatase. Mutation of OCRL1, the human orthologue of dOCRL, causes oculocerebrorenal Lowe syndrome, a rare multisystemic genetic disease. Both OCRL1 and dOCRL loss have been shown to promote accumulation of PtdIns(4,5)P2 on endosomes and cytokinesis defects. Here, we show that PTEN or dPLCXD overexpression prevents these defects. In addition, we found that chemical activation of this pathway restores normal cytokinesis in human Lowe syndrome cells and rescues OCRL phenotypes in a zebrafish Lowe syndrome model. Our findings identify a novel PTEN/dPLCXD pathway that controls PtdIns(4,5)P2 levels on endosomes. They also point to a potential new strategy for the treatment of Lowe syndrome.
HDAC6 and Miro1: Another interaction causing trouble in neurons
Authors: Van Den Bosch Ludo
Published: May 2019

Myelin-associated glycoprotein and chondroitin sulfate proteoglycans in the extracellular matrix can prevent regeneration of injured axons. In this issue, Kalinski et al. (2019. J. Cell Biol. https://doi.org/10.1083/jcb.201702187) report that inhibition of HDAC6 prevents the deacetylation of Miro1, increases mitochondrial axonal transport, and restores the size of axonal growth cones.
Topology Optimization Design of Compliant Mechanism of Composite Wing Leading Edge
Authors: Zhao Lijie , Li Kai , Chang Yingying , Li Jingkui
Published: May 2019

This paper introduces a topology optimization design method for flexible mechanism of composite wing leading edge based on discrete material optimization (DMO) with composite material. The DMO method is combined with the topology optimization to select the deviation of the actual displacement and the target displacement of the 10 coordinate points on the initial curve of the leading edge as the objective function, and the volume fraction of each phase material is used as the constraint to establish the composite material optimization model, which is solved by the OC optimization criterion method. The MATLAB codes are compiled to calculate the optimization problem and a distinct result image is obtained. The CATIA software is used to model the topology image in three dimensions, and the model is imported into Hyperworks software for simulation analysis. The results show that this complaint mechanism can achieve a maximum deflection of 9.1 degrees, which verifies the feasibility of the method.
Aircraft Surface Trajectory Prediction Method Based on LSTM with Attenuated Memory Window
Authors: Ma Zhiming , Yao Mengfei , Hong Tao , Li Bo
Published: May 2019

With the rapid development of the global air transport industry, airport surface traffic is increasingly busy. The safety hazards of taxiing conflict still exist during the airport operation for the initially planned taxiing path about aircraft, which directly affects the operational safety and efficiency of the airport surface. Using the correlation and dependence between the position sequences of aircraft glide motion, a method based on Long Short Term Memory networks (LSTM) is used. Combining the change of the motion state of the surface aircraft, the attenuation memory window is introduced to improve the hidden layer structure to further enhance the prediction accuracy in the LSTM model, and it is compared and verified under different parameters. The method realizes the target of surface position prediction for the aircraft in future period, lays the foundation for aircraft surface taxiing conflict detecting, and avoids taxiing conflict.
Analysis on the Aerodynamic Characteristics of a Continuous Whole Variable Camber Airfoil
Authors: Zhao Anmin , Hui Zou , Jin Haichuan , Wen Dongsheng
Published: May 2019

In this paper, based on the genetic algorithm, a 4-section optimization airfoil structure is designed, which can change entire camber of the airfoil. For this new type of integral changeable camber airfoil, its first structure cam be deflected downward by 30 degrees, the second section is fixed, the third stage be capable of deflect downward by 30 degrees, and the fourth section be able to bend up and down by 30 degrees. In addition, the computational fluid dynamics method is adopted to numerically simulate the aerodynamic performance of variable camber airfoils. The numerical results observe that the used of varying camber airfoil has better been stalling characteristics and larger lift coefficient comparison with the Clark Y airfoil and NACA114 airfoil.
Numerical Experiment of Flow Around a Compound Airfoil
Authors: Yokoi Yoshifumi
Published: May 2019

A numerical simulation around a compound airfoil was performed using the vortex method. The compound airfoil consists of a front airfoil, a fixed wing, and a rear airfoil, and it assumes the rudder of a submarine. As for the shape of the front airfoil and the rear airfoil, NACA0012 was used. Reynolds number was Re = 3.8×105. In the numerical simulation, the angle of attack of a front airfoil and a rear airfoil was changed, and the magnitude of the gap between these movable airfoils and the fixed wing was changed. The time history of the fluid force of acting on an airfoil, and the flow pattern were investigated. The total lift was greatly produced, when the front airfoil and rear airfoil attached the same attack angle as the same direction. It was found that the total lift with the large one where the gap between these movable airfoils and the fixed wing is larger can be obtained. It was found that the rear airfoil governs the flow of the compound airfoil.
Nonlinear Aeroelastic Modeling of a Folding Wing Structure
Authors: Li Peicheng , Ni Yingge , Hou Chi , Wan Xiaopeng , Zhao Meiying
Published: May 2019

The nonlinear aeroelastic response of a folding wing with the hinge free-play nonlinearity is investigated. A nonlinear structural dynamic model is established based on the modal synthesis of free-substructures by modification of the connected relationships, and is unnecessary to re-establish it if the stiffness changes. The nonlinear aeroelastic equation is obtained by rational function approximation of the unsteady aerodynamic force, and solved by Runge-Kutta method to predict the aeroelastic response of the folding wing. The results show that the free-play at hinges changes the aeroelastic characteristic of the folding wing, leading to the occurrence of the limit cycle oscillation within a certain velocity range. Moreover, the sensitivity to the free-play is different for the inboard and outboard hinges. If the free-play is controlled within a certain value, the motion of nonlinear aeroelastic system of the folding wing can be considered linear approximately.
Design and Analysis of Rotor/Wing Flap for Canard Rotor/Wing Aircraft
Authors: Deng Yangping , Mi Baigang
Published: May 2019

In the present study, a kind of blunt trailing edge airfoil with its flap is designed for the purpose of reducing drags of blunt leading and trailing edge airfoils which are used for rotor/wing of CRW. The aerodynamic characteristics of designed flaps and elliptic airfoil which has the same thickness are numerically investigated based on the Reynolds-averaged Navier–Stokes equations and the SST k-ω two-equation turbulence model. The comparisons of aerodynamic force and moment coefficients show that, the lift characteristic is improved for designed flaps, but the drag will not be reduced if the flap has great bending trailing edge, and small bending trailing edge design is suitable for this kind of flap, and it will reduce the drag and improve the longitudinal stability characteristics.
Observer-Based Backstepping Fault-tolerant Control for Spacecraft with Reaction-wheel Failures
Authors: Zhang Z Z , Ye D , Sun Z W
Published: May 2019

In this paper, nonlinear satellite system with actuator faults is considered. To solve the problem of attitude stabilization of satellite under external disturbances and actuator faults, an observer is designed firstly. And the output of the observer is proved to be uniformly ultimately bounded. By using the estimated information of the observer, a backstepping fault-tolerant controller is derived. The proposed controller could achieve attitude stabilization in the presence of actuator faults. Finally, a simulation of attitude stabilization is carried out to illustrate effective of the fault-tolerant controller
Modeling and Simulation of Satellite Attitude Dynamics and Control System using Modelica
Authors: Liu Y H , Shangguan D S , Yao J , Chen L P , Ding J W
Published: May 2019

The control of attitude of a satellite is difficult to verify since several subsystems of different disciplines, e.g., flexible multibody dynamics, machines, electronics and control, are involved and strongly coupled. A traditional method is to model each single discipline subsystem with a domain specific software, and combine them through interfaces. However, the problems are that lots of interfaces between software have to be developed, and manual decoupling of systems should be considered during modelling process. In this Paper, models of the dynamics and the control system are established in a unified modelling software, MWorks, which is an Integrated Development Environment of Modelica. The model can be used to verify the satellite control strategy, and also provide an effective means for satellite attitude control system design. Moreover, on this basis, the whole satellite was modelled to access state parameters changes under the coupling of the dynamic subsystem, the attitude control subsystem, the power supply subsystem, the propulsion subsystem and the integrated electronic subsystem can be synthetically considered.
Optimal Formation Control for Quadrotors with Collision Avoidance Based on Dynamic Constraints
Authors: Jin P F , Yu J Q , Jia Z Y , Yang D
Published: May 2019

This paper studied the optimal formation control of quadrotor UAV based on the dynamic model, and the collision avoidance between quadrotors is considered. By constructing the problem into a standard convex quadratic programming problem, we hope to improve the solving efficiency of the formation control problem. Firstly, the nonlinear dynamic model of quadrotor is linearized and the prediction model is established. Then, the safety zone constraints are transformed from a circular zone to a half-plane zone, making the optimization problem be a standard convex quadratic programming problem. Finally, the quadratic programming problem is solved using distributed receding horizon optimization. Numerical simulations in three-dimensional space show that this method can obtain the optimal formation trajectory with collision avoidance, and can improve the solving efficiency.
Image Processing Techniques for Shock Wave Detection and Tracking in High Speed Schlieren and Shadowgraph Systems
Authors: Li Guoshuai , Burak Agir Muhammed , Kontis Konstantinos , Ukai Takahiro , Rengarajan Sriram
Published: May 2019

Schlieren and shadowgraph photography has been widely used to offer insight into the flow field in aerospace engineering due to their ease of application. The high-speed schlieren and shadowgraph techniques are typically applied to investigation of unsteady shock wave structure including shock reflection patterns and shock wave/boundary layer interactions, etc. Generally, qualitative analysis is performed based on the schlieren and shadowgraph image sequences. To process and analyze the large data set of the high-speed schlieren and shadowgraph images quantitatively, especially for the shock wave detection and tracking, a software was developed based on MATLAB GUI and its image processing toolbox. In this study, the image processing techniques exploited in the software, such as background subtraction, filter, threshold, edge detection, and shock tracking are presented. A case study on the phenomena of shock wave reflection from a solid surface was conducted. The results show that the proper filter method and the background image subtraction can effectively eliminate the image noises in frequency domain, which makes it easier to analyze the flow structure. Moreover, the instantaneous locations of shock waves are detected accurately, and the shock wave propagation speed calculated using the developed software are consistent with those of previous studies.
Neural Partial Differentiation Based Nonlinear Parameter Estimation from Noisy Flight Data
Authors: Mohamed Majeed , Madhavan G , Manikantan R , Priya PS Lal
Published: May 2019

This paper focuses on the application of neural partial differentiation (NPD) approach to estimate the longitudinal parameters of an aircraft HFB 320 from noisy flight data. By exciting both short period and phugoid modes of an aircraft with thrust variation, the aircraft system dynamics becomes highly nonlinear and aerodynamic parameters appears nonlinear to the state trajectories of velocity, AOA, pitch rate and pitch angle. This paper highlights the application of NPD for such a class of nonlinear dynamics; previously it was used only for the estimation of parameter appearing linear to the states. The extracted the nonlinear longitudinal parameters of HFB 320 aircraft are compared with the parameters estimated by using adaptive Unscented Kalman Filter (UKF) approach. Finally, the estimation results are validated by comparing with flight data and the responses obtained from the estimates by adaptive UKF.
Research on Binding Memory of Icon Features Based on Event-related Potential
Authors: Niu Y F , Shi B Z , Qiu L C , Li B , Shen Q Y , Xue C Q
Published: May 2019

The visual characteristics are important factors influencing the cognition and memory of the icon. In order to study the process of memory coding of feature binding in working memory of icon, the experiment requires 20 subjects to remember whether the icon features or feature binding are consistent and response quickly by pressing buttons, and the behaviour data and ERP data of the subjects are recorded. The experiment results show that compared with single feature memory of an icon, the accuracy under the icon-color feature binding memory condition is lower and the reaction time is longer while the P300 brain electric component with larger amplitude can be triggered. Studies have shown that the binding of visual features in icon memory requires additional cognitive resources. Compared with the other three memory conditions, the latency of the P300 under icon semantic-color feature binding is more significant, indicating that the task of semantic coding of icon is more difficult to complete and the cognitive load is greater.
Assurance and Evaluation Method for Reliability Requirements Completion of Aviation Product Based on CMM
Authors: Li Yuan , Wang Wei , Feng Weijia , Zhang Qi , Liu Huichao
Published: May 2019

Modern aviation product needs to meet the reliability requirements during the development process. In this paper, a comprehensive assurance system of reliability requirements completion is established and a method to evaluate the assurance system capabilities of reliability requirements completion based on CMM (Capability Maturity Model) is proposed. The evaluate index system in each level is described and AHP method is applied to determine the weight of each index factor in maturity. The evaluation results can comprehensively and effectively direct the aviation product reliability work during the development process and ultimately ensure the reliability of aviation product meets the requirements.
A Cognitive Study of Multicolour Coding for the Head-up Display (HUD) of Fighter Aircraft in Multiple Flight Environments
Authors: Ling Bai , Bo Li , Bingzheng Shi , Lingcun Qiu , Chengqi Xue , Yafeng Niu
Published: May 2019

By analyzing flight environments and HUD key information of fighter combat mission, based on the theory of color psychology and the regulation of the avionics system, this study simplified 10 kinds of typical flight environments and combined with 7 types of key information colors into 70 color schemes. Taking reaction accuracy and reaction time as performance indicators and testing participants’ subjective feelings, to evaluate pilots’ recognition ability of key information and general information with different color schemes in different flight environments, so as to provide the scientific basis for information coding design of flight HUD. The experimental results showed that the cognitive performance of the bicolor coding is significantly better than that of the monochrome coding by comparing the mean reaction time in various environments, and the cognitive performance of color schemes with the hue of 320 or 340 was better than that of other color schemes in most environments.
Two Problems for a Strip with a Transverse Crack: Exact Solutions
Authors: Guangming Yu , Kovalenko M D , Menshova I V , Kerzhaev A P
Published: May 2019

In this paper for the first time we have constructed the exact solutions of two boundary value problems of the theory of elasticity for an infinite strip with a central transverse crack on which a constant normal stress is given (even-symmetric deformation). In the first problem the sides of the strip are free, while in the second they are rigidly clamped. The solution is represented in the form of series in Papkovich–Fadle eigenfunctions. The expansion coefficients (Lagrange coefficients) have the form of simple Fourier integrals. The final formulas are simple and can easily be used in engineering.
Increased probability of compound long-duration dry and hot events in Europe during summer (1950–2013)
Authors: Manning Colin , Widmann Martin , Bevacqua Emanuele , Van Loon Anne F , Maraun Douglas , Vrac Mathieu
Published: May 2019

The propagation of drought from meteorological drought to soil moisture drought can be accelerated by high temperatures during dry periods. The occurrence of extremely long-duration dry periods in combination with extremely high temperatures may drive larger soil moisture deficits than either extreme occurring alone, and lead to severe impacts. In this study, we propose a framework to both characterise long-duration meteorological droughts that co-occur with extremely high temperatures and quantify their probability. We term these events as long-duration, dry and hot (DH) events and characterise them by their duration (D) and magnitude (M). D is defined as the consecutive number of days with precipitation below 1 mm, while M is the maximum daily maximum temperature during an event. A copula-based approach is then employed to estimate the probability of DH events. The framework is applied to Europe during the summer months of June, July and August. We also assess the change in probability that has occurred over the historical period 1950–2013 and find an increased probability of DH events throughout Europe where rising temperatures are found to be the main driver of this change. Dry periods are becoming hotter, leading to an increase in the occurrence of long-duration dry periods with extremely high temperatures. Some parts of Europe also show an increased probability of long-duration events although the relative change is not as strong as that seen with temperature. The results point to a predominant thermodynamic response of DH events to global warming and reaffirm previous research that soil moisture drought events are setting in faster and becoming more severe due to a change in the contributing meteorological hazards. It is hoped that the framework applied here will provide a starting point for further analysis of DH events in other locations and for the assessment of climate models.
Ultrametric properties for valuation spaces of normal surface singularities
Authors: García Barroso Evelia , Pérez Pedro , Popescu-Pampu Patrick , Ruggiero Matteo
Published: May 2019

Let

L
L

be a fixed branch – that is, an irreducible germ of curve – on a normal surface singularity

X
X

. If

A
,
B

A,B

are two other branches, define
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="u Subscript upper L Baseline left-parenthesis upper A comma upper B right-parenthesis colon equals StartFraction left-parenthesis upper L dot upper A right-parenthesis left-parenthesis upper L dot upper B right-parenthesis Over upper A dot upper B EndFraction">

u

L

(
A
,
B
)
:=

(
L
⋅
A
)

(
L
⋅
B
)

A
⋅
B

u_{L}(A,B) := \dfrac {(L \cdot A) \> (L \cdot B)}{A \cdot B}

, where

A
⋅
B

A \cdot B

denotes the intersection number of

A
A

and

B
B

. Call

X
X

arborescent if all the dual graphs of its good resolutions are trees. In a previous paper, the first three authors extended a 1985 theorem of Płoski by proving that whenever

X
X

is arborescent, the function

u

L

u_{L}

is an ultrametric on the set of branches on

X
X

different from

L
L

. In the present paper we prove that, conversely, if

u

L

u_{L}

is an ultrametric, then

X
X

is arborescent. We also show that for any normal surface singularity, one may find arbitrarily large sets of branches on

X
X

, characterized uniquely in terms of the topology of the resolutions of their sum, in restriction to which

u
L

u_L

is still an ultrametric. Moreover, we describe the associated tree in terms of the dual graphs of such resolutions. Then we extend our setting by allowing

L
L

to be an arbitrary semivaluation on

X
X

and by defining

u

L

u_{L}

on a suitable space of semivaluations. We prove that any such function is again an ultrametric if and only if

X
X

is arborescent, and without any restriction on

X
X

we exhibit special subspaces of the space of semivaluations in restriction to which

u

L

u_{L}

is still an ultrametric.