bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamic Load Modelling within Combined Transport Trains during Transportation on a Railway Ferry
Authors: Lovska Alyona , Fomin Oleksij , Píštěk Václav , Kučera Pavel
Published: August 2020

The development of foreign economic activity of the Eurasian states led to the introduction of rail and ferry transportation. It is important to note that the current normative documentation does not fully cover the issues of transporting combined trains by sea. This can lead to a violation of the traffic safety of both the railway ferry and the transport of containers as part of combined trains by sea. In this connection, we investigated the dynamic loading of a container as part of a combined train when transported by a railway ferry. To ensure the stability of the container relative to the frame, we suggested an improvement of the load-bearing structure of a flat wagon. Additionally, we suggested the use of a viscous linkage between containers with the aim of reducing their dynamic load. To justify the suggested solutions, we carried out a mathematical modelling of the container dynamic load. The calculation was performed in MathCad. Due to the fact that the container has its own degree of freedom when transported by sea, the accelerations were separately determined for the supporting structure of the flat wagon and for the container. We found that the total amount of acceleration that acted on the container was 3.57 m/s2 (0.36 g) and on the load-bearing structure of the wagon was 2.47 m/s2 (0.25 g) which were, respectively, 38% and 23% less than the acceleration values in the typical scheme of their interaction. To determine the fields of acceleration distribution relative to the load-bearing structure of a flat wagon with containers, we carried out computer modelling of their dynamic load. The maximum percentage of discrepancy between the accelerations obtained by mathematical and computer modelling was 17.7%. The study will contribute to the creation of recommendations for the safe transport of combined trains by sea, as well as to increasing the efficiency of combined transport through international transport corridors.
Acoustic Improvements of Aircraft Headrests Based on Electrospun Mats Evaluated Through Boundary Element Method
Authors: Giannella Venanzio , Branda Francesco , Passaro Jessica , Petrone Giuseppe , Barbarino Mattia , Citarella Roberto
Published: August 2020

This work illustrates the development of passive noise control (PNC) improvements of aircraft headrests to enhance the acoustic comfort for passengers. Two PNC improvements were studied with the aim of reducing the noise perceived by passengers during flight. Two headrest configurations, with and without the lateral caps, and two different materials, a traditional foam and an innovative Silica/Polyvinylpyrrolidone (PVP) woven non-woven mat, were considered, and compared in terms of sound pressure level (SPL) perceived by passengers. Boundary element method (BEM) models were built up to evaluate the acoustic performances of different headrest configurations, varying in terms of shape and textile. A spherical distribution of monopole sources surrounding the headrests was considered as acoustic load, in such a way as to recreate a diffuse acoustic field simulating the cabin noise perceived by passengers during cruise conditions. The impact of the two PNC improvements was analyzed to envisage some general guidelines useful to design advanced headrests from the acoustic viewpoint.
Theoretical Optimization of Trapped-Bubble-Based Acoustic Metamaterial Performance
Authors: Gritsenko Dmitry , Paoli Roberto
Published: August 2020

Acoustic metamaterials have proven to be a versatile tool for the precise control and manipulation of sound waves. One of the promising designs of acoustic metamaterials employ the arrays of bubbles and find applications for soundproofing, blast mitigation, and many others. An obvious advantage of bubble-based metamaterials is their ability to be relatively thin while absorbing low-frequency sound waves. The vast majority of theories developed to predict resonant behavior of bubble-based metamaterials capitalize on Minnaert frequency. Here, we propose a novel theoretical approach to characterize bubble-based metamaterials that are based on our previous findings for a single bubble trapped in circular cavity modeled as a thin clamped plate. We obtain analytical expressions for resonant frequencies of bubble metascreens using self-consistent approximation. Two geometry factors, distance between bubble centers and distance between bubble center and interface of acoustic impedance change, are taken into account. We demonstrate the existence of multiple bandgaps and possibility of switching between them via adjustment of geometry parameters and reflector properties.
Proximal Policy Optimization Through a Deep Reinforcement Learning Framework for Multiple Autonomous Vehicles at a Non-Signalized Intersection
Authors: Quang Tran Duy , Bae Sang-Hoon
Published: August 2020

Advanced deep reinforcement learning shows promise as an approach to addressing continuous control tasks, especially in mixed-autonomy traffic. In this study, we present a deep reinforcement-learning-based model that considers the effectiveness of leading autonomous vehicles in mixed-autonomy traffic at a non-signalized intersection. This model integrates the Flow framework, the simulation of urban mobility simulator, and a reinforcement learning library. We also propose a set of proximal policy optimization hyperparameters to obtain reliable simulation performance. First, the leading autonomous vehicles at the non-signalized intersection are considered with varying autonomous vehicle penetration rates that range from 10% to 100% in 10% increments. Second, the proximal policy optimization hyperparameters are input into the multiple perceptron algorithm for the leading autonomous vehicle experiment. Finally, the superiority of the proposed model is evaluated using all human-driven vehicle and leading human-driven vehicle experiments. We demonstrate that full-autonomy traffic can improve the average speed and delay time by 1.38 times and 2.55 times, respectively, compared with all human-driven vehicle experiments. Our proposed method generates more positive effects when the autonomous vehicle penetration rate increases. Additionally, the leading autonomous vehicle experiment can be used to dissipate the stop-and-go waves at a non-signalized intersection.
Exposure of Human Skin Organoids to Low Genotoxic Stress Can Promote Epithelial-to-Mesenchymal Transition in Regenerating Keratinocyte Precursor Cells
Authors: Cavallero Sophie , Neves Granito Renata , Stockholm Daniel , Azzolin Peggy , Martin Michèle T. , Fortunel Nicolas O.
Published: August 2020

For the general population, medical diagnosis is a major cause of exposure to low genotoxic stress, as various imaging techniques deliver low doses of ionizing radiation. Our study investigated the consequences of low genotoxic stress on a keratinocyte precursor fraction that includes stem and progenitor cells, which are at risk for carcinoma development. Human skin organoids were bioengineered according to a clinically-relevant model, exposed to a single 50 mGy dose of γ rays, and then xeno-transplanted in nude mice to follow full epidermis generation in an in vivo context. Twenty days post-xenografting, mature skin grafts were sampled and analyzed by semi-quantitative immuno-histochemical methods. Pre-transplantation exposure to 50 mGy of immature human skin organoids did not compromise engraftment, but half of xenografts generated from irradiated precursors exhibited areas displaying focal dysplasia, originating from the basal layer of the epidermis. Characteristics of epithelial-to-mesenchymal transition (EMT) were documented in these dysplastic areas, including loss of basal cell polarity and cohesiveness, epithelial marker decreases, ectopic expression of the mesenchymal marker α-SMA and expression of the EMT promoter ZEB1. Taken together, these data show that a very low level of radiative stress in regenerating keratinocyte stem and precursor cells can induce a micro-environment that may constitute a favorable context for long-term carcinogenesis.
The Intrinsically Disordered W Protein Is Multifunctional during Henipavirus Infection, Disrupting Host Signalling Pathways and Nuclear Import
Authors: Tsimbalyuk Sofiya , Cross Emily , Hoad Mikayla , Donnelly Camilla , Roby Justin , Forwood Jade
Published: August 2020

Nipah and Hendra viruses are highly pathogenic, zoonotic henipaviruses that encode proteins that inhibit the host’s innate immune response. The W protein is one of four products encoded from the P gene and binds a number of host proteins to regulate signalling pathways. The W protein is intrinsically disordered, a structural attribute that contributes to its diverse host protein interactions. Here, we review the role of W in innate immune suppression through inhibition of both pattern recognition receptor (PRR) pathways and interferon (IFN)-responsive signalling. PRR stimulation leading to activation of IRF-3 and IFN release is blocked by henipavirus W, and unphosphorylated STAT proteins are sequestered within the nucleus of host cells by W, thereby inhibiting the induction of IFN stimulated genes. We examine the critical role of nuclear transport in multiple functions of W and how specific binding of importin-alpha (Impα) isoforms, and the 14-3-3 group of regulatory proteins suggests further modulation of these processes. Overall, the disordered nature and multiple functions of W warrant further investigation to understand henipavirus pathogenesis and may reveal insights aiding the development of novel therapeutics.
Thin SiNC/SiOC Coatings with a Gradient of Refractive Index Deposited from Organosilicon Precursor
Authors: Szymanowski Hieronim , Olesko Katarzyna , Kowalski Jacek , Fijalkowski Mateusz , Gazicki-Lipman Maciej , Sobczyk-Guzenda Anna
Published: August 2020

In this work, optical coatings with a gradient of the refractive index are described. Its aim was to deposit, using the RF PECVD method, films of variable composition (ranging from silicon carbon-oxide to silicon carbon-nitride) for a smooth change of their optical properties enabling a production of the filter with a refractive index gradient. For that purpose, two organosilicon compounds, namely tetramethyldisilazane and hexamethyldisilazane, were selected as precursor compounds. The results reveal better optical properties of the materials obtained from the latter source. Depending on whether deposited in pure oxygen atmosphere or under conditions of pure nitrogen, the refractive index of the coatings amounted to 1.65 and to 2.22, respectively. By using a variable composition N2/O2 gas mixture, coatings of intermediate magnitudes of “n” were acquired. The optical properties were investigated using both UV-Vis absorption spectroscopy and variable angle spectroscopic ellipsometry. The chemical structure of the coatings was studied with the help of Fourier transform infrared and X-ray photoelectron spectroscopies. Finally, atomic force microscopy was applied to examine their surface topography. As the last step, a “cold mirror” type interference filter with a gradient of refractive index was designed and manufactured.
Effects of Bias Voltages on the Structural, Mechanical and Oxidation Resistance Properties of Cr–Si–N Nanocomposite Coatings
Authors: Xiang Yanxiong , Huang Lingling , Zou Changwei
Published: August 2020

Cr–Si–N nanocomposite coatings were deposited by multi-arc ion plating under different bias voltages. The influences of bias voltage on composition, microstructure, surface morphology and mechanical properties of Cr–Si–N nanocomposite coatings were investigated in detail. The HR-TEM, XRD, and XPS results confirmed the formation of nanocomposite structure of nanocrystalline of CrN embedded into the amorphous phase of Si3N4. The particle radius of CrN can be calculated from the half-width of the diffraction peak of CrN (200) and the value was about 20–60 nm. In addition, no diffraction peaks of CrSi2, Cr3Si, or Si3N4 were found in all the Cr–Si–N coatings. With the increasing of bias voltages from 0 to −200 V, the number and size of large droplets on the coating surface decreased, and the growth mode of the coatings changed from loose to dense. However, with the increasing of bias voltages from 0 to −200 V, the micro-hardness of the coatings increased and then decreased, reaching its maximum value at negative bias voltages of 100 V. It was found that the friction coefficient of Cr–Si–N coatings is almost the same except for the Cr–Si–N coatings deposited under bias voltage of 0 V. When the oxidation temperature was at 800 °C, the Cr–Si–N coating was only partially oxidized. However, with the increase of oxidation temperature to 1200 °C, the surface of the coating was completely covered by the oxide generated. The results showed that the bias voltages used in multi-arc ion plating had effects on the structure, mechanical, and high temperature oxidation resistance properties of Cr–Si–N nanocomposite coatings.
Fluorinated Tolane Dyads with Alkylene Linkage: Synthesis and Evaluation of Photophysical Characteristics
Authors: Yamada Shigeyuki , Uto Eiji , Agou Tomohiro , Kubota Toshio , Konno Tsutomu
Published: August 2020

Light-emitting materials have received considerable attention because of their broad applications as substrates in bio-imaging and sensing components, light-emitting displays, and lighting devices. Herein, we developed fluorinated tolane and bistolane derivatives containing fluorinated aromatic rings and demonstrated their intense photoluminescence (PL) characteristics in crystalline powder states. We focused on molecules showing varied PL behavior with a change in the molecular aggregated structures. We synthesized novel fluorinated tolane dyads consisting of fluorinated tolane-based π-conjugated scaffolds and flexible alkylene linkages to control both the electron-density distribution and molecular aggregated states. Fluorinated tolane dyads connected with an alkylene linkage showed blue PL in a dilute solution, but the PL efficiency achieved was low. In contrast, the crystalline powder of tolane dyad substrates exhibited dual emission—relatively intense blue to deep blue PL—originating from monomer and aggregate emission. The PL behavior changed significantly with the alkylene linkage and the application of a mechanical stimulus to the crystalline powder sample. The fluorinated tolane dyads developed in this study could serve as stimulus-responsive photoluminescent materials suitable for optical applications.
An Adoptive Threshold-Based Multi-Level Deep Convolutional Neural Network for Glaucoma Eye Disease Detection and Classification
Authors: Aamir Muhammad , Irfan Muhammad , Ali Tariq , Ali Ghulam , Shaf Ahmad , S Alqahtani Saeed , Al-Beshri Ali , Alasbali Tariq , Mahnashi Mater H.
Published: August 2020

Glaucoma, an eye disease, occurs due to Retinal damages and it is an ordinary cause of blindness. Most of the available examining procedures are too long and require manual instructions to use them. In this work, we proposed a multi-level deep convolutional neural network (ML-DCNN) architecture on retinal fundus images to diagnose glaucoma. We collected a retinal fundus images database from the local hospital. The fundus images are pre-processed by an adaptive histogram equalizer to reduce the noise of images. The ML-DCNN architecture is used for features extraction and classification into two phases, one for glaucoma detection known as detection-net and the second one is classification-net used for classification of affected retinal glaucoma images into three different categories: Advanced, Moderate and Early. The proposed model is tested on 1338 retinal glaucoma images and performance is measured in the form of different statistical terms known as sensitivity (SE), specificity (SP), accuracy (ACC), and precision (PRE). On average, SE of 97.04%, SP of 98.99%, ACC of 99.39%, and PRC of 98.2% are achieved. The obtained outcomes are comparable to the state-of-the-art systems and achieved competitive results to solve the glaucoma eye disease problems for complex glaucoma eye disease cases.
The Arts and New Materialism: A Call to Stewardship through Mercy, Grace, and Hope
Authors: Leonard Nicholas
Published: August 2020

During highly polarized times, issues are quickly addressed in ways that emphasize divisions. To support the healing of our polarized culture through art, new materialist theory as presented by Karen Barad and Rosi Braidotti will be entangled with art and artmaking according to Dennis Atkinson and Makoto Fujimura to argue for art as an act of environmental and cultural stewardship, creating new possibilities and differences in the virtual that are merciful, graceful, and hopeful. To form this argument, first a summary of new materialism and ethics through Agential Realism and Affirmative Ethics is addressed. Next, a cartography including scientific and theological perspectives is presented for a diffractive reading regarding the concepts of mercy, grace, and hope to develop a new materialist understanding through a philosophy of immanence to counter the circular perpetuation of violence. These concepts are then individually addressed through the proposed new materialist framework to further break from material-discursive dualistic thought. This approach is then explored through various artworks to investigate the co-constructing material-discursive nature of art to create new relations and possibilities in the world. Finally, an in-depth study of the artworks Becoming Us by Megan Constance Altieri and Teeter-Totter Wall by Ronald Rael are addressed to detail how a new materialist approach to art that focuses on the concepts of mercy, grace, and hope can position art as an act of stewardship.
Oxidative Stress, Telomere Shortening, and Apoptosis Associated to Sarcopenia and Frailty in Patients with Multimorbidity
Authors: Bernabeu-Wittel Máximo , Gómez-Díaz Raquel , González-Molina Álvaro , Vidal-Serrano Sofía , Díez-Manglano Jesús , Salgado Fernando , Soto-Martín María , Ollero-Baturone Manuel ,   on behalf of the PROTEO RESEARCHERS
Published: August 2020

Background: The presence of oxidative stress, telomere shortening, and apoptosis in polypathological patients (PP) with sarcopenia and frailty remains unknown. Methods: Multicentric prospective observational study in order to assess oxidative stress markers (catalase, glutathione reductase (GR), total antioxidant capacity to reactive oxygen species (TAC-ROS), and superoxide dismutase (SOD)), absolute telomere length (aTL), and apoptosis (DNA fragmentation) in peripheral blood samples of a hospital-based population of PP. Associations of these biomarkers to sarcopenia, frailty, functional status, and 12-month mortality were analyzed. Results: Of the 444 recruited patients, 97 (21.8%), 278 (62.6%), and 80 (18%) were sarcopenic, frail, or both, respectively. Oxidative stress markers (lower TAC-ROS and higher SOD) were significantly enhanced and aTL significantly shortened in patients with sarcopenia, frailty or both syndromes. No evidence of apoptosis was detected in blood leukocytes of any of the patients. Both oxidative stress markers (GR, p = 0.04) and telomere shortening (p = 0.001) were associated to death risk and to less survival days. Conclusions: Oxidative stress markers and telomere length were enhanced and shortened, respectively, in blood samples of polypathological patients with sarcopenia and/or frailty. Both were associated to decreased survival. They could be useful in the clinical practice to assess vulnerable populations with multimorbidity and of potential interest as therapeutic targets.
Miles Theory Revisited with Constant Vorticity in Water of Infinite Depth
Authors: Kharif Christian , Abid Malek
Published: August 2020

The generation of wind waves at the surface of a pre-existing underlying vertically sheared water flow of constant vorticity is considered. Emphasis is put on the role of the vorticity in water on wind-wave generation. The amplitude growth rate increases with the vorticity except for quite old waves. A limit to the wave energy growth is found in the case of negative vorticity, corresponding to the vanishing of the growth rate.
Long-Term Stable 1-butyl-3-methylimidazolium Hexafluorophosphate/Ag Metal Composite Membranes for Facilitated Olefin Transport
Authors: Kang Sang
Published: August 2020

For the preparation of long-term stable ionic liquid/Ag nanoparticles composites, we compared the separation performance of 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM+BF4−)/Ag, and 1-butyl-3-methylimidazolium hexafluorophosphate (BMIM+PF6−)/Ag composite membranes with time. Separation performance showed that the BMIM+PF6−/Ag metal composite membrane was more stable than the BMIM+BF4−/Ag metal composite membrane for more than 160 h. These differences in long-term stability in BMIM+PF6−/Ag and BMIM+BF4−/Ag metal composite membranes was attributable to the phase separation between ionic liquid and nanoparticles. In particular, the phase separation between ionic liquid and silver nanoparticles was not observed with time in hydrophobic ionic liquid BMIM+PF6−, confirmed by X-ray photoelectron spectroscopy.
Influence of Annealing Temperature on Corrosion Resistance of TiO2 Nanotubes Grown on Ti–30Ta Alloy
Authors: Capellato Patricia , Sachs Daniela , Vilela Filipe Bueno , Melo Mirian M. , Silva Gilbert , Rodrigues Geovani , Zavaglia Cecilia A. de C. , Nakazato Roberto Z. , Claro Ana Paula R. A.
Published: August 2020

With little success, researchers has been searching for alloys with elements such as tantalum to improve the long-term life of implants. The Ti–30Ta alloy presents an elastic modulus E = 69 GPa that is close to that of bone (E = 17–25 GPa) than Ti cp (E = 105 GPa). In addition, nanostructure surface modification influences cell behavior and antimicrobial activity. So, this study investigates the corrosion behavior of surface modification by TiO2 nanotube grown on Ti–30Ta alloy after anodization process in the electrolyte glycerol + NH4F 0.25% at 30 V, for nine hours without annealing and annealed in 450 °C, 530 °C and 600 °C (5 °C/min). The electrochemical behavior was evaluated by three electrodes cell. The counter-electrode of graphite, reference-electrode of saturated calomel electrode and working-electrode at electrolyte of 0.15 M NaCl + 0.03 M NaF, with pH = 6 for 8000 s. The scanned region ranged from −0.8 V to values up to 3.5 V with a sweep rate 0.166 mV/s. Potentiodynamic polarization curves were obtained with a potentiostat. The sample was characterized by scanning electron microscopy (SEM) imaging, X-ray diffraction analysis (XRD) and wettability with a contact angle goniometer. We concludes from the obtained results that all treatment surfaces are hydrophilic (<90°). The surface covered with TiO2 nanotube crystallinity showed anatase phase after annealing at 450 °C, 530 °C and 600 °C; the exceptions were the anodized-without-annealing treatment and without-surface-modification alloys. The electrochemical behavior of the five groups investigated showed similar high resistance to corrosion solution under all conditions.
Particle Ejection by Jetting and Related Effects in Impact Welding Processes
Authors: Bellmann Jörg , Lueg-Althoff Jörn , Niessen Benedikt , Böhme Marcus , Schumacher Eugen , Beyer Eckhard , Leyens Christoph , Tekkaya A. Erman , Groche Peter , Wagner Martin Franz-Xaver , Böhm Stefan
Published: August 2020

Collision welding processes are accompanied by the ejection of a metal jet, a cloud of particles (CoP), or both phenomena, respectively. The purpose of this study is to investigate the formation, the characteristics as well as the influence of the CoP on weld formation. Impact welding experiments on three different setups in normal ambient atmosphere and under vacuum-like conditions are performed and monitored using a high-speed camera, accompanied by long-term exposures, recordings of the emission spectrum, and an evaluation of the CoP interaction with witness pins made of different materials. It was found that the CoP formed during the collision of the joining partners is compressed by the closing joining gap and particularly at small collision angles it can reach temperatures sufficient to melt the surfaces to be joined. This effect was proved using a tracer material that is detectable on the witness pins after welding. The formation of the CoP is reduced with increasing yield strength of the material and the escape of the CoP is hindered with increasing surface roughness. Both effects make welding with low-impact velocities difficult, whereas weld formation is facilitated using smooth surfaces and a reduced ambient pressure under vacuum-like conditions. Furthermore, the absence of surrounding air eases the process observation since exothermic oxidation reactions and shock compression of the gas are avoided. This also enables an estimation of the temperature in the joining gap, which was found to be more than 5600 K under normal ambient pressure.
The Forming Control Method of Multi-Track Laser Cladding on Curved Surface
Authors: Lian Guofu , Liu Zhaozhen , Zhang Yang , Feng Meiyan , Chen Changrong , Jiang Jibin
Published: August 2020

This paper investigated the correlation between the processing parameters and the properties of clad deposited by laser cladding on a curved surface. Mathematical models relating the processing parameters (laser power, scanning speed, gas flow, and overlap ratio) and clad properties (flatness ratio and pore area) were established by central composite design. Analysis of variance and experimental validation confirmed the validity of the models. The results indicated that the flatness ratio was negatively influenced by the larger scanning speed, gas flow, and overlap ratio, while the pore area was enlarged by the increasing of scanning speed, and increasing the overlap ratio lead to the pore area reducing at first and then increasing. Optimized processing parameters were obtained under the target of maximizing the flatness ratio and minimizing the pore area. The developed mathematical models enabled predicting the flatness ratio and pore area with optimized processing parameters. The validation experimental result verified the prediction accuracy of the models and displayed target improvement compared with the original central composite design. The results provide theoretical guidance in multi-track laser cladding on a curved surface for the prediction and control of the geometric characteristics of the coating and the optimization of the processing parameters. This research outcome provides guidance for the coating deposition application in crankshaft surface coating or surface restoration, rotary parts coating deposition, or complex shape tool manufacturing. It also forms the fundamental basis for the extensive application of multi-track laser cladding on curved substrates in the additive manufacturing industry.
Application of Historical Geophysical Materials in Searching for Cu-Ag Ore Deposits—A New Direction of Research
Authors: Speczik Stanisław , Dziewińska Lidia , Jóźwiak Waldemar , Zieliński Krzysztof
Published: August 2020

This paper presents a new instrument in geological exploration, which uses historical geophysical data for the indication of potential zones of the occurrence of Cu-Ag ore, based on the example of the newly discovered Nowa Sól deposit in south-western Poland. Basic historical seismic and gravimetric data were applied along with transformed maps. The new method of effective reflection coefficients (ERC) allowed the utilization of archival seismic records for a more precise determination of the most vaguely traced interfaces within the Permian Zechstein unit. Compared to an amplitude-based seismic section, an ERC section is characterized by its highly increased resolution of imaging. The tracing of changes in the facies and the tectonics of Zechstein sediments, particularly in a zone of their contact with Rotliegend rocks, along with the new ERC method, enabled the establishing of precise locations of prospecting boreholes. The combined use of ERC and historical well logs also allowed more precise identification of the shape of oxidized areas and the adjacent orebodies.
Hydrogen-Mediated Noncovalent Interactions in Solids: What Can NMR Crystallography Tell About?
Authors: Grosu Ioana Georgeta , Filip Xenia , Miclăuș Maria O. , Filip Claudiu
Published: August 2020

Hydrogen atoms play a crucial role in the aggregation of organic (bio)molecules through diverse number of noncovalent interactions that they mediate, such as electrostatic in proton transfer systems, hydrogen bonding, and CH–π interactions, to mention only the most prominent. To identify and adequately describe such low-energy interactions, increasingly sensitive methods have been developed over time, among which quantum chemical computations have witnessed impressive advances in recent years. For reaching the present state-of-the-art, computations had to rely on a pool of relevant experimental data, needed at least for validation, if not also for other purposes. In the case of molecular crystals, the best illustration for the synergy between computations and experiment is given by the so-called NMR crystallography approach. Originally designed to increase the confidence level in crystal structure determination of organic compounds from powders, NMR crystallography is able now to offer also a wealth of information regarding the noncovalent interactions that drive molecules to pack in a given crystalline pattern or another. This is particularly true for the noncovalent interactions which depend on the exact location of labile hydrogen atoms in the system: in such cases, NMR crystallography represents a valuable characterization tool, in some cases complementing even the standard single-crystal X-ray diffraction technique. A concise introduction in the field is made in this mini-review, which is aimed at providing a comprehensive picture with respect to the current accuracy level reached by NMR crystallography in the characterization of hydrogen-mediated noncovalent interactions in organic solids. Different types of practical applications are illustrated with the example of molecular crystals studied by our research group, but references to other representative developments reported in the literature are also made. By summarizing the major concepts and methodological progresses, the present work is also intended to be a guide to the practical potential of this relatively recent analytical tool for the scientists working in areas where crystal engineering represents the main approach for rational design of novel materials.
Ultrafine Pd Nanoparticles Supported on Soft Nitriding Porous Carbon for Hydrogen Production from Hydrolytic Dehydrogenation of Dimethyl Amine-Borane
Authors: Wen Zhaoyu , Fu Qiong , Wu Jie , Fan Guangyin
Published: August 2020

Simple and efficient synthesis of a nano-catalyst with an excellent catalytic property for hydrogen generation from hydrolysis of dimethyl amine-borane (DMAB) is a missing piece. Herein, effective and recycled palladium (Pd) nanoparticles (NPs) supported on soft nitriding porous carbon (NPC) are fabricated and applied for DMAB hydrolysis. It is discovered that the soft nitriding via a low-temperature urea-pretreatment induces abundant nitrogen-containing species on the NPC support, thus promoting the affinity of the Pd precursor and hindering the agglomeration of formed Pd NPs onto the NPC surface during the preparation process. Surface-clean Pd NPs with a diameter of sub-2.0 nm deposited on the NPC support (Pd/NPC) exhibit an outstanding catalytic performance with a turnover frequency (TOF) of 2758 h−1 toward DMAB hydrolysis, better than many previous reported Pd-based catalysts. It should be emphasized that the Pd/NPC also possesses a good stability without an obvious decrease in catalytic activity for DMAB hydrolysis in five successive recycling runs. This study provides a facile but efficient way for preparing high-performance Pd catalysts for catalytic hydrogen productions.
Foliar Application of Low Concentrations of Titanium Dioxide and Zinc Oxide Nanoparticles to the Common Sunflower under Field Conditions
Authors: Kolenčík Marek , Ernst Dávid , Urík Martin , Ďurišová Ľuba , Bujdoš Marek , Šebesta Martin , Dobročka Edmud , Kšiňan Samuel , Illa Ramakanth , Qian Yu , Feng Huan , Černý Ivan , Holišová Veronika , Kratošová Gabriela
Published: August 2020

Nano-fertilisers have only recently been introduced to intensify plant production, and there still remains inadequate scientific knowledge on their plant-related effects. This paper therefore compares the effects of two nano-fertilisers on common sunflower production under field conditions. The benefits arising from the foliar application of micronutrient-based zinc oxide fertiliser were compared with those from the titanium dioxide plant-growth enhancer. Both the zinc oxide (ZnO) and titanium dioxide (TiO2) were delivered by foliar application in nano-size at a concentration of 2.6 mg·L−1. The foliar-applied nanoparticles (NPs) had good crystallinity and a mean size distribution under 30 nm. There were significant differences between these two experimental treatments in the leaf surfaces’ trichomes diversity, ratio, width, and length at the flower-bud development stage. Somewhat surprisingly, our results established that the ZnO-NPs treatment induced generally better sunflower physiological responses, while the TiO2-NPs primarily affected quantitative and nutritional parameters such as oil content and changed sunflower physiology to early maturation. There were no differences detected in titanium or zinc translocation or accumulation in the fully ripe sunflower seeds compared to the experimental controls, and our positive results therefore encourage further nano-fertiliser research.
Jasmonate Signalling Contributes to Primary Root Inhibition Upon Oxygen Deficiency in Arabidopsis thaliana
Authors: Shukla Vinay , Lombardi Lara , Pencik Ales , Novak Ondrej , Weits Daan A. , Loreti Elena , Perata Pierdomenico , Giuntoli Beatrice , Licausi Francesco
Published: August 2020

Plants, including most crops, are intolerant to waterlogging, a stressful condition that limits the oxygen available for roots, thereby inhibiting their growth and functionality. Whether root growth inhibition represents a preventive measure to save energy or is rather a consequence of reduced metabolic rates has yet to be elucidated. In the present study, we gathered evidence for hypoxic repression of root meristem regulators that leads to root growth inhibition. We also explored the contribution of the hormone jasmonic acid (JA) to this process in Arabidopsis thaliana. Analysis of transcriptomic profiles, visualisation of fluorescent reporters and direct hormone quantification confirmed the activation of JA signalling under hypoxia in the roots. Further, root growth assessment in JA-related mutants in aerobic and anaerobic conditions indicated that JA signalling components contribute to active root inhibition under hypoxia. Finally, we show that the oxygen-sensing transcription factor (TF) RAP2.12 can directly induce Jasmonate Zinc-finger proteins (JAZs), repressors of JA signalling, to establish feedback inhibition. In summary, our study sheds new light on active root growth restriction under hypoxic conditions and on the involvement of the JA hormone in this process and its cross talk with the oxygen sensing machinery of higher plants.
Document or Lose It—On the Importance of Information Management for Genetic Resources Conservation in Genebanks
Authors: Weise Stephan , Lohwasser Ulrike , Oppermann Markus
Published: August 2020

Genebanks play an important role in the long-term conservation of plant genetic resources and are complementary to the conservation of diversity in farmers’ fields and in nature. In this context, documentation plays a critical role. Without well-structured documentation, it is not possible to make statements about the value of a resource, especially with regard to its potential for breeding and research. In particular, comprehensive information management is a prerequisite for the further development of genebank collections. This requires detailed information about the composition of a collection, thus allowing statements about which species and/or regions of origin are under-represented. This task is of strategic importance, especially due to the threats to crop plants and their wild relatives caused by advancing climate change. Both the actual conservation management and the fulfilment of legal obligations depend on information. Hence, documentation units have been established in almost all genebanks worldwide. They all face the challenge that knowledge about genebank accessions must be permanently managed and passed on across generations. International standards such as Multi-Crop Passport Descriptors (MCPD) have been established for the exchange of data between genebanks, and allow the operation of international information systems, such as the World Information and Early Warning System on Plant Genetic Resources for Food and Agriculture (WIEWS), the European Search Catalogue for Plant Genetic Resources (EURISCO) or Genesys.
Participation of Children and Parents in the Swiss Child Protection System in the Past and Present: An Interdisciplinary Perspective
Authors: Schoch Aline , Aeby Gaëlle , Müller Brigitte , Cottier Michelle , Seglias Loretta , Biesel Kay , Sauthier Gaëlle , Schnurr Stefan
Published: August 2020

As in other European countries, the Swiss child protection system has gone through substantial changes in the course of the 20th century up to today. Increasingly, the needs as well as the participation of children and parents affected by child protection interventions have become a central concern. In Switzerland, critical debates around care-related detention of children and adults until 1981 have led to the launch of the National Research Program ‘Welfare and Coercion—Past, Present and Future’ (NRP 76), with the aim of understanding past and current welfare practices. This paper is based on our research project, which is part of this national program. We first discuss three overarching concepts—integrity, autonomy and participation—at the heart of a theoretical framework in order to understand the position of parents and children in child protection proceedings. Secondly, we critically analyze the historical and legal development of the child protection system in Switzerland and its effects on children and parents from 1912 until today. Thirdly, we give an insight into the current Swiss child protection system, with an investigation of hearings of parents and children conducted by the Child and Adult Protection Authorities (CAPA) based on participant observations. In particular, we show the importance of information exchanges and of signs of mutual recognition. Finally, in light of our findings, we discuss the interplay between socio-historical and legal developments in child protection and their consequences for the integrity, autonomy and participation of the people involved.
Aspectos epidemiológicos e assistenciais de pacientes neurológicos em Unidade de Terapia Intensiva
Authors: Kássia Macêdo da Silva Bezerra Naiara , Damasceno Argolo Laize , Carolina dos Santos Lino Marília , Ramine Ramos de Souza Matos Lilian , Bento Moreira Márcia
Published: August 2020

Lesões neurológicas resultam em incapacidade grave mundialmente, neurocríticos geralmente apresentam estado geral grave e necessitam de cuidados intensivos logo no início da lesão. A frequência com que são internados e suas evoluções são pouco conhecidas. Salientar peculiaridades regionais é importante para estabelecer prognóstico e medidas intervencionistas nessa população. Objetivou-se analisar os desfechos clínicos e epidemiológicos de pacientes neurocríticos de um hospital universitário, referência de atendimento da região do submédio Vale do São Francisco. Trata-se de um estudo transversal de abordagem exploratória com dados de prontuários de pacientes neurocríticos internados em um hospital universitário em Petrolina no período de janeiro de 2018 a outubro de 2018. As variáveis estudadas foram processadas e analisadas utilizando o programa Statistical Package for the Social Science (SPSS). Os resultados descritos estão relacionados às características epidemiológicas e principais indicadores de assistência ao neurocrítico, onde predominou a população do sexo masculino e adultos-jovem. As principais causas de internação foram o traumatismo cranioencefálico, hematomas cerebrais e acidente vascular encefálico. O tempo médio de internação foi de 12 dias e o tempo de assistência ventilatória mecânica foi de 11 dias. O conhecimento desses dados é fundamental para aperfeiçoar o atendimento ao paciente neurocrítico. Espera-se enriquecer a comunidade cientifica com as informações do perfil traçado e orientar políticas de saúde e estratégias para melhorar o cuidado dos pacientes neurocríticos.
A Sparse Topic Model for Bursty Topic Discovery in Social Networks
Authors: Shi Lei , Du Junping , Kou Feifei
Published: August 2020

Bursty topic discovery aims to automatically identify bursty events and continuously keep track of known events. The existing methods focus on the topic model. However, the sparsity of short text brings the challenge to the traditional topic models because the words are too few to learn from the original corpus. To tackle this problem, we propose a Sparse Topic Model (STM) for bursty topic discovery. First, we distinguish the modeling between the bursty topic and the common topic to detect the change of the words in time and discover the bursty words. Second, we introduce “Spike and Slab” prior to decouple the sparsity and smoothness of a distribution. The bursty words are leveraged to achieve automatic discovery of the bursty topics. Finally, to evaluate the effectiveness of our proposed algorithm, we collect Sina weibo dataset to conduct various experiments. Both qualitative and quantitative evaluations demonstrate that the proposed STM algorithm outperforms favorably against several state-of-the-art methods
Assessing Polycystic Kidney Disease in Rodents: Comparison of Robotic 3D Ultrasound and Magnetic Resonance Imaging
Authors: Beaumont Nathan J. , Holmes Heather L. , Gregory Adriana V. , Edwards Marie E. , Rojas Juan D. , Gessner Ryan C. , Dayton Paul A. , Kline Timothy L. , Romero Michael F. , Czernuszewicz Tomasz J.
Published: August 2020

Polycystic kidney disease (PKD) is an inherited disorder characterized by renal cyst formation and enlargement of the kidney. PKD severity can be staged noninvasively by measuring total kidney volume (TKV), a promising biomarker that has recently received regulatory qualification. In preclinical mouse models, where the disease is studied and potential therapeutics are evaluated, the most popular noninvasive method of measuring TKV is magnetic resonance imaging (MRI). Although MRI provides excellent 3D resolution and contrast, these systems are expensive to operate, have long acquisition times, and, consequently, are not heavily used in preclinical PKD research. In this study, a new imaging instrument, based on robotic ultrasound (US), was evaluated as a complementary approach for assessing PKD in rodent models. The objective was to determine the extent to which TKV measurements on the robotic US scanner correlated with both in vivo and ex vivo reference standards (MRI and Vernier calipers, respectively). A cross-sectional study design was implemented that included both PKD-affected mice and healthy wild types, spanning sex and age for a wide range of kidney volumes. It was found that US-derived TKV measurements and kidney lengths were strongly associated with both in vivo MRI and ex vivo Vernier caliper measurements (R
2=0.94 and 0.90, respectively). In addition to measuring TKV, renal vascular density was assessed using acoustic angiography (AA), a novel contrast-enhanced US methodology. AA image intensity, indicative of volumetric vascularity, was seen to have a strong negative correlation with TKV (R
2=0.82), suggesting impaired renal vascular function in mice with larger kidneys. These studies demonstrate that robotic US can provide a rapid and accurate approach for noninvasively evaluating PKD in rodent models.
Abdullah Safi'nin Akif Paşa'ya Ait "Adem" Kasidesine Yazdığı Nakize
Authors: KAZANCI Mehmet Ömer
Published: August 2020

Abdullah Safi (1809-1898) Irak Türkmen şairleri arasında görkemli bir konuma sahip olan bir şairdi. Nesir konusunda da üstat olduğu bilinmektedir. Hatta bazı edebiyat tarihçilerine göre nesrinin nazmından daha üstün olduğu değerlendirilmektedir. Şiirin her türünü denemiştir. Bunlar arasında gazel, kaside ve tarih düşürme manzumeleri çoğunluğu oluşturur. Kasidelerinden biri, Akif Paşa'nın "Adem Kasidesi"ne yazmış olduğu "nakize"dir. Günümüze kadar her hangi bir kaynakta adına işaret edilmeyen bu kaside, gerek içerik, gerekse de teknik bakımından Safi'nin üst düzey bir şair olduğunu gösteren önemli eserlerinden biridir. 47 beyitten oluşan kasidenin metninde yer yer tasavvuf kavramlarının kullanılmış olduğu gözlerden kaçmamaktadır. Kasidenin metnini ilk olarak edebiyat dünyasına sunarken, tahlilini, şerhini ve estetik değerini divan edebiyatı uzmanlarımıza bırakıyoruz
XVI. Yüzyıl Şairlerinden Hakkânî’nin Cevâhir Adlı Mesnevisi
Authors: KURT Halil
Published: August 2020

Kanunî Sultan Süleyman devri şairlerinden Hakkânî’nin Cevâhir adlı mesnevisinin ortaya çıkarılması ve ilim âlemine tanıtılması çalışmamızın esas konusunu teşkil etmektedir.Yaptığımız araştırmalar sonucunda XVI. yüzyıla dair bilgi veren tezkire ve edebiyat tarihi türü eserlerde Hakkânî mahlaslı şair veya şairlere tesadüf edemedik. Bu sebeple Hakkânîʾnin hayatı hakkında şimdiye kadar fazla bir malumat elde edemedik. Fakat Hakkânîʾnin daha önce tespit edilmiş olan Manzume-i Nasayih Ala Meşrebi’t-Tasavvuf adlı eseri ile elimizdeki Cevâhir adlı mesneviden hareketle onun hakkında sınırlı da olsa birtakım bilgilere ancak ulaşabilmekteyiz. Makalemize konu olan Hakkânîʾnin Cevâhir adlı mesnevisinin bilinen tek nüshası İstanbul Millet Kütüphanesi, Ali Emiri Koleksiyonu 34 Ae Manzum 908/1 künyesiyle kayıtlıdır. Harekeli nesih hattı ile yazılmış olan metin, baştan veya sondan eksik olmayan bir mecmuanın içerisinde birinci bölümde yer almaktadır. Mecmuanın ikinci bölümünde ise Kitab-ı Monla İlahî metni bulunmaktadır. Hakkânî, eserini Kanunî Sultan Süleyman’a takdim etmek üzere yazmıştır. Zira eserde Kanunî’ye övgü, ona dua ve nasihat bölümleri söz konusudur. Dinî-tasavvufi bir nasihatname özelliği taşıyan bu mesnevi, beş yüz kırk beyitten meydana gelmektedir. Hakkânî, Cevahirʾin giriş bölümünü; tevhit, münacat ve naat konulu beyitlere ayırmıştır. Sonra din ve tasavvuf konularından bahseder. Akabinde Sultan Süleyman’a övgü ve öğüt bölümleri gelir. Türk dili ve edebiyatı açısından zengin olan bu eser, dönemin edebi hayatı hakkında ipuçları vermesi bakımından önemlidir. Bu makalede Cevâhir üzerinde yapılan incelemenin ardından eserin çeviri yazı metni neşredilmiştir.