bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimization of polycaprolactone - based nanofiber matrices for the cultivation of corneal endothelial cells
Authors: Himmler Marcus , Garreis Fabian , Paulsen Friedrich , Schubert Dirk W. , Fuchsluger Thomas A. 
Published: September 2021

AbstractPosterior lamellar transplantation of the eye’ s cornea (DSAEK, DMEK) currently is the gold standard for treating patients with corneal endothelial cell and back surface pathologies resulting in functional impairment. An artificial biomimetic graft carrying human corneal endothelium could minimize the dependency on human donor corneas giving access to this vision-restoring surgery to large numbers of patients, thus reducing current long waiting lists. In this study, four groups of electrospun nanofibrous scaffolds were compared: polycaprolactone (PCL), PCL/collagen, PCL/gelatin and PCL/chitosan. Each of the scaffolds were tissue-engineered with human corneal endothelial cells (HCEC-B4G12) and analyzed with regard to their potential application as artificial posterior lamellar grafts. Staining with ZO-1 and Na+/K+-ATPase antibodies revealed intact cell functionalities. It could be shown, that blending leads to decreasing contact angle, whereby a heterogeneous blend morphology could be revealed. Scaffold cytocompatibility could be confirmed for all groups via live/dead staining, whereby a significant higher cell viability could be observed for the collagen and gelatine blended matrices with 97 ± 3% and 98 ± 2% living cells respectively. TEM images show the superficial anchoring of the HCECs onto the scaffolds. This work emphasizes the benefit of blended PCL nanofibrous scaffolds for corneal endothelial keratoplasty.
Multiyear trend in reproduction underpins interannual variation in gametogenic development of an Antarctic urchin
Authors: De Leij Rebecca , Peck Lloyd S. , Grange Laura J. 
Published: September 2021

AbstractEcosystems and their biota operate on cyclic rhythms, often entrained by predictable, small-scale changes in their natural environment. Recording and understanding these rhythms can detangle the effect of human induced shifts in the climate state from natural fluctuations. In this study, we assess long-term patterns of reproductive investment in the Antarctic sea urchin, Sterechinus neumayeri, in relation to changes in the environment to identify drivers of reproductive processes. Polar marine biota are sensitive to small changes in their environment and so serve as a barometer whose responses likely mirror effects that will be seen on a wider global scale in future climate change scenarios. Our results indicate that seasonal reproductive periodicity in the urchin is underpinned by a multiyear trend in reproductive investment beyond and in addition to, the previously reported 18–24 month gametogenic cycle. Our model provides evidence that annual reproductive investment could be regulated by an endogenous rhythm since environmental factors only accounted for a small proportion of the residual variation in gonad index. This research highlights a need for multiyear datasets and the combination of biological time series data with large-scale climate metrics that encapsulate multi-factorial climate state shifts, rather than using single explanatory variables to inform changes in biological processes.
Comparison of DNA and RNA sequencing of total nucleic acids from human cervix for metagenomics
Authors: Arroyo Mühr Laila Sara , Dillner Joakim , Ure Agustin Enrique , Sundström Karin , Hultin Emilie 
Published: September 2021

AbstractAlthough metagenomics and metatranscriptomics are commonly used to identify bacteria and viruses in human samples, few studies directly compare these strategies. We wished to compare DNA and RNA sequencing of bacterial and viral metagenomes and metatranscriptomes in the human cervix. Total nucleic acids from six human cervical samples were subjected to DNA and RNA sequencing. The effect of DNase-treatment before reverse transcription to cDNA were also analyzed. Similarities and differences in the metagenomic findings with the three different sequencing approaches were evaluated. A higher proportion of human sequences were detected by DNA sequencing (93%) compared to RNA sequencing without (76%) and with prior DNase-treatment (11%). On the contrary, bacterial sequences increased 17 and 91 times. However, the number of detected bacterial genera were less by RNA sequencing, suggesting that only a few contribute to most of the bacterial transcripts. The viral sequences were less by RNA sequencing, still twice as many virus genera were detected, including some RNA viruses that were missed by DNA sequencing. Metatranscriptomics of total cDNA provided improved detection of mainly transcribed bacteria and viruses in cervical swabs as well as detection of RNA viruses, compared to metagenomics.
Monitoring the size of low-intensity beams at plasma-wakefield accelerators using high-resolution interferometry
Authors: Hwang Ji-Gwang , Albrecht Katharina , Hoehl Arne , Alberdi Esuain Beñat , Kamps Thorsten 
Published: September 2021

AbstractPlasma-based accelerators are on the brink of a development stage, where applications of the beam for medical sciences, imaging, or as an injector for a future large-scale accelerator-driven light source become feasible. The requirements on electron beams for injection into a storage-ring are stringent regarding beam quality and reliability. Here, we propose a beam diagnostic technique for measuring lateral beam sizes with a few-μm resolution by applying a state-of-art single-photon camera to coherent synchrotron radiation that affords by a sub-femtosecond short bunch-length property. A sophisticated image processing algorithm enables the technique down to 5 photons/pixel for the visibility of 0.132. Results show the potential of the proposed system that achieves precise retrieval of the complex degree of coherence at an extremely low photon intensity similar to those expected towards the plasma-acceleration injectors.
Joint optimization of antenna selection and beamforming in MIMO SWIPT systems with bidirectional communication
Authors: Hedayati Mohammadali , Yousefi Shahram 
Published: September 2021

AbstractThis paper investigates joint optimization of antenna selection and beamforming in multiple‐input multiple‐output simultaneous wireless information and power transfer systems with bidirectional communication. The downlink–uplink rate region is used as the performance metric. The formulated optimization problem is non‐convex mixed integer programming, which is challenging to solve. The problem is first converted into a form of a quadratically constrained quadratic program. Given fixed receive and transmit antenna sets at the energy harvesting device, the authors apply the semidefinite relaxation to obtain a convex problem for optimal beamforming which can be solved efficiently. It is proved that the semidefinite relaxation is tight. The authors solve the relaxed problem for every possible receive and transmit antenna sets and find the optimal solution by search. Moreover, a low‐complexity method to alleviate the computational complexity of the optimal solution by deriving effective heuristic algorithms for the beamforming and antenna selection is proposed. Simulation results demonstrate that both the optimal and the low‐complexity algorithms outperform the benchmark power splitting, when the circuit power consumption is sufficiently high or the number of receive antennas at the energy harvesting device is sufficiently large. Also, a near‐optimal performance can be achieved by the proposed low‐complexity method.
Synchronisation of multiple neural networks via event‐triggered time‐varying delay hybrid impulsive control
Authors: Ruan Xiaoli , Xu Chen , Feng Jianwen , Wang Jingyi , Zhao Yi 
Published: September 2021

AbstractThis article discusses the exponential synchronisation problem for multiple neural networks with time‐varying delay and a more general non‐Laplacian coupling matrix is considered. To reduce the redundant communication, two event‐based time‐varying delay hybrid impulsive control schemes are proposed with static event‐triggered condition and dynamic event‐triggered condition. These novel control schemes neatly combine the event‐triggered coupling strategy with the time‐varying delay hybrid impulsive control, where the impulsive instant is only determined by the specified event‐triggered condition. Moreover, a delay impulsive differential inequality is established to discuss the synchronisation problem for controlled multiple neural networks. By using Stolz's theorem and introducing the average event‐triggered delay impulsive gain, some less conservative sufficient conditions are derived to assure the stability of the time‐varying delay multiple neural networks. Furthermore, the Zeno behaviour can be eliminated effectively and the consumption of the computing resources can be reduced. Finally, some examples are given to verify the superiority of the results.First, a static event‐triggered time‐varying delay hybrid impulsive control scheme was proposed to lessen the communication burden. Then, a time‐varying delay impulsive differential inequality was established to guarantee the synchronisation of multiple neural networks. Moreover, the authors also discussed the issue that continuously triggering and sampling can be excluded.
Optimal configuration of energy storage capacity in wind farms based on cloud energy storage service
Authors: Chen Ting , Yang Junjie , Jiang Wei , Sui Zhicheng , Wang Yujie 
Published: September 2021

AbstractIn wind farms, the energy storage system can realize the time and space transfer of energy, alleviate the intermittency of renewable energy and enhance the flexibility of the system. However, the high cost limits its large‐scale application. Cloud energy storage (CES) can provide users with leasing energy storage service at a relatively lower price, and can provide energy trading service. Wind farms can lease CES and participate in energy transaction to reduce the cost of energy storage and suppress wind power fluctuations. This paper proposes a framework of wind farm system based on CES service, and designs a power allocation strategy. Considering whole‐life‐cycle cost of the self‐built energy storage, leasing and trading cost of the CES and penalty cost of wind abandonment and smooth power shortage, an optimal configuration model of combined energy storage capacity in wind farms based on CES service was established to minimize the total annual cost. Taking a wind farm in Germany as a case study, it is verified that the model in this paper can effectively reduce the cost, extend the service life of self‐built energy storage equipment and suppress the wind power fluctuations.
Abscisic acid stimulates wound suberisation in kiwifruit (Actinidia chinensis) by regulating the production of jasmonic acid, cytokinin and auxin
Authors: Wei Xiaobo , Wei Xiaopeng , Guan Weiliang , Mao Linchun 
Published: September 2021

Wounding induces a cascade of correlative physiological responses that lead to the repair of damaged tissue. In this study, the effect of wounding on suberin, endogenous hormones and their metabolic genes expression was observed during the wound healing of kiwifruit (Actinidia chinensis Planch.). In addition, the role of abscisic acid (ABA) in wound suberisation was investigated by analysing the coordinated regulation between ABA and other hormones. The wound healing process in kiwifruit could be divided into two stages including: (1) initial accumulation of suberin polyphenolic (SPP) and long carbon chain suberin polyaliphatic monomers (LSPA) before 24 h; and (2) massive synthesis of SPP and very long carbon chain suberin polyaliphatic monomers (VLSPA) after 24 h. ABA content rapidly increased and induced the jasmonic acid (JA) biosynthesis at the early stage of wound healing. ABA level gradually decreased with the expression of AchCYP707A genes, while the contents of trans-zeatin (t-ZT) and indole-3-acetic acid (IAA) steadily increased at the late stage of wound healing. Exogenous ABA stimulated JA and suberin monomers accumulation, but suppressed both t-ZT and IAA biosynthesis. The role of ABA in wound healing of kiwifruit might be involved in the coordination of both JA-mediated suberin monomers biosynthesis and t-ZT- and IAA-mediated formation of suberised cells via an interaction mechanism.
Vacuum-gap-based lumped element Josephson parametric amplifier
Authors: Wu Sishi , Zhang Dengke , Wang Rui , Liu Yulong , Wang Shuai-Peng , Liu Qichun , Tsai J S , Li Tiefu 
Published: September 2021

Abstract
We propose a lumped element Josephson parametric amplifier with vacuum-gap-based capacitor. The capacitor is made of quasi-floating aluminum pad and on-chip ground. We take a fabrication process compatible with air-bridge technology, which makes our design adaptable for future on-chip integrated quantum computing system. Further engineering the input impedance, we obtain a gain above 20 dB over 162-MHz bandwidth, along with a quasi quantum-limit noise performance. This work should facilitate the development of quantum information processing and integrated superconducting circuit design.
Microstructure evolution of Cu-Fe-based immiscible alloys prepared by powder metallurgy
Authors: Adam O , Jan V 
Published: September 2021

Abstract
The work is focused on the preparation of bulk immiscible Cu-Fe-based alloys by powder metallurgy. Three samples with chemical composition Cu70Fe30, Cu70Fe15Co15, and Cu50Fe25Co25 were prepared by mechanical alloying and spark plasma sintering (SPS). Microstructure evolution during sintering and the effect of Co on the resulting microstructure and hardness of the bulk samples were evaluated. Despite the immiscibility of Cu with Fe and Co, the FCC supersaturated solid solution was formed upon mechanical alloying. This supersaturated solid solution was decomposed during SPS and fine microstructure, consisting of separated BCC and FCC phases, was formed. The results showed that cobalt influenced the particle size of milled powders as the particle size of Cu70Fe30 alloy was about an order of magnitude higher compared to other alloys. Cobalt also affected the resulting microstructure of bulk samples, however, its effect on the hardness was negligible. It has been shown that powder metallurgy can be used for the preparation of bulk immiscible alloys with the fine microstructure consists of separate phases, which can be individually alloyed by the selected elements, and therefore, powder metallurgy can be considered as a suitable alternative to the more used casting.
Influence of processing parameters and heat input level on the functional properties of atmospheric plasma sprayed Al2O3-3TiO2 commercial coating
Authors: Antoš J , Lencová K , Keslová A 
Published: September 2021

Abstract
This paper concerns the combined influence of spraying parameters and heat flux level during atmospheric plasma spraying process of commercial alumina-titania coating. One of the main industrial application of alumina-titania are wear and abrasion resistant protective thermally sprayed coatings. Commercial high throughput plasma torch with cascaded construction is used as the spraying equipment. Three sets of spraying parameters were used for the basic evaluation of their influence. Additionally, three levels of heat input during spraying process were added to some of those sets of parameters. Those heat input levels are called “cold”, “hot” and “extra hot” depending on the relative amount of direct heat input and maximum achieved surface temperature. Comparison of surface hardness, microstructure and especially abrasion resistance is carried out. Results confirmed that for successful design of such ceramic coatings, appropriate and sufficient heat input during spraying process into the complex of layer-substrate is required.
Analysis of structure and properties of multilayer polymer foil
Authors: Bilewicz Marcin 
Published: September 2021

Abstract
Light and cheap composites are the main goal of manufacturing in many branches. Polymers, containing low weight and high relative strength, are suitable materials as matrix of composites reinforced with different metallic or ceramic fillers in the shape of fibres, plates, blocks or other types. This work takes into consideration optimisation and manufacturing of multilayer foil with different composition. To obtain the film has been used advanced blow molding process equipped with three extruders feeding material to the machine. Feeding of material is precisely controlled through gravimetric dosimeters. Final product of this technology is the polymer film which is obtained as combination of three films adherent together in the advanced head of blow molding machine.
Analysis of deformation mechanisms in a textured AZ31 magnesium alloy
Authors: Dittrich J , Čapek J , Knapek M , Minárik P 
Published: September 2021

Abstract
A combination of advanced in-situ and ex-situ methods providing complementary information was employed in order to reveal the active deformation mechanisms during deformation of a heavily textured commercial magnesium alloy AZ31. Three sets of samples for both compression and tension testing were prepared from the rolled sheet with respect to its identified strong basal texture – normal direction (ND), rolling direction (RD) and 45° between RD and ND. During both compressive and tensile deformation of these samples, the signal of acoustic emission (AE) was concurrently measured. Afterwards, electron backscattered diffraction (EBSD) was used to study the microstructure after the selected stages of deformation. The EBSD analysis revealed that in the samples favourably oriented for extension twinning it played an important role during the plastic deformation, whereas its role in the unfavourably oriented samples was minor. This orientation and deformation mode dependency of extension twinning activation resulted in considerable differences in the deformation behaviour, which also influenced the AE response. A consistent link between the AE signal and the microstructural changes investigated by EBSD was established. Furthermore, to study the dynamics of plastic deformation and twin growth, high-speed camera footage of the sample surface was captured during compressive deformation. The obtained results were in complete accordance with the predicted behaviour, thus providing direct proof of the theory and extending the understanding of the deformation mechanisms.
Creep behaviour of ultrafine-grained CP titanium processed by multi-pass rolling
Authors: Dvorak J. , Kadomtsev A.G. , Betekhtin V.I. , Sklenicka V. , Kral P. , Kvapilova M. 
Published: September 2021

Abstract
Two commercially pure (CP) Ti heats containing the same total impurity content have been used under investigation. Both materials were subjected to the processing procedure method of severe plastic deformation (SPD). This procedure consists of two steps of hot rolling (at 673 K) and the final rolling step at ambient temperature. The difference in individual chemical contents of impurities resulted in two states, both with ultrafine-grained (UFG) microstructures. For comparison reason, coarse-grained (CG) state was prepared by annealing of UFG state at temperature 823 K/1h. Microstructure investigations were performed using scanning electron microscope equipped with EBSD unit (SEM/EBSD) and transmission electron microscopy (TEM). Constant load tensile creep tests were conducted at temperature 673 K and applied uniaxial stress of 200MPa. Creep tests were run up to the final fracture of the creep specimens. The main objective of this work was to evaluate how the synergistic effect of SPD and the resulting microstructure affects the creep behaviour and properties of the studied materials.
Impact of semi-solid processing and cryogenic treatment on wear resistance of X210Cr12 tool steel
Authors: Hradil D , Duchek M , Jirková H , Rubešová K. 
Published: September 2021

Abstract
Semi-solid processing is type of process where metastable microstructure with carbide network may be obtained. Metastable austenite is embedded in carbide-austenite network even in ordinary tool steels. The paper describe semi-solid processing of the ledeburitic steel X210Cr12, with 2% carbon and 12% chromium. The semi-solid processing temperature was 1250 °C with dwell time 60 minutes. Two states for comparison were evaluated, with or without subsequent deformation. Another process used in this study is cryogenic treatment. Cryogenic treatment defined as an add-on process to conventional heat treatment, during which the material is brought to a temperature close to the liquid nitrogen temperature. The cryogenic treatment were used in this study for improving and comparing of impact on wear resistance combined with semi-solid processing. Wear resistance were evaluated based on pin-on-disc testing at ambient temperature.
Investigation of mechanical properties of secondary AlSi7Mg0.3 cast alloys before and after corrosion
Authors: Kuchariková L , Tillová E , Švecová I , Liptáková T. 
Published: September 2021

Abstract
The casting industry currently use about 35% of secondary (recycled) aluminum and about 65% of primary aluminum to meet their needs. The manufacturer wants to use the secondary aluminum alloys more and more, but these materials have the higher amount of the undesirable elements. The most negative element in such alloys is Fe. Although the corrosion current increased due to the presence of alloying elements in the matrix of aluminum alloys, the higher content of Fe (which led to increasing amount of Fe-rich phases) could affect the corrosion resistance. The basic metallography assessment of experimental materials microstructure confirm the higher amount of Fe-rich phases in secondary alloys. The results of mechanical properties shows that the higher content of Fe (also Fe-rich phases) does not lead to decreasing the mechanical properties. The similar results of mechanical properties were reached after corrosion attack with 3.5 wt. % NaCl. The assessment of corrosion attack confirmed the presence of pitting corrosion on experimental samples, which increase with increasing Fe content.
The influence of the temperature on the mechanical properties of Sanicro 25 steel
Authors: Sroka M 
Published: September 2021

Abstract
Austenitic steel 22Cr25NiWCoCu (Sanicro 25) is one of the newest and most promising steels for use in supercritical and ultra-supercritical power units. High resistance of Sanicro 25 steel to corrosion and oxidation in the steam atmosphere at up to 700 °C is ensured by chromium content at 21.5-23.5 wt%. Also, higher chromium content provides less mass decrement during high-temperature corrosion at 700 °C. Currently, the Sanicro 25 steel is characterised by the highest creep strength among the commercially used creep-resistant stainless steels. In this work, the study of precipitation processes and microstructure stability in the delivery state and after the ageing process in time up to 20,000 h at 750 °C was performed. Identification of secondary phases was performed using electron diffraction on thin films using transmission electron microscopy and X-ray phase composition analysis. Long-term ageing depending on time and temperature showed that there are four secondary phases in Sanicro 25: M23C6, MX, NbCrN, σ-phase and Cu_rich. The precipitation and increase in the size of secondary phase particles during ageing results in a decrease in matrix saturation with alloying elements, which leads to a reduction in hardening by solid solution mechanism. These processes and effects result in changes in mechanical properties. The alloy overageing effect observed for the ageing temperature of 750 °C results in obtaining strength properties similar to those of the steel in the as-received condition.