bluuebunny/crossref_metadata_2025 huggingface dataset:
Machine learning approach to integrated endometrial transcriptomic datasets reveals biomarkers predicting uterine receptivity in cattle at seven days after estrous
Authors: Rabaglino Maria B. , Kadarmideen Haja N.
Published: October 2020

The main goal was to apply machine learning (ML) methods on integrated multi-transcriptomic data, to identify endometrial genes capable of predicting uterine receptivity according to their expression patterns in the cow. Public data from five studies were re-analyzed. In all of them, endometrial samples were obtained at day 6–7 of the estrous cycle, from cows or heifers of four different European breeds, classified as pregnant (n = 26) or not (n = 26). First, gene selection was performed through supervised and unsupervised ML algorithms. Then, the predictive ability of potential key genes was evaluated through support vector machine as classifier, using the expression levels of the samples from all the breeds but one, to train the model, and the samples from that one breed, to test it. Finally, the biological meaning of the key genes was explored. Fifty genes were identified, and they could predict uterine receptivity with an overall 96.1% accuracy, despite the animal’s breed and category. Genes with higher expression in the pregnant cows were related to circadian rhythm, Wnt receptor signaling pathway, and embryonic development. This novel and robust combination of computational tools allowed the identification of a group of biologically relevant endometrial genes that could support pregnancy in the cattle.
Origin of enhanced chemical precompression in cerium hydride $$\hbox {CeH}_{{9}}$$
Authors: Jeon Hyunsoo , Wang Chongze , Yi Seho , Cho Jun-Hyung
Published: October 2020

The rare-earth metal hydrides with clathrate structures have been highly attractive because of their promising high-$$T_{\rm{c}}$$

T
c

superconductivity at high pressure. Recently, cerium hydride $$\hbox {CeH}_9$$

CeH
9

composed of Ce-encapsulated clathrate H cages was synthesized at much lower pressures of 80–100 GPa, compared to other experimentally synthesized rare-earth hydrides such as $$\hbox {LaH}_{{10}}$$

LaH
10

and $$\hbox {YH}_6$$

YH
6

. Based on density-functional theory calculations, we find that the Ce 5p semicore and 4f/5d valence states strongly hybridize with the H 1s state, while a transfer of electrons occurs from Ce to H atoms. Further, we reveal that the delocalized nature of Ce 4f electrons plays an important role in the chemical precompression of clathrate H cages. Our findings not only suggest that the bonding nature between the Ce atoms and H cages is characterized as a mixture of ionic and covalent, but also have important implications for understanding the origin of enhanced chemical precompression that results in the lower pressures required for the synthesis of $$\hbox {CeH}_9$$

CeH
9

.
A porous collagen-based hydrogel and implantation method for corneal stromal regeneration and sustained local drug delivery
Authors: Xeroudaki Maria , Thangavelu Muthukumar , Lennikov Anton , Ratnayake Anjula , Bisevac Jovana , Petrovski Goran , Fagerholm Per , Rafat Mehrdad , Lagali Neil
Published: October 2020

Biomaterials designed to replace the diseased cornea could be used to treat corneal blindness where human donor tissue is in short supply, but challenges are the integration of biomaterials with host tissue and cells, avoiding a rapid material degradation and maintaining corneal transparency. Additionally, implantation surgery often triggers an aggressive wound healing response that can lead to corneal thinning and opacity. Here, we report a collagen-based hydrogel with transparency and mechanical properties suitable for replacing a substantial portion of a damaged or diseased corneal stroma. The porous hydrogel permitted migration and population by host cells while maintaining transparency and thickness six months after surgical implantation in an in vivo model of human corneal surgery. With a novel hybrid surgical implantation technique inspired by LASIK refractive surgery, rapid wound healing occurred around implants to maintain biomaterial integrity, transparency and function. Host stromal cell repopulation and regeneration of host epithelium and nerves were observed, as necessary steps towards corneal regeneration. Finally, as a proof-of-principle, the hydrogel loaded with a neuroregenerative drug achieved sustained slow-release drug delivery in vitro. The proposed hydrogel and novel implantation technique together represent a therapeutic approach with translational potential for replacing and regenerating diseased corneal stromal tissue.
Association between free-living sleep and memory and attention in healthy adolescents
Authors: Stefansdottir Runa , Gundersen Hilde , Rognvaldsdottir Vaka , Lundervold Alexander S. , Gestsdottir Sunna , Gudmundsdottir Sigridur L. , Chen Kong Y. , Brychta Robert J. , Johannsson Erlingur
Published: October 2020

In laboratory studies, imposed sleep restriction consistently reduces cognitive performance. However, the association between objectively measured, free-living sleep and cognitive function has not been studied in older adolescents. To address this gap, we measured one week of sleep with a wrist-worn GT3X+ actigraph in 160 adolescents (96 girls, 17.7 ± 0.3 years) followed by assessment of working memory with an n-back task and visual attention with a Posner cue-target task. Over the week, participants spent 7.1 ± 0.8 h/night in bed and slept 6.2 ± 0.8 h/night with 88.5 ± 4.8% efficiency and considerable intra-participant night-to-night variation, with a standard deviation in sleep duration of 1.2 ± 0.7 h. Sleep measures the night before cognitive testing were similar to weekly averages. Time in bed the night before cognitive testing was negatively associated with response times during the most challenging memory task (3-back; p = 0.005). However, sleep measures the night before did not correlate with performance on the attention task and weekly sleep parameters were not associated with either cognitive task. Our data suggests shorter acute free-living sleep may negatively impact difficult memory tasks, however the relationship between free-living sleep and cognitive task performance in healthy adolescents is less clear than that of laboratory findings, perhaps due to high night-to-night sleep variation.
Lacticaseibacillus casei AMBR2 modulates the epithelial barrier function and immune response in a donor-derived nasal microbiota manner
Authors: De Rudder Charlotte , Garcia-Tímermans Cristina , De Boeck Ilke , Lebeer Sarah , Van de Wiele Tom , Calatayud Arroyo Marta
Published: October 2020

Live biotherapeutic products (LBP) are emerging as alternative treatment strategies for chronic rhinosinusitis. The selection of interesting candidate LBPs often involves model systems that do not include the polymicrobial background (i.e. the host microbiota) in which they will be introduced. Here, we performed a screening in a simplified model system of upper respiratory epithelium to assess the effect of nasal microbiota composition on the ability to attach and grow of a potential LBP, Lacticaseibacillus casei AMBR2, in this polymicrobial background. After selecting the most permissive and least permissive donor, L. casei AMBR2 colonisation in their respective polymicrobial backgrounds was assessed in more physiologically relevant model systems. We examined cytotoxicity, epithelial barrier function, and cytokine secretion, as well as bacterial cell density and phenotypic diversity in differentiated airway epithelium based models, with or without macrophage-like cells. L. casei AMBR2 could colonize in the presence of both selected donor microbiota and increased epithelial barrier resistance in presence of donor-derived nasal bacteria, as well as anti-inflammatory cytokine secretion in the presence of macrophage-like cells. This study highlights the potential of L. casei AMBR2 as LBP and the necessity to employ physiologically relevant model systems to investigate host–microbe interaction in LBP research.
Direct currents stimulate carbonate mineralization for soil improvement under various chemical conditions
Authors: Terzis Dimitrios , Hicher Patrick , Laloui Lyesse
Published: October 2020

The present study integrates direct electric currents into traditional calcium carbonate mineralization to investigate electrochemical interactions and the subsequent crystalline growth of CaCO3bonds in sand. A specific line of focus refers to the effect of three chemical reactive species involved in the stimulated geo-chemo-electric system, namely CaCl2, Ca(CH3COO)2and Ca(CH3CH2(OH)COO)2. By altering treatment conditions and the applied electric field, we capture distinctive trends related to the: (i) overall reaction efficiencies and distribution of CaCO3crystals is sand samples; (ii) promotion of CaCO3mineralization due to DC (iii) crystallographic and textural properties of mineralized bonds. The study introduces the concept of EA-MICP which stands for Electrically Assisted Microbially Induced Carbonate Precipitation as a means of improving the efficiency of soil bio-cementation compared to traditional MICP-based works. Results reveal both the detrimental and highly beneficial effects that electric currents can hold in the complex, reactive and transport processes involved. An interesting observation refers to the “doped” morphology of CaCO3crystals, which precipitate under electric fields, validated by crystallographic analyses and microstructural observations.
Preparation, characterisation and biological evaluation of biopolymer-coated multi-walled carbon nanotubes for sustained-delivery of silibinin
Authors: Tan Julia Meihua , Bullo Saifullah , Fakurazi Sharida , Hussein Mohd Zobir
Published: October 2020

This research work represents the first major step towards constructing an effective therapeutic silibinin (SB) in cancer treatment using oxidised multi-walled carbon nanotubes (MWCNT-COOH) functionalised with biocompatible polymers as the potential drug carrier. In an attempt to increase the solubility and dispersibility of SB-loaded nanotubes (MWSB), four water-soluble polymers were adopted in the preparation process, namely polysorbate 20 (T20), polysorbate 80 (T80), polyethylene glycol (PEG) and chitosan (CHI). From the geometry point of view, the hydrophobic regions of the nanotubes were loaded with water-insoluble SB while the hydrophilic polymers functionalised on the outer surfaces of the nanotubes serve as a protective shell to the external environment. The chemical interaction between MWSB nanocomposites and polymer molecules was confirmed by Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. Besides, high-resolution transmission electron microscopy (HR-TEM), field emission scanning electron microscopy (FESEM), thermogravimetric analysis (TGA) and UV–visible spectrophotometry were also employed to characterise the synthesised nanocomposites. The morphological study indicated that the polymers were deposited on the external surfaces of MWSB and the nanocomposites were seen to preserve their tubular structures even after the coating process was applied. The TGA results revealed that the incorporation of biopolymers practically improved the overall thermal stability of the coated MWSB nanocomposites. Evaluation of the in vitro effect on drug release rate by the nanocomposites was found to follow a biphasic release manner, showing a fast release at an initial stage and then a sustained-release over 2500 min. Besides, the drug release mechanisms of the nanocomposites demonstrated that the amount of SB released in the simulated environment was governed by pseudo-second order in which, the rate-limiting step mainly depends on diffusion of drug through chemisorption reaction. Finally, MTT assay showed that the coated MWSB nanocomposites on 3T3 cells were very much biocompatible at a concentration up to 100 g/mL, which is an evidence of MWSB reduced cytotoxicity.
Spouses’ faces are similar but do not become more similar with time
Authors: Tea-makorn Pin Pin , Kosinski Michal
Published: October 2020

The widely disseminated convergence in physical appearance hypothesis posits that long-term partners’ facial appearance converges with time due to their shared environment, emotional mimicry, and synchronized activities. Although plausible, this hypothesis is incompatible with empirical findings pertaining to a wide range of other traits—such as personality, intelligence, attitudes, values, and well-being—in which partners show initial similarity but do not converge over time. We solve this conundrum by reexamining this hypothesis using the facial images of 517 couples taken at the beginning of their marriages and 20 to 69 years later. Using two independent methods of estimating their facial similarity (human judgment and a facial recognition algorithm), we show that while spouses’ faces tend to be similar at the beginning of marriage, they do not converge over time, bringing facial appearance in line with other personal characteristics.
Light environments affect herbivory patterns but not reproductive performance of a multivoltine specialist moth, Pareuchaetes pseudoinsulata
Authors: Uyi Osariyekemwen O.
Published: October 2020

Unravelling the responses of insect herbivores to light-environment-mediated variation in the traits of their host plants is central to our understanding of the nutritional ecology of, and factors driving the population dynamics in, these species. This study examined the effect of light environment (shaded vs full-sun habitat) on leaf toughness and leaf nutritional quality in Chromolaena odorata (an invasive species in West Africa) and related these attributes to the abundance, herbivory patterns and reproductive performance of a multivoltine specialist moth, Pareuchaetes pseudoinsulata (a biological control agent). In this system, plants growing in shaded areas in the field experienced more herbivory and had higher herbivore abundance than those growing in full-sun. In the laboratory, P. pseudoinsulata larvae consumed significantly greater amounts of shaded foliage relative to full-sun foliage. However, reproductive performance metrics such as mating success, pre-oviposition period, number of eggs laid, duration of egg laying, egg hatchability, and adult longevity in P. pseudoinsulata did not differ according to foliage types. Reduced leaf toughness, increased water and nitrogen contents in shaded leaves coincided with increased leaf consumption by the larvae of P. pseudoinsulata. In summary, this study showed for the first time that light environments affect herbivory patterns but not reproductive performance of P. pseudoinsulata and hypothesized that high foliar nitrogen and water contents in shaded leaves resulted in feedback and necessity consumption patterns.
Generative machine learning for robust free-space communication
Authors: Lohani Sanjaya , Knutson Erin M. , Glasser Ryan T.
Published: October 2020

Free-space optical communications systems suffer from turbulent propagation of light through the atmosphere, attenuation, and receiver detector noise. These effects degrade the quality of the received state, increase cross-talk, and decrease symbol classification accuracy. We develop a state-of-the-art generative neural network (GNN) and convolutional neural network (CNN) system in combination, and demonstrate its efficacy in simulated and experimental communications settings. Experimentally, the GNN system corrects for distortion and reduces detector noise, resulting in nearly identical-to-desired mode profiles at the receiver, requiring no feedback or adaptive optics. Classification accuracy is significantly improved when these generated modes are demodulated using a CNN that is pre-trained with undistorted modes. Using the GNN and CNN system exclusively pre-trained with simulated optical profiles, we show a reduction in cross-talk between experimentally-detected noisy/distorted modes at the receiver. This scalable scheme may provide a concrete and effective demodulation technique for establishing long-range classical and quantum communication links.
Determination of ultra-low concentrations of gaseous 14C-bearing hydrocarbons produced during corrosion of irradiated steel using accelerator mass spectrometry
Authors: Guillemot T. , Salazar G. , Cvetković B. Z. , Kunz D. , Szidat S. , Wieland E.
Published: October 2020

Compound specific radiocarbon analysis, based on gas chromatography and accelerator mass spectrometry, was developed to quantify gaseous 14C species released at pico- to femtomolar concentrations during alkaline anoxic corrosion of irradiated steel.
Development of an accurate method for dispersion and quantification of carbon nanotubes in biological media
Authors: González-Legarreta Lorena , Renero-Lecuna Carlos , Valiente Rafael , Fanarraga Mónica L.
Published: October 2020

A complete method to disperse, functionalize and accurately quantify carbon nanotubes for biological applications in nanomedicine is developed and described.
Three-dimensional printed 5-fluorouracil eluting polyurethane stents for the treatment of oesophageal cancers
Authors: Fouladian Paris , Kohlhagen Jarrod , Arafat Mohammad , Afinjuomo Franklin , Workman Nathan , Abuhelwa Ahmad Y. , Song Yunmei , Garg Sanjay , Blencowe Anton
Published: October 2020

3D printing is introduced as rapid and facile approach to prepare personalized drug-eluting stents for the treatment of oesophageal cancers.
A one-dimensional switchable dielectric material with Pd uptake function: [(CH2)3NH2S]2BiCl5
Authors: Liu Yu-Ting , He Lei , Shi Ping-Ping , Ye Qiong , Fu Da-Wei
Published: October 2020

[(CH2)3NH2S]2BiCl5 has dielectric switching and Pd uptake functions, and its adsorption can be monitored by changes in dielectric properties.
Accelerating hydrogen evolution in Ru-doped FeCoP nanoarrays with lattice distortion toward highly efficient overall water splitting
Authors: Liu Huan , Li Xiaoning , Ge Liangbing , Peng Cailing , Zhu Liuyang , Zou Wei , Chen Jifang , Wu Qingmei , Zhang Yuanxi , Huang Haoliang , Wang Jianlin , Cheng Zhenxiang , Fu Zhengping , Lu Yalin
Published: October 2020

In situ synthesized Ru-doped FeCoP nanoarray electrocatalysts with high activity and stability for overall water splitting.
Regulating the coordination structure of metal single atoms for efficient electrocatalytic CO2 reduction
Authors: Wang Yuchao , Liu Yi , Liu Wei , Wu Jiao , Li Qian , Feng Qingguo , Chen Zhiyan , Xiong Xiang , Wang Dingsheng , Lei Yongpeng
Published: October 2020

An in-depth summary about the regulation of the coordination structure in single atom catalysts for the CO2RR is summarized.
EGCG targeting Notch to attenuate renal fibrosisviainhibition of TGFβ/Smad3 signaling pathway activation in streptozotocin-induced diabetic mice
Authors: Zhu Qiang-Qiang , Yang Xiao-Ying , Zhang Xiao-Juan , Yu Cai-Jun , Pang Qian-Qian , Huang Ye-wei , Wang Xuan-jun , Sheng Jun
Published: October 2020

EGCG may improve renal fibrosis by targeting Notchviainhibition of the TGFβ/Smad3 pathway in diabetic mice.
Surface-functionalized mesoporous gallosilicate catalysts for the efficient and sustainable upgrading of glycerol to solketal
Authors: Vivian Alvise , Soumoy Loraine , Fusaro Luca , Fiorilli Sonia , Debecker Damien P. , Aprile Carmela
Published: October 2020

Hybrid gallosilicate catalysts prepared in a continuous one-pot procedure are proposed as active and reusable solids in the conversion of glycerol into solketal
Cleavage of ethers and demethylation of lignin in acidic concentrated lithium bromide (ACLB) solution
Authors: Li Zheng , Sutandar Eka , Goihl Thomas , Zhang Xiao , Pan Xuejun
Published: October 2020

Acidic concentrated lithium bromide (ACLB) solution can efficiently cleave regular ethers and demethylate lignin and lignin model compounds.
Highly depth-resolved characterization of fusion-related tungsten material based on picosecond laser-induced breakdown spectroscopy
Authors: Zhao Dongye , Wu Ding , Oelmann Jannis , Brezinsek Sebastijan , Xiao Qingmei , Yi Rongxing , Cai Laizhong , Ding Hongbin
Published: October 2020

The objective of the present study has been to evaluate the potential applications of picosecond laser-induced breakdown spectroscopy (ps-LIBS) in nuclear fusion devices.
Nanoconjugates of graphene oxide derivatives and meso-tetraphenylporphyrin: a new avenue for anticancer photodynamic therapies – Cell-on-a-Chip analysis
Authors: Zuchowska A. , Kasprzak A. , Dabrowski B. , Kaminska K. , Poplawska M. , Brzozka Z.
Published: October 2020

Cell-on-a-Chip analysis of nanoconjugates of graphene oxide derivatives and mesotetraphenylporphyrin as a new selective and effective avenue for anticancer photodynamic therapies.
Chemistry of Ru(edta) complexes relevant to oxidoreductase mimicking: a personal perspective
Authors: Chatterjee Debabrata
Published: October 2020

This article chronicles the enzyme mimicking chemistry of Ru(edta) complexes (edta4− = ethylenediaminetetraacetate) in regard to small molecule activation.
Endocytosis-driven gold nanoparticle fractal rearrangement in cells and its influence on photothermal conversion
Authors: Mulens-Arias Vladimir , Balfourier Alice , Nicolás-Boluda Alba , Carn Florent , Gazeau Florence
Published: October 2020

Cellular endocytosis and intracellular trafficking of nanoparticles induce dynamic rearrangements that profoundly modify the physical properties of nanoparticle and govern their biological outcomes when activated by external fields.
Synthesis of luminescent core/shell α-Zn3P2/ZnS quantum dots
Authors: Paredes Ingrid J. , Beck Clara , Lee Scott , Chen Shuzhen , Khwaja Mersal , Scimeca Michael R. , Li Shuang , Hwang Sooyeon , Lian Zhen , McPeak Kevin M. , Shi Su-Fei , Sahu Ayaskanta
Published: October 2020

Optoelectronic applications of Zn3P2 quantum dots have long been hindered by surface oxidation and defect states leading to low PL quantum yield. The authors present shelling of Zn3P2 with ZnS to prevent oxidation and obtain luminescent particles.
Base-mediated 1,3-dipolar cycloaddition of pyridinium bromides with bromoallyl sulfones: a facile access to indolizine scaffolds
Authors: Jadala Chetna , Ganga Reddy Velma , Hari Krishna Namballa , Shankaraiah Nagula , Kamal Ahmed
Published: October 2020

A mild, transition-metal-free strategy has been described for the construction of substituted indolizines by 1,3-dipolar cycloaddition of pyridinium bromides with bromoallyl sulfones in the presence of a base.
NaHSO4/SiO2 catalyzed generation of o-quinone/ o-thioquinone methides: synthesis of arylxanthenes/ arylthioxanthenes via oxa-6π-electrocyclization
Authors: Karthick Muthupandi , Konikkara Abi Edwin , Someshwar Nagamalla , Anthony Savarimuthu Philip , Ramanathan Chinnasamy Ramaraj
Published: October 2020

Arylxanthenes/arylthioxanthenes, with a hydride donor and turn-on fluorescence properties, have been synthesized efficiently from 2-(hydroxydiarylmethyl)phenols/thiophenols.
Cationic polymerization of vinyl monomers using halogen bonding organocatalysts with varied activity
Authors: Takagi Koji , Murakata Hiroto , Yamauchi Koji , Hashimoto Kohei
Published: October 2020

Cationic polymerization of vinyl monomers was investigated using non-ionic and ionic halogen bonding organocatalysts.
The performance of emerging materials derived from waste organism blood and saponified modified orange peel for immobilization of available Cd in soil
Authors: HuangFu Zhuoxi , Ran Zongxin , Mo Yinpeng , Xu Zichen , Wei Wei , Yu Jiang , Lai Bo , Wang Xingrun
Published: October 2020

In our study, waste organism blood (WOB) and chemically modified orange peel (SOP) were applied to investigate their sorption potential for the immobilization of available Cd in soils.
1,2-Addition and cycloaddition reactions of niobium bis(imido) and oxo imido complexes
Authors: Fostvedt Jade I. , Grant Lauren N. , Kriegel Benjamin M. , Obenhuber Andreas H. , Lohrey Trevor D. , Bergman Robert G. , Arnold John
Published: October 2020

Another slice of pi: the addition of a second π-donor ligand engenders 1,2-addition and [2 + 2] cycloaddition reactivity across Nb-imido and Nb-oxo bonds.
CuO–C modified glass fiber films with a mixed ion and electron-conducting scaffold for highly stable lithium metal anodes
Authors: Shen Xiaojie , Zhao Guangyu , Fan Lishuang , Guo Zhikun , Zhao Chenyang , Chen Aosai , Yang Guiye , Cheng Zhongjun , Zhang Naiqing
Published: October 2020

3D CuO–C modified glass fiber films with a mixed ion and electron-conducting network to realize the homogenized lithium ion flux by supplying widespread inner lithium ion transport channels in the skeleton.
A facile strategy to construct silk fibroin based GTR membranes with appropriate mechanical performance and enhanced osteogenic capacity
Authors: Zheng Xiaoran , Ke Xiang , Yu Peng , Wang Dingqian , Pan Siyu , Yang Jiaojiao , Ding Chunmei , Xiao Shimeng , Luo Jun , Li Jianshu
Published: October 2020

A facile method to modify electrospun silk fibroin nanofibrous membranes for enhanced mechanical properties and osteogenic function via polyphenol chemistry.
microRNA regulation of pluripotent state transition
Authors: Wang Shao-Hua , Zhang Chao , Wang Yangming
Published: October 2020

microRNAs (miRNAs) play essential roles in mouse embryonic stem cells (ESCs) and early embryo development. The exact mechanism by which miRNAs regulate cell fate transition during embryo development is still not clear. Recent studies have identified and captured various pluripotent stem cells (PSCs) that share similar characteristics with cells from different stages of pre- and post-implantation embryos. These PSCs provide valuable models to understand miRNA functions in early mammalian development. In this short review, we will summarize recent work towards understanding the function and mechanism of miRNAs in regulating the transition or conversion between different pluripotent states. In addition, we will highlight unresolved questions and key future directions related to miRNAs in pluripotent state transition. Studies in these areas will further our understanding of miRNA functions in early embryo development, and may lead to practical means to control human PSCs for clinical applications in regenerative medicine.
Kalkayotl: A cluster distance inference code
Authors: Olivares J. , Sarro L. M. , Bouy H. , Miret-Roig N. , Casamiquela L. , Galli P. A. B. , Berihuete A. , Tarricq Y.
Published: October 2020

Context. The high-precision parallax data of the Gaia mission allows for significant improvements in the distance determination to stellar clusters and their stars. In order to obtain accurate and precise distance determinations, systematics such as parallax spatial correlations need to be accounted for, especially with regard to stars in small sky regions.

Aims. Our aim is to provide the astrophysical community with a free and open code designed to simultaneously infer cluster parameters (i.e., distance and size) and distances to the cluster stars using Gaia parallax measurements. The code includes cluster-oriented prior families and it is specifically designed to deal with the Gaia parallax spatial correlations.

Methods. A Bayesian hierarchical model is created to allow for the inference of both the cluster parameters and distances to its stars.

Results. Using synthetic data that mimics Gaia parallax uncertainties and spatial correlations, we observe that our cluster-oriented prior families result in distance estimates with smaller errors than those obtained with an exponentially decreasing space density prior. In addition, the treatment of the parallax spatial correlations minimizes errors in the estimated cluster size and stellar distances, and avoids the underestimation of uncertainties. Although neglecting the parallax spatial correlations has no impact on the accuracy of cluster distance determinations, it underestimates the uncertainties and may result in measurements that are incompatible with the true value (i.e., falling beyond the 2σ uncertainties).

Conclusions. The combination of prior knowledge with the treatment of Gaia parallax spatial correlations produces accurate (error < 10%) and trustworthy estimates (i.e., true values contained within the 2σ uncertainties) of cluster distances for clusters up to ∼5 kpc, along with cluster sizes for clusters up to ∼1 kpc.
Formation of sdB-stars via common envelope ejection by substellar companions
Authors: Kramer M. , Schneider F. R. N. , Ohlmann S. T. , Geier S. , Schaffenroth V. , Pakmor R. , Röpke F. K.
Published: October 2020

Common envelope (CE) phases in binary systems where the primary star reaches the tip of the red giant branch are discussed as a formation scenario for hot subluminous B-type (sdB) stars. For some of these objects, observations point to very low-mass companions. In hydrodynamical CE simulations with the moving-mesh code AREPO, we test whether low-mass objects can successfully unbind the envelope. The success of envelope removal in our simulations critically depends on whether or not the ionization energy released by recombination processes in the expanding material is taken into account. If this energy is thermalized locally, envelope ejection eventually leading to the formation of an sdB star is possible with companion masses down to the brown dwarf range. For even lower companion masses approaching the regime of giant planets, however, envelope removal becomes increasingly difficult or impossible to achieve. Our results are consistent with current observational constraints on companion masses of sdB stars. Based on a semi-analytic model, we suggest a new criterion for the lowest companion mass that is capable of triggering a dynamical response of the primary star thus potentially facilitating the ejection of a CE. This gives an estimate consistent with the findings of our hydrodynamical simulations.
LENSINGGW: a PYTHON package for lensing of gravitational waves
Authors: Pagano G. , Hannuksela O. A. , Li T. G. F.
Published: October 2020

Advanced LIGO and Advanced Virgo might be able to observe the first lensed gravitational waves in the coming years. With the addition of the KAGRA and LIGO India detectors to the detector network and with the future construction of theEinsteinTelescope we might be able to observe hundreds of lensed events. Ground-based gravitational-wave detectors can resolve arrival-time differences on the order of the inverse of the observed frequencies. The LIGO and Virgo frequency band spans from a few Hz to a few kHz, therefore the typical time resolution of current interferometers is on the order of milliseconds. When microlenses are embedded in galaxies or galaxy clusters, lensing can become more prominent and result in observable time delays at LIGO and Virgo frequencies. Therefore, gravitational waves might offer an exciting alternative probe of microlensing. However, only a few lensing configurations have currently been worked out in the context of gravitational-wave lensing. In this paper, we presentLENSINGGW, a PYTHONpackage designed to handle both strong lensing and microlensing of compact binaries and the related gravitational-wave signals in the geometrical optics limit. This synergy paves the way for systematic parameter space investigations and for the detection of arbitrary lens configurations and compact sources. Here we focus on the LIGO and Virgo frequencies. We demonstrate the working mechanism ofLENSINGGW and its use in studying microlenses that are embedded in galaxies.
The CARMENES search for exoplanets around M dwarfs
Authors: Stock S. , Nagel E. , Kemmer J. , Passegger V. M. , Reffert S. , Quirrenbach A. , Caballero J. A. , Czesla S. , Béjar V. J. S. , Cardona C. , Díez-Alonso E. , Herrero E. , Lalitha S. , Schlecker M. , Tal-Or L. , Rodríguez E. , Rodríguez-López C. , Ribas I. , Reiners A. , Amado P. J. , Bauer F. F. , Bluhm P. , Cortés-Contreras M. , González-Cuesta L. , Dreizler S. , Hatzes A. P. , Henning Th. , Jeffers S. V. , Kaminski A. , Kürster M. , Lafarga M. , López-González M. J. , Montes D. , Morales J. C. , Pedraz S. , Schöfer P. , Schweitzer A. , Trifonov T. , Zapatero Osorio M. R. , Zechmeister M.
Published: October 2020

We announce the discovery of two planets orbiting the M dwarfs GJ 251 (0.360 ± 0.015M⊙) and HD 238090 (0.578 ± 0.021M⊙) based on CARMENES radial velocity (RV) data. In addition, we independently confirm with CARMENES data the existence of Lalande 21185 b, a planet that has recently been discovered with the SOPHIE spectrograph. All three planets belong to the class of warm or temperate super-Earths and share similar properties. The orbital periods are 14.24 d, 13.67 d, and 12.95 d and the minimum masses are 4.0 ± 0.4 M⊕, 6.9 ± 0.9 M⊕, and 2.7 ± 0.3 M⊕ for GJ 251 b, HD 238090 b, and Lalande 21185 b, respectively. Based on the orbital and stellar properties, we estimate equilibrium temperatures of 351.0 ± 1.4 K for GJ 251 b, 469.6 ± 2.6 K for HD 238090 b, and 370.1 ± 6.8 K for Lalande 21185 b. For the latter we resolve the daily aliases that were present in the SOPHIE data and that hindered an unambiguous determination of the orbital period. We find no significant signals in any of our spectral activity indicators at the planetary periods. The RV observations were accompanied by contemporaneous photometric observations. We derive stellar rotation periods of 122.1 ± 2.2 d and 96.7 ± 3.7 d for GJ 251 and HD 238090, respectively. The RV data of all three stars exhibit significant signals at the rotational period or its first harmonic. For GJ 251 and Lalande 21185, we also find long-period signals around 600 d, and 2900 d, respectively, which we tentatively attribute to long-term magnetic cycles. We apply a Bayesian approach to carefully model the Keplerian signals simultaneously with the stellar activity using Gaussian process regression models and extensively search for additional significant planetary signals hidden behind the stellar activity. Current planet formation theories suggest that the three systems represent a common architecture, consistent with formation following the core accretion paradigm.
The nature of the radius valley
Authors: Venturini Julia , Guilera Octavio M. , Haldemann Jonas , Ronco María P. , Mordasini Christoph
Published: October 2020

The existence of a radius valley in the Kepler size distribution stands as one of the most important observational constraints to understand the origin and composition of exoplanets with radii between those of Earth and Neptune. In this work we provide insights into the existence of the radius valley, first from a pure formation point of view and then from a combined formation-evolution model. We run global planet formation simulations including the evolution of dust by coagulation, drift, and fragmentation, and the evolution of the gaseous disc by viscous accretion and photoevaporation. A planet grows from a moon-mass embryo by either silicate or icy pebble accretion, depending on its position with respect to the water ice line. We include gas accretion, type I–II migration, and photoevaporation driven mass-loss after formation. We perform an extensive parameter study evaluating a wide range of disc properties and initial locations of the embryo. We find that due to the change in dust properties at the water ice line, rocky cores form typically with ∼3 M⊕ and have a maximum mass of ∼5 M⊕, while icy cores peak at ∼10 M⊕, with masses lower than 5 M⊕ being scarce. When neglecting the gaseous envelope, the formed rocky and icy cores account naturally for the two peaks of the Kepler size distribution. The presence of massive envelopes yields planets more massive than ∼10 M⊕ with radii above 4 R⊕. While the first peak of the Kepler size distribution is undoubtedly populated by bare rocky cores, as shown extensively in the past, the second peak can host half-rock–half-water planets with thin or non-existent H-He atmospheres, as suggested by a few previous studies. Some additional mechanisms inhibiting gas accretion or promoting envelope mass-loss should operate at short orbital periods to explain the presence of ∼10–40 M⊕ planets falling in the second peak of the size distribution.
Titanium Research Developments in the United Kingdom
Authors: Jackson Martin
Published: October 2020

The paper presents highlights of the titanium alloy research developments since Ti-2015 (San Diego). The review underlines the strong and collaborative fundamental research conducted at UK universities through strategic government sponsored programmes. The role of advanced characterisation and modelling techniques in order to better understand the effects of deformation, fatigue loading and environment on titanium alloys continues to be world leading. Researchers in the UK are also continuing to develop a range of new alloys, methods of extraction and emerging near net shape processes via casting, powder and wire-fed routes.
Study of Arc-wire and Laser-wire processes for the realization of Ti-6Al-4V alloy parts
Authors: Ayed A. , Bras G. , Bernard H. , Michaud P. , Balcaen Y. , Alexis J.
Published: October 2020

Arc-wire or laser-wire additive manufacturing seems promising because it allows large parts to be produced with significant deposition rates (ten times higher than powder bed additive manufacturing), for a lower investment cost. These additive manufacturing techniques are also very interesting for the construction or the repair of parts. A versatile 3D printing device using a Wire Arc Additive Manufacturing (WAAM) station or laser device Wire Laser Additive Manufacturing (WLAM) for melting a filler wire is developed to repair and build large titanium parts. The final objectives of the study are to optimize the process parameters to control the dimensional stability, the metallurgical and mechanical properties of the produced parts. In this paper, an experimental study is carried out to determine the first order process parameter ranges (synergic law, laser power, wire feed speed, travel speed) appropriate for these two techniques, for repair or construction parts on Ti-6 Al-4V.
Microscopic strain localisation in WAAM Ti-6Al-4V during uniaxial tensile loading
Authors: Lunt David , Ho Alistair , Davis Alec , Martina Filomeno , Hönnige Jan , Quinta da Fonseca João , Prangnell Phillip
Published: October 2020

Wire Arc-Based Additive manufacturing is a high deposition rate process suitable for building large-scale aerospace components. However, the larger heat source can cause greater microstructural heterogeneity and, in particular, a coarse columnar ß grain structure. The effect of the subsequent related transformation microstructure heterogeneity on the mechanical behaviour is investigated, in both standard WAAM materials and samples subjected to inter-pass rolling, which leads to substantial ß grain refinement and texture randomisation. Full-field strain maps were produced by digital image correlation, using tensile samples loaded in different orientations. When loaded normal to the columnar grain structure, it is shown that the coarse ß grains lead to a highly heterogeneous deformation distribution, which is linked the presence of dominant hard and soft α variants in texture colonies within each parent ß grain. ß grain refinement through the application of inter-pass rolling was found to be very effective at homogenising the strain localisation for all test orientations.
Direct Laser Additive Manufacturing of TiAl Intermetallic Compound by Powder Directed Energy Deposition (DED)
Authors: Choron Damien , Naveos Serge , Thomas Marc , Petit Johan , Boisselier Didier
Published: October 2020

Directed Energy Deposition of the commercial intermetallic Ti-48Al-2Cr-2Nb alloy was investigated. The CLAD® process is dependent on multiple parameters, which were successfully optimised through several experiments, including series of beads, small blocks, and massive blocks, under argon atmosphere. The use of adapted temperature management leads to massive blocks manufacturing that bear no apparent macroscopic defects, such as cracks, which are generally observed in this brittle material due to strong temperature cycling during the manufacturing. The microstructure and geometrical parameters were characterised by scanning electron microscopy (SEM). This process generates an ultra-fine and anisotropic microstructure, which is restored to a homogeneous duplex microstructure by a subsequent heat-treatment. Mechanical characterisation is in progress and will be used to validate the soundness of the materials produced in these conditions.
Texture of electron beam melted Ti-6Al-4V measured with neutron diffraction
Authors: Neikter M. , Woracek R. , Durniak C. , Persson M. , Antti M.-L. , Åkerfeldt P. , Pederson R. , Zhang J. , Vogel S.C. , Strobl M.
Published: October 2020

Texture in materials is important as it contributes to anisotropy in the bulk mechanical properties. Ti-6Al-4V built with the additive manufacturing process (AM) electron beam melting (EBM) has been found to have anisotropic mechanical properties. Therefore, this work has been performed to investigate the texture variations of EBM built Ti-6Al-4V with neutron time of flight (TOF). For the work, samples were produced with different build geometries off-set by 90 degrees. A cast sample was additionally analyzed to investigate the bulk texture of conventionally manufactured material. Microstructural characterization was performed and the cast material was found to have a coarse colony α microstructure, whereas the EBM built material had a finer basket weave microstructure. Overall, the texture of the EBM built material was found to be weak having an multiple of random distribution (MRD) index of ~1 for the α phase, whilst the cast material possessed more than twice the amount of preferred orientation i.e. MRD 2.51 for the α phase.
A Novel Technique to Assess the Effect of Machining and Subsurface Microstructure on the Fatigue Performance of Ti-6Al-2Sn-4Zr-6Mo
Authors: Suárez-Fernández Daniel , Wynne Bradley P. , Crawforth Pete , Fox Katharine , Jackson Martin
Published: October 2020

Aerospace titanium components are manufactured under the strictest standards in order to ensure the highest quality. To develop highly efficient machining processes, extensive research and investment is necessary. For the specific case of rotating titanium critical components, large quantities of forged workpieces are machined to determine the effects of the different machining parameters on tool wear characteristics and component structural integrity and performance. However, testing the different permutations of metal removal parameters and tool combinations is expensive and time consuming at the development stage. The novel approach developed and presented here, enables the machining of smaller titanium parts that can be compared 1-to-1 to parts extracted from industrial machined disc components. This approach not only reduces cost, but ultimately accelerates the research and development process due to more rapid feedback between different iterations of the machining parameters.

The proposed technique specifically replicates the face turning operation performed in rotational critical titanium components, such as compressor discs, using small coupons machined in a standard CNC machining centre. The machined coupons can be fatigue tested through a 4-point bending and microstructural analysis can be performed on the tested coupons to directly study the effects of the machining process on the surface and underlying microstructure.
Superior Oxidation Resistance Titanium Alloy ARCONIC-THORTM for Aerospace Applications
Authors: Tamirisakandala Sesh , Crist Ernie , Sun Fusheng , Dahar Matthew
Published: October 2020

Next generation fuel-efficient jet engines are running hotter presenting a structural challenge for the exhaust systems and structures adjacent to the engines. A conventional and affordable titanium alloy with superior oxidation resistance provides significant weight reductions and associated cost savings by eliminating the need for high density material systems such as nickel-base superalloys for service temperatures in between current titanium and nickel, enabling major technology advancement in high temperature aerospace applications. This paper presents an overview of Arconic’s engineered material ARCONIC-THORTM to address the needs of future aerospace systems.
Influence of soft interlayers on fretting fatigue and fretting wear resistance of Ti-6Al-4V alloy
Authors: Ma Amin , Liu Daoxin , Zhang Xiaohua
Published: October 2020

Ti-6Al-4V alloy is the main structure material of aerospace components due to its excellent corrosion resistance, high specific strength and other good characteristics. However, this alloy has low hardness, poor wear resistance and higher friction coefficient, so it is very sensitive to fretting wear (FW) and fretting fatigue (FF) damages. In this work, we studied three kinds of soft inter-layers (copper foil, nickel foil and polytetrafluoroethylene (PTFE) lamella) between the Ti-6Al-4V fatigue samples and the Ti-6Al-4V counterparts respectively to enhance the FF and FW resistance of this alloy. The results show that the method is an economical and effective way to increase the FF and FW resistance of Ti-6Al-4V alloy. The order of enhancement in the FF resistance of the titanium alloy was copper foil > PTFE lamella > nickel foil. Additionally, the friction coefficients of PTFE lamella, copper foil, nickel foil and Ti-6Al-4V alloy were about 0.10, 0.60, 0.65 and 1.1, respectively. The lowest friction coefficient of PTFE, compared with copper foil, nickel foil and substrate, was of great benefit to improving the FF property of Ti-6Al-4V alloy. Nevertheless, the FF life of Ti-6Al-4V alloy with the copper interlayer was higher than PTFE, which was about 5 times higher than substrate.
TITANIUM SHEET HOT FORMING IN THE AEROSPACE INDUSTRY
Authors: SANA Guillaume
Published: October 2020

Technologies dedicated to hot forming of titanium sheet are key processes for the manufacturing of structural and engine parts in the aerospace industry. The evolution of these processes in the past years is strategical taking into account the on-going increase of production rate of commercial aircrafts as single aisle and long-range civil aircrafts.

Starting from the use of single superplastic forming press, the state-of-the art has evolved to the use of automated forming cells from one side and to the development of the Hot Forming process on the other side. These evolutions are pushed by the aerospace market and its needs of a strong and efficient supply chain.

In order to assure production rate, cost saving and part quality to our customer, Aries Alliance offers tailor made solutions adapted to each customer need. From the delivery of fully-automated smart press cell to serial part production Aries Alliance is able to provide smart answer to the challenges brought by end-users. One of the roles of this niche industry is also to promote titanium applications challenged by the market facing strong competition from lightweight alloys like Al‑Li or composite materials especially for aerostructure applications.
Study of superelastic performance on novel (Ti-Zr)-based alloy: Influence of thermal treatment time
Authors: Gao J.J. , Castany P. , Laillé D. , Thibon I. , Gloriant T.
Published: October 2020

In this study, the superelastic performance of a novel metastable β Ti-20Zr-3Mo-3Sn alloy (at.%) displaying stress-induced α” martensitic (SIM) transformation is investigated by resistivity, cyclic tensile tests and electron back-scattered diffraction (EBSD) for three different solution treatment durations: 5 min, 30 min and 60 min at 700°C. EBSD observations reveal that the Ti-20Zr-3Mo-3Sn alloy presents different recrystallization texture in the three conditions while keeping the optimal <110>β direction along the rolling direction. All the samples displayed high recovery strain which is more than 3.0%. However, the shortest heat treatment time allows to stabilize the superelastic behavior at this maximum value for a wide range of applied strain.