bluuebunny/crossref_metadata_2025 huggingface dataset:
Strayfield calculation for micromagnetic simulations using true periodic boundary conditions
Authors: Bruckner Florian , Ducevic Amil , Heistracher Paul , Abert Claas , Suess Dieter
Published: April 2021

We present methods for calculating the strayfield in finite element and finite difference micromagnetic simulations using true periodic boundary conditions. In contrast to pseudo periodic boundary conditions, which are widely used in micromagnetic codes, the presented methods eliminate the shape anisotropy originating from the outer boundary. This is a crucial feature when studying the influence of the microstructure on the performance of composite materials, which is demonstrated by hysteresis calculations of soft magnetic structures that are operated in a closed magnetic loop configuration. The applied differential formulation is perfectly suited for the application of true periodic boundary conditions. The finite difference equations can be solved by a highly efficient Fast Fourier Transform method.
Antenatal diagnosis of placenta accreta spectrum after in vitro fertilization-embryo transfer: a systematic review and meta-analysis
Authors: Matsuzaki Shinya , Nagase Yoshikazu , Takiuchi Tsuyoshi , Kakigano Aiko , Mimura Kazuya , Lee Misooja , Matsuzaki Satoko , Ueda Yutaka , Tomimatsu Takuji , Endo Masayuki , Kimura Tadashi
Published: April 2021

Increasing evidence suggests a relationship between in vitro fertilization-embryo transfer (IVF-ET) and placenta accreta spectrum (PAS). Some studies have reported a lower rate of antenatal diagnosis of PAS after IVF-ET compared to PAS with spontaneous conception. This study aimed to review the diagnostic accuracy of PAS after IVF-ET and to explore the relationship between IVF-ET pregnancy and PAS. According to the PRISMA guidelines, a comprehensive systematic review of the literature was conducted through August 31, 2020 to determine the effects of IVF-ET on PAS. In addition, a meta-analysis was conducted to explore the relationship between IVF-ET pregnancy and PAS. Twelve original studies (2011–2020) met the inclusion criteria. Among these, 190,139 IVF-ET pregnancies and 248,534 spontaneous conceptions met the inclusion criteria. In the comparator analysis between PAS after IVF-ET and PAS with spontaneous conception (n = 2), the antenatal diagnosis of PAS after IVF-ET was significantly lower than that of PAS with spontaneous conception (22.2% versus 94.7%, P < 0.01; < 12.9% versus 46.9%, P < 0.01). The risk of PAS was significantly higher in women who conceived with IVF-ET than in those with spontaneous conception (odds ratio [OR]: 5.03, 95% confidence interval [CI]: 3.34–7.56, P < 0.01). In the sensitivity analysis accounting for the type of IVF-ET, frozen ET was associated with an increased risk of PAS (OR: 4.60, 95%CI: 3.42–6.18, P < 0.01) compared to fresh ET. Notably, frozen ET with hormone replacement cycle was significantly associated with the prevalence of PAS compared to frozen ET with normal ovulatory cycle (OR: 5.76, 95%CI 3.12–10.64, P < 0.01). IVF-ET is associated with PAS, and PAS after IVF-ET was associated with a lower rate of antenatal diagnosis. Therefore, clinicians can pay more attention to the presence of PAS during antenatal evaluation in women with IVF-ET, especially in frozen ET with hormone replacement cycle.
Body weight variability and the risk of cardiovascular outcomes in patients with nonalcoholic fatty liver disease
Authors: Kim Mi Na , Han Kyungdo , Yoo Juhwan , Ha Yeonjung , Chon Young Eun , Lee Ju Ho , Simon Tracey G. , Chan Andrew T. , Hwang Seong Gyu
Published: April 2021

We investigated the association between body weight variability and the risks of cardiovascular disease and mortality in patients with nonalcoholic fatty liver disease (NAFLD) using large-scale, nationwide cohort data. We included 726,736 individuals with NAFLD who underwent a health examination between 2009 and 2010. NAFLD was defined as a fatty liver index ≥ 60, after excluding significant alcohol intake, viral hepatitis, and liver cirrhosis. Body weight variability was assessed using four indices, including variability independent of the mean (VIM). During a median 8.1-year follow-up, we documented 11,358, 14,714, and 22,164 cases of myocardial infarction (MI), stroke, and all-cause mortality, respectively. Body weight variability was associated with an increased risk of MI, stroke, and mortality after adjusting for confounding variables. The hazard ratios (HRs) (95% confidence intervals) for the highest quartile, compared with the lowest quartile, of VIM for body weight were 1.15 (1.10–1.20), 1.22 (1.18–1.26), and 1.56 (1.53–1.62) for MI, stroke, and all-cause mortality, respectively. Body weight variability was associated with increased risks of MI, stroke, and all-cause mortality in NAFLD patients. Appropriate interventions to maintain a stable weight could positively affect health outcomes in NAFLD patients.
Log-linear relationship between endogenous insulin secretion and glycemic variability in patients with type 2 diabetes on continuous glucose monitoring
Authors: Miya Aika , Nakamura Akinobu , Handa Takahisa , Nomoto Hiroshi , Kameda Hiraku , Cho Kyu Yong , Nagai So , Ito Yoichi M. , Miyoshi Hideaki , Atsumi Tatsuya
Published: April 2021

The contribution of endogenous insulin secretion to glycemic variability (GV) may differ between patients with impaired insulin secretion and those with preserved secretion. Our objective was to determine the linearity of the relationship between fasting C-peptide (CPR) as a marker of endogenous insulin secretion and GV in type 2 diabetes (T2DM), regardless of the type of antidiabetic treatment. We conducted a prospective observational study using continuous glucose monitoring obtained from 284 Japanese outpatients with T2DM with various HbA1c values and antidiabetic treatment. We constructed a prediction curve of base-line CPR versus coefficient of variation (CV) and identified the clinical factors associated with CV using multiple regression analysis. Fasting CPR showed a significant negative log-linear relationship with CV (P < 0.0001), and the latter being strikingly high in the low-CPR group. The multiple regression analysis showed that low CPR was an independent predictor of high CV (P < 0.0001). The significant correlations were sustained in both patients with/without insulin treatment. The contribution of endogenous insulin secretion to GV depends on the extent of insulin secretion impairment. Fasting CPR may represent a useful indicator of GV instability in T2DM.
Author Correction: Novel antimicrobial phosphate-free glass–ceramic scaffolds for bone tissue regeneration
Authors: Suárez M. , Fernández-García E. , Fernández A. , López-Píriz R. , Díaz R. , Torrecillas R.
Published: April 2021

An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Syntheses, design strategies, and photocatalytic charge dynamics of metal–organic frameworks (MOFs): a catalyzed photo-degradation approach towards organic dyes
Authors: Singh Ayushi , Singh Ashish Kumar , Liu Jianqiang , Kumar Abhinav
Published: April 2021

The presented review focuses on design strategies to develop tailor-made MOFs/CPs of main group, transition and inner-transition elements and their photocatalytic properties to decompose dyes in wastewater discharge and their photocatalytic mechanism.
Recent developments in sustainable corrosion inhibitors: design, performance and industrial scale applications
Authors: Verma Chandrabhan , Ebenso Eno E. , Quraishi M. A. , Hussain Chaudhery Mustansar
Published: April 2021

Recently, research studies in the fields of science and engineering are directed towards the synthesis, design, development, and consumption of environment-friendly chemical species to replace traditional toxic chemicals.
Optimization of active layer morphology by small-molecule donor design enables over 15% efficiency in small-molecule organic solar cells
Authors: An Cunbin , Qin Yunpeng , Zhang Tao , Lv Qianglong , Qin Jinzhao , Zhang Shaoqing , He Chang , Ade Harald , Hou Jianhui
Published: April 2021

Two conjugated small molecules with different conjugated side chains were synthesized to study their photovoltaic performances.
Heterostructures between a tin-based intermetallic compound and a layered semiconductor for gas sensing
Authors: Bao Jusheng , Zeng Shaoyu , Dai Jie , Wang Xiaoshan , Liu Qiang , Li Hai , Huang Xiao , Huang Wei
Published: April 2021

Pt3Sn nanoparticles are in situ deposited on SnS2 nanoplates to form heterostructures, which show promise as a selective NO2 sensing material at room temperature.
Superiority of a polymeric scavenger over its hexapodal monomer towards efficient ReO4− removal in water
Authors: Ghosh Rajib , Ghosh Tamal Kanti , Ghosh Pradyut
Published: April 2021

An imidazolium based hexapodal polymeric receptor, [PHIm-Br], showed selective and efficient removal (>99%) of ReO4− from 100% aqueous medium via solid–liquid extraction, which was 13% higher as compared to its monomeric analogue [HIm-Br].
Selective formation of form II paracetamol through the assistance of paracetamol co-crystals as templates in a solution
Authors: Yeh Kuan Lin , Lee Tu
Published: April 2021

The arrangement of paracetamol templated by the structure of 1 : 1 co-crystal of paracetamol–maleic acid in solution phase facilitating the nucleation of metastable form II paracetamol.
Ferroelectricity and switching polarization on the C–H⋯π bond in a pure organic molecular crystal – 1,3,5-trimethylnitrobenzene
Authors: Szklarz Przemysław , Kinzhybalo Vasyl , Bator Grażyna
Published: April 2021

The ferroelectric pure molecular crystal with spontaneous polarization related to flexibility of the C–H⋯π hydrogen bonds (molecular joints).
Water in biodegradable glucose–water–urea deep eutectic solvent: modifications of structure and dynamics in a crowded environment
Authors: Baksi Atanu , Rajbangshi Juriti , Biswas Ranjit
Published: April 2021

Molecular dynamics simulations have been performed on a highly viscous (η ∼ 255 cP) naturally abundant deep eutectic solvent (NADES) composed of glucose, urea and water in a weight ratio of 6 : 4 : 1 at 328 K.
Oxygen binding energy of doped metal: a shortcut to efficient Ni-based bimetallic catalysts for the hydrodeoxygenation reaction
Authors: Chen Lifang , Liu Wei , Feng Haisong , Ren Yingyu , Chen Chunyuan , Wang Si , Yin Pan , Yang Yusen , Zhang Xin , Wei Min
Published: April 2021

OBE is a convenient and effective descriptor to search for Ni-based bimetallic catalysts. Ni–M (M = Fe, Co, Mo, Ru) bimetallic catalysts were identified as highly active samples for furfural (FAL) HDO to 2-methylfuran (2-MF).
A new bis-pyrazolylpyridine ruthenium(iii) complex as a potential anticancer drug:in vitroandin vivoactivity in murine colon cancer
Authors: Lazić Dejan , Scheurer Andreas , Ćoćić Dušan , Milovanović Jelena , Arsenijević Aleksandar , Stojanović Bojana , Arsenijević Nebojša , Milovanović Marija , Rilak Simović Ana
Published: April 2021

Ru pincer-type complex1reduced primary tumor growth and the number and growth of lung and liver metastases, significantly prolonging the survival rate of treated mice.
Ethylenediamine complexes of the beryllium halides and pseudo-halides
Authors: Buchner Magnus R. , Müller Matthias
Published: April 2021

The suitability of ethylenediamine as a replacement solvent for liquid ammonia in beryllium chemistry was evaluated using BeF2, BeCl2, BeBr2, BeI2, [Be(NH3)4](N3)2, [Be(NH3)4](CN)2 and [Be(NH3)4](SCN)2 as benchmark compounds.
Pushing commercialization of perovskite solar cells by improving their intrinsic stability
Authors: Cheng Yuanhang , Ding Liming
Published: April 2021

This review provides a comprehensive understanding on degradation mechanisms related to intrinsic properties of perovskites and effective strategies for pushing commercialization of perovskite photovoltaic are summarized.
In situ formation of environmental endocrine disruptors from phytosterol degradation: a temporal model for agricultural soils
Authors: Gravert Thorsten Klaus Otto , Fauser Patrik , Olsen Preben , Hansen Martin
Published: April 2021

Phytosterol (i.e. β-sitosterol) from crop residue decay and soil fertilization can in situ form steroid hormones, surpassing added sex steroids excreted by livestock and humans.
Ginsenoside CK induces apoptosis of human cervical cancer HeLa cells by regulating autophagy and endoplasmic reticulum stress
Authors: Yin Qi , Chen Hua , Ma Run-Hui , Zhang Yuan-Yuan , Liu Miao-Miao , Thakur Kiran , Zhang Jian-Guo , Wei Zhao-Jun
Published: April 2021

Ginsenoside CK inhibits the cervical cancer HeLa cell Via blocking the cell cycle in the G0/G1 phase, and inducing apoptosis by the endoplasmic reticulum pathway.
Technologies of lithium recycling from waste lithium ion batteries: a review
Authors: Bae Hyuntae , Kim Youngsik
Published: April 2021

Although the interest in lithium recycling is increasing the current global lithium recycling rate is lower than 1%. For this reason, our paper aims to explain the needs, current state and future directions of lithium recycling technologies.
Computational determination of coordination structure impact on adsorption and acidity of pristine and sulfated MOF-808
Authors: Yang Bo , Wheeler Joshua I. , Sorensen Brett , Steagall Robert , Nielson Taylor , Yao Jianhua , Mendez-Arroyo Jose , Ess Daniel H.
Published: April 2021

Metal–organic frameworks (MOFs) are composed of metal nodes connected by organic linkers.
Cyclisation strategies for stabilising peptides with irregular conformations
Authors: Vu Quynh Ngoc , Young Reginald , Sudhakar Haritha Krishna , Gao Tianyi , Huang Tiancheng , Tan Yaw Sing , Lau Yu Heng
Published: April 2021

There are remarkably few examples of designing cyclic constraints for peptides which adopt an irregular conformation in their bioactive state. We discuss the design strategies, opportunities and challenges for this underexplored class of inhibitors.
Morphology-dependent fluorescence of europium-doped cerium oxide nanomaterials
Authors: D'Achille Anne E. , Wallace Robert M. , Coffer Jeffery L.
Published: April 2021

Eu3+-doped CeO2 nanorods, nanowires, nanocubes are utilized to assess the role of defect size/concentration and surface functionalization on Eu3+ photophysics.
Rational design and synthesis of chitosan–quinoa polysaccharide composite aerogel and its adsorption properties for Congo red and methylene blue
Authors: Tan Minghui , Zheng Shumin , Lv Hongning , Wang Bao , Zhao Qingsheng , Zhao Bing
Published: April 2021

This study was performed to investigate the potential application of a chitosan (CS) and quinoa polysaccharide (QS) composite aerogel for the adsorption of dyes from water.
Novel meta-benzothiazole and benzimidazole functionalised POCOP-Ni(ii) pincer complexes as efficient catalysts in the production of diarylketones
Authors: Castillo-García Antonio A. , González-Sebastián Lucero , Lomas-Romero Leticia , Hernandez-Ortega Simon , Toscano Ruben A. , Morales-Morales David
Published: April 2021

Novel meta-benzothiazole and benzimidazole functionalised POCOP-Ni(ii) pincer complexes were synthesized and used as effcient catalysts for the production of diarylketones.
Puckering transition of the proline residue along the pseudorotational path: revisited
Authors: Park Hae Sook , Kang Young Kee
Published: April 2021

Puckering transitions of the proline residue for Ac-Pro-X with trans and cis prolyl peptide bonds were explored along the pseudorotation phase angle using DFT methods in the gas phase and in water.
Nucleophilic vinylic substitution in bicyclic methyleneaziridines: SNVπ or SNVσ?
Authors: Palchykov Vitalii , Dale Peter C. , Robertson Jeremy
Published: April 2021

A stereoselective synthesis of the monodeuterated methyleneaziridine shown allowed the stereochemical course of formal SNV-mode ring-opening with copper-based organometallics to be assigned.
Fabrication of reversible pH-responsive aggregation-induced emission luminogens assisted by a block copolymer via a dynamic covalent bond
Authors: Wang Meiyao , Xu Lili , Lin Min , Li Zhibo , Sun Jing
Published: April 2021

Aggregated induced emission (AIE) molecules with stimuli-responsive properties have attracted increasing attention for many applications.
Thermally and photoinduced structural and chemical changes of a silver nanocube array on Au(111)
Authors: Iwahori Takeru , Mizuno Ayana , Ono Atsushi , Uehara Yoichi , Katano Satoshi
Published: April 2021

We have investigated the thermally and photoinduced structural and chemical changes of a polyvinylpyrrolidone (PVP)-covered silver nanocube (AgNC) array on Au(111).
A depth-suitable and water-stable trap for CO2 capture
Authors: Zhang Zhaofu , Liu Shuaishuai , Ma Jun , Wu Tianbin
Published: April 2021

Carboxylates can react with carbonic acid and form two united hydrogen bonds, which is depth-suitable for CO2 capture.
Generation and application of Cu-bound alkyl nitrenes for the catalyst-controlled synthesis of cyclic β-amino acids
Authors: Tak Raj K. , Amemiya Fuyuki , Noda Hidetoshi , Shibasaki Masakatsu
Published: April 2021

Copper-catalysed conditions have been developed for the chemoselective synthesis of cyclic β-amino acids.
Spread of in-plane anisotropy in CsPbBr3/ReS2heterostructures by proximity effect
Authors: Wang Renyan , Yasar Muhammad , Xu Xiang , Zhao Yida , Zhu Haiming , Gan Lin
Published: April 2021

We demonstrated experimentally the spread of in-plane anisotropy from anisotropic ReS2to isotropic CsPbBr3in the epitaxially grown CsPbBr3/ReS2heterostructures, as evidenced by the evolution of angle-resolved photoluminescence spectra.
Classification, structural biology, and applications of mucin domain-targeting proteases
Authors: Shon D. Judy , Kuo Angel , Ferracane Michael J. , Malaker Stacy A.
Published: April 2021

Epithelial surfaces throughout the body are coated by mucins, a class of proteins carrying domains characterized by a high density of O-glycosylated serine and threonine residues. The resulting mucosal layers form crucial host-microbe interfaces that prevent the translocation of microbes while also selecting for distinct bacteria via the presented glycan repertoire. The intricate interplay between mucus production and breakdown thus determines the composition of the microbiota maintained within these mucosal environments, which can have a large influence on the host during both homeostasis and disease. Most research to date on mucus breakdown has focused on glycosidases that trim glycan structures to release monosaccharides as a source of nutrients. More recent work has uncovered the existence of mucin-type O-glycosylation-dependent proteases that are secreted by pathogens, commensals, and mutualists to facilitate mucosal colonization and penetration. Additionally, immunoglobulin A (IgA) proteases promote bacterial colonization in the presence of neutralizing secretory IgA through selective cleavage of the heavily O-glycosylated hinge region. In this review, we summarize families of O-glycoproteases and IgA proteases, discuss known structural features, and review applications of these enzymes to glycobiology.
Kinase-anchoring proteins in ciliary signal transduction
Authors: Gopalan Janani , Wordeman Linda , Scott John D.
Published: April 2021

Historically, the diffusion of chemical signals through the cell was thought to occur within a cytoplasmic soup bounded by the plasma membrane. This theory was predicated on the notion that all regulatory enzymes are soluble and moved with a Brownian motion. Although enzyme compartmentalization was initially rebuffed by biochemists as a ‘last refuge of a scoundrel', signal relay through macromolecular complexes is now accepted as a fundamental tenet of the burgeoning field of spatial biology. A-Kinase anchoring proteins (AKAPs) are prototypic enzyme-organizing elements that position clusters of regulatory proteins at defined subcellular locations. In parallel, the primary cilium has gained recognition as a subcellular mechanosensory organelle that amplifies second messenger signals pertaining to metazoan development. This article highlights advances in our understanding of AKAP signaling within the primary cilium and how defective ciliary function contributes to an increasing number of diseases known as ciliopathies.
Normative Nasalance Values in Vietnamese With Southern Dialect: Vowel and Tone Effects
Authors: Nguyen Duc Minh , Lee Sue Ann S. , Hayakawa Toko , Yamamoto Masahiko , Natsume Nagato
Published: April 2021

Purpose

The purpose of the current study was to examine normative nasalance values in Vietnamese adult speakers with Southern dialect and to investigate the effects of vowels and tones on nasalance. Previous studies examining nasalance have been mainly conducted with Indo-European languages. Limited information on nasalance is available in tone languages other than Chinese. Furthermore, tone and vowel effects on nasalance scores in tone languages have not been fully examined.

Method

Nasalance scores of various speech stimuli including passages, syllables, and prolonged vowels were obtained from Vietnamese-speaking adults with Southern dialect (Mage= 23 years) using a nasometer (KayPENTAX 6450).

Results

The average nasalance scores of Southern Vietnamese adult speakers were 24.16%, 38.17%, and 70.03% for the oral, oral–nasal, and nasal passages, respectively. Southern Vietnamese speakers produced the highest nasalance scores on the vowel /a/, followed by /i/ and /u/. Nasalance scores of stimuli produced with the falling and restricted tone were significantly lower than those produced with the other tones.

Conclusions

The normative nasalance values of the current study will contribute as a reference index for the Vietnamese language. The effects of vowels and tones can also provide insight into the development of nasalance testing stimuli and for characterizing nasalance values across languages.
Online data analysis system of the INTEGRAL telescope
Authors: Neronov A. , Savchenko V. , Tramacere A. , Meharga M. , Ferrigno C. , Paltani S.
Published: April 2021

Context. During more than 17 years of operation in space, the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) telescope has accumulated a large data set that contains records of hard X-ray and soft γ-ray astronomical sources. These data can be reused in the context of multi-wavelength or multi-messenger studies of astronomical sources and have to be preserved on long timescales.

Aims. We present a scientific validation of an interactive online INTEGRAL data analysis system for multi-wavelength studies of hard X-ray and soft γ-ray sources.

Methods. The online data analysis system generates publication-quality high-level data products: sky images, spectra, and light curves in response to user queries that define analysis parameters such as source position, time and energy interval, and binning. The data products can be requested via a web browser interface or via an application programming interface that is available as a Python package. The products for the Imager on Board the INTEGRAL Satellite/INTEGRAL Soft Gamma-Ray Imager instrument of INTEGRAL are generated using the offline science analysis (OSA) software, which is provided by the instrument teams and is conventionally used to analyse INTEGRAL data. The analysis workflow is organised to preserve and reuse various intermediate analysis products, ensuring that frequently requested results are available without delay. The platform is implemented in a Docker cluster that allows operation of the software in a controlled virtual environment and can be deployed in any compatible infrastructure. The scientific results produced by the open data analysis (ODA) are identical to those produced by OSA because ODA simply provides a platform to retrieve the OSA results online while leveraging a provenance-indexed database of precomputed (cached) results to optimise and reuse the result.

Results. We report the functionalities and performance of the online data analysis system by reproducing the benchmark INTEGRAL results on different types of sources, including bright steady and transient Galactic sources, and bright and weak variable extra-galactic sources. We compare the results obtained with the online data analysis system with previously published results on these sources. We also discuss limitations of the online analysis system.

Conclusions. We consider the INTEGRAL online data analysis as a demonstration of a more general web-based ‘data analysis as a service’ approach that provides a promising solution for the preservation and maintenance of data analysis tools of astronomical telescopes on (multi)decade long timescales and facilitates combining data in multi-wavelength and multi-messenger studies of astronomical sources.
The effects of the initial mass function on Galactic chemical enrichment
Authors: Goswami S. , Slemer A. , Marigo P. , Bressan A. , Silva L. , Spera M. , Boco L. , Grisoni V. , Pantoni L. , Lapi A.
Published: April 2021

Context. We have been seeing mounting evidence that the stellar initial mass function (IMF) might extend far beyond the canonical Mi ∼ 100 M⊙ limit, but the impact of such a hypothesis on the chemical enrichment of galaxies is yet to be clarified.

Aims. We aim to address this question by analysing the observed abundances of thin- and thick-disc stars in the Milky Way with chemical evolution models that account for the contribution of very massive stars dying as pair instability supernovae.

Methods. We built new sets of chemical yields from massive and very massive stars up to Mi ∼ 350 M⊙ by combining the wind ejecta extracted from our hydrostatic stellar evolution models with explosion ejecta from the literature. Using a simple chemical evolution code, we analysed the effects of adopting different yield tables by comparing predictions against observations of stars in the solar vicinity.

Results. After several tests, we set our focus on the [O/Fe] ratio that best separates the chemical patterns of the two Milky Way components. We find that with a standard IMF, truncated at Mi ∼ 100 M⊙, we can reproduce various observational constraints for thin-disc stars; however, the same IMF fails to account for the [O/Fe] ratios of thick-disc stars. The best results are obtained by extending the IMF up to Mi = 350 M⊙, while including the chemical ejecta of very massive stars in the form of winds and pair instability supernova (PISN) explosions.

Conclusions. Our study indicates that PISN may have played a significant role in shaping the chemical evolution of the thick disc of the Milky Way. Including their chemical yields makes it easier to reproduce not only the level of the α-enhancement, but also the observed slope of thick-disc stars in the [O/Fe] vs. [Fe/H] diagram. The bottom line is that the contribution of very massive stars to the chemical enrichment of galaxies is potentially quite important and should not be neglected in models of chemical evolution.
Shape and connectivity of groups and clusters: Effect of the dynamical state and accretion history
Authors: Gouin C. , Bonnaire T. , Aghanim N.
Published: April 2021

Matter distribution around clusters is highly anisotropic because clusters are the nodes of the cosmic web. The shape of the clusters and the number of filaments to which they are connected, that is, their connectivity, is thought to reflect their level of anisotropic matter distribution and must in principle be related to their physical properties. We investigate the effect of the dynamical state and the formation history on both the morphology and local connectivity of about 2400 groups and clusters of galaxies from the large hydrodynamical simulation IllustrisTNG at z = 0. We find that the mass of groups and clusters mainly affects the geometry of the matter distribution: Massive halos are significantly more elliptical and are more strongly connected to the cosmic web than low-mass halos. Beyond the mass-driven effect, ellipticity and connectivity are correlated and are imprints of the growth rate of groups and clusters. Both anisotropy measures appear to trace different dynamical states, such that unrelaxed groups and clusters are more elliptical and more connected than relaxed ones. This relation between matter anisotropies and dynamical state is the sign of different accretion histories. Relaxed groups and clusters have mostly been formed a long time ago and are slowly accreting matter at the present time. They are highly spherical and weakly connected to their environment, mostly because they had enough time to relax and thus lost the connection with their preferential directions of accretion and merging. In contrast, late-formed unrelaxed objects are highly anisotropic with strong connectivities and ellipticities. These groups and clusters are in their formation phase and must be strongly affected by the infalling of materials from filaments.
Stability of solar atmospheric structures harboring standing slow waves
Authors: Geeraerts M. , Van Doorsselaere T.
Published: April 2021

Context.In the context of the solar coronal heating problem, one possible explanation for the high coronal temperature is the release of energy by magnetohydrodynamic (MHD) waves. The energy transfer is believed to be possible, among others, by the development of the Kelvin-Helmholtz instability (KHI) in coronal loops.

Aims.Our aim is to determine if standing slow waves in solar atmospheric structures such as coronal loops, and also prominence threads, sunspots, and pores, can trigger the KHI due to the oscillating shear flow at the structure’s boundary.

Methods.We used linearized nonstationary MHD to work out an analytical model in a cartesian reference frame. The model describes a compressible plasma near a discontinuous interface separating two regions of homogeneous plasma, each harboring an oscillating velocity field with a constant amplitude which is parallel to the background magnetic field and aligned with the interface. The obtained analytical results were then used to determine the stability of said interface, both in coronal and photospheric conditions.

Results.We find that the stability of the interface is determined by a Mathieu equation. In function of the parameters of this equation, the interface can either be stable or unstable. For coronal as well as photospheric conditions, we find that the interface is stable with respect to the KHI. Theoretically, it can, however, be unstable with respect to a parametric resonance instability, although it seems physically unlikely. We conclude that, in this simplified setup, a standing slow wave does not trigger the KHI without the involvement of additional physical processes.
Les métabokines, des médiateurs essentiels de l’immunité anti-infectieuse
Authors: Cezard Adeline , Monard Sarah , Bréa-Diakite Déborah , Guillon Antoine , Si-Tahar Mustapha
Published: April 2021

Longtemps cloisonnés dans des domaines de recherche distincts, métabolisme énergétique et immunité ont un lien étroit, récemment mis en exergue par le concept d’immunométabolisme. Dans un contexte infectieux, des reprogrammations métaboliques peuvent en effet survenir dans les cellules immunitaires et aboutir à l’accumulation de divers métabolites, dont certains, appelés métabokines, possèdent des propriétés inattendues d’immunorégulation et de défense antimicrobienne. Ils jouent un rôle crucial dans l’immunité anti-infectieuse, en régulant la réponse des cellules immunitaires de l’hôte, mais aussi en ciblant directement ou indirectement les microorganismes pathogènes.
Signalisation impliquant la neuropiline dans les neurones sécrétant la GnRH
Authors: Vanacker Charlotte , Bouret Sébastien G. , Giacobini Paolo , Prévot Vincent
Published: April 2021

La survie d’une espèce dépend de deux processus intimement liés : la reproduction, d’une part, et l’équilibre entre les besoins énergétiques et l’approvisionnement en sources d’énergie par l’alimentation, d’autre part. Ces deux processus sont contrôlés dans le cerveau par l’hypothalamus, qui produit des neurohormones agissant sur l’hypophyse pour piloter diverses fonctions physiologiques. L’une de ces neurohormones, la GnRH, contrôle non seulement la maturation et le fonctionnement des organes reproducteurs, incluant les ovaires et les testicules, lors de la puberté et à l’âge adulte, mais aussi l’attirance sexuelle. De récentes découvertes suggèrent que la signalisation impliquant la neuropiline-1 dans les neurones sécrétant la GnRH jouerait un rôle charnière dans la coordination du neurodéveloppement et des adaptations physiologiques et comportementales nécessaires au déclenchement de la puberté et à l’acquisition de la fonction de reproduction. Dans cet article de synthèse, nous replaçons ces découvertes dans le contexte de récents travaux montrant que les voies de signalisation des sémaphorines de classe 3 sont impliquées dans la physiopathologie non seulement de l’infertilité, mais aussi de l’obésité. Nous discutons également l’implication potentielle des neurones produisant la GnRH dans la perception des odeurs sociales et dans la précocité de la maturation sexuelle. L’hypothèse selon laquelle l’activité de ces neurones au cours du développement postnatal constituerait le chaînon manquant entre la prise de poids, le déclenchement de la puberté et le comportement sexuel, ouvre la voie à une meilleure compréhension de l’implication de l’homéostasie énergétique dans la maturation sexuelle, et pourrait aussi avoir des implications thérapeutiques pour la puberté précoce.
SIARD model and effect of lockdown on the dynamics of COVID-19 disease with non total immunity
Authors: Aziz-Alaoui M.A. , Najm F. , Yafia R.
Published: April 2021

We propose a new compartmental mathematical model describing the transmission and the spreading of COVID-19 epidemic with a special focus on the non-total immunity. The model(called SIARD)is given by a system of differential equations which model the interactions between five populations “susceptible”, “reported infectious”, “unreported infectious”, “recovered with/without non total immunity” and “death”. Depending on the basic reproduction number, we prove that the total immunity induces local stability-instability of equilibria and the epidemic may disappear after a first epidemic wave and more epidemic waves may appear in the case of non-total immunity. Using the sensitivity analysis we identify the most sensitive parameters. Numerical simulations are carried out to illustrate our theoretical results. As an application, we found that our model fits well the Moroccan epidemic wave, and predicts more than one wave for French case.
Enantioselective Functionalization of Prochiral Cyclobutanones and Cyclobutenones
Authors: Lu Ping , Wang Meng , Zhong Changxu
Published: April 2021

Enantioselective synthesis of cyclobutane derivatives is still a challenging topic in asymmetric synthesis. [2+2] Cycloaddition and skeleton rearrangement are two primary strategies to this end. Recently, functionalization of cyclobutanones and cyclobutenones, which are readily available via [2+2] cycloadditions as prochiral substrates, has emerged as a powerful tool to access versatile four-membered ring compounds. Herein, we summarize some recent advances in these areas from our and other groups.

1 Introduction

2 Enantioselective Functionalization of Cyclobutanones

2.1 Chiral Lithium Amide Approach

2.2 Enamine Approach

3 Enantioselective Functionalization of Cyclobutenones

4 Conclusion
Graphene-induced positive shift of the flat band voltage in recessed gate AlGaN/GaN structures
Authors: Liu Xiaobo , Zheng Li , Cheng Xinhong , Shen Lingyan , Liu Shaoyu , Wang Da , You Jinhao , Yu Yuehui
Published: April 2021

In this work, a layer of graphene is inserted into Al2O3/recessed gate AlGaN/GaN structures to realize the positive shift of flatband voltage VFB. With a chemically inert surface and a high work function, graphene suppresses the interfacial layer growth, reduces the donor-like interface defects during the growth of Al2O3 gate dielectrics, provides a potential well to confine electrons from AlGaN and the interface defects, lifts the conduction band of GaN, leads to the disappearance of 2DEG at recessed AlGaN/GaN interface, and positively shifts VFB from 1.4 V to 5.2 V. This method provides a promising solution to fabricate E-mode AlGaN/GaN high electron mobility transistor.
Simultaneously enhanced reaction temperature and velocity of self-propagating high-temperature synthesis via Joule-heat induced multi-channel heat flow
Authors: Luo Cheng , Zhang Yansong
Published: April 2021

Simultaneous enhancement of reaction temperature and velocity of self-propagating high-temperature synthesis is still a challenge. Here, we propose a general method based on the Joule-heat induced multi-channel heat flow to simultaneously increase the reaction temperature and velocity of self-propagating high-temperature synthesis. A designed surface structure induces multi-channel Joule-heat accumulation at the surface of reaction components and subsequently multi-channel heat flow during the self-propagating processes. Multi-channel heat flow leads to the formation of two combustion stages: the self-propagating process and the Joule-heat induced grain growth, leading to an enhancement of the maximum reaction temperature up to 67%. Meanwhile, multi-channel heat flow will reduce the propagation distance of the reaction wave and the heat conduction between heat flow channels will increase the temperature of the reaction components, in turn, resulting in an increase in the reaction velocity that is five times higher. We expect that our findings will pave the way for the future application of self-propagating high-temperature synthesis in industries.
Observations of a plectonemic configuration in a stable magnetized plasma jet
Authors: Lavine Eric Sander , You Setthivoine
Published: April 2021

Astrophysical jets are collimated high-speed outflows emerging from spinning and accreting matter around celestial objects and may spontaneously result from self-organized processes. Magnetic self-organization is commonly observed in laboratory plasma physics experiments; however, they require close-fitting flux conservers to constrain and stabilize the toroidal or cylindrical structures. Here we report the first observations of a long, stable, free-boundary plasma jet far from chamber walls, embedding a double-helix magnetic structure resembling a force-free plectonemic Taylor state. The jets arise from an experimental setup that mimics an accretion disk and has no close-fitting solid flux conserver. The results support the hypothesis that self-organization could be a universal, intrinsic explanation for jet formation, collimation, and stability and may help explain double-helix features in celestial observations.
Dependence of nonlinear response and magnon scattering on material properties
Authors: Qu T. , Venugopal Aneesh , Victora R. H.
Published: April 2021

Magnon scattering studies can play a crucial role in revealing fundamental aspects of magnon physics. Due to the nonlinear nature of scattering, such studies are also important for applications ranging from traditional microwave signal processing to novel magnon-based computation. In this work, simulations employing realistic material parameters are used to demonstrate the tunable nature of magnon-based nonlinear properties. The changes are affected through modification of the dispersion relation of the magnetic system. It is demonstrated that the magnon nonlinear response is very sensitive to the sample film thickness while showing a relatively weaker dependence on saturation magnetization. Aside from the contributions to the fundamental understanding of magnons, the results presented are useful for establishing design rules for magnon-based applications.
A bright source of telecom single photons based on quantum frequency conversion
Authors: Morrison Christopher L. , Rambach Markus , Koong Zhe Xian , Graffitti Francesco , Thorburn Fiona , Kar Ajoy K. , Ma Yong , Park Suk-In , Song Jin Dong , Stoltz Nick G. , Bouwmeester Dirk , Fedrizzi Alessandro , Gerardot Brian D.
Published: April 2021

On-demand indistinguishable single-photon sources are essential for quantum networking and communication. Semiconductor quantum dots are among the most promising candidates, but their typical emission wavelength renders them unsuitable for use in fiber networks. Here, we present quantum frequency conversion of near-infrared photons from a bright quantum dot to the telecommunication C-band, allowing integration with existing fiber architectures. We use a custom-built, tunable 2400 nm seed laser to convert single photons from 942 nm to 1550 nm in a difference-frequency generation process. We achieve an end-to-end conversion efficiency of ≃35%, demonstrate count rates approaching 1 MHz at 1550 nm with g(2)(0)=0.043(1), and achieve Hong-Ou-Mandel (HOM) visibilities of 60%. We expect this scheme to be preferable to quantum dot sources directly emitting at telecom wavelengths for fiber-based quantum networking.
Time-resolved imaging of Œrsted field induced magnetization dynamics in cylindrical magnetic nanowires
Authors: Schöbitz M. , Finizio S. , De Riz A. , Hurst J. , Thirion C. , Gusakova D. , Toussaint J.-C. , Bachmann J. , Raabe J. , Fruchart O.
Published: April 2021

Recent studies in three-dimensional spintronics propose that the Œrsted field plays a significant role in cylindrical nanowires. However, there is no direct report on its impact on magnetic textures. Here, we use time-resolved scanning transmission x-ray microscopy to image the dynamic response of magnetization in cylindrical Co30Ni70 nanowires subjected to nanosecond Œrsted field pulses. We observe the tilting of longitudinally magnetized domains toward the azimuthal Œrsted field direction and create a robust model to reproduce the differential magnetic contrasts and extract the angle of tilt. Furthermore, we report the compression and expansion, or breathing, of a Bloch-point domain wall that occurs when weak pulses with opposite signs are applied. We expect that this work lays the foundation for and provides an incentive to further studying complex and fascinating magnetization dynamics in nanowires, especially the predicted ultra-fast domain wall motion and associated spin wave emissions.
A benchmark study on the axial velocity profile of wave propagation in deformable blood vessels
Authors: Hasan Md. , Patel B. P. , Pradyumna S.
Published: April 2021

Wave propagation models in the time domain have been extensively used in the available literature to study the flow characteristics in blood vessels. Most of the wave propagation models have considered flat or parabolic velocity profile functions to estimate the nonlinear convection and diffusion terms present in the conservation of momentum equation. There are only a few works available on the wave propagation analysis in which the velocity profile is approximated using different polynomial functions. In this study, a computationally efficient nonlinear axisymmetric formulation is presented without a priori assumed velocity profile function across the cross section to model the blood flow. Such a formulation in terms of axial velocity (u), pressure (p), and domain radius (R) facilitates the evolution/development of axial velocity profile as the flow progresses with time. The arterial mechanical behavior is modeled using a linear elastic constitutive relation. Partial differential equations are discretized using the finite element method and the Galerkin time integration technique in space and time domains, respectively. This study finds a phase difference between the shear stress at the wall and the flow rate. The flow characteristics and the velocity profile function are found to be in good agreement with the three-dimensional computational results available in the literature. The detailed investigation of the axial velocity across the cross section reveals neither flat nor parabolic profiles, as previously assumed in the literature.
Micro-scale technologies propel biology and medicine
Authors: Pereiro Iago , Aubert Julien , Kaigala Govind V.
Published: April 2021

Historically, technology has been central to new discoveries in biology and progress in medicine. Among various technologies, microtechnologies, in particular, have had a prominent role in the revolution experienced by the life sciences in the last few decades, which will surely continue in the years to come. In this Perspective, we illustrate how microtechnologies, with a focus on microfluidics, have evolved in trends/waves to tackle the boundary of knowledge in the life sciences. We provide illustrative examples of technology-enabled biological breakthroughs and their current and future use in clinics. Finally, we take a closer look at the translational process to understand why the incorporation of new micro-scale technologies in medicine has been comparatively slow so far.
Dimensionality dependence of the Kauzmann temperature: A case study using bulk and confined water
Authors: Moid Mohd , Sastry Srikanth , Dasgupta Chandan , Pascal Tod A. , Maiti Prabal K.
Published: April 2021

The Kauzmann temperature (TK) of a supercooled liquid is defined as the temperature at which the liquid entropy becomes equal to that of the crystal. The excess entropy, the difference between liquid and crystal entropies, is routinely used as a measure of the configurational entropy, whose vanishing signals the thermodynamic glass transition. The existence of the thermodynamic glass transition is a widely studied subject, and of particular recent interest is the role of dimensionality in determining the presence of a glass transition at a finite temperature. The glass transition in water has been investigated intensely and is challenging as the experimental glass transition appears to occur at a temperature where the metastable liquid is strongly prone to crystallization and is not stable. To understand the dimensionality dependence of the Kauzmann temperature in water, we study computationally bulk water (three-dimensions), water confined in the slit pore of the graphene sheet (two-dimensions), and water confined in the pore of the carbon nanotube of chirality (11,11) having a diameter of 14.9 Å (one-dimension), which is the lowest diameter where amorphous water does not always crystallize into nanotube ice in the supercooled region. Using molecular dynamics simulations, we compute the entropy of water in bulk and under reduced dimensional nanoscale confinement to investigate the variation of the Kauzmann temperature with dimension. We obtain a value of TK (133 K) for bulk water in good agreement with experiments [136 K (C. A. Angell, Science 319, 582–587 (2008) and K. Amann-Winkel et al., Proc. Natl. Acad. Sci. U. S. A. 110, 17720–17725 (2013)]. However, for confined water, in two-dimensions and one-dimension, we find that there is no finite temperature Kauzmann point (in other words, the Kauzmann temperature is 0 K). Analysis of the fluidicity factor, a measure of anharmonicity in the oscillation of normal modes, reveals that the Kauzmann temperature can also be computed from the difference in the fluidicity factor between amorphous and ice phases.
Coordination compounds of biogenic metals as cytotoxic agents in cancer therapy
Authors: Guk Dmitry A. , Krasnovskaya Olga O. , Beloglazkina Elena K.
Published: April 2021

The review summarizes the data on the structures and methods for the synthesis of compounds with anticancer activity based on biogenic metals, which can replace platinum drugs prevailing in cytotoxic therapy. The main focus is given to the comparison of the mechanisms of the cytotoxic action of these complexes, their efficacy and prospects of their use in clinical practice. This is the first systematic review of cytotoxic zinc, iron, cobalt and copper compounds. The structure – activity relationships and the mechanisms of antitumour action are formulated for each type of metal complexes.

The bibliography includes 181 references.