bluuebunny/crossref_metadata_2025 huggingface dataset:
Drug-encapsulated blend of PLGA-PEG microspheres: in vitro and in vivo study of the effects of localized/targeted drug delivery on the treatment of triple-negative breast cancer
Authors: Jusu S. M. , Obayemi J. D. , Salifu A. A. , Nwazojie C. C. , Uzonwanne V. , Odusanya O. S. , Soboyejo W. O.
Published: August 2020

Triple-negative breast cancer (TNBC) is more aggressive and difficult to treat using conventional bulk chemotherapy that is often associated with increased toxicity and side effects. In this study, we encapsulated targeted drugs [A bacteria-synthesized anticancer drug (prodigiosin) and paclitaxel] using single solvent evaporation technique with a blend of FDA-approved poly lactic-co-glycolic acid-polyethylene glycol (PLGA_PEG) polymer microspheres. These drugs were functionalized with Luteinizing Hormone-Releasing hormone (LHRH) ligands whose receptors are shown to overexpressed on surfaces of TNBC. The physicochemical, structural, morphological and thermal properties of the drug-loaded microspheres were then characterized using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Dynamic Light Scattering (DLS), Nuclear Magnetic Resonance Spectroscopy (NMR), Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC). Results obtained from in vitro kinetics drug release at human body temperature (37 °C) and hyperthermic temperatures (41 and 44 °C) reveal a non-Fickian sustained drug release that is well-characterized by Korsmeyer-Peppas model with thermodynamically non-spontaneous release of drug. Clearly, the in vitro and in vivo drug release from conjugated drug-loaded microspheres (PLGA-PEG_PGS-LHRH, PLGA-PEG_PTX-LHRH) is shown to result in greater reductions of cell/tissue viability in the treatment of TNBC. The in vivo animal studies also showed that all the drug-loaded PLGA-PEG microspheres for the localized and targeted treatment of TNBC did not caused any noticeable toxicity and thus significantly extended the survival of the treated mice post tumor resection. The implications of this work are discussed for developing targeted drug systems to treat and prevent local recurred triple negative breast tumors after surgical resection.
Atrogin1-induced loss of aquaporin 4 in myocytes leads to skeletal muscle atrophy
Authors: Chung Seok Won , Kim Ja-Yeon , Yoon Jong Pil , Suh Dong Won , Yeo Woo Jin , Lee Yong-Soo
Published: August 2020

The water channel aquaporin 4 (AQP4) regulates the flux of water across the cell membrane, maintaining cellular homeostasis. Since AQP4 is enriched in the sarcolemma of skeletal muscle, a functional defect in AQP4 may cause skeletal muscle dysfunction. To investigate a novel mechanism underlying skeletal muscle atrophy, we examined AQP4 expression and its regulation in muscle using the rotator cuff tear (RCT) model. Human and mouse AQP4 expression was significantly decreased in atrophied muscle resulting from RCT. The size and the number of myotubes were reduced following AQP4 knockdown. Atrogin 1-mediated ubiquitination of AQP4 was verified with an ubiquitination assay after immunoprecipitation of AQP4 with an anti-AQP4 antibody. In this study, we identified high mobility group box 1 (HMGB1) as a potent upstream regulator of atrogin 1 expression. Atrogin 1 expression was increased by recombinant mouse HMGB1 protein, and the HMGB1-induced atrogin 1 expression was mediated via NF-κB signaling. Our study suggests that loss of AQP4 appears to be involved in myocyte shrinkage after RCT, and its degradation is mediated by atrogin 1-dependent ubiquitination. HMGB1, in its function as a signaling molecule upstream of the ubiquitin ligase atrogin 1, was found to be a novel regulator of muscle atrophy.
Whole transcriptome analysis of bovine mammary progenitor cells by P-Cadherin enrichment as a marker in the mammary cell hierarchy
Authors: Martignani E. , Ala U. , Sheehy P. A. , Thomson P. C. , Baratta M.
Published: August 2020

Adult bovine mammary stem cells possess the ability to regenerate in vivo clonal outgrowths that mimic functional alveoli. Commonly available techniques that involve immunophenotype-based cell sorting yield cell fractions that are moderately enriched, far from being highly purified. Primary bovine mammary epithelial cells segregated in four different populations according to the expression of P-Cadherin and CD49f. Sorted cells from each fraction were tested for the presence of lineage-restricted progenitors and stem cells. Only cells from the CD49fhigh/P-Cadherinnegsubpopulation were able to give rise to both luminal- and myoepithelial-restricted colonies in vitro and generate organized outgrowths in vivo, which are hallmarks of stem cell activity. After whole transcriptome analysis, we found gene clusters to be differentially enriched that relate to cell-to-cell communication, metabolic processes, proliferation, migration and morphogenesis. When we analyzed only the genes that were differentially expressed in the stem cell enriched fraction, clusters of downregulated genes were related to proliferation, while among the upregulated expression, cluster of genes related to cell adhesion, migration and cytoskeleton organization were observed. Our results show that P-Cadherin separates mammary subpopulations differentially in progenitor cells or mammary stem cells. Further we provide a comprehensive observation of the gene expression differences among these cell populations which reinforces the assumption that bovine mammary stem cells are typically quiescent.
Promoting photocatalytic hydrogen evolution over the perovskite oxide Pr0.5(Ba0.5Sr0.5)0.5Co0.8Fe0.2O3 by plasmon-induced hot electron injection
Authors: Li Zhishan , Zhang Qimeng , Li Jian-Gang , Sun Huachuan , Yuen Muk-Fung , Jiang Shenglin , Tian Yang , Hong Guo , Wang Chundong , Liu Meilin
Published: August 2020

Exploration of highly efficient and stable photocatalysts for water splitting has attracted much attention.
Rapid quantification of ruthenium(ii) polypyridyl anti-cancer drugs using a selective ligand dissociation LC-MS/MS method
Authors: Mehanna Stephanie , Bodman-Smith Kikki , Daher Costantine F. , Khnayzer Rony S.
Published: August 2020

This study validates a rapid LC-MS/MS method for the quantification of Ru(ii) bipyridyl complexes in biological matrices, using selective ligand dissociation.
Pb(OF)Cu3(SeO3)2(NO3): a selenite fluoride nitrate with a breathing kagomé lattice
Authors: Zhang Mengsi , Zhao Zhiying , Zhang Wanwan , Li Jinyang , Huang Xiaoying , He Zhangzhen
Published: August 2020

A spin-1/2 breathing kagomé compound Pb(OF)Cu3(SeO3)2(NO3) exhibits ferromagnetic interactions inside the layers and antiferromagnetic interactions between the neighboring layers.
Influence of rare earth elements (REEs) on the structure and optical properties of lithium zirconium phosphate (LZP)
Authors: Nataliia Gorodylova , Veronika Kosinová , Petra Šulcová
Published: August 2020

The objective of presented study was to verify the concept of the formation of the REE–LZP solid solutions according to two different substitution models and to examine optical absorption properties of the samples for pigment application.
One-step vapour phase growth of two-dimensional formamidinium-based perovskite and its hot carrier dynamics
Authors: Erkılıç Ufuk , Ji Hyun Goo , Nishibori Eiji , Ago Hiroki
Published: August 2020

Square-shaped layered FA2PbI4 perovskite crystals were prepared using a one-step vapour deposition method, and the hot carrier dynamics of these crystals was studied.
Exceptional mechano-electronic properties in the HfN2 monolayer: a promising candidate in low-power flexible electronics, memory devices and photocatalysis
Authors: Mohanta Manish Kumar , Fathima I. S. , De Sarkar Abir
Published: August 2020

The response of the electronic properties of the HfN2 monolayer to external perturbation such as strain and electric fields has been investigated using density functional theory calculations for its device-based applications and photocatalysis.
Mobility of liquids intercalated into the interplane space of graphite oxide as revealed by a combination of 19F NMR, 1H NMR and EPR spin probe methods
Authors: Chumakova Natalia A. , Tkachev Yaroslav V. , Vorobiev Andrey Kh. , Rebrikova Anastasya T. , Korobov Mikhail V.
Published: August 2020

A combination of 19F and 1H NMR with the Carr–Purcell–Meiboom–Gill (CPMG) pulse sequence was used to examine the mobility of liquids in the interplane space of graphite oxide (GO) for the first time.
An approach to calculate the free energy changes of surface reactions using free energy decomposition on ab initio brute-force molecular dynamics trajectories
Authors: Xu Jiayan , Huang Hao , Hu P.
Published: August 2020

To understand the mechanisms and kinetics of catalytic reactions in heterogeneous catalysis, ab initio molecular dynamics is one of the powerful methods used to explore the free energy surface (FES) of surface elementary steps.
A novel AB3-type trimeric zinc(ii)-phthalocyanine as an electrochromic and optical limiting material
Authors: Işık Büyükekşi Sebile , Karatay Ahmet , Orman Efe Baturhan , Açar Selçuki Nursel , Özkaya Ali Rıza , Salih Bekir , Elmali Ayhan , Şengül Abdurrahman
Published: August 2020

A novel asymmetric AB3-type trinuclear zinc(ii)-phthalocyanine is reported, showing good electrochromic and optical limiting properties.
Activity and selectivity of CO2 photoreduction on catalytic materials
Authors: Yin Wen-Jin , Wen Bo , Ge Qingxia , Li Xi-Bo , Teobaldi Gilberto , Liu Li-Min
Published: August 2020

Photoreduction of molecular CO2 by solar light into added-value fuels or chemical feedstocks is an appealing strategy to simultaneously overcome environmental problems and energy challenges.
Vitamin D and non-alcoholic fatty liver disease: a meta-analysis of randomized controlled trials
Authors: Guo Xiao-fei , Wang Chong , Yang Ting , Li Shan , Li Ke-lei , Li Duo
Published: August 2020

The results of randomized controlled trials (RCTs) investigating supplemental vitamin D on aminotransferases and cardio-metabolic risk factors in subjects with non-alcoholic fatty liver disease (NAFLD) have been inconsistent.
Maternal serine supply from late pregnancy to lactation improves offspring performance through modulation of metabolic pathways
Authors: He Liuqin , Liu Yonghui , Long Jing , Zhou Xihong , Zeng Sijing , Li Tiejun , Yin Yulong
Published: August 2020

The key metabolic pathway of the different metabolites affected by maternal dietary serine.
Melatonin as an inducer of arecoline and their coordinated roles in anti-oxidative activity and immune responses
Authors: Yin Xiaojian , Wei Yunxie , Song Wei , Zhang He , Liu Guoyin , Chen Yan , Li Lan-Zhu , Alolga Raphael N. , Ma Gaoxiang , Reiter Russel J. , Li Jia , Shi Haitao
Published: August 2020

Melatonin and it induced arecoline in arecoline play coordinated roles in immune responses.
Experimental and theoretical study of bidirectional photoswitching behavior of 5,5′-diphenylhydantoin Schiff bases: synthesis, crystal structure and kinetic approaches
Authors: Todorov Petar , Georgieva Stela , Peneva Petia , Rusew Rusi , Shivachev Boris , Georgiev Anton
Published: August 2020

Herein, the synthesis and characterization of four novel 5,5′-diphenylhydantoin Schiff bases containing different aromatic species are presented.
A novel berberine-based colorimetric and fluorimetric probe for hydrazine detection
Authors: Ruan Shutang , Gao Yu , Wang Yunyun , Li Mingxin , Yang Haiyan , Song Jie , Wang Zhonglong , Wang Shifa
Published: August 2020

Hydrazine in water and soil has caused serious diseases for human health. In this work, a simple fluorescent probe (BP) for hydrazine detection was synthesized from berberine. The probe has excellent fluorescence properties and naked-eye detection.
A robust 3D In–MOF with an imidazole acid ligand as a fluorescent sensor for sensitive and selective detection of Fe3+ ions
Authors: Cen Peipei , Liang Chen , Duan Lijuan , Wang Meilin , Tian Danian , Liu Xiangyu
Published: August 2020

A stable In(iii)-MOF with a versatile 5-(1H-imidazol-1-yl)isophthalic acid ligand can be used as a fluorescent sensor for Fe3+ detection.
Synthetic strategies towards mechanically interlocked oligomers and polymers
Authors: Hoyas Pérez Nadia , Lewis James E. M.
Published: August 2020

Synthetic methodologies towards the preparation of oligomeric and polymeric mechanically interlocked molecules are described, including both covalent strategies and self-assembly approaches.
Identifying competitive tin- or metal-free catalyst combinations to tailor polyurethane prepolymer and network properties
Authors: Arnould Priscilla , Bosco Lionel , Sanz Federico , Simon Frédéric N. , Fouquay Stéphane , Michaud Guillaume , Raynaud Jean , Monteil Vincent
Published: August 2020

Polyurethane-based mastics, industrially obtainedviaa prepolymerization/crosslinking process, benefit from catalyst selection at both stages.
Discovery of mercaptopropanamide-substituted aryl tetrazoles as new broad-spectrum metallo-β-lactamase inhibitors
Authors: Yan Yu-Hang , Chen Jian , Zhan Zhen , Yu Zhu-Jun , Li Gen , Guo Li , Li Guo-Bo , Wu Yong , Zheng Yongxiang
Published: August 2020

Compound 13a showed IC50 values of 0.044 μM, 0.396 μM and 0.71 μM against VIM-2, NDM-1 and IMP-1 MBL, respectively. It binds to chelates via active site zinc ions and forms interactions with residues on the L1 and L3 loops of VIM-2.
The role of motivation on secondary school students’ causal attributions to choose or abandon chemistry
Authors: Ardura Diego , Zamora Ángela , Pérez-Bitrián Alberto
Published: August 2020

The present investigation aims to analyze the effect of motivation on students’ causal attributions to choose or abandon chemistry when it first becomes optional in the secondary education curriculum in Spain. Attributions to the effect of the family and to the teacher and classroom methodology were found to be common predictors of the choice to all the students in the sample. However, our analyses point to a significant effect of the students’ motivation in other types of attributions. In the case of at-risk of abandonment students, specific causal attributions to the effect of friends and to the subject's relationship with mathematics were found. On the other hand, the effect of media was a significant predictor only in the case of highly-motivated students. Our study provides several suggestions for teachers, schools, and administrations to design counseling strategies to help students make the right choices.
Rational design of a “dual lock-and-key” supramolecular photosensitizer based on aromatic nucleophilic substitution for specific and enhanced photodynamic therapy
Authors: Teng Kun-Xu , Niu Li-Ya , Kang Yan-Fei , Yang Qing-Zheng
Published: August 2020

The “dual lock-and-key” supramolecular photosensitizers enable specific and enhanced photodynamic therapy (PDT).
Cytosine-5 methylation-directed construction of a Au nanoparticle-based nanosensor for simultaneous detection of multiple DNA methyltransferases at the single-molecule level
Authors: Wang Li-Juan , Han Xiao , Qiu Jian-Ge , Jiang BingHua , Zhang Chun-Yang
Published: August 2020

Cytosine-5 methylation-directed construction of Au nanoparticle-based nanosensors enables specific and sensitive detection of multiple DNA methyltransferases.
Dynamics of island-meniscus coalescence in free-standing smectic films
Authors: Dolganov P. V. , Shuravin N. S. , Dolganov V. K. , Kats E. I.
Published: August 2020

In free-standing smectic films coalescence of 2D islands (domains of larger thickness) with the 3D meniscus is characterized by nontrivial time dependence of the domain form and its dimensions H, W, and L.
Precise control of cyclodextrin-based pseudo-polyrotaxane lamellar structureviaaxis polymer composition
Authors: Uenuma Shuntaro , Maeda Rina , Yokoyama Hideaki , Ito Kohzo
Published: August 2020

In the stacked nanosheets composed of β-CD and triblock copolymers, the thickness of the EO layers increases linearly with increasing number of EO units, which indicate the EO chains take a brush conformation.
A phenyl-removal strategy for accessing an efficient dual-state emitter in the red/NIR region guided by TDDFT calculations
Authors: Xia Guomin , Shao Qingqing , Liang Kangli , Wang Yigang , Jiang Lixia , Wang Hongming
Published: August 2020

We report here a phenyl-removal strategy in TPE-merged squaraine dyes for accessing intense red/NIR emission in both solution and crystalline states, guided by in-depth TDDFT calculations.
MiR-940 promotes malignant progression of breast cancer by regulating FOXO3
Authors: Zhang Huayao , Peng Jingwen , Lai Jianguo , Liu Haiping , Zhang Zhiyuan , Li Xiangdi , Liang Baozhen , Chen Xuejun , Zou Baojia , Lin Siyuan , Zhang Lihua
Published: August 2020

Breast cancer (BC) is a common cancer with poor survival. The present study aimed to explore the effect of miR-940 on the process of BC cells and its target gene FOXO3. The expression of miR-940 was assessed in BC tissues and cells using qRT-PCR. Furthermore, the correlation between miR-940 and prognosis of BC patients from the TCGA database was analyzed. CCK8 assays and colony formation assays were used to explore the effect of miR-940 on BC cell proliferation. The invasion abilities were detected by transwell assays. Luciferase reporter assay was performed to scrutinize the relationship between miR-940 and FOXO3. Finally, rescue experiments were performed through FOXO3 down-regulation and miR-940 inhibitors by using CCK8 assays, colony formation assays and transwell assays. miR-940 was significantly up-regulated in BC cells and tissues. In addition, the high level of miR-940 correlated with poor survival of BC patients (P=0.023). CCK8 assays, colony formation assays and transwell assays indicated that miR-940 promoted the proliferation and invasion abilities of BC cells. The luciferase reporter assay suggested that miR-940 directly targeted FOXO3. Moreover, we found that the effect of si-FOXO3 was rescued by miR-940 inhibitors in BC cells. miR-940 may promote the proliferation and invasion abilities of BC cells by targeting FOXO3. Our study suggested that miR-940 could be a novel molecular target for therapies against BC.
Identification of biomarkers associated with synovitis in rheumatoid arthritis by bioinformatics analyses
Authors: Li Zhaoyan , Xu Meng , Li Ronghang , Zhu Zhengqing , Liu Yuzhe , Du Zhenwu , Zhang Guizhen , Song Yang
Published: August 2020

Objectives: Rheumatoid arthritis (RA) is the most common inflammatory arthritis in the world, but its underlying mechanism is still unclear. The present study aims to screen and verify the potential biomarkers of RA.

Methods: We searched the Gene Expression Omnibus (GEO) database for synovial expression profiling from different RA microarray studies to perform a systematic analysis. Functional annotation of differentially expressed genes (DEGs) was conducted, including GO enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. The protein–protein interaction (PPI) networks of the DEGs were constructed based on data from the STRING database. The expression levels of the hub genes in normal membranes and RA synovium were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot system.

Results: A total of 444 differential expression genes were identified, including 172 up-regulated and 272 down-regulated genes in RA synovium compared with normal controls. The top ten hub genes; protein tyrosine phosphatase receptor type C (PTPRC), LCK proto-oncogene (LCK), cell division cycle 20 (CDC20), Jun proto-oncogene (JUN), cyclin-dependent kinase 1 (CDK1), kinesin family member 11 (KIF11), epidermal growth factor receptor (epidermal growth factor receptor (EGFR), vascular endothelial growth factor A (VEGFA), mitotic arrest deficient 2 like 1 (MAD2L1), and signal transducer and activator of transcription 1 (STAT1) were identified from the PPI network, and the expression level of VEGFA and EGFR was significantly increased in RA membranes (P<0.05).

Conclusion: Our results indicate that the hub genes VEGFA and EGFR may have essential effects during the development of RA and can be used as potential biomarkers of RA.
Impact of polarised extragalactic sources on the measurement of CMBB-mode anisotropies
Authors: Lagache G. , Béthermin M. , Montier L. , Serra P. , Tucci M.
Published: August 2020

One of the main goals of cosmology is to search for the imprint of primordial gravitational waves in the polarisation filed of the cosmic microwave background to probe inflation theories. One of the obstacles in detecting the primordial signal is that the cosmic microwave backgroundB-mode polarisation must be extracted from among astrophysical contaminations. Most efforts have focus on limiting Galactic foreground residuals, but extragalactic foregrounds cannot be ignored at the large scale (ℓ ≲ 150), where the primordialB-modes are the brightest. We present a complete analysis of extragalactic foreground contamination that is due to polarised emission of radio and dusty star-forming galaxies. We update or use current models that are validated using the most recent measurements of source number counts, shot noise, and cosmic infrared background power spectra. We predict the flux limit (confusion noise) for future cosmic microwave background (CMB) space-based or balloon-borne experiments (IDS, PIPER, SPIDER, LiteBIRD, and PICO), as well as ground-based experiments (C-BASS, NEXT-BASS, QUIJOTE, AdvACTPOL, BICEP3+Keck, BICEPArray, CLASS, Simons Observatory, SPT3G, and S4). The telescope aperture size (and frequency) is the main characteristic that affects the level of confusion noise. Using the flux limits and assuming mean polarisation fractions independent of flux and frequency for radio and dusty galaxies, we computed theB-mode power spectra of the three extragalactic foregrounds (radio source shot noise, dusty galaxy shot noise, and clustering). We discuss their relative levels and compare their amplitudes to that of the primordial tensor modes parametrised by the tensor-to-scalar ratior. At the reionisation bump (ℓ= 5), contamination by extragalactic foregrounds is negligible. While the contamination is much lower than the targeted sensitivity onrfor large-aperture telescopes at the recombination peak (ℓ= 80), it is at a comparable level for some of the medium- (∼1.5 m) and small-aperture telescope (≤0.6 m) experiments. For example, the contamination is at the level of the 68% confidence level uncertainty on the primordialrfor the LiteBIRD and PICO space-based experiments. These results were obtained in the absence of multi-frequency component separation (i.e. considering each frequency independently). We stress that extragalactic foreground contaminations have to be included in the input sky models of component separation methods dedicated to the recovery of the CMB primordialB-mode power spectrum. Finally, we also provide some useful unit conversion factors and give some predictions for the SPICA B-BOP experiment, which is dedicated to Galactic and extragalactic polarisation studies. We show that SPICA B-BOP will be limited at 200 and 350μm by confusion from extragalactic sources for long integrations in polarisation, but very short integrations in intensity.
High-redshift galaxy groups as seen by ATHENA/WFI
Authors: Zhang Chaoli , Ramos-Ceja Miriam E. , Pacaud Florian , Reiprich Thomas H.
Published: August 2020

Context. The first massive galaxy groups in the Universe are predicted to have formed at redshifts well beyond two. Baryonic physics, like stellar and active galactic nuclei (AGN) feedback in this very active epoch, are expected to have left a strong imprint on the thermo-dynamic properties of these early galaxy groups. Therefore, observations of these groups are key to constrain the relative importance of these physical processes. However, current instruments are not sensitive enough to detect them easily and characterize their hot gas content.

Aims. In this work, we quantify the observing power of the Advanced Telescope for High ENergy Astrophysics (ATHENA), the future large X-ray observatory of the European Space Agency, for discovering and characterizing early galaxy groups at high redshifts. We also investigate how well ATHENA will constrain different feedback mechanisms.

Methods. We used the SImulation of X-ray TElescopes simulator to mimic ATHENA observations, and a custom-made wavelet-based algorithm to detect galaxy groups and clusters in the redshift range 0.5 ≤ z ≤ 4. We performed extensive X-ray spectral fitting in order to characterize their gas temperature and X-ray luminosity. In the simulations and their analysis, we took into account the main ATHENA instrumental features: background, vignetting, and point spread function degradation with off-axis angle, as well as all X-ray foreground and background components including a realistic AGN flux distribution. Different physically motivated thermo-dynamical states of galaxy groups were simulated and tested, including central AGN contamination, different scaling relation models (luminosity evolution), and distinct surface brightness profiles. Also, different ATHENA instrumental setups were tested, including both 15 and 19 mirror rows and the applied optical blocking filter.

Results. In the deep Wide Field Imager survey expected to be carried out during part of ATHENA’s first four years (the nominal mission lifetime) more than 10 000 galaxy groups and clusters at z ≥ 0.5 will be discovered. We find that ATHENA can detect ∼20 high-redshift galaxy groups with masses of M500 ≥ 5 × 1013 M⊙ and z ≥ 2, and almost half of them will have a gas temperature determined to a precision of ΔT/T ≤ 25%.

Conclusions. We demonstrate that high-redshift galaxy groups can be detected very efficiently as extended sources by ATHENA and that a key parameter determining the total number of such newly discovered sources is the area on the sky surveyed by ATHENA. We show that these observations have a very good potential to constrain the importance of different feedback processes in the early universe because of ATHENA’s ability not only to find the early groups but also to characterize their hot gas properties at the same time.
Alignment in the orientation of LOFAR radio sources
Authors: Osinga E. , Miley G. K. , van Weeren R. J. , Shimwell T. W. , Duncan K. J. , Hardcastle M. J. , Mechev A. P. , Röttgering H. J. A. , Tasse C. , Williams W. L.
Published: August 2020

Various studies have laid claim to finding an alignment of the polarization vectors or radio jets of active galactic nuclei over large distances, but these results have proven controversial and so far, there is no clear explanation for this observed alignment. To investigate this case further, we tested the hypothesis that the position angles of radio galaxies are randomly oriented in the sky by using data from the Low-Frequency Array (LOFAR) Two-metre Sky Survey (LoTSS). A sample of 7555 double-lobed radio galaxies was extracted from the list of 318 520 radio sources in the first data release of LoTSS at 150 MHz. We performed statistical tests for uniformity of the two-dimensional (2D) orientations for the complete 7555 source sample. We also tested the orientation uniformity in three dimensions (3D) for the 4212 source sub-sample with photometric or spectroscopic redshifts. Our sample shows a significant deviation from uniformity (p-value <  10−5) in the 2D analysis at angular scales of about four degrees, mainly caused by sources with the largest flux densities. No significant alignment was found in the 3D analysis. Although the 3D analysis has access to fewer sources and suffers from uncertainties in the photometric redshift, the lack of alignment in 3D points towards the cause of the observed effect being unknown systematics or biases that predominantly affect the brightest sources, although this has yet to be demonstrated irrefutably and should be the subject of subsequent studies.
The effects of granulation and supergranulation on Earth-mass planet detectability in the habitable zone around F6-K4 stars
Authors: Meunier N. , Lagrange A.-M.
Published: August 2020

Context. The detectability of exoplanets and the determination of their projected mass in radial velocity are affected by stellar magnetic activity and photospheric dynamics. Among those processes, the effect of granulation, and even more so of supergranulation, has been shown to be significant in the solar case. The impact for other spectral types has not yet been characterised.

Aims. Our study is aimed at quantifying the impact of these flows for other stars and estimating how such contributions affect their performance.

Methods. We analysed a broad array of extended synthetic time series that model these processes to characterise the impact of these flows on exoplanet detection for main sequence stars with spectral types from F6 to K4. We focussed on Earth-mass planets orbiting within the habitable zone around those stars. We estimated the expected detection rates and detection limits, tested the tools that are typically applied to such observations, and performed blind tests.

Results. We find that both granulation and supergranulation on these stars significantly affect planet mass characterisation in radial velocity when performing a follow-up of a transit detection: the uncertainties on these masses are sometimes below 20% for a 1 MEarth (for granulation alone or for low-mass stars), but they are much larger in other configurations (supergranulation, high-mass stars). For granulation and low levels of supergranulation, the detection rates are good for K and late G stars (if the number of points is large enough), but poor for more massive stars. The highest level of supergranulation leads to a very poor performance, even for K stars; this is both due to low detection rates and to high levels of false positives, even for a very dense temporal sampling over 10 yr. False positive levels estimated from standard false alarm probabilities sometimes significantly overestimate or underestimate the true level, depending on the number of points: it is, therefore, crucial to take this effect into account when analysing observations.

Conclusions. We conclude that granulation and supergranulation significantly affect the performance of exoplanet detectability. Future works will focus on improving the following three aspects: decreasing the number of false positives, increasing detection rates, and improving the false alarm probability estimations from observations.
Spectroscopic observations of the machine-learning selected anomaly catalogue from the AllWISE Sky Survey
Authors: Solarz A. , Thomas R. , Montenegro-Montes F. M. , Gromadzki M. , Donoso E. , Koprowski M. , Wyrzykowski L. , Diaz C. G. , Sani E. , Bilicki M.
Published: August 2020

We present the results of a programme to search and identify the nature of unusual sources within the All-sky Wide-field Infrared Survey Explorer (WISE) that is based on a machine-learning algorithm for anomaly detection, namely one-class support vector machines (OCSVM). Designed to detect sources deviating from a training set composed of known classes, this algorithm was used to create a model for the expected data based on WISE objects with spectroscopic identifications in the Sloan Digital Sky Survey. Subsequently, it marked as anomalous those sources whose WISE photometry was shown to be inconsistent with this model. We report the results from optical and near-infrared spectroscopy follow-up observations of a subset of 36 bright (gAB <  19.5) objects marked as “anomalous” by the OCSVM code to verify its performance. Among the observed objects, we identified three main types of sources: (i) low redshift (z ∼ 0.03 − 0.15) galaxies containing large amounts of hot dust (53%), including three Wolf-Rayet galaxies; (ii) broad-line quasi-stellar objects (QSOs) (33%) including low-ionisation broad absorption line (LoBAL) quasars and a rare QSO with strong and narrow ultraviolet iron emission; (iii) Galactic objects in dusty phases of their evolution (3%). The nature of four of these objects (11%) remains undetermined due to low signal-to-noise or featureless spectra. The current data show that the algorithm works well at detecting rare but not necessarily unknown objects among the brightest candidates. They mostly represent peculiar sub-types of otherwise well-known sources. To search for even more unusual sources, a more complete and balanced training set should be created after including these rare sub-species of otherwise abundant source classes, such as LoBALs. Such an iterative approach will ideally bring us closer to improving the strategy design for the detection of rarer sources contained within the vast data store of the AllWISE survey.
Mock catalogs for the extragalactic X-ray sky: Simulating AGN surveys with ATHENA and with the AXIS probe
Authors: Marchesi S. , Gilli R. , Lanzuisi G. , Dauser T. , Ettori S. , Vito F. , Cappelluti N. , Comastri A. , Mushotzky R. , Ptak A. , Norman C.
Published: August 2020

We present a series of new, publicly available mock catalogs of X-ray selected active galactic nuclei (AGNs), nonactive galaxies, and clusters of galaxies. These mocks are based on up-to-date observational results on the demographic of extragalactic X-ray sources and their extrapolations. They reach fluxes below 10−20 erg cm−2 s−1 in the 0.5–2 keV band, that is, more than an order of magnitude below the predicted limits of future deep fields, and they therefore represent an important tool for simulating extragalactic X-ray surveys with both current and future telescopes. We used our mocks to perform a set of end-to-end simulations of X-ray surveys with the forthcoming ATHENA mission and with the AXIS probe, a subarcsecond resolution X-ray mission concept proposed to the Astro 2020 Decadal Survey. We find that these proposed, next generation surveys may transform our knowledge of the deep X-ray Universe. As an example, in a total observing time of 15 Ms, AXIS would detect ∼225 000 AGNs and ∼50 000 nonactive galaxies, reaching a flux limit of f0.5−2 ∼ 5 × 10−19 erg cm−2 s−1 in the 0.5–2 keV band, with an improvement of over an order of magnitude with respect to surveys with current X-ray facilities. Consequently, 90% of these sources would be detected for the first time in the X-rays. Furthermore, we show that deep and wide X-ray surveys with instruments such as AXIS and ATHENA are expected to detect ∼20 000 z > 3 AGNs and ∼250 sources at redshift z > 6, thus opening a new window of knowledge on the evolution of AGNs over cosmic time and putting strong constraints on the predictions of theoretical models of black hole seed accretion in the early universe.
Quasars as standard candles
Authors: Lusso E. , Risaliti G. , Nardini E. , Bargiacchi G. , Benetti M. , Bisogni S. , Capozziello S. , Civano F. , Eggleston L. , Elvis M. , Fabbiano G. , Gilli R. , Marconi A. , Paolillo M. , Piedipalumbo E. , Salvestrini F. , Signorini M. , Vignali C.
Published: August 2020

We present a new catalogue of ∼2400 optically selected quasars with spectroscopic redshifts and X-ray observations from either Chandra or XMM–Newton. The sample can be used to investigate the non-linear relation between the ultraviolet (UV) and X-ray luminosity of quasars as well as to build a Hubble diagram up to a redshift of z ∼ 7.5. We selected sources that are neither reddened by dust in the optical and UV nor obscured by gas in the X-rays, and whose X-ray fluxes are free from flux-limit-related biases. After checking for any possible systematics, we confirm, in agreement with our previous works, that the X-ray to UV relation provides distance estimates matching those from supernovae up to z ∼ 1.5, and its slope shows no redshift evolution up to z ∼ 5. We provide a full description of the methodology for testing cosmological models, further supporting a trend whereby the Hubble diagram of quasars is well reproduced by the standard flat cold dark matter model up to z ∼ 1.5–2, but strong deviations emerge at higher redshifts. Since we have minimised all non-negligible systematic effects and proven the stability of the LX − LUV relation at high redshifts, we conclude that an evolution of the expansion rate of the Universe should be considered as a possible explanation for the observed deviation, rather than some systematic (redshift-dependent) effect associated with high-redshift quasars.
Social optima in leader-follower mean field linear quadratic control
Authors: Huang Jianhui , Wang Bing-Chang , Xie Tinghan
Published: August 2020

This paper investigates a linear quadratic mean field leader-follower team problem, where the model involves one leader and a large number of weakly-coupled interactive followers. The leader and the followers cooperate to optimize the social cost. Specifically, for any strategy provided first by the leader, the followers would like to choose a strategy to minimize social cost functional. Using variational analysis and person-by-person optimality, we construct two auxiliary control problems. By solving sequentially, the auxiliary control problems with consistent mean field approximations, we can obtain a set of decentralized social optimality strategy with help of a class of forward-backward consistency systems. The relevant Stackelberg equilibrium is further proved under some proper conditions.
A Zermelo navigation problem with a vortex singularity
Authors: Bonnard Bernard , Cots Olivier , Wembe Boris
Published: August 2020

Helhmoltz–Kirchhoff equations of motions of vortices of an incompressible fluid in the plane define a dynamics with singularities and this leads to a Zermelo navigation problem describing the ship travel in such a field where the control is the heading angle. Considering one vortex, we define a time minimization problem which can be analyzed with the technics of geometric optimal control combined with numerical simulations, the geometric frame being the extension of Randers metrics in the punctured plane, with rotational symmetry. Candidates as minimizers are parameterized thanks to the Pontryagin Maximum Principle as extremal solutions of a Hamiltonian vector field. We analyze the time minimal solution to transfer the ship between two points where during the transfer the ship can be either in a strong current region in the vicinity of the vortex or in a weak current region. The analysis is based on a micro-local classification of the extremals using mainly the integrability properties of the dynamics due to the rotational symmetry. The discussion is complex and related to the existence of an isolated extremal (Reeb) circle due to the vortex singularity. The explicit computation of cut points where the extremal curves cease to be optimal is given and the spheres are described in the case where at the initial point the current is weak.
Effect of MCl (M = Na, K) addition on microstructure and electrical conductivity of forsterite
Authors: El Asri Saloua , Ahamdane Hamid , Hajji Lahoucine , El Hadri Mohamed , El Idrissi Raghni Moulay Ahmed , Mansori Mohammed
Published: August 2020

Forsterite single phase powder Mg2SiO4 was synthesized by sol–gel method alongside with heat treatment, using two different cation alkaline salts MCl as mineralizers (M = Na, K) with various mass percentages (2.5, 5, 7.5, and 10 wt.%). In this work, we report on the effect of the cation type and the added amount of used mineralizer on microstructure and electrical conductivity of Mg2SiO4. The formation of forsterite started at 680–740  °C and at 630–700  °C with KCl and NaCl respectively, as shown by TG-DTA and confirmed by XRD. Furthermore, the Fourier transform infrared (FTIR) transmission spectra indicated bands corresponding to vibrations of forsterite structure. The morphology and elemental composition of sintered ceramics were examined by SEM-EDX analyses, while their densities, which were measured by Archimedes method, increased with addition of both alkaline salts. The electrical measurements were performed by Complex Impedance Spectroscopy. The results showed that electrical conductivity increased with the addition of both mineralizers, which was higher for samples prepared with NaCl than those prepared with KCl.
A polygonal discontinuous Galerkin method with minus one stabilization
Authors: Bertoluzza Silvia , Prada Daniele
Published: August 2020

We propose a discontinuous Galerkin method for the Poisson equation on polygonal tessellations in two dimensions, stabilized by penalizing, locally in each elementK, a residual term involving the fluxes, measured in the norm of the dual ofH1(K). The scalar product corresponding to such a norm is numerically realizedviathe introduction of a (minimal) auxiliary space inspired by the Virtual Element Method. Stability and optimal error estimates in the brokenH1norm are proven under a weak shape regularity assumption allowing the presence of very small edges. The results of numerical tests confirm the theoretical estimates.
Healthcare professionals’ knowledge of the doses and risks for radiological investigations performed during pregnancy
Authors: Ataalla N. , Yousef A.M.
Published: August 2020

Pregnant women should receive appropriate care during radiation examination which requires increased awareness of the effect of radiation and its associated risks. The aim of the study was to assess awareness of radiation risks on pregnant women during radiological examination among healthcare professionals and women who are pregnant or of childbearing age. A total of 225 individuals from different professional groups (nurses, medical radiographers, radiologists) and a total of 75 women who were pregnant or in childbearing age responded to a questionnaire-based cross-sectional study. The study was conducted in Riyadh and Al-Kharj hospitals in Saudi Arabia. Data were analyzed by T-test and ANOVAs-test to compare the level of knowledge among participants; the level of significance was set at p ≤ 0.05. The results showed that the healthcare workers who had attended training programs had an increased level of knowledge regarding radiation effects among pregnant women as compared to those who had not attended training programs (p < 0.05). The study showed a non-significant difference in awareness level for healthcare professionals regarding their job experience (p > 0.05). There was a lack of nurses’ awareness regarding X-ray or radiation dosage and its effect on pregnant women and fetuses. On-going training and education regarding radiation protection is recommended.
Adaptive projection methods for linear fractional programming
Authors: Bennani Ahlem , Benterki Djamel , Grar Hassina
Published: August 2020

In this paper, we are interested in solving a linear fractional program by two different approaches. The first one is based on interior point methods which makes it possible to solve an equivalent linear program to the linear fractional program. The second one allows us to solve a variational inequalities problem equivalent to the linear fractional program by an efficient projection method. Numerical tests were carried out by the two approaches and a comparative study was carried out. The numerical tests show clearly that interior point methods are more efficient than of projection one.
Wie lässt sich ein operationsbedingter Dekubitus verhindern?
Authors: Molitor Vincent
Published: August 2020

Die Dekubitusprophylaxe endet nicht mit dem Betreten des OP-Bereichs. Allerdings wird dieser Fakt sowohl von der Forschung als auch in manchen OP-Bereichen häufig noch vernachlässigt. Unser Autor hat konkrete Handlungsempfehlungen zusammengestellt, damit Sie Patienten vor dieser besonderen Art von Lagerungsschäden bestmöglich schützen können.
Truth versus ignorance in democratic politics: An existentialist perspective on the democratic promise of political freedom
Authors: König Pascal D.
Published: August 2020

Existentialist philosophy offers an understanding of how trying to eliminate ambiguities that inevitably mark the human condition only seemingly leads to freedom. This existentialist outlook can also serve to shed light on how democratic politics may similarly show tendencies which aim at overcoming immanent tensions. Such tendencies in democratic politics can be clarified using Sartre’s notion of ignorance – and truth as its counterpart. His concept of ignorance goes beyond merely facts or knowledge and refers to a mode of being. It expresses a subject’s desire to avoid, rather than confront, resistances stemming from the world. Based on a distinction of different forms in which this orientation can manifest itself, this article shows how democratic politics, too, can be threatened by ignorance as a way of doing politics. This ignorance comes in different guises which all express a desire to eliminate tensions that democratic politics cannot overcome without undermining itself.
Cell chirality in cardiovascular development and disease
Authors: Rahman Tasnif , Zhang Haokang , Fan Jie , Wan Leo Q.
Published: August 2020

The cardiovascular system demonstrates left-right (LR) asymmetry: most notably, the LR asymmetric looping of the bilaterally symmetric linear heart tube. Similarly, the orientation of the aortic arch is asymmetric as well. Perturbations to the asymmetry have been associated with several congenital heart malformations and vascular disorders. The source of the asymmetry, however, is not clear. Cell chirality, a recently discovered and intrinsic LR asymmetric cellular morphological property, has been implicated in the heart looping and vascular barrier function. In this paper, we summarize recent advances in the field of cell chirality and describe various approaches developed for studying cell chirality at multi- and single-cell levels. We also examine research progress in asymmetric cardiovascular development and associated malformations. Finally, we review evidence connecting cell chirality to cardiac looping and vascular permeability and provide thoughts on future research directions for cell chirality in the context of cardiovascular development and disease.
A mean-field approach to simulating anisotropic particles
Authors: Ramasubramani Vyas , Vo Thi , Anderson Joshua A. , Glotzer Sharon C.
Published: August 2020

We introduce a mean-field theoretical framework for generalizing isotropic pair potentials to anisotropic shapes. This method is suitable for generating pair potentials that can be used in both Monte Carlo and molecular dynamics simulations. We demonstrate the application of this theory by deriving a Lennard-Jones (LJ)-like potential for arbitrary geometries along with a Weeks–Chandler–Anderson-like repulsive variant, showing that the resulting potentials behave very similarly to standard LJ potentials while also providing a nearly conformal mapping of the underlying shape. We then describe an implementation of this potential in the simulation engine HOOMD-blue and discuss the challenges that must be overcome to achieve a sufficiently robust and performant implementation. The resulting potential can be applied to smooth geometries like ellipsoids and to convex polytopes. We contextualize these applications with reference to the existing methods for simulating such particles. The pair potential is validated using standard criteria, and its performance is compared to existing methods for comparable simulations. Finally, we show the results of self-assembly simulations, demonstrating that this method can be used to study the assembly of anisotropic particles into crystal structures.