bluuebunny/crossref_metadata_2025_split huggingface dataset:
A simple proof of the Kochen‐Specker theorem on the problem of hidden variables
Authors: Straumann N. 
Published: June 2022

AbstractIn this contribution I present a simple derivation of an old result of Kochen and Specker, which is apparently unrelated to the famous work of Bell on hidden variables, but is presumably equally important. Kochen and Specker showed in 1967 that quantum mechanics cannot be embedded into a classical stochastic theory, provided the quantum theoretical probability distributions are reproduced and one additional highly desirable property is satisfied. This showed in a striking manner what were the difficulties in implementing the Einstein programme of a ‘complete’ version of quantum mechanics.
Grassmann, geometric algebra and cosmology
Authors: Lasenby A.N. 
Published: June 2022

AbstractStarting with Grassmann's work, a short review is given of the development of ‘Geometric Algebra’, and the reasons why it is a useful system for describing much of physics. Applications are then discussed in cosmology, including a novel boundary condition for the universe, and efficient ways to encode Bianchi cosmology. Predictions for the Cosmic Microwave Background in such models, and in another area owing much to Grassmann (String Theory), are also discussed.
Deriving spacetime from first principles
Authors: Ambjørn J. , Jurkiewicz J. , Loll R. 
Published: June 2022

AbstractCausal Dynamical Triangulation is a back‐to‐basics approach to nonperturbative, background‐independent quantum gravity, which relies on few ingredients and initial assumptions, has few free parameters and – crucially – is amenable to numerical simulations. After putting the approach in context, we briefly describe its set‐up and highlight some of its major, and sometimes unexpected findings. Prominent among them is the dynamical generation of a classical de Sitter universe from Planckian quantum fluctuations.
What is the dark energy paradigm?
Authors: Polarski D. 
Published: June 2022

AbstractThe present accelerated expansion of the universe is a major challenge for cosmology. Dark Energy models aim to explain this unconventional expansion. We have at the present time a large variety of models which are conceptually very different. We review here some of them, especially those based on a modification of the laws of gravity. Future high precision observations probing both the background and the perturbations will significantly reduce the class of viable models.
Non‐standard loop quantum cosmology
Authors: Piechocki W. 
Published: June 2022

AbstractWe present results concerning the nature of the cosmological big bounce (BB) transition within the loop geometry underlying loop quantum cosmology (LQC). Our canonical quantization method is an alternative to the standard LQC. An evolution parameter we use has clear interpretation both at classical and quantum levels. The physical volume operator has discrete spectrum which is bounded from below. The minimum gap in the spectrum defines a quantum of the volume. The spectra of operators are parametrized by a free parameter to be determined.
Dark energy from temporal and spatial singularities of pressure
Authors: Da̧browski M.P. 
Published: June 2022

AbstractI describe an opportunity to mimic dark energy leading to a current acceleration of the universe by the application of the pressure singularities surrounding an observer. Two essentially different models are investigated. In the first one, the acceleration is due to an approach to a pressure singularity which appears on a constant time hypersurface. In the second one, the acceleration is due to the existence of the pressure singularities in some regions of space. Both models are tested positively against observations.
Dark energy from quantum fluctuations
Authors: Broda B. , Szanecki M. 
Published: June 2022

AbstractWe have derived the quantum vacuum pressure pvac as a primary entity, removing a trivial and a gauge terms from the cosmological constant‐like part (the zeroth term) of the effective action for a matter field. The quantum vacuum energy density

appears a secondary entity, but both are of expected order. Moreover pvac and

are dynamical, and therefore they can be used in the Einstein equations. In particular, they could dynamically support the holographic dark energy model as well as the “thermodynamic” one.
Constraining unified dark matter models with weak lensing
Authors: Camera S. 
Published: June 2022

AbstractUnified Dark Matter (UDM) models provide an intriguing alternative to Dark Matter (DM) and Dark Energy (DE) through only one exotic component, i.e. a classical scalar field φ(t, x). Thanks to a non–canonical kinetic term, this scalar field can mimic both the behaviour of the matter–dominated era at earlier times, as DM do, and the outcoming late–time acceleration, as a cosmological constant DE. Thus, it has been shown that these models can reproduce the same expansion history of the ΛCDM concordance model. In this work I review the first prediction of a physical observable, the power spectrum of the weak lensing cosmic convergence (shear). I present the weak lensing signal as predicted by the standard ΛCDM model and by a family of viable UDM models parameterized by the late–time sound speed c∞ of the scalar field.last–scattering surface and a series of background galaxies peaked at different redshifts and spread over different redshifts as described by a functional form of their distribution of sources.
On the fate of vacuum bubbles on matter backgrounds
Authors: Rakić A. , Simon D. , Adamek J. , Niemeyer J. 
Published: June 2022

AbstractIn this letter we discuss cosmological first order phase transitions with de Sitter bubbles nucleating on (inhomogeneous) matter backgrounds. The de Sitter bubble can be a toy model for an inflationary phase of universes like our own. Using the thin wall approximation and the Israel junction method we trace the classical evolution of the formed bubbles within a compound model. We first address homogeneous ambient space (FRW model) and already find that bubbles nucleated in a dust dominated background cannot expand. For an inhomogeneous dust background (LTB model) we describe cases with at least initially expanding bubbles. Yet, an ensuing passage of the bubble wall through ambient curvature inhomogeneities remains unnoticed for observers inside the bubble. Notable effects also for interior observers are found in the case of a rapid background phase transition in a FRW model.
Noether symmetric minisuperspace model of f(R) cosmology
Authors: Vakili B. 
Published: June 2022

AbstractWe study the metric f(R) cosmology using Noether symmetry approach by utilizing the behavior of the corresponding Lagrangian under infinitesimal generators of the desired symmetry. The existence of Noether symmetry of the cosmological f(R) minisuperspace helps us to find out the form of f(R) function for which such symmetry exist. It is shown that the resulting form for f(R) yields a power law expansion for the cosmic scale factor. We also show that in the corresponding Noether symmetric quantum model, the solutions to the Wheeler‐DeWitt equation can be expressed as a superposition of states of the form eiS. It is shown that in terms of such wavefunctions the classical trajectories can be recovered.
Gezielte Dehydratisierung als Synthesewerkzeug zur Herstellung eines neuen Na4SnS4‐Polymorphs: Kristallstruktur, Na+‐Leitfähigkeit und Einfluss der Sb‐Substitution
Authors: Hartmann Felix , Benkada Assma , Indris Sylvio , Poschmann Michael , Lühmann Henning , Duchstein Patrick , Zahn Dirk , Bensch Wolfgang 
Published: June 2022

AbstractWir präsentieren eine sehr bequeme Synthese und die Charakterisierung des neuen Thiostannats Na4SnS4 (
) durch gezielte thermische Zersetzung von Na4SnS4⋅14 H2O. Die Verbindung stellt ein neues, kinetisch stabilisiertes Polymorph von Na4SnS4 dar, welches sich beim Erhitzen in die thermodynamisch stabile Form (
) umwandelt. Durch thermische Ko‐Zersetzung von Mischungen mit Na3SbS4⋅9 H2O werden feste Lösungen Na4−xSn1−xSbxS4 (x=0.01, 0.10) erhalten, die isostrukturell zum neuen Polymorph (x=0) kristallisieren. Ergebnisse aus Röntgenbeugung, 119Sn NMR‐, 23Na NMR‐ und 119Sn‐Mößbauerspektroskopie zeigen, dass der Einbau von Sb5+ die Bindungen und die lokalen Strukturen erheblich beeinflusst. Durch Impedanzspektroskopie wird eine enorme Verbesserung der Ionenleitfähigkeit mit zunehmendem Sb‐Gehalt für die feste Lösung ermittelt (σ25 °C=2×10−3, 2×10−2 und 0.1 mS cm−2 1 für x=0, 0.01 und 0.10), welche um mehrere Größenordnungen höher sind als bei dem bekannten Na4SnS4‐Polymorph.
A Novel AgI‐DNA Rod Comprising a One‐Dimensional Array of 11 Silver Ions within a Double Helical Structure
Authors: Atsugi Takahiro , Ono Akira , Tasaka Miho , Eguchi Natsumi , Fujiwara Shoji , Kondo Jiro 
Published: June 2022

AbstractDNA/RNA duplexes containing metal‐ion‐mediated base pairs (metallo‐base pairs) have potential applications in developing nucleic acid‐based nanodevices and genetic code expansion. Many metallo‐base pairs are formed within duplexes stabilized by Watson–Crick base pairs. Recently, the crystal structure of an AgI‐DNA nanowire with an uninterrupted one‐dimensional silver array was determined. Here, we present a new DNA helical wire, the “AgI‐DNA rod”, containing an uninterrupted array of 11 AgI ions. The AgI‐DNA rod consisted of only C‐AgI‐C, G‐AgI‐G, G‐AgI‐5‐bromouracil (BrU), and BrU‐AgI‐BrU metallo base pairs, with no Watson–Crick pairs. The AgI‐DNA rods were connected by non‐canonical G–G pairs in crystals. Notably, data from our absorbance, circular dichroism, nuclear magnetic resonance, and mass spectrometry analyses suggested that the AgI‐DNA rods formed in solution, as well as within crystals.
A Small Molecular Symmetric All‐Organic Lithium‐Ion Battery
Authors: Li Zengyu , Jia Qingqing , Chen Yuan , Fan Kun , Zhang Chenyang , Zhang Guoqun , Xu Ming , Mao Minglei , Ma Jing , Hu Wenping , Wang Chengliang 
Published: June 2022

AbstractThe structural designability of organic electrode materials makes them attractive for symmetric all‐organic batteries (SAOBs) by virtue of different plateaus. However, quite a few works have reported all‐organic batteries and it is still challenging to develop a high‐performance organic material for SAOBs. Herein, a small molecule, 2,3,7,8‐tetraaminophenazine‐1,4,6,9‐tetraone (TAPT), is reported for SAOBs. The rich C=O and C=N groups ensure the high capacity at both plateaus for C=O/C−O and C=N/C−N redox reactions, which are hence utilized as cathodic and anodic active centers respectively. Moreover, the presence of C=O, C=N and NH2 groups resulted in plentiful strong intermolecular interactions, leading to layered structures, insolubility and high stability. The rich functional groups also facilitated the chelation of N and O with Li cations and hence benefited the storage of Li cations. The electrochemical performances of TAPT‐based SAOBs outperformed all of the previously reported SAOBs.
Directed Dehydration as Synthetic Tool for Generation of a New Na4SnS4 Polymorph: Crystal Structure, Na+ Conductivity, and Influence of Sb‐Substitution
Authors: Hartmann Felix , Benkada Assma , Indris Sylvio , Poschmann Michael , Lühmann Henning , Duchstein Patrick , Zahn Dirk , Bensch Wolfgang 
Published: June 2022

AbstractWe present the convenient synthesis and characterization of the new ternary thiostannate Na4SnS4 (space group
) by directed removal of crystal water molecules from Na4SnS4⋅14 H2O. The compound represents a new kinetically stable polymorph of Na4SnS4, which is transformed into the known, thermodynamically stable form (space group
) at elevated temperatures. Thermal co‐decomposition of mixtures with Na3SbS4⋅9 H2O generates solid solution products Na4−xSn1−xSbxS4 (x=0.01, 0.10) isostructural to the new polymorph (x=0). Incorporation of Sb5+ affects the bonding and local structural situation noticeably evidenced by X‐ray diffraction, 119Sn and 23Na NMR, and 119Sn Mössbauer spectroscopy. Electrochemical impedance spectroscopy demonstrates an enormous improvement of the ionic conductivity with increasing Sb content for the solid solution (σ25°C=2×10−3, 2×10−2, and 0.1 mS cm−1 for x=0, 0.01, and 0.10), being several orders of magnitude higher than for the known Na4SnS4 polymorph.
CuI/AgI‐containing coordination compounds as advanced catalysts for selective oxidation of styrene to benzaldehyde
Authors: Zhao Zi‐Qiu , Geng Ying , Song Jiang‐Feng , Cui Xiao‐Bing 
Published: June 2022

AbstractFour coordination compounds, [Cu(Hmthd)2Cl]n (1), [Cu3(mthd)2Br]n (2), [Ag(mthd)]n (3), and [Ag2(mthd)I]n (4) (Hmthd = 2‐mercapto‐5‐methyl‐1,3,4‐thiadiazole), were synthesized and characterized by inductively coupled plasma (ICP) elemental analyses, powder X‐ray diffraction (PXRD), and Fourier transform infrared (FT‐IR) spectroscopies. These resulting coordination compounds can act as efficient catalysts for the oxidation of olefins with tert‐butyl hydroperoxide (TBHP) as oxidant. Wherein, compound 2 performed extremely enhanced catalytic activity for oxidation of styrene at 80°C. Moreover, the addition of an appropriate amount of acid can promote the protonation of ligands and activate the two Ag‐containing catalysts to improve their catalytic efficiencies. Experimental results indicate that catalyst 2 has a low activation energy and excellent recycle catalytic property. Radical trap experiments were performed to verify that free radicals participate in the oxidation of styrene.
Hydrothermal aging of fire‐protective fabrics
Authors: Hoque Md. Saiful , Saha Ankit , Chung Hyun‐Joong , Dolez Patricia I. 
Published: June 2022

AbstractFire‐protective fabrics made from high‐performance fibers are available to provide protection from various hazardous conditions such as extreme heat and flame. However, these fabrics are often exposed to other deteriorating conditions, including moisture. It is a concern for user's safety as some high‐performance fibers are sensitive to hydrolysis. This study exposed eight fire‐protective fabrics corresponding to typical blends used in firefighter protective suit outer shells to accelerated hydrothermal aging. They were immersed in water at different temperatures between 60 and 95°C for up to 1200 h. After exposure to hydrothermal aging, some fabrics exhibited a significant loss in tensile strength without any morphological changes. Based on results from energy‐dispersive X‐ray spectroscopy and pH measurements of the aging water, the larger loss in strength experienced by the para‐aramid/PBI fiber‐based fabrics can be related to the high amount of sulfur measured in the PBI fibers, contributing to an acceleration of the para‐aramid fiber's hydrolysis in acidic conditions. Hydrothermal aging also appears to affect the water‐repellent finish of some fabrics. The study provides an insight into the effect of a generally ignored hazard, that is, moisture, on the long‐term performance of fire‐protective fabrics.
Insights into modulating the monastrol scaffold: Development of new pyrimidinones as Eg5 inhibitors with anticancer activity
Authors: Thabit Mohamed G. , Mostafa Amany S. , Selim Khalid B. , Elsayed Magda A. A. , Nasr Magda N. A. 
Published: June 2022

AbstractBased on modulation of the monastrol scaffold, two series of pyrimidinone derivatives, 3a–e and 5a–k, were designed, synthesized, and investigated for their in vitro anticancer activity. Compound 5j exhibited the most potent cytotoxic activity against four cancer cell lines, including HCT‐116, HeLa, HEPG‐2, and MCF‐7, with IC50 values of 3.75–5.13 µM, while proving to be safe in the normal human cell line WI‐38, with a selectivity index value of 13.7 on HCT‐116 cells. Compounds 3d, 3e, and 5h–j were further assessed for their Eg5 inhibitory activity, where 3d and 5h–j showed high Eg5 inhibition with IC50 values of 28.48, 24.22, 18.90, and 12.89 µM, respectively, when compared to monastrol (IC50 = 14.89 µM). Cell cycle distribution of HCT‐116 cells monitored with compound 5j illustrated that the cell cycle was arrested at the G2/M phase, with considerable apoptotic effect. A molecular docking study was performed to investigate the mode of action of the synthesized anticancer agents as Eg5 inhibitors.
Characterization of caspase‐2 inhibitors based on specific sites of caspase‐2‐mediated proteolysis
Authors: Bresinsky Merlin , Strasser Jessica M. , Hubmann Alexander , Vallaster Bernadette , McCue William M. , Fuller Jessica , Singh Gurpreet , Nelson Kathryn M. , Cuellar Matthew E. , Finzel Barry C. , Ashe Karen H. , Walters Michael A. , Pockes Steffen 
Published: June 2022

AbstractSince the discovery of the caspase‐2 (Casp2)‐mediated ∆tau314 cleavage product and its associated impact on tauopathies such as Alzheimer's disease, the design of selective Casp2 inhibitors has become a focus in medicinal chemistry research. In the search for new lead structures with respect to Casp2 selectivity and drug‐likeness, we have taken an approach by looking more closely at the specific sites of Casp2‐mediated proteolysis. Using seven selected protein cleavage sequences, we synthesized a peptide series of 53 novel molecules and studied them using in vitro pharmacology, molecular modeling, and crystallography. Regarding Casp2 selectivity, AcITV(Dab)D‐CHO (23) and AcITV(Dap)D‐CHO (26) demonstrated the best selectivity (1–6‐fold), although these trends were only moderate. However, some analogous tetrapeptides, most notably AcDKVD‐CHO (45), showed significantly increased Casp3 selectivities (>100‐fold). Tetra‐ and tripeptides display decreased or no Casp2 affinity, supporting the assumption that a motif of five amino acids is required for efficient Casp2 inhibition. Overall, the results provide a reasonable basis for the development of both selective Casp2 and Casp3 inhibitors.
A note on the existence and optimal control for mixed Volterra–Fredholm‐type integrodifferential dispersion system of third order
Authors: Patel Rohit , Vijayakumar V. , Nieto Juan J. , Jadon Shimpi Singh , Shukla Anurag 
Published: June 2022

AbstractThe optimal control problem consists of a performance index subject to a set of differential equations that describes the path of the control and state variables. The main aim of this article is to prove the existence and uniqueness of a mild solution, optimal control, and time‐optimal control of a mixed Volterra–Fredholm‐type third‐order dispersion system. By applying the strongly continuous semigroup theory and the Banach fixed‐point theorem, we prove the existence and uniqueness of the considered system. The optimal control results are proved by using Mazur's lemma, Gronwall's inequality, and the minimizing sequence technique. The discussion on the time‐optimal control of the third‐order dispersion system is also presented.
A mechanistic review on immunomodulatory effects of selective type two cannabinoid receptor β‐caryophyllene
Authors: Baradaran Rahimi Vafa , Askari Vahid Reza 
Published: June 2022

Abstractβ‐Caryophyllene (BCP) is a plant‐derived compound and occurs naturally in various foods and spices, including cinnamon, citrus, fruits, clove, curry, and pepper. BCP showed different pharmacological effects, such as antioxidant and antimicrobial properties. This article tried to gather updated knowledge of the anti‐inflammatory, antioxidant, and immunomodulatory effects of BCP and searched using various databases and appropriate keywords until April 2022. Several studies showed that the anti‐inflammatory effects of BCP are mainly provided through cannabinoid receptor 2 (CB2) receptor activation and the peroxisome proliferator‐activated receptor (PPAR) γ pathway. It has also been demonstrated that BCP suppresses both protein and mRNA expression levels of interleukin (IL)‐6 and reduces relevant proinflammatory cytokines but increases the anti‐inflammatory cytokine IL‐13. Previous results indicated that the antioxidant effects of β‐caryophyllene were suggested through different pathways, including activation of nuclear factor erythroid 2‐related factor‐2 (Nrf2)/heme oxygenase‐1 (HO‐1)/antioxidant axis and inhibition of the HMG‐CoA reductase activity, and oxidative stress biomarkers levels. Furthermore, various results showed immunomodulatory effects of BCP through inhibiting microglial cells, CD4+ and CD8+ T lymphocytes, modulated Th1/Treg immune balance through the activation of the CB2 receptor, and reducing mitogen‐activated protein kinases (p38MAPK) and NF‐kB activation and increased ionized calcium‐binding adaptor molecule‐1 (Iba‐1) and IL‐1β.
Transcriptomic analysis reveals mode of action of butyric acid supplementation in an intensified CHO cell fed‐batch process
Authors: Schulze Markus , Kumar Yadhu , Rattay Merle , Niemann Julia , Wijffels Rene H. , Martens Dirk E. 
Published: June 2022

AbstractProcess intensification is increasingly used in the mammalian biomanufacturing industry. The key driver of this trend is the need for more efficient and flexible production strategies to cope with the increased demand for biotherapeutics predicted in the next years. Therefore, such intensified production strategies should be designed, established, and characterized. We established a CHO cell process consisting of an intensified fed‐batch (iFB), which is inoculated by an N‐1 perfusion process that reaches high cell concentrations (100 × 106 c ml−1). We investigated the impact of butyric acid (BA) supplementation in this iFB process. Most prominently, higher cellular productivities of more than 33% were achieved, thus 3.5 g L−1 of immunoglobulin G (IgG) was produced in 6.5 days. Impacts on critical product quality attributes were small. To understand the biological mechanisms of BA in the iFB process, we performed a detailed transcriptomic analysis. Affected gene sets reflected concurrent inhibition of cell proliferation and impact on histone modification. These translate into subsequently enhanced mechanisms of protein biosynthesis: enriched regulation of transcription, messenger RNA processing and transport, ribosomal translation, and cellular trafficking of IgG intermediates. Furthermore, we identified mutual tackling points for optimization by gene engineering. The presented strategy can contribute to meet future requirements in the continuously demanding field of biotherapeutics production.
The effect of the informal sector on sustainable development: Evidence from developing countries
Authors: Sultana Nahid , Rahman Mohammad Mafizur , Khanam Rasheda 
Published: June 2022

AbstractThis study aims to explore the impact of the informal sector on the sustainability of development. A large panel data set of 50 developing countries that spans over 2010–2019 has been utilized to this end while the informal sector is evaluated in terms of working poverty. Selecting indicators from three dimensions of sustainability, that is, economy, society, and environment, this study has constructed three indices and combines those to construct a symptomatic composite index of sustainability. Both the short run and long run panel data models have been applied to empirically investigate the impact of informal economic activities on the sustainability of development. Economic growth, national expenditure, and economic freedom of countries are used as control variables in the models and the estimated outcomes are found to be robust in empirical investigations. The outcomes of the study imply that the informal sector plays a detrimental role in the sustainable development of developing countries while economic growth and economic freedom contribute positively. Therefore, the prescribed strategy is to reduce informality from business and other economic activities that limit the scope of the economies and to understand the domain through which interventions can be made to move to a more formal economy. Integration of informal business and SMEs into the formal sector and firm‐level awareness building in Corporate Social Responsibility can also be suggested to find a path towards sustainable development in addition to increased economic growth and enhanced economic opportunities of the developing countries.