bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reliability analysis incorporating exponentiated inverse Weibull distribution and inverse power law
Authors: Sindhu Tabassum Naz , Atangana Abdon 
Published: March 2021

AbstractIn reliability research, electronic devices are an important part of our lives and modelling their lives is the most difficult and fascinating area. To investigate the failure functioning of electronic equipments, reliability monitoring of systems is widely used. However, it is stated in the literature that one in five electronic system collapses are a consequence of degradation and saving energy and forecasting future losses, it is necessary to summarize the data through certain versatile models of probability . In current article, a model of reliability formed on inverse power law and generalized inverse Weibull model is suggested. This current distribution presents a clearer framework to modelling the efficiency and functionality lifespan of electronic equipments. In this article, an empirical analysis is discussed related to life cycle of a surface‐mounted electrolytic capacitor (SMEC). In addition, it has noticed that evaluation of suggested distribution varies from classical model of inverse Weibull and that influences average time to failure (ATTF) of the studied capacitor.
GC/MSn analysis of the crude reaction mixtures from Friedel–Crafts acylation: Unambiguous identification and differentiation of 3‐aroylbenzofurans from their 4‐ and 6‐regioisomers
Authors: Begala Michela , Mancinelli Michele , Quezada Elias , Delogu Giovanna Lucia 
Published: March 2021

Rationale3‐Aroylbenzofurans and their 2‐nitrophenyl derivatives constitute fundamental intermediates for the synthesis of target compounds with pharmaceutical properties. However, their preparation via the Friedel–Crafts acylation of 2‐phenylbenzofurans, using Lewis acid as catalyst, often leads to mixtures of regioisomeric aroylbenzofurans that can be challenging to distinguish, thus preventing the reaction characterization.MethodWe report a method for the unambiguous identification and differentiation of the desired 3‐benzoyl isomers from their 4‐ and 6‐regioisomers in a crude reaction mixture using gas chromatography coupled to multiple‐stage mass spectrometric (GC/MSn) analysis performed in collision‐induced dissociation (CID) mode.ResultsUpon electron ionization, each set of isomers displayed nearly identical mass spectra. MSn revealed fragmentation patterns that varied in the location of the benzoyl group on the benzofuran scaffold: CID experiments performed on the molecular ion allowed the distinction of the 3‐acyl isomers from the 4‐ and 6‐regioisomers; CID experiments on the [M − Ar]+ ion allowed the distinction of the 4‐benzoyl from the 6‐benzoyl regioisomer, when the nitro group is located on the 2‐phenyl ring. Moreover, the unusual loss of OH• radical allowed ascertaining the position of the nitro group in 3‐acyl regioisomers bearing the NO2 group. The origin of the diagnostic OH• loss was investigated through MSn experiments using 18O‐labelled 3‐benzoyl derivatives.ConclusionsThe method allows the rapid characterization of crude reaction mixtures of benzoylbenzofurans using solely GC/MSn analysis, simplifying the workflow of extensive isolation and purification for structure elucidation.
Chromosomal analyses of human giant diploid oocytes by next‐generation sequencing
Authors: Kawano Hiroomi , Yamashita Naoki , Ito Junya , Kashiwazaki Naomi 
Published: March 2021

AbstractPurposeAlthough giant oocytes (GOs) having about twice cytoplasmic volume compared with general oocytes in mammals including the human are rarely recovered, it is thought that GOs have potentially chromosomal abnormalities. The aim of the present study was to assess chromosome numbers in chromosome‐spindle complexes (CSCs) and polar bodies of human GOs by using micromanipulation for sampling and next‐generation sequencing (NGS) for analyses of the chromosome numbers.MethodsWhen recovered oocytes whose cytoplasm has lager than 140 µm or above, the oocytes were defined as GOs, and recovered GOs were vitrified. After warming, the CSCs, polar bodies, and enucleated cytoplasm were collected by micromanipulation from 3 GOs. The collected samples were analyzed by NGS.ResultsChromosomal aneuploidy in the GOs was confirmed in all the three GOs. Comparing the CSCs with the chromosomes from polar bodies, the deletion and overlapping chromosome numbers were complementary in each GO.ConclusionsThe authors could collect the CSCs and the polar bodies from human GOs by micromanipulation, and then could analyze the chromosome numbers of the GOs by NGS method. As our data suggest that human GOs have chromosomal abnormalities, GOs should be excluded from clinical purpose as gamete sources for embryo transfer in the human.
Adaptive tracking control of stochastic switched nonlinear systems with unknown dead‐zone output
Authors: Liu Yanli , Ma Hongjun 
Published: March 2021

AbstractIn this article, the problem of adaptive output feedback control is carried out for stochastic switched nonlinear systems with dead‐zone output and asymmetric tracking constraints. A type of smooth approximate model is proposed, which unfastens the nondifferentiable phenomena of dead‐zone output. The Nussbaum‐type function is utilized to develop the control design of the unknown dead‐zone output. Subsequently, an improved first‐order filter is cooperated into the barrier Lyapunov function analysis, which avoids the repeated derivative problem of virtual control inputs in the backstepping design procedure and completes the control design successfully. The proposed constructive control algorithm can achieve the control goal well. Finally, a numerical example with comparison results is given to further verify the validity of the new control tactic.
Potential of Magnetic Hyperthermia to Stimulate Localized Immune Activation
Authors: Carter Thomas J. , Agliardi Giulia , Lin Fang‐Yu , Ellis Matthew , Jones Clare , Robson Mathew , Richard‐Londt Angela , Southern Paul , Lythgoe Mark , Zaw Thin May , Ryzhov Vyacheslav , de Rosales Rafael T. M. , Gruettner Cordula , Abdollah Maha R. A. , Pedley R. Barbara , Pankhurst Quentin A. , Kalber Tammy L. , Brandner Sebastian , Quezada Sergio , Mulholland Paul , Shevtsov Maxim , Chester Kerry 
Published: March 2021

AbstractMagnetic hyperthermia (MH) harnesses the heat‐releasing properties of superparamagnetic iron oxide nanoparticles (SPIONs) and has potential to stimulate immune activation in the tumor microenvironment whilst sparing surrounding normal tissues. To assess feasibility of localized MH in vivo, SPIONs are injected intratumorally and their fate tracked by Zirconium‐89‐positron emission tomography, histological analysis, and electron microscopy. Experiments show that an average of 49% (21–87%, n = 9) of SPIONs are retained within the tumor or immediately surrounding tissue. In situ heating is subsequently generated by exposure to an externally applied alternating magnetic field and monitored by thermal imaging. Tissue response to hyperthermia, measured by immunohistochemical image analysis, reveals specific and localized heat‐shock protein expression following treatment. Tumor growth inhibition is also observed. To evaluate the potential effects of MH on the immune landscape, flow cytometry is used to characterize immune cells from excised tumors and draining lymph nodes. Results show an influx of activated cytotoxic T cells, alongside an increase in proliferating regulatory T cells, following treatment. Complementary changes are found in draining lymph nodes. In conclusion, results indicate that biologically reactive MH is achievable in vivo and can generate localized changes consistent with an anti‐tumor immune response.
Intralayered Ostwald Ripening‐Induced Self‐Catalyzed Growth of CNTs on MXene for Robust Lithium–Sulfur Batteries
Authors: Xu Mengyao , Liang Lin , Qi Jing , Wu Tianli , Zhou Dan , Xiao Zhubing 
Published: March 2021

AbstractThe distinguishable physicochemical properties of MXenes render them attractive in electrochemical energy storage. However, the strong tendency to self‐restack owing to the van der Waals interactions between the MXene layers incurs a massive decrease in surface area and blocking of ions transfer and electrolytes penetration. Here, in situ generated Ti3C2Tx MXene‐carbon nanotubes (Ti3C2Tx‐CNTs) hybrids are reported via low‐temperature self‐catalyzing growth of CNTs on Ti3C2Tx nanosheets without the addition of any catalyst precursors. With combined spectroscopic studies and theoretical calculation results, it is certified that the intralayered Ostwald ripening‐induced Ti3C2Tx nanomesh structure contributes to the uniform precipitation of ultrafine metal Ti catalysts on Ti3C2Tx, thus giving rise to the in situ CNTs formation on the surface of Ti3C2Tx with high integrity. Taking advantages of intimate electrolyte penetration, unobstructed 3D Li+/e transport, and rich electroactive sites, the Ti3C2Tx‐CNTs hybrids are confirmed to be ideal 3D scaffolds for accommodating sulfur and regulating the polysulfides conversion for high‐loaded lithium–sulfur batteries.
Multi‐Phase Heterostructure of CoNiP/CoxP for Enhanced Hydrogen Evolution Under Alkaline and Seawater Conditions by Promoting H2O Dissociation
Authors: Liu Dong , Ai Haoqiang , Chen Mingpeng , Zhou Pengfei , Li Bowen , Liu Di , Du Xinyu , Lo Kin Ho , Ng Kar‐Wei , Wang Shuang‐Peng , Chen Shi , Xing Guichuan , Hu Jinsong , Pan Hui 
Published: March 2021

AbstractHydrogen evolution reaction (HER) is a key step for electrochemical energy conversion and storage. Developing well defined nanostructures as noble‐metal‐free electrocatalysts for HER is promising for the application of hydrogen technology. Herein, it is reported that 3D porous hierarchical CoNiP/CoxP multi‐phase heterostructure on Ni foam via an electrodeposition method followed by phosphorization exhibits ultra‐highly catalytic activity for HER. The optimized CoNiP/CoxP multi‐phase heterostructure achieves an excellent HER performance with an ultralow overpotential of 36 mV at 10 mA cm−2, superior to commercial Pt/C. Importantly, the multi‐phase heterostructure shows exceptional stability as confirmed by the long‐term potential cycles (30,000 cycles) and extended electrocatalysis (up to 500 h) in alkaline solution and natural seawater. Experimental characterizations and DFT calculations demonstrate that the strong electronic interaction at the heterointerface of CoNiP/CoP is achieved via the electron transfer from CoNiP to the heterointerface, which directly promotes the dissociation of water at heterointerface and desorption of hydrogen on CoNiP. These findings may provide deep understanding on the HER mechanism of heterostructure electrocatalysts and guidance on the design of earth‐abundant, cost‐effective electrocatalysts with superior HER activity for practical applications.
Bottom‐Up Synthesis of Hexagonal Boron Nitride Nanoparticles with Intensity‐Stabilized Quantum Emitters
Authors: Chen Yongliang , Xu Xiaoxue , Li Chi , Bendavid Avi , Westerhausen Mika T. , Bradac Carlo , Toth Milos , Aharonovich Igor , Tran Toan Trong 
Published: March 2021

AbstractFluorescent nanoparticles are widely utilized in a large range of nanoscale imaging and sensing applications. While ultra‐small nanoparticles (size ≤10 nm) are highly desirable, at this size range, their photostability can be compromised due to effects such as intensity fluctuation and spectral diffusion caused by interaction with surface states. In this article, a facile, bottom‐up technique for the fabrication of sub‐10‐nm hexagonal boron nitride (hBN) nanoparticles hosting photostable bright emitters via a catalyst‐free hydrothermal reaction between boric acid and melamine is demonstrated. A simple stabilization protocol that significantly reduces intensity fluctuation by ≈85% and narrows the emission linewidth by ≈14% by employing a common sol–gel silica coating process is also implemented. This study advances a promising strategy for the scalable, bottom‐up synthesis of high‐quality quantum emitters in hBN nanoparticles.
Effect of age and waste crumb rubber aggregate proportions on flexural characteristics of self‐compacting rubberized concrete
Authors: Wanasinghe Dimuthu , Aslani Farhad , Dai Kunyou 
Published: March 2021

AbstractGeneration of waste has been a significant problem in recent decades in many engineering fields. Self‐compacting rubberized concrete (SCRC) is a new type of SCC, which replaces part of natural aggregates by rubber aggregates in SCC to increase the application range of waste tyre rubber. This study investigates the effect of age and crumb rubber aggregate ratio on fresh and mechanical performance. Eight different SCRC mixtures using 2–5 mm rubber aggregates to replace 10%, 20%, 30%, and 40% natural aggregates by volume respectively, and 5–10 mm rubber aggregates to replace 10%, 20%, 30%, and 40% natural aggregates by volume respectively, are tested after 7, 28, 56, and 91 days for their mechanical properties. Results show that both the compressive and the tensile strength increase with the aging time, both of these properties drop with the amount and size of the crumb rubber content. Similar to compressive and tensile properties, flexural toughness and the modulus of rupture showed increased with the aging time. Small addition of crumb rubber has shown improvements in both rupture and fracture toughness properties, which diminishes when the crumb rubber content becomes significantly large.
Performance of self‐compacting rubberized concrete against carbonation and chloride penetration
Authors: Mallek Jihen , Daoud Atef , Omikrine‐Metalssi Othman , Loulizi Amara 
Published: March 2021

AbstractThis study assessed the performance of self‐compacting rubberized concrete against carbonation and chloride penetration. In addition to fresh‐state and compressive strength tests, durability of the studied mixes was evaluated by measuring carbonation and chloride penetration depths, total porosity, and pores'size distribution. It was found that an increase in rubber content leads to a decrease in compressive strength. However, stadequate strength for structural applications was achieved up to an incorporation of 15% rubber by volume. As for durability, the presence of rubber was found to enhance performance against carbonation, but to worsen the resistance to chloride ion penetration.
How Glycine Betaine Modifies Lipid Membrane Interactions
Authors: Shakhman Yuri , Harries Daniel 
Published: March 2021

AbstractUbiquitous in the cellular milieu, small organic compounds termed osmolytes help to regulate the response to environmental stress. Elasmobranchii, such as sharks, accumulate high concentrations of several osmolytes, most notably urea, trimethylamine N‐oxide (TMAO), and glycine betaine (GB). These three compounds are used to osmoregulate the organism's body fluids, so that they counteract seawater salinity, as well as the destabilizing effects of hydrostatic pressure on cells and their molecular components. Herein we focus on glycine betaine and show how it modifies interactions between lipid membranes. We find that the addition of GB exerts an apparent attractive force that draws neighboring membranes toward one another. We show that, at the molecular level, this apparent attraction between membranes in the presence of GB is due to its preferential exclusion from the space between adjacent membranes, which thereby exerts an osmotic pressure that brings membranes closer together. This action is similar to the one we have previously reported for TMAO. However, we find that the net effect of GB is significantly smaller than that of TMAO, because GB concomitantly significantly weakens van der Waals attractions between membranes by changing the dielectric properties of the intervening solution. Finally, we show how GB acts in combination with urea. At high total concentrations and over a wide range of GB‐to‐urea ratios, urea counteracts the effect of GB, so that the equilibrium separation between membranes is close to their values in pure water. This finding supports the prevailing idea that mixtures of several osmolytes can achieve minimal net impact on biomacromolecular stability while also counteracting osmotic stress.
Transition‐Metal‐Free C−S, C−Se, and C−Te Bond Formation from Organoboron Compounds
Authors: Sacramento Manoela , Costa Gabriel P. , Barcellos Angelita M. , Perin Gelson , Lenardão Eder J. , Alves Diego 
Published: March 2021

AbstractThe present review describes the successful application of organoboron compounds in transition‐metal‐free C−S, C−Se, and C−Te bond formations. We presented studies regarding these C‐Chalcogen bond formations using organoboron reagents, such as boronic acids, boronic esters, borate anions, and several sources of chalcogen atoms/moieties. Moreover, a broad range of transition‐metal‐free approaches to synthesize sulfides, selenides, and tellurides were described using conventional heating methods, which are sometimes green since they use green solvents, safe reagents, among others. Furthermore, protocols using alternative energy sources, including ultrasound, microwave irradiation, photocatalysis, and electrolytic processes, were also shown to be suitable. These protocols were applied to prepare a broad scope of functionalized chalcogenides with high molecular diversity. These studies and their proposed mechanisms were also reported herein in addition to the reuse of reaction promoters.
A Parisian Vision of the Chemistry of Hypercoordinated Silicon Derivatives
Authors: Lemière Gilles , Millanvois Alexandre , Ollivier Cyril , Fensterbank Louis 
Published: March 2021

AbstractLess than ten years of acquaintance with hypercoordinated silicon derivatives in our lab is described in this account. Martin's spirosilane derivatives open new opportunities as ligands and as agents for the activation of small molecules and bis‐catecholato silicates have proven to be exquisite radical precursors in photoredox conditions for broad synthetic applications.
Observations on spindly leg syndrome in a captive population ofAndinobates geminisae
Authors: Higgins Kathleen , Guerrel Jorge , Lassiter Elliot , Mooers Arne , Palen Wendy J. , Ibáñez Roberto 
Published: March 2021

AbstractAmphibian health problems of unknown cause limit the success of the growing number of captive breeding programs. Spindly leg syndrome (SLS) is one such disease, where affected individuals with underdeveloped limbs often require euthanization. We experimentally evaluated husbandry‐related factors of SLS in a captive population of the critically endangered frog,Andinobates geminisae. SLS has been linked to tadpole nutrition, vitamin B deficiency, water filtration methods, and water quality, but few of these have been experimentally tested. We tested the effects of water filtration method and vitamin supplementation (2017) and the effects of tadpole husbandry protocol intensity (2018) on time to metamorphosis and the occurrence of SLS. We found that vitamin supplementation and reconstituted reverse osmosis filtration of tadpole rearing water significantly reduced SLS prevalence and that reduced tadpole husbandry delayed time to metamorphosis. A fortuitous accident in 2018 resulted in a decrease in the phosphate content of rearing water, which afforded us an additional opportunity to assess the influence of phosphate on calcium sequestration. We found that tadpoles that had more time to sequester calcium for ossification during development had decreased the prevalence of SLS. Taken together, our results suggest that the qualities of the water used to rear tadpoles plays an important role in the development of SLS. Specifically, filtration method, vitamin supplementation, and calcium availability of tadpole rearing water may play important roles. Focused experiments are still needed, but our findings provide important information for amphibian captive rearing programs affected by high SLS prevalence.
Higher spins from exotic dualisations
Authors: Boulanger Nicolas , Lekeu Victor 
Published: March 2021

Abstract
At the free level, a given massless field can be described by an infinite number of different potentials related to each other by dualities. In terms of Young tableaux, dualities replace any number of columns of height hi by columns of height D − 2 − hi, where D is the spacetime dimension: in particular, applying this operation to empty columns gives rise to potentials containing an arbitrary number of groups of D − 2 extra antisymmetric indices. Using the method of parent actions, action principles including these potentials, but also extra fields, can be derived from the usual ones. In this paper, we revisit this off-shell duality and clarify the counting of degrees of freedom and the role of the extra fields. Among others, we consider the examples of the double dual graviton in D = 5 and two cases, one topological and one dynamical, of exotic dualities leading to spin three fields in D = 3.
Gravitational vector Dark Matter
Authors: Gross Christian , Karamitsos Sotirios , Landini Giacomo , Strumia Alessandro 
Published: March 2021

Abstract
A new dark sector consisting of a pure non-abelian gauge theory has no renormalizable interaction with SM particles, and can thereby realise gravitational Dark Matter (DM). Gauge interactions confine at a scale ΛDM giving bound states with typical lifetimes $$ \tau \sim {M}_{\mathrm{P}1}^4/{\Lambda}_{\mathrm{DM}}^5 $$
τ
∼

M

P
1

4

/

Λ
DM
5

that can be DM candidates if ΛDM is below 100 TeV. Furthermore, accidental symmetries of group-theoretical nature produce special gravitationally stable bound states. In the presence of generic Planck-suppressed operators such states become long-lived: SU(N) gauge theories contain bound states with $$ \tau \sim {M}_{\mathrm{P}1}^8/{\Lambda}_{\mathrm{DM}}^9 $$
τ
∼

M

P
1

8

/

Λ
DM
9

; even longer lifetimes τ = (MPl/ΛDM)2N−4/ΛDM arise from SO(N) theories with N ≥ 8, and possibly from F4 or E8. We compute their relic abundance generated by gravitational freeze-in and by inflationary fluctuations, finding that they can be viable DM candidates for ΛDM ≳ 1010 GeV.
Continuous LTI Input–Output Stable Systems on $${L^{p}(\mathbb {R})}$$ and $${\mathscr {D'}_{L^{p}}(\mathbb {R})}$$ Associated with Differential Equations: Existence, Invertibility Conditions and Inversion
Authors: Ciampa M. 
Published: March 2021

AbstractA usual problem in analog signal processing is to ascertain the existence of a continuous single-input single-output linear time-invariant input–output stable system associated with a linear differential equation, i.e., of a continuous system such that, for every input signal in a given space of signals, yields an output, in the same space, which verifies the equation with known term the input, and to ascertain the existence of its inverse system. In this paper, we consider, as space of signals, the usual Banach space of $${L^{p}}$$

L
p

functions, or the space of distributions spanned by $${L^{p}}$$

L
p

functions and by their distributional derivatives, of any order (input spaces which include signals with not necessarily left-bounded support), we give a systematic theoretical analysis of the existence, uniqueness and invertibility of continuous linear time-invariant input–output stable systems (both causal and non-causal ones) associated with the differential equation and, in case of invertibility, we characterize the continuous inverse system. We also give necessary and sufficient conditions for causality. As an application, we consider the problem of finding a suitable almost inverse of a causal continuous linear time-invariant input–output stable non-invertible system, defined on the space of finite-energy functions, associated with a simple differential equation.