bluuebunny/crossref_metadata_2025_split huggingface dataset:
Socioeconomic status and school absenteeism: A systematic review and narrative synthesis
Authors: Sosu Edward M. , Dare Shadrach , Goodfellow Claire , Klein Markus 
Published: August 2021

AbstractSchool absenteeism is detrimental to life course outcomes and is known to be socioeconomically stratified. However, the link between socioeconomic status (SES) and school absence is complex given the multidimensional nature of both family SES (e.g., income, education, occupational status) and absenteeism (e.g., truancy, sickness, suspension). Despite the vast literature on socioeconomic inequalities in school attendance, no systematic review on SES and school absenteeism exists. This study systematically reviewed and provides a narrative synthesis of journal articles (n = 55) published between 1998 to 2019 on the association between SES dimensions and forms of absenteeism. The majority of studies from high‐income contexts found an association between SES and absenteeism in the expected direction, albeit on average with small effect sizes. Studies largely confirmed these findings among populations at risk of school absence and those from low‐ and middle‐income countries. There was greater evidence for an association between absenteeism and SES measured at the family than the school level. Studies using SES measures of financial resources (e.g., free or reduced‐price lunch) provided more evidence for this association than studies measuring sociocultural resources (e.g., parental education). We found limited evidence that socioeconomic gaps in absenteeism vary by the reasons for absence. Research on the mediating pathways between SES and absenteeism is sparse. A key implication is that attempts to address inequalities in educational outcomes must include tackling SES gaps in school attendance.
Context and implicationsRationale for this studyOur narrative review synthesised the literature on socioeconomic status (SES) and school absenteeism.Why the new findings matterInequalities in school absenteeism may partly account for socioeconomic disparities in children’s academic achievement. We found that lower SES is associated with higher levels of absenteeism in most of the studies we reviewed, including among disadvantaged groups.Implications for policy‐makers and practitionersGiven robust evidence that school absences are detrimental to children’s academic achievement, policy‐makers and practitioners need to place an explicit focus on addressing socioeconomic disparities in school attendance in order to close SES achievement gaps. This will be particularly important in tackling the consequences of Covid‐19 related school closures around the world. An intersectional approach that addresses multiple disadvantages should be adopted to tackle inequalities in school attendance. Researchers should address several gaps, such as directly comparing SES effects across different reasons for absenteeism and examining the mechanisms by which SES leads to absenteeism.
MT‐filters‐based adaptive quantized dynamic surface control of stochastic nonstrict‐feedback nonlinear systems including input unmodeled dynamics
Authors: Zhang Tianping , Chen Penghao 
Published: August 2021

AbstractIn this article, the issue of stochastic adaptive dynamic surface control (DSC) is discussed for stochastic nonstrict‐feedback constrained nonlinear systems with input quantization and input unmodeled dynamics. Linearly parametrized neural networks are used to estimate unknown continuous functions. With the help of MT‐filters, the unmeasurable system states are observed. An auxiliary signal constructed by the property of unmodeled dynamics is utilized to deal with the dynamic uncertain terms. Input‐quantized actuator is considered to possess quantization and unmodeled dynamics. Using the hyperbolic tangent function as invertible change, the output constrained stochastic nonstrict‐feedback system is transformed into a novel stochastic nonstrict‐feedback system without restrictions. Based on quantized DSC technology and the property of Gaussian function, adaptive neural control is developed for the transformed stochastic nonstrict‐feedback system. The output abides by stochastic constraints in probability. By the Lyapunov synthesis approach, all signals in the whole system are proved to be semi‐global uniform ultimate bounded in probability. The restriction condition is not triggered. The obtained theoretical findings are verified by two numerical examples.
Transcriptional Profiling of Circulating Mononuclear Cells from Patients with Chronic Obstructive Pulmonary Disease receiving Mesenchymal Stromal Cell Infusions
Authors: Armitage Jesse D. , Tan Dino B.A. , Sturm Marian , Moodley Yuben P. 
Published: August 2021

AbstractChronic obstructive pulmonary disease (COPD) is an inflammatory airways disease with limited therapeutic options. We have previously shown that mesenchymal stromal cell (MSC) infusions are well tolerated in patients with COPD and reduce circulatory biomarkers associated with systemic inflammation and oxidative stress. This study aimed to delineate the underlying mechanisms further by characterizing the transcriptional networks in these patients and to explore the role of MSC-derived paracrine factors in regulating these pathways. Allogeneic, bone marrow-derived MSCs were systemically administered into patients with stable COPD (n = 9). Gene expression profiles from peripheral blood mononuclear cells (PBMCs) were analyzed across the first week after infusion. Paracrine mechanisms associated with these transcriptional changes were explored further by culturing patient PBMCs with MSC-conditioned medium (MSC-CM) or post-MSC infusion (PI) plasma to measure the regulatory effects of soluble factors that may be derived from MSCs. MSC-CM and PI-plasma were characterized further to identify potential immunoregulatory candidates. MSC infusion elicited a strong but transient transcriptional response in patient PBMCs that was sustained up to 7 days. MSC infusion strongly downregulated transcriptional pathways related to interleukin (IL)-8 and IL-1β, which were also significantly inhibited in vitro following co-culture of PBMCs with MSC-CM and PI-plasma. MSC-derived soluble tumor necrosis factor receptor-1, transforming growth factor-β1, and extracellular vesicle-associated microRNAs were identified as potential mechanisms promoting these changes, but depletion of these individual candidates revealed inconsistent results. MSC-derived paracrine factors modulate important inflammatory pathways that are relevant to COPD pathogenesis. These data strengthen the hypothesis that therapies using MSCs and their secreted products may be beneficial to patients with COPD.
Supramolecular Tropism Driven Aggregation of Nanoparticles In Situ for Tumor‐Specific Bioimaging and Photothermal Therapy
Authors: Cheng Qian , Yue Ludan , Li Junyan , Gao Cheng , Ding Yuanfu , Sun Chen , Xu Mengze , Yuan Zhen , Wang Ruibing 
Published: August 2021

AbstractInorganic nanomedicine has attracted increasing attentions in biomedical sciences due to their excellent biocompatibility and tunable, versatile functionality. However, the relatively poor accumulation and retention of these nanomedicines in targeted tissues have often hindered their clinical translation. Herein, highly efficient, targeted delivery, and in situ aggregation of ferrocene (Fc)‐capped Au nanoparticles (NPs) are reported to cucurbit[7]uril (CB[7])‐capped Fe3O4 NPs (as an artificial target) that are magnetically deposited into the tumor, driven by strong, multipoint CB[7]‐Fc host–guest interactions (here defined as “supramolecular tropism” for the first time), leading to high tumor accumulation and retention of these NPs. The in vitro and in vivo studies demonstrate the precisely controlled, specific accumulation, and retention of Au NPs in the tumor cells and tissue via supramolecular tropism and in situ aggregation, which afford locally enhanced CT imaging of cancer and enable tumor‐specific photothermal therapy attributed to the plasmonic coupling effects between adjacent Au NPs within the supramolecular aggregations. This work provides a novel concept of supramolecular tropism, which may drive targeted delivery and enable specific accumulation, retention, and activation of nanomedicine for improved bioimaging and therapy of cancer.
Raman Spectroscopic Fingerprints of Atomically Precise Ligand Protected Noble Metal Clusters: Au38(PET)24 and Au38−xAgx(PET)24
Authors: Krishnadas Kumaranchira Ramankutty , Baghdasaryan Ani , Kazan Rania , Banach Ewa , Teyssier Jeremie , Nicu Valentin Paul , Buergi Thomas 
Published: August 2021

AbstractDistinct Raman spectroscopic signatures of the metal core of atomically precise, ligand‐protected noble metal nanoclusters are reported using Au38(PET)24 and Au38−xAgx(PET)24 (PET = 2‐phenylethanethiolate, ‐SC2H4C6H5) as model systems. The fingerprint Raman features (occurring <200 cm−1) of these clusters arise due to the vibrations involving metal atoms of their Au23 or Au23−xAgx cores. A distinct core breathing vibrational mode of the Au23 core has been observed at 90 cm−1. Whereas the breathing mode shifts to higher frequencies with increasing Ag content of the cluster, the vibrational signatures due to the outer metal‐ligand staple motifs (between 200 and 500 cm−1) do not shift significantly. DFT calculations furthermore reveal weak Raman bands at higher frequencies compared to the breathing mode, which are associated mostly with the rattling of two central gold atoms of the bi‐icosahedral Au23 core. These vibrations are also observed in the experimental spectrum. The study indicates that low‐frequency Raman spectra are a characteristic fingerprint of atomically precise clusters, just as electronic absorption spectroscopy, in contrast to the spectrum associated with the ligand shell, which is observed at higher frequencies.
Insights into the Interfacial Lewis Acid–Base Pairs in CeO2‐Loaded CoS2 Electrocatalysts for Alkaline Hydrogen Evolution
Authors: Li Jiayuan , Xia Zhaoming , Xue Qingyu , Zhang Mingkai , Zhang Sai , Xiao Hai , Ma Yuanyuan , Qu Yongquan 
Published: August 2021

AbstractDespite the known efficacy of CeO2 as a promoter in alkaline hydrogen evolution reaction (HER), the underlying mechanism of this effect remains unclear. CoS2, a pyrite‐type alkaline HER electrocatalyst, suffers from sluggish HER kinetics and severe catalyst leaching due to its weak water dissociation kinetics and oxygen‐related corrosion. Herein, it is demonstrated that the interfacial Lewis acid–base Ce∙∙∙S pairs in CeO2‐loaded CoS2 effectively improve the catalytic activity and durability. In CeO2‐loaded CoS2 nanowire array electrodes, these interfacial Lewis acid–base Ce∙∙∙S pairs with unique electronic and structural configurations efficiently activate water adsorptive dissociation and kinetically accelerate hydrogen evolution, delivering a low overpotential of 36 mV at 10 mA cm−2 in alkaline media. Such Ce∙∙∙S pairs also weaken O2 adsorption on CoS2, leading to undecayed activity over 1000 h. These findings are expected to provide guidance for the design of CeO2‐based electrocatalysts as well as other hybrid electrocatalysts for water splitting.
Application of intrinsically conducting polymers in flexible electronics
Authors: Ouyang Jianyong 
Published: August 2021

AbstractIntrinsically conducting polymers (ICPs), such as polyacetylene, polyaniline, polypyrrole, polythiophene, and poly(3,4‐ethylenedioxythiophene) (PEDOT), can have important application in flexible electronics owing to their unique merits including high conductivity, high mechanical flexibility, low cost, and good biocompatibility. The requirements for their application in flexible electronics include high conductivity and appropriate mechanical properties. The conductivity of some ICPs can be enhanced through a postpolymerization treatment, the so‐called “secondary doping.” A conducting polymer film with high conductivity can be used as flexible electrode and even as flexible transparent electrode of optoelectronic devices. The application of ICPs as stretchable electrode requires high mechanical stretchability. The mechanical stretchability of ICPs can be improved through blending with a soft polymer or plasticization. Because of their good biocompatibility, ICPs can be modified as dry electrode for biopotential monitoring and neural interface. In addition, ICPs can be used as the active material of strain sensors for healthcare monitoring, and they can be adopted to monitor food processing, such as the fermentation, steaming, storage, and refreshing of starch‐based food because of the resistance variation caused by the food volume change. All these applications of ICPs are covered in this review article.
Thallium toxicosis in a Brittany Spaniel
Authors: Nunes Rodrigues Tania C. , Mortier Femke , de Baets Justine , Vandenabeele Sophie I. 
Published: August 2021

AbstractThallium was commonly used as a rodenticide in the past. It acts as a cellular poison and interferes with the functioning of various enzymes. This report describes a fatal case of thallium intoxication in a dog with gastrointestinal and neurological signs as well as dermatological lesions. Cutaneous histopathology and serum spectrometry confirmed thallium toxicosis.
Flat self-dual gravity
Authors: Krasnov Kirill , Skvortsov Evgeny 
Published: August 2021

Abstract
We construct a new covariant action for “flat” self-dual gravity in four space-time dimensions. The action has just one term, but when expanded around an appropriate background gives rise to a kinetic term and a cubic interaction. Upon imposing the light-cone gauge, the action reproduces the expected chiral interaction of Siegel. The new action is in many ways analogous to the known covariant action for self-dual Yang-Mills theory. There is also a sense in which the new self-dual gravity action exhibits the double copy of self-dual Yang-Mills structure.
An Exponential Separation Between MA and AM Proofs of Proximity
Authors: Gur Tom , Liu Yang P. , Rothblum Ron D. 
Published: August 2021

AbstractInteractive proofs of proximity allow a sublinear-time verifier to
check that a given input is close to the language, using a
small amount of communication with a powerful (but untrusted)
prover. In this work, we consider two natural
minimally interactive variants of such
proofs systems, in which the prover only sends a single message,
referred to as the proof.
The first variant, known as -proofs of
Proximity (), is fully non-interactive, meaning that the
proof is a function of the input only. The second variant,
known as -proofs of Proximity (), allows the proof
to additionally depend on the verifier's (entire) random string. The
complexity of both s and s is the total number of bits
that the verifier observes—namely, the sum of the proof length
and query complexity.
Our main result is an exponential separation between the power of
s and s. Specifically, we exhibit an explicit and
natural property $$\Pi$$
Π
that admits an with complexity
$$O(\log n)$$

O
(
log
n
)

, whereas any for $$\Pi$$
Π
has complexity
$$\tilde{\Omega}(n^{1/4})$$

Ω
~

(

n

1
/
4

)

, where n denotes the length of the input
in bits. Our lower bound also yields an alternate proof,
which is more general and arguably much simpler, for a
recent result of Fischer et al. (ITCS, 2014). Also, Aaronson (Quantum Information & Computation 2012) has shown
a $$\Omega(n^{1/6})$$

Ω
(

n

1
/
6

)

lower bound for the same property $$\Pi$$
Π
.Lastly, we also consider the notion of oblivious proofs of proximity, in which
the verifier's queries are oblivious to the proof.
In this setting, we show
that s can only be quadratically stronger than s. As an
application of this result, we show an exponential separation
between the power of public and private coin for oblivious
interactive proofs of proximity.
A new strategy for the computer-assisted development of reversed-phase liquid chromatography separation methods of unknown sample mixtures
Authors: Cela R. , Triñanes S. , Cobas C. 
Published: August 2021

AbstractA new strategy for the computer-assisted methods development in the reversed-phase liquid chromatographic separations of unknown sample mixtures has been developed using the latent spectral information in chromatogram raw data files of appropriately designed experiments, rather than resorting to elemental information functions (e.g., the number of peaks in chromatograms or similar criteria). The strategy developed allows unification of the approach for samples of both known and unknown composition and, thus, provide a general strategy for computer-aided tools in the chromatography laboratory. The operation principle of this strategy departs from extracting the spectra of components in the mixture chromatograms by resorting to multivariate curve resolution-alternating least squares (MCR-ALS). This technique allows the estimation of the true spectra for the individual components except when they have identical spectra or are fully overlapped. Thus, a convenient experimental design will try to perform separations of the sample mixture having at least partial resolution of components in some runs. This will allow estimating the spectra of components and, then, assign these components to the peaks in each run chromatogram. In this way, a retention model can be built for each component so computerized optimization process can be developed to provide the chromatographer with the best possible separation programs. Following this approach, strategies for sample mixtures of known and unknown composition are only different in the need of an initial spectrum discovery process for unknown mixtures and therefore a real general approach for the computer-assisted LC methods development is now available for the first time.
Spectrahedral representation of polar orbitopes
Authors: Kobert Tim , Scheiderer Claus 
Published: August 2021

AbstractLetKbe a compact Lie group andVa finite-dimensional representation ofK. The orbitope of a vector$$x\in V$$x∈Vis the convex hull$${\mathscr {O}}_x$$Oxof the orbitKxinV. We show that ifVis polar then$${\mathscr {O}}_x$$Oxis a spectrahedron, and we produce an explicit linear matrix inequality representation. We also consider the coorbitope$${\mathscr {O}}_x^o$$Oxo, which is the convex set polar to$${\mathscr {O}}_x$$Ox. We prove that$${\mathscr {O}}_x^o$$Oxois the convex hull of finitely manyK-orbits, and we identify the cases in which$${\mathscr {O}}_x^o$$Oxois itself an orbitope. In these cases one has$${\mathscr {O}}_x^o=c\cdot {\mathscr {O}}_x$$Oxo=c·Oxwith$$c>0$$c>0. Moreover we show that ifxhas “rational coefficients” then$${\mathscr {O}}_x^o$$Oxois again a spectrahedron. This provides many new families of doubly spectrahedral orbitopes. All polar orbitopes that are derived from classical semisimple Lie algebras can be described in terms of conditions on singular values and Ky Fan matrix norms.
Synthesis, characterization, and evaluation of antibacterial activity of transition metal oxyde nanoparticles
Authors: Morais Dielly Oliveira , Pancotti Alexandre , de Souza Guilherme Sastre , Saivish Marielena Vogel , Braoios Alexandre , Moreli Marcos Lázaro , Souza Mauro Vinícius de B. , da Costa Vivaldo G. , Wang Jiale 
Published: August 2021

AbstractNanoparticles (NPs) have a wide range of applications in various areas. For health application, cytotoxicity tests are used to ensure its efficiency and safety. In this paper, ZnFe2O4, CoFe2O4, Zn0.5Co0.5Fe2O4 NPs were synthesized, characterized and their antibacterial properties were evaluated. The Sol-Gel method was used to synthesize the NPs. Their electronic and crystallographic structures were characterized by Fourier Transform Infrared Spectroscopy Analysis (FTIR), X-ray fluorescence (XRF), X-Ray Diffraction (XRD), and Transmission Electron Microscopy (TEM). To perform the antibacterial evaluation, ferrites were dispersed through nanoemulsion to prevent the crystals from accumulating together. Then the evaluation was performed through microdilution in a 96-well plate and diffusion in agar disc in contact with 3 different strains of Staphylococcus aureus and Escherichia coli. It demonstrated that the Sol-Gel method was efficient to synthesize NPs with suitable sizes for health application. All synthesized NPs showed the inhibition of bacterias with different concentrations used.
Impact of COVID-19 on ischemic stroke care in Hungary
Authors: Böjti Péter Pál , Szilágyi Géza , Dobi Balázs , Stang Rita , Szikora István , Kis Balázs , Kornfeld Ákos , Óváry Csaba , Erőss Lóránd , Banczerowski Péter , Kuczyński Wojciech , Bereczki Dániel 
Published: August 2021

AbstractData about the coronavirus disease 2019 (COVID-19) pandemic’s collateral damage on ischemic stroke (IS) care during the second epidemic wave in Central Europe are limited. We sought to evaluate the impact of the COVID-19 outbreak on Hungarian IS care during the two epidemic waves. This retrospective observational study was based on a nationwide reimbursement database that encompasses all IS admissions and all reperfusion interventions, i.e., intravenous thrombolysis (IVT) and endovascular therapy (EVT) from 2 January 2017 to 31 December 2020 in Hungary. COVID-19 pandemic’s effect on the number of IS admissions and reperfusion interventions were analyzed using different statistics: means, medians, trends, relative rates, and linear relationships. The mean and median values of IS admissions and reperfusion interventions decreased only in some measure during the COVID-periods. However, trend analysis demonstrated a significant decline from the trends. The decline’s dynamic and amplitude have differed for each variable. In contrast to IVT, the number of IS admissions and EVTs negatively correlated with the epidemic waves’ amplitude. Besides, the decrease in the number of IS admissions was more pronounced than the decrease in the number of reperfusion interventions. Our study demonstrated a significant disruption in IS care during the COVID-19 epidemic in Hungary, in which multiple different factors might play a role. The disproportionate reduction of IS admission numbers could partially be explained by the effect of health emergency operative measures and changes in patients’ social behavior. Further studies are needed to evaluate the causes of our observations.
Optimization of a clamping concept based on machine learning
Authors: Feng Qi , Maier Walther , Stehle Thomas , Möhring Hans-Christian 
Published: August 2021

AbstractFixtures are an important element of the manufacturing system, as they ensure productive and accurate machining of differently shaped workpieces. Regarding the fixture design or the layout of fixture elements, a high static and dynamic stiffness of fixtures is therefore required to ensure the defined position and orientation of workpieces under process loads, e.g. cutting forces. Nowadays, with the increase in computing performance and the development of new algorithms, machine learning (ML) offers an appropriate possibility to use regression methods for creating realistic, rapid and reliable equivalent ML models instead of simulations based on the finite element method (FEM). This research work introduces a novel method that allows an optimization of clamping concepts and fixture design by means of ML, in order to reduce manufacturing errors and to obtain an increased stiffness of fixtures and machining accuracy. This paper describes the preparation of a dataset for training ML models, the systematic selection of the most promising regression algorithm based on relevant criteria, the implementation of the chosen algorithm Extreme Gradient Boosting (XGBoost) and other comparable algorithms, the analysis of their regression results, and the validation of the optimization for a selected clamping concept.