bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cryptocurrency price prediction using traditional statistical and machine‐learning techniques: A survey
Authors: Khedr Ahmed M. , Arif Ifra , P V Pravija Raj , El‐Bannany Magdi , Alhashmi Saadat M. , Sreedharan Meenu 
Published: March 2021

AbstractCryptocurrencies are decentralized electronic counterparts of government‐issued money. The first and best‐known cryptocurrency example is bitcoin. Cryptocurrencies are used to make transactions anonymously and securely over the internet. The decentralization behavior of a cryptocurrency has radically reduced central control over them, thereby influencing international trade and relations. Wide fluctuations in cryptocurrency prices motivate the urgent requirement for an accurate model to predict its price. Cryptocurrency price prediction is one of the trending areas among researchers. Research work in this field uses traditional statistical and machine‐learning techniques, such as Bayesian regression, logistic regression, linear regression, support vector machine, artificial neural network, deep learning, and reinforcement learning. No seasonal effects exist in cryptocurrency, making it hard to predict using a statistical approach. Traditional statistical methods, although simple to implement and interpret, require a lot of statistical assumptions that could be unrealistic, leaving machine learning as the best technology in this field, being capable of predicting price based on experience. This article provides a comprehensive summary of the previous studies in the field of cryptocurrency price prediction from 2010 to 2020. The discussion presented in this article will help researchers to fill the gap in existing studies and gain more future insight.
Betulin ameliorates 7,12‐dimethylbenz(a)anthracene‐induced rat mammary cancer by modulating MAPK and AhR/Nrf‐2 signaling pathway
Authors: Zhang Jinku , Zhou Bingjuan , Sun Jirui , Chen Hong , Yang Zhao 
Published: March 2021

AbstractThe aim of the present study is to explore the preventive efficacy of betulin (BE) in 7,12‐dimethylbenz(a)anthracene (DMBA)‐administered mammary cancer by modulating Ahr/Nrf2 signaling in experimental models. The mammary cancer was stimulated by the addition of DMBA (25 mg/kg/b.Wt) mixed in 1 ml of vehicle solution (sunflower oil and saline 1:1) through subcutaneous injection. The DMBA‐exposed mammary tumor models showed low bodyweight, elevated quantities of lipid peroxidation molecules (TBARS and LOOH), and low enzymatic (GPx, SOD, and CAT), and nonenzymatic (GSH, vitamin C, and vitamin E) antioxidant activities in plasma and mammary tissues. Moreover, histopathological studies confirmed that invasive ductal carcinoma was observed in DMBA‐induced mammary tissue of the experimental model. Dietary oral supplementation of BE prevents the loss of bodyweight, overproduces lipid peroxidation, and restores the antioxidant activities in DMBA‐exposed experimental animals. The nuclear factor erythroid 2‐related factor 2 (Nrf2) is a crucial antioxidant protein that involves preventing numerous cancers. Therefore, Nrf2‐associated signaling concern is a significant target for preventing mammary cancer. This study observed an increased expression of MAPKs, Keap1, ARNT, AhR, and CYP1A1, whereas decreased expression of HO‐1 and Nrf2 in DMBA‐induced cancer‐bearing experimental animals. The oral supplementation of BE effectively modulates the expression of MAPKs, AhR/Nrf2‐associated protein expressions in DMBA‐exposed experimental animals. This current study concluded that BE is a strong antioxidant, which triggers the MAPKs‐mediated oxidative stress and inhibits proliferative markers by restoring the activity of Nrf2 signaling.
Non long‐range corrected density functionals incorrectly describe the intensity of the CH stretching band in polycyclic aromatic hydrocarbons
Authors: Geindre Hugo , Allouche Abdul‐Rahman , Peláez Daniel 
Published: March 2021

AbstractWe present a comprehensive study of the most relevant numerical aspects influencing frequencies and intensities in the infrared spectrum of isolated polycyclic aromatic hydrocarbons (PAHs) regarding the overestimate of the IR CH‐stretching bands. We use naphthalene as benchmark and show the validity of our results to different members of the PAH family. Our analysis relies on widely employed density functional theory methods and second‐order vibrational perturbational theory for the computation of vibrational eigenstates. We have focused on the elucidation of the origin of the systematic overestimate of the intensities in the CH‐stretching region. To rule out nonfundamental numerical errors, we have initially considered the influence of the electronic basis set and various other parameters on the different stages of the vibrational analysis. In a second stage, we have benchmarked the results of different density functional theory functionals with respect to the aforementioned overestimate taken as the ratio between the most prominent features of the spectrum, the CH‐bending and the CH‐stretching bands. Our results unambiguously indicate that the long‐range correction plays a major role in this spurious numerical issue. More specifically, this phenomenon is due to an incorrect description of the charge distribution (and hence dipole) within the symmetrically relevant CH bonds. Long‐range correction specifically remedies this issue. It improves the description of the intensities in the stretching region while at the same time it does not perturb significantly the rest of the spectrum. With respect to the frequencies, we have observed an overall improvement when compared to noncorrected functionals.
Doubling the optical efficiency of color‐converted micro‐light‐emitting diode displays with a patterned cholesteric liquid crystal polymer film
Authors: Hsiang En‐Lin , Li Yannanqi , He Ziqian , Zhan Tao , Zhang Caicai , Lan Yi‐Fen , Dong Yajie , Wu Shin‐Tson 
Published: March 2021

AbstractWe propose a patterned cholesteric liquid crystal (CLC) polymer film as a self‐assembled Bragg reflector to enhance the performance of a color‐converted micro‐light‐emitting diode (LED) display system. In the display system, we firstly optimize the device structure of blue LED chip to maintain a high light extraction efficiency and low optical crosstalk. Next, we fabricate several patterned CLC films with feature sizes ranging from 10 to 80 μm. By integrating the patterned CLC film into a color‐conversion micro‐LED display, the optical efficiency is doubled while keeping a color gamut of about 90% Rec. 2020. Finally, we carry out a proof‐of‐concept experiment to validate the functionality of such a patterned CLC film.
Development and validation of a gas chromatography method coupled with flame ionization detector for quantitative analysis of fragrance allergens in aromas for e‐cigarettes
Authors: Pawelec Aleksandra , Wielgomas Bartosz 
Published: March 2021

AbstractAromas can give smell and/or flavor to a variety of products in the cosmetic and food industry. They are also used as e‐cigarette additives. Some of those substances are recognized as fragrance allergens and can cause allergic reactions so there is a need to control their use. Gas chromatography is the method of choice for analyzing fragrance allergens because of their low boiling points. This study aimed to develop and validate a robust and simple method for the analysis of fragrance allergens in aromas for e‐cigarettes. A method using gas chromatography coupled with a flame ionization detector was developed for 25 fragrance allergens. Optimized parameters were sample diluent, internal standard, and carrier gas. The output method was the one previously developed and optimized. The linearity of the method was >0.994 over the range of 0.5–40 μg/mL. Accuracy and precision were within the acceptance range. Limits of detection and quantification were determined, and calibration curves were plotted. The method was applied to three real samples of aromas. Thirteen fragrance allergens were detected. Concentrations varied in the range of dozens to thousands of μg/mL showed that concentrations of fragrances in aromas for e‐cigarettes can be high and varies among products.
4‐Phenylbutyric acid, a potent endoplasmic reticulum stress inhibitor, attenuates the severity of collagen‐induced arthritis in mice via inhibition of proliferation and inflammatory responses of synovial fibroblasts
Authors: Choi Yunjung , Lee Eun‐Gyeong , Jeong Ji‐Hyeon , Yoo Wan‐Hee 
Published: March 2021

Abstract4‐Phenylbutyric acid (4‐PBA) exerts potent pharmacological effects, including anti‐inflammatory properties, via inhibition of endoplasmic reticulum (ER) stress. However, it is not known whether 4‐PBA attenuates the severity of rheumatoid arthritis. The present study aimed to determine whether the inhibition of ER stress by 4‐PBA ameliorated experimentally induced arthritis. The proliferation of synovial fibroblasts (SFs) and expression of matrix metalloproteinases (MMPs) were evaluated in the presence of interleukin (IL)‐1β with or without 4‐PBA. The effect of 4‐PBA on the phosphorylation of Mitogen‐activated protein kinase (MAPK) and the activation of Nuclear factor‐κB (NF‐κB) in IL‐1β‐stimulated SFs was assessed. In an in vivo study, the effects of 4‐PBA were investigated using DBA/1 mice with collagen‐induced arthritis (CIA). Clinical, histological, and serological assessments of CIA treated with 4‐PBA were performed to determine the therapeutic effect of 4‐PBA. In vitro, 4‐PBA inhibited the proliferation and expression of IL‐1β‐stimulated SFs and MMP‐1 and MMP‐3 through the suppression of both the phosphorylation of MAPKs and NF‐κB in IL‐1β‐stimulated SFs. The 4‐PBA treatment markedly attenuated the severity of arthritis in CIA mice. The 4‐PBA treatment ameliorated joint swelling and the degree of bone erosion and destruction and decreased the level of inflammatory cytokines and MMP‐3 and Cox‐2. Furthermore, remarkable improvements in histopathological findings occurred in 4‐PBA‐treated mice. These findings suggested that 4‐PBA could attenuate the severity of arthritis in CIA mice by partially blocking the phosphorylation of MAPKs and the activation of NF‐κB in SFs. Thus, through the inhibition of ER stress, 4‐PBA may be a potent agent for the treatment of RA.
Dynamic Heterogeneity of Filler‐Associated Interphases in Polymer Nanocomposites
Authors: Schneider Horst , Roos Matthias , Golitsyn Yury , Steiner Kerstin , Saalwächter Kay 
Published: March 2021

AbstractDynamically inhomogeneous polymer systems exhibit interphases with mobility gradients. These are believed to play key roles in the material's performance. A prominent example is particle‐filled rubber, a special case of a crosslinked polymer nanocomposite, where favorable rubber‐filler interactions may give rise to a nanoscale immobilized layer around the filler, including regions of intermediate mobility. Such intermediate domains may either form a separate shell‐like layer or be a manifestation of dynamic heterogeneities, in which case the intermediately mobile material would be dispersed in the form of nanometer‐sized subdomains. In this contribution, bidirectional proton NMR spin diffusion (SD) experiments applied to silica‐filled acrylate rubber are combined with numerical simulations to provide microscopic insights into this question. While model calculations for different scenarios fit the given data similarly well for longer SD mixing time, the short‐time data do support the presence of dynamic heterogeneities.
Impact of multimodal strategies to reduce multidrug‐resistant organisms in surgical intensive care units: Knowledge, practices and transmission: A quasi‐experimental study
Authors: Kasatpibal Nongyao , Chittawatanarat Kaweesak , Nunngam Nantana , Kampeerapanya Daranee , Duangsoy Nongnut , Rachakom Chanban , Soison Ubonrat , Apisarnthanarak Anucha 
Published: March 2021

AbstractAimThis study examined the effects of multimodal strategies on knowledge and practices in preventing multidrug‐resistant organism (MDRO) transmission among healthcare personnel (HCP), and to investigate MDRO transmission in two surgical intensive care units (SICUs).DesignA quasi‐experimental study with a one‐group pretest–posttest design.MethodsWe recruited 62 HCP. Data were collected during 2017–2019. Multimodal strategies, including training, educational and reminder posters, an educational YouTube channel, champions and feedback, were used to enhance knowledge and practices. Data were analysed using Wilcoxon signed‐rank test and chi‐square test.ResultsAfter the intervention, median knowledge scores increased from 16.0 to 17.0 (p = .001), and overall correct MDRO prevention practices increased from 76.6% to 94.0% (p < .001). The MDRO transmission rate decreased from 25% to 0% (p < .001).ConclusionThe findings indicate that multimodal strategies could enhance knowledge and practices for preventing MDRO transmission among HCP and could reduce the MDRO transmission rate in SICUs.
In situ construction of fiber‐supported micro‐porous char structure to enhance anti‐ablative performance of silicone rubber composites
Authors: Huang Yisen , Kong Yiran , Yan Liwei , Zou Huawei , Chen Yang , Liang Mei 
Published: March 2021

AbstractAblation‐resistant polymeric composites play a crucial role in the thermal protection system for the entire aerospace industry. Constructing a stable char layer especially with low thermal conductivity is essential to enhance the ablation resistant properties of polymer‐based ablatives. In this article, basic magnesium carbonate (MgCO3) and carbon fibers (CFs) were introduced to silicone rubber with an aim of building fiber‐supported micro‐porous char structure in situ, thereby improving ablation resistance properties. Thermogravimetric analyses revealed that the addition of MgCO3significantly increased the char residue of the composites. Oxyacetylene torch tests indicated that the addition of MgCO3/CFs greatly improved the thermal insulation of the composites, and the linear ablation rates of the composites were reduced by 30.76% compared to the virgin silicone rubber. Shore A hardness and thermal conductivity tests revealed that composites with 10 phr MgCO3exhibited a char structure with proper strength and low thermal conductivity. SiC, Mg2SiO4, and MgSiO3were produced in the MgCO3/CFs‐modified composites, as characterized by X‐ray diffraction. Combined with macro lens and scanning electron misroscopy, it was proven that a fiber‐supported micro‐porous and thermally insulated char structure was conducive to the improvement of the ablation properties, which can be applied to aerospace systems for thermal shielding applications.
Tuning morphology of siloxane bond‐based polybenzoxazines by controlling the sol–gel and curing processes
Authors: Forchetti Casarino Agustin , Bortolato Santiago Andrés , Estenoz Diana Alejandra , Spontón Marisa Elisabet 
Published: March 2021

AbstractNovel polybenzoxazine/polysilsesquioxane nanocomposites were synthesized with uniform and reproducible structural morphology, high Tg, and good thermal stability. Polysilsesquioxane was oriented in a nanometer‐size lamellar structure. Benzoxazine monomer based on silane (BA‐3aptms) was synthesized by reaction between bisphenol A, 3‐(trimethoxysilyl)propylamine, and paraformaldehyde in a 1:2:4 molar ratio. Four experimental conditions of the two stage sol–gel process for polysilsesquioxane were studied, and their effect on the material characteristics investigated. In the first stage, hydrolysis was favored, while the second stage mostly consisted of condensation. The reaction condition with the longest hydrolysis time allowed the increase of the concentration of silanol units and the selective condensation, favoring the formation of a higher amount of cage‐like cyclic structures. In addition, this experimental procedure was well controlled so that the sol–gel and oxazine‐ring opening reactions were extremely reproducible from batch to batch. All processes were monitored by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis and dynamic mechanical thermal analysis, scanning electron and transmission electron microscopies, and X‐ray diffraction. A chemometric approach based on a multivariate curve resolution model was applied to the FTIR spectra, which allowed the identification of four reaction components associated with the sol–gel and the curing processes.
Conservative management of congenital bronchial atresia: The Bambino Gesù children's hospital experience
Authors: Zarfati Angelo , Voglino Valerio , Tomà Paolo , Cutrera Renato , Frediani Simone , Inserra Alessandro 
Published: March 2021

AbstractIntroductionCongenital bronchial atresia (CBA) is a rare airway malformation. No management guidelines exist because of limited evidence: treatment, surgical or conservative, is based on consensus and opinion. Objective: To review the experience of a pediatric tertiary center and provide additional data about nonsurgical management of CBA and its outcomes after a structured follow‐up, and to help formulate appropriate evidence‐based guidelines.MethodsA retrospective analysis of clinical, radiological, surgical, and pathological data of all pediatric patients with suspicion of CBA referred to the surgical department of the Bambino Gesù children's hospital of Rome between December 2013 and 2019, along with a review of the literature.ResultsAmong the 18 children initially included in the study, 2 were lost to follow‐up after radiological diagnosis, 4 underwent surgery for radiological suspicion of other pulmonary malformations. The final population is composed of 12 conservatively managed patients. At the end of the follow‐up (median: 29 months, range 3–61), 1 patient (8%) was symptomatic.ConclusionConservative management for CBA appears to be safe. Surgery should be reserved for patients with symptomatic or complicated cases.
Improving integrative 3D modeling into low‐ to medium‐resolution electron microscopy structures with evolutionary couplings
Authors: McCafferty Caitlyn L. , Taylor David W. , Marcotte Edward M. 
Published: March 2021

AbstractElectron microscopy (EM) continues to provide near‐atomic resolution structures for well‐behaved proteins and protein complexes. Unfortunately, structures of some complexes are limited to low‐ to medium‐resolution due to biochemical or conformational heterogeneity. Thus, the application of unbiased systematic methods for fitting individual structures into EM maps is important. A method that employs co‐evolutionary information obtained solely from sequence data could prove invaluable for quick, confident localization of subunits within these structures. Here, we incorporate the co‐evolution of intermolecular amino acids as a new type of distance restraint in the integrative modeling platform in order to build three‐dimensional models of atomic structures into EM maps ranging from 10–14 Å in resolution. We validate this method using four complexes of known structure, where we highlight the conservation of intermolecular couplings despite dynamic conformational changes using the BAM complex. Finally, we use this method to assemble the subunits of the bacterial holo‐translocon into a model that agrees with previous biochemical data. The use of evolutionary couplings in integrative modeling improves systematic, unbiased fitting of atomic models into medium‐ to low‐resolution EM maps, providing additional information to integrative models lacking in spatial data.
Effective collisional cross‐section of small ions in the gas phase: Application to ion mobility spectrometry
Authors: Parchami Razieh , Tabrizchi Mahmoud 
Published: March 2021

RationaleThe observed drift times of monoatomic ions, including alkali metal ions and halide anions, are not fully consistent with their size. When the effect of mass is included through the Mason–Schamp equation, the deviation gets worse so that the trend of the experimental collisional cross‐sections becomes completely opposite to what is expected. This is attributed to the stronger local electric field around smaller ions. The strong electric field in the vicinity of a small ion leads to strong ion–neutral interactions and creates a drag force against ion motion. The smaller the ions, the stronger the interaction, because of the higher charge density.MethodsIn view of this, a modified equation is introduced to describe the relationship between the observed drift times or ion mobilities and the cross‐sections of small ions. Here, for small ions with high charge density, the experimental collision cross‐section is expressed as the effective collision cross‐section, Ωeff = σi(1 + α/ri3), that takes into account both intrinsic ion size, σi, and the ion–molecule interactions through a correction term of α/ri3, which is proportional to the charge density.ResultsA linear fit of the drift times of alkali metal ions and halide anions to the proposed equation showed relative deviations of <8.2%. The model successfully predicted the drift time of other small diatomic ions with reasonable error.ConclusionsThe proposed model can be used as a simple and efficient relationship in predicting the effective cross‐section of small ions.
Event‐triggered and self‐triggered gain scheduling control of input constrained systems with applications to the spacecraft rendezvous
Authors: Zhang Kai , Zhou Bin , Jiang Huaiyuan , Duan Guangren 
Published: March 2021

AbstractThis article studies event‐triggered and self‐triggered gain scheduling control design for semi‐global stabilization of input constrained linear systems. Using the parametric Lyapunov equation (PLE), a event‐triggered gain scheduling control, which can increase the convergence rate of the closed‐loop systems by designing a gain scheduling scheme and save the communication resources by building an event generator, is designed. In order to avoid continuously monitoring the system states, the self‐triggered gain scheduling control algorithms are also designed. The non‐occurrence of the Zeno phenomenon and the boundedness of the parameter in the PLE are proved. The impact of the parameter on the minimal inter‐event time is analyzed, which allows us to find easily a trade‐off between the inter‐event times and the control performance. Another advantage of the designed methods is that the controller is linear. Finally, the proposed control algorithms are applied to stabilize the spacecraft rendezvous control system and the numerical simulation result shows the efficacy of the control algorithms.
Laser‐Guided Corrosion Control: A New Approach to Tailor the Degradation of Mg‐Alloys
Authors: Pou‐Álvarez Pablo , Riveiro Antonio , Nóvoa Xosé Ramón , Jin Xueze , del Val Jesús , Comesaña Rafael , Boutinguiza Mohamed , Lusquiños Fernando , Jones Julian R. , Pérez‐Prado María Teresa , Pou Juan 
Published: March 2021

AbstractDespite corrosion being commonly seen as a problem to be avoided, applications such as batteries or biodegradable implants do benefit from corrosion‐like phenomena. However, current strategies address corrosion control from a global perspective for a whole component, without considering local adaptations to functionality specifications or inhomogeneous environments. Here, a novel concept is presented: the local control and guidance of corrosion through a laser surface treatment. Immersion tests in saline solution of AZ31 magnesium alloy samples show degradation rates reduced up to 15 times with the treatment, owing to a fast passivation after the induced microstructural modifications. By controlling the treatment conditions, the degradation can be restricted to delimited regions and driven towards specific directions. The applicability of the method for the design of tailored degradation biomedical implants is demonstrated and uses for cathodic protection systems and batteries can also be anticipated.