bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preconditioning of AISI 304 stainless steel surfaces in the presence of flavins—Part I: Effect on surface chemistry and corrosion behavior
Authors: Wurzler Nina , Sobol Oded , Altmann Korinna , Radnik Jörg , Ozcan Ozlem 
Published: December 2020

AbstractStainless steel AISI 304 surfaces were studied after a mild anodic polarization for oxide growth in the presence and absence of two derivatives of vitamin B2 (riboflavin and flavin mononucleotide) that can be secreted by metal‐reducing bacteria and act as a chelating agent for iron species. The alterations in oxide chemistry were studied by means of surface‐sensitive techniques such as X‐ray photoelectron spectroscopy and time‐of‐flight secondary ion mass spectrometry analysis. The complementary electrochemical characterization revealed a preferential growth of an oxide/hydroxide iron‐rich film that is responsible for an altered pit initiation and nucleation behavior. These findings suggest that as the corrosion behavior is determined by the interplay of the chemical and electronic properties, only a mild anodic polarization in the presence of redox‐active molecules is able to alter the chemical and electronic structure of the passive film formed on stainless steel AISI 304. This helps to achieve a profound understanding of the mechanisms of microbially influenced corrosion (MIC) and especially the possible effects of the redox‐active biomolecules, as they may play an important role in the corrosion susceptibility of stainless steel surfaces.
Unipolar plasma electrolytic oxidation: Waveform optimisation for corrosion resistance of commercially pure titanium
Authors: Casanova Luca , Vicentini Livio , Pedeferri MariaPia , Ormellese Marco 
Published: December 2020

AbstractThis study deals with the anodisation of titanium grade 2 in 0.5‐M sulphuric acid using a pulsed signal in a unipolar regime. The electrical parameters investigated are voltage, frequency and duty cycle. The use of duty cycles with a high percentage of anodic polarisation (90%), combined with high frequencies (1000 Hz) and the higher voltage tested (220 V), favoured the establishment of a plasma regime involving strong dielectric discharges, allowing the growth of thicker oxides but with rough architecture. The corrosion resistance of the formed film has been characterised by potentiodynamic tests in 0.5‐M NaBr for localised corrosion resistance and by immersion tests in 10% v/v sulphuric acid solution for a uniform corrosion assessment. Current–time curves, visual observations and electron microscope analysis (scanning electron microscopy, energy‐dispersive X‐ray spectroscopy) were the tools selected to provide a correlation between technological parameters and oxide growth mechanism. For localised and uniform corrosion, anodisation at 220 V with a high level of anodic polarisation (90%) and frequency (1000 Hz) was verified to be particularly advantageous.
Solid Polymer Electrolytes Based on Polylactic Acid Nanofiber Mats Coated with Polypyrrole
Authors: Gisbert Roca Fernando , García‐Bernabé Abel , Compañ Moreno Vicente , Martínez‐Ramos Cristina , Monleón Pradas Manuel 
Published: December 2020

AbstractThe production of electroconductive nanofiber membranes made from polylactic acid (PLA) coated with polypyrrole (PPy) is investigated, performing a scanning of different reaction parameters and studying their physicochemical and dielectric properties. Depending on PPy content, a transition between conduction mechanisms is observed, with a temperature‐dependent relaxation process for samples without PPy, a temperature‐independent conduction process for samples with high contents of PPy and a combination of both processes for samples with low contents of PPy. A homogeneous and continuous coating is achieved from 23 wt% PPy, observing a percolation effect around 27 wt% PPy. Higher wt% PPy allow to obtain higher conductivities, but PPy aggregates appear from 34% wt% PPy. The high conductivity values obtained for electrospun membranes both through‐plane and in‐plane (above 0.05 and 0.20 S cm–1, respectively, at room temperature) for the highest wt% of PPy, their porous structure with high specific surface area and their thermal stability below 140 °C make them candidates for many potential applications as solid polymer electrolytes in, for example, batteries, supercapacitors, sensors, photosensors, or polymer electrolyte membrane fuel cells (PEMFCs). In addition, the biocompatibility of PLA‐PPy membranes expand their potential applications also in the field of tissue engineering and implantable devices.
Time‐efficient measurement of subtle blood–brain barrier leakage using a T1 mapping MRI protocol at 7 T
Authors: van den Kerkhof Marieke , Voorter Paulien H. M. , Canjels Lisanne P. W. , de Jong Joost J. A. , van Oostenbrugge Robert J. , Kroon Abraham A. , Jansen Jacobus F. A. , Backes Walter H. 
Published: December 2020

PurposeBlood–brain barrier (BBB) disruption is commonly measured with DCE‐MRI using continuous dynamic scanning. For precise measurement of subtle BBB leakage, a long acquisition time (>20 minutes) is required. As extravasation of the contrast agent is slow, discrete sampling at strategic time points might be beneficial, and gains scan time for additional sequences. Here, we aimed to explore the feasibility of a sparsely sampled MRI protocol at 7 T.MethodsThe scan protocol consisted of a precontrast quantitative T1 measurement, using an MP2RAGE sequence, and after contrast agent injection, a fast‐sampling dynamic gradient‐echo perfusion scan and two postcontrast quantitative T1 measurements were applied. Simulations were conducted to determine the optimal postcontrast sampling time points for measuring subtle BBB leakage. The graphical Patlak approach was used to quantify the leakage rate (Ki) and blood plasma volume (vp) of normal‐appearing white and gray matter.ResultsThe simulations showed that two postcontrast T1 maps are sufficient to detect subtle leakage, and most sensitive when the last T1 map is acquired late, approximately 30 minutes, after contrast agent administration. The in vivo measurements found Ki and vp values in agreement with other studies, and significantly higher values in gray matter compared with white matter (both p = .04).ConclusionThe sparsely sampled protocol was demonstrated to be sensitive to quantify subtle BBB leakage, despite using only three T1 maps. Due to the time‐efficiency of this method, it will become more feasible to incorporate BBB leakage measurements in clinical research MRI protocols.
Moisture effect on the mechanical properties of additively manufactured continuous carbon fiber‐reinforced Nylon‐based thermoplastic
Authors: Kikuchi Bruno Calheiros , Bussamra Flávio Luiz de Silva , Donadon Maurício Vicente , Ferreira Rafael Thiago Luiz , Sales Rita de Cássia Mendonça 
Published: December 2020

AbstractAdditively manufactured composites have been demonstrating promising results with the development of new materials of high mechanical performance, which draws attention from several fields, for example, biomedical, electronics and aeronautics. However, as such materials are based on novel technologies, it is necessary to better understand their resulting characteristics and properties. For instance, evaluating the effect of environmental conditions on their mechanical performance is important, especially when moisture‐sensitive polymers such as polyamide (PA) are employed as matrix. This work aims to understand and to characterize the moisture effect on the mechanical properties of additively manufactured Nylon and continuous carbon fiber (CF)‐reinforced Nylon‐based thermoplastic. Tensile and compressive tests were carried out in accordance with ASTM standards for the printed samples at their maximum moisture content and for samples submitted to drying after the saturated condition. Moreover, moisture absorption and swelling behaviors were assessed and discussed. The experimental results showed that moisture significantly affects the fiber/matrix interface, as well as the adhesion between printed filaments. These changes led to a decrease in the general mechanical properties in saturated state, including those in the fiber direction. Furthermore, a permanent degradation was observed in some properties after drying. Thus, the importance of considering water content and aging effect on the characterization and engineering application of 3D printed CF/PA composite was evidenced.
The commitment of barley microspores into embryogenesis correlates with miRNA‐directed regulation of members of the SPL, GRF and HD‐ZIPIII transcription factor families
Authors: Bélanger Sébastien , Baldrich Patricia , Lemay Marc‐André , Marchand Suzanne , Esteves Patricio , Meyers Blake C. , Belzile François 
Published: December 2020

AbstractMicrospore embryogenesis is a model for developmental plasticity and cell fate decisions. To investigate the role of miRNAs in this development, we sequenced sRNAs and the degradome of barley microspores collected prior to (day 0) and after (days 2 and 5) the application of a stress treatment known to induce embryogenesis. Microspores isolated at these timepoints were uniform in both appearance and in their complements of sRNAs. We detected 68 miRNAs in microspores. The abundance of 51 of these miRNAs differed significantly during microspore development. One group of miRNAs was induced when the stress treatment was applied, prior to being repressed when microspores transitioned to embryogenesis. Another group of miRNAs were up‐regulated in day‐2 microspores and their abundance remained stable or increased in day‐5 microspores, a timepoint at which the first clear indications of the transition toward embryogenesis were visible. Collectively, these miRNAs might play a role in the modulation of the stress response, the repression of gametic development, and/or the gain of embryogenic potential. A degradome analysis allowed us to validate the role of miRNAs in regulating 41 specific transcripts. We showed that the transition of microspores toward the embryogenesis pathway involves miRNA‐directed regulation of members of the ARF, SPL, GRF, and HD‐ZIPIII transcription factor families. We noted that 41.5% of these targets were shared between day‐2 and day‐5 microspores while 26.8% were unique to day‐5 microspores. The former set may act to disrupt transcripts involved in pollen development while the latter set may drive the commitment to embryogenesis.
Cytokinin‐regulated targets of Cytokinin Response Factor 6 are involved in potassium transport
Authors: Hughes Ariel M. , Zwack Paul J. , Cobine Paul A. , Rashotte Aaron M. 
Published: December 2020

AbstractCytokinin (CK) is a plant hormone crucial to plant development and growth. Cytokinin Response Factor 6 (CRF6) is a CK‐induced transcription factor that is part of the CK signaling cascade. While the role of CRF6 has been examined in oxidative stress response, there has been surprisingly little investigation of CRF6 in the context of CK signaling, including identifying CK‐regulated targets of CRF6. Here, we conduct a transcriptomic study of Arabidopsis examining the CRF6 mutant (crf6) in the presence and absence of CK, revealing 163 downstream CRF6‐dependent CK‐regulated differentially expressed genes (DEGs). 15.3% of these DEGS were found as overlapping with larger number of standardly identified CK‐regulated DEGs, suggesting that CRF6 is involved in regulating a subset of downstream CK responses through these gene targets. The general transcriptional regulation of CRF6‐dependent CK‐regulated DEGs indicates that CRF6 may function as a negative regulator of CK response. We investigated one subset of CRF6 CK‐dependent targets (SKOR, HAK5, and NRT1. 5) involved in an underexamined functional role of CK response: the uptake and transportation of potassium. To determine how CK and CRF6 are involved in potassium acquisition and distribution, ionomic and physiological experiments were conducted on plants grown in media with sufficient and deficient potassium concentrations and in the presence and absence of CK. In order to investigate how CK alone affects potassium transport, similar experiments were performed on skor, hak5, and nrt1.5 mutant lines of these CRF6‐dependent CK‐regulated targets. These findings indicate novel connections between CK and potassium transport, which appear to be regulated in a CRF6‐dependent manner.
Trajectories of oral glucose tolerance testing in cystic fibrosis
Authors: Patel Monal , McCracken Courtney , Daley Tanicia , Stecenko Arlene , Linnemann Rachel 
Published: December 2020

AbstractIntroductionAnnual oral glucose tolerance testing (OGTT) is the recommended screening modality for cystic fibrosis‐related diabetes (CFRD) in patients with cystic fibrosis (CF). This study aimed to determine if there were patterns of progression of worsening glucose homeostasis in pediatric CF patients and to explore any relationship to lung function.MethodsWe conducted a retrospective cohort study of CF patients, ages 10–18 years, without CFRD and with ≥3 OGTT from 2013 to 2016. Latent class mixture models were used to determine unique trajectories of 2‐h OGTT glucose values (2hrGlu) over time. Multivariable linear models were used to adjust for clinical covariates.ResultsFor 63 subjects, three unique 2hrGlu trajectories were identified: high (impaired glucose tolerance) to higher (n = 8), low (normal glucose tolerance [NGT]) and increasing (n = 47), and low (NGT) and flat (n = 8). There was high variability of 2hrGlu, but most patients belonged to a trajectory that increased over time. After controlling for age, pancreatic insufficiency, modulator use, and mutation type, there was a significant difference in the study baseline forced expiratory volume in 1 s percent predicted (ppFEV1) in the high to higher group compared to the low and increasing and low and flat groups (p < .005).DiscussionAmong pediatric CF patients without diabetes, three 2hrGlu trajectories were identified with 87% of patients exhibiting a trajectory where glucose homeostasis worsened over time. Starting ppFEV1 was lower in those with a high to higher trajectory, supporting that lower lung function is present early in the development of CFRD.
Antifungal properties of natural products from Pterocarya tonkinensis against phytopathogenic fungi
Authors: Thi Ngo Men , Han Jae Woo , Van Nguyen Minh , Le Dang Quang , Kim Hun , Choi Gyung Ja 
Published: December 2020

AbstractBACKGROUNDIn the search for new natural resources showing antifungal activity, we found that the methanol extract of Pterocarya tonkinensis (Fr.) Dode suppressed the disease development caused by fungi. The objectives of this article were (i) to isolate and identify the antifungal substances from the Pterocarya tonkinensis extract based on a bioassay‐guided fractionation and (ii) to investigate their potential as a biocontrol agent with their antifungal activities in vitro and in vivo.RESULTSEighteen compounds were identified from the methanol extract of Pterocarya tonkinensis, including two new natural products 1 and 2: 1, pterocaryalactone; 2, pterocaryafuranone; 3, (1S, 6R)‐9‐hydroxymegastigm‐7‐en‐3‐one; 4, (S)‐dimethyl malate; 5, α‐linolenic acid; 6–8, α‐tetralones; 9, (R)‐methyl‐2‐hydroxyl‐3‐phenyl‐propanoate; 10, (E)‐4‐hydroxycinnamic acid methyl ester; 11–14, diarylheptanoids, and 15–18, pentacyclic triterpenoids. Based on the results of the in vitro antifungal assay, Magnaporthe oryzae and Phytophthora infestans were the most sensitive to the isolated compounds among the tested phytopathogenic fungi. When ten active compounds were applied onto plants at a concentration of 100 or 500 μg mL−1, compounds 1 and 8 effectively suppressed rice blast disease, and compounds 15 and 16 not only strongly reduced the development of blast on rice but also effectively controlled the development of late blight on tomatoes.CONCLUSIONThis is the first report to evaluate the in vitro and in vivo antifungal activities of the isolated compounds from a methanol extract of Pterocarya tonkinensis against phytopathogenic fungi, and our results suggest that Pterocarya tonkinensis and its substances can be used as a source to develop natural fungicides. © 2020 Society of Chemical Industry
A new approach to design a finite‐time extended state observer: Uncertain robotic manipulators application
Authors: Razmjooei Hamid , Shafiei Mohammad Hossein 
Published: December 2020

AbstractIn this article, a new approach to design a finite‐time extended state observer (FT‐ESO) for a class of uncertain nonlinear systems is proposed based on a novel coordinate transformation. First, a time‐varying extended state observer (ESO) is designed to make the estimation error uniformly bounded. In this regard, the dynamic of the estimation error is transformed into a linear system with a generalized disturbance term as its input. Then, the time‐varying gains of the ESO are designed to stabilize the system and consequently, to converge the estimation error to the neighborhood of zero and to remain uniformly bounded as t → t0 + T. In this article, without any knowledge about the disturbance, and uncertainties, a fault‐tolerant FT‐ESO is designed. Simulation results demonstrate the effectiveness of the proposed finite‐time ESO for serial robotic manipulators with any number of links, in the presence of disturbances and an unknown fault.
A closer look at US schools: What characteristics are associated with scientific literacy? A multivariate multilevel analysis using PISA 2015
Authors: You Hye Sun , Park Sunyoung , Delgado Cesar 
Published: December 2020

AbstractThe purpose of this study is to examine the characteristics of US schools associated with two measures of scientific literacy (content knowledge and “procedural and epistemic” knowledge) using the 2015 Programme for International Student Assessment (PISA) data. Because outcomes are nested within students, and students within schools, a multivariate three‐level modeling method was employed. About 21% of the total variance in science performance lies between schools, indicating that school characteristics are important in predicting scientific literacy. The results revealed clearly significant and positive relationships of the student‐level variables of grade, enjoyment, motivation, and economic/social/cultural status (ESCS) with both measures of science literacy, after controlling for school factors. A significant gender difference is seen in science content knowledge in favor of males. At the school level, the results from the full model suggest that school ESCS, climate, and school type are significant predictors of all students' performance. Surprisingly, school size, teaching experience, professional development (PD) participation, and science‐specific resources are not found to contribute significantly to achievement. Considerable variability is also evident among schools on student performance in both science knowledge domains as a result of school variables. For both low‐ and mid–high‐achieving students, the most significant school factor is school mean ESCS. PD participation and school climate are significantly associated with student performance only for the average and high‐performing groups. This paper can inform policymakers, researchers, and educators on how US schools can be supported to improve science learning.
Stabilizing Pd Nanoparticles in Supported‐Ionic‐Liquid‐Phase (SILP) Catalyst Using Polydimethylsiloxane Via Hydrophobic Structure for Boosting Hydrodechlorination of 4‐Chlorophenol
Authors: Chen Xianlang , Chen Jingjing , Zhang Jieyu , Tang Tian , Xu Qian qian , Zhao Bo , Lu Jinyue , Li Rongrong , Han Deman 
Published: December 2020

AbstractPolydimethylsiloxane (PDMS) and 1‐butyl‐3‐methylimidazolium trifluoroacetate ionic liquid (IL) modified palladium‐based catalyst supported on activated carbon have been prepared and measured for hydrodechlorination of 4‐chlorophenol (4‐CP) using (HCOOH + HCOONa) as hydrogen source. For turnover frequency of 4‐CP HDC reaction to obtain a value of 3.0×105 h−1 and five times better than the value of the catalyst without PDMS. This may be due to the addition of PDMS which can promote the dispersion of the nanoparticles. The conversion of the catalyst HDC decreased from 100 % to 92 % after 5 times which may be due to a hydrophobic structure formed in the catalyst after the addition of PDMS.
Novel and Efficient Knoevenagel Condensation over Mesoporous SBA‐15 Supported Acetate‐functionalized Basic Ionic Liquid Catalyst
Authors: Rui Li Jing , Chen Chen , Lin Hu Yu 
Published: December 2020

AbstractA type of multifunctional mesoporous SBA‐15 supported imidazolium ionic liquids SBA‐15@IL‐OAc have been designed and synthesized, characterized and tested as heterogeneous catalysts in the Knoevenagel condensation. The prepared catalysts exhibit good catalytic performances in the reaction at room temperature, especially the supported ionic liquid SBA‐15@IL‐OAc(0.8) with excellent yields of 90∼98 %, probably due to the synergetic effect between acetate anion sites of imidazolium ionic liquid and hydroxyl active sites of SBA‐15. In addition, the recyclability of the heterogeneous catalyst was tested, and the cycle test showed that the catalyst could be reused five times without significantly reducing the catalytic activity.
Novel Carborane Compounds Based on Cyclooxygenase‐2 Inhibitors for Effective Boron Neutron Capture Therapy of Tongue Squamous Cell Carcinoma
Authors: Zhang Taofeng , Du Shaobo , Wang Yu , Guo Yanzhu , Yi Yangman , Liu Bin , Liu Yang , Chen Ximeng , Zhao Quanyi , He Dian , Wang Zhen , Zhang Hong , Ma Qianlong 
Published: December 2020

AbstractTo date, the mortality of tongue squamous cell carcinoma (TSCC) is still high, COX‐2 is highly expressed in the head and neck cancers, and targeting COX‐2 is a potential treatment for TSCC. Herein, a series of novel carborane compounds based on COX‐2 inhibitors have been developed for the effective treatment of TSCC by boron neutron capture therapy (BNCT). Notably, the compound 1 had high COX‐2 selectivity and low cytotoxicity against CAL27 cells. Meanwhile, the compound 1 had higher selectivity and uptake of CAL27 cells compared to the positive control group sodium borocaptate (BSH). The apoptosis of CAL27 cells treated with the compound 1 during BNCT was significantly induced by breaking DNA double strands and generating excess reactive oxygen species, and the proliferation of cancer cells was inhibited by down‐regulating the expression of cytokines associated with phosphatidylinositide 3‐kinases/protein kinase B (PI3K/Akt) and mitogen‐activated protein kinases (MAPKs) signaling pathways in BNCT. Thus, the carborane compounds based on COX‐2 inhibitors have the potential to effectively treat tongue squamous cell carcinoma through BNCT.
Post‐traumatic stress disorder and depressive symptoms following a Herdsmen attack: The role of life meaning in mediating trait mindfulness
Authors: Aliche Chinenye Joseph , Ifeagwazi Chuka Mike , Yankouskaya Ala , Comoretto Amanda , Wezyk Agata , Ventouris Annita , Panourgia Constantina 
Published: December 2020

AbstractIt is well established that mindfulness is beneficial in decreasing post‐traumatic stress disorder (PTSD) and depression symptoms, but the explanatory pathway and processes through which this happens are still not clear. The present study investigated two mediation models that explored the psychological process of presence of meaning in life as a mechanism connecting mindfulness to reduced PTSD and depressive symptoms in survivors of a violent attack. A sample of 577 survivors of the Fulani herdsmen attack completed relevant self‐report measures and the bootstrap method was used to test the models for direct, indirect and total effects. Results revealed that mindfulness was negatively associated to PTSD symptoms, and that this association was fully mediated by the ability to find meaning in life. Mindfulness was also indirectly associated to depression through a greater sense of meaning in life. The findings of this study suggest that the presence of meaning in life is the pathway through which mindfulness alleviates PTSD and depression symptoms, and could therefore serve as an intervention target to decrease such negative outcomes in trauma survivors.