bluuebunny/crossref_metadata_2025_split huggingface dataset:
Low‐T CO Oxidation over Cu−CHA Catalysts in Presence of NH3: Probing the Mobility of CuII Ions and the Role of Multinuclear CuII Species
Authors: Villamaina Roberta , Iacobone Umberto , Nova Isabella , Ruggeri Maria Pia , Collier Jillian , Thompsett David , Tronconi Enrico 
Published: May 2020

AbstractWe use dry CO oxidation to probe CuII dimers in Cu−CHA catalysts in the presence of ammonia. Samples with different Cu/Al and Si/Al ratios were exposed to CO in He at 200 °C after either one of two catalyst pre‐treatments: (i) pre‐oxidization in 8 % O2/He at 550 °C for 1 hour; (ii) pre‐oxidation in 8 % O2/He at 550 °C for 1 hour followed by NH3 saturation at 200 °C in O2. Pre‐adsorbed NH3 was necessary to observe a significant CO2 evolution, the rate of CO2 formation being second order in the CuIIOH fraction of the CuII sites. This is direct evidence that NH3, not involved in the CO oxidation chemistry, favours the formation of CuII dimers with removable oxygen by ligating with and mobilizing isolated CuIIOH ions, otherwise inactive. These findings are relevant for the low‐temperature NH3−SCR redox mechanism over Cu−CHA, in which CuII dimers may play a role in parallel or in alternative to the isolated CuII sites so far proposed for the reduction half cycle of standard SCR.
Improving Broadband White‐Light Emission Performances of 2D Perovskites by Subtly Regulating Organic Cations
Authors: Jing Chang‐Qing , Wang Juan , Zhao Hui‐Fang , Chu Wen‐Xin , Yuan Yun , Wang Zhi , Han Meng‐Fei , Xu Te , Zhao Jian‐Qiang , Lei Xiao‐Wu 
Published: May 2020

AbstractRecently, 2D organic–inorganic hybrid lead halide perovskites have attracted intensive attention in solid‐state luminescence fields such as single‐component white‐light emitters, and rational optimization of the photoluminescence (PL) performance through accurate structural‐design strategies is still significant. Herein, by carefully choosing homologous aliphatic amines as templates, isotypical perovskites [DMEDA]PbCl4 (1, DMEDA=N,N‐dimethylethylenediamine) and [DMPDA]PbCl4 (2, DMPDA=N,N‐dimethyl‐1,3‐diaminopropane) having tunable and stable broadband bluish white emission properties were rationally designed. The subtle regulation of organic cations leads to a higher degree of distortion of the 2D [PbCl4]2− layers and enhanced photoluminescence quantum efficiencies (<1 % for 1 and 4.9 % for 2). The broadband light emissions could be ascribed to self‐trapped excitons on the basis of structural characterization, time‐resolved PL, temperature‐dependent PL emission, and theoretical calculations. This work gives a new guidance to rationally optimize the PL properties of low‐dimensional halide perovskites and affords a platform to probe the structure–property relationship.
Structure–Activity Relationship Study of a Potent α‐Thrombin Binding Aptamer Incorporating Hexitol Nucleotides
Authors: De Fenza Maria , Eremeeva Elena , Troisi Romualdo , Yang Hui , Esposito Anna , Sica Filomena , Herdewijn Piet , D'Alonzo Daniele , Guaragna Annalisa 
Published: May 2020

AbstractThe replacement of one or more nucleotide residues in the potent α‐thrombin‐binding aptamer NU172 with hexitol‐based nucleotides has been devised to study the effect of these substitutions on the physicochemical and functional properties of the anticoagulant agent. The incorporation of single hexitol nucleotides at the T9 and G18 positions of NU172 substantially retained the physicochemical features of the parent oligonucleotide, as a result of the biomimetic properties of the hexitol backbone. Importantly, the NU172‐TH9 mutant exhibited a higher binding affinity toward human α‐thrombin than the native aptamer and an improved stability even after 24 h in 90 % human serum, with a significant increase in the estimated half‐life. The anticoagulant activity of the modified oligonucleotide was also found to be slightly preferable to NU172. Overall, these results confirm the potential of hexitol nucleotides as biomimetic agents, while laying the foundations for the development of NU172‐inspired α‐thrombin‐binding aptamers.
Aggregation and Amyloidogenicity of the Nuclear Coactivator Binding Domain of CREB‐Binding Protein
Authors: Garcia Ana Maria , Giorgiutti Christophe , El Khoury Youssef , Bauer Valentin , Spiegelhalter Coralie , Leize‐Wagner Emmanuelle , Hellwig Petra , Potier Noelle , Torbeev Vladimir 
Published: May 2020

AbstractThe nuclear coactivator binding domain (NCBD) of transcriptional co‐regulator CREB‐binding protein (CBP) is an example of conformationally malleable proteins that can bind to structurally unrelated protein targets and adopt distinct folds in the respective protein complexes. Here, we show that the folding landscape of NCBD contains an alternative pathway that results in protein aggregation and self‐assembly into amyloid fibers. The initial steps of such protein misfolding are driven by intermolecular interactions of its N‐terminal α‐helix bringing multiple NCBD molecules into contact. These oligomers then undergo slow but progressive interconversion into β‐sheet‐containing aggregates. To reveal the concealed aggregation potential of NCBD we used a chemically synthesized mirror‐image d‐NCBD form. The addition of d‐NCBD promoted self‐assembly into amyloid precipitates presumably due to formation of thermodynamically more stable racemic β‐sheet structures. The unexpected aggregation of NCBD needs to be taken into consideration given the multitude of protein–protein interactions and resulting biological functions mediated by CBP.
Enantiomeric separation of malathion and malaoxon and the chiral residue analysis in food and environmental matrix
Authors: Hua Yifan , Zhou Qian , Wang Peng , Zhou Zhiqiang , Liu Donghui 
Published: May 2020

AbstractMalathion is a widely used chiral phosphorus insecticide, which has a more toxic chiral metabolite malaoxon. In this work, the enantiomers of malathion and malaoxon were separated by high‐performance liquid chromatography‐mass/mass (HPLC‐MS/MS) with chiral columns using acetonitrile/water or methanol/water as mobile phase, and the chromatographic conditions were optimized. Based on the chiral separation, the chiral residue analysis methods for the enantiomers in soil, fruit, and vegetables were set up. Two pairs of the enantiomers were better separated on CHIRALPAK IC chiral column, and baseline simultaneous separations of malathion and malaoxon enantiomers were achieved with acetonitrile/water (40/60, v/v) as mobile phase at a flow rate of 0.5 mL/min. The elution orders were −/+ for both malathion and malaoxon measured by an optical rotation detector. The chiral residue analysis in soil, fruit, and vegetables was validated by linearity, recovery, precision, limit of detection (LOD), and limit of quantification (LOQ). The LODs and LOQs for the enantiomers of malathion were 1 μg/kg and 3–5 μg/kg and 0.08 μg/kg and 0.20–0.25 μg/kg for malaoxon enantiomers. Good linear calibration curves for each enantiomer in the matrices were obtained within the concentration range of 0.02–12 mg/L. The mean recoveries of the enantiomers of malathion and malaoxon ranged from 82.26% to 109.04%, with RSDs of 0.71–8.63%.The results confirmed that this method was capable of simultaneously determining the residue of malathion and malaoxon in food and environmental matrix on an enantiomeric level.
In vitro Biological Tests as the First Tools To Validate Magnetic Nanotheranostics for Colorectal Cancer Models
Authors: Martín María Julia , Gentili Claudia , Lassalle Verónica 
Published: May 2020

AbstractColorectal cancer (CRC) remains a leading cause of cancer death. Nanotechnology has focused on reaching more effective treatments. In this concern, magnetic nanoparticles (MNPs) have been studied for a wide range of biomedical applications related to CRC, such as diagnostic imaging, drug delivery and thermal therapy. However, limited research is currently found in the open literature that refers to nanosystems combining all these mentioned areas (theranostics). When developing nanosystems intended as theranostics applied to CRC, possible variations between patients must be considered. Therefore, multiple in vitro assays are required as guidance for future preclinical and clinical trials. The objective of this contribution is to evaluate the available and recent literature regarding the interactions of MNP and CRC models, aiming to critically analyze the information given by the commonly used assays and evaluate the data provided by each one with a view to implementing this novel technology in CRC diagnostics and therapy.
Human perceptual responses to multiple colors: A study of multicolor perceptual features modeling
Authors: Wang Shuang , Jiang Wei , Su Yanan , Liu Jingyu 
Published: May 2020

AbstractThis article models multicolor perceptual features to investigate human perceptual responses to multiple colors based on a subjective evaluation experiment. First, an image set containing 164 multicolor samples was constructed, and multicolor objective features containing two categories with 60 dimensions were designed and quantified. Based on this, the 164 samples were evaluated by 30 subjects based on nine perceptual descriptive variables, including “swell‐shrink,” “light‐dark,” and “far‐near.” Then, a mathematical model of multicolor perceptual features (nine descriptive variables) was established by support vector regression. Finally, this article conducted model evaluation and factor analysis, and the results showed that the model could predict multicolor perceptual features well. It was also observed that, unlike single‐color perception, space perception was produced when applying multiple colors.
Carbon Quantum Dots Co‐catalyzed with ZnO Nanoflowers and Poly (CTAB) Nanosensor for Simultaneous Sensitive Detection of Paracetamol and Ciprofloxacin in Biological Samples
Authors: Hatamluyi Behnaz , Modarres Zahed Fatemeh , Es'haghi Zarrin , Darroudi Majid 
Published: May 2020

AbstractA novel platform based incorporation of carbon quantum dots (CQDs) and zinc oxide nanoflowers (ZnO‐NFs) decorated with poly cetyltrimethylammonium bromide (CTAB) was developed as electrochemical sensor for the sensitive and selective simultaneous detection of Paracetamol (PAR) and Ciprofloxacin (CIP) in biological samples. For this, CQDs and ZnO‐NFs were first deposited on a glassy carbon electrode (GCE) and subsequently a Poly (CTAB) layer was grown onto their surfaces through electro‐polymerization. The synthesized nanostructures and the corresponding fabricated sensor were characterized by the techniques of TEM, XRD, FE‐SEM, and EDX analysis. Moreover electrochemical characterization by CV and DPV were performed to elucidate the construction process and electron transfer abilities of the CQDs/ZnO‐NFs/Poly(CTAB)/GCE. Increased sensitivity and efficiency of this sensing system was obtained due to the synergistic effects of CQDs, ZnO‐NFs and Poly (CTAB) with multi‐signal amplification. Under the optimum conditions, the DPV response of proposed sensor to PAR and CIP was linear at 0.05–30.0 μM and 0.01–30.0 μM, with the detection limit of 2.47 nM and 1.97 nM respectively. The sensor possessed high stability, reproducibility, sensitivity, and selectivity toward PAR and CIP detection, over potential interferents and presented high recovery percentage in the real sample matrices.
Treatment of partially hydrolyzed polyacrylamide by mixed bacteria isolated from wastewater
Authors: Dong Liang , Su Fei , Wang Yong‐Zhong 
Published: May 2020

AbstractIn this work, a mixed strain which could degrade hydrolyzed polyacrylamide (HPAM) was constructed based on SS5 and SS6 isolated from two wastewater samples. SS5 is a globular gram‐negative bacterium, and SS6 is a rod‐shaped gram‐negative bacterium. Moreover, SS5 and SS6 were identified as Acinetobacter sp. and Pseudomonas sp., respectively. The removal performance of the mixed strain was optimized using single‐factor experiment and response surface methodology. The maximal HPAM removal efficiency 29.78% was observed at pH 7.5, 35°C, 170 rpm rotation speed, and inoculum loading 3% (v/v) for 7 days. The optimal concentrations of nutrients were 0.32 g/L glucose, 0.21 g/L NaNO3, 2.10 g/L KH2PO4‐K2HPO4, and the HPAM removal efficiency reached 45.82%. Finally, the optimal HPAM concentration and the HPAM removal efficiency were 300 mg/L and 45.82%, respectively. The results indicate that the mixed strain was a potential candidate for dealing with oil‐ or gas‐field sewage with high hydrolyzed polyacrylamide concentration.
Fragility and risk assessment of freestanding building contents
Authors: Fragiadakis Michalis , Diamantopoulos Spyridon 
Published: May 2020

SummaryMultistorey buildings often have a valuable inventory consisting of objects that their possible damage during an earthquake will cause unacceptable losses. The paper presents a novel, fully performance‐based seismic reliability and risk assessment framework for freestanding structural components and contents that can be modelled as rocking rigid blocks. The seismic response of building contents depends on several parameters such as the geometry of the object, the dynamic characteristics of the building and the storey that the object is located. The demand at the storey level is first obtained, and then the response of the contents is calculated using the storey acceleration response history. The demand of the structure is obtained with the aid of a modified version of the Incremental Dynamic Analysis method and subsequently the fragility curves of the rocking building contents are derived for every storey of interest. Different options for fragility assessment are discussed, and the underlying details of the problem are investigated. A simplified approach, where the fragility of the freestanding components and the structure are derived separately, is also presented. The method combines existing fragility curves and thus is suitable for quickly assessing the reliability of a building's inventory, offering sufficient risk estimates.
Revisiting flexible polyurethane foam flammability in furniture and bedding in the United States
Authors: Morgan Alexander B. 
Published: May 2020

SummaryThe flammability of flexible polyurethane foam has been well studied to date, via smoldering and flaming ignition. Its contribution to fire loss in the United States has also been well documented, as the flammability of this material will contribute to large fire events when not protected from ignition and heat sources. Despite this known fire risk, fire protection approaches for polyurethane foam are being questioned in regards to fire protection performance, as well as proven and hypothesized concerns over health impacts before and after fire events. The flammability of flexible polyurethane foam in furniture and bedding is a clear and present danger that must be addressed, and this article discusses the current available technologies for fire protection, with pros and cons of these approaches. Known physical and chemical behavior of these foams in fires is discussed, as well as how this behavior contributes to large fire events. Finally, issues that still need further research and information to definitively address the polyurethane foam flammability in the United States is discussed.
Optimization of Supercritical Fluid Extraction of Paprika (cv. Reshampatti) Oil, Capsaicin and Pigments
Authors: Shah Nikunj A. , Prasad R.V. , Patel Bhaumik B. 
Published: May 2020

AbstractPaprika (Capsicum annuum L.) is a spice, utilized in culinary across the globe for its colour and pungency. A study was conducted to optimize the supercritical fluid extraction (SFE) process individually for selective extraction of paprika oil, capsaicin and pigments. Paprika oil was extracted by supercritical fluid—carbon dioxide at different process parameters: temperature (35‐75°C), pressure (100‐500 bar), extraction time (60‐180 minutes) and particle size (0.25‐1.25 mm) using central composite rotatable design (CCRD). The ANOVA results showed that yields of paprika oil, capsaicin and pigments were significantly (P ≤ .05) affected by the extraction process variables. Optimized SFE conditions, 65, 65 and 57.04°C temperature; 357.8, 200.62 and 400 bar pressure; 90, 90 and 100.89 minutes extraction time; and 0.78, 0.50 and 0.89 mm particle size, were obtained for optimum yield of paprika oil, capsaicin and pigments, respectively. Experimental yield of paprika oil, capsaicin and pigments at the optimized condition for respective compounds was 4.91% (w/w), 2.10% (w/w) and 16 319.9 NCV, and had good agreement with the predicted values. Antimicrobial activity of extracted paprika oil was found against E. coli, B. subtilus and S. aureus.
Lower cognitive baseline scores predict cognitive training success after 6 months in healthy older adults: Results of an online RCT
Authors: Roheger Mandy , Kalbe Elke , Corbett Anne , Brooker Helen , Ballard Clive 
Published: May 2020

AbstractBackgroundIdentifying predictors for general cognitive training (GCT) success in healthy older adults has many potential uses, including aiding intervention and improving individual dementia risk prediction, which are of high importance in health care. However, the factors that predict training improvements and the temporal course of predictors (eg, do the same prognostic factors predict training success after a short training period, such as 6 weeks, as well as after a longer training period, such as 6 months?) are largely unknown.MethodsData (N = 4,184 healthy older individuals) from two arms (GCT vs. control) of a three‐arm randomized controlled trial were reanalyzed to investigate predictors of GCT success in five cognitive tasks (grammatical reasoning, spatial working memory, digit vigilance, paired association learning, and verbal learning) at three time points (after 6 weeks, 3 months, and 6 months of training). Possible investigated predictors were sociodemographic variables, depressive symptoms, number of training sessions, cognitive baseline values, and all interaction terms (group*predictor).ResultsBeing female was predictive for improvement in grammatical reasoning at 6 weeks in the GCT group, and lower cognitive baseline scores were predictive for improvement in spatial working memory and verbal learning at 6 months.ConclusionOur data indicate that predictors seem to change over time; remarkably, lower baseline performance at study entry is only a significant predictor at 6 months training. Possible reasons for these results are discussed in relation to the compensation hypothesis. J Am Geriatr Soc 68:‐, 2020.
Toward a “treadmill test” for cognition: Improved prediction of general cognitive ability from the task activated brain
Authors: Sripada Chandra , Angstadt Mike , Rutherford Saige , Taxali Aman , Shedden Kerby 
Published: May 2020

AbstractGeneral cognitive ability (GCA) refers to a trait‐like ability that contributes to performance across diverse cognitive tasks. Identifying brain‐based markers of GCA has been a longstanding goal of cognitive and clinical neuroscience. Recently, predictive modeling methods have emerged that build whole‐brain, distributed neural signatures for phenotypes of interest. In this study, we employ a predictive modeling approach to predict GCA based on fMRI task activation patterns during the N‐back working memory task as well as six other tasks in the Human Connectome Project dataset (n = 967), encompassing 15 task contrasts in total. We found tasks are a highly effective basis for prediction of GCA: The 2‐back versus 0‐back contrast achieved a 0.50 correlation with GCA scores in 10‐fold cross‐validation, and 13 out of 15 task contrasts afforded statistically significant prediction of GCA. Additionally, we found that task contrasts that produce greater frontoparietal activation and default mode network deactivation—a brain activation pattern associated with executive processing and higher cognitive demand—are more effective in the prediction of GCA. These results suggest a picture analogous to treadmill testing for cardiac function: Placing the brain in a more cognitively demanding task state significantly improves brain‐based prediction of GCA.
Use of narrowband imaging for the diagnosis and screening of laryngeal cancer: A systematic review and meta‐analysis
Authors: Kim Do Hyun , Kim Yeonji , Kim Sung Won , Hwang Se Hwan 
Published: May 2020

AbstractWe evaluated the diagnostic accuracy of narrowband imaging (NBI) in terms of detecting laryngeal cancer compared to that of white light endoscopy (WLE). Two reviewers individually searched the six databases for studies published between the first record date and December 31, 2019. We recorded the numbers of true positives, true negatives, false positives, and false negatives. Quality Assessment of Diagnostic Accuracy Studies ver. 2 software was used to assess the studies. The extent of the inter‐rater agreement was also measured. The diagnostic odds ratio (OR) associated with NBI was 87.463 (95% confidence interval [CI]: 46.968, 160.873). The area under the summary receiver operating characteristic curve was 0.954. NBI was more diagnostically accurate than WLE, which was associated with a diagnostic OR of 13.750. NBI affords high diagnostic accuracy, thus supporting a role for NBI in the diagnostic work‐up of laryngeal cancer.
Adverse effect of delayed pushing on postpartum blood loss in nulliparous women with epidural analgesia
Authors: Fiedler Anton , Brun Romana , Randegger Debora , Balsyte Dalia , Zimmermann Roland , Haslinger Christian 
Published: May 2020

AbstractObjectiveTo test for an association between blood loss and time until pushing (TUP) after full cervical dilation in nulliparous women with epidural analgesia.MethodsA prospective cohort study was performed at the University Hospital of Zurich between October 2015 and November 2016. Included were 228 nulliparous women with singleton pregnancy, planned vaginal delivery after 36 completed weeks of gestation, epidural analgesia, and guided active pushing. TUP was defined as the interval between full cervical dilation and initiation of active pushing. The primary outcome measure was blood loss, assessed by the postpartum decrease in hemoglobin (ΔHb), estimated blood loss, and rate of ΔHb ≥30 g/L. Associations between TUP and primary and secondary maternal and neonatal delivery outcomes were assessed using Spearman correlation, Mann‐Whitney U test, Kruskal‐Wallis test, or Fisher exact test, as appropriate.ResultsLonger TUP correlated significantly with increased ΔHb (ρ=0.142, P=0.033) and higher rates of ΔHb ≥30 g/l (P=0.002). Composite adverse maternal and neonatal outcomes were unaffected.ConclusionOn the grounds of increased maternal blood loss, and in contrast to the current International Federation of Gynecology and Obstetrics (FIGO) guideline, delayed active pushing is not recommended in nulliparous women with epidural analgesia.